四川盆地北部山区中华蜜蜂活动气象指数构建及应用

基于四川盆地北部山区(简称四川盆北山区)2个地面气象观测站的气象资料和1个中华蜜蜂核心保护区的产量资料以及中华蜜蜂的生态特征和活动规律,分析了区内中华蜜蜂的气候生态适宜性;并以气温、水分、光照、风力和天气状况为影响指标,参考生活气象指数,构建四川盆北山区中华蜜蜂活动气象指数和年景评价分级计算方法。结果表明: 影响研究区中华蜜蜂活动的主要气象因子有气温、空气相对湿度、日照时数、风力和白天降水累计时长,其中,气温和白天降水累计时长是影响中华蜜蜂活动的主要限制性气象因子。通过这5个指标因子的不同取值组合,构建中华蜜蜂活动气象指数并进行分级评价:当指数＞12时,天气条件好,适宜中华蜜蜂活动;当指数为7～12时,天气条件一般,较适宜中华蜜蜂活动;当指数为1～7时,天气条件较差,中华蜜蜂活动明显减少;当指数≤1时,天气条件差,不适宜中华蜜蜂活动或处于越冬期。运用该指数对中山蜂场进行气候评价,多年(4—10月)平均综合气象指数为129.3(评分60.4),总体气象条件良好,“土蜂蜜”单产与年度综合气象指数显著相关,气象年景评价准确率90%。     

黄芪汤对延缓C离子辐射致大鼠肾组织细胞凋亡的影响及相关机制

目的: 探讨黄芪汤抑制¹²C⁶⁺离子辐射脑模型鼠肾组织细胞凋亡的分子保护机制。方法: 50只SPF级Wistar大鼠随机分为正常对照组,单纯辐射模型组,黄芪汤(高、中、低剂量)组。正常对照组和单纯辐射模型组给予等体积生理盐水灌胃10 ml/(kg·d),黄芪汤治疗组分别灌胃给予黄芪汤18、9、4.5 g/(kg·d),连续给药2周。7 d后除正常对照组外,其余各组大鼠脑组织给予4Gy ¹²C⁶⁺离子束单次照射,辐射后第7日处死各组大鼠。HE染色法观察大鼠肾脏的病理形态变化,ELISA法检测大鼠血清IL-6的含量,实时荧光定量PCR法测定大鼠肾脏Bcl-2、Bax和Caspase-3的基因表达,免疫组化法检测大鼠肾脏Bcl-2、Bax、Caspase-3和NF-κB的蛋白表达。结果: 与正常对照组比较,单纯辐射模型组体重和肾脏指数均显著降低,血清IL-6的含量显著升高,肾脏Bcl-2的基因表达和蛋白表达均显著降低,Bax和Caspase-3的基因表达和蛋白表达均显著升高,NF-κB的蛋白表达也显著升高(P＜ 0.01),单纯辐射组肾小球系膜细胞明显增生,肾小管间质血管明显扩张充血,肾小管管腔狭窄、不规则。与单纯辐射模型组相比,黄芪汤高剂量组体重和肾脏指数均明显升高,黄芪汤各干预组肾脏Bcl-2的基因表达和蛋白表达均显著升高(P＜0.05或P＜0.01);而黄芪汤中、高剂量组Bax和Caspase-3的蛋白表达均显著降低,各干预组血清IL-6的含量显著降低,肾脏Bax和Caspase-3的基因表达均显著降低,肾脏NF-κB的蛋白表达显著下降(P＜0.05或P＜0.01),黄芪汤高剂量组可见肾小球系膜细胞增生情况明显改善,肾小管轮廓清晰。结论: 黄芪汤对¹²C⁶⁺离子辐射脑模型鼠的肾损伤具有一定的防护作用,其作用机制可能与调控Bcl-2/NF-κB信号通路有关。     

涌泉根灌下水氮耦合对陕北山地苹果光合特性、产量和水氮利用的影响

以陕北山地7年生‘寒富’苹果树为试验材料,设置3个灌水水平[高水(W₁,85%～100%θ_f,θ_f为田间持水量)、中水(W₂,70%～85%θ_f)、低水(W₃,55%～70%θ_f)]和3个施氮水平[高氮(N₁,600 kg·hm^-2)、中氮(N₂,400 kg·hm^-2)、低氮(N₃,200 kg·hm^-2)],研究涌泉根灌条件下水氮耦合对山地苹果树光合特性、产量和水氮利用的影响。结果表明: 相同灌水条件下,随着施氮量的减少,苹果树叶片的净光合速率(P_n)、蒸腾速率(T_r)、气孔导度(g_s)和瞬时水分利用效率(WUE_i)降低,但胞间CO₂浓度(C_i)增加;相同施氮条件下,随着灌水量的减少,叶片P_n、T_r、g_s和WUE_i降低,而C_i增加。W₁N₁处理的P_n、T_r日均值最大,但与W₁N₁处理相比,W₂N₂处理的WUE_i最大。苹果产量、灌溉水利用效率(IWUE)和氮肥偏生产力(NPFP)受灌水和施氮量的显著影响,W₂N₂处理的产量最高(26761 kg·hm^-2),减小灌水量和增大施氮量使IWUE显著提高,而增大灌水量和降低施氮量使NPFP显著增加。回归分析表明,产量和IWUE同时获得最优解时,灌水量和施氮量组合最接近W₂N₂处理。因此,W₂N₂处理为涌泉根灌条件下陕北山地苹果最佳的水氮组合模式。     

Genetic Analysis of Human Adenovirus Type 7 Strains Circulating in Different Parts of China

To investigate the molecular epidemiology and genetic variation of human adenovirus type 7(HAdV-7) in children with acute respiratory infections(ARI) in China. HAdV-7-positive respiratory samples collected from children with ARI in Beijing, Shijiazhuang, Wenzhou and Guangzhou from 2014–2018 were selected for gene amplification and sequence analysis. Fifty-seven HAdV-7 clinical strains with hexon, penton base and fiber gene sequences were obtained. Meanwhile17 strains were selected randomly from different cities for whole genome sequencing. Phylogenetic and variation analyses were performed based on the obtained sequences, HAdV-7 prototype strain Gomen(AY594255), vaccine strains(AY495969 and AY594256) and representative sequences of strains. The phylogenetic trees constructed based on whole genome sequences, major capsid protein genes(hexon, penton base and fiber) and the early genes(E1, E2, E3 and E4) were not completely consistent. The HAdV-7 strains obtained in this study always clustered with most of the circulating strains worldwide from the 1980 s to the present. Compared with the HAdV-7 prototype strain Gomen(AY594255), some amino acid mutations in loop1 and loop2 of hexon and the RGD loop region of the penton base gene were observed. Recombination analysis showed that partial regions of 55 k Da protein and 100 kDa hexon-assembly associated protein genes among all HAdV-7 strains in this study were from HAdV-16 and HAdV-3, respectively. Our study demonstrated the molecular evolution characteristics of HAdV-7 strains circulating in China and provided basic reference data for the prevention, control and vaccine development of HAdV-7.     

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland

Virologica Sinica - Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral...     

Minor salivary gland mesenchymal stromal cells derived from patients with Sjӧgren's syndrome deploy intact immune plasticity

Background aimsMesenchymal stromal cells (MSCs) provide minor salivary glands (MSGs) with support and niche cells for epithelial glandular tissue. Little is known about resident MSG-derived MSCs (MSG-MSCs) in primary Sj?gren's syndrome (PSS). The authors’ objective is to define the immunobiology of endogenous PSS MSG-MSCs.MethodsUsing culture-adapted MSG-MSCs isolated from consenting PSS subjects (n = 13), the authors performed in vitro interrogation of PSS MSG-MSC immunobiology and global gene expression compared with controls. To this end, the authors performed phenotypic and immune functional analysis of indoleamine 2,3-dioxygenase (IDO), programmed death ligand 1 (PD-L1) and intercellular adhesion marker 1 (ICAM-1) before and after interferon γ (IFNγ) licensing as well as the effect of MSG-MSCs on T-cell proliferation. Considering the female predominance of PSS, the authors also addressed the influence of 17-β-estradiol on estrogen receptor α-positive-related MSC function.ResultsThe authors found that MSG-MSCs deployed normal immune regulatory functionality after IFNγ stimulation, as demonstrated by increased protein-level expression of IDO, PD-L1 and ICAM-1. The authors also found that MSG-MSCs suppressed T-cell proliferation in a dose-dependent manner independent of 17-β-estradiol exposure. Gene ontology and pathway analysis highlighted extracellular matrix deposition as a possible difference between PSS and control MSG-MSCs. MSG-MSCs demonstrated increased α-smooth muscle actin expression in PSS, indicating a partial myofibroblast-like adaptation.ConclusionsThese findings establish similar immune regulatory function of MSG-MSCs in both PSS and control patients, precluding intrinsic MSC immune regulatory defects in PSS. PSS MSG-MSCs show a partial imprinted myofibroblast-like phenotype that may arise in the setting of chronic inflammation, providing a plausible etiology for PSS-related glandular fibrosis.     

Synthesis,telomerase inhibitory and anticancer activity of new 2-phenyl-4H-chromone derivatives containing 1,3,4-oxadiazole moiety

Based on previous studies, 66 2-phenyl-4H-chromone derivatives containing amide and 1,3,4-oxadiazole moieties were prepared as potential telomerase inhibitors. The results showed most of the title compounds exhibited significantly inhibitory activity on telomerase. Among them, some compounds demonstrated the most potent telomerase inhibitory activity (IC₅₀ < 1 µM), which was significantly superior to the staurosporine (IC₅₀ = 6.41 µM). In addition, clear structure–activity relationships were summarised, indicating that the substitution of the methoxy group and the position, type and number of the substituents on the phenyl ring had significant effects on telomerase activity. Among them, compound A33 showed considerable inhibition against telomerase. Flow cytometric analysis showed that compound A33 could arrest MGC-803 cell cycle at G2/M phase and induce apoptosis in a concentration-dependent way. Meanwhile, Western blotting revealed that this compound could reduce the expression of dyskerin, which is a fragment of telomerase.     

Microscale grooves regulate maturation development of hPSC-CMs by the transient receptor potential channels (TRP channels)

The use of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) is limited in drug discovery and cardiac disease mechanism studies due to cell immaturity. Micro-scaled grooves can promote the maturation of cardiomyocytes by aligning them in order, but the mechanism of cardiomyocytes alignment has not been studied. From the level of calcium activity, gene expression and cell morphology, we verified that the W20H5 grooves can effectively promote the maturation of cardiomyocytes. The transient receptor potential channels (TRP channels) also play an important role in the maturation and development of cardiomyocytes. These findings support the engineered hPSC-CMs as a powerful model to study cardiac disease mechanism and partly mimic the myocardial morphological development. The important role of the TRP channels in the maturation and development of myocardium is first revealed.     

Allelopathic effects of switchgrass on redroot pigweed and crabgrass growth

Non-native invasive plant species influence plant community composition and competitively eradicate native species. However, there is doubt regarding how global invasive species increase and explosively interfere with native plants. Invasive plants always have strong allelopathic potential. In this study, allelopathic effects of switchgrass on redroot pigweed and crabgrass growth were investigated by field and laboratory experiments. Within a 0.4-m distance of switchgrass, density and shoot biomass of native species were significantly suppressed in the field, with 95.1% and 93.0% inhibition on density of redroot pigweed and crabgrass and with 99.0% and 97.7% inhibition on shoot biomass, respectively, during the third growing season. Significant inhibitory effects on shoot and root biomass were observed at the 5:5 (switchgrass–native species) proportion in glass bottles, by 41.57% and 51.21% for shoot and root biomass of redroot pigweed and by 33.42% and 56.95% for shoot and root biomass of crabgrass, respectively. Results of a glass bottle experiment showed that shoot and root biomass of redroot pigweed and crabgrass could be significantly inhibited by contact with switchgrass root. Results of a Petri dish experiment showed that aqueous extracts of switchgrass significantly inhibited germination process of both species at high concentrations, with 90.74% and 18.62% inhibition on germination rate and plumule length of redroot pigweed and with 63.59%, 16.38%, and 19.92% inhibition on germination rate, plumule, and radicle lengths of crabgrass, respectively, at the concentration of 0.1 g·mL^?1. This report demonstrated that switchgrass had allelopathic effects on redroot pigweed and crabgrass growth.