974 resultados para Phenomena and statements


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The interaction of 4-nerolidylcatechol (4-NRC), a potent antioxidant agent, and 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was investigated by the solubility method using Fourier transform infrared (FTIR) methods in addition to UV-Vis, (1)H-nuclear magnetic resonance (NMR) spectroscopy and molecular modeling. The inclusion complexes were prepared using grinding, kneading and freeze-drying methods. According to phase solubility studies in water a B(S)-type diagram was found, displaying a stoichiometry complexation of 2:1 (drug:host) and stability constant of 6494 +/- A 837 M(-1). Stoichiometry was established by the UV spectrophotometer using Job`s plot method and, also confirmed by molecular modeling. Data from (1)H-NMR, and FTIR, experiments also provided formation evidence of an inclusion complex between 4-NRC and HP-beta-CD. 4-NRC complexation indeed led to higher drug solubility and stability which could probably be useful to improve its biological properties and make it available to oral administration and topical formulations.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Frequent advances in medical technologies have brought fonh many innovative treatments that allow medical teams to treal many patients with grave illness and serious trauma who would have died only a few years earlier. These changes have given some patients a second chance at life, but for others. these new treatments have merely prolonged their dying. Instead of dying relatively painlessly, these unfortunate patients often suffer from painful tenninal illnesses or exist in a comatose state that robs them of their dignity, since they cannot survive without advanced and often dehumanizing forms of treatment. Due to many of these concerns, euthanasia has become a central issue in medical ethics. Additionally, the debate is impacted by those who believe that patients have the right make choices about the method and timing of their deaths. Euthanasia is defined as a deliberate act by a physician to hasten the death of a patient, whether through active methods such as an injection of morphine, or through the withdrawal of advanced forms of medical care, for reasons of mercy because of a medical condition that they have. This study explores the question of whether euthanasia is an ethical practice and, as determined by ethical theories and professional codes of ethics, whether the physician is allowed to provide the means to give the patient a path to a "good death," rather than one filled with physical and mental suffering. The paper also asks if there is a relevant moral difference between the active and passive forms of euthanasia and seeks to define requirements to ensure fully voluntary decision making through an evaluation of the factors necessary to produce fully informed consent. Additionally, the proper treatments for patients who suffer from painful terminal illnesses, those who exist in persistent vegetative states and infants born with many diverse medical problems are examined. The ultimate conclusions that are reached in the paper are that euthanasia is an ethical practice in certain specific circumstances for patients who have a very low quality of life due to pain, illness or serious mental deficits as a result of irreversible coma, persistent vegetative state or end-stage clinical dementia. This is defended by the fact that the rights of the patient to determine his or her own fate and to autonomously decide the way that he or she dies are paramount to all other factors in decisions of life and death. There are also circumstances where decisions can be made by health care teams in conjunction with the family to hasten the deaths of incompetent patients when continued existence is clearly not in their best interest, as is the case of infants who are born with serious physical anomalies, who are either 'born dying' or have no prospect for a life that is of a reasonable quality. I have rejected the distinction between active and passive methods of euthanasia and have instead chosen to focus on the intentions of the treating physician and the voluntary nature of the patient's request. When applied in equivalent circumstances, active and passive methods of euthanasia produce the same effects, and if the choice to hasten the death of the patient is ethical, then the use of either method can be accepted. The use of active methods of euthanasia and active forms of withdrawal of life support, such as the removal of a respirator are both conscious decisions to end the life of the patient and both bring death within a short period of time. It is false to maintain a distinction that believes that one is active killing. whereas the other form only allows nature to take it's course. Both are conscious choices to hasten the patient's death and should be evaluated as such. Additionally, through an examination of the Hippocratic Oath, and statements made by the American Medical Association and the American College of physicians, it can be shown that the ideals that the medical profession maintains and the respect for the interests of the patient that it holds allows the physician to give aid to patients who wish to choose death as an alternative to continued suffering. The physician is also allowed to and in some circumstances, is morally required, to help dying patients whether through active or passive forms of euthanasia or through assisted suicide. Euthanasia is a difficult topic to think about, but in the end, we should support the choice that respects the patient's autonomous choice or clear best interest and the respect that we have for their dignity and personal worth.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A close scrutiny of a sample of the works of the chief protagonists of the Public Choice "Revolution" is a revelation. Endless cases of contradiction, basic assumptions and motivations which have much in common with Marxism are detected. Knight's legitimizing role is an illusion (not to say a fraud). Knight's affinities with the institutionalists are established. Distinction is made between the contradictions assignable to the Ricardian Vice and unavoidable contradictions arising from complexities in the phenomena and partiality in the theories. The languages of abstract, applied an professional economics are identified and critically examined.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Trabalho apresentado no Congresso Nacional de Matemática Aplicada à Indústria, 18 a 21 de novembro de 2014, Caldas Novas - Goiás

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Schistosomiasis is still an endemic disease in many regions, with 250 million people infected with Schistosoma and about 500,000 deaths per year. Praziquantel (PZQ) is the drug of choice for schistosomiasis treatment, however it is classified as Class II in the Biopharmaceutics Classification System, as its low solubility hinders its performance in biological systems. The use of cyclodextrins is a useful tool to increase the solubility and bioavailability of drugs. The aim of this work was to prepare an inclusion compound of PZQ and methyl-beta-cyclodextrin (MeCD), perform its physico-chemical characterization, and explore its in vitro cytotoxicity. SEM showed a change of the morphological characteristics of PZQ:MeCD crystals, and IR data supported this finding, with changes after interaction with MeCD including effects on the C-H of the aromatic ring, observed at 758 cm(-1). Differential scanning calorimetry measurements revealed that complexation occurred in a 1:1 molar ratio, as evidenced by the lack of a PZQ transition temperature after inclusion into the MeCD cavity. In solution, the PZQ UV spectrum profile in the presence of MeCD was comparable to the PZQ spectrum in a hydrophobic solvent. Phase solubility diagrams showed that there was a 5.5-fold increase in PZQ solubility, and were indicative of a type A(L) isotherm, that was used to determine an association constant (K(a)) of 140.8 M(-1). No cytotoxicity of the PZQ:MeCD inclusion compound was observed in tests using 3T3 cells. The results suggest that the association of PZQ with MeCD could be a good alternative for the treatment of schistosomiasis.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The jeju is a teleost fish with bimodal respiration that utilizes a modified swim bladder as an air-breathing organ (ABO). Like all air-breathing fish studied to date, jeju exhibit pronounced changes in heart rate (f(H)) during air-breathing events, and it is believed that these may facilitate oxygen uptake (M-O2) from the ABO. The current study employed power spectral analysis (PSA) of f(H) patterns, coupled with instantaneous respirometry, to investigate the autonomic control of these phenomena and their functional significance for the efficacy of air breathing. The jeju obtained less than 5% of total M-O2 (M-tO2) from air breathing in normoxia at 26 degrees C, and PSA of beat-to-beat variability in fH revealed a pattern similar to that of unimodal water-breathing fish. In deep aquatic hypoxia (water P-O2=1 kPa) the jeju increased the frequency of air breathing (f(AB)) tenfold and maintained M-tO2 unchanged from normoxia. This was associated with a significant increase in heart rate variability (HRV), each air breath (AB) being preceded by a brief bradycardia and then followed by a brief tachycardia. These f(H) changes are qualitatively similar to those associated with breathing in unimodal air-breathing vertebrates. Within 20 heartbeats after the AB, however, a beat-to-beat variability in f(H) typical of water-breathing fish was re-established. Pharmacological blockade revealed that both adrenergic and cholinergic tone increased simultaneously prior to each AB, and then decreased after it. However, modulation of inhibitory cholinergic tone was responsible for the major proportion of HRV, including the precise beat-to-beat modulation of f(H) around each AB. Pharmacological blockade of all variations in f(H) associated with air breathing in deep hypoxia did not, however, have a significant effect upon f(AB) or the regulation of M-tO2. Thus, the functional significance of the profound HRV during air breathing remains a mystery.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The erbium-based manganite ErMnO3 has been partially substituted at the manganese site by the transition-metal elements Ni and Co. The perovskite orthorhombic structure is found from x(Ni) = 0.2-0.5 in the nickel-based solid solution ErNixMn1-xO3, while it can be extended up to x(Co) = 0.7 in the case of cobalt, provided that the synthesis is performed under oxygenation conditions to favor the presence of Co3+. Presence of different magnetic entities (i.e., Er3+, Ni2+, Co2+, Co3+, Mn3+, and Mn4+) leads to quite unusual magnetic properties, characterized by the coexistence of antiferromagnetic and ferromagnetic interactions. In ErNixMn1-xO3, a critical concentration x(crit)(Ni) = 1/3 separates two regimes: spin-canted AF interactions predominate at x < x(crit), while the ferromagnetic behavior is enhanced for x > x(crit). Spin reversal phenomena are present both in the nickel- and cobalt-based compounds. A phenomenological model based on two interacting sublattices, coupled by an antiferromagnetic exchange interaction, explains the inversion of the overall magnetic moment at low temperatures. In this model, the ferromagnetic transition-metal lattice, which orders at T-c, creates a strong local field at the erbium site, polarizing the Er moments in a direction opposite to the applied field. At low temperatures, when the contribution of the paramagnetic erbium sublattice, which varies as T-1, gets larger than the ferromagnetic contribution, the total magnetic moment changes its sign, leading to an overall ferrimagnetic state. The half-substituted compound ErCo0.50Mn0.50O3 was studied in detail, since the magnetization loops present two well-identified anomalies: an intersection of the magnetization branches at low fields, and magnetization jumps at high fields. The influence of the oxidizing conditions was studied in other compositions close to the 50/50 = Mn/Co substitution rate. These anomalies are clearly connected to the spin inversion phenomena and to the simultaneous presence of Co2+ and Co3+ magnetic moments. Dynamical aspects should be considered to well identify the high-field anomaly, since it depends on the magnetic field sweep rate. (C) 2006 Elsevier B.V. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

90.00% 90.00%

Publicador:

Resumo:

To study the influence of Ga addition on photoinduced effect, GaGeS glasses with constant atomic ratio S/Ge = 2.6 have been prepared. Using Raman spectroscopy, we have reported the effect of Ga on the structural behavior of these glasses. An increase of the glass transition temperature T(g), the linear refractive index and the density have been observed with increasing gallium content. The photoinduced phenomena have been examined through the influence of time exposure and power density, when exposed to above light bandgap (3.53 eV). The correlation between photoinduced phenomena and Ga content in such glasses are shown hereby. (C) 2009 Elsevier B.V. All rights reserved.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In this study, the relationship between child malnutrition, depression, anxiety and other maternal socio-demographic variables was investigated in mothers of malnourished (MD) and eutrophic (ME) children. The causes attributed by mothers to malnutrition were also studied. Ten mothers from each group, with children aged from 11 months to three years and who were users of primary health care units, participated in the study. They answered Beck depression and anxiety inventory, a questionnaire on vital events and an open question concerning the causes of malnutrition. The evaluation instruments were corrected according to proper guidelines and comparative analyses between the groups were performed. The answers to the open question were qualitatively evaluated, submitted to content analysis. The mothers in the two groups were nearly 30 years old or older. They had a steady partner and were subject to very similar life conditions. They had attended school for 5.5 years and were housewives or worked in low-income jobs. Concerning mental health indicators, a significantly larger number of mothers in the MM group showed depression indicators when compared to mothers in the EM group. Most mothers attributed malnutrition to biological factors or to the lack of maternal care, with more moralist statements in the EM group, and statements filled with guilt in MM. Results suggest that in order to fight malnutrition, in addition to nutritional interventions, it is necessary to heed attention to maternal socio-emotional issues.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Objective: This study investigated the effect of experimental photopolymerized coatings, containing zwitterionic or hydrophilic monomers, on the hydrophobicity of a denture base acrylic resin and on Candida albicans adhesion. Methods: Acrylic specimens were prepared with rough and smooth surfaces and were either left untreated (control) or coated with one of the following experimental coatings: 2-hydroxyethyl methacrylate (HE); 3-hydroxypropyl methacrylate (HP); and 2-trimethylammonium ethyl methacrylate chloride (T); and sulfobetaine methacrylate (S). The concentrations of these constituent monomers were 25%, 30% or 35%. Half of the specimens in each group (control and experimentals) were coated with saliva and the other half remained uncoated. The surface free energy of all specimens was measured, regardless of the experimental condition. C. albicans adhesion was evaluated for all specimens, both saliva conditioned and unconditioned. The adhesion test was performed by incubating specimens in C. albicans suspensions (1 × 10 7 cell/mL) at 37 °C for 90 min. The number of adhered yeasts were evaluated by XTT (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]-5-[{phenylamino} carbonyl]-2H-tetrazolium-hydroxide) method. Results: For rough surfaces, coatings S (30 or 35%) and HP (30%) resulted in lower absorbance values compared to control. These coatings exhibited more hydrophilic surfaces than the control group. Roughness increased the adhesion only in the control group, and saliva did not influence the adhesion. The photoelectron spectroscopy analysis (XPS) confirmed the chemical changes of the experimental specimens, particularly for HP and S coatings. Conclusions: S and HP coatings reduced significantly the adhesion of C. albicans to the acrylic resin and could be considered as a potential preventive treatment for denture stomatitis. © 2012 Elsevier Ltd.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The use of chemically modified starches is widely accepted in various industries, with several applications. In this research, natural cassava starch granules were treated with standard sodium hypochlorite solution at 0.8, 2.0, and 5.0 g Cl/100 g starch. The native and modified starch samples were investigated by means of the following techniques: simultaneous thermogravimetry-differential thermal analysis, which allowed us to verify the thermal decomposition associated with endothermic or exothermic phenomena; and differential scanning calorimetry that was used to determine gelatinization enthalpy as well as the rapid viscoamylographic analysis that provided the pasting temperature and viscosity. By means of non-contact-atomic force microscopy method and X-ray powder patterns diffractometry, it was possible to observe the surface morphology, topography of starch granules, and alterations in the granules' crystallinity. © 2012 Akadémiai Kiadó, Budapest, Hungary.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In experimental psychopathology, construct validity is usually enhanced by addressing theories from other fields in its nomological network. In the field of anxiety research, this construct is related to antipredator behavior, conserved across phylogeny in its functions and neural basis, but not necessarily on its topography. Even though the relations between behavioral models of anxiety and statements from behavioral ecology and evolutionary biology are commonly made in anxiety research, these are rarely tested, at least explicitly. However, in order to increase construct validity in experimental anxiety, testing predictions from those theories is highly desirable. This article discusses these questions, suggesting a few ways in which behavioral ecological and evolutionary hypotheses of anxiety-like behavior may be tested.