13,892 research outputs found
Global Continua of Positive Equilibria for some Quasilinear Parabolic Equation with a Nonlocal Initial Condition
This paper is concerned with a quaslinear parabolic equation including a
nonlinear nonlocal initial condition. The problem arises as equilibrium
equation in population dynamics with nonlinear diffusion. We make use of global
bifurcation theory to prove existence of an unbounded continuum of positive
solutions
An examination of factors influencing the choice of therapy for patients with coronary artery disease
Background A diverse range of factors influence clinicians' decisions regarding the allocation of patients to different treatments for coronary artery disease in routine cardiology clinics. These include demographic measures, risk factors, co-morbidities, measures of objective cardiac disease, symptom reports and functional limitations. This study examined which of these factors differentiated patients receiving angioplasty from medication; bypass surgery from medication; and bypass surgery from angioplasty. Methods Univariate and multivariate logistic regression analyses were conducted on patient data from 214 coronary artery disease patients who at the time of recruitment had been received a clinical assessment and were reviewed by their cardiologist in order to determine the form of treatment they were to undergo: 70 would receive/continue medication, 71 were to undergo angioplasty and 73 were to undergo bypass surgery. Results Analyses differentiating patients receiving angioplasty from medication produced 9 significant univariate predictors, of which 5 were also multivariately significant (left anterior descending artery disease, previous coronary interventions, age, hypertension and frequency of angina). The analyses differentiating patients receiving surgery from angioplasty produced 12 significant univariate predictors, of which 4 were multivariately significant (limitations in mobility range, circumflex artery disease, previous coronary interventions and educational level). The analyses differentiating patients receiving surgery from medication produced 14 significant univariate predictors, of which 4 were multivariately significant (left anterior descending artery disease, previous cerebral events, limitations in mobility range and circumflex artery disease). Conclusion Variables emphasised in clinical guidelines are clearly involved in coronary artery disease treatment decisions. However, variables beyond these may also be important factors when therapy decisions are undertaken thus their roles require further investigation
Cardio-Oncology - A new subspecialty with collaboration at its heart
Cardio-Oncology is the care of cancer patients with cardiovascular disease, overt or occult, already established or acquired during treatment. Cancer patients can present with a variety of cardiovascular problems not all of which are directly related to cancer therapy (medications or radiotherapy). The cardiovascular problems of oncology patients can range from ischaemia to arrhythmias and can also include valve problems and heart failure. As such, within cardiology, teamwork is required with members of different cardiology subspecialties. The way forward will be to adopt a multidisciplinary approach to produce optimal individual care. Close collaboration between cardiology and oncology specialists in a Cardio-Oncology setting can make this happe
Investigation of phase separation within the generalized Lin-Taylor model for a binary liquid mixture of large hexagonal and small triangular particles
The generalized Lin-Taylor model defined on the hexagonal lattice is used to
investigate the phase separation in an asymmetric binary liquid mixture
consisting of large A (hexagons) and small B (triangles) particles. By
considering interaction energies between A-A and A-B pairs of particles that
occupy nearest-neighbour cells of the hexagonal lattice, we have derived an
exact solution for the considered model system having established a mapping
correspondence with the two-dimensional Ising model on its dual triangular
lattice. Altogether, six different types of coexistence curves including those
with reentrant miscibility regions (i.e. closed-loop coexistence curves) were
found in dependence on the relative strength between both coupling constants.Comment: 8 pages, 4 figures, presented at 7th Liblice conference on the
Statistical Mechanics of Liquids to be held in Lednice on June 11-16, 200
Expression of the arsenite oxidation regulatory operon in Rhizobium sp. str. NT-26 is under the control of two promoters that respond to different environmental cues
Rhizobium sp. str. NT-26 is a gram-negative facultative chemolithoautotrophic arsenite oxidiser that has been used as a model organism to study various aspects of arsenite oxidation including the regulation of arsenite oxidation. The three regulatory genes, aioX, aioS and aioR, are co-transcribed when NT-26 was grown in the presence or absence of arsenite. The aioXSR operon is up-regulated in stationary phase but not by the presence of arsenite in the growth medium. The two transcription start sites upstream of aioX were determined which led to the identification of two promoters, the housekeeping promoter RpoD and the growth-phase dependent promoter RpoE2. Promoter-lacZ fusions confirmed their constitutive and stationary phase expressions. The involvement of the NT-26 sigma factor RpoE2 in acting on the NT-26 RpoE2 promoter was confirmed in vivo in E. coli, which lacks a rpoE2 homologue, using a strain carrying both the promoter-lacZ fusion and the NT-26 rpoE2 gene. An in silico approach was used to search for other RpoE2 promoters and AioR-binding motifs and led to the identification of other genes that could be regulated by these proteins including those involved in quorum sensing, chemotaxis and motility expanding the signalling networks important for the microbial metabolism of arsenite
Recommended from our members
Prevalence of Gastroesophageal Reflux in Cats During Anesthesia and Effect of Omeprazole on Gastric pH.
BackgroundGastroesophageal reflux (GER) is poorly characterized in anesthetized cats, but can cause aspiration pneumonia, esophagitis, and esophageal stricture formation.ObjectiveTo determine whether pre-anesthetic orally administered omeprazole increases gastric and esophageal pH and increases serum gastrin concentrations in anesthetized cats, and to determine the prevalence of GER using combined multichannel impedance and pH monitoring.AnimalsTwenty-seven healthy cats undergoing elective dental procedures.MethodsProspective, double-masked, placebo-controlled, randomized clinical trial. Cats were randomized to receive 2 PO doses of omeprazole (1.45-2.20 mg/kg) or an empty gelatin capsule placebo 18-24 hours and 4 hours before anesthetic induction. Blood for measurement of serum gastrin concentration was collected during anesthetic induction. An esophageal pH/impedance catheter was utilized to continuously measure esophageal pH and detect GER throughout anesthesia.ResultsMean gastric pH in the cats that received omeprazole was 7.2 ± 0.4 (range, 6.6-7.8) and was significantly higher than the pH in cats that received the placebo 2.8 ± 1.0 (range, 1.3-4.1; P < .001). Omeprazole administration was not associated with a significant increase in serum gastrin concentration (P = .616). Nine of 27 cats (33.3%) had ≥1 episode of GER during anesthesia.Conclusions and clinical relevancePre-anesthetic administration of 2 PO doses of omeprazole at a dosage of 1.45-2.20 mg/kg in cats was associated with a significant increase in gastric and esophageal pH within 24 hours, but was not associated with a significant increase in serum gastrin concentration. Prevalence of reflux events in cats during anesthesia was similar to that of dogs during anesthesia
Entrectinib-related myocarditis in a young female patient with metastatic non-small cell lung cancer
A 51-year-old woman presented with a 2-week history of off balance, left lower limb weakness and neglect and neck pain radiating down the right arm. Investigations revealed a metastatic, ROS1 fusion-positive, non-small cell lung cancer, and treatment with entrectinib, a recently approved multikinase inhibitor, was started. Two weeks after, she was admitted to the emergency department with new-onset pressure-like chest pain and dyspnoea. Laboratory evaluation showed elevated troponin and mild left ventricular systolic dysfunction with reduced global longitudinal strain on transthoracic echocardiogram. Cardiac magnetic resonance revealed mild oedema and non-ischaemic fibrosis. A diagnosis of drug-induced myocarditis was made. Cardioprotective medication with an angiotensin-converting enzyme inhibitor and a beta-blocker was started. Entrectinib was temporarily discontinued and restarted at a reduced dose after a multidisciplinary team meeting involving both the oncology and cardio-oncology teams. This is the second described case of entrectinib-induced myocarditis and the first one without eosinophilia
Cardio-oncology for the general physician: 'old' and 'new' cardiovascular toxicities and how to manage them
Cardio-oncology is the care of cancer patients with cardiovascular disease. The need for a dedicated subspecialty emerged to address heart failure caused by drugs such as anthracyclines and anti-human epidermal growth factor receptor 2 (HER2) therapies, but over time has expanded into an exciting subspecialty with widening horizons. While still dealing with a lot of commonly recognised toxicities, such as heart failure, hypertension and coronary disease, new and revolutionary cancer therapies have been associated with challenging cardiovascular complications, requiring specialist input to manage effectively. Echocardiography is a key investigation, with advanced techniques such as three-dimensional and strain assessment allowing more accurate diagnosis and earlier detection of subtle changes. Cardiac magnetic resonance and biomarkers are useful adjuncts to aid diagnosis and management. With increasing cancer incidence and improved cancer survival rates, it is important that general cardiologists and physicians are aware of cardiac complications associated with cancer and how to manage them
Effects of Projected Changes in Wind, Atmospheric Temperature, and Freshwater Inflow on the Ross Sea
A 5-km horizontal resolution regional ocean-sea ice-ice shelf model of the Ross Sea is used to examine the effects of changes in wind strength, air temperature, and increased meltwater input on the formation of high-salinity shelf water (HSSW), on-shelf transport and vertical mixing of Circumpolar Deep Water (CDW) and its transformation into modified CDW (MCDW), and basal melt of the Ross Ice Shelf (RIS). A 20% increase in wind speed, with no other atmospheric changes, reduced summer sea ice minimum area by 20%, opposite the observed trend of the past three decades. Increased winds with spatially uniform, reduced atmospheric temperatures increased summer sea ice concentrations, on-shelf transport of CDW, vertical mixing of MCDW, HSSW volume, and (albeit small) RIS basal melt. Winds and atmospheric temperatures from the SRES A1B scenario forcing of the MPI ECHAM5 model decreased on-shelf transport of CDW and vertical mixing of MCDW for 2046-61 and 2085-2100 relative to the end of the twentieth century. The RIS basal melt increased slightly by 2046-61 (9%) and 2085-2100 (13%). Advection of lower-salinity water onto the continental shelf did not significantly affect sea ice extent for the 2046-61 or 2085-2100 simulations. However, freshening reduces on-shelf transport of CDW, vertical mixing of MCDW, and the volume of HSSW produced. The reduced vertical mixing of MCDW, while partially balanced by the reduced on-shelf transport of CDW, enhances the RIS basal melt rate relative to the twentieth-century simulation for 2046-61 (13%) and 2085-2100 (17%)
- …