BACKGROUND:There is still no consensus on the optimal internal fixation for the treatment of Pauwels Ⅲ femoral neck fracture,and most of the related finite element analyses have been performed using a single simplified loading condition,and the biomechanical properties of commonly used internal fixation devices need to be further investigated. OBJECTIVE:To analyze the biomechanical characteristics of Pauwels Ⅲ femoral neck fractures treated with cannulated compression screw,dynamic hip screw,and femoral neck system by finite element method under different loading conditions of single-leg standing loads and sideways fall loads. METHODS:The DICOM data of healthy adult femur were obtained by CT scanning,imported into Mimics 15.0 software to obtain the rough model of bone tissue.The data exported from Mimics were optimized by Geomagics software,and then three internal fixation models were built and assembled with the femur model according to the parameters of the clinical application of the cannulated compression screw,dynamic hip screw,and femoral neck system by using Pro/E software.Finally,the three internal fixation models were imported into Ansys software for loading and calculation to analyze the stress distribution and displacement of the femur and the internal fixation under different working conditions of single-leg standing loads and sideways fall loads,as well as the stress characteristics of the calcar femorale and Ward's triangle. RESULTS AND CONCLUSION:(1)Under the single-leg standing load and the sideways fall load,the proximal femoral stress of the three internal fixation models was mainly distributed above the fracture end of the femoral neck.The peak stress of the proximal femoral end,fracture end,Ward triangle,and calcar femorale of the three internal fixation models were the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(2)Under the single-leg standing load and the sideways fall load,the peak displacement of the proximal femur of the three internal fixation models was all located at the top of the femoral head,and the peak displacement was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(3)The peak displacement of the three internal fixation models was all located at the top of the internal fixation device under the single-leg standing and sideways fall loading conditions,and the peak displacement values were the smallest in the femoral neck system internal fixation model and the largest in the cannulated compression screw internal fixation model.(4)The internal fixation stress of the three internal fixation models was mainly distributed in the area near the fracture end of the internal fixation device under the single-leg standing and sideways fall loads,and the peak value of internal fixation stress was the smallest in the femoral neck system model and the largest in the cannulated compression screw model.(5)These results suggest that the mechanical stability of the femoral neck system is the best,but there may be a risk of stress shielding of the fracture end and calcar femorale.The stress of the internal fixation device of the femoral neck system is more dispersed,and the risk of internal fixation break is lower.

Objective To investigate the impact of statistical uncertainty per control point(SUpCP)on dose calculation on volumetric modulated arc therapy(VMAT)for rectum cancer,and to analyze the accuracy and efficiency of calculation.Methods 19 patients with rectum cancer undergoing radiotherapy were selected.The initial VMAT plans were generated on Monaco TPS using SUpCP=3,then changed SUpCP in the dose calculation process as follow:10 SUpCPs(1～10)for each patient,and totally190 VMAT dose distributions were obtained.For plan evaluation,Dmax,Dmean,D95%,V50,homogeneity index(HI),conformity index(CI)of the planning target volume(PTV),dissymmetric variations of bladder,small intestine and femoral head,and time calculation(Time)were analyzed.Patient specific quality assurance(PSQA),dose deviation of isocenter(ΔDISO)and passing rate of three-dimensional dose distribution(γ33,γ32,γ22)between calculated and delivered radiation doses were measured.Results AsSUpC increased,Dmax and HI of PTV,Dmax of bladder were increased,but D95%and V50 of PTV,Time,γ32 and γ22 were decreased(P<0.05).Dmax and CI of PTV,Dmean of bladder,Dmax and Dmean of small intestine and femoral head,ΔDISO and γ33 showed no statistical significance(P>0.05).When ΔDISO<1%,gamma passing rate>90%for all VMAT plan.When SUpCP<6,Dmax of PTV<110%of the prescribed dose was obtained;while SUpCP>2,time for dose calculation was less than 5 min.Conclusion For VMAT plan of rectum cancer on Monaco TPS using XVMC algorithm,3%～5%of statistical uncertainty per control point for dose calculation,and 3%2 mm or 2%2 mm gamma criteria for three-dimensional dose verification is recommended.This study provides clinical application basis for precise dose calculation of VMAT plan of rectum cancer.

Background and Aims:Cholangiocarcinoma,a rare malignant tumor,is difficult to diagnose and often detected at an advanced stage,limiting treatment options to palliative care.Conventional chemotherapy drugs have poor efficacy against cholangiocarcinoma,making the search for new treatments critical.This study was conducted to investigate the effects of Huai'erjunzhi on the malignant biological behavior of human cholangiocarcinoma cells and its relationship with the TGF-β/Smad pathway,aiming to provide a theoretical basis for the use of Huai'erjunzhi in cholangiocarcinoma treatment. Methods:Human normal liver cells(L-02)and human cholangiocarcinoma cells(HuCCT1)were incubated with different concentrations of Huai'erjunzhi for various durations.Cell proliferation was assessed,and the half-maximal inhibitory concentration(IC50)was calculated.HuCCT1 cells were divided into a negative control group(no intervention),a positive control group(15 mg/L cisplatin),and different Huai'erjunzhi intervention groups(1/5 IC50,2/5 IC50,and IC50 based on preliminary experimental results).Scratch and Transwell assays were used to measure cell migration and invasion,while Western blot was employed to detect the expression of proteins related to the TGF-β/Smad pathway in HuCCT1 cells. Results:Only high concentrations of Huai'erjunzhi(＞312.5 mg/L)significantly inhibited the proliferation of L-02 cells.Huai'erjunzhi significantly inhibited the proliferation of HuCCT1 cells at concentrations above 5 mg/L in a concentration-dependent manner(all P＜0.05),with IC50 values of 138.52 mg/L at 24 h,99.41 mg/L at 48 h,and 113.52 mg/L at 72 h.Compared with the negative control group,the positive control group and the three Huai'erjunzhi intervention groups(20,40,and 100 mg/L)exhibited reduced migration distance,decreased invasive cell numbers,lower expression of TGF-β1,Smad2,Smad3,Smad4,N-cadherin,Snail,and Slug,and increased expression of E-cadherin(all P＜0.05).Compared with the positive control group,these changes in the Huai'erjunzhi groups were less pronounced but showed a clear concentration-dependent relationship(all P＜0.05). Conclusion:Huai'erjunzhi can potentially inhibit the malignant biological behavior of HuCCT1 cells by inhibiting the TGF-β/Smad pathway.

The theory of Zang Xiang is the core of the theory of traditional Chinese medicine,and its content mostly comes from the comparison of images.Among them,the liver Zang of"main drainage"and"main blood storage"involves many systems such as nerve,digestion,circulation,hematopoiesis,reproduction and so on.It is difficult to find the corresponding anatomical organs or tissues in western medicine.The author analyzes and believes that the collection of the functional system of the liver system of traditional Chinese medicine,compares the physiological function and pathological changes of the liver system with the histamine receptor distributed in multiple systems of the whole body,as well as the main symptoms and adverse reactions of the drugs regulating the histamine receptor,and believes that the functional system composed of histamine receptors may carry the important functions of the liver system of traditional Chinese medicine.

ObjectiveTo observe the regulatory effect of Yuyetang on Ghrelin level in rats with type 2 diabetes mellitus （T2DM）-induced cognitive impairment （DCI） and explore the pathway in the prevention and treatment of DCI. MethodThe T2DM model was induced in rats by intraperitoneal injection of streptozotocin （STZ） combined with the high-fat and high-sugar diet （STZ）. The model rats were divided into model group， metformin group （200 mg·kg^-1）， and low-，medium-， and high-dose Yuyetang groups（4.575，9.15， 18.3 g·kg^-1）according to the blood glucose， with 10 rats in each group. A normal group was also set up. The rats were administered with corresponding drugs by gavage for 30 days， and the body weight and blood glucose of the rats in each group were observed and recorded. After drug intervention， the learning and memory abilities of rats were tested by the Morris water maze. After the test， the whole brains of rats were sampled for hematoxylin-eosin （HE） staining to observe the pathological changes in the hippocampal CA1 region， and the expression of Ghrelin in gastric tissues and hippocampal CA1 region was detected by immunohistochemistry. ResultCompared with the normal group ， the model group showed increased blood glucose（P<0.01），reduced body weight（P<0.01），prolonged escape latency（P<0.05，P<0.01）， shortened retention time and movement distance in the target area，decreased number of platform crossings（P<0.01）， abnormal morphology and structure of cells with disordered arrangement and reduced number in the hippocampal CA1 region， and decreased expression of Ghrelin in the serum，hippocampal CA1 region， and gastric tissues（P<0.05， P<0.01）. Compared with the model group， the medium- and high-dose Yuyetang groups showed increased body weight， while all Yuyetang groups showed reduced blood glucose（P<0.01）， shortened escape latency （P<0.05）， prolonged retention time and movement distance in the target area，increased platform crossings （P<0.05， P<0.01）， improved morphology and structure of cells， increased number of normal cell in the hippocampal CA1 region， and elevated Ghrelin levels in the serum， gastric tissues， and hippocampal CA1 region（P<0.05， P<0.01）. ConclusionYuyetang can effectively improve the cognitive ability of DCI rats， and its mechanism may be related to the regulation of Ghrelin levels in the serum， hippocampal CA1 region， and gastric tissues.

Objective: To explore the effect of miR-3188 on the proliferation, apoptosis, invasion and migration of gastric cancer cells and the underlying molecular mechanism. Methods: The expression level of miR-3188 was examined in normal human gastric mucosal cells(GES-1) and human gastric cancer cell lines(HGC-27,MGC-803,BGC-823,MKN-45) by qRT-PCR. It was determined by bioinformatic analysis and dual luciferase reporter assay whether NRAGE was the target gene of miR-3188.miR-3188 mimic, miR-3188 inhibitor and negative control miR-NC were transfected into gastric cancer cell line HGC-27 respectively, and the expression of NRAGE on protein and mRNA levels was detected by Western blot and qRT-PCR. miR-3188 mimic, NRAGE overexpression plasmid(pc-NRAGE) and its negative control(miR-NC,pc-control) were separately or co-transfected into gastric cancer cell line HGC-27. CCK-8, flow cytometry and Transwell experiment were used to detect cell proliferation, apoptosis, invasion and migration in each group. The expressions of epithelial-mesenchymal transition(EMT), proliferation, apoptosis, invasion and migration related proteins [CyclinD 1,matrix metalloproteinase 9(MMP 9),Bcl-2,N-cadherin, Vimentin, E-cadherin] in each group were detected by Western blot. Results: The expression of miR-3188 in human gastric cancer cell lines was lower than that of human normal gastric mucosal cells. Bioinformatics analysis and dual luciferase reporter assay confirmed that miR-3188 could target and bind to NRAGE 3′UTR.Western blot and qRT-PCR confirmed that miR-3188 negatively regulated the expression of NRAGE on the protein level in HGC-27 cells, but not on the mRNA level. Compared with the miR-NC group, Transfected miR-3188 mimic reduced the proliferation, invasion and migration ability of HGC-27 cells, and increased the apoptosis rate, and the co-transfection of pc-NRAGE could reverse the above effects. Compared with the miR-NC group, when miR-3188 was overexpressed in HGC-27 cell, the expression of cyclinD 1, MMP 9, Bcl-2, N-cadherin, and Vimentin was down regulated, while E-cadherin expression was up-regulated, and the above effects could be reversed by co-transfection with pc-NRAGE. Conclusion The miR-3188/NRAGE axis may play important roles in the progression of gastric cancer, and miR-3188 may be a potential therapeutic target for gastric cancer.

Glycosylation is one of the most important post-translational modification in protein biosynthesis. Immunoglobulin glycosylation can exert anti-inflammatory or pro-inflammatory activity by regulating antibody stability and affecting its interaction with different FcγRs. In recent years, a large number of studies have confirmed that abnormal glycosylation of immunoglobulin plays a key role in the pathogenesis of autoimmune diseases. Its products, such as sugar chain structure or/and glycosylated proteins, can be detected by lectin microarray and other technologies, are expected to become new serum markers of autoimmune diseases. It has a broad application prospect in disease diagnosis, condition monitoring, prognosis evaluation and treatment.

Objective:To assess and compare the performance of limiting-antigen avidity enzyme immunoassay (LAg-Avidity EIA) and pooling PCR in the surveillance for recent infection rates of HIV-1 in men who have sex with men (MSM).Methods:Blood samples were collected from MSM selected through snowball sampling method in sentinel surveillance in 13 prefectures of Yunnan province from 2016 to 2017. The samples were tested for HIV-1 antibody. The confirmed positive samples were tested by LAg-Avidity EIA. The negative samples were tested by pooling PCR. The recent infection rates of HIV-1 were estimated by the algorithm based on LAg-Avidity EIA and pooling PCR respectively. The two results were compared.Results:During 2016-2017, a total of 5 363 blood samples were collected from MSM, in which 407 samples were HIV-1 positive (including 177 positive tested previously) and 4 956 samples were HIV-1 negative. A total of 211 samples(91.7%) were tested by LAg-Avidity EIA, 69 were confirmed to be recent infections. A total of 4 469 samples were tested by pooling PCR, 8 were confirmed to be acute infections. The recent infection rates of HIV-1 from 2016 to 2017 estimated by LAg-Avidity EIA were 3.36% and 4.84%, and the recent infection rates estimated by pooling PCR were 3.27% and 3.02% respectively. The differences in recent infection rates of HIV-1 estimated by the two algorithms were not significant.Conclusions:The recent infection rates of HIV-1 estimated by LAg-Avidity EIA and pooling PCR in sentinel surveillance in MSM in Yunnan had good consistency from 2016 to 2017. Using the two methods might have a better stability in continuous surveillance for recent infection rates of HIV-1.

Objective:To analyze the sensitivity and specificity of SARS-CoV-2 nucleic acid testing in 20 348 close contacts of COVID-19 cases in different prevention and control stages in Guangzhou and to provide scientific evidence for optimizing epidemic response strategies.Methods:A total of 20 348 close contacts of COVID-19 cases in Guangzhou were traced between February 21 and September 22,2020. All the close contacts were tested for the nucleic acid of SARS-CoV-2. The sensitivity and specificity of nucleic acid testing and diagnosis in the different prevention and control stages were compared.Results:In 20 348 close contacts, 12 462 were males (61.24%), the median ( P 25, P 75) of age of them was 31.0 years (23.0,43.0), the median number ( P 25, P 75) of nucleic acid testing for them was 2.0 (1.0,3.0), and the median ( P 25, P 75) of their quarantine days was 12.0 (8.0,13.0) days, respectively. A total of 256 COVID-19 cases were confirmed in the close contacts after seven nucleic acid tests. In the 1 st, 2 nd, 3 rd and 7 th nucleic acid testing, the sensitivity and specificity were 69.14% and 99.99% (177 cases confirmed), 89.84% and 99.99% (230 cases confirmed), 97.27% and 99.99% (249 cases confirmed), and 100.00% and 99.98%, respectively. In the three stages of COVID-19 prevention and control in China: domestic case stage, imported case stage, and imported case associated local epidemic stage, the sensitivity of the 1 st nucleic acid testing was 70.68%, 68.00% and 67.35%, and the specificity was 99.98%, 100.00% and 100.00%, respectively. Conclusions:The sensitivity of nucleic acid testing in the close contacts at the different stages were consistent with slight decrease, which might be related to the increased proportion of asymptomatic infections in the late stage of epidemic prevention and control with COVID-19 in Guangzhou. It is suggested to give three nucleic acid tests to improve the sensitivity and reduce false negative risk.

Objective To compare the clinical efficacy of the flaps of modified Limberg and direct incision followed by suture in the treatment of sacrococcygeal pilonidal sinus,aiming to provide the academic guide for its clinical surgery.Methods A total of 76 patients suffered from sacrococcygeal pilonidal sinus were treated with two surgical methods in Department of General Surgery and Department of Burn and Plastic Surgery in Sixth Medical Center of PLA General Hospital from 2013 to 2017.Among these patients,37 cases were resected and reconstructed using the flaps of modified Limberg,the other 39 cases were sutured after beingresected.These patients were followed up during the next 1 or 2 years.Five indexes including surgery period,length of hospital stay,postoperative infection,recurrence and complication,were investigated to statistically compare two different surgery methods' efficacy,using independent t test or chi-square test respectively.Results There were 76 patients in the Limberg flap group and the direct suture group,the operation time was about one and a half hours,and the hospitalization time was about 15 days (P＞0.05);there was no statistical difference between them.There were no complications in 35 of the 37 patients in the Limberg flap group,but skin cracking and infection in 2 patients.In the direct suture group,there were 39 patients,16without complications and 23 with complications,(x2=1133.2393,P=0.0000);there were statistical differences.Among the 37 patients in the Limberg flap group,only one recurred;among the 39patients in the direct suture group,9 recurred (x2=1192.9211,P=0.0000);there were statistical differences.Conclusions Limberg flap incision shows good healing and fewer complications.Within the group of Limberg flap incision healing,only few cases of recurrences occur after the surgery.It not only effectively reduce the complication rate in patients,but also release the pain from long-term,reduplicated medication.The author proposes that this operation should be promoted in the future clinical practice.