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1.
Pestic Biochem Physiol ; 200: 105812, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38582584

RESUMO

Indoxacarb has been widely utilized in agricultural pest management, posing a significant ecological threat to Bombyx mori, a non-target economic insect. In the present study, short-term exposure to low concentration of indoxacarb significantly suppressed the oxidative phosphorylation pathway, and resulted in an accumulation of reactive oxygen species (ROS) in the midgut of B. mori. While, the ATP content exhibited a declining trend but there was no significant change. Moreover, indoxacarb also significantly altered the transcription levels of six autophagy-related genes, and the transcription levels of ATG2, ATG8 and ATG9 were significantly up-regulated by 2.56-, 1.90-, and 3.36-fold, respectively. The protein levels of ATG8-I and ATG8-II and MDC-stained frozen sections further suggested an increase in autophagy. Furthermore, the protein level and enzyme activity of CASP4 showed a significant increase in accordance with the transcription levels of apoptosis-related genes, indicating the activation of the apoptotic signaling pathway. Meanwhile, the induction of apoptosis signals in the midgut cells triggered by indoxacarb was confirmed through TUNEL staining. These findings suggest that indoxacarb can promote the accumulation of ROS by inhibiting the oxidative phosphorylation pathway, thereby inducing autophagy and apoptosis in the midgut cells of B. mori.


Assuntos
Bombyx , Oxazinas , Animais , Espécies Reativas de Oxigênio/metabolismo , Bombyx/fisiologia , Fosforilação Oxidativa , Apoptose , Autofagia , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
2.
IEEE Sens J ; 24(5): 6888-6897, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38476583

RESUMO

We developed an ankle-worn gait monitoring system for tracking gait parameters, including length, width, and height. The system utilizes ankle bracelets equipped with wide-angle infrared (IR) stereo cameras tasked with monitoring a marker on the opposing ankle. A computer vision algorithm we have also developed processes the imaged marker positions to estimate the length, width, and height of the person's gait. Through testing on multiple participants, the prototype of the proposed gait monitoring system exhibited notable performance, achieving an average accuracy of 96.52%, 94.46%, and 95.29% for gait length, width, and height measurements, respectively, despite distorted wide-angle images. The OptiGait system offers a cost-effective and user-friendly alternative compared to existing gait parameter sensing systems, delivering comparable accuracy in measuring gait length and width. Notably, the system demonstrates a novel capability in measuring gait height, a feature not previously reported in the literature.

3.
J Microencapsul ; 41(5): 360-374, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38804967

RESUMO

Aim: To prepare sweet tea extract microcapsules (STEMs) via a spray-drying by applying different wall material formulations with maltodextrin (MD), inulin (IN), and gum arabic (GA). Methods: The microcapsules were characterised by yield, encapsulation efficiency (EE), particle size, sensory evaluation, morphology, attenuated total reflectance-Fourier transform infra-red spectroscopy and in vitro digestion studies. Results: The encapsulation improved the physicochemical properties and bioactivity stability of sweet tea extract (STE). MD5IN5 had the highest yield (56.33 ± 0.06% w/w) and the best EE (e.g. 88.84 ± 0.36% w/w of total flavonoids). MD9GA1 obtained the smallest particle size (642.13 ± 4.12 nm). MD9GA1 exhibited the highest retention of bioactive components, inhibition of α-glucosidase (96.85 ± 0.55%), α-amylase (57.58 ± 0.99%), angiotensin-converting enzyme (56.88 ± 2.20%), and the best antioxidant activity during in vitro gastrointestinal digestion. Conclusion: The encapsulation of STE can be an appropriate way for the valorisation of STE with improved properties.


Assuntos
Antioxidantes , Cápsulas , Goma Arábica , Inulina , Extratos Vegetais , Polissacarídeos , Chá , Polissacarídeos/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Inulina/química , Chá/química , Goma Arábica/química , Antioxidantes/química , Antioxidantes/farmacologia , Inibidores de Glicosídeo Hidrolases/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/administração & dosagem , alfa-Amilases/química , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Tamanho da Partícula , Humanos , alfa-Glucosidases/química
4.
J Sci Food Agric ; 104(9): 5407-5418, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38345737

RESUMO

BACKGROUND: Silkworm (Bombyx moil L.) Pupa protein (SPP) is a high-quality insect protein and is considered a sustainable alternative source for traditional animal food protein. However, the utilization of SPP is limited because of its low solubility and emulsifying ability. In the present study, the synergistic effect of hydration and pulsed ultrasound on the physicochemical properties of SPP and SPP-stabilized Pickering emulsions was evaluated. RESULTS: Pulsed ultrasound changed the particle size of SPP and its conformation. As the pulsed ultrasound increased from 0 s to 5 s, the α-helix and SS contents of SPP decreased, whereas the ß-sheet and SH contents increased, which in turn improved its solubility and amphiphilicity. As a result, the SPP treated by a combination of 12 h of hydration and 3 s of ultrasound exhibited a contact angle of 74.95°, hydrophobicity of 904.83, EAI of 6.66 m2 g-1 and ESI of 190.69 min. Compared with the combination of 1 h of hydration and 5 s of ultrasound, the combination of 12 h of hydration and 3 s of ultrasound exerted more soluble and hydrophobic SPP, whereas the EAI and ESI of the samples were higher. Notably, the ultrasound-treated SPP can form a stable gel-like emulsion (oil fraction ranging from 70% to 80%). CONCLUSION: The combination of hydration and ultrasound can effectively improve the physicochemical characteristics of SPP as well as its emulsion stability. Sufficient hydration is a cost-effective method for facilitating the modification of proteins by ultrasound treatment. © 2024 Society of Chemical Industry.


Assuntos
Bombyx , Emulsões , Interações Hidrofóbicas e Hidrofílicas , Proteínas de Insetos , Tamanho da Partícula , Pupa , Solubilidade , Animais , Emulsões/química , Bombyx/química , Proteínas de Insetos/química , Pupa/química , Ondas Ultrassônicas , Emulsificantes/química , Água/química
5.
Artigo em Inglês | MEDLINE | ID: mdl-37719135

RESUMO

A novel online real-time video stabilization algorithm (LSstab) that suppresses unwanted motion jitters based on cinematography principles is presented. LSstab features a parallel realization of the a-contrario RANSAC (AC-RANSAC) algorithm to estimate the inter-frame camera motion parameters. A novel least squares based smoothing cost function is then proposed to mitigate undesirable camera jitters according to cinematography principles. A recursive least square solver is derived to minimize the smoothing cost function with a linear computation complexity. LSstab is evaluated using a suite of publicly available videos against state-of-the-art video stabilization methods. Results show that LSstab achieves comparable or better performance, which attains real-time processing speed when a GPU is used.

6.
Nature ; 581(7808): 264-265, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32433616
7.
Rep Prog Phys ; 83(4): 047101, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31923911

RESUMO

Natural visual systems have inspired scientists and engineers to mimic their intriguing features for the development of advanced photonic devices that can provide better solutions than conventional ones. Among various kinds of natural eyes, researchers have had intensive interest in mammal eyes and compound eyes due to their advantages in optical properties such as focal length tunability, high-resolution imaging, light intensity modulation, wide field of view, high light sensitivity, and efficient light management. A variety of different approaches in the broad field of science and technology have been tried and succeeded to duplicate the functions of natural eyes and develop bioinspired photonic devices for various applications. In this review, we present a comprehensive overview of bioinspired artificial eyes and photonic devices that mimic functions of natural eyes. After we briefly introduce visual systems in nature, we discuss optical components inspired by the mammal eyes, including tunable lenses actuated with different mechanisms, curved image sensors with low aberration, and light intensity modulators. Next, compound eye inspired photonic devices are presented, such as microlenses and micromirror arrays, imaging sensor arrays on curved surfaces, self-written waveguides with microlens arrays, and antireflective nanostructures (ARS). Subsequently, compound eyes with focal length tunability, photosensitivity enhancers, and polarization imaging sensors are described.


Assuntos
Biomimética/instrumentação , Olho Artificial , Óptica e Fotônica , Animais , Desenho de Equipamento
8.
Proc Natl Acad Sci U S A ; 113(15): 3982-5, 2016 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-26976565

RESUMO

The ability to acquire images under low-light conditions is critical for many applications. However, to date, strategies toward improving low-light imaging primarily focus on developing electronic image sensors. Inspired by natural scotopic visual systems, we adopt an all-optical method to significantly improve the overall photosensitivity of imaging systems. Such optical approach is independent of, and can effectively circumvent the physical and material limitations of, the electronics imagers used. We demonstrate an artificial eye inspired by superposition compound eyes and the retinal structure of elephantnose fish. The bioinspired photosensitivity enhancer (BPE) that we have developed enhances the image intensity without consuming power, which is achieved by three-dimensional, omnidirectionally aligned microphotocollectors with parabolic reflective sidewalls. Our work opens up a previously unidentified direction toward achieving high photosensitivity in imaging systems.


Assuntos
Olho Artificial , Aumento da Imagem/instrumentação , Aumento da Imagem/métodos , Lentes , Visão Noturna , Animais , Biomimética/métodos , Desenho de Equipamento , Peixes/fisiologia , Luz
9.
Sensors (Basel) ; 19(11)2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31181614

RESUMO

In this paper, we propose a novel multi-view image denoising algorithm based on convolutional neural network (MVCNN). Multi-view images are arranged into 3D focus image stacks (3DFIS) according to different disparities. The MVCNN is trained to process each 3DFIS and generate a denoised image stack that contains the recovered image information for regions of particular disparities. The denoised image stacks are then fused together to produce a denoised target view image using the estimated disparity map. Different from conventional multi-view denoising approaches that group similar patches first and then perform denoising on those patches, our CNN-based algorithm saves the effort of exhaustive patch searching and greatly reduces the computational time. In the proposed MVCNN, residual learning and batch normalization strategies are also used to enhance the denoising performance and accelerate the training process. Compared with the state-of-the-art single image and multi-view denoising algorithms, experiments show that the proposed CNN-based algorithm is a highly effective and efficient method in Gaussian denoising of multi-view images.

10.
J Food Sci Technol ; 56(6): 2855-2862, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31205341

RESUMO

This study aimed to develop gluten-free protein-enriched corn snack chips and evaluate their physical properties and in vitro estimated glycemic index. Flours containing yellow corn and soybean flours, and soy protein isolate (in a proportion of 2.5:1.0:1.0 by weight respectively), cellulose gum, salt, and baking powder were homogeneously mixed followed by the addition of water and kneaded to form a dough. Response surface methodology was used to optimize baking powder levels (0-2.0%), dough sheet thickness (0.7-1.7 mm), and baking time (6-12 min) of the chips baked at 160 °C. Dough sheet thickness and baking time had significant effect on all the examined physical properties (water activity ranged from 0.15 to 0.71, hardness ranged from 377 to 2105 g, and browning index ranged from 38.4 to 60.7) (P < 0.05) except fracturability. However, all the variables had a significant quadratic effect on the fracturability (ranged from 1 to 23 peaks) of the chips (P < 0.01). The chips prepared from 1.2% baking powder, 1.2 mm dough sheet thickness, and baked for 9.0 min were considered the best and were significantly lower in the estimated GI value (48.8) (P < 0.05) when compared to non-soy corn chips (75.0). These baked protein-enriched corn chips developed could be considered as protein-rich and low glycemic index healthy snacks.

12.
J Microelectromech Syst ; 27(3): 380-382, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30559592

RESUMO

This letter reports on the fabrication, simulation and characterization of conformal antireflective black-silicon (BSi) nanowires on a 3D silicon structure. The BSi nanostructures were formed on various facets of a 3D Si structure including sharp tips and sidewalls using a metal-assisted chemical (MAC) etching process. The conformal BSi design was simulated using FDTD Lumerical software. The antireflection capability was indicated by the quantified reduction in normalized intensity after image processing of diffraction patterns. An optical iris of 1.00-mm circular aperture with conformal BSi nanowires was fabricated and characterized to demonstrate the anti-reflectivity capability at two visible wavelengths of 532 and 633 nm. The iris showed a significant reduction in glare around its Airy disc, up to 3× smaller than the same one but without the BSi nanostructures.

13.
Sensors (Basel) ; 18(7)2018 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-30011930

RESUMO

An optimal camera placement problem is investigated. The objective is to maximize the area of the field of view (FoV) of a stitched video obtained by stitching video streams from an array of cameras. The positions and poses of these cameras are restricted to a given set of selections. The camera array is designed to be placed inside the abdomen to support minimally invasive laparoscopic surgery. Hence, a few non-traditional requirements/constraints are imposed: Adjacent views are required to overlap to support image registration for seamless video stitching. The resulting effective FoV should be a contiguous region without any holes and should be a convex polygon. With these requirements, traditional camera placement algorithms cannot be directly applied to solve this problem. In this work, we show the complexity of this problem grows exponentially as a function of the problem size, and then present a greedy polynomial time heuristic solution that approximates well to the globally optimal solution. We present a new approach to directly evaluate the combined coverage area (area of FoV) as the union of a set of quadrilaterals. We also propose a graph-based approach to ensure the stitching requirement (overlap between adjacent views) is satisfied. We present a method to find a convex polygon with maximum area from a given polygon. Several design examples show that the proposed algorithm can achieve larger FoV area while using much less computing time.

14.
J Food Sci Technol ; 55(3): 891-898, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29487430

RESUMO

Sorghum is a gluten-free grain and more attention has been given to the nutritional properties and recently its usage as a wheat replacement in food products. In the present work, protein-enriched sorghum based snack chips, prepared from sorghum meal with soy protein isolates and soy flour to meet the final protein content of 35.7%, were produced. The effect of varying baking powder (1.5-2.5%), dough sheet thickness (0.7-1.7 mm), and baking time (6-12 min) on the physical properties of the snack chips was investigated using a central composite design of response surface methodology. Under baking temperature of 160 °C, with baking powder added, the water activity and puffiness of chips significantly increased. Baking time was the most significant factor for all the parameters detected except for puffiness. The optimized conditions of preparing protein-enriched sorghum chips were baking powder 2.5%, dough sheet thickness 0.7 mm, and baking time 7.66 min. The estimated glycemic index (eGI) of the protein-enriched sorghum chips (eGI = 59.8) was significantly lower than soybean-free sorghum chips. The gluten-free protein-enriched sorghum chips developed could be considered as protein rich with lower intermediate-glycemic index classified healthy snacks and potential commercialization.

15.
J Microelectromech Syst ; 26(5): 1122-1131, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29606846

RESUMO

We demonstrate the design methodology, geometrical analysis, device fabrication, and testing of a double-sided design (DSD) of tunable-focus dielectrophoretic liquid miniature lenses. This design is intended to reduce the driving voltage for tuning the lens, utilizing a double-sided electrode design that enhances the electric field magnitude. Fabricated devices were tested and measurements on a goniometer showed changes of up to 14° in the contact angle when the dielectrophoretic force was applied under 25 Vrms. Correspondingly, the back focal length of the liquid lens changed from 67.1 mm to 14.4 mm when the driving voltage was increased from zero to 25 Vrms. The driving voltage was significantly lower than those previously reported with similar device dimensions using single-sided electrode designs. This design allows for a range of both positive and negative menisci dependent on the volume of the lens liquid initially dispensed.

16.
J Microelectromech Syst ; 26(2): 305-307, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29038640

RESUMO

We demonstrate an electrowetting-based liquid optical phase shifter. The phase shifter consists of two immiscible liquid layers with different refractive indices. Sandwiched between the two liquids is a rigid membrane that moves freely along the optical axis and supported by a compliant surround. When applied with a pressure, the thicknesses of both liquid layers change, which induces a difference in optical path, resulting in a phase shift. A miniaturized electrowetting-based actuator is used to produce hydraulic pressure. A multi-layered SU8 bonded structure was fabricated. A phase shift of 171° was observed when the device was incorporated in a Mach-Zehnder interferometer and driven with 100 V.

17.
J Microelectromech Syst ; 25(2): 304-310, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31983867

RESUMO

This work presents the use of a tunable-focus thermo-responsive hydrogel based liquid lens in combination with an objective lens to achieve remote axial focusing in a conventional microscopy. The goal of this design is to eliminate image distortion due to sample vibrations caused by mechanical stage scanning. This approach reduces the mechanical complexity and power consumption due to the use of electrically tunable lenses while achieving a two-fold increase in the axial scanning range. The merits of the proposed design were demonstrated by characterizing a customized microscope system over a scanning range of 1700 µm. A lateral resolution of 2 µm was obtained consistently throughout the scanning range. Healthy Spodoptera frugiperda Sf21 insect cells imaging was used to verify the depth scanning ability and the resolution of our remote focusing microscope system.

18.
J Micromech Microeng ; 26(1)2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32773966

RESUMO

In this paper, we introduce an electrode design for electrohydrodynamically actuated liquid microlenses. The effective electrode areal density radially increases which results in centering of the liquid tunable microlens with a planar device structure. A model was developed to demonstrate the centering mechanism of the liquid microlens. 3D electrostatic simulation was conducted and validity of the idea was examined. A simple fabrication process that uses readily available SU-8 as the insulator was developed and surface modified, hydrophobic SU-8 layer was used to construct the microlens. Focal length of the microlens was measured to vary from 10.1 mm to 5.8 mm as the voltage varied from zero to 100 V.

19.
Small ; 10(15): 3050-7, 2014 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-24764227

RESUMO

In nature, reflecting superposition compound eyes (RSCEs) found in shrimps, lobsters and some other decapods are extraordinary imaging systems with numerous optical features such as minimum chromatic aberration, wide-angle field of view (FOV), high sensitivity to light and superb acuity to motion. Here, we present life-sized, large-FOV, wide-spectrum artificial RSCEs as optical imaging devices inspired by the unique designs of their natural counterparts. Our devices can form real, clear images based on reflection rather than refraction, hence avoiding chromatic aberration due to dispersion by the optical materials. Compared to imaging at visible wavelengths using conventional refractive lenses of comparable size, our artificial RSCEs demonstrate minimum chromatic aberration, exceptional FOV up to 165° without distortion, modest aberrations and comparable imaging quality without any post-image processing. Together with an augmenting cruciform pattern surrounding each focused image, our large-FOV, wide-spectrum artificial RSCEs possess enhanced motion-tracking capability ideal for diverse applications in military, security, medical imaging and astronomy.


Assuntos
Biomimética/instrumentação , Olho Composto de Artrópodes/fisiologia , Imageamento Tridimensional/instrumentação , Lentes , Fotometria/instrumentação , Animais , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Aumento da Imagem/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
J Power Sources ; 2482014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24327797

RESUMO

To study the fundamental energy storage mechanism of photovoltaically self-charging cells (PSCs) without involving light-responsive semiconductor materials such as Si powder and ZnO nanowires, we fabricate a two-electrode PSC with the dual functions of photocurrent output and energy storage by introducing a PVDF film dielectric on the counterelectrode of a dye-sensitized solar cell. A layer of ultrathin Au film used as a quasi-electrode establishes a shared interface for the I-/I3- redox reaction and for the contact between the electrolyte and the dielectric for the energy storage, and prohibits recombination during the discharging period because of its discontinuity. PSCs with a 10-nm-thick PVDF provide a steady photocurrent output and achieve a light-to-electricity conversion efficiency (η) of 3.38%, and simultaneously offer energy storage with a charge density of 1.67 C g-1. Using this quasi-electrode design, optimized energy storage structures may be used in PSCs for high energy storage density.

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