The characterization of conserved binding motifs and potential target genes for M. tuberculosis MtrAB reveals a link between the two-component system and the drug resistance of M. smegmatis

<p>Abstract</p> <p>Background</p> <p>The two-component systems of <it>Mycobacterium tuberculosis </it>are apparently required for its growth and resistance in hostile host environments. In such environments, MtrAB has been reported to regulate the expression of the <it>M. tuberculosis </it>replication initiator gene, <it>dnaA</it>. However, the <it>dnaA </it>promoter binding sites and many potential target genes for MtrA have yet to be precisely characterized.</p> <p>Results</p> <p>In this study, a 7 bp sequence motif in the <it>dnaA </it>promoter region was identified for MtrA binding using DNaseI footprinting assays and surface plasmon resonance (SPR) analysis. Approximately 420 target genes potentially regulated by MtrA, including the isoniazid inducible gene <it>iniB</it>, were further characterized from <it>M. tuberculosis </it>and <it>M. smegmatis </it>genomes. When assayed using quantitative real-time PCR (qRT-PCR), many of the target genes demonstrated significant expression changes when the antisense mRNA of the <it>mtrA </it>gene was expressed in <it>M. smegmatis</it>. The recombinant mycobacteria grew in length and were more sensitive to two anti-tuberculosis drugs, isoniazid and streptomycin.</p> <p>Conclusions</p> <p>These findings yield critical information about the regulatory mechanisms of the MtrAB two-component system and its role in the drug resistance of <it>M. smegmatis</it>.</p

Accelerated Degradation of Coating-mortar Interface under UV Radiation in Presence of Water

The application of organic coatings is one of the most effective and economic methods to protect concrete structures from deterioration. However, organic coatings are prone to degradation under aggressive environmental actions, so the protective function may loss. While ultraviolet (UV) aging is often blamed for the degradation of organic coatings, water may play a more important role on the interfacial adhesion between the coatings and the substrate. To uncover the effect of water on the degradation performance of coating-substrate system, mortar samples coated with water-borne epoxy resin (WER) were exposed to three assigned environments, i.e., UV radiation, UV/water immersion, and UV/dry-wet cycle, up to 60 days. The surface appearance, chemical structure, wettability, and surface micro-morphology of the aged WER coatings were characterized via image process analysis, attenuated total reflectance flourier transform infrared spectroscopy (ATR&ndash;FTIR), static water contact angle, and scanning electronic microscopy (SEM). Results show that the UV/water immersion resulted in severest blistering on the WER-mortar interface, while the UV/wet-dry cycle caused the formation of micro-pinholes on the WER surface. In contrast, the UV radiation did not induce such severe aging. The data implied that water can accelerate the aging of WER-mortar system

DYNAMICS ANALYSIS ON REFLEXED BOW

Reflexed bow and composite bow competition are two main categories in shooting game. Nowadays, only reflex bow competition is in Olympics game. Therefore, we choose the reflex bow as our test object. According to the literature we collected. Up to now, There is no experiment carried out on dynamics analysis on reflex bow .so we make some efforts on this field. We attempted to have a further understand on it and hope to make some useful suggestion on archery athletics, help them ,to understand bow's feature and improve their results

Knee Osteoarthritis, Potential Mediators, and Risk of All-Cause Mortality: Data From the Osteoarthritis Initiative.

ObjectiveTo assess the relation of symptomatic knee osteoarthritis (OA), knee pain, and radiographic knee OA to All-cause mortality and to identify mediators in the causal pathway.MethodsParticipants from the Osteoarthritis Initiative were divided into 4 groups: 1) symptomatic knee OA (i.e., both radiographic knee OA [Kellgren/Lawrence grade ≥2] and knee pain); 2) knee pain only; 3) radiographic knee OA only; and 4) neither radiographic knee OA nor knee pain. We examined the relation of knee OA status to All-cause mortality using a multivariable Cox proportional hazards model and assessed the extent to which the association was mediated by disability, physical component summary (PCS) and mental component summary (MCS) scores for quality of life (QoL), and use of oral pain-relief medications (i.e., nonsteroidal antiinflammatory drugs and opioids).ResultsAmong 4,796 participants, 282 died over the 96-month follow-up period. Compared with those with neither radiographic knee OA nor knee pain, multivariable-adjusted hazard ratios (HRs) of mortality were 2.2 (95% confidence interval [95% CI] 1.6-3.1) for symptomatic knee OA, 0.9 (95% CI 0.6-1.4) for knee pain only, and 2.0 (95% CI 1.4-2.9) for radiographic knee OA only, respectively. Indirect effects (HRs) of symptomatic knee OA on mortality via disability and PCS of QoL were 1.1 (95% CI 1.0-1.4) and 1.2 (95% CI 1.0-1.4), respectively. No apparent mediation effect was observed through either MCS of QoL or oral pain-relief medications use.ConclusionParticipants with either symptomatic or radiographic knee OA were at an increased risk of All-cause mortality. Increased risk of mortality from symptomatic knee OA was partially mediated through its effect on disability and PCS of QoL

The Impact of General Self-Efficacy on Psychological Resilience During the COVID-19 Pandemic: The Mediating Role of Posttraumatic Growth and the Moderating Role of Deliberate Rumination

Purpose: This study used a moderated mediation model to explore the relationship between general self-efficacy (GSE) and psychological resilience (PR) and the associated mechanisms, the mediating role of posttraumatic growth (PTG), and the moderating role of deliberate rumination (DR) during the coronavirus disease 2019 (COVID-19) pandemic. Knowledge of the relationship between these four variables examined further understanding of the PR improvement mechanism of college students and even the general public.Methods: The college students who participated in this study came from an independent college in Guangdong Province, China. A total of 918 college students completed the survey, and the final data sample size was 881. SPSS 23.0 and PROCESS (version 3.3) were used to conduct Pearson's correlation analysis and hierarchical regression linear analysis on the data.Results: (1) The correlation analysis showed that GSE and PR were positively correlated and that PTG was positively correlated with GSE and PR. DR was positively correlated with GSE, PTG, and PR. (2) The results of mediation analysis showed that GSE had a direct predictive effect on DR, and PTG partially mediated the relationship between the two. (3) The results of moderating effect analysis showed that DR hindered the effect of GSE on PTG but enhanced the positive impact of PTG on PR.Conclusions: General self-efficacy can improve PR under the mediating influence of PTG. DR played a positive moderating role in the relationship between GSE and PTG, and played a negative moderating role in the relationship between PTG and PR. These results advance the understanding of the mechanism between GSE and PR

Association of Tramadol Use With Risk of Hip Fracture.

Several professional organizations have recommended tramadol as one of the first-line or second-line therapies for patients with chronic noncancer pain and its prescription has been increasing rapidly worldwide; however, the safety profile of tramadol, such as risk of fracture, remains unclear. This study aimed to examine the association of tramadol with risk of hip fracture. Among individuals age 50 years or older without a history of hip fracture, cancer, or opioid use disorder in The Health Improvement Network (THIN) database in the United Kingdom general practice (2000-2017), five sequential propensity score-matched cohort studies were assembled, ie, participants who initiated tramadol or those who initiated one of the following medications: codeine (n = 146,956) (another commonly used weak opioid), naproxen (n = 115,109) or ibuprofen (n = 107,438) (commonly used nonselective nonsteroidal anti-inflammatory drugs [NSAIDs]), celecoxib (n = 43,130), or etoricoxib (n = 27,689) (cyclooxygenase-2 inhibitors). The outcome was incident hip fracture over 1 year. After propensity-score matching, the included participants had a mean age of 65.7 years and 56.9% were women. During the 1-year follow-up, 518 hip fracture (3.7/1000 person-years) occurred in the tramadol cohort and 401 (2.9/1000 person-years) occurred in the codeine cohort. Compared with codeine, hazard ratio (HR) of hip fracture for tramadol was 1.28 (95% confidence interval [CI] 1.13 to 1.46). Risk of hip fracture was also higher in the tramadol cohort than in the naproxen (2.9/1000 person-years for tramadol, 1.7/1000 person-years for naproxen; HR = 1.69, 95% CI 1.41 to 2.03), ibuprofen (3.4/1000 person-years for tramadol, 2.0/1000 person-years for ibuprofen; HR = 1.65, 95% CI 1.39 to 1.96), celecoxib (3.4/1000 person-years for tramadol, 1.8/1000 person-years for celecoxib; HR = 1.85, 95% CI 1.40 to 2.44), or etoricoxib (2.9/1000 person-years for tramadol, 1.5/1000 person-years for etoricoxib; HR = 1.96, 95% CI 1.34 to 2.87) cohort. In this population-based cohort study, the initiation of tramadol was associated with a higher risk of hip fracture than initiation of codeine and commonly used NSAIDs, suggesting a need to revisit several guidelines on tramadol use in clinical practice. © 2020 American Society for Bone and Mineral Research

Crosstalk between microbial biofilms in the gastrointestinal tract and chronic mucosa diseases

The gastrointestinal (GI) tract is the largest reservoir of microbiota in the human body; however, it is still challenging to estimate the distribution and life patterns of microbes. Biofilm, as the predominant form in the microbial ecosystem, serves ideally to connect intestinal flora, molecules, and host mucosa cells. It gives bacteria the capacity to inhabit ecological niches, communicate with host cells, and withstand environmental stresses. This study intends to evaluate the connection between GI tract biofilms and chronic mucosa diseases such as chronic gastritis, inflammatory bowel disease, and colorectal cancer. In each disease, we summarize the representative biofilm makers including Helicobacter pylori, adherent-invasive Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. We address biofilm’s role in causing inflammation and the pro-carcinogenic stage in addition to discussing the typical resistance, persistence, and recurrence mechanisms seen in vitro. Biofilms may serve as a new biomarker for endoscopic and pathologic detection of gastrointestinal disease and suppression, which may be a useful addition to the present therapy strategy