干旱区植物叶片大小对叶表面蒸腾及叶温的影响

利用热及物质交换原理, 并结合前人研究成果, 在单叶尺度上建立了简单的叶温和水气蒸腾模型。模型通过预设值驱动, 预设值参照干旱区环境及植物叶片特征设置。模拟结果显示: 随气孔阻力的增加, 叶片蒸腾速率降低, 叶温升高; 同一环境下, 具有低辐射吸收率的叶片蒸腾速率和叶温更低, 并且气孔阻力越大, 这种差异越明显。另外, 叶片宽度及风速是影响叶片蒸腾及叶温的重要因子。干旱地区植物生长季节, 风速小于0.1 m·s ^-1、气孔阻力接近1000 s·m ^-1时, 降低叶片宽度不仅有利于降低叶片温度, 而且能够降低叶片蒸腾速率, 从而实现保持水分, 增强植物适应高温、干旱的能力。     

不同种植行距的大穗型小麦品种'兰考矮早八'中几种与旗叶衰老有关的生理指标变化

在大田高产栽培条件下,检测不同种植行距的大穗型小麦品种‘兰考矮早八’开花后与旗叶衰老相关生理指标以及产量性状的结果表明,相对于传统行距为20cm而言,‘兰考矮早八’种植行距缩至15cm的花后旗叶中叶绿素降解减慢,丙二醛（MDA）含量下降,抗氧化系统酶活性增强,功能叶衰老减缓,穗粒重提高;行距缩至10cm时,尽管灌浆中后期过氧化物歧化酶（SOD）活性增强,但过氧化氢酶（CAT）和过氧化物酶（POD）活性下降,花后旗叶中叶绿素降解加快,MDA含量升高,植株衰老加快,穗粒重下降。     

斑马鱼socs2的TALEN敲除及其敲除胚胎的生长研究

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Modeling K(m) values using electrotopological state: substrates for cytochrome P450 3A4-mediated metabolism

In order to determine K(m) values of substrates for CYP3A4-mediated metabolism, an in silico model has been developed in the present work. Using electrotopological state (E-state) indices, together with Bayesian-regularized neural network (BRNN), we have described an in silico method to model log(1/K(m)) values of various substrates. The relative importance of the E-state indices is analyzed by principal component analysis. By using an additional external test set, which is independent of the training set, the robustness and predictivity of the model are also validated.     

Effects of leaf shape plasticity on leaf surface temperature北大核心CSCD

Aims The shape plasticity of plant leaves is an important survival strategy to high temperature and drought in arid region, yet reliable evidences are insufficient to validate the fundamental concepts. Our objective was to demonstrate the specific effects of leaf morphology on leaf surface temperature. Methods Infrared thermal images were processed to determine the leaf temperature and shape parameters of simulated and actual leaf shape. Microclimatic conditions were recorded using a automatic weather station near the sampling plot, including wind speed, radiation and air temperature. Important findings Under the drought and high temperature, the plasticity of leaf shape appeared an important measure to regulate leaf temperature, except leaf transpiration. The exchange rates of matter and energy between leaves and the environment were enhanced by smaller leaves that effectively decreased leaf temperature. With low wind speed and high temperature, leaf surface temperature decreased 2.1 °C per 1 cm reduction in leaf width. However, leaf surface temperature of a simulated leaf decreased 0.60–0.86 °C per 1 cm reduction in leaf width. Results from this study will help us to understand plant adaptability and survival strategy in arid region. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

Efficacy and safety of mesenchymal stromal cell treatment from related donors for patients with refractory aplastic anemia

Background aimsThis study evaluated the feasibility, safety and immunological effects of the intravenous administration of mesenchymal stromal cells (MSCs) from a related donor in patients with refractory aplastic anemia (AA).MethodsA mean of 6 × 10⁵/kg (range, 5.0–7.1 × 10⁵) MSCs were injected intravenously to 18 patients, including 14 patients with nonsevere AA and four patients with severe AA who were refractory to prior immunosuppressive treatment. The outcomes of patients treated with MSCs were evaluated and compared with a historic control cohort, including 18 patients with refractory AA.ResultsTwo patients had injection-related adverse events, including transient fever and headache. No major adverse events were reported during the follow-up period. An immunological analysis revealed an increased proportion of CD4⁺CD25⁺ FOXP3⁺regulatory T cells in peripheral mononuclear cells. Following up for 1 year, six of 18 patients (33.3%) achieved a complete response or a partial response to MSC treatment. In six patients, two achieved a complete response including a recovery of three hematopoietic cell lines after MSCs therapy at days 88 and 92, two patients achieved only a red cell recovery with hemoglobin levels >100 g/L at days 30 and 48 and two patients had only a platelet recovery with a platelet count of >60 × 10⁹/L at days 54 and 81. In the control cohort, only one patient (5.56%) achieved a partial response during the follow-up period.ConclusionsThe data from the present study suggest that treatment with MSCs from a related donor may be a promising therapeutic strategy for patients with refractory AA. The trial has been registered at ClinicalTrials.gov: identifier NCT01305694.     

Synthesis,biological evaluation,and molecular docking studies of novel 1,3,4-oxadiazole derivatives possessing benzotriazole moiety as FAK inhibitors with anticancer activity

1,3,4-Oxadiazole derivatives have drawn continuing interest over the years because of their varied biological activities. In order to search for novel anticancer agents, we designed and synthesized a series of new 1,3,4-oxadiazole derivatives containing benzotriazole moiety as potential focal adhesion kinase (FAK) inhibitors. All the synthesized compounds were firstly reported. Among the compounds, compound 4 shows the most potent inhibitory activity against MCF-7 and HT29 cell lines with IC₅₀ values of 5.68 μg/ml and 10.21 μg/ml, respectively. Besides, all the compounds were assayed for FAK inhibitory activity using the TRAP–PCR–ELISA assay. The results showed compound 4 exhibited the most potent FAK inhibitory activity with IC₅₀ values of 1.2 ± 0.3 μM. Docking simulation by positioning compound 4 into the FAK structure active site was performed to explore the possible binding mode. Apoptosis which was analyzed by flow cytometry, demonstrated that compound 4 induced apoptosis against MCF-7 cells. Therefore, compound 4 may be a potential anticancer agent against MCF-7 cancer cell.     

A molecular isolation mechanism associated with high intra-specific diversity in rice

High levels of inter-specific diversity are expected due to genetic isolation, the reproductive or geographical barriers, which lead to the accumulation of nucleotide variation. However, high levels of genetic variation are repeatedly observed even within species, notably at loci of the human major histocompatability complex and of plant resistance genes. Are molecular isolations responsible for the high intra-specific variation? To address this issue, we performed a genome-wide survey of the relationship between the possible factors that could cause genetic isolation, and the level of polymorphism, based on two rice genome comparisons. Here, we show that the levels of polymorphism in rice genes are positively correlated with the proportions of non-alignable flanking sequences, and that the correlation is observed even in single-copy genes. The physical locations of the genes were also investigated, and a strong association between the asymmetric architecture of genomes and the levels of polymorphism was revealed. These results suggest that the flank heterogeneity and the asymmetric architecture between genomes serve as isolation mechanisms at the molecular level that result in accumulation of higher genetic variation. This mechanism is of fundamental importance to understand natural genetic variation within species.