256 research outputs found

    Characterization of the Soluble Nanoparticles Formed through Coulombic Interaction of Bovine Serum Albumin with Anionic Graft Copolymers at Low pH

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    A static light scattering (SLS) study of bovine serum albumin (BSA) mixtures with two anionic graft copolymers of poly (sodium acrylate-co-sodium 2-acrylamido-2-methyl-1-propanesulphonate)-graft-poly (N, N-dimethylacrylamide), with a high composition in poly (N, N-dimethylacrylamide) (PDMAM) side chains, revealed the formation of oppositely charged complexes, at pH lower than 4.9, the isoelectric point of BSA. The core-corona nanoparticles formed at pH = 3.00, were characterized. Their molecular weight and radius of gyration were determined by SLS, while their hydrodynamic radius was determined by dynamic light scattering. Small angle neutron scattering measurements were used to determine the radius of the insoluble complexes, comprising the core of the particles. The values obtained indicated that their size and aggregation number of the nanoparticles, were smaller when the content of the graft copolymers in neutral PDMAM side chains was higher. Such particles should be interesting drug delivery candidates, if the gastrointestinal tract was to be used

    O impacto da utilização de propostas didáticas de história da matemática nas aprendizagens da grandeza comprimento por alunos do 1º ciclo do ensino básico

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    Resumo Este relatório de investigação é realizado no âmbito do mestrado profissionalizante em Educação Pré-escolar e 1.º Ciclo do Ensino Básico, na Escola Superior de Educação, que está integrada no Instituto Politécnico de Viseu. Este trabalho é realizado tendo por base dois propósitos. Por um lado, pretende-se analisar e refletir acerca das práticas adotadas no estágio das áreas curriculares de Prática de Ensino Supervisionada II e III, salientando o que foi feito em ambos os níveis de ensino e as competências pedagógicas que foram sendo adquiridas durante todo este processo. Por outro lado, procura perceber-se, através de uma investigação, o impacto da inserção de propostas didáticas relativas à História da Matemática na aprendizagem de conteúdos relativos à grandeza comprimento por uma turma de alunos do terceiro ano do 1.º ciclo do ensino básico, numa escola da rede pública, situada na região de Viseu. O estudo mostra que a integração de propostas didáticas relativas à grandeza comprimento influencia de forma positiva a aquisição de aprendizagens dos alunos. Assim, é feita uma análise e reflexão acerca das competências por mim adquiridas durante este período de tempo. Este relatório de investigação permitiu melhorar a minha capacidade crítica e reflexiva, fundamentais para a profissão docente, bem como competências relativas à investigação, que muito influenciam na prática de um docente. A investigação permite ainda refletir acerca das práticas adotadas, permitindo alterar práticas menos adequadas, substituindo-as por escolhas mais favoráveis à aprendizagem dos alunos.Abstract This research report is conducted under the professional master's degree in Preschool Education and first Cycle of basic education in Escola Superior de Educação de Viseu, which is integrated into Instituto Politécnico de Viseu. This work is based on two purposes. First, we intend to analyse and reflect the practices adopted in the internship of the curricular areas Prática de Ensino Supervisionada II and Prática de Ensino Supervisionada III, highlighting what was done and the teaching skills that have been acquired throughout this process. On the other hand, we will try to understand, through an investigation, the effect of the inclusion of didactic proposals using the History of Mathematics in learning of measurement contents, namely of the attribute of length, by a group of third year students of the first cycle of basic education of a public school, located near Viseu. This study shows that the use of didactic proposals for the History of Mathematics on measurement of length has a positive influence on the students’ learning. matics related to measure contents has a positive influence on the students’ learnings. This research report has improved the critical and reflective capacity, essential for the teaching profession, as well as skills related with research, which greatly influence the practice of teaching. The investigation allowed us to reflect about the practices, and so to change some practices that aren't so appropriate and replacing them by others that facilitate learnin

    Lateralizing Value of Interictal Spikes on Overnight Sleep-EEG Studies in Temporal Lobe Epilepsy

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    Purpose: To determine the lateralizing value of interictal epileptiform discharges (IEDs) recorded during overnight sleep-EEG studies in temporal lobe epilepsy. Because IEDs are more prevalent in non-rapid eye movement (NREM) sleep than in wakefulness, overnight sleep-EEG recordings may contribute additional lateralizing information to the epilepsy surgery evaluation beyond daytime EEGs. Methods: Twenty-four subjects with medically refractory temporal lobe epilepsy underwent continuous overnight sleep-EEG recordings. Subjects were seizure free ≤24 h before study and receiving stable doses of medication. The IED foci recorded on overnight studies were compared with daytime EEGs, interictal samples, and ictal recordings during long-term monitoring, brain magnetic resonance images (MRIs), and surgical outcome. Results: (a) In all 24 subjects, including 13 without IEDs on daytime EEGs, temporal IEDs were present during NREM sleep and were exclusively or predominantly (<95%) unilateral in 15 and bitemporal in nine. (b) Unilateral NREM IEDs were concordant with surface or depth ictal-onset regions in 14 subjects, even if MRIs were normal (three subjects) or surface ictal-onset regions were bilateral (five subjects). Eleven of 12 subjects with unilateral concordant NREM IEDs who have undergone surgery are seizure free. (c) Bitemporal IEDs were associated with postoperative seizures in all subjects with normal MRIs or widespread MRI abnormalities. However, all subjects with bitemporal IEDs and MRI hippocampal abnormalities concordant with ictal-onset regions had good to excellent surgical outcomes. Conclusions: When combined with other investigations, IEDs recorded on overnight studies add prognostic data to the epilepsy surgery evaluation not provided by daytime EEGs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66154/1/j.1528-1157.1999.tb02044.x.pd

    The expression of thymidine phosphorylase correlates with angiogenesis and the efficacy of chemotherapy using fluorouracil derivatives in advanced gastric carcinoma

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    The expression of thymidine phosphorylase (TP) and the density of microvessel in advanced gastric carcinoma were examined by immunohistochemistry to evaluate the significance of TP. The expression of TP was negative in 72 cases, positive in 54. The microvessel density correlated with the expression of TP. In total cases, patients with TP-positive tumours survived longer than those with TP-negative tumours. In patients treated with fluorouracil derivatives (FUs), the expression of TP significantly correlated with favourable prognosis and with unfavourable prognosis in those not treated with FUs. The patients with TP-positive tumours, the prognosis of patients treated with FUs was significantly better than that of those not treated with FUs. In patients with TP-positive tumours, treatment with FUs and lymph node metastasis were independent prognostic factors according to the Cox proportional hazards model. Depth of invasion and lymph node metastasis were independent prognostic factors in patients with TP-negative tumours. The determination of the expression of TP might be useful for predicting the efficacy of post-operative chemotherapy using FUs to prevent recurrence in advanced gastric carcinoma patients who undergo curative gastrectomy. © 1999 Cancer Research Campaig

    Need for enforcement of ethicolegal education – an analysis of the survey of postgraduate clinical trainees

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    BACKGROUND: The number of medical lawsuits in Japan was between 14 and 21 each year before 1998, but increased to 24 to 35 per year after 1999. There were 210 lawsuits during this 10-year period. There is a need for skills and knowledge related to ethics, which is as fundamental to the practice of medicine as basic sciences or clinical skills. in Japan education in ethics is relatively rare and its importance is not yet recognized. Establishing ethics education using legal precedents, which has already been achieved in Western countries, will be a very important issue in Japan. In the present study, a questionnaire survey was conducted among graduate intern doctors, in order to investigate whether ethics education using precedents might have a positive effect in Japan. METHODS: In 2002, a questionnaire survey entitled Physicians' Clinical Ethics was carried out in a compulsory orientation lecture given to trainees before they started clinical practice in our hospital. The attendees at this lecture were trainees who came from colleges in various districts of Japan. During the lecture, 102 questionnaires were distributed, completed by attendees and collected. The recovery rate was 100%. The questionnaire consisted of 22 questions (in three categories), of which 20 were answered by multiple choices, and the other two were answered by description. The time required to complete the questionnaire was about 10 minutes. RESULTS: The recovered questionnaires were analyzed using statistical analysis software (SPSS for Windows, Release 10.07J-1/June/2000), in addition to simple statistical analysis. answers using multiple choices for the 20 questions in the questionnaire were input into SPSS. The principal component analysis was performed for each question. As a result, the item that came to the fore was "legal precedent". Since many intern doctors were interested in understanding laws and precedents, learning about ethical considerations through education using precedents might better meet with their needs and interests. CONCLUSION: We applied a new method in which the results of principal component analysis and frequencies of answers to other questions were combined. From this we deduced that the precedent education used in Western countries was useful to help doctors acquire ethical sensitivity and was not against their will. A relationship was found between reading precedents and the influence of lawsuits, and it was thought that student participation-type precedent education would be useful for doctors in order to acquire ethical sensitivity

    The Effects of Puerarin on Rat Ventricular Myocytes and the Potential Mechanism

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    Puerarin, a known isoflavone, is commonly found as a Chinese herb medicine. It is widely used in China to treat cardiac diseases such as angina, cardiac infarction and arrhythmia. However, its cardioprotective mechanism remains unclear. In this study, puerarin significantly prolonged ventricular action potential duration (APD) with a dosage dependent manner in the micromolar range on isolated rat ventricular myocytes. However, submicromolar puerarin had no effect on resting membrane potential (RMP), action potential amplitude (APA) and maximal velocity of depolarization (Vmax) of action potential. Only above the concentration of 10 mM, puerarin exhibited more aggressive effect on action potential, and shifted RMP to the positive direction. Millimolar concentrations of puerarin significantly inhibited inward rectified K+ channels in a dosage dependent manner, and exhibited bigger effects upon Kir2.1 vs Kir2.3 in transfected HEK293 cells. As low as micromolar range concentrations of puerarin significantly inhibited Kv7.1 and IKs. These inhibitory effects may due to the direct inhibition of puerarin upon channels not via the PKA-dependent pathway. These results provided direct preclinical evidence that puerarin prolonged APD via its inhibitory effect upon Kv7.1 and IKs, contributing to a better understanding the mechanism of puerarin cardioprotection in the treatment of cardiovascular diseases
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