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Antifouling Properties of Electrospun Polymeric Coatings Induced by Controlled Surface Morphology

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Energy & Environmental Materials 2024年第6期7卷 409-419页

作者： Fabio L.Favrin Lorenzo Zavagna Matteo Sestini semih Esin Bahareh Azimi Massimiliano Labardi Mario Milazzo Giuseppe Gallone Giovanna Batoni Serena Danti Department of Civil and Industrial Engineering University of PisaLargo Lucio Lazzarino 256122PisaItaly Department of Translational Research and New Technologies in Medicine and Surgery University of Pisavia San Zeno 35-3956123PisaItaly Institute for Chemical and Physical Processes(IPCF) National Research Council(CNR)Pisa Research AreaVia Moruzzi 156124PisaItaly Department of Civil and Environmental Engineering Massachusetts Institute of Technology(MIT)Massachusetts Ave.77CambridgeMassachusetts 02139USA

Nosocomial infections affect implanted medical devices and greatly challenge their functional outcomes,becoming sometimes life threatening for the ***,aggressive antibiotic therapies are administered,which often require the use of last-resort drugs,if the infection is caused by multi-drug-resistant *** the risk of bacterial contamination of medical devices in the hospitals has thus become an emerging *** routes to control these infections are based on materials provided with intrinsic bactericidal properties(i.e.,chemical action)and on the design of surface coatings able to limit bacteria adhesion and fouling phenomena(i.e.,physical action),thus preventing bacterial biofilm ***,we report the development and validation of coatings made of layer-by-layer deposition of electrospun poly(vinylidene fluoride-co-trifluoro ethylene)P(VDF-TrFE)fibers with controlled orientations,which ultimately gave rise to antifouling *** obtained 10-layer surface morphology with 90°orientation fibers was able to efficiently prevent the adhesion of bacteria,by establishing a superhydrophobic-like behavior compatible with the Cassie-Baxter ***,the results highlighted that surface wettability and bacteria adhesion could be controlled using fibers with diameter comparable to bacteria size(i.e.,achievable via electrospinning process),by tuning the intra-fiber spacing,with relevant implications in the future design of biomedical surface coatings.

关键词： additive manufacturing Escherichia coli fibers Poly(vinylidene fluoride-cotrifluoro ethylene)P(VDF-TrFE) Pseudomonas aeruginosa superhydrophobic

An Efficient Parallel Solution Framework for the Linear Solution of Large Systems on PC Clusters

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Tsinghua Science and Technology 2008年第S1期13卷 65-70页

作者： Ozgur Kurc semih Ozmen Structural Mechanics Laboratory Department of Civil Engineering Middle East Technical University

In this paper, a parallel solution framework for the linear static analysis of large structures on PC clusters is presented. The framework consists of two main steps: data preparation and parallel solution. The parallel solution is performed by a substructure based method with direct solvers. The aim of the data preparation step is to create the best possible substructures so that the parallel solution time is minimized. An actual structural model was solved utilizing both homogeneous and heterogeneous PC clusters to illustrate the performance and applicability of the presented framework.

关键词： substructure parallel solution heterogeneous clusters homogeneous clusters workload bal-ancing partitioning repartitioning

Microstructure, mechanical properties and formability of friction stir welded dissimilar materials of IF-steel and 6061 Al alloy

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International Journal of Minerals,Metallurgy and Materials 2019年第6期26卷 722-731页

作者： semih Mahmut Aktarer Dursun Murat Sekban Tevfik Kucukomeroglu Gencaga Purcek Department of Automotive Technology Recep Tayyip Erdogan UniversityRize 53020Turkey Department of Naval Architecture and Marine Engineering Karadeniz Technical UniversityTrabzon 61530Turkey Department of Mechanical Engineering Karadeniz Technical UniversityTrabzon 61080Turkey

AA 6061 alloy and interstitial-free(IF)steel plates were joined by the friction stir welding(FSW)method,and the microstructure,mechanical properties,and biaxial stretch formability of the friction stir welded(FSWed)parts were *** results indicate that the FSWed parts showed optimum tensile strength during FSW with the 0.4-mm offset position of the *** Fe4Al13 intermetallic compound formed in the defect-free intersection of AA 6061 and IF-steel plates during *** hardness of the IF-steel part of the FSWed region increased almost 90%relative to its initial hardness of HV0.2 *** tensile and yield strengths of FSWed regions were approximately 170 MPa and 145 MPa,*** to the formability tests,the Erichsen Index(EI)of the IF-steel,AA 6061,and the FSWed samples were determined to be 2.9 mm,1.9 mm,and 2.1 mm,*** EI of the FSWed sample was almost the same as that of the AA 6061 ***,it decreased compared with that of the *** force at EI(FEI)was approximately 1180 N for the FSWed *** value is approximately 70%higher than that of AA 6061 alloy.

关键词： friction stir welding IF-steel aluminum alloy microstructure mechanical properties formability

Microstructure and mechanical properties of friction-stir welded St52 steel joints

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International Journal of Minerals,Metallurgy and Materials 2018年第12期25卷 1457-1464页

作者： Tevfik kucukomeroglu semih M.Aktarer Guven Ipekoglu Gurel Cam Department of Mechanical Engineering Karadeniz Technical UniversityTrabzon 61080Turkey Department of Automotive Technology Recep Tayyip Erdogan UniversityRize 53100Turkey Department of Mechanical Engineering Iskenderun Technical UniversityHatay 31200Turkey

The aim of this work is to investigate the mechanical properties and microstructures of friction-stir welded(FSWed) St52 structural steel joints. In this study, St52 steel plates with a thickness of 4 mm were butt-welded by friction-stir welding(FSW) using a tungsten carbide tool having a conical pin. The microstructure of the welded zone consists of equiaxed fine ferrite, grain boundary ferrite, Widmanstatten ferrite, and aggregates of ferrite + cementite. The microhardness measurements showed that the hardness of the welded zone was significantly higher than that of the base metal. The FSWed St52 joint exhibited a significant strength overmatching in the weld region and a strength performance similar to or slightly higher than that of the base plate.

关键词： friction-stir welding St52 steel microstructure mechanical properties

H pylori infection in patients with Behcet's disease

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World Journal of Gastroenterology 2007年第21期13卷 2983-2985页

作者： Osman Ersoy Reyhan Ersoy Ozlem Yayar Huseyin Demirci semih Tatlican Department of Gastroenterology Hacettepe University Faculty of MedicineAnkaraTurkey Department of Endocrinology Ankara Ataturk Education and Research HospitalAnkaraTurkey Department of Internal Medicine Ankara Diskapi Education and Research HospitalAnkaraTurkey Department of Dermatology Ankara Diskapi Education and Research HospitalAnkaraTurkey

AIM:To evaluate endoscopic findings and the prevalence of H pylori in patients with Behcet's disease (BD) who have upper gastrointestinal symptoms. METHODS:The patients with BD diagnosed according to the International Study Group and followed up in the Department of Dermatology and other related departments and who had any upper gastrointestinal complaints,were included in this study. Forty-five patients with BD and 40 patients in the control group were evaluated by upper gastrointestinal endoscopy and two biopsied specimens were taken during endoscopy for H pylori . A two-week triple therapy for H pylori eradication was administered to H pylori positive patients. Two months after the treatment,the patients were evaluated by urea-breath test for eradication control. RESULTS:Patients with BD had a mean age of 36.2 ± 11.4 years (18-67 years). The mean follow-up time was 35 ± 14 mo (16-84 mo). Aphthous or deep ulcer in esophagus,stomach and duodenum had never been confirmed by endoscopic examination. Most gastric lesions were gastric erosion (40%) and the most duodenal lesions were duodenitis (17.5%) in two groups. H pylori was positive in 33 patients (73.3%) with BD. The two-week triple eradication therapy was successful in 75% of the patients. There was no difference between the groups in respect to prevalence of H pylori (73.3% vs 75%,P > 0.05),and eradication rate (75% vs 70%,P > 0.05). CONCLUSION:Endoscopic findings,eradication rate and prevalence of H pylori were similar in patients withBD and control group.

关键词： Hpylori Behcet's disease Vasculitis endoscopic findings aphthous ulcer

Potential neoplastic effects of parathion-methyl on rat liver

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Journal of Environmental Sciences 2009年第5期21卷 696-699页

作者： M. Nisa Unaldi Coral1 Sonay Ucman Hasan Yildiz Haydar Oztas semih Dalkilic Mersin University Education Faculty Yenisehir Campus 33169 Mersin Turkey Mustafa Kemal University Arts and Science Faculty Department of Biology Tayfur Sokmen Campus Selcuk University Education Faculty Biology Education Konya Ankara University Biotechnology Institution Ankara

The mutagenic and carcinogenic effects of parathion-methyl were examined by bacterial reverse mutation assay and a long-term experiment with wistar rats. The potential mutagenic effect of parathion-methyl in Salmonella typhimurium TA100 bacterial cells was observed without rat liver S9 metabolic activation. Parathion-methyl was further investigated for pathological changes in rat pancreas and liver. The long-term rat experiments showed that parathion-methyl exposure for 3 months can cause pathological changes in rat pancreases acinar cells and pancreatic hepatocytes. Atypical acinar cell focuses （AACF） were determined in the liver and pancreas of the rats. The results from short-term Ames test and long-term rat experiments suggested that parathion-methyl would be potential carcinogenic.

关键词： atypical acinar cell focuses Ames test carcinogenesis parathion-methyl

Accurate positioning of the 24-hour pH monitoring catheter:Agreement between manometry and pH step-up method in two patient positions

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World Journal of Gastroenterology 2007年第46期13卷 6197-6202页

作者： Mehmet Fatih Can Gokhan Yagci Sadettin Cetiner Mustafa Gulsen Taner Yigit Erkan Ozturk semih Gorgulu Turgut Tufan Departments of General Surgery Gulhane Military Medical AcademyEtlikAnkaraTurkey "Reflux Research Group"Gulhane Military Medical AcademyEtlikAnkaraTurkey Gastoenterology and Hepatology Gulhane Military Medical AcademyEtlikAnkaraTurkey "Reflux Research Group"Gulhane Military Medical AcademyEtlikAnkaraTurkey Departments of General Surgery Gulhane Military Medical AcademyEtlikAnkaraTurkey

AIM： TO investigate the agreement between esophageal manometry and pH step-up method in two different patient positions. METHODS： Eighteen subjects were included in the study. First, the distance from the nose to the proximal border of the lower esophageal sphincter （LES） was measured manometrically. Then a different investigator, who was blinded to the results of the first study, measured the same distance using the pH step-up method, with the patient in both upright and supine positions. An assessment of agreement between the two techniques was performed. RESULTS： In the supine position, the measurement of only one subject was outside the range accepted for correct positioning （~〈 3 cm distal or proximal to the LES）. In the upright position, errors in measurement were recognized in five subjects. Bland-Airman plots revealed good agreement between measurements obtained manometrically and by the pH-step up method with the patient in the supine position. CONCLUSION： In the case of nonavailability of manometric detection device, the pH step-up method can facilitate the positioning of the 24 h pH monitoring catheter with the patient in the supine position. Thisshould increase the use of pH-metry in clinical practice for subjects with suspected gastroesophageal reflux disease if our results are supported by further studies.

关键词： pH monitoring Esophageal manometry pHstep-up method Gastroesophageal reflux

Comparison of Low Rise Residential Industrialized Building Systems in Turkey

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Journal of Literature and Art Studies 2012年第9期2卷 864-871页

作者： semih Goksel Yildirim Istanbul Arel University Istanbul Turkey

Industrialized building systems came into the agenda in response to requirements of earthquake resistance and rapid construction in Turkey after 1999 Izmit earthquake. CFS （cold-formed steel） framing system is able to meet the existing requirements in the field of low rise residential. But, objective comparison is required for the selection of structural systems used in low rise residentials. CFS system is compared with timber frame and reinforced concrete building systems in terms of design and applicability criterion in circumstances of Turkey, and the results of this comparison are presented in this study. In order to compare building systems objectively, a sample project, has been designed and studied on it. Three structural systems have been separately applied over this project designed in consideration of existing housing stock and preferences of the construction industry of Turkey Evaluation method with different values is selected in comparison and properties of three different structural systems are graded according to evaluation method. As a result of comparison, the CFS system is the most advantageous low rise residential prefabricated construction system in terms of design and applicability

关键词： low rise residential industrialization prefabricated reinforced concrete system CFS (cold-formed steel)frame timber frame

In vitro cytotoxic effects of Smilax aspera *** on cancer cell lines

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Food Bioscience 2022年第2期46卷 890-899页

作者： semih Dalkılıç Ismail Korkmaz Lütfiye Kadıo˘glu Dalkılıç Gokhan Akay Songül Fidan Department of Biology Faculty of ScienceFirat University23000ElazıgTurkey

Approximately,14 million cancer cases are seen annually,and cancer accounts for 20%of all deaths in the ***,the incidence of cancer is increasing every *** fact that the survival rate in cancer is not at the desired level makes cancer a pathology with a high mortality *** conduct intensive research on strategic issues such as new diagnostic methods,identification of new candidate drug molecules,and detection of molecules or molecular pathways that may be targeted for new *** this study;The cytotoxic activity and apoptotic mechanism were investigated root extracts of Smilax aspera L.,whose roots are *** study,cytotoxicity of *** root extracts on MDA-MB-231,A549 and OVCAR3 cell lines by MTT method and apoptotic activity on OVCAR3 cell line by double staining and gene expression levels were determined for the first *** a result of the study,*** root extracts showed a significant cytotoxic effect on three cell lines at different *** addition,it suppressed the BCL2 gene,which has an important role in the prevention of apoptosis,and it was determined to have an apoptosis-inducing *** this respect,it is seen that *** is a strategically important plant that can be used in cancer treatment.

关键词： Apoptosis Cytotoxicity Gene expression Smilax aspera