期刊文献+
共找到103篇文章
< 1 2 6 >
每页显示 20 50 100
Advanced Optimized Anomaly Detection System for IoT Cyberattacks Using Artificial Intelligence
1
作者 Ali Hamid Farea Omar H.Alhazmi Kerem Kucuk 《Computers, Materials & Continua》 SCIE EI 2024年第2期1525-1545,共21页
While emerging technologies such as the Internet of Things(IoT)have many benefits,they also pose considerable security challenges that require innovative solutions,including those based on artificial intelligence(AI),... While emerging technologies such as the Internet of Things(IoT)have many benefits,they also pose considerable security challenges that require innovative solutions,including those based on artificial intelligence(AI),given that these techniques are increasingly being used by malicious actors to compromise IoT systems.Although an ample body of research focusing on conventional AI methods exists,there is a paucity of studies related to advanced statistical and optimization approaches aimed at enhancing security measures.To contribute to this nascent research stream,a novel AI-driven security system denoted as“AI2AI”is presented in this work.AI2AI employs AI techniques to enhance the performance and optimize security mechanisms within the IoT framework.We also introduce the Genetic Algorithm Anomaly Detection and Prevention Deep Neural Networks(GAADPSDNN)sys-tem that can be implemented to effectively identify,detect,and prevent cyberattacks targeting IoT devices.Notably,this system demonstrates adaptability to both federated and centralized learning environments,accommodating a wide array of IoT devices.Our evaluation of the GAADPSDNN system using the recently complied WUSTL-IIoT and Edge-IIoT datasets underscores its efficacy.Achieving an impressive overall accuracy of 98.18%on the Edge-IIoT dataset,the GAADPSDNN outperforms the standard deep neural network(DNN)classifier with 94.11%accuracy.Furthermore,with the proposed enhancements,the accuracy of the unoptimized random forest classifier(80.89%)is improved to 93.51%,while the overall accuracy(98.18%)surpasses the results(93.91%,94.67%,94.94%,and 94.96%)achieved when alternative systems based on diverse optimization techniques and the same dataset are employed.The proposed optimization techniques increase the effectiveness of the anomaly detection system by efficiently achieving high accuracy and reducing the computational load on IoT devices through the adaptive selection of active features. 展开更多
关键词 Internet of Things SECURITY anomaly detection and prevention system artificial intelligence optimization techniques
下载PDF
Investigation of Microstructure, Microhardness and Thermal Properties of Ag-In Intermetallic Alloys Prepared by Vacuum Arc Meltings
2
作者 ÇELİK Erçevik ATA ESENER Pınar +1 位作者 ÖZTÜRK Esra AKSÖZ Sezen 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第1期182-187,共6页
Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical com... Ag-In intermetallic alloys were produced by using vacuum arc furnace. Differential Scanning Calorimetry(DSC) and Energy Dispersive X-Ray Spectrometry(EDX) were used to determine the thermal properties and chemical composition of the phases respectively. Microhardness values of Ag-In intermetallics were calculated with Vickers hardness measurement method. According to the experimental results, Ag-34 wt%In intermetallic system generated the best results of energy saving and storage compared to other intermetallic systems. Also from the microhardness results, it was observed that intermetallic alloys were harder than pure silver and Ag-26 wt%In system had the highest microhardness value with 143.45 kg/mm^(2). 展开更多
关键词 thermal properties microstructure characterization MICROHARDNESS ALLOYS material characterization
下载PDF
Advances in the treatment of autism spectrum disorder:Wharton jelly mesenchymal stem cell transplantation
3
作者 Serdar Kabatas ErdinçCivelek +3 位作者 Eyüp Can Savrunlu Umut Karaaslan Özlem Yıldız Erdal Karaöz 《World Journal of Methodology》 2025年第1期72-79,共8页
BACKGROUND Autism spectrum disorder(ASD)is a complex neurodevelopmental disorder with multifaceted origins.In recent studies,neuroinflammation and immune dysregulation have come to the forefront in its pathogenesis.Th... BACKGROUND Autism spectrum disorder(ASD)is a complex neurodevelopmental disorder with multifaceted origins.In recent studies,neuroinflammation and immune dysregulation have come to the forefront in its pathogenesis.There are studies suggesting that stem cell therapy may be effective in the treatment of ASD.AIM To evolve the landscape of ASD treatment,focusing on the potential benefits and safety of stem cell transplantation.METHODS A detailed case report is presented,displaying the positive outcomes observed in a child who underwent intrathecal and intravenous Wharton’s jelly-derived mesenchymal stem cells(WJ-MSCs)transplantation combined with neurorehabilitation.RESULTS The study demonstrates a significant improvement in the child’s functional outcomes(Childhood Autism Rating Scale,Denver 2 Developmental Screening Test),especially in language and gross motor skills.No serious side effects were encountered during the 2-year follow-up.CONCLUSION The findings support the safety and effectiveness of WJ-MSC transplantation in managing ASD. 展开更多
关键词 Autism spectrum disorder NEUROREHABILITATION Stem cell transplantation Wharton jelly mesenchymal stem cells INFLAMMATION
下载PDF
High-resolution seismicity imaging and early aftershock migration of the 2023 Kahramanmara?(SE Türkiye)M_W7.9&7.8 earthquake doublet 被引量:7
4
作者 Hongyang Ding Yijian Zhou +5 位作者 Zengxi Ge Tuncay Taymaz Abhijit Ghosh Haoyu Xu Tahir Serkan Irmak Xiaodong Song 《Earthquake Science》 2023年第6期417-432,共16页
We build a high-resolution early aftershock catalog for the 2023 SE Türkiye seismic sequence with PALM,a seamless workflow that sequentially performs phase picking,association,location,and matched filter for cont... We build a high-resolution early aftershock catalog for the 2023 SE Türkiye seismic sequence with PALM,a seamless workflow that sequentially performs phase picking,association,location,and matched filter for continuous data.The catalog contains 29,519 well-located events in the two mainshocks rupture region during 2023-02-01–2023-02-28,which significantly improves the detection completeness and relocation precision compared to the public routine catalog.Employing the new PALM catalog,we analyze the structure of the seismogenic fault system.We find that the Eastern Anatolian Fault(EAF)that generated the first M_(W)7.9 mainshock is overall near-vertical,whereas complexities are revealed in a small-scale,such as subparallel subfaults,unmapped branches,and stepovers.The seismicity on EAF is shallow(<15 km)and concentrated in depth distribution,indicating a clear lock-creep transition.In contrast,the SürgüFault(SF)that is responsible for the second M_(W)7.8 mainshock is shovel-shaped for the nucleation segment and has overall low dip angles(~40°–80°).Aftershocks on the SF distribute in a broad range of depth,extending down to~35 km.We also analyze the temporal behavior of seismicity,discovering no immediate foreshocks within~5 days preceding the first mainshock,and no seismic activity on the SF before the second mainshock. 展开更多
关键词 2023 Türkiye Earthquake Doublet aftershock catalog PALM fault imaging aftershock migration
下载PDF
工业负荷可持续并网太阳能光伏的可行性评价 被引量:2
5
作者 Kamlesh KUMAR Amir Mahmood SOOMRO +2 位作者 Mahesh KUMAR Laveet KUMAR Müslüm ARICI 《Journal of Central South University》 SCIE EI CAS CSCD 2023年第11期3575-3585,共11页
可再生能源发电因其间歇性而具有多变性,对发展中国家来说,可再生能源发电的成本很高。由于电价定价和机制设计不合理,上网电价和净计量等支持性政策和方案对消费者也没有太大吸引力。屋顶太阳能光伏系统自用技术可以避免这些方案的缺点... 可再生能源发电因其间歇性而具有多变性,对发展中国家来说,可再生能源发电的成本很高。由于电价定价和机制设计不合理,上网电价和净计量等支持性政策和方案对消费者也没有太大吸引力。屋顶太阳能光伏系统自用技术可以避免这些方案的缺点,因为这种技术比公用电网的发电成本更低。因此,产消者可以以最低价格使用大部分电力,更具吸引力。本文分析了并网工业太阳能光伏发电系统的成本和可行性。结果发现,基于储能并网的光伏系统成本为0.0086$/(kW·h),公用电网将以0.062$/(kW·h)的价格出售给产消者,与使用时间评级模型相比,年能源成本将降低35.23%。此外,所提出的方案可满足96%的年能源需求,保证了供应的安全性,所提出的模型可用于其他发展中国家。 展开更多
关键词 自用消费 自给自足 净计量 进料关税 网格存储 光伏系统
下载PDF
Pulse-like ground motion observed during the 6 February 2023 M_(W)7.8 Pazarcık Earthquake(Kahramanmaraş,SE Türkiye) 被引量:2
6
作者 Fan Wu Junju Xie +6 位作者 Zhao An Chenghao Lyu Tuncay Taymaz Tahir Serkan Irmak Xiaojun Li Zengping Wen Baofeng Zhou 《Earthquake Science》 2023年第4期328-339,共12页
In this study,we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 M_(W)7.8 Pazarcık(Kahramanmaraş)Earthquake in SE Türkiye.The wavelet... In this study,we analyzed 100 three-component strong ground motion records observed within 200 km of the causative fault of the 6 February 2023 M_(W)7.8 Pazarcık(Kahramanmaraş)Earthquake in SE Türkiye.The wavelet method was utilized to identify and analyze the characteristics of pulse-like ground motions in the near-fault region,while considering the uncertainty of the pulse orientation during the analysis.Our investigation focused on the effects of the focal mechanism and rupture process on the spatial distribution,pulse orientation,and maximum pulse direction of the observed pulse-like ground motion.We also analyzed the amplitude and period of the observed ground pulses and the effect of long-period amplification on the ground motion response spectra.Our results indicated the following:(1)A total of 21 typical ground velocity pulses were observed during this earthquake,exhibiting complex characteristics due to the influence of the strike-slip mechanism and rupture directivity.Most ground pulses(17 out of 21)were recorded within 20 km of the fault,in a wide range of orientations,including normal and parallel to the fault direction.The waveforms exhibited unidirectional features,indicating the effects of left-lateral fault slip.Distinct pulses observed more than 20 km from the fault were mainly oriented normal to the fault.The waveforms were bidirectional with double-or multi-round trips as a result of rupture directivity.(2)The amplitudes of the observed pulses ranged from 30.5 to 220.0 cm/s,with the largest peak velocity of 220.0 cm/s observed at Station 3138.The pulse periods ranged from 2.3 to 14.5 s,with the longest pulse period of 14.5 s observed at Station 3116.The amplitude and period of the pulses observed during this earthquake were comparable to those of similar-magnitude global earthquakes.The amplitude of the pulses decreased significantly with increasing fault distance,whereas the pulse period was not significantly affected by the fault distance.(3)Compared with non-pulse records,the velocity pulse records had a pronounced amplification effect on the acceleration response spectra near the pulse period,with factors ranging from 2.1 to 5.8.The larger velocity pulses also significantly amplified the velocity response spectra,particularly over the long periods.This significant amplification effect of the pulses on the response spectra leads to empirical models underestimating the long-period earthquake ground motion. 展开更多
关键词 2023 M_(W)7.8 Pazarcık Earthquake pulse-like ground motion response spectrum predominant period
下载PDF
Investigation of the ^(121)Sb(α,γ)^(125)I reaction cross-section calculations at astrophysical energies
7
作者 M.Eroğlu C.Yalcın R.T.Güray 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第11期85-92,共8页
Proton-rich nuclei are synthesized via photodisintegration and reverse reactions.To examine this mechanism and reproduce the observed p-nucleus abundances,it is crucial to know the reaction rates and thereby the react... Proton-rich nuclei are synthesized via photodisintegration and reverse reactions.To examine this mechanism and reproduce the observed p-nucleus abundances,it is crucial to know the reaction rates and thereby the reaction cross sections of many isotopes.Given that the number of experiments on the reactions in astrophysical energy regions is very rare,the reaction cross sections are determined by theoretical methods whose accuracy should be tested.In this study,given that ^(121)Sb is a stable seed isotope located in the region of medium-mass p-nuclei,we investigated the cross sections and reaction rates of the ^(121)Sb(α,γ)^(125)I reaction using the TALYS computer code with 432 different combinations of input parameters(OMP,LDM,and SFM).The optimal model combinations were determined using the threshold logic unit method.The theoretical reaction cross-sectional results were compared with the experimental results reported in the literature.The reaction rates were determined using the two input parameter sets most compatible with the measurements,and they were compared with the reaction rate databases:STARLIB and REACLIB. 展开更多
关键词 Cross section Astrophysical S-factor Astrophysical reaction rate p-process nucleosynthesis Threshold logic unit method
下载PDF
太阳能/地热联合有机朗肯循环电厂的能量和火用优化
8
作者 Rafika MAALI Tahar KHIR Müslüm ARICI 《Journal of Central South University》 SCIE EI CAS CSCD 2023年第11期3601-3616,共16页
对突尼斯南部一个太阳能和地热能驱动的有机朗肯循环(ORC)电厂进行了能量和火用分析。分别研究了在冬季和夏季2天内主要运行参数对太阳能/地热联合ORC系统的影响,确定了系统的质量、能量和火用平衡。结果表明,系统不可逆性的主要来源是... 对突尼斯南部一个太阳能和地热能驱动的有机朗肯循环(ORC)电厂进行了能量和火用分析。分别研究了在冬季和夏季2天内主要运行参数对太阳能/地热联合ORC系统的影响,确定了系统的质量、能量和火用平衡。结果表明,系统不可逆性的主要来源是抛物面通流收集器。为了减少火用损耗,优化系统性能,采用多项式回归分析方法进行优化。由此建立了传热流体的质量流量和入口温度与太阳辐射的关系。该优化方案可使系统的火用效率在冬季提高2.06%~5.44%,在夏季提高1.00%~4.10%。此外,分析显示,在冬季,总能源效率和净功率分别提高了26.6%和21.0%。 展开更多
关键词 火用效率 太阳能 地热能 优化 有机朗肯循环
下载PDF
Preface:Energy and sustainable development
9
作者 Majid SIAVASHI Müslüm ARICI 《Journal of Central South University》 SCIE EI CAS CSCD 2023年第11期3517-3518,共2页
Energy demands are increasing continuously,and the development of sustainable technologies in energy systems is a critical and vital concern.Providing the required energy for social and economic needs in line with dim... Energy demands are increasing continuously,and the development of sustainable technologies in energy systems is a critical and vital concern.Providing the required energy for social and economic needs in line with diminishing the environmental effects and pollution emissions is necessary to meet sustainable development.Designing new energy systems with improved efficiency,securing the energy need,using clean and renewable energy sources,reducing energy losses and pollution,and expanding the availability and access to energy are the key elements of sustainable energy development. 展开更多
关键词 POLLUTION SUSTAINABLE CURING
下载PDF
PID and Fuzzy Logic Control of Ball and Beam System Using Particle Swarm Optimization
10
作者 Muhammad Alızada Sıtkı Ozturk 《World Journal of Engineering and Technology》 2023年第4期859-873,共15页
In this research, we carried out the modeling of the ball and beam system (BBS) within the MATLAB/Simulink framework by applying both proportional-integral-derivative (PID) and fuzzy logic control strategies to govern... In this research, we carried out the modeling of the ball and beam system (BBS) within the MATLAB/Simulink framework by applying both proportional-integral-derivative (PID) and fuzzy logic control strategies to govern the dynamics of this constructed model. The underlying non-linear dynamic equations adjusting the behavior of the BBS system are based on Newton’s second law of motion. The physical installation of the BBS, designed for potential real-time application, comprises a lengthy beam subject to movement through the action of a DC servomotor, with a ball traversing the beam in a reciprocating manner. A distance sensor is strategically placed in front of the beam to determine the exact position of the ball. In this system, an electrical control signal applied to the DC servomotor causes the beam to pivot about its horizontal axis, thereby enabling the ball to move freely along the beam's length. To avoid the risk of losing the ball equilibrium on the beam and to achieve precise system control, a mathematical model was devised and implemented within the MATLAB/Simulink environment. The use of the particle swarm optimization (PSO) algorithm was aimed at tackling the task of refining and optimizing the PID controller specifically designed for the linearized ball and beam control system. The presented system is controlled using both PID and fuzzy logic, and the use of the PSO algorithm enhances the system’s responsiveness efficiency. 展开更多
关键词 Ball and Beam System PID Fuzzy Logic DC Servomotor PSO
下载PDF
Development of New Machine Learning Based Algorithm for the Diagnosis of Obstructive Sleep Apnea from ECG Data
11
作者 Erdem Tuncer 《Journal of Computer Science Research》 2023年第3期15-21,共7页
In this study,a machine learning algorithm is proposed to be used in the detection of Obstructive Sleep Apnea(OSA)from the analysis of single-channel ECG recordings.Eighteen ECG recordings from the PhysioNet Apnea-ECG... In this study,a machine learning algorithm is proposed to be used in the detection of Obstructive Sleep Apnea(OSA)from the analysis of single-channel ECG recordings.Eighteen ECG recordings from the PhysioNet Apnea-ECG dataset were used in the study.In the feature extraction stage,dynamic time warping and median frequency features were obtained from the coefficients obtained from different frequency bands of the ECG data by using the wavelet transform-based algorithm.In the classification phase,OSA patients and normal ECG recordings were classified using Random Forest(RF)and Long Short-Term Memory(LSTM)classifier algorithms.The performance of the classifiers was evaluated as 90% training and 10%testing.According to this evaluation,the accuracy of the RF classifier was 82.43% and the accuracy of the LSTM classifier was 77.60%.Considering the results obtained,it is thought that it may be possible to use the proposed features and classifier algorithms in OSA classification and maybe a different alternative to existing machine learning methods.The proposed method and the feature set used are promising because they can be implemented effectively thanks to low computing overhead. 展开更多
关键词 ECG Sleep apnea CLASSIFICATION Dynamic time warping Median frequency
下载PDF
Design and Implementation of a Control System to Mitigate Osteonecrosis in Orthopedic Bone Drilling Procedures
12
作者 Kadir Gok Yasin Kisioglu Arif Gok 《Journal of Mechanical Materials and Mechanics Research》 2023年第1期16-21,共6页
The drilling process in orthopedic surgery can sometimes lead to an undesired increase in temperature,which can cause serious damage to bones and soft tissues.This overheating is typically identified as a temperature ... The drilling process in orthopedic surgery can sometimes lead to an undesired increase in temperature,which can cause serious damage to bones and soft tissues.This overheating is typically identified as a temperature above 47℃,known as the critical limit,and can result in the condition known as osteonecrosis.This study aims to develop a new control system,using a proportional-integral-derivative(PID)controller,to prevent overheating and the resulting osteonecrosis.The bone temperature is constantly measured using a thermocouple and,when it reaches the critical temperature of 47℃,the cooling device is activated by the PID-controlled system.This new control system makes the drill machine with cooling device more user-friendly and allows surgeons to set a desired temperature level manually. 展开更多
关键词 Bone drilling Orthopedic surgery OSTEONECROSIS PID controller Driller mechanism
下载PDF
Clinical characteristics and outcomes of nosocomial COVID-19 in Turkey:A retrospective multicenter study
13
作者 Süleyman Yıldırım Celalettin Yılmaz +29 位作者 Gülru Polat Serap Argun Baris İlknur Başyiğit İlknur Kaya Ceyda Anar Mihriban Bozkurt HüsnüBaykal Hulya Dirol Gamzenur Ozbey Emine Ozsari Emel Cireli Ali KadriÇırak Dursun Tatar Mine Gayaf Selen Karaoglanoglu Yener Aydin Atilla Eroglu Yıldız Olçar Berna Botan Yıldırım Bengül Gürsoy Deniz Demir Yılmaz Elif Yelda Ozgun Niksarlioglu Ramazan Eren Ayşegül Tomruk Erdem Müge Meltem Tor Fusun Fakili MustafaÇolak Merve Erçelik Ali Tabaru Özlem Ediboglu 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第8期347-353,共7页
Objective:To identify the clinical characteristics and outcomes of hospital-acquired SARS-CoV-2 infection during the vaccination period nationwide in Turkey.Methods:COVID-19 patients followed in the pandemic services ... Objective:To identify the clinical characteristics and outcomes of hospital-acquired SARS-CoV-2 infection during the vaccination period nationwide in Turkey.Methods:COVID-19 patients followed in the pandemic services across Turkey between January 1,2021,and March 31,2022 were investigated retrospectively.Nosocomial COVID-19 was defined as a patient neither diagnosed with COVID-19 nor suspected COVID-19 at the hospital admission and was confirmed COVID-19≥5 days after hospital admission.The primary outcome of this study was in-hospital mortality;demographic features and vaccination status was compared between survivors and non-survivors.Results:During the study period,15573 COVID-19 patients were followed in 18 centers and 543(3.5%)patients were nosocomial COVID-19.Most patients with nosocomial COVID-19(80.4%)were transferred from medical wards.162(29.8%)of the patients with nosocomial COVID-19 admitted to the intensive care unit due to disease severity and 138(25.4%)of the patients died during hospital stay.Advanced age(≥65 years)and number of comorbid diseases(≥2)was found to be associated with mortality in nosocomial COVID-19(OR 1.74,95%CI 1.11-2.74 and OR 1.60,95%CI 1.02-2.56,respectively).Vaccination was associated with survival in nosocomial COVID-19(OR 0.25,95%CI 0.16-0.38).Conclusions:Patients with nosocomial COVID-19 had increased admission to intensive care units and higher mortality rate.Vaccination can decrease the in-hospital mortality rate. 展开更多
关键词 COVID-19 Nosocomial infection VACCINATION Intensive care unit
下载PDF
Review of a challenging clinical issue:Intrahepatic cholestasis of pregnancy 被引量:57
14
作者 Sebiha Ozkan Yasin Ceylan +1 位作者 Orhan Veli Ozkan Sule Yildirim 《World Journal of Gastroenterology》 SCIE CAS 2015年第23期7134-7141,共8页
Intrahepatic cholestasis of pregnancy(ICP) is a reversible pregnancy-specific cholestatic condition characterized by pruritus, elevated liver enzymes, and increased serum bile acids. It commences usually in the late s... Intrahepatic cholestasis of pregnancy(ICP) is a reversible pregnancy-specific cholestatic condition characterized by pruritus, elevated liver enzymes, and increased serum bile acids. It commences usually in the late second or third trimester, and quickly resolves after delivery. The incidence is higher in South American and Scandinavian countries(9.2%-15.6% and 1.5%, respectively) than in Europe(0.1%-0.2%). The etiology is multifactorial where genetic, endocrine, and environmental factors interact. Maternal outcome is usually benign, whereas fetal complications such as preterm labor, meconium staining, fetal distress, and sudden intrauterine fetal demise not infrequently lead to considerable perinatal morbidity and mortality. Ursodeoxycholic acid is shown to be the most efficient therapeutic agent with proven safety and efficacy. Management of ICP consists of careful monitoring of maternal hepatic function tests and serum bile acid levels in addition to the assessment of fetal well-being and timely delivery after completion of fetal pulmonary maturity. This review focuses on the current concepts about ICP based on recent literature data and presents an update regarding the diagnosis and management of this challenging issue. 展开更多
关键词 INTRAHEPATIC CHOLESTASIS PREGNANCY DIAGNOSIS Management
下载PDF
Endoscopic submucosal dissection for premalignant lesions and noninvasive early gastrointestinal cancers 被引量:23
15
作者 Sadettin Hulagu Omer Senturk +16 位作者 Cem Aygun Orhan Kocaman Altay Celebi Tolga Konduk Deniz Koc Goktug Sirin Ugur Korkmaz Ali Erkan Duman Neslihan Bozkurt Gokhan Dindar Tan Attila Yesim Gurbuz Orhan TarcinDivision of Gastroenterology Derince State Hospital Kocaeli 41900 Turkey Cem Kalayci 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第13期1701-1709,共9页
AIM: To investigate the indication, feasibility, safety, and clinical utility of endoscopic submucosal dissection (ESD) in the management of various gastrointestinal pathologies. METHODS: The medical records of 60 con... AIM: To investigate the indication, feasibility, safety, and clinical utility of endoscopic submucosal dissection (ESD) in the management of various gastrointestinal pathologies. METHODS: The medical records of 60 consecutive patients (34 female, 26 male) who underwent ESD at the gastroenterology department of Kocaeli University from 2006-2010 were examined. Patients selected for ESDhad premalignant lesions or non-invasive early cancers of the gastrointestinal tract and had endoscopic and histological diagnoses. Early cancers were considered to be confined to the submucosa, with no lymph node involvement by means of computed tomography and endosonography. RESULTS: Sixty ESD procedures were performed. The indications were epithelial lesions (n = 39) (33/39 adenoma with high grade dysplasia, 6/39 adenoma with low grade dysplasia), neuroendocrine tumor (n = 7), cancer (n = 7) (5/7 early colorectal cancer, 2/7 early gastric cancer), granular cell tumor (n = 3), gastrointestinal stromal tumor (n = 2), and leiomyoma (n = 2). En bloc and piecemeal resection rates were 91.6% (55/60) and 8.3% (5/60), respectively. Complete and incomplete resection rates were 96.6% (58/60) and 3.3% (2/60), respectively. Complications were major bleeding [n = 3 (5%)] and perforations [n = 5 (8.3%)] (4 colon, 1 stomach). Two patients with colonic perforations and two patients with submucosal lymphatic and microvasculature invasion (1 gastric carcinoid tumor, 1 colonic adenocarcinoma) were referred to surgery. During a mean follow-up of 12 mo, 1 patient with adenoma with high grade dysplasia underwent a second ESD procedure to resect a local recurrence. CONCLUSION: ESD is a feasible and safe method for treatment of premalignant lesions and early malignant gastrointestinal epithelial and subepithelial lesions. Successful en bloc and complete resection of lesions yield high cure rates with low recurrence. 展开更多
关键词 Endoscopic submucosal dissection Premalignant gastrointestinal lesion Noninvasive early gastrointestinal cancer Neuroendocrine tumor Gastrointestinal stromal tumor
下载PDF
Influence of Cu addition on microstructure and hardness of near-eutectic Al-Si-xCu-alloys 被引量:10
16
作者 MUZAFFER ZEREN ERDEM KARAKULAK SERAP GüMü 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1698-1702,共5页
The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu(x = 2%,3%,4% and 5%) was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand... The influence of Cu content on the microstructure and hardness of near-eutectic Al-Si-xCu(x = 2%,3%,4% and 5%) was investigated.After melting Al-based alloys with different Cu contents,alloys were cast in green sand molds at 690 °C and solidified.The solution treatment was performed at 500 °C for 7 h and then the specimens were cooled by water quenching.The samples were respectively aged at 190 °C for 5,10 and 15 h to observe the effect of aging time on the hardness of matrix.Also differential thermal analysis was used to obtain the transition temperature of the equilibrium phases at cooling rate of 30 K/min and to determine the effect of Cu content on the formation of quaternary eutectic phases and the melting point of-(Al) + Si.The results show that as Cu content in the alloy increases,the hardness of matrix increases due to precipitation hardening,the melting point of -(Al) + Si decreases and the amount of these eutectic phases increases,quaternary eutectic phase with melting point of 507 -C forms when Cu content is more than 2%. 展开更多
关键词 near-eutectic Al-Si-xCu-alloys Cu content DTA HARDNESS
下载PDF
Endoscopic retrograde cholangiopancreatography during pregnancy without radiation 被引量:17
17
作者 Adem Akcakaya Orhan Veli Ozkan +2 位作者 Ismail Okan Orhan Kocaman Mustafa Sahin 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第29期3649-3652,共4页
AIM: To present our experience with pregnant patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) without using radiation, and to evaluate the acceptability of this alternative therapeutic p... AIM: To present our experience with pregnant patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) without using radiation, and to evaluate the acceptability of this alternative therapeutic pathway for ERCP during pregnancy. METHODS: Between 2000 and 2008, six pregnant women underwent seven ERCP procedures. ERCP was performed under mild sedoanalgesia induced with pethidine HCI and midazolam. The bile duct was cannulated with a guidewire through the papilla. A catheter was slid over the guidewire and bile aspiration and/or visualization of the bile oozing around the guidewire was used to confirm correct cannulation. Following sphincterotomy, the bile duct was cleared by balloon sweeping. When indicated, stents were placed. Confirmation of successful biliary cannulation and stone extraction was made by laboratory, radiological and clinical improvement. Neither fluoroscopy nor spot radiography was used during the procedure. RESULTS: The mean age of the patients was 28 years (range, 21-33 years). The mean gestational age for the fetus was 23 wk (range, 14-34 wk). Five patients underwent ERCP because of choledocholithiasis and/or choledocholithiasis-induced acute cholangitis. In one case, a stone was extracted after precut papillotomy with a needle-knife, since the stone was impacted. One patient had ERCP because of persistent biliary fistula after hepatic hydatid disease surgery. Following sphincterotomy, scoleces were removed from the common bile duct. Two weeks later, because of the absence of fistula closure, repeat ERCP was performed and a stent was placed. The fistula was closed after stent placement. Neither post-ERCP complications nor premature birth or abortion was seen. CONCLUSION: Non-radiation ERCP in experienced hands can be performed during pregnancy. Stent placement should be considered in cases for which complete common bile duct clearance is dubious because of a lack of visualization of the biliary tree. 展开更多
关键词 CHOLANGITIS CHOLEDOCHOLITHIASIS Endoscopic retrograde cholangiopancreatography JAUNDICE PREGNANCY
下载PDF
Coexistence of acute myocardial infarction with normal coronary arteries and migraine with aura in a female patient 被引量:6
18
作者 Umut Celikyurt Goksel Kahraman Ender Emre 《World Journal of Cardiology》 CAS 2011年第7期260-262,共3页
Acute myocardial infarction with normal coronary arteries is a well known condition,which is typically diagnosed in young patients.Coronary vasospasm,inherited,acquired or malignancy-induced hypercoagulable state,coll... Acute myocardial infarction with normal coronary arteries is a well known condition,which is typically diagnosed in young patients.Coronary vasospasm,inherited,acquired or malignancy-induced hypercoagulable state,collagen vascular disease and coronary arterial embolism have been considered as underlying etiologic factors.An association between migraine with aura and increased risk of ischemic stroke,angina and myocardial infarction has been demonstrated in studies.Patients with migraine and especially with aura should be followed closely against cardiovascular events even if they are young and do not have traditional risk factors. 展开更多
关键词 Acute myocardial INFARCTION AURA MIGRAINE Normal coronary ARTERIES
下载PDF
Clindamycin-induced acute cholestatic hepatitis 被引量:6
19
作者 Cem Aygün Orhan Kocaman +2 位作者 Yesim Gürbüz mer Sentürk Sadettin Hülagü 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第40期5408-5410,共3页
We report a case of acute hepatotoxicity in a 42-yearold woman after administration of clindamycin for a dental infection. After 6 d of treatment, she had fatigue, nausea, vomiting, anorexia, pruritus and jaundice. He... We report a case of acute hepatotoxicity in a 42-yearold woman after administration of clindamycin for a dental infection. After 6 d of treatment, she had fatigue, nausea, vomiting, anorexia, pruritus and jaundice. Her laboratory analysis showed alanine aminotransferase (ALT), 1795 IU/L (normal range 0-40); aspartate aminotransferase (AST), 1337 IU/L (normal range 5-34); alkaline phosphatase (ALP), 339 IU/L (normal range 40-150); 7-glutamyl transpeptidase (GGT), 148 IU/L (normal range 9-64 IU/L); total bilirubin, 4.1 mg/dL; direct bilirubin, 2.9 mg/dL and prothrombin time (PT), 13.5 s, with international normalized ratio (INR), 1.04. She was hospitalized, with immediate drug discontinuation. Her liver biopsy specimen showed mixed-type (both hepatocellular and cholestatic) hepatic injury, compatible with a diagnosis of drug-induced hepatitis. An objective causality assessment using the Naranjo probability scale suggested that clindamycin was the probable cause of the acute hepatitis. In susceptible individuals, clindamycin use may lead to acute mixedtype liver toxicity. Complete recovery may be possible if the drug is discontinued before severe liver injury is established. 展开更多
关键词 CLINDAMYCIN Hepatic injury HEPATITIS
下载PDF
Mechanical lithotripsy and/or stenting in management of difficult common bile duct stones 被引量:6
20
作者 Adem Akcakaya Orhan Veli Ozkan +4 位作者 Gurhan Bas Atilla Karakelleoglu Orhan Kocaman Ismail Okan Mustafa Sahin 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2009年第5期524-528,共5页
BACKGROUND:Mechanical lithotripsy and/or stent insertion is the alternative therapeutic approach in difficult endoscopic retrograde cholangiopancreatography (ERCP)case.This study was designed to investigate the approp... BACKGROUND:Mechanical lithotripsy and/or stent insertion is the alternative therapeutic approach in difficult endoscopic retrograde cholangiopancreatography (ERCP)case.This study was designed to investigate the appropriate treatment for extraction of bile duct stones in difficult cases of ERCP. METHODS:Between 2000 and 2008,744 ERCP procedures were performed in 592 patients with choledocholithiasis in our endoscopy unit.The demographic features,and clinical and laboratory findings were collected from a prospectively held database.Bile duct calculi were extracted by basket and/or balloon catheter following ERCP and sphincterotomy.Patients with retained stones were regarded as difficult cases.These patients were treated with mechanical lithotripsy and those with incomplete clearance of stones underwent stent placement. RESULTS:Two hundred and forty-five patients(41%) were male and 347(59%)were female with a mean age of 58 years(range 19-95 years).Stones were impacted in 27 patients(5%).Stone extraction was performed by basket and/or balloon catheter in 610 ERCP procedures,and lithotripsy was performed in 70 ERCP procedures.Forty- four patients underwent stent insertion,and 20 underwent stent replacement.Morbidity occurred in 39 patients (5%),with no mortality associated with the procedure.Hemorrhage occurred in 9 patients and basket impaction in 4.Mild pancreatitis and cholangitis developed in 12 and 11 patients,respectively. CONCLUSION:Difficult cases of bile duct stones can be treated successfully with lithotripsy,and a stent should be applied when the common bile duct cannot be cleared completely. 展开更多
关键词 common bile duct stone endoscopic retrograde cholangiopancreatography stone extraction mechanical lithotripsy STENTING
下载PDF
上一页 1 2 6 下一页 到第
使用帮助 返回顶部