The validity of burrow counting in estimating the densities of Chiromantes dehaani and Ilyoplax deschampsi in tidal flat at Yangtze Estuary

It has been confirmed that the crabs play significant roles in the structure and function of coastal wetland ecosystems, such as mangroves and salt marshes. However it is not easy to estimate the abundance and density of burrowing crabs effectively, thus a further understanding of roles of crabs in these ecosystems has been lagged. Some studies have discussed the suitability of several census techniques, such as burrow counting method in estimating crab density in mangroves. The validities of burrow counting method and other census techniques in estimating crab density, however, has not been tested in salt marshes, especially where vegetation are dense. In this study, we tested the validity of burrow counting method in estimating the densities of Chiromantes dehaani and Ilyoplax deschampsi in tidal flat with dense vegetation of Phragmites australis and Zizania aquatica at Yangtze Estuary through comparing densities estimated by the burrow counting method and the excavation. Burrow counting averagely underestimated the density of C. dehaani by 15% and the degree of underestimation varied among vegetations and habitats (from an overestimate by 23% to underestimate by 41%). Burrow counting averagely overestimated the density of I. deschampsi by 43% and the degree of overestimate varied from 0% to 133% depending on the vegetations and habitats. The percentage of occupied burrows and the number of crabs sharing one burrow were important factors influencing the validity of estimating crab density through burrow counting method.     

Process analytical technology (PAT) for biopharmaceutical products: Part II. Concepts and applications

Implementing real‐time product quality control meets one or both of the key goals outlined in FDA's PAT guidance: “variability is managed by the process” and “product quality attributes can be accurately and reliably predicted over the design space established for materials used, process parameters, manufacturing, environmental, and other conditions.” The first part of the paper presented an overview of PAT concepts and applications in the areas of upstream and downstream processing. In this second part, we present principles and case studies to illustrate implementation of PAT for drug product manufacturing, rapid microbiology, and chemometrics. We further present our thoughts on how PAT will be applied to biotech processes going forward. The role of PAT as an enabling component of the Quality by Design framework is highlighted. Integration of PAT with the principles stated in the ICH Q8, Q9, and Q10 guidance documents is also discussed. Biotechnol. Bioeng. 2010; 105: 285–295. Published 2009 Wiley Periodicals, Inc.     

Immature cat oocyte vitrification in open pulled straws (OPSs) using a cryoprotectant mixture

Cryopreservation of gametes is an important tool in assisted reproduction programs to optimise captive breeding programmes of selected felid species. In this study the vitrification was evaluated in order to cryopreserve the immature domestic cat oocytes by assessing the survival of cumulus-oocyte complexes (COC), and the development competence after IVM and IVF by fresh cat epididymal sperms. From a total of 892 COC obtained from queens after ovariectomy were divided into two groups: Experiment 1 for viability evaluation (150 vitrified and 100 control COC) and Experiment 2 for assessing the developmental competence (414 vitrified and 228 control COC). The viability was evaluated by double staining with carboxyfluorescein and Trypan blue, while the developmental competence was evaluated by in vitro maturation (IVM), in vitro fertilisation (IVF) by fresh epididymal spermatozoa and in vitro culture (IVC). The vitrification was performed in OPS into sucrose medium (1 M sucrose in HSOF + 6% BSA) containing dimethyl sulfoxide (DMSO) (16.5% final concentration) and ethylene glycol (EG) (16.5% final concentration) as cryoprotectants. Percentage of non-viable COC was significantly higher in Experimental 1 vs Control 1 (11% vs 54.5%; P < 0.01), while cleavage rate were significantly lower for vitrified oocytes (Experimental 2) than control 2 (18.6% vs 48.2%; P < 0.01). Blastocyst rate on day 8 was higher for control oocytes than vitrified counterparts (4.3% vs 20.6% P < 0.01). This vitrification protocol ensured a development to blastocyst stage and it is the first report of development of vitrified GV COC.     

金针虫调查方法及评价

金针虫是一类重要的地下害虫,其种群数量调查是植物保护工作中的难点之一。文章概述金针虫种群数量调查的3种主要方法:土方抽样、诱饵诱捕及成虫性信息素诱捕。就其调查原理、特点及研究现状进行了介绍,并对各方法的不足及应用前景做了简要分析。     

Geostatistical analysis of regional differences in stem taper form of Pinus densiflora in central Korea

This study verified regional differences in the stem form of Pinus densiflora Sieb. et Zucc. (red pine) and identified the relationship between stem form and climatic factors in the central region of the Korean peninsula. Regional differences in stem form index at tree base (butt) and top stem section were found. Compared to the stem form in the eastern uplands, the stem form in the western lowlands could be characterized by a more conical butt section and more cylindrical middle and upper section. Through geostatistical analysis of kriging and spatial regression, several climatic factors proved to exert a meaningful influence on stem taper form. On the stem form at the butt section, the precipitation during the late growing season exerts statistically significant effects. High precipitation during the growing season in the western lowland and coastal region causes the stem form at the butt section to be more tapered. On the stem form at the middle and upper section, temperature and precipitation during the growing season, and wind during the late growing season have statistically meaningful influences. High temperature, precipitation, and wind during the growing season in the western lowland and coastal region jointly influence the stem form at the middle and upper sections which result in more cylindrical profiles. This study can be considered an initial investigation into the factors controlling stem form variability in the central region of the Korean peninsula. The results can be used to develop more accurate regional stem taper models needed for reasonable management of red pine stands in different regions.

Immobilization strategies to develop enzymatic biosensors

Immobilization of enzymes on the transducer surface is a necessary and critical step in the design of biosensors. An overview of the different immobilization techniques reported in the literature is given, dealing with classical adsorption, covalent bonds, entrapment, cross-linking or affinity as well as combination of them and focusing on new original methods as well as the recent introduction of promising nanomaterials such as conducting polymer nanowires, carbon nanotubes or nanoparticles. As indicated in this review, various immobilization methods have been used to develop optical, electrochemical or gravimetric enzymatic biosensors. The choice of the immobilization method is shown to represent an important parameter that affects biosensor performances, mainly in terms of sensitivity, selectivity and stability, by influencing enzyme orientation, loading, mobility, stability, structure and biological activity.     

Evaluating metabolic stress and plasmid stability in plasmid DNA production by Escherichia coli

In the context of recombinant DNA technology, the development of feasible and high-yielding plasmid DNA production processes has regained attention as more evidence for its efficacy as vectors for gene therapy and DNA vaccination arise. When producing plasmid DNA in Escherichia coli, a number of biological restraints, triggered by plasmid maintenance and replication as well as culture conditions are responsible for limiting final biomass and product yields. This termed "metabolic burden" can also cause detrimental effects on plasmid stability and quality, since the cell machinery is no longer capable of maintaining an active metabolism towards plasmid synthesis and the stress responses elicited by plasmid maintenance can also cause increased plasmid instability. The optimization of plasmid DNA production bioprocesses is still hindered by the lack of information on the host metabolic responses as well as information on plasmid instability. Therefore, systematic and on-line approaches are required not only to characterise this "metabolic burden" and plasmid stability but also for the design of appropriate metabolic engineering and culture strategies. The monitoring tools described to date rapidly evolve from laborious, off-line and at-line monitoring to online monitoring, at a time-scale that enables researchers to solve these bioprocessing problems as they occur. This review highlights major E. coli biological alterations caused by plasmid maintenance and replication, possible causes for plasmid instability and discusses the ability of currently employed bioprocess monitoring techniques to provide information in order to circumvent metabolic burden and plasmid instability, pointing out the possible evolution of these methods towards online bioprocess monitoring.     

The use of biophysical proteomic techniques in advancing our understanding of diseases

The use of proteomic approaches in investigating diseases is continuing to expand and has started to provide answers to substantial gaps in our understanding of disease pathogenesis as well as in the development of effective strategies for the early diagnosis and treatment of diseases. Biophysical techniques form a crucial part of the advanced proteomic techniques currently used and include mass spectrometry and protein separation techniques, such as two-dimensional gel electrophoresis and liquid chromatography. The application of biophysical proteomic techniques in the study of disease includes delineation of altered protein expression, not only at the whole-cell or tissue levels, but also in subcellular structures, protein complexes, and biological fluids. These techniques are also being used for the discovery of novel disease biomarkers, exploration of the pathogenesis of diseases, development of new diagnostic methodologies, and identification of new targets for therapeutics. Proteomic techniques also have the potential for accelerating drug development through more effective strategies for evaluating a specific drug’s therapeutic effects and toxicity. This article discusses the application of biophysical proteomic techniques in delineating cardiovascular disease and other diseases, as well as the limitations and future research directions required for these techniques to gain greater acceptance and have a larger impact.     

海洋生境修复和生物资源养护原理与技术研究进展及展望

由于人类活动导致的海洋生境、生态系统以及生物资源的衰退已经引起了全球的高度重视。以生态修复的原理为基础,综述了海洋生境修复和生物资源养护的关键设施、关键技术、监测与效果评价以及综合管理的国内外研究进展,并对海洋生境修复与生物资源养护的研究热点和重点进行了展望,以期为我国海洋生境修复和生物资源养护提供参考。     

不同手术方式对腰椎间盘突出症治疗的效果比较分析

目的:探讨应用微创技术治疗腰椎间盘突出症的疗效.方法:对我院脊柱骨科自2005年l1月～2010年10月收治的128例腰椎间盘突出症患者应用不同手术方式进行治疗,其中应用APLD( automated percutaneous lumbar discectomy)治疗单纯腰椎间盘突出症48例;应用MED(microendoscopic discectomy)治疗复杂型腰椎间盘突出症42例;应用传统后路椎板开窗技术治疗单纯腰椎间盘突出症38例;比较各组手术时间、术中出血、术后住院时间、疗效及并发症.术后均随访8个月～3年,观察复发情况.结果:三组不同手术方式手术时间及优良率比较差异无统计学意义(P＞0.05),APLD及MED组术中出血量及术后住院时间与传统手术组比较,差异有显著性(P＜0.05);术后随访疼痛全部缓解,无复发.结论:在严格掌握适应症的基础上,采用微创技术和采用传统手术治疗腰椎间盘突出症疗效相当,但微创技术创伤小、术中出血量少,术后住院日短,恢复快,优于传统手术.