Vitamin B<Subscript>12</Subscript> Immunoassay on Roche Elecsys 2010: Effects of High Excess Concentration of Serum Vitamin B<Subscript>12</Subscript> in CKD Patients on Parenteral Administration

Vitamin B₁₂ being water soluble is excreted in the urine when administered in excess. The probability of finding an abnormally excess serum concentration would be almost surreal. We report a peculiar clinical situation that may impact the vitamin B₁₂ immunoassay on the Roche Elecsys 2010 due to excess analyte concentration. In separate episodes (Feb and June 2010), the Biochemistry laboratory of a tertiary-care hospital, Kolkata, India, encountered two critically ill patients with background chronic kidney disease (CKD), low urine output, and on cyanocoabalamin supplementation, who had serum vitamin B₁₂ concentrations far exceeding expected values; even post dialysis. The B₁₂ assays (pmol/l) were performed using electrochemiluminiscence immunoassay on Roche Elecsys 2010, the assay validity confirmed by concomitant quality control runs. The immunoassays failed to deliver results, flagged with “signal level below limit”. Biotin therapy was ruled out as a possible interferent. In the first episode, re-assay of a repeat draw yielded same outcome; outsourcing on Immulite provided concentration of >738 pmol/l. Serial dilution gave result of >29520 pmol/l on Elecsys 2010. In the second, we gained from past experience. Vitamin B₁₂ concentration >59040 pmol/l was conveyed to the treating nephrologist the very day. The B₁₂ immunoassay on the Elecsys 2010 employs sequential incubation steps for competitive binding that is compromised in the event of abnormally excess B₁₂ concentration in patient sera akin to the prozone effect. This knowledge may be beneficial while assaying sera of CKD patients to avoid financial loss due unnecessary repeats and delay in turnaround time.     

中断模拟下的中国沿海集装箱港口航运网络脆弱性

双循环背景下,国内消费市场的持续扩大有望进一步增加港口内贸集装箱比例,而海洋集装箱运输极易受到外界因素的影响,因此对国内海洋集装箱运输网络脆弱性的研究必要而紧迫.本文在港口中断模拟下,运用复杂网络特征指标从网络结构和节点抗干扰性能两方面,分析2005年和2017年中国沿海集装箱港口航运网络脆弱性,并探讨脆弱性的主要影响...     

Analysis of Intrinsic and Extrinsic Coagulation Pathway Factors in OCP Treated PCOS Women

Human polycystic ovary syndrome (PCOS)—a cluster of diseases displays various symptoms associated with endocrine and gynecological disorders in childbearing women. Oral contraceptive pills (OCP) being a drug of choice minimizes symptoms and complications associated with the disorder. But, the controversial data available in literature regarding use of OCPs compels us to setup a study design regarding effect of OCP treatment in PCOS subjects and the possible outcomes specifically regarding coagulation pathways. Two PCOS study groups have been selected according to Rotterdam Criteria: one with OCP treatment (n = 50) and other without any drug treatment i.e., drug naive (n = 50). Anthropometry, Biochemistry, Hormones, Insulin and various clotting factors like Factor XI, Factor V, tPA, TAT-III and D-dimer were analyzed in both groups. The results showed worsening of IR, Metabolic parameters and coagulopathy in OCP group comparative to drug naive group indicating adverse effects of the OCP treatment which puts these women at risk for number of future clinical implications especially Cardiovascular and metabolic complications.     

黄河宁蒙河段水文-水温过程和河道形态变化对凌汛的影响

黄河宁蒙河段的水文和水温过程近几十年来发生了显著变化,迫切需要评估这一变化对河道形态、凌汛的影响及其可能的致灾效应。利用同水位河道过水断面形态参数分析方法,选取宁蒙河段稳定封冻区域（石嘴山-头道拐）的石嘴山、磴口、巴彦高勒、三湖河口和头道拐5个主要水文站,根据2008-2013年凌汛前实测断面资料,计算相应年份5个水文站同水位下的河道断面面积、平均水深和深泓点高程。结果表明,宁蒙河段近年来凌汛期的径流量和水温呈现逐渐增大的趋势,下泄流量过程有助于减少凌灾发生的几率;各水文站凌汛前的断面面积和平均水深等断面形态参数呈逐年增大的趋势,深泓点高程不断降低。河道过水断面形态的这种变化增大了凌汛期河道的过流能力,有助于缓解开河期可能出现的凌汛灾情。     

Profile of Plasma Amino Acid Levels in Rats Exposed to Acute Hypoxic Hypoxia

The effect of acute hypoxic hypoxia on the profile of plasma amino acids in rats was studied and compared to that resulting from acute liver injury induced by giving carbon tetrachloride. In hypoxic rats exposed to 45% air in N₂ for 5 h, the concentrations of branched chain amino acids, including valine, leucine and isoleucine, and aromatic amino acids such as phenylalanine and tyrosine were significantly increased as compared to those in normoxic rats. The ratio of branched-chain to aromatic amino acids (Fischer’s ratio) was significantly decreased. The levels of arginine and citrulline, which are related to the urea cycle, were also depressed. Furthermore, plasma proline level was reduced in hypoxic rats. The activities of plasma marker enzymes for tissue damage remained unchanged during hypoxia, indicating that tissue injury was not induced by exposure to hypoxic conditions. We suggest that the characteristic profile of plasma amino acids and the Fischer ratio are valuable tools for understanding the pathology of acute hypoxia in the absence of systemic tissue damage.     

基于统计检验的降雨侵蚀力简易计算模型比较

降雨侵蚀力因子（R）的准确估算对提高侵蚀预测的精度具有重要作用,但R的计算需要高时间分辨率的降雨过程资料。基于日、月、年降雨资料,目前已开发了众多的R值简易计算模型（PR）。本文通过Meng’s检验比较了不同PR模型结果与R的相关性是否存在显著性差异,并以此为基础评估了国内外15种PR模型在中国东部地区的适用性。结果表明,15种PR模型计算结果与R均显著相关（r >0.59,p<0.03）,表明这些方法均适用于中国东部地区,但由于存在系统偏差,许多模型需要按文中建立的回归关系式校正后得到更优的估算结果。相关系数的统计学比较表明,日降雨PR模型的计算结果与R相关性明显优于年和月降雨模型,而年和月降雨模型差异不明显。所有模型中,3种基于中国数据（包括国内最常用的章文波模型和第一次全国水利普查采用的模型）和1种基于澳大利亚数据建立的日降雨PR模型的相关性并列处于最高等级（r >0.99）,但该澳大利亚模型的计算偏差随纬度增高而变大,章文波模型也存在约30%的系统误差,两者校正后使用能获得更好的效果;第一次全国水利普查采用的模型则可以直接用于R的估算,不需要进行校正处理。论文最终给出了获取不同时间分辨率降雨资料时建议使用的PR模型。     

中国沿海省份蓝碳现状与能力评估

中国海岸线总长度超过3.26万km,同时拥有红树林、盐沼、海草床3类蓝碳生态系统,且海水养殖产量常年位居世界首位,蓝碳发展条件得天独厚。本文在系统梳理国内外蓝碳研究成果的基础上,基于广义蓝碳定义,尝试从自然生态系统和海水养殖系统两方面构建中国沿海省份蓝碳核算体系,基于相关统计数据、遥感数据、核算参数数据,对中国沿海省份蓝碳进行核算,分析其时空演化格局,并利用Super-SBM模型进一步对中国海水养殖碳汇渔业效率进行评估。研究表明：①中国蓝碳生态系统面积呈波动增长,1997—2019年红树林固碳量为0.033~0.078 Tg C/a,盐沼固碳量为0.234~0.646 Tg C/a,海草床固碳量为0.012~0.018 Tg C/a;②沿海九省2003—2020年的海水养殖年固碳总量为0.87~1.36 Tg C/a,省际空间差异显著,并在各时段表现出不同的增长特征;③沿海九省年蓝碳总量及结构的空间分布格局差异明显,就蓝碳能力而言,山东和福建蓝碳能力最高;就蓝碳结构而言,江苏的蓝碳构成比例较为均衡;④土地利用变化、蓝碳生态系统与海水养殖的不协调发展、气候变化等是影响蓝碳能力的重要因素,沿海九省2003—2020年的碳汇渔业效率值反映出海水养殖经济指标投入与生态环境产出存在一定失调,这也会遏制蓝碳的挖掘和利用。最后本文就蓝碳助力国家碳中和战略提出相应的优化建议。     

美国征收铝产品关税的潜在影响及对策

2018年初,美国发布了对8种进口铝产品征收10%的从价税的公告,给世界各国特别是中国的铝工业带来诸多潜在影响。本文以该公告中涉及的铝产品为研究对象,分析了美国铝产品的贸易格局,考察了美国征收铝关税的潜在影响,并提出中国的若干应对策略。研究显示：① 造成美国铝贸易逆差的关键产品是能耗和环境负荷高但附加值低的未锻轧铝（铝锭）,而在其他7种附加值较高的铝产品中,美国的合计贸易额处于顺差状态,这是由美国自身的产业结构造成的。将造成美国铝产品贸易逆差的责任推给中国及其他国家的做法是荒谬和不负责任的;② 美国征收铝产品关税的真正目的可能是通过缩减进口量来加强国内高附加值铝产品的生产经营能力。存在贸易逆差的铝箔、铝丝和其他铝产品,以及贸易量较大的铝板带对美出口难度将会越来越大;③ 短期看,中国生产铝箔、铝丝、其他铝产品和铝板带的企业将面临较大困难;长期看,铝关税可能仅仅是美国贸易保护政策的开始,中国政府和企业必须做好打持久战的准备。近期,中国应采取有针对性的贸易报复措施,联合其他国家和在此次关税变化中可能受到较大负面影响的美国国内相关产业共同对特朗普政府施压。长期,中国要继续加强产品研发和自主创新能力,加快弥补产业链和技术短板,提高应对国际形势影响中国经济发展的能力。     

失败视角下变革型领导对员工创造力的影响

基于失败视角，本文运用社会信息加工理论，探究变革型领导对员工创造力的跨层次影响及团队失败共享信念和员工归属感在其中的作用，对60个团队中302对领导-员工配对数据进行分析，得到结论：变革型领导对员工创造力具有显著的跨层次正向影响，且对团队失败共享信念具有显著的正向影响；团队失败共享信念在变革型领导与员工创造力关系之间起到跨层次中介作用；员工归属感在团队失败共享信念与员工创造力关系之间起到正向调节作用。     

Au23(CR)14 nanocluster restores fibril Aβ’s unfolded state with abolished cytotoxicity and dissolves endogenous Aβ plaques

The misfolding of amyloid-β (Aβ) peptides from the natural unfolded state to β-sheet structure is a critical step, leading to abnormal fibrillation and formation of endogenous Aβ plaques in Alzheimer''s disease (AD). Previous studies have reported inhibition of Aβ fibrillation or disassembly of exogenous Aβ fibrils in vitro. However, soluble Aβ oligomers have been reported with increased cytotoxicity; this might partly explain why current clinical trials targeting disassembly of Aβ fibrils by anti-Aβ antibodies have failed so far. Here we show that Au₂₃(CR)₁₄ (a new Au nanocluster modified by Cys-Arg (CR) dipeptide) is able to completely dissolve exogenous mature Aβ fibrils into monomers and restore the natural unfolded state of Aβ peptides from misfolded β-sheets. Furthermore, the cytotoxicity of Aβ₄₀ fibrils when dissolved by Au₂₃(CR)₁₄ is fully abolished. More importantly, Au₂₃(CR)₁₄ is able to completely dissolve endogenous Aβ plaques in brain slices from transgenic AD model mice. In addition, Au₂₃(CR)₁₄ has good biocompatibility and infiltration ability across the blood–brain barrier. Taken together, this work presents a promising therapeutics candidate for AD treatment, and manifests the potential of nanotechnological approaches in the development of nanomedicines.     

失败视角下变革型领导对员工创造力的影响

基于失败视角,本文运用社会信息加工理论,探究变革型领导对员工创造力的跨层次影响及团队失败共享信念和员工归属感在其中的作用,对60个团队中302对领导—员工配对数据进行分析,得到结论：变革型领导对员工创造力具有显著的跨层次正向影响,且对团队失败共享信念具有显著的正向影响;团队失败共享信念在变革型领导与员工创造力关系之间起到跨层次中介作用;员工归属感在团队失败共享信念与员工创造力关系之间起到正向调节作用。     

Study of Serum Homocysteine, Folic Acid and Vitamin B12 in Patients with Preeclampsia

The present study was carried out to evaluate the occurrence of association between homocysteine, folic acid and vitamin B(12) in patients with preeclampsia. Fifty preeclamptic patients from gynecology ward were studied for estimation of serum homocysteine, folic acid and vitamin B(12) over a period of October 2007 to June 2010. Serum homocysteine and folic acid, and vitamin B(12) were determined by means of Immulite 1000 analyzer. The statistical analysis of study group of preeclampsia compared with normotensive control group, showed significant alterations in serum homocysteine, folic acid and vitamin B(12) concentrations in preeclampsia. Inverse association between serum homocysteine and folic acid, and vitamin B(12) levels were observed in preeclampsia. The present study found hyperhomocysteinemia and deficiency of folic acid and vitamin B(12) along with increased blood pressure as a risk factor for cardiovascular disease (CVD) in preeclampsia.