Ischemic stroke caused by arterial occlusion is the most common type of stroke, which is among the most frequent causes of disability and death worldwide. Current treatment approaches involve ...achieving rapid reperfusion either pharmacologically or surgically, both of which are time‐sensitive; moreover, blood flow recanalization often causes ischemia/reperfusion injury. However, even though neuroprotective intervention is urgently needed in the event of stroke, the exact mechanisms of neuronal death during ischemic stroke are still unclear, and consequently, the capacity for drug development has remained limited. Multiple cell death pathways are implicated in the pathogenesis of ischemic stroke. Here, we have reviewed these potential neuronal death pathways, including intrinsic and extrinsic apoptosis, necroptosis, autophagy, ferroptosis, parthanatos, phagoptosis, and pyroptosis. We have also reviewed the latest results of pharmacological studies on ischemic stroke and summarized emerging drug targets with a focus on clinical trials. These observations may help to further understand the pathological events in ischemic stroke and bridge the gap between basic and translational research to reveal novel neuroprotective interventions.
We investigate the shadows and photon spheres of the four-dimensional Gauss–Bonnet black hole with the static and infalling spherical accretions. We show that, for both cases, there always exist ...shadows and photon spheres. The radii of the shadows and photon spheres are independent of the profiles of accretion for a fixed Gauss–Bonnet constant, implying that the shadow is a signature of the spacetime geometry and it is hardly influenced by accretion. Because of the Doppler effect, the shadows of the infalling accretion are found to be darker than in the static case. We also investigate the effect of the Gauss–Bonnet constant on the shadow and photon spheres, and we find that the larger the Gauss–Bonnet constant is, the smaller the radii of the shadow and photon spheres will be. In particular, the observed specific intensity increases as the Gauss–Bonnet constant grows.
Dysfunction and death of neuronal cells are cardinal features of degenerative retinal diseases that are known to arise as the disease progresses. Increasingly evidence suggests that abnormal ...expression of brain‐derived neurotrophic factor (BDNF) may serve as an obligatory relay of the dysfunction and death of neuronal cells in degenerative retinal diseases. Although disorder of BDNF, whether depletion or augmentation, has been connected with neuronal apoptosis and neuroinflammation, the exact mechanisms underlying the effect of impaired BDNF expression on degenerative retinal diseases remain unclear. Here, we present an overview of how BDNF is linked to pathological mechanism of retinal degenerative diseases, summarize BDNF‐based treatment strategies, and discuss possible research perspectives in the future.
Due to the recent expanding interest in two-dimensional layered materials, molybdenum disulfide (MoS2) has been receiving much research attention. Having an ultrathin layered structure and an ...appreciable direct band gap of 1.9 eV in the monolayer regime, few-layer MoS2 has good potential applications in nanoelectronics, optoelectronics, and flexible devices. In addition, the capability of controlling spin and valley degrees of freedom makes it a promising material for spintronic and valleytronic devices. In this review, we attempt to provide an overview of the research relevant to the structural and physical properties, fabrication methods, and electronic devices of few-layer MoS2. Recent developments and advances in studying the material are highlighted.
Iron, ferroptosis, and ischemic stroke Guo, Jun; Tuo, Qing‐zhang; Lei, Peng
Journal of neurochemistry,
20/May , Letnik:
165, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Over 30 million people suffer from the consequences of ischemic stroke. The precise molecular mechanism of neuronal damage during ischemic stroke remains unclear; therefore, the effective treatment ...of post‐ischemic stroke remains a critical challenge. Recently, iron has emerged as a crucial factor in post‐reperfusion injuries, participating in cell peroxidation, excitotoxicity, and a distinctive cell death pathway, namely, ferroptosis. Since iron is tightly regulated in the brain and important for brain functions, the imbalance of its metabolism, including its overload and deficiency, has been shown to impact ischemic stroke outcomes. This review summarizes the current understanding of pathological events associated with iron in ischemic stroke and discusses relevant drug development.
Ischemic stroke caused by arterial occlusion is the most common type of stroke, and it strongly associates with age‐related neurological deficits. Recently, iron has emerged as a crucial factor of neuronal pathology in ischemic stroke. Iron dyshomeostasis leads to brain iron accumulation, and together with the excessive production of free arachidonic acid, insufficient antioxidant supply, they collectively induce lipid peroxidation and ferroptosis during cerebral ischemia/reperfusion. Independently or co‐currently, peripheral iron deficiency also aggravates the cerebral ischemic injury. This review summarizes the current understanding of pathological events associated with iron in ischemic stroke and discusses relevant drug development. ACSL4, acyl‐CoA synthetase long‐chain family member 4; GPx4, glutathione peroxidase 4; LOX, lipoxygenase.
We investigate the effects of quintessence dark energy on the shadows of black hole, surrounded by various profiles of accretions. For the thin-disk accretion, the images of the black hole comprises ...the dark region and bright region, including direct emission, lensing rings and photon rings. Although their details depend on the form of the emission, generically, direct emission plays a major role for the observed brightness of the black hole, while the lensing ring makes a small contribution and the photon ring makes a negligible contribution. The existence of a cosmological horizon also plays an important role in the shadows, since the observer in the domain of outer communications is near the cosmological horizon. For spherically symmetric accretion, static and infalling matters are considered. We find that the positions of photon spheres are the same for both static and infalling accretions. However, the observed specific intensity of the image for infalling accretion is darker than for static accretion, due to the Doppler effect of the infalling motion.
Objectives
The purpose of this study was to introduce a new narrow band imaging (NBI) endoscopic classification for the diagnosis of vocal cord leukoplakia.
Study Design
Case series.
Methods
From ...January 2010 to February 2018, a total of 120 cases of vocal cord leukoplakia were enrolled in this study. The NBI endoscopic system was used to examine the vocal cords. Each lesion was observed by NBI endoscopy and evaluated according to the detailed morphologic findings of intraepithelial papillary capillary loop (IPCL). The superficial IPCL patterns were classified into six types (types I–VI). The differential diagnosis abilities of NBI classification for benign and malignant leukoplakia were investigated.
Results
Out of the 120 cases of vocal cord leukoplakia, 81% (97 of 120) related to benign lesions (including inflammation, epithelial proliferation, hyperkeratosis, dyskeratosis, mild dysplasia, and moderate dysplasia); the remaining 19% (23 of 120) consisted of malignant lesions (including severe dysplasia, carcinoma in situ, and invasive carcinoma). The accuracy of differential diagnosis for vocal cord leukoplakia using NBI endoscopy was up to 90.8% (109 of 120), significantly higher than that of white light imaging (70.0%, 84 of 120) (χ2 = 16.536, P = 0.000). The sensitivity, specificity, and positive and negative predictive values of the diagnosis for malignant vocal cord leukoplakia under the NBI endoscope were 82.6%, 92.8%, 73.1%, and 95.7%, respectively. There is relatively good consistency between the NBI endoscopic diagnosis and pathological diagnosis (kappa = 0.718, P = 0.000).
Conclusion
The new NBI endoscopic classification of vocal cord leukoplakia can improve the accuracy of distinguishing benign and malignant leukoplakia.
Level of Evidence
4 Laryngoscope, 129:429–434, 2019
The electrochemical N2 fixation, which is far from practical application in aqueous solution under ambient conditions, is extremely challenging and requires a rational design of electrocatalytic ...centers. We observed that bismuth (Bi) might be a promising candidate for this task because of its weak binding with H adatoms, which increases the selectivity and production rate. Furthermore, we successfully synthesized defect‐rich Bi nanoplates as an efficient noble‐metal‐free N2 reduction electrocatalyst via a low‐temperature plasma bombardment approach. When exclusively using 1H NMR measurements with N2 gas as a quantitative testing method, the defect‐rich Bi(110) nanoplates achieved a 15NH3 production rate of 5.453 μg mgBi−1 h−1 and a Faradaic efficiency of 11.68 % at −0.6 V vs. RHE in aqueous solution at ambient conditions.
Beneficial defects: Defect‐rich bismuth nanoplates achieve a 15NH3 production rate of 5.453 μg mgBi−1 h−1 and a Faradaic efficiency of 11.68 % at −0.6 V vs. RHE in aqueous solutions at ambient conditions because of their poor binding with H adatoms, which increases the selectivity and production rate. Also, 1H NMR measurements with N2 gas ware used as a quantitative test method in aqueous electrolytes.
The catalytic asymmetric synthesis of
P
-stereogenic phosphines is an efficient strategy to access structurally diverse chiral phosphines that could serve as organocatalysts and ligands to transition ...metals and motifs of antiviral drugs. Herein, we describe a Ni catalyzed highly regio and enantioselective hydrophosphinylation reaction of secondary phosphine oxides and enynes. This method afforded a plethora of alkenyl phosphine oxides which could serve as valuable precursors to bidentate ligands. A new type of mechanism was discovered by combined kinetic studies and density functional theory (DFT) calculations, which was opposed to the widely accepted Chalk-Harrod type mechanism. Notably, the alkene moiety which could serve as a directing group by coordinating with the Ni catalyst in the transition state, plays a vital role in determining the reactivity, regio and enantioselectivity.
A Ni-catalyzed hydrophosphinylation reaction of enynes was reported with excellent regio and enantioselectivity. A protonation mechanism was uncovered by combined kinetic studies and DFT calculations, which may lead to the discovery of other hydrofunctionalization reactions.
Although single-atomically dispersed metal-N
on carbon support (M-NC) has great potential in heterogeneous catalysis, the scalable synthesis of such single-atom catalysts (SACs) with high-loading ...metal-N
is greatly challenging since the loading and single-atomic dispersion have to be balanced at high temperature for forming metal-N
. Herein, we develop a general cascade anchoring strategy for the mass production of a series of M-NC SACs with a metal loading up to 12.1 wt%. Systematic investigation reveals that the chelation of metal ions, physical isolation of chelate complex upon high loading, and the binding with N-species at elevated temperature are essential to achieving high-loading M-NC SACs. As a demonstration, high-loading Fe-NC SAC shows superior electrocatalytic performance for O
reduction and Ni-NC SAC exhibits high electrocatalytic activity for CO
reduction. The strategy paves a universal way to produce stable M-NC SAC with high-density metal-N
sites for diverse high-performance applications.
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