期刊文献+
共找到158,037篇文章
< 1 2 250 >
每页显示 20 50 100
High complex anal fistula managed by the modified transanal opening of the intersphincteric space via the inter-sphincteric approach:A case report
1
作者 Ya-Qun Wang Yan Wang +2 位作者 Xiao-Feng Jia Qiao-Jing Yan Xue-Ping Zheng 《World Journal of Radiology》 2024年第10期552-560,共9页
BACKGROUND High complex anal fistulas are epithelialized tunnels,with the main fistula piercing above the deep external sphincter and the internal opening approaching the dentate line.Conventional surgical procedures ... BACKGROUND High complex anal fistulas are epithelialized tunnels,with the main fistula piercing above the deep external sphincter and the internal opening approaching the dentate line.Conventional surgical procedures for high complex anal fistulas remove most of the external sphincter and damage the anorectal ring.Postoperative loss of anal function can cause physical and mental damage.Transanal opening of the intersphincteric space(TROPIS)is an effective procedure that completely preserves the external anal sphincter.However,its clinical application is limited by challenges in the localization of the internal opening of a fistula and the high risk of complications.On the basis of our clinical experience,we modified the TROPIS procedure for the treatment of treating high complex anal fistulas.CASE SUMMARY A patient with a high complex anal fistula located above the anorectal ring underwent modified TROPIS,which involved sepsis drainage and identification of the internal opening in the intersphincteric space.The patient with the high complex anal fistula recovered well postoperatively,without any postoperative complications or anal dysfunction.Anal function returned to normal after 17 months of follow-up.CONCLUSION The modified TROPIS procedure is the most minimally invasive surgery for anal fistulas that minimally impairs anal function.It allows the complete removal of infected anal glands and reduces the risk of postoperative complications.Modified TROPIS via the intersphincteric approach is an alternative sphincter-preserving treatment for high complex anal fistulas. 展开更多
关键词 High complex anal fistula Inter-sphincteric infection Trans-anal opening of inter-sphincteric space PERIANAL Pelvic magnetic resonance imaging Anal function protection Case report
下载PDF
Development of a DFN-based probabilistic block theory approach for bench face angle design in open pit mining
2
作者 Jianhua Yan Xiansen Xing +4 位作者 Zhihai Li Weida Ni Liuyuan Zhao Chun Zhu Yuanyuan He 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期3047-3062,共16页
In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face ... In open pit mining,uncontrolled block instabilities have serious social,economic and regulatory consequences,such as casualties,disruption of operation and increased regulation difficulties.For this reason,bench face angle,as one of the controlling parameters associated with block instabilities,should be carefully designed for sustainable mining.This study introduces a discrete fracture network(DFN)-based probabilistic block theory approach for the fast design of the bench face angle.A major advantage is the explicit incorporation of discontinuity size and spatial distribution in the procedure of key blocks testing.The proposed approach was applied to a granite mine in China.First,DFN models were generated from a multi-step modeling procedure to simulate the complex structural characteristics of pit slopes.Then,a modified key blocks searching method was applied to the slope faces modeled,and a cumulative probability of failure was obtained for each sector.Finally,a bench face angle was determined commensurate with an acceptable risk level of stability.The simulation results have shown that the number of hazardous traces exposed on the slope face can be significantly reduced when the suggested bench face angle is adopted,indicating an extremely low risk of uncontrolled block instabilities. 展开更多
关键词 open pit mine Bench face angle Block theory Probabilistic approach Discrete fracture network modeling Fractured rock slope
下载PDF
Failure behavior around a circular opening in a rock mass with non-persistent joints:A parallel-bond stress corrosion approach 被引量:3
3
作者 YANG Xu-xu JING Hong-wen +1 位作者 CHEN Kun-fu YANG Sheng-qi 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第10期2406-2420,共15页
The stability of underground excavations is influenced by discontinuities interspaced in surrounding rock masses as well as the stress condition. In this work, a numerical study was undertaken on the failure behavior ... The stability of underground excavations is influenced by discontinuities interspaced in surrounding rock masses as well as the stress condition. In this work, a numerical study was undertaken on the failure behavior around a circular opening in a rock mass having non-persistent open joints using PFC software package. A parallel-bond stress corrosion(PSC) approach was incorporated to drive the failure of rock mass around the circular opening, such that the whole progressive failure process after excavation was reproduced. Based on the determined micro parameters for intact material and joint segments, the failure process around the circular opening agrees very well with that obtained through laboratory experiment. A subsequent parametric study was then carried out to look into the influence of lateral pressure coefficient, joint dip angle and joint persistency on the failure pattern and crack evolution of the rock mass around the circular opening. Three failure patterns identified are step path failure, planar failure and rotation failure depending on the lateral pressure coefficient. Moreover, the increment of joint dip angle and joint persistency aggravates the rock mass failure around the opening. This study offers guideline on stability estimation of underground excavations. 展开更多
关键词 failure behavior circular opening non-persistent joint PFC software package stress corrosion
下载PDF
Sensor location in concrete slabs with various layout of opening using modified ‘FEMS-COMAC’ approach 被引量:1
4
作者 H.Vosoughifar P.Manafi 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2020年第1期205-222,共18页
Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most... Two-way concrete slabs are widely used around the world for the construction of many types of infrastructures and common buildings. The optimal sensor placement(OSP) in slabs with various opening positions is the most important issue in structural health monitoring(SHM) to increase reliability. In this study, a novel approach of OSP was evaluated to obtain the number and placement of sensors using examination of the closed loop performance. The nonlinear finite element(NFE) was used to discretize the mechanism behavior of slab. Multi-Objective Optimization based on the coordinate modal assurance criterion(COMAC) and cost considerations was considered in the optimization processes. All of the analysis, discretization and optimization process was designed and developed as a novel approach in Matlab by the author under the name ‘FEMS-COMAC’(FEM analysis of slab with COMAC). The points in the finite element method(FEM) mesh were classified as line by line information along the slab. The OSP in each line was optimized according to the objective function. The slabs with various width, thickness, aspect ratio and opening position were selected as case studies. The results of the OSP using the COMAC algorithm around the slab openings were compared with the novel ‘FEMS-COMAC’ method. The statistical analysis according Mann-Whitney criteria shows that there were significant differences between them in some of the case studies(mean P-value=0.54). 展开更多
关键词 two-way concrete slabs openingS OSP MAC COMAC
下载PDF
Effect of Mouth Opening Training Stick Combined with Oral Massage on Mouth Opening Difficulty in Head and Neck Cancer Patients after Treatment
5
作者 Jinhua Liu Qiong Wen 《Journal of Biosciences and Medicines》 2024年第6期43-51,共9页
Objective: To study the application effect of mouth-opening training sticks combined with oral massage on patients with mouth-opening difficulty after treatment for head and neck cancer. Methods: Using convenient samp... Objective: To study the application effect of mouth-opening training sticks combined with oral massage on patients with mouth-opening difficulty after treatment for head and neck cancer. Methods: Using convenient sampling, 60 patients with mouth-opening difficulty after treatment for head and neck cancer admitted to the Oncology Department from February 2022 to October 2023 were selected for a 2-week exercise and nursing program. The patients were divided into a control group (February 1, 2022 to November 30, 2022) and an observation group (December 1, 2022 to October 31, 2023), with 30 patients in each group. The control group underwent routine mouth-opening functional exercises combined with cork for oral support training, while the observation group underwent routine mouth-opening functional exercises combined with oral massage and mouth-opening training sticks for oral support training. The mouth-opening degree, mouth-opening difficulty level, comfort level, compliance, and quality of life were observed in both groups. Results: Before the intervention, there were no statistically significant differences in mouth-opening degree and mouth-opening difficulty level between the two groups (P > 0.05). After the intervention, the mouth-opening degree, mouth-opening difficulty level, oral comfort level, compliance, and QLICP-HN scores in the observation group were all better than those in the control group, with statistically significant differences (P < 0.05). Conclusion: The combination of mouth-opening training sticks and oral massage with mouth-opening functional exercises can effectively improve the degree of mouth-opening difficulty, enhance oral comfort, increase compliance with mouth-opening exercises, and improve quality of life. 展开更多
关键词 Head and Neck Cancer Difficulty in opening the Mouth open Mouth Training Stick Oral Massage Rehabilitation Effect
下载PDF
Watson-Jones Anatomical Approach for Open Reduction and Internal Fixation of Proximal Femoral Fractures without Image Intensifier in a Low-Resource Setting
6
作者 Loïc Fonkoue Gaspary Fodjeu +6 位作者 Kennedy Olivier Muluem Olivier Ngongang Theophile Nana Marie Ange Ngo Yamben DésiréAkaba Urich Tambekou Daniel Eone Handy 《Open Journal of Orthopedics》 2024年第4期173-186,共14页
Introduction: Standard procedures for surgical fixation of proximal femoral fractures (PFF) require an image intensifier which in developing countries remains a luxury. We hypothesized that, with a well-codified techn... Introduction: Standard procedures for surgical fixation of proximal femoral fractures (PFF) require an image intensifier which in developing countries remains a luxury. We hypothesized that, with a well-codified technique, the Watson Jones approach (WJA) without image intensifier nor traction table, can allow open reduction and internal fixation (ORIF) of PFF using Dynamic hip screw (DHS), with satisfactory outcome. Patients and methods: Forty one consecutive patients (mean age 59.5 ± 21.6 years, 61% males) who were followed in a Teaching Hospital for PFF treated by ORIF using the WJA and DHS from January 2016 to December 2020 were reassessed. The outcome measures were the quality of the reduction, the positioning of the implants, the tip-apex distance (TAD), the rate and delay of consolidation, the functional results using Postel Merle d’Aubigné (PMA) score, the rate of surgical site infection (SSI) and the overall mortality. Logistic regression was used to determine factors associated with mechanical failure. Results: The mean follow-up period was 33.8 ± 15.0 months. Fracture reduction was good in 31 (75.6%) cases and acceptable in 8(19.5%) cases. Implant position was fair to good in 37 (90.2%) patients. The mean TAD was 26.1 ± 3.9 mm. Three patients developed SSI. Consolidation was achieved in 38 (92.6%) patients. The functional results were good to excellent in 80.5% of patients. The overall mortality rate was 7.3%. There were an association between mechanical failure and osteoporosis (p = 0.04), fracture reduction (p = 0.003), and TAD (p = 0.025). In multivariate logistic regression, no independent factors were predictive of mechanical failure. Conclusion: This study shows that ORIF using DHS for PFF via the Watson-Jones approach without an image intensifier can give satisfactory anatomical and functional outcomes in low-resource settings. It provides and validates a reliable and reproducible technique that deserves to be diffused to surgeons in austere areas over the world. 展开更多
关键词 Proximal Femoral Fracture Watson-Jones approach Dynamic Hip Screw Low Resource Setting
下载PDF
FURTHER OPENING- UP IS KEY FOR CHINA’S HIGH-QUALITY DEVELOPMENT
7
作者 Tom Fowdy 《China Report ASEAN》 2024年第1期64-64,共1页
The Central Economic Work Conference was held in Beijing from December 11 to 12.The conference discussed the plans,prospects and challenges for China’s economy heading into 2024,as well as evaluating the events of th... The Central Economic Work Conference was held in Beijing from December 11 to 12.The conference discussed the plans,prospects and challenges for China’s economy heading into 2024,as well as evaluating the events of this year.It goes without saying that 2023 has been a challenging year for countries around the world as the global context has been unsatisfactory.Various geopolitical tensions have created a rise in uncertainties which have led to reduced growth worldwide and sent many economies into stagnation.In light of the critical factors affecting the stability of the global economy,China’s primary economic goal corresponds with the promotion and sustaining of free trade. 展开更多
关键词 PROMOTION HEADING open
下载PDF
National Image Construction from the Perspective of Multimodal Metaphor-A Case Study of the Opening Ceremony of the Beijing Winter Olympics
8
作者 LUO Yi ZHOU Jing 《Journal of Literature and Art Studies》 2024年第4期290-294,共5页
The national image is a comprehensive concept with a distinct political feature,including the international image presented to the outside world,and also encompassing the national identity of the people.With the devel... The national image is a comprehensive concept with a distinct political feature,including the international image presented to the outside world,and also encompassing the national identity of the people.With the development of globalization,international cultural communication has become a crucial part of shaping the national image,and the opening ceremony of the Beijing Winter Olympics has become an important opportunity for China to showcase its national image to the world in the post-pandemic era.Based on Forceville’s multimodal metaphor theory,this paper examines the metaphorical phenomena contained in the performance and their functions,effects,and purposes in the construction of the national image.It is found that there are many scenes,images,and narratives in the opening ceremony,including war metaphor,competition metaphor,personification metaphor,and other conceptual metaphors.The focus of this paper is on multimodal metaphor in a broad sense,mainly encompassing auditory and visual modes.Through the use of these multimodal metaphors,the opening ceremony of the Winter Olympics builds an image of a vibrant,peace-loving,and responsible country,which not only demonstrates China’s cultural self-confidence,but also expresses the Chinese people’s beautiful vision for the early reunification of the motherland. 展开更多
关键词 multimodal metaphor national image Olympic Winter Games opening Ceremony
下载PDF
CIIE to Promote High-Level Opening Up
9
《ChinAfrica》 2024年第11期60-61,共2页
The 7th China International Import Expo(CIIE),scheduled to be held in Shanghai from 5 to 10 November,will play a part in promoting highlevel opening up,said Tang Wenhong,China’s assistant minister of commerce,at a pr... The 7th China International Import Expo(CIIE),scheduled to be held in Shanghai from 5 to 10 November,will play a part in promoting highlevel opening up,said Tang Wenhong,China’s assistant minister of commerce,at a press conference on 23 October.The CIIE serves to showcase China’s major opening-up measures and confidence,to share China’s new development opportunities with other countries. 展开更多
关键词 opening measures scheduled
下载PDF
Induced pluripotent stem cell-related approaches to generate dopaminergic neurons for Parkinson's disease
10
作者 Ling-Xiao Yi Hui Ren Woon +3 位作者 Genevieve Saw Li Zeng Eng King Tan Zhi Dong Zhou 《Neural Regeneration Research》 SCIE CAS 2025年第11期3193-3206,共14页
The progressive loss of dopaminergic neurons in affected patient brains is one of the pathological features of Parkinson's disease,the second most common human neurodegenerative disease.Although the detailed patho... The progressive loss of dopaminergic neurons in affected patient brains is one of the pathological features of Parkinson's disease,the second most common human neurodegenerative disease.Although the detailed pathogenesis accounting for dopaminergic neuron degeneration in Parkinson's disease is still unclear,the advancement of stem cell approaches has shown promise for Parkinson's disease research and therapy.The induced pluripotent stem cells have been commonly used to generate dopaminergic neurons,which has provided valuable insights to improve our understanding of Parkinson's disease pathogenesis and contributed to anti-Parkinson's disease therapies.The current review discusses the practical approaches and potential applications of induced pluripotent stem cell techniques for generating and differentiating dopaminergic neurons from induced pluripotent stem cells.The benefits of induced pluripotent stem cell-based research are highlighted.Various dopaminergic neuron differentiation protocols from induced pluripotent stem cells are compared.The emerging three-dimension-based brain organoid models compared with conventional two-dimensional cell culture are evaluated.Finally,limitations,challenges,and future directions of induced pluripotent stem cell–based approaches are analyzed and proposed,which will be significant to the future application of induced pluripotent stem cell-related techniques for Parkinson's disease. 展开更多
关键词 dopaminergic neurons induced pluripotent stem cells Parkinson's disease stem cell approaches
下载PDF
Enhancing perianal disease management with integrated physical and psychological approaches
11
作者 Uchenna E Okpete Haewon Byeon 《World Journal of Clinical Cases》 SCIE 2025年第2期59-63,共5页
This article provides a comprehensive analysis of the study by Hou et al,focusing on the complex interplay between psychological and physical factors in the postoperative recovery(POR)of patients with perianal disease... This article provides a comprehensive analysis of the study by Hou et al,focusing on the complex interplay between psychological and physical factors in the postoperative recovery(POR)of patients with perianal diseases.The study sheds light on how illness perception,anxiety,and depression significantly influence recovery outcomes.Hou et al developed a predictive model that demonstrated high accuracy in identifying patients at risk of poor recovery.The article explores the critical role of pre-operative psychological assessment,highlighting the need for mental health support and personalized recovery plans in enhancing POR quality.A multidisciplinary approach,integrating mental health professionals with surgeons,anesthesiologists,and other specialists,is emphasized to ensure comprehensive care for patients.The study’s findings serve as a call to integrate psychological care into surgical practice to optimize outcomes for patients with perianal diseases. 展开更多
关键词 Perianal disease Post-operative recovery ANXIETY DEPRESSION Pain management Emotional well-being Multidisciplinary approach
下载PDF
A modified percutaneous approach through external opening of foramen rotundum:an anatomical study
12
作者 Dai Luohuan Liu Donghua +5 位作者 Qiao Pudan Chen Liangyu Liu Dalin Zhao Yuqi Tang Bo Deng Guangqi 《解剖学杂志》 CAS 2021年第S01期37-38,共2页
To provide the anatomical data for percutaneous radiofrequency thermocoagulation through foramen rotundum approach via anterior border of coronoid process in the treatment of V2 trigeminal neuralgia.80 dried cadaveric... To provide the anatomical data for percutaneous radiofrequency thermocoagulation through foramen rotundum approach via anterior border of coronoid process in the treatment of V2 trigeminal neuralgia.80 dried cadaveric adult skulls(160 sides)were examined.The depth of the first arrival with the needle from the lower margin of the zygomatic arch to the maxillary surface(L1),the depth(L2)that the needle reached the maxillary margin of pterygomaxillary fissure,and gliding distance(L3),the fissure width that the needle reached the maxillary margin of pterygomaxillary fissure(L4),the maximum length(LA)and width(LB)of the skull were measured.On the left side,the reference ranges of L1,L2,L3,L4 were(23.04±3.42)mm,(38.14±3.63)mm,(20.67土3.93)mm,(5.85土1.27)mm,respectively.And on the right side,these parameters were(22.96土3.34)mm,(38.40±3.49)mm,(20.82±3.93)mm,(5.86土1.33)mm,respectively. 展开更多
关键词 NEEDLE PERCUTANEOUS approach
下载PDF
Web service based spatial forest information system using an open source software approach 被引量:3
13
作者 李世明 Joachim Saborowski +3 位作者 Jens Nieschulze 李增元 陆元昌 陈尔学 《Journal of Forestry Research》 SCIE CAS CSCD 2007年第2期85-90,共6页
For technical and other reasons there is a dilemma that data providers cannot find an appropriate way to redistribute spatial forest data and data users who need spatial data cannot access and integrate available fore... For technical and other reasons there is a dilemma that data providers cannot find an appropriate way to redistribute spatial forest data and data users who need spatial data cannot access and integrate available forest resources information. To overcome this dilemma, this paper proposed a spatial forest information system based on Web service using an open source software approach. With Web service based architecture, the system can enable interoperability, integrate Web services from other application servers, reuse codes, and shorten the development time and cost. At the same time, it is possible to extend the local system to a regional or national spatial forest information system. The growth of Open Source Software (OSS) provides an alternative choice to proprietary software for operating systems, web servers, Web-based GIS applications and database management systems. Using open source software to develop spatial forest information systems can greatly reduce the cost while providing high performance and sharing spatial forest information. We chose open source software to build a prototype system for Xixia County, Henan Province, China. By integrating OSS packages Deegree and UMN MapServer which are compliant to the OGC open specifications, the prototype system enables users to access spatial forest information and travelling information of Xixia County which come from two different data servers via a standard Web browser and promotes spatial forest information sharing. 展开更多
关键词 Web service spatial forest information system open Source Software Deegree UMN MapServer
下载PDF
Stomatal Opening Induced by Acetylcholine Is Associated with Cytoskeletal Components 被引量:2
14
作者 黄荣峰 王学臣 娄成后 《Acta Botanica Sinica》 CSCD 2000年第6期559-563,共5页
Acetylcholine (Ach) is a key component of animal cholinergic system. Recent experiments demonstrated that Ach, choline acetyltransferase, acetylcholinesterase and Ach receptors are present in all parts of plants and... Acetylcholine (Ach) is a key component of animal cholinergic system. Recent experiments demonstrated that Ach, choline acetyltransferase, acetylcholinesterase and Ach receptors are present in all parts of plants and have many functions, including inducing stomatal movement. The authors' previous work has evidenced that microtubules and microfilaments are involved in regulating both stomatal closing and opening. The present investigation is to determine whether stomatal opening induced by Ach is associated with microtubules and microfilaments. The results showed that Ach could induce stomatal opening of Vicia faba L. with or without addition of KCl in the dark. Ach also stimulated protoplast swelling in a K +_free solution in the dark. However, the induction was partially suppressed when the strips and protoplasts were pretreated with either cytochalasin B, an inhibitor of F_actin polymerization, or oryzalin, an inhibitor of plant microtubule polymerization. Thus, our data suggest for the first time that stomatal opening induced by Ach is associated with the dynamics of microtubules and microfilaments. 展开更多
关键词 MICROTUBULE MICROFILAMENT ACETYLCHOLINE Vicia faba stomatal opening
下载PDF
All-round Translation Teaching Approach Suitable for Adult Learners of the Open Distance Education
15
作者 郭峰池 《海外英语》 2011年第9X期152-154,共3页
Through the analysis of the characteristics of the adult students in the open distance education and on the basis of constructivism,the researcher tentatively proposed an All-round Translation Teaching Approach under ... Through the analysis of the characteristics of the adult students in the open distance education and on the basis of constructivism,the researcher tentatively proposed an All-round Translation Teaching Approach under the guidance of the theories of constructivism in order to improve translation teaching of the open distance education. 展开更多
关键词 TRANSLATION teaching approach CONSTRUCTIVISM open DISTANCE education ADULT STUDENTS
下载PDF
一种基于改进path opening的道路提取新方法 被引量:8
16
作者 王双 曹国 《计算机科学》 CSCD 北大核心 2014年第2期285-289,共5页
提出了一种基于改进path opening的高分辨率遥感影像道路提取新方法。为检测曲率较大的道路,构造了新的邻接图;为有效提取有损或有部分遮挡的道路,将path opening算法中的最大路径长度与区域的几何特征相结合,建立了道路区域的判定准则... 提出了一种基于改进path opening的高分辨率遥感影像道路提取新方法。为检测曲率较大的道路,构造了新的邻接图;为有效提取有损或有部分遮挡的道路,将path opening算法中的最大路径长度与区域的几何特征相结合,建立了道路区域的判定准则,减少了人工干预。通过多组实验结果证明,该方法对于不完整道路的提取有更好的效果。 展开更多
关键词 PATH opening 有损道路 道路提取 几何特征
下载PDF
Opening Moves Involved in Text-based Computer-Mediated-Communication (CMC) by Chinese Adults
17
作者 李莉华 《海外英语》 2011年第3X期257-258,260,共3页
The development of science and technology has made it not only possible but very convenient for people living in different parts of the world to communicate with each other, thus bringing forth a new form of communica... The development of science and technology has made it not only possible but very convenient for people living in different parts of the world to communicate with each other, thus bringing forth a new form of communication: computer-mediated communication (CMC). Text-based CMC is one of the most popular forms of CMC in which people send instant messages to others in different settings. Since this mode of interaction combines features of both the written and spoken language (Greenfield & Subrahmanyam, 2003), it's of great interest whether it follows the same sequential rule as the telephone conversation. However, compared to telephone conversations, computer-mediated communication has received much less attention, let alone text-based CMC. The existing body of literature mostly focuses on content analysis and linguistic features but neglects the sequential organization of such interaction (Paolillo, 1999; Greenfield and Subrahmanyam, 2003; Herring, 1999). In light of this, this paper examines the opening moves of instant message exchanges among Chinese adults in an attempt to find out the unique features characterizing the way they open an online chat. The framework that was chosen for data analysis was the sequential model proposed by Schegloff for American telephone openings. 展开更多
关键词 computer-mediated communication(CMC) Text-based CMC opening MOVES instant message exchanges on line chat sequential model
下载PDF
Surgical outcomes of mini-open Wiltse approach and conventional open approach in patients with single-segment thoracolumbar fractures without neurologic injury 被引量:47
18
作者 Haijun Li Lei Yang +3 位作者 Hao Xie Lipeng Yu Haifeng Wei Xiaojian Cao 《The Journal of Biomedical Research》 CAS CSCD 2015年第1期76-82,共7页
This study aimed to introduce a novel mini-open pedicle screw fixation technique via Wiltse approach, and com- pared it with the traditional posterior open method. A total of 72 cases of single-segment thoracolumbar f... This study aimed to introduce a novel mini-open pedicle screw fixation technique via Wiltse approach, and com- pared it with the traditional posterior open method. A total of 72 cases of single-segment thoracolumbar fractures without neurologic injury underwent pedicle screw fixation via two different approaches. Among them, 37 patients were treated using posterior open surgery, and 35 patients received mini-open operation via Wiltse approach. Crew placement accuracy rate, operative time, blood loss, postoperative drainage, postoperative hospitalization time, radiation exposure time, postoperative improvement in R value, Cobb's angle and visual analog scale (VAS) scores of the two methods were compared. There were no significant differences in the accuracy rate of pedicle screw placement, radiation exposure and postoperative R value and Cobb's angle improvement between the two groups. However, the mini-open method had obvious advantages over the conventional open method in operative time, blood loss, postoperative drainage, postoperative hospitalization time, and postoperative improvement in VAS. The mini-open pedicle screw technique could be applied in treatment of single-segment thoracolumbar fracture without neurologic injury and had advantages of less tissue trauma, short operative and rehabilitative time on the premise of guaranteed accuracy rate and no increased radiation exposure. 展开更多
关键词 thoracolumbar fracture pedicle screw MINI-open Wiltse approach minimally invasive
下载PDF
Investigating the mechanical and acoustic emission characteristics of brittle failure around a circular opening under uniaxial loading 被引量:10
19
作者 Peng Li Fen-hua Ren +3 位作者 Mei-feng Cai Qi-feng Guo Hao-fei Wang Kang Liu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第10期1217-1230,共14页
The size of underground openings in rock masses in metal mines is critical to the performance of the openings. In this study, the mechanical and acoustic emission (AE) characteristics of brittle rock-like specimens co... The size of underground openings in rock masses in metal mines is critical to the performance of the openings. In this study, the mechanical and acoustic emission (AE) characteristics of brittle rock-like specimens containing a circular opening with different ratios of opening diameter to sample size λ (λ = 0.1, 0.13, 0.17, 0.2, and 0.23) were investigated under uniaxial compression with AE monitoring. The results indicate that the opening size strongly affected the peak strength and the elastic modulus. Crack initiation first started from the upper surface of the specimens, not from the periphery of the openings. Tensile and shear cracks coexisted on the roof and floor of the specimens, whereas tensile cracks were dominant on the two sides. The fracture mode of samples with openings was partially affected by the relative size of the pillars and openings. The AE response curves (in terms of counts, cumulative energy, cumulative counts, and b-value) show that brittle failure was mainly a progressive process. Moreover, the AE information corresponded well with microcrack evolution in the samples and thus can be used to predict sample failure. 展开更多
关键词 ROCK MECHANICS CIRCULAR opening opening size UNIAXIAL compression acoustic emission
下载PDF
Study on transient aerodynamic characteristics of parachute opening process 被引量:20
20
作者 Li Yu Xiao Ming 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2007年第6期627-633,共7页
In the research of parachute, canopy inflation process modeling is one of the most complicated tasks. As canopy often experiences the largest deformations and loa-dings during a very short time, it is of great difficu... In the research of parachute, canopy inflation process modeling is one of the most complicated tasks. As canopy often experiences the largest deformations and loa-dings during a very short time, it is of great difficulty for theoretical analysis and experimental measurements. In this paper, aerodynamic equations and structural dynamics equations were developed for describing parachute opening process, and an iterative coupling solving strategy incorpo- rating the above equations was proposed for a small-scale, flexible and flat-circular parachute. Then, analyses were carried out for canopy geometry, time-dependent pressure difference between the inside and outside of the canopy, transient vortex around the canopy and the flow field in the radial plane as a sequence in opening process. The mechanism of the canopy shape development was explained from perspective of transient flow fields during the inflation process. Experiments of the parachute opening process were conducted in a wind tunnel, in which instantaneous shape of the canopy was measured by high velocity camera and the opening loading was measured by dynamometer balance. The theoretical predictions were found in good agreement with the experimental results, validating the proposed approach. This numerical method can improve the situation of strong dependence of parachute research on wind tunnel tests, and is of significance to the understanding of the mechanics of parachute inflation process. 展开更多
关键词 PARACHUTE opening process Numerical simulation Flow field characteristics AERODYNAMICS Structural dynamics
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部