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31.
In this paper, eight variables of cement, blast furnace slag, fly ash, water, superplasticizer, coarse aggregate, fine aggregate and flow are used as network input and slump is used as network output to construct a back-propagation (BP) neural network. On this basis, the learning rate, momentum factor, number of hidden nodes and number of iterations are used as hyperparameters to construct 2-layer and 3-layer neural networks respectively. Finally, the response surface method (RSM) is used to optimize the parameters of the network model obtained previously. The results show that the network model with parameters obtained by the response surface method (RSM) has a better coefficient of determination for the test set than the model before optimization, and the optimized model has higher prediction accuracy. At the same time, the model is used to evaluate the influencing factors of each variable on slump. The results show that flow, water, coarse aggregate and fine aggregate are the four main influencing factors, and the maximum influencing factor of flow is 0.875. This also provides a new idea for quickly and effectively adjusting the parameters of the neural network model to improve the prediction accuracy of concrete slump.  相似文献   
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Purpose of ReviewThe role of the meniscus in preserving the biomechanical function of the knee joint has been clearly defined. The hypothesis that meniscus root integrity is a prerequisite for meniscus function is supported by the development of progressive knee osteoarthritis (OA) following meniscus root tears (MRTs) treated either non-operatively or with meniscectomy. Consequently, there has been a resurgence of interest in the diagnosis and treatment of MRTs. This review examines the contemporary literature surrounding the natural history, clinical presentation, evaluation, preferred surgical repair technique and outcomes.Recent FindingsSurgeons must have a high index of suspicion in order to diagnose a MRT because of the nonspecific clinical presentation and difficult visualization on imaging. Compared with medial MRTs that commonly occur in middle age/older patients, lateral meniscus root injuries tend to occur in younger males with lower BMIs, less cartilage degeneration, and with concomitant ligament injury. Subchondral insufficiency fractures of the knee have been found to be associated with both MRTs and following arthroscopic procedures. Meniscus root repair has demonstrated good outcomes, and acute injuries with intact cartilage should be repaired. Cartilage degeneration, BMI, and malalignment are important considerations when choosing surgical candidates. Meniscus centralization has emerged as a viable adjunct strategy aimed at correcting meniscus extrusion.SummaryMeniscus root repair results in a decreased rate of OA and arthroplasty and is economically advantageous when compared with nonoperative treatment and partial meniscectomy. The transtibial pull-through technique with the addition of centralization for the medial meniscus is associated with encouraging early results.  相似文献   
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目的 研究瑶药野柠檬根的挥发性成分.方法 采用水蒸气蒸馏法提取野柠檬根的挥发油,并用GC-MS进行测定,结合计算机检索技术对分离的化合物进行结构检索,应用色谱面积归一化法计算各成分的相对含量.结果 从野柠檬根挥发油中分离并检索出37种化学成分,其中相对百分含量大于3%的分别确定为α-法呢烯、榄香醇、β-马啊里烯、β-桉叶醇、Tticyclo[2.2.1.0(2,6)]heptane,1,7-demethyl-7- (4-methyl -3-pentenyl).结论 该植物中37个挥发性成分均为首次报道,占挥发油气化产物的91%.  相似文献   
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目的探讨不同加力方式对牙齿移动速度的影响以及与龈沟液核因子κB受体活化子配体/骨保护素表达比值(RANKL/OPG)的相关性。方法选取双侧对称拔除4颗第一双尖牙的恒牙列患者,随机分为螺旋弹簧施力组和弹力橡皮链施力组,实施尖牙远中移动,分别于加力前,加力2、4、8、12、16、20周测量尖牙移动量和龈沟液RANKL/OPG值。结果加力4周后,螺旋弹簧组每个时间点的尖牙移动量均大于橡皮链组。两组各加力时间点的RANKL/OPG值均有显著差异。尖牙移动到位后和稳定3个月后的定位根尖片均无牙根吸收现象。结论螺旋弹簧组的骨改建作用强于橡皮链组,龈沟液RANKL/OPG值与骨改建过程具有相关性。  相似文献   
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BackgroundParticulate matter (PM) is an air pollutant that can impair the human skin. Antioxidants have been tested to improve PM-induced skin inflammation.ObjectiveIn this study, we investigated the effects of dieckol on PM-induced inflammation on cultured human sebocytes, outer root sheath (ORS) cells, and mice pretreated with Cutibacterium acnes.MethodsWe cultured and treated the sebocytes and ORS cells with 5 µM of dieckol and 100 µg/ml of PM10 for 24 h. The C. acnes-pretreated mice received 5 µM of dieckol and 100 µg/ml of PM10. We measured cell viability using MTT assay. Real-time PCR and measurement of reactive oxygen species (ROS) and sebum production analyzed the effects.ResultsDieckol inhibited the upregulation of the gene expression of the inflammatory cytokines, matrix metalloproteinase (MMP), aryl hydrocarbon receptor, and nuclear factor kappa-light-chain-enhancer of activated B cells by PM10 in the cultured sebocytes and ORS cells and inhibited an increase in ROS production by PM10 in the cultured sebocytes. In addition, dieckol decreased the inflammatory cytokines, MMP, and sebum production in C. acnes-pretreated mice.ConclusionDieckol effectively reduced the expression of inflammatory biomarkers and the production of sebum in cultured sebocytes, ORS cells, and C. acnes-pretreated mice.  相似文献   
38.
农晨 《医学文选》2002,21(4):443-444
目的 观察超声波根管治疗对弯曲细小、堵塞根管的疗效并作出分析。方法 选择病例 (共32 0颗患牙 )分为实验组 ( 1 68颗 )和对照组 ( 1 5 2颗 )分别采用超声波和手用器械的方法制备根管 ,消毒 ,封药 ,然后根充 ,拍 X片。结果 经半年的观察 ,实验组的成功率为 95 % ,对照组为 5 7% ,两组明显差异 ( P <0 .0 5 )。结论 超声波根管预备与传统的手用器械法相比具有明显的优点 ,值得推广 ,但注意操作规范。  相似文献   
39.
何首乌提取物对人乳腺癌细胞脂肪酸合酶的抑制研究   总被引:2,自引:0,他引:2  
目的 研究何首乌提取物对人乳腺癌MCF7细胞脂肪酸合酶(fatty acid synthase,FAS)的抑制作用。方法 MTT法测定人乳腺癌MCF7细胞增殖速度,采用超速离心技术部分纯化人乳腺癌MCF7细胞FAS。不同浓度何首乌提取物与FAS相互作用不同时间后,加入底物,用分光光度法观察何首鸟提取物对FAS的抑制作用。结果 何首鸟提取物对人乳腺癌MCF7细胞的增殖有一定的抑制作用。人乳腺癌MCF7细胞FAS被部分纯化,三种浓度何首乌提取物(0.1,0.5,1g/L)与FAS在催化前相互作用0、5和10min,对FAS活性的抑制率分别为24.60%、27.30%、and42.75%(0.1g/L);43.50%、50.30%、and94.03%(O.5g/L);98.60%、97.30% and97.05%(1g/L)。结论 何首乌提取物对人乳腺癌MCF7细胞FAS具有抑制作用;作用强度既依赖于抑制剂浓度,又依赖于抑制剂与酶相互作用时间。  相似文献   
40.
Sixteen one-year-old dogs were used in our experiment.We rotated the maxillary secondincisors of the dogs,applying a force of 100g and a moment of 550g·mm.The duration of theexperiment varied from 72h to 8 weeks.Activation was performed once every 2 weeks and the impressions were taken in order to measure the angles of rotation.The results of our experiment showthat the rotation rate of single-rooted tooth in dogs is 3.04/week.The graph shows the form ofgradual stairs.This paper introduces a new specialized experimental apparatus for tooth rotation.The angles of rotation are measured geometrically.  相似文献   
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