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排序方式: 共有256条查询结果,搜索用时 31 毫秒
31.
Detection of enteroviruses in treated drinking water 总被引:4,自引:0,他引:4
This study deals with the routine monitoring of drinking water for the presence of enteroviruses, over a period of 1 year. A rapid and simple method was employed for the simultaneous detection and typing of enteroviruses in large-volume water samples. This included an integrated cell culture/nested PCR approach, followed by restriction enzyme analysis. The two drinking water supplies studied were derived from acceptable quality surface water sources using treatment processes, which conform to international specifications for the production of safe drinking water. Enteroviruses (predominantly coxsackie B viruses) were detected in 11% and 16% of the drinking water samples from two treatment plants, respectively. This study confirms that acceptable water quality indicators do not necessarily reflect the virus content of drinking water. 相似文献
32.
Steinmetz NF Evans DJ Lomonossoff GP 《Chembiochem : a European journal of chemical biology》2007,8(10):1131-1136
The use of viral nanoparticles (VNPs) as building blocks for material fabrication has received particular attention in recent years. In earlier studies we showed the applicability of native gel electrophoresis in an agarose matrix as a useful method for the characterization of chemically modified VNPs. Here, we extend these studies and analyze the observed band pattern of intact Cowpea mosaic virus (CPMV) VNPs in agarose gels and show the applicability of native agarose gels for monitoring interparticle linkage of thiol-containing CPMV mutant particles. In addition, we report a protocol that allows the introduction of acetate-protected thiols to CPMV by means of a chemical reaction (rather than genetic modification). The advantage of this approach is that, by incorporating protected thiol groups, the formation of disulfide bonds leading to interparticle linkage is prevented. The resulting thiol-modified CPMV-SH(n) particles are stable, and following deprotection, the introduced thiols are reactive and can be labeled with thiol-selective reagents. They therefore provide a useful additional building block in the CPMV toolbox. 相似文献
33.
34.
Ngumbi E Eigenbrode SD Bosque-Pérez NA Ding H Rodriguez A 《Journal of chemical ecology》2007,33(9):1733-1747
Volatiles from potato plants (Solanum tuberosum L.) infected with Potato leaf roll virus (PLRV) attract and arrest the principal vector of PLRV, the green peach aphid, Myzus persicae (Sulzer), more strongly than volatiles from non-infected plants. The total concentration of volatiles detectable in the headspace
of PLRV-infected plants is greater than that in the headspace of non-infected controls, and the relative composition is altered.
To determine the basis of the aphid response to PLRV-infection-induced volatiles from potato, behavioral bioassays were conducted.
We measured arrestment of aphids by individual components, by synthetic blends of these, and by a naturally occurring blend
by using an emigration rate bioassay, and quantified observations of the behavior of individual aphids. The components tested
were those elevated at least twofold in response to PLRV infection. Before conducting the behavioral bioassays, electroantennograms
confirmed the electrophysiological responses of aphids to the components of the blend. For bioassays, individual compounds
or blends were tested by applying them in solution to paper strips at concentrations designed to mimic those present in the
headspace of the plants. All bioassays were conducted by placing aphids on fine-mesh screening positioned above treated paper
strips. Arrestment was measured by placing groups of 30 aphids directly over the treated strips and counting the number moving
away at 10-min intervals for 50 min. Among the individual compounds tested, only β-pinene was a mild arrestant. The other
compounds did not elicit significant changes in arrestment or behavior at a range of physiologically relevant concentrations.
In contrast, synthetic blends that mimicked the concentration and composition present in headspace of PLRV-infected potato
plants arrested aphids significantly more strongly than blends mimicking volatiles from the headspace of non-infected plants.
The naturally occurring blend collected from headspace of PLRV-infected plants also arrested M. persicae more strongly than the blend collected from headspace of non-infected plants. Aphid behavior was quantified by directly observing
individual aphids and recording their activities during a 5-min period on screening above strips treated with test materials.
Few differences in time budgets were observed among aphids exposed to individual components, but synthetic blends and trapped
headspace volatiles from PLRV-infected plants resulted in significantly less time spent walking by aphids than synthetic blends
and trapped headspace from non-infected controls. Our results indicate that arrestment of M. persicae by PLRV-infected plants requires the blend of volatile organic compounds released by these plants and is not produced in
response to a single compound. 相似文献
35.
36.
In recent years, a number of surveys have indicated a significant escalation in reported incidents of computer crime and abuse. This rise is coupled with increasing attention to the issue in the mass media, which has the effect of heightening public perceptions of problems with IT and may represent a barrier to the adoption of technologies such as the Internet and World Wide Web.This paper considers the effects of computer crime and draws upon the results of a survey conducted to assess public attitudes and awareness of the issue. With the mass media playing an important role in shaping individual opinions, this survey considered the effect that the reporting of incidents has upon public perceptions and understanding of computer crime and abuse.The survey results show that individual awareness of computer crime and abuse is high and that the majority of respondents perceive it to be a problem. However, the views expressed regarding the seriousness of the different types of abuse (and the potential motivations for them) were more variable. In addition, awareness of abuse is more widespread than knowledge of the associated legislation that may be used to prevent and punish it. The results also revealed the significant potential for media reports to influence opinions in this area, highlighting the importance of a responsible attitude in order to foster the information society. 相似文献
37.
Biological therapies have changed the face of oncology by targeting cancerous cells while reducing the effect on normal tissue. This publication focuses mainly on new therapies that have contributed to the advances in treatment of certain malignancies. Immunotherapy, which has repeatedly proven to be a breakthrough therapy in melanoma, as well as B-ALL therapy with CAR T cells, are of great merit in this progress. These therapies are currently being developed by modifying bispecific antibodies and CAR T cells to improve their efficiency and bioavailability. Work on improving the therapy with oncolytic viruses is also progressing, and efforts are being made to improve the immunogenicity and stability of cancer vaccines. Combining various biological therapies, immunotherapy with oncolytic viruses or cancer vaccines is gaining importance in cancer therapy. New therapeutic targets are intensively sought among neoantigens, which are not immunocompromised, or antigens associated with tumor stroma cells. An example is fibroblast activation protein α (FAPα), the overexpression of which is observed in the case of tumor progression. Universal therapeutic targets are also sought, such as the neurotrophic receptor tyrosine kinase (NTRK) gene fusion, a key genetic driver present in many types of cancer. This review also raises the problem of the tumor microenvironment. Stromal cells can protect tumor cells from chemotherapy and contribute to relapse and progression. This publication also addresses the problem of cancer stem cells resistance to treatment and presents attempts to avoid this phenomenon. This review focuses on the most important strategies used to improve the selectivity of biological therapies. 相似文献
38.
生物传感器是1种将生物信号转化为电信号的传感装置,迄今已经有50多年的发展历史。生物传感器从早期通过检测代谢产物的第1代生物传感器发展到可以实现直接电化学的第3代生物传感器。由于自身出色的性能,生物传感器得到了广泛的应用,各种新的技术也层出不穷。在食品分析领域中,生物传感器被广泛用于农兽药残留、真菌毒素、微生物及病毒以及其他污染物的检测。本文梳理了近年来生物传感器在食品检测中的广泛应用,并对未来生物传感技术在食品中发展作出了展望。 相似文献
39.
Hwa-Jung Choi Jae-Hyoung Song Young-Joon Ahn Seung-Hwa Baek Dur-Han Kwon 《European Food Research and Technology》2009,228(6):945-950
The antiviral activity of the cell-free supernatants (CFS) containing the metabolites of five yogurts fermented under anaerobic
conditions with Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus plantarum, Streptococcus thermophilus and Bifidobacterium bifidum, respectively, was initially evaluated against seven RNA viruses using virus-induced cytopathic effects reduction method,
while comparing that of De Man, Rogosa, and Sharpe (MRS) broths containing metabolites fermented with the same bacteria. All
the CFS of yogurt showed high antiviral activity against seven RNA viruses, while the CFS of MRS broth exhibited similar or
lower antiviral activity. Each CFS of yogurt and MRS broth showed no cytotoxicity with normal morphology in Vero or MDCK cells.
Furthermore, CFS of each yogurt was more effective than that of MRS broth against the three enteroviruses and CFS of yogurt
containing metabolites fermented with L. plantarum exhibited strong anti-influenza virus activity among that of the other yogurt and MRS broth. Therefore, CFS of the yogurt
containing metabolites fermented with probiotic bacteria showed high potential to be used for developing fermented milk-based
foods or drugs. 相似文献
40.
Al-Gharabli SI Shah ST Weik S Schmidt MF Mesters JR Kuhn D Klebe G Hilgenfeld R Rademann J 《Chembiochem : a European journal of chemical biology》2006,7(7):1048-1055
A method for the parallel solid-phase synthesis of peptide aldehydes has been developed. Protected amino acid aldehydes obtained by the racemization-free oxidation of amino alcohols with Dess-Martin periodinane were immobilized on threonyl resins as oxazolidines. Following Boc protection of the ring nitrogen to yield the N-protected oxazolidine linker, peptide synthesis was performed efficiently on this resin. A peptide aldehyde library was designed for targeting the SARS coronavirus main protease, SARS-CoV M(pro)(also known as 3CL(pro)), on the basis of three different reported binding modes and supported by virtual screening. A set of 25 peptide aldehydes was prepared by this method and investigated in inhibition assays against SARS-CoV M(pro). Several potent inhibitors were found with IC(50) values in the low micromolar range. An IC(50) of 7.5 muM was found for AcNSTSQ-H and AcESTLQ-H. Interestingly, the most potent inhibitors seem to bind to SARS-CoV M(pro) in a noncanonical binding mode. 相似文献