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The release of several environmental pollutants poses a potential threat to the several ecosystems and humans. Reproductive toxicity represents one of the most significant toxic effects of environmental contaminants. It is necessary to assess reproductive toxicity and the mechanisms underlying environmental toxicity in organisms. Because of its unique features in toxicology research, Caenorhabditis elegans is an important animal model used for the toxicity assessment of environmental contaminants. In this review, we introduce the reproductive toxicity and mechanisms underlying the actions of environmental contaminants, including heavy metals, organic pollutants, particulate matter, microplastics, nanomaterials, and irradiation. Moreover, we have put forth some perspectives about toxicity assessments, transgenerational toxicity, and toxicological mechanisms of environmental contaminants in the future.

Abstract Background Chinese youth have become more sexually active over the years, yet their behaviours of contraceptive use are influenced by socioeconomic and lifestyle factors. This study aimed to investigate the socioeconomic and lifestyle determinants of contraceptive use among Chinese college students, and to investigate quantitatively their reasons for choosing different contraceptive methods. Methods The study used the data from a cross-sectional survey, which was conducted in 2015 among 17,517 students from 130 colleges and professional schools in mainland China. Chi-square tests were performed to test the differences in the awareness and uses of contraceptives between male and female students. Multivariable logistic regression models were used to analyse the associations between socioeconomic and lifestyle factors and contraceptive uses. Results Condoms (95%), oral contraceptives (91%) and emergency contraceptives (71%) were the most commonly known contraceptive methods among the sample of Chinese youth that were surveyed. Among male participants, high monthly expenditure (OR = 1.37, 95%CI: 1.07–1.75), light alcohol consumption (OR = 1.47, 95%CI: 1.03–2.11), and high sexual knowledge (OR = 1.96, 95%CI: 1.57–2.45) were positively associated with contraceptive uses, while tobacco use (OR = 0.47, 95%CI: 0.23–0.95) showed a negative association with contraceptive uses. Among female students, suburban residency (OR = 1.38, 95%CI: 1.03–1.83), high level of parental education (OR = 1.96, 95%CI: 1.19–3.22), moderate alcohol consumption (OR = 2.66, 95%CI: 1.05–6.77), and high sexual knowledge (OR = 1.50, 95%CI: 1.18–1.91) were positively associated with contraceptive uses, while tobacco use (OR = 0.60, 95%CI: 0.36–0.99) showed a negative association. Conclusions A series of socioeconomic and lifestyle factors were associated with contraceptive choices among Chinese college students. Targeted sexual education programs are in demand to improve the awareness and the use of contraceptives in this population.

Abstract Background Breastfeeding rates remain low in China and some mothers stop breastfeeding shortly after returning to work. Our study aimed to investigate the association between breastfeeding practices of working mothers and their employment status (formal versus informal) and occupational fields (agriculture related, industry related, and business and white collar). We also identified key work-related factors that influence breastfeeding practices in Chinese working mothers. Methods This is a mixed-method research consisted of two components. We conducted a cross-sectional study of 10,408 breastfeeding mothers with children under 12 months old from 12 regions in China from July 2017 to January 2018. Multiple logistic regression was used to calculate adjusted odds ratios (AdjORs) and 95% confidence intervals (CIs) for breastfeeding practices. For the qualitative component, semi-structured interviews were conducted with 84 breastfeeding mothers in the study areas from July to December 2017, Content analysis was used for the qualitative component. Results Agriculture related occupations were positively associated with early initiation of breastfeeding (AdjOR 1.32, 95% CI 1.15, 1.51), current breastfeeding (AdjOR 1.76, 95% CI 1.41, 2.20), ever breastfed (AdjOR 1.69, 95% CI 1.09, 2.62), exclusive breastfeeding (AdjOR 1.30, 95% CI: 1.04, 1.62), and predominant breastfeeding (AdjOR 1.72, 95% CI 1.44, 2.05). Business and white collar occupations were positively associated with early initiation (AdjOR1.38, 95% CI 1.23, 1.56) and ever breastfed (AdjOR 1.64, 95% CI 1.12, 2.39), and inversely associated with predominant breastfeeding (AdjOR 0.81, 95% CI 0.68, 0.95). For industry related and business and white collar occupations, informal employment was negatively related to current breastfeeding. In qualitative analysis, four main themes were developed to identify key work-related factors that influence breastfeeding practices: 1) employment benefits; 2) commute time; 3) workplace environment; 4) labor intensity. Mothers who experienced difficulties in one or more of the above would choose to lower breastfeeding frequency or stop breastfeeding. Conclusions Having flexible work schedules and proximity of workplace to home can assist continuance of breastfeeding. Policies promoting supportive breastfeeding environment at work ought to be implemented. Additionally, informally employed mothers require more attention due to limited legal protection.

Abstract Background The current situation of breastfeeding in China has been discussed in many articles, and a declining trend of breastfeeding duration has been confirmed. The associations between various socioeconomic, reproductive factors and breastfeeding duration have been discussed as well. However, there remains a lack of evidence on breastfeeding duration amongst different age groups. Methods Data was extracted from the baseline of a large cohort study: a sample of 300,000 adult women born in the 1930s’ through 1970s’ from 10 geographically distinct regions was obtained. The breastfeeding duration was assumed by breastfeeding duration of the first child. Different age groups were categorized by 10-year age groups, and they were born in 1930–1938, 1939–1948, 1949–1958, 1959–1968, and 1969–1974. Multivariable linear regression was used to evaluate the associations between breastfeeding duration and sociodemographic, and reproductive factors (i.e.: different age groups, education, household size, use of oral contraceptive pills, age at menarche, and age at first birth). Results The mean breastfeeding duration (Standard Deviation) of women born in 1930–1938, 1939–1948, 1949–1958, 1959–1968, and 1969–1974 were 15.4 (9.2), 14.8 (8.2), 14.7 (8.9), 12.8 (7.2), 13.1 (7.2) months, respectively. Younger age groups, higher levels of education, and use of oral contraceptive pills were negatively associated with breastfeeding duration. In particular, the negative association with higher levels of education (for urban regions: βmiddle school = − 1.3, βhigh school & above = − 1.6; for rural regions: βmiddle school = − 0.6, βhigh school & above = − 1.2; all p

Abstract Olefin/paraffin separations are among the most energy-intensive processes in the petrochemical industry, with ethylene being the most widely consumed chemical feedstock. Adsorptive separation utilizing molecular sieving adsorbents can optimize energy efficiency, whereas the size-exclusive mechanism alone cannot achieve multiple olefin/paraffin sieving in a single adsorbent. Herein, an unprecedented sieving adsorbent, BFFOUR-Cu-dpds (BFFOUR = BF4 -, dpds = 4,4’-bipyridinedisulfide), is reported for simultaneous sieving of C2-C4 olefins from their corresponding paraffins. The interlayer spaces can be selectively opened through stronger guest-host interactions induced by unsaturated C = C bonds in olefins, as opposed to saturated paraffins. In equimolar six-component breakthrough experiments (C2H4/C2H6/C3H6/C3H8/n-C4H8/n-C4H10), BFFOUR-Cu-dpds can simultaneously divide olefins from paraffins in the first column, while high-purity ethylene ( > 99.99%) can be directly obtained through the subsequent column using granular porous carbons. Moreover, gas-loaded single-crystal analysis, in-situ infrared spectroscopy measurements, and computational simulations demonstrate the accommodation patterns, interaction bonds, and energy pathways for olefin/paraffin separations.

BACKGROUND:Accumulating evidence has demonstrated that cyclooxygenase-2 (COX-2) is involved in head and neck cancers, especially in nasopharyngeal carcinoma (NPC). However, the association between COX-2 expression and lymph node metastasis in NPC remains uncertain. This systematic review and meta-analysis meta-analysis investigated the relationship between COX-2 expression and lymph node metastasis and other signs of disease progression in NPC. METHODS:Previously published studies assessing COX-2 expression and lymph node metastasis in NPC were identified in four English databases and three Chinese ones (Pubmed, Embase, Cochrane Database of Systematic Reviews, Web of Science, China National Knowledge Infrastructure, Wanfang, Vip Journal Integration Platform) up to November 2016. Quality of all eligible studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Pooled odds ratios (OR) and their 95% confidence intervals (95%CI) were calculated with fixed-effects or random-effects model to evaluate the effects of COX-2 expression on lymph node metastasis. RESULTS:A total of 27 studies with 1797 NPC patients met the inclusion criteria. The expression of COX-2 was significantly higher in patients with nasopharyngeal carcinoma than those without the carcinoma, with a combined OR of 21.17 (95%CI = 15.02-29.85, I2 = 35.1%, Pheterogeneity = 0.070). A statistically significant association between COX-2 expression and lymph node metastasis in NPC patients, with an OR of 4.44 (95%CI = 3.46-5.70, I2 = 38.3%, Pheterogeneity = 0.024), and with other indicators of disease progression. Subgroup analyses based on COX-2 assay and staging criteria of TNM showed no significant heterogeneity. CONCLUSIONS:The results suggest that expression of COX-2 is associated with lymph node metastasis and disease progression in NPC, indicating a potential role in evaluation of prognosis and in treatment decisions. COX-2 inhibitors have potential in the treatment of NPC that should be further investigated.

Colorectal cancer (CRC) is the third most prevalent cancer type and the third leading cause of cancer-related deaths worldwide, it is urgently needed to discover a new marker for the progress of CRC. Many long noncoding RNAs (lncRNAs) have been reported to be abnormally expressed in CRC, and may be feasible as effective biomarkers and prognostic factors. The aim of this study was to identify the prognostic value of various lncRNAs in CRC.Pubmed, Web of Science, Embase and Cochrane Library were searched for potentially related studies. A total of 34 eligible studies including 30 on overall survival (OS), 7 on disease-free survival (DFS), 1 on relapse-free survival (RFS), 2 on disease-specific survival (DSS) and 29 on clinicopathological features were qualified from the databases.The results showed that the expression levels of lncRNAs were significantly associated with poor OS (hazard ratio (HR) = 2.08, 95% confidence interval (CI) = 1.68-2.57, P