In the manufacturing process of aerospace large ring parts, a large number of exterior materials are removed, which makes the ring parts become a thin-walled structure with low stiffness. In the ...actual production process of the aerospace industry, the processing deformation caused by a series of internal and external factors is ubiquitous. The studies show that the main factor causing the machining deformation is the initial residual stress (RS) inside the blank ring. The ring rolling process is accompanied by local severe plastic deformation, resulting in large and uneven RS. The homogenization and reduction of initial RS are of great significance to reduce the adverse effect of machining deformation. The research object in this study is a sizeable GH4169 alloy aerospace rolling ring. First, a long-term natural ageing treatment was designed for homogenizing residual stresses in sizeable GH4169 alloy ring. Second, a finite element model was established to simulate the rolling process and the thermal ageing process. The corresponding rolling and thermal ageing experiments were carried out to verify the simulation results. The purpose of this process is to explore and verify the effect of natural ageing and artificial ageing on homogenizing and reducing the RS in the rolling ring. The results show that the homogenization of RS distribution was enhanced significantly by natural ageing treatment, while the RS magnitudes descended by 15~35%. Combined with the subsequent thermal stress relief, the RS is significantly reduced or even eliminated. This study is of great significance to the homogenization and reduction of RS in large GH4169 alloy ring.
In the actual production process of the aerospace industry, machining deformation is common due to internal and external factors. Studies indicate that the release and redistribution of initial ...residual stresses within the component is the main factor distorting machining and service. Therefore, the reduction and homogenization of initial residual stresses are necessary to avoid machining distortion problems and to improve the overall quality of ring parts. The process of ring rolling and cooling tends to produce large and unevenly distributed residual stresses. The main research object of this paper is the TC4 titanium alloy profiled aerospace rolling ring. Firstly, a mechanical model of the radial rolling process was developed. Residual stress evaluation indexes matching the shape characteristics of profiled rings were designed. According to the continuous and penetration conditions, reasonable rolling process parameters and their range are determined. Secondly, a finite element model was established to simulate the rolling and cooling process. The simulation results were verified by corresponding rolling experiments based on the hole-drilling method. The experimental results were in high consistency with the simulation results. Finally, the response surface methodology and the finite element method were combined to jointly optimize the main process parameters of the rolling process. A second-order response prediction model was established for the ring parts with the numerical value and homogenization of the residual stresses as the integrated optimization objective. Based on the simulation results and the response model, the influence of each design variable on the residual stress of the ring is systematically analyzed and the optimal combination of process parameters is obtained and verified.
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•nZVI addition can enhance both AD performance and TC degradation.•Anaerobic digestion has high removal rate of TC in systems with low TC concentration.•Low TC concentration addition ...has positive effect on anaerobic methane production.•Addition of nZVI can alter the microbial communities’ structure during AD process.•The increase of Syntrophobacterale and Methanosarcinales resulted in high CH4 production.
Supplementing nano zero valent iron (nZVI) is an attractive technology for wastewater treatment due to its advantages in accelerating the hydrolysis, fermentation and anaerobic digestion (AD) process. In this present study, nZVI was added to investigate its effects on enhancing tetracycline (TC) wastewater anaerobic treatment and the changes of microbial community, especially for underestimated syntrophic-methanogenic associations. The TC concentrations were 1, 10, 30, 50, 80, 100 and 150 mg/L with 0.38 g nZVI (with iron g/g VS of 0.50) complemented into reactors. Results revealed that nZVI could enhance AD process in both control and TC dosed systems, and the promoting effect on methanogenesis was more significant in systems of high concentration TC, with 100 and 150 mg/L. In addition, cumulative CH4 production for all TC added systems without nZVI were higher than the control indicating TC had positive effect instead of expected negative effect on AD process, high TC concentration of 100 and 150 mg/L only affecting the increase factor rather than causing inhibitory effect. After digestion, TC was largely removed in with/without nZVI systems. And also, nZVI evidently altered the bacterial and methanogenic community structure, with an increase abundance of syntrophic-methanogenic associations (Syntrophobacterales and Methanosarcinales) and resulting in the enhancement of methane generation. This research provides an efficient method for TC wastewater anaerobic treatment.
Abstract
BACKGROUND
The rupture risk assessment of unruptured intracranial aneurysms (IAs) is still challenging. Aneurysm wall enhancement (AWE) on vessel wall magnetic resonance imaging (VW-MRI) is ...suggested as a potential marker for wall inflammation, but its relationship with rupture risk of unruptured IAs has not been well described.
OBJECTIVE
To investigate the correlation between AWE and conventional rupture risk factor of unruptured IAs.
METHODS
Clinical data and VW-MRI images were retrospectively reviewed in patients with unruptured IAs from January 2015 to December 2016 in our center. One hundred ten patients harboring 140 unruptured IAs were included. The presence of AWE was determined by comparing the postcontrast VW-MRI images with the precontrast ones. The rupture risk based on the PHASES score was calculated for each case. Univariate and multivariate analysis were performed to investigate the association of AWE with rupture risk and other conventional risk factors.
RESULTS
AWE was present in 82 (58.6%) lesions. Unruptured IAs with AWE had significantly larger size (P < .001), more irregular shape (P = .003), and different distribution of locations (P = .023) comparing with aneurysms without AWE. The rupture risk score of AWE group was significantly higher than non-AWE group (P < .001). Aneurysm size (odds ratio = 1.536; 95% confidential interval 1.312-1.798; P < .001) and location (odds ratio = 1.592; 95% confidential interval 1.237-2.049; P < .001) were independently related with AWE in multivariate analysis.
CONCLUSION
The presence of AWE on VW-MRI was highly associated with conventional rupture-related characteristics, including aneurysmal size and location, and was detected more frequently in unruptured IAs with high rupture risk based on the PHASES score.
Tigecycline is one of the last-resort antibiotics to treat complicated infections caused by both multidrug-resistant Gram-negative and Gram-positive bacteria
. Tigecycline resistance has sporadically ...occurred in recent years, primarily due to chromosome-encoding mechanisms, such as overexpression of efflux pumps and ribosome protection
. Here, we report the emergence of the plasmid-mediated mobile tigecycline resistance mechanism Tet(X4) in Escherichia coli isolates from China, which is capable of degrading all tetracyclines, including tigecycline and the US FDA newly approved eravacycline. The tet(X4)-harbouring IncQ1 plasmid is highly transferable, and can be successfully mobilized and stabilized in recipient clinical and laboratory strains of Enterobacteriaceae bacteria. It is noteworthy that tet(X4)-positive E. coli strains, including isolates co-harbouring mcr-1, have been widely detected in pigs, chickens, soil and dust samples in China. In vivo murine models demonstrated that the presence of Tet(X4) led to tigecycline treatment failure. Consequently, the emergence of plasmid-mediated Tet(X4) challenges the clinical efficacy of the entire family of tetracycline antibiotics. Importantly, our study raises concern that the plasmid-mediated tigecycline resistance may further spread into various ecological niches and into clinical high-risk pathogens. Collective efforts are in urgent need to preserve the potency of these essential antibiotics.
To obtain nitrogen-doped carbon dots (N-CDs) for sensing Fe
3+
under acidic conditions, robust and highly fluorescent N-CDs were prepared by one-pot hydrothermal treatment of dopamine and ...ethylenediamine. The N-CDs have a relatively uniform size of approximately 4.9 nm and good water dispersibility. The N-CDs exhibit strong visible fluorescence (
ca.
497 nm) and high stability at low pH (
i.e.
2-3). The FTIR spectra and the XPS analyses indicated that primary amines and distinctive catechol groups exist on the surface of the N-CDs. The FTIR spectra further prove that the catechol groups on their surfaces can be oxidized to the quinone species by Fe
3+
, contributing to fluorescence response to Fe
3+
. Thus, the N-CDs as fluorescence probes allowed the detection of Fe
3+
under acidic conditions, which has been verified in this work.
The N-CDs with primary amines and catechol groups on the surface serve as a fluorescence probe for sensing Fe
3+
at low pH.
Few studies have used nationally representative data to focus specifically on gender differences in weight-related outcomes. This article examines gender differences in weight-related outcomes across ...the body mass index (BMI) spectrum in overweight and obese adults. Data from the National Health and Nutrition Examination Survey 2009–2010 was analyzed. Weight-related outcomes were accurate weight perception, weight dissatisfaction, attempted weight loss, successful weight loss, and weight loss strategies. Compared with women, overweight and obese men were less likely to have accurate weight perception (odds ratio OR = 0.36; 95% confidence interval CI = 0.30–0.44), weight dissatisfaction (OR = 0.39; 95% CI = 0.32–0.47), and attempted weight loss (OR = 0.55; 95% CI = 0.48–0.63). The modifying effect of gender on these associations decreased as BMI increased. By BMI 35, the mean probability of women and men to have accurate weight perception and weight dissatisfaction was 90%; attempted weight loss was 60% (women) and 50% (men). At lower BMIs, men had up to 40% less probability than women for these weight loss outcomes. Men who attempted weight loss were more likely than women to lose and maintain ≥10 lb over 1 year (OR = 1.41; 95% CI = 1.20–1.65) and increase exercise and eat less fat as weight loss strategies; women were more likely to join weight loss programs, take prescription diet pills, and follow special diets. A need exists for male-specific interventions to improve overweight and obese men’s likelihood for accurate weight perception, attempted weight loss, and ultimately, successful weight loss.
Abstract Background There is limited information available concerning the delta neutrophil to lymphocyte ratio (ΔNLR) in hepatocellular carcinoma (HCC). The present study was designed to evaluate the ...predictive value of dynamic change of NLR in patients who undergo curative resection for small HCC. Methods A retrospective cohort study was performed to analyze 189 patients with small HCC who underwent curative resection between February 2007 and March 2012. Patient data were retrieved from our prospectively maintained database. Patients were divided into two groups: group A (NLR increased, n = 80) and group B (NLR decreased, n = 109). Demographic and clinical data, overall survival (OS), and recurrence-free survival (RFS) were statistically compared and a multivariate analysis was used to identify prognostic factors. Results The 1, 3, and 5-y OS in group A was 92.7, 70.0, and 53.0%, respectively, and 96.2, 87.5, and 75.9%, respectively, for group B ( P = 0.003); The corresponding 1, 3, and 5-y RFS was 58.7, 37.9, 21.8, and 81.2%, 58.5% and 53.8% for groups A and B, respectively ( P <0.001). Multivariate analysis suggested that ΔNLR was an independent prognostic factor for both OS ( P = 0.004, Hazard Ratio (HR) = 2.637, 95% confidence interval (CI) 1.356–5.128) and RFS ( P <0.001, HR = 2.372, 95% CI 1.563–3.601). Conclusions Increased NLR, but not high preoperative NLR or postoperative NLR, helps to predict worse OS and RFS in patients with small HCC who underwent curative resection.
HPV16 and 18 are positively correlated with cervical carcinogenesis. However, HPV prevalence tends to vary according to region, nationality, and environment. The most prevalent high-risk (HR) HPV ...genotypes are HPV16, 52, 58, 56, 18, 33, and 45), while the low-risk (LR) genotypes are HPV6 and 11 in the Chinese population. Importantly, undetectable low-copy HPV DNA could be an important indicator of integration into the human genome and may be a precursor to cancer progression. The HPV viral load changes dramatically, either increasing or decreasing rapidly during carcinogenesis, and traditional quantitative real-time PCR (qPCR) cannot accurately capture this subtle change. Therefore, in this study, a reliable droplet digital PCR (ddPCR) method was developed to simultaneously detect and quantify HPV genotypes. The ddPCR quantitative results showed high accuracy, sensitivity, and specificity compared to qPCR results employing the same clinical specimens and supplemented the ddPCR assay for HPV52/56/58/6 genotypes according to the infection specificity of the Chinese population. In summary, this procedure is valuable for quantifying HPV DNA, especially under conditions of low template copy number in cervical intraepithelial neoplasia (CIN) and/or cervical cancer. Additionally, this method can dynamically observe the prognosis and outcome of HPV infection and thus be used as an effective means for real-time monitoring of tumor load.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose of Review
To synthesize evidence from randomized controlled trials on the effects of integrated behavioral interventions for comorbid obesity and depression in adults.
Recent Findings
Seven ...trials (
n
= 33 to 409) were included. The quality of evidence was mixed. In 2 trials, integrated interventions led to greater improvements in both obesity and depression over 12 months, compared with usual care. Of 4 trials comparing integrated interventions with a standalone obesity intervention, 2 showed incremental effects on depression only, and 2 did not detect a significant effect for either outcome. One 3-arm trial compared an integrated intervention with standalone obesity and depression interventions and only detected incremental effects on obesity when compared with a standalone depression intervention.
Summary
The effects of integrated interventions for comorbid obesity and depression are varied but promising. Implications for future research to guide intervention optimization and implement integrated interventions in clinical practice are provided.
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