Background Metals and metalloids in fine particulate matter (PM_2.5) may cause damage to the respiratory and circulatory systems of the human body, and long-term exposure is prone to causing chronic poisoning, cancer, and other adverse effects. Objective To assess the distribution characteristics of metals and metalloids in outdoor PM_2.5 in a southern city of China, conduct source apportionment, and evaluate the associated health risks, thereby providing theoretical support for further pollution control measures. Methods PM_2.5 samples were collected in districts A, B, and C of a southern China city, and the concentrations of 17 metals and metalloids were detected by inductively coupled plasma-mass spectrometry (ICP-MS). Pollution sources were assessed through enrichment factor and principal components analysis, and the main pollution sources were quantified using absolute principal component scores-multivariate linear regression (APCS-MLR). Health risks were evaluated based on the Technical guide for environmental health risk assessment of chemical exposure (WS/T777—2021). Results The ambient air PM_2.5 concentrations in the city were higher in winter and spring, and lower in summer and autumn. The annual average concentrations of ambient PM_2.5 in districts A, B, and C were 36.7, 31.9, and 24.4 μg·m⁻³, respectively. The ambient PM_2.5 levels in districts B and C were below the second-grade limit set by the Ambient air quality standards (GB 3095—2012). The enrichment factors of cadmium (Cd), aluminum (Al), and antimony (Sb) were greater than 10, those of copper (Cu), lead (Pb), arsenic (As), nickel (Ni), mercury (Hg), and molybdenum (Mo) fell between 1 and 10, and those of manganese (Mn), vanadium (V), chromium (Cr), cobalt (Co), barium (Ba), beryllium (Be), and uranium (U) were below or equal to 1. The comprehensive evaluation of source analysis showed that the main pollution sources in districts A and C and the whole city were coal-burning. In district B, the main pollution source was also coal combustion, followed by industrial process sources and dust sources. The carcinogenic risks of As and Cr were between 1×10⁻⁶ and 1×10⁻⁴. However, the hazard quotients for 15 metals and metalloids in terms of non-carcinogenic risk were below 1. Conclusion Cr and As in the atmospheric PM_2.5 of the city present a certain risk of cancer and should be paid attention to. In addition, preventive control measures should be taken against relevant pollution sources such as industrial emission, dust, and coal burning.

Real-time acquisition of pulmonary ventilation and perfusion information through thoracic electrical impedance tomography (EIT) holds significant clinical value. This study proposes a novel method based on the rime (RIME) algorithm-optimized variational mode decomposition (VMD) to separate lung ventilation and perfusion signals directly from raw voltage data prior to EIT image reconstruction, enabling independent imaging of both parameters. To validate this approach, EIT data were collected from 16 healthy volunteers under normal breathing and inspiratory breath-holding conditions. The RIME algorithm was employed to optimize VMD parameters by minimizing envelope entropy as the fitness function. The optimized VMD was then applied to separate raw data across all measurement channels in EIT, with spectral analysis identifying relevant components to reconstruct ventilation and perfusion signals. Results demonstrated that the structural similarity index (SSIM) between perfusion images derived from normal breathing and breath-holding states averaged approximately 84% across all 16 subjects, significantly outperforming traditional frequency-domain filtering methods in perfusion imaging accuracy. This method offers a promising technical advancement for real-time monitoring of pulmonary ventilation and perfusion, holding significant value for advancing the clinical application of EIT in the diagnosis and treatment of respiratory diseases.
Humans ; Electric Impedance ; Algorithms ; Tomography/methods* ; Pulmonary Ventilation/physiology* ; Lung/diagnostic imaging* ; Image Processing, Computer-Assisted/methods* ; Adult

Objective:To compare the embrace fixation and screw fixation in the treatment of inferior tibiofibular syndesmosis injury.Methods:A retrospective study was conducted of the 125 patients who had been treated for ankle fractures and distal syndesmotic injuries at The Hospital Affiliated to Qingdao University from April 2018 to September 2021. They were 79 males and 46 females with an age of (25.4±11.2) years. The patients were divided into 2 groups according to their fixation methods: an observation group of 75 cases subjected to embrace fixation and a control group of 50 cases subjected to conventional screw fixation. Their reduction was evaluated by comparing the disparities between the affected and normal sides in the anterior and posterior syndesmotic distances, fibular translation distance, and fibular rotation angle between the 2 groups after surgery. Intraoperative immobilization time for the inferior tibiofibular syndesmosis, American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Olerud-Molander ankle function score, and visual analog scale (VAS) for pain were also compared at the last follow-up between the 2 groups.Results:There was no statistically significant difference in the preoperative baseline data between the 2 groups of patients, indicating comparability ( P>0.05). There was no statistically significant difference between the 2 groups in intraoperative immobilization time for the inferior tibiofibular syndesmosis, disparity between the injured and normal sides in postoperative fibular translation distance, or VAS pain score at the last follow-up ( P>0.05). The anterior and posterior syndesmotic distances, disparity between the injured and normal sides in fibular rotation angle, AOFAS ankle-hindfoot score, and Olerus-Molander ankle function score in the observation group [0.1 (-0.2, 0.3) mm, 0.1 (-0.3, 0.5) mm, -0.5 (-1.1, 0.8)°, 96 (93, 100) points, and 95 (90, 100) points] were all significantly better than those in the control group [1.4 (0.6, 2.1) mm, 1.5 (0.9, 2.2) mm, 1.2 (-3.8, 3.7)°, 93 (89, 96) points, and 90 (85, 100) points] (all P<0.05). There was no major complication or nonunion in the observation group. Conclusion:The embrace technique can provide an accurate and effective fixation for the inferior tibiofibular syndesmosis in patients with ankle fracture and lead to better clinical and radiographic outcomes than conventional screw fixation.

Suture techniques for microvascular anastomoses have been clinically adopted for decades. However, there are still some limitations in microvascular anastomosis. Therefore, the improvement of suture techniques for microvascular anastomosis has become the focused topics in the research of microsurgery. With the development of science and technology in microsurgery, the suture techniques, anastomotic instruments and training models for microvascular anastomoses have been continuously improved. This article summarises the progress in microvascular anastomosis based on literatures published on PubMed, Embase, Medline, CNKI and Wanfang Data, and provides a theoretical basis for promoting the development in anastomosis of microvessels.

Replantation of traumatic amputation in children has its own characteristics. This consensus primarily focuses on the issues related to the treatment of traumatically amputated limb injuries in children. Organised along a timeline, the consensus summarises domestic and international clinical experiences in emergency care and injury assessment of traumatic limb amputation limbs, indications and contraindications for replantation surgery, principles and procedures of replantation surgery, postoperative medication and management, as well as rehabilitation in children. The aim of this consensus is to propose standardise the treatment protocols for limb replantation for children therefore to serve as a reference for clinical practitioners in medical practices, and further improve the treatment and care for the traumatic limb amputations in children.

Objective: The aim of this study was to establish a comprehensive concise health index (CHI) for evaluating adolescents, so as to provide a basis for determining the overall health status of adolescents in China. Methods: On the basis of a literature review and consensus among core researchers, adolescent CHI indicators in the following five dimensions were assessed:physical growth, physical fitness, common diseases, mental health and behavioral health. A total of 24 experts used an analysis hierarcgy process (AHP) to calculate the indicators subjective weights. In addition, from October to December of 2021, two regions, A and B were selected to conduct empirical research, and the CRITIC method was used to calculate the objective weights of the indicators. Finally, the weight coefficients were determined through the AHP-CRITIC combination weight method, and comprehensive evaluation was performed with the TOPSIS method. Results: Across academic period and genders, the combined weighted coefficients of the health indicators were as follows:BMI, 0.081-0.095; waist circumference, 0.070-0.081; relative grip strength, 0.101-0.108; myopia, 0.110-0.128; dental caries, 0.055-0.070; psychological symptoms, 0.240-0.262; physical exercise, 0.085-0.115; screen time, 0.097-0.111; and sleep duration, 0.086-0.103. The health index of middle school students in city A (0.626±0.065) was significantly higher than that in city B(0.613±0.066)( t=6.34, P <0.01). Conclusion The comprehensive adolescent CHI evaluation method has good consistency and application value, and may serve as a reference for adolescent health monitoring.

Objective:To explore the surgical procedure and effect of reconstruction of soft tissue defects in the distal segment of dorsal finger with a perforator(joint branch) flap of proper palmar digital artery combined with a dorsal metacarpal artery flap.Methods:From January 2019 to June 2022, 9 patients with soft tissue defects in distal dorsal finger, mostly with avulsion at the extensor tendon insertion point, were treated in Department of Hand and Foot Microsurgery, the Affiliated Hospital of Qingdao University. The defect areas were 1.0 cm×1.0 cm-2.5 cm×2.0 cm. Steel wires were used to reconstruct the extensor tendon insertion point. The defects were reconstructed by a perforator(joint) flap of proximal phalanx artery and a dorsal metacarpal artery flap was used to repair the donor site for proximal flap. Postoperative follow-up and evaluation included flap survival, flap appearance, scars and function of interphalangeal and metacarpophalangeal joints, through outpatient clinical, WeChat and so on.Results:The flap of digital artery perforator (joint branch) and the fasciocutaneous flap of dorsal metacarpal artery all survived. One flap of the digital artery perforator(joint branch) appeared purple and tension blisters after surgery. The stitches of the pedicle of the flap were partially dismantled at 36-48 hours after surgery. The flap was then turned to ruddy in colour 7 days after surgery. The wounds of the distal finger joint and nail bed healed well without redness and infection. The postoperative follow-up lasted for 5 to 12 months, 9 months in average. The appearance, colour and texture of the skin at distal finger were similar to those at the dorsal proximal finger and dorsal palm. Sensation recovered well, all flaps exceeding S 3. The two-point resolution (TPD) was 8-10 mm, with an average of 9.5 mm. According to the Evaluation Standard of Upper Limb Partial Functional of Hand Surgery of Chinese Medical Association, 5 cases were in excellent and 4 in good. Conclusion:The perforator(joint branch) flap of proper palmar digital artery combined with a dorsal metacarpal artery flap is simple and safe treatment. It has a fast functional recovery with an aesthetic appearance in reconstruction of the soft tissue defect in distal segment of dorsal finger.

Objective:To investigate the clinical effect of bilateral anteriolateral thigh perforator flaps (ALTPF) pedicled with descending branch of lateral circumflex femoral artery in series on reconstruction of large soft tissue defects in lower limbs.Methods:A total of 9 patients with large soft tissue defects in lower limbs were selected in the study. The patients were 6 males and 3 females aged between 18 and 57 years old. They were treated in the Department of Hand and Foot Microsurgery, the Affiliated Hospital of Qingdao University from June 2018 to January 2023. Causes of injury: 4 of traffic accident, 2 of crushing, 2 of falling from height and 1 of explosion. Five patients had combined defects in dorsal feet and 4 with tibia fractures and anterior-and-posterior-tibial soft tissue defects. All affected limbs had tissue necroses and infections in various degrees. Deep tissue defects such as tendons, nerves, bones and joints or orthopaedic implants were exposed. The areas of soft tissue defects were 30 cm×14 cm-42 cm×14 cm. All the defects were reconstructed by the bilateral ALTPF pedicled with descending branch of lateral circumflex femoral artery in series. The size of proximal flaps was 25 cm×8 cm-33 cm×13 cm and 20 cm×7 cm-29 cm×13 cm for the distal flaps. Scheduled postoperative follow-ups were conducted to observe the survival of the transferred flaps and functional recovery of calfs and feet. Sensory recovery was assessed against British Medical Research Council (BMRC) criteria. Puno scoring was used to assess the functional recovery and the effectiveness of treatment.Results:All flaps survived and the donor sites healed well. One patient developed vascular compromise within 24 hours after surgery, but it was rectified after timely surgical exploration, however it left with a small area of necrosis at distal end of the flap. The necrosis and wound healed after skin grafting in stage-two surgery. Postoperative follow-up lasted for 8.3 months in average. Two patients underwent flap thinning in stage-two surgery due to bloating appearance, 2 patients had slightly bloated flaps at the calfs, and the rest of 5 patients had satisfactory flap appearance. Two patients received nerve reconstruction by anastomosis of the lateral femoral cutaneous nerves. At the final follow-up, the sensory recovery in 9 patients achieved S 2-S 3+ according to BMRC. The average Puno score achieved 88.36 point±5.36 point, of which 4 patients in excellent, 3 in good and 2 in fair. Conclusion:The use of bilateral ALTPF pedicled with descending branch of lateral circumflex femoral artery in series to reconstruct a large soft tissue defect in lower extremity has a good clinical value, and it has become one of the effective methods.

Objective:To explore the clinical application of free chimeric medial femoral condyle osteofascial free flap (CMFCOF) in the treatment of traumatic composite bone and soft tissue defect of hand and foot.Methods:Between January, 2015 and March, 2020, 8 patients with traumatic composite bone and soft tissue defect in hand and foot were treated with CMFCOF. Of the 8 patients, there were 6 males and 2 females, with an average age of 41 (range, 24 to 56) years. The causes of injury included 3 of traffic accident, 3 of machine crush and 2 of crush. Two cases had proximal phalanx defect, 3 with metacarpal bone and 3 with metatarsal bone. The time between injury to the flap repair were 2 to 120 (mean, 84) days. The size of bone defect ranged from 2.0 cm×1.2 cm×1.2 cm to 4.4 cm× 3.0 cm×2.3 cm. The soft tissue defect ranged from 2.0 cm×1.4 cm to 5.6 cm×4.5 cm. All bone defects were on the diaphysis, without involvement of joints. Two cases had tendon defect. According to the defect of bone and soft tissue, the CMFCOF was prepared and skin graft was performed on the surface of its fascial flap.Results:The average time of flap harvesting was 53(52-96) minutes. All donor sites were directly closed. All flaps and skin grafts achieved stage I survival. All patients entered 9-16 months of follow-up, with an average of 14.5 months. The average healing time of bone was 7.5 (range, 6-10) weeks. At the last follow-up review, all flaps were not thinned. The function of donor site was restored well, without weight bearing disorder and paraesthesia in the anterior patella area. According to the trial standard of Digit Function Evaluation of the Hand Surgery Society of Chinese Medical Association, 3 patients were rated as excellent, 1 was good and 1 was fair. According to the Maryland foot evaluation criteria, 3 patients were rated as excellent for recovered with normal weight-bearing walking.Conclusion:CMFCOF can achieve satisfactory results in repairing composite bone and soft tissue defect of hand or foot. The flap has the advantages in simple operation, high quality of bone and concealed donor site.

Objective: To investigate the associated factors of myopia among primary and secondary school students in Shenzhen, and to provide reference for the prevention and control of myopia. Methods: By stratified cluster sampling, 3 073 students of 14 schools including primary,junior,regular and vocational senior schools from two districts in Shenzhen were selected and investigated. Results: For primary school students, the time of using computer for 2-<3 hours per day (OR=2.23，95%CI=1.19-4.20) , and no physical education class(2 sections per week OR=0.34, 95%CI=0.13-0.91; 4 sections per week OR=0.23, 95%CI=0.08-0.62; 5 sections or more per week OR=0.33, 95%CI=0.11-0.97) were positively associated with myopia. Teachers finishing class on time at break (occasionally delaying OR=1.99, 95%CI=1.51-2.63; frequently delaying OR=2.07, 95%CI=1.29-3.30), taking 0.5-1 hour break when using eyes at close range (1-<2 hours OR=1.33，95%CI=1.03-1.70; ≥3 hours OR=1.87, 95%CI=1.17-3.00), no parents with myopia(one parent with myopia OR=1.69, 95%CI=1.32-2.17; two parents with myopia OR=2.13, 95%CI=1.50-3.02) were negatively associated with myopia. For junior high school students, without parents with myopia (one parent with myopia OR=3.27, 95%CI=2.17-4.94; two parents with myopia OR=5.38, 95%CI=2.78-10.42) was the protective factor of myopia. For senior high school students, male (female OR=1.52, 95%CI=1.07-2.14), doing eye exercises twice a day in school (OR=0.41, 95%CI=0.23-0.75), and accumulating outdoor activities for ≥2 hours a day (OR=0.70, 95%CI=0.49-1.00) were negatively associated with myopia. Conclusion There are different risk factors for myopia among different students in Shenzhen. Students with high risk factors are the key objects of prevention and control.