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Endophytic bacteria associated with endangered plant Ferula sinkiangensis K. M. Shen in an arid land： diversity and plant growth-promoting traits

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Journal of Arid Land 2017年第3期9卷 432-445页

作者： LIU Yonghong GUO Jianwei LI Li Mipeshwaree D ASEM ZHANG Yongguang osama A mohamad Nimaichand SALAM LI Wenjun Key Laboratory of Biogeography and Bioresource in Arid Land Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China University of Chinese Academy of Sciences Beijing 100049 China Key Laboratory of Crops with High Quality and Efficient Cultivation and Security Control Yunnan Higher Education Institutions Honghe University Mengzi 661100 China State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources School of Life Sciences Sun Yat-Sen University Guangzhou 510275 China Environmental Science Department Institute for Post Graduate of Environment Study Arish University Arish 45511 Egypt

Ferula spp. are traditional medicinal plants found in arid land. Large-scale excavation for extracting bioactive compounds from the plants in arid regions of Xinjiang over the last few years has, however, significandy decreased their distributions. Due to the urgent need for preservation of these plant resources, along with the need of searching for alternative source of the useful metabolites, it is important to screen the endophytic microbial resources associated with the plant Ferula sinkiangensis K. M. Shen. In the study, a total of 125 endophytic bacteria belonging to 3 phyla, 13 orders, 23 families, and 29 genera were isolated based on 16S rRNA gene sequencing data. Among the different isolates, three strains isolated from roots were potential novel species of the genera Porphyrobacter, Paracoccus and draycofatopsis. In this study, 79.4% and 57.1% of the total isolates were capable of producing indole-3-acetic acid （IAA） and siderophore, respectively. And, 40.6% of the strains inhibit the growth of fungal pathogen Afternaria alternata, 17.2% and 20.2% strains were positive for antagonism against Vertidllium dahlia 991 and V. dahlia 7, respectively. These results demonstrated that E sinkiangensis is a rich reservoir of endophytic bacterial resources with potential for production of biologically important functions such as plant growth-promoting factors.

关键词： endophytic bacteria Ferula sinkiangensis endangered species growth promoting

Diversity of cultivable endophytic bacteria associated with halophytes in Xinjiang of China and their plant beneficial traits

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Journal of Arid Land 2021年第8期13卷 790-800页

作者： LI Li GAO Lei LIU Yonghong FANG Baozhu HUANG Yin osama a a mohamad Dilfuza EGAMBERDIEVA LI Wenjun MA Jinbiao State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Faculty of Biology National University of UzbekistanTashkent 100174Uzbekistan State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-Sen UniversityGuangzhou 510275China

Endophytic bacteria from halophytes have a wide range of application prospects in various fields,such as plant growth-promoting,biocontrol activity and stress *** current study aimed to identify cultivable endophytic bacteria associated with halophytes grown in the salt-affected soil in Xinjiang Uygur Autonomous Region,China and to evaluate their plant beneficial traits and enzyme-producing *** bacteria were isolated from Reaumuria soongorica(PalL Maxim.),Artemisia carvifolia(Buch.-*** ***.),Peganum harmala *** Suaeda dendroides(***.)by using the cultural-dependent *** we classified these bacteria based on the difference between their sequences of 16S rRNA(16S ribosomal RNA)*** showed that the isolated bacteria from *** belonged to the genera Brucella,Bacillus and *** bacteria from *** belonged to the genera Micromonospora and *** bacteria from *** belonged to the genera Paramesorhizobium,Bacillus and *** bacteria from *** belonged to the genus ***,the genus Bacillus was detected in the three above plants,indicating that Bacillus is a common taxon of endophytic bacteria in ***,our results found that about 37.50%of the tested strains showed strong protease-producing activity,6.25%of the tested strains showed strong cellulase-producing activity and 12.50%of the tested strains showed moderate lipase-producing ***,all isolated strains were positive for IAA(3-Indoleacetic acid)production,31.25%of isolated strains exhibited a moderate phosphate solubilization activity and 50.00%of isolated strains exhibited a weak siderophore production *** findings suggest that halophytes are valuable resources for identifying microbes with the ability to increase host plant growth and health in salt-affected soils.

关键词： endophytes environmental microbiology halophytes biodiversity plant beneficial properties

Cardiac autonomic function in patients with myasthenia gravis:analysis of the heart-rate variability in the time-domain

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Neuroimmunology and Neuroinflammation 2015年第1期2卷 21-25页

作者： Sherifa Ahmed Hamed Khaled osama mohamad mohamad Adam Department of Neurology and Psychiatry Assiut University Hospital71516 AssiutEgypt Department of Cardiology Assiut University Hospital71516 AssiutEgypt

Aim:Myasthenia gravis(MG)is a neuromuscular transmission disorder caused by acetylcholine receptor *** autonomic dysfunctions were rarely reported in patients with *** cardiac abnormalities were variable and reported in patients at severe stages of the disease and with *** investigated cardiac functions in patients with MG using Ambulatory 24‑h electrocardiographic Holter‑***:This study included 20 patients with MG with a mean age of 28.45±8.89 years and duration of illness of 3.52±1.15 *** standard Holter reports include data for heart‑rate,ventricular ectopies(VEs),supraventricular ectopies(SVEs),heart-rate variability(HRV),ST,QT,atrial fibrillation and T‑wave ***:VEs,SVEs and ST‑T changes were reported in 55%,40%and 20%of patients *** with healthy subjects(n=20),HRV components including SDNN,SDANN,SDNN Index,RMS‑SD and pNN50(P=0.001 for all)were reduced in patients indicating sympathetic and parasympathetic autonomic *** abnormalities were reported in 30-60%of *** significant correlations were identified between SDNN,RMS‑SD,pNN50,and duration of ***:Depressed HRV may be an early manifestation of autonomic neuropathy in patients with MG even in milder stages of the *** information is useful in rating disease progression and the efficacy of therapeutic interventions.

关键词： Cardiac autonomic function heart-rate variability myasthenia gravis

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新疆药用植物牛至内生细菌多样性与抗菌活性

微生物学通报 2021年第4期48卷 1140-1150页

作者：高磊刘永红马金彪 osama Abdalla Abdelshafy mohamad 李文均李丽中国科学院新疆生态与地理研究所荒漠与绿洲生态国家重点实验室新疆乌鲁木齐830011 中山大学生命科学学院有害生物控制与资源利用国家重点实验室广东省热带亚热带植物资源实验室广东广州510275 中国科学院大学北京100049

【背景】植物内生菌作为微生物群落中一类非常重要的组成部分,在多个领域都有广泛的应用价值,如促进植物生长、抵抗病虫害、生物固氮、降解有毒有害化合物等。【目的】进一步丰富新疆野果林苹果腐烂病害的生防资源以及分析牛至内生细菌... 详细信息

【背景】植物内生菌作为微生物群落中一类非常重要的组成部分,在多个领域都有广泛的应用价值,如促进植物生长、抵抗病虫害、生物固氮、降解有毒有害化合物等。【目的】进一步丰富新疆野果林苹果腐烂病害的生防资源以及分析牛至内生细菌多样性特征。【方法】通过纯培养方法,对健康植物牛至组织进行内生细菌的分离纯化,并进行16S rRNA基因序列分析;再利用平板对峙法筛选具有抑制苹果腐烂病病原菌生长的内生细菌。【结果】共分离到168株内生细菌,最终确定为4门5纲8目12科17属,其中优势属为芽胞杆菌属(Bacillus)。由分离实验结果可知,M1号TSA培养基,M5号组氨酸-棉子糖培养基和M6号NA培养基是分离牛至内生细菌较为理想的培养基;采自新源县野果林的牛至内生细菌多样性较为丰富,在牛至根部内生细菌种类更多;通过拮抗实验共筛选出59株牛至内生细菌具有较好的抑菌效果。【结论】新疆药用植物牛至内生细菌的物种多样性较为丰富,而且富含一批有效抑制野苹果腐烂病病原菌生长的内生细菌菌株。因此,本研究在新疆野果林苹果腐烂病的生物防治和药用植物内生细菌种质资源的填补等方面具有重要意义。

关键词：新疆牛至内生细菌多样性苹果腐烂病拮抗作用

新疆古尔班通古特沙漠链霉菌:从可培养资源多样性到抗菌天然产物的生物合成潜力探索

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中国科学：生命科学 2024年第9期54卷 1699-1718页

作者：李帅董雷韩嘉瑞史国源连文慧刘永红李博翰 osama Abdalla Abdelshafy mohamad 李文均中山大学生命科学学院广州510275 中国科学院新疆生态与地理研究所乌鲁木齐830011 华南农业大学生命科学学院广州510642

全球抗生素耐药性和新型抗菌药物短缺问题日益严峻,因此迫切需要发现新的或更有效的抗生素.沙漠生境蕴藏着丰富的链霉菌资源,是新型活性天然产物的重要潜在来源,但其在很大程度上仍未得到充分探索.本研究旨在深入挖掘新疆古尔班通古特... 详细信息

全球抗生素耐药性和新型抗菌药物短缺问题日益严峻,因此迫切需要发现新的或更有效的抗生素.沙漠生境蕴藏着丰富的链霉菌资源,是新型活性天然产物的重要潜在来源,但其在很大程度上仍未得到充分探索.本研究旨在深入挖掘新疆古尔班通古特沙漠中的可培养链霉菌资源,并探究其抗菌天然产物生物合成潜力.本文利用8种培养基对4份沙漠样品中的链霉菌进行分离、纯化和鉴定,随后对代表性链霉菌进行培养特征观察、次级代谢产物生物合成基因簇(biosynthetic gene cluster,BGC)预测和抗菌活性评价.研究结果显示,共分离得到469株链霉菌,占放线菌总菌株数的44.0%.从64株代表性链霉菌基因组中共预测得到1937个BGCs,分属于1068个基因簇家族(gene cluster family,GCF),其中97.5%的GCFs表现出较高的新颖性和次级代谢功能谱系多样性.此外,通过抗菌活性筛选,发现41株代表性链霉菌对至少一种临床病原菌具有拮抗作用,且其中2株具有广谱抗菌活性.这些发现表明,新疆古尔班通古特沙漠中蕴藏着极为丰富多样的可培养链霉菌资源,且绝大多数具有巨大的次级代谢产物生物合成潜力和较好的抗菌活性,为新型抗生素药物先导化合物的开发提供了重要依据和优良菌种来源.

关键词：沙漠链霉菌可培养天然产物生物合成抗菌活性

Novel self assembly behavior for γ-alumina nanoparticles

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Particuology 2012年第6期10卷 744-750页

作者： osama Saber Physics Dept Faculty of ScienceKing Faisal UniversityAl-Hassa 31982P.O.Box 400Saudi Arabia Egyptian Petroleum Research Institute Nasr CityP.O.Box 11727CairoEgypt

In this study, self assembly behavior was induced for γ-alumina nanoparticles by adsorption of dimethyl disulfide. Following this trend, we have developed a chemical process to obtain ＇y-alumina in the nano scale. Scanning electron microscopy images of the prepared γ-alumina showed big and strong agglomeration of the nanoparticles indicating that these nanoparticles have strong surface forces. Transmission electron microscopy images confirmed that the γ-alumina nanoparticles 3-7 nm in size were converted to uniform spherical shape in the size range of 1-2 mm after shaking with dimethyl disulfide in the presence of n-hexane at room temperature. This phenomenon did not appear in the case of alumina in the micro scale. The surface properties of the prepared γ-alumina in the nano scale were characterized and compared with the γ-alumina in the micro scale by using low temperature nitrogen adsorption-desorption system, indicating that the specific surface area of the prepared γ-alumina nanoparticles is larger than that of the γ-alumina in the micro scale. Furthermore, micro- and meso-pores were observed for the if-alumina nanoparticles while only mesoporous structure was detected for the γ-alumina in the micro scale. These experimental results suggested that the self assembly behavior of the γ-alumina nanoparticles may be due to the selective adsorption ofdimethyl disulfide in the micropores of these nanoparticles to act as bridge linking the nanoparticles.

关键词： γ-Alumina nanoparticlesNovel self assembly behaviorScanning and transmission electronmicroscopy

Improvement of sintering,nonlinear electrical,and dielectric properties of ZnO-based varistors doped with TiO2

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Chinese Physics B 2016年第6期25卷 575-580页

作者： osama A Desouky K E Rady Bilbis Higher Institute of Engineering (BHIE) Bilbis Sharqia Egypt Engineering Basic Sciences Department Faculty of engineering Menoufia University Shebin EI-Kom Egypt

The effects of TiO2 on sintering and nonlinear electrical properties of（98.5-x）ZnO–0.5MnO2–0.5Co2O3-0.5Bi2O3–xTiO2（x = 0.3,0.5,0.7,0.9 mol%） ceramic varistors prepared by the ceramic technique are investigated in this *** optimum sintering temperature of the prepared samples is deduced by determining the firing shrinkage and water absorption *** optimum sintering temperature is found to be 1200℃,at which each of the samples shows a maximum firing shrinkage and minimum water *** minimum water absorption appears in a sample of x = 0.9 mol%.Higher sintering temperature and longer sintering time give rise to a reduction in bulk density due to the increased amount of porosity between the large grains of ZnO resulting from the rapid grain growth induced by the liquid phase *** crystal size of ZnO decreases with increasing TiO2 *** addition of TiO2 improves the nonlinear coefficient and attains its maximum value at x = 0.7 mol% of TiO2,further addition negatively affects it.A decrease in capacitance consequently in the dielectric constant is recorded with increasing the frequency in a range of 30 kHz–200 *** temperature and composition dependences of the dielectric constant and AC conductivity are also *** increase of temperature raises the dielectric constant because it increases ionic response to the field at any particular frequency.

关键词： ZnO varistors water absorption nonlinear electrical properties dielectric constant

Analysis of moose-vehicle collisions countermeasures in northern climates

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Transportation Safety and Environment 2021年第3期3卷 280-290页

作者： osama Abaza Colleen CMoran Department of Civil Engineering University of Alaska Anchorage3211 Providence DriveEIB 301LAnchorageAK 99508USA University of Alaska Anchorage 3211 Providence DriveEIB 301LAnchorageAK 99508USA

This research investigates the reliability of two measures intended to reduce moose-vehicle collisions(MVCs):continuous lighting and clearing/grubbing of roadway *** analyses and a combined regression analysis were conducted to measure the effects of several combinations of variables on MVC rates,including clearing and grubbing,continuous lighting,clearing without grubbing,moose population,precipitation,snowfall,and maximum snow *** corridor improvement projects were analyzed based on the variables *** previous studies,it has been hypothesized that MVC rates are influenced by environmental conditions such as snowfall and *** Alaska Department of Transportation and Public Facilities(DOT&PF)has performed many studies on MVCs along several *** corridors showed a significant drop in the number of MVCs after the installation of continuous *** results show there is a consistent drop in MVCs after clearing and grubbing,with the exception of one *** combined clearing/grubbing and continuous lighting projects also resulted in a consistent drop in *** projects with clearing and grubbing as a component had varying trends in MVCs,which may indicate that DOT&PF Maintenance and Operations performed clearing of re-vegetated areas,or that older growth is less of an attractant for moose.

关键词： continuous lighting clearing grubbing moose-vehicle collisions countermeasures cold regions wildlife

Resistance to acid degradation,sorptivity,and setting time of geopolymer mortars

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Frontiers of Structural and Civil Engineering 2022年第6期16卷 781-791页

作者： osama A MOHAMED Rania AL-KHATTAB Waddah AL-HAWAT College of Engineering Abu Dhabi UniversityAbu DhabiUnited Arab Emirates

Experimental evaluations were conducted to determine the water sorptivity,setting time,and resistance to a highly acidic environment,of mortar with alkali-activated ground granulated blast furnace slag(GBS)binder and also of combinations of fly ash and GBS *** were activated using mixtures of NaOH and Na_(2)SiO_(3)*** molarity of NaOH in the mixtures ranged from 10 mol·L^(−1)to 16 mol·L^(−1),and the Na_(2)SiO_(3)/NaOH ratio was varied from 1.5 to *** samples were produced using three binder combinations:1)GBS as the only binder;2)blended binder with a slag-to-fly ash ratio of 3:1;and 3)mixed binder with 1:1 ratio of slag to fly *** samples were mixed and cured at(22±2)°C till the day of the *** impact of activator solution alkalinity,activator ratio Na_(2)SiO_(3)/NaOH,GBS content on the rate of water absorption were *** 7,28,and 90 d of immersion in a 10%sulfuric acid solution,the resistance of a geopolymer matrix to degradation was assessed by measuring the change in sample *** influence of solution alkalinity and relative fly ash content on setting times was ***-activated mortar with a slag-to-fly ash ratio of 3:1 had the least sorptivity compared to the two other binder combinations,at each curing age,and for mortars made with each of the NaOH alkaline activator *** sorptivity decreased with age and sodium hydroxide concentrations,suggesting the production of geopolymerization *** reduction in weight of sample occurred after immersion in the strong acid H_(2)SO_(4)solution for three months,regardless of binder *** was due to the synthesis of hydration and geopolymerization products in the presence of curing water,which outweighed the degradation of the geopolymer matrix caused by sulfuric acid.

关键词： alkali-activated materials fly ash sorptivity durability of concrete sodium hydroxide sodium silicates reduction in CO_(2)emissions sulfuric acid