适配体传感器结合便携式血糖仪定量检测赭曲霉毒素A的方法研究

目前大多数小分子毒素的定量检测方法仍需以实验室为基础或者定制设备,不能被公众广泛应用。研究开发了一种便携式适配体生物传感器,结合血糖仪用于赭曲霉毒素A(OTA)的定量检测。所开发的适配体生物传感器的线性范围是1×10-8~4×10-6mol/L,检出限6.7×10-9mol/L(2.69μg/kg);适配体生物传感器被成功地应用于婴幼儿米粉和羊草样品检测,回收率达84%~122%,表明所开发的适配体生物传感器为OTA的定量检测提供了一种新的方法,展现出良好的应用前景。     

基于侧向层析原理的赭曲霉毒素A快速检测试纸条的研制

针对霉菌毒素精准检测技术的开发对于保障食品安全至关重要。利用胶体金与赭曲霉毒素A单抗偶联物和赭曲霉毒素A-BSA偶联物（OTA-BSA）,开发了一种快速检测赭曲霉毒素A的方法。研究结果表明:①当OTA-BSA配制终质量浓度为4.8 g·L-1,质控线用羊抗鼠IgG配制终质量浓度为1.5 g·L-1,硝酸纤维素（NC）膜的包被量为1.0 μL·cm-1时呈现最清晰、最均匀的条带。②赭曲霉毒素A胶体金快速检测试纸条的灵敏度达到1.0 μg·L-1,检测时间仅为5 min,非常适合现场快速检测。该检测试纸条具有携带方便、灵敏度高、特异性强等优点。由于本方法检测时间短,灵敏度高,与传统的仪器和酶联免疫检测方法相比,在野外和临床检测中更具有推广应用价值。图5表1参12     

The role of technology in enhancing low resource agriculture in Africa

Traditional forms of farming, herding, and fishing are remarkably adapted to African conditions but these traditional approaches are being overtaken by modern pressures, particularly population growth. According to a report published by the Office of Technology Assessment (OTA), a nonpartisan analytical support agency of the U. S. Congress, one promising way to help African farmers and herders would be for development assistance organizations to focus more attention on the various forms of low-resource agriculture that predominate in Africa. In keeping with OTA's mission and primary audience, “Enhancing Agriculture in Africa: A Role for U. S. Development Assistance” (1988) is a policy-oriented synthesis of available technical information. The report provides Congress with a range of options that, if pursued, could help Africans enhance agriculture, increase their food security, and improve their lives. This paper is drawn from the larger OTA report, and it focuses on the role technology might play in enhancing low-resource agriculture. Readers should see the full assessment (OTA, 1988) for more information on policy considerations; the specific technologies mentioned; or a complete list of advisory panel members, workshops and participants, and commissioned papers. OTA's report comes at a critical time: for a variety of reasons—ranging from changing values to increased budget constraints—U. S. foreign assistance policy is undergoing a fundamental reevaluation. This review of the potential of low-resource agriculture, and options the United States might pursue to enhance this approach, was intended to aid in this reevaluation.     

赭曲霉素毒素A在咖啡中的产生及其对咖啡生产的影响研究

赭曲霉素毒素A(OTA)是一种分布较广的真菌毒素,广泛存在于谷物、其他植物性食品及相关产品和动物性食品中。研究表明,OTA对人和动物具有较强的肝毒性和肾毒性,并有致畸、致突变和致癌作用,OTA与人类健康的关系越来越受到人们重视。从文献上看,国外对咖啡中赭曲霉素毒素A含量测定进行了多方面的研究,国内研究较少。就咖啡中赭曲霉素毒素A的产毒菌株、产生时期以及咖啡加工过程中影响赭曲霉素毒素A含量的因素进行综述。     

基于量子点的赭曲霉毒素AsFLISA检测技术研究

建立了基于量子点标记技术的赭曲霉毒素A(Ochratoxin A,OTA)双抗夹心荧光免疫检测(sandwich fluorescence-linked immunosorbent assay,sFLISA)体系,包含多克隆包被抗体、生物素标记的多克隆检测抗体、量子点标记的链霉亲和素等,获得了sFLISA的最佳操作参数:包被抗体浓度2.5μg/mL,检测抗体稀释500倍,量子点标记链霉亲和素稀释100倍。该方法在OTA浓度3.125~125μg/L之间时,相对荧光强度和OTA浓度呈线性关系,回归方程为y=0.0206x+0.2018,R2=0.9924;加标回收率在90.1%~110.0%之间,变异系数均小于10%,能较好地进行赭曲霉毒素A的定量检测。     

U.S. postdocs. Report urges better treatment, status

For years, U.S. postdocs have been complaining about paltry salaries, lack of benefits, and lowly status. This week, a committee of the National Academies of Sciences and Engineering and the Institute of Medicine validated many of their complaints and lent its considerable weight to efforts to provide greater institutional support for postdocs. At the same time, however, the panel sidestepped two burning issues by explicitly declining to recommend a boost in postdoc salaries or take a position on whether to curtail the size of the postdoc workforce, which has more than doubled in the past 20 years to an estimated 52,000.     

一种求解线性规划的神经网络

提出了一种新的求解线性规划的神经网络及其有源跨导－Ｃ实现。其特点是结构简单，便于采用ＣＭＯＳ工艺集成。     

赭曲霉毒素产生菌筛选方法的对比与优选

【目的】探求一种能够快速、准确地筛选出赭曲霉毒素产生菌的分析方法,为赭曲霉毒素的检测与防治奠定基础。【方法】分别采用紫外荧光法、胶体金免疫试纸条法和高效液相色谱 (HPLC) 法,对分离自葡萄表面的189株霉菌产生赭曲霉毒素A（OTA）的能力进行分析,并对3种方法的鉴定结果进行比较。其中在紫外荧光法中,黑曲霉接种至可可浆培养基（CCA）培养,其他霉菌接种至察氏培养基（CA）培养,培养后能够产生荧光的菌株被认为是OTA产生菌。同时分别用高效液相色谱法（HPLC）和OTA胶体金试纸条对所有菌株培养物中的OTA进行检测。【结果】以HPLC检测结果为标准,用紫外荧光法对OTA产生菌初筛的假阳性率较高,假阴性率为0;胶体金免疫试纸条法用于筛选OTA产生菌的假阴性率为47.4%,假阳性率为0,适合于产毒量高的菌种筛选。【结论】用紫外荧光法作为OTA产生菌的初筛方法可以排除大部分非OTA产生菌,漏检率低,从而大大降低HPLC检测的工作强度和检测成本;将紫外荧光法和HPLC定量分析结合使用,可以快速、准确地分离到OTA产生菌;将紫外荧光法和胶体金免疫试纸条相结合,可以快速筛选OTA产量高的菌株,且该方法较为经济,对环境和人体的污染较小。     

Correction

In Deborah M. Barnes' article "AIDS commission bills proliferate" (News & Comment, 6 Mar., p. 1136), the AIDS commission proposals introduced by Senator Ted Stevens (R-AK) and Representative Jerry Lewis (R-CA) were incorrectly identified as being "along the lines of [those] recommended by the Institute of Medicine in its report ("Confronting AIDS") last fall." Instead, the IOM recommended the "establishment of a presidential or joint presidential and congressional commission that is independent and able to provide an ongoing critical assessment of needs-involving basic and clinical research, health care, public health, and other societal issues-as the AIDS epidemic develops," according to Roy Widdus, director of the IOM Division of International Health. The congressional advisory panel on AIDS, described in a bill introduced by Senator Pete Wilson (R-CA), incorrectly identified its potential membership. It would be open to IOM members, not exclude them, as the article indicates.     

Erratum

In the article "Reexamination of acoustic evidence in the Kennedy assassination" by the Committee on Ballistic Acoustics, National Research Council (8 Oct., p. 127), the probability given on page 130, column 1, line 17, was incorrectly printed. It should have been "P = .044."     

一种高阶全极点OTA-C高通滤波器设计方法

提出了一种高阶全极点ＯＴＡ－Ｃ高通滤波器的设计方法,用该方法对２－７阶最平坦型Ｂｕｔｔｅｒｗｏｒｔｈ高通滤波器进行了设计和ＰＳＰＩＣＥ模拟分析,结果与理论分析吻合,同时表明该方法的可行性。     

Fish Scales in a Sediment Core from Linsley Pond,Connecticut

In our paper "Mitochondrial self-duplication observed in vitro" [Science 124, 123 (20 July 1956)], the authors of two of the references were incorrectly given. The authors for reference 5 are E. P. Kennedy and A. L. Lehninger; the authors for reference 6 are J. W. Harman and M. Feigelson.     

Mosher case enters final phase

The appeals procedure begun by Steven Mosher after his 1983 expulsion from Stanford University has reached its final stage of review by university president Donald Kennedy, who asked the former student in a letter to clarify issues raised during the initial investigation of his conduct in China as a researcher. Mosher, dismissed from the graduate anthropology program for unethical behavior in the field, maintains that Stanford's actions were politically motivated, the result of pressure from mainland Chinese officials embarrassed by his reports on birth control and abortion practices. In order to protect Mosher's Chinese informants, the University has not made public the precise reasons for his expulsion.     

治疗奶牛乳房炎中药凝胶剂载药量及体外释药性研究

检测防治奶牛乳房炎中药凝胶剂的载药量及体外释药性.采用紫外分光光度法测定制剂载药量;采用转篮法进行处方的体外释药试验,用紫外分光光度法测定累积渗透量.紫外分光光度法测定中药复方凝胶剂载药量为21.52%,RSD为0.9%,中药复方凝胶剂累积释放曲线方程为y=2.923 9 Ln(x)+3.258,r2=0.993.采用...     

Melmon resigns Stanford chairmanship

The chairman of Stanford Medical School's department of medicine, Kenneth Melmon, has resigned his administrative position after receiving a letter of censure from Stanford president Donald Kennedy. A university ethics committee had found Melmon guilty of negligent scholarship after it was discovered that a textbook chapter authored by him contained unattributed material from a book he had earlier helped edit. Melmon maintained that permission to use the material and its proper attribution had been handled by his editor, but this later proved not to be the case. Stanford plans no further action in the matter, and Melmon will retain his professorship.     

Coral reef morphogenesis: a multidimensional model

Windward reef morphogenesis is a dynamic process directly controlled by the growth potential of dominant corals and coralline algae relative to wave energy and sea level rise. Moderate wave energy favors vertically rapid growth that is porous and uncemented; high wave energy favors slow but compact growth. Growth potentials of Caribbean and Indo-Pacific reefs are probably equivalent. Major differences are probably not due to biological or direct climatic factors but are in part related to differing patterns of sea level rise resulting from Holocene crustal adjustment. The nature and position of antecedent foundations developed by high interglacial and interstadial sea levels is especially critical and is largely controlled by regional tectonic factors, especially long-term subsidence.     

稻麦“双套”轻型简化栽培技术的研究及应用(Ⅰ) ——淮北地区稻棵套播麦的生育特点及栽培对策

系统论述了淮北地区稻棵套播麦播期提前,利于早发壮苗;群体大,高峰苗提前,利于足穗形成;幼苗发育进程提前,利于大穗形成的生育特点,及限制穗、粒、重三因素协调发展相关影响机理,提出了选用抗病品种、适期适量播种、“少食多餐”的平衡施肥方式、冬前保持地表土壤良好环境等配套轻型简化栽培技术,在生产实践中应用,取得了较好的经济效益和社会效益。     

Sex ratio manipulation and selection for attractiveness

Laboratory experiments performed on a monogamous estrildid, the zebra finch (Poephila guttata), indicate that sex ratio of offspring is affected by non-genetic markers (colored plastic leg bands) that vary in attractiveness to birds. Results suggest that natural selection favors individuals that produce offspring of the sex of the more attractive parent within a breeding pair.     

Fermi Prize: J. Robert Oppenheimer Named to Receive Annual AEC Award

The White House announced last week that J. Robert Oppenheimer would be the recipient of the Atomic Energy Commission's 1963 Fermi prize. The prize, which is accompanied by a $50,000 award, is given for "especially meritorious contribution to the development, use or control of atomic energy," and, as such, is strictly a recognition of scientific merit. This fact cannot be overstated. Nevertheless, because of the bitter and emotional controversy that surrounded the removal of Oppenheimer's security clearance in 1954, the Oppenheimer case has come to symbolize the dark hour to which nonconformity and scientific integrity were subjected in the McCarthy era. Oppenheimer's selection for the award is thus widely regarded as an effort by the scientific community and the Kennedy administration to right a long-standing wrong. The following account is an appreciation of Oppenheimer, written especially for Science by his colleague, Hans Bethe, of Cornell University.     

An unusual lightning flash at kennedy space center

A lightning flash that struck the 150-meter weather tower at Kennedy Space Center was studied by several research groups using varioul techniques. The flash had unusually large peak currents and a stepped leader of relatively short duration. The charged regions neutralized by the three return strokes were located within a horizontal layer between heights of about 6 and 8 kilometers, where environmental temperatures were about -10 degrees to -20 degrees C. The charge source for the first return stroke coincided with a vertical shaft of precipitation inferred to have been graupel or hail. Charge sources for subsequent strokes were near the edge of the detectable precipitation echo. The overall channel length was about 10 kilometers. A Vertically oriented intracloud discharge occurred after the three return strokes.