Molecular Detection and Complete Genome Sequences of Tomato chlorosis virus Isolates from Infectious Outbreaks in China

Tomato chlorosis virus (ToCV) is a whitefly‐transmitted, phloem‐limited, bipartite Crinivirus. In 2012, severe interveinal symptoms characteristic of ToCV infections were observed in greenhouse tomato plants in the Shandong province of China. High levels of infestation by whiteflies (Bemisia tabaci), which transmit ToCV, were also observed on tomato plants in all the greenhouses investigated. The presence of ToCV was confirmed by specific RT‐PCR either in the sampled plants or in the whiteflies collected from the ventral surface of the leaves of diseased plants. The complete genomic nucleotide sequences (RNA1 and RNA2) of the Shandong isolate of ToCV (ToCV‐SDSG) were determined and analysed. ToCV‐SDSG RNA1 consisted of 8594 nucleotides encompassing four open reading frames (ORFs). ToCV‐SDSG RNA2 consisted of 8242 nucleotides encompassing nine ORFs. Phylogenetic analysis suggests that the Chinese ToCV‐SDSG isolate is most similar to the ToCV‐Florida isolate.     

Evolutionary dynamics of ecological niche in three Rhinogobio fishes from the upper Yangtze River inferred from morphological traits

In the past decades, it has been debated whether ecological niche should be conserved among closely related species (phylogenetic niche conservatism, PNC) or largely divergent (traditional ecological niche theory and ecological speciation) and whether niche specialist and generalist might remain in equilibrium or niche generalist could not appear. In this study, we employed morphological traits to describe ecological niche and test whether different niche dimensions exhibit disparate evolutionary patterns. We conducted our analysis on three Rhinogobio fish species (R. typus, R. cylindricus, and R. ventralis) from the upper Yangtze River, China. Among the 32 measured morphological traits except body length, PCA extracted the first four principal components with their loading scores >1.000. To find the PNC among species, Mantel tests were conducted with the Euclidean distances calculated from the four principal components (representing different niche dimensions) against the pairwise distances calculated from mitochondrial cytochrome b sequence variations. The results showed that the second and the third niche dimension, both related to swimming ability and behavior, exhibited phylogenetic conservatism. Further comparison on niche breadth among these three species revealed that the fourth dimension of R. typus showed the greatest width, indicating that this dimension exhibited niche generalism. In conclusion, our results suggested that different niche dimensions could show different evolutionary dynamic patterns: they may exhibit PNC or not, and some dimensions may evolve generalism.     

Anti-cancer activities of tea epigallocatechin-3-gallate in breast cancer patients under radiotherapy

The purpose of this study was to test the hypothesis that administration of epigallocatechin-3-gallate (EGCG), a polyphenol present in abundance in widely consumed tea, inhibits cell proliferation, invasion, and angiogenesis in breast cancer patients. EGCG in 400 mg capsules was orally administered three times daily to breast cancer patients undergoing treatment with radiotherapy. Parameters related to cell proliferation, invasion, and angiogenesis were analyzed while blood samples were collected at different time points to determine efficacy of the EGCG treatment. Compared to patients who received radiotherapy alone, those given radiotherapy plus EGCG for an extended time period (two to eight weeks) showed significantly lower serum levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and reduced activation of metalloproteinase-9 and metalloproteinase-2 (MMP9/MMP2). Addition of sera obtained from patients treated with combination of radiotherapy and EGCG feeding for 2-8 weeks to in vitro cultures of highly-metastatic human MDA-MB-231 breast cancer cells resulted in the following significant changes: (1) suppression of cell proliferation and invasion; (2) arrest of cell cycles at the G0/G1 phase; (3) reduction of activation of MMP9/MMP2, expressions of Bcl-2/Bax, c-Met receptor, NF-κB, and the phosphorylation of Akt. MDA-MB-231 cells exposed to 5-10 μM EGCG also showed significant augmentation of the apoptosis inducing effects of γ-radiation, concomitant with reduced NF-κB protein level and AKT phosphorylation. These results provide hitherto unreported evidence that EGCG potentiated efficacy of radiotherapy in breast cancer patients, and raise the possibility that this tea polyphenol has potential to be a therapeutic adjuvant against human metastatic breast cancer.     

人羊膜上皮细胞移植及基因治疗帕金森病大鼠

观察人羊膜上皮细胞(human amniotic epithelial cell,HAEC及)人脑源性神经营养因子(brain-derived neurotrophic factor,BDNF基)因修饰的HAEC在帕金森病(Parkinson’sdisease,PD)模型大鼠脑内的长期存活和对旋转行为的治疗效果。用包装BDNFcDNA的慢病毒转染原代HAEC(HAEC/BDNF),HAEC/BDNF与HAEC分别植入6-羟基多巴胺损伤的PD模型大鼠纹状体内,观察动物的旋转行为,用免疫组织化学方法鉴定移植物在体内的存活。结果表明,治疗组PD大鼠的旋转行为改善明显达14周,HAEC/BDNF组能使恢复时间提前。免疫组织化学方法发现移植细胞在14周后仍有少量存活且部分表达BDNF、酪氨酸羟化酶,纹状体内星形胶质细胞增生。实验结果说明,HAEC和BDNF基因修饰的HAEC移植对PD模型大鼠的行为有一定改善,HAEC可以作为一种治疗PD的供体细胞。     

冠层温度和气温的差与冬小麦生长的关系

作物冠层温度与气温的差(简称冠气温差,下同)可指示作物的水分状况,也可作为作物生长环境的一个综合指标。目前,关于冠层气温差指示作物生长的报道尚少,本文就这一问题进行了初步探讨。 1 材料与方法 试验于1987年和1988年在中国科学院北京农业生态系统试验站进行。土壤为壤质褐潮土,有机质含量在15.0g/kg左右,土壤持水量229.0g/ks。麦田按常规方法管理,春季以后浇3—4次水。设充分湿润(相对含     

鲜盾叶薯蓣中原始皂甙的分离与鉴定

从盾叶薯蓣(Dioscorea zingiberensis Wright)新鲜根茎的甲醇提取物分离到薯蓣皂甙元棕榈酸酯(diosgenin palmitate)、β-谷甾醇(β-sitosterol)、纤细皂甙(gracillin)、原纤细皂甙(protogracillin)和原盾叶皂甙(protozingiberemissaponin),后者为一新甾体皂甙,结构推定为3-O-{α-L-鼠李吡喃糖(1→3)-[β-D-葡萄吡喃糖(1→2)]-β-D-葡萄吡喃糖}-26-O-{β-D-葡萄吡喃糖}-薯蓣皂甙元(3-O-{α-L-rhamnopyran0syl(1→3)-[β-D-glucopyranosyl(1→2)]-β-D-glucopyranosyl}-26-O-{β-D-glucopyranosyl}-diosgenin)。     

Indium Iodide Additive Realizing Efficient Mixed Sn─Pb Perovskite Solar Cells

Low-bandgap mixed tin (Sn)-lead (Pb) perovskite solar cells promise efficiency beyond the pure-Pb ones. However, the difference in the interaction rate of SnI₂ and PbI₂ with organic salts causes spatial distribution heterogeneity of Sn²⁺ and Pb²⁺ in mixed Sn─Pb perovskite layers. This causes a Sn-rich surface, which can trigger more severe Sn²⁺ oxidation and nonradiative recombination. A strategy, of introducing indium ion (In³⁺) into the perovskite precursor solution to compete with Sn²⁺ when reacting with organic salts is developed. Therefore, the nucleation and crystallization of perovskite films are well-controlled, leading to improved film quality with a more balanced Sn/Pb ratio on the film surface. Additionally, In³⁺ has a lower reduction potential compared to Sn²⁺ which can generate an extra energy barrier for Sn²⁺ oxidation. The improved film quality and reduced surface oxidation result in accelerated electron transfer and reduced carrier recombination rate. The modified devices achieve a power conversion efficiency (PCE) of 23.34%, representing one of the highest PCEs in mixed Sn─Pb solar cells made with PCBM.     

(3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone: A potent,selective, orally active dipeptidyl peptidase IV inhibitor

A series of 4-substituted proline amides was synthesized and evaluated as inhibitors of dipeptidyl pepdidase IV for the treatment of type 2 diabetes. (3,3-Difluoro-pyrrolidin-1-yl)-[(2S,4S)-(4-(4-pyrimidin-2-yl-piperazin-1-yl)-pyrrolidin-2-yl]-methanone (5) emerged as a potent (IC₅₀ = 13 nM) and selective compound, with high oral bioavailability in preclinical species and low plasma protein binding. Compound 5, PF-00734200, was selected for development as a potential new treatment for type 2 diabetes.