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Nondestructive machining of optical components and smoothing of surface/subsurface damage generated by pre-processing is a major challenge for ultra-tight machining. The study analyzes the crack change during smoothing by quantitative layer-by-layer removal of Vickers indentations through atmosphere pressure plasma jet; the indentation change process is modeled and analyzed using Level Set Method (LSM) simulation. The results show that plasma jet processing can smooth the subsurface damage of fused silica optical components, and the LSM simulation verifies that the processing of cracks in fused silica components by plasma jet is dominated by each isotropic etching, and there are also each anisotropic etching during the change of cracks; and the depth of adjacent cracks can be judged by the moving direction of adjacent crack boundaries. [ABSTRACT FROM AUTHOR]

The optimal surgical procedure for minimal surgical intervention in symptomatic degenerative lumbar spinal stenosis (DLSS) is unknown. This article presents a method of minimally invasive decompression alone and reports the long-term outcomes and complications of patients treated with minimally invasive bilateral or unilateral laminotomy decompression performed by one surgeon. Patients with DLSS who underwent minimally invasive laminotomy decompression alone from March 2008 to October 2010 were included in the study, and 106 patients were followed up for at least 10 years. Clinical outcomes were assessed by Japanese Orthopedic Association, Oswestry Disability Index, and visual analog scale for back pain scores, and changes in walking tolerance and leg numbness were evaluated. Complications were recorded. A total of 106 patients who met the inclusion and exclusion criteria were included in the study (mean age = 64 years, range = 43–83). The Japanese Orthopedic Association, Oswestry Disability Index, and visual analog scale back pain scores of patients significantly changed between before surgery and at subsequent follow-up (P < 0.001). The walking tolerance and leg numbness of patients significantly improved (P < 0.001), and these functions were well maintained during follow-up. Complications included intraoperative dural tears (n = 5), a wound infection (n = 1), deep vein thrombosis (n = 1), and nerve root lesions on the asymptomatic side (n = 2), all of which recovered within 3 months. Minimally invasive laminotomy decompression is an effective procedure and achieves beneficial long-term clinical results for DLSS. [ABSTRACT FROM AUTHOR]

The erosion of the valve orifice can easily lead to the performance degradation of the hydraulic servo spool valve, which seriously affects the service life and reliability of the hydraulic servo system. In this paper, the erosion micro-morphological characteristics, erosive transient process visualization of solid particles, and factors affecting the erosion rate of the spool working edges were investigated. The results showed that there was a significant "edge collapse" phenomenon on the working edges of the spool, which was mainly characterized by surface peeling, notches, grooves, chamfers, and the radius of the fillet which fluctuated violently in the circumferential direction. The "smoothing, slipping, and somersaulting" evolution process started when the incident angle increased and the particles hit the valve orifice by a new visualization experiment model composed of the nozzle-baffle submerged jet. The erosion rate of the working edges also showed continuous fluctuations and violent changes, with strong scatter-like distribution characteristics. The erosion rate of the working edge in the up-flow field was approximately one time higher than that in the back-flow field. The erosion rate of the working edges increased as the oil viscosity and particle concentration increased. Under small openings, the impact frequency of particles and the working edge increased significantly. The distribution law of the erosion rate of the working edge agreed with the distribution characteristics of the erosion fillet radius of the working edges. The erosion rate variance was defined, which can be used to quantify the circular distribution of erosion rate. This study provides further understanding of the mechanism and influencing factors of the hydraulic servo spool valve erosion. • A significant "edge collapse" phenomenon on the working edges of the spool characterized by surface peeling, notches, grooves, chamfers. • A new visualization experiment model was designed to simulate the particle impact working edge of hydraulic servo spool valve. • Erosion rate variance, as a new parameter was found and defined to assess the dispersion of the orifice erosion rate. • Provides further understanding of the mechanism and influencing factors of the hydraulic servo spool valve orifice erosion. [ABSTRACT FROM AUTHOR]

Plasma processing has been widely reported as an effective tool in relieving or removing surface/subsurface damage induced by previous mechanical machining process. However, the surface morphology evolution during removing the damage using plasma processing is rarely reported. In this research, this procedure is studied based on experiments and robust numerical models developed on the basis of Level Set Method (LSM). Even if some unique properties of plasma etching are observed, such as particle redistribution, the dominant role of isotropic etching of plasma processing is verified based on experiments and 2D LSM simulations. With 2D LSM models, the damage removal process under various damage characteristics is explored in detail. Corresponding peak-to-valley roughness evolution is investigated as well. Study on morphology evolution is also conducted through the comparison between experiments and 3D LSM computations. The modeling results and experiments show good agreement with each other. The trends of simulated roughness evolution agree with the experiments as well. It is revealed that the plasma processing may end up with a planar surface depending on the damage characteristics. The planarization procedure can be divided into four parts: crack opening and pit formation; pit coalescing and shallow pits subsumed by deep ones; morphology duplicate etching; and finally a planar and damage free surface. [ABSTRACT FROM AUTHOR]

Tuberculosis (TB) causes about 10 million new cases and 1.5 million deaths every year, as the World Health Organization's Global Tuberculosis Report shows. We aimed to investigate the association between short-term exposure to particulate pollutants and the risk of tuberculosis outpatient visits in 16 cities of Anhui Province, China, during the period 2015–2020, and to provide more evidence for the relationship between tuberculosis and air pollution. In this study, we analyzed the data using a variety of models, including Poisson's generalized linear regression model, distributed lag non-linear model (DLNM) and random effects model. We assessed the relationship between particulate matter exposure and tuberculosis using a 28-day cumulative lag effect for every 10 unit increases in pollutant concentration and 95% CI. We performed stratified analyses for gender and age. Age stratification included <18 years old group, 19–64 years old group and >64 years old group and gender stratification included male group and female group, and then we performed a sensitivity analysis to test the stability of the results. The overall effect values of PM2.5 and PM10 were RR = 1.031 (95%CI: 1.019–1.043) and RR = 1.023 (95%CI: 1.016–1.030), respectively. Estimation for individual cities showed that the strongest association between PM2.5 and the risk of TB outpatient visits was observed in Tongling, with an RR of 1.136 (95%CI: 1.0261–1.2583), also the PM10 in Suzhou, with an RR of 1.0629 (95%CI: 1.0421–1.0842). Stratified analysis showed that particulate matter exposure had a more significant impact on males and the elderly, and that there was little association between particulate matter exposure and TB risk in children and adolescents. Exposure to PM2.5 and PM10 increases the risk of TB outpatient visits. Males and the elderly are vulnerable groups, and different prevention and control strategies should be developed for different groups to reduce the burden of TB. • China's first province-wide study on the TB outpatient visits and particulate pollutants. • Exposure to particulate pollutants increases the risk of tuberculosis outpatient visits. • Exposure to particulate pollutants has a greater impact on male and the elderly. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the association between receptor activator of nuclear factor-kappaB ligand (RANKL) gene polymorphisms and the susceptibility to ankylosing spondylitis (AS) in a Chinese Han population. Methods: Three hundred and fifty-two AS patients and 299 age- and gender-matched controls were recruited in this study. Peripheral blood samples were collected from all the subjects and the genomic DNA was then extracted. Three single nucleotide polymorphisms (SNPs) of the RANKL gene (rs2277438, rs7984870 and rs9533156) were genotyped using the TaqMan assay. The frequencies of alleles and genotypes were compared between AS patients and normal controls. Results: The distributions of genotype frequencies in rs2277438 were significantly different between AS patients and normal controls ( P < 0.05). The frequency of G allele of SNP rs2277438 in AS patients was significantly higher than that in normal controls ( P < 0.05). The frequencies of genotypes with G allele (GG and AG) were significantly higher in AS patients when compared with normal controls (OR = 1.573, 95 % CI 1.151-2.150, P < 0.05). Neither the genotype frequencies nor the allele frequencies of rs7984870 and rs9533156 were found to be significantly different between AS patients and normal controls ( P > 0.05). Conclusions: The current study demonstrated that SNP rs2277438 of the RANKL gene was associated with the susceptibility of AS in a Chinese Han population. Genotypes with G allele (GG and AG) were identified as the risk factors for the occurrence of AS. [ABSTRACT FROM AUTHOR]