三元(碱-表面活性剂-聚合物)复合驱油藏采出水微生物群落特征

与水驱技术相比,向油藏中注入碱、表面活性剂和聚合物(简称三元复合驱,ASP)能大幅提高石油采收率,但这些驱油剂对油藏中微生物多样性与群落结构的影响尚亟待阐明,这对油田水质管理与腐蚀控制均具有的重要意义. 本研究采用高通量测序技术解析了大庆油田ASP油藏4口油井采出水中的微生物多样性与群落结构. 结果表明: ASP油藏采出水的pH高达9.65. 采出水中微生物Shannon多样性指数为2.00～3.56,采出井间菌群多样性存在差异. 在门、纲、属分类水平上,变形菌门(85.5%～98.3%)、γ-变形菌纲(83.7%～97.8%)、栖碱菌属(51.8%～82.5%)是绝对优势菌群. 共检测到12个属的潜在硫化氢产生菌,以硫磺单胞菌属丰度最高(0.4%～7.4%). 与已发表的水驱油藏研究结果相比,三元复合驱油藏采出水微生物群落组成独特,呈嗜/耐碱趋势,其多样性偏低,群落结构更单一.     

植保网络应用技术初步研究

ASP(Active Server Pages动态服务器网页）是Microsoft公司1997年推出的,WINDOWS面向WEB特征的,功能强大而成熟一种技术。2000年以来,笔对其应用于植保网络化、可视化与自动化方面作了一些探讨与开发,建立了我省第一个植保专业网站,网址www.fizb.com。阐述了植保在互联网上的初步应用研究。     

上海昆虫多样性信息系统的设计与建立

利用Access＋ASP＋IIs技术,建立了集害虫信息管理与昆虫编目数据库为一体的上海昆虫多样性管理信息系统。用户可以通过浏览器访问http：／／www．insects．cn进行检索和查询。本文详细阐述了该系统的构建方法,并就目前昆虫多样性信息管理系统建设中存在的问题作了评述。     

Caspase-3 immunohistochemical expression is a marker of apoptosis,increased grade and early recurrence in intracranial meningiomas

Caspase-3 is the ultimate executioner caspase that is essential for the nuclear changes associated with apoptosis. We investigated caspase-3 immunohistochemical expression in 58 primary intracranial meningiomas, using one monoclonal antibody detecting both precursor and cleaved caspase-3 (CPP32) and a second recognizing only the cleaved activated form (ASP175). Caspase-3 expression was analyzed in relation to baseline apoptosis—as illustrated by the expression of anti-single stranded DNA (ss-DNA), the antiapoptotic protein bcl-2, proliferation indices (Ki-67, PCNA, topoisomerase IIa, mitosin C), hormonal status (estrogen, progesterone, androgen receptors), standard clinicopathological parameters and patients’ disease-free survival. Caspase-3 immunostaining was observed in 62% of cases for CPP32 and in 24% for ASP175. In both instances, the labeling index (LI) was significantly correlated with ss-DNA LI (p=0.038 and p=0.018). CPP32 but not ASP175 LI positively correlated with the mitotic index (p=0.001) and PCNA LI (p=0.004). Both CPP32 and ASP175 LIs were increased in nonbenign meningiomas (p<0.0001 and p=0.0035 respectively). In univariate and multivariate survival analyses, caspase-3 predicted meningioma recurrence, independently affecting disease-free survival (p=0.011 and p=0.047 respectively for CPP32; p<0.0001 and p=0.012 respectively for ASP175). Caspase-3 may prove to be a useful predictor of early recurrence in a group of neoplasms characterized by the frequent discordance between histology and clinical behavior.     

Effect of storage on amnesic shellfish poisoning (ASP) toxins in king scallops (Pecten maximus)

Since 1998, king scallops (Pecten maximus) obtained from Scottish offshore sites have been monitored for domoic acid (DA) and epi-domoic acid (epi-DA), the principal toxic compounds associated with amnesic shellfish poisoning (ASP). The presence of these toxins in king scallops harvested from Scottish waters at concentrations exceeding the current regulatory limit (20 μg g⁻¹ shellfish flesh) is a recurrent event. However, little information was available to determine the effects that different storage conditions experienced during sample transportation to the monitoring laboratory may have on the toxin concentrations, which are subsequently detected. Furthermore, the stability of DA and epi-DA in the solvents (methanol:water (1:1, v/v) and citric acid buffer (0.5 M, pH 3.2)) routinely used for their extraction from shellfish has not previously been assessed. Results from this study demonstrate that when king scallop samples were stored for 2–3 days at 12 °C, a significantly higher toxin concentration was detected in the gonad than when samples were stored at 4 °C and analysed within 48 h. This implies that monitoring programmes must consider transport and storage conditions between harvest and analysis. Stability studies showed rapid decomposition of DA and epi-DA in aqueous methanol extracts while DA and epi-DA seem acceptably stable when stored refrigerated in citrate buffer.     

Predicting allosteric switches in myosins.

The sequences of several members of the myosin family of molecular motors are evaluated using ASP (Ambivalent Structure Predictor), a new computational method. ASP predicts structurally ambivalent sequence elements by analyzing the output from a secondary structure prediction algorithm. These ambivalent sequence elements form secondary structures that are hypothesized to function as switches by undergoing conformational rearrangement. For chicken skeletal muscle myosin, 13 discrete structurally ambivalent sequence elements are identified. All 13 are located in the heavy chain motor domain. When these sequence elements are mapped into the myosin tertiary structure, they form two compact regions that connect the actin binding site to the adenosine 5'-triphosphate (ATP) site, and the ATP site to the fulcrum site for the force-producing bending of the motor domain. These regions, predicted by the new algorithm to undergo conformational rearrangements, include the published known and putative switches of the myosin motor domain, and they form plausible allosteric connections between the three main functional sites of myosin. The sequences of several other members of the myosin I and II families are also analyzed.     

X-ray structure of Na-ASP-2, a pathogenesis-related-1 protein from the nematode parasite, Necator americanus, and a vaccine antigen for human hookworm infection

Human hookworm infection is a major cause of anemia and malnutrition of adults and children in the developing world. As part of on-going efforts to control hookworm infection, The Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective L3 larval stages of the parasite, including a family of pathogenesis-related (PR) proteins known as the Ancylostoma-secreted proteins (ASPs). A novel crystal structure of Na-ASP-2, a PR-1 protein secreted by infective larvae of the human hookworm Necator americanus, has been solved to resolution limits of 1.68 A and to an R-factor of 17% using the recombinant protein expressed in and secreted by Pichia pastoris. The overall fold of Na-ASP-2 is a three-layer alphabetaalpha sandwich flanked by an N-terminal loop and a short, cysteine-rich C terminus. Our structure reveals a large central cavity that is flanked by His129 and Glu106, two residues that are well conserved in all parasitic nematode L3 ASPs. Na-ASP-2 has structural and charge similarities to chemokines, which suggests that Na-ASP-2 may be an extra-cellular ligand of an unknown receptor. Na-ASP-2 is a useful homology model for NIF, a natural antagonistic ligand of CR3 receptor. From these modeling studies, possible binding modes were predicted. In addition, this first structure of a PR-1 protein from parasitic helminths may shed light on the molecular basis of host-parasite interactions.     

Biotechnological significance of toxic marine dinoflagellates

Dinoflagellates are microalgae that are associated with the production of many marine toxins. These toxins poison fish, other wildlife and humans. Dinoflagellate-associated human poisonings include paralytic shellfish poisoning, diarrhetic shellfish poisoning, neurotoxic shellfish poisoning, and ciguatera fish poisoning. Dinoflagellate toxins and bioactives are of increasing interest because of their commercial impact, influence on safety of seafood, and potential medical and other applications. This review discusses biotechnological methods of identifying toxic dinoflagellates and detecting their toxins. Potential applications of the toxins are discussed. A lack of sufficient quantities of toxins for investigational purposes remains a significant limitation. Producing quantities of dinoflagellate bioactives requires an ability to mass culture them. Considerations relating to bioreactor culture of generally fragile and slow-growing dinoflagellates are discussed. Production and processing of dinoflagellates to extract bioactives, require attention to biosafety considerations as outlined in this review.