喷气燃料中污染微生物检测方法概况

微生物污染不仅降解喷气燃料,还严重威胁储存和飞行安全。喷气燃料中污染微生物的检测是有效治理微生物污染的前提。基于此,本文将喷气燃料中污染微生物检测方法分为传统法、分析生物学法以及分子生物学方法,并对三种方法优缺点进行了详细介绍。最后对喷气燃料中污染微生物检测方法进行了展望。

口服伊曲康唑在人角质层抗念珠菌活性的研究

目的通过测定伊曲康唑(口服给药)在人角质层的抗念珠菌活性,探索一种与体内环境相似的药敏试验新方法。方法将21例健康志愿者用数字表法随机分为2组,分别口服伊曲康唑200 mg,1次/d(Qd)×7 d和200 mg,2次/d(B id)×7 d。于服药前、服药后1、4、7、10、14、21、28、35 d制备皮肤角质层剥离条,将白念珠菌、光滑念珠菌、近平滑念珠菌和热带念珠菌孢子接种其上,培养48 h,过碘酸-雪夫(PAS)染色,采用角质层真菌计量生物学分析法,并用计算机辅助图像分析测定真菌覆盖的面积。结果2种剂量的伊曲康唑在皮肤角质层对4种念珠菌均有明显的抗真菌活性。2种剂量的伊曲康唑对白念珠菌、近平滑念珠菌和热带念珠菌的抗真菌效果的差异无统计学意义(P>0.05);而对于光滑念珠菌,伊曲康唑200 mg B id×7 d在人角质层的抗真菌活性明显优于200 mg Qd×7 d(P<0.01)。结论角质层真菌计量生物学分析法是介于体外试验与体内疗效之间的一种新方法的有效尝试。

Measurement of Serum Total and Free Prostate-Specific Antigen for Breast Cancer Diagnosis in Women

Objective: To investigate the diagnostic value and the relationship between the clinicopathological features and the levels of total and free prostate-specific antigen (PSA) in women with breast cancer.Methods: Using the microparticle enzyme immunoassay system, we measured the concentrations of these markers in the sera of 85 women with breast cancer and in 30 healthy women.Rseults: The lowest detection level for both markers was 0.01 ng/ml. Free PSA levels were significantly higher in women with breast cancer than that in healthy women (P<0.05). The percentage of free PSA predominant subjects was 37.6% in breast cancer patients and 3.3% in healthy women. Cut-off values were 0.36 ng/ml for total PSA and 0.02 ng/ml for free PSA. In women with breast cancer, total PSA positivity was 23.5% and free PSA positivity was 27.1%. Compared to negatives, total PSA positive patients had a higher percentage of lymph node involvement tumours (P>0.05). However, patients with predominant free PSA had a higher percentage of early stage than patients with predominant PSA-ACT.Conclusion: Although the sensitivity of free PSA predominance is low (37.6%) in distinguishing women with breast cancer from healthy women, its specificity is high (97.0%).Free PSA predominance tends to be present in early stage tumours. These findings may indicate clinical significance of preoperative measurement of serum total and free PSA in women with breast cancer.

The auxin concentration in sixteen Chinese marine algae

The author determined the occurrence of indole-3-acetic acid in sixteen Chinese marine algae collected from the east coast of China with fluorescence spectrophotometry (FS) and wheat coleop- tile bioanalysis methods (WCB). The concentration of indole-3-acetic acid (IAA) presented was from 1.1–46.9 ng/g Fw (fresh weight) with FS and 5.3–110.2 ng/g Fw with WCB. The results by the two meth- ods were in the orders of 10-3–103 ng/g Fw reported previously from multiple references.

Methodology of the Relationship between Bioethics, Philosophy, and Law

One can distinguish three levels in the integrative unity of knowledge and norms （assessments）, which is termed bioethics. The first level is theoretical. It is connected with the facts and truths. The second level deals with establishing of certain standards and rules of conduct, with the monitoring of their implementation and the assessment of the results of implementation/violation of norms. The third level is associated with individual behavior, formed on the basis of relevant knowledge （or lack of it, as is evident from the table）, and the rules governing its application. Theoretical Bioethics is an integral part of Philosophy---the practical Bioethics is directly related to Law and applied Bioethics deals with the personal standards of specific behavior in concrete situations. Social need for regulatory control of any activity with living entities has led to rapid development of practical Bioethics, while its philosophical content developed more slowly. This creates a conflict of norms and values, hampering the adoption of individual decisions now in the field of applied Bioethics. Deontologization of Bioethics can lead to the fact that it will lose its philosophical content and become a specific area of Law. This, in turn, leads to the dehumanization of Bioethics. It is therefore necessary to conduct a methodological analysis of the relationship of Philosophy, Bioethics and Law, the results of which will focus the researchers on the synchronization of the axiological, praxeological and ethical components of scientific research in order to preserve the intellectual integrity of Bioethics.

Phylogeny and evolutionary history of the silkworm

The silkworm,Bombyx mori,played an important role in the old Silk Road that connected ancient Asia and Europe.However,to date,there have been few studies of the origins and domestication of this species using molecular methods.In this study,DNA sequences of mitochondrial and nuclear loci were used to infer the phylogeny and evolutionary history of the domesticated silkworm and its relatives.All of the phylogenetic analyses indicated a close relationship between the domesticated silkworm and the Chinese wild silkworm.Domestication was estimated to have occurred about 4100 years ago(ya),and the radiation of the different geographic strains of B.mori about 2000 ya.The Chinese wild silkworm and the Japanese wild silkworm split about 23600 ya.These estimates are in good agreement with the fossil evidence and historical records.In addition,we show that the domesticated silkworm experienced a population expansion around 1000 ya.The divergence times and the population dynamics of silkworms presented in this study will be useful for studies of lepidopteran phylogenetics,in the genetic analysis of domestic animals,and for understanding the spread of human civilizations.

Denitrification Rates and Their Controlling Factors in Streams of the Han River Basin with Different Land-Use Patterns

Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the presented study, we investigated the controlling factors of denitrification rates within the streams of the Han River Basin, Korea, with different land-use patterns, in order to enhance the effectiveness of water resource management strategies. Ten watersheds were classified into three land-use patterns （forest, agriculture and urban） using satellite images and geographic information system techniques, and in-situ denitrification rates were determined using an acetylene blocking method. Additionally, sediment samples were collected from each stream to analyze denitrifier communities and abundance using molecular approaches. In-situ denitrification rates were found to be in the order of agricultural streams （289.6 mg N20-N m-2 d-1） 〉 urban streams （157.0 mg N20-N m-2 d-1） 〉 forested streams （41.9 mg N20-N m-2 d-l）. In contrast, the average quantity of denitrifying genes was the lowest in the urban streams. Genetic diversity of denitrifying genes was not affected by watershed land-use pattern, but exhibited stream-dependent pattern. More significance factors were involved in denitrification in the sites with higher denitrification rates. Multiple linear regression analysis revealed that clay, dissolved organic carbon and water contents were the main factors controlling denitrification rate in the agricultural streams, while dissolved organic carbon was the main controlling factor in the urban streams. In contrast, temperature appeared to be the main controlling factor in the forested streams.

Improved picoliter-sized micro-reactors for high-throughput biological analysis

High-throughput pyrosequencing,carried out in millions of picoliter-sized reactors on a fiber-optic slide,is known for its longer read length.However,both optical crosstalk(which reduces the signal-to-noise ratio of CCD images)and chemical retention adversely affect the accuracy of chemiluminescence determination,and ultimately decrease the read length and the accuracy of pyrosequencing results.In this study,both titanium and oxidized aluminum films were deposited on the side walls and upper faces of micro-reactor slides to enhance optical isolation;the films reduced the inter-well crosstalk by one order of magnitude.Subsequently,chemical retention was shown to be caused by the lower diffusion coefficient of the side walls of the picolitersized reactors because of surface roughness and random pores.Optically isolated fiber-optic slides over-coated with silicon oxide showed smoother surface morphology,resulting in little chemical retention;this was further confirmed with theoretical calculations.Picoliter-sized micro-reactors coated with titanium-silicon oxide films showed the least inter-well optical crosstalk and chemical retention;these properties are expected to greatly improve the high-throughput pyrosequencing performance.

Gold nanolabels and enzymatic recycling dual amplification-based electrochemical immunosensor for the highly sensitive detection of carcinoembryonic antigen

A sensitive electrochemical immunoassay system for the detection of a protein tumor biomarker through a dual amplified strategy was reported. Firstly, this protocol involves in the electropolymerization of o-aminobenzoic acid (o-ABA) on a glass carbon electrode (GCE). Subsequently, capture anti-CEA (Abl) is covalently linked to poly(o-ABA) (PAB) film, via N-(3-dimethylamminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), and N-hydroxysulfosuccinimid sodium salt (NHS) activation of the carboxyl groups and surface blocking with ethanolamine. Later, the target, carcinoembryonic antigen (CEA), is sandwiched between an electrode surface confined Ab1 and the alkaline phosphatase-labeled signal anti-CEA antibodies conjugated with gold nanoparticles (Ab2-ALP-AuNP bioconjugates). The dual biocatalytic signal amplification for CEA monitoring is achieved by coupling the numerous enzymes loaded on the AuNPs with redox-recycling of the enzymatic products in the presence of the secondary enzyme and the corresponding substrate. The novel dramatic signal amplification strategy, exhibits a good linearity at the studied concentration range from 0.005 to 50 ng mL-1 towards CEA with a detection limit of 2 pg mL-1 (S/N=3). There is a 5-100-fold improvement in detection limit compared to other similar studies. The developed dual signal amplified strategy shows good selectivity, regeneration, stability and acceptable reproducibility. Therefore, the signal amplification approach holds great potential applications in detection of ultra-trace protein biomarkers.