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Find video protocols related to scientific articles indexed in Pubmed.
Influence of surface cracks on laser-induced damage resistance of brittle KH2PO4 crystal.
Opt Express
PUBLISHED: 11-18-2014
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Single point diamond turning (SPDT) currently is the leading finishing method for achieving ultra-smooth surface on brittle KH2PO4 crystal. In this work, the light intensification modulated by surface cracks introduced by SPDT cutting is numerically simulated using finite-difference time-domain algorithm. The results indicate that the light intensification caused by surface cracks is wavelength, crack geometry and position dependent. Under the irradiation of 355nm laser, lateral cracks on front surfaces and conical cracks on both front and rear surfaces can produce light intensification as high as hundreds of times, which is sufficient to trigger avalanche ionization and finally lower the laser damage resistance of crystal components. Furthermore, we experimentally tested the laser-induced damage thresholds (LIDTs) on both crack-free and flawed crystal surfaces. The results imply that brittle fracture with a series of surface cracks is the dominant source of laser damage initiation in crystal components. Due to the negative effect of surface cracks, the LIDT on KDP crystal surface could be sharply reduced from 7.85J/cm2 to 2.33J/cm2 (355nm, 6.4ns). In addition, the experiment of laser-induced damage growth is performed and the damage growth behavior agrees well with the simulation results of light intensification caused by surface cracks with increasing crack depths.
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Lewis Base-Promoted Rearrangement of Allylic Cyanohydrins: Construction of Functionalized Nitriles Bearing 1,3-Diketone Moieties.
J. Org. Chem.
PUBLISHED: 11-04-2014
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A novel Lewis base-promoted rearrangement of allylic cyanohydrins has been developed, in which the cyano group was rearranged, directly coupled with the generation of new functional groups. This protocol provides a unique and facile way to prepare highly functionalized nitriles bearing 1,3-diketone moieties under mild reaction conditions. Furthermore, the synthetic transformations of the functionalized products have also been demonstrated.
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EGR2 is critical for peripheral naïve T-cell differentiation and the T-cell response to influenza.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 11-03-2014
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Early growth response 2 (EGR2) transcription factor negatively regulates T-cell activation, in contrast to the positive regulation of this process by EGR1. Here, we unexpectedly found that EGR2 promotes peripheral naïve T-cell differentiation, with delayed T-cell receptor-induced proliferation in naïve T cells from Egr2 conditional knockout (CKO) mice and decreased production of IFN-?, IL-4, IL-9, and IL-17A in cells subjected to T-helper differentiation. Moreover, genes that promote T-cell activation, including Tbx21 and Notch1, had decreased expression in Egr2 CKO T cells and are direct EGR2 target genes. Following influenza infection, Egr2 CKO mice had delayed viral clearance, more weight loss, and more severe pathological changes in the lung than did WT and Egr1 KO mice, with decreased production of effector cytokines, increased infiltration of antigen-specific memory-precursor CD8(+) T cells, and lower numbers of lung-resident memory CD8(+) T cells. Thus, unexpectedly, EGR2 can function as a positive regulator that is essential for naïve T-cell differentiation and in vivo T-cell responses to a viral infection.
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Characterization of Ambient Particles Size in Workplace of Manufacturing Physical Fitness Equipments.
Ind Health
PUBLISHED: 10-21-2014
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The manufacturing of fitness equipment involves several processes, including the cutting and punching of iron tubes followed by welding. Welding operations produce hazardous gases and particulate matter, which can enter the alveolar, resulting in adverse health effects. This study sought to verify the particle size distribution and exposure concentrations of atmospheric air samples in various work areas of a fitness equipment manufacturing industry. Observed particle concentrations are presented by area and in terms of relative magnitude: painting (15.58?mg/m(3))> automatic welding (0.66?mg/m(3))> manual welding (0.53?mg/m(3)) > punching (0.18?mg/m(3))> cutting (0.16?mg/m(3)). The concentrations in each of the five work areas were Cinh > Cthor > Cresp. In all areas except the painting area, extra-fine particles produced by welding at high temperatures, and further those coagulated to form larger particles. This study observed bimodal distribution in the size of welding fume in the ranges of 0.7-1 µm and 15-21 µm. Meanwhile, the mass concentrations of particles with different sizes were not consistent across work areas. In the painting area, the mass concentration was higher in Chead> Cth>Calv, but in welding areas, it was found that Calv> Chead>Cth. Particles smaller than 1 µm were primarily produced by welding.
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Genetics pathway-based imaging approaches in Chinese Han population with Alzheimer's disease risk.
Brain Struct Funct
PUBLISHED: 10-15-2014
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The tau hypothesis has been raised with regard to the pathophysiology of Alzheimer's disease (AD). Mild cognitive impairment (MCI) is associated with a high risk for developing AD. However, no study has directly examined the brain topological alterations based on combined effects of tau protein pathway genes in MCI population. Forty-three patients with MCI and 30 healthy controls underwent resting-state functional magnetic resonance imaging (fMRI) in Chinese Han, and a tau protein pathway-based imaging approaches (7 candidate genes: 17 SNPs) were used to investigate changes in the topological organisation of brain activation associated with MCI. Impaired regional activation is related to tau protein pathway genes (5/7 candidate genes) in patients with MCI and likely in topologically convergent and divergent functional alterations patterns associated with genes, and combined effects of tau protein pathway genes disrupt the topological architecture of cortico-cerebellar loops. The associations between the loops and behaviours further suggest that tau protein pathway genes do play a significant role in non-episodic memory impairment. Tau pathway-based imaging approaches might strengthen the credibility in imaging genetic associations and generate pathway frameworks that might provide powerful new insights into the neural mechanisms that underlie MCI.
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Increased risk of tuberculosis in patients with type 1 diabetes mellitus: results from a population-based cohort study in taiwan.
Medicine (Baltimore)
PUBLISHED: 10-14-2014
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The studies on the risk of tuberculosis (TB) in patients with type 1 diabetes mellitus (T1DM) alone are limited. We examined this relationship using a population-based retrospective cohort study. From claims data of the National Health Insurance system of Taiwan, we identified 5195 patients with T1DM newly diagnosed from 2002 to 2011 and 20,780 randomly selected controls without T1DM, frequency matched by age, sex, and year of diagnosis. Both cohorts were followed up until the end of 2011 to evaluate the risk of TB. The overall incidence of TB was 4.07-fold higher in the T1DM cohort than in the control cohort (1.18 vs 0.29 per 1000 person-years, P?
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Adult asthma increases dementia risk: a nationwide cohort study.
J Epidemiol Community Health
PUBLISHED: 10-02-2014
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Studies on the association between adult asthma and dementia are few. We investigated the risk of dementia in patients diagnosed with adult asthma compared with that of people without asthma who were age and sex matched to the study patients.
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DFT Study of the Mechanism and Stereochemistry of the Rh(I)-Catalyzed Diels-Alder Reactions between Electronically Neutral Dienes and Dienophiles.
J. Org. Chem.
PUBLISHED: 09-26-2014
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Diels-Alder reaction between electronically neutral dienes and dienophiles is usually sluggish under thermal conditions and has to be catalyzed by transition metal catalysts. We report here our DFT study of the mechanism and stereochemistry of the Rh-catalyzed Diels-Alder reaction between electronically neutral dienes and dienophiles (alkenes and alkynes), finding that this reaction includes a reaction sequence of oxidative cyclization between diene and alkene/alkyne and a reductive elimination step. The alkyne's oxidative cyclization is much faster than alkene's due to the additional coordination of alkyne to the Rh center in the oxidative cyclization transition state. For both intermolecular and intramolecular reactions, the reductive elimination step in the catalytic cycle is rate-determining. The different reactivity of ene-diene and yne-diene substrates can be rationalized by the model that reductive elimination to form a C(sp(2))-C(sp(3)) bond is easier than that for the formation of a C(sp(3))-C(sp(3)) bond, due to the additional coordination of the double bond to the Rh center in the transition state in the former. We also uncovered the reasons for the high para-selectivity of the intermolecular Diels-Alder reaction of dienes and alkynes. In addition, DFT calculations aiming to understand the high diastereoselectivity of an intramolecular [4 + 2] reaction of ene-dienes with substituents adjacent to the diene and ene moieties of the substrates found that the substituents in the substrates favor staying away from the Rh center in the oxidative cyclization transition states. This preference leads to the generation of the final [4 + 2] products with the substituents and the bridgehead hydrogen atoms in a cis-configuration.
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Effect of octa(aminophenyl) polyhedral oligomeric silsesquioxane functionalized graphene oxide on the mechanical and dielectric properties of polyimide composites.
ACS Appl Mater Interfaces
PUBLISHED: 09-02-2014
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An effective method is proposed to prepare octa(aminophenyl) silsesquioxane (OAPS) functionalized graphene oxide (GO) reinforced polyimide (PI) composites with a low dielectric constant and ultrastrong mechanical properties. The amine-functionalized surface of OAPS-GO is a versatile starting platform for in situ polymerization, which promotes the uniform dispersion of OAPS-GO in the PI matrix. Compared with GO/PI composites, the strong interfacial interaction between OAPS-GO and the PI matrix through covalent bonds facilitates a load transfer from the PI matrix to the OAPS-GO. The OAPS-GO/PI composite film with 3.0 wt % OAPS-GO exhibited an 11.2-fold increase in tensile strength, and a 10.4-fold enhancement in tensile modulus compared with neat PI. The dielectric constant (D(k)) decreased with the increasing content of 2D porous OAPS-GO, and a D(k) value of 1.9 was achieved.
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Migration and vascular lumen formation of endothelial cells in cancer cell spheroids of various sizes.
Biomicrofluidics
PUBLISHED: 09-01-2014
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We developed a microfluidic device to culture cellular spheroids of controlled sizes and suitable for live cell imaging by selective plane illumination microscopy (SPIM). We cocultured human umbilical vein endothelial cells (HUVECs) within the spheroids formed by hepatocellular carcinoma cells, and studied the distributions of the HUVECs over time. We observed that the migration of HUVECs depended on the size of spheroids. In the spheroids of ?200??m diameters, HUVECs migrated outwards to the edges within 48 h; while in the spheroids of ?250??m diameters, there was no outward migration of the HUVECs up to 72 h. In addition, we studied the effects of pro-angiogenic factors, namely, vascular endothelial growth factor (VEGF) and fibroblast growth factor (?-FGF), on the migration of HUVECs in the carcinoma cell spheroid. The outward migration of HUVECs in 200??m spheroids was hindered by the treatment with VEGF and ?-FGF. Moreover, some of the HUVECs formed hollow lumen within 72 h under VEGF and ?-FGF treatment. The combination of SPIM and microfluidic devices gives high resolution in both spatial and temporal domains. The observation of HUVECs in spheroids provides us insight on tumor vascularization, an ideal disease model for drug screening and fundamental studies.
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Spin labeling artery method perfusion MRI study of SPG4 and SCA3/MJD.
Magn Reson Imaging
PUBLISHED: 08-28-2014
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Spinocerebellar ataxia type 3 (SCA3) and Machado-Joseph disease (MJD) are similar diseases that are often referred to jointly as SCA3/MJD. As the most common autosomal-dominantly inherited subtype of hereditary spastic paraplegia (HSP), HSP4 (or SPG4) has overlapping symptoms with SCA3/MJD, which hinders their diagnoses. Arterial spin labeling (ASL) is a noninvasive, contrast-agent free, magnetic resonance perfusion imaging method used to obtain maps of the cerebral blood flow (CBF). Here, we investigated the diagnostic value of ASL in SCA3/MJD and SPG4 patients.
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Complex interactions of transcription factors in mediating cytokine biology in T cells.
Immunol. Rev.
PUBLISHED: 08-16-2014
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T-helper (Th) cells play critical roles within the mammalian immune system, and the differentiation of naive CD4(+) T cells into distinct T-helper subsets is critical for normal immunoregulation and host defense. These carefully regulated differentiation processes are controlled by networks of cytokines, transcription factors, and epigenetic modifications, resulting in the generation of multiple CD4(+) T-cell subsets, including Th1, Th2, Th9, Th17, Treg, and Tfh cells. In this review, we discuss the roles of transcription factors in determining the specific type of differentiation and in particular the role of interleukin-2 (IL-2) in promoting or inhibiting Th differentiation. In addition to discussing master regulators and subset-specific transcription factors for distinct T-helper cell populations, we focus on signal transducer and activator of transcription (STAT) proteins and on the cooperative action of interferon regulatory factor 4 (IRF4) with activator protein 1 (AP-1) family proteins and STAT3 in the assembly of complexes that broadly influence T-cell differentiation.
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Spread of carbapenemase-producing enterobacteria in a southwest hospital in China.
Ann. Clin. Microbiol. Antimicrob.
PUBLISHED: 08-12-2014
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The rapid emergence and dissemination of carbapenem resistance in Enterobacteriaceae complicates the treatment of infections caused by these organisms.
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Vomiting and diarrhea in a woman with systemic lupus erythematosus.
J Chin Med Assoc
PUBLISHED: 08-08-2014
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Lupus mesenteric enteritis is an uncommon condition in systemic lupus erythematosus (SLE) patients with acute abdominal pain. We describe a 28-year-old woman with a 3-day history of watery diarrhea and intermittent vomiting. Abdominal ultrasonography revealed thickening of the intestinal wall and edema with the lumen filled with fluid in this patient with nonspecific symptoms. These ultrasonographic findings led the physician to perform an abdominal computed tomography (CT) scan, which revealed typical findings of lupus mesenteric enteritis: intestinal wall thickening with target signs and prominent engorgement of mesenteric vessels with a palisade pattern. After high dose methylprednisolone (1 g/day intravenously) was administered for 3 days, the patient's symptoms markedly improved. Additionally, resolution of the mural thickening was observed within 1 week by abdominal ultrasound examinations. Our experience indicated that abdominal ultrasonography can be important in the correct diagnosis of lupus mesenteric vasculitis (LMV).
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A polydimethylsiloxane-polycarbonate hybrid microfluidic device capable of generating perpendicular chemical and oxygen gradients for cell culture studies.
Lab Chip
PUBLISHED: 08-07-2014
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This paper reports a polydimethylsiloxane-polycarbonate (PDMS-PC) hybrid microfluidic device capable of performing cell culture under combinations of chemical and oxygen gradients. The microfluidic device is constructed of two PDMS layers with microfluidic channel patterns separated by a thin PDMS membrane. The top layer contains an embedded PC film and a serpentine channel for a spatially confined oxygen scavenging chemical reaction to generate an oxygen gradient in the bottom layer for cell culture. Using the chemical reaction method, the device can be operated with a small amount of chemicals, without bulky gas cylinders and sophisticated flow control schemes. Furthermore, it can be directly used in conventional incubators with syringe pumps to simplify the system setup. The bottom layer contains arrangements of serpentine channels for chemical gradient generation and a cell culture chamber in the downstream. The generated chemical and oxygen gradients are experimentally characterized using a fluorescein solution and an oxygen-sensitive fluorescent dye, respectively. For demonstration, a 48 hour cell-based drug test and a cell migration assay using human lung adenocarcinoma epithelial cells (A549) are conducted under various combinations of the chemical and oxygen gradients in the experiments. The drug testing results show an increase in A549 cell apoptosis due to the hypoxia-activated cytotoxicity of tirapazamine (TPZ) and also suggest great cell compatibility and gradient controllability of the device. In addition, the A549 cell migration assay results demonstrate an aerotactic behavior of the A549 cells and suggest that the oxygen gradient plays an essential role in guiding cell migration. The migration results, under combinations of chemokine and oxygen gradients, cannot be simply superposed with single gradient results. The device is promising to advance the control of in vitro microenvironments, to better study cellular responses under various physiological conditions for biomedical applications.
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[Study of the effect of heat source separation distance on plasma physical properties in laser-pulsed GMAW hybrid welding based on spectral diagnosis technique].
Guang Pu Xue Yu Guang Pu Fen Xi
PUBLISHED: 08-07-2014
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In the present paper, the authors calculated the plasma's peak electron temperatures under different heat source separation distance in laser- pulse GMAW hybrid welding based on Boltzmann spectrometry. Plasma's peak electron densities under the corresponding conditions were also calculated by using the Stark width of the plasma spectrum. Combined with high-speed photography, the effect of heat source separation distance on electron temperature and electron density was studied. The results show that with the increase in heat source separation distance, the electron temperatures and electron densities of laser plasma did not changed significantly. However, the electron temperatures of are plasma decreased, and the electron densities of are plasma first increased and then decreased.
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Smoking, drinking, and pancreatitis: a population-based cohort study in Taiwan.
Pancreas
PUBLISHED: 08-02-2014
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In Western population, smoking is a dose-dependent risk factor for pancreatitis, whereas a threshold of 5 drinks per day may exist for alcohol to increase pancreatitis risk. Given ethnic differences in tobacco and alcohol metabolism, we examined the associations between smoking, alcohol, and pancreatitis in Asians.
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DynamicBC: A MATLAB Toolbox for Dynamic Brain Connectome Analysis.
Brain Connect
PUBLISHED: 08-02-2014
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Abstract The brain connectome collects the complex network architectures, looking at both static and dynamic functional connectivity. The former normally requires stationary signals and connections. However, the human brain activity and connections are most likely time dependent and dynamic, and related to ongoing rhythmic activity. We developed an open-source MATLAB toolbox DynamicBC with user-friendly graphical user interfaces, implementing both dynamic functional and effective connectivity for tracking brain dynamics from functional MRI. We provided two strategies for dynamic analysis: (1) the commonly utilized sliding-window analysis and (2) the flexible least squares based time-varying parameter regression strategy. The toolbox also implements multiple functional measures including seed-to-voxel analysis, region of interest (ROI)-to-ROI analysis, and voxel-to-voxel analysis. We describe the principles of the implemented algorithms, and then present representative results from simulations and empirical data applications. We believe that this toolbox will help neuroscientists and neurologists to easily map dynamic brain connectomics.
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Relationship Between Sexual Compulsivity and Sexual Risk Behaviors Among Chinese Sexually Active Males.
Arch Sex Behav
PUBLISHED: 07-17-2014
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Compulsivity is defined as "an insistent, repetitive, intrusive, and unwanted urge to perform specific acts often in ritualized or routinized fashions." Sexual compulsivity has been shown to be associated with some high risk sexual behaviors related to HIV and sexually transmitted infection (STI). In some Western countries, the 10-item Sexual Compulsivity Scale (SCS) has been developed to assess people's sexual compulsivity but no Chinese version has been validated. This study validated the Chinese version of the SCS and investigated its associations with specific sexual behaviors. In 2008, a random telephone survey was conducted in the sexually active male general population in Hong Kong, interviewing 1,048 participants. The Chinese version of the SCS was found to be internally consistent (Cronbach's ? = 0.88 for the overall scale), with a mean total score of 20.7 (SD = 4.7). An exploratory factor analysis procedure extracted two factors that were named Controllability and Functional Consequences. Higher SCS scores were associated with multiple female sexual partnerships in the last 6 months, having had sex with either non-regular partner(s) or female sex worker(s) in the last 6 months, having contracted STI in the last 6 months, and inconsistent condom use with either non-regular partner(s) or female sex worker(s) in the last 6 months. The scale can be used to assess sexual compulsivity among sexually active Chinese men in Hong Kong. It can potentially be used in other Chinese communities. Further confirmatory studies are warranted.
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Arsenic modulates posttranslational S-nitrosylation and translational proteome in keratinocytes.
ScientificWorldJournal
PUBLISHED: 07-08-2014
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Arsenic is a class I human carcinogen (such as inducing skin cancer) by its prominent chemical interaction with protein thio (-SH) group. Therefore, arsenic may compromise protein S-nitrosylation by competing the -SH binding activity. In the present study, we aimed to understand the influence of arsenic on protein S-nitrosylation and the following proteomic changes. By using primary human skin keratinocyte, we found that arsenic treatment decreased the level of protein S-nitrosylation. This was coincident to the decent expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS). By using LC-MS/MS, around twenty S-nitrosoproteins were detected in the biotin-switched eluent. With the interest that arsenic not only regulates posttranslational S-nitrosylation but also separately affects protein's translation expression, we performed two-dimensional gel electrophoresis and found that 8 proteins were significantly decreased during arsenic treatment. Whether these decreased proteins are the consequence of protein S-nitrosylation will be further investigated. Taken together, these results provide a finding that arsenic can deplete the binding activity of NO and therefore reduce protein S-nitrosylation.
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DCE-MRI assessment of the effect of Epstein-Barr virus-encoded latent membrane protein-1 targeted DNAzyme on tumor vasculature in patients with nasopharyngeal carcinomas.
BMC Cancer
PUBLISHED: 07-02-2014
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EBV-encoded latent membrane protein 1 (EBV-LMP1) is an important oncogenic protein for nasopharyngeal carcinoma (NPC) and has been shown to engage a plethora of signaling pathways. Correspondingly, an LMP1-targeted DNAzyme was found to inhibit the growth of NPC cells both in vivo and in vitro by suppressing cell proliferation and inducing apoptosis. However, it remains unknown whether an LMP1-targeted DNAzyme would affect the vasculature of NPC. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been applied in the clinical trials of anti-angiogenic drugs for more than ten years, and Ktrans has been recommended as a primary endpoint. Therefore, the objective of the current study was to use DCE-MRI to longitudinally study the effect of an EBV-LMP1-targeted DNAzyme on the vasculature of patients with NPC.
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Lightweight and flexible reduced graphene oxide/water-borne polyurethane composites with high electrical conductivity and excellent electromagnetic interference shielding performance.
ACS Appl Mater Interfaces
PUBLISHED: 06-27-2014
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In this study, we developed a simple and powerful method to fabricate flexible and lightweight graphene-based composites that provide high electromagnetic interference (EMI) shielding performance. Electrospun waterborne polyurethane (WPU) that featured sulfonate functional groups was used as the polymer matrix, which was light and flexible. First, graphene oxide (GO)/WPU composites were prepared through layer-by-layer (L-b-L) assembly of two oppositely charged suspensions of GO, the cationic surfactant (didodecyldimethylammonium bromide, DDAB)-adsorbed GO and intrinsic negatively charged GO, depositing on the negatively charged WPU fibers. After the L-b-L assembly cycles, the GO bilayers wrapped the WPU fiber matrix completely and revealed fine connections guided by the electrospun WPU fibers. Then, we used hydroiodic acid (HI) to obtain highly reduced GO (r-GO)/WPU composites, which exhibited substantially enhanced electrical conductivity (approximately 16.8 S/m) and, moreover, showed a high EMI-shielding effectiveness (approximately 34 dB) over the frequency range from 8.2 to 12.4 GHz.
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Altered regional homogeneity in rolandic epilepsy: a resting-state FMRI study.
Biomed Res Int
PUBLISHED: 06-18-2014
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Children with rolandic epilepsy (RE) are often associated with cognitive deficits and behavioral problems. Findings from neurophysiological and neuroimaging studies in RE have now demonstrated dysfunction not only in rolandic focus, but also in distant neuronal circuits. Little is known, however, about whether there is distributed abnormal spontaneous brain activity in RE. Using resting-state functional magnetic resonance imaging (RS-fMRI), the present study aimed to determine whether children with RE show abnormal local synchronization during resting state and, if so, whether these changes could be associated with the behavioral/clinical characteristics of RE. Regional homogeneity (ReHo) in children with RE (n = 30) and healthy children (n = 20) was computed on resting-state functional MRI data. In comparison with healthy children, children with RE showed increased ReHo in the central, premotor, and prefrontal regions, while they showed decreased ReHo in bilateral orbitofrontal cortex and temporal pole. In addition, the ReHo value in the left orbitofrontal cortex negatively was corrected with performance intelligence quotient in the children with RE. The aberrant local synchronization, not strictly related to primary site of the typical rolandic focus, indicates the neuropathophysiological mechanism of RE. The study findings may shed new light on the understanding of neural correlation of neuropsychological deficiencies in the children with RE.
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Asymmetric synthesis of functionalized dihydronaphthoquinones containing quaternary carbon centers via a metal-free catalytic intramolecular acylcyanation of activated alkenes.
Org. Lett.
PUBLISHED: 06-09-2014
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A novel metal-free catalytic annulation was developed through a Lewis base-catalyzed asymmetric allylic alkylation and the ensuing unprecedented asymmetric intramolecular acylcyanation of alkenes. This protocol provides a unique and facile access to prepare enantioenriched densely functionalized dihydronaphthoquinones accompanied by enantiomerically pure 3,3-disubstituted phthalides bearing quaternary carbon centers.
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Synthesis and biological evaluation of a novel class of coumarin derivatives.
Bioorg. Med. Chem. Lett.
PUBLISHED: 06-08-2014
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In this study, several novel coumarin derivatives, 7-hydroxy-2-oxo-2H-chromene-3-carboxyl-Trp-Trp-AA-OBzl compounds, were designed and synthesized as potential anticancer agents. Their in vitro cytotoxic activities were evaluated using methylthiazoltetrazolium (MTT) assay. The anti-tumor activity of the newly coumarin derivatives was determined in a S180 bearing mouse model and some of the compounds demonstrated tumor growth inhibition similar to the positive control, doxorubicin. Compared to doxorubicin, most of the compounds exhibited enhanced immunologic function suggesting a relatively minor toxic effect. The intercalation of the coumarin derivatives synthesized with calf thymus (CT) DNA was also studied.
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Mechanisms of the PtCl2-catalyzed intramolecular cyclization of o-isopropyl-substituted aryl alkynes for the synthesis of indenes and comparison of three sp3 C-H bond activation modes.
J. Org. Chem.
PUBLISHED: 05-27-2014
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Chatani and He respectively reported an efficient way to synthesize indenes through PtCl2 catalyzed sp(3) C-H bond activation. Interestingly, the R group (R = H or Br) in the alkyne moiety of the substrates in Chatani's experiments migrates to the C3 position in indenes, whereas the R group (R = Ar) stays in the original C2 position of final indenes in He's experiments. DFT calculations indicated that there are two competing pathways a and c for the cyclization reaction. Pathway a involves [1,2]-R migration, [1,5]-H shift, and 4?-electrocyclization, giving the indenes with the R group at the C3 position. Pathway c takes place through irreversible [1,5]-H shift/cyclization and [1,2]-H shift, generating indenes with the R group at the C2 position. DFT calculations found that, when R = H or Br, pathway a is favored. When R = alkyl group, the [1,2]-R migration is difficult and pathway c is preferred. When R = Ar, DFT calculations predicted and experiments verified that both pathways a and c occur to give two indene products. Comparison of different models of sp(3) C-H activations has been presented to guide further understanding and prediction of new C-H bond activations.
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Endoscopic ultrasonography assessment of para-esophageal varices predicts efficacy of propranolol in preventing recurrence of esophageal varices.
J. Gastroenterol.
PUBLISHED: 05-20-2014
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Volume of para-esophageal varices (PEV) correlates with esophageal varices recurrence. The effect of propranolol on volumetric change of PEV has not been studied. The relation between EV recurrence and volumetric change of PEV in patients undergoing endoscopic variceal ligation (EVL) with and without propranolol are studied.
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Lipid profiling and corresponding biodiesel quality of Mortierella isabellina using different drying and extraction methods.
Bioresour. Technol.
PUBLISHED: 05-10-2014
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Four lipid extraction methods (Bligh & Dyer, hexane & isopropanol, dichloromethane & methanol, and hexane) were evaluated to extract lipid from freeze- and oven-dried fungus Mortierella isabellina ATCC42613. The highest lipid yield (41.8%) was obtained from Bligh & Dyer extraction on the oven-dried fungal biomass with a methanol:chloroform:water ratio of 2:1:0.8. Other lipid extraction methods on both freeze- and oven-dried samples had lipid yields ranging from 20.7% to 35.9%. Non-polar lipid was the main lipid class (more than 90% of total lipid) in M. isabellina. Regarding fatty acid profile, there was no significant difference on fatty acid concentration between different drying and extraction methods. Estimation of biodiesel fuel properties using correlative models further demonstrated that the fungal biodiesel is a good alternative to fossil diesel.
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Nucleophilic phosphine-catalyzed intramolecular Michael reactions of N-allylic substituted ?-amino nitriles: construction of functionalized pyrrolidine rings via 5-endo-trig cyclizations.
J. Org. Chem.
PUBLISHED: 05-05-2014
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Pyrrolidine rings are common moieties for pharmaceutical candidates and natural compounds, and the construction of these skeletons has received much attention. ?-Amino nitriles are versatile intermediates in synthetic chemistry and have been widely used in the generation of multiple polyfunctional structures. Herein, a novel nucleophilic phosphine-catalyzed intramolecular Michael reaction of N-allylic substituted ?-amino nitriles has been developed for the efficient construction of functionalized 2,4-disubstituted pyrrolidines (N-heterocyclic ?-amino nitriles) via 5-endo-trig cyclization. Furthermore, the one-pot sequence of the synthesis of pyrrolidine and the subsequent transformations of the functionalized products have also been demonstrated.
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Abnormal functional connectivity density in psychogenic non-epileptic seizures.
Epilepsy Res.
PUBLISHED: 04-14-2014
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Psychogenic non-epileptic seizures (PNES) are paroxysmal behaviors that resemble epileptic seizures but lack abnormal electrical activity. Some neuroimaging studies have reported that PNES exhibits aberrant functional connectivity in specific brain networks. Thus, advanced neuroimaging technologies may aid clinical diagnosis and treatment of PNES.
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Polygonum cuspidatum extracts as bioactive antioxidaion, anti-tyrosinase, immune stimulation and anticancer agents.
J. Biosci. Bioeng.
PUBLISHED: 03-28-2014
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In our study, it was applied for the technology of supercritical fluid carbon dioxide extraction to achieve biological constitutes from a Taiwan native plant, Polygonum cuspidatum. We developed bioactive effects of P. cuspidatum extracts via multiple examinations that established bio-purposes at a range of dosage ranges. The research of P. cuspidatum extracts indicated that they possessed anti-oxidative properties on radical-scavenging abilities, reducing activities and metal chelating powers in dose-dependant manners. The extracts also had minor in vitro mushroom tyrosinase suppression and decreased cellular tyrosinase activities and melanin production in B16-F10 cells. Immunologically, P. cuspidatum extracts enhanced the release of tumor necrosis factor ? (TNF-?) induced by THP-1 macrophage cell line. In addition, the cell proliferation showed anti-proliferation in dose-dependent manner on human skin melanoma cells, A375 and A375.S2, of the extracts suggesting biological constitutes employed the anti-cancer possessions. This is the first statement presenting bioactivities on P. cuspidatum extracts including anti-oxidation, immune stimulation, anti-tyrosinase and anti-melanoma as far as we know.
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Association between obstructive sleep apnea and deep vein thrombosis / pulmonary embolism: a population-based retrospective cohort study.
Thromb. Res.
PUBLISHED: 03-26-2014
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Obstructive sleep apnea (OSA) is a major contributor to cardiovascular disease, and may cause severe morbidity and mortality. Recent studies have indicated that OSA patients exhibited elevated platelet activity, fibrinogen levels, and platelet aggregation.
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Oleaginous fungal lipid fermentation on combined acid- and alkali-pretreated corn stover hydrolysate for advanced biofuel production.
Bioresour. Technol.
PUBLISHED: 03-17-2014
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A combined hydrolysis process, which first mixed dilute acid- and alkali-pretreated corn stover at a 1:1 (w/w) ratio, directly followed by enzymatic saccharification without pH adjustment, has been developed in this study in order to minimize the need of neutralization, detoxification, and washing during the process of lignocellulosic biofuel production. The oleaginous fungus Mortierella isabellina was selected and applied to the combined hydrolysate as well as a synthetic medium to compare fungal lipid accumulation and biodiesel production in both shake flask and 7.5L fermentor. Fungal cultivation on combined hydrolysate exhibited comparable cell mass and lipid yield with those from synthetic medium, indicating that the integration of combined hydrolysis with oleaginous fungal lipid fermentation has great potential to improve performance of advanced lignocellulosic biofuel production.
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Inhibition of Notch signaling facilitates the differentiation of human-induced pluripotent stem cells into neural stem cells.
Mol. Cell. Biochem.
PUBLISHED: 03-14-2014
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Neural stem cells (NSCs) derived from induced pluripotent stem cells (iPSCs) are becoming an appealing source of cell-based therapies of brain diseases. As such, it is important to understand the molecular mechanisms that regulate the differentiation of iPSCs toward NSCs. It is well known that Notch signaling governs the retention of stem cell features and drives stem cells fate. However, further studies are required to investigate the role of Notch signaling in the NSCs differentiation of iPSCs. In this study, we successfully generated NSCs from human iPSCs using serum-free medium supplemented with retinoic acid (RA) in vitro. We then assessed changes in the expression of Notch signaling-related molecules and some miRNAs (9, 34a, 200b), which exert their regulation by targeting Notch signaling. Moreover, we used a ?-secretase inhibitor (DAPT) to disturb Notch signaling. Data revealed that the levels of the Notch signaling-related molecules decreased, whereas those miRNAs increased, during this differentiation process. Inhibition of Notch signaling accelerated the formation of the neural rosette structures and the expression of NSC and mature neurocyte marker genes. This suggests that Notch signaling negatively regulated the neuralization of human iPSCs, and that this process may be regulated by some miRNAs.
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Impact of environmental noise on growth and neuropsychological development of newborn rats.
Anat Rec (Hoboken)
PUBLISHED: 03-07-2014
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We aimed to investigate the effects of environmental noise exposure on the growth and neuropsychological development in neonatal rats. Twenty-four postnatal 7-day-old Sprague-Dawley rats were randomly assigned into control, high-noise and reduced noise groups. The rats in the high-noise group were exposed to 90 dB white noise, and those in the control group were grown under standard condition, while those in the reduced noise group were exposed to standard condition with sound-absorbing cotton. Ten, 15, and 20 days post noise exposure, both the body weight and length of the rats in high-noise group were lower than those in the control and reduced noise groups, respectively. The secretion of growth hormone was significantly decreased in the rats exposed to high noise environment, compared to those exposed to standard condition and reduced noise. More interestingly, the swimming distance was apparently increased and the swimming speed was significantly decreased in high-noise group compared with those in control and reduced noise groups. Importantly, the mRNA and protein levels of SYP in the rats hippocampus were significantly decreased in high-noise group compare with those in control and reduced noise groups. Similarly, the positive expression of SYP in the CA1 region of hippocampus was also significantly decreased in the high noise group rats. In conclusion, our results demonstrated that high noise exposure could decrease the production of growth hormone and SYP in neonatal rats, which may retard the growth of weight and length and the capability of learning and memory.
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Amplification of B cell receptor-Erk signaling by Rasgrf-1 overexpression in chronic lymphocytic leukemia.
Leuk. Lymphoma
PUBLISHED: 03-07-2014
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Rasgrf-1 is a guanine exchange factor (GEF) that catalyzes the exchange of GDP for GTP. In a RNA microarray analysis of chronic lymphocytic leukemia (CLL) specimens (n = 5), this gene was found to be overexpressed in CLL as compared to normal peripheral blood mononuclear cell (PBMC) CD19 + B cells (n = 3). CLL specimens (n = 29) expressed Rasgrf-1 RNA at levels 5-300-fold higher as compared to normal B cells. CLL specimens expressed a 75 kDa isoform that was smaller than the expected full-length protein (140 kDa) and the truncated variant had higher GEF activity. Knockdown of Rasgrf-1 in CLL specimens inhibited active GTP-bound Ras and the Ras/Erk/mitogen-activated protein kinase (MAPK) pathway. Rasgrf-1 was phosphorylated and activated by B cell receptor (BCR) signaling that increased its GEF function, and this phosphorylation was blocked by Src and Bruton's tyrosine kinase (BTK) inhibitors. Rasgrf-1 is a novel GEF protein that has a role in BCR signaling and its overexpression further activates the Ras/Erk/MAPK pathway in CLL specimens.
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Investigations of kanuka and manuka essential oils for in vitro treatment of disease and cellular inflammation caused by infectious microorganisms.
J Microbiol Immunol Infect
PUBLISHED: 03-04-2014
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Diseases caused by infectious and inflammatory microorganisms are among the most common and most severe nosocomial diseases worldwide. Therefore, developing effective agents for treating these illnesses is critical. In this study, essential oils from two tea tree species, kanuka (Kunzea ericoides) and manuka (Leptospermum scoparium), were evaluated for use in treating diseases and inflammation caused by microorganism infection.
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Generalized tonic-clonic seizures: aberrant interhemispheric functional and anatomical connectivity.
Radiology
PUBLISHED: 03-01-2014
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To characterize interhemispheric functional and anatomic connectivity in patients with idiopathic generalized epilepsy and generalized tonic-clonic seizures (GTCS).
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Effects of low-level laser therapy on M1-related cytokine expression in monocytes via histone modification.
Mediators Inflamm.
PUBLISHED: 02-19-2014
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Low-level laser therapy (LLLT) has been used in the treatment of radiotherapy-induced oral mucositis and allergic rhinitis. However, the effects of LLLT on human monocyte polarization into M1 macrophages are unknown. To evaluate the effects of LLLT on M1-related cytokine and chemokine production and elucidate the mechanism, the human monocyte cell line THP-1 was treated with different doses of LLLT. The expression of M1-related cytokines and chemokines (CCL2, CXCL10, and TNF-?) was determined by ELISA and real-time PCR. LLLT-associated histone modifications were examined by chromatin immunoprecipitation (ChIP) assays. Mitochondrial involvement in the LLLT-induced M1-related cytokine expression was evaluated by quantitative real-time PCR. Flow cytometry was used to detect the cell surface markers for monocyte polarization. The results showed that LLLT (660?nm) significantly enhanced M1-related cytokine and chemokine expression in mRNA and protein levels. Mitochondrial copy number and mRNA levels of complex I-V protein were increased by LLLT (1?J/cm(2)). Activation of M1 polarization was concomitant with histone modification at TNF-? gene locus and IP-10 gene promoter area. This study indicates that LLLT (660?nm) enhanced M1-related cytokine and chemokine expression via mitochondrial biogenesis and histone modification, which may be a potent immune-enhancing agent for the treatment of allergic diseases.
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Opposing actions of IL-2 and IL-21 on Th9 differentiation correlate with their differential regulation of BCL6 expression.
Proc. Natl. Acad. Sci. U.S.A.
PUBLISHED: 02-18-2014
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Interleukin 9 (IL-9) is a ?c-family cytokine that is highly produced by T-helper 9 (Th9) cells and regulates a range of immune responses, including allergic inflammation. Here we show that IL-2-JAK3-STAT5 signaling is required for Th9 differentiation, with critical STAT5 binding sites in the Il9 (the gene encoding IL-9) promoter. IL-2 also inhibited B cell lymphoma 6 (BCL6) expression, and overexpression of BCL6 impaired Th9 differentiation. In contrast, IL-21 induced BCL6 and diminished IL-9 expression in wild-type but not Bcl6(-/-) cells, and Th9 differentiation was increased in Il21(-/-) and Il21r(-/-) T cells. Interestingly, BCL6 bound in proximity to many STAT5 and STAT6 binding sites, including at the Il9 promoter. Moreover, there was increased BCL6 and decreased STAT binding at this site in cells treated with blocking antibodies to IL-2 and the IL-2 receptor, suggesting a possible BCL6-STAT5 binding competition that influences IL-9 production. BCL6 binding was also increased when cells were Th9-differentiated in the presence of IL-21. Thus, our data reveal not only direct IL-2 effects via STAT5 at the Il9 gene, but also opposing actions of IL-2 and IL-21 on BCL6 expression, with increased BCL6 expression inhibiting IL-9 production. These data suggest a model in which increasing BCL6 expression decreases efficient Th9 differentiation, indicating possible distinctive approaches for controlling this process.
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Diagnostic Impact of Color Doppler Ultrasound-Guided Core Biopsy on Fine-Needle Aspiration of Anterior Mediastinal Masses.
Ultrasound Med Biol
PUBLISHED: 02-12-2014
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Although lymphoma and thymoma are common etiologies of anterior mediastinal masses (AMMs), smaller percentages and numbers of patients with these diseases have been enrolled in previous ultrasound-guided biopsy studies. To date, there has been no study of color Doppler sonographic features to support the differentiation of AMMs. For this retrospective cohort study, a search of the database of the China Medical University Hospital using the clinical coding "ultrasound-guided biopsy" was conducted for the period December 2003 to February 2013. We selected patients diagnosed with AMMs (not cysts) using radiographic records. This search yielded a list of 80 cases. Real-time ultrasound-guided core needle biopsy (CNB) was performed in all but 5 patients without a sufficient safety range. In 89% (67/75) of these ultrasound-guided CNB cases, the diagnostic accuracy achieved subclassification. Fine-needle aspiration cytology achieved subclassification in only 10% of cases. On color Doppler sonography, 71% of lymphomas were characterized as "rich vascular with central/crisscross collocations" and 29% as "avascular or localized/scattered peripheral vessels." However, decreased proportions of "rich vascular with central/crisscross collocations" were found in lung cancer (4% [1/23], odds ratio = 0.018, 95% confidence interval: 0.002-0.154, p < 0.001) and thymoma/thymic carcinoma (25% [4/16]; odds ratio = 0.133, 95% confidence interval: 0.035-0.514, p = 0.003) compared with the lymphoma group. We conclude that the vessels in lymphoma AMMs have specific patterns on color Doppler sonography. Ultrasound-guided CNB of AMMs had an accuracy of ?89% in diagnosis and subclassification. Fine-needle aspiration cytology itself cannot aid in the diagnosis. Color Doppler sonographic evaluation of AMMs followed by real-time CNB is a more efficient method.
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Serum levels of procalcitonin as a biomarker for differentiating between sepsis and systemic inflammatory response syndrome in the neurological intensive care unit.
J Clin Neurosci
PUBLISHED: 02-11-2014
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We explored the value of procalcitonin (PCT) to differentiate sepsis from systemic inflammatory response syndrome (SIRS), and determine sepsis severity in the neurological intensive care unit (NICU). Blood samples were measured for C-reactive protein (CRP) and PCT levels upon NICU admission, on the day of diagnosis of SIRS or sepsis, and at 3 and 7 days after diagnosis. We found that there were significant differences in serum levels of CRP and PCT as well as Glasgow Coma Scale (GCS) score upon admission between the SIRS and sepsis groups (p<0.05). CRP and white blood cell levels were not significantly different when attempting to differentiate sepsis severity (p>0.05). Multiple comparisons showed that significant differences in serum PCT levels were observed between sepsis and severe sepsis groups, as well as sepsis and septic shock groups (p<0.05). We obtained the highest sensitivity and specificity for SIRS and sepsis with cut-off values of 2 ng/mL for PCT, 44 mg/dL for CRP, and 4 for the GCS. There were no differences in CRP and PCT levels between cerebrovascular disease and non-cerebrovascular disease groups (p>0.05). No differences were found between viral and bacterial meningitis groups (p>0.05). PCT levels are valuable in discriminating sepsis from SIRS and determining sepsis severity in critically ill patients with neurological disease.
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Frequency-dependent amplitude alterations of resting-state spontaneous fluctuations in idiopathic generalized epilepsy.
Epilepsy Res.
PUBLISHED: 01-24-2014
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Amplitude of low-frequency fluctuation (ALFF) of blood-oxygenation level-dependent (BOLD) has proven a promising way to detect disease-related local brain activity. However, routine approach employs an arbitrary frequency band of 0.01-0.08 Hz, which lacks frequency specificity and blinds to the information contained in other frequency bands. This study investigated the amplitude of fluctuations in full BOLD frequency bands, and addressed how amplitudes of fluctuations change in each specific frequency range in idiopathic generalized epilepsy (IGE).
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Distinct and concurrent pathways of Pol II- and Pol IV-dependent siRNA biogenesis at a repetitive trans-silencer locus in Arabidopsis thaliana.
Plant J.
PUBLISHED: 01-06-2014
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Short interfering RNAs (siRNAs) homologous to transcriptional regulatory regions can induce RNA-directed DNA methylation (RdDM) and transcriptional gene silencing (TGS) of target genes. In our system, siRNAs are produced by transcribing an inverted DNA repeat (IR) of enhancer sequences, yielding a hairpin RNA that is processed by several Dicer activities into siRNAs of 21-24 nt. Primarily 24-nt siRNAs trigger RdDM of the target enhancer in trans and TGS of a downstream GFP reporter gene. We analyzed siRNA accumulation from two different structural forms of a trans-silencer locus in which tandem repeats are embedded in the enhancer IR and distinguished distinct RNA polymerase II (Pol II)- and Pol IV-dependent pathways of siRNA biogenesis. At the original silencer locus, Pol-II transcription of the IR from a 35S promoter produces a hairpin RNA that is diced into abundant siRNAs of 21-24 nt. A silencer variant lacking the 35S promoter revealed a normally masked Pol IV-dependent pathway that produces low levels of 24-nt siRNAs from the tandem repeats. Both pathways operate concurrently at the original silencer locus. siRNAs accrue only from specific regions of the enhancer and embedded tandem repeat. Analysis of these sequences and endogenous tandem repeats producing siRNAs revealed the preferential accumulation of siRNAs at GC-rich regions containing methylated CG dinucleotides. In addition to supporting a correlation between base composition, DNA methylation and siRNA accumulation, our results highlight the complexity of siRNA biogenesis at repetitive loci and show that Pol II and Pol IV use different promoters to transcribe the same template.
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A comprehensive resource of genomic, epigenomic and transcriptomic sequencing data for the black truffle Tuber melanosporum.
Gigascience
PUBLISHED: 01-01-2014
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Tuber melanosporum, also known in the gastronomic community as "truffle", features one of the largest fungal genomes (125 Mb) with an exceptionally high transposable element (TE) and repetitive DNA content (>58%). The main purpose of DNA methylation in fungi is TE silencing. As obligate outcrossing organisms, truffles are bound to a sexual mode of propagation, which together with TEs is thought to represent a major force driving the evolution of DNA methylation. Thus, it was of interest to examine if and how T. melanosporum exploits DNA methylation to maintain genome integrity.
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NK/T cell lymphoma involving mediastinum: report of a case and review of literature.
Int J Clin Exp Pathol
PUBLISHED: 01-01-2014
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Extranodal natural killer (NK)/T-cell lymphoma is a very aggressive malignant neoplasia with a poor prognosis. Herein we reported a case of NK/T cell lymphoma involving mediastinum. It was a 28-year-old Chinese male patient. The tumor cells were medium-sized, had irregularly folded nuclei, and inconspicuous or small nucleoli with coagulative necrosis. The tumor cells were positive for CD3?, TIA-1, but negative for CD56. In situ hybridization revealed that tumor cells also expressed Epstein-Barr virus encoded RNA. To our knowledge, this is the first case of NK/T cell lymphoma involving mediastinum.
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Alterations in low-level perceptual networks related to clinical severity in PTSD after an earthquake: a resting-state fMRI study.
PLoS ONE
PUBLISHED: 01-01-2014
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Several task-based functional MRI (fMRI) studies have highlighted abnormal activation in specific regions involving the low-level perceptual (auditory, visual, and somato-motor) network in posttraumatic stress disorder (PTSD) patients. However, little is known about whether the functional connectivity of the low-level perceptual and higher-order cognitive (attention, central-execution, and default-mode) networks change in medication-naïve PTSD patients during the resting state.
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Accuracy of faecal occult blood test and Helicobacter pylori stool antigen test for detection of upper gastrointestinal lesions.
BMJ Open
PUBLISHED: 11-02-2013
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Highly sensitive guaiac-based faecal occult blood (Hemoccult SENSA) and Helicobacter pylori stool antigen testing might help detect upper gastrointestinal lesions when appended to a colorectal cancer screening programme with faecal immunochemical testing. We evaluated the diagnostic accuracies of two stool tests in detecting upper gastrointestinal lesions.
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Comparative effectiveness of renin-angiotensin system blockers and other antihypertensive drugs in patients with diabetes: systematic review and bayesian network meta-analysis.
BMJ
PUBLISHED: 10-26-2013
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To assess the effects of different classes of antihypertensive treatments, including monotherapy and combination therapy, on survival and major renal outcomes in patients with diabetes.
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Lewis base catalyzed asymmetric substitution/Diels-Alder cascade reaction: a rapid and efficient construction of enantioenriched diverse tricyclic heterocycles.
Org. Biomol. Chem.
PUBLISHED: 09-16-2013
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The first tertiary amine catalyzed asymmetric allylic amination/cycloaddition cascade sequence has been developed, which provided a novel protocol to construct enantioenriched azapolyheterocycles under mild reaction conditions efficiently (up to 95% ee, endo/exo >20:1).
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Adjuvant treatments for resected pancreatic adenocarcinoma: a systematic review and network meta-analysis.
Lancet Oncol.
PUBLISHED: 09-12-2013
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Major adjuvant treatments for pancreatic adenocarcinoma include fluorouracil, gemcitabine, chemoradiation, and chemoradiation plus fluorouracil or gemcitabine. Since the optimum regimen remains inconclusive, we aimed to compare these treatments in terms of overall survival after tumour resection and in terms of grade 3-4 toxic effects with a systematic review and random-effects Bayesian network meta-analysis.
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Mannose-binding lectin gene polymorphisms and mycobacterial lymphadenitis in young patients.
Pediatr. Infect. Dis. J.
PUBLISHED: 09-07-2013
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Tuberculosis (TB) has recently re-emerged as a major public health threat worldwide. There is strong evidence that host genetic factors influence individual susceptibility to TB and that, once infected, young children and immunocompromised patients are at increased risk for mycobacterial disease and progression to extrapulmonary lymphadenitis.
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Toxic effects of triclosan on the detoxification system and breeding of Daphnia magna.
Ecotoxicology
PUBLISHED: 08-30-2013
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The toxic effects of different concentrations of Triclosan (TCS) (1-128 ?g/L) on Daphnia magna (D. magna) were investigated by acute (48 h) and chronic (21-day) toxicity tests. The response of antioxidase system and Phase I metabolism process of D. magna exposed to TCS were investigated by measuring a series of biomarkers including glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), 7-ethoxyresorufin O-deethylase (EROD), Erythromycin N-demethylase (ERND) and Aminopyrine N-demethylase (APND). The 48 h LC50 of TCS was 330 ?g/L for D. magna. In the chronic test, total number of neonates per female, body length and the intrinsic rate of natural increase (r) of D. magna increased at the low exposure concentrations (1-16 ?g/L) and decreased at the high concentrations (64-128 ?g/L), while the total number of molting per adult decreased continually. The GST and CAT activities showed no significant increase in all treatments, and SOD activities were induced after 24-h exposure and inhibited after 48-h exposure at 4-128 ?g/L of concentrations. The MDA content increased after 6-h exposure but decreased after 48-h exposure at 4-128 ?g/L. EROD activities initially increased after 6-h exposure, but decreased after 24 and 48-h exposure, ERND and APND activities showed a similar temporal pattern among different treatments groups. SOD, MDA and APND were sensitive to TCS, thus they are suitable as potential biomarkers for the exposure to TCS.
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Fabrication of spherical mitigation pit on KH2PO4 crystal by micro-milling and modeling of its induced light intensification.
Opt Express
PUBLISHED: 08-14-2013
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Micro-machining is the most promising method for KH(2)PO(4) crystal to mitigate the surface damage growth in high power laser system. In this work, spherical mitigation pit is fabricated by micro-milling with an efficient machining procedure. The light intensification caused by rear surface features before and after mitigation is numerically modeled based on the finite-difference time-domain method. The results indicate that the occurrence of total internal reflections should be responsible for the largest light intensification inside the crystal. For spherical pits after mitigation, the light intensification can be greatly alleviated by preventing the occurrence of total internal reflections. The light intensification caused by spherical mitigation pit is strongly dependent on the width-depth ratio and it is suggested that the width-depth ratio of spherical mitigation pit must be devised to be larger than 5.0 to achieve the minimal light intensification for the mitigation of surface damage growth. Laser damage tests for KH(2)PO(4) crystal validate that the laser damage resistance of initially damaged surface can be retrieved to near the level of ideal surface by replacing initial damage site with predesigned mitigation pit.
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N-terminal prohormone B-type natriuretic peptide and weaning outcome in postoperative patients with pulmonary complications.
J. Int. Med. Res.
PUBLISHED: 08-01-2013
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To evaluate the relationship between plasma N-terminal prohormone B-type natriuretic peptide (NT-proBNP) and weaning outcomes, and the ability of NT-proBNP level to predict weaning success, in cancer patients with pulmonary complications undergoing noncardiac major surgeries.
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Coached practice using ERCP mechanical simulator improves trainees ERCP performance: a randomized controlled trial.
Endoscopy
PUBLISHED: 07-29-2013
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Preliminary data suggested that simulation practice using an endoscopic retrograde cholangiopancreatography (ERCP) mechanical simulator (EMS) improved trainees skill. The aims of the current study were to confirm the impact of coached EMS practice at the beginning of ERCP training and to investigate whether subsequent uncoached EMS practice provides additional benefit.
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Fungal Cellulase/Xylanase Production and Corresponding Hydrolysis Using Pretreated Corn Stover as Substrates.
Appl. Biochem. Biotechnol.
PUBLISHED: 07-16-2013
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Three pretreated corn stover (ammonia fiber expansion, dilute acid, and dilute alkali) were used as carbon source to culture Trichoderma reesei Rut C-30 for cellulase and xylanase production. The results indicated that the cultures on ammonia fiber expansion and alkali pretreated corn stover had better enzyme production than the acid pretreated ones. The consequent enzymatic hydrolysis was performed applying fungal enzymes on pretreated corn stover samples. Tukeys statistical comparisons exhibited that there were significant differences on enzymatic hydrolysis among different combination of fungal enzymes and pretreated corn stover. The higher sugar yields were achieved by the enzymatic hydrolysis of dilute alkali pretreated corn stover.
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Epileptic discharges specifically affect intrinsic connectivity networks during absence seizures.
J. Neurol. Sci.
PUBLISHED: 07-13-2013
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Intrinsic connectivity network (ICN) technique provides a feasible way for evaluating cognitive impairments in epilepsy. This EEG-fMRI study aims to comprehensively assess the alterations of ICNs affected by generalized spike-and-wave discharge (GSWD) during absence seizure (AS). Twelve fMRI sessions with GSWD, and individually paired non-GSWD sessions were acquired from 16 patients with AS. Ten ICNs corresponding to seizure origination and cognitive processes were extracted using independent component analysis. Intra- and inter-network connectivity alterations of the ICNs were observed through comparisons between GSWD and non-GSWD sessions. Sequential correlation analysis between GSWD and the ICN time courses addressed the immediate effects of GSWD on ICNs during AS. GSWD-related increase of intra-network connectivity was found only in the thalamus, and extensive decreases were found in the ICNs corresponding to higher-order cognitive processes including the default-mode network, dorsal attention network, central executive network and salience network. The perceptive networks and motor network were less affected by GSWD. Sequential correlation analysis further demonstrated different responses of the ICNs to GSWD. In addition to GSWD-related functional excitation in the thalamus and functional suspension in the default-mode network, this study revealed extensive inhibitions in the other ICNs corresponding to higher-order cognitive processes, and spared perceptive and motor processes in AS. GSWD elevated synchronization of brain network activity and sequentially affected the ICNs.
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A microfluidic cell culture array with various oxygen tensions.
Lab Chip
PUBLISHED: 06-20-2013
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Oxygen tension plays an important role in regulating various cellular functions in both normal physiology and disease states. Therefore, drug testing using conventional in vitro cell models under normoxia often possesses limited prediction capability. A traditional method of setting an oxygen tension in a liquid medium is by saturating it with a gas mixture at the desired level of oxygen, which requires bulky gas cylinders, sophisticated control, and tedious interconnections. Moreover, only a single oxygen tension can be tested at the same time. In this paper, we develop a microfluidic cell culture array platform capable of performing cell culture and drug testing under various oxygen tensions simultaneously. The device is fabricated using an elastomeric material, polydimethylsiloxane (PDMS) and the well-developed multi-layer soft lithography (MSL) technique. The prototype device has 4 × 4 wells, arranged in the same dimensions as a conventional 96-well plate, for cell culture. The oxygen tensions are controlled by spatially confined oxygen scavenging chemical reactions underneath the wells using microfluidics. The platform takes advantage of microfluidic phenomena while exhibiting the combinatorial diversities achieved by microarrays. Importantly, the platform is compatible with existing cell incubators and high-throughput instruments (liquid handling systems and plate readers) for cost-effective setup and straightforward operation. Utilizing the developed platform, we successfully perform drug testing using an anti-cancer drug, triapazamine (TPZ), on adenocarcinomic human alveolar basal epithelial cell line (A549) under three oxygen tensions ranging from 1.4% to normoxia. The developed platform is promising to provide a more meaningful in vitro cell model for various biomedical applications while maintaining desired high throughput capabilities.
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Impaired self-referential processing in mesial temporal lobe epilepsy: a functional MRI study.
Neurosci. Lett.
PUBLISHED: 05-16-2013
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Mesial temporal lobe epilepsy (mTLE) presents typical symptoms of cognitive impairments and mental disorders, which is presumed to be related to impairment of self-referential processing. This study aims to investigate the alterations of self-reference in mTLE using functional magnetic resonance imaging (fMRI). Fifty patients with unilateral mTLE (26 left- and 24 right-sided mTLE) were recruited in the present study. Traditional task paradigm of internally-cued condition vs. externally-cued condition was employed to induce self-referential activation. FMRI activation in each group of patients was compared with that of 30 healthy controls. Moreover, fMRI responses in the dorsal mesial prefrontal cortex were specifically addressed by correlating with behavioral data of reaction times and clinical data of epilepsy duration, respectively. Compared with the healthy controls, both two groups of patients showed decreased behavioral performance (reaction times) and decreased fMRI activation of self-reference in the anterior and posterior cortical midline structures. Moreover, fMRI activation was found to be negatively correlated with behavioral performance and epilepsy duration. The present findings implicate functional impairment of self-reference caused by epilepsy in mTLE. This study provided imaging evidence for functional impairments of self-referential processing and brain default-mode function in mTLE.
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Recovering directed networks in neuroimaging datasets using partially conditioned Granger causality.
Brain Connect
PUBLISHED: 05-15-2013
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Recovering directed pathways of information transfer between brain areas is an important issue in neuroscience and helps to shed light on the brain function in several physiological and cognitive states. Granger causality (GC) analysis is a valuable tool to detect directed dynamical connectivity, and it is being increasingly used. Unfortunately, this approach encounters some limitations in particularly when applied to neuroimaging datasets, often consisting in short and noisy data and for which redundancy plays an important role. In this article, we address one of these limitations, namely, the computational and conceptual problems arising when conditional GC, necessary to disambiguate direct and mediated influences, is used on short and noisy datasets of many variables, as it is typically the case in some electroencephalography (EEG) protocols and in functional magnetic resonance imaging (fMRI). We show that considering GC in the framework of information theory we can limit the conditioning to a limited number of variables chosen as the most informative, obtaining more stable and reliable results both in EEG and fMRI data.
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[Effects of Baidanhuang lavage fluid nasal irrigation on the postoperative patients with chronic rhinosinusitis with nasal polyps].
Zhongguo Zhong Xi Yi Jie He Za Zhi
PUBLISHED: 05-08-2013
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To observe the clinical efficacy of Baidanhuang lavage fluid nasal irrigation (BLFNI) on postoperative patients with chronic sinusitis with nasal polyps (CRwNP).
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Phthalic Acid chemical probes synthesized for protein-protein interaction analysis.
Int J Mol Sci
PUBLISHED: 05-02-2013
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Plasticizers are additives that are used to increase the flexibility of plastic during manufacturing. However, in injection molding processes, plasticizers cannot be generated with monomers because they can peel off from the plastics into the surrounding environment, water, or food, or become attached to skin. Among the various plasticizers that are used, 1,2-benzenedicarboxylic acid (phthalic acid) is a typical precursor to generate phthalates. In addition, phthalic acid is a metabolite of diethylhexyl phthalate (DEHP). According to Gene_Ontology gene/protein database, phthalates can cause genital diseases, cardiotoxicity, hepatotoxicity, nephrotoxicity, etc. In this study, a silanized linker (3-aminopropyl triethoxyslane, APTES) was deposited on silicon dioxides (SiO2) particles and phthalate chemical probes were manufactured from phthalic acid and APTES-SiO2. These probes could be used for detecting proteins that targeted phthalic acid and for protein-protein interactions. The phthalic acid chemical probes we produced were incubated with epithelioid cell lysates of normal rat kidney (NRK-52E cells) to detect the interactions between phthalic acid and NRK-52E extracted proteins. These chemical probes interacted with a number of chaperones such as protein disulfide-isomerase A6, heat shock proteins, and Serpin H1. Ingenuity Pathways Analysis (IPA) software showed that these chemical probes were a practical technique for protein-protein interaction analysis.
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Effects of multiwalled carbon nanotubes functionalization on the morphology and mechanical and thermal properties of carbon fiber/vinyl ester composites.
ACS Appl Mater Interfaces
PUBLISHED: 04-29-2013
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Multiwalled carbon nanotube (MWCNT)/carbon fiber (CF)/vinyl ester (VE) laminate composites have been fabricated in this study. Pristine MWCNTs were treated with acid solution, which formed numerous oxygen-containing functional groups onto their surface, resulting in COOH-MWCNTs. Thereafter, acrylic functional groups were grafted onto the COOH-MWCNTs to generate acryl-MWCNTs. Three types of MWCNTs (pristine MWCNTs, COOH-MWCNTs, and acryl-MWCNTs) were used to reinforce the CF/VE-based composites. The dispersion of MWCNTs in the VE matrix and the interfacial interaction between MWCNTs and the VE matrix were investigated. Thereafter, the individual reinforcement efficiencies of these MWCNTs are compared. The flexural strength of the MWCNT/CF/VE composite with 1.0 phr acryl-MWCNTs content is 29.8% greater than that of neat CF/VE composites, and the flexural modulus of the MWCNT/CF/VE composite is 9.9% higher than that of neat CF/VE composites. Compared with neat CF/VE composites, 1.0 phr acryl-MWCNT/CF/VE composites exhibit an approximately 19.9 °C increase in glass transition temperature (Tg). The coefficients of thermal expansion significantly decreased from 47.2 ppm/°C of the neat CF/VE composites to 35.6 ppm/°C of the acryl-MWCNTs/CF/VE composites with 1 phr acryl-MWCNT content. This study provides a method for developing acryl-MWCNT/CF/VE composites with good dispersion of MWCNTs in VE matrix and strong interfacial interaction between the MWCNTs and VE matrix for enhancing the stress transfer from VE matrix to CF reinforcement.
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[Treatment of nasopharyngeal carcinoma in children].
Zhongguo Dang Dai Er Ke Za Zhi
PUBLISHED: 04-24-2013
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To evaluate the clinical efficacy of the ARAR0331 protocol for treatment of childhood nasopharyngeal carcinoma.
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Human induced pluripotent stem cell-derived neural stem cells survive, migrate, differentiate, and improve neurological function in a rat model of middle cerebral artery occlusion.
Stem Cell Res Ther
PUBLISHED: 04-01-2013
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INTRODUCTION: Stroke is a major cause of permanent neurological damage, with few effective treatments available to restore lost function. Induced pluripotent stem cells (iPSCs) have the potential to generate all cell types in vitro and can be generated from a stroke patient. Therefore, iPSCs are attractive donor sources of genetically identical "patient-specific" cells to hold promise in therapy for stroke. In the present study, we established a four-stage culture system using serum-free medium and retinoic acid (RA) to differentiate iPSCs into neural stem cells (NSCs) effectively and stably. Our hypothesis was that iPSC-derived NSCs would survive, migrate, and differentiate in vivo, and improve neurological function after transplantation into the brain of rats with ischemic stroke. METHODS: Human iPSCs (iPS-S-01) and human ESCs (HuES17) were used to differentiate into NSCs using our four-stage culture system. iPSCs and differentiated NSCs were characterized by immunocytochemistry staining and RT-PCR analysis. After establishment of focal cerebral ischemia with occlusion of the middle cerebral artery (MCA) and cell transplantation, animals were euthanized at 1 week and 2 weeks to analyze survival, migration and differentiation of implanted cells in brain tissue. Animal behavior was evaluated via rope grabbing, beam walking and Morris water maze tests. RESULTS: iPSCs were efficiently induced into NSCs using a newly established four-stage induction system in vitro. iPSCs expressed pluripotency-associated genes Oct4, Sox2, and Nanog before NSC differentiation. And iPSC-derived NSCs spontaneously differentiated into neurons and astrocytes which highly express beta-tubulin and glial fibrillary acidic protein (GFAP) respectively. Upon transplantation into the striatum, CM-DiI labeled iPSC-derived NSCs were found to migrate into the ischemia area at 1 week and 2 weeks, and animal function recovery was significantly improved in comparison with control groups at 3 weeks. CONCLUSIONS: The four-stage induction system is stable and effective to culture, differentiate and induce iPSCs to NSCs using serum-free medium combined with retinoic acid (RA). Implanted iPSC-derived NSCs were able to survive, and migrate into the ischemic brain area to differentiate into mature neural cells, and seem to have potential to restore lost neurological function from damage due to stroke in a rat model.
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Relationship between large-scale functional and structural covariance networks in idiopathic generalized epilepsy.
Brain Connect
PUBLISHED: 03-21-2013
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The human brain can be modeled as a network, whose structure can be revealed by either anatomical or functional connectivity analyses. Little is known, so far, about the topological features of the large-scale interregional functional covariance network (FCN) in the brain. Further, the relationship between the FCN and the structural covariance network (SCN) has not been characterized yet, in the intact as well as in the diseased brain. Here, we studied 59 patients with idiopathic generalized epilepsy characterized by tonic-clonic seizures and 59 healthy controls. We estimated the FCN and the SCN by measuring amplitude of low-frequency fluctuations (ALFF) and gray matter volume (GMV), respectively, and then we conducted graph theoretical analyses. Our ALFF-based FCN and GMV-based results revealed that the normal human brain is characterized by specific topological properties such as small worldness and highly-connected hub regions. The patients had an altered overall topology compared to the controls, suggesting that epilepsy is primarily a disorder of the cerebral network organization. Further, the patients had altered nodal characteristics in the subcortical and medial temporal regions and default-mode regions, for both the FCN and SCN. Importantly, the correspondence between the FCN and SCN was significantly larger in patients than in the controls. These results support the hypothesis that the SCN reflects shared long-term trophic mechanisms within functionally synchronous systems. They can also provide crucial information for understanding the interactions between the whole-brain network organization and pathology in generalized tonic-clonic seizures.
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Management of acute gastric varices bleeding.
J Chin Med Assoc
PUBLISHED: 03-20-2013
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Gastroesophageal varices bleeding is a major complication in patients with cirrhosis. Gastric varices (GVs) occur in approximately 20% of patients with portal hypertension. However, GV bleeding develops in only 25% of patients with GV and requires more transfusion and has higher mortality than esophageal variceal (EV) bleeding. The best strategy for managing acute GV bleeding is similar to that of acute EV bleeding, which involves airway protection, hemodynamic stabilization, and intensive care. Blood transfusion should be cautiously administered in order to avoid rebleeding. Vasoactive agents such as terlipressin or somatostatin should be used when GV bleeding is suspected. Routine use of prophylactic antibiotics reduces bacterial infection and lowers rebleeding rates. By administering endoscopic cyanoacrylate injection, the initial hemostasis rate achieved is at least 90% in most cases; the average mortality rate of GV bleeding is approximately 10-30% and the rebleeding rate is between 22% and 37%. Although endoscopic injection of cyanoacrylate is superior to sclerotherapy and band ligation, and has remained the treatment of choice for treating acute GV bleeding, the outcome of this treatment is still unsatisfactory. New treatment options, such as thrombin injection, transjugular intrahepatic portosystemic shunts, or balloon-occluded retrograde transvenous obliteration, have shown promising results for acute GV bleeding. However, randomized controlled trials are needed to compare the efficacy of these therapies with cyanoacrylate.
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Coadministration of glycogen-synthase kinase 3 inhibitor with morphine attenuates chronic morphine-induced analgesic tolerance and withdrawal syndrome.
J Chin Med Assoc
PUBLISHED: 03-19-2013
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Glycogen-synthase kinase 3 (GSK3) is involved in many signaling pathways and is associated with a host of high-profile pathophysiological states. However, its role in morphine tolerance, especially naloxone-precipitated withdrawal syndrome, has not been well investigated. The present study was undertaken to study the role of GSK3 in chronic morphine exposure.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.