Objective To externally validate a prediction model based on clinical and CT imaging features for the preoperative identification of high-grade patterns (HGP), such as micropapillary and solid subtypes, in early-stage lung adenocarcinoma, in order to guide clinical treatment decisions. Methods This study conducted an external validation of a previously developed prediction model using a cohort of patients with clinical stage ⅠA lung adenocarcinoma from the Fourth Hospital of Hebei Medical University. The model, which incorporated factors including tumor size, density, and lobulation, was assessed for its discrimination, calibration performance, and clinical impact. Results A total of 650 patients (293 males, 357 females; age range: 30-82 years) were included. The validation showed that the model demonstrated good performance in discriminating HGP (area under the curve>0.7). After recalibration, the model's calibration performance was improved. Decision curve analysis (DCA) indicated that at a threshold probability>0.6, the number of HGP patients predicted by the model closely approximated the actual number of cases. Conclusion This study confirms the effectiveness of a clinical and imaging feature-based prediction model for identifying HGP in stage ⅠA lung adenocarcinoma in a clinical setting. Successful application of this model may be significant for determining surgical strategies and improving patients' prognosis. Despite certain limitations, these findings provide new directions for future research.

OBJECTIVE: To investigate whether adding 1 transverse screw (TS) to the triangular parallel cannulated screw (TPCS) fixation has a mechanical stability advantage for Pauwels type Ⅲ femoral neck fractures by conducting finite element analysis on four internal fixation methods. METHODS: Based on CT data of a healthy adult male volunteer's femur, three Pauwels type Ⅲ femoral neck fracture models (Pauwels angle 70°, Pauwels angle 80°, and Pauwels angle 70° combined with bone defect) were constructed using Mimics 21.0 software and SolidWorks 2017 software. Four different internal fixation models were built at the same time, including TPCS, TPCS+TS, three cross screws (TCS), and TPCS+medial buttress plate (MBP). The mechanical stability of different models under the same load was compared by finite element analysis. RESULTS: The femoral model established in this study exhibited a maximum stress of 28.62 MPa, with relatively higher stress concentrated in the femoral neck. These findings were comparable to previous studies, indicating that the constructed femoral finite element model was correct. The maximum stress of internal fixation in finite element analysis showed that TCS was the lowest and TPCS+MBP was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. The maximum displacement of internal fixation in each fracture model was located at the top of the femoral head, with TCS having the highest maximum displacement of the femur. The maximum stress of fracture surface in finite element analysis showed that TCS was the lowest and TPCS was the highest in the Pauwels angle 70° model, while TPCS+MBP was the lowest and TPCS/TCS were the highest in the Pauwels angle 80° model and the Pauwels angle 70° combined with bone defect model, respectively. The maximum displacement of fracture surfece analysis showed that TPCS+MBP was the lowest and TCS was the highest in Pauwels angle 70° and 80° models, while TPCS+TS was the lowest and TCS was the highest in Pauwels angle 70° combined with bone defect model. CONCLUSION For Pauwels type Ⅲ femoral neck fractures, the biomechanical stability of TPCS+TS was superior to that of TPCS alone and TCS, but it has not yet reached the level of TPCS+MBP.
Finite Element Analysis ; Humans ; Femoral Neck Fractures/diagnostic imaging* ; Bone Screws ; Fracture Fixation, Internal/instrumentation* ; Male ; Bone Plates ; Stress, Mechanical ; Biomechanical Phenomena ; Tomography, X-Ray Computed ; Adult ; Femur Neck/surgery*

OBJECTIVE: To explore the effectiveness of free paraumbilical perforator flaps in repairing skin and soft tissue defects in children. METHODS: Between February 2018 and March 2024, 12 children with skin and soft tissue defects were treated with the free paraumbilical perforator flaps. There were 7 boys and 5 girls with an average age of 6.3 years (range, 2-12 years). The defects located on the upper limbs in 6 cases, lower limbs in 5 cases, and neck in 1 case. The causes of wounds included 7 cases of electrical burns, 1 case of thermal burn, 2 cases of scar release and excision due to scar contraction after burns, 1 case of scar ulcer at the amputation stump after severe burns, and 1 case of skin necrosis after a traffic accident injury. The size of defects after debridement ranged from 7.0 cm×4.0 cm to 18.0 cm×10.0 cm. According to the defect size, 11 cases were repaired with unilateral paraumbilical perforator flaps centered on the umbilicus, among which 3 cases with larger defects were designed as "L"-shaped flaps along the lateral and lower ends of the perforator; the donor sites were directly closed. One case with extensive defect after scar excision and release was repaired with bilateral expanded paraumbilical perforator flaps; the donor sites were repaired with autologous split-thickness skin grafts. The size of flaps ranged from 9.0 cm×4.0 cm to 20.0 cm×11.0 cm. Postoperatively, analgesia and sedation were provided, and the blood supply of the flaps was observed. RESULTS: All operations were successfully completed. The operation time was 4-7 hours, with an average of 5.0 hours. After postoperative analgesia and sedation, the visual analogue scale (VAS) score for pain in all children was less than or equal to 3, and there was no non-cooperation due to pain. All flaps and skin grafts survived completely, and the wounds healed by first intention. Ten children underwent 1-4 times of flap de-fatting, finger separation, and trimming. All children were followed up 6-48 months (mean, 26.6 months). No obvious swelling of the flaps occurred, and the texture was soft. At last follow-up, among the 6 children with upper limb defects, 2 had upper limb function grade Ⅳ and 4 had upper limb function grade Ⅴ according to the Carroll upper limb function assessment method. The 4 children with lower limb defects had no limitation of joint movement. The neck flexion and rotation in the 1 child with neck defect significantly improved when compared with that before operation. The 1 child with residual ulcer at the amputation stump could wear a prosthesis and move without limitation, and no new ulcer occurred. Linear scars were left at the donor sites, and no abdominal wall hernia was formed. CONCLUSION The free paraumbilical perforator flap has abundant blood supply and can be harvested in large size. It can be used to repair skin and soft tissue defects in children and has the advantages of short operation time, minimal injury, high safety, and minimal impact on the growth and development of children.
Humans ; Perforator Flap/transplantation* ; Child ; Male ; Female ; Soft Tissue Injuries/surgery* ; Child, Preschool ; Plastic Surgery Procedures/methods* ; Burns/surgery* ; Umbilicus/surgery* ; Skin Transplantation/methods* ; Skin/injuries* ; Cicatrix/surgery* ; Treatment Outcome

OBJECTIVE: To explore the construction of a canine model of vascularized allogeneic spinal cord transplantation (vASCT) and preliminarily evaluate its therapeutic efficacy for spinal cord injury (SCI). METHODS: Sixteen female Beagle dogs aged 8-12 months were randomly selected, with 8 dogs serving as donors for the harvesting of spinal cord tissue with a vascular pedicle [dorsal intercostal artery (DIA) at the T₁₀ level and accompanying vein]. The remaining 8 dogs underwent a 1.5-cm-length spinal cord defect at the T₁₀ level, followed by transplantation of the donor spinal cord tissue for repair. Polyethylene glycol (PEG) was applied to both ends to spinal cord graft; then, using a random number table method, the dogs were divided into an experimental group (n=4) and a control group (n=4). The experimental group received immunosuppressive intervention with oral tacrolimus [0.1 mg/(kg∙d)] postoperatively, while the control group received no treatment. The operation time and ischemia-reperfusion time of two groups were recorded. The recovery of hind limb function was estimated by Olby score within 2 months after operation; the motor evoked potentials (MEP) was measured through neuroelectrophysiological examination, and the spinal cord integrity was observed through MRI. RESULTS: There was no significant difference in the operation time and ischemia-reperfusion time between the two groups (P>0.05). All dogs survived until the completion of the experiment. Within 2 months after operation, all dogs in the control group failed to regain the movement function of hind limbs, and Olby scores were all 0. In the experimental group, the movement and weight-bearing, as well as walking abilities of the hind limbs gradually recovered, and the Olby scores also showed a gradually increasing trend. There was a significant difference between the two groups from 3 to 8 weeks after operation (P<0.05). Neuroelectrophysiological examination indicated that the electrical signals of the experimental group passed through the transplanted area, and the latency was shortened compared to that at 1 month after operation (P<0.05), showing continuous improvement, but the amplitude did not show significant improvement (P>0.05). The control group was unable to detect any MEP changes after operation. MRI examination showed that the transplanted spinal cord in the experimental group survived and had good continuity with normal spinal cord tissue, while no relevant change was observed in the control group. CONCLUSION The vASCT model of dogs was successfully constructed. This surgical procedure can restore the continuity of the spinal cord. The combination of tacrolimus anti-immunity is a key factor for the success of transplantation.
Animals ; Dogs ; Female ; Spinal Cord/blood supply* ; Spinal Cord Injuries/surgery* ; Transplantation, Homologous ; Disease Models, Animal ; Recovery of Function ; Plastic Surgery Procedures/methods* ; Tacrolimus ; Immunosuppressive Agents

OBJECTIVE: To compare effectiveness of multiple metatarsal osteotomy versus first metatarsophalangeal arthrodesis in treating severe metatarsal adductus hallux valgus deformity. METHODS: A retrospective analysis was conducted on the clinical data of 25 patients with severe metatarsal adductus hallux valgus deformity admitted between June 2010 and May 2014 who met the selective criteria. Among them, 15 patients underwent multiple metatarsal osteotomy (osteotomy group), while 10 patients underwent first metatarsophalangeal arthrodesis (fusion group). There was no significant difference between groups ( P>0.05) in gender, age, disease duration, affected side, preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) score for pain, intermetatarsal angle (IMA), hallux valgus angle (HVA), or metatarsal adduction angle (MAA). The osteotomy group underwent fixation with screws and/or staples fixation, while the fusion group utilized anatomic fusion plates and trans-articular compression screws. The study compared the following outcome indicators between groups: operation time, pre- and post-operative differences (change values) in AOFAS scores, VAS scores, and radiographic parameters (HVA, MAA), osteotomy healing outcomes, and recurrence of hallux valgus deformity. RESULTS: Both surgical procedures were completed successfully. The operation time was significantly shorter in the fusion group than in the osteotomy group ( P<0.05). All patients were followed up 96-144 months (mean, 116 months). The follow-up time was (129.1±7.2) months in the osteotomy group and (104.4±8.0) months in the fusion group, with no significant difference between groups ( P>0.05). X-ray films revealed the radiographic union in two groups, and the fusion time was significantly shorter in the fusion group than in the osteotomy group ( P<0.05). At last follow-up, both groups demonstrated significant improvements in AOFAS and VAS scores compared to preoperative levels ( P<0.05). However, the differences in the change values of AOFAS and VAS scores between groups were not significant ( P>0.05). During follow-up, 3 cases (20%) of deformity recurrence occurred in the osteotomy group, while no recurrence was observed in the fusion group. There was no significant difference in the incidences of deformity recurrence between groups ( P>0.05). CONCLUSION For severe metatarsus adductus hallux valgus deformities, both multiple metatarsal osteotomy and first metatarsophalangeal arthrodesis can correct the deformity. The former preserves metatarsophalangeal joint mobility but demands high technical proficiency from the surgeon, involves relatively longer operation times, extended bone healing periods, and higher complication incidences. The latter procedure is relatively simpler, facilitates faster postoperative recovery, allows early weight-bearing, and yields more reliable outcomes, though it sacrifices first metatarsophalangeal joint mobility.
Humans ; Osteotomy/methods* ; Hallux Valgus/diagnostic imaging* ; Retrospective Studies ; Arthrodesis/instrumentation* ; Treatment Outcome ; Metatarsal Bones/diagnostic imaging* ; Metatarsophalangeal Joint/diagnostic imaging* ; Male ; Female ; Bone Screws ; Adult ; Middle Aged ; Bone Plates ; Pain Measurement

OBJECTIVE: To explore the feasibility and effectiveness of repairing surgical defect in pharyngo-laryngeal malignant tumor with free rectus femoris flap. METHODS: The clinical data of 34 patients with surgical defects in pharyngo-laryngeal malignant tumor who met the selection criteria between July 2014 and August 2024 were retrospectively analyzed. There were 25 males and 9 females, aged 25-82 years, with a median age of 54 years. The disease duration ranged from 2 months to 2 years, with a median of 7 months. The tumor locations included the oropharynx, hypopharynx, cervical esophagus, and larynx. Pathological types included squamous cell carcinoma (29 cases), myoepithelial carcinoma (2 cases), adenoid cystic carcinoma (1 case), and diffuse large B-cell lymphoma (2 cases). TNM staging: 16 cases of T ₄N ₁M ₀, 3 cases of T ₄N ₂M ₀, 3 cases of T ₄N ₀M ₀, 10 cases of T ₃N ₁M ₀, and 2 cases of T ₃N ₀M ₀. The 2017 American Joint Committee on Cancer (AJCC) staging was stage Ⅲ in 2 cases and stage Ⅳ in 32 cases. The blood supply of the proximal rectus femoris muscle was observed by enhanced CT of the lower limb vessels before operation, and the surgical defects ranged from 3.0 cm×2.0 cm to 12.0 cm×8.5 cm. The blood supply and perforators of rectus femoris muscle were explored during operation, and the free rectus femoris flap pedicled with the direct vascular stem of rectus femoris muscle was used to repair the defect. For the patients with pharyngeal fistula or obvious neck swelling after operation, the blood supply of the flap was analyzed by vascular enhanced CT to determine the corresponding strategies of nutritional support, anti-infection, dressing change and drainage. Radiotherapy and chemotherapy were supplemented in 27 patients with lymph node metastasis after operation. RESULTS: All the 34 patients were followed up 1-10 years, with an average of 3 years. The flap was found to be necrotic by fibrolaryngoscopy at 1 week after operation in 2 cases, and the incision healed after dressing change and nutritional support, and no reoperation was performed. The flap was in good condition at 1 week after operation in 4 cases, and the signs of gradual necrosis of the flap were found within 1 month after operation, of which 2 cases were healed after dressing change, 1 case was removed the necrotic tissue by reoperation, and 1 case was healed after pectoralis major myocutaneous flap was used to repair the pharyngeal tissue defect. The flaps survived in 28 cases, including 4 cases of pharyngeal fistula, which healed by dressing change. Twenty-two cases achieved satisfactory results in swallowing or phonation. Two patients with total laryngectomy and voice reconstruction underwent reoperation to seal the voice tube because of postoperative aspiration. During the follow-up, 1 case had tracheal stomal recurrence, 2 cases had bone metastasis, and 1 case had bone and lung metastasis. CONCLUSION The free rectus femoris flap has good flexibility, the volume of the flap is easy to adjust, and the incision of the donor site is concealed, which is expected to become a new choice for the repair of the surgical defect in pharyngo-laryngeal malignant tumor.
Humans ; Male ; Middle Aged ; Female ; Aged ; Adult ; Plastic Surgery Procedures/methods* ; Retrospective Studies ; Laryngeal Neoplasms/pathology* ; Aged, 80 and over ; Pharyngeal Neoplasms/pathology* ; Free Tissue Flaps/blood supply* ; Quadriceps Muscle/transplantation* ; Surgical Wound/surgery* ; Treatment Outcome

The transmission and interaction of neural information between the hippocampus and the prefrontal cortex play an important role in learning and memory. However, the specific effects of learning memory-related tasks on the connectivity characteristics between these two brain regions remain inadequately understood. This study employed in vivo microelectrode recording to obtain local field potentials (LFPs) from the ventral hippocampus (vHPC) and medial prefrontal cortex (mPFC) in eight rats during the performance of a T-maze task, assessed both before and after task learning. Additionally, dynamic causal modeling (DCM) was utilized to analyze alterations in causal connectivity between the vHPC and the mPFC during memory task execution pre- and post-learning. Results indicated the presence of forward connections from vHPC to mPFC and backward connections from mPFC to vHPC during the T-maze task. Moreover, the forward connection between these brain regions was slightly enhanced after task learning, whereas the backward connection was diminished. These changes in connectivity corresponded with the observed trends when the rats correctly performed the T-maze task. In conclusion, this study may facilitate future investigations into the underlying mechanisms of learning and memory from the perspective of connectivity characteristics between distinct brain regions.
Animals ; Hippocampus/physiology* ; Rats ; Prefrontal Cortex/physiology* ; Memory/physiology* ; Maze Learning/physiology* ; Learning/physiology* ; Male

Magnetic ferrite nanoparticles (MFNPs) have great application potential in biomedical fields such as magnetic resonance imaging, targeted drugs, magnetothermal therapy and gene delivery. MFNPs can migrate under the action of a magnetic field and target specific cells or tissues. However, to apply MFNPs to organisms, further modifications on the surface of MFNPs are required. In this paper, the common modification methods of MFNPs are reviewed, their applications in medical fields such as bioimaging, medical detection, and biotherapy are summarized, and the future application directions of MFNPs are further prospected.
Ferric Compounds ; Magnetic Resonance Imaging/methods* ; Magnetics ; Magnetite Nanoparticles/therapeutic use* ; Nanoparticles

Medical image segmentation based on deep learning has become a powerful tool in the field of medical image processing. Due to the special nature of medical images, image segmentation algorithms based on deep learning face problems such as sample imbalance, edge blur, false positive, false negative, etc. In view of these problems, researchers mostly improve the network structure, but rarely improve from the unstructured aspect. The loss function is an important part of the segmentation method based on deep learning. The improvement of the loss function can improve the segmentation effect of the network from the root, and the loss function is independent of the network structure, which can be used in various network models and segmentation tasks in plug and play. Starting from the difficulties in medical image segmentation, this paper first introduces the loss function and improvement strategies to solve the problems of sample imbalance, edge blur, false positive and false negative. Then the difficulties encountered in the improvement of the current loss function are analyzed. Finally, the future research directions are prospected. This paper provides a reference for the reasonable selection, improvement or innovation of loss function, and guides the direction for the follow-up research of loss function.
Algorithms ; Image Processing, Computer-Assisted

Objective    To study the relationship between preoperative heart rate variability (HRV) and postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass grafting (OPCAB). Methods    A retrospective analysis was performed on the clinical data of 290 patients who were admitted to the Department of Cardiovascular Surgery, General Hospital of Northern Theater Command from May to September 2020 and received OPCAB. There were 217 males and 73 females aged 36-80 years. According to the incidence of POAF, the patients were divided into two groups: a non-atrial fibrillation group (208 patients) and an atrial fibrillation group (82 patients). The time domain and frequency domain factors of mean HRV 7 days before operation were calculated: standard deviation of all normal-to-normal intervals (SDNN), root mean square of successive differences, percentage difference between adjacent normal-to-normal intervals that were greater than 50 ms, low frequency power (LF), high frequency power (HF), LF/HF. Results    The HRV value of patients without POAF was significantly lower than that of patients with POAF (P<0.05). The median SDNN of the two groups were 78.90 ms and 91.55 ms, respectively. Age (OR=3.630, 95%CI 2.015-6.542, P<0.001), left atrial diameter (OR=1.074, 95%CI 1.000-1.155, P=0.046), and SDNN (OR=1.017, 95%CI 1.002-1.032, P=0.024) were independently associated with the risk of POPAF after OPCAB. Conclusion     SDNN may be an independent predictor of POAF after OPCAB.