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Carbonization treatment contributes to improvement of tribological properties of friction composites. Pure Non-asbestos organic (NAO) friction raw materials were selected, friction composite specimens had been made using a new mixing process and carbonization treatment. Two types of specimens had been prepared to evaluate their performance, one was carbonized a pure non-asbestos organic friction composite specimen and the other was an original brake metal linings of a certain brand of vehicles. Two friction composites were evaluated by brake inertia dynamometer. Their performances were assessed according to the procedure in a European Union Automobile Standards (AK Master). Microscopic photographs of worn surfaces were obtained by scanning electron microscopy to characterize their tribological behavior and wear mechanism. The results showed that pure NAO friction composites had more suitable frictional properties, fade and recovery behavior than the copper-containing metal brake pad, but wear resistance was slightly lower. Carbonation promoted the formation of microporous structure in friction composites, which was helpful to reduce noise and vibration during work.

The corrosion characteristics and corrosion mechanism of the extruded ZK80 alloy with different states soaking in 3.5% NaCl solution at room temperature were analyzed via OM, SEM, EDS, XRD and static weightlessness method and other experimental analysis methods. The results show that when the aging temperature is constant, and the corrosion rate decreases with the lengthen of aging time, while when the corrosion time is constant, the corrosion rate increases with the increase in aging time. Appropriate aging treatment not only refines the grain of the alloy, but also precipitates the Mg–Zn phase which can effectively prevent the corrosion process and improve the anti-corrosion properties of the alloy. The main corrosion characteristics of the alloy are filamentary corrosion and pitting corrosion.

BackgroundInflammatory pseudotumors that grow on the omentum are relatively rare, and inflammatory pseudotumor most often involves the lung. As far as we know, the inflammatory pseudotumor of omentum, which is in the shape of beaded vesicles and contains gas, has never been reported in the literature. Case presentationwe report a 45-year-old Chinese woman who complained of epigastric pain with hematemesis for 9 hours, physical examination showed subxiphoid tenderness, previous history of gastric ulcer and repair of gastric perforation, laboratory examination showed slight increase of white blood cells and decrease of hemoglobin. Computed tomography showed dotted free gas in the abdominal cavity, and the perforation of the hollow organs was considered. The pathological results after emergency operation showed that histiocyte aggregation with multinucleated giant cell reaction could be seen in the omental tissue. Immunohistochemistry :ER (-), PR (-), PAX-8 (-), CK (mesothelial+), MC (mesothelial+), CR (mesothelial+), CD68 (histiocyte+), SMA (smooth muscle+). The abdominal pain was relieved after surgical resection of the tumor, and recovered well after symptomatic treatment.ConclusionInflammatory pseudotumor of omentum containing gas is easily diagnosed as perforation of hollow organs, with few clinical manifestations of acute abdomen, mostly non-specific, and a good prognosis. Understanding its clinicopathological features and pathological examination methods are helpful to diagnose the disease, so as to choose an appropriate treatment plan, and whether surgical treatment is better than conservative treatment remains to be further studied. The disease should be distinguished from perforation of hollow organs, but the source of gas is unknown. It may have something to do with past medical history.

The room temperature compression experiments of as-extruded AZ31 magnesium alloy under different loading speeds were carried out on a universal tensile testing machine. The fracture failure characteristics and mechanism of the alloy under different compression loading speeds were analyzed by scanning electron microscope (SEM) and optical microscope (OM). The results show that during the compression test, the crushed AZ31 magnesium alloy sample has a certain pier coarseness, the macro fracture of the sample is located at one third of the sample, and the macro fracture mode is 45° shear fracture with the sample axis; With the increase of loading speed, the coincidence degree of macro fracture becomes worse, and its compressive strength changes in an undulating manner. When the loading speed is 2mm/min, the compressive strength reaches the peak value of 413MPa, and the fracture morphology of the sample shows a typical flat and flat rock like ductile brittle mixed fracture. With the increase of loading speed, the proportion of brittle fracture components increases, the shape of shrinkage fracture is rock like fracture, and the fracture fluctuation is relatively slow, the dimples distributed on the fracture surface are elongated and torn, and the compression speed has no obvious effect on the fracture morphology.

To comparatively evaluate the clinical outcomes of super-mini percutaneous nephrolithotomy (SMP) and mini-percutaneous nephrolithotomy (Miniperc) for treating urinary tract calculi of2 cm.An international multicentre, retrospective cohort study was conducted at 20 tertiary care hospitals across five countries (China, the Philippines, Qatar, UK, and Kuwait) between April 2016 and May 2019. SMP and Miniperc were performed in 3525 patients with renal calculi with diameters of2 cm. The primary endpoint was the stone-free rate (SFR). The secondary outcomes included: blood loss, operating time, postoperative pain scores, auxiliary procedures, complications, tubeless rate, and hospital stay. Propensity score matching analysis was used to balance the selection bias between the two groups.In all, 2012 and 1513 patients underwent SMP and Miniperc, respectively. After matching, 1380 patients from each group were included for further analysis. Overall, there was no significant difference in the mean operating time or SFR between the two groups. However, the hospital stay and postoperative pain score were significantly in favour of SMP (both P 0.001). The tubeless rate was significantly higher in the SMP group (72.6% vs 57.8%, P 0.001). Postoperative fever was much more common in the Miniperc group (12.0% vs 8.4%, P = 0.002). When the patients were further classified into three subgroups based on stones diameters (2-3, 3-4, and4 cm). The advantages of SMP were most obvious in the 2-3 cm stone group and diminished as the size of the stone increased, with longer operating time in the latter two subgroups. Compared with Miniperc, the SFR of SMP was comparable for 3-4 cm stones, but lower for4 cm stones. There was no statistical difference in blood transfusions and renal embolisations between the two groups.Our data showed that SMP is an ideal treatment option for stones of4 cm and is more efficacious for stones of 2-3 cm, with lesser postoperative fever, blood loss, and pain compared to Miniperc. SMP was less effective for stones of4 cm, with a prolonged operating time.

The effect of two-stage aging on the microstructure and properties of as-extruded 7075 aluminum alloy was studied by means of hardness, conductivity and microscope. The results show that: in the process of solution and primary aging, with the increase of heat treatment time, the hardness and electrical conductivity of the alloy have little improvement, but there is a strong linear correlation between hardness and electrical conductivity, that is, the change of hardness and electrical conductivity presents the same trend; after two-stage aging treatment, with the extension of aging time, the hardness of the alloy first increases, reaches the peak value, and then decreases gradually, the hardness and conductivity have a strong negative linear correlation; and with the increase of aging temperature and aging time, the hardness of the alloy decreases by 9.6%, while the conductivity increases by 18.6%.

In this paper, the microstructure of as-forged AZ81 Mg alloy before and after heat treatment was analyzed by means of optical microscope and XRD, the corrosion behavior of as-forged AZ81 Mg alloy after heat treatment with different concentrations of NaCl solution was studied by static immersion weight loss method. The results show that: after solution aging heat treatment at 400°C×0.5h+200°C×20h, the grain size of the alloy is more uniform, but the effect on the average grain size is not obvious; when the corrosion time is fixed, the corrosion rate of as-forged AZ81 Mg alloy increases rapidly with the increase of NaCl concentration; with the extension of corrosion time, the corrosion rate of as-forged AZ81 magnesium alloy increases in a fluctuating manner, and then in a fluctuating decreases after reaching the peak value, and after 72h of etching, the corrosion rate of the alloy is basically unchanged; meanwhile, the corrosion in as-forged AZ81 magnesium alloy shows obvious filamentous propagation characteristics, and these filamentous corrosion characteristics basically extend and distribute along the grain boundary.

The evolution of microsturcture and mechanical properties of ZYK530 Magnesium alloy during extrusion and die forging compound forming process were studied and analyzed. The results show that the as-cast ZYK530 alloy mainly consists of a-Mg matrix and I-Mg3Zn6Y and a small amount of W-Mg3Y2Zn3 and Mg2Zn3 phases. During extrusion to die forging forming, the grain size of as-cast ZYK530 Magnesium alloy is refined and uniform under the action of three-dimensional compressive stress and high temperature deformation. The I-Mg3Zn6Y phase of ZYK530 magnesium alloy decrease relatively, while the distribution of W-Mg3Y2Zn3 is more obvious, a small amount of Z-Mg12ZnY and Mg-Zn phases and undetermined phases can be observed in the matrix. Tensile test results show that the tensile strength, yield strength and elongation of extruded preformed specimens are increase by 32.6%, 18% and 18% respectively compared with as-cast specimens. The mechanical properties of final forged specimens are improved by 9%, 38.6% and 23% respectively compared with those of extruded preformed specimens. The fracture mechanism changes form as-cast cleavage fracture to mixed fracture mechanism of toughness and brittleness.

Background The association between vitamin D receptor gene Bsm I (rs1544410) polymorphism and prostate cancer (PCa) risk has been investigated by numerous previous studies, which yielded inconsistent results. We conducted this meta-analysis to derive a relatively precise description of this association. Methods All studies published up to December 2017 were identified via a systematic search of PubMed, Embase, and China National Knowledge Infrastructure databases. Pooled odds ratios (ORs) with their 95% confidence intervals (CIs) were estimated to describe the strength of the relationship between Bsm I and PCa risk. Results In this meta-analysis, 27 studies with 9,993 cases and 9,345 controls were included. The pooled results revealed that Bsm I polymorphism was not associated with PCa risk in the overall analysis. Moreover, no significant relationship was found in the subgroup analyses by ethnicities, genotyping methods, Hardy–Weinberg equilibrium status, and Gleason score. In the stratified analysis by the source of controls and clinical stages, controls of benign prostatic hyperplasia (BPH) seemed to be in the particular groups in which the association of PCa risk with Bsm I polymorphism was significant (Bb vs. bb: OR=0.643, 95% CI=0.436–0.949, p=0.026; BB/Bb vs. bb: OR=0.627, 95% CI=0.411–0.954, p=0.029; B vs. b: OR=0.715, 95% CI=0.530–0.965, p=0.029). Conclusion Our results suggest that Bsm I polymorphism is weakly associated with PCa risk, and hence, it cannot be considered as a predictor of the occurrence and development of PCa in clinical practice. Future studies with a larger number of samples are needed to verify our results.

Numerous previous studies reported the association of Vitamin D receptor gene Taq Ipolymorphism with prostate cancer risk, however these results were controversial. In order to provide a relatively comprehensive description of this relationship, we conducted this meta-analysis by searching PubMed, Embase, and China National Knowledge Infrastructure. Finally, 36 studies with 8,423 cases and 8,887 controls were included. Taq I polymorphism was found to marginally increase the prostate cancer risk in recessive genetic model (tt/Tt vs. TT: Odds Ratio (OR) = 0.89, 95% Confidence Interval (CI) = 0.80–1.00, p = 0.05) and allele genetic model (t vs. T allele: OR = 0.91, 95% CI = 0.84–0.99, p = 0.003) in the overall analysis. Subgroup analyses showed that significant increased risk was found in Asians in homozygote model (tt vs. TT: OR = 0.63, 95% CI = 0.41–0.95, p = 0.029) and allele genetic model (t vs. T: OR = 0.78, 95% CI = 0.67–0.90, p = 0.002), and in the subgroup of population-based controls in all the genetic models. These results suggest that Taq Ipolymorphism might be a risk factor of prostate cancer risk, especially in Asians. It could be considered as a promising target to predict the prostate cancer risk for clinical practice.

PACE4 plays an important role in prostate cancer (PCa) proliferation and aggression, which might provide a useful target against prostate cancer. In this study, we had strived to find some key miRNAs to decrease malignancy and invasiveness of PCa through regulating PACE4 expression.Clinically pathological analysis of immunohistochemistry/in situ hybridization was carried out to detect the relationship between PACE4 expression/miRNAs and the malignancy of prostate mass. Prostate cell lines (DU145, C4-2, and BPH-1) were cultured for growth curve, immunocytochemistry analysis, colony formation, Matrigel invasion, and transcriptional/translational expression assay of PACE4-related signaling molecules for confirming the relationship. MiRNAs targeting PACE4 were predicted, validated and further-corroborated using bio-software, real-time PCR, luciferase reporter assay and transfection of miRNA mimics and inhibitor.It was suggested that PACE4 might reflect the pathological malignancy of prostate lesion from pathology analysis. Moreover, DU145 cells, the highest PACE4-level and related TF expression indicated of the strongest malignancy and invasiveness. It was significantly found that miR-124 was presented with the biggest odd to target PACE4-3'UTR, the capability of decreasing PACE expression and slowing down cell growth and cell invasion.It was clear that PACE4 level was closely associated with malignancy and invasiveness of PCa in vivo or in vitro MiR-124, played a crucial role inhibiting PACE4 transcription thus exhibiting obvious effects of antiproliferation and antiaggression of PCa.