Totally found 10149028 items.

  • [期刊] Winter Coastal Divergence as a Predictor for the Minimum Sea Ice Extent in the Laptev Sea
    Seasonal predictability of the minimum sea ice extent (SIE) in the Laptev Sea is investigated using winter coastal divergence as a predictor. From February to May, the new ice forming in wind-driven coastal polynyas grows to a thickness approximately equal to the climatological thickness loss due to summer thermodynamic processes. Estimating the area of sea ice that is preconditioned to melt enables seasonal predictability of the minimum SIE. Wintertime ice motion is quantified by seeding passive tracers along the coastlines and advecting them with the Lagrangian Ice Tracking System (LITS) forced with sea ice drifts from the Polar Pathfinder dataset for years 1992-2016. LITS-derived landfast ice estimates are comparable to those of the Russian Arctic and Antarctic Research Institute ice charts. Time series of the minimum SIE and coastal divergence show trends of -24.2% and +31.3% per decade, respectively. Statistically significant correlation (r = -0.63) between anomalies of coastal divergence and the following September SIE occurs for coastal divergence integrated from February to the beginning of May. Using the coastal divergence anomaly to predict the minimum SIE departure from the trend improves the explained variance by 21% compared to hindcasts based on persistence of the linear trend. Coastal divergence anomalies correlate with the winter mean Arctic Oscillation index (r = 0.69). LITS-derived areas of coastal divergence tend to underestimate the total area covered by thin ice in the CryoSat-2/SMOS (Soil Moisture and Ocean Salinity) thickness dataset, as suggested by a thermodynamic sea ice growth model.
  • [期刊] Characterization of hepatic low-K_m outer-ring deiodination in red drum (Sciaenops ocellatus)
    The more biologically active thyroid hormone 3,5,3'-triiodothyronine (T_3), is primarily derived from peripheral deiodination of thyroxine (T_4). We characterized hepatic deiodination for a commercially important, warmwater teleost t fish, the red drum (Sciaenops ocellatus). Low K_m outer-ring deiodination (ORD) activity was determined by production of free iodide (1251) upon incubation of hepatic microsomes with radiolabeled T_4. APLC analysis demonstrated that 1251,and T_3 were produced in equal amounts, thereby validating 1251 as a measure of T_3 production. A small amount of t 3,3',5'-triiodothyronine (reverse T_3) was also produced by inner-ring deiodination. Production of 1251 was linear over a I range of 0-100 f1g protein/mI and for incubations of 30 min-4 h. Maximal ORD activity was measured at pA 6.6, 50 ; mM dithiothreitol (DTT) and an incubation temperature of 20°C. Double reciprocal plots demonstrated that the; average apparent K_m was 5.1 nM and the average V max was 3.7 pmol T_4 converted/h per mg protein. ORD was not ; inhibited by propylthiouracil but was 50% inhibited by 90 ~M of iodoacetic acid and 7 ~M of gold thioglucose. The substrate analog preference was T_4 = tetra iodoacetic acid = reverse T_3 > triiodoacetic acid ? T_3. In relation to other tissues, ORD for liver > gill > intestine > kidney. Similar hepatic deiodination activity was present in adult wild, aquacultured and laboratory-reared red drum, but in adult wild red drum the optimum temperature was higher. Red drum hepatic low-K_m deiodination activity appears to most closely resemble rainbow trout hepatic and mammalian Type II deiodination. Evidence of inner-ring T_4 deiodination suggests a more active hepatic iodothyronine catabolic pathway than in other teleost species.
  • [专利] Moleculas terapeuticas generadas por corte y empalme en trans.
    (ES2279531) The molecules and methods of the present invention provide a means for in vi vo production of a therapeutic molecule in a selected subset of cells. The pre-therapeutic molecules of the invention are substrat es for a trans-splicing reaction between the pre-therapeutic molecules and a pre-mRNA which is uniquely expressed in the specific target cells. The in vivo trans-splicing reaction provides an active therapeutic RNA which is functional as RNA or encodes a protein to be expressed in the target cells. The expression product of the mRNA is a protein of therapeutic value to the cell or a toxin which causes killin g of the specific cells. (From CA2240494 C)
  • [期刊] Infectious myocarditis: the role of the cardiac vasculature
    Infectious myocarditis is the result of an immune response to a microbial infection of the heart. The blood vessels of the heart, both the intramyocardial microvasculature and the large epicardial coronary arteries, play an important role in the pathogenesis of infectious myocarditis. First of all, in addition to cardiomyocytes, endothelial cells of the cardiac (micro)vasculature are direct targets for infection. Moreover, through the expression of adhesion molecules and antigen presenting Major Histocompatibility Complex molecules, the blood vessels assist in shaping the cellular immune response in infectious myocarditis. In addition, damage and dysfunction of the cardiac (micro)vasculature are associated with thrombus formation as well as aberrant regulation of vascular tone including coronary vasospasm. These in turn can cause cardiac perfusion abnormalities and even myocardial infarction. In this review, we will discuss the role of the cardiac (micro)vasculature in the pathogenesis of infectious myocarditis.
  • [期刊] 强化重金属污染土壤的螯合剂诱导植物提取研究
    从土壤和植物两方面介绍了螯合剂诱导植物提取的强化技术,具体阐述了合理选择植物种类、提高土壤重金属有效性的措施以及加强农艺管理及其他措施.结合当今土壤污染的具体情况对今后的研究重点进行了展望,提出了螯合剂诱导植物提取技术的发展趋势.
  • [期刊] Relevance of Abusive Head Trauma to Intracranial Hemorrhages and Bleeding Disorders
    BACKGROUND: Bleeding disorders and abusive head trauma (AHT) are associated with intracranial hemorrhage (ICH), including subdural hemorrhage (SDH). Because both conditions often present in young children, the need to screen for bleeding disorders would be better informed by data that include trauma history and are specific to young children. The Universal Data Collection database contains information on ICH in subjects with bleeding disorders, including age and trauma history. Study objectives were to (1) characterize the prevalence and calculate the probabilities of any ICH, traumatic ICH, and nontraumatic ICH in children with congenital bleeding disorders; (2) characterize the prevalence of spontaneous SDH on the basis of bleeding disorder; and (3) identify cases of von Willebrand disease (vWD) that mimic AHT.
  • [期刊] Ultrafine Ag Nanoparticles Encapsulated by Covalent Triazine Framework Nanosheets for CO2 Conversion
    This paper describes the fabrication of covalent triazine framework nanosheet-encapsulated Ag nanoparticles (Ag-0@CTFN) via a simple combination of the ultrasonic exfoliation and solution infiltration method. The as-prepared Ag-0@CTFN displays an order layered-sheet structure with abundant micropores and mesopores, whereas ultrafine Ag nanoparticles are confined and stabilized in their interlayers through the interaction between N sites of triazine units and Ag nanoparticles. Considering that the Ag-0@CTFN possesses the merits of high nitrogen, low density, and abundant basic sites, it was thus believed to have enough abilities to adsorb and activate CO2 in the CO2 conversion and catalysis. Importantly, the Ag-0@CTEN, as a heterogeneous catalyst, showed highly catalytic activity in the carboxylation of various alkynes with CO2 at ambient pressure and low temperature. This catalyst also exhibited good functional group tolerance and excellent stability without any significant loss of its activity after six recycles. This work not only achieves valuable and novel composite material but also provides the first application of covalent triazine framework nanosheets in chemical conversion of CO2, opening a new field in preparing recyclable heterogeneous catalysts to accelerate the utilization of CO2.
  • [专利] 一种配套弹性涂料的专用底漆及其制法和应用
    本发明涉及一种配套弹性涂料的专用底漆及其制法和应用,具体地所述底漆含有如下组分:0.5?20重量份功能单体改性苯丙乳液;10?50重量份改性苯丙乳液;10?50重量份颜/填料;2?15重量份成膜助剂;和2?10重量份防冻剂。本发明所述特定组成的底漆具有良好的耐盐析及抗泛碱性,其透水性能优良,并且与真弹面漆良好配套。
  • [期刊] 土壤环境中多环芳烃的微生物降解及联合生物修复
    研究土壤环境中持久性有机污染物的生物降解及其生物修复技术是当今国际环境修复科学技术前沿领域的重要课题.本文重点论述了土壤环境中持久性有机污染物多环芳烃的微生物降解机理及其在生物修复中的应用等,并结合当前研究进展,展望了基于多种修复措施相结合的多环芳烃污染土壤联合生物修复工程技术的开发与应用前景.
  • [期刊] 巡检无人机灾备应急充电装置
    无人机电力线巡检具备不受地形环境限制、机动灵活、安全性高、工作效率高等优点,可有效降低巡线成本.但是,无人机续航能力低,现有的充电装置难以满足灾后高强度巡检需求.笔者设计了适用于无人机巡检的灾备应急充电装置.此应急充电装置具备灾后巡检快速响应的特点,且可满足无人机高频次、高强度巡检的应急充电需求,能有效提高无人机电池的利用效率,减小备用电池数量,大幅扩大无人机的续航能力和巡航范围,对灾后无人机巡检起到重要的保障作用.
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