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Control of electron beam current,charge,and energy spread using density downramp injection in laser wakefield accelerators

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Matter and Radiation at Extremes 2023年第2期8卷 14-24页

作者： Céline S.Hue Yang Wan eitan Y.Levine Victor Malka Department of Physics of Complex Systems Weizmann Institute of ScienceRehovotIsrael

Density downramp injection has been demonstrated to be an elegant and efficient approach for generating high-quality electron beams in laser wakefield *** studies have demonstrated the possibilities of generating electron beams with charges ranging from tens to hundreds of picocoulombs while maintaining good beam ***,the plasma and laser parameters in these studies have been limited to specific ranges or attention has been focused on separate physical processes such as beam loading,which affects the uniformity of the accelerating field and thus the energy spread of the trapped electrons,the repulsive force from the rear spike of the bubble,which reduces the transverse momentum P⊥of the trapped electrons and results in small beam emittance,and the laser evolution when traveling in the *** this work,we present a comprehensive numerical study of downramp injection in the laser wakefield,and we demonstrate that the current profile of the injected electron beam is directly correlated with the density transition parameters,which further affects the beam charge and energy *** fine-tuning the plasma density parameters,electron beams with high charge(up to several hundreds of picocoulombs)and low energy spread(around 1%FWHM)can be *** these results are supported by large-scale quasi-threedimensional particle-in-cell *** anticipate that the electron beams with tunable beam properties generated using this approach will be suitable for a wide range of applications.

关键词： tuning beam injection

Biosafety and biosecurity in the era of biotechnology:The Middle East region

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Journal of Biosafety and Biosecurity 2022年第2期4卷 130-145页

作者： Laith AL-eitan Malek Alnemri Department of Biotechnology and Genetic Engineering Jordan University of Science and TechnologyIrbid 22110Jordan

Biotechnology became a paradigm-shifting science among all subfields of *** benefits of biotechnology have reached many practical fields,whether human health,animal,and/or ***,wherever there is a biotechnology practice,there is an associated biohazard with it,and its negative impact may reach all living entities including ***,the cooperation of the leading institutions in this field has culminated in creating the concepts and applications of biosafety and *** countries of the Middle East are considered biotechnology-practicing and have shown a clear acceptance to this *** unfortunately,the Middle East region is one that is facing the most multichallenges,which would constitute real and noticeable concern at the local and international *** challenges represented by wars and armed conflicts,deteriorating economic conditions,the large number of refugees,and the spread of many ***,limiting the region’s ability to deal with the surrounding biological hazards and struggling the way to the one health ***,this article aims to shed light on the activities of the Middle East countries in the field of biotechnology and to address potential biological threats,whether natural such as the spread of viruses,or intentional such as biological attacks and *** article also shows the capacity of the countries of the region in the field of biosafety and biosecurity based on available ***,some countries are lacking the required level of preparedness to face potential biological ***-institutional and international cooperation between the concerned countries will significantly enhance the capacity of the region in biosafety and biosecurity to meet the level of biological *** methodology:wide range of related keywords(based on the section)combined with the name of the region,or one country individually have been searched using available search engines a

关键词： Biosafety Biosecurity Biotechnology Bioterrorism Biological weapons Middle east Viruses

A New Technique for Attention Management and Somatosensory Processing in Hypnotherapy: Mental Access/Somatosensory Access (MASSA)

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Open Journal of Medical Psychology 2023年第4期12卷 192-230页

作者： eitan G. Abramowitz Hypno-Campus Institute of Medical Hypnosis and Hypno-Analysis Modiin Israel

The author introduces a new hypnotherapeutic technique termed “Mental Access/Somatosensory Access” (MASSA). MASSA is designed to utilize an external somatosensory stimulus in the context of hypnotherapy, based on a Bottom-Up/Top-Down Paradigm, which complements and mutually reinforces hypnotic inductions by using imbedded suggestions. The intervention’s algorithm includes a combination of real-time stimulation through one of the following somatosensory modalities: sensorimotor activation of the palms, visual, auditory, vibration, thermal, olfaction or oropharyngeal. These modalities are accompanied by guided hypnotic dissociation and suggestions. Somatosensory stimulation amplifies patients’ engagement in the procedure, focusing their attention on a stimulus and on the hypnotic experience during the intervention. A stream of closed questions with imbedded suggestions, presented by the therapist, is designed using suggestive presuppositions, termed by the author “The Create and Verify Principle” (CVP). This principle facilitates effective pacing and helps transform patients’ sensory and mental experiences. Imbedded suggestions followed by real-time stimulation, maintain a focus on the somatosensory content, boost the hypnotic experience, and gradually combine awareness of the somatosensory stimulation experience (Bottom-Up regulation) with memory, imagination, emotions and meanings, for mental access of resources and adaptive coping (Top-Down regulation). In the first part of this article, the author briefly introduces the neurophysiological mechanism behind the suggestive, somatosensory, attention-management intervention and provides an example of a basic algorithm of the MASSA technique. The second part includes clinical samples with scripts of successfully treated patients, who experienced tension headache, psychogenic balance disorder, tinnitus. .

关键词： Attention Somatosensory Stimulation Imbedded Suggestions Create and Verify Principle Mental Access/Somatosensory Access (MASSA) Hypnosis

Constraint Preserving Schemes Using Potential-Based Fluxes *** Transport Equations

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Communications in Computational Physics 2011年第3期9卷 688-710页

作者： Siddhartha Mishra eitan Tadmor Centre of Mathematics for Applications(CMA) University of OsloP.O.Box 1053BlindernN-0316 OsloNorway Center of Scientific Computation and Mathematical Modeling(CSCAMM) and Department of Mathematicsand Institute for Physical Sciences and Technology(IPST)University of MarylandMD 20742-4015USA

We consider constraint preserving multidimensional evolution equations.A prototypical example is provided by the magnetic induction equation of plasma *** constraint of interest is the divergence of the magnetic *** design finite volume schemes which approximate these equations in a stable manner and preserve a discrete version of the *** schemes are based on reformulating standard edge centered finite volume fluxes in terms of vertex centered *** potential-based approach provides a general framework for faithful discretizations of constraint transport and we apply it to both divergence preserving as well as curl preserving *** present benchmark numerical tests which confirm that our potential-based schemes achieve high resolution,while being constraint preserving.

关键词： Multidimensional evolution equations magnetohydrodynamics finite-difference finite volume schemes constraint transport potential-based schemes

Geometric Counting on Wavefront Real Spherical Spaces

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Acta Mathematica Sinica,English Series 2018年第3期34卷 488-531页

作者： Bernhard KROTZ eitan SAYAG Henrik SCHLICHTKRULL Universitat Paderborn Institut Jur MathematikWarburger Strafle 10033098 PaderbornDeutschland Department of Mathematics Ben Gurion University of the NegevP.O.B.653Be'er Sheva 84105Israel Department of Mathematics University of CopenhagenUniversitetsparken 5DK-2100 Copenhagen ODenmark

We provide L^p-versus L~∞-bounds for eigenfunctions on a real spherical space Z of wavefront type. It is shown that these bounds imply a non-trivial error term estimate for lattice counting on Z. The paper also serve... 详细信息

关键词： Homogeneous spaces real spherical spaces lattice counting error term wavefront lemma spectral analysis norm comparison of eigenfunctions

Surveillance tools for detection of recurrent nasopharyngeal carcinoma: An evidence-based review and recommendations

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World Journal of Otorhinolaryngology-Head and Neck Surgery 2022年第3期8卷 187-204页

作者： Andrew Thamboo Kim H.Tran Annette X.Ye Issraa Shoucair Basel Jabarin eitan Prisman Cathie Garnis St.Paul's Sinus Centre Otolaryngology Head and Neck Surgery1081Burrard StVancouverV6Z 1Y6BCCanada Department of Biomedical Physiology and Kinesiology SimonFraserUniversity8888 University DrBurnabyV5A1S6BCCanada The University of British Columbia Faculty of Medicine MDProgram317-2194Health SciencesMallVancouverV6T1Z3BCCanada British Columbia Cancer Research Centre Cancer Genetics and Developmental Biology675 W 10th AveVancouverV5Z 1L3BCCanada VancouverGeneral Hospital Otolaryngology HeadandNeckSurgery899W12thAveVancouverV5Z 1M9BCCanada

Objective: Nasopharyngeal carcinomas (NPC) are tumors arising from epithelium of the nasopharynx. The 5-year survival rate of primary NPC is 80% with significant risks of recurrence. The objective here is to provide an evidence-based systemic review of the diagnostic value of different modalities in detecting local, regional, and distal recurrent NPC, as well as the associated costs with these ***: MEDLINE, EMBASE, and the Cochrane review database were queried. Two hundred and twenty-three abstracts were generated using the inclusion criteria: patients >18 years of age;histopathological reference standard;and modalities pertaining to imaging or ***: Twenty-four manuscripts fulfilled the inclusion criteria and 5 surveillance tools identified: endoscopy, MR, FDG-PET, Tc-99m MIBI and201TI SPECT, and EBV ***: For local surveillance, endoscopy is the gold standard recommendation, with increased efficacy if Narrow Band Imaging or contact endoscopy are utilized. MRI and FDG-PET is also recommended to help with local to distal spread;however, Tc-99m MIBI and201TI SPECT are options as well. EBV DNA is recommended as a cheap and accessible adjunct surveillance tool if an available as an option.

关键词： EBV DNA FDG-PET Imaging MR Endoscopy Recurrent Nasopharyngeal Carcinoma

Differentiation of murine male germ cells to spermatozoa n a soft agar culture system

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Asian Journal of Andrology 2012年第2期14卷 285-293页

作者： Mahmoud Abu Elhija eitan Lunenfeld Stefan Schlatt Mahmoud Huleihel The Shraga Segal Department of Microbiology and Immunology Faculty of Health Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Department of Obstetrics and Gynecology Soroka University Medical Center and Faculty of Health Sciences Ben-Gurion University of the Negev Beer-Sheva 84105 Israel Centre of Reproductive Medicine and Andrology of the University of Menster Menster 84149 Germany

Establishment of an in vitro system that allows the development of testicular germ cells to sperm will be valuable for studies of spermatogenesis and future treatments for male infertility. In the present study, we developed in vitro culture conditions using three-dimensional agar culture system （SACS）, which has the capacity to induce testicular germ cells to reach the final stages of spermatogenesis, including spermatozoa generation. Seminiferous tubules from testes of 7-day-old mice were enzymatically dissociated, and intratubular cells were cultured in the upper layer of the SACS in RPMI medium supplemented with fetal calf serum （FCS）. The lower layer of the SACS contained only RPMI medium supplemented with FCS. Colonies in the upper layer were isolated after 14 and 28 days of culture and were classified according to their size. Immunofluorescence and real-time PCR were used to analyse specific markers expressed in undifferentiated and differentiated spermatogonia （Vasa, Dazl, OCT-4, C-Kit, GFR- a-l, CD9 and a-6-integrin）, meiotic cells （LDH, Crem-1 and Boule） and post-meiotic cells （Protamine-1, Acrosin and SP-IO）. Our results reveal that it is possible to induce mouse testicular pre-meiotic germ cell expansion and induce their differentiation to spermatozoa in SACS. The spermatozoa showed normal morphology and contained acrosomes. Thus, our results demonstrate that SACS could be used as a novel in vitro system for the maturation of pre-meiotic mouse germ cells to post-meiotic stages and morphologically-normal spermatozoa.

关键词： acrosome agar in vitro culture meiosis spermatogenesis spermatogonia spermatozoa testis

Regulation of spermatogenesis by paracrine/autocrine testicular factors

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Asian Journal of Andrology 2004年第3期6卷 259-268页

作者： Mahmoud Huleihel eitan Lunenfeld Department of Microbiology and Immunology and BGU Cancer Research Center Faculty of Health Sciences Ben-Gurion University of the NegevBeer-ShevaIsraelDepartment of Obstetrics and GynecologySoroka University Medical Center Faculty of Health SciencesBen-Gurion University of the NegevBeer-ShevaIsrael

Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-γ, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus, the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility.

关键词： spermatogenesis paracrine autocrine cytokine growth factor

Non-Oscillatory Hierarchical Reconstruction for Central and Finite Volume Schemes

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Communications in Computational Physics 2007年第5期2卷 933-963页

作者： Yingjie Liu Chi-Wang Shu eitan Tadmor Mengping Zhang School of Mathematics Georgia Institute of TechnologyAtlantaGA 30332-0160USA. Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA Department of Mathematics Institute for Physical Science and Technologyand Center of Scientific Computation and Mathematical Modeling(CSCAMM)University of MarylandCollege ParkMD 20742USA Department of Mathematics University of Science and Technology of ChinaHefeiAnhui 230026China

This is the continuation of the paper”Central discontinuous Galerkin methods on overlapping cells with a non-oscillatory hierarchical reconstruction”by the same *** hierarchical reconstruction introduced therein is applied to central schemes on overlapping cells and to finite volume schemes on non-staggered *** takes a new finite volume approach for approximating non-smooth solutions.A critical step for high-order finite volume schemes is to reconstruct a non-oscillatory high degree polynomial approximation in each cell out of nearby cell *** the paper this procedure is accomplished in two steps:first to reconstruct a high degree polynomial in each cell by using e.g.,a central reconstruction,which is easy to do despite the fact that the reconstructed polynomial could be oscillatory;then to apply the hierarchical reconstruction to remove the spurious oscillations while maintaining the high *** numerical computations for systems of conservation laws are performed without characteristic *** particular,we demonstrate that this new approach can generate essentially non-oscillatory solutions even for 5th-order schemes without characteristic decomposition.

关键词： Central scheme discontinuous Galerkin method ENO scheme finite volume scheme MUSCL scheme TVD scheme.