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1.
J Leg Med ; 40(2): 247-263, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33137276

RESUMO

Medical photographs have been used for decades to document clinical findings. The ease with which medical photographs can be captured and integrated into the electronic health record (EHR) has increased as digital cameras obviated the need for the film development process. Today, cameras integrated into smartphones allow for high-resolution images to be instantly uploaded and integrated into the EHR. With major EHR vendors offering mobile smartphone applications for the conduct of point-of-care medical photography, health care providers and institutions need to be aware of legal questions that arise in the conduct of medical photography. Namely, (1) what are the requirements for consent when taking medical photographs, and how may photographs be used after consent is obtained, (2) are medical photographs admissible as evidence in court, and (3) how should a provider respond to a request by a patient or parent requesting that a photograph be deleted from the medical record? Herein, we review relevant laws and legal cases in the context of accepted standards of medical practice pertaining to point-of-care medical photography. This review is intended to aid health care providers and institutions seeking to develop or revise policies regarding using a mobile application at their clinical practice.


Assuntos
Registros Eletrônicos de Saúde/legislação & jurisprudência , Consentimento Livre e Esclarecido/legislação & jurisprudência , Aplicativos Móveis , Direitos do Paciente , Fotografação/legislação & jurisprudência , Health Insurance Portability and Accountability Act , Pessoal de Saúde/legislação & jurisprudência , Humanos , Política Organizacional , Sistemas Automatizados de Assistência Junto ao Leito , Smartphone , Estados Unidos
2.
Telemed Rep ; 2(1): 78-87, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35720756

RESUMO

Background: The Mayo Clinic Center for Connected Care has an established organizational framework for telehealth care delivery. It provides patients, consumers, care teams, and referring providers access to clinical knowledge through technologies and integrated practice models. Central to the framework are teams that support product management and operational functions. They work together across the asynchronous, synchronous video telemedicine, remote patient monitoring (RPM), and mobile core service lines. Methods: The organizational framework of the Center for Connected Care and Mayo Clinic telehealth response to the COVID-19 pandemic is described. Barriers to telehealth delivery that were addressed by the public health emergency are also reported. This report was deemed exempt from full review by the Mayo Clinic IRB. Results: After declaration of the COVID-19 pandemic, there was rapid growth in established telehealth offerings, including patient online services account creation, secure messaging, inpatient eConsults, express care online utilization, and video visits to home. Census for the RPM program for patients with chronic conditions remained stable; however, its framework was rapidly adapted to develop and implement a COVID-19 RPM service. In addition to this, other new telehealth and virtual care services were created to support the unique needs of patients with COVID-19 symptoms or disease and the health care workforce, including a digital COVID-19 self-assessment tool and video telemedicine solutions for ambulances, emergency departments, intensive care units, and designated medical-surgical units. Conclusion: Rapid growth, adoption, and sustainability of telehealth services through the COVID-19 pandemic were made possible by a scalable framework for telehealth and alignment of regulatory and reimbursement models.

3.
Dev Dyn ; 238(10): 2641-51, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19718764

RESUMO

Early expression of estrogen receptors (esr) and their role in regulating early expression of cyp19a1b encoding brain aromatase were examined in the brain of zebrafish. Using in toto hybridization and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), a significant increase in the expression of esr1, esr2a, and esr2b was observed between 24 and 48 hours postfertilization (hpf). In toto hybridization demonstrated that esr2a and esr2b, but not esr1, are found in the hypothalamus. Using real-time RT-PCR, an increase in cyp19a1b mRNAs occurs between 24 and 48 hpf, indicating that expression of cyp19a1b is temporally correlated with that of esr. This increase is blocked by the pure anti-estrogen ICI182,780. Furthermore, E2 treatment of cyp19a1b-GFP (green fluorescent protein) transgenic embryos results in appearance of GFP expression in the brain as early as 25 hpf. These results indicate that basal expression of cyp19a1b expression in the brain of developing zebrafish most likely relies upon expression of esr that are fully functional before 25 hpf.


Assuntos
Aromatase/metabolismo , Encéfalo , Embrião não Mamífero , Regulação da Expressão Gênica no Desenvolvimento , Receptores de Estrogênio/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra , Animais , Animais Geneticamente Modificados , Aromatase/genética , Encéfalo/embriologia , Encéfalo/enzimologia , Embrião não Mamífero/anatomia & histologia , Embrião não Mamífero/enzimologia , Estradiol/análogos & derivados , Estradiol/metabolismo , Antagonistas de Estrogênios/metabolismo , Fulvestranto , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Receptores de Estrogênio/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Peixe-Zebra/anatomia & histologia , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética
4.
JMIR Mhealth Uhealth ; 7(12): e14919, 2019 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-31793894

RESUMO

BACKGROUND: As mobile devices and apps grow in popularity, they are increasingly being used by health care providers to aid clinical care. At our institution, we developed and implemented a point-of-care clinical photography app that also permitted the capture of video recordings; however, the clinical findings it was used to capture and the outcomes that resulted following video recording were unclear. OBJECTIVE: The study aimed to assess the use of a mobile clinical video recording app at our institution and its impact on clinical care. METHODS: A single reviewer retrospectively reviewed video recordings captured between April 2016 and July 2017, associated metadata, and patient records. RESULTS: We identified 362 video recordings that were eligible for inclusion. Most video recordings (54.1%; 190/351) were captured by attending physicians. Specialties recording a high number of video recordings included orthopedic surgery (33.7%; 122/362), neurology (21.3%; 77/362), and ophthalmology (15.2%; 55/362). Consent was clearly documented in the medical record in less than one-third (31.8%; 115/362) of the records. People other than the patient were incidentally captured in 29.6% (107/362) of video recordings. Although video recordings were infrequently referenced in notes corresponding to the clinical encounter (12.2%; 44/362), 7.7% (22/286) of patients were video recorded in subsequent clinical encounters, with 82% (18/22) of these corresponding to the same finding seen in the index video. Store-and-forward telemedicine was documented in clinical notes in only 2 cases (0.5%; 2/362). Videos appeared to be of acceptable quality for clinical purposes. CONCLUSIONS: Video recordings were captured in a variety of clinical settings. Documentation of consent was inconsistent, and other individuals were incidentally included in videos. Although clinical impact was not always clearly evident through retrospective review because of limited documentation, potential uses include documentation for future reference and store-and-forward telemedicine. Repeat video recordings of the same finding provide evidence of use to track the findings over time. Clinical video recordings have the potential to support clinical care; however, documentation of consent requires standardization.


Assuntos
Medicina Clínica/instrumentação , Aplicativos Móveis/normas , Fotografação/ética , Sistemas Automatizados de Assistência Junto ao Leito/organização & administração , Gravação em Vídeo/instrumentação , Adulto , Idoso , Telefone Celular , Termos de Consentimento/ética , Documentação/normas , Feminino , Humanos , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Neurologia/estatística & dados numéricos , Oftalmologia/estatística & dados numéricos , Ortopedia/estatística & dados numéricos , Fotografação/métodos , Estudos Retrospectivos , Telemedicina/instrumentação
5.
Artigo em Inglês | MEDLINE | ID: mdl-18184509

RESUMO

This paper presents the potential safety benefits of the experimental French LAVIA Intelligent Speed Adaptation system, according to road network and system mode, based on observed driving speeds, distributions of crash severity and crash injury risk. Results are given for car frontal and side impacts that together, represent 80% of all serious and fatal injuries in France. Of the three system modes tested (advisory, driver select, mandatory), our results suggest that driver select would most significantly reduce serious injuries and death. We estimate this 100% utilization of cars equipped with this type of speed adaptation system would decrease injury rates by 6% to 16% over existing conditions depending on the type of crash (frontal or side) and road environment considered. Some limitations associated with the analysis are also identified. LAVIA is the acronym for Limiteur s'Adaptant à la VItesse Autorisée, a French Intelligent Speed Adaptation (ISA) project that was set up towards the end of 1999. At the time, 1998 French national road safety statistics recorded 8437 road related deaths, a figure which had shown virtually no positive evolution since 1994. Detailed analysis of the contributory factors involved in fatal road crashes highlighted the time-honoured crash and injury causation mechanisms - alcohol, speed and seatbelts. Of the three, excessive speed (over and above the posted speed limit) was a contributory factor in half of all fatal crashes Inappropriate behaviour such as excessive speeding can be dealt with either by legislative or driver-incentive programmes. The first of these two solutions involves the introduction of new legislation and/or the enforcement of existing laws. This is the domain of Public Authorities and will not be discussed in detail here. Alternatively, incentive schemes can involve the implementation of speed related driver assistance systems, categorised according to their voluntary or mandatory character and the degree of autonomy proposed to or imposed on the driver. The LAVIA project set out to address several possible combinations of these two factors. The generic term Intelligent Speed Adaptation (ISA) encompasses a wide range of different technologies aimed at improving road safety by reducing traffic speed and homogenising traffic flow, within the limit of posted speed limits. "Fixed speed limit" systems inform the vehicle of the posted speed limit whereas "variable speed limit" systems take into account certain locations on the road network where a speed below the posted limit is desirable, such as sharp curves, pedestrian crossings or crash black spots. Taken one step further, speed limit systems may also take into account weather and traffic flow conditions. These systems are known as "dynamic speed limit" systems and benefit from real time updates for a specific location. The different ISA systems are generally characterised by the degree of freedom of choice given to the driver in moderating his or her speed. Speed limit technologies may be advisory (informing drivers of the current speed limit and speed limit changes), voluntary (allowing the driver to decide whether or not to implement speed limitation) or mandatory (imposing the current speed limit). The information supplied may be provided by way of the road infrastructure (and associated equipment), may be acquired autonomously by the vehicle or may be based on an interaction between the infrastructure and the vehicle. Even the most basic of these systems should be considered as a very useful driver aid, helping the driver to stay within the posted speed limit, avoiding "unnecessary" speeding fines through inattention, modelling driver behaviour through the long term reduction of speeds and reducing driver workload by limiting visual speedometer controls. Vehicle-based ISA systems should not be confused with internal systems. These latter systems rely upon the driver entering the desired travel speed, which is then maintained by cruise control or set as a maximum value by automatic speed regulators. Although these systems will not be discussed in detail here, it should be noted that the engine management technologies that they employ are a vital component of ISA systems.


Assuntos
Acidentes de Trânsito/prevenção & controle , Acidentes de Trânsito/estatística & dados numéricos , Condução de Veículo/estatística & dados numéricos , Automóveis/estatística & dados numéricos , Promoção da Saúde , França , Humanos , Escala de Gravidade do Ferimento , Modelos Teóricos , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Medição de Risco
6.
PLoS One ; 12(9): e0183737, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28873392

RESUMO

The objective of this work is to develop a simple methodology for high resolution crop suitability analysis under current and future climate, easily applicable and useful in Least Developed Countries. The approach addresses both regional planning in the context of climate change projections and pre-emptive short-term rural extension interventions based on same-year agricultural season forecasts, while implemented with off-the-shelf resources. The developed tools are applied operationally in a case-study developed in three regions of Guinea-Bissau and the obtained results, as well as the advantages and limitations of methods applied, are discussed. In this paper we show how a simple approach can easily generate information on climate vulnerability and how it can be operationally used in rural extension services.


Assuntos
Agricultura/legislação & jurisprudência , Agricultura/métodos , Clima , Mudança Climática , Produtos Agrícolas , Ecologia , Geografia , Guiné-Bissau , Modelos Estatísticos , Estações do Ano , Classe Social
7.
Accid Anal Prev ; 38(2): 248-59, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16257384

RESUMO

To reduce the number and the gravity of accidents, it is necessary to analyse and reconstruct them. Accident modelling requires the modelling of the impact which in turn requires the estimation of the deformation energy. There are several tools available to evaluate the deformation energy absorbed by a vehicle during an impact. However, there is a growing demand for more precise and more powerful tools. In this work, we express the deformation energy absorbed by a vehicle during a crash as a function of the Energy Equivalent Speed (EES). The latter is a difficult parameter to estimate because the structural response of the vehicle during an impact depends on parameters concerning the vehicle, but also parameters concerning the impact. The objective of our work is to design a model to estimate the EES by using an original approach combining Bayesian and Neural Network approaches. Both of these tools are complementary and offer significant advantages, such as the guarantee of finding the optimal model and the implementation of error bars on the computed output. In this paper, we present the procedure for implementing this Bayesian Neural Network approach and the results obtained for the modelling of the EES: our model is able to estimate the EES of the car with a mean error of 1.34 m s(-1). Furthermore, we built a sensitivity analysis to study the relevance of model's inputs.


Assuntos
Acidentes de Trânsito , Teorema de Bayes , Modelos Teóricos , Redes Neurais de Computação , Física , Movimento (Física) , Fenômenos Físicos
8.
Mol Endocrinol ; 14(12): 1918-33, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11117523

RESUMO

The developmental expression patterns of the nuclear orphan receptors COUP-TFs (chicken ovalbumin upstream promoter-transcription factors) have been correlated to neurogenesis in several animal species. Nevertheless, the role of COUP-TFs in neurogenesis remains unknown. We have studied the functional involvement of COUP-TFI in retinoic acid (RA)-induced neuronal differentiation of P19 embryonal carcinoma cells through two complementary approaches: 1) deregulated expression of COUP-TFI, and 2) inactivation of endogenous COUP-TFs by means of a dominant-negative COUP-TFI mutant. Low levels of wild-type (wt)COUP-TFI transgene expression did not inhibit neural cell fate and primarily enhanced neuron outgrowth from RA-treated P19 aggregates. In contrast, high COUP-TFI expression impeded the neuronal differentiation of P19 cells induced with RA, resulting in cell cultures lacking neurons. This morphological effect was correlated to an elevated level of E-cadherin mRNA. The dominant-negative COUP-TFI mutant induced cell packing after RA treatment and inhibited neurite extension and neuron outgrowth from aggregates. A RGD peptide interference assay indicated that endogenous COUP-TFs could favor migration of neurons through an integrin-dependent mechanism. Accordingly, vitronectin mRNA levels were shown to be up-regulated by COUP-TFI by RT-PCR analysis, and COUP-TFI stimulated the mouse vitronectin promoter activity in transient transfection assays. Taken together, these data indicate that COUP-TFI is not simply a global repressor of retinoid functions, but shows a high selectivity for regulating genes involved in cellular adhesion and migration processes that are particularly important for neuronal differentiation.


Assuntos
Diferenciação Celular , Movimento Celular , Proteínas de Ligação a DNA/fisiologia , Neurônios/citologia , Fatores de Transcrição/fisiologia , Animais , Axônios/ultraestrutura , Sequência de Bases , Fator I de Transcrição COUP , Carcinoma Embrionário , Adesão Celular , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Humanos , Camundongos , Dados de Sequência Molecular , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Mutação Puntual , Regiões Promotoras Genéticas , Homologia de Sequência de Aminoácidos , Fatores de Transcrição/genética , Ativação Transcricional , Transfecção , Tretinoína/farmacologia , Células Tumorais Cultivadas , Vitronectina/genética , Vitronectina/metabolismo
9.
Accid Anal Prev ; 81: 24-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25935427

RESUMO

This study set out to evaluate the effectiveness of low speed autonomous emergency braking (AEB) technology in current model passenger vehicles, based on real-world crash experience. The validating vehicle safety through meta-analysis (VVSMA) group comprising a collaboration of government, industry consumer organisations and researchers, pooled data from a number of countries using a standard analysis format and the established MUND approach. Induced exposure methods were adopted to control for any extraneous effects. The findings showed a 38 percent overall reduction in rear-end crashes for vehicles fitted with AEB compared to a comparison sample of similar vehicles. There was no statistical evidence of any difference in effect between urban (≤60 km/h) and rural (>60 km/h) speed zones. Areas requiring further research were identified and widespread fitment through the vehicle fleet is recommended.


Assuntos
Aceleração , Acidentes de Trânsito/prevenção & controle , Automação , Automóveis , Emergências , Equipamentos de Proteção , Acidentes de Trânsito/mortalidade , Desenho de Equipamento , Humanos , Modelos Teóricos , Análise de Sobrevida , Ferimentos e Lesões/mortalidade , Ferimentos e Lesões/prevenção & controle
10.
J Mol Endocrinol ; 32(3): 975-86, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15171726

RESUMO

We have previously cloned and characterized three estrogen receptors (ER) in the zebrafish (zfERalpha, zfERbeta1 and zfERbeta2). We have also shown that they are functional in vitro and exhibit a distinct expression pattern, although partially overlapping, in the brain of zebrafish. In this paper, we have shown that the hepatic expression of these zfER genes responds differently to estradiol (E2). In fact, a 48-h direct exposure of zebrafish to E2 resulted in a strong stimulation of zfERalpha gene expression while zfERbeta1 gene expression was markedly reduced and zfERbeta2 remained virtually unchanged. To establish the potential implication of each zfER in the E2 upregulation of the zfERalpha gene, the promoter region of this gene was isolated and characterized. Transfection experiments with promoter-luciferase reporter constructs together with different zfER expression vectors were carried out in different cell contexts. The data showed that in vivo E2 upregulation of the zfERalpha gene requires ERalpha itself and a conserved transcription unit sequence including at least an imperfect estrogen-responsive element (ERE) and an AP-1/ERE half site at the proximal transcription initiation site. Interestingly, although in the presence of E2 zfERalpha was the most potent at inducing the expression of its own gene, the effect of E2 mediated by zfERbeta2 represented 50% of the zfERalpha activity. In contrast, zfERbeta1 was unable to upregulate the zfERalpha gene whereas this receptor form was able to tightly bind E2 and activate a reporter plasmid containing a consensus ERE. Altogether, these results indicated that the two ERbeta forms recently characterized in teleost fish could have partially distinct and not redundant functions.


Assuntos
Estradiol/metabolismo , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/metabolismo , Isoformas de Proteínas/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Sequência de Bases , Receptor alfa de Estrogênio/genética , Receptor beta de Estrogênio/genética , Regulação da Expressão Gênica , Humanos , Fígado/fisiologia , Dados de Sequência Molecular , Mutação , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Alinhamento de Sequência , Sítio de Iniciação de Transcrição , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/genética
11.
Thromb Haemost ; 79(1): 38-41, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9459319

RESUMO

STUDY OBJECTIVE: To determine the clinical usefulness of D-dimer ELISA test in elderly patients with clinically suspected pulmonary embolism (PE). DESIGN: Prospective cohort study. PATIENTS: Ninety-six consecutive outpatients older than 70 years with a duration of symptoms shorter than one week and without metastatic cancer or recent surgery, trauma, infection, stroke, myocardial infarction, deep vein thrombosis (DVT) or PE, or treatment with curative doses of heparin or oral anticoagulant. INTERVENTION: All patients underwent at least ventilation/perfusion scan and bilateral ultrasonic duplex scan and a blood sample collection within 24 hours of admission. When necessary a pulmonary angiography and/or a bilateral venography were also performed. Patients were classified as follows: (1) PE-positive: positive angiography or high probability V/Q scan and deep vein thrombosis (proven either by venography or by ultrasonic duplex scan) or non high probability V/Q scan and either DVT (proven at presentation by venography or by ultrasonic duplex scan) or symptomatic thromboembolic event within 3 months of follow-up; or (2) PE-negative; normal V/Q scan or normal angiography or non high probability V/Q scan and either negative ultrasonic duplex scan or normal venography and low clinical probability and absence of symptomatic thromboembolism within 3 months of follow-up. D-dimer measurements were performed using both a conventional and a single semi-quantitative ELISA test (Asserachrom D-di, Instant I.A.D-dimer). RESULTS: Using a cutoff value of 500 ng/ml, the conventional ELISA D-dimer test showed a sensitivity and a negative predictive value of 100% with poor specificity and positive predictive value of 14.3% and 45.5% respectively. The new rapid semi-quantitative D-dimer test displays worse results with sensitivity, negative predictive value, specificity and positive predictive value of 92.3%, 82.4%, 25% and 46% respectively. CONCLUSION: In a geriatric population, conventional ELISA D-dimer is a good marker to exclude PE but, due to the comorbid conditions, only a few patients presented with D-dimer values less than 500 ng/ml.


Assuntos
Ensaio de Imunoadsorção Enzimática , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Embolia Pulmonar/diagnóstico , Idoso , Biomarcadores/sangue , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Embolia Pulmonar/sangue
12.
Chest ; 106(5): 1607-9, 1994 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-7956432

RESUMO

Inferior vena cava thrombosis is a major complication after filter placement. The thrombus can propagate through the filter leading to a high risk of pulmonary embolism. We report such a case in a patient with a Günther filter, successfully treated with urokinase, and we discuss the efficacy and the safety of thrombolytic therapy in such situations.


Assuntos
Terapia Trombolítica/métodos , Trombose/tratamento farmacológico , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Filtros de Veia Cava , Veia Cava Inferior , Doença Aguda , Idoso , Feminino , Veia Femoral , Humanos , Embolia Pulmonar/prevenção & controle , Recidiva
13.
Ann N Y Acad Sci ; 618: 159-65, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2006785

RESUMO

Arterial thromboembolic disorders are the leading cause of death in most of the advanced nations. The study of epidemiologic relationship of these disorders to biological rhythms may lead to a better understanding and perhaps a better treatment. Chronoepidemiologic studies demonstrated a morning peak for arterial thromboembolic disorders (cerebral and myocardial infarctions) and sudden cardiac deaths. These variations might be explained partially by circadian variations in hemostasis. Indeed chronophysiologic studies have shown that hemostatic variables follow circadian rhythms. The level of platelet aggregation and that of blood coagulation have been found to be increased in the morning whereas fibrinolytic activity is lower at this time of the day. The facts suggest a chronotherapeutic approach in thromboembolic disorders.


Assuntos
Coagulação Sanguínea , Transtornos Cerebrovasculares/sangue , Ritmo Circadiano , Doença das Coronárias/sangue , Animais , Transtornos Cerebrovasculares/tratamento farmacológico , Doença das Coronárias/tratamento farmacológico , Morte Súbita , Fibrinolíticos/uso terapêutico , Humanos , Embolia e Trombose Intracraniana/tratamento farmacológico , Infarto do Miocárdio/sangue , Infarto do Miocárdio/tratamento farmacológico , Agregação Plaquetária
14.
Microsc Res Tech ; 23(3): 243-7, 1992 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-1472752

RESUMO

Experimental d-spacing values are criteria towards the identification of crystallites by electron diffraction. Conclusive identifications often rely on accurate d-spacings. It is shown here that accurate orthogonal components (in mm) for the primitive unit vectors of a zero-level diffraction pattern can be obtained through least-squares processing of (x,y) coordinates for all spots on the film. Valid vectors from the origin spot to any spot in the plane of the film are integer linear combinations of the two selected unit vectors. Accurate lengths and standard deviations for such vectors therefore can be calculated from the least-squares results. Corresponding d-spacings can then be calculated from the vector lengths on the film and the camera constant. In order to obtain d-spacing values that are not only precise, but also accurate, an accurate value of the camera constant should be used. This requires calibration of the experimental setup with reference materials in the same experimental conditions, with careful control of the sample height. For the same quality of measurements, the improvement in the accuracy of the d-spacings obtained with the proposed method is approximately proportional to the square root of the number of measurements taken. Practically, typical improvement in accuracy is about threefold, and accuracies of a fraction of a percent in d-spacings are achievable in this way. The above approach has been programmed as an option in the NRCBED program.


Assuntos
Difração de Raios X/métodos , Cristalização , Processamento de Imagem Assistida por Computador , Matemática
15.
Microsc Res Tech ; 21(2): 158-65, 1992 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1558984

RESUMO

A new method for the ab initio derivation of Buerger-reduced primitive cell parameters from coordinate measurements of spots on single convergent-beam electron diffraction (CBED) patterns is described, which does not involve trial-and-error. The pattern can be taken along any zone axis, and misorientations of the crystallite by as much as a few degrees are taken into account without loss of accuracy. This derivation of cell parameters by least-squares analysis of the measurements has been automated in a program called NRCBED. Present accuracy is about 1% on lengths and 2 degrees on angles, but could be significantly improved by modelling projector lens aberrations, or by using a microscope without a projector lens. With present technology, it is possible to obtain a CBED pattern and a semi-quantitative energy-dispersive X-ray (EDX) analysis simultaneously from a single microcrystal a few hundred Angströms across. It becomes therefore possible to identify the material of the crystal on a single CBED pattern: a cell parameter database for known compounds is searched with the primitive cell parameters obtained in the above way, and with a mask describing the EDX results qualitatively. Feasibility is demonstrated on a crystallite of CeO2 500 Angströms across. With this new approach, trial-and-error should disappear from the solution of other long-standing problems: interpretation of X-ray powder patterns for new compounds in the presence of impurity lines, or in the case of multiple phases should become straight-forward.


Assuntos
Cristalografia/métodos , Técnicas Citológicas , Cério/química , Microanálise por Sonda Eletrônica/métodos
16.
AJNR Am J Neuroradiol ; 14(2): 489-90, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8456734

RESUMO

Neurologic manifestations occur in over 90% of patients with thrombotic thrombocytopenic purpura. Neuropathologically, thrombi produce occlusion of terminal arterioles and capillaries resulting in diffuse small infarcts. In the great majority of surviving patients, brain CT does not disclose any abnormalities. The authors report a case of thrombotic thrombocytopenic purpura in which brain MR examination showed multiple punctate lesions in the white matter.


Assuntos
Encéfalo/patologia , Imageamento por Ressonância Magnética , Púrpura Trombocitopênica Trombótica/patologia , Adulto , Humanos , Masculino , Púrpura Trombocitopênica Trombótica/complicações , Convulsões/complicações , Convulsões/diagnóstico
17.
Accid Anal Prev ; 33(3): 371-85, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11235799

RESUMO

The objective of this paper is to compare safety levels and trends in OECD countries from 1980 to 1994 with the help of a statistical model and to launch international discussion and further research about international comparisons. Between 1980 and 1994, the annual number of fatalities decreased drastically in all the selected countries except Japan (+ 12%), Greece (+ 56%) and ex-East Germany (+ 50%). The highest decreases were observed in ex-West Germany (- 48%), Switzerland (- 44%), Australia (- 40%), and UK (- 39%). In France, the decrease in fatalities over the same period reached 34%. The fatality rate, an indicator of risk, decreased in the selected countries from 1980 to 1994 except in the east-European countries during the motorization boom in the late 1980s. As fatality rates are not sufficient for international comparisons, a statistical multiple regression model is set up to compare road safety levels in 21 OECD countries over 15 years. Data were collected from IRTAD (International Road Traffic and Accident Database) and other OECD statistical sources. The number of fatalities is explained by seven exogenous (to road safety) variables. The model, pooling cross-sectional and time series data, supplies estimates of elasticity to the fatalities for each variable: 0.96 for the population; 0.28 for the vehicle fleet per capita; -0.16 for the percentage of buses and coaches in the motorised vehicle fleet; 0.83 for the percentage of youngsters in the population; - 0.41 for the percentage of urban population; 0.39 for alcohol consumption per capita; and 0.39 for the percentage of employed people. The model also supplies a rough estimate of the safety performance of a country: the regression residuals are supposed to contain the effects of essentially endogenous and unobserved variables, independent to the exogenous variables. These endogenous variables are safety performance variables (safety actions, traffic safety policy, network improvements and social acceptance). A new indicator, better than the mortality rate, is then set upon the residuals. Mean estimates of this indicator for the years 1980-1982 and the years 1992-1994 rank the countries in the beginning and at the end of the study period. Countries showing the best ranks (and thus the best performance) in 1980 and 1994 are Sweden, the Netherlands and Norway. The UK and Switzerland reach the top 5 in 1994. Greece, Belgium, Portugal and Spain are the last countries in the classification along with, surprisingly, the USA. France was ranked 18th in 1980 and 15th in 1994 but is ranked amongst the five countries that most improved from 1980 to 1994. This model remains non definitive because it is not able to distinguish between safety performance and unobserved exogenous variables although these exogenous variables could explain more about the differences in levels and trends between the countries. More complex models, particularly highly sophisticated models regarding the number of fatalities with breakdowns by road users or road classes would be needed to give a precise and profound ranking of safety levels and safety improvements between countries.


Assuntos
Acidentes de Trânsito/mortalidade , Modelos Estatísticos , Segurança , Humanos , Análise de Regressão , Fatores de Risco
18.
Arch Mal Coeur Vaiss ; 84(11 Suppl): 1747-54, 1991 Nov.
Artigo em Francês | MEDLINE | ID: mdl-1768189

RESUMO

Clinical indications of vena cava interruption are reviewed. During the last few years pulmonary embolism frequency remained high and many new percutaneous vena caval filters became available. These facts probably explain the increasing use of these filters reaching about 10,000 filters each year in France. Existing data show that: embolic risk with antithrombotic agents is less than 5%, probably not far greater than embolic risk with cava filters (about 2%); complications encountered with the filters are caval thrombosis in 8%, and more or less than 4% other major complications; there is no controlled study comparing antithrombotic treatment associated with caval filters to antithrombotic treatment alone; there is no controlled study comparing new cava filters among them or to the Greenfield filter; economical implications of caval filters are mostly unknown. The only admitted indications of vena cava interruption, in case of proximal venous thrombosis, are contraindications to anticoagulation. In other situations no data allow to recommend a cava filter; indication will be discussed on a case by case basis. Prospective controlled studies are greatly encouraged.


Assuntos
Embolia Pulmonar/prevenção & controle , Trombose/terapia , Filtros de Veia Cava , Veia Cava Inferior/cirurgia , Heparina/uso terapêutico , Humanos , Ligadura , Recidiva , Trombose/prevenção & controle , Vitamina K/antagonistas & inibidores
19.
Arch Mal Coeur Vaiss ; 76(7): 771-7, 1983 Jul.
Artigo em Francês | MEDLINE | ID: mdl-6412646

RESUMO

Seven cases of acute ajmaline overdose admitted over a 3 year period to a polyvalent intensive care unit are reported. The severity of this condition is related to the membrane stabilising and depolarising effects of ajmaline on the myocardium. The dose ingested varied from 10 to 40 mg/kg. The delay between ingestion and hospital admission ranged from 3 to 6 1/2 hours. The first cardiac disturbances can appear one hour after ingestion. Three cardiac arrests and one hypovolemic shock occurred. Three atrioventricular blocks, six intraventricular blocks, three ventricular tachycardias, and six prolongations of the QT interval were observed. Serum ajmaline levels varied from 0,8 to 6 mg/l. Symptomatic therapy was mainly based on sodium, temporary cardiac pacing, external DC shock, sympathomimetics and external cardiac massage with assisted ventilation. Cardiac bypass should be a part of the therapeutic arsenal. Elimination of the drug is assisted by a complete digestive evacuation. Renal or extrarenal dialysis is not indicated. One of the seven patients died. Prophylaxis is based on the non-prescription of ajmaline for benign cardiac disturbances.


Assuntos
Ajmalina/intoxicação , Arritmias Cardíacas/tratamento farmacológico , Adolescente , Adulto , Ajmalina/sangue , Ajmalina/uso terapêutico , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Taxa de Depuração Metabólica
20.
Gastroenterol Clin Biol ; 14(10): 698-704, 1990.
Artigo em Francês | MEDLINE | ID: mdl-2262116

RESUMO

We report the clinical results of 38 calibrated side-to-side portocaval shunts performed in patients with hemorrhagic liver cirrhosis (alcoholic in 90 percent of cases). The operative mortality (at 2 months) was 10.5 percent. The rate of recurrent bleeding was 2.6 percent; hepatic encephalopathy was encountered in 16 percent (acute encephalopathy: 6.5 percent; chronic encephalopathy: 9.6 percent; this rate decreased to 3.2 percent after anastomotic narrowing). Hepatopedal portal blood flow was maintained in 74.3 percent of cases in the early postoperative period (83.3 percent since the portacaval pressure gradient was maintained at 2/3 of the initial gradient) and disappeared with time in 75 percent of cases. The survival rates at 1 and 4 years were 79.4 percent and 60 percent, respectively, for all patients (94.4 and 83.3 percent for Child A patients) with a normal social activity in 90 percent of cases. Twelve patients developed hepatocellular carcinoma. These clinical results are similar to those observed after selective shunts and suggest that the side-to-side calibrated portacaval shunt is an excellent procedure for the treatment of bleeding esophageal varices in case of failure or contraindication to endoscopic sclerotherapy or in patients with chronic ascites and good liver function.


Assuntos
Varizes Esofágicas e Gástricas/cirurgia , Hemorragia Gastrointestinal/cirurgia , Cirrose Hepática Alcoólica/complicações , Derivação Portocava Cirúrgica/métodos , Adulto , Idoso , Varizes Esofágicas e Gástricas/complicações , Feminino , Seguimentos , Hemorragia Gastrointestinal/etiologia , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Recidiva , Ruptura
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