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1.
J Chem Phys ; 159(12)2023 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-38127384

RESUMEN

We simulate the nonadiabatic dynamics of photo-induced isomerization and dissociation in ethylene using ab initio classical trajectories in an extended phase space of nuclear and electronic variables. This is achieved by employing the linearized semiclassical initial value representation method for nonadiabatic dynamics, where discrete electronic states are mapped to continuous classical variables using either the Meyer-Miller-Stock-Thoss representation or a more recently introduced spin mapping approach. Trajectory initial conditions are sampled by constraining electronic state variables to a single initial excited state and by drawing nuclear phase space configurations from a Wigner distribution at a finite temperature. An ensemble of classical ab initio trajectories is then generated to compute thermal population correlation functions and analyze the mechanisms of isomerization and dissociation. Our results serve as a demonstration that this parameter-free semiclassical approach is computationally efficient and accurate, identifying mechanistic pathways in agreement with previous theoretical studies and also uncovering dissociation pathways observed experimentally.

2.
Opt Lett ; 44(24): 5977-5980, 2019 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32628197

RESUMEN

Anti-reflection coatings are widely used throughout the field of optical technology such as in corrective eyeglasses, camera lenses, and microscope optics, to improve the transmittance and reduce the reflectance of glass and other transparent materials. To date, these coatings have suffered from relatively poor scratch resistance and high scratch visibility compared to standard glasses. This has limited their use in applications requiring high mechanical durability such as on the chemically strengthened glasses widely used in modern touch screen devices. Here extremely scratch-resistant anti-reflection coatings are fabricated using industrially scalable reactive sputtering processes. These coatings provide a combination of surface reflectance below 0.7%, low color shifts, nanoindentation hardness as high as 18 GPa, and levels of scratch resistance which dramatically exceed commercial chemically strengthened glasses. An interdisciplinary opto-mechanical design approach has enabled a significant paradigm shift in the use of high-precision optical coatings for mechanically demanding applications. As a direct outcome of the work reported in this Letter, similar coating designs have been successfully deployed on millions of consumer electronics devices with very robust field performance.

3.
Indian J Clin Biochem ; 24(3): 215-22, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23105838

RESUMEN

Inherited metabolic disorders are a heterogeneous group of genetic conditions mostly occurring in childhood. They are individually rare but collectively numerous, causing substantial morbidity and mortality. We have retrospectively reviewed a total of eight hundred and sixty nine cases with different age groups that had been referred from several diagnostic centers and hospitals of India to the Department of Metabolism in Narayana Hrudayalaya, as cases suspected with inborn errors of metabolism. Advanced techniques applied were to diagnose the disorders of inborn errors of metabolism. Data analyzed indicates occurrence of several metabolic disorders in our population. The need to screen for an inborn error of metabolism arises out of the fact that most cases take to irreversible effects as time progress. Emphasis has to be laid on early detection and prompt management, which could help in alleviating symptoms and preventing complications and consequent incapacitation.

4.
Indian J Clin Biochem ; 23(4): 407-9, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23105798

RESUMEN

Defects in biotin metabolism are mainly associated with either the enzyme Biotinidase or Holocarboxylase synthetase. Defects in either enzymes depletes biotin utilization by the cells. Holocarboxylase synthetase deficiency is an inherited disorder in which the body is unable to use the vitamin biotin effectively. This condition is inherited in an autosomal recessive pattern. We present a case of a 9 year old girl with atypical symptomology as a case holocarboxylase synthetase deficiency, who demonstrated an increased excretion of propionic and methyl malonic acids, with her biotinidase activity being normal. She demonstrated remarkable improvement on biotin supplementation.

5.
Autism Res ; 10(12): 1919-1928, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28856816

RESUMEN

Autism spectrum disorder (ASD) is a neuro developmental disorder, reported to be on a rise in the past two decades. Thyroid hormone-T3 plays an important role in early embryonic and central nervous system development. T3 mediates its function by binding to thyroid hormone receptors, TRα and TRß. Alterations in T3 levels and thyroid receptor mutations have been earlier implicated in neuropsychiatric disorders and have been linked to environmental toxins. Limited reports from earlier studies have shown the effectiveness of T3 treatment with promising results in children with ASD and that the thyroid hormone levels in these children was also normal. This necessitates the need to explore the genetic variations in the components of the thyroid hormone pathway in ASD children. To achieve this objective, we performed genetic analysis of ligand binding domain of THRA and THRB receptor genes in 30 ASD subjects and in age matched controls from India. Our study for the first time reports novel single nucleotide polymorphisms in the THRA and THRB receptor genes of ASD individuals. Autism Res 2017, 10: 1919-1928. ©2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Thyroid hormone (T3) and thyroid receptors (TRα and TRß) are the major components of the thyroid hormone pathway. The link between thyroid pathway and neuronal development is proven in clinical medicine. Since the thyroid hormone levels in Autistic children are normal, variations in their receptors needs to be explored. To achieve this objective, changes in THRA and THRB receptor genes was studied in 30 ASD and normal children from India. The impact of some of these mutations on receptor function was also studied.


Asunto(s)
Trastorno del Espectro Autista/genética , Genes erbA/genética , Receptores de Hormona Tiroidea/genética , Trastorno del Espectro Autista/sangre , Niño , Femenino , Humanos , India , Masculino , Mutación/genética , Polimorfismo de Nucleótido Simple/genética , Receptores de Hormona Tiroidea/sangre
6.
Indian J Clin Biochem ; 21(2): 49-52, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23105613

RESUMEN

Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) has been inducted as a mediator of inflammation in rheumatoid arthritis. Methotrexate combination therapy forms an important component of the treatment regimen in rheumatoid arthritis. The present study was undertaken to evaluate the influence of Methotrexate-Hydroxychloroquine (MTX-HCQ) combination and Sulfsalazine- Hydroxychloroquine (SSZ-HCQ) combination on the expression GM-CSFR in neutrophils isolated from synovial fluids. 15 cases of confirmed rheumatoid arthritis patients who presented at the hospital for surgical correction of joint deformities were selected for the study. Neutrophils isolated from the synovial fluids were used as the source of the receptor for quantitation on an enzyme immunoassay (EIA). The EIA was developed and standardized in our laboratory for quantification of the GM-CSF R. The findings are suggestive of the fact that the administration of MTX-HCQ combination has positive influence on the expression of the GM-CSF R on neutrophils as against SSZ-HCQ combination. The physiological basis of this increase needs further investigation.

7.
Neurol India ; 53(3): 333-4, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16230804

RESUMEN

Recurrent stupor in children is an uncommon clinical problem with a wide differential diagnosis; inherited metabolic disorders account for a vast majority. We report a 9-year-old girl with recurrent episodes of stupor. Initial episode was treated as viral encephalitis and the second episode was managed as non-convulsive status epilepticus. Hyperammonemia was detected in the last episode. Metabolic work-up after dietary protein challenge revealed classical biochemical features of lysinuric protein intolerance. She was managed with protein-restricted diet, which resulted in marked neurological improvement. LPI is a rare inherited metabolic disorder due to membrane transport defect of cationic amino acids.


Asunto(s)
Errores Innatos del Metabolismo de los Aminoácidos/metabolismo , Amoníaco/sangre , Coma/etiología , Lisina/orina , Errores Innatos del Metabolismo de los Aminoácidos/terapia , Errores Innatos del Metabolismo de los Aminoácidos/orina , Aminoácidos/sangre , Aminoácidos/orina , Niño , Dieta con Restricción de Proteínas , Femenino , Humanos , Lisina/sangre
8.
Pain ; 27(1): 51-55, 1986 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2947031

RESUMEN

Chronic pain has been considered as a variant of depression or as a masked depression. In an attempt to unravel the complex relationship between chronic pain and depression, we administered the TRH stimulation test to a uniform group of chronic pain patients classified into those with and without major depression using DSM-III criteria. Eighteen percent showed blunting of TSH response to TRH. There was no significant difference between the two groups.


Asunto(s)
Dolor de Espalda/fisiopatología , Trastorno Depresivo/fisiopatología , Hormona Liberadora de Tirotropina , Adulto , Dolor de Espalda/sangre , Dolor de Espalda/etiología , Enfermedad Crónica , Trastorno Depresivo/sangre , Trastorno Depresivo/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hormona Liberadora de Tirotropina/sangre , Hormona Liberadora de Tirotropina/fisiología
9.
Indian J Exp Biol ; 41(4): 357-9, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15255647

RESUMEN

Malaria has been reportedly increasing in incidence on the globe. Evidence from clinical studies supports a role for cytokines in the pathogenesis of cerebral malaria. Given the stimulatory effect of the ligand GM-CSF on the synthesis and release of the pyrogenic cytokine TNF alpha, the present study has been undertaken to investigate a possible role of GMCSF receptor in the pathogenesis of both Plasmodium vivax and Plasmodium falciparum malaria. An enzyme immunoassay developed by us at our laboratory for the quantitation of GM-CSF receptor has been used. No changes in the concentration of the receptor have been indicated either at the time of diagnosis or after treatment. In addition, an intercomparison of the receptor concentration between the P. vivax and P. falciparum groups does not show any significant difference. The results suggest that GM-CSF receptor has no significant role in the pathogenesis of either type of malaria.


Asunto(s)
Malaria Falciparum/metabolismo , Malaria Vivax/metabolismo , Plasmodium falciparum/metabolismo , Plasmodium vivax/metabolismo , Receptores de Factor Estimulante de Colonias de Granulocitos y Macrófagos/fisiología , Adolescente , Adulto , Animales , Antimaláricos/uso terapéutico , Niño , Preescolar , Ensayo de Inmunoadsorción Enzimática , Humanos , Malaria Falciparum/diagnóstico , Malaria Falciparum/terapia , Malaria Vivax/diagnóstico , Malaria Vivax/terapia , Plasmodium falciparum/patogenicidad , Plasmodium vivax/patogenicidad
10.
Indian J Clin Biochem ; 18(2): 23-6, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23105388

RESUMEN

A 3 month old male child was brought to the hospital with complaints of skin rashes, developmental delay, seizures, seborrheic dermatitis, alopecia and mild, acidosis. The child was subjected to a simple metabolic screening protocol. The result of the screening and the clinical symptoms provided an index pointing towards biotinidase deficiency., a rare autosomal recessive, inherited metabolic disorder. The enzyme was then assayed by using n-biotinylp-aminobenzoate as substrate and the diagnosis confirmed. A follow-up of the case indicated the efficacy, of biotin supplementation in biotinidase deficiency.

11.
Indian J Clin Biochem ; 18(2): 87-92, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23105397

RESUMEN

Hereditary fructose intolerance is a rare cause of hepatic cirrhosis in the young. The disorder has a reported frequency of 1 in 20000 live births and no case has been reported from India so far. We report two cases of hereditary fructose intolerance, both with bilateral cataracts and one with cirrhosis of the liver.

12.
Indian J Clin Biochem ; 13(2): 126-8, 1998 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23105194

RESUMEN

In a pilot study with five oral cancer patients undergoing radiotherapy (RT) three were given Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) as a protective agent to reduce the mucosal inflammation during radiotherapy. The myeloperoxidase (MPO) enzyme activity in WBC was quantitated. The three patients showed a significant increase in the MPO activity when compared with two untreated controls indicating the efficacy of GM-CSF as a protective agent. It is suggested that further detailed studies with larger number of patients would be useful.

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