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The collapse mechanism of a circular unlined tunnel roof subjected to the pore water pressure under plane strain conditions is investigated in this article. First, the model of calculating the function expression of the detaching surface for the collapsing block is formed in the framework of the upper bound theorem of limit analysis and the extremum principle. The analytical solution of the pore water pressure around the tunnel in a two-dimensional steady seepage field is employed in the equations of the model. Then, the numerical approach based on the Runge–Kutta algorithm and traversal search method is proposed to solve the complex equations. The obtained expression of the detaching surface for the collapsing block provides the shape of the collapsing block and a theoretical basis for designing the support force for tunnels. The proposed limit analysis method and numerical approach are verified by comparing with existing theoretical solutions and the numerical simulation result, and they are suitable for deep, shallow tunnels and layered strata. Moreover, the effects of different parameters on the collapse mechanism are investigated, and qualitative results are provided.

Background: Rheumatoid arthritis (RA) is an autoimmune disorder that affects the small joints of the body. It is one of the leading causes of chronic morbidity in high–income countries, but little is known about the burden of this disease in low– and middle–income countries (LMIC). Methods: The aim of this study was to estimate the prevalence of RA in six of the World Health Organization's (WHO) regions that harbour LMIC by identifying all relevant studies in those regions. To accomplish this aim various bibliographic databases were searched: PubMed, EMBASE, Global Health, LILACS and the Chinese databases CNKI and WanFang. Studies were selected based on pre–defined inclusion criteria, including a definition of RA based on the 1987 revision of the American College of Rheumatology (ACR) definition. Results: Meta–estimates of regional RA prevalence rates for countries of low or middle income were 0.40% (95% CI: 0.23–0.57%) for Southeast Asian, 0.37% (95% CI: 0.23–0.51%) for Eastern Mediterranean, 0.62% (95% CI: 0.47–0.77%) for European, 1.25% (95% CI: 0.64–1.86%) for American and 0.42% (95% CI: 0.30–0.53%) for Western Pacific regions. A formal meta–analysis could not be performed for the sub–Saharan African region due to limited data. Male prevalence of RA in LMIC was 0.16% (95% CI: 0.11–0.20%) while the prevalence in women reached 0.75% (95% CI: 0.60–0.90%). This difference between males and females was statistically signifcant (P

Colon cancer is currently a highly prevalent cancer with a high mortality rate worldwide. Modern medical technology provides a range of treatments for colon cancer through different means, and research on the modulating adjuvant treatment of colon cancer with Chinese medicine is currently undergoing continuous theoretical and practical exploration to find highly effective herbal remedies to modulate, alleviate or treat the disease. The present study reviews different aspects of colon cancer in relation to different factors and the modulating adjuvant treatment of colon cancer with Chinese medicine. [ABSTRACT FROM AUTHOR]

Tetrodotoxin is a marine biotoxin with high acute toxicity. The levels in cooked seafood will help us to assess its intake in humans and may help assess the risk of toxicity. However, heavy matrices hinder the direct quantitation of tetrodotoxin. A quantitative method of measuring tetrodotoxin in cooked seafood using liquid chromatography with triple quadrupole mass spectrometry was established in this study. Tetrodotoxin was extracted from the sample matrix using 2% formic acid in methanol and cleaned using a cation exchange cartridge. The cleanup conditions were optimized. The matrix effects were determined using the postextraction spiking method and by comparing the slope of the linear regression equation in sample matrix to that in solvent. The limit of detection in the sample matrix was 5 μg/kg and the limit of quantification was 10 μg/kg. The mean recoveries at three spiking levels were 66.9-89.2% with relative standard deviations of 5.0-10.8% ( n = 6) in five different matrices. Tetrodotoxin was found at concentrations of 26.1-2462 μg/kg in nine of 83 cooked seafoods tested in this study. Eight analogs of Tetrodotoxin were detected in the samples studied. [ABSTRACT FROM AUTHOR]

Objective To assess the net health effect caused by the consumption of specific marine species based on Benefit-Risk Analysis for Foods (BRAFO)-tiered approach. Methods Twenty species were collected from the Zhoushan Archipelago, China. Concentrations of n-3 long-chain polyunsaturated fatty acids, methyl mercury (MeHg), and dioxin-like compounds (DLCs) in the samples were analyzed for benefit risk assessment based on BRAFO-tiered approach. Results Based on the BRAFO-tiered approach, reference scenario (no intake) and alternative scenario (intake of specific species of 200 g/week) were determined. The exposure to MeHg/DLCs via alternative scenario of all studied species did not exceed provisional tolerable weekly/monthly intake. However, the adult population with high DLCs exposure in China would significantly exceed the upper limit of DLCs via an additional alternative scenario of some species such as Auxis thazard . The results of deterministic computation showed that alternative scenario of all studied species generated clear net beneficial effects on death prevention and child IQ gain. Conclusions The alternative scenario of all studied species could be recommended to population with average DLCs exposure, and the reference scenario of species with relatively high DLCs concentration could be recommended to population exposed to high DLCs. [ABSTRACT FROM AUTHOR]

A novel approach for the direct synthesis of a 1,2,4-triazine core starting from eight azo conjugated aromatic compounds, 5-azo-(1,2,4-triazolyl) salicylic acid, 5-azo-(3-methyl-1,2,4-triazolyl) salicylic acid, 5-azo-(3-carboxyl-1,2,4-triazolyl) salicylic acid, 5-azo-(1,2-pyrazolyl) salicylic acid, 4-azo-(1,2,4-triazolyl) phenol, 4-azo-(3-carboxyl-1,2,4-triazolyl) phenol, 4-azo-(1,2-pyrazolyl) phenol, and 5-azo-(1,2,4-triazolyl) acetylsalicylic acid, via transition or lanthanide metal catalyzed intramolecular C–H/N–H functionalization and C–N bond formation has been developed under one-step hydrothermal synthetic conditions. [ABSTRACT FROM AUTHOR]

Background Rheumatoid arthritis (RA) is an autoimmune disorder that affects the small joints of the body. It is one of the leading causes of chronic morbidity in high-income countries, but little is known about the burden of this disease in low- and middle-income countries (LMIC). Methods The aim of this study was to estimate the prevalence of RA in six of the World Health Organization's (WHO) regions that harbour LMIC by identifying all relevant studies in those regions. To accomplish this aim various bibliographic databases were searched: PubMed, EMBASE, Global Health, LILACS and the Chinese databases CNKI and WanFang. Studies were selected based on pre-defined inclusion criteria, including a definition of RA based on the 1987 revision of the American College of Rheumatology (ACR) definition. Results Meta-estimates of regional RA prevalence rates for countries of low or middle income were 0.40% (95% CI: 0.23-0.57%) for Southeast Asian, 0.37% (95% CI: 0.23-0.51%) for Eastern Mediterranean, 0.62% (95% CI: 0.47-0.77%) for European, 1.25% (95% CI: 0.64-1.86%) for American and 0.42% (95% CI: 0.30-0.53%) for Western Pacific regions. A formal meta-analysis could not be performed for the sub-Saharan African region due to limited data. Male prevalence of RA in LMIC was 0.16% (95% CI: 0.11-0.20%) while the prevalence in women reached 0.75% (95% CI: 0.60-0.90%). This difference between males and females was statistically significant (P < 0.0001). The prevalence of RA did not differ significantly between urban and rural settings (P = 0.353). These prevalence estimates represent 2.60 (95% CI: 1.85-3.34%) million male sufferers and 12.21 (95% CI: 9.78-14.67%) million female sufferers in LMIC in the year 2000, and 3.16 (95% CI: 2.25-4.05%) million affected males and 14.87 (95% CI: 11.91-17.86%) million affected females in LMIC in the year 2010. Conclusion Given that majority of the world's population resides in LMIC, the number of affected people is substantial, with a projection to increase in the coming years. Therefore, policy makers and health-care providers need to plan to address a significant disease burden both socially and economically. [ABSTRACT FROM AUTHOR]

Highlights: [•] OCP accumulation was measured in seafoods from four counties of Zhejiang Province. [•] OCP concentrations in 13 types of seafoods ranged from 258.3 to 3459.6ngg−1 (lw). [•] HCHs and DDTs were the most abundant OCPs in seafoods from the tested environments. [•] Total OCP content in seafoods varied regionally and was highest in Shengsi and Putuo. [•] OCPs in seafoods of Shengsi may be from dicofol products used in Yangtze Estuary. [ABSTRACT FROM AUTHOR]

Arsenic (As) in the aquatic environment is a considerable environmental issue, previous studies have reported the toxic effects of low concentrations (≤ 150 μg/L) of As on fish. However, limited information is available regarding the impact of low levels of As on apoptosis. To evaluate this, zebrafish embryos were exposed to different concentrations (0, 25, 50, 75, and 150 μg/L) of As (arsenite [AsIII] and arsenate [AsV]) for 120 h. Our results indicated that low concentrations of AsIII exposure significantly inhibited the survival of zebrafish larvae, and significantly increased the transcription of Caspase-9 and Caspase-3 , the ratio of Bax/Bcl-2 transcription, and protein levels of Caspase-3. In contrast, AsV decreased the ratios of Bax/Bcl-2 transcription and protein levels, as well as protein levels of Caspase-3. Our data demonstrated that AsIII and AsV exert different toxic effects, AsIII induced apoptosis via the mitochondrial pathway and the extrinsic pathway, while AsV induced apoptosis only via the mitochondrial pathway. • Our study focused on the impact of low concentrations of arsenic on the apoptotic toxicity and manner of zebrafish larvae. • Low concentration of arsenite decreased the survival rate of zebrafish larvae, while low concentration arsenate had no effect on it. • Low concentration of arsenite can induce apoptosis of zebrafish larvae stage via the mitochondrial pathway and the extrinsic pathway. • Low concentration of arsenate can induce apoptosis of zebrafish larvae stage via the mitochondrial pathway. [ABSTRACT FROM AUTHOR]

Background: Infectious causes of childhood deaths in the world have decreased substantially in the 21st century. This trend has exposed accidental deaths as an increasingly important future challenge. Presently, little is known about the cause structure of accidental childhood deaths in low– and middle–income country (LMIC) settings. In this paper, we aim to establish cause structure for accidental deaths in children aged 0–4 years in China in the year 2010. Methods: In this paper, we explored the database of 208 multi–cause child mortality studies in Chinese that formed a basis for the first published estimate of the causes of child deaths in China (for the year 2008). Only five of those studies identified specific causes of accidental deaths. Because of this, we searched the Chinese medical literature databases CNKI and WanFang for single–cause mortality studies that were focused on accidental deaths. We identified 71 further studies that provided specific causes for accidental deaths. We used epidemiological modeling to estimate the number of accidental child deaths in China in 2010 and to assign those deaths to specific causes. Results: In 2010, we estimated 314 581 deaths in children 0–4 years in China, of which 31 633 (10.1%) were accidental. Accidental deaths contributed 7240 (4.0%) of all deaths in neonatal period, 8838 (10.5%) among all post–neonatal infant deaths, and 15 554 (31.7%) among children with 1–4 years of age. Among four tested models, the most predictive was used to establish the likely cause structure of accidental deaths in China. We estimated that asphyxia caused 9490 (95% confidence interval (CI) 8224–11 072), drowning 5694 (95% CI 5061–6327), traffic accidents 3796 (95% CI 3163–4745), poisoning 3163 (95% CI 2531–3796) and falls 2531 (95% CI 2214–3163) deaths. Based on medians from a few rare studies, we also predict 633 (95% CI 316–1265) deaths to be due to burns and 316 (95% CI 0–633) due to falling objects. Together, these 7 causes explain more than 80% of all accidental deaths when modeling is primarily used, and more than 95% when the analysis is based purely on medians from the 76 available studies. Conclusions: Reduction in global child mortality is a leading political priority and accidental deaths will soon emerge as one of the main challenges. In this paper we provided a detailed breakdown of causes of these deaths in a large middle–income country. We noted that, wherever the share of accidental deaths among all child deaths is increased, drowning is more likely to be the leading cause; asphyxia seems to be equally important in all contexts, while traffic accidents, poisoning and falls are relatively more important in contexts where the overall share of accidents to all child deaths is low.

Antibiotic resistance genes (ARGs) are ubiquitous in the environment, with previous studies mainly focusing on the terrestrial ecosystem, which is prone to higher antibiotic application. However, the characteristics, distribution pattern, and driving factors of soil ARGs at the macro scale are still unclear. In this study, the soil ARGs, antibiotics, mobile genetic elements (MGEs), soil properties, toxic metals, polycyclic aromatic hydrocarbons (PAHs), and bacterial community in the Taipu River Basin were analyzed to investigate the distribution and dissemination of ARGs at a watershed scale. The results revealed that ARGs were widespread in the soils along the Taipu River, and that ARG profiles varied greatly with different types of land use, but showed regional similarities. The characteristics were mainly determined by antibiotic input and the ARG transmission mediated by MGEs. The order of the contribution of environmental factors to ARG distribution was toxic metals > PAHs > soil properties. Toxic metal pollution was coupled with ARGs through MGE mediation, while PAHs and soil properties were most likely to affect the ARG distribution by shifting the bacterial community. The microbial–ecological relationship changed significantly with the enrichment of ARGs, and its impact may extend to the watershed scale. Transposon IS1247 can be used as an indicator of the ARGs impact on the microbial ecological relationship in the soils of the Taipu River Basin. [ABSTRACT FROM AUTHOR]

In this paper, the effect of skipjack (Katsuwonus pelamis) enzymatic peptide (SEP), which was prepared and purified from a byproduct of skipjack, on inflammation, ulcerative colitis and the regulation of intestinal flora was studied in a mouse ulcerative colitis model and a transgenic zebrafish inflammation model. The aggregation of transgenic granulocyte neutrophils in zebrafish from a normal environment and from a sterile environment was calculated, and the anti-inflammatory activity of SEP was evaluated. To evaluate the anti-ulcerative colitis activity of SEP, DSS-induced colitis mice were given SEP, salicylazosulfapyridine (SASP), or SASP + SEP. Then, the concentrations of IL-6, IL-10 and TNF-α in the serum were detected, the HE-stained colon tissue was examined by microscopy the species composition and abundance distribution of the intestinal flora was analyzed. The results showed that 500 μg/mL SEP treatment significantly alleviated neutrophil granulocyte aggregation in the zebrafish inflammation model; Diarrhea, hematochezia and body weight loss were alleviated to a certain extent in mice gavaged with SEP and SASP, and the combination of SASP with SEP was the most effective in mice. The damage to villi in the intestine was completely repaired, and the levels of IL-6, IL-10 and TNF-α, which are associated with inflammation, were all reduced. In addition, the proportion of intestinal probiotics or harmless bacteria increased, while that of pathogenic bacteria decreased, and the effect of the combined treatment was the most pronounced. These results show that SEP could relieve inflammation, cure ulcerative colitis, regulate intestinal flora and enhance the therapeutic effect of the clinical drug SASP. This study provides a theoretical basis for the development of SEP as an anti-inflammatory adjuvant therapy and intestinal flora regulator. [ABSTRACT FROM AUTHOR]