35 research outputs found

    A REVIEW ON MATRIX ASSISTED LASER DESORPTION/INOZATION MASS SPECTROSCOPY

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    ABSTRACTMatrix assisted laser desorption ionization mass spectroscopy (MALDI-MS) is the most important technique of MS to analyze polymer systems. It isa special case of MS using specific sample preparation methods and low fluence laser desorption to create the analyte ions. This technique is basedupon an ultraviolet absorbing matrix. The matrix and the polymer are mixed at a molecular level in an appropriate solvent. The solvent helps preventaggregation of the polymer. The sample matrix mixture is placed on the sample probe tip, under vacuum conditions; the solvent is removed, leaving cocrystallizedpolymer molecules homogenously dispersed within matrix molecules. When the pulsed laser beam is tuned to the appropriate frequency,the energy is transferred to the matrix which is partially vaporized, carrying intact polymer into the vapor phase and charging the polymer chains inthe linear time of flight (TOF) analyzer. This review includes the detailed information of MALDI-MS, MALDI-TOF.Keywords: Matrix assisted laser desorption ionization mass spectroscopy, Principle, Sample preparation techniques, Matrix assisted laser desorptionionization - time of flight, Matrix assisted laser desorption ionization - mass spectrometric imaging, Applications

    Success Pattern Finding With Regards To Textual Content Exploration

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    Various algorithms such as Object Rank and PageRank, the latter created by Larry Page and used in Google Search Engine, were highly expensive as they required a PageRank style iterative computation over the full graph. BinRank, a hybrid algorithm proposed uses an index of pre computed results for some/or all keywords being used by the user Dynamic authority based online keyword search algorithms, such as Object rank and personalized page rank leverage semantic link in formation to provide high quality, high  recall search in databases and the web Conceptually, these  algorithms require a query time  page rank style iterative computation over the full graph. This computation is too  expensive for large graphs and not feasible at query time . Alternatively, building an index of pre computed results for some  or all keywords involves very expensive processing. We introduce  BinRank,a system that approximates ObjectRank results by utilizing a hybrid approach inspired by materialize d views in traditional query processing. The issue addressed in this paper is would like to provide an approach which intends to provide an approximation to BinRank by integrating it with Hubrank and parallelize i.e execute the activities simultaneously to reduce query execution time and also increase the relevance of the results. Bin Rank system which  approximates Object Rank results by utilizing a hybrid approach inspired by materialized views in traditional query  processing

    REVERSED PHASE-HIGH PERFORMANCE LIQUID CHROMATOGRAPHY METHOD DEVELOPMENT AND VALIDATION OF ATORVASTATIN IN BULK DRUG AND FORMULATION

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    Objective: To develop and validate a simple, selective, rapid, precise, and accurate high performance liquid chromatographic (HPLC) method fordetermination of atorvastatin in bulk and its pharmaceutical formulation product.Method: Reversed phase-HPLC (RP-HPLC) method was performed by a mobile phase consisting mixture of methanol and ammonium acetate buffer(pH 4.5) in the proportion 60:40 v/v. A ZORBAX Eclipse plus C(4.6 mm × 100 mm, 3.5 μ) column was used as a stationary phase. HPLC analysis ofatorvastatin was carried out at a wavelength of 241 nm with a flow rate of 1 ml/minute.18 Results: The linear regression analysis data for the calibration curve showed a good linear relationship with a correlation coefficient 0.9984. Thelinear regression equation was y=3726540.2x+27390388.1. This was found to give a sharp peak of atorvastatin at a retention time of 2.77 minutes.Validation parameters were evaluated for the method according to the ICH (Q2R1) guidelines. The limit of detection and limit of quantification for themethod were 0.6721 μg/mL and 1.9989 μg/mL, respectively. The % relative standard deviation values for intra-day precision and inter-day precisionwere found to be 0.31% and 0.30%, respectively. An accuracy of the method was determined through recovery studies which were found to be within97.57-102.22%.Conclusion: The method was validated for system suitability, accuracy, precision, robustness, and ruggedness. The precision, accuracy, sensitivityshort retention time and composition of the mobile phase indicated that this method is better than the earlier methods developed for the quantificationof atorvastatin.Keywords: Atorvastatin, Reversed phase-high performance liquid chromatographic method development, Validation

    ASSOCIATION BETWEEN MICROALBUMINURIA AND OXIDATIVE STRESS IN DIABETIC NEPHROPATHY

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    Objectives: Diabetic Nephropathy (DN) is a leading cause of chronic kidney disease and end stage renal failure worldwide. This study aimed to evaluate the association between oxidants, antioxidants and microalbuminuria in Diabetic Nephropathy compared with Type II Diabetes Mellitus (DM). Methods: The study includes 60 Type II Diabetes Mellitus and 40 Diabetic Nephropathy Patients. Parameters performed HbA1c, urea, creatinine, total proteins, microalbuminuria, glutathione peroxidase and malondialdehyde(MDA). Results: The levels of HbA1c, urea, creatinine, microalbuminuria and malondialdehyde are significantly higher in DN compared with Type II DM. the levels of T.P and glutathione peroxidase are decreased in DN compared with Type II DM. Conclusion: Low levels of glutathione peroxidase and total proteins were observed in DN. HbA1c, urea, creatinine, microalbuminuria and malondialdehyde levels were elevated in DN compared with Type II DM.KEYWORDS: Diabetic Nephropathy; Glutathione peroxidase; Microalbuminuria; Malondialdehyde

    ASSOCIATION BETWEEN MICROALBUMINURIA AND OXIDATIVE STRESS IN DIABETIC NEPHROPATHY

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    Objectives: Diabetic Nephropathy (DN) is a leading cause of chronic kidney disease and end stage renal failure worldwide. This study aimed to evaluate the association between oxidants, antioxidants and microalbuminuria in Diabetic Nephropathy compared with Type II Diabetes Mellitus (DM). Methods: The study includes 60 Type II Diabetes Mellitus and 40 Diabetic Nephropathy Patients. Parameters performed HbA1c, urea, creatinine, total proteins, microalbuminuria, glutathione peroxidase and malondialdehyde(MDA). Results: The levels of HbA1c, urea, creatinine, microalbuminuria and malondialdehyde are significantly higher in DN compared with Type II DM. the levels of T.P and glutathione peroxidase are decreased in DN compared with Type II DM. Conclusion: Low levels of glutathione peroxidase and total proteins were observed in DN. HbA1c, urea, creatinine, microalbuminuria and malondialdehyde levels were elevated in DN compared with Type II DM.KEYWORDS: Diabetic Nephropathy; Glutathione peroxidase; Microalbuminuria; Malondialdehyde

    DEVELOPMENT AND VALIDATION OF UV SPECTROPHOTOMETRIC AND REVERSED PHASE‑HIGH PERFORMANCE LIQUID CHROMATOGRAPHY ‑ PDA METHODS FOR THE ESTIMATION OF ALOGLIPTIN BENZOATE

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    Objective: To develop and validate simple, rapid, precise, accurate, and economical UV spectrophotometric and reverse phase high performanceliquid chromatographic methods for the estimation of alogliptin benzoate (AGP).Methods: UV spectrophotometric method was performed using UV/Vis double beam spectrophotometer with a spectral bandwidth of 1 nm and1.0 cm matched quartz cells. The maximum absorbance of AGP was observed at 276 nm using methanol as solvent. Reversed phase-high performanceliquid chromatography (RP-HPLC) method was carried out on a Unisol reverse phase C18 column (150 mm × 4.6 mm, 3 μm) with a mobile phasecomposed of methanol and 10 mM ammonium acetate buffer (adjusted to pH 5.0 with glacial acetic acid) in the ratio of 80:20 v/v with a flow rate of0.8 ml/minutes.Results: The linearity of methods was found to be in the range of 5-35 µg/ml (UV) and 20-100 µg/ml (RP-HPLC) and the correlation coefficient was0.999 for both the methods. The regression equations were y = 0.028x + 0.023 (UV) and y = 28,58,942x - 4,33,647 (HPLC). The retention time of AGPwas 2.37 minutes.Conclusion: The proposed methods were validated in terms of linearity, precision, accuracy, specificity, robustness, limit of detection, and limit ofquantitation as per International Conference on Harmonization Q2 R1 guidelines. Thus, the proposed methods are novel, sensitive, and reliable andcan be successfully used for the quantitation of AGP.Keywords: Alogliptin benzoate, UV-visible spectrophotometer, Reversed phase-high performance liquid chromatography, International Conferenceon Harmonization guidelines

    DEVELOPMENT AND VALIDATION OF STABILITY INDICATING REVERSE PHASE HIGH‑PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE ESTIMATION OF PIRIBEDIL IN BULK DRUG

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    ABSTRACTObjective: A simple, precise, fast, economic, accurate, robust, and stability indicating isocratic reverse phase high-performance liquid chromatographicmethod was developed for the analysis of Piribedil.Method: The chromatographic conditions were standardized using Unisol C-18 (4.6 × 150 mm × 3.0 μ) column with UV detection at 244 nm, and themobile phase composed of methanol:acetate buffer-pH 5.0 (85:15, v/v).Results: The retention time of Piribedil was found to be 3.4 minutes. The calibration curve was linear with correlation coefficient of 0.999 over aconcentration range of 20-100 μg/ml with linear regression equationy=74,69,224.37x−39,46,924.90. The limit of detection and limit of quantitationwere found to be 0.04 and 0.4 μg/ml, respectively.Conclusion: The proposed method has been validated according to the ICH guidelines. Piribedil was subjected to stress conditions includingacidic, alkaline, oxidation, photolysis, and thermal degradation. Piribedil is more sensitive to photolytic stress. There are no interfering peaks fromdegradation products at analyte retention time, and thus the method is specific for the estimation of Piribedil in the presence of degradation products.Thus, the proposed method can be successfully applied in the routine quality control and stability samples of Piribedil in bulk drug.Keywords: Piribedil, Validation, Stability indicating, Reverse phase high-performance liquid chromatographic

    Impact of xylan on field productivity and wood saccharification properties in aspen

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    Xylan that comprises roughly 25% of hardwood biomass is undesirable in biorefinery applications involving saccharification and fermentation. Efforts to reduce xylan levels have therefore been made in many species, usually resulting in improved saccharification. However, such modified plants have not yet been tested under field conditions. Here we evaluate the field performance of transgenic hybrid aspen lines with reduced xylan levels and assess their usefulness as short-rotation feedstocks for biorefineries. Three types of transgenic lines were tested in four-year field tests with RNAi constructs targeting either Populus GT43 clades B and C (GT43BC) corresponding to Arabidopsis clades IRX9 and IRX14, respectively, involved in xylan backbone biosynthesis, GATL1.1 corresponding to AtGALT1 involved in xylan reducing end sequence biosynthesis, or ASPR1 encoding an atypical aspartate protease. Their productivity, wood quality traits, and saccharification efficiency were analyzed. The only lines differing significantly from the wild type with respect to growth and biotic stress resistance were the ASPR1 lines, whose stems were roughly 10% shorter and narrower and leaves showed increased arthropod damage. GT43BC lines exhibited no growth advantage in the field despite their superior growth in greenhouse experiments. Wood from the ASPR1 and GT43BC lines had slightly reduced density due to thinner cell walls and, in the case of ASPR1, larger cell diameters. The xylan was less extractable by alkali but more hydrolysable by acid, had increased glucuronosylation, and its content was reduced in all three types of transgenic lines. The hemicellulose size distribution in the GALT1.1 and ASPR1 lines was skewed towards higher molecular mass compared to the wild type. These results provide experimental evidence that GATL1.1 functions in xylan biosynthesis and suggest that ASPR1 may regulate this process. In saccharification without pretreatment, lines of all three constructs provided 8-11% higher average glucose yields than wild-type plants. In saccharification with acid pretreatment, the GT43BC construct provided a 10% yield increase on average. The best transgenic lines of each construct are thus predicted to modestly outperform the wild type in terms of glucose yields per hectare. The field evaluation of transgenic xylan-reduced aspen represents an important step towards more productive feedstocks for biorefineries
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