Background In recent years, the increasingly widespread application of nuclear and medical radiation technologies has resulted in a large number of occupational populations exposed to low-dose ionizing radiation (LDIR). At present, there is no consistent conclusion on the effects of long-term exposure to LDIR on the metabolic health of the occupational population. Objective To explore the association between long-term exposure to LDIR and metabolic syndrome (MetS) among medical radiologists. Methods A cross-sectional study was conducted to enroll 6431 medical radiologists who ordered occupational health checkups from January 2022 to December 2023, and basic information such as demographic characteristics, occupational characteristics, lifestyles, and dietary habits was collected through questionnaires. Physical examinations were conducted using a standardized protocol. Individual dose equivalents of occupational external exposure were monitored by dosimeters worn by medical radiologists. Logistic regression model was used for identifying influencing factors of MetS and sensitivity analysis, and restricted cubic spline model was used to explore the dose-response relationship between cumulative effective dose and MetS. Two-stage linear regression was used to evaluate threshold effect of association between cumulative effective dose and MetS. Results The positive rate of MetS was 13.6% (877/6431) among the enrolled 6431 study participants. The logistic regression showed that gender, age, monthly income, body mass index (BMI), cumulative effective dose, and smoking were influencing factors for MetS. The risk of MetS was higher in males (OR=1.511, 95%CI: 1.209, 1.888); using the < 30 years old group as reference, the risk of MetS was higher in the 30-39 years old (OR=1.509, 95%CI: 1.095, 2.079), 40-49 years old (OR=2.214, 95%CI: 1.551, 3.161), and ≥50 years old (OR=3.480, 95%CI: 2.338, 5.181) groups; using the <10000 yuan group as reference, the risk of MetS was lower in the group with a monthly income of 10000-14999 yuan (OR=0.715, 95%CI: 0.582, 0.878); the risk of MetS was higher in the BMI ≥ 24 kg·m⁻² group (OR=7.548, 95%CI: 6.223, 9.156); using the < 0.76 mSv group as reference, the risk of MetS was higher in the cumulative effective dose of 0.76-2.73 mSv group (OR=1.270, 95%CI: 1.017, 1.586); the risk of MetS was higher in the smoking group (OR=1.734, 95%CI: 1.428, 2.107). The results of restricted cubic spline showed that the cumulative effective dose was nonlinearly correlated with MetS (P _{non-linearity}=0.028), with an inflection point of 1.25 mSv. The risk of developing MetS increased by 34.1% for each unit increase in cumulative effective dose up to 1.25 mSv, whereas above 1.25 mSv, the statistical association was not significant. The sensitivity analysis results showed that after excluding the self-reported hypertensive and diabetic patients, the cumulative effective dose 0.76-2.73 mSv group still had an increased risk of developing MetS compared with the < 0.76 mSv group (P < 0.05), and the results were robust. Conclusion Among medical radiologists, male, age, BMI, and smoking are positively correlated with MetS, and monthly income is negatively correlated with MetS; cumulative effective dose is non-linearly correlated with MetS among medical radiologists.

L-phosphinothricin (L-PPT) is an efficient broad-spectrum herbicide. To realize the multi-enzyme catalytic preparation of L-PPT, we constructed an engineered strain Escherichia coli YM-1 for efficient expression of D-amino acid transaminase, which could catalyze the generation of the intermediate 2-oxo-4-[(hydroxymethylphosphonyl)] butyric acid (PPO) from D-phosphinothricin (D-PPT). In addition, E. coli pLS was constructed to co-express glutamate dehydrogenase and glucose dehydrogenase, which not only catalyzed the generation of L-PPT from PPO but also regenerated the coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). A fed-batch fermentation process was then established for E. coli YM-1 and pLS, and the apparent activities of D-amino acid transaminase and glutamate dehydrogenase were increased by 22.68% and 100.82%, respectively, compared with those in shake flasks. The process parameters were optimized for the catalytic preparation of L-PPT by whole-cell cascade of E. coli YM-1 and pLS with D, L-PPT as the substrate. After reaction for 8 h, 91.36% conversion of D-PPT was achieved, and the enantiomeric excess of L-PPT reached 90.22%. The findings underpin the industrial production of L-PPT.
Escherichia coli/enzymology* ; Aminobutyrates/metabolism* ; Glutamate Dehydrogenase/biosynthesis* ; Glucose 1-Dehydrogenase/biosynthesis* ; Herbicides/metabolism* ; Multienzyme Complexes/metabolism* ; Transaminases/metabolism* ; Phosphinic Acids/metabolism*

OBJECTIVE To systematically evaluate the repair strategies for temporal bone-parotid composite defects,compare the clinical applicability of local muscle flaps and free flaps,and provide references for optimizing the reconstruction of complex head and neck defects.METHODS We retrospectively analyzed the medical records of 17 patients with postoperative defects in the temporal bone-parotid region treated at Beijing Tongren Hospital,Capital Medical University,between January 2018 and June 2023.There were 11 males and 6 females,with a median age of 58 years(range:42-72 years).All patients had undergone radical resection.Defects were reconstructed with local flaps in 13 cases(temporalis muscle flap,n=6;sternocleidomastoid flap,n=3;submental platysma flap,n=2;submental island flap,n=2)and with free flaps in 4 cases(anterolateral thigh fascial flap,n=1;anterolateral thigh flap,n=1;free abdominal adipofascial flap,n=2).RESULTS The primary diseases of the 17 patients were malignant tumors of the external auditory canal and parotid gland(6 cases of squamous cell carcinoma,6 cases of adenoid cystic carcinoma,and 3 cases of ductal carcinoma).All flaps survived completely.One patient with temporalis muscle flap repair developed postoperative wound infection,which healed after debridement and dressing change.The median follow-up period was 16 months(4-29 months).Two cases(11.8%)of external auditory canal squamous cell carcinoma had local recurrence,one case(5.9%)of parotid ductal carcinoma developed pulmonary metastasis 9 months after surgery and died at 15 months.The remaining 14 cases(82.4%)were tumor-free survivors.Functional evaluation showed that the local tissue flap group had a shorter repair time,but was limited by muscle flap rotation arc;the free flap group could accurately match the defect shape,but the surgical time was prolonged to 3.5-4.5 hours.Fourteen cases(82.4%)received postoperative adjuvant radiotherapy.None of the tissue flaps developed radiation necrosis after radiotherapy.CONCLUSION Temporal bone-parotid composite defects need to balance the dual requirements of surgical cavity coverage and cosmetic repair.Local muscle flaps are easy to operate and have reliable blood supply,suitable for small and medium-sized defects;free tissue flaps have better shape adaptability in complex three-dimensional defect reconstruction,but require microsurgical technical support.The repair plan should be comprehensively decided based on the defect range,vascular conditions,and radiotherapy plan.The data of this group confirmed that both techniques can achieve stable therapeutic effects.

Objective To analyze the changes of serum inhibin B(INHB),anti-Müllerian hormone(AMH)and sex hormone levels in patients with infertility caused by polycystic ovary syndrome(PCOS).Methods A total of 302 patients with infertility caused by PCOS admitted to the hospital from June 2021 to June 2023 were selected as the experimental group,and 300 healthy women of childbearing age with normal menstrual cycle were selected as the control group.The levels of serum INHB,AMH and sex hormone indexes[serum luteinizing hormone(LH),follicle stimulating hormone(FSH),prolactin(PRL),progesterone(P),testoster-one(T),estradiol(E2)]and homeostasis model assessment of insulin resistance(HOMA-IR)were observed and compared between the two groups.Results The serum levels of AMH,INHB and HOMA-IR in test group were significantly higher than those in control group,with statistical significance(P＜0.05).Serum levels of LH/FSH,PRL,T and P in experimental groups were significantly higher than those in control group,and serum E2 levels were significantly lower than those in control group,with statistical significance(P＜0.05).With the passage of treatment time,serum AMH,INHB,LH/FSH,PRL,T and P levels gradually decreased,and E2 levels gradually increased(P＜0.05).The area under the curve(AUC)of AMH and INHB combined detection in the diagnosis of infertility caused by PCOS was 0.905,which was higher than the AUC of AMH or INHB detection alone(P＜0.05).Serum AMH and INHB levels were positively correlated with FSH,LH,T and HOMA-IR,PRL,P(P＜0.05),and negatively correlated with serum E2 levels(P＜0.05).Conclusion The levels of AMH and INHB in serum of infertility patients caused by PCOS are significantly increased,and AMH and INHB are correlated with sex hormone levels.Detection of serum AMH,INHB and sex hormone levels is helpful for the diagnosis of infertility caused by PCOS.

ObjectiveTo determine the serum antibody level and risk factors in the adolescent population in a county in Zhejiang Province， following the immunization with inactivated COVID-19 vaccine， and to construct a prediction model for antibody concentration. MethodsWe conducted the study in a county in Zhejiang Province， employing a stratified cluster random sampling strategy in school children who had received the inactivated COVID-19 vaccine. Data on gender， age， type of vaccine， and time of vaccination was collected. Serum samples were also collected to test for anti-S and N IgG antibody against the SARS-CoV-2 by using chemiluminescent immunoassay （CLIA）. Risk factors were determined to construct a prediction model for antibody concentration. ResultsThe IgG antibody concentration was significantly higher in girls， those who received two doses， and those who had simply received the KX vaccine . It decreased with age and time interval between the sampling and last vaccination. The prediction model constructed by random forest regression in the study had a better model fit and predictive ability than that by the multivariable linear stepwise regression. ConclusionGender， age， vaccination dose， type of vaccine， and time of vaccination are associated with vaccination effectiveness of inactivated COVID-19 vaccines in adolescents. Prediction model could predict the antibody level in the vaccinated population， which can provide a new tool for better evaluation of vaccination effectiveness against emerging infectious diseases in future.

Objective To perform laboratory detection and molecular traceability analysis on a case of imported kala-azar in Shenzhen to determine the infection strain. Methods Bone marrow puncture fluid and blood samples from a case of kala-azar in Shenzhen were collected for laboratory tests. The patient's bone marrow puncture fluid smears were stained with Giemsa and examined under a microscope. Blood samples were examined for antibodies using the rk39 visceral leishmania rapid diagnostic reagent. Whole blood DNA was extracted, and the ITS-1 sequence was amplified by PCR, sequenced and aligned, and a phylogenetic tree was constructed based on the ITS-1 sequence. Results Microscopic examination of the patient's bone marrow smears revealed a large number of Leishmania amastigotes without flagella, confirming the diagnosis of kala-azar. The patient's blood was tested positive with the rk39 rapid diagnostic reagent, and PCR amplification yielded an ITS-1 gene product sequence that matched the expected size. Sequence alignment with the NCBI database showed 100% sequence similarity with the ITS-1 gene sequence of Leishmania infantum, confirming the infecting strain as Leishmania infantum. Phylogenetic tree construction of the amplified ITS-1 sequence revealed clustering into a clade with Leishmania infantum , and close to KC347299, one of the reference sequence selected. Conclusions The case of kala-azar in Shenzhen was caused by Leishmania infantum. Kala-azar still occurs in China, so the diagnostic technology of medical personnel in non-epidemic areas should be strengthened so that they can actively use new diagnostic technologies to assist in diagnosis, thus improving their prevention and control ability of Leishmania parasites.

Abstract: Objective　To analyze and understand the mutations of drug resistance genes in imported Plasmodium falciparum in Shenzhen, aiming to assess the efficacy of antimalarial drugs and guide effective drug use. Methods A total of 85 samples from individuals with imported Plasmodium falciparum confirmed by fluorescence quantitative polymerase chain reaction (PCR) in Shenzhen from 2022 to 2023 were collected and genomic DNA was extracted. Nested PCR was used to amplify resistance genes, including Plasmodium falciparum Kelch 13 (PfK13), multidrug resistance gene 1 (Pfmdr1), chloroquine resistance transporter (Pfcrt), dihydrofolate reductase (Pfdhfr), and dihydropteroate synthase (Pfdhps) genes. Bidirectional sequencing was conducted, and mutations in these resistance genes were analyzed using MEGA11.06 software. Results　The study found one missense mutation (S549P) and four synonymous mutations in PfK13. For Pfmdr1, 62.69% of the samples showed Y184F mutation, and no N86Y mutation was detected. No mutations at positions 72 and 73 were detected in the Pfcrt gene, while mutations at M74I, N75E, and K76T accounted for 17.46%, 15.87%, and 15.87%, respectively. The wild-type of Pfcrt gene is dominant (82.54%, 52), followed by the triple mutant I74E75T76 (15.87%, 10). The most common mutation type for Pfdhfr is I51R59N108 (91.78%, 67), followed by the wild type (2.74%, 2). More than half (60.32%, 38) of the Pfdhps samples were wild-type, with single mutation K540E being the most common mutation type. S436A, G437A, K540E, A581G, A613S, I431V, G556K, and G579E site mutations were detected. Among the Pfdhfr-Pfdhps combination mutations, I51R59N108-E540 was the most frequent combination mutation (11.48%), with 59.02% of samples showing solitary Pfdhfr mutations. Conclusions In this study, PfK13 mutation rates were low, with no reported resistance mutations. The Y184F mutation emerged as the dominant Pfmdr1 mutation, with no detection of N86Y. For Pfcrt, the wild-type was dominant, followed by the I74E75T76 triple mutation variant. Triple mutant I51R59N108 of Pfdhfr was very common, and our study did not find Pfdhfr Pfdhps completely resistant and super resistant mutants, but there were other quintuple and septuple mutant types. In the future, it is crucial to continue to strengthen the monitoring of malaria parasite resistance genes and to further integrate in vivo efficacy monitoring to effectively guide clinical drug use.

Objective To evaluate the accuracies of two-dimensional ultrasound(2D-US)and three-dimensional ultrasound virtual organ computer-aided analysis(3D-VOCAL)in measuring uterine myoma volume(UMV).Methods Forty-five patients who underwent surgical treatment for uterine myoma at Longyan First Hospital,Fujian Medical University from October 2022 to April 2023 were selected.Preoperative measurements of UMV were performed using 2D-US and 3D-VOCAL,and the measurement results were compared with the actual UMV after surgical resection to assess the accuracies and repeatabilities of the two ultrasound techniques in measuring UMV.Results The UMV measurement consistency of 3D-VOCAL(ICC=0.992)was higher than that of 2D-US(ICC=0.976),and the ICC values of 3D-VOCAL were higher than those of 2D-US in UM of different sizes(all P<0.001).Statistically significant differences among 2D-US,3D-VOCAL and postoperative measurement results was found in UM with a maximum diameter≥8 cm(P<0.05),but not in UMV and UM with a maximum diameter<8 cm(P>0.05),and the further analysis showed that in UM with a maximum diameter≥8 cm,the UMV measured by 2D-US differed from postoperative measurement results(P<0.05).The differences between 3D-VOCAL measurement results and postoperative measurement results were trivial(P>0.05).There were greater intra-and interobserver agreements by 3D-VOCAL than 2D-US in UMV measurement.Conclusion 3D-VOCAL which is superior to 2D-US in preoperative UMV measurement is a simple,efficient,and reliable method,and it can provide theoretical bases for clinical follow-up.

Cancer patients generally suffer from depression,and long-term depression may exacerbate fatigue,sleep disor-ders,pain,and psychological distress,affecting the overall treatment effectiveness of cancer patients and ultimately impacting their quality of life and prognosis.Therefore,this article mainly reviews the research status and influencing factors of depression trajectories in cancer patients,providing reference for precise and personalized depression management for cancer patients.

Objective To analyze the prevalence status,influencing factors,and differences among different school age groups of myopia in children and adolescents in Ningxia Hui Autonomous Region.Methods From September to De-cember 2019,inYinchuan,Wuzhong,Shizuishan,Guyuan and Zhongwei of Ningxia,8 primary schools,6 junior high schools,6 senior high schools and 4 universities were randomly selected by stratified cluster random sampling.Five classes were se-lected from each grade of primary school,and four classes were selected from each grade of junior high school to university.All students in the selected classes were included in the study.A total of 14 211 students were selected for questionnaire sur-vey,physical examination and visual acuity measurement.The influencing factors of myopia in children of different grades were analyzed using the least absolute shrinkage and selection operator(LASSO)and logistic regression,and the model with the smallest Bayesian information criterion(BIC)was selected as the optimal model.Results The detection rate of myopia in children and adolescents in Ningxia Hui Autonomous Region was 70.3％.The detection rate of myopia in girls was higher than that in boys,and that in cities was higher than that in towns,with statistically significant differences(both P＜0.001).Compared with primary school students,the detection rate of myopia in junior high school students,senior high school students and college students gradually increased,and that in the college students was the highest,with statistically signifi-cant differences among different grades(all P＜0.001).The LASSO-logistic regression analysis of the influencing factors of myopia showed that urban and rural areas,gender,age,whether or not to wear glasses at present,the number of daily break exercises,whether or not to actively participate in physical activities,and whether or not to maintain regular exercises in the past 6 months were the influencing factors of myopia in primary school students(all P＜0.05).Gender and whether or not to wear glasses at present were the influencing factors of myopia in junior high school students and senior high school students(all P＜0.05).Whether or not to wear glasses at present was the influencing factor of myopia in college students(P＜0.05).Conclusion The detection rate of myopia in children and adolescents in Ningxia Hui Autonomous Region is high,and there are significant differences in the influencing factors of myopia among different age groups of children and adolescents.Wear-ing glasses is a protective factor to control myopia.Targeted health education on vision should be provided based on the aca-demic stage of children and adolescents to enhance their awareness of health care and improve their visual health.