Objective To investigate and analyze the risk factors of cardiovascular events by low density lipoprotein cholesterol (LDL-C). Methods A total of 430 patients with stable angina pectoris (SAP) in the hospital were included from June 2021 to June 2024 for retrospective analysis. According to whether acute myocardial infarction (AMI) occurred, the enrolled patients were divided into stable group (n=257) and deteriorating group (n=173). The general data were compared between groups, and the risk factors affecting AMI in SAP patients were analyzed. The predictive value of the above risk factors on predicting AMI in SAP patients was analyzed. Results Compared with the stable group, the levels of LDL-C, TG, LP-a and Hcy in the deteriorating group were higher (t=4.033, P<0.001; t=4.104, P<0.001; t=6.342, P<0.001; t=4.883, P<0.001) while the HDL-C level was lower (t=5.129, P<0.001). Multivariate logistic regression analysis suggested that the elevated levels of LDL-C, TG, LP-a and Hcy were the risk factors of AMI in SAP patients (P<0.05), and the elevated level of HDL-C was a protective factor (P<0.05). In the ROC curve, the area under the curve (AUC), sensitivity and specificity of combination of LDL-C, HDL-C, TG, LP-a and Hcy in predicting AMI in SAP patients were 0.777, 63.01% and 81.71%. Conclusion LDL-C is a risk factor of AMI in SAP patients. Combination of HDL-C, TG, LP-a and Hcy has certain value on predicting AMI in SAP patients.

Objective:To investigate the risk factors of pleural effusion after spinal separation surgery for patients with spinal metastatic tumors.Methods:A total of 427 patients with spinal metastatic tumors from January 2014 to January 2022 in the Second Affiliated Hospital of Zhejiang University School of Medicine were retrospectively analyzed. There were 252 males and 175 females, with an average age of 59±12 years (range, 15-87 years). All patients underwent separation surgery. Based on the chest CT within 1 month after surgery, the volume of pleural effusion was measured individually by reconstruction software. Pleural effusion was defined as small volume (0-500 ml), moderate volume (500-1 000 ml), and large volume (above 1 000 ml). Baseline data and perioperative clinical outcomes were compared between the groups, and indicators with statistically significant differences were included in a binary logistic regression analysis to determine the independent risk factors for the development of pleural effusion after isolation of spinal metastatic cancer. Receiver operating characteristic (ROC) curves were conducted to calculate the area under the curve (AUC) for each independent risk factor.Results:All patients successfully completed the operation. Among the 427 patients, there were 35 cases of large pleural effusion, 42 cases of moderate pleural effusion, and 350 cases of small pleural effusion. There were significant differences in tumor size (χ 2=9.485, P=0.013), intraoperative blood loss ( Z=-2.503, P=0.011), blood transfusion ( Z=-2.983, P=0.003), preoperative total protein ( Z=2.681, P=0.007), preoperative albumin ( Z=1.720, P= 0.085), postoperative hemoglobin ( t=2.950, P=0.008), postoperative total protein ( Z=4.192, P<0.001), and postoperative albumin ( t=2.268, P=0.032) in the large pleural effusion group versus the small and moderate pleural effusion group. Logistic regression analysis showed that decreased preoperative albumin ( OR=0.89, P=0.045) and metastases located in the thoracic spine ( OR=4.01, P=0.039) were independent risk factors for the occurrence of large pleural effusion after separation surgery. The ROC curve showed that the AUC and 95% CI for preoperative albumin, lesion location, and the combined model were 0.637 (0.54, 0.74), 0.421 (0.36, 0.48), and 0.883 (0.81, 0.92). The combined predictive model showed good predictive value. Conclusion:The volume of pleural effusion can be measured individually and quantitatively based on chest CT. Decreased preoperative albumin and metastases located in the thoracic spine are independent risk factors for the occurrence of large pleural effusion after separation surgery. The combined prediction of the two factors has better predictive efficacy.

Objective:To investigate the surgical method and clinical effect of O-arm navigation mini-open burring for osteoid osteoma.Methods:Eighteen patients with osteoid osteoma were treated with O-arm guided grinding drill from June 2021 to May 2022, including 15 males and 3 females, the age was (18.4 ±10.9) years (range 2 to 44 years), and the course of disease ranged from 1 week to 3 years (mean 14.2 months). The lesions sites included 6 cases of proximal femur, 3 cases of distal femur, 4 cases of proximal tibia, 1 case of distal tibia, 2 cases of proximal fibula and 1 case of distal and proximal humerus. During the operation, the O-arm navigation was used to determine the location of the focus, the muscle and soft tissue was peeled off to the bone surface through a 1-4 cm small incision, the channel retractor was placed, and the burr was registered as a navigation recognition device to gradually remove the bone on the surface of the tumor nest, and the tumor nest was scraped with a curette for pathological examination; according to the navigation image, the focus was enlarged removed with burr and the grinding range was confirmed by the O-arm X-ray machine before the end of the operation. The patients were followed up for 6 to 15 months (mean 9.5 months). CT scans were performed before and after surgery for imaging comparison in order to figure out whether it had residual lesions or recurrence. The visual analogue score (VAS) of pain was used as a parameter for evaluating the clinical efficacy.Results:The operation time of 18 cases was 40-175 min, with an average of 89.3 min. The time required to establish navigation image was 18.0 ±4.1 min (range 13 ~ 22 min). The length of the incision was 2.7±1.1 cm (range 1-4 cm). All patients achieved complete curettage of the lesions, and osteoid osteoma was confirmed by pathology after operation. All the patients could move to the ground 24 hours after operation, and the pain was significantly relieved from 3 to 7 d after operation, and the pain almost disappeared 3 months after operation. The VAS score of 18 cases was 5.33±1.24 before surgery, 2.79±1.32 on the 3rd day, 1.86±1.21 on the 7th day, 0.86±0.93 on the 1st month, 0.33±0.48 on the 3rd month, and 0.09±0.29 on the 6th month after operation, and the difference was statistically significant ( F=58.50, P<0.001). There were no serious complications during and after operation, and the success rate of treatment (no recurrence of symptoms, no residual recurrence of imaging lesions, no serious complications after operation) was 100%. Conclusion:Treatment of osteoid osteoma with mini-open excision using burrs under the navigation of O-arm is a simple, safe, minimally invasive and efficient technique. Intraoperative precise positioning and the use of burr with navigation to remove a larger area than the tumor nest are the keys to successful treatment.

Objective:To explore the risk factors of recurrence after resection of thigh soft tissue malignant tumors and the evaluation of the postoperative lower limb function.Methods:A total of 211 patients who underwent thigh soft tissue malignant tumor resection in the Department of Orthopaedics of the second affiliated Hospital of Medical College of Zhejiang University from May 2011 to May 2021 were retrospectively analyzed, including 117 males and 94 females, aged 53 (43, 65) years. There were 59 cases of atypical/well-differentiated liposarcoma, 30 cases of other types of liposarcoma, 33 cases of malignant fibrous histiocytoma, 19 cases of fibrosarcoma, 12 cases of rhabdomyosarcoma, 12 cases of leiomyosarcoma, 9 cases of synovial sarcoma, and 37 cases of others. The tumor involvement of muscle, bone, blood vessel, nerve tissue and intermuscular compartment, postoperative Musculoskeletal Tumor Society (MSTS) functional score and recurrence were recorded. The relationship between anatomical structure and postoperative recurrence was analyzed by Cox logistic regression to determine risk factors; the cumulative recurrence rate of different compartment groups (medial compartment, anterior compartment, and posterior compartment) were compared; The Box plot was used to compare the postoperative function of patients with resection of different anatomical structures (e.g., vastus lateralis, biceps femoris, femur, etc.).Results:A total of 34 out of 211 patients relapsed, with a recurrence rate of 16.1%. The recurrence time ranged from 2.6 months to 91.6 months after operation, with a median recurrence time of 37.0 (18.2, 52.8) months. Three independent risk factors were found to be associated with recurrence, namely: pathological grade [ HR=3.86, 95% CI(1.75, 8.51)], involvement of vastus intermedius [ HR=3.05, 95% CI(1.53, 6.06)], and involvement of vastus medialis [ HR=3.17, 95% CI(1.56, 6.41)]. The recurrence rate of patients with anterior chamber tumor resection was 35.3%, which was higher than that of patients without tumor resection (16.2%), and the difference was statistically significant ( P=0.020). There was no significant difference in recurrence rate between patients with medial chamber tumor resection and patients without tumor resection ( P>0.05). The recurrence rate of patients with posterior compartment tumor resection was 12.3%, which was lower than that of unresectable patients (37.6%), and the difference was statistically significant ( P=0.002).The postoperative MSTS score of 167 patients averaged 26±3.2 points (9-30 points). After intraoperative resection of part of the femur, vastus intermedius, vastus medialis, and rectus femoris, the patient's function was relatively poor [corresponding median MSTS score: 25 (23, 28), 26 (24 28), 26 (24,28), 26(24, 27)]. Conclusion:The risk factors for local recurrence after resection of thigh soft tissue malignant tumors include: pathological grade of the tumor, and whether the vastus intermedius or vastus medialis is involved. Anterior compartment tumors have a higher recurrence rate after surgery. If the tumor involves the above-mentioned anatomical structures, more attention should be paid to the risk of local recurrence after surgery.

Objective:To explore the clinical characteristics of dislocation after resection and reconstruction of tumors involving pelvic area II, and to try to propose intraoperative and postoperative techniques to prevent its occurrence.Methods:From March 2011 to March 2021, 122 patients with resection and reconstruction involving pelvic area II were retrospectively analyzed. Among them, 17 had postoperative dislocation, 32 had pelvic area II, and 31 had pelvic area I+II. There were 40 cases in the pelvic area II+III, and 19 cases in the pelvic area I+II+III. There were 49 female patients and 73 male patients; the mean age was 47 years (9-73 years). The Musculoskeletal Tumor Society (MSTS) score of lower extremity patients after reduction was evaluated, and the clinical characteristics of dislocation, such as dislocation direction, dislocation time and reduction method, were counted and analyzed, and feasible prevention measures were analyzed based on the imaging characteristics after resection and reconstruction. dislocation method.Results:Among the 122 patients, there were 17 cases of dislocation, and the dislocation rate was 13.7%. Among them, 12 cases were anterior dislocation, accounting for 70.6% of anterior dislocation; 5 cases were posterior dislocation, and the proportion of posterior dislocation was 29.4%, difference (χ 2=4.52, P=0.033). There were 12 cases of dislocation within 3 months after operation, accounting for 70.6%; 1 case of dislocation occurred in 5 months after operation, and the other 4 cases of dislocation occurred for more than one year. The MSTS score of the dislocation patients after reduction was 56.1±15.6% (20%-80%). Combined with postoperative imaging examinations, the feasible methods for preventing dislocation include: The anteversion angle of the acetabular cup can be appropriately reduced (0°-10°); The acetabular cup can be appropriately shifted to the rear of the rotation center; Appropriately reducing the anteversion angle of the femoral neck prosthesis, the combination of the three can reduce the occurrence of femoral-acetabular prosthesis impingement; at the same time, the affected limb is controlled in a neutral position with strict nail shoes after surgery to avoid the occurrence of external rotation. Conclusion:The dislocation after tumor resection and reconstruction in pelvic area II is mostly anterior dislocation. Postoperative CT scan of the pelvis shows that the space between the neck of the femoral stem prosthesis and the lower edge of the acetabulum is small, which is prone to impingement. If the anteversion angle of the acetabular cup is appropriately reduced, the acetabular prosthesis is appropriately displaced posteriorly, and the anteversion angle of the femoral neck is reduced by 5°, the possibility of femoral-acetabular impingement can be reduced, thereby reducing the risk of postoperative dislocation.

The nucleocapsid (N) protein of SARS-CoV-2 has been reported to have a high ability of liquid-liquid phase separation, which enables its incorporation into stress granules (SGs) of host cells. However, whether SG invasion by N protein occurs in the scenario of SARS-CoV-2 infection is unknow, neither do we know its consequence. Here, we used SARS-CoV-2 to infect mammalian cells and observed the incorporation of N protein into SGs, which resulted in markedly impaired self-disassembly but stimulated cell cellular clearance of SGs. NMR experiments further showed that N protein binds to the SG-related amyloid proteins via non-specific transient interactions, which not only expedites the phase transition of these proteins to aberrant amyloid aggregation in vitro, but also promotes the aggregation of FUS with ALS-associated P525L mutation in cells. In addition, we found that ACE2 is not necessary for the infection of SARS-CoV-2 to mammalian cells. Our work indicates that SARS-CoV-2 infection can impair the disassembly of host SGs and promote the aggregation of SG-related amyloid proteins, which may lead to an increased risk of neurodegeneration.
Amyloidogenic Proteins/metabolism* ; Amyotrophic Lateral Sclerosis/genetics* ; Animals ; COVID-19 ; Cytoplasmic Granules/metabolism* ; Mammals ; SARS-CoV-2 ; Stress Granules

Objective:To analyze the surgical techniques, surgical indications and early clinical effects of 3D printed hemipelvic prostheses in the reconstruction of pelvic malignant tumors resected by the sacroiliac joint.Methods:From January 2016 to March 2020, a retrospective analysis of 9 patients with malignant tumors involving pelvis I+II or I+II+III region were treated with sacroiliac joint osteotomy and 3D printed pelvic prosthesis reconstruction. There were 7 males and 2 females; their age was 51.1±10.5 years (range 27-66 years). Among them, 5 cases were chondrosarcoma, 1 case was pleomorphic undifferentiated sarcoma, 2 cases were metastatic renal cell carcinoma, and 1 case was metastatic primitive neuroectodermal tumor. Resection of pelvic area I+II or I+II+III were according to the extent of tumor involvement. During the resection of pelvic I region, osteotomy was done through sacroiliac joint surface, and 3D printed hemipelvic prosthesis that fits the sacral auricular surface was used for reconstruction. Postoperative imaging examination was used to evaluate the acetabular rotation center deviation of the pelvic prosthesis; the International Bone Tumor Society (Musculoskeletal Tumor Society, MSTS) function score was used for functional evaluation; the patient's oncology outcome and postoperative complications were evaluated.Results:All 9 patients successfully completed the operation. The operation time was 3.5-6 hours, with an average of 4.5 hours. The intraoperative blood loss was 800-3 000 ml, with an average of 1 400 ml. 3 patients underwent resection and reconstruction of pelvis I+II area, 4 patients underwent pelvic resection and reconstruction of I+II+III area, 2 patients underwent pelvic I+II+III area combined with proximal femur resection and reconstruction; all patients were followed up. The follow-up time was 6-50 months, with an average of 16 months. At the last follow-up of 9 patients, the MSTS score was 12-26, with an average of 20.2; the postoperative rotation center horizontal displacement distance was 10.67±7.12 mm, and the vertical displacement was 8.56±4.22 mm. One case of metastatic cancer was found to have multiple metastases throughout the body during chemotherapy 3 months after surgery, and died in 7 months after surgery; 1 case of pelvic metastatic renal cell carcinoma developed multiple metastases within one and a half years after surgery, controlled by targeted drugs, and survived with the tumor; the rest seven cases had no recurrence at the surgical site and no distant metastasis was found.Conclusion:The semipelvic prosthesis with 3D printed auricular surface has potential advantages in reconstructing the bone defect of the pelvis I+II or I+II+III area after the sacroiliac joint osteotomy. The short-term efficacy is relatively satisfactory, and the long-term efficacy remains to be further observed.

The transportation of electron is inseparable from vacuum environment. The maintenance of the vacuum system of Elekta linear accelerator depends on two sputtering ionic pumps at the gun end and the target end. The traveling wave acceleration were used in Elekta linear accelerators. And the design of the electron gun filament is detachable. Because of these two reasons, the vacuum stability is relatively weak. Only two vacuum values are used to reflect the operation state of the whole vacuum system, which causes a few failures but will not trigger a the machine interlock. Considering the complexity of whole vacuum system, the problem of vacuum caused by the failure of various components in vacuum system is analyzed in this paper. It is hoped that some useful repairing experience and suggestions for the maintenance engineers of linear accelerator to solve the vacuum fault and rebuild the vacuum can be provided quickly.
Electrons ; Particle Accelerators ; Radiotherapy Dosage ; Vacuum

Objective: To study dose-response relationships of fractionated irradiation induced pulmonary fibrosis in mice according to radiological imaging changes of lung. Methods: A total of 8-10 week old-female C57BL6 mice were randomized into different groups for whole thoracic irradiation. The prescribed doses were 0, 2.0, 4.0, 6.0, 7.0, 8.5 Gy per fraction in a total of 5 fractions. CT imaging was performed at 24 weeks post irradiation. The averaged lung density and volume changes were obtained by the three-dimensional segmentation algorithm, and further analyzed in Boltzmann regression modeling. Results: At the endpoint of 24 weeks, the dose-dependent pulmonary radiological alternations were revealed by coronal view of CT images. Translational analysis of fibrosis-related gene-signatures as well as histological collagen stainings further corroborated the radiological findings. According to Boltzmann modeling, the E₅₀ of radiation-induced lung density changes was found to be (30.80±0.80)Gy (adjusted R²=0.97); whereas the E₅₀ for radiation-induced lung volume reduction was determined as (31.31±7.07)Gy (adjusted R²=0.92). Both outcomes indicated a remarkable enhancement of tolerance to normal lung tissues after exposure with 5-fraction versus single fraction scheme. Conclusions The radiation-induced lung density and volume changes depend not only on total dose, but also the number and dose of fractions.

Objective To investigate the safety and efficacy of curettage and excision for giant cell tumor of the cervical spine.Methods Retrospectively analyzed 6 cases of giant cell tumors patients who underwent surgical resection of cervical spine between April 2006 and July 2015.There were 2 males and 4 females with an average age of 31.3 years old (ranged from 18 to 42 years).Among them,4 cases were located in C2 vertebral body,1 case located in C3 vertebral body,1 case in C4 spinous pro cess and vertebral lamina.In this study,all the 6 patients underwent intralesional surgery,3 patients were Enneking grade ⅡA,which 1 case underwent curettage,2 cases underwent extended curettage;three cases were Enneking grade ⅢB,which 1 case underwent extended curettage,and 2 cases underwent subtotal spondylectomy.Three patients received local inactivation of the lesion.One patient received local radiotherapy after first posterior occipital-cervical fixation,and underwent posterior and anterior tumor resection,bone grafting and internal fixation 3 months later.One patient was treated with denosumab preoperatively,3 patients were treated with bisphosphonates postoperatively.The neurological status was evaluated by Frankel classification pre-and postoperatively,the pain scale was evaluated by Visual Analogue Scale (VAS) pre-and postoperatively.Imaging examination was used to assess the location and the extent of the tumor preoperatively,as well as the tumor recurrence postoperatively.Results The mean follow-up period was 61.1 months (ranged from 25 to 134 months).One case underwent posterior surgery,while other 5 cases underwent anterior and posterior surgery;3 patients underwent one-stage surgery,3 patients underwent multi-staged surgery.The mean intraoperative bleeding was 2 142 ml (ranged from 300 to 9100 ml).The mean preoperative VAS score was 3 (ranged from 2 to 5),the neck pain of the patients were all relieved postoperatively,and the mean VAS score was 0.The Frankel grade were E in all 6 patients of pre-and postoperation.One intracranial epidural hematoma occurred on the second day after operation,emergency evacuation of hematoma was then performed and the postoperative recovery was good.At the latest follow-up,no internal fixation loosening or failure occurred,and no tumor recurrence was observed in all patients.Conclusion Intralesional curettage and excision of the cervical spinal giant cell tumor is a safe and effective surgical method which can achieve satisfactory local control and prognosis.