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1.
Phys Rev Lett ; 131(4): 046001, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37566829

RESUMO

Nuclear magnetic resonance measurements of the magnetic susceptibility of superfluid ^{3}He imbibed in anisotropic aerogel reveal anomalous behavior at low temperatures. Although the frequency shift clearly identifies a low-temperature phase as the B phase, the magnetic susceptibility does not display the expected decrease associated with the formation of the opposite-spin Cooper pairs. This susceptibility anomaly appears to be the predicted high-field behavior corresponding to the Ising-like magnetic character of surface Andreev bound states within the planar aerogel structures.

2.
Plant Dis ; 107(3): 616-619, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35852904

RESUMO

As a black shoot blight disease-causing agent, Erwinia pyrifoliae was first reported in 1995 in Korea. A total of 101 isolates of E. pyrifoliae were isolated from samples showing bacterial symptoms collected from apple and pear orchards between 2020 and 2021. These isolates were screened for streptomycin resistance, with one from an orchard in Gwangju showing resistance at 100 µg/ml streptomycin. This streptomycin-resistant E. pyrifoliae (EpSmR) isolate was identified via polymerase chain reaction amplification of the strA/strB gene and an internal region of the ribosomal rpsL gene containing codon 43. EpSmR has a point mutation that altered this codon from lysine (AAA) to threonine (ACA). The strA and strB genes were not identified in EpSmR. EpSmR showed a high resistance to streptomycin (>50,000 µg/ml). This is the first study reporting EpSmR, which emerged due to a mutation in codon 43 of the rpsL gene.


Assuntos
Erwinia , Pyrus , Estreptomicina/farmacologia , Erwinia/genética , Pyrus/microbiologia , República da Coreia
3.
QJM ; 115(12): 830-836, 2022 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-35866641

RESUMO

BACKGROUND: While progress is evident in gender and ethnic representation in the workplace, this disparity remains prevalent in academic positions. OBJECTIVES: We examined gender and Asian ethnic representation in editorial boards of cardiology journals. METHODS: A cross-sectional analysis was conducted using publicly available data on Cardiology and Cardiovascular medicine journals in the first quartile of the 2020 Scimago Journal & Country Rank indicator. The proportions of female and Asian editorial board members, associate editors and editors-in-chief were assessed. Subgroup analyses were conducted based on the journal's geographical origin, subspecialty and demographic of the editor-in-chief. RESULTS: Seventy-six cardiology journals, involving 8915 editorial board members, were included. Only 19.6% of editorial board members were female, 20.8% Asians and 4.0% Asian females. There were less female representation amongst editors-in-chief (9.9%) compared to associate editors (22.3%). European (18.1%) and North American-based journals (21.1%) had higher female representation compared to Asian-based journals (8.7%). There was lower Asian representation in European (18.1%) and North American-based journals (19.9%) compared to Asian-based journals (72.3%). Females were underrepresented in interventional (14.5%) journals, while Asians were underrepresented in general cardiology (18.3%) and heart failure (18.3%) journals. Journals led by female editors-in-chief had significantly higher female representation compared to male-led ones, while journals with Asian editors-in-chief had greater Asian representation compared to non-Asian led ones. CONCLUSION: This study highlights the female and Asian ethnic underrepresentation in academic roles in cardiology journal editorial boards. Further analysis is needed for other ethnicities, while the community pushes towards gender-balanced and ethnic diversity across editorial boards.


Assuntos
Asiático , Equidade de Gênero , Feminino , Humanos , Masculino , Estudos Transversais
4.
Ann Surg Oncol ; 29(5): 2773-2783, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35211857

RESUMO

BACKGROUND: The purpose of this article is to summarize the opinions of the surgical oncology leaders from the Global Forum of Cancer Surgeons (GFCS) about the global impact of COVID-19 pandemic on cancer surgery. METHODS: A panel session (virtual) was held at the annual Society of Surgical Oncology 2021 International Conference on Surgical Cancer Care to address the impact of COVID-19 on cancer surgery globally. Following the virtual meeting, a questionnaire was sent to all the leaders to gather additional opinions. The input obtained from all the leaders was collated and analyzed to understand how cancer surgeons from across the world adapted in real-time to the impact of COVID-19 pandemic. RESULTS: The surgical oncology leaders noted that the COVID-19 pandemic led to severe disruptions in surgical cancer care across all domains of clinical care, education, and research. Several new changes/protocols associated with increased costs were implemented to deliver safe care. Leaders also noted that preexisting disparities in care were exacerbated, and the pandemic had a detrimental effect on well-being and financial status. CONCLUSIONS: The COVID-19 pandemic has led to severe disruptions in surgical cancer care globally. Leaders of the GFCS opined that new strategies need to be implemented to prepare for any future catastrophic events based on the lessons learned from the current events. The GFCS will embark on developing such a roadmap to ensure that surgical cancer care is preserved in the future regardless of any catastrophic global events.


Assuntos
COVID-19 , Neoplasias , Cirurgiões , Oncologia Cirúrgica , COVID-19/epidemiologia , Humanos , Neoplasias/cirurgia , Pandemias
5.
Science ; 375(6581): 653-657, 2022 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-35143321

RESUMO

Piezoelectrics are materials that linearly deform in response to an applied electric field. As a fundamental prerequisite, piezoelectric materials must have a noncentrosymmetric crystal structure. For more than a century, this has remained a major obstacle for finding piezoelectric materials. We circumvented this limitation by breaking the crystallographic symmetry and inducing large and sustainable piezoelectric effects in centrosymmetric materials by the electric field-induced rearrangement of oxygen vacancies. Our results show the generation of extraordinarily large piezoelectric responses [with piezoelectric strain coefficients (d33) of ~200,000 picometers per volt at millihertz frequencies] in cubic fluorite gadolinium-doped CeO2-x films, which are two orders of magnitude larger than the responses observed in the presently best-known lead-based piezoelectric relaxor-ferroelectric oxide at kilohertz frequencies. These findings provide opportunities to design piezoelectric materials from environmentally friendly centrosymmetric ones.

6.
Int J Obstet Anesth ; 49: 103246, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35012809

RESUMO

BACKGROUND: The optimal fluid strategy to prevent maternal hypotension during caesarean delivery remains unclear. This study aim was to compare the incidence of post-spinal anaesthesia hypotension in women receiving either colloid or crystalloid coload in the setting of prophylactic phenylephrine infusion during caesarean delivery. METHODS: Healthy mothers undergoing elective caesarean delivery under spinal anaesthesia were randomised to receive a rapid intravenous coload with 6% hydroxyethyl starch 130/0.4 10 mL/kg (colloid group) or balanced crystalloid solution (Plasma Solution A) 10 mL/kg (crystalloid group) during spinal anaesthesia. All women had a prophylactic phenylephrine infusion initiated at 25 µg/min immediately after the subarachnoid block and titrated to systolic blood pressure using a standardised protocol. The primary outcome was the incidence of hypotension (systolic blood pressure <80% of baseline) until delivery. RESULTS: The incidence of hypotension was 50% in the colloid group and 62% in the crystalloid group (absolute difference, -12% [95% CI -33% to 9%]; relative risk, 0.8 [95% CI 0.56 to 1.14]; P=0.314). No significant difference between groups was found in the number of hypotensive episodes (median 0.5 [IQR 0 to 1] vs 1 [0 to 2], P=0.132) or phenylephrine dose (675 [IQR 425 to 975] µg vs 750 [625 to 950] µg, P=0.109). The incidence of severe hypotension, symptomatic hypotension, bradycardia, nausea, and the neonatal outcomes were not significantly different. CONCLUSIONS: This study found no benefit of colloid coload compared with crystalloid coload for preventing maternal hypotension in the presence of prophylactic phenylephrine infusion during caesarean delivery.


Assuntos
Anestesia Obstétrica , Raquianestesia , Hipotensão , Anestesia Obstétrica/efeitos adversos , Anestesia Obstétrica/métodos , Raquianestesia/efeitos adversos , Raquianestesia/métodos , Cesárea/métodos , Coloides/uso terapêutico , Soluções Cristaloides , Método Duplo-Cego , Feminino , Humanos , Hipotensão/etiologia , Recém-Nascido , Fenilefrina/uso terapêutico , Gravidez , Vasoconstritores/uso terapêutico
7.
Br J Surg ; 108(9): 1043-1049, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34487147

RESUMO

BACKGROUND: There remain concerns about the safety and functional benefit of laparoscopic pylorus-preserving gastrectomy (LPPG) compared with laparoscopic distal gastrectomy (LDG). This study evaluated short-term outcomes of a randomized clinical trial (RCT) comparing LPPG with LDG for gastric cancer. METHODS: The Korean Laparoendoscopic Gastrointestinal Surgery Study (KLASS)-04 trial was an investigator-initiated, open-label, parallel-assigned, superiority, multicentre RCT in Korea. Patients with cT1N0M0 cancer located in the middle third of the stomach at least 5 cm from the pylorus were randomized to undergo LPPG or LDG. Participants, care givers and those assessing the outcomes were not blinded to group assignment. Outcomes were 30-day postoperative morbidity rate and death at 90 days. RESULTS: Some 256 patients from nine institutions were randomized (LPPG 129 patients, LDG 127 patients) between July 2015 and July 2017 and outcomes for 253 patients were analysed. Postoperative complications within 30 days were seen in 19.3 and 15.5 per cent in the LPPG and LDG groups respectively (P = 0·419). Postoperative pyloric stenosis was observed in nine (7.2 per cent) and two (1·5 per cent) patients in the LPPG and LDG groups (P = 0·026) respectively. In multivariable analysis higher BMI was a risk factor for postoperative complications (odds ratio 1·17, 95 per cent c.i. 1·04 to 1·32; P = 0·011). Death at 90 days was zero in both groups. CONCLUSION: Postoperative complications and mortality was comparable in patients undergoing LPPG and LDG. Registration number: NCT02595086 (http://www.clinicaltrials.gov).


Assuntos
Gastrectomia/métodos , Laparoscopia/métodos , Estadiamento de Neoplasias/métodos , Piloro/cirurgia , Neoplasias Gástricas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Gástricas/diagnóstico , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
8.
Front Chem ; 9: 733383, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568281

RESUMO

CoPt and CoPtP thin films were synthesized using direct current (DC) aqueous electrodeposition from weak alkaline solutions. The basic plating solutions of binary CoPt thin films consisted of cobalt pyrophosphate [Co2P2O7] and chloroplatinic acid [H2PtCl6]. Various amounts of sodium hypophosphite [NaH2PO2] was added to deposit ternary CoPtP thin films. The film composition was adjusted by varying the several electrodeposition parameters including electrolyte composition, solution pH, and current density and correlated to their microstructure and magnetic property (i.e. coercivity and squareness). For the binary CoPt thin films, the maximum coercivities [in-plane coercivity (Hc,//) = ∼1,600 Oe, and perpendicular coercivity (Hc,⊥) = ∼2,500 Oe] were obtained from electrolytes containing 0.01 M H2PtCl6 + 0.04 M Co2P2O7 at current density (CD) of 7.5 mA cm-2. In the case of ternary CoPtP electrodeposits, the maximum coercivities (Hc,// = ∼2,600 Oe, and Hc,⊥ = ∼3,800 Oe) were achieved from baths containing 0.015 M H2PtCl6, 0.07 M Co2P2O7, 0.8 M NaH2PO2 at CD of 7.5 mA cm- 2 and solution pH 9. It was suggested that microstructure and magnetic properties are affected not only by the type of substrate but also by chemical compositions and electrodeposition conditions.

9.
medRxiv ; 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-33619501

RESUMO

SARS-CoV-2 enters host cells by binding angiotensin-converting enzyme 2 (ACE2). Through a genome-wide association study, we show that a rare variant (MAF = 0.3%, odds ratio 0.60, P=4.5×10-13) that down-regulates ACE2 expression reduces risk of COVID-19 disease, providing human genetics support for the hypothesis that ACE2 levels influence COVID-19 risk. Further, we show that common genetic variants define a risk score that predicts severe disease among COVID-19 cases.

11.
Eur Rev Med Pharmacol Sci ; 25(1): 273-286, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33506916

RESUMO

OBJECTIVE: Although many previous meta-analyses of epidemiological studies have demonstrated a relationship between body mass index (BMI) and mortality, inconsistent findings among cardiovascular disease patients have been observed. Thus, we performed an umbrella review to understand the strength of evidence and validity of claimed associations between BMI and mortality in patients with cardiovascular diseases. MATERIALS AND METHODS: We comprehensively re-analyzed the data of meta-analyses of observational studies and randomized controlled trials on associations between BMI and mortality among patients with cardiovascular diseases. We also assessed the strength of evidence of the re-analyzed outcomes, which were determined from the criteria including statistical significance of the p-value of random-effects, as well as fixed-effects meta-analyses, small-study effects, between-study heterogeneity, and a 95% prediction interval. RESULTS: We ran comprehensive re-analysis of the data from the 21 selected studies, which contained a total of 108 meta-analyses; 23 were graded as convincing evidence and 12 were suggestive, 42 were weak, and 23 were non-significant. CONCLUSIONS: Underweight increased mortality in acute coronary syndrome (ACS), heart failure, and after therapeutic intervention for patients with cardiovascular diseases. Overweight, on the other hand decreased mortality in patient's ACS, atrial fibrillation, and heart failure with convincing evidence.


Assuntos
Índice de Massa Corporal , Doenças Cardiovasculares/mortalidade , Humanos , Metanálise como Assunto , Estudos Observacionais como Assunto , Ensaios Clínicos Controlados Aleatórios como Assunto
12.
J Endocrinol Invest ; 44(5): 1065-1073, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32876925

RESUMO

OBJECTIVE: We compared demographic and clinic-pathological variables related to the number of surgeries for thyroid conditions or for cancer, morbidity, and fine needle aspiration (FNA) practices among Covid19 pandemic phases I, II, III and the same seasonal periods in 2019. METHODS: The prospective database of the Division of Thyroid Surgery, China-Japan Union Hospital of Jilin University, Changchun, China was used for this study. Covid19 emergency levels were stratified according to the World Health Organization: phase I (January 25-February 25, 2020), phase II (February 26-March 19), phase III (March 20-April 20). RESULTS: There were fewer outpatient FNAs and surgeries in 2020 than in 2019. There were no thyroid surgeries during phase I. There were also fewer surgeries for cancer with a significant reduction of advanced stage cancer treatments, mainly stage T1b N1a in phase II and T3bN1b in phase III. Operative times and postoperative stays were significantly shorter during the pandemic compared to our institutional baseline. In phase III, vocal cord paralysis (VCP) increased to 4.3% of our baseline numbers (P = 0.001). There were no cases of Covid19-related complications during the perioperative period. No patients required re-admission to the hospital. CONCLUSION: The Covid19 outbreak reduced thyroid surgery patient volumes. The decrease of Covid19 emergency plans contributed to unexpected outcomes (reduction of early stage cancer treatment, decreased operative times and hospital stays, increased VCP rate).


Assuntos
COVID-19 , Pandemias , Doenças da Glândula Tireoide/cirurgia , Glândula Tireoide/cirurgia , Adulto , Idoso , Biópsia por Agulha Fina/estatística & dados numéricos , China , Feminino , Humanos , Irã (Geográfico) , Itália , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Duração da Cirurgia , Complicações Pós-Operatórias/epidemiologia , Traumatismos do Nervo Laríngeo Recorrente/epidemiologia , República da Coreia , Doenças da Glândula Tireoide/patologia , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia/efeitos adversos , Paralisia das Pregas Vocais/epidemiologia , Paralisia das Pregas Vocais/etiologia
13.
J Eur Acad Dermatol Venereol ; 35(2): 380-386, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32562580

RESUMO

BACKGROUND: Hutchinson's nail sign (HS) is among the diagnostic criteria for subungual melanoma (SUM). However, there is minimal evidence supporting the overall clinical significance of HS in SUM. OBJECTIVES: To identify clinicopathological features of SUM according to the extent of HS. METHODS: Retrospective cohort study was performed with consecutive SUM patients at a single centre from January 2006 to December 2017. The extent of HS was defined by the number of affected nail folds (range 0-4). Comparison groups were organized as follows: patients with HS (affecting ≥1 nail folds) vs. without HS; patients with HS affecting ≥2 nail folds vs. HS affecting <2 nail folds; patients with HS affecting ≥3 nail folds vs. HS affecting <3 nail folds. Clinicopathological characteristics of SUM were compared between the groups. RESULTS: Sixty-one SUM patients were included. Forty-six (75.4%) exhibited HS; 22 (47.8%) on a toe and 24 (52.2%) on a finger. In multivariate analysis, nail destruction [hazard ratio (HR), 10.00; 95% confidence interval (CI), 2.61-38.30; P = 0.001] was significantly associated with the presence of HS and amputation was significantly associated with HS affecting ≥2 nail folds (HR, 4.75; 95% CI, 1.36-16.61; P = 0.015). High T stage (HR, 1.85; 95% CI, 1.20-2.85; P = 0.005, Fig. 2) was significantly associated with HS appearing in ≥3 nail folds. CONCLUSION: Besides its value of detecting SUM, HS provides useful clinical information. The number of nail folds exhibiting HS could be a useful clinical clue for planning therapeutic strategies for SUM.


Assuntos
Melanoma , Doenças da Unha , Neoplasias Cutâneas , Humanos , Melanoma/diagnóstico , Unhas , Estudos Retrospectivos , Neoplasias Cutâneas/diagnóstico
14.
s.l; Harvard Business School; 2021.
Não convencional em Inglês | ODS | ID: biblio-1344806

RESUMO

As an organization's environmental impact has become a central societal consideration, thereby affecting industry and organizational competitiveness, interest in measuring and analyzing environmental impact has increased. We develop a methodology to derive comparable and scalable monetized environmental impact estimates by applying characterization pathways and monetization factors to organization level environmental outputs, including carbon emissions, water use, and other emission types. The median environmental impact as a percentage of an organization's sales (operating income), referred to as environmental intensity, is 2% (22%) suggesting a significant level of 'hidden liabilities' and potential for value erosion if environmental impacts are priced. About 60% of the variation in environmental intensity is driven by industry membership, while the rest can be attributed to firm specific factors or to country and more granular industry classifications. Environmental intensity exhibits moderate correlation with various environmental ratings across firms and industries and no correlation across firms within industries. Firms with higher environmental intensity exhibit lower corporate market valuation, consistent with investors viewing environmental impacts as financially material and pricing them in some but not all industries. We document the dynamic materiality of environmental intensity, where the relation between environmental intensity and corporation valuation has become stronger in recent years.(AU)


Assuntos
Corporações Profissionais/economia , Dióxido de Carbono/efeitos adversos , Meio Ambiente , Poluição Ambiental/efeitos adversos , Indústrias
15.
Benef Microbes ; 11(4): 361-373, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32755263

RESUMO

Excessive body fat and the related dysmetabolic diseases affect both developed and developing countries. The aim of this study was to investigate the beneficial role of a bacterial culture supernatant (hereafter: BS) of Lactobacillus and Bifidobacterium and their potential mechanisms of action on white-fat browning and lipolysis. For selection of four candidates among 55 Lactic acid producing bacteria (LAB) from human infant faeces, we evaluated by Oil Red O staining and Ucp1 mRNA quantitation in 3T3-L1 preadipocytes. The expression of browning and lipolysis markers was examined along with in vitro assays. The possible mechanism was revealed by molecular and biological experiments including inhibitor and small interfering RNA (siRNA) assays. In a mouse model, physiological, histological, and biochemical parameters and expression of some thermogenesis-related genes were compared among six experimental groups fed a high-fat diet and one normal-diet control group. The results allow us to speculate that BS treatment promotes browning and lipolysis both in vitro and in vivo. Moreover, the BS may activate thermogenic programs via a mechanism involving PKA-CREB signaling in 3T3-L1 cells. According to our data, we can propose that two LAB strains, Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508, may be good candidates for a dietary supplement against obesity and metabolic diseases; however, further research is required for the development as dietary supplements or drugs.


Assuntos
Bifidobacterium longum/metabolismo , Lacticaseibacillus rhamnosus/metabolismo , Obesidade/terapia , Termogênese/efeitos dos fármacos , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Diferenciação Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/metabolismo , Meios de Cultivo Condicionados/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Dieta Hiperlipídica/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Lipólise/efeitos dos fármacos , Lipólise/genética , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Obesidade/etiologia , Obesidade/genética , Obesidade/metabolismo , Oxirredução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Termogênese/genética
16.
J Dairy Sci ; 103(9): 7752-7760, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32622594

RESUMO

Osteoporosis is a systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue, with a consequent increase in bone fragility and fracture susceptibility. In an aged society with increased life expectancy, the incidence rate of osteoporosis is also rapidly increasing. Inadequate nutrition may negatively influence bone metabolism. Recently, many studies have investigated the functionality of milk-derived exosomes, which play important roles in cell-to-cell communication. However, there are few reports of how milk-derived exosomes influence osteoblast proliferation and differentiation. Here, we determined whether bovine colostrum-derived exosomes promote anti-osteoporosis in vitro and in vivo. Tartrate-resistant acid phosphatase-stained cells were significantly inhibited in Raw264.7 cells treated with exosomes, indicating reduced osteoclast differentiation. We induced osteoporosis in mice using glucocorticoid pellets after orally administering exosomes for 2 mo. Interestingly, the bone mineral density of exosome-fed mouse groups was significantly improved compared with the glucocorticoid-induced osteoporosis group without exosome treatment. In addition, Lactobacillus were decreased in the gut microbiota community of osteoporosis-induced mice, but the gut microbiota community composition was effectively restored by exosome intake. Taken together, we propose that exosomes isolated from bovine colostrum could be a potential candidate for osteoporosis prevention, bone remodeling improvement, and inhibition of bone resorption. To our knowledge, this is the first time that a protective effect of milk exosomes against osteoporosis has been demonstrated in vivo. Our results strongly suggest that bovine colostrum exosomes might be used as a prophylaxis to prevent the onset of osteoporosis. Indeed, our results offer promising alternative strategies in the nutritional management of age-related bone complications.


Assuntos
Exossomos , Leite/química , Osteoporose/dietoterapia , Animais , Densidade Óssea , Osso e Ossos/efeitos dos fármacos , Bovinos , Modelos Animais de Doenças , Exossomos/metabolismo , Camundongos , Osteoporose/metabolismo , Osteoporose/veterinária
17.
Nat Commun ; 11(1): 3650, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32686663

RESUMO

Complex oxides show extreme sensitivity to structural distortions and defects, and the intricate balance of competing interactions which emerge at atomically defined interfaces may give rise to unexpected physics. In the interfaces of non-magnetic complex oxides, one of the most intriguing properties is the emergence of magnetism which is sensitive to chemical defects. Particularly, it is unclear which defects are responsible for the emergent magnetic interfaces. Here, we show direct and clear experimental evidence, supported by theoretical explanation, that the B-site cation stoichiometry is crucial for the creation and control of magnetism at the interface between non-magnetic ABO3-perovskite oxides, LaAlO3 and SrTiO3. We find that consecutive defect formation, driven by atomic charge compensation, establishes the formation of robust perpendicular magnetic moments at the interface. Our observations propose a route to tune these emerging magnetoelectric structures, which are strongly coupled at the polar-nonpolar complex oxide interfaces.

18.
Clin Radiol ; 75(9): 714.e15-714.e20, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32591231

RESUMO

AIM: To differentiate dural arteriovenous fistula (DAVF) from reflux venous flow (RVF) by assessment of asymmetric enlargement of external carotid artery (ECA) branches on three-dimensional (3D) time-of-flight magnetic resonance angiography (TOF-MRA). MATERIALS AND METHODS: Nineteen patients with DAVF and 27 patients with RVF were included from September 2007 to April 2019. The locations of DAVF were the cavernous (n=9) and sigmoid-transverse (n=6) sinuses, and the jugular (n=3) and sphenoparietal (n=1) veins. Two radiologists visually assessed asymmetric enlargement of the ascending pharyngeal artery (ASP), middle meningeal artery (MMA), accessory meningeal artery (AMA), artery of the foramen rotundum, and occipital artery. MMA size was also measured quantitatively. RESULTS: More frequent asymmetric enlargement of the ASP and MMA were seen in DAVF than in RVF (17 of 19 versus 3 of 27 for ASP; 16 of 19 versus 1 of 27 for MMA, p<0.01). The AMA, artery of the foramen rotundum, and occipital arteries were not visualised in RVF patients. The ipsilateral MMA size was significantly larger in DAVF than in RVF (2.14 versus 0.64 mm2, p< 0.01). The diagnostic performance of ipsilateral MMA size for DAVF was good, with an area under the receiver operating characteristic curve of 0.89, with a sensitivity of 84.2% and a specificity of 81.5% at a cut-off of 1.08 mm2. CONCLUSIONS: DAVF showed significantly larger ECA branches than RVF on 3D TOF-MRA. Therefore, thorough evaluation of ECA branches could help to differentiate DAVF from RVF.


Assuntos
Artéria Carótida Externa/diagnóstico por imagem , Malformações Vasculares do Sistema Nervoso Central/diagnóstico , Angiografia Cerebral/métodos , Imageamento Tridimensional/métodos , Angiografia por Ressonância Magnética/métodos , Fluxo Sanguíneo Regional/fisiologia , Idoso , Idoso de 80 Anos ou mais , Artéria Carótida Externa/fisiopatologia , Malformações Vasculares do Sistema Nervoso Central/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
20.
Rev Sci Instrum ; 91(2): 025103, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32113430

RESUMO

This paper reports on the first successful nonlinear ultrasonic measurement on highly irradiated specimens in a hot cell environment. The specimens are ANSI 304 stainless steel specimens for which the microstructure characterization and ultrasonic velocity measurement have been previously conducted. The critical part of this research is the development of an automatic fixture device that can facilitate repeatable loading and unloading to place the contact ultrasonic transducers on and off of the specimen. The key step to achieve high measurement repeatability is a careful adjustment of the support-spring constants such that the contact force at the interface between the transducer face and specimen surface is as uniform and constant as possible. The longitudinal ultrasonic velocities, which are obtained as a by-product of the nonlinear ultrasonic measurements, show a level of random variation in terms of (max-min)/average (%) below 0.2%, and the velocity distributions and magnitudes are in good agreement with those from the previous work. The ultrasonic nonlinearity parameters show the level of random variation below 4.7%, which is extremely low, considering that the measurements are conducted in a hot cell environment. The nonlinearity parameters also show a strong dependence on the measurement location in a particular specimen with respect to the radiation source, demonstrating a possible inhomogeneous microstructure evolution in these 12.7 mm thick specimens. This research demonstrates the feasibility of making nonlinear ultrasonic measurement on highly radioactive materials and/or in a highly radioactive environment using the device and procedure developed.

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