Search Results - (Author, Cooperation:N. Agrawal)

2018-04-10

The American Association of Immunologists (AAI)

0022-1767

1550-6606

Medicine

2011-08-06

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Brain Neoplasms/*genetics ; Chromosomes, Human, Pair 1/genetics ; Chromosomes, Human, Pair 19/genetics ; DNA Helicases/chemistry/*genetics/metabolism ; DNA-Binding Proteins/chemistry/*genetics/metabolism ; Exons ; Female ; Genes, Tumor Suppressor ; Genetic Predisposition to Disease ; Humans ; Loss of Heterozygosity ; Male ; *Mutation ; Mutation, Missense ; Oligodendroglioma/*genetics ; Receptor, Notch2/genetics ; Repressor Proteins/chemistry/*genetics/metabolism ; Sequence Analysis, DNA

2011-07-30

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Carcinoma/drug therapy/*genetics/virology ; Carcinoma, Squamous Cell ; Cell Cycle Proteins/*genetics ; Codon, Nonsense ; Exons ; F-Box Proteins/*genetics ; Gene Dosage ; *Genes, Tumor Suppressor ; Genes, p53 ; Head and Neck Neoplasms/drug therapy/*genetics/virology ; Humans ; INDEL Mutation ; *Mutation ; Mutation, Missense ; Neoplasms, Squamous Cell/drug therapy/*genetics/virology ; Oligonucleotide Array Sequence Analysis ; Oncogenes ; Papillomaviridae/isolation & purification ; Papillomavirus Infections/virology ; Receptor, Notch1/chemistry/*genetics ; Sequence Analysis, DNA ; Smoking ; Tobacco ; Ubiquitin-Protein Ligases/*genetics

2018-12-04

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

1089-7550

AIP Digital Archive

Physics

A self-consistent finite difference method for the simulation of quantum well electron transfer structures is developed and applied to optimize InGaAsP/InP/InAlAs structures for fast optical switching devices. Simultaneous solution of Poisson's equation, continuity equation, and Schrödinger's equation on a discretized mesh yields a fast and accurate simulation method which may be applied to arbitrary layer structures and needs no artificial assumptions like abrupt space charge layers. Because of the exact treatment of charge distribution and leakage current the simulation gives new insight into the performance of barrier, reservoir, and quantum well electron transfer structures, which could not be found by previous approximate theories. With this method we calculate the important physical parameters of these devices, namely, the shift of the optical absorption edge, band filling, leakage current, and capacitance. In addition, each layer is investigated separately with respect to its influence on device performance and fabrication tolerances; the results are used for optimization. Moreover, the exact numerical simulation is used to derive simplified relations for the dependence of band filling, capacitance, and high speed behavior on the heterostructure design. © 1994 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We report substantial progress in the growth of multi-quantum-well electron transfer optical modulator structures by metalorganic vapor phase epitaxy, which is made possible as a consequence of the highly abrupt modulation doping of donors and acceptors in InP-reservoir and InAlAs-barrier layers, respectively. Due to a large thermionic emission barrier provided by the type II InP/InAlAs interface, the InGaAsP/InP/InAlAs devices exhibit extremely low leakage current densities. We observe distinct and sharp features related to absorption quenching in differential transmission spectroscopy. Moreover, the saturation intensities of electron transfer modulators are determined. The underlying physical mechanism is discussed.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Recently, a novel optical modulator heterostructure has been introduced based on voltage controlled electron transfer from a reservoir to a closely spaced quantum well. It has proven to exhibit large absorptive and refractive modulation at high speed and low power dissipation. In order to achieve monolithic integration with the existing high quality InGaAsP/InP lasers for high bit-rate systems, it is crucial to implement such devices within the same material system. In this letter, we demonstrate for the first time, InGaAsP/InP electron-transfer modulators grown using metalorganic vapor phase epitaxy.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

The rapid decrease in the integral inelastic cross sections, when rotational energy transfer ||ΔE|| is greater than a critical value (||ΔE||*), has been explained quantitatively for the systems CO2–H2, CO2–He, Na2–He, Na2–Ne, LiH–He, and N2–Ar on the basis of the model proposed by Dexheimer et al. An expression for ||ΔE||* has been obtained that shows the increase in ||ΔE||* with the increase in the reduced mass μ, initial rotational quantum number ji, and initial relative energy of the translational motion Ki. The predictions of the model for CO2–X (X=Ne, Ar, Kr, Xe) are also reported.

Electronic Resource

1360-0443

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Psychology

Aims. This study was established to determine if users of ecstasy had greater tooth wear than a comparison group of non-users . Design. The study involved a direct comparison between two groups of young people gathered by a peer information network and divided by the response to the question "Do you take ecstasy? " Setting. The information network was established at the Maryland Centre in Liverpool (UK). Besides offering advice on drug and sex-related problems this centre distributes free condoms and is therefore visited by many young people who would not consider themselves to have these problems . Participants. There were 30 users and 28 non-users with no significant difference in the gender ratio. Age was not recorded to maintain absolute confidentiality, but all the participants appeared to be of student age . Measurements. Tooth wear was measured using the index of Smith & Knight. The social and drug-taking profile of the two groups was ascertained by questionnaire . Findings. It was found that the mean ( STD) tooth wear score for the back teeth was 0.96 0.16 in the users compared with 0.12 0.08 for the comparison group. These values were significantly different ( p 0.001). The values for the front teeth were not significantly different. Many users were aware of clenching their teeth 12 or even 24 hours after taking the drug. Conclusion. Taking ecstasy results in an increased likelihood of tooth wear on the back teeth. This is likely to result from clenching the teeth in the acidic environment caused by carbonated (fizzy) drinks.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Using 131I as tracer, iodine uptake by various thyroid and non-thyroid tissues has been reported in Channa punctatus in which vitamin C deficiency was experimentally induced by feeding vitamin C deficient diet to a level when morphological deficiency syndromes appeared. This was compared with a parallel control, fed a complete diet. The study showed a highly significant decrease in iodine uptake by thyroid tissues in vitamin C deficient fish as compared to the controls. However, the blood and other non-thyroid tissues recorded a significant increase in absorption and distribution of iodine. These findings suggested hypofunctioning of thyroid gland due to a prolonged deficiency of vitamin C.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Comparative tissue ascorbic acid levels in four species of major carp viz., Labeo rohila, L. calbasu, Cirrhina tnrigala and Catla catla, were investigated. The ascorbic acid level was found to be the highest in the spleen in the four species studied (range 430–380 μg/g) followed by the anterior (adrenal) kidney, gonads, liver, renal kidney, brain and/or eye. Heart and blood had the lowest levels (range 26–18 μg/ml) amongst the tissues studied. Overall tissue ascorbic acid levels were the highest in L. rohita and the lowest in C. mrigala. Investigation on seasonal variations in blood and kidney ascorbic acid levels of Notopterus notopterus revealed peak levels in spring (February-April) and the lowest levels in the postspawning period (August-September).

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Pyridoxine deficiency was induced in a population of Channa punctatus. The deficiency effects were increased by adding 4-deoxypyridoxine as an antagonist. Haematological and haematopoietic changes were studied. The significant changes in peripheral blood appeared after 150 days in the antagonist treated group and 180 days in the group on the deficient diet. After 240 days when morphological changes and an increased mortality also appeared, the changes in RBC and related values (haemoglobin, haematocrit, MCV, MCH & MCHC) were highly significant and indicated hypochromic microcytic anaemia; this was accompanied by leukopenia. The haematopoietic studies revealed significant increase in the earlier stages of erythrocytic development (basophilic erythroblasts and polychromatophilic eryth-roblasts) with a simultaneous decrease in the later stages (young and mature reticulocytes). A series of pathological disorders in the various developing cells were recorded in the imprints of haematopoietic tissues. The pyridoxine specificity of these changes were confirmed by remedial treatment for a month.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The results of a series of experiments on Channa punctatus previously conditioned to a complete synthetic diet and later fed vitamin C deficient diet for 210 days followed by 30 days of recovery with fortified vitamin C ration are reported. The survival, growth, morphological abnormalities and biochemical changes in tissue ascorbic acid and cholesterol levels were studied.Deficiency of vitamin C resulted in a mortality of up to 25% and retarded growth accompanied by anorexia and loss of weight. Marked skeletal abnormalities, viz., lordosis, scoliosis and degenerative changes in the thoracic vertebrae were revealed by X-ray studies. Biochemical investigations showed a significant decrease in blood and kidney ascorbic acid levels within a month of feeding the deficient diet. A prolonged deficiency beyond 150 days resulted in a rapid rise in the cholesterol content of the liver. These biochemical changes were reversed when vitamin C was added to the ration.

Electronic Resource

1439-0426

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition

Histochemical analysis of the cellular components as a supplement to histological studies shows that the epithelia of lips and associated structures in Channa striata are of a mucogenic and unkeratinized nature. Voluminous mucous cells in the lip eithelia secrete profusely at the surface to lubricate and protect the epithelia from abrasion during feeding. Capacity of the folds of skin to distend is an important adaptation enabling the jaws to protrude ant assist the fish to engulf relatively large-size prey. Profuse mucus secretion at the surface of skin folds may reduce the resistance generated during protrusion of jaws when feeding. The role of sacciform cells located in the rostral cap epithelium is discussed in the production of the fish toxins. Poorly-developed taste buds in the epithelia of lips and rosual cap sugest that the gustatory function is of less importance in this active predatory fish which feeds mainly by sight.

Electronic Resource

1365-2761

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Medicine

Abstract. Experiments with a purified vitamin test diet on newly hatched Cirrhina mrigala Hamilton, a major carp of great piscicultural importance, are reported. Experimentally induced vitamin C deficiency for 330 days was followed by recovery treatment for 30 days. Retarded growth and greater mortality accompanied by structural deformities such as lordosis and scoliosis, increasing with prolonged deficiency, were recorded. Haematological and haematopoietic studies revealed hypochromic macrocytic anaemia accompanied by anisocytosis. Correlated studies on erythropoiesis revealed increased reticulocytes and an overall decrease in small lymphoid haemoblasts. Total and differential leucocyte counts revealed leucopenia and thrombopenia accompanied by an increase in neutrophils and eosinophils. Recovery treatment halted and in some cases even compensated these pathophysio-logical changes to some extent.

Electronic Resource

1365-2761

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Medicine

Abstract. Pyridoxine deficiency was experimentally produced in a population of Channa punctatus Bloch by feeding a pyridoxine deficient vitamin test diet for 240 days. The deficiency effects were further accentuated in another group of fish by adding 4-deoxypyridoxine as an antagonist to the deficient diet. The behaviour, general morphology and growth of these fish were compared with control fish maintained on a complete vitamin test diet. The behavioural study revealed a series of nervous disorders such as ataxia, hyperirritability and muscular spasm followed by convulsions, fits, anorexia and paralysis in the posterior region during advanced stages of the deficiency. Gross morphological changes recorded were retarded growth and loss of weight resulting in a pinhead condition; integumentary damage such as scale loss, leakage of oedematous fluid and abnormal pigmentation, opacity of the lens resulting in complete blindness and enlargement and nodule formation in the spleen and kidney. Recovery treatment for 30 days comprising restoration of dietary supply of pyridoxine supplemented by intramuscular injections brought about considerable recovery in the fish with dietary pyridoxine deficiency but the antagonist-treated deficient group showed little recovery, although further deterioration was halted.

Electronic Resource

1365-2761

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Medicine

Abstract. Morphological, behavioural and haematological changes in Channa punctatus caused by infection with the digenean Isoparorchis hypselobagri are reported. Morphological changes include partial necrosis of fin tissue, scale loss (particularly along the opercula and caudal peduncle) and loss of pigmentation, together with considerable damage to the viscera, especially the gonads, and the abdominal muscles. Behavioural changes include partial or complete loss of equilibrium, irritability and convulsions. Haematological changes observed were a significant decrease in haemoglobin and haematocrit values resulting in hypochromicmacrocytic and normochromicnormocytic anaemia together with an increase in total leucocyte number. Significant decreases in blood glucose level and liver glycogen content were also observed. Some of the changes could be partially compensated by providing a bigger food ration. Compensatory effects were observed for haemoglobin and haematocrit values and leucocyte number. However, an increase in diet could not arrest the significant decrease in blood glucose level and liver glycogen content. The possible effects of parasitism on the utilization and productivity of C. punctatus are discussed.

Electronic Resource

1365-2036

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Aim : In a predefined analysis, data were pooled from eight blinded, randomized, controlled trials, and separately from three long-term, open-label trials to determine the rate of upper gastrointestinal ulcer complications with the cyclo-oxygenase-2 selective inhibitor, valdecoxib, vs. non-selective non-steroidal anti-inflammatory drugs.Methods : In randomized, controlled trials, 7434 osteoarthritis and rheumatoid arthritis patients received placebo (n = 973), valdecoxib 5–80 mg daily (n =4362), or a non-selective non-steroidal anti-inflammatory drug (naproxen, ibuprofen or diclofenac; n =2099) for 12–26 weeks. In long-term, open-label trials, 2871 patients received valdecoxib 10–80 mg daily for up to 1 year. All potential events were reviewed by a blinded, independent review committee based on a priori definitions of ulcer complications (perforations, obstructions, bleeds).Results : In randomized, controlled trials, 19 of 955 potential events were adjudicated to be ulcer complications. Valdecoxib was associated with a significantly lower ulcer complication rate than non-selective non-steroidal anti-inflammatory drugs (0.68% vs. 1.96%, all patients; 0.29% vs. 2.08%, non-aspirin users; P 〈 0.05). In long-term, open-label trials, seven of 310 potential events were adjudicated to be ulcer complications; the annualized incidence for valdecoxib was 0.39% (seven of 1791 patient-years) for all patients and 0.2% (three of 1472 patient-years) for non-aspirin users.Conclusions : Valdecoxib, including above recommended doses, is associated with a significantly lower rate of upper gastrointestinal ulcer complications than therapeutic doses of non-selective non-steroidal anti-inflammatory drugs.

Electronic Resource

0022-0248

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Geosciences

Physics

Electronic Resource

0022-0248

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Geosciences

Physics

Electronic Resource