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Find video protocols related to scientific articles indexed in Pubmed.
Differential proteomic analyses of cataracts from rat models of type 1 and 2 diabetes.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 11-20-2014
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PURPOSE. To identify differential changes in proteins and metabolites underlying "fast" type 1 (T1DC) and "slow" type 2 (T2DC) diabetic cataract (DC) formation in rat. METHODS. Rat models of type 1 and 2 diabetes consisted of streptozotocin injection without and with high fat diet, respectively. Cataract progression was examined weekly. At week 6 total protein changes were comparatively and quantitatively assessed by two-dimensional differential in-gel electrophoresis coupled with by mass spectrometry, and relevant metabolic changes were examined. Differences in high molecular weight (HMW) crystallin species between diabetic and control lenses were similarly identified. RESULTS. Cataracts were morphologically different, progressed more slowly in T2DC vs. T1DC. ?A-crystallin, ?B2-crystallin and ?A4-crystallin were significantly decreased in both DC types vs. control. ?B-crystallin was increased while ?B1-crystallin was markedly decreased in T2DC. In T1DC ?B-crystallin and ?S-crystallin fragmentation were increased. High fat diet by itself had little impact, except for lowering ?S-crystallin fragmentation. Despite significantly decreased opacity, a greater decrease in intermediate filaments (IFs) and more HMW crystallin species were observed in T2DC vs. T1DC. However, aldose reductase expression and activity and sorbitol levels were increased to a greater extent in T1DC, while GSH and NADPH levels were decreased to a greater extent, and ATP level was much lower in T1DC vs. T2DC. CONCLUSIONS. The results suggest that osmotic damage, GSH loss and decreased ATP production might be important pathological mechanisms in T1DC formation, whereas crystallin modification and cross-linking/aggregation as well as IF degradation may play more crucial roles in T2DC formation.
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Robust microfiber photonic microcells for sensor and device applications.
Opt Express
PUBLISHED: 11-18-2014
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We report the fabrication of in-line photonic microcells (PMCs) by encapsulating tapered microfibers (MFs) inside glass tubes. The encapsulation isolates MFs from external environment and makes them more suitable for real-world applications. Based on PMCs with encapsulated highly birefringent (Hi-Bi) MFs, we demonstrated pressure, temperature and refractive index (RI) sensors as well as long period grating devices. A fiber Sagnac loop interferometer incorporating a Hi-Bi microfiber PMC demonstrated RI sensitivity of 2024 nm per RI unit (nm/RIU) in gaseous environment and 21231 nm/RIU in water.
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A Photostable Near-Infrared Fluorescent Tracker with pH-Independent Specificity to Lysosomes for Long Time and Multicolor Imaging.
ACS Appl Mater Interfaces
PUBLISHED: 11-11-2014
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A new boron-dipyrromethene-based lysosome tracker, Lyso-NIR, is facilely synthesized. Besides the intensive near-infrared (NIR) fluorescence and high photostability, Lyso-NIR shows the capability to stably localize in lysosomes, which is independent of the local pH. Lyso-NIR does not have the problematic alkalization effect suffered by the commonly used lysotrackers; thus, it shows ignorable cytotoxicity and slightly affects normal physiological functions of lysosomes. The above advantages of Lyso-NIR make it feasible to track lysosomes' dynamic changes in a relatively long time during the full cellular processes such as apoptosis, heavy metal stimulation, and endocytosis, as is demonstrated in this work. Moreover, Lyso-NIR's narrow NIR emission at 740 nm with a full width at half-maximum smaller than 50 nm makes it easy to avoid the crosstalk with the emissions from other common fluorescent probes, which strengthens Lyso-NIR's competitiveness as a standard lysosome tracker for multicolor bioimaging.
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l-Valine derived chiral N-sulfinamides as effective organocatalysts for the asymmetric hydrosilylation of N-alkyl and N-aryl protected ketimines.
Org. Biomol. Chem.
PUBLISHED: 11-08-2014
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l-Valine derived N-sulfinamides have been developed as efficient enantioselective Lewis basic organocatalysts for the asymmetric reduction of N-aryl and N-alkyl ketimines with trichlorosilane. Catalyst afforded up to 99% yield and 96% ee in the reduction of N-alkyl ketimines and up to 98% yield and 98% ee in the reduction of N-aryl ketimines.
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Greater Loss of White Matter Integrity in Postural Instability and Gait Difficulty Subtype of Parkinson's Disease.
Can J Neurol Sci
PUBLISHED: 11-08-2014
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ABSTRACT Background: Patients with the postural instability and gait difficulty (PIGD) subtype of Parkinson disease (PD) are at a higher risk of dysfunction and are less responsive to dopamine replacement therapy. The PIGD subtype was found to largely associate with white matter lesions, but details of the diffusion changes within these lesions have not been fully investigated. Voxel-based analysis for diffusion tensor imaging data is one of the preferred measures to compare diffusion changes in each voxel in any part of the brain. Methods: PD patients with the PIGD (n=12) and non-PIGD subtypes (n=12) were recruited to compare diffusion differences in fractional anisotropy, axial diffusivity, and radial diffusivity with voxel-based analysis. Results: Significantly reduced fractional anisotropy in bilateral superior longitudinal fasciculus, bilateral anterior corona radiata, and the left genu of the corpus callosum were shown in the PIGD subtype compared with the non-PIGD subtype. Increased radial diffusivity in the left superior longitudinal fasciculus was found in the PIGD subtype with no statistical differences in axial diffusivity found. Conclusions: Our study confirms previous findings that white matter abnormalities were greater in the PIGD subtype than in the non-PIGD subtype. Additionally, our findings suggested: (1) compared with the non-PIGD subtype, loss of white matter integrity was greater in the PIGD subtype; (2) bilateral superior longitudinal fasciculus may play a critical role in microstructural white matter abnormalities in the PIGD subtype; and (3) reduced white matter integrity in the PIGD subtype could be mainly attributed to demyelination rather than axonal loss.
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Antioxidant status and Na(+), K (+)-ATPase activity in freshwater fish Carassius auratus exposed to different combustion products of Nafion 117 membrane: an integrated biomarker approach.
Environ Sci Pollut Res Int
PUBLISHED: 11-06-2014
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Nafion 117 membrane (N117), an important polymer electrolyte membrane (PEM), has been widely applied in numerous chemical technologies. Its increasing production and utilization will inevitably lead to the problem of waste disposal, with incineration as an important method. However, toxicity data of its combustion products on aquatic organisms have been seldom reported. The present study was therefore conducted to investigate the antioxidant response and Na(+), K(+)-ATPase activity in liver of Carassius auratus exposed to different combustion products of N117 for 5, 15, and 30 days. The concentrations of fluorine ion (F(-)) in the aquaria among the exposure durations were analyzed using the ion chromatography system. The results showed that these treatments have the capability to induce oxidative stress and suppress Na(+), K(+)-ATPase activity, as indicated by some significant alterations on these measured toxicity end-points in fish liver. According to the integrated biomarker response (IBR) index, the toxicity intensity of these experimental treatments was tentatively ranked. Taken together, these observations provided some preliminary data on the potential toxicity of the combustion products of N117 on aquatic organisms and could fill the information gaps in the toxicity database of the current-use PEM.
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Chiral mononuclear lanthanide complexes and the field-induced single-ion magnet behaviour of a Dy analogue.
Dalton Trans
PUBLISHED: 11-06-2014
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Three pairs of homochiral mononuclear lanthanide complexes, with the general formula [LnH4LRRRRRR/SSSSSS(SCN)2](SCN)2·xCH3OH·yH2O(Ln = Dy (), Ho () and Er ()), have been obtained via self-assembly between chiral macrocyclic ligands and the respective thiocyanates, all of which show a saddle-type conformation with seven-coordinated metal ions. Magnetic measurements revealed that the Dy complex shows field-induced single-ion magnet behaviour, which is rarely reported in a seven-coordinated lanthanide-based SIM encapsulated in a macrocyclic ligand. The absolute configuration of all enantiomers was determined by single crystal X-ray crystallography and confirmed by electronic CD and VCD spectra.
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Synthesis of dendritic iridium nanostructures based on the oriented attachment mechanism and their enhanced CO and ammonia catalytic activities.
Nanoscale
PUBLISHED: 11-04-2014
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Branched iridium nanodendrites (Ir NDs) have been synthesized by a simple method based on the oriented attachment mechanism. Transmission electron microscopy images reveal the temporal growth process from small particles to NDs. Precursor concentrations and reaction temperatures have a limited effect on the morphology of Ir NDs. Metal oxide and hydroxide-supported Ir NDs exhibit enhanced activity for catalytic CO oxidation. Particularly, the Fe(OH)x-supported Ir NDs catalyst with a 4 wt% Ir loading show superior CO oxidation catalytic activity with a full conversion of CO at 120 °C. Furthermore, compared with Ir NPs and commercial Ir black, Ir NDs exhibit higher activity and stability for ammonia oxidation. The specific activity and mass activity of Ir NDs for ammonia oxidation are 1.7 and 7 times higher than that of Ir NPs. The improved catalytic activities of Ir NDs are attributed not only to their large specific surface area, but also to their considerably high index facets and rich edge and corner atoms. Hence, the obtained Ir NDs provide a promising alternative for direct ammonia fuel cells and proton-exchange membrane fuel cells.
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Spectroscopic properties and continuous-wave laser operation of Yb:LuPO4 crystal.
Opt Lett
PUBLISHED: 11-01-2014
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For the first time, and to the best of our knowledge, we report a continuous-wave (cw) laser operation of Yb:LuPO4 crystal, demonstrated at room temperature in a compact plano-concave resonator end pumped by a diode laser. 1.61 W of cw output power around 1039 nm were generated with 2.40 W of pump power at 976 nm absorbed in a 0.3 mm thick crystal, leading to an optical-to-optical efficiency of 67%, whereas the slope efficiency was 75%. Polarized absorption and emission cross-section spectra are also presented and discussed in detail.
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[Community structure of planktonic rotifers in the Pearl River Delta].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 10-28-2014
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Four ecological investigations were carried out on planktonic rotifers in Pearl River Delta in 2012. The community structure, including spatial and temporal patterns of species composition, dominant species, biomass and biodiversity, was investigated. The correlation between the community structure of rotifers and the environmental factors was discussed. Moreover, the aggregation structures of rotifers were analyzed. A total of 53 rotifer species were found. Dominant species changed markedly with season and space. Polyarthra trigla had higher dominance. In terms of seasonal changes, the density and biomass were higher in dry season than in wet season, while the biodiversity and evenness indices were vice versa. The biomass and biodiversity of rotifers showed highly significant differences among seasons. In terms of spatial distribution, the average density and the average biomass showed an increase from the southwest to the northeast. The highest density and biomass were recorded in Shiqiao. The biodiversity and evenness indices had an opposite spatial distribution, with the highest values being recorded in Qingqi. The rotifer density was significantly different among the investigated sites, while the biomass and biodiversity were not significantly different. Correlation analysis demonstrated a highly significant positive correlation between rotifer density and biomass, as well as between biodiversity and evenness indices, and a highly negative correlation between biodiversity and biomass. The biodiversity and evenness indices both decreased markedly with the increase of biomass. Principal component analysis indicated that the rotifer density was closely correlated with environment factors, such as water temperature, pH, dissolved oxy- gen, chlorophyll a content, total phosphorus, and total nitrogen, in different seasons. Aggregation analysis based on rotifer density revealed five aggregation structures in the investigated sites, indicating significant differences in water quality among the investigated sites.
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[Sodium butyrate inhibits HMGB1 expression and release and attenuates concanavalin A-induced acute liver injury in mice].
Sheng Li Xue Bao
PUBLISHED: 10-22-2014
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The purpose of the present study is to explore the protective effects of sodium butyrate (SB) pretreatment on concanavalin A (Con A)-induced acute liver injury in mice. The model animals were first administered intraperitoneally with SB. Half an hour later, acute liver injury mouse model was established by caudal vein injection with Con A (15 mg/kg). Then, levels of serous alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using standard clinical method by an automated chemistry analyzer, tumor necrosis factor-? (TNF-?) and interferon-? (IFN-?) were measured by ELISA, and pathological changes in hepatic tissue were observed by using HE staining and light microscopy. The expression and release of high-mobility group box 1 (HMGB1) were assessed by using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry and ELISA. The results showed that the pretreatment of SB significantly protected Con A-treated mice from liver injury as evidenced by the decrease of serum ALT, AST (P < 0.01) and reduction of hepatic tissues necrosis. SB also decreased levels of serous TNF-? and IFN-? (P < 0.01). Furthermore, the expression and release of HMGB1 were markedly inhibited by SB pretreatment (P < 0.05 or P < 0.01). These results suggest that the attenuating effect of SB on Con A-induced acute liver injury may be due to its role of reducing the TNF-? and IFN-? production, and inhibiting HMGB1 expression and release.
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Single chip super broadband InGaN/GaN LED enabled by nanostructured substrate.
Opt Express
PUBLISHED: 10-17-2014
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A new type of LED, single chip super broadband InGaN/GaN LED is presented in this paper. The LED is composed of an InGaN/GaN quantum well layer deposited on the nanostructured sapphire substrate, inscribed by femtosecond laser ablation. The super broadband emission is enabled due to the large variation of indium composition in a small local area so that different wavelengths can be emitted over a small area and the summation of these different emission wavelengths forms super broadband emission, which covers the entire visible spectral range. The result of this paper represents a major technological advance in white light LED lighting because it enables single chip white LED lighting without the need of phosphor down converter that can significantly improve the efficiency without the Stokes loss and reduce the cost.
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Stored luminescence computed tomography.
Appl Opt
PUBLISHED: 10-17-2014
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Phosphor nanoparticles made of doped semiconductors and pre-excited by x-ray radiation were recently reported for their luminescence emission in the range of 650-770 nm upon near-infrared (NIR) light stimulation. These nanophosphors can be functionalized as optical probes for molecular imaging. In this paper, we present stored luminescence computed tomography to reconstruct a nanophosphor distribution in an object. The propagation of x rays in a biological object allows significantly better localization and deeper penetration. Moreover, the nanophosphors, which are pre-excited with collimated x-ray beams or focused x-ray waves, can be successively stimulated for stored luminescence emissions by variable NIR stimulation patterns. The sequentially detected luminescence signals provide more information of a nanophosphor spatial distribution for more accurate image reconstruction and higher image resolution. A realistic numerical study is performed to demonstrate the feasibility and merits of the proposed approach.
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Oxalyl Amide Assisted Palladium-Catalyzed Arylation of C(sp(2))-H Bond at the ? Position.
Org. Lett.
PUBLISHED: 10-16-2014
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A successful protocol has been developed for ?-arylation of ?-arylethamines at the ortho position under mild conditions. The newly developed methodology first presents broad substrate scope, great functional group tolerance, and good to excellent yield in the synthesis of substituted ?-arylethylamines. The transformation represents a practical advantage of oxalyl amide in assistance with C-H functionalization at a remote position.
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Amplifying the red-emission of upconverting nanoparticles for biocompatible clinically used prodrug-induced photodynamic therapy.
ACS Nano
PUBLISHED: 10-07-2014
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A class of biocompatible upconverting nanoparticles (UCNPs) with largely amplified red-emissions was developed. The optimal UCNP shows a high absolute upconversion quantum yield of 3.2% in red-emission, which is 15-fold stronger than the known optimal ?-phase core/shell UCNPs. When conjugated to aminolevulinic acid, a clinically used photodynamic therapy (PDT) prodrug, significant PDT effect in tumor was demonstrated in a deep-tissue (>1.2 cm) setting in vivo at a biocompatible laser power density. Furthermore, we show that our UCNP-PDT system with NIR irradiation outperforms clinically used red light irradiation in a deep tumor setting in vivo. This study marks a major step forward in photodynamic therapy utilizing UCNPs to effectively access deep-set tumors. It also provides an opportunity for the wide application of upconverting red radiation in photonics and biophotonics.
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An estimate of the error caused by the elongation of the wavelength in a focused beam in free-space electromagnetic parameters measurement.
Rev Sci Instrum
PUBLISHED: 10-03-2014
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A pair of spot-focusing horn lens antenna is the key component in a free-space measurement system. The electromagnetic constitutive parameters of a planar sample are determined using transmitted and reflected electromagnetic beams. These parameters are obtained from the measured scattering parameters by the microwave network analyzer, thickness of the sample, and wavelength of a focused beam on the sample. Free-space techniques introduced by most papers consider the focused wavelength as the free-space wavelength. But in fact, the incident wave projected by a lens into the sample approximates a Gaussian beam, thus, there has an elongation of the wavelength in the focused beam and this elongation should be taken into consideration in dielectric and magnetic measurement. In this paper, elongation of the wavelength has been analyzed and measured. Measurement results show that the focused wavelength in the vicinity of the focus has an elongation of 1%-5% relative to the free-space wavelength. Elongation's influence on the measurement result of the permittivity and permeability has been investigated. Numerical analyses show that the elongation of the focused wavelength can cause the increase of the measured value of the permeability relative to traditionally measured value, but for the permittivity, it is affected by several parameters and may increase or decrease relative to traditionally measured value.
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Enhanced Uptake and Selectivity of CO2 Adsorption in a Hydrostable Metal-Organic Frameworks via Incorporating Methylol and Methyl Groups.
ACS Appl Mater Interfaces
PUBLISHED: 09-22-2014
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A new methylol and methyl functionalized metal-organic frameworks (MOFs) QI-Cu has been designed and synthesized. As a variant of NOTT-101, this material exhibits excellent CO2 uptake capacities at ambient temperature and pressure, as well as high CH4 uptake capacities. The CO2 uptake for QI-Cu is high, up to 4.56 mmol g(-1) at 1 bar and 293 K, which is top-ranked among MOFs for CO2 adsorption and significantly larger than the nonfunctionalized NOTT-101 of 3.93 mmol g(-1). The enhanced isosteric heat values of CO2 and CH4 adsorption were also obtained for this linker functionalized MOFs. From the single-component adsorption isotherms, multicomponent adsorption was predicted using the ideal adsorbed solution theory (IAST). QI-Cu shows an improvement in adsorptive selectivity of CO2 over CH4 and N2 below 1 bar. The incorporation of methylol and methyl groups also greatly improves the hydrostability of the whole framework.
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Structural characterization of the pulmonary innate immune protein SPLUNC1 and identification of lipid ligands.
FASEB J.
PUBLISHED: 09-17-2014
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The short palate, lung and nasal epithelial clone 1 (SPLUNC1) protein is a member of the palate, lung, and nasal epithelium clone (PLUNC) family, also known as bactericidal/permeability-increasing (BPI) fold-containing protein, family A, member 1 (BPIFA1). SPLUNC1 is an abundant protein in human airways, but its function remains poorly understood. The lipid ligands of SPLUNC1 as well as other PLUNC family members are largely unknown, although some reports provide evidence that lipopolysaccharide (LPS) could be a lipid ligand. Unlike previous hypotheses, we found significant structural differences between SPLUNC1 and BPI. Recombinant SPLUNC1 produced in HEK 293 cells harbored several molecular species of sphingomyelin and phosphatidylcholine as its ligands. Significantly, in vitro lipid-binding studies failed to demonstrate interactions between SPLUNC1 and LPS, lipoteichoic acid, or polymyxin B. Instead, one of the major and most important pulmonary surfactant phospholipids, dipalmitoylphosphatidylcholine (DPPC), bound to SPLUNC1 with high affinity and specificity. We found that SPLUNC1 could be the first protein receptor for DPPC. These discoveries provide insight into the specific determinants governing the interaction between SPLUNC1 and lipids and also shed light on novel functions that SPLUNC1 and other PLUNC family members perform in host defense.-Ning, F., Wang, C., Berry, K. Z., Kandasamy, P., Liu, H., Murphy, R. C., Voelker, D. R., Nho, C. W., Pan, C.-H., Dai, S., Niu, L., Chu, H-W., Zhang, G. Structural characterization of the pulmonary innate immune protein SPLUNC1 and identification of lipid ligands.
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Graphene Activating Room-Temperature Ferromagnetic Exchange in Cobalt-Doped ZnO Dilute Magnetic Semiconductor Quantum Dots.
ACS Nano
PUBLISHED: 09-17-2014
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Control over the magnetic interactions in dilute magnetic semiconductor quantum dots (DMSQDs) is a key issue to future development of nanometer-sized integrated "spintronic" devices. However, manipulating the magnetic coupling between impurity ions in DMSQDs remains a great challenge because of the intrinsic quantum confinement effects and self-purification of the quantum dots. Here, we propose a hybrid structure to achieve room-temperature ferromagnetic interactions in DMSQDs, via engineering the density and nature of the energy states at the Fermi level. This idea has been applied to Co-doped ZnO DMSQDs where the growth of a reduced graphene oxide shell around the Zn0.98Co0.02O core turns the magnetic interactions from paramagnetic to ferromagnetic at room temperature, due to the hybridization of 2pz orbitals of graphene and 3d obitals of Co(2+)-oxygen-vacancy complexes. This design may open up a kind of possibility for manipulating the magnetism of doped oxide nanostructures.
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[Chemical constituents from Pleione yunnanensis].
Zhongguo Zhong Yao Za Zhi
PUBLISHED: 09-11-2014
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This study was to investigate the chemical constituents from pseudobulbs of Pleione yunnanensis, one of the source of traditional Chinese medicine "Shancigu". The chemical constituents were isolated by various chromatography methods, including silica gel, ODS, Sephadex LH-20, and semi-preparative HPLC. Fourteen compounds were isolated and identified from the EtOAc fraction of 90% ethanol extract, including five dihydrophenanthrenes, four bibenzyls, two triterpenoids, and three phenylacrylic acids. Their structures were identified on the basis of the spectral data as 4, 7-dihydroxy-2-methoxy-9,10-dihydrophenanthrene (1), 4, 7-dihydroxy-1-(p-hydroxybenzyl)-2-methoxy-9,10-dihydrophenanthrene (2), (2,3-trans)-2-(4-hydroxy-3-methoxyphenyl) -3-hydroxymethyl-10-methoxy-2,3,4,5-tetrahydro-phenanthro[2,1-b]furan-7-ol (3), pleionesin B (4), blestriarene A (5), batatasin III (6), 3, 3'-dihydroxy-2-(p-hydroxybenzyl) -5-methoxybibenzyl (7), 3', 5-dihydroxy-2-(p-hydroxybenzyl) -3-methoxybibenzyl (8), 3,3'-dihydroxy-2,6-bis(4-hydroxybenzyl) -5-methoxybibenzyl (9), triphyllol (10), pholidotin (11), (E) -p-hydroxycinnamic acid (12), (E)-ferulic acid (13), and (E)-ferulic acid hexacosyl ester (14). Compounds 5,10-14 were separated from this plant for the first time.
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[Construction of transgenic tobacco expressing popW and analysis of its biological phenotype].
Sheng Wu Gong Cheng Xue Bao
PUBLISHED: 09-09-2014
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In a previous study, we cloned popW from Ralstonia solanacearum strain ZJ3721, coding PopW, a new harpin protein. The procaryotically expressed PopW can induce resistance to Tobacco mosaic virus (TMV), enhance growth and improve quality of tobacco, when sprayed onto tobacco leaves. Here, we constructed an expression vector pB- popW by cloning popW into the bionary vector pBI121 and transformed it into Agrobacterium tumefaciens strain EHA105 via freeze-thaw method. Tobacco (Nicotiana tobacum cv. Xanthi nc.) transformation was conducted by infection of tobacco leaf discs with recombinant A. tumefaciens. After screening on MS medium containing kanamycin, PCR and RT-PCR analysis, 21 T3 lines were identified as positive transgenic. Genomic intergration and expression of the transferred gene were determined by PCR and RT-PCR. And GUS staining analysis indicated that the protein expressed in transgenic tobacco was bioactive and exhibited different expression levels among lines. Disease bioassays showed that the transgenic tobacco had enhanced resistance to TMV with biocontrol efficiency up to 54.25%. Transgenic tobacco also exhibited enhanced plant growth, the root length of 15 d old seedlings was 1.7 times longer than that of wild type tobacco. 60 d after transplanting to pots, the height, fresh weight and dry weight of transgenic tobacco were 1.4, 1.7, 1.8 times larger than that of wild type tobacco, respectively.
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Lysophosphatidylcholine and amide as metabolites for detecting alzheimer disease using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabonomics.
J. Neuropathol. Exp. Neurol.
PUBLISHED: 09-06-2014
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Alzheimer disease (AD) can be diagnosed by clinical and neuropsychologic tests and at autopsy, but there are no simple effective diagnostic methods for detecting biomarkers in patients at early stages of cognitive impairment. Early metabolic alterations that may facilitate AD diagnosis have not been thoroughly explored. We applied a nontargeted metabonomic approach using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to analyze serum and urine samples from 46 patients with AD and 36 healthy controls. Metabolite profiles were processed using multivariate analysis to identify potential metabolites, which were further confirmed using tandem mass spectrometry. Ultrahigh-performance liquid chromatography mass spectrometry methods were additionally used to quantify potentially important biomarkers. Independent samples were then selected to validate the identified biomarkers. There was a clear separation between healthy controls and AD patients; AD patient samples had disordered amino acid and phospholipid metabolism and dysregulated palmitic amide. Receiver operator characteristic curve and quantification suggested that palmitic amide, lysophosphatidylcholine (LysoPC, 18:0), LysoPC(18:2), L-glutamine, and 5-L-glutamylglycine were the optimal metabolites. In addition, areas under the curve from the palmitic amide, LysoPC(18:2), and 5-L-glutamylglycine in the validation study were 0.714, 0.996, and 0.734, respectively. These data elucidate the metabolic alterations associated with AD and suggest new biomarkers for AD diagnosis, thereby permitting early intervention designed to prevent disease progression.
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Aridity threshold in controlling ecosystem nitrogen cycling in arid and semi-arid grasslands.
Nat Commun
PUBLISHED: 09-04-2014
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Higher aridity and more extreme rainfall events in drylands are predicted due to climate change. Yet, it is unclear how changing precipitation regimes may affect nitrogen (N) cycling, especially in areas with extremely high aridity. Here we investigate soil N isotopic values (?(15)N) along a 3,200?km aridity gradient and reveal a hump-shaped relationship between soil ?(15)N and aridity index (AI) with a threshold at AI=0.32. Variations of foliar ?(15)N, the abundance of nitrification and denitrification genes, and metabolic quotient along the gradient provide further evidence for the existence of this threshold. Data support the hypothesis that the increase of gaseous N loss is higher than the increase of net plant N accumulation with increasing AI below AI=0.32, while the opposite is favoured above this threshold. Our results highlight the importance of N-cycling microbes in extremely dry areas and suggest different controlling factors of N-cycling on either side of the threshold.
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Arsenic trioxide and microRNA-204 display contrary effects on regulating adipogenic and osteogenic differentiation of mesenchymal stem cells in aplastic anemia.
Acta Biochim. Biophys. Sin. (Shanghai)
PUBLISHED: 09-03-2014
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Our previous studies have demonstrated that arsenic trioxide (ATO) had the clinical efficacy in treating patients with aplastic anemia (AA). However, the mechanisms remain to be elucidated. The important components of the bone marrow hematopoietic microenvironment, bone marrow mesenchymal stem cells (BMSCs), are often altered in AA patients. In this study, it was found that AA BMSCs were prone to be induced into adipocytes rather than osteoblasts. ATO treatment can at least partially restore the differentiation imbalance of AA BMSCs. We further identified miR-204 as a key regulator in AA BMSC differentiation. Luciferase reporter assay showed that miR-204 could directly bind to the 3'-untranslated region of Runx2 mRNA, a key transcription factor regulating osteogenesis. Moreover, adipogenic differentiation was promoted and osteogenic differentiation was inhibited in miR-204 over-expressed cells, whereas osteogenesis was enhanced and adipocyte formation was inhibited in cells that lost miR-204 function, which suggested its endogenous function. Together we showed that ATO could inhibit adipogenic differentiation, but promote osteogenic differentiation in AA BMSCs, providing a possible explanation for ATO clinical efficacy in AA patients. MiR-204 plays a key role in regulating BMSCs differentiation, and down-regulating miR-204 expression might be a novel strategy to treat AA.
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[Chemical constituents against hepatic fibrosis from Phyllodium pulchellum roots].
Zhong Yao Cai
PUBLISHED: 09-02-2014
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To investigate the bioactive constituents against hepatic fibrosis from the roots of Phyllodium pulchellum.
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Perilipin 5 improves hepatic lipotoxicity by inhibiting lipolysis.
Hepatology
PUBLISHED: 09-01-2014
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Abnormal metabolism of non-esterified fatty acids (NEFAs) and their derivatives has been reported to be the main cause of intracellular lipotoxic injury. Normally, NEFAs are stored in lipid droplets (LDs) in the form of triglyceride (TG), which could reduce the lipotoxicity of cytosolic NEFAs. Previous studies have implicated that Perilipin 5 (Plin5), a LD-binding protein, regulates the storage and hydrolysis of TG in LD. However, its roles and underlying mechanisms in the liver remain unknown. Here, we found that Plin5 expression was increased in steatotic livers. Using Plin5 knockout mice, we found that Plin5 deficiency resulted in reduced hepatic lipid content and smaller-sized LDs, which was due to the elevated lipolysis rate and fatty acid utilization. Plin5-deficient hepatocytes showed increased mitochondria proliferation, which could be explained by the increased expression and activity of PPAR? stimulated by the increased NEFA levels. Meanwhile, Plin5-deficient livers also exhibited enhanced mitochondrial oxidative capacity. We also found that Plin5 deficiency induces lipotoxic injury in hepatocytes, attributed to lipid peroxidation. Mechanistically, we found that Plin5 blocks adipose triglyceride lipase (ATGL)-mediated lipolysis by competitively binding to comparative gene identification-58 (CGI-58) and disrupting the interaction between CGI-58 and ATGL. Conclusion: We revealed Plin5 as an important protective factor against hepatic lipotoxicity induced by NEFAs generated from lipolysis, which provides an important new insight into the regulation of hepatic lipid storage and relation between lipid storage and lipotoxicity. (Hepatology 2014;).
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New insight into the hydrocarbon-pool chemistry of the methanol-to-olefins conversion over zeolite H-ZSM-5 from GC-MS, solid-state NMR spectroscopy, and DFT calculations.
Chemistry
PUBLISHED: 09-01-2014
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Over zeolite H-ZSM-5, the aromatics-based hydrocarbon-pool mechanism of methanol-to-olefins (MTO) reaction was studied by GC-MS, solid-state NMR spectroscopy, and theoretical calculations. Isotopic-labeling experimental results demonstrated that polymethylbenzenes (MBs) are intimately correlated with the formation of olefin products in the initial stage. More importantly, three types of cyclopentenyl cations (1,3-dimethylcyclopentenyl, 1,2,3-trimethylcyclopentenyl, and 1,3,4-trimethylcyclopentenyl cations) and a pentamethylbenzenium ion were for the first time identified by solid-state NMR spectroscopy and DFT calculations under both co-feeding ([(13) C6 ]benzene and methanol) conditions and typical MTO working (feeding [(13) C]methanol alone) conditions. The comparable reactivity of the MBs (from xylene to tetramethylbenzene) and the carbocations (trimethylcyclopentenyl and pentamethylbenzium ions) in the MTO reaction was revealed by (13) C-labeling experiments, evidencing that they work together through a paring mechanism to produce propene. The paring route in a full aromatics-based catalytic cycle was also supported by theoretical DFT calculations.
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Gamabufotalin, a bufadienolide compound from toad venom, suppresses COX-2 expression through targeting IKK?/NF-?B signaling pathway in lung cancer cells.
Mol. Cancer
PUBLISHED: 08-31-2014
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Gamabufotalin (CS-6), a major bufadienolide of Chansu, has been used for cancer therapy due to its desirable metabolic stability and less adverse effect. However, the underlying mechanism of CS-6 involved in anti-tumor activity remains poorly understood.
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miR-124 controls Drosophila behavior and is required for neural development.
Int. J. Dev. Neurosci.
PUBLISHED: 08-26-2014
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MicroRNA-124 (miR-124) is an evolutionarily conserved, small, noncoding RNA molecule that participates in the central nervous system (CNS) developmental control of gene expression. In the current study, we found that Drosophila embryos lacking the mir-124 gene did not exhibit detectable defects in axon growth or CNS development. On the other hand, adult mutants showed severe problems in locomotion, flight, and female fertility. Furthermore, the deficits that we observed in the adult stage could be marginally rescued with elav-GAL4 driven expression of miR-124, making elav-GAL4 an excellently simulated driver to induce entopic over-expression of miR-124. Further developmental assessment in the third instar larval neuromuscular junction (NMJ) and dendritic arborization (DA) neurons was performed with miR-124 knock outs, flies over-expressing miR-124, and rescue models. Typically, the absence and over-abundance of a molecular signal exerts opposite effects on development or phenotype. However, we determined that both miR-124 knock-outs and over-expressing flies displayed reduced NMJ 6/7 bouton number and branch length. Similarly, reduced ddaE branching numbers were observed between the two mutant lines. As to ddaF, we found that branching number was not influenced by mir-124 knock out, but was statistically reduced by miR-124 over-expression. While we were not able to determine any causal relationship between behavioral defects and dysplasia of NMJs or DA neurons, there were some accompanying relationships among behavioral phenotypes, NMJ abnormalities, and ddaE/ddaF dendritic branching which were all controlled by miR-124.
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Conjugation of a nonspecific antiviral sapogenin with a specific HIV fusion inhibitor: a promising strategy for discovering new antiviral therapeutics.
J. Med. Chem.
PUBLISHED: 08-26-2014
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Triterpene saponins are a major group of active components in natural products with nonspecific antiviral activities, while T20 peptide (enfuvirtide), which contains a helix zone-binding domain (HBD), is a gp41-specific HIV-1 fusion inhibitor. In this paper, we report the design, synthesis, and structure-activity relationship (SAR) of a group of hybrid molecules in which bioactive triterpene sapogenins were covalently attached to the HBD-containing peptides via click chemistry. We found that either the triterpenes or peptide part alone showed weak activity against HIV-1 Env-mediated cell-cell fusion, while the hybrids generated a strong cooperative effect. Among them, P26-BApc exhibited anti-HIV-1 activity against both T20-sensitive and -resistant HIV-1 strains and improved pharmacokinetic properties. These results suggest that this scaffold design is a promising strategy for developing new HIV-1 fusion inhibitors and possibly novel antiviral therapeutics against other viruses with class I fusion proteins.
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Structural and mutational studies on an aldo-keto reductase AKR5C3 from Gluconobacter oxydans.
Protein Sci.
PUBLISHED: 08-23-2014
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An aldo-keto reductase AKR5C3 from Gluconobacter oxydans (designated as Gox0644) is a useful enzyme with various substrates, including aldehydes, diacetyl, keto esters, and ?-ketocarbonyl compounds. The crystal structures of AKR5C3 in apoform in complex with NADPH and the D53A mutant (AKR5C3(-D53A) ) in complex with NADPH are presented herein. Structure comparison and site-directed mutagenesis combined with biochemical kinetics analysis reveal that the conserved Asp53 in the AKR5C3 catalytic tetrad has a crucial role in securing active pocket conformation. The gain-of-function Asp53 to Ala mutation triggers conformational changes on the Trp30 and Trp191 side chains, improving NADPH affinity to AKR5C3, which helps increase catalytic efficiency. The highly conserved Trp30 and Trp191 residues interact with the nicotinamide moiety of NADPH and help form the NADPH-binding pocket. The AKR5C3(-W30A) and AKR5C3(-W191Y) mutants show decreased activities, confirming that both residues facilitate catalysis. Residue Trp191 is in the loop structure, and the AKR5C3(-W191Y) mutant does not react with benzaldehyde, which might also determine substrate recognition. Arg192, which is involved in the substrate binding, is another important residue. The introduction of R192G increases substrate-binding affinity by improving hydrophobicity in the substrate-binding pocket. These results not only supplement the AKRs superfamily with crystal structures but also provide useful information for understanding the catalytic properties of AKR5C3 and guiding further engineering of this enzyme.
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Intermittent hypoxia preconditioning-induced epileptic tolerance by upregulation of monocarboxylate transporter 4 expression in rat hippocampal astrocytes.
Neurochem. Res.
PUBLISHED: 08-22-2014
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Noxious stimuli applied at doses close to but below the threshold of cell injury induce adaptive responses that provide a defense against additional stress. Epileptic preconditioning protects neurons against status epilepticus and ischemia; however, it is not known if the converse is true. During hypoxia/ischemia (H/I), lactate released from astrocytes is taken up by neurons and is stored for energy, a process mediated by monocarboxylate transporter 4 (MCT4) in astroglia. The present study investigated whether H/I preconditioning can provide protection to neurons against epilepsy through upregulation of MCT4 expression in astrocytes in vitro and in vivo. An oxygen/glucose deprivation protocol was used in primary astrocyte cultures, while rats were subjected to an intermittent hypoxia preconditioning (IHP) paradigm followed by lithium-pilocarpine-induced epilepsy as well as lactate transportation inhibitor injection, with a subsequent evaluation of protein expression as well as behavior. H/I induced an upregulation of MCT4 expression, while an IHP time course of 5 days provided the greatest protection against epileptic seizures, which was most apparent by 3 days after IHP. However, lactate transport function disturbances can block the protective effect induced by IHP. These findings provide a potential basis for the clinical treatment of epilepsy.
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The Protective Effects of Rhodiola crenulata Extracts on Drosophila melanogaster Gut Immunity Induced by Bacteria and SDS Toxicity.
Phytother Res
PUBLISHED: 08-22-2014
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The aim of this study was to observe the effect of the Rhodiola crenulata extracts on gut immunity of Drosophila melanogaster. Wild-type flies fed standard cornmeal-yeast medium were used as controls. Experimental groups were supplemented with 2.5% R.?crenulata aqueous extracts in standard medium. Survival rate was determined by feeding pathogenic microorganisms and toxic compounds. The levels of reactive oxygen species and dead cells were detected by dihydroethidium and 7-amino-actinomycin D staining, respectively. The expression of antimicrobial peptides was evaluated by quantitative polymerase chain reaction, and morphological change of the intestine was imaged by an Axioskop 2 plus microscope. The results demonstrate that R.?crenulata increased the survival rates of adult flies and expression of antimicrobial peptide genes after pathogen or toxic compound ingestion. Moreover, decreased levels of reactive oxygen species and epithelial cell death were associated with results in improved intestinal morphology. The pharmacological action of R.?crenulata from Tibet was greater than that from Sichuan. These results indicate that the R.?crenulata extracts from Tibet had better pharmacological effect on D.?melanogaster gut immunity after ingestion of pathogens and toxic compounds. These results may provide the pharmacological basis for prevention of inflammatory diseases of the intestine. Copyright © 2014 John Wiley & Sons, Ltd.
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Systematic evaluation of percutaneous radiofrequency ablation versus percutaneous ethanol injection for the treatment of small hepatocellular carcinoma: a meta-analysis.
Eur. J. Med. Res.
PUBLISHED: 08-20-2014
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Radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) have been used for patients with hepatocellular carcinoma (HCC). However, which therapy is superior remains to be further elucidated. We aimed to conduct a systematic review to assess survival and local tumor recurrence rate with RFA compared with PEI therapy for HCC.
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A prospective randomized trial of selective versus nonselective esophagogastric devascularization for portal hypertension.
J. Huazhong Univ. Sci. Technol. Med. Sci.
PUBLISHED: 08-19-2014
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Cirrhosis with portal hypertension is a common disease which has a significant impact on the quality of patients' life. Esophagogastric devascularization (EGDV) has been demonstrated to be an effective method to treat portal hypertension, however certain complications are associated with it. The purpose of this study was to evaluate the effectiveness and clinical outcome of the selective EGDV (sEGDV) for the treatment of portal hypertension. The study was conducted prospectively from Jan. 1 2011 to Dec. 31, 2012, and 180 patients were randomized to the sEGDV group (n=90) or the non-sEGDV (n-sEGDV) group (n=90). Patients' demographics, preoperative lab test results and operative details were comparable between the two groups. Postoperative and short-term complications were analyzed in two groups. There was statistically significant difference (P<0.01) in the PVF reduction between the two groups. Post-operative complications showed no statistically significant difference between the two groups in the incidence of bleeding, ascites, acute portal vein thrombosis, fever and hepatic encephalopathy. Mortality between two groups was comparable. The incidence of splenic fossa effusion after the surgery was lower in sEGDV group than in n-sEGDV group. There were no significant differences in the short-term follow-up data such as esophageal varices and portal hypertensive gastropathy (P>0.05). It is suggested that sEGDV is a safe, simple and effective surgical procedure. It has both the advantages of the shunt and devascularization because it preserves body's voluntary diversion. With the advantage of low incidence of postoperative complications, it is an ideal surgical approach for the treatment of portal hypertension.
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[Effects of bacterial consortium EG03 on control of pepper bacterial wilt and rhizosphere microbial community characteristics in fields].
Ying Yong Sheng Tai Xue Bao
PUBLISHED: 08-19-2014
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Bacterial consortium EG03, consisted of several different antagonistic bacteria against Ralstonia solanacearum, was demonstrated to efficiently control bacterial wilt of pepper in field with a biocontrol efficacy of 85.8%. The traditional dilution plate method, the most probable number (MPN) method and Biolog system were adopted to determine effects of EG03 on characteristics of microbial community in pepper rhizosphere. It's shown that EGO3's effects on microbial community in pepper rhizospheric soil varied with time. There were an increase in the number of fungus and Bacillus spp. to some extent and a significant increase in that of nitrogen-fixing bacteria. Biolog analysis showed that the curve between average well color development (AWCD) and incubation time was S-shaped for all the treatments and that the AWCD of pepper rhizospheric soil at the early stage was higher than at the late stage. The analysis of carbon source utilization showed that EG03 decreased microbial utilization of carbon source in short-term, and the microbial community of pepper rhizospheric soil at the late stage composed mainly of microbes depended on sugars as carbon resource. EG03 treatment could decrease the five microbial diversity indices of rhizospheric microbes in short term, then increased those indices instead, especially with significant (P < 0.05) increases in Simpson index and McIntosh evenness.
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Combined photothermal and photodynamic therapy delivered by PEGylated MoS2 nanosheets.
Nanoscale
PUBLISHED: 08-16-2014
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Single- or few-layered transitional metal dichalcogenides, as a new genus of two-dimensional nanomaterials, have attracted tremendous attention in recent years, owing to their various intriguing properties. In this study, chemically exfoliated MoS2 nanosheets are modified with lipoic acid-terminated polyethylene glycol (LA-PEG), obtaining PEGylated MoS2 (MoS2-PEG) with high stability in physiological solutions and no obvious toxicity. Taking advantage of its ultra-high surface area, the obtained MoS2-PEG is able to load a photodynamic agent, chlorin e6 (Ce6), by physical adsorption. In vitro experiments reveal that Ce6 after being loaded on MoS2-PEG shows remarkably increased cellular uptake and thus significantly enhanced photodynamic therapeutic efficiency. Utilizing the strong, near-infrared (NIR) absorbance of the MoS2 nanosheets, we further demonstrate photothermally enhanced photodynamic therapy using Ce6-loaded MoS2-PEG for synergistic cancer killing, in both in vitro cellular and in vivo animal experiments. Our study presents a new type of multifunctional nanocarrier for the delivery of photodynamic therapy, which, if combined with photothermal therapy, appears to be an effective therapeutic approach for cancer treatment.
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Alkylation of benzene with carbon monoxide over Zn/H-ZSM-5 zeolite studied using in situ solid-state NMR spectroscopy.
Chem. Commun. (Camb.)
PUBLISHED: 08-16-2014
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Using in situ solid-state NMR spectroscopy we show that CO can act as an alkylating reagent and react with benzene to produce toluene over a Zn/H-ZSM-5 zeolite. In the alkylation reaction, CO provides the methyl group of toluene via a methoxy intermediate.
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An Intelligent Robotic Hospital Bed for Safe Transportation of Critical Neurosurgery Patients Along Crowded Hospital Corridors.
IEEE Trans Neural Syst Rehabil Eng
PUBLISHED: 08-15-2014
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We present a novel design of an intelligent robotic hospital bed, named Flexbed, with autonomous navigation ability. The robotic bed is developed for fast and safe transportation of critical neurosurgery patients without changing beds. Flexbed is more efficient and safe during transportation process comparing to the conventional hospital beds. Flexbed is able to avoid enroute obstacles with an efficient easy-to-implement collision avoidance strategy when an obstacle is nearby, and move towards its destination at maximum speed when there is no threat of collision. We present extensive simulation results of navigation of Flexbed in the crowded hospital corridor environments with moving obstacles. Moreover, results of experiments with Flexbed in the real world scenarios are also presented and discussed.
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Fiber-optic ferrule-top nanomechanical resonator with multilayer graphene film.
Opt Lett
PUBLISHED: 08-15-2014
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Compact ferrule-top nanomechanical resonators with multilayer graphene (MLG) diaphragms as vibrating elements are demonstrated. The resonators comprise a suspended MLG film supported by a ceramic ferrule with a bore diameter of ?125 ?m. The mechanical resonance of the graphene film is excited and detected by an all-fiber optical interrogation system. Based on a beam-shape graphene mechanical resonator, a force sensitivity of ?3.8 fN/Hz1/2 was theoretically predicted. The integration of nanomechanical graphene film with optical fiber simplifies the excitation and interrogation of the resonator and would allow the development of practical fiber-optic sensors for force, mass, and pressure measurements.
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Structural basis of diverse membrane target recognitions by ankyrins.
Elife
PUBLISHED: 08-13-2014
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Ankyrin adaptors together with their spectrin partners coordinate diverse ion channels and cell adhesion molecules within plasma membrane domains and thereby promote physiological activities including fast signaling in the heart and nervous system. Ankyrins specifically bind to numerous membrane targets through their 24 ankyrin repeats (ANK repeats), although the mechanism for the facile and independent evolution of these interactions has not been resolved. Here we report the structures of ANK repeats in complex with an inhibitory segment from the C-terminal regulatory domain and with a sodium channel Nav1.2 peptide, respectively, showing that the extended, extremely conserved inner groove spanning the entire ANK repeat solenoid contains multiple target binding sites capable of accommodating target proteins with very diverse sequences via combinatorial usage of these sites. These structures establish a framework for understanding the evolution of ankyrins' membrane targets, with implications for other proteins containing extended ANK repeat domains.
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Clinical outcomes of multidrug resistant pseudomonas aeruginosa infection and the relationship with type III secretion system in patients with diabetic foot.
Int J Low Extrem Wounds
PUBLISHED: 08-08-2014
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The objective was to analyze the clinical outcomes of multidrug resistant Pseudomonas aeruginosa (MDRPA) infection and determine the relationship between type III secretion system (TTSS) and MDRPA in diabetic foot (DF) patients. A total of 117 patients infected with P aeruginosa were recruited and grouped into MDRPA and non-MDRPA group according to antimicrobial susceptibility testing. TTSS genes were detected by polymerase chain reaction (PCR). Potential risk factors for MDRPA infection were examined using univariate and multivariate analyses. Clinical outcomes were compared on the basis of MDRPA or TTSS virulence gene. Previous antibiotic therapy, previous hospitalization and osteomyelitis were associated with MDRPA infection. MDRPA group had a higher amputation/toe rate (32.6% vs 16.2%) and lower healing rate (20.9% vs 41.9%) than non-MDRPA group (P = .032). A significantly higher proportion of exoU was present in MDRPA group (75.0% vs 25.0%, P < .05) than non-MDRPA group. Patients infected with exoU isolates had a lower healing rate and higher amputation/toe rate (25.0% vs 65.2%, 33.3% vs 8.7%, P < .05) than infected with exoS isolates. The exoU gene was predominance among MDRPA strains. The poor clinical outcomes of MDRPA infection in patients with DF were attributable to exoU gene.
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Dynamic information flow analysis in Vascular Dementia patients during the performance of a visual oddball task.
Neurosci. Lett.
PUBLISHED: 08-07-2014
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This study investigated the information flow in patients with Vascular Dementia (VaD). Twelve VaD patients and twelve age-matched controls participated in the study. EEG signal was recorded when subjects were performing a visual oddball task. Information flow was analyzed between 9 electrodes in frontal, central, and parietal lobes using short-window Directed Transfer Function (sDTF). VaD patients presented a significant decline in the information flow from parietal to frontal and central lobes, compared with the healthy elderly. This decline mainly occurred in delta, theta, and lower alpha bands, from about 200ms to 300ms after target stimulus onset. The findings indicated an impaired parietal-to-frontal and parietal-to-central connectivity in VaD patients, which may be one reason for the cognitive deficits in VaD patients.
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cRGD-directed, NIR-responsive and robust AuNR/PEG-PCL hybrid nanoparticles for targeted chemotherapy of glioblastoma in vivo.
J Control Release
PUBLISHED: 08-07-2014
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cRGD-directed, NIR-responsive and robust AuNR/PEG-PCL hybrid nanoparticles (cRGD-HNs) were designed and developed for targeted chemotherapy of human glioma xenografts in mice. As expected, cRGD-HNs had excellent colloidal stability. The in vitro release studies showed that drug release from DOX-loaded cRGD-HNs (cRGD-HN-DOX) was minimal under physiological conditions but markedly accelerated upon NIR irradiation at a low power density of 0.2W/cm(2), due to photothermally induced phase transition of PCL regime. MTT assays showed that the antitumor activity of cRGD-HN-DOX in ?v?3 integrin over-expressed human glioblastoma U87MG cells was greatly boosted by mild NIR irradiation, which was significantly more potent than non-targeting HN-DOX counterpart under otherwise the same conditions and was comparable or superior to free DOX, supporting receptor-mediated endocytosis mechanism. The in vivo pharmacokinetics studies showed that cRGD-HN-DOX had much longer circulation time than free DOX. The in vivo imaging and biodistribution studies revealed that cRGD-HN-DOX could actively target human U87MG glioma xenograft in nude mice. The therapeutic studies in human U87MG glioma xenografts exhibited that cRGD-HN-DOX in combination with NIR irradiation completely inhibited tumor growth and possessed much lower side effects than free DOX. The Kaplan-Meier survival curves showed that all mice treated with cRGD-HN-DOX plus NIR irradiation survived over an experimental period of 48days while control groups treated with PBS, cRGD-HN-DOX, cRGD-HNs with NIR irradiation, free DOX, or HN-DOX with NIR irradiation (non-targeting control) had short life spans of 15-40days. Ligand-directed AuNR/PEG-PCL hybrid nanoparticles with evident tumor-targetability as well as superior spatiotemporal and rate control over drug release have emerged as an appealing platform for cancer chemotherapy in vivo.
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SmartMal: a service-oriented behavioral malware detection framework for mobile devices.
ScientificWorldJournal
PUBLISHED: 08-05-2014
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This paper presents SmartMal--a novel service-oriented behavioral malware detection framework for vehicular and mobile devices. The highlight of SmartMal is to introduce service-oriented architecture (SOA) concepts and behavior analysis into the malware detection paradigms. The proposed framework relies on client-server architecture, the client continuously extracts various features and transfers them to the server, and the server's main task is to detect anomalies using state-of-art detection algorithms. Multiple distributed servers simultaneously analyze the feature vector using various detectors and information fusion is used to concatenate the results of detectors. We also propose a cycle-based statistical approach for mobile device anomaly detection. We accomplish this by analyzing the users' regular usage patterns. Empirical results suggest that the proposed framework and novel anomaly detection algorithm are highly effective in detecting malware on Android devices.
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Limitation of spatial distribution of ammonia-oxidizing microorganisms in the Haihe River, China, by heavy metals.
J Environ Sci (China)
PUBLISHED: 08-01-2014
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The Haihe River is characterized by high ammonia pollution. Therefore, it is necessary to determine how environmental factors, such as heavy metals in the river limit the spatial distribution of ammonia-oxidizing microorganisms. In this study, the relationships between five heavy metals and ammonia-oxidizing microorganisms were studied. The results showed that under high ammonia, low oxygen and high concentrations of suspended particles, ammonia-oxidizing bacteria (AOB) ranged from 10(1.3) to 10(4.8) gene copies/mL and ammonia-oxidizing archaea (AOA) ranged from 10(2.7) to 10(4.9) gene copies/mL. The average metal concentrations in water were 23.57 (Cr), 21.58 (Ni), 65.09 (Cu), 622.03 (Zn) and 10.16 (As) ?g/L, with those of Zn, Cu and Cr being higher than the US EPA criteria. Scatter plots of microbial abundance and metals indicated that both AOA and AOB were limited by heavy metals, but in different ways. As had an inhibitory effect on AOB, while Ni and Zn promoted AOA, and the other metals investigated showed no significant correlation with microbial abundance. Overall, our results indicated that the effects of heavy metals on ammonia-oxidizing microorganisms in water are complex, and that the final effect is determined by the physiological role of each element in the microorganisms, as well as environmental conditions such as complexation of organic matter, not simply the total metal concentration.
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Enhanced rotation sensing by nonlinear interactions in silicon microresonators.
Opt Lett
PUBLISHED: 08-01-2014
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We analyze the effect of the nonlinear Kerr index of refraction and two-photon absorption (TPA) in a rotating silicon microring resonator coupled to waveguides in an add-drop configuration. The nonlinear index of refraction leads to a bifurcation of the intensities of two counterpropagating modes in the nonrotating state. This bifurcation also significantly enhances the intensity difference between these modes due to the Sagnac-induced frequency splitting of the modes in the rotating resonator. Although silicon resonators have a very large Kerr index, they also suffer from large TPA at telecom wavelengths. It is shown that despite TPA, the Kerr nonlinear enhancement to the rotation sensitivity is still of the order of 104. An analysis of typical detector noise indicates that a detection limit of <1??deg/h in a 1.4 mm radius resonator is achievable.
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Genome-wide analysis reveals artificial selection on coat colour and reproductive traits in Chinese domestic pigs.
Mol Ecol Resour
PUBLISHED: 07-30-2014
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Pigs from Asia and Europe were independently domesticated from c. 9000 years ago. During this period, strong artificial selection has led to dramatic phenotypic changes in domestic pigs. However, the genetic basis underlying these morphological and behavioural adaptations is relatively unknown, particularly for indigenous Chinese pigs. Here, we performed a genome-wide analysis to screen 196 regions with selective sweep signals in Tongcheng pigs, which are a typical indigenous Chinese breed. Genes located in these regions have been found to be involved in lipid metabolism, melanocyte differentiation, neural development and other biological processes, which coincide with the evolutionary phenotypic changes in this breed. A synonymous substitution, c.669T>C, in ESR1, which colocalizes with a major quantitative trait locus for litter size, shows extreme differences in allele frequency between Tongcheng pigs and wild boars. Notably, the variant C allele in this locus exhibits high allele frequency in most Chinese populations, suggesting a consequence of positive selection. Five genes (PRM1, PRM2, TNP2, GPR149 and JMJD1C) related to reproductive traits were found to have high haplotype similarity in Chinese breeds. Two selected genes, MITF and EDNRB, are implied to shape the two-end black colour trait in Tongcheng pig. Subsequent SNP microarray studies of five Chinese white-spotted breeds displayed a concordant signature at both loci, suggesting that these two genes are responsible for colour variations in Chinese breeds. Utilizing massively parallel sequencing, we characterized the candidate sites that adapt to artificial and environmental selections during the Chinese pig domestication. This study provides fundamental proof for further research on the evolutionary adaptation of Chinese pigs.
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Controllable preparation of Ni nanoparticles for catalysis of coiled carbon fibers growth.
Nanoscale Res Lett
PUBLISHED: 07-29-2014
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The mass preparation of high-purity coiled carbon fibers (CCFs) remains challenging due to the high complexity and low controllability of reaction. In this work, a controllable growth of Ni particles was fulfilled by liquid phase reduction of nickel sulfate with hydrazine hydrate. The impacts of the reaction temperature, NaOH concentration, and reaction time on the particle size and purity were investigated. The as-deposited Ni particles were characterized by scanning electron microscopy and X-ray diffraction. In addition, these Ni particles were also applied in preparing high-purity CCFs both on graphite and ceramic substrates. The diameter of the as-grown carbon microcoil was about 500 nm, and the related growth mechanism was discussed.
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Microbial ketonization of ginsenosides F1 and C-K by Lactobacillus brevis.
Antonie Van Leeuwenhoek
PUBLISHED: 07-17-2014
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Ginsenosides are the major pharmacological components in ginseng. We isolated lactic acid bacteria from Kimchi to identify microbial modifications of ginsenosides. Phylogenetic analysis of 16S rRNA gene sequences indicated that the strain DCY65-1 belongs to the genus Lactobacillus and is most closely related to Lactobacillus brevis. On the basis of TLC and HPLC analysis, we found two metabolic pathways: F1 ? 6?,12?-dihydroxydammar-3-one-20(S)-O-?-D-glucopyranoside and C-K ? 12?-hydroxydammar-3-one-20(S)-O-?-D-glucopyranoside. These results suggest that strain DCY65-1 is capable of potent ketonic decarboxylation, ketonizing the hydroxyl group at C-3. The F1 metabolite had a more potent inhibitory effect on mushroom tyrosinase than did the substrate. Therefore, the F1 and C-K derivatives may be more pharmacologically active compounds, which should be further characterized.
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Altered Directed Connectivity in Patients with Early Vascular Dementia During a Visual Oddball Task.
Brain Topogr
PUBLISHED: 07-16-2014
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The altered functional connectivity in the brain of patients with early vascular dementia (VaD) is poorly understood. Here we investigated the directed connectivity differences between VaD and normal elderly while performing a visual oddball task. Multichannel EEG data during a visual oddball task were recorded for 12 patients with early VaD and 12 age, gender and education matched healthy elderly. Directed transfer function was used to investigate the directed connectivity of brain during pre-stimulus and post-stimulus periods in delta, theta, alpha and beta frequency bands. Significantly reduced inter-hemispheric connectivity was found in patients with early VaD compared to normal elderly in the delta and theta frequency bands during the pre-stimulus period. During the post-stimulus period, besides the decreased inter-hemispheric connectivity, significantly decreased parietal-to-frontal/central connectivity was also found in VaD compared to normal elderly in the delta frequency band. In addition to the decreased connectivity in VaD, significantly increased connectivity was also found both in the pre-stimulus and post-stimulus periods. These results suggest that pathophysiology changes in early VaD may cause the altered directed connectivity of the brain network. Our observations demonstrate the altered brain connectivity of early VaD and reveal impairment and compensation co-exist in patients with early VaD.
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Expression profiles of 12 late embryogenesis abundant protein genes from Tamarix hispida in response to abiotic stress.
ScientificWorldJournal
PUBLISHED: 07-10-2014
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Twelve embryogenesis abundant protein (LEA) genes (named ThLEA-1 to -12) were cloned from Tamarix hispida. The expression profiles of these genes in response to NaCl, PEG, and abscisic acid (ABA) in roots, stems, and leaves of T. hispida were assessed using real-time reverse transcriptase-polymerase chain reaction (RT-PCR). These ThLEAs all showed tissue-specific expression patterns in roots, stems, and leaves under normal growth conditions. However, they shared a high similar expression patterns in the roots, stems, and leaves when exposed to NaCl and PEG stress. Furthermore, ThLEA-1, -2, -3, -4, and -11 were induced by NaCl and PEG, but ThLEA-5, -6, -8, -10, and -12 were downregulated by salt and drought stresses. Under ABA treatment, some ThLEA genes, such as ThLEA-1, -2, and -3, were only slightly differentially expressed in roots, stems, and leaves, indicating that they may be involved in the ABA-independent signaling pathway. These findings provide a basis for the elucidation of the function of LEA genes in future work.
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Immunological Responses Triggered by Photothermal Therapy with Carbon Nanotubes in Combination with Anti-CTLA-4 Therapy to Inhibit Cancer Metastasis.
Adv. Mater. Weinheim
PUBLISHED: 07-07-2014
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In this work, it is uncovered that photothermal ablation of primary tumors with single-walled carbon nanotubes is able to trigger significant adaptive immune responses, which are not observed if -tumors are removed by surgical resection. Such a treatment in combination with anti-CTLA-4 antibody therapy is able to prevent the development of tumor metastasis, which is a major cause of cancer death.
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Identification of functional cis-elements required for repression of the Taka-amylase A gene under secretion stress in Aspergillus oryzae.
Biotechnol. Lett.
PUBLISHED: 07-07-2014
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The expression of secreted proteins in filamentous fungi is down-regulated by a transcriptional feedback mechanism under endoplasmic reticulum stress, termed repression under secretion stress (RESS). To investigate the RESS mechanism, we analyzed the expression of the Taka-amylase A gene (amyB) in Aspergillus oryzae, which was depressed under secreted protein stress. We conducted a truncation and deletion analysis of the amyB promoter to identify cis-elements required for RESS. A nucleotide sequence (positions -378 to -291) without any binding sites for the transcriptional activator AmyR, which is involved in amylolytic gene expression, was required for RESS. The octamer sequence TCACGGGC (positions -307 to -300) constituted the core sequence of the upstream activating element essential for amyB down-regulation under secretion stress. Both the inactivation of AmyR and RESS contributed to the down-regulation of amyB expression under ER stress.
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Associations between apolipoprotein CIII concentrations and microalbuminuria in type 2 diabetes.
Exp Ther Med
PUBLISHED: 07-07-2014
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Microalbuminuria (MAU) is a strong predictor of diabetic nephropathy (DN), which is the main cause of morbidity and mortality in patients with diabetes mellitus (DM). Dyslipidemia exists in the majority of patients with DM and contributes to micro- and macrovascular complications associated with DM. Apolipoprotein CIII (apoCIII) is an inhibitor of the activity of lipoprotein lipase, which metabolizes triglyceride (TG) in very low-density lipoprotein (VLDL) and facilitates its clearance from plasma. The aim of the present study was to investigate the associations between apoCIII and MAU and the effects of atorvastatin in type 2 diabetes. In total, 120 subjects were divided into type 2 diabetes and type 2 DN groups, while 60 healthy subjects were selected as controls. The patients with DN were administered 20 mg atorvastatin daily for 16 weeks. Blood pressure, body mass index (BMI) and levels of HbA1c, FBG, TG, VLDL-cholesterol (VLDL-C), apoCIII and MAU were markedly elevated in the type 2 diabetes and type 2 DN groups compared with those in the control group (P<0.01), while high-density lipoprotein-cholesterol (HDL-C) levels were decreased significantly (P<0.01). All patients with type 2 DN showed significantly elevated blood pressure, apoCIII levels, MAU, course of the disease and rate of stroke and retinopathy compared with the patients with type 2 diabetes (P<0.01). MAU was significantly positively correlated with the course of the disease, systolic blood pressure, diastolic blood pressure, BMI and HbA1c, FBG, TG, total cholesterol, low-density lipoprotein-cholesterol, VLDL-C and apoCIII levels (P<0.05), whereas negatively correlated with HDL-C levels (r=-0.194, P=0.020). Logistic regression analysis showed that apoCIII levels were independently associated with MAU (odds ratio, 1.100; 95% confidence interval, 1.037-1.153; P<0.001). Atorvastatin improved the lipid profile and MAU in patients with type 2 DN (P<0.01). Therefore, the present study demonstrated that an independent positive correlation exists between the levels of apoCIII and MAU in patients with type 2 diabetes. Furthermore, atorvastatin may be used to improve the lipid profile and MAU in type 2 DN.
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Expression differences of anthocyanin biosynthesis genes reveal regulation patterns for red pear coloration.
Plant Cell Rep.
PUBLISHED: 07-01-2014
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This research reveals the different expression patterns of anthocyanin biosynthesis enzyme genes and transcription factors in six red-skinned pear cultivars with different genetic backgrounds. Skin color is an important feature of pear fruits, with red skin generally attracting consumers. However, great differences of coloration exist in different pear cultivars. To elucidate the characteristics of pigmentation in pear cultivars with different genetic backgrounds, six cultivars, belonging to P. communis, P. pyrifolia, P. ussuriensis, P. bretschneideri, and a hybrid of P. communis × P. pyrifolia, were used to detect pigment concentrations, expressions of seven anthocyanin biosynthesis enzyme genes, and three related transcription factor genes. Results showed that the occidental pears 'Starkrimson' and 'Red Bartlett' colored at the beginning of fruit setting, but color decreased with fruit maturity; the other four cultivars showed low anthocyanin accumulations and the contents increased during fruit development, but also decreased at later stages. The expression patterns of genes encoding enzymes indicated that ANS and UFGT were decisive genes for anthocyanin biosynthesis for red-skinned pear, and their different expressions led to the coloration differences between occidental and oriental pears. The expression patterns of transcription factors indicated that the different co-expression of MYB10 and bHLH33 genes and the different expressions of WD40 are involved in the differential regulation mechanisms of anthocyanin biosynthesis and coloration pattern between occidental and oriental pears.
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Galectin-9-CD44 interaction enhances stability and function of adaptive regulatory T cells.
Immunity
PUBLISHED: 06-26-2014
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The ?-galactoside-binding protein galectin-9 is critical in regulating the immune response, but the mechanism by which it functions remains unclear. We have demonstrated that galectin-9 is highly expressed by induced regulatory T cells (iTreg) and was crucial for the generation and function of iTreg cells, but not natural regulatory T (nTreg) cells. Galectin-9 expression within iTreg cells was driven by the transcription factor Smad3, forming a feed-forward loop, which further promoted Foxp3 expression. Galectin-9 increased iTreg cell stability and function by directly binding to its receptor CD44, which formed a complex with transforming growth factor-? (TGF-?) receptor I (TGF-?RI), and activated Smad3. Galectin-9 signaling was further found to regulate iTreg cell induction by dominantly acting through the CNS1 region of the Foxp3 locus. Our data suggest that exogenous galectin-9, in addition to being an effector molecule for Treg cells, acts synergistically with TGF-? to enforce iTreg cell differentiation and maintenance.
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Phenotype and expression profile analysis of Staphylococcus aureus biofilms and planktonic cells in response to licochalcone A.
Appl. Microbiol. Biotechnol.
PUBLISHED: 06-23-2014
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Staphylococcus aureus is one of the most important pathogens in humans and animals. The formation of biofilm by S. aureus is considered an important mechanism of antimicrobial resistance. Therefore, finding effective drugs against the biofilm produced by S. aureus has been a high priority. Licochalcone A (LAA), a natural plant product, was reported to have antibacterial activities and showed good activity against all 21 tested strains of S. aureus biofilm and planktonic cells. To detect the possible molecular mechanism of LAA against S. aureus biofilm or planktonic cells, Affymetrix GeneChips were used to determine the global comparative transcription of S. aureus biofilm and planktonic cells triggered by treatment with sub-bactericidal and sub-inhibitory concentrations of LAA, respectively. LAA significantly altered (greater than a 2- or less than -2-fold change) the expression of 693 genes in planktonic cells and 817 genes in biofilm. The levels of genes encoding autolysis-associated proteins, cell wall proteins, pathogenic factors, protein synthesis genes, and enzymes involved in capsule synthesis were significantly altered in LAA-treated S. aureus. Furthermore, some differences observed in the microarray analysis were verified by real-time RT-PCR. To our knowledge, this is the first observation of phenotype and expression profiles of S. aureus biofilm and planktonic cells in response to LAA treatment.
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Antimicrobial activity of the imipenem/rifampicin combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures.
World J. Microbiol. Biotechnol.
PUBLISHED: 06-18-2014
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To investigate the antimicrobial activity of imipenem and rifampicin alone and in combination against clinical isolates of Acinetobacter baumannii grown in planktonic and biofilm cultures. Minimum inhibitory concentrations were determined for each isolate grown in suspension and in biofilm using a microbroth dilution method. Chequerboard assays and the agar disk diffusion assay were used to determine synergistic, indifferent or antagonistic interactions between imipenem and rifampicin. We used the tissue culture plate method for A. baumannii biofilm formation to measure the percentage of biofilm inhibition and the amount of extracellular DNA after the treatment. To understand the synergistic mechanisms, we conducted hydroxyl radical formation assays. The results were verified by confocal laser scanning microscopy. Imipenem and rifampicin showed effective antimicrobial activity against suspensions and biofilm cultures of A. baumannii, respectively. Synergistic antimicrobial effects between imipenem and rifampicin were observed in 13 and 17 of the 20 clinical isolates when in suspension and in biofilms, respectively. Imipenem and rifampicin alone and in combination generated hydroxyl radicals, which are highly reactive oxygen forms and the major components of bactericidal agents. Furthermore, treatment with imipenem and rifampicin individually or in combination has obvious antibiofilm effects. The synergistic activity of imipenem and rifampicin against clinical isolates of A. baumannii (in suspension and in biofilms) was observed in vitro. Therefore, we conclude that imipenem combined with rifampicin has the potential to be used as a combinatorial therapy for the treatment of infectious diseases caused by A. baumannii.
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Epidermal growth factor-network signaling mediates luteinizing hormone regulation of BNP and CNP and their receptor NPR2 during porcine oocyte meiotic resumption.
Mol. Reprod. Dev.
PUBLISHED: 06-17-2014
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The epidermal growth factor (EGF) network, induced by luteinizing hormone (LH), plays an essential role during the regulation of oocyte maturation, cumulus expansion, and ovulation. Binding of brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) to natriuretic receptor 2 (NPR2) generates cyclic guanosine monophosphate (cGMP), a key inhibitor that sustains porcine oocyte meiotic arrest. This correlation suggests that LH interacts with natriuretic-peptide signaling, possibly via the EGF network, to promote porcine meiotic resumption. In testing this hypothesis, we found that the majority of porcine oocytes remain arrested in the germinal-vesicle stage after 44?hr of co-culturing cumulus-oocyte complexes with 10(7) granulosa cells, which secreted active BNP and CNP; these natriuretic peptides associate with NPR2 on cumulus cells, thereby inhibiting porcine oocyte maturation. This inhibitory effect of BNP and CNP was relieved by EGF-like growth factors, whose expression naturally increases in granulosa cells 18?hr after human chorionic gonadotropin injection. LH and the EGF-like peptide amphiregulin (AREG) decreased BNP and CNP production in granulosa cells and down-regulated NPR2 expression in cumulus cells, which together decreased oocyte cGMP to levels that permit meiotic resumption. The effects of AREG on the gene expression of natriuretic-peptide signaling components and on oocyte maturation were completely blocked by the EGF receptor kinase inhibitor AG1478; the effect of LH, however, was only partially reversed by AG1478. Based on these results, LH regulates natriuretic-peptide signaling, although other pathways also cooperate with the EGF network to induce porcine oocyte maturation. Mol. Reprod. Dev. 81: 1030-1041, 2014. © 2014 Wiley Periodicals, Inc.
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Regioselective Glucuronidation of Andrographolide and Its Major Derivatives: Metabolite Identification, Isozyme Contribution, and Species Differences.
AAPS J
PUBLISHED: 06-17-2014
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Andrographolide (AND) and two of its derivatives, deoxyandrographolide (DEO) and dehydroandrographolide (DEH), are widely used in clinical practice as anti-inflammatory agents. However, UDP-glucuronosyltransferase (UGT)-mediated phase II metabolism of these compounds is not fully understood. In this study, glucuronidation of AND, DEO, and DEH was characterized using liver microsomes and recombinant UGT enzymes. We isolated six glucuronides and identified them using 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. We also systematically analyzed various kinetic parameters (K m, V max, and CLint) for glucuronidation of AND, DEO, and DEH. Among 12 commercially available UGT enzymes, UGT1A3, 1A4, 2B4, and 2B7 exhibited metabolic activities toward AND, DEO, and DEH. Further, UGT2B7 made the greatest contribution to glucuronidation of all three anti-inflammatory agents. Regioselective glucuronidation showed considerable species differences. 19-O-Glucuronides were present in liver microsomes from all species except rats. 3-O-Glucuronides were produced by pig and cynomolgus monkey liver microsomes for all compounds, and 3-O-glucuronide of DEH was detected in mouse and rat liver microsomes (RLM). Variations in K m values were 48.6-fold (1.93-93.6 ?M) and 49.5-fold (2.01-99.1 ?M) for 19-O-glucuronide and 3-O-glucuronide formation, respectively. Total intrinsic clearances (CLint) for 3-O- and 19-O-glucuronidation varied 4.8-fold (22.7-110 ?L min(-1) mg(-1)), 10.6-fold (94.2-991 ?L min(-1) mg(-1)), and 8.3-fold (122-1,010 ?L min(-1) mg(-1)), for AND, DEH, and DEO, respectively. Our results indicate that UGT2B7 is the major UGT enzyme involved in the metabolism of AND, DEO, and DEH. Metabolic pathways in the glucuronidation of AND, DEO, and DEH showed considerable species differences.
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The structural basis of urea-induced protein unfolding in ?-catenin.
Acta Crystallogr. D Biol. Crystallogr.
PUBLISHED: 06-16-2014
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Although urea and guanidine hydrochloride are commonly used to denature proteins, the molecular underpinnings of this process have remained unclear for a century. To address this question, crystal structures of ?-catenin were determined at various urea concentrations. These structures contained at least 105 unique positions that were occupied by urea molecules, each of which interacted with the protein primarily via hydrogen bonds. Hydrogen-bond competition experiments showed that the denaturing effects of urea were neutralized when polyethylene glycol was added to the solution. These data suggest that urea primarily causes proteins to unfold by competing and disrupting hydrogen bonds in proteins. Moreover, circular-dichroism spectra and nuclear magnetic resonance (NMR) analysis revealed that a similar mechanism caused protein denaturation in the absence of urea at pH levels greater than 12. Taken together, the results led to the conclusion that the disruption of hydrogen bonds is a general mechanism of unfolding induced by urea, high pH and potentially other denaturing agents such as guanidine hydrochloride. Traditionally, the disruption of hydrophobic interactions instead of hydrogen bonds has been thought to be the most important cause of protein denaturation.
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Enantioselective Self-Assembly of Triangular Dy3 Clusters with Single-Molecule Magnet Behavior.
Chem Asian J
PUBLISHED: 06-16-2014
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Three pairs of enantiopure chiral triangular Ln3 clusters, [Ln3 LRRRRRR/SSSSSS (?3 -OH)2 (H2 O)2 (SCN)4 ]?xCH3 OH?yH2 O (R-Dy3 , Ln=Dy, x=6, y=0; S-Dy3 , Ln=Dy, x=6, y=1; R-Ho3 , Ln=Ho, x=6, y=1; S-Ho3 , Ln=Ho, x=6, y=1; R-Er3 , Ln=Er, x=6, y=0; S-Er3 , Ln=Er, x=6, y=1), have been successfully synthesized by a rational enantioselective synthetic strategy. The core of triangular Ln3 is bound in the central N6 O3 of the macrocyclic ligand, and the coordination spheres of Ln ions are completed by four SCN(-) anions and two H2 O molecules in axial positions of the macrocycle. The circular dichroism (CD) and vibrational circular dichroism (VCD) spectra of the enantiomers demonstrate that the chirality is successfully transferred from the ligands to the resulting Ln3 clusters. Ac susceptibility measurements reveal that single-molecule magnet behavior occurs for both enantiopure clusters of R-Dy3 and S-Dy3 . This work is one of the few examples of the successful design of a pair of triangular Dy3 clusters showing simultaneously slow magnetic relaxation and optical activity, and this might open up new opportunities to develop novel multifunctional materials.
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Pseudoxanthoma elasticum: A review of 86 cases in China.
Intractable Rare Dis Res
PUBLISHED: 06-05-2014
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Pseudoxanthoma elasticum (PXE) is a type of rare hereditary disease that affects connective tissue. PXE is found around the world, and its epidemiology in China is still unclear. A database search revealed that 86 patients in total were reported in China from 1985 to 2013. The vast majority of these reports concern single, sporadic cases. This review summarizes the clinical characteristics of PXE and its treatment in China. The hope is to provide a reliable basis for studies on the incidence of PXE and for formulation of relevant policies in the future.
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Antidiabetic Effect of Methanolic Extract from Berberis julianae Schneid. via Activation of AMP-Activated Protein Kinase in Type 2 Diabetic Mice.
Evid Based Complement Alternat Med
PUBLISHED: 05-27-2014
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We have investigated the antidiabetic effect and mechanism of methanolic extract of Berberis julianae Schneid. (BJSME) in STZ induced Type 2 diabetes mellitus mice. T2DM mice were induced by high fat diet and low dose streptozotocin (STZ). BJSME was orally administrated at the doses of 60, 120, and 240?mg/kg/d, for 21 days. Metformin was used as positive control drug. Food intake, body weight, plasma glucose, oral glucose tolerance test, insulin tolerance test, insulin, and blood-lipid content were measured. The effects of BJSME on the glucose transporter 4 (GLUT4) translocation in L6 myotubes and the GLUT4 protein expression in skeletal muscle as well as phosphorylation of the AMP-activated protein kinase (AMPK) in liver and muscle were examined. In vitro and in vivo results indicate that BJSME increased GLUT4 translocation by 1.8-fold and BJSME significantly improved the oral glucose tolerance and low density lipoprotein cholesterol (LDL-C) of serum and reduced body weight, glucose, and other related blood-lipid contents. The BJSME treatment also stimulated the phosphorylation of AMPK. Thus, BJSME seems to possess promising beneficial effects for the treatment of T2DM with the possible mechanism via stimulating AMPK activity.
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Preparation and characterization of pH-sensitive and antifouling poly(vinylidene fluoride) microfiltration membranes blended with poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid).
J Colloid Interface Sci
PUBLISHED: 05-14-2014
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Functional terpolymer of poly(methyl methacrylate-2-hydroxyethyl methacrylate-acrylic acid) (P(MMA-HEMA-AA)) was synthesized via a radical polymerization method. The terpolymer could be directly blended with poly(vinylidene fluoride) (PVDF) to prepare the microfiltration (MF) membranes via phase separate process. The synthesized polymers were characterized by Fourier transform infrared (FTIR), the nuclear magnetic resonance proton spectra ((1)H NMR). The membrane had the typical asymmetric structure and the hydrophilic side chains tended to aggregate on the membrane surface. The surface enrichment of amphiphilic copolymer and morphology of MF membranes were characterized by Fourier transform infrared attenuated total reflection spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). The contact angle (CA) and water uptake were also tested to assess the hydrophilicity and wetting characteristics of the polymer surface. The water filtration properties were measured. It was found the modified membranes showed excellent pH-sensitivity and pH-reversibility behavior. Furthermore, the hydrophilicity of the blended membranes increased, and the membranes showed good protein antifouling property.
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The prevention and treatment effects of tanshinone IIA on oestrogen/androgen-induced benign prostatic hyperplasia in rats.
J. Steroid Biochem. Mol. Biol.
PUBLISHED: 04-29-2014
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Benign prostatic hyperplasia (BPH) is one of the major diseases of the urinary system in elderly men. Tanshinone IIA (Tan IIA) is the active ingredient extracted from the traditional Chinese medicine Salvia, and it has effects of anti-oxidation, anti-inflammation, vascular smooth muscle relaxation and tumour growth inhibition. The present study aimed to investigate the therapeutic potential of Tan IIA in the prevention and treatment of BPH. In a rat model of oestradiol/testosterone-induced BPH, Tan IIA inhibited the increase in the thickness of the peri-glandular smooth muscle layer, suppressed the expression of proliferating cell nuclear antigen (PCNA) in both prostate epithelial cells and stromal cells, downregulated the expression of androgen receptor (AR), oestrogen receptor ? (ER?), cyclin B1 (CCNB1) and cyclin D1 (CCND1), and effectively prevented the development of the disorder. In vitro, Tan IIA inhibited the proliferation of human prostate stromal cell line WPMY-1 and epithelial cell line RWPE-1 in a dose- and time-dependent manner. In WPMY-1 cells, Tan IIA treatment arrested the cell cycle at the G2/M phase and downregulated the expression of CCNB1. However, in RWPE-1 cells, Tan IIA treatment arrested cell cycle at the G0/G1 phase and reduced the expression of CCND1. Tan IIA also reduced the expression of ER? and AR in WPMY-1 and RWPE-1 cells. These results suggest that Tan IIA can inhibit the growth of prostate stromal and epithelial cells both in vivo and in vitro by a mechanism that may involve arresting the cell cycle and downregulating ER? and AR expression.
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Efficient synthesis of functionalized spiro[indoline-3,4[Formula: see text]-pyrrolo[3,4-b]pyridines] via one-pot three-component reaction.
Mol. Divers.
PUBLISHED: 04-23-2014
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Diverse functionalized spiro[indoline-3,4[Formula: see text]-pyrrolo[3,4-b]pyridines] were efficiently synthesized by the three-component reaction of 3-arylamino-1-methyl-[Formula: see text]-pyrrole-2,5-dione, isatins and malononitrile (ethyl cyanoacetate) in ethanol in the presence of triethylamine. This reaction not only provided a convenient synthetic method for the construction of a versatile spirooxindole system, but also access to reactive [Formula: see text]-enaminone and its derivatives for organic and medical chemistry.
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Comparative proteomics reveal the impact of OmcA/MtrC deletion on Shewanella oneidensis MR-1 in response to hexavalent chromium exposure.
Appl. Microbiol. Biotechnol.
PUBLISHED: 04-17-2014
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Hexavalent chromium [Cr(VI)] is a priority pollutant causing serious environmental issues. Microbial reduction provides an alternative strategy for Cr(VI) remediation. The dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1, was employed to study Cr(VI) reduction and toxicity in this work. To understand the effect of membrane cytochromes on Cr(VI) response, a comparative protein profile analysis from S. oneidensis MR-1 wild type and its mutant of deleting OmcA and MtrC (?omcA/mtrC) was conducted using two-dimensional electrophoresis (2-DE) technology. The 2-DE patterns were compared, and the proteins with abundant changes of up to twofold in the Cr(VI) treatment were detected. Using mass spectrometry, 38 and 45 differentially abundant proteins were identified in the wild type and the mutant, respectively. Among them, 25 proteins were shared by the two strains. The biological functions of these identified proteins were analyzed. Results showed that Cr(VI) exposure decreased the abundance of proteins involved in transcription, translation, pyruvate metabolism, energy production, and function of cellular membrane in both strains. There were also significant differences in protein expressions between the two strains under Cr(VI) treatment. Our results suggest that OmcA/MtrC deletion might result in the Cr(VI) toxicity to outer membrane and decrease assimilation of lactate, vitamin B12, and cystine. When carbohydrate metabolism was inhibited by Cr(VI), leucine and sulfur metabolism may act as the important compensatory mechanisms in the mutant. Furthermore, the mutant may regulate electron transfer in the inner membrane and periplasm to compensate for the deletion of OmcA and MtrC in Cr(VI) reduction.
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