Polyethylene (PE) is widely used due to its excellent properties. However, the improper disposal of PE waste has led to serious environmental pollution. Microbial degradation of PE is a low-carbon, environmentally friendly, and highly efficient method of homogeneous recycling. The use of microbial degradation technology to treat polyethylene waste has become one of the current research hotspots. As a result, employing microbial degradation technology to address polyethylene waste has become a key focus of current research. A PE-degrading strain ETX1 was screened from waste plastics in a landfill by the enrichment culture method. The strain was identified as Lysinibacillus sp.. After incubating PE powder with the strain for 20 days, a weight loss of 29.41% was observed. Fourier transform infrared spectroscopy (FTIR) showed that special absorption peaks such as carbonyl and hydroxyl groups appeared, proving that ETX1 had the effect of degrading PE. The degradation effect of this strain was characterized by the weight loss of PE film, FTIR, scanning electron microscopy, and contact angle. The results showed that ETX1 reduced the PE film weight by up to 5.23% within 120 days. The film structure was damaged, with holes formed by erosion on the film surface, and the hydrophilicity was enhanced. Additionally, a stronger carbonyl absorption peak appeared. The discovery of the PE-degrading strain ETX1 not only enriches the resources of PE plastic-degrading strains but also lays a foundation for mining efficient PE-degrading elements, obtaining degrading enzymes, and deciphering related degradation pathways.
Polyethylene/chemistry* ; Biodegradation, Environmental ; Spectroscopy, Fourier Transform Infrared ; Bacillaceae/classification* ; Plastics/metabolism*

Objective:To explore the effects of canagliflozin on cardiac function and its regulation of ferroptosis in rats with heart failure with preserved ejection fraction (HFpEF).Methods:Thirty-two 7-week-old Dahl salt-sensitive rats were selected and randomly divided into four groups: the control group (fed with low-salt diet), the HFpEF group (fed with high-salt diet), the canagliflozin 20 group (fed with high-salt diet and 20 mg·kg -1·d -1 canagliflozin), and the canagliflozin 30 group (fed with high-salt diet and 30 mg·kg -1·day -1 canagliflozin). Body weight and blood pressure of the rats in each group were monitored. Metabolic cage tests were conducted at the10 th week of the experiment, and echocardiography was performed at the 12 th week, after which the rats were killed. Blood and left ventricular samples were collected. HE staining, Masson staining, Prussian blue iron staining, and reactive oxygen species staining were performed to observe the cardiomyocyte size and shape, degree of interstitial fibrosis, iron staining, reactive oxygen species production under optical microscope. The ultrastructure of cardiomyocytes was observed under electron microscope. Western blotting and real-time fluorescent quantitative reverse transcription polymerase chain reaction (RT-qPCR) were used to detect the expression levels of proteins and mRNA related to ferroptosis in left ventricular myocardial tissue of rats in each group. Results:After 1 week of adaptive feeding, all rats survived. Metabolic cage results showed that compared with control group, rats in the HFpEF group, canagliflozin 20 group and canagliflozin 30 group had more food intake, water intake and urine output, and lower body weight (all P<0.05). These changes were more pronounced in canagliflozin 20 group and canagliflozin 30 group than in HFPEF group, and only the body weight at the 12 th week showed a statistically significant difference between canagliflozin 20 group and canagliflozin 30 group ( P<0.05). The blood pressure of 6 th week and 12 th week, heart weight and left ventricular corrected mass of 12 th week of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while the ratio of early mitral valve peak velocity to late mitral valve peak velocity of 12 th week was lower (all P<0.05). HE and Masson staining showed that compared to control group, the myocardial fibers in the left ventricular myocardial tissue of rats in HFpEF group were disordered, with larger cell diameter ((0.032±0.004) mm vs. (0.023±0.003) mm, P<0.05), irregular shape, obvious proliferation of interstitial collagen fibers, and higher collagen volume fraction (0.168±0.028 vs. 0.118±0.013, P<0.05). Compared with HFpEF group, rats in the canagliflozin 20 group and canagliflozin 30 had more orderly arranged myocardial fibers, more regular cardiomyocyte shape, smaller cell diameter, and lower collagen volume fraction ( P<0.05). It was observed under electron microscopy that, compared to control group, most of the striated muscles in myocardial tissue of HFpEF group were broken, and the Z line and M line could not be clearly distinguished, some changes such as mitochondrial swelling, membrane thickening, cristae reduction or even disappearance occurred. In the canagliflozin 20 group and canagliflozin 30 group, the arrangement of striated muscles in the myocardial tissue of rats tended to be more regular, and the morphological changes of mitochondria were milder. Prussian blue iron staining results showed that the iron content in myocardial tissue of rats in HFpEF group was higher than that in control group, canagliflozin 20 group and canagliflozin 30 group. Reactive oxygen species staining results showed that the reactive oxygen species content in the myocardial tissue of rats in HFpEF group was higher than that of control group, canagliflozin 20 group and canagliflozin 30 group. Biochemical analysis of myocardial tissue showed that Fe 2+ and malondialdehyde content in myocardial tissue of rats in HFpEF group were higher than those in control group, canagliflozin 20 group and canagliflozin 30 group, while glutathione content was lower (all P<0.05). Western blot and RT-qPCR detection results showed that compared to control group, rats in HFpEF group had higher expression levels of transferrin receptor 1 (protein relative expression level: 1.37±0.16 vs. 0.31±0.12), acyl-CoA synthetase long-chain family member 4 (protein relative expression level: 1.31±0.15 vs. 0.63±0.09) protein and mRNA, and lower expression levels of ferritin heavy chain 1 (protein relative expression level: 0.45±0.08 vs. 1.41±0.15) protein and mRNA (all P<0.05). There was no statistically significant difference in these indicators between canagliflozin 20 group and the canagliflozin 30 group (all P>0.05). There was no significant difference in levels of glutathione peroxidase 4 protein and mRNA expression in myocardial tissue of rats in four groups( P>0.05). Conclusion:Canagliflozin improves cardiac function in HFpEF rats by regulating the ferroptosis mechanism.

Objective:To delineate the surgical methodology and therapeutic paradigm of proximal tibial notch retrograde interlocking intramedullary nailing for ameliorating deformities due to osteofibrous dysplasia (OFD) in a pediatric population.Methods:A retrospective assessment was conducted on the medical records of individuals undergoing orthopedic osteotomy complemented by retrograde interlocking intramedullary nailing for OFD of the tibia from January 2016 to December 2019. The cohort comprised 15 patients, with a follow-up exceeding three years, documenting complete data sets. The patient profile included 8 males and 7 females, with 8 left-side and 7 right-side afflictions. The mean age at the time of surgery was 10.1±2.5 years, ranging from 7.1 to 12.6 years. Parameters measured were preoperative and postoperative imaging findings, which encompassed the scope of the lesion (longitudinal lesion length relative to tibial length), coronal and sagittal limb alignments, and lower limb length discrepancies.Results:The mean follow-up duration was 3.4±1.3 years, ranging from 3 to 6.6 years. Preoperatively, prominent anterior tibial arch deformities and limping were present, with 7 cases reporting fatigue-induced pain and 3 instances of pathological fractures. Post-surgery, pain symptoms were resolved, gait disturbances were improved in 9 patients, and completely resolved in 6. Tibial osteotomy or fracture healing of 15 patients averaged 3.9±0.7 months (range 3-5 months). The lesion range before surgery was 0.41±0.17, immediately after surgery was 0.38±0.17, and at the last follow-up was 0.30±0.16, with no statistical significance ( F=0.101, P=0.904). Lesion range showed no significant change throughout treatment, but radiographic density within the lesion notably increased post-surgery, suggesting bone improvement. The anterior tibial arch Angle was 28.30°±6.62° (range 20°-45°) before surgery, 4.73°±1.53° immediately after surgery, and 6.87°±1.36° at the last follow-up, with statistical significance ( F=159.739, P<0.001). A significant correction in the anterior tibial arch deformity was achieved and maintained postoperatively. There was no significant angular deformity of the tibia in the coronal plane before operation, and the medial proximal tibial angle (MPTA) and lateral distal tibial angle (LDTA) were 87.50°±1.46° and 88.30°±1.62°, 88.40°±1.46° and 88.70°±1.45° immediately after surgery, and 88.00°±1.39° and 89.10°±1.53° at the last follow-up, the differences were statistically significant ( F=1.741, P=0.188; F=1.016, P=0.371), there was no coronal deformity of tibia. The limb length discrepancy (LLD) was 0.60±0.98 cm before surgery, 0.18±0.93 cm at the last follow-up, with statistical significance ( t=0.096, P=0.761). There were no incidents of postoperative complications such as infection. Conclusion:In pediatric cases of tibial deformities attributed to osteofibrous dysplasia, a therapeutic strategy involving osteotomy for lower limb realignment, sans curettage or bone grafting of the lesion, followed by retrograde interlocking intramedullary nailing, yields favorable outcomes. Importantly, this implantation technique does not compromise the integrity of the proximal tibial epiphyseal plate in children and adolescents.

Objective:To explore the clinical effect of plating after lengthening to assist the consolidation of tibial shortening deformity in children.Methods:A retrospective analysis was conducted on 10 children with tibial shortening who were treated with circular external fixator lengthening and replacement with plate-assisted internal fixation (study group) in the Department of Pediatric Orthopedics of Tianjin Hospital from November 2019 to October 2022, and 16 children who were treated by circular external fixator only during the same period were enrolled as the external fixator group (control group). Among the 26 cases, there were 15 males and 11 females, 10 left knees and 16 right knees. The average age at the time of surgery was 8.8±4.7 years (range 5.1-13.8 years). The gender, side, age at the time of surgery were compared between the two groups. The extension length, external fixator index, healing index, Kolcaba comfort scale score, knee and ankle joint range of motion, complications and average total hospitalization costs were recorded.Results:There were no significant differences in gender, side, age at the time of surgery between the study group and control group. The extended lengths were 5.44±1.25 cm and 5.78±1.11 cm respectively without significant difference ( t=0.096, P=0.096). The external fixator index and healing index were 17.86±2.94 d/cm vs. 50.97±7.03 d/cm and 40.94±6.63 d/cm vs. 45.24±5.98 d/cm in study group and the control group with significant differences ( t=13.299, P<0.001; t=1.289, P=0.033). The Kolcaba comfort scale score of the children in the study group was higher than that of the control group, with significant difference ( t=6.821, P=0.001). Comparing the range of motion of the knee and ankle joints between the two groups, there were no significant differences before surgery, at the end of extension surgery, and at the final follow-up. When the extension end was healed, the range of motion of the knee joint was137.89°±4.40° vs. 114.09°±13.60° and ankle joint was 64.35°±5.50° vs. 56.65°±8.86° in the study group and control group with significant difference ( t=17.235, P<0.001; t=7.821, P=0.002). In the study group, 4 cases had pin tract infection, but no refracture occurred; in the control group, pin tract infection occurred in 13 cases, and refracture occurred in 2 cases after removal of the external fixator. The average total hospitalization cost of the study group was higher than that of the control group with significant difference ( t=3.745, P=0.036). Conclusion:The clinical effect of replacing plate-assisted internal fixator during the mineralization period of tibial shortening in children is reliable, and can significantly shorten the time for using external fixator. It is beneficial to the healing of the extended end of the osteotomy and the functional recovery of the knee and ankle joints. Being more comfortable for children with fewer complications, it is applicable for children who need long-distance extension, multiple extensions with limited joint function, poor tolerance for external fixators and low treatment compliance.

Objective:To investigate the necessity of internal fixation of the fibular fracture in the treatment of degree Ⅱ ankle supination-external rotation injury by the Dias-Tachdjian classification in children.Methods:A retrospective study was conducted to analyze the data of 69 children with ankle fracture (degree Ⅱ ankle supination-external rotation injury by the Dias-Tachdjian classification) who had been treated at Department of Orthopedic Trauma, The People's Hospital of Weifang and Department of Pediatric Orthopedics, Tianjin Hospital from January 2015 to October 2021. There were 41 males and 28 females with an age of (10.1±1.4) years, and 37 left and 32 right sides affected. The patients were divided into 2 groups according to whether internal fixation of the fibular fracture was performed. Group A consisted of 21 cases with fibular internal fixation and group B of 48 cases without fibular internal fixation. The preoperative data, operation time and operation expenses were recorded and compared between the 2 groups. At the last follow-up, the anteroposterior and lateral radiographs of bilateral full length lower limbs and ankle joints were taken; the lateral distal tibial angle (LDTA) and the anterior distal tibial angle (ADTA) on the affected side, and the disparity between bilateral ankle tibiotalar angles were measured; ankle function was assessed according to the ankle-hindfoot score of American Association of Foot and Ankle Surgery (AOFAS); the occurrence of premature physeal closure (PPC) was recorded.Results:There was no significant difference in the preoperative general data between the 2 groups, indicating comparability ( P>0.05). All patients were followed up for (19.5±4.1) months. At the last follow-up, the LDTA on the affected side was 89.6° (87.9°, 90.5°) in group A and 88.6°±1.9° in group B; the ADTA on the affected side was 80.9° (79.0°, 81.4°) in group A and 80.0° (78.6°, 81.2°) in group B; the disparity between bilateral ankle tibiotalar angles was 1.1°±0.5° in group A and 1.2°±0.5° in group B; the AOFAS ankle-hindfoot score was (89.5±5.2) points in group A and 89.0 (87.0, 92.0) points in group B. There was no statistically significant difference between the 2 groups in the above items ( P>0.05). The incidence of PPC was, respectively, 14.3% (3/21) and 14.6% (7/48) in groups A and B, showing no statistically significant difference ( P>0.05). Conclusions:In the treatment of degree Ⅱ ankle supination-external rotation injury in children, internal fixation of the fibular fracture has no significant effect on the imaging angles or the function of the ankle joint. After anatomic reduction of the distal tibia, the fibular fracture can be treated without internal fixation to reduce operational trauma, shorten operation time and reduce operation expenses.

Objective:To study the efficacy of closed reduction with a self-developed T-frame plus robotic navigation in the treatment of supracondylar humeral fractures of Gartland type Ⅲ in children.Methods:A retrospective study was conducted to analyze the data of 67 children with supracondylar fracture of Gartland type Ⅲ who had undergone surgery at The Fifth Hospital of Harbin from January 2023 to March 2024. There were 35 males and 32 females with an age of (5.6±1.2) years. The children were divided into 2 groups according to different surgical methods. The control group (33 cases) was treated by closed reduction and internal fixation with percutaneous K-wire and the study group (34 cases) by closed reduction with a self-developed T-frame plus robotic navigation for internal fixation with percutaneous K-wire. The operation time, anatomical reduction, intraoperative fluoroscopy frequency, intraoperative needle adjustment, Flynn score at the last follow-up and complications were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, indicating comparability ( P>0.05). All children were followed up for (6.3±2.5) months after surgery. There were no significant differences in operation time, Flynn score at the last follow-up or incidence of complications between the study and the control groups ( P>0.05). The rate of anatomical reduction in the study group (97.1%, 33/34) was significantly higher than that in the control group (54.5%, 18/33), and the intraoperative fluoroscopy frequency [(11.6±2.5) times] and needle adjustment (5.6±1.2) times in the study group were significantly lower than those in the control group [(37.2±2.1) times and (28.7±3.9) times] ( P<0.05). Conclusions:In the treatment of supracondylar humeral fractures of Gartland type Ⅲ in children, our self-developed T-frame can play a good role in fracture reduction and temporary fixation, avoiding iatrogenic secondary injuries caused by freguent reduction and adjustment of needle threading in the course of robotic navigation.

Objective:To establish Chinese grading standards for elderly disability and dementia, in accordance with the International Classification of Functioning, Disability and Health(ICF)items, and to develop visual assessment tools that can be easily understood by patients, family members, and health workers.The aim is to verify the reliability and validity of these tools.Methods:In this study, we established five categories of elderly disability classification, along with corresponding ICF items and visual evaluation tools.The appropriateness and compatibility of the tools were assessed using questionnaires, which included illustrations, GIF dynamic pictures, and ICF items.Correlation analysis was conducted to screen the items, and the validity of the visual evaluation tools was determined through a picture-text matching validity test.Reliability was evaluated using internal consistency or test-retest reliability, and validity was assessed through content validity.Results:Each grade of disability was initially divided into five levels.However, after expert consultations and classification revision, each level was ultimately simplified into four levels with clearer descriptions.The Pearson correlation coefficients between all items and the total scores of each part were found to exceed 0.3, and the difference was statistically significant(all P<0.05).The average and mode of the illustrations and GIF dynamic pictures, when matched with related descriptions, were both above 3, with consistency rates surpassing 50%.Statistical differences were observed in eight items between the two visual assessment tools.The Cronbach's α coefficients, which reflect internal consistency, were all above 0.60.The intra-group correlation coefficients, which indicate test-retest reliability, were all greater than 0.70.The content validity index of the questionnaire at the overall level was above 0.90, while the item-level content validity index was more than 0.78. Conclusions:The Chinese grading standards for elderly disability and dementia, which are aligned with the ICF, have been preliminarily established.Visual assessment tools have also been developed, which demonstrate good reliability and validity.Among the two visual assessment tools, GIF dynamic pictures were found to be more popular and easier to understand.

Objective:To explore the mediating effect of carotid atherosclerosis on serum triglyceride-glucose (TyG) index and silent lacunar infarction (SLI) in non-diabetic population.Methods:A total of 2 482 patients were selected from the Health Examination Center of Hebei General Hospital from January 2019 to December 2021. The basic demographic information, biochemical parameters, calculated TyG index and carotid plaque score were collected. SLI was diagnosed according to the criteria formulated by Chinese Society of Neurology. Participants were divided into SLI group and non-SLI group according to whether there was SLI in brain magnetic resonance imaging, and the non-SLI group was normal without lacunar infarction. Spearman correlation analysis was used to explore the correlation between TyG index and carotid plaque score. Binary Logistic regression analysis was used to analyze the effects of TyG index and carotid plaque score on SLI. Bootstrap was used to explore whether carotid plaque score mediated the association between TyG index and SLI.Results:There were 471 patients (18.98%) who had SLI, and 2 011 patients (81.02%) did not. Carotid plaque score [2(0, 5) vs 1(0, 3)] and TyG index [7.17(6.81, 7.64) vs 7.12(6.77, 7.54)] were increased in the SLI group compared with the non-SLI group ( Z=-4.213, Z=-2.636, P<0.05). Spearman correlation analysis showed that carotid plaque score was positively correlated with TyG index ( r=0.083, P<0.001). Multivariate Logistic regression analysis indicated that carotid plaque score ( OR=1.047, 95% CI 1.002-1.094) and TyG index ( OR=1.329, 95% CI 1.106-1.598) were independent risk factors for SLI ( P<0.05). Mediated effect analysis showed that TyG index had a direct effect on the incidence of SLI (β=0.265, 95% CI 0.102-0.428). Carotid plaque score partially mediated the effect of TyG index on the incidence of SLI (β=0.024, 95% CI 0.009-0.043), and the mediating effect accounted for 8.30% of the total effects. Conclusion:In non-diabetic population, TyG index and carotid plaque score are predictors of SLI, and the carotid plaque score is a partial mediator in the effect of TyG index on the incidence of SLI.

Objective:To improve the prognosis stratification, especially early mortality(EM), of elderly patients with newly diagnosed multiple myeloma(NDMM).Methods:In this retrospective study, univariate and multivariate Cox regression analysis were conducted to identify the independent prognostic factors associated with overall survival(OS)and the chi-square test and multivariate Logistic analysis were used to identify the prognostic factors associated with EM in 223 elderly patients(age≥65 years)with NDMM from three centers in the country.Results:Increased NT-pro-BNP(≥300 pg/ml), ECOG-PS≥2 and stage Ⅲ R-ISS were identified as three independent adverse prognostic factors of OS.The rates of EM3, EM6, EM12 and EM24 were 12.1%, 20.1%, 32.2% and 60%, respectively.The most common cause for EM6(particularly EM3)was disease-related complications resulting from ineligibility for treatment due to poor physical performance, severe organ dysfunction or treatment discontinuation due to treatment intolerance, while the most common cause for EM12(particularly EM24)was disease progression or relapse mainly as a result of inadequate treatment.R-ISS staging failed to predict EM, while decreased eGFR, ECOG-PS≥2, and increased NT-pro-BNP were able to estimate the risk of EM, with increased NT-pro-BNP as a common independent factor for EM12( P=0.03)and EM24( P=0.015). Conclusions:R-ISS staging, which primarily reflects MM biology, cannot predict EM.However, factors such as NT-pro-BNP, eGFR and ECOG-PS associated with frailty and impairment of organ functions can be used to estimate the risk of EM, among which NT-pro-BNP may be the most important independent factor for EM.Therefore, incorporation of these frailty-related biomarkers into R-ISS staging may be able to more precisely estimate the prognosis and particularly early death of elderly patients with NDMM.

【Objective】 To explore the effect of inspection sheet on improving the quality of apheresis platelet, the satisfaction of blood donors and the cooperation ability of phlebotomists in the process of apheresis platelet collection. 【Methods】 Apheresis platelet donors from May to August 2021 in our center were selected as control group(without inspection sheet) and those from September to December 2021 were included in the observation group (with inspection sheet). The incidence of abnormal collection and the causes during collection process were compared between the two groups.And 100 first-time blood donors in each group were randomly selected for satisfaction survey. The questionnaire was made to investigate the phlebotomists’ recognition on the implementation of inspection sheet. 【Results】 The number of blood donors in the two groups were 6 673 and 6 559, with 111 and 49 abnormal cases, respectively. The total incidence of abnormal cases during blood collection before and after the implementation of inspection sheet was 1.66% and 0.75%, respectively, with the latter significantly lower than the former(P<0.001). The most common causes of abnormal conditions were repetitive puncture, followed by adverse reaction of blood donation, red blood cells contamination in platelet and fatty blood. The satisfaction of first-time blood donors was higher than before the implementation, and the recognition of phlebotomists on the inspection sheet was more than 90%. 【Conclusion】 The implementation of inspection sheet helps to regulate the collection process, strengthen the responsibility and service consciousness of phlebotomists, improve the satisfaction of blood donors, reduce the incidence of adverse events, and improve the quality of platelet products, which is worth popularizing in blood collection and supply institutions.