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Objectives For migrant female sex workers (FSWs) at the Sino-Vietnamese border, the impact of work time in their current location on the spread of HIV/AIDS is not clear. Methods Data were collected from the Sino-Vietnamese border cities of Guangxi, China. Migrant FSWs working in these cities were studied. FSWs who worked less than 6 months in their current location were assigned to the short-term work group (ST FSWs), and FSWs who worked equal to or longer than 6 months in their current location were assigned to the long-term work group (LT FSWs). Logistic regression was performed to examine the impact of work time in the current location and factors associated with HIV infection. Results Among the 1667 migrant FSWs, 586 (35.2%) and 1081 (64.9%) were assigned to the ST FSW and LT FSW groups, respectively. Compared to LT FSWs, ST FSWs were more likely to be of Vietnamese nationality, be less than 18 years old when they first engaged in commercial sex work, and have a low-level of HIV-related knowledge and had higher odds of using condoms inconsistently, having more male clients, having no regular male clients, and having a history of male clients who used aphrodisiacs but lower odds of receiving free condoms distribution and education/HIV counselling and testing programme. The analysis of factors associated with HIV infection revealed that Vietnamese FSWs, less than 18 years old when they first engaged in commercial sex work, having no regular male clients, and having lower average charge per sex transaction were correlated with HIV infection. Conclusion FSWs with short-term work at the Sino-Vietnamese border had a higher risk of risky sex and were correlated with HIV risk factors. Vietnamese FSWs were at higher risk of HIV infection, and they were more likely to have short-term work. More targeted HIV prevention should be designed for new FSWs who recently began working in a locality to further control the spread of HIV, particularly cross-border FSWs.

Antibiotics are increasingly detected in fish caught in ice-free waters, but information on fish caught in ice-sealed waters is insufficient. The concentrations of 23 antibiotics in the gills, muscles, kidneys, livers, biles, and brains of Cyprinus carpio and Hypophthalmichthys nobilis caught during winter fish-hunting activities in Chagan Lake, Haernao Reservoir, and Shitoukoumen Reservoir were systematically studied to ascertain the variations among fish species and fishing regions, tissue distribution, and bioaccumulation, as well as the potential risk to humans via the consumption of contaminated fish. The results indicated that the individual antibiotic concentration in tissues ranged from undetectable to 35.0 ng/g ww. The total antibiotic concentration in fish muscles from Shitoukoumen Reservoir was lower than that from Chagan Lake and Haernao Reservoir, but showed no significant difference between Cyprinus carpio and Hypophthalmichthys nobilis. Chloramphenicols had a high proportion in most fish tissues ranging from 28.3% to 44.0%, and the antibiotics were mainly distributed in the livers with a total concentration of 54.8 ± 9.9 ng/g ww. The mean values of bioaccumulation factors (BAF) of antibiotics in tissues ranged from 79.4 to 1000 L/kg, with the higher values found in the fish livers. The hazard quotient and hazard index value of antibiotics in the muscles of fish from ice-sealed were less than 1, indicating a negligible risk to human health via the consumption of fish muscles. This study revealed that the total antibiotic concentration in muscles showed spatial variations but not fish species-dependence. The antibiotics mainly accumulated in the livers. In addition, the target antibiotic concentrations in the muscles of fish from ice-sealed waters met the safe for consumption criteria.

Greenhouse gas (GHG) emissions from soil carbon and nitrogen cycles during freeze-thaw cycles (FTCs) provide positive feedback to climate warming. Biochar is a new type of soil conditioner that shows potential in soil GHG emissions reduction. To explore the mechanisms of the effects of biochar on soil GHG emissions in seasonally frozen soil areas, this study focused on farmland soil in the Songnen Plain. Variations in soil environmental factors, available carbon and nitrogen and microbial biomass were analyzed using an indoor simulation of soil FTCs. A structural equation model (SEM) was established to reveal the key driving factors and potential mechanism of biochar on soil GHG emissions under FTCs. The results showed that biochar increased carbon dioxide (CO2) emissions by 3.40% and methane (CH4) absorption by 2.52% and decreased nitrous oxide (N2O) emissions by 35.90%. SEM showed that soil temperature (ST) was the main environmental factor determining CO2 emissions and that soil moisture (SM) was the main environmental factor determining CH4 and N2O emissions. Soil available carbon and nitrogen and microbial biomass are important for soil GHG emissions as the reaction substrates and main participants in the biochemical transformation of soil carbon and nitrogen, respectively. This study showed that the application of biochar in farmland is a feasible choice to address climate change in the long term via soil carbon sequestration and GHG emissions reduction. The research results provide a theoretical basis and scientific guidance for soil GHG emissions reduction during FTCs in middle to high latitudes.

Since the COVID-19 pandemic, physicians concerned about the potential adverse effects of angiotensin converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs). To explore the relationship between ACEIs/ARBs and the risk of mortality and other clinical outcomes in COVID-19 patients, the authors conducted a systemic review and meta-analysis. An electronic search was performed from inception to November 12, 2020 in PubMed, Medline, EMBASE, ClinicalTrials, TRIP, the Cochrane Library, CNKI, Wanfang, and CBM database. Risk of bias was assessed using the Risk Of Bias In Non-randomized Studies of Interventions tool. The primary outcome was in-hospital all-cause mortality. Secondary outcomes included all-cause mortality measured at 30-day or longer term, mechanical ventilation, length of hospital stay, readmission, and cardiac adverse events. A total of 28 studies with 73 465 patients was included. Twenty-two studies with 19 871 patients reported the incidence of all-cause mortality. Results showed no association between using ACEIs/ARBs and risk of mortality crude odds ratio i¼ˆORi¼‰ of 1.02, 95% CI 0.71-1.46, p = .90, I2 = 88%, adjusted OR in 6260 patients of 0.96, 95% CI 0.77-1.18, p = .68, I2 = 0%. While six studies with 10 030 patients reported a lower risk of mortality in ACEIs/ARBs group hazard ratio (HR) of 0.53, 95% CI 0.34-0.84, p = .007, I2 = 68%. Similar association (for HR) was found in hypertension subgroup. There was no significant association for the secondary outcomes. Based on the available data, we concluded that ACEIs/ARBs is not associated with the risk of in-hospital all-cause mortality in COVID-19 patients, but may be associated with a decreased risk of 30-day all-cause mortality. Patients with hypertension may benefit from using ACEIs/ARBs.

Background The 15-item Geriatric Depression Scale (GDS-15) shows good performance in detecting depression among older persons, but its applicability has not been well studied in non-Western oldest-old adults and centenarians. This study aimed to evaluate the psychometric property of the GDS-15 and a simplified version among a large representative longevous population in China. Methods A total of 1624 individuals (786 oldest-old persons aged from 80 to 99 years; 838 centenarians aged 100+ years) participated in this study. Home interviews with structured questionnaires were conducted to collect sociodemographic data. Depressive symptoms were measured using the Chinese GDS-15 version. We implemented mixed methods for the psychometric evaluation of the GDS-15. Cronbach’s α coefficient and item-total correlation coefficients were used to evaluate the internal consistency. A standard expert consultation was conducted to test the content validity of each item. Multiple factor analyses were used to explore the optimal factor structure and measurement invariance. Results The α coefficient of the GDS-15 was 0.745, while two items impaired the overall consistency reliability. Nineteen experts rated the applicability for each item and provided removal suggestion. Five items with less validity were removed, and a simplified 10-item GDS model with three-factor structure was proposed as an optimal solution. The GDS-10 model showed factorial equivalence across age, sex, residence, and education in multi-group confirmatory factor analyses. Conclusions The original GDS-15 has acceptable internal reliability, known-group validity, and concurrent validity among Chinese community-dwelling oldest-old and centenarians; however we provided preliminary evidence indicating that individual items related to somatic function or social activities may not be applicable for this population. The modified GDS-10 can be proposed as a potentially more practical and comprehensible instrument for depression screening.

Background To analyze the trends of HIV-1 and syphilis prevalence as well as associated factors among local Chinese female sex workers (LCFSWs) and cross-border migrant female sex workers (CMFSWs) in Sino-Vietnam border cities in Guangxi, China. Methods A consecutive cross-sectional study was conducted from 2010 to 2018 in three border cities in Guangxi. The survey was conducted through face-to-face interview with a structured questionnaire. HIV-1 and syphilis infections were tested simultaneously. Cochran-Armitage analysis was used to assess the trends of HIV-1, syphilis and HCV prevalence, as well as the trend of risk behaviors, HIV/AIDS knowledge and prevention services. Multivariate logistics regression analysis was used to identify factors associated with HIV-1 and syphilis infection.Results Totally, 19873 LCFSWs and 1723 CMFSWs were enrolled. The overall prevalence of HIV-1 and syphilis infection was 0.91% and 5.14%, respectively. The HIV-1 prevalence among CMFSWs was higher than that among LCFSWs, without a declined trend. However, a downward trend was observed among LCFSWs. Overall, the main associated factors of HIV-1 infection among CMFSWs shifted from age >35 years old, staying in current residence for >12 months, self-reporting sexually transmitted infections (STIs) in the last year during 2010-2015 to inconsistent condoms use in commercial sex in last month, not receiving peer education and self-reporting STIs in the last year during 2016-2018. The main correlated factors of syphilis infection among CMFSWs changed from history of illicit drug use, staying in current residence for more than 12 months, self-reporting of STIs and inconsistent condoms use in commercial sex in the past month during 2010-2015 to working in low-tier venues, self-reporting of STIs in the last year, and sexing with commercial male clients who used aphrodisiac drugs during 2016-2018. For LCFSWs, the relative strong associated factors of HIV-1 infection shifted from receiving less than 6 years of education, illicit drugs use, and self-reporting STIs in the last year during 2010-2015 to sexing with commercial male clients who use aphrodisiac drugs and self-reporting of STIs during 2016-2018, while the main factors of syphilis infection changed from self-reporting STIs in the last year, history of illicit drug use and receiving less than 9 years of education during 2010-2015 to self-reporting of STIs in the last year, sexing with commercial male clients who use aphrodisiac drugs, and history of illicit drugs use during 2016-2018.Conclusions The relatively higher prevalence of HIV-1 infection and frequent risk behaviours among CMFSWs in border cities in Guangxi, indicating that CMFSWs is the high-risk population for HIV-1 infection and transmission in the region, and is the key population of HIV/AIDS prevention and control. Meanwhile, the change of HIV infection-associated risk factors over time suggests that HIV intervention strategies need to be changed accordingly.

Objectives: To evaluate whether proprotein convertase subtilisin/kexin type 9 inhibitor (PCSK9i) is associated with cardiovascular and safety events in statin-treated patients with cardiovascular risk. Methods: Electronic databases (Pubmed, Cochrane, MEDLINE, EMBASE, ClinicalTrials.gov) were searched through March 31, 2020. Included randomized clinical trials (RCTs) compared PCSK9i use with no PCSK9i in statin treated patients. Two investigators abstracted data and appraised risks of bias. A meta-analysis was performed to calculate risk ratios (RRs) and 95% CIs using fix-effects models. Adjudicated cardiovascular events (CVE) and adverse drug events (ADE) were defined as the primary outcome. Secondary outcomes were cardiovascular (CV) death, all-cause death, nonfatal myocardial infarction, ischemic stroke, serious ADE and injection-site reaction. Results: A total of 10 RCTs 50 053 participants were included. PCSK9i use was associated with signigicant reductions in the CVE (RR, 0.87 [95%CI, 0.83-0.91]; NNT, 54; P

China's HIV/AIDS epidemic continues to grow in rural and less developed areas. This consecutive cross-sectional study examines demographic and behavioral factors associated with HIV/STI infection, Hepatitis C (HCV) and other sexually transmitted infections (STIs) among Vietnamese female sex workers (FSW), a vulnerable population who cross into Guangxi, China. This study is a secondary data analysis of 303 Vietnamese and 4,348 Chinese FSWs recruited over seven years from two Chinese counties that border Vietnam. Logistic regression models compared demographics, HIV/STI status, HIV/AIDS-related knowledge, attitudes, and risk behaviors between Vietnamese FSWs and Chinese FSWs. Compared with Chinese FSWs, Vietnamese FSWs were younger, had attained lower education levels, were highly mobile, more likely to report using drugs, and were more vulnerable to HIV/STIs. Younger age, less educational attainment, shorter time in their current working location, no voluntary HIV testing in the last year, greater drug use, and not using condoms for all commercial sex in the last month were associated with higher HIV/STIs. In conclusion, several factors were associated with HIV/STI risk in Vietnamese cross-border FSWs. There is a pressing need to improve support systems for Vietnamese cross-border FSW and health system cooperation across the Chinese/Vietnamese border.

Additional file 1: Table S1. HIV-related behavior and access to preventive intervention services between the ST FSWs and LT FSWs. Table S2. Multivariate analysis of factors associated with low-level of HIV-related knowledge. Table S3. Multivariate analysis of factors associated with inconsistent condom use in the past month and lifetime illicit drug use. Table S4. Multivariate analysis of factors associated with male clients > 30 in the past month, no regular male clients in the past month and having a history of male clients used aphrodisiacs. Table S5. Multivariate analysis of factors associated with access to preventive intervention services.

Porous silica fibers were fabricated aiming to broaden the applications of SiO2 nanosphere materials. The fibers were built with SiO2 nanospheres via electrospinning and calcinations. At first, SiO2 nanospheres (synthesized by Stober method) were surface-modified using γ-aminopropyltriethoxysilane to obtain SiO2-NH2 nanospheres, which dispersed homogeneously in the solvent. Then, polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) were introduced in different weight ratios into the suspension. Subsequently, PAN/PMMA/SiO2 composites were electrospun, followed by preoxidization and calcination to transfer PAN into carbon form and to remove PMMA component. Thus, porous silica fibers were fabricated with SiO2 nanospheres binding together during carbonization and porous structure was formed. The porosity, pore size and pore volume of porous silica fibers were controllable by adjusting the content of SiO2 nanospheres and the weight ratio of PAN/PMMA. Accordingly, the drug adsorption and release performance of these porous silica fibers depended on their micro-structural features. The thus-obtained porous silica fibers displayed great potentials in applications such as drug carriers and adsorbents. Keywords: SiO2 nanosphere, Nanoporous fiber, Electrospinning, Calcination

A new type of polymer-infiltrated-ceramic-network composites (PICNs) was fabricated by infiltrating methacrylate-based monomers into partially sintered porous ceramics. The mechanical properties (flexural strength, flexural modulus, elastic modulus, Vickers hardness, fracture toughness) were investigated and compared with that of the natural tooth and common commercial CAD/CAM blocks. Our results indicated that sintering temperature and corresponding density of porous ceramics have an obvious influence on the mechanical properties, and PICNs could highly mimic the natural tooth in mechanical properties. The biocompatibility experiments evaluated through in vitro cell attachment and proliferation of BMSCs showed good biocompatibility. The mechanical properties and biocompatibility confirmed that PICN could be a promising candidate for CAD/CAM blocks for dental restoration.

Aims: β-Adrenergic receptors (ADRBs) play a pivotal role in cardiovascular disease. Recently, genetic polymorphisms of ADRB1 and ADRB2 have been suggested to be associated with cardiovascular events and all-cause mortality in coronary artery disease (CAD) patients, but the results of relevant studies are inconsistent and controversial. Therefore, we performed a meta-analysis to investigate the association between ADRB1 and ADRB2 polymorphisms with cardiovascular events and all-cause mortality in CAD patients. Materials and Methods: The PubMed, Ovid, EMBASE, Cochrane, and CINAHL databases were searched for eligible studies published before April 2018. A total of 5495 patients from eight studies were included in our meta-analysis. Results: We found that CAD patients harboring the ADRB2 rs1042714 Glu27 allele exhibited a positive association with cardiovascular events (risk ratio [RR] = 1.31, 95% confidence interval [CI]: 1.08–1.58, p = 0.006), but not with all-cause mortality (RR = 0.97, 95% CI: 0.70–1.35, p = 0.859), compared with patients who were Gln27 homozygotes. No other significant associations were observed between ADRB1 (rs1801252, rs1801253), ADRB2 (rs1042713, rs1800888) polymorphisms and cardiovascular events or all-cause mortality in CAD patients. Conclusion: This study suggests that the identified ADRB2 polymorphism could influence the outcomes of CAD patients, showing important clinical value.

Background. The association between lipoprotein-associated phospholipase A2 (Lp-PLA2) and stroke risk is inconsistent. We conducted a meta-analysis to determine whether elevated Lp-PLA2 is a risk factor for stroke. Methods. Studies were included if they reported Lp-PLA2 mass and/or activity levels and adjusted risk estimates of stroke. The primary outcome was overall stroke incidence. The combined results were shown as relative risks (RRs) with 95% confidence intervals (CI) for per 1 standard deviation (SD) higher value of Lp-PLA2 and the highest versus lowest Lp-PLA2 category. Results. Twenty-two studies involving 157,693 participants were included for analysis. After adjusting for conventional risk factors, the RRs for overall stroke with 1 SD higher Lp-PLA2 activity and mass were 1.07 (95% CI 1.02–1.13) and 1.11 (95% CI 1.04–1.19), respectively. The RRs of ischemic stroke with 1 SD higher Lp-PLA2 activity and mass were 1.08 (95% CI 1.01–1.15) and 1.11 (95% CI 1.02–1.22), respectively. When comparing the highest and lowest levels of Lp-PLA2, the RRs of stroke for Lp-PLA2 activity and mass were 1.26 (95% CI 1.03–1.54) and 1.56 (95% CI 1.21–2.00), respectively. Finally, when comparing the highest and lowest levels of Lp-PLA2, the pooled RRs of ischemic stroke for Lp-PLA2 activity and mass were 1.29 (95% CI 1.07–1.56) and 1.68 (95% CI 1.12–2.53), respectively. Conclusions. Elevated baseline Lp-PLA2 levels, detected either by activity or mass, are associated with increased stroke risk.

Objective: Shared genetic variants in ADIPOR1 have been identified as closely related to coronary artery disease (CAD), type 2 diabetes (T2D), and T2D with CAD susceptibility, suggesting that these variants are strong candidates for the common soil hypothesis. Therefore, it is essential to analyze the relationship between ADIPOR1 variants and the susceptibility to CAD, T2D, and T2D with CAD in other populations. Materials and Methods: A case–control study was conducted which included three case cohorts [CAD (n = 316), T2D (n = 295), T2D with CAD (n = 302)], and a control cohort (n = 268) from a population in northeast China. Six ADIPOR1 single-nucleotide polymorphisms were genotyped by high-resolution melting and polymerase chain reaction–restriction fragment length polymorphism. Results: We confirmed that the shared variant, rs3737884*G, in ADIPOR1 is associated with CAD, T2D, and T2D with CAD (p-value range: 6.54E-6–1.82E-5, odds ratio [OR] range: 1.770–1.844) and that rs16850797*C is associated with T2D and T2D with CAD (p-value range: 0.001–0.001, OR range: 1.529–1.571). We also found that a novel shared variant, rs7514221*C, is associated with an increased susceptibility to CAD, T2D, and T2D with CAD (p-value range: 0.002–0.004, OR range: 1.194–2.382) in this population. Conclusions: ADPOR1 variants, rs3737884*G and rs7514221*C, may be shared risk factors associated with CAD, T2D, and T2D with CAD in a population of northeast China.

In bone tissue engineering, failure might take place in treating infected bone defects. Scaffolding materials with antibacterial function should be a potential solution for this problem. Herein, poly(L-lactide) (PLLA)–hydroxyapatite (HA) nanocomposites containing antibacterial silver nanoparticles (AgNPs) were prepared. In the preparation, surface coating of polydopamine (PDA) on HA nano-rods was a critical step to ensure both the homogeneous dispersion of HA nano-rods in the PLLA matrix and the successful loading of AgNPs onto HA nano-rods. With the total content of HA being fixed at 30 wt%, PLLA/HA nanocomposites containing different amounts of AgNPs (∼0.54 wt%, ∼0.27 wt% and ∼0.18 wt%) were prepared by mixing PDA-coated HA nano-rods (m-HA) with or without AgNPs at different ratios into PLLA. The resulting PLLA/HA/Ag nanocomposites demonstrated strong antibacterial activity against Escherichia coli at low content of AgNPs being incorporated, while they did not show significant cytotoxicity to bone mesenchymal stromal cells (BMSCs). In comparison with those cells cultured on pure PLLA film and tissue culture polystyrene, on the contrary, osteogenic differentiation of BMSCs was enhanced on PLLA/HA/Ag nanocomposite films benefiting from the HA component. The results suggested that PLLA/HA/Ag nanocomposites are anticipated to be good scaffolding materials for bone regeneration with dual functions of both antibacterial activity and osteocompatibility.

Mesoporous silica nanoparticles (MSNs) have been widely studied as drug carriers to get sustained release behaviors, however, their application in sustained release of metoprolol tartrate (MPT) is limited. The possible reason is due to MPT molecule being bulky, while normal type MSNs like MCM-41 and SBA-15 have pore sizes of only 3–6 nm. In this study, two MCF-26 type MSNs were prepared with pore size of 11 or 15 nm, and used to conduct MPT release in comparison with MCM-41 and SBA-15. Both molecular simulation and MPT release experiments were performed to identify the pore size effect on adsorption and diffusion (release) of MPT in these MSNs. Finally, a kind of pH-sensitive MPT drug delivery system was obtained by coating the chosen MCF-26@MPT with an enteric polymer, which might find promising application in treating morning hypertension attack by orally administrating the drug delivery system before bedtime.

Primary chylopericardium (CP) is a rare clinical condition in which chylous fluid containing high concentrations of triglyceride accumulates in the pericardial cavity. The present study reports a case of CP that was successfully treated by reconstruction surgery of thoracic duct. To improve the ability to diagnosis and treat this rare disease, the current study also systematically extracted 104 reported cases of primary or idiopathic CP from the past 60 years (January 1950 to December of 2015), and reviewed the clinical manifestation, etiology, diagnosis and treatment of these cases. The age at diagnosis varied between 6 weeks and 79 years with a mean age of 27.95±16.50 years. Asymptomatic patients accounted for 39.42% of cases, while the most common initial symptoms were dyspnea (44.23%) and coughing (10.58%). Jugular venous distention and distant heart sound was identified in 23 (22.12%) and 34 cases (32.69%), respectively. Cardiomegaly in X-ray scans was detected in the majority of patients (93.27%). In addition, lymphoscintigraphy and lymphangiography were helpful in identifying the source of chyle. Regarding the etiology, idiopathic cases accounted for 35.56% of the included cases in the present study. The most important cause of primary CP was abnormal connection or accumulation of lymph fluid in the pericardium (37.50%). Conservative therapy included low-fat or medium-chain triglyceride diet, as well as total parenteral nutrition. The majority of patients (71.2%) required surgery for definitive therapy, and thoracic duct ligation was the most preferred surgical procedure, performed in 44.23% of cases. Follow-up was reported in 64 cases, and all patients survived during the mean follow-up period of 12 months. Therefore, it is suggested that surgical management is the most successful treatment method and is associated with a favorable prognosis.

The aim of this study was to assess the prevalence of metabolic syndrome (MetS) in non-obese adults (body mass index (BMI) < 25 kg/m2) and the prevalence of obese adults (body mass index (BMI) ≥ 25 kg/m2) without MetS in Chinese Beijing urban subjects. A cross-sectional study was conducted and the subjects who came to the hospital to receive a health examination were enrolled randomly. Regardless of age stratification, men have a higher prevalence of MetS than women. Among the urban Beijing population, prevalence of metabolically obese but normal weight (MONW) is lower than metabolically healthy but obese (MHO) regardless of gender. Except for the underweight group, participants exhibit significant differences between MetS and non-MetS subgroups in all tested variables in normal weight and overweight groups, whereas MONW and MHO participants exhibit significant differences in all variables except for creatinine (CR), aspartate aminotransferase (AST), uric acid (UAC) and high-density lipoprotein cholesterol (HDL-C). Women tend to have a higher MONW prevalence but lower MHO prevalence than men. Accordingly, MetS happens more frequently among those 40-59 yr. Besides, sex, age, WC, SBP, DBP, ALT, FG, UAC, TG, HDL-C and LDL-C are risk factors for MetS after multivariate adjustment. In conclusion, the prevalence of MONW is lower than MHO regardless of gender. Women tend to have a higher MONW prevalence but lower MHO prevalence than men.

In addition to providing maneuverability, electrospun nanofibrous meshes can make excellent supports for constructing flexible cell sheets to regulate cell behavior by nanofiber features. With the target of bone regeneration, herein composite nanofibers with two different fiber arrangements (nestlike, random) were electrospun from a blend solution containing poly(l-lactide) (PLLA) and gelatin (1:1 in weight ratio). Unlike the non-woven morphology in a random nanofibrous mesh, PLLA/gelatin composite nanofibers in the nestlike nanofibrous mesh displayed both non-woven and parallel morphologies. Both kinds of nanofibrous mesh were ∼50 μm thick as-prepared, and shrank to ∼30 μm after seeding with bone mesenchymal stromal cells (BMSCs). After 7 days of in vitro culture, cell sheets could form on both meshes (CSM) and on the culture plate. It was found that application of nanofibrous mesh promoted the osteogenic differentiation of BMSC sheets compared with the control. The nestlike mesh displayed slight superiority over the random mesh in enhancing osteogenic differentiation, but their different fiber arrangements did not cause much difference in cell proliferation. Three-dimensional multi-layered CSM constructs were built by stacking four mono-layered CSMs together. The CSM constructs (based on a nestlike or random nanofibrous mesh) were incubated in vitro for 3 days before being implanted into rat cranial defects. In comparison with the control group, there was significant formation of new calcified bone in both CSM construct-filled groups at 12 weeks' post-operation. The nestlike group showed slightly better bone healing (based on both qualitative and quantitative analysis) than the random group, while showing insignificant differences. We showed that the concept of using a three-dimensional multi-layered CSM construct in enhancing bone regeneration was feasible. Future studies should take more nanofiber features (e.g. bioactive components) into account to further enhance osteogenesis.

Biological functions of hybridized carbon nanofibers (CNFs) depend closely on the incorporated bioactive components. For hybridized CNFs containing bioactive glass (BG) nanoparticles (CNF/BG), chemical compositions of BG nanoparticles might have decisive effects on their cell affinity and osteocompatibility. Herein, three hybridized CNF/BGs were produced by incorporating 68S-type BG nanoparticles with different Ca/P molar ratios (1.0, 1.67 or 2.5) into CNFs via a sol–gel/electrospinning and carbonization method. Structural evolution of these hybridized CNF/BGs was studied in relation to their Ca/P molar ratios. Crystalline wollastonite was found to be the dominant phase at a high feeding Ca/P molar ratio (i.e. 2.5), but weak crystallized hydroxyapatite was the main phase at the low feeding Ca/P molar ratio (i.e. 1.0). These findings were correlated to the biological functions of the resulted CNF/BG hybrids including apatite formation ability in simulated body fluid and osteoblast behaviors in in vitro culture. All the CNF/BG hybrids displayed a strong affinity for inducing apatite deposition, showing insignificant difference after the initial nucleation stage, while they behaved differently in promoting the proliferation and osteogenic differentiation of osteoblasts. The fastest proliferation rate and the highest expression of alkaline phosphatase activity was found on the CNF/BG (Ca/P = 1.0). The results suggested a feasible way to upregulate osteoblast behaviors is by changing the feeding Ca/P molar ratios in the preparation of CNF/BG hybrids for potential bone repairing applications.

Perovskite-type BiFeO3nanofibers with wave nodes-like morphology were prepared by electrospinning. The nanofibers show a highly enhanced visible-light-active photocatalytic property. The results also showed that the diameter could affect the band gap and photocatalytic performances of nanofibers. Additionally, weak ferromagnetic behaviors can be observed at room temperature, which should be correlated to the size-confinement effect on the magnetic ordering of BiFeO3structure.

To define the pathological changes of coronary artery and compare the clinical diagnosis and pathological diagnosis differences in elderly patients aged 80 and over.A total of 909 autopsy cases aged 60-100 years in our hospital from April 1st 1969 to October 31th 2013 were analyzed. The prevalence and pathological features of coronary artery disease (CAD) in cases aged 80 years and over were compared with those aged 60-79 years old. The misdiagnosis and missed diagnosis rate were calculated.The prevalence of CAD by autopsy (63.8% (289/453) vs. 39.9% (182/456), P0.01), old myocardial infarction (OMI) by autopsy (63.0% (182/289) vs. 51.6% (94/182), P0.05) and chronic myocardial ischemia by autopsy (22.5% (65/289) vs. 7.1% (13/182), P0.01) were significantly higher while the prevalence of acute myocardial infarction (AMI) by autopsy was significantly lower (22.1% (64/289) vs. 42.9% (78/182), P0.01) in aged 80 and over group compared to 60-79 years old group. The misdiagnosis rate of CAD was 65.2% (107/164), the missed diagnosis rate of OMI was 62.1% (113/182) and the missed diagnosis rate of AMI was 37.5% (24/64) in the aged 80 and over group.The prevalence of CAD and misdiagnosis and missed diagnosis rate are high in dead inpatients aged 80 years and over. OMI is more common but often missed in this group. Thus, the diagnosis and evaluation of CAD should be enhanced in this patient group.

This paper presents a method to investigate the characteristics of a high-speed motorized spindle system. The geometric quality of high-precision parts is highly dependent on the dynamic performance of the entire machining system, which is determined by the interrelated dynamics of machine tool mechanical structure and cutting process. This performance is of great importance in advanced, high-precision manufacturing processes. The state-of-the-art in machine tool main spindle units is focus on motorized spindle units for high-speed and high performance cutting. This paper taking the high-speed milling motorized spindle of CX8075 produced by Anyang Xinsheng Machine Tool Co. Ltd. as an example, a finite element model of the high-speed motorized spindle is derived and presented. The model takes into account bearing support contact interface, which is established by spring-damper element COMBIN 14. Furthermore, the static analysis, modal analysis, harmonic response analysis and thermal analysis were done by means of ANSYS commercial software. The results show that the maximum rotating speed of the motorized spindle is far smaller than the natural resonance region speed, and the static stiffness of the spindle can meet the requirements of design. The static and dynamic characteristics of the motorized spindle accord with the requirements of high-speed machining. The thermal deformation of spindle is 6.56µm, it is too small to affect the precision of the spindle. The results illustrate the rationality of the spindle structural design.

With the ever-growing popularity of smartphones, new services are emerging where the local and positioning as- pects becomes more important. Additionally, new types of traffic, such as vehicle-to-vehicle communications are being developed. In order to address these new trends, release-12 of LTE has started to evaluate, and possibly standardize, solutions for de- vice-to-device (D2D) communication. This provides the founda- tions for the deployment of a D2D overlay. However, this should be viewed as a first step, and future LTE releases should encom- pass more advanced D2D communication techniques and archi- tectures. In this paper, after reviewing the standardization progress for LTE in release-12, several possible improvements are examined for future releases both D2D discovery and com- munication. It is shown that the future D2D architecture should exploit the network when possible in order to provide an im- proved user experience and satisfy the need for more local ser- vices.

Ni1−xFexOnanofibers with different Fe doping concentration have been synthesized by electrospinning method. An analysis of the phase composition and microstructure shows that Fe doping has no influence on the crystal structure and morphology of NiO nanofibers, which reveals that the doped Fe ions have been incorporated into the NiO host lattice. Pure NiO without Fe doping is antiferromagnetic, yet all the Fe-doped NiO nanofiber samples show obvious room-temperature ferromagnetic properties. The saturation magnetization of the nanofibers can be enhanced with increasing Fe doping concentration, which can be ascribed to the double exchange mechanism through the doped Fe ions and free charge carriers. In addition, it was found that the diameter of nanofibers has significant impact on the ferromagnetic properties, which was discussed in detail.

A numerical method is developed to solve the problem of designing a noncircular gear derived from a numerical angle relationship. The new numerical method is suitable not only for closed and continuous gears, but also for unclosed and discontiguous gears. A set of numerical calculation methods to decompose the gear pair into an equivalent fixed gear train with two same gear pairs is proposed in order to improve the transmission quality of the gear pair with a large varied range of pitch curve polar radii. Two examples of decomposing a gear pair are established derived from the numerical rotation angle relationships. This method is validated through the comparison between design results and theoretical data.

Air drilling has many advantages over mud drilling in increasing penetration rate, decreasing formation damage, eliminating lost circulation, reducing pressure differential sticking and so on. Hole cleaning and pipe erosion failure are the two key problems for air drilling. Hence proper injecting parameters should not only meet the requirement of carrying cuttings, but also avoid the erosion of drillpipe. For example, if the standpipe pressure was much larger, high-speed air flow with cuttings would cause the erosion of drillpipe and destroy its internal coating, which is the main reason of shorting service time of drillpipe. Other parameters such as drillpipe rotational speed, borehole deviation, eccentricity, cutting size and cutting density also affect the cuttings transportation and pipe erosion. Previous published papers are limited to physical model dimensions and operating parameters, or no exact calculation results due to too many assumptions.In this paper, a model of gas-solid two-phase flow was built and a new approach to determine the injecting parameters was introduced. Based on the computational fluid dynamics and aerodynamics theory, the flow properties in 311.5mm wellbore, 1500m long, with 127mm drillpipe had been simulated with variable parameters. Then the distributions of pressure, velocity and cuttings volumetric concentration were obtained in drillstring and annulus. By analyzing multi-group calculation results, injecting parameters were optimized to meet the needs of the drilling job. Calculation results coincided well with the actual field data, and had been used to guide air drilling in Da-Wan 3 well, Lao-Jun 1 well, and Qing-Xi 1 well for Chuanqing Drilling and Exploration Corp.

A new master-slave motion control system based on air bearing is presented in this paper. By using two kinds of actuators —— a linear motor and a Lorentz motor, a new type dual-stage has been designed. Both motors are guided and suspended respectively by air bearings which float on a granite surface for frictionless movement. Making full use of the advantages of the two actuators ——the long stroke of linear motor, the high accuracy of Lorentz motor, and the high response of both actuators, the stage completes positioning in one phase and assures both positioning accuracy and moving speed in long stroke. There is no friction force in both master and slave systems. Yet there is reaction force between them. That force is detrimental to positioning, even resulting in collision between the two motors. By introducing additional feedforward control to line motor control system, the problem is solved preferably.

The Intelligent Transportation System (ITS) is the application of communications technology, computer, and electronic to vehicles, roadways and users, so as to increase safety, reduce congestion, and enhance mobility. All the parts of ITS are linked and exchange real-time information each other through communication system. With the development of mobile communications technique, it also brings new applications in ITS. These new applications main include transport information service, Electronic Payment methods, location and navigation, on board equipment, emergency management etc. Through the use of technology in transportation operations, useful information for the traveler is becoming available in "real-time".

The δ18O and δD values for meteoric water samples collected from eastern Xizang and western Sichuan and Guizhou show a linear correlation and can be described by the following equation: δD = 8.22δ18O + 18.99. The isotopic compositions of these meteoric waters also exhibit obvious altitude effect. There have been found negative correlations between δ18O, δD and the elevation, which are characterized by −δO‰ = 0.0031H(m) + 6.19 and −δD‰ = 0.026H(m) + 30.20. The average δ18O and δD values for meteoric waters in the areas with an altitude of more than 4,000m above sea level are equal to -18.70 and -137.8‰, respectively. It is evident that the δ18O and δD values for plateau lake waters depend on their water supply. The δ18O and δD values for the water in lakes where the evaporation rate is greater than the recharge rate, are approximately three or four times higher than those of supply water, averaging -5.74 and -60.5‰, respectively. The oxygen and hydrogen isotopic compositions of geothermal waters as compared with those of local meteoric waters in adjacent areas show that the latter seems to be the main water-supply source.