326 resultados para Controller medications
Resumo:
Objectives: Quality of life (QOL) is reportedly poor in children with Crohn disease (CD) but improves with increasing disease duration. This article aims to detail QOL in a cohort of Australian children with CD in relation to disease duration, disease activity, and treatment. MATERIALS AND METHODS: QOL, assessed using the IMPACT-III questionnaire, and disease activity measures, assessed using the Pediatric Crohn's Disease Activity Index (PCDAI), were available in 41 children with CD. For this cohort, a total of 186 measurements of both parameters were available. Results: QOL was found to be significantly lower, and disease activity significantly higher (F = 31.1, P = 0.00), in patients within 6 months of their diagnosis compared with those up to 2.5 years, up to 5 years, and beyond 5 years since diagnosis. Higher disease activity was associated with poorer QOL (r =-0.51, P = 0.00). Total QOL was highest in children on nil medications and lowest in children on enteral nutrition. The PCDAI (t =-6.0, P = 0.00) was a significant predictor of QOL, with the clinical history (t =-6.9, P = 0.00) and examination (t =-2.9, P = 0.01) sections of the PCDAI significantly predicting QOL. Disease duration, age, or sex was neither related to nor significant predictors of QOL, but height z score and type of treatment approached significance. Conclusions: Children with CD within 6 months of their diagnosis have impaired QOL compared with those diagnosed beyond 6 months. These patients, along with those with growth impairment, ongoing elevated disease activity with abdominal pain, diarrhoea and/or perirectal and extraintestinal complications, may benefit from regular assessments of QOL as part of their clinical treatment. © 2010 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.
Resumo:
Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimer's disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10 -7. In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10 -11) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10 -11). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10 -7) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10 -7); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia.
Resumo:
Objective. To assess the cost-effectiveness of bone density screening programmes for osteoporosis. Study design. Using published and locally available data regarding fracture rates and treatment costs, the overall costs per fracture prevented, cost per quality of life year (QALY) saved and cost per year of life gained were estimated for different bone density screening and osteoporosis treatment programmes. Main outcome measures. Cost per fracture prevented, cost per QALY saved, and cost per year of life gained. Results. In women over the age of 50 years, the costs per fracture prevented of treating all women with hormone replacement therapy, or treating only if osteoporosis is demonstrated on bone density screening were £32,594 or £23,867 respectively. For alendronate therapy for the same groups, the costs were £171,067 and £14,067 respectively. Once the background rate of treatment with alendronate reaches 18%, bone density screening becomes cost-saving. Costs estimates per QALY saved ranged from £1,514 to £39,076 for osteoporosis treatment with alendronate following bone density screening. Conclusions. For relatively expensive medications such as alendronate, treatment programmes with prior bone density screening are far more cost effective than those without, and in some circumstances become cost-saving. Costs per QALY of life saved and per year of life gained for osteoporosis treatment with prior bone density screening compare favourably with treatment of hypertension and hypercholesterolemia.
Resumo:
A number of hurdles must be overcome in order to integrate unmanned aircraft into civilian airspace for routine operations. The ability of the aircraft to land safely in an emergency is essential to reduce the risk to people, infrastructure and aircraft. To date, few field-demonstrated systems have been presented that show online re-planning and repeatability from failure to touchdown. This paper presents the development of the Guidance, Navigation and Control (GNC) component of an Automated Emergency Landing System (AELS) intended to address this gap, suited to a variety of fixed-wing aircraft. Field-tested on both a fixed-wing UAV and Cessna 172R during repeated emergency landing experiments, a trochoid-based path planner computes feasible trajectories and a simplified control system executes the required manoeuvres to guide the aircraft towards touchdown on a predefined landing site. This is achieved in zero-thrust conditions with engine forced to idle to simulate failure. During an autonomous landing, the controller uses airspeed, inertial and GPS data to track motion and maintains essential flight parameters to guarantee flyability, while the planner monitors glide ratio and re-plans to ensure approach at correct altitude. Simulations show reliability of the system in a variety of wind conditions and its repeated ability to land within the boundary of a predefined landing site. Results from field-tests for the two aircraft demonstrate the effectiveness of the proposed GNC system in live operation. Results show that the system is capable of guiding the aircraft to close proximity of a predefined keyhole in nearly 100% of cases.
Resumo:
This paper presents a motion control system for guidance of an underactuated Unmanned Underwater Vehicle (UUV) on a helical trajectory. The control strategy is developed using Port-Hamiltonian theory and interconnection and damping assignment passivity-based control. Using energy routing, the trajectory of a virtual fully actuated plant is guided onto a vector field. A tracking controller is then used that commands the underactuated plant to follow the velocity of the virtual plant. An integral control is inserted between the two control layers, which adds robustness and disturbance rejection to the design.
Resumo:
A gyrostabiliser control system and method for stabilising marine vessel motion based on precession information only. The control system employs an Automatic Gain Control (AGC) precession controller (60). This system operates with a gain factor that is always being gradually minimized so as to let the gyro flywheel (12) develop as much precession as possible - the higher the precession, the higher the roll stabilising moment. This continuous gain change provides adaptation to changes in sea state and sailing conditions. The system effectively predicts the likelihood of maximum precession being reached. Should this event be detected, then the gain is rapidly increased so as to provide a breaking precession torque. Once the event has passed, the system again attempts to gradually decrease the gain.
Resumo:
This paper presents a Hamiltonian model of marine vehicle dynamics in six degrees of freedom in both body-fixed and inertial momentum coordinates. The model in body-fixed coordinates presents a particular structure of the mass matrix that allows the adaptation and application of passivity-based control interconnection and damping assignment design methodologies developed for robust stabilisation of mechanical systems in terms of generalised coordinates. As an example of application, we follow this methodology to design a passivity-based tracking controller with integral action for fully actuated vehicles in six degrees of freedom. We also describe a momentum transformation that allows an alternative model representation that resembles general port-Hamiltonian mechanical systems with a coordinate dependent mass matrix. This can be seen as an enabling step towards the adaptation of the theory of control of port-Hamiltonian systems developed in robotic manipulators and multi-body mechanical systems to the case of marine craft dynamics.
Resumo:
Aim: The purpose of this study was to determine the percentage of patients assessed as malnourished using the Subjective Global Assessment in two hospitals in Ho Chi Minh City and Can Tho across multiple wards; and to investigate the association with factors including gender, age, days since admission, medical diagnosis and number of medications used. Methods: This cross-sectional study involved 205 inpatients from a hospital in Ho Chi Minh City and 78 inpatients and 89 outpatients from a hospital in Can Tho. Malnutrition status was assessed using Subjective Global Assessment. Ward, gender, age, medical diagnosis, time since admission and medication number were extracted from medical records. Results: 35.6% of inpatients and 9.0% of outpatients were malnourished. Multivariate analysis revealed factors predicting malnutrition status within inpatients (OR (95%CI)) were: age (OR = 1.03 (1.01-1.06)); cancer diagnosis (OR = 34.25 (3.16-370.89)); respiratory ward (11.49 (1.05-125.92)); or general medicine ward (20.34 (2.10-196.88)). Conclusions: Results indicate that malnutrition is a common problem in hospitals in Vietnam. Further research is needed to confirm this finding across a wider range of hospitals and to investigate the feasibility and efficacy of implementation of nutrition interventions in hospital settings.
Resumo:
In this paper, the trajectory tracking control of an autonomous underwater vehicle (AUVs) in six-degrees-of-freedom (6-DOFs) is addressed. It is assumed that the system parameters are unknown and the vehicle is underactuated. An adaptive controller is proposed, based on Lyapunov׳s direct method and the back-stepping technique, which interestingly guarantees robustness against parameter uncertainties. The desired trajectory can be any sufficiently smooth bounded curve parameterized by time even if consist of straight line. In contrast with the majority of research in this field, the likelihood of actuators׳ saturation is considered and another adaptive controller is designed to overcome this problem, in which control signals are bounded using saturation functions. The nonlinear adaptive control scheme yields asymptotic convergence of the vehicle to the reference trajectory, in the presence of parametric uncertainties. The stability of the presented control laws is proved in the sense of Lyapunov theory and Barbalat׳s lemma. Efficiency of presented controller using saturation functions is verified through comparing numerical simulations of both controllers.
Resumo:
Ramp metering (RM) is an access control for motorways, in which a traffic signal is placed at on-ramps to regulate the rate of vehicles entering the motorway and thus to preserve the motorway capacity. In general, RM algorithms fall into two categories by their effective scope: local control and coordinated control. Local control algorithm determines the metering rate based on the traffic condition on adjacent motorway mainline and the on-ramp. Conversely, coordinated RM strategies make use of measurements from the entire motorway network to operate individual ramp signals for optimal performance at the network level. This study proposes a multi-hierarchical strategy for on-ramp coordination. The strategy is structured in two layers. At the higher layer, a centralised, predictive controller plans the coordination control within a long update interval based on the location of high-risk breakdown flow. At the lower layer, reactive controllers determine the metering rates of those ramps involved in the ramp coordination with a short update interval. This strategy is modelled and applied to the northbound model of the Pacific Motorway in a micro-simulation platform (AIMSUN). The simulation results show that the proposed strategy effectively delays the onset of congestion and reduces total congestion with better managed on-ramp queues.
Resumo:
Background The environment is inextricably related to mental health. Recent research replicates findings of a significant, linear correlation between a childhood exposure to the urban environment and psychosis. Related studies also correlate the urban environment and aberrant brain morphologies. These findings challenge common beliefs that the mind and brain remain neutral in the face of worldly experience. Aim There is a signature within these neurological findings that suggests that specific features of design cause and trigger mental illness. The objective in this article is to work backward from the molecular dynamics to identify features of the designed environment that may either trigger mental illness or protect against it. Method This review analyzes the discrete functions putatively assigned to the affected brain areas and a neurotransmitter called dopamine, which is the primary target of most antipsychotic medications. The intention is to establish what the correlations mean in functional terms, and more specifically, how this relates to the phenomenology of urban experience. In doing so, environmental mental illness risk factors are identified. Conclusions Having established these relationships, the review makes practical recommendations for those in public health who wish to use the environment itself as a tool to improve the mental health of a community through design.
Resumo:
Introduction: Statins alone often do not reduce LDL cholesterol levels sufficiently to given maximum cardiovascular benefit. Thus, additional drugs are required to reduce the levels of LDL cholesterol. Monoclonal antibodies to PCSK9 have recently been shown to decrease LDL cholesterol, but it is not known whether they improve cardiovascular outcomes. Areas covered: Evaluation of two clinical trials reporting cardiovascular outcomes with antibodies to PCSK9; the OSLER extension with evolocumab and the ODYSSEY LONG TERM trial with alirocumab. Expert opinion: In OSLER and ODYSSEY LONG TERM, there were very few cardiovascular outcomes, but the trials do suggest that evolocumab and alirocumab may reduce these outcomes. However, there are also some safety concerns with both of these antibodies. Large clinical outcome trials are underway with both evolocumab and alirocumab, which will probably clarify both the safety concerns and any cardiovascular benefits with these antibodies. In our opinion, these antibodies may be suitable for use in subjects with familial hypercholesterolemia, who are uncontrolled with their present medications, provided intensive safety and cardiovascular monitoring is being undertaken. However, evolocumab and alirocumab should be used with caution in other subjects, until outcome studies in higher numbers of subjects, have shown acceptable safety and cardiovascular profiles.
Resumo:
Aims To observe medication solid dosage form modification in aged care facilities (ACFs), and assess staff levels of self-perceived knowledge of medication modification and the types of resources available to them. Method Observation of medication rounds in a convenience sample of Australian Capital Territory ACFs and assessment of staff knowledge of dosage form modification and available resources. Results From 160 observations across six medication rounds, 29 residents had a total of 75 medications modified by the nursing staff prior to administration, with 32% of these instances identified as inappropriate. The methods used for crushing and administration resulted in drug mixing, spillage and incomplete dosing. The staff reported adequate resources; however, a lack of knowledge on how to locate and use these resources was evident. Conclusions Improved staff training on how to use available resources is needed to reduce the observed high incidence of inappropriate medication crushing.
Resumo:
Sample medications represented 4 (3.8 million Australian dollars) of the Australian general practice promotional budget of pharmaceutical companies in the second quarter of 2005. In the United States, general practitioners have been shown to use sample medication in up to 20 of encounters both for commencing and for full treatment. Given the USA does not have a universal subsidy for medications like Australia, sample use may be higher than Australian GPs operating with the Pharmaceutical Benefits Scheme. Australian GPs perceive benefits for samples as a trial run: to test patient tolerability, enhance patient satisfaction, and for those who cannot afford multiple trials of drugs. Acceptance of samples by GPs is associated with preference for and rapid prescription of new drugs and positive attitudes toward pharmaceutical representatives. Concerns with sample medications include prescribing medication that is not the GP's preferred choice owing to the limited range of samples available. Other concerns include dispensing expired medication and wastage of medications.
Resumo:
Objective: In Australian residential aged care facilities (RACFs), the use of certain classes of high-risk medication such as antipsychotics, potent analgesics, and sedatives is high. Here, we examined the prescribed medications and subsequent changes recommended by geriatricians during comprehensive geriatric consultations provided to residents of RACFs via videoconference. Design: This is a prospective observational study. Setting: Four RACFs in Queensland, Australia, are included. Participants: A total of 153 residents referred by general practitioners for comprehensive assessment by geriatricians delivered by video-consultation. Results: Residents’ mean (standard deviation, SD) age was 83.0 (8.1) years and 64.1% were female. They had multiple comorbidities (mean 6), high levels of dependency, and were prescribed a mean (SD) of 9.6 (4.2) regular medications. Ninety-one percent of patients were taking five or more medications daily. Of total medications prescribed (n=1,469), geriatricians recommended withdrawal of 9.8% (n=145) and dose alteration of 3.5% (n=51). New medications were initiated in 47.7% (n=73) patients. Of the 10.3% (n=151) medications considered as high risk, 17.2% were stopped and dose altered in 2.6%. Conclusion: There was a moderate prevalence of potentially inappropriate high-risk medications. However, geriatricians made relatively few changes, suggesting either that, on balance, prescription of these medications was appropriate or, because of other factors, there was a reluctance to adjust medications. A structured medication review using an algorithm for withdrawing medications of high disutility might help optimize medications in frail patients. Further research, including a broader survey, is required to understand these dynamics.