232 research outputs found

    Regular dendritic patterns induced by non-local time-periodic forcing

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    The dynamic response of dendritic solidification to spatially homogeneous time-periodic forcing has been studied. Phase-field calculations performed in two dimensions (2D) and experiments on thin (quasi 2D) liquid crystal layers show that the frequency of dendritic side-branching can be tuned by oscillatory pressure or heating. The sensitivity of this phenomenon to the relevant parameters, the frequency and amplitude of the modulation, the initial undercooling and the anisotropies of the interfacial free energy and molecule attachment kinetics, has been explored. It has been demonstrated that besides the side-branching mode synchronous with external forcing as emerging from the linear Wentzel-Kramers-Brillouin analysis, modes that oscillate with higher harmonic frequencies are also present with perceptible amplitudes.Comment: 15 pages, 23 figures, Submitted to Phys. Rev.

    Candidiasis : predisposing factors, prevention, diagnosis and alternative treatment

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    Candidiasis is the most common opportunistic yeast infection. Candida species and other microorganisms are involved in this complicated fungal infection, but Candida albicans continues to be the most prevalent. In the past two decades, it has been observed an abnormal overgrowth in the gastrointestinal, urinary and respiratory tracts, not only in immunocompromised patients, but also related to nosocomial infections and even in healthy individuals. There is a widely variety of causal factors that contribute to yeast infection which means that candidiasis is a good example of a multifactorial syndrome. Due to rapid increase in the incidence in these infections, this is the subject of numerous studies. Recently, the focus of attention is the treatment and, above all, the prevention of those complications. The diagnosis of candidiasis could become quite complicated. Prevention is the most effective “treatment,” much more than eradication of the yeast with antifungal agents. There are several aspects to consider in the daily routine that can provide a strength protection. However, a therapeutic approach is necessary when the infection is established, and therefore, other alternatives should be explored. This review provides an overview on predisposition factors, prevention and diagnosis of candidiasis, highlighting alternative approaches for candidiasis treatment.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) for N. Martins grant (SFRH/BD/87658/2012), L. Barros researcher contract under "Programa Compromisso com Ciencia-2008'' and financial support to the research center CIMO (strategic project PEst-OE/AGR/UI0690/2011)

    Estimation of the burden of cardiovascular disease attributable to modifiable risk factors and cost-effectiveness analysis of preventative interventions to reduce this burden in Argentina

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    Background. Cardiovascular disease (CVD) is the primary cause of mortality and morbidity in Argentina representing 34.2% of deaths and 12.6% of potential years of life lost (PYLL). The aim of the study was to estimate the burden of acute coronary heart disease (CHD) and stroke and the cost-effectiveness of preventative population-based and clinical interventions. Methods. An epidemiological model was built incorporating prevalence and distribution of high blood pressure, high cholesterol, hyperglycemia, overweight and obesity, smoking, and physical inactivity, obtained from the Argentine Survey of Risk Factors dataset. Population Attributable Fraction (PAF) of each risk factor was estimated using relative risks from international sources. Total fatal and non-fatal events, PYLL and Disability Adjusted Life Years (DALY) were estimated. Costs of event were calculated from local utilization databases and expressed in international dollars (I).Incrementalcost−effectivenessratios(ICER)wereestimatedforsixinterventions:reducingsaltinbread,massmediacampaigntopromotetobaccocessation,pharmacologicaltherapyofhighbloodpressure,pharmacologicaltherapyofhighcholesterol,tobaccocessationtherapywithbupropion,andamultidrugstrategyforpeoplewithanestimatedabsoluterisk>20). Incremental cost-effectiveness ratios (ICER) were estimated for six interventions: reducing salt in bread, mass media campaign to promote tobacco cessation, pharmacological therapy of high blood pressure, pharmacological therapy of high cholesterol, tobacco cessation therapy with bupropion, and a multidrug strategy for people with an estimated absolute risk > 20% in 10 years. Results. An estimated total of 611,635 DALY was lost due to acute CHD and stroke for 2005. Modifiable risk factors explained 71.1% of DALY and more than 80% of events. Two interventions were cost-saving: lowering salt intake in the population through reducing salt in bread and multidrug therapy targeted to persons with an absolute risk above 20% in 10 years; three interventions had very acceptable ICERs: drug therapy for high blood pressure in hypertensive patients not yet undergoing treatment (I 2,908 per DALY saved), mass media campaign to promote tobacco cessation amongst smokers (I3,186perDALYsaved),andloweringcholesterolwithstatindrugtherapy(I 3,186 per DALY saved), and lowering cholesterol with statin drug therapy (I 14,432 per DALY saved); and one intervention was not found to be cost-effective: tobacco cessation with bupropion (I$ 59,433 per DALY saved). Conclusions. Most of the interventions selected were cost-saving or very cost-effective. This study aims to inform policy makers on resource-allocation decisions to reduce the burden of CVD in Argentina.Centro de Endocrinología Experimental y Aplicada (CENEXA

    Improving the cost-effectiveness of cardiovascular disease prevention in Australia : a modelling study

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    Background : Cardiovascular disease is the leading cause of death worldwide. Like many countries, Australia is currently changing its guidelines for cardiovascular disease prevention from drug treatment for everyone with \u27high blood pressure\u27 or \u27high cholesterol\u27, to prevention based on a patient\u27s absolute risk. In this research, we model cost-effectiveness of cardiovascular disease prevention with blood pressure and lipid drugs in Australia under three different scenarios: (1) the true current practice in Australia; (2) prevention as intended under the current guidelines; and (3) prevention according to proposed absolute risk levels. We consider the implications of changing to absolute risk-based cardiovascular disease prevention, for the health of the Australian people and for Government health sector expenditure over the long term. Methods : We evaluate cost-effectiveness of statins, diuretics, ACE inhibitors, calcium channel blockers and beta-blockers, for Australian men and women, aged 35 to 84 years, who have never experienced a heart disease or stroke event. Epidemiological changes and health care costs are simulated by age and sex in a discrete time Markov model, to determine total impacts on population health and health sector costs over the lifetime, from which we derive cost-effectiveness ratios in 2008 Australian dollars per quality-adjusted life year. Results : Cardiovascular disease prevention based on absolute risk is more cost-effective than prevention under the current guidelines based on single risk factor thresholds, and is more cost-effective than the current practice, which does not follow current clinical guidelines. Recommending blood pressure-lowering drugs to everyone with at least 5% absolute risk and statin drugs to everyone with at least 10% absolute risk, can achieve current levels of population health, while saving 5.4billionfortheAustralianGovernmentoverthelifetimeofthepopulation.Butsavingscouldbeashighas5.4 billion for the Australian Government over the lifetime of the population. But savings could be as high as 7.1 billion if Australia could match the cheaper price of statin drugs in New Zealand. Conclusions : Changing to absolute risk-based cardiovascular disease prevention is highly recommended for reducing health sector spending, but the Australian Government must also consider measures to reduce the cost of statin drugs, over and above the legislated price cuts of November 2010. <br /

    Powder Compaction: Compression Properties of Cellulose Ethers

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    Effective development of matrix tablets requires a comprehensive understanding of different raw material attributes and their impact on process parameters. Cellulose ethers (CE) are the most commonly used pharmaceutical excipients in the fabrication of hydrophilic matrices. The innate good compression and binding properties of CE enable matrices to be prepared using economical direct compression (DC) techniques. However, DC is sensitive to raw material attributes, thus, impacting the compaction process. This article critically reviews prior knowledge on the mechanism of powder compaction and the compression properties of cellulose ethers, giving timely insight into new developments in this field

    Phosphorylated DegU Manipulates Cell Fate Differentiation in the <i>Bacillus subtilis</i> Biofilm<em/>

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    Cell differentiation is ubiquitous and facilitates division of labor and development. Bacteria are capable of multicellular behaviors that benefit the bacterial community as a whole. A striking example of bacterial differentiation occurs throughout the formation of a biofilm. During Bacillus subtilis biofilm formation, a subpopulation of cells differentiates into a specialized population that synthesizes the exopolysaccharide and the TasA amyloid components of the extracellular matrix. The differentiation process is indirectly controlled by the transcription factor Spo0A that facilitates transcription of the eps and tapA (tasA) operons. DegU is a transcription factor involved in regulating biofilm formation. Here, using a combination of genetics and live single-cell cytological techniques, we define the mechanism of biofilm inhibition at high levels of phosphorylated DegU (DegU∌P) by showing that transcription from the eps and tapA promoter regions is inhibited. Data demonstrating that this is not a direct regulatory event are presented. We demonstrate that DegU∌P controls the frequency with which cells activate transcription from the operons needed for matrix biosynthesis in favor of an off state. Subsequent experimental analysis led us to conclude that DegU∌P functions to increase the level of Spo0A∌P, driving cell fate differentiation toward the terminal developmental process of sporulation

    A New Model of Delirium Care in the Acute Geriatric Setting: Geriatric Monitoring Unit

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    <p>Abstract</p> <p>Background</p> <p>Delirium is a common and serious condition, which affects many of our older hospitalised patients. It is an indicator of severe underlying illness and requires early diagnosis and prompt treatment, associated with poor survival, functional outcomes with increased risk of institutionalisation following the delirium episode in the acute care setting. We describe a new model of delirium care in the acute care setting, titled Geriatric Monitoring Unit (GMU) where the important concepts of delirium prevention and management are integrated. We hypothesize that patients with delirium admitted to the GMU would have better clinical outcomes with less need for physical and psychotropic restraints compared to usual care.</p> <p>Methods/Design</p> <p>GMU models after the Delirium Room with adoption of core interventions from Hospital Elder Life Program and use of evening bright light therapy to consolidate circadian rhythm and improve sleep in the elderly patients. The novelty of this approach lies in the amalgamation of these interventions in a multi-faceted approach in acute delirium management. GMU development thus consists of key considerations for room design and resource planning, program specific interventions and daily core interventions. Assessments undertaken include baseline demographics, comorbidity scoring, duration and severity of delirium, cognitive, functional measures at baseline, 6 months and 12 months later. Additionally we also analysed the pre and post-GMU implementation knowledge and attitude on delirium care among staff members in the geriatric wards (nurses, doctors) and undertook satisfaction surveys for caregivers of patients treated in GMU.</p> <p>Discussion</p> <p>This study protocol describes the conceptualization and implementation of a specialized unit for delirium management. We hypothesize that such a model of care will not only result in better clinical outcomes for the elderly patient with delirium compared to usual geriatric care, but also improved staff knowledge and satisfaction. The model may then be transposed across various locations and disciplines in the acute hospital where delirious patients could be sited.</p> <p>Trial Registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN52323811">ISRCTN52323811</a></p

    Duodenal carcinoma at the ligament of Treitz. A molecular and clinical perspective

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    Background There is very small occurrence of adenocarcinoma in the small bowel. We present a case of primary duodenal adenocarcinoma and discuss the findings of the case diagnostic modalities, current knowledge on the molecular biology behind small bowel neoplasms and treatment options. Case The patient had a history of iron deficiency anemia and occult bleeding with extensive workup consisting of upper endoscopy, colonoscopy, capsule endoscopy, upper gastrointestinal series with small bowel follow through and push enteroscopy. Due to persistent abdominal pain and iron deficiency anemia the patient underwent push enteroscopy which revealed adenocarcinoma of the duodenum. The patient underwent en-bloc duodenectomy which revealed T3N1M0 adenocarcinoma of the 4th portion of the duodenum. Conclusions Primary duodenal carcinoma, although rare should be considered in the differential diagnosis of occult gastrointestinal bleeding when evaluation of the lower and upper GI tract is unremarkable. We discuss the current evaluation and management of this small bowel neoplasm

    Functional tissue engineering of ligament healing

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    Ligaments and tendons are dense connective tissues that are important in transmitting forces and facilitate joint articulation in the musculoskeletal system. Their injury frequency is high especially for those that are functional important, like the anterior cruciate ligament (ACL) and medial collateral ligament (MCL) of the knee as well as the glenohumeral ligaments and the rotator cuff tendons of the shoulder. Because the healing responses are different in these ligaments and tendons after injury, the consequences and treatments are tissue- and site-specific. In this review, we will elaborate on the injuries of the knee ligaments as well as using functional tissue engineering (FTE) approaches to improve their healing. Specifically, the ACL of knee has limited capability to heal, and results of non-surgical management of its midsubstance rupture have been poor. Consequently, surgical reconstruction of the ACL is regularly performed to gain knee stability. However, the long-term results are not satisfactory besides the numerous complications accompanied with the surgeries. With the rapid development of FTE, there is a renewed interest in revisiting ACL healing. Approaches such as using growth factors, stem cells and scaffolds have been widely investigated. In this article, the biology of normal and healing ligaments is first reviewed, followed by a discussion on the issues related to the treatment of ACL injuries. Afterwards, current promising FTE methods are presented for the treatment of ligament injuries, including the use of growth factors, gene delivery, and cell therapy with a particular emphasis on the use of ECM bioscaffolds. The challenging areas are listed in the future direction that suggests where collection of energy could be placed in order to restore the injured ligaments and tendons structurally and functionally

    Which interventions offer best value for money in primary prevention of cardiovascular disease?

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    BackgroundDespite many decades of declining mortality rates in the Western world, cardiovascular disease remains the leading cause of death worldwide. In this research we evaluate the optimal mix of lifestyle, pharmaceutical and population-wide interventions for primary prevention of cardiovascular disease.Methods and FindingsIn a discrete time Markov model we simulate the ischaemic heart disease and stroke outcomes and cost impacts of intervention over the lifetime of all Australian men and women, aged 35 to 84 years, who have never experienced a heart disease or stroke event. Best value for money is achieved by mandating moderate limits on salt in the manufacture of bread, margarine and cereal. A combination of diuretic, calcium channel blocker, ACE inhibitor and low-cost statin, for everyone with at least 5% five-year risk of cardiovascular disease, is also cost-effective, but lifestyle interventions aiming to change risky dietary and exercise behaviours are extremely poor value for money and have little population health benefit.ConclusionsThere is huge potential for improving efficiency in cardiovascular disease prevention in Australia. A tougher approach from Government to mandating limits on salt in processed foods and reducing excessive statin prices, and a shift away from lifestyle counselling to more efficient absolute risk-based prescription of preventive drugs, could cut health care costs while improving population health.<br /
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