2,225 research outputs found
Auditory masking - A study of its physiological mechanism and of correlations between physiological and psychological observations First quarterly progress report, period ending 30 Jun. 1965
Psychological and physiological study of auditory maskin
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Heart rate and blood pressure monitoring in heart failure.
It has been long known that incessant tachycardia and severe hypertension can cause heart failure (HF). In recent years, it has also been recognized that more modest elevations in either heart rate (HR) or blood pressure (BP), if sustained, can be a risk factor both for the development of HF and for mortality in patients with established HF. Heart rate and BP are thus both modifiable risk factors in the setting of HF. What is less clear is the question whether routine systematic monitoring of these simple physiological parameters to a target value can offer clinical benefits. Measuring these parameters clinically during patient review is recommended in HF management in most HF guidelines, both in the acute and chronic phases of the disease. More sophisticated systems now allow long-term automatic or remote monitoring of HR and BP and whether this more detailed patient information can improve clinical outcomes will require prospective RCTs to evaluate. In addition, analysis of patterns of both HR and BP variability can give insights into autonomic function, which is also frequently abnormal in HF. This window into autonomic dysfunction in our HF patients can also provide further independent prognostic information and may in itself be target for future interventional therapies. This article, developed during a consensus meeting of the Heart Failure Association of the ESC concerning the role of physiological monitoring in the complex multi-morbid HF patient, highlights the importance of repeated assessment of HR and BP in HF, and reviews gaps in our knowledge and potential future directions
Renal function, electrolytes, and congestion monitoring in heart failure.
Congestion, renal function, and electrolyte imbalance (particularly potassium) are common problems in the management of the complex multi-morbid patient with heart failure (HF). Poor control of these fundamental clinical features is associated with adverse outcomes. Close monitoring of serum potassium and renal function is recommended by most current guidelines during the management of an episode of acute decompensated HF, yet the recommendations remain poorly implemented. Physicians are advised to treat a state of euvolaemia after an admission with decompensated HF and residual congestion is a marker of worse outcome, yet control of congestion is poorly assessed and managed in real-world practice. This document reflects the key points discussed by a panel of experts during a Heart Failure Association meeting on physiological monitoring of the complex multi-morbid HF patient, and here, we present to aspects related to renal function, electrolyte, and congestion monitoring
Periodicity of high-order functions in the CNS Final progress report, year ending 30 Jun. 1971
Analysis of cerebral slow potentials underlying human attentive processes in central nervous syste
Bovine Enteropathogenic Coronavirus: The Effect of the Host Cell and Trypsin Modification on the Virus Structure, Cytopathic Expression, and Infectivity.
Human rectal tumor-18 (HRT-18) cell clones 3F3, 3E3, D2, and 4B3 exhibited differences in cellular morphology in Giemsa-stained cultures and developing monolayers. Differences were evident in growth kinetics and plating efficiency of each clone. The clones produced colonies in soft agar, demonstrating anchorage independence. Cytopathic expression (CPE) including cytoplasmic vacuolization and cell fusion occurred in BCV-L9-infected clones 3F3, D2, and 3E3. Cell fusion was inapparent in clone 4B3. Bovine coronavirus strain L9 (BCV-L9) and 5 wild-type isolates replicated in HRT-18 cells, inducing cell fusion. Strain L9, exclusively, replicated in D2BFS cells, requiring trypsin to induce cell fusion. Strain L9 produced plaques in the HRT-18 clones, but the ease of plaque formation and plaque morphology was host cell dependent. Host cell-dependent plaque formation was demonstrated by wild-type BCV strains, and plaque morphology was strain dependent. The intensity of trypsin enhancement of CPE and plaque development depended on the virus strain and host cell. Trypsin greatly enhanced the infectivity of BCV-L9 in D2BFS and HRT-18 cells, and to lesser extents in clones 3F3, 3E3, and D2. Trypsin-enhanced infectivity was not detected in clone 4B3. The infectivity of strain LY-138 in HRT-18 cells was slightly enhanced by trypsin. Eleven structural proteins of BCV-L9 were detected by immunoblotting, including 185, 160, 140, 125, 110, 100, 52, 46, 37, 31-34, and 26-28 Kd species. Under reducing conditions 185, 140, and 100 Kd species migrated as 190, 65, and 95 Kd forms. Silver-stained proteins of 18, 20, and 23 Kd were reduced to a 20-23 Kd cluster. Host cell-dependent differences in the protein profile of L9 were detected. A 62 Kd protein was specific to L9 (D2BFS with trypsin). L9 (4B3) and L9 (D2) lacked the 46 and 110 Kd bands, respectively. Cleavage of the 185 Kd protein, an increase in the 100 Kd band, and conversion of the 31-34 Kd cluster to a 34 Kd band occurred when BCV-L9 was propagated in D2BFS cells with trypsin. Trypsin converted the reduced, 95 Kd protein found in L9 (HRT-18) to 90 Kd, and the 20-23 Kd cluster was altered to 19-23 Kd. In vitro trypsin treatment of L9 (3F3) resulted in cleavage of the 46 Kd molecule and the appearance of a 25 Kd species
Evaluation of a liquid chromatographic method for the determination of fumonisins in corn, poultry feed, and Fusarium culture material.
The performance of a liquid chromatographic method for determining fumonisins in corn, animal feeds, and culture material was evaluated. Efficiencies of extractions with the following solvent systems were determined: acetonitrile-water (50 + 50, v/v), methanol-water (75 + 25, v/v), and 100% water. The acetonitrile solvent gave both higher extraction efficiencies and faster extraction times than the other 2 solvents. Extraction was followed by C18 solid-phase extraction column cleanup. Fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) were measured by precolumn derivatization with o-phthalaldehyde followed by isocratic separation on a C18 reversed-phase column with a mobile phase of 50 mM potassium dihydrogen phosphate (pH 3.3)-acetonitrile (60 + 40). Commercially prepared poultry feed, corn, and Fusarium spp. corn cultures were analyzed at the following levels: FB1, 1.5 to 15,000 micrograms/g; FB2, 0.5 to 4000 micrograms/g; FB3, and 0.17 to 1,500 micrograms/g. Recoveries were 91-94%, 90-100%, and 81-93% for FB1, FB2, and FB3, respectively. Precision (coefficient of variation) was determined with pooled field samples and ranged from 2% at 19 micrograms/g for FB1 to 9% at 0.17 microgram/g for FB3. Time and pH studies of the formation of the fluorescent derivative and its stability were conducted. Complete reaction occurred at pHs above 7.9, with optimal pH for chromatography between 8.0 and 8.5. No statistically significant response differences were detected for reaction times ranging from 4 to 40 min; however, the detector signal was significantly reduced when reaction times were shorter than 4 min. Chromatograms of samples were free of interferences for all feeds, corn, and culture material teste
A Novel Method for Detecting Wild Boar Presence
Populations of wild boar and feral pigs (Sus scrofa) are increasing in numbers and distribution worldwide, in parallel with their significant environmental and economic impact. Reliable methods to detect the presence of this species are needed for monitoring its natural range expansion and its occurrence in areas where animals have been deliberately or accidentally introduced. The main aim of this study, carried out in English woodlands recently colonized by wild boar, was to assess the effectiveness of a birch wood tar-based compound, to detect the presence of this species in presence/absence surveys. A pilot trial in woodlands where wild boar had been established for circa 20 years found that wild boar sniffed and rubbed their bodies against stakes treated with this compound significantly more than against control stakes treated with water, thus confirming that the birch wood tar attracted wild boar to stakes. A second trial, carried out by applying the birch wood tar to trees in 8 woodlands surrounding the core range of wild boar, found that these animals left consistently more activity signs such as rubbing, tusk marks, and rooting on or around trees treated with this compound than on or around control trees treated with water. These results suggest that birch wood tar can be used as a method to confirm presence of wild boar in an area. Possible applications of this compound include its use to increase trapping efficiency or its deployment to confirm the success of a local eradication
Physiological and clinical consequences of relief of right ventricular outflow tract obstruction late after repair of congenital heart defects.
BACKGROUND: Right ventricular outflow tract obstruction (RVOTO) is a common problem after repair of congenital heart disease. Percutaneous pulmonary valve implantation (PPVI) can treat this condition without consequent pulmonary regurgitation or cardiopulmonary bypass. Our aim was to investigate the clinical and physiological response to relieving RVOTO. METHODS AND RESULTS: We studied 18 patients who underwent PPVI for RVOTO (72% male, median age 20 years) from a total of 93 who had this procedure for various indications. All had a right ventricular outflow tract (RVOT) gradient >50 mm Hg on echocardiography without important pulmonary regurgitation (less than mild or regurgitant fraction <10% on magnetic resonance imaging [MRI]). Cardiopulmonary exercise testing, tissue Doppler echocardiography, and MRI were performed before and within 50 days of PPVI. PPVI reduced RVOT gradient (51.4 to 21.7 mm Hg, P<0.001) and right ventricular systolic pressure (72.8 to 47.3 mm Hg, P<0.001) at catheterization. Symptoms and aerobic (25.7 to 28.9 mL.kg(-1).min(-1), P=0.002) and anaerobic (14.4 to 16.2 mL.kg(-1).min(-1), P=0.002) exercise capacity improved. Myocardial systolic velocity improved acutely (tricuspid 4.8 to 5.3 cm/s, P=0.05; mitral 4.7 to 5.5 cm/s, P=0.01), whereas isovolumic acceleration was unchanged. The tricuspid annular velocity was not maintained on intermediate follow-up. Right ventricular end-diastolic volume (99.9 to 89.7 mL/m2, P<0.001) fell, whereas effective stroke volume (43.7 to 48.3 mL/m2, P=0.06) and ejection fraction (48.0% to 56.8%, P=0.01) increased. Left ventricular end-diastolic volume (72.5 to 77.4 mL/m2, P=0.145), stroke volume (45.3 to 50.6 mL/m2, P=0.02), and ejection fraction (62.6% to 65.8%, P=0.03) increased. CONCLUSIONS: PPVI relieves RVOTO, which leads to an early improvement in biventricular performance. Furthermore, it reduces symptoms and improves exercise tolerance. These findings have important implications for the management of this increasingly common condition
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