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1.
Malays J Pathol ; 46(1): 91-94, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38682848

RESUMO

Intraplacental choriocarcinoma is a rare tumour, with approximately 62 reported cases. It may manifest as a spectrum of disease ranging from an incidental lesion diagnosed on routine placental examination to disseminated maternal and/or neonatal disease. In this case series, we presented two rare cases of intraplacental choriocarcinoma with extremely varied clinical presentations. The extremely varied clinical presentations of both patients described in the case series complicated the process of arriving at the diagnosis. In both cases, subsequent investigations showed no maternal or neonatal metastasis, and maternal serum beta-hCG levels downtrended with conservative management. We aim to highlight the importance of performing a detailed physical examination and evaluation of the patient and multidisciplinary management with oncology opinion. A detailed examination of the placenta should also be considered when faced with obstetric complications so that early diagnosis and the required management can be executed in a prompt fashion.


Assuntos
Coriocarcinoma , Centros de Atenção Terciária , Humanos , Feminino , Gravidez , Coriocarcinoma/diagnóstico , Coriocarcinoma/patologia , Adulto , Neoplasias Uterinas/patologia , Neoplasias Uterinas/diagnóstico , Complicações Neoplásicas na Gravidez/patologia , Complicações Neoplásicas na Gravidez/diagnóstico
2.
J Magn Reson Imaging ; 49(7): e14-e25, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30145852

RESUMO

There is increasing scrutiny from healthcare organizations towards the utility and associated costs of imaging. MRI has traditionally been used as a high-end modality, and although shown extremely important for many types of clinical scenarios, it has been suggested as too expensive by some. This editorial will try and explain how value should be addressed and gives some insights and practical examples of how value of MRI can be increased. It requires a global effort to increase accessibility, value for money, and impact on patient management. We hope this editorial sheds some light and gives some indications of where the field may wish to address some of its research to proactively demonstrate the value of MRI. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;49:e14-e25.


Assuntos
Imageamento por Ressonância Magnética/economia , Abdome/diagnóstico por imagem , Idoso , Mama/diagnóstico por imagem , Meios de Contraste , Feminino , Geografia , Custos de Cuidados de Saúde , Humanos , Processamento de Imagem Assistida por Computador , Fígado/diagnóstico por imagem , Imageamento por Ressonância Magnética/normas , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/diagnóstico por imagem , Próstata/diagnóstico por imagem , Embolia Pulmonar/diagnóstico por imagem , Mecanismo de Reembolso , Projetos de Pesquisa , Adulto Jovem
3.
Neuroradiology ; 61(11): 1281-1290, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31292692

RESUMO

PURPOSE: Adult-onset neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder described mainly in the Japanese population, with characteristic DWI abnormalities at the junction between gray and white matter. We identify possible cases of NIID in the picture archive and communication system (PACS) of a tertiary neurological referral hospital in Singapore and describe their radiological features. METHODS: The neuroradiology imaging database was reviewed using keyword search of radiological reports to identify patients who had "subcortical U fibre" abnormalities on DWI. MRI were retrospectively reviewed, and those fulfilling inclusion criteria were invited for skin biopsy to detect nuclear inclusions by light and electron microscopy. RESULTS: Twelve Chinese patients (nine female; median age 70.5 years) were enrolled. Seven patients were being assessed for dementia and five for other neurological indications. In all patients, DWI showed distinctive subcortical high signal with increased average apparent diffusion coefficient (ADC), involving frontal, parietal, and temporal more than occipital lobes; the corpus callosum and external capsule were affected in some patients. On T2-weighted images, cerebral and cerebellar atrophy and white matter hyperintensity of Fazekas grade 2 and above were seen in all patients. Three patients underwent skin biopsy; all were positive for intranuclear hyaline inclusion bodies on either p62 staining or electron microscopy, which are pathognomonic for NIID. CONCLUSION: Previously undiagnosed patients with NIID can be identified by searching for abnormalities at the junction between gray and white matter on DWI in PACS and subsequently confirmed by skin biopsy. Radiologists should recognize the distinctive neuroimaging pattern of this dementing disease.


Assuntos
Imagem de Difusão por Ressonância Magnética , Doenças Neurodegenerativas/diagnóstico por imagem , Idoso , Feminino , Humanos , Corpos de Inclusão Intranuclear , Masculino , Pessoa de Meia-Idade , Doenças Neurodegenerativas/epidemiologia , Estudos Retrospectivos , Singapura/epidemiologia
4.
Lupus ; 27(7): 1150-1158, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29631512

RESUMO

Background There are limited studies documenting infection epidemiology in lupus nephritis (LN) patients. We aimed to study infection incidences and risk characteristics and ascertain possible predictors of infective outcomes in a multiethnic Asian population. Methods This retrospective study from 2006 to 2012 included newly diagnosed LN patients. We collected admissions, immunosuppression, and infection data until end-stage renal failure, death, last follow-up, or the year 2015. The infection incidence rates were evaluated and a generalized linear latent and mixed models (GLLAMM) analysis was carried out to evaluate potential predictors of infection. Results Our cohort of 101 patients consisted of mainly Chinese (75.2%), females (78.2%), and a median age of 38 years (IQR 26-49). The median time of follow-up was 72.8 months (IQR 49.5-94.0). Six out of 14 patient deaths were infection related. Seventy-eight out of 200 admissions, with a total of 102 episodes of infection, occurred in 46 patients. The incidence of infection rates leading to admissions was 10.3 per 100 person-years and the incidence of infection episodes rates was 17.6 per 100 person-years. Cytomegalovirus (CMV) was the most common organism identified. Univariate GLLAMM analysis showed Malay compared to Chinese ethnicity (HR 2.833 (95% CI 1.088-7.373)), use of oral cyclophosphamide (HR 6.618 (95% CI 1.015-43.154)) and rituximab (HR 3.967 (95% CI 1.157-13.603)) as predictors of infection-related admissions. Malay ethnicity and rituximab remained significant in the multivariate GLLAMM analysis. Conclusions Our study highlights substantial infection incidences in patients with LN and its contribution to deaths.


Assuntos
Infecções por Citomegalovirus/etiologia , Nefrite Lúpica/complicações , Adulto , Proteína C-Reativa/análise , Calcitonina/sangue , Ciclofosfamida/efeitos adversos , Feminino , Hospitalização , Humanos , Nefrite Lúpica/sangue , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Rituximab/efeitos adversos
5.
Acta Psychiatr Scand ; 137(4): 306-315, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29453789

RESUMO

OBJECTIVES: Religiosity is often associated with better health outcomes. The aim of the study was to examine associations between psychotic experiences (PEs) and religiosity in a large, cross-national sample. METHODS: A total of 25 542 adult respondents across 18 countries from the WHO World Mental Health Surveys were assessed for PEs, religious affiliation and indices of religiosity, DSM-IV mental disorders and general medical conditions. Logistic regression models were used to estimate the association between PEs and religiosity with various adjustments. RESULTS: Of 25 542 included respondents, 85.6% (SE = 0.3) (n = 21 860) respondents reported having a religious affiliation. Overall, there was no association between religious affiliation status and PEs. Within the subgroup having a religious affiliation, four of five indices of religiosity were significantly associated with increased odds of PEs (odds ratios ranged from 1.3 to 1.9). The findings persisted after adjustments for mental disorders and/or general medical conditions, as well as religious denomination type. There was a significant association between increased religiosity and reporting more types of PEs. CONCLUSIONS: Among individuals with religious affiliations, those who reported more religiosity on four of five indices had increased odds of PEs. Focussed and more qualitative research will be required to unravel the interrelationship between religiosity and PEs.


Assuntos
Saúde Global/estatística & dados numéricos , Saúde Mental/estatística & dados numéricos , Transtornos Psicóticos/epidemiologia , Religião , Adulto , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Organização Mundial da Saúde
6.
Med J Malaysia ; 73(2): 114-115, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29703877

RESUMO

Schwannoma of cervical sympathetic chain is a rare cause of neck swelling. We report a 73- year-old male presented with anterior neck triangle swelling mimicking a carotid body tumour. Surgical excision was done, and the histopathological examination reported as ancient schwannoma. We would like to discuss the important differential diagnoses and highlight the possibility of an ancient schwannoma of cervical sympathetic chain masquerading as carotid body tumour. Also, to emphasise the importance of imaging for pre-operative planning and counselling.


Assuntos
Tumor do Corpo Carotídeo/diagnóstico , Gânglios Simpáticos , Neoplasias de Cabeça e Pescoço/diagnóstico , Neurilemoma/diagnóstico , Idoso , Diagnóstico Diferencial , Gânglios Simpáticos/cirurgia , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Masculino , Neurilemoma/cirurgia
7.
Psychol Med ; 47(10): 1744-1760, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28222820

RESUMO

BACKGROUND: Although specific phobia is highly prevalent, associated with impairment, and an important risk factor for the development of other mental disorders, cross-national epidemiological data are scarce, especially from low- and middle-income countries. This paper presents epidemiological data from 22 low-, lower-middle-, upper-middle- and high-income countries. METHOD: Data came from 25 representative population-based surveys conducted in 22 countries (2001-2011) as part of the World Health Organization World Mental Health Surveys initiative (n = 124 902). The presence of specific phobia as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition was evaluated using the World Health Organization Composite International Diagnostic Interview. RESULTS: The cross-national lifetime and 12-month prevalence rates of specific phobia were, respectively, 7.4% and 5.5%, being higher in females (9.8 and 7.7%) than in males (4.9% and 3.3%) and higher in high- and higher-middle-income countries than in low-/lower-middle-income countries. The median age of onset was young (8 years). Of the 12-month patients, 18.7% reported severe role impairment (13.3-21.9% across income groups) and 23.1% reported any treatment (9.6-30.1% across income groups). Lifetime co-morbidity was observed in 60.5% of those with lifetime specific phobia, with the onset of specific phobia preceding the other disorder in most cases (72.6%). Interestingly, rates of impairment, treatment use and co-morbidity increased with the number of fear subtypes. CONCLUSIONS: Specific phobia is common and associated with impairment in a considerable percentage of cases. Importantly, specific phobia often precedes the onset of other mental disorders, making it a possible early-life indicator of psychopathology vulnerability.


Assuntos
Comorbidade , Emprego/estatística & dados numéricos , Saúde Global/estatística & dados numéricos , Saúde Mental/estatística & dados numéricos , Transtornos Fóbicos/epidemiologia , Fatores Socioeconômicos , Adolescente , Adulto , Idade de Início , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores Sexuais , Organização Mundial da Saúde , Adulto Jovem
8.
Psychol Med ; 47(13): 2260-2274, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28385165

RESUMO

BACKGROUND: Traumatic events are common globally; however, comprehensive population-based cross-national data on the epidemiology of posttraumatic stress disorder (PTSD), the paradigmatic trauma-related mental disorder, are lacking. METHODS: Data were analyzed from 26 population surveys in the World Health Organization World Mental Health Surveys. A total of 71 083 respondents ages 18+ participated. The Composite International Diagnostic Interview assessed exposure to traumatic events as well as 30-day, 12-month, and lifetime PTSD. Respondents were also assessed for treatment in the 12 months preceding the survey. Age of onset distributions were examined by country income level. Associations of PTSD were examined with country income, world region, and respondent demographics. RESULTS: The cross-national lifetime prevalence of PTSD was 3.9% in the total sample and 5.6% among the trauma exposed. Half of respondents with PTSD reported persistent symptoms. Treatment seeking in high-income countries (53.5%) was roughly double that in low-lower middle income (22.8%) and upper-middle income (28.7%) countries. Social disadvantage, including younger age, female sex, being unmarried, being less educated, having lower household income, and being unemployed, was associated with increased risk of lifetime PTSD among the trauma exposed. CONCLUSIONS: PTSD is prevalent cross-nationally, with half of all global cases being persistent. Only half of those with severe PTSD report receiving any treatment and only a minority receive specialty mental health care. Striking disparities in PTSD treatment exist by country income level. Increasing access to effective treatment, especially in low- and middle-income countries, remains critical for reducing the population burden of PTSD.


Assuntos
Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/estatística & dados numéricos , Saúde Global/estatística & dados numéricos , Disparidades em Assistência à Saúde/estatística & dados numéricos , Serviços de Saúde Mental/estatística & dados numéricos , Transtornos de Estresse Pós-Traumáticos/epidemiologia , Transtornos de Estresse Pós-Traumáticos/terapia , Populações Vulneráveis/estatística & dados numéricos , Adolescente , Adulto , Idade de Início , Idoso , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Organização Mundial da Saúde , Adulto Jovem
9.
Psychol Med ; 47(7): 1230-1245, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28065209

RESUMO

BACKGROUND: Although there is robust evidence linking childhood adversities (CAs) and an increased risk for psychotic experiences (PEs), little is known about whether these associations vary across the life-course and whether mental disorders that emerge prior to PEs explain these associations. METHOD: We assessed CAs, PEs and DSM-IV mental disorders in 23 998 adults in the WHO World Mental Health Surveys. Discrete-time survival analysis was used to investigate the associations between CAs and PEs, and the influence of mental disorders on these associations using multivariate logistic models. RESULTS: Exposure to CAs was common, and those who experienced any CAs had increased odds of later PEs [odds ratio (OR) 2.3, 95% confidence interval (CI) 1.9-2.6]. CAs reflecting maladaptive family functioning (MFF), including abuse, neglect, and parent maladjustment, exhibited the strongest associations with PE onset in all life-course stages. Sexual abuse exhibited a strong association with PE onset during childhood (OR 8.5, 95% CI 3.6-20.2), whereas Other CA types were associated with PE onset in adolescence. Associations of other CAs with PEs disappeared in adolescence after adjustment for prior-onset mental disorders. The population attributable risk proportion (PARP) for PEs associated with all CAs was 31% (24% for MFF). CONCLUSIONS: Exposure to CAs is associated with PE onset throughout the life-course, although sexual abuse is most strongly associated with childhood-onset PEs. The presence of mental disorders prior to the onset of PEs does not fully explain these associations. The large PARPs suggest that preventing CAs could lead to a meaningful reduction in PEs in the population.


Assuntos
Adultos Sobreviventes de Eventos Adversos na Infância/estatística & dados numéricos , Maus-Tratos Infantis/estatística & dados numéricos , Filho de Pais com Deficiência/estatística & dados numéricos , Saúde Global/estatística & dados numéricos , Transtornos Mentais/epidemiologia , Transtornos Psicóticos/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Masculino , Transtornos Mentais/etiologia , Prevalência , Transtornos Psicóticos/etiologia , Adulto Jovem
10.
J Magn Reson Imaging ; 45(2): 507-514, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27469307

RESUMO

PURPOSE: In 2015, an outbreak of group B streptococcal (GBS) infection caused by Streptococcus agalactiae Serotype III, multilocus sequence type 283, related to consuming infected raw freshwater fish, affected more than 200 patients in Singapore. We describe the clinical, laboratory, and neuroimaging features of a subgroup of adults with central nervous system (CNS) infections caused by GBS. MATERIALS AND METHODS: The database of the Singapore Neurologic Infections Program (SNIP), a national multicenter study for surveillance of infectious neurologic disease, was reviewed to select patients with GBS CNS infection during the outbreak. Cases were diagnosed on the basis of clinical features, cerebrospinal fluid (CSF) findings and identification or isolation of Streptococcus agalactiae in the blood or CSF. Demographic, clinical and neuroradiological information was obtained prospectively and retrospectively abstracted. RESULTS: Fourteen patients (6 male, 8 female; median age, 58 years) presented with fever, meningism, headache, encephalopathy, focal neurological deficits, and/or seizures. All except two were previously healthy. Diffusion-weighted imaging (DWI) on admission was abnormal in 13 patients, showing tiny hyperintensities in the subarachnoid space (7 patients), ventricles (6 patients) and brain parenchyma (8 patients); 5 patients had cerebellar abnormalities. CONCLUSION: Among healthy non-pregnant adults infected with Serotype III, multilocus sequence type 283 GBS meningitis linked to eating infected raw freshwater fish, DWI detected small pus collections and unusual cerebellar involvement. A collaborative national surveillance system that includes MRI can be helpful during unusual food-borne zoonotic infectious disease outbreaks. LEVEL OF EVIDENCE: 4 J. Magn. Reson. Imaging 2017;45:507-514.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Encefalite Infecciosa/diagnóstico por imagem , Meningites Bacterianas/diagnóstico por imagem , Meningites Bacterianas/epidemiologia , Infecções Estreptocócicas/diagnóstico por imagem , Infecções Estreptocócicas/epidemiologia , Streptococcus agalactiae , Surtos de Doenças/estatística & dados numéricos , Feminino , Humanos , Encefalite Infecciosa/epidemiologia , Masculino , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Singapura/epidemiologia
11.
Acta Psychiatr Scand ; 136(1): 74-84, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28542726

RESUMO

OBJECTIVE: While psychotic experiences (PEs) are known to be associated with a range of mental and general medical disorders, little is known about the association between PEs and measures of disability. We aimed to investigate this question using the World Mental Health surveys. METHOD: Lifetime occurrences of six types of PEs were assessed along with 21 mental disorders and 14 general medical conditions. Disability was assessed with a modified version of the WHO Disability Assessment Schedule. Descriptive statistics and logistic regression models were used to investigate the association between PEs and high disability scores (top quartile) with various adjustments. RESULTS: Respondents with PEs were more likely to have top quartile scores on global disability than respondents without PEs (19.1% vs. 7.5%; χ2  = 190.1, P < 0.001) as well as greater likelihood of cognitive, social, and role impairment. Relationships persisted in each adjusted model. A significant dose-response relationship was also found for the PE type measures with most of these outcomes. CONCLUSIONS: Psychotic experiences are associated with disability measures with a dose-response relationship. These results are consistent with the view that PEs are associated with disability regardless of the presence of comorbid mental or general medical disorders.


Assuntos
Pessoas com Deficiência/estatística & dados numéricos , Saúde Global/estatística & dados numéricos , Saúde Mental/estatística & dados numéricos , Transtornos Psicóticos/epidemiologia , Adulto , Inquéritos Epidemiológicos/estatística & dados numéricos , Humanos , Organização Mundial da Saúde
12.
Emerg Radiol ; 24(4): 427-430, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28417277

RESUMO

A 94-year-old Korean woman was seen in the Emergency Department after a fall. CT examination of the maxillofacial region found multiple small linear metallic densities in the subcutaneous soft tissues of the face. The appearance of these densities was unchanged when compared to a study performed 2 years prior; however, the imaging interpretations of these densities were markedly different. Additional imaging during the course of her hospital stay demonstrated numerous similar densities in the breasts, abdomen, hips, and legs-finally diagnosed as "charm needles." Although common practice in Southeast Asia, with ever increasing globalization, these needles, or "susuks," are being seen with greater frequency in North America. Here, we review the imaging appearance of a bizarre case of these charm needles so as to raise awareness of this potential diagnostic challenge and help the radiologist avoid confusion when interpreting images.


Assuntos
Técnicas Cosméticas , Corpos Estranhos/diagnóstico por imagem , Agulhas , Tomografia Computadorizada por Raios X , Idoso de 80 Anos ou mais , Feminino , Humanos , Achados Incidentais , República da Coreia/etnologia
13.
Phys Rev Lett ; 116(19): 190501, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-27232009

RESUMO

Imperfections in experimental measurement schemes can lead to falsely identifying, or over estimating, entanglement in a quantum system. A recent solution to this is to define schemes that are robust to measurement imperfections-measurement-device-independent entanglement witness (MDI-EW). This approach can be adapted to witness all entangled qubit states for a wide range of physical systems and does not depend on detection efficiencies or classical communication between devices. Here we extend the theory to remove the necessity of prior knowledge about the two-qubit states to be witnessed. Moreover, we tested this model via a novel experimental implementation for MDI-EW that significantly reduces the experimental complexity. By applying it to a bipartite Werner state, we demonstrate the robustness of this approach against noise by witnessing entanglement down to an entangled state fraction close to 0.4.

14.
Psychol Med ; 46(15): 3161-3172, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27572872

RESUMO

BACKGROUND: This is the first cross-national study of intermittent explosive disorder (IED). METHOD: A total of 17 face-to-face cross-sectional household surveys of adults were conducted in 16 countries (n = 88 063) as part of the World Mental Health Surveys initiative. The World Health Organization Composite International Diagnostic Interview (CIDI 3.0) assessed DSM-IV IED, using a conservative definition. RESULTS: Lifetime prevalence of IED ranged across countries from 0.1 to 2.7% with a weighted average of 0.8%; 0.4 and 0.3% met criteria for 12-month and 30-day prevalence, respectively. Sociodemographic correlates of lifetime risk of IED were being male, young, unemployed, divorced or separated, and having less education. The median age of onset of IED was 17 years with an interquartile range across countries of 13-23 years. The vast majority (81.7%) of those with lifetime IED met criteria for at least one other lifetime disorder; co-morbidity was highest with alcohol abuse and depression. Of those with 12-month IED, 39% reported severe impairment in at least one domain, most commonly social or relationship functioning. Prior traumatic experiences involving physical (non-combat) or sexual violence were associated with increased risk of IED onset. CONCLUSIONS: Conservatively defined, IED is a low prevalence disorder but this belies the true societal costs of IED in terms of the effects of explosive anger attacks on families and relationships. IED is more common among males, the young, the socially disadvantaged and among those with prior exposure to violence, especially in childhood.


Assuntos
Alcoolismo/epidemiologia , Transtorno Depressivo/epidemiologia , Transtornos Disruptivos, de Controle do Impulso e da Conduta/epidemiologia , Trauma Psicológico/epidemiologia , Delitos Sexuais/estatística & dados numéricos , Violência/estatística & dados numéricos , Adolescente , África/epidemiologia , Idade de Início , Ásia/epidemiologia , Comorbidade , Estudos Transversais , Manual Diagnóstico e Estatístico de Transtornos Mentais , Europa (Continente)/epidemiologia , Feminino , Humanos , América Latina/epidemiologia , Masculino , Oriente Médio/epidemiologia , Prevalência , Fatores de Risco , Inquéritos e Questionários , Estados Unidos/epidemiologia , Adulto Jovem
17.
Phys Rev Lett ; 111(13): 130406, 2013 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-24116754

RESUMO

We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.

19.
Clin Radiol ; 67(4): 380-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22137800

RESUMO

Cavernous haemangiomas (CH) are relatively uncommon non-shunting vascular malformations of the central nervous system and can present with seizures or with neurological deficits due to haemorrhage. Radiologists can often suggest the diagnosis of CH based on characteristic magnetic resonance imaging (MRI) features, thus avoiding further invasive procedures such as digital subtraction angiography or surgical biopsy. Although typical MRI appearance combined with the presence of multiple focal low signal lesions on T2*-weighted images or the presence of one or more developmental venous anomaly within the brain can improve the diagnostic confidence, serial imaging studies are often required if a solitary CH presents at a time when the imaging appearances had not yet matured to the typical "popcorn" appearance.


Assuntos
Encéfalo , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico , Imageamento por Ressonância Magnética , Medula Espinal , Hemorragia Cerebral/diagnóstico , Hemorragia Cerebral/etiologia , Hemangioma Cavernoso do Sistema Nervoso Central/complicações , Hemangioma Cavernoso do Sistema Nervoso Central/congênito , Hemangioma Cavernoso do Sistema Nervoso Central/cirurgia , Humanos
20.
J Phys Condens Matter ; 34(32)2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35580583

RESUMO

In an effort to gain insight into enantiomeric transitions, their transition mechanism, time span of transitions and distribution of time spans etc, we performed molecular dynamics (MD) simulations on chiral clusters Au10, Au15and Au18, and found that viable reaction coordinates can be deduced from simulation data for enlightening the enantiomeric dynamics for Au10and Au15, but not so for Au18. The failure in translating the Au18-L ⇌ Au18-R transitions by MD simulations has been chalked up to the thermal energykBTat 300 K being much lower than energy barriers separating the enantiomers of Au18. Two simulation strategies were taken to resolve this simulation impediment. The first one uses the well-tempered metadynamics MD (MMD) simulation, and the second one adeptly applies first a somewhat crude MMD simulation to locate a highly symmetrical isomer Au18Sand subsequently employed it as initial configuration in the MD simulation. In both strategies, we work in collective variable space of lower dimensionality. The well-tempered MMD simulation tactic was carried out aiming to offer a direct verification of Au18enantiomers, while the tactic to conduct MMD/MD simulations in two consecutive simulation steps was intended to provide an indirect evidence of the existence of enantiomers of Au18given that energy barriers separating them are much higher than ca.kBTat 300 K. This second tactic, in addition to confirming indirectly Au18-L and Au18-R starting from the symmetrical cluster Au18S, the simulation results shed light also on the mechanism akin to associative/nonassociative reaction transitions.

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