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.

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.

BACKGROUND:Ankylosing spondylitis is a chronic inflammatory disease with chronic rheumatic immunity.Soft tissue ossification and fusion and spinal stiffness can cause biomechanical changes. OBJECTIVE:To reconstruct the lumbar-sacral intervertebral disc in ankylosing spondylitis patients with lumbar kyphosis by finite element analysis,and to study the range of motion of each segment of T11-S1 and the biomechanical characteristics of annulus fibrosus and nucleus pulposus. METHODS:The imaging data were obtained from an ankylosing spondylitis patient with lumbar kyphosis.The original CT image data of continuously scanned spine were imported into Mimics 21.0 in DICOM format,and T11-S1 was reconstructed respectively.The established model was imported into 3-Matic software in the format of"Stl"to reconstruct the intervertebral disc,and the fibrous intervertebral disc model was obtained.The improved model was further imported into Hypermesh software,and the vertebra,nucleus pulposus,annulus fibrosus and ligament were mesh-divided.After the material properties were given,the model was imported into ABAQUS software to observe the range of motion of each vertebral body in seven different working conditions of T11-S1,and analyze the biomechanical characteristics of each segment of annulus fibrosus and nucleus pulposus. RESULTS AND CONCLUSION:(1)The range of motion of L1 vertebrae was higher than that of other vertebrae under six different working conditions:extension,forward flexion,rotation(left and right),and lateral flexion(left and right).The maximum range of motion was 2.18° during L1 vertebral flexion,and the minimum range of motion was 0.12° during L5 vertebral extension.(2)The annular fiber flexion at L2-L3 segments was greater than the extension(P<0.05),and the annular fiber flexion at L3-L4 and L4-L5 segments was less than the extension(P<0.05).The left rotation of L1-L2 annular fibers was greater than the right rotation(P<0.05).The left flexion of the annulus was greater than the right flexion in L1-L2,L2-L3,L3-L4,L4-L5 and L5-S1 segments(P<0.05).(3)The nucleus pulposus stresses of T11-L12,L1-L2,L2-L3,L3-L4 and L4-L5 segments in forward flexion were greater than in extension(P<0.05).The left rotation of T12-L1 and L3-L4 segments was smaller than the right rotation(P<0.05),and that of T11-T12,L1-L2,and L2-L3 segments was larger than the right rotation(P<0.05).The left flexion was larger than the right flexion in the T11-S1 segment.(4)It is concluded that in ankylosing spondylitis patients with lumbar kyphosis,the minimum range of motion of the vertebral body is located at the L5 vertebral body in extension.To prevent fractures,it is recommended to avoid exercise in the extension position.During the onset of lumbar kyphosis in patients with ankylosing spondylitis,the maximum stress of the annulus fibrosus and nucleus pulposus is located in the L1-L2 segment,which is fixed and will not alter with the change of body position.The late surgical treatment and correction of deformity should focus on releasing the pressure of the annulus fibrosus and nucleus pulposus in this segment to avoid the rupture of the annulus fibrosus and the injury of the nucleus pulposus.