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In this study Ginkgo biloba leaves (GBL) decoction and commercial capsules were digested using an in vitro model. Thirty-six active compounds were identified and quantified by HPLC-ESI-MS analysis based on the MS/MS patterns (precursor ions and product ions) and retention times, in comparison with reference standards. Most compounds in GBL showed a significant decrease during intestinal digestion, with an exception of vanillic acid and biflavonoids. Bioaccessibility values of chemical compositions varied between decoction and capsules samples. Also, significant reductions of total flavonoids and total phenolic content was observed after in vitro digestion. Both, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazo-line-6-sulfonic acid (ABTS) scavenging capacity decreased after gastric digestion, but increased during intestinal digestion. Nevertheless, different behaviour was observed in reducing antioxidant power (FRAP) assay. Compared to the pH of digestion, the influence of digestive enzymes on the chemical composition and antioxidant activity of GBL was relatively minor. Overall, these results may help provide a valid foundation for further investigations on bioactive compounds and the pharmacodynamics of GBL.

Background. Hypoglycemia is a dangerous side effect of intensive glucose control in diabetes. Even though it leads to adverse cardiovascular events, the effects of hypoglycemia on vascular biology in diabetes have not been adequately studied. Methods. Aged Sprague-Dawley rats were fed a high-fat diet and given streptozotocin to induce type 2 diabetes mellitus (T2DM). Acute and recurrent hypoglycemia were then induced by glucose via insulin administration. Vascular function, oxidative stress, and pyroptosis levels in aortic tissue were assessed by physiological and biochemical methods. Results. Hypoglycemia was associated with a marked decrease in vascular function, elevated oxidative stress, and elevated pyroptosis levels in the thoracic aorta. The changes in oxidative stress and pyroptosis were greater in rats with recurrent hypoglycemia than in those with acute hypoglycemia. Conclusions. Hypoglycemia impaired vascular function in aged rats with T2DM by inducing pyroptosis. The extent of injury increased with the duration of blood glucose fluctuation.

As the key components of sealing applications, rubber seals are subject to complicated environmental conditions during the service lifetime. In this study, the aging of three typical rubber materials, ethylene–propylene–diene monomer rubber, liquid silicone rubber, and fluorine rubber, was tested under different high- and low-temperature cycle aging environments. The experimental results confirm that the reciprocating temperature cycle causes a type of fatigue failure, which could result in an increase in the rubber compression set. In addition, a novel accelerated aging test method was proposed based on the dominant damage mechanism of rubber material caused by the temperature cycle treatments. Based on this method, the long-term aging test results of rubber samples under high- and low-temperature cycle conditions can be predicted. This method could significantly shorten the aging test time and reduce the test cost.

Littrow diffraction, the ability to reflect light back along incident direction, is a key functionality of retroreflectors, exhibiting wide applications in nanophotonics. However, retroreflectors have hitherto low working efficiencies and narrow bandwidths, and work only for a specific polarization, being unfavorable for integration-optics applications. Here, we propose a type of metagrating consisting of an all-dielectric Bragg reflector and a periodic metasurface with freeform-shaped dielectric resonators, which enables broadband depolarized perfect Littrow diffraction at optical frequencies. The physics is governed by exact cancellations of specular reflections contributed by two Bragg modes in metagratings, enabled by careful structural optimization to yield the desired reflection-phase difference of Bragg modes within a wide frequency band and for two polarizations. As a proof of concept, we experimentally demonstrate retroreflections with unpolarized absolute efficiency higher than 98% (99% in design) at 1030–1090 nm using multilayer freeform metagratings. Our results pave the way for numerous applications based on high-efficiency Littrow diffraction (e.g., spectral laser beam combining), which is not bonded to a specific polarization or frequency.

Diabetes exacerbates vascular injury by triggering endothelial dysfunction. Endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) both play major roles in endothelial dysfunction. However, effects of hypoglycaemia, the main complication of the insulin therapy to the glycemic control in diabetes, on eNOS activity and iNOS expression, and underlying mechanisms in diabetes remain unknown. Hence, we aimed to determine the effects of hypoglycaemia on eNOS activity and iNOS expression in different arterial beds of diabetic rats.Sprague-Dawley rats were subjected to Streptozotocin (STZ) combined with high fat diet (HFD) to induce diabetes and then received insulin injection to attain acute and recurrent hypoglycaemia. Immunoblotting was used to analyse the phosphorylation and O-glycosylation status of eNOS and iNOS level from thoracic aorta and mesenteric artery tissue. Indicators of oxidative stress from plasm were determined, and endothelial-dependent vasodilation was detected via wire myograph system.Hypoglycaemia was associated with a marked increase in eNOS O-GlcNAcylation and decrease in Serine (Ser)-1177 phosphorylation from thoracic aortas and mesenteric arteries. Moreover, hypoglycaemia resulted in elevated phosphorylation of eNOS at Threonine (Thr)-495 site in mesenteric arteries. Besides, changes in these post-translational modifications were associated with increased O-GlcNAc transferase (OGT), decreased phosphorylation of Akt at Ser-473, and increased protein kinase C α subunit (PKCα). iNOS expression was induced in hypoglycaemia. Furthermore, endothelial-dependent vasodilation was impaired under insulin-induced hypoglycaemia, and further in recurrent hypoglycaemia.Conclusively, these findings strongly indicate that hypoglycaemia-dependent vascular dysfunction in diabetes is mediated through altered eNOS activity and iNOS expression. Therefore, this implies that therapeutic modulation of eNOS activity and iNOS expression in diabetics under intensive glucose control may prevent and treat adverse cardiovascular events.

This study critically discusses the role of contract law in improving corporate social responsibility issues in supply chains. It shows that the use of contract law by multinational companies at the top of the supply chain to transfer CSR to their suppliers is widespread and has serious consequences. Moreover, multinational companies are less likely to draft contracts to protect the interests of those at the bottom of the supply chain, making it difficult for contract law to become a more powerful tool for improving CSR in global supply chains.

We introduce a novel concept for the design of functional surfaces of materials: Spatial surface charge engineering. We exploit the concept for an all-solid-state, epitaxial InN/InGaN-on-Si reference electrode to replace the inconvenient liquid-filled reference electrodes, such as Ag/AgCl. Reference electrodes are universal components of electrochemical sensors, ubiquitous in electrochemistry to set a constant potential. For subtle interrelation of structure design, surface morphology and the unique surface charge properties of InGaN, the reference electrode has less than 10 mV/decade sensitivity over a wide concentration range, evaluated for KCl aqueous solutions and less than 2 mV/hour long-time drift over 12 hours. Key is a nanoscale charge balanced surface for the right InGaN composition, InN amount and InGaN surface morphology, depending on growth conditions and layer thickness, which is underpinned by the surface potential measured by Kelvin probe force microscopy. When paired with the InN/InGaN quantum dot sensing electrode with super-Nernstian sensitivity, where only structure design and surface morphology are changed, this completes an all-InGaN-based electrochemical sensor with unprecedented performance.

Diffractive optical elements (DOEs) play an important role in modern optical applications such as spectral and imaging systems, but it is challenging to balance the diffraction efficiency with the working bandwidth. The core issue is controlling the broadband dispersion of all phase units to achieve achromatic 2π-phase modulation in the broadband domain. Here, we demonstrate broadband DOEs utilizing multilayer subwavelength structures with different materials, making it possible to freely control the phase and phase dispersion of the structural units on a much larger scale than monolayer structures. The desired dispersion-control abilities arose due to a dispersion-cooperation mechanism and vertical mode-coupling effects between the top and bottom layers. An infrared design comprised of two vertically concatenated TiO2 and Si nanoantennas separated by a SiO2 dielectric spacer layer was demonstrated. It showed an average efficiency of over 70% in the three-octave bandwidth. This work shows enormous value for broadband optical systems with DOEs such as spectral imaging and augmented reality.

Free-space orbital angular momentum (OAM) communication is considered as one of the potential alternative on-chip optical interconnect solutions. The number of OAM modes determines the capacity of high-speed communication. However, existing integrated vortex beam emitters have a constraint relationship between the number of OAM modes and the emitter size, rendering it difficult to emit more OAM modes with a small-sized emitter. In view of the above, this study proposes an on-chip ultracompact multimode vortex beam emitter based on vertical modes, which permits more OAM modes without requiring an increase in the size of the emitter. Vertical modes in large-aspect-ratio waveguides are pointed out to enable multimode microrings with small radii because high-order vertical modes can maintain almost the same horizontal wave vector as that of the fundamental mode. Four-mode and five-mode vortex beam emitters with the same radius of 1.5 µm are designed and the effectiveness of these emitters is verified through simulation. Furthermore, a high-efficiency and low-crosstalk approach for high-order vertical mode coupling by varying the waveguide height is presented. This research not only promotes further integration of on-chip optical interconnection, but also provides a new strategy for optical waveguide mode selection in photonic integrated circuits design.

InN/InGaN quantum dots (QDs) are found to establish a nonlinear constant phase element (CPE) response over a wide frequency range, measured by electrochemical impedance spectroscopy (EIS). The intrinsic surface donors together with the near-surface electron accumulation layer form the fractional capacitor. The magnitude of the impedance and the phase angle depend on the QD structural parameters and contact area. Importantly, they consistently change with applied voltage, constituting the nonlinear CPE response. A noise-filtering DC voltmeter with the phase angle as readout is proposed.

A retroreflective grating with a high line density is one of the most desirable optical elements, as it is capable of channeling the reflected light toward the source with high angular resolution. Metagratings can steer the incident light into the desired diffraction order with ultrahigh deflection angle and unitary efficiency. However, in practice, the diffraction efficiency of a metagrating with a small period is very sensitive to the unit cells, thus leading to significant challenges in the fabrication process. In this Letter, a kind of high-efficiency, polarization-insensitive retroreflective metagrating with cascaded nano-optical modes on high-reflection films is proposed. It is found that the conception may increase the fabrication tolerance by a factor of more than two. A 1400-lines/mm metagrating is experimentally realized for the first time, to the best of our knowledge, which shows an excellent broadband diffraction spectrum with 96% efficiency over 50 nm in TE and TM polarization. This proposed novel metagrating will benefit miniature optical systems.

When dealing with complex scenes, human cognitive system can get useful information quickly and accurately. This is because that human visual and auditory systems have the important characteristic of selective attention. In order to simulate and realize this feature, much selective attention computational models have been proposed by scholars in the field of computer vision and auditory, which are of great value and significance to artificial intelligence, video compression, speech processing and other fields. This article provides a review of modelling studies of visual and auditory attention. The deficiency of the current research was provided, together with the future research directions.

A comparative study was performed to investigate how etching methods and parameters affect the properties of

With the development of multi-platform and diversified audio-visual multimedia, new requirements and technical problems have been put forward for the automatic integration and matching of audio and visual. Studies showed that synaesthesia has a solid physiological and psychological basis. As the Chinese traditional culture, Chinese traditional music and Chinese painting are closely connected by the cultural background, aesthetic connotation, spatial consciousness and emotional expression. In this paper, the synaesthesia rule between Chinese traditional music aesthetics and the Chinese painting composition elements was found through the visual synaesthesia experiment, which was verified by the multi-perception experiment. It can provide support for audio-visual interactive aesthetics, audio-visual intelligent matching calculation and music visualization.

HfO2 and SiO2 optical thin films were etched using ion beam etching (IBE), reactive ion etching (RIE) and inductively coupled plasma etching (ICPE) techniques. The influence of reactive gas and ion bombardment energy on the etching rates and surface morphologies of these two coatings was comparatively studied. Low ion bombardment energy with Ar/CHF3 (40/20sccm) realized a preferentially etching of SiO2 with a high rate of 50nm/min, and it almost had no influence of HfO2 coatings.

Temporal fine structure includes temporal envelope and fine structure which also called carrier, and instantaneous frequency is the partial derivative of the carrier. An intrusive reverberant speech quality measurement is investigated with the representation of corresponding instantaneous frequency. A Gammatone filterbank is used to simulate auditory mechanism and a modulation filterbank is used to improve frequency resolution. The mean mutual information between reference and reverberant modulation spectral instantaneous frequency probability distribution is taken as the final measurement score. Experimental results show the proposed method outperforming two benchmark algorithms in some practical application conditions.

In recent years, the automobile industry has developed rapidly and the drivers’ unregulated driving behaviors have caused a lot of traffic safety problems. By using the topic model, this paper can find the relationship between driving pattern with driving behavior and provide technical support for traffic safety. Taking the shortage of the current mainstream topic models pLSA and LDA (Latent Dirichlet Allocation) into account, this paper proposes an improved LDA model with time labels, namely the T-LDA model to identify driving patterns. The experimental results show that the improved model can effectively extract a series of continuous driving behavior characteristic and improve the accuracy of driving pattern recognition.

It is well known that there are many situations where auditory and visual perception cannot be regarded as independent processes. This article aims to explore whether the subjective perception of the auditory spatial size is affected by visual spatial information. Static pictures which reflect different spatial size were used as visual spatial stimuli, and audio signals with different reverberation time were used as auditory spatial stimuli in subjective experiments. Results of visual-auditory mode and auditory-only mode were discussed and compared. Experimental results showed that visual spatial information had significant effect on auditory space perception, especially in judging the medium size of the auditory space. Further analysis indicated that the judgments of auditory spatial size perception were induced by the visual stimuli when judging the large size and small size of the auditory space. What's more, the influence of the subjects' gender and listening experience were analyzed, it was found that there was no significant difference.

Broadband multilayer dielectric gratings (MDGs) with rectangular HfO2 grating profile were realized for the first time using a novel fabrication process that combines laser interference lithography, nanoimprint, atomic layer deposition and reactive ion-beam etching. The laser-induced damage initiating at the grating ridge was mitigated for two reasons. First, the rectangular grating profile exhibits the minimum electric-field intensity (EFI) enhancement inside the grating pillar compared to other trapezoidal profiles. Second, our etching process did not create nano-absorbing defects at the edge of the HfO2 grating where the peak EFI locates, which is unavoidable in traditional fabrication process. The fabricated MDGs showed a high laser induced damage threshold of 0.59J/cm2 for a Ti-sapphire laser with pulse width of 40 fs and an excellent broadband diffraction spectrum with 95% efficiency over 150 nm in TE polarization.