Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 100
Filtrar
2.
Mater Horiz ; 11(4): 1008-1013, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38054251

RESUMO

Understanding the degradation of lithium-ion batteries is of utmost significance for preventing unexpected capacity drops and addressing safety concerns. The manner in which batteries degrade during operation has a notable influence on their subsequent cycle performance. In particular, the rapid capacity drop related to the spatial heterogeneity of the anode degradation highlights the necessity of a health indicator for an accurate battery diagnosis. A novel health indicator established in this study, the Dominant degradation factors among Negative and Positive electrodes (DNP) scores, enables clear identification of degraded states despite comparable capacity levels. Specifically, batteries with heterogeneous anode degradation exhibited negative scores and the aggravation of the cycle performance. It is anticipated that this health indicator can provide a distinct evaluation of batteries based on their degraded states, supporting onboard battery management and the efficient allocation of resources for the battery reuse industry.

3.
Sci Rep ; 13(1): 22370, 2023 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-38102169

RESUMO

During the COVID-19 pandemic, the world population faced various mental health challenges, highlighting a need for new community-based psychosocial interventions. This study aimed to investigate the effectiveness and feasibility of Nature-Based Therapy (NBT) for the community experiencing psychological distress during the pandemic. A multi-site trial comparing NBT and control groups was conducted in Korea with 291 participants exhibiting mild to severe depression or anxiety. A total of 192 participated in 30 sessions of therapeutic gardening, while 99 remained in the control group. Psychological distress and well-being were assessed using seven measures of depression, anxiety, daily activity, life satisfaction, mindfulness, stress, and loneliness. The effect sizes (Cohen's d) of NBT compared to the control group were medium to large: depression (0.583), anxiety (0.728), daily activity (1.002), life satisfaction (0.786), mindfulness (0.645), stress (0.903), and loneliness (0.695). Multilevel analysis revealed significant Time × Group interaction effects for all measures. Pearson correlation (r = - 0.28 to 0.71) showed that changes in all variables correlated significantly with each other, with small to large effect sizes. Therapeutic alliance at post-test positively moderated the intervention effects on the outcomes. We concluded that NBT is a promising psychosocial intervention for treating psychological distress for community dwellers.


Assuntos
COVID-19 , Angústia Psicológica , Humanos , Ansiedade/terapia , COVID-19/psicologia , Atenção Plena , Pandemias , Estresse Psicológico/terapia , Estresse Psicológico/psicologia
4.
ACS Nano ; 17(22): 22778-22787, 2023 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-37947399

RESUMO

DNA is an anisotropic, water-attracting, and biocompatible material, an ideal building block for hydrogel. The alignment of the anisotropic DNA chains is essential to maximize hydrogel properties, which has been little explored. Here, we present a method to fabricate the anisotropic DNA hydrogel that allows precise control for the polymerization process of photoreactive cationic monomers. Scanning ultraviolet light enables the uniaxial alignment of DNA chains through the polymerization-induced diffusive mass flow using a concentration gradient. While studying anisotropic mechanical properties and orientation recovery according to the DNA chain alignment direction, we demonstrate the potential of directionally controlled DNA hydrogels as smart materials.


Assuntos
DNA , Hidrogéis , Hidrogéis/farmacologia , Materiais Biocompatíveis , Anisotropia
5.
Sci Adv ; 9(36): eadf3041, 2023 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-37672592

RESUMO

In eukaryotes, the posttranslational modifier ubiquitin is used to regulate the amounts, interactions, or activities of proteins in diverse pathways and signaling networks. Its effects are mediated by monoubiquitin or polyubiquitin chains of varying geometries. We describe the design, validation, and application of a series of avidity-based probes against the ubiquitylated forms of the DNA replication clamp, proliferating cell nuclear antigen (PCNA), in budding yeast. Directed against total ubiquitylated PCNA or specifically K63-polyubiquitylated PCNA, the probes are tunable in their activities and can be used either as biosensors or as inhibitors of the PCNA-dependent DNA damage bypass pathway. Used in live cells, the probes revealed the timing of PCNA ubiquitylation during damage bypass and a particular susceptibility of the ribosomal DNA locus to the activation of the pathway. Our approach is applicable to a wide range of ubiquitin-conjugated proteins, thus representing a generalizable strategy for the design of biosensors for specific (poly)ubiquitylated forms of individual substrates.


Assuntos
Dano ao DNA , Replicação do DNA , Antígeno Nuclear de Célula em Proliferação , DNA Ribossômico , Ubiquitina
6.
J Chem Educ ; 100(8): 3138-3143, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37577455

RESUMO

Sanger sequencing, also known as dideoxy sequencing, is a widely used method for DNA sequencing, particularly for cloned plasmids and clinical samples. This technique requires a combination of essential biochemistry skills, such as a chain-termination reaction, gel electrophoresis, and fluorescence detection. Unfortunately, there is a lack of activities that replicate the Sanger sequencing process for students to learn and practice these skills. To address this issue, a manipulative-based Sanger sequencing activity was developed that incorporates colorful pop beads to demonstrate a chain-termination reaction, separation of products, and fluorescence detection. The beads represent deoxynucleotides and dideoxynucleotides, allowing for a visual representation of DNA fragment generation. This kinesthetic learning activity offers a high visual impact for students, aiding in their understanding of the Sanger sequencing process, and can also be used to illustrate polymerase chain reaction (PCR)-based techniques.

8.
Adv Mater ; 35(36): e2303077, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37148534

RESUMO

The planar spin glass pattern is widely known for its inherent randomness, resulting from the geometrical frustration. As such, developing physical unclonable functions (PUFs)-which operate with device randomness-with planar spin glass patterns is a promising candidate for an advanced security systems in the upcoming digitalized society. Despite their inherent randomness, traditional magnetic spin glass patterns pose considerable obstacles in detection, making it challenging to achieve authentication in security systems. This necessitates the development of facilely observable mimetic patterns with similar randomness to overcome these challenges. Here, a straightforward approach is introduced using a topologically protected maze pattern in the chiral liquid crystals (LCs). This maze exhibits a comparable level of randomness to magnetic spin glass and can be reliably identified through the combination of optical microscopy with machine learning-based object detection techniques. The "information" embedded in the maze can be reconstructed through thermal phase transitions of the LCs in tens of seconds. Furthermore, incorporating various elements can enhance the optical PUF, resulting in a multi-factor security medium. It is expected that this security medium, based on microscopically controlled and macroscopically uncontrolled topologically protected structures, may be utilized as a next-generation security system.

9.
Yonsei Med J ; 64(5): 309-312, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37114633

RESUMO

PURPOSE: This study aimed to investigate the quality of medical care in North Korea using data from North Korean medical research. MATERIALS AND METHODS: This study included publications containing the keyword "medical" among North Korea's consecutive publications and selected 415 papers related to heart disease, brain disease, and emergency medical care published at The North Korean Data Center of the Ministry of Unification (https://unibook.unikorea.go.kr). Among 40 research articles, we reviewed ten with representative epidemiological data for cardiovascular treatment, and the latest medical materials were selected and analyzed in detail. RESULTS: Few studies reported the experience of large-scale medical facilities or verified professional performance. Proof of the efficacy of the latest drugs was rare, although the treatment results of interventional therapy and conventional heart surgery were reported. Efforts to improve emergency medical care and innovation of treatment materials using new technologies were being actively studied. However, careful interpretation is required due to the lack of objectivity in research data and some deviation in the composition of patients included in the data. CONCLUSION: Research of cardiovascular disease in North Korea is conducted at a very limited scope, although treatment results appear to be recorded. The management of cardiovascular disease and the establishment of an emergency medical system warrant global attention and cooperation for further improvement.


Assuntos
Pesquisa Biomédica , Doenças Cardiovasculares , Humanos , República Democrática Popular da Coreia/epidemiologia , Doenças Cardiovasculares/terapia
10.
Nano Lett ; 23(6): 2158-2165, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36854053

RESUMO

Embodying bosonic and interactive characteristics in two-dimensional space, excitons in transition metal dichalcogenides (TMDCs) have garnered considerable attention. The utilization of the strong-correlation effects, long-range transport, and valley-dependent properties requires customizing exciton decay dynamics. Vacuum-field manipulation allows radiative decay engineering without disturbing intrinsic material properties. However, conventional flat mirrors cannot customize the radiative decay landscape in TMDC's plane or support vacuum-field interference with desired spectrum and polarization properties. Here, we present a meta-mirror platform resolving the issues with more optical degrees of freedom. For neutral excitons of the monolayer MoSe2, the optical layout formed by meta-mirrors manipulated the radiative decay rate in space by 2 orders of magnitude and revealed the statistical correlation between emission intensity and spectral line width. Moreover, the anisotropic meta-mirror demonstrated polarization-dependent radiative decay control. Our platform would be promising to tailor two-dimensional distributions of lifetime, density, diffusion, and polarization of TMDC excitons in advanced opto-excitonic applications.

11.
Mater Horiz ; 10(4): 1274-1281, 2023 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-36806877

RESUMO

Accurately estimating the state-of-health (SOH) of lithium-ion batteries is emerging as a hot topic because of the rapid increase in electric appliance usage. However, versatile applicability to various battery compositions and diverse cycling conditions, and prediction only with partial data still remain challenges. In this paper, a Deep-learning-based Graphical approach to Estimation of Lithium-ion batteries SOH (D-GELS) was developed to predict the SOH covering three cathode materials, LiFePO4, LiNiCoAlO2, and LiNiCOMnO2. D-GELS shows an accurate performance for SOH prediction, less than 0.012 of RMSE, was predicted regardless of cathode materials, and its applicability was confirmed. Furthermore, D-GELS was capable of predicting the SOH using partially-cycled data, since less than 0.046 of RMSE was observed even with 50% of the image missing. When using partially-cycled profiles, significant economic benefits can be seen in used battery management, as the number of assessed batteries increases greatly, leading to cost savings.

12.
J Clin Med ; 12(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36675500

RESUMO

Few studies have reported comparisons of out-of-hospital clinical outcomes after transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis (AS) in the era of current-generation valves that reflect the real-world situation. Data on patients with severe AS aged 65 years or older who underwent TAVR or SAVR between 2015 and 2018 were obtained from the National Health Insurance Service in Korea and clinical event rate was analyzed. The primary endpoint was all-cause death at 1 year. The cohort included a total of 4623 patients over 65 years of age, of whom 1269 (27.4%) were treated with TAVR. After 1:1 propensity score matching, 2120 patients were included in the study. TAVR was associated with reduced 1-year mortality (hazard ratio (HR): 0.55; 95% confidence interval (CI): 0.42−0.70; p < 0.001). There was no difference between the groups in the incidence of ischemic stroke (HR: 0.72, 95% CI: 0.43−1.20; p = 0.21) and intracranial hemorrhage (HR: 1.10; p = 0.74). Permanent pacemaker insertion was observed more frequently in the TAVR cohort (9.4% vs. 2.5%, HR: 3.95, 95% CI: 2.57−6.09; p < 0.001), whereas repeat procedures were rare in both treatments (0.5% vs. 0.3%, p = 0.499). In the nation-wide real-world data analysis, TAVR with current-generation devices showed significantly lower 1-year mortality compared to SAVR in severe AS patients.

14.
Methods Mol Biol ; 2591: 255-267, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36350553

RESUMO

Deubiquitinating enzymes cleave ubiquitin (Ub) from its attachment to another Ub, other proteins, peptides, or non-peptide adducts. In all cases, substrate hydrolysis by DUBs releases free Ub or polyubiquitin (polyUb) chains. Whereas most quantitative DUB assays depend on fluorescently labeled artificial substrates, employing a sensor able to detect Ub release in real time makes it possible to monitor DUB activity using virtually any Ub conjugate as a substrate. The protocols here describe the preparation of Atto532-tUI, a high-affinity sensor for free Ub, and its use in real-time deubiquitination assays.


Assuntos
Poliubiquitina , Ubiquitina , Ubiquitina/metabolismo , Ubiquitinação , Poliubiquitina/metabolismo , Hidrólise
15.
Nature ; 611(7934): 48-54, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36224392

RESUMO

Optical vortices are beams of light that carry orbital angular momentum1, which represents an extra degree of freedom that can be generated and manipulated for photonic applications2-8. Unlike vortices in other physical entities, the generation of optical vortices requires structural singularities9-12, but this affects their quasiparticle nature and hampers the possibility of altering their dynamics or making them interacting13-17. Here we report a platform that allows the spontaneous generation and active manipulation of an optical vortex-antivortex pair using an external field. An aluminium/silicon dioxide/nickel/silicon dioxide multilayer structure realizes a gradient-thickness optical cavity, where the magneto-optic effects of the nickel layer affect the transition between a trivial and a non-trivial topological phase. Rather than a structural singularity, the vortex-antivortex pairs present in the light reflected by our device are generated through mathematical singularities in the generalized parameter space of the top and bottom silicon dioxide layers, which can be mapped onto real space and exhibit polarization-dependent and topology-dependent dynamics driven by external magnetic fields. We expect that the field-induced engineering of optical vortices that we report will facilitate the study of topological photonic interactions and inspire further efforts to bestow quasiparticle-like properties to various topological photonic textures such as toroidal vortices, polarization and vortex knots, and optical skyrmions.

16.
Nat Commun ; 13(1): 5615, 2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36153310

RESUMO

Controlling the orientation of two-dimensional materials is essential to optimize or tune their functional properties. In particular, aligning MXene, a two-dimensional carbide and/or nitride material, has recently received much attention due to its high conductivity and high-density surface functional group properties that can easily vary based on its arranged directions. However, erecting 2D materials vertically can be challenging, given their thinness of few nanometres. Here, vertical alignment of Ti3C2Tx MXene sheets is achieved by applying an in-plane electric field, which is directly observed using polarised optical microscopy and scanning electron microscopy. The electric field-induced vertical alignment parallel to the applied alternating-current field is demonstrated to be reversible in the absence of a field, back to a random orientation distribution. Interdigitated electrodes with uniaxially aligned MXene nanosheets are demonstrated. These can be further modulated to achieve various patterns using diversified electrode substrates. Anisotropic electrical conductivity is also observed in the uniaxially aligned MXene nanosheet film, which is quite different from the randomly oriented ones. The proposed orientation-controlling technique demonstrates potential for many applications including sensors, membranes, polarisers, and general energy applications.

17.
J Invasive Cardiol ; 34(9): E653-E659, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35863061

RESUMO

BACKGROUND: The optimal duration of dual-antiplatelet therapy (DAPT) after implantation of a drug-eluting stent (DES), especially recently developed polymer-free DESs, is unknown. This study examined the efficacy and safety of 3- versus 6-month DAPT in patients implanted with Coroflex ISAR polymer-free DESs. METHODS: Between May 2015 and August 2020, 488 patients who underwent Coroflex ISAR stent implantation were enrolled in the study and randomly assigned to the 3-month (n=244) or 6-month (n=244) DAPT group. RESULTS: At 1 year, the primary endpoint (composite of cardiovascular death, myocardial infarction, target vessel revascularization, and Bleeding Academic Research Consortium [BARC] type 2-5 bleeding) occurred in 9 (3.7%) patients in the 3-month DAPT group and in 7 (2.9%) patients in the 6-month DAPT group (hazard ratio 1.31; P=.60). There was no difference between the 3- and 6-month DAPT groups in either BARC type 2-5 bleeding (1.6% vs 0.8%; hazard ratio 2.00; P=.42) or any bleeding (2.9% vs 3.3%; hazard ratio 0.87; P=.80). CONCLUSION: Compared with 6 months of DAPT, 3 months of DAPT did not increase the risk of primary endpoint 1 year after Coroflex ISAR stent implantation, although it should be noted that the trial has limited power to see differences due to low event rate and low recruitment rate.


Assuntos
Stents Farmacológicos , Infarto do Miocárdio , Intervenção Coronária Percutânea , Quimioterapia Combinada , Stents Farmacológicos/efeitos adversos , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Humanos , Infarto do Miocárdio/epidemiologia , Intervenção Coronária Percutânea/efeitos adversos , Inibidores da Agregação Plaquetária/efeitos adversos , Estudos Prospectivos , Resultado do Tratamento
18.
Adv Mater ; 34(29): e2201749, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35661284

RESUMO

Topological solitons have knotted continuous field configurations embedded in a uniform background, and occur in cosmology, biology, and electromagnetism. However, real-time observation of their morphogenesis and dynamics is still challenging because their size and timescale are enormously large or tiny. Liquid crystal (LC) structures are promising candidates for a model-system to study the morphogenesis of topological solitons, enabling direct visualization due to the proper size and timescale. Here, a new way is found to rationalize the real-time observation of the generation and transformation of topological solitons using cholesteric LCs confined in patterned substrates. The experimental demonstration shows the topologically protected structures arise via the transformation of topological defects. Numerical modeling based on minimization of free energy closely reconstructs the experimental findings. The fundamental insights obtained from the direct observations pose new theoretical challenges in understanding the morphogenesis of different types of topological solitons within a broad range of scales.

19.
ACS Appl Mater Interfaces ; 14(3): 4409-4416, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35029362

RESUMO

A photonic lattice is an efficient platform for optically exploring quantum phenomena. However, its fabrication requires high costs and complex procedures when conventional materials, such as silicon or metals, are used. Here, we demonstrate a simple and cost-effective fabrication method for a reconfigurable chiral photonic lattice of the helical nanofilament (HNF) liquid crystal (LC) phase and diffraction grating showing wavelength-dependent diffraction with a rotated polarization state. Furthermore, the UV-exposed areas of the HNF film having chiral characteristics act as optical building blocks that induce resonant intensity modulation in the reflectance and transmittance modes and the optical rotation of the linear polarization. Our photonic lattice of the HNF can be an efficient platform for a chirality-embedded photonic lattice at a low cost.

20.
J Cell Biol ; 220(4)2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33570569

RESUMO

Histone posttranslational modifications (PTMs) are dynamic, context-dependent signals that modulate chromatin structure and function. Ubiquitin (Ub) conjugation to different lysines of histones H2A and H2B is used to regulate diverse processes such as gene silencing, transcriptional elongation, and DNA repair. Despite considerable progress made to elucidate the players and mechanisms involved in histone ubiquitination, there remains a lack of tools to monitor these PTMs, especially in live cells. To address this, we combined an avidity-based strategy with in silico approaches to design sensors for specifically ubiquitinated nucleosomes. By linking Ub-binding domains to nucleosome-binding peptides, we engineered proteins that target H2AK13/15Ub and H2BK120Ub with Kd values from 10-8 to 10-6 M; when fused to fluorescent proteins, they work as PTM sensors in cells. The H2AK13/15Ub-specific sensor, employed to monitor signaling from endogenous DNA damage through the cell cycle, identified and differentiated roles for 53BP1 and BARD1 as mediators of this histone PTM.


Assuntos
Histonas/metabolismo , Nucleossomos/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Linhagem Celular , Histonas/genética , Humanos , Nucleossomos/genética , Proteínas Supressoras de Tumor/genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...