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1.
J Assoc Physicians India ; 72(6): 94-96, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38881142

RESUMO

A 38-year-old gentleman, following an uncomplicated dengue fever 2 weeks back, developed acute onset bilateral lower limb weakness and numbness for 5 days, associated with bladder and bowel incontinence and a band-like sensation in T4 dermatome. On examination, he had paraparesis with normal cranial nerves except for left upper motor neuron-type 7th cranial nerve palsy and normal higher mental function. Magnetic resonance imaging (MRI) of the brain and spine detected multiple demyelinating lesions. A diagnosis of postdengue acute disseminated encephalomyelitis (ADEM) was made as part of postinfective inflammatory process after the fever had subsided. Cerebrospinal fluid study ruled out active infection. He was treated with intravenous steroids and is currently recovering. An interesting point in our case was that the patient had significant imaging findings in MRI of the brain with no symptoms or signs suggestive of intracranial involvement-ADEM without evidence of encephalitis.


Assuntos
Dengue , Encefalomielite Aguda Disseminada , Imageamento por Ressonância Magnética , Humanos , Masculino , Encefalomielite Aguda Disseminada/diagnóstico , Encefalomielite Aguda Disseminada/tratamento farmacológico , Encefalomielite Aguda Disseminada/etiologia , Adulto , Dengue/complicações , Dengue/diagnóstico , Encéfalo/diagnóstico por imagem , Encéfalo/patologia
2.
Nanomaterials (Basel) ; 13(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36616070

RESUMO

The development of modern cutting-edge technology relies heavily on the huge success and advancement of nanotechnology, in which nanomaterials and nanostructures provide the indispensable material cornerstone. Owing to their nanoscale dimensions with possible quantum limit, nanomaterials and nanostructures possess a high surface-to-volume ratio, rich surface/interface effects, and distinct physical and chemical properties compared with their bulk counterparts, leading to the remarkably expanded horizons of their applications. Depending on their degree of spatial quantization, low-dimensional nanomaterials are generally categorized into nanoparticles (0D); nanorods, nanowires, and nanobelts (1D); and atomically thin layered materials (2D). This review article provides a comprehensive guide to low-dimensional nanomaterials and nanostructures. It begins with the classification of nanomaterials, followed by an inclusive account of nanofabrication and characterization. Both top-down and bottom-up fabrication approaches are discussed in detail. Next, various significant applications of low-dimensional nanomaterials are discussed, such as photonics, sensors, catalysis, energy storage, diverse coatings, and various bioapplications. This article would serve as a quick and facile guide for scientists and engineers working in the field of nanotechnology and nanomaterials.

3.
J Colloid Interface Sci ; 528: 156-165, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29852345

RESUMO

Coupled effects of hydrodynamics and chemical reaction during gelation process have been studied in the current work. Here, a viscous sodium alginate liquid drop impacts on calcium chloride liquid pool, chemically reacts with the pool, forms a crater, and instantaneously changes its phase from liquid to soft solid called as gel. The drop impingement height and liquid pool concentration are varied to study the effect on this process. This phenomenon is captured in a time resolved high-speed camera and the dynamics of the crater is traced using image processing technique. We also use a mathematical model for crater growth which we assume to be influenced by the rate of gelation. By validating the theoretical trend with the experimental counterpart, the gelation energy has been obtained. Scaling analysis has been executed to determine significant contributory energy in the crater growth. It is also observed that the gel swelling occurs beyond a critical concentration of calcium chloride. Also, the effect of gelation on the homogeneity and strength of alginate gel are interpreted from the surface morphology examination in scanning electron microscope. Thus a new insight of gelation process has been elucidated from the context of fluid dynamics.

4.
J Phys Chem C Nanomater Interfaces ; 115(34): 16879-16891, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21984954

RESUMO

Detection of the intrinsic fluorescence from proteins is important in bio-assays because it can potentially eliminate the labeling of external fluorophores to proteins. This is advantageous because using external fluorescent labels to tag biomolecules requires chemical modification and additional incubation and washing steps which can potentially perturb the native functionality of the biomolecules. Hence the external labeling steps add expense and complexity to bio-assays. In this paper, we investigate for the first time the feasibility of using bimetallic nanostructures made of silver (Ag) and aluminum (Al) to implement the metal enhanced fluorescence (MEF) phenomenon for enhancing the intrinsic emission of biomolecules in the ultra-violet (UV) spectral region. Fluorescence intensities and lifetimes of a tryptophan analogue N-acetyl-L-tryptophanamide (NATA) and a tyrosine analogue N-acetyl-L-tyrosinamide (NATA-tyr) were measured. Increase in fluorescence intensities of upto 10-fold and concurrent decrease in lifetimes for the amino acids were recorded in the presence of the bimetallic nanostructures when compared to quartz controls. We performed a model protein assay involving biotinylated bovine serum albumin (bt-BSA) and streptavidin on the bimetallic nanostructured substrate to investigate the distance dependent effects on the extent of MEF from the bimetallic nanostructures and found a maximum enhancement of over 15-fold for two layers of bt-BSA and streptavidin. We also used finite difference time domain (FDTD) calculations to explore how bimetallic nanostructures interact with plane waves and excited state fluorophores in the UV region and demonstrate that the bimetallic substrates are an effective platform for enhancing the intrinsic emission of proteins and other biomolecules.

5.
IEEE Trans Biomed Eng ; 57(6): 1487-96, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20172781

RESUMO

This paper presents a fully wireless cardiac pressure sensing system. Food and Drug Administration (FDA) approved medical stents are explored as radiating structures to support simultaneous transcutaneous wireless telemetry and powering. An application-specific integrated circuit (ASIC), designed and fabricated using the Texas Instruments 130-nm CMOS process, enables wireless telemetry, remote powering, voltage regulation, and processing of pressure measurements from a microelectromechanical systems (MEMS) capacitive sensor. This paper demonstrates fully wireless-pressure-sensing functionality with an external 35-dB.m RF powering source across a distance of 10 cm. Measurements in a regulated pressure chamber demonstrate the ability of the cardiac system to achieve pressure resolutions of 0.5 mmHg over a range of 0-50 mmHg using a channel data-rate of 42.2 kb/s.


Assuntos
Determinação da Pressão Arterial/instrumentação , Prótese Vascular , Próteses e Implantes , Stents , Telemetria/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
6.
J Indian Med Assoc ; 108(7): 462-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21192505

RESUMO

Mucosa associated lymphoid tissue lymphoma is a rare disease particularly when occurring in the lungs. In 1983, Issacson and Wright first described it as a distinct clinicopathological entity. A 39-year-old woman was suffering from mucosa associated lymphoid tissue lymphoma of the lung and was treated with moderate dose radiotherapy only. Six months after treatment the woman is symptom free and without any evidence of relapse. The disease undergoes a very indolent course and local form of treatment like surgery or radiotherapy is effective though radiotherapy is probably associated with higher local control rate and event free survival particularly in early stages. But for diagnostic purpose thoracotomy is generally required in pulmonary variety. Due to rarity of cases it is almost impossible to compare surgery with radiotherapy in mucosa associated lymphoid tissue lymphoma disorder in a prospective manner. Radiotherapy is the preferred mode of treatment either alone or in combination with surgery.


Assuntos
Neoplasias Pulmonares/radioterapia , Linfoma de Zona Marginal Tipo Células B/radioterapia , Adulto , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico , Linfoma de Zona Marginal Tipo Células B/diagnóstico
8.
Anal Bioanal Chem ; 381(2): 347-53, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15558247

RESUMO

Despite the importance of accurately determining inorganic arsenic speciation in natural waters to predicting bioavailability and environmental and health impacts, there remains considerable debate about the most appropriate species preservation strategies to adopt. In particular, the high-iron, low-Eh (redox potential) shallow groundwaters in West Bengal, Bangladesh and SE Asia, the use of which for drinking and irrigation purposes has led to massive international concerns for human health, are particularly prone to changes in arsenic speciation after sampling. The effectiveness of HCl and EDTA preservation strategies has been compared and used on variably arsenic-rich West Bengali groundwater samples, analysed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). Immediate filtration and acidification with HCl followed by refrigerated storage was found to be the most effective strategy for minimizing the oxidation of inorganic As(III) during storage. The use of a PRP-X100 (Hamilton) column with a 20 mmol L(-1) NH4H2PO4 as mobile phase enabled the separation of Cl- from As(III), monomethylarsonic acid, dimethylarsinic acid and As(V), thereby eliminating any isobaric interference between 40Ar35Cl+ and 75As+. The use of EDTA as a preservative, whose action is impaired by the high calcium concentrations typical of these types of groundwater, resulted in marked oxidation during storage. The use of HCl is therefore indicated for analytical methods in which chloride-rich matrices are not problematical. The groundwaters analysed by IC-ICP-MS were found to contain between 5 and 770 ng As mL(-1) exclusively as inorganic arsenic species. As(III)/total-As varied between 0 and 0.94.

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