ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectivePancreatic ductal adenocarcinoma (PDAC) exhibits a limited response to current treatments due to its dense fibrotic stroma and highly immunosuppressive tumor microenvironment. In recent years, advancements in cellular immunotherapy, particularly chimeric antigen receptor macrophage (CAR-M) therapy, have offered new hope for pancreatic cancer treatment. Although CAR-M therapy demonstrates dual potential in directly killing tumor cells and remodeling the immune microenvironment, it still faces challenges such as complex in vitro preparation processes and low in vivo targeting and delivery efficiency. Therefore, developing strategies for efficient and targeted in vivo delivery of CAR genes has become crucial for overcoming current therapeutic limitations. This study aims to develop an orally administrable nano-gene delivery system for the targeted delivery of CAR genes to pancreatic tumor sites. MethodsCore nano-gene particles (PNP/pCAR) were constructed by loading plasmid DNA encoding CAR (pCAR) with cationic polypeptides (PNP). Subsequently, PNP/pCAR was surface-modified with β-glucan to prepare the targeted nanoparticles (βGlus-PNP/pCAR). The loading efficiency of PNP for pCAR was quantitatively assessed by gel retardation assay. The particle size, Zeta potential, morphology, and storage stability of PNP/pCAR were characterized using a Malvern particle size analyzer and transmission electron microscopy. At the cellular level, RAW 264.7 macrophages were selected. The cytotoxicity of PNP/pCAR was evaluated using the CCK-8 assay. The cellular uptake efficiency and lysosomal escape ability of the nanoparticles were assessed via flow cytometry and confocal microscopy. Transfection efficiency was quantitatively evaluated by detecting the expression of the reporter gene GFP using flow cytometry. At the in vivo level, an orthotopic pancreatic cancer mouse model was established. Cy7-labeled βGlus-PNP/pCAR nanoparticles were administered orally, and the fluorescence distribution in mice was dynamically monitored at 1, 2, 4, 8, and 16 h post-administration using a small animal in vivo imaging system. Forty-eight hours after oral gavage, the mice were euthanized, and pancreatic tumor tissues were collected for further analysis of intratumoral fluorescence signals using the imaging system. Additionally, βGlus-PNP/pCAR-GFP nanoparticles loaded with the reporter gene (GFP) were administered orally. Forty-eight hours post-administration, pancreatic tumor tissues were harvested to prepare frozen sections, and GFP expression was observed and analyzed under a fluorescence microscope. ResultsThe PNP carrier exhibited a high loading capacity for pCAR. The successfully prepared PNP/pCAR nanoparticles were regular spheres with a hydrodynamic diameter of approximately (120±10) nm and a Zeta potential of about +(6±1) mV. They maintained good structural stability after incubation in PBS buffer for 7 d. Cell experiments demonstrated that PNP/pCAR exhibited no significant cytotoxicity in RAW 264.7 cells while being efficiently internalized and effectively escaping lysosomal degradation. The transfection positive rate of PNP/pCAR-GFP in RAW 264.7 cells reached (25±3)%, surpassing that of Lipofectamine 2000-loaded pCAR-GFP (Lipo/pCAR-GFP), which was (20±1)%.In vivo experiments revealed that, compared to unmodified PNP/pCAR, βGlus-PNP/pCAR exhibited strongerin situ pancreatic tumor targeting ability after oral administration. Furthermore, oral administration of βGlus-PNP/pCAR-GFP resulted in significant GFP protein expression detectable within pancreatic tumor tissues. ConclusionThis study successfully constructed and validated an orally administrable, pancreatic cancer-targeting polypeptide-based nano-gene delivery system. It provides an important technological foundation in delivery systems and experimental basis for the subsequent development of in situ CAR-M-based therapeutic strategies for pancreatic cancer.

ObjectiveGastric hemorrhage is one of the most common and life-threatening emergencies of the upper digestive tract. Early identification and continuous monitoring are essential for reducing rebleeding rates and mortality, particularly within the critical early hours after onset. Although endoscopy and radiological imaging can accurately localize bleeding sites, these approaches are invasive, resource-intensive, and unsuitable for continuous bedside monitoring. Electrical impedance tomography (EIT), as a noninvasive and radiation-free functional imaging technique, offers real-time visualization of conductivity distribution and has the potential for detecting intragastric bleeding based on the electrical contrast between blood and surrounding gastric tissues. In this study, a three-dimensional gastric EIT (3D-gEIT) framework is proposed to achieve noninvasive, real-time, and dynamic monitoring of gastric hemorrhage, with emphasis on spatial localization and quantitative volume assessment. MethodsA three-dimensional upper-abdominal simulation model incorporating the stomach, gastric wall, gastric contents, and surrounding tissues was established. Three electrode configurations, namely the dual layer ring, the four layer staggered ring, and the opposed dual plane array, were designed and systematically compared to evaluate their influence on depth sensitivity and spatial resolution. Based on the Tikhonov-Noser hybrid regularization scheme, a region-clustering constraint was introduced to develop the TK-Noser-RCC algorithm. This approach aggregates spatially adjacent elements with similar conductivity variations, thereby enhancing structural continuity and suppressing isolated noise artifacts. To validate the proposed framework, an upper-abdominal physical phantom was constructed using agar to simulate background tissue conductivity. Hemispherical high-conductivity inclusions with volumes ranging from 10 ml to 50 ml were attached to the inner gastric wall to mimic localized bleeding under different gastric filling states. Boundary voltages were acquired under a 120 kHz excitation current and reconstructed using the TK-Noser-RCC algorithm. Furthermore, an in vivo animal experiment was performed using a porcine model with adult-scale abdominal dimensions. A total of 100 ml of autologous blood was injected incrementally into the stomach to simulate progressive gastric hemorrhage, and time-difference EIT reconstruction was conducted at each injection stage to assess the dynamic system response under physiological conditions. ResultsSimulation results demonstrated that the opposed dual-plane electrode array achieved superior depth sensitivity distribution and spatial resolution. For a 40 ml hemorrhage model, the average ICC and SSIM improved by 55.9% and 38.8% compared with the dual-layer ring configuration, and by 64.0% and 39.5% compared with the four-layer staggered configuration. The proposed region-clustering constraint significantly enhanced reconstruction stability. Under added Gaussian noise of 40 dB and 30 dB, ICC values remained approximately 0.85, indicating effective artifact suppression and preservation of boundary integrity. In physical phantom experiments, reconstructed hemorrhage volumes increased approximately linearly with the preset hemispherical volumes, and the reconstructed high-conductivity regions closely matched the actual bleeding locations. Both empty-stomach and full-stomach conditions were evaluated, demonstrating that the opposed dual-plane configuration maintained stable imaging performance across varying gastric contents. In the animal experiment, reconstructed low-impedance regions expanded progressively with increasing injected blood volume. The spatial localization of the hemorrhage remained stable throughout the procedure, and no significant artifacts were observed. Quantitative analysis showed that reconstructed volume and average conductivity variation exhibited an approximately linear growth trend with injected blood volume, confirming the sensitivity of the system to dynamic intragastric conductivity changes. ConclusionThe proposed 3D-gEIT framework enables quantitative reconstruction of gastric hemorrhage volume and spatial distribution with improved depth sensitivity, structural continuity, and noise robustness compared with conventional EIT approaches. By integrating optimized electrode configuration and a region-clustering-constrained reconstruction algorithm, the system provides stable dynamic monitoring under both controlled phantom conditions and in vivo physiological environments. This method offers a noninvasive, real-time, and low-cost imaging strategy for early diagnosis, postoperative monitoring, and bedside surveillance of gastric bleeding.

ObjectiveTo investigate the therapeutic effect of wall-broken ganoderma lucidum spore powder （GLS） on a mouse model of hepatocellular carcinoma and to explore its underlying mechanism. MethodsFifty 2-week-old C57BL/6J mice were divided into a control group， a model group and low， medium and high-dose GLS groups（0.25， 0.5， 1.0 g/kg ）， with 10 mice in each group. A DEN/CCL₄ mouse hepatocellular carcinoma model was established， and GLS was administered by gavage starting from the 8th week， once a day for 14 weeks. At the end of the final administration， the number of liver nodules was observed ， and the serum alpha-fetoprotein （AFP） was detected using enzyme-linked immunosorbent assay. The content of catalase （CAT） in serum and liver tissue was determined by ammonium molybdate method. The content of reduced glutathione （GSH） in serum and liver tissue was measured by microplate assay. The content of glutathione peroxidase （GSH-PX） in serum and liver tissue was detected by colorimetric method. Immunohistochemistry （IHC-P） was employed to detect the protein expression of proliferating cell nuclear antigen （PCNA）. R eal-time fluorescence quantitative polymerase chain reaction was utilized to detect the relative expression of nuclear factor E2-related factor 2 （Nrf2）， Kelch-like epichlorohydrin-associated protein 1 （Keap1）， NAD（P）H quinone oxidoreductase 1 （Nqo1）， heme oxygenase-1 （Ho-1） and glutamate cysteine ligase catalytic subunit （Gclc） mRNA. ResultsCompared with the control group， the content of serum AFP were significantly higher in the model group （P<0.01）， while the contents of CAT， GSH and GSH-PX in liver and serum were significantly lower in the model group （P<0.01）. The relative expression of Keap1 and Nqo1 mRNA was significantly higher （P<0.01）， the relative expression of Nrf2， Ho-1， Gclc mRNA relative expression was significantly lower （P<0.01）， and the positive expression rate of PCNA was significantly higher （P<0.01）. Compared with the model group， the total number of liver nodules and content of serum AFP in the administered group were significantly lower （P<0.01）， and the contents of CAT， GSH， and GSH-PX in the liver and serum of mice significantly increased （P<0.05 or P<0.01）. The expression of Keap1 and Nqo1 mRNA significantly decreased （P<0.05）. The expression of Nrf2， Ho-1 and Gclc mRNA significantly increased （P<0.05）， and positive expression rate of PCNA significantly decreased （P<0.01）. ConclusionGLS has a significant protective effect on DEN/CCL4 -induced mouse hepatocellular carcinoma model， and the mechanism of action is related to the regulation of oxidative stress in mouse liver.

Colorectal cancer (CRC) is characterized by persistently high incidence and mortality. Current therapies are limited by drug resistance and modest patient benefit, underscoring the urgent need for new perspectives rooted in tumor biology. The unique metabolic landscape of CRC makes it an ideal model in which to dissect the pathological roles of lactylation regulatory networks: microsatellite-stable (MSS) CRC, which accounts for approximately 85% of cases, concurrently upregulates glycolysis and oxidative phosphorylation, engaging in intense metabolic competition with immune cells; the intratumoral lactate pool exhibits a distinctive “dual-source supply” feature—in addition to tumor-intrinsic glycolysis, substantial exogenous lactate is provided by gut microbiota dysbiosis and by colonizing bacteria within liver metastases; high-frequency oncogenic mutations and lactylation modifications establish a feed-forward circuit of “oncogene-driven lactate accumulation-lactylation-facilitated tumor progression”. Moreover, MSS CRC displays near-complete unresponsiveness to immune checkpoint inhibitors, a phenomenon underpinned by multiple immune evasion mechanisms mediated by lactate and lactylation. Lactate metabolism is a hallmark of metabolic reprogramming in cancer. Lactate homeostasis provides tumor cells with metabolic substrates, modulates redox status, and regulates fatty acid metabolism to promote malignant progression. Notably, lactate can drive lactylation—an emerging post-translational modification (PTM) in which lactyl groups are attached to lysine residues, dynamically governing gene transcription and protein function and thereby establishing a bridge between metabolism and epigenetics. Lactate and lactylation form a multidimensional, coordinated network: lactylation of key metabolic enzymes such as LDHA reinforces a positive feedback loop that sustains lactate production; lactylation of upstream transcription factors such as HIF-1α drives metabolic reprogramming; furthermore, lactylation engages in crosstalk with m6A and m5C RNA modifications as well as with other PTMs such as acetylation, profoundly reshaping cellular behavior. In CRC, histone lactylation drives malignant phenotypes by activating immunosuppressive programs, inhibiting ferroptosis, and promoting invasion and migration; non-histone lactylation accelerates translation elongation, stabilizes β‑catenin, maintains redox homeostasis, and prevents PD-L1 degradation, thereby facilitating tumor progression. Lactylation-related gene signatures have demonstrated potential for prognostic stratification. Therapeutic strategies targeting the lactylation network range from upstream metabolic intervention to modulation of the modifying enzymes and direct blockade of lactylation modifications, forming a hierarchical interventional framework. However, current evidence derives predominantly from cell lines and xenograft models, and a causal relationship between lactylation and malignant progression in CRC has yet to be rigorously established. Whether inhibition of lactylation can alter CRC phenotypes independently of metabolic alterations and acetylation fluctuations remains a central unanswered question in the field. This review systematically examines the research progress and translational challenges surrounding lactylation regulatory networks, aiming to provide a circumspect assessment to inform the development of novel therapeutic strategies for CRC.

BackgroundPatients with colorectal cancer are frequently comorbid with depression， which severely affects the quality of life and treatment compliance， while compromising the efficacy of anticancer treament and prognosis. Current therapeutic strategies still have notable limitations， particularly the lack of systematic and targeted synergistic regimens that integrate oncological management and anti-depressive intervention. It is of great clinical significance to explore a safe and effective new comprehensive intervention protocol and clarify its underlying mechanism of action. ObjectiveTo explore the effectiveness and safety of Shugan Yunpi Decoction in alleviating depressive and anxiety symptoms in colorectal cancer patients with depressive disorder through the PI3K-AKT signaling pathway， in order to provide references for the comprehensive treatment of colorectal cancer and depressive disorder. MethodsThis study was a randomized controlled trial. A total of 106 patients admitted to the Baoding No.1 Hospital of traditional Chinese medicine from November 2023 to July 2025 were enrolled， who met the diagnostic criteria for the Chinese protocol of diagnosis and treatment of colorectal cancer （2023 edition） and the diagnostic criteria for depressive disorder as specified in the Chinese Classification and Diagnostic Criteria of Mental Disease， third edition （CCMD-3）. Patients were divided into the study group and the control group using a random number table， with 53 cases in each group. The control group received conventional chemotherapy combined with traditional Chinese medicine five-element music therapy， while the study group received conventional chemotherapy combined with Shugan Yunpi Decoction therapy. Both groups were treated for 8 weeks. Depressive and anxiety symptoms were assessed using the Hamilton Depression Scale-17 item（HAMD-17） and Hamilton Anxiety Scale （HAMA）， respectively. Western blot protein immunoblotting was used to detect the expression levels of PI3K， AKT， and pAKT. Real-time fluorescence quantitative reverse transcription polymerase chain reaction （qRT-PCR） was used to detect the expression levels of PI3K mRNA and AKT mRNA. Adverse reactions were recorded using a self-designed adverse reaction record form. ResultsRepeated measures analysis of variance showed that the time effects （F=139.336， 234.747）， group effects （F=43.900， 101.266）， and time-group interaction effects （F=13.409， 43.216） for HAMD-17 and HAMA scores in both groups were statistically significant （P<0.01）. After 4 and 8 weeks of treatment， the HAMD-17 and HAMA scores in both groups were lower than those before treatment， with statistically significant differences （P<0.05）. HAMD-17 and HAMA scores in the study group were lower than those in the control group （P<0.05）. The time effects （F=571.356， 309.266， 414.492）， group effects （F=6.901， 26.361， 39.362）， and time-group interaction effects （F=18.592， 19.266， 33.484） for the protein expression levels of PI3K， AKT， and pAKT in both groups were all statistically significant （P<0.01）. After 8 weeks of treatment， the protein expression levels of PI3K and pAKT in the study group were lower than those in the control group， while the AKT protein expression level was higher than that in the control group（P<0.01）. The time effects （F=338.555， 225.059）， group effects （F=5.429， 9.726）， and time-group interaction effects （F=12.953， 21.214） for PI3K mRNA and AKT mRNA expression levels in two groups were all statistically significant （P<0.01）. After 8 weeks of treatment， the expression levels of PI3K mRNA and AKT mRNA in the study group were lower than those in the control group （P<0.05）. The incidence of adverse reactions in the study group was lower than that in the control group （χ²=4.810， P<0.05）. ConclusionShugan Yunpi Decoction may help to ameliorate depressive and anxiety symptoms in colorectal cancer patients with depressive disorder by regulating the PI3K-AKT signaling pathway， decreasing the levels of PI3K， pAKT， PI3K mRNA， and AKT mRNA， with a favorable safety profile. ［Funded by Baoding City Science and Technology Planning Project （number， 2341ZF291）］

Objective To investigate the antitumor effects of triptolide against CT26 colon cancer and its impact on the expression of Polo-like kinase-1(PLK-1)protein.Methods Forty clean grade BALB/c mice,each mouse was implanted with 1×106 CT26 cells into the dorsal side of the right forelimb to establish a tumor-bearing mouse model.Experimental animals were randomly divided into four groups,the tumor model group(saline control),the positive drug group[oxaliplatin,5 mg/(kg·d)],the low-dose triptolide group[50 μg/(kg·/d)],and the high-dose triptolide group[100 μg/(kg·d)].The drugs were administered through intraperitoneal injection(10 times in total,once every other day).The in vitro effects of the drugs on the proliferation,migration,invasion,and mitosis of CT26 cells were also assessed.Results Triptolide significantly inhibited the proliferation,migration,and invasion of CT26 colon cancer cells,and disrupted the separation of centrosomes and the correct arrangement of chromosomes during the prophase of mitosis in tumor cells.The binding energy of triptolide and PLK-1 protein was-7.1 kcal/mol,and it could down-regulate the expression of PLK-1 in CT26 cells.Conclusion Triptolide exerts its antitumor effects against CT26 colon cancer by downregulating the expression of PLK-1.

(+)-Strebloside, a significant bioactive compound isolated from the roots of Streblus asper Lour., demonstrates inhibitory effects against multiple malignancies. However, its specific function and underlying mechanistic pathways in Non-Hodgkin lymphoma (NHL) remain unexplored. This investigation sought to elucidate the role and potential mechanisms of (+)-strebloside-induced NHL cell death. The results demonstrated that (+)-strebloside significantly induced apoptosis and ferroptosis in NHL cells, including those from Raji cell-derived xenograft models. Mechanistic analyses revealed that (+)-strebloside enhanced six-transmembrane epithelial antigen of prostate 3 (STEAP3)-induced ferroptosis in NHL, and STEAP3 inhibition reduced the proliferation-inhibitory effects of (+)-strebloside. Furthermore, (+)-strebloside suppressed NHL proliferation through the mitogen-activated protein kinase (MAPK) pathway, and extracellular signal-regulated kinase (ERK) inhibition diminished the proliferation-inhibitory activity induced by (+)-strebloside. These findings indicate that (+)-strebloside presents promising therapeutic potential for NHL treatment.
Humans ; Ferroptosis/drug effects* ; Lymphoma, Non-Hodgkin/physiopathology* ; Cell Line, Tumor ; MAP Kinase Signaling System/drug effects* ; Animals ; Cell Proliferation/drug effects* ; Mice ; Apoptosis/drug effects* ; Membrane Proteins/genetics* ; Xenograft Model Antitumor Assays ; Male ; Mice, Nude

OBJECTIVE: The study aim was to investigate the effects of exposure to multiple environmental organic pollutants on cardiopulmonary health with a focus on the potential mediating role of oxidative stress. METHODS: A repeated-measures randomized crossover study involving healthy college students in Beijing was conducted. Biological samples, including morning urine and venous blood, were collected to measure concentrations of 29 typical organic pollutants, including hydroxy polycyclic aromatic hydrocarbons (OH-PAHs), bisphenol A and its substitutes, phthalates and their metabolites, parabens, and five biomarkers of oxidative stress. Health assessments included blood pressure measurements and lung function indicators. RESULTS: Urinary concentrations of 2-hydroxyphenanthrene (2-OH-PHE) ( β = 4.35% [95% confidence interval ( CI): 0.85%, 7.97%]), 3-hydroxyphenanthrene ( β = 3.44% [95% CI: 0.19%, 6.79%]), and 4-hydroxyphenanthrene (4-OH-PHE) ( β = 5.78% [95% CI: 1.27%, 10.5%]) were significantly and positively associated with systolic blood pressure. Exposures to 1-hydroxypyrene (1-OH-PYR) ( β = 3.05% [95% CI: -4.66%, -1.41%]), 2-OH-PHE ( β = 2.68% [95% CI: -4%, -1.34%]), and 4-OH-PHE ( β = 3% [95% CI: -4.68%, -1.29%]) were negatively associated with the ratio of forced expiratory volume in the first second to forced vital capacity. These findings highlight the adverse effects of exposure to multiple pollutants on cardiopulmonary health. Biomarkers of oxidative stress, including 8-hydroxy-2'-deoxyguanosine and extracellular superoxide dismutase, mediated the effects of multiple OH-PAHs on blood pressure and lung function. CONCLUSION Exposure to multiple organic pollutants can adversely affect cardiopulmonary health. Oxidative stress is a key mediator of the effects of OH-PAHs on blood pressure and lung function.
Humans ; Oxidative Stress/drug effects* ; Male ; Cross-Over Studies ; Female ; Young Adult ; Environmental Pollutants/toxicity* ; Environmental Exposure/adverse effects* ; Biomarkers/blood* ; Adult ; Blood Pressure/drug effects* ; Polycyclic Aromatic Hydrocarbons/urine* ; Beijing