Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Appetite ; 87: 62-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25478687

RESUMO

BACKGROUND: Morbid obesity is a highly prevalent condition that is associated with a high risk of various diseases and high health care costs. Understanding determinants of eating behaviours that are characteristic of many morbidly obese persons is important for the development of new interventions aimed at changing eating behaviour after bariatric surgery. Dispositional mindfulness seems promising as one such potential determinant. Therefore, the association between mindfulness and eating behaviour was examined in females and males with morbid obesity. METHODS: Outpatients with morbid obesity who were candidates for bariatric surgery (N = 335; 78.8% female) completed the Dutch Eating Behaviour Questionnaire (DEBQ), the Freiburg Mindfulness Inventory (FMI) and the Hospital Anxiety and Depression Scale (HADS), in addition to the collection of relevant demographic and medical data. RESULTS: Three separate multiple regression analyses with three eating behaviour styles (restrained, emotional, external) as dependent variables showed that mindfulness was positively associated with restrained eating behaviour (Beta = .28, p ≤ .001), and negatively associated with emotional (Beta = -.22, p ≤ .001) and external (Beta = -.32, p ≤ .001) eating behaviours, independent of sex, age, educational level, Body Mass Index and affective symptoms. CONCLUSION: Dispositional mindfulness was associated with more restrained, and less emotional and external eating behaviour in morbidly obese outpatients, above and beyond affective symptoms. Future studies, establishing the causal direction of the associations, are needed.


Assuntos
Ingestão de Alimentos/psicologia , Emoções , Comportamento Alimentar/psicologia , Atenção Plena , Obesidade Mórbida/psicologia , Personalidade , Controles Informais da Sociedade , Adulto , Sintomas Afetivos , Cirurgia Bariátrica , Índice de Massa Corporal , Feminino , Humanos , Hiperfagia/psicologia , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
2.
Radiography (Lond) ; 30(3): 986-994, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678978

RESUMO

INTRODUCTION: To investigate the predictive value of the pre-treatment diffusion parameters of diffusion-weighted magnetic resonance imaging (DW-MRI) using artificial intelligence (AI) for prostate-specific antigen (PSA) response in patients with low- and intermediate-risk prostate cancer (PCa) treated with stereotactic ablative radiotherapy (SABR). METHODS: Retrospective evaluation was performed for 30 patients using pre-treatment multi-parametric MR image datasets between 2017 and 2021. MR-based mean- and minimum apparent diffusion coefficients (ADCmean, ADCmin) were calculated for the intraprostatic dominant lesion. Therapeutic response was assessed using PSA levels. Predictive performance was assessed by the receiver operating characteristic (ROC) analysis. Statistics performed with a significance level of p ≤ 0.05. RESULTS: No biochemical relapse was detected after a median follow-up of twenty-three months (range: 3-50), with a median PSA of 0.01 ng/ml (range: 0.006-2.8) at the last examination. Significant differences were observed between the pre-treatment ADCmean, ADCmin parameters, and the group averages of patients with low and high 1-year-PSA measurements (p < 0.0001, p < 0.0001). In prediction, the random forest (RF) model outperformed the decision tree (DT) and support vector machine (SVM) models by yielding area under the curves (AUC), with 0.722, 0.685, and 0.5, respectively. CONCLUSION: Our findings suggest that pre-treatment MR diffusion data may predict therapeutic response using the novel approach of machine learning in PCa patients treated with SABR. IMPLICATIONS FOR PRACTICE: Clinicians shall measure and implement the evaluation of the suggested parameters (ADCmin, ADCmean) to provide the most accurate therapy for the patient.


Assuntos
Inteligência Artificial , Imagem de Difusão por Ressonância Magnética , Valor Preditivo dos Testes , Antígeno Prostático Específico , Neoplasias da Próstata , Radiocirurgia , Humanos , Masculino , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Projetos Piloto , Idoso , Estudos Retrospectivos , Imagem de Difusão por Ressonância Magnética/métodos , Radiocirurgia/métodos , Pessoa de Meia-Idade , Antígeno Prostático Específico/sangue , Idoso de 80 Anos ou mais
3.
Gen Hosp Psychiatry ; 73: 1-8, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34482278

RESUMO

OBJECTIVE: Social inhibition may promote symptoms of depression and anxiety in adults from an outpatient hospital population. The current work builds on a previously corroborated construct of social inhibition and examines the psychometric properties of this assessment tool and its predictive validity in the adult outpatient hospital population. METHODS: A total of 350 adult outpatients receiving treatment at the department of Medical Psychology or Psychiatry completed measures of social inhibition and symptoms of anxiety (7-item Generalized Anxiety Disorder scale) and depression (9-item Patient Health Questionnaire). Factor analyses, reliability estimates, and regression analyses were used to replicate the robustness of the model of social inhibition, and the 15-item Social Inhibition Questionnaire (SIQ15). RESULTS: In the current sample (N = 350; Mage = 45 years; 67.4% women), factor analyses confirmed the previously suggested three-factor model of social inhibition as measured by the SIQ15. The subscales of behavioral inhibition, interpersonal sensitivity and social withdrawal proved to be internally consistent (Cronbach's α between 0.87/0.95) and stable over time (test-retest reliability between r = 0.76/0.83). At baseline, interpersonal sensitivity and social withdrawal were associated with anxiety and depressive symptoms. At three months follow-up, only interpersonal sensitivity was related to depressive symptoms. CONCLUSIONS: Social inhibition is associated with anxiety and depression at baseline and can be reliably assessed with the SIQ15 in an outpatient hospital population. The association of interpersonal sensitivity with depressive symptoms at three-month follow-up suggests an important aim for future research on the development of preventive methods for affective symptoms in socially inhibited outpatients.


Assuntos
Sintomas Afetivos , Pacientes Ambulatoriais , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Reprodutibilidade dos Testes , Inquéritos e Questionários
4.
ACS Appl Mater Interfaces ; 11(45): 42549-42560, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31566942

RESUMO

Tailoring of material architectures in three-dimensions enabled by additive manufacturing (AM) offers the potential to realize bulk materials with unprecedented properties optimized for location-specific structural and/or functional requirements. Here we report tunable energy absorption characteristics of architected honeycombs enabled via material jetting AM. We realize spatially tailored 3D printed honeycombs (guided by FE studies) by varying the cell wall thickness gradient and evaluate experimentally and numerically the energy absorption characteristics. The measured response of architected honeycombs characterized by local buckling (wrinkling) and progressive failure reveals over 110% increase in specific energy absorption (SEA) with a concomitant energy absorption efficiency of 65%. Design maps are presented that demarcate the regime over which geometric tailoring mitigates deleterious global buckling and collapse. Our analysis indicates that an energy absorption efficiency as high as 90% can be achieved for architected honeycombs, whereas the efficiency of competing microarchitected metamaterials rarely exceeds 50%. The tailoring strategy introduced here is easily realizable in a broad array of AM techniques, making it a viable candidate for developing practical mechanical metamaterials.

5.
R Soc Open Sci ; 4(3): 160939, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28405383

RESUMO

Experiments were conducted on an aqueous growth medium containing cultures of Escherichia coli (E. coli) XL1-Blue, to investigate, in a single experiment, the effect of two types of dynamic mechanical loading on cellular integrity. A bespoke shock tube was used to subject separate portions of a planktonic bacterial culture to two different loading sequences: (i) shock compression followed by cavitation, and (ii) shock compression followed by spray. The apparatus allows the generation of an adjustable loading shock wave of magnitude up to 300 MPa in a sterile laboratory environment. Cultures of E. coli were tested with this apparatus and the spread-plate technique was used to measure the survivability after mechanical loading. The loading sequence (ii) gave higher mortality than (i), suggesting that the bacteria are more vulnerable to shear deformation and cavitation than to hydrostatic compression. We present the results of preliminary experiments and suggestions for further experimental work; we discuss the potential applications of this technique to sterilize large volumes of fluid samples.

6.
Neuroscience ; 230: 132-8, 2013 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-23159320

RESUMO

Here we investigate the contribution of striatal dopamine receptors (D1) to the influence of reward-magnitude on learning. Pigeons (Columba livia) were trained on a discrimination-task with two pairs of stimuli; correct discrimination resulted in a large reward in one pair of stimuli and in a small reward in the other pair. Acquisition of the discrimination-task was accompanied by intracranial injections to the medial striatum, either of a dopamine-antagonist (Sch23390) or of vehicle. In the control-condition the rate of learning was modulated by the magnitude of the reward; discrimination was learned faster if contingent rewards were large and learning was slower if contingent rewards were small. Following injections of D1 antagonist this effect vanished even though the ability to discriminate between the rewards was unaffected. Interestingly, the mean rate of learning was indistinguishable between the control and antagonist conditions. Consequently, it appears that not learning per se but the effect of reward-magnitude on learning is mediated through D1 receptors in the striatum. We argue that the injections of dopamine-antagonist cause a shift in strategy underlying learning. In the control-condition animals rely on positive feedback and thus learning is affected by the magnitude of the contingent reward; in the antagonist-condition, however, learning might rely on negative feedback and is thus insensitive to reward-magnitude.


Assuntos
Condicionamento Operante/fisiologia , Corpo Estriado/metabolismo , Aprendizagem por Discriminação/fisiologia , Receptores de Dopamina D1/metabolismo , Recompensa , Análise de Variância , Animais , Benzazepinas/farmacologia , Comportamento de Escolha/efeitos dos fármacos , Columbidae , Condicionamento Operante/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Aprendizagem por Discriminação/efeitos dos fármacos , Antagonistas de Dopamina/farmacologia
7.
Herzschrittmacherther Elektrophysiol ; 22(3): 181-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21710200

RESUMO

The distressed (Type D) personality is an emerging risk marker for poor health outcomes in patients with cardiovascular disease. Patients with this personality disposition are typified by a general propensity to experience psychological distress. The contribution focuses on the impact of Type D personality on psychological distress, quality of life, ventricular tachyarrhythmias, and mortality in implantable cardioverter-defibrillator (ICD) patients and examines the relative influence of this vulnerability factor compared to ICD shocks and markers of disease severity in relation to these outcomes.


Assuntos
Doenças Cardiovasculares/psicologia , Desfibriladores Implantáveis/psicologia , Desenvolvimento da Personalidade , Estresse Psicológico/complicações , Adaptação Psicológica , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/psicologia , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/terapia , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/psicologia , Humanos , Estimativa de Kaplan-Meier , Inventário de Personalidade/estatística & dados numéricos , Prognóstico , Psicometria , Qualidade de Vida/psicologia , Fatores de Risco , Taquicardia Ventricular/mortalidade , Taquicardia Ventricular/psicologia , Taquicardia Ventricular/terapia
8.
Neuroscience ; 167(2): 232-7, 2010 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-20149845

RESUMO

Selective attention is a crucial component of all sensory processing. Here we test the role of dopamine in attentional selection and in the maintenance of attention. Pigeons were trained on a moving-dot paradigm comparable to the shell game. In this paradigm, pigeons had to select a target among distractors and maintain attention to the target. Target and distractors consisted of white dots, moving at random on a touch-screen. In this task, the demand on attention was modulated by varying the number of distractors and the duration of motion. Both manipulations affected performance equally. In the next step, we investigated the contribution of dopamine to attention. Intracranial injections of D1-antagonist (Sch23390) before testing led to decrements in performance that equally affected trials with different attentional demand. This drop in performance cannot be attributed to altered motivation or motor performance. We conclude that dopamine has a critical role in attention. It is involved in the selection of targets for attention and in the stabilization of attention against interference. This is comparable to the role dopamine plays in working memory and argues for similar mechanisms underlying selective attention and working memory.


Assuntos
Atenção , Dopamina/fisiologia , Córtex Pré-Frontal/fisiologia , Animais , Benzazepinas/farmacologia , Columbidae , Estimulação Luminosa , Receptores de Dopamina D1/antagonistas & inibidores
13.
J Mol Microbiol Biotechnol ; 10(2-4): 223-33, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16645317

RESUMO

Many essential life processes, such as photosynthesis, respiration, nitrogen fixation, depend on transition metal ions and their ability to catalyze multi-electron redox and hydrolytic transformations. Here we review some recent structural studies on three multi-site metal enzymes involved in respiratory processes which represent important branches within the global cycles of nitrogen and sulfur: (i) the multi-heme enzyme cytochrome c nitrite reductase, (ii) the FAD, FeS-enzyme adenosine-5'-phosphosulfate reductase, and (iii) the siroheme, FeS-enzyme sulfite reductase. Structural information comes from X-ray crystallography and spectroscopical techniques, in special cases catalytically competent intermediates could be trapped and characterized by X-ray crystallography.


Assuntos
Bactérias/metabolismo , Proteínas de Bactérias/metabolismo , Modelos Moleculares , Nitratos/metabolismo , Sulfatos/metabolismo , Citocromos a1/metabolismo , Citocromos c1/metabolismo , Transporte de Elétrons , Formiato Desidrogenases/metabolismo , Nitrato Redutases/metabolismo , Sulfito Redutase (Ferredoxina)/metabolismo
14.
Fortschr Kieferorthop ; 53(5): 297-303, 1992 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-1427541

RESUMO

The purpose of this study was to determine the influence of the thickness of the adhesive layer between bracket base and enamel surface on tensile bond strength. Stainless steel brackets with retentive net bases were bonded to bovine incisors with adhesive layers varying in thickness from a minimum of 0.0 mm to a maximum of 0.8 mm. Eight different orthodontic adhesives were investigated; in order to simulate the procedure of indirect bonding, combinations of two different adhesives were also tested. It was found that the highly filled composites provided greatest bond strength. Increasing the thickness of the adhesive layer had no significant influence on tensile bond strength. In the case of light-cured composites, maximum tensile bond strength was achieved at a thickness of the adhesive layer of 0.2 mm. This is probably due to better penetration of light at this thickness. In the case of chemically curing no-mix adhesives, it was impossible to produce effective adhesive layers thicker than 0.2 mm, presumably because curing at the primer paste interface becomes a problem at greater thickness. The influence of cement thickness on tensile bond strength was basically identical whether brackets were bonded with one or two adhesives. Thus, an additional adhesive-adhesive interface has no influence on bond strength. If adhesive layer thickness of more than 0.2 mm are required, a chemically cured, highly filled paste-paste system should be used.


Assuntos
Cimentos Dentários/química , Braquetes Ortodônticos , Animais , Bovinos , Técnicas In Vitro , Teste de Materiais/métodos , Teste de Materiais/estatística & dados numéricos , Propriedades de Superfície , Resistência à Tração
15.
Cancer ; 65(3): 492-8, 1990 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-2153430

RESUMO

Kaposi's sarcoma of the gingiva and skin developed in an HIV-negative renal transplant patient while he was receiving cyclosporine therapy. The Kaposi's sarcoma developed shortly after the patient had an acute infection with cytomegalovirus (CMV). Electron microscopy of the tumor's established cell line showed two types of virus-like particles. CMV DNA was identifiable in the cell line whereas infectious CMV could be isolated only after repeated passages (only after 3 months of culture). The other virus could not be identified, but did not appear to be either HIV or papilloma virus. The patient's tumor regressed after the discontinuation of cyclosporine therapy and the recovery from the acute CMV infection.


Assuntos
Infecções por Citomegalovirus/etiologia , Terapia de Imunossupressão/efeitos adversos , Sarcoma de Kaposi/microbiologia , Adulto , Animais , Citomegalovirus/isolamento & purificação , DNA Viral/análise , Neoplasias Gengivais/etiologia , Humanos , Transplante de Rim , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neoplasias Primárias Múltiplas/etiologia , Sarcoma de Kaposi/etiologia , Neoplasias Cutâneas/etiologia , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA