Environmental pollution is a significant public health challenge worldwide, and investigating the causal relationship between environmental exposure and population health outcomes is a key objective of environmental epidemiology research. In recent years, the complexity of environmental exposures has increasingly come to the forefront, making it challenging for observational studies that dominate environmental epidemiology to accurately estimate causal effects. Causal inference methods are particularly advantageous in controlling for confounding factors, thus holding great potential in environmental epidemiology research. Researchers can use appropriate causal inference methods to simulate the process of randomization, providing strong support for revealing the causal relationship between environmental exposure and health outcomes. However, there is a lack of reviews on the application of causal inference methods in environmental epidemiology studies in China. Therefore, this study introduced the basic principles of common causal inference statistical methods in environmental epidemiology, summarized the applicable conditions, advantages and disadvantages of various methods, and provided R software implementation codes for these methods, aiming to offer guidance for optimizing research design and practicing causal inference statistical methods.

Objective: To assess the effect of 12-year-old children s pit and fissure sealants on the health of first permanent molars, so as to provide evidence for optimizing caries prevention strategies among children. Methods: In March 2025, a cluster random sampling method was used to conduct oral examinations on 965 students aged 12 from Chengdu s 2021 Comprehensive Intervention Program for Pediatric Oral Diseases. Data from the Comprehensive Intervention System for Children s Oral Diseases were referenced. Participants were divided into a sealed group ( n =755) and an unsealed group ( n =210) based on whether they had received sealants on their first permanent molars. Chi square test or analysis of variance were used to compare indicators such as caries incidence, new caries detection rate, and new caries mean (DMFT increment) between the two groups Results: The sealed group showed significantly lower caries incidence, new caries detection rate, and new caries mean (33.38%, 17.65%, 0.59±1.00) compared to the unsealed group (43.81%, 24.70%, 0.87±1.22)( χ 2/F =7.79, 18.26, 9.55, all P <0.05). However, no significant difference was found in the filled teeth ratio between the two groups (20.38% , 20.16%; χ 2=0.01, P =0.94). In girls, the sealed group exhibited significantly lower caries incidence, new caries detection rate, and new caries mean (36.78%, 20.99%, 0.69± 1.10 ) than the unsealed group (57.55%, 33.52%, 1.15±1.29) ( χ 2/F =14.42, 23.76, 10.92, all P <0.05), whereas no significant differences were observed between boys in the sealed (30.47%, 14.85%, 0.50±0.89) and unsealed groups (29.81%, 16.18%, 0.59± 1.08) ( χ 2/F =0.02, 0.41, 0.74, all P >0.05). Boys had significantly lower new caries detection rates and new caries means than girls in both groups ( χ 2/F =16.20, 6.94; 29.93, 11.84, all P <0.05). In urban areas, the sealed group had lower new caries detection rates and new caries means (19.37%, 0.68±1.04) than the unsealed group (24.66%, 0.90±1.20) ( χ 2/F =6.86, 3.94, both P <0.05). In suburban areas, all indicators for the sealed group (24.71%, 13.77%, 0.42±0.87) were significantly lower than those for the unsealed group (38.81%, 24.77%, 0.82±1.28) ( χ 2/F =5.28, 15.36, 6.00, all P <0.05). Indicators from specialized dental institutions (11.25%, 4.81%, 0.16±0.56) were significantly lower than those from county level or above general hospitals (33.33%, 19.11%, 0.38±1.00) and primary healthcare institutions (37.59%, 19.24%, 0.67±1.05) ( χ 2/F =20.99, 34.31, 21.08 , all P <0.01). Conclusions The 12-year-old children s pit and fissure sealants effectively reduce the caries incidence in first permanent molars, particularly showing significant effectiveness in girls and suburban children. Intervention strategies should be optimized according to gender.

Spine fracture and dislocation are common traumatic spinal conditions that often require surgical intervention due to compromised spinal stability. Surgical approaches include anterior, posterior, and combined anterior-posterior spinal procedures. According to the specific surgical requirements, patients may be placed in the prone position or repositioned between prone and supine positions during surgery. Intraoperative repositioning has become an essential step in patient positioning. However, during repositioning, patients with spinal fracture and dislocation are at increased risk for complications such as hemodynamic instability, nerve injury, and pressure injuries to the skin and soft tissue. Notably, due to the instability of the spinal cord, even minor manipulations can further exacerbate the damage, potentially leading to severe outcomes like paraplegia. Although the current clinical guidelines provide instructive recommendations for standard position, there remains no specific protocols for intraoperative repositioning in patients with spine fracture and dislocation. With a concern for the lack of clinical studies on positioning techniques, risk prevention, and operational norms for special patients, no applicable guidelines or standards are available. A consensus was required to provide clinical reference, meet the requirements of surgical treatment, and minimize the safety risks of patients caused by improper placement of positions. Professional Committee of Operating Room Nursing of Shaanxi Nursing Association organized experts in nursing management and operating room nursing from major hospitals across China to formulate Expert consensus on intraoperative repositioning for patients with spinal fracture and dislocation ( version 2025). The consensus provides 11 recommendations covering pre-repositioning preparation, intraoperative maneuvers, and post-repositioning observation, aiming to provide references for clinical standardization of the intraoperative repositioning process and protection of patients′ safety.

Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Objective:To evaluate the cumulative live birth rate (CLBR) and cost-effectiveness of fixed versus adjusted follicle-stimulation hormone (FSH) dosages in infertile women with different ovarian responses during their first assisted reproductive technology (ART) cycle.Methods:A retrospective real-world cohort study was conducted on 5 419 infertile women who underwent their first ART treatment at the Department of Reproductive Medicine of the First Affiliated Hospital of Nanjing Medical University between January 2013 and December 2017. All patients received an individualized starting dosage of gonadotropin. Based on whether FSH dosages were adjusted during controlled ovarian stimulation (COS), patients were divided into fixed-dosage group ( n=2 061) and adjusted-dosage group ( n=3 358). Clinical outcomes and FSH cost-effectiveness were compared between the two groups across different ovarian response groups, with CLBR as the primary outcome. Propensity score matching (PSM) and multivariable logistic regression were used to adjust for potential confounders. Results:FSH dosage adjustments were found in 62.0% (3 358/5 419) of cycles during COS. After PSM, baseline characteristics were comparable between the two groups (all P>0.05). After adjusting for confounders using multivariable logistic regression, FSH dosage adjustment was not significantly associated with CLBR ( OR=1.06, 95% CI: 0.94-1.20, P=0.332). Compared with the adjusted-dosage group, the fixed-dosage group showed no significant differences in CLBR in poor-, normal-, and high-responder groups (all P>0.05). The incidence of ovarian hyperstimulation syndrome (OHSS) did not differ significantly between the two groups ( P>0.05). In poor-, normal-, and high-responder groups, the total FSH dosages in the fixed-dose group [1 350 (375, 1 825) U, 1 200 (375, 1 500) U and 525 (375, 1 128) U, respectively] were significantly lower than those in the adjusted-dose group [1 875 (1 425, 2 294) U, P=0.001; 1 425 (450, 1 875) U, P<0.001; 600 (375, 1 425) U, P=0.020]. Similarly, average FSH costs in different ovarian response groups in the fixed-dosage group [4 725.0 (1 312.5, 6 387.5) yuan, 4 200.0 (1 312.5, 5 250.0) yuan and 1 837.5 (1 312.5, 3 947.3) yuan, respectively] were significantly lower than those in the adjusted-dosage group [6 562.5 (4 987.5, 8 028.1) yuan, P=0.001; 4 987.5 (1 575.0, 6 562.5) yuan, P<0.001; 2 100.0 (1 312.5, 4 987.5) yuan, P=0.020]. For normal-responders, the FSH cost per high-quality embryo in the fixed-dosage group [1 365.0 (875.0, 2 537.5) yuan] was significantly lower than that in the adjusted-dosage group [2 056.3 (1 268.8, 3 412.5) yuan, P<0.001]. Conclusion:FSH dosage adjustment during COS is not associated with CLBR or the incidence of OHSS. However, the fixed-dose group exhibited lower total FSH dosages and costs across different ovarian response populations. In the context of ART being covered by medical insurance, fixed FSH dosage may represent a more cost-effective ovarian stimulation protocol.

Objective To explore the magnetic resonance(MR)imaging characteristics of joint damage caused by Chikungunya virus(CHIKV)and its correlation with pain severity,and analyze the value of T2-Mapping in asse-ssing the severity and prognosis of such damage.Methods A multicenter retrospective study design was adopted,and patients with CHIKV infection accompanied by joint pain were included in analysis.Multi-joint MR scans were performed to assess joint effusion,synovial thickening,bone marrow edema,and cartilage damage.T2-Mapping values were measured.Pain severity was assessed using the Visual Analog Scale(VAS),and imaging findings were independently assessed by two radiologists.Results A total of 131 patients were included in the study.The inci-dence of joint cavity and/or synovial sac effusion was the highest(77.1％,n=101),with knee and ankle joint effu-sion accounting for 81.2％(severe,mild-moderate were 17 and 65 cases,respectively),other joint effusion were mild.78 cases had synovial thickening(14 and 64 were severe and mild-moderate cases,respectively),27 cases had tenosynovitis,21 cases had bone marrow edema(primarily in the knee and ankle joints).19 cases had cartilage damage,114 cases presented muscle soft tissue edema(17 and 97 were severe and mild-moderate cases,respective-ly),28 cases had Kager's fat pad edema.Patients with elevated T2-Mapping values exhibited more pronounced chronic joint pain,with T2-Mapping values in the cartilage damage site increasing by 40％-60％compared with normal cartilage site(19 cases in total).The T2-Mapping value for severely damaged soft tissue was(52.3+6.7)ms,while for mildly to moderately damaged soft tissue was(42.3±5.2)ms,both significantly higher than normal refe-rence values(＜35 ms,both P＜0.05).Among 17 patients with severe soft tissue damage,12 experienced persistent pain for over one month,with statistically significant differences in T2 values compared with those with mild-mode-rate damage(P＜0.05).This further suggested that the degree of elevation in T2-Mapping values was closely related to the duration of pain and the severity of damage.After one-month follow-up,103 patients had pain relief.Among the 28 patients with ongoing pain,17 developed into subacute bone joint pain.Bone marrow edema(81.0％),ele-vation of T2-Mapping value of cartilage(89.5％),and severe synovial thickening(71.4％)were high-risk MR manifestations of subacute bone joint pain.The incidences of subacute joint cavity/sac effusion and subacute tenosy-novitis were 3.0％and 7.4％,respectively.Conclusion MR can clearly display the inflammatory and structural changes in CHIKV joint damage,and T2-Mapping values may serve as a potential imaging measurement parameter for assessing severity and prognosis of damage.

Objective:To investigate the effect of COX6C on the proliferation of multiple myeloma(MM)cells and its mechanism of action.Methods:The expression of COX6C in MM cell lines were detected by RT-PCR.siRNA technology was used to knockdown COX6C expression in OPM2 cells.MTT assay and flow cytometry were employed to assess the effect of COX6C knockdown by siRNA on cell proliferation,mitochondrial membrane potential(Δ Ψm),and intracellular adenosine triphosphate(ATP)levels.The mitochondrial morphological changes in OPM2 cells pre-and post-siRNA-mediated COX6C knockdown were observed by transmission electron microscopy(TEM).Results:The relative expression level of COX6C was significantly increased in MM cell lines(P＜0.01).Following siRNA-mediated COX6C knockdown,OPM2 cell proliferation was inhibited,with viable cells accounting for 62.32％±3.43％and 47.01％±5.12％after 48 and 72 hours of culture,respectively.siRNA-mediated COX6C knockdown also caused significant reductions in mitochondrial membrane potential and intracellular ATP levels(P＜0.05),accompanied by mitochondrial shortening,swelling,and incomplete cristae structures.Conclusion:COX6C may promote the proliferation of MM cells by altering the mitochondrial structure and elevating intracellular ATP levels.

In order to study whether there is a direct interaction between the key variant gene(AP-PV-YN-Mut)protein of atypical porcine pestivirus(APPV)Yunnan strain and the host protein signal sequence receptor subunit 4(SSR4),the physical and chemical properties,spatial structure and subcellular localization of SSR4 protein were analyzed and predicted using online software such as ProtParam,PredictProtein and TMHMM.The recombinant vectors pCMV-Tag4A-SSR4 and pET-GST-Mut were constructed for GST pull-down test in vitro.The recombinant vectors pBiFC-VN173-SSR4 and pBiFC-VC155-Mut were constructed and the bimolecular fluorescence comple-mentary test(BiFC)was performed in cells to verify whether there was direct interaction between APPV-YN-Mut and host protein SSR4 in vitro and in cells.The results showed that SSR4 protein was a hydrophobic stable protein with no transmembrane structure and signal peptide.The second-ary structure was mainly irregular curl,and the tertiary structure was stable,mainly located in the endoplasmic reticulum.GST pull-down and BiFC experiments showed that APPV-YN-Mut interac-ted directly with host protein SSR4 in vitro and in cells.

Objective To report a case of tibial synovial sarcoma and review relevant literature to enhance understanding of this disease.Methods The clinical data of a patient with tibial synovial sarcoma treated at Kaifeng Central Hospital were retrospectively analyzed.A literature search was conducted in domestic and international databases,including China National Knowledge Infrastructure(CNKI),Wanfang Data,PubMed,Web of Science,and Embase,up to July 2024.Relevant literature was comprehensively reviewed to summarize the imaging and pathological characteristics,treatment,and prognosis of synovial sarcoma.Results A 29-year-old female patient was admitted with left lower extremity pain.X-ray examination revealed a proximal tibia space-occupying lesion suggestive of malignancy,and a mid-tibial space-occupying lesion considered benign.Contrast-enhanced computed tomography(CT)and plain magnetic resonance imaging(MRI)of the proximal tibial lesion also suggested malignancy.Ultrasound-guided biopsy of the proximal tibial tumor revealed a poorly differentiated malignant tumor.Immunohistochemistry results indicated monophasic synovial sarcoma,requiring genetic testing for definitive diagnosis.The patient underwent wide resection of the proximal left tibial malignancy with tumor-type artificial joint replacement,combined with curettage and bone cement filling for the left mid-tibial lesion under anesthesia.Postoperative pathology of space-occupying lesions in the proximal tibia confirmed monophasic synovial sarcoma,and fluorescence in situ hybridization(FISH)demonstrated a rupture of the synovial sarcoma translocation gene(SYT)(i.e.,SS18 positive).There was no recurrence or metastasis found in the patient during the reexamination 6 months after postoperative chemotherapy.As of July 2024,15 cases of genetically confirmed primary intraosseous synovial sarcoma have been reported internationally.Symptoms included pain and swelling,with a medical history of 1-2 years.The X-ray and CT findings showed osteolytic destruction with bone cortical discontinuity.In 13 cases,the intraosseous masses extended to the extraosseous area;in 2 cases,punctate calcifications were detected within the masses.Plain MRI scan showed iso-signal or hypo-signal on T1WI and hyper-signal,iso-signal,and hypo-signal on fat-suppressed T2WI,and enhanced MRI scan demonstrated heterogeneous enhancement.Pathological examination showed spindle-shaped cells under microscopy.Immunohistochemistry results showed positive epithelial membrane antigen(EMA),broad-spectrum cytokeratin(AE1/AE3),Ewing's sarcoma marker(CD99),and transducin-like enhancer of Split 1(TLE1).Twelve patients underwent surgical treatment;6 patients received adjuvant chemotherapy after surgery,of whom 4 developed local recurrence or distant metastasis at initial diagnosis,and 3 died during follow-up.Among the 6 patients who did not receive adjuvant chemotherapy,3 suffered from recurrence or distant metastasis.Conclusions Primary intraosseous synovial sarcoma is a rare malignant tumor with non-specific clinical manifestations.Imaging features typically include osteolytic destruction and intraosseous masses extending extraosseously,suggesting an intraosseous origin.Pathology and immunohistochemistry aid diagnosis,but definitive confirmation relies on further genetic testing.At present,the main treatment regimens for synovial sarcoma involve comprehensive therapies such as surgery and adjuvant chemotherapy,and the prognosis of patients is poor.

Objective To investigate the predictive value of artificial intelligence-based Alberta Stroke Program Early CT Score(ASPECTS)combined with diffusion-weighted imaging(DWI)cere-bral infarct volume for poor prognosis in wake-up stroke(WUS)patients.Methods A total of 100 patients with acute ischemic stroke after waking up with unknown time window admitted to Kaifeng Cen-tral Hospital from September 2022 to June 2023 were selected as the research objects.All patients un-derwent emergency non-contrast-enhanced cranial CT and magnetic resonance imaging(MRI)scan,followed by reperfusion therapy.The patients were followed up for 3 months after treatment,and were divided into good prognosis[modified Rankin Scale(mRS)≤2]and poor prognosis groups mRS＞2]according to the mRS score.The baseline data,artificial intelligence ASPECTS,and DWI cerebral in-farct volumes were compared between the two groups.Multivariate logistic regression analysis was used to identify prognostic factors,and receiver operating characteristic(ROC)curves were employed to e-valuate the diagnostic efficacy of artificial intelligence ASPECTS combined with DWI cerebral infarct vol-ume.Results After 3 months of follow-up,the poor prognosis rate of patients was 32.00％(32/100).The artificial intelligence ASPECTS at admission in the poor prognosis group was lower than that in the good prognosis group,and the DWI cerebral infarction volume at admission was larger than that in the good prognosis group,with statistically significant differences(P＜0.05).The results of mul-tivariate logistics analysis showed that age(OR=2.190;95％CI,1.412 to 3.398),blood pressure variability(OR=1.726;95％CI,1.192 to 2.500),homocysteine(OR=1.902;95％CI,1.268 to 2.854),D-dimer(OR=2.275;95％CI,1.274 to 4.064),white blood cell count(OR=2.614;95％CI,1.484 to 4.606),neutrophil-to-lymphocyte ratio(OR=2.921;95％CI,1.350 to 6.323),National Institutes of Health Stroke Scale score(OR=3.171;95％CI,1.754 to 5.731),and DWI infarct volume(OR=3.586;95％CI,1.634 to 7.869)were identified as factors affecting poor prognosis(P＜0.05),while high artificial intelligence ASPECTS was identified as a protective factor(OR=0.534;95％CI,0.352 to 0.810;P＜0.05).The sensitivity,specificity and area under the curve of the combined prediction model were 96.88％,85.29％and 0.947,respectively.The sensitivity and AUC of the combined prediction model were higher than that of the single prediction(P＜0.05),and the specificity was similar to that of the single prediction.Conclusion The com-bined application of artificial intelligence ASPECTS and DWI infarct volume significantly enhances predictive efficacy for poor prognosis in WUS patients,providing a more accurate prognostic evalua-tion tool for clinical decision-making,and it has the value of guiding personalized treatment.