1000 resultados para advanced


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The unloading behavior was compared for three different steel grades: a dual-phase steel, a transformation-induced plasticity steel, and a twinning-induced plasticity steel. Steels that harden by phase transformation or deformation twinning exhibited a smaller component of microplastic strain during unloading and a smaller reduction in the chord modulus compared to the conventional hardening steel. As a result, unloading is closer to pure elastic unloading when the TRIP effect or TWIP effect is active.

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The aim of the work is development of industry guidance concerning production of ultrafine-grained (UFG) High Strength Low Alloy (HSLA) steels using strain-induced dynamic phase transformations during advanced thermomechanical processing. In the first part of the work, the effect of processing parameters on the grain refinement was studied. Based on the obtained results, a multiscale computer model was developed in the second part of the work that was subsequently used to predict the mechanical response of studied structures. As an overall outcome, a process window was established for the production of UFG steels that can be adopted in existing hot rolling mills. © 2014 Elsevier B.V.

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The microstructure of transformation induced plasticity (TRIP) and dual phase (DP) multiphase steels after stamping of an industrial component at different strain levels was investigated using transmission electron microscopy. The TRIP steel microstructure showed a more complex dislocation substructure of ferrite at different strain levels than DP steel. The deformation microstructure of the stamped parts was compared to the deformation microstructure in these complex steels for different "equivalent" tensile strains. It was found that the microstructures are similar only at high levels of strain (>10 pct) for both steels. © 2014 The Minerals, Metals & Materials Society and ASM International.

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Dual phase (DP) steels were modeled using 2D and 3D representative volume elements (RVE). Both the 2D and 3D models were generated using the Monte-Carlo-Potts method to represent the realistic microstructural details. In the 2D model, a balance between computational efficiency and required accuracy in truly representing heterogeneous microstructure was achieved. In the 3D model, a stochastic template was used to generate a model with high spatial fidelity. The 2D model proved to be efficient for characterization of the mechanical properties of a DP steel where the effect of phase distribution, morphology and strain partitioning was studied. In contrast, the current 3D modeling technique was inefficient and impractical due to significant time cost. It is shown that the newly proposed 2D model generation technique is versatile and sufficiently accurate to capture mechanical properties of steels with heterogeneous microstructure.

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PURPOSE: Thousands of children are living with advanced cancer; yet patient-reported outcomes (PROs) have rarely been used to describe their experiences. We aimed to describe symptom distress in 104 children age 2 years or older with advanced cancer enrolled onto the Pediatric Quality of Life and Evaluation of Symptoms Technology (PediQUEST) Study (multisite clinical trial evaluating an electronic PRO system).

METHODS: Symptom data were collected using age- and respondent-adapted versions of the PediQUEST Memorial Symptom Assessment Scale (PQ-MSAS) at most once per week. Clinical and treatment data were obtained from medical records. Individual symptom scores were dichotomized into high/low distress. Determinants of PQ-MSAS scores were explored using linear mixed-effects models.

RESULTS: During 9 months of follow-up, PQ-MSAS was administered 920 times: 459 times in teens (99% self-report), 249 times in children ages 7 to 12 years (96% child/parent report), and 212 times in those ages 2 to 6 years (parent reports). Common symptoms included pain (48%), fatigue (46%), drowsiness (39%), and irritability (37%); most scores indicated high distress. Among the 73 PQ-MSAS surveys administered in the last 12 weeks of life, pain was highly prevalent (62%; 58% with high distress). Being female, having a brain tumor, experiencing recent disease progression, and receiving moderate- or high-intensity cancer-directed therapy in the prior 10 days were associated with worse PQ-MSAS scores. In the final 12 weeks of life, receiving mild cancer-directed therapy was associated with improved psychological PQ-MSAS scores.

CONCLUSION: Children with advanced cancer experience high symptom distress. Strategies to promote intensive symptom management are indicated, especially with disease progression or administration of intensive treatments.

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BACKGROUND: Building capacity in a changing health care system is a challenge for advanced nursing education programs. Master-level nursing education is increasingly becoming the required education level for specialist nurses, and additional studies are needed to learn more about students' experiences and learning transitions while undertaking such education. This study aimed to explore nursing students' experience of their learning transitions while undertaking advanced nursing education and to describe how they translated the new knowledge and competence they gained into clinical practice. METHODS: We used a qualitative research design with narrative self-reported reflections. 34 nurses (95 % women) from both urban and rural areas working with children, with adults in outpatient and inpatient endocrinology clinics in hospitals or with adults, including older people, attending primary health care services participated in the study. We collected data at two time points 15 months apart. Time one was the first week of the advanced nursing education, and time two was the completion of the education program. We used Malterud's modification of Giorgi's phenomenological analysis, otherwise known as systematic text condensation, to analyze the data. RESULTS: Two core themes captured the participants' experiences. The first theme was "assessing the situation of people with diabetes from a different perspective", with the subthemes "an expanded perspective of practice and higher level of reflection", "applying critical thinking in practice" and "changing patient-nurse relationships in diabetes care". The second core theme was "a change in participants' perception of their professional position", with the subthemes "a greater knowledge base enhancing professional confidence" and "a more equal position within the professional team". CONCLUSIONS: The study provides in-depth information about transition into advanced nursing education and can inform curriculum developers, nurse educators, policy-makers and nursing managers about how nursing education broadened participants' perspectives of nursing and enhanced their confidence and professional position.

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Objective : Informal caregivers of people with advanced cancer experience many negative impacts as a result of their role. There is a lack of suitable measures specifically designed to assess their experience. This study aimed to develop a new measure to assess self-efficacy in caregivers of people with advanced cancer.

Methods : The development and testing of the new measure consisted of four separate, sequential phases: generation of issues, development of issues into items, pilot testing and field testing. In the generation of issues, 17 caregivers were interviewed to generate data. These data were analysed to generate codes, which were then systematically developed into items to construct the instrument. The instrument was pilot tested with 14 health professionals and five caregivers. It was then administered to a large sample for field testing to establish the psychometric properties, with established measures including the Brief Cope and the Family Appraisals for Caregiving Questionnaire for Palliative Care.

Results : Ninety-four caregivers completed the questionnaire booklet to establish the factor structure, reliability and validity. The factor analysis resulted in a 21-item, four-factor instrument, with the subscales being termed Resilience, Self-Maintenance, Emotional Connectivity and Instrumental Caregiving. The test-retest reliability and internal consistency were both excellent, ranging from 0.73 to 0.85 and 0.81 to 0.94, respectively. Six convergent and divergent hypotheses were made, and five were supported.

Conclusions : This study has developed a new instrument to assess self-efficacy in caregivers of people with advanced cancer. The result is a four-factor, 21-item instrument with demonstrated reliability and validity.

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Informal carers are people who provide care without a specific professional role. They provide diverse caregiving supports including disease-related problems, side effects of treatment and psychosocial impacts. This paper reports on a comprehensive review of caregiving literature, focusing specifically on cancer caregivers. The paper presents five observations drawn from the literature in order to make recommendations about how caregivers of people with advanced cancer can best be supported. The observations are: 1) caregivers are a heterogeneous group; 2) they have unique needs that differ to the patient; 3) their role includes more than attending to physical caregiving tasks; 4) they may feel unable to take a break from the role and 5) they need their own support which may be beneficial to their capacity to continue in the caregiving role. Recommendations for how health professionals can assist in supporting caregivers in their role are discussed.

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Purpose : Family caregivers of people with advanced cancer can provide extensive support to the patient. However, the role is not well defined and their experiences are poorly understood. This study aimed to explore how caregivers view their role and the impact of their caregiving.

Methods : A symbolic interactionist framework guided the in-depth individual interviews and grounded theory methodology was used to analyse the data. A total of 17 interviews were conducted: 13 with active caregivers and 4 with bereaved caregivers.

Results : Three dominant codes are presented. Caregivers lacked role recognition, as they struggled to recognise their role existed, even though they took on extensive and challenging tasks. Caregivers reported substantial loss or changes to their self-identity: with some caregivers reporting not being able to stop thinking about caregiving and others having difficulty answering questions about themselves. Caregivers also demonstrated difficulty in taking a break: active caregivers did not consider taking a break, whereas bereaved caregivers retrospectively admitted needing a break but reported an inability to take one.

Conclusions : Caregiving is complex and extensive. People who care for those with advanced cancer are in need of intervention to provide support and assistance to them in their role. However, this needs to be structured with consideration for how caregivers view their role.

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Objective: The Needs Assessment for Advanced Cancer Patients (NA-ACP) is a 132-item self-report questionnaire designed to assess the seven needs domains of patients with advanced, incurable cancer. This study aimed to evaluate the short derivative form of that questionnaire with advanced lung cancer patients.

Methods: Item factor loadings, item test–retest data and response distributions were used to retain or reject items from the original NA-ACP scale. This resulted in 38 items being maintained, preserving the original subscales. The response scale was simplified following feedback from patients. 108 people with advanced lung cancer completed the shortened NA-ALCP along with measures of psychological distress (HADS, DT) and quality of life (EORTC QLQ-C30). A-priori predictions were made for divergent and convergent validity.

Results: Internal consistency coefficients were satisfactory for six of seven subscales, range 0.71–0.95. Correlations between NA-ALCP and HADS, DT and EORTC-QLQ-C30 provided support for 11 of the 22 divergent (r = 0.13–0.27) and convergent predictions (r = 0.45–0.71).

Conclusions: Subscales of the NA-ALCP demonstrated internal reliability consistent with the original scale. Results provided supporting evidence for divergent and convergent validity. This study indicates that the NA-ALCP is psychometrically robust, easily understood and one-quarter the length of the original version

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 The increasing complexities of prostate cancer disease progression necessitates more stable and less toxic therapeutic strategies. The current study demonstrated for the first time, the survivin targeted anti-cancer therapeutic activity of the bio-molecular drugs such as SurR9-C84A and bovine lactoferrin in inducing prostate cancer specific apoptosis. Moreover, improved therapeutic efficacy was conferred to these bio-molecules either by their encapsulation in stem cell targeted bio-compatible nanoparticles, or by the synthesis of protein-cytotoxic drug conjugates. This study also highlighted the role played by miRNAs in the regulation of iron metabolism and apoptosis, mediated by the selective activation of p53 and PTEN pathways.

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Advanced high-strength steels (AHSS) are a class of steel used primarily in sheet form for automotive structures. The microstructures of the types of steel in this classification were initially multiphase, with ferrite as the dominant phase; however, grades introduced more recently have been fully martensitic or based on austenite. This chapter initially introduces the requirements of an automotive body structure, then the different classes of AHSS that have been used in the automotive industry and their typical characteristic tensile properties. The specific properties that are required for steel used in automotive body structures are subsequently described, including formability and crash behaviour. Finally, some of the current and future trends in the development of new steel grades are discussed.

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Recent obesity trends in children and adolescents suggest a plateau. However, it is unclear whether such trends have been experienced across socioeconomic groups. We analysed whether recent trends in child and adolescent overweight and obesity differ by socioeconomic position (SEP) across economically advanced countries. Eligible studies reported overweight and obesity prevalence in children and/or adolescents (2-18 years), for at least two time points since 1990, stratified by SEP. Socioeconomic differences in trends in child and adolescent overweight and obesity over time were analysed. Differences in trends between SEP groups were observed across a majority of studies. Over half the studies indicated increasing prevalence among low SEP children and adolescents compared to a third of studies among children and adolescents with a high SEP. Around half the studies indicated widening socioeconomic inequalities in overweight and obesity. Since 2000 a majority of studies demonstrated no change or a decrease in prevalence among both high and low SEP groups. However around 40% of studies indicated widening of socioeconomic inequalities post-2000. While our study provides grounds for optimism, socioeconomic inequalities in overweight and obesity continue to widen. These findings highlight the need for greater consideration of different population groups when implementing obesity interventions. © 2015 World Obesity.