Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Case Rep Ophthalmol ; 14(1): 698-705, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38090109

RESUMO

We describe a rare case of Soemmering's ring-induced uveitis-glaucoma-hyphema (UGH) syndrome, caused by an undisplaced, in-the-bag intraocular lens (IOL) 16 years after implantation. The presenting symptoms were recurrent episodes of transient monocular vision loss, which prompted extensive unremarkable investigations. Ultrasound biomicroscopy (UBM) eventually revealed an enlarging Soemmering's ring contacting the posterior iris and causing UGH syndrome. This is a unique case because the IOL haptics remained in the bag. Anterior vitrectomy, Soemmering's ring extraction, IOL exchange to a 3-piece IOL, and implantation of a trabecular meshwork bypass microstent were performed. IOP control and both functional and structural stability were achieved long term. Soemmering's ring-induced UGH syndrome should be on the differential of a patient with previous cataract surgery and elevated IOP complaining of visual disturbances. Early diagnosis with UBM and surgical intervention may provide optimal outcomes.

2.
ACS Omega ; 8(17): 15099-15113, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37151556

RESUMO

The developed nanocomposite exhibits significantly enhanced shielding performance due to the synergistic effect of high dielectric and magnetic loss materials, which modifies the material's impedance and improves its absorption ability. Different weight percentages (0, 1, 5, 10, 15, 20, and 25 wt %) of thermally treated chemically reduced graphene oxide (TCRGO) were combined with two types of magnets, barium hexaferrite (BF) and magnetite (MAG), using a dry powder compaction technique to produce binary ceramic nanocomposite sheets. The shielding performance of a 1 mm thick compressed nanoceramic sheet over the X-band was evaluated using a vector network analyzer. The 25% TCRGO showed high shielding performance for both BF and MAG, while BF had a total shielding efficiency (SET) that exceeded MAG by 130%. The SET of 25 wt % TCRGO/BF was 52 dB, with a 41 dB absorption shielding efficiency (SEA). Additionally, the effect of different levels of incident electromagnetic wave power (0.001-1000 mW) at various thicknesses (1, 2, and 5 mm) was explored. At 1000 mW, the 5 mm TCRGO/BF had an SET of 99 dB, an SEA of 91 dB, and a reflection shielding efficiency (SER) of 8 dB. The use of BF as a hard magnet paired with TCRGO exhibited excellent and stable electromagnetic shielding performance.

3.
Clin J Sport Med ; 22(4): 371-3, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22627648

RESUMO

Using a single clinical case of a professional soccer player presenting an anomalous origin of the right coronary artery, cardiac screening and surgical treatment are described taking into account the recommendations of cardiac and sports societies.


Assuntos
Anomalias dos Vasos Coronários/cirurgia , Morte Súbita Cardíaca/prevenção & controle , Esportes , Anomalias dos Vasos Coronários/diagnóstico , Humanos , Masculino , Adulto Jovem
4.
RSC Adv ; 12(35): 22608-22622, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-36105968

RESUMO

The chemical reduction process of graphene oxide combined with a mild and controllable thermal treatment under vacuum at 200 °C for 4 hours provided a cost-effective, scalable, and high-yield route for Reduced Graphene Oxide (RGO) industrial production and became a potential candidate for producing electromagnetic interference (EMI) shielding. We investigated graphite, and RGO using l-ascorbic acid and Sodium borohydride before and after thermal treatment by carefully evaluating the chemical and morphological structures. The thermally treated l-ascorbic Acid reduction route (TCRGOL) conductivity was 2.14 × 103 S m-1 and total shielding efficiency (SET) based on mass loadings per area of shielding was 94 dB with about one-tenth less graphite weight and surpassing other graphene reduction mechanisms in the frequency range of 8.2-12.4 GHz, i.e., X-band, at room temperature while being tested using the waveguide line technique. The developed treatment represents valuable progress in the path to chemical reduction using a safe reducing agent and offering superior quality RGO rarely achieved with the top-down technique, providing a high EMI shielding performance.

5.
Opt Express ; 17(10): 8012-28, 2009 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-19434133

RESUMO

We report several strategies for the fabrication of porous subwavelength fibers using low density Polyethylene plastic for low-loss terahertz light transmission applications. We also characterize transmission losses of the fabricated fibers in terahertz using a novel non-destructive directional coupler method. Within this method a second fiber is translated along the length of the test fiber to probe the power attenuation of a guided mode. The method is especially suitable for measuring transmission losses through short fiber segments, a situation in which standard cutback method is especially difficult to perform. We demonstrate experimentally that introduction of porosity into a subwavelength rod fiber, further reduces its transmission loss by as much as a factor of 10. The lowest fiber loss measured in this work is 0.01 cm(-1) and it is exhibited by the 40% porous subwavelength fiber of diameter 380 microm. For comparison, the loss of a rod-in-the-air subwavelength fiber of a similar diameter was measured to be approximately 0.1 cm(-1), while the bulk loss of a PE plastic used in the fabrication of such fibers is >or= 1 cm(-1). Finally, we present theoretical studies of the optical properties of individual subwavelength fibers and a directional coupler. From these studies we conclude that coupler setup studied in this paper also acts as a low pass filter with a cutoff frequency around 0.3 THz. Considering that the spectrum of a terahertz source used in this work falls off rapidly below 0.25 THz, the reported loss measurements are, thus, the bolometer averages over the approximately 0.25 THz-0.3 THz region.

6.
Hist Sci Med ; 43(1): 73-81, 2009.
Artigo em Francês | MEDLINE | ID: mdl-19852248

RESUMO

In this article, we analyse and give commentaries on one of the rare Guillaume Laennec's medical manuscripts. It is a treatise of bones' diseases, which is in fact a compilation of notes made, between 1769 and 1772, of Antoine Petit's lectures and other sources. This original document confirms at this time the emergence of rheumatology. It brings it obvious that the paediatrics assert their specific clinical forms. It illustrates the links between surgical and medical pathologies in the eighteenth century. It shows the old humoral theories to be the main obstacle in the way of understanding these pathologies. At last, it reveals that Guillaume Laennec is a member of a medical elite, and contributes to explain the beneficial effect he had on his nephew of genius, René Laennec.


Assuntos
Doenças Ósseas/história , Manuscritos Médicos como Assunto/história , França , História do Século XVIII , Humanos , Museus/história
7.
J Hazard Mater ; 363: 457-463, 2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30392881

RESUMO

The addition of either 3,6-dihydrazino-s-tetrazine (DHT) or 5-aminotetrazolium nitrate (HAT-NO3) to nitrocellulose-based propellants were investigated. At 25% (m/m) concentration, DHT and HAT-NO3 had significant impact on the burning rate of the propellant, up to 80% higher than that of the reference propellant. DHT was found to have very poor compatibility with nitrocellulose and the nitrated esters used in the formulation despite the presence of stabilizer. This lead to a rapid autocatalytic decomposition reaction resulting in a deflagration. HAT-NO3 also had poor compatibility with the same materials. On the contrary, non-ionic tetrazoles were found to be fully compatible with nitrocellulose and nitrated esters based propellants. Most nitrogen-rich energetic molecules have been studied for their explosive characteristics. This study shed light on the potential use of these materials as burning rate modifiers for gun propellant applications, for which very little is known. Moreover, it investigates the stability of the formulations incorporating nitrogen-rich molecules, as a means of assessing the safe use of these novel propellants.

8.
J Biomed Opt ; 13(5): 054003, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19021383

RESUMO

Biodegradable microstructured polymer optical fibers have been created using synthetic biomaterials such as poly(L-lactic acid), poly(epsilon-caprolactone), and cellulose derivatives. Original processing techniques were utilized to fabricate a variety of biofriendly microstructured fibers that hold potential for in vivo light delivery, sensing, and controlled drug-release.


Assuntos
Implantes Absorvíveis , Materiais Biocompatíveis/química , Análise de Falha de Equipamento/métodos , Fibras Ópticas , Desenho de Equipamento , Teste de Materiais
9.
Opt Express ; 14(13): 5838-52, 2006 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-19516753

RESUMO

Drawing of the hollow all-polymer Bragg fibers based on PMMA/PS and PVDF/PC materials combinations are demonstrated. Hole collapse during drawing effects the uniformity of a photonic crystal reflector in the resultant fiber. We first investigate how the core collapse effects fiber transmission properties. We then present modelling of fluid dynamics of hollow multilayer polymer fiber drawing. Particularly, hole collapse during drawing and layer thickness non-uniformity are investigated as a function of draw temperature, draw ratio, feeding speed, core pressurization and mismatch of material properties in a multilayer. Both the newtonian and non-newtonian cases are considered assuming slender geometries.

10.
Hist Sci Med ; 40(4): 351-60, 2006.
Artigo em Francês | MEDLINE | ID: mdl-17526404

RESUMO

His bad health obliged RTH Laennec to interrupt his hospital activities from 1819 to 1821. He goes back to his head functions in Necker's then Charity's Hospitals from 1821 to 1826. His others activities, especially teaching, affect his busy time table. His unit's recruitment is less specialized in thoracic pathologies than it was from 1816 to 1819. It is true that his "Collège of France Lessons" as his lectures, in the faculty of medicine concern all the clinical aspects. So the links between hospital activities and the second edition of his Treaty are not so strong as they were with the first one.


Assuntos
Hospitais/história , Educação Médica/história , Docentes de Medicina/história , França , História do Século XIX , Livros de Texto como Assunto/história
11.
Muscles Ligaments Tendons J ; 6(1): 116-23, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27331039

RESUMO

OBJECTIVES: previous studies investigating the ability of isokinetic strength ratios to predict hamstring injuries in soccer players have reported conflicting results. HYPOTHESIS: to determine if isokinetic ratios are able to predict hamstring injury occurring during the season in professional soccer players. STUDY DESIGN: case-control study; LEVEL OF EVIDENCE: 3. METHODS: from 2001 to 2011, 350 isokinetic tests were performed in 136 professional soccer players at the beginning of the soccer season. Fifty-seven players suffered hamstring injury during the season that followed the isokinetic tests. These players were compared with the 79 uninjured players. The bilateral concentric ratio (hamstring-to-hamstring), ipsilateral concentric ratio (hamstring-to-quadriceps), and mixed ratio (eccentric/concentric hamstring-to-quadriceps) were studied. The predictive ability of each ratio was established based on the likelihood ratio and post-test probability. RESULTS: the mixed ratio (30 eccentric/240 concentric hamstring-to-quadriceps) <0.8, ipsilateral ratio (180 concentric hamstring-to-quadriceps) <0.47, and bilateral ratio (60 concentric hamstring-to-hamstring) <0.85 were the most predictive of hamstring injury. The ipsilateral ratio <0.47 allowed prediction of the severity of the hamstring injury, and was also influenced by the length of time since administration of the isokinetic tests. CONCLUSION: isokinetic ratios are useful for predicting the likelihood of hamstring injury in professional soccer players during the competitive season.

12.
J Biotechnol ; 100(1): 65-75, 2003 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-12413787

RESUMO

Research on the biodegradation of explosives has focussed exclusively on the treatment of contaminated soil and water. In the present work the anaerobic degradation of hexahydro-1,3,5-trinitro-1,3,5-s-triazine (RDX) by Enterobacter cloacae ATCC 43560 was investigated, and a two-phase partitioning bioreactor (TPPB) was developed for the destruction of pure, past-date munitions. TPPBs are characterized by a cell-containing aqueous phase, and an immiscible and biocompatible organic phase into which very large amounts of toxic and/or insoluble substrates can be dissolved. Based on equilibrium partitioning, the substrate is then transported to the cells, in response to their metabolic requirements, providing a means of demand-based substrate delivery, and high bioreactor productivity. Through consideration of the critical logP of E. cloacae, whether various classes of solvents could be used as sole carbon and energy sources, the capacity of various organics to dissolve RDX, and solvent cost, 2-undecanone was ultimately selected as the delivery solvent for the TPPB. Using this solvent, both batch and fed-batch operation of the TPPB were undertaken, and the volumetric degradation rate of RDX was found to be higher in this arrangement than any previous values reported in the literature. This work has demonstrated the potential of a method for the destruction of decommissioned munitions involving the dissolution of RDX in 2-undecanone, the use of the RDX-rich solvent as the second phase in a TPPB to degrade this explosive, and the subsequent recycling and re-use of the solvent.


Assuntos
Reatores Biológicos , Enterobacter cloacae/crescimento & desenvolvimento , Enterobacter cloacae/metabolismo , Triazinas/metabolismo , Anaerobiose , Biodegradação Ambiental , Células Cultivadas , Enterobacter cloacae/classificação , Enterobacter cloacae/efeitos dos fármacos , Resíduos Industriais/prevenção & controle , Ciência Militar/métodos , Poluentes do Solo/metabolismo , Solventes/farmacologia , Especificidade da Espécie , Poluentes Químicos da Água/metabolismo
13.
BMC Res Notes ; 7: 684, 2014 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-25270624

RESUMO

BACKGROUND: This is the first report of external abdominal oblique muscle injury occurring in a professional soccer player. CASE PRESENTATION: A 28-year-old Caucasian professional soccer player presented after experiencing a popping sensation associated with strong parietal pain localized between the left 11th and 12th ribs. Ultrasound examination revealed a collection of fluid under the 11th rib, suggesting injury of the left external oblique muscle. Platelet-rich plasma treatment was administered and the soccer player returned to competition on the 21st day after treatment. CONCLUSION: This rare injury results from a sudden intrinsic eccentric contraction of the internal oblique muscle while in a stretched position. Ultrasound can help to confirm the diagnosis and to monitor clinical follow-up. Platelet-rich plasma treatment could aid recovery in high-level athletes.


Assuntos
Músculos Abdominais/lesões , Futebol/lesões , Entorses e Distensões/etiologia , Músculos Abdominais/diagnóstico por imagem , Músculos Abdominais/fisiopatologia , Adulto , Humanos , Masculino , Contração Muscular , Plasma Rico em Plaquetas , Recuperação de Função Fisiológica , Entorses e Distensões/diagnóstico , Entorses e Distensões/fisiopatologia , Entorses e Distensões/terapia , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia
15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 83(6 Pt 1): 061134, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21797329

RESUMO

Heat transfer is investigated on three levels of description: Fourier, Cattaneo, and Peierls. The microscopic nature of the heat that becomes important, in particular in nanoscale systems, is characterized by a vector field related to the heat flux on the Cattaneo level and by the phonon distribution function on the Peierls level. All dynamical theories discussed in the paper are fully nonlinear and all are proven to be compatible among themselves, with equilibrium thermodynamics, and with mechanics. An investigation of the first two compatibilities gives rise to potentials having the physical interpretation of nonequilibrium entropies. The compatibility with mechanics is manifested by the Hamiltonian structure of the time-reversible part of the time evolution.

16.
Clin Physiol Funct Imaging ; 30(3): 187-91, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20345971

RESUMO

The aim of this study was to compare statical postures of a knee anterior cruciate ligament reconstruction (ACLR) population with a healthy control population. Thirty-five patients (age 25.5 +/- 5.8 years) were compared at 15 days after an anterior cruciate ligament reconstruction with 35 healthy, age and sex-matched subjects. Bilateral and unilateral postures were studied according to various stances, knee extension and 20 degrees knee flexion with opened and closed eyes, using a stabilometric platform. A comparison with the non-ACLR limb and the healthy limbs of the control population was carried out. The ACLR subjects present with the following: (i) a significant change in two-legged stance, i.e. distances covered by the centre of pressure projection are significantly increased; (ii) a postural alteration during the ACLR one-legged stance with knee extension and opened eyes in comparison with the non-ACLR limb; (iii) an incapacity for certain ACLR subjects to perform one-legged stance on the non-ACLR limb when there is no visual compensation. Only 11.4% (95% CI: 0.9-21.9%) and 42.8% (95% CI: 26.3-59.3%) of ACLR subjects are capable of maintaining correctly a one-legged stance posture with closed eyes on both sides (knee extension and flexion, respectively). The identification of the ACLR knee limb is possible from the one-legged stance postural test in knee extension and opened eyes condition. Because of a change in two-legged balance and of the incapacity for certain ACLR subjects to maintain one-legged stance with closed eyes, a central origin explaining the abnormalities of postural control is suggested.


Assuntos
Ligamento Cruzado Anterior/fisiopatologia , Ligamento Cruzado Anterior/cirurgia , Traumatismos do Joelho/fisiopatologia , Traumatismos do Joelho/cirurgia , Procedimentos de Cirurgia Plástica , Equilíbrio Postural , Postura , Adulto , Feminino , Humanos , Masculino , Resultado do Tratamento
17.
Opt Lett ; 32(2): 109-11, 2007 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17186033

RESUMO

We report fabrication of a novel microstructured optical fiber made of biodegradable and water soluble materials that features approximately 1 dB/cm transmission loss. Two cellulose butyrate tubes separated with hydroxypropyl cellulose powder were codrawn into a porous double-core fiber offering integration of optical, microfluidic, and potentially drug release functionalities.


Assuntos
Tecnologia de Fibra Óptica/métodos , Óptica e Fotônica , Animais , Materiais Biocompatíveis/química , Técnicas Biossensoriais , Butiratos/química , Celulose/análogos & derivados , Celulose/química , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Desenho de Equipamento , Humanos , Fibras Ópticas , Polímeros/química , Pós/química
18.
Joint Bone Spine ; 74(2): 179-83, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17336570

RESUMO

Six cases of iliopsoas hematoma were diagnosed in 5 patients with hemophilia over the last 5 years at our hemophilia center. We reviewed these cases to determine the incidence and precipitating factors of iliopsoas hematoma in hemophilia. Of the 5 patients, 4 had severe hemophilia A and 1 had moderate hemophilia A with a history of inhibitors to factor VIII concentrates. The age range was 13 to 33 years. The hematoma was posttraumatic in 2 cases and spontaneous in 4 cases. Femoral nerve compression developed in 2 cases. There were four recurrences. At the time of the hematoma, 2 patients were receiving long-term prophylactic factor VIII concentrate therapy but one of them had stopped the injections of his own accord. The treatment consisted of recombinant factor VIII concentrates, a brief course of glucocorticoid therapy in the 2 cases with femoral nerve involvement, lower limb traction in 3 patients, and rehabilitation therapy. The annual incidence rate of iliopsoas hematoma was 2.9/1000 patients with severe or moderate hemophilia A. The use of prophylactic factor VIII therapy and compliance with recommendations about avoiding activities that put strain on the hip flexor muscles probably explain the low rate of iliopsoas muscle hematoma in patients with hemophilia in France. An early diagnosis allows early Factor VIII therapy, which decreases the risk of femoral nerve involvement and recurrence.


Assuntos
Hematoma/etiologia , Hemofilia A/complicações , Músculos Psoas , Adolescente , Adulto , Fator VIII/uso terapêutico , Hematoma/diagnóstico , Hematoma/terapia , Hemofilia A/terapia , Humanos , Masculino , Recidiva , Estudos Retrospectivos , Resultado do Tratamento
20.
Ecotoxicology ; 13(6): 603-14, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15526864

RESUMO

Earthworm mesocosms studies were carried out on a explosives-contaminated site at an antitank firing range. Survival of earthworms and the lysosomal neutral red retention time (NRRT), a biomarker of lysosomal membrane stability, were used in these studies to assess the effect of explosives-contaminated soils on the earthworms Lumbricus terrestris and Eisenia andrei under field conditions. Toxicity of the soils samples for E. andrei was also assessed under laboratory conditions using the earthworms reproduction test and the NRRT. Results indicate that the survival was reduced up to 40% in certain explosive-contaminated soil mesocosms following 10 days of exposure under field conditions, whereas survival was reduced up to 100% following 28 days of exposure under laboratory conditions. Reproduction parameters such as number of cocoons and number of juveniles were reduced in many of the selected contaminated soils. Compared to the reference, NRRT was significantly reduced for E. andrei exposed to explosive-contaminated soils under both field and laboratory conditions, whereas for L. terrestris NRRT was similar compared to the reference mesocosm. Analyses showed that HMX was the major polynitro-organic compound in soils. HMX was also the only explosive detected in earthworm tissues. Thus, results from both field mesocosms and laboratory studies, showed lethal and sub-lethal effects associated to soil from the contaminated area of the antitank firing range.


Assuntos
Compostos Heterocíclicos com 1 Anel/toxicidade , Oligoquetos/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Poluentes do Solo/toxicidade , Trinitrotolueno/toxicidade , Animais , Bioensaio , Biomarcadores/análise , Monitoramento Ambiental , Incêndios , Dose Letal Mediana , Lisossomos/metabolismo , Vermelho Neutro/análise , Oligoquetos/metabolismo , Medição de Risco , Poluentes do Solo/análise , Análise de Sobrevida
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA