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Exciting phenomena may emerge in non-centrosymmetric two-dimensional electronic systems when spin-orbit coupling (SOC)1 interplays dynamically with Coulomb interactions2,3, band topology4,5 and external modulating forces6-8. Here we report synergetic effects between SOC and the Stark effect in centrosymmetric few-layer black arsenic, which manifest as particle-hole asymmetric Rashba valley formation and exotic quantum Hall states that are reversibly controlled by electrostatic gating. The unusual findings are rooted in the puckering square lattice of black arsenic, in which heavy 4p orbitals form a Brillouin zone-centred Γ valley with pz symmetry, coexisting with doubly degenerate D valleys of px origin near the time-reversal-invariant momenta of the X points. When a perpendicular electric field breaks the structure inversion symmetry, strong Rashba SOC is activated for the px bands, which produces spin-valley-flavoured D± valleys paired by time-reversal symmetry, whereas Rashba splitting of the Γ valley is constrained by the pz symmetry. Intriguingly, the giant Stark effect shows the same px-orbital selectiveness, collectively shifting the valence band maximum of the D± Rashba valleys to exceed the Γ Rashba top. Such an orchestrating effect allows us to realize gate-tunable Rashba valley manipulations for two-dimensional hole gases, hallmarked by unconventional even-to-odd transitions in quantum Hall states due to the formation of a flavour-dependent Landau level spectrum. For two-dimensional electron gases, the quantization of the Γ Rashba valley is characterized by peculiar density-dependent transitions in the band topology from trivial parabolic pockets to helical Dirac fermions.

Tourism has been a major economic pillar in numerous cities. A sustainable tourism development is vital while residents’ support is the lynchpin of success. The current study examines if and how su...

A genome-directed discovery strategy to identify new tetrahydroisoquinolines (THIQs) was applied to deep-sea derived Streptomyces niveus SCSIO 3406; 11 THIQs were found representing three THIQ clas...

The general problem under consideration is the determination of the best (i.e., smallest) constant C p , q , r such that ‖ X Y − Y X ‖ p ≤ C p , q , r ‖ X ‖ q ‖ Y ‖ r for all n × n matrices X and Y , where ‖ ⋅ ‖ p is the Schatten p-norm. Among the open situations, the problem is solved when (i) 2 p ∞ , q = r = 1 ; (ii) 2 p ∞ , q = 1 , 1 r 2 , and X, Y are 2 × 2 real matrices. The result for (i) is obtained via the study of the region (recently obtained in [5] ) of singular values of the commutator X Y − Y X , where X and Y are normalized rank one matrices. As a result of independent interest, for 2 × 2 real matrices, the region of singular values of the commutator X Y − Y X , where X is rank one and normalized, and ‖ Y ‖ r = 1 , is determined. The result for (ii) is a consequence of the case when r lies between 1 and 2.

Published evidences have shown that autophagy plays an important role in silica-induced lung inflammation and collagen deposition. Our previous study found that the level of growth arrest-specific protein 6 (Gas6) in bronchoalveolar lavage fluid was increased after silica exposure. However, it is unclear whether Gas6 is involved in the regulation of silica-induced autophagy dysfunction. In this study, we observed an autophagosomes accumulation in wild-type C57BL/6 (WT) mice lung after silica intratracheal instillation and then investigated whether genetic loss of Gas6 (Gas6−/−) could ameliorate it. Our data showed that Gas6−/− mice exhibited a limited autophagosomes accumulation from days 7–84 after silica exposure, revealed by reduced induction and increased degradation of autophagosomes in mice lung tissue. Interestingly, silica particles could elevate the expression of Mer receptor, which was significantly decreased in Gas6−/− mice (P

1-bromopropane is a US Environmental Protection Agency-identified significant hazardous air pollutant with concerned adverse respiratory effect. We aimed to investigate the relationship between 1-bromopropane exposure and pulmonary function and the underlying role of oxidative damage, which all remain unknown. Pulmonary function and urinary biomarkers of 1-bromopropane exposure (N-Acetyl-S-(n-propyl)-L-cysteine, BPMA) and oxidative damage to DNA (8-hydroxy-deoxyguanosine, 8-OHdG) and lipid (8-iso-prostaglandin-F2α, 8-iso-PGF2α) were measured for 3259 Chinese urban adults from the Wuhan-Zhuhai cohort. The cross-sectional relationship of BPMA with pulmonary function and the joint relationship of BPMA and 8-OHdG or 8-iso-PGF2α with pulmonary function were investigated by linear mixed models. The mediating roles of 8-OHdG and 8-iso-PGF2α were evaluated by mediation analysis. Additionally, a panel of 138 subjects was randomly convened from the same cohort to evaluate the stability of BPMA repeatedly measured in urine samples collected over consecutive three days and intervals of one, two, and three years, and to estimate the longitudinal relationship of BPMA with pulmonary function change in three years. We found each 3-fold increase in BPMA was cross-sectionally related to FVC and FEV

Ambivalence is the simultaneous experience of positive and negative feelings toward a specific person. Recent research suggested ambivalence is negatively associated with psychological well-being, and this association was mainly driven by negative feelings and not affected by the presence of positive feelings. This paper questioned the assumption and aimed to examine the relationship between caregiving ambivalence and psychological well-being, by disaggregating the positive and negative components of ambivalence. The study comprised data from a cross-sectional questionnaire survey with 190 family caregivers of stroke survivors (56 ± 14.3 years old; 70% female) in Hong Kong. The positive feelings and negative feelings towards a care recipient were separately measured, and these two composite scores were used to create an indirect measure of ambivalence. Psychological well-being was measured by caregivers’ positive role appraisals and depressive symptoms. Hierarchical multiple regression showed that the positive feeling was associated with positive aspects of caregiving (β = 0.54, p

In every night of non-traffic hours, different jobs are conducting maintenance works in “Railway” trackside area. This project will explain a specific section of track under the sole control an Engineer’s Person-in-Charge as procedures. And how to provide protection methods by which a person or persons on or near a track are safeguarded from potential train movements or a train is safeguarded from other train movements or obstructions, or persons or equipment are safeguarded from traction power.Consolidated past several investigation reports and according to related is rules, workflow or procedures etc. to summarize. There are protection tools left on trackside area incident caused by the workers are forgetting and poor management. Proposed are different project themes in the light of their expertise, experience and observation in their daily works. The proposed themes are compared, assessed and prioritized under the criteria - “Manageable”, “Measurable”, “Result of Benefit”, “Standardization” and “Priority” in the Decision Matrix. Establish some solve problem methods for comparing to find out which that lower-cost plan accordingly. I came up with a conclusion and the ideas as develop a mobile application and create a unique QR code label with equipment naming to facilitate each worker management of protection tools. This is also fulfilled in popular terms of Creativity and Innovations. Used the MIT App Inventor (Massachusetts Institute of technology) an intuitive and visual programming preform for mobile application are development. Stage 1: program for individual mobile user application. Stage 2: build-up Network centralized storage with supervising console operation. Stage 3: testing system under with 5G network compatibility, bandwidth and network speed is applicable people will be able to use more of the network dedicated to each mobile phone.Finally, successful to apply trial works a fruitful outcome after implementation of the project solution. There was no missing of protection tools on trackside area within the trial period. With the safety-first culture boosted by us, I believe we can achieve a common goal: Everyone Going Home Safe and Well Every day.

BACKGROUND The Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) has been used to screen for dementia, but it has not been validated to delineate the stages of Alzheimer disease (AD). This study aimed to determine the cut-off score ranges for mild, moderate, and severe AD. METHODS The HK-MoCA score was matched against the Clinical Dementia Rating on 155 patients with AD. Investigators performing the HK-MoCA and Clinical Dementia Rating were blinded to each other. Receiver-operating characteristic analysis was used to determine the cut-off scores between different stages of AD (mild, moderate, and severe stage). A secondary analysis with adjustments for age and education received were also performed. RESULT The cut-off score in HK-MoCA was ≤4 for those with severe AD (sensitivity 84.4%, specificity 91.9%, area under curve=0.92, P

Background PEGylated granulocyte colony-stimulating factor (G-CSF) is a safe alternative to G-CSF to improve chemotherapy-induced neutropenia (CIN). This superiority has resulted in its increased use by physicians; however, the superiority of PEGylated G-CSF for CIN in breast cancer has not been conclusively determined. Objectives To assess the superiority of PEGylated G-CSF for CIN in breast cancer in terms of effectiveness and safety via a systematic review and meta-analysis. Methods A literature search in PubMed, Embase, Cochrane Library, and Web of Science was performed for eligible studies published from database inception to December 2019. All studies comparing PEGylated G-CSF and G-CSF for CIN of breast cancer were reviewed. After literature selection, data extraction and quality assessment were performed by two reviewers independently. Meta-analysis was conducted using Revman, version 5.2. Results Nine randomized controlled trials were finally identified. The publication bias of these studies was acceptable. For the endpoint of effectiveness, analysis of the incidence/duration of grade ≥ 3 neutropenia, the duration of grade 4 neutropenia, the incidence of febrile neutropenia (FN), and the time to absolute neutrophil count recovery showed no advantage of PEGylated G-CSF over G-CSF for CIN of breast cancer (P > 0.05), with the premise of a sufficient dose of G-CSF according to the guidelines. No significant differences in grade 4 adverse events were observed between the groups (P = 0.29), and PEGylated G-CSF did not increase the incidence of skeletal and/or muscle pain compared with G-CSF (P = 0.32). Conclusion PEGylated G-CSF was as effective and safe as G-CSF to reduce CIN in breast cancer but did not show an obvious superiority. However, in clinical practice, PEGylated G-CSF has an obvious advantage in terms of convenience, which could improve patient’s quality of life.

The new conservative treatment methods of female stress urinary incontinence mainly include laser therapy, magnetic stimulation therapy and stem cell therapy. Laser therapy and magnetic stimulation therapy can improve the urodynamic parameters, clinical symptoms, quality of life and sexual life of female stress urinary incontinence patients, with higher compliance and less side effects. Stem cell therapy can improve histological changes, urodynamic parameters of stress urinary incontinence rats, and clinical symptoms and quality of life of patients with stress urinary incontinence, but it has not been widely used in clinical practice, and the successful experience is mainly accumulated in the animal experiment stage. In order to make it easier for medical workers to understand and promote these three new conservative treatment methods, this article reviews the treatment principles and treatment effects of these new conservative treatment methods.

The region of singular values of the commutator XY − Y X for 2 × 2 rank one complex matrices X and Y is determined. This answers in affirmative a conjecture raised in [D. Wenzel. A strange phenomenon for the singular values of commutators with rank one matrices. Electron. J. Linear Algebra, 30:649–669, 2015.] when 2 × 2 matrices are concerned. The approach and proofs also lead to a complete relation between the singular values, eigenvalues and diagonal elements of the commutator under consideration.

In extremely low-temperature environments such as aerospace and polar regions, advanced elastic thermal insulation materials are urgently needed but their development is challenging, as traditional elastic insulators are completely “frozen”, lose elasticity and become brittle. Herein, we proposed a novel structural elastic strategy to create an ultralow-temperature elastic polymer aerogel with highly oriented thin nanosheets and hierarchically honeycomb-like architectures from low-cost raw materials. This approach endowed the polymer aerogel with superelasticity and high strength at liquid nitrogen temperature (−196 °C), where the aerogel can bear more than 10 000 times its weight and repeatedly recover to its original size after force removal. The underlying structural elastic mechanism was revealed by finite element simulation calculation. The resultant robust aerogel also displayed an excellent extreme-condition thermal insulation, which could maintain a pleasant interior environment with small temperature changes under harsh external environments from liquid nitrogen to fire scenarios. It combined the great features of ultralow-temperature superelasticity with high mechanical strength, excellent thermal insulation under extremely harsh conditions, fire retardancy, and performance stability. These results provide new insights and general methods for the development of advanced super-elastic polymeric insulators with high strength at ultralow temperatures.

Diatoms, accounting for 40% of the marine primary production and 20% of global carbon dioxide fixation, are threatened by the ongoing ocean warming (OW). However, whether and how these ecologically important phytoplankton adapt to OW remains poorly unknown. Here, we experimentally examined the metabolic adaptation of a globally important diatom species

The epidemiological advantage of Omicron variant is evidenced by its rapid spread and the ability to outcompete prior variants. Among Omicron sub-lineages, early outbreaks were dominated by BA.1 while BA.2 has gained dominance since February 2022. The relative pathogenicity and transmissibility of BA.1 and BA.2 have not been fully defined.We compared viral loads and clinical signs in Syrian hamsters after infection with BA.1, BA.2, or D614G variant. A competitive transmission model and next generation sequencing were used to compare the relative transmission potential of BA.1 and BA.2.BA.1 and BA.2 caused no apparent clinical signs while D614G caused more than 10% weight loss. Higher viral loads were detected from the nasal washes, nasal turbinate and lungs of BA.1 than BA.2 inoculated hamsters. No aerosol transmission was observed for BA.1 or BA.2 under the experimental condition that D614G transmitted efficiently. BA.1 and BA.2 were able to transmit among hamsters via direct contact; however, BA.1 transmitted more efficiently than BA.2 under the competitive transmission model. No recombination was detected from direct contacts exposed simultaneously to BA.1 and BA.2.Omicron BA.1 and BA.2 demonstrated attenuated pathogenicity and reduced transmission potential in hamsters when compared to early SARS-CoV-2 strains.

The effect of long-term PMTo investigate the effects of long-term personal PMPersonal PMThe medians of personal PMLong-term high PM

High storage capacity, high separation selectivity, and high structure stability are essential for an idea gas adsorbent. However, it is not easy to achieve all three at the same time, even for the promising metal-organic framework (MOF) adsorbents. We demonstrate herein that robust [Sc

Styrene and ethylbenzene (S/EB) are the monomers of polystyrene (PS) and polyethylene (PE), respectively, and have been identified as significant hazardous air pollutants by the U.S. Environmental Protection Agency. However, the adverse effects of S/EB on human health, especially cardiovascular health, have not been well established. Urinary biomarker of S/EB exposure and heart rate variability (HRV) were measured in urban adults from the Wuhan-Zhuhai cohort and were repeated after 3-year and 6-year follow-ups. Linear mixed models were used to estimate associations of S/EB exposure biomarker with HRV and longitudinal additional annual change of HRV. The mediating role of transforming growth factor (TGF)-β1 was tested by using mediation analysis. A total of 2842 general adults were included at baseline analysis, and 4748 observations were included in the repeated measurement study. In the cross-sectional analysis, each 1% increment in urinary S/EB exposure biomarker was significantly associated with a 0.106 % (95 % CI: -0.160, -0.052), 0.109 % (-0.169, -0.049), 0.099 % (-0.145, -0.053), 0.040 % (-0.060, -0.020), and 0.031 % (-0.054, -0.007) decrement in low frequency (LF), high frequency (HF), total power (TP), standard deviation of all normal-to-normal intervals (SDNN), and square root of the mean squared difference between adjacent normal-to-normal interval, respectively. Smoking status modified the relationships of urinary S/EB exposure biomarker with TP and SDNN. TGF-β1 mediated 3.09-5.16 % of the association between urinary S/EB biomarker and lower HRV. The follow-up analyses detected a negative association between urinary S/EB exposure biomarker and the additional annual change of LF (β: -0.016; 95 % CI: -0.028, -0.004), HF (-0.014; -0.026, -0.001), and TP (-0.011; -0.021, -0.001). Our findings demonstrated that S/EB exposure was associated with HRV reduction among the general urban adults and the TGF-β pathway may play a part of the mediating role in this association.

Due to the rise in bacterial resistance, the antibacterial extractions from Chinese herbs have been used more frequently for wound care. In this work, baicalin, an extraction from the Chinese herb Scutellaria baicalensis, was utilized as the antibacterial component in the poly(ε-caprolactone)/MXene (PCL/Ti3C2TX) hybrid nanofibrous membranes for wound dressing. The results revealed that the presence of Ti3C2TX aided in the diameter reduction of the electrospun nanofibers. The PCL hybrid membrane containing 3 wt% Ti3C2TX nanoflakes and 5 wt% baicalin exhibited the smallest mean diameter of 210 nm. Meanwhile, the antibacterial tests demonstrated that the PCL ternary hybrid nanofibers containing Ti3C2TX and baicalin exhibited adequate antibacterial activity against the Gram-positive bacterial S. aureus due to the good synergistic effects of Ti3C2TX naoflakes and baicalin. The addition of Ti3C2TX nanoflakes and baicalin could significantly improve the hydrophilicity of the membranes, resulting in the release of baicalin from the nanofibers. In addition, the cytotoxicity of the nanofibers on rat skeletal myoblast L6 cells confirmed their good compatibility with these PCL-based nanofibrous membrances. This work offers a feasible way to prepare antibacterial nanofibrous membranes using Chinese herb extraction for wound dressing applications.

The effect of caffeine exposure on children's health remains poorly understood. We aimed to characterize the associations of caffeine and caffeine metabolites with adiposity outcomes among children and adolescents. We performed cross-sectional analyses of 1,447 children and adolescents aged 6-19 years from the 2009-2014 National Health and Nutrition Examination Survey. The linear regression and weighted quantile sum (WQS) regression were used to explore the associations of urinary caffeine and 14 caffeine metabolites with adiposity outcomes, including body mass index (BMI) z-score, waist circumference (WC), obesity, and overweight. In linear regression models, compared with the participants who consumed low caffeine, higher BMI z-score, WC, and risks of obesity and overweight were more likely among those who consumed high caffeine (P 0.05). In WQS regression models, an interquartile range increase in the weighted caffeine index was significantly associated with increased BMI z-score (β = 0.10, 95% CI = 0.01, 0.17) and WC (β = 1.20, 95% CI = 0.31, 2.09), and risks of obesity (OR = 1.09, 95% CI = 1.02, 1.17). Totally, no modification effect of age or gender was observed in the linear regression model. Nonetheless, in WQS models, the positive associations of caffeine exposure with WC and risks of obesity and overweight were significant in children aged 6-11 years rather than 12-19 years. When stratified by gender, caffeine exposure was significantly associated with BMI z-score and WC in both boys and girls. These results add novel evidence that caffeine exposure might be associated with adverse adiposity outcomes among children and adolescents.

Arginase 1 (A1) is the enzyme that hydrolyzes the amino acid, L-arginine, to ornithine and urea. We have previously shown that A1 deletion worsens retinal ischemic injury, suggesting a protective role of A1. In this translational study, we aimed to study the utility of systemic pegylated A1 (PEG-A1, recombinant human arginase linked to polyethylene glycol) treatment in mouse models of acute retinal and brain injury. Cohorts of WT mice were subjected to retinal ischemia-reperfusion (IR) injury, traumatic optic neuropathy (TON) or brain cerebral ischemia via middle cerebral artery occlusion (MCAO) and treated with intraperitoneal injections of PEG-A1 or vehicle (PEG only). Drug penetration into retina and brain tissues was measured by western blotting and immunolabeling for PEG. Neuroprotection was measured in a blinded fashion by quantitation of NeuN (neuronal marker) immunolabeling of retina flat-mounts and brain infarct area using triphenyl tetrazolium chloride (TTC) staining. Furthermore, ex vivo retina explants and in vitro retina neuron cultures were subjected to oxygen-glucose deprivation (OGD) followed by reoxygenation (R) and treated with PEG-A1. PEG-A1 given systemically did not cross the intact blood-retina/brain barriers in sham controls but reached the retina and brain after injury. PEG-A1 provided neuroprotection after retinal IR injury, TON and cerebral ischemia. PEG-A1 treatment was also neuroprotective in retina explants subjected to OGD/R but did not improve survival in retinal neuronal cultures exposed to OGD/R. In summary, systemic PEG-A1 administration is neuroprotective and provides an excellent route to deliver the drug to the retina and the brain after acute injury.

The flavoprotein monooxygenase (FPMO) TerC is encoded by all known cyclopentene biosynthetic gene clusters. It can catalyze oxidative dearomatization toward a series of 6-HM analogues and further induces different skeletal distortions to form either benzoquinone or pyrone by bimodal reaction cascades, which is only governed by the C7 substitutions. Beyond our study demonstrated bimodal reaction cascades and advanced the biosynthetic knowledge of fungal cyclopentenes, this work also sets the stage for the bioengineering of 6-HM polyketides.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein is the main target for neutralizing antibodies. These antibodies can be elicited through immunization or passively transferred as therapeutics in the form of convalescent-phase sera or monoclonal antibodies (MAbs). Potently neutralizing antibodies are expected to confer protection; however, it is unclear whether weakly neutralizing antibodies contribute to protection. Also, their mechanism of action in vivo is incompletely understood. Here, we demonstrate that 2B04, an antibody with an ultrapotent neutralizing activity (50% inhibitory concentration [IC50] of 0.04 µg/ml), protects hamsters against SARS-CoV-2 in a prophylactic and therapeutic infection model. Protection is associated with reduced weight loss and viral loads in nasal turbinates and lungs after challenge. MAb 2B04 also blocked aerosol transmission of the virus to naive contacts. We next examined three additional MAbs (2C02, 2C03, and 2E06), recognizing distinct epitopes within the receptor binding domain of spike protein that possess either minimal (2C02 and 2E06, IC50 > 20 µg/ml) or weak (2C03, IC50 of 5 µg/ml) virus neutralization capacity in vitro. Only 2C03 protected Syrian hamsters from weight loss and reduced lung viral load after SARS-CoV-2 infection. Finally, we demonstrated that Fc-Fc receptor interactions were not required for protection when 2B04 and 2C03 were administered prophylactically. These findings inform the mechanism of protection and support the rational development of antibody-mediated protection against SARS-CoV-2 infections. IMPORTANCE The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by SARS-CoV-2, has resulted in the loss of millions of lives. Safe and effective vaccines are considered the ultimate remedy for the global social and economic disruption caused by the pandemic. However, a thorough understanding of the immune correlates of protection against this virus is lacking. Here, we characterized four different monoclonal antibodies and evaluated their ability to prevent or treat SARS-CoV-2 infection in Syrian hamsters. These antibodies varied in their ability to neutralize the virus in vitro. Prophylactic administration of potent and weakly neutralizing antibodies protected against SARS-CoV-2 infection, and this effect was Fc receptor independent. The potent neutralizing antibody also had therapeutic efficacy and eliminated onward aerosol transmission. In contrast, minimally neutralizing antibodies provided no protection against infection with SARS-CoV-2 in Syrian hamsters. Combined, these studies highlight the significance of weakly neutralizing antibodies in the protection against SARS-CoV-2 infection and associated disease.

Ecological stoichiometry is useful for revealing the biogeochemical characteristics of flows of nutrients and energy between plant and soil, as well as the important implications behind these ecological phenomena. However, the ecological stoichiometric linkages among leaf, litter, soil, and enzymes in the natural forests of the Loess Plateau remain largely unknown. Here, leaf, litter, and soil samples were collected from four age classes of natural Pinus tabuliformis Carr. (P. tabuliformis) to explore the deep linkages among these components. We measured the total carbon (C), total nitrogen (N), and total phosphorus (P) concentrations of leaf and litter, as well as the concentrations of soil organic C, total N, total P, nitrate N, ammonium N, available P, and the activities of β-1,4-glucosidase (a C-acquiring enzyme), β-1,4-N-acetylglucosidase (an N-acquiring enzyme), and alkaline phosphatase (a P-acquiring enzyme) in the topsoil (0–20 cm). The average leaf N:P was 6.9 indicated the growth of P. tabuliformis was constrained by N according to the relative resorption theory of nutrient limitation. The C:N, C:P, and N:P ratios in leaf, litter, and soil and the enzyme activity were not significantly different among age classes (p > 0.05). Litter C:N (43.3) was closer to the ratio of leaf C:N (48.8), whereas the litter C:P (257.7) was obviously lower than the ratio of leaf C:P (338.15). We calculated the stoichiometric homeostasis index (1/H) of leaf responses to soil elements and enzyme activities and found that the relationship between leaf C:P and soil C:P was homeostatic (p < 0.05), whereas the remaining indices showed the leaf stoichiometries were strictly homeostatic (p > 0.05). Correlation analysis showed both litter C:P and N:P were positively correlated with leaf and soil C:P, while the stoichiometric ratios of soil elements and enzymes were obviously irrelevant with leaf stoichiometries (p > 0.05). Partial least squares path modeling indicated that litter significantly changed soil element and enzyme characteristics through direct and indirect effects, respectively. However, soil elements and enzymes impacted leaf stoichiometries barely, which was further confirmed by an overall redundancy analysis. In summary, C:N:P stoichiometry within the plant–soil continuum revealed that natural P. tabuliformis is a relatively stable ecosystem in the Loess Plateau, where the element exchanges between plant and soil maintain dynamic balance with forest development. Further studies are needed to capture the critical factors that regulate leaf stoichiometry in the soil system.

The adverse effects of polycyclic aromatic hydrocarbon (PAHs), a group of common environmental pollutants, on mental health are unclear. This study is developed to evaluate the potential association of urinary PAH metabolites with depression in US adults.Measurement of 8 urinary PAH metabolites and assessment of depression were available for 9625 adults in the National Health and Nutritional Examination Survey 2005-2016. Multiple logistic regression models and weighted quantile sum (WQS) regression models were applied to evaluate the association between urinary PAH metabolites and depression.Among 9625 individuals with a weighted geometric mean age of 42.63 years, 801 participants suffered from depression. Significant positive dose-response relationships were observed between specific urinary PAH metabolites and the risk of depression after adjusting for potential confounders. Urinary 1-hydroxynaphthalene was positively and dose-dependently associated with the risk of depression among total participants (odds ratio: 1.188; 95% confidence interval: 1.096-1.288). In addition, each 1-unit increase of ln-transformed urinary 1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 23-hydroxyphenanthrene, 1-hydroxypyrene, and total PAH metabolites was associated with a 23.3%, 32.6%, 23.3%, 29.4%, 30.8%, 22.8%, 29.4%, and 31.7% increment in the risk of depression in smokers, respectively (all P and PExposure to PAHs may elevate the risk of depression among US adults. More studies are warranted to investigate the underlying mechanism by which PAHs induce the development of depression.