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2.
J Hosp Infect ; 135: 171-178, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36934790

RESUMO

BACKGROUND: Disinfection of gloves might reduce the workload of healthcare workers, protect the environment, and bring economic benefits. Thus, the safety of hand hygiene of gloved hands is an important issue. AIM: We aimed to evaluate the risk of microbial transmission by comparing residual micro-organisms after multiple patient contacts, with or without gloves, in clinical practice. METHODS: Researchers, two with gloved hands (single or double gloves) and one with bare hands, made rounds of patients, followed by alcohol-based hand rub. Hand imprints were obtained before and after the rounds and cultured. The number of colony-forming units (cfu) of gloved and bare hands was compared, and the colony distribution was evaluated semi-quantitatively by hand region. FINDINGS AND CONCLUSION: A total of 108 imprints were obtained after 10 rounds. The median cfu counts were significantly higher in the gloved hands (single and double) than in the bare hands (9.00 vs 3.50, P=0.028). The cfu counts of single- and double-gloved hands were higher after than before contact (P=0.044 and P=0.001, respectively). Carbapenem-resistant Acinetobacter baumannii was identified in a pair of double gloves after a round, which included patients with the same organism with identical antibiotic susceptibility results. The mean percentage of colony-growing compartments from gloved hands was significantly higher than that of bare hands in the finger and wrist regions (P=0.019 and P=0.049, respectively). Compared with bare hands, reuse of gloves increased residual microbial colonies and potential for transmission of multi-drug-resistant organisms, even after using alcohol-based hand rub.


Assuntos
Higiene das Mãos , Humanos , Higiene das Mãos/métodos , Mãos , Desinfecção/métodos , Etanol , 2-Propanol , Desinfecção das Mãos/métodos , Luvas Protetoras , Contagem de Colônia Microbiana
3.
Qual Life Res ; 32(7): 2047-2058, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36897529

RESUMO

PURPOSE: The standard recall period for the patient-reported outcomes version of the common terminology criteria for adverse events (PRO-CTCAE®) is the past 7 days, but there are contexts where a 24-hour recall may be desirable. The purpose of this analysis was to investigate the reliability and validity of a subset of PRO-CTCAE items captured using a 24-hour recall. METHODS: 27 PRO-CTCAE items representing 14 symptomatic adverse events (AEs) were collected using both a 24-hour recall (24 h) and the standard 7 day recall (7d) in a sample of patients receiving active cancer treatment (n = 113). Using data captured with a PRO-CTCAE-24h on days 6 and 7, and 20 and 21, we computed intra-class correlation coefficients (ICC); an ICC ≥ 0.70 was interpreted as demonstrating high test-retest reliability. Correlations between PRO-CTCAE-24h items on day 7 and conceptually relevant EORTC QLQ-C30 domains were examined. In responsiveness analysis, patients were deemed changed if they had a one-point or greater change in the corresponding PRO-CTCAE-7d item (from week 0 to week 1). RESULTS: PRO-CTCAE-24h captured on two consecutive days demonstrated that 21 of 27 items (78%) had ICCs ≥ 0.70 (day 6/7 median ICC 0.76), (day 20/21 median ICC 0.84). Median correlation between attributes within a common AE was 0.75, and the median correlation between conceptually relevant EORTC QLQ-C30 domains and PRO-CTCAE-24 h items captured on day 7 was 0.44. In the analysis of responsiveness to change, the median standardized response mean (SRM) for patients with improvement was - 0.52 and that for patients with worsening was 0.71. CONCLUSION: A 24-hour recall period for PRO-CTCAE items has acceptable measurement properties and can inform day-to-day variations in symptomatic AEs when daily PRO-CTCAE administration is implemented in a clinical trial.


Assuntos
Antineoplásicos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Neoplasias , Humanos , Antineoplásicos/uso terapêutico , Reprodutibilidade dos Testes , Sistemas de Notificação de Reações Adversas a Medicamentos , Qualidade de Vida/psicologia , Neoplasias/terapia , Medidas de Resultados Relatados pelo Paciente , Inquéritos e Questionários
4.
Anaesthesia ; 77(9): 1010-1017, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35727620

RESUMO

Numerous studies support the idea that neuromuscular blockade facilitates facemask ventilation after induction of anaesthesia. Although improved airway patency or pulmonary compliance and a resolution of laryngospasm have been suggested as possible causes, the exact mechanism remains unclear. We aimed to assess whether neuromuscular blockade improves facemask ventilation and to clarify whether this phenomenon is associated with the vocal cord angle. This prospective observational study included patients aged between 20 and 65 years scheduled for elective surgery under general anaesthesia. After induction of anaesthesia, patients' lungs were ventilated with pressure-controlled ventilation using a facemask. During facemask ventilation, a flexible bronchoscope was inserted through a self-sealing diaphragm at the elbow connector attached to the facemask and breathing circuit and positioned to allow a continuous view of the vocal cords. The mean tidal volume and vocal cord angle were measured before and after administration of neuromuscular blocking drugs. Of 108 patients, 100 completed the study. Mean (SD) tidal volume ((11.0 (3.9) ml.kg-1 vs. 13.6 (2.6) ml.kg-1 ; p < 0.001) and mean (SD) vocal cord angle (17° (10°) vs. 26° (5°); p < 0.001) increased significantly after neuromuscular blockade. The proportional increase in mean tidal volume after neuromuscular blockade was positively correlated with vocal cord angle (Spearman's ρ = 0.803; p < 0.001). In conclusion, neuromuscular blockade facilitated facemask ventilation, and the improvement was correlated with further opening of the vocal cords.


Assuntos
Bloqueio Neuromuscular , Adulto , Idoso , Anestesia Geral , Humanos , Pulmão , Máscaras , Pessoa de Meia-Idade , Prega Vocal , Adulto Jovem
5.
J Hosp Infect ; 115: 59-63, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34098050

RESUMO

The increasing number of coronavirus disease 2019 (COVID-19) cases in the community has posed a significant epidemic pressure on healthcare settings. When healthcare workers (HCWs) acquire COVID-19, contact tracing and epidemiological investigation might not be adequate for determining the source of transmission. Here, we report a phylogenetic investigation involving two infected HCWs and nine patients to determine whether patient-to-HCW transmission had occurred in a hospital without a previous COVID-19 outbreak. This is the first study to apply phylogenomics to investigate suspected nosocomial transmission in a region with low prevalence of COVID-19. Our results do not support the occurrence of direct patient-to-HCW transmission.


Assuntos
COVID-19 , Surtos de Doenças , Pessoal de Saúde , Humanos , Filogenia , SARS-CoV-2
7.
Int J Tuberc Lung Dis ; 25(3): 191-198, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33688807

RESUMO

BACKGROUND: Extrapulmonary TB (EPTB) is more difficult to diagnose than pulmonary TB. The delayed management of EPTB can lead to complications and increase the socio-economic burden.METHODS: Patients newly diagnosed with EPTB were retrospectively enrolled from 11 general hospitals in South Korea from January 2017 to December 2018. The basic characteristics of patients were described. Univariable and multivariable analyses were performed between early and delayed diagnosis groups to identify risk factors for delayed diagnosis and treatment in EPTB.RESULTS: In total, 594 patients were enrolled. Lymph node TB (28.3%) was the predominant form, followed by abdominal (18.4%) and disseminated TB (14.5%). Concurrent lung involvement was 17.8%. The positivity of diagnostic tests showed no significant difference between the two groups. Acute clinical manifestations in disseminated, pericardial and meningeal TB, and immunosuppression were associated with early diagnosis. Delayed diagnosis was associated with outpatient clinic visits, delayed sample acquisition and diagnostic departments other than infection or pulmonology.CONCLUSION: The delay in diagnosis and treatment of EPTB was not related to differences in microbiological characteristics of Mycobacterium tuberculosis itself; rather, it was due to the indolent clinical manifestations that cause referral to non-TB-specialised departments in the outpatient clinic and delay the suspicion of TB and diagnostic testing.


Assuntos
Diagnóstico Tardio , Tuberculose Extrapulmonar , Humanos , Mycobacterium tuberculosis , República da Coreia/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Tuberculose Extrapulmonar/diagnóstico
8.
Sci Rep ; 11(1): 4807, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33637955

RESUMO

In this study, we investigate metallic nanocomposites to elucidate the properties of nanostructured conventional superconductors. Liquid tin, indium, and mercury are loaded into opal matrices by high pressure up to 10 kbar. The opal templates preserve the 3D dendritic morphology of confined superconducting metals to model a dendritic second phase with particular grain shape in bulk superconductors observed by a DualBeam microscope. We carry out measurements of the dc and ac magnetizations to study the superconducting phase diagrams, vortex dynamics, and impact of grain morphology in the opal composites. Besides, we apply the small-angle neutron scattering (SANS) to deny a regular vortex structure. The phase diagrams reveal an enhanced upper critical field Hc2(0) and curvature crossover in the upper critical field line. We also calculate the vortex activation barriers Ua and observe a transformation in the vortex system. According to the field dependence of Ua, the vortex structure transformation highly correlates with the curvature crossover in the upper critical field line. Our observations suggest that the similarity in the normalized phase diagrams and field dependences of Ua in the three nanocomposites is owing to their particular morphology of confinement.

9.
J Hosp Infect ; 108: 81-89, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33181278

RESUMO

BACKGROUND: Restricting urine culture to patients with genuine urinary tract infection (UTI) reduces excessive antimicrobial prescription for asymptomatic bacteriuria. AIM: To evaluate the impact of urine culture diagnostic stewardship on antimicrobial consumption. METHODS: This quasi-study involved two general hospitals and 10 community clinics. In the pre-intervention (control) phase (25th November 2018-2nd February 2019), microscopy and culture results of all urine specimens were reported. In the post-intervention (study) phase (25th November 2019-2nd February 2020), urine cultures were processed and reported only if at least one of the following criteria were met: presence of white blood cells or bacteria on microscopy; patient from obstetrics, urology, paediatrics, oncology or renal transplant ward; specimen labelled as 'pregnancy', 'urological procedure', 'renal transplant' or 'neutropenic'; and ureteric, nephrostomy or suprapubic urine. For urine samples that did not fulfil these criteria, the microscopy results and a rejection comment were reported. FINDINGS: In total, 12,282 urine specimens were included in the intervention phase. Of these, 4757 (38.7%) specimens did not fulfil the screening criteria, and the microscopy result and a rejection comment were reported. One hundred and sixty-three (3.4%) of these non-reported urine cultures yielded significant bacterial growth, and the majority were Escherichia coli (N=58, 35.6%). Diagnostic stewardship was independently associated with lower antimicrobial consumption [adjusted odds ratio 0.76, 95% confidence interval (CI) 0.70-0.83, P<0.001] on multi-variable logistic regression across all healthcare settings. Diagnostic stewardship had no effect on patient mortality (adjusted hazard ratio=0.95, 95% CI 0.89-1.01, P=0.08). No patients with unreported urine culture developed bacteraemia from untreated UTI. CONCLUSION: Diagnostic stewardship of urine culture safely reduced excessive antimicrobial prescription for asymptomatic bacteriuria.


Assuntos
Anti-Infecciosos/administração & dosagem , Gestão de Antimicrobianos , Bacteriúria/tratamento farmacológico , Prescrições/estatística & dados numéricos , Infecções Urinárias/tratamento farmacológico , Humanos , Urinálise
10.
AJNR Am J Neuroradiol ; 41(9): 1698-1702, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32763901

RESUMO

BACKGROUND AND PURPOSE: Although olfactory dysfunction is a common cranial nerve disorder, there are no simple objective morphometric criteria to assess olfactory dysfunction. The aim of this study was to evaluate the diagnostic performance of MR imaging morphometric parameters for detecting olfactory dysfunction. MATERIALS AND METHODS: This prospective study enrolled patients from those presenting with olfactory symptoms who underwent both an olfactory function test and MR imaging. Controls without olfactory dysfunction were recruited during the preoperative work-up for pituitary adenoma. Two independent neuroradiologists measured the olfactory bulb in 3D and assessed olfactory bulb concavity on MR imaging while blinded to the clinical data. Diagnostic performance was assessed using receiver operating characteristic curve analysis. RESULTS: Sixty-four patients and 34 controls were enrolled. The patients were significantly older than the controls (mean age, 57.8 ± 11.9 years versus 47.1 ± 12.1 years; P < .001). Before age adjustment, the olfactory bulb height was the only olfactory bulb parameter showing a significant difference between patients and controls (1.6 ± 0.3 mm versus 2.0 ± 0.3 mm, P < .001). After age adjustment, all parameters and olfactory bulb concavity showed significant intergroup differences, with the olfactory bulb height having the highest area under the curve (0.85). Olfactory bulb height was confirmed to be the only significant parameter showing a difference in the detection of olfactory dysfunction in 22 pairs after matching for age and sex (area under the curve = 0.87, P < .001). Intraclass correlation coefficients revealed moderate-to-excellent degrees of inter- and intrareader agreement. CONCLUSIONS: MR imaging morphometric analysis can differentiate patients with olfactory dysfunction, with the olfactory bulb height having the highest diagnostic performance for detecting olfactory dysfunction irrespective of age.


Assuntos
Imageamento por Ressonância Magnética/métodos , Transtornos do Olfato/diagnóstico por imagem , Bulbo Olfatório/diagnóstico por imagem , Nervo Olfatório/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Adulto Jovem
11.
Phys Rev Lett ; 124(20): 207001, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32501078

RESUMO

By employing a series of experimental techniques, we provide clear evidence that CaPtAs represents a rare example of a noncentrosymmetric superconductor which simultaneously exhibits nodes in the superconducting gap and broken time-reversal symmetry (TRS) in its superconducting state (below T_{c}≈1.5 K). Unlike in fully gapped superconductors, the magnetic penetration depth λ(T) does not saturate at low temperatures, but instead it shows a T^{2} dependence, characteristic of gap nodes. Both the superfluid density and the electronic specific heat are best described by a two-gap model comprising of a nodeless gap and a gap with nodes, rather than by single-band models. At the same time, zero-field muon-spin relaxation spectra exhibit increased relaxation rates below the onset of superconductivity, implying that TRS is broken in the superconducting state of CaPtAs, hence indicating its unconventional nature. Our observations suggest CaPtAs to be a new remarkable material that links two apparently disparate classes, that of TRS-breaking correlated magnetic superconductors with nodal gaps and the weakly correlated noncentrosymmetric superconductors with broken TRS, normally exhibiting only a fully gapped behavior.

12.
J Laryngol Otol ; 134(5): 419-423, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32425141

RESUMO

OBJECTIVE: To assess the Framingham risk score as a prognostic tool for idiopathic sudden sensorineural hearing loss patients. METHODS: Medical records were reviewed for unilateral idiopathic sudden sensorineural hearing loss patients between January 2010 and October 2017. The 10-year risk of developing cardiovascular disease was calculated. Patients were subdivided into groups: group 1 - Framingham risk score of less than 10 per cent (n = 28); group 2 - score of 10 to less than 20 per cent (n = 6); and group 3 - score of 20 per cent or higher (n = 5). RESULTS: Initial pure tone average and Framingham risk score were not significantly associated (p = 0.32). Thirteen patients in group 1 recovered completely (46.4 per cent), but none in groups 2 and 3 showed complete recovery. Initial pure tone average and Framingham risk score were significantly associated in multivariable linear regression analysis (R2 = 0.36). The regression coefficient was 0.33 (p = 0.003) for initial pure tone average and -0.67 (p = 0.005) for Framingham risk score. CONCLUSION: Framingham risk score may be useful in predicting outcomes for idiopathic sudden sensorineural hearing loss patients, as those with a higher score showed poorer hearing recovery.


Assuntos
Perda Auditiva Neurossensorial/diagnóstico , Doença Aguda , Audiometria de Tons Puros , Doenças Cardiovasculares/diagnóstico , Feminino , Perda Auditiva Neurossensorial/etiologia , Perda Auditiva Neurossensorial/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Recuperação de Função Fisiológica/fisiologia , Medição de Risco/métodos
14.
AJNR Am J Neuroradiol ; 41(1): 155-159, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31806599

RESUMO

Glomangiopericytoma is a rare sinonasal mesenchymal tumor of borderline or low malignant potential. We reviewed the CT and MR imaging findings of head and neck glomangiopericytoma via a retrospective case series study and systematic review. Our study revealed that glomangiopericytoma is a well-defined lobulated avidly enhancing soft-tissue mass with erosive bony remodeling that is most commonly found in the sinonasal cavity. Typically, it is hyperintense on T2-weighted images with vascular signal voids, has a high mean ADC value, and a wash-in and washout pattern on dynamic contrast-enhanced MR imaging. Although the CT findings are nonspecific, typical MR imaging findings, including those on the ADC map and dynamic contrast-enhanced MR imaging, may be helpful for differentiating glomangiopericytomas from other hypervascular tumors in the head and neck.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Hemangiopericitoma/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Neoplasias de Cabeça e Pescoço/patologia , Hemangiopericitoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Seios Paranasais/diagnóstico por imagem , Seios Paranasais/patologia , Estudos Retrospectivos
15.
Curr Oncol ; 26(Suppl 1): S7-S15, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31819705

RESUMO

Background: The incorporation of novel biomarkers into therapy selection for patients with metastatic colorectal cancer (mcrc) has significantly improved outcomes. Optimal treatment planning now takes into account diverse characteristics of patients and their tumours to create personalized therapeutic plans. Discussion: This review is split into two sections. In the first section, we review the prognostic and predictive significance of expanded RAS mutation testing, BRAF mutations, ERBB2 (her2) amplification, microsatellite instability (msi) and deficient mismatch repair (dmmr) protein, NTRK fusions, PIK3CA mutations, and met amplifications. The therapeutic implication of each of those biomarkers for personalizing therapies for each patient with mcrc is discussed. In the second section, we touch on testing methods and considerations of relevance to clinicians when they interpret companion diagnostics meant to guide therapy selection. The advantages and pitfalls of various methods are evaluated, and we also look at the potential of liquid biopsies and circulating tumour dna (ctdna) to change the landscape of therapeutic choice and biologic understanding of the disease. Summary: Routine testing for extended RAS, BRAF, dmmr or high msi, and NTRK fusions is necessary to determine the best sequencing of chemotherapy and biologic agents for patients with mcrc. Although next-generation sequencing and ctdna are increasingly being adopted, other techniques such as immunohistochemistry retain their relevance in detection of her2 amplification, NTRK fusions, and dmmr.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Colorretais/complicações , Feminino , Humanos , Masculino , Metástase Neoplásica , Prognóstico
16.
BMC Fam Pract ; 20(1): 139, 2019 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-31630674

RESUMO

BACKGROUND: Postgraduate vocational training in family medicine (FM) is essential for physicians to build capacity and develop quality primary care. Inadequate standards in training and curriculum development can contribute to poor recruitment and retention of doctors in primary care. This study aimed to investigate: 1) the satisfaction level of doctors regarding vocational training in family medicine and associated demographics; and 2) the satisfaction level of doctors regarding their family medicine career and associated factors. METHOD: This is a cross sectional study of all family medicine physicians across all government-funded primary care clinics (GOPCs). The study questionnaire consisted of items from a standardized and validated physician survey named the Physician Worklife Survey (PWS) (Konrad et al., Med Care, 1999). We selected three scales (7 items) relating to global job satisfaction, global career satisfaction and global specialty (family medicine) satisfaction with additional items on training and demographics. All significant variables in bivariate analyses were further examined using stepwise logistic regression. RESULTS: Out of 424 eligible family medicine physicians, 368 physicians successfully completed the questionnaire. The response rate was 86.8%. Most participants were male (52.6%), were aged between 35 and 44 years (55.5%), were FM specialists (42.4%), graduated locally (86.2%), and had postgraduate qualifications. Eighty-two percent (82%) of participants were satisfied with their training. Having autonomy and protected time for training were associated with satisfaction with FM training. Satisfaction with family medicine as a career was correlated with physicians' satisfaction with their current job. Doctors who did not enroll in training (p < 0.001) and physicians who were older (p = 0.023) were significantly less satisfied. Stepwise multivariate regression showed that doctors who subjectively believed their training as "broad and in depth' had higher career satisfaction (p < 0.001). CONCLUSION: Overall, the satisfaction level of physicians on current family medicine training in Hong Kong was high. Having autonomy and protected time for training is associated with higher training satisfaction levels. Perceiving FM training as "broad and in-depth" is associated with higher family medicine career satisfaction.


Assuntos
Medicina de Família e Comunidade/educação , Satisfação no Emprego , Educação Vocacional , Adulto , Estudos Transversais , Feminino , Clínicos Gerais/educação , Clínicos Gerais/psicologia , Clínicos Gerais/estatística & dados numéricos , Hong Kong , Humanos , Masculino , Inquéritos e Questionários
17.
BMC Oral Health ; 19(1): 215, 2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533690

RESUMO

BACKGROUND: Dental caries is the most common chronic disease in the US and disproportionately affects racial/ethnic minorities. Caries is heritable, and though genetic heterogeneity exists between ancestries for a substantial portion of loci associated with complex disease, a genome-wide association study (GWAS) of caries specifically in African Americans has not been performed previously. METHODS: We performed exploratory GWAS of dental caries in 109 African American adults (age > 18) and 96 children (age 3-12) from the Center for Oral Health Research in Appalachia (COHRA1 cohort). Caries phenotypes (DMFS, DMFT, dft, and dfs indices) assessed by dental exams were tested for association with 5 million genotyped or imputed single nucleotide polymorphisms (SNPs), separately in the two age groups. The GWAS was performed using linear regression with adjustment for age, sex, and two principal components of ancestry. A maximum of 1 million adaptive permutations were run to determine empirical significance. RESULTS: No loci met the threshold for genome-wide significance, though some of the strongest signals were near genes previously implicated in caries such as antimicrobial peptide DEFB1 (rs2515501; p = 4.54 × 10- 6) and TUFT1 (rs11805632; p = 5.15 × 10- 6). Effect estimates of lead SNPs at suggestive loci were compared between African Americans and Caucasians (adults N = 918; children N = 983). Significant (p < 5 × 10- 8) genetic heterogeneity for caries risk was found between racial groups for 50% of the suggestive loci in children, and 12-18% of the suggestive loci in adults. CONCLUSIONS: The genetic heterogeneity results suggest that there may be differences in the contributions of genetic variants to caries across racial groups, and highlight the critical need for the inclusion of minorities in subsequent and larger genetic studies of caries in order to meet the goals of precision medicine and to reduce oral health disparities.


Assuntos
Cárie Dentária , Heterogeneidade Genética , Estudo de Associação Genômica Ampla , Adulto , Negro ou Afro-Americano , Animais , Criança , Feminino , Predisposição Genética para Doença , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , beta-Defensinas
18.
Curr Oncol ; 26(6): 404, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31896939

RESUMO

[This corrects the article on p. S7 in vol. 26, PMID: 31819705.].

19.
J Phys Condens Matter ; 30(31): 315803, 2018 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-29947614

RESUMO

We report the single-crystal synthesis and detailed investigations of the cage-type superconductor Sc5Ru6Sn18, using powder x-ray diffraction (XRD), magnetization, specific-heat and muon-spin relaxation (µSR) measurements. Sc5Ru6Sn18 crystallizes in a tetragonal structure (space group I41/acd) with lattice parameters a = 1.387(3) nm and c = 2.641(5) nm. Both DC and AC magnetization measurements prove the type-II superconductivity in Sc5Ru6Sn18 with T c ≈ 3.5(1) K, a lower critical field [Formula: see text] = 157(9) Oe and an upper critical field, [Formula: see text] = 26(1) kOe. The zero-field electronic specific-heat data are well fitted using a single-gap BCS model, with [Formula: see text] = 0.64(1) meV. The Sommerfeld constant γ varies linearly with the applied magnetic field, indicating s-wave superconductivity in Sc5Ru6Sn18. Specific-heat and transverse-field (TF) µSR measurements reveal that Sc5Ru6Sn18 is a superconductor with strong electron-phonon coupling, with TF-µSR also suggesting a single-gap s-wave character of the superconductivity. Furthermore, zero-field µSR measurements do not detect spontaneous magnetic fields below T c, hence implying that time-reversal symmetry is preserved in Sc5Ru6Sn18.

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