| 761. |
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| 762. |
- Daşu, Alexandru, et al.
(författare)
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The relationship between vascular oxygen distribution and tissue oxygenation
- 2009
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Ingår i: Advances in Experimental Medicine and Biology. - Boston, MA : Springer US. - 0065-2598 .- 2214-8019. ; 645, s. 255-260
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Tidskriftsartikel (refereegranskat)abstract
- Tumour oxygenation could be investigated through several methods that use various measuring principles and can therefore highlight its different aspects. The results have to be subsequently correlated, but this might not be straightforward due to intrinsic limitations of the measurement methods. This study describes an analysis of the relationship between vascular and tissue oxygenations that may help the interpretation of results. Simulations have been performed with a mathematical model that calculates the tissue oxygenation for complex vascular arrangements by taking into consideration the oxygen diffusion into the tissue and its consumption at the cells. The results showed that while vascular and tissue oxygenations are deterministically related, the relationship between them is not unequivocal and this could lead to uncertainties when attempting to correlate them. However, theoretical simulation could bridge the gap between the results obtained with various methods.
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| 763. |
- Daşu, Alexandru, et al.
(författare)
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Theoretical simulation of tumour oxygenation--practical applications
- 2006
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Ingår i: Advances in Experimental Medicine and Biology. - : Springer US. - 0065-2598 .- 2214-8019. ; 578, s. 357-362
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Tidskriftsartikel (refereegranskat)abstract
- Theoretical simulation of tissue oxygenation is a robust method that can be used to quantify the tissue oxygenation for a variety of applications. However, it is necessary that the relevant input parameters are used for the model describing the tumour microenvironment. The results of the simulations presented in this article suggest that the accuracy of the simulations depends very much on the method of calculation of the effects of the temporal change of the hypoxic pattern due to the opening and the closure of blood vessels. Thus, the use of average oxygenations might lead to dangerous overestimations of the treatment response. This indicates that care should be taken when incorporating hypoxia information into the biological modelling of tumour response.
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| 764. |
- Dasu, Alexandru, et al.
(författare)
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What is the Clinically Relevant Relative Biologic Effectiveness? A Warning for Fractionated Treatments With High Linear Energy Transfer Radiation
- 2008
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Ingår i: International Journal of Radiation Oncology, Biology, Physics. - : Elsevier. - 0360-3016 .- 1879-355X. ; 70:3, s. 867-874
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To study the clinically relevant relative biologic effectiveness (RBE) of fractionated treatments with high linear energy transfer (LET) radiation and to identify the important factors that might influence the transfer of tolerance and curative levels from low LET radiation. These are important questions in the light of the growing interest for the therapeutic use of radiation with higher LET than electrons or photons.METHODS AND MATERIALS: The RBE of various fractionated schedules was analyzed with theoretical models for radiation effect, and the resulting predictions were compared with the published clinical and experimental data regarding fractionated irradiation with high LET radiation.RESULTS: The clinically relevant RBE increased for greater doses per fraction, in contrast to the predictions from single-dose experiments. Furthermore, the RBE for late-reacting tissues appeared to modify more quickly than that for early-reacting tissues. These aspects have quite important clinical implications, because the increased biologic effectiveness reported for this type of radiation would otherwise support the use of hypofractionation. Thus, the differential between acute and late-reacting tissues could put the late-reacting normal tissues at more risk from high LET irradiation; however, at the same time, it could increase the therapeutic window for slow-growing tumors.CONCLUSIONS: The modification of the RBE with the dose per fraction must be carefully taken into consideration when devising fractionated treatments with high LET radiation. Neglecting to do so might result in an avalanche of complications that could obscure the potential advantages of the therapeutic use of this type of radiation.
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| 765. |
- de Alwis, Pahansen, 1980-, et al.
(författare)
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Exposure aboard high-performance Marine craft increases musculoskeletal pain and lowers contemporary work capacity of the occupants
- 2021
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Ingår i: Journal of Engineering for the Maritime Environment (Part M). - : SAGE Publications. - 1475-0902 .- 2041-3084. ; 235:3, s. 750-762
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Tidskriftsartikel (refereegranskat)abstract
- High-Performance Marine Craft (HPMC) occupants are currently being investigated for various psychophysical impairments degrading work performance postulating that these deteriorations are related to their occupational exposures. However, scientific evidence for this is lacking and the association of exposure conditions aboard HPMC with adverse health and performance effects is unknown. Therefore, the study estimates the prevalence of musculoskeletal pain (MSP) among HPMC occupants and the association of their work exposure with MSP and performance degradation. It also presents a criterion for evaluating the self-reported exposure severity aboard three different types of mono-hull HPMC; displacement, semi-displacement and planing, on a par with the available standard criteria for objectively measurable exposures. Furthermore, another criterion is proposed to assess the performance-degradation of HPMC occupants based on self-reported fatigue symptoms and MSP. Swedish Coast Guard HPMC occupants were surveyed for MSP, fatigue symptoms as well as for work-related and individual risk indicators using a validated web-based questionnaire. Prevalence of MSP and performance-degradation during the past 12 months were assessed and presented as a percentage of the sample. Associations of exposure conditions aboard HPMC with MSP and performance-capacity were systematically evaluated using multiple logistic regression models and expressed as odds ratio (OR). Prevalence of MSP was 72% among which lower back pain was the most prevalent (46%) followed by neck pain (29%) and shoulder pain (23%) while 29% with degraded performance. Exposure to severe conditions aboard semi-displacement craft was associated with lower back (OR = 2.3) and shoulder (OR = 2.6) pain while severe conditions aboard planing craft with neck pain (OR = 2.3) and performance-degradation (OR = 2.6). MSP is common among Swedish coast guards. Severe exposure conditions aboard HPMC are significantly associated with both MSP and performance-degradation. The spine and shoulders are the most susceptible to work-related MSP among HPMC occupants which should be targeted in work-related preventive and corrective measures.
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| 766. |
- du Prel, Jean-Baptist, et al.
(författare)
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Work overcommitment : Is it a trait or a state?
- 2018
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 0340-0131 .- 1432-1246. ; 91:1, s. 1-11
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Tidskriftsartikel (refereegranskat)abstract
- Effort-reward imbalance (ERI) is a well-tested work-related stress model with three components, the two extrinsic components efforts and rewards and the one intrinsic component overcommitment. While an imbalance between efforts and rewards leads to strain reactions, work-related overcommitment (OC) has been described as a personal characteristic with a set of attitudes, behaviours, and emotions reflecting excessive striving combined with a strong desire for approval. However, the question whether OC is a personality trait or a response pattern sensitive to changes in the work context (state) is still open. 2940 Swedish industrial employees were included in this longitudinal analysis of the WOLF-Norrland data over 5 years. A change of OC index or its subscales were regressed against a change of freedom of choice at work, extra work, and ERI adjusted for age, sex, and education. While OC was insensitive to changes in freedom of choice at work and extra work, it was clearly associated with changes of work-related stress over time. Three of four OC subscales exhibited statistically significant associations with ERI. For the first time, we studied fundamental characteristics of OC as an independent personality variable (trait) or an outcome variable subject to changes in the work environment (state). The association between external ERI and OC over time supports our hypothesis of OC being a state. Further investigations are needed to establish OC as a trait or a state.
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| 767. |
- Eib, Constanze, et al.
(författare)
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Don't Let It Get to You! A Moderated Mediated Approach to the (In)Justice-Health Relationship
- 2015
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Ingår i: Journal of Occupational Health Psychology. - : American Psychological Association (APA). - 1076-8998 .- 1939-1307. ; 20:4, s. 434-445
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigates the consequences of overall justice perceptions on employees' mental health and work-family conflict. While many studies have found that perceiving injustice at work is harmful, little is known about the underlying processes. Based on the allostatic load model, it is hypothesized that mental preoccupation with work, defined as a cognitive state, is a mediator linking overall justice perceptions to employee health. Moreover, we argue that locus of control is a moderator for the mediated relationship. We tested our hypotheses with panel data consisting of 412 Swedish office workers. Results support that mental preoccupation with work mediates the relationship between overall justice and mental health, and overall justice and work-family conflict. Results also reveal that mental preoccupation with work plays a greater mediating role for individuals with an external locus of control. Implications and suggestions for future studies on the emerging relationship between organizational justice and health are discussed.
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| 768. |
- Eklund, Caroline, 1983-, et al.
(författare)
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The Meaning of Sedentary Behavior as Experienced by People in the Transition From Working Life to Retirement : An Empirical Phenomenological Study
- 2021
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Ingår i: Physical Therapy. - : Oxford University Press (OUP). - 0031-9023 .- 1538-6724. ; 101:8
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveSedentary behavior (SB) is defined as a mean of >6 hours of daytime sitting or lying down. SB has been shown to increase with older age and is a risk factor for disease. During the transition from working life to retirement, changes in daily life activities occur, risking increased SB. The aim of the present study was to gain a deeper understanding of SB in relation to the transition from working life to retirement as experienced by persons in retirement.MethodsThe study was grounded in a phenomenological life-world perspective. Fourteen semi-structured interviews were conducted with participants aged 64–75. Data were analyzed using the empirical phenomenological psychological method.ResultsThe participants described that voluntary sedentary time was positively related to general health and well-being, while involuntary sedentary time was negatively related to health. Increased sedentary time was described as natural when aging. Retirement was expressed as a time for rest after hard work and the ability to choose a slower pace in life. Internal and external demands and daily routines interrupted SB, whereas loneliness was perceived to increase SB. Participants strived to find a balance between physical activity and sedentary time. The variations in the participants’ descriptions formed three typologies: in light of meaningful sedentary behavior, in the shadow of involuntary sedentary behavior, and a dual process – postponing sedentary behavior with physical activity.ConclusionsIncreased SB was perceived as natural when aging, but something that may be postponed by conscious choices. SB was perceived as associated with health, rest and recovery but also with the risk of deteriorating health.ImpactThis knowledge of the experienced meaning of SB could guide the design of health promotion interventions and may be helpful in targeting those in need of support and individualizing interventions to decrease SB in retirement.Lay SummaryThis study reveals how persons in retirement describe sedentary behavior as something healthy but also as unhealthy and that sedentary behavior is natural in aging and can be postponed by physical activity.
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| 769. |
- Ekstedt, Mirjam, et al.
(författare)
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Lived experiences of the time preceding burnout
- 2005
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Ingår i: Journal of Advanced Nursing. - : Wiley. - 0309-2402 .- 1365-2648. ; 49:1, s. 59-67
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper reports a study to illuminate the complex interaction between person and their life world during the burnout development period.BACKGROUND: Burnout is a construct describing the psychological state resulting from ineffective strategies for coping with enduring stress in both client and non-client work. Role conflict and role ambiguity, or long-term stress and frustration caused by strain in daily life, promote or exacerbate burnout, indicating that the person's entire life world is involved. There is still a lack of description of lived experiences of the time preceding manifest burnout.METHOD: Data were collected from interviews with eight people suffering from burnout and analysed using a phenomenological method.FINDINGS: The essential meaning of the phenomenon of burnout is understood as being trapped with stimulating challenges as a self-nourishing drive on one side and with responsibilities and demands on the other. This essence can be illuminated by its eight constituents: inner incentive, feeling responsible, threatened self-image, cutting off, bodily manifestations, psychological manifestations, fatigue and reaching the bottom line.CONCLUSIONS: The lived experiences of the time preceding manifest burnout are an ambiguous struggle. Cutting off is understood as a mean to shelter the threatened self-image in a state of vulnerability and weakened strength. Accordingly, a better understanding of how to reach behind the defence of 'cutting off' and thus help to open up for consolation and self-acceptance is an essential skill for nurses, health care professionals and others encountering the burnout sufferers. Furthermore this study illuminates early signs of burnout and an important issue is how to strengthen the individuals' ability to shelter their need for recovery and restitution.
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| 770. |
- Ekstedt, Mirjam, Professor, et al.
(författare)
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Nursing students' perception of the clinical learning environment and supervision in relation to two different supervision models : a comparative cross-sectional study
- 2019
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Ingår i: BMC Nursing. - : BioMed Central. - 1472-6955 .- 1472-6955. ; 18:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Knowledge concerning nursing students' experiences of the clinical learning environment and how supervision is carried out is largely lacking. This study compares nursing students' perceptions of the clinical learning environment and supervision in two different supervision models: peer learning in student-dedicated units, with students working together in pairs and supervised by a "preceptor of the day" (model A), and traditional supervision, in which each student is assigned to a personal preceptor (model B). Methods: The study was performed within the nursing programme at a university college in Sweden during students' clinical placements (semesters 3 and 4) in medical and surgical departments at three different hospitals. Data was collected using the Clinical Learning Environment, Supervision and Nurse Teacher evaluation scale, CLES+T, an instrument tested for reliability and validity, and a second instrument developed for this study to obtain deeper information regarding how students experienced the organisation and content of the supervision. Independent t-tests were used for continuous variables, Mann-Whitney U-tests for ordinal variables, and the chi-square or Fischer's exact tests for categorical variables. Results: Overall, the students had positive experiences of the clinical learning environment and supervision in both supervision models. Students supervised in model A had more positive experiences of the cooperation and relationship between student, preceptor, and nurse teacher, and more often than students in model B felt that the ward had an explicit model for supervising students. Students in model A were more positive to having more than one preceptor and felt that this contributed to the assessment of their learning outcomes. Conclusions: A good learning environment for students in clinical placements is dependent on an explicit structure for receiving students, a pedagogical atmosphere where staff take an interest in supervision of students and are easy to approach, and engagement among and collaboration between preceptors and nurse teachers. This study also indicates that supervision based on peer learning in student-dedicated rooms with many preceptors can be more satisfying for students than a model where each student is assigned to a single preceptor.
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