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1.
Int J Surg Case Rep ; 40: 102-104, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28965084

RESUMO

INTRODUCTION: Sternoclavicular dislocations are difficult to diagnose and often missed. Anterior dislocations are more common than posterior dislocations and typically have a low risk of complications. PRESENTATION OF CASE: We report the third case of post-traumatic superior sternoclavicular dislocation, which was successfully treated by functional treatment. DISCUSSION: The sternoclavicular joint is a diarthrodial joint with three degrees of freedom that is relatively immobile and incongruent. The treatment strategy for these injuries is based on two criteria: the possibility of vascular, nerve or tracheal compression such as in posterior dislocations, which is a surgical indication because of potential risk to life and function; the second indication is to improve esthetics, which is especially a concern with anterior dislocations. CONCLUSION: Superior sternoclavicular dislocation is a rare condition, with only three published cases up to now. Functional treatment can be used without complications.

3.
Phys Rev Lett ; 95(17): 173902, 2005 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-16383831

RESUMO

We present the first direct measurement of the time evolution of the gain of a soft x-ray laser amplifier. The measurement is based on the injection of a seed pulse, obtained by high-order harmonic generation, into an x-ray laser medium. Strong amplification occurs when the seed pulse is synchronized with the gain period. By precisely varying the delay between the x-ray laser plasma creation and the seed pulse injection, the actual temporal evolution of the soft x-ray amplifier gain is obtained with a subpicosecond resolution.

4.
Nature ; 431(7007): 426-9, 2004 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-15386005

RESUMO

Synchrotrons have for decades provided invaluable sources of soft X-rays, the application of which has led to significant progress in many areas of science and technology. But future applications of soft X-rays--in structural biology, for example--anticipate the need for pulses with much shorter duration (femtoseconds) and much higher energy (millijoules) than those delivered by synchrotrons. Soft X-ray free-electron lasers should fulfil these requirements but will be limited in number; the pressure on beamtime is therefore likely to be considerable. Laser-driven soft X-ray sources offer a comparatively inexpensive and widely available alternative, but have encountered practical bottlenecks in the quest for high intensities. Here we establish and characterize a soft X-ray laser chain that shows how these bottlenecks can in principle be overcome. By combining the high optical quality available from high-harmonic laser sources (as a seed beam) with a highly energetic soft X-ray laser plasma amplifier, we produce a tabletop soft X-ray femtosecond laser operating at 10 Hz and exhibiting full saturation, high energy, high coherence and full polarization. This technique should be readily applicable on all existing laser-driven soft X-ray facilities.

5.
Phys Rev E Stat Nonlin Soft Matter Phys ; 66(3 Pt 1): 030501, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12366091

RESUMO

We demonstrate by both experiments and phase-field simulations that lamellar eutectic growth can be stable for a wide range of spacings below the point of minimum undercooling at low velocity, contrary to what is predicted by existing stability analyses. This overstabilization can be explained by relaxing Cahn's assumption that lamellae grow locally normal to the eutectic interface.

6.
Phys Rev E Stat Nonlin Soft Matter Phys ; 65(1 Pt 1): 011702, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11800702

RESUMO

We present an experimental study of the directional-solidification patterns of a nematic-smectic-B front. The chosen system is C4H9-(C6H10)2CN (in short, CCH4) in 12 microm-thick samples, and in the planar configuration (director parallel to the plane of the sample). The nematic-smectic-B interface presents a facet in one direction-the direction parallel to the smectic layers--and is otherwise rough and devoid of forbidden directions. We measure the Mullins-Sekerka instability threshold and establish the morphology diagram of the system as a function of the solidification rate V and the angle straight theta(0) between the facet and the isotherms. We focus on the phenomena occurring immediately above the instability threshold when straight theta(0) is neither very small nor close to 90 degrees. Under these conditions, we observe drifting shallow cells and a type of solitary wave, called "faceton," which consists essentially of an isolated macroscopic facet traveling laterally at such a velocity that its growth rate with respect to the liquid is small. Facetons may propagate either in a stationary or an oscillatory way. The detailed study of their dynamics casts light on the microscopic growth mechanisms of the facets in this system.

7.
Artigo em Inglês | MEDLINE | ID: mdl-11088155

RESUMO

We present an experimental investigation of the morphological transition of lamellar eutectic growth fronts called "formation of eutectic colonies" by the method of thin-sample directional solidification of a transparent model alloy, CBr4-C2Cl6. This morphological transition is due to the presence in the melt of traces of chemical components other than those of the base binary alloy (impurities). In this study, we use naphthalene as an impurity. The formation of eutectic colonies has generally been viewed as an impurity-driven Mullins-Sekerka instability of the envelope of the lamellar front. This traditional view neglects the strong interaction existing between the Mullins-Sekerka process and the dynamics of the lamellar pattern. This investigation brings to light several original features of the formation of eutectic colonies, in particular, the emission of long-wavelength traveling waves, and the appearance of dendritelike structures called two-phase fingers, which are connected with this interaction. We study the part played by these phenomena in the transition to eutectic colonies as a function of the impurity concentration. Recent theoretical results on the linear stability of ternary lamellar eutectic fronts [Plapp and Karma, Phys. Rev. E 60, 6865 (1999)] shed light on some aspects of the observed phenomena.

9.
Phys Rev A ; 46(2): 963-972, 1992 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-9908198
12.
Arch Mal Coeur Vaiss ; 79(3): 282-9, 1986 Mar.
Artigo em Francês | MEDLINE | ID: mdl-3087312

RESUMO

The clinical and echocardiographic features of right atrial thrombi were examined in 9 patients, 5 men and 4 women aged 16 to 86 years. The 2D echocardiographic diagnosis was confirmed at autopsy (4 cases) or by the association of severe recurrent pulmonary embolism (5 cases). Three patients had associated ischaemic heart disease and on patient had dilated cardiomyopathy. The clinical presentation was: acute cor pulmonale (5 cases including 2 patients which biventricular myocardial infarction), chronic post-embolic cor pulmonale (1 case), tricuspid valve obstruction (1 case), general ill health with pyrexia (1 case) and heparin-induced thrombocytopenia (1 case). Predisposing factors included: absence of anticoagulent therapy (7 cases), previous supraventricular arrhythmias (2 cases) and right ventricular failure (6 cases, including 2 of right ventricular infarction). In 2 patients the thrombi were relatively immobile and had a wide base of implantation on the interatrial septum; in 1 patient, multiple thrombi were observed lining the right heart cavities from the inferior vena cava to the pulmonary infundibulum. In the other 6 patients, the thrombi were very mobile with a visible pedicule of implantation (2 cases) or totally free (4 cases). The variable polylobulated appearances, completely irregular whirling motion and intermittent prolapse into the tricuspid valve were characteristic features of the latter 4 cases. They disappeared spontaneously (2 cases) or after fibrinolytic therapy (2 cases) in under 36 hours. Three patients were operated with one postoperative death. The global hospital mortality was 22%. The present occasional detection of right atrial thrombosis will certainly become more common if patients with pulmonary embolism, right ventricular infarction or deep venous thrombosis are systematically examined by 2D echocardiography in the acute phase of their illness.


Assuntos
Doença das Coronárias/diagnóstico , Ecocardiografia , Adolescente , Idoso , Anticoagulantes/uso terapêutico , Doença das Coronárias/complicações , Doença das Coronárias/terapia , Feminino , Átrios do Coração , Heparina/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/complicações , Embolia Pulmonar/complicações , Tromboflebite/complicações
13.
Presse Med ; 15(13): 611-6, 1986 Mar 29.
Artigo em Francês | MEDLINE | ID: mdl-2939419

RESUMO

Two types of radioisotope tomography have been developed: single photon emission computed tomography and positron emission tomography. Tomography of the heart meets with several problems due to the mobility and obliquity of that organ and to the heterogeneity of surrounding tissues. Compared with planar tomography, myocardial tomography with thallium 201 improves the detection of ischaemic and sub-ischaemic areas in myocardial infarction and chronic coronary disease. In spite of some technical limitations, tomography with labelled red cells is very helpful to determine pre-operative size and location of aneurysms.


Assuntos
Cardiopatias/diagnóstico por imagem , Coração/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Doença das Coronárias/diagnóstico por imagem , Humanos , Infarto do Miocárdio/diagnóstico por imagem , Esforço Físico , Radioisótopos , Descanso , Tálio
14.
Presse Med ; 14(31): 1645-8, 1985 Sep 21.
Artigo em Francês | MEDLINE | ID: mdl-2932704

RESUMO

Fourteen cases of apical hypertrophic cardiomyopathy (i.e. hypertrophy localized to the distal half of the left ventricular wall) are reported. There were 12 men and 2 women aged from 21 to 84 years. Only one of the patients presented, at first consultation, with severe functional symptoms, namely stage IV dyspnoea. ECG tracings were always abnormal, but the classical giant T waves were found in only 7 patients. In the 9 patients who had cardiac catheterization the left ventricular end-diastolic pressure was raised, and angiography showed an "ace of spades" diastolic image of the left ventricle with systolic obliteration of its tip. The distribution of parietal hypertrophy was best studied by two-dimensional echocardiography: the left ventricular apex was affected alone in 7 patients and concomitantly with the adjacent segments of the left or right ventricle in the other 7 patients. A family study showed that 3 patients had a descendant with obstructive cardiomyopathy. At a 4.6 years' follow-up the course of the disease was usually favourable. Apical hypertrophic cardiomyopathy is not a particular entity but one of different possible forms of hypertrophic cardiomyopathy. It seems to be benign in most cases.


Assuntos
Cardiomiopatia Hipertrófica/diagnóstico , Adulto , Idoso , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/patologia , Ecocardiografia , Eletrocardiografia , Feminino , Ventrículos do Coração/diagnóstico por imagem , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Radiografia , Fatores de Tempo
15.
Arch Mal Coeur Vaiss ; 78(8): 1156-62, 1985 Aug.
Artigo em Francês | MEDLINE | ID: mdl-3935072

RESUMO

The electrophysiological effects of prostacyclin (PGI2) at increasing doses (2.5, 5 and 10 ng/kg/min) were assessed in 16 patients during classical investigations of sinus node function and atrioventricular conduction and during programmed atrial and right ventricular under basal conditions and during prostacyclin perfusion. Ten patients had normal sinus node function and atrioventricular conduction under basal conditions. Stastistically significant changes were observed during PGI2 perfusion: shortening of the sinus cycle length (p 0.01), decreased intraatrial conduction time (p less than 0.05), reduced atrial functional refractory period (p less than 0.01) and reduced effective and functional refractory periods of the AV node (p less than 0.05), increased anterograde (p less than 0.01) and retrograde (p less than 0.05) Wenckebach point. The changes were dose dependent. No significant changes were observed in sinus node recovery periods of the His Purkinje system. Similar changes were recorded on 4 other patients with various conduction defects. Paired atrial stimulation induced manifestations of hyperexcitability in 5 patients. In 2 patients with normal responses under basal conditions it was possible to induce non-sustained atrial tachycardia during PGI2 administration. In 3 patients with inducible atrial tachycardia under basal conditions, it was still possible to induce the tachycardia after PGI2 but this disappeared in all but one patient with the sick sinus syndrome after the addition of propranolol. The changes in ventricular excitability were studied by a specific protocol in 16 patients. Of the 13 patients without inducible ventricular tachycardia under basal conditions, 4 developed inducible non-sustained ventricular tachycardia after PGI2. Three patients had inducible VT under basal conditions.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Epoprostenol/farmacologia , Sistema de Condução Cardíaco/efeitos dos fármacos , Adulto , Idoso , Antiarrítmicos , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/fisiopatologia , Eletrocardiografia , Epoprostenol/uso terapêutico , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Pessoa de Meia-Idade , Taquicardia/tratamento farmacológico
16.
Ann Cardiol Angeiol (Paris) ; 34(7): 461-6, 1985.
Artigo em Francês | MEDLINE | ID: mdl-2932995

RESUMO

This study, based on 39 cases, confirms the value of two-dimensional echocardiography in the diagnosis of right ventricular infarction during the acute phase. This diagnosis is confirmed by the presence of abnormalities of the segmental kinetics always present in the inferior wall and less frequently in the anterior wall. The inferior part of the septum is affected in two thirds of cases. Right ventricular dilation is frequently observed, but is not constant. Two-dimensional echocardiography has a diagnostic sensitivity similar to that of isotope ventriculography, but greater than that of haemodynamic investigations. Finally, apart from the easy demonstration of complications (tricuspid incompetence, septal rupture, intracardiac thrombosis), two dimensional echocardiography can be used to evaluate right ventricular function.


Assuntos
Ecocardiografia/métodos , Infarto do Miocárdio/diagnóstico , Cardiomegalia/diagnóstico , Ventrículos do Coração/fisiopatologia , Humanos , Infarto do Miocárdio/fisiopatologia
17.
Arch Mal Coeur Vaiss ; 78(7): 1001-8, 1985 Jul.
Artigo em Francês | MEDLINE | ID: mdl-3929728

RESUMO

Classically, the frequency of latent left-sided Kent bundles and ventricular tachycardia (VT) is increased in mitral valve prolapse (MVP). To verify this hypothesis, 23 patients with clinical and echocardiographic (M mode and 2D) signs of MVP underwent electrophysiological studies for dizziness or syncope (12 cases) or palpitations (11 cases). In addition to the standard electrophysiological studies, analysis of sinoatrial and atrioventricular conduction, they underwent programmed ventricular pacing (St V2): coupled and then paired St V2 in sinus rhythm and during ventricular pacing (100-150/min) under basal conditions (15 patients), after injection of 2 mg Atropine (6 patients), and 10 micrograms of Isoproterenol (4 patients). These manoeuvres showed that symptoms of dizziness were due to increased vagal tone in 6 cases (associated with paroxysmal nodal tachycardia--PNT--in 3 cases), to sinoatrial block in 2 cases (associated with atrial tachycardia in 1 case), to suprahisian conduction defects in 3 cases (associated with atrial tachycardia in 1 case) and to VT in 1 case. Palpitations were due to VT in 1 case, atrial tachycardia in 1 case and PNT in 9 cases. Our analysis showed a high incidence of PNT (10 cases) with normal inter critical ECG. These arrhythmias were due to intranodal reentry in 7 cases (70%), to a latent left-sided Kent bundle in 2 cases and to a paraseptal Kent bundle in 1 case. These PNT were characterised by induction during exercise (6 cases) and by their association with flutter-type reentry (5 cases).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Arritmias Cardíacas/fisiopatologia , Eletrocardiografia , Prolapso da Valva Mitral/fisiopatologia , Adolescente , Adulto , Idoso , Arritmias Cardíacas/etiologia , Morte Súbita/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prolapso da Valva Mitral/complicações , Risco
18.
Eur Heart J ; 6(7): 609-14, 1985 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3899655

RESUMO

Prostacyclin (PGI2) has been shown to reduce the occurrence of experimental ventricular arrhythmias. To assess potential beneficial effects in man, the electrophysiological action of PGI2 was studied in 16 non medicated patients. The protocol used in incremental pacing and programmed stimulation in the right atrium and ventricle. This protocol and measurement of effective refractory periods (ERP) were performed before and during the injection of 2.5, 5 and 10 ng kg-1 min-1 of PGI2. The atrial functional refractory period decreased significantly (P less than 0.05); PGI2 had no influence on the occurrence of inducible non-sustained (NS) atrial tachycardias and was responsible for the occurrence of 2 non-sustained atrial tachycardias in 8 patients with inducible atrial echo beats under basal conditions. Thirteen patients did not have inducible ventricular tachycardia (VT) under basal conditions. Non-sustained VT was induced after PGI2 in 4 of them but in only 1 of them after the administration of propranolol. Three patients had inducible VT under basal conditions (1 non-sustained, 2 sustained VT). PGI2 did not prevent the occurrence of VT (1 non-sustained, 1 sustained VT), except in 1 patient with ischaemic-related VT, who had non-sustained VT after PGI2. In conclusion, PGI2 does not seem to have a cardiac antiarrhythmic effect and may increase the atrial and ventricular repetitive response. This effect could be related to an increase of adrenergic tone.


Assuntos
Arritmias Cardíacas/tratamento farmacológico , Eletrocardiografia , Epoprostenol/uso terapêutico , Adulto , Idoso , Nó Atrioventricular/efeitos dos fármacos , Estimulação Cardíaca Artificial , Epoprostenol/efeitos adversos , Feminino , Ventrículos do Coração/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia/induzido quimicamente
19.
Arch Mal Coeur Vaiss ; 78(6): 925-7, 1985 Jun.
Artigo em Francês | MEDLINE | ID: mdl-2931060

RESUMO

2 cases of severe pulmonary valvular stenosis in two young adults aged 21 and 29 years respectively are presented. Despite the degree of stenosis (4 mm jet), the right ventricular pressures did not exceed systemic pressures because of severe tricuspid regurgitation. This dominated the clinical and anatomical findings, causing aneurysmal dilatation of the right atrium and displacement of the tricuspid valve to the left. The diagnosis of Ebstein's anomaly was raised in one case but excluded by echocardiography and angiocardiography. In spite of the severity of the symptoms and peripheral clinical signs, surgery of the right ventricular outflow tract, tricuspid valvuloplasty and resection of part of the right atrium led to a complete and rapid cure, confirmed by catheterisation one month after operation.


Assuntos
Cardiomegalia/etiologia , Estenose da Valva Pulmonar/complicações , Insuficiência da Valva Tricúspide/etiologia , Adulto , Hemodinâmica , Humanos , Masculino , Estenose da Valva Pulmonar/diagnóstico , Fatores de Tempo
20.
Ann Cardiol Angeiol (Paris) ; 34(5): 329-33, 1985 May.
Artigo em Francês | MEDLINE | ID: mdl-4040347

RESUMO

Apical hypertrophic cardiomyopathy is a recently defined subgroup of primary hypertrophic cardiomyopathy. Ten new cases are studied. The electrical features (anomalies of repolarisation) were constant and giant negative T waves were observed in 3 out of 10 cases. Two-dimensional ultrasonography confirmed the diagnosis in every case; the optimal views consisted of 4 cavity scans obtained by the apical approach. When angiography was performed (7 cases out of 10), it confirmed the ultrasonographic findings and was able to eliminate any coronary artery lesions. The patients had a mean age of 48.3 years with a marked male predominance (sex ratio of 0.8) and all of the patients are alive with a mean follow-up of 3.4 years. The functional handicap was moderate (class III: 1 case, class II: 5 cases and class I: 4 cases) and did not progress during the period of follow-up. The family surveys performed revealed that apical hypertrophy can be integrated into the spectrum of segmental hypertrophic cardiomyopathy. In two cases, this survey revealed the coexistence in the same family of segmental hypertrophy with different topography. The long term prognosis of this disease is unknown and the authors consider that the risk of ventricular arrhythmia justifies routine rhythmological evaluation in order to guide subsequent treatment.


Assuntos
Cardiomiopatia Hipertrófica/diagnóstico , Adulto , Idoso , Cardiomiopatia Hipertrófica/diagnóstico por imagem , Cardiomiopatia Hipertrófica/fisiopatologia , Diagnóstico Diferencial , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Radiografia , Estudos Retrospectivos , Fatores de Tempo
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