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1.
Nat Commun ; 9(1): 617, 2018 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-29434294

RESUMO

Exposure to ambient fine particulate matter (PM2.5) is a leading contributor to diseases in India. Previous studies analysing emission source attributions were restricted by coarse model resolution and limited PM2.5 observations. We use a regional model informed by new observations to make the first high-resolution study of the sector-specific disease burden from ambient PM2.5 exposure in India. Observed annual mean PM2.5 concentrations exceed 100 µg m-3 and are well simulated by the model. We calculate that the emissions from residential energy use dominate (52%) population-weighted annual mean PM2.5 concentrations, and are attributed to 511,000 (95UI: 340,000-697,000) premature mortalities annually. However, removing residential energy use emissions would avert only 256,000 (95UI: 162,000-340,000), due to the non-linear exposure-response relationship causing health effects to saturate at high PM2.5 concentrations. Consequently, large reductions in emissions will be required to reduce the health burden from ambient PM2.5 exposure in India.


Assuntos
Poluentes Atmosféricos/análise , Gasolina/efeitos adversos , Material Particulado/análise , Poluição do Ar/análise , Exposição Ambiental , Monitoramento Ambiental , Gasolina/análise , Habitação , Humanos , Índia
6.
Opt Lett ; 42(5): 963-966, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-28248342

RESUMO

Interactions between whispering gallery modes (WGMs) and small nanoparticles are commonly modeled by treating the particle as a point dipole scatterer. This approach is assumed to be accurate as long as the nanoparticle radius, a, is small compared to the WGM wavelength λ. In this Letter, however, we show that the large field gradients associated with the evanescent decay of a WGM causes the dipole theory to significantly underestimate the interaction strength and, hence, the induced WGM resonance shift, even for particles as small as a∼λ/10. To mitigate this issue, we employ a renormalized Born approximation to more accurately determine nanoparticle-induced resonance shifts and, hence, enable improved particle sizing. The domain of validity of this approximation is investigated, and supporting experimental results are presented.

7.
Front Neurol ; 7: 40, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27047446

RESUMO

Cervical mobilization and manipulation are frequently used to treat patients diagnosed with cervicogenic headache (CEH); however, there is conflicting evidence on the efficacy of these manual therapy techniques. The purpose of this review is to investigate the effects of cervical mobilization and manipulation on pain intensity and headache frequency, compared to traditional physical therapy interventions in patients diagnosed with CEH. A total of 66 relevant studies were originally identified through a review of the literature, and the 25 most suitable articles were fully evaluated via a careful review of the text. Ultimately, 10 studies met the inclusion criteria: (1) randomized controlled trial (RCT) or open RCT; the study contained at least two separate groups of subjects that were randomly assigned either to a cervical spine mobilization or manipulation or a group that served as a comparison; (2) subjects must have had a diagnosis of CEH; (3) the treatment group received either spinal mobilization or spinal manipulation, while the control group received another physical therapy intervention or placebo control; and (4) the study included headache pain and frequency as outcome measurements. Seven of the 10 studies had statistically significant findings that subjects who received mobilization or manipulation interventions experienced improved outcomes or reported fewer symptoms than control subjects. These results suggest that mobilization or manipulation of the cervical spine may be beneficial for individuals who suffer from CEH, although heterogeneity of the studies makes it difficult to generalize the findings.

8.
Nano Lett ; 13(7): 3347-51, 2013 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-23777440

RESUMO

Recently we reported the detection and sizing of the smallest RNA virus MS2 with a mass of 6 ag from the resonance frequency shift of a whispering gallery mode-nanoshell hybrid resonator (WGM-h) upon adsorption on the nanoshell and anticipated that single protein above 0.4 ag should be detectable but with considerably smaller signals. Here, we report the detection of single thyroid cancer marker (Thyroglobulin, Tg) and bovine serum albumin (BSA) proteins with masses of only 1 ag and 0.11 ag (66 kDa), respectively. However, the wavelength shifts are enhanced beyond those anticipated in our earlier work by 240% for Tg and 1500% for BSA. This surprising sensitivity is traced to a short-range reactive field near the surface of our Au nanoshell receptor due to intrinsic random bumps of protein size, leading to an unanticipated increase in sensitivity to single protein, which grows larger as the protein diminishes in size. As a consequence of the largest signal-to-noise ratio in our BSA experiments (S/N ≈ 13), we conservatively estimated a new protein limit of detection for our WGM-h of 5 kDa.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Microquímica/instrumentação , Análise Serial de Proteínas/instrumentação , Proteínas/análise , Proteínas/química , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Miniaturização , Coloração e Rotulagem , Integração de Sistemas
9.
Opt Express ; 20(24): 26147-59, 2012 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-23187470

RESUMO

We propose the attachment of a periodic array of gold nanoparticles (epitopes) to the equator of a Whispering Gallery Mode Biosensor for the purpose of plasmonically enhancing nanoparticle sensing in a self-referencing manner while increasing the capture rate of analyte to antibodies attached to these plasmonic epitopes. Our approach can be applied to a variety of whispering gallery mode resonators from silicon/silica rings and disks to capillaries. The interpretation of the signals is particularly simple since the optical phase difference between the epitopes is designed to be an integer multiple of ?, allowing the wavelength shift from each binding event to add independently.


Assuntos
Técnicas Biossensoriais/instrumentação , Epitopos , Nanopartículas , Dispositivos Ópticos , Refratometria/instrumentação , Termografia/instrumentação , Desenho de Equipamento , Ouro , Humanos , Reprodutibilidade dos Testes , Dióxido de Silício
10.
Langmuir ; 26(16): 13722-6, 2010 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-20695626

RESUMO

We report the first evidence for functionalization of Ga(2)O(3) nanowires (NWs), which have been incorporated as the active material in room temperature capacitance gas-sensing devices. An adsorbed layer of pyruvic acid (PA) was successfully formed on Ga(2)O(3) NWs by simple room temperature vapor transport, which was confirmed by Fourier transform infrared spectroscopy. The effect of the adsorbed PA on the surface properties was demonstrated by the change in the response of the NW gas-sensing devices. Results indicate that the adsorption of PA reduced the sensitivity of the Ga(2)O(3) NW device to common hydrocarbons such as nitromethane and acetone while improving the response to triethylamine by an order of magnitude. Taking into account the simplicity of this functionalization together with the ease of producing these capacitance-based gas-sensing devices, this approach represents a viable technique for sensor development.

11.
Proc Natl Acad Sci U S A ; 107(37): 16039-42, 2010 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-20798062

RESUMO

Optofluidic dye lasers hold great promise for adaptive photonic devices, compact and wavelength-tunable light sources, and micro total analysis systems. To date, however, nearly all those lasers are directly excited by tuning the pump laser into the gain medium absorption band. Here we demonstrate bioinspired optofluidic dye lasers excited by FRET, in which the donor-acceptor distance, ratio, and spatial configuration can be precisely controlled by DNA scaffolds. The characteristics of the FRET lasers such as spectrum, threshold, and energy conversion efficiency are reported. Through DNA scaffolds, nearly 100% energy transfer can be maintained regardless of the donor and acceptor concentration. As a result, efficient FRET lasing is achieved at an unusually low acceptor concentration of micromolar, over 1,000 times lower than that in conventional optofluidic dye lasers. The lasing threshold is on the order of µJ/mm(2). Various DNA scaffold FRET lasers are demonstrated to illustrate vast possibilities in optofluidic laser designs. Our work opens a door to many researches and applications such as intracavity bio/chemical sensing, biocontrolled photonic devices, and biophysics.


Assuntos
DNA/química , Transferência Ressonante de Energia de Fluorescência , Conformação de Ácido Nucleico
12.
Nat Methods ; 5(7): 591-6, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18587317

RESUMO

Optical label-free detectors, such as the venerable surface plasmon resonance (SPR) sensor, are generally favored for their ability to obtain quantitative data on intermolecular binding. However, before the recent introduction of resonant microcavities that use whispering gallery mode (WGM) recirculation, sensitivity to single binding events had not materialized. Here we describe the enhancement mechanisms responsible for the extreme sensitivity of the WGM biosensor, review its current implementations and applications, and discuss its future possibilities.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/estatística & dados numéricos , Técnicas Biossensoriais/tendências , Biotecnologia , Óptica e Fotônica/instrumentação , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície
13.
Conf Proc IEEE Eng Med Biol Soc ; 2008: 2177-80, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19163129

RESUMO

From a fundamental perspective, image reconstruction tasks in both ultrasound pulse echo and photoacoustic imaging are identical. We propose a C-scan imaging scheme that is applicable to both modalities where the image reconstruction is achieved through focusing action of an acoustic lens. The theory to characterize the imaging system is presented. Experimental methodology to determine the system point-spread-function is outlined and demonstrated with preliminary results.


Assuntos
Acústica/instrumentação , Processamento de Imagem Assistida por Computador/instrumentação , Lentes , Ultrassom , Algoritmos , Desenho de Equipamento , Interpretação de Imagem Assistida por Computador/instrumentação , Lasers , Modelos Teóricos
14.
Breast Cancer Res ; 9(6): R82, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18036263

RESUMO

INTRODUCTION: Many of the DNA sequence variants identified in the breast cancer susceptibility gene BRCA1 remain unclassified in terms of their potential pathogenicity. Both multifactorial likelihood analysis and functional approaches have been proposed as a means to elucidate likely clinical significance of such variants, but analysis of the comparative value of these methods for classifying all sequence variants has been limited. METHODS: We have compared the results from multifactorial likelihood analysis with those from several functional analyses for the four BRCA1 sequence variants A1708E, G1738R, R1699Q, and A1708V. RESULTS: Our results show that multifactorial likelihood analysis, which incorporates sequence conservation, co-inheritance, segregation, and tumour immunohistochemical analysis, may improve classification of variants. For A1708E, previously shown to be functionally compromised, analysis of oestrogen receptor, cytokeratin 5/6, and cytokeratin 14 tumour expression data significantly strengthened the prediction of pathogenicity, giving a posterior probability of pathogenicity of 99%. For G1738R, shown to be functionally defective in this study, immunohistochemistry analysis confirmed previous findings of inconsistent 'BRCA1-like' phenotypes for the two tumours studied, and the posterior probability for this variant was 96%. The posterior probabilities of R1699Q and A1708V were 54% and 69%, respectively, only moderately suggestive of increased risk. Interestingly, results from functional analyses suggest that both of these variants have only partial functional activity. R1699Q was defective in foci formation in response to DNA damage and displayed intermediate transcriptional transactivation activity but showed no evidence for centrosome amplification. In contrast, A1708V displayed an intermediate transcriptional transactivation activity and a normal foci formation response in response to DNA damage but induced centrosome amplification. CONCLUSION: These data highlight the need for a range of functional studies to be performed in order to identify variants with partially compromised function. The results also raise the possibility that A1708V and R1699Q may be associated with a low or moderate risk of cancer. While data pooling strategies may provide more information for multifactorial analysis to improve the interpretation of the clinical significance of these variants, it is likely that the development of current multifactorial likelihood approaches and the consideration of alternative statistical approaches will be needed to determine whether these individually rare variants do confer a low or moderate risk of breast cancer.


Assuntos
Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Neoplasias da Mama/genética , Genes BRCA1 , Mutação de Sentido Incorreto , Alanina , Arginina , Neoplasias da Mama/patologia , Centrossomo , DNA Complementar , Análise Fatorial , Feminino , Predisposição Genética para Doença , Ácido Glutâmico , Glutamina , Glicina , Humanos , Imuno-Histoquímica , Queratinas/análise , Técnicas de Amplificação de Ácido Nucleico , Plasmídeos , Polimorfismo de Nucleotídeo Único , Valor Preditivo dos Testes , Receptores Estrogênicos/análise , Medição de Risco , Fatores de Risco , Análise de Sequência de DNA , Valina
15.
Opt Lett ; 32(9): 1147-9, 2007 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-17410264

RESUMO

Whispering gallery modes in a microsphere coated with three layers of high, low, and high refractive indices (RIs) are considered. Coastal modes and inland modes, centered on the outer and inner high-RI layers, exist as different radial modes. At right values of RI and thickness of the three layers, an inland mode and a coastal mode couple to produce a radial distribution of the photonic field that resembles bonding and antibonding orbitals. The coupling occurs across a layer of the middle low-RI layer, much thicker than the wavelength of light. The coupling is analyzed in a quantum-mechanical analog of a one-dimensional particle in a double-well potential.

16.
Biophys J ; 92(12): 4466-72, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17400701

RESUMO

The state of adsorbed protein molecules can be examined by comparing the shifts in a narrow line resonance wavelength of transverse electric (TE) and transverse magnetic (TM) whispering gallery modes (WGM) when the molecules adsorb onto a transparent microsphere that houses WGM. In adsorption of bovine serum albumin (BSA) onto an aminopropyl-modified silica microsphere, the TM/TE shift ratio indicated highly anisotropic polarizability of BSA in the direction normal to the surface, most likely ascribed to anchoring the heart-shaped protein molecule by one of its tips. The polarization-dependent resonance shift was confirmed when the surrounding refractive index was uniformly changed by adding salt, which would simulate adsorption of large objects.


Assuntos
Materiais Revestidos Biocompatíveis/química , Teste de Materiais/métodos , Soroalbumina Bovina/química , Soroalbumina Bovina/ultraestrutura , Dióxido de Silício/química , Adsorção , Campos Eletromagnéticos , Magnetismo , Microesferas , Ligação Proteica , Conformação Proteica , Propriedades de Superfície
17.
Opt Express ; 15(25): 17410-23, 2007 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-19551035

RESUMO

Theory is developed for frequency shift and linewidth-broadening induced by rodlike bacteria bound to micro-optical resonators. Optical shift of whispering gallery modes (WGMs) is modeled by introducing a form factor that accounts for random horizontal orientation of cylindrical bacteria bound by their high refractive index cell walls. Linewidth-broadening is estimated from scattering losses. Analytic results are confirmed by measurement using E.Coli as model system (~10(2) bacteria/mm(2) sensitivity), establishing the WGM biosensor as sensitive technique for detection and analysis of micro-organisms.

18.
J Environ Health ; 68(3): 10-7, 32, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16312251

RESUMO

New Mexico, one of four states on the U.S./Mexico border, is faced with a pressing concern--lack of water. Since the region is either arid or semiarid, it is chronically short of continually available surface-water resources. Groundwater resources are used beyond their capacity to be recharged, and most surface-water resources are used to the maximum. The quality of groundwater varies widely. As a result of nonpoint- and point-source contamination, as well as natural occurrence, water in some areas is too salty or has high levels of natural uranium, fluoride, or arsenic. To date, the New Mexico Environment Department (NMED) has recognized 1,400 cases of groundwater contamination, and 1,907 water supply wells have been affected (NMED, 2001a). Of approximate 4,000 miles of coninously flowing rivers and streams in New Mexico, 92 perent are affected by nonpoint sources of pollution (NMED, 2001b). Numerous critical water issues exist along the New Mexico/Mexico border as a result of the impending critical issue of water availability, usage, and quality, as well as the fast-growing population. Related public health problems along the New Mexico/Mexico border are indicative of the need for a holistic, concrete, and sustainable solution to meet water demands in New Mexico. In order to accomplish the goals an objectives of Border XXI, Healthy People 2010, and Heathy Border 2010, a comprehensive statewide water management plan is needed. Solutions to the water demands of the region will be addressed in a subsequent manuscript.


Assuntos
Abastecimento de Água , Planejamento em Saúde , Prioridades em Saúde , New Mexico , Estados Unidos , United States Environmental Protection Agency
19.
Phys Rev Lett ; 94(14): 145503, 2005 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15904074

RESUMO

Applying a strong static electric field to supersaturated aqueous glycine solutions resulted in the nucleation of the gamma polymorph. This is the first report of a strong dc field inducing the nucleation of a neutral solute in a supersaturated solution. We attribute this effect to the electric-field-induced orientation of the highly polar glycine molecules in large preexisting solute clusters, helping them organize into a crystalline structure. This result also lends further support to our proposed optical-Kerr mechanism for nonphotochemical laser-induced nucleation.


Assuntos
Glicina/química , Cristalização , Campos Eletromagnéticos , Excipientes Farmacêuticos/química , Soluções , Água/química
20.
Opt Lett ; 30(5): 510-2, 2005 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15789719

RESUMO

We optically characterize nanolayer (<150 nm) formation in situ on a silica microsphere in an aqueous environment by simultaneously following the shifts of whispering-gallery modes at two wavelengths. This approach was inspired by layer perturbation theory, which indicates that these two measurements can be used to determine independently both the thickness and the optical dielectric constant. The theory is verified for extreme cases and used to characterize a biophysically relevant hydrogel nanolayer with an extremely small excess refractive index of 0.0012.


Assuntos
Materiais Revestidos Biocompatíveis/química , Teste de Materiais/métodos , Nanoestruturas/química , Polilisina/química , Análise Espectral/métodos , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Materiais Revestidos Biocompatíveis/análise , Hidrogéis/análise , Hidrogéis/química , Teste de Materiais/instrumentação , Microesferas , Nanoestruturas/análise , Polilisina/análise , Refratometria/métodos
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