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Tunable sharp and highly selective microwave-photonic band-pass filters based on stimulated Brillouin scattering

Photonics Research 2014年第4期2卷 18-25页

作者： Yonatan Stern Kun Zhong Thomas Schneider Ru Zhang yossef ben-ezra Moshe Tur Avi Zadok Faculty of Engineering Bar-Ilan UniversityRamat-Gan 5290002Israel Beijing University of Post and Telecommunications Beijing 100876China Institut für Hochfrequenztechnik Hochschule für TelekommunikationD-04277 LeipzigGermany Faculty of Engineering Holon Institute of Technology52 Golomb St.Holon 5810201Israel School of Electrical Engineering Faculty of EngineeringTel-Aviv UniversityTel-Aviv 6997801Israel

Stimulated Brillouin scattering(SBS)in optical fibers has long been used in frequency-selective optical signal processing,including in the realization of microwave-photonic(MWP)*** this work,we report a significant enhancement in the selectivity of SBS-based MWP *** having a single passband of 250 MHz–1 GHz bandwidth are demonstrated,with selectivity of up to 44 *** selectivity of the filters is better than that of the corresponding previous arrangements by about 15 *** shape factor of the filters,defined as the ratio between their−20 dB bandwidth and their−3 dB bandwidth,is between 1.35 and *** central transmission frequency,bandwidth,and spectral shape of the passband are all independently *** enhancement is based on two advances,compared with previous demonstrations of tunable SBS-basedMWPfilters:(a)the polarization attributes of SBS in standard,weakly birefringent fibers are used to discriminate between in-band and out-of-band components and(b)a sharp and uniform power spectral density of the SBS pump waves is synthesized through external modulation of an optical carrier by broadband,frequency-swept *** signal-to-noise ratio of filtered radio-frequency waveforms and the linear dynamic range of the filters are estimated analytically and quantified ***,a figure of merit for the performance of the filters is proposed and *** filters are applicable to radio-over-fiber transmission systems.

关键词： filters scattering polarization

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Mechanisms for electric field induced color change in coupled colloidal quantum dot molecules revealed by low temperatures single particle spectroscopy

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Nano Research 2024年第12期17卷 10346-10354页

作者： yossef E.Panfil Adar Levi Somnath Koley Einav Scharf Yonatan Ossia Uri Banin Institute of Chemistry and the center for nanoscience and nanotechnology The Hebrew University of JerusalemJerusalem 91904Israel Quantum Engineering Laboratory the Department of Electrical&Systems EngineeringUniversity of PennsylvaniaPhiladelphiaPA 19104-6314USA Institute of Physics BhubaneswarOdisha-751005India

Colloidal quantum dots(QDs),the building blocks of modern displays and optoelectronic devices,have reached the highest level of size and shape control,and stability during the last 30 ***,full utilization of their potential requires integration or assembly of more than one nanocrystal as in the case of coupled quantum dots molecules(CQDM),where two core–shell QDs are fused to form two emission centers in close *** CQDMs were recently shown to switch color under an applied electric field at room *** we use cryogenic single particle spectroscopy of single CQDMs under an electric field to show that various mechanisms can contribute to the spectrum change under an applied electric field at cryogenic *** first mechanism is the control of the delocalized electron wave function when the electric field is applied along the dimer *** electric field bends the conduction band and forces the electron wave function to localize in one of the QDs yielding preferential emission of that particular *** addition,we found that QDs and CQDMs could become sensitive to surface traps under an electric *** the case of CQDMs,that can result in decreasing the intensity of one of the QDs while increasing the other QD’s ***,we show that there are surface charges which screen the applied electric field in some of the *** as well can result in electric field-induced color-tuning of *** the underlying mechanisms responsible for spectral shifts under applied electric fields is critical for the development of color-tunable devices utilizing CQDMs,including efficient displays and single photon sources.

关键词： colloidal quantum dots(QDs) quantum dot molecule nanocrystals single particle spectroscopy electric field

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Role of cannabinoids and the endocannabinoid system in modulation of diabetic cardiomyopathy

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World Journal of Diabetes 2022年第5期13卷 387-407页

作者： Mona F El-Azab Ahmed E Wakiel yossef K Nafea Mahmoud E Youssef Department of Pharmacology and Toxicology Faculty of PharmacySuez Canal UniversityIsmailia 41522Egypt Program of Biochemistry McMaster UniversityHamilton L8S 4L8OntarioCanada Department of Pharmacology and Biochemistry Delta University for Science and TechnologyMansoura 35511New CairoEgypt

Diabetic complications,chiefly seen in long-term situations,are persistently deleterious to a large extent,requiring multi-factorial risk reduction strategies beyond glycemic *** cardiomyopathy is one of the most common deleterious diabetic complications,being the leading cause of mortality among diabetic *** mechanisms of diabetic cardiomyopathy are multi-factorial,involving increased oxidative stress,accumulation of advanced glycation end products(AGEs),activation of various pro-inflammatory and cell death signaling pathways,and changes in the composition of extracellular matrix with enhanced cardiac *** novel lipid signaling system,the endocannabinoid system,has been implicated in the pathogenesis of diabetes and its complications through its two main receptors:Cannabinoid receptor type 1 and cannabinoid receptor type 2,alongside other ***,the role of the endocannabinoid system in diabetic cardiomyopathy has not been fully *** review aims to elucidate the possible mechanisms through which cannabinoids and the endocannabinoid system could interact with the pathogenesis and the development of diabetic *** mechanisms include oxidative/nitrative stress,inflammation,accumulation of AGEs,cardiac remodeling,and autophagy.A better understanding of the role of cannabinoids and the endocannabinoid system in diabetic cardiomyopathy may provide novel strategies to manipulate such a serious diabetic complication.

关键词： Δ9-tetrahydrocannabinol Autophagy Cannabinoid receptors Diabetic cardiomyopathy Endocannabinoid system Inflammation

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Effect of Calcium and Phosphorus on Nonhaeme Iron Absorption and Haematogenic Characteristics in Rats

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Food and Nutrition Sciences 2010年第1期1卷 13-18页

作者： Heba Ezz El-Din yossef 不详

The objectives of this study were to use the dry thyme leaves as source of nonhaeme iron and evaluate the effects of calcium, phosphorus and calcium + phosphorus on nonhaeme iron absorption and haematogenic characteristics in rats. Thirty adult male albino rats, weighing 150 ± 5 g were divided into five groups. The first group fed basal diet, the second group fed thyme diet, the third group fed thyme diet + calcium, the fourth group fed thyme diet + phosphorus and the fifth group fed thyme diet + calcium + phosphorus. All groups fed experimental diets for six weeks. Hemoglobin (Hb), haematocrit (Ht), red blood cell (RBC), mean corpuscular volume (MCV), serum iron (SI), serum ferritin (SF), total iron–binding capacity and transferrin saturation were determined at the beginning and the at end of the experiment. Iron in diet, Fe intake, Fe feces and Fe absorption were also evaluated. The results indicated that the lowest Fe absorption was observed in rats fed the thyme diet + calcium and thyme diet + calcium + phosphorus. Supplementation the thyme diet with calcium or calcium + phosphorus decreased the values of Hb, Ht, RBC, SI and SF. However, supplementation the thyme diet with phosphorus did not affect in Ht, RBC and MCV but Hb, SI and SF increased. The results suggest that supplementation the diet with calcium or calcium + phosphorus interfere with iron absorption.

关键词： Nonhaeme Iron Thyme Iron Absorption Hemoglobin

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Comparison of Few-layer Graphene Prepared from Natural Graphite through Fast Synthesis Approach

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Journal of Materials Science & Technology 2015年第9期31卷 907-912页

作者： Iresha R.M.Kottegoda Xuanwen Gao Liyanage D.C.Nayanajith Chinthan H.Manorathne Jun Wang Jia-Zhao Wang Hua-Kun Liu yossef Gofer Materials Technology Section of Industrial Technology Institute Institute for Superconducting and Electronic Materials University of Wollongong Department of Chemistry Bar Ilan University

We report the synthesis of high quality few-layer graphene on a large scale using high purity natural graphite from Sri Lanka. A novel thermal method was adapted to prepare graphene from intermediate graphite oxide, which was obtained by heating the intermediate at low temperature （above 150 ℃） in air for 5 min and subsequent heating at 500℃ in Argon for 15 min. The samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spec- troscopy etc. The properties and the performance of graphene were observed to depend on the graphite source. The reduced graphite oxide from Kahatagaha graphite source exhibits higher Brunauer-Emmett- Teller specific surface area -500 m^2 g^-1 and stable specific capacity as an anode in Li-ion batteries, whereas Bogala graphite showed higher initial irreversibility and higher capacity as anode, exceeding the theo- retical specific capacity of graphite. Both graphenes showed high electrical conductivity. The graphene, which exists in stacks of only a few layers, supposed to be 2-6 layers, would be promising for a vast variety of applications.

关键词： GraphiteGraphite oxideGrapheneLi-ion batteries

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Technology of Geoelectrics for Searching of Groundwater

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地学前缘 2009年第S1期16卷 3-3页

作者： Mahmoed Ibrahim yossef Airport Road Marsa Matrouh

If you drill a hole into the ground,in most places its bottom fills with water after a few *** water appears even if no rain falls and no streams flow *** water that seeps into the hole is part of the vast reservoir of subterranean ground water that saturates the Earth’s crust in a zone between a few meters and a few kilometers below the surface. Ground water is exploited by digging wells and pumping the water to the *** provides drinking water for more than half of the population of North America and is a major source of water for

关键词： groundwater in Eygpt sustainable development other sources of development ground water

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Positional effect of mutations in 5'UTR of hepatitis C virus 4a on patients' response to therapy

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World Journal of Gastroenterology 2009年第12期15卷 1480-1486页

作者： Mostafa K El Awady Hassan M Azzazy Ahmed M Fahmy Sherif M Shawky Noha G Badreldin Samar S yossef Moataza H Omran Abdel Rahman N Zekri Said A Goueli Department of Biomedical Technology National Research CenterDokkiCairo 12622Egypt Department of Chemistry and Yousef Jameel Science and Technology Research Center the American University in CairoCairo 11511Egypt Structural biology department Free University of AmsterdamDe Boelelaan 10851081 HV AmsterdamThe Netherlands National Cancer Institute Cairo 11796Egypt Department of Pathology and Laboratory Medicine University of WisconsinMadisonWI 53711United States

AIM： To investigate the effects of mutations in domain Ⅲ of the hepatitis C virus （HCV） internal ribosome entry sequences （IRES） on the response of chronic HCV genotype 4a patients to interferon therapy.METHODS： HCV RNA was extracted from 19 chronic HCV 4a patients receiving interferon/ribavirin therapy who showed dramatic differences in their response to combination therapy after initial viral clearance. IRES domain Ⅲ was cloned and 15 clones for each patient were sequenced. The obtained sequences were aligned with genotype 4a prototype using the ClustaIW program and mutations scored. Prediction of stem-loop secondary structure and thermodynamic stability of the major quasispecies in each patient was performed using the MFOLD 3.2 program with Turner energies and selected constraints on base pairing.RESULTS： Analysis of RNA secondary structure revealed that insertions in domain Ⅲ altered WatsonCrick base pairing of stems and reduced molecular stability of RNA, which may ultimately reduce binding affinity to ribosomal proteins. Insertion mutations in domain - were statistically more prevalent in sustained viral response patients （SVR, n = 14） as compared to breakthrough （BT, n = 5） patients.CONCLUSION： The influence of mutations within domain Ⅲ on the response of HCV patients to combination therapy depends primarily on the position, but not the frequency, of these mutations within IRES domain Ⅲ.

关键词： Hepatitis C virus Internal ribosome entrysequences Domain Ⅲ Genotype 4a Ribosomal sub-unit Interferon therapy RNA folding

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髋关节异响：陶瓷-陶瓷全髋关节置换的一种现象

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中华骨科杂志 2010年第3期30卷 I0007-I0011页

作者： Christopher A. Jarrett, MD Amar S. Ranawat, MD Matteo Bruzzone, MD yossef C. Blum, MD Jose A. Rodriguez, MD Chitranjan S. Ranawat, MD 朱跃良(译) 徐永清(译) Investigation performed at Lenox Hill Hospital New York NY 成都军区昆明总医院全军骨科中心 650032

背景：现代陶瓷一陶瓷全髋置换术的早期临床应用报告显示其具有优异的临床和影像学结果。只有极少数病例由于早期设计缺陷而出现了灾难性的失败，多表现为假体断裂。有几篇文献报道涉及了术后可以闻及的“嘎吱”声。本文旨在研究陶瓷一... 详细信息

背景：现代陶瓷一陶瓷全髋置换术的早期临床应用报告显示其具有优异的临床和影像学结果。只有极少数病例由于早期设计缺陷而出现了灾难性的失败，多表现为假体断裂。有几篇文献报道涉及了术后可以闻及的“嘎吱”声。本文旨在研究陶瓷一陶瓷全髋关节置换术后“嘎吱”作响的髋关节（以下简称“嘎吱”髋，译者注）的发生率。方法：2003年3月至2005年5月，3位医生对143例患者（159髋）行陶瓷一陶瓷全髋关节置换。149髋（131例）随访1年以上。以改良的HSS评分及患者主控调查问卷进行前瞻性评估。以60髋（48例）金属一聚乙烯全髋关节置换作为对照组，在年龄、性别、体重指数与陶瓷一陶瓷组病例匹配的基础上，对比“嘎吱”声或其他声音的发生率，并按事前确定的标准进行影像学评估。

关键词：全髋关节置换术后陶瓷临床应用体重指数影像学结果全髋置换术前瞻性评估 HSS评分

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