Locomotive implication of a Pliocene three-toed horse skeleton from Tibet and its paleo-altimetry significance

The Tibetan Plateau is the youngest and highest plateau on Earth, and its elevation reaches one-third of the height of the troposphere, with profound dynamic and thermal effects on atmospheric circulation and climate. The uplift of the Tibetan Plateau was an important factor of global climate change during the late Cenozoic and strongly influenced the development of the Asian monsoon system. However, there have been heated debates about the history and process of Tibetan Plateau uplift, especially the paleo-altimetry in different geological ages. Here we report a well-preserved skeleton of a 4.6 million-y-old three-toed horse (Hipparion zandaense) from the Zanda Basin, southwestern Tibet. Morphological features indicate that H. zandaense was a cursorial horse that lived in alpine steppe habitats. Because this open landscape would be situated above the timberline on the steep southern margin of the Tibetan Plateau, the elevation of the Zanda Basin at 4.6 Ma was estimated to be ～4,000 m above sea level using an adjustment to the paleo-temperature in the middle Pliocene, as well as comparison with modern vegetation vertical zones. Thus, we conclude that the southwestern Tibetan Plateau achieved the present-day elevation in the mid-Pliocene.     

2011—2020年内蒙古自治区肺结核疫情监测分析

分析2011—2020年内蒙古自治区肺结核流行病学特征,为全区制定肺结核防治策略提供科学依据。方法:收集2011年1月1日至2020年12月31日内蒙古自治区在中国疾病预防控制中心“全国传染病报告信息管理系统”中登记的肺结核患者相关信息。采用描述性流行病学方法,对内蒙古自治区肺结核疫情流行病学特征进行分析。结果:201...     

奶牛乳腺炎无乳链球菌临床分离株fbsA基因的克隆与序列分析

目的克隆并分析牛乳腺炎无乳链球菌内蒙古地区临床分离株表面蛋白fbsA基因核苷酸及编码氨基酸序列,预测其潜在的抗原表位。方法以无乳链球菌内蒙古地区临床分离株为材料,根据GenBank中公布的无乳链球菌fbsA基因序列设计特异性克隆引物,采用同源克隆法,PCR扩增fbsA基因序列,采用DNA Star生物信息学软件预测分析其编码氨基酸的潜在抗原性。结果克隆的fbsA基因序列大小为321bp,编码107个氨基酸残基,与GenBank中公布的B群无乳链球菌fbsA基因核苷酸序列同源性为98.13%,氨基酸序列同源性为99%。预测克隆基因编码氨基酸抗原性指数良好。结论成功克隆出内蒙古地区奶牛乳腺炎无乳链球菌表面蛋白fbsA基因序列,并预测其编码氨基酸具有潜在抗原性为进一步研究其原核表达产物的抗原性及致病机制奠定了基础。     

2006-2008年内蒙古克山病治疗管理干预效果分析

目的 对慢型克山病患者实施健康管理及药物治疗干预,观察和分析干预效果.方法 在内蒙古克山病病区选择一定数量的慢型克山病患者进行治疗管理干预,包括以治疗慢性充血性心力衰竭为主的药物干预,以健康教育并指导生活方式为主的管理干预.2006-2008年共进行3次干预,每次为期6个月.以干预对象干预初期,末期心电图诊断结果、心胸比例结果、心功能分级结果、克山病类型、劳动能力为判定指标,以其中一项指标改善即为干预有效,统计有效人数及有效率,观察干预次数和不同用药对干预结果的影响.结果 345人参与治疗管理干预,207人有效,有效率为60%(207/345).其中180人参与1次干预,有效率为44%(79/180);91人参与2次干预,有效率为66%(60/91);74人参与3次干预,有效率为92%(68/74).不同干预次数有效率比较差异有统计学意义(χ2=52.16,P<0.01);其中干预3次高于干预2次及干预1次(χ2值分别为15.81、49.56,P均<0.0125),干预2次高于干预1次(χ2=11.76,P<0.0125),有效率随干预次数增多而增加.不同药物组间有效率比较差异有统计学意义(χ2=19.56,P<0.01);其中血管紧张素转化酶抑制剂(ACEI)组有效率最高,为77%(82/106),强心药组有效率为50%(47/94)以及心肌能量药组有效率为54%(78/145),ACEI组药物治疗干预有效率高于强心药组和心肌能量药组(χ2值分别为16.28、14.71,P均<0.0125).结论 对克山病患者进行健康管理及药物治疗干预,对改善患者健康状况有意义.加强健康教育,指导正确生活方式以及用ACEI、β受体阻滞剂、利尿剂联合治疗慢型克山病充血性心力衰竭,对改善患者健康状况效果更明显.     

内蒙古乌兰察布地区布鲁氏菌体外药物敏感性及耐药机制分析

目的 调查内蒙古乌兰察布地区分离布鲁氏菌的抗生素药物敏感(耐受)性特征。方法 采用E-test法测定了85株布鲁氏菌对13种临床常用药物的敏感性;同时,对利福平和阿奇霉素的耐药机制进行了初步探讨;并采用K-B法对来自全国的149株羊种布鲁氏菌对复方新诺明和利福平的敏感性进行了筛查。结果 试验表明布鲁氏菌对阿奇霉素、复方新诺明和利福平耐药菌株数分别为100%(85/85),7.0% (6/85)和 1.0% (1/85)。所有菌株对司帕沙星、米诺环素、多西环素、四环素、链霉素、庆大霉素、左氧氟沙星、环丙沙星、头孢吡肟及头孢哌酮舒巴坦均表现为敏感;司帕沙星、米诺环素的MIC₉₀值(0.032 μg/mL)最低。所有阿奇霉素耐药菌株的23S rRNA基因的第2632位碱基表现为T→C单位点突变,布鲁氏菌23S rRNA转肽酶中心的T/C点突变可能是一种羊种布鲁氏菌对阿奇霉素耐药的分子机制。K-B法筛查结果表明所有菌株对利福平敏感,25.5%(38/149)的菌株对复方新诺明耐药,耐药菌株分布于18个省市区。结论 乌兰察布地区羊种布鲁氏菌耐药较为严重,应定期进行药物敏感性监测。推荐司帕沙星和米诺环素作为一线布病治疗药物。     

内蒙古部分炭疽杆菌16S和23S rRNA基因间段分析

为了解在内蒙古分离的炭疽杆菌与其它地区的菌株之间有无差异,采用ＰＣＲ加酶切的方法对拨和的被试菌进行了１６Ｓ和２３Ｓ ｒＲＮＡ基因间段分析。结果发现所有实验菌株间的ＰＣＲ及酶切图谱一致,说明我区的炭疽杆菌与其它地区的菌株在遗传学上具有同源性,无本质差异。     

内蒙古自治区结核分枝杆菌Spoligotyping分型及北京家族分析

目的 了解内蒙古自治区结核分枝杆菌临床分离株的基因型构成,及该地区北京家族菌株的分布特征。 方法 从内蒙古自治区结核病防治研究所收集2011年全年临床分离的372株结核分枝杆菌菌株及其372例来源患者的背景资料,采用间隔区寡核苷酸分型（Spoligotyping）方法和BioNumerics 5.0软件进行基因分型分析,将372株临床菌株Spoligotyping分型结果与SpolDB 4.0数据库进行比对。另外,采用NTF及LSP 对北京家族菌株进行分析。来源患者中汉族和蒙古族分别为282例及84例,其他为回族4例,维吾尔族和满族各1例,例数过少,因此仅分析主要民族与北京家族的易感性。以SPSS 13.0 软件进行统计学分析,χ²检验分析不同民族与北京家族易感性。 结果372株临床菌株共分为48种基因型,其中24种基因型为新的型别。85.48%（318/372）为北京家族,同时存在T家族（仅次于北京家族的主要流行基因型）占4.84% （18/372）、H家族（Haarlem）0.81%（3/372）、MANU家族(2004年最先于印度Delhi发现)0.27%（1/372）和LAM家族（Latin American and Mediterranean,拉丁美洲和地中海家族）0.27%（1/372）。汉族北京家族菌株占87.94%(248/282),非北京家族菌株占12.06% (34/282),蒙古族北京家族菌株79.76%(67/84),非北京家族菌株20.24% (17/84),差异无统计学意义（χ²=3.612, P=0.057）。 结论 内蒙古自治区结核分枝杆菌临床分离株基因具有多态性,且北京基因型为该地区主要流行株,而北京家族菌株与民族易感性间无关联。     

内蒙古砷中毒病区与台湾乌脚病病区饮水腐植酸的红外光谱对比研究

使用ＸＡＤ－７大孔树指提取内蒙砷中毒地区和台湾乌脚病区饮水中的腐植酸样品，经红外光谱测定发现，内蒙砷病区饮水中腐植酸以富啡酸（ＦＡ）为主，台湾乌脚病区饮水中以胡敏酸（ＨＡ）为主。这种差别对居民健康和疾病的影响有待进一步研究。     

Synthesis and Characterization of Single-Phase α-Cordierite Glass-Ceramics for LTCC Substrates from Tuff

Single-phase α-cordierite glass-ceramics for a low-temperature co-fired ceramic (LTCC) substrate were fabricated from tuff as the main raw material, using the non-stoichiometric formula of α-cordierite with excess MgO without adding any sintering additives. The sintering/crystallization behavior and the various performances of dielectric properties, thermal expansion, and flexural strength of the glass-ceramics were detected. The results indicated that only single-phase α-cordierite crystal was precipitated from the basic glass sintered at the range 875–950 °C, and μ-cordierite crystal was not observed during the whole sintering-crystallization process. The properties of glass-ceramics were first improved and then deteriorated with the increase in tuff content and sintering temperature. Fortunately, the glass-ceramics sintered at 900 °C with 45 wt.% tuff content possessed excellent properties: high densify (2.62 g∙cm⁻³), applicable flexural strength (136 MPa), low dielectric loss (0.010, at 10 MHz), low dielectric constant (5.12, at 10 MHz, close to α-cordierite), and suitable coefficients of thermal expansion (CTE, 3.89 × 10⁻⁶ K⁻¹).     

Crystal structure of cryptochrome 3 from Arabidopsis thaliana and its implications for photolyase activity

Cryptochromes use near-UV/blue light to regulate a variety of growth and adaptive process. Recent biochemical studies demonstrate that the Cryptochrome-Drosophila, Arabidopsis, Synechocystis, Human (Cry-DASH) subfamily of cryptochromes have photolyase activity exclusively for single-stranded cyclobutane pyrimidine dimer (CPD)-containing DNA substrate [Selby C, Sancar A (2006) Proc Natl Acad Sci USA 103:17696-17700]. The crystal structure of cryptochrome 3 from Arabidopsis thaliana (At-Cry3), a member of the Cry-DASH proteins, at 2.1 A resolution, reveals that both the light-harvesting cofactor 5,10-methenyl-tetrahydrofolyl-polyglutamate (MTHF) and the catalytic cofactor flavin adenine dinucleotide (FAD) are noncovalently bound to the protein. The residues responsible for binding of MTHF in At-Cry3 are not conserved in Escherichia coli photolyase but are strongly conserved in the Cry-DASH subfamily of cryptochromes. The distance and orientation between MTHF and flavin adenine dinucleotide in At-Cry3 is similar to that of E. coli photolyase, in conjunction with the presence of electron transfer chain, suggesting the conservation of redox activity in At-Cry3. Two amino acid substitutions and the penetration of three charged side chains into the CPD-binding cavity in At-Cry3 alter the hydrophobic environment that is accommodating the hydrophobic sugar ring and thymine base moieties in class I CPD photolyases. These changes most likely make CPD binding less energetically favorable and, hence, insufficient to compete with pairing and stacking interactions between the CPD and the duplex DNA substrate. Thus, Cry-DASH subfamily proteins may be unable to stabilize CPD flipped out from the duplex DNA substrate but may be able to preserve the DNA repair activity toward single-stranded CPD-containing DNA substrate.     

Microfluidics of cytoplasmic streaming and its implications for intracellular transport

Found in many large eukaryotic cells, particularly in plants, cytoplasmic streaming is the circulation of their contents driven by fluid entrainment from particles carried by molecular motors at the cell periphery. In the more than two centuries since its discovery, streaming has frequently been conjectured to aid in transport and mixing of molecular species in the cytoplasm and, by implication, in cellular homeostasis, yet no theoretical analysis has been presented to quantify these processes. We show by a solution to the coupled dynamics of fluid flow and diffusion appropriate to the archetypal "rotational streaming" of algal species such as Chara and Nitella that internal mixing and the transient dynamical response to changing external conditions can indeed be enhanced by streaming, but to an extent that depends strongly on the pitch of the helical flow. The possibility that this may have a developmental consequence is illustrated by the coincidence of the exponential growth phase of Nitella and the point of maximum enhancement of those processes.     

Transphosphatidylation of sugar alcohols and its implications for the pathogenesis of diabetic complications

Summary Glucose-induced sorbitol accumulation and attendant alterations in cellular myo-inositol and phosphoinositide metabolism have been invoked in the pathogenesis of diabetic complications; however, direct effects of sorbitol on membrane phospholipid composition or metabolism have never been evaluated. Phospholipase D catalyses the transphosphatidylation of ethanol into phosphatidylcholine to yield phosphatidylethanol, an abnormal phospholipid whose content in rat brain is increased by chronic ethanol ingestion. Analogous transphosphatidylation of sorbitol or other polyols whose concentration is elevated in diabetes was explored in vitro and in glucose-exposed cultured human retinal pigment epithelial cells. Phosphatidylcholine and varying concentrations of sorbitol, galactitol, mannitol and glucose were incubated with peanut phospholipase D in sodium acetate buffer for varying time periods. Thin layer chromatography revealed new phospholipid bands whose hydrolysis by phospholipase D liberated a water-soluble compound that cochromatographed with sorbitol on gas-liquid chromatography, and whose concentration increased in a time- and concentration-dependent fashion. Identical transphosphatidylation activity was demonstrated in a rat brain synaptosomal fraction. Phospholipase D hydrolysis of lipids from human retinal pigment epithelial cells constitutively overexpressing the aldose reductase gene yielded a sorbitol-like compound whose appearance was increased by glucose exposure and was decreased by an aldose reductase inhibitor. Thus, glucose-induced aldose reductase inhibitor sensitive sorbitol accumulation might induce the formation of phosphatidylsorbitol through a transphosphatidyl mechanism that may contribute to altered membrane phospholipid metabolism in diabetes.Abbreviations PL-D Phospholipase D - MEM minimum essential medium - RPE retinal pigment epithelial cells - CS calf serum     

The composition of normal pericardial fluid and its implications for diagnosing pericardial effusions

BACKGROUND: Pericardial fluid obtained at pericardiocentesis is often subjected to biochemical and hematological analysis, and interpreted using criteria borrowed from pleural effusions. However, the validity and diagnostic yield of this approach is uncertain. Moreover, there is little data regarding the normal composition of the physiological pericardial fluid, which could serve as a reference for pathological effusions. METHODS: Pericardial fluid from 30 patients undergoing elective open heart surgery was collected. Patients were excluded if they had known pericardial disease, had systemic disorders known to be associated with pericardial disease, or if the fluid samples were hemolytic. The biochemical and hematological parameters of the fluid were determined using standard laboratory techniques, and compared with the results obtained for concurrently drawn venous blood. RESULTS: The median age of the study population was 64.5 +/- 10.6 years. Chemistry results of soluble molecules were consistent with the plasma ultrafiltrate nature of the fluid. However, fluid lactate dehydrogenase (LDH) level was unexpectedly high, averaging 2.4 times the serum level, and the mean protein level was 0.6 of the serum level. No correlation was found between comorbidities of patients and fluid characteristics. Fluids contained an average of 1430 leukocytes/muL, with a differential count that was predominated by lymphocytes (53.2 +/- 14%) and monocytes (11.6 +/- 6%). CONCLUSIONS: The composition of the physiologic pericardial fluid is remarkable for high LDH and protein content, and for predominance of lymphocytes. Thus, the biochemical criteria useful for diagnosing pleural effusions are probably not applicable for differentiating transudative from exudative pericardial effusions, and lymphocytosis should be interpreted cautiously.     

Solution structure of eggcase silk protein and its implications for silk fiber formation

Spider silks are renowned for their excellent mechanical properties and biomimetic and industrial potentials. They are formed from the natural refolding of water-soluble fibroins with α-helical and random coil structures in silk glands into insoluble fibers with mainly β-structures. The structures of the fibroins at atomic resolution and silk formation mechanism remain largely unknown. Here, we report the 3D structures of individual domains of a ≈366-kDa eggcase silk protein that consists of 20 identical type 1 repetitive domains, one type 2 repetitive domain, and conserved nonrepetitive N- and C-terminal domains. The structures of the individual domains in solution were determined by using NMR techniques. The domain interactions were investigated by NMR and dynamic light-scattering techniques. The formation of micelles and macroscopic fibers from the domains was examined by electron microscopy. We find that either of the terminal domains covalently linked with at least one repetitive domain spontaneously forms micelle-like structures and can be further transformed into fibers at ≥37 °C and a protein concentration of >0.1 wt%. Our biophysical and biochemical experiments indicate that the less hydrophilic terminal domains initiate the assembly of the proteins and form the outer layer of the micelles whereas the more hydrophilic repetitive domains are embedded inside to ensure the formation of the micelle-like structures that are the essential intermediates in silk formation. Our results establish the roles of individual silk protein domains in fiber formation and provide the basis for designing miniature fibroins for producing artificial silks.     

钢铁厂男性工人高血压及其危险因素综合性干预效果的初步评价

目的评价在工厂人群中采取综合性措施干预高血压及其危险因素的效果；初步总结开展人群高血压预防和治疗的经验。方法对干预厂（组）进行为期３年（１９９２年１月至１９９５年４月）设对照厂（组）的综合性干预，对比两厂干预前后２次整群随机抽样调查结果。结果干预后干预组人群年龄调整的收缩压水平、体重指数、高血压患病率和饮酒率较对照组人群分别净下降２．４ｍｍＨｇ、０．４３ｋｇ／ｍ２、５．２％和１９．２％，除患病率外均达统计学显著水平（Ｐ均＜０．０１）；干预组较对照组高血压患者治疗和控制百分率、药物治疗控制在正常高限血压及以下和临界高血压及以下者均明显增加（Ｐ均＜０．０１）；８７例轻度高血压非药物治疗中５１．７％控制在正常高限血压及以下水平。结论采用卫生教育、健康促进及药物和非药物综合干预方法，对男性工厂人群高血压及其危险因素的预防和控制具有较好的效果；专业人员与基层保健人员密切合作对开展高血压预防和控制具有重要作用。     

Environmental transmission of low pathogenicity avian influenza viruses and its implications for pathogen invasion

Understanding the transmission dynamics and persistence of avian influenza viruses (AIVs) in the wild is an important scientific and public health challenge because this system represents both a reservoir for recombination and a source of novel, potentially human-pathogenic strains. The current paradigm locates all important transmission events on the nearly direct fecal/oral bird-to-bird pathway. In this article, on the basis of overlooked evidence, we propose that an environmental virus reservoir gives rise to indirect transmission. This transmission mode could play an important epidemiological role. Using a stochastic model, we demonstrate how neglecting environmentally generated transmission chains could underestimate the explosiveness and duration of AIV epidemics. We show the important pathogen invasion implications of this phenomenon: the nonnegligible probability of outbreak even when direct transmission is absent, the long-term infectivity of locations of prior outbreaks, and the role of environmental heterogeneity in risk.