期刊文献+
共找到57,946篇文章
< 1 2 250 >
每页显示 20 50 100
Fracture strength of custom-fabricated Celay all-ceramic post and core restored endodontically treated teeth 被引量:1
1
作者 ZHANG Yu-xing ZHANG Wei-hong LU Zhi-yue WANG Ke-li 《Chinese Medical Journal》 SCIE CAS CSCD 2006年第21期1815-1820,共6页
Background The increased use of all-ceramic crown provides a rationale for tooth-colored core. Due to superior mechanical properties, Vita Celay infiltration ceramic developed for crown and bridge works presents the p... Background The increased use of all-ceramic crown provides a rationale for tooth-colored core. Due to superior mechanical properties, Vita Celay infiltration ceramic developed for crown and bridge works presents the potential for fabricating all-ceramic posts and cores in one piece. This study was conducted to compare the fracture strength of endodontically treated teeth which were thereafter given different types of posts and cores and crowns restoration, respectively. The evaluated post-and-core systems are: custom-fabricated Celay all-ceramic post-core, custom cast metal post-core, and prefabricated stainless steel post (Parapost) with and without 2.0 mm dentine ferrule. Methods Sixty freshly extracted human maxillary central incisors were endodontically treated and randomly divided into five groups with 12 samples each. Group A: Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule. Group B: Celay ceramic post-cores restored teeth with no dentine ferrule. Group C: cast metal post-cores restored teeth with 2.0 mm dentine ferrule. Group D: cast metal post-cores restored teeth with no dentine ferrule. Group E: prefabricated post and composite cores restored teeth with 2.0 mm dentine ferrule. All teeth were restored with Celay ceramic crowns. Each specimen was subjected to a load at a 45-degree angle to the long axis on MTS 810 material testing machine until failure, at crosshead speed of 0.02 cm/minute. Analysis of variance followed by the Newman-Keuls pairwise multiple comparison tests were used to compare the results of the groups tested. Results There was a statistically significant difference among the five groups (P〈0.01). Celay ceramic post-cores restored teeth with 2.0 mm dentine ferrule [(758.35± 119.26) N] and cast metal post-cores restored teeth with 2.0 mm dentine ferrule [(756.63± 166.22) N] had a significantly greater mean fracture strength than the other three groups in which no significant difference was observed. The 2.0 mm dentine ferrule could cause significant fracture resistance alteration of Celay post-core restored teeth. Conclusions When covered with Celay ceramic crowns, Celay post-cores restored teeth with 2.0 mm dentine ferrule and cast metal post-cores restored teeth with 2.0 mm dentine ferrule have similar fracture strength. There was a statistically significant difference between the fracture resistance of Celay post-core restored teeth with and without 2.0 mm dentine ferrule. 展开更多
关键词 fracture strength CERAMICS post and core nonvital tooth
原文传递
Postoperative Complications in the General Surgery Department of the Cs Ref of Commune I of the District of Bamako Mali
2
作者 Tounkara Cheickna Samake Hamidou +7 位作者 Dembele Lamine Diarra Issaka Togola Modibo Sanogo Modibo Dembele Bakary Tientigui Traore Alhassane Togo Adégné Pierre Kante Lassana 《Surgical Science》 2024年第6期409-419,共11页
Postoperative complications represent important indicators for the quality of surgical care. The objectives of this work were to study post-operative complications in the general surgery department of the Cs ref of co... Postoperative complications represent important indicators for the quality of surgical care. The objectives of this work were to study post-operative complications in the general surgery department of the Cs ref of commune I in Mali, to determine the frequency of post-operative complications, to identify the factors of occurrence, to describe the clinical aspects, diagnostic and therapeutic in order to assess the additional cost linked to post-operative complications. This study was prospective, carried out in the general surgery department on 300 cases of surgical interventions. It covered all patients aged at least 15 years, operated on and hospitalized or not, and who presented complications during the 30 days postoperatively. Patients under the age of 15 were not included (our general surgery department is not a pediatric surgery department). We collected 300 patients among whom 199 (66.33%) were men and 101 (33.66%) women, i.e. a sex ratio = 1.9. The average age was 38 years with extremes of 15 and 87 years. The main initial diagnoses were: acute appendicitis, peritonitis, occlusions, wall hernias, hemorrhoids, uterine prolapse, uterine myomas, ovarian cysts and acute cholecystitis. Emergencies represented 43% (N = 129) of interventions with 6.98% post-operative complications (POC). Postoperative complications were dominated by surgical site infections, 75% of cases (N = 20), wall hemorrhage 5% (N = 1), testicular necrosis 5% (N = 1) and testicular calcification 5% (N = 1), wire rejection 5% (N = 1) and death 5% (N = 1). The management of postoperative complications was surgical in 95% and medical in 100%. Their occurrence extended the hospital stay by 3.65 days and increased the average cost of care by 60541.85 CFA francs. The mortality index lowered by efficient management of complications (IMAGE) calculated in relation to deaths was 95% of cases. Anemia, ASA score ≥ III, Alteimeir II and IV classes, duration of surgery and post-operative hospitalization were factors contributing to post-operative complications. 展开更多
关键词 Complications post Opératoires CHIRURGIE Cs Ref CI BAMAKO MALI
下载PDF
Development of a Post Quantum Encryption Key Generation Algorithm Using Electromagnetic Wave Propagation Theory
3
作者 Vincent Mbonigaba Fulgence Nahayo +1 位作者 Octave Moutsinga Okalas-Ossami Dieudonné 《Journal of Information Security》 2024年第1期53-62,共10页
In today’s rapid widespread of digital technologies into all live aspects to enhance efficiency and productivity on the one hand and on the other hand ensure customer engagement, personal data counterfeiting has beco... In today’s rapid widespread of digital technologies into all live aspects to enhance efficiency and productivity on the one hand and on the other hand ensure customer engagement, personal data counterfeiting has become a major concern for businesses and end-users. One solution to ensure data security is encryption, where keys are central. There is therefore a need to find robusts key generation implementation that is effective, inexpensive and non-invasive for protecting and preventing data counterfeiting. In this paper, we use the theory of electromagnetic wave propagation to generate encryption keys. 展开更多
关键词 KEY Wave ELECTROMAGNETIC CRYPTOGRAPHY post Quantum Network Protocol Propagation ALGORITHM
下载PDF
Advances in Research of Post Embolism Syndrome after Transarterial Chemoembolization(TACE)for Hepatocellular Carcinoma
4
作者 Jimusi Sarengerile 《Medicinal Plant》 2024年第2期77-79,共3页
This article reviews the concept and clinical manifestations of post embolism syndrome after transarterial chemoembolization(TACE),and the prevention or timely intervention of post embolism syndrome in advance is expe... This article reviews the concept and clinical manifestations of post embolism syndrome after transarterial chemoembolization(TACE),and the prevention or timely intervention of post embolism syndrome in advance is expected to reduce its incidence and degree in clinical treatment,and to improve the quality of treatment of Hepatocellular Carcinoma Carcinoma(HCC). 展开更多
关键词 Hepatocellular Carcinoma(HCC) Transarterial chemoembolization(TACE) post embolism syndrome(PES)
下载PDF
Research Progress in the Treatment of Poststroke Depression with Traditional Chinese Medicine
5
作者 Jianguo Duan Yuan Ding Yating Shao 《Research and Inheritance of Traditional Chinese Medicine》 2024年第1期33-37,共5页
In recent years,the incidence rate of stroke has increased year by year.Post stroke depres‐sion is one of its main complications,which seriously affects the recovery of physiological functions and quality of life of ... In recent years,the incidence rate of stroke has increased year by year.Post stroke depres‐sion is one of its main complications,which seriously affects the recovery of physiological functions and quality of life of stroke patients.Traditional Chinese medicine has signifi‐cant therapeutic effects in treating this disease.This article provides a classification and review of traditional Chinese medicine treatment methods for post-stroke depression,and looks forward to the current problems. 展开更多
关键词 traditional Chinese medicine post stroke depression research progress
下载PDF
The Model of“Post,Course,Competition,Certificate”Integrated Education for Electronic Information Engineering Technology Major in Higher Vocational Colleges
6
作者 Qinqin Jing Yun Liu Xinyu Zheng 《Journal of Contemporary Educational Research》 2024年第5期223-229,共7页
The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent trainin... The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent training,higher vocational colleges need to pay attention to establishing an all-round and three-dimensional education model,and promote innovation of higher vocational education on the basis of this.It is also a way to promote the innovation of higher vocational education to vigorously promote the construction of“post,course,competition,certificate”mode in the construction of education mode.Through the construction of“post,course,competition,certificate”mode,the education mode of higher vocational colleges is gradually improved,so as to strengthen the effectiveness of talent training in higher vocational colleges.Therefore,in this paper,the author puts forward some suggestions to promote the construction of the integrated education mode of the electronic information engineering technology major in higher vocational colleges,so as to help improve the talent training level of higher vocational colleges. 展开更多
关键词 Higher vocational education Electronic information engineering technology major post course competition certificate” Integrated education model
下载PDF
Effects of Pearl Yangxin Anshen Decoction on HAMD and PTSD-SS Scores, Cytokines and Related Metabolites in Patients with Post-Traumatic Stress Disorder
7
作者 Yu Feng Min Guo 《Journal of Behavioral and Brain Science》 2024年第3期93-102,共10页
Objective: This paper aims to observe the Pearl Yangxin Anshen Decoction to influence the score of HAMD and PTSD-SS, the changes of the cytokines and the related metabolic product in patients with PTSD. Methods: From ... Objective: This paper aims to observe the Pearl Yangxin Anshen Decoction to influence the score of HAMD and PTSD-SS, the changes of the cytokines and the related metabolic product in patients with PTSD. Methods: From June 2015 to May 2016, in the traditional Chinese medicine clinics of Hainan Province People’s Hospital, there were 50 patients with PTSD, the age were from 30 to 60, they were randomly divided into treatment group (25 cases) and control group (25 cases), then compared the scores of HAMD and PTSD-SS between the two groups, searched the changes of cytokines and the related metabolic product. Results: In the treatment group: before and after treatment the scores of PTSD-SS were 65.64 ± 7.02, 28.32 ± 4.18, and the scores of HAMD were 29.28 ± 1.97, 11.72 ± 2.13;In the control group: before and after treatment the scores of PTSD-SS were 63.24 ± 6.16, 31.40 ± 4.29, the scores of HAMD were 30.24 ± 2.05, 13.08 ± 2.30. After 3 months patients in treatment group the scores of PTSD-SS and HAMD were lower than the control group (t = 2.570, P = 0.013, t = -2.1640, P = 0.035). In the control group: before and after 3 months treatment the IL-2 levels respectively were 79.84 ± 26.46 pg/ml, 56.18 ± 22.67 pg/ml, the IL-6 levels respectively were 110.83 ± 47.65 pg/ml, 59.67 ± 44.68 pg/ml, the IL-8 levels respectively were 73.11 ± 78.51 pg/ml, 55.83 ± 81.94 pg/ml, the NE levels respectively were 420.04 ± 674.75 pg/ml, 185.31 ± 417.91 pg/ml, the MDA levels respectively were 112.35 ± 62.87 ng/ml, 60.42.33 ± 53.64 ng/ml, the NO levels were 126.6 ± 47.4 μmol/L, 78.6 ± 45.7 μmol/L, the VIP levels were 396.6 ± 144.4 pg/ml, 122.4 ± 111.5 pg/ml. In the treatment group: before and after 3 months treatment the IL-2 levels respectively were 86.00 ± 32.29 pg/ml, 53.84 ± 27.01 pg/ml, the IL-6 levels respectively were 108.21 ± 44.60 pg/ml, 42.46 ± 42.16 pg/ml, the IL-8 levels respectively were 81.48 ± 94.19 pg/ml, 54.07 ± 84.15 pg/ml, the NE levels respectively were 392.93 ± 592.84 pg/ml, 243.85 ± 588.45 pg/ml, the MDA levels respectively were 117.58 ± 63.37 ng/ml, 45.91 ± 38.94 ng/ml, the NO levels respectively were 135.9 ± 46.4 μmol/L, 72.6 ± 46.6 μmol/L, the VIP levels respectively were 414.0 ± 140.1 pg/ml, 185.8 ± 105.3 pg/ml. In the two groups as the extension of treatment time, the content of IL-2, IL-8, IL-6, NE, MDA, NO, and VIP were gradually reduced, and the level of reduction of the treatment group patients was higher than the control group, the change of ACTH and SOD levels just the opposite. Conclusion: The Pearl Yangxin Anshen Decoction could improve the symptoms of psychological anxiety, depression and other psychological problems in patients with PTSD, and influence the change of cytokines and related metabolites product. 展开更多
关键词 post-Traumatic Stress Disorder Psychological Intervention Serological Detection
下载PDF
Post-Traumatic Stress Disorder among Defence and Security Forces in Northern Benin (2023)
8
作者 Ireti Nethania Elie Ataigba Guy Gérard Aza Gnandji +6 位作者 David Sinet Koivogui Dalmace Fauste Adjaho Eurydice Elvire Djossou Anselme Djidonou Francis Tognon Tchegnonsi Prosper Gandaho Josiane Ezin Houngbe 《Open Journal of Psychiatry》 2024年第2期142-161,共20页
Introduction: Post-traumatic stress disorder (PTSD) is defined as “actual exposure to death or the threat of death, serious injury or sexual violence”, either directly or indirectly, resulting in a symptomatic proce... Introduction: Post-traumatic stress disorder (PTSD) is defined as “actual exposure to death or the threat of death, serious injury or sexual violence”, either directly or indirectly, resulting in a symptomatic procession of repetition, avoidance, neurovegetative hyperactivity and individualized symptoms, with or without negative cognitive and mood changes. It therefore goes without saying that the defence and security forces constitute a high-risk population in need of attention. Objective: To study post-traumatic stress disorder in defence and security forces in the city of Parakou in 2023. Methods: Descriptive cross-sectional study conducted from December 2022 to July 2023. The study population consisted of active military, republican police and firefighters in the city of Parakou in 2023. Non-proportional stratified sampling was used, given the inaccessibility of the source population size for national security reasons. Post-traumatic stress disorder was assessed using the “post-traumatic stress disorder checklist-5 (PCLS-5) scale. Results: A total of 305 subjects participated in the survey. Males dominated 90.2%. The most represented corps was the Republican Police (41.6%), most of whom were non-commissioned officers (46.6%). The majority count between 11 and 20 years of service (48.9%), with 2 to 5 missions completed (67.5%). The calculated prevalence of post-traumatic stress disorder was 11.8%, based on the post-traumatic stress disorder checklist-5 (PCL-5). Of the 36 respondents with post-traumatic stress disorder, 20 (55.6%) had experienced an armed attack, 25 (69.4%) had witnessed a violent death, 18 (50.0%) had witnessed the agony of a colleague, 15 (41.7%) had been exposed to a fire or explosion, while 26 (72.2%) had been traumatized by physical and/or verbal aggression. 5 (13.9%) had consulted a specialist psychiatrist, while 6 (16.7%) were on medication and 26 (72.2%) used sport as a means of maintaining physical and mental health. Respectively 22 (61.1%) and 21 (58.3%) had definite symptoms of anxiety and depression. Multivariate analysis revealed a significant association between post-traumatic stress disorder and the following variables: total number of children ≤ 2 (p = 0.015), comorbidities such as arterial hypertension (p = 0.007), history of hepatitis (p = 0.017), work accidents (p = 0.016), alcohol dependence (p = 0.004), domestic violence (p = 0.004), psychological violence (p = 0.017) and anxiety disorders (p Conclusion: Defence and security personnel can also be prey to post-traumatic stress disorder (PTSD), which needs to be systematically taken into account when they are subjected to trauma in the course of their duties. Mental health should be an integral part of the periodic medical check-up objectives for defence and security forces throughout the country. 展开更多
关键词 post-Traumatic Stress Disorder FORCES DEFENCE SECURITY BENIN 2023
下载PDF
Correlation Study of Neurotransmitter and Immune Levels in Pre-Hospital Emergency Nurses with Post-Traumatic Stress Disorder
9
作者 Yanling Zhou Min Guo +1 位作者 Xiangling Jiang Long Li 《Journal of Behavioral and Brain Science》 2024年第1期12-22,共11页
Objective: To investigate the occurrence of PTSD in pre-hospital emergency nurses and its related factors, and to compare the differences of neurotransmitter and immune-related factors between pre-hospital emergency n... Objective: To investigate the occurrence of PTSD in pre-hospital emergency nurses and its related factors, and to compare the differences of neurotransmitter and immune-related factors between pre-hospital emergency nurses who experienced traumatic events and those who did not develop PTSD and healthy people. How: Post-traumatic Stress Disorder Self-Rating Scale (PCL-C) tests were performed on pre-hospital emergency nurses in PTSD group, non-PTSD group and healthy control group, and the plasma monoamine neurotransmitters and serum cytokines were determined by double-antibody sandwich ABC-ELISA assay using enzyme-linked adsorption kit provided by Shanghai Xitang Biotechnology Co., Ltd. Results: 1) There were statistically significant differences in PCL-C scores between PTSD group, non-PTSD group and healthy group (p α between PTSD group, non-PTSD group and healthy group (p Conclusion: Pre-hospital emergency nurses should have early psychological intervention and guidance to reduce the occurrence of PTSD in emergency and emergency nurses. 展开更多
关键词 Pre-Hospital First Aid NURSE post-Traumatic Stress Disorder NEUROIMMUNOLOGY
下载PDF
Evaluation of Clinical Characteristics and Plasma Cortisol Concentrations in Individuals with COVID-19 and Post-COVID Syndrome
10
作者 David Alejandro García López Stephania Ramos Hernández +4 位作者 Yamile López-Hernández María Argelia López Luna Elena Donaji Ramírez Alvarado Rosa María Ramírez Santoyo Sergio Hugo Sánchez Rodríguez 《Case Reports in Clinical Medicine》 2024年第1期12-24,共13页
COVID-19 generates systematic alterations in humans both in active stages of infection and over time, called post-COVID syndrome. Cortisol is a hormone that is overexpressed in inflammation and cellular stress process... COVID-19 generates systematic alterations in humans both in active stages of infection and over time, called post-COVID syndrome. Cortisol is a hormone that is overexpressed in inflammation and cellular stress processes. Its main function is to return to physiological homeostasis, so its evaluation together with other clinical parameters can allow us to determine the degree of systemic affectation by COVID-19. Objective: To evaluate changes in clinical parameters and plasma cortisol concentrations in patients with active COVID-19 and post-COVID syndrome. Material and Methods: Healthy patients, in stages of mild infection, critical and with post-COVID syndrome, were recruited, obtaining, through clinical diagnoses and interviews, their main clinical characteristics, in addition to plasma, in which cortisol concentrations were determined using competitive ELISA. Results: The critical stage group had higher frequencies of comorbidities, clinical symptoms, as well as more altered laboratory parameters compared to the other subgroups. In the post-COVID syndrome group after the initial infection, most laboratory parameters recovered, however, several clinical symptoms remained latent over time. The determination of cortisol showed an increase in its concentration, being higher in patients in critical stage and with post-COVID syndrome. Conclusion: COVID-19 disease generates clinical alterations that trigger an increase in plasma cortisol. These alterations increase as the stages of infection become more severe and some of them remain altered in patients with post-COVID syndrome. 展开更多
关键词 COVID-19 CORTISOL post-COVID Syndrome
下载PDF
Body Contour in the Post-Bariatric Male Patient
11
作者 Erick Zúñiga-Garza Israel Salgado-Adame +3 位作者 Claudio D. Rojas-Gutiérrez Laura María Rodríguez-Barrios Guillermo Álvarez-Sánchez Eduardo Camacho-Quintero 《Modern Plastic Surgery》 2024年第2期15-22,共8页
Background: Obesity is currently considered a public health problem. Bariatric procedures have become an important part of obesity management and, consequently, the number of male patients seeking post-bariatric recon... Background: Obesity is currently considered a public health problem. Bariatric procedures have become an important part of obesity management and, consequently, the number of male patients seeking post-bariatric reconstructive procedures have increased. Therefore, the clinical approach and understanding of the body contour of this population have become more relevant. The goal of post-bariatric reconstruction is to enhance the male silhouette through removal of skin and adipose tissue excess, and abdominal rectus diastasis repair. Material and Methods: We conducted a retrospective study at the Plastic and Reconstructive Surgery Department of the National Medical Center “20 de Noviembre”. All male patients referred to our department to start a post-bariatric reconstruction protocol from January 2018 to December 2022 were included in this study. Results: In total, 15 patients who underwent corporal contouring procedures were included;median age was 49.2 years with minimum of 33 years, and a maximum of 57 years. Median Body mass index was 28.4 kg/m<sup>2</sup> with minimum of 22 kg/m<sup>2</sup> and maximum of 38 kg/m<sup>2</sup>. All patients were treated 18 months after their bariatric surgery. All patients underwent an abdominoplasty as a body contouring procedure. 4 (26.7%) patients presented complications related to the surgery. Conclusion: We described a comprehensive and systematic approach to massive weight loss for male patients, suggesting an abdominal marking based on the patient’s clinical features and the expected results avoiding feminization of the abdominal body contour. 展开更多
关键词 Massive Weight Loss post-Bariatric MALE ABDOMINOPLASTY CONTOURING
下载PDF
Influence of Abutment Material on the Stress of Implant-supported All-ceramic Single Crown 被引量:2
12
作者 高少怀 DUAN Haiying 李智勇 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第1期96-99,共4页
In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown, a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M... In order to investigate the influence of abutment material on the stress of implant-supported all-ceramic single crown, a 3D finite element model of implant-supported mandibular first premolar was computed by COSMOS/M 2.85 software. Alumina, zirconia, and titanium were used as abutment materials respectively. Vertical 600 N and horizontal 225 N load was applied on the occlusal surface. The results show that the stress distribution of implant-supported single crown was similar for different abutment materials. Maximum stresses within the crown were higher when titanium abutment was used. Maximum stress of titanium abutment was lower than that of ceramic abutment. Within the screw and fixture, maximum stresses had no difference under vertical loading but higher as titanium abutment was used under horizontal loading. There was no difference of maximum stress within the bone when different abutment materials were used. The present findings indicate that the abutment material had no influence on the stress distribution of implant-supported all- ceramic single crown but maximum stress when the titanium abutment was lower than that of ceramic abutment. 展开更多
关键词 finite element analysis dental implant STRESS all-ceramic ABUTMENT
下载PDF
基于IMSpost下的叶轮加工五轴后处理研究与实践
13
作者 熊运星 闫国琛 《无线互联科技》 2023年第20期117-121,共5页
五轴加工工艺不断发展的背景下,机床的后处理定制将成为核心技术之一。文章以VMC-300小型五轴机床开展五轴后处理加工研究,并以开式叶轮进行了五轴加工的工艺分析。文章分析了工装设计、加工路线等。该机床下的工艺仿真及加工验证,解决... 五轴加工工艺不断发展的背景下,机床的后处理定制将成为核心技术之一。文章以VMC-300小型五轴机床开展五轴后处理加工研究,并以开式叶轮进行了五轴加工的工艺分析。文章分析了工装设计、加工路线等。该机床下的工艺仿真及加工验证,解决无碰撞、过切、少切等问题。本研究提高了五轴数控加工的效率和质量,为同类产品的加工及工艺提供参考。 展开更多
关键词 后处理 叶轮 过切
下载PDF
Influence of Different Luting Agents on the Stress Distributions of Implant-supported All-ceramic Single Crown
14
作者 GAO Shaohuai WANG Min +2 位作者 DUAN Haiying LI Qing LI Zhiyong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第6期1227-1230,共4页
The purpose of this study was to investigate the influence of different luting agents on the stress distribution within the crown, abutment and peri-implant bone of implant-supported all-ceramic single crown. A three-... The purpose of this study was to investigate the influence of different luting agents on the stress distribution within the crown, abutment and peri-implant bone of implant-supported all-ceramic single crown. A three-dimensional finite element model of an implant-supported single crown for the first premolar of mandible was created by COSMOS 2.85. Resin-modified glass ionomer and two different resin adhesives were used to cement the crown and abutment. Vertical 600 N and horizontal 225 N loads were applied to stimulate the condition of chewing. The stress distributions within the all-ceramic crown, abutment and peri-implant bone were analyzed. The experimental results show that the stress distributions of all-ceramic crown, abutment, implant and peri-implant bone were similar when different luting agents were used. The result of present study indicated that luting agents had no influence on the stress distributions of implant-supported all-ceramic single crown. 展开更多
关键词 stress distributions dental implants luting agent all-ceramic
下载PDF
The Effect of Alumina Content on Fracture Property of All-ceramics Zirconia
15
作者 张东姣 LIAO Yunmao +4 位作者 LI Aijie1 XU Zujie SONG Dawei WANG Qi 陈新民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第1期73-78,共6页
The purpose of the present study was to evaluate the effect ofA1203 content on the fracture property of all-ceramics ZrO2. To improve the all-ceramics ZrO2 restoration mechanics properity ,96 samples containing 0,5,10... The purpose of the present study was to evaluate the effect ofA1203 content on the fracture property of all-ceramics ZrO2. To improve the all-ceramics ZrO2 restoration mechanics properity ,96 samples containing 0,5,10 and 15 wt% of A1203 particles were prepared by cold isostatic pressing (200 MPa) and 1 550 ℃ sintered .The phase was analyzed by X-ray diffraction analysis and the bulk densities of the samples were made using Archimedes principle. Samples were randomly divided into four groups. In each group, 24 specimens were prepared so that the angle between notch and specimen's long axis is 90° and 60°. Notch depths were 1 mm for all samples. Samples were loaded with three-point bending method. 90° cut samples were used to measure fracture toughness while 60°cut samples were used to observe fracture curve by taking points on the fracture extension path under microscope, plotting points on coordinates, generating fitting curve by software "Origin", and analyzing the microstructure of the specimen fracture surfaces by scanning electron microscopy (SEM).The results show that the increment ofA1203 has insignificant effect on the densification of all-ceramic ZrO2.XRD analysis shows that the specimen is comprised of t-ZrO2 and a- A1203 before fracture while fracture surface is m-ZrO2, t-ZrO2 and a-A1203. ZrO2 containing 10% A1203 has the optimum mechanical properties and unconspicuous crack propagation and distribution. The observations may provide a reference for the materials selection, shaoe design, and production orocess of all-ceramic crown and bridge. 展开更多
关键词 ZRO2 A1203 all-ceramics NOTCH fracture load fracture curve microstructure
下载PDF
基于UG POST的卧式双工位四轴加工中心后处理定制 被引量:1
16
作者 王钧 李玮 +3 位作者 李小鹏 郭志伟 魏新宇 刘斌 《机床与液压》 北大核心 2023年第17期81-88,共8页
为了解决卧式四轴加工中心四轴联动插补困难、因为结构问题导致的旋转轴锁死位移变动、回原点旋转碰撞、加工中停止碰撞等问题,通过实践积累和对后处理的研究,基于UG POST软件和沈阳机床厂生产的TH6350卧式加工中心,以TCL语言为开发环境... 为了解决卧式四轴加工中心四轴联动插补困难、因为结构问题导致的旋转轴锁死位移变动、回原点旋转碰撞、加工中停止碰撞等问题,通过实践积累和对后处理的研究,基于UG POST软件和沈阳机床厂生产的TH6350卧式加工中心,以TCL语言为开发环境,进行全方位后处理定制,解决了上述问题,详细叙述了此类后处理在构造中的关键问题,公开了核心的算法程序。最后通过实际加工大力神杯验证该后处理的可行性、整体性、稳定性,为双工位卧式加工中心后处理定制方案和加工工艺提供参考。 展开更多
关键词 后置处理 卧式加工中心 四轴联动
下载PDF
Insightful Understanding of the Role of the Mechanical Properties in Defining the Reliability of All-Ceramic Dental Restorations: A Review
17
作者 Mohammad Albakry 《Journal of Biomaterials and Nanobiotechnology》 2021年第4期57-78,共22页
Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlay... Since the last two decades, restorative dentistry has been witnessing an increased acceptance of the use of the well-known all-ceramic materials for the fabrication of single dental restorations, such as inlays, onlays, crowns, anterior and posterior fixed partial dentures (PFPDs). These restorations certainly offer the potential for better biocompatibility coupled with superior aesthetic qualities, especially when compared with the conventional prostheses made from porcelain that is fused with metal ceramic restorations. However, brittleness and extreme sensitivity of all-ceramic materials to micro-like defects or cracks that are inherently present, or may grow, in their microstructure during different laboratory fabrication steps, during necessary clinical adjustments, or from post-placement chewing activity, remain major shortcomings of these dental restorations. In fact, many researchers are of the opinion that the improved mechanical properties can significantly improve the lifetime of all-ceramic restorations and result in enhanced reliability. Therefore, efforts of researchers, as well as manufacturers, have been directed towards the improvement of the mechanical properties in order to overcome such limitations. This article reviews the characterization of the most important mechanical properties that can delineate the behavior of all-ceramic dental materials upon loading. These include fracture mechanics, the brittle nature of ceramics, the relationship between microstructural features and fracture behavior, sources of cracks and flaws that may initiate a fracture and the effect of different fabrication procedures and/or clinical adjustments on the mechanical behavior of dental ceramics are also reviewed and discussed. 展开更多
关键词 Mechanical Properties Fracture Mechanics all-ceramic Dental Restorations Microstructural Features MICROCRACKS
下载PDF
基于NX/Post Builder的UDE功能定制和优化Sinumerik840D螺纹加工程序的后处理研究 被引量:1
18
作者 郑浩 周淑容 《模具制造》 2023年第7期56-58,62,共4页
由于NX攻丝循环参数对话框存在循环参数缺失的情况,从而导致后置处理的NC代码出错,无法加工螺纹。针对此情况,对循环参数缺失的原因进行了分析,通过NX后处理构造器的UDE功能优化和定制了螺纹循环参数,并通过后处理验证了NC代码的正确性... 由于NX攻丝循环参数对话框存在循环参数缺失的情况,从而导致后置处理的NC代码出错,无法加工螺纹。针对此情况,对循环参数缺失的原因进行了分析,通过NX后处理构造器的UDE功能优化和定制了螺纹循环参数,并通过后处理验证了NC代码的正确性和可行性。 展开更多
关键词 NX 后处理 螺纹循环 UDE
下载PDF
Emerging peril of post-dengue mucormycosis:A case report
19
作者 Neha Verma Neelima Gupta +1 位作者 Vashi Gupta Smita Nath 《Journal of Acute Disease》 2023年第1期35-38,共4页
Rationale:Dengue fever is a leading cause of death in tropical and subtropical countries.Although most patients have a self-limited febrile illness,the viral infection can induce virus-mediated host changes,making imm... Rationale:Dengue fever is a leading cause of death in tropical and subtropical countries.Although most patients have a self-limited febrile illness,the viral infection can induce virus-mediated host changes,making immunocompetent persons susceptible to deadly fungal infections.However,there are only a few reports of such an association.Here we present a case of this deadly co-infection.Patient’s Concern:A 17-year-old male patient was diagnosed with dengue fever.He presented to us with facial swelling,periorbital edema,and black discoloration over the palate during the second week of his illness.Diagnosis:Diagnostic tests confirmed the presence of fungal hyphae.A diagnosis of post-dengue mucormycosis was made.No other comorbidity or underlying immune deficit was detected.Interventions:The patient underwent surgical debridement and antifungal treatment.Outcomes:The patient recovered and showed signs of palatal healing with an advancing mucosal edge.Lessons:Dengue virus and mucor co-infection has brought to light a new pathogenic paradigm.Clinicians need to be aware of this emerging medical condition and maintain a high index of suspicion for mucor co-infections while treating dengue patients. 展开更多
关键词 Dengue virus MUCORMYCOSIS DENV post-dengue mucormycosis post dengue mucor
下载PDF
The contribution of steel wallposts to out-of-plane behavior of non-structural masonry walls
20
作者 Fooad Karimi Ghaleh Jough 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第1期243-262,共20页
For years,non-structural masonry walls have received little attention by code developers and professional engineers.Recently,significant efforts have been made to shed more light on out-of-plane(OOP)behavior of non-st... For years,non-structural masonry walls have received little attention by code developers and professional engineers.Recently,significant efforts have been made to shed more light on out-of-plane(OOP)behavior of non-structural masonry walls.In updated provisions of the Iranian seismic code,bed joint reinforcements(BJRs)and steel wallposts have been suggested for use.BJRs are horizontal reinforcements;steel wallposts are vertical truss-like elements intended to provide additional OOP restraints for a wall.The contribution of BJRs has previously been investigated by the authors.This study is devoted to investigating the contribution of steel wallposts to the OOP behavior of non-structural masonry walls.Using pre-validated 3D finite element(FE)models,the OOP behavior of 180 non-structural masonry walls with varying configurations and details are investigated.The OOP pressure-displacement curve,ultimate strength,the response modification factor,and the cracking pattern are among the results presented in this study.It is found that steel wallposts,especially those with higher rigidity,can improve the OOP strength of the walls.The contribution of wallposts in the case of shorter length walls and walls with an opening are more pronounced.Results also indicate that masonry walls with wallpost generally have smaller modification factors compared to similar walls without wallpost. 展开更多
关键词 masonry wall wallpost wind post bed joint reinforcement non-structural masonry wall out-of-plane behavior
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部