Hollow-core terahertz Bragg waveguide based on a helical support structure.

A helical structural support scheme is proposed to mechanically support dielectric layers in a hollow-core terahertz Bragg waveguide by means of an axially rotating wrap-around strip structure. The helical-strip supported waveguide samples are fabricated using 3D printing technology, and the waveguide samples are experimentally tested using a terahertz time-domain spectroscopy system. The results show that choosing a suitable helix period can obtain loss characteristics close to those of an ideal Bragg waveguide, with a low transmission loss of less than 0.

A portable all-in-one microfluidic device with real-time colorimetric LAMP for HPV16 and HPV18 DNA point-of-care testing.

Screening for high-risk human papillomavirus (HPV) infection is one of the most important preventative measures for cervical cancer. However, fast, convenient, and low-cost HPV detection remains challenging, especially in resource-limited settings. Here, we report a portable all-in-one device (PAD) for point-of-care testing (POCT) for HPV16 and HPV18 DNA in cervical swabs.

Diagnostic test of bioimpedance-based neural network algorithm in early cervical cancer.

Background: Colposcopy is a critical component of cervical cancer screening services, but the accuracy of colposcopy varies greatly due to the lack of standardized training for colposcopists and pathologists. Thus, to improve the accuracy of colposcopy in the detection of cervical lesions intelligently is urgent. Here, we explored the sensitivity and specificity of a bioimpedance-based neural network algorithm in distinguishing normal and precancerous cervical tissues.

Dysbiosis of vaginal microbiota associated with persistent high-risk human papilloma virus infection.

Background: The status of vaginal microbiota in persistent high-risk human papilloma virus (HR-HPV) infection is unclear. The present work aimed to identify the vaginal microbiota of persistent HPV infection and explore the possible underlying microbiota factors.

Methods: A total of 100 women were recruited in this study, of which 28 presented HR-HPV persistent infection (P group), 30 showed clearance of any subtype of HR-HPV (C group), and 42 had no history of any HR-HPV infection (NC group).

Molecular characterization of Coxsackievirus A16 strains isolated from children with severe hand, foot, and mouth disease in Yunnan, Southwest China, during 2009-2015.

Coxsackievirus A16 (CV-A16) commonly causes mild symptoms, but severe diseases, such as aseptic meningitis, encephalitis, and even fatal cases, have been reported. Thirteen CV-A16 strains were isolated from patients with severe hand, foot, and mouth disease in Yunnan, Southwest China, from 2009 to 2015. Subgenotype B1a and B1b of CV-A16 were predominantly circulating the region with B1b the predominant strain in recent years.

Prevalence of hepatitis B virus and hepatitis C virus in patients with human immunodeficiency virus infection in Central China.

Co-infection of hepatitis B virus (HBV) and/or hepatitis C virus (HCV) with human immunodeficiency virus (HIV) has an adverse effect on liver disease progression. This study investigated the prevalence of HBV and/or HCV co-infection in HIV-infected patients in Central China. A total of 978 HIV-infected patients from Hunan Province were enrolled.

Positive regulation of flhDC expression by OmpR in Yersinia pseudotuberculosis.

OmpR has been demonstrated to negatively regulate the expression of the flagellar master operon flhDC in a wide variety of bacterial species. Here we report the positive regulation of flhDC expression by OmpR in Yersinia pseudotuberculosis. A sigma(70)-dependent promoter was identified by primer extension analysis and an active region with two conserved OmpR-binding sites around the flhDC promoter was confirmed.

[Relationship between flagella-dependent motility and biofilm in bacteria--a review].

Motility was considered to be closely related with biofilm formation positively for a long time because the ability of biofilm formation would be decreased in the motility-defective bacteria. Moreover,the results of defective mutants of flagella and some other regulated proteins suggested that the relationship between motility and biofilm was diverse in different bacteria. Factors other than motility could influence the development of biofilms as well.

OmpR positively regulates urease expression to enhance acid survival of Yersinia pseudotuberculosis.

Yersinia pseudotuberculosis is an enteric bacterium which must overcome the acidic stress in host organs for successful colonization, but how this bacterium survives in acidic conditions remains largely unknown. In the present study, the importance of OmpR in acid survival of Y. pseudotuberculosis YpIII was confirmed by the fact that mutation of ompR (strain DeltaompR) greatly reduced cell survival at pH 4.

Functional characterization of FlgM in the regulation of flagellar synthesis and motility in Yersinia pseudotuberculosis.

We describe here the functional characterization of the flgM gene in Yersinia pseudotuberculosis. Direct interaction of FlgM with the alternative sigma factor sigma(28) (FliA) was first confirmed. A conserved region in the C-terminus of FlgM was found which included the sigma(28) binding domain.

The flhDC gene affects motility and biofilm formation in Yersinia pseudotuberculosis.

The flagella master regulatory gene flhDC of Yersinia pseudotuberculosis serotype III (YPIII) was mutated by deleting the middle region and replaced by a tetracycline resistant gene, and the subsequent mutant strain named YPIIIDeltaflhDC was obtained. Swimming assay showed that the swimming motility of the mutant strain was completely abolished. The promoter region of the flagella second-class regulatory gene fliA was fused with the lux box, and was conjugated with the mutant and the parent strains respectively for the first cross.