污染使西班牙水生物变性

西班牙科学家调查发现，西班牙河流和沿海水域一些鱼、甲壳类和软体类动物大量变性。研究表明，这是一些水域受到化学物质污染造成的水生动物“性畸变”。

生物变性平常事

对于人类来说,男性变女性、女性变男性,的确是不多见的新鲜事.然而在生物界中,这却是一种司空见惯的性变现象.人类对生物性变现象的研究首先是从低等生物--细菌开始的.在人的大肠里寄生着一种杆状细菌,被称为大肠杆菌.在电子显微镜下可以发现,大肠杆菌有雌雄之分,雌的两端是圆形,雄的则两头尖尖.令人惊奇的是,每当雌雄互相接触时,就会发生奇特的性逆转,即雄的变为雌的,雌的则变为雄的.经科学家研究发现,雌雄互变的媒介是一种叫"性决定素"的东西,当雌雄接触时,它们将"性决定素"互赠给对方,从而改变了彼此的性别.

一种基于B超图像处理的生物组织变性监测方法

本文提出基于B超图像灰度和小波变换系数并结合BP神经网络监测HIFU治疗中生物组织变性的方法。通过对高强度聚焦超声打击新鲜离体猪肉组织前后获得的B超图像作数字减影,并提取图像特征,利用神经网络进行分类处理。在此基础上,对大量实验数据处理后的统计特性和误差进行分析,得出较好的辨识效果。结果表明:结合图像平均灰度和小波变换系数特征并输入BP神经网络,能够更好地监测HIFU治疗中生物组织是否变性。

PROPERTIES OF BIODEGRADABLE THERMOPLASTIC STARCH

Thermoplastic starch is a kind of modified starch produced by mixing starch with additives and processing the mixture in an extruder. The mechanical properties, including tensile strength and elongation at break, biodegradability and rheological properties were studied. Glycerol and urea, to some extent, can both decrease the tensile strength and increase percentage elongation at break, because the former acts as a plasticizer and the latter can break down interactions among starch macromolecules. Thermoplastic starch shows thermoplasticity and its melt behaves as a pseudoplastic liquid at a low shear rate. Its biodegrading extent is slightly higher than that of native starch. The molecular weight of starch displays a decreasing tendency after thermoplastic modification.

Effects of mutation on a new strain Leptospirillum ferriphilum YXW and bioleaching of gold ore

Leptospirillum ferriphilum YXW was isolated through serial dilution from mixed microorganisms enriched in AMD from Dexing copper mine in Jiangxi Province, China. It was mutated by ultrasonic, UV and microwave to collect more efficient strain for bioleaching of gold ore. Physiological and biochemical characteristics indicate that strain YXW is a strict chemoautotrophic microorganism, and the optimal condition for its growth is temperature of 40 °C and pH 1.5. After mutation by ultrasonic, UV and microwave, the density of bacterial cells reached 9×109, 8.4×109 and 4.3×108 mL-1, increased by 291%, 265%and 87%, respectively, compared with the original culture. The bacterial total protein activity was improved by microwave and UV mutations, but was reduced by ultrasonic. Mutations had effects on bioleaching of gold ore in sequence of microwave〉UV〉ultrasonic. During gold ore bioleaching, the bacterial mutant after mutation by microwave had the best effect on the extraction rates of arsenic and iron, which were 19.6%and 17.7%higher than that of the original strain after bioleaching for 10 d, respectively. The results suggested that the effects of mutation on bioleaching of gold ore may not be mainly due to increase of bacterial cells density, but may be mainly attributed to the improvement of bacterial total protein activity.

Impact analysis of supplier relationship on supply chain resilience using biological cellular resilience theory

A supply chain resilience model is established based on the biological cellular resilience theory to analyze the impact of the supplier relationship on supply chain resilience. A scenario where the market demand is changed suddenly by some undesired events is considered. The results reveal that enhancing collaboration with a more resilient supplier can significantly improve supply chain resilience and reduce supply chain losses. It is also found that enhancing the supplier relationship can significantly benefit supply chain resilience if the collaborative intensity is relatively low, and it has less effect if supply chain members have already collaborated closely. Thus, enhancing the supplier relationship to a limited intensity is a relatively effective and economic method to strengthen supply chain resilience.

Analysis on the Essential Characters and Biological Yield Change of Purple-fleshed Sweetpotato Xuzishu 3

Objective] This study was performed to investigate the trait changes and their correlations as wel as the dynamic changes of biological yield of Xuzishu 3, which wil help to enhance the yield and anthocyanin content of sweetpotato by cul-tivation. [Method] We systematical y measured the agronomic traits, qualitative char-acters and biological yield of Xuzishu 3 during six growing periods to investigate the dynamic changes of its essential characters and yield accumulation. [Result] The characters of Xuzishu 3 appeared most prosperous after the 90th d except for an-thocyanin content. Extremely significant positive correlations were found between ev-ery two of the dry matter rates of above-ground parts （including leaf petioles, leaves and stems）, reducing sugar content and potato weight per plant. Assimilated product distributed more in stems and leaves than in storage roots before the 90th d in growing period. Photosynthetic capacity and net assimilation rate gradual y de-creased after the 90th d, but the assimilated product distributing to storage roots in-creased quickly and maximized in the 135th d. [Conclusion] Xuzishu 3 is a late ma-turing variety requiring more fertilizer, and the accumulation of anthocyanin fluctuates during the growth period of Xuzishu 3. So yield of Xuzishu 3 can be increased by applying more fertilizer and extending the growth period reasonably, meanwhile the anthocyanin content can be increased by means of control ing temperature, light, water and phytohormone within 60 d after planting.

Impacts of global warming on marine zooplankton

Global warming has been being a serious issue since 1980, and it impacts environment and biosphere. Here, we reviewed the physiological and ecological responses of marine zooplankton which is an important component of biosphere to the global warming. Much research on physiological changes in response to different temperature is given to discuss this issue. Furthermore, we focused on ecological changes of zooplankton to global warming and several indices such as abundance, biomass, biodiversity and biogeographic boundary are enumerated. Phenological changes of zooplankton were presented, followed by the prospects of this subject, viz. observing more functional groups, more concerning on zooplankton in tropical region and investigation on a species-level zooplankton system.

加工玉米收益好

河南沈丘县刘庄店镇杨老庄村的杨新林，在他家周边的玉米地里做上新文章，他把嫩玉米加工成保健食品，将青秸秆青贮氨化，这样每667平方米（1亩）地青玉米创产值7000多元。杨新林把不成熟的嫩玉米保鲜贮存下来，采用生物变性工艺将其加工成玉米面条、挂面、方便面、虾条等系列保健食品出售，因口感好，有滋补作用，很受消费者欢迎。

玉米面条机

由河南省鲁山县万通通机械制造有限公司研制的KYC型多功能玉米面条机，采用生物变性新工艺，原料经挤压可自动聚合，出机即熟，一次成型，不需蒸煮即可生产出金黄鲜亮、风味独特、韧度大、筋道滑爽的玉米面条。该机具有占地小、操作简单、功能多等特点，

Physiological and Biochemical Response of Artificial Wetland Plant under Electric Field

By measuring wetland plants chlorophyll content,malondialdehyde(MDA) content and superoxide dismutase(SOD) enzyme activity,the changes of wetland plant physiological characeristics under different power strength were studied,and the mechanism of electric field on plant physiological characteristics was analyzed to provide a theoretical basis for the pollutant removal ability strengthening of artificial wetland under electricfield.The results showed that compared with the control plants,low-intensity-voltage(1 V and 3 V) had no significant effect on the normal physiological and biochemical indexes of the plants,and the growth trend was better than the control group;with the voltage increasing,plant chlorophyll content,MDA content and SOD activity were greatly affected,indicating that plants were under strong oxidative stress,and the growth was damaged.Therefore,a suitable electric field could enhance the sewage treatment effect of constructed wetland.

Rheological and Structural Properties of Sea Cucumber Stichopus japonicus During Heat Treatment

Changes in tissue structure, rheological properties and water content of raw and heated sea cucumber meat were studied. Sea cucumber Stichopus japonicus was heated at 25℃, 70℃ and 100℃ water for 5 min. The structural changes were observed using a light microscope and the rheological parameters （rupture strength, adhesive strength and deformation） determined using a texture meter. Microscopic photograph revealed that the structural change of heated meat was greater than that of raw meat. The rupture strength, adhesive strength and deformation of raw meat were smaller than those of the heated meat. Meanwhile, rheological parameters showed positive correlation with heating temperature. These changes are mainly caused by thermal denaturation and gelatinization of collagen during heating. These changes were also evidenced in observations using a light microscope and differential scanning calorimetry.

Ubiquitination-mediated protein degradation and modification:an emerging theme in plant-microbe interactions

Post-translational modification is central to protein stability and to the modulation of protein activity. Various types of protein modification, such as phosphorylation, methylation, acetylation, myristoylation, glycosylation, and ubiquitination, have been reported. Among them, ubiquitination distinguishes itself from others in that most of the ubiquitinated proteins are targeted to the 26S proteasome for degradation. The ubiquitin/26S proteasome system constitutes the major protein degradation pathway in the cell. In recent years, the importance of the ubiquitination machinery in the control of numerous eukaryotic cellular functions has been increasingly appreciated. Increasing number of E3 ubiquitin ligases and their substrates, including a variety of essential cellular regulators have been identified. Studies in the past several years have revealed that the ubiquitination system is important for a broad range of plant developmental processes and responses to abiotic and biotic stresses. This review discusses recent advances in the functional analysis of ubiquitination-associated proteins from plants and pathogens that play important roles in plant-microbe interactions.

Effects of seasonal variations on soil microbial community composition of two typical zonal vegetation types in the Wuyi Mountains

Seasonal shifts play an important role in soil microbial community composition. This study examined the hypothesis that soil microbial community structure would vary with seasonal shifts in the Wuyi Mountains in Southeast China, and that two representative tree species （Castanopisi carlesii and Cunninghamia lanceolata） may have different soil microbial community composition. Phospholipids fatty acid analysis （PLFA） of seasonal shifts and was used to assess the effect vegetation types on soil microbial community structure. A total of 22 different PLFAs were identified from all the soil samples. The bacterial PLFAs accounted for 62.37% of the total PLFAs, followed by fungi （28.94%）, and the minimum was actinomycetes （6.41%）. Overall, the level of PLFAs in C. carlesii soil was greater than those in C. lanceolata soil, and significant differences were observed in some seasons. The amounts of total, bacteria, actinomycic and fungal PLFAs significantly changed with the seasons and followed a sequence order （summer 〉 autumn 〉 spring 〉 winter）. The bacteria/fungi PLFAs and G （＋）/G （-） PLFAs of two vegetation types also changed with the seasons and the ratios in summer and autumn were higher than those in spring and winter. The correlation analysis of microbial PLFAs and soil physicochemical properties showed that the total, bacteria, fungal, actinomycic, G （＋） and G （-） PLFAs were significantly positive correlation with TOC, TN, TP, TK and moisture content. We concluded that the seasonal shifts and vegetation types affect soil microbial community composition by changing the soil physicochemical properties.

Quantification of HBsAg:Basic virology for clinical practice

Hepatitis B surface antigen (HBsAg) is produced and secreted through a complex mechanism that is still not fully understood. In clinical fields, HBsAg has long served as a qualitative diagnostic marker for hepatitis B virus infection. Notably, advances have been made in the development of quantitative HBsAg assays, which have allowed viral replication monitoring, and there is an opportunity to make maximal use of quantitative HBsAg to elucidate its role in clinical fields. Yet, it needs to be underscored that a further understanding of HBsAg, not only from clinical point of view but also from a virologic point of view, would enable us to deepen our insights, so that we could more widely expand and apply its utility. It is also important to be familiar with HBsAg variants and their clinical consequences in terms of immune escape mutants, issues resulting from overlap with corresponding mutation in the P gene, and detection problems for the HBsAg variants. In this article, we review current concepts and issues on the quantification of HBsAg titers with respect to their biologic nature, method principles, and clinically relevant topics.

Bioleaching of chalcocite by mixed microorganisms subjected to mutation

Mixed microorganisms with elevated activity of chalcocite-leaching were screened by mutation methods. The original microorganisms collected from acid mine drainage of different sites were mixed and then treated with mutagens NO2^- , diethyl sulfate （DES）, UV and their combinations, respectively. Five groups of mixed microorganisms with much stronger ore-leaching ability were obtained by screening on the leaching media. Among them, group E of mixed microorganisms （treated with 1% DES for 60 min） with the best perfonnance on chalcocite-leaching, increases the content of Cu^2＋ by 101.4% in 20 d of leaching compared with the control culture. In addition, group E is more tolerant to Cu^2＋ in media than the control without mutation treatment. Analysis for the diversity of microbial clones indicates that half of operational taxonomic units （OTUs） in group E are Acidithiobacillus ferrooxidans. These observations suggest that group E might have potentials for industrial application.

Genetic variation of natural and cultured stocks of Paralichthys olivaceus by allozyme and RAPD

Population genetics of the left-eyed flounder, Paralichthys olivaceus, including natural and cultured stocks distributed in the coastal waters near Qingdao of eastern maritime China, was analyzed in allozyme and RAPD. The results showed that among total 29 gene loci of 15 isozymes, 9 and 7 were po- lymorphic in natural and cultured stocks, respectively. The status of genetic diversity in P. olivaceus is low in terms of polymorphic loci in chi-square test and genetic departure index of Hardy-Weinberg equi- librium. More alleles in IDHP, CAT, GDH and Ldh-C allozymes were found in the fish, which could be used as markers in assortive breeding and distinguishing stock, population or species evolution. Total 88 and 86 RAPD bands ranging from 200 to 2 500 bp were recognized individually in average of 7.8–8.0 bands per primer. The genetic diversity in cultured stock is lower than that in natural ones showing an ob- viously decreasing genetic divergence. Therefore, effective countermeasures must be taken to protect ge- netic resources of marine cultured fishes. The 2 markers have their own pros and cons. Combining the 2 markers to investigate the genetic variation of populations is suggested. The results provide basic data of this flounder and they are useful for studying genetic improvement and genetic resources of the fish.