Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Sci Total Environ ; : 174454, 2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38969110

RESUMO

The cloud responses to global warming are captured in various global climate models with distinct inferences on changes in cloud vertical structure as function of surface warming. However, long term observational evidences are scarce to validate the model outputs. Here, we have studied the changes in radiosonde derived cloud macro-physical properties and their association with other atmospheric variables during the period 2000-2019 in response to warming climate over the Indian summer monsoon region. We have observed a statistically significant increase in the frequency of cloudy days (~13 % decade-1), high-level clouds (HLCs ~11 % decade-1) and simultaneous decrease in low-level clouds (LLCs ~8 % decade-1) over the Indian region during the monsoon season. The multiple linear regression, principle component analyses and further correlation analyses suggest significant associations between cloud vertical structure variations and large-scale climate indicators, such as global warming and El Niño-Southern Oscillation. The vertical extension of the tropospheric column and the upward shift of clouds, attributed to global warming, explain the changes observed in both HLCs and LLCs. These results contribute to a deeper understanding of the dynamic interplay between global climate change and regional cloud dynamics, with implications for weather and climate modeling.

2.
AJNR Am J Neuroradiol ; 45(6): 693-700, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38782592

RESUMO

BACKGROUND AND PURPOSE: The presence of spot sign is associated with a high risk of hematoma growth. Our aim was to investigate the timing of the appearance, volume, and leakage rate of the spot sign for predicting hematoma growth in acute intracerebral hemorrhage using multiphase CTA. MATERIALS AND METHODS: In this single-center retrospective study, multiphase CTA in 3 phases was performed in acute intracerebral hemorrhage (defined as intraparenchymal ± intraventricular hemorrhages). Phases of the spot sign first appearance, spot sign volumes (microliter), and leakage rates among phases (microliter/second) were measured. Associations between baseline clinical and imaging variables including spot sign volume parameters (volume and leakage rate divided by median) and hematoma growth (>6 mL) were investigated using regression models. Receiver operating characteristic analysis was used as appropriate. RESULTS: Two hundred seventeen patients (131 men; median age, 70 years) were included. The spot sign was detected in 21.7%, 30.0%, and 29.0% in the first, second, and third phases, respectively, with median volumes of 19.7, 31.4, and 34.8 µl in these phases. Hematoma growth was seen in 44 patients (20.3%). By means of modeling, the following variables, namely the spot sign appearing in the first phase, first phase spot sign volume, spot sign appearing in the second or third phase, and spot sign positive and negative leakage rates, were associated with hematoma growth. Among patients with a spot sign, the absolute leakage rate accounting for both positive and negative leakage rates was also associated with hematoma growth (per 1-µl/s increase; OR, 1.26; 95% CI, 1.04-1.52). Other hematoma growth predictors were stroke history, baseline NIHSS score, onset-to-imaging time, and baseline hematoma volume (all P values < .05). CONCLUSIONS: The timing of the appearance of the spot sign, volume, and leakage rate were all associated with hematoma growth. Development of automated software to generate these spot sign volumetric parameters would be an important next step to maximize the potential of temporal intracerebral hemorrhage imaging such as multiphase CTA for identifying those most at risk of hematoma growth.


Assuntos
Hemorragia Cerebral , Humanos , Masculino , Feminino , Hemorragia Cerebral/diagnóstico por imagem , Idoso , Estudos Retrospectivos , Pessoa de Meia-Idade , Hematoma/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Idoso de 80 Anos ou mais , Angiografia Cerebral/métodos , Progressão da Doença , Valor Preditivo dos Testes
5.
Asian J Neurosurg ; 16(3): 587-588, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34660374

RESUMO

Atraumatic subdural bleed often presents with diagnostic and management dilemma. This is a case of a 36-year male who presented with acute onset headache while at rest without any focal neurodeficit. Computed Tomographic Scan of brain revealed subdural hematoma. Cerebral Digital Subtraction Angiography showed a same sided focal dye extravasation which corresponded exactly to the inner margin of the subdural bleed. Though the patient opted out for surgical management this imaging and DSA finding correlated with the "Ghost Aneurysm" concept in acute atraumatic subdural bleeds and its early recognition is an important imaging marker for caution for hematoma expansion.

6.
Ann Indian Acad Neurol ; 24(1): 110-111, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33911400
7.
J Neuroimaging ; 31(3): 541-550, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33783929

RESUMO

BACKGROUND AND PURPOSE: Manual segmentation of infarct volume on follow-up MRI diffusion-weighted imaging (MRI-DWI) is considered the gold standard but is prone to rater variability. We assess the variability of manual segmentations of MRI-DWI infarct volume. METHODS: Consecutive patients (May 2018 to May 2019) with the anterior circulation stroke and endovascularly treated were enrolled. All patients underwent 24- to 32-hour follow-up MRI. Three users manually segmented DWI infarct volumes slice by slice twice. The reference standard of DWI infarct volume was generated by the STAPLE algorithm. Intra- and interrater reliability was evaluated using the intraclass correlation coefficient (ICC) by comparing manual segmentations with the reference standard. Spatial measurements were evaluated using metrics of the Dice similarity coefficient (DSC). Volumetric measurements were compared using the lesion volume. RESULTS: The dataset consisted of 44 patients, mean (SD) age was 70.1 years (±10.3), 43% were women, and median baseline NIHSS score was 16. Among three users, the mean DSC for MRI-DWI infarct volume segmentations ranged from 80.6% ± 11.7% to 88.6% ± 7.5%, and the mean absolute volume difference was 2.8 ± 6.8 to 13.0 ± 14.0 ml. Interrater ICC among the users for DSC and infarct volume was .86 (95% confidence interval [95% CI]: .78-.91) and .997 (95% CI: .995-.998). Intrarater ICC for the three users was .83 (95% CI: .69-.93), .84 (95% CI: .72-.91), and .80 (95% CI: .64-.89) for DSC, and .99 (95% CI: .987-.996), .991 (95% CI: .983-.995), and .996 (95% CI: .993-.998) for infarct volume. CONCLUSIONS: Manual segmentation of infarct volume on follow-up MRI-DWI shows excellent agreement and good spatial overlap with the reference standard, suggesting its usefulness for measuring infarct volume on 24- to 32-hour MRI-DWI.


Assuntos
Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Idoso , Algoritmos , Infarto Encefálico/terapia , Procedimentos Endovasculares/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
8.
J Assoc Physicians India ; 67(9): 14-16, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31561681

RESUMO

AIMS: To study the clinical, radiological, cerebrospinal fluid profile of noncompressive myelopathy and to study various etiologies of non-compressive myelopathies in causation of quadriplegia and paraplegia. STUDY DESIGN: Observational study. PLACE AND DURATION OF STUDY: Department of Neurology, Govt. Medical College, Kota in year 2015 and 2016. METHODOLOGY: All the patients presented with myelopathy and MRI spine not showing any significant compression included in study. To know the etiology of non-compressive myelopathy patients were investigated including routine blood tests, cerebrospinal fluid analysis and visual evoked potentials, MRI of the brain, and immunological, infectious, and metabolic profile based on the pattern of involvement. RESULTS: The study had 80 patients with a median age of 38 years and male: female ratio 1.5:1. Patients were divided into acute myelopathy and chronic myelopathy. Forty four patients presented with acute myelopathy whereas 36 patients had chronic myelopathy. The causes of Acute myelopathy were post infectious myelitis (13), neuromyelitis optica spectrum disorder (NMOSD) (6), multiple sclerosis (MS) (2), connective tissue disorders (1), acute disseminated encephalomyelitis (4) and Idiopathic (18). The causes of Chronic myelopathy were Vitamin B12 deficiency (8), MS (2), mixed connective tissue disease (1), Copper deficiency (1), hepatic myelopathy (1), radiation (1), hereditary spastic paraparesis (1) and idiopathic (21). CONCLUSION: Underlying etiology like demyelinating, infectious/post infectious, autoimmune or nutritional was found in 52% patients of non-compressive myelopathy.


Assuntos
Doenças da Medula Espinal/epidemiologia , Adulto , Potenciais Evocados Visuais , Feminino , Humanos , Masculino , Mielite Transversa , Neuromielite Óptica , Doenças da Medula Espinal/etiologia , Centros de Atenção Terciária
9.
J Assoc Physicians India ; 67(8): 14-18, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31562710

RESUMO

BACKGROUND: Intracerebral Hemorrhage (ICH) is one of the most common causes of morbidity and mortality worldwide accounting for 10-15 % of all strokes types. ICH score is a validated tool to predict mortality and morbidity at 30 day follow up period. OBJECTIVE: : To prospectively evaluate the predictive utility of ICH score in patients presenting with Acute ICH on discharge,30 days and 60 days follow-up period. DESIGN: Prospective observational study. MATERIALS AND METHOD: This study was conducted in the Department of Neurology, Government Medical College, Kota, Rajasthan, India from January 2016 to August 2016. 120 consecutive patients presenting with acute ICH were studied. Data collected included demographics, clinical parameters, cranial Computed Tomography(CT) findings and ICH score on presentation. Primary outcome was defined as mortality/morbidity during hospitalisation, on discharge, 30 days and 60 days follow-up. Modified Rankin score (mRS) was used to assess the outcome. STATISTICAL ANALYSIS USED: SPSS 19 statistical software. RESULTS: Of the total 120 patients with Acute ICH(108 supratentorial and 12 infratentorial) studied, 48(40%) patients died during hospitalisation. Mean age was 66.9 ± 13.5 Years. Hydrocephalus, midline shift and IV extension on presenting CT scan was observed in 20 (16.6%), 44 (36.6%) and 48 (40%)patients respectively. The independent predictors of increased mortality with statistical significance (p<0.001) were presence of vomiting, seizures, loss of consciousness, lower GCS (≤ 8), higher ICH score and ventilator requirement. Statistically significant (p≤0.001) radiological features associated with mortality included infratentorial location, presence of hydrocephalus,higher midline shift (58.3% vs 22.2% OR=2.6), intraventricular extension of hematoma and a higher baseline hematoma volume. ICH score on admission was significantly (p<0.001) positively correlated with the mRS score on discharge (R=0.667), 1 month (R=0.66) and 2 months (R=0.765) follow-up. CONCLUSION: ICH Score is a useful tool to predict outcome during hospitalisation, on discharge, 1 month and 2 month follow-up. We suggest that ICH score assessment and documentation should become standard procedure in acute care and follow up of patients with Intracerebral Hemorrhage.


Assuntos
Hemorragia Cerebral/epidemiologia , Alta do Paciente , Idoso , Idoso de 80 Anos ou mais , Seguimentos , Humanos , Índia , Pessoa de Meia-Idade , Estudos Prospectivos
10.
Neurol India ; 66(6): 1634-1643, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30504556

RESUMO

INTRODUCTION: Our aim was to study dengue-related immune-mediated neurological complications (IMNC) during the recent epidemic. MATERIALS AND METHODS: This was a cross-sectional observational study of 79 IMNC cases from 1627 laboratory confirmed dengue cases from January 2015 to January 2016 and their follow-up for 3 months. According to the World Health Organization, cases were categorized into those having dengue fever (DF), and those having a severe syndrome that includes dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Laboratory as well as clinicoradiological data, the predictors of outcome, and the role of immunomodulation in determining the final result were analyzed. RESULTS: Out of the 1627 confirmed dengue cases, 14.6% developed neurological complications and only 4.86% cases had IMNC. Among the IMNC seen, the majority of the patients had the onset of their manifestations in the subacute (7-30 days) latency period; however, there was no mortality seen. We found Miller Fisher syndrome (MFS), limbic encephalitis, and immune-mediated cerebellar demyelination (IMCD) as the new findings in the IMNC spectrum. Patients with DF were more prone to developing brachial plexus neuritis and polyneuritis cranialis, whereas those patients with a severe syndrome were more commonly associated with Guillain-Barre syndrome (GBS). Significant (P < 0.001) predictors of central nervous system involvement were anemia, an elevated hematocrit, and the presence of DSS, whereas patients with a higher mean body temperature, DF, and elevated hematocrit were more prone to developing peripheral nervous system manifestations. The platelets counts and the hemoglobin levels had a negative correlation whereas the hematocrit value, the mean body temperature, and the alanine aminotransferase levels had a moderately significant positive correlation for the development of IMNC. The immunomodulatory therapy (IMT), if initiated after fever abatement led to a significant clinically favorable outcome at 3 months, especially in patients with GBS, polyneuritis cranialis, and brachial plexus neuritis. CONCLUSION: The spectrum of IMNC is vast and may include MFS, limbic encephalitis and IMCD. Early initiation of IMT, in the presence of significant predictors, may reduce the IMNC-related morbidity.


Assuntos
Doenças Desmielinizantes/etiologia , Dengue/complicações , Encefalite Límbica/etiologia , Síndrome de Miller Fisher/etiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Estudos Transversais , Doenças Desmielinizantes/imunologia , Dengue/imunologia , Feminino , Humanos , Imunomodulação , Encefalite Límbica/imunologia , Masculino , Pessoa de Meia-Idade , Síndrome de Miller Fisher/imunologia , Adulto Jovem
11.
12.
Int J Comput Biol Drug Des ; 3(2): 146-63, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20852338

RESUMO

Incorporating the existing knowledge of protein structural preferences, e.g., amino acid angle frequencies, in structure prediction have proven to be less successful with smaller peptides. In this work, we compare the effectiveness of backbone angle propensity libraries derived from two protein data sets: one consisting of proteins of unrestricted lengths; the second containing proteins ranging in size from 40 to 75 residues. Model structures for 29 target peptides are predicted using a threading algorithm and their stability evaluated using in vacuo molecular dynamics simulations. Structures derived from the data set consisting of smaller proteins outperformed those developed from that unrestricted by protein length.


Assuntos
Biologia Computacional/métodos , Estrutura Terciária de Proteína , Proteínas/química , Algoritmos , Sequência de Aminoácidos , Aminoácidos/química , Peptídeos/química , Estabilidade Proteica
13.
IEEE Trans Nanobioscience ; 4(3): 241-7, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16220688

RESUMO

Peptides in the skin secretion of frogs have been studied for some time now because they frequently possess important biological activity such as antibiotic, antimicrobial, or anticancer properties. In this paper, we present a computational approach for measuring the degree of similarity between the entire peptide complement of the skin secretion of specimens from the same or different species. The first step in the analysis is the generation of a mass spectral profile from an experimental high-performance liquid chromatography/electrosparay ionization analysis of the sample. An "overlap" between the mass spectral profiles of different specimens is then proposed as a measure of their similarity. Analysis of specimens from three species of the genus Litoria, viz., L. Aurea, L. Caerulea, and L. Infrafrenata, and Rana Capito of genus Rana shows that the degree of similarity is highest between specimens from the same species, lower for specimens from different species of the same genus, and lowest between specimens from different genera. This indicates that comparison of skin peptide profiles (i.e., mass spectral profiles of skin secretion) is potentially a useful aid in the taxonomic study of amphibian species.


Assuntos
Algoritmos , Anuros/classificação , Anuros/metabolismo , Perfilação da Expressão Gênica/métodos , Mapeamento de Peptídeos/métodos , Proteoma/metabolismo , Pele/metabolismo , Proteínas de Anfíbios/metabolismo , Animais , Classificação/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Especificidade da Espécie
14.
Rapid Commun Mass Spectrom ; 17(5): 429-36, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12590391

RESUMO

We propose a new algorithm for deconvolution of electrospray ionization mass spectra based on direct assignment of charge to the measured signal at each mass-to-charge ratio (m/z). We investigate two heuristics for charge assignment: the entropy-based heuristic is adapted from a deconvolution algorithm by Reinhold and Reinhold;10 the multiplicative-correlation heuristic is adapted from the multiplicative-correlation deconvolution algorithm of Hagen and Monnig.6 The entropy-based heuristic is insensitive to overestimates of z(max), the maximum ion charge. We test the deconvolution algorithm on two single-component samples: the measured spectrum of human beta-endorphin has two prominent and one very weak line whereas myoglobin has a well-developed quasi-gaussian envelope of 17 peaks. In both cases, the deconvolution algorithm gives a clean deconvoluted spectrum with one dominant peak and very few artefacts. The relative heights of the peaks due to the parent molecules in the deconvoluted spectrum of a mixture of two peptides, which are expected to ionize with equal efficiency, give an accurate measure of their relative concentration in the sample.


Assuntos
Algoritmos , Espectrometria de Massas por Ionização por Electrospray/estatística & dados numéricos , Animais , Bradicinina/análise , Capacitância Elétrica , Condutividade Elétrica , Entropia , Humanos , Íons , Mioglobina/análise , Peptídeos/química , Reprodutibilidade dos Testes , beta-Endorfina/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA