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Find video protocols related to scientific articles indexed in Pubmed.
Ultrasensitive electrochemical biosensing for DNA using quantum dots combined with restriction endonuclease.
Analyst
PUBLISHED: 11-20-2014
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A universal and sensitive electrochemical biosensing platform for the detection and identification of DNA using CdSe quantum dots (CdSe QDs) as signal markers was designed. The detection mechanism was based on the specific recognition of MspI endonuclease combined with the signal amplification of gold nanoparticles (AuNPs). MspI endonuclease could recognize its specific sequence in the double-strand DNA (dsDNA) and cleave the dsDNA fragments linked with CdSe QDs from the electrode. The remaining attached CdSe QDs can be easily read out by square-wave voltammetry using an electrodeposited bismuth (Bi) film-modified glass carbon electrode. The concentrations of target DNA could be simultaneously detected by the signal of metal markers. Using mycobacterium tuberculosis (Mtb) DNA as a model, under the optimal conditions, the proposed biosensor could detect Mtb DNA down to 8.7 × 10(-15) M with a linear range of 5 orders of magnitude (from 1.0 × 10(-14) to 1.0 × 10(-9) M) and discriminate mismatched DNA with high selectivity. This strategy presented a universal and convenient biosensing platform for DNA assay, and its satisfactory performances make it a potential candidate for the early diagnosis of gene-related diseases.
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Osteogenic Commitment of Mesenchymal Stem Cells in Apatite Nanorods-Aligned Ceramics.
ACS Appl Mater Interfaces
PUBLISHED: 11-19-2014
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It is significant to process the clinically-used biomaterials into a scaffold with specific nanotopographies which can act as physical cues to regulate the osteogenic commitment of mesenchymal stem cells. In this study, hydroxyapatite (HAP) was considered as the processed objective and a facile, hydrothermal method was developed to grow the vertically-oriented HAP nanorods in porous HAP ceramics. Experiments demonstrated that the formation of the HAP nanorods in porous ceramics was decided by a novel epitaxial growth mechanism and length of nanorods could be well controlled by the growth time. Cell experiments demonstrated that such novel stereo-topographical cues could regulate bone marrow mesenchymal stem cells to differentiate into the osteogenic lineage, thereby displaying that the porous ceramics with the HAP nanorods-aligned stereo-topographies have a good prospect for applications in regen-erative medicine of hard tissues.
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Inflammatory Markers of the Systemic Capillary Leak Syndrome (Clarkson Disease).
J Clin Cell Immunol
PUBLISHED: 11-19-2014
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The Systemic Capillary Leak Syndrome (SCLS) is a rare and potentially fatal disorder resembling systemic anaphylaxis that is characterized by transient episodes of hypotensive shock and peripheral edema. The pathogenesis of SCLS is unknown, and triggers for attacks are apparent only in a minority of patients. We introduce a clinical algorithm for the diagnosis of SCLS, and we investigated potential serum biomarkers of acute SCLS episodes.
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Principal-vector-directed fringe-tracking technique.
Appl Opt
PUBLISHED: 11-18-2014
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Fringe tracking is one of the most straightforward techniques for analyzing a single fringe pattern. This work presents a principal-vector-directed fringe-tracking technique. It uses Gaussian derivatives for estimating fringe gradients and uses hysteresis thresholding for segmenting singular points, thus improving the principal component analysis method. Using it allows us to estimate the principal vectors of fringes from a pattern with high noise. The fringe-tracking procedure is directed by these principal vectors, so that erroneous results induced by noise and other error-inducing factors are avoided. At the same time, the singular point regions of the fringe pattern are identified automatically. Using them allows us to determine paths through which the "seed" point for each fringe skeleton is easy to find, thus alleviating the computational burden in processing the fringe pattern. The results of a numerical simulation and experiment demonstrate this method to be valid.
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Plasmon-induced transparency in a single multimode stub resonator.
Opt Express
PUBLISHED: 11-18-2014
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We investigate electromagnetically induced transparency (EIT)-like effect in a metal-dielectric-metal (MDM) waveguide coupled to a single multimode stub resonator. Adjusting the geometrical parameters of the stub resonator, we can realize single or double plasmon-induced transparency (PIT) windows in the plasmonic structure. Moreover, the consistency between analytical results and finite difference time domain (FDTD) simulations reveals that the PIT results from the destructive interference between resonance modes in the stub resonator. Compared with previous EIT-like scheme based on MDM waveguide, the plasmonic system takes the advantages of easy fabrication and compactness. The results may open up avenues for the control of light in highly integrated optical circuits.
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Theoretical analysis and applications on nano-block loaded rectangular ring.
J Opt Soc Am A Opt Image Sci Vis
PUBLISHED: 11-18-2014
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We propose compact and switchable optical filters based on nano-block loaded rectangular rings, and investigate the selection property numerically and theoretically. A simple and convenient phase model is established for the theoretical analysis. The dependent factors, such as the number, size, and positions of the loaded blocks, are discussed in detail. It is found that a longer wavelength can be obtained without increasing the device dimension, and the selected wave is more sensitive to the length of the loaded blocks. The loading positions play key roles in the realization of separating the second-order modes. Finally, applications of this proposed structure are discussed simply. We find that the loaded filter device provides a more compact size than the unloaded one for the same properties, and a tunable plasmon induced transparency based switch effect is also achieved. These findings suggest potential applications in compact filters, tunable slow light devices, and sensor fields.
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Combined theoretical analysis for plasmon-induced transparency in waveguide systems.
Opt Lett
PUBLISHED: 11-01-2014
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We propose a novel combination of a radiation field model and the transfer matrix method (TMM) to demonstrate plasmon-induced transparency (PIT) in bright-dark mode waveguide structures. This radiation field model is more effective and convenient for describing direct coupling in bright-dark mode resonators, and is promoted to describe transmission spectra and scattering parameters quantitatively in infinite element structures by combining it with the TMM. We verify the correctness of this novel combined method through numerical simulation of the metal-dielectric-metal (MDM) waveguide side-coupled with typical bright-dark mode, H-shaped resonators; the large group index can be achieved in these periodic H-shaped resonators. These results may provide a guideline for the control of light in highly integrated optical circuits.
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Effects of fetal microwave radiation exposure on offspring behavior in mice.
J. Radiat. Res.
PUBLISHED: 11-01-2014
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The recent rapid development of electronic communication techniques is resulting in a marked increase in exposure of humans to electromagnetic fields (EMFs). This has raised public concerns about the health hazards of long-term environmental EMF exposure for fetuses and children. Some studies have suggested EMF exposure in children could induce nervous system disorders. However, gender-dependent effects of microwave radiation exposure on cognitive dysfunction have not previously been reported. Here we investigated whether in utero exposure to 9.417-GHz microwave throughout gestation (Days 3.5-18) affected behavior, using the open field test (OFT), elevated-plus maze (EPM), tail suspension test (TST), forced swimming test (FST) and Morris water maze (MWM). We found that mice showed less movement in the center of an open field (using the OFT) and in an open arm (using the EPM) after in utero exposure to 9.417-GHz radiation, which suggested that the mice had increased anxiety-related behavior. Mice demonstrated reduced immobility in TST and FST after in utero exposure to 9.417-GHz radiation, which suggested that the mice had decreased depression-related behavior. From the MWM test, we observed that male offspring demonstrated decreased learning and memory, while females were not affected in learning and memory, which suggested that microwaves had gender-dependent effects. In summary, we have provided the first experimental evidence of microwaves inducing gender-dependent effects.
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MicroRNA-638 inhibits cell proliferation, invasion and regulates cell cycle by targeting tetraspanin 1 in human colorectal carcinoma.
Oncotarget
PUBLISHED: 10-11-2014
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The expression of miR-638 was found downregulated in colorectal carcinoma (CRC) in our previous study. However, the role of miR-638 in CRC remains unknown. The aim of this study was to determine the function and mechanism of miR-638 in CRC. Here, we verified that miR-638 was frequently downregulated in CRC tissues compared with corresponding noncancerous tissues (NCTs) in an expanded CRC cohort, and survival analysis showed that the downregulation of miR-638 in CRC was associated with poor prognoses. The ectopic expression of miR-638 inhibited CRC cell proliferation, invasion and arrest the cell cycle in G1 phase, whereas the repression of miR-638 significantly promoted CRC cell growth, invasion and cell cycle G1/S transition. Subsequent mechanism analyses revealed that miR-638 inhibited CRC cell growth, invasion and cell cycle progression by targeting TSPAN1. TSPAN1 protein levels were upregulated in CRC samples and were inversely correlated with miR-638 levels. More importantly, high TSPAN1 expression levels in CRC tissues predicted poor overall survival, and appears to be an independent prognostic factor for CRC survival. Furthermore, CpG island methylation analyses revealed that the miR-638 promoter was hypermethylated in CRC and that attenuating promoter methylation was sufficient to restore miR-638 expression in CRC cells. Taken together, our current data demonstrate that miR-638 functions as a tumor suppressor in human CRC by inhibiting TSPAN1, and that TSPAN1 is a potential prognostic factor for CRC.
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A carbon nanotube/quantum dot based photoelectrochemical biosensing platform for the direct detection of microRNAs.
Chem. Commun. (Camb.)
PUBLISHED: 09-17-2014
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A versatile photoelectrochemical biosensing platform was developed based on DNA-CdS quantum dots (QDs) sensitized single-walled carbon nanotubes (SWCNTs)-COOH. Combining with cyclic enzymatic amplification, a convenient, sensitive and specific biosensor for the direct detection of microRNAs (miRNAs) was designed, which provided a novel approach for analysis of miRNAs.
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[The inhibitory effects of dexamethasone on cisplatin induced apoptosis of human lung adenocarcinoma cell SPC-A1 and its molecular mechanism].
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi
PUBLISHED: 09-16-2014
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The aim of this study is to investigate the apoptotic inhibition and its molecular mechanism of dexamethasone (DEX) acting on cisplatin (CDDP)-induced apoptosis of human lung adenocarcinoma cell SPC-A1; SPC-A1 cells were pre-cultured in vitro for 24 hours with DEX in different concentrations and then CDDP was added in different concentrations for culturing for further 48 hours. The survival rates of the cells were determined by MTT. The expression of serum/glucocorticoid-induced kinase (SGK-1) and mitogen-activated protein kinase phosphatase-1 (MKP-1) in SPC-A1 cells after being cultured by 1 micromol/l DEX at different time was detected by semi-quantitative RT-PCR technology. The expression of glucocorticoid receptor (GR) in SPC-A1 cells was measured by immunohistochemistry (IHC) with biotin-labeled anti-GR. The results of MTT showed that SPC-A1 cells had resistance to CDDP-induced apoptosis with pre-cultured DEX and the resistance intensity presented DEX concentration-dependent. The expressing quantity of SGK-1 in SPC-A1 cells stimulated by DEX could be elevated and increased with intention of time, but the express of MKP-1 was not detected. Up-regulated expression of GR in SPC-A1 cells stimulated by DEX was detected by IHC. The number of cells expressing GR in SPC-A1 cells was significantly higher than that in the control group. The results showed that DEX inhibited apoptosis of SPC-A1 cells induced by CDDP. The possible molecular mechanism is that elevated expression of GR induced by DEX up-regulates the expression of SGK-1 which locates at the downstream of anti-apoptosis pathway. The apoptosis resistance of SPC-A1 cells may account for all above the factors.
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lncRNA expression signatures in periodontitis revealed by microarray: The potential role of lncRNAs in periodontitis pathogenesis.
J. Cell. Biochem.
PUBLISHED: 09-14-2014
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Periodontitis, a common chronic inflammatory disease of the periodontium, is caused by dental plaque formation induced by microorganisms. Recent studies have demonstrated that lncRNAs play a critical role in the regulation of gene expression and in the pathogenesis of diseases. To demonstrate that periodontitis is associated with lncRNAs, microarray analysis was used to detect differently expressed lncRNAs in chronic periodontitis and adjacent normal tissues. The results of some differently expressed lncRNAs were further confirmed using real-time PCR. A total of 8925 differentially expressed lncRNAs were detected, including 4313 upregulated lncRNAs and 4612 downregulated lncRNAs. Further lncRNA subgroup analysis showed there were 589 enhancer-like lncRNAs, 238 homeobox (HOX) cluster lncRNAs, and 1218 Rinn's lincRNAs, of which 656 lincRNAs were upregulated and 562 lincRNAs were downregulated. Therefore, we confirmed that lncRNAs were differently expressed in chronic periodontitis tissues compared with adjacent normal tissues, indicating that lncRNAs may exert partial or key roles in periodontitis pathogenesis and development. Taken together, this study may provide potential targets for future treatment of periodontitis and novel diagnostic biomarkers for periodontitis. This article is protected by copyright. All rights reserved.
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Screening a Strain of Aspergillus niger and Optimization of Fermentation Conditions for Degradation of Aflatoxin B1.
Toxins (Basel)
PUBLISHED: 09-13-2014
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Aflatoxin B1, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B1 after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B1 after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B1 degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B1 was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B1 degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B1 degradation by the supernatant were examined. Results indicated that aflatoxin B1 degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.
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Photoelectrochemical biosensor using enzyme-catalyzed in situ propagation of CdS quantum dots on graphene oxide.
ACS Appl Mater Interfaces
PUBLISHED: 09-08-2014
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An innovative photoelectrochemical (PEC) biosensor platform was designed based on the in situ generation of CdS quantum dots (QDs) on graphene oxide (GO) using an enzymatic reaction. Horseradish peroxidase catalyzed the reduction of sodium thiosulfate with hydrogen peroxide to generate H2S, which reacted with Cd(2+) to form CdS QDs. CdS QDs could be photoexcited to generate an elevated photocurrent as a readout signal. This strategy offered a "green" alternative to inconvenient presynthesis procedures for the fabrication of semiconducting nanoparticles. The nanomaterials and assembly procedures were characterized by microscopy and spectroscopy techniques. Combined with immune recognition and on the basis of the PEC activity of CdS QDs on GO, the strategy was successfully applied to a PEC assay to detect carcinoembryonic antigen and displayed a wide linear range from 2.5 ng mL(-1) to 50 ?g mL(-1) and a detection limit of 0.72 ng mL(-1) at a signal-to-noise ratio of 3. The PEC biosensor showed satisfactory performance for clinical sample detection and was convenient for determining high concentrations of solute without dilution. This effort offers a new opportunity for the development of numerous rapid and convenient analytical techniques using the PEC method that may be applied in the design and preparation of various solar-energy-driven applications.
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Electrocatalytic activity of Pt subnano/nanoclusters stabilized by pristine graphene nanosheets.
Phys Chem Chem Phys
PUBLISHED: 09-05-2014
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Downsizing the Pt particle to the atomic level in the electro-catalysts is highly desirable to enhance its utilization efficiency in fuel cells. In this study, Pt subnano/nanoclusters were stabilized by the pristine graphene nanosheets (GNSs) derived from chemical vapor deposition and the resulting Pt/GNS hybrids were examined as catalysts for electro-oxidation of alcohols (methanol, ethanol, ethylene glycol and glycerol). In spite of the strong hydrophobic surface, the GNS was proved to be a promising catalyst support because the edges and defects in the GNS could effectively anchor and stabilize the Pt subnano/nanoclusters. The Pt/GNS catalyst showed an extremely high electrochemical active surface area and superior catalytic activity for alcohol oxidation compared with the commercial Pt/carbon black catalyst. The enhanced catalytic performance was attributed to the presence of the discrete Pt subnano/nanoclusters as well as the modulation of the electronic properties of Pt nanoparticles through the chemical interaction of Pt atoms with the edges and defects of the GNS support.
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Essential role of the zinc finger transcription factor casz1 for Mammalian cardiac morphogenesis and development.
J. Biol. Chem.
PUBLISHED: 09-04-2014
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Chromosome 1p36 deletion syndrome is one of the most common terminal deletions observed in humans and is related to congenital heart disease (CHD). However, the 1p36 genes that contribute to heart disease have not been clearly delineated. Human CASZ1 gene localizes to 1p36 and encodes a zinc finger transcription factor. Casz1 is required for Xenopus heart ventral midline progenitor cell differentiation. Whether Casz1 plays a role during mammalian heart development is unknown. Our aim is to determine 1p36 gene CASZ1 function at regulating heart development in mammals. We generated a Casz1 knock-out mouse using Casz1-trapped embryonic stem cells. Casz1 deletion in mice resulted in abnormal heart development including hypoplasia of myocardium, ventricular septal defect, and disorganized morphology. Hypoplasia of myocardium was caused by decreased cardiomyocyte proliferation. Comparative genome-wide RNA transcriptome analysis of Casz1 depleted embryonic hearts identifies abnormal expression of genes that are critical for muscular system development and function, such as muscle contraction genes TNNI2, TNNT1, and CKM; contractile fiber gene ACTA1; and cardiac arrhythmia associated ion channel coding genes ABCC9 and CACNA1D. The transcriptional regulation of some of these genes by Casz1 was also found in cellular models. Our results showed that loss of Casz1 during mouse development led to heart defect including cardiac noncompaction and ventricular septal defect, which phenocopies 1p36 deletion syndrome related CHD. This suggests that CASZ1 is a novel 1p36 CHD gene and that the abnormal expression of cardiac morphogenesis and contraction genes induced by loss of Casz1 contributes to the heart defect.
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High dose intravenous immunoglobulin therapy of the Systemic Capillary Leak Syndrome (Clarkson disease).
Am. J. Med.
PUBLISHED: 09-02-2014
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The Systemic Capillary Leak Syndrome is a highly rare disorder of unknown etiology. The disease is characterized by episodes of transient vascular collapse, which leads to hypotensive shock and anasarca. Previous treatment of this potentially devastating condition has been largely ineffective. We evaluated IVIG prophylactic therapy in a cohort of 29 patients with Systemic Capillary Leak Syndrome in a longitudinal follow up study.
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Transformation of the education of health professionals in China: progress and challenges.
Lancet
PUBLISHED: 09-02-2014
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In this Review we examine the progress and challenges of China's ambitious 1998 reform of the world's largest health professional educational system. The reforms merged training institutions into universities and greatly expanded enrolment of health professionals. Positive achievements include an increase in the number of graduates to address human resources shortages, acceleration of production of diploma nurses to correct skill-mix imbalance, and priority for general practitioner training, especially of rural primary care workers. These developments have been accompanied by concerns: rapid expansion of the number of students without commensurate faculty strengthening, worries about dilution effect on quality, outdated curricular content, and ethical professionalism challenged by narrow technical training and growing admissions of students who did not express medicine as their first career choice. In this Review we underscore the importance of rebalance of the roles of health sciences institutions and government in educational policies and implementation. The imperative for reform is shown by a looming crisis of violence against health workers hypothesised as a result of many factors including deficient educational preparation and harmful profit-driven clinical practices.
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BMP9 regulates cross-talk between breast cancer cells and bone marrow-derived mesenchymal stem cells.
Cell Oncol (Dordr)
PUBLISHED: 09-01-2014
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Breast cancer cells frequently metastasize to distant organs, including bone. Interactions between breast cancer cells and the bone microenvironment are known to enhance tumor growth and osteolytic damage. Here we investigated whether BMP9 (a secretary protein) may change the bone microenvironment and, by doing so, regulate the cross-talk between breast cancer cells and bone marrow-derived mesenchymal stem cells.
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Synthesis of ultrafine Pt nanoparticles stabilized by pristine graphene nanosheets for electro-oxidation of methanol.
ACS Appl Mater Interfaces
PUBLISHED: 08-28-2014
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In this study, the pristine graphene nanosheets (GNS) derived from chemical vapor deposition process were employed as catalyst support. In spite of the extremely hydrophobic GNS surface, ultrafine Pt nanoparticles (NPs) were successfully assembled on the GNS through a surfactant-free solution process. The evolution of Pt NPs in the GNS support was studied using transmission electron microscopy. It was found that the high-energy surface sites in the GNS, such as edges and defects, played a critical role on anchoring and stabilizing Pt nuclei, leading to the formation of Pt NPs on the GNS support. The concentration of the Pt precursor, i.e., H2PtCl6 solution had significant effects on the morphology of Pt/GNS hybrids. The resulting Pt/GNS hybrids were examined as catalysts for methanol electro-oxidation. It was indicated that the electrochemical active surface area and catalytic activity of the Pt/GNS hybrids were highly dependent on Pt loadings. The superior activity of the catalysts with low Pt loadings was attributed to the presence of Pt subnanoclusters as well as the strong chemical interaction of Pt NPs with the GNS support.
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mTORC2 regulates mechanically induced cytoskeletal reorganization and lineage selection in marrow-derived mesenchymal stem cells.
J. Bone Miner. Res.
PUBLISHED: 08-20-2014
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The cell cytoskeleton interprets and responds to physical cues from the microenvironment. Applying mechanical force to mesenchymal stem cells induces formation of a stiffer cytoskeleton, which biases against adipogenic differentiation and toward osteoblastogenesis. mTORC2, the mTOR complex defined by its binding partner rictor, is implicated in resting cytoskeletal architecture and is activated by mechanical force. We asked if mTORC2 played a role in mechanical adaptation of the cytoskeleton. We found that during bi-axial strain-induced cytoskeletal restructuring, mTORC2 and Akt colocalize with newly assembled focal adhesions (FA). Disrupting the function of mTORC2, or that of its downstream substrate Akt, prevented mechanically induced F-actin stress fiber development. mTORC2 becomes associated with vinculin during strain, and knockdown of vinculin prevents mTORC2 activation. In contrast, mTORC2 is not recruited to the FA complex during its activation by insulin, nor does insulin alter cytoskeletal structure. Further, when rictor was knocked down, the ability of mesenchymal stem cells (MSC) to enter the osteoblastic lineage was reduced, and when cultured in adipogenic medium, rictor-deficient MSC showed accelerated adipogenesis. This indicated that cytoskeletal remodeling promotes osteogenesis over adipogenesis. In sum, our data show that mTORC2 is involved in stem cell responses to biophysical stimuli, regulating both signaling and cytoskeletal reorganization. As such, mechanical activation of mTORC2 signaling participates in mesenchymal stem cell lineage selection, preventing adipogenesis by preserving ?-catenin and stimulating osteogenesis by generating a stiffer cytoskeleton.
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Aortic dissection presenting an acute onset of neuroradicular syndrome complicated by coeliac and superior mesenteric artery embolism.
Emerg Med Australas
PUBLISHED: 08-19-2014
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Aortic dissection is a catastrophic medical emergency with complex and changeable clinical presentations. We report a case of aortic dissection complicated by coeliac and superior mesenteric artery embolism, which is hardly been reported till date.
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An intensity ratio of interlocking loops determines circadian period length.
Nucleic Acids Res.
PUBLISHED: 08-13-2014
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Circadian clocks allow organisms to orchestrate the daily rhythms in physiology and behaviors, and disruption of circadian rhythmicity can profoundly affect fitness. The mammalian circadian oscillator consists of a negative primary feedback loop and is associated with some 'auxiliary' loops. This raises the questions of how these interlocking loops coordinate to regulate the period and maintain its robustness. Here, we focused on the REV-ERB?/Cry1 auxiliary loop, consisting of Rev-Erb?/ROR-binding elements (RORE) mediated Cry1 transcription, coordinates with the negative primary feedback loop to modulate the mammalian circadian period. The silicon simulation revealed an unexpected rule: the intensity ratio of the primary loop to the auxiliary loop is inversely related to the period length, even when post-translational feedback is fixed. Then we measured the mRNA levels from two loops in 10-mutant mice and observed the similar monotonic relationship. Additionally, our simulation and the experimental results in human osteosarcoma cells suggest that a coupling effect between the numerator and denominator of this intensity ratio ensures the robustness of circadian period and, therefore, provides an efficient means of correcting circadian disorders. This ratio rule highlights the contribution of the transcriptional architecture to the period dynamics and might be helpful in the construction of synthetic oscillators.
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Pinned chemical waves in the presence of Stokes flow.
J Phys Chem A
PUBLISHED: 08-11-2014
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Excitable reaction-diffusion systems form a wealth of dissipative concentration patterns that exist not only in chemical systems but also control or disrupt biological functions. An important example are rotating spiral waves in the autocatalytic Belousov-Zhabotinsky reaction. We show that the viscosity of this system can be increased by the addition of the polymer xanthan gum. In the resulting system, we pin spiral waves to a thin glass rod and then reposition the vortex centers by a linear motion of the heterogeneity. The Stokes flow generated by this motion can be a weak perturbation to the wave pattern and follows a simple, analytical expression. Numerical simulations of a corresponding reaction-diffusion-flow model reproduce the experimental observations and show that the spatial extent of the flow field can vary widely around the characteristic wavelength of the spiral. We find that a sharp spatial decay of the flow pattern corresponds to our experimental observations, whereas more expansive flow fields surprisingly allow the repositioning of spiral tips at speeds faster than the wave velocity.
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Synthesis of PbS/PbI2 nanocomposites in mixed solvent and their composition-dependent electrogenerated chemiluminescence performance.
Inorg Chem
PUBLISHED: 08-01-2014
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PbS/PbI2 nanocomposites were prepared by choosing K[PbI3] as both a lead salt and an iodide precursor and acetone/water as a reaction medium. It was found that the amount of the PbI2 component could be controlled, to some extent, by varying the amount of water used. Further, this simple bicomponent precursor-based synthetic route can be extended to prepare other lead-containing nanocomposites such as Pb3O4/PbI2 and PbSe/PbI2. Because of the heavy-atom effect, PbS/PbI2 nanocomposites exhibited good and composition-dependent electrogenerated chemiluminescence (ECL) performance, demonstrating their potential in the development of novel ECL sensors for analytical and clinical applications. These interesting findings would encourage us to gain deep insight on these phenomena, which could lead to the further development of these new inorganic materials and their applications.
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A phosphomolybdic acid anion probe-based label-free, stable and simple electrochemical biosensing platform.
Chem. Commun. (Camb.)
PUBLISHED: 07-09-2014
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A versatile label-free, stable, low-cost and simple electrochemical biosensing platform has been developed based on a phosphomolybdic acid anion probe by jointly taking advantages of its native electronegativity, electrochemical activity and chemisorption with graphene oxide.
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A novel in situ device based on a bionic piezoelectric actuator to study tensile and fatigue properties of bulk materials.
Rev Sci Instrum
PUBLISHED: 07-03-2014
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In this work, a miniaturized device based on a bionic piezoelectric actuator was developed to investigate the static tensile and dynamic fatigue properties of bulk materials. The device mainly consists of a bionic stepping piezoelectric actuator based on wedge block clamping, a pair of grippers, and a set of precise signal test system. Tensile and fatigue examinations share a set of driving system and a set of signal test system. In situ tensile and fatigue examinations under scanning electron microscope or metallographic microscope could be carried out due to the miniaturized dimensions of the device. The structure and working principle of the device were discussed and the effects of output difference between two piezoelectric stacks on the device were theoretically analyzed. The tensile and fatigue examinations on ordinary copper were carried out using this device and its feasibility was verified through the comparison tests with a commercial tensile examination instrument.
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Structure-activity relationship study of dibenzocyclooctadiene lignans isolated from Schisandra chinensis on lipopolysaccharide-induced microglia activation.
Planta Med.
PUBLISHED: 06-25-2014
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To explore the relationship of the dibenzocyclooctadiene lignans from Schisandra chinensis to their anti-inflammatory activities, series of dibenzocyclooctadiene lignans were isolated and assessed by testing their inhibitory effects on nitric oxide production in lipopolysaccharide-induced BV2 mouse microglia. It was found, for the first time, that dibenzocyclooctadiene lignans which have S-biphenyl and methylenedioxy groups strongly inhibited LPS-induced microglia activation. The methoxy group on the cyclooctadiene introduced more effectiveness, but the presence of an acetyl group on the cyclooctadiene or hydroxyl group on C-7 decreased the inhibitory activity.
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XRCC2 rs3218536 polymorphism decreases the sensitivity of colorectal cancer cells to poly(ADP-ribose) polymerase 1 inhibitor.
Oncol Lett
PUBLISHED: 06-11-2014
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Single nucleotide polymorphisms (SNPs) are associated with the development of certain types of cancer. The present study aimed to investigate the association between X-ray repair complementing defective repair in Chinese hamster cells 2 (XRCC2) SNPs and colorectal cancer (CRC) cell sensitivity to the poly(ADP-ribose) polymerase (PARP) 1 inhibitor olaparib (AZD2281). SNaPshot(®) analysis of XRCC2 SNPs was performed in five CRC cell lines. The AZD2281-sensitivities of the CRC cells were also analyzed using MTT assays. The effect of AZD2281 on XRCC2 and PARP1 expression was investigated in the five cell lines using quantitative polymerase chain reaction and western blot analyses. Parallel investigations were performed using a cisplatin (DDP) model of DNA damage. The XRCC2 rs3218536 SNP was found to be associated with the LoVo microsatellite instability CRC cell line. The relative rate of growth inhibition was found to be lower in the LoVo cells following treatment with AZD2281 compared with the other four cell lines (P=0.002). Furthermore, the XRCC2 mRNA level in the LoVo cells was observed to be significantly higher than that in the other four cell lines (P<0.05). Similar results were found using the DDP model of DNA damage (P<0.05). The present study indicated that the XRCC2 rs3218536 polymorphism decreases the sensitivity of CRC cells to AZD2281.
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Potential therapeutic mechanism of genistein in breast cancer involves inhibition of cell cycle regulation.
Mol Med Rep
PUBLISHED: 05-29-2014
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Genistein can prevent tumorigenesis and reduce the incidence of diseases that are dependent upon estrogen. Previous research, however, has shown that genistein can also increase the risk of breast cancer. Thus, the aim of the present study was to investigate the mechanism underlying the effect of genistein in breast cancer and to determine whether genistein produces a therapeutic effect or promotes the development of breast cancer. Gene microarray data obtained from three samples treated with alcohol (control group), three samples treated with 3 µmol/l genistein and three samples treated with 10 µmol/l genistein for 48 h, were downloaded from the Gene Expression Omnibus database. Analysis of the differentially expressed genes (DEGs) and functional enrichment in the two genistein groups was performed. The interaction networks of the DEGs were constructed and the overlapping network was extracted. Finally, the functions and pathways of the DEGs in the overlapping network were enriched. In total, 224 DEGs coexisted in the two genistein groups, and the most significant function of these was the cell cycle. The number and the fold change of expression values of the DEGs in the 10 µmol/l genistein group were significantly higher compared with that of the 3 µmol/l genistein group. The most significant function and pathway of the DEGs in the overlapping network was the cell cycle involving several genes, including GLIPR1, CDC20, BUB1, MCM2 and CCNB1. Thus, genistein stimulation resulted in gene expression changes in breast cancer cell lines and discrepancies increased with higher doses of genistein. The DEGs were most significantly associated with cell cycle regulation.
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Dibenzocyclooctadiene lignans from Schisandra chinensis and their inhibitory activity on NO production in lipopolysaccharide-activated microglia cells.
Phytochemistry
PUBLISHED: 05-23-2014
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Four dibenzocyclooctadiene lignans, schisanchinins A-D, and 10 known compounds were isolated from the EtOAc extract of fruits of Schisandra chinensis (Turcz.) Baill. Structures of compounds 1-4 were elucidated using a combination of spectroscopic techniques, including MS, UV and IR, NMR ((1)H NMR, (13)C NMR, HMQC, HMBC). The stereochemistry of the chiral centers and the biphenyl configuration were determined using NOESY, as well as analysis of CD spectra. In vitro activity assays showed that 11 of the 14 compounds exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary murine BV2 microglia cells.
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Interferon-? regulates the function of mesenchymal stem cells from oral lichen planus via indoleamine 2,3-dioxygenase activity.
J. Oral Pathol. Med.
PUBLISHED: 05-19-2014
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Little is known about mesenchymal stem cells (MSCs) in normal or inflammatory oral mucosal tissues, such as in oral lichen planus (OLP). Our objectives were to identify, isolate, and characterize MSCs from normal human oral mucosa and OLP lesions, and to evaluate indoleamine 2,3 dioxygenase (IDO) activity in mediating immunomodulation of MSCs from these tissues.
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The antibacterial activity of phytochemically characterised fractions from Folium Syringae.
Nat. Prod. Res.
PUBLISHED: 05-08-2014
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To identify the most active antimicrobial fraction of Folium Syringae, four common pathogens were used in an in vitro screening. The results indicated that the combination of the 30% and 60% ethanol fraction (FSC) obtained from the water extraction was the most active fraction with a minimal inhibitory concentration of 0.65 mg mL(-1). FSC was also found to be able to protect mice from a lethal infection of Staphylococcus aureus at clinical dosage (0.2 g kg(-1)) with a survival rate of 83.3%. The antibacterial activity of FSC was then tested using the serum pharmacology method which revealed that FSC exhibits a more long-lasting activity than the positive control (levofloxacin hydrochloride). The main components were confirmed to be iridoid glycosides and flavones by HPLC-MS analysis.
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Apoptosis of human tongue squamous cell carcinoma cell (CAL-27) induced by Lactobacillus sp. A-2 metabolites.
J Appl Oral Sci
PUBLISHED: 05-06-2014
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To study the effect of Lactobacillus sp. A-2 metabolites on viability of CAL-27 cells and apoptosis in CAL-27 cells.
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Biomimetic superoxide dismutase stabilized by photopolymerization for superoxide anions biosensing and cell monitoring.
Anal. Chem.
PUBLISHED: 05-06-2014
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Photopolymerization strategy, as one of the immobilization methods, has attracted considerable interest because of some advantages, such as easy operation, harmlessness to the biomolecules, and long storage stability. (E)-4-(4-Formylstyryl) pyridine (formylstyrylpyridine) was prepared through Heck reaction and used as a photopolymer material to immobilize biomimetic superoxide dismutase under ultraviolet irradiation (UV) irradiation in a short time. The styrylpyridinium moiety of Formylstyrylpyridine was photoreactive and formed a dimer under UV irradiation. Mn2P2O7 multilayer sheet, a novel superoxide dismutase mimic, was synthesized. The formed photopolymer can immobilize Mn2P2O7 firmly under UV irradiation. On the basis of high catalytic activity of Mn2P2O7 biomimetic enzyme and long-term stability of Mn2P2O7-formylstyrylpyridine film, after introducing multiwalled carbon nanotubes (MWCNTs), a novel electrochemical biosensing platform called MWCNTs/Mn2P2O7-formylstyrylpyridine for superoxide anion (O2(•-)) detection was constructed. The biosensor displayed good performance for O2(•-) detection and provided a reliable platform to adhere living cells directly on the modified electrode surface. Therefore, the biosensor was successfully applied to vitro determination of O2(•-) released from living cells, which had a promising prospect for living cells monitoring and diagnosis of reactive oxygen species-related diseases.
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[HER-2 overexpression and gene amplification of advanced breast cancers determined by fluorescence in situ hybridization in fine needle aspiration specimens].
Zhonghua Zhong Liu Za Zhi
PUBLISHED: 05-03-2014
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To explore the feasibility of testing HER-2 expression and gene amplification in fine needle aspiration specimens of advanced breast cancers, and to benefit the patients receiving targeted drug therapy.
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Ambidalmines A-E and ambidimerine F: bioactive dihydrobenzophenanthridine alkaloids from Corydalis ambigua var. amurensis.
Eur J Med Chem
PUBLISHED: 04-23-2014
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Ten new scarce dihydrobenzophenanthridine alkaloids, including seven monomers, ambidalmines A(1/2), B(1/2)-E (1(a/b), 2(a/b)-5), and three dimers, ambidimerines F1 (6a), F2 (6b) and F3 (6c), were isolated from the tubers of Corydalis ambigua var. amurensis. All of these compounds were discovered in the forms of enantiomers. The structures were elucidated based on extensive spectroscopic analysis, with absolute configurations of the enantiomeric compounds assigned by single-crystal X-ray diffraction analysis, circular dichroism (CD) and optical rotations. Bioactivity evaluation showed that compounds 1a, 2a, 2b and 6b exhibit comparable protective effects on hypoxic H9C2 cells.
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[Changes of blood pressure and S-100B, neuron specific enolase protein in hypertensive dogs after renal sympathetic denervation].
Zhong Nan Da Xue Xue Bao Yi Xue Ban
PUBLISHED: 04-22-2014
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To observe the changes of blood pressure and S-100B, neuron specific enolase (NSE) protein in hypertensive dogs with high fat diet after catheter-based renal sympathetic denervation.
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Quality of life in rectal cancer patients after radical surgery: a survey of Chinese patients.
World J Surg Oncol
PUBLISHED: 04-20-2014
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We aimed to investigate the impact of sociodemographic and clinical characteristics on health-related quality of life (HRQoL) in disease-free survivors after radical surgery for rectal cancer in a Chinese mainland population.
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Factors influencing disease progression of prostate cancer under active surveillance: a McGill University Health Center cohort.
BJU Int.
PUBLISHED: 04-02-2014
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To evaluate the clinical and pathological factors influencing the risk of disease progression in a cohort of patients with low-intermediate risk prostate cancer under active surveillance (AS).
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Three alkaloids from Reineckia carnea herba and their antitussive and expectorant activities.
Nat. Prod. Res.
PUBLISHED: 03-31-2014
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Three alkaloids, (3-chloro-2-hydroxypropyl) trimethylammonium chloride (1), p-(acetylamino)-phenol (2) and 4,4'-diacetamidodiphenyl ether (3), were isolated from Reineckia carnea herba. Their structures were determined by detailed analysis of their 1D and 2D NMR spectra and MS. Compounds 1 and 3 were new natural products. Compound 2 was isolated for the first time from the Reineckia genus. Compound 1 displayed significant in vivo antitussive and expectorant activities.
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Two-dimensional tin selenide nanostructures for flexible all-solid-state supercapacitors.
ACS Nano
PUBLISHED: 03-10-2014
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Due to their unique electronic and optoelectronic properties, tin selenide nanostructures show great promise for applications in energy storage and photovoltaic devices. Despite the great progress that has been achieved, the phase-controlled synthesis of two-dimensional (2D) tin selenide nanostructures remains a challenge, and their use in supercapacitors has not been explored. In this paper, 2D tin selenide nanostructures, including pure SnSe2 nanodisks (NDs), mixed-phase SnSe-SnSe2 NDs, and pure SnSe nanosheets (NSs), have been synthesized by reacting SnCl2 and trioctylphosphine (TOP)-Se with borane-tert-butylamine complex (BTBC) and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone. Utilizing the interplay of TOP and BTBC and changing only the amount of BTBC, the phase-controlled synthesis of 2D tin selenide nanostructures is realized for the first time. Phase-dependent pseudocapacitive behavior is observed for the resulting 2D nanostructures. The specific capacitances of pure SnSe2 NDs (168 F g(-1)) and SnSe NSs (228 F g(-1)) are much higher than those of other reported materials (e.g., graphene-Mn3O4 nanorods and TiN mesoporous spheres); thus, these tin selenide materials were used to fabricate flexible, all-solid-state supercapacitors. Devices fabricated with these two tin selenide materials exhibited high areal capacitances, good cycling stabilities, excellent flexibilities, and desirable mechanical stabilities, which were comparable to or better than those reported recently for other solid-state devices based on graphene and 3D GeSe2 nanostructures. Additionally, the rate capability of the SnSe2 NDs device was much better than that of the SnSe NS device, indicating that SnSe2 NDs are promising active materials for use in high-performance, flexible, all-solid-state supercapacitors.
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Uniform theoretical description of plasmon-induced transparency in plasmonic stub waveguide.
Opt Lett
PUBLISHED: 02-25-2014
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We investigate a classic analog of electromagnetically induced transparency (EIT) in a metal-dielectric-metal (MDM) bus waveguide coupled to two stub resonators. A uniform theoretical model, for both direct and indirect couplings between the two stubs, is established to study spectral features in the plasmonic stub waveguide, and the theoretical results agree well with the finite difference time domain simulations. Adjusting phase difference and coupling strength of the interaction, one can realize the EIT-like phenomena and achieve the required slow light effect. The theoretical results may provide a guideline for the control of light in highly integrated optical circuits.
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Triptolide improves early survival of mesenchymal stem cells transplanted into rat myocardium.
Cardiology
PUBLISHED: 02-18-2014
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To investigate whether triptolide can prolong the survival of rat mesenchymal stem cells (MSCs) transfected with the mouse hyperpolarization-activated cyclic nucleotide-gated channel 4 (mHCN4) gene in the myocardium.
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Bone marrow fat accumulation accelerated by high fat diet is suppressed by exercise.
Bone
PUBLISHED: 02-17-2014
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Marrow adipose tissue (MAT), associated with skeletal fragility and hematologic insufficiency, remains poorly understood and difficult to quantify. We tested the response of MAT to high fat diet (HFD) and exercise using a novel volumetric analysis, and compared it to measures of bone quantity. We hypothesized that HFD would increase MAT and diminish bone quantity, while exercise would slow MAT acquisition and promote bone formation. Eight week-old female C57BL/6 mice were fed a regular (RD) or HFD, and exercise groups were provided voluntary access to running wheels (RD-E, HFD-E). Femoral MAT was assessed by ?CT (lipid binder osmium) using a semi-automated approach employing rigid co-alignment, regional bone masks and was normalized for total femoral volume (TV) of the bone compartment. MAT was 2.6-fold higher in HFD relative to RD mice. Exercise suppressed MAT in RD-E mice by more than half compared with RD. Running similarly inhibited MAT acquisition in HFD mice. Exercise significantly increased bone quantity in both diet groups. Thus, HFD caused significant accumulation of MAT; importantly running exercise limited MAT acquisition while promoting bone formation during both diets. That MAT is exquisitely responsive to diet and exercise, and its regulation by exercise appears to be inversely proportional to effects on exercise induced bone formation, is relevant for an aging and sedentary population.
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Preparation of monodisperse ferrite nanocrystals with tunable morphology and magnetic properties.
Chem Asian J
PUBLISHED: 01-30-2014
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The synthesis of monodisperse magnetic ferrite nanomaterials plays an important role in several scientific and technological areas. In this work, dibasic spinel MFe2O4 (M=Mg, Ni, Co, Fe, Mn) and polybasic spinel ferrite MCoFeO4 (M=Mg, Ni, Mn, MgNi) nanocrystals were prepared by the calcination of layered double hydroxide (LDH) precursors at 900?°C, which was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images demonstrate that the as-obtained spinel ferrites present a single-crystalline nature with uniform particle size and good dispersibility. The composition, morphology, and particle size can be effectively tuned by changing the metal ratio, basicity, reaction time, and temperature of the LDH precursors. In addition, these spinel ferrites show high magnetic saturation values in the range 21.7-84.3?emu?g(-1), which maintain a higher level than the previously reported magnetic nanoparticles. Therefore, this work provides a facile approach for the design and fabrication of spinel ferrites with controllable nanostructure and improved magnetism, which could potentially be used in magnetic and biological fields, such as recording media, sensors, drug delivery, and intracellular imaging.
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Proteomic profiling of human placenta-derived mesenchymal stem cells upon transforming LIM mineralization protein-1 stimulation.
Cytotechnology
PUBLISHED: 01-28-2014
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Human placenta-derived mesenchymal stem cells (hPDMSCs) can differentiate into different types of cells and thus have tremendous potential for cell therapy and tissue engineering. LIM mineralization protein-1 (LMP-1) plays an important role in osteoblast differentiation, maturation and bone formation. To determine a global effect of LMP-1 on hPDMSCs, we designed a study using a proteomic approach combined with adenovirus-mediated gene transfer of LMP-1 to identify LMP-1-induced changes in hPDMSCs on proteome level. We have generated proteome maps of undifferentiated hPDMSCs and LMP-1 induced hPDMSCs. Two dimensional gel electrophoresis revealed 22 spots with at least 2.0-fold changes in expression and 15 differently expressed proteins were successfully identified by MALDI-TOF-MS. The proteins regulated by LMP-1 included cytoskeletal proteins, cadmium-binding proteins, and metabolic proteins, etc. The expression of some identified proteins was confirmed by further Western blot analyses. Our results will play an important role in better elucidating the underlying molecular mechanism in LMP-1 included hPDMSCs differentiation into osteoblasts.
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Comparative proteomic analysis of methyl jasmonate-induced defense responses in different rice cultivars.
Proteomics
PUBLISHED: 01-20-2014
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Jasmonate is an important endogenous chemical signal that plays a role in modulation of plant defense responses. To understand its mechanisms in regulation of rice resistance against the fungal pathogen Magnaporthe oryzae, comparative phenotype and proteomic analyses were undertaken using two near-isogenic cultivars with different levels of disease resistance. Methyl-jasmonate (MeJA) treatment significantly enhanced the resistance against M. oryzae in both cultivars but the treated resistant cultivar maintained a higher level of resistance than the same treated susceptible cultivars. Proteomic analysis revealed 26 and 16 MeJA-modulated proteins in resistant and susceptible cultivars, respectively, and both cultivars shared a common set of 13 proteins. Cumulatively, a total of 29 unique MeJA-influenced proteins were identified with many of them known to be associated with plant defense response and ROS accumulation. Consistent with the findings of proteomic analysis, MeJA treatment increased ROS accumulation in both cultivars with the resistant cultivar showing higher levels of ROS production and cell membrane damage than the susceptible cultivar. Taken together, our data add a new insight into the mechanisms of overall MeJA-induced rice defense response and provide a molecular basis of using MeJA to enhance fungal disease resistance in resistant and susceptible rice cultivars.
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Using ruthenium polypyridyl functionalized ZnO mesocrystals and gold nanoparticle dotted graphene composite for biological recognition and electrochemiluminescence biosensing.
Nanoscale
PUBLISHED: 01-17-2014
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Using ruthenium polypyridyl functionalized ZnO mesocrystals as bionanolabels, a universal biological recognition and biosensing platform based on gold nanoparticle (AuNP) dotted reduced graphene oxide (rGO) composite was developed. AuNP-rGO accelerated electron transfer between the detection probe and the electrode, and increased the surface area of the working electrode to load greater amounts of the capture antibodies. The large surface area of ZnO mesocrystals was beneficial for loading a high content ruthenium polypyridyl complex, leading to an enhanced electrochemiluminescence signal. Using ?-fetoprotein (AFP) as a model, a simple and sensitive sandwich-type electrochemiluminescence biosensor with tripropylamine (TPrA) as a coreactant for detection of AFP was constructed. The designed biosensor provided a good linear range from 0.04 to 500 ng mL(-1) with a low detection limit of 0.031 ng mL(-1) at a S/N of 3 for AFP determination. The proposed biological recognition and biosensing platform extended the application of ruthenium polypyridyl functionalized ZnO mesocrystals, which provided a new promising prospect.
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Electrochemical monitoring of an important biomarker and target protein: VEGFR2 in cell lysates.
Sci Rep
PUBLISHED: 01-16-2014
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Vascular endothelial growth factor receptor 2 (VEGFR2) is a potential cell-type biomarker in clinical diagnoses. Besides, it's the target protein of many tyrosine kinase inhibitors and its expression significantly associates with clinical performance of these inhibitors. VEGFR2 detection provides an early warning for diseases and a basis for therapy and drug screening. Some methods have been developed for VEGFR2 determination. However, they are usually performed indirectly and complexly. Herein, an electrochemical biosensing platform for VEGFR2 analysis has been first proposed. It can detect the total concentrations of the VEGFR2 protein in cells lysates directly and can be used to monitor the changes of VEGFR2 expression levels induced by treatments of different inhibitors. Moreover, the inhibitor-VEGFR2 interactions are illuminated through theoretical simulation. The simulation results agree well with the experimental data, indicating the veracity of the proposed method. The electrochemical detection methodology for VEGFR2 would be promising in clinical diagnosis and drug screening.
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In situ generated AgBr-enhanced ZnO nanorod-based photoelectrochemical aptasensing via layer-by-layer assembly.
Chem. Commun. (Camb.)
PUBLISHED: 01-13-2014
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A robust aptasensor for Ag(+) was proposed for the first time using an enhanced ZnO nanorod-based photoelectrochemistry by in situ generated AgBr via layer-by-layer assembly. This work opens up new avenues for application of one-dimensional ZnO nanorod arrays in photoelectrochemical sensing. Additionally, the strategy of employing in situ generated narrow-bandgap semiconductors paves a new way for photoelectrochemical sensing.
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Well-coupled graphene and Pd-based bimetallic nanocrystals nanocomposites for electrocatalytic oxygen reduction reaction.
ACS Appl Mater Interfaces
PUBLISHED: 01-13-2014
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In this paper, a series of well-coupled graphene (G) and MPd3 (M = Fe, Cu, Ag, Au, Cr, Mo, W) nanocrystals nanocomposites (G-MPd3 NCPs) have been synthesized via a versatile electrostatic assembly and hydrogen reduction strategy, i.e., sequential assembly of coordination anions and cations on excess cationic polymer modified graphene oxide to form composite precursors and then thermal treating under H2/Ar gases atmosphere. In those NCPs, the MPd3 components are uniform and smaller than 10 nm, which are well anchored on G with "naked" or "clean" surfaces. By adjusting reaction temperature, the interplay of MPd3 nanocrystals and G can be well-controlled. Below 700 °C, no sintering phenomena are observed, indicating the unprecedented dispersion and stability effect of G for MPd3 nanocrystals. All the obtained NCPs can be directly used to catalyze oxygen reduction reaction in alkaline media. Compared with single component, monometallic, and some reported non-Pt catalysts, greatly enhanced electrocatalytic performances are observed in those NCPs due to strong synergistic or coupling of their constituents. Among them, G-FePd3 NCPs exhibit the highest catalytic activity, but their current density needs to be improved compared with G-CrPd3, G-MoPd3, and G-WPd3 ones. This work not only provides a general strategy for fabricating well-coupled G-MPd3 NCPs but also paves the way for future designing multicomponent NCPs with multiple interfaces to apply in alkaline fuel cells.
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miR-107 Activates ATR/Chk1 Pathway and Suppress Cervical Cancer Invasion by Targeting MCL1.
PLoS ONE
PUBLISHED: 01-01-2014
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MicroRNAs (miRNAs) are a class of single-stranded, non-coding RNAs of about 22 nucleotides in length. Increasing evidence implicates miRNAs may function as oncogenes or tumor suppressors. Here we showed that miR-107 directly targeted MCL1 and activated ATR/Chk1 pathway to inhibit proliferation, migration and invasiveness of cervical cancer cells. Moreover, we found that MCL1 was frequently up-regulated in cervical cancer, and knockdown of MCL1 markedly inhibited cancer cell proliferation, migration and invasion, whereas ectopic expression of MCL1 significantly enhances these properties. The restoration of MCL1 expression can counteract the effect of miR-107 on the cancer cells. Together, miR-107 is a new regulator of MCL1, and both miR-107 and MCL1 play important roles in the pathogenesis of cervical cancer. We have therefore identified a mechanism for ATR/Chk1 pathway which involves an increase in miR-107 leading to a decrease in MCL1. Correspondingly, our results revealed that miR-107 affected ATR/Chk1 signalling and gene expression, and implicated miR-107 as a therapeutic target in human cervical cancer. We also demonstrated that taxol attenuated migration and invasion in cervical cancer cells by activating the miR-107, in which miR-107 play an important role in regulating the expression of MCL1. Elucidation of this discovered MCL1 was directly regulated by miR-107 will greatly enhance our understanding of the mechanisms responsible for cervical cancer and will provide an additional arm for the development of anticancer therapies.
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Tension-free repair during extensive radical surgery for cecal cancer with abdominal wall invasion and inguinal lymph node metastasis.
Ther Clin Risk Manag
PUBLISHED: 01-01-2014
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We report a case of cecal cancer with invasion of the abdominal wall and right inguinal lymph node metastasis. This patient had undergone an appendectomy 2 years previously. He underwent extensive radical right hemicolectomy with anastomosis and tension-free repair of the damaged right lower abdominal wall. The surgery progressed successfully, and the vital signs of the patient were stable (approximately 200 mL blood loss). Postoperative diagnosis revealed moderately to poorly differentiated adenocarcinoma of the cecum with invasion of the abdominal wall and metastasis of the inguinal lymph nodes (pT4bN2bM1, IV4a). The patient has remained well post-surgery.
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BMP9 inhibits proliferation and metastasis of HER2-positive SK-BR-3 breast cancer cells through ERK1/2 and PI3K/AKT pathways.
PLoS ONE
PUBLISHED: 01-01-2014
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Bone morphogenetic protein 9 (BMP9), a member of TGF-? superfamily, is reported to inhibit the growth and migration of prostate cancer, osteosarcoma and triple-negative MDA-MB-231 breast cancer cells. However, little is known about the effect of on the biological behaviors of HER2-positive SK-BR-3 breast cancer cells and the underlying mechanisms. This study aimed to investigate the effects of BMP9 on the proliferation and metastasis of SK-BR-3 cells with BMP9 over-expression or BMP9 down-regulated expression. Results indicated that exogenously expressed BMP9 inhibited the proliferation and metastasis of SK-BR-3 cells while decreased endogenous BMP9 expression in SK-BR-3 cells promoted the proliferation and migration of breast cancer cells in vitro and in vivo. In SK-BR-3 cells with BMP9 over-expression, the phosphorylation of HER2, ERK1/2 and AKT was markedly suppressed and the HER2 expression decreased at both mRNA and protein levels, while opposite results were observed in SK-BR-3 cells with BMP9 knock down. When the phosphorylation of ERK1/2 and PI3K/AKT was inhibited by PD98059 and LY294002, respectively, the decreased proliferation and invasion induced by BMP9 knock down were eliminated. These findings suggest that BMP9 can inhibit the proliferation and metastasis of SK-BR-3 cells via inactivating ERK1/2 and PI3K/AKT signaling pathways. Thus, BMP9 may serve as a useful agent in the treatment of HER-2 positive breast cancer.
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Duck enteritis virus glycoprotein D and B DNA vaccines induce immune responses and immunoprotection in Pekin ducks.
PLoS ONE
PUBLISHED: 01-01-2014
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DNA vaccine is a promising strategy for protection against virus infection. However, little is known on the efficacy of vaccination with two plasmids for expressing the glycoprotein D (gD) and glycoprotein B (gB) of duck enteritis virus (DEV) in inducing immune response and immunoprotection against virulent virus infection in Pekin ducks. In this study, two eukaryotic expressing plasmids of pcDNA3.1-gB and pcDNA3.1-gD were constructed. Following transfection, the gB and gD expressions in DF1 cells were detected. Groups of ducks were vaccinated with pcDNA3.1-gB and/or pcDNA3.1-gD, and boosted with the same vaccine on day 14 post primary vaccination. We found that intramuscular vaccinations with pcDNA3.1-gB and/or pcDNA3.1-gD, but not control plasmid, stimulated a high frequency of CD4+ and CD8+ T cells in Pekin ducks, particularly with both plasmids. Similarly, vaccination with these plasmids, particularly with both plasmids, promoted higher levels of neutralization antibodies against DEV in Pekin ducks. More importantly, vaccination with both plasmids significantly reduced the virulent DEV-induced mortality in Pekin ducks. Our data indicated that vaccination with plasmids for expressing both gB and gD induced potent cellular and humoral immunity against DEV in Pekin ducks. Therefore, this vaccination strategy may be used for the prevention of DEV infection in Pekin ducks.
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The anticonvulsant effects of SR 57227 on pentylenetetrazole-induced seizure in mice.
PLoS ONE
PUBLISHED: 01-01-2014
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Recently, studies have shown that serotonin plays an important role in the control of seizure. However, the specific role of 5-HT receptor subtypes is not yet well described, in particular that of the 5-HT3 receptor. The present study was aimed to investigate the role of 5-HT3 receptor on the pentylenetetrazole (PTZ)-induced seizure in mice. Firstly, seizure latency was significantly prolonged by a 5-HT3 receptor agonist SR 57227 in a dose-dependent manner. Seizure score and mortality were also decreased by SR 57227 in PTZ-treated mice. Furthermore, these anticonvulsant effects of SR 57227 were inhibited by a 5-HT3 receptor antagonist ondansetron. However, ondansetron alone had no effect on seizure latency, seizure score or mortality at different doses. Immunohistochemical studies have also shown that c-Fos expression was significantly increased in hippocampus (dentate gyrus, CA1, CA3 and CA4) of PTZ-treated mice. Furthermore, c-Fos expression was significantly inhibited by ondansetron in mice treated with PTZ and SR 57227. An ELISA study showed that SR 57227 attenuated the PTZ-induced inhibitory effects of GABA levels in hippocampus and cortex, and the attenuated effects of SR 57227 were antagonized by ondansetron in hippocampus but not cortex. Our findings suggest that activation of 5-HT3 receptor by SR 57227, which plays an important role on the control of seizure induced by PTZ, may be related to GABA activity in hippocampus. Therefore, 5-HT3 receptor subtype is a potential target for the treatment of epilepsy.
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miR-7 inhibits colorectal cancer cell proliferation and induces apoptosis by targeting XRCC2.
Onco Targets Ther
PUBLISHED: 01-01-2014
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Analysis using publicly available algorithms predicts that X-ray repair complementing defective repair in Chinese hamster cells 2 (XRCC2), a key component in the homologous recombination repair pathway, is a potential target of micro-ribonucleic acid-7 (miR-7). Some studies have shown that both miR-7 and XRCC2 are associated with cancer development. For this purpose, we searched for the possible relationship between miR-7 and XRCC2 in the development of colorectal cancer (CRC).
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4-(N,N-Dimethylamino)pyridine Hydrochloride as a Recyclable Catalyst for Acylation of Inert Alcohols: Substrate Scope and Reaction Mechanism.
Org. Lett.
PUBLISHED: 12-16-2013
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4-(N,N-Dimethylamino)pyridine hydrochloride (DMAP·HCl), a DMAP salt with the simplest structure, was used as a recyclable catalyst for the acylation of inert alcohols and phenols under base-free conditions. The reaction mechanism was investigated in detail for the first time; DMAP·HCl and the acylating reagent directly formed N-acyl-4-(N,N-dimethylamino)pyridine chloride, which was attacked by the nucleophilic substrate to form a transient intermediate that released the acylation product and regenerated the DMAP·HCl catalyst.
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Using graphene-based plasmonic nanocomposites to quench energy from quantum dots for signal-on photoelectrochemical aptasensing.
Anal. Chem.
PUBLISHED: 11-27-2013
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On the basis of the absorption and emission spectra overlap, an enhanced resonance energy transfer caused by excition-plasmon resonance between reduced graphene oxide (RGO)-Au nanoparticles (AuNPs) and CdTe quantum dots (QDs) was obtained. With the synergy of AuNPs and RGO as a planelike energy acceptor, it resulted in the enhancement of energy transfer between excited CdTe QDs and RGO-AuNPs nanocomposites. Upon the novel sandwichlike structure formed via DNA hybridization, the exciton produced in CdTe QDs was annihilated. A damped photocurrent was obtained, which was acted as the background signal for the development of a universal photoelectrochemical (PEC) platform. With the use of carcinoembryonic antigen (CEA) as a model which bonded to its specific aptamer and destroyed the sandwichlike structure, the energy transfer efficiency was lowered, leading to PEC response augment. Thus a signal-on PEC aptasensor was constructed. Under 470 nm irradiation at -0.05 V, the PEC aptasensor for CEA determination exhibited a linear range from 0.001 to 2.0 ng mL(-1) with a detection limit of 0.47 pg mL(-1) at a signal-to-noise ratio of 3 and was satisfactory for clinical sample detection. Since different aptamers can specifically bind to different target molecules, the designed strategy has an expansive application for the construction of versatile PEC platforms.
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[Apatite-forming ability of pure titanium implant after micro-arc oxidation treatment].
Nan Fang Yi Ke Da Xue Xue Bao
PUBLISHED: 10-23-2013
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To investigate the apatite forming ability of pure titanium implant after micro-arc oxidation treatment in simulated body fluid (SBF) and obtain implants with calcium phosphate (Ca-P) layers.
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Protective effect of demethylation treatment on cigarette smoke extract-induced mouse emphysema model.
J. Pharmacol. Sci.
PUBLISHED: 10-22-2013
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In the present study, we explored the effects of demethylation in a cigarette smoke extract (CSE)-induced mouse emphysema model. Animals were randomly assigned to the control group, CSE group, 5-aza-2-deoxycytidine (AZA) group, and CSE+AZA group (n = 10 per group). The mitochondrial transcription factor A (mtTFA) promoter methylation increased over 4-fold in the CSE group compared with the control group, which was reversed by AZA. The mtTFA and the cytochrome c oxidase subunit II (COX II) mRNA and protein levels were decreased approximately 3-fold in the CSE group compared with the control group, which was largely restored by AZA. Histological analysis showed that the CSE group exhibited emphysema compared with the control, which was alleviated by AZA. In addition, CSE significantly induced lung cell apoptosis and decreased lung function and lung mitochondrial COX activity, which was mostly restored by AZA. In conclusion, we for the first time provide evidence that demethylation therapy with AZA can effectively improve emphysema, lung function, lung cell apoptosis, and lung mitochondrial COX activity in a CSE-induced mouse emphysema model, which adds fresh insight into the therapeutic potential of demethylating agents in the prevention and treatment of cigarette smoke-induced emphysema.
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Research on a novel composite structure Er³?-doped DBR fiber laser with a ?-phase shifted FBG.
Opt Express
PUBLISHED: 10-10-2013
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A simple composite cavity structure Er³?-doped fiber laser was proposed and demonstrated experimentally. The resonant cavity consists of a pair of uniform fiber Bragg gratings (FBGs) and a ?-phase shifted FBG. By introducing the ?-phase shifted FBG into the cavity as the selective wavelength component, it can increase the effective length of the laser cavity and suppress the multi-longitudinal modes simultaneously. The narrow linewidth of 900 Hz and low RIN of -95 dB/Hz were obtained. And the lasing wavelength was rather stable with the pump power changing. The SMRS was more than 67 dB. The results show that the proposed fiber laser has a good performance and considerable potential application for fiber sensor and optical communication.
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Fringe phase extraction using windowed Fourier transform guided by principal component analysis.
Appl Opt
PUBLISHED: 10-03-2013
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The windowed Fourier transform (WFT) has been recognized as an effective tool for extracting phase map from a single fringe pattern. This paper presents a new WFT-based algorithm, which is guided by the principal component analysis (PCA) of the fringe pattern. With it, the principal direction of frequency at each pixel is determined first by using the PCA of the gradients of the fringe pattern, and then the windowed Fourier ridge for each pixel is detected by searching a one-dimensional space of frequency, so that the computational burden for phase extraction is alleviated significantly. In addition, this technique enables automatically identifying and excluding the regions of singular points from the fringe pattern by using the eigenvalues resulting from the PCA just mentioned. Numerical simulation and experiment are carried out to demonstrate the validity of this method.
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Phase shift estimation from variances of fringe pattern differences.
Appl Opt
PUBLISHED: 10-03-2013
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This paper presents a simple algorithm for estimating phase shifts from only three interferograms. In it, the fringe pattern differences are computed first in order to remove the background component, and then the variances and further the standard deviations (SDs) of fringe pattern differences are calculated. The phase shifts are estimated, by using the law of cosines, from a triangle whose lengths of sides are the SDs just calculated. This algorithm offers several advantages over others, e.g., being efficient, easy to implement, accurate, and less sensitive to noise. Numerical simulations and an experiment are performed to demonstrate its validity.
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A strategy for the molecular diagnosis in hemophilia a in Chinese population.
Cell Biochem. Biophys.
PUBLISHED: 09-11-2013
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Hemophilia A is an x-linked recessive inherited bleeding disorder. So far, more than 1,885 disease-causing mutations of factor VIII gene have been identified. Clinic confers a great challenge for the molecular diagnosis. We aim to make a better strategy for the molecular diagnosis in Hemophilia A. First, factor VIII intron 22 inversion and intron 1 inversion mutations were detected using Inversion-PCR and double-tube multiple PCRs. And then, non-inversion mutations were analyzed by denaturing high performance liquid chromatography and/or direct sequencing. Novel mutations were further analyzed the conservation and 3D structures by a B domain deleted crystallographic model and bioinformatics. Finally, we can indirectly confirm the diagnosis by linkage analysis for the patients with the confusing diagnosis by the techniques mentioned above. Eleven patients with the factor VIII Inv 22 were found, and the remaining 16 patients were found with 11 different mutations, of which 3 was novel mutations affecting A1, B domains and splicing site. Moreover, the prenatal diagnosis was performed on 14 fetuses. Ten fetuses were successfully confirmed to be normal, 1 fetus to be a heterozygote with factor VIII c.3275-3276 ins A and 3 fetuses to be hemizygotes with factor VIII Inv 22 mutation.
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Quantum dots sensitized titanium dioxide decorated reduced graphene oxide for visible light excited photoelectrochemical biosensing at a low potential.
Biosens Bioelectron
PUBLISHED: 09-10-2013
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A low potential and competitive photoelectrochemical biosensing platform was developed using quantum dots sensitized titanium dioxide decorated reduced graphene oxide (TiO2-RGO) nanocomposites. The nanocomposites were prepared through electrostatic interaction between mercaptoacetic acid wrapped CdSe quantum dots with negative charge and TiO2-RGO hybrids with positive charge obtained via ultrasonic and acid treatments. Electron microscopes and spectroscopes were used to characterize the functionalized nanocomposites films of CdSe/TiO2-RGO, and the fabrication process of the photoelectrochemical biosensor. Based on the high photovoltaic conversion efficiency of CdSe/TiO2-RGO nanocomposites films, after introducing biological recognition and competitive immunoreaction, a low potential and competitive photoelectrochemical biosensor for carcinoembryonic antigen (CEA) detection was fabricated. The synergic effect of horseradish peroxide and benzo-4-chlorohexadienone decreased the background signal, leading to signal amplification. Under the light irradiation of 430nm and the applied potential of 0V, the biosensor detected CEA with a linear range from 0.003 to 100ngmL(-1) and the detection limit was estimated to be 1.38pgmL(-1) at a S/N of 3. It was satisfactory for clinical sample detection. The proposed competitive and low potential photoelectrochemical biosensor under irradiation of visible light exhibited good performance, which has a promising prospect in clinical diagnose.
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Electric-field-controlled unpinning of scroll waves.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 08-23-2013
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Three-dimensional excitation vortices exist in systems such as chemical reactions and the human heart. Their one-dimensional rotation backbone can pin to unexcitable heterogeneities, which greatly affect the structure, dynamics, and lifetime of the vortex. In experiments with the Belousov-Zhabotinsky reaction, we demonstrate vortex unpinning from a pair of inert and impermeable spheres using externally applied electric fields. Unpinning occurs abruptly but is preceded by a slow reorientation and deformation of the initially circular vortex loop. Our experimental findings are reproduced by numerical simulations of an excitable reaction-diffusion-advection model.
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Enhancement of nonlinear Raman-Nath diffraction in two-dimensional optical superlattice.
Opt Express
PUBLISHED: 08-14-2013
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We study second harmonic generation via nonlinear Raman-Nath diffraction in an optical superlattice that maintains a periodic modulation of the second-order nonlinear coefficient ?((2)) in transverse direction but undergoes random modulation in longitudinal direction. We show that the random ?((2)) modulation offers a continuous set of reciprocal lattice vectors to compensate for the phase mismatch of nonlinear Raman-Nath diffraction in the longitudinal direction, leading to more efficient harmonic generation for a wide range of wavelengths. We also characterize the intensity dependence of nonlinear Raman-Nath diffraction on the degree of randomness of the optical supperlattice.
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What is Visualize?

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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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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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.