Serum brain derived neurotrophic factor levels and post-stroke depression in ischemic stroke patients.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) is crucial for neuronal survival and may be implicated in the pathophysiological process of depression. This study aimed to prospectively investigate the association between serum BDNF and post-stroke depression (PSD) at 3 months in a multicenter cohort study. METHODS: A total of 611 ischemic stroke patients with serum BDNF measurements from the China Antihypertensive Trial in Acute Ischemic Stroke were included in this analysis. We used the 24-item Hamilton Depression Rating Scale to assess depression status at 3 months after ischemic stroke, and PSD was defined as a score of ≥8. RESULTS: Baseline serum BDNF was inversely associated with the risk of depression after ischemic stroke. The multivariable-adjusted odds ratio of PSD for the highest tertile of BDNF was 0.53 (95 % confidence interval, 0.34-0.82; P for trend = 0.004) compared with the lowest tertile. Multivariable-adjusted spline regression model also showed a linear does-response association between serum BDNF levels and PSD at 3 months (P for linearity = 0.006). In addition, adding serum BDNF to conventional risk factors significantly improved the risk reclassification of PSD (net reclassification improvement: 16.98 %, P = 0.039; integrated discrimination index: 0.93 %, P = 0.026). LIMITATIONS: All patients in this study were Chinese, so our findings should be applied to other populations cautiously. CONCLUSIONS: Higher serum BDNF levels at baseline were significantly associated with a decreased risk of PSD at 3 months, suggesting that BDNF might be a valuable predictive biomarker and potential therapeutic target for PSD among ischemic stroke patients.

Comparative study on physicochemical characteristics, α-glucosidase inhibitory effect, and hypoglycemic activity of pectins from normal and Huanglongbing-infected navel orange peels.

This study aimed at comparing the physicochemical characteristics, α-glucosidase inhibitory effect, and hypoglycemic activity of pectins (N-NOP and H-NOP) from peels of normal and Huanglongbing (HLB)-infected Navel oranges. Results indicated the pectins were high methoxy pectins mainly composed of homogalacturonan and rhamnogalacturonan-I. The pectins exhibited similar functional groups, surface morphology, and particle size, and had no triple-helical conformation in solution. They exerted fat and glucose absorption capacities and were mixed-type noncompetitive α-glucosidase inhibitors with IC50 values of 1.182 and 2.524 mg/ml, respectively. Both N-NOP and H-NOP showed hypoglycemic activity in alloxan-induced diabetic mice. Administration of them could promote the synthesis of hepatic glycogen and/or serum insulin to lower blood glucose levels and enhance antioxidant status to alleviate oxidative stress injury in diabetic mice. Moreover, N-NOP had higher yield, molecular weight, ζ-potential, oil holding capacity, α-glucosidase inhibitory effect and in vivo hypoglycemic activity, whereas H-NOP possessed higher uronic acid, degree of esterification, thermal stability, water holding capacity, swelling capacity, and fat absorption capacity. It could be concluded that some similarities and differences existed between N-NOP and H-NOP in physicochemical characteristics, functional properties, α-glucosidase inhibitory effects, and hypoglycemic activity. This study provides references for the basic research and application of pectins from peels of normal and HLB-infected Navel oranges. PRACTICAL APPLICATIONS: Pectin has been widely used in the food and pharmaceutical industries for several decades due to its health benefit, gelling, thickening, and emulsification performances. Diabetes mellitus is a worldwide concern in recent years. Pectins (N-NOP and H-NOP) from peels of normal and Huanglongbing (HLB)-infected Navel oranges possessed in vitro and in vivo hypoglycemic activities, indicating they were potential anti-antidiabetic substitutes of chemical drugs. Moreover, comparative understanding on the physicochemical characteristic, α-glucosidase inhibitory effect and hypoglycemic activity of pectins from peels of normal and Huanglongbing-infected Navel oranges was conducive to the recycling and utilization of Navel orange peels. Recently, the biological activity of pectin from peels of normal Navel oranges has been rarely reported, and the information on pectin from peels of Huanglongbing-infected Navel orange is rare. This study provides references for the basic research and application of pectins from peels of normal and HLB-infected Navel oranges.

Creep-Fatigue Crack Initiation Simulation of a Modified 12% Cr Steel Based on Grain Boundary Cavitation and Plastic Slip Accumulation.

High-temperature components in power plants may fail due to creep and fatigue. Creep damage is usually accompanied by the nucleation, growth, and coalescence of grain boundary cavities, while fatigue damage is caused by excessive accumulated plastic deformation due to the local stress concentration. This paper proposes a multiscale numerical framework combining the crystal plastic frame with the meso-damage mechanisms. Not only can it better describe the deformation mechanism dominated by creep from a microscopic viewpoint, but also reflects the local damage of materials caused by irreversible microstructure changes in the process of creep-fatigue deformation to some extent. In this paper, the creep-fatigue crack initiation analysis of a modified 12%Cr steel (X12CrMoWvNBN10-1-1) is carried out for a given notch specimen. It is found that creep cracks usually initiate at the triple grain boundary junctions or at the grain boundaries approximately perpendicular to the loading direction, while fatigue cracks always initiate from the notch surface where stress is concentrated. In addition to this, the crack initiation life can be quantitatively described, which is affected by the average grain size, initial notch size, stress range and holding time.