Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Nat Commun ; 15(1): 387, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195614

RESUMO

Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe-down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is widely applicable across various ferroelectrics with different chemical compositions and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm-cm) size. These findings demonstrate that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.

2.
BMC Genomics ; 24(1): 580, 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37784038

RESUMO

BACKGROUND: Phenotypic plasticity is a crucial adaptive mechanism that enables organisms to modify their traits in response to changes in their environment. Predator-induced defenses are an example of phenotypic plasticity observed across a wide range of organisms, from single-celled organisms to vertebrates. In addition to morphology and behavior, these responses also affect life-history traits. The crustacean Daphnia galeata is a suitable model organism for studying predator-induced defenses, as it exhibits life-history traits changes under predation risk. To get a better overview of their phenotypic plasticity under predation stress, we conducted RNA sequencing on the transcriptomes of two Korean Daphnia galeata genotypes, KE1, and KB11, collected in the same environment. RESULTS: When exposed to fish kairomones, the two genotypes exhibited phenotypic variations related to reproduction and growth, with opposite patterns in growth-related phenotypic variation. From both genotypes, a total of 135,611 unigenes were analyzed, of which 194 differentially expressed transcripts (DETs) were shared among the two genotypes under predation stress, which showed consistent, or inconsistent expression patterns in both genotypes. Prominent DETs were related to digestion and reproduction and consistently up-regulated in both genotypes, thus associated with changes in life-history traits. Among the inconsistent DETs, transcripts encode vinculin (VINC) and protein obstructor-E (OBST-E), which are associated with growth; these may explain the differences in life-history traits between the two genotypes. In addition, genotype-specific DETs could explain the variation in growth-related life-history traits between genotypes, and could be associated with the increased body length of genotype KE1. CONCLUSIONS: The current study allows for a better understanding of the adaptation mechanisms related to reproduction and growth of two Korean D. galeata genotypes induced by predation stress. However, further research is necessary to better understand the specific mechanisms by which the uncovered DETs are related with the observed phenotypic variation in each genotype. In the future, we aim to unravel the precise adaptive mechanisms underlying predator-induced responses.


Assuntos
Daphnia , Transcriptoma , Animais , Feromônios , Rios , Genótipo , Peixes/genética , Comportamento Predatório , Variação Biológica da População , Perfilação da Expressão Gênica , República da Coreia
3.
Artigo em Inglês | MEDLINE | ID: mdl-37560994

RESUMO

A Gram-stain-negative, rod-shaped, polar flagellated, aerobic, light-yellow bacterium, designated as 2012CJ41-6T, was isolated from a sponge sample of Callyspongia elongata from Chuja-myeon, Jeju-si, Jeju-do, Republic of Korea. On the basis of 16S rRNA gene sequencing, strain 2012CJ41-6T clustered with species of the genus Ruegeria and appeared closely related to R. halocynthiae DSM 27839T (96.46 % similarity), R. denitrificans CECT 4357T (96.32 %), R. profundi ZGT108T (96.32 %), R. litorea CECT 7639T (96.32 %) and R. atlantica CECT 4292T (96.16 %). The average nucleotide identity and digital DNA-DNA hybridization between strain 2012CJ41-6T and the most closely related strain was 75.3 % and 19.6 %, indicating that 2012CJ41-6T represents a novel species of the genus Ruegeria. Growth occurred at 15-37 °C on marine medium in the presence of 0.5-10 % (w/v) NaCl and at pH 5.5-8.5. The DNA G+C content of the genomic DNA was 60.80 mol%, and ubiquinone-10 (Q-10) was the major respiratory quinone. The major cellular fatty acids (>5 %) were C18 : 1 ω7c and/or C18:1 ω6c (summed feature 8). The polar lipids consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid, one unidentified aminolipid, one unidentified aminophospholipid and five unidentified lipids. Physiological and biochemical characteristics indicated that strain 2012CJ41-6T represents a novel species of the genus Ruegeria, for which the name Ruegeria spongiae sp. nov. is proposed. The type strain is 2012CJ41-6T (=KACC 22645T=LMG 32585T).


Assuntos
Callyspongia , Rhodobacteraceae , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Callyspongia/microbiologia , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Filogenia , Rhodobacteraceae/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
4.
Adv Mater ; 35(29): e2212098, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37129959

RESUMO

Since the recognition of a significant oxygen-redox contribution to enhancing the capacity of Li transition-metal oxide cathodes, the oxygen release and subsequent structural variations together with capacity fading are critical issues to achieve better electrochemical performance. As most previous reports dealt with the structural degradation of cathodes after electrochemical cycling, it is fairly difficult to clarify how substantial the effect of lattice strain on the oxygen release will be while exclusively ruling out any electrochemical influences. By utilizing nanoindentation and mechanical surface polishing of single-crystal LiCoO2 and Li2 MnO3 , the local variations of both the atomic structure and oxygen content are scrutinized. Atomic-column-resolved imaging reveals that local LiM (M = Co and Mn) disordering and further amorphization are induced by mechanical strain. Moreover, substantial oxygen deficiency in the regions with these structural changes is directly identified by spectroscopic analyses. Ab initio density functional theory calculations also demonstrate energetically favorable formation of oxygen vacancies under shear strain. Providing direct evidence of oxygen release as a consequence of lattice strain, the findings in this work suggest that efficient strain relaxation will be of great significance for longevity of the anion framework in layered oxide cathodes.

5.
MRS Bull ; 47(8): 792-799, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36275428

RESUMO

Brittle fracture and ductile failure are critical events for any structural or functional component, as it marks the end of lifetime and potential hazard to human life. As such, materials scientists continuously strive to better understand and subsequently avoid these events in modern materials. A century after the seminal initial contribution by Griffith, fracture mechanics has come a long way and is still experiencing vivid progress. Building on classical fracture testing standards, advanced in situ fracture experiments allow local quantitative probing of fracture processes on different length scales, while microscopic analysis grants access to chemical and structural information along fracture paths in previously unseen detail. This article will provide an overview of how these modern developments enhance our understanding of local fracture processes and highlight future trends toward designing strong yet ductile and damage-tolerant materials.

6.
Adv Mater ; 34(35): e2200408, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35799313

RESUMO

Biological systems consist of hierarchical protein structures, each of which has unique 3D geometries optimized for specific functions. In the past decades, the growth of inorganic materials on specific proteins has attracted considerable attention. However, the use of specific proteins as templates has only been demonstrated in relatively simple organisms, such as viruses, limiting the range of structures that can be used as scaffolds. This study proposes a method for synthesizing metallic structures that resemble the 3D assemblies of specific proteins in mammalian cells and animal tissues. Using 1.4 nm nanogold-conjugated antibodies, specific proteins within cells and ex vivo tissues are labeled, and then the nanogold acts as nucleation sites for growth of metal particles. As proof of concept, various metal particles are grown using microtubules in cells as templates. The metal-containing cells are applied as catalysts and show catalytic stability in liquid-phase reactions due to the rigid support provided by the microtubules. Finally, this method is used to produce metal structures that replicate the specific protein assemblies of neurons in the mouse brain or the extracellular matrices in the mouse kidney and heart. This new biotemplating approach can facilitate the conversion of specific protein structures into metallic forms in ex vivo multicellular organisms.


Assuntos
Mamíferos , Metais , Animais , Catálise , Metais/química , Camundongos
7.
Nano Lett ; 22(1): 188-195, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34941273

RESUMO

We investigated the role of graphene interfaces in strengthening and toughening of the Cu-graphene nanocomposite by a combination of in situ transmission electron microscopy (TEM) deformation and molecular dynamics (MD) simulations. In situ TEM directly showed that dislocation plasticity is strongly confined within single Cu grains by the graphene interfaces and grain boundaries. The weak Cu-graphene interfacial bonding induces stress decoupling, which results in independent plastic deformation of each Cu layer. As confirmed by the MD simulation, the localized deformation made by such constrained dislocation plasticity results in the nucleation and growth of voids at the graphene interface, which acts as a precursor for crack. The graphene interfaces also effectively block crack propagation promoted by easy delamination of Cu layers dissipating the elastic strain energy. The toughening mechanisms revealed by the present study will provide valuable insights into the optimization of the mechanical properties of metal-graphene nanolayered composites.

8.
Cancer Res Treat ; 54(1): 269-276, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33887821

RESUMO

PURPOSE: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. MATERIALS AND METHODS: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. RESULTS: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). CONCLUSION: This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.


Assuntos
Antineoplásicos/administração & dosagem , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/mortalidade , Tretinoína/administração & dosagem , Adolescente , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Quimioterapia de Indução/métodos , Lactente , Contagem de Leucócitos , Masculino , Intervalo Livre de Progressão , Indução de Remissão , República da Coreia/epidemiologia , Estudos Retrospectivos , Resultado do Tratamento , Tretinoína/efeitos adversos
9.
Nanoscale ; 13(40): 16942-16951, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34635893

RESUMO

Decades of research on solute-induced phase transformation of metal hydride systems have shown the possibility to enhance hydrogen storage properties through novel material design such as nanoconfinement engineering. Nevertheless, the fundamentals of mechanical stress effect on confined Pd nanoparticles remain yet to be elucidated due to the difficulty in linking with hydrogen sorption thermodynamics. Here, a thermodynamic tuning of Pd nanocubes associated with hydrogen sorption as a result of encapsulation by reduced graphene oxide (rGO) layers is demonstrated. Pd nanocubes are constrained by rGO to such a degree that the chemical potential and the pressure hysteresis of the system during hydrogen sorption drastically change while showing a size dependence. A thorough thermodynamic analysis elucidates the role of constraints on hydrogen uptake and release; despite the nanoscale regime, the thermodynamic parameters (enthalpy and entropy) during phase transition considerably increase, a phenomenon not seen before in unconstrained Pd nanoparticle systems.

10.
Sleep Med ; 87: 62-68, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34520972

RESUMO

BACKGROUND: There is limited information on the association between weekend catch-up sleep (CUS), which has beneficial effects on health, and depression. This study aimed to investigate the association between CUS and depression in adults. METHODS: We used the data of the Seventh Korea National Health and Nutrition Examination Survey, 2016. Depression was defined as Patient Health Questionnaire-9 score ≥10. We categorized CUS duration as ≤0, 0 < to 1, 1 < to 2, and >2 h. RESULTS: Of 5550 eligible participants, 3286 (54.9%), 1033 (19.5%), 723 (14.7%) and 508 (10.9%) had CUS duration ≤0, 0 < to 1, 1 < to 2, and >2 h, respectively; of these, the prevalence of depression was 7.0%, 4.2%, 2.9%, and 6.0%, respectively. Multivariable regression analyses including covariates revealed that individuals with CUS duration 1 < to 2 h had a significantly decreased risk of depression compared to individuals with CUS duration ≤0 h (odds ratio [OR] = 0.517, 95% CI = 0.309-0.865). Individuals with CUS duration 0 < to 1 h (OR = 0.731, 95% CI = 0.505-1.060) and >2 h (OR = 1.164, 95% CI = 0.718-1.886) showed no significantly different risk of depression. CONCLUSIONS: The risk of depression in individuals with CUS duration 1 < to 2 h was lower than for those with CUS duration ≤0 h. This finding provides a better understanding on the association between CUS and depression; and can be a basis for better management of depression.


Assuntos
Depressão , Sono , Adulto , Depressão/epidemiologia , Humanos , Inquéritos Nutricionais , Prevalência , República da Coreia/epidemiologia
12.
Adv Mater ; 33(11): e2008353, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33527502

RESUMO

Native extracellular matrix (ECM) can exhibit cyclic nanoscale stretching and shrinking of ligands to regulate complex cell-material interactions. Designing materials that allow cyclic control of changes in intrinsic ligand-presenting nanostructures in situ can emulate ECM dynamicity to regulate cellular adhesion. Unprecedented remote control of rapid, cyclic, and mechanical stretching ("ON") and shrinking ("OFF") of cell-adhesive RGD ligand-presenting magnetic nanocoils on a material surface in five repeated cycles are reported, thereby independently increasing and decreasing ligand pitch in nanocoils, respectively, without modulating ligand-presenting surface area per nanocoil. It is demonstrated that cyclic switching "ON" (ligand nanostretching) facilitates time-regulated integrin ligation, focal adhesion, spreading, YAP/TAZ mechanosensing, and differentiation of viable stem cells, both in vitro and in vivo. Fluorescence resonance energy transfer (FRET) imaging reveals magnetic switching "ON" (stretching) and "OFF" (shrinking) of the nanocoils inside animals. Versatile tuning of physical dimensions and elements of nanocoils by regulating electrodeposition conditions is also demonstrated. The study sheds novel insight into designing materials with connected ligand nanostructures that exhibit nanocoil-specific nano-spaced declustering, which is ineffective in nanowires, to facilitate cell adhesion. This unprecedented, independent, remote, and cytocompatible control of ligand nanopitch is promising for regulating the mechanosensing-mediated differentiation of stem cells in vivo.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Fenômenos Mecânicos , Nanoestruturas , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Adesão Celular , Humanos , Ligantes , Fatores de Tempo
13.
Sci Rep ; 11(1): 2467, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510340

RESUMO

Cutaneous allodynia (CA) is a pain in response to non-nociceptive stimulation and a marker of central sensitisation. Probable migraine (PM) is a migraine subtype that fulfils all but one criterion of migraine. Headache intensity and the disability of individuals with PM are similar or lower than individuals with migraine. This study compared CA prevalence and characteristics of PM and migraine using a nationally representative sample in Korea. The Allodynia Symptom Checklist-12 (ASC-12) was used to assess CA (ASC-12 score ≥ 3). PM and migraine prevalence were 11.6% and 5.0%, respectively. CA prevalence did not significantly differ between PM and migraine (14.5% vs. 16.0%, p = 0.701). Participants with PM with CA reported a higher monthly headache frequency (3.3 ± 4.3 vs. 1.8 ± 3.6, p = 0.044), more severe headache intensity (Visuals Analogue Scale, 6.0 [4.0-7.0] vs. 5.0 [3.0-6.0], p = 0.002), and higher impact of headache (Headache Impact Test-6, 56.3 ± 7.2 vs. 48.3 ± 8.0, p < 0.001) than those without CA. Multiple regression analyses revealed that headache frequency and intensity, anxiety, and depression were significant factors for CA in participants with PM. In conclusion, CA prevalence among participants with PM and migraine were comparable. Anxiety, depression, and headache frequency and intensity were significant factors for CA in participants with PM.


Assuntos
Hiperalgesia , Transtornos de Enxaqueca , Adulto , Idoso , Feminino , Humanos , Hiperalgesia/complicações , Hiperalgesia/epidemiologia , Hiperalgesia/patologia , Hiperalgesia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Transtornos de Enxaqueca/epidemiologia , Transtornos de Enxaqueca/etiologia , Transtornos de Enxaqueca/patologia , Transtornos de Enxaqueca/fisiopatologia , Prevalência , República da Coreia/epidemiologia
14.
Nano Lett ; 21(1): 107-113, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33296220

RESUMO

Traditionally, the manipulation of contact mechanisms has been adopted as the primary strategy to tailor the friction properties of surfaces. On the contrary, the detaching process involving the local deformation and failure at the interface has been considered relatively less important. Here, we present a new approach toward the friction control of amorphous carbon through the plasticity and resultant transition of deformation mode on nanopatterned surfaces. Depending on the topography of the nanopatterns, the mechanical responses of the surfaces alter from elastic fracture to plastic flow, through which the friction coefficient changes by a factor of 5 without manipulation of the intrinsic structure of the material.

15.
Langmuir ; 36(51): 15552-15557, 2020 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-33325235

RESUMO

Although metal-phenolic species have emerged as one of the versatile material-independent-coating materials, providing attractive tools for interface engineering, mechanistic understanding of their film formation and growth still remains largely unexplored. Especially, the anions have been overlooked despite their high concentration in the coating solution. Considering that the anions are critical in the reactivity of metal-organic complex and the formation and/or property of functional materials, we investigated the anionic effects on the characteristics of film formation, such as film thickness and properties, in the Fe3+-tannic acid coating. We found that the film characteristics were strongly dictated by the counteranions (e.g., SO42-, Cl-, and Br-) of the Fe3+ ion. Specifically, the film thickness and properties (i.e., mechanical modulus, permeability, and stability) followed the reversed anionic Hofmeister series (Br- > Cl- > SO42-). Mechanistic studies suggested that more chaotropic anions, such as Br-, might induce a more widely extended structure of the Fe3+-TA complexes in the coating solution, leading to thicker, harder, but more porous films. The reversed anionic Hofmeister effect was further confirmed by the additive effects of various sodium salts (NaF, NaCl, NaBr, and NaClO4).

16.
Seizure ; 83: 13-16, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33075671

RESUMO

PURPOSE: Nasal pain, as an epileptic aura, has been poorly recognized. This study aims to demonstrate clinical features of patients with epilepsy who have nasal pain as an aura. METHODS: We retrospectively investigated consecutive patients who visited the epilepsy clinic of tertiary hospital from April 2000 to September 2019. All included patients underwent epilepsy-dedicated, high-resolution magnetic resonance imaging (MRI) examinations. All MRI studies were analyzed by visual inspection. RESULTS: Seven patients who presented nasal pain as an aura, were identified. Four patients reported nasal pain as the first aura. Four patients had right amygdala enlargement (isolated amygdala enlargement in three patients; amygdala enlargement in addition to hippocampal sclerosis in one patient), and one patient with compression of an internal carotid-posterior communicating artery aneurysm to right amygdala on brain MRI. Interictal epileptiform or ictal discharges on EEG were found in the right temporal region in five patients. In all four patients with amygdala enlargement, amygdala enlargement was ipsilateral to EEG anomalies. In all patients, nasal pain was accompanied by ictal semiological features, such as autonomic, olfactory, abdominal, or psychic auras, and focal impaired awareness seizures, which are typically associated with mesial temporal lobe epilepsy. CONCLUSIONS: Our findings suggest that nasal pain can occur as an epileptic aura in patients with temporal lobe epilepsy with probable involvement of the amygdala.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Dor/fisiopatologia , Lobo Temporal/fisiopatologia , Tonsila do Cerebelo/patologia , Eletroencefalografia/métodos , Epilepsia do Lobo Temporal/complicações , Humanos , Imageamento por Ressonância Magnética/métodos , Dor/complicações , Dor/patologia , Estudos Retrospectivos , Convulsões/complicações , Convulsões/fisiopatologia , Lobo Temporal/patologia
17.
Sci Rep ; 10(1): 18512, 2020 10 28.
Artigo em Inglês | MEDLINE | ID: mdl-33116223

RESUMO

Information on sex differences in the association between chronotype and depression is scarce. We aimed to investigate these differences using data from the Korea National Health and Nutrition Examination Survey in 2016. Chronotypes were categorised based on mid-sleep time on free days corrected by sleep debt accumulated on workdays (MSFsc): early type, < mean MSFsc - 1 standard deviation (SD); intermediate type, between mean MSFsc - 1 SD and MSFsc + 1 SD; and late type, > mean MSFsc + 1 SD. A Patient Health Questionnaire-9 score of ≥ 10 indicated depression. Among 5550 non-shift working adults aged 19-80 years, the prevalence rates of depression in the early, intermediate, and late chronotype groups were 7.4%, 4.5%, and 9.3%, respectively. Women with late chronotype (odds ratio [OR] = 2.9, 95% confidence interval [CI] = 1.8-4.7) showed a higher risk of depression than women with intermediate chronotype after adjusting for covariates. Women with early chronotype did not show a significant difference in depression risk (OR = 1.3, 95% CI = 0.9-2.0). In conclusion, late chronotype is associated with an increased risk of depression in women but not in men. Early chronotype is not associated with depression in women or men.


Assuntos
Ritmo Circadiano/fisiologia , Depressão/metabolismo , Sono/fisiologia , Adulto , Idoso , Depressão/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , República da Coreia/epidemiologia , Caracteres Sexuais , Fatores Sexuais , Transtornos do Sono-Vigília/fisiopatologia , Inquéritos e Questionários , Fatores de Tempo , Vigília/fisiologia
18.
J Med Internet Res ; 22(11): e23482, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-33031045

RESUMO

BACKGROUND: There has been growing international interest in performing remote consultations in primary care, particularly amidst the current COVID-19 pandemic. Despite this, the evidence surrounding the safety of remote consultations is inconclusive. The appropriateness of antibiotic prescribing in remote consultations is an important aspect of patient safety that needs to be addressed. OBJECTIVE: This study aimed to summarize evidence on the impact of remote consultation in primary care with regard to antibiotic prescribing. METHODS: Searches were conducted in MEDLINE, Embase, HMIC, PsycINFO, and CINAHL for literature published since the databases' inception to February 2020. Peer-reviewed studies conducted in primary health care settings were included. All remote consultation types were considered, and studies were required to report any quantitative measure of antibiotic prescribing to be included in this systematic review. Studies were excluded if there were no comparison groups (face-to-face consultations). RESULTS: In total, 12 studies were identified. Of these, 4 studies reported higher antibiotic-prescribing rates, 5 studies reported lower antibiotic-prescribing rates, and 3 studies reported similar antibiotic-prescribing rates in remote consultations compared with face-to-face consultations. Guideline-concordant prescribing was not significantly different between remote and face-to-face consultations for patients with sinusitis, but conflicting results were found for patients with acute respiratory infections. Mixed evidence was found for follow-up visit rates after remote and face-to-face consultations. CONCLUSIONS: There is insufficient evidence to confidently conclude that remote consulting has a significant impact on antibiotic prescribing in primary care. However, studies indicating higher prescribing rates in remote consultations than in face-to-face consultations are a concern. Further, well-conducted studies are needed to inform safe and appropriate implementation of remote consulting to ensure that there is no unintended impact on antimicrobial resistance.


Assuntos
Antibacterianos/uso terapêutico , Tratamento Farmacológico da COVID-19 , Atenção Primária à Saúde/métodos , Consulta Remota/métodos , SARS-CoV-2/efeitos dos fármacos , Adulto , Antibacterianos/farmacologia , Feminino , Humanos , Masculino
19.
ChemSusChem ; 13(16): 4159-4168, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32202384

RESUMO

Molybdenum-based compounds are considered as a potential replacement for expensive precious-metal electrocatalysts for the hydrogen evolution reaction (HER) in acid electrolytes. However, coating of thin films of molybdenum nitride or carbide on a large-area self-standing substrate with high precision is still challenging. Here, MoNx is uniformly coated on carbon cloth (CC) and nitrogen-doped carbon (NC)-modified CC (NCCC) substrates by atomic layer deposition (ALD). The as-deposited film has a nanocrystalline character close to amorphous and a composition of approximately Mo2 N with significant oxygen contamination, mainly at the surface. Among the as-prepared ALD-MoNx electrodes, the MoNx /NCCC has the highest HER activity (overpotential η≈236 mV to achieve 10 mA cm-2 ) owing to the high surface area and porosity of the NCCC substrate. However, the durability of the electrode is poor, owing to the poor adhesion of NC powder on CC. Annealing MoNx /NCCC in H2 atmosphere at 400 °C improves both the activity and durability of the electrode without significant change in the phase or porosity. Annealing at an elevated temperature of 600 °C results in formation of a Mo2 C phase that further enhances the activity (η≈196 mV to achieve 10 mA cm-2 ), although there is a huge reduction in the porosity of the electrode as a consequence of the annealing. The structure of the electrode is also systematically investigated by electrochemical impedance spectroscopy (EIS). A deviation in the conventional Warburg impedance is observed in EIS of the NCCC-based electrode and is ascribed to the change in the H+ ion diffusion characteristics, owing to the geometry of the pores. The change in porous nature with annealing and the loss in porosity are reflected in the EIS of H+ ion diffusion observed at high-frequency. The current work establishes a better understanding of the importance of various parameters for a highly active HER electrode and will help the development of a commercial electrode for HER using the ALD technique.

20.
ACS Appl Mater Interfaces ; 12(12): 14331-14340, 2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32017528

RESUMO

Although graphene has considerable potential as a next-generation transparent conducting electrode (TCE) material owing to its excellent optical transparency and flexibility, its electrical properties require further improvement for industrial application. This study reports a pathway of doping graphene by selective atomic layer deposition (ALD) of metals to elevate the electrical conductivity of graphene. Introduction of a novel Pt precursor [dimethyl(N,N-dimethyl-3-butene-1-amine-N)platinum(II); C8H19NPt; DDAP] facilitates a low-temperature (165 °C) process. The sheet resistance (Rs) of graphene is reduced significantly from 471 to 86.8 Ω sq-1 after 200 cycles of Pt ALD, while the optical transmittance at 550 nm (T) is maintained above 90% up to 200 cycles due to the selective growth of Pt on the defects of graphene. Furthermore, comprehensive analysis, including metal (Ru, Pt, and Ni) ALD on graphene, metal (Ru, Pt, Ni, Au, and Co) evaporation on graphene, and change in the ALD chemicals, demonstrates that ALD allows efficient graphene doping and the oxygen affinity of the metal is one of the key properties for efficient graphene doping. Finally, Pt ALD is applied to a multilayer graphene to further reduce Rs down to 75.8 Ω sq-1 yet to be highly transparent (T: 87.3%) after 200 cycles. In summary, the selective ALD of metals opens a way of improving the electrical properties of graphene to a level required for the industrial TCE application and has the potential to promote development of other types of functional metal-graphene composites.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...