Effects of 3.0T magnetic resonance noise on the hearing of children aged 0-12 years with routine hearing protection / 西安交通大学学报(医学版)

Objective To explore the effect of exposure to noise of 3.0T magnetic resonance imaging(MRI)on children's cochlear function.Methods We prospectively recruited 72 children who underwent cranial MRI examination at our hospital from May to November 2018;3M earplugs and sponge mats were used for hearing protection during MRI scanning.Noise level(dBA)of each MRI sequence was detected with a nonmagnetic microphone and a sound level meter.Distortion product otoacoustic emissions(DPOAE)test at 2-7 kHz was performed 24 hours before and 30 minutes after the MRI examination.Paired t-test or Wilcoxon signed-rank test was used to analyze differences in DPOAE amplitude before and after the MRI examination.Results The average noise level of MRI measured in the study was(107.7±3.92)dBA.Compared with that before the MRI examination,the DPOAE amplitude(dB)changed little after the MRI examination;the range of amplitude differences in each age group was as follows:left ear(-0.24-1.10)and right ear(-0.24-0.74)in the 0-1 year-old group;left ear(-0.07-0.59)and right ear(-0.57-0.75)in the 2-5 year-old group;left ear(-0.36-0.44)and right ear(-0.30-0.57)in the 6-12 year-old group.No statistically significant difference was found(correction P＞0.05).Conclusion No potential impact of 3.0T MRI noise on children's cochlear function was observed under routine hearing protection.

Finite element analysis of thumb thrust in lumbar fixed-point rotation manipulation / 中国组织工程研究

BACKGROUND:Lumbar fixed-point rotation operation needs collaborative operation of the doctor's hands,and outputs rotation and thumb thrust.Lumbar disc herniation can be treated through disc displacement and adjusting stress distribution.However,the mechanical effects of thumb thrust and the biomechanical effects of loading direction on manipulative effects remain unclear. OBJECTIVE:To compare the biomechanical difference of lumbar fixed-point rotation manipulation for treating lumbar disc herniation under different thrust directions. METHODS:The L3-5 normal three-dimensional finite element model was constructed and validity was verified.According to the intervertebral disc degeneration Pfirrmann grade,intervertebral disc degeneration was simulated by modifying the L4/5 intervertebral space height,the volume of the nucleus pulposus,as well as the material parameters of the annulus fibrosus,nucleus pulposus,and ligament.Finally,the pathological model of L4/5 moderate disc degeneration with left para-central herniation was constructed,and then the pathological models were used as research objects.Simulation technique:spinning to the right;taking the condition on changing the direction of the thumb thrust to establish three modes of operation(M1:thumb push to the left;M2:thumb push to the right;M3:no thrust push).The protrusion displacement and the disc stress,and the stress and strain of the facet joint cartilage were compared in the three operating modes. RESULTS AND CONCLUSION:(1)Maximum displacement value of L4/5 disc herniation:displacement was 2.672 3 mm for M1,1.156 1 mm for M2,1.826 4 mm for M3,M1＞M3＞M2.(2)The maximum Von Mises stress of L4/5 discs was 1.846 7 MPa for M1,0.419 0 MPa for M2,and 1.257 9 MPa for M3,M1＞M3＞M2.(3)L4/5 bilateral small cartilage produced different degrees of contact stress changes:It was 0.485 5 MPa for M1,0.026 7 MPa for M2,and 0.441 4 MPa for M3,M1＞M3＞M2.Right cartilage contact force was 0.000 5 MPa for M1,0.025 9 MPa for M2,and 0.001 3 MPa for M3,M2＞M3＞M1;the left greater than the right,M1 had the highest value;cartilage strain was consistent with contact stress changes.(4)Different operation modes will have some biomechanical influences on the diseased intervertebral disc and accessory structure.The M1 operation mode can maximize the displacement of protrusion,disc stress and left joint cartilage contact,which can better promote disc displacement,balance stress distribution and reduce facet joint disorder,so the operation is better.

WGCNA-based identification of novel T-cell exhaustion-related gene signatures to predict the prognosis and response to immunotherapy of osteosarcoma patients / 肿瘤

Objective:To screen T-cell exhaustion-related signature genes as the prognostic marker for osteosarcoma and establish a prognostic model for osteosarcoma patients based on weighted gene co-expression network analysis(WGCNA)and Least absolute shrinkage and selection operator(LASSO)-COX regression analysis. Methods:GSE21257 dataset was downloaded from Gene Expression Omnibus(GEO)database for the establishment of the prognostic model for osteosarcoma.4 T-cell exhaustion-related gene sets were downloaded from The Molecular Signatures Database(MisgDB)and their enrichment scores in GSE21257 samples were calculated by single sample gene set enrichment analysis(ssGSEA).WGCNA was carried out to screen the gene module that is highly associated with T-cell exhaustion based on ssGSEA results followed by GO(Gene Ontology)and KEGG(Kyoto Encyclopedia of Genes and Genomes)analysis of the biological processes and signaling transduction pathways that those genes are involved in.The signature genes that are highly associated with the prognosis of osteosarcoma patients were obtained through LASSO-COX regression and a prognostic model was established based on these signature genes.Osteosarcoma-related expression profile data from the GSE21257 and TAEGET datasets on XENA were downloaded from the Gene Expression Omnibus.Clinical information for the training and validation sets was obtained.T-cell exhaustion-related genes were screened using a weighted correlation network analysis.Realtime fluorescence quantitative PCR,COX regression analysis,external dataset and nomogram were used to evaluate the reliability and accuracy of the prognostic model.A immunotherapy-related dataset was used to assess the efficacy of this prognostic model for the prediction of patients'responses to immunotherapy. Results:Analysis results based on the ssGSEA scores showed that T-cell exhaustion-related genes were related to the metastasis and age of osteosarcoma patients.Many T-cell exhaustion-related genes were found to be differentially expressed in metastatic and non-metastatic osteosarcoma patients.1 256 T-cell exhaustion-related genes were identified through WGCNA and these candidate markers were mainly distributed in structures like secretory granule membranes and endocytic vesicles and were involved in T-cell activation.COX regression analysis screened 68 significant prognostic markers out of the 1 256 genes,and 12 signature genes were further confirmed with LASSO-COX regression analysis.A prognostic model was established based on the 12 signature genes.Results of real-time fluorescence quantitative PCR showed a similar trend in the expression of most of the signature genes in different osteosarcoma cell lines.COX regression analysis of the internal and external datasets verified that the risk score calculated with the prognostic model was an independent prognostic factor for osteosarcoma patients,and high-risk score was associated with poor prognosis of the patients.Receiver operating characteristic(ROC)curves demonstrated excellent prognostic efficacy of the model.Nomogram analysis verified the prognostic model is highly accurate and reliable in predicting the prognosis of osteosarcoma patients.Analysis using the immunotherapy-related dataset indicated that this prognostic model could also be used to predict patients'responses to immunotherapy. Conclusion:The 12 signature gene(CD300LB,TRO,SNX3,VENTX,PPM1M,DOT1L,CDC37,NAT9,TRMT1,PPP1R3C,CHTF18 and NSUN5)-based prognostic model can effectively predict the prognosis and responses to immune check-point inhibitors for osteosarcoma patients,which may provide evidence for the prediction of prognosis as well as the selection of immunotherapy plans in clinical practice.

Effects of RNA demethylase FTO inhibitor on function ofglioblastoma stem cells / 中国药理学通报

Aim To investigate the effect of m6A demethylase FTO inhibitor(FB23-2)on human glioblastoma stem cell activity. Methods The effects of FB23-2 and Temozolomide on GSC were detected by CCK-8 assay and neurosphere formation assay. The effect of FB23-2 on self-renewal of GSC was detected by limited dilution assay in vitro. The effect of FB23-2 on the proliferation of GSC was detected by EdU method. The effect of FB23-2 on apoptosis of glioblastoma stem cells was detected by flow cytometry. Results CCK-8 assay showed that FB23-2 could effectively inhibit the cell viability of GSC with IC50 values of 7.11 μmol·L-1 and 4.63 μmol·L-1,respectively. The size and number of GSC neural sphere in FB23-2 treatment group were significantly reduced compared with control group. In vitro limited dilution experiment showed that FB23-2 effectively inhibited the self-renewal ability of GSC. EdU incorporation experiment showed that compared with the control group,the treatment group decreased to(70.59±13.74)% and(50.33±4.53)%,respectively. The apoptotic rates of the treated group were(12.16±1.90)% and(16.77±1.17)% by flow cytometry. Conclusions FTO inhibitor FB23-2 can effectively inhibit GSC growth,self-renewal and the formation of neural sphere. In addition,FB23-2 can inhibit the proliferation of GSC and induce its apoptosis.

Surface roughness, gloss and sequential polishing times of various chairside computer aided design/manufacturing restorative materials / 北京大学学报(医学版)

OBJECTIVE@#To investigate the effect of polishing on surface roughness, gloss and optimum polishing time of various computer aided design/computer aided manufacturing (CAD/CAM) restorative materials and to provide a proper polishing procedure for dental clinicians.@*METHODS@#Five CAD/CAM restorative materials including vita mark Ⅱ (VM), vita enamic (VE), lava ultimate (LU), shofu block HC (SB) and brilliant crios (BC) were selected. Six specimens were prepared for each material. The specimen was fixed on a custom-made polishing apparatus and sequentially polished with Sof-Lex poli-shing disk system including medium disk (with abrasive particle sizes of 10-40 μm), fine disk (with abrasive particle sizes of 3-9 μm) and superfine disk (with abrasive particle sizes of 1-7 μm). Surface roughness (Ra value) and gloss value were measured every 10 seconds until the numerical values were no longer changed. Then the surface roughness, gloss value and polishing time were recorded and the specimen was moved to the next sequence of polishing. Finally, statistical analysis was performed using SPSS 24.0.@*RESULTS@#For all the restorative materials, the Ra values were significantly reduced (P < 0.05) and the gloss values were significantly increased (P < 0.05) after sequentially polishing with Sof-Lex disks. No significant difference was detected among Ra values of all the tested materials (P>0.05) after sequential polishing. The gloss values of LU [(68.1±4.5) GU] and BC [(68.2±5.8) GU] were significantly higher than those of VE [(48.1±8.1) GU] and BC [(53.2±5.8) GU], P < 0.05. To obtain optimal surface smoothness, VM cost the shortest polishing time [40 (30, 55) s] among all the restorative materials (P < 0.05). No significant differences in the total polishing time were observed among VE [140 (135, 145) s], LU [130 (120, 140) s], SB [140 (130, 150) s] and BC [130 (120, 140) s], P>0.05.@*CONCLUSION@#The surface roughness of all CAD/CAM restorative materials were decreased after sequentially polishing with Sof-Lex disk system. To obtain the smoothest surface, different types of restorative materials might need different polishing times using Sof-Lex polishing disk system. For ceramic restorative material VM, we recommend polishing only with medium disk for 40 s. For hybrid restorative material VE and composite restorative material LU, SB and BC, we recommend polishing with medium disk, fine disk and superfine disk in sequence for 130-140 s in total.

Evaluation of wear property of Giomer and universal composite in vivo / 北京大学学报(医学版)

OBJECTIVE@#To observe the wear performance of Giomer and universal composite for posterior restorations by 3D laser scan method, in order to guide the material selection in clinic.@*METHODS@#In this study, 48 patients (108 teeth) were selected according to the inclusion and exclusion criteria. All the patients in need of a minimum of 2 Class Ⅰ and/or Class Ⅱ restorations were invited to join the study. The teeth were restored with Giomer (Beautifil Ⅱ, BF) and universal composite (Filtek Z350, Z350) randomly. The restorations were evaluated at baseline and after 6-, 18-, 48-month using the modified United States Public Health Service (USPHS) criteria for clinical performance. The in vivo images and gypsum replicas were taken at each recall. A 3D-laser scanner and Geomagic Studio 12 were used to analyze the wear depth quantitatively. Statistical analysis was performed with SPSS 20.0.@*RESULTS@#After 4 years, 89.6% patients were recalled. The survival rate of both materials was 95.8% (Kaplan-Meier survival analysis). Seven restorations of the two materials failed due to loss of restoration, bulk fracture, secondary caries and pulp necrosis. The wear patterns of restorations were divided into 2 classes. Pattern Ⅰ: occlusal contact areas showed the deepest and fastest wear depth; pattern Ⅱ: the wear depth was slow and uniform. Both materials showed a rapid wear in the first 6 months. Then the wear rate was decreased. The occlusal wear depth after 4 years were (58±22) μm and (54±16) μm for BF group and Z350 group respectively, which were in accordance with the American Dental Association (ADA) guidelines (wear depth for 3 years < 100 μm). No significant differences (P>0.05) were observed between the two groups. Regarding the restorations with wear pattern Ⅰ, the wear depth of BF group was higher than Z350 group at 6- and 48-month (P < 0.05), while there was no significant difference between restorations with wear pattern Ⅱ (P>0.05).@*CONCLUSION@#Within the limitation of the study, after 4 years, the survival rate and wear resistance of Giomer met ADA guidelines for tooth-colored restorative materials for posterior teeth. When the two materials were applied in occlusal contact areas, wear resistance of Giomer was slightly lower than universal composite resin. No significant difference was found when they were applied in none of the occlusal contact areas.

Effect of intrapulpal pressure on the bonding strength of resin cement to dentin / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the effect of intrapulpal pressure simulation on the micro-tensile bond strength (μTBS) of resin cement to dentin.@*METHODS@#Thirty extracted human third molars were selected. Occlusal enamel was removed to expose dentine surface and teeth with residual dentin thickness of 0.5-2.5 mm were selected. Dye permeation through dentin tubules with or without intrapulpal pressure (IPP) simulation, or after Single Bond Universal (SBU) application on dentin surface with IPP simulation were observed at the end of 0 min, 5 min, 30 min and 2 h. The teeth with residual dentin thickness of (1.0±0.1) mm were divided into 2 groups with IPP simulation of 15 or 0 cmH2O (1 cmH2O=0.098 kPa), which was maintained for 30 min before bonding procedure. SBU was applied on the dentin surface and light cured, then RelyX Ultimate (RLX) cement was heaped on the dentin surface (diameter=10 mm, height=4 mm) and light-cured. After the dentin-resin cement samples were stored in distilled water for 24 h at 37 °C, the samples were cut into beams with cross sectional area of 0.9 mm×0.9 mm for μTSB testing (n=100). The data were analyzed with two independent samples t-test (α=0.05). The fracture mode was observed using scanning electron microscopy (SEM). The results were analyzed with Fisher exact test (α=0.05). The rest of dentin-resin cement samples (five samples for each group) were cut perpendicular to the bonding interface and the morphology of the bonding interface was observed using SEM.@*RESULTS@#The dye permeation through dentin tubules with IPP simulation was faster than those without IPP simulation. The μTSB of RLX to dentin with and without IPP simulation were (26.26±9.78) MPa and (28.70±9.0) MPa, respectively. The most frequent fracture mode was mixed-fracture mode. There was no significant difference between the two groups for neither bond strength nor fracture types distribution (P>0.05). Regarding the morphology of dentin-resin cement bonding interface, both groups showed 4-8 μm finger-like resin tags.@*CONCLUSION@#With SBU pretreatment, the IPP simulation had no influence on the immediate bond strength of RLX to dentin.

Influence of setting time on bond strength of different bioactive pulp capping materials with dental adhesive / 北京大学学报(医学版)

OBJECTIVE@#To investigate influence of setting time on bond strength of different bioactive pulp capping materials with self-etch or etch-and-rinse adhesive.@*METHODS@#Sixty specimens were prepared for each of the three tested capping materials, namely mineral trioxide aggregate (MTA), iRoot BP Plus (BP) and iRoot FS (FS). Specimens of each material were divided into three groups and bonded at three setting time points of the materials respectively: initial setting time (4 h for MTA, 2 h for BP and 20 min for FS), 24 h after application and 7 d after application. The specimen surfaces of each group were treated with self-etch mode or etch-and-rinse mode of one universal adhesive (Single Bond Universal, SBU) (n=10). The bonding area was restricted to a round area with 3 mm diameter, on which composite cylinders were build up with flowable composite and light cured completely. The shear bond strength was tested immediately with a shear strength tester and fracture mode was observed under stereo microscope and recorded. The mean shear bond strength for each group was analyzed with SPSS 19.0 software ANOVA method. The surface morphology of each material was observed after setting and acid treatment under scanning electron microscope.@*RESULTS@#There was no significant difference among the three tested materials at either initial setting point or 7 d after application (P<0.05). The bond strength of MTA was significantly higher than those of BP and FS 24 h after application in both bonding modes (P<0.05). For all the three tested materials, shear bond strength was significantly higher for complete setting group than for initial setting group of the same material (P<0.05). Under scanning electron microscope, the characteristic crystal patterns could be observed on the three bioactive materials surfaces after complete setting, the size of which was bigger for MTA than for BP and FS. These features were lost to some extent after self-etch primer application or phosphoric acid etching.@*CONCLUSION@#Based on the present results, adequate bond strength can be obtained for FS at initial setting time, which is comparable with BP and MTA. This implies that clinically composite restoration can be placed over bioactive direct capping materials after shortened initial setting process in one visit.

Effect of pathological fracture on the prognosis of patients with limb osteosarcoma: A meta-analysis / 肿瘤

Objective: To evaluate the effect of pathological fracture on the prognosis of patients with limb osteosarcoma. Methods: A computer-based online search was performed by using EMBASE, Cochrane Library, PubMed, CNKI (China National Knowledge Infrastructure), Wanfang database, VIP database and Chinese Biomedical Literature Database. Relevant studies on clinical outcome of limb osteosarcoma patients with pathological fracture vs without pathological fracture were collected and the quality of the studies were assessed using Newcastle-Ottawa Scale. The data of the studies were abstracted. Meta-analysis was performed using Stata 12.0 software. Results: Ten studies of 2604 cases entered the Meta-analysis, including 356 cases of osteosarcoma with pathological fracture (study group) and 2248 cases of osteosarcoma without pathological fracture (control group). This Meta-analysis revealed that the patients in the study group had poor three-year overall survival (OS) [odds ratio (OR) = 2.57, 95% confidence Interval (CI): 1.54-4.29; P = 0.000) and five-year OS (OR = 1.57, 95% CI: 1.05-2.34; P = 0.029) than those in the control group. Furthermore, there were significant differences in three-year event-free survival (EFS) (OR = 1.87, 95% CI: 1.21-2.87; P = 0.005) and five-year EFS (OR = 1.52, 95% CI: 1.16-1.99; P = 0.002) between the study group and control group. No significant difference was found in the rate of local recurrence between the two groups (P > 0.05), and there was also no significant difference in the rate of local recurrence between patients who were treated with amputation and limb salvage in pathological fracture subgroup (P > 0.05). Conclusion: This meta-analysis suggests that the prognosis of limb osteosarcoma patients with pathological fracture is more worse than that of the patients without pathological fracture. There is no higher risk in the rate of local recurrence after limb salvage in patients with pathological fracture.

Expression and clinical signiifcance of PAK5 protein expression in osteosarcoma / 中国癌症杂志

Background and purpose: p21-activated kinase 5 (PAK5) is a recently identified member of PAKs that regulate many intracellular processes such as cytoskeleton remodeling, cell proliferation, cell differentiation, gene transcription and cell apoptosis. Recently, studies found that PAK5 was overexpressed in some cancer such as gastric and colon cancer. However, the expression status and biological function of PAK5 in osteosarcoma are not clearly known. The objective of this study was to investigate the expression of PAK5 in osteosarcoma tissue and their relationships with the prognosis of osteosarcoma. Methods: The expression of PAK5 was detected by using immunohistochemical method in 92 specimens of human osteosarcoma tissues and 33 cases of osteoclastoma tissue, respectively. Results: The positive rate of PAK5 was 71.7% (66/92) in all the 92 cases of osteosarcoma. PAK5 expressions were not related to clinical variables such as gender, age, tumor location, tumor size, histological type and local recurrence, but signiifcantly related to Enneking grade, tumor cell necrosis rate and lung metastasis, and the high expression of PAK5 may reduce the efifciency of chemotherapy. Survival analysis indicated that high expression of PAK5 correlated with poor prognosis of patients with osteosarcoma. Univariate survival analysis showed that the signiifcant prognostic factors were tumor size, Enneking grade, local recurrence, lung metastasis and expression levels of PAK5. COX multivariate regression identified that the PAK5 expression levels (P=0.001) and lung metastasis (P=0.015) were independent prognostic factors of patients with osteosarcoma. Conclusion:The positive expressions of PAK5 closely correlate with Enneking grade, tumor cell necrosis rate and lung metastasis. Detection of PAK5 may be used as a molecular marker for prognosis of osteosarcoma. The high expression of PAK5 may reduce the efifciency of chemotherapy.

Multitargeted antiangiogenic tyrosine kinase inhibitors in combination with chemotherapy in patients with advanced non-small cell lung cancer: A Meta-analysis / 肿瘤

Objective: To evaluate the efficacy and safety of chemotherapy alone or combined with multitargeted antiangiogenic TKI (tyrosine kinase inhibitor) for patients with advanced NSCLC (non-small cell lung cancer). Methods: A computer-based online search was performed by using EMBASE, Cochrane Library, PubMed, CNKI (China National Knowledge Infrastructure), Wanfang and VIP databases and Chinese Biomedical Literature Database. Studies of RCT (randomized controlled trial) in accordance with the inclusion and exclusion criteria were included. Quality of the studies was assessed using Jadad score. Data were extracted from the studies by 2 independent reviewers. The Meta-analysis was performed by Stata 12.0 software. Results: Nine RCTs (totally 5 286 patients) were eligible. Meta-analysis showed that there was significant improvement in ORR (objective response rate) [OR (odds ratio): 1.51, 95% CI (confidence interval): 1.21-1.87, P = 0.000] and PFS (progression-free survival) [HR (hazard ratio): 0.83, 95% CI: 0.77-0.88, P = 0.000) in multitargeted antiangiogenic TKI plus chemotherapy group, as compared with chemotherapy along group. Though the pooled HR (HR = 0.94, 95% CI: 0.87-1.01, P = 0.081) for OS (overall survival) showed no significant difference between the two groups. However, there were higher rates of diarrhea (OR: 2.09, 95% CI: 1.48-2.96, P = 0.000), rash (OR: 2.30, 95% CI: 1.59-3.29, P = 0.000), hypertension (OR: 3.30, 95% CI: 2.69-4.06, P = 0.000), hemorrhage (OR: 1.49, 95% CI: 1.07-2.06, P = 0.018), anorexia (OR: 1.45, P = 1.01-2.07, P = 0.042), stomatitis (OR: 2.13, 95% CI: 1.29-3.52, P = 0.003) and hand-foot skin reaction (OR: 4.55, 95% CI: 1.77-11.71, P = 0.002). Conclusion: In comparison with chemotherapy alone, multitargeted antiangiogenic TKI plus chemotherapy had better therapeutic effects on NSCLC. Meanwhile, it also increases the rates of adverse effects such as diarrhea, rash, hypertension, hemorrhage, anorexia, stomatitis and hand-foot skin reaction, which should be prevented and symptomatically treated. Copyright © 2013 by TUMOR.

The durability of three self-etch adhesives bonded to dentin / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the durability of self-etch adhesives bonded to dentin in vitro.</p><p><b>METHODS</b>Forty-two extracted human molars were selected and occlusal dentin surfaces were exposed. The teeth were randomly distributed into three groups based on adhesives applied. The one-step self-etch adhesive B(Adper Prompt) and C(G-Bond) and two-step self-etch adhesive A (Clearfil SE bond) were used. After application of the adhesives to the dentin surfaces, composite crowns were built up, after 24 h water storage, the teeth were sectioned longitudinally into sticks (1.0 mm×1.0 mm bonding area) for microtensile testing or slabs (1 mm thick) for scanning electron microscopec (SEM) observation. Bonding strength (mTBS) and nano-leakage were evaluated immediately after cutting or after 6 months in water. The mTBS was analyzed using one-way ANOVA (SPSS 13.0). The nanoleakage was observed by SEM with a backscattered electron detector.</p><p><b>RESULTS</b>Both adhesives and water storage time affected the mTBS. All adhesives showed decreased bond strength after six-month water aging [A dropped from (40.60 ± 5.76) MPa to (36.04 ± 3.15) MPa; B dropped from (19.06 ± 1.50) MPa to (11.19 ± 1.97) MPa; C dropped from (17.75 ± 1.10) MPa to (9.14 ± 1.15) MPa] (P < 0.05). B and C showed lower mTBS than A after aging (P < 0.05). Compared to A, nanoleakage was more obvious after aging for B and C.</p><p><b>CONCLUSIONS</b>All self-etch adhesives tested were probably influenced by water aging, however, the two-step adhesive showed better durability than the one-step adhesives.</p>

Plasma lipid level and incidence of dyslipidemia in workers of Chongqing enterprises and institutions / 中华心血管病杂志

<p><b>OBJECTIVE</b>To examine the plasma lipid level and distribution of dyslipidemia in workers of Chongqing enterprises and institutions.</p><p><b>METHODS</b>By using cluster sampling method, 20 000 workers of Chongqing enterprises and institutions aged 18 to 60 were selected as target population from January to October, 2009. We conducted questionnaire survey, physical and laboratory examinations including total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Workers were divided into 18 - 29 years old group, 30 - 39 years old group, 40 - 49 years old group and 50 - 60 years old group. Characteristic and distribution of dyslipidemia were analyzed.</p><p><b>RESULTS</b>Total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were significantly different in various age group (all P < 0.01). TC, TG, HDL-C and LDL-C levels in the 30 years and over groups were all significantly higher than in the under 30 years old group(all P < 0.01). The TG levels in the 40 - 49 years old group and the 50 - 60 years old group were similar (P > 0.05). After adjusting for age, TC, TG, HDL-C and LDL-C levels in males were all significantly higher than in females (all P < 0.01). The incidence of dyslipidemia in this population was 35.01% and significantly higher in males than that of females (58.27% vs. 11.01%, P < 0.01). The incidence of dyslipidemia increased with aging (P < 0.01).</p><p><b>CONCLUSIONS</b>The prevalence of dyslipidemia is high in Chongqing enterprises and institutions. The incidence of dyslipidemia is higher in males than in females and higher among the 30 years and over workers than that of under 30 years old workers.</p>

Application of a method of improving the quality of sampling in review to determine the light areas of endemic fluorosis in quality control / 中国地方病学杂志

ObjectiveTo study an application of a method of improving the quality of sampling in review to determine the light areas of endemic fluorosis(referred to as endemic fluorosis) in quality control. Methods Of 15 light endemic fluorosis township(town), six were randomly sampled, and the prevalence of dental fluorosis in 22 village primary school children aged 8 to 12 were reviewed to determine the improved quality of sampling in Xuyong county Sichuan province. ResultsSix townships(towns) were selected by simple random sampling from 15 endemic fluorosis townships(towns) for review inspection in Xuyong country. A total of 22 villages were verified, accounting for 22.7％ of the total 97 villages verified. Of the 416 children for review inspection of dental fluorosis, 383 children were positive. The consistent rate of children' s dental fluorosis was 92.07％, and the verification to be slight villages was up to 21 endemic villages, accounting for 95.45％. ConclusionsThe application of a method of improving the quality of sampling can improve the efficiency of quality control, and improve the accuracy. It is a novel quality control method.

Influencing factors on behavior related to HIV testing among female commercial sex workers based on the Structural Equation Model / 中华流行病学杂志

Objective To investigate the influencing factors on behavior related to HIV testing among female commercial sex workers under Structural Equation Model (SEM).Methods In Chongqing,Sichuan,Guangxi,Xinjiang provinces,1613 female commercial sex workers were participated in a questionnaire survey.Factors on behaviors related to HIV testing among female commercial sex workers were analyzed based on SEM.Results Influencing factors on behaviors related to HIV testing among female commercial sex workers would include social status,knowledge on AIDS,risk through self-evaluation,condom use,frequency of sexual services etc.GFI,AGFI,RMR were 0.9952,0.9898 and 0.0115 respectively.Conclusion Social status,knowledge on AIDS,risk through self-evaluation,condom use and frequency of sexual services were affecting the behaviors related to HIV testing among female commercial sex workers.

Utility of waist-to-height ratio in detecting central obesity and related adverse cardiovascular risk among normal weight adults / 中华预防医学杂志

<p><b>OBJECTIVE</b>To detect central obesity and related adverse cardiovascular disease risk factors by waist-to-height ratio (WHR) among normal weight adults in Chongqing area.</p><p><b>METHODS</b>A total of 20 000 participants aged 18 - 59 from one hour economic cycle of Chongqing area were selected by group sampling method. We measured the height, waist circumference (WC), body weight, blood pressure, blood lipid and blood sugar. Body Mass Index (BMI) and WHR were computed. We analyzed the differences of the correlated indexes between non-central obesity group (WHR < 0.5) and central obesity group (WHR ≥ 0.5) of those had normal weight (18.5 ≤ BMI (kg/m(2)) < 24). And we used logistic regression method to analyze the relation between central obesity and related adverse cardiovascular risk factors.</p><p><b>RESULTS</b>Among 11 612 normal weight subjects, 1801 (15.51%) participants were normal weight central obesity. Of non-central obesity group and central obesity group, the levels of waist WC were (73.71 ± 5.91) and (84.47 ± 4.58) cm (F = 328.74, P < 0.01); diastolic blood pressure levels were (72.85 ± 10.30) and (78.22 ± 11.90) mm Hg (1 mm Hg = 0.133 kPa, F = 23.62, P < 0.01); triglyceride levels were (1.22 ± 0.95), (1.97 ± 1.91) mmol/L (F = 114.70, P < 0.01); total cholesterol levels were (4.66 ± 0.84) and (5.04 ± 0.92) mmol/L (F = 13.10, P < 0.01); high density lipoprotein levels were (1.41 ± 0.31), (1.25 ± 0.29) mmol/L (F = 29.44, P < 0.01); low density lipoprotein levels were (2.65 ± 0.74) and (3.03 ± 0.77) mmol/L (F = 9.98, P < 0.01); glycemia levels were (4.94 ± 0.82) and (5.25 ± 1.37) mmol/L (F = 47.21, P < 0.01). The results of the logistic regression analysis showed the central obesity normal weight group was 1.28 (1.02 - 1.60), 1.49 (1.20 - 1.84), 2.24 (1.92 - 2.60), 1.77 (1.53 - 2.05), 1.58 (1.15 - 2.16) and 1.31 (1.06 - 1.63) times more likely than the normal group to have significantly elevated levels of systolic blood pressure, diastolic blood pressure, triglyceride, high density lipoprotein, low density lipoprotein and blood glucose.</p><p><b>CONCLUSION</b>WHR can effectively reflect the normal weight central obesity and the risk factors of cardiovascular disease;the adverse cardiovascular disease risk was high among normal weight central obesity adults.</p>

Effects of application methods of self-etching adhesives on resin-dentin bonding / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of application time and rubbing action of self-etching adhesives on resin-dentin bond strength and interface morphology in vitro.</p><p><b>METHODS</b>Caries-free human third molars were wet ground to expose dentin surface. Three self-etching bonding agents were applied with varying application time and with/without rubbing. The microtensile bond strength and interface morphology were evaluated.</p><p><b>RESULTS</b>When etching time was shortened, normal and prolonged, the bond strength was bonding agent 1 (Adper Prompt): (16.30 +/- 2.59), (23.13 +/- 2.56), (22.28 +/- 2.83) MPa, bonding agent 2 (Xeno III): (15.17 +/- 6.07), (34.50 +/- 3.64), (24.87 +/- 7.01) MPa, bonding agent 3 (Clearfil SE Bond): (29.92 +/- 3.32), (42.21 +/- 6.28), (41.07 +/- 3.93) MPa. When etching was applied with and without rubbing, the bond strength was bonding agent 1 (23.13 +/- 2.56), (12.53 +/- 3.73) MPa, bonding agent 2 (23.98 +/- 3.86), (34.50 +/- 3.64) MPa, bonding agent 3 (48.37 +/- 4.95), (42.21 +/- 6.28) MPa.</p><p><b>CONCLUSIONS</b>Shortening application time decreased bond strength of self-etching adhesives, while prolonging application time did not increase bond strength of self-etching adhesives. Not all self-etching adhesives applied with rubbing showed increased bond strength to dentin, which is product-dependent. Manufactures' instructions should be followed to achieve optimum bonding.</p>

Microtensile bond strengths of one-step self-etching adhesive systems / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the microtensile bond strength of one-step self-etching adhesives to dentin in vitro.</p><p><b>METHODS</b>Three commercially available one-step self-etching bonding systems (group A: Adper Prompt, group B: Clearfil S(3) Bond, group C: Xeno III) were compared with two-step self-etching adhesive (group D: Clearfil SE Bond) in this study. The microtensile bond strength was determined with microtensile tester and the fractured bonding surfaces were observed under stereomicroscope and scanning electronic microscope (SEM). The mean bond strengths were analyzed using one-way ANOVA test (P < 0.05).</p><p><b>RESULTS</b>Mean microtensile bond strengths of group C, B, A and D were (34.59 +/- 3.46), (30.46 +/- 3.82), (23.36 +/- 2.55) and (45.06 +/- 5.29) MPa, respectively. Group D showed the highest bond strength (P < 0.01).</p><p><b>CONCLUSIONS</b>Two-step self-etching adhesive had a higher bond strength than one-step self-etching adhesive systems, although all of them can satisfy the clinical requirements.</p>