检索结果-南通市图书馆

Circuits and Systems 2011年第3期2卷 249-259页

作者： nihal Kularatna Chandani Jindasa 不详

A series connected power semiconductor array, with digital control capability could be used for developing single phase AC regulators or other applications such as AC electronic loads. This technique together with an ordinary gapless transformer could be used to develop a low cost AC voltage regulator (AVR) to provide better or comparable specifications with bulky ferro-resonant AVR types. One primary advantage of the technique is that digital control can be used to minimize harmonics. Commencing with a review of AC voltage regulator techniques for single phase power conditioning systems, an analysis and design aspects of this technique is presented with experimental results for AVRs. Guidelines on how to utilize the technique in a generalized basis is also summarized together with a summary of a technique for achieving harmonic control.

关键词： Power Conditioners AC Voltage Regulators (AVR) Power Semiconductors Digital Control Electronic AC Loads

Gene expression and histopathological evaluation of thiamine pyrophosphate on optic neuropathy induced with ethambutol in rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2016年第10期9卷 1390-1395页

作者： Emine Cinici nihal Cetin Bahadir Suleyman Durdu Altuner Oguzhan Yarali Hilal Balta Ilknur Calik Levent Tumkaya Halis Suleyman Department of Ophthalmology Erzurum Region Education and Research Hospital Department of Pharmacology Faculty of MedicineErzincan University Department of Medical Genetics Goztepe Training and Research HospitalIstanbul Medeniyet University Department of Pathology Erzurum Region Education and Research Hospital Department of Histology and Embryology Faculty of MedicineRecep Tayyip Erdogan University

AIM： To compare the effects of thiamine pyrophosphate（TPP） and thiamine（TM） in oxidative optic neuropathy in rats induced by ***： The animals were divided into four groups：a control group（CG）,an ethambutol control（ETC） group,TM plus ethambutol group（TMG）,and TPP plus ethambutol group（TPPG）.One hour after intraperitoneal administration of TM 20 mg/kg to the TMG group and TPP 20 mg/kg to TPPG group,30 mg/kg ethambutol was given via gavage to all the groups but the *** procedure was repeated once daily for 90 *** that period,all rats were exposed to high levels of anaesthesia in order to investigate the gene expression of malondialdehyde and glutathione in removed optic nerve tissue and histopathologically to examine these tissues. RESULTS： Malondialdehyde gene expression significantly increased,whereas glutathione gene expression significantly decreased in the ETC group compared to the *** could not prevent the increase of malondialdehyde gene expression and the decrease of glutathione,while TPP significantly could ***,significant vacuolization in the opticnerve,single-cell necrosis in the glial cells,and a decrease in oligodendrocytes were observed in the ETC *** in the optic nerve,a decrease in oligodendrocytes and single-cell necrosis were found in the TMG group,while no pathological finding was observed in the TPPG group except for mild ***： TPP protects the optic nerve against the ethambutol-induced toxicity but TM does *** can be beneficial in prophilaxis of optic neuropathy in ethambutol therapy.

关键词： ethambutol gene expression optic neuropathy rat thiamine pyrophosphate

Some Mixed Soft Operations and Extremally Soft Disconnectedness via Two Soft Topologies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2014年第3期5卷 490-500页

作者： nihal Arabacioglu Tas Ahu Acikgoz Department of Mathematics Balikesir UniversityBalikesirTurkey

In this paper, we study the concept of soft sets which is introduced by Molodtsov [5]. We give the definition of (τ1,τ2)-semi open soft (resp. (τ1,τ2)-pre open soft, (τ1,τ2)-α-open soft, (τ1,τ2)-β-open soft, (τ1,τ2)'-semi open soft, (τ1,τ2)'-pre open soft, (τ1,τ2)'-α-open soft, (τ1,τ2)'-βopen soft) set via two soft topologies. Also we introduce (τ1,τ2)-regular open soft and ESDC on two soft topologies. The aim of this paper is to investigate properties of some mixed soft operations and characterizations of ESDC. Finally, we study τ2-ESDC soft topologies τ1.

关键词： (τ1,τ2)-Semi Open Soft (τ1,τ2)-Pre Open Soft (τ1,τ2)-α-Open Soft (τ1,τ2)-β-Open Soft (τ1,τ2)'-Semi Open Soft (τ1,τ2)'-Pre Open Soft (τ1,τ2)'-α-Open Soft (τ1,τ2)'-β-Open Soft (τ1,τ2)-Regular Open Soft ESDC

An Improved Method for Automatic Retinal Blood Vessel Vascular Segmentation Using Gabor Filter

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Medical Imaging 2015年第4期5卷 204-213页

作者： Nalan Karunanayake nihal D. Kodikara Department of Electrical and Computer Engineering Sri Lanka Institute of Information Technology Malabe Sri Lanka Department of Computer Science University of Colombo School of Computing Colombo Sri Lanka

Early detection of Non-Proliferative Diabetic Retinopathy (NDPR) is currently a highly interested research area in biomedical imaging. Ophthalmologists discover NDPR by observing the configuration of the vessel vascular network deliberately. Therefore, a computerized automatic system for the segmentation of vessel system will be an assist for ophthalmologists in order to detect an early stage of retinopathy. In this research, region based retinal vascular segmentation approach is suggested. In the steps of processing, the illumination variation of the fundus image is adjusted by using the point operators. Then, the edge features of the vessels are enhanced by applying the Gabor Filter. Finally, the region growing method with automatic seed point selection is used to extract the vessel network from the image background. The experiments of the proposed algorithm are conducted on DRIVE dataset, which is an open access dataset. Results obtain an accuracy of 94.9% over the dataset that has been used.

关键词： Diabetic Retinopathy Blood Vessel Segmentaion Retinul Fundus Image Gabor Filter Region Growing Point Operators Illumination Variation

Generalized Maximum Fuzzy Entropy Methods with Applications on Wind Speed Data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mathematics and System Science 2016年第1期6卷 46-52页

作者： Aladdin Shamilov Sevil Senturk nihal Yilmaz Faculty of Science Department of Statistics Anadolu University 26470 Eskisehir Turkey.

This study is connected with new Generalized Maximum Fuzzy Entropy Methods （GMax（F）EntM） in the form of MinMax（F）EntM and MaxMax（F）EntM belonging to us. These methods are based on primary maximizing Max（F）Ent measure for fixed moment vector function in order to obtain the special functional with maximum values of Max（F）Ent measure and secondary optimization of mentioned functional with respect to moment vector functions. Distributions, in other words sets of successive values of estimated membership function closest to （furthest from） the given membership function in the sense of Max（F）Ent measure, obtained by mentioned methods are defined as （MinMax（F）Ent）m which is closest to a given membership function and （MaxMax（F）Ent）m which is furthest from a given membership function. The aim of this study consists of applying MinMax（F）EntM and MaxMax（F）EntM on given wind speed data. Obtained results are realized by using MATLAB programme. The performances of distributions （MinMax（F）En0m and （MaxMax（F）Ent）m generated by using Generalized Maximum Fuzzy Entropy Methods are established by Chi-Square, Root Mean Square Error criterias and Max（F）Ent measure.

关键词： Maximum fuzzy entropy measure Generalized maximum fuzzy entropy methods Moment vector functions Membership function.

Trace elements in diabetic cardiomyopathy:An electrophysiological overview

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Diabetes 2013年第4期4卷 92-100页

作者： nihal Ozturk Yusuf Olgar Semir Ozdemir Department of Biophysics Akdeniz University Faculty of Medicine

There is a growing body of evidence that Diabetes Mellitus leads to a specific cardiomyopathy apart from vascular disease and bring about high morbidity and mortality throughout the *** clinical and experimental studies have extensively demonstrated that this cardiomyopathy causes impaired cardiac performance manifested by early diastolic and late systolic *** impaired cardiac performance most probably have emerged upon the expression and activity of regulatory proteins such as Na+/Ca2+exchanger,sarcoplasmic reticulum Ca2+-ATPase,ryanodine receptor and *** years many therapeutic strategies have been recommended for treatment of diabetic ***,inorganic elements have been suggested to have anti-diabetic effects due to their suggested ability to regulate glucose homeostasis,reduce oxidative stress or suppress *** findings have shown that trace elements exert many biological effects including insulin-mimetic or antioxidant activity and in this manner they have been recommended as potential candidates for treatment of diabetes-induced cardiac complications,an effect based on their modes of *** of these trace elements are known to play an essential role as component of enzymes and thus modulate the organ function in physiological and pathological ***,they can also manipulate redox state of the channels via antioxidant properties and thus contribute to the regulation of [Ca2+]i homeostasis and cardiac ion *** account of little information about some trace elements,we discussed the effect of vanadium,selenium,zinc and tungstate on diabetic heart complications.

关键词： Diabetic cardiomyopathy Electrophysiology Trace elements Insulin-mimetic Antioxidant

Energy Performance Analysis of Ice Thermal Storage for Commercial HVAC Systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy and Power Engineering 2013年第9期7卷 1713-1718页

作者： Nabil Nassif Raymond Tesiero nihal AI Raees Department of Civil and Architeetural Engineering North Carolina A & T State University Greensboro NC 27411 USA

Ice thermal storage is a promising technology to reduce energy costs by shifting the cooling cost from on-peak to off-peak periods. The paper investigates the application of ice thermal storage and its impact on energy consumption, demand and total energy cost. Energy simulation software along with a chiller model is used to simulate the energy consumption and demand for the existing office building located in central Florida. Furthermore, the study presents a case study to demonstrate the cost saving achieved by the ice storage applications. The results show that although the energy consumption may increase by using ice thermal storage, the energy cost drops significantly, mainly depending on the local utility rate structure. It found that for the investigated system the annual energy consumption increases by about 12% but the annual energy cost drops by about 3 6%.

关键词： HVAC system ice thermal storage central plant chiller.

Evaluation of CA125 and NT-proBNP values in patients undergoing transcatheter aortic valve implantation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Geriatric Cardiology 2015年第2期12卷 100-106页

作者： Huseyin Ayhan Haca Ahmet Kasapkara Tahir Durmaz Telat Keles Cenk San Serdal Bastug Kemal Esref Erdogan nihal Akar Bayram Emine Bilen Murat Akgay Engin Bozkurt Faculty of Medicine Department of Cardiology Ytldtrtm Beyaztt University Ankara 06800 Turkey Department of Cardiology Ankara Ataturk Education and Research Hospital Ankara 06800 Turkey Faculty of Medicine Department of Cardiovascular Surgery Yddtrtm Beyaztt University Ankara 06800 Turkey

Background Transcatheter aortic valve implantation （TAVI） is a minimally invasive, emerging therapy in surgically high risk, or in- operable patients. Parameters used for risk classification have some deficiencies in the selection of patients. The objective of this study is to evaluate the impact of TAVI on carbohydrate antigen 125 （CA125） and N-terminal pro brain-type natriuretic peptide （NT-proBNP） as biomarkers that have been used frequently in recent years, and also the relationship of these biomarkers to prognosis. Methods ＆ Results Transcatheter aortic valve implantation was practiced on 31 patients in this study. Then, CA125 and NT-proBNP levels studied in patients prior to and after the TAVI were evaluated. The patients were also grouped in accordance with their left ventrieular ejection fraction （LVEF） and CA125 levels （LVEF 〉 40% and 〈 40%; CA125 ≤ 35 U/L and 〉 35 U/L）. The TAVI operation was successfully performed in all patients. There was no in-hospital mortality and substantial improvement in functional capacity was detected at follow ups. In addition, a statistically significant decrease was detected in post-TAVI CA 125 and NT-proBNP levels of all patients （CA 125 83.8 ± 18.1 U/L vs. 64.3 ±14.2 U/L, P = 0.008; NT-proBNP： 4633.6± 627.6 pg/mL vs. 2866.3±536.8 pg/mL, P 〈 0.001）. In groups divided according to the CA125 levels, there was also statistically significant post-TAVI decline in CA125 levels. Within CA125 〉 35 U/L and LVEF 〈 40% groups, the permanent need for a pacemaker was required in one （3.2%） patient and mortality was observed in two （6.4%） patients after TAVI at follow up. Conclusions The results show that TAVI can be performed effectively and reliably in patients with high baseline levels of CA125 and NT-proBNP. These biomarkers are reduced substantially with TAVI, while high biomarker levels are associated with undesired events, and certainly, these biomarkers can be used for risk classifications in patient selection for TAVI.

关键词： B-type natriuretic peptide Biomarker Carbohydrate antigen Heart failure Transcatheter aortic valve implantation Risk score

A New Characterization of Transformations by the Use of Apollonius Points of (2n-1)-gons

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2005年第3期21卷 667-672页

作者： Serap BULUT nihal YILMAZ Department of Mathematics Faculty of Arts and Science Balikesir University Balikesir 10100 Turkey

In this paper, we give a new characterization of Mobius transformations. To do this, we extend the notion of Apollonius points of a triangle and of a pentagon, to the notion of Apollonius points of an arbitrary （2n-1... 详细信息

关键词： Mobius transformations Apollonius points of (2n-1)-gons

Taxifolin attenuates ischemia-reperfusion induced oxidative ovarian damage in rats

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Asian pacific Journal of Reproduction 2021年第4期10卷 168-175页

作者： Sevil Kiremitli Tunay Kiremitli Umit Nayki Nesrin Yilmaz Can Turkler Kemal Dinc Renad Mammadov Gulce Naz Yazici Mine Gulaboglu nihal Cetin Erzincan Binali Yildirim University Faculty of Medicine Department of Obstetrics and GynaecologyErzincanTurkey Erzincan Binali Yildirim University Faculty of Medicine Department of PharmacologyErzincanTurkey Erzincan Binali Yildirim University Faculty of Medicine Department of Histology and EmbryologyErzincanTurkey Ataturk University Faculty of Pharmacy Department of BiochemistryErzurumTurkey Selcuk University Faculty of Medicine Department of PharmacologyKonyaTurkey

Objective:To investigate preventive effects of taxifolin on ischemia-reperfusion induced oxidative ovarian damage in ***:A total of 18 female Wistar albino rats were randomly and equally divided into three groups:the sham group,the ovarian ischemia reperfusion group,and the 50 mg/kg taxifolin+ovarian ischemia reperfusion *** ovarian ischemia reperfusion and taxifolin+ovarian ischemia reperfusion groups were exposed to ischemia for 2 h and then followed by two-hour reperfusion *** and histopathologic examinations were performed on the extracted ***:Levels of malondialdehyde and cyclooxygenase-2 were increased,while reduced-glutathione and cyclooxygenase-1 were decreased in the ovarian ischemia reperfusion ***,these values were reversed in the taxifolin+ovarian ischemia reperfusion ***,the number of primordial and developing follicules decreased in the ovarian ischemia reperfusion group,while they were within normal range in the taxifolin+ovarian ischemia reperfusion ***:Ischemia followed by reperfusion leads to oxidative stress-related ovarian injury,and taxifolin may be useful for protecting ovarian tissue from such injury.

关键词： Antioxidants Ischemia-reperfusion Ovarian damage Rat Taxifolin Oxidative stress Ovarian torsion