21 research outputs found
New insights into Sirt1: potential therapeutic targets for the treatment of cerebral ischemic stroke
Ischemic stroke is one of the main causes of mortality and disability worldwide. However, the majority of patients are currently unable to benefit from intravenous thrombolysis or intravascular mechanical thrombectomy due to the limited treatment windows and serious complications. Silent mating type information regulation 2 homolog 1 (Sirt1), a nicotine adenine dinucleotide-dependent enzyme, has emerged as a potential therapeutic target for ischemic stroke due to its ability to maintain brain homeostasis and possess neuroprotective properties in a variety of pathological conditions for the central nervous system. Animal and clinical studies have shown that activation of Sirt1 can lessen neurological deficits and reduce the infarcted volume, offering promise for the treatment of ischemic stroke. In this review, we summarized the direct evidence and related mechanisms of Sirt1 providing neuroprotection against cerebral ischemic stroke. Firstly, we introduced the protein structure, catalytic mechanism and specific location of Sirt1 in the central nervous system. Secondly, we list the activators and inhibitors of Sirt1, which are primarily divided into three categories: natural, synthetic and physiological. Finally, we reviewed the neuroprotective effects of Sirt1 in ischemic stroke and discussed the specific mechanisms, including reducing neurological deficits by inhibiting various programmed cell death such as pyroptosis, necroptosis, ferroptosis, and cuproptosis in the acute phase, as well as enhancing neurological repair by promoting angiogenesis and neurogenesis in the later stage. Our review aims to contribute to a deeper understanding of the critical role of Sirt1 in cerebral ischemic stroke and to offer novel therapeutic strategies for this condition
Adsorption characteristics of metal modified AlNNT on partial discharge air decomposition components in switchgear
The online detection of partial discharge air decomposition components in switchgear is an effective means to monitor the running state of switchgear. Based on first principles, the adsorption and sensing properties of Pd, Co, Rh, Pt, and Au modified AlNNT for partial discharge air decomposition components in switchgear were studied, aiming to find materials with excellent sensitivity and selectivity. The adsorption energy, density of states, differential charge density, and molecular orbital theory were calculated, and the modification process and gas adsorption process were analyzed. The results show that AlNNT doped with Pd, Co, Rh, Pt, and Au has a good adsorption capacity for NO2 and NO. In addition, the doping of different metal atoms also shows other gas-sensitive properties to the gas molecules, which provides a feasible method to identify the decomposition components in the mixed characteristic decomposition gas
Patent Propensity in Small Technology-based Firms: Evidence from Zhongguancun Science Park
Using a survey administered in Zhongguancun Science Park in Beijing, China, this paper investigates the impact of R&D personnel-related intellectual property management practices on the patent propensity of small technology-based firms. It is found that R&D personnel-related management practices, including training and reward mechanisms, are effective in enhancing a firm's willingness to patent. In particular, we find that reward mechanisms can negatively moderate the effect of size on a firm's willingness to patent. One implication that emerged from the analysis is that a small firm can counteract its size disadvantage in patenting by introducing a well-developed reward mechanism. Copyright (c) 2010 The Authors Journal compilation (c) 2010 Institute of World Economics and Politics, Chinese Academy of Social Sciences.
A New Control Method Based on DTC and MPC to Reduce Torque Ripple in SRM
This paper proposes a new control strategy to reduce torque ripple in a switched reluctance motor (SRM). The flux linkage in this paper is related to model predictive flux control (MPFC). In addition, the torque hysteresis remained in the system is similar to direct torque control (DTC) and direct instantaneous torque control (DITC). The candidate voltage vectors (VVs) are selected from the torque hysteresis and the cost function is designed for the flux linkage minimization to select the best VV from candidate VVs. The advantages, as well as the improvement prospects for these methods, are discussed in details. Performance for torque ripple in steady state and the robustness in the transient state are evaluated in this paper under the simulation and experimental results, and also the possibility and some advice for model predictive control (MPC) applied to an SRM are indicated. The experimental result for the new method is carried out on a three-phase 12/8 poles SRM with the analysis of torque ripple compared to a DTC and DITC
A Novel Framework for Automation Technology Based on Machine Vision and Robotics in Electrical Power Inspection Processing
As a well-known support, computer vision is a powerful factor to improve the application and development of the electronic system. Whether the power system can operate safely and stably can greatly influence the deduction of providence. All types of electric swinging devices are easily disturbed by various factors during the assistance operation. The ubiquitous power system that operates everywhere becomes extremely small once the electrical equipment is abandoned. For the current complexity system, if the old-fashioned hand-written visual monitoring system is still used, not only will their ability fails to meet the requirements but also the number of cumbersome, important, and financial context will be unsatisfactory. It is natural to reason about some problems. Serious problems are due to incompetent human investigation. Issues are not optimally handled during this period. The application of Coach Ken technology can fully utilize machine vision technology to analyze the salient data and identify dominant devices that support shape vision. Meanwhile, it can truly realize the supervision system of perception and machine control. In view of this, we in this work mainly expound the artifact recognition technology supported by machine vision reproduction. Besides, we disassemble the composition method of the electric power supply recognition system supported by machine vision parallel, in order to enhance the future work
Control strategy of UPFC based on power transfer distribution factor
In practical engineering application, trial method is widely used to determine the control value of unified power flow controller (UPFC in short). Since the calculation is based on offline typical data, the trial method is inefficient and less accurate, which could not adjust to the changing operating conditions. In order to make up for the deficiency, this paper proposes a novel UPFC control strategy based on power transfer distribution factors. First, the anticipated line tripping fault throughout the grid is scanned and the N − 1 overload lines are marked. Then, in regard to each overload condition, a certain UPFC control value is calculated based on power transfer distribution factors. The anticipated control list could be formed and updated according to online EMS data. When a line tripping fault is detected, simply by searching the control list, a condition could be matched and the UPFC could immediately be activated to eliminate the line overload. This method mentioned above could provide decision-making support to power-grid dispatching institutions. The results of a simulation example shows that the method is efficient and utilisable
Resveratrol Inhibits Activation of Microglia after Stroke through Triggering Translocation of Smo to Primary Cilia
Activated microglia act as a double-edged sword for stroke. In the acute phase of stroke, activated microglia might deteriorate neurological function. Therefore, it is of great clinical transforming potential to explore drugs or methods that can inhibit abnormal activation of microglia in the acute phase of stroke to improve neurological function after stroke. Resveratrol has a potential effect of regulating microglial activation and anti-inflammation. However, the molecular mechanism of resveratrol-inhibiting microglial activation has not been fully clarified. Smoothened (Smo) belongs to the Hedgehog (Hh) signaling pathway. Smo activation is the critical step that transmits the Hh signal across the primary cilia to the cytoplasm. Moreover, activated Smo can improve neurological function via regulating oxidative stress, inflammation, apoptosis, neurogenesis, oligodendrogenesis, axonal remodeling, and so on. More studies have indicated that resveratrol can activate Smo. However, it is currently unknown whether resveratrol inhibits microglial activation via Smo. Therefore, in this study, N9 microglia in vitro and mice in vivo were used to investigate whether resveratrol inhibited microglial activation after oxygen-glucose deprivation/reoxygenation (OGD/R) or middle cerebral artery occlusion/reperfusion (MCAO/R) injury and improved functional outcome via triggering translocation of Smo in primary cilia. We definitively found that microglia had primary cilia; resveratrol partially inhibited activation and inflammation of microglia, improved functional outcome after OGD/R and MCAO/R injury, and triggered translocation of Smo to primary cilia. On the contrary, Smo antagonist cyclopamine canceled the above effects of resveratrol. The study suggested that Smo receptor might be a therapeutic target of resveratrol for contributing to inhibit microglial activation in the acute phase of stroke
Digital nanophotonics: the highway to the integration of subwavelength-scale photonics
Nanophotonic devices with high densities are extremely attractive because they can potentially merge photonics and electronics at the nanoscale. However, traditional integrated photonic circuits are designed primarily by manually selecting parameters or employing semi-analytical models. Limited by the small parameter search space, the designed nanophotonic devices generally have a single function, and the footprints reach hundreds of microns. Recently, novel ultra-compact nanophotonic devices with digital structures were proposed. By applying inverse design algorithms, which can search the full parameter space, the proposed devices show extremely compact footprints of a few microns. The results from many groups imply that digital nanophotonics can achieve not only ultra-compact single-function devices but also miniaturized multi-function devices and complex functions such as artificial intelligence operations at the nanoscale. Furthermore, to balance the performance and fabrication tolerances of such devices, researchers have developed various solutions, such as adding regularization constraints to digital structures. We believe that with the rapid development of inverse design algorithms and continuous improvements to the nanofabrication process, digital nanophotonics will play a key role in promoting the performance of nanophotonic integration. In this review, we uncover the exciting developments and challenges in this field, analyse and explore potential solutions to these challenges and provide comments on future directions in this field