102 research outputs found
A Microcantilever-based Gas Flow Sensor for Flow Rate and Direction Detection
The purpose of this paper is to apply characteristics of residual stress that
causes cantilever beams to bend for manufacturing a micro-structured gas flow
sensor. This study uses a silicon wafer deposited silicon nitride layers,
reassembled the gas flow sensor with four cantilever beams that perpendicular
to each other and manufactured piezoresistive structure on each
micro-cantilever by MEMS technologies, respectively. When the cantilever beams
are formed after etching the silicon wafer, it bends up a little due to the
released residual stress induced in the previous fabrication process. As air
flows through the sensor upstream and downstream beam deformation was made,
thus the airflow direction can be determined through comparing the resistance
variation between different cantilever beams. The flow rate can also be
measured by calculating the total resistance variations on the four
cantilevers.Comment: Submitted on behalf of EDA Publishing Association
(http://irevues.inist.fr/handle/2042/16838
Levels and values of circulating endothelial progenitor cells, soluble angiogenic factors, and mononuclear cell apoptosis in liver cirrhosis patients
BACKGROUND: The roles of circulating endothelial progenitor cell (EPC) and mononuclear cell apoptosis (MCA) in liver cirrhosis (LC) patients are unknown. Moreover, vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1Ξ± are powerful endogenous substances enhancing EPC migration into circulation. We assessed the level and function of EPCs [CD31/CD34 (E(1)), KDR/CD34 (E(2)), CXCR4/CD34 (E(3))], levels of MCA, VEGF and SDF-1Ξ± in circulation of LC patients. METHODS: Blood sample was prospectively collected once for assessing EPC level and function, MCA, and plasma levels of VEGF and SDF-1Ξ± using flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively, in 78 LC patients and 25 age- and gender-matched healthy controls. RESULTS: Number of EPCs (E(1), E(2), E(3)) was lower (all pβ<β0.0001), whereas SDF-1Ξ± level and MCA were higher (pβ<β0.001) in study patients compared with healthy controls. Number of EPCs (E(2), E(3)) was higher but MCA was lower (all pβ<β0.05) in Child's class A compared with Child's class B and C patients, although no difference in VEGF and SDF-1Ξ± levels were noted among these patients. Chronic hepatitis B and esophageal varices bleeding were independently, whereas chronic hepatitis C, elevated aspartate aminotransferase (AST), and decompensated LC were inversely and independently correlated with circulating EPC level (all pβ<β0.03). Additionally, angiogenesis and transwell migratory ability of EPCs were reduced in LC patients than in controls (all pβ<β0.001). CONCLUSION: The results of this study demonstrated that level, angiogenic capacity, and function of circulating EPCs were significantly reduced, whereas plasma levels of SDF-1Ξ± and circulating MCA were substantially enhanced in cirrhotic patients
Intra-coronary administration of tacrolimus markedly attenuates infarct size and preserves heart function in porcine myocardial infarction
BACKGROUND: We test the hypothesis that intra-coronary tacrolimus administration can limit infarct size and preserve left ventricular ejection fraction (LVEF) after acute myocardial infarction (AMI) through ligating left anterior descending coronary artery (LAD) in mini-pigs. METHODS: Twelve male mini-pigs were randomized into AMI-saline (MI-only) group and AMI-tacrolimus (MI-Tac) group that received intra-coronary saline (3.0βmL) and tacrolimus (0.5βmg in 2.5βmL saline) injection, respectively, beyond site of ligation 30 minutes after LAD occlusion. RESULTS: Larger infarct area was noted in MI-only group (pβ<β0.001). Inflammatory biomarkers at protein [oxidative stress, tumor necrotic factor-Ξ±, nuclear factor-ΞΊB], gene (matrix metalloproteinase-9, plasminogen activator inhibitor-1), and cellular (CD40+, CD68+ inflammatory cells) levels were remarkably higher in MI-only animals (pβ<β0.01). Conversely, anti-inflammatory biomarkers at gene level (Interleukin-10), gene and protein level (endothelial nitric oxide synthase), and anti-oxidant biomarkers at both gene and protein levels [heme oxygenase 1, NAD(P)H:quinone oxidoreductase] were lower in MI-only group (pβ<β0.01). Number of apoptotic nuclei and apoptotic biomarkers expressions at gene and protein levels (Bax, caspase 3) were notably higher, whereas anti-apoptotic biomarkers at gene and protein levels (Bcl-2), LVEF, and fractional shortening were markedly lower in MI-only group (pβ<β0.001). CONCLUSION: Intra-coronary administration of tacrolimus significantly attenuated infarct size and preserved LV function
A Genome-Wide Association Study Identifies Susceptibility Variants for Type 2 Diabetes in Han Chinese
To investigate the underlying mechanisms of T2D pathogenesis, we looked for diabetes susceptibility genes that increase the risk of type 2 diabetes (T2D) in a Han Chinese population. A two-stage genome-wide association (GWA) study was conducted, in which 995 patients and 894 controls were genotyped using the Illumina HumanHap550-Duo BeadChip for the first genome scan stage. This was further replicated in 1,803 patients and 1,473 controls in stage 2. We found two loci not previously associated with diabetes susceptibility in and around the genes protein tyrosine phosphatase receptor type D (PTPRD) (Pβ=β8.54Γ10β10; odds ratio [OR]β=β1.57; 95% confidence interval [CI]β=β1.36β1.82), and serine racemase (SRR) (Pβ=β3.06Γ10β9; ORβ=β1.28; 95% CIβ=β1.18β1.39). We also confirmed that variants in KCNQ1 were associated with T2D risk, with the strongest signal at rs2237895 (Pβ=β9.65Γ10β10; ORβ=β1.29, 95% CIβ=β1.19β1.40). By identifying two novel genetic susceptibility loci in a Han Chinese population and confirming the involvement of KCNQ1, which was previously reported to be associated with T2D in Japanese and European descent populations, our results may lead to a better understanding of differences in the molecular pathogenesis of T2D among various populations
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