407 research outputs found
Coronary Arterial Circulation in the Bantu
Author Institution: Laboratory of Human Anatomy, Department of Normal Morphology, University of Luanda, AngolaHearts from 710 adult Bantus of either sex born in Angola and aged between 25 and 68 years were studied. The authors examined the morphological pattern of the coronary arteries and compared them to hearts from Caucasians. An attempt is made to relate the anatomical structure to the reduced incidence of myocardial infarction in the Bantu population. One possible explanation is that a microcirculatory adaptation to physiological conditions could act as a defense mechanism. It is evident that the intraparietal branches of the coronary artery present a greater internal diameter than those found in Caucasian hearts
O epitélio respiratório em ratos Wistar
ABSTRACTMorphofunctional changes of respiratory epithelia became the object of intense study in Wistar rats after previous research showed that occupationally-simulated exposure to low frequency noise (≤500Hz, including infrasound) induced irreversible lesions in these tissues. Aspects of normal respiratory epithelia in rats are lacking in the literature, and are the object of this report. Ten Wistar rats were kept in silence, fed standard rat food, and had unrestrained access to water (treated in accordance with 86/609/CE). The animals were sacrificed at 3.5months of age, and respiratory epithelial fragments were excised and prepared for scanning (SEM) and transmission (TEM) electron microscopy. Brush cells (BC) were frequently observed with TEM, but with SEM they were often covered by the cilia of neighbouring cells. BC were always observed at the center of a ring of secretory cells (SC), in a rosetta-shaped formation. In TEM, the microvilli of SC surrounding the BC were uniform, and had the same density and shape in all cells. Multivesicular bodies were identified in areas within the BC. Formation and budding of vesicles from ciliary plasma membranes and from BC microvilli were frequently observed in both TEM and SEM. These data contribute to the understanding of the BC function.REV PORT PNEUMOL 2003; IX (5): 381-38
Hybrid process for genotoxics removal from active pharmaceutical ingredients combining organic solvent nanofiltration with polybenzimidazole adsorbents
Active pharmaceutical ingredients (APIs), as most of medicines, are obtained through chemical synthesis, using highly reactive reagents and usually, low levels of reagents, fractions of catalysts, or by-products are present in the final API or drug product as impurities. Some of these impurities have unwanted toxicities, including genotoxicity and carcinogenicity, and therefore related API administration risks for patient’s health has become an increasing concern of pharmaceutical companies, regulatory authorities, patients and doctors. European Medicines Agency (EMA) was the first agency to implement guidelines to control genotoxic impurities (GTIs), followed by the Food and Drug Administration (FDA). Both authorities agreed on setting as “Threshold of Toxicological Concern” (TTC) a limit at 1.5 micrograms per day for known and potential carcinogens [1,2]. Herein we report an approach based on the thermal treatment of a polybenzimidazole polymer providing novel adsorbent properties for genotoxic removal to purify API post-reaction streams. These novel adsorbents were tested for GTIs, such as methyl p-toluenesulfonate, p-toluenesulfonic acid, 4,4-dimethylamino pyridine and ethanesulfonyl chloride, from API solutions of Mometasone furoate (Meta). The current work will present a strategy of a hybrid process combining organic solvent nanofiltration (OSN) of API post-reaction streams with the adsorbers studied. The aim to include an adsorber stage, after the OSN operation, is to polish the retentate API solution for further purification or/and recovery of API lost through the permeate stream. Results will illustrate process efficiency gains.
References
[1] Teasdale A.; Elder D.; Chang S. J.; Wang S.; Thompson R.; Benz N.; Flores I. H. S., Org. Process Res. Dev. 17, 2013, 221-230.
[2] EMEA Guidelines on the “Limits on Genotoxic Impurities”, EMEA/CHMP/QWP/251344/2006, 2006.
Acknowledgements: We thank financial support from Fundação para a Ciência e Tecnologia (FCT) through the Project SelectHost (PTDC/QEQ-PRS/4157/2014) and iBB-Institute for Bioengineering and Biosciences (UID/BIO/04565/2013), from Programa Operacional Regional de Lisboa 2020 (Lisboa-01-0145-FEDER-007317) and from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq – Brasil). We thank to Hovione PharmaScience Ltd for supplying the API and technical know-how
A Computer Simulation of the Nitinol Thermal Expansion under Fast Varying Working Conditions
We discuss the setup of a simulation on ANSYS to predict the thermal expansion of parts made of Nitinol. A simulation is justified for working conditions in which the part heating is not ho-mogeneous originating a temperature gradient across the part section such that an analytical estimate for the part expansion cannot be calculated. We apply the simulation to the topological optimization of a square section geometry and a bullet geometry for water assisted injection molding. For the topo-logical optimization we consider as parameter the wall thickness and consider both the cases of fast varying temperature and fast varying temperature and pressure.info:eu-repo/semantics/publishedVersio
Left Ventricular Diastolic Function in Type 2 Diabetes Mellitus and the Association With Coronary Artery Calcium Score: A Cardiac MRI Study
OBJECTIVE:
The purpose of this study was to compare cardiac MRI-derived parameters of left ventricular (LV) diastolic function between uncomplicated type 2 diabetes mellitus (DM2) and normoglycemic control subjects and to evaluate whether these parameters of LV diastolic function are related to coronary atherosclerosis.
SUBJECTS AND METHODS:
We prospectively studied 41 subjects with DM2 and 21 normoglycemic control subjects (30 women and 32 men; mean age, 57.2 ± 7.1 [SD] years) with no evidence of overt cardiovascular disease. We used cardiac MRI to measure LV volumes, LV peak filling rate (PFR), and transmitral flow and CT to determine coronary artery calcium scores.
RESULTS:
Absolute values of the peak filling rate (PFR) were significantly lower in DM2 patients than in control subjects (mean ± SD, 293.2 ± 51.7 vs 375.7 ± 102.8 mL/s, respectively; p < 0.001). Mitral peak E velocities (mean ± SD, 42.8 ± 10.7 vs 48.8 ± 10.4 cm/s; p = 0.040) and peak E velocity-to-peak A velocity ratios (0.88 ± 0.3 vs 1.1 ± 0.3; p = 0.002) were also lower in DM2 patients compared with control subjects. DM2 patients with coronary artery calcification showed a lower PFR normalized to stroke volume (SV) (mean ± SD, 4.4 ± 1.0 vs 5.3 ± 1.4, respectively; p = 0.038) and lower mitral peak E velocities (40.1 ± 11.3 vs 48.0 ± 7.3 cm/s; p = 0.024) than DM2 patients without coronary calcification. PFR normalized to SV was independently associated with the presence of coronary artery calcification (β = -1.5, p = 0.005).
CONCLUSION:
DM2 decreases cardiovascular MRI-derived parameters of LV diastolic function. Patients with DM2 and coronary atherosclerosis show a more impaired LV diastolic function than patients without coronary atherosclerosis
Paragenetic positioning of PGE in mafic and ultramafic rocks of Cabeço de Vide – Alter do Chão Igneous Complex
A expressão mineralógica de platinóides nas rochas máficas e ultramáficas de Cabeço de Vide (Complexo Ígneo de Alter do Chão), ocorre em dois episódios de deposição primária que se relacionam com os estádios de fraccionação dunítico a pós-dunítico (estibiopaladinite e froodite) e lherzolítico, equivalente ao início da fraccionação de sulfuretos (auricuprite e ouro). Os minerais tipomórficos subsequentes (sperrylite e
arsenopaladinite) representam o reposicionamento epigenético associado à serpentinização.PGE mineralisation in mafic and ultramafic rocks of Cabeço de Vide (Alter do Chão Igneous Complex) results from two primary deposition events related to progressive fraccionation at dunitic to post-dunitic stage,
represented by stibiopaladinite and froodite, and at lherzolitic stage, coupled by sulphide segregation, causing auricuprite and gold crystallization. Subsequent PGM (sperrylite and arsenopaladinite) must result from serpentinization repositioning
Estratégia de Desenvolvimento de uma Solução Circular de Embalagem Alimentar: um Estudo do Mercado e do Consumidor
A relação entre o perfil comunicacional dos treinadores e a autoconfiança dos atletas
A comunicação do treinador é frequentemente referida como uma das principais fontes de autoconfiança de um atleta. No entanto, é um fenómeno ainda pouco estudado com adultos (Weight et al., 2020), especialmente utilizando o método quantitativo. Assim, o presente estudo teve como objetivo principal estudar a relação entre o perfil comunicacional dos treinadores e os níveis de confiança no desporto dos seus atletas, comunicação esta avaliada através do Sistema de Avaliação de Comportamentos de Comunicação (SACC; Gomes et al., 2020). A amostra foi constituída por uma equipa de hóquei em patins de nível sénior e o seu treinador. Foram gravados seis jogos, sendo a comunicação verbal do treinador codificada através de uma grelha de observação. No final de cada jogo, os atletas avaliavam também esta comunicação do treinador e a sua autoconfiança, através de medidas de autorrelato. O treinador apresentou predominantemente comportamentos comunicacionais positivos. Os comportamentos comunicacionais exibidos pelo treinador medidos através da grelha de codificação não predisseram a autoconfiança dos atletas. Não obstante, a avaliação que os atletas fizeram dessa comunicação é preditor da sua autoconfiança: quanto mais percecionam que o treinador exibe comportamentos reativos (positivos e negativos), maior a sua autoconfiança.A coach’s communication is often referred to as one of the main sources of a players’ self-confidence. However, it is still a phenomenon with little research on adults (Weight et al., 2020). Thus, the present study had as its main goal to study the relationship between a coach’s communicational profile and the confidence levels of their athletes, evaluating that communication through the Communication Behaviors Evaluation System (CBES; Gomes et al., 2020). The sample included a team of adult roller-skating hockey players and their coach. Six games were recorded, as the coach’s verbal communication was coded using an observation grid. At the end of each game, athletes would also evaluate coach’s and their confidence levels, through self-report measures. The coach predominantly displayed positive communication behaviors. However, communication behaviors measured using the observation grid did not predict players’ self-confidence. Nevertheless, the evaluation players made of that communication was a predictor of their self-confidence: the more they perceive the coach to display reactive behaviors (both positive and negative), the higher their self-confidence
Electrical Stimulation Optimization in Bioreactors for Tissue Engineering Applications
We review here the current research status on bioreactors for tissue engineering with cell electrical stimulation. Depending on the cell types, electrical stimulation has distinct objectives: 1) being employed both to mimic and enhance endogenous electricity measured in the natural regeneration of living organisms and 2) to mimic strain working conditions for contractible tissues (for instance muscle and cardiac tissues). Understanding the distinct parameters involved in electrical stimulation is crucial to optimize its application. The results presented in the literature and reviewed here reveal that the application of electrical stimulation can be essential for tissue engineering
applications.info:eu-repo/semantics/publishedVersio
Vibroacoustic disease II: The biological and acoustical basis of low frequency noise induced pathology
Proceedings Institute of Acoustics (UK); vol. 25, nº2, p. 72-78
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