Background Prolonged vibration exposure can lead to vascular endothelial cell dysfunction and cellular injury. However, research on the association between vibration and ferroptosis in vascular endothelial cells remains insufficient. Objective To explore whether occupational vibration exposure is associated with alterations in serum markers related to ferroptosis in patients with hand-arm vibration disease (HAVD), and to further investigate, through in vitro cell experiments, whether vibration exposure may induce ferroptosis in vascular endothelial cells. Methods ①A judgmental sampling method was employed to select 50 workers with HAVD (the HAVD group), 50 vibration-exposed workers without HAVD (the vibration exposure group), and 50 non–hand-transmitted vibration-exposed workers (the control group). Serum iron levels, malondialdehyde (MDA) content, and superoxide dismutase (SOD) levels were measured using serum iron assay kits, MDA detection kits, and SOD detection kits, respectively. One-way analysis of variance and binary logistic regression analysis were performed to examine the relationships between these indicators and HAVD. ②Human umbilical vein endothelial cells (HUVEC) were divided into a vibration group and a control group. The vibration group was subjected to vibration at 120 Hz with an acceleration of 6.5 m·s⁻² and further subdivided into four subgroups: 1 d 2 h, 1 d 4 h, 2 d 2 h, and 2 d 4 h. The control group was treated identically except for vibration exposure. Cellular iron (Fe²⁺) content and reduced glutathione (GSH) levels in HUVEC were measured using ferrous iron colorimetric assay kits and GSH colorimetric assay kits, respectively, to assess the effects of different vibration exposure schedules. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to detect the mRNA expression levels of ferroptosis-related genes, including acyl-CoA synthetase long-chain family member 4 (ACSL4), tumor suppressor protein P53 (P53), ferritin heavy chain 1 (FTH1), and glutathione peroxidase 4 (GPX4). Western blot analysis was conducted to determine the protein expression levels of ferroptosis-related markers in HUVEC. Results ①Compared with the control group, the patients in the HAVD group showed increased serum iron and MDA levels, along with decreased SOD levels (P<0.05). The logistic regression analysis indicated that elevated serum iron levels were significantly associated with an increased risk of HAVD (OR=4.034; 95%CI: 2.063, 7.887), and elevated MDA levels were also associated with an increased risk of HAVD (OR=1.523; 95%CI: 1.026, 1.936). ②Compared with the control group, increased intracellular Fe²⁺ content and decreased GSH content were observed in HUVECs in the 1 d 4 h and 2 d 4 h vibration subgroups (P<0.05). The RT-qPCR results showed that, compared with the control group, vibration exposures of 1 d 4 h and 2 d 4 h significantly upregulated the expression of ACSL4 and P53 (P<0.05), whereas the mRNA expression levels of GPX4 and FTH1 were downregulated in all vibration-exposed endothelial cells (P<0.05). The Western blot results revealed that, compared with the control group, the vibration exposure schedules of 1 d 2 h and 1 d 4 h significantly upregulated the protein expression levels of ACSL4 and P53 (P<0.05), while the vibration exposure schedules of 1 d 4 h, 2 d 2 h, and 2 d 4 h significantly downregulated the protein expression levels of FTH1 and GPX4 (P<0.05). Conclusion Occupational vibration exposure is associated with alterations in iron metabolism and oxidative stress status in workers with HAVD. The in vitro experiments further demonstrates that vibration stimulation induces intracellular iron accumulation and reduces antioxidant capacity in vascular endothelial cells, accompanied by dysregulated expression of ferroptosis-related molecules. These findings suggest that ferroptosis may play a role in vibration-induced vascular injury and the pathogenesis of HAVD.

ObjectiveTo investigate the intervention mechanism of the traditional Chinese medicine Number 2 Feibi recipe （N2FBR） in idiopathic pulmonary fibrosis （IPF）， focusing on its effects on endoplasmic reticulum （ER） stress， apoptosis， stemness maintenance， and regenerative capacity of alveolar type Ⅱ epithelial cells （AT2 cells）， and to validate the modern translational pathway of the theory of "deficiency of Zong Qi leading to pulmonary atelectasis and atrophy". MethodsA mouse model of pulmonary fibrosis was induced by bleomycin （BLM）. Mice were randomly divided into blank control， model， low-， and high-dose N2FBR intervention groups （9.1， 18.2 g·kg^-1）， and prednisolone intervention group （6.5 mg·kg^-1）. Pulmonary histopathological changes and collagen deposition were evaluated using hematoxylin-eosin （HE） and Masson's trichrome staining. Hydroxyproline （HYP） content was measured by the alkaline hydrolysis method. Lung coefficient and pulmonary function parameters were evaluated. The mRNA expression levels of fibrosis-related factors， including collagen type Ⅰ alpha 1 chain （ColIa1）， alpha-smooth muscle actin （α-SMA）， and tissue inhibitor of metalloproteinase 1 （Timp1）， were detected by real-time polymerase chain reaction （Real-time PCR）. Cell apoptosis was assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL） assay. Apoptosis of AT2 cells was further evaluated by double immunofluorescence staining for surfactant protein C （SPC） and cysteine-aspartic protease-3 （Caspase-3）. Endoplasmic reticulum （ER） stress in AT2 cells was examined by double staining for SPC and protein kinase R-like endoplasmic reticulum kinase （PERK）. Ultrastructural changes of ER and lamellar bodies in AT2 cells were observed by transmission electron microscopy （TEM）. The expression levels of key proteins involved in ER stress and apoptosis pathways， including PERK， activating transcription factor 4 （ATF4）， and Caspase-3， were detected by Western blot. Double immunofluorescence staining of SPC and Ki-67 antigen （Ki-67） was performed to evaluate the proliferative capacity of AT2 cells. Lineage tracing technology （labeling AT2 cells with GFP） combined with Krt8 labeling was used to evaluate intermediate differentiation states， and morphological transformation of AT2 cells into alveolar type Ⅰ epithelial cells （AT1） was observed. ResultsBLM-induced mice exhibited significant structural disruption of lung tissue， increased collagen deposition， elevated lung coefficient， decreased pulmonary function， and upregulation of fibrosis-related factors （P<0.01）. High-dose N2FBR treatment significantly ameliorated lung tissue damage and dysfunction， significantly reduced HYP content （P<0.01）， and significantly downregulated ColIa1， α-SMA， and Timp1 expression （P<0.01）. Apoptosis analysis showed increased TUNEL-positive and Caspase-3-positive AT2 cells in the model group， which was significantly reduced by high-dose N2FBR treatment. TEM revealed swollen ER structures in AT2 cells of the model group， which tended to return to normal following treatment. PERK protein staining analysis showed evident ER stress in AT2 cells of the model group， which were markedly alleviated in the treatment group. The expression levels of ER stress-related proteins PERK and ATF4， as well as the apoptosis-related protein Caspase-3， were elevated in the model group and significantly reduced after treatment. TEM also revealed disrupted lamellar body structures in the model group， which tended to recover in the treatment group. Regarding the proliferative capacity of AT2 cells， the proportion of Ki-67⁺SPC⁺ AT2 cells significantly increased in the treatment group （P<0.01）. Lineage tracing showed that the proportion of keratin 8-positive green fluorescent protein-positive （Krt8⁺GFP⁺） cells increased in the model group， indicating differentiation arrest. This proportion was significantly reduced in the treatment group， and the morphology of GFP⁺ cells exhibited a flattened， extended shape， suggesting restored differentiation toward AT1 cells. ConclusionN2FBR alleviates ER stress in AT2 cells， reduces AT2 cell apoptosis， restores lamellar body structure and function， enhances proliferation activity， and alleviates differentiation arrest to promote differentiation into AT1 cells， thereby repairing the alveolar epithelium and effectively blocking the progression of pulmonary fibrosis. Its traditional Chinese medicine mechanism of "replenishing Zong Qi， harmonizing Qi and blood， and unblocking pulmonary meridians" closely aligns with the modern regulatory pathway of AT2 stem cells， providing a novel theoretical basis and experimental evidence for the intervention of IPF with traditional Chinese medicine.

ObjectiveTo investigate the intervention mechanism of the traditional Chinese medicine Number 2 Feibi recipe （N2FBR） in idiopathic pulmonary fibrosis （IPF）， focusing on its effects on endoplasmic reticulum （ER） stress， apoptosis， stemness maintenance， and regenerative capacity of alveolar type Ⅱ epithelial cells （AT2 cells）， and to validate the modern translational pathway of the theory of "deficiency of Zong Qi leading to pulmonary atelectasis and atrophy". MethodsA mouse model of pulmonary fibrosis was induced by bleomycin （BLM）. Mice were randomly divided into blank control， model， low-， and high-dose N2FBR intervention groups （9.1， 18.2 g·kg^-1）， and prednisolone intervention group （6.5 mg·kg^-1）. Pulmonary histopathological changes and collagen deposition were evaluated using hematoxylin-eosin （HE） and Masson's trichrome staining. Hydroxyproline （HYP） content was measured by the alkaline hydrolysis method. Lung coefficient and pulmonary function parameters were evaluated. The mRNA expression levels of fibrosis-related factors， including collagen type Ⅰ alpha 1 chain （ColIa1）， alpha-smooth muscle actin （α-SMA）， and tissue inhibitor of metalloproteinase 1 （Timp1）， were detected by real-time polymerase chain reaction （Real-time PCR）. Cell apoptosis was assessed using the terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL） assay. Apoptosis of AT2 cells was further evaluated by double immunofluorescence staining for surfactant protein C （SPC） and cysteine-aspartic protease-3 （Caspase-3）. Endoplasmic reticulum （ER） stress in AT2 cells was examined by double staining for SPC and protein kinase R-like endoplasmic reticulum kinase （PERK）. Ultrastructural changes of ER and lamellar bodies in AT2 cells were observed by transmission electron microscopy （TEM）. The expression levels of key proteins involved in ER stress and apoptosis pathways， including PERK， activating transcription factor 4 （ATF4）， and Caspase-3， were detected by Western blot. Double immunofluorescence staining of SPC and Ki-67 antigen （Ki-67） was performed to evaluate the proliferative capacity of AT2 cells. Lineage tracing technology （labeling AT2 cells with GFP） combined with Krt8 labeling was used to evaluate intermediate differentiation states， and morphological transformation of AT2 cells into alveolar type Ⅰ epithelial cells （AT1） was observed. ResultsBLM-induced mice exhibited significant structural disruption of lung tissue， increased collagen deposition， elevated lung coefficient， decreased pulmonary function， and upregulation of fibrosis-related factors （P<0.01）. High-dose N2FBR treatment significantly ameliorated lung tissue damage and dysfunction， significantly reduced HYP content （P<0.01）， and significantly downregulated ColIa1， α-SMA， and Timp1 expression （P<0.01）. Apoptosis analysis showed increased TUNEL-positive and Caspase-3-positive AT2 cells in the model group， which was significantly reduced by high-dose N2FBR treatment. TEM revealed swollen ER structures in AT2 cells of the model group， which tended to return to normal following treatment. PERK protein staining analysis showed evident ER stress in AT2 cells of the model group， which were markedly alleviated in the treatment group. The expression levels of ER stress-related proteins PERK and ATF4， as well as the apoptosis-related protein Caspase-3， were elevated in the model group and significantly reduced after treatment. TEM also revealed disrupted lamellar body structures in the model group， which tended to recover in the treatment group. Regarding the proliferative capacity of AT2 cells， the proportion of Ki-67⁺SPC⁺ AT2 cells significantly increased in the treatment group （P<0.01）. Lineage tracing showed that the proportion of keratin 8-positive green fluorescent protein-positive （Krt8⁺GFP⁺） cells increased in the model group， indicating differentiation arrest. This proportion was significantly reduced in the treatment group， and the morphology of GFP⁺ cells exhibited a flattened， extended shape， suggesting restored differentiation toward AT1 cells. ConclusionN2FBR alleviates ER stress in AT2 cells， reduces AT2 cell apoptosis， restores lamellar body structure and function， enhances proliferation activity， and alleviates differentiation arrest to promote differentiation into AT1 cells， thereby repairing the alveolar epithelium and effectively blocking the progression of pulmonary fibrosis. Its traditional Chinese medicine mechanism of "replenishing Zong Qi， harmonizing Qi and blood， and unblocking pulmonary meridians" closely aligns with the modern regulatory pathway of AT2 stem cells， providing a novel theoretical basis and experimental evidence for the intervention of IPF with traditional Chinese medicine.

Objective: To assess the current status of bacterial detection capabilities in various blood collection and supply and related laboratories across China, and to identify key factors affecting the consistency of test results. Methods: A pooled analysis was conducted on data from 21 external quality assessment (EQA) rounds for blood bacterial detection carried out by the China International Transfusion Infection Prevention and Control (CITIC) project from 2019 to 2025. The study covered three types of laboratories-blood centers, central blood stations, and commercial laboratories—across 23 provincial-level administrative regions in China. Statistics were compiled on the number of participating laboratories, and the concordance rates were calculated for different institution types, different automated blood culture systems, different bacterial concentrations, and different strains. Non-standard reporting issues were also reviewed, and statistical methods were applied for analysis. Results: Over the seven-year period, the number of participating laboratories increased from 161 to 236, with an average annual growth rate of 6.58%, and the annual concordance rates ranged from 82.61% to 94.92%. The overall laboratory concordance rates for the three types of participating laboratories were all>89.0% (P>0.05), while commercial laboratories showed a significant year-by-year increase (70.97%-100%, P<0.05). The concordance rates of automated blood culture systems from eight manufacturers showed no significant differences (97.98%-100%, P>0.05), indicating stable performance across all devices. The overall sample concordance rate was 98.88%, with negative samples showing a lower rate than positive samples (97.97% vs 99.14%); positive sample rates increased with higher concentrations; and low-concentration Gram-negative bacterial samples had a lower concordance rate than Gram-positive ones (93.15% vs 100%). A total of 50 instances of non-standard result reporting were identified, with incorrect time units accounting for the highest proportion (52.0%). Conclusion The participation scale and overall testing proficiency of blood collection and supply and related laboratories nationwide have improved year by year, and all types of automated blood culture devices can meet the requirements for blood bacterial screening. Detection of negative and low-concentration positive samples remains a weak link in current bacterial EQA, and the standardization of laboratory data reporting requires further strengthening. Continuous: external quality assessment, targeted training, and standardized reporting procedures can effectively enhance the homogenization level of blood bacterial testing across the country and ensure the safety of clinical transfusion.

OBJECTIVE: To screen out the key metabolites related to diabetic foot (DF) by integrating genome-wide association studies (GWAS) and metabolome genome-wide association studies (mGWAS). METHODS: The literature databases such as PubMed and China national knowledge infrastructure(CNKI), as well as genomics databases such as PAN UKBB, FinnGen, and IEU Open GWAS were systematically retrieved from database estobilishment to November 2024 on DF-related single nucleotide polymorphisms and genome-wide association studies. DF-single nucleotide polymorphism-metabolite network was constructed by mGWAS package and mGWAS-Explorer platform. The causal relationship between key factors was evaluated by two-sample Mendelian randomization. The genetic correlation between DF and 575 metabolites (source:IEU Open GWAS) was evaluated by linkage disequilibrium score regression. In vitro experiments were conducted to induce injury of human umbilical vein endothelial cells with 30 mM glucose and intervene with 20 μM γ-tocopherol. Changes in cell migration, scratch healing and tube formation function were detected. RESULTS: Twenty-senen literatures on single nucleotide polymorphism literatures and 3 studies on GWAS were included. Genetic analysis results showed DF-related single nucleotide polymorphisms were enriched in vascular endothelial dysfunction-related pathways (such as fluid shear stress and atherosclerosis). The results of metabolic network analysis screened out 19 associated metabolites, among which 12 such as γ -tocopherol and pyruvate had significant genetic correlations with DF. Mendelian randomization suggested matrix metalloproteinase-9(MMP-9) might be a potential driver of DF (β=0.658, P=0.063 8), and the occurrence of DF could reduce the level of high-density lipoprotein (β=-0.002, P=0.015 2). The results of in vitro experiments confirmed that γ -tocopherol could improve endothelial dysfunction induced by high glucose, specifically manifested as an increase in the number of cell migrations, improvement in the scratch healing rate, and recovery of tubule formation ability (P<0.05). CONCLUSION DF has a genetic basis centered on vascular endothelial dysfunction, and its occurrence can lead to further metabolic disorders. The key single nucleotide polymorphism loci integrated provided molecular markers for the risk stratification of foot ulcers in diabetic patients. In addition, γ -tocopherol has demonstrated clinical application potential as a therapeutic drug for DF by significantly improving the function of vascular endothelial cells in a high-glucose environment.
Humans ; Diabetic Foot/drug therapy* ; Polymorphism, Single Nucleotide ; Genome-Wide Association Study ; Genomics ; Metabolomics ; Metabolome

OBJECTIVE: To investigate the accuracy and safety of pedicle screw placement using 3D-printed auxiliary guides in scoliosis correction surgery for adolescents. METHODS: A retrospective analysis was conducted on the clinical data of 51 patients who underwent posterior scoliosis correction surgery from January 2020 to March 2023. Among them, there were 35 cases of adolescent idiopathic scoliosis and 16 cases of congenital scoliosis. The patients were divided into two groups based on the auxiliary tool used:the 3D-printed auxiliary guide screw placement group (3D printing group) and the free-hand screw placement group (free-hand group, without auxiliary tools). The 3D printing group included 32 patients (12 males and 20 females) with an average age of (12.59±2.60) years;the free-hand group included 19 patients (7 males and 12 females) with an average age of (14.58±3.53) years. The two groups were compared in terms of screw placement accuracy and safety, spinal correction rate, intraoperative blood loss, number of intraoperative fluoroscopies, operation time, hospital stay, and preoperative and last follow-up scores of the Scoliosis Research Society-22 (SRS-22) questionnaire. RESULTS: A total of 707 pedicle screws were placed in the two groups, with 441 screws in the 3D printing group and 266 screws in the free-hand group. All patients in both groups successfully completed the surgery. There was a statistically significant difference in operation time between the two groups (P<0.05). The screw placement accuracy rate of the 3D printing group was 95.46% (421/441), among which the Grade A placement rate was 89.34% (394/441);the screw placement accuracy rate of the free-hand group was 86.47% (230/266), with a Grade A placement rate of 73.31% (195/266). There were statistically significant differences in the accuracy of Grade A, B, and C screw placements between the two groups (P<0.05), while no statistically significant differences were observed in intraoperative blood loss, number of fluoroscopies, correction rate, or hospital stay (P>0.05). In the SRS-22 questionnaire scores, the scores of functional status and activity ability, self-image, mental status, and pain of patients in each group at the last follow-up were significantly improved compared with those before surgery (P<0.05), but there were no statistically significant differences in all scores between the two groups (P>0.05). CONCLUSION In scoliosis correction surgery, compared with traditional free-hand screw placement, the use of 3D-printed auxiliary guides for screw placement significantly improves the accuracy and safety of screw placement and shortens the operation time.
Humans ; Male ; Scoliosis/surgery* ; Female ; Adolescent ; Printing, Three-Dimensional ; Retrospective Studies ; Pedicle Screws ; Child

PURPOSE: To comprehensively analyze the geographic and temporal trends of foot fracture, understand its health burden by age, sex, and sociodemographic index (SDI), and explore its leading causes from 1990 to 2019. METHODS: The datasets in the present study were generated from the Global Burden of Diseases Study 2019, which included foot fracture data from 1990 to 2019. We extracted estimates along with the 95% uncertainty interval (UI) for the incidence and years lived with disability (YLDs) of foot fracture by location, age, gender, and cause. The epidemiology and burden of foot fracture at the global, regional, and national level was exhibited. Next, we presented the age and sex patterns of foot fracture. The leading cause of foot fracture was another focus of this study from the viewpoint of age, sex, and location. Then, Pearson's correlations between age-standardized rate (ASR), SDI, and estimated annual percentage change were calculated. RESULTS: The age-standardized incidence rate was 138.68 (95% UI: 104.88 - 182.53) per 100,000 persons for both sexes, 174.24 (95% UI: 134.35 - 222.49) per 100,000 persons for males, and 102.19 (95% UI: 73.28 - 138.00) per 100,000 persons for females in 2019. The age-standardized YLDs rate was 5.91 (95% UI: 3.58 - 9.25) per 100,000 persons for both genders, 7.35 (95% UI: 4.45 - 11.50) per 100,000 persons for males, and 4.51 (95% UI: 2.75 - 7.03) per 100,000 persons for females in 2019. The global incidence and YLDs of foot fracture increased in number and decreased in ASR from 1990 to 2019. The global geographical distribution of foot fracture is uneven. The incidence rate for males peaked at the age group of 20 - 24 years, while that for females increased with advancing age. The incidence rate of older people was rising, as younger age incidence rate declined from 1990 to 2019. Falls, exposure to mechanical forces, and road traffic injuries were the 3 leading causes of foot fracture. Correlations were observed between ASR, estimated annual percentage change, and SDI. CONCLUSIONS The burden of foot fracture remains high globally, and it poses an enormous public health challenge, with population aging. It is necessary to allocate more resources to the high-risk populations. Targeted realistic intervention policies and strategies are warranted.
Humans ; Male ; Female ; Incidence ; Fractures, Bone/epidemiology* ; Middle Aged ; Adult ; Global Health ; Aged ; Global Burden of Disease ; Adolescent ; Child ; Young Adult ; Foot Injuries/epidemiology* ; Cost of Illness ; Child, Preschool ; Aged, 80 and over ; Infant

This study was conducted retrospectively on a cohort of 68 patients with steroid 5 α-reductase 2 (SRD5A2) deficiency and 46,XY disorders of sex development (DSD). Whole-exon sequencing revealed 28 variants of SRD5A2 , and further analysis identified seven novel mutants. The preponderance of variants was observed in exon 1 and exon 4, specifically within the nicotinamide adenine dinucleotide phosphate (NADPH)-binding region. Among the entire cohort, 53 patients underwent initial surgery at Sichuan Provincial People's Hospital (Chengdu, China). The external genitalia scores (EGS) of these participants varied from 2.0 to 11.0, with a mean of 6.8 (standard deviation [s.d.]: 2.5). Thirty patients consented to hormone testing. Their average testosterone-to-dihydrotestosterone (T/DHT) ratio was 49.3 (s.d.: 23.4). Genetic testing identified four patients with EGS scores between 6 and 9 as having this syndrome; and their T/DHT ratios were below the diagnostic threshold. Furthermore, assessments conducted using the crystal structure of human SRD5A2 have provided insights into the potential pathogenic mechanisms of these novel variants. These mechanisms include interference with NADPH binding (c.356G>C, c.365A>G, c.492C>G, and c.662T>G) and destabilization of the protein structure (c.727C>T). The c.446-1G>T and c.380delG variants were verified to result in large alterations in the transcripts. Seven novel variations were identified, and the variant database for the SRD5A2 gene was expanded. These findings contribute to the progress of diagnostic and therapeutic approaches for individuals with SRD5A2 deficiency.
Humans ; 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/genetics* ; Disorder of Sex Development, 46,XY/blood* ; Male ; Membrane Proteins/genetics* ; Child, Preschool ; Child ; Retrospective Studies ; Adolescent ; Female ; Mutation ; Testosterone/blood* ; Infant ; Dihydrotestosterone/blood*

Ureaplasma urealyticum (UU) is one of the most commonly occurring pathogens associated with genital tract infections in infertile males, but the impact of seminal UU infection in semen on intrauterine insemination (IUI) outcomes is poorly understood. We collected data from 245 infertile couples who underwent IUI at The First Affiliated Hospital of USTC (Hefei, China) between January 2021 and January 2023. The subjects were classified into two groups according to their UU infection status: the UU-positive group and the UU-negative group. We compared semen parameters, pregnancy outcomes, and neonatal birth outcomes to investigate the impact of UU infection on IUI outcomes. There were no significantly statistical differences in various semen parameters, including semen volume, sperm concentration, total and progressive motility, sperm morphology, leukocyte count, the presence of anti-sperm antibody, and sperm DNA fragmentation index (DFI), between the UU-positive and UU-negative groups of male infertile patients (all P > 0.05). However, the high DNA stainability (HDS) status of sperm differed between the UU-positive and UU-negative groups, suggesting that seminal UU infection may affect sperm nuclear maturation ( P = 0.04). Additionally, there were no significant differences in pregnancy or neonatal birth outcomes between the two groups (all P > 0.05). These results suggest that IUI remains a viable and cost-effective option for infertile couples with UU infection who are facing infertility issues.
Humans ; Male ; Ureaplasma Infections/complications* ; Female ; Infertility, Male/therapy* ; Ureaplasma urealyticum/isolation & purification* ; Pregnancy ; Adult ; Pregnancy Outcome ; Semen Analysis ; Insemination, Artificial ; Semen/microbiology* ; China