Lipocalin‐2 (LCN2) has diverse functions in multiple pathophysiological conditions; however, its pathogenic role in vascular dementia (VaD) is unknown. Here, we investigated the role of LCN2 in VaD ...using rodent models of global cerebral ischemia and hypoperfusion with cognitive impairment and neuroinflammation. Mice subjected to transient bilateral common carotid artery occlusion (tBCCAo) for 50 min showed neuronal death and gliosis in the hippocampus at 7 days post‐tBCCAo. LCN2 expression was observed predominantly in the hippocampal astrocytes, whereas its receptor was mainly detected in neurons, microglia, and astrocytes. Furthermore, Lcn2‐deficient mice, compared with wild‐type animals, showed significantly weaker CA1 neuronal loss, cognitive decline, white matter damage, blood–brain barrier permeability, glial activation, and proinflammatory cytokine production in the hippocampus after tBCCAo. Lcn2 deficiency also attenuated hippocampal neuronal death and cognitive decline at 30 days after unilateral common carotid artery occlusion (UCCAo). Furthermore, intracerebroventricular (i.c.v) injection of recombinant LCN2 protein elicited CA1‐neuronal death and a cognitive deficit. Our studies using cultured glia and hippocampal neurons supported the decisive role of LCN2 in hippocampal neurotoxicity and microglial activation, and the role of the HIF‐1α–LCN2–VEGFA axis of astrocytes in vascular injury. Additionally, plasma levels of LCN2 were significantly higher in patients with VaD than in the healthy control subjects. These results indicate that hippocampal damage and cognitive impairment are mediated by LCN2 secreted from reactive astrocytes in VaD.
Main Points
Astrocyte‐derived LCN2 mediates hippocampal damage in rodent models of vascular dementia, with higher plasma levels of LCN2 protein in patients with vascular dementia, suggesting the possibility of effective glia‐based treatment for vascular dementia.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Lithium (Li) metal is regarded as the most attractive anode material for high‐energy Li batteries, but it faces unavoidable challenges—uncontrollable dendritic growth of Li and severe volume changes ...during Li plating and stripping. Herein, a porous carbon framework (PCF) derived from a metal–organic framework (MOF) is proposed as a dual‐phase Li storage material that enables efficient and reversible Li storage via lithiation and metallization processes. Li is electrochemically stored in the PCF upon charging to 0 V versus Li/Li+ (lithiation), making the PCF surface more lithiophilic, and then the formation of metallic Li phase can be induced spontaneously in the internal nanopores during further charging below 0 V versus Li/Li+ (metallization). Based on thermodynamic calculations and experimental studies, it is shown that atomically dispersed zinc plays an important role in facilitating Li plating and that the reversibility of Li storage is significantly improved by controlled nanostructural engineering of 3D porous nanoarchitectures to promote the uniform formation of Li. Moreover, the MOF‐derived PCF does not suffer from macroscopic volume changes during cycling. This work demonstrates that the nanostructural engineering of porous carbon structures combined with lithiophilic element coordination would be an effective approach for realizing high‐capacity, reversible Li‐metal anodes.
A porous carbon nanoarchitecture derived from metal–organic frameworks is strategically suggested as a dual‐phase lithium (Li) storage host for Li‐metal batteries. Controlled open pores are highly desired for providing abundant free spaces for metallization of Li and atomically dispersed zinc metal and nitrogen play an important role in enhancing affinity toward Li+ and electrical conductivity during Li plating–stripping without any structural degradation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background and Aims
Studies on differential effect of aspirin therapy on HCC risk across the spectrum of liver diseases are lacking. We investigated the association between aspirin use and risks of ...HCC, liver‐associated death, and major bleeding in chronic hepatitis B (CHB) patients with or without cirrhosis.
Approach and Results
We identified 329,635 eligible adults with CHB from 2007 through 2017, using the Korean National Health Insurance Service database, including patients who received aspirin for ≥90 consecutive days (n = 20,200) and patients who never received antiplatelet therapy (n = 309,435). Risks of HCC, liver‐associated mortality, and major bleeding were estimated in a propensity‐score–matched cohort (19,003 pairs), accounting for competing risks. With a median follow‐up of 6.7 years, 10‐year cumulative incidence of HCC was 9.5% in the aspirin‐treated group and 11.3% in the untreated group (adjusted subdistribution hazard ratio aSHR, 0.85; 95% CI, 0.78–0.92). However, among patients with cirrhosis (2479 pairs), an association of aspirin use with HCC risk was not evident (aSHR, 1.00; 95% CI, 0.85–1.18). Cirrhosis status had a significant effect on the association between aspirin use and HCC risk (pinteraction, n = 0.04). Aspirin use was also associated with lower liver‐associated mortality (aSHR, 0.80; 95% CI, 0.71–0.90). Moreover, aspirin use was not associated with major bleeding risk (aSHR, 1.09; 95% CI, 0.99–1.21).
Conclusions
Aspirin use was associated with reduced risks of HCC and liver‐associated mortality in adults with CHB. Cirrhosis status had a substantial effect on the association between aspirin use and HCC risk.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A high‐performance novel photodetector is demonstrated, which consists of graphene and CH3 NH3PbI3 perovskite layers. The resulting hybrid photodetector exhibits a dramatically enhanced photo ...responsivity (180 A/W) and effective quantum efficiency (5× 104%) over a broad bandwidth within the UV and visible ranges.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This paper discusses a new design approach that uses hybrid power combining rectenna array in radio frequency (RF) energy transfer systems to receive more energy in a wide incident angle range. A ...beam-forming matrix and a dc power management network (PMN) are introduced to the hybrid power combining. The normalized dc output power of the proposed hybrid power combining array is compared to the conventional power combining methods with regard to the incident wave angle, and the average received dc power is also calculated and compared. To experimentally verify the proposed hybrid combining array performance, four suspended patch antennas are attached to RF energy receiving architecture. A 4 × 4 Butler matrix and quadrature hybrids are used for the beam-forming matrix in a hybrid power combining rectenna array. A reconfigurable voltage doubler rectifier with a dc PMN is used to convert RF energy to dc energy and delivers proper voltage to the load. The measured results of each component are presented. Moreover, an experimental verification using fabricated components for RF energy transfer is presented and the measured received dc output power of conventional and proposed structures is presented and compared.
Current hyaluronic acid (HA) hydrogel systems often cause cytotoxicity to encapsulated cells and lack the adhesive property required for effective localization of transplanted cells in vivo. In ...addition, the injection of hydrogel into certain organs (e.g., liver, heart) induces tissue damage and hemorrhage. In this study, we describe a bioinspired, tissue‐adhesive hydrogel that overcomes the limitations of current HA hydrogels through its improved biocompatibility and potential for minimally invasive cell transplantation. HA functionalized with an adhesive catecholamine motif of mussel foot protein forms HA‐catechol (HA‐CA) hydrogel via oxidative crosslinking. HA‐CA hydrogel increases viability, reduces apoptosis, and enhances the function of two types of cells (human adipose‐derived stem cells and hepatocytes) compared with a typical HA hydrogel crosslinked by photopolymerization. Due to the strong tissue adhesiveness of the HA‐CA hydrogel, cells are easily and efficiently transplanted onto various tissues (e.g., liver and heart) without the need for injection. Stem cell therapy using the HA‐CA hydrogel increases angiogenesis in vivo, leading to improved treatment of ischemic diseases. HA‐CA hydrogel also improved hepatic functions of transplanted hepatocytes in vivo. Thus, this bioinspired, tissue‐adhesive HA hydrogel can enhance the efficacy of minimally invasive cell therapy.
Bioinspired, catechol‐modified hyaluronic acid (HA) hydrogel is highly biocompatible and exhibits improved tissue adhesiveness in comparison to HA hydrogel crosslinked via photopolymerization. Tissue adhesive catechol‐modified HA hydrogel can mediate highly effective, minimally invasive cell therapy in defected models such as liver resection and myocardial infarction.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The gas diffusion layer (GDL) plays a key role on reactant gas diffusion and water management in proton exchange membrane (PEM) fuel cells. This paper reviews recent developments of single- and ...dual-layer GDLs for PEM fuel cells and various materials and approaches used for development of novel GDL. A variety of carbon- and metal-based macroporous substrates are presented. Hydrophobic treatments using different fluorinated polymers are addressed. Engineering parameters which control the performance of microporous layer such as carbon treatment, wettability, thickness, and microstructure are also reviewed. In addition, future prospects for development of new GDL development are discussed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Several studies have demonstrated chemopreventive effects of aspirin against hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB).
To investigate the associations of aspirin use ...with risks of HCC, liver-related mortality, and major bleeding according to metabolic risk factor burden among non-cirrhotic patients with CHB METHODS: Using the Korean National Health Insurance Service database, we identified 282,611 non-cirrhotic adults with CHB. Data on obesity, diabetes, high blood pressure, and hypercholesterolemia were collected. Subjects were stratified into lower and higher metabolic risk groups (≤2 and ≥3 risk factors, respectively). Propensity score-matched cohorts of aspirin users and non-users were generated. Risks of HCC, liver-related death and major bleeding were analyzed.
During the median follow-up of 7.4 years, positive associations between metabolic risk factor burden and outcomes were verified (all p
< 0.001). In the lower metabolic risk group (13,104 pairs), the association between aspirin use and HCC risk was not significant after multivariable adjustment (adjusted subdistribution hazard ratio aSHR: 0.93; 95% CI: 0.84-1.03); however, aspirin use was associated with elevated major bleeding risk (aSHR: 1.22; 95% CI: 1.08-1.39). In the higher metabolic risk group (2984 pairs), aspirin use was associated with reduced risks of HCC (aSHR: 0.72; 95% CI: 0.57-0.91) and liver-related mortality (aSHR: 0.69; 95% CI: 0.50-0.96) without an increase in risk of major bleeding (aSHR: 1.02; 95% CI: 0.79-1.32).
Aspirin therapy was associated with reduced risks of HCC and liver-related death without excess risk of major bleeding, in non-cirrhotic patients with CHB who had a higher metabolic risk factor burden.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
MnFe2O4@PDA-coated MWCNT coaxial nanocables are successfully designed via a simple one-pot process by utilizing the adhesion property of polydopamine (PDA) with cations in aqueous solutions and ...employing a modified co-precipitation synthesis at a low temperature. The incorporation of the PDA coating layer on the MWCNT leads to the well-dispersed state of the MWCNTs in the aqueous solution due to the hydrophilic functional group of the PDA coating layer. In addition, the catechol-based functional group of the PDA coating layer effectively anchors the Mn and Fe ions from the aqueous solution before the co-precipitation process, eventually resulting in the preferential and homogeneous formation of MnFe2O4 nanoparticles on the MWCNT. The final MnFe2O4@PDA-coated MWCNT electrode exhibits excellent power characteristics such as a high rate capacity of around of 367 mA h g−1 at a 5C-rate condition (= 4585 mA g−1). Cycling tests reveal that the stable performance of the MnFe2O4@PDA-coated MWCNT electrode persists even after 350 cycles.
Atomically thin two-dimensional materials have emerged as promising candidates for flexible and transparent electronic applications. Here we show non-volatile memory devices, based on field-effect ...transistors with large hysteresis, consisting entirely of stacked two-dimensional materials. Graphene and molybdenum disulphide were employed as both channel and charge-trapping layers, whereas hexagonal boron nitride was used as a tunnel barrier. In these ultrathin heterostructured memory devices, the atomically thin molybdenum disulphide or graphene-trapping layer stores charge tunnelled through hexagonal boron nitride, serving as a floating gate to control the charge transport in the graphene or molybdenum disulphide channel. By varying the thicknesses of two-dimensional materials and modifying the stacking order, the hysteresis and conductance polarity of the field-effect transistor can be controlled. These devices show high mobility, high on/off current ratio, large memory window and stable retention, providing a promising route towards flexible and transparent memory devices utilizing atomically thin two-dimensional materials.
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