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排序方式: 共有5586条查询结果,搜索用时 15 毫秒
81.
Grzegorz Ludwik Golewski 《Materials》2022,15(17)
This study presents test results and in-depth discussion regarding the measurement of the fracture mechanics parameters of new concrete composites based on quaternary blended cements (QBC). A composition of the two most commonly used mineral additives, i.e., fly ash (FA) and silica fume (SF), in combination with nanosilica (nS), has been proposed as a partial replacement for ordinary Portland cement (OPC) binder. Four series of concrete were made, one of which was the reference concrete (REF) and the remaining three were QBC. During the research, the main mechanical parameters of compressive strength (fcm) and splitting tensile strength (fctm), as well as fracture mechanics parameters and the critical stress intensity factor , along with critical crack-tip opening displacements (CTODc) were investigated. Based on the tests, it was found that the total addition of siliceous materials, i.e., SF + nS without FA, increases the strength and fracture parameters of concrete by approximately 40%. On the other hand, supplementing the composition of the binder with SF and nS with 5% of FA additive causes an increase in all mechanical parameters by approximately 10%, whereas an increase by another 10% in the FA content in the concrete mix causes a significant decrease in all the analyzed factors by 10%, compared to the composite with the addition of silica modifiers only. 相似文献
82.
Alexandra E. Butler Jenan Obaid Pearl Wasif Jean V. Varghese Rawan Abdulrahman Dalal Alromaihi Stephen L. Atkin Naji Alamuddin 《Nutrients》2022,14(17)
Objective. Date fruit has been reported to have benefits in type 2 diabetes (T2D), though there is a concern, given the high sugar content, about its effects on glycemic control. Design and Setting. Prospective, interventional, randomized, parallel study. Participants. In total, 79 patients with T2D (39 male and 40 female). Intervention. Participants were randomly allocated to either 60 g date fruit or 60 g raisins daily of the equivalent glycemic index (amount split, given as midmorning and midafternoon snack) for 12 weeks. Main Outcome Measures. The primary outcome was to investigate the effect of date fruit on HbA1c and fasting blood glucose, and their variability, in patients with T2D in comparison to the same glycemic load of raisins. The secondary outcomes were to determine whether date fruit affected cardiovascular risk by measuring fasting lipids, C-reactive protein (CRP), blood pressure, and insulin resistance (IR) as measured by Homeostatic Model Assessment (HOMA-IR). Results. In total, 61 (27 female and 34 male) of 79 patients completed the study. There was no difference between or within groups for HbA1c or HbA1c variability, fasting glucose or glucose variability, insulin resistance (HOMA-IR), insulin sensitivity (HOMA-S), beta cell function (HOMA-B), the disposition index, lipids, systolic (SBP) or diastolic blood pressure (DBP), or C-reactive protein (CRP) (p > 0.05). Conclusion. No improvement in glycemic indices was seen following supplementation of 60 g daily date fruit or raisins, though neither had a deleterious effect on glycemic control over a 12-week period, indicating their safety when consumed in T2D. Additionally, no beneficial therapeutic effects of date fruit on other cardiovascular indices in T2D were seen. 相似文献
83.
The present study aimed to verify the association between adherence to the Mediterranean diet (MD) and anthropometric and health variables. Four-hundred-and-ninety-five college-aged males aged 18–25 participated in this cross-sectional research. The KIMED (Mediterranean Diet Quality Index for children and adolescents) was used to assess the adherence to MD. The following variables were also assessed: body mass (BM), height (HE), body mass index (BMI), body fat percentage (%FAT), lean mass (LEAN), abdominal girth (AG), waist-to-hip ratio (WHR), oxygen saturation (SPO2), systolic blood pressure (SBP), diastolic blood pressure (DBP), double product (DP), and fasting blood glucose (GLU). The results showed that adherence to MD presented a strong negative correlation with most of the anthropometric parameters (BM: r = −0.571; BMI: r = −0.614; %FAT: r = −0.558; and AG: r = −0.564), a moderate or weak correlation with most of the health variables (GLU: r = −0.407; SBP: r = −0.238; DBP: r = −0.217, and DP: r = −0.265) and LEAN (r = −0.497), and a very weak correlation with WHR (r = −0.090). Many anthropometric parameters (BM, BMI, %FAT, LEAN, AG, WHR) present significant correlations with health variables (SBP, DBP, DP, and GLU). We conclude that greater adherence to Mediterranean diet is associated with healthier values of the selected anthropometric and health parameters. Since most of the anthropometric and health parameters present significant correlations among themselves, this finding could be useful in medical diagnosis, health monitoring, and risk detection. Based on the level of adherence to Mediterranean diet and the KIDMED found in the present study, and considering the prevalence of obesity in the Middle East, it is imperative to implement nutritional interventions with the target population of this research to prevent nutrition-related diseases and promote public health. 相似文献
84.
Joon Hee Park Hyun Ji Bang Nak-Hyun Choi Eun-Jin Park 《The journal of advanced prosthodontics》2022,14(5):324
PURPOSEThe purpose of this study is to evaluate translucency and masking ability of translucent zirconia compared to conventional zirconia and lithium disilicate materials.MATERIALS AND METHODSThree types of zirconia blocks with different yttria contents (3Y, 4Y, 5.5Y) and LS blocks (Rosetta SM) were used. Ten specimens for each group were fabricated with 10 mm diameter, with both 0.8 mm and 1.5 mm thicknesses (± 0.02 mm). All groups of zirconia specimens were sintered and polished according to the manufacturer’s instructions. To calculate the translucency parameter (TP), CIELAB value was measured with a spectrophotometer on black and white backgrounds. To investigate the color masking abilities, background shades of A2, normal dentin, discolored dentin, and titanium were used. The color difference (ΔE) was calculated with the CIELAB values of A2 shade background as a reference compared with the values in the various backgrounds. One-way ANOVA and Bonferroni tests were conducted (P < .05).RESULTSThe TP values of zirconia specimens increased as the yttria content increased. All materials used in the study were able to adequately mask normal dentin shade (ΔE < 5.5), but were incapable of masking severely discolored dentin (ΔE > 5.5). On the titanium background, all materials of 1.5 mm thickness were able to mask the background shade, but with a thickness of 0.8 mm, only 3Y-TZP and 4Y-PSZ were able to mask titanium background.CONCLUSIONAll zirconia materials and lithium disilicate specimens used in this study were unable to adequately mask the shade of severely discolored dentin. It is recommended to use 3Y-TZP or 4Y-PSZ with a sufficient thickness of 0.8 mm or more to mask titanium. 相似文献
85.
Gilad Karavani Henry H. Chill Cherut Meirman Einat Gutman-Ido Shmuel Herzberg Tachover Tzipora Tal Imbar Assaf Ben-Meir 《Journal of assisted reproduction and genetics》2022,39(10):2249
Purpose We aimed to investigate the possible effect of SARS-CoV-2 vaccination on sperm quality by evaluating semen analyses of men prior to vaccination and 6–14 months after vaccination.MethodsThis was a retrospective cohort study, conducted in a university-affiliated in vitro fertilization center between October 2021 and March 2022, including men not previously infected with the SARS-CoV-2 virus who received at least 2 doses of the Pfizer-BioNTech (BNT162b2) SARS-CoV-2 vaccine. Semen analyses of samples given pre-vaccination and 6–14 months post-vaccination were analyzed for the parameters of volume, concentration, motility, morphology, and total motile count (TMC) and compared. These parameters were also compared separately for men who received a third (booster) dose and for men with pre-vaccination normal and abnormal sperm. Correlations between time from vaccination and post-vaccination sperm parameters were also assessed.ResultsFifty-eight men were included in the final analysis. Semen volume (2.9 ± 1.4 vs. 2.9 ± 1.6 ml), sperm concentration (42.9 ± 37.9 vs. 51.5 ± 46.2 million/ml), motility (42.5 ± 23.1 vs. 44.3 ± 23.4 percent), morphology (8.8 ± .16.6 vs. 6.6 ± 8.8 percent), and TMC (55.7 ± 57.9 vs. 71.1 ± 77.1 million) were comparable between the pre- and post-vaccination samples. This was true for the entire study cohort, for the subgroup of men who received a third dose and for the subgroups of men with a pre-vaccination normal and abnormal semen samples. No correlation was found between time from vaccination and post-vaccination sperm parameters.ConclusionsThe Pfizer-BioNTech (BNT162b2) SARS-CoV-2 vaccine does not impair any of the sperm parameters over a relatively long-time interval of 6 to 14 months from vaccination.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10815-022-02621-x. 相似文献
86.
The aim of the paper is to determine the influence of the surface treatment on the adhesive properties of steel sheet surfaces and the strength of the adhesive joints of steel sheets. The paper also aims to assess the degree of steel sheets’ surface treatment in the bonding process. Due to the many methods of surface treatment and types of materials, the assessment of the surface treatment method is extremely important in adhesive processes. Two variants of the surface treatment were used: without a paint coating and with a paint coating, divided into two groups (without degreasing and with degreasing). Additionally, in the case of the analysis of the steel samples without the paint coating, mechanical treatment was applied. Two-component epoxy adhesive, prepared on the basis of bisphenol A and a polyamide curing agent, was used to prepare the single-lap adhesive joints of the steel sheets. The tests determined: (i) the adhesive properties of the steel sheets’ surface based on the measurement of the contact angle of polar and apolar liquids (including wettability, work of adhesion, and surface free energy), (ii) surface roughness parameters (PN EN ISO 4287), and (iii) mechanical properties (load capacity and shear strength) of the steel sheets’ adhesive joints (EN DIN 1465). Contact angle measurements of the steel sheet surfaces showed that the polar liquid better reflects the obtained strength results of the analyzed adhesive joints than the apolar liquid. Furthermore, better wettability of the surface of steel sheets with both polar and apolar liquids was obtained for samples whose surface was subjected to degreasing. It can also be concluded that the wettability of the surface can be used as one of the indicators of the degree of the surface treatment for the bonding process. 相似文献
87.
目的 探讨单侧特发性声带麻痹喉返神经/喉上神经电刺激治疗后即刻对主观声音改变、声学参数以及动态喉镜观察结果的影响.方法 选取诊断为单侧特发性声带麻痹的患者,回顾性收集其行喉肌电图检查并同期行神经电刺激治疗前后的动态喉镜及嗓音分析检查结果,分析检查及治疗前后主观声音改变,声学参数(jitter、shimmer、DSI、M... 相似文献
88.
89.
108例支气管哮喘患者舌脉象特征分析 总被引:1,自引:0,他引:1
目的:探讨对支气管哮喘临床辨证有意义的舌脉象客观指标,以辅助临床诊断。方法:应用TP—I型中医舌脉象数字化分析仪检测108例患者舌脉象参数,分析支气管哮喘发作期与缓解期的舌脉象特征。结果:108例支气管哮喘患者的舌象中,舌色以淡红舌、淡紫舌多见,舌苔以白苔、黄苔、薄苔为多见;脉象以弦脉、滑脉、弦滑脉为多见;舌脉象参数中舌色指数、苔色指数、厚苔指数、胖瘦指数在哮喘发作期各证型中有显著性差异(P〈0.05);RPSR1、RPSR3、RPSR4、RBF、RLMS2、PLMP2、RLMS3、RLMP3在哮喘发作期与缓解期有显著性差异(P〈0.05)。结论:支气管哮喘患者的脉象参数、舌色指数、苔色指数、厚苔指数、胖瘦指数、RPSR1、RPSR3、RPSR4、RBF、RLMS2、PLMP2、RLMS3、RLMP3对其辨证分型有重要参考价值。 相似文献
90.
目的:选择影响"易层"贴敷疗法临床疗效的主要技术参数——"药物分层",设定不同水平进行评价,找出最优技术参数水平,优化"易层"贴敷技术操作规程。方法:总计100例踝关节急性软组织损伤患者入选,随机分为两组,每组各50例。治疗方案为第1组:(每天换药)+(三色敷药层联合三黄油膏层);第2组:(每天换药)+(单用三黄油膏层)。治疗观察时间均为6天。评价主要疗效指标:局部疼痛、肿胀、皮肤温度、功能障碍;次要疗效指标:失眠、筋脉拘急及舌苔脉象。全部病例治疗观察结束后进行统计分析。结果:治疗结束,经过统计分析显示,两组治疗后均较治疗前疗效积分有显著改善(P<0.01)。但第1组疗效积分最优,与第2组比较有显著差异(P<0.01)。结论:第1组方案(每天换药+三色敷药层联合三黄油膏层)治疗急性软组织损伤疗效明显优于第2组。提示临床在应用"易层"贴敷疗法治疗疾病的时候应该采用联合药物层次水平的方案治疗最为有效。应该依据此最佳技术参数水平制定"易层"贴敷技术操作规程。 相似文献