Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
EMBO Rep ; 25(2): 524-543, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38253688

RESUMO

Metabolites derived from the intestinal microbiota play an important role in maintaining skeletal muscle growth, function, and metabolism. Here, we found that D-malate (DMA) is produced by mouse intestinal microorganisms and its levels increase during aging. Moreover, we observed that dietary supplementation of 2% DMA inhibits metabolism in mice, resulting in reduced muscle mass, strength, and the number of blood vessels, as well as the skeletal muscle fiber type I/IIb ratio. In vitro assays demonstrate that DMA decreases the proliferation of vascular endothelial cells and suppresses the formation of blood vessels. In vivo, we further demonstrated that boosting angiogenesis by muscular VEGFB injection rescues the inhibitory effects of D-malate on muscle mass and fiber area. By transcriptomics analysis, we identified that the mechanism underlying the effects of DMA depends on the elevated intracellular acetyl-CoA content and increased Cyclin A acetylation rather than redox balance. This study reveals a novel mechanism by which gut microbes impair muscle angiogenesis and may provide a therapeutic target for skeletal muscle dysfunction in cancer or aging.


Assuntos
Células Endoteliais , Microbiota , Camundongos , Animais , Células Endoteliais/metabolismo , Acetilação , Ciclina A/metabolismo , Angiogênese , Malatos/metabolismo , Músculo Esquelético/metabolismo , Envelhecimento
2.
Circ J ; 88(3): 417-424, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38267051

RESUMO

BACKGROUND: This study aimed to investigate the association between estimated pulse wave velocity (ePWV) and mortality outcomes among individuals with hypertension.Methods and Results: Based on the National Health and Nutrition Examination Survey (NHANES) 1999-2018, a total of 14,396 eligible participants with hypertension were enrolled. The ePWV was calculated using the equation based on blood pressure and age. The mortality outcomes of included participants were directly acquired from the National Death Index database. The multivariable Cox regression analysis was used to examine the relationship between ePWV and mortality outcomes. Moreover, the restricted cubic spline (RCS) was also used to explore this relationship. Receiver operating characteristics curves (ROC) were adopted to evaluate the prognostic ability of ePWV for predicting mortality outcomes of patients with hypertension. The median follow-up duration was 10.8 years; individuals with higher an ePWV had higher risks of mortality from both all causes (HR: 2.79, 95% CI: 2.43-3.20) and cardiovascular diseases (HR: 3.41, 95% CI: 2.50-4.64). After adjusting for confounding factors, each 1 m/s increase in ePWV was associated with a 43% increase in all-cause mortality risk (HR: 1.43, 95% CI: 1.37-1.48) and a 54% increase in cardiovascular mortality risk (HR: 1.54, 95% CI: 1.43-1.66). CONCLUSIONS: This study indicates that ePWV is a novel prognostic indicator for predicting the risks of mortality among patients with hypertension.


Assuntos
Doenças Cardiovasculares , Sistema Cardiovascular , Hipertensão , Humanos , Inquéritos Nutricionais , Análise de Onda de Pulso
3.
Opt Express ; 31(9): 13943-13958, 2023 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-37157269

RESUMO

Imaging into thick scattering medium is a long-standing challenge. Beyond the quasi-ballistic regime, multiple scattering scrambles the spatiotemporal information of incident/emitted light, making canonical imaging based on light focusing nearly impossible. Diffusion optical tomography (DOT) is one of the most popular approach to look inside scattering medium, but quantitatively inverting the diffusion equation is ill-posed, and prior information of the medium is typically necessary, which is nontrivial to obtain. Here, we show theoretically and experimentally that, by synergizing the one-way light scattering characteristic of single pixel imaging with ultrasensitive single photon detection and a metric-guided image reconstruction, single photon single pixel imaging can serve as a simple and powerful alternative to DOT for imaging into thick scattering medium without prior knowledge or inverting the diffusion equation. We demonstrated an image resolution of 12 mm inside a 60 mm thick (∼ 78 mean free paths) scattering medium.

4.
Appl Opt ; 62(4): 1109-1114, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36821171

RESUMO

Large-scale laser gyroscopes with sufficiently high sensitivity for measurement of the rotation rate of the Earth Ω E are inertial sensors with the capability to provide Earth orientation parameters, i.e., rotation rate and polar motion in near real time. Larger-scale passive resonant gyroscopes (PRGs) theoretically have a lower shot-noise limit. However, the cavity perimeter fluctuations and laser frequency noise become challenges in a passive gyro. In this paper, we introduce a three-wave differential locking scheme for large-scale PRGs, resulting in an in situ measurement of the cavity perimeter with nanometer resolution. Furthermore, the laser frequency noise is effectively suppressed with an additional gain of 30 dB by a double-stage locking system, based on the three-wave differential locking scheme. Finally, the rotation rate resolution of our 3m×3m gyroscope improves to 1.1×10-9 r a d/s over 200 s. The simplicity, robustness, and effectiveness of the locking scheme are important to the long-term operation of large-scale PRGs aiming for applications in the geosciences.

5.
Sensors (Basel) ; 23(8)2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37112462

RESUMO

This paper proposes a new optimized parameter model that enhances the pointing accuracy of moving-platform electro-optical telescopes (MPEOTs). The study begins by comprehensively analyzing the error sources, including the telescope and the platform navigation system. Next, a linear pointing correction model is established based on the target positioning process. To eliminate multicollinearity, stepwise regression is applied to obtain the optimized parameter model. The experimental results show that the MPEOT corrected by this model outperforms the mount model, with pointing errors of less than 50 arcsec for approximately 23 h. In the three tests conducted, the modified azimuth error(s) (RMS) were 14.07″, 12.71″, and 28.93″, and the elevation error(s) (RMS) were 12.94″, 12.73″, and 28.30″, respectively.

6.
Mol Pharm ; 19(7): 2217-2230, 2022 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-35575590

RESUMO

Overexpression of apoptotic factors in the inner ear is generally proven to induce ototoxicity. This has aroused research interest in various antiapoptotic drugs, the most representative of which is curcumin (CUR). In this study, two nanoformulations of CUR were developed with sustained-release behavior to improve their protective effects against ototoxic hearing loss (HL), which were the nanoparticles of CUR-loaded poly(lactic acid-glycolic acid) (CUR-PLGA NPs) and CUR-loaded chitosan-coated PLGA NPs (CUR-CS/PLGA NPs). The obtained results revealed that both CUR-NPs provided otoprotection in vitro and in vivo, and their effective doses in guinea pigs were much less than that of dexamethasone, which was clinically used to treat HL. Moreover, relative to CUR and CUR-PLGA NPs, CUR-CS/PLGA NPs exhibited the highest accumulation in HEI-OC1 cells and guinea pigs' cochlea. In pharmacodynamic experiments, the optimal administration timing was investigated, and CUR-CS/PLGA NPs showed sustained efficacy and the best hearing improvement at all tested sound frequencies. Lastly, the protective effect of CUR nanoformulations was further validated via inhibition of Caspase-3 and Bax activation, thereby reducing the concentration of reactive oxygen species and protecting mitochondrial integrity in hair cells. Collectively, CUR-CS/PLGA NPs demonstrated potent and lasting effects against ototoxic HL, making our novel formulation a promising candidate for the alleviation of sensorineural HL.


Assuntos
Quitosana , Curcumina , Perda Auditiva , Nanopartículas , Animais , Curcumina/farmacologia , Cobaias , Perda Auditiva/induzido quimicamente , Perda Auditiva/tratamento farmacológico , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
7.
Am J Otolaryngol ; 42(2): 102891, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33422947

RESUMO

OBJECTIVES: Cochlear microcirculation disturbance caused by vasculopathy is a common cause of sudden deafness (SD). Reactive oxygen species (ROS) plays an important role in cochlear injury during ischemia-reperfusion. Butylphthalide can improve microcirculation, reduce ROS formation and inhibit apoptosis. The aim of this study was to investigate the therapeutic effect of butylphthalide on patients with SD. PATIENTS AND METHODS: The hearing gains from 32 ears treated with butylphthalide were compared with that of 32 ears treated with non-butylphthalide. Butylphthalide capsules was administrated orally on an empty stomach for 10 continuous days. There were no significant differences in audiological and clinical data between butylphthalide and non-butylphthalide groups. RESULTS: The hearing gain of butylphthalide group at 500, 1000, 2000, and 4000 Hz was significantly higher than that of non-butylphthalide group correspondingly (P<0.01). And, the hearing gain at PTA (pure-tone average of 500, 1000, 2000, and 4000 Hz) in butylphthalide group was significantly higher than that of non-butylphthalide group (P<0.01). CONCLUSION: The recovery of hearing in butylphthalide group was significantly better than that of non-butylphthalide group. It is confirmed that butylphthalide has a definite therapeutic effect on SD.


Assuntos
Benzofuranos/uso terapêutico , Perda Auditiva Súbita/tratamento farmacológico , Perda Auditiva Súbita/etiologia , Adulto , Audiometria de Tons Puros , Cóclea/irrigação sanguínea , Feminino , Audição , Perda Auditiva Súbita/fisiopatologia , Humanos , Masculino , Microcirculação , Pessoa de Meia-Idade , Espécies Reativas de Oxigênio/efeitos adversos , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/complicações , Traumatismo por Reperfusão/metabolismo , Resultado do Tratamento
8.
J Therm Spray Technol ; 30(1-2): 1-24, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-38624582

RESUMO

There have been ever-growing demands for disinfection of water and air in recent years. Efficient, eco-friendly, and cost-effective methods of disinfection for pathogens are vital to the health of human beings. The photocatalysis route has attracted worldwide attention due to its highly efficient oxidative capabilities and sustainable recycling, which can be used to realize the disinfection purposes without secondary pollution. Though many studies have comprehensively reviewed the work about photocatalytic disinfection, including design and fabrication of photocatalytic coatings, inactivation mechanisms, or practical applications, systematic reviews about the disinfection photocatalysis coatings from fabrication to effort for practical use are still rare. Among different ways of fabricating photocatalytic materials, thermal spray is a versatile surface coating technique and competitive in constructing large-scale functional coatings, which is a most promising way for the future environmental purification, biomedical and life health applications. In this review, we briefly introduced various photocatalytic materials and corresponding inactivation mechanisms for virus, bacteria and fungus. We summarized the thermal-sprayed photocatalysts and their antimicrobial performances. Finally, we discussed the future perspectives of the photocatalytic disinfection coatings for potential applications. This review would shed light on the development and implementation of sustainable disinfection strategies that is applicable for extensive use for controlling pathogens in the near future.

9.
Opt Lett ; 45(14): 3921-3924, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32667319

RESUMO

Non-line-of-sight (NLOS) imaging is a light-starving application that suffers from highly noisy measurement data. In order to recover the hidden scene with good contrast, it is crucial for the reconstruction algorithm to be robust against noises and artifacts. We propose here two weighting factors for the filtered backprojection (FBP) reconstruction algorithm in NLOS imaging. The apodization factor modifies the aperture (wall) function to reduce streaking artifacts, and the coherence factor evaluates the spatial coherence of measured signals for noise suppression. Both factors are simple to evaluate, and their synergistic effects lead to state-of-the-art reconstruction quality for FBP with noisy data. We demonstrate the effectiveness of the proposed weighting factors on publicly accessible experimental datasets.

10.
Opt Lett ; 45(16): 4400-4403, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32796968

RESUMO

Compressed ultrafast photography (CUP) is a computational optical imaging technique that can capture transient dynamics at an unprecedented speed. Currently, the image reconstruction of CUP relies on iterative algorithms, which are time-consuming and often yield nonoptimal image quality. To solve this problem, we develop a deep-learning-based method for CUP reconstruction that substantially improves the image quality and reconstruction speed. A key innovation toward efficient deep learning reconstruction of a large three-dimensional (3D) event datacube (x,y,t) (x,y, spatial coordinate; t, time) is that we decompose the original datacube into massively parallel two-dimensional (2D) imaging subproblems, which are much simpler to solve by a deep neural network. We validated our approach on simulated and experimental data.

11.
Nanotechnology ; 31(18): 185301, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31945757

RESUMO

It is known that ZnO is an n-type semiconductor with photocatalytic performances under ultraviolet light irradiation. Constructing a superior structure for a modified electron band has been one of the major research goals for photocatalytic ZnO. Here we report a new technical route for making nano-ZnO coatings with a porous topographic morphology. The coatings were fabricated by plasma spraying the mixture of suspension and solution liquid precursors. Pre-loading of ZnO and Zn powders in the precursor was carried out for the purpose of tailoring the structure of the coatings. The coatings in micron thicknesses showed a porous skeleton and a fluffy top layer consisting of ultrafine ZnO grains. Photocatalytic testing by measuring the degradation of methylene blue revealed significantly enhanced activities of the coatings deposited using the ZnO/Zn loaded precursor. The hybrid-structured ZnO coatings exhibited a narrowed band gap and modified oxygen defects as compared to those deposited from the single liquid feedstock. The results shed light on a one-step easy thermal spray fabrication of polytropic nanostructured functional coatings by employing solid powder-loaded liquid as the starting feedstock.

12.
Sensors (Basel) ; 20(18)2020 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-32961725

RESUMO

Large-scale laser gyroscopes have found important applications in Earth sciences due to their self-sufficient property of measurement of the Earth's rotation without any external references. In order to extend the relative rotation measurement accuracy to a better level so that it can be used for the determination of the Earth orientation parameters (EOP), we investigate the limitations in a passive resonant laser gyroscope (PRG) developed at Huazhong University of Science and Technology (HUST) to pave the way for future development. We identify the noise sources from the derived noise transfer function of the PRG. In the frequency range below 10-2Hz, the contribution of free-spectral-range (FSR) variation is the dominant limitation, which comes from the drift of the ring cavity length. In the 10-2 to 103Hz frequency range, the limitation is due to the noises of the frequency discrimination system, which mainly comes from the residual amplitude modulation (RAM) in the frequency range below 2 Hz. In addition, the noise contributed by the Mach-Zehnder-type beam combiner is also noticeable in the 0.01 to 2 Hz frequency range. Finally, possible schemes for future improvement are also discussed.

13.
Opt Lett ; 44(15): 3897-3900, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31368996

RESUMO

We present photoacoustic shadow-casting microscopy (PASM), a technique that allows high-resolution imaging of weakly absorbing biological samples with unprecedented sensitivity. In PASM, a uniform optical absorbing layer is placed in contact with the samples and is excited by the light transmitted through the sample, producing photoacoustic (PA) waves with an increased signal-to-noise ratio compared with that generated by the sample itself. Therefore, given a desired image quality, the required excitation fluence is much reduced, alleviating the photothermal damage to the specimen. The system provides a lateral resolution of 5 µm when using a 0.30 NA microscope objective lens. To demonstrate PASM, we present images of bovine red blood cells and microbeads.


Assuntos
Microscopia/métodos , Técnicas Fotoacústicas/métodos , Animais , Bovinos , Eritrócitos/citologia , Razão Sinal-Ruído
14.
Opt Eng ; 58(6)2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31244495

RESUMO

Structured-light depth cameras rely on projecting and resolving coded patterns on a three-dimensional scene with high contrast. The front-end optics of such depth cameras impose a fundamental restriction on the depth-sensing range and accuracy: the patterns only remain sharp within the depth of field jointly determined by the camera and projector. We present here a robust method to improve the depth-sensing range and accuracy for a structured-light depth camera without changing the underlying optical design. Moreover, it shows the unique advantage in macrophotography of highly light-scattering objects. We analyze the proposed method theoretically and validate it in experiments.

15.
Analyst ; 142(16): 2892-2896, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28726878

RESUMO

We proposed a novel noninvasive method for glucose detection using a photoacoustic (PA) technique utilizing both the peak-to-peak value and peak arrival time delay information. Without increasing apparatus and system complexity, we demonstrated the accuracy enhancement of 29.5% and 33.63% for high (0-7 g dL-1) and low (0-350 mg dL-1) concentration of glucose solution, compared to conventional amplitude-based prediction.


Assuntos
Glucose/análise , Técnicas Fotoacústicas , Análise Espectral
16.
Small ; 12(38): 5239-5244, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27490362

RESUMO

Two near-infrared dyes featuring good dispersion and light-harvesting property present a remarkable nonlinear photoacoustic response in vitro and in vivo comparing with conventional gold nanorods. This study benefits the fabrication of drug delivery platforms with accurate targeting and control effect under photoacoustic image guidance.


Assuntos
Corantes Fluorescentes/química , Imageamento Tridimensional , Raios Infravermelhos , Dinâmica não Linear , Compostos Orgânicos/química , Técnicas Fotoacústicas/métodos , Animais , Benzoatos/química , Verde de Indocianina/análogos & derivados , Verde de Indocianina/química , Indóis/química , Nanotubos/química , Nanotubos/ultraestrutura , Ratos
17.
Opt Express ; 23(16): 20617-28, 2015 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-26367914

RESUMO

Photoacoustic imaging and sensing have been studied extensively to probe the optical absorption of biological tissue in multiple scales ranging from large organs to small molecules. However, its elastic oscillation characterization is rarely studied and has been an untapped area to be explored. In literature, photoacoustic signal induced by pulsed laser is commonly modelled as a bipolar "N-shape" pulse from an optical absorber. In this paper, the photoacoustic damped oscillation is predicted and modelled by an equivalent mass-spring system by treating the optical absorber as an elastic oscillator. The photoacoustic simulation incorporating the proposed oscillation model shows better agreement with the measured signal from an elastic phantom, than conventional photoacoustic simulation model. More interestingly, the photoacoustic damping oscillation effect could potentially be a useful characterization approach to evaluate biological tissue's mechanical properties in terms of relaxation time, peak number and ratio beyond optical absorption only, which is experimentally demonstrated in this paper.

18.
Opt Lett ; 40(19): 4492-5, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26421564

RESUMO

This article describes a laser-shared photothermal system that achieves tight temperature regulation by frequency-domain photoacoustic (FD-PA) feedback. To this end, a continuous-wave laser system was designed with arbitrarily modulatable laser intensity. And, by fast alternating in the time domain between a constant laser intensity for photothermal heating and a modulated laser intensity for FD-PA temperature measurement, photothermal temperature variations are captured by FD-PA in real time. A proportional-integral-derivative (PID) controller monitors the feedback from FD-PA measurements and controls photothermal heating dose accordingly, thus stabilizing the temperature at preset values. The proposed system is demonstrated to achieve ultrafast temperature measurement at a 4 kHz rate, and with proper averaging, the measurement and regulation accuracy are 0.75 deg and 0.9 deg respectively.


Assuntos
Retroalimentação , Lasers , Técnicas Fotoacústicas , Fototerapia/métodos , Temperatura
19.
Opt Lett ; 40(15): 3568-71, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26258359

RESUMO

In this Letter, photoacoustic-guided Raman spectroscopy (PARS) is proposed for a fast depth-resolved Raman measurement with accurate depth localization. The approach was experimentally demonstrated to receive both photoacoustic and Raman signals from a three-layer agar phantom based on a developed synergic photoacoustic-Raman probe, showing strong depth correlation and achieving magnitude of faster operation speed due to photoacoustic time-of-flight measurement and guidance, compared with the conventional depth-resolved Raman spectroscopy method. In addition, further combination with advanced optical-focusing techniques in biological-scattering medium could potentially enable the proposed approach for cancer diagnostics with both tight and fast optical focusing at the desired depth of tumor.

20.
Opt Lett ; 39(12): 3414-7, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24978499

RESUMO

Thermally modulated photoacoustic imaging (TMPI) is reported here for contrast enhancement when using nanoparticles as contrast agents. Exploiting the excellent sensitivity of the photoacoustic (PA) process on temperature and the highly selective heating capability of nanoparticles under electromagnetic field, the PA signals stemming from the nanoparticles labeled region can be efficiently modulated whereas those from highly light absorptive backgrounds are minimally affected. A coherent difference imaging procedure reduces the background signal and thus improves the imaging contrast. Phantom experiments with super-paramagnetic iron oxide nanoparticles (SPIONs) as contrast agents and alternating magnetic fields for heating are demonstrated. Further improvements toward clinical applications are also discussed.


Assuntos
Nanopartículas de Magnetita , Técnicas Fotoacústicas/métodos , Meios de Contraste , Diagnóstico por Imagem/métodos , Diagnóstico por Imagem/estatística & dados numéricos , Temperatura Alta , Dinâmica não Linear , Fenômenos Ópticos , Imagens de Fantasmas , Técnicas Fotoacústicas/estatística & dados numéricos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA