Tm3+-doped silica-glass fiber for ∼2-µm fiber laser.

Tm3+-doped silica-glass preforms were fabricated by the modified chemical vapor deposition process combined with the solution doping technique. Its spectroscopic properties were evaluated according to the detected absorption spectrum and the fluorescence spectrum. The calculated maximum emission cross section of Tm3+ ions in this core glass is 5.66×10-21 cm2, and the tested fluorescence lifetime is 544 µs at 1816 nm. According to the theory of Dexter and Forster, the cross-relaxation rate was calculated by the integral overlap of the absorption and emission cross sections. A double-cladding fiber with a core NA of 0.14 was prepared by high temperature drawing. A maximum 14.5-W fiber laser output centered at 2001 nm with a slope efficiency of 50.6% was obtained from a 4.5-m-length double-cladding fiber.

Wavelength-tunable all-fiber mode-locked laser based on supermode interference in a seven-core fiber.

A wavelength-tunable all-fiber mode-locked erbium-doped fiber laser has been proposed and realized by using a supermode interference filter (SMIF). The SMIF is fabricated by splicing a segment of seven-core fiber (SCF) to two standard single-mode fibers. Since two supermodes of the propagating light are excited in the SCF, the transmission spectrum of the SMIF shows a clean broadband comb-shape characteristic. By bending the SMIF in the proposed mode-locked laser, the output spectrum can be continuously tuned in a wavelength range up to 22 nm while keeping mode-locking operation. The self-starting laser produces 230 fs pulses with a spectral width of 14 nm.

Norovirus outbreaks in Fengtai District, Beijing, China, 2014.

Norovirus (NoV) is the most common cause of non-bacterial acute gastroenteritis (AGE) outbreaks worldwide. Eight NoV outbreaks in the Fengtai District of Beijing City, China, were identified in 2014. Samples were collected from the eight outbreaks, and 73 out of 119 samples from cases and 10 out of 59 samples from the close contacts were positive for NoVs. The genotypes were determined by sequencing analysis. Six different GII genotypes, including GII.2, 4, 6, 7, 8, 14, and 17 were found, and GII.4 was not the local major epidemic genotype in the present study. Enhanced strain surveillance is necessary for future NoV epidemics.

Outbreak of febrile illness caused by coxsackievirus A4 in a nursery school in Beijing, China.

BACKGROUND: Coxsackievirus A4 (CV-A4) is classified as human enterovirus A according to its serotype. CV-A4, an etiological agent of hand, foot, and mouth disease, affects children worldwide and can circulate in closed environments such as schools and hospitals for long periods. FINDINGS: An outbreak of febrile illness at a nursery school in Beijing, China, was confirmed to be caused by CV-A4. Phylogenetic analysis of the complete genome of the isolated strain showed that the virus belongs to the same cluster as the predominant CV-A4 strain in China. This outbreak was controlled by effective measures. CONCLUSIONS: The early identification of the pathogen and timely intervention may be the most critical factors in controlling an outbreak caused by CV-A4 in a preschool.

Chinese expert consensus on cone-beam CT-guided diagnosis, localization and treatment for pulmonary nodules.

Cone-beam computed tomography (CBCT) system can provide real-time 3D images and fluoroscopy images of the region of interest during the operation. Some systems can even offer augmented fluoroscopy and puncture guidance. The use of CBCT for interventional pulmonary procedures has grown significantly in recent years, and numerous clinical studies have confirmed the technology's efficacy and safety in the diagnosis, localization, and treatment of pulmonary nodules. In order to optimize and standardize the technical specifications of CBCT and guide its application in clinical practice, the consensus statement has been organized and written in a collaborative effort by the Professional Committee on Interventional Pulmonology of China Association for Promotion of Health Science and Technology.

Chinese expert consensus on interventional diagnosis and management of acquired digestive-respiratory tract fistulas (second edition).

Acquired digestive-respiratory tract fistulas occur with abnormal communication between the respiratory tract and digestive tract caused by a variety of benign or malignant diseases, leading to the alimentary canal contents in the respiratory tract. Although various departments have been actively exploring advanced fistula closure techniques, including surgical methods and multimodal therapy, some of which have gotten good clinical effects, there are few large-scale evidence-based medical data to guide clinical diagnosis and treatment. The guidelines update the etiology, classification, pathogenesis, diagnosis, and management of acquired digestive-respiratory tract fistulas. It has been proved that the implantation of the respiratory and digestive stent is the most important and best treatment for acquired digestive-respiratory tract fistulas. The guidelines conduct an in-depth review of the current evidence and introduce in detail the selection of stents, implantation methods, postoperative management and efficacy evaluation.

Effects of shuxuetong injection for cerebral infarction: A protocol for systematic review and meta-analysis.

BACKGROUND: Cerebral infarction (CI) is a common disease with high morbidity and disability. Shuxuetong (SXT) injection is a Chinese Materia Medica standardized product used in the treatment of CI. Currently, there is a lack of high-quality evidence to support the effectiveness and safety of SXT on patients with CI. This systematic review protocol aims at describing a meta-analysis to evaluate the efficacy of SXT for the treatment of CI. METHODS: We will search the databases of PubMed, MEDLINE, Embase, Cochrane Library Central Register of Controlled Trials, China national knowledge infrastructure database (CNKI), Wan fang database, Chongqing VIP information, and SinoMed from their inception to Jun 2020. Two reviewers will independently screen Randomized controlled trials of SXT for the treatment of CI. The meta-analysis will be conducted using RevMan V.5.3 software. RESULTS: The results of this study will be published in a peer-reviewed journal. CONCLUSION: The conclusion of our systematic review will provide evidence to judge whether SXT is an effective intervention for patients with CI. TRIAL REGISTRATION NUMBER: 10.17605/OSF.IO/3F6ZH.

Prevalence and factors associated with different pathogens of acute diarrhea in adults in Beijing, China.

INTRODUCTION: Only a small proportion of patients with diarrhea are diagnosed with laboratory tests in China, and most are diagnosed based on clinical symptoms. Therefore, understanding the prevalence of different diarrheal pathogens and their specific symptoms is important. METHODOLOGY: Data from a prospective study in Beijing of acute diarrhea and the related pathogens were used to study the association between different pathogen groups and the infected patients' characteristics. A total of 355 patients with acute diarrhea, clinically diagnosed with infectious or noninfectious diarrhea by general practitioners (GPs), were recruited from three districts. RESULTS: Different species of diarrheal pathogens were detected in 133 (37.5%) patients. The most prevalent pathogen was calicivirus (42.9%), followed by rotavirus (30.1%), Vibrio parahaemolyticus (13.5%), and Salmonella spp. (10.5%). The detection rates in patients diagnosed with infectious or noninfectious diarrhea by GPs did not differ significantly (c2 = 0.026, p = 0.873). Abdominal pain correlated negatively with viral pathogens, whereas nausea, living in the suburbs, and winter infection correlated positively with viral infection. Abdominal pain and leukocytosis were positively associated with bacterial infections, whereas winter infection correlated negatively with them. CONCLUSION: In this study, we found that the detection rates in patients diagnosed with infectious or noninfectious diarrhea by GPs was the same. We also revealed the improper prescription of antibiotics by GPs based simply on clinical diagnoses. A further analysis of diagnostic accuracy and methods is required to assist GPs in improving their diagnoses when insufficient laboratory tests are available and budgets are limited.

Outbreak of hand, foot, and mouth disease caused by coxsackievirus A6 in a Juku in Fengtai District, Beijing, China, 2015.

An outbreak of hand, foot, and mouth disease (HFMD) that occurred in a Juku in Fengtai District, Beijing, China, in 2015 was monitored by the China Information System for Disease Control and Prevention. Epidemiological investigation showed that 11 cases occurred from two classes in the preschool art training department in the Juku. Coxsackievirus A6 (CV-A6) was identified as the causative pathogen of the outbreak via sequences analysis of products of real-time reverse-transcription polymerase chain reaction (RT-PCR) and nested RT-PCR. Phylogenetic analysis showed that CV-A6 strains isolated in this study clustered with epidemic strains isolated in China since 2013. The outbreak ended quickly with effective measures. This event indicates that continuous surveillance of HFMD etiological agents other than enterovirus 71 and coxsackievirus A16 is necessary.

A report on the first outbreak of a single clone group A Streptococcus (emm-type 89) tonsillopharyngitis in China.

In 2012, 28 out of 140 staff working for a film crew in a Beijing movie and television base experienced a sudden onset of fever, sore throat, and/or tiredness, headache within the 24 hour period of July 26-27. All of the patients visited the hospital and were diagnosed as having tonsillopharyngitis. On July 28, 2012, a team of Centers for Disease Control and Prevention staff arrived and initiated an outbreak investigation. Pharyngeal swabs were obtained from patients for microbiologic analysis. All isolates of the outbreak were analyzed for toxin-genes and drug-resistance genes by polymerase chain reaction, and were performed for the emm typing and pulsed-field gel electrophoresis typing. On July 30, 2012, Group A Streptococcus was isolated from eight of the 16 throat swab specimens obtained on site. These isolates were found to have the same genotype emm 89. This is the first report to identify Group A Streptococcus emm type-89 as a cause of tonsillopharyngitis in Beijing, China.