Showing papers by "Government College published in 2008"
TL;DR: The chemical modification affords a wide range of derivatives with modified properties for specific end use applications in diversified areas mainly of pharmaceutical, biomedical and biotechnological fields.
Abstract: Of late, the most bountiful natural biopolymer chitin and chitosan have become cynosure of all party because of an unusual combination of biological activities plus mechanical and physical properties. However applications of chitin are limited due to its inherent insoluble and intractable nature. Chitosan, alkaline hydrolytic derivative of chitin has better solubility profile, less crystallinity and is amenable to chemical modifications due to presence of functional groups as hydroxyl, acetamido, and amine. The chemical modification of chitosan is of interest because the modification would not change the fundamental skeleton of chitosan, would keep the original physicochemical and biochemical properties and finally would bring new or improved properties. In view of rapidly growing interest in chitosan its chemical aspects and chemical modification studies is reviewed. The several chemical modifications such as oligomerization, alkylation, acylation, quternization, hydroxyalkylation, carboxyalkylation, thiolation, sulfation, phosphorylation, enzymatic modifications and graft copolymerization along with many assorted modifications have been carried out. The chemical modification affords a wide range of derivatives with modified properties for specific end use applications in diversified areas mainly of pharmaceutical, biomedical and biotechnological fields. Assorted modifications including chitosan hybrids with sugars, cyclodextrin, dendrimers, and crown ethers have also emerged as interesting multifunctional macromolecules. The versatility in possible modifications and applications of chitosan derivatives presents a great challenge to scientific community and to industry. The successful acceptance of this challenge will change the role of chitosan from being a molecule in waiting to a lead player.
898 citations
TL;DR: In this article, the lattice strain contribution to the X-ray diffraction line broadening in nanocrystalline silver samples with an average crystallite size of about 50 nm was studied using Williamson-Hall analysis.
Abstract: The lattice strain contribution to the X-ray diffraction line broadening in nanocrystalline silver samples with an average crystallite size of about 50 nm is studied using Williamson-Hall analysis assuming uniform deformation, uniform deformation stress and uniform deformation energy density models. It is observed that the anisotropy of the crystallite should be taken into account, while separating the strain and particle size contributions to line broadening. Uniform deformation energy density model is found to model the lattice strain appropriately. The lattice strain estimated from the interplanar spacing data are compared with that estimated using uniform-energy density model. The lattice strain in nanocrystalline silver seems to have contributions from dislocations over and above the contribution from excess volume of grain boundaries associated with vacancies and vacancy clusters.
258 citations
TL;DR: In this paper, the propagation of small but finite amplitude ion acoustic solitons and double layers was investigated in electron-positron-ion plasmas in presence of highly negatively charged impurities or dust.
Abstract: Propagation of small but finite amplitude ion acoustic solitons and double layers are investigated in electron–positron–ion plasmas in presence of highly negatively charged impurities or dust. The presence of negatively charged dust particulates can result in existence of two critical concentrations of ion–electron density ratio α. One of them α
D
decides the existence of double layers, whereas the other one α
R
decides the nature of the solitons and double layers. The system supports both compressive and rarefactive solitons as well as double layers. The parameter regimes of transitions from compressive to rarefactive solitons and double layers are also specified.
148 citations
TL;DR: The results of the present study suggest that a methanolic extract of M. alba leaves may possess an anxiolytic effect.
Abstract: Objective: The aim of the present work is to evaluate the anxiolytic effect of a methanolic extract of Morus alba L. leaves in mice. Materials and Methods: The hole-board test, elevated plus-maze paradigm, open field test, and light/dark paradigm were used to assess the anxiolytic activity of the methanolic extract of M. alba L. Morus alba extract (50, 100, and 200 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.) were administered 30 min before the tests. Results: The results showed that the methanolic extract of M. alba significantly increased the number and duration of head poking in the hole-board test. In the elevated plus-maze, the extract significantly increased the exploration of the open arm in similar way to that of diazepam. At a dose of 200 mg/kg i.p. the extract significantly increased both the time spent in and the entries into the open arm by mice. Further, in the open field test, the extract significantly increased rearing, assisted rearing, and number of squares traversed, all of which are demonstrations of exploratory behavior. In the light/dark paradigm, the extract produced significant increase in time spent in the lighted box as compared to vehicle. The spontaneous locomotor activity count, measured using an actophotometer, was significantly decreased in animals pretreated with M. alba extract, indicating a remarkable sedative effect of the plant. Conclusion: The results of the present study suggest that a methanolic extract of M. alba leaves may possess an anxiolytic effect.
129 citations
TL;DR: Metal complexes of o-vanillidene-2-aminobenzothiazole have been prepared and characterized by elemental and spectral data as well as magnetic susceptibility measurements and thermo gravimetric analysis (TG/DTA), revealing the non-electrolytic nature of these complexes.
116 citations
TL;DR: HPbetaCD had superior antimicrobial activity than that of betaCD while betaCD had greater effect on solubility enhancement of CEF, which was increased significantly by betaCD and HPbetaCD inclusion complexation against S. aureus and E. coli.
97 citations
TL;DR: There was significant reversal of biochemical, histological and functional changes induced by rifampicin treatment in rats by petroleum ether extract treatment, indicating promising hepatoprotective activity.
Abstract: Shade dried leaves of Ficus carica were extracted using petroleum ether (60-80°) and tested for antihepatotoxic activity on rats treated with 50 mg/kg of rifampicin orally. The parameters assessed were serum levels of glutamic oxaloacetate transaminase, glutamic pyruvic transaminase, bilirubin and histological changes in liver. Liver weights and pentobarbitione sleeping time as a functional parameter were also monitored. There was significant reversal of biochemical, histological and functional changes induced by rifampicin treatment in rats by petroleum ether extract treatment, indicating promising hepatoprotective activity.
84 citations
TL;DR: Domperidone microspheres for intranasal administration were prepared by emulsification crosslinking technique using epichlorhydrine as cross-linking agent and showed good mucoadhesive property and swelling behaviour.
Abstract: Domperidone microspheres for intranasal administration were prepared by emulsification crosslinking technique. Starch a biodegradable polymer was used in preparation of microspheres using epichlorhydrine as cross-linking agent. The formulation variables were drug concentration and polymer concentration and batch of drug free microsphere was prepared for comparisons. All the formulations were evaluated for particle size, morphological characteristics, percentage drug encapsulation, equilibrium swelling degree, percentage mucoadhesion, bioadhesive strength, and in vitro diffusion study using nasal cell. Spherical microspheres were obtained in all batches with mean diameter in the range of above 22.8 to 102.63 μm. They showed good mucoadhesive property and swelling behaviour. The in vitro release was found in the range of 73.11% to 86.21%. Concentration of both polymer and drug affect in vitro release of drug.
62 citations
TL;DR: Reflection from insulated and isothermal stress-free surface of a thermoelastic solid half-space under hydrostatic initial stress is studied and the reflection coefficients as well as energy ratios of reflected waves are obtained.
61 citations
TL;DR: The studies indicate that Euphorbia hirta is a potential anxiolytic drug, which might be beneficial in the treatment of stress-induced anxiety disorders.
Abstract: Chronic stress is known to result in impairment of learning and memory and precipitate several affective disorders including depression and anxiety. Drugs of natural origin are known to possess several effects on the central nervous system and are emerging as promising alternative therapies. In this context, the hydroalcoholic extract of Euphorbia hirta (Eh) was evaluated for anxiolytic property in chronically stressed rats subjected to elevated plus maze (EPM) and open field test (OFT). Eh treatment (200 mg/kg, p.o.; seven days) showed marked anti-anxiety activity in chronic immobilization stress. In contrast, the forced swim stress-induced anxiety was only partially decreased by Eh. Co-treatment of rats with flumazenil (0.5 mg/kg, i.p.), bicuculline (1 mg/kg, i.p.) or picrotoxin (1 mg/kg, i.p.) resulted in a significant reduction of anxiolytic effect of Eh indicating that its actions are mediated through GABAA receptor-benzodiazepine receptor-Cl− channel complex. Thus, our studies indicate that Eh is a potential anxiolytic drug, which might be beneficial in the treatment of stress-induced anxiety disorders.
53 citations
TL;DR: In this paper, the pseudodynamic method is used to compute rotational displacements of the retaining wall supporting cohesionless backfill under seismic loading, considering time, phase difference, and effect of amplification in shear and primary waves propagating through the backfill and the wall.
Abstract: Prediction of the rotational displacements, induced by earthquake is a key aspect of the seismic design of retaining walls. In this paper, the pseudodynamic method is used to compute rotational displacements of the retaining wall supporting cohesionless backfill under seismic loading. The proposed method considers time, phase difference, and effect of amplification in shear and primary waves propagating through the backfill and the retaining wall. The influence of ground motion characteristics on rotational displacement of the wall is evaluated. Also the effects of variation of parameters like wall friction angle, soil friction angle, amplification factor, shear wave velocity, primary wave velocity, period of lateral shaking, horizontal, and vertical seismic accelerations on the rotational displacements are studied. Results are provided in graphical form with a comparison to the available pseudostatic result to validate the proposed theory. Present results give higher values of rotational displacements of...
TL;DR: Television and advertising together present a lethal combination and has become an integral part of modern society as mentioned in this paper.It is the most convenient route to reach not only adult consumers but also the ad...
Abstract: Television and advertising together present a lethal combination and has become an integral part of modern society .It is the most convenient route to reach not only adult consumers but also the ad...
TL;DR: In this paper, the molecular geometry and vibrational frequencies of indole and 5-aminoindole in the ground state have been calculated by using the Hartree-Fock and density functional method with 6-311++G(d,p) basis set.
Abstract: The molecular geometry and vibrational frequencies of indole and 5-aminoindole in the ground state have been calculated by using the Hartree–Fock and density functional method with 6-311++G(d,p) basis set. The optimized geometrical parameters obtained by DFT calculations are in good agreement with the experimental values. Comparison of the observed fundamental vibrational frequencies of indole and 5-aminoindole with the calculated results by density functional and Hartree–Fock methods indicates that B3LYP is superior to the scaled Hartree–Fock approach for molecular vibrational problems. The theoretical spectrograms for FT-IR spectrum of 5-aminoindole have been constructed.
TL;DR: A close morphological and phylogenetic relationship was found for A. abijatae and Anabaenopsis (Cyanospira) rippkae and the morphological differences and the low similarity values found between the two clusters indicate two separate genera.
Abstract: Anabaenopsis spp. are heterocytous cyanobacteria commonly found in tropical, subtropical, and temperate water bodies. So far, the knowledge about the phylogeny of this genus is poor. Therefore, we have isolated 15 Anabaenopsis spp. strains from Kenyan and Mexican alkaline and saline water bodies and from a Ugandan freshwater body and studied the morphology and phylogeny in a polyphasic approach. Morphologically, the investigated strains could be discriminated in two groups. One group was containing six Anabaenopsis abijatae and A. cf. abijatae strains with up to more than 500 vegetative cells in one filament, mostly single intercalary heterocyte formation, and the ability to branch out. The other group comprised nine strains of Anabaenopsis elenkinii with short filaments with up to 38 vegetative cells, intercalary heterocytes in pairs, and no ability to branch out. The morphological differences were reflected in the two distinct clusters, which were found in the phylogenetic trees of 16S rDNA and PC-IGS. While the high 16S rDNA similarity values >97.5% found between all investigated A. abijatae and A. elenkinii strains support the assignment of these two species to one single genus, the morphological differences and the low similarity values (<87.3) found in PC-IGS sequences between the two clusters indicate two separate genera. A close morphological and phylogenetic relationship was found for A. abijatae and Anabaenopsis (Cyanospira) rippkae.
TL;DR: In this article, a deformed Korteweg-de Vries (dKdV) equation is derived by using the reductive perturbation method and its numerical solutions are also presented.
TL;DR: In this article, the Lax pair for the one-dimensional Gross-Pitaevskii equation with time-dependent scattering length in the presence of a confining or expulsive harmonic timedependent trap was generated.
Abstract: In this paper, we generate the Lax pair for the one-dimensional Gross-Pitaevskii equation with time-dependent scattering length in the presence of a confining or expulsive harmonic time-dependent trap. We then exploit the Lax pair profitably to construct multisoliton solutions using gauge transformation from a trivial input solution. In particular, we have investigated the effect of both expulsive and confining traps on soliton interaction. Even though we find that the amplitude of the bright soliton relies upon the time-dependent scattering length and the external time-dependent trap with the velocity being dictated by the external trap alone, the observation of interdependence of the scattering length on the trap shows that the bright solitons not only can be compressed into a desirable width and amplitude but also can be remote controlled and driven anywhere in the plane by suitably maneuvering the external time-dependent trap alone.
TL;DR: The results suggest that the methanolic extract of Morus alba L. leaves possesses antidopaminergic activity and can help to establish the plant as an antipsychotic agent.
Abstract: Objective: To evaluate the effect of methanolic extract of Morus alba L leaves on dopaminergic function Materials and Methods: The effect of the methanolic extract of Morus alba L leaves was evaluated on haloperidol and metoclopramide induced catalepsy, foot shock-induced aggression, amphetamine-induced stereotyped behavior and phenobarbitone induced sleeping in mice In each of these tests, the extract was administered in doses of 50, 100 and 200 mg/kg, ip, 30 min before performing the test in mice Further, the inhibitory effect of the extract on dopamine was studied using isolated rat vas deferens Results: The extract produced significant dose dependent potentiation of haloperidol (1 mg/kg, ip) and metoclopramide (20 mg/kg, ip) induced catalepsy in mice The extract significantly reduced number of fights and increased latency to fights in foot shock-induced aggression; it also decreased amphetamine (1 mg/kg, ip) induced stereotyped behavior in a dose dependent manner The sleeping time induced by phenobarbitone (50 mg/kg, ip) too was prolonged The extract inhibited contractions produced by dopamine on isolated rat vas deferens Conclusion: The results suggest that the methanolic extract of Morus alba L possesses antidopaminergic activity Further neurochemical investigation can explore the mechanism of action of the plant drug with respect to antidopaminergic functions and help to establish the plant as an antipsychotic agent
TL;DR: In this article, sufficient conditions involving the Schwarzian derivative of a normalized analytic function are obtained so that either or is convex in the unit disk of the function, and sufficient conditions relating the Schwarzians derivative to the starlikeness or convexity of the functions are determined.
Abstract: Let the functions be analytic and let be analytic univalent in the unit disk. Using the methods of differential subordination and superordination, sufficient conditions involving the Schwarzian derivative of a normalized analytic function are obtained so that either or . As applications, sufficient conditions are determined relating the Schwarzian derivative to the starlikeness or convexity of .
TL;DR: In this article, a pseudo-dynamic approach is used to compute the seismic earth pressure on a rigid retaining wall by considering the effects of time, phase difference in shear and primary waves and soil amplification along with the horizontal and vertical seismic accelerations and other soil properties.
Abstract: To design a retaining wall, conventional Mononobe–Okabe method, which is based on the pseudo-static approach and gives the linear distribution of seismic earth pressures in an approximate way, is used to compute the seismic earth pressures. In this paper, pseudo-dynamic approach is used to compute the seismic earth pressures on a rigid retaining wall by considering the effects of time, phase difference in shear and primary waves and soil amplification along with the horizontal and vertical seismic accelerations and other soil properties. Design value of the seismic active earth pressure coefficient is found to increase with increase in the seismic accelerations, phase difference in body waves and soil amplification, whereas the reverse trend is observed for the passive case. Influence of various soil parameters on seismic passive earth pressure is more significant than that for the active case under harmonic seismic loading. Results are provided in the combined tabular and graphical non-dimensional form for both the seismic active and passive earth pressures. Present results are compared with the available results in literature to validate the proposed non-linearity of seismic earth pressure distribution.
TL;DR: The theoretically constructed spectra coincide satisfactorily with those of experimental spectra and the possible hydrogen bond interaction has been estimated taking a model compound.
TL;DR: In this article, the tensile strength of plain woven fabrics has been predicted by using two empirical modelling methods namely artificial neural network (ANN) and linear regression, which were able to predict the fabric strength with reasonably good precision although ANN model demonstrated higher prediction accuracy and generalization ability than the regression model.
Abstract: Aesthetic properties of fabrics have been considered as the most important fabric attribute for years. However, recently there has been a paradigm shift in the domain of textile material applications and consequently more emphasis is now being given on the mechanical and functional properties of fabrics rather than its aesthetic appeal. Moreover, in certain woven fabrics used for technical applications, strength is a decisive quality parameter. In this work, tensile strength of plain woven fabrics has been predicted by using two empirical modelling methods namely artificial neural network (ANN) and linear regression. Warp yarn strength, warp yarn elongation, ends per inch (EPI), picks per inch (PPI) and weft count (Ne) were used as input parameters. Both the models were able to predict the fabric strength with reasonably good precision although ANN model demonstrated higher prediction accuracy and generalization ability than the regression model. The warp yarn strength and EPI were found to be the two most significant factors influencing fabric strength in warp direction.
TL;DR: In this article, the radon diffusion coefficients and diffusion lengths through some building construction materials have been calculated using LR-115 type II solid-state nuclear track detectors (SSNTDs).
TL;DR: Increasing the solubility of zaleplon has been addressed via solid dispersion technique with various hydrophilic polymers to improve the oral bioavailability of such drugs, which further improves the therapeutic efficacy and patient compliance.
Abstract: Zaleplon (Fig. 1) is a pyrrazolopyrimidine hypnotic drug indicated for the short term (2 to 4 weeks) management of insomnia (1). It interacts with GABAA receptor and also shows some pharmacological properties of benzodiazepines (2). It also possesses potent anticonvulsant activity against pentylenetetrazole- and electroshock-induced convulsions (3) and is rapidly and completely absorbed after oral administration. However, it undergoes extensive first pass hepatic metabolism after absorption, with only 30% of zaleplon being systemically available (4). Zaleplon attains peak concentration (Cmax) within 1.1 h (tmax) approximately after administration, with terminal elimination half life of 1 hour (5). Cmax and area under the plasma concentration–time curve (AUC) both exhibit linear dose proportionality at doses up to 60 mg well above the 10 mg therapeutic dose (6,7).
Fig. 1
Chemical structure of zaleplon
Although zaleplon is rapidly absorbed after oral administration, its poor aqueous solubility (8) (practically insoluble) can make its absorption dissolution rate limited and thus delay onset of action. The dissolution of drugs is a prime determinant in the absorption of poorly water-soluble drugs and also serves as a rate-limiting step (9). No information is available on the improvement of these drug-like properties of zaleplon. In this article increasing the solubility of zaleplon has been addressed via solid dispersion technique.
The formulation of poorly water-soluble drugs is one of the most challenging tasks to the formulation experts. An enhancement in the solubility and the dissolution rate can improve the oral bioavailability of such drugs, which further improves the therapeutic efficacy and patient compliance. Various techniques have been used to enhance the solubility of poorly water-soluble drugs, including the use of surfactants (10), inclusion complexation (11), use of polymorph (12), and amorphous form of drug micronisation (13) and solid dispersion (14–16). The solubilization of drug from solid dispersion systems is mainly because of the reduction in particle size, increase in the surface area and reduction in the crystallinity that improves dissolution rate. Also, no energy is required to break up the crystal lattice of a drug during dissolution process and drug solubility and wettability may be increased by surrounding hydrophilic carriers (17). The various methods used to prepare solid dispersions are the hot melt method (18,19), solvent evaporation (20), spray drying (21), hot melt extrusion (22), solvent deposition technique (23) and solvent wetting method (24).
The aim of the present study was to enhance the dissolution rate of zaleplon using solid dispersion technique with various hydrophilic polymers. The solvent evaporation method was used to prepare solid dispersion particles of zaleplon. Solid dispersion systems and physical mixtures of zaleplon were prepared with poloxamer F68, polyvinylpyrrolidone K30 (PVP K30), and polyethyleneglycol 6000 (PEG 6000) each in 1:1, 1:3 and 1:5 ratios. The selection of different ratios of polymers was purely on random basis. The solid-state properties of these binary systems were studied by thin layer chromatography, Fourier transformation infrared spectroscopy, X-ray powder diffractometry and differential scanning calorimetry. The dissolution behavior of zaleplon and its binary systems were further evaluated.
TL;DR: Growth of bis(thiourea) cadmium formate (BTCF) single crystals by slow evaporation technique has been reported in this article, where the grown crystals are characterized by powder XRD technique.
Abstract: Growth of bis(thiourea) cadmium formate (BTCF) single crystals by slow evaporation technique has been reported. The grown crystals are characterized by powder XRD technique. Surface morphology of BTCF was studied by scanning electron microscopy (SEM). The UV-vis-IR spectrum confirms the cut-off wavelength of the sample around 290 nm with a wide optical transmission window (290–2000 nm). The laser damage threshold of BTCF is found to be higher than that of KDP. The thermal studied by TGA and DTA techniques confirm the decomposition of the sample around 190 °C. The dc conductivity study shows that the conductivity of BTCF increases with temperature.
TL;DR: Temperature dependence of the dielectric constant in the air-dried sample exhibited peaks at 120 and 155 degrees C which have been identified as temperatures of onset of release of water bound to polar protein components in the amorphous and crystalline regions, respectively.
TL;DR: In this article, the authors presented the details of finite element modeling and validation, blade response under service loading conditions, power coefficient evaluation for the optimum design parameters of the blade configuration, development of failure envelope and fatigue life estimations.
Abstract: Some interesting studies are made in this paper on the life management of a composite wind turbine blade. It presents the details of finite element modeling and validation, blade response under service loading conditions, power coefficient evaluation for the optimum design parameters of the blade configuration, development of failure envelope and fatigue life estimations. Finite element analysis results are found to be in good agreement with existing test results on a typical composite blade configuration. The failure envelope generated from the present modified failure criterion correlates well with the test results on different composite materials. The procedure adopted in this paper can be utilized for optimum design of large size composite wind turbine blades.
TL;DR: This paper demonstrates the application of two soft computing approaches namely artificial neural network (ANN) and neural-fuzzy system to forecast the unevenness of ring spun yarns using cotton fiber properties measured by advanced fiber information system and yarn count as inputs.
Abstract: This paper demonstrates the application of two soft computing approaches namely artificial neural network (ANN) and neural-fuzzy system to forecast the unevenness of ring spun yarns. The cotton fiber properties measured by advanced fiber information system (AFIS) and yarn count have been used as inputs. The prediction accuracy of the ANN and neural-fuzzy models was compared with that of linear regression model. It was found that the prediction performance was very good for all the three models although ANN and neural-fuzzy models seem to have some edge over the linear regression model. The linguistic rules developed by the neural-fuzzy system unearth the role of input variables on the yarn unevenness.
TL;DR: The structure-activity models of the myorelaxant activity of the cromakalim analogues have been investigated with nearly 470 topological descriptors and it is suggested that the substituent groups of 4,6-disubstituted-2,2-dimethylchromans hold scope for further modification in the optimization of activity.
TL;DR: In vitro drug release study of these formulations indicated controlled release of theophylline and about 76 percent drug was released at the end of 12 h.
Abstract: Sustained release floating capsules for theophylline were fabricated using drug:polymer ratio of 30:70. The hydrocolloids were used in different proportions and four formulations were prepared. These formulations were optimized on the basis of buoyancy, matrix integrity, duration of floating and in vitro drug release. All the four formulations showed good buoyancy and matrix integrity. The duration of floating was more than 12 h for all formulations. In vitro drug release study of these formulations indicated controlled release of theophylline and about 76 percent drug was released at the end of 12 h.