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      • KCI등재

        Mechanical and Thermal Characteristics of Optimized Electrospun Nylon 6,6 Nanofibers by Using Taguchi Method

        Saleh S. Abdelhady,Said H. Zoalfakar,M. A. Agwa,Ashraf A. Ali 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.11

        This study is an attempt to optimize the electrospinning process to produce minimum Nylon 6,6 nanofibers by using Taguchi statistical technique. Nylon 6,6 solutions were prepared in a mixture of formic acid (FA) and Dichloromethane (DCM). Design of experiment by using Taguchi statistical technique was applied to determine the most important processing parameters influence on average fiber diameter of Nylon 6,6 nanofiber produced by electrospinning process. The effects of solvent/nylon and FA/DCM ratio on average fiber diameter were investigated. Optimal electrospinning conditions were determined by using the signal-to-noise (S/N) ratio that was calculated from the electrospun Nylon 6,6 nanofibers diameters according to "the-smaller-the-better" approach. The optimum Nylon 6,6 concentration (NY%) and FA/DCM ratio were determined. The morphology of electrospun nanofibers is significantly altered by FA/DCM solvent ratio as well as Nylon 6,6 concentration. The smallest diameter and the narrowest diameter distribution of Nylon 6,6 nanofibers (166 ffi 33 nm) were obtained for 10 wt% Nylon 6,6 solution in 80 wt% FA and 20 wt% DCM. An increase of 118%, 280% and 26% in tensile strength, modulus of elasticity and elongation at break over as-cast was obtained, respectively. Glass transition temperature of Nylon 6,6 nanofibers were determined by using differential scanning calorimeter (DSC). Analysis of variance ANOVA shows that NY% is the most influential parameter.

      • KCI등재

        Purification and Characterization of Anabaena flos-aquae Phenylalanine Ammonia-Lyase as a Novel Approach for Myristicin Biotransformation

        Asmaa M. Arafa,Afaf E. Abdel-Ghany,Samih I. El-Dahmy,Sahar Abdelaziz,Yassin El-Ayouty,Ashraf S. A. El-Sayed 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.4

        Phenylalanine ammonia-lyase (PAL) catalyzes the reversible deamination of phenylalanine to cinnamic acid and ammonia. Algae have been considered as biofactories for PAL production, however, biochemical characterization of PAL and its potency for myristicin biotransformation into MMDA (3-methoxy-4, 5-methylenedioxyamphetamine) has not been studied yet. Thus, PAL from Anabaena flos-aquae and Spirulina platensis has been purified, comparatively characterized and its affinity to transform myristicin was assessed. The specific activity of purified PAL from S. platensis (73.9 μmol/mg/min) and A. flos-aquae (30.5 μmol/mg/min) was increased by about 2.9 and 2.4 folds by gel-filtration comparing to their corresponding crude enzymes. Under denaturing-PAGE, a single proteineous band with a molecular mass of 64 kDa appeared for A. flos-aquae and S. platensis PAL. The biochemical properties of the purified PAL from both algal isolates were determined comparatively. The optimum temperature of S. platensis and A. flos-aquae PAL for forward or reverse activity was reported at 30oC, while the optimum pH for PAL enzyme isolated from A. flos-aquae was 8.9 for forward and reverse activities, and S. platensis PAL had maximum activities at pH 8.9 and 8 for forward and reverse reactions, respectively. Luckily, the purified PALs have the affinity to hydroaminate the myristicin to MMDA successfully in one step. Furthermore, a successful method for synthesis of MMDA from myristicin in two steps was also established. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to track the product formation.

      • KCI등재

        Effect of solvent on the characteristics of nanostructured composites of poly (1-naphthylamine) with poly (vinyl alcohol)

        Ufana Riaz,Sharif Ahmad,S.M. Ashraf 한국물리학회 2009 Current Applied Physics Vol.9 No.3

        Efficient utilization of inherently conducting polymers in nano technological applications faces the challenge to assemble them into highly ordered structures which may yield novel properties. The present study reports for the first time the synthesis and characterization of nanostructured poly (1-naphthylamine) (PNA) dispersed polyvinyl alcohol (PVA) composites. The composites were prepared by loading PNA from 2 wt% to 10 wt% in PVA in aqueous as well as nonaqueous media. The composites were characterized by UV–visible spectroscopy, TEM, stress–strain studies, electrical conductivity measurements and moisture absorption studies under controlled humidity. A discrete but uniform distribution of nanoparticles was obtained in PNA/PVA composites synthesized in water having particle size between 5 and 30 nm. A self assembled network of nanostructured PNA particles was obtained in case of PNA/PVA composites synthesized in N-methylpyrolidone (NMP) with particle sizes between 10 and 65 nm. The variation in the nanostructured morphology of PNA particles in PVA matrix in the two cases resulted from the pronounced interaction of PVA with NMP through hydrogen bonding. This leads to the formation of a homogeneous matrix that facilitates the formation of a self assembled network of PNA nano particles. In case of PNA/PVA composites synthesized in water, lower affinity of PVA towards water was responsible for a discrete, agglomerate free distribution of PNA particles. We have found that the PNA/PVA nano composite synthesized in water exhibited good mechanical properties and electrical conductivity (8.1 × 10-1 S/cm) as well as lowest moisture absorption (4 wt%) which holds potential for use in semiconductor and biomedical devices. Efficient utilization of inherently conducting polymers in nano technological applications faces the challenge to assemble them into highly ordered structures which may yield novel properties. The present study reports for the first time the synthesis and characterization of nanostructured poly (1-naphthylamine) (PNA) dispersed polyvinyl alcohol (PVA) composites. The composites were prepared by loading PNA from 2 wt% to 10 wt% in PVA in aqueous as well as nonaqueous media. The composites were characterized by UV–visible spectroscopy, TEM, stress–strain studies, electrical conductivity measurements and moisture absorption studies under controlled humidity. A discrete but uniform distribution of nanoparticles was obtained in PNA/PVA composites synthesized in water having particle size between 5 and 30 nm. A self assembled network of nanostructured PNA particles was obtained in case of PNA/PVA composites synthesized in N-methylpyrolidone (NMP) with particle sizes between 10 and 65 nm. The variation in the nanostructured morphology of PNA particles in PVA matrix in the two cases resulted from the pronounced interaction of PVA with NMP through hydrogen bonding. This leads to the formation of a homogeneous matrix that facilitates the formation of a self assembled network of PNA nano particles. In case of PNA/PVA composites synthesized in water, lower affinity of PVA towards water was responsible for a discrete, agglomerate free distribution of PNA particles. We have found that the PNA/PVA nano composite synthesized in water exhibited good mechanical properties and electrical conductivity (8.1 × 10-1 S/cm) as well as lowest moisture absorption (4 wt%) which holds potential for use in semiconductor and biomedical devices.

      • SCISCIESCOPUS

        Near-side azimuthal and pseudorapidity correlations using neutral strange baryons and mesons ind+Au, Cu + Cu, and Au + Au collisions at<sub>sNN</sub>=200GeV

        Abelev, B.,Adamczyk, L.,Adkins, J. K.,Agakishiev, G.,Aggarwal, M. M.,Ahammed, Z.,Alekseev, I.,Aparin, A.,Arkhipkin, D.,Aschenauer, E. C.,Ashraf, M. U.,Attri, A.,Averichev, G. S.,Bai, X.,Bairathi, V.,B American Physical Society 2016 Physical Review C Vol.94 No.1

        <P>We present measurements of the near side of triggered di-hadron correlations using neutral strange baryons ( A, (A) over bar) and mesons (K-s(0)) at intermediate transverse momentum ( 3 < p(T) < 6 GeV/c) to look for possible flavor and baryon-meson dependence. This study is performed in d+Au, Cu+Cu, and Au+Au collisions at root S-NN = 200 GeV measured by the STAR experiment at RHIC. The near-side di-hadron correlation contains two structures, a peak which is narrow in azimuth and pseudorapidity consistent with correlations from jet fragmentation, and a correlation in azimuth which is broad in pseudorapidity. The particle composition of the jet-like correlation is determined using identified associated particles. The dependence of the conditional yield of the jet-like correlation on the trigger particle momentum, associated particle momentum, and centrality for correlations with unidentified trigger particles are presented. The neutral strange particle composition in jet-like correlations with unidentified charged particle triggers is not well described by PYTHIA. However, the yield of unidentified particles in jet-like correlations with neutral strange particle triggers is described reasonably well by the same model.</P>

      • KCI등재

        Fungal biopriming increases the resistance of wheat to abiotic stress

        Ashraf S. A. El-Sayed,Hanan E. Dief,El-Sayed A. Hashem,Ahmed M. Desouky,Zamarud Shah,Salwa Fawzan 한국식물생명공학회 2022 JOURNAL OF PLANT BIOTECHNOLOGY Vol.49 No.2

        Increasing soil salinity is one of the global challenges that the agriculture sector in Egypt has been facing; 33% of the cultivated land in Egypt, which includes merely 3% of the entire land area, is already salinized. The present review sheds light on the role of fungal biopriming, a technique in which hydrated seeds are inoculated with beneficial fungal flora, in mitigating the deleterious influence of NaCl tension. Endophytic fungi were recognized to be able to interact with several plant species, markedly contributing to the mitigation of NaCl stress in these plants, such that some plants get impoverished to their absent associated microbes under stressful conditions

      • SCIESCOPUSKCI등재

        A Study of Some Economic Traits of Indigenous Cattle and their Crossbreeds in Southern Bangladesh

        Ashraf, A.,Islam, S.S.,Islam, A.B.M.M.,Ali, S.Z. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.9

        The experiment was conducted on 69 cows to identify the quantitative variations of some economic traits of five genetic groups as $Local{\times}Friesian $ $F_1$, $Local{\times}Sahiwal$ $F_1$, Local (indigenous zebu type), $Local{\times}Sindhi $ $F_1$, and $Local{\times}Hariana$ $F_1$. The traits studied were age at weaning, age at first heat, age at first conception, services per conception, daily milk yield, lactation length, lactation yield and post partum heat period. The records on milking and reproduction performances of cows and heifers were obtained from farm register and by interviewing the farmers. It was observed that the lowest age at weaning, age at first heat and age at first conception were $5.37{\pm}0.24$, $27.17{\pm}1.72$ and $27.83{\pm}1.82$ months respectively in $Local{\times}Hariana$ $F_1$. Services per conception were lowest in $Local{\times}Sahiwal$ $F_1$ $(1.08{\pm}0.18)$ although not significantly (p>0.05) affected by farms, genetic groups and $farm{\times}genetic$ groups interaction. Average daily milk yield was highest in $Local{\times}Friesian$ $F_1$ $(5.81 {\pm}0.40 kg)$. Lactation length and lactation yield were highest in $Local{\times}Sahiwal$ $F_1$ ($299.38{\times}9.74$ days and $1863.00{\pm}141.00kg $ respectively). Average post partum heat period was lowest in $Local{\times}Sindhi$ $F_1$ ($3.19{\pm}0.38$ months). Least squares ANOVA showed that farm had significant (p<0.001) effect on age at weaning, age at first heat, age at first conception and post partum heat period. There was insignificant (p>0.05) effect of farm on services per conception, daily milk yield, lactation length and lactation yield, whereas genetic groups had a significant effect for all the traits under review except services per conception. $Farm{\times}genetic$ groups interaction was insignificant for all of the traits under consideration except age at weaning.

      • SCISCIESCOPUS

        First macrocyclic 3<sup>rd</sup>-generation ALK inhibitor for treatment of ALK/ROS1 cancer: Clinical and designing strategy update of lorlatinib

        Basit, S.,Ashraf, Z.,Lee, K.,Latif, M. S.E.C.T. [etc.] ; Elsevier Science Ltd 2017 European journal of medicinal chemistry Vol.134 No.-

        Non-small cell lung cancers (NSCLC) harboring anaplastic lymphoma kinase (ALK) gene rearrangements invariably develop resistance to 2<SUP>nd</SUP>-generation ALK inhibitors. Lorlatinib (PF-06463922) (6) is a 3<SUP>rd</SUP>-generation macrocyclic ALK-TKI that demonstrates many advantages over 2<SUP>nd</SUP>-generation ALK inhibitors. Lorlatinib has demonstrated decent kinase selectivity, promising pharmacokinetic profile, selective brain-penetration and strong antiproliferative activity in several ALK/ROS1-driven tumor models. The current review describes the activity spectrum, key events from discovery to clinical applications and the evidences that lorlatinib acts as an ALK/ROS1 inhibitor in clinical settings.

      • SCIESCOPUS

        DNA Glycation from 3-Deoxyglucosone Leads to the Formation of AGEs: Potential Role in Cancer Auto-antibodies

        Ashraf, J. M.,Shahab, U.,Tabrez, S.,Lee, E. J.,Choi, I.,Aslam Yusuf, M.,Ahmad, S. HUMANA PRESS INC 2016 CELL BIOCHEMISTRY AND BIOPHYSICS Vol.74 No.1

        <P>The non-enzymatic glycation reaction results in the generation of free radicals which play an important role in the pathophysiology of aging, diabetes, and cancer. 3-Deoxyglucosone (3-DG) is a dicarbonyl species which may lead to the formation of advanced glycation end products (AGEs). 3-DG also reacts with free amino group of nucleic acids resulting in the formation of DNA-AGEs. While the establishment of nucleoside AGEs has been revealed before, no extensive studies have been done to probe the role of 3-DG in the generation of immunogenicity and induction of cancer auto-antibodies. In this study, we report the immunogenicity of AGEs formed by 3-DG-Arg-Fe3+ system. Spectroscopic analysis and melting temperature studies suggest structural perturbations in the DNA as a result of modification. Immunogenicity of native and 3-DG-Arg-Fe3+ DNA was probed in female rabbits. The modified DNA was highly immunogenic eliciting high-titer immunogen-specific antibodies, while the unmodified form was almost non-immunogenic. We also report the presence of auto-antibodies against 3-DG-Arg-Fe3+-modified DNA in the sera of patients with different types of cancers. The glycoxidative lesions were also detected in the lymphocyte DNA isolated from selected cancer patients. The results show structural perturbations in 3-DG-Arg-Fe3+-DNA generating new epitopes that render the molecule immunogenic.</P>

      • KCI등재

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