287 resultados para medical implants
Resumo:
Pancreatic adenocarcinoma is the fourth leading cause of cancer death and has an extremely poor prognosis: The 5-year survival probability is less than 5% for all stages. The only chance for cure or longer survival is surgical resection; however, only 10% to 20% of patients have resectable disease. Although surgical techniques have improved, most who undergo complete resection experience a recurrence. Adjuvant systemic therapy reduces the recurrence rate and improves outcomes. There is a potential role for radiation therapy as part of treatment for locally advanced disease, although its use in both the adjuvant and neoadjuvant settings remains controversial. Palliative systemic treatment is the only option for patients with metastatic disease. To date, however, only the gemcitabine plus erlotinib combination, and recently the FOLFIRINOX regimen, have been associated with relatively small but statistically significant improvements in OS when compared directly with gemcitabine alone. Although several meta-analyses have suggested a benefit associated with combination chemotherapy, whether this benefit is clinically meaningful remains unclear, particularly in light of the enhanced toxicity associated with combination regimens. There is growing evidence that the exceptionally poor prognosis in PC is caused by the tumor's characteristic abundant desmoplastic stroma that plays a critical role in tumor cell growth, invasion, metastasis, and chemoresistance. Carefully designed clinical trials that include translational analysis will provide a better understanding of the tumor biology and its relation to the host stromal cells. Future directions will involve testing of new targeted agents, understanding the pharmacodynamics of our current targeted agents, searching for predictive and prognostic biomarkers, and exploring the efficacy of different combinations strategies.
Resumo:
This study addresses cultural differences regarding views on the place for spirituality within healthcare training and delivery. A questionnaire was devised using a 5-point ordinal scale, with additional free text comments assessed by thematic analysis, to compare the views of Ugandan healthcare staff and students with those of (1) visiting international colleagues at the same hospital; (2) medical faculty and students in United Kingdom. Ugandan healthcare personnel were more favourably disposed towards addressing spiritual issues, their incorporation within compulsory healthcare training, and were more willing to contribute themselves to delivery than their European counterparts. Those from a nursing background also attached a greater importance to spiritual health and provision of spiritual care than their medical colleagues. Although those from a medical background recognised that a patient’s religiosity and spirituality can affect their response to their diagnosis and prognosis, they were more reticent to become directly involved in provision of such care, preferring to delegate this to others with greater expertise. Thus, differences in background, culture and healthcare organisation are important, and indicate that the wide range of views expressed in the current literature, the majority of which has originated in North America, are not necessarily transferable between locations; assessment of these issues locally may be the best way to plan such training and incorporation of spiritual care into clinical practice.
Resumo:
This review paper discusses the use of Tellus and Tellus Border soil and stream geochemistry data to investigate the relationship between medical data and naturally occurring background levels of potentially toxic elements (PTEs) such as heavy metals in soils and water. The research hypothesis is that long-term low level oral exposure of PTEs via soil and water may result in cumulative exposures that may act as risk factors for progressive diseases including cancer and chronic kidney disease. A number of public policy implications for regional human health risk assessments, public health policy and education are also explored alongside the argument for better integration of multiple data sets to enhance ongoing medical and social research. This work presents a partnership between the School of Geography, Archaeology and Palaeoecology, Northern Ireland Cancer Registry, Queen’s University Belfast, and the nephrology (kidney medicine) research group.
Resumo:
A wearable silver nano particle inkjet printed antenna suitable for wireless biomedical sensing is presented. The performance is evaluated on a synthetic variable layered phantom test-bed, representative of human tissue for operation in the 868/915 MHz, and 2400 MHz industrial, scientific and medical frequency bands. Antenna radiation efficiency measurements on the phantom were compared with antennas prototyped with copper. Total radiation efficiencies up to ???6.5 dB are reported, with less than 0.5 dB difference in performance between copper and silver nano particle variants, showing promising application for low-cost disposable wireless sensing.
Resumo:
OBJECTIVES: The Shape of Training report recommended that full registration is aligned with medical school graduation. As part of a General Medical Council-funded study about the preparedness for practice of UK medical graduates, we explored UK stakeholders' views about this proposal using qualitative interviews (30 group and 87 individual interviews) and Framework Analysis.
SETTING: Four UK study sites, one in each country.Save
PARTICIPANTS: 185 individuals from eight stakeholder groups: (1) foundation year 1 (F1) doctors (n=34); (2) fully registered trainee doctors (n=33); (3) clinical educators (n=32); (4) undergraduate/postgraduate Deans, and Foundation Programme Directors (n=30); (5) other healthcare professionals (n=13); (6) employers (n=7); (7) policy and government (n=11); (8) patient and public representatives (n=25).
RESULTS: We identified four main themes: (1) The F1 year as a safety net: patients were protected by close trainee supervision and 'sign off' to prevent errors; trainees were provided with a safe environment for learning on the job; (2) Implications for undergraduate medical education: if the proposal was accepted, a 'radical review' of undergraduate curricula would be needed; undergraduate education might need to be longer; (3) Implications for F1 work practice: steps to protect healthcare team integration and ensure that F1 doctors stay within competency limits would be required; (4) Financial, structural and political implications: there would be cost implications for trainees; clarification of responsibilities between undergraduate and postgraduate medical education would be needed. Typically, each theme comprised arguments for and against the proposal.
CONCLUSIONS: A policy change to align the timing of full registration with graduation would require considerable planning and preliminary work. These findings will inform policymakers' decision-making. Regardless of the decision, medical students should take on greater responsibility for patient care as undergraduates, assessment methods in clinical practice and professionalism domains need development, and good practice in postgraduate supervision and support must be shared.
Resumo:
Background: Peer tutoring has been described as “people from similar social groupings who are not professional teachers helping each other to learn and learning themselves by teaching”. Peer tutoring is well accepted as a source of support in many medical curricula, where participation and learning involve a process of socialisation.
Peer tutoring can ease the transition of the junior students from the university class environment to the hospital workplace. In this paper, we apply the Experienced Based Learning (ExBL) model to explore medical students’ perceptions of their experience of taking part in a newly established peer tutoring program at a hospital based
clinical school.
Methods: In 2014, all students at Sydney Medical School – Central, located at Royal Prince Alfred Hospital were invited to voluntarily participate in the peer tutoring program. Year 3 students (n = 46) were invited to act as tutors for Year 1 students (n = 50), and Year 4 students (n = 60) were invited to act as tutors for Year 2 students (n = 51). Similarly, the ‘tutees’ were invited to take part on a voluntary basis. Students were invited to attend focus groups, which were held at the end of the program. Framework analysis was used to code and categorise data into themes.
Results: In total, 108/207 (52 %) students participated in the program. A total of 42/106 (40 %) of Year 3 and 4 students took part as tutors; and of 66/101 (65 %) of Year 1 and 2 students took part as tutees. Five focus groups were held, with 50/108 (46 %) of students voluntarily participating. Senior students (tutors) valued the opportunity to practice and improve their medical knowledge and teaching skills. Junior students (tutees) valued the opportunity for additional practice and patient interaction, within a relaxed, small group learning environment.
Conclusion: Students perceived the peer tutoring program as affording opportunities not otherwise available within the curriculum. The peer teaching program provided a framework within the medical curriculum for senior students to practice and improve their medical knowledge and teaching skills. Concurrently, junior students were provided with a valuable learning experience that they reported as being qualitatively different to traditional teaching by faculty.
Resumo:
Laser transmission joining (LTJ) is growing in importance, and has the potential to become a niche technique for the fabrication of hybrid plastic-metal joints for medical device applications. The possibility of directly joining plastics to metals by LTJ has been demonstrated by a number of recent studies. However, a reliable and quantitative method for defining the contact area between the plastic and metal, facilitating calculation of the mechanical shear stress of the hybrid joints, is still lacking. A new method, based on image analysis using ImageJ, is proposed here to quantify the contact area at the joint interface. The effect of discolouration on the mechanical performance of the hybrid joints is also reported for the first time. Biocompatible polyethylene terephthalate (PET) and commercially pure titanium (Ti) were selected as materials for laser joining using a 200 W CW fibre laser system. The effect of laser power, scanning speed and stand-off distance between the nozzle tip and top surface of the plastic were studied and analysed by Taguchi L9 orthogonal array and ANOVA respectively. The surface morphology, structure and elemental composition on the PET and Ti surfaces after shearing/peeling apart were characterized by SEM, EDX, XRD and XPS.
Resumo:
Currently, micro-joining of plastic parts to metal parts in medical devices is achieved by using medical adhesives, For example, pacemakers, defibrillators and neurological stimulators are designed using silicone adhesive to seal the joint between the polyurethane connector module and the titanium can [1]. Nevertheless, the use of adhesive is problematic because it requires a long time to cure and has high tendency to produce leachable products which might be harmful to the human body. An alternative for directly joining plastics to metal without adhesive is therefore required. Laser transmission joining (LTJ) is growing in importance, and has the potential to gain the niche in micro-fabrication of plastics-metal hybrid joints for medical device applications. The possibility of directly joining plastics to metal by LTJ technique have been demonstrated by a number of studies in recent literature [2]. The widely-accepted understanding of LTJ between plastics and metal is that generation and rapid expansion of micro-bubbles at the plastics-metal interface exert high local pressure to press the melted plastics towards the metal surface features during the laser processing [2]. This subsequently creates the plastics-metal hybrid joint by the mechanisms of mechanical interlocking as well as chemical and physical bonds between the plastics and metal surfaces. Although the micro-bubbles can help promote the mechanical interlocking effect to increase the joint strength, the creation of bubble is a random and complex process depending on the complicated interactions between the laser intensity, thermal degradation properties of plastics, surface temperature and topographical features of metal. In an ideal situation, it is desirable to create the hybrid plastics-metal joint without bubbles. However, the mechanical performance of the hybrid plastics-metal joint without bubbles is still unknown, and systematic comparison between the hybrid joints with and without bubbles is lacking in literature. This becomes the objective of this study. In this work, the laser process parameters were carefully chosen from a preliminary study, such that different hybrid joints: with and without bubbles can be produced and compared. Biocompatible PET and commercially pure Ti were selected as materials for laser joining.
Resumo:
Corrosion fatigue is a fracture process as a consequence of synergistic interactions between the material structure, corrosive environment and cyclic loads/strains. It is difficult to be detected and can cause unexpected failure of engineering components in use. This study reveals a comparison of corrosion fatigue behaviour of laser-welded and bare NiTi wires using bending rotation fatigue (BRF) test coupled with a specifically-designed corrosion cell. The testing medium was Hanks’ solution (simulated body fluid) at 37.5 oC. Electrochemical impedance spectroscopic (EIS) measurement was carried out to monitor the change of corrosion resistance of sample during the BRF test at different periods of time. Experiments indicate that the laser-welded NiTi wire would be more susceptible to the corrosion fatigue attack than the bare NiTi wire. This study can serve as a benchmark for the product designers and engineers to understand the corrosion fatigue behaviour of the NiTi laser weld joint and determine the fatigue life safety factor for NiTi medical devices/implants involving laser welding in the fabrication process.