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Asian Pacific Journal of Tropical Medicine 2014年第7期7卷 517-520页

作者： Hossein Hamidinejat Mohammad Hossein Razi Jalali ramezan Ali jafari Kiomars Nourmohammadi Department of Pathobiology Veterinary FacultyShahid Chamran University Department of Clinical Sciences Veterinary FacultyShahid Chamran University MSc Student of Parasitology Shahid Chamran University

Objective:To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province,***:A total of 1 000 fecal and 1 000 trachea samples were collected from *** from both fecal and tracheal samples were stained with modified ZiehlNeelsen method and nested PCR-RFTP according to amplification of 18S rRNA gene using Ssp1 and Vsp 1 restriction enzymes and DNA ***:From the examined chickens0.7%was positive for Cryptosporidium,Infection was present in 0.3%fecal samples and also in0.5%*** 0.3%of simultaneous infections in fecal and tracheal samples were *** PCR of our isolates demonstrated Cryptosporidium ***:In our work,low rate of Cryptosporidium baileyi infection was detected,but in critical situations and our poor management circumstances,cryptosporidiosis occurs in serious feature especially in immune suppressed individuals.

关键词： Cryptosporidium Prevalence PCR-RFLP Sequencing Chicken Iran

Convalescent plasma therapy in a pregnant COVID-19 patient with a dramatic clinical and imaging response: A case report

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World Journal of Radiology 2020年第7期12卷 137-141页

作者： ramezan jafari Nematollah Jonaidi-jafari Fatemeh Dehghanpoor Amin Saburi Radiology Department Faculty of Medicine and Chemical Injuries Research CenterBaqiyatallah University of Medical SciencesTehran 18151777Iran Health Research Center and Faculty of Medicine Baqiyatallah University of Medical SciencesTehran 18151777Iran Radiology Department Faculty of MedicineBaqiyatallah University of Medical SciencesTehran 18151777Iran Chemical Injuries Research Center and Faculty of Medicine Baqiyatallah University of Medical SciencesTehran 18151777Iran

BACKGROUND Coronavirus disease 2019(COVID-19)is a novel very contagious infection which was designated a pandemic in all countries of the world in April *** presentation varies from mild to severe infection,but the majority of infected patients have mild *** therapeutic choices have been suggested to treat the infection,but none are fully *** SUMMARY Herein we present a 26-year-old woman with a twin pregnancy at 36 wk and one day gestation with confirmed COVID-19 who responded dramatically to convalescent plasma therapy(CPT)and *** Although this case report shows the efficacy of CPT in addition to usual medications used for COVID-19,there are many questions that need to be answered regarding dosage,para-clinical efficacy,side effects and combination therapy.

关键词： Case report Convalescent plasma therapy Pregnancy COVID-19 Favipiravir Radiologic findings

“Pulmonary target sign” as a diagnostic feature in chest computed tomography of COVID-19

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World Journal of Radiology 2021年第7期13卷 233-242页

作者： ramezan jafari Nematollah Jonaidi-jafari Houshyar Maghsoudi Fatemeh Dehghanpoor U Joseph Schoepf Kyle A Ulversoy Amin Saburi Department of Radiology Faculty of MedicineBaqiyatallah University of Medical SciencesTehran 11151877Iran Health Research Center Baqiyatallah University of Medical SciencesTehran 11151877Iran Department of Radiology and Radiological Science Medical University of South CarolinaCharlestonSC 29425United States Faculty of Medicine Augusta University/University of Georgia Medical PartnershipAthensGA 30606United States Chemical Injuries Research Center Systems Biology and Poisonings InstituteBaqiyatallah University of Medical SciencesTehran 11151877Iran

BACKGROUND In chest computed tomography(CT)scan,bilateral peripheral multifocal groundglass opacities,linear opacities,reversed halo sign,and crazy-paving pattern are suggestive for coronavirus disease 2019(COVID-19)in clinically suspicious cases,but they are not specific for the diagnosis,as other viral pneumonias,like influenza and some viral pneumonia may show similar imaging *** To find a specific imaging feature of the disease would be a welcome guide in diagnosis and management of challenging *** Chest CT imaging findings of 650 patients admitted to a university Hospital in Tehran,Iran between January 2020 and July 2020 with confirmed COVID-19 infection by RT-PCR were reviewed by two expert *** addition to common non-specific imaging findings of COVID-19 pneumonia,radiologic characteristics of“pulmonary target sign”(PTS)were *** is defined as a circular appearance of non-involved pulmonary parenchyma,which encompass a central hyperdense dot surrounded by ground-glass or alveolar *** PTS were presented in 32 cases(frequency 4.9%).The location of the lesions in 31 of the 32 cases(96.8%)was peripheral,while 4 of the 31 cases had lesions both peripherally and *** 25 cases,the lesions were located near the pleural surface and considered pleural based and half of the lesions(at least one lesion)were in the lower segments and lobes of the lungs.22 cases had multiple lesions with a>68%*** than 87%of cases had an adjacent bronchovascular ***-glass opacities were detectable adjacent or close to the lesions in 30 cases(93%)and only in 7 cases(21%)was consolidation adjacent to the *** Although it is not frequent in COVID-19,familiarity with this feature may help radiologists and physicians distinguish the disease from other viral and noninfectious pneumonias in challenging cases.

关键词： Chest computed tomography Diagnosis Viral pneumonia COVID-19 Pulmonary target sign Case report

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.jafari-TALOOKOLAEI H.GHANDVAR E.JUMAEV S.KHATIR T.CUONG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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Non-harmonic resonance of viscoelastic structures subjected to time-dependent exponentially decreasing transverse distributed loads

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Earthquake Engineering and Engineering Vibration 2023年第3期22卷 825-840页

作者： Nasrin jafari Department of Civil Engineering Isfahan University of TechnologyIsfahan 84156-83111Iran

In this paper,the non-harmonic resonance of Bernoulli viscoelastic beams,Kirchhoff viscoelastic plates,Timoshenko viscoelastic beams,and Mindlin viscoelastic plates subjected to time-dependent exponentially decreasing transverse distributed load is investigated for the first *** constitutive equations are expressed utilizing Boltzmann integral law with a constant bulk *** displacement vector is approximated by employing the separation of variables *** Laplace transformation is used to transfer equations from the time domain to the Laplace domain and vice *** novel point of the proposed method is to express,prove and calculate the critical time in which the displacement will be several times the displacement at time *** addition,this new method calculates the maximum deflection at the critical time,explicitly and exactly,without any need to follow the time-displacement curve with a low computational ***,the proposed method introduces the critical range of time so that the responses are greater than the responses at time zero.

关键词： Bernoulli and Timoshenko viscoelastic beams critical time non-harmonic resonance time-dependent decreasing exponential load Kirchhoff and Mindlin viscoelastic plates

Corrosion Behaviors of Two Types of Commercial Stainless Steel after Plastic Deformation

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Journal of Materials Science & Technology 2010年第9期26卷 833-838页

作者： Esmaeil jafari Materials Science and Engineering Department Islamic Azad University Shiraz Branch

The influence of deformation temperature,strain rate and alloying elements such as chromium,nickel,copper,on corrosion resistance of a 304 stainless steel after plastic deformation was *** techniques employed were tensile test at room and elevated temperature,deep drawing tests at various strain rates,X-ray diffraction test and potentiodynamic and cyclic polarization,metallography by optical and scanning electron *** showed that chromium,nickel and copper had a significant effect on corrosion resistance of steel after plastic *** was observed that corrosion resistance after plastic deformation was a function of deformation temperature and alloying elements.

关键词： Corrosion resistance Plastic deformation Stainless steel Phase transformation Polarization test

Cross-focusing of two chirped Gaussian laser beams and THz wave generation in plasmas of multi-ion species under a weakly relativistic and ponderomotive regime

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Plasma Science and Technology 2022年第10期24卷 1-11页

作者： M R jafari MILANI S REZAEI M J jafari Photonics and Quantum Technologies Research School Nuclear Science and Technology Research InstituteTehran 14665-678Iran Plasma and Fusion Research School Nuclear Science and Technology Research InstituteTehran 14399-51113Iran

The generation of terahertz(THz)waves via the beating of two high-intensity chirped Gaussian lasers in a multi-ion-species plasma is numerically studied by taking into account the weak relativistic and ponderomotive regime of *** coupled differential equations for beamwidth parameters are extracted by introducing the dielectric function of such plasma and using WKB and paraxial ray *** amplitude of THz radiation at beat frequency resulting from the nonlinear current density induced by the beat ponderomotive force of the cross-focusing of beams was *** impacts of the chirp frequency parameter,initial laser intensity and initial ionic species density(specifically,the presence of singly and doubly charged ions)in the plasma on THz generation were *** numerical results reveal that THz radiation generation strongly depends on the chirp frequency parameter.A specific range of chirp frequencies exists for self-focusing as well as THz generation with a'turning point',where the THz emission reaches its maximum *** results show that the strength of self-focusing and consequently the generated THz radiation are reduced by increasing the density of doubly charged ionic species in the plasma due to the suppression of the nonlinear effects.

关键词： laser–plasma interaction THz generation chirped Gaussian laser beams

Introducing the general condition for an operator in curved space to be unitary

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Chinese Physics B 2021年第8期30卷 220-223页

作者： jafari Matehkolaee Mehdi Faculty of Physics Semnan UniversitySemnan35131-19111Iran

We investigate the general condition for an operator to be *** condition is introduced according to the definition of the position operator in curved *** a particular case,we discuss the concept of translation operator in curved space followed by its relation with an anti-Hermitian *** we introduce a universal formula for adjoint of an arbitrary linear *** procedure in this paper is totally different from others,as we explore a general approach based only on the algebra of the *** approach is only discussed for the translation operators in one-dimensional space and not for general operators.

关键词： operator theory algebraic methods unitary operator translation operator

Data driven models for compressive strength prediction of concrete at high temperatures

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Frontiers of Structural and Civil Engineering 2020年第2期14卷 311-321页

作者： Mahmood AKBARI Vahid jafari DELIGANI Department of Civil Engineering Faculty of EngineeringUniversity of KashanKashan ***Iran

The use of data driven models has been shown to be useful for simulating complex engineering processes,when the only information available consists of the data of the *** this study,four data-driven models,namely multiple linear regression,artificial neural network,adaptive neural fuzzy inference system,and K nearest neighbor models based on collection of 207 laboratory tests,are investigated for compressive strength prediction of concrete at high *** addition for each model,two different sets of input variables are examined:a complete set and a parsimonious set of involved *** results obtained are compared with each other and also to the equations of NIST Technical Note standard and demonstrate the suitability of using the data driven models to predict the compressive strength at high *** addition,the results show employing the parsimonious set of input variables is sufficient for the data driven models to make satisfactory results.

关键词： data driven model compressive strength oncrete high temperature

Investigation of parameters influencing erosive wear using DEM

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Friction 2020年第1期8卷 136-150页

作者： Akbar jafari Reza ABBASI HATTANI Department of Mechanical Engineering Sirjan University of TechnologySirjan ***Iran

The effects of several parameters on the erosive wear were studied using the discrete element method(DEM).The Finnie model was implemented using an open‐source *** the time integration,the Gear algorithm was used,and to ensure the accuracy of the DEM results,a time‐step sensitivity analysis was *** problem was modeled in two parts:first,the impact of a single particle on a surface was modeled,and then a more general model was prepared to examine the wear of surfaces under the flow of *** effects of the surface area,impact angle,speed,particle size,particle density,Young’s modulus,Poisson’s ratio,and restitution coefficient on the wear were studied numerically,and the results are discussed herein.

关键词： wear erosion Finnie discrete element