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3.
Faraday Discuss ; 217: 8-33, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31094388

RESUMO

This introduction provides a historical context for the development of ion spectroscopy over the past half century by following the evolution of experimental methods to the present state-of-the-art. Rather than attempt a comprehensive review, we focus on how early work on small ions, carried out with fluorescence, direct absorption, and photoelectron spectroscopy, evolved into powerful technologies that can now address complex chemical problems ranging from catalysis to biophysics. One of these developments is the incorporation of cooling and temperature control to enable the general application of "messenger tagging" vibrational spectroscopy, first carried out using ionized supersonic jets and then with buffer gas cooling in radiofrequency ion traps. Some key advances in the application of time-resolved pump-probe techniques to follow ultrafast dynamics are also discussed, as are significant benchmarks in the refinement of ion mobility to allow spectroscopic investigation of large biopolymers with well-defined shapes. We close with a few remarks on challenges and opportunities to explore molecular level mechanics that drive macroscopic behavior.


Assuntos
Fenômenos Astronômicos , Biopolímeros/análise , Física , Análise Espectral/tendências , Biologia , Análise Espectral/instrumentação
5.
An Acad Bras Cienc ; 91(suppl 1): e20180294, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31017188

RESUMO

Green Analytical Chemistry (GAC) is a research field that seeks for more sustainable analytical approaches to minimize the toxicity and amounts of wastes without hindering the analytical performance. This is a trend in Analytical Chemistry worldwide and because of the diversity of innovations on this subject, Brazil stands out as the third in the list of the main contributors to GAC, with ca. 11.2% of the published articles. Significant innovations and interesting applications in several fields have been presented and Brazil is continuously moving from Chemistry to Green Chemistry also in the Analytical Chemistry field. Selected contributions for sample preparation, spectro- and electroanalysis, separation techniques, chemometrics, and also procedures for point-of-care measurements are critically reviewed.


Assuntos
Técnicas de Química Analítica/tendências , Química Verde/tendências , Pesquisa/tendências , Brasil , Técnicas de Química Analítica/métodos , Química Verde/métodos , Humanos , Microextração em Fase Líquida/métodos , Microextração em Fase Líquida/tendências , Microextração em Fase Sólida/métodos , Microextração em Fase Sólida/tendências , Solventes , Análise Espectral/métodos , Análise Espectral/tendências
6.
Annu Rev Phys Chem ; 70: 199-218, 2019 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-30883272

RESUMO

Understanding the cellular basis of human health and disease requires the spatial resolution of microscopy and the molecular-level details provided by spectroscopy. This review highlights imaging methods at the intersection of microscopy and spectroscopy with applications in cell biology. Imaging methods are divided into three broad categories: fluorescence microscopy, label-free approaches, and imaging tools that can be applied to multiple imaging modalities. Just as these imaging methods allow researchers to address new biological questions, progress in biological sciences will drive the development of new imaging methods. We highlight four topics in cell biology that illustrate the need for new imaging tools: nanoparticle-cell interactions, intracellular redox chemistry, neuroscience, and the increasing use of spheroids and organoids. Overall, our goal is to provide a brief overview of individual imaging methods and highlight recent advances in the use of microscopy for cell biology.


Assuntos
Biologia Celular/tendências , Técnicas Citológicas/métodos , Microscopia/métodos , Animais , Técnicas Citológicas/tendências , Humanos , Microscopia/tendências , Espalhamento de Radiação , Análise Espectral/métodos , Análise Espectral/tendências
7.
Acc Chem Res ; 51(9): 2279-2286, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30152675

RESUMO

In 1998, the first successful quantum control experiment with application to a molecular framework was conducted with a shaped laser pulse, optimizing the branching ratio between different organometallic reaction channels. This work induced a vast activity in quantum control during the next 10 years, and different optimization aims were achieved in the gas phase, liquid phase, and even in biologically relevant molecules like light-harvesting complexes. Accompanying and preceding this development were important advances in theoretical quantum control simulations. They predicted several control scenarios and explained how and why quantum control experiments work. After many successful proofs of concept in molecular science, the big challenge is to expand its huge conceptual potential of directly being able to steer nuclear and/or electronic motion to more applied implementations. In this Account, based on several recent advances, we give a personal evaluation of where the field of molecular quantum control is at the moment and especially where we think promising applications can be in the near future. One of these paths leads to synthetic chemistry. The synthesis of novel pharmaceutical compounds or natural products often involves many synthetic steps, each one devouring resources and lowering the product yield. Shaped laser pulses can possibly act as photonic reagents and shorten the synthetic route toward the desired product. Chemical synthesis usually takes place in solution, and by including explicit solvent molecules in our quantum control simulations, we were able to identify their highly inhomogeneous influence on chemical reactions and how this affects potential quantum control. More important, we demonstrated for a synthetically relevant example that these complications can be overcome in theory, and laser pulses can be optimized to initiate the desired carbon-carbon bond formation. Putting this into context with the recently emerging concept of flow chemistry, which brings several practical advantages to the application of laser pulses, we want to encourage experimental groups to exploit this concept. Another path was opened by several additions to the commonly used laser pulse optimization algorithm (optimal control theory, OCT), several of which were developed in our group. The OCT algorithm as such is a purely mathematical optimization procedure, with no direct relation to experimental requirements. This means that usually the electric fields obtained out of OCT optimizations do not resemble laser pulses that can be achieved experimentally. However, the previously mentioned additions are aimed at closing the gap toward the experiment. In a recent quantum control study of our group, these algorithmic developments came to fruition. We were able to suggest a shaped laser pulse which can induce a long-living wave packet in the excited state of uracil. This might pave the way for novel experiments dedicated to investigating the formation of biological photodamage in DNA and RNA. The pulse we suggest is surprisingly simple because of the extended OCT algorithm and fulfills all criteria to be experimentally accessible.


Assuntos
Técnicas de Química Sintética/tendências , Teoria Quântica , Análise Espectral/tendências , Algoritmos , Técnicas de Química Sintética/métodos , Lasers , Luz , Análise Espectral/métodos , Vibração
8.
Arq. bras. med. vet. zootec. (Online) ; 70(2): 597-605, mar.-abr. 2018. tab, graf
Artigo em Português | LILACS, VETINDEX | ID: biblio-910879

RESUMO

O presente trabalho teve como objetivo validar a eficácia do método de espectroscopia de reflectância do infravermelho proximal (NIRS) em predizer o consumo e a digestibilidade da MS e nutrientes de dietas para cordeiros confinados, em comparação ao método convencional de laboratório. Amostras das dietas fornecidas, sobras e fezes de 40 cordeiros Santa Inês foram submetidas a ambos os métodos e analisadas quanto aos teores de MS, MM, FDN, FDA, PB e EE, para futuros cálculos do consumo e da digestibilidade. A maioria dos coeficientes de correlação do modelo ficou na faixa de 0,66 a 0,81, mostrando-se adequados para a predição quantitativa. Os maiores coeficientes foram observados para teores de PB das dietas (0,85) e sobras (0,87). Foram encontradas altas correlações entre os métodos na predição do consumo (média de 0,93) e digestibilidade (média de 0,90) das dietas. As correlações entre as variáveis obtidas pela predição do NIRS e pelo método convencional foram adequadas, demonstrando que, independentemente do método, os teores nutricionais das dietas, das sobras e das fezes podem ser utilizados para calcular o consumo e a digestibilidade da MS e dos nutrientes das dietas para cordeiros confinados, sendo recomendado o método NIRS pela precisão, pela rapidez e pelo baixo custo em relação ao método convencional.(AU)


This research was carried out to validate the effectiveness of the Near-IR spectroscopy method in predicting intake and digestibility of DM and nutrients of diets for feedlot lambs, in order to compare with the conventional laboratory method. Samples of diets, ort,s and feces of forty Santa Ines lambs were subjected to both methods and analyzed for DM, MM, NDF, ADF, CP, and EE for future calculations for intake and digestibility. Most of the model's correlation coefficient was in the range of 0.66 to 0.81, being suitable for quantitative prediction. Highest values for CP content of 0.85 (diets) and 0.87 (orts) were observed. There were high correlations between the methods to predicting intake (average values of 0.93) and digestibility (average values of 0.93). Correlations between the variables obtained by the prediction of NIRS and the conventional method were adequate, showing that regardless of the method, the nutritional content of diets, orts and feces can be used to calculate the intake and digestibility of DM and nutrients of lambs' diets. The Near-IR spectroscopy method is recommended for accuracy, speed and low cost compared to conventional method.(AU)


Assuntos
Animais , Ingestão de Alimentos , Espectrofotometria Infravermelho , Análise Espectral/tendências , Ovinos/metabolismo
9.
J Sep Sci ; 40(1): 138-151, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27902885

RESUMO

The vacuum ultraviolet spectrophotometer was developed recently as an alternative to existing gas chromatography detectors. This detector measures the absorption of gas-phase chemical species in the range of 120-240 nm, where all chemical compounds present unique absorption spectra. Therefore, qualitative analysis can be performed and quantification follows standard Beer-Lambert law principles. Different fields of application, such as petrochemical, food, and environmental analysis have been explored. Commonly demonstrated is the capability for facile deconvolution of co-eluting analytes. The concept of additive absorption for co-eluting analytes has also been advanced for classification and speciation of complex mixtures using a data treatment procedure termed time interval deconvolution. Furthermore, pseudo-absolute quantitation can be performed for system diagnosis, as well as potentially calibrationless quantitation. In this manuscript an overview of these features, the vacuum ultraviolet spectrophotometer instrumentation, and performance capabilities are given. A discussion of the applications of the vacuum ultraviolet detector is provided by describing and discussing the papers published thus far since 2014.


Assuntos
Cromatografia Gasosa/tendências , Análise Espectral/tendências , Vácuo
10.
Top Magn Reson Imaging ; 25(5): 215-221, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27748706

RESUMO

With its exquisite anatomical resolution and wide-ranging functional imaging capabilities, magnetic resonance imaging (MRI) has found multiple applications in detection, staging, and monitoring treatment response in cancer. The metabolic information provided by magnetic resonance spectroscopy (MRS) is being actively investigated to complement MRI parameters, as well as existing biomarkers, in cancer detection and in monitoring response to treatment. Located at the interface of detection and therapy, theranostic imaging is a rapidly expanding new field that is showing significant promise for precision medicine of cancer. Innovations in the development of novel nanoparticles decorated with imaging reporters that can be used to deliver therapeutic cargo to specific cells and environments have provided new roles for MRI and MRS in theranostic imaging.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias/diagnóstico por imagem , Análise Espectral , Nanomedicina Teranóstica , Humanos , Imageamento por Ressonância Magnética/tendências , Análise Espectral/tendências , Nanomedicina Teranóstica/tendências
11.
Faraday Discuss ; 187: 603-7, 2016 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-27250100

RESUMO

The Faraday Discussion meeting "Advanced Vibrational Spectroscopy for Biomedical Applications" provided an excellent opportunity to share and discuss recent research and applications on a highly interdisciplinary level. Spectral pathology, single cell analysis, data handling, clinical spectroscopy, and the spectral analysis of biofluids were among the topics covered during the meeting. The focus on discussion rather than "merely" presentation was highly appreciated and fruitful discussions evolved around the interpretation of the amide-bands, optical resolution, the role of diffraction and data analysis procedure, to name a few. The meeting made clear that the spectroscopy of molecular vibrations in biomolecules has evolved from a purely academic research tool to a technology used in clinical practice in some cases. In this sense, biomedical vibrational spectroscopy has reached a pivotal point at which questions like diagnostic value, therapeutic consequence and financial viability are gaining more and more importance.


Assuntos
Medicina Clínica/métodos , Análise Espectral/tendências , Líquidos Corporais/química , Líquidos Corporais/diagnóstico por imagem , Medicina Clínica/tendências , Congressos como Assunto , Humanos , Análise de Célula Única , Análise Espectral/economia , Vibração
12.
J Sci Food Agric ; 95(8): 1571-6, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25205443

RESUMO

As the beer market is steadily expanding, it is important for the brewing industry to offer consumers a product with the best organoleptic characteristics, flavour being one of the key characteristics of beer. New trends in instrumental methods of beer flavour analysis are described. In addition to successfully applied methods in beer analysis such as chromatography, spectroscopy, nuclear magnetic resonance, mass spectrometry or electronic nose and tongue techniques, among others, sample extraction and preparation such as derivatization or microextraction methods are also reviewed.


Assuntos
Cerveja/análise , Técnicas de Química Analítica/tendências , Paladar , Técnicas Biossensoriais/tendências , Técnicas de Química Analítica/métodos , Cromatografia/tendências , Nariz Eletrônico , Humanos , Espectrometria de Massas/tendências , Microextração em Fase Sólida/tendências , Análise Espectral/tendências
13.
J Am Acad Dermatol ; 71(4): 611.e1-611.e10; quiz 621-2, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25219717

RESUMO

New evidence has accumulated over the past several years that supports improved melanoma outcomes associated with both clinician and patient screening. Population-based and workplace studies conducted in Australia and the Unites States, respectively, have shown decreases in the incidence of thick melanoma and overall melanoma mortality, and a year-long statewide screening program in Germany has shown a nearly 50% reduction in mortality 5 years after the screening ended. Current melanoma screening guidelines in the United States are inconsistent among various organizations, and therefore rates of both physician and patient skin examinations are low. As policymaking organizations update national screening recommendations in the United States, the latest research reviewed in part II of this continuing medical education article should be considered to establish the most effective recommendations. Patient and provider education will be necessary to ensure that appropriate patients receive recommended screening.


Assuntos
Detecção Precoce de Câncer/normas , Melanoma/diagnóstico , Melanoma/epidemiologia , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/epidemiologia , Adulto , Idoso , Biópsia por Agulha , Dermoscopia/normas , Dermoscopia/tendências , Detecção Precoce de Câncer/tendências , Educação Médica Continuada , Feminino , Previsões , Promoção da Saúde/organização & administração , Humanos , Masculino , Programas de Rastreamento/normas , Programas de Rastreamento/tendências , Microscopia Confocal/normas , Microscopia Confocal/tendências , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Guias de Prática Clínica como Assunto , Programa de SEER , Análise Espectral/normas , Análise Espectral/tendências , Estados Unidos/epidemiologia
14.
Proc Natl Acad Sci U S A ; 111(35): 12634-40, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25092345

RESUMO

The discovery and characterization of exoplanets have the potential to offer the world one of the most impactful findings ever in the history of astronomy--the identification of life beyond Earth. Life can be inferred by the presence of atmospheric biosignature gases--gases produced by life that can accumulate to detectable levels in an exoplanet atmosphere. Detection will be made by remote sensing by sophisticated space telescopes. The conviction that biosignature gases will actually be detected in the future is moderated by lessons learned from the dozens of exoplanet atmospheres studied in last decade, namely the difficulty in robustly identifying molecules, the possible interference of clouds, and the permanent limitations from a spectrum of spatially unresolved and globally mixed gases without direct surface observations. The vision for the path to assess the presence of life beyond Earth is being established.


Assuntos
Atmosfera/química , Meio Ambiente Extraterreno/química , Origem da Vida , Planetas , Análise Espectral/tendências , Evolução Planetária , Gases , Água
15.
Curr Pharm Des ; 20(3): 436-53, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23651397

RESUMO

A common feature of many new analytical techniques that allows fast and non-destructive analysis of poorly-water-soluble drug is that they generate a large amount of data with a multivariate character within a short time frame, which in turn highlights the need for advanced data analytical methods in extracting information from the complex data set. The current review critically examines how spectroscopy and imaging techniques can be utilized for fast and non-destructive characterization of solid state poorly water-soluble drug formulations. The first part of the present review describes the basics behind many of the currently used methods including Raman, near infrared (NIR), infrared (IR) spectroscopy and X-ray powder diffractometry in characterizing poorly water soluble drugs. Key emphasis was placed on a critical review of the currently used spectral preprocessing methods, and the influence of selected preprocessing on spectral data sets is exemplified. Further the existing uni- and multivariate spectral data analytical methods in analyzing complex spectral data sets are reviewed, covering estimation of spectral peak moments, peak modeling, variations of Principal Component Analysis (PCA), variations of Partial Least Squares (PLS) analysis and Multivariate Curve Resolution (MCR). The second part of the present review discusses hyperspectral imaging, UV imaging, optical microscopy imaging and process imaging methods suitable for characterization of poorly water-soluble solid state drug formulations. Image analytical techniques suitable for analyzing hyperspectral image data set are described. Further, the application of various image analytical techniques leading to the estimation of nucleation and crystal growth rates from polarized light microscopy is described.


Assuntos
Imagem Molecular/métodos , Preparações Farmacêuticas/química , Análise Espectral/métodos , Tecnologia Farmacêutica/métodos , Água , Análise dos Mínimos Quadrados , Modelos Químicos , Imagem Molecular/instrumentação , Imagem Molecular/tendências , Análise Multivariada , Preparações Farmacêuticas/análise , Análise de Componente Principal , Solubilidade , Análise Espectral/instrumentação , Análise Espectral/tendências , Tecnologia Farmacêutica/instrumentação , Tecnologia Farmacêutica/tendências , Água/química
16.
Diagn Pathol ; 7: 98, 2012 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-22889003

RESUMO

Epithelial cancers account for substantial mortality and are an important public health concern. With the need for earlier detection and treatment of these malignancies, the ability to accurately detect precancerous lesions has an increasingly important role in controlling cancer incidence and mortality. New optical technologies are capable of identifying early pathology in tissues or organs in which cancer is known to develop through stages of dysplasia, including the esophagus, colon, pancreas, liver, bladder, and cervix. These diagnostic imaging advances, together as a field known as optical endomicroscopy, are based on confocal microscopy, spectroscopy-based imaging, and optical coherence tomography (OCT), and function as "optical biopsies," enabling tissue pathology to be imaged in situ and in real time without the need to excise and process specimens as in conventional biopsy and histopathology. Optical biopsy techniques can acquire high-resolution, cross-sectional images of tissue structure on the micron scale through the use of endoscopes, catheters, laparoscopes, and needles. Since the inception of these technologies, dramatic technological advances in accuracy, speed, and functionality have been realized. The current paradigm of optical biopsy, or single-area, point-based images, is slowly shifting to more comprehensive microscopy of larger tracts of mucosa. With the development of Fourier-domain OCT, also known as optical frequency domain imaging or, more recently, volumetric laser endomicroscopy, comprehensive surveillance of the entire distal esophagus is now achievable at speeds that were not possible with conventional OCT technologies. Optical diagnostic technologies are emerging as clinically useful tools with the potential to set a new standard for real-time diagnosis. New imaging techniques enable visualization of high-resolution, cross-sectional images and offer the opportunity to guide biopsy, allowing maximal diagnostic yields and appropriate staging without the limitations and risks inherent with current random biopsy protocols. However, the ability of these techniques to achieve widespread adoption in clinical practice depends on future research designed to improve accuracy and allow real-time data transmission and storage, thereby linking pathology to the treating physician. These imaging advances are expected to eventually offer a see-and-treat paradigm, leading to improved patient care and potential cost reduction. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5372548637202968.


Assuntos
Neoplasias Epiteliais e Glandulares/patologia , Imagem Óptica/tendências , Lesões Pré-Cancerosas/patologia , Biópsia/tendências , Detecção Precoce de Câncer , Desenho de Equipamento , Humanos , Interpretação de Imagem Assistida por Computador , Microscopia Confocal/tendências , Neoplasias Epiteliais e Glandulares/terapia , Imagem Óptica/instrumentação , Imagem Óptica/métodos , Lesões Pré-Cancerosas/terapia , Valor Preditivo dos Testes , Prognóstico , Análise Espectral/tendências , Tomografia de Coerência Óptica/tendências
17.
Pediatrics ; 129(4): 689-94, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22430456

RESUMO

OBJECTIVE: Although transcutaneous bilirubinometers have existed for over 30 years, the clinical utility of the technique is limited to a screening method for hyperbilirubinemia, rather than a replacement for invasive blood sampling. In this study, we investigate the reason for this limited clinical value and address possibilities for improvement. METHODS: To obtain better insight into the physiology of bilirubin measurements, we evaluated a transcutaneous bilirubinometer that determines not only the cutaneous bilirubin concentration (TcB) but also the blood volume fraction (BVF) in the investigated skin volume. For 49 neonates (gestational age 30 ± 3.1 weeks, postnatal age 6 [4-10] days) at our NICU, we performed 124 TcB and 55 BVF measurements. RESULTS: The TcB correlated well with the total serum bilirubin concentration (TSB) (r = 0.88) with an uncertainty of 55 µmol/L. The BVF in the measured skin volume ranged between 0.1% and 0.75%. CONCLUSIONS: The performance of our bilirubinometer is comparable to existing transcutaneous devices. The limited clinical value of current bilirubinometers can be explained by the low BVF in the skin volume that is probed by these devices. Because the TcB depends for over 99% on the contribution of extravascular bilirubin, it is a physiologically different parameter from the TSB. Hence, the standard method of evaluation that compares the TcB to the TSB is insufficient to fully investigate the clinical value of transcutaneous bilirubinometers, ie, their predictive value for kernicterus. We suggest that the clinical value may be improved considerably by changing either the method of evaluation or the technological design of transcutaneous bilirubinometers.


Assuntos
Bilirrubina/sangue , Icterícia Neonatal/diagnóstico , Triagem Neonatal/métodos , Análise Espectral/métodos , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Icterícia Neonatal/sangue , Masculino , Valor Preditivo dos Testes , Curva ROC , Análise Espectral/tendências
18.
Biotech Histochem ; 87(4): 288-94, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22148999

RESUMO

Raphael Meldola (1849-1915), English industrial and academic chemist, spectroscopist, naturalist, educator and lobbyist for science, is today almost a forgotten scientist whose life is celebrated only with a medal awarded by the Royal Society of Chemistry that honors achievement by younger chemists. In the 1870-80s, however, he invented a number of important synthetic dyestuffs including the cotton dyes isamine blue and Meldola's blue, and also naphthol green B, all of which have had application in biology and medicine. I describe here the early emergence of the synthetic dye industry, the first science-based industry, Meldola's role in its development, and his own inventions. Meldola's wide ranging achievements in science led to appointments as president of important professional scientific and manufacturers' societies. He was a fervent disciple of natural selection, a correspondent of Charles Darwin, and a prominent 19(th)-century neo-Darwinian. In 1886, drawing on analogies with evolutionary theory, he warned the British that neglect of science, particularly chemistry, would lead to industrial decline and even extinction, though his message generally was ignored, at least until 1914.


Assuntos
Compostos Cromogênicos/química , Análise Espectral , História do Século XIX , História do Século XX , Análise Espectral/história , Análise Espectral/tendências
19.
Nat Rev Gastroenterol Hepatol ; 8(10): 547-53, 2011 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-21894196

RESUMO

Gastrointestinal endoscopy is undergoing major improvements, which are driven by new available technologies and substantial refinements of optical features. In this Review, we summarize available and evolving imaging technologies that could influence the clinical algorithm of endoscopic diagnosis. Detection, characterization and confirmation are essential steps required for proper endoscopic diagnosis. Optical and nonoptical methods can help to improve each step; these improvements are likely to increase the detection rate of neoplasias and reduce unnecessary endoscopic treatments. Furthermore, functional and molecular imaging are emerging as new diagnostic tools that could provide an opportunity for personalized medicine, in which endoscopy will define disease outcome or predict the response to targeted therapy.


Assuntos
Endoscopia Gastrointestinal/métodos , Endoscopia Gastrointestinal/tendências , Gastroenteropatias/diagnóstico , Diagnóstico por Imagem/instrumentação , Diagnóstico por Imagem/métodos , Diagnóstico por Imagem/tendências , Endoscopia Gastrointestinal/instrumentação , Humanos , Microscopia Confocal/instrumentação , Microscopia Confocal/métodos , Microscopia Confocal/tendências , Análise Espectral/instrumentação , Análise Espectral/métodos , Análise Espectral/tendências , Tomografia de Coerência Óptica/instrumentação , Tomografia de Coerência Óptica/métodos , Tomografia de Coerência Óptica/tendências
20.
Phys Chem Chem Phys ; 12(38): 12012-23, 2010 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-20714472

RESUMO

Inelastic electron tunneling excitation has been realized in the last decade as an effective way to probe reliably detailed atomic structures and control precisely behaviors of surface adsorbates at a single molecule level. A good understanding of rich and complex processes on the surface under inelastic electron excitations is of great importance, not only from a fundamental scientific point of view but also for potential practical applications. In this perspective paper, we give an overview of recent developments on excitations and characterizations of inelastic electron tunneling processes in surface adsorbates and molecular junctions. Special attention has been paid to the understanding of the randomness of the processes. A recently proposed general statistical model is introduced which has resolved a long-standing puzzle concerning the experimentally observed non-integer power law relationship between the rate of molecular conformation changes and the tunneling current. The success of the new model is highlighted by its applications for molecular switches.


Assuntos
Elétrons , Microscopia de Tunelamento/tendências , Microscopia de Tunelamento/métodos , Modelos Estatísticos , Análise Espectral/métodos , Análise Espectral/tendências
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