1,385 research outputs found
Stress Intensity Factor Equations for the Evolution of Surface and Corner Cracks to Through Cracks
Part-through surface or corner 2D cracks are commonly found in structural components, even because practically all fatigue cracks tend to start this way. It is a reasonable hypothesis to model them assuming the shape of their 2D fronts can be approximated by an elliptical arc, as supported by many fractographic observations. However, their transition to a 1D through-crack, an important issue in many practical applications, is normally not properly addressed in fatigue life predictions. Although experimental results reveal that the frontiers of surface cracks essentially retain their elliptical shape as they gradually grow into an 1D through-crack, it is usual to assume they are immediately transformed into an 1D through-crack when their depth reaches the cracked component thickness. This crude approximation may create a large jump in stress intensity values, leading to excessively conservative fatigue crack growth predictions; or else, the crude shape jump hypothesis might induce false overload events that can much affect fatigue crack growth retardation models, leading to inadmissible non-conservative life predictions. To minimize such problems, an improved model to describe the transition of 2D surface cracks to 1D through-cracks is proposed and verified by crack propagation tests in two different materials, 4340 steel and polycarbonate (PC). Moreover, fatigue life predictions based on this improved model are compared with experimental results obtained with these two materials
Modeling 2D surface to 1D through-crack transitions using 2D point load weight function
Part-through surface or corner 2D cracks are commonly found in structural components. To
model them assuming that the shape of their fronts is approximately elliptic is a quite reasonable hypothesis
supported by fractographic observations, but their transition to a 1D through-crack normally is not properly
addressed in fatigue life predictions. Although experimental data reveal that the frontier of 2D superficial
cracks essentially retain their elliptical shape as they gradually grow into a through-crack, it is usual to assume
they are immediately transformed into a 1D through-crack when their depth reaches the cracked component
thickness. This oversimplified approximation may create a large jump in stress intensity values, leading to
excessively conservative fatigue crack growth predictions, or else the crude shape jump hypothesis may
induce false overload events that can much affect fatigue crack growth retardation models, leading to
inadmissible non-conservative life predictions. To minimize such problems, a crack propagation strategy,
based on a point load weight function, is proposed and verified by 2D crack propagation tests in two different
materials, 4340 steel and polycarbonate (PC)
Antioxidant action of the flavonoids derivatives
O objetivo deste trabalho foi verificar o efeito antioxidante de derivados flavonoídicos da quercetina, naringenina, morina, e rutina, isolados da cultivar de soja UFV-5. Após acetilação com anidrido acético e piridina, e metilação com diazometano, esses compostos foram analisados para determinação de ação antioxidante por meio dos índices de acidez, iodo e peróxido e pela reação-de-Kreiss. Os melhores resultados foram obtidos com a naringenina metilada, naringenina acetilada, quercetina metilada e quercetina acetilada.The objective of this work was to verify the antioxidant effect of the flavonoid compounds quercetin, naringenin, morin, and rutin isolated from soybean, cultivar UFV-5. After acetylation with acetic anydride and pyridine, and methylation with diazomethane, indexes of acidity, iodine, and peroxide and Kreiss reaction were determined. The best results were obtained with methylated naringenin, acetylated naringenin, methylated quercetin, and acetylated quercetin
Legislation in Hospital Dentistry: Gaps, Perspectives and Desires
Objective: To analyze the existing state legislation, including not only the ordinary laws, but also their infralegal regulation and the state legislation on Hospital Dentistry. Material and Methods: A survey was carried out in the databases of the Legislative Assemblies of the Brazilian States and the Federal District, as well as the Regional and Federal Councils of Dentistry in Brazil. Subsequently, a survey was carried out in the databases of the Ministry of Health, State Dental Councils and Federal Dental Council in Brazil. Results: Only 8 Brazilian states have legislation in force regarding hospital dentistry, which represents 29.63% of the federative units. Among the Brazilian regions, the Midwest presented the highest prevalence of the laws found (37.50%), followed by the North (25%) and the other regions with the same coverage (12.50%). Also, an orientation and an ordinance from the Ministry of Health, six resolutions from the Federal Council of Dentistry, and a technical note from the National Health Surveillance Agency were found. Conclusion: Several States do not have rules on the subject, making it imperative to create a federal rule that not only imposes the presence of the dentist, but also regulates the proportion of the team, workload, and availability
Perinatal outcomes in pregnant drug users attended at a specialized center
Objetivo: analisar as repercussões perinatais do uso de drogas por gestantes atendidas em um ambulatório de alto risco. Método: estudo caso-controle, no qual foram avaliados 920 prontuários, no período de 2012-2013. O grupo caso foi constituído pelas gestantes usuárias de drogas lícitas/ilícitas (41) e o controle por gestantes de risco não usuárias (82). Resultados: as gestantes usuárias apresentaram risco aumentado para prematuridade (RR=2,64, p=0,02), baixo peso ao nascer (RR=5,42, p=0,01) e baixo índice de Apgar no 1º minuto (RR=2,97, p=0,01). Conclusão: os resultados indicam que gestantes usuárias de drogas apresentam desfechos perinatais desfavoráveis à gestação.Objective: to analyze the perinatal repercussions of drug use by pregnant women treated in a high risk outpatient clinic. Method: a case-control study in which 920 medical records were evaluated in the period 2012-2013. The case group consisted of pregnant women who used licit/illicit drugs (41) and the control group of non-user pregnant women (82). Results: pregnant women using drugs presented increased risk for prematurity (RR = 2.64, p = 0.02), low birth weight (RR = 5.42, p = 0.01) and low one-minute Apgar score (RR = 2.97, p = 0.01). Conclusion: the results indicate that pregnant women who use drugs have unfavorable perinatal outcomes during gestation.Objetivo: analizar los resultados perinatales de consumo de drogas por mujeres embarazadas en una clínica de alto riesgo. Método: estudio de casos y controles, que evaluó 920 registros médicos, en 2012-2013. El grupo de casos estaba compuesto de las mujeres embarazadas que drogas lícitas/ilegales (41) y el control del riesgo de las mujeres embarazadas no consumidores (82). Resultados: las mujeres embarazadas que se encontraban en mayor riesgo de parto prematuro (RR = 2,64, p = 0,02), bajo peso al nacer (RR = 5,42, p = 0,01) y la puntuación de Apgar baja a 1 minuto (RR = 2,97, p = 0,01). Conclusión: los resultados indican que las mujeres embarazadas que tienen las drogas adversos del embarazo los resultados perinatales
Análise da substituição do aço por bambu em estruturas de concreto armado / Analysis of steel replacement by bamboo in armored concrete structures
Com a necessidade de produção elevada e redução de custos na construção civil, acoplado a preservação do meio ambiente, cresce a busca por materiais alternativos que possam desempenhar as mesmas características dos convencionais em uma edificação. O bambu, elemento natural, apresenta características que mais se adequam em uma possível substituição do aço no concreto armado, justificando assim essa pesquisa, que possui o objetivo de analisar as características e as propriedades de ambos materiais. Para isso, foi feito uma revisão de literatura onde foram definidos descritores de pesquisa e selecionados produções que estudassem o assunto abordado, tal como a filtragem dessas publicações, resultando em 23 publicações base. Os resultados demonstraram os diversos parâmetros de comparação dos materiais, dentre vantagens e desvantagens da substituição. Foi visto que o bambu possui altas resistências a tração e compressão que podem chegar a 240 e 80 MPa, respectivamente, dentre outras características como boa dilatação térmica e durabilidade. O processo de proteção do aço e do bambu é extremamente importante pela proteção contra corrosão e fungos, respectivamente. Conclui-se que ainda existem obstáculos a serem supridos na substituição do aço pelo bambu por diversas características, como a baixa resistência a cisalhamento, variabilidade geométrica, aderência ao concreto e o baixo módulo de elasticidade. Esses fatores são preponderantes ao analisar a eficiência completa na possível substituição do aço. Consta-se, no entanto, que é o elemento que mais aproxima das características do aço, além de suas determinadas espécies possuírem altos valores de tração e compressão
O referenciamento de usuários ao centro de atenção psicossocial álcool e drogas
O objetivo deste trabalho é conhecer, descrever e problematizar o referenciamento de usuários ao Centro de Atenção Psicossocial Álcool e Drogas (CAPS ad) em Teresina (PI). Estudo descritivo realizado no CAPS ad após a investigação de 272 prontuários do período de julho de 2013 a janeiro de 2014. Identificou-se um pequeno número de usuários oriundos da Estratégia Saúde da Família (2,94%), enquanto que a demanda espontânea e as indicações de amigos e familiares somam 53,3%, além de se ter constatado que existem vários pontos emissores de referenciamento para o usuário. Tais resultados sugerem a necessidade de uma avaliação do trabalho realizado pela Estratégia Saúde da Família frente a esta demanda, a fim de se problematizar a sua falta de integração com o CAPS ad com vistas em ações resolutivas da vigilância em saúde, as quais controlem os entraves ao referenciamento dos usuários
Risk factors, biochemical markers, and genetic polymorphisms in early coronary artery disease
OBJECTIVE: To assess the risk factors, lipid and apolipoprotein profile, hemostasis variables, and polymorphisms of the apolipoprotein AI-CIII gene in early coronary artery disease (CAD). METHODS: Case-control study with 112 patients in each group controlled by sex and age. After clinical evaluation and nutritional instruction, blood samples were collected for biochemical assays and genetic study. RESULTS: Familial history of early CAD (64 vs 39%), arterial hypertension (69 vs 36%), diabetes mellitus (25 vs 3%), and previous smoking (71 vs 46%) were more prevalent in the case group (p<0.001). Hypertension and diabetes were independent risk factors. Early CAD was characterized by higher serum levels of total cholesterol (235 ± 6 vs 209 ± 4 mg/dL), of LDL-c (154 ± 5 vs 135 ± 4 mg/dL), triglycerides (205 ± 12 vs 143 ± 9 mg/dL), and apolipoprotein B (129 ± 3 vs 105 ± 3 mg/dL), and lower serum levels of HDL-c (40 ± 1 vs 46 ± 1 mg/dL) and apolipoprotein AI (134 ± 2 vs 146 ± 2mg/dL) [p<0.01], in addition to an elevation in fibrinogen and D-dimer (p<0.02). The simultaneous presence of the rare alleles of the APO AI-CIII genes in early CAD are associated with hypertriglyceridemia (p=0.03). CONCLUSION: Of the classical risk factors, hypertension and diabetes mellitus were independently associated with early CAD. In addition to an unfavorable lipid profile, an increase in the thrombotic risk was identified in this population. An additive effect of the APO AI-CIII genes was observed in triglyceride levels.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo (UNIFESP) EPMUNIFESP, EPMSciEL
A review of Cushing’s disease treatment by the Department of Neuroendocrinology of the Brazilian Society of Endocrinology and Metabolism
The treatment objectives for a patient with Cushing’s disease (CD) are remission of hypercortisolism, adequate management of co-morbidities, restoration of the hypothalamic-pituitary-adrenal axis, preservation of fertility and pituitary function, and improvement of visual defects in cases of macroadenomas with suprasellar extension. Transsphenoidal pituitary surgery is the main treatment option for the majority of cases, even in macroadenomas with low probability of remission. In cases of surgical failure, another subsequent pituitary surgery might be indicated in cases with persistent tumor imaging at post surgical magnetic resonance imaging (MRI) and/or pathology analysis of adrenocorticotropic hormone-positive (ACTH+) positive pituitary adenoma in the first procedure. Medical treatment, radiotherapy and adrenalectomy are the other options when transsphenoidal pituitary surgery fails.There are several options of medical treatment, although cabergoline and ketoconazole are the most commonly used alone or in combination. Novel treatments are also addressed in this review. Different therapeutic approaches are frequently needed on an individual basis, both before and, particularly, after surgery, and they should be individualized. The objective of the present review is to provide the necessary information to achieve a more effective treatment for CD. It is recommended that patients with CD be followed at tertiary care centers with experience in treating this condition
- …