304 research outputs found
Tolerance to freezing stress in cyanobacteria, Nostoc commune and some cyanobacteria with various tolerances to drying stress
Tolerance to and effects of the freezing stress in a desiccation-tolerant, terrestrial cyanobacterium, Nostoc commune, in cultivated strains of N. commune, and in desiccation-sensitive species, Synechocystis sp. PCC6803 and Fischerella muscicola, were studied by measuring their photosynthetic activities and fluorescence emission spectra. The results showed that a strain or species with higher desiccation tolerance was more tolerant to freezing stress than one with lower desiccation tolerance, which is consistent with the idea that tolerance to freezing stress is related to resistance to drying stress. Under freezing conditions, light energy absorbed by photosystem (PS) II complexes was dissipated to heat energy in N. commune, which may protect the cells from photoinactivation. N. commune encountered cellular dehydration due to ice formation outside the cell under freezing conditions. But NMR data showed that relatively high amounts of water still remained in a liquid state inside the cells at -36_C when N. commune colonies were fully wetted before freezing. High PSI activities measured by P700 photooxidation also support the result that non-freezing water remains within the cells. Besides, 5% methanol enhanced the resistance to freezing stress in the sensitive species. This effect seems to be related to maintenance of the PSI activity and pigment-protein complexes in their functional forms by methanol
Op‐Ed Writing Assignment in Supply Chain Management Courses
Newspaper op‐eds, dedicated to commentary essays from outside of a newspaper, function as a platform for the public to exchange opinions. We designed an op‐ed writing assignment as part of a semester‐long course project in global supply chain management (SCM). Student teams conducted research on a SCM topic, presented their findings in the classroom, and wrote an op‐ed for submission to a local or regional newspaper. This teaching brief describes the implementation of this assignment at a northeast U.S. university. The goals of this assignment were: (1) to educate students on how to write an op‐ed and (2) to educate students on how to publish their opinion articles. Insights on the benefits and challenges that students experienced from completing the op‐ed assignment are discussed. A description of a case‐based version of the op‐ed writing assignment used in a Canadian university is also provided
A pilot study of interactive-video games in people with mild cognitive impairment
Early preventive strategies for improving cognitive function are crucial for people with mild cognitive impairment (MCI). Cognitive training exercises may improve cognitive functioning. However, there was limited evidence from training programs that combined cognitive-specific and physical activities, particularly in using interactive video games as interventions. This study aimed to evaluate the feasibility and effects of the interactive-video games on cognitive function, physical function, mood status and quality of life in community-dwelling people with MCI. A quasi-experimental study was undertaken. Participants in the intervention group received 60 min group-based training program once per week for 12 weeks. A generalised estimating equation (GEE) was used to examine the main effect, interactions and changes in outcomes over time. Sixteen participants completed the trial with eight in the intervention group and eight in the comparison group. The tolerable acceptance rate, perfect attendance rate, high satisfaction with the training content, and no injuries or falls demonstrated the feasibility of this program. The scores of cognitive
function increased in both groups and the interaction between time and groups were significant over 12 weeks of training (p < 0.05). As the result, we determined that interactive-video games can be a safe, feasible, enjoyable intervention and user-friendly among people with MCI in community settings
Ginseng Total Saponins Reverse Corticosterone-Induced Changes in Depression-Like Behavior and Hippocampal Plasticity-Related Proteins by Interfering with GSK-3 β
This study aimed to explore the antidepressant mechanisms of ginseng total saponins (GTS) in the corticosterone-induced mouse depression model. In Experiment 1, GTS (50, 25, and 12.5 mg kg−1 d−1, intragastrically) were given for 3 weeks. In Experiment 2, the same doses of GTS were administrated after each corticosterone (20 mg kg−1 d−1, subcutaneously) injection for 22 days. In both experiments, mice underwent a forced swimming test and a tail suspension test on day 20 and day 21, respectively, and were sacrificed on day 22. Results of Experiment 1 revealed that GTS (50 and 25 mg kg−1 d−1) exhibited antidepressant activity and not statistically altered hippocampal protein levels of brain-derived neurotrophic factor (BDNF) and neurofilament light chain (NF-L). Results of Experiment 2 showed that GTS (50 and 25 mg kg−1 d−1) ameliorated depression-like behavior without normalizing hypercortisolism. The GTS treatments reversed the corticosterone-induced changes in mRNA levels of BDNF and NF-L, and protein levels of BDNF NF-L, phosphor-cAMP response element-binding protein (Ser133), and phosphor-glycogen synthase kinase-3β (Ser9) in the hippocampus. These findings imply that the effect of GTS on corticosterone-induced depression-like behavior may be mediated partly through interfering with hippocampal GSK-3β-CREB signaling pathway and reversing decrease of some plasticity-related proteins
Real-time stability of a hepatitis E vaccine (Hecolin®) demonstrated with potency assays and multifaceted physicochemical methods
The first prophylactic vaccine against hepatitis E virus (HEV), Hecolin®, was licensed in China. Recombinant p239 virus-like particle (VLP) is its active component with dimeric protein as the basic building block harboring the immuno dominant and neutralizing epitopes. The real time and real condition stability of the prefilled syringes for the vaccine was demonstrated using both in vivo mouse potency and in vitro antigenicity assays. A total of 12 lots of Hecolin® were assessed with a set of assays after storage at 2-8 °C for 24 months. The particle characteristics of p239 VLP recovered from the aluminum-containing adjuvant was assessed with different methods including analytical ultracentrifugation, high performance size exclusion chromatography and transmission electron microscopy. The thermal and conformational stability of the adsorbed antigen was assessed using differential scanning calorimetry. The protein integrity of the recovered p239 antigen was demonstrated using SDS-PAGE with silvering staining, LC-MS and MALDI-TOF MS. Most importantly, the binding activity to the neutralizing antibody or vaccine antigenicity was measured using an epitope-specific and real-time SPR assay and a monoclonal antibody-based sandwich ELISA. Taken together, the overall good stability of the Hecolin® prefilled syringes was demonstrated with unaltered molecular and functional attributes after storage at 2-8 °C for 24 months
Tooth loss, denture use, and all-cause and cause-specific mortality in older adults: a community cohort study
ObjectivesThe available evidence on the connections between tooth loss, denture use, and mortality from all causes or specific causes among older adults is inconclusive. Therefore, we aimed to investigate the association between tooth loss, denture use, and all-cause and cause-specific mortality in older adults.MethodsA cohort of 5,403 participants aged 65 and older were recruited in the 2014 Chinese Longitudinal Healthy Longevity Survey wave and followed up in the 2018 wave. Cox proportional hazard models were used to examine the association between the number of natural teeth, denture use, and all-cause and cause-specific mortality.ResultsDuring a mean (SD) follow-up of 3.1 years (1.3), 2,126 deaths (39.3%) occurred. Individuals with 0 and 1–9 teeth had higher mortality due to all-cause, cardiovascular disease (CVD), cancer, and other causes (all p-trend <0.05) than those with 20+ teeth. At the same time, no association was found with respiratory disease mortality. Participants who used dentures had lower mortality due to all causes [hazard ratios (HR) 0.79, 95% confidence intervals (CI) 0.71–0.88], CVD (HR 0.80, 95% CI 0.64–1.00), respiratory disease (HR 0.66, 95% CI 0.48–0.92), and other causes (HR 0.77, 95% CI 0.68–0.88) than those without dentures. Joint analysis revealed that older adults with fewer natural teeth and no dentures had higher mortality. Additionally, interaction analyses showed that the effects of the number of natural teeth on all-cause mortality were more pronounced in older adults aged <80 years (p-value for interaction = 0.03).ConclusionHaving fewer natural teeth, particularly less than 10 teeth, is linked to an increased risk of mortality from all causes, including CVD, cancer, and other causes, but not respiratory disease. The use of dentures would mitigate the adverse impact of tooth loss on all-cause and some cause-specific mortality
Spermidine endows macrophages anti-inflammatory properties by inducing mitochondrial superoxide-dependent AMPK activation, Hif-1α upregulation and autophagy.
Distinct metabolic programs, either energy-consuming anabolism or energy-generating catabolism, were required for different biological functions. Macrophages can adopt different immune phenotypes in response to various cues and exhibit anti- or pro-inflammatory properties relying on catabolic pathways associated with oxidative phosphorylation (OXPHOS) or glycolysis. Spermidine, a natural polyamine, has been reported to regulate inflammation through inducing anti-inflammatory (M2) macrophages. However, the underlying mechanisms remain elusive. We show here that the M2-polarization induced by spermidine is mediated by mitochondrial reactive oxygen species (mtROS). The levels of mitochondrial superoxide and H2O2 were markedly elevated by spermidine. Mechanistically, mtROS were found to activate AMP-activated protein kinase (AMPK), which in turn enhanced mitochondrial function. Furthermore, hypoxia-inducible factor-1α (Hif-1α) was upregulated by the AMPK activation and mtROS and was required for the expression of anti-inflammatory genes and induction of autophagy. Consistent with previous report that autophagy is required for the M2 polarization, we found that the M2 polarization induced by spermidine was also mediated by increased autophagy. The macrophages treated with spermidine in vitro were found to ameliorate Dextran Sulfate Sodium (DSS)-induced inflammatory bowel disease (IBD) in mice. Thus, spermidine can elicit an anti-inflammatory program driven by mtROS-dependent AMPK activation, Hif-1α stabilization and autophagy induction in macrophages. Our studies revealed a critical role of mtROS in shaping macrophages into M2-like phenotype and provided novel information for management of inflammatory disease by spermidine
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