Dissolved Heavy Metal Pollution and Assessment of a Karst Basin around a Mine, Southwest China.

Karst water quality is one of the most important environmental issues in karst areas. The study's purpose was to investigate dissolved heavy metal pollution and health risk assessment in karst water basins around mines. River water and groundwater samples were analyzed by principal component analysis, correlation analysis, water quality index, hazard quotient, and hazard index. Median concentrations of dissolved heavy metals in the Sidi River were similar to the world average with a slightly alkaline characteristic. The concentrations of most dissolved heavy metals in river water were higher than those in groundwater. The concentrations of Zn, Pb, and Cd around the mine exceeded the limits of drinking water indicators. The poor water quality samples with high water quality index values were distributed around the mine. Lead (Pb), Zn, As, Cd, and Cr were potentially threatening metals in the study area. The pollution level of dissolved heavy metals in the Sidi River was at a medium level compared with other rivers worldwide. Principal component analysis and correlation analysis showed that Cu, Pb, Zn, Cd, Mn, Fe, As, and Sr mainly came from mine drainage; Ca2+, Mg2+, and Cr mainly came from the contribution of carbonate rocks; Na+ and K+ were related to local human agricultural activities. The concentrations of dissolved heavy metals in groundwater were affected by karst aquifers. The results of this study can provide a data reference for water resources prevention and human health protection in the Sidi River's karst basin and similar karst basins.

Optimized strategy of rotational atherectomy of underexpanded coronary stents in patients with acute coronary syndrome.

BACKGROUND: Stent under-expansion is a main cause of acute coronary syndrome (ACS), which can lead to serious clinical outcomes. The rotational atherectomy of underexpanded coronary stents (academically called stent ablation, SA) by intravascular ultrasound (IVUS) may provide more visual reference in the intervention. We aim to analyze the procedural and long-term outcomes of the optimized strategy of SA in patients with ACS and to provide real-world data on this technique. METHODS: A total of 11 patients with ACS who underwent SA between April 2017 and January 2019 were analyzed. Clinical follow-ups were obtained either by telephone call or by scheduled visit. Clinical end-points included periprocedural and postprocedural myocardial infarction, stent thrombosis, target lesion revascularization, and major adverse cardiac events. RESULTS: The mean age of patients was 69.6±6.5 years, and five (45.5%) patients were males. All cases presented with unstable angina and were admitted with ACS. All patients required at least two burrs during the intervention and the size of the burr was selected based on the data of minimum lumen diameter (MLD), and the first and the second burr/stent MLD ratios were 0.93 (0.88-0.99) and 1.09 (1.02-1.14), respectively. Nine patients were treated with drug-eluting stents and two were treated with drug-coated balloons. There were no complications including no flow, perforation, or burr entrapment during the intervention. No in-hospital deaths or major adverse cardiac events were documented during the follow-up period. In our study, less contrast agent and a lower dose of radiation were used during the intervention. CONCLUSIONS: SA guided by IVUS can reduce the risk of complications, assess the results of surgery, inform the selection of stent size, and decrease the required dose of radiation and contrast.

Self-inhibition effect of metal incorporation in nanoscaled semiconductors.

There has been a persistent effort to understand and control the incorporation of metal impurities in semiconductors at nanoscale, as it is important for semiconductor processing from growth, doping to making contact. Previously, the injection of metal atoms into nanoscaled semiconductor, with concentrations orders of magnitude higher than the equilibrium solid solubility, has been reported, which is often deemed to be detrimental. Here our theoretical exploration reveals that this colossal injection is because gold or aluminum atoms tend to substitute Si atoms and thus are not mobile in the lattice of Si. In contrast, the interstitial atoms in the Si lattice such as manganese (Mn) are expected to quickly diffuse out conveniently. Experimentally, we confirm the self-inhibition effect of Mn incorporation in nanoscaled silicon, as no metal atoms can be found in the body of silicon (below 1017 atoms per cm-3) by careful three-dimensional atomic mappings using highly focused ultraviolet-laser-assisted atom-probe tomography. As a result of self-inhibition effect of metal incorporation, the corresponding field-effect devices demonstrate superior transport properties. This finding of self-inhibition effect provides a missing piece for understanding the metal incorporation in semiconductor at nanoscale, which is critical not only for growing nanoscale building blocks, but also for designing and processing metal-semiconductor structures and fine-tuning their properties at nanoscale.

Genomic Analysis of Soybean PP2A-B ' ' Family and Its Effects on Drought and Salt Tolerance.

Abiotic stresses induce the accumulation of reactive oxygen species (ROS) and significantly affect plant growth. Protein phosphatase 2A (PP2A) plays an important role in controlling intracellular and extracellular ROS signals. However, the interaction between PP2A, ROS, and stress tolerance remains largely unclear. In this study, we found that the B ' ' subunit of PP2A (PP2A-B ' ' ) can be significantly induced and was analyzed using drought- and salt-induced soybean transcriptome data. Eighty-three soybean PP2A-B ' ' genes were identified from the soybean genome via homologous sequence alignment, which was distributed across 20 soybean chromosomes. Among soybean PP2A-B ' ' family genes, 26 GmPP2A-B ' ' members were found to be responsive to drought and salt stresses in soybean transcriptome data. Quantitative PCR (qPCR) analysis demonstrated that GmPP2A-B ' ' 71 had the highest expression levels under salt and drought stresses. Functional analysis demonstrated that overexpression of GmPP2A-B ' ' 71 in soybeans can improve plant tolerance to drought and salt stresses; however, the interference of GmPP2A-B ' ' 71 in soybean increased the sensibility to drought and salt stresses. Further analysis demonstrated that overexpression of GmPP2A-B ' ' 71 in soybean could enhance the expression levels of stress-responsive genes, particularly genes associated with ROS elimination. These results indicate that PP2A-B ' ' can promote plant stress tolerance by regulating the ROS signaling, which will contribute to improving the drought resistance of crops.

HPV vaccination acceptability among men who have sex with men in Urumqi, China.

BACKGROUND: Human papillomavirus (HPV) infection is common among men who have sex with men (MSM), especially among Human Immunodeficiency Virus (HIV)-infected MSM. The prevalence of HPV among MSM, accounts for the higher incidence of HPV-related cancer observed in this population. It is well known that targeted HPV vaccination is an effective way to prevent HPV infection; an intervention which could be beneficial for a high-risk group such as MSM. The current study aimed to assess the attitudes towards and acceptability of the HPV vaccine among MSM in in Urumqi, China. METHODS: A total of 253 HIV-uninfected and 205 HIV-infected MSM (in Urumqi, China participated in the current cross-sectional study. Information on HPV-related knowledge, willingness to be vaccinated as well as demographic data were collected through a self-administered survey. A logistic regression model was applied to determine the predictors of HPV vaccine acceptability among the population. RESULTS: The survey results indicated that only 218 (47.6%) of MSM questioned were aware of the term HPV, nevertheless, once awareness was established the prevalence of acceptability of free HPV vaccine was recorded at 96.7% of the total MSM sample. However, HIV-uninfected and HIV-infected MSM demonstrated significantly different attitudes in regard to their acceptability of free HPV vaccination (94.9% vs. 99.0%, p < 0.001) as well as their willingness to pay for the HPV vaccination (64.8% vs. 80.5%, p < 0.001), with the HIV-infected group being significantly more receptive towards HPV immunization. A multivariate logistic regression analysis indicated that local residency, employment status, hepatitis B vaccination status, previous awareness of HPV and HIV status were independent predictors of the participants' willingness to pay for HPV vaccination. CONCLUSIONS: Participants in the current study demonstrated poor knowledge of HPV but the majority of MSM were willing to accept HPV vaccine after consultation; with HIV-infected MSM displaying higher acceptability towards a potential HPV vaccination than HIV-uninfected MSM. MSM who were previously aware of HPV were more likely to be willing to pay for HPV vaccine.

Prevalence and risk factors of anal human papillomavirus infection among HIV-negative men who have sex with men in Urumqi city of Xinjiang Uyghur Autonomous Region, China.

BACKGROUND: Infection with human papillomavirus (HPV) is the most common sexually transmitted infection among men who have sex with men (MSM). Study on prevalence and risk factors of anal HPV infection among HIV-negative MSM in Northwestern China was rare. METHODS: We performed a cross-sectional study of HPV prevalence using anal swab specimens among HIV-negative MSM in Urumqi city of Xinjiang Uyghur Autonomous Region, China between April 1st and October 30th in 2016. Prevalence of any anal HPV infection, high-risk and low-risk HPV infection was estimated. Risk factors associated with any anal HPV infection was analyzed using univariate and multivariate logistic regression models. RESULTS: Among 538 potential participants, 500(92.9%) were recruited in this study. The genotyping results of anal HPV infection were available for all. Of them, 259 (51.8%), 190 (38.0%) and 141(28.2%) were positive for at least one of the targeted 37 HPV genotypes, high-risk HPV genotypes, and any low-risk HPV genotypes. The most prevalent anal HPV genotype was HPV 6(11.8%), followed by HPV 16(11.2%), HPV 11(10.8%), HPV 51(7.0%) and HPV 18(5.4%).Among those infected with at least one of the targeted 37 anal HPV genotypes, 75(29.0%), 155(59.8%) and 191(73.7%) were infected with 2-valent, quadrivalent and 9-valent HPV vaccine-covered genotypes. Receptive anal intercourse in the past year was the only predictor of any anal HPV infection in multivariate logistic regression model. CONCLUSION: Prevalence of any anal HPV infection and high-risk HPV infection among HIV-negative MSM in Urumqi city of Xinjiang is high. The majority of genotypes detected in our study were covered by quadrivalent and 9-valent HPV vaccines. Regular anal exams and early HPV vaccination among MSM may be considered in future HPV prevention programs in Xinjiang, China.

Helium Ion Microscope Fabrication Causing Changes in the Structure and Mechanical Behavior of Silicon Micropillars.

Silicon is used as a prominent case to demonstrate the dramatic effects of helium ion microscope nanofabrication. Structurally, a submicrometer Si pillar can turn completely amorphous at He+ doses typically used for micromachining, forming nanobubbles at higher doses. In terms of mechanical properties, the flow stress decreases markedly with increasing dosage, and the softened amorphous Si exhibits spread-out plastic flow.

Polysynthetic twinned TiAl single crystals for high-temperature applications.

TiAl alloys are lightweight, show decent corrosion resistance and have good mechanical properties at elevated temperatures, making them appealing for high-temperature applications. However, polysynthetic twinned TiAl single crystals fabricated by crystal-seeding methods face substantial challenges, and their service temperatures cannot be raised further. Here we report that Ti-45Al-8Nb single crystals with controlled lamellar orientations can be fabricated by directional solidification without the use of complex seeding methods. Samples with 0° lamellar orientation exhibit an average room temperature tensile ductility of 6.9% and a yield strength of 708 MPa, with a failure strength of 978 MPa due to the formation of extensive nanotwins during plastic deformation. At 900 °C yield strength remains high at 637 MPa, with 8.1% ductility and superior creep resistance. Thus, this TiAl single-crystal alloy could provide expanded opportunities for higher-temperature applications, such as in aeronautics and aerospace.

Endothelialization and in-stent restenosis on the surface of glycoprotein IIIa monoclonal antibody eluting stent.

Since the percutaneous transtuminal coronary angioplasty was introduced into China in 1984, this procedure has become widely accepted as an important step in coronary revascularization. This study shows the effect of the monoclonal antibody (mAb) on the platelet glycoprotein IIIa receptor during endothelialization and in-stent restenosis by implanting the mAb-eluting stents into iliac arteries of rabbits. The hard tissue cross sections of the stent-implanted arterial segments were made by polymethylmethacrylate embedding. Arterial intima proliferation was observed and analyzed. The endothelialization of the stent surface was observed using scanning electron microscope, whereas the ultrastructure of the neointima was observed using transmission electron microscope. After one month of stent implantation, the surfaces of both groups were covered by intact endothelial layers, but the neointimal areas and the ratio of stenosis were significantly lesser in the mAb-eluting stent group (p < 0.01). After 3 months, the ratio of stenosis in the mAb-eluting stent group was 14.67 ± 0.79, whereas that of the bare stent group was 21.58 ± 1.76 (p < 0.01). Therefore, the mAb eluting from the stent surface has the potential to accelerate endothelialization, prevent thrombosis formation due to the interaction of stent with blood, and decrease the stenosis ratio by inhibiting neointima proliferation.

[Role of inflammation factors in impaired glucose tolerance and sleep apnea/hypopnea syndrome in pregnant women].

OBJECTIVE: To investigate the possible role of inflammation factors in the pathogenesis of impaired glucose tolerance (IGT) with concurrent obstructive sleep apnea/hypopnea syndrome (OSAHS) in pregnant women. METHODS: Twenty-five pregnant women with IGT and concurrent OSAHS and 35 pregnant women with IGT but not OSAHS were monitored for all night polysomnography (PSG), and the apnea hypopnea index (AHI) and the lowest pulse oxygen saturation (LSpO2) were recorded. The body mass index, glycated serum protein (GSP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured in these women. RESULTS: IL-6 and TNF-α levels increased significantly in women with IGT and OSAHS as compared with those in women without OSAHS. AHI showed significant positive correlations to GSP, IL-6 and TNF-α, whereas LSpO2 was inversely correlated to GSP, IL-6 and TNF-α. IL-6 and TNF-α were significantly correlated to GSP, with correlation coefficients of 0.510 and 0.476, respectively. CONCLUSION: The inflammatory factors may play important roles in IGT complicated by OSAHS in pregnant women, and as a potential risk factor, OSAHS may contribute to the occurrence of progression of IGT.

[Immune function changes in patients with obstructive sleep apnea hypopnea syndrome].

OBJECTIVE: To explore the potential changes in the immune function of patients with obstructive sleep apnea hypopnea syndrome (OSAHS). METHODS: We carried out a retrospective cross-sectional study of 187 patients with established OSAHS and 20 healthy subjects (control). For all the patients, the medical history was carefully examined, and overnight sleep monitoring was carried out with detection of the humoral and cellular immunity. RESULTS: We found a significant increase in the levels of C3 and a decrease in both the IgM level and NK cell percentage in OSAHS patients as compared to the control group (P<0.01). Correlation analysis indicated that C3 was positive correlated to AHI but inversely to the lowest pulse oxygen saturation (LSpO(2)); IgM showed a mild positively correlation to LSpO(2), and NK cells had a mild inverse correlation to AHI. The other immunological indices were not found to undergo noticeable changes or show correlations in OSAHS. CONCLUSION: Immune function changes occur in patients with OSAHS, characterized primarily by deteriorations in the humoral and cellular immunity.

[The clinical study of 120 cases total cystectomy and W shape orthotopic ileal neobladder].

OBJECTIVE: To study advantages or disadvantages of total cystectomy and W shape orthotopic ileal neobladder. METHODS: Radical cystectomy and ileal new bladder was performed antegradly and retrogradly for 120 male patients. For the construction of the reservoir, the 40 cm ileal segment was isolated along its antimesenteric border and then arranged into a W shape. The incised ileum was sutured blanketly to create urine bag. The ureters were replanted at the two corners of the W shape by way of creating nipple. RESULTS: The first 50 cases took 210-300 min with a mean of 270 min. The later 70 cases took 110-205 min with a mean of 143 min. Ninety-one of 120 cases had been followed up for 2-88 months with a mean of 30 months. Eighty-five cases had achieved excellent daytime continence, whereas 71 cases had nighttime continence. There were 9 cases of hydroureter and 2 cases of moderate hydronephrosis. Renal function of 2 cases were slightly abnormal. Hypokalemia occurred in 6 cases, and there was no metabolic-disorder. On voiding cystography, only 1 case showed reflux in right ureter. Only 2 case suffered from cancer recurrence of urethral and no patient suffered from cancer recurrence of neobladder. Twenty patients were evaluated by urodynamic examine. The urine flow curve showed continual shape in 12 cases, while intermittent shape in 8 cases. Voiding cystourethrography showed the neobladder outlet presented funnel shape and open well in continual group, while lack of funnel shape or bladder neck opened badly in intermittent group. CONCLUSION: The modified total cystectomy and ileal new bladder are effective and reliable treatment for patients.