Sub-ppt level detection of carbon monoxide and nitrous oxide enabled by mid-infrared doubly resonant photoacoustic spectroscopy.

We report highly sensitive detection of carbon monoxide (CO) and nitrous oxide (N2O) using doubly resonant photoacoustic spectroscopy paired with a quantum cascade laser (QCL) at 4.57 µm. The butterfly-packaged QCL is used to exploit the CO absorption line at 2190.02 cm-1 and the N2O absorption line at 2191.42 cm-1 by scanning the injection current. Leveraging the simultaneous acoustic and optical resonances and adopting a lower photoacoustic detection frequency, we achieve a minimum detection limit of 0.85 part-per-trillion (ppt) for CO over the 500 s averaging time, and 0.7 ppt for N2O over the 200 s averaging time. Our approach demonstrates record sensitivity for CO and N2O detection compared to state-of-the-art optical gas sensors.

FMOD Alleviates Depression-Like Behaviors by Targeting the PI3K/AKT/mTOR Signaling After Traumatic Brain Injury.

Depression frequently occurs following traumatic brain injury (TBI). However, the role of Fibromodulin (FMOD) in TBI-related depression is not yet clear. Previous studies have suggested FMOD as a potential key factor in TBI, yet its association with depression post-TBI and underlying mechanisms are not well understood. Serum levels of FMOD were measured in patients with traumatic brain injury using qPCR. The severity of depression was assessed using the self-depression scale (SDS). Neurological function, depressive state, and cognitive function in mice were assessed using the modified Neurological Severity Score (mNSS), forced swimming test (FST), tail suspension test (TST), Sucrose Preference Test (SPT), and morris water maze (MWM). The morphological features of mouse hippocampal synapses and neuronal dendritic spines were revealed through immunofluorescence, transmission electron microscopy, and Golgi-Cox staining. The protein expression levels of FMOD, MAP2, SYP, and PSD95, as well as the phosphorylation levels of the PI3K/AKT/mTOR signaling pathway, were detected through Western blotting. FMOD levels were decreased in TBI patients' serum. Overexpression of FMOD preserved neuronal function and alleviated depression-like behaviour, increased synaptic protein expression, and induced ultrastructural changes in hippocampal neurons. The increased phosphorylation of PI3K, AKT, and mTOR suggested the involvement of the PI3K/AKT/mTOR signaling pathway in FMOD's protective effects. FMOD exhibits potential as a therapeutic target for depression related to TBI, with its protective effects potentially mediated through the PI3K/AKT/mTOR signaling pathway.

Oasis of the deep: Cold-water corals of the South China Sea.

Cold-water coral (CWC) communities are biodiversity hotspots on the world's deep seafloor. Although deep-sea corals in the South China Sea (SCS) have been reported before, they are only sporadic. A comprehensive and systematic understanding of the CWC in the SCS would forge the basis for future protection. Here we conducted the first systematic survey on the CWCs in the following six broad-scale sub-regions, from the northwest and northeast slopes to the seamounts in the western and central basins of the SCS, through twenty-four dives of the human-occupied vehicle ShenhaiYongshi. Statistical analysis provided detailed information on the distribution, abundance, size, diversity, and density of CWCs and the in situ environmental conditions supporting coral habitats. We found that the SCS hosted highly diversified coral communities, including twelve genera of gorgonians, six genera of black corals, and one genus of stony corals. The differences in the spatial distribution patterns of coral communities suggested that several environmental variables (depth, temperature, salinity, substrate, and geomorphology) might influence the development of CWCs in the SCS. The intermediate water layer of the SCS appeared to provide suitable habitat for deep-sea coral communities and potentially promoted connectivity. Furthermore, differences between sub-regions within the SCS may be an important factor responsible for the biogeographic patterns of CWCs. These sub-regions of CWCs were observed to range from 0.004 to 0.622 corals m-2, with an average of 0.139 corals m-2. The mean density of CWCs in the SCS was relatively high compared to well-studied CWC hotspots. Overall, the results revealed the significance of the SCS as an important CWC hotspot in the world. These findings provide a fundamental basis for the protection of deep-sea coral assemblages in the SCS.

Recent advances in the role of miRNAs in post-traumatic stress disorder and traumatic brain injury.

Post-traumatic stress disorder (PTSD) is usually considered a psychiatric disorder upon emotional trauma. However, with the rising number of conflicts and traffic accidents around the world, the incidence of PTSD has skyrocketed along with traumatic brain injury (TBI), a complex neuropathological disease due to external physical force and is also the most common concurrent disease of PTSD. Recently, the overlap between PTSD and TBI is increasingly attracting attention, as it has the potential to stimulate the emergence of novel treatments for both conditions. Of note, treatments exploiting the microRNAs (miRNAs), a well-known class of small non-coding RNAs (ncRNAs), have rapidly gained momentum in many nervous system disorders, given the miRNAs' multitudinous and key regulatory role in various biological processes, including neural development and normal functioning of the nervous system. Currently, a wealth of studies has elucidated the similarities of PTSD and TBI in pathophysiology and symptoms; however, there is a dearth of discussion with respect to miRNAs in both PTSD and TBI. In this review, we summarize the recent available studies of miRNAs in PTSD and TBI and discuss and highlight promising miRNAs therapeutics for both conditions in the future.

[Chemical constituents from fruits of Morinda citrifolia and their inhibitory effects on proliferation of synoviocytes in vitro].

The chemical constituents from the fruits of Morinda citrifolia were systematically explored by chromatographic fractionation methods including silica gel, octadecylsilyl(ODS) gel, Sephadex LH-20 gel, and preparative high performance liquid chromatography(pre-HPLC). The chemical structures of all isolated compounds were identified on the basis of their physicochemical properties, spectroscopic analyses, as well as the comparisons of their physicochemical and spectroscopic data with the reported data in literature. As a result, 22 isolated compounds from the 90% ethanol extract of the fruits of M. citrifolia were identified, which were moricitritone(1), 2'-deoxythymidine(2), cyclo-(L-Pro-L-Tyr)(3), methyl-5-hydroxy-2-pyridinecarboxylate(4), methyl pyroglutamate(5), bisbenzopyran(6), epipinoresinol(7), 3, 3'-bisdemethyl pinoresinol(8), 3, 3'-bisdemethyltanegool(9), trimesic acid(10), crypticin B(11), kojic acid(12), vanillic acid(13), protocatechoic acid(14), 5-hydroxymethyl furfural(15), blumenol A(16), 1-O-(9Z, 12Z-octadecadienoyl) glycerol(17), mucic acid dimethylester(18), methyl 2-O-ß-D-glucopyranosylbenzoate(19), 2-phenylethyl-O-ß-D-glucoside(20), scopoletin(21), and quercetin(22). Among them, compound 1 was a new pyrone derivative, compounds 2, 4-7, 10-12, and 17 were isolated from the plants belonging to Morinda genus for the first time, and compound 18 was obtained from M. citrifolia for the first time. Moreover, on the basis of testing the activities of all isolated compounds on inhibiting the proliferation of synovial fibroblasts in vitro by MTS assay, the anti-rheumatoid arthritis activities of all isolated compounds were initially evaluated. The results showed that compounds 1-6, 9, 19, and 20 exhibited remarkable anti-rheumatoid arthritis activities, which displayed the inhibitory effects on the proliferation of MH7A synovial fibroblast cells with the IC_(50) values in the range of(3.69±0.08) to(168.96±0.98) µmol·L~(-1).

Greenhouse gases emissions and dissolved carbon export affected by submarine groundwater discharge in a maricultural bay, Hainan Island, China.

Greenhouse gases (GHG) emissions in coastal areas are influenced by both mariculture and submarine groundwater discharge (SGD). In this study, we first conducted a comprehensive investigation on carbon dioxide (CO2) and methane (CH4) emissions affected by SGD in a typical maricultural bay in north-eastern Hainan Island, China. A radon (222Rn) mass balance model revealed considerable high SGD rates (179 ± 92 cm d-1) in the bay, and the fluxes of SGD-derived dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) were 150.36 and 3.65 g C m-2 d-1, respectively. Time-series measurement results, including those for 222Rn, CH4, CO2, and physicochemical parameters, indicated that GHG dynamics in the maricultural bay mainly varied with tidal fluctuations, and isotopic evidence further revealed that acetate fermentation was the main mechanism of methanogenesis in the maricultural waters. The water-air fluxes in the maricultural area were 1.05 ± 0.32 and 9.49 ± 3.96 mmol m-2 day-1 for CH4 and CO2, respectively, implying that Qinglan Bay was a potential source of GHG released into the atmosphere. At the bay-scale, the CO2 emissions followed a spatial pattern, and the CH4 emissions were mainly affected by mariculture. The high CH4 emissions in the maricultural waters caused by maricultural activities, SGD, high temperature, and special hydrology resulted in the formation of the CH4-dominated total CO2-equivalent emissions model. Our study highlights the importance of considering the link between SGD and GHG emissions in maricultural bays when constraining global GHG fluxes.

Protective effects and regulatory pathways of melatonin in traumatic brain injury mice model: Transcriptomics and bioinformatics analysis.

Traumatic brain injury (TBI) is the leading cause of disability and mortality globally. Melatonin (Mel) is a neuroendocrine hormone synthesized from the pineal gland that protects against TBI. Yet, the precise mechanism of action is not fully understood. In this study, we examined the protective effect and regulatory pathways of melatonin in the TBI mice model using transcriptomics and bioinformatics analysis. The expression profiles of mRNA, long non-coding RNA (lncRNA), microRNA (miRNA), and circular RNA (circRNA) were constructed using the whole transcriptomes sequencing technique. In total, 93 differentially expressed (DE) mRNAs (DEmRNAs), 48 lncRNAs (DElncRNAs), 59 miRNAs (DEmiRNAs), and 59 circRNAs (DEcircRNAs) were identified by the TBI mice with Mel treatment compared to the group without drug intervention. The randomly selected coding RNAs and non-coding RNAs (ncRNAs) were identified by quantitative real-time polymerase chain reaction (qRT-PCR). To further detect the biological functions and potential pathways of those differentially expressed RNAs, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were executed. In our research, the regulatory network was constructed to show the relationship of lncRNA-RBPs. The lncRNA-mRNA co-expression network was established based on the Pearson coefficient to indicate the expression correlations. Moreover, the DEcircRNA-DEmiRNA-DEmRNA and DElncRNA-DEmiRNA-DEmRNA regulatory networks were constructed to demonstrate the regulatory relationship between ncRNAs and mRNA. Finally, to further verify our predicted results, cytoHubba was used to find the hub gene in the synaptic vesicle cycle pathway, and the expression level of SNAP-25 and VAMP-2 after melatonin treatment were detected by Western blotting and immunofluorescence. To sum up, these data offer a new insight regarding the molecular effect of melatonin treatment after TBI and suggest that the high-throughput sequencing and analysis of transcriptomes are useful for studying the drug mechanisms in treatment after TBI.

[Chemical constituents from Artocarpus incisus and their inhibitory effects on proliferation of synoviocytes in vitro].

The chemical constituents from the branches and leaves of Artocarpus incisus were isolated and purified via silica gel, ODS, and Sephadex LH-20 column chromatography as well as preparative HPLC. The chemical structures of all isolated compounds were identified in the light of their physicochemical properties, spectroscopic analyses, and comparisons of their physicochemical and spectroscopic data with the reported data in literature. As a result, 20 compounds were isolated and characterized from the 90% ethanol extract of the branches and leaves of A. incisus, which were identified as tephrosin(1), 6-hydroxy-6 a, 12 a-dehydrodeguelin(2), sarcolobin(3), lupiwighteone(4), 12-deoxo-12α-methoxyelliptone(5), 6 aα,12 aα-12 a-hydroxyelliptone(6), homopterocarpin(7), 3-hydroxy-8,9-dimethoxypterocarpan(8), pterocarpin(9), maackiain(10), medicarpin(11), calycosin(12), genistein(13), formononetin(14), 5-hydroxy-4',7-dimethoxy isoflavone(15), liquiritigenin(16), 4(15)-eudesmene-1ß,7α-diol(17), ent-4(15)-eudesmene-1ß,6α-diol(18), 1α-hydroxyisodauc-4-en-15-al(19), and guaianediol(20). Except compounds 13 and 16, all other compounds were isolated from the Artocarpus plants for the first time. Additionally, using MTS assay, compounds 1-20 were eva-luated for their anti-rheumatoid arthritis activities by measuring their anti-proliferative effects on synoviocytes in vitro. As a consequence, compounds 1-16 showed notable anti-rheumatoid arthritis activities, which displayed inhibitory effects on the proliferation of MH7 A synovial fibroblast cells, with the IC_(50) values in range of(9.86±0.09)-(218.07±1.96) µmol·L~(-1).

Syzysamalactone, an Unusual 11-Carbon δ-Lactone Derivative from the Fresh Ripe Fruits of Syzygium samarangense (Wax Apple).

To study the chemical constituents from the ripe fresh fruits of Syzygium samarangense (wax apple) and their potential health effects, a phytochemical investigation was undertaken. A new δ-lactone derivative, syzysamalactone (1), along with a known biogenetically related δ-lactone derivative, 6-pentyl-α-pyrone (2), were isolated from the fresh ripe fruits of S. samarangense. Syzysamalactone (1) is an unusual 11-carbon δ-lactone derivative, and its chemical structure and absolute configuration were elucidated by spectroscopic data analysis. A plausible biogenetic pathway for 1 was also proposed. Furthermore, the potential neuroprotective effects of compounds 1 and 2 were assessed. As a result, compounds 1 and 2 displayed notable neuroprotective effects with EC50 values of 0.29 ± 0.03 and 1.28 ± 0.06 µM, respectively, using the SH-SY5Y human neuroblastoma cell line. This is the first report of δ-lactone derivatives showing significant neuroprotective activities.

The Whole-transcriptome Landscape of Diabetes-related Sarcopenia Reveals the Specific Function of Novel lncRNA Gm20743.

While the exact mechanism remains unclear, type 2 diabetes mellitus increases the risk of sarcopenia which is characterized by decreased muscle mass, strength, and function. Whole-transcriptome RNA sequencing and informatics were performed on the diabetes-induced sarcopenia model of db/db mice. To determine the specific function of lncRNA Gm20743, the detection of Mito-Sox, reactive oxygen species, Ethynyl-2'-deoxyuridine, and myosin heavy chain was performed in overexpressed and knockdown-Gm20743 C2C12 cells. RNA-seq data and informatics revealed the key lncRNA-mRNA interactions and indicated a potential regulatory role of lncRNAs. We characterized three core candidate lncRNAs Gm20743, Gm35438, 1700047G03Rik, and their potential function. Furthermore, the results suggested lncRNA Gm20743 may be involved in regulating mitochondrial function, oxidative stress, cell proliferation, and myotube differentiation in skeletal muscle cells. These findings significantly improve our understanding of lncRNAs that may mediate muscle mass, strength, and function in diabetes and represent potential therapeutic targets for diabetes-induced sarcopenia.

A novel circular RNA, circIgfbp2, links neural plasticity and anxiety through targeting mitochondrial dysfunction and oxidative stress-induced synapse dysfunction after traumatic brain injury.

Traumatic brain injury (TBI) can lead to different neurological and psychiatric disorders. Circular RNAs (circRNAs) are highly expressed in the nervous system and enriched in synapses; yet, the underlying role and mechanisms of circRNAs in neurological impairment and dysfunction are still not fully understood. In this study, we investigated the expression of circRNAs and their relation with neurological dysfunction after TBI. RNA-Seq was used to detect differentially expressed circRNAs in injured brain tissue, revealing that circIgfbp2 was significantly increased. Up-regulated hsa_circ_0058195, which was highly homologous to circIgfbp2, was further confirmed in the cerebral cortex specimens and serum samples of patients after TBI. Moreover, correlation analysis showed a positive correlation between hsa_circ_0058195 levels and the Self-Rating Anxiety Scale scores in these subjects. Furthermore, knockdown of circIgfbp2 in mice relieved anxiety-like behaviors and sleep disturbances induced by TBI. Knockdown of circIgfbp2 in H2O2 treated HT22 cells alleviated mitochondrial dysfunction, while its overexpression reversed the process. Mechanistically, we discovered that circIgfbp2 targets miR-370-3p to regulate BACH1, and down-regulating BACH1 alleviated mitochondrial dysfunction and oxidative stress-induced synapse dysfunction. In conclusion, inhibition of circIgfbp2 alleviated mitochondrial dysfunction and oxidative stress-induced synapse dysfunction after TBI through the miR-370-3p/BACH1/HO-1 axis. Thus, circIgfbp2 might be a novel therapeutic target for anxiety and sleep disorders after TBI.

Biogeographic distributions of microbial communities associated with anaerobic methane oxidation in the surface sediments of deep-sea cold seeps in the South China Sea.

Cold seeps are oasis for the microbes in the deep-sea ecosystems, and various cold seeps are located along the northern slope of the South China Sea (SCS). However, by far most microbial ecological studies were limited to specific cold seep in the SCS, and lack of comparison between different regions. Here, the surface sediments (0-4 cm) from the Site F/Haima cold seeps and the Xisha trough in the SCS were used to elucidate the biogeography of microbial communities, with particular interest in the typical functional groups involved in the anaerobic oxidation of methane (AOM) process. Distinct microbial clusters corresponding to the three sampling regions were formed, and significantly higher gene abundance of functional groups were present in the cold seeps than the trough. This biogeographical distribution could be explained by the geochemical characteristics of sediments, such as total nitrogen (TN), total phosphorus (TP), nitrate (NO3 -), total sulfur (TS) and carbon to nitrogen ratios (C/N). Phylogenetic analysis demonstrated that mcrA and pmoA genotypes were closely affiliated with those from wetland and mangroves, where denitrifying anaerobic methane oxidation (DAMO) process frequently occurred; and highly diversified dsrB genotypes were revealed as well. In addition, significantly higher relative abundance of NC10 group was found in the Xisha trough, suggesting that nitrite-dependent DAMO (N-DAMO) process was more important in the hydrate-bearing trough, although its potential ecological contribution to AOM deserves further investigation. Our study also further demonstrated the necessity of combining functional genes and 16S rRNA gene to obtain a comprehensive picture of the population shifts of natural microbial communities among different oceanic regions.

CircLphn3 protects the blood-brain barrier in traumatic brain injury.

Circular RNAs (circRNAs) are a new and large group of non-coding RNA molecules that are abundantly expressed in the central nervous system. However, very little is known about their roles in traumatic brain injury. In this study, we firstly screened differentially expressed circRNAs in normal and injured brain tissues of mice after traumatic brain injury. We found that the expression of circLphn3 was substantially decreased in mouse models of traumatic brain injury and in hemin-treated bEnd.3 (mouse brain cell line) cells. After overexpressing circLphn3 in bEnd.3 cells, the expression of the tight junction proteins, ZO-1, ZO-2, and occludin, was upregulated, and the expression of miR-185-5p was decreased. In bEnd.3 cells transfected with miR-185-5p mimics, the expression of ZO-1 was decreased. Dual-luciferase reporter assays showed that circLphn3 bound to miR-185-5p, and that miR-185-5p bound to ZO-1. Additionally, circLphn3 overexpression attenuated the hemin-induced high permeability of the in vitro bEnd.3 cell model of the blood-brain barrier, while miR-185-5p transfection increased the permeability. These findings suggest that circLphn3, as a molecular sponge of miR-185-5p, regulates tight junction proteins' expression after traumatic brain injury, and it thereby improves the permeability of the blood-brain barrier. This study was approved by the Animal Care and Use Committee of Chongqing Medical University of China (approval No. 2021-177) on March 22, 2021.

A novel mechanism linking ferroptosis and endoplasmic reticulum stress via the circPtpn14/miR-351-5p/5-LOX signaling in melatonin-mediated treatment of traumatic brain injury.

Traumatic brain injury (TBI) can lead to disability or devastating consequences with few established treatments. Although ferroptosis has been shown to be involved in TBI, the underlying mechanism was rarely known. Melatonin has been indicated to exhibit neuroprotective activities. However, the anti-ferroptotic effects of melatonin on TBI have not yet to be elucidated. We aimed to investigate whether ferroptosis was induced in humans after TBI and whether ferroptosis inhibition by melatonin could protect against blood-brain barrier (BBB) damage after TBI in vivo and in vitro. Circular RNAs (circRNAs) are highly expressed in the brain. For the first time, differentially expressed circRNA after melatonin treatment for TBI were detected by RNA sequencing. We found that lipid peroxidation was induced in humans after TBI, while melatonin significantly improved brain function of mice after TBI and alleviated ferroptosis and endoplasmic reticulum (ER) stress in vivo and in vitro. A total of 1826 differentially expressed circRNAs were found (fold change >2, Q < 0.01), including 921 down-regulated and 905 up-regulated circRNAs in the injured brain tissues of TBI mice receiving melatonin treatment. Mechanistically, melatonin administration reduced the level of circPtpn14 (mmu_circ_0000130), which functioned by acting as a miR-351-5p sponge to positively regulate the expression of the ferroptosis-related 5-lipoxygenase (5-LOX). Moreover, circPtpn14 overexpression partly abolished the inhibitory effects of melatonin on ferroptosis. Collectively, our findings provide the first evidence that melatonin could exert anti-ferroptotic and anti-ER stress effects in brain injury by alleviating lipid peroxidation via the circPtpn14/miR-351-5p/5-LOX signaling.

Geology, environment, and life in the deepest part of the world's oceans.

The hadal zone, mostly comprising of deep trenches and constituting of the deepest part of the world's oceans, represents the least explored habitat but one of the last frontiers on our planet. The present scientific understanding of the hadal environment is still relatively rudimentary, particularly in comparison with that of shallower marine environments. In the last 30 years, continuous efforts have been launched in deepening our knowledge regarding the ecology of the hadal trench. However, the geological and environmental processes that potentially affect the sedimentary, geochemical and biological processes in hadal trenches have received less attention. Here, we review recent advances in the geology, biology, and environment of hadal trenches and offer a perspective of the hadal science involved therein. For the first time, we release high-definition images taken by a new full-ocean-depth manned submersible Fendouzhe that reveal novel species with an unexpectedly high density, outcrops of mantle and basaltic rocks, and anthropogenic pollutants at the deepest point of the world's ocean. We advocate that the hydration of the hadal lithosphere is a driving force that influences a variety of sedimentary, geochemical, and biological processes in the hadal trench. Hadal lithosphere might host the Earth's deepest subsurface microbial ecosystem. Future research, combined with technological advances and international cooperation, should focus on establishing the intrinsic linkage of the geology, biology, and environment of the hadal trenches.

Deep seafloor plastics as the source and sink of organic pollutants in the northern South China Sea.

Large plastic litter (as opposed to microplastics and plastic pellets) could adsorb organic pollutants and thus pose a serious threat to the marine environment. We report high levels of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) adsorbed to plastic litter sampled from depths of 1800-3100 m in the Xisha Trough region of the northern South China Sea (NSCS). ∑PCBs on plastics ranged from 126.9-142.1 ng/g, with tri-PCBs accounting for 92-97% of the total PCB concentrations in all samples. Levels of ∑OCPs varied from 4280 to 5351 ng/g (average 4690 ng/g), with a total of 19 compounds detected in the seven samples. While no parent DDT (dichlorodiphenyltrichloroethane) was detected, op'-DDE (metabolite of DDT) was most abundant, with concentrations ranging from 947.5-1551.7 ng/g. ∑CHLs (heptachlor + heptachlor epoxide A + heptachlor epoxide B + cis-chlordane + trans-chlordane) ranged from 1083.1-1263.7 ng/g (mean 1153 ng/g) and accounted for 24% of ∑OCPs. Various compositional ratios of HCH (hexachlorocyclohexane) and DDT metabolites improved our understanding of the sources and transport pathways of OCPs. The total absence of DDT may be a "ghost indicator" of no recent DDT inputs into the oceans. There could well be inputs of DDT, but only as the degraded metabolites DDE and DDD when they are adsorbed to seafloor plastic litter. A comparison of HCH isomer ratios in seafloor plastics with technical HCH ratios revealed that HCHs were possibly not from early residues but from later inputs. An ecological risk assessment of the contaminants indicated a high risk from ∑DDTs, p,p-DDE, and γ-HCH in all the sampled locations. Finally, we propose a descriptive model depicting the movements and transportation of PCBs and OCPs from the ocean surface to seafloor plastics in the NSCS.

Association between diesel engine exhaust exposure and lung function in Australian gold miners.

Previous studies have reported that miners (and other workers) exposed to high levels of diesel engine exhaust (DEE) have an increased risk of lung function decline. The main objective of this study was to evaluate associations between exposure to different components associated with DEE in relation to lung function across a 12-h working shift. Eighty underground gold miners and twenty surface miners completed spirometry and questionnaires at the beginning and end of their 12 h work shift. Personal exposure to elemental carbon (EC), volatile organic compounds (VOCs), nitrogen dioxide (NO2), particle size and particle number were monitored during their shift. Multiple regression models were used to examine the associations between DEE and lung function, adjusting for a range of covariates. Underground miners were exposed to higher levels of EC, VOCs, NO2, and particle number and larger mean particle size than surface miners. Cross-shift reduction in Z-score value of FEV1/FVC in underground miners was statistically significantly greater than those of surface miners. The cross-shift change in Z-score value of FEV1/FVC was associated with exposure to higher concentration of EC and particle number, but not with VOCs, NO2 and particle size. Occupational exposure to diesel engine exhaust in current Australian gold mines is substantial. Exposures were higher in underground miners and had a negative association with their lung function over a single 12-h shift.

Measurement of urinary 1-aminopyrene and 1-hydroxypyrene as biomarkers of exposure to diesel particulate matter in gold miners.

Metabolites of polycyclic aromatic hydrocarbons measured in human samples are often used as biomarkers of exposure to diesel engine exhaust (DEE). The aim of this study was to assess the changes in urinary levels of 1-aminopyrene (1-AP) and 1-hydroxypyrene (1-OHP) and their relationship with Elemental Carbon (EC), as a component of diesel engine exhaust exposure, among a hard-rock gold-mining population. Urine samples were collected at the beginning and end of a 12-hour work shift from 100 underground and above ground gold miners. Miners were fitted with personal exposure monitoring equipment to quantify exposure to DEE, measured as Elemental Carbon (EC), across their 12-hour work shift. General linear regression assessed associations of the post-shift urinary 1-AP and 1-OHP concentrations with EC, controlling for age, gender, the pre-shift biomarker level, Body Mass Index (BMI), days on current shift, time in mining, smoking status and second-hand smoke exposure. The concentrations of 1-AP and 1-OHP increased significantly across a 12-hour mining work shift. Moreover, consistent with the sensitivity analysis, the concentration of 1-AP was significantly associated with EC after adjustments. Urinary 1-OHP, but not 1-AP was significantly associated with current smoking. Urinary 1-AP may be a more robust and specific biomarker of DEE than 1-OHP.

Depression and social support mediate the effect of HIV self-stigma on condom use intentions among Chinese HIV-infected men who have sex with men.

HIV self-stigma in HIV positive men who have sex with men (HIVMSM) has been identified as one of the largest challenges of HIV prevention, and associates with numerous negative outcomes, including depression, decreased social support, and less condom use intentions. In the present study, 321 HIVMSM in Chengdu, China were recruited to examine the prevalence of condom use in the past months and intentions to use condoms in next six months; we also identify pathways between HIV self-stigma and intentions to use condoms by the structural equation modeling approach. Results showed that Chinese HIVMSM had the suboptimal prevalence of consistent condom use and low intentions to use condoms consistently. Additionally, depression and decreased social support were significant mediators between HIV self-stigma and condom use intentions. The complex pathways between HIV self-stigma and intentions to use condoms should be taken into account in the HIV prevention and intervention programs.

Does Caesarean Section Affect Breastfeeding Practices in China? A Systematic Review and Meta-Analysis.

Objectives To ascertain the association between caesarean delivery and breastfeeding practices in China. Methods We conducted a systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and Meta-analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Electronic databases of CNKI, Medline, EMBASE, CINAHL, ProQuest and Science Direct were searched and screened to identify relevant articles from January 1990 to June 2015. Both fixed and random effect meta-analysis techniques were used to estimate the pooled effect size between caesarean delivery and breastfeeding outcomes at different time points. Sensitivity analysis and publication bias test were also conducted. Results Forty six studies were eligible for the qualitative synthesis of systematic review; among them, 27 studies were included for the meta-analysis. At the early postpartum period, the odds of exclusive breastfeeding after caesarean section was 47% (pooled OR 0.53, 95% CI 0.41, 0.68) lower than that after vaginal delivery. At 4 months postpartum, the odds of breastfeeding was similarly lower (pooled OR 0.61, 95% CI 0.53, 0.71) for caesarean mothers. Substantial heterogeneity among studies was detected for both breastfeeding outcomes. Subgroup analyses stratified by study design, time points of breastfeeding outcomes and definitions of breastfeeding all confirmed the negative association between caesarean section and breastfeeding prevalence. Conclusions In China, breastfeeding practices were affected adversely by caesarean delivery. Therefore, health policy to improve breastfeeding outcomes should take this into consideration.