猪血丙种球蛋白的制备工艺研究

报道了运用低温乙醇与明矾吸附、碳吸附相结合，制备猪血丙种球蛋白的工艺，纯度可达９５％以上，回收率达５７％，其他各项指标均达卫生部制定的《中国生物制品规程》标准。     

耐用品动态古诺模型的建立及分析

依据耐用品的市场容量随着时间发生变化的特点,对多个企业同时博弈的动态古诺模型进行修正,建立了适用于耐用品市场的动态古诺模型,并得到新的产量均衡解.通过与合作情形下的最优产量解的比较与分析,得到非合作情形下的产量均衡解和合作情形下的最优产量解都随着阶段数的增加而单调下降,并且前者依旧劣于后者等结论.     

SELF-ORGANIZING MODELLING IN EXPERIMENTA SYSTEMS ANALYSIS

ＳＥＬＦ－ＯＲＧＡＮＩＺＩＮＧＭＯＤＥＬＬＩＮＧＩＮＥＸＰＥＲＩＭＥＮＴＡＳＹＳＴＥＭＳＡＮＡＬＹＳＩＳＪ．Ａ．Ｍｕｌｌｅｒ（ＩｎｓｔｉｔｕｔｅｆｏｒＴｅｃｈｎｏｌｏｇｙａｎｄＥｃｏｎｏｍｙＤｒｅｓｄｅｎ，Ｇｅｒｍａｎｙ）Ａｂｓｔｒａｃｔ：Ｓｅｖｅｒ...     

无成本协同效应的横向兼并行为

基于寡头垄断竞争行业,研究了企业横向兼并的获利性和社会福利问题。结果表明:在企业兼并成垄断被排除的情况下,若兼并企业在其内部实施两阶段错开竞争且兼并企业与未参与兼并的企业之间进行Cournot竞争,则一次有利可图的先置兼并行为会引发系列兼并行为。当系列兼并行为发生后,兼并企业可能会陷入"囚徒困境",社会福利与初始的、完全分散的Cournot竞争市场相比可能增加。     

Decision-making at the surface of the intact or barrier disrupted skin: potential applications for vaccination or therapy

The skin is a highly accessible organ and constitutes an active immunological site. Both these properties make this surface an attractive route for what promises to be a cost-effective, simple, practical and needle-free delivery of vaccines and immunomodulators. Less obvious is the fact that the state of the skin barrier can influence quantitative and qualitative aspects of antigen-specific immune responses. The everyday decision-making at the skin epithelium concerns the choice between the induction of an immune response and the establishment of a state of non-responsiveness (tolerance). This decision is influenced by various factors such as the dose, the route (intact vs barrier-disrupted skin), the cytokine microenvironment and the nature of the antigenic stimulus. By increasing our understanding of how immune responses are regulated in the epidermis we can envisage the development of immunisation protocols aimed at eliciting a protective immune response or inducing tolerance, with direct applications to preventive or therapeutic vaccination, respectively.Received 29 November 2004; received after revision 2 February 2005; accepted 22 February 2005     

Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars

The majority of volcanic products on Mars are thought to be mafic and effusive. Explosive eruptions of basic to ultrabasic chemistry are expected to be common, but evidence for them is rare and mostly confined to very old surface features. Here we present new image and topographic data from the High Resolution Stereo Camera that reveal previously unknown traces of an explosive eruption at 30 degrees N and 149 degrees E on the northwestern flank of the shield volcano Hecates Tholus. The eruption created a large, 10-km-diameter caldera approximately 350 million years ago. We interpret these observations to mean that large-scale explosive volcanism on Mars was not confined to the planet's early evolution. We also show that glacial deposits partly fill the caldera and an adjacent depression. Their age, derived from crater counts, is about 5 to 24 million years. Climate models predict that near-surface ice is not stable at mid-latitudes today, assuming a thermo-dynamic steady state. Therefore, the discovery of very young glacial features at Hecates Tholus suggests recent climate changes. We show that the absolute ages of these very recent glacial deposits correspond very well to a period of increased obliquity of the planet's rotational axis.     

Evidence from the Mars Express High Resolution Stereo Camera for a frozen sea close to Mars' equator

It is thought that the Cerberus Fossae fissures on Mars were the source of both lava and water floods two to ten million years ago. Evidence for the resulting lava plains has been identified in eastern Elysium, but seas and lakes from these fissures and previous water flooding events were presumed to have evaporated and sublimed away. Here we present High Resolution Stereo Camera images from the European Space Agency Mars Express spacecraft that indicate that such lakes may still exist. We infer that the evidence is consistent with a frozen body of water, with surface pack-ice, around 5 degrees north latitude and 150 degrees east longitude in southern Elysium. The frozen lake measures about 800 x 900 km in lateral extent and may be up to 45 metres deep--similar in size and depth to the North Sea. From crater counts, we determined its age to be 5 +/- 2 million years old. If our interpretation is confirmed, this is a place that might preserve evidence of primitive life, if it has ever developed on Mars.     

Cycles in fossil diversity

It is well known that the diversity of life appears to fluctuate during the course of the Phanerozoic, the eon during which hard shells and skeletons left abundant fossils (0-542 million years ago). Here we show, using Sepkoski's compendium of the first and last stratigraphic appearances of 36,380 marine genera, a strong 62 +/- 3-million-year cycle, which is particularly evident in the shorter-lived genera. The five great extinctions enumerated by Raup and Sepkoski may be an aspect of this cycle. Because of the high statistical significance we also consider the contributions of environmental factors, and possible causes.