Overproduction, purification and characterization of GroES and GroEL from thermophilic Bacillus stearothermophilus

Abstract Biofilms containing diverse microflora were developed on bitumen-painted steel and glass tiles suspended in a chemostat model of a water distribution system. Escherichia coli , taken from a naturally occurring biofilm, was transformed with a plasmid containing the anaerobically induced nirB promoter fused to the lacZ reporter gene. The resulting transformant, PRB1, was introduced into the chemostat. After 7 and 13 days, an E. coli strain with an anaerobically induced Lac⁺ phenotype was present in the biofilm. Development of an episcopic differential interference contrast technique combined with UV fluorescence microscopy enabled the simultaneous visualization of E. coli in the biofilm using a fluorescent probe to detect expression of the gusA reporter gene and a lacZ fluorescent probe to monitor anaerobic expression of β-galactosidase from pnirB .     

General Visual and Contingent Thermal Cues Interact to Elicit Attraction in Female Aedes aegypti Mosquitoes

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Improvement of the contrast in cancer detection by autofluorescence bronchoscopy using a narrowband spectral violet excitation: A preliminary study

Autofluorescence (AF) bronchoscopy is a useful tool for early cancer detection. However, the mechanisms involved in this diagnosis procedure are poorly understood. We present a clinical autofluorescence imaging study to assess the depth of the principal contrast mechanisms within the bronchial tissue comparing a narrowband (superficial) and broadband (penetrating) violet excitation. Knowledge of this parameter is crucial for the optimization of the spectral and optical design of clinical diagnostic AF imaging devices. An intensity contrast improvement was observed with the narrowband excitation, suggesting that the heme absorption plays a key role in the AF contrast mechanism.     

Physicochemical characterization of ultrasmall superparamagnetic iron oxide particles (USPIO) for biomedical application as MRI contrast agents

Ultrasmall superparamagnetic iron oxide (USPIO) particles are maghemite or magnetite nanoparticles currently used as contrast agent in magnetic resonance imaging. The coatings surrounding the USPIO inorganic core play a major role in both the in vitro stability and, over all, USPIO's in vivo fate. Different physicochemical properties such as final size, surface charge and coating density are key factors in this respect. Up to now no precise structure--activity relationship has been described to predict entirely the USPIOs stability, as well as their pharmacokinetics and their safety. This review is focused on both the classical and the latest available techniques allowing a better insight in the magnetic core structure and the organic surface of these particles. Concurrently, this work clearly shows the difficulty to obtain a complete physicochemical characterization of USPIOs particles owing to their small dimensions, reaching the analytical resolution limits of many commercial instruments. An extended characterization is therefore necessary to improve the understanding of the properties of USPIOs when dispersed in an aqueous environment and to set the specifications and limits for their conception.     

Nanoparticles in modern medicine: state of the art and future challenges

Nanoparticles are materials with overall dimensions in the nanoscale, ie, under 100 nm. In recent years, these materials have emerged as important players in modem medicine, with clinical applications ranging from contrast agents in imaging to carriers for drug and gene delivery into tumors. Indeed, there are some instances where nanoparticles enable analyses and therapies that simply cannot be performed otherwise. However, nanoparticles also bring with them unique environmental and societal challenges, particularly in regard to toxicity. This review aims to highlight the major contributions of nanoparticles to modem medicine and also discuss environmental and societal aspects of their use.     

两种微泡造影剂评价输卵管通畅性的临床效果观察

目的:研究全氟丙烷人血白蛋白微球注射液(简称全氟丙烷白蛋白)在评价输卵管通畅性的临床应用效果。方法:96例不孕症患者分为两组,分别应用全氟丙烷白蛋白和Sono Vue进行子宫输卵管造影,实时观察造影剂在子宫、输卵管及盆腔显影情况,判断输卵管通畅性并记录病人即时疼痛指数。其中全氟丙烷白蛋白组中19例进行X线子宫输卵管造影。结果:两组超声造影结果对比,显影清晰率、图像质量及即时疼痛指数无统计学差异,一致性较好。全氟丙烷白蛋白Hy Co Sy组19例同时进行X线子宫输卵管造影,两种方法一致程度较好。结论:应用全氟丙烷白蛋白进行子宫输卵管超声造影可作为临床评价输卵管通畅性的一种有效方法。     

超声诊断结节性甲状腺肿合并甲状腺微小乳头状癌的价值

目的:探讨超声诊断结节性甲状腺肿合并甲状腺微小乳头状癌的价值。方法:2010年1月至2014年12月选择来我院进行诊治的结节性甲状腺肿患者80例,病理诊断为结节性甲状腺肿合并甲状腺微小乳头状癌30例(恶性组)和单纯结节性甲状腺肿50例(良性组),都进行常规二维超声、超声弹性成像和超声造影检查。结果:恶性组结节多呈现单发、内部低回声、钙化形态不规则特征,与良性组对比差异有统计学意义(P0.05)。恶性组病灶内的血流最小流速明显小于良性组(P0.05),阻力指数与搏动指数明显高于良性组(P0.05)。良性组弹性成像多为2~3分,恶性组多为4~5分,组间对比差异都有统计学意义(P0.05)。恶性组的造影剂平均通过时间明显少于对照组(P0.05),两组的显影时间、达峰时间、峰值强度对比差异无统计学意义(P0.05)。结论:常规超声诊断结节性甲状腺肿合并甲状腺微小乳头状癌的良恶性有一些特异性的征象,超声弹性成像与超声造影可为临床诊断提供补充,有助于提高甲状腺微小乳头状癌的诊断准确率。     

浅析新版《基本医疗保险药品目录》的制定

《基本医疗保险药品目录》是医保基金支付参保人员药品费用和强化医疗保险医疗服务管理的政策依据及标准。其根本目的是保证参保人员的合理用药需求,保障参保人员的合法权益,降低不合理用药支出。通过对新版《基本医疗保险药品目录》的新特点以及存在不足的分析,提出完善《基本医疗保险药品目录》制定的政策建议。     

液晶空间光调制器在生物光学显微中的应用

利用液晶空间光调制器(LCSLM)对光学显微中的成像光进行实时的相位/振幅调制,不仅可以实现各种传统的生物样品相位显微,而且能够以更复杂的相位调制方式,如螺旋相位滤波,得到新的显微图像。该方式已经和荧光显微、光镊技术结合,丰富了生物显微技术。     

The budding yeast Pichia pastoris has a novel Sec23p homolog

In Pichia pastoris, coat protein complex II (COPII) vesicles form at discrete transitional ER (tER) sites. Analyzing COPII coat proteins in this yeast will help to reveal the mechanisms of tER organization. Here, we show that like Saccharomyces cerevisiae, P. pastoris contains essential SEC23 and SEC24 genes, as well as the non-essential SEC24 homolog LST1. In addition, P. pastoris contains a novel non-essential SEC23 homolog that we have designated SHL23. The products of all four genes are concentrated at tER sites. Deletion of SHL23 does not disrupt tER morphology. As judged by two-hybrid analysis, Sec23p associates with both Sec24p and Lst1p, whereas Shl23p associates selectively with Lst1p. These results suggest that P. pastoris COPII vesicles contain an Shl23p/Lst1p complex that is absent in S. cerevisiae.