Co-nonsolvency of PNiPAM at the transition between solvation mechanisms.

We investigate the co-nonsolvency of poly-N-isopropyl acrylamide (PNiPAM) in different water-alcohol mixtures and show that this phenomenon is due to two distinct solvation contributions governing the phase behavior of PNiPAM in the water-rich and alcohol-rich regime respectively. While hydrophobic hydration is the predominant contribution governing the phase behavior of PNiPAM in the water-rich regime, the mixing contributions governing the phase behavior of classical polymer solutions determine the phase behavior of PNiPAM in the alcohol-rich regime. This is evidenced by distinct scaling relations denoting the energetic state of the aqueous medium as a key parameter for the phase behavior of PNiPAM in the water-rich regime, while the volume fractions of respectively water, alcohol and PNiPAM become relevant parameters in the alcohol-rich regime. Adding alcohol to water decreases the energetics of the aqueous medium, which gradually suppresses hydrophobic hydration, while adding water to alcohol decreases the solvent quality. Consequently, PNiPAM is insoluble in the intermediate range of solvent composition, where neither hydrophobic hydration nor the mixing contributions prevail. This accounts for the co-nonsolvency phenomenon observed for PNiPAM in water-alcohol mixtures.

Hydrophobic hydration of poly-N-isopropyl acrylamide: a matter of the mean energetic state of water.

The enthalpically favoured hydration of hydrophobic entities, termed hydrophobic hydration, impacts the phase behaviour of numerous amphiphiles in water. Here, we show experimental evidence that hydrophobic hydration is strongly determined by the mean energetics of the aqueous medium. We investigate the aggregation and collapse of an amphiphilic polymer, poly-N-isopropyl acrylamide (PNiPAM), in aqueous solutions containing small amounts of alcohol and find that the thermodynamic characteristics defining the phase transitions of PNiPAM evolve relative to the solvent composition at which the excess mixing enthalpy of the water/alcohol mixtures becomes minimal. Such correlation between solvent energetics and solution thermodynamics extends to other mixtures containing neutral organic solutes that are considered as kosmotropes to induce a strengthening of the hydrogen bonded water network. This denotes the energetics of water as a key parameter controlling the phase behaviour of PNiPAM and identifies the excess mixing enthalpy of water/kosmotrope mixtures as a gauge of the kosmotropic effect on hydrophobic assemblies.

[A micro-education programme for breastfeeding women: a pilot study to investigate the educations' effect on injured and painful nipples]. / Mikroschulungsprogramm für stillende Wöchnerinnen: Pilotstudie zur Auswirkung der Schulungen auf schmerzende und wunde Mamillen.

Injured and painful nipples are frequently occurring events in nursing women during the first days after giving birth. These problems often result in a premature termination of breastfeeding despite the mother's wish to nurse. Unsystematic instructions given to women regarding correct breastfeeding increase the risk that these complications will arise. The objective of the study was to investigate the effect of a systematic micro-education programme for nursing women by means of a pilot study or a quasi-experiment. The study included 100 mother and child pairs each in the experimental group and in the control group (N = 200). The pain experienced by all women during nursing was measured using the Visual Analogue Scale (VAS) and the degree of injury to the nipples after nursing was measured with a tool specially developed for this purpose, the Nipple Wound Score (NWS). Women who received instructions by means of the micro-education programme exhibited significantly less injured nipples (on the third day: experimental group 55 % and control group 77 %, p < 0.00; on the fourth day: 56 % and 80 %, p < 0.00).No differences were observed between the study groups in regard to the occurrence of pain (on the fourth day p = 0.68). The variables of birthing method, parity, age or nationality of the women had no effect on the degree of injury of the nipples or on the intensity of pain. The results of this pilot study suggest that repeated micro-education for breastfeeding women should be implemented during the first days after giving birth.

[Developing and establishing an expanded and more comprehensive HIV/AIDS nursing practice]. / Entwicklung und Etablierung einer erweiterten und vertieften HIV/Aids-Pflegepraxis.

Developing and establishing an advanced nursing practice is an essential step toward future-oriented nursing care. An action research process was initiated to establish advanced nursing practice at the HIV clinic of the outpatient department at the University Hospital Basel with the goal to offer advanced nursing care to patients. Participatory action research allows generating knowledge about a social system while at the same time tempts to promote social change. The most important goal is to constantly analyse, improve, and evaluate nursing care for patients and family caregivers. Advanced nursing practice in HIV/AIDS is based on solid knowledge regarding the illness and current therapies. Central concepts are caring, clinical experiences, evidence based practice, and patient preferences. Through a systematic step-by-step process, the nurses at the HIV clinic are being better educated and more experienced in these concepts. An essential aspect of advanced nursing practice is the specialization of each nurse in a self selected topic within HIV/AIDS care. These nurses now offer new services such as medication management and adherence support, health maintenance and prevention, and symptom management. This ongoing process of learning while establishing advanced nursing practice in HIV/AIDS, enables the nurses to face future changes in health care in a proactive way.

[Families living with HIV and Aids--review of the literature]. / Familien, die mit HIV und Aids leben--Eine Literaturübersicht.

This article presents the current state of the art regarding the concept of families living with HIV and Aids. The literature reflects a comprehensive view including families of origin, families of choice and partnerships. It is evident that family networks of homosexual men are most systematically described in the literature; to a lesser extent families with hemophilia and i.v. drug users and even fewer studies are found regarding families with a heterosexual transmission background and especially female family caregivers. This paper also focuses on the wide range of support offered by these family systems. The acute and mostly terminal infectious disease Aids, as observed in the 80 Dies, has now become a predominantly chronic-progressive illness. Since the mid 90 Dies, the new antiretroviral therapies have further decreased morbidity and mortality, leading to less personal care, high-tech nursing requirements and household support. This development places families in a position of providing more emotional and advocatory support and companionship over a considerably longer time span. The discussion identifies strengths and weaknesses of the current literature in order to define deficits in the Anglo-American as well as in the German speaking area. From a nursing science point of view, the characteristics of HIV/Aids care must be further acknowledged, described and systematically studied, and results must be made accessible. This is important because the knowledge acquired by studying families affected by HIV and Aids is of interest for other family systems dealing with chronically ill family members. Finally, research recommendations are listed regarding family-oriented care and future study designs.