215 research outputs found
Clinical features of cats with aqueous tear deficiency: a retrospective case series of 10 patients (17 eyes)
Objectives
The aim of this study was to describe the clinical findings, diagnostic test results and response to therapy of cats with Schirmer tear test 1 (STT-1) values below the reference interval.
Methods
The medical records of three institutions were searched for cats with ocular surface disease and STT-1 values/min, confirmed at two or more separate visits.
Results
Ten cats (17 eyes) were included. The mean ± SD (range) age and STT-1 values in affected eye(s) were 6.1 ± 5.7 (0.2–16) years and 2.4 ± 3.1 (0–8) mm/min, respectively. Concurrent ocular surface disease was bilateral in 5/10 cats. Clinical signs included conjunctivitis (14/17 eyes), corneal ulceration (6/17 eyes), non-ulcerative keratitis (4/17 eyes), symblepharon (4/17 eyes), eosinophilic keratitis (3/17 eyes), corneal sequestrum (3/17 eyes), corneal fibrosis (2/17 eyes) and meibomitis (2/17 eyes). Management included topically applied lacrimomimetics, antiviral drugs, corticosteroids or immunomodulatory drugs; orally administered famciclovir; or surgical procedures, in various combinations. Response to therapy (defined as an increase in STT-1 value of ⩾5 mm/min) was transient (seen at a single reassessment) in 65% of eyes and sustained (seen at ⩾2 consecutive reassessments) in 18% of eyes.
Conclusions and relevance
Clinical features seen in cats with low STT-1 values are described, although the association between aqueous deficiency and the reported ocular changes is unknown at this time. We encourage clinicians to assess the tear film in cats with ocular surface disease, and initiate therapy with lacrimomimetics if STT-1 values are repeatedly below normal. Such information will further define aqueous tear deficiency in cats, providing a better understanding of disease prevalence, pathogenesis and treatment
Pharmacokinetics of intramuscular maropitant in pigs (Sus scrofa domesticus)
Pigs are at risk of vomiting from medical conditions as well as the emetic side effects of drugs administered for peri-operative manipulations, but there is a lack of pharmacokinetic data for potential anti-emetic therapies, such as maropitant, in this species. The main objective of this study was to estimate plasma pharmacokinetic parameters for maropitant in pigs after a single intramuscular (IM) administration dosed at 1.0 mg/ kg. A secondary objective was to estimate pilot pharmacokinetic parameters in pigs after oral (PO) administration at 2.0 mg/kg. Maropitant was administered to six commercial pigs at a dose of 1.0 mg/kg IM. Plasma samples were collected over 72 h. After a 7-day washout period, two pigs were administered maropitant at a dose of 2.0 mg/ kg PO. Maropitant concentrations were measured via liquid chromatography/mass spectrometry (LC–MS/ MS). A non-compartmental analysis was used to derive pharmacokinetics parameters. No adverse events were noted in any of the study pigs after administration. Following single IM administration, maximum plasma concentration was estimated at 412.7 ± 132.0 ng/mL and time to maximum concentration ranged from 0.083 to 1.0 h. Elimination half-life was estimated at 6.7 ± 1.28 h, and mean residence time was 6.1 ± 1.2 h. Volume of distribution after IM administration was 15.9 L/ kg. Area under the curve was 1336 ± 132.0 h*ng/mL. The relative bioavailability of PO administration was noted to be 15.5% and 27.2% in the two pilot pigs. The maximum systemic concentration observed in the study pigs after IM administration was higher than what was observed after subcutaneous administration in dogs, cats, or rabbits. The achieved maximum concentration exceeded the concentrations for anti-emetic purposes in dogs and cats; however, a specific anti-emetic concentration is currently not known for pigs. Further research is needed into the pharmacodynam
Onset of Superfluidity in 4He Films Adsorbed on Disordered Substrates
We have studied 4He films adsorbed in two porous glasses, aerogel and Vycor,
using high precision torsional oscillator and DC calorimetry techniques. Our
investigation focused on the onset of superfluidity at low temperatures as the
4He coverage is increased. Torsional oscillator measurements of the 4He-aerogel
system were used to determine the superfluid density of films with transition
temperatures as low as 20 mK. Heat capacity measurements of the 4He-Vycor
system probed the excitation spectrum of both non-superfluid and superfluid
films for temperatures down to 10 mK. Both sets of measurements suggest that
the critical coverage for the onset of superfluidity corresponds to a mobility
edge in the chemical potential, so that the onset transition is the bosonic
analog of a superconductor-insulator transition. The superfluid density
measurements, however, are not in agreement with the scaling theory of an onset
transition from a gapless, Bose glass phase to a superfluid. The heat capacity
measurements show that the non-superfluid phase is better characterized as an
insulator with a gap.Comment: 15 pages (RevTex), 21 figures (postscript
Opportunities for mesoscopics in thermometry and refrigeration: Physics and applications
This review presents an overview of the thermal properties of mesoscopic
structures. The discussion is based on the concept of electron energy
distribution, and, in particular, on controlling and probing it. The
temperature of an electron gas is determined by this distribution:
refrigeration is equivalent to narrowing it, and thermometry is probing its
convolution with a function characterizing the measuring device. Temperature
exists, strictly speaking, only in quasiequilibrium in which the distribution
follows the Fermi-Dirac form. Interesting nonequilibrium deviations can occur
due to slow relaxation rates of the electrons, e.g., among themselves or with
lattice phonons. Observation and applications of nonequilibrium phenomena are
also discussed. The focus in this paper is at low temperatures, primarily below
4 K, where physical phenomena on mesoscopic scales and hybrid combinations of
various types of materials, e.g., superconductors, normal metals, insulators,
and doped semiconductors, open up a rich variety of device concepts. This
review starts with an introduction to theoretical concepts and experimental
results on thermal properties of mesoscopic structures. Then thermometry and
refrigeration are examined with an emphasis on experiments. An immediate
application of solid-state refrigeration and thermometry is in ultrasensitive
radiation detection, which is discussed in depth. This review concludes with a
summary of pertinent fabrication methods of presented devices.Comment: Close to the version published in RMP; 59 pages, 35 figure
A study of molecular changes relating to energy metabolism and cellular stress in people with Huntington’s disease: looking for biomarkers
Considerações sobre a produção de leite a pasto.
A alternativa racional para melhoria na competitividade e sustentabilidade da produção de leite no Brasil, é a saída do sistema estabulado de gado puro ou de elevada mestiçagem da raça holandesa para o sistema de produção intensiva em pastagens de alto valor nutritivo e alta produtividade. As pastagens representam a fonte mais econômica para alimentação dos rebanhos e a produção de leite a pasto é o sistema mais econômico. Além do aspecto econômico, a utilização mais racional das pastagens auxilia na preservação dos recursos renováveis e permite a produção de leite sob condições mais naturais. Em explorações bem manejadas, com forrageiras de alto valor nutritivo e produtivo, o retorno por vaca em lactação supera em 30% em comparação com o sistema de alimentação no cocho
Composição bromatológica da digitaria e do Tangola, sob diferentes lâminas de irrigação e adubação nitrogenada.
Objetivando avaliar o efeito de diferentes níveis de irrigação e de adubação nitrogenada sobre o teor de fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e teor de proteína bruta (PB) dos capins Tangola (Brachiaria spp.) e Digitaria (Digitaria sp), foi conduzido um experimento na Embrapa Meio-Norte, em Parnaíba, Pi. O delineamento experimental foi de blocos casualizados, em esquema fatorial 2 x 3 x 4, com três repetições; sendo duas gramíneas, três níveis de irrigação (80%, 50% e 20% da evaporação do Tanque Classe A) e quatro níveis de nitrogênio (100; 250; 400 e 550 kg ha/ano). As adubações nitrogenadas foram fracionadas e aplicadas, na forma de uréia e em cobertura, após cada um dos quatro cortes realizados no período. A Digitaria sp apresentou maiores teores de FDN em relação ao Tangola em todos os níveis de adubação nitrogenada e no maior nível de irrigação aplicada. Com relação ao teor de FDA a Digitaria foi inferior ao Tangola apenas no nível intermediário de irrigação e no maior nível de adubação nitrogenada. A adubação nitrogenada afetou positivamente o teor de proteína bruta de ambas as gramíneas
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