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1.
Int Wound J ; 21(3): e14729, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38445793

RESUMO

We aimed to assess the quality and reliability of pressure injury-related videos uploaded on YouTube, analyse the sources and contents, and examine the correlation between video parameters. We searched YouTube using two keywords, "pressure ulcer" and "pressure sore", on August 20, 2022. We sorted the videos according to their number of views and included the top 100 videos for each keyword. The quality of videos was assessed using the Global Quality Scale (GQS), while their reliability was evaluated by the modified DISCERN (mDISCERN) tool. In addition, we evaluated the videos in which content was included, analysed the correlations and differences between GQS, mDISCERN, and video parameters. We initially found a total of 100 videos for each keyword and finally included and analysed 77 videos. The mean scores for the mDISCERN and GQS were 2.35 ± 0.98 and 3.09 ± 0.99, respectively. Both GQS and mDISCERN showed statistically significant correlations with each other (rho = 0.54, p < 0.0001*) and with the length of the videos, respectively (rho = 0.36, p = 0.001*), (rho = 0.29, p = 0.01*). Of the videos created by physicians, 8 (57.1%) included content related to treatment, while of the videos created by nonphysician health personnel, 22 (57.9%) included content related to prevention. Analysing whether there were differences in video parameters based on the sources, we observed significant differences between sources in GQS (p < 0.0001*), mDISCERN (p < 0.0001*), and video length (p = 0.001*). In the post-hoc analysis, videos uploaded by physicians or nonphysician health personnel showed higher quality and reliability than videos uploaded by other sources. Therefore, the results of this study could be useful for healthcare providers, as well as patients and caregivers, to search for high-quality and reliable YouTube videos related to pressure injury.


Assuntos
Úlcera por Pressão , Mídias Sociais , Humanos , Úlcera por Pressão/terapia , Reprodutibilidade dos Testes , Movimento Celular , Pessoal de Saúde
2.
Arch Phys Med Rehabil ; 104(2): 251-259, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36087805

RESUMO

OBJECTIVE: To investigate the chronic phase survival rate according to the frequency of rehabilitation treatment in the acute and subacute phases in stroke patients with severe functional limitations. DESIGN: A retrospective longitudinal cohort study. SETTING: Population-based study using the Korean National Health Insurance Database from 2007 to 2018. PARTICIPANTS: We enrolled 593 patients who experienced stroke in 2009 with national disability registration (NDR) grade of 3 or less (N=593). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: The frequencies of rehabilitation treatment within 24 months after stroke were categorized into none, 1-50, 51-200, 201-400, and >400 treatments based on requests made to the Health Insurance Review and Assessment Service. As a dependent variable, we assessed all-cause mortality from 24 to 120 months after stroke. RESULTS: The study enrolled 283 patients in NDR grade 1 (the most severe), 158 in grade 2, and 152 in grade 3. Groups with more severe functional limitations showed a lower chronic phase survival rate (P<.001). The groups with higher frequencies of rehabilitation treatment in the acute and subacute phases showed a higher chronic phase survival rate (P<.001). In the Cox regression analysis, a higher degree of functional limitation, lower frequency of rehabilitation treatment, older age, male sex, and chronic kidney disease were independent risk factors for chronic phase mortality in stroke patients with severe functional limitations. CONCLUSIONS: A high frequency of rehabilitation treatment in the acute and subacute phases was associated with the long-term survival of stroke patients with severe functional limitations.


Assuntos
Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral , Humanos , Masculino , Estudos Retrospectivos , Taxa de Sobrevida , Estudos Longitudinais
3.
BMC Geriatr ; 23(1): 61, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36721117

RESUMO

BACKGROUND: Cognitive decline is common in older adults and imposes a burden on public health. Especially for older adults, hospitalization can be related to decreased physical fitness. This study aimed to investigate the quantitative association between hospitalization and cognitive decline. METHODS: This was a retrospective cohort study. We performed a longitudinal study by using the combined database from the Korean National Health Insurance Service (NHIS) and memory clinic data of its self-run hospital. We identified whether hospitalized, the number of hospitalizations, and the total hospitalization days through the claim information from the NHIS database. We also identified whether hospitalization was accompanied by delirium or surgery with general anesthesia for subgroup analysis. Primary outcome was the clinical dementia rating-sum of boxes (CDR-SB) score. Secondary outcomes were mini-mental state examination (MMSE) score, clinical dementia rating (CDR) grade, and Korean-instrumental activities of daily living (KIADL) score. Multivariable mixed models were established. RESULTS: Of the 1810 participants, 1200 experienced hospitalization at least once during the observation period. The increase in CDR-SB was significantly greater in the hospitalized group (ß = 1.5083, P < .001). The same results were seen in the total number of hospitalizations (ß = 0.0208, P < .001) or the total hospitalization days (ß = 0.0022, P < .001) increased. In the group that experienced hospitalization, cognitive decline was also significant in terms of CDR grade (ß = 0.1773, P < .001), MMSE score (ß = - 1.2327, P < .001), and KIADL score (ß = 0.2983, P < .001). Although delirium (ß = 0.2983, P < .001) and nonsurgical hospitalization (ß = 0.2983, P < .001) were associated with faster cognitive decline, hospitalization without delirium and with surgery were also related to faster cognitive decline than in the no hospitalization group. CONCLUSION: Cognitive decline was quantitatively related to all-cause hospitalization in older adults. Moreover, hospitalizations without delirium and surgery were also related to cognitive decline. It is vital to prevent various conditions that need hospitalization to avoid and manage cognitive dysfunction.


Assuntos
Disfunção Cognitiva , Delírio , Humanos , Idoso , Estudos Longitudinais , Atividades Cotidianas , Estudos Retrospectivos , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/terapia , Programas Nacionais de Saúde
4.
Small ; 18(11): e2105611, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35064754

RESUMO

Numerous studies have explored new materials for electrocatalysts, but it is difficult to discover materials that surpass the catalytic activity of current commercially available noble metal electrocatalysts. In contrast to conventional transition metal alloys, high-entropy alloys (HEAs) have immense potential to maximize their catalytic properties because of their high stability and compositional diversity as oxygen evolution reactions (OERs). This work presents medium-entropy alloys (MEAs) as OER electrocatalysts to simultaneously satisfy the requirement of high catalytic activity and long-term stability. The surface of MEA electrocatalyst is tailored to suit the OER via anodizing and cyclic voltammetry activation methods. Optimized electrical properties and hydrophilicity of the surface enable an extremely low overpotential of 187 mV for achieving the current density of 10 mA cm-2 alkaline media. Furthermore, a combined photovoltaic-electrochemical system with MEA electrocatalyst and a perovskite/Si tandem solar cell exhibits a solar-to-hydrogen conversion efficiency of 20.6% for an unassisted hydrogen generation system. These results present a new pathway for designing sustainable high efficiency water splitting cells.

5.
J Korean Med Sci ; 37(32): e248, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35971762

RESUMO

BACKGROUND: Previous studies have reported an association between pneumonia risk and the use of certain drugs. We investigated the relationship between antihypertensive drugs and pneumonia in the general population. METHODS: This case-crossover study utilized the nationwide data of South Korea. We included participants who were hospitalized for pneumonia. A single case period was defined as 30 days before pneumonia onset, and two control periods were established (90-120 and 150-180 days before pneumonia onset). Further, we performed sensitivity and subgroup analyses (according to the presence of diabetes, documented disability, and whether participants were aged ≥ 70 years). We used conditional logistic regression models adjusted for covariates, such as angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), other antihypertensives, statins, antipsychotics, benzodiazepine, and the number of outpatient visits. RESULTS: In total, 15,463 subjects were included in this study. ACE inhibitors (adjusted odds ratio [aOR], 0.660; 95% confidence interval [CI], 0.558-0.781), ARBs (aOR, 0.702; 95% CI, 0.640-0.770), and other antihypertensive drugs (aOR, 0.737; 95% CI, 0.665-0.816) were significantly associated with reduced pneumonia risk. Subgroup analyses according to the presence of diabetes mellitus, documented disability, and whether participants were aged ≥ 70 years consistently showed the association of antihypertensives with a reduced risk of hospitalization for pneumonia. CONCLUSION: All antihypertensive drug types were related to a lower risk of hospitalization for pneumonia in the general population. Our results implied that frequent medical service usage and protective immunity were primarily related to a reduced risk of pneumonia in the general population of South Korea.


Assuntos
Anti-Hipertensivos , Hospitalização , Hipertensão , Pneumonia , Antagonistas de Receptores de Angiotensina/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Anti-Hipertensivos/uso terapêutico , Estudos Cross-Over , Humanos , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Programas Nacionais de Saúde , Pneumonia/tratamento farmacológico , Pneumonia/epidemiologia , República da Coreia/epidemiologia
6.
J Korean Med Sci ; 37(15): e112, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35437963

RESUMO

BACKGROUND: We aimed to examine the association between antihypertensive use and the incidence of hospitalized pneumonia in patients with a history of stroke. METHODS: In this case-crossover study, we obtained data from the Korean National Health Insurance Service-National Sample Cohort database. We included the data of patients with history of stroke who were admitted with a disease code of pneumonia. We analyzed the patients' exposure to antihypertensives in the 30 (single case period), 90-120, and 150-180 days (2 control periods) before the onset of pneumonia using conditional logistic regression analysis. Additionally, sensitivity analysis and subgroup analysis according to diabetes status, age, and documented disability were performed. RESULTS: Angiotensin II receptor blocker (ARB) use was associated with a reduced risk of hospitalized pneumonia (adjusted odds ratio [OR] [95% confidence interval; 95% CI]: 0.718 [0.576-0.894]). However, the use of angiotensin converting enzyme inhibitors and other antihypertensives were not associated with a change in hospitalized pneumonia incidence (adjusted OR [95% CI]: 0.902, [0.603-1.350] and 0.788 [0609-1.018], respectively). Subgroup analysis revealed that ARB use was associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke who were older than 65 years, but not in younger (≤ 65 years) group (adjusted OR [95% CI]: 0.687 [0.536-0.880]). CONCLUSION: ARB use is associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke, especially in older adults.


Assuntos
Hipertensão , Pneumonia , Acidente Vascular Cerebral , Idoso , Antagonistas de Receptores de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Estudos de Coortes , Estudos Cross-Over , Humanos , Hipertensão/complicações , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Pneumonia/complicações , Pneumonia/tratamento farmacológico , Pneumonia/epidemiologia , República da Coreia/epidemiologia , Estudos Retrospectivos , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia
7.
J Korean Med Sci ; 37(49): e354, 2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36536548

RESUMO

BACKGROUND: Early-onset dementia (EOD) is still insufficiently considered for healthcare policies. We investigated the effect of socio-environmental factors on the long-term survival of patients with EOD. METHODS: This retrospective cohort study utilized the Korean National Health Insurance Database from 2007 to 2018. We enrolled 3,825 patients aged 40 to 65 years old with all types of dementia newly diagnosed in 2009 as EOD cases. We defined socioeconomic status using the national health insurance premium (NHIP) levels. Residential areas were classified into capital, metropolitan, city, and county levels. All-cause mortality was the primary outcome. Kaplan-Meier curves and log-rank tests were employed. Further, Cox-proportional hazards models were established. RESULTS: The mean survival of the fourth NHIP level group was 96.31 ± 1.20 months, whereas that of the medical-aid group was 85.53 ± 1.30 months (P < 0.001). The patients living in the capital had a mean survival of 95.73 ± 1.34 months, whereas those living in the county had 89.66 ± 1.75 months (P = 0.035). In the Cox-proportional hazards model, the medical-aid (adjusted hazard ratio [aHR], 1.67; P < 0.001), first NHIP level (aHR, 1.26; P = 0.012), and second NHIP level (aHR, 1.26; P = 0.008) groups were significantly associated with a higher long-term mortality risk. The capital residents exhibited a significantly lower long-term mortality risk than did the county residents (aHR, 0.82; P = 0.041). CONCLUSION: Socioeconomic status and residential area are associated with long-term survival in patients with EOD. This study provides a rational basis for establishing a healthcare policy for patients with EOD.


Assuntos
Demência , Classe Social , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Retrospectivos , Modelos de Riscos Proporcionais , Programas Nacionais de Saúde , República da Coreia , Fatores de Risco
8.
Sci Technol Adv Mater ; 23(1): 579-586, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36212683

RESUMO

Metastability engineering is a strategy to enhance the strength and ductility of alloys via deliberately lowering phase stability and prompting deformation-induced martensitic transformation. The advantages of the strategy are widely exploited by ferrous medium-entropy alloys (MEAs) that exhibit phase transformation from metastable face-centered cubic (FCC) to hexagonal close-packed (HCP) or body-centered cubic (BCC) martensite and a significant increase in work hardening. Fe50Co25Ni10Al5Ti5Mo5 (at%) MEA is an example of such materials, which shows ~1.5 GPa of tensile strength assisted by exceptional work hardening from the deformation-induced BCC martensitic transformation. In this work, the martensitic transformation and its effect on the mechanical response of the MEA were studied by in situ neutron diffraction under tensile loading. Strain-induced BCC martensite started forming rapidly from the beginning of plastic deformation, reaching a phase fraction of ~100% when deformed to ~10% of true strain. Lattice strain and phase stress evolution indicate that stress was dynamically partitioned onto the newly formed BCC martensite, which is responsible for the work hardening response and high flow stress of the MEA. This work shows how great a role FCC to BCC martensitic transformation can play in enhancing the mechanical properties of ferrous MEAs.

9.
Nano Lett ; 21(13): 5819-5827, 2021 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-34189918

RESUMO

Stretchable electronics have been spotlighted as promising next-generation electronics. In order to drive a specific unit device in an integrated stretchable device, the interconnection of the device should be placed in a desired position and addressed individually. In addition, practical stretchable interconnection requires reliable stretchability, high conductivity, optical transparency, high resolution, and fast and large-scale production. This study proposes an approach to meet these requirements. We print the single wavy polymer nanofibers (NFs) in a desired position and convert them into metal NF interconnections. The nanoscale diameter and the wavy cylindrical shape of the metal NFs are the main reasons for the reliable stretchability and the excellent transparency. Using the stretchable metal NFs and the stretchable organic semiconductor NFs, an array of all-stretchable transparent NF-field effect transistors (NF-FETs) is demonstrated. The highly integrated NF-FET array (10 FETs/mm2) shows uniform performance and good stability under repeated severe mechanical deformations.

10.
Emerg Infect Dis ; 26(10): 2338-2345, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32568663

RESUMO

As a part of measures to decrease spikes in coronavirus disease (COVID-19) cases and deaths outside of hospitals, the government of South Korea introduced a plan for community treatment centers (CTCs) to isolate and monitor patients with mild COVID-19 symptoms. We assessed outcomes of 568 patients admitted to 3 CTCs near Daegu. More (64.6%) women than men (35.4%) were admitted, and the mean age of patients was 36.0 years (SD +15.0 years). Among all patients, 75.7% remained asymptomatic while at the CTCs. The mean time patients remained at CTCs was 19.6 days (SD +5.8 days) from the day of diagnosis until our study ended on March 23, 2020. Because they offer appropriate clinical triaging and daily monitoring for patients, CTCs are a safe alternative to medical institutions for asymptomatic or mildly symptomatic patients with COVID-19.


Assuntos
Centros Comunitários de Saúde/estatística & dados numéricos , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Isolamento de Pacientes/métodos , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Adulto , Idoso , Infecções Assintomáticas , Betacoronavirus/isolamento & purificação , COVID-19 , Pré-Escolar , Centros Comunitários de Saúde/organização & administração , Comorbidade , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Transferência de Pacientes , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/estatística & dados numéricos , República da Coreia/epidemiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/estatística & dados numéricos , SARS-CoV-2
11.
Acta Radiol ; 61(12): 1661-1667, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32202135

RESUMO

BACKGROUND: The acromion index (AI) is the acromial lateral extension above the head of the humerus. Some researchers have advocated that the AI indicates the severity of the tear size of the full-thickness supraspinatus tendon. PURPOSE: To validate the reproducibility of the AI between shoulder magnetic resonance imaging (MRI) and standard X-ray and to verify whether the AI is a useful index for stratifying the severity of supraspinatus tendon injuries, as well as full-thickness tears. MATERIAL AND METHODS: We enrolled 200 patients with impingement syndrome who were subsequently evaluated with standard X-ray of the shoulder in the anteroposterior view, as well as an MRI. We performed a pilot study to validate the reproducibility of the AI using standard X-ray and MRI, and to compare the AI between these imaging modalities. The severity of supraspinatus tendon injury was classified into four groups (0 = no evidence of injury, 1 = partial tear, 2 = full-thickness tear, and 3 = complete rupture) based on an official reading of the shoulder MRI. We compared the AIs of both modalities between the groups. RESULTS: Intraclass correlation coefficients of the AIs between the two examiners were 0.819 for MRI and 0.808 for plain X-ray. The mean AI from standard X-ray was greater than that from MRI (P<0.0001). There was no statistical correlation between the AI and the severity of supraspinatus tendon injury. CONCLUSION: Our findings indicate that the AI cannot be generally used as a predictive reference for the stratified severities of supraspinatus tendon injury.


Assuntos
Acrômio/diagnóstico por imagem , Acrômio/lesões , Imageamento por Ressonância Magnética , Índice de Gravidade de Doença , Traumatismos dos Tendões/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes
12.
Medicina (Kaunas) ; 56(12)2020 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-33260421

RESUMO

Background and objectives: We aimed to analyze factors associated with the period of viral shedding in patients with confirmed COVID-19 who experienced only mild symptoms. Materials and methods: We conducted a multicenter retrospective study from three community treatment centers (CTCs) of South Korea. All patients included were admitted to the three centers before 31 March 2020. We collected data about clinical characteristics and the result of real-time reverse transcription polymerase chain reaction (RT-PCR). Results: Viral shedding was terminated within 32 days and 36 days in 75% and 90% of patients, respectively (range: 8-49 days). The mean period of viral shedding was 23.8 ± 8.7 days. In the multivariate Cox proportional hazards regression analysis, the existence of underlying comorbidities lowered the probability of the termination of viral shedding (HR = 0.561, 95% CI 0.388-0.812). Female sex and presence of COVID-19-associated symptoms also lowered the probability, but the significance was marginal. Conclusions: The existence of underlying comorbidities was associated with delayed termination of viral shedding in COVID-19 patients with mild severity.


Assuntos
Infecções Assintomáticas , COVID-19/transmissão , Isolamento de Pacientes , SARS-CoV-2 , Eliminação de Partículas Virais , Adulto , COVID-19/diagnóstico , COVID-19/fisiopatologia , Teste de Ácido Nucleico para COVID-19 , Comorbidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , República da Coreia , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
13.
Acta Radiol ; 60(5): 608-614, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30111192

RESUMO

BACKGROUND: Rotator cuff tear (RCT) has been believed to be related to specific types of the acromion. However, most of the studies were performed on a small number of patients with surgical findings not considering the severity of RCT. PURPOSE: To analyze the relationship between age, gender, the side of the shoulder, the acromion type, and the severity of RCT using shoulder magnetic resonance arthrography (MRA). MATERIAL AND METHODS: A total of 277 shoulder MRA findings were analyzed by a radiologist specializing in the musculoskeletal system. The relationship between variables (age, gender, side of the shoulder, and acromion type) and the injury of the supraspinatus (no rupture, partial rupture, full rupture, complete rupture) was confirmed. The partial tear of the supraspinatus tendon was divided into bursal and articular side tear in order to investigate the damage caused by the anatomical difference of the acromion. We also confirmed the differences between single supraspinatus injury and multiple RCTs. RESULTS: The severity of supraspinatus tear and multiple RCTs were statistically significant with the old age and the right side of the shoulder, but not with a specific acromion type. In supraspinatus partial tear, there was no statistical difference between bursal and articular side tears. CONCLUSION: Our study revealed that the age at which degeneration could occur also was associated with multiple RCTs and is considered to be the most important factor in RCT, not anatomical structures such as acromion type.


Assuntos
Acrômio/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Lesões do Manguito Rotador/diagnóstico por imagem , Fatores Etários , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Manguito Rotador/diagnóstico por imagem , Índice de Gravidade de Doença , Fatores Sexuais
16.
Entropy (Basel) ; 20(11)2018 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-33266573

RESUMO

Annealing of severely plastic deformed materials is expected to produce a good combination of strength and ductility, which has been widely demonstrated in conventional materials. In the present study, high-pressure torsion processed CoCrNi medium entropy alloy consisting of a single face-centered cubic (FCC) phase with a grain size of ~50 nm was subjected to different annealing conditions, and its effect on microstructure and mechanical behavior was investigated. The annealing of high-pressure torsion processed CoCrNi alloy exhibits partial recrystallization and near full recrystallization based on the annealing temperature and time. The samples annealed at 700 °C for 2 min exhibit very fine grain size, a high fraction of low angle grain boundaries, and high kernel average misorientation value, indicating partially recrystallized microstructure. The samples annealed for a longer duration (>2 min) exhibit relatively larger grain size, a low fraction of low angle grain boundaries, and low kernel average misorientation value, indicating nearly full recrystallized microstructure. The annealed samples with different microstructures significantly influence the uniform elongation, tensile strength, and work hardening rate. The sample annealed at 700 °C for 15 min exhibits a remarkable combination of tensile strength (~1090 MPa) and strain to failure (~41%).

17.
Small ; 10(18): 3678-84, 2014 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-24832671

RESUMO

Lattice distortion induced by residual stresses can alter electronic and mechanical properties of materials significantly. Herein, a novel way of the bandgap tuning in a quantum dot (QD) by lattice distortion is presented using 4-nm-sized CdS QDs grown on a TiO2 particle as an application example. The bandgap tuning (from 2.74 eV to 2.49 eV) of a CdS QD is achieved by suitably adjusting the degree of lattice distortion in a QD via the tensile residual stresses which arise from the difference in thermal expansion coefficients between CdS and TiO2. The idea of bandgap tuning is then applied to QD-sensitized solar cells, achieving ≈60% increase in the power conversion efficiency by controlling the degree of thermal residual stress. Since the present methodology is not limited to a specific QD system, it will potentially pave a way to unexplored quantum effects in various QD-based applications.

18.
Nanotechnology ; 25(5): 055205, 2014 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-24406901

RESUMO

Phase change random access memory (PCRAM) devices are usually constructed using tellurium based compounds, but efforts to seek other materials providing desirable memory characteristics have continued. We have fabricated PCRAM devices using Ga-doped In2O3 nanowires with three different Ga compositions (Ga/(In+Ga) atomic ratio: 2.1%, 11.5% and 13.0%), and investigated their phase switching properties. The nanowires (∼40 nm in diameter) can be repeatedly switched between crystalline and amorphous phases, and Ga concentration-dependent memory switching behavior in the nanowires was observed with ultra-fast set/reset rates of 80 ns/20 ns, which are faster than for other competitive phase change materials. The observations of fast set/reset rates and two distinct states with a difference in resistance of two to three orders of magnitude appear promising for nonvolatile information storage. Moreover, we found that increasing the Ga concentration can reduce the power consumption and resistance drift; however, too high a level of Ga doping may cause difficulty in achieving the phase transition.

19.
Int J Gen Med ; 17: 1625-1633, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38706744

RESUMO

Purpose: Clinical studies on dysbiosis and stroke outcomes has been insufficient to establish clear evidence. This study aimed to investigate the effects of pre-antibiotic use before a stroke event on secondary outcomes using a longitudinal population-level database. Patients and Methods: This retrospective cohort study included adults aged 55 years or older diagnosed with acute ischemic stroke (AIS) and acute hemorrhagic stroke (AHS) between 2004 and 2007. Patients were followed-up until the end of 2019, and the target outcomes were secondary AIS, AHS, and all-cause mortality. Multivariable Cox regression analyses were applied, and we adjusted covariates such as age, sex, socioeconomic status, hypertension, diabetes, and dyslipidemia. Pre-antibiotic use was identified from 7 days to 1 year before the acute stroke event. Results: We included 159,181 patients with AIS (AIS group) and 49,077 patients with AHS (AHS group). Pre-antibiotic use significantly increased the risk of secondary AIS in the AIS group (adjusted hazard ratio [aHR], 1.03; 95% confidence interval [CI], 1.01-1.05; p = 0.009) and secondary AHS in the AHS group (aHR, 1.08; 95% CI, 1.03-1.12; p <0.001). Furthermore, pre-antibiotic use in the AIS group was associated with a lower risk of mortality (aHR, 0.95; 95% CI, 0.94-0.96; p <0.001). Conclusion: Our population-based longitudinal study revealed that pre-antibiotic use was associated with a higher risk of secondary stroke and a lower risk of mortality in the AIS and AHS groups. Further studies are needed to understand the relationship between dysbiosis and stroke outcomes.

20.
Medicine (Baltimore) ; 103(7): e37244, 2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38363883

RESUMO

RATIONALE: The incidence of a schwannoma within the psoas muscle is rare, and only a few cases have been reported. The surgical approach to removing schwannomas present in the psoas muscle is challenging because of its anatomical proximity to the lumbar plexus. PATIENT CONCERNS: A 31-year-old man experienced right lower back pain and anterolateral thigh numbness for 2 months. DIAGNOSIS: Magnetic resonance imaging of the patient's lumbar spine revealed a mass lesion, which was radiologically diagnosed as a well-demarcated schwannoma. INTERVENTIONS: The patient underwent surgery for excision of the schwannoma in the right psoas muscle at the second to fourth lumbar vertebrae levels. During surgery, intraoperative neurophysiological monitoring modalities, free-running and triggered electromyography and evoked potentials, from the target muscles were recorded. OUTCOMES: There was no neurotonic discharge corresponding to neuronal injury. Compound motor nerve action potential was detected in the triggered electromyography of muscles around the medial margin of the tumor. However, direct integration of the motor nerve was not observed in the intra-tumor region. LESSONS: We report that schwannoma removal in the psoas muscle, which is adjacent to the lumbar plexus, can be safely performed using intraoperative neurophysiological monitoring.


Assuntos
Monitorização Neurofisiológica Intraoperatória , Neurilemoma , Masculino , Humanos , Adulto , Monitorização Neurofisiológica Intraoperatória/métodos , Músculos Psoas/cirurgia , Músculos Psoas/patologia , Procedimentos Neurocirúrgicos , Vértebras Lombares/cirurgia , Neurilemoma/cirurgia , Neurilemoma/patologia
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