Sumit Kumar - Academia.edu (original) (raw)

Papers by Sumit Kumar

Journal of Pure and Applied Microbiology

Botanicals obtained from the plants are well known for the suppression of inimical plant pathogen... more Botanicals obtained from the plants are well known for the suppression of inimical plant pathogens. The present study explores the efficacy of five locally available plant extracts for their antifungal activity against the early blight of potato incited by Alternaria solani. The extracts include Datura stramonium, Allium sativum, Azadirachta indica, Eucalyptus globulus, and Lantana camara. All extracts reduced mycelial growth and conidial germination of A. solani. In vitro studies showed that extracts obtained from A. sativum and A. indica have significant inhibition of mycelial growth of A. solani (88.80 and 86.62 percent) at 20 percent concentration. Higher concentrations of A. sativum extract caused a higher reduction of A. solani radial growth on potato dextrose agar medium. Extracts obtained from A. sativum and A. indica at 20 percent concentration, were found most effective for inhibition of conidial germination (85.50 and 80.04 percent) respectively of A. solani. Observations...

Advances in Intelligent Systems and Computing

Journal of Heat Transfer

The present article proposed the closed-form solution of the generalized non-Fourier model-based ... more The present article proposed the closed-form solution of the generalized non-Fourier model-based bio-heat transfer equation (BHTE) in Cylindrical coordinates to understand the thermal behavior of living tissue heated by a pulsed laser. The axisymmetric living tissue exposed to the non-Gaussian temporal profile of laser heating has been considered to investigate the non-Fourier bio-heat transfer phenomena. The closed-form solution of the generalized non-Fourier model-based BHTE with time-dependent thermal energy generation has been obtained through the finite integral transform technique. The analytical solution was juxtaposed to the corresponding numerical solution in order to determine its reliability. The numerical solution of the aforementioned governing equation has been obtained by the finite volume method. The results of both analytical and numerical solutions have been verified using results given in published literature. Subsequently, the dual-phase-lag model's findings ...

Chemosensors

Dissolved oxygen (DO) is an important parameter to monitor in processes applicable in, for exampl... more Dissolved oxygen (DO) is an important parameter to monitor in processes applicable in, for example, water technology and fermentation. In this study, we report the manufacturing of a membrane-less amperometric sensor that is based on the electrocatalytic reduction of oxygen. The sensor was tested in pH-neutral KNO3 solutions and in a microbial fermentation to monitor the consumption of dissolved oxygen. The nitrogen and boron-doped reduced graphene oxide (N,B-HRGO) is used as an electrocatalyst for oxygen reduction. One step co-doping of nitrogen and boron on graphene oxide is performed using the hydrothermal method. The sensor responded linearly to the DO concentration. A sensitivity of 0.2 µA/mg·L−1 O2 is obtained for the DO concentration of 1.5 to 10 mg·L−1 O2. The membrane-less N,B-HRGO based DO sensor is successfully tested in an Amycolotopsis methanolica fermentation by monitoring the dissolved oxygen in real-time. The sensor detected the consumption of oxygen during the growt...

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry

Pd (II), Pt (II), Ru (III), and Ir (III) complexes of general stoichiometry [PdL] Cl2,[PtL] Cl2,[... more Pd (II), Pt (II), Ru (III), and Ir (III) complexes of general stoichiometry [PdL] Cl2,[PtL] Cl2,[Ru (L) Cl2] Cl, and [Ir (L) Cl2] Cl, with tetradentate macrocyclic ligand, derived from 2, 6-diaminopyridine with 3-methyl 2, 4-pentanedione has been synthesized. The ligand was ...

International journal of neural systems, Jan 22, 2018

An important goal in visual neuroscience is to understand how neuronal population coding in verte... more An important goal in visual neuroscience is to understand how neuronal population coding in vertebrate retina mediates the broad range of visual functions. Microelectrode arrays interface on isolated retina registers a collective measure of the spiking dynamics of retinal ganglion cells (RGCs) by probing them simultaneously and in large numbers. The recorded data stream is then processed to identify spike trains of individual RGCs by efficient and scalable spike detection and sorting routines. Most spike sorting software packages, available either commercially or as freeware, combine automated steps with judgment calls by the investigator to verify the quality of sorted spikes. This work focused on sorting spikes of RGCs into clusters using an integrated analytical platform for the data recorded during visual stimulation of wild-type mice retinas with whole field stimuli. After spike train detection, we projected each spike onto two feature spaces: a parametric space and a principal...

Health services research, Feb 26, 2016

To identify factors that promote the effective performance of accountable care organizations (ACO... more To identify factors that promote the effective performance of accountable care organizations (ACOs) in the Medicare Shared Savings Program. Data come from a convenience sample of 16 Medicare Shared Savings ACOs that were organized around large physician groups. We use claims data from the Center for Medicaid and Medicare Services and data from 60 interviews at three high-performing and three low-performing ACOs. Explanatory sequential design, using qualitative data to account for patterns observed in quantitative assessment of ACO performance. A total of 16 ACOs were first rank-ordered on measures of cost and quality of care; we then selected three high and three low performers for site visits; interview data were content-analyzed. Results identify several factors that distinguish high- from low-performing ACOs: (1) collaboration with hospitals; (2) effective physician group practice prior to ACO engagement; (3) trusted, long-standing physician leaders focused on improving performan...

Carbohydrate Polymers, Mar 1, 2010

We present a python package "ScalPy" for studying the late time scalar field cosmology ... more We present a python package "ScalPy" for studying the late time scalar field cosmology for a wide variety of scalar field models, namely the quintessence, tachyon and Galileon model. The package solves the autonomous system of equations for power law and exponential potential. But it can be easily generalized to add more complicated potential. For completeness, we also include the standard parameterization for dark energy models, e.g. the Lambda\LambdaLambdaCDM, wwwCDM, w0waw_{0}w_{a}w0waCDM as well as the GCG parameterization. The package also solves the linear growth equation for matter perturbations on sub-horizon scales. All the important observables related to background universe as well as to the perturbed universe, e.g. luminosity distance ($D_{L}(z)$), angular diameter distance ($D_{A}(z)$), normalized Hubble parameter ($h(z)$), lookback time ($t_{L}$), equation of state for the dark energy ($w(z)$), growth rate ($f=\frac{d \ln\delta}{d \ln a}$), linear matter power spectra ($P(k)...

Punjab – 142001; E-ma il :b a ld i as h i s h @ g ma il .co m ABSTRACT: Experimental methods are ... more Punjab – 142001; E-ma il :b a ld i as h i s h @ g ma il .co m ABSTRACT: Experimental methods are widely used in research as well as in industrial settings, however, sometimes for very difficult purposes. The primary goal in scientific research is usually to show the statistical significance of an effect that a particular factor exerts on the dependent variables of interest. Design of Experiment (DoE) is a series of tests in which purposeful changes are made to the input variables of a system or process and the effects on response variables are measured. This methodology is applicable to both physical processes and computer simulation models. Factorial experimental designs investigate the effects of many different factors by varying them simultaneously instead of changing only one factor at a time. It allows estimation of the sensitivity to each factor and also to the combined effect of two or more factors. Experimental design methods have been successfully applied to several aspects...

Protection of Metals and Physical Chemistry of Surfaces, 2015

The corrosion inhibition effect of 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-meth... more The corrosion inhibition effect of 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-methylazetidin-2-one (BDMA) and 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-methyl-4-phenylazetidin-2-one (BDPA) on N80 steel in 15% hydrochloric acid solution was studied using weight loss measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The surface morphology of the uninhibited and inhibited samples was studied with the help of scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscope (AFM) methods. The corrosion inhibition efficiency of both inhibitors increased with increasing inhibitors concentration and decreased with increasing temperature. The adsorption of both inhibitor molecules on surface of N80 steel obey Langmuir adsorption isotherm. Potentiodynamic polarization measurements indicated that both the studied inhibitors act as mixed type inhibitor. Quantum chemical calculations were carried out using Density Functional Theory (DFT) to correlate the experimental results with the theoretical results.

Journal of Oral Biology and Craniofacial Research, 2011

Treacher Collins syndrome (TCS) is the most common of the human mandibulofacial dysostosis disord... more Treacher Collins syndrome (TCS) is the most common of the human mandibulofacial dysostosis disorders. It is an autosomal-dominant disorder of the craniofacial development occurring between the fifth and the eighth weeks of embryonic development with an incidence of 1/50,000 live births, range between 1-40,000 and 1-70,000. We present here the various clinical, radiographical and other diagnostic findings of the TCS to correlate the clinical assessment with the diagnostic imaging and review the various investigations and management options being carried out to improve their facial deformity.

MRS Proceedings, 2009

Kinetics of formation of intrinsic colloids by tetravelent metal ions, namely, Th(IV), Hf(IV) and... more Kinetics of formation of intrinsic colloids by tetravelent metal ions, namely, Th(IV), Hf(IV) and Pu(IV) have been studied using the dynamic light scattering technique. The milli-molar solutions of Hf(IV) and Th(IV) were prepared at varying pH (2-4) and ionic strength (0-0.01 M) and the samples were subjected to dynamic light scattering measurements at regular intervals for few days. The results showed that the size of intrinsic colloids varies with pH and ionic strength. In the case of Pu(IV) the concentration of aqueous solutions was 4.5×10−5 M.

Computer Communications and Networks, 2013

Cooperative and mesh networks are new architectures for network convergence that solve some recen... more Cooperative and mesh networks are new architectures for network convergence that solve some recent problems such as load balancing, routing, and handover. This chapter is dedicated to recent trends, proposals and architectures for cooperative and mesh networks. In many cases these networks can also be used to save energy, which also makes them energy-efficient networks.

Journal of controlled release : official journal of the Controlled Release Society, Jan 28, 2014

The objective of this study was to formulate nano-amorphous spray-dried powders of itraconazole t... more The objective of this study was to formulate nano-amorphous spray-dried powders of itraconazole to enhance its oral bioavailability. A combination approach of solvent-antisolvent precipitation followed by spray drying was used. DoE studies were utilized to understand the critical processing parameters: antisolvent-to-solvent ratio, drug concentration and stabilizer concentration. Particle size was the critical quality attribute. Spray drying of the nano-precipitated formulation was performed with several auxiliary excipients to obtain nano-sized amorphous powder formulations. PLM, DSC and PXRD were utilized to characterize the spray-dried powders. In vitro dissolution and in vivo bioavailability studies of the nano-amorphous powders were performed. The particle size of the nano-formulations was dependent on the drug concentration. The smallest size precipitates were obtained with low drug concentration. All high molecular weight auxiliary excipients and mannitol containing formulati...

Journal of Oral Biology and Craniofacial Research, 2011

Background: Deep antegonial notch (AN) is seen in congenital and acquired abnormalities of mandib... more Background: Deep antegonial notch (AN) is seen in congenital and acquired abnormalities of mandible like condylar hypoplasia, temporomandibular joint ankylosis (TMA), muscular hypoactivity and brachial arch syndrome. This study was planned with an aim to study the depth of AN in TMA and find its relation with the duration of ankylosis. Materials and Methods: The study comprised 20 cases of unilateral or bilateral TMA, with age range 8-25 years. A comparison between ipsilateral and contralateral AN was done on ortho-pantomograms of these bilateral and unilateral cases with the time period of total duration of ankylosis. Results: Seven cases had right-sided ankylosis, six had left and seven had bilateral TMA where the history of ankylosis ranged from 6 months to 12 years. Spearman's rank correlation indicated a strong correlation between the duration of history of ankylosis and AN on the ipsilateral/contralateral sides. Wilcoxin signed rank test proved the results to be statistically significant. Conclusion: Deep accentuated AN is one of the clinical features of the TMA and has a direct relation to the morphology and growth pattern of mandible.

International Journal of Pharmaceutics, 2011

The effect of stabilizer type (small molecule vs. polymeric) and the amount of micellar solubiliz... more The effect of stabilizer type (small molecule vs. polymeric) and the amount of micellar solubilized drug on Ostwald ripening of nanosuspensions was investigated. Indomethacin nanosuspensions were prepared with small molecule stabilizers (sodium lauryl sulfate (SLS) and Dowfax 2A1 (DF)) and a polymeric stabilizer (hydroxypropyl methyl cellulose (HPMC)). Two different drug:stabilizer ratios were used to evaluate the effect of micellar solubilized drug. The Ostwald ripening potential of nanosuspensions was evaluated by subjecting them to various stress conditions (temperature (15, 25, 35 and 45 • C), thermal cycling, and mechanical shaking) for three months. The mean particle size increased in all SLS and DF formulations stored under different stress conditions. No effect of micellar solubilized drug on the Ostwald ripening rate was observed. In the case of HPMC formulations only those stored at higher temperatures (35 or 45 • C) exhibited an increase in mean particle size. The increase in size in the HPMC formulation stored at 45 • C was attributed to dehydration of the HPMC chains and subsequent loss of protection of the nanoparticles. The cube of the mean particle diameter versus time plot was determined to be non-linear for all formulations exhibiting Ostwald ripening. Therefore, according to the Lifshitz, Slyozov and Wagner theory the process was not diffusion controlled. The most probable mechanism for Ostwald ripening was surface nucleation controlled.

ECS Transactions, 2006

A low temperature atomic layer deposition (ALD) nanolaminate process was developed for the growth... more A low temperature atomic layer deposition (ALD) nanolaminate process was developed for the growth of Ru-TaN thin films with a controllable Ru: Ta elemental ratio. XPS analyses of the deposited films suggest the presence of Ru-Ta bonding along with the formation of ...

Journal of Pure and Applied Microbiology

Botanicals obtained from the plants are well known for the suppression of inimical plant pathogen... more Botanicals obtained from the plants are well known for the suppression of inimical plant pathogens. The present study explores the efficacy of five locally available plant extracts for their antifungal activity against the early blight of potato incited by Alternaria solani. The extracts include Datura stramonium, Allium sativum, Azadirachta indica, Eucalyptus globulus, and Lantana camara. All extracts reduced mycelial growth and conidial germination of A. solani. In vitro studies showed that extracts obtained from A. sativum and A. indica have significant inhibition of mycelial growth of A. solani (88.80 and 86.62 percent) at 20 percent concentration. Higher concentrations of A. sativum extract caused a higher reduction of A. solani radial growth on potato dextrose agar medium. Extracts obtained from A. sativum and A. indica at 20 percent concentration, were found most effective for inhibition of conidial germination (85.50 and 80.04 percent) respectively of A. solani. Observations...

Advances in Intelligent Systems and Computing

Journal of Heat Transfer

The present article proposed the closed-form solution of the generalized non-Fourier model-based ... more The present article proposed the closed-form solution of the generalized non-Fourier model-based bio-heat transfer equation (BHTE) in Cylindrical coordinates to understand the thermal behavior of living tissue heated by a pulsed laser. The axisymmetric living tissue exposed to the non-Gaussian temporal profile of laser heating has been considered to investigate the non-Fourier bio-heat transfer phenomena. The closed-form solution of the generalized non-Fourier model-based BHTE with time-dependent thermal energy generation has been obtained through the finite integral transform technique. The analytical solution was juxtaposed to the corresponding numerical solution in order to determine its reliability. The numerical solution of the aforementioned governing equation has been obtained by the finite volume method. The results of both analytical and numerical solutions have been verified using results given in published literature. Subsequently, the dual-phase-lag model's findings ...

Chemosensors

Dissolved oxygen (DO) is an important parameter to monitor in processes applicable in, for exampl... more Dissolved oxygen (DO) is an important parameter to monitor in processes applicable in, for example, water technology and fermentation. In this study, we report the manufacturing of a membrane-less amperometric sensor that is based on the electrocatalytic reduction of oxygen. The sensor was tested in pH-neutral KNO3 solutions and in a microbial fermentation to monitor the consumption of dissolved oxygen. The nitrogen and boron-doped reduced graphene oxide (N,B-HRGO) is used as an electrocatalyst for oxygen reduction. One step co-doping of nitrogen and boron on graphene oxide is performed using the hydrothermal method. The sensor responded linearly to the DO concentration. A sensitivity of 0.2 µA/mg·L−1 O2 is obtained for the DO concentration of 1.5 to 10 mg·L−1 O2. The membrane-less N,B-HRGO based DO sensor is successfully tested in an Amycolotopsis methanolica fermentation by monitoring the dissolved oxygen in real-time. The sensor detected the consumption of oxygen during the growt...

Synthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistry

Pd (II), Pt (II), Ru (III), and Ir (III) complexes of general stoichiometry [PdL] Cl2,[PtL] Cl2,[... more Pd (II), Pt (II), Ru (III), and Ir (III) complexes of general stoichiometry [PdL] Cl2,[PtL] Cl2,[Ru (L) Cl2] Cl, and [Ir (L) Cl2] Cl, with tetradentate macrocyclic ligand, derived from 2, 6-diaminopyridine with 3-methyl 2, 4-pentanedione has been synthesized. The ligand was ...

International journal of neural systems, Jan 22, 2018

An important goal in visual neuroscience is to understand how neuronal population coding in verte... more An important goal in visual neuroscience is to understand how neuronal population coding in vertebrate retina mediates the broad range of visual functions. Microelectrode arrays interface on isolated retina registers a collective measure of the spiking dynamics of retinal ganglion cells (RGCs) by probing them simultaneously and in large numbers. The recorded data stream is then processed to identify spike trains of individual RGCs by efficient and scalable spike detection and sorting routines. Most spike sorting software packages, available either commercially or as freeware, combine automated steps with judgment calls by the investigator to verify the quality of sorted spikes. This work focused on sorting spikes of RGCs into clusters using an integrated analytical platform for the data recorded during visual stimulation of wild-type mice retinas with whole field stimuli. After spike train detection, we projected each spike onto two feature spaces: a parametric space and a principal...

Health services research, Feb 26, 2016

To identify factors that promote the effective performance of accountable care organizations (ACO... more To identify factors that promote the effective performance of accountable care organizations (ACOs) in the Medicare Shared Savings Program. Data come from a convenience sample of 16 Medicare Shared Savings ACOs that were organized around large physician groups. We use claims data from the Center for Medicaid and Medicare Services and data from 60 interviews at three high-performing and three low-performing ACOs. Explanatory sequential design, using qualitative data to account for patterns observed in quantitative assessment of ACO performance. A total of 16 ACOs were first rank-ordered on measures of cost and quality of care; we then selected three high and three low performers for site visits; interview data were content-analyzed. Results identify several factors that distinguish high- from low-performing ACOs: (1) collaboration with hospitals; (2) effective physician group practice prior to ACO engagement; (3) trusted, long-standing physician leaders focused on improving performan...

Carbohydrate Polymers, Mar 1, 2010

We present a python package "ScalPy" for studying the late time scalar field cosmology ... more We present a python package "ScalPy" for studying the late time scalar field cosmology for a wide variety of scalar field models, namely the quintessence, tachyon and Galileon model. The package solves the autonomous system of equations for power law and exponential potential. But it can be easily generalized to add more complicated potential. For completeness, we also include the standard parameterization for dark energy models, e.g. the Lambda\LambdaLambdaCDM, wwwCDM, w0waw_{0}w_{a}w0waCDM as well as the GCG parameterization. The package also solves the linear growth equation for matter perturbations on sub-horizon scales. All the important observables related to background universe as well as to the perturbed universe, e.g. luminosity distance ($D_{L}(z)$), angular diameter distance ($D_{A}(z)$), normalized Hubble parameter ($h(z)$), lookback time ($t_{L}$), equation of state for the dark energy ($w(z)$), growth rate ($f=\frac{d \ln\delta}{d \ln a}$), linear matter power spectra ($P(k)...

Punjab – 142001; E-ma il :b a ld i as h i s h @ g ma il .co m ABSTRACT: Experimental methods are ... more Punjab – 142001; E-ma il :b a ld i as h i s h @ g ma il .co m ABSTRACT: Experimental methods are widely used in research as well as in industrial settings, however, sometimes for very difficult purposes. The primary goal in scientific research is usually to show the statistical significance of an effect that a particular factor exerts on the dependent variables of interest. Design of Experiment (DoE) is a series of tests in which purposeful changes are made to the input variables of a system or process and the effects on response variables are measured. This methodology is applicable to both physical processes and computer simulation models. Factorial experimental designs investigate the effects of many different factors by varying them simultaneously instead of changing only one factor at a time. It allows estimation of the sensitivity to each factor and also to the combined effect of two or more factors. Experimental design methods have been successfully applied to several aspects...

Protection of Metals and Physical Chemistry of Surfaces, 2015

The corrosion inhibition effect of 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-meth... more The corrosion inhibition effect of 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-methylazetidin-2-one (BDMA) and 1-(benzo[d]thiazol-2-yl)-4-(3,5-dibromophenyl)-3-chloro-4-methyl-4-phenylazetidin-2-one (BDPA) on N80 steel in 15% hydrochloric acid solution was studied using weight loss measurement, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The surface morphology of the uninhibited and inhibited samples was studied with the help of scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and atomic force microscope (AFM) methods. The corrosion inhibition efficiency of both inhibitors increased with increasing inhibitors concentration and decreased with increasing temperature. The adsorption of both inhibitor molecules on surface of N80 steel obey Langmuir adsorption isotherm. Potentiodynamic polarization measurements indicated that both the studied inhibitors act as mixed type inhibitor. Quantum chemical calculations were carried out using Density Functional Theory (DFT) to correlate the experimental results with the theoretical results.

Journal of Oral Biology and Craniofacial Research, 2011

Treacher Collins syndrome (TCS) is the most common of the human mandibulofacial dysostosis disord... more Treacher Collins syndrome (TCS) is the most common of the human mandibulofacial dysostosis disorders. It is an autosomal-dominant disorder of the craniofacial development occurring between the fifth and the eighth weeks of embryonic development with an incidence of 1/50,000 live births, range between 1-40,000 and 1-70,000. We present here the various clinical, radiographical and other diagnostic findings of the TCS to correlate the clinical assessment with the diagnostic imaging and review the various investigations and management options being carried out to improve their facial deformity.

MRS Proceedings, 2009

Kinetics of formation of intrinsic colloids by tetravelent metal ions, namely, Th(IV), Hf(IV) and... more Kinetics of formation of intrinsic colloids by tetravelent metal ions, namely, Th(IV), Hf(IV) and Pu(IV) have been studied using the dynamic light scattering technique. The milli-molar solutions of Hf(IV) and Th(IV) were prepared at varying pH (2-4) and ionic strength (0-0.01 M) and the samples were subjected to dynamic light scattering measurements at regular intervals for few days. The results showed that the size of intrinsic colloids varies with pH and ionic strength. In the case of Pu(IV) the concentration of aqueous solutions was 4.5×10−5 M.

Computer Communications and Networks, 2013

Cooperative and mesh networks are new architectures for network convergence that solve some recen... more Cooperative and mesh networks are new architectures for network convergence that solve some recent problems such as load balancing, routing, and handover. This chapter is dedicated to recent trends, proposals and architectures for cooperative and mesh networks. In many cases these networks can also be used to save energy, which also makes them energy-efficient networks.

Journal of controlled release : official journal of the Controlled Release Society, Jan 28, 2014

The objective of this study was to formulate nano-amorphous spray-dried powders of itraconazole t... more The objective of this study was to formulate nano-amorphous spray-dried powders of itraconazole to enhance its oral bioavailability. A combination approach of solvent-antisolvent precipitation followed by spray drying was used. DoE studies were utilized to understand the critical processing parameters: antisolvent-to-solvent ratio, drug concentration and stabilizer concentration. Particle size was the critical quality attribute. Spray drying of the nano-precipitated formulation was performed with several auxiliary excipients to obtain nano-sized amorphous powder formulations. PLM, DSC and PXRD were utilized to characterize the spray-dried powders. In vitro dissolution and in vivo bioavailability studies of the nano-amorphous powders were performed. The particle size of the nano-formulations was dependent on the drug concentration. The smallest size precipitates were obtained with low drug concentration. All high molecular weight auxiliary excipients and mannitol containing formulati...

Journal of Oral Biology and Craniofacial Research, 2011

Background: Deep antegonial notch (AN) is seen in congenital and acquired abnormalities of mandib... more Background: Deep antegonial notch (AN) is seen in congenital and acquired abnormalities of mandible like condylar hypoplasia, temporomandibular joint ankylosis (TMA), muscular hypoactivity and brachial arch syndrome. This study was planned with an aim to study the depth of AN in TMA and find its relation with the duration of ankylosis. Materials and Methods: The study comprised 20 cases of unilateral or bilateral TMA, with age range 8-25 years. A comparison between ipsilateral and contralateral AN was done on ortho-pantomograms of these bilateral and unilateral cases with the time period of total duration of ankylosis. Results: Seven cases had right-sided ankylosis, six had left and seven had bilateral TMA where the history of ankylosis ranged from 6 months to 12 years. Spearman's rank correlation indicated a strong correlation between the duration of history of ankylosis and AN on the ipsilateral/contralateral sides. Wilcoxin signed rank test proved the results to be statistically significant. Conclusion: Deep accentuated AN is one of the clinical features of the TMA and has a direct relation to the morphology and growth pattern of mandible.

International Journal of Pharmaceutics, 2011

The effect of stabilizer type (small molecule vs. polymeric) and the amount of micellar solubiliz... more The effect of stabilizer type (small molecule vs. polymeric) and the amount of micellar solubilized drug on Ostwald ripening of nanosuspensions was investigated. Indomethacin nanosuspensions were prepared with small molecule stabilizers (sodium lauryl sulfate (SLS) and Dowfax 2A1 (DF)) and a polymeric stabilizer (hydroxypropyl methyl cellulose (HPMC)). Two different drug:stabilizer ratios were used to evaluate the effect of micellar solubilized drug. The Ostwald ripening potential of nanosuspensions was evaluated by subjecting them to various stress conditions (temperature (15, 25, 35 and 45 • C), thermal cycling, and mechanical shaking) for three months. The mean particle size increased in all SLS and DF formulations stored under different stress conditions. No effect of micellar solubilized drug on the Ostwald ripening rate was observed. In the case of HPMC formulations only those stored at higher temperatures (35 or 45 • C) exhibited an increase in mean particle size. The increase in size in the HPMC formulation stored at 45 • C was attributed to dehydration of the HPMC chains and subsequent loss of protection of the nanoparticles. The cube of the mean particle diameter versus time plot was determined to be non-linear for all formulations exhibiting Ostwald ripening. Therefore, according to the Lifshitz, Slyozov and Wagner theory the process was not diffusion controlled. The most probable mechanism for Ostwald ripening was surface nucleation controlled.

ECS Transactions, 2006

A low temperature atomic layer deposition (ALD) nanolaminate process was developed for the growth... more A low temperature atomic layer deposition (ALD) nanolaminate process was developed for the growth of Ru-TaN thin films with a controllable Ru: Ta elemental ratio. XPS analyses of the deposited films suggest the presence of Ru-Ta bonding along with the formation of ...