Melanoma is characterized by high malignancy, ranking the third among skin malignancies, and is associated with lack of specific treatment options and poor prognosis. Therefore, the development of effective therapies for melanoma is imperative. A critical challenge in addressing subcutaneous disease lies in overcoming the skin barrier. In this study, we engineered a microneedle (MN) system that integrates chemotherapy, photothermal therapy (PTT), and targeted therapy to enhance anti-tumor efficacy while effectively penetrating the skin barrier. In vitro studies have demonstrated that the MN drug delivery system (DDS) can effectively penetrate the stratum corneum of the skin, deliver therapeutics to subcutaneous tumor sites, and establish a drug reservoir at these locations to exert anti-tumor effects. Cellular experiments indicated that the engineered PTT chemotherapy-targeted MNs can be internalized by tumor cells, exhibiting enhanced cytotoxicity against them. In vivo pharmacological investigations revealed that the combination of PTT and chemotherapy delivered via this MN DDS produced synergistic anti-tumor effects, achieving a tumor inhibition rate of up to 98.15%. This in situ DDS minimizes involvement with other organs, significantly reducing chemotherapy-related side effects. In summary, the PTT chemotherapy-targeted MNs developed in this study demonstrate promising application potential by enhancing anti-tumor efficacy while minimizing adverse effects.

Objective:Papillary thyroid carcinoma with a maximum tumor diameter of ≤1 cm was defined as papillary thyroid carcinoma (PTC). To explore the clinical risk factors of central lymph node metastasis (CLNM) in PTC at different locations.Methods:The clinical and pathological data of 1383 cases with solitary PTC in Hangzhou First People’s Hospital were retrospectively analyzed, and they were divided into isthmus group (175 cases), near-isthmus group (95 cases) and lateral lobe group (1113 cases) according to their tumor location. Univariate and multivariate analyses were used to analyze the relationship between gender, age, tumor maximum diameter, Hashimoto’s thyroiditis (HT) and CLNM, and the threshold for the occurrence of CLNM in each group of age and tumor maximum diameter was determined by the area under the receiver operating characteristic (ROC) .Results:The proportion of CLNM in the isthmus group, near-isthmus group and the lateral lobe group were 39.4% (69/175), 35.8% (34/95) and 29.6% (329/1113), respectively ( χ2=7.84, P=0.020). The intra-group comparison showed that there were statistical differences between the isthmus group and the lateral lobe group ( χ2=6.90, P=0.011), and there were no statistical differences between the isthmus group and near-isthmus group ( χ2=0.35, P=0.601), and near-isthmus group and the lateral leaf group ( χ2=1.62, P=0.313). Univariate and multivariate analysis showed that male ( OR: 3.697) and age < 38.5 years ( OR: 4.727) were independent risk factors for CLNM in PTC in the Isthmus Group, while male ( OR: 2.193), without HT ( OR: 1.702), tumor maximum diameter > 6.5 mm ( OR: 2.535) and age < 45.5 years ( OR: 3.030) were independent risk factors for CLNM in PTC in the lateral lobe group. Conclusions:Male sex and age are independent risk factors for CLNM in isthmus and lateral lobe PTC, and uncomplicated HT and tumor maximum diameter are also independent risk factors for CLNM in lateral lobe PTC. The incidence of CLNM in PTC in the isthmus, near-isthmus and lateral lobes decreased sequentially, and PTC in the near isthmus can not be simply regarded as the isthmus or lateral lobe PTC, and the lymph nodes in the central area should be fully evaluated before surgery to provide individualized treatment.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:Papillary thyroid carcinoma with a maximum tumor diameter of ≤1 cm was defined as papillary thyroid carcinoma (PTC). To explore the clinical risk factors of central lymph node metastasis (CLNM) in PTC at different locations.Methods:The clinical and pathological data of 1383 cases with solitary PTC in Hangzhou First People’s Hospital were retrospectively analyzed, and they were divided into isthmus group (175 cases), near-isthmus group (95 cases) and lateral lobe group (1113 cases) according to their tumor location. Univariate and multivariate analyses were used to analyze the relationship between gender, age, tumor maximum diameter, Hashimoto’s thyroiditis (HT) and CLNM, and the threshold for the occurrence of CLNM in each group of age and tumor maximum diameter was determined by the area under the receiver operating characteristic (ROC) .Results:The proportion of CLNM in the isthmus group, near-isthmus group and the lateral lobe group were 39.4% (69/175), 35.8% (34/95) and 29.6% (329/1113), respectively ( χ2=7.84, P=0.020). The intra-group comparison showed that there were statistical differences between the isthmus group and the lateral lobe group ( χ2=6.90, P=0.011), and there were no statistical differences between the isthmus group and near-isthmus group ( χ2=0.35, P=0.601), and near-isthmus group and the lateral leaf group ( χ2=1.62, P=0.313). Univariate and multivariate analysis showed that male ( OR: 3.697) and age < 38.5 years ( OR: 4.727) were independent risk factors for CLNM in PTC in the Isthmus Group, while male ( OR: 2.193), without HT ( OR: 1.702), tumor maximum diameter > 6.5 mm ( OR: 2.535) and age < 45.5 years ( OR: 3.030) were independent risk factors for CLNM in PTC in the lateral lobe group. Conclusions:Male sex and age are independent risk factors for CLNM in isthmus and lateral lobe PTC, and uncomplicated HT and tumor maximum diameter are also independent risk factors for CLNM in lateral lobe PTC. The incidence of CLNM in PTC in the isthmus, near-isthmus and lateral lobes decreased sequentially, and PTC in the near isthmus can not be simply regarded as the isthmus or lateral lobe PTC, and the lymph nodes in the central area should be fully evaluated before surgery to provide individualized treatment.

BACKGROUND:The asymmetrical biomechanical environment of adolescent idiopathic scoliosis can lead to further wedge deformation of the vertebral body,which may affect cardiopulmonary function and compress nerves in severe cases.Adolescent idiopathic scoliosis with different degrees of scoliosis should be treated with exercise,bracing,and surgery.However,the mechanical mechanism of selecting an orthopedic approach remains unclear due to the individual variability of patients.OBJECTIVE:To investigate the biomechanical mechanism of different orthopedic modalities for the treatment of adolescent idiopathic scoliosis to provide a basis for clinical selection of treatment modalities based on the spine model of adolescent idiopathic scoliosis patients.METHODS:Based on the CT images of an adolescent idiopathic scoliosis patient,a scoliosis model(C7-L5)was reconstructed in Mimics software in three dimensions,and lateral thrust force was applied at the T8/T9 thorax and vertical distraction force was applied over the C7 vertebra with the magnitude of 20,40,60,80,100,and 120 N.The intervertebral disc stress and vertebral displacement in concave and convex sides,and Cobb angle of the spine were analyzed under two orthopedic modalities.RESULTS AND CONCLUSION:(1)With lateral thrust,there was no significant change in the C7T1-T7T8 intervertebral disc.The concave and convex stress of T7T8-L4L5 segment decreased first and then increased with the increase of lateral thrust force.The correction effect of lateral thrust on the segment near T8T9 was obvious and weakened with the extension of the segment to the cephalic and caudal ends.At 120 N of lateral thrust,the thoracic Cobb angle changed from 53.2° to 32.5° and the lumbar Cobb angle changed from 50.2° to 43.9°.(2)With the vertical distraction,the thoracic intervertebral disc stresses first decreased and then increased,and all the lumbar disc stresses decreased.The C7 displacement was the most obvious,and the correction effect gradually diminished with the segment extended to the caudal end.At a vertical distraction force of 120 N,the thoracic Cobb angle changed from 53.2° to 39.4° and the lumbar Cobb angle changed from 50.2° to 47.6°.(3)It is concluded that both orthopedic modalities provide improvement in the degree of scoliosis,with the thoracic correction being greater than the lumbar correction.Also,the asymmetric stress distribution on the concave and convex sides is improved,which contributes to normal bone growth.A vertical distraction approach is appropriate for larger Cobb angles,and a lateral thrust approach is appropriate for smaller Cobb angles.The results of this study help to understand the mechanism of spinal orthosis and provide a theoretical basis for the choice of orthopedic approach.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:To explore the effects of posterior malleolar fracture fixation on the rotational stability of the ankle joint.Methods:A total of 20 fresh cadaveric specimens of lower limbs were anatomized to measure the area of attachment of the posterior inferior tibiofibular ligament and transverse ligament complex to the posterior surface of the tibia. One healthy volunteer was selected to construct a finite element model for the intact tibiofibular and ankle joints and finite element models for posterior malleolar fracture with different posterior projection areas. A load of 600 N was vertically applied to the inferior calcaneus along the tibial mechanical axis. The contact area and maximum Von Mises stress of the distal tibial articular surface were analyzed to verify the validity of the model for the intact tibiofibular and ankle joints. In the finite element models for the posterior malleolar fracture (S, 1/2S, 1/4S, 1/8S and 1/16S model groups, with S standing for the complete projection area of the ligament complex on the posterior surface of the tibia), the width increase in the tibiofibular clear space was measured when a vertical load of 600 N and external rotation load of 5 N·m were applied to the ankle joint after the reduction and fixation of posterior malleolar fracture. The cutoff value of the posterior projection area of posterior malleolar fracture that could maintain the rotational stability of the ankle joint was assessed.Results:The measurement results of the cadaveric specimens showed that the area of attachment of the posterior inferior tibiofibular ligament and transverse ligament complex to the posterior surface of the tibia was relatively large. It was attached to the posterolateral area of the distal tibia with the highest point located at (45.2±5.6)mm from the articular surface. With the increase in the distance from the joint line, the width of the posterior attachment area of the ligament complex was decreased. Results of the finite element analysis showed that in the finite element model for the intact tibiofibular and ankle joints, the tibiotalar joint contact area was 324.02 mm 2 and the maximum Von Mises stress was 4.495 1 MPa with a vertical load of 600 N. In the finite element models for the posterior malleolar fracture, the distal tibiofibular clear spaces of the S, 1/2S, 1/4S and 1/8S model groups increased by less than 2 mm following loading, while it was increased by 3.445 8 mm in the 1/16S model group. The cutoff value of the posterior tibial projection area that could maintain the rotational stability of the ankle joint was 1/8S. Conclusions:The attachment area of the posterior inferior tibiofibular ligament and transverse ligament complex to the posterior surface of the tibia is large. Both the axial stability and rotational stability of the ankle joint should be considered in the treatment selection for posterior malleolar fracture. Simple posterior malleolar fixation is recommended to restore the rotational stability and axial stability of the ankle joint when tibiofibular syndesmosis is unstable and the cutoff value is larger than or equal to 1/8, while tibiofibular syndesmosis screws must be implanted when tibiofibular syndesmosis is unstable and the cutoff value is less than 1/8.

ObjectiveTo clarify the relationship between intestinal flora and intestinal motility in rats with slow transit constipation （STC） and qi stagnation syndrome by conducting a pseudo-sterile experiment and fecal microbiota transplantation （FMT） technology. MethodsTwenty-four Wistar rats were randomly divided into normal group （n=6）， STC with qi stagnation pattern group （n=6） and pseudo-sterile group （n=12）. In the STC group with qi stagnation pattern， 3 mg/kg of loperamide suspension by intragastric administration combined with tail clamping stimulation were performed to establish the rat model of STC with qi stagnation pattern. After successful modeling， fresh feces from the rats in the STC with qi stagnation pattern group and the normal group were collected to prepare 100 mg/ml of fecal bacterial suspension. In the pseudo-sterile group， the antibiotic cocktail method was used （a mixed antibiotic suspension containing bacitracin， streptomycin sulfate， and neomycin sulfate at 20 mg/ml each was administered intragastrically） to establish pseudo-sterile rats model. After successful modeling， the rats were randomly divided into normal fecal bacterial liquid group and STC with qi stagnation pattern fecal bacterial liquid group， with six rats in each group， and then were given 10 ml/kg of the prepared corresponding rat fecal bacterial suspension by gavage. Rats in STC with qi stagnation pattern group were given an equal volume of sterile water by gavage. All groups were administered once a day for 7 consecutive days. The small intestinal propulsion rate of the STC with qi stagnation pattern group， the normal fecal bacterial liquid group， and STC with qi stagnation pattern fecal bacterial liquid group were compared. ELISA method was used to detect serum 5-hydroxytryptamine （5-HT） levels. Immunohistochemistry was used to detect the positive expression levels of 5-hydroxytryptamine 3 receptor （5-HT3R） and 5-hydroxytryptamine 4 receptor （5-HT4R） in colon tissue. Western blot method was used to detect the protein expression levels of tryptophan hydroxylase 1 （TPH1）， tryptophan hydroxylase 2 （TPH2）， serotonin transporter （SERT）， and monoamine oxidase A （MAO-A） in colon tissue. ResultsCompared to those in the normal fecal bacterial liquid group， the small intestinal propulsion rate， serum 5-HT level， positive expression of 5-HT3R and 5-HT4R in colon tissue， and protein expression of TPH1， TPH2， SERT and MAO-A significantly decreased in the STC with qi stagnation pattern group and STC with qi stagnation pattern fecal bacterial liquid group （P＜0.05）. There was no statistically significant difference in the indicators between the STC with qi stagnation pattern group and STC with qi stagnation pattern fecal bacterial liquid group （P＞0.05）. ConclusionThe intestinal flora in STC rats with qi stagnation pattern can lead to a slowdown in intestinal transmission function， whose mechanism may be related to intestinal motility disorders affected by the synthesis， transport， metabolism and other pathways of 5-HT.

Objective To investigate the status and the influencing factors of thyroid volume of children aged 8-10 years in Tianjin. Methods Among the 1-2 primary schools were randomly selected from 12 districts in Tianjin. A total of 1 090 children were selected by class cluster sampling method (half male and half female, with a balanced age distribution). A questionnaire survey was conducted. Children’s height, weight and thyroid volume were measured, and their salt iodine content and urinary iodine content were detected. Results I n this study, the median urinary iodine in children was 161.35 µg/L, the mean thyroid volume was 2.56 mL, and the goiter rate was 3.58%. Univariate analysis showed that age, BSA, salt iodine content, urinary iodine content, eating habits, food taste, eating lunch at school, father's work, anxiety and depression, pressure, and different regional grouping were the influencing factors of thyroid volume (P<0.05). Multivariate linear regression showed that BSA, age, food taste, and urinary iodine content had significant independent effects on thyroid volume (P<0.05). Conclusion In Tianjin, the iodine nutrition level of children aged 8-10 years is at an appropriate level. When evaluating the thyroid volume of children, in addition to age factors, other factors such as physical development level and iodine intake should also be considered.