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Abstract Microbes evolved resistance determinates for coping with arsenic toxicity are commonly regulated by a variety of transcriptional repressors (ArsRs). Ensifer adhaerens strain ST2 was previously shown tolerance to environmental organoarsenical methylarsenite (MAs(III)), which has been proposed to be a primordial antibiotic. In E. adhaerens strain ST2 chromosomal ars operon, two MAs(III) resistance genes, arsZ, encoding MAs(III) oxidase, and arsK, encoding MAs(III) efflux transporter, are controlled by a novel ArsR transcriptional repressor, EaArsR. It has two conserved cysteine pairs, Cys91-92 and Cys108-109. Electrophoretic mobility shift assays (EMSAs) demonstrate that EaArsR binds to two inverted-repeat sequences within the ars promoter between arsR and arsZ to repress ars operon transcription and that DNA binding is relieved upon binding of As(III) and MAs(III). Mutation of either Cys91 or Cys92 to serine (or both) abolished these mutants binding to the ars promoter. In contrast, both C108S and C109S mutants kept responsiveness to As(III) and MAs(III). These results suggest that cysteine pair Cys91-Cys92 and either Cys108 or Cys109 contribute to form arsenic binding site. Homology modeling of EaArsR indicates the binding site consisted of Cys91-Cys92 pair from one monomer and Cys108-Cys109 pair from the other monomer, which displays the diverse evolution of arsenic binding site in the ArsR metalloregulators. A novel ArsR from Ensifer adhaerens strain ST2 regulates methylarsenite resistance genes expression.

Background Healthcare in China has significantly improved, meanwhile many  socio-economic risk factors and health conditions factors affect accessibility and utilization of health services in rural areas. Inequity of health service in China needs to  be estimated and reduced. Andersen behavioral model is useful to assess the association of health service utilization with predisposing, enabling, and need factors. Methods A survey was conducted among 4634 residents of 897 households in 2012. Logistic regression analysis was performed to explore the association of predisposing (age, gender, marital status, ethnicity and family size), enabling (education level, travel time to the nearest health facility, medical expense per capita, and health insurance coverage), and need factors (chronic disease) with the utilization of health services (i.e. physician visit and hospitalization). Results We observed a significant association between need factor (chronic diseases) and health service unitization, after adjusting for all predisposing and enabling factors (physician visits: odds ratio (OR) = 5.87, 95 % confidence interval (CI) = 4.71–7.32; hospitalization: OR = 4.04, 95 % CI = 2.90–5.61, respectively). In addition, age, gender, marital status, family size and education level were significant predictors of health service utilization. The travel time to the nearest health facility was associated with the utilization of physician visits, and expenditure on healthcare was a hindering factor of hospitalization. Conclusions The predisposing and enabling factors had a minor impact on health service utilization, while the need factor was a dominant predictor of health service utilization among rural residents in China.

In this study, laponite was tested as a mud-making material for drilling fluids. Laponite is a synthetic smectite clay with a structure and composition closely resembling the natural clay mineral hectorite. Commercially available laponite was characterized by X-ray diffractometry, scanning electron microscopy and infrared spectrometry. Its dispersibility, salt resistance and high-temperature resistance were evaluated. The results showed that laponite possessed superior cation exchange capacity (140.4 mmol/100 g) with interlayer cations of Na + and Li + . Laponite could easily be dispersed in water to yield increased viscosity with no influence from hydration time or temperature. On the other hand, laponite dispersions displayed an excellent heat resistance, with invariant apparent viscosity at high temperatures. For instance, the apparent viscosity of the 2 wt% laponite dispersion underwent changes between 22 and 24 mPa s after hot rolling at 180–240 °C for 16 h. Compared to existing mud-making materials, laponite exhibited better mud-making properties. Furthermore, laponite revealed good compatibility with other additives, and the water-based drilling fluids prepared with laponite as mud-making material showed an excellent stability at elevated temperatures and superior performance–cost ratios. Overall, these findings indicated that laponite had an excellent dispersibility at high temperatures and hence would have promising applications as high-temperature mud-making material for preparing water-based drilling fluids designed for ultra-high-temperature environments.

Economically underdeveloped areas in western China are hotspots of tuberculosis, especially among students. However, the related spatial and temporal patterns and influencing factors are still unclear and there are few studies to analyze the causes of pulmonary tuberculosis in students from the perspective of space. We collected data regarding the reported incidence of pulmonary tuberculosis (PTB) among students at township level in Nanning, from 2012 to 2018. The reported incidence of pulmonary tuberculosis among students in Nanning was analyzed using spatial autocorrelation and spatial scan statistical analysis to depict hotspots of PTB incidence and spatial and temporal clustering. Spatial panel data of the reported incidence rates and influencing factors at district and county levels in Nanning were collected from 2015 to 2018. Then, we analyzed the spatial effects of incidence and influencing factors using the spatial Durbin model to explore the mechanism of each influencing factor in areas with high disease prevalence under spatial effects. From 2012 to 2018, 1609 cases of PTB were reported among students in Nanning, with an average annual reported incidence rate of 14.84/100,000. Through the Joinpoint regression model, We observed a steady trend in the percentage of cases reported each year (P>0.05). There was spatial autocorrelation between the annual reported incidence and the seven-years average reported incidence from 2012 to 2018. The high-incidence area was distributed in the junction of six urban areas and spread to the periphery, with the junction at the center. The population of college students, per capita financial expenditure on health, per capita gross domestic product, and the number of health technicians per 1,000 population were all influencing factors in the reported incidence of PTB among students. We identified spatial clustering of the reported incidence of PTB among students in Nanning, mainly located in the urban center and its surrounding areas. The clustering gradually decreased from the urban center to the surrounding areas. Spatial effects influenced the reported incidence of PTB. The population density of college students, per capita health financial expenditure, gross domestic product (GDP) per capita, and the number of health technicians per 1,000 were all influencing factors in the reported incidence of PTB among students.

Chitin deacetylase (CDA) is a chitin degradation enzyme that strictly catalyzes the deacetylation of chitin to form chitosan, which plays an important role in regulating growth and development, as well as the immune response. In this study, a chitin deacetylase 3 gene (CDA3) was identified with a complete open reading frame (ORF) of 1362 bp from the genome database of Diaphorina citri, encoding a protein of 453 amino acids. Spatiotemporal expression analysis suggested that D. citri CDA3 (DcCDA3) had the highest expression level in the integument and third-instar nymph stage. Furthermore, DcCDA3 expression level can be induced by 20-hydroxyecdysone (20E). Injection of Escherichia coli and Staphylococcus aureus induced the upregulation of DcCDA3 in the midgut, while DcCDA3 was downregulated in the fat body. After silencing DcCDA3 by RNA interference, there was no influence on the D. citri phenotype. In addition, bactericidal tests showed that recombinant DcCDA3 inhibited gram-positive bacteria, including S. aureus and Bacillus subtilis (B. subtilis). In conclusion, our results suggest that DcCDA3 might play an important role in the immune response of D. citri.

Chitin synthase is a critical enzyme that catalyzes N-acetylglucosamine to form chitin, which plays an important role in the growth and development of insects. In this study, we identified a chitin synthase gene (CHS) with a complete open reading frame (ORF) of 3180 bp from the genome database of Diaphorina citri, encoding a protein of 1059 amino acid residues with the appropriate signature motifs (EDR and QRRRW). Reverse transcription-quantitative PCR (RT-qPCR) analysis suggested that D. citri CHS (DcCHS) was expressed throughout all developmental stages and all tissues. DcCHS had the highest expression level in the integument and fifth-instar nymph stage. Furthermore, the effects of diflubenzuron (DFB) on D. citri mortality and DcCHS expression level were investigated using fifth-instar nymph through leaf dip bioassay, and the results revealed that the nymph exposed to DFB had the highest mortality compared with control group (Triton-100). Silencing of DcCHS by RNA interference resulted in malformed phenotypes and increased mortality with decreased molting rate. In addition, transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH) also revealed corresponding ultrastructural defects. Our results suggest that DcCHS might play an important role in the development of D. citri and can be used as a potential target for psyllid control.

Chitin is one the main components of the insect cuticle, and chitin synthase (CHS) is an important enzyme required for chitin formation. CHS has been characterized in various insect species, but the structure and biochemical properties in Spodoptera litura have not been determined. In this study, we identified two CHS genes, SlCHS1 and SlCHS2, which encode proteins with 1565 and 1520 amino acid residues, respectively. Transcriptional analysis suggested that SlCHS1 has a high expression level in the integument whereas SlCHS2 showed the highest expression level in the midgut. During S. litura growth and development, SlCHS1 and SlCHS2 were both predominantly expressed in the fourth-instar larval stage. In addition, the expression of SlCHS1 and SlCHS2 could be induced by 20-hydroxyecdysone (20E). Silencing of SlCHS1 by RNA interference significantly inhibited the pupation and molting of S. litura larvae (RNAi), while knockdown of SlCHS2 had no significant effects on the S. litura phenotype. These results may provide a new molecular target for control of S. litura.

Background： A large proportion of the patients with papillary thyroid microcarcinoma are young women. Therefore, minimally invasive endoscopic thyroidectomy with central neck dissection （CND） emerged and showed well-accepted results with improved cosmetic outcome, accelerated healing, and comforting the patients. This study aimed to evaluate the safety and effectiveness of robotic total thyroidectomy with CND via bilateral axillo-breast approach （BABA）, compared with conventional open procedure in papillary thyroid microcarcinoma. Methods： One-hundred patients with papillary thyroid microcarcinoma from March 2014 to January 2015 in Jinan Military General Hospital of People＇s Liberation Army （PLA） were randomly assigned to robotic group or conventional open approach group （17 = 50 in each group）. The total operative time, estimated intraoperative blood loss, numbers of lymph node removed, visual analog scale （VAS）, postoperative hospital stay time, complications, and numerical scoring system （NSS, used to assess cosmetic effect） were analyzed. Results： The robotic total thyroidectomy with CND via BABA was successfully performed in robotic group. There were no conversion from the robotic surgeries to open or endoscopic surgery. The subclinical central lymph node metastasis rate was 35%. The mean operative time of the robotic group was longer than that of the conventional open approach group （118.8± 16.5 min vs. 90.7± 10.3 min, P 〈 0.05）. The study showed significant differences between the two groups in terms of the VASs （2.1 ± 1.0 vs. 3.8 ±~ 1.2, P 〈 0.05） and NSS （8.9 ± 0.8 vs. 4.8 ± 1.7, P 〈 0.05）. The differences between the two groups in the estimated intraoperative blood loss, postoperative hospital stay time, numbers of lymph node removed, postoperative thyroglobulin levels, and complications were not statistically significant （all P 〉 0.05）. Neither iatrogenic implantation nor metastasis occurred in punctured porous channel or chest wall in both groups. Postoperative cosmetic results were very satisfactory in the robotic group. Conclusions： Robotic total thyroidectomy with CND via BABA is safe and effective for Chinese patients with papillary thyroid microcarcinoma who worry about the neck scars.

Background Deterioration of sleep quality has been reported to contribute to the incidence of diabetes and may be responsible for glycemic status in diabetes. The present study explored the relationship between sleep quality and glycemic variability in patients with type 2 diabetes (T2D). Methods We recruited 111 patients with T2D for this cross-sectional study. Each patient underwent flash glucose monitoring for 14 days to obtain glycemic variability parameters, such as standard deviation of glucose (SD), coefficient of variation of glucose (CV), mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), and time in glucose range of 3.9–10 mmol/L (TIR 3.9–10 ). After 14 days of flash glucose monitoring, each patient received a questionnaire on the Pittsburgh Sleep Quality Index (PSQI) to evaluate subjective sleep quality. HbA1c was also collected to assess average glucose. Results HbA1c was comparable among the subgroups of PSQI score tertiles. Across ascending tertiles of PSQI scores, SD, CV and MAGE were increased, while TIR 3.9–10 was decreased ( p for trend  <  0.05), but not MODD ( p for trend  =  0.090). Moreover, PSQI scores were positively correlated with SD, CV, MODD and MAGE ( r  =  0.322, 0.361, 0.308 and 0.354, respectively, p   <  0.001) and were inversely correlated with TIR 3.9–10 ( r   =  − 0.386, p   <  0.001). After adjusting for other relevant data by multivariate linear regression analyses, PSQI scores were independently responsible for SD ( β   =  0.251, t   =  2.112, p   =  0.041), CV ( β   =  0.286, t   =  2.207, p   =  0.033), MAGE ( β   =  0.323, t   =  2.489, p   =  0.018), and TIR 3.9–10 ( β   =  − 0.401, t   =  − 3.930, p   <  0.001) but not for MODD ( β   =  0.188, t  =  1.374, p   =  0.177). Conclusions Increased glycemic variability assessed by flash glucose monitoring was closely associated with poor subjective sleep quality evaluated by the PSQI in patients with T2D.

Background Increased serum carcinoembryonic antigen (CEA) levels are reported to be associated with various metabolic and inflammatory diseases. This study assessed whether high-normal serum CEA is related to diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes (T2D). Methods All subjects received DPN assessment based on neuropathic symptoms, neuropathic signs, and nerve conduction studies to calculate composite Z scores of nerve latency, amplitude and conduction velocity (NCV). DPN was confirmed by both at least a presentation of neuropathic symptoms/signs and an abnormal nerve conduction index. Serum CEA levels and other clinical indices were also synchronously detected. Multivariable linear regression analyses were used to determine the independent effects of serum CEA levels on nerve conduction indices, multivariable logistic regression analyses were used to determine the independent impact of CEA levels on the risk of DPN, and receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic capability of CEA levels to discriminate DPN. Results We ultimately recruited 402 eligible subjects with normal ranges of serum CEA for this study, and 25.4% (n = 102) were determined to have DPN. After adjusting for other clinical covariates, serum CEA levels were independently associated with the composite Z score for latency ( β  = 0.132, t  = 2.330, p  = 0.021), amplitude ( β  = − 0.164, t  = − 2.838, p  = 0.005) and NCV ( β  = − 0.210, t  = − 3.662, p  < 0.001). Moreover, the prevalence of DPN in the first, second, third and fourth quartiles of CEA level was 12.9%, 19.0%, 29.4% and 40.4%, respectively ( p for trend  < 0.001); the corresponding adjusted odds ratios and 95% CIs for DPN in CEA quartiles were 1, 1.47 (0.45–4.82), 1.72 (0.54–5.53) and 4.58 (1.39–15.06), respectively. Furthermore, the optimal cut-off value of high-normal serum CEA to discriminate DPN was ≥ 2.66 ng/mL, with a Youden index of 0.28, sensitivity of 66.67% and specificity of 61.00%. Conclusions Increased serum CEA levels within the normal range are closely linked to dysfunction of peripheral nerve conduction and the risk of DPN, and high-normal serum CEA levels are a potential risk factor for DPN in T2D.