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1.
J Biomol Struct Dyn ; 41(20): 11274-11285, 2023 12.
Article in English | MEDLINE | ID: mdl-36562209

ABSTRACT

Resistance to antibiotics/antibacterials/antifungals in pathogenic microbes has been developing over the past few decades and has recently become a commonplace public-health peril. Thus, alternative nontoxic potent antibiotic agents are covertly needed to control antibiotic-resistant outbreaks. In an effort to combat the challenges posed by the co-occurrence of multidrug resistance, two terpyridine ligands 4'-(4-N,N'-dimethylaminophenyl)-2,2':6',2″-terpyridine (L1) and 4'-(4-tolyl)-2,2':6',2″-terpyridine (L2) have been designed, prepared and confirmed their structure by spectral studies. Thereafter, antimicrobial assay was performed against gram positive and negative bacterial strains along with fungal strains. Both compounds L1 and L2 exhibited remarkable inhibitory activities against bacteria, Escherichia coli and Staphylococcus aureus at MIC values 6.25 and 3.125 µg/ml, respectively. In addition, in silico molecular docking studies were ascertained with bacterial DNA gyrase and fungal demethylase. Furthermore, both L1 and L2 could bind Bovine Serum Albumin (BSA) protein and binding interaction has been studied with the help of UV-Visible and fluorescence spectroscopy. While fluorescence of BSA unperturbed in the presence of L2, an addition of L1 to the solution of BSA resulted significant quenching. The binding constant calculations at different temperature confirmed that the fluorescence quenching between BSA and L1 is predominantly static in nature. The toxicity of L1 and L2 was checked using Drosophila melanogaster. The toxicity analysis suggest both the dyes are non-cytotoxic in nature.Communicated by Ramaswamy H. Sarma.


Subject(s)
Antifungal Agents , Drosophila melanogaster , Animals , Molecular Docking Simulation , Antifungal Agents/pharmacology , Drosophila melanogaster/metabolism , Spectrometry, Fluorescence/methods , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Serum Albumin, Bovine/chemistry , Ligands , Microbial Sensitivity Tests
2.
J Indian Inst Sci ; 102(1): 91-116, 2022.
Article in English | MEDLINE | ID: mdl-35345876

ABSTRACT

The strength-ductility trade-off is an eminent factor in deciding the mechanical performance of a material with regard to specific applications. The strength-ductility synergy is generally inadequate in as-synthesized high entropy alloys (HEAs); however, it can be tailored owing to its tunable microstructure and phase stability. Thermo-mechanical processing (TMP) allows the microstructure to be tailored to achieve desired strength-ductility combination. The additional attribute is evolution of texture, which also significantly influences the mechanical properties. This review presents a critical insight into the role of TMP to achieve superior strength-ductility symbiosis at room temperature in single-phase (FCC, BCC) and multiphase HEA. The role of overall processing strategy of HEAs encompassing rolling and subsequent annealing in relation to the evolution of microstructure and texture in have been discussed. Recently practiced severe plastic deformation processes have also shown promise in improving the strength-ductility combination. The relevance of these processes in the processing of HEAs has also been analysed. At the end, futuristic approaches have been elaborated to enable efficient as well as hassle-free process towards achieving the proficiency of strength-ductility in HEAs.

3.
Curr Res Food Sci ; 4: 421-428, 2021.
Article in English | MEDLINE | ID: mdl-34195623

ABSTRACT

The objective of this work is to develop a microwave assisted-ultraviolet (MW-UV) digestion in the presence of dilute HCl and H2O2 followed by ion chromatography (IC) measurements for the determination of total nitrogen in cereals. This approach (MW-UV-IC) requires lesser time and does not need environmentally hazardous materials as used in Kjeldhal method. Further, the developed method requires only microliter quantities of dilute HCl and few milliliters of H2O2 for the matrix digestion and simultaneous conversion of nitrogen to its ionic species for the subsequent analysis by IC. At the optimized acid concentrations (200 â€‹µL of 0.1 â€‹mol â€‹L-1 HCl) and microwave power, the nitrogen in the cereals flours is converted to nitrate (NO3 -), nitrite (NO2 -) and ammonium (NH4 +) ions. The nitrogen species were separated using IonPac AS-20 and IonPac CS-17 columns and then quantified using suppressed conductivity detection. The method was applied to estimate the total nitrogen in flours of various cereals like; wheat (Triticum aestivum), rice (Oryza sativa), finger millet (Eleusine coracana), jowar (Sorghum) and pearl millet (Pennisetum glaucum). The results obtained using proposed method, were in good agreement with that of Kjeldhal method. Further, the precision of the values obtained by developed method was on par with the Kjeldhal method for all the tested flours as verified by F-test (n â€‹= â€‹5 and 95% confidence limit). Additionally, greenness assessment tools like analytical Eco-scale and green analytical procedure index (GAPI) suggested the proposed MW-UV-IC method, for the determination of total nitrogen in cereal flours, to be excellently green and safe.

4.
Diabet Med ; 37(6): 934-944, 2020 06.
Article in English | MEDLINE | ID: mdl-32181959

ABSTRACT

AIMS: To explore the qualitative literature on the perceived factors, positive and negative, affecting participation by children and adolescents with type 1 diabetes in physical activity, from the perspective of children and adolescents with type 1 diabetes, their family members, teachers or sports coaches, and healthcare professionals. METHODS: MEDLINE, SPORTDiscus, PsycINFO, CINAHL and Scopus were systematically searched in July 2019. Eligible studies included any that reported qualitative findings on the perceived factors that affect participation in physical activity from either the perspective of children or adolescents with type 1 diabetes, their family members, teachers or coaches, and healthcare professionals. RESULTS: The literature search yielded a total of 7859 studies, of which 14 (13 qualitative studies and one mixed-methods study) met the review inclusion criteria. In total there were 12 unique populations containing 270 individuals, 105 children or adolescents with type 1 diabetes,108 family members, 37 teachers and 20 healthcare professionals. The main factors thought to influence physical activity for this population were the individual characteristics of children and adolescents, the requirement for self-blood glucose regulation, support systems including friends, family, teachers and professionals, education and knowledge, and communication. CONCLUSIONS: This review synthesizes views on the perceived factors from several different perspectives. The findings suggest that it is important to consider the needs of the wider support network, as well as the child's or adolescent's concerns and preferences, when developing new or existing strategies and programmes to promote physical activity in children and adolescents with type 1 diabetes.


Subject(s)
Diabetes Mellitus, Type 1 , Exercise , Adolescent , Child , Family , Health Personnel , Humans , Qualitative Research , School Teachers , Social Support
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 228: 117805, 2020 Mar 05.
Article in English | MEDLINE | ID: mdl-31787536

ABSTRACT

Herein, we report a method for the synthesis of 4-aminohippuric acid (4-AHA) reduced/stabilized gold nanoparticles and their peroxidase mimicking properties for the colorimetric detection of Fe3+ and Hg2+. The synthesis of nanoparticles was evidenced by appearance of bright red color and an absorption peak at 518 nm. Transmission electron microscopic (TEM) characterization revealed the nanoparticles to be spherical with average size of about 5.9 ± 1.7 nm. X-ray diffraction (XRD) analysis established highly crystalline nature of the nanoparticles. The synthesized nanoparticles have shown very good peroxidase mimicking property; exhibiting the catalytic oxidation of the chromogen 3,3',5,5'-tetramethyl benzidine (TMB) to a blue color product, in the presence of hydrogen peroxide. The peroxidase mimicking activity of the nanoparticles was found to be selectivity enhanced in the presence of Fe3+ and Hg2+ while there was no change in the activity in the presence of other concomitant ions. The mechanism studies revealed that the synthesized gold nanoparticles assisted in electron transfer during the catalytic process however the stimulation of peroxidase-like activity in the presence of Fe3+ and Hg2+ is owed to both generation of hydroxyl radical and accelerated electron transfer. The assay was made selective for iron by the addition of cysteine in acetate buffer; whereas the selective detection of mercury was achieved by carrying out the assay in citrate buffer. The linear ranges for the determination of Fe3+ and Hg2+ in deionized water were found to be: 5-50 ppb and 5-200 ppb respectively. The limits of quantification (LOQ) for Fe3+ and Hg2+ were 4.0 and 2.5 ppb respectively. The assay was applied for the determination of Fe3+ and Hg2+ in drinking and ground water samples. The method holds potential for the on-field screening of these metal ions in real environmental samples.


Subject(s)
Gold/chemistry , Groundwater/analysis , Iron/analysis , Mercury/analysis , Metal Nanoparticles/chemistry , Peroxidase/chemistry , p-Aminohippuric Acid/chemistry , Colorimetry
7.
Indian J Dermatol ; 60(4): 419, 2015.
Article in English | MEDLINE | ID: mdl-26288422

ABSTRACT

BACKGROUND: Acne vulgaris is known to impair many aspects of the quality of life (QoL) of its patients. AIM: To translate the Cardiff Acne Disability Index (CADI) from English into Hindi and to assess its validity and reliability in Hindi speaking patients with acne from India. METHODS: Hindi version of CADI, translated and linguistically validated as per published international guidelines, along with a previously translated Hindi version of dermatology life quality index (DLQI) and a demographic questionnaire were administered to acne patients. The internal consistency reliability of the Hindi version of CADI and its concurrent validity were assessed by Cronbach's alpha co-efficient and Spearman's correlation co-efficient respectively. Construct validity was examined by factor analysis. Statistical analysis was carried out using the Statistical Package for the Social Sciences (SPSS) version 20 (SPSS Inc., Chicago, IL, USA) for Windows. RESULTS: One hundred Hindi speaking patients with various grades of acne participated in the study. Hindi version of CADI showed high internal consistency reliability (Cronbach's alpha co-efficient = 0.722). Mean item-to-total correlation co-efficient ranged from 0.502 to 0.760. Concurrent validity of the scale was supported by a significant correlation with the Hindi DLQI. Factor analysis revealed the presence of two dimensions underlying the factor structure of the scale. CONCLUSION: Hindi CADI is equivalent to the original English version and constitutes a reliable and valid tool for clinical assessment of the impact of acne on QoL.

9.
Talanta ; 131: 505-9, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25281133

ABSTRACT

A method has been developed for the determination of traces of arsenic, boron, bismuth, gallium, germanium, phosphorus, lead, antimony, selenium, silicon and tellurium in nickel matrix. The sample was dissolved in HClO4 (~ 150°C) and nickel was settled as crystalline nickelperchlorate [Ni(ClO4)2] on cooling. The mixture was ultrasonicated and after the separation of Ni(ClO4)2, analytes of interest were determined in the supernatant using ICP-OES. Similarly, it was also found that, after the dissolution of nickel in perchloric acid, when the solution temperature was maintained at ~ 100°C, long needle like crystals of nickel perchlorate were formed. The crystals were separated from the mixture and trace elements in the supernatant were determined using ICP-OES. In both methods the matrix removal was >99% and the recoveries of analytes were in the range 92-97%. The limits of detection for As, B, Bi, Ga, Ge, P, Pb, Sb, Se, Si and Te were found to be 0.18, 0.21, 0.07, 0.06, 0.25, 0.11, 0.09, 0.10, 0.17, 0.20 and 0.07 µg g(-1) respectively. The procedure was applied for the analysis of a standard reference material nickel oxide (SRM 761, Nickel Oxide No.1, NBS, USA) and the values obtained are in close agreement with the certified values.

10.
Int J Trichology ; 6(4): 190-1, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25368482
12.
J Pharm Anal ; 3(3): 180-186, 2013 Jun.
Article in English | MEDLINE | ID: mdl-29403814

ABSTRACT

The quantitative analysis of glutathione (GSH) is important in different fields like medicine, biology, and biotechnology. Accurate quantitative measurements of this analyte have been hampered by the lack of well characterized reference standards. The proposed procedure is intended to provide an accurate and definitive method for the quantitation of GSH for reference measurements. Measurement of the stoichiometrically existing sulfur content in purified GSH offers an approach for its quantitation and calibration through an appropriate characterized reference material (CRM) for sulfur would provide a methodology for the certification of GSH quantity, that is traceable to SI (International system of units). The inductively coupled plasma optical emission spectrometry (ICP-OES) approach negates the need for any sample digestion. The sulfur content of the purified GSH is quantitatively converted into sulfate ions by microwave-assisted UV digestion in the presence of hydrogen peroxide prior to ion chromatography (IC) measurements. The measurement of sulfur by ICP-OES and IC (as sulfate) using the "high performance" methodology could be useful for characterizing primary calibration standards and certified reference materials with low uncertainties. The relative expanded uncertainties (% U) expressed at 95% confidence interval for ICP-OES analyses varied from 0.1% to 0.3%, while in the case of IC, they were between 0.2% and 1.2%. The described methods are more suitable for characterizing primary calibration standards and certifying reference materials of GSH, than for routine measurements.

13.
Analyst ; 137(3): 668-74, 2012 Feb 07.
Article in English | MEDLINE | ID: mdl-22159184

ABSTRACT

Accurate quantification of deoxyribonucleic acid (DNA) is critical for many analyses in molecular biology and genetic tests. We present a method in which the stoichiometrically existing phosphorus content in purified genomic DNA is quantitatively converted into orthophosphate ions by microwave assisted-UV digestion in the presence of microlitre quantities of dilute reagents (HCl, HNO(3), H(2)O(2)). The tandem use of microwave energy and ultraviolet photons for DNA digestion in pressurized quartz vessels enables a maximum reaction temperature of 240 °C resulting in efficient and fast mineralization of high molecular weight DNA within 30 minutes. Compared to hotplate digestion, the digestion time is reduced by a factor of 32. The MW-UV sample preparation approach coupled with the ion chromatographic measurement of phosphate using a high performance (HP) methodology provides an accurate quantitation of phosphorus mass fractions as low as 0.3 µg g(-1), corresponding to a DNA mass of 25 µg. The relative expanded uncertainties (% U) expressed at 95% confidence for these analyses range from 0.2 to 0.6%. Critically, the matrix of the calibrant solution is also matched with respect to the digested matrix anions (chloride, nitrate), without which significant bias in IC performance is observed. The phosphorus content of the calf thymus DNA was also measured using high-performance inductively coupled plasma optical emission spectroscopy (HP-ICP-OES), which provided independent data for comparison with the MW-UV digestion-IC based approach. Ion chromatography requires smaller volume of materials to perform the analysis and could be useful for characterizing primary calibration standards and certified reference materials with low uncertainties.


Subject(s)
Chromatography, Liquid/methods , DNA/analysis , Microwaves , Phosphorus/analysis , Calibration , Reproducibility of Results , Ultraviolet Rays
14.
Anal Chim Acta ; 584(1): 210-4, 2007 Feb 12.
Article in English | MEDLINE | ID: mdl-17386606

ABSTRACT

The use of boric acid as a modifier for the determination of trace amount of rubidium in high purity cesium chloride matrix by electrothermal atomic absorption is described. It was found that the negative influence of the chloride matrix could not be eliminated using stabilized temperature platform (STPF) alone. Due to the high dissociation energy (D(0)=427 kJ mol(-1)) of rubidium chloride, it was difficult to dissociate in the gas phase and hence is lost. Elimination of interferences was achieved by the addition of boric acid as a chemical modifier. Diluted cesium chloride samples (5%, m/v) were analyzed applying the standard addition method. The characteristic mass of 24 pg was obtained. The detection limit of the proposed method is around 26 ng g(-1). The developed method was applied to the determination of traces of rubidium in high purity cesium chloride samples. The data obtained by this method were in good agreement with those obtained by other independent method like FAAS.


Subject(s)
Boric Acids , Cesium/chemistry , Chlorides/chemistry , Rubidium/analysis , Deuterium , Indicators and Reagents , Spectrophotometry, Atomic/instrumentation , Spectrophotometry, Atomic/methods , Thermodynamics , Trace Elements/analysis
15.
J Environ Manage ; 79(1): 43-50, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16171934

ABSTRACT

Disposal of water produced with petroleum has been of great interest in Kuwait for the last 20 years. The current problem arose when the Burgan oil field, which is the second largest field in the world, experienced successive increases in the water content of the produced oil. This study introduces a decision-making analysis of the considered alternatives for the disposal of the produced water. Four alternative solutions exist for the industry as practical solutions for the disposal of water produced in Kuwait. The first method utilizes a large number of pits to discharge water. The second alternative depends on discharging water into sealed pits. The third approach to dispose water is by injecting the water underground. The last method is similar to the previous one, but takes into consideration the recovery of reservoir pressure to maintain the rate of oil production. A questionnaire was distributed to 48 experts at the top management level of the petroleum companies and the governmental authority. The data collected considered cost, efficiency, and environmental parameters. Based on the data, a statistical analysis was conducted using the factor analysis method to reduce the number of investigated variables. The analysis concluded that the optimal solution is to use the effluent injection method to discharge water produced with oil in Burgan and similar fields in Kuwait.


Subject(s)
Industrial Waste , Petroleum , Waste Disposal, Fluid/methods , Waste Management , Water Purification/methods , Data Collection , Environmental Monitoring , Kuwait , Waste Management/economics , Waste Management/methods , Waste Management/statistics & numerical data
16.
Talanta ; 70(3): 602-8, 2006 Oct 15.
Article in English | MEDLINE | ID: mdl-18970815

ABSTRACT

The use of boric acid as a modifier for the determination of trace amount of indium in high purity antimony by electrothermal atomic absorption is described. It was found that the negative influence of the hydrofluoric acid, used for the digestion could not be eliminated by using stabilized temperature platform furnace (STPF) alone. Due to the high dissociation energy (D(0)=506kJmol(-1)) of indium fluoride, it is difficult to dissociate in the gas phase and hence is lost. In presence of HF (used for the dissolution of antimony), the universal Pd-Mg modifier does not work satisfactorily. Additionally, rising corrosion and reduced tube lifetime were observed when the acid digested (HF-HNO(3)) antimony solution was injected in to the platform. Improvement in platform life and elimination of interferences were achieved by the addition of boric acid as a chemical modifier together with ruthenium coating of the platform. Corrosive changes of the transversely heated graphite atomizer (THGA) platform surface were examined by scanning electron microscopy. The standard addition method was applied. A characteristic mass of 36pg was obtained. The detection limit of the proposed method is around 0.04mugg(-1). The developed method was applied to the determination of indium in real samples. The data obtained by this method were in good agreement with those obtained by ICP-MS.

17.
J Chromatogr A ; 1074(1-2): 229-33, 2005 May 13.
Article in English | MEDLINE | ID: mdl-15941060

ABSTRACT

A simple dual vessel in situ analyte distillation (IAD) system has been developed for suppressed ion chromatographic determination of chloride and fluoride ions in complex matrices. In IAD system, water vapours generated from the outer vessel reacts with sulfuric acid generating heat, thus favouring the quantitative distillation of chloride and fluoride within 30 min on water bath temperature (approximately 80 degrees C). The distilled analytes, as their respective acids in water, were directly injected into an ion-chromatograph. This newly developed method has been applied for analysis of trace impurities in H2SO4, H3PO4 and H3BO3. The detection limits for chloride is 8, 80 and 70ppb (w/w) for H2SO4, H3PO4 and H3BO3, respectively. For fluoride the detection limits are 6 and 60 ppb (w/w) for H2SO4 and H3PO4, respectively. The recovery of spikes for both the analytes ranged between 87 and 100%.


Subject(s)
Boric Acids/chemistry , Chlorides/analysis , Chromatography, Liquid/methods , Fluorides/analysis , Phosphoric Acids/chemistry , Sulfuric Acids/chemistry , Reproducibility of Results , Volatilization
18.
Analyst ; 130(4): 498-501, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15776159

ABSTRACT

The speciation and determination of sulfate (SO4(2-)) and elemental sulfur (S degree) in zinc sulfide (ZnS) using ion-chromatography (IC) and reversed-phase liquid chromatography (RPLC) respectively is described. Three sample pretreatment approaches were employed with the aim of determining sulfate: (i) conventional water extraction of the analyte; (ii) solid-liquid aqueous extraction with an ultrasonic probe; and (iii) elimination of the zinc sulfide matrix via ion-exchange dissolution (IED). The separation of sulfate was carried out by an anion-exchange column (IonPac AS17), followed by suppressed conductivity detection. Elemental sulfur was extracted ultrasonically from the acid treated sample solution into chloroform and separated on a reversed phase HPLC column equipped with a diode array detector (DAD) at 264 nm. The achievable solid detection limits for sulfate and sulfur were 35 and 10 microg g(-1) respectively.

19.
J Chromatogr A ; 1050(2): 223-7, 2004 Oct 01.
Article in English | MEDLINE | ID: mdl-15508316

ABSTRACT

In situ matrix evaporation of high-purity acids based on isothermal distillation was achieved in a high-density polyethylene (HDPE) container on a water bath, to avoid contamination from the laboratory environment. The solubility of water and acid vapours in glycerol due to co-association was utilized to achieve complete evaporation. All major sources which contribute to the process blank were taken care of in a simple and effective way. A 50-fold preconcentration with >99.9% matrix removal was achieved for the analysis of low-boiling acids, HCl, HF, HNO3 and H2O2. The non-volatile ions NH4+, Li+, Na+, K+, Mg2+, Ca2+, SO4(2-) and PO4(3-) were determined by ion chromatograph with conductivity detection. The detection limits were 6-130 ng/l with recoveries of 85-110% for all ions studied.


Subject(s)
Indicators and Reagents/chemistry , Chromatography, Ion Exchange , Polyethylenes , Reproducibility of Results , Thermodynamics
20.
J Chromatogr A ; 1036(2): 223-7, 2004 May 21.
Article in English | MEDLINE | ID: mdl-15146925

ABSTRACT

Trace levels of phosphorus in purified quartz are determined by ion chromatography. In situ reagent purification, matrix digestion and oxidation of phosphorus to orthophosphate ion are carried out simultaneously in a vapour phase digestion (VPD) assembly using a mixture of HF, HNO3 and H2O2. A drastic reduction (475 times) in phosphate blank from reagents (HF/H2O2) was achieved in the VPD through in situ purification of the reagent. The residues remaining after volatilisation (solvent/matrix), mostly consisting of insoluble phosphate/fluoride salts of divalent and trivalent cations, were solubilised by ion-exchange dissolution. Phosphate was analysed on the IonPac AS17 column with suppressed conductivity detection. The results of the ion chromatography (IC) method were compared with a spectrophotometric method. Accuracy was evaluated by analysing a certified reference material (silicon, NIST 57a). The method detection limit was 0.05 microg g(-1).


Subject(s)
Chromatography, Liquid/methods , Phosphorus/analysis , Quartz/chemistry , Indicators and Reagents , Reference Standards
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