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1.
崔娜  王小刚  董磊 《西部医学》2022,34(8):1230-1234
目的 探讨血管内超声虚拟组织学成像(VH-IVUS)与实时剪切弹性成像技术(SWE)评估颈动脉斑块稳定性及脑梗死的价值。方法 选取2018年12月~2020年12月在中国人民解放军联勤保障部队第960医院就诊的颈动脉粥样硬化斑块患者130例(201个斑块),分析不同性质斑块VH-IVUS评分及平均杨氏模量差异,及评估稳定性斑块的价值。130例颈动脉粥样硬化斑块患者近期发生脑梗死53例(脑梗死组),无脑梗死77例(无脑梗死组),比较两组甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、VH-IVU评分及平均杨氏模量水平,同时分析VH-IVUS评分及平均杨氏模量评估脑梗死的价值。结果 易损性斑块VH-IVUS评分高于稳定性斑块(P<0.05),而平均杨氏模量低于稳定性斑块(P<0.05);VH-IVUS评分、平均杨氏模量评估稳定性斑块的ROC曲线下面积分别为0.789和0.875。脑梗死组TG、LDL-C明显高于无脑梗死组(P<0.05),而HDL-C明显低于无脑梗死组(P<0.05);脑梗死组斑块VH-IVUS评分明显高于无脑梗死组(P<0.05),而平均杨氏模量明显低于无脑梗死组(P<0.05);VH-IVUS评分、平均杨氏模量评估脑梗死的ROC曲线下面积分别为0.658和0.822。结论 VH-IVUS与SWE技术评估颈动脉斑块稳定性及脑梗死方面有较好的价值,其中SWE评估价值较高。  相似文献   
2.
目的:研究Piezo1机械敏感性离子通道对骨细胞的调控作用。方法:应用课题组研发的流体剪切力(FSS)加载装置,使用免疫荧光探究FSS对Piezo1通道在MLO-Y4中影响的最佳强度;对Piezo1使用FSS、激动剂Yoda1或阻滞剂GsMTx4进行干预。使用Western Blot探究Cleaved Caspase-3、Bcl-2、Bax凋亡相关蛋白的表达量;使用Hoechst-33258以及流式细胞凋亡检测MLO-Y4骨细胞的凋亡比例。结果:免疫荧光染色结果表明FSS对MLO-Y4骨细胞中Piezo1的表达呈现先增加后降低的单峰趋势,其中以9 dyne/cm2加载30 min为最佳刺激条件。使用Yoda1抑制MLO-Y4细胞凋亡(P<0.05),使用GsMTx4促进MLO-Y4细胞凋亡(P<0.05)。Piezo1介导的FSS抑制MLO-Y4细胞凋亡(P<0.05)。结论:Piezo1机械敏感性离子通道介导的FSS在9 dyne/cm2条件下抑制MLO-Y4骨细胞凋亡,且FSS在该条件下可以有效逆转Piezo1阻滞剂GsMTx4在4 μmol/L作用0.5 h下促进MLO-Y4细胞凋亡作用。  相似文献   
3.
目的研究不同存储条件下6种通用型粘接剂及喷砂条件对聚醚醚酮(PEEK)与复合树脂之间粘接强度和耐久性的影响。 方法将PEEK材料切割成12个边长为2 cm的正方体试件。对其中6个试件进行氧化铝喷砂处理。6种通用型粘接剂为:Tetric N-Bond Universal(TNU)、Single Bond Universal(SBU)、DX.BOND UNI(DXB)、Selective Etch Bond(SEB)、Gluma Bond Universal(GBU)、Prime & Bond Universal(PBU)。实验分为7组,每组包含4个喷砂面和4个未喷砂面。7种表面处理方法分别为:不使用粘接剂(对照组)和6种通用型粘接剂(实验组:TNU组、SBU组、DXB组、SEB组、GBU组、PBU组)。经表面处理后,将流动复合树脂F00注入透明模具并将其无压力置于试件表面后进行光照固化。试件分别在37 ℃恒温水浴24 h或冷热循环3000次后进行剪切粘接强度测试。使用松风EyeSpecial C-Ⅳ口腔专用相机微距模式进行断面拍照并进行断裂模式分析。采用SPSS 23.0软件Three-Way ANOVA(冷热循环、粘接剂与喷砂)与Tukey方法对各组数据进行统计分析(α = 0.05)。 结果24 h水浴条件下,TNU组分别获得不喷砂组(9.92 ± 1.19)MPa与喷砂组(9.97 ± 1.03)MPa最高粘接强度;冷热循环3000次后PBU组分别获得不喷砂组(6.75 ± 0.99)MPa与喷砂组(7.22 ± 1.30)MPa最高粘接强度。三因素分析结果显示:冷热循环(F = 3 045.429,P<0.001)、粘接剂(F = 361.165,P<0.001)与喷砂(F = 80.050,P<0.001)可显著影响粘接强度;冷热循环与粘接剂(F = 155.724,P<0.001)、粘接剂与喷砂(F = 3.535,P = 0.002)、冷热循环与喷砂(F = 9.184,P = 0.003)两两因素间分别具有交互作用;冷热循环、粘接剂与喷砂三因素间具有交互作用(F = 12.392,P<0.001)。 结论(1)喷砂有助于改善通用型粘接剂对复合树脂与PEEK 37 ℃恒温水浴24 h粘接强度;(2)复合树脂与PEEK粘接强度在冷热循环3000次后显著降低;(3)本实验中PBU组粘接耐久性优于其他粘接系统。  相似文献   
4.
PurposeTo test the following hypotheses: (a) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms, and (b) CPD correlates to ostium area (OA) and aneurysm volume (AV).Materials and MethodsThis retrospective study included 60 aneurysms (54 ruptured and 6 unruptured) treated with simple coiling (SC) (n = 18), balloon-assisted coiling (BAC) (n = 7), or stent-assisted coiling (SAC) (n = 35) at the authors’ institution between August 2017 and December 2019. AV and OA measurements were obtained from 3-dimensional digital subtraction angiography images using commercial software. Coil sizes were retrieved from patient files, and coil volume (CV) measurements were obtained from https://www.angiocalc.com/. Analysis of covariance, multivariate covariance analysis, and Pearson correlation analyses were performed.ResultsThe median value for AV, CV, CPD, and OA was 63.4 mm3 (range, 5.5–1,771.4 mm3), 23.13 mm3 (range, 2.03–296.95 mm3), 33.29% (range, 13.41%–81.02%), and 10.7 mm2 (range, 2.7–49.9 mm2), respectively. Multivariate analysis showed that the CPD values were not significantly different among the treatment groups, although OA significantly differed between the SC and SAC groups (P < .05). Pearson correlations showed that similar to AV, OA was negatively correlated with CPD (r = ?0.321, P < .05).ConclusionsThe CPD value in cerebral aneurysms treated with BAC or SAC did not differ from that in aneurysms treated with SC.  相似文献   
5.
BackgroundRepairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors’ objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival.MethodsRecords of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event.ResultsDuring the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam.ConclusionsMedian survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively.Practical ImplicationsWhen considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.  相似文献   
6.
Mass characteristic frequency (fmass) is a novel shear wave (SW) parameter that represents the ratio of the averaged minimum SW speed within the regions of interest to the largest dimension of the mass. Our study objective was to evaluate if the addition of fmass to conventional 2-D shear wave elastography (SWE) parameters would improve the differentiation of benign from malignant thyroid nodules. Our cohort comprised 107 patients with 113 thyroid nodules, of which 67 (59%) were malignant. Two-dimensional SWE data were obtained using the Supersonic Imagine Aixplorer ultrasound system equipped with a 44- to 15-MHz15-MHz linear array transducer. A receiver operating characteristic curve was generated based on a multivariable logistic regression analysis to evaluate the ability of SWE parameters with/without fmass and with/without clinical factors to discriminate benign from malignant thyroid nodules. The addition of fmass to conventional SW elasticity parameters increased the area under the curve from 0.808 to 0.871 (p = 0.02). The combination of SW elasticity parameters plus fmass plus clinical factors provided the strongest thyroid nodule malignancy probability estimate, with a sensitivity of 93.4% and specificity of 91.1% at the optimal threshold. In summary, fmass can be a valuable addition to conventional 2-D SWE parameters.  相似文献   
7.
8.
目的 优选清热除湿止痛液的提取工艺。方法 在单因素考察的基础上,以信息熵理论结合星点设计-效应面法,对浸泡时间、提取时间、加水量及提取次数进行考察,以绿原酸、龙胆苦苷、络石苷的含量及干膏得率为评价指标,采用信息熵理论对各评价指标赋予权重系数,并计算综合评分。通过Design-Expert 8.0.6.1软件分析各因素间的交互作用,得出优化的水提取工艺,并对该工艺进行验证实验。结果 依据信息熵理论,将绿原酸、龙胆苦苷、络石苷及干膏得率的权重系数分别确定为0.16、0.76、0.05、0.03;交互作用分析结果显示,浸泡时间对综合评分影响较大。清热除湿止痛液的最佳提取工艺确定为浸泡53 min,加9倍量水,提取3次,每次105 min;验证结果显示,各指标成分含量及综合评分RSD均小于3%。结论 优化的水提取工艺稳定、可行,可为清热除湿止痛液的进一步开发利用提供参考。  相似文献   
9.
The stress-based finite element method is proposed to solve the static bending problem for the Euler–Bernoulli and Timoshenko models of an elastic beam. Two types of elements—with five and six degrees of freedom—are proposed. The elaborated elements reproduce the exact solution in the case of the piece-wise constant distributed loading. The proposed elements do not exhibit the shear locking phenomenon for the Timoshenko model. The influence of an elastic foundation of the Winkler type is also taken into consideration. The foundation response is approximated by the piece-wise constant and piece-wise linear functions in the cases of the five-degrees-of-freedom and six-degrees-of-freedom elements, respectively. An a posteriori estimation of the approximate solution error is found using the hypercircle method with the addition of the standard displacement-based finite element solution.  相似文献   
10.
When a new treatment regimen is expected to have comparable or slightly worse efficacy to that of the control regimen but has benefits in other domains such as safety and tolerability, a noninferiority (NI) trial may be appropriate but is fraught with difficulty in justifying an acceptable NI margin that is based on both clinical and statistical input. To overcome this, we propose to utilize composite risk‐benefit outcomes that combine elements from domains of importance (eg, efficacy, safety, and tolerability). The composite outcome itself may be analyzed using a superiority framework, or it can be used as a tool at the design stage of a NI trial for selecting an NI margin for efficacy that balances changes in risks and benefits. In the latter case, the choice of NI margin may be based on a novel quantity called the maximum allowable decrease in efficacy (MADE), defined as the marginal difference in efficacy between arms that would yield a null treatment effect for the composite outcome given an assumed distribution for the composite outcome. We observe that MADE: (1) is larger when the safety improvement for the experimental arm is larger, (2) depends on the association between the efficacy and safety outcomes, and (3) depends on the control arm efficacy rate. We use a numerical example for power comparisons between a superiority test for the composite outcome vs a noninferiority test for efficacy using the MADE as the NI margin, and apply the methods to a TB treatment trial.  相似文献   
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