Maternal residential exposure to solvents from industrial sources during pregnancy and childhood cancer risk in California.

BACKGROUND: Maternal solvent exposure has been suspected to increase offspring cancer risk. The study aimed to evaluate the associations between maternal residential exposure to solvents from industrial pollution during pregnancy and childhood cancer. METHODS: The present study included 15,744 cancer cases (aged 0-19 years at diagnosis) identified from California Cancer Registry and 283,141 controls randomly selected from California Birth Registry (20:1 frequency-matched by birth year: 1998-2016). We examined industrial releases of tetrachloroethylene and 1,1,1-trichloroethane within 3 km of the birth address, while we used a 5 km buffer for carbon disulfide. We calculated the total exposure from all linked Toxic Release Inventory sites during each index pregnancy and assigned "ever/never" and "high/low exposed/unexposed" exposure, using median values. We performed quadratic decay models to estimate cancer risks associated with maternal solvent exposure in pregnancy. RESULTS: 1,1,1-Trichloroethane was associated with rhabdomyosarcoma (adjusted Odds Ratio (aOR): 1.96; 95% Confidence Interval (CI): 1.16, 3.32) in the "ever exposed" group. Ever exposure to carbon disulfide was associated with increased risks of medulloblastoma (OR = 1.85, 95% CI 1.01, 3.40) and ependymoma (OR = 1.63, 95% CI 0.97, 2.74). CONCLUSIONS: Overall, our findings suggested maternal residential exposure to solvents from industrial sources might be associated with elevated childhood cancer risks.

Carbon disulfide induces accumulation of TDP-43 in the cytoplasm and mitochondrial dysfunction in rat spinal cords.

The relationship between environmental neurotoxicant exposure and neurodegenerative diseases is being extensively investigated. Carbon disulfide, a classic neurotoxicant and prototype of dithiocarbamates fungicides and anti-inflammatory agents, has been detected in urban adults, raising questions about whether exposure to carbon disulfide is associated with a high incidence of neurodegenerative diseases. Here, using rat models and SH-SY5Y cells, we investigated the possible mechanistic linkages between carbon disulfide neurotoxicity and the expression of TDP-43 protein, a marker of amyotrophic lateral sclerosis/frontotemporal lobar degeneration. Our results showed that rats exhibited severe dyskinesia and increased TDP-43 expression in the spinal cord following carbon disulfide exposure. Moreover, carbon disulfide exposure induced abnormal cytoplasmic localization and phosphorylation of TDP-43 in motor neurons. Importantly, carbon disulfide treatment led to the accumulation of TDP-43 in the mitochondria of motor neurons and resulted in subsequent mitochondrial damage, including mitochondrial structural disruption, mitochondrial respiratory chain complex I inhibition, and impaired VCP/p97-dependent mitophagy. In summary, our study provides support for carbon disulfide exposure-mediated TDP-43 mislocalization and mitochondrial dysfunction, contributes to understanding the pathogenesis of environmental neurotoxin-induced neurodegeneration, and provides inspiration for potential therapeutic strategies.

Carbon disulfide exposure induced lung function reduction partly through oxidative protein damage: A cross-sectional and longitudinal analysis.

Carbon disulfide (CS2) exposure has been associated with lung function reduction in occupational population. However, evidence on the general population with relatively low CS2 exposure is lacking and the mechanism involved remains largely unknown. Urinary CS2 metabolite (2-mercaptothiazolidine-4-carboxylic acid, TTCA) and lung function were determined in the urban adults from the Wuhan-Zhuhai cohort at baseline in 2011-2012 and were repeated every 3 years. Cross-sectional and longitudinal associations between TTCA and lung function were estimated using linear mixed models. Inflammation and oxidative damage biomarkers in blood/urine were measured to evaluate their potential mediating roles involved. Cross-sectionally, participants in the highest quartile of TTCA level showed a 0.64% reduction in FEV1/FVC and a -308.22 mL/s reduction in PEF, compared to those in the lowest quartile. Longitudinally, participants with consistently high TTCA level had annually -90.27 mL/s decline in PEF, compared to those with consistently low TTCA level. Mediation analysis revealed that plasma protein carbonyl mediated 49.89% and 22.10% of TTCA-associated FEV1/FVC and PEF reductions, respectively. Conclusively, there was a cross-sectional and longitudinal association between CS2 exposure and lung function reduction in the general urban adults, and protein carbonylation (oxidative protein damage) partly mediated lung function reduction from CS2 exposure.

DNA Damage on Buccal Epithelial Cells, Personal Working in the Rubber Industry Occupationally Exposed to Carbon Disulfide (CS2).

INTRODUCTION: The most significant industrial utilization of carbon disulfide (CS2) has been in the manufacture of cellulose rayon, cellophane, and rubber industry. CS2 prompts expanded recurrence of chromosomal variations in laborers occupationally exposed to CS2. MATERIALS AND METHODS: In the current study, the DNA analysis was carried out from exfoliated buccal epithelial cells from rubber industry workers exposed to CS2 and an equal number of healthy control subjects. Both the control and experimental subjects were categorized by their smoking habits such as smokers (S) and non-smokers (NS). Furthermore, experimental subjects were further separated based on their exposure period. Students t-test statistical tools were used to analyze the final results. RESULTS: The present analysis identified a high frequency of DNA damage in rubber industry workers (16.55±0.43) than control subjects (9.8±0.21). Also, maximum number of DNA damage detected in smoking experimental group (18.27±0.02) than non-smoking experimental (15.02±0.01) and smoking control groups (10.25±0.04 ). CONCLUSION: Smoking habits synergistically increased the DNA damage in the rubber industry workers exposed to CS2.

[Characterization of VOCs Emissions from Caged Broiler House in Winter].

Volatile organic compound (VOCs) emissions from poultry and livestock facilities affect the surrounding environmental quality and human health. However, VOCs emissions from broiler houses have been less characterized, and studies of related dominant odorants, carcinogenic risk, and ozone formation potential are still lacking. To fill this research gap, VOCs pollutants emitted from a broiler house were investigated in this study. The VOCs emission characteristics of the broiler house during three different periods of broiler growth (early, middle, and later) were analyzed using gas chromatography-mass spectrometry. The results showed that 77 types of VOCs were detected, including 16 types of halogenated hydrocarbons, 21 types of alkanes, 5 types of olefins, 12 types of aromatic hydrocarbons, 15 types of oxygenated volatile organic compounds (OVOCs), and 8 types of sulfides. During the entire 42-day growth period, the concentrations of halogenated hydrocarbons, alkanes, olefin, aromatic hydrocarbons, and OVOCs in the broiler house showed few changes. However, with the growth of broilers, the intake of sulfur-containing amino acids and the fecal emission coefficient increased, resulting in the gradual conversion of the VOCs to sulfide. Therefore, emissions of sulfur-containing VOCs increased in the early and middle growth periods. Moreover, the increase in ventilation in the house during the later growth period resulted in a decrease in the sulfur-containing VOCs concentrations. The dominant odorants in the broiler house were naphthalene, ethyl acetate, acetaldehyde, carbon disulfide, dimethyl disulfide, methanethiol, methanethiol, and thiophene. Methanethiol had the highest odorous values, ranging from 2172.4 to 19090.9. Meanwhile, there were acceptable levels of carcinogenic risk in the early and middle growth periods, with a lifetime cancer risk (LCR) of 7.7×10-6 and 4.5×10-6, respectively. The average ozone formation potential (OFP) was (1458.9±787.4) µg·m-3. The results of this study can provide a scientific basis for the monitoring of malodorous substances and formulation of emission reduction strategies in broiler production.

Emission of volatile sulphur compounds during swine manure composting: Source identification, odour mitigation and assessment.

This study aimed to identify the sources of volatile sulphur compounds (VSCs) and evaluate their mitigation by ferric oxide (Fe2O3) during swine manure composting. Four chemicals, including l-cysteine, l-methionine, sodium sulphite, and sodium sulphate, were further added to simulate organic and inorganic sulphur-containing substances in swine manure to track VSC sources during composting. Results show that sulphur simulants induced the emission of six common VSCs, including methyl sulphide (Me2S), dimethyl sulphide (Me2SS), carbonyl sulphide (COS), carbon disulphide (CS2), methyl mercaptan (MeSH), and ethyl mercaptan (EtSH), during swine manure composting. Of them, COS, CS2, MeSH and Me2SS were predominantly contributed by the biodegradation of methionine and cysteine, while Me2S and EtSH were dominated by the reduction of sulphite and sulphate. Further Fe2O3 addition at 1.5 % of total wet weight of composting materials immobilized elemental sulphur and inhibited sulphate reduction to reduce the emission of VSCs by 46.7-80.9 %. Furthermore, odour assessment indicated that adding Fe2O3 into composting piles significantly reduced the odour intensity level to below 4, the odour value of VSCs by 47.1-81.3 %, and thus the non-carcinogenic risk by 68.4 %.

Volatile organic compounds emission in the rubber products manufacturing processes.

Volatile organic compounds (VOCs) emission from rubber products manufacture processes, mixing, shaping and vulcanization were investigated in four rubber products factories in China. The source emission air was passively sampled by pre-vacuumized stainless steel canister and analyzed by gas chromatography-mass spectrometry-flame ionization detection (GC/MS-FID). The species profile of 107 VOCs in the emission processes were obtained. We calculated the photochemical ozone formation potential (OFP) and carcinogenic risk (CR) of the VOCs for each manufacture process. The results showed that mixing process mainly released dichloromethane (14.53%), carbon disulfide (CS2) (6.88%), styrene (5.72%), 4-methyl-2-pentanone (5.22%) and naphthalene (3.69%) for solvents used and raw rubber degradation in the process. The C6-C8 alkanes, especially heptane and isomers of heptane (44.71%), were dominated in shaping process. The major species released from vulcanization process were carbon disulfide (29.72%), naphthalene (8.17%), acetone (7.73%) and dichloromethane (4.26%). VOCs emitted from vulcanization process had the highest OFP, which contributed by naphthalene, m/p-xylene, o-xylene and carbon disulfide. VOCs emission from mixing process had the highest CR, and 1,2-dibromoethane, 1,2-dichlorethane and 1,3-butadiene were the main contributors to CR. We also estimated the total VOCs emissions into the atmosphere from tires manufacturing in China, which were 7.58 × 105 t in 2018 and contributed about 9% of total industry processes VOCs emissions.

Influence of dissolved organic matter on carbonyl sulfide and carbon disulfide formation from dimethyl sulfide during sunlight photolysis.

Carbonyl sulfide (COS) and carbon disulfide (CS2 ) are important atmospheric gases photochemically generated from organic sulfur precursors in sunlit natural waters. This study examined these processes by evaluating COS and CS2 photoproduction from dimethyl sulfide (DMS) in the presence of dissolved organic matter (DOM). DOM was added because it photochemically produces various reactive intermediates (3 CDOM*, • OH, 1 O2 , and H2 O2 ) potentially involved in these reaction pathways. DMS-amended synthetic waters at pH 8 were varied in terms of their DOM type and concentration, spiked with the 3 CDOM* quenching agent, phenol, in certain cases, and subsequently irradiated over varying exposure times. Results indicated that various DOM types ranging from freshwater to open-ocean DOM increased COS but did not alter CS2 , which remained at nondetect levels. DOM type influenced COS only at higher concentrations (20 mg/L), whereas increasing DOM concentrations proportionally increased COS concentrations for all DOM types. Phenol addition lowered COS formation for reasons that remained unclear because phenol likely quenched 3 CDOM* and DMS-derived sulfur-based radicals. Further comparisons with DMS-spiked natural waters and cysteine (CYS)-spiked synthetic and natural waters assessed previously indicated that COS formation from both precursors in natural waters was always greater than in waters containing DOM alone. PRACTITIONER POINTS: DMS- and DOM-spiked synthetic waters formed COS but did not form CS2 during sunlight photolysis. In DMS-spiked synthetic solutions, DOM type has a limited influence on COS formation whereas DOM concentration has a stronger influence on COS formation. COS formation in the DMS-spiked synthetic waters was fairly proportional to the DOC concentration but was generally lower than COS formation in DMS-spiked natural waters.

Enabling Oxygen-Sulfur Exchange Reaction to Produce Semicrystalline Copolymers from Carbon Disulfide and Ethylene Oxide.

This work describes the first example of semicrystalline poly(thiocarbonate)s from carbon disulfide (CS2 ) and ethylene oxide (EO), two mass producible low-cost monomers. Lewis acid/base pairs (LPs) exhibit high activity (EO conversion up to >99%, 8 h) in catalyzing the copolymerization under low Lewis pair/monomer ratio of 1:1500. Oxygen-sulfur exchange reaction (O-S ER) during the copolymerization of CS2 and EO, the generation and mutual copolymerization with COS, CO2 , and episulfide, is harnessed to introduce crystallizable segments [SC(O)O and SC(S)S] in the copolymer. The type of Lewis base is found to have a great impact on the chain microstructure and the crystalline properties. The formed copolymers with melting point from 117.7 to 245.3 °C are obtained. The maximum crystallinity is estimated to be 78% based on the powder wide-angle X-ray diffraction pattern. This work provides a general method to prepare semicrystalline sulfur-containing polymers.

Influence of dissolved organic matter on carbonyl sulfide and carbon disulfide formation from cysteine during sunlight photolysis.

Carbonyl sulfide (COS) and carbon disulfide (CS2) are important atmospheric gases that are formed from organic sulfur precursors present in natural waters when exposed to sunlight. However, it remains unclear how specific water constituents, such as dissolved organic matter (DOM), affect COS and CS2 formation. To better understand the role of DOM, irradiation experiments were conducted in O2-free synthetic waters containing four different DOM isolates, acquired from freshwater to open ocean sources, and the sulfur-based amino acid, cysteine (CYS). CYS is a known natural precursor of COS and CS2. Results indicated that COS formation did not vary strongly with DOM type, although small impacts were observed on the kinetic patterns. COS formation also increased with increasing CYS concentration but decreased with increasing DOM concentration. Quenching experiments indicated that ˙OH was not involved in the rate-limiting step of COS formation, whereas excited triplet states of DOM (3CDOM*) were plausibly involved, although the quenching agents used to remove 3CDOM* may have reacted with the CYS-derived intermediates as well. CS2 was not formed under any of the experimental conditions. Overall, DOM-containing synthetic waters had a limited to no effect towards forming COS and CS2, especially when compared to the higher concentrations formed in sunlit natural waters, as examined previously. The reasons behind this limited effect need to be explored further but may be due to the additional water quality constituents present in these natural waters. The findings of this study imply that multiple variables beyond DOM govern COS and CS2 photoproduction when moving from freshwaters to open ocean waters.

[Determination of isobutyl methacrylate in workplace air by gas chromatography].

Objective: To establish a gas chromatography method for detecting isobutyl methacrylate in workplace air. Methods: From July to October 2019, isobutyl methacrylate in workplace air was collected by activated charcoal tube, absorbed using carbon disulfide and analyzed by gas chromatography (FID) with FFAP capillary column. Results: The linear range of isobutyl methacrylate in the method was 0-800 µg/ml, the correlation coefficient was 0.99993. The detection limit was 0.35 µg/ml. The lowest detected concentration was 0.12 mg/m(3). The within-run precision was 2.06%-2.72%, the between-run precision was 3.03%-3.83%. The rates of desorption was 96.7%. The breakthrough volume was 14.46 mg. The average sampling efficience was 100%. The samples could be stored at room temperature for 7 days. Conclusion: The method is simple, highly sensitive and precise. Isobutyl methacrylate in workplace air could be determined accurately.

Carbon disulfide induced decidualization disorder in the mice uterus at the window of implantation.

Carbon disulfide (CS2) is regarded as a common occupational poison that is widely used in the textile industry in China. Our previous research suggests that CS2 can induce significant implantation disorders in pregnant mice; however, the specific mechanism remains unclear. Uterine conception in mice must undergo decidualization, which is the prerequisite for propitious blastocyst implantation into the endometrium. Therefore, in this study, we established models of pregnant mice to explore the toxic effects of CS2 on decidualization to elucidate the basic mechanism of implantation disorder after CS2 exposure. The uterine tissues were immediately collected according to the predetermined endpoints to measure the expression levels of IGFBP1 and PRL (markers of decidualization differentiation), IL-11 (representing the secretory function of decidual cells), AKT and pAKT by western blotting, RT-PCR, immunohistochemical staining, H&E staining and ELISA. N-carbamoyl glutamic acid (NCG) acted as an agonist of AKT to verify the upstream regulatory mechanism of decidualization disorder by CS2. The results showed that the normal reaction of decidual transformation was obviously disrupted by CS2 upon 3.5 dpc and 4.5 dpc exposure. The blastocyst did not adhere to the epithelium after 3.5 dpc-exposure and did not invade the endometrium after 4.5 dpc-exposure, resulting in its suspension in the uterine cavity, stagnation and eventual loss. The proteins expression levels were decreased by 95.2% for IGFBP1 and 76.2% for PRL at the 4.5 dpc endpoint after 3.5 dpc CS2 exposure compared with the control. Simultaneously, the mRNA and protein expression levels of IL-11 in uterine tissues were significantly reduced by CS2, and consistent decreasing trends over time were observed for IGFBP1 and PRL, compared with the control. Additionally, the ratio of pAKT/AKT protein expression was decreased by 72.2% and 94.8% at 12 h and 18 h after 3.5 dpc exposure and by 53.3% and 74.3% at 6 h and 12 h after 4.5 dpc exposure, respectively, compared with the corresponding controls. Furthermore, NCG could recover the IGFBP1 and PRL protein expression, which was increased by 27.5% and 52.3% at 4.5 dpc and 6.5 dpc, respectively, after 3.5 dpc exposure for IGFBP1 and by 30.3% at 6.5 dpc after 4.5 dpc exposure for PRL, compared with CS2 exposure alone. Collectively, this study suggested that the decidualization disorder caused by CS2 at the window of implantation in pregnant mice, which is triggered by pAKT, contributed to the implantation disorder and eventually led to embryo loss. It is worth noting that our study may provide a new perspective and reference for exploring the toxic mechanism of implantation disorder and even infertility in harmful circumstances.

Renal injury following long-term exposure to carbon disulfide: analysis of a case series.

BACKGROUND: To investigate the clinicopathological characteristics of renal damage caused by long-term exposure to carbon disulfide (CS2) in nine patients. METHODS: All the patients underwent ultrasound-guided renal biopsy. All specimens were examined by light microscopy and immunohistochemistry (IHC). Samples form one patient were further analyzed using transmission electron microscopy. RESULTS: Similar pathological changes were observed in all patients, but the degrees of lesions were different. All cases had moderate to severe nodular mesangial hyperplasia; among these, type "Kimme1stie1-Wi1son" (K-W nodule for short) was observed in four cases, type "K - W nodule" refer to nodular hyperplasia of mesangial membrane like letter K or W. four cases had proliferative extracapillary glomerulonephritis (GN), while there were no concomitant changes in one patient. Besides, six cases had diffuse basement membrane thickening, focal segmental sclerosis or bulbar sclerosis; two cases had diffuse glomerular sclerosis, and one case had focal segmental capillary hyperplasia. Moreover, all patients had renal tubular atrophy/interstitial fibrosis with less to moderate chronic inflammatory cell infiltration, as well as renal arteriosclerosis. IHC showed that the depositions of IgA, IgM, C3d, C4d, C1q and Fib were not specific; while IgG, type III collagen, Fibronectin, Amyloid A, Igκ, Igλ, HBsAg and HBcAg were all negative. CONCLUSION: Diffuse nodular mesangial hyperplasia/sclerosing glomerular nephropathy is characterized by nodular mesangial hyperplasia with type "K-W nodules" formation, which we speculate is a special pathological manifestation of renal damage caused by carbon disulfide (CS2).

Carbon Disulfide Induces Embryo Implantation Disorder by Disturbing the Polarization of Macrophages in Mice Uteri.

Carbon disulfide (CS2) induces embryo implantation disorders. Macrophages participate in the process of pregnancy. Therefore, we want to explore the effects of CS2 exposure on polarization and immune function of macrophages in pregnant mice uteri. The exposure times were gestation days 3 (GD3), 4 (GD4), and 5 (GD5), and the observation end points were arranged in a time series after CS2 exposure. The uterine tissues were collected to detect the expression levels of macrophages cytokines (IL-6, IL-12, TGF-ß1, and Vegf-a) and downstream regulatory cytokines of Th1-type (IL-2 and IFN-γ) and Th2-type (IL-10 and IL-4) by flow cytometry, ELISA, and q-PCR. The results showed that, compared with the controls, the ratios of M1/M2 macrophages in the endometrium significantly increased by 96%, 110%, and 177% at the GD4, GD6, and GD7 observation end points after GD3 exposure and increased about 3.88-fold and 2.37-fold at the GD6 and GD7 observation end points after GD4 exposure, respectively. In contrast, the ratio of M1 and M2 macrophages significantly reduced by 53% at the GD5 observation end point after GD3 exposure. Meanwhile, the expression levels of IL-6 were significantly increased about 2.00-fold for mRNA and 1.60-fold for protein at GD4 observation end points after GD3 exposure, and the mRNA levels of IL-12 increased about 3.61-fold at the GD6 observation end points after GD4 exposure. The mRNA levels of TGF-ß1 were significantly decreased by 41%, 25%, and 20% at the GD7 observation end points after exposure at GD3, GD4, and GD5, and the expression levels of Vegf-a mRNA and protein were decreased. Furthermore, the ratio of IL-2/IL4, IL-2/IL-10, IFN-γ/IL-4, and IFN-γ/IL-10 in the uterine tissue was significantly increased at the exposure groups. These findings suggest that the imbalanced polarization of macrophages is the key regulator in the progress of CS2-induced embryo loss.

The suppressed autophagy induced by carbon disulfide could be rescued by N-carbamoyl glutamate during the window of embryo implantation in mice.

OBJECTIVES: To explore the effects of carbon disulfide (CS2) and N-carbamoyl glutamate (NCG) on autophagy during the window of embryo implantation in mice and whether dietary NCG supplementation can promote embryo implantation in case of CS2 exposure. METHODS: Pregnant mice that received single intraperitoneal injection of CS2 on Gestational day (GD)4 were fed basal diet with or without NCG supplementation from GD1 to endpoints. The control mice were injected solvents. There were four endpoints (GD5, GD6, GD7 and GD9 endpoints) in each group. The uterus was collected on endpoints to detect autophagy-related markers by using the methods of transmission electron microscopy (TEM), immunohistochemistry (IHC), quantitative real-time polymerase chain reaction (qRT-PCR) and ELISA. RESULTS: The P62 brown punctate staining increased in CS2 exposure group and reduced after dietary NCG supplementation, which was opposite with LC3B, Beclin1 and ATG5 on GD5 endpoint. Simultaneously, P62 protein expression raised 43.33% on GD5 endpoint (p < 0.01) when exposed to CS2 and descended to the control level after NCG supplementation. The rate of decline of LC3B and Beclin1 proteins were 27.04% (p < 0.01) and 23.27% (p < 0.05) on GD5 endpoint, 20.20% (p < 0.05) and 11.30% on GD7 endpoint in CS2 exposure group, respectively, then NCG supplementation caused the LC3B and Beclin1 protein expression to rise in different degrees. Comparatively, the mRNA expression of all autophagy-related gene changed more apparently on three endpoints than the protein expression. The images of TEM showed that nearly no autophagosome could be seen in CS2 exposure group, while dietary NCG supplementation increased the number of autophagosome obviously on GD5 endpoint. The number of implanted embryos which declined due to CS2 exposure returned to normal in NCG supplementation group. CONCLUSIONS: Dietary NCG supplementation could rescue the suppressed autophagy induced by CS2 in the window of implantation and increase the number of implanted embryos.

Carbon disulfide induces embryo loss by perturbing the expression of the mTOR signalling pathway in uterine tissue in mice.

Understanding of the mechanism of embryo loss is critical for successful pregnancy considering an increase in the incidence of infertility. In this study, we focus on the effect of alterations in the expression of the AKT/AMPK/mTOR signalling pathway in mouse uterine tissue after embryo loss induced by harmful environmental exposure to carbon disulfide (CS2). CS2 is a material used in certain production processes, and women are sometimes exposed to it in occupational settings. We created an animal model of gestating mice exposed to CS2 on gestation days 3 (GD3), 4 (GD4), 5 (GD5) and 6 (GD6) with various corresponding endpoints after the exposure. The uterine tissue was collected according to the endpoint time series to detect the expression levels of mTOR, p-mTOR, pAKT, and pAMPK using western blot, RT-PCR, immunohistochemistry staining, and ELISA. Dietary supplementation with N-carbamoyl glutamic acid (NCG) was used to verify the effect of the mTOR signalling pathway on embryo loss caused by CS2. We detected down-regulation of the levels of the mTOR and p-mTOR proteins; the levels of these two proteins were decreased by 49.35% and 51.44% at the GD5 endpoint after GD4 exposure and by 38.55% and 59.51% after GD3 exposure, respectively. The change in the expression level of mTOR mRNA was consistent with the protein expression, and the mRNA level at the GD5 endpoint was decreased by 55.0% after GD4 exposure (P < 0.05). Additionally, protein expression levels of pAKT were decreased by 49.05%, and the levels of pAMPK were increased by 25.51% at the GD5 endpoint after GD4 exposure (P < 0.05). A similar trend was observed for pAKT and pAMPK at the GD4 endpoint after GD3 exposure, at the GD6 endpoint after GD5 exposure, and at the GD7 endpoint after GD6 exposure (P < 0.05). Supplementation with NCG contributed to recovery from the effects of CS2 by increasing the protein expression levels of mTOR and pAKT by 47.54% and 63.79% (P < 0.05), respectively, while the pAMPK protein level was decreased by 37.15% (P < 0.05) at the GD5 endpoint after GD4 exposure. It should be noted that the number of implanted embryos was significantly increased after supplementation with NCG. Our results indicate that down-regulation of mTOR at the time of implantation is regulated by pAKT and pAMPK, that may be an important factor for embryo loss induced by CS2.

[Study on determination of ethylal in workplace air by gas chromatography].

Objective: A solvent desorption-gas chromatography method for determination of ethylal in workplace air has been established. Methods: Ethylal in workplace air was collected by activated carbon tube and desorbed with carbon disulfide, and the desorption solutions were analysed by capillary column GC with FID detector. Results: The method presented a good linearity in the range of 0.87~34 800.00 mg/L of ethylal in the standard solution, with the correlation coefficient being r=0.999 7. The limit of detection and the limit of quantification of this method were respectively 0.20 mg/L and 0.80 mg/L, and the minimum detectable concentration and the minimum quantification concentration of this method were respectively 0.17 mg/m(3) and 0.60 mg/m(3) per 1.50 L of air.The within-run precision of the method was 2.93%-6.20%, and the between-run precision 3.67%-6.44%. The desorption efficiency between 94.22%-97.27%. Ethylal in activated carbon tube could be kept at least 7 days at room temperature without significant loss. Conclusion: The method could be used for determination of ethylal in workplace air.

[Embryo implantation dysfunction via the decreased uterine dendritic cells's non-immune function after exposed to carbon disulfide].

Objective: To study the effect of CS2 on dendritic cells (DCs) in the uterus and the expression of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor(fms-like tyrosine kinase-1, Flt-1), and to explore the toxic mechanism of CS2-induced embryo implantation dysfunction. Methods: The Kunming mice were randomly divided into control group,gestational day 4(GD4) exposure group and GD5 exposure group. The endpoints of each group(GD5, GD6, GD7) was set up according to their respective exposure time points. The mice in the exposure group were given intraperitoneal injection of CS2 at an injection dose of 631.4 mg/kg and the control group was given olive oil. The effect of CS2 on DCs in the uterus of pregnant mice was observed by flow cytometry. The levels of VEGF and Flt-1 were measured by Real-time quantitative polymerase chain reaction (qPCR) and enzyme-linked immunosorbent assay (ELISA). Results: In the GD4 and GD5 exposure groups, the number of DCs in the uterus of pregnant mice decreased at all endpoints and the GD5 endpoint in the GD4 exposure group decreased by 21%(P=0.039), when compared with the control group. In the GD4 exposure group, the levels of VEGF mRNA and protein in the uterus of the pregnant mice were 79% and 30% lower than those in the control group, respectively (P=0.03、P=0.017); the levels of Flt-1 mRNA and protein at the endpoints of GD6 and GD7 in the uterus decreased by 54%, 36%, 60% and 56%, respectively, when compared with the control group(P=0.017、P=0.012、P=0.004、P=0.007). In the GD5 exposure group, the levels of VEGF mRNA and protein in the uterus of pregnant mice at the endpoint of GD7 decreased by 62% and 36%, when compared with the control group (P=0.005、P=0.035); the levels of Flt-1 mRNA and protein in the uterus at the endpoint of GD7 decreased by 60% and 44%, respectively, when compared with the control group (P=0.004、P=0.009). Conclusion: CS2 reduced the number of DCs in the uterus of pregnant mice, and affected the non-immune function of DCs, which affected uterine angiogenesis, this may be one of the mechanisms of CS2-induced embryo implantation dysfunction.

Indirect Photochemical Formation of Carbonyl Sulfide and Carbon Disulfide in Natural Waters: Role of Organic Sulfur Precursors, Water Quality Constituents, and Temperature.

Carbonyl sulfide (COS) and carbon disulfide (CS2) are volatile sulfur compounds that are critical precursors to sulfate aerosols, which enable climate cooling. COS and CS2 stem from the indirect photolysis of organic sulfur precursors in natural waters, but currently the chemistry behind how this occurs remains unclear. This study evaluated how different organic sulfur precursors, water quality constituents, which can form important reactive intermediates (RIs), and temperature affected COS and CS2 formation. Nine natural waters ranging in salinity were spiked with cysteine, cystine, dimethylsulfide (DMS), or methionine and exposed to simulated sunlight over varying times and water quality conditions. Results indicated that COS and CS2 formation increased up to 11× and 4×, respectively, after 12 h of sunlight, while diurnal cycling exhibited varied effects. COS and CS2 formation was also strongly affected by the DOC concentration, organic sulfur precursor type, O2 concentration, and temperature, while salinity differences and CO addition did not play a significant role. Overall, important factors in forming COS and CS2 were identified, which may ultimately impact their atmospheric concentrations.

Simple Determination of Gaseous and Particulate Compounds Generated from Heated Tobacco Products.

As a new form of cigarettes, heated tobacco products (HTPs) have been rapidly distributed worldwide. In this study, an improved method for analyzing gaseous and particulate compounds generated from HTPs is described. Smoke is collected using a GF-CX572 sorbent cartridge with 300 mg of carbon molecular sieves, that is, Carboxen 572 (CX572), and a 9 mm glass-fiber filter (GF). After collection, the CX572 particles from the cartridge are transferred along with the GF and deposited into a vial containing two phases of carbon disulfide and methanol. The CX572 particles settle into the lower carbon disulfide phase, while nonpolar compounds are desorbed. After the sample is allowed to stand, the solution is slowly stirred. The two-phase mixture of carbon disulfide and methanol is combined into a homogeneous solution. Polar compounds are then desorbed, while the desorbed nonpolar compounds remain in solution. For the analysis of carbonyl compounds, an enriched 2,4-dinitrophenylhydrazine solution is added to a portion of the combined solution for derivatization and subsequent high-performance liquid chromatography analysis. For the analysis of volatile organic compounds and water, a portion of the combined solution is analyzed by gas chromatography-mass spectrometry or equipped with a thermal conductivity detector. By applying the proposed GF-CX572 one-cartridge method to the analysis of the mainstream smoke generated from HTPs and traditional cigarettes, several chemical compounds are detected, and the chemical composition of smoke is revealed. The GF-CX572 one-cartridge method can analyze gaseous and particulate chemical compounds from the HTP smoke by utilizing not only the entire puff volume but also one puff volume because the GF-CX-572 cartridge can be replaced with a new cartridge within 3 s. An overview of the chemicals generated from HTPs is obtained in detail by one-puff volume sampling. In addition, the generated chemical compounds strongly depend on the temperature of tobacco leaves in HTPs.