Objective To campare biomechanical effects of different postural compression techniques on three-dimensional model of lumbar disc herniation(LDH)by finite element analysis.Methods Lumbar CT image of a 48-year-old female patient with LDH(heighted 163 cm,weighted 53 kg)was collected.Mimics 20.0,Geomagic Studio,Solidwords and other software were used to establish three-dimensional finite element model of LDH on L4,5 segments.Compression techniques under horizon-tal position,30° forward bending and 10° backward extension were simulated respectively.After applying the pressure,the ef-fects of compression techniques under different positions on stress,strain and displacement of various tissues of intervertebral disc and nerve root were observed.Results L4,5 segment finite element model was successfully established,and the model was validated.When compression manipulation was performed on the horizontal position,30° flexion and 10° extension,the annular stress were 0.732,5.929,1.286 MPa,the nucleus pulposus stress were 0.190,1.527,0.295 MPa,and the annular strain were 0.097,0.922 and 0.424,the strain sizes of nucleus pulposus were 0.153,1.222 and 0.282,respectively.The overall displace-ment distance of intervertebral disc on Y direction were-3.707,-18.990,-4.171 mm,and displacement distance of nerve root on Y direction were+7.836,+5.341,+3.859 mm,respectively.The relative displacement distances of nerve root and interverte-bral disc on Y direction were 11.543,24.331 and 8.030 mm,respectively.Conclusion Compression manipulation could make herniated intervertebral disc produce contraction and retraction trend,by increasing the distance between herniated interverte-bral disc and nerve root,to reduce symptoms of nerve compression,to achieve purpose of treatment for patients with LDH,in which the compression manipulation is more effective when the forward flexion is 30°.

Objective:To evaluate the residual risk (RR) of transfusion transmitted HIV (TT-HIV) after the implementation of nucleic acid amplification test (NAT) in blood screening test among blood centers in China.Methods:The data of blood donors and HIV infection markers from 2017 to 2020 were collected from 28 blood centers via the Platform of Comparison of blood establishments Practice in Chinese Mainland. The new infection rate/window period mathematical model was used for two types of blood screening strategies, namely, two rounds ELISA plus individual NAT take turn with pooling NAT (2ELISA+ ID-NAT/MP-NAT) and two ELISA plus one round pooling NAT (2ELISA+ MP-NAT), and the RR of HIV infection was estimated also based on first donors (FDs) and repeated donors (RDs) in different blood donation years. T-test analyses were conducted for comparing TT HIV RR among FDs and RDs in different blood donation years with two blood screening strategies, and the variation trend of RR in HIV test was observed.Results:From 2017 to 2020, the RR of FDs in 2ELISA+ ID-NAT/MP-NAT blood screening strategy was 2.869/10 6 person-year, 3.795/10 6 persons-year, 3.879/10 6 person-year, and 2.890/10 6 person-year respectively. The RR of RDs was 1.797/10 6 person-year, 1.502/10 6 person-year, 1.857/10 6 person-year, and 1.483/10 6 person-year respectively. Significant difference exists between RR of FDs and RDs, with F=9.898 and p<0.05. In 2ELISA+ MP-NAT strategy, the RR of FDs was 3.508/10 6 person-year, 1.868/10 6 person-year, 2.204/10 6 person-year, and 1.765/10 6 person-year respectively. The RR of RDs was 0.948/10 6 person-year, 0.926/10 6 person-year, 0.748/10 6 person-year, and 0.682/10 6 person-year respectively. Statistical difference existed between RR of FDs and RDs, with F=17.126 and P<0.05. There was no significant difference between the RR of FDs in these two strategies with F=3.493 and P>0.05, while there was a difference between the RR of RDs in these two strategies with F=24.516 and P<0.05, and a difference between the RR of total donors (TDs) in these two strategies F=20.216 and P<0.05. Conclusions:The RR of TT HIV significantly decreased after the introduction of NAT into blood test among blood centers in China. There were some differences in the RR of HIV testing among different blood screening strategies. There could be significant differences in the RR of HIV testing among different groups of blood donors. Compared with FDs, RDs is the low risk group for HIV.

OBJECTIVES: To investigate the incidence of extrauterine growth retardation (EUGR) and its risk factors in very preterm infants (VPIs) during hospitalization in China. METHODS: A prospective multicenter study was performed on the medical data of 2 514 VPIs who were hospitalized in the department of neonatology in 28 hospitals from 7 areas of China between September 2019 and December 2020. According to the presence or absence of EUGR based on the evaluation of body weight at the corrected gestational age of 36 weeks or at discharge, the VPIs were classified to two groups: EUGR group (n=1 189) and non-EUGR (n=1 325). The clinical features were compared between the two groups, and the incidence of EUGR and risk factors for EUGR were examined. RESULTS: The incidence of EUGR was 47.30% (1 189/2 514) evaluated by weight. The multivariate logistic regression analysis showed that higher weight growth velocity after regaining birth weight and higher cumulative calorie intake during the first week of hospitalization were protective factors against EUGR (P<0.05), while small-for-gestational-age birth, prolonged time to the initiation of total enteral feeding, prolonged cumulative fasting time, lower breast milk intake before starting human milk fortifiers, prolonged time to the initiation of full fortified feeding, and moderate-to-severe bronchopulmonary dysplasia were risk factors for EUGR (P<0.05). CONCLUSIONS It is crucial to reduce the incidence of EUGR by achieving total enteral feeding as early as possible, strengthening breastfeeding, increasing calorie intake in the first week after birth, improving the velocity of weight gain, and preventing moderate-severe bronchopulmonary dysplasia in VPIs.
Female ; Fetal Growth Retardation ; Gestational Age ; Hospitalization ; Humans ; Incidence ; Infant ; Infant, Newborn ; Infant, Premature ; Infant, Very Low Birth Weight ; Prospective Studies ; Risk Factors

Objective To determine the mRNA and protein levels of urokinase plasminogen activator receptors (uPAR) in bone marrow fluid and bone marrow tissue from multiple myeloma (MM) patients and assess association of uPAR level with prognosis of MM. Methods uPAR levels in bone marrow fluid of 22 MM patients at the stable and progressive stages and 18 iron deficiency anemia patients with normal bone marrow (control) were examined by ELISA. Furthermore, uPAR expression in bone marrow tissue was investigated by RT-PCR and Western blot, respectively. The distribution of uPAR in MM cells was examined using immunofluorescence staining. The pathological changes in different stages of MM patients were studied by HE staining. Results uPAR level in bone marrow fluid of MM patients (1.52±0.32 μg/ml) was found to be higher than that in the control group (0.98±0.15 μg/ml). Interestingly, uPAR protein (0.686±0.075 vs. 0.372±0.043, P<0.05) and mRNA (2.51±0.46 vs. 4.46±1.15, P<0.05) expression levels of MM patients at the progressive stage were significantly higher than those at the stable stage. The expression of uPAR in MM bone marrow was confirmed by immunofluorescence staining. Moreover, HE staining revealed a great increased number of nucleated cells and severe impairment of hematopoietic function in the bone marrow of patients with progressive-stage myeloma. Conclusion Our study reveals that uPAR expression is positively correlated with the development and progress of MM.

Objective To determine the mRNA and protein levels of urokinase plasminogen activator receptors (uPAR) in bone marrow fluid and bone marrow tissue from multiple myeloma (MM) patients and assess association of uPAR level with prognosis of MM. Methods uPAR levels in bone marrow fluid of 22 MM patients at the stable and progressive stages and 18 iron deficiency anemia patients with normal bone marrow (control) were examined by ELISA. Furthermore, uPAR expression in bone marrow tissue was investigated by RT-PCR and Western blot, respectively. The distribution of uPAR in MM cells was examined using immunofluorescence staining. The pathological changes in different stages of MM patients were studied by HE staining. Results uPAR level in bone marrow fluid of MM patients (1.52±0.32 μg/ml) was found to be higher than that in the control group (0.98±0.15 μg/ml). Interestingly, uPAR protein (0.686±0.075 vs. 0.372±0.043, P<0.05) and mRNA (2.51±0.46 vs. 4.46±1.15, P<0.05) expression levels of MM patients at the progressive stage were significantly higher than those at the stable stage. The expression of uPAR in MM bone marrow was confirmed by immunofluorescence staining. Moreover, HE staining revealed a great increased number of nucleated cells and severe impairment of hematopoietic function in the bone marrow of patients with progressive-stage myeloma. Conclusion Our study reveals that uPAR expression is positively correlated with the development and progress of MM.
Adult ; Aged ; Bone Marrow ; chemistry ; Disease Progression ; Female ; Fluorescent Antibody Technique ; Humans ; Male ; Middle Aged ; Multiple Myeloma ; chemistry ; pathology ; Receptors, Urokinase Plasminogen Activator ; analysis

The objective of this study was to investigate the mechanical characteristics of implant-abutment interface design in a dental , using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems: model I, the reduced-diameter 3i implant system (West Palm Beach, FL, USA) with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system (Bego, Bremen, Germany) with combination of a conical (450 taper) and internal hexagonal connection; and model III, the Brinemark implant system (Nobel Biocare, Gothenburg,Sweden) with external hexagonal connection. In simulation, a force of 170 N with 45" oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress, principal stress and displacement while the Br Bnemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.
Computer Simulation ; Computer-Aided Design ; Dental Implant-Abutment Design ; statistics & numerical data ; Dental Prosthesis Design ; Dental Stress Analysis ; methods ; Finite Element Analysis ; Humans ; Stress, Mechanical

The objective of this study was to investigate the mechanical characteristics of implant–abutment interface design in a dental implant system, using nonlinear finite element analysis (FEA) method. This finite element simulation study was applied on three commonly used commercial dental implant systems: model I, the reduced-diameter 3i implant system (West Palm Beach, FL, USA) with a hex and a 12-point double internal hexagonal connection; model II, the Semados implant system (Bego, Bremen, Germany) with combination of a conical (456 taper) and internal hexagonal connection; and model III, the Bra°nemark implant system (Nobel Biocare, Gothenburg, Sweden) with external hexagonal connection. In simulation, a force of 170 N with 456 oblique to the longitudinal axis of the implant was loaded to the top surface of the abutment. It has been found from the strength and stiffness analysis that the 3i implant system has the lowest maximum von Mises stress, principal stress and displacement while the Bra°nemark implant system has the highest. It was concluded from our preliminary study using nonlinear FEA that the reduced-diameter 3i implant system with a hex and a 12-point double internal hexagonal connection had a better stress distribution, and produced a smaller displacement than the other two implant systems.

The purpose of this study was to determine whether the fully automated ORTHO AutoVue Innova system, which based on the microcolumn glass sphere technology, is accurate enough to meet immunohematology testing needs at blood banks. 16 IgM anti-C, anti-c, anti-D, anti-E and anti-e dilution series were tested respectively, with corresponding antigen positive red blood cell solutions, by ORTHO AutoVue Innova system and saline medium test. 16 IgG anti-D dilution series were tested respectively with RhD positive red blood cell solutions by ORTHO AutoVue Innova system, polybrene test and antiglobulin test. The accuracies of microcolumn glass sphere technology were analysed, by comparing to the reference assays. The results showed that the sensitivities of the ORTHO AutoVue Innova tests were 1:69.8, 1:33.4, 1:1448.1, 1:139.6 and 1:32.0 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively; the corresponding value of saline medium tests were 1:16.7, 1:16.6, 1:430.5, 1:34.9 and 1:9.9. There were statistically significant differences between the groups of each tests (t values were 14.38, 5.48, 10.25, 12.65 and 9.59 for IgM anti-C, anti-c, anti-D, anti-E and anti-e respectively, p < 0.05). For IgG anti-D, the sensitivities of the ORTHO AutoVue Innova test, polybrene test and antiglobulin test were 1:980.6, 1:181.0 and 1:304.4 respectively. There was statistically significant difference among the 3 groups (F = 51.15, p < 0.01). It is concluded the use of ORTHO AutoVue Innova system for blood group compatibility test can obtain more accurate results than traditional tube tests, it is reliable and safe for routine tests performed in immunohematology laboratories.
Blood Grouping and Crossmatching ; methods ; Coombs Test ; methods ; Humans ; Isoantibodies ; blood ; Materials Testing ; Rho(D) Immune Globulin ; Sensitivity and Specificity

Objective To explore the clinical value of the level of granzyme B and perforin mRNA in urine for the diagnosis of renal transplantation patients with delayed graft function (DGF). Methods Twenty-four cases of renal transplantation patients with DGF were included in this study. Seventy-three u-rine specimens were obtained from these patients who received graft biopsies. Among the 24 cases, ureteral obstruction occurred in 2 cases, vascular thrombosis in 1 case, acute CsA intoxication in 3 cases, acute tubu-lar necrosis (ATN) in 7 cases, ATN complicating borderline change in 2 cases, ATN complicating acute re-jection (AR) in 3 cases, AR in 6 cases. Total RNA was isolated from the urinary cells. Messenger RNA (mRNA) encoding the cytotoxic proteins perforin and granzyme B gene were measured with the quantitative polymerase-chain-reaction assay-(RT-PCR). SPSS13.0 software was used for data analysis. Levels of mRNA were log-transformed before analysis. Results The levels of perforin and granzyme B mRNA in u-rine among the ureteral obstruction group, vascular thrombosis group, acute CsA intoxication group and ATN group were very low. There was no significant difference among these groups (P>0.05). However,among the ATN complicating borderline change group 1.22, 0. 97 fg/μg, ATN complicating AR group (1.20±0.39), (1.07±0.30)fg/μg, and AR group(11.13±0. 33), (1.01±0.19)fg/μg, the levels were increased significantly(P<0.001). Conclusion Measurement of mRNA encoding the cytotoxic proteins perforin and granzyme B gene in urinary cells in renal transplantation patients with DGF could be helpful to etiological diagnosis of DGF, and might be used as an index for the appropriate management of the borderline change.

OBJECTIVETo observe whether the community-based management for patients with hypertension can reduce the incidence of stroke.

METHODSSample of this study included 36 863 people aged 35 years or more who came from a cohort consisting three communities from Tiantan Hospital, Puren Hospital and the Gymnasium Road Hospital in Beijing, based on the surveys on the Integrated Community Intervention Measures of Cerebro-vascular Diseases. Some patients with hypertension in this cohort were followed up and under management. First-ever stroke was considered as the end-point event.

RESULTSIn both groups diagnosed as borderline hypertension or definite hypertension group, the rates of management and control showed an annual increase. The management rate for women was higher, but the control rate was lower (P < 0.05) than that for men. In the third year of this study, the control rate was nearly 18%. With the qualification of control rate, the risk factors of overall stroke, ischemic stroke or hemorrhagic stroke reduced gradually, and the qualification of control rate showed more effects on hemorrhagic stroke. The qualification of control rate in the three years could cause the risk factors of total stroke, ischemic stroke or hemorrhagic stroke to reduce by 25.7%, 19.1%, 27.4%, respectively. When comparing with blood pressure level at < 160/95 mm Hg (1 mm Hg = 0.133 kPa), the level of < 140/90 mm Hg could reduce the risk factors as: 12.3% to total stroke, 12.8% to ischemic stroke and 14.9% to hemorrhagic stroke.

CONCLUSIONPrograms as long-term followed-up and management for patients with hypertension, and control the blood pressure at low level etc. could significantly reduce the incidence of stroke.

Adult ; Aged ; Aged, 80 and over ; China ; epidemiology ; Female ; Humans ; Hypertension ; complications ; epidemiology ; Male ; Middle Aged ; Stroke ; epidemiology ; etiology