Polyethylene terephthalate (PET) fibers are characterized by exceptional mechanical strength, and textiles blended with cotton fibers combine both comfort and durability, showcasing widespread use in daily applications. However, improper disposal of discarded polyester-cotton textiles has resulted in severe environmental pollution, necessitating urgent and effective mitigation strategies. Enzymatic recycling of textiles offers superior environmental benefits and holds greater potential for industrial applications than alternative recycling methods. This study aims to explore a large-scale solution for the treatment of waste textiles, particularly addressing the challenge of resource recovery from polyester-cotton blended fabrics. An innovative enzymatic depolymerization process has been developed to achieve the recovery of high-purity terephthalic acid monomers. Experiments were conducted on three different textile blends with polyester-to-cotton ratios of 65/35, 70/30, and 80/20, and the influences of different colors on the process were investigated. Initially, the textiles were pretreated through mechanical grinding, which was followed by depolymerization of cotton fibers with commercial cellulase. The crystallinity of PET in the textiles was reduced through a rapid heating and cooling process. Subsequently, the PET was depolymerized by the engineered PET hydrolase. The results demonstrated that after decolorization and separation of terephthalic acid (TPA) from the reaction system, the monomer recovery rates for the three textile blends (65/35, 70/30, and 80/20) reached 90%, 91%, and 92%, respectively. Characterization analysis by nuclear magnetic resonance (NMR) confirmed that the purity of the recovered TPA was greater than 99%. In conclusion, the fully enzymatic recycling process developed in this study shows considerable promise for large-scale industrial applications and is anticipated to significantly advance the adoption and development of enzymatic recycling technologies for PET in industrial processes.
Phthalic Acids/chemistry* ; Polyesters/chemistry* ; Textiles ; Cotton Fiber ; Polyethylene Terephthalates/chemistry* ; Cellulase/chemistry* ; Recycling/methods* ; Polymerization

Objective: To understand the dose response relationship between urinary fluoride and dental fluorosis among children from drinking water borne endemic fluorosis areas in Tianjin, so as to provide a scientific basis for assessing fluoride exposure risk among children from endemic areas and establishing reference values for urinary fluoride. Methods: From January to December 2024, 83 endemic villages were selected in Tianjin. A total of 2 382 children aged 8-12 years from these villages underwent dental fluorosis examination, along with water fluoride and urinary fluoride testing. Additionally, data from areas where the drinking water fluorosis control target was achieved for more than 12 years (10 villages, 50 people per village) were included as controls. A restricted cubic spline model was used to analyze the relationship between urinary fluoride levels and dental fluorosis prevalence, and benchmark dose (BMD) and benchmark dose lower bound (BMDL), as well as reference dose (RfD), were calculated using the benchmark dose method. Results: The prevalence rates of dental fluorosis among children in drinking water borne endemic fluorosis areas and areas of normal fluoride content in water in Tianjin were 10.58%, 7.60%, with a geometric mean urinary fluoride level of 0.72 and 0.60 mg/L,respectively. There were statistically significant differences in both dental fluorosis prevalence and geometric mean urinary fluoride levels between the drinking water borne endemic fluorosis areas group and the areas of normal fluoride content in water ( χ 2/Z = 4.05 , -7.31, both P <0.05). Across different periods of water source improvement, there were statistically significant differences in overall population, male, and female dental fluorosis prevalence rates and geometric mean urinary fluoride levels ( χ 2/H =44.95, 23.96, 21.05; 168.39, 63.93, 107.50, all P <0.01). Significant differences were also observed across age groups among children from drinking water borne endemic fluorosis areas in terms of dental fluorosis prevalence and geometric mean urinary fluoride levels ( χ 2/H =32.14, 79.73, both P <0.01). The results of the restricted cubic spline model showed that the risk of dental fluorosis in different sex, age and overall children in the drinking water borne endemic fluorosis areas increased significantly with rising urinary fluoride concentration(all P-general trend <0.05). The BMD value for the drinking water borne endemic fluorosis areas was 1.72 mg/L, the BMDL was 1.31 mg/L, and the RfD was 1.31 mg/L. Conclusions The prevalence of dental fluorosis among children in the drinking water borne endemic fluorosis areas in Tianjin has been effectively controlled, but it is still higher than that in the areas of normal fluoride content in water. Moreover, urinary fluoride levels and dental fluorosis prevalence among children from drinking water borne endemic fluorosis areas show a clear dose response relationship.

Objective To investigate the prevalence and influencing factors of thyroid enlargement in school-age children in Tianjin. Methods School-age children were randomly selected in Tianjin to undergo thyroid ultrasound examination, and salt iodine, urine iodine, height, and weight tests. A questionnaire survey was conducted. Univariate and multivariate regression models were used to analyze the risk factors for thyroid enlargement. Results A total of 917 children aged 7-13 years in Tianjin were surveyed, with a thyroid enlargement rate of 4.03% and a median thyroid volume of 2.60 ml. There was a non-linear relationship between children's body mass index (BMI) and the incidence of thyroid enlargement in children (P=0.008), and a linear relationship between children's body surface area (BSA) and the incidence of thyroid enlargement in children (P<0.001). Being 9 years old (OR=3.728, 95%CI: 1.343-10.343, P=0.012), obesity (OR=3.886, 95%CI: 1.801-8.384, P=0.001), having lunch at school (OR=3.157, 95%CI: 1.497-6.658, P=0.003) and frequent consumption of preserved foods (OR=4.611, 95%CI: 1.643-12.945, P=0.004) were risk factors for goiter in children. Regular consumption of seaweed (OR=0.305, 95%CI: 0.100-0.927, P=0.036) was a protective factor for goiter in children. Conclusion The incidence of thyroid enlargement in children in Tianjin meets national standards. Obesity, eating lunch at school, frequently consuming pickled foods, and being 9 years old may be risk factors for thyroid enlargement in children. Eating seaweed or kelp regularly is a protective factor. At the same time, attention should be paid to the relationship between BMI, BSA, and thyroid enlargement rate in children..

Objective To explore the association between different levels of fluoride exposure and dyslipidemia in elderly people, and to analyze the influencing factors and their interactions. Methods A total of 1 143 elderly people over 60 years old were randomly selected from historical high water fluorosis areas and control areas in Tianjin. Logistic regression model and classification tree model were used to analyze the influencing factors of dyslipidemia, and to analyze the interaction between high fluoride exposure and relevant influencing factors on dyslipidemia. Results The prevalence of elevated low density lipoprotein cholesterol (LDL-C) was 5.69% (65/1 143). There was a significant difference in the prevalence of high LDL-C in different fluoride-exposed areas (2 = 0.092，P = 0.762). Multivariate logistic analysis showed that high fluoride exposure (OR=2.306，95%CI：1.185-4.491) and abdominal obesity (OR=2.274，95%CI：1.299-3.978) were risk factors for high LDL-C, while type B personality (OR=0.529，95%CI：0.308-0.908) was a protective factor for high LDL-C. The results of classification tree model showed that abdominal obesity contributed the most to the prevalence of high LDL-C in the elderly, followed by high fluoride exposure and hyperglycemia. There was a significant multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia (OR=5.191,95%CI：1.609-16.745，P=0.006). Conclusion High fluoride exposure may increase the risk of high LDL-C, and there is a multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia.

ObjectiveTo explore the mechanism by which Buyang Huanwutang regulates the glutathione peroxidase 4 （GPX4）-acyl-CoA synthetase long-chain family member 4 （ACSL4） axis to inhibit ferroptosis and promote neurological functional recovery after spinal cord injury （SCI）. MethodsNinety rats were randomly divided into five groups： sham operation group， model group， low-dose Buyang Huanwutang group （12.5 g·kg^-1）， high-dose Buyang Huanwutang group （25 g·kg^-1）， and Buyang Huanwutang + inhibitor group （25 g·kg^-1 + 5 g·kg^-1 RSL3）. The SCI model was established by using the allen method. Tissue was collected on the 7th and 28th days after operation. Motor function was assessed by using the Basso-Beattie-Bresnahan （BBB） scale. Hematoxylin-eosin （HE）， Nissl， and Luxol fast blue （LFB） staining were performed to observe spinal cord histopathology. Transmission electron microscopy was used to examine mitochondrial ultrastructure. Immunofluorescence staining was used to detect the number of NeuN-positive cells and the fluorescence intensity of myelin basic protein （MBP）， GPX4， and ACSL4. Real-time fluorescent quantitative polymerase chain reaction （Real-time PCR） was used to analyze the mRNA expression of GPX4 and ACSL4. Enzyme linked immunosorbent assay （ELISA） was performed to measure the levels of reactive oxygen species （ROS）， malondialdehyde （MDA）， glutathione （GSH）， and superoxide dismutase （SOD）. Colorimetric assays were used to determine the iron content in spinal cord tissue. ResultsCompared to the sham operation group， the model group exhibited significantly reduced BBB scores （P<0.01）， severe pathological damage in spinal cord tissue， and marked mitochondrial ultrastructural disruption. In addition， the model group showed a decrease in the number of NeuN-positive cells （P<0.01）， reduced fluorescence intensity of MBP and GPX4 （P<0.01）， lower levels of GSH and SOD （P<0.01）， and downregulated mRNA expression of GPX4 （P<0.01）. Moreover， compared to the sham operation group， the model group had elevated levels of ROS， MDA， and tissue iron content （P<0.01）， along with increased fluorescence intensity and mRNA expression of ACSL4 （P<0.01）. Compared with the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group showed significantly improved BBB scores （P<0.05， P<0.01） and exhibited less severe spinal cord tissue damage， reduced edema and inflammatory cell infiltration， increased neuronal survival， and more intact myelin structures. Additionally， mitochondrial ultrastructure was significantly improved in the Buyang Huanwutang group. Compared to the model group and Buyang Huanwutang + inhibitor group， the Buyang Huanwutang group significantly increased the number of NeuN-positive cells and the fluorescence intensity of MBP （P<0.05， P<0.01）. Furthermore， Buyang Huanwutang significantly increased the fluorescence intensity and mRNA expression of GPX4 （P<0.01） and decreased the fluorescence intensity and mRNA expression of ACSL4 （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. Finally， the Buyang Huanwutang group significantly decreased ROS， MDA， and tissue iron content （P<0.01） and significantly increased GSH and SOD levels （P<0.01） compared to the model group and Buyang Huanwutang + inhibitor group. ConclusionBuyang Huanwutang inhibits ferroptosis through the GPX4/ACSL4 axis， reduces secondary neuronal and myelin injury and oxidative stress， and ultimately promotes the recovery of neurological function.

Background and purpose:Intrathecal chemotherapy is one of the mainstay treatment options for leptomeningeal metastases(LM)from solid tumors.A previous phase Ⅰ study demonstrated the safety and potential efficacy of intrathecal anti-programmed death receptor 1(anti-PD-1)for LM from melanoma.The synergistic efficacy of systemic chemotherapy combined with anti-PD-1 has been widely known.This study aimed to evaluate the safety and feasibility of intrathecal chemotherapy(pemetrexed)and anti-PD-1(toripalimab)for LM patients from solid tumors.Methods:The subjects were patients with LM from solid tumors who were treated at Affiliated Huizhou Hospital of Guangzhou Medical University/Third People's Hospital of Huizhou City.A 3+3 dose de-escalation strategy was implemented to determine the recommended dose with an initial dose of PD-1 inhibitor(toripalimab)40 mg and pemetrexed 15 mg.Pemetrexed was administered twice weekly for the initial 2 weeks of induction therapy,once weekly for the subsequent 4 weeks of consolidation therapy,and once monthly during maintenance therapy.PD-1 inhibitor was initiated at the 4th administration of pemetrexed,administered every 2 weeks for 6 weeks;subsequently,responders continued monthly maintenance therapy alongside pemetrexed.The primary objective was to assess safety based on adverse events and the recommended dose.All participants were observed to investigate the clinical response rate(CRR),disease control rate(DCR)and overall survival(OS).This study was approved by the ethics committee of Affiliated Huizhou Hospital of Guangzhou Medical University/Third People's Hospital of Huizhou City(ethics number:2024-KY-029-01).Results:Seven patients(male:3,female:4,median age:57 years)were enrolled between June and September 2024,including non-small cell lung cancer(6)and breast cancer(1).All patients presented with positive cerebrospinal fluid(CSF)cytology.Six patients presented LM-related neurological dysfunction.Five patients showed LM-related neuroimaging findings.Six patients completed the induction and consolidation therapy,and subsequently received maintenance therapy.One patient,due to bacterial meningitis,did not complete the final administration of toripalimab during consolidation therapy,and maintenance therapy was administered after infection control.Adverse events rate was 100%(7/7),including myelosuppression(100.00%,n=7),elevation of hepatic aminotransferases(42.86%,n=3),fatigue(28.57%,n=2)and hypothyroidism(14.29%,n=1).Three(42.86%)patients had grade 3 adverse events(myelosuppression).The immune-related adverse event(irAE)rate was 14.29%,manifested as hypothyroidism(Grade 2).No dose-limiting toxicity(DLT)was observed.Thus,no de-escalation was applied.The recommended dose was determined to be PD-1 inhibitor 40 mg in combination with pemetrexed 15 mg.Three patients showed improved neurological dysfunction,1 with CSF cytological response,and 2 with neuroimaging improvement.CRR was 57.14%(4/7)by response assessment in neuro-oncology(RANO)proposal criteria.DCR was 100%(7/7).Three patients exhibited abscopal effects with regression of brain metastasis lesions,primary lung lesion and mediastinal lymph nodes,respectively.As of April 10,2025,1 patient died.The median follow-up time was 7.7(5.9-9.3)months.The median OS was not reached with a 6-month OS rate of 85.71%.Conclusion:The combination therapy of intrathecal pemetrexed and a PD-1 inhibitor was well-tolerated and feasible,while also exhibiting potential clinical efficacy in treating LM from solid tumors including non-small cell lung cancer.

Objective To investigate the value of MRI of the sternal end of clavicle in bone age assessment in Chinese population,especially its applicability in the determination of criminal responsible age.Methods A total of 431 patients aged from 10.00 to 29.99 years with neck or chest MRI were retrospectively collected.According to the Schmeling grading method,the epiphyseal development of the clavicle MRI was divided into five grades.The consistency of methods was evaluated.The correlation and general descriptive analysis between MRI grades and age was analyzed.The sex difference was analyzed.Curve fitting was used to establish a nonlinear model between age and grades.Results The grades of clavicle MRI showed a significant age-related trend(Figure 2),and the correlation was 0.861(0.887 in males and 0.840 in females).Except for grade 1,there was no significant difference between males and females in other grades.The minimum age of male grade 3 was greater than 14 years old,and the minimum age of female grade 3 was greater than 16 years old.The minimum age in grade 4 and grade 5 was over 18 years old in both sexes.The best curve fitting model was cubic model for both sexes(R2=0.805 for men and 0.722 for women).Conclusion Clavicle MRI can be used for the assessment of bone age in Chinese population.Complete epiphyseal plate closure can be used as a reliable indicator for the determination of age at 18 years old,and it is expected to achieve radiation-free forensic bone age assessment.

Objective:To learn about the current status of fluoride in drinking water from historical drinking water-borne endemic fluorosis areas in Tianjin, and to evaluate the non-carcinogenic health risk of fluoride in drinking water for children.Methods:A cross-sectional survey was conducted from January to November 2023 to investigate the fluoride level in drinking water in 2 028 villages with children aged 6 - < 18 years residing in 10 historical drinking water-borne endemic fluorosis areas in Tianjin. Based on the risk assessment model of the Technical Guide for Environmental Health Risk Assessment of Chemical Exposure (WS/T 777-2021) and the child specific exposure parameters in the highlights of the Chinese exposure factors handbook (Children volume), the hazard index (HI) was used to quantify and assess the non-carcinogenic health risk of fluoride in drinking water for children of different age groups (6 - < 9, 9 - < 12, 12 - < 15, 15 - < 18 years old).Results:The water fluoride level [ M ( Q1, Q3)] in the historical drinking water-borne endemic fluorosis areas in Tianjin was 0.28 (0.12, 0.85) mg/L, ranging from 0.05 to 1.08 mg/L. The HI values of children in each age group were 0.218, 0.185, 0.136, and 0.124, respectively, all < 1, indicating low non-carcinogenic health risk. Among them, the age group of 6 - < 9 years old had the highest HI value, with HI values ranging from 0.148 to 0.412 in 10 regions, and the difference was statistically significant ( H = 594.62, P < 0.001). Comparing drinking water of different source types, regions, and treatment methods, there were statistically significant differences in HI values among children of different age groups ( Z = - 9.25, - 9.25, - 9.25, - 9.25, - 6.96, - 6.96, - 6.96, - 6.96, H = 146.75, 146.75, 146.75, 146.75, P < 0.001). Conclusion:The non-carcinogenic health risks of fluoride in drinking water for children in historical drinking water-borne endemic fluorosis areas of Tianjin are relatively low, but there is still a need to strengthen monitoring and early warning for young children.

Objective:To learn about the iodine nutrition status of pregnant women in Tianjin and analyze the influencing factors of moderate to severe iodine deficiency in pregnant women.Methods:From January 2022 to December 2024, a stratified random sampling method was adopted. Each year, five sampling areas were divided into the east, west, south, north and central directions in 16 districts of Tianjin. Ten pregnant women from one township/street in each area were selected for questionnaire surveys. Household salt samples and random urine samples were collected to measure salt iodine and urinary iodine levels. Multivariate logistic regression was used to analyze the influencing factors of moderate to severe iodine deficiency in pregnant women, and a restricted cubic spline model was used to analyze the dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women and salt iodine level.Results:A total of 2 532 pregnant women in Tianjin were surveyed, with an age of (30.70 ± 4.44) years. Among them, 53.20% (1 347/2 532) had received health education, and 52.45% (1 328/2 532) actively supplemented iodine. A total of 2 532 household salt samples of pregnant women were tested, with a median salt iodine level of 23.66 mg/kg. The coverage rate of iodized salt was 74.45% (1 885/2 532), the qualified rate of iodized salt was 87.59% (1 651/1 885), and the consumption rate of qualified iodized salt was 65.21% (1 651/2 532). A total of 2 532 urine samples of pregnant women were tested, with a median urinary iodine level of 151.68 μg/L. Among them, 652, 1 348 and 532 urine samples were collected from pregnant women in the early, middle, and late stages of pregnancy, respectively, with median urinary iodine levels of 150.80, 153.00 and 143.68 μg/L, respectively. Multivariate logistic regression analysis showed that consuming iodized salt was a protective factor for the moderate to severe iodine deficiency in pregnant women ( OR = 0.70, 95% CI: 0.58 - 0.86, P < 0.001). Restricted cubic spline analysis showed that there was a linear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women and salt iodine level ( Poverall < 0.001, Pnonlinear = 0.065). Further stratified analysis revealed that there was a linear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women who had received iodine supplementation and salt iodine level ( Poverall = 0.018, Pnonlinear = 0.554), while there was a nonlinear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women who had not received iodine supplementation and salt iodine level ( Poverall < 0.001, Pnonlinear = 0.029). Conclusions:From 2022 to 2024, the overall iodine level of pregnant women in Tianjin is appropriate, but some pregnant women are at risk of iodine deficiency. Consuming iodized salt is a protective factor against the moderate to severe iodine deficiency in pregnant women. It is still necessary to further implement comprehensive prevention and control measures mainly based on iodized salt.

Objective To compare the dosimetric disparities among static intensity-modulated radiotherapy(IMRT),volumetric modulated arc therapy(VMAT),and tomotherapy(TOMO)techniques in cervical cancer radiotherapy for providing data support for clinical decision-making scheme of radiotherapy.Methods The clinical data of 19 cervical cancer patients,treated at the Affiliated Cancer Hospital and Institute of Guangzhou Medical University from February to May in 2024,were analyzed.Three plans were devised for each case using IMRT,VMAT,and TOMO techniques,followed by dosimetric evaluation in terms of various metrics such as dose volume parameters of the target areas as well as organs-at-risk(OAR),conformity index(CI),homogeneity index(HI),and delivery time.Results All 3 plans met the clinical prescription requirements for the target areas.Compared with static IMRT and VMAT,TOMO had significantly lower Dmean and Dmaxof PCTV and PGTVnd.For OAR,TOMO demonstrated significant advantages over IMRT and VMAT in the Dmean of the bladder,the Dmean,Dmax,V30,V40of the rectum,the Dmean,Dmax,V20,V30of left and right femoral heads,and the Dmean,V20,V50of the pelvis(P<0.05).In addition,the TOMO group showed significantly higher CI for both PCTV and PGTVnd as compared with IMRT and VMAT groups,and lower PGTVnd HI than IMRT group(all P<0.05).Although there was trivial difference among 3 groups in term of PCTV HI,TOMO group performed slightly better than the other two groups.Notably,VMAT technique had the shortest treatment time.Conclusion In various treatment modalities for cervical cancer,TOMO is superior to IMRT and VMAT in terms of target dose coverage,OAR dose distribution,CI,and HI.However,VMAT has the highest efficiency.