128 research outputs found
Organs from animals for man
In the following review some of the problems of xenotransplantation shall be discussed, based on the few experimental data available so far and on reports in the literature describing investigations which may be of importance for xenotransplantation. The impact of gravity on the upright posture of man versus almost all other mammals, the dysfunction between enzymes and hormones in different species and the lack of interactions between interleukins, cytokines and vasoactive substances will be taken into consideration. The question must be asked whether different levels of carrier molecules or serum proteins play a role in the physiological network. Even though the development of transgenic animals or other imaginative manipulations may lead to the acceptance of any type of xenografted organ, it has to be established for how long the products of the xenografts are able to act in the multifactorial orchestra. We are far from understanding xenogeneic molecular mechanisms involved in toxicity, necrosis and apoptosis or even reperfusion injury and ischemia in addition to the immediate mechanisms of the hyperacute xenogeneic rejection. Here, cell adhesion, blood clotting and vasomotion collide and bring micro-and macrocirculation to a standstill. All types of xenogeneic immunological mechanisms studied so far were found to have a more serious impact than those seen in allogeneic transplantation. In addition we are now only beginning to understand that so-called immunological parameters in allogeneic mechanisms act also in a true physiological manner in the xenogeneic situation. These molecular mechanisms occur behind the curtain of hyperacute, accelerated, acute or chronic xenograft rejection of which only some folds have been lifted to allow glimpses of part of the total scene. Other obstacles are likely to arise when long-term survival is achieved. These obstacles include retroviral infections, transfer of prions and severe side effects of the massive immunosuppression which will be needed. Moral, ethical and religious concerns are under debate and the species-specific production of proteins of the foreign donor species developed for clinical use suddenly appears to be a greater problem than anticipated
Role of Cognitive Distortions and Dysfunctional Attitudes in Nurses Experiencing Burnout
As a means of gathering more data to support the utility of cognitive-behavioral therapy with individuals experiencing burnout, this current study is designed to identify whether or not distorted thinking and dysfunctional attitudes are present in registered nurses who are experiencing burnout and whether or not they differ in registered nurses not experiencing burnout. A mail survey to a random sample of certified critical care registered nurses working in hospital settings was conducted. Participants provided basic demographic data and completed the Maslach Burnout Inventory, the Inventory of Cognitive Distortions, and the Dysfunctional Attitudes Scale. In addition, participants completed measures of intent to leave or to stay, job satisfaction, and the work environment. A descriptive correlation design was employed. Results supported the relationship between burnout, cognitive distortions, and dysfunctional attitudes. Moreover, results demonstrate that magnification is the distortion most strongly linked with burnout. Job satisfaction, intent to leave or to stay, and various measures of the workplace environment by and large were shown to be significantly correlated with burnout, cognitive distortions, and dysfunctional attitudes. Finally, results support the validity and reliability of the Inventory of Cognitive Distortions
Fracture characteristics of PEEK at various stress triaxialities
Polyether-ether-ketone (PEEK) is an alternative to metal alloys in orthopaedic applications. It gives significant advantages including excellent mechanical properties and non-toxicity. In this work, a set of specimens with different notched radii were selected to examine the effect of triaxial state of stress on the fracture behavior of PEEK. Fractographic analysis via scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) further elucidated the fracture micromechanisms. Distinct fracture patterns were identified under different stress triaxialities. In addition, the microstructural inclusion properties in PEEK specimen such as inclusion size and chemical composition were analysed and determined. Finite element simulations were carried out to evaluate the correlation of observed fracture characteristics with different stress triaxialities
Exploring the experiences of being an ethnic minority student within undergraduate nurse education: A qualitative study
© 2019 The Author(s). Background: Students studying in a country where another language is spoken face multiple challenges including their ability to fully integrate with peers and academic pressures in trying to obtain an undergraduate nursing degree. The aim of the study was to explore the lived experiences of students, from varying cultural and ethnic backgrounds, undertaking an undergraduate nursing degree. Methods: The study adopted a qualitative design and eight individual semi-structured interviews were conducted. The interviews were analysed using manifest content analysis according to Graneheim and Lundman. Results: Students reported feelings of isolation and the lack of opportunities to integrate with native students within academia and practice. The need for personal support was a crucial factor that was independent of gender and students reported challenges related to both language and culture during the programme. Conclusions: Suggestions arising from this study includes appropriate support systems within academia and practice. It is imperative that universities and practice settings promote and integrate cultural awareness within academia and practice in meeting the needs of students and providing culturally appropriate nursing care, thereby providing opportunities for all students to become competent and professional practitioners
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