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1.
Phys Rev Lett ; 129(20): 203603, 2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36462023

RESUMO

Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an ultrabroad (1226-1408 nm) range in a group-velocity-symmetric photonic crystal fiber, covering over 150 independent frequency bins. The target wavelength is controlled by tuning only a single pump laser wavelength. We find internal, and total, conversion efficiencies of 12(1)% and 1.4(2)%, respectively. For the case of converting 1551 to 1300 nm we measure a heralded g^{(2)}(0)=0.25(6) for converted light from an input with g^{(2)}(0)=0.034(8). We expect that this photonic crystal fiber can be used for myriad quantum networking tasks.

2.
Nature ; 550(7675): 199-203, 2017 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-29022590

RESUMO

Heat is fundamental to power generation and many industrial processes, and is most useful at high temperatures because it can be converted more efficiently to other types of energy. However, efficient transportation, storage and conversion of heat at extreme temperatures (more than about 1,300 kelvin) is impractical for many applications. Liquid metals can be very effective media for transferring heat at high temperatures, but liquid-metal pumping has been limited by the corrosion of metal infrastructures. Here we demonstrate a ceramic, mechanical pump that can be used to continuously circulate liquid tin at temperatures of around 1,473-1,673 kelvin. Our approach to liquid-metal pumping is enabled by the use of ceramics for the mechanical and sealing components, but owing to the brittle nature of ceramics their use requires careful engineering. Our set-up enables effective heat transfer using a liquid at previously unattainable temperatures, and could be used for thermal storage and transport, electric power production, and chemical or materials processing.

3.
Law Hum Behav ; 40(4): 401-10, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27348716

RESUMO

Judges in the United States, the United Kingdom, and Canada have ruled that witnesses may not wear the niqab-a type of face veil-when testifying, in part because they believed that it was necessary to see a person's face to detect deception (Muhammad v. Enterprise Rent-A-Car, 2006; R. v. N. S., 2010; The Queen v. D(R), 2013). In two studies, we used conventional research methods and safeguards to empirically examine the assumption that niqabs interfere with lie detection. Female witnesses were randomly assigned to lie or tell the truth while remaining unveiled or while wearing a hijab (i.e., a head veil) or a niqab (i.e., a face veil). In Study 1, laypersons in Canada (N = 232) were more accurate at detecting deception in witnesses who wore niqabs or hijabs than in those who did not wear veils. Concealing portions of witnesses' faces led laypersons to change their decision-making strategies without eliciting negative biases. Lie detection results were partially replicated in Study 2, with laypersons in Canada, the United Kingdom, and the Netherlands (N = 291): observers' performance was better when witnesses wore either niqabs or hijabs than when witnesses did not wear veils. These findings suggest that, contrary to judicial opinion, niqabs do not interfere with-and may, in fact, improve-the ability to detect deception. (PsycINFO Database Record


Assuntos
Enganação , Tomada de Decisões , Percepção , Adulto , Canadá , Feminino , Humanos , Jurisprudência , Países Baixos , Distribuição Aleatória , Reino Unido
4.
Phys Rev Lett ; 110(13): 133601, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23581318

RESUMO

Single photons are a vital resource for optical quantum information processing. Efficient and deterministic single photon sources do not yet exist, however. To date, experimental demonstrations of quantum processing primitives have been implemented using nondeterministic sources combined with heralding and/or postselection. Unfortunately, even for eight photons, the data rates are already so low as to make most experiments impracticable. It is well known that quantum memories, capable of storing photons until they are needed, are a potential solution to this "scaling catastrophe." Here, we analyze in detail the benefits of quantum memories for producing multiphoton states, showing how the production rates can be enhanced by many orders of magnitude. We identify the quantity ηB as the most important figure of merit in this connection, where η and B are the efficiency and time-bandwidth product of the memories, respectively.

5.
Phys Rev Lett ; 111(24): 243601, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24483658

RESUMO

Optical quantum memories are vital for the scalability of future quantum technologies, enabling long-distance secure communication and local synchronization of quantum components. We demonstrate a THz-bandwidth memory for light using the optical phonon modes of a room temperature diamond. This large bandwidth makes the memory compatible with down-conversion-type photon sources. We demonstrate that four-wave mixing noise in this system is suppressed by material dispersion. The resulting noise floor is just 7×10(-3) photons per pulse, which establishes that the memory is capable of storing single quanta. We investigate the principle sources of noise in this system and demonstrate that high material dispersion can be used to suppress four-wave mixing noise in Λ-type systems.

6.
Phys Rev Lett ; 108(26): 263602, 2012 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-23004977

RESUMO

Quantum memories are vital to the scalability of photonic quantum information processing (PQIP), since the storage of photons enables repeat-until-success strategies. On the other hand, the key element of all PQIP architectures is the beam splitter, which allows us to coherently couple optical modes. Here, we show how to combine these crucial functionalities by addressing a Raman quantum memory with multiple control pulses. The result is a coherent optical storage device with an extremely large time bandwidth product, that functions as an array of dynamically configurable beam splitters, and that can be read out with arbitrarily high efficiency. Networks of such devices would allow fully scalable PQIP, with applications in quantum computation, long distance quantum communications and quantum metrology.

7.
Science ; 334(6060): 1253-6, 2011 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-22144620

RESUMO

Quantum entanglement in the motion of macroscopic solid bodies has implications both for quantum technologies and foundational studies of the boundary between the quantum and classical worlds. Entanglement is usually fragile in room-temperature solids, owing to strong interactions both internally and with the noisy environment. We generated motional entanglement between vibrational states of two spatially separated, millimeter-sized diamonds at room temperature. By measuring strong nonclassical correlations between Raman-scattered photons, we showed that the quantum state of the diamonds has positive concurrence with 98% probability. Our results show that entanglement can persist in the classical context of moving macroscopic solids in ambient conditions.

8.
Health Informatics J ; 17(1): 5-14, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25133765

RESUMO

Patient self-reporting of symptoms and quality of life following surgical interventions is generally delivered in the form of paper-based questionnaires to be completed in the outpatient clinic or at home. A commonly used tool for patient self-reporting of quality of life is the EQ5D health status questionnaire which, while limited in scope, has general applicability across a range of health interventions. In this article we examine the issues relating to online patient self-reporting using this questionnaire and the wider implications for the online reporting of health status.


Assuntos
Coleta de Dados , Atenção à Saúde/métodos , Nível de Saúde , Internet/estatística & dados numéricos , Autorrelato/estatística & dados numéricos , Inquéritos e Questionários/estatística & dados numéricos , Humanos
9.
Clin Radiol ; 63(3): 305-11, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18275871

RESUMO

AIM: To determine the current practice in the UK National Health Service Breast Screening Programme for invasive diagnostic procedures and surgery in patients taking anticoagulant and antiplatelet medication. MATERIALS AND METHODS: Lead radiologists and surgeons at each breast screening service were surveyed to determine current practice. One hundred and five respondents provided information regarding their services, protocols, and willingness to proceed with combinations of procedures and anti-haemostatic medications. RESULTS: Between units there was wide variation in practice. Within 21 services providing more than one response, 10 (48%) disagreed on whether protocols existed. Decisions to perform biopsies were unrelated to professional group. The taking of a drug history was variable. Surgeons reported more adverse effects than radiologists [21 (48%) versus 12 (26%)], but no difference in self-assessment of knowledge. CONCLUSION: Both radiologists and surgeons have expressed uncertainty about their understanding of anticoagulant and antiplatelet treatment. This is reflected in a wide range of practice. Guidance regarding the management of these patients is suggested.


Assuntos
Anticoagulantes/uso terapêutico , Neoplasias da Mama , Mama , Inibidores da Agregação Plaquetária/uso terapêutico , Atitude do Pessoal de Saúde , Biópsia , Mama/patologia , Mama/cirurgia , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Radiologia Intervencionista , Medição de Risco , Medicina Estatal , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Reino Unido
10.
Med Inform Internet Med ; 32(1): 35-41, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17365643

RESUMO

In the healthcare sector, where the decisions made by software aid in the direct treatment of patients, software requires high levels of assurance to ensure the correct interpretation of the tasks it is automating. This paper argues that introducing adaptable decision processes within eHealthcare initiatives can reduce software-maintenance complexity and, due to the instantaneous, distributed deployment of decision models, allow for quicker updates of current best practice, thereby improving patient care. The paper provides a description of a collection of technologies and tools that can be used to provide the required adaptation in a decision process. These tools are evaluated against two case studies that individually highlight different requirements in eHealthcare: a breast-cancer decision-support system, in partnership with several of the UK's leading cancer hospitals, and a dental triage in partnership with the Royal Liverpool Hospital which both show how the complete process flow of software can be abstracted and adapted, and the benefits that arise as a result.


Assuntos
Tomada de Decisões Assistida por Computador , Aplicações da Informática Médica , Design de Software , Neoplasias da Mama , Assistência Odontológica , Humanos , Triagem , Reino Unido
11.
Clin Radiol ; 61(3): 276-81, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16488210

RESUMO

AIM: To assess the impact of mammotome biopsy on preoperative diagnosis rate. METHODS: A prospective study was undertaken to examine the referral patterns, radiological abnormalities, sensitivity, specificity and outcome of the first 150 patients undergoing mammotome biopsy at our institution. Most of the referrals were from the NHS Breast Screening Programme (85/100). RESULTS: The commonest radiological abnormality was microcalcification (87%). The accuracy of this biopsy technique for the target lesion was over 99%. Post-biopsy, 11 patients needed to proceed to a diagnostic surgical biopsy (7%). Forty-two malignancies were identified at final histology; 41 were diagnosed preoperatively. The positive predictive of mammotome biopsy was 98% for the present study. The present results for mammotome biopsy with regard to predicting invasion were: sensitivity 71.4% (10/14); specificity 100% (0/0); positive predictive value 100% (10/10); and negative predictive value 87% (27/31). CONCLUSION: Prone mammotome biopsy has proven to be highly accurate, considerably improving the preoperative diagnosis within our unit, and obviating the majority of diagnostic excision biopsies.


Assuntos
Biópsia por Agulha/métodos , Neoplasias da Mama/patologia , Calcinose/patologia , Adulto , Idoso , Neoplasias da Mama/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Feminino , Humanos , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Padrões de Prática Médica , Cuidados Pré-Operatórios , Estudos Prospectivos , Radiografia , Encaminhamento e Consulta , Sensibilidade e Especificidade
12.
Breast ; 15(2): 210-8, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16081287

RESUMO

The aim of this study is to assess core specimens which do not contain radiographically visible calcification at stereotactic vacuum assisted core biopsy (SVACB) of indeterminate microcalcification, to determine what influence they may have on the surgical management of patients with breast disease. Review was made of the core biopsy and surgical histology results of 104 SVACB biopsies of indeterminate microcalcification over a 26 month period. Cores were placed in separate pots; POT A for cores containing microcalcification and POT B for cores without radiographically visible microcalcification before being sent to histology. Of 104 biopsies, 25% contained B3-B5 pathology in POT B and at surgery this correlated with a higher grade of ductal carcinoma in situ (DCIS) and an increased likelihood of invasive disease. The presence of B3-B5 pathology in POT B itself however did not act as a strong indicator of radiological-histological size discrepancy in this study.


Assuntos
Neoplasias da Mama/diagnóstico , Técnicas Estereotáxicas , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/etiologia , Neoplasias da Mama/patologia , Calcinose/diagnóstico , Calcinose/diagnóstico por imagem , Calcinose/epidemiologia , Calcinose/etiologia , Calcinose/patologia , Inglaterra/epidemiologia , Feminino , Humanos , Prontuários Médicos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Radiografia , Estudos Retrospectivos , Vácuo
13.
Breast ; 11(2): 107-15, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14965655

RESUMO

Accidental injury to the female breast can cause symptoms and signs which may mimic carcinoma and can also be painful or disfiguring. Nine women who sustained injury to the breast are presented, illustrating some of the manifestations of traumatic injury to the female breast, the majority of which are attributable to fat necrosis. A brief discussion of the clinical and imaging features of fat necrosis is included. These cases reinforce the importance of triple assessment in any woman presenting with a breast lump, even with a clear history of trauma.

14.
Breast ; 11(5): 394-7, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14965701

RESUMO

Breast papilloma are difficult to diagnose by triple assessment. Their symptoms, clinical signs and radiological appearances are differing widely. In this paper, we report the symptoms and clinical signs of 35 patients with proven breast papilloma and consider the relative merits of mammography, ultrasound scans and magnetic resonance imaging in their assessment.

15.
Org Lett ; 3(21): 3325-7, 2001 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-11594825

RESUMO

[reaction: see text]. N-benzoylated quinone imine ketals undergo smooth cycloadditions in a [4 + 2] sense to yield the expected cycloadducts. The crude cycloadducts, when subjected to a short series of simple transformations, produce synthetically useful quantities of 5-methoxyindoles in excellent overall yields.


Assuntos
Indóis/síntese química , Aldeídos/química , Benzoquinonas/química , Química Farmacêutica , Iminas/química
16.
Am J Forensic Med Pathol ; 22(3): 313-8, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11563748

RESUMO

Hepatic glycogen stores have long been known to decrease with starvation, trauma, acute stress, and shock. In this study, hepatic tissue was examined in 122 decedents ranging in age from 1 to 88 years who died of a variety of causes. Hepatic tissue was stained for glycogen/carbohydrates using the Best's carmine and/or period acid-Schiff (PAS)-alcian blue methods in 121 cases. The liver samples were evaluated for amount of staining, staining around hepatic injuries (if present), and presence of histologic abnormalities. Prominence of staining was decreased with increasing survival times after injury (P=.0001) and increasing postmortem interval. Staining along the edges of hepatic injuries was decreased in antemortem injuries but not in postmortem-induced injuries (P<.0001). If used in conjunction with circumstantial and autopsy information, hepatic glycogen/carbohydrate staining using the Best's carmine and PAS-alcian blue methods could greatly aid in the determination of injury survival times and the vital nature of questionable injuries in child deaths and other cases.


Assuntos
Maus-Tratos Infantis , Glicogênio Hepático/análise , Fígado/lesões , Ferimentos e Lesões/patologia , Adulto , Idoso , Criança , Feminino , Medicina Legal/métodos , Histocitoquímica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Coloração e Rotulagem/métodos , Fatores de Tempo
17.
J Org Chem ; 66(13): 4704-9, 2001 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-11421796

RESUMO

Indoles which bear an alkyl substituent in the 3-position undergo a [3 + 2] annulation reaction when treated with 1,1-cyclopropane diesters in the presence of Yb(OTf)(3) resulting in 2,3-cyclopentanoindolines. Typically, the reactions are performed at elevated temperatures or at ultrahigh pressures. In cases where steric crowding is an issue, ultrahigh pressures are required. In reactions involving substituted cyclopropanes, significant regio- and diastereocontrol was observed. When the substituent was aromatic or olefinic, the reactions took place at ambient temperature and pressure. The applicability of this methodology to the preparation of a key tetracyclic subunit of the kopsane alkaloids was demonstrated.


Assuntos
Alcaloides/síntese química , Alcanos/química , Ciclopentanos/síntese química , Alcaloides/química , Ciclopentanos/química , Ciclopropanos/química , Indóis/química
18.
Breast ; 10(1): 38-40, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14965557

RESUMO

Invasive lobular breast carcinoma accounts for approximately 15% of all breast cancers and is difficult to detect using conventional breast imaging techniques. We report a comparison between clinical, ultrasound scan (USS), mammographic and magnetic resonance imaging (MRI) of 22 patients with invasive lobular breast carcinomas. Actual tumour size was ascertained by histopathology. MRI detected 21 of the 22 invasive lobular cancers whilst mammography and USS detected 16 and 20 respectively. 19 tumours were clinically palpable. MRI was more accurate at assessing tumour size than USS and clinical examination, both of which underestimated tumour size.

19.
Infect Immun ; 68(2): 658-63, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10639430

RESUMO

Arthritis is a frequent and major complication of infection with Borrelia burgdorferi sensu stricto. The antigens responsible for the induction of arthritis are unknown. Here we provide direct evidence that a major surface protein, outer surface protein A (OspA), can induce arthritis. Hamsters were vaccinated with 30, 60, or 120 microg of recombinant OspA (rOspA) in aluminum hydroxide and challenged with B. burgdorferi sensu stricto isolate 297 or C-1-11. Swelling of the hind paws was detected in 100, 100, and 50% of hamsters vaccinated with 30, 60, or 120 microg of rOspA, respectively. In addition, arthritis developed in 57% of hamsters vaccinated with a canine rOspA vaccine after infection with B. burgdorferi sensu stricto. When the canine rOspA vaccine was combined with aluminum hydroxide, all vaccinated hamsters developed arthritis after challenge with B. burgdorferi sensu stricto. Histopathologic examination confirmed the development of severe destructive arthritis in rOspA-vaccinated hamsters challenged with B. burgdorferi sensu stricto. These findings suggest that rOspA vaccines should be modified to eliminate epitopes of OspA responsible for the induction of arthritis. Our results are important because an rOspA vaccine in aluminum hydroxide was approved by the Food and Drug Administration for use in humans.


Assuntos
Antígenos de Superfície/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Lipoproteínas , Doença de Lyme/etiologia , Vacinas Sintéticas/imunologia , Animais , Cricetinae , Doença de Lyme/patologia , Vacinação
20.
Mol Microbiol ; 33(6): 1254-66, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10510239

RESUMO

In cell-free Pseudomonas aeruginosa culture supernatants, we identified two compounds capable of activating an N-acylhomoserine lactone (AHL) biosensor. Mass spectrometry and NMR spectroscopy revealed that these compounds were not AHLs but the diketopiperazines (DKPs), cyclo(DeltaAla-L-Val) and cyclo(L-Pro-L-Tyr) respectively. These compounds were also found in cell-free supernatants from Proteus mirabilis, Citrobacter freundii and Enterobacter agglomerans [cyclo(DeltaAla-L-Val) only]. Although both DKPs were absent from Pseudomonas fluorescens and Pseudomonas alcaligenes, we isolated, from both pseudomonads, a third DKP, which was chemically characterized as cyclo(L-Phe-L-Pro). Dose-response curves using a LuxR-based AHL biosensor indicated that cyclo(DeltaAla-L-Val), cyclo(L-Pro-L-Tyr) and cyclo(L-Phe-L-Pro) activate the biosensor in a concentration-dependent manner, albeit at much higher concentrations than the natural activator N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL). Competition studies showed that cyclo(DeltaAla-L-Val), cyclo(L-Pro-L-Tyr) and cyclo(L-Phe-L-Pro) antagonize the 3-oxo-C6-HSL-mediated induction of bioluminescence, suggesting that these DKPs may compete for the same LuxR-binding site. Similarly, DKPs were found to be capable of activating or antagonizing other LuxR-based quorum-sensing systems, such as the N-butanoylhomoserine lactone-dependent swarming motility of Serratia liquefaciens. Although the physiological role of these DKPs has yet to be established, their activity suggests the existence of cross talk among bacterial signalling systems.


Assuntos
Dipeptídeos/isolamento & purificação , Bactérias Gram-Negativas/metabolismo , Peptídeos Cíclicos/isolamento & purificação , Pseudomonas aeruginosa/metabolismo , 4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Técnicas Biossensoriais , Comunicação Celular , Dipeptídeos/química , Escherichia coli/metabolismo , Medições Luminescentes , Estrutura Molecular , Peptídeos Cíclicos/química , Fenótipo
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