mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Influence of Coating MgO on Sticking and Functional Mechanism during Fluidized Bed Reduction of Vanadium Titano-magnetite

The vanadium titano-magnetite (VTM) iron ore fines of 110-150 μm in diameter were reduced in a transparent quartz fluidized bed by 70%CO-30%H2 (volume fraction) mixtures. MgO powders served as coating agent to solve sticking problem. Two coating methods were introduced in this experiment: high temperature injection method and briquetting→oxidizing roast→crushing method. According to the experimental results, the minimum effective coating amount of MgO was 0.1 mass%. The metallization ratio (MR) of the product rose from around 58% to above 90% with the above treatments. To investigate the sticking mechanism of fine ore, the morphology evolution was investigated. Instead of iron whiskers, an interlaced fibrous porous surface formed. The ulvospinel (2FeO·TiO_2) in VTM is more difficult to be reduced than FeO according to thermodynamic calculation. XRD results showed that MgO diffused into Fe_2O_3 lattice before forming pleonaste (MgO·Fe_2O_3) during oxidizing roast at 1273 K. The melting point of the pleonaste is 1986 K and that made contribution to prevent the sticking problem.
George Fu Gao: the past and future of Ebola

Newly returned from thefrontline of the battle against Ebola in West Africa, Dr George Fu Gao talked to NSR on this largest Ebola epidemic in history. As Deputy Director-General of the Chinese Center for Disease Control and Prevention (China CDC), an Academician of the Chinese Academy of Sciences and a fellow of the Third World Academy of Sciences (TWAS), Dr Gao has been personally involved in the fight against acute infectious diseases both on the laboratory bench and in the field for many years. Recalling the sight of an Eb ola-infected young man stumbling to his death on the street and observing the continuing climb of patient statistics, he anxiously calls for larger global help to affected countries. The help provided by the world community to West Africa was 'too late and insufficient', and in this age of globalization 'no country can care only for herself alone. In this interview, Dr Gao also reviews the history, progression, and prognosis of the Ebola epidemic, the cause offailure in the early prevention and containment of the disease, the role of government policies and public health systems, and global prospects and strategies for similar acute infectious diseases in the future.
Geobiology comes of age

Interactions between Earth and life in modern environments as well as through time in Earth's history constitute the purview of modern geobiology (Fig. l). This new field has developed as a broad partnership of fields in the earth and atmospheric sciences with biology and in particular its modern growth is an amalgam of geology, geomicrobiology, paleobiology and biogeochemistry. It is rapidly becoming the equal of geophysics and geochemistry as the focus of major disciplines in the earth sciences matures.
Competition of surface reactions of tritium release from irradiated Li_4SiO_4 pebbles

Out-of-pile tritium release experiments were performed on Li_4SiO_4 pebbles produced from lithium hydroxide under various compositions of sweep gas (He, 1.1% H_2/He) and environmental moisture conditions. The experimental results indicate that tritium gas can be released directly from “dry” Li_4SiO_4 under pure He gas. This phenomenon did not happen on “wet” samples, which means that the chemical form of released tritium is sensitive to moisture. Adding H_2 to sweep gas may increase the overall desorption rate of tritium gas through H_2 isotope exchange reaction, which occurs at a lower temperature than those of directly released tritium gas. Yet, the threshold of the H_2 isotope exchange reaction is higher than the desorption reaction of tritiated water. Consequently, the effect of H_2 isotope exchange reaction would reduce significantly on water adsorbed Li_4SiO_4 samples.
冷暖-丰歉-饥荒-农民起义:基于粮食安全的历史气候变化影响在中国社会系统中的传递

从气候变化对个体粮食安全的影响链出发,论文选取中国过去2000年(210 BC~1910AD,对应西汉至清朝)30年分辨率的温度距平,以及10年分辨率的粮食丰歉等级、饥荒指数和农民起义频次等重建序列,统计分析冷暖变化的影响在生产子系统、人口子系统和社会子系统中传递的差异.结果显示:(1) 30年时间单元的冷暖变化与粮食丰歉呈显著正相关(相关系数0.338,P<0.01)、与饥荒呈显著负相关(相关系数-0.301,P<0.05),与农民起义呈显著负相关(-0.277,P<0.05),而饥荒轻重与粮食丰歉、农民起义频次之间的统计相关性很低.(2) 30年暖单元中多出现粮食丰收或常年的年代(86.5%),对应着中度和轻度饥荒年代较多(76%),发生农民起义的年代数占33.3%; 30年冷单元中多粮食歉收和常年的年代(70.7%),对应着中度和重度饥荒的年代较多(77.6%),同时有51.7%的年代发生了农民起义. (3) 23条主要的可能影响传递路径中有13条以“冷”为起点(其中7条传递到农民起义),10条以“暖”为起点(只有3条传递到农民起义),其中具有气候意义的影响传递路径包括:冷→歉收→重度饥荒→多起义、冷→歉收→中度饥荒→多起义,暖→丰收→轻度饥荒→无起义、暖丰收→中度饥荒→无起义、暖→常年→轻度饥荒→无起义、暖→常年→中度饥荒→无起义等.(4)冷暖变化影响的传递是一个错综复杂的过程,其中饥荒是受人类社会调节空间最大的环节,随着社会层次的提升,冷暖变化的影响由直接变为间接、且逐级衰减;冷时段中(100%)有10.4%的年代出现多起农民起义,可能与气候变化影响有关;暖时段中(100%)有47.9%的年代无农民起义出现,可能与气候变化影响有关.
各向同性介质弹性阻抗的张量表示

作为声波阻抗的广义形式,当前地震勘探领域所应用的弹性阻抗描述了在地震纵波非垂直入射的情况下地层对反射纵波的阻抗特征,因此能够反映地层的横波速度信息.但是,根据其理论公式的推导,传统的弹性阻抗实质是反射波的一个衍生标量属性,且存在诸如弱阻抗差、小入射角和相邻地层纵/横波速度比恒定等假设条件.因此在相应的反射系数重构、地震反演与解释过程中不可避免地存在误差.通过分析各向同性弹性介质中速度场与应力场之间的关系,给出了弹性阻抗张量的精确公式表征.弹性阻抗张量能够表示每个应力分量与速度分量间的关系,因此完备地描述了介质的弹性力学特性.文章通过理论模型和实际数据应用证明了导出的弹性阻抗张量表达式较经典的弹性阻抗公式有更高的精度和适用范围.
塔里木河下游荒漠河岸林蒸散规律及其关键控制机制

干旱区内陆河下游荒漠河岸林带蒸散耗水规律及其控制机制是内陆河流域下游水资源管理的重要科学基础. 本研究对塔里木河下游两种典型河岸林群落胡杨群落和柽柳群落的地下水、土壤水和地表蒸散过程进行了连续观测. 结果发现河岸林带生长季的蒸散过程季节趋势受到植被物候期的控制, 非生长季蒸散微弱; 蒸散日过程是大气要素综合影响的结果, 与参考蒸散显著线性相关; 蒸散的空间格局则受到植被叶面积指数的控制, 植被盖度越大, 蒸散量越大; 地下水是地表蒸散的水分来源, 浅层土壤水参与水循环微弱; 胡杨和柽柳蒸散过程特征一致, 但胡杨耗水能力高于柽柳. 进一步分析表明, 植物蒸腾是地表蒸散的主体, 土壤蒸发占地表蒸散的比例很小; 地下水位是控制干旱区荒漠河岸林水循环的关键因素, 它通过影响植物生长和植被盖度来影响荒漠河岸林带地表蒸散过程和蒸散量; 采用地下水位, 而不是土壤含水量定量表达荒漠河岸林水分胁迫过程更为合适. 基于揭示的水分运动和蒸散规律, 系统描绘了一个表达干旱区内陆河下游河岸林带水循环过程控制机制的概化框架, 并描述了一个简单实用, 能满足内陆河水资源管理需要的荒漠河岸林需水量估算模型.
气候系统10万年周期变化的随机动力学模拟

以随机共振理论为基础, 从随机动力学的角度模拟研究了地球气候10万年周期变化的形成机理. 将理想反照率模型与气候系统的地质证据和观测事实相结合, 构建了新的反照率模型; 并将其引入零维能量平衡模式后, 形成了满足双稳条件的非线性系统. 基于这一系统, 模拟研究了同时考虑太阳辐射周期变化和各种随机扰动时的气候系统10万年周期变化情况. 结果表明, 当噪声强度达到一定数值时, 均可产生随机共振现象. 但是这种噪声强度在实际的气候系统中并不存在. 为了解释弱的太阳辐射周期变化强迫产生10万年冰期、间冰期旋回的机制, 除了考虑太阳辐射随机扰动量, 还需要考虑其他非太阳辐射随机扰动量对这一气候变化过程的随机动力学影响. 对同时考虑太阳辐射随机扰动量和非太阳辐射随机扰动量的模拟分析结果表明, 当同时引入适当的、目前观测到的这两类随机扰动量时, 也可以产生随机共振现象, 其中太阳辐射随机扰动的贡献率约为38%, 证明太阳辐射随机扰动对10万年气候周期的形成具有重要作用.
北斗三频相位观测值线性组合模型及特性研究

针对北斗三频观测值, 从线性组合的基本模型出发, 推导了减弱各类误差源的实数组合, 包括无电离层组合、无对流层组合和最小噪声组合. 无电离层组合和无对流层组合可分别用一个平面来表示, 最小噪声组合可用一条直线来表示. 从几何的角度对三者关系进行研究表明: 无电离层组合平面和无对流层组合平面之间的夹角较小, 两者与最小噪声组合线的夹角较大, 其中无对流层组合平面与最小噪声组合线正交. 通过引入巷数、整数电离层数等定义, 对北斗三频整数线性组合的长波长组合以及无电离层整数组合进行了研究, 表明北斗三频整数线性组合的最大波长为146.53 m, 无电离层整数组合的噪声均较大, 噪声最小的组合为(0, 62, 59). 最后基于巷数、电离层放大因子和噪声放大因子三个指标, 从挑选三个独立线性组合的角度, 研究并给出了具有不同特性的最优北斗三频整数线性组合模型. 针对典型的短基线场景和长基线场景选择得到了最优的三个独立线性的组合.
复杂下垫面地表土壤热通量算法改进:以黑河流域为例

地表土壤热通量是地表能量平衡的重要组成部分, 对地表蒸散发的估算至关重要.利用土壤温湿度廓线观测资料基于热扩散方程计算地表土壤热通量, 并通过冻土融化前后土壤液态水含量变化估算土壤含冰量, 分析了土壤含冰量对土壤热通量的影响, 旨在分析黑河流域典型下垫面(高山草地、农田和森林)地表土壤热通量的时空变化特征. 研究结果表明: (1)黑河流域不同下垫面的地表土壤热通量有明显的日变化差异, 日最大值时刻提前净辐射通量几分钟至几小时不等, 这与土壤质地、湿度、热属性和植被覆盖度有关; (2)净辐射通量有显著的季节变化, 一般夏季达最大值, 冬季最小, 地表土壤热通量也有明显的季节变化, 但并不总是与净辐射通量变化保持一致, 春季达最大值, 夏季由于植被覆盖的原因反而降低; (3)地表土壤热通量占净辐射通量的比例因季节及下垫面不同而有差异, 1月份月平均比值分别为: 阿柔25.6%、盈科22.9%和关滩4.3%, 7月份月平均比值分别为: 阿柔2.3%、盈科1.6%和关滩0.3%; (4)冬季考虑了冰的热容量使得土壤热容量增加, 土壤热存储增加, 从而由热扩散方程计算的地表土壤热通量增加, 使得能量平衡闭合率提高了4.3%.
陆地棉基因组测序—开辟棉花育种新篇章

来自中国农业科学院棉花研究所的棉花基因组测序团队,联合北京大学、武汉大学、华大基因、美国农业部南方平原研究中心以及河北农业大学等研究单位,综合利用第二代高通量测序技术并结合bBAC末端大片段测序方法,完成了世界上最重要的棉种陆地棉(AtDt基因组)的全序列测定和组装,结束了棉花没有参考基因组图谱的历史.研究结果已于b2015年4月20日在线发表在Nature bBiotechnology上,这是该团队继2012年发表二倍体雷蒙德氏棉基因组和2014年发表二倍体亚洲棉基因组之后,在棉花基因组学领域的又一重要突破,开启了棉花基因组学研究的新篇章.棉花基因组的解析,对棉花产量和品质形成生物学机制的深入研究、优异基因的选择和利用、高通量基因分型及建立更加有效的育种策略奠定了坚实基础.
华北一次持续性重度雾霾天气的产生、演变与转化特征观测分析

2011年12月1~7日在华北地区发生了一次比较罕见、持续一周左右的低能见度重度雾霾天气, 本文利用气象行业专项“京津地区低能见度雾霾天气监测与预报研究”观测试验资料, 研究分析了此次持续性重度雾霾天气的气溶胶、云凝结核(CCN)、雾滴谱和含水量等微物理特征及大气能见度、边界层垂直结构特征, 探讨了雾霾天气的产生、演变与转化特征及机理. 结果表明, 此次持续一周的雾霾天气过程发生在高压天气系统和静风条件下, 暖平流和辐射降温形成的稳定逆温边界层结构有利于污染气溶胶的积累和雾霾的形成和发展, 尤其是来自南方持续不断的湿平流使雾霾天气得以长时间持续和发展. 整个雾霾天气期间能见度均小于2 km, 最低能见度达到56 m, 液态水含量在10~(-3) g m~(-3)量级, 最大达到0.16 g m~(-3), 气溶胶数浓度均在10000 cm~(-3)以上, 质量浓度范围为50~160 mg m~(-3). 进一步的研究表明, 此次长达一周的雾霾天气发生了三次强弱不同的霾气溶胶积累、霾雾转化和混合及减弱三个主要阶段. 霾气溶胶积累阶段先后有爱根核模和积聚模气溶胶数浓度的积累和增加. 霾向雾转化和混合阶段中, 雾滴凝结释放的潜热和高浓度气溶胶环境使布朗碰并加剧, 导致气溶胶尺度向粒径大的方向转移, 从而提供了大量可形成云凝结核的气溶胶粒子, 促进了雾的爆发性增强, 浓雾过程中气溶胶向CCN活化率可达17%, 而CCN向雾滴的转化效率可高达100%, 此期间雾滴谱具有爆发性拓宽的特征; 冷锋系统过境或辐射加热增强导致了雾霾过程的减弱和消散.
辣木(Moringa oleifera Lam.)的高质量参考基因组

辣木因其具有高蛋白含量和对干旱的适应在许多发展中国家作为多年生的作物广泛种植.本文完成了高质量的辣木基因组草图,组装出预测基因组91.78%的大小,注释出来19465个蛋白质编码基因.此外,本文对辣木基因组和其他一些物种进行了比较基因组分析,验证了辣木的系统发生地位,同时鉴别了辣木的一些物种特异的基因家族和受正选择的基因,这些基因可能帮助进一步鉴别与辣木的高蛋白、快速生长和抗逆相关的基因.这个参考基因组将开拓对辣木的研究,促进应用基因组学手段对辣木的育种和改良.
Casein Kinase 2 Negatively Regulates Abscisic Acid-Activated SnRK2s in the Core Abscisic Acid-Signaling Module

SnRK2 kinases, PP2C phosphatases and the PYR/PYL/RCAR receptors constitute the core abscisic acid (ABA) signaling module that is thought to contain all of the intrinsic properties to self-regulate the hormone signal output. Here we identify Casein Kinase (CK)2 as a novel negative regulator of SnRK2. CK2 phosphorylates a cluster of conserved serines at the ABA box of SnRK2, increasing its binding to PP2C and triggering protein degradation. Consequently, CK2 action has implications on SnRK2 protein levels, as well as kinase activity and its response to abiotic stimuli.
Cyanobacterial flv4-2 Operon-Encoded Proteins Optimize Light Harvesting and Charge Separation in Photosystem II

Photosystem II (PSII) complexes drive the water-splitting reaction necessary to transform sunlight into chemical energy. However, too much light can damage and disrupt PSII. In cyanobacteria, the flv4-2 operon encodes three proteins (Flv2, Flv4, and Sll0218), which safeguard PSII activity under air-level CO_2 and in high light conditions. However, the exact mechanism of action of these proteins has not been clarified yet. We demonstrate that the PSII electron transfer properties are influenced by the flv4-2 operon-encoded proteins. Accelerated secondary charge separation kinetics was observed upon expression/overexpression of the flv4-2 operon. This is likely induced by docking of the Flv2/Flv4 heterodimer in the vicinity of the Q_B pocket of PSII, which, in turn, increases the Q_B redox potential and consequently stabilizes forward electron transfer. The alternative electron transfer route constituted by Flv2/Flv4 sequesters electrons from Q_B~- guaranteeing the dissipation of excess excitation energy in PSII under stressful conditions. In addition, we demonstrate that in the absence of the flv4-2 operon-encoded proteins, about 20% of the phycobilisome antenna becomes detached from the reaction centers, thus decreasing light harvesting. Phycobilisome detachment is a consequence of a decreased relative content of PSII dimers, a feature observed in the absence of the Sll0218 protein.
Microrheological Insights into the Dynamics of Amyloplasts in Root Gravity-Sensing Cells

Gravitropism in plants is key for orienting organs such as the Darwin's description of the opposite growth direction of roots and shoots in his book The Power of Movement in Plants more than 100 years ago (Darwin, 1880). The gravitropic response of an oriented plant is divided into three sequential phases: gravity sensing, signal transmission, and the growth response. As the initial phase of gravitropism, gravity sensing (the conversion of the mechanical stimulus into a biochemical signal) has been intensively studied, but much is still unknown. The statoliths are vital for sense of balance and response to gravity, e.g. in statocytes for invertebrates and in inner ears for vertebrates. The most widely accepted starch-statolith hypothesis proposes that the physical sedimentation of amyloplasts (statoliths in plants) in the direction of gravity in gravity-sensing cells, such as root columella cells and shoot endodermal cells, triggers biochemical signals (Morita, 2010). The physical movement of amyloplasts in gravity-sensing cells is believed to primarily trigger auxin asymmetric distribution, leading to differential growth across the organ during the gravitropic response (Vanneste and Friml, 2009). It has been gradually recognized that the interaction between amyloplasts and the surrounding intracellular components, e.g. the cytoskeleton and vacuole, greatly affects the Brownian diffusion of amyloplasts leading to a complexity in amyloplast movement (Hou et al., 2004; Leitz et al., 2009).
Specific absorbed fractions of electrons and photons for Rad-HUMAN phantom using Monte Carlo method

The specific absorbed fractions (SAF) for self- and cross-irradiation are effective tools for the internal dose estimation of inhalation and ingestion intakes of radionuclides. A set of SAFs of photons and electrons were calculated using the Rad-HUMAN phantom, which is a computational voxel phantom of a Chinese adult female that was created using the color photographic image of the Chinese Visible Human (CVH) data set by the FDS Team. The model can represent most Chinese adult female anatomical characteristics and can be taken as an individual phantom to investigate the difference of internal dose with Caucasians. In this study, the emission of mono-energetic photons and electrons of 10 keV to 4 MeV energy were calculated using the Monte Carlo particle transport calculation code MCNP. Results were compared with the values from ICRP reference and ORNL models. The results showed that SAF from the Rad-HUMAN have similar trends but are larger than those from the other two models. The differences were due to the racial and anatomical differences in organ mass and inter-organ distance. The SAFs based on the Rad-HUMAN phantom provide an accurate and reliable data for internal radiation dose calculations for Chinese females.
Focusing on the Focus: What Else beyond the Master Switches for Polar Cell Growth?

Cell polarity, often associated with polarized cell expansion/growth in plants, describes the uneven distribution of cellular components, such as proteins, nucleic acids, signaling molecules, vesicles, cytoskeletal elements, and organelles, which may ultimately modulate cell shape, structure, and function. Pollen tubes and root hairs are model cell systems for studying the molecular mechanisms underlying sustained tip growth. The formation of intercalated epidermal pavement cells requires excitatory and inhibitory pathways to coordinate cell expansion within single cells and between cells in contact. Strictly controlled cell expansion is linked to asymmetric cell division in zygotes and stomatal lineages, which require integrated processes of pre-mitotic cellular polarization and division asymmetry.While small GTPase ROPs are recognized as fundamental signaling switches for cell polarity in various cellular and developmental processes in plants, the broader molecular machinery underpinning polarity establishment required for asymmetric division remains largely unknown. Here, we review the widely used ROP signaling pathways in cell polar growth and the recently discovered feedback loops with auxin signaling and PIN effluxers. We discuss the conserved phosphorylation and phospholipid signaling mechanisms for regulating uneven distribution of proteins, as well as the potential roles of novel proteins and MAPKs in the polarity establishment related to asymmetric cell division in plants.
The Study of Carbamoyl Phosphate Synthetase 1 Deficiency Sheds Light on the Mechanism for Switching On/Off the Urea Cycle

Carbamoyl phosphate synthetase 1 (CPS1) deficiency (CPS1D) is an inborn error of the urea cycle having autosomal (2q34) recessive inheritance that can cause hyperammonemia and neonatal death or mental retardation. We analyzed the effects on CPS1 activity, kinetic parameters and enzyme stability of missense mutations reported in patients with CPS1 deficiency that map in the 20-kDa C-terminal domain of the enzyme. This domain turns on or off the enzyme depending on whether the essential allosteric activator of CPS1, N-acetyl- L-glutamate (NAG), is bound or is not bound to it. To carry out the present studies, we exploited a novel system that allows the expression in vitro and the purification of human CPS1, thus permitting site-directed mutagenesis. These studies have clarified disease causation by individual mutations, identifying functionally important residues, and revealing that a number of mutations decrease the affinity of the enzyme for NAG. Patients with NAG affinity-decreasing mutations might benefit from NAG site saturation therapy with N-carbamyl-Lglutamate (a registered drug, the analog of NAG). Our results, together with additional present and prior site-directed mutagenesis data for other residues mapping in this domain, suggest an NAG-triggered conformational change in the b4-a4 loop of the C-terminal domain of this enzyme. This change might be an early event in the NAG activation process. Molecular dynamics simulations that were restrained according to the observed effects of the mutations are consistent with this hypothesis, providing further backing for this structurally plausible signaling mechanism by which NAG could trigger urea cycle activation via CPS1.
Oxidative damage and cell signaling transduction in patients of chronic myeloid leukemia

Chronic myeloid leukemia (CML) was the first human malignancy shown to be consistently associated with a chromosomal abnormality, the Philadelphia chromosome. At the gene level, the Philadelphia chromosome is the result of breaks on chromosomes 9 and 22 with a reciprocal translocation of the distal genetic material. This translocation forms the new hybrid BCR-ABL oncogene, an abnormal 8.5-kb RNA that encodes a 210-kDa fusion protein, which, presumably through its increased tyrosine kinase activity, changes normal hematopoietic cells into CML cells [1].
miR-330-3p controls cell proliferation by targeting early growth response 2 in non-small-cell lung cancer

Non-small-cell lung cancer (NSCLC) is one of the most common lung cancers, and microRNAs (miRNAs) have been reported to play essential roles in NSCLC. Recent studies have indicated that miR-330-3p expression is up-regulated in NSCLC samples and in tissues of NSCLC brain metastasis. In this study, up-regulation of miR-330-3p expression was confirmed in NSCLC and 20 NSCLC patient samples. Furthermore, miR-330-3p was over-expressed in NSCLC cell lines A549 and H23, and the promotive function of miR-330-3p was investigated in regulating NSCLC cell proliferation and cell cycle distribution. To identify potential target genes of miR-330-3p in NSCLC, the miRNA target prediction databases were used. Luciferase activity assay and real-time RT-PCR analysis confirmed that miR-330-3p is negatively correlated with the expression of early growth response 2 (EGR2). Moreover, it was also found that EGR2 mRNA contains two potential binding sites for miR-330-3p. Knock-down of EGR2 with siRNA was demonstrated to have a similar effect as the over-expression of miR-330-3p in NSCLC cell lines. Taken together, our results show that EGR2 is a target of miR-330-3p.
Nitric oxide alleviates aluminum-induced oxidative damage through regulating the ascorbateglutathione cycle in roots of wheat

The possible association with nitric oxide (NO) and ascorbate-glutathione (AsA-GSH) cycle in regulating aluminum (Al) tolerance of wheat (Triticum aestivum L.) was investigated using two genotypes with different Al resistance. Exposure to Al inhibited root elongation, and triggered lipid peroxidation and oxidation of AsA to dehydroascorbate and GSH to glutathione disulfide in wheat roots. ExogenousNOsignificantly increased endogenous NO levels, and subsequently alleviated Al-induced inhibition of root elongation and oxidation of AsA and GSH to maintain the redox molecules in the reduced form in both wheat genotypes. Under Al stress, significantly increased activities and gene transcriptional levels of ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase, were observed in the root tips of the Al-tolerant genotype Jian-864. Nitric oxide application enhanced the activity and gene transcriptional level of these enzymes in both wheat genotypes. g-Glutamylcysteine synthetase was not significantly affected by Al or NO, but NO treatments increased the activity of glutathione peroxidase and glutathione S-transferase to a greater extent than the Al-treated wheat seedlings. Proline was significantly decreased by Al, while it was not affected by NO. These results clearly suggest that NO protects wheat root against Al-induced oxidative stress, possibly through its regulation of the AsA-GSH cycle.
Effects of Tungsten and Boron Contents on Crystallization Temperature and Microhardness of Tungsten Based Metallic Glasses

Effects of tungsten and boron contents on the thermal properties and microhardness of W-Fe-B metallic glass system were studied. Thin foils, with thicknesses of 20 and 100 lm, of the alloys were produced by piston and anvil method in an arc furnace. The structures of the foils were investigated by X-ray diffraction. Thermal stabilities of the alloys were examined by using differential scanning calorimetry. 20-lm- thick foils of all the alloys were determined to be fully amorphous, but crystalline phases were detected in the 100-lm-thick foils. It was found that crystallization temperatures of the alloys are between 1060 and 1177 K. Tungsten and boron content increases improve the crystallization temperature and microhardness of the alloys significantly, but deteriorate the glass forming ability of the alloys. It was also observed that for constant Fe content, increasing tungsten content to the level higher than that of boron content does not result in any further improvement in crystallization temperature, but improves glass forming ability significantly. The alloy containing highest total amount of tungsten and boron, W35Fe35B30, has the highest crystallization temperature, 1177 K, and microhardness, 1634 HV.
Influences of the Welding Heat Input and the Repeated Repair Welding on Ti-3Al-2.5V Titanium Alloy

The primary purpose of this study was to determine the effects of gas tungsten arc welding heat input on the high-temperature tensile properties, toughness, and microstructural features of titanium alloy Ti-3Al-2.5V. The secondary objective was to examine the effect of the repeated repair welding on the properties of the alloy. It was also found that the mechanical properties progressively decreased with increasing the repair welding cycles, especially in the case of the weldment after the first welding repair. It was observed that the sizes of the acicular α' and prior β grain boundaries as well as the volume fraction of the acicular α' phases increased with increasing the welding heat input. In addition, the amount and size of the acicular α' phases were found to increase with increasing the repair welding cycles.
运动诱发电位对兔腹主动脉阻断脊髓损伤的预警

研究表明MEP可以直接反映运动传导通路的功能状态,MEP在下肢神经肌肉表面记录到的运动诱发电位可以反映对脊髓缺血敏感的脊髓前角运动神经元的功能状态,本实验设计就是在脊髓血液供应的解剖学代偿机制的基础上,利用左肾动脉下腹主动脉临时夹闭的方法,来建立脊髓缺血动物模型来研究MEP对脊髓缺血性损伤的警报标准的,此方法相当于同时阻断了5个水平的腰动脉对脊髓的供血,与腰动脉建立脊髓可逆性脊髓缺血动物模型比较,本方法的优点是不受腰动脉解剖变异的影响,同时不会产生阻断不同水平腰动脉所需手术的时间间隔;该方法的缺点是阻断腹主动脉会产生下肢神经肌肉缺血等并发症。
甘肃临夏州东乡族人群15个STR基因座遗传多态性

本文使用ID-Plus试剂盒,对中国临夏回族自治州590名东乡族健康无关个体进行15个常染色体STR基因座遗传多态性调查。结果15个基因座共检出158个等位基因,576种基因型,基因频率在0.000 8 ~0.472 0之间,其分布符合Hardy-Weinberg平衡定律(P > 0.05)。H值在0.616 ~ 0.844之间, DP值在0.967 ~ 0.795之间, PIC值在0.560 ~0.850之间。该系统在所调查的人群中具有较好识别能力。
血友病性关节肌肉疾病的康复评定与治疗

血友病是一组X连锁隐性遗传的出血性疾病,由于FⅧ或FⅨ基因突变导致人体内FⅧ或FⅨ水平降低,从而导致出血。根据凝血因子缺乏的种类,将其分为血友病A(也称血友病甲,Ⅷ因子缺乏)、血友病B(也称血友病乙,Ⅸ因子缺乏)。该病患者以自发性关节或肌肉内出血为主要特征,最常见的临床表现包括关节内出血(关节内血肿)、滑膜炎、关节软骨破坏、软骨下和骨质内囊肿、肌肉挫伤和血友病假性肿瘤,长期反复出血可导致关节畸形、肌肉萎缩,甚至终生残疾等并发症,影响患者的生存质量及生存期。但采取及时或预防性措施,如输注所缺乏的凝血因子、防治出血及出血相关性并发症和其他综合关怀治疗等,可使患者获得与正常人相近的生存质量和生存期。
肌电生物反馈配合电刺激改善早期脑卒中偏瘫患者下肢功能的临床观察

目的:探讨使用肌电生物反馈配合电刺激治疗对早期脑卒中偏瘫患者下肢功能的影响。方法:将符合条件的53例脑卒中偏瘫患者分为治疗组28例和对照组25例;两组患者均予常规康复训练,治疗组在此基础上使用肌电生物反馈配合电刺激治疗;以上两组分别于治疗前、后对患者采用踝关节主动活动范围(AROM)、踝关节最大用力背屈时胫前肌体表肌电值(iEMG)和Fugl-Meyer运动功能量表(FMA)评价患侧下肢功能,使用综合痉挛量表(CSS)评价下肢痉挛。结果:治疗4周后,患者的AROM、iEMG、FMA和CCS评分均提高(P< 0.01),但治疗组优于对照组(P< 0.01)。结论:在常规康复训练的基础上使用肌电生物反馈配合电刺激治疗,能更有效地改善早期脑卒中偏瘫患者下肢功能。
中国HIV分子流行病学30年

1981年6月5日,美国疾病预防控制中心《发病率与病死率周报》(MMWR)发表了Gottlied报告洛杉矶5名年轻男同性恋者感染罕见的卡氏肺囊虫肺炎,尽管该报告当时并未引起关注,但该日被定为艾滋病发现日。1982年9月,美国疾病预防控制中心首次正式在MMWR将此病症命名为AIDS。 1983年法国病毒学家Barre-Sinoussi等从1例AIDS患者淋巴结中分离出一种新的人类反转录病毒(LAV);同时,美国病毒学家Gallo等报告他们分离到的新人类反转录病毒(HTLV- Ⅲ)可能是AIDS病原体。1986年国际微生物学会及国际病毒分类学会将这类病毒统一命名为HIV。