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1.
Encephale ; 48(6): 607-614, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34625216

RESUMO

INTRODUCTION: Health sciences students usually report high rates of mental health problems. The COVID-19 pandemic context may have serious psychological impacts in this at-risk population. We aimed to assess the self-reported mental health status, health-related quality of life and coping strategies of health sciences students during the early stage of the pandemic. METHOD: An online 128-item questionnaire sent to 17,673 health sciences students from the Claude Bernard University Lyon 1 in April 2020 assessed: a) sociodemographic characteristics, b) conditions of lockdown, c) depressive (Beck Depression Inventory- Short Form, BDI-SF), anxiety (State-Trait Anxiety Inventory-A, STAI-A) and traumatic symptoms (Impact of Event Scale -Revised, IES-R), d) health-related quality of life (SF12) and e) coping strategies (Brief Coping Orientation to Problems Experienced, Brief COPE). RESULTS: The participation rate was 9.9% (n=1,765). A total of 19.5% of participants reported an IES-R>33, 11.6% depressive symptoms, 58.1% anxiety symptoms, and 4.4% suicidal ideation. Their mental health-related quality of life was significantly poorer than for physical health. Female gender, COVID-like symptoms, social isolation due to the lockdown, pandemic-related financial restraint and exams-related stress were significantly associated with poorer self-reported mental health conditions. Volunteering in the healthcare system was significantly associated with lower mental health scores. Coping strategies were mostly oriented toward avoidance and positive appraisal. CONCLUSION: French health sciences students exhibited high levels of self-reported mental health problems and a poor mental health-related quality of life during the early stage of the COVID-19 pandemic. Specific risk factors related to the pandemic partly explain the observed prevalence.


Assuntos
COVID-19 , Feminino , Humanos , COVID-19/epidemiologia , Pandemias , Saúde Mental , Qualidade de Vida , Autorrelato , SARS-CoV-2 , Estresse Psicológico/psicologia , Controle de Doenças Transmissíveis , Adaptação Psicológica , Ansiedade/psicologia , Estudantes/psicologia , Inquéritos e Questionários , Depressão/psicologia
2.
Eur Ann Otorhinolaryngol Head Neck Dis ; 139(4): 208-215, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34210630

RESUMO

OBJECTIVES: To systematically present and interpret the current literature on research and treatment perspectives for mandibular osteoradionecrosis (mORN) in the field of biomaterials. MATERIAL AND METHODS: A systematic review of the literature using the "Synthesis without meta-analysis" (SWiM) methodology was performed on PubMed, Embase and Cochrane, focusing on the implantation of synthetic biomaterials for bone reconstruction in mORN in humans and/or animal models. The primary endpoints were the composition, efficacy on mORN and tolerance of the implanted synthetic biomaterials. RESULTS: Forty-seven references were obtained and evaluated in full-text by two assessors. Ten (8 in humans and 2 in animal models) met the eligibility criteria and were included for analysis. Materials most often comprised support plates or metal mesh (5 of 10 cases) in combination with grafts or synthetic materials (phosphocalcic ceramics, glutaraldehyde). Other ceramic/polymer composites were also implanted. In half of the selected reports, active compounds (molecules, growth factors, lysates) and/or cells were associated with the reconstruction material. The number of articles referring to implantation of biomaterials for the treatment of mORN was small, and the properties of the implanted biomaterials were generally poorly described, thus limiting a thorough understanding of their role. CONCLUSION: In preventing the morbidity associated with some reconstructive surgeries, basic research has benefitted from recent advances in tissue engineering and biomaterials to repair limited bone loss.


Assuntos
Osteorradionecrose , Procedimentos de Cirurgia Plástica , Animais , Materiais Biocompatíveis , Humanos , Mandíbula/cirurgia , Osteorradionecrose/cirurgia , Próteses e Implantes
3.
J Genet Psychol ; 181(6): 470-488, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33000692

RESUMO

The present study explored the links between the quality of adolescents' attachment to their mother and their father, separation anxiety and suicidal ideation. Self-report questionnaires were completed by French adolescents (n = 455; Mage = 15.78 years, SD = 1.61) to probe their attachment styles, separation anxiety (related to school phobia, a secure base, and family members), and suicidal ideation. Avoidantly attached adolescents displayed greater school phobia than securely attached adolescents. Female adolescents with an avoidant attachment to their father tended to report less fear related to family members than their secure counterparts. Male adolescents who were insecurely attached to their mother reported more separation anxiety than securely attached males. The structural models were significant for both boys and girls (R2 = .38 and .44, p < .001) with good fit indices. Mediation analyses revealed that separation anxiety partially mediated the negative effect of attachment to mother (especially alienation) on suicidal ideation for both girls and boys, and partially mediated the negative effect of attachment to father (especially alienation) on suicidal ideation for boys. These results support an individuated conception of attachment patterns, with a differential influence of dyadic relationships, and could provide a better understanding of adolescents' suicidal ideation.


Assuntos
Ansiedade de Separação , Relações Pai-Filho , Relações Mãe-Filho , Ideação Suicida , Adolescente , Criança , Feminino , França , Humanos , Masculino , Autorrelato , Inquéritos e Questionários
4.
Dent Mater ; 36(3): e59-e73, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31928776

RESUMO

OBJECTIVE: Dental device is a very broad term that can be used to include any foreign material or product that is introduced in the host oral cavity to replace missing tissues. These devices are subjected to different environments which include dental hard tissues, tissue fluids, blood and saliva. All dental devices are continuously challenged microbiologically and a number of failures in clinical management are related to microbial colonization. Thus, the assessment of the antimicrobial properties of dental devices are extremely important. In this paper, a classification of dental devices is being proposed. This classification distinguishes the devices based on whether they are implantable or not, and also sub-classified based on their specific application and the substrate receiving the device. METHODS AND RESULTS: A literature search was conducted to identify how dental devices have been tested with relation to the microbial strains used and whether the testing has been performed in isolation or reported with other relevant tests such as material characterization and biological activity. The results of the literature review were analyzed and recommendations for antimicrobial testing of dental devices are proposed. These recommendations include the need for the setting up of pre-testing parameters such as ageing and the details of the pre-testing sterilization procedures, as these may affect the material chemistry and the specification for antimicrobial testing to be done with specific single strains or polymicrobial that are native to the region where the device is located are also suggested. Testing can be undertaken in vitro, ex vivo and in vivo. Since the antimicrobial and biological activities influence/condition one another and the material chemistry may affect both the antimicrobial and biological testing this document also makes recommendations regarding biological assessment which can be carried out in isolation or integrated with the microbiological testing and also material testing methods including chemical and physical characterization of bulk, surface, eluted and degraded materials as well as physical characterization methods. SIGNIFICANCE: The level of standardization of antimicrobial testing for the dental devices needs to be based on the device location and host interaction in order to increase the clinical applicability of the mentioned tests.


Assuntos
Anti-Infecciosos , Antibacterianos , Teste de Materiais , Boca
5.
Arch Pediatr ; 25(3): 189-193, 2018 Apr.
Artigo em Francês | MEDLINE | ID: mdl-29523379

RESUMO

INTRODUCTION: The role of anemia is raised as a risk of low respiratory infection of the child, but there are no data on anemia as a severity factor in acute viral bronchiolitis (AVB) in infants. METHODS: All infants less than 16 weeks old admitted to Montpellier University Hospital from 2015/10/01 to 2016/04/01 for AVB were included in a retrospective observational study. The primary objective was to determine whether the hemoglobin (Hb) concentration on admission was an independent factor of clinical severity, judged by the modified Wood's clinical asthma score (m-WCAS). The secondary objective was to assess the impact of Hb level on the characteristics of hospitalization, including the type and duration of respiratory support. RESULTS: The m-WCAS was used at least once during hospitalization in 180 out of 220 patients (82%), making it possible to distinguish patients with mild AVB (maximum m-WCAS<2, n=81) from patients with severe AVB (maximum m-WCAS>2, n=99). A logistic regression model indicated that the Hb concentration, for every 1g/dL decrement, was an independent factor of AVB severity (OR 1.16 [1.03-1.29], P=0.026). A level under 10g/dL on admission was associated with a higher use of continuous positive airway pressure (P<0.001), as well as a longer duration of respiratory support (P=0.01). CONCLUSION: This study suggested that anemia may influence the clinical expression of AVB in young infants.


Assuntos
Anemia/complicações , Bronquiolite Viral/complicações , Índice de Gravidade de Doença , Bronquiolite Viral/terapia , Pressão Positiva Contínua nas Vias Aéreas , Feminino , Hemoglobinas/análise , Hospitalização , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Masculino , Estudos Retrospectivos
6.
Mater Sci Eng C Mater Biol Appl ; 77: 731-738, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28532086

RESUMO

This paper focuses on the fabrication of three-dimensional porous PLGA-biomimetic carbonated apatite composite scaffolds by freeze-casting and using dimethyl carbonate as a solvent. Several charge/polymer ratios were tested in order to finely understand the influence of the filler rate on the scaffold porosity and mechanical and degradation properties using complementary characterization techniques (SEM, mercury porosimetry and X-ray microtomography). It was demonstrated that the apatite ratio within the composite scaffold has a strong influence in terms of architecture, material cohesion, mechanical properties and in vitro degradation properties. An optimum biomimetic apatite ratio was reached to combine good mechanical properties (higher rigidity) and material cohesion. In vitro degradation studies showed that higher apatite filler rates limited PLGA degradation and enhanced the hydrophilicity of the scaffolds which is expected to improve the biological properties of the scaffolds in addition to the bioactivity related to the presence of the apatite analogous to bone mineral.


Assuntos
Ácido Láctico/química , Ácido Poliglicólico/química , Apatitas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Porosidade , Engenharia Tecidual , Alicerces Teciduais
7.
Colloids Surf B Biointerfaces ; 151: 143-155, 2017 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27992845

RESUMO

Biomaterials surface design is critical for the control of materials and biological system interactions. Being regulated by a layer of molecular dimensions, bioadhesion could be effectively tailored by polymer surface grafting. Basically, this surface modification can be controlled by radical polymerization, which is a useful tool for this purpose. The aim of this review is to provide a comprehensive overview of the role of surface characteristics on bioadhesion properties. We place a particular focus on biomaterials functionalized with a brush surface, on presentation of grafting techniques for "grafting to" and "grafting from" strategies and on brush characterization methods. Since atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization are the most frequently used grafting techniques, their main characteristics will be explained. Through the example of poly(N-isopropylacrylamide) (PNIPAM) which is a widely used polymer allowing tuneable cell adhesion, smart surfaces involving PNIPAM will be presented with their main modern applications.


Assuntos
Resinas Acrílicas/química , Materiais Biocompatíveis/química , Adsorção , Adesão Celular , Humanos , Cinética , Microscopia Eletrônica de Varredura , Polimerização , Polímeros/química , Propriedades de Superfície , Temperatura , Engenharia Tecidual/métodos
8.
Biomed Mater ; 7(5): 054101, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22971953

RESUMO

Due to their bioactivity and osteoconductivity, hydroxyapatite (HA) plasma sprayed coatings have been widely developed for orthopedic uses. However, the thermodynamic instability of HA leads frequently to a mixture of phases which limit the functional durability of the coating. This study investigates the plasma spraying of chlorapatite (ClA) powder, known to melt without decomposition, onto pure titanium substrates using a low energy plasma spray system (LEPS). Pure ClA powder was prepared by a solid gas reaction at 950 °C and thermogravimetric analysis showed the good thermal stability of ClA powder in the range 30-1400 °C compared to that of the HA powder. Characterization of ClA coating showed that ClA had a very high crystalline ratio and no other crystalline phase was detected in the coating. HA and ClA coatings composition, microstructure and in vitro bioactivity potential were studied, compared and discussed. In vitro SBF test on HA and ClA coatings revealed the formation of a poorly crystalline apatite on the coating surface suggesting that we could expect a good osteoconductivity especially for the ClA coating prepared by the LEPS system.


Assuntos
Apatitas/química , Materiais Biocompatíveis/química , Durapatita/química , Líquidos Corporais/química , Fenômenos Químicos , Materiais Revestidos Biocompatíveis/química , Cristalização , Estabilidade de Medicamentos , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Difração de Pó , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Difração de Raios X
10.
Acta Paediatr ; 101(8): 846-51, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22519364

RESUMO

AIM: Premature birth is frequent in infants conceived with assisted reproductive technologies (ART). We sought to determine whether neonatal outcome in ART preterm infants differs from that of spontaneously conceived (SC) preterm infants. METHODS: Data were prospectively collected in infants born ≤ 32 weeks after ART or SC. We calculated a composite index of severe morbidity (based on occurrences of severe necrotizing enterocolitis, severe intraventricular haemorrhage, periventricular leukomalacia or bronchopulmonary dysplasia). Survival rate without severe morbidity was compared between the two groups. RESULTS: Six hundred and twelve preterm infants were hospitalized in our tertiary care centre: 81 in ART group and 521 in SC group. In the ART group, twin pregnancy (69.1% vs. 15.9%, p < 0.001) and inborn delivery (98.8% vs. 90.0%, p < 0.01) were more frequent. Gestational age (29 vs. 28 weeks, p < 0.05) and birth weight (1100 vs. 1020 g, p < 0.001) were also higher. Survival without severe morbidity was significantly higher in ART infants (76.5% vs. 55.2%, p < 0.001), with the difference mainly observed in infants born ≤ 28 weeks (22.9% vs. 55.7%, p < 0.001). CONCLUSION: Assisted reproductive technologies was not associated with adverse neonatal outcome. Differences in pregnancy and neonatal characteristics probably explain the increased survival without severe morbidity in ART infants.


Assuntos
Mortalidade Infantil , Doenças do Prematuro , Técnicas de Reprodução Assistida , Feminino , França/epidemiologia , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/mortalidade , Modelos Logísticos , Masculino , Análise Multivariada , Gravidez , Nascimento Prematuro/epidemiologia , Nascimento Prematuro/etiologia , Estudos Prospectivos , Técnicas de Reprodução Assistida/efeitos adversos , Índice de Gravidade de Doença , Taxa de Sobrevida
12.
Encephale ; 37 Suppl 1: S11-8, 2011 May.
Artigo em Francês | MEDLINE | ID: mdl-21600328

RESUMO

Schizophrenia is a frequent disorder since it affects about 1% of the general population. Drug compliance, that is to say patients' adherence to their treatment, remains rather poor concerning this disease with, on an average, one patient out of two not complying with his/her medication. Among the factors influencing drug compliance, we focused on patients' beliefs in terms of health control, a concept known as health locus of control. This is a concept that originated from social psychology and derived from the Rotters' original concept of locus of control: it corresponds to the type of connexion established by an individual between subsequent events in the history of his/her disease and internal (personal abilities) or external factors (chance, powerful others). Nowadays, the tridimensional structure of this concept is commonly admitted as being in three dimensions: internality, chance externality and powerful others externality, the latter group being divided between doctors and others. We have assumed that there is a correlation between the degree of drug compliance and the internal and/or doctors' external health locus of control. For this purpose, we have determined the quality of drug compliance by using the Medical Adherence Rating Scale (MARS) and the type of health locus of control by using the Multidimensional Health Locus of Control (MHLC) scale among 65 schizophrenic patients. We have also considered it was important to evaluate patients' insight by using the Amador's scale (Scale of Unawareness of Mental Disorder) because many researchers have established a strong correlation between insight and drug compliance in schizophrenia. Associations between the four dimensions of health locus of control ("internal", "chance external", "others external" and "doctors' external") and drug compliance were assessed by estimating Spearman's rank correlation coefficient (r) and its degree of significance (p). These associations were judged significant at an alpha threshold of 5%, which corresponded to a level of p inferior to 0.05. Our results tend to confirm a statistically significant positive correlation between internal (r=0.25; p=0.043) and/or doctors' external (r=0.27; p=0.027) health locus of control and drug compliance. Conversely, there is no correlation between chance external or others' external health locus of control and drug compliance (p>0.05). This means that the more patients believe that their schizophrenia can be controlled by themselves and/or by doctors, the more they follow their prescriptions. Furthermore, the link between health locus of control and drug compliance appears to be confused by two dimensions of insight, namely awareness of the response to the treatment and perceived need for treatment. An application of these results is that, in the case of patients whose health locus of control is chance or others' external, it can be beneficial to attempt to change their beliefs in order to improve drug compliance. These results hold particular interest in the field of psycho-education and can be directly applied to cognitive therapy for beliefs among stabilized schizophrenic patients.


Assuntos
Antipsicóticos/uso terapêutico , Atitude Frente a Saúde , Controle Interno-Externo , Adesão à Medicação/psicologia , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Adulto , Antipsicóticos/efeitos adversos , Conscientização , Delusões/diagnóstico , Delusões/psicologia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Feminino , Alucinações/diagnóstico , Alucinações/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Educação de Pacientes como Assunto , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários
13.
Acta Biomater ; 7(4): 1817-26, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21147278

RESUMO

In part I of this study we aim to evaluate and control the characteristics of the powders constituting the solid phase of a vaterite CaCO(3)-dicalcium phosphate dihydrate cement using a co-grinding process and to determine their impact on cement setting ability. An original methodology involving complementary analytical techniques was implemented to thoroughly investigate the grinding mechanism of separated or mixed reactive powders and the effects on solid phase reactivity. We showed that the association of both reactive powders during co-grinding improves the efficiency of this process in terms of the particle size decrease, thus making co-grinding adaptable to industrial development of the cement. For the first time the usefulness of horizontal attenuated total reflection Fourier transform infrared spectroscopy to follow the chemical setting reaction at 37°C in real time has been demonstrated. We point out the antagonist effects that co-grinding can have on cement setting: the setting time is halved; however, progress of the chemical reaction involving dissolution-reprecipitation is delayed by 30 min, probably due to the increased contact area between the reactive powders, limiting their hydration. More generally, we can take advantage of the co-grinding process to control powder mixing, size and reactivity and this original analytical methodology to better understand its effect on the phenomena involved during powder processing and cement setting, which is decisive for the development of multi-component cements.


Assuntos
Cimentos Ósseos/química , Carbonato de Cálcio/química , Fosfatos de Cálcio/química , Teste de Materiais/métodos , Tamanho da Partícula , Microscopia Eletrônica de Varredura , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Fatores de Tempo , Difração de Raios X
14.
Acta Biomater ; 6(9): 3362-78, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20167295

RESUMO

This review paper on amorphous calcium phosphates (ACPs) provides an update on several aspects of these compounds which have led to many studies and some controversy since the 1970s, particularly because of the lack of irrefutable proof of the occurrence of an ACP phase in mineralised tissues of vertebrates. The various synthesis routes of ACPs with different compositions are reported and the techniques used to characterise this phase are reviewed. We focus on the various physico-chemical properties of ACPs, especially the reactivity in aqueous media, which have been exploited to prepare bioactive bone substitutes, particularly in the form of coatings and cements for orthopaedic applications and composites for dental applications.


Assuntos
Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , Fosfatos de Cálcio/síntese química , Teste de Materiais
15.
Rev Med Interne ; 31(2): 140-5, 2010 Feb.
Artigo em Francês | MEDLINE | ID: mdl-19740577

RESUMO

INTRODUCTION: Tumors of the pituitary stalk are rare and their diagnosis is sometimes difficult. CASE REPORT: We report a case of a primary lymphoma of the pituitary stalk in a 78-year-old patient. To our knowledge, only seven similar cases have been previously published: prominent symptoms were headache, fatigue and diplopia; biologically, anterior pituitary low secretion or hyperprolactinemia were found in the majority of cases; regarding the imaging, only three patients presented an initial and isolated lesion of the stalk; histological evidence was obtained by a trans-sphenoidal biopsy in case of hypothalamic or pituitary associated lesion or by a trans-cranial biopsy in the event of an isolated lesion. As an alternative, a lumbar puncture could be performed; although less invasive, its diagnostic performance is lower. CONCLUSION: Current treatment relies on chemotherapy with intravenous methotrexate associated with intrathecal methotrexate infusion if cerebrospinal showed abnormal cells. Unfortunately, the results remain poor with a median survival of 9 months.


Assuntos
Linfoma/patologia , Metotrexato/uso terapêutico , Neoplasias Hipofisárias/patologia , Idoso , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/uso terapêutico , Biópsia , Neoplasias do Sistema Nervoso Central/patologia , Feminino , Humanos , Linfoma/diagnóstico por imagem , Linfoma/tratamento farmacológico , Imageamento por Ressonância Magnética , Metotrexato/administração & dosagem , Neoplasias Hipofisárias/diagnóstico por imagem , Neoplasias Hipofisárias/tratamento farmacológico , Punção Espinal , Análise de Sobrevida , Tomografia Computadorizada por Raios X
16.
Acta Biomater ; 6(3): 920-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19716448

RESUMO

With the development of minimally invasive surgical techniques, there is growing interest in the research and development of injectable biomaterials with controlled rheological properties. In this context, the rheological properties and injectability characteristics of an original CaCO(3) self-setting paste have been investigated. Two complementary rheometrical procedures have been established using a controlled stress rheometer to follow the structure build-up at rest or during gentle mixing and/or handling on the one hand, and the likely shear-induced breakdown of this structure at 25 or 35 degrees Celsius on the other. The data obtained clearly show the influence of temperature on the development of a cement microstructure during setting, in all cases leading to a microporous cement made of an entangled network of aragonite-CaCO(3) needle-like crystals. Linear viscoelastic measurements arriving from an oscillatory shear at low deformation showed a progressive increase in the viscous modulus (G'') during paste setting, which is enhanced by an increase in temperature. In addition, steady shear measurements revealed the shear-thinning behaviour of this self-setting paste over an extended period after paste preparation and its ability to re-build through progressive paste setting at rest. The shear-thinning behaviour of this self-setting system was confirmed using the injectability system and a procedure we designed. The force needed to extrude a homogeneous and continuous column of paste decreases strongly upon injection and reaches a weight level to apply on the syringe piston around 2.5 kg, revealing the ease of injection of this CaCO(3) self-setting paste.


Assuntos
Cimentos Ósseos/química , Substitutos Ósseos/química , Carbonato de Cálcio/química , Substitutos Ósseos/administração & dosagem , Força Compressiva , Módulo de Elasticidade , Dureza , Injeções , Teste de Materiais , Viscosidade
19.
J Biomed Mater Res A ; 79(2): 318-28, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16817210

RESUMO

The feasibility of making calcium carbonate-calcium phosphate (CaCO(3)-CaP) mixed cements, comprising at least 40% (w/w) CaCO(3) in the dry powder ingredients, has been demonstrated. Several original cement compositions were obtained by mixing metastable crystalline CaCO(3) phases with metastable amorphous or crystalline CaP powders in aqueous medium. The cements set within at most 1 h at 37 degrees C in atmosphere saturated with water. The hardened cement is microporous and exhibits weak compressive strength. The setting reaction appeared to be essentially related to the formation of a highly carbonated nanocrystalline apatite phase by reaction of the metastable CaP phase with part or almost all of the metastable CaCO(3) phase. The recrystallization of metastable CaP varieties led to a final cement consisting of a highly carbonated poorly crystalline apatite analogous to bone mineral associated with various amounts of vaterite and/or aragonite. The presence of controlled amounts of CaCO(3) with a higher solubility than that of the apatite formed in the well-developed CaP cements might be of interest to increase resorption rates in biomedical cement and favors its replacement by bone tissue. Cytotoxicity testing revealed excellent cytocompatibility of CaCO(3)-CaP mixed cement compositions.


Assuntos
Cimentos Ósseos/química , Cimentos Ósseos/metabolismo , Osso e Ossos/metabolismo , Carbonato de Cálcio/química , Fosfatos de Cálcio/química , Materiais Biocompatíveis/química , Fenômenos Biomecânicos , Força Compressiva , Cristalização , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Modelos Químicos , Pós , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
20.
J Neuroradiol ; 33(3): 184-8, 2006 Jun.
Artigo em Francês | MEDLINE | ID: mdl-16840961

RESUMO

We propose studying signs of cervicothoracic CSF hypotension by MRI. Axial T1-weighted GRE sequence with and without saturation bands positioned above and below the selected image plane, MR venography and MR Angiography with contrast administration are helpful to confirm the venous nature of the epidural thickening and to make the differential diagnosis with infectious or neoplastic epiduritis.


Assuntos
Hipotensão Intracraniana/líquido cefalorraquidiano , Hipotensão Intracraniana/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adulto , Pressão do Líquido Cefalorraquidiano , Meios de Contraste , Diagnóstico Diferencial , Feminino , Gadolínio , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
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