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Objectives: This study aimed to describe the lineage-specific transmissibility and epidemiological migration of Mycobacterium tuberculosis in China. Methods: We curated a large set of whole-genome sequences from 3204 M. tuberculosis isolates, including thousands of newly sequenced genomes, and applied a series of metrics to compare the transmissibility of M. tuberculosis strains between lineages and sublineages. The countrywide transmission patterns of major lineages were explored. Results: We found that lineage 2 (L2) was the most prevalent lineage in China (85.7%), with the major sublineage 2.2.1 (80.9%), followed by lineage 4 (L4) (13.8%), which comprises major sublineages 4.2 (1.5%), 4.4 (6.2%) and 4.5 (5.8%). We showed evidence for frequent cross-regional spread and large cluster formation of L2.2.1 strains, whereas L4 strains were relatively geographically restricted in China. Next, we applied a series of genomic indices to evaluate M. tuberculosis strain transmissibility and uncovered higher transmissibility of L2.2.1 compared with the L2.2.2 and L4 sublineages. Phylogeographic analysis showed that southern, eastern, and northern China were highly connected regions for countrywide L2.2.1 strain spread. Conclusions: The present study provides insights into the different transmission and migration patterns of the major M. tuberculosis lineages in China and highlights that transmissible L2.2.1 is a threat to tuberculosis control.

ABSTRACTObjectives We investigated the genetic diversities and lineage-specific transmission dynamics of multidrug-resistant tuberculosis (MDR-TB), with the goal of determining the potential factors driving the MDR epidemics in China.Methods We curated a large nationwide Mycobacterium tuberculosis (M. tuberculosis) whole genome sequence data set, including 1313 MDR strains. We reconstructed the phylogeny and mapped the transmission networks of MDR-TB across China using Bayesian inference. To identify drug-resistance variants linked to enhanced transmissibility, we employed ordinary least-squares (OLS) regression analysis.Result The majority of MDR-TB strains in China belong to lineage 2.2.1. Transmission chain analysis has indicated that the repeated and frequent transmission of L2.2.1 plays a central role in the establishment of MDR epidemic in China, but no occurrence of a large predominant MDR outbreak was detected. Using OLS regression, the most common single nucleotide polymorphisms (SNPs) associated with resistance to isoniazid (katG_p.Ser315Thr and katG_p.Ser315Asn) and rifampicin (rpoB_p.Ser450Leu, rpoB_p.His445Tyr, rpoB_p.His445Arg, rpoB_p.His445Asp, and rpoB_p.His445Asn) were more likely to be found in L2 clustered strains. Several putative compensatory mutations in rpoA, rpoC, and katG were significantly associated with clustering. The eastern, central, and southern regions of China had a high level of connectivity for the migration of L2 MDR strains throughout the country. The skyline plot showed distinct population size expansion dynamics for MDR-TB lineages in China.Conclusion MDR-TB epidemic in China is predominantly driven by the spread of highly transmissible Beijing strains. A range of drug-resistance mutations of L2 MDR-TB strains displayed minimal fitness costs and may facilitate their transmission.

Previous studies on students' conceptions of learning science (COLS) have focused primarily on formal environments. In these studies, students' COLS were positively associated with their approaches to and outcomes for science learning. However, little research has been conducted to explore students' conceptions of learning science in informal environments (COLSIE), despite its importance to students' academic achievement. To fill this research gap, this study qualitatively and quantitatively explored Chinese primary school students' COLSIE. First, in Study I, interview data gathered from a group of 80 students were analysed using the phenomenographic method, and ten hierarchical categories of COLSIE emerged (e.g., communicating and explaining). Based on these categories, a survey was developed and distributed to another group of 414 students in Study II. Exploratory factor analysis was conducted to validate the survey, which revealed nine factors matching the ten categories except for the initial categories of applying and understanding. This study also revealed the commonalities and uniqueness of COLSIE in comparison with students' COLS in formal environments. The findings suggested that informal science learning experiences may strengthen students' impressions of science practices. Science educators are encouraged to provide their students with opportunities to engage with science practices in informal environments.

Brain vascular calcification is a prevalent age-related condition often accompanying neurodegenerative and neuroinflammatory diseases. The pathogenesis of large-vessel calcifications in peripheral tissue is well studied, but microvascular calcification in the brain remains poorly understood. Here, we report that elevated platelet-derived growth factor BB (PDGF-BB) from bone preosteoclasts contributed to cerebrovascular calcification in male mice. Aged male mice had higher serum PDGF-BB levels and a higher incidence of brain calcification compared with young mice, mainly in the thalamus. Transgenic mice with preosteoclast-specific Pdgfb overexpression exhibited elevated serum PDGF-BB levels and recapitulated age-associated thalamic calcification. Conversely, mice with preosteoclast- specific Pdgfb deletion displayed diminished age-associated thalamic calcification. In an ex vivo cerebral microvascular culture system, PDGF-BB dose-dependently promoted vascular calcification. Analysis of osteogenic gene array and single-cell RNA-Seq (scRNA-Seq) revealed that PDGFBB upregulated multiple osteogenic differentiation genes and the phosphate transporter Slc20a1 in cerebral microvessels. Mechanistically, PDGF-BB stimulated the phosphorylation of its receptor PDGFR[beta] (p- PDGFR[beta]) and ERK (p-ERK), leading to the activation of RUNX2. This activation, in turn, induced the transcription of osteoblast differentiation genes in PCs and upregulated Slc20a1 in astrocytes. Thus, bone-derived PDGF-BB induced brain vascular calcification by activating the p-PDGFR[beta]/p-ERK/RUNX2 signaling cascade in cerebrovascular cells., Introduction It has long been recognized that vascular calcification and osteoporosis often coexist in the aging population and in individuals with chronic diseases such as diabetes, dyslipidemia, hyperphosphatemia, and chronic [...]

Galvanic corrosion behavior of 5083 alloy/H62 brass couple in 3.5 wt.% NaCl solution under 0, 0.2 and 0.4 T magnetic field were studied by microstructure observation, immersion test and electrochemical measurement. The mixed potential theory was used to estimate the galvanic current density and the mixed potential of the galvanic corrosion between 5083 alloy and H62 brass. The results indicated that magnetic field can impede the corrosion of 5083 alloy, and accelerate the corrosion process of H62 brass. The effect of magnetic field on corrosion of these two alloys increased as the intensity rising. Magnetic field can reduce the galvanic corrosion sensibility and corrosion rate of 5083 alloy/H62 brass couple. With increase of magnetic field intensity, the inhibition effect of magnetic field on galvanic corrosion of the couple increased. The effects of magnetic field on the galvanic corrosion performance of the couple and the corrosion behavior of 5083 alloy and H62 brass were due to the appearance of magnetohydrodynamic flow. The mixed potential theory has a certain accuracy to estimate the Ecouple and icouple values in this paper.

Abstract Background Tuberculosis (TB) is one of the main infectious diseases that seriously threatens global health, while diagnostic delay (DD) and treatment dramatically threaten TB control. Methods Between 2005 and 2017 in Shandong, China, we enrolled pulmonary tuberculosis (PTB) patients with DD. DD trends were evaluated by Joinpoint regression, and associations between PTB patient characteristics and DD were estimated by univariate and multivariate logistic regression. The influence of DD duration on prognosis and sputum smear results were assessed by Spearman correlation coefficients. Results We identified 208,822 PTB cases with a median DD of 33 days (interquartile range (IQR) 18–63). The trend of PTB with DD declined significantly between 2009 and 2017 (annual percent change (APC): − 4.0%, P = 0.047, 2009–2013; APC: − 6.6%, P = 0.001, 2013–2017). Patients aged > 45 years old (adjusted odds ratio (aOR): 1.223, 95% confidence interval (CI) 1.189–1.257, 46–65 years; aOR: 1.306, 95% CI 1.267–1.346, > 65 years), farmers (aOR: 1.520, 95% CI 1.447–1.596), and those with a previous treatment history (aOR: 1.759, 95% CI 1.699–1.821) were prone to developing long DD (> 30 days, P

Objectives: To explore the role of fibrocytes in the recurrence and calcification of fibrous epulides. Methods: Different subtypes of fibrous epulides and normal gingival tissue specimens were first collected for histological and immunofluorescence analyses to see if fibrocytes were present and whether they differentiated into myofibroblasts and osteoblasts upon stimulated by transforming growth factor‐β1 (TGF‐β1). Electron microscopy and elemental analysis were used to characterize the extracellular microenvironment in different subtypes of fibrous epulides. Human peripheral blood mononuclear cells (PBMCs) were subsequently isolated from in vitro models to mimic the microenvironment in fibrous epulides to identify whether TGF‐β1 as well as the calcium and phosphorus ion concentration in the extracellular matrix (ECM) of a fibrous epulis trigger fibrocyte differentiation. Results: Fibrous epulides contain fibrocytes that accumulate in the local inflammatory environment and have the ability to differentiate into myofibroblasts or osteoblasts. TGF‐β1 promotes fibrocytes differentiation into myofibroblasts in a concentration‐dependent manner, while TGF‐β1 stimulates the fibrocytes to differentiate into osteoblasts when combined with a high calcium and phosphorus environment. Conclusions: Our study revealed fibrocytes play an important role in the fibrogenesis and osteogenesis in fibrous epulis, and might serve as a therapeutic target for the inhibition of recurrence of fibrous epulides. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) presents impediment to wound healing. While ultraviolet B (UVB) exposure showed therapeutic potential in various skin conditions, its capacity to mediate diabetic wound healing remains unclear. To investigate the efficacy of UVB on wound healing and its underlying basis. Materials and Methods: Male C57BL/6 mice were subjected to the high‐fat diet followed by streptozotocin administration to establish the diabetic model. Upon confirmation of diabetes, full‐thickness wounds were inflicted and the treatment group received UVB radiation at 50 mJ/cm2 for 5 min every alternate day for 2 weeks. Wound healing rate was then assessed, accompanied by evaluations of blood glucose, lipid profiles, CD31 expression, and concentrations of ghrelin and leptin. Concurrently, in vitro studies were executed to evaluate the protective role of ghrelin on human umbilical vein endothelial cells (HUVEC) under high glucose (HG) conditions. Results: Post UVB exposure, there was a marked acceleration in wound healing in DM mice without alterations in hyperglycemia and lipid profiles. Compared to non‐UVB‐exposed mice, the UVB group showed enhanced angiogenesis manifested by a surge in CD31 expression. This trend appeared to be in harmony with the elevated ghrelin levels. In vitro experiments indicated that ghrelin significantly enhanced the migratory pace and angiogenic properties of HUVEC under HG‐induced stress, potentially mediated by an upregulation in vascular endothelial growth factor expression. Conclusion: UVB exposure bolstered wound healing in diabetic mice, plausibly mediated through augmented angiogenesis induced by ghrelin secretion. Such findings underscore the vast potential of UVB‐induced ghrelin in therapeutic strategies targeting diabetic wound healing. [ABSTRACT FROM AUTHOR]

Abstract Background Drug-resistant tuberculosis (DR-TB), obesity, and malnutrition are growing public health problems in the world. However, little has discussed the impact of different BMI status on the emergence of TB drug resistance. We aimed to explore the drug-resistant profiles of DR-TB and its clinical predictors among underweight, overweight or obesity population. Methods 8957 newly diagnosed TB cases with drug susceptibility results and BMI data in Shandong China, from 2004 to 2019 were enrolled. Multivariable and univariable logistic regression models were applied to investigate the impact of BMI on different drug-resistance. Clinical predicators and drug-resistant profiles of DR-TB among obesity, underweight, normal TB group were also described. Results Among 8957 TB cases, 6417 (71.64%) were normal weight, 2121 (23.68%) were underweight, 373 (4.16%) were overweight, and 46 (0.51%) were obese. The proportion of drug resistance and co-morbidity among normal weight, underweight, overweight, obese TB groups were 18.86%/18.25%/20.38%/23.91% (DR-TB), 11.19%/11.74%/9.65%/17.39% (mono-resistant tuberculosis, MR-TB), 3.41%/3.06%/5.36%/0.00% (multidrug resistant tuberculosis, MDR-TB), 4.21%/3.39%/5.36%/6.52% (polydrug resistant tuberculosis, PDR-TB), 10.57%/8.44%/19.57%/23.91% (co-morbidity), respectively. Compared with normal weight group, underweight were associated with lower risk of streptomycin-related resistance (OR 0.844, 95% CI 0.726–0.982), but contributed to a higher risk of MR-TB (isoniazid) (odds ratio (OR) 1.347, 95% CI 1.049–1.730; adjusted OR (aOR) 1.31, 95% CI 1.017–1.686), P