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Anisotropic optical and electronic properties of two- dimensional layered germanium sulfide

Nano Research 2017年第2期10卷 546-555页

作者： Dezhi Tan Hong en Lim Feijiu Wang Nur Baizura mohamed Shinichiro Mouri Wenjin Zhang yuhei Miyauchi Mari Ohfuchi Kazunari Matsuda Institute of Advanced energy Kyoto University Uji Kyoto 611-001 I Japan Fujitsu Laboratories Ltd. Atsugi 243-0197 Japan

Two-dimensional （2D） layered materials, transition-metal dichalcogenides, and black phosphorus have attracted considerable interest from the viewpoints of fundamental physics and device applications. The establishment of new functionalities in anisotropic layered 2D materials is a challenging but rewarding frontier, owing to the remarkable optical properties of these materials and their prospects for new devices. Herein, we report the anisotropic and thickness- dependent optical properties of a 2D layered monochalcogenide of germanium sulfide （GeS）. Three Raman-scattering peaks corresponding to the B3g,, A1g, and A2g modes with a strong polarization dependence are demonstrated in the GeS flakes, which validates polarized Raman spectroscopy as an effective method for identifying the crystal orientation of anisotropic layered GeS. Photoluminescence （PL） is observed with a peak at -1.66 eV that originates from the direct optical transition in GeS at room temperature. The polarization-dependent characteristics of the PL, which are revealed for the first time, along with the demonstration of anisotropic absorption, indicate an obvious anisotropic optical transition near the band edge of GeS, which is supported by density functional theory calculations. The significantly thickness-dependent PL is observed and discussed. This anisotropic layered GeS presents opportunities for the discovery of new physical phenomena and will find applications that exploit its anisotropic properties, such as polarization-sensitive photodetectors.

关键词： germanium sulfide anisotropic optical property 2D layered materials photoluminescence polarized optical spectroscopy

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Occult HCV Infection (OCI) Diagnosis in Cirrhotic and Non-cirrhotic Naive Patients by Intra-PBMC Nested Viral RNA PCR

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Journal of Clinical and Translational Hepatology 2017年第4期5卷 319-326页

作者： mohamed Darwish Ahmed Abd Alla Saleh Ahmed elibiary George y.Wu Mostafa Kamel el-Awady Tropical Medicine Department Faculty of MedicineAl-Azhar UniversityCairoEgypt Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA Department of Microbial Biotechnology National Research CenterCairoEgypt

Background and Aims:Occult HCV infections(OCIs)include IgG antibody seronegative cryptogenic(COCIs),as well as seropositive secondary na(i)ve(SNOCIs)and experienced(SEOCIs)*** used peripheral-blood-mononuclear-cell(PBMC)-PCR to evaluate COCIs and SNOCIs prevalence,serum HCV spontaneous disappearance(SCSD)in na(i)ve cirrhotics and non-cirrhotics,intra-PBMC HCV-RNA strands in relation to cirrhosis density in na(i)ve non-viremia cases,and HCV-RNA seroconversion after 1 year of solitary naive intra-PBMC ***:The anti-HCV IgG antibodypositive na(i)ve-patients(n=785)were classified into viremic(n=673)and non-viremic[n=112,including non-cirrhotics(n=55)and cirrhotics(n=57)],and 62 controls without evidence of *** and post-HCV non-viremia cases(n=62+112=174)were submitted to hepatic Fibroscanelastography *** subjects(n=847)were screened for intra-PBMC HCV-RNA sense and antisense strands by ***:Na(i)ve-OCI cases(4.84%)that were diagnosed by PBMC-PCR significantly raised the total numbers of HCV-infection to 714(p=0.01).The percent positivity of SNOCIs(34.82%)was significantly higher than for asymptomatic-COCIs(3.125%,p=0.0001).Comparing PBMC-PCR with single-step-reverse-transcription(SRT)-PCR for identification of SCSD in na(i)ve IgG antibody-positive nonviremia patients(n=112)revealed a decline in SCSD prevalence by PBMC-PCR(from 14.27%to 9.3%),regardless of presence of hepatic cirrhosis(p=0.03).SCSD was found to be higher by PBMC-PCR in non-cirrhotics compared to cirrhotics(p=0.0001),with an insignificant difference when using SRT-PCR(p=0.45).Intra-PBMC HCV-RNA infection was significantly more frequent in cirrhotics compared to both non-cirrhotics and controls(pensity was recognized in intra-PBMC HCV-RNA infection with sense(p=0.0001)or antisense strand(p=0.003).HCV-RNA seroconversion was associated with intra-PBMC infection when both sense and antisense strands were dete

关键词： OCIs PBMCs Na(i)ve Cirrhosis

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Analysis of 3D localization in underwater optical wireless networks with uncertain anchor positions

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Science China(Information Sciences) 2020年第10期63卷 174-181页

作者： Nasir SAEED Abdulkadir CelIK mohamed-Slim ALOUINI Tareq y.AL-NAFFOURI Computer ElectricalMathematical Sciences & Engineering (CEMSE) DivisionKing Abdullah University of Science and Technology (KAUST)

Localization accuracy is of paramount importance for the proper operation of underwater optical wireless sensor networks(UOWSNs). However, underwater localization is prone to hostile environmental impediments such as drifts owing to the surface and deep currents. These cause uncertainty in the deployed anchor node positions and pose daunting challenges to achieve accurate location estimations. Therefore, this paper analyzes the performance of three-dimensional(3D) localization for UOWSNs and derives a closedform expression for the Cramer Rao lower bound(CRLB) by using time of arrival(ToA) and angle of arrival(AoA) measurements under the presence of uncertainty in anchor node positions. Numerical results validate the analytical findings by comparing the localization accuracy in scenarios with and without anchor nodes position uncertainty. Results are also compared with the linear least square(LLS) method and weighted LLS(WLLS) method.

关键词： underwater optical wireless sensor networks localization three-dimensional uncertainty

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An approach to evaluate the efficien.y of γ-ray detectors to determine the radioactivity in environmental samples

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Chinese Physics C 2014年第6期38卷 60-66页

作者： mohamed.S.Badawi Ahmed.M.el-Khatib Samah.M.Diab Sherif.S.Nafee Ekram.A.el-Mallah Physics Department Faculty of Science Alexandria University 21511 Alexandria Egypt

This work provides an approach to determine the efficien.y of T-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficien.y transfer formula （ET）, the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficien.y. The experimental calibration process was done using radioactive （Cylindrical ＆ Marinelli） sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the （NaI ＆ HPGe） detectors using volumetric radioactive sources.

关键词： y-ray detector efficien.y efficien.y transfer effective solid angles radioactive source

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Versatile synthesis of cadalene and iso-cadalene from himachalene mixtures:Evidence and application of unprecedented rearrangements

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Chinese Chemical Letters 2020年第7期31卷 1851-1854页

作者： Mustapha Ait el Had Abdelouahd Oukhrib mohamed Zaki Martine Urrutigoity Ahmed Benharref Remi Chauvin Laboratoire de Chimie Biomoleculaire Substances Naturelies et Reactivite(URAC 16)Faculte des Sciences SemlaliaUniversite Cadi AyyadB.P.2390MarrakechMorocco CNRS LCC(Laboratoire de Chimie de Coordination)BP 4409931077Toulouse Cedex 4France INP-enSIACET 4 allee Emile Monso31030Toulouse CedexFrance Universite de Toulouse UPSICT-FR 259931062Toulouse Cedex 9France

From a mixture of α-,β-and y-himachalenes extracted from waste wood of Atlas cedar(Cedrus atlantica),cadalene(1,6-dimethyl-4-isopropylnaphthalene)and iso-cadalene(1,6-dimethyl-3-isopropylnaphthalene)were produced in two steps with up to 71%±5%yield through the ar-himachalene intermediate using I2 and/or AlCl3 as *** selectivity is shown to sharply depend on the operating conditions:while I2/AlCl3 in dichloromethane promotes the formation of cadalene,the formation of iso-cadalene is favored in the presence of AlCl3 in *** bicyclic aromatic compounds were thus obtained through unique rearrangements involving sequential C—C bond cleavage/fo rmation and hydride transfer *** the absence of AlCl3 or I2,dihydrocurcumene was also found to be formed with up to 70%selectivity.A tentative mechanism is proposed and discussed.

关键词： Aromatic reactivity Cadalenes Dihydrocurcumene Himachalenes Rearrangements

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Synthesis and comparative study of reactivities of δ-lactone,estor group and oxazinone ring in coumarin derivatives towards carbon or nitrogen nucleophiles

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Chinese Journal of Chemistry 1990年第5期8卷 469-473页

作者： el-KAFRAWy,A.F. SOLIMAN,A.y. BAKER,H.M. mohamed,F.K. el-KADy,M.y.Department of Chemistry,Faculty of Science,Ain Shams University and Faculty of Education at el-Fayoum,Cairo.Egypt Department of Chemistry Faculty of Science Ain Shams University and Faculty of Education at El‐Fayoum Cairo Egypt

Condensation of methyl 7-methylcoumarin-4-acetate(2)with primary amines and with an- thranilic acid gave 7-methyl-2-oxo-N-aryl-2H-[1]-benzopyran-4--acetamide(4a—d)and(7),respectively. Compound 7 underwent cyclization to give 2-(7-methyl-2-oxo-2H-[1]-benzopyran-4-yl)-methyl-4H-3,1- benzoxazin-4-one(3).The reaction of 3 with aromatic amines gave the corresponding quinazolone derivatives 5 which tautomerises to the thermodynamically more stable isomer 6,whereas its reaction with Grignard reagents and aromatic aldehydes gave 8a,8b,and 9a,9b,respectively.

关键词： Synthesis and comparative study of reactivities of lactone,estor group and oxazinone ring in coumarin derivatives towards carbon or nitrogen nucleophiles ring

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Late Diagnosis of Turner Syndrome in Adulthood;a Case Study from the endocrinology-Diabetology Nutrition Department of the National Hospital of Pikine Senegal

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Open Journal of endocrine and Metabolic Diseases 2024年第5期14卷 115-122页

作者： Nafy Ndiaye yakham mohamed Leye Ngone Diaba Diack Mamadou Ba Bibatou Abdoulaye Leye Abdou Aziz Diouf Alassane Diouf Jean Pascal Demba Diop Internal Medicine/endocrinology-Diabetology Department Teaching Hospital of Pikine Cheikh Anta Diop University Dakar Senegal Department of Gynaecology-Obstetric Teaching Hospital of Pikine Cheikh Anta Diop University Dakar Senegal Department of Human Genetic Faculty of Medicine Pharmacy and Odontology Cheikh Anta Diop University Dakar Senegal

Introduction: Turner syndrome is a rare genetic disorder characterised by the presence of one X chromosome and the absence of part or all of an X or y chromosome and patients may experience delayed puberty and infertility. Our study aimed to evaluate the diagnostic delay in our practice and analyze the impact of this diagnostic delay on the effectiveness of patient management. Patients and Methods: Turner syndrome patients were identified from the endocrinology-diabetology nutrition department Database We examined the records of patients in whom the karyotype analysis favoured Turner syndrome. Results: We have selected 5 patients’ records of female patients with Turner syndrome. The mean age was 25, ranging from 19 to 29 years. Primary amenorrhea and characteristic dysmorphic features were observed in all patients. One married patient, who sought consultation for infertility, expressed a desire for pregnancy. Short stature was identified in 3 patients. Primary hypothyroidism and hypertension were respectively found in 1 and 2 patients. Gonadal dysgenesis was noted in 100% of cases. Karyotype analysis revealed monosomy X in 2 patients and mosaic patterns in others. All patients received estrogen-progestin treatment. Antihypertensive therapy was initiated for 2 patients. One patient is on L-thyroxine. In the short term, treatment led to the onset of menstruation after the initial months. Evaluation of treatment efficacy on internal genital organs is yet to be performed. Due to uncertain benefits at this age, growth hormone therapy was not considered for our patients. We provided counseling on assisted reproductive options for couples desiring to conceive. In our study, all patients were placed on estrogen-progestin therapy, and the response appeared favorable. Conclusion: In our practice, the diagnosis of Turner syndrome occurs very late in adulthood, at an age when growth hormone treatment is nearly ineffective. Treatment typically revolves around estrogen-progestin

关键词： Turner Syndrome Primary Amenorrhea Adult Pikine

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Numerical Study of Temperature and electric Field Effects on the Total Optical Absorption Coefficient in the Presence of Optical Inter-Conduction-Subband Transitions in InGaN/GaN Single Parabolic Quantum Wells

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Fluid Dynamics & Materials Processing 2022年第5期18卷 1253-1261页

作者： Redouane en-nadir Haddou el-ghazi Anouar Jorio Izeddine Zorkani Hassan Abboudi Fath Allah Jabouti LPS Sidi Mohamed Ben Abdullah UniversityFez30000Morocco enSAM Hassan-II UniversityCasablanca20470Morocco

In this paper,we theoretically investigate the total optical coefficient(TOAC)considering 1S-2P and 2S-2P conduction subband transitions in a single parabolic quantum well(SPQW)with an on-center hydrogen-like *** the framework of the effective-mass approximation,the Schrödinger equation is solved numerically to obtain the eigenvalues and their corresponding eigenvectors using the finite difference *** calculations are performed for finite confinement potential height,taking into account the dielectric and effective mass mismatches between GaN and InGaN materials under the considered electric field and temperature *** temperature dependence of the effective mass,dielectric constant and band gap energy are obtained *** the one hand,the results show that a significant shift is produced with the variation of both the temperature and the intensity of the electric *** the other hand,the absorption spectrum is shifted to lower energies with increasing both electric field strength and ***,its amplitude is enhanced with an increase in the intensity of the electric field,and show a slight drop with increasing temperature for the two optical transitions *** results show that such parameters can be used to adjust the optical properties of single parabolic Quantum Well for solar cell applications.

关键词： TOAC optical transitions SPQW electric field intensity temperature hydrogenic-impurity

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Improving corrosive wear resistance of Mg-Zn-y-Zr alloys through heat treatment

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镁合金学报(英文) 2023年第6期11卷 1981-1995页

作者： S.D.Wang M.y.Wu D.K.Xu en-hou Han Northwestern Polytechnical University Xi’an 710072China Key Laboratory of Nuclear Materials and Safety Assessment Chinese Academy of SciencesInstitute of Metal ResearchShenyang 110016China Department of Chemical and Materials engineering University of AlbertaEdmonton T6G 2G6Canada

The wear behavior of an as-received Mg-Zn-y-Zr alloy before and after a facile heat treatment was investigated under sliding in air and 0.5 wt.%NaCl *** revealed that the wear resistance of the alloy was remarkably enhanced after the heat treatment,irrespective of testing *** wear mechanism was predominantly abrasive wear accompanied by oxidation under the dry sliding condition,while corrosive wear was dominant under sliding in the NaCl *** superior corrosive wear resistance was attributed to the homogenous distribution of fine I-phase precipitates in the alloy by the heat treatment,leading to a reduction in wear,corrosion as well as wear-corrosion *** wear-accelerated corrosion rate was remarkably alleviated after the heat treatment.

关键词： Magnesium alloy Heat treatment Corrosion Wear Tribocorrosion

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HCV Therapy Follow-up Fractionation (CTF2) by Intra-PBMC Nested RNA PCR Recognizes Early Virologic Response and Relapse

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Journal of Clinical and Translational Hepatology 2018年第2期6卷 147-154页

作者： mohamed Darwish Ahmed Abd Alla Saleh Ahmed elibiary Ramy Hassan elshaboury George y.Wu Reham M.Dawood Mostafa Kamel el Awady Tropical Medicine Department Faculty of MedicineAl-Azhar UniversityCairoEgypt Department of Pharmacy Massachusetts General HospitalBostonMAUSA Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterHartfordCTUSA Department of Microbial Biotechnology National Research CenterCairoEgypt

Background and Aims:Sustained virologic response is evaluated by single-step reverse transcription(SRT)PCR as-say,which assesses hepatitis C virus(HCV)clearance from plasma but not from tissues such as peripheral blood mono-nuclear cells(PBMCs).Persistence of HCV RNA in PBMCs beyond end of treatment(EOT)is associated with *** goal was to measure intra-PBMC HCV RNA levels during oral antiviral therapy according to the HCV therapy follow-up fractionation(CTF2)***:Compen-sated chronic HCV patients(n=278 SRT-PCR positive)were scheduled to receive oral antiviral *** were followed-up by SRT and intra-PBMCs HCV RNA PCR at the end of the 2nd,6th,10th,14th,18th and 24th weeks to evaluate virus clearance from plasma and PBMCs,*** CTF2 protocol evaluated SRT and PBMC PCR status at each follow-up point for determining therapy continuation or inter-ruption to address cost ***:All patients tested negative by SRT PCR after therapy for 2 ***-cation of the CTF2 protocol revealed:a)increasing HCV clear-ance rate from 75.9%at the end of 10th week to 90.3%at the end of 24th week(pelimination rates diagnosed by PBMC HCV RNA PCR(?)compared to PBMC HCV RNA PCR(+)from the 6th to 24th week of treatment(py compared to the decline in positivity curves by PBMC PCR at the 6th-18th week compared to the 24th week(pent continuation;and e)solitary evaluation of EOT sustained HCV infection and relapses by PBMC HCV RNA(py elimination of serum and tissue(PBMC)HCV infection by oral antiviral therapy can be achieved and evaluated during a cost-effective CTF2 pro-tocol application.

关键词： CTF2 protocol HCV PBMCs PCR Cost-effectiveness

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