86 research outputs found

    Lithium Salt Effects on Silicon Electrode Performance and Solid Electrolyte Interphase (SEI) Structure, Role of Solution Structure on SEI Formation

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    Silicon electrodes were cycled with electrolytes containing different salts to investigate the effect of salt on the electrochemical performance and SEI structure. Comparable capacity retention were observed for the 1.2 M LiPF6, LiTFSI and LiClO4 electrolytes in ethylene carbonate (EC):dimethyl carbonate (DEC), 1:1, but severe fading was observed for the 1.2 M LiBF4 electrolyte. The differential capacity plots and EIS analysis reveals that failure of the 1.2 M LiBF4 electrolyte is attributed to large surface resistance and increasing polarization upon cycling. However, when LiBF4 was added as an electrolyte additive (10% LiBF4 and 90% LiPF6), the capacity retention and Coulombic efficiency were improved. The SEI was analyzed by FTIR and XPS for each electrolyte. Both spectroscopic methods suggest that the main components of the SEI are lithium ethylene dicarbonate (LEDC) and Li2CO3 in the 1.2 M LiPF6, LiTFSI and LiClO4 electrolytes, while an inorganic-rich SEI, composed of LiF and borates, was generated for both the 1.2 M LiBF4 electrolyte and the 10% LiBF4 electrolyte. The chemical composition of the SEIs and corresponding electrochemical performance of the Si electrodes were strongly correlated with electrolyte solution structure

    Capacity Fading Mechanisms of Silicon Nanoparticle Negative Electrodes for Lithium Ion Batteries

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    A thorough analysis of the evolution of the voltage profiles of silicon nanoparticle electrodes upon cycling has been conducted. The largest changes to the voltage profiles occur at the earlier stages (\u3e 0.16 V vs Li/Li+) of lithiation of the silicon nanoparticles. The changes in the voltage profiles suggest that the predominant failure mechanism of the silicon electrode is related to incomplete delithiation of the silicon electrode during cycling. The incomplete delithiation is attributed to resistance increases during delithiation, which are predominantly contact and solid electrolyte interface (SEI) resistance. The capacity retention can be significantly improved by lowering delithiation cutoff voltage or by introducing electrolyte additives, which generate a superior SEI. The improved capacity retention is attributed to the reduction of the contact and SEI resistance

    Censored Sampling of Diffusion Models Using 3 Minutes of Human Feedback

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    Diffusion models have recently shown remarkable success in high-quality image generation. Sometimes, however, a pre-trained diffusion model exhibits partial misalignment in the sense that the model can generate good images, but it sometimes outputs undesirable images. If so, we simply need to prevent the generation of the bad images, and we call this task censoring. In this work, we present censored generation with a pre-trained diffusion model using a reward model trained on minimal human feedback. We show that censoring can be accomplished with extreme human feedback efficiency and that labels generated with a mere few minutes of human feedback are sufficient. Code available at: https://github.com/tetrzim/diffusion-human-feedback.Comment: Published in NeurIPS 202

    Understanding NK cell biology for harnessing NK cell therapies: targeting cancer and beyond

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    Gene-engineered immune cell therapies have partially transformed cancer treatment, as exemplified by the use of chimeric antigen receptor (CAR)-T cells in certain hematologic malignancies. However, there are several limitations that need to be addressed to target more cancer types. Natural killer (NK) cells are a type of innate immune cells that represent a unique biology in cancer immune surveillance. In particular, NK cells obtained from heathy donors can serve as a source for genetically engineered immune cell therapies. Therefore, NK-based therapies, including NK cells, CAR-NK cells, and antibodies that induce antibody-dependent cellular cytotoxicity of NK cells, have emerged. With recent advances in genetic engineering and cell biology techniques, NK cell-based therapies have become promising approaches for a wide range of cancers, viral infections, and senescence. This review provides a brief overview of NK cell characteristics and summarizes diseases that could benefit from NK-based therapies. In addition, we discuss recent preclinical and clinical investigations on the use of adoptive NK cell transfer and agents that can modulate NK cell activity

    Differential effects of luteolin and its glycosides on invasion and apoptosis in MDA-MB-231 triple-negative breast cancer cells

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    Luteolin is known to have anticancer activity in various ca ncers. Recent studies have shown that luteolin glyco- sides, such as luteolin-8- C - Ī² -fucopyranoside, 7-methoxy-luteolin-8-C- Ī² -(6- deoxyxylopyranos-3-uloside) and lu- teolin-8-C- Ī² - D -glucopyranoside, flavonoid s that are present in Arthraxon hispidus , exert antimigratory and anti- invasive effects, but no cytotoxic effect in estrogen receptor-positive MCF7 breast cancer cells. In the present study, we further investigated and compared differential effects of luteolin and its glycosides in MDA-MB-231 triple-negative breast cancer cells. Lute olin suppressed the expression of matrix metalloproteinase-9 and inhibited migration and invasion in MDA-MB-231 cells treated with the tumor promotor 12-O-tetradecanoylphorbol-13- acetate at non-cytotoxic concentrations (0, 5, and 10 Ī¼ M). Furthermore, at cytotoxic concentrations (20 and 40 Ī¼ M), luteolin induced apoptosis via extrinsic and intrinsic pathways in MDA-MB-231 cells. However, luteolin glycosides did not exert any cytotoxic, antimigratory, or anti-invasive effect in MDA-MB-231 cells . In brief, l u- teolin had both antimetastatic and cytotoxic effects on MDA-MB-231 cells, whereas luteolin glycosides had no effect on this cell line. Taking together the present results and our previous findings on the differential effects of luteolin and its glycosides on MDA-MB-231 and MCF-7 br east cancer cells, luteolin and its glycosides can be suggested as a potential candida te for breast cancer therapy

    Preparation of nanoscale inorganic CsPbIxBr3-x perovskite photosensitizers on the surface of mesoporous TiO2 film for solid-state sensitized solar cells

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    Metal chalcogenide quantum dot (QD)-like all-inorganic nanoscale perovskite photosensitizers of CsPbIxBr3-x were prepared on the surface of mesoscopic TiO2 film by a direct two-step spin-coating of lead and cesium halide precursors for application into solid-state dye-sensitized solar cells (DSSCs), as confirmed by impedance frequency response analysis. A few nanometer-sized hemisphere-shaped dots of CsPbIxBr3-x perovskites were deposited and distributed separately onto TiO2, which were checked by scanning and transmission electron microscopic (SEM and TEM) techniques. The as-deposited CsPbIxBr3-x perovskites were stable only in the case of including about 20% or more bromide in the composition of halides. When the bromide content increased in the ratio of halides of CsPbIxBr3-x, gradual decrease in lattice spacing and blue-shift of emission peaks were observed in X-ray diffraction (XRD) and photoluminescence (PL) measurements, respectively. These well-defined nano-particulate CsPbIxBr3-x perovskites were incorporated into solid-state DSSCs and tested as a new type of photosensitizers. The initial power conversion efficiency (PCE) of ca. 1.0ā€“3.5% based on relatively thin mesoporous TiO2 film (~1 Ī¼m) looks promising with many parameters remaining for possibly more optimization. The best result, 3.79%, was obtained from CsPbI2.2Br0.80 25 days after initial measurement. These CsPbIxBr3-x-sensitized cells displayed a stable record of PCE over ~2 month and no hysteresis behavior in current-voltage traces

    A novel sphingosylphosphorylcholine and sphingosine-1-phosphate receptor 1 antagonist, KRO-105714, for alleviating atopic dermatitis

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    Background Atopic dermatitis (eczema) is a type of inflammation of the skin, which presents with itchy, red, swollen, and cracked skin. The high global incidence of atopic dermatitis makes it one of the major skin diseases threatening public health. Sphingosylphosphorylcholine (SPC) and sphingosine-1-phosphate (S1P) act as pro-inflammatory mediators, as an angiogenesis factor and a mitogen in skin fibroblasts, respectively, both of which are important biological responses to atopic dermatitis. The SPC level is known to be elevated in atopic dermatitis, resulting from abnormal expression of sphingomyelin (SM) deacylase, accompanied by a deficiency in ceramide. Also, S1P and its receptor, sphingosine-1-phosphate receptor 1 (S1P1) are important targets in treating atopic dermatitis. Results In this study, we found a novel antagonist of SPC and S1P1, KRO-105714, by screening 10,000 compounds. To screen the compounds, we used an SPC-induced cell proliferation assay based on a high-throughput screening (HTS) system and a human S1P1 protein-based [35S]-GTPĪ³S binding assay. In addition, we confirmed the inhibitory effects of KRO-105714 on atopic dermatitis through related cell-based assays, including a tube formation assay, a cell migration assay, and an ELISA assay on inflammatory cytokines. Finally, we confirmed that KRO-105714 alleviates atopic dermatitis symptoms in a series of mouse models. Conclusions Taken together, our data suggest that SPC and S1P1 antagonist KRO-105714 has the potential to alleviate atopic dermatitis.This work was supported by a grant from the Korea Research Council for Industrial Science and Technology (KK-1933-20) to HC, under the industrial infrastructure program for fundamental technologies and Korea Institute for Advancement of Technology through the Inter-ER Cooperation Projects (R0002017) which are funded by the Ministry of Trade, Industry & Energy, Korea to YDG

    The ReInforcement of adherence via self-monitoring app orchestrating biosignals and medication of RivaroXaban in patients with atrial fibrillation and co-morbidities: a study protocol for a randomized controlled trial (RIVOX-AF)

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    BackgroundBecause of the short half-life of non-vitamin K antagonist oral anticoagulants (NOACs), consistent drug adherence is crucial to maintain the effect of anticoagulants for stroke prevention in atrial fibrillation (AF). Considering the low adherence to NOACs in practice, we developed a mobile health platform that provides an alert for drug intake, visual confirmation of drug administration, and a list of medication intake history. This study aims to evaluate whether this smartphone app-based intervention will increase drug adherence compared with usual care in patients with AF requiring NOACs in a large population.MethodsThis prospective, randomized, open-label, multicenter trial (RIVOX-AF study) will include a total of 1,042 patients (521 patients in the intervention group and 521 patients in the control group) from 13 tertiary hospitals in South Korea. Patients with AF aged ā‰„19 years with one or more comorbidities, including heart failure, myocardial infarction, stable angina, hypertension, or diabetes mellitus, will be included in this study. Participants will be randomly assigned to either the intervention group (MEDI-app) or the conventional treatment group in a 1:1 ratio using a web-based randomization service. The intervention group will use a smartphone app that includes an alarm for drug intake, visual confirmation of drug administration through a camera check, and presentation of a list of medication intake history. The primary endpoint is adherence to rivaroxaban by pill count measurements at 12 and 24 weeks. The key secondary endpoints are clinical composite endpoints, including systemic embolic events, stroke, major bleeding requiring transfusion or hospitalization, or death during the 24 weeks of follow-up.DiscussionThis randomized controlled trial will investigate the feasibility and efficacy of smartphone apps and mobile health platforms in improving adherence to NOACs.Trial registrationThe study design has been registered in ClinicalTrial.gov (NCT05557123)
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