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1.
Phys Rev Lett ; 125(21): 210505, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33274991

RESUMO

We report long coherence times (up to 300 ms) for near-surface bismuth donor electron spins in silicon coupled to a superconducting microresonator, biased at a clock transition. This enables us to demonstrate the partial absorption of a train of weak microwave fields in the spin ensemble, their storage for 100 ms, and their retrieval, using a Hahn-echo-like protocol. Phase coherence and quantum statistics are preserved in the storage.

2.
J Magn Reson ; 310: 106662, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31837553

RESUMO

In EPR, spin relaxation is typically governed by interactions with the lattice or other spins. However, it has recently been shown that given a sufficiently strong spin-resonator coupling and high resonator quality factor, the spontaneous emission of microwave photons from the spins into the resonator can become the main relaxation mechanism, as predicted by Purcell. With increasing attention on the use of microresonators for EPR to achieve high spin-number sensitivity it is important to understand how this novel regime influences measured EPR signals, for example the amplitude and temporal shape of the spin-echo. We study this regime theoretically and experimentally, using donor spins in silicon, under different conditions of spin-linewidth and coupling homogeneity. When the spin-resonator coupling is distributed inhomogeneously, we find that the effective spin-echo relaxation time measured in a saturation recovery sequence strongly depends on the parameters for the detection echo. When the spin linewidth is larger than the resonator bandwidth, the different Fourier components of the spin echo relax with different characteristic times - due to the role of the resonator in driving relaxation - which results in the temporal shape of the echo becoming dependent on the repetition time of the experiment.

3.
Traffic Inj Prev ; 20(2): 169-173, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30888879

RESUMO

OBJECTIVE: Fractures are a common injury among motorcycle riders and can have serious health implications. Impact protection (IP) has been designed to help prevent fractures, yet there are conflicting opinions as to whether this IP does in fact help prevent fractures in real-world crashes. This work aimed to (1) use simulated dummy impacts to examine whether existing types of IP could reduce the force transferred to the underlying bone to below fracture tolerance levels and (2) investigate whether current European Standard (EN 1621-1) test procedures for impact protectors designed for motorcyclists are sufficient to ensure fracture protection. METHOD: Twenty-three shoulder and 7 knee IP specimens were tested using a 23-kg impactor contacting axially along the clavicle and femur of an anthropomorphic test device (ATD) at an energy level corresponding to the fracture tolerance of these bones. Sixteen IP specimens were the same as those worn by motorcycle riders involved in crashes where injury outcome was known (knee: n = 3; shoulder: n = 13) and the IP had been previously tested to EN 1621-1. Other IP tested represented a wide range of IP available for purchase at a motorcycle accessory store. Double and triple layers of IP were also tested. Energy attenuated during the dummy impacts was compared to energy attenuated when tested to EN 1621-1. RESULTS: Of the 23 shoulder IP tested, the average percentage reduction of transferred force to the shoulder from the baseline test was 7.6 ± 4.8%. The percentage reduction of transferred force to the knee from the baseline was 43.9 ± 7.5%. The entire group of knee IP tested reduced the transferred force to the knee to below the 10-kN injury threshold for the femur. There was a positive but nonsignificant correlation between the ATD test and the EN 1621-1 impact test performance, suggesting that the European standard test method likely provides a good indication of IP performance. However, given the low correlation coefficient, the relationship between IP performance in the European standard test method and injury protection remains unclear. CONCLUSION: Though the energy attenuation test method in the European standard may be an appropriate approach, distinct differences in injury protection performance observed between knee and shoulder IP indicate that there may be a need for different performance criteria for IP designated to protect different body regions.


Assuntos
Acidentes de Trânsito , Fraturas Ósseas/prevenção & controle , Traumatismos do Joelho/prevenção & controle , Motocicletas , Roupa de Proteção/normas , Lesões do Ombro/prevenção & controle , Antropometria/instrumentação , Humanos , Manequins
4.
J Anxiety Disord ; 60: 20-25, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30336368

RESUMO

Distress tolerance (DT), defined as the perceived and/or actual behavioral capacity to tolerate negative emotional states, is considered an important risk factor for various externalizing and internalizing disorders. Despite the importance of DT in the development and maintenance of psychopathology, few reliable and valid indicators of DT have been developed. One potentially useful way to assess DT is through interpretation bias (IB) paradigms. The current study sought to examine the convergent validity, reliability, and clinical utility of a DT-focused IB paradigm by directly measuring an individual's interpretations of distressing information. Participants completed a DT-IB task and self-report questionnaires. Results found an association between DTS self-report and an exaggerated DT-IB. Reliability analyses found the word pairings in our DT-IB task to display good internal consistency. In addition, an exaggerated DT-IB was associated with diagnostic status after covarying for negative affect and self-report DTS and DT-IB was associated with increased levels of negative affect above and beyond self-report DTS. This study is the first to identify specific interpretation biases for distress-related information. Given the transdiagnostic nature of DT and the efficacy and accessibility associated with CBM-I protocols for related constructs, the present findings add considerably to a growing body of literature.


Assuntos
Adaptação Psicológica , Emoções , Estresse Psicológico/psicologia , Feminino , Humanos , Masculino , Preconceito , Reprodutibilidade dos Testes , Fatores de Risco , Autorrelato , Inquéritos e Questionários , Adulto Jovem
5.
Pediatrics ; 95(5): 767-71, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7536916

RESUMO

OBJECTIVE: To report the clinical course, imaging findings, and method of diagnosis of two patients with systemic manifestations of cat scratch disease, presenting with fever of unknown origin. DESIGN: Case study. PATIENTS: Two children with fever of unknown origin who had multiple lesions in the liver and spleen, shown on ultrasound, computed tomography, and magnetic resonance imaging. Initial diagnoses were Kawasaki disease (case 1) and metastatic neuroblastoma (case 2). RESULTS: Biopsy material showed granulomatous hepatitis in both patients. The diagnoses were confirmed by positive assays for Rochalimaea henselae, currently thought to be the causative agent of cat scratch disease. CONCLUSION: Cat scratch disease presenting as fever of unknown origin is now well described and can be more readily diagnosed because of the availability of new serologic assays, as well as polymerase chain reaction assays for R henselae DNA in tissue specimens.


Assuntos
Bartonella henselae , Doença da Arranhadura de Gato/complicações , Febre de Causa Desconhecida/etiologia , Doença da Arranhadura de Gato/diagnóstico , Doença da Arranhadura de Gato/microbiologia , Criança , Pré-Escolar , Erros de Diagnóstico , Feminino , Granuloma/diagnóstico , Granuloma/etiologia , Hepatite/diagnóstico , Hepatite/etiologia , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/secundário , Imageamento por Ressonância Magnética , Masculino , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Tomografia Computadorizada por Raios X , Ultrassonografia
6.
Clin Exp Rheumatol ; 8(3): 271-81, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2379342

RESUMO

Blood, plasma and serum viscosity and blood filtration were investigated in 43 unselected mixed cryoglobulinemia patients. A hyperviscosity syndrome was present in only one patient, and rapidly improved after plasma exchange and cyclophosphamide therapy. A clear-cut increase in blood viscosity was infrequently observed in mixed cryoglobulinemia, although significant differences were present in the plasma and serum viscosity of patients and controls. In contrast, blood filtration was severely impaired in a high percentage of cases (51 and 72% of the values recorded at 37 degrees and 25 degrees C, respectively), and was on the average significantly higher in patients than in controls. Indirect evidence suggests that blood viscosity is at least in part related to cryoglobulins. In 19 patients studied before and after cryoglobulin removal, serum viscosity significantly decreased when the serum was deprived of cryoglobulins. In addition, the cryocrit correlated with all the hemorheological parameters with the exception of blood filtration. The hemorheological findings were compared with multisystemic features of the disease, i.e. liver, renal, lung, neurologic, vascular and funduscopic alterations. The potential clinical relevance of the hemorheological parameters was stressed by the close correlation between blood filtration parameters and serum creatinine. Furthermore, by discriminant analysis, viscosity and blood filtration changes were the serological parameters most significantly associated with the presence of renal, liver and neurological involvement. Thus, hemorheological parameters are frequently abnormal in mixed cryoglobulinemia patients, and seem to play a significant clinical role; they should therefore be included in the work-up of these patients.


Assuntos
Viscosidade Sanguínea , Crioglobulinemia/sangue , Hemofiltração , Adulto , Idoso , Animais , Crioglobulinemia/complicações , Crioglobulinas/análise , Análise Discriminante , Estudos de Avaliação como Assunto , Feminino , Fibrinogênio/análise , Fundo de Olho , Hematócrito , Humanos , Masculino , Análise de Regressão , Reologia , Fator Reumatoide/análise , Temperatura
7.
Minerva Med ; 76(7): 269-75, 1985 Feb 25.
Artigo em Italiano | MEDLINE | ID: mdl-3974940

RESUMO

Ten subjects with peripheral arterial occlusive disease were treated with buflomedil, analysing the effect of every single intravenous administration of the drug, and the effect of the administration repeated for a period of 5 days. This controlled study was aimed at evaluating the state of the peripheral blood flow, not just relating to the flowmetric parameters, but also to those more directly connected to the metabolic and functional conditions of the microcirculation. During every single administration, blood flow, skin and muscular temperatures were recorded. As concerned the drug's chronic effect, endurance limit, skin and muscular temperatures, whole blood viscosity, plasma viscosity and red cell filterability were recorded before beginning the treatment and after 15 days. The results of this study show that during a single buflomedil infusion no modifications have been observed in blood flow and muscular temperature, whereas skin temperature showed a slight increase. On the contrary, after a 15 days treatment, muscular temperature and endurance limit significantly increased, without flowmetric changes. A significant decrease in values of blood viscosity at high shear-rate was recorded too. The overall results seem to indicate that after treatment with buflomedil there is an improvement of the metabolic muscular conditions, probably due to a stimulant effect of the drug on microcirculatory blood flow.


Assuntos
Arteriopatias Oclusivas/tratamento farmacológico , Velocidade do Fluxo Sanguíneo , Pirrolidinas/administração & dosagem , Reologia , Temperatura , Idoso , Viscosidade Sanguínea/efeitos dos fármacos , Esquema de Medicação , Hematócrito , Humanos , Claudicação Intermitente/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Músculos , Temperatura Cutânea/efeitos dos fármacos
8.
Environ Manage ; 24(2): 265-271, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10384034

RESUMO

/ Utilization of parking lots around Hattiesburg, Mississippi, USA, was examined to suggest mechanisms for reducing runoff into local streams. Stream health was assessed by a census of fish communities. We found that most parking lots were used well below capacity, even in the peak shopping period before the Christmas holiday. Levels of utilization were primarily determined by shopping center age and parking availability relative to the size of businesses served. Streams receiving runoff had high undercut banks and heavy sediment loads. Their fish faunas were depauperate compared with a similar-sized stream in a nearby rural area. To moderate the impact of runoff, we recommend that lot size be carefully calibrated to actual parking demand. New businesses should be encouraged to establish in existing, unused parking lots rather than constructing new parking areas.KEY WORDS: Drainage; Fish communities; Mississippi; Parking utilization; Runoff; Suburbs; Urbanizationhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n2p265.html

9.
Ann Fr Anesth Reanim ; 22(8): 721-9, 2003 Oct.
Artigo em Francês | MEDLINE | ID: mdl-14522392

RESUMO

OBJECTIVE: To analyze the pattern of adhesion molecules in patients with septic shock. Data sources. - References obtained from Pubmed databank. DATA EXTRACTION: Models of inflammation linking endothelial dysfunction, adhesion molecules and septic states were analyzed. DATA SYNTHESIS: The endothelium has been identified as the central effector in the inflammatory response. Adhesion molecules are strongly involved in the inflammatory process by modulating the leukocyte trafficking. The most important adhesion molecules are the selectins (E-, L-, and P-selectins) and members of the immunoglobulin superfamily (intercellular adhesion molecule-1 and vascular cell adhesion molecule-1). Plasma levels of these molecules are increased in septic shock patients, which may be related to a marked activation of the endothelium. However, a dichotomous profile is observed between plasma and tissue expression. The inhibition of adhesive molecule actions could make it possible to control the inflammatory response.


Assuntos
Moléculas de Adesão Celular/metabolismo , Choque Séptico/metabolismo , Animais , Endotélio Vascular/patologia , Humanos , Hipóxia/metabolismo , Inflamação/metabolismo , Inflamação/patologia , Óxido Nítrico/metabolismo , Choque Séptico/patologia
11.
Ric Clin Lab ; 13 Suppl 3: 469-73, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6231714

RESUMO

The hemorheological findings obtained from a study employing an infusion of thymoxamine in saline solution and after the addition of the same drug to blood samples in vitro are reported. The hemorheological changes observed in vivo (decrease of both hematocrit and blood viscosity at shear rates of 23 and 230 sec-1) are not seen in vitro. From these data it is possible to conclude that such modifications produced by thymoxamine in vivo are more likely due to its alpha-blocking action than to a direct hemorheological activity of this drug.


Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Hematócrito , Moxisilita/farmacologia , Eritrócitos/fisiologia , Humanos , Reologia , Fatores de Tempo
12.
Ric Clin Lab ; 13 Suppl 3: 445-50, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6369495

RESUMO

The aim of our research was to investigate the effect of prostacyclin (PGI2) on red blood cell deformability and blood viscosity. Ten non-smokers healthy subjects (aged from 25 to 40) were examined. Different PGI2 concentrations were added to the blood sample and then red blood cell deformability and blood viscosity were measured: 1.2 and 2.4 ng/ml PGI2 concentrations, corresponding to plasma PGI2-like activity in man, increased red blood cell deformability and reduced blood viscosity. The PGI2 capacity of affecting red blood cell deformability and blood viscosity seems to be of clinical interest in conditions where the PGI2 production is reduced, such as ischemic heart disease, peripheral artery disease and diabetes mellitus.


Assuntos
Viscosidade Sanguínea/efeitos dos fármacos , Epoprostenol/farmacologia , Eritrócitos/fisiologia , Adulto , Eritrócitos/efeitos dos fármacos , Humanos , Ultrafiltração
13.
Ric Clin Lab ; 13 Suppl 3: 327-31, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6673008

RESUMO

The results from 398 consecutive measurements of blood viscosity, plasma viscosity and hematocrit were submitted to a statistical analysis. Hematocrit appeared to be the main determinant of blood viscosity, even though its influence was not so strong as illustrated in previous investigations. The correlation between blood viscosity and hematocrit appeared strictly connected with the red cell amount of the blood sample, being higher when the latter exceeded its physiological range; this correlation disappeared when red blood cell amount was strongly reduced, while the correlation between plasma viscosity and blood viscosity had an opposite behaviour. From these results we can conclude that correlations between hematocrit and plasma viscosity with blood viscosity have opposite trends and that a reciprocal interference is often present.


Assuntos
Viscosidade Sanguínea , Hematócrito , Contagem de Eritrócitos , Humanos , Estatística como Assunto
14.
Ric Clin Lab ; 13 Suppl 3: 333-6, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6673009

RESUMO

By means of the filterability test of Reid et al., the influence of a subpopulation of rigid erythrocytes (5% and 2.5%, respectively) was studied using Nucleopore polycarbonate membranes with pore size of 5 mu and diameter of 13 mm. The addition of 5% and 2.5% of rigid red cells delays the erythrocyte filtration times and alters the red cell deformability index. The meaning of the obtained data is discussed.


Assuntos
Eritrócitos/fisiologia , Ultrafiltração , Índices de Eritrócitos , Humanos , Fatores de Tempo
15.
Ric Clin Lab ; 13 Suppl 3: 337-40, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6673010

RESUMO

The findings of 300 consecutive measurements of erythrocyte filterability, whole blood viscosity, plasma viscosity, hematocrit, mean corpuscular volume and white blood cell count have been statistically analyzed in order to find a possible correlation between these parameters. No correlation between erythrocyte filterability, whole blood viscosity, plasma viscosity, hematocrit, mean corpuscular volume and white blood cell count was found. Some hypotheses are enunciated to explain such absence of correlation. The meaning of erythrocyte filtration test is still unclear.


Assuntos
Viscosidade Sanguínea , Eritrócitos/fisiologia , Ultrafiltração , Volume Sanguíneo , Hematócrito , Humanos , Contagem de Leucócitos , Modelos Biológicos
16.
Ric Clin Lab ; 13 Suppl 3: 209-18, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6672997

RESUMO

The relationships between blood rheology and peripheral arterial disease are reviewed. The connections between abnormal blood rheology and peripheral arterial disease are discussed considering the opinions of the enthusiastic and skeptic rheologists. A prospective for future investigations is also proposed.


Assuntos
Arteriopatias Oclusivas/sangue , Viscosidade Sanguínea , Contagem de Eritrócitos , Hematócrito , Humanos , Contagem de Leucócitos , Esforço Físico , Prognóstico , Reologia
17.
Ric Clin Lab ; 13 Suppl 3: 389-94, 1983.
Artigo em Italiano | MEDLINE | ID: mdl-6673018

RESUMO

The influence of an acute physical exercise on hemorheological parameters in insulin-dependent diabetes mellitus in not actually known. We have examined the behavior of hemorheological parameters and other laboratory findings such as blood glucose, blood lactic acid, O2 and CO2 venous pressure and venous pH before and after a submaximal physical exercise standardized by ECG monitoring and by means of an 'oxygen consumption computer'. The work load was significantly lower in diabetic patients than in normal control subjects. On the other hand, changes in hemorheological parameters were more evident in diabetic patients. The significance of these findings is also discussed.


Assuntos
Viscosidade Sanguínea , Diabetes Mellitus Tipo 1/sangue , Esforço Físico , Adolescente , Adulto , Sangue , Gasometria , Glicemia/análise , Feminino , Humanos , Lactatos/sangue , Ácido Láctico , Masculino , Consumo de Oxigênio , Reologia , Ultrafiltração
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