ABSTRACT
The use of real-time techniques to evaluate the global mixing performance of co-rotating twin-screw extruders is well consolidated, but much less is reported on the specific contribution of individual screw zones. This work uses on-line flow turbidity and birefringence to ascertain the mixing performance of kneading blocks with different geometries. For this purpose, one of the barrel segments of the extruder was modified in order to incorporate four sampling devices and slit dies containing optical windows were attached to them. The experiments consisted in reaching steady extrusion and then adding a small amount of tracer. Upon opening each sampling device, material was laterally detoured from the local screw channel, and its turbidity and birefringence were measured by the optical detector. Residence time distribution curves (RTD) were obtained at various axial positions along three different kneading blocks and under a range of screw speeds. It is hypothesized that K, a parameter related to the area under each RTD curve, is a good indicator of dispersive mixing, whereas variance can be used to assess distributive mixing. The experimental data confirmed that these mixing indices are sensitive to changes in processing conditions, and that they translate the expected behavior of each kneading block geometry.
ABSTRACT
OBJECTIVES: Renal transplant with ABO-incompatible donors expands the donor pool. Earlier studies have focused the use of protocol biopsies in ABOincompatible transplant patients. Our study described outcomes of indication (for cause) renal biopsies and clinical outcomes in patients with ABO-incompatible renal transplant. MATERIALS AND METHODS: This retrospective study included 164 patients from January 2012 to June 2019. Biochemical parameters, serial immunoglobulin G anti-ABO titers, and class I and II donor-specific antibody findings were obtained from hospital records, and renal graft biopsies were reviewed according to the Banff 2017 update. RESULTS: We analyzed the results of 65 biopsies from 54 patients. Biopsy-proven acute antibody-mediated rejection (12.8%) was found to be more prevalent than acute cellular rejection (1.8%). Patients with antibodymediated rejection all had microvascular inflammation (g+ptc score of 2 or more, where g+ptc is the sum of the glomerulitis and peritubular capillaritis scores) and were positive for C4d. Acute tubular injury per se was seen in 10.3% of patients; 65% of these patients had C4d positivity in peritubular capillaries, and only 1 patient developed chronic active antibody-mediated rejection on follow-up. Patient and death-censored graft survival rates were 92% and 98% at 1 year after transplant and 88% and 91% at 3 years, respectively. Patients with an episode of antibody-mediated rejection had lower rates of patient (76.5%) and deathcensored graft survival (84.6%) at 1 year. CONCLUSIONS: The microvascular inflammation score (g+ptc score of 2 or higher) is more reliable than diffuse C4d positivity to determine antibody-mediated rejection in ABO-incompatible transplants because diffuse C4d positivity may also be seen in etiologies unrelated to antibody-mediated rejection. Acute tubular injury with C4d positivity without microvascular injury does not confirm antibody-mediated rejection. We suggest that Banff classification be updated in ABOincompatible transplants to include diagnostic criteria for the diagnosis of antibody-mediated rejection.
Subject(s)
Organ Preservation Solutions , Biopsy , Complement C4b , Female , Graft Rejection , Humans , Inflammation , Male , Organ Preservation Solutions/adverse effects , Peptide Fragments , Retrospective Studies , Treatment OutcomeABSTRACT
Abstract: Introduction: The role of nutrition in medicine has changed from a passive function, from an adjuvant therapy, to a proactive and sophisticated therapy that prevents various health problems and changes the natural history of the disease. Recent studies show up that medical education does not sufficiently and efficiently address the patient's nutritional aspects, thus training physicians who are not confident in providing nutritional care to their patients. This study aimed to analyze and describe scientific studies that have evaluated nutrition education in medical schools, seeking within this context to find nutrition topics important for undergraduate medical education. Methods: This research was conducted through a cross-sectional, descriptive, scoping review after searching for synonyms using MeSH (Medical Subject Headings) and DeCS (Health Sciences Descriptors) tools. Results: We initially found 1.057 publications that underwent sequential screening until reaching a total of 16 articles, which achieved the scope of this research. Most articles are from the United States of America (50%), assessed a total of 860 medical students and 243 medical schools using different approaches regarding the teaching of nutrition. Final considerations: In this review, we have shown that despite several studies ratifying the well-established association between nutrition and prevention/treatment of diseases that require outpatient care, or at the hospital level, nutrition education in undergraduate medical school has not accompanied this evidence and, for many years, the subject has been underestimated. In Brazil, no studies were found on this topic with the used descriptors.
Resumo: Introdução: O papel da nutrição na medicina tem sido modificado de uma função passiva, de uma terapia adjuvante, para uma terapia proativa e sofisticada, que previne diversos agravos à saúde e modifica a história natural da doença. Estudos recentes observam que a educação médica não contempla, de maneira suficiente e eficiente, os aspectos nutricionais do cuidado destinado ao paciente, formando médicos pouco confiantes em promover cuidados nutricionais a seus pacientes. Este estudo teve como objetivos analisar e descrever estudos científicos que tenham avaliado a educação nutricional nas escolas médicas, buscando, neste contexto, encontrar temas em nutrição importantes para a graduação em Medicina. Método: Esta pesquisa foi realizada por meio de uma scoping review (revisão de escopo), do tipo transversal, descritiva, após pesquisa de sinônimos utilizando as ferramentas Medical Subject Headings (MeSH) e Descritores em Ciências da Saúde (DeCS). Resultados: Encontraram-se inicialmente 1.057 publicações que passaram por triagens sequenciais até chegarmos a um total de 16 artigos que alcançavam o escopo desta pesquisa. A maioria dos artigos é dos Estados Unidos (50%) e avaliou de maneiras diferentes um total de 860 alunos de Medicina e 243 escolas médicas em relação ao ensino da nutrição. Conclusões: Nesta revisão, evidenciamos que, a despeito dos vários estudos que ratificam a relação bem estabelecida da nutrição na prevenção e no tratamento de doenças em nível ambulatorial ou hospitalar, a educação nutricional na formação médica não acompanhou essas evidências, e, por muitos anos, o assunto foi subestimado. No Brasil não foram encontrados estudos sobre esse tema com os descritores utilizados.
ABSTRACT
Objetivo: Avaliar obesidade e hábitos de vida em estudantes de Medicina de uma faculdade particular. Métodos: Estudo de corte transversal para avaliar 219 alunos, ambos os sexos, de 18 a 27 anos. Foi aplicado um questionário padronizado e realizados exames clínicos e laboratoriais. Dados foram submetidos à análise estatística descritiva e ao teste quiquadrado. Resultados: Observou bom consumo diário de alimentos protetores para doenças cardiovasculares e baixo consumo de alimentos de risco para essas doenças. Foram encontrados: obesidade, 1,4%; sobrepeso, 16,4%; peso saudável, 74,4%; baixo peso, 7,8%; 53,4% praticam atividade física; 46,6 % sedentários e uma baixa frequência de dislipidemias. Conclusões: A importância do envolvimento das faculdades em orientar futuros médicos e enfatizar a necessidade de uma alimentação saudável e incentivar os bons hábitos de vida.
