Publications by authors named "Khopkar S"

Aggregation of monoclonal antibodies (mAbs) is the driving force for their undesirable immunogenic effects. There are multiple factors responsible for aggregation in therapeutic proteins. One significant cause is the process-related shear and interfacial stress generated due to impellers and stirrers.

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We have synthesized a π-conjugated acceptor-donor-acceptor-donor (A-D-A-D) type of unsymmetrical squaraine dye, signified by USQ-1 based on 1-ethyl-2,3,3,8-tetramethyl-2,3-dihydro-1H-pyrrolo[3,2-h] quinoline moiety to improve the absorption as well as emission spectra to the red-emitting region. The influence of pyridine as a subsidiary electron acceptor unit on various properties in USQ-1 dye was compared with their close relative dye (USQ-2). The synthesized dyes were examined by FT-IR, HR-MS, H, and C NMR spectroscopy.

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Two novel acceptor-donor-acceptor-donor-acceptor (A-D-A-D-A) type pi-conjugated symmetrical squaraine dyes, denoted by PQSQ 1 and PQSQ 2 based on 2, 3, 3, 8-tetramethyl -3H-pyrrolo [3,2-h] quinoline were successfully synthesized for the first time to arrive absorption and emission at NIR region. These dyes comprise indolenines as electron donor units, squaryl ring as a central electron acceptor and pyridines as terminal electron acceptor units. The relationship between molecular structures and photophysical properties of these dyes was studied in comparison with their parent compounds (ISQ and N-Et ISQ).

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Distal humeral physeal injury is a rare entity in newborns. Lack of ossific nuclei of the distal humerus in neonates results in a diagnostic dilemma as the injury is radiologically not visible and is often mistaken as elbow dislocation. Ultrasonography and Magnetic resonance imaging help to clinch diagnosis in the early period where plain radiographs fail to detect this entity.

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Background And Aim: The role of dietary patterns in determining age at menarche is insufficiently understood in low-income countries. The relationship between dietary patterns, particularly the consumption of oil, and age at menarche in a slum-dwelling adolescent population in India is examined.

Methods: Data were derived from a cross-sectional baseline survey and anthropometric measurements among 10- to 19-year-old adolescents (n=545, female respondents 272, of whom 160 were post-menarcheal) and a household survey in two slums in the city of Nashik, Western India.

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Water resources are contaminated by life-threatening multidrug resistant pathogenic bacteria. Unfortunately, these pathogenic bacteria do not respond to the traditional water purification methods. Therefore, there is a need of environmentally friendly strategies to overcome the problems associated with the antimicrobial resistant bacterial pathogens.

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Hexaacetatocalix(6)arene was used for the solvent extraction of iron(III). About 7.5x10(-2) M extractant was used at pH 7.

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A novel method is proposed for the solvent extraction of palladium. A superamolecular compound, hexaacetato calix(6)arene in low concentration in toluene quantitatively extracts microgram concentration of palladium at pH 7.5.

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A new method is proposed for the solvent extraction separation of cobalt(II) with hexaacetatocalix(6)arene in toluene. Cobalt(II) was extracted at pH 7.4 with 10 x 10(-4) M hexaacetocalix(6)arene, stripped with 2 M nitric acid, and determined spectrophotometrically at 500 nm as its complex with nitroso-R-salt.

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Cobalt(II) was quantitatively extracted at pH 8.0 with 5 x 10(-3)M Cyanex 272 [Bis(2,4,4 trimethyl pentyl) phosphoric acid] in chloroform. Cobalt(II) was stripped with 0.

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A novel method is proposed for the solvent extraction of niobium(V). A 0.1M solution of Aliquat 336S in xylene quantitatively extracts microgram quantities of niobium(V) from 0.

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A novel method is developed for the reversed-phase extractive chromatographic separation of niobium and tantalum with bis(2-ethylhexyl)phosphoric acid. Niobium is extracted from 1-10M hydrochloric acid and can be stripped with 3M sulphuric acid containing 2% hydrogen peroxide. Tantalum is extracted from 0.

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Tin is extracted from 0.01M hydrochloric acid on a silica-gel column impregnated with bis(2-ethylhexyl)phosphoric acid, stripped with 5M hydrochloric acid, and then determined spectrophotometrically as its Pyrocatechol Violet complex at 555 nm. Tin has been separated from several multicomponent mixtures containing arsenic, antimony, bismuth, lead and copper, and determined in various alloys.

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Antimony can be quantitatively extracted from 1M sulphuric acid containing 0.25M potassium iodide with 0.02M 18-crown-6 in methylene chloride, and determined spectrophotometrically at 430 nm.

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The reversed-phase extraction chromatographic separation of selenium(IV) and tellurium(IV) from several elements with trioctylphosphine oxide as extractant is reported. Selenium was extracted from 6M hydrochloric acid containing 7M lithium chloride was stripped with 4M hydrochloric acid, and tellurium was extracted from either the same medium as selenium or from 4M hydrochloric acid, and stripped with 1-2M hydrochloric acid. Selenium and tellurium can be separated from multicomponent mixtures.

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Germanium(IV) can be separated by reversed-phase extraction chromatography with TBP as stationary phase on a column of silica gel, with 6M hydrochloric acid as the mobile phase, and stripped with various eluents. Germanium can thus be separated (by selective extraction) from those elements which are not extractable with TBP, and (by selective stripping) from elements that are extractable.

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Thorium is quantitatively extracted with 4% Amberlite LA-1 or LA-2 in xylene, from 0.01M malonic acid medium at pH 3.0 and stripped from the organic phase with 1M hydrochloric acid, then determined spectrophotometrically at 545 nm as its complex with thoron.

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Zirconium is quantitatively extracted with 4% Amberlite LA-1 or LA-2 in xylene, from 0.01 M malonic acid medium at pH 3.0 and stripped from the organic phase with 2M hydrochloric acid, then determined spectrophotometrically at 665 nm as its complex with Arsenazo III.

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Scandium is quantitatively extracted with 4% Amberlite LA-1 or Amberlite LA-2 in xylene at pH 2.5-5.5 from 0.

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Iron(III) is separated by reversed-phase extraction chromatography with TBP as the stationary phase on a column of silica gel, with 2-6M hydrochloric acid as the mobile phase. From knowledge of the distribution coefficients, several separations have been devised, such as separation of Fe(III) from alkali and alkaline earth metals, chromium, manganese, cobalt, nickel, copper, vanadium zirconium, thorium, uranium, yttrium and titanium.

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