Objective:To design an improved lamina hook system and compare its biomechanical properties with traditional lamina hook system in fixation of lumbar spondylolysis.Methods:The thin layer CT data of the lumbosacral vertebrae of 20 healthy young male servicemen who underwent physical examination in the outpatient department of the 940th Hospital of Joint Logistics Support Force of PLA from January 2021 to August 2022 were collected. The age of the subjects was 20-30 years [(25.0±3.0)years]. A 3-dimensional model of the L 5 vertebral body was constructed using the 3-dimensional modeling software. The new improved lamina hook was designed according to the measurements including the thickness of the middle area, the longest longitudinal diameter, the curvature radius of the lower edge, the angle between the upper and lower tail ends, the thickness of the lower edge, and the longest diameter of the lower edge of the bilateral L 5 vertebral plates. One serviceman was selected from the aforementioned group to construct a linear finite element model of segments L 4-S using the 3-dimensional virtual software (normal model, model A), based on which, the L 5 bilateral spondylolysis model (model B), improved lamina hook model (model C) and traditional lamina hook models (model D) were designed. By constraining both sides of the sacrum and applying a longitudinal load of 400 N on the L 4 vertebral body, the upper 1/3 gravity of the body was simulated, and with a bending moment of 10 N·m along the X, Y, and Z directions, motions of forward flexion, backward extension, lateral bending, rotation, etc were simulated. The range of motion of segment L 4/5 and L 5/S 1 of model A was evaluated and compared with the findings of the previous researches to verify its effectiveness. The overall range of motion of models A, B, C, and D, the range of motion of segment L 4/5 and L 5/S 1, the maximum overall displacement, the maximum displacement and stress of the isthmus, the stress distribution and maximum stress of internal fixation of models C and D, and the stress distribution and maximum stress of the vertebral body of models C and D were compared. Results:(1) During forward flexion, backward extension, lateral bending and rotation, the range of motion of model A was 5.01°, 4.03°, 3.91° and 1.42° in segment L 4/5, and was 4.62°, 2.51°, 2.40° and 1.23° in segment L 5/S 1. (2) The overall range of motion, range of motion of segment L 4/5 and L 5/S 1 and maximum overall displacement of models A, C, and D were similar in axial compression, forward flexion, backward extension, left bending, and left rotation, while those of model B were significantly increased. (3) There was no significant difference in the maximum displacement of the isthmus of models A, C, and D under different motion modes, while the maximum displacement of model B in the isthmus was significantly larger than that of models A, C, and D, especially during rotation, increased by 295%, 277%, and 276% respectively. The maximum stress of the isthmus of model C was 0.938 MPa, 1.698 MPa, 0.410 MPa, 2.775 MPa, and 1.554 MPa respectively. The maximum stress in the isthmus of model D was 0.590 MPa, 1.297 MPa, 0.520 MPa, 3.088 MPa, and 2.072 MPa respectively. The maximum stress of the isthmus of models C and D was similar during axial compression and forward flexion, while the stress of the isthmus of model C was smaller than that of model D during backward extension, lateral bending, and rotation, decreased by 21.1%, 10.2%, and 25.0% respectively compared with model D. (4) The maximum stress of internal fixation in models C and D during forward flexion, backward extension, left bending, and left rotation was 135.220 MPa, 130.180 MPa, 200.940 MPa and 306.340 MPa respectively, and was 131.840 MPa, 112.280 MPa, 349.980 MPa and 370.140 MPa respectively. The maximum stress of internal fixation in the two models of internal fixation during forward flexion and backward extension was similar, while it was decreased by 42.6% and 17.2% in model C during left bending and left rotation, compared with model D. (5) The maximum stress of the vertebral body during forward flexion, backward extension, left bending, and left rotation was 79.787 MPa, 36.857 MPa, 37.943 MPa and 96.965 MPa respectively in model C, but was 80.104 MPa, 64.236 MPa, 196.010 MPa and 193.020 MPa respectively in model D. The maximum stress of models C and D was all distributed in the contact area with the internal fixation, and especially during backward extension, left bending, and left rotation, when it was reduced by 42.6%, 80.6%, and 49.8% of model C respectively, compared with that of model D. Conclusions:The improved laminar hook is more consistent with the Chinese anatomized structure of the lamina. Compared with the traditional lamina hook system, the improved lamina hook system can effectively reduce the displacement in all directions and range of motion of lumbar spondylolysis, therefor can significantly reduce the stress of internal fixation and vertebral body and has better biomechanical performance.

In this paper, the domestic and international demand and development trend of clinical diagnostic radionuclides are analyzed, and the medium and high-energy cyclotrons, adequate and systematic facilities, and preparation techniques required for the production of medical radionuclides based on solid targets are introduced. This paper focuses on the research and development carried out by some important medical institutions and scientific research institutes in China over the years in the aspects of medium and high-energy cyclotrons, beam transmission lines, high-power irradiation target stations and new medical isotope production processes etc. It also looks forward to some new directions for the development of medical radionuclides in China during the 14th Five-Year Plan period.

Objective To study the effect of three kinds of commonly used liquid culture media for in vitro cell experiments on elastic modulus of breast cancer cells, so as to provide references for developing novel diagnosis and treatment approach of tumour based on mechanics principles. Methods The elastic modulus and adhesion force of breast cancer cells MCF7 to atomic force microscopy (AFM) probes in phosphate buffered solution(PBS), Dulbecco’s modified eagle media (DMEM) and DMEM+10% fetal bovine serum (FBS) were measured using AFM technology. Results The elastic moduli of breast cancer cells in PBS, DMEM and DMEM+10% FBS were 2.59, 2.11 and 1.59 kPa, respectively. The cell adhesion forces in the above three kinds of liquid medium environment were 63.81, 66.09 and 121.97 pN, respectively. Cell adhesion force in DMEM+10%FBS was significantly different from that of the other two kinds of liquid media. Conclusions There are significant differences in elastic modulus of breast cancer cells in three kinds of liquid media. The difference between DMEM and DMEM+10%FBS might be caused by the different adhesion force caused by serum proteins in the media, and the difference between DMEM and PBS might be attributed to the difference in pH of the media.

Objective:To develop a visualized nomogram with a predictive value to differentiate mass-forming chronic pancreatitis (MFCP) from pancreatic ductal adenocarcinoma (PDAC) patients with chronic pancreatitis (CP) history.Methods:The clinical and radiological data of 5 433 CP patients acoording to the Asia-Pacific Diagnostic Criteria between February 2011 and February 2021 in the First Affiliated Hospital of Naval Medical University were retrospectively analyzed, and 71 PDAC patients with CP history and 67 MFCP who underwent surgery or biopsy and pathologically confirmed were eventually enrolled. The training set included 44 patients with MFCP and 59 patients with PDAC who were diagnosed between February 2011 and April 2018. The validation set consisted of 23 patients with MFCP and 12 patients with PDAC who were diagnosed between May 2018 and February 2021. Univariate and multivariate logistic regression analyses were performed to develop a prediction model for PDAC and MFCP, and the model was visualized as a nomogram. ROC was used to evaluate the predictive efficacy of the nomogram, and the clinical usefulness was judged by decision curve analysis.Results:The univariate analysis showed that a significant association with pancreatic cancer were observed for the duct-to-parenchyma ratio ≥0.34, pancreatic duct cut-off, pancreatic portal hypertension, arterial CT attenuation, portal venous CT attenuation, delayed CT attenuation, and vascular invasion in both the training and validation cohorts, but the duct-penetrating sign in the training cohort only. The multivariable logistic regression analysis showed that statistically significant differences (all P value <0.05) existed in cystic degeneration, a duct-to-parenchyma ratio ≥0.34, the duct-penetrating sign, pancreatic portal hypertension and arterial CT attenuation between the two cohorts. The above parameters were selected for the logistic regression model. The predicted model=3.65-2.59×cystic degeneration+ 1.26×duct-to-parenchyma ratio≥0.34-1.40×duct-penetrating sign+ 1.36×pancreatic portal hypertension-0.05×arterial CT attenuation. Area under the curve, sensitivity, specificity and accuracy of the model-based nomogram were 0.87 (95 CI 0.80-0.94), 89.0%, 75.0% and 83.5% in the training cohort, and 0.94 (95 CI 0.82-0.99), 91.7%, 100% and 97.1% in the validation cohort, respectively. Decision curve analysis showed that when the nomogram differentiated MFCP from PDAC patients with CP history at a rate of 0.05-0.85, the application of the nomogram could benefit the patients. Conclusions:The nomogram based on CT radiological features accurately differentiated MFCP from PDAC patients with CP history and provide reference for guiding the treatment and judging the prognosis.

Objective:To investigate the relationship between the perineural invasion score based on multidetector computed tomography (MDCT) and extrapancreatic perineural invasion (EPNI) in pancreatic ductal adenocarcinoma (PDAC).Methods:The clinical, radiological, and pathological data of 374 patients pathologically diagnosed as pancreatic cancer who underwent radical resection in the First Affiliated Hospital of Naval Medical University from March 2018 to May 2020 were analyzed retrospectively. Patients were divided into EPNI negative group ( n=111) and EPNI positive group (n=263) based on the pathological presence of EPNI. The perineural invasion score was performed for each patient based on radiological images. Univariate and multivariate logistic regression models were used to analyze the association between the perineural invasion score based on MDCT and EPNI in PDAC. Results:There were significant statistical differences between EPNI negative group and positive group on both pathological characteristics (T stage, N stage, invasion of common bile duct, and positive surgical margin) and radiological characteristics (tumor size, vascular invasion, lymph node metastasis, perineural invasion score based on MDCT, pancreatic border, parenchymal atrophy, invasion of duodenum, invasion of spleen and splenic vein and invasion of common bile duct) (all P value <0.05). Univariate analysis revealed that the tumor size, vascular invasion, lymph node metastasis, perineural invasion score based on MDCT, pancreatic border, pancreatic atrophy, invasion of duodenum, invasion of spleen and splenic vein and invasion of common bile duct were independently associated with EPNI. Multivariate analyses revealed that the perineural invasion based on MDCT was an independent risk factor for EPNI in pancreatic cancer (score=1, OR=2.93, 95% CI 1.61-5.32, P<0.001; score=2, OR=5.92, 95% CI 2.68-13.10, P<0.001). Conclusions:The perineural invasion score based on MDCT was an independent risk factor for EPNI in pancreatic cancer and can be used as an evaluation indicator for preoperative prediction of EPNI in PDAC.

Objective:To explore the differential diagnosis of pancreatic acinar cell carcinoma (PACC) and pancreatic ductal adenocarcinoma (PDAC) based on multidetector computed tomography (MDCT) features.Methods:The clinical, pathological and MDCT imaging data of 26 patients with pathologically confirmed PACC and 145 patients with pathologically confirmed PDAC who underwent MDCT from November 2013 to April 2021 were retrospectively studied. The differences of MDCT features including tumor location, tumor size, common pancreatic duct and bile duct dilatation, pancreatitis, lymph node metastasis, cyst, pancreatic parenchyma atrophy, duodenal involvement, bile ductal and vascular involvement between the two groups were compared. Univariate analysis and multivariate analysis by logistic regression models were performed to identify the independent predictive factors for PACC.Results:The tumor size, bile duct dilatation, lymph node metastasis, pancreatic parenchyma atrophy and vascular involvement were significantly different between PACC group and PDAC group (all P value<0.05). Multivariate analysis revealed that the tumor size ( OR=1.07, 95% CI 1.028-1.15, P=0.001), lymph node metastasis ( OR=0.23, 95% CI 0.065-0.800, P=0.02), pancreatic parenchyma atrophy ( OR=0.15, 95% CI 0.048-0.490, P=0.002) were closely associated with PACC. Conclusions:The tumor size, bile duct dilatation, lymph node metastasis, pancreatic parenchyma atrophy and vascular involvement evaluated by MDCT had a certain value in differentiating PACC from PDAC, and the tumor size, lymph node metastasis and pancreatic parenchyma atrophy were independent predictors for the diagnosis of PACC.

Objective: To analyze the molecular characteristics of Listeria monocytogenes strains from ready-to eat food in China. Methods: A total of 239 Listeria monocytogenes strains isolated from ready-to-eat food in 2017, all strains underwent whole-genome sequencing (WGS) , and comparisons uncovered population structure derived from lineages, clonal complex, serogroups, antimicrobial susceptibility and virulence, which were inferred in silico from the WGS data. Core genome multilocus sequence typing was used to subtype isolates. Results: All strains were categorized into three different lineages, lineage Ⅱ was the predominant types in food, and IIa was the main serogroups. CC8, CC101 and CC87 were the first three prevalent CCs among 23 detected CCs, accounting for 49.4%. Only 4.6% (11 isolates) of tested strains harbored antibiotic resistance genes, which were mostly trimethoprim genes (7 isolates, 2.9%). All strains were positive for LIPI-1, and only a part of strains harbored LIPI-3 and LIPI-4, accounting for 13.8% (33 isolates) and 14.2% (34 isolates), respectively. ST619 carried both LIPI-3 and LIPI-4. 51.5% (123 isolates) of strains carried SSI-1, and all CC121 strains harbored SSI-2. Different lineages, serogroups and CCs can be separated obviously through cgMLST analysis, and 24 sublineages were highly concordant with CCs. Conclusion Ⅱa was the main serogroups in ready-to-eat food isolates in China; CC8, CC101 and CC87 were the prevalent CCs, and CC87 isolates was hypervirulent isolates, cgMLST method can be adopted for prospective foodborne disease surveillance and outbreaks detection.

Objective:To investigate the clinical effect of small incision in the sinus tarsal combined with internal fixation with hollow nails or small plates in the treatment of Sanders type II and III calcaneal fractures.Methods:A retrospective analysis of the relevant data of 50 patients with closed calcaneal fractures (sander II, III) were admitted and followed up from September 2015 to April 2017. According to different surgical methods, they were divided into two groups. Those who used a small incision of the sinus tarsal combined with hollow nail or small plate internal fixation were the minimally invasive group; those who used the traditional lateral "L" approach combined with the traditional plate internal fixation were the open group. There were 30 cases in the minimally invasive group, 20 males and 10 females; age 44.53±13.74 years (19 to 78 years); 20 cases in the open group, 13 males and 7 females; age 45.35±12.93 years (19 to 70 years old). The two groups of patients were treated with different methods for surgical treatment. During the operation, the calcaneal varus was corrected and the length, width, and height of the calcaneus were restored, but the fracture end was fixed in different ways. X-ray and CT examinations were performed before and after the operation to evaluate the type of fracture, reduction and fracture healing, the Bohler angle and Gissane angle at the last follow-up were measured, and postoperative complications were recorded. The Maryland foot scoring system was used to evaluate the clinical efficacy.Results:The difference in general information between the two groups of patients was not statistically significant and comparable. Patients in both groups were followed up for 16 months to 36 months, with an average of 21 months. In the minimally invasive group, 7 cases received allogeneic bone grafts, 17 cases were fixed with microplates, and 13 cases were fixed with hollow lag screws; 5 cases in the open group received allogeneic bone grafts, all of which were fixed with conventional lateral calcaneal plates. The intraoperative blood loss during operation in the minimally invasive group was 48.23±5.56 min, the open group was 54.25±5.09 min; the minimally invasive group was 53.10±8.5 ml, and the open group was 61.75±7.13 ml. The differences were statistically significant ( t=3.75 and 3.87, P<0.01). The fracture healing time of the minimally invasive group was 9.6±1.52 weeks, and that of the open group was (11.05±2.33) weeks. The difference between the two groups was statistically significant ( t=2.67, P<0.05). According to the Maryland score at the last follow-up, the excellent and good rate was 80.00% in the minimally invasive group and 50% in the open group. Postoperative imaging showed that the articular surface of the two groups after calcaneal surgery was collapsed and reset, the height, width and length of the calcaneus were restored, and the axis of the calcaneus was corrected. The Gissane angle and Bohler angle were significantly different from those before the operation (both P<0.001) , while Bohler angle in minimally invasive group (15.50°±4.18° vs 31.03°±3.35°, t=15.88), Gissane angle in minimally invasive group (101.87°±9.94° vs 129.17°±4.85°, t=13.52); Bohler angle in open group (15.00°±4.22° vs 30.75°±3.39°, t=13.02), and Gissane angle (104.75°±11.02° vs 128.6°±4.56°, t=8.95). There was no significant difference in the Gissane angle ( t=0.414, P=0.68) and Bohler angle ( t=0.292, P=0.77) between the two groups of patients. In the minimally invasive group, there was 1 case of traumatic arthritis and 1 case of superficial skin border infection, with a complication rate of 6.67%. In the open group, there was 2 cases of skin border necrosis secondary to deep infection, 3 cases of superficial skin border, 2 cases of infection and traumatic arthritis, and the complication rate was 35%. The difference in the overall complication rate between the two groups was statistically significant ( P=0.021). Conclusion:The treatment of calcaneal fractures with sinus tarsal incision plate or hollow screw internal fixation has the advantages of less trauma, reduction under direct vision, reliable reduction and fixation, and low complications. It is suitable for Sanders type II and III calcaneal fractures.

Objective To study the value of reduced field-of-view (rFOV DWI) in differentiating patients with solid pancreatic focal lesions.Methods 139 patients with solid pancreatic mass were enrolled,including 105 patients with pancreatic ductal acinar carcinoma (PDAC),16 patients with neuroendocrine neoplasms,7 patients with mass forming chronic pancreatitis (MFCP) and 11 patients with solid papillary tumor (SPT).38 healthy adult volunteers served as controls,and underwent single stimulated echo planar imaging (ss-EPI) DWI and rFOV DWI(b value =0 and 600 s/mm2) MRI examination.Quartation method was used to evaluate the image quality of ss-EPI) DWI and rFOV DWI in the three terms of the visibility of anatomical structure,contrast of pancreatic lesions,motion and the susceptibility artifacts during MRI.Work station self-carried software was used to measure the ADC value of the region of interest (ROI).The image quality and ADC values of different pancreatic diseases and normal pancreas were compared.ROC curve for ADC value was drawn to evaluate the difference among PDAC,other benign pancreatic masses and normal pancreas.Results At b value of 0 and 600 s/mm2,rFOV DWI was superior to ss-EPI DWI in terms of showing pancreatic anatomic structure,the contrast of the lesion and the score evaluation for susceptibility artifacts(b =0 s/mm22.99 ±0.51 vs 2.79 ±0.64,2.37±0.48 vs 1.81 ±0.63,3.17 ±0.56 vs 2.91 ±0.60;b =600 s/mm23.63 ±0.50 vs 3.32 ±0.56,3.45 ±0.50 vs 3.01 ±0.49,3.74 ±0.44 vs 3.12 ±0.37),and the differences were statistically significant (P＜0.001).ADC values of PDAC,NET,MFCP,SPT and normal pancreas were (1.38 ± 0.17) × 10-3,(1.22 ± 0.35) × 10-3,(1.29 ± 0.13) × 10-3,(1.04 ± 0.38) ×10-3and(1.86±0.15) ×10-3mm2/sforrFOV DWI,and (1.73 ± 0.24) ×10-3,(1.63±0.39) ×10-3,(1.58±0.19) × 10-3,(1.25±0.26) × 10-3 and(2.04±0.20) × 10-3mm2/s for ss-EPI DWI.The difference on ADC values among different groups and within one group were all statistically significant (P ＜0.001).There were no statistical significant differences on ADC values between MFCP and PDAC,between MFCP and SPT as well as on ss-EPI DWI ADC values between PDAC and NET,but statistical differences were found between other two groups (P ＜ 0.05).The area under the ROC curve of rFOV and ssEPI DWI was 0.983 (95％ CI 0.944-0.998) and 0.889 (95％ CI 0.822-0.936),respectively,and the difference was statistically significant (P =0.0004),but rFOV DWI and ss-EPI DWI ADC values for PDAC and all benign solid diseases were 0.799 (95％ CI 0.719-0.864) and 0.755 (95％ CI 0.672-0.827),and the difference was not statistically significant.Conclusions rFOV DWI could significantly enhance the quality of DWI images,and its diagnostic efficacy was much better than ss-EPI DWI.

OBJECTIVETo investigate the epidemiological status of cholestasis in first-hospitalized patients with chronic liver disease in Shanghai, and to provide a scientific basis for developing prevention and treatment measures.

METHODSFrom April 2005 to September 2014, 5,146 first-hospitalized patients in Shanghai with a diagnosis of chronic liver disease were enrolled in this study. Clinical data of the 4,660 patients who fit the study criteria for participation were collected for retrospective analysis.Diagnosis of cholestasis was made according to serum alkaline phosphatase (ALP) levels higher than 1.5 times the upper limit normal (ULN) and gamma-glutamyltransferase (GGT) levels higher than 3 times the ULN. The incidence rate of cholestasis was assessed for relation to age, sex, etiology, and type of liver disease, and statistically compared to the general clinical data and specific biochemical indicators with potential sex-related differences. T-test and chi-square test were performed for the statistical analyses.

RESULTSOf the 4,660 study participants, 10.26% had cholestasis; the prevalence of cholestasis increased with increasing age in male patients. The distribution of the cholestasis incidence according to the type of chronic liver disease was: 75.00%, primary sclerosing cholangitis; 42.86%, primary biliary cirrhosis; 35.97%, hepatic tumor; 30.77%, autoimmune hepatitis; 28.31%, drug-induced liver disease; 16.46%, alcoholic hepatitis; 13.98%, cryptogenic cirrhosis; 12.99%, schistosomal cirrhosis; 7.53%, alcoholic cirrhosis; 7.32%, mixed cirrhosis; 5.94%, viral liver cirrhosis; 2.70%, nonalcoholic fatty liver disease. There was no significant difference in the prevalence of cholestasis between the two sexes. In the patients with cholestasis, the levels of GGT and total bilirubin were significantly different between the two sexes.

CONCLUSIONThe incidence rate of cholestasis in first-hospitalized patients with chronic liver disease was 10.26%, and the rate increased with increased age. Patients with primary sclerosing cholangitis or primary biliary cirrhosis had higher incidence rates of cholestasis. Incidence rates of cholestasis of the various chronic liver diseases were not related to sex.

Bilirubin ; China ; Cholestasis ; Chronic Disease ; Humans ; Incidence ; Liver Diseases ; Male ; Prevalence ; Retrospective Studies ; gamma-Glutamyltransferase