Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
1.
Indian J Cancer ; 60(2): 191-198, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37530240

RESUMO

Background: Diagnosis of hepatocellular carcinoma (HCC) is difficult on morphology alone in poorly differentiated tumors and metastatic carcinomas. Appropriate immunohistochemical markers are required for definite diagnosis. In this article, we have analyzed the histopathological and immunohistochemical features of HCC and elucidate the best possible immunohistochemistry (IHC) marker combination by comparing the sensitivity of various markers in different grades of tumor. Methods: A total of 116 consecutive cases were analyzed retrospectively. The hematoxylin and eosin stained sections were reviewed in all the cases. IHC was done using hepatocellular specific antigen (HSA), arginase-1, glypican-3, and polyclonal carcinoembryonic antigen (pCEA). The sensitivity of various immunohistochemical markers individually as well as in combination for different tumor grades was determined. Results: Histologically, the predominant subtype comprised of classic variant (109,93.9%) followed by combined hepatocellular and cholangiocarcinoma (4,3.4%) and fibrolamellar variant (3,2.6%). Trabecular pattern was the most common histological pattern. On grading, 65,56.03% were moderately differentiated, 34,29.31% well differentiated, and17, 14.65% poorly differentiated. HSA and polyclonal-CEA showed higher sensitivity than arginase-1 and glypican-3 in well and moderately differentiated tumors. In contrast arginase-1 and glypican-3 showed better sensitivity in poorly differentiated HCC. The overall sensitivity increased to greater than 90% if HSA/polyclonal-CEA is combined with either arginase-1/glypican-3 irrespective of tumor grade. Conclusion: Majority of the tumors were classic variants and moderately differentiated. HSA along with either arginase-1 or glypican-3 is the best combination of immunomarker for identification of hepatocellular differentiation irrespective of tumor grade.


Assuntos
Neoplasias dos Ductos Biliares , Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Antígeno Carcinoembrionário , Glipicanas , Arginase , Estudos Retrospectivos , Centros de Atenção Terciária , Biomarcadores Tumorais , Ductos Biliares Intra-Hepáticos/patologia , Diagnóstico Diferencial
2.
Int J Inf Technol ; 14(4): 2231-2240, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35493719

RESUMO

This paper presents financial time series forecasting with multistage wavelet transform (WT). First, the time series data is processed through WT with different mother wavelet functions to extract high frequency and low frequency coefficients. Later, standard particle swarm optimization (PSO) algorithm is utilized to find optimal regression models in order to predict future samples. Mean square error (MSE) is opted as cost function for PSO to find optimal coefficients of the regression model. This study further extended to various mother wavelet functions and their decomposition levels to investigate their impacts on time series prediction. These investigations help to data scientists for selection of process parameters and variables. Further, the impact of control parameters of PSO is also discussed to show the importance in the search mechanism especially in regression problems.

3.
PLoS One ; 16(2): e0247115, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33596239

RESUMO

The rapid emergence of coronavirus disease 2019 (COVID-19) as a global pandemic affecting millions of individuals globally has necessitated sensitive and high-throughput approaches for the diagnosis, surveillance, and determining the genetic epidemiology of SARS-CoV-2. In the present study, we used the COVIDSeq protocol, which involves multiplex-PCR, barcoding, and sequencing of samples for high-throughput detection and deciphering the genetic epidemiology of SARS-CoV-2. We used the approach on 752 clinical samples in duplicates, amounting to a total of 1536 samples which could be sequenced on a single S4 sequencing flow cell on NovaSeq 6000. Our analysis suggests a high concordance between technical duplicates and a high concordance of detection of SARS-CoV-2 between the COVIDSeq as well as RT-PCR approaches. An in-depth analysis revealed a total of six samples in which COVIDSeq detected SARS-CoV-2 in high confidence which were negative in RT-PCR. Additionally, the assay could detect SARS-CoV-2 in 21 samples and 16 samples which were classified inconclusive and pan-sarbeco positive respectively suggesting that COVIDSeq could be used as a confirmatory test. The sequencing approach also enabled insights into the evolution and genetic epidemiology of the SARS-CoV-2 samples. The samples were classified into a total of 3 clades. This study reports two lineages B.1.112 and B.1.99 for the first time in India. This study also revealed 1,143 unique single nucleotide variants and added a total of 73 novel variants identified for the first time. To the best of our knowledge, this is the first report of the COVIDSeq approach for detection and genetic epidemiology of SARS-CoV-2. Our analysis suggests that COVIDSeq could be a potential high sensitivity assay for the detection of SARS-CoV-2, with an additional advantage of enabling the genetic epidemiology of SARS-CoV-2.


Assuntos
COVID-19/epidemiologia , COVID-19/virologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , COVID-19/genética , Genoma Viral/genética , Humanos , Índia/epidemiologia , Epidemiologia Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Pandemias , Filogenia , RNA Viral/genética , RNA Viral/isolamento & purificação , Sensibilidade e Especificidade
4.
Neuroimage ; 199: 289-303, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31141736

RESUMO

Inhomogeneous Magnetization Transfer (ihMT) is a development from the MT MRI technique. IhMT can be considered as a dipolar order relaxation time (T1D) weighted imaging modality whose signal has shown an enhanced selectivity for myelin-rich structures. However, a formal validation of the ihMT sensitivity relative to a gold standard myelin density measurement has not yet been reported. To address this need, we compared ihMT MRI with green fluorescence protein (GFP) microscopy, in a study performed on genetically-modified plp-GFP mice, considered as a reference technique for myelin-content assessment. Various ihMT protocols consisting of variable T1D-filtering and radiofrequency power temporal distributions, were used for comparison with fluorescence microscopy. Strong and significant linear relationships (r2 (0.87-0.96), p < 0.0001) were found between GFP and ihMT ratio signals across brain regions for all tested protocol variants. Conventional MT ratios showed weaker correlations (r2 (0.24-0.78), p ≤ 0.02) and a much larger signal fraction unrelated to myelin, hence corresponding to a much lower specificity for myelin. T1D-filtering reduced the ihMT signal fraction not attributed to myelin by almost twofold relative to zero filtering suggesting that at least half of the unrelated signal has a substantially shorter T1D than myelin. Overall, these results strongly support the sensitivity of ihMT to myelin content.


Assuntos
Substância Cinzenta/diagnóstico por imagem , Imageamento por Ressonância Magnética/normas , Microscopia de Fluorescência/normas , Bainha de Mielina , Substância Branca/diagnóstico por imagem , Animais , Interpretação Estatística de Dados , Imageamento por Ressonância Magnética/métodos , Camundongos , Camundongos Endogâmicos C57BL , Sensibilidade e Especificidade
5.
Sci Rep ; 9(1): 1406, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30723229

RESUMO

Plants have an amazing ability to cope with wide variety of stresses by regulating the expression of genes and thus by altering the physiological status. In the past few years, canonical microRNA variants (isomiRs) have been shown to play pivotal roles by acting as regulators of the transcriptional machinery. In the present research, we present Diff isomiRs, a web-based exploratory repository of differential isomiRs across 16 sequenced plant species representing a total of 433 datasets across 21 different stresses and 158 experimental states. Diff isomiRs provides the high-throughput detection of differential isomiRs using mapping-based and model-based differential analysis revealing a total of 16,157 and 2,028 differential isomiRs, respectively. Easy-to-use and web-based exploration of differential isomiRs provides several features such as browsing of the differential isomiRs according to stress or species, as well as association of the differential isomiRs to targets and plant endogenous target mimics (PeTMs). Diff isomiRs also provides the relationship between the canonical miRNAs, isomiRs and the miRNA-target interactions. This is the first web-based large-scale repository for browsing differential isomiRs and will facilitate better understanding of the regulatory role of the isomiRs with respect to the canonical microRNAs. Diff isomiRs can be accessed at: www.mcr.org.in/diffisomirs .


Assuntos
Sequência de Bases/genética , Variação Genética , Genoma de Planta/genética , MicroRNAs/genética , Plantas/genética , Estresse Fisiológico/genética , Bases de Dados Genéticas , Regulação da Expressão Gênica de Plantas , Sequenciamento de Nucleotídeos em Larga Escala , RNA-Seq , Navegador
6.
J Magn Reson ; 296: 60-71, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30212729

RESUMO

Intense off-resonant RF irradiation can lead to saturation of the macromolecular pool magnetization and enhance bound pool dipolar order responsible for the inhomogeneous magnetization transfer (ihMT) effect, but the intensity of RF power in human imaging studies is limited by safety constraints on RF heating. High RF intensities can still be achieved if applied in short pulses with low duty-cycle. Here we investigate the benefits of low duty-cycle irradiation for MT and ihMT studies with both theoretical and experimental methods. Solutions for pulsed irradiation of a two-pool model including dipolar order effects were implemented. Experiments were conducted at 3 T in the brain and through the calf of healthy human subjects. 2D echo planar images were acquired following a preparation of RF irradiation with a 2 s train of 5 ms pulses repeated from between 10 to 100 ms for duty-cycles (DCs) of 50% to 5%, and at varying offset frequencies, and time averaged RF powers. MT and ihMT data were measured in regions of interest within gray matter, white matter and muscle, and fit to the model. RF irradiation effects on signal intensity were reduced at 5% relative to 50% DCs. This reduced RF effect was much larger for single than dual frequency irradiation. 5% DC irradiation reduced single and dual frequency MT ratios but increased ihMT ratios up to 3 fold in brain tissues. Muscle ihMT increased by an even larger factor, depending on the frequency and applied power. The model predicted these changes with duty-cycle. The model fit the data well and constrained model parameters. Low duty-cycle pulsed irradiation reduces MT effects and markedly increases dipolar order effects. This approach is an attractive method to enhance ihMT signal-to-noise ratio and demonstrates a measurable ihMT effect in muscle tissue at 3 T under acceptable specific absorption rates. The effects of duty-cycle changes demonstrated in a separate MT/ihMT preparation provide a route for new applications in magnetization-prepared MRI sequences.

7.
Opt Express ; 26(7): 8679-8689, 2018 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-29715832

RESUMO

In this paper an optimal power allocation scheme is proposed to acheive uniform illuminance. Regular arrays and random geometries are considered for an arrangement of the source LEDs. Uniform illuminance is accomplished by considering the variance of the received power on the receiver plane as metric and framing it as a convex optimization problem. Numerical results show that the quality factor of random geometries are superior to fixed geometries. While preserving uniformity, the cost of the system can be reduced when random geometries are used.

8.
AJNR Am J Neuroradiol ; 39(4): 634-641, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29472299

RESUMO

BACKGROUND AND PURPOSE: Inhomogeneous magnetization transfer is a new endogenous MR imaging contrast mechanism that has demonstrated high specificity for myelin. Here, we tested the hypothesis that inhomogeneous magnetization transfer is sensitive to pathology in a population of patients with relapsing-remitting MS in a way that both differs from and complements conventional magnetization transfer. MATERIALS AND METHODS: Twenty-five patients with relapsing-remitting MS and 20 healthy volunteers were enrolled in a prospective MR imaging research study, whose protocol included anatomic imaging, standard magnetization transfer, and inhomogeneous magnetization transfer imaging. Magnetization transfer and inhomogeneous magnetization transfer ratios measured in normal-appearing brain tissue and in MS lesions of patients were compared with values measured in control subjects. The potential association of inhomogeneous magnetization transfer ratio variations with the clinical scores (Expanded Disability Status Scale) of patients was further evaluated. RESULTS: The magnetization transfer ratio and inhomogeneous magnetization transfer ratio measured in the thalami and frontal, occipital, and temporal WM of patients with MS were lower compared with those of controls (P < .05). The mean inhomogeneous magnetization transfer ratio measured in lesions was lower than that in normal-appearing WM (P < .05). Significant (P < .05) negative correlations were found between the clinical scores and inhomogeneous magnetization transfer ratio measured in normal-appearing WM structures. Weaker nonsignificant correlation trends were found for the magnetization transfer ratio. CONCLUSIONS: The sensitivity of the inhomogeneous magnetization transfer technique for MS was highlighted by the reduction in the inhomogeneous magnetization transfer ratio in MS lesions and in normal-appearing WM of patients compared with controls. Stronger correlations with the Expanded Disability Status Scale score were obtained with the inhomogeneous magnetization transfer ratio compared with the standard magnetization transfer ratio, which may be explained by the higher specificity of inhomogeneous magnetization transfer for myelin.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Esclerose Múltipla Recidivante-Remitente/patologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Estudos Prospectivos , Sensibilidade e Especificidade
9.
Methods Mol Biol ; 1667: 195-201, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29039013

RESUMO

Molecular markers play an important role in identifying the species variation, characterizing the genic diversity, and also linking the identified markers to trait of interest. Genome- and transcriptome-derived molecular markers have been widely used to understand the geographical diversity and have also played a major role in the development of high-density linkage maps. In the present protocol, we present a detailed protocol on bioinformatics approaches towards the whole-genome and transcriptome-assisted simple sequence repeats (SSRs) marker mining in Brachypodium distachyon and identification of orthologus SSRs and their validation in Brachypodium ecotypes. We also present a protocol for the validation of the identified markers.


Assuntos
Brachypodium/genética , Genoma de Planta , Genômica/métodos , Repetições de Microssatélites , Transcriptoma , Mapeamento Cromossômico/métodos , Cromossomos de Plantas/genética , Ligação Genética , Software
10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2017: 2239-2242, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29060342

RESUMO

Beamforming is a spatial filtering technique used in hearing aids to improve target sound reception by reducing interference from other directions. In this paper we propose improvements in an existing architecture present for two omnidirectional microphone array based adaptive beamforming for hearing aid applications and implement the same on Xilinx Artix 7 FPGA using VHDL coding and Xilinx Vivado® 2015.2. The nulls are introduced in particular directions by combination of two fixed polar patterns. This combination can be adaptively controlled to steer the null in the direction of noise. The beamform patterns and improvements in SNR values obtained from experiments in a conference room environment are analyzed.


Assuntos
Auxiliares de Audição , Desenho de Equipamento , Ruído , Percepção da Fala
11.
Neurotoxicology ; 62: 207-217, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28712943

RESUMO

Developmental exposure to prenatal stress (PS) and lead (Pb) can affect brain development and adversely influence behavior and cognition. Epigenetic-based gene regulation is crucial for normal brain development and mis-regulation, in any form, can result in neurodevelopmental disorders. Post-translational histone modifications (PTHMs) are an integral and dynamic component of the epigenetic machinery involved in gene regulation. Exposures to Pb and/or PS may alter PTHM profiles, promoting lifelong alterations in brain function observed following Pb±PS exposure. Here we examined the effects of Pb±PS on global levels of activating marks H3K9Ac and H3K4Me3 and repressive marks H3K9Me2 and H3K27Me3 at different developmental stages: E18, PND0, PND6 and PND60. Dams were exposed to 0 or 100ppm Pb beginning 2 months prior to breeding followed by no PS (NS) or PS resulting in 4 offspring treatment groups per sex: 0-NS (control), 0-PS, 100-NS and 100-PS. Global levels of PTHMs varied from E18 through adulthood even in control mice, and were influenced by sex and brain-region. The developmental trajectory of these PTHM levels was further modified by Pb±PS in a sex-, brain region- and age-dependent manner. Females showed a preferential response to Pb alone in frontal cortex (FC) and differentially to PS alone and combined Pb+PS in hippocampus (HIPP). In males, PS-induced increases in PTHM levels in FC, whereas PS produced reductions in HIPP. Pb±PS-based changes in PTHM levels continued to be observed in adulthood (PND60), demonstrating the lasting effect of these early life environmental events on these histone marks. These results indicate that epigenetic consequences of Pb±PS and their contribution to mechanisms of toxicity are sex dependent. Additional studies will assist in understanding the functional significance of these changes in PTHM levels on expression of individual genes, functional pathways, and ultimately, their behavioral consequences.


Assuntos
Encéfalo , Histonas/metabolismo , Chumbo/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Caracteres Sexuais , Estresse Psicológico/fisiopatologia , Animais , Animais Recém-Nascidos , Encéfalo/efeitos dos fármacos , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Embrião de Mamíferos , Feminino , Código das Histonas/efeitos dos fármacos , Masculino , Camundongos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Processamento de Proteína Pós-Traducional/fisiologia , Restrição Física/efeitos adversos
12.
Opt Express ; 25(8): 8659-8669, 2017 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-28437943

RESUMO

In this paper, a simple heuristic power allocation scheme is proposed for a random LED array to obtain uniform irradiance on the projection surface. This is done by considering a binomial point process (BPP) for modeling the LED location and using the quality factor as a performance metric. Numerical results are provided to validate the proposed model and demonstrate its simplicity over existing LED geometries.

13.
NMR Biomed ; 30(6)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28195663

RESUMO

A pulsed inhomogeneous magnetization transfer (ihMT)-prepared fast imaging sequence was implemented at 11.75 T for preclinical studies on mouse central nervous system. A strategy based on filtering the ihMT signal originating from short dipolar relaxation time (T1D ) components is proposed. It involves increasing the repetition time of consecutive radiofrequency (RF) pulses of the dual saturation and allows improved signal specificity for long T1D myelinated structures. Furthermore, frequency offset, power and timing saturation parameters were adjusted to optimize the ihMT sensitivity. The optimization of the ihMT sensitivity, whilst preserving the strong specificity for the long T1D component of myelinated tissues, allowed measurements of ihMT ratios on the order of 4-5% in white matter (WM), 2.5% in gray matter (GM) and 1-1.3% in muscle. This led to high relative ihMT contrasts between myelinated tissues and others (~3-4 between WM and muscle, and ≥2 between GM and muscle). Conversely, higher ihMT ratios (~6-7% in WM) could be obtained using minimal T1D filtering achieved with short saturation pulse repetition time or cosine-modulated pulses for the dual-frequency saturation. This study represents a first stage in the process of validating ihMT as a myelin biomarker by providing optimized ihMT preclinical sequences, directly transposable and applicable to other preclinical magnetic fields and scanners. Finally, ihMT ratios measured in various central nervous system areas are provided for future reference.


Assuntos
Meios de Contraste/química , Imageamento por Ressonância Magnética/métodos , Animais , Sistema Nervoso Central/anatomia & histologia , Feminino , Processamento de Imagem Assistida por Computador , Camundongos Endogâmicos C57BL , Fatores de Tempo
14.
Curr Opin Toxicol ; 6: 60-70, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29430559

RESUMO

Over a lifetime, early developmental exposures to neurocognitive risk factors, such as lead (Pb) exposures and prenatal stress (PS), will be followed by multiple varied behavioral experiences. Pb, PS and behavioral experience can each influence brain epigenetic profiles. Our recent studies show a greater level of complexity, however, as all three factors interact within each sex to generate differential adult variation in global post-translational histone modifications (PTHMs), which may result in fundamentally different consequences for life-long learning and behavioral function. We have reported that PTHM profiles differ by sex, brain region and time point of measurement following developmental exposures to Pb±PS, resulting in different profiles for each unique combination of these parameters. Imposing differing behavioral experience following developmental Pb±PS results in additional divergence of PTHM profiles, again in a sex, brain region and time-dependent manner, further increasing complexity. Such findings underscore the need to link highly localized and variable epigenetic changes along single genes to the highly-integrated brain functional connectome that is ultimately responsible for governing behavioral function. Here we advance the idea that increased understanding may be achieved through iterative reductionist and holistic approaches. Implications for experimental design of animal studies of developmental exposures to neurotoxicants include the necessity of a 'no behavioral experience' group, given that epigenetic changes in response to behavioral testing can confound effects of the neurotoxicant itself. They also suggest the potential utility of the inclusion of salient behavioral experiences as a potential effect modifier in epidemiological studies.

15.
J Magn Reson ; 260: 67-76, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26408956

RESUMO

Comparison of off-resonance saturation with single and dual frequency irradiation indicates a contribution of inhomogeneously broadened lines to magnetization transfer in tissues. This inhomogeneous magnetization transfer (ihMT) phenomenon can be exploited to produce images that highlight tissues containing myelin, in vivo. Here, a model for ihMT is described that includes dipolar order effects from magnetization associated with motion-restricted macromolecules. In this model, equal irradiation at positive and negative frequency offsets eliminates dipolar order and achieves greater saturation than irradiation at a single offset frequency using the same power. Fitting of mouse and human volunteer brain data at different irradiation powers and offset frequencies was performed to assess the relevance of the model and approximate tissue parameters. A key parameter in determining ihMT signal was found to be the relaxation time T1D associated with the dipolar order reservoir and the fraction f of the semi-solid, bound magnetization that possessed a nonzero T1D. Indeed, better fits of myelinated tissue were achieved when assuming f≠1. From such fits, estimated T1Ds of mice in the white matter, (34±14) ms, were much longer than in muscle, T1D=(1±1) ms and the average f from white matter volunteer data was 2.2 times greater than that in grey matter. The combination of f and longer T1Ds was primarily responsible for the much higher ihMT in myelinated tissues, and provided explanation for the species variation. This dipolar order ihMT model should help guide future research, pulse sequence optimization, and clinical applications.


Assuntos
Imageamento por Ressonância Magnética/métodos , Adulto , Algoritmos , Animais , Encéfalo/anatomia & histologia , Simulação por Computador , Feminino , Substância Cinzenta/anatomia & histologia , Humanos , Processamento de Imagem Assistida por Computador , Substâncias Macromoleculares/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Neurológicos , Músculo Esquelético/anatomia & histologia , Bainha de Mielina/ultraestrutura , Especificidade da Espécie , Substância Branca/anatomia & histologia
16.
Dalton Trans ; 43(15): 5713-20, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24557454

RESUMO

Here, we report the facile synthesis of a highly ordered luminescent ZnO nanowire array using a low temperature anodic aluminium oxide (AAO) template route which can be economically produced in large scale quantity. The as-synthesized nanowires have diameters ranging from 60 to 70 nm and length ∼11 µm. The photoluminescence spectrum reveals that the AAO/ZnO assembly has a strong green emission peak at 490 nm upon excitation at a wavelength of 406 nm. Furthermore, the ZnO nanowire array-based gas sensor has been fabricated by a simple micromechanical technique and its NH3 gas sensing properties have been explored thoroughly. The fabricated gas sensor exhibits excellent sensitivity and fast response to NH3 gas at room temperature. Moreover, for 50 ppm NH3 concentration, the observed value of sensitivity is around 68%, while the response and recovery times are 28 and 29 seconds, respectively. The present synthesis technique to produce a highly ordered ZnO nanowire array and a fabricated gas sensor has great potential to push the low cost gas sensing nanotechnology.


Assuntos
Óxido de Alumínio/química , Amônia/análise , Nanofios/química , Óxido de Zinco/química , Luminescência , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanofios/ultraestrutura
17.
Magn Reson Med ; 68(4): 1228-33, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22246655

RESUMO

The keyhole technique, which involves the acquisition of dynamic data at low resolution in combination with a high-resolution reference, is developed for the purposes of chemical exchange saturation transfer (CEST) imaging, i.e., Keyhole CEST. Low-resolution data are acquired with saturation applied at different frequencies for Z-spectra, along with a high-resolution reference image taken without saturation. Three methods for high-resolution reconstruction of Keyhole CEST are evaluated using the values from quantitative high-resolution CEST maps. In addition, Keyhole CEST is applied for collection of data used for B(0) correction. The keyhole approach is evaluated for CEST contrast generation using exchanging protons in hydroxyl groups. First, the techniques are evaluated in vitro using samples of dextrose and chondroitin sulfate. Next, the work is extended in vivo to explore its applicability for gagCEST. Comparable quantitative gagCEST values are found using Keyhole CEST, provided the structure or region of interest is not limited by the low-resolution dataset.


Assuntos
Algoritmos , Cartilagem/anatomia & histologia , Cartilagem/química , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Imagem Molecular/métodos , Adulto , Animais , Bovinos , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
18.
Climacteric ; 14(2): 275-81, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21226659

RESUMO

OBJECTIVE: To investigate the effects of hysterectomy and/or oophorectomy on sexual satisfaction. METHODS: Forty sexually active women underwent a hysterectomy and/or oophorectomy, for benign gynecological diseases. Patients were interviewed 15 days prior to their operation and again in the 3rd and 6th months after the surgical procedure. Depressive symptoms, anxiety symptoms and sexual satisfaction were measured by the Hamilton Depression Rating Scale, the Hamilton Anxiety Scale and the Golombock Rust Inventory of Sexual Satisfaction (GRISS), respectively. Repeated-measures analyses of variance (ANOVA) examined alterations in anxiety, depression and sexual satisfaction. Independent t-test and Mann-Whitney U tests compared the numerical data. RESULTS: The women had mild depressive symptoms before the surgery; however, these symptoms lessened between 3 and 6 months after the surgery. Similarly, the level of anxiety symptoms decreased during the postoperative period. Based on the GRISS cut-off point, it was found that the patients had problems in the sub-dimensions of frequency, communication, and avoidance in the pre-operative period. This pre-existing sexual dissatisfaction continued after the surgery, and sensuality and anorgasmia problems increased. Satisfaction, sensuality, avoidance and anorgasmia GRISS scores were significantly higher after the operation than before. Therefore, the patients' sexual satisfaction was decreased after the operation. CONCLUSIONS: Patients were dissatisfied with frequency and communication, and they had high levels of avoidance before operation. In the postoperative period, sexual dissatisfaction increased. Although depression and anxiety decreased after the operation, we found that hysterectomy and/or oophorectomy had negative effects on sexual satisfaction.


Assuntos
Ansiedade/etiologia , Depressão/etiologia , Histerectomia , Ovariectomia , Complicações Pós-Operatórias , Disfunções Sexuais Psicogênicas/etiologia , Feminino , Humanos , Satisfação Pessoal , Psicometria , Comportamento Sexual
19.
Z Gerontol Geriatr ; 43(4): 259-63, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19806290

RESUMO

The present investigation aimed to assess the health-related QoL (HRQoL) of elderly people living in two settings: (i) rural community and (ii) homes for the elderly in a district of South India. The data are drawn from elderly (>60 years of age) sampled from both settings. The short form 36-item health survey (SF-36) was administered to all respondents. The average scores for several domains, including total physical health, total mental health and overall health (total SF-36 score) were around 50, which can be interpreted as a moderate level of health-related QoL. Residents living in a home for the elderly scored better in all domains except for role-physical and role-emotional. Though univariate analysis revealed some associations between characteristics of elderly SF-36 scores, the multiple regression analysis indicated that working status yields a significant but negative coefficient for total SF-36 score among community dwelling elderly. The elderly report that their lives are better when they are staying in homes for the elderly. Hence, despite the socio-economic conditions, provision of a better and conducive environment by setting up more charity-based homes for the elderly may be one of the options for relative betterment of the QoL of the elderly, particularly those who are socially and economically deprived. Finally, the study warrants the need of normative values of SF-36 for various population groups in India.


Assuntos
Cuidadores/psicologia , Países em Desenvolvimento , Instituição de Longa Permanência para Idosos , Casas de Saúde , Qualidade de Vida/psicologia , População Rural , Idoso , Avaliação da Deficiência , Feminino , Avaliação Geriátrica , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Dinâmica Populacional , Mudança Social , Identificação Social , Valores Sociais , Fatores Socioeconômicos
20.
J Phys Condens Matter ; 21(29): 296001, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21828540

RESUMO

We report on the effect of Sb co-doping on the structural and magnetic properties of bulk ZnMnO samples. Samples with nominal compositions Zn(0.98-y)Mn(0.02)Sb(y)O (y = 0, 0.01 and 0.03) were synthesized using a solid state reaction route at 800 °C. X-ray diffraction (XRD) results reveal wurtzite structure of pure ZnO without any impurity phases for compositions y = 0.0 and 0.01. On the other hand, a weak diffraction peak corresponding to the impurity phase Zn/MnSb(2)O(6) was detected in the XRD pattern of composition y = 0.03. Energy dispersive x-ray (EDAX) results confirm the presence of all elements in the samples in the stoichiometric ratio. The M-H curve of the pure ZnMnO sample shows paramagnetic behavior, whereas M-H curves of Sb co-doped samples show room temperature ferromagnetism (RTFM) with saturated loops. Saturation magnetization (M(S)) and coercive field (H(C)) both increase with the increase in Sb doping percentage. Inverse susceptibility (1/χ) versus temperature (T) curves suggests dominant antiferromagnetic interactions in the samples which decrease with the co-doping of Sb. Based on the experimental results we conclude that the observed RTFM in Sb co-doped ZnMnO is due to defects induced by strain.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...