Ocular Manifestations of Venomous Snake Bite over a One-year Period in a Tertiary Care Hospital

Praveen Kumar K V,Praveen Kumar S,Nirupama Kasturi,Shashi Ahuja 대한안과학회 2015 Korean Journal of Ophthalmology Vol.29 No.4

Purpose: Ocular manifestations in snake-bite injuries are quite rare. However, the unusual presentations, diagnosis and their management can pose challenges when they present to the ophthalmologist. Early detection of these treatable conditions can prevent visual loss in these patients who are systemically unstable and are unaware of their ocular condition. To address this, a study was conducted with the aim of identifying the various ocular manifestations of snake bite in a tertiary care center. Methods: This is a one-year institute-based prospective study report of 12 snake bite victims admitted to a tertiary hospital with ocular manifestations between June 2013 to June 2014, which provides data about the demographic characteristics, clinical profiles, ocular manifestations, and their outcomes. Results: Twelve cases of snake bite with ocular manifestations were included of which six were viper bites, three were cobra bites and three were unknown bites. Six patients presented with bilateral acute angle closure glaucoma (50%), two patients had anterior uveitis (16.6%) of which one patient had concomitant optic neuritis. One patient had exudative retinal detachment (8.3%), one patient had thrombocytopenia with subconjunctival hemorrhage (8.3%) and two patients had external ophthalmoplegia (16.6%). Conclusions: Bilateral angle closure glaucoma was the most common ocular manifestation followed by anterior uveitis and external ophthalmoplegia. Snake bite can result in significant ocular morbidity in a majority of patients but spontaneous recovery with anti-snake venom, steroids and conservative management results in good visual prognosis.

Bilateral Acute Anterior Uveitis and Optic Disc Edema Following a Snake Bite

Praveen K Kumar,Shashi Ahuja,Praveen S Kumar 대한안과학회 2014 Korean Journal of Ophthalmology Vol.28 No.2

The authors wish to report a case of bilateral acute anterior uveitis and optic disc edema following ahemotoxic snake bite, in order to highlight the concomitant occurrence of these conditions and the potentialadverse effects of anti-snake venom (ASV). A 35-year-old male was bitten by a viper at seventeen thirtyhours, and was started on ASV. Two days following treatment he experienced sudden onset redness andpainful diminution of vision in both eyes (OU). On examination, the patient’s visual acuity (VA) in OU was 20/ 200. Examination revealed fresh keratic precipitates, cells, and flare in the anterior chamber (AC), posteriorsynechiae, sluggish and ill-sustained pupillary reaction, and hyperemic, edematous disc with blurredmargins in OU. He was started on topical steroids, cycloplegics and intravenous methylprednisolone. Following treatment, the patient showed improvement and was continued on topical medications and oralprednisolone tapered over 3 weeks, after which VA OU improved, the AC showed no cells and flare anddisc edema resolved. Uveitis and optic disc edema in snake bite can either be due to the direct toxic effectsof the venom or the effect of ASV. Steroids have a beneficial role in the management of these symptoms.

Magneto-transport Properties of La_(0.80)Sr_(0.20)Mn_(1−x)Cu_xO_3 Thin Films Fabricated by Using Spray Pyrolysis

Pawan Kumar,Rakesh Kumar Dwivedi,Pawan Kumar,Ravikant Prasad,Praveen Kumar Siwach,Hari Krishna Singh 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.1

Thin films of La_(0.80)Sr_(0.20)Mn_(1−x)Cu_xO_3 with x = 0.00, 0.04, 0.08, 0.10, 0.15, and 0.20 were deposited on single-crystal LaAlO_3 (100) (LAO) substrates at 250 ± 10 ℃ by using a nebulized spray pyrolysis technique. Structural, surface, and transport characterizations were done by X-ray diffraction (XRD), atomic force microscopy (AFM) and the standard four probe technique, respectively. XRD patterns revealed the formation of single-phase polycrystalline films with a rhombohedral crystal structure. Cu substitution resulted in a uniform decrease in the metal insulator transition (T_(IM)) temperature up to x = 0.10, followed by a drastic decrease in T_(IM) for x = 0.15. Finally, the metal-insulator transition vanished for higher Cu concentrations (x = 0.20) in the observed temperature range. The variation in T_(IM) with the amount of added Cu is explained on the basis of the double exchange mechanism. Cu substitution has been found to perturb the Mn^(3+)-O-Mn^(4+) network and has a strong influence on T_(IM). The variation in resistivity maxima with temperature for different Cu concentrations showed a systematic trend up to x ∼ 0.10. We also explored the electrical conduction at T > T_(IM) in the framework of small polaron hopping in the adiabatic limit. The activation energy showed a strong dependence on the Cu concentration. The maximum magneto-resistance (MR) up to 10%, was observed for x = 0.15 at low temperatures.

Squamous Cell Carcinoma in Exstrophy of the Bladder

Pramod Kumar Sharma,Praveen Kumar Pandey,Mukesh Kumar Vijay,Malay Kumar Bera,Jitendra Pratap Singh,Kaushik Saha 대한비뇨의학회 2013 Investigative and Clinical Urology Vol.54 No.8

Exstrophy of the bladder is a rare congenital anomaly with an incidence of about 1 per 50,000 newborns. The malignant potential of the exstrophied bladder mucosa is well known; 95% are adenocarcinomas, and 3% to 5% are squamous cell carcinomas. Most of the malignant tumors (60%) associated with an exstrophy of the bladder occur during the fourth and fifth decades of life. Of the remaining, about 20% each occur after 60 years and before 40 years. Here we present a case in which squamous cell carcinoma developed in an unrepaired exstrophy of the bladder. We present the management of the case and a brief review of the literature.

Synthesis and Catalytic Applications of Ruthenium(0) Nanoparticles in Click Chemistry

Kumar, Avvaru Praveen,Baek, Min-Wook,Sridhar, Chirumarry,Kumar, Begari Prem,Lee, Yong-Ill Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.4

Here we report a facile synthesis of ruthenium (Ru) Nanoparticles (NPs) by chemical co-precipitation method. The calcination of ruthenium hydroxide samples at $500^{\circ}C$ under hydrogen atmosphere lead to the formation of $Ru^0$ NPs. The size and aggregation of Ru NPs depends on the pH of the medium, and type of surfactant and its concentration. The X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope image (TEM) analyses of particles indicated the formation of $Ru^0$ NPs, and have 10 to 20 nm sizes. As-synthesized $Ru^0$ NPs are characterized and investigated their catalytic ability in click chemistry (azidealkyne cycloaddition reactions), showing good results in terms of reactivity. Interestingly, small structural differences in triazines influence the catalytic activity of $Ru^0$ nanocatalysts. Click chemistry has recently emerged to become one of the most powerful tools in drug discovery, chemical biology, proteomics, medical sciences and nanotechnology/nanomedicine. In addition, preliminary tests of recycling showed good results with neither loss of activity or significant precipitation.

Review: Overcoming the paradox of strength and ductility in ultrafine-grained materials at low temperatures

Kumar, Praveen,Kawasaki, Megumi,Langdon, Terence G. Springer-Verlag 2016 JOURNAL OF MATERIALS SCIENCE - Vol.51 No.1

<P>Ultrafine-grained (UFG) materials with grain sizes in the submicrometer or nanometer range may be prepared through the application of severe plastic deformation (SPD) to bulk coarse-grained solids. These materials generally exhibit high strength but only very limited ductility in low-temperature testing, thereby giving rise to the so-called paradox of strength and ductility. This paradox is examined and a new quantitative diagram is presented which permits the easy insertion of experimental data. It is shown that relatively simple procedures are available for achieving both high strength and high ductility in UFG materials including processing the material to a very high strain and/or applying a very short-term anneal immediately after the SPD processing. Significant evidence is now available demonstrating the occurrence of grain boundary sliding in these materials at low temperatures, where this is attributed to the presence of non-equilibrium grain boundaries and the occurrence of enhanced diffusion along these boundaries.</P>

Isomeric discrimination and quantification of thyroid hormones, T₃ and rT₃, by the single ratio kinetic method using electrospray ionization mass spectrometry

Kumar, Avvaru Praveen,Jin, Hua,Jo, Sung-Chan,Kim, Changdae,Nam, Sang-Ho,Lee, Yong-Ill Springer-Verlag 2010 Journal of the American Society for Mass Spectrome Vol.21 No.1

<P>The single ratio kinetic method is applied to the discrimination and quantification of the thyroid hormone isomers, 3,5,3′-triiodothyronine and 3,3′,5′-triiodothyronine, in the gas phase, based on the kinetics of the competitive unimolecular dissociations of singly charged transition-metal ion-bound trimeric complexes [M<SUP>II</SUP>(A)(ref*)<SUB>2</SUB>-H]<SUP>+</SUP> (M<SUP>II</SUP> = divalent transition-metal ion; A=T<SUB>3</SUB> or rT<SUB>3</SUB>; ref* = reference ligand). The trimeric complex ions are generated using electrospray ionization mass spectrometry and the ions undergo collisional activation to realize isomeric discrimination from the branching ratio of the two fragment pathways that form the dimeric complexes [M<SUP>II</SUP>(A)(ref*)-H]<SUP>+</SUP> and [M<SUP>II</SUP>(ref*)<SUB>2</SUB>-H]<SUP>+</SUP>. The ratio of the individual branching ratios for the two isomers R<SUB>iso</SUB> is found strongly dependent on the references and the metal ions. Various sets are tried by choosing the reference from amino acids, substituted amino acids, and dipeptides in combination with the central metal ion chosen from five transition-metal ions (Co<SUP>II</SUP>, Cu<SUP>II</SUP>, Mn<SUP>II</SUP>, Ni<SUP>II</SUP>, and Zn<SUP>II</SUP>) for the complexes in this experiment. The results are compared in terms of the isomeric discrimination for the T<SUB>3</SUB>/rT<SUB>3</SUB> pair. Calibration curves are constructed by relating the ratio of the branching ratios against the isomeric composition of their mixture to allow rapid quantitative isomer analysis of the sample pair. Furthermore, the instrument-dependence of this method is investigated by comparing the two sets of results, one obtained from a quadrupole ion trap mass spectrometer and the other from a quadrupole time-of-flight mass spectrometer.</P>

Tuning Band Alignments and Charge-Transport Properties through MoSe₂ Bridging between MoS₂ and Cadmium Sulfide for Enhanced Hydrogen Production

Kumar, D. Praveen,Kim, Eun Hwa,Park, Hanbit,Chun, So Yeon,Gopannagari, Madhusudana,Bhavani, P.,Reddy, D. Amaranatha,Song, Jae Kyu,Kim, Tae Kyu American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.31

<P>Transition-metal dichalcogenide materials play a major role in the state-of-the-art innovations for energy conversion because of potential applications resulting from their unique properties. These materials additionally show inordinate potential toward the progress of hygienic power sources to deal with increasing environmental disputes at the time of skyrocketing energy demands. Herein, we report earth-abundant, few-layered, MoSe<SUB>2</SUB>-bridged MoS<SUB>2</SUB>/cadmium sulfide (CdS) nanocomposites, which reduce photogenerated electron and hole recombination by effectively separating charge carriers to achieve a high photocatalytic efficiency. Accordingly, the MoSe<SUB>2</SUB>-bridged MoS<SUB>2</SUB>/CdS system produced effective hydrogen (193 μmol·h<SUP>-1</SUP>) as that of water using lactic acid as a hole scavenger with the irradiation of solar light. The presence of few-layered MoSe<SUB>2</SUB> bridges in MoS<SUB>2</SUB>/CdS successfully separates photogenerated charge carriers, thereby enhancing the shuttling of electrons on the surface to active edge sites. To the best of our knowledge, this few-layered MoSe<SUB>2</SUB>-bridged MoS<SUB>2</SUB>/CdS system exhibits the most effective concert among altogether-reported MoS<SUB>2</SUB>-based CdS composites. Notably, these findings with ample prospective for the development of enormously real photocatalytic systems are due to their economically viable and extraordinary efficiency.</P> [FIG OMISSION]</BR>

Noble metal-free metal-organic framework-derived onion slice-type hollow cobalt sulfide nanostructures: Enhanced activity of CdS for improving photocatalytic hydrogen production

Kumar, D. Praveen,Park, Hanbit,Kim, Eun Hwa,Hong, Sangyeob,Gopannagari, Madhusudana,Reddy, D. Amaranatha,Kim, Tae Kyu Elsevier 2018 Applied catalysis. B, Environmental Vol.224 No.-

<P><B>Abstract</B></P> <P>The hollow materials have played a significant role in cutting-edge innovations for energy conversion due to their peculiar properties and their wide range of potential applications. These materials show great promise for the development of cleaner power sources to address growing environmental concerns at a time of increasing global demand for energy. Noble metal-free MOF-derived onion slice-type hollow structured Co<SUB>4</SUB>S<SUB>3</SUB> was developed and embedded with CdS nanoparticles for photocatalytic hydrogen production. The incorporation of Co<SUB>4</SUB>S<SUB>3</SUB> with the CdS particles effectively accelerated charge separation and transfer in photocatalytic reactions due to the low density, hollow interior, and shell permeability of the onion-type composite. The optimized Co<SUB>4</SUB>S<SUB>3</SUB>/CdS photocatalyst led to an enhanced rate of H<SUB>2</SUB> production of 12,360μmolh<SUP>−1</SUP> g<SUP>−1</SUP> under simulated solar light irradiation; this value is 26-fold greater than that of the pristine CdS nanoparticles. The Co<SUB>4</SUB>S<SUB>3</SUB>/CdS composite exhibited remarkably stable photocatalytic performance for up to 65h and could be reused in five successive cycles. Furthermore, to the best of our knowledge, this is the highest H<SUB>2</SUB> production rate achieved with cobalt sulfide-based CdS nanoparticle photocatalysts in the photocatalysis of water under simulated solar light irradiation. Owing to its low cost and high efficiency, this photocatalytic system should hold great potential for the development of highly efficient photocatalytic materials for use in various fields.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Noble metal-free MOF-derived onion slice-type hollow structured Co<SUB>4</SUB>S<SUB>3</SUB> was developed. </LI> <LI> The Co<SUB>4</SUB>S<SUB>3</SUB> with the CdS particles effectively accelerated charge separation. </LI> <LI> The low density, hollow interior, shell permeability of Co<SUB>4</SUB>S<SUB>3</SUB> improves the transfer property. </LI> <LI> The optimized Co<SUB>4</SUB>S<SUB>3</SUB>/CdS shows high rate of H<SUB>2</SUB> production of 12,360μmolh<SUP>−1</SUP> g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Noble metal-free MOF-derived onion slice-type hollow cobalt sulfide nanostructures: Enhanced activity of CdS for improving photocatalytic hydrogen production by D.P. Kumar et al.</P> <P>[DISPLAY OMISSION]</P>

A radial point interpolation method for 1D contaminant transport modelling through landfill liners

Praveen Kumar, R.,Dodagoudar, G.R. Techno-Press 2010 Geomechanics & engineering Vol.2 No.2

In the framework of meshfree methods, a new methodology is developed based on radial point interpolation method (RPIM). This methodology is applied to a one-dimensional contaminant transport modelling in the saturated porous media. The one-dimensional form of advection-dispersion equation involving reactive contaminant is considered in the analysis. The Galerkin weak form of the governing equation is formulated using 1D meshfree shape functions constructed using thin plate spline radial basis functions. MATLAB code is developed to obtain the numerical solution. Numerical examples representing various phenomena, which occur during migration of contaminants, are presented to illustrate the applicability of the proposed method and the results are compared with those obtained from the analytical and finite element solutions. The proposed RPIM has generated results with no oscillations and they are insensitive to Peclet constraints. In order to test the practical applicability and performance of the RPIM, three case studies of contaminant transport through the landfill liners are presented. A good agreement is obtained between the results of the RPIM and the field investigation data.