Effect of nitrogen concentration,source, and phosphate concentration on accumulation of biomass and calycosin-7-O-β-D-glucoside in Astragalus membranaceus adventitious roots

In Vitro Cellular & Developmental Biology - Plant - Calycosin-7-O-β-D-glucoside (CG), a methoxylated isoflavonoid in Astragalus membranaceus Fisch. (Bunge), has a wide range of biological...     

Reforestation and surface cooling in temperate zones: Mechanisms and implications

Land‐use/cover change (LUCC) is an important driver of environmental change, occurring at the same time as, and often interacting with, global climate change. Reforestation and deforestation have been critical aspects of LUCC over the past two centuries and are widely studied for their potential to perturb the global carbon cycle. More recently, there has been keen interest in understanding the extent to which reforestation affects terrestrial energy cycling and thus surface temperature directly by altering surface physical properties (e.g., albedo and emissivity) and land–atmosphere energy exchange. The impacts of reforestation on land surface temperature and their mechanisms are relatively well understood in tropical and boreal climates, but the effects of reforestation on warming and/or cooling in temperate zones are less certain. This study is designed to elucidate the biophysical mechanisms that link land cover and surface temperature in temperate ecosystems. To achieve this goal, we used data from six paired eddy‐covariance towers over co‐located forests and grasslands in the temperate eastern United States, where radiation components, latent and sensible heat fluxes, and meteorological conditions were measured. The results show that, at the annual time scale, the surface of the forests is 1–2°C cooler than grasslands, indicating a substantial cooling effect of reforestation. The enhanced latent and sensible heat fluxes of forests have an average cooling effect of ?2.5°C, which offsets the net warming effect (+1.5°C) of albedo warming (+2.3°C) and emissivity cooling effect (?0.8°C) associated with surface properties. Additional daytime cooling over forests is driven by local feedbacks to incoming radiation. We further show that the forest cooling effect is most pronounced when land surface temperature is higher, often exceeding ?5°C. Our results contribute important observational evidence that reforestation in the temperate zone offers opportunities for local climate mitigation and adaptation.     

Some Meaningful Weighted Log-Rank and Weighted Win Loss Statistics

Statistics in Biosciences - Weighted log-rank statistics and recently weighted win loss statistics are often used to test the null hypothesis that the treatment group and the control group have no...     

The effect of intrauterine inflammation on mTOR signaling in mouse fetal brain

Fetuses exposed to an inflammatory environment are predisposed to long‐term adverse neurological outcomes. However, the mechanism by which intrauterine inflammation (IUI) is responsible for abnormal fetal brain development is not fully understood. The mechanistic target of rapamycin (mTOR) signaling pathway is closely associated with fetal brain development. We hypothesized that mTOR signaling might be involved in fetal brain injury and malformation when fetuses are exposed to the IUI environment. A well‐established IUI model was utilized by intrauterine injection of lipopolysaccharide (LPS) to explore the effect of IUI on mTOR signaling in mouse fetal brains. We found that microglia activation in LPS fetal brains was increased, as demonstrated by elevated Iba‐1 protein level and immunofluorescence density. LPS fetal brains also showed reduced neuronal cell counts, decreased cell proliferation demonstrated by low Ki67‐positive density, and elevated neuron apoptosis evidenced by high expression of cleaved Caspase 3. Furthermore, we found that mTOR signaling in LPS fetal brains was elevated at 2 hr after LPS treatment, declined at 6 hr and showed overall inhibition at 24 hr. In summary, our study revealed that LPS‐induced IUI leads to increased activation of microglia cells, neuronal damage, and dynamic alterations in mTOR signaling in the mouse fetal brain. Our findings indicate that abnormal changes in mTOR signaling may underlie the development of future neurological complications in offspring exposed to prenatal IUI.     

Association of myostatin deficiency with collagen related disease-umbilical hernia and tippy toe standing in pigs

Transgenic Research - Herein, we investigate the high incidence of umbilical hernia and tippy-toe standing and their underlying changes in gene expression and proliferation in myostatin knockout...     

基于雪岭云杉树轮宽度重建过去339年天山中部巴音布鲁克地区夏季NDVI

归一化差异植被指数(NDVI)被广泛应用于植被研究的各个领域,但由于观测时长较短,难以满足长时间尺度的研究需要。基于巴音布鲁克地区雪岭云杉建立了树轮宽度年表(STD),计算年表和NDVI同气象观测数据的相关系数。结果表明:树轮宽度指数和NDVI均与同时段的气象数据具有显著相关。结合宽度年表与6—8月NDVI间的显著正相关(r=0.7,P＜0.01,n=38),使用回归模型重建了研究区过去339年的夏季(6—8月)NDVI变化序列,在1680—2018年,重建序列有4个高植被覆盖时段(1738—1765、1786—1798、1964—1973和2000—2018年)和5个低植被覆盖时段(1690—1714、1825—1834、1850—1880、1895—1920和1945—1955年)。重建结果也反映了天山中部水文气候。与周边重建的对比显示,当开都河径流量增加,且研究区处于较为潮湿的环境时,植被覆盖相对较高,反之植被覆盖偏低。重建序列的极值也捕捉了历史文献中一系列自然灾害。混合单粒子拉格朗日综合轨迹模型(HYSPLT)后向轨迹模型和风场分析表明,NDVI异常受到西风带来的降水影响。     

Thermococcus sp.B1001环糊精酶的重组表达及在麦芽七糖制备中的应用

成功构建pET-24a-tscd质粒,实现Thermococcus sp.Strain B1001来源的环糊精酶(TsCDase)在Es-cherichia coli BL21(DE3)中表达.通过热处理和镍柱分离对重组TsCDase进行纯化.酶学性质研究表明,重组TsCDase的比活为1 208.04 U/mg,最适温度为90℃、最适pH值为5.5.重组酶TsCDase在85℃、90℃、95℃条件下的半衰期分别为180、120、30min.酶转化研究表明,以80 g/L β-环糊精为底物,当酶转化温度为90℃、反应pH值为5.5～6.0,加酶量为25 U/g,反应时间为4 h时,麦芽七糖产率为81.19％和85.95％,七糖占产物麦芽寡糖的比例为95.24％和92.92％.本研究结果为工业化制备麦芽七糖奠定良好基础.     

LncRNA-HOTAIR promotes endothelial cell pyroptosis by regulating the miR-22/NLRP3 axis in hyperuricaemia

Long non-coding RNA (lncRNA) plays an important role in the renal inflammatory response caused by hyperuricaemia. However, the underlying molecular mechanisms through which lncRNA is involved in endothelial injury induced by hyperuricaemia remain unclear. In this study, we investigated the regulatory role of lncRNA-HOTAIR in high concentration of uric acid (HUA)–induced renal injury. We established hyperuricaemia mouse model and an in vitro uric acid (UA)–induced human umbilical vein endothelial cell (HUVEC) injury model. In HUA-treated HUVECs and hyperuricaemia mice, we observed increased HOTAIR and decreased miR-22 expression. The expression of pyroptosis-associated protein (NLRP3, Caspase-1, GSDMD-N, GSDMD-FL) was increased. The release of LDH, IL-1β and IL-18 in cell supernatants and the sera of model mice was also increased. The proliferation of HUVECs stimulated by HUA was significantly inhibited, and the number of TUNEL-positive cells in hyperuricaemia mouse kidney was increased. Bioinformatics analysis and luciferase reporter and RIP assays confirmed that HOTAIR promoted NLRP3 inflammasome activation by competitively binding miR-22. In gain- or loss-of-function experiments, we found that HOTAIR and NLRP3 overexpression or miR-22 knock down activated the NLRP3 inflammasome and promoted pyroptosis in HUA-treated HUVECs, while NLRP3 and HOTAIR knockdown or a miR-22 mimic exerted the opposite effects. Furthermore, in vivo experiments validated that HOTAIR knockdown alleviated renal inflammation in hyperuricaemia mice. In conclusion, we demonstrated that in hyperuricaemia, lncRNA-HOTAIR promotes endothelial cell pyroptosis by competitively binding miR-22 to regulate NLRP3 expression.