Background Toluene and chlorobenzene have been designated as surrogate contaminants in the challenge test for evaluating the safety of recycling processes for food-contact recycled polyethylene terephthalate (rPET). Establishing a reliable analytical method is essential for ensuring the compliant use of rPET and safeguarding food safety. Objective To develop a rapid quantitative method for determining toluene and chlorobenzene in rPET using headspace gas chromatography-mass spectrometry (HS-GC-MS), as part of the challenge test for process safety evaluation. Methods The effects of different chromatographic columns and headspace conditions on detection of target analytes were investigated. Three columns HP-5 ms UI (30 m×0.25 mm×0.25 μm), DB-624 (30 m×0.32 mm×1.8 μm), and VF-WAXms (30 m×0.25 mm×0.25 μm) were compared for separation efficiency and peak shape. Headspace equilibration temperatures (50-100 ℃) and equilibration times (10-30 min) were evaluated to determine the optimal instrumental parameters. The effect of sample grinding on recovery was assessed to select the best pretreatment conditions. The established method was validated for selectivity, linearity, sensitivity, accuracy, and precision, and was subsequently applied to the analysis of 12 rPET samples. Results The target analytes achieved good separation and response within 15 min, under the optimized conditions using an HP-5 ms UI column, a headspace equilibration temperature of 60 ℃ and a 10 min equilibration time. Direct analysis without grinding yielded satisfactory recovery rates. Toluene and chlorobenzene showed excellent linearity (0.0030-5.0 mg·kg⁻¹, R²≥0.999). The limits of detection (LOD) and quantification (LOQ) were 0.00003 mg·kg⁻¹ and 0.00011 mg·kg⁻¹ for toluene respectively, and 0.00011 mg·kg⁻¹ and 0.00037 mg·kg⁻¹ for chlorobenzene respectively. The recoveries of the matrix spike at low and high spiking levels ranged from 88.6% to 110%, with relative standard deviations of 0.52%-4.9% (n=6). Among the 12 rPET samples from different recycling stages, three samples contained detectable levels of toluene (0.196-0.250 mg·kg⁻¹) and chlorobenzene (0.704-0.867 mg·kg⁻¹). Conclusion The proposed method is simple, rapid, highly sensitive, and accurate, making it suitable for determining toluene and chlorobenzene in food-contact rPET. It provides a robust technical approach for the safety evaluation of rPET recycling processes.

Background Long working hours, as a common risk factor for occupational stress, is closely related to the occurrence of depressive symptoms. Understanding how long working hours affect occupational stress and depressive symptoms will inform occupational health interventions. Objective To quantify the impact of long working hours exposure on occupational stress and depressive symptoms among Internet industry employees, translate black-box outputs into actionable insights, and demonstrate the value of interpretable machine learning for early-warning occupational-health surveillance. Methods A dataset was derived from a cross-sectional survey involving 2866 internet industry employees in China. This survey was part of the project Risk Assessment Of Long Working Hour Exposure And Its Adverse Health Effects, conducted by the National Institute for Occupational Health and Poisoning Control, Chinese Center for Disease Control and Prevention, from 2021 to 2023. Working hours, occupational stress and depressive symptoms were quantified with a set of structured questionnaires including the Core Occupational Stress Scale and the Patient Health Questionnaire. Pairwise associations were screened by Mantel tests and variance-inflation factors. Key predictors identified through feature selection were fed into six machine-learning risk-prediction models. Visual interpretation was provided by feature importance, Shapley additive explanations (SHAP) and local interpretable model-agnostic explanations (LIME), while directed causal effects and intervention impacts of prolonged working hours exposure on occupational stress and depressive symptoms were dissected with causal explanation of features techniques. Results The positive rates of occupational stress and depressive symptoms among internet employees were 12.9% and 77.8% respectively. Twelve core features for occupational stress and nine for depressive symptoms were retained after selection. After these features were supplied to six predictive algorithms and evaluated on five metrics, the Light Gradient Boosting Machine (LGBM) achieved the highest accuracy—0.89 for occupational stress and 0.79 for depressive symptoms on the hold-out test set. The feature-importance rankings converged on fatigue accumulation and life satisfaction as dominant drivers for both outcomes, whereas weekly working hours and daily overtime emerged as the principal exposure-related predictors. The SHAP summary plots revealed that longer weekly hours and daily overtime systematically elevated the probability of occupational stress. The causal feature explanation further quantified that ascending one category in weekly working hours increased the probability of occupational stress by 7.04%. Conclusion Exposure to long working hours is associated with both occupational stress and depressive symptoms among internet industry employees. Interpretable machine-learning frameworks translate these associations into transparent, defensible drivers, enabling precise identification of the pivotal factors and their interplay. This evidence base equips occupational-health practitioners with actionable insights for designing targeted prevention and intervention strategies.

Objective: To evaluate the diagnostic performance of magnetic resonance spectroscopy (MRS) in discriminating fumarate hydratase-deficient (FH-d) uterine leiomyomas (ULs) from FH-preserved ULs. Materials and Methods: This study consisted of three stages, with independent cohorts recruited for each stage: 1) sample-size estimation was retrospectively performed on UL specimens (diameter ≥3 cm; age, 20–40 years) from our database with immunohistochemistry (IHC) for 2-succinocysteine (2-SC) as the reference, without genetic testing, 2) MRS sequence optimization in confirmed FH germline mutation participants with ultrasound-detected ULs (diameter ≥3 cm), without IHC analysis, and 3) prospective diagnostic test accuracy was evaluated in consecutive participants with ultrasound-detected ULs (diameter ≥3 cm;age, 20–40 years), using IHC for 2-SC for determining the FH status and subsequent genetic testing in those with positive 2-SC results to identify whether FH mutations were germline or somatic in origin. The choline and fumarate peaks in MRS were classified as positive, negative, or technical failure (TF). TFs were analyzed separately and excluded from the primary diagnostic accuracy calculations. T1-, T2-, and diffusion-weighted images were interpreted as hyperintense or hypointense. The enhancement rate and apparent diffusion coefficient were also acquired. Diagnostic performance was compared between MRS and various magnetic resonance imaging (MRI) features. Results: The optimal MRS parameters for the fumarate peak were echo time (TE) = 140 ms and an average of 256. Among the 360 prospective participants, 37 were confirmed to have FH-dULs. MRS showed positive fumarate peaks in 35 of 37 FH-dULs.After excluding six TFs, the positive fumarate peak on MRS showed 94.6% (35/37) sensitivity, 99.7% (316/317) specificity, and 99.2% (351/354) accuracy, all of which were significantly superior to those of other MRI features (P ≤ 0.002). Conclusion A positive fumarate peak on MRS may be a useful imaging biomarker for diagnosing FH-dULs.

Background/Aims: Natural killer (NK) cell function is generally considered dampened in chronic hepatitis B virus (HBV) infection; however, the NK cell pool exhibits phenotypic and functional heterogeneity, and the antibody--mediated effect of NK cells remains less characterized. This study evaluated the dynamic changes in antibody-mediated NK cell responses and the involvement of distinct NK subsets across disease stages and during antiviral treatment. Methods: A T-cell receptor-like antibody specific for the HBV core 18–27 peptide (cTCRL-Ab) was used to determine the antibody-mediated effect of NK cells, and an array of NK cell surface markers were analyzed in cross-sectional and longitudinal cohorts of patients with chronic HBV infection. Single-cell RNA sequencing (scRNA-seq) was performed to identify the heterogeneity of NK subsets. Results: The cTCRL-Ab enabled the detection of NK cell cytolytic activity and IFNγ production. Notably, cTCRL-Ab-mediated NK cell responses were compromised in chronically HBV-infected patients, particularly in those receiving pegylated interferon-α (Peg-IFNα), which was associated with the downregulation of CD16 expression. Correspondingly, Peg-IFNα inhibited cTCRL-Ab-mediated NK cell function by reducing CD16 expression in vitro. scRNA-seq revealed that CD16 downregulation occurred mainly within a dysfunctional CD16hi NK subset exhibiting exhaustion properties. In contrast, an activated CD16hiNK subpopulation (CX3CR1⁺KLRC2–CD16hi) with high cytotoxicity was enriched in patients who experienced favorable treatment responses. Furthermore, the intrahepatic CX3CR1+KLRC2–CD16hi subset tended to exhibit functional restoration in HBsAg-loss individuals. Conclusions Our data contribute to the understanding of antibody-mediated responses of NK cells in chronic HBV infection, and highlight a previously unappreciated functional CX3CR1+KLRC2–CD16hiNK subset as a potential therapeutic target.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

ObjectiveTo investigate the role and underlying mechanism of the Wnt/β-catenin signaling pathway in the process of Xiaojinwan （XJW）-containing serum interfering with endothelial-mesenchymal transition （EMT） in human breast cancer MDA-MB-231 cells. MethodsXJW-containing serum was prepared by intragastric administration of XJW （4 g·kg^-1） to SD rats. MDA-MB-231 cells were cultured in vitro. β-Catenin overexpression and knockdown plasmids were constructed and transfected into MDA-MB-231 cells. The optimal XJW-containing serum （4 g·kg^-1） according to previous studies was used for β-catenin intervention and overexpression experiments. The groups for intervention/overexpression experiments included intervention/overexpression blank group， β-catenin intervention/overexpression group， intervention/overexpression blank + XJW group， and β-catenin intervention/overexpression + XJW group. Cell morphology was observed under a microscope. Flow cytometry was used to detect and record apoptosis rates. Western blot was performed to measure apoptosis-related proteins ［B-cell lymphoma 2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and active-Caspase-3］ and EMT-related proteins （E-cadherin， N-cadherin， and vimentin）. Real-time polymerase chain reaction （Real-time PCR） was used to detect β-catenin mRNA expression levels in different groups. ResultsIntervention experiment results showed that compared with the intervention blank group， the β-catenin intervention group and the intervention blank + XJW group showed increased apoptosis rates （P<0.05， P<0.01）， elevated protein levels of Bax， active Caspase-3， and E-cadherin （P<0.05， P<0.01）， and decreased protein levels of Bcl-2 and Vimentin （P<0.05， P<0.01）. β-catenin mRNA expression was reduced in the β-catenin intervention group （P<0.05， 0.63 ± 0.15） and the intervention blank + XJW group （P<0.05， 0.79 ± 0.33）. Compared with the β-catenin intervention group， the β-catenin intervention + XJW group exhibited an increased apoptosis rate （P<0.01）， elevated Bax and active Caspase-3 protein levels （P<0.05， P<0.01）， and decreased Bcl-2， N-cadherin， and Vimentin protein levels （P<0.05）. β-catenin mRNA expression was further reduced in the β-catenin intervention + XJW group （P<0.01， 0.22 ± 0.08）. Compared with the intervention blank + XJW group， the β-catenin intervention + XJW group showed an increased apoptosis rate （P<0.01）， elevated Bax， active Caspase-3， and E-cadherin protein levels （P<0.05， P<0.01）， and decreased Bcl-2， N-cadherin， and vimentin protein levels （P<0.05， P<0.01）. β-catenin mRNA expression was also reduced （P<0.05）. Overexpression experiment results showed that compared with the overexpression blank group， the β-catenin overexpression group exhibited a reduced apoptosis rate （P<0.01）， while the overexpression blank + XJW group showed an increased apoptosis rate （P<0.05）. In the β-catenin overexpression and β-catenin overexpression + XJW groups， Bax and E-cadherin protein levels decreased （P<0.05， P<0.01）， while Bcl-2， N-cadherin， and vimentin levels increased （P<0.05）. In the overexpression blank + XJW group， Bax and E-cadherin levels increased （P<0.05， P<0.01）， while Bcl-2， N-cadherin， and vimentin levels decreased （P<0.05， P<0.01）. β-catenin mRNA expression increased in the β-catenin overexpression group （P<0.01， 7.26 ± 1.03） but decreased in the overexpression blank + XJW group （P<0.05， 0.73 ± 0.14）. Compared with the β-catenin overexpression group， the β-catenin overexpression + XJW group showed an increased apoptosis rate （P<0.01）， elevated Bax and E-cadherin levels （P<0.05）， and decreased N-cadherin and vimentin levels （P<0.05）. β-catenin mRNA expression was reduced （P<0.05， 4.65 ± 1.02）. Compared with the overexpression blank + XJW group， the β-catenin overexpression + XJW group exhibited a reduced apoptosis rate （P<0.01）， decreased Bax and E-cadherin levels （P<0.01）， and increased Bcl-2， N-cadherin， and Vimentin levels （P<0.05）. β-catenin mRNA expression increased （P<0.01）. ConclusionXJW-containing serum inhibits breast cancer cell proliferation by suppressing EMT， which is associated with the regulation of the Wnt/β-catenin pathway.

ObjectiveTo establish a mouse model of hypoxic pulmonary hypertension (HPH) through intermittent hypoxia induction, and to develop a comprehensive and reliable evaluation system for the HPH model, thereby providing experimental evidence for mechanistic studies and translational applications related to this disease. MethodsTwenty-four male specific pathogen-free (SPF) BALB/c mice were randomly divided into a control group and a model group, with 12 mice per group. Mice in the model group were placed in a hypobaric oxygen chamber control system to establish the HPH model, whereas mice in the control group received no intervention. After 28 days of modeling, a comprehensive evaluation of the pathophysiological characteristics of both groups was performed using a general condition scoring scale, echocardiography, hemodynamic measurements, blood gas analysis, hematological tests, organ coefficient determination, histopathological examination, and enzyme-linked immunosorbent assay (ELISA). In addition, correlation analyses were conducted among echocardiographic parameters, the contents of endothelin‑1 (ET‑1) and N‑terminal pro‑B‑type natriuretic peptide (NT‑proBNP) in lung tissue, and other measured indices. ResultsWith prolonged modeling duration time, body weight, water intake, and activity level of mice in the model group were significantly decreased compared with the control group (P<0.05). Echocardiography showed that, compared with the control group, the model group exhibited increased right ventricular dimensions (P<0.01), right ventricular anterior wall thickening (P<0.01), and widened main pulmonary artery diameter (P<0.01), whereas the peak systolic velocity across the pulmonary valve, tricuspid annular plane systolic excursion, and peak systolic velocity of the tricuspid annulus were significantly decreased (P<0.001); tricuspid regurgitation was observed in some model animals. Hemodynamic results revealed that right ventricular systolic pressure was elevated in the model group compared with the control group (P<0.001). Blood gas analysis showed that pH, partial pressure of oxygen, oxygen saturation, actual bicarbonate, and total carbon dioxide were all decreased in the model group compared with the control group (P<0.01). Hematological indices demonstrated that lymphocyte counts (P<0.05) and reticulocyte counts (P<0.001) were decreased in the model group compared with the control group. Compared with the control group, the organ coefficients of heart and lung in the model group were significantly increased (P<0.05 and P<0.001). Pathological examination revealed that the right ventricular hypertrophy index was significantly increased in the model group (P<0.001), with varying degrees of damage to the right ventricle, pulmonary artery, and pulmonary vessels; both the pulmonary artery wall thickness percentage and the pulmonary wall area percentage were significantly elevated (P<0.001). ELISA results showed that the levels of ET‑1 and NT‑proBNP in lung tissues were significantly increased in the model group compared with the control group (P<0.05 and P<0.001, respectively). Correlation analysis indicated that some echocardiographic parameters were highly correlated with multiple indices in the development of HPH (P<0.05). ConclusionEchocardiography can accurately assess a series of hemodynamic changes in HPH, including right ventricular structural, functional impairment, and pulmonary hypertension. Laboratory tests not only help verify whether the model has been successfully established, but also provide deeper insights into the pathogenesis of HPH, evaluate the effects of interventions, and offer scientific evidence for clinical outcomes. Pathological examination can further confirm the alterations in pulmonary vascular remodeling and increased right heart load. This multimodal analysis provides a reliable animal model and evaluation paradigm for both basic and translational research on HPH, and is of great significance for exploring disease mechanisms and developing precision therapeutic strategies.

Based on the theory of collateral disease， the treatment of late-stage sequela of cerebrovascular disease is considered to be primarily associated with deficiency and obstruction of cerebral collaterals and dysfunction of the spirit mechanism. Therefore， the fundamental therapeutic principle is to unblock and supplement the brain collaterals. Clinically， the late-stage sequelae of cerebrovascular disease are classified into four patterns， which are malnourishment， deficiency-heat， stasis obstruction， and phlegm clouding of brain collaterals. These are treated respectively with Tiansui Tongqiao Decoction （填髓通窍汤） to supplement essence and nourish the brain through moistening， unblocking and supplementing， Qingnao Touluo Decoction （清脑透络汤） to enrich yin， regulate spirit， and unblock collaterals through clearing and penetrating， Yiqi Tongluo Decoction （益气通络汤） to tonify qi and resolve stasis while softening tendons and unblocking collaterals， and Xinrun Touqiao Beverage （辛润透窍饮） to unblock and tonify yin and yang while unblocking the collaterals through acrid-moistening medicinals. Flexible modification of prescriptions according to individual symptoms was applied， resulting in favorable therapeutic outcomes.

ObjectiveTo investigate the effect and underlying mechanism of the Wulao Qisun prescription on pathological new bone formation in ankylosing spondylitis （AS）. MethodsSynovial fibroblasts were isolated from the hip joints of AS patients and observed under a microscope to assess cell morphology. The cells were identified using immunofluorescence staining. The isolated AS fibroblasts were divided into blank group， low drug-containing serum group， medium drug-containing serum group， high drug-containing serum group， and positive drug group. After drug intervention， cell proliferation was measured using the cell counting kit-8 （CCK-8） assay to observe fibroblast growth and determine the optimal intervention time. Alkaline phosphatase （ALP） activity was measured using the alkaline phosphatase assay. Protein expression of osteocalcin （OCN）， osteopontin （OPN）， and runt-related transcription factor 2 （Runx2） was detected by Western blot. The mRNA expression levels of Wnt5a， β-catenin， and Dickkopf-1 （DKK-1） were measured by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultsCompared with the blank group， each drug-containing serum group of Wulao Qisun prescription and the positive drug group inhibited the proliferation of AS fibroblasts and reduced ALP expression （P<0.01）. Compared with the blank group， the low drug-containing serum group of Wulao Qisun prescription downregulated β-catenin mRNA expression （P<0.05）. The medium and high drug-containing serum groups and the positive drug group significantly downregulated Wnt5a and β-catenin mRNA expression （P<0.05， P<0.01）， with the positive drug group showing the most pronounced effect （P<0.01）. The high drug-containing serum group and the positive drug group significantly upregulated DKK-1 mRNA expression （P<0.01）. Compared with the blank group， the low drug-containing serum group of Wulao Qisun prescription inhibited the expression of OPN and Runx2 proteins （P<0.05， P<0.01）， while the medium and high drug-containing serum groups and the positive drug group inhibited the expression of OCN， OPN， and Runx2 proteins （P<0.05， P<0.01）. ConclusionThe Wulao Qisun prescription can inhibit the proliferation and osteogenic differentiation of AS fibroblasts， thereby delaying the formation of pathological new bone in AS. The possible mechanism involves the regulation of Wnt/β-catenin-related gene expression， further inhibiting the transcription of downstream target genes.

Linxian County in Henan Province, Northern China is known as the region with the highest incidence and mortality rate of esophageal cancer worldwide. Since 1959, the Henan medical team has conducted field work on esophageal cancer prevention and treatment in Linxian. Through three generations of effort exerted by oncologists over 65 years of research on esophageal cancer prevention and treatment in Linxian, the incidence rate of esophageal squamous cell carcinoma in this area has dropped by nearly 50%, and the 5-year survival rate has increased to 40%, reaching the international leading level. This article aims to summarize the history, present opportunities and new challenges, and explore the experience of esophageal cancer prevention and treatment in Linxian (referred to as the “Linxian experience”), providing reference and guidance to cancer prevention and treatment research in China.