Imidazole Chloramine-B Oxidation kinetics Mechanism Activation parameters Structure reactivity Int

2-(20 -Pyridyl)benzimidazole (PBIMH) was functionalized onto chloromethylated polystyrene beads crosslinked with 6.5 % divinylbenzene, and this solid support was then reacted with Na2PdCl4 in methanol. The functionalized beads were then activated using sodium borohydride. The resultant polymer-supported [2-(20 - pyridyl)benzimidazole]palladium complex (PSDVB– PBIM–PdCl2) and its activated form were characterized by various physicochemical techniques. XPS studies con- firmed the ?2 oxidation state of palladium in the supported complex. The activated complex was found to catalyse the hydrogenation of various organic substrates including olefins, nitro and Schiff base compounds. Kinetic measurements for the hydrogenation of cyclopentene, cyclohexene and cyclooctene were carried out by varying temperature, catalyst and substrate concentration. The energy and entropy of activation were evaluated from the kinetic data. The catalyst showed an excellent recycling efficiency over six cycles without leaching of metal from the polymer support, whereas the unsupported complex was unstable as metal leached out into the solution during the first run

A polymer-supported diacetatobis(2-quinolylbenzimidazole)copper(II) complex as an efficient catalyst for oxidation of alcohols with tert-butyl hydroperoxide

A polymer-supported diacetatobis(2-quinolylbenzimidazole)copper(II) complex PS-(QBIM)2Cu(II) was synthesized by functionalization of chloromethylated polystyrene cross-linked with 6.5 % divinyl benzene with 2-(2â²-quinolyl)benzimidazole and subsequent treatment with Cu(OAc) 2 in methanol. The complex was characterized by physical, analytical and spectroscopic techniques. Electronic and ESR spectra, together with magnetic susceptibility measurements, indicated that the complex was paramagnetic with distorted octahedral geometry around the copper. The complex was found to be active toward oxidation of various alcohols including phenol, benzyl alcohol and cyclohexanol using 70 % aqueous tert-butyl hydroperoxide under mild conditions. Under the optimized reaction conditions, cyclohexanol gave 100 % conversion to cyclohexanone, benzyl alcohol gave 98 % yield of benzaldehyde and phenol gave 89 % yield of catechol and 4 % of hydroquinone. The complex was recycled five times without much loss in catalytic activity. © 2012 Springer Science+Business Media Dordrecht

Liquid-Phase Catalytic Oxidation of Organic Substrates by a Recyclable Polymer-Supported copper(II) Complex

Chloromethylated polystyrene beads cross-linked with 6.5 % divinylbenzene were functionalized with 2-(2′-pyridyl) benzimidazole (PBIMH) and on subsequent treatment with Cu(OAc)2 in methanol gave a polymer-supported diacetatobis(2-pyridylbenzimidazole)copper(II) complex [PS-(PBIM)2Cu(II)], which was characterized by physicochemical techniques. The supported complex showed excellent catalytic activity toward the oxidation of industrially important organic compounds such as phenol, benzyl alcohol, cyclohexanol, styrene, and ethylbenzene. An effective catalytic protocol was developed by varying reaction parameters such as the catalyst and substrate concentrations, reaction time, temperature, and substrate-to-oxidant ratio to obtain maximum selectivity with high yields of products. Possible reaction mechanisms were worked out. The catalyst could be recycled five times without any metal leaching or much loss in activity. This catalyst is truly heterogeneous and allows for easy work up, as well as recyclability and excellent product yields under mild conditions

Polymer immobilized Fe(III) complex of 2-phenylbenzimidazole: An efficient catalyst for photodegradation of dyes under UV/Visible light irradiation

Fe(III) complex of 2-phenylbenzimidazole has been covalently anchored on polymer and characterized by elemental analysis, FT-IR, far-IR, BET surface area measurements, UV-Vis/DRS spectroscopy, thermo-gravimetric analysis and magnetic moment measurements by VSM which confirmed an octahedral environment around Fe(III) in the bound complex. The photocatalytic performance of this complex was evaluated in the photodegradation of dyes in presence of H2O2 as an oxidizing agent. Suitable reaction conditions have been optimized by considering the effects of various reaction parameters such as pH, oxidants, concentration of dye, H2O2 and catalyst for the maximum degradation of dye. The photodegradation was found to be 100 with complete mineralization in 150 min. The comparison of photocatalytic efficiency of the catalyst under visible light, sunlight and dark conditions are accomplished. Comparison between catalytic activity of the polymer-supported complex and unbound complex demonstrated that the polymer-supported complex was more active. Photocatalytic performance of PS-Fe(III)PBMZL was also compared with commercial TiO2 (P25). This heterogeneous complex retained its activity up to 8 runs. A tentative mechanism has been proposed. © 2017 King Saud University

Client Side Privacy Protection Using Personalized Web Search

AbstractWe are providing a Client-side privacy protection for personalized web search.. Any PWS captures user profiles in a hierarchical taxonomy. The system is performing online generalization on user profiles to protect the personal privacy without compromising the search quality and attempt to improve the search quality with the personalization utility of the user profile. On other side they need to hide the privacy contents existing in the user profile to place the privacy risk under control. User privacy can be provided in form of protection like without compromising the personalized search quality. In general we are working for a trade off between the search quality and the level of privacy protection achieved from generalization

Zeolite-Y encapsulated VO[2-(2′hydroxyphenyl)benzimidazole] complex: investigation of its catalytic activity towards oxidation of organic substrates

Zeolite-Y encapsulated VO(IV)2-(2′-hydroxyphenyl)benzimidazole (ohpbmzl) was synthesized by flexible ligand approach and characterized using various physico-chemical techniques such as elemental analysis, XRD, inductively coupled plasma-atomic emission, fourier transform infrared spectroscopy, UV–vis-diffuse reflectance and electron paramagnetic resonance spectroscopy, thermogravimetric analysis, BET surface area and cyclic voltammetry (CV). Based on the results a square pyramidal structure was suggested for the encapsulated complex. Shift in UV absorbance to higher wavelength and variations in the redox potential values compared to the non-encapsulated complex in CV confirmed the successful encapsulation of the complex in the zeolite matrix. The catalytic efficacy was investigated towards oxidation of phenol, styrene, cyclohexane and ethyl benzene in acetonitrile using H2O2 as oxidant. Influence of reaction parameters like catalyst and substrate concentration, substrate/H2O2 molar ratio, and temperature were investigated to optimize the reaction conditions for maximum substrate conversion and selectivity towards desired products using the encapsulated complex. The catalytic activity was compared with vanadyl exchanged zeolite-Y (VO-Y) and non-encapsulated complex. The encapsulated complex retained its stability up to 3 runs as confirmed by recycling studies. Mechanistic pathways were proposed for all the probe reactions

Evaluation of protein: creatinine ratio on random urine samples in assessment of proteinuria

Background: Significant proteinuria (>300mg/day) may indicate the presence of important renal disease. Quantitative estimation of urinary protein over 24 hours is the gold standard test for detection of proteinuria. However, 24 hours urine collection method is inconvenient and cumbersome to patients. The present study was undertaken to determine diagnostic accuracy of random urine protein: creatinine ratio for the diagnosis of proteinuria among patients with renal diseases.Methods: The prospective study was done in 200 nephropathy cases. The 24 hours urinary protein test used as gold standard test and compared with their random urine sample protein: creatinine ratio (cut off >0.3). The data analyzed for sensitivity, specificity and accuracy of random urine sample protein: creatinine ratio test.Results: Random urine sample protein: creatinine ratio test showed sensitivity, specificity and accuracy of 95.6%, 94.4% and 95.5% respectivelyConclusions: The convenient and accurate protein: creatinine ratio method on random urine samples is reliable method for estimation and screening the proteinuria cases over quantification of proteinuria by collection of 24 hours urine samples and hence, a wider application of this method is recommended

Evaluation of hemoglobin estimation with non-cyanide alkaline haematin D- 575 method

Background: Anemia is serious cause for concern in the world as it impacts on psychological and physical development, behavior and work performance. There are various methods recommended for estimation of hemoglobin for detection of anemia. Each method has its advantages and disadvantages. Aims and objectives of the present study were to compare conventional Hemoglobinocynide (HiCN) method containing potassium ferricyanide and potassium or sodium cyanide with non- cyanide alkaline haematin Method for hemoglobin estimation.Methods: The prospective study was conducted to evaluate the performance of two methods - HiCN method with Drabkin’s reagent and non- cyanide alkaline haematin method with AHD 575 reagent, for hemoglobin determination utilizing 201 blood samples. The data statistically analyzed by using coefficient of variation (CV), linear regression and mean differences.Results: A good correlation was observed for hemoglobin estimation between the HiCN method and non-cyanide alkaline haematin Method with AHD 575 reagent. The correlation coefficient of r= 0.9998 was statistically significant.Conclusions: It was concluded that both methods are accurate and precise, however the toxic and biohazardous effects of potassium ferricyanide and sodium cyanide in HiCN method can be prevented by using alkaline haematin method with AHD 575 reagent

Analysis of cerebrospinal fluid adenosine deaminase levels in meningitis

Background: A precise etiological diagnosis of meningitis is required so that appropriate therapy can be started at the earliest. Due to inconsistent clinical presentations and the lack of a rapid, sensitive and specific test, tuberculous meningitis (TBM) is particularly difficult to diagnose. The present study was done to analyze the utility of adenosine deaminase (ADA) activity in CSF for differentiating TBM from other forms of meningitis.Methods: In our study, ADA activity measured in 26 TBM, 15 pyogenic meningitis (PM) and 10 aseptic/viral meningitis (AM) cases. A cut-off ADA level of 10 IU/L was used for differentiation of TBM cases from other meningitis cases.Results: The mean ADA levels in CSF were highest in TBM patients as compared to PM and AM. The sensitivity, specificity and accuracy of ADA were 96.15%, 92% and 94.11% respectively for detection TBM cases from non-tuberculous meningitis cases.Conclusions: Since ADA test is simple, rapid and inexpensive, it can be used as rapid diagnostic test for differential diagnosis of CSF and confirmation of TBM cases.              

Utility of peripheral blood smear in platelet count estimation

Background: There are several methods of platelet count used in hematology laboratory. These methods are manual counting, automated hematology analyzer counting, platelet count estimation by peripheral blood smear (PBS) method etc. Many diseases such as dengue, malaria, pregnancy induced hypertension etc. may leads to severe thrombocytopenia. Timely and precise diagnosis of platelet count plays very crucial role in critical care management of thrombocytopenia cases. The present study was undertaken to estimate platelet counts by PBS method and correlate them with results from automated hematology analyzer method.Methods: Study included one hundred randomly collected blood samples in EDTA anticoagulant vacutainer tubes. Each blood sample was processed for platelet count estimation with automated hematology analyzer and Leishman’s stained PBS examination. The statistical analysis was done by using Pearson's correlation test to access the agreement between both the methods.Results: The Pearson's correlation test showed significant positive correlation for platelet count estimation between both the methods. (r =0.9789).Conclusions: Platelet count estimation by PBS method is reliable and statistically significant when compared to hematology analyzer method. PBS platelet estimation method can be taken as early and rapid procedure for platelet assessment in critical severe thrombocytopenia cases. This method is simple, cheaper and can be done in rural hospital setup where automation is not available