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Hyaluronic acid (HA) and gelatin (Gel) are major components of the extracellular matrix of different tissues, and thus are largely appealing for the construction of hybrid hydrogels to combine the favorable characteristics of each biopolymer, such as the gel adhesiveness of Gel and the better mechanical strength of HA, respectively. However, despite previous studies conducted so far, the relationship between composition and scaffold structure and physico-chemical properties has not been completely and systematically established. In this work, pure and hybrid hydrogels of methacroyl-modified HA (HAMA) and Gel (GelMA) were prepared by UV photopolymerization and an extensive characterization was done to elucidate such correlations. Methacrylation degrees of ca. 40% and 11% for GelMA and HAMA, respectively, were obtained, which allows to improve the hydrogels' mechanical properties. Hybrid GelMA/HAMA hydrogels were stiffer, with elastic modulus up to ca. 30 kPa, and porous (up to 91%) compared with pure GelMA ones at similar GelMA concentrations thanks to the interaction between HAMA and GelMA chains in the polymeric matrix. The progressive presence of HAMA gave rise to scaffolds with more disorganized, stiffer, and less porous structures owing to the net increase of mass in the hydrogel compositions. HAMA also made hybrid hydrogels more swellable and resistant to collagenase biodegradation. Hence, the suitable choice of polymeric composition allows to regulate the hydrogels´ physical properties to look for the most optimal characteristics required for the intended tissue engineering application.
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Materiais Biocompatíveis/química , Gelatina/química , Ácido Hialurônico/química , Hidrogéis/química , Metacrilatos/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , Humanos , Polímeros/químicaRESUMO
BACKGROUND: Decrease in oral intake, weight loss, and muscular weakness in the last phases of a terminal illness, particularly in the context of the cachexia-anorexia syndrome, can be an important source of anxiety for the triad of patient, family, and health staff. METHODS: The present literature review examines the emotional impact of reduced oral intake as well as perceptions and attitudes toward assisted nutrition and hydration for terminally ill patients(1) at the end of life, among patients, family, and health care staff. We have identified the ways in which emotional and cultural factors influence decision-making about assisted nutrition and hydration. RESULTS: Lack of information and misperceptions of medically assisted nutrition and hydration can play a predominant role in the decision to begin or suspend nutritional or hydration support. CONCLUSIONS: Our literature review reveals that these social, emotional, and clinical misperception elements should be considered in the decision-making processes to help the triad develop functional forms of care at this final stage of life. Copyright © 2011 John Wiley & Sons, Ltd.
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Hidratação , Neoplasias/terapia , Estado Nutricional , Cuidados Paliativos/métodos , Assistência Terminal/psicologia , Atitude do Pessoal de Saúde , Atitude Frente a Saúde , Tomada de Decisões , Emoções , Família/psicologia , Humanos , Neoplasias/psicologia , Cuidados Paliativos/psicologia , Participação do Paciente , PercepçãoRESUMO
The detailed temperature-composition phase diagram of the P103/water system in the dilute and semidilute regions is reported here using density and ultrasound velocity measurements, differential scanning calorimetry (DSC), rheometry and dynamic (DLS) and static light scattering (SLS). These techniques allow a precise determination of the critical micellar temperature (CMT), the sphere-to-rod micellar transition temperature (GMT) and the cloud point temperature (CPT) as a function of concentration. DLS and SLS measurements were employed to gain information on unimers and aggregate sizes and on the transition from spherical-to-rod micelles.
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Perhaps one of the main ethical dilemmas physicians face in cancer medicine is the question of truthfulness with terminally ill cancer patients. Reluctance to share the truth with the patient about his or her diagnosis and/or prognosis is frequently associated with cultural pressures. Based on two cases, the authors illustrate how ethical analysis can help in solving dilemmas related to truth disclosure to terminally ill cancer patients and their families. A personalist approach reveals that the often-adduced conflict between nonmaleficence/beneficence and autonomy with regard to truth telling originates from a narrow understanding of the concept of autonomy. This confrontation is, therefore, more apparent than real. A brief review of the main ethical systems and the results of their application to clinical decision-making follow the discussion of the cases.
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Carcinoma Pulmonar de Células não Pequenas/psicologia , Diversidade Cultural , Tomada de Decisões , Ética Clínica , Ética Médica , Neoplasias Pulmonares/psicologia , Cuidados Paliativos/normas , Revelação da Verdade , Idoso , Carcinoma Pulmonar de Células não Pequenas/terapia , Comunicação , Egito , Feminino , Humanos , Neoplasias Pulmonares/terapia , Masculino , Pessoa de Meia-Idade , Relações Médico-Paciente , América do Sul , Estados UnidosRESUMO
Hazard analyses of food preparation practices were conducted in three households in a new settlement in the rocky, dusty hillsides at the outskirts of Lima, Peru. These analyses consisted of watching all steps of preparation, recording temperatures throughout these steps, and collecting samples of the food and testing them for common foodborne pathogens and indicator organisms. The residents had migrated from different regions of the country; consequently, they prepared different foods. These included soya cereal, milk formula, rice and carrots for feeding a baby who had diarrhea, soups, mashed potatoes with spinach, carrot and beet salad, cow's foot soup, beans, rice and a mixture of beans and rice. The temperatures attained were high enough to kill vegetative forms of foodborne pathogens, but not their spores. During the interval between cooking in the morning and serving at either lunch or supper time, foods were held either on unheated ranges or in unheated ovens. This interval was long enough to permit some bacterial multiplication, but apparently not to massive quantities. Just before the evening meal, foods were reheated to temperatures that usually exceeded 70°C. Rice, however, was either served cold or if reheated, the center temperature rose a few degrees only. Critical control points for preparation of family meals are cooking, holding between cooking and serving, and reheating. Critical control points for milk formula for babies are using recently-boiled water for the formula, cleaning and boiling bottles and nipples, and, of particular importance, time of holding at room temperature.