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An estimation of stress intensity factor in a clamped SE(T) specimen through numerical simulation and experimental verification:case of FCGR of AISI H11 tool steel

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Acta Metallurgica Sinica(English Letters) 2012年第4期25卷 307-319页

作者： Masood Shah Catherine Mabru Farhad rezai-Aria Ines Souki Riffat Asim Pasha Mechanical Engineering Department University of Engineering and TechnologyTaxilaPakistan Department of Mechanics of Structures and Materials University of Toulouse INSA UPSMines AlbiISA ICA(Institute Cl'ement Ader) DMSM F-31056 ToulouseFrance Research Group of Surfaces MachiningMaterials and ToolingUniversity of Toulouse INSA UPSMines AlbiISAE Campus Jarlard F-81013 Albi cedex 09France

A finite element analysis of stress intensity factors （KI） in clamped SE（T）c specimens （dog bone profile） is presented. A J-integral approach is used to calculate the values of stress intensity factors valid for 0.125≤a/W≤0.625. A detailed comparison is made with the work of other researchers on rectangular specimens. Different boundary conditions are explored to best describe the real conditions in the laboratory. A sensitivity study is also presented to explore the effects of variation in specimen position in the grips of the testing machine. Finally the numerically calculated SIF is used to determine an FCGR curve for AISI Hll tool steel on SE（T）c specimens and compared with C（T） specimen of the same material.

关键词： Fatigue crack propagation Stress intensity factor J-Integral Paris law

Effects of dieback on the vegetative, chemical, and physiological status of mangrove forests, Iran

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Journal of Arid Land 2023年第11期15卷 1391-1404页

作者： Vahid Farashi KAHNOUJ Marzieh rezai Rasool MAHDAVI Maryam MOSLEHI Saiedeh ESKANDARI Natural Resources Engineering Group Desert Management and ControlUniversity of HormozganHormozganBandarabass ***Iran Natural Resources Engineering Group Faculty of Agriculture and Natural ResourcesUniversity of HormozganHormozganBandarabass ***Iran Research Division of Natural Resources Hormozgan Agricultural and Natural Resources Research and Education CenterAgricultural ResearchEducation and Extension Organization(AREEO)Bandarabbas ***Iran Forest Research Division Research Institute of Forests and RangelandsAgricultural ResearchEducation and Extension Organization(AREEO)Tehran ***Iran

Mangrove forests are valuable resources in tropical and subtropical regions,which have been faced dieback due to various human activities including rapid expansion of shrimp farming,urban development,and pollution,as well as natural factors such as rising sea level,increasing air temperature,drought,and sharp decrease in ***,the mechanisms of dieback of mangrove forests are not well ***,this research aimed to assess the vegetative,chemical,and physiological status of grey mangrove(Avicennia marina(Forsk.)Vierh.)forests at different intensities of dieback in the Hormozgan Province,Iran.A total of 40 plots categorized into four dieback intensities(severe,medium,low,and control)were randomly selected for monitoring,and various parameters related to vegetative,chemical,and physiological status of grey mangrove forests were *** results revealed that the control group had the highest tree density,seedling density,vitality levels,aerial root density,and aerial root ***,as dieback severity increased,a decrease in demographic and vegetative parameters of trees and seedlings was observed in the dieback *** amounts of heavy metals(lead,cadmium,and nickel)in the sediment,roots,and leaves of grey mangrove trees at different dieback levels indicated that lead levels were the highest in the sediment,roots,and leaves in the severe dieback *** the same time,the control had the lowest *** concentrations in the sediment followed the pattern of severe dieback>moderate dieback>low dieback>control with no significant differences in the roots and *** amounts in all three parts,i.e.,sediment,roots,and leaves showed the highest levels in the severe dieback ***,metal level analysis in the organs of grey mangrove trees at different dieback levels revealed that lead and nickel were more abundant in the root organ compared with the *** contrast,the leaf organ exhibited the highes

关键词： nickel forests grey

Preliminary report of hepatitis B virus genotype prevalence in Iran

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World Journal of Gastroenterology 2006年第32期12卷 5211-5213页

作者： Seyed-Moayed Alavian Hossein Keyvani Mahdi rezai Neda Ashayeri Homa Mohammad Sadeghi Department of Internal Medicine Baqiatollah Medical University Tehran Hepatitis Center92 Vesal Shirazi StreetBoolvar KeshavarzPO Box 14155/3651TehranIran Department of Virology Iran University of Medical Sciences Hemmat ExpresswayTehranIran Student's Research Committee Iran University of Medical Sciences Hemmat ExpresswayTehranIran

AIM： To determine the prevalence of hepatitis B virus （HBV） genotypes in Iranian hepatitis B surface antigen （HBsAg） carriers, chronic hepatitis B and cirrhotic patients. METHODS： A total of 109 HBsAg-positive patients were included in this study. HBV genotypes were determined by using INNO-LiPA methodology which is based on the reverse hybridization principle. RESULTS： The distribution of patients with different stages of liver disease was as follows： 95 （86.4%） chronic hepatitis, 11 （10%） liver cirrhosis, and 3 （2.7%） inactive carrier. Of the chronic hepatitis and liver cirrhosis patients, 26.4% were HBeAg-positive while 70% were HBeAg-negative. Genotype D was the only detected type found in all patients. CONCLUSION： Classifying HBV into genotypes has to be cost-effective and clinically relevant. Our study indicates that HBV genotype D prevails in the Mediterranean area, Near and Middle East, and South Asia. Continued efforts for understanding HBV genotype through international co-operation will reveal further virological differences of the genotypes and their clinical relevance.

关键词： Hepatitis B virus Genotype Chronic Hepatitis B Cirrhosis

The simple two-step polydimethylsiloxane transferring process for high aspect ratio microstructures

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Journal of Semiconductors 2018年第8期39卷 81-84页

作者： Shaoxi Wang Dan Feng Chenxia Hu P.rezai School of Software &Microelectronics Northwestern Polytechnical University Department of Mechanical Engineering York University School of Chinese Meteria Medica Guangzhou University of Chinese Medicine

High aspect ratio units are necessary parts of complex microstructures in microfluidic devices. Some methods that are available to achieve a high aspect ratio require expensive materials or complex chemical processes; for other methods it is difficult to reach simple high aspect ratio structures, which need supporting structures. The paper presents a simple and cheap two-step Polydimethylsioxane(PDMS) transferring process to get high aspect ratio single pillars, which only requires covering the PDMS mold with a Brij@52 surface solution after getting a relative PDMS mold based on an SU8 mold. The experimental results demonstrate the method efficiency and effectiveness.

关键词： high aspect microfluidic chip microstructures

Hemodynamic monitoring during liver transplantation:A state of the art review

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World Journal of Hepatology 2015年第10期7卷 1302-1311页

作者： Mona rezai Rudnick Lorenzo De Marchi Jeffrey S Plotkin Department of Anesthesiology Georgetown University Hospital

Orthotopic liver transplantation can be marked by significant hemodynamic instability requiring the use of a variety of hemodynamic monitors to aide in intraoperative management. Invasive blood pressure monitoring is essential,but the accuracy of peripheral readings in comparison to central measurements has been questioned. When discrepancies exist,central mean arterial pressure,usually measured at the femoral artery,is considered more indicative of adequateperfusion than those measured peripherally. The traditional pulmonary artery catheter is less frequently used due to its invasive nature and known limitations in measuring preload but still plays an important role in measuring cardiac output(CO) when required and in the management of portopulmonary hypertension. Pulse wave analysis is a newer technology that uses computer algorithms to calculate CO,stroke volume variation(SVV) and pulse pressure variation(PPV). Although SVV and PPV have been found to be accurate predicators of fluid responsiveness,CO measurements are not reliable during liver transplantation. Transesophageal echocardiography is finding an increasing role in the realtime monitoring of preload status,cardiac contractility and the diagnosis of a variety of pathologies. It is limited by the expertise required,limited transgastric views during key portions of the operation,the potential for esophageal varix rupture and difficulty in obtaining quantitative measures of CO in the absence of tricuspid regurgitation.

关键词： Intraoperative monitoring Physiologicmonitoring Liver transplantation

Effect of crocin carotenoid on BDNF and CREB gene expression in brain ventral tegmental area of morphine treated rats

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Asian Pacific Journal of Tropical Biomedicine 2018年第8期8卷 387-393页

作者： Marzieh rezai Mehdi Mahmoodi Ayat Kaeidi Mojgan Noroozi Karimabad Alireza Khoshdel Mohammad Reza Hajizadeh Department of Clinical Biochemistry Faculty of Medicine Rafsanjan University of Medical Sciences Department of Clinical Biochemistry Afzalipoor Faculty of Medicine Kerman University of Medical Sciences Molecular Medicine Research Center Research Institute of Basic Medical Sciences Rafsanjan University of Medical Sciences Physiology-Pharmacology Research Center Research Institute of Basic Medical Sciences Rafsanjan University of Medical Sciences Department of Physiology and Pharmacology School of Medicine Rafsanjan University of Medical Sciences Department of Clinical Biochemistry Faculty of Medicine and Pistachio Safety Research Center Rafsanjan University of Medical Sciences

Objective: To investigate the effect of crocin carotenoid on BNDF and CREB gene expression in the brain ventral tegmental area(VTA) and the serum level of BDNF in morphine-treated rats compared to control. Methods: In this study, 40 male Wistar rats(200-250 g) were used in 5 experimental groups: 1) non morphine treat rats(control); 2) non morphine-treated rats with 25 mg/kg crocin carotenoid(i.p., for 21 d); 3) morphine treated rats(10 mg/kg twice a day, s.c., 21 d); 4 and 5) morphine-treated rats with 12.5 and 25 mg/kg crocin carotenoid, respectively. By the end of research, BDNF and CREB expression was determined by real-time-PCR method. ELISA analysis was also applied for assessing the serum BDNF level. Results: The data indicated that morphine treatment could cause a significant decrease in BDNF and CREB gene expression(P<0.01 and P<0.001, respectively) in brain VTA as well as serum level of BDNF(P<0.01) in comparison to control group. Treatment with 25 mg/kg crocin carotenoid caused a significant enhancement in BDNF and CREF gene expression(P<0.01 and P<0.05, respectively) and serum level of BDNF(P<0.01) in morphine-treated rats in comparison to morphine-treated group. Conclusions: Regarding to obtained results, crocin carotenoid can inhibit unfavorable effects of morphine on the neural system to some extent through enhancing BDNF and CREB gene expression in brain VTA and serum level of BDNF.

关键词： Morphine BDNF CREB Crocin Ventral tegmental area Rat

Polymeric vs hydroxyapatite-based scaffolds on dental pulp stem cell proliferation and differentiation

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World Journal of Stem Cells 2015年第10期7卷 1215-1221页

作者： Arash Khojasteh Saeed Reza Motamedian Maryam rezai Rad Mehrnoosh Hasan Shahriari Nasser Nadjmi Oral and Maxillofacial Surgery Dental Research CenterResearch Institute of Dental SciencesSchool of DentistryShahid Beheshti University of Medical Sciences Dental Research Center Research Institute of Dental SciencesSchool of DentistryShahid Beheshti University of Medical Sciences the Team for Cleft and Craniofacial Anomalies Oral and Maxillofacial SurgeryUniversity of Antwerp

AIM: To evaluate adhesion, proliferation and differentiation of human dental pulp stem cells(h DPSCs) on four commercially available scaffold biomaterials. METHODS: hD PSCs were isolated from human dental pulp tissues of extracted wisdom teeth and established in stem cell growth medium. h DPSCs at passage 3-5 were seeded on four commercially available scaffold biomaterials, SureO ss(Allograft), Cerabone(Xenograft), PLLA(Synthetic), and OSTEON Ⅱ Collagen(Composite), for 7 and 14 d in osteogenic medium. Cell adhesion and morphology to the scaffolds were evaluated by scanning electron microscopy(SEM). Cell proliferation and differentiation into osteogenic lineage were evaluated using DNA counting and alkaline phosphatase(ALP) activity assay, respectively. RESULTS: All scaffold biomaterials except Sure Oss(Allograft) supported h DPSC adhesion, proliferation and differentiation. hD PSCs seeded on PLLA(Synthetic) scaffold showed the highest cell proliferation and attachment as indicated with both SEM and DNA counting assay. Evaluating the osteogenic differentiation capability of hD PSCs on different scaffold biomaterials with ALP activity assay showed high level of ALP activity on cells cultured on PLLA(Synthetic) and OSTEON ⅡCollagen(Composite) scaffolds. SEM micrographs also showed that in the presence of Cerabone(Xenograft) and OSTEON Ⅱ Collagen(Composite) scaffolds, the h DPSCs demonstrated the fibroblastic phenotype with several cytoplasmic extension, while the cells on PLLA scaffold showed the osteoblastic-like morphology, round-like shape. CONCLUSION: PLLA scaffold supports adhesion, proliferation and osteogenic differentiation of hD PSCs. Hence, it may be useful in combination with hD PSCs for cell-based reconstructive therapy.

关键词： Human dental pulp stem cell Stem cell Tissue engin

Estimation of diameter and surface area flux of bubbles based on operational gas dispersion parameters by using regression and ANFIS

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International Journal of Mining Science and Technology 2013年第3期23卷 343-348页

作者： B.Shahbazi B.rezai S.Chehreh Chelgani S.M.Javad Koleini M.Noaparast Tarbiat Modares University Amirkabir University of Technology Young Researchers and Elites club Science and Research Branch Islamic Azad University Department of Mining Engineering University of Tehran

Adaptive neuro fuzzy inference system (ANFIS) procedure and regression methods were used to predict the Sauter mean bubble (bubble diameter) and surface area flux of the bubble in a flotation process. The operational conditions of flotation, impeller peripheral speed, superficial gas velocity, and weight percent solids were used as inputs of methods. By using the mentioned operational conditions, the non linear regression results showed that Sauter mean, and surface area flux of the bubble are predictable variables, where the coefficients of determination (R 2 ) are 0.57 and 0.74, respectively. To increase the accuracy of prediction an ANFIS model with cluster radius of 0.4 was applied. ANFIS model was capable of estimating both Sauter mean, and surface area flux of the bubble, where in a testing stage, satisfactory correlations, R 2 = 0.78, and 0.86, were achieved for Sauter mean, and surface area flux of bubble, respectively. Results show that the proposed ANFIS model can accurately estimate outputs and be used in order to predict the parameters without having to conduct the new experiments in a laboratory.

关键词： Bubble diameter Bubble surface area flux Flotation Regression ANFIS

塔利班上台后中国-阿富汗贸易关系研究 ——基于SWOT分析

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塔利班上台后中国-阿富汗贸易关系研究 ——基于SWOT分析

作者： Murtaza rezai 江西财经大学

学位级别：硕士