Objective To investigate the creep effect of ultrahigh-molecular-weight polyethylene(UHMWPE)liners on the wear of hip prostheses under different physiological activities.Methods A finite element model of a cobalt-chrome alloy(CoCr)head and UHMWPE liner was established and validated.The effects of the ISO 14242 standard gait and daily activities(standing up/sitting down,climbing stairs,and knee bending)on prosthesis wear and creep were compared and analyzed.Results Under the ISO 14242 standard gait,the maximum contact pressure of the liner decreased from 18.3 MPa to 12.2 MPa when creep was not considered,and from 15.3 MPa to 14.2 MPa when creep was considered.The maximum linear penetration depths owing to wear and creep were 0.47 mm and 0.11 mm,respectively,with a wear volume of 205 mm3.The wear under different physiological activities was ranked as follows:climbing stairs>standing up/sitting down>ISO standard gait>knee flexion.The creep was ranked as follows:ISO standard gait>stair climbing>knee bending>standing up/sitting.Conclusions The wear and creep of the acetabular liner differed significantly under different physiological activities.The maximum contact pressure of the UHMWPE liner was reduced by the creep effect.This,in turn,decreased the wear volume.Both creep and wear should be considered in the design of hip prostheses to optimize their performance and extend their service life.

Objective To investigate the creep effect of ultrahigh-molecular-weight polyethylene(UHMWPE)liners on the wear of hip prostheses under different physiological activities.Methods A finite element model of a cobalt-chrome alloy(CoCr)head and UHMWPE liner was established and validated.The effects of the ISO 14242 standard gait and daily activities(standing up/sitting down,climbing stairs,and knee bending)on prosthesis wear and creep were compared and analyzed.Results Under the ISO 14242 standard gait,the maximum contact pressure of the liner decreased from 18.3 MPa to 12.2 MPa when creep was not considered,and from 15.3 MPa to 14.2 MPa when creep was considered.The maximum linear penetration depths owing to wear and creep were 0.47 mm and 0.11 mm,respectively,with a wear volume of 205 mm3.The wear under different physiological activities was ranked as follows:climbing stairs>standing up/sitting down>ISO standard gait>knee flexion.The creep was ranked as follows:ISO standard gait>stair climbing>knee bending>standing up/sitting.Conclusions The wear and creep of the acetabular liner differed significantly under different physiological activities.The maximum contact pressure of the UHMWPE liner was reduced by the creep effect.This,in turn,decreased the wear volume.Both creep and wear should be considered in the design of hip prostheses to optimize their performance and extend their service life.

Objective:To investigate the surgical indications of gallbladder polyps.Methods:The retrospective case-control study was conducted. The clinicopathological data of 2 272 patients with gallbladder polyps who underwent cholecystectomy in 11 medical centers from January 2015 to December 2019 were collected, including 585 in the First Affiliated Hospital of Xi′an Jiaotong University, 352 in No. 215 Hospital of Shaanxi Nuclear Industry, 332 in the First People′s Hospital of Xianyang, 233 in Shaanxi Provincial People′s Hospital, 152 in the Second Affiliated Hospital of Xi′an Jiaotong University, 138 in Xianyang Hospital of Yan′an University, 137 in People′s Hospital of Baoji, 125 in Hanzhong Central Hospital, 95 in Baoji Central Hospital, 72 in Ankang Central Hospital, 51 in Yulin No.2 Hospital. There were 887 males and 1 385 females, aged (48±12)years, with a range from 12 to 86 years. Observation indicators: (1) surgical treatment, pathological examination and hospitalization; (2) follow-up and complications; (3) comparison of clinicopathological data between patients with non-neoplastic polyps and neoplastic polyps; (4) comparison of clinicopathological data among patients who had gallbladder polyp diameter of 7 to 9 mm, 10 to 12 mm, or ≥13 mm without cholecystolithiasis; (5) analysis of influence factors for the incidence of neoplastic polyps in patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis; (6) construction and evaluation of nomogram prediction model for neoplastic polyps of patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis. Follow-up using outpatient examination or telephone interview was conducted to detect complications and survival of patients up to April 2020. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M (range), and comparison between groups was analyzed using the rank-sum test. Ordinal data was analyzed using the rank-sum test of multi-samples. Analysis of influence factors for the incidence of neoplastic polyps was conducted after excluding missing data of CEA and CA19-9. Univariate analysis was conducted using the chi-square test or rank-sum test of multi-samples, and multivariate analysis was conducted using Logistic regression model. Based on Logistic regression model multivariate analysis, the nomogram prediction model was constructed using the R 3.6.0 version software. Results:(1) Surgical treatment, pathological examination and hospitalization: of the 2 272 patients, 2 199 cases underwent laparoscopic cholecystectomy, 43 cases underwent open cholecystectomy, 28 cases underwent radical resection for gallbladder carcinoma, and 2 cases underwent laparoscopic gallbladder preservation and polypectomy. There were 1 050 of the 2 272 patients undergoing intraoperative frozen section examination. Results of pathological examination showed that 1 953 of the 2 272 patients had non-neoplastic polyps including 1 681 cases with cholesterol polyps and 272 cases with inflammatory polyps; 319 cases had neoplastic polyps including 274 with benign polyps (93 cases with adenoma, 66 cases with adenomyoma, 81 cases with adenoma-like hyperplasia, 34 cases with adenoma combined with intraepithelial neoplasia); and 45 cases had malignant polyps including 43 cases with adenocarcinoma, 1 case with adenosquamous carcinoma and 1 case with sarcomatoid carcinoma. The duration of postoperative hospital stay of 2 272 patients was 3 days(range, 1 to 27 days). (2) Follow-up and complications: of the 2 272 patients, 1 932 were followed up for 3.5 to 63.5 months, with a median follow-up time of 31.0 months. During the follow-up, 180 patients had short-term complications and 170 patients had long-term complications. (3) Comparison of clinicopathological data between patients with non-neoplastic polyps and neoplastic polyps: cases with age ≤50 years or >50 years, cases with time from first discovery of polyp to operation <1 year, 1-3 years, >3 years and ≤5 years or >5 years, CEA, CA19-9, CA125, cases with single or multiple polyps in preoperative ultrasonography examination, cases with diameter of polyps in preoperative ultrasonography examination as 1-6 mm, 7-9 mm, 10-12 mm or ≥13 mm, cases with pedicled or broad based polyp wall in preoperative ultrasonography examination, cases with polyp morphology in preoperative ultrasono-graphy examination as nodular, papillary, globular or mulberry-like, cases undergoing or not undergoing intraoperative frozen section examination, cases with diameter of polyps in postoperative pathological examination as 1-6 mm, 7-9 mm, 10-12 mm or ≥13 mm, cases with gallbladder wall thickness in postoperative pathological examination as ≤4 mm or >4 mm of the 1 953 patients with non-neoplastic polyps were 1 118, 835, 1 027, 422, 230, 274, 2.0 mg/L(range, 0.2-8.6 mg/L), 14.5 U/mL(range, 2.6-116.4 U/mL), 10.5 U/mL(range, 1.2-58.7 U/mL), 658, 1 295, 674, 741, 413, 125, 1 389, 564, 407, 1 119, 292, 135, 832, 1 121, 698, 774, 385, 96, 1 719, 234, respectively. The above indicators of the 319 patients with neoplastic polyps were 160, 159, 204, 55, 26, 34, 2.9 mg/L(range, 0.2-28.8 mg/L), 19.7 U/mL(range, 3.5-437.1 U/mL), 15.0 U/mL(range, 1.0-945.0 U/mL), 203, 116, 49, 59, 100, 111, 154, 165, 92, 153, 49, 25, 218, 101, 53, 85, 90, 91, 263, 56, respectively. There were significant differences in the above indicators between the non-neoplastic polyps and neoplastic polyps patients ( χ2=5.599, Z=-3.668, -2.407, -3.023, -3.403, χ2=104.474, Z=-13.367, χ2=65.676, 12.622, 73.075, Z=-11.874, χ2=7.649, P<0.05). (4) Comparison of clinicopathological data among patients who had gallbladder polyp diameter of 7 to 9 mm, 10 to 12 mm, or ≥13 mm without cholecystolithiasis: after excluding 311 of the 2 272 patients with cholecystolithiasis, there were 706 cases with gallbladder polyp diameter of 7 to 9 mm, 459 cases with gallbladder polyp diameter of 10 to 12 mm, and 205 cases with gallbladder polyp diameter ≥13 mm, respectively. Cases with time from first discovery of polyp to operation <1 year, 1-3 years, >3 years and ≤5 years or >5 years, CEA, CA19-9, cases with single or multiple polyps in preoperative ultrasonography examination, cases with pedicled or broad based polyp wall in preoperative ultrasonography examination, cases with polyp morphology in preoperative ultrasonography examination as nodular, papillary, globular or mulberry-like, cases with echo intensity of preoperative ultrasonography examination as slightly strong, medium or weak, cases undergoing or not undergoing intraoperative frozen section examination, and cases with pathological types of polyps as non-neoplastic polyps, benign polyps or malignant polyps of the 706 patients with gallbladder polyp diameter of 7 to 9 mm were 291, 170, 107, 138, 2.2 mg/L(range, 0.5-8.6 mg/L), 21.0 U/mL(range, 2.8-116.4 U/mL), 207, 499, 620, 86, 118, 463, 75, 50, 252, 410, 44, 379, 327, 657, 49, 0, respectively. The above indicators of the 459 patients with gallbladder polyp diameter of 10 to 12 mm were 267, 85, 43, 64, 1.6 mg/L(range, 0.4-9.3 mg/L), 10.4 U/mL(range, 3.3-354.0 U/mL), 205, 254, 237, 222, 158, 223, 51, 27, 222, 213, 24, 263, 196, 373, 79, 7, respectively. The above indicators of the 205 patients with gallbladder polyp diameter ≥13 mm were 128, 38, 20, 19, 2.1 mg/L(range, 0.6-28.8 mg/L), 10.2 U/mL(range, 3.6-307.0 U/mL), 120, 85, 75, 130, 68, 97, 22, 18, 98, 95, 12, 148, 57, 113, 71, 21, respectively. There were significant differences in the above indicators among patients who had gallbladder polyp diameter of 7 to 9 mm, 10 to 12 mm, or ≥ 13 mm ( χ2=46.482, 8.093, 39.504, 66.971, 277.043, 60.945, 19.672, 22.340, 197.854, P<0.05). (5) Analysis of influence factors for the incidence of neoplastic polyps in patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis: of the 459 patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis, there were 373 cases with non-neoplastic polyps, and 86 cases with neoplastic polyps, respectively. Results of univariate analysis showed that CEA, CA19-9, the number of polyps in preoperative ultrasonography examination, diameter of polyps in preoperative ultrasonography examination, polyp wall in preoperative ultrasonography examination were influence factors for the incidence of neoplastic polyps in patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis ( χ2=10.342, 5.616, 20.009, Z=-4.352, χ2=6.203, P<0.05). Results of multivariate analysis showed that CEA>5.0 mg/L, CA19-9>39.0 U/mL, single polyp in preoperative ultrasonography examination, polyp diameter of 11 mm in preoperative ultrasonography examination, polyps of broad base in preoperative ultrasonography examination were independent risk factors for the incidence of neoplastic polyps in patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis ( odds ratio=8.423, 0.082, 0.337, 3.694, 2.318, 95% confidence interval: 1.547-45.843, 0.015-0.443, 0.198-0.575, 1.987-6.866, 1.372-3.916, P<0.05). (6) Construction and evaluation of nomogram prediction model for neoplastic polyps of patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis: CEA, CA19-9, the number of polyps in preoperative ultrasonography examination, diameter of polyps in preoperative ultrasonography examination, polyp wall in preoperative ultrasonography examination were imported into R 3.6.0 version software to establish the nomogram prediction model for neoplastic polyps. The results showed the score for CEA>5.0 mg/L, CA19-9>39.0 U/mL, cases with single polyp in preoperative ultrasonography examination, cases with polyp diameter of 10 mm in preoperative ultrasonography examination, cases with polyp diameter of 11 mm in preoperative ultrasonography examination, cases with polyp diameter of 12 mm in preoperative ultrasonography examination, polyps of broad base in preoperative ultrasonography examination were 25, 27, 100, 0, 26, 72, 98 in the nomogram prediction model, respectively. The C-index of nomogram prediction model was 0.768. Result of nomogram prediction model showed that the incidence of tumor polyps was 0, 6% and 10% in patients with multiple and pedicled gallbladder polyps with diameter of 10, 11, 12 mm and with CEA ≤5.0 mg/L and CA19-9 ≤39.0 U/mL, the incidence of tumor polyps was 43%, 53% and 70% in patients with single and broad base gallbladder polyps with diameter of 10, 11, 12 mm. The calibration curve showed that the probability of the nomogram prediction model predicting neoplastic polyps was nearly consistent with the actual probability. Conclusions:CEA>5.0 mg/L, CA19-9>39.0 U/mL, single polyp in preoperative ultrasonography examination, polyp diameter of 11 mm in preoperative ultrasonography examination, polyps of broad base in preoperative ultrasonography examination are independent risk factors for the incidence of neoplastic polyps in patients who had gallbladder polyp diameter of 10 to 12 mm without cholecystolithiasis. Cholecystectomy should be performed in time for patients with single and broad based gallbladder polyps with diameter of 10, 11, 12 mm.

Objective? To investigate the status of cancer-induced fatigue in patients with primary liver cancer (PLC) and its influencing factors. Methods? A total of 149 postoperative PLC patients undergoing surgical treatment during October 2015 to September 2017 in the Second Affiliated Hospital of Harbin Medical University were recruited by convenience sampling method. The general data questionnaire, Cancer-Related Fatigue Scale (CFS) and Social Support Rating Scale (SSRS) were used to investigate the patients. A total of 149 questionnaires were sent out and 120 valid questionnaires were collected. Results? The CFS score of the 120 postoperative PLC patients was (48.13±5.33). The difference in CFS scores of PLC patients with different education level, monthly income, medical expenses payment, duration of the disease, cognition of disease, chemotherapy and social support was statistically significant (P＜0.05). Multivariate linear regression analysis showed that the influencing factors of cancer-related fatigue in patients with PLC were medical expenses payment, duration of disease, cognition of disease, adjuvant chemotherapy and social support (P＜ 0.05). Conclusions? Cancer-related fatigue is a common problem in PLC patients and is affected by many factors. Clinicians need to combine with the actual situation of patients to develop more targeted individualized programs to alleviate the patient fatigue, improve patient social support, and further improve the quality of life of patients.

Objective To study the effect of pioglitazone,a member of the thiazolidinedione (TZD) class with hypoglycemic action to treat diabetes,on expression of p38 mitogen-activated protein kinase in myocardium of rats following I/R injury.Methods Twenty-four healthy SD rats were randomly divided into sham group,I/R injury group,pioglitazone treatment group and pioglitazone+peroxisome proliferator-activated receptors-γ specific antagonist GW9662 treatment group (6 in each group).A rat I/R injury model was established by ligating the left anterior descending coronary artery.Apoptosis of myocardial cells was assayed by Terminal dUTP deoxynucleotidyl transferase nick end labeling.Expression of p-p38 protein was detected by Western blot.Results The apoptosis index of myocardial cells was significantly lower in sham operation group and piogl itazone treatment group than in I/R injury group and was significantly higher in pioglitazone+ GW9662 treatment group than in pioglitazone treatment group (8.6％±4.3％,21.4％±8.8％ vs 40.1％±12.3％,P＜0.05;37.0％-10.5％ vs 21.4％±8.8％,P＜0.05).The expression level of p-p38 was significantly lower in sham operation group and pioglitazone treatment group than in I/R injury group and was significantly higher in pioglitazone+GW9662 treatment group than in pioglitazone treatment group (P＜0.05).Conclusion Pioglitazone can inhibit I/R injury-induced apoptosis of myocardial cells by downregulating the expression of p-p38 protein.

Objective To explore the early predictive factors of intestinal necrosis in patients with acute superior mesenteric arterial occlusive disease and its significance for the decision of exploratory laparotomy.Methods This retrospective study enrolled 29 patients diagnosed with acute superior mesenteric artery embolism or thrombosis in Peking University People's Hospital between July 1995 and June 2015.Results 12 patients developed intestinal necrosis.Patients with intestinal necrosis had a poorer prognosis than those who did not develop intestinal necrosis (x2 =14.867,P =0.000).In univariate analysis,the early predictive factors for intestinal necrosis were D-Dimer ≥ 600 μg/L (x2 =11.455,P =0.002),INR≥1.2 (x2 =3.948,P =0.047),pH values ＜7.4 (x2 =8.191,P =0.004),BE ＜ -1.0 mmol/L (x2 =8.191,P =0.004),blood lactate ≥ 2.2 mmol/L(x2 =7.535,P =0.006),BUN ≥ 6 mmol/L (x2 =10.076,P =0.002),CK ≥ 80 U/L (x2 =8.191,P =0.004),LDH ≥ 210 U/L (x2 =13.079,P=0.000),AST ≥25 U/L (x2 =10.076,P =0.002),SIRS (x2 =10.076,P =0.002).Multivariate logistic regression analysis found no independent predictive factors of intestinal necrosis in patients with acute superior mesenteric arterial occlusive diseases.Conclusion Intestinal necrosis in acute mesenteric arterial occlusive diseases indicates a poor prognosis.Coagulation abnormalities,liver or kidney dysfunction,metabolic acidosis and SIRS necessitates an immediate exploration.

Objective To explore the difference between T cells in the synovial fluid and peripheral blood in patients with rheumatoid arthritis(RA). Method Samples from 22 patients were studied. The differentiation and activation markers expressed on T cell surface were detected by immunofluorscence using flow cytometer. The specific proliferation of collagen Ⅱ and heat shock protein 70 was analyzed using standard 3H-TdR incorporation method. Restricted V beta usage of these T cell was analyzed by semi-quantitied RT-PCR. Results The majority of the T cell subsets in the synovial fluid were demonstrated to be CD4 and CD8 positive cells in which (40?10)% were CD4 positive and (36?16)% were CD8 T cells respectively. The ratio between CD4 and CD8 was much lower than that found in the PBL of RA patients. The percentage of CD3+/CD25+ T cells was (16?6)%. The specific proliferation of collagen Ⅱ and HSP70 to CD3+/CD25+ T cell was higher than that of CD3+/CD25+ negative T cells. The T cell receptor expressed on the T cells from both peripheral blood and synovial fluid were tested for ?? TCR (70?26)%. However, the T cells in the synovial fluid showed V?14,16 and 17 restriction. Conclusion The data here reported indicates that T cell subsets in the synovial fluid and peripheral blood circulation in patients with rheumatoid arthritis are different. The T cells in the synovial fluid demonstrates more activation and higher reactivation to collagen Ⅱ and HSP70. The TCR of T cells showes V?14,16 and 17 restriction.