湖北樟属数量化学分类研究

本文利用湖北樟属植物13号精油的气相色谱／质谱／电子计算机联用分析的结果，从 已鉴定出的108个化学成分中，筛选出30个主要成分，综合各种植物的17个主要形态特征，进行数量分类研究。数学分析结果揭示了樟属各种性状变化的规律性，尤其是形态特征 与化学成分之间的相关性。乙酸龙脑酯、反式-甲基异丁香酚和芳樟醇等重要香精原料的含 量，与某些形态特征的变化密切相关，罗勒烯可能是樟属分组的特征性成分。本文还在聚类 分析的基础上，进一步探讨了分类群的划分，并根据精油成分在不同种和同种不同类型中的 分布及含量，参照各分类群之间的相关系数，对其演化关系作出了推论。湖北樟属植物可能起源于我国西南的黄樟樟脑型，而芳樟和黄樟芳樟醇型则是最进化的类群。     

The impact of microfluidics in high-throughput drug-screening applications

Drug discovery is an expensive and lengthy process. Among the different phases, drug discovery and preclinical trials play an important role as only 5–10 of all drugs that begin preclinical tests proceed to clinical trials. Indeed, current high-throughput screening technologies are very expensive, as they are unable to dispense small liquid volumes in an accurate and quick way. Moreover, despite being simple and fast, drug screening assays are usually performed under static conditions, thus failing to recapitulate tissue-specific architecture and biomechanical cues present in vivo even in the case of 3D models. On the contrary, microfluidics might offer a more rapid and cost-effective alternative. Although considered incompatible with high-throughput systems for years, technological advancements have demonstrated how this gap is rapidly reducing. In this Review, we want to further outline the role of microfluidics in high-throughput drug screening applications by looking at the multiple strategies for cell seeding, compartmentalization, continuous flow, stimuli administration (e.g., drug gradients or shear stresses), and single-cell analyses.     

Review of microfluidic microbioreactor technology for high-throughput submerged microbiological cultivation

Microbial fermentation process development is pursuing a high production yield. This requires a high throughput screening and optimization of the microbial strains, which is nowadays commonly achieved by applying slow and labor-intensive submerged cultivation in shake flasks or microtiter plates. These methods are also limited towards end-point measurements, low analytical data output, and control over the fermentation process. These drawbacks could be overcome by means of scaled-down microfluidic microbioreactors (μBR) that allow for online control over cultivation data and automation, hence reducing cost and time. This review goes beyond previous work not only by providing a detailed update on the current μBR fabrication techniques but also the operation and control of μBRs is compared to large scale fermentation reactors.     

Microwell perfusion array for high-throughput, long-term imaging of clonal growth

Continuous cell tracking by time-lapse microscopy has led to detailed study of cell differentiation pathways using single cell fate maps. There are a multitude of cell fate outcomes, so hundreds of clonal division histories are required to measure these stochastic branching processes. This study examines the principle of condensing cell imaging information into a relatively small region to maximize live cell imaging throughput. High throughput clonal analysis of non-adherent cells by continuous live cell tracking was possible using a microwell perfusion array with an internal volume of 16 μl and 600 microwells at the base. This study includes examination of biocompatibility of buffer systems, connecting tubing, cell culture substrates, and media degradation. An intermittent perfusion protocol was selected for long-term time-lapse imaging of KG1a cells in the microwell array; 1500 clones were simultaneously cultured and scanned every 3 min at 100 × magnifications for 6 days. The advantages of perfusion microwell culture are continuous long-term cell tracking, higher cell imaging throughput, and greater control over cell microenvironment. Microwell devices facilitate high throughput analysis of cell lineage development and measurement of the probability distribution for cell life events such as mitosis.     

SBR亚硝化处理化肥厂氨氮废水影响因素分析

利用SBR亚硝化处理化肥厂实际废水,研究其短程生物脱氮过程中pH、溶解氧、进水氨氮负荷和温度等因素影响,并确定亚硝化处理的最佳操作条件。结果表明,pH过低会抑制亚硝酸盐的生成,过高则不利于反硝化菌反硝化过程TN的去除;当pH值控制在8.0左右时,亚硝化率保持较高水平,同时出水TN浓度控制较好。当DO浓度为0.2~0.3 mg/L时,亚硝化反应继续进行,但NH4+-N亚硝化反应速率较慢;当DO浓度为1.5~2.8 mg/l时,无法实现系统中亚硝化的运行,硝化作用成为主要反应。高氨氮负荷进水有利于亚硝酸盐的积累,但对出水氨氮去除效果不佳。较高的温度有利于亚硝化反应进行。当t=35℃,初始pH控制在7.8~8.2,DO控制在0.5~0.6mg/L,进水浓度NH4+-N为100mg/L时,SBR亚硝化操作过程为最佳,此时亚硝化率基本稳定在90%以上。     

Unraveling templated-regulated distribution of isolated SiO4 tetrahedra in silicoaluminophosphate zeolites with high-throughput computations

Silicoaluminophosphate (SAPO) zeolites are well-known catalytic materials because of the mild acidity originating from the isolated SiO₄ tetrahedra in their frameworks. Regulating the distribution of isolated SiO₄ tetrahedra in SAPO zeolites is formidably challenging because SiO₄ tetrahedra tend to agglomerate to form Si islands and the isolated SiO₄ tetrahedra are difficult to determine using conventional characterization techniques. Here we synthesized Si-island-free SAPO-35 zeolites by using N-methylpiperidine as a new template, which exhibited excellent thermal stability compared to conventional SAPO-35 zeolites and a substantially improved methanol-to-olefins catalytic lifetime even comparable to that of commercial SAPO-34 zeolites. More strikingly, with the aid of high-throughput computations on 44 697 structure models combined with various state-of-the-art characterization techniques, for the first time, we reveal that the host–guest interactions between template molecules and SAPO frameworks determine the specific distributions of isolated SiO₄ tetrahedra, which are responsible for the improvement in the chemical properties of zeolites. Our work provides an insight into the template-based regulation of isolated SiO₄ tetrahedra in SAPO zeolites, which opens a new avenue in the discovery of promising zeolite catalysts with optimal SiO₄ distribution.     

Structural analysis by electric circuit analogies

Electric circuits may be constructed which obey the same laws as structures under load. Measurements on the circuits will then give the stresses, deflections, etc., of the corresponding structures. Circuits are given for determinate and indeterminate pin-connected and rigidly-connected structures in the static and the dynamic state. Experimental work is reported on relatively simple typical cases to show the apparatus and methods of measurement which are applicable, and the precision obtainable.     

Serum proteins analysis by capillary electrophoresis

The purpose of this study was to evaluate the efficacy of multi-capillary electrophoresis instrument in clinical laboratory. An automated clinical capillary electrophoresis system was evaluated for performing serum proteins electrophoresis and immuno-fixation electrophoresis by subtraction. In this study the performance of capillary electrophoresis was compared with the cellulose acetate membrane electrophoresis and agarose gel immunofixation electrophoresis for serum proteins. The results of capillary electrophoresis and cellulose acetate membrane electrophoresis were good (r=0.89∼0.97) for protein fractions and A/G ratio except for β-gobulin fraction (r=0.60). Both within-run and day to day precisions (CVs) of assay results for 5 main fractions and A/G ratio (n=10) were between 0.3∼6.3%. The reference ranges of serum protein fractions obtained from 200 healthy individuals by cellulose acetate membrane electrophoresis were almost equal to that of capillary electrophoresis except for α-1 globulin fraction. No significant difference of electropherograms between cellulose acetate electrophoresis and capillary electrophoresis was observed in the abnormal serum such as presence of bilirubin (<20mg/dl), hemoglobin (<300 mg/dl), lipid (Intralipos <1%) and samples from patients with acute phase response, liver injury, polyclonal hyper gammaglobulinemia or M-proteinemia. The method of capillary immuno-fixation electrophoresis by subtraction showed good agreement with agarose gel immunofixation electrophoresis by subtraction identifying 30 monoclonal gammmopathy patient samples.     

Understanding divergent domestication traits from the whole-genome sequencing of swamp- and river-buffalo populations

Domesticated buffaloes have been integral to rice-paddy agro-ecosystems for millennia, yet relatively little is known about the buffalo genomics. Here, we sequenced and assembled reference genomes for both swamp and river buffaloes and we re-sequenced 230 individuals (132 swamp buffaloes and 98 river buffaloes) sampled from across Asia and Europe. Beyond the many actionable insights that our study revealed about the domestication, basic physiology and breeding of buffalo, we made the striking discovery that the divergent domestication traits between swamp and river buffaloes can be explained with recent selections of genes on social behavior, digestion metabolism, strengths and milk production.     

Inventive progress measured by multi-stage patent citation analysis

Studies of technological change constitute a field of growing importance and sophistication. In this paper we contribute to the discussion with a methodological reflection and application of multi-stage patent citation analysis for the measurement of inventive progress. Investigating specific patterns of patent citation data, we conclude that single-stage citation analysis cannot reveal technological paths or lineages. Therefore, one should also make use of indirect citations and bibliographical coupling. To measure aspects of cumulative inventive progress, we develop a “shared specialization measure” of patent families. We relate this measure to an expert rating of the technological value added in the field of variable valve actuation for internal combustion engines. In sum, the study presents promising evidence for multi-stage patent citation analysis in order to explain aspects of technological change.     

开关操作瞬态电磁骚扰的特征分析方法

对变电站中由开关操作引起的瞬态电磁骚扰实测数据的时域特征和频域特征进行了统计分析.时域特征分析提出了2种方法,一是统计直方图,二是正态性检验,重点针对正态性检验提出了适合的处理方法和流程,并进行了软件实现;频域特征分析采用了总体求取包络的方法.针对实测瞬态骚扰样本的统计结果,分析了文中特征分析方法的意义和应用价值.     

Bibliometric cartography of information retrieval research by using co-word analysis

The aim of this study is to map the intellectual structure of the field of Information Retrieval (IR) during the period of 1987–1997. Co-word analysis was employed to reveal patterns and trends in the IR field by measuring the association strengths of terms representative of relevant publications or other texts produced in IR field. Data were collected from Science Citation Index (SCI) and Social Science Citation Index (SSCI) for the period of 1987–1997. In addition to the keywords added by the SCI and SSCI databases, other important keywords were extracted from titles and abstracts manually. These keywords were further standardized using vocabulary control tools. In order to trace the dynamic changes of the IR field, the whole 11-year period was further separated into two consecutive periods: 1987–1991 and 1992–1997. The results show that the IR field has some established research themes and it also changes rapidly to embrace new themes.     

对社会资本举办医疗机构现状的分析

社会资本和医院双方都有投资和引入的能力和意愿,但是,要想医疗机构引入社会资本后能够促进医疗卫生事业发展得又快又好,必须做到相关的法律法规完善并落实,市场环境公平化,才能让医疗机构更有效地引入社会资本,既促进了医疗市场发展又使社会资本获利。     

舒巴坦钠相关物质高效液相色谱分析

舒巴坦钠本身抑茵作用较弱,是一种竞争性、不可逆的β-内酰胺酶抑制剂药,通常与头孢哌酮钠、氨苄西林钠、阿莫西林钠、哌拉西林钠等联合应用;舒巴坦可防止耐药茵对青霉素类和头孢菌素类抗生素的破坏,舒巴坦与青霉素类和头孢菌素类抗生素具有明显的协同作用。国内通常采用中国药典2005年版相关物质的检测方法进行检测,经检测不同生产厂家的舒巴坦钠,在主成分峰保留时间的3倍停止后,通常在7倍左右还有其杂质,不能够完全洗脱,完成一个样品的杂质分析需要近50分钟。现采用梯度的洗脱方法,不仅缩短了检测的时间,还可对其杂质进行定性,为指导生产过程中的杂质控制,提供了可靠的数据。     

运用引文分析进行论文评价的方法初探——引文分析中期刊影响因子的运用

本介绍了期刊影响因子的概念，尝试了在引分析中引入期刊影响因子进行量化分析，并分析了论评价中的存在问题，认为引分析可作为论评价的一个重要方法之一，期刊影响因子也是目前一个可用的重要指标，任何一种方法都有利有弊，在具体的评价过程中应该尝试多种评价方法和手段，以期评价结果更加科学合理。