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Search Results: 1 - 10 of 9672 matches for " Refaz Ahmad Dar "
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Isolation, purification and characterization of carboxymethyl cellulase (CMCase) from endophytic Fusarium oxysporum producing podophyllotoxin  [PDF]
Refaz Ahmad Dar, Iram Saba, Mohd Shahnawaz, Manisha Kashinath Sangale, Avinash Bapurao Ade, Shabir Ahmad Rather, Parvaiz Hassan Qazi
Advances in Enzyme Research (AER) , 2013, DOI: 10.4236/aer.2013.14010
Abstract: Endophytic fungus Fusarium oxysporum is a rich source of cellulases. In the present study, the highest activity was reported at 28 ° C, pH 5.6 with 2% Carboxymethyl cellulose (CMC) as carbon source. CMC was purified using Sephadex G and DEAE cellulose chromatography to 15.9 folds and the molecular weight was determined to be 84 kDa by SDS-PAGE analysis and was subsequently characterized. The purified enzyme was stable over the pH range from 4.0 to 8.0 and at temperatures below 50 ° C. The enzyme was highly active on CMC and reduced or no activity on Avicel, cellobiose and it was suggested to be CMCase/endoglucanase. The activity of endoglucanase was enhanced in the presence of MgCl2, CoCl2, FeCl3, CaCl2, FeCl2 and intensive to HgCl2. The purified enzyme showed its optimum activity at pH 5.0 - 6.0 and was quite stable at 50 ° C for 30 min and retained 45% of original activity.
Mass Limit of Neutron Star  [PDF]
Jehangir Ahmad Dar
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.42036

The mass limit of neutron star has still remained a mystery. The existing Tolman-Oppenheimer-Volkoff (TOV) equation for calculating the limit always gives different values, by introducing different assumptions and having been predicted like 0.7 Mo, 3.2 Mo, 3.6 Mo, where Mo = 1.98 × 1030 Kg. There is a need of some better technique to adopt other than TOV relation to seek out the value. In this paper, a new relation between the mass of the collapsing star and its average density ρ has been derived and used to calculate the limit of neutron star. The conditions in radii between Schwarz Child’s radius and the actual radius of the collapsing star have been introduced to calculate the mass of star above which it will transform into a black hole and below it to a neutron star. A new constant, JN = 8.53707554

Breeding Strategies for Improving Rice Yield—A Review  [PDF]
Mudasir Hafiz Khan, Zahoor Ahmad Dar, Sher Ahmad Dar
Agricultural Sciences (AS) , 2015, DOI: 10.4236/as.2015.65046
Abstract: An increase in productivity is always one of the main goals of any crop breeding program including rice. However, many goals can be identified for this crop varying in importance from region to region, country to country, and even within a given country. Increase in grain yield potential is the major goal of almost all rice breeders programs. The major impacts are related to the development of new strategies to increase the genetic grain yield potential of the varieties. Rice breeders have been very successful in improving the crop. Some milestones are the contribution to the green revolution with the semi-dwarf varieties, the new rice plant type and hybrid rice. The main breeding method used to improve rice is the pedigree, but development of hybrids and population improvement are added to the breeder’s portfolio. Breeders have been taking advantage of biotechnology tools to enhance their breeding capacity; however, many programs are still struggling on how to integrate them into the breeding programs and how to balance the allocation of resources between conventional and modern tools.
Synchronous Adenocarcinomas of the Jejunum and Sigmoid Colon—A Rare Case  [PDF]
Nisar Ahmad Chowdri, Rayees Ahmad Dar, Munir Ahmad Wani, Fazl Qadir Parray
International Journal of Clinical Medicine (IJCM) , 2014, DOI: 10.4236/ijcm.2014.512090

Primary adenocarcinomas of the small bowel are rare. Because of their rarity, non-specific symptoms and diagnostic difficulty, small bowel tumors are often diagnosed and treated late in their course. The diagnostic difficulty is increased when these tumors arise in association with primary synchronous tumors of the colon. We present a case of a 17-year-old female who was evaluated for anemia and bleeding per rectum. Colonoscopy revealed multiple colonic polyps. Intraoperatively, she was surprisingly found to be having a synchronous jejunal growth apart from multiple colonic polyoid lesions. Total colectomy was performed along with resection of jejunal growth. Histopathology of colonic specimen revealed multiple polypoid projections with one polyp showing adenocarcinoma and rest severe dysplasia. Histopathology of jejunal growth revealed poorly-differentiated adenocarcinoma. Very rarely, cases have been reported in literature, where the primary adenocarcinoma of the jejunum developed synchronously with colonic adenocarcinoma, and both treated surgically on the same occasion.

Ceria-Based Mixed Oxide Supported CuO: An Efficient Heterogeneous Catalyst for Conversion of Cellulose to Sorbitol  [PDF]
Bashir Ahmad Dar, Sara Khalid, Tariq Ahmad Wani, Mushtaq Ahmad Mir, Mazahar Farooqui
Green and Sustainable Chemistry (GSC) , 2015, DOI: 10.4236/gsc.2015.51003
Abstract: A series of CeO2-Al2O3, CeO2-TiO2, CeO2-ZrO2, and CeO2-SiO2 mixed-oxide supported copper catalysts were prepared by a modified deposition-precipitation method from ultra dilute aqueous solutions and were investigated for hydrogenolysis of cellulose in aqueous medium, in the presence of hydrogen to produce sorbitol as major product. Among all the catalysts tested in the present work, CuO/CeO2ZrO2?catalyst proved to be the most promising with high conversion (92%) and excellent selectivity (sorbitol 99.1%), at an intermediate reaction temperature of 245°C in a neutral aqueous solution without an aid of liquid phase acid. The catalyst was recyclable in repeated runs and no deactivation was observed even after five reaction cycles. CuO/CeO2-ZrO2 has been characterized by XRD, SEM, TPR and BET surface area techniques.
Simultaneous trabeculectomy and cataract extraction
Ahmad Manzoor,Ahmad Gauhar,Dar Ghulam
Indian Journal of Ophthalmology , 1981,
Psoas Muscle Hydatid Cyst Causing Ureteric Compression and Hydronephrosis  [PDF]
Riyaz Ahmad Sheikh, Rayees Ahmad Dar, Sabiya Hamid Wani, Mushtaq Ahmad Gagloo, Suhail Farooq Mir, Gulzar Ahmad Bhat, Irfan Jan Khan
International Journal of Clinical Medicine (IJCM) , 2012, DOI: 10.4236/ijcm.2012.34058
Abstract: Psoas muscle is a rare location for hydatid disease. Here we present a case of infected hydatid cyst left psoas muscle presenting as left flank pain, fever, local flank tenderness, and raised blood counts. Preoperative diagnoses was made by Ultrasonography (USG) and Computed Tomography (CT) abdomen, although serology for hydatid disease was negative.
Polarographic Determination and Antimicrobial Activity of Cu(II) Complex with 4-Chlorobenzylidene-4-aminoacetanilide
Riyaz Ahmad Dar,Krishna Kumar Raj
Journal of Chemistry , 2012, DOI: 10.1155/2012/656598
Abstract: The electrochemical behaviour of the complex of Cu(II) with 4-chlorobenzylidene-4-aminoacetanilide (CAA) was studied. It was observed that CAA forms 1:1 complex with Cu(II) in between pH 6.5 to 7.1. It was found that the reduction process of Cu(II)- CAA complex is two electron reversible reduction process at D.M.E. The logarithm value of stability constant of Cu(II)-4-Chlorobenzylidene-4-aminoacetanilide (CAA) complex has been found to be 4.85.The redox properties of the complex was extensively investigated by electrochemical method using cyclic voltammetry (CV).The Cu(II) complexes exhibited quasi-reversible single electron transfer process.The Schiff base and its complex has been screened for their in-vitro antibacterial (Escherichiacoli, Staphylococcus aureus, Vibrio cholerae and Bacillus subtilis) and antifungal (Aspergillus niger and Penicillium liliacinum) activities by minimum inhibitory concentration (MIC) method.
Structural and Optical Studies of Magnesium Doped Zinc Oxide Thin Films
Journal of Nano- and Electronic Physics , 2013,
Abstract: The paper describes the structural and optical properties of Magnesium doped Zinc Oxide (Mg 3.5 %, 6 %, 9 %, 12 % by weight) thin films prepared by pulsed laser deposition technique. The samples are characterized by X-ray diffraction technique, Ultra-violet visible absorption spectroscopy, X-ray photoelectron spectroscopy. X-ray diffraction results reveal the polycrystalline nature of samples with no impurity or secondary phase formation. Ultra-violet visible absorption spectroscopy studies show the blue shift in the optical band gap subsequent to Mg doping. X-ray photoelectron spectroscopy results reveal the replacement of Zn2+ cation by Mg2+ ion.
Ceria-Based Mixed Oxide Supported Nano-Gold as an Efficient and Durable Heterogeneous Catalyst for Oxidative Dehydrogenation of Amines to Imines Using Molecular Oxygen
Bashir Ahmad Dar,Meena Sharma,Baldev Singh
Bulletin of Chemical Reaction Engineering & Catalysis , 2012, DOI: 10.9767/bcrec.7.1.1257.79-84
Abstract: The present work is intended to determine the catalytic activity of Mixed Oxide supported gold for aerobic oxidative dehydrogenation of amines to imines using Ceria as a main constituent of the each support. The model catalysts Au/CeO2:TiO2 Au/CeO2:SiO2, Au/CeO2:ZrO2 and Au/CeO2:Al2Os were prepared by deposition co-precipitation method and deposition of gold was determined by EDEX analysis. The supported nano-gold catalyzes the dehydrogenation of secondary amines to imines without loss of activity. On recycling good amount of product yield is obtained. Oxidation of secondary amines to imines is carried at 100 C and almost 90 % conversion was obtained with >99% selectivity. 2012 BCREC UNDIP. All rights reserved Received: 26th December 2011; Revised: 7th June 2012; Accepted: 13rd June 2012 [How to Cite: B.A. Dar, M. Sharma, B. Singh. (2012). Ceria-Based Mixed Oxide Supported Nano-Gold as an Efficient and Durable Heterogeneous Catalyst for Oxidative Dehydrogenation of Amines to Imines Using Molecular Oxygen. Bulletin of Chemical Reaction Engineering & Catalysis, 7(1): 79-84. doi:10.9767/bcrec.7.1.1257.79-84] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1257.79-84 ] | View in
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