长期施肥对红壤旱地作物产量和土壤肥力的影响

历时14年的田间定位试验表明,红壤旱地磷素最为缺乏,施用磷肥对提高作物产量效果最好;施用石灰和微量元素对作物产量没有明显增产作用．施肥可以提高花生植株磷、钾的浓度,表明作物的养分含量受土壤养分供应水平的影响．土壤中赢余(亏损)的养分在养分库重建中的作用可以用速效养分库重建效率来表示．研究表明,当红壤旱地N、P2O5、K2O养分赢余1kg·hm^-2时,可分别使土壤中水解氮、有效磷、交换性钾含量提高0．6～6．26、0．20～0．28和1．1～8．5mg·kg^-1．红壤旱地氮和磷通过径流等损失较大,不同处理之间的变化幅度也较大．红壤每年可固定磷43．5kg·hm^-2,通过自身风化作用每年可提供氮48．1kg·hm^-2和钾40．5kg·hm^-2,以满足作物生长所需．     

The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE)

The Complicate Observations and Multi-Parameter Land Information Constructions on Allied Telemetry Experiment (COMPLICATE) comprises a network of remote sensing experiments designed to enhance the dynamic analysis and modeling of remotely sensed information for complex land surfaces. Two types of experimental campaigns were established under the framework of COMPLICATE. The first was designed for continuous and elaborate experiments. The experimental strategy helps enhance our understanding of the radiative and scattering mechanisms of soil and vegetation and modeling of remotely sensed information for complex land surfaces. To validate the methodologies and models for dynamic analyses of remote sensing for complex land surfaces, the second campaign consisted of simultaneous satellite-borne, airborne, and ground-based experiments. During field campaigns, several continuous and intensive observations were obtained. Measurements were undertaken to answer key scientific issues, as follows: 1) Determine the characteristics of spatial heterogeneity and the radiative and scattering mechanisms of remote sensing on complex land surfaces. 2) Determine the mechanisms of spatial and temporal scale extensions for remote sensing on complex land surfaces. 3) Determine synergist inversion mechanisms for soil and vegetation parameters using multi-mode remote sensing on complex land surfaces. Here, we introduce the background, the objectives, the experimental designs, the observations and measurements, and the overall advances of COMPLICATE. As a result of the implementation of COMLICATE and for the next several years, we expect to contribute to quantitative remote sensing science and Earth observation techniques.     

原子力显微镜研究高乌甲素对人脐静脉内皮细胞形态的影响

在纳米量级上探测药物对人脐静脉内皮细胞(HUVEC)的抑制作用对于揭示药物的功效及肿瘤的有效治疗十分重要.通过高分辨率的原子力显微镜研究了不同浓度的高乌甲素培养的HUVEC的形貌特征,包括整个细胞的形貌和超微结构的表面膜的差异.从形貌学方面探讨了高乌甲素对HUVEC的抑制作用,可为临床应用高乌甲素提供依据.结果表明,我...     

Silica Nanohybrid Membranes with High CO2 Affinity for Green Hydrogen Purification

An effective separation of CO₂ from H₂ can be achieved using currently known polyethylene oxide (PEO)‐based membranes at low temperatures but the CO₂ permeability is inadequate for commerical operations. For commercial‐scale CO₂/H₂ separation, CO₂ permeability of these membranes must be significantly enhanced without compromising CO₂/H₂ selectivity. We report here exceptional CO₂/H₂ separation properties of a nanohybrid membrane comprising polyethylene glycol methacrylate (PEGMA) grafts on an organic‐inorganic membrane (OIM) consisting of a low molecular weight polypropylene oxide (PPO)‐PEO‐PPO diamine and 3‐glycidyloxypropyltrimethoxysilane (GOTMS), an alkoxysilane. The CO₂ gas permeability of this nanohybrid membrane can reach 1990 Barrer with a CO₂/H₂ selectivity of 11 at 35 °C for a mixed gas mixture comprising 50% CO₂ ‐ 50% H₂ at 3.5 atm. The transformation of the inorganic silica phase from a well‐dispersed network of finely defined nanoparticles to rough porous clusters appears to be responsible for this OIM membrane exceeding the performance of other state‐of‐the‐art PEO‐based membranes.     

Regulation of the plasma amino acid profile by leucine via the system L amino acid transporter

Plasma concentrations of amino acids reflect the intracellular amino acid pool in mammals. However, the regulatory mechanism requires clarification. In this study, we examined the effect of leucine administration on plasma amino acid profiles in mice with and without the treatment of 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) or rapamycin as an inhibitor of system L or mammalian target of rapamycin complex 1, respectively. The elevation of plasma leucine concentration after leucine administration was associated with a significant decrease in the plasma concentrations of isoleucine, valine, methionine, phenylalanine, and tyrosine; BCH treatment almost completely blocked the leucine-induced decrease in plasma amino acid concentrations. Rapamycin treatment had much less effects on the actions of leucine than BCH treatment. These results suggest that leucine regulates the plasma concentrations of branched-chain amino acids, methionine, phenylalanine, and tyrosine, and that system L amino acid transporters are involved in the leucine action.     

The Tim-3 ligand galectin-9 negatively regulates CD8+ alloreactive T cell and prolongs survival of skin graft

CD8+ alloreactive T cells are the key mediators of accelerated rejection. Vigorous CD8+ alloreactive T cells responses against alloantigens, which is the main effector mechanism in acute allograft rejection, has been well described. But the molecular mechanisms to dampen activated CD8+ T cells are largely unknown. On the other hand, Tim-3 is a molecule expressed on terminally differentiated CD4+ Th1 cells. Engaging Tim-3 with its ligand galectin-9 causes an inhibitory signal, resulting in apoptosis of Th1 cells and negatively regulates Th1 type immunity. However, the question whether CD8+ T cells express surface molecular Tim-3 has not been fully elucidated. In this study, we have investigated which CD8+ subset express molecular Tim-3 by flow cytometric assay. In addition, cytotoxic assay was applied to analyze whether CD8+ alloreactive T cells were sensitive to galectin-9 induced apoptosis. Here, our results demonstrated that Tim-3 was expressed on activated CD8+ alloreactive T cells (CD8+CD44highCD62Llow), but not expressed on na?ve CD8+ T cells. Furthermore, alloreactive CD8+ cytotoxic T cells were sensitive to galectin-9 induced apoptosis both in vitro and vivo, resulting in attenuation of CD8+ alloreactive T cells mediated cytotoxicity and prolonged survival of skin graft.