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S Nanda

Publications and source records attributed to S Nanda.

At least 19 recordsLinked to original sources
PubMed2006

Parity-violating electron scattering from 4He and the strange electric form factor of the nucleon.

We have measured the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 4He at an average scattering angle = 5.7 degrees and a four-momentum transfer Q2 = 0.091 GeV2 . From these data, for the first time, the strange electric form factor of the nucleon G(E)s can be isolated. The measured asymmetry of A(PV) = (6.72 +/- 0.84(stat) +/- 0.21(syst) x 10(-6) yields a value of G(E)s = -0.038 +/- 0.042(stat) +/- 0.010(syst), consistent with zero.

Journal Article↗
PubMed2006

Current developments using emerging transdermal technologies in physical enhancement methods.

Transdermal drug delivery using patches offers many advantages, but is limited primarily by the stratum corneum barrier. Amongst the various methods to overcome this barrier, physical methods are gaining in popularity and commercial devices development. Macroflux, MTS and Silex are based on microporation, involving use of microneedles that pierce thereby bypassing the stratum corneum. Intraject , Powderject and Helios are based on needleless jet injectors wherein very fine, solid particulate drug, is fired directly into the skin, using high-pressure gas. Med- Tats incorporate use of modified drug-containing tattoos, which bind to the skin, wherein the drug is absorbed. CHADD is based on use of heat, which increases skin - permeation of drugs. High-power, pulsed lasers transmit positive mechanical forces to the skin and create intercellular channels into the skin transiently. Sonophoresis involves use of ultrasound, which transiently disrupts the stratum corneum barrier. This technique offers a non-invasive transdermal extraction of interstitial fluids of sampling body fluids. Modified Liposomes include Ethosomes (containing alcohol) and Transferosomes (containing surfactants), which have enhanced skin permeability. Pulsed magnetic fields may create transient pores in cell membranes, including skin, resulting in increased permeation. Iontophoresis is based on application of electric potential for enhancing the movement of substances to and from the body. Dupel, Ionzyme, Liposite, ETrans, Phoresor and Drionic are based on iontophoresis. GlucoWatch offers non-invasive blood glucose monitoring, based on reverse iontophoresis. This review outlines recent commercial developments in physical transdermal drug delivery technology and the specific devices and applications being targeted by the pharmaceutical industry.

Adjuvants, Pharmaceutic↗
PubMed2005

Q2 dependence of the neutron spin structure function g2(n) at low Q2.

We present the first measurement of the Q2 dependence of the neutron spin structure function g2(n) at five kinematic points covering 0.57 (GeV/c)2 < or = Q2 < or = 1.34 (GeV/c)2 at x approximately = 0.2. Though the naive quark-parton model predicts g2 = 0, nonzero values occur in more realistic models of the nucleon which include quark-gluon correlations, finite quark masses, or orbital angular momentum. When scattering from a noninteracting quark, g2(n) can be predicted using next-to-leading order fits to world data for g1(n). Deviations from this prediction provide an opportunity to examine QCD dynamics in nucleon structure. Our results show a positive deviation from this prediction at lower Q2, indicating that contributions such as quark-gluon interactions may be important. Precision data obtained for g1(n) are consistent with next-to-leading order fits to world data.

Journal Article↗
PubMed2004

Precision measurement of the neutron spin asymmetryA(n)(1) and spin-flavor decomposition in the valence quark region.

We have measured the neutron spin asymmetry A(n)(1) with high precision at three kinematics in the deep inelastic region at x=0.33, 0.47, and 0.60, and Q(2)=2.7, 3.5, and 4.8 (GeV/c)(2), respectively. Our results unambiguously show, for the first time, that A(n)(1) crosses zero around x=0.47 and becomes significantly positive at x=0.60. Combined with the world proton data, polarized quark distributions were extracted. Our results, in general, agree with relativistic constituent quark models and with perturbative quantum chromodynamics (PQCD) analyses based on the earlier data. However they deviate from PQCD predictions based on hadron helicity conservation.

Journal Article↗
PubMed2004

Topical phenytoin suspension and normal saline in the treatment of leprosy trophic ulcers: a randomized, double-blind, comparative study.

OBJECTIVE: To evaluate and compare two strengths of topical phenytoin sodium suspension (2% and 4%) with normal saline in the healing of acute trophic ulcers in leprosy patients. METHODS: A prospective, parallel, double-blind, randomized study was conducted in 45 leprosy inpatients with acute trophic ulcers. Patients were randomized to receive 2%, 4% or normal saline dressing on their ulcers once daily for 4 weeks. Efficacy parameters such as a reduction in the surface area of the ulcer, bacterial culture of the ulcer swab, appearance of healthy granulation tissue, cessation of ulcer discharge and overall gradation of clinical healing and safety were assessed at weekly intervals. RESULTS: The ulcer area reduction was greater in the 2% and 4% phenytoin groups compared with the normal saline group (p<0.001). Appearance of healthy granulation tissue and cessation of ulcer discharge was also observed earlier in the two phenytoin groups. At the end of 4 weeks, 11 ulcers each had healed completely in both the 2% and 4% phenytoin groups compared with none in the control group. There were no statistical differences between the 2% and 4% phenytoin groups. No side effects were reported by any patient. CONCLUSION: Topical phenytoin appears to be an effective, safe and cheap therapeutic option for the healing of trophic ulcers in leprosy patients.

Acute Disease↗
PubMed2003

Cross-section measurement of charged-pion photoproduction from hydrogen and deuterium.

We have measured the differential cross section for the gamman-->pi(-)p and gammap-->pi(+)n reactions at theta(c.m.)=90 degrees in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at E(gamma) greater, similar 3.3 GeV exhibit a global scaling behavior for both pi(-) and pi(+) photoproduction, consistent with the constituent counting rule and the existing pi(+) photoproduction data. Possible oscillations around the scaling value are suggested by these new data. The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi(-) to pi(+) photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.

Journal Article↗
PubMed2002

Efficient enantioselective reduction of ketones with Daucus carota root.

A novel and efficient reduction of various prochiral ketones such as acetopehones, alpha-azido aryl ketones, beta-ketoesters, and aliphatic acyclic and cyclic ketones to the corresponding optically acive secondary alcohols with moderate to excellent chemical yield was achieved by using Daucus carota, root plant cells under extremely mild and environmentally benign conditions in aqueous medium, has been described. Many of these optically active alcohols are the potential chiral building blocks for the synthesis of pharmaceutically important molecules and asymmetric chiral ligands. Hence, this biocatalytic approach is found to be the most suitable for the preparation of a wide range of chiral alcohols and gave inspiration for the development of a new biotechnological process.

Acetophenones↗
PubMed2001

Dynamics of the 16O(e, e'p) reaction at high missing energies.

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Journal Article↗
PubMed2001

Short- and long-term effects of fraternity and sorority membership on heavy drinking: a social norms perspective.

This study sought to determine whether the well-established relation between fraternity/sorority (Greek) membership and heavy alcohol use persists beyond the college years and whether some common third variables might account for the relation between Greek status and heavy drinking. During each of 4 years of college and 1 additional year, young adults (N = 319) completed measures of alcohol use, personality, alcohol expectancies, and environmental influences on drinking. Throughout the college years, Greeks consistently drank more heavily than non-Greeks. Statistically controlling for previous alcohol use did not eliminate this effect. However, Greek status did not predict postcollege heavy drinking levels. Also, perceived peer norms for heavy drinking mediated the relation between Greek affiliation and heavy alcohol use. Results are discussed in terms of situational determinants of heavy alcohol involvement in young adults.

Adult↗
PubMed1999

Captopril-induced toxic epidermal necrolysis and agranulocytosis successfully treated with granulocyte colony-stimulating factor.

Captopril-induced bone marrow suppression is rare, except in certain high-risk patient populations. Severe exfoliative rashes have also been associated with captopril, but a combined presentation of toxic epidermal necrolysis and agranulocytosis has not been previously described. We report an unusual case of captopril-induced toxic epidermal necrolysis with agranulocytosis in a patient with no known risk factors. The bone marrow suppression was successfully treated using granulocyte colony-stimulating factor (G-CSF), and the white blood cell (WBC) count recovered within 3 days after starting therapy. This case underscores the early experience with captopril, which showed a strong correlation between high doses used to treat hypertension and bone marrow suppression.

Agranulocytosis↗
PubMed1998

Multiple promoters direct stimulus and temporal specific expression of brain-derived neurotrophic factor in the somatosensory cortex.

Neuronal activity rapidly induces expression of brain-derived neurotrophic factor (BDNF) in the adult rat cortex. The rat BDNF gene has four differentially regulated promoters, each of which produce an mRNA containing a unique 5' exon (I-IV) and a common 3' exon (V) that encodes the mature BDNF protein. The present study used an exon-specific RT-PCR analysis to determine the time course of the induction from both seizures and whisker stimulation. Our data show that specific promoters are utilized at different stages of the activity-dependent induction of the BDNF gene. Furthermore, the data show a differential utilization of the four promoters following a specific stimulus.

Animals↗
PubMed1998

Massive mature solid teratoma of the ovary with gliomatosis peritonei.

Glial implants on peritoneum and omentum may occur with mature solid teratoma of the ovary (gliomatosis peritonei). The case of a 17-year-old girl is presented, who had a massive solid ovarian teratoma with glial implants on visceral peritoneum and omentum. The massive size of the tumour posed difficulty in diagnosis. CT demonstrated a large teratoma. At laparotomy, the seedlings were initially thought to be evidence of malignancy and hysterectomy was offered which was refused by the parents. Oophorectomy was performed and the benign nature of the tumour and implants was seen on histopathology. It is important to recognize the benign nature of glial seedlings in such cases to avoid unnecessary extensive surgery.

Adolescent↗
PubMed1997

Nonunion of uterine incision: a rare cause of secondary postpartum haemorrhage: a report of 2 cases.

Secondary postpartum haemorrhage after Caesarean section due to non-union of the uterine incision is an unusual complication. Two women who had had lower segment Caesarean section for placenta praevia presented after 2 and 3 weeks respectively with shock due to massive postpartum haemorrhage. The uterine scars had not healed in both of these women who were managed by emergency subtotal hysterectomy.

Adult↗
PubMed1996

Risk analysis in the valuation of medical practices.

Risk analysis techniques used in valuing medical practices are discussed. Employing these techniques provides superior information to the analyst than using a single estimate for uncertain variables. Examples of scenario analysis, sensitivity analysis, and simulation are presented. These tools can be easily implemented with spreadsheet software.

Computer Simulation↗