Search

The field-of-view (FOV), depth of field, and resolution of conventional microscopes are constrained by each other; therefore, a zoom function is required. Traditional zoom methods lose real-time performance and have limited information throughput, severely limiting their application, especially in three-dimensional dynamic imaging and large-amount or large-size sample scanning. Here, an adaptive multiscale (AMS) imaging mechanism combining the benefits of liquid lenses and multiscale imaging techniques is proposed to realize the functions of fast zooming, wide working distance (WD) range and large FOV on a self-developed AMS microscope. The design principles were revealed. Moreover, a nonuniform-distortion-correction algorithm and a composite patching algorithm were designed to improve image quality. The continuous tunable magnification range of the AMS microscope is from 9× to 18×, with the corresponding FOV diameters and resolution ranging from 2.31 to 0.98 mm and from 161 to 287 line-pairs/mm, respectively. The extended WD range is 0.8 mm and the zoom response time is 38 ms. Experiments demonstrated the advantages of the proposed microscope in pathological sample scanning, thick-sample imaging, microfluidic process monitoring, and the observation of living microorganisms. The proposed microscope is the first step towards zoom multiscale imaging technology and is expected to be applied in life sciences, medical diagnosis, and industrial detection.

Somatostatin, a naturally produced neuroprotective peptide, depresses excitatory neurotransmission and exerts anti-proliferative and anti-inflammatory effects on the retina. In this review, we summarize the progress of somatostatin treatment of diabetic retinopathy through analysis of relevant studies published from February 2019 to February 2023 extracted from the PubMed and Google Scholar databases. Insufficient neuroprotection, which occurs as a consequence of declined expression or dysregulation of retinal somatostatin in the very early stages of diabetic retinopathy, triggers retinal neurovascular unit impairment and microvascular damage. Somatostatin replacement is a promising treatment for retinal neurodegeneration in diabetic retinopathy. Numerous pre-clinical and clinical trials of somatostatin analog treatment for early diabetic retinopathy have been initiated. In one such trial (EUROCONDOR), topical administration of somatostatin was found to exert neuroprotective effects in patients with pre-existing retinal neurodysfunction, but had no impact on the onset of diabetic retinopathy. Overall, we concluded that somatostatin restoration may be especially beneficial for the growing population of patients with early-stage retinopathy. In order to achieve early prevention of diabetic retinopathy initiation, and thereby salvage visual function before the appearance of moderate non-proliferative diabetic retinopathy, several issues need to be addressed. These include the needs to: a) update and standardize the retinal screening scheme to incorporate the detection of early neurodegeneration, b) identify patient subgroups who would benefit from somatostatin analog supplementation, c) elucidate the interactions of somatostatin, particularly exogenously-delivered somatostatin analogs, with other retinal peptides in the context of hyperglycemia, and d) design safe, feasible, low cost, and effective administration routes.

Diabetic retinopathy (DR) is a prevalent complication of diabetes that can lead to vision loss. The chronic hyperglycemia associated with DR results in damage to the retinal microvasculature. Müller cells, as a kind of macroglia, play a crucial role in regulating the retinal vascular microenvironment. The objective of this study was to investigate the role of signal-induced proliferation-associated protein 1 (SIPA1) in regulating angiogenesis in Müller cells. Through proteomics, database analysis, endothelial cell function tests, and Western blot detection, we observed an up-regulation of SIPA1 expression in Müller cells upon high glucose stimulation. SIPA1 expression contributed to VEGF secretion in Müller cells and regulated the mobility of retinal vascular endothelial cells. Further investigation of the dependence of SIPA1 on VEGF secretion revealed that SIPA1 activated the phosphorylation STAT3, leading to its translocation into the nucleus. Overexpression of SIPA1 combined with the STAT3 inhibitor STATTIC demonstrated the regulation of SIPA1 in VEGF expression, dependent on STAT3 activation. These findings suggest that SIPA1 promotes the secretion of pro-angiogenic factors in Müller cells by activating the STAT3 signaling pathway, thereby highlighting SIPA1 as a potential therapeutic target for DR.

Abstract To assess and evaluate Chitosan‐Metamizole nanoparticles for fracture healing and analgesic potential, nanoparticles were formulated using the ionotropic gelation method. The nanoparticles were evaluated for particle size, zeta potential, polydispersity index, loading efficiency, surface characteristics and drug release properties. The analgesic activity was determined in carrageenan‐induced arthritic male Wister rats. Further fracture healing potency, mechanical testing, radiographic examination and bone histology of the femur were studied. The drug loading efficiency of 11.38%–17.45%, particle size of 140–220 nm, and zeta potential of 19.12–23.14 mV were observed with a spherical, smooth appearance. Nanoparticles showed sustained release behaviour over a longer period. Nearly 4‐fold inhibition of oedema was observed in animals treated with nanoparticles with excellent fracture healing potential. The femurs treated with nanoparticles required greater force to fracture. Nanoparticles significantly improved the strength and healing process. Histopathological studies showed the potential of nanoparticles in the healing process. The study confirmed the potential of nanoparticles in fracture healing and enhancement of analgesic activity.

BackgroundHealth literacy plays an important role in preventing and managing chronic diseases, while low levels of health literacy among ethnic minorities are a major manifestation of health inequities. We believe that before effective health literacy intervention strategies, it is preferable to understand the features of health literacy among ethnic minorities. The present study firstly updated insights on health literacy among ethnic minorities by investigating the knowledge, attitude, and practice (KAP) profile of common chronic diseases in ethnic minority areas, and secondly discussed the KAP profiles in detail to inspire future health education interventions.MethodsA cross-sectional, health-literacy-sensitive study was conducted in China's typical ethnic minority area. Participants included 801 adult residents who lived in the ethnic minority area. The primary outcome was participant scores on the KAP questionnaire of common chronic diseases, followed by latent profile analysis to identify participants with similar KAP score patterns and determine whether membership in specific groups was associated with demographic or clinical characteristics.ResultsThe participants included 496 ethnic minorities (61.9%) and 305 Han Chinese (38.1%). Three-profile solution was determined after the latent profile analysis: incomplete transfer [I.T.] (n = 215), better practice [B.P.] (n = 301), and average [A.V.] (n = 285). IT group (26.84%) was characterized by the highest level of knowledge and attitude toward common chronic diseases and below average level for practice. Participants in B.P. group performed poorly in both knowledge and attitude toward common chronic diseases but had the highest level of practice. A.V. group reflected average knowledge, attitude, and practice toward common chronic diseases among three subgroups. Ethnic minorities were the dominant population in A.V. group (68.8%). Compared with other groups, the A.V. group contained the largest proportions of married participants (84.2%), participants with no formal education (46.7%), and high annual out-of-pocket medical expense (33.3%).ConclusionA more specific and nuanced understanding of minority health literacy can enable service providers to provide more effective health education to their recipients, thereby improving health inequities.

In this work, the stability of unpackaged CdTe solar cells with different configurations was investigated according to the International Electrotechnical Commission IEC 61215-2016. The measurements of thermal cycling from -40°C to +85°C and 24-hour temperature cycling from -40°C to +85°C withstanding the effects of 20-hour penetration of 85°C were carried out in CdS/CdTe solar cells with structures of FTO/CdS/CdTe/Au, FTO/CdS/CdTe/back contact/Au, and FTO/MZO/CdS/CdTe/back contact/Au, respectively. The performances of these cells before and after the thermal aging experiments were investigated by using light and dark I‐V together with C‐V. The results reveal varied performance degradation before and after thermal aging in the cells with different structures. Among these, the most deteriorated device is the one without back contact (BC), whose efficiency decreased by 25.12% after thermal cycling accompanying an obvious roll-over phenomenon when forward bias was greater than open circuit voltage. On the contrary, the reduction in the efficiency was about 16.80% in the case cells with BC, and the roll-over phenomenon was not so significant. Furthermore, for the devices with optimized front contact of FTO/MZO, the thermal stability was improved obviously. Interestingly, short-circuit current density associated with the carrier concentration of cells remained relatively small variations compared with the change of Voc and fill factor. All the results indicated that an efficient back contact layer and an optimized front electrode were the indispensable structural elements to attain high stabilization in the CdS/CdTe solar cells.

A fast calculation method for a full parallax high-resolution hologram is proposed based on elemental light field image (EI) rendering. A 3D object located near the holographic plane is firstly rendered as multiple EIs with a pinhole array. Each EI is interpolated and multiplied by a divergent sphere wave and interfered with a reference wave to form a hogel. Parallel acceleration is used to calculate the high-resolution hologram because the calculation of each hogel is independent. A high-resolution hologram with the resolution of 200,000 × 200,000 pixels is calculated within only eight minutes. Full parallax high-resolution 3D displays are realized by optical reconstructions.

We propose a dual-view integral imaging 3D display based on a multiplexed lens-array holographic optical element (MHOE). A MHOE is a volume holographic optical element obtained by multiplexing technology, which can be used for dual-view integral imaging 3D display due to the angle selectivity of the volume HOE. In the fabrication of the MHOE, two spherical wavefront arrays with different incident angles are recorded using photopolymer material. In the reconstruction, two projectors are used to project the elemental image arrays (EIA) with corresponding angles for two viewing zones. We have developed a prototype of the dual-view integral imaging display. The experimental results demonstrate the correctness of the theory.

In this paper, we propose a reflective augmented reality (AR) display system based on integral imaging (II) using a mirror-based pinhole array (MBPA). The MBPA, obtained by punching pinholes on a mirror, functions as a three-dimensional (3D) imaging device, as well as an image combiner. The pinhole array of MBPA can realize a pinhole array-based II display, while the mirror of MBPA can image the real objects, so as to combine the images of the real objects with the reconstructed 3D images. The structure of the proposed reflective AR display is very simple, and only a projection system or a two-dimensional display screen is needed to combine with the MBPA. In our experiment, a 25cm × 14cm sized AR display was built up, a combination of a 3D virtual image and a real 3D object was presented by the proposed AR 3D display. The proposed device could realize an AR display of large size due to its compact form factor and low weight.

The application of thinner cadmium sulfide (CdS) window layer is a feasible approach to improve the performance of cadmium telluride (CdTe) thin film solar cells. However, the reduction of compactness and continuity of thinner CdS always deteriorates the device performance. In this work, transparent Al2O3 films with different thicknesses, deposited by using atomic layer deposition (ALD), were utilized as buffer layers between the front electrode transparent conductive oxide (TCO) and CdS layers to solve this problem, and then, thin-film solar cells with a structure of TCO/Al2O3/CdS/CdTe/BC/Ni were fabricated. The characteristics of the ALD-Al2O3 films were studied by UV–visible transmittance spectrum, Raman spectroscopy, and atomic force microscopy (AFM). The light and dark J–V performances of solar cells were also measured by specific instrumentations. The transmittance measurement conducted on the TCO/Al2O3 films verified that the transmittance of TCO/Al2O3 were comparable to that of single TCO layer, meaning that no extra absorption loss occurred when Al2O3 buffer layers were introduced into cells. Furthermore, due to the advantages of the ALD method, the ALD-Al2O3 buffer layers formed an extremely continuous and uniform coverage on the substrates to effectively fill and block the tiny leakage channels in CdS/CdTe polycrystalline films and improve the characteristics of the interface between TCO and CdS. However, as the thickness of alumina increased, the negative effects of cells were gradually exposed, especially the increase of the series resistance (Rs) and the more serious “roll-over„ phenomenon. Finally, the cell conversion efficiency (η) of more than 13.0% accompanied by optimized uniformity performances was successfully achieved corresponding to the 10 nm thick ALD-Al2O3 thin film.

Phase measuring deflectometry (PMD) with structured light projection and phase-shifting technique is a highly accurate optical surface measuring method based on the law of reflection. Generally, for surface shape measurement of transparent planar elements, PMD suffers from parasitic reflection. To avoid the unexpected effect of parasitic reflection, a method based on fringe frequency tuning and Fourier-transform is introduced. Numerical simulations and experiments are both conducted to evaluate the performance of the proposed method. Experiment results are shown. Surface figures measured using the proposed method are compared with those measured using traditional phase-shifting algorithm and Fizeau interferometer. Both an optical planar element with a thickness of 24.5 mm and a planar window glass with a thickness of 10 mm are measured. For the optical element, the proposed method is accurate and the measurement error is within 200-nm PV. For window glass, the proposed method yields a better surface figure than the traditional phase-shifting algorithm does. [ABSTRACT FROM AUTHOR]

Action recognition in videos is receiving extensive research interest due to its wide applications. This task needs to assign a specific action class for each video. In this paper, we study the problem of action similarity labeling (ASLAN) that is to verify whether two action videos present the same type of action or not. We show that both Fisher vector (FV) and vector of locally aggregated descriptors (VLAD) with dense trajectory features can achieve state-of-the-art performance on the ASLAN benchmark. Our main contribution is to develop a large margin dimensionality reduction (LMDR) method to compress high-dimensional FV and VLAD. Specially, we leverage the hinge loss objective function and stochastic gradient descent to optimize the discriminative projection matrix of these vectors. Extensive experiments on the ASLAN dataset indicate that our LMDR method not only reduces the dimension significantly but also improves the verification performance. [ABSTRACT FROM AUTHOR]

To obtain a hollow variable biconical laser beam (HVBLB), a CO2 laser having a hollow circular-truncated cone resonator (HCTCR) is presented. This HCTCR comprises a rotationally symmetric total-reflecting concave mirror at the bottom, a rotationally symmetric part-reflecting convex mirror at the top, and a hollow circular-truncated cone discharge tube at the middle. The cross section of this generated biconical laser beam changes from annulus to circular to annulus and the size of this cross section from big to small to large as the propagation distance increases. So, a kind of laser beam with variable center intensity from zero to peak value to zero is obtained and is known as HVBLB. Due to the inclusion of part of the hollow laser beam (HLB) and solid laser beam, this HVBLB requires no additional beam-shaping element and has broad applications such as optical trapping and commercial manufacturing. [ABSTRACT FROM AUTHOR]