305 research outputs found

    GW25-e3473 In vivo quantification of VCAM-1 expression in atherosclerosis model using non-invasive targeted ultrasound imaging

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    Vertically-aligned Mn(OH)2 nanosheet films for flexible all-solid-state electrochemical supercapacitors

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    The arrangement of the electrode materials is a significant contributor for constructing high performance supercapacitor. Here, vertically-aligned Mn(OH)2 nanosheet thin films were synthesized by cathodic electrodeposition technique on flexible Au coated polyethylene terephthalate substrates. Morphologies, microstructures, chemical compositions and valence state of the nanosheet films were characterized systematically. It shows that the nanosheets arranged vertically to the substrate, forming a porous nanowall structures and creating large open framework, which greatly facilitate the adsorption or diffusion of electrolyte ions for faradaic redox reaction. Electrochemical tests of the films show the specific capacitance as high as 240.2 F gāˆ’1 at 1.0 A gāˆ’1. The films were employed to assemble symmetric all-solid-state supercapacitors with LiCl/PVA gel severed as solid electrolyte. The solid devices exhibit high volumetric capacitance of 39.3 mF cmāˆ’3 at the current density 0.3 mA cmāˆ’3 with robust cycling stability. The superior performance is attributed to the vertically-aligned configuration

    ESC-Derived Basal Forebrain Cholinergic Neurons Ameliorate the Cognitive Symptoms Associated with Alzheimerā€™s Disease in Mouse Models

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    SummaryDegeneration of basal forebrain cholinergic neurons (BFCNs) is associated with cognitive impairments of Alzheimerā€™s disease (AD), implying that BFCNs hold potentials in exploring stem cell-based replacement therapy for AD. However, studies on derivation of BFCNs from embryonic stem cells (ESCs) are limited, and the application of ESC-derived BFCNs remains to be determined. Here, we report on differentiation approaches for directing both mouse and human ESCs into mature BFCNs. These ESC-derived BFCNs exhibit features similar to those of their inĀ vivo counterparts and acquire appropriate functional properties. After transplantation into the basal forebrain of AD model mice, ESC-derived BFCN progenitors predominantly differentiate into mature cholinergic neurons that functionally integrate into the endogenous basal forebrain cholinergic projection system. The AD mice grafted with mouse or human BFCNs exhibit improvements in learning and memory performances. Our findings suggest a promising perspective of ESC-derived BFCNs in the development of stem cell-based therapies for treatment of AD

    Imaging and Pathological Features of Percutaneous Cryosurgery on Normal Lung Evaluated in a Porcine Model

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    Background and objective Lung cancer is one of the most commonly occurring malignancies and frequent causes of death in the world. Cryoablation is a safe and alternative treatment for unresectable lung cancer. Due to the lung being gas-containing organ and different from solid organs such as liver and pancreas, it is difficult to achieve the freezing range of beyond the tumor edge 1 cm safety border. The aim of this study is to examine the effect of different numbers of freeze cycles on the effectiveness of cryoablation on normal lung tissue and to create an operation guideline that gives the best effect. Methods Six healthy Tibetan miniature pigs were given a CT scan and histological investigation after percutaneous cryosurgery. Cryoablation was performed as 2 cycles of 10 min of active freezing in the left lung; each freeze followed by a 5 min thaw. In the right lung, we performed the same 2 cycles of 5 min of freezing followed by 5 min of thawing. However, for the right lung, we included a third cycle of consisting of 10 min of freezing followed by 5 min of thawing. Three cryoprobes were inserted into the left lung and three cryoprobes in the right lung per animal, one in the upper and two in the lower lobe, so as to be well away from each other. Comparison under the same experimental condition was necessary. During the experiment, observations were made regarding the imaging change of ice-ball. The lungs were removed postoperatively at 3 intervals: 4 h, 3 d of postoperation and 7 d of postoperation, respectively, to view microscopic and pathological change. Results The ice-ball grew gradually in relation to the increase in time, and the increase in number of cycles. The size of the cryolesion (hypothesis necrotic area) in specimens, over time, became larger in size than the size of the ice-ball during operation, regardless of whether 2 or 3 freeze-thaw cycles were performed. The area of necrosis was gradually increased over the course of time. The hypothesis necrotic area was equal to necrosis area 3 d after cryosurgery. Conclusion Percutaneous cryoablation of the lung can achieve complete ablation of target tissue. The freezing technique may be different depending on the individual circumstances of each tumor. In technology, 3 freeze-thaw cycles are recommended, and the range of cryoablationā€™s effective diameter may be not necessarily beyond the tumor edge at least 1 cm safe border during cryosurgery

    Influence of uniaxial tensile stress on the mechanical and piezoelectric properties of short-period ferroelectric superlattice

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    Tetragonal ferroelectric/ferroelectric BaTiO3/PbTiO3 superlattice under uniaxial tensile stress along the c axis is investigated from first principles. We show that the calculated ideal tensile strength is 6.85 GPa and that the superlattice under the loading of uniaxial tensile stress becomes soft along the nonpolar axes. We also find that the appropriately applied uniaxial tensile stress can significantly enhance the piezoelectricity for the superlattice, with piezoelectric coefficient d33 increasing from the ground state value by a factor of about 8, reaching 678.42 pC/N. The underlying mechanism for the enhancement of piezoelectricity is discussed

    What makes efficient circularly polarised luminescence in the condensed phase: aggregation-induced circular dichroism and light emission

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    In this contribution, we conceptually present a new avenue to construction of molecular functional materials with high performance of circularly polarised luminescence (CPL) in the condensed phase. A molecule (1) containing luminogenic silole and chiral sugar moieties was synthesized and thoroughly characterized. In a solution of 1, no circular dichroism (CD) and fluorescence emission are observed, but upon molecular aggregation, both the CD and fluorescence are simultaneously turned on, showing aggregation-induced CD (AICD) and emission (AIE) effects. The AICD effect is supported by the fact that the molecules readily assemble into right-handed helical nanoribbons and superhelical ropes when aggregated. The AIE effect boosts the fluorescence quantum efficiency (Ī¦F) by 136 fold (Ī¦F, āˆ¼0.6% in the solution versus āˆ¼81.3% in the solid state), which surmounts the serious limitations of aggregation-caused quenching effect encountered by conventional luminescent materials. Time-resolved fluorescence study and theoretical calculation from first principles conclude that restriction of the low-frequency intramolecular motions is responsible for the AIE effect. The helical assemblies of 1 prefer to emit right-handed circularly polarised light and display large CPL dissymmetry factors (gem), whose absolute values are in the range of 0.08ā€“0.32 and are two orders of magnitude higher than those of commonly reported organic materials. We demonstrate for the first time the use of a Teflon-based microfluidic technique for fabrication of the fluorescent pattern. This shows the highest gem of āˆ’0.32 possibly due to the enhanced assembling order in the confined microchannel environment. The CPL performance was preserved after more than half year storage under ambient conditions, revealing the excellent spectral stability. Computational simulation was performed to interpret how the molecules in the aggregates interact with each other at the molecular level. Our designed molecule represents the desired molecular functional material for generating efficient CPL in the solid state, and the current study shows the best results among the reported organic conjugated molecular systems in terms of emission efficiency, dissymmetry factor, and spectral stability

    A differentiated digital intervention to improve antiretroviral therapy adherence among men who have sex with men living with HIV in China: a randomized controlled trial.

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    BACKGROUND: Antiretroviral therapy (ART) adherence is still suboptimal among some key populations, highlighting the need for innovative tailored strategies. This randomized controlled trial (RCT) aimed to evaluate the effect of a differentiated digital intervention on ART adherence among men who have sex with men (MSM) living with HIV in China. METHODS: The two-armed parallel RCT was conducted at one HIV clinic in Jinan of China from October 19, 2020, to June 31, 2021. Men were referred by health providers to join the study and then choose one of three digital strategies-text message, only instant message, or instant message plus social media. They were assigned in a 1:1 ratio to the intervention arm or control arm using block randomization, and inside each arm, there were three groups depending on the type of delivering the message. The groups were divided according to participants' preferred digital strategies. The intervention arm received ART medication messages, medication reminders, peer education, and involved in online discussion. The control arm received messages on health behavior and nutrition. The primary outcome was self-reported optimal ART adherence, defined as not missing any doses and not having any delayed doses within a one-month period. Secondary outcomes included CD4 T cell counts, viral suppression, HIV treatment adherence self-efficacy, and quality of life. Intention-to-treat analysis with generalized linear mixed models was used to evaluate the intervention's effect. RESULTS: A total of 576 participants were enrolled, including 288 participants assigned in the intervention arm and 288 assigned in the control arm. Most were ā‰¤ 40 years old (79.9%) and initiated ART ā‰¤ 3 years (60.4%). After intervention, the proportion of participants achieving optimal ART adherence in the intervention arm was higher than in the control arm (82.9% vs 71.1%). The differentiated digital intervention significantly improved ART adherence (RRā€‰=ā€‰1.74, 95%CI 1.21-2.50). Subgroup analysis showed one-to-one instant message-based intervention significantly improved ART adherence (RRā€‰=ā€‰2.40, 95% CI 1.39-4.17). CONCLUSIONS: The differentiated digital intervention improved ART adherence among MSM living with HIV in China, which could be integrated into people living with HIV (PLWH) management and further promoted in areas where PLWH can access text messaging and instant messaging services. TRIAL REGISTRATION: ChiCTR2000041282. Retrospectively registered on 23 December 2020

    Protective effects and potential mechanisms of Pien Tze Huang on cerebral chronic ischemia and hypertensive stroke

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    <p>Abstract</p> <p>Background</p> <p>Stroke caused by brain ischemia is the third leading cause of adult disability. Active prevention and early treatment of stroke targeting the causes and risk factors may decrease its incidence, mortality and subsequent disability. Pien Tze Huang (PZH), a Chinese medicine formula, was found to have anti-edema, anti-inflammatory and anti-thrombotic effects that can prevent brain damage. This study aims to investigate the potential mechanisms of the preventive effects of Pien Tze Huang on brain damage caused by chronic ischemia and hypertensive stroke in rats.</p> <p>Methods</p> <p>The effects of Pien Tze Huang on brain protein expression in spontaneously hypertensive rat (SHR) and stroke prone SHR (SHRsp) were studied with 2-D gel electrophoresis and mass spectrometric analysis with a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)/TOF tandem mass spectrometer and on brain cell death with enzyme link immunosorbent assay (ELISA) and immunostaining.</p> <p>Results</p> <p>Pien Tze Huang decreased cell death in hippocampus and cerebellum caused by chronic ischemia and hypertensive stroke. Immunostaining of caspase-3 results indicated that Pien Tze Huang prevents brain cells from apoptosis caused by ischemia. Brain protein expression results suggested that Pien Tze Huang downregulated QCR<sub>2 </sub>in the electron transfer chain of mitochondria preventing reactive oxygen species (ROS) damage and possibly subsequent cell death (caspase 3 assay) as caused by chronic ischemia or hypertensive stroke to hippocampus and cerebellum.</p> <p>Conclusion</p> <p>Pien Tze Huang showed preventive effects on limiting the damage or injury caused by chronic ischemia and hypertensive stroke in rats. The effect of Pien Tze Huang was possibly related to prevention of cell death from apoptosis or ROS/oxidative damage in mitochondria.</p
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