Forced vibration frequency response for a permanent magnetic planetary gear

The time and frequency forced responses for the permanent magnetic planetary gear drive were computed and analyzed. The influence of air gap between sun gear and planetary gear to frequency forced responses is discussed. Results show that the changes of air gap have obvious effects on the low frequency vibration amplitude of elements. When air gap is too large or too small, it will seriously affects the dynamic performance of the system. So, selecting rational system structure parameters is very important, which can avoid system elements generating larger vibration

Aqueous Solution-Based Fe₃O₄ Seed-Mediated Route to Hydrophilic Fe₃O₄–Au Janus Nanoparticles

Hydrophilic Fe₃O₄–Au Janus nanoparticles have been synthesized through a facile aqueous solution-based Fe₃O₄ seed-mediated chemical reduction route, where Au nanoparticles can be <i>in situ</i> formed on surfaces of PVP-modified Fe₃O₄ nanoparticles by adopting the well-known citrate reduction route. The diameter of Au nanoparticles can be controllably tuned in the range of 3–12 nm by simply changing the initial molar ratio between sodium citrate and auric acid. The as-fabricated hydrophilic Fe₃O₄–Au Janus nanoparticles have shown excellent catalytic performance with high catalytic activity and recyclability due to the synergetic effect between Au and Fe₃O₄ nanoparticles

Shifts in the Antibiotic Susceptibility, Serogroups, and Clonal Complexes of <i>Neisseria meningitidis</i> in Shanghai, China: A Time Trend Analysis of the Pre-Quinolone and Quinolone Eras

<div><p>Background</p><p>Fluoroquinolones have been used broadly since the end of the 1980s and have been recommended for <i>Neisseria meningitidis</i> prophylaxis since 2005 in China. The aim of this study was to determine whether and how <i>N</i>. <i>meningitidis</i> antimicrobial susceptibility, serogroup prevalence, and clonal complex (CC) prevalence shifted in association with the introduction and expanding use of quinolones in Shanghai, a region with a traditionally high incidence of invasive disease due to <i>N</i>. <i>meningitidis</i>.</p><p>Methods and Findings</p><p>A total of 374 <i>N</i>. <i>meningitidis</i> isolates collected by the Shanghai Municipal Center for Disease Control and Prevention between 1965 and 2013 were studied. Shifts in the serogroups and CCs were observed, from predominantly serogroup A CC5 (84%) in 1965–1973 to serogroup A CC1 (58%) in 1974–1985, then to serogroup C or B CC4821 (62%) in 2005–2013. The rates of ciprofloxacin nonsusceptibility in <i>N</i>. <i>meningitidis</i> disease isolates increased from 0% in 1965–1985 to 84% (31/37) in 2005–2013 (<i>p</i> < 0.001). Among the ciprofloxacin-nonsusceptible isolates, 87% (27/31) were assigned to either CC4821 (n = 20) or CC5 (<i>n</i> = 7). The two predominant ciprofloxacin-resistant clones were designated China^{CC4821-R1-C/B} and China^CC5-R14-A. The China^{CC4821-R1-C/B} clone acquired ciprofloxacin resistance by a point mutation, and was present in 52% (16/31) of the ciprofloxacin-nonsusceptible disease isolates. The China^CC5-R14-A clone acquired ciprofloxacin resistance by horizontal gene transfer, and was found in 23% (7/31) of the ciprofloxacin-nonsusceptible disease isolates. The ciprofloxacin nonsusceptibility rate was 47% (7/15) among isolates from asymptomatic carriers, and nonsusceptibility was associated with diverse multi-locus sequence typing profiles and pulsed-field gel electrophoresis patterns. As detected after 2005, ciprofloxacin-nonsusceptible strains were shared between some of the patients and their close contacts. A limitation of this study is that isolates from 1986–2004 were not available and that only a small sample of convenience isolates from 1965–1985 were available.</p><p>Conclusions</p><p>The increasing prevalence of ciprofloxacin resistance since 2005 in Shanghai was associated with the spread of hypervirulent lineages CC4821 and CC5. Two resistant meningococcal clones China^{CC4821-R1-C/B} and China^CC5-R14-A have emerged in Shanghai during the quinolone era. Ciprofloxacin should be utilized with caution for the chemoprophylaxis of <i>N</i>. <i>meningitidis</i> in China.</p></div

<i>gyrA</i> alleles in 51 ciprofloxacin-nonsusceptible <i>N</i>. <i>meningitidis</i> strains.

<p>^a<i>gyrA</i> alleles were defined in this study based on nucleotides 115–639 of the <i>gyrA</i> gene.</p><p>^bIsolates assigned to any CC are shown with CC, while the isolates unable to be assigned are shown with ST.</p><p>^cAdditional alterations in ParE: R5, H495N; R6, A450V; R11, A443T and D480N.</p><p>New, unable to assign in the PubMLST database.</p><p><i>gyrA</i> alleles in 51 ciprofloxacin-nonsusceptible <i>N</i>. <i>meningitidis</i> strains.</p

Case fatality rate of reported cases of meningococcal disease in Shanghai from 1950 to 2013.

<p>The trend was analyzed using regression splines (red dotted line).</p

Dendrogram of 51 ciprofloxacin-nonsusceptible <i>N</i>. <i>meningitidis</i> strains from patients and carriers in Shanghai, China, 2005–2013, constructed using pulsed-field gel electrophoresis—NheI.

<p>The clones China^{CC4821-R1-C/B} and China^CC5-R14-A are indicated in grey shading, with the relatedness values marked on the roots. ●The PFGE data for the Anhui outbreak strain 053442 were obtained from PulseNet China. §Clonal dissemination between patients and their close contacts was observed. †Imported cases. NG, non-groupable.</p

Guidelines for the diagnosis, treatment, prevention and control of infections caused by carbapenem-resistant gram-negative bacilli

The dissemination of carbapenem-resistant Gram-negative bacilli (CRGNB) is a global public health issue. CRGNB isolates are usually extensively drug-resistant or pandrug-resistant, resulting in limited antimicrobial treatment options and high mortality. A multidisciplinary guideline development group covering clinical infectious diseases, clinical microbiology, clinical pharmacology, infection control, and guideline methodology experts jointly developed the present clinical practice guidelines based on best available scientific evidence to address the clinical issues regarding laboratory testing, antimicrobial therapy, and prevention of CRGNB infections. This guideline focuses on carbapenem-resistant Enterobacteriales (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA). Sixteen clinical questions were proposed from the perspective of current clinical practice and translated into research questions using PICO (population, intervention, comparator, and outcomes) format to collect and synthesize relevant evidence to inform corresponding recommendations. The grading of recommendations, assessment, development and evaluation (GRADE) approach was used to evaluate the quality of evidence, benefit and risk profile of corresponding interventions and formulate recommendations or suggestions. Evidence extracted from systematic reviews and randomized controlled trials (RCTs) was considered preferentially for treatment-related clinical questions. Observational studies, non-controlled studies, and expert opinions were considered as supplementary evidence in the absence of RCTs. The strength of recommendations was classified as strong or conditional (weak). The evidence informing recommendations derives from studies worldwide, while the implementation suggestions combined the Chinese experience. The target audience of this guideline is clinician and related professionals involved in management of infectious diseases