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1.
Intensive Crit Care Nurs ; 68: 103131, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34456109

RESUMO

BACKGROUND: The way health care professionals touch patients and relatives in the intensive care unit plays a significant role. A negative feeling can be caused by being touched in the wrong way, this is why a holistic approach with respect for the patient is important for the ability to make the patient and their relatives feel secure, avoiding unnecessary suffering. AIM: The aim of the study was to describe the meaning of caring touch that is given in the ICU from the health care professionals perspective. METHOD: Qualitative interview study with health care professionals in the intensive care unit, analysed using inductive content analysis, resulting in two themes and four main categories. FINDINGS: Two themes emerged: Imperative touch and emotional touch and four main categories: touch as a natural tool, create a prerequisite for touch, empathetic touch and conversant touch. CONCLUSION: Caring touch can be used as a natural tool in the daily work in order to bring comfort and calm to the patient in the intensive care unit.


Assuntos
Unidades de Terapia Intensiva , Tato , Atitude do Pessoal de Saúde , Pessoal de Saúde , Humanos , Pesquisa Qualitativa
2.
Adv Colloid Interface Sci ; 251: 1-25, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29287789

RESUMO

A wide range of isoelectric points (IEPs) has been reported in the literature for sapphire-c (α-alumina), also referred to as basal plane, (001) or (0001), single crystals. Interestingly, the available data suggest that the variation of IEPs is comparable to the range of IEPs encountered for particles, although single crystals should be much better defined in terms of surface structure. One explanation for the range of IEPs might be the obvious danger of contaminating the small surface areas of single crystal samples while exposing them to comparatively large solution reservoirs. Literature suggests that factors like origin of the sample, sample treatment or the method of investigation all have an influence on the surfaces and it is difficult to clearly separate the respective, individual effects. In the present study, we investigate cause-effect relationships to better understand the individual effects. The reference IEP of our samples is between 4 and 4.5. High temperature treatment tends to decrease the IEP of sapphire-c as does UV treatment. Increasing the initial miscut (i.e. the divergence from the expected orientation of the crystal) tends to increase the IEP as does plasma cleaning, which can be understood assuming that the surfaces have become less hydrophobic due to the presence of more and/or larger steps with increasing miscut or due to amorphisation of the surface caused by plasma cleaning. Pre-treatment at very high pH caused an increase in the IEP. Surface treatments that led to IEPs different from the stable value of reference samples typically resulted in surfaces that were strongly affected by subsequent exposure to water. The streaming potential data appear to relax to the reference sample behavior after a period of time of water exposure. Combination of the zeta-potential measurements with AFM investigations support the idea that atomically smooth surfaces exhibit lower IEPs, while rougher surfaces (roughness on the order of nanometers) result in higher IEPs compared to reference samples. Two supplementary investigations resulted in either surprising or ambiguous results. On very rough surfaces (roughness on the order of micrometers) the IEP lowered compared to the reference sample with nanometer-scale roughness and transient behavior of the rough surfaces was observed. Furthermore, differences in the IEP as obtained from streaming potential and static colloid adhesion measurements may suggest that hydrodynamics play a role in streaming potential experiments. We finally relate surface diffraction data from previous studies to possible interpretations of our electrokinetic data to corroborate the presence of a water film that can explain the low IEP. Calculations show that the surface diffraction data are in line with the presence of a water film, however, they do not allow to unambiguously resolve critical features of this film which might explain the observed surface chemical characteristics like the dangling OH-bond reported in sum frequency generation studies. A broad literature review on properties of related surfaces shows that the presence of such water films could in many cases affect the interfacial properties. Persistence or not of the water film can be crucial. The presence of the water film can in principle affect important processes like ice-nucleation, wetting behavior, electric charging, etc.

3.
Planet Space Sci ; 43(1-2): 3-10, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-11538435

RESUMO

A simple steady-state photochemical model is developed in order to determine typical molecular oxygen concentrations for a comprehensive range of primitive abiotic atmospheres. Carbon dioxide is assumed to be the dominant constituent in these atmospheres since CO2 photodissociation may potentially result in the enhancement of the O2 partial pressure. The respective effects of the H2O content, temperature, eddy diffusion coefficient and UV flux on the results are investigated. It is shown that for any pressure at the surface, the partial pressure of molecular oxygen does not exceed 10 mbar. The peculiar case of a runaway greenhouse which has possibly taken place on Venus is qualitatively envisaged. Although O2 is basically absent in the present Venus atmosphere, a transient presence in a primitive stage cannot be ruled out. Possible mechanisms for O2 removal in such an atmosphere are reviewed. At the present stage, we think that the detection of large O2 amounts would be at least a good clue for the presence of life on an extrasolar planet.


Assuntos
Atmosfera , Meio Ambiente Extraterreno , Modelos Químicos , Oxigênio/análise , Dióxido de Carbono/análise , Exobiologia , Efeito Estufa , Marte , Origem da Vida , Oxigênio/química , Fotoquímica , Vênus
4.
J Biomed Mater Res ; 27(7): 941-8, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8360220

RESUMO

Five glass compositions in or near the bioactive region in the system SiO2-Na2O-CaO-P2O5-Al2O3-B2O3 were studied in vitro by immersion in Tris buffer. The Si concentration can be taken as a measure of the amount of dissolved glass, whereas the Na concentration can be used to estimate the thickness of the Si-rich (Si gel) layer. Upon immersing a bioactive glass into Tris buffer, a surface layer of a few micrometer thickness is dissolved during the first 8 h. During the first few hours of immersion, the rate of dissolution of the glass network is equal to or exceeds that of the growth of the Si-rich layer. If the glass contains Al2O3, most of the aluminum that would be released due to dissolution of the silica network is enriched in the Si-rich surface layer that forms due to leaching. Al2O3 is not only bonded by the Si gel but also interferes with formation of calcium phosphate.


Assuntos
Óxido de Alumínio/química , Vidro/química , Silício/análise , Sódio/análise , Solubilidade , Trometamina
5.
Icarus ; 98(2): 254-70, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11539361

RESUMO

Global Martian atmospheric results derived from the infrared imaging spectrometer ISM flown aboard the Phobos 2 Soviet spacecraft are presented. Over low altitude regions the expected CO mixing ratio of (8 +/- 3) x 10(-4) is measured. Variations of the 2.35-micrometers feature are inconsistent with this value over the Great Martian Volcanoes. If the 2.35-micrometers band is entirely attributable to carbon monoxide, the CO mixing ratio is typically depleted by a factor of 3 over these high altitude areas. Orography should play a major role in the existence of this CO "hole." If, however, these spectral variations at 2.35 micrometers are due to the surface composition, the fraction of the surface covered by the responsible mineral must smoothly decrease as the surface elevation decreases. This phenomenon implies a strong interaction between the surface and the atmosphere for the Great Martian Volcanoes. Diurnal behavior and latitudinal variations of water vapor are globally consistent with Viking measurements. During the Phobos observations, the water vapor amounts over the bright equatorial regions range around 11 pr-micrometers during the day. These amounts are slightly larger than those inferred from 1976 to 1979. The lack of global dust storms during 1988-1989 could explain the enhancement of H2O in the atmosphere.


Assuntos
Atmosfera/análise , Dióxido de Carbono/química , Monóxido de Carbono/química , Meio Ambiente Extraterreno , Marte , Espectrofotometria Infravermelho/instrumentação , Água/química , Astronomia/instrumentação , Astronomia/métodos , Pressão Atmosférica , Poeira , Modelos Teóricos , Fotoquímica , Astronave/instrumentação , Espectrofotometria Infravermelho/métodos , Luz Solar , Temperatura
6.
J Colloid Interface Sci ; 206(1): 252-266, 1998 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-9761651

RESUMO

This work is concerned with the adsorption of o-phthalate (1,2-benzenedicarboxylate) at the water-metal (hydr)oxide interface. Previously published infrared spectroscopic, potentiometric, and adsorption data characterizing the boehmite (gamma-AlOOH) system are compared with new data collected for o-phthalate adsorption on aged gamma-Al2O3 and goethite (alpha-FeOOH). The study focuses on identifying bonding mechanisms, stoichiometries, and stabilities of the formed complexes, and comparing these among the three systems. Furthermore, the effects of ionic strength and composition of the ionic medium are investigated. The infrared spectroscopic data provided direct, molecular-level evidence for the existence of two dominating surface complexes on all three solids. One was shown to be a deprotonated outer-sphere species and the other was an inner-sphere surface complex. The inner-sphere complexes on the three solids were structurally related, and they were tentatively assigned to a mononuclear, chelating structure involving both carboxylate groups. The outer-sphere complexes were shown to increase in relative importance at high pH and low ionic strengths, while low pH and high ionic strengths favored the inner-sphere complexes. The information gained from the infrared spectroscopic investigations was used as qualitative input in the formulation of the surface complexation models. New models, based on the extended constant capacitance approach, were presented for the o-phthalate/aged gamma-Al2O3 and o-phthalate/goethite systems. Copyright 1998 Academic Press.

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