Bacillus cereus food intoxication and toxicoinfection

Bacillus cereus is one of the leading etiological agents of toxin-induced foodborne diseases. Its omnipresence in different environments, spore formation, and its ability to adapt to varying conditions and produce harmful toxins make this pathogen a health hazard that should not be underestimated. Food poisoning by B. cereus can manifest itself as an emetic or diarrheal syndrome. The former is caused by the release of the potent peptide toxin cereulide, whereas the latter is the result of proteinaceous enterotoxins (e.g., hemolysin BL, nonhemolytic enterotoxin, and cytotoxin K). The final harmful effect is not only toxin and strain dependent, but is also affected by the stress responses, accessory virulence factors, and phenotypic properties under extrinsic, intrinsic, and explicit food conditions and host-related environment. Infamous portrait of B. cereus as a foodborne pathogen, as well as a causative agent of nongastrointestinal infections and even nosocomial complications, has inspired vast volumes of multidisciplinary research in food and clinical domains. As a result, extensive original data became available asking for a new, both broad and deep, multifaceted look into the current state-of-the art regarding the role of B. cereus in food safety. In this review, we first provide an overview of the latest knowledge on B. cereus toxins and accessory virulence factors. Second, we describe the novel taxonomy and some of the most pertinent phenotypic characteristics of B. cereus related to food safety. We link these aspects to toxin production, overall pathogenesis, and interactions with its human host. Then we reflect on the prevalence of different toxinotypes in foods opening the scene for epidemiological aspects of B. cereus foodborne diseases and methods available to prevent food poisoning including overview of the different available methods to detect B. cereus and its toxins.     

拍出有创意的家庭肖像

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Triplex Crosslinking through Furan Oxidation Requires Perturbation of the Structured Triple‐Helix

Short oligonucleotides can selectively recognize duplexes by binding in the major groove thereby forming triplexes. Based on the success of our recently developed strategy for furan‐based crosslinking in DNA duplexes, we here investigated for the first time the use of the furan‐oxidation crosslink methodology for the covalent locking of triplex structures by an interstrand crosslink. It was shown that in a triplex context, although crosslinking yields are surprisingly low (to nonexistent) when targeting fully complementary duplexes, selective crosslinking can be achieved towards mismatched duplex sites at the interface of triplex to duplex structures. We show the promising potential of furan‐containing probes for the selective detection of single‐stranded regions within nucleic acids containing a variety of structural motifs.     

深度了解直方图

现在,在数码相机上都可以查看照片的直方图,但是直方图的意义是什么?怎么用它来检查照片的曝光呢?从下面这几页中你就能得到答案。     

关于高清视频的一切

<正>现在,越来越多的数码单反相机可以拍摄高清视频了,在这里我们将向你深入浅出地讲解如何开始你的单反视频之旅。拍摄高清视频10问①数码单反相机拍摄的视频有统一的格式吗?没有。如果你觉得照片的JPEG、RAW和