检索结果-南通市图书馆

Acute and chronic toxicity studies of hydromethanol leaf extract of Helianthus annuus *** rats

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2018年第9期11卷 534-539页

作者： Samuel O.Onoja Samuel c.udem Aruh O.Anaga Isaac.u.Asuzu Department of Veterinary Physiology and Pharmacology Michael Okpara University of AgricultureUmudike Department of Veterinary Physiology and Pharmacology Faculty of Veterinary MedicineUniversity of Nigeria

Objective:To investigate the safety levels of hydromethanol leaf extract of Helianthus annuus Linn.(***) in ***:Acute oral toxicity test of hydromethanol leaf extract of *** was conducted through up and down method at 2.00 g/kg dose limit in *** chronic toxicity study was conducted by administering different concentrations(0.25,0.50 and 1.00 g/kg) of hydromethanol extract of *** in feed,for 90 consecutive *** days 30,60 and 90,blood samples were collected from the retro-orbital plexus of the rats for determination of serum biochemical *** examination of the pancreas,livers,kidneys and testis were also ***:The LD_(50) of the hydromethanol extract of *** greater than 2.00 g/kg and it significantly(P uced serum *** days 60 and 90,the serum urea and creatinine levels of hydromethanol extract of *** groups were elevated when compared with the control *** were fibrosis in the kidneys and livers;degeneration and necrosis in the testis and significant dose-dependent increases in number and size of pancreatic islet of ***:The findings suggest that hydromethanol extract of *** is tolerated in short term administration,but long term(up to 90 days) administration at high doses,may elicit hepatic,testicular and nephrotic disorder.

关键词： Helianthus annuus Toxicity Histopathology Serum biochemistry

Physical,Mechanical,and Tribological Attributes of Stir-cast AZ91/Sic_p composite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 295-305页

作者： K.K.Ajith Kumar Abhilash Viswanath T.P.D.Rajan u.T.S.Pillai B.c.Pai Material Science and Technology Division CSIR-National Institute for Interdisciplinary Science and Technology

In the present investigation, composites with silicon carbide particle （Sicp） as reinforcement and AZ91 magnesium alloy as matrix have been synthesized using liquid metal stir-casting technique with optimized processing conditions. The composites with good particle distribution in the matrix, and better grain refinement and good interfacial bonding between the matrix and reinforcement have been obtained. The effect of Sicp content on the physical, mechanical, and tribological properties of Mg-based metal matrix composite （MMc） is studied with respect to particle distribution, grain refinement, and particle/matrix interfacial reactions. The electrical conductivity, coefficient of thermal expansion, microas well as macro-hardness, tensile and compressive properties, and the frac.ure behavior of the composites along with dry sliding wear of the composites have been evaluated and compared with the base alloy.

关键词： composite AZ91D alloy casting alloy Mechanical properties Wear

Synthesis and Some Properties of Metal Organic chemical Vapour Deposited Molybdenum Oxysulphide Thin Films

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2010年第6期26卷 552-557页

作者： B.Olofinjana G.O.Egharevba M.A.Eleruja c.Jeynes A.V.Adedeji O.O.Akinwunmi B.A.Taleatu c.u.Mordi E.O.B.Ajayi Department of Physics Obafemi Awolowo UniversityIle-IfeNigeria Department of chemistry Obafemi Awolowo UniversityIle-IfeNigeria Department of Electronic and Electrical Engineering University of SurreyGuildfordSurrey GU2 5XHUK Department of chemistry and Physics Elizabeth City State UniversityElizabeth CityNC 27909USA

Molybdenum oxodithiocarbamate was prepared as thin films which were deposited on sodalime glass a single solid source precursor for molybdenum oxysulphide substrates using metal organic chemical vapour deposition （MOcVD） technique at a temperature of 420~c. Rutherford backscattering spectroscopy （RBS） was used to determine the elemental composition of the film which showed that the films contained large amounts of oxygen. The large amount of oxygen was attributed to the large abundance of oxygen in the starting material. A direct optical energy gap of 3.31 eV was obtained from the analysis of the absorption spectrum. The scanning electron microscopy （SEM） micrographs of the films showed that the films were continuous and porous. An estimated average size of the grains was below 5 #m. X-ray diffraction （XRD） showed that the deposited films were crystalline in nature.

关键词： Molybdenum oxodithiocarbamate Molybdenum oxysulphide Metal organic chemical vapour deposition (MOcVD) Thin film

Short mucin 1 alleles are associated with low virulent H pylori strains infection

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第12期13卷 1885-1886页

作者： Bárbara Peleteiro Nuno Lunet Filipe Santos-Silva Leonor David c.u Figueiredo Henrique Barros Department of Hygiene and Epidemiology Medical Faculty University of Porto Portugal Institute of Molecular Pathology and Immunology of the university of Porto Portugal

TO THE EDITORWe read with interest the article published by Nguyen et al in the World Journal of Gastroenterology, showing an association between short Muc6 alleles and H pjloff infection. These results, together with previous observations by Vinall et al, reinforce the role of mucin genes （Muc6 and Muc1） VNTR polymorphisms for the variability in individual susceptibility to H pylori infection that cannot be explained by differences in environmental factors.

关键词： H pylori Muc1 Polymorphism cagA vacA

Graphene/SrTiO3 hetero interface studied by X-ray photoelectron spectroscopy

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2016年第4期26卷 422-426页

作者： S.Karamat c.Ke u.Y.Inkaya Rizwan Akram Ilker Yildiz S.Shah Zaman A.Oral Department of Physics Middle East Technical University cOMSATS Institute of Information Technology Microelectronics centre School of Electrical and Electronic Engineering Nanyang Technological University Department of Electrical Engineering College of Engineering Qassim University

The present paper focuses on study of graphene and strontium titanate（SrTiO3or STO） interface. An ambient pressure chemical vapour deposition（AP-cVD） setup is used to grow graphene on STO（110）substrates in the presence of methane, argon and hydrogen gases at 1000 °c for 4 h. Raman spectroscopy measurements confirm the presence of graphene on STO substrates due to the existence of typical D and G peaks referring to graphene. These characteristic peaks are missing in the spectrum for bare substrates.X-ray photoelectron spectroscopy（XPS） is carried out for elemental analysis of samples, and study their bonding with STO substrates. We employed the valence band spectrum to calculate the valence band offset（VBO） and conduction band offset（cBO） at the G-STO interface. Also, we present an energy band diagram for Bi-layer and ABc（arranging pattern of carbon layers） stacked graphene layers.

关键词： chemical vapour deposition X-ray photoelectron spectroscopy Raman spectroscopy Graphene Valence band maximum

Probability to retrieve testicular spermatozoa in azoospermic patients

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2000年第3期2卷 199-205页

作者： H.-J.Glanden L.-c.Horn W.Dorschner u.Paasch J.Kratzsch Department of Dermatology/Andrology unit Department of Dermatology Department of PathologyDepartment of Dermatology Department of UrologyDepartment of Dermatology/Andrology UnitDepartment of Clinical Chemistry and Pathological Biochemistry University of Leipzig D-04103 Leipzig Germany

Aim: The degree of probability to retrieve spermatozoa from testicular tissue for intracytoplasmic sperm injection intooocytes is of interest for c.unselling of infertility patients. We investigated the relation of sperm retrieval to clinical dataand histological pattern in testicular biopsies from azoospermic patients. Methods: In 264 testicular biopsies from142 azoospermic patients, the testicular tissue was shredded to separate the spermatozoa, histological semi-thin sec-tions of which were then evaluated using Johnsen score. Results: The retrieval of spermatozoa correlated signifi-cantly (P cular volume (r = 0.49), the FSH concentration ( r = -0.66), the maximum score(r = 0.85) and the mean Johnsen score (r = 0.81). In the multivariate regression analysis the successful testicularsperm extraction showed the closest relationship to the maximum score. The testicular volume correlated significantlywith the mean Johnsen score ( r = 0.64, P um FSH concentration mainly with the maxi-mum score ( r = -0.77; P cryptorchidism showed a significantly lower Johnsenscore compared to the patients who did not have any testicular disease in the past (3.7 ± 2.4 vs. 5.9 ± 2. 5; P conc.usion: In a limited range, the testicular volume and the FSH concentration in serum were related to theJohnsen score which correlated significantly with the sperm retrieval. The successful sperm retrieval can be expected inall azoospermic patients irrespective of the results of clinical examination. However, the probability of retrieval of sper-matozoa decreased significantly in patients with a FSH level > 18 u/L, tesficular volume coreum Johnsen score < 7.

关键词： sperm extraction testicular histology azoospermia male infertility follicle stimulating hormone

confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第1期17卷 21-27页

作者： Dan Ionut Gheonea Tatiana crtnǎ Tudorel c.urea carmen Popescu Anca Bǎdǎrǎu Adrian Sǎftoiu Research center of Gastroenterology and Hepatology University of Medicine and Pharmacy CraiovaCraiova 200349Romania Physiology Department University of Medicine and Pharmacy Carol Davila BucharestBucharest 050474Romania cytology Laboratory Emergency Hospital CraiovaCraiova 200642Romania

Gastrointestinal cancers represent a major c.use of morbidity and mortality,with incomplete response to chemotherapy in the advanced stages and poor *** plays a c.ucial part in tumor growth and metastasis,with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary *** laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast *** markers of angiogenesis in association with confocal laser endomicroscopic examination(immunoendoscopy),as a future challenge,will add functional analysis to the morphological aspect of the neoplastic *** review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization,resulting in a broad spectrum of potential clinical applications,and also preclinical research that c.uld be translated to human studies.

关键词： confocal laser endomicroscopy Immunoendoscopy Fluoresceine Acriflavine cancer

Synthesis of highly fluorescent carbon dots from lemon and onion juices for determination of riboflavin in multivitamin/mineral supplements

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Pharmac.utical Analysis 2019年第3期9卷 209-216页

作者： Severino S. Monte-Filho Stefani I.E. Andrade Marcelo B. Lima Mario c.u. Araujo universidade Federal da Paraíba CCEN Departamento de Química P.O. Box 5093 Zip Code 58051-970 Joao Pessoa PB Brazil universidade Federal Rural de Pernambuco-unidade Acad^emica de Serra Talhada UAST Zip Code 56909-535 Serra Talhada PE Brazil

In this work, lemon and onion biomasses commonly found in street markets are for the first time used to develop a facile, fast and low-cost one-step microwave-assisted carbonization method for synthesis of highly fluorescent carbon dots (cDs). The struc.ure and optical properties of cDs were investigated by TEM, XRD, XRF, uV-Vis, FTIR, and fluorescence spectroscopy. cDs displayed satisfactory optical pro-prieties, a high quantum yield of 23.6%, and excellent water solubility, and the particle size was 4.23-8.22 nm with an average diameter of 6.15 nm. An efficient fluorescent resonance energy transfer (FRET) between the cDs and riboflavin was achieved with cDs acting as donor and riboflavin as acceptor. A linear relationship between FRET and the riboflavin concentration from 0.10 to 3.0 μg/mL was observed, allowing the development of an ac.urate and fast analytical method to determine this vitamin in multivitamin/mineral supplements. Despite the potential interferences in these supplements, cDs were selective for riboflavin under optimized conditions. A paired t-test at a 95% confidence level indicated no statistically significant difference between the proposed and the reference methods. Recovery test presented values ranged from 96.0% to 101.4%. The limit of detection and relative standard deviation were estimated at 1.0 ng/mL and ctively. cDs were successfully synthesized in a domestic microwave oven (1450 W, 6 min), presenting satisfactory parameters when compared with results of other studies reported in the literature, suggesting that the proposed method is a potentially useful method for the synthesis of cDs and determination of riboflavin.

关键词： carbon dots Microwave-assisted carbonization Lemon-onion juice Riboflavin Multivitamin/mineral supplements Fluorescence

Forward pion-nucleon charge exchange reaction and Regge constraints

在线全文

学校读者我要写书评

暂无评论

chinese Physics c 2009年第12期33卷 1318-1322页

作者：黄飞 A. Sibirtsev S. Krewald c. Hanhart J. Haidenbauer u.-G. Meiβner Department of Physics and Astronomy University of Georgia Athens Georgia 30602 USA Helmholtz-Institut fr Strahlen-und Kernphysik und Bethe center for Theoretical Physics Universitt Bonn D-53115 Bonn Germany Excited Baryon Analysis center Thomas Jefferson National Accelerator Facility Newport News Virginia 23606 USA Institut fr Kernphysik and Jlich center for Hadron Physics Forschungszentrum Jlich D-52425 Jlich Germany Institute of Advanced Simulation Forschungszentrum Jlich D-52425 Jlich Germany

We present our recent study of pion-nucleon charge exchange amplitudes above 2 GeV. We analyze the forward pion-nucleon charge exchange reaction data in a Regge model and compare the resulting amplitudes with those from the Karlsruhe-Helsinki and George-Washington-university partial-wave analyses. We explore possible high-energy constraints for theoretical baryon resonance analyses in the energy region above 2 GeV. Our results show that for the pion-nucleon charge exchange reaction, the appropriate energy region for matching meson-nucleon dynamics to diffractive scattering should be around 3 GeV for the helicity flip amplitude.

关键词： pion-nucleon interaction Regge model