Meteorological impacts on the unexpected ozone pollution in coastal cities of China during the unprecedented hot summer of 2022.

Surface ozone pollution under climate warming has become a serious environmental issue. In the summer of 2022, abnormal warming spread over most of the Northern Hemisphere and resulted in the abnormal increase in O3 concentrations. In this study, we focused on the coastal cities in China and investigated the O3 trends in July during 2015 to 2022. Four regions with different locations and emission levels were selected for comparison. A significant increase of O3 concentration in July 2022 were observed in the southern coastal cities (16.7-22.8 µg m-3) while the opposite characteristics were found in the northern coastal cities (decrease of 0.26-2.18 µg m-3). The results indicated various distribution patterns of the O3 concentrations responded to heat wave across China. The weakening of East Asian summer monsoon, extension of the western Pacific subtropical high, significant warming, stronger solar radiation, lower relative humidity, less rainfall and sinking motion of atmosphere in 2022 were beneficial for O3 generation and accumulation in the southern coastal areas. Meteorological changes in July 2022 could lead to an increase of 15.6 % in O3 concentrations in southern coastal cities compared to that in 2015-2021, based on the analysis of machine learning. Air temperature was the main contributor to high O3 concentrations in the coast of Fujian province, while other coastal cities depended on relative humidity. This study indicated the challenge of O3 pollution control in coastal areas under global warming, especially in extreme heat wave events.

Boosted elimination of florfenicol by BiOClxBr1-x solid solutions via photocatalytic ozonation under visible light.

In this work, a series of BiOClxBr1-x (BCB) solid solutions are facilely designed for visible-light-driven photocatalytic ozonation (PCO) degradation of florfenicol (FF) in water environments, which could add to the library of efficient, cost-effective and robust nanocatalysts for water purification. BCB solid solutions in the structure of 2D nanosheets are achieved involving the etching of BiOBr "micro-flowers" with HCl at different concentrations, allowing a removal ratio of FF up to 97.3 % within 1 h, superior to bare BiOBr and bare BiOCl. A strengthened synergistic effect between photocatalysis and ozonation is substantiated, where the separation of photo-induced charge transfer is accelerated, the band gap is tuned and the utilization efficiency of ozone is enhanced. This facilitates the production of reactive oxygen species identified as •OH, •O2-, and 1O2 that will attack the FF molecule for degradation based on three pathways.

New Insights on the Formation of Nucleation Mode Particles in a Coastal City Based on a Machine Learning Approach.

Atmospheric particles have profound implications for the global climate and human health. Among them, ultrafine particles dominate in terms of the number concentration and exhibit enhanced toxic effects as a result of their large total surface area. Therefore, understanding the driving factors behind ultrafine particle behavior is crucial. Machine learning (ML) provides a promising approach for handling complex relationships. In this study, three ML models were constructed on the basis of field observations to simulate the particle number concentration of nucleation mode (PNCN). All three models exhibited robust PNCN reproduction (R2 > 0.80), with the random forest (RF) model excelling on the test data (R2 = 0.89). Multiple methods of feature importance analysis revealed that ultraviolet (UV), H2SO4, low-volatility oxygenated organic molecules (LOOMs), temperature, and O3 were the primary factors influencing PNCN. Bivariate partial dependency plots (PDPs) indicated that during nighttime and overcast conditions, the presence of H2SO4 and LOOMs may play a crucial role in influencing PNCN. Additionally, integrating additional detailed information related to emissions or meteorology would further enhance the model performance. This pilot study shows that ML can be a novel approach for simulating atmospheric pollutants and contributes to a better understanding of the formation and growth mechanisms of nucleation mode particles.

Sources appointment and health risks of PM2.5-bound trace elements in a coastal city of southeastern China.

To gain a comprehensive understanding of sources and health risks of trace elements in an area of China with high population densities and low PM2.5 concentrations, 15 trace elements (Al, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Sn, Ba, Pb) in PM2.5 were monitored from December 2020 to November 2021 in a representative city, Xiamen. The concentrations of trace elements in Xiamen displayed an obvious seasonal variation and were dominated by K, Fe, Al, Ca and Zn. Based on Positive Matrix Factorization analysis, source appointment revealed that the major sources of trace elements in Xiamen were traffic, dust, biomass and firework combustion, industrial manufacture and shipping emission. According to health risk assessment combined with the source appointment results, it indicated that the average noncarcinogenic risk was below the threshold and cancer risk of four hazardous metals (Cr, Ni, As, Pb) exceeded the threshold (10-6). Traffic-related source had almost half amount of contribution to the health risk induced by PM2.5-bound trace elements. During the dust transport period or Spring Festival period, the health risks exceeded an acceptable threshold even an order of magnitude higher, suggesting that the serious health risks still existed in low PM2.5 environment at certain times. Health risk assessment reminded that the health risk reduction in PM2.5 at southeastern China should prioritize traffic-related hazardous trace elements and highlighted the importance of controlling vehicles emissions in the future.

How well did the consensus methods apply in the guideline development of traditional Chinese medicine: a web-based survey in China.

BACKGROUND AND OBJECTIVE: Consensus methods are crucial in developing clinical guidelines. Different methods, such as the Delphi and nominal group techniques, are commonly used, but there is a lack of detailed instructions on how to implement them effectively. The survey aims to explore the opinions and attitudes of the chair, panel and working group on the critical elements of the consensus methods during guideline development. METHODS: We used a cross-sectional design to conduct this study and sent a structured questionnaire to stakeholders, including the chair, panel members, and working group participants, through the popular mobile phone application WeChat.We selected participants using a combination of purposive and snowball sampling. The questionnaire gathered information on demographics, experiences, opinions, and concerns regarding consensus methods and guideline development. RESULTS: The sample comprised 290 participants representing 31 provinces or municipalities. Among them, the most significant number of respondents (n = 107, 36.9%) were from Beijing. Most participants, specifically 211 (72.76%), held senior professional titles, while 186 (64.14%) adhered to ongoing guidelines. The Delphi method was the most commonly used consensus method (n = 132, 42.31%), but the respondents had only a preliminary understanding of it (n = 147, 47.12%). The consensus process also revealed the insufficiency of involving pharmacoeconomists, patients, and nurses. CONCLUSIONS: Consensus methods have to be standardised and used consistently in the guideline development process. The findings of this study offer insights into diverse roles and more effective ways to apply the consensus process during guideline development.

Molecular Composition of Anthropogenic Oxygenated Organic Molecules and Their Contribution to Organic Aerosol in a Coastal City.

Organic aerosols (OA) have gained attention as a substantial component of atmospheric aerosols owing to their impact on atmospheric visibility, climate, and human health. Although oxygenated organic molecules (OOMs) are essential contributors to OA formation, the sources, transformations, and fates of the OOMs are not fully understood. Herein, anthropogenic OOMs (AOOMs), anthropogenic volatile organic compounds (AVOCs), and OA were concurrently measured in Xiamen, a coastal city in southeastern China. Our results show that the AOOMs exhibited a high nitrogen content (76%) and a low oxidation degree. Strong photochemical processes of aromatic VOCs were the predominant sources of AOOMs. Also, NOx concentrations and the occurrence of multigeneration OH radical oxidations were the critical factors that might influence the formation of AOOMs. Finally, the newly developed aerosol dynamic model's results show that more than 35% of the OA mass growth rate is attributed to the gas-particle partitioning of AOOMs. Further sensitivity testing demonstrates that the contribution of AOOMs to OA growth is significantly enhanced during high-particulate-concentration periods, especially under low-temperature conditions. This study emphasizes the vital role of photochemically produced AOOMs derived from AVOCs in OA growth in a coastal urban atmosphere.

Preparation of SERS base membrane with cellulose compound dopamine and determination of hypochlorite.

Flexible silver substrates were made by in situ reduction of silver nanoparticles in bacterial cellulose membranes using the unique advantage of dopamine. Subsequently, we modified the substrate with 4-mercaptophenol (4-MP), a molecule capable of specifically recognizing ClO-, and its corresponding SERS signal changes with the concentration of hypochlorite, thus allowing the quantitative detection of ClO- content. The method showed a negative linear correlation (R2 = 0.9567) with the SERS intensity at 1077 cm-1 over the concentration range 0.5-100 µM, and the detection limit was 0.15 µM. The RSD of the SERS intensity at 1077 cm-1 under five batches was 4.2%, which proved the good reproducibility of P-BCM-Ag NP-MP. Finally, the P-BCM-Ag NPs were used for the detection of hypochlorite in cell contents, artificial urine, and clinical serum samples, utilizing spike experiments in all three environments. The recoveries were in the range 90-110% indicating the accuracy of the method for the detection of hypochlorite and validating the promising application of this assay for practical detection in intricate biological samples.

The Effect of Internet-Based Cognitive Behavioral Therapy on Major Depressive Disorder: Randomized Controlled Trial.

BACKGROUND: Many people living with major depressive disorder (MDD) in China do not receive treatment owing to a lack of mental health services, along with significant stigma toward mental illness. Internet-based cognitive behavioral therapy (ICBT) has been proposed to increase access to mental health care for people with MDD. OBJECTIVE: The aims of this study were to (1) evaluate the efficacy of ICBT for depressive symptoms in patients with MDD; (2) evaluate the effect of ICBT on anxiety symptoms, nonspecific psychological distress, general self-efficacy, depression stigma, social function, and health-related quality of life (HRQoL); and (3) explore the acceptability of and satisfaction with the ICBT program among participants. METHODS: Patients with MDD were enrolled and randomized to the ICBT group or the waiting-list control (WLC) group. The ICBT group received ICBT delivered through a WeChat mini-program with general support by nonspecialists. Participants in the 2 groups were self-evaluated online at baseline and posttreatment for changes in the primary outcome (ie, depressive symptoms) and secondary outcomes (ie, anxiety symptoms, nonspecific psychological distress, general self-efficacy, depression stigma, social functional impairment, and HRQoL). Changes in outcomes were measured by changes in overall scores on respective scales, and response and remission rates were calculated based on depressive symptoms. The acceptability of and satisfaction with the ICBT program were measured by treatment adherence and participants' feelings (ie, modules seriously completed, perceived benefit, and satisfaction). RESULTS: We included 40 patients who were randomly assigned to the ICBT group and 44 who were assigned to the WLC group. Compared with the WLC group, the ICBT group had fewer depressive symptoms, fewer anxiety symptoms, less nonspecific psychological distress, and greater general self-efficacy. Moreover, the ICBT group had higher response (18/31, 58%) and remission rates (17/31, 55%). The adherence rate in the ICBT group was 78% (31/40), and the majority of participants who completed all ICBT modules were satisfied with the ICBT program. CONCLUSIONS: ICBT demonstrated greater improvements in depressive symptoms, anxiety symptoms, nonspecific psychological distress, and general self-efficacy among selected patients with MDD in comparison with the findings in waiting-list controls. The ICBT program in this study had good acceptability and satisfaction among participants. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100046425); https://tinyurl.com/bdcrj4zv.

Photochemistry in the urban agglomeration along the coastline of southeastern China: Pollution mechanism and control implication.

The concentrations of ground-level ozone (O3) in China have undergone a rapid increase in recent years, resulting in adverse impacts on the air quality and climate change. However, limited research has been conducted on the coastal urban agglomerations with increasingly serious O3 pollution. Therefore, in order to better understand in situ photochemistry, comprehensive field observations of O3 and its precursors, coupled with the model simulation, were conducted in autumn of 2019 at six sites in an urban agglomeration along the coastline of southeastern China. Results indicated that O3 pollution in the southern part of the urban agglomeration was more severe than that in the northern part, due to higher levels of O3 precursors and stronger atmospheric oxidation capacity (AOC) in the southern regions. Oxygenated volatile organic compounds (OVOCs), NO2, and CO dominated the total OH reactivity, and the site-average daytime Ox (O3 + NO2) increments correlated well (R2 = 0.94) with the total OH reactivity of CO and VOCs at these sites except for Quanzhou, where industrial emissions (35.1 %) and solvent usages (33.7 %) dominated the VOC sources. However, vehicle exhausts (31.1 %) were the most predominant contributors to the VOC sources at other sites. The results of model simulations showed that net O3 formation rates were larger at the southern sites. Furthermore, O3 production was mainly controlled by VOCs at most sites, but co-limited by VOCs and NOx at Quanzhou. The most significant VOC groups contributing to O3 formation were aromatics and alkenes, with m/p-xylene, toluene, propene, and ethene being the main contributors at these sites. This study offers a more comprehensive understanding of the characteristics and formation of photochemical pollutions on the scale of the urban areas, indicating the critical need to reduce VOC emissions as a means of mitigating their photochemical effects.

The effect of nitrous acid (HONO) on ozone formation during pollution episodes in southeastern China: Results from model improvement and mechanism insights.

Two ozone (O3) processes, summer episode dominated by local production and autumn episode dominated by regional transport, were chosen to investigate the role of HONO in different pollution processes. Meteorological conditions, diurnal variation of O3, potential source contribution factor (PSCF) analysis, concentration weighted trajectory (CWT) models, and the distribution of the eight-hour maximum values of O3 on mainland China all prove that summer O3 was mainly locally generated while autumn O3 episode was more susceptible to regional transport. The gaps between observations and simulation results with the default HONO chemistry in Master Chemical Mechanism (MCM) of Observation Based Model (OBM) were higher in summer episode (0.58 ppb) than autumn episode (0.37 ppb). Although we implemented nine additional sources in the model to revise the HONO chemistry, the simulated values were still lower than the observed values. HONO promoted O3 production by accelerating the reaction of HO2 + NO and RO2 + NO, and promoted loss of O3 by the reaction of OH + NO2 and RO2 + NO2. The net production rate of O3 with HONO constraint increased by 28.50 % in summer and 22.43 % in autumn, which also indicated that HONO played more important role in the O3 production in summer. The difference of NOx of daily RIR between the cases with and without HONO constraint was higher in summer O3 episode (0.15 %/%) than that in autumn O3 episode (0.09 %/%), the same as to VOCs with -0.20 %/% in summer O3 episode and - 0.14 %/% in autumn O3 episode, which indicated that the presence or absence of the HONO constraint has a greater impact on the RIR value in the case of dominant local generation. In brief, the O3 sensitivity would be more favorable for VOCs without HONO constrained in the model, which would inevitably mislead policy makers to develop efficient policies to control O3 pollution.

Cost-Effectiveness Analysis of Relmacabtagene Autoleucel for Relapsed or Refractory Large B-Cell Lymphoma in China.

OBJECTIVES: Relmacabtagene autoleucel (relma-cel) was recently approved in China for treating relapsed or refractory large B-cell lymphoma (r/r LBCL). We conducted a cost-effectiveness analysis from the perspective of Chinese healthcare system. METHODS: A mixture-cure model was developed to project life-years (LYs), quality-adjusted LYs (QALYs), and overall direct cost with a lifetime horizon for patients with r/r LBCL treated with relma-cel versus salvage chemotherapy. Patient-level data from RELIANCE trial and published data from Collaborative Trial in Relapsed Aggressive Lymphoma extension study were used to inform the model. The incremental cost-effectiveness ratio (ICER) was estimated and cost-effectiveness was evaluated at the willingness-to-pay threshold of 3 times the national gross domestic product per capita. RESULTS: The model projected that treatment with relma-cel was associated with incremental gains of 5.11 LYs and 5.26 QALYs compared with salvage chemotherapy at an increased cost of ¥1 067 430 (∼$154 152), resulting in an ICER of ¥203 137 (∼$29 435) per QALY. The model was most sensitive to the uncertainty around the estimated cure rate. The ICER of relma-cel was within the willingness-to-pay threshold in the base case and the probability of relma-cel treatment being considered cost-effective was approximately 74%. CONCLUSIONS: Compared with salvage chemotherapy, treatment with relma-cel for r/r LBCL in patients who have failed at least 2 lines of systemic therapy is within the cost-effective range from the perspective of Chinese healthcare system and represents a good use of healthcare resources.

Highly sensitive detection of thyroglobulin based on sandwich-type electrochemical immunoassay.

As a dimeric protein, thyroglobulin (Tg) is an important biomarker for different thyroid cancer (DTC), so designing effective method to detect Tg is of great significance. In this work, by preparing ß-cyclodextrin (CD) functionalized carbon nanotubes (CNTs) nanohybrid (CD-CNTs) as carrier to immobilize primary antibody (Ab1) of Tg, assembling sulfydryl ferrocene (Fc) and secondary antibody (Ab2) on the surface of nanogold (Au) as signaling amplifier (Ab2-Au-Fc), a simple and sensitive sandwich-type electrochemical immunoassay (STEM) of Tg was designed herein for the first time. In brief, CNTs show large surface area and conductivity, while CD offers superior host-guest recognition capability that can bound with Ab1; meanwhile, Fc probe can offer stable electrochemical signal that is proportionable to the concentration of Tg. Under the optimum conditions, the proposed STEM platform shows excellent sensing results for Tg detection: a considerable low analytical detection (0.5 ng mL-1) and wide linearity (2 to 200 ng mL-1), suggesting the designed STEM platform offers potential real applications for detect Tg.

Mitochondrial DNA abnormalities and metabolic syndrome.

Metabolic syndrome (MetS) is a complex pathological condition that involves disrupted carbohydrate, protein, and fat metabolism in the human body, and is a major risk factor for several chronic diseases, including diabetes, cardiovascular disease, and cerebrovascular disease. While the exact pathogenesis of metabolic syndrome is not yet fully understood, there is increasing evidence linking mitochondrial dysfunction, which is closely related to the mitochondrial genome and mitochondrial dynamics, to the development of this condition. Recent advancements in genetic sequencing technologies have allowed for more accurate detection of mtDNA mutations and other mitochondrial abnormalities, leading to earlier diagnosis and intervention in patients with metabolic syndrome. Additionally, the identification of specific mechanisms by which reduced mtDNA copy number and gene mutations, as well as abnormalities in mtDNA-encoded proteins and mitochondrial dynamics, contribute to metabolic syndrome may promote the development of novel therapeutic targets and interventions, such as the restoration of mitochondrial function through the targeting of specific mitochondrial defects. Additionally, advancements in genetic sequencing technologies may allow for more accurate detection of mtDNA mutations and other mitochondrial abnormalities, leading to earlier diagnosis and intervention in patients with MetS. Therefore, strategies to promote the restoration of mitochondrial function by addressing these defects may offer new options for treating MetS. This review provides an overview of the research progress and significance of mitochondrial genome and mitochondrial dynamics in MetS.

PBDEs disrupt homeostasis maintenance and regeneration of planarians due to DNA damage, proliferation and apoptosis anomaly.

Polybrominated diphenyl ethers (PBDEs) are widely used as brominated flame retardants in the manufacturing industry, belonging to persistent organic pollutants in the environment. Planarians are the freshwater worms, with strong regenerative ability and extreme sensitivity to environmental toxicants. This study aimed to evaluate the potential acute comprehensive effects of PBDE-47/-209 on freshwater planarians. Methods to detect the effects include: detection of oxidative stress, observation of morphology and histology, detection of DNA fragmentation, and detection of cell proliferation and apoptosis. In the PBDE-47 treatment group, planarians showed increased oxidative stress intensity, severe tissue damage, increased DNA fragmentation level, and increased cell proliferation and apoptosis. In the PBDE-209 treatment group, planarians showed decreased oxidative stress intensity, slight tissue damage, almost unchanged DNA fragmentation level and apoptosis, proliferation increased only on the first day after treatment. In conclusion, both PBDE-47 and PBDE-209 are dangerous environmental hazardous material that can disrupt planarians homeostasis, while the toxicity of PBDE-47 is sever than PBDE-209 that PBDE-47 can lead to the death of planarians.

A Pilot Study on the Concentration, Distribution and Bioaccumulation of Polybrominated Diphenyl Ethers (PBDEs) in Tissues and Organs of Grassland Sheep.

Polybrominated diphenyl ether (PBDE) concentrations in various tissues and organs of grassland sheep from Inner Mongolia, China, were determined. The abilities of PBDEs binding to ovine serum albumin (OSA) and Cytochrome P450 enzyme (CYP3A24) were assessed by fluorescence spectroscopy and molecular docking simulations. The PBDE concentrations in the sheep tissue and organ samples were 33.4-167 pg/g dw. The distribution of PBDEs in sheep organs and tissues is affected not only by the function of organs and tissues, but also by the characteristics of PBDEs. Adipose tissue tends to bioaccumulate more-brominated BDEs (BDE-154, -153, and -183), but muscle tissues and visceral organs mainly bioaccumulate less-brominated BDEs. The distribution of PBDEs in visceral organs is mainly affected by the transport of ovine serum albumin (OSA) and the metabolism of CYP3A24 enzyme. The distribution of PBDEs in adipose tissue and brain is mainly affected by their logKOW.

One-pot synthesis of copper nanocluster/Tb-MOF composites for the ratiometric fluorescence detection of Cu2.

The increasing degradation of ecosystems due to heavy metal residues has led to environment and food contamination, prompting the development of convenient platforms for monitoring heavy metals. Here, a new dual-emission fluorescent sensor CuNCs@Tb@UiO-66-(COOH)2 for the detection of copper ions (Cu2+ ) has been synthesized using one-pot encapsulation of Tb(III) and glutathione-stabilized copper nanoclusters (CuNCs) into metal-organic frameworks (MOFs) UiO-66-(COOH)2 . In this ratiometric sensor, the fluorescence intensity of Tb3+ decreased significantly upon the addition of Cu2+ , whereas that of CuNCs showed good stability, together with an apparent colour change. Therefore, ratiometric fluorescence detection of Cu2+ can be accomplished by measuring the ratio of the fluorescence intensity at the 450 nm (F450 ) wavelength of CuNCs to the 548 nm (F548 ) emission of Tb3+ in the fluorescence spectra of the CuNCs@Tb@UiO-66-(COOH)2 suspension. Moreover, the obtained fluorescent probe showed good results in the detection of actual samples. This work can provide the basis of method for the exploration of ratiometric fluorescence and visual sensors of trace pollutants analysis in complicated samples.

A "bottle-around-ship" method to encapsulated carbon nitride and CdTe quantum dots in ZIF-8 as the dual emission fluorescent probe for detection of mercury (II) ion.

A facile and efficient "bottle-around-ship" approach for preparing the ratiometric fluorescent probe has been developed by encapsulating the red-colored fluorescence CdTe quantum dots (QDs) and blue-colored fluorescence graphitic carbon nitride quantum dots (g-CNQDs) into the zeolitic imidazolate metal-organic frameworks (ZIF-8) in one step. At a single excitation of 360 nm, the obtained probe ZIF-8@g-CNQD/CdTe shows the dual-emission peaked at 450 and 633 nm, respectively. The red emission of CdTe QDs is selectively quenched by the Hg2+, whereas the blue fluorescence of g-CNQDs as an internal reference is insensitive, resulting in an apparent color transformation from pink to blue for special recognition of Hg2+. By this approach, the relative fluorescence intensity ratio (F633/F450) decreased linearly with increasing Hg2+ concentration in the 0.2-3.5 µM range with a low limit of detection (LOD) of ~ 46 nM. Therefore, we demonstrate that this "bottle-around-ship" process provides a new strategy for the construction of ratiometric fluorescent Hg2+ probes with good simplicity, high efficiency, and excellent stabilities. Moreover, the obtained Hg2+ fluorescent probe shows good results in the detection of actual samples.

Perfluorooctanesulfonic acid exposure altered hypothalamic metabolism and disturbed male fecundity.

Previous studies have examined the effects of perfluorooctanesulfonic acid (PFOS) on disruption of the blood-testis barrier and spermatogenesis. Sertoli and Leydig cells were perturbed, resulting in a decrease in testosterone levels and sperm counts. However, the effects of PFOS on male fecundity are not limited to the testes. In this study, we demonstrated that oral PFOS exposure (1 µg/g BW and 5 µg/g BW) decreased the function of the Luteinizing hormone (LH)/Luteinizing hormone receptor (LHr) and decreased epididymal sperm motility. Consistently, testicular transcriptome analysis revealed that PFOS altered the expression of a cluster of genes associated with sperm motility and steroidogenesis. In mice exposed to PFOS, c-Fos immunostaining showed activation of the lateral septal nucleus (LS), paraventricular thalamus (PVT), locus coeruleus (LC), which are known to be related to anxiety-like behaviors. Metabolomic analyses of the hypothalamus revealed that exposure to PFOS perturbed the translation of proteins, as well as the biosynthesis of neurotransmitters and neuromodulators. Altogether, the activation of brain nuclei, shift of hypothalamic metabolome, and reduction of LH/LHr circuit resulted from PFOS exposure suggested the toxicant's systematic effects on male reproduction.

Gender differences in the association of sexual orientation with depressive symptoms: A national cross-sectional study among Chinese college students.

BACKGROUND: Depressive symptoms among the lesbian, gay, bisexual (LGB) in college students have generated worldwide concern in recent decades. This study aimed to estimate the associations between sexual orientation and depressive symptoms among Chinese college students, with a focus on gender differences. METHODS: A total of 30,733 college students were recruited from 10 Chinese province-level regions with a multistage, stratified cluster, random sampling method between March and June 2019. The 20-item Center for Epidemiologic Studies Depression Scale (CESD-20) was used to measure the depressive symptoms. Sexual orientation was assessed by asking the question, "Which of the following options best describes you?" The responses were categorized as heterosexual, gay/lesbian, bisexual, and unsure. RESULTS: In our sample (N = 30,733), the prevalence of depressive symptoms was 6.1%. Among the surveyed Chinese college students, 3.7% self-reported as LGB, and 7.2% were unsure. LGB (gay/lesbian: 14.9% for males and 6.8% for females; bisexual: 9.3% for males and 16.4% for females) had a higher risk of depressive symptoms than heterosexuals. After adjusting for control variables, LGB and unsure college students were more likely to have depressive symptoms than their heterosexual peers. For males, unsure college students reported the highest risk of depressive symptoms; for females, lesbian and bisexual college students reported the highest risk of depressive symptoms. LIMITATIONS: The cross-sectional study design and self-reported depressive symptoms and sexual orientation. CONCLUSION: LGB was associated with increased depressive symptoms among Chinese college students. Furthermore, the associations of LGB sexual orientation with depressive symptoms were more robust for females than males.