Background Occupational hazards in the workplace are often determined through on-site investigations and recognized hazards to determine monitoring items, and occupational health risk assessments are rarely carried out on the monitoring results. Objective Based on the qualitative results of volatile organic compounds, to monitor 8 types of volatile organic compounds in workplace air, and conduct occupational health risk assessments for workstations with disqualified results. Methods This study selected 29 enterprises from 12 key industries listed in the Work Plan for Monitoring Occupational Disease Hazards in Workplaces in Chongqing (2023) in 5 districts and counties of Chongqing. A total of 49 key workstations, including spray painting, glue brushing, glue adjustment, adhesion, printing, bonding, packing, oil film, feeding, material preparation,dispersion, and immersion, were selected for air sampling and chemical headspace treatment. The volatile organic compounds in the headspace were separated with a gas chromatography capillary column and sequentially entered into a mass spectrometer for detection. Qualitative analysis of each component was conducted using the National Institute of Technical Standards and Technology standard spectrum library and retention time. Based on the qualitative results, chemical hazards and related workstations were determined, then quantitative evaluation was conducted for key hazards in workplace air, and followed by occupational health risk assessment for the disqualified workstations using semi-quantitative exposure ratio. Results One or more of the 8 key chemical hazards were positive in the 29 enterprises, among which xylene (89.7%) and toluene (86.2%) had the highest positive rates, followed by benzene (34.5%), 1,2-dichloroethane (31.0%), ethylbenzene (20.7%), n-hexane (10.3%), and trichloromethane (6.9%), and trichloroethylene was negative. In the quantitative evaluation for occupational hazards in workplace air, the highest positive rates of chemical hazards were xylene (70.6%) and ethylbenzene (83.3%), and the highest disqualification rate of chemical hazards was 1,2-dichloroethane (50.0%). Out of the 29 enterprises, 8 reported disqualified air key chemical hazards, mainly in the workstations of spray painting and immersion. One spray painting workstation reported 3 disqualified chemical hazards, and one spary painting workstation reported 2 disqualified chemical hazards. The risk level of 1,2-dichloroethane in the spary painting workstations of 3 enterprises was high. The joint risk of 2 enterprises with multiple disqualified chemical hazards was high. Conclusion The positive rates of benzene derivatives and 1,2-dichloroethane in workplace chemicals are high in this study. The risk level of 1,2-dichloroethane in the spary painting workstations of 3 companies is high, and this substance needs special attention in future monitoring.

Objective:To evaluate the clinical effects of adjustable traction skin stretchers used in repair of wounds at the lower leg, foot and ankle.Methods:A retrospective study was performed to analyze the clinical data of 56 patients who had been treated for skin defects at the lower leg, foot and ankle from August 2016 to September 2022 at The First Affiliated Hospital of Zhengzhou University, Honghui Hospital, Affiliated to Xi'an Jiaotong University Medical College, The First Affiliated Hospital of Henan Polytechnic University, and Yunnan Zhongde Orthopedic Hospital. There were 35 males and 21 females, aged (39.9±18.7) years. There were 43 traumatic wounds, 3 burns, 6 inflammatory wounds, 3 relief incisions due to osteofascial compartment syndrome, and 1 scar. The areas of skin defect ranged from 2.5 cm × 2.0 cm to 20.0 cm × 10.0 cm. The duration of wounds was (8.6±7.8) d. All the wounds were repaired with adjustable traction skin stretchers. The row-hook type of skin stretchers was used in 28 cases, the single-rod type in 20 cases, the single-rod type combined with an external fixator in 5 cases, and a combination of the row-hook type and the single-rod type in 3 cases.The time for wound traction closure, color of wound skin margin, skin swelling around the wound, functional recovery of affected limb and complications were recorded.Results:The time from skin stretching to wound closure was (7.8±3.8) d in the 56 patients. The color of wound skin edge after stretching was normal in 16 cases, dark red in 38 cases, and dark in 2 cases; the skin swelling around the wound was degree 1 in 21 cases, degree 2 in 33 cases, and degree 3 in 2 cases. The 56 patients were followed up for (8.9±4.1) months. Primary wound closure was achieved in 48 patients, and secondary wound closure in 8 patients after repair with an autologous skin graft. Partial skin necrosis occurred due to tension blisters after skin stretching in 2 patients, one of whom was repaired with an autologous skin graft and the other of whom by dressing change. Deep bone infection recurred in 2 patients whose wounds healed after their bone defects were repaired using Ilizarov technique of bone transfer. In the 56 patients, the muscle strength of the lower extremity beyond the wound was recovered to normal, and the range of motion of the joints adjacent to the wound also recovered to normal.Conclusion:In repair of wounds at the lower leg, foot and ankle, adjustable traction skin stretchers can lead to fine clinical effects and limited complications, because the stretchers can control the tension of skin digitally and precisely.

Objective:To evaluate the efficacy of 3D printed patients-specific guide plates in assisting Ilizarov bone transport in the treatment of tibial bone defects.Methods:A retrospective study was conducted to analyze the clinical data of 24 patients with tibial bone defects who had been admitted to Institute of Trauma Orthopedics, The 80th Army Group Hospital of PLA from January 2018 to March 2022. There were 9 males and 15 females with an age of (49.8±6.5) years, and 4 upper tibial defects, 5 middle tibial defects, and 15 lower tibial defects. According to the methods of repairing bone defects, the patients were divided into 2 groups: a 3D printing group of 10 cases where a 3D printed patient-specific guide plate was used to assist Ilizarov bone transport in the treatment of tibial bone defects, and a traditional group of 14 cases where Ilizarov bone transport was performed in a traditional manner. The 2 groups were compared in terms of operation time, frequency of intraoperative fluoroscopy, axial angulation of the tibia at postoperation and the last follow-up, external fixation time (EFT) and external fixation index (EFI). At the last follow-up, healing of bone defects was evaluated according to the criteria of The Association for the Study and Application of the Method of Ilizarov (ASAMI), functional outcomes were evaluated according to the Paley criteria, and needle infection was recorded according to the Paley classification for complications.Results:There was no statistically significant difference in the preoperative general data between the 2 groups, indicating comparability ( P>0.05). All patients were followed up for (11.3±2.0) months on average after operation. The 3D printing group had significantly shorter operation time [(19.9±2.6) min] and significantly lower frequency of intraoperative fluoroscopy [(3.0±0.8) times] than the traditional group [(38.1±2.2) min and (8.9±1.3) times] (P<0.05), and had significantly better axial angulation of the tibia at postoperation and the last follow-up than the traditional group ( P<0.05). There was no significant difference in EFT or EFI between the 2 groups ( P>0.05), and the last follow-up revealed no significant difference either in bone healing, functional outcomes, or needle infection between the 2 groups ( P>0.05). Conclusion:In the treatment of tibial bone defects, compared with conventional Ilizarov bone transport, the Ilizarov bone transport assisted by a 3D printed patient-specific guide plate demonstrates advantages of shorter operation time, lower intraoperative fluoroscopy, and higher reduction accuracy.

Objective:To establish a mortality risk prediction model of severe bacterial infection in children and compare it with the pediatric early warning score (PEWS), pediatric critical illness score (PCIS) and pediatric risk of mortality score Ⅲ (PRISM Ⅲ).Methods:A total of 178 critically ill children were selected from the PICU of the Children's Hospital of Nanjing Medical University from May 2017 to June 2022. After obtaining the informed consent of the parents/guardians, basic information such as sex, age, height and weight, as well as indicators such as heart rate, systolic blood pressure and respiratory rate were collected from all children. A standard questionnaire was used to score the child 24 h after admission to the PICU. The children were divided into the survival and death groups according to their survival status at 28 d after admission. A mortality risk prediction model was constructed and nomogram was drawn. The value of the mortality risk prediction model, PEWS, PCIS and PRISM in predicting the risk of death was assessed and compared using the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC).Results:Among the 178 critically ill children, 11 cases were excluded due to severe data deficiencies and hospitalization not exceeding 24 h. A total of 167 children were included in the analysis, including 134 in the survival group and 33 in the death group. A mortality risk prediction model for children with severe bacterial infection was constructed using pupillary changes, state of consciousness, skin color, mechanical ventilation, total cholesterol and prothrombin time. ROC curve analysis showed that the AUCs of mortality risk prediction model was 0.888 ( P<0.05). The AUCs of PEWS, PCIS and PRISM Ⅲ in predicting death in children with severe bacterial infection were 0.769 ( P< 0.05), 0.575 ( P< 0.05) and 0.759 ( P< 0.05), respectively. Hosmer-Lemeshow goodness-of-fit test showed the best agreement between risk of death and PEWS predicted morbidity and mortality and actual morbidity and mortality (χ 2 = 5.180, P = 0.738; χ 2 = 4.939, P = 0.764), and the PCIS and PRISM Ⅲ predicted mortality rates fitted reasonably well with actual mortality rates (χ 2= 9.110, P= 0333; χ 2 = 8.943, P= 0.347). Conclusions:The mortality risk prediction model for predicting the death risk has better prognostic value than PEWS, PCIS and PRISM Ⅲ for children with severe bacterial infection.

Objective:To investigate the clinical effect of thoracoumbilical flap combined with random abdominal flap in repair of large-area soft tissue defects of calf in children.Methods:The clinical data of 16 children with large-area soft tissue defects of calf treated with thoracoumbilical flap combined with abdominal random flap from January 2004 to December 2007 in PLA Trauma Orthopaedic Research Institute, 80th Group Military Hospital of the PLA were retrospectively analysed. There were 7 boys and 9 girls aged 8 to 14(11.3 in average) years old. Six cases were crushed by heavy objects, 6 crushed by wheels, 3 by thermal press and 1 by machine strangulation. After thorough debridement, the wound area ranged from 16.0 cm×9.0 cm to 38.0 cm×15.0 cm. Four cases were treated after 3-10 hours of injury by emergency surgery. Twelve cases received surgeries 0-11 days after hospital admission and wound being stabilised. Doppler ultrasound was used to locate the perforating vessels according to the location, size and shape of the wound. Thoracoumbilical flap combined with abdominal random flap were designed and harvested to repair the wound. The sizes of flaps were 18.0 cm×11.0 cm-40.0 cm×16.0 cm. All patients entered follow-up at the outpatient clinic or through WeChat interviews. The appearance, texture of the flap and limb recovery were checked and recorded.Results:After surgery, all of 16 flaps survived, of which 12 flaps had phase-one healing, 3 flaps had small area of necrosis at the edge, which healed after repeated dressing changes and 1 flap developed vascular comproise, and survived after surgical exploration. The donor sites healed in phase-one. All 16 children had 6 months to16 years of follow-up, with an average of 20.7 months. The colour of the flaps was normal with soft texture. The motor function of calf was satisfactory. According to Punor functional evaluation criteria, 12 cases were in excellent and 4 in good.Conclusion:The thoracoumbilical flap combined with abdominal random flap features a reasonable design, strong blood supply and repair of a large area. It is a reliable method for repairing large area soft tissue defects in the calf of children.

New Delhi metallo-β-lactamase-1 (NDM-1) is capable of hydrolyzing nearly all β-lactam antibiotics, posing an emerging threat to public health. There are currently less effective treatment options for treating NDM-1 positive “superbug”, and no promising NDM-1 inhibitors were used in clinical practice. In this study, structure–activity relationship based on thiosemicarbazone derivatives was systematically characterized and their potential activities combined with meropenem (MEM) were evaluated. Compounds 19bg and 19bh exhibited excellent activity against 10 NDM-positive isolate clinical isolates in reversing MEM resistance. Further studies demonstrated compounds 19bg and 19bh were uncompetitive NDM-1 inhibitors with Ki = 0.63 and 0.44 μmol/L, respectively. Molecular docking speculated that compounds 19bg and 19bh were most likely to bind in the allosteric pocket which would affect the catalytic effect of NDM-1 on the substrate meropenem. Toxicity evaluation experiment showed that no hemolysis activities even at concentrations of 1000 mg/mL against red blood cells. In vivo experimental results showed combination of MEM and compound 19bh was markedly effective in treating infections caused by NDM-1 positive strain and prolonging the survival time of sepsis mice. Our finding showed that compound 19bh might be a promising lead in developing new inhibitor to treat NDM-1 producing superbug.

Objective:To explore the short-term outcomes of a 3D printed trabecular block cage to assist posterior internal fixation for the treatment of patients with basilar invagination and atlantoaxial dislocation.Methods:Between June 2017 and February 2019, 12 patients with basilar invagination and atlantoaxial dislocation underwent atlantoaxial distraction and posterior internal fixation at Department of Orthopedics, The First Affiliated Hospital to Zhengzhou University. They were 5 males and 7 females, aged from 34 to 62 years (average, 45.6 years). 3D printed cages were inserted intraoperatively between the joints of the atlantoaxial lateral mass. The atlanto-dental interval interval (ADI), cervico-medullary angle (CMA) and distance from tip of the odontoid process to Chamberlain's line (DOCL) and the Japanese Orthopedic Association (JOA) scale were compared between preoperation and 12 months postoperation to observe the fusion of the joints of the atlantoaxial lateral mass.Results:Operation went on uneventfully in all the 12 patients. Operation time averaged 116.5 min (from 85 to 190 min), fluoroscopy frequency 9.4 times (from 6 to 21 times), and intraoperative bleeding 82.3 mL (from 50 to 210 mL). No such postoperative complications occurred as cerebrospinal leak, cerebral infarction, or breakage, displacement or loosening of implants. All patients were followed up for 18 to 42 months (mean, 26.3 months). Their preoperative JOA, ADI, CMA and DOCL [8.33±0.98, (8.66±1.64) mm, 119.63°±4.15° and (9.66±2.15) mm] were significantly improved to 14.17±1.03, (2.63±0.59) mm, 153.76°±7.88° and (2.07±0.69) mm ( P<0.05) at 12 months postoperation. Bony fusion was achieved in all the operative segments. Conclusion:In the treatment of patients with basilar invagination and atlantoaxial dislocation, a 3D-printed trabecular block cage can be used to assist posterior internal fixation to achieve satisfactory reduction and maintain the height of joint space, leading to satisfactory short-term outcomes.

Objective:To explore the MRI features of cerebral amyloid angiopathy-related inflammation (CAA-ri).Methods:The clinical and imaging data of 12 patients with CAA-ri diagnosed in Affiliated Guizhou Aviation Industry Cor Ltd No 300 Hospital of Zunyi Medical University (9 cases), Xingyi People′s Hospital (2 cases) and Anshun people′s Hospital (1 case) from June 2013 to June 2020 were analyzed retrospectively. There were 3 females and 9 males, aged from 57 to 89 years old, with an average age of 71±10 years. The twelve patients included 5 cases with probable CAA-ri and 7 cases with possible CAA-ri. The duration of the disease ranged from 30 minutes to 2 years. One patient has ApoE ε4/ε4 gene overexpressed. All the 12 patients underwent MRI, including susceptibility weighted imaging in 12 cases, DWI in 10 cases, contrast enhanced MRI (CE-MRI) in 9 cases, MRS in 3 cases, MRA in 7 cases, and perfusion-weighted imaging in 1 case.Results:Imaging features of CAA-ri included encephalopathic, tumoral, classical cerebral amyloid angiopathy(CAA) manifestations. Twelve cases of encephalopathic manifestations showed patchy white matter hyperintensity (WMH) involving U-shaped fibers on T 2 weighted fluid-attenuated inversion recovery sequence (FLAIR), usually asymmetric,with various degree of mass effect, no diffusion restriction on DWI and no enhancement on CE-MRI. One case showed a single tumoral lesion with irregular enhancement on CE-MRI. The classic CAA findings included hemorrhagic lesions (microhemorrhage in 8 cases, lobar hemorrhage in 6 cases, subarachnoid hemorrhage in 3 cases, iron deposition on the brain surface in 7 cases) and ischemic lesions (microinfarction in 1 case, enlarged perivascular space and interlobar space in 4 cases). Follow-up showed lesions absorption and/or new lesion formation in 5 cases. Conclusions:The MRI features of CAA-ri are mainly patchy WMH involving U-shaped fibers on T 2 FLAIR, usually asymmetric, with wandering and alternating features, and inconsistency with clinical manifestations.