The effectiveness of a 0.05 blood alcohol concentration (BAC) limit for driving in the United States

The National Transportation Safety Board recently recommended that states establish a per se blood alcohol concentration (BAC) limit of 0.05 or lower for all drivers who are not already required to adhere to lower BAC limits in a national effort to reduce alcohol‐impaired driving. There is strong evidence for adopting this recommendation. A comprehensive review of the literature on BAC limits was conducted. The research indicates that virtually all drivers are impaired regarding at least some driving performance measures at a 0.05 BAC. The risk of being involved in a crash increases significantly at 0.05 BAC and above. The relative risk of being killed in a single‐vehicle crash with BACs of 0.05–0.079 is 7–21 times higher than for drivers at 0.00 BAC. Lowering the BAC limit from 0.08 to 0.05 has been a proven effective countermeasure in numerous countries around the world. Most Americans do not believe a person should drive after having two or three drinks in 2 hours. It takes at least four drinks for the average 170‐pound male to exceed 0.05 BAC in 2 hours (three drinks for the 137‐pound female). Most industrialized nations have established a 0.05 BAC limit or lower for driving. Progress in reducing the proportion of drivers in fatal crashes with illegal BACs has stalled over the past 15 years. Lowering the BAC limit for driving from the current 0.08 to 0.05 has substantial potential to reduce the number of people who drink and drive in the United States and get involved in fatal crashes.     

Malodorous volatile organic sulfur compounds: Sources,sinks and significance in inland waters

Volatile Organic Sulfur Compounds (VOSCs) are instrumental in global S-cycling and greenhouse gas production. VOSCs occur across a diversity of inland waters, and with widespread eutrophication and climate change, are increasingly linked with malodours in organic-rich waterbodies and drinking-water supplies. Compared with marine systems, the role of VOSCs in biogeochemical processes is far less well characterized for inland waters, and often involves different physicochemical and biological processes. This review provides an updated synthesis of VOSCs in inland waters, focusing on compounds known to cause malodours. We examine the major limnological and biochemical processes involved in the formation and degradation of alkylthiols, dialkylsulfides, dialkylpolysulfides, and other organosulfur compounds under different oxygen, salinity and mixing regimes, and key phototropic and heterotrophic microbial producers and degraders (bacteria, cyanobacteria, and algae) in these environs. The data show VOSC levels which vary significantly, sometimes far exceeding human odor thresholds, generated by a diversity of biota, biochemical pathways, enzymes and precursors. We also draw attention to major issues in sampling and analytical artifacts which bias and preclude comparisons among studies, and highlight significant knowledge gaps that need addressing with careful, appropriate methods to provide a more robust understanding of the potential effects of continued global development.     

Preterm birth in ancient Greece: a synopsis

This report refers to preterm birth in Ancient Greece based on mythological, historical and archeological data. The two antique goddesses, patronesses of labor and birth, Artemis and Eileithyia, cared for full-term, as well as preterm infants, among them for the mythological preterms Dionysos and Eurystheus. The former was rapidly transported by Hermes and received special care by the nymphs Hyades in a mountain cave with “incubator” properties. Historical data are related to the nine months duration of a normal pregnancy, to the definition of “Elitomina” (preterms), the lower limit of viability, the causes for preterm birth, the existence of small for gestational age infants and relevant causes, the physical examination of neonates and postpartum care. Lastly, excavations in Athens and Astypalaia discovered burials – in wells or pots – of preterm infants with gestational age 24–37 weeks.     

Niche adaptation and genome expansion in the chlorophyll d-producing cyanobacterium Acaryochloris marina

Acaryochloris marina is a unique cyanobacterium that is able to produce chlorophyll d as its primary photosynthetic pigment and thus efficiently use far-red light for photosynthesis. Acaryochloris species have been isolated from marine environments in association with other oxygenic phototrophs, which may have driven the niche-filling introduction of chlorophyll d. To investigate these unique adaptations, we have sequenced the complete genome of A. marina. The DNA content of A. marina is composed of 8.3 million base pairs, which is among the largest bacterial genomes sequenced thus far. This large array of genomic data is distributed into nine single-copy plasmids that code for >25% of the putative ORFs. Heavy duplication of genes related to DNA repair and recombination (primarily recA) and transposable elements could account for genetic mobility and genome expansion. We discuss points of interest for the biosynthesis of the unusual pigments chlorophyll d and α-carotene and genes responsible for previously studied phycobilin aggregates. Our analysis also reveals that A. marina carries a unique complement of genes for these phycobiliproteins in relation to those coding for antenna proteins related to those in Prochlorococcus species. The global replacement of major photosynthetic pigments appears to have incurred only minimal specializations in reaction center proteins to accommodate these alternate pigments. These features clearly show that the genus Acaryochloris is a fitting candidate for understanding genome expansion, gene acquisition, ecological adaptation, and photosystem modification in the cyanobacteria.     

Plasmonic probing of the adhesion strength of single microbial cells

Probing the binding between a microbe and surface is critical for understanding biofilm formation processes, developing biosensors, and designing biomaterials, but it remains a challenge. Here, we demonstrate a method to measure the interfacial forces of bacteria attached to the surface. We tracked the intrinsic fluctuations of individual bacterial cells using an interferometric plasmonic imaging technique. Unlike the existing methods, this approach determined the potential energy profile and quantified the adhesion strength of single cells by analyzing the fluctuations. This method provides insights into biofilm formation and can also serve as a promising platform for investigating biological entity/surface interactions, such as pathogenicity, microbial cell capture and detection, and antimicrobial interface screening.

Microorganisms can form biofilms, which are widely distributed and present on biotic and abiotic surfaces in natural, industrial, and medical settings (1–3). Initial bacterial adhesion to surfaces is the most crucial step in biofilm formation. The transition from initial weak, reversible interactions between a bacterium and a surface to irreversible adhesion involves complex physicochemical forces, including specific receptor-ligand forces, nonspecific hydrophobic, and electrostatic forces (4). Understanding and managing bacterial adhesion, especially at single-cell level, is a cross-disciplinary challenge (5, 6).While many methods have been developed for study of bacterial adhesion, most technologies are based on ensemble analysis of a vast population of cells, which washes out heterogeneity and microscopic information of single bacterial cells, and cannot measure the forces driving cell adhesion. Several methods are now available to study bacterial adhesion at the single-cell level (7–9). For example, atomic force microscopy (AFM) measures interfacial forces by mechanically moving one cell with the AFM probe (7, 10). Optical tweezers are another force spectroscopy method with an intense laser field that uses microbeads attached to the cell (11, 12). These methods measure one single cell at one time, thus having limited throughput. Additionally, they exert external forces on the cell and interfere with the intrinsic feature of bacterial adhesion.Here, we aim to probe the interfacial forces by measuring intrinsic fluctuations of bacteria attached to the surface using plasmonic interferometric imaging technique. Unlike AFM or optical tweezers, this method enabled us to perform high-throughput tracking of many single bacterial cells, to determine the potential energy profile for each bacterial cell and obtain the elastic parameters. To probe the tiny vertical fluctuations, we imaged the interferometric pattern of bacterial cells scattering the planar plasmonic wave propagating on the surface. The plasmonic scattering intensity was extremely sensitive to the vertical distance, allowing precise tracking of the fluctuations. From the fluctuation analyses, we obtained the interfacial energy profiles and elasticity of microbial binding, which were essential properties in understanding microbial adhesion. The derived binding constant can be used to quantify bacterial adhesion strength. Thus, the knowledge obtained can help understand biofilm formation and be used in the design of artificial surfaces to minimize or maximize bacterial adhesion.     

HPLC-ICP-MS测定泽泻、金银花、鸡血藤中可溶性价态砷及残留限度

目的 建立高效液相色谱-电感耦合等离子质谱(HPLC-ICP-MS)测定方法,分析金银花、泽泻、鸡血藤中4种不同价态砷,评估泽泻、金银花、鸡血藤中4种价态砷的残留情况,为制定相关残留限度提供依据。方法 采用0.05 mol·L^-1 EDTA溶液超声提取样品中可溶性砷,采用HPLC-ICP-MS分析样品中可溶性砷的形态。结果 As(Ⅲ)、DMA、MMA、As(Ⅴ)在5~200 μg·L^-1内线性良好,平均回收率(n=9)为105.1％~108.4％,方法检测限为0.01 mg·kg^-1。泽泻检出少量As(Ⅲ)、As(Ⅴ),金银花检出少量As(Ⅲ)、DMA、As(Ⅴ),鸡血藤则均未检出As(Ⅲ)、DMA、MMA、As(Ⅴ)。结论 该方法操作简便、结果准确、重复性好,能满足4种不同价态砷的残留限度分析。     

老年人下呼吸道嗜麦芽窄食单胞菌感染的临床分析

目的 探讨老年人下呼吸道嗜麦芽窄食单胞菌感染的危险因素及该菌对常用抗生素的敏感性。方法 分析40例老年下呼吸道嗜麦芽窄食单胞菌感染患者的临床资料，用K-B法测定该菌的体外药物敏感性。结果 全部患者均有基础疾病，其中慢性阻塞性肺疾病(COPD)20例(50．0％)，混合感染17例(42．5％)。均有抗生素应用史，70．0％的患者机体免疫功能低下，30．0％的患者曾有侵袭性治疗，平均住院时间达41．7d。临床症状及X线表现符合下呼吸道感染。药敏试验提示该菌呈现多重耐药，复方磺胺甲噁唑、环丙沙星、左氧氟沙星、阿米卡星、庆大霉素及氧氟沙星为较敏感抗生素。结论 老年下呼吸道嗜麦芽窄食单胞菌感染多发生于患有各种基础疾病、免疫功能低下及长期应用抗菌药物者，细菌耐药现象严重，诊断及治疗应根据病原学检查及药物敏感试验。