Calcium signaling, manifested as intercellular waves of rising cytosolic calcium, is, in many cell types, the result of calcium-induced secretion of ATP and activation of purinergic receptors. The mechanism by which ATP is released has hitherto not been established. Here, we show by real-time bioluminescence imaging that ATP efflux is not uniform across a field of cells but is restricted to brief, abrupt point-source bursts. The ATP bursts emanate from single cells and manifest the transient opening of nonselective membrane channels, which admits fluorescent indicators of ≤1.5 kDa. These observations challenge the existence of regenerative ATP release, because ATP efflux is finite and restricted to a point source. Transient efflux of cytosolic nucleotides from a subset of cells may represent a conserved pathway for coordinating local activity of electrically nonexcitable cells, because identical patterns of ATP release were identified in human astrocytes, endothelial cells, and bronchial epithelial cells.
This study was undertaken to investigate the expression of hypoxia-inducible factor-1α (HIF-1α) in rat cerebral cortex and the effects of β-sodium aescinate (SA) administration after return of spontaneous circulation (ROSC).SIXTY RATS WERE DIVIDED INTO THREE GROUPS: SA group, injected intraperitoneally with SA instantly after ROSC; control group, injected intraperitoneally with normal saline; and sham-operated group, without cardiac arrest or SA. The cardiac arrest model was established using asphyxiation and intravenous potassium chloride. Blood was sampled 1, 6, 12, and 24 hours after ROSC. Protein and mRNA levels of HIF-1α, VEGF and EPO were detected in the cerebral cortex by immunohistochemistry and real-time RT-PCR; serum levels of NSE and S100β were determined by enzyme-linked immunosorbent assays.Serum S100β and NSE were significantly increased in the control group versus the sham-operated group 1, 6, 12 and 24 hours after ROSC (P<0.05). Protein and mRNA levels of HIF-1α, VEGF and EPO were significantly increased in the control rats (P<0.05). Serum NSE and S100β were significantly decreased in the SA group versus the control group 1, 6, 12 and 24 hours after ROSC (P<0.05). Protein and mRNA levels of HIF-1α, VEGF and EPO were significantly increased in the SA group (P<0.05).The expression of HIF-1α is increased in rat cerebral cortex after ROSC, and SA up-regulates the expression of HIF-1α. The up-regulation of HIF-1α improves the resistance of the cortex to ischemia and hypoxia and contributes to neuroprotection, possibly because of up-regulation of EPO and VEGF expression.
© 2017 Elsevier Ltd <br>The present study uses the isogeometric analysis (IGA) to investigate the post-buckling behavior of functionally graded (FG) microplates subjected to mechanical and thermal loads. The modified a strain gradient theory with three length scale parameters is used to capture the size effect. The Reddy third-order shear deformation plate theory with the von Kámán nonlinearity (i.e., small strains and moderate rotations) is employed to describe the kinematics of the microplates. Material variations in the thickness direction of the plate are described using a rule of mixtures. In addition, material properties are assumed to be either temperature-dependent or temperature-independent. The governing equations are derived using the principle of virtual work, which are then discretized using the IGA approach, whereby a C2-continuity requirement is fulfilled naturally and efficiently. To trace the post-buckling paths, Newton's iterative technique is utilized. Various parametric studies are conducted to examine the influences of material variations, size effects, thickness ratios, and boundary conditions on the post-buckling behavior of microplates.
Abstract Background: Clinical and basic research supports that blood glucose fluctuation is an important predictor of diabetic vascular disease and an etiology of lower extremity atherosclerosis, which is an important pathological basis for lower extremity vascular diseases. Previous Chinese National Natural Science Foundation trials (No. 81503566) have reported that the traditional Chinese medicine Shenqi compound can reduce blood glucose fluctuation and low-grade inflammation, and protect blood vessels; however, there are no high-quality clinical evidences available to support the same. This multicenter randomized controlled trial aims to obtain more clinical evidence to confirm the efficacy and safety of Shenqi compound in type 2 diabetes with lower extremity atherosclerosis. Methods: A multicenter RCT will be implemented in this study for a 32-week study period (8 weeks for intervention and 24 weeks for follow-up). Participants will be recruited from the Teaching Hospital of Chengdu University of TCM, Mianyang Hospital of TCM, and Shuangliu Hospital of TCM. Sixty participants will be randomly divided into a treatment group (basic treatment combined with traditional Chinese medicine Shenqi Compound) or a control group (basic treatment combined with Chinese medicine placebo) with 30 participants in each group. Patients will be selected considering the following inclusion criteria: age between 35 and 65 years, and a positive diagnosis for type 2 diabetes with lower extremity atherosclerosis and TCM syndromes. Primary outcome indicator is an arterial color Doppler ultrasound. Secondary outcome indicators include: blood glucose fluctuation indicators (MBG, SDBG, LAGE), islet β-cell function evaluation indicators (Homa-IR, Homa-islet, SG, SCP), inflammation indicators (NLR, CRP, IL-6), blood lipids, and HbA1c. Safety index includes vital signs (T, P, R, BP), blood, urine, stool routine, liver and renal function, electrocardiogram, and adverse event records. The endpoint event is defined as the presence of gangrene in the lower limbs. Discussion: Explore the clinical effect of traditional Chinese medicine “Shenqi Compound” to reduce blood glucose fluctuation and use HOMA-IR, the area under the glucose curve, and the area under the C-peptide curve to evaluate the effect of protecting islet β cell function. Trial registration : Chinese clinical trial registry (ChiCTR-1900027693). Registered on November 23, 2019. http://www.chictr.org.cn
Nowadays, many high-rise buildings are constructed from concrete-filled steel tubular (CFST) columns and concrete-filled steel plate (CFSP) shear walls due to their superior merits. However, these composite buildings are still designed by traditional load and resistance factor design (LRFD) approach which is conservative and impossible to explicitly capture the complex behaviour of CFST structures. Hence, this paper develops an efficient framework for the system design of CFST structures utilizing nonlinear simulation and reliability analysis. Firstly, a C+ + source code for a new material model is developed in OpenSees to capture the behaviour of semi-rigid connections. This material is implemented into the numerical model of CFST structures. Secondly, a framework based on subset simulation is developed for the reliability analysis. This code rigorously considers uncertainties of variables such as numerical model, geometric and material properties or applied loads of both American (US) and Australian (AS) standards. Finally, case study and parametric study are conducted by using the developed framework to propose resistance reduction factors for the investigated frames. The results of the study show that the resistance reduction factor can be taken as 0.8 for both AS and US codes. This proposed factor can be a great source of reference for the system design of CFST buildings with composite shear walls.