Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Lett Math Phys ; 113(1): 25, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36845409

RESUMO

An extension of the notion of classical equivalence of equivalence in the Batalin-Vilkovisky (BV) and Batalin-Fradkin-Vilkovisky (BFV) frameworks for local Lagrangian field theory on manifolds possibly with boundary is discussed. Equivalence is phrased in both a strict and a lax sense, distinguished by the compatibility between the BV data for a field theory and its boundary BFV data, necessary for quantisation. In this context, the first- and second-order formulations of nonabelian Yang-Mills and of classical mechanics on curved backgrounds, all of which admit a strict BV-BFV description, are shown to be pairwise equivalent as strict BV-BFV theories. This in particular implies that their BV complexes are quasi-isomorphic. Furthermore, Jacobi theory and one-dimensional gravity coupled with scalar matter are compared as classically equivalent reparametrisation-invariant versions of classical mechanics, but such that only the latter admits a strict BV-BFV formulation. They are shown to be equivalent as lax BV-BFV theories and to have isomorphic BV cohomologies. This shows that strict BV-BFV equivalence is a strictly finer notion of equivalence of theories.

2.
Neuroscience ; 271: 160-9, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24797328

RESUMO

Brain ischemic tolerance is an endogenous protective mechanism activated by a preconditioning stimulus that is closely related to N-methyl-d-aspartate receptor (NMDAR). Glycine transporter type 1 (GlyT-1) inhibitors potentiate NMDAR and suggest an alternative strategy for brain preconditioning. The aim of this work was to evaluate the effects of brain preconditioning induced by sarcosine, a GlyT-1 inhibitor, against global cerebral ischemia and its relation to NMDAR. Sarcosine was administered over 7 days (300 or 500 mg/kg/day, ip) before the induction of a global cerebral ischemia model in Wistar rats (male, 8-week-old). It was observed that sarcosine preconditioning reduced cell death in rat hippocampi submitted to cerebral ischemia. Hippocampal levels of glycine were decreased in sarcosine-treated animals, which was associated with a reduction of [(3)H] glycine uptake and a decrease in glycine transporter expression (GlyT-1 and GlyT-2). The expression of glycine receptors and the NR1 and NR2A subunits of NMDAR were not affected by sarcosine preconditioning. However, sarcosine preconditioning reduced the expression of the NR2B subunits of NMDAR. In conclusion, these data demonstrate that sarcosine preconditioning induces ischemic tolerance against global cerebral ischemia and this neuroprotective state is associated with changes in glycine transport and reduction of NR2B-containing NMDAR expression.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Glicina/metabolismo , Hipocampo/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Sarcosina/farmacologia , Animais , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Glicina/antagonistas & inibidores , Proteínas da Membrana Plasmática de Transporte de Glicina/metabolismo , Hipocampo/patologia , Hipocampo/fisiopatologia , Masculino , Neurônios/efeitos dos fármacos , Neurônios/patologia , Neurônios/fisiologia , Ratos Wistar
3.
Brain Res ; 1486: 53-61, 2012 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-23022567

RESUMO

Stroke is a leading cause of morbidity and mortality worldwide. Recovery of motor function after stroke can be modified by post-injury experience, but most of surviving patients exhibit persistence of the motor dysfunctions even after rehabilitative therapy. In this study we investigated if skilled and unskilled training induce different motor recovery and brain plasticity after experimental focal ischemia. We tested this hypothesis by evaluating the motor skill relearning and the immunocontent of Synapsin-I, PSD-95 and GFAP (pre and post-synaptic elements, as well as surrounding astroglia) in sensorimotor cortex of both hemispheres 6 weeks after endothelin-1-induced focal brain ischemia in rats. Synapsin-I and PSD-95 levels were increased by skilled training in ischemic sensorimotor cortex. The content of GFAP was augmented as a result of focal brain ischemia in ischemic sensorimotor cortex and that was not modified by rehabilitation training. Unexpectedly, animals remained permanently impaired at the end of motor/functional evaluations. Significant modifications in protein expression were not observed in undamaged sensorimotor cortex. We conclude that skilled motor activity can positively affect brain plasticity after focal ischemia despite of no functional improvement in conditions here tested.


Assuntos
Isquemia Encefálica/reabilitação , Aprendizagem/fisiologia , Córtex Motor/fisiologia , Destreza Motora/fisiologia , Plasticidade Neuronal/fisiologia , Recuperação de Função Fisiológica/fisiologia , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/fisiopatologia , Masculino , Córtex Motor/metabolismo , Desempenho Psicomotor/fisiologia , Ratos , Ratos Wistar , Sinapsinas/biossíntese , Sinapsinas/fisiologia
4.
Phys Rev Lett ; 87(16): 162001, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11690200

RESUMO

We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

5.
Phys Rev Lett ; 86(14): 2955-8, 2001 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-11290081

RESUMO

Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay D0-->K+pi- with a signal yield of 149+/-31 events compared to a similarly cut sample consisting of 36 760+/-195 D0-->K-pi+ events. We use the observed ratio of D0-->K+pi- to D0-->K-pi+ (0.404+/-0.085+/-0.025)% to obtain a relationship between the D0 mixing and doubly Cabibbo suppressed decay parameters.

6.
J Digit Imaging ; 10(3 Suppl 1): 109-12, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9268853

RESUMO

One of the major service issues within Medical Imaging is delivering reports quickly to referring physicians. As an effort to improve service, Mount Sinai Hospital's Department of Medical Imaging implemented Auto-Fax to distribute imaging reports to physicians instead of the postal service. When a report is transcribed and then verified by the dictating radiologist, the radiology information system will automatically fax the result report to the referring physicians if subscribed to the Auto-Fax service. If not, the report will be printed and mailed out manually. A transmission log is kept recording the requisition number, time, date, fax number, number of pages, and transmission status of all reports faxed. The system will try three times to fax the report. If unsuccessful at all attempts, the report will be printed and sent out by mail. Referring physicians are required to sign an agreement that the receiving parties are responsible to ensure transmitted reports are kept confidential. Over 150 referring physicians have signed on for the service. Initial problems with missing cover pages, missing report pages, and reports not being received by physicians have been resolved. A recent survey of physicians receiving reports by Auto-Fax indicate that the service is very popular and has increased the speed with which transcribed report are received. Suggestions for improvement included faxing reports in batches, at specific times of the day, and directly to personal computers. Challenges reported included photocopying thermal paper faxes and sorting reports (for those offices with shared fax machines).


Assuntos
Diagnóstico por Imagem , Sistemas de Informação em Radiologia , Encaminhamento e Consulta , Telefac-Símile , Humanos , Serviço Hospitalar de Radiologia
7.
Trans R Soc Trop Med Hyg ; 87(3): 299-302, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8236398

RESUMO

To compare the efficacy and side effects of intramuscular (i.m.) and intravenous (i.v.) quinine, children in Mozambique with severe and complicated malaria between 6 months and 7 years were randomized to treatment with i.m. or i.v. quinine, both in a dosage of quinine dihydrochloride 20 mg/kg followed by 10 mg/kg every 8 h. Of 57 children treated with i.m. quinine, 4 died, 3 had neurological sequelae and 2 had sterile intramuscular abscesses. Of 47 children treated with i.v. quinine, 6 died and 1 had neurological sequelae. The mean parasite clearance time was 58.6 h in the i.m. group and 59.3 h in the i.v. group. Mean temperature clearance times were 56.1 and 51.8 h, and mean coma clearance times 40.4 and 38.7 h, respectively. None of these differences was statistically significant. Mean trough and peak concentrations of quinine were almost identical in the 2 groups, ranging from 10.5 to 12.6 mg/L, which is in the therapeutic non-toxic range. It is concluded that i.m. quinine is as effective as quinine by i.v. infusion in children with severe and complicated malaria; that minor local side effects can probably be avoided by using diluted quinine for i.m. injection; and that the optimal dose regimen for children with severe and complicated malaria in Africa at present is probably quinine salt 20 mg/kg followed by 10 mg/kg every 12 h.


Assuntos
Malária Cerebral/tratamento farmacológico , Malária Falciparum/tratamento farmacológico , Quinina/administração & dosagem , Criança , Pré-Escolar , Relação Dose-Resposta a Droga , Feminino , Humanos , Lactente , Infusões Intravenosas , Injeções Intramusculares , Malária Cerebral/mortalidade , Malária Falciparum/mortalidade , Masculino , Prognóstico , Quinina/efeitos adversos
8.
Trans R Soc Trop Med Hyg ; 85(3): 341-4, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1949135

RESUMO

The efficacy of intramuscular (i.m.) sulfadoxine-pyrimethamine (sulfadoxine 25 mg/kg plus pyrimethamine 1.25 mg/kg in a single dose; n = 48) was compared with that of i.m. quinine (10 mg/kg 8-hourly for at least 3 d followed by oral quinine to complete 7 d; n = 54) in children with severe malaria without life-threatening complications in Maputo Central Hospital, Mozambique, in 1989. Mean parasite clearance time and mean fever clearance time were 55.4 h and 48.1 h, respectively, in the sulfadozine-pyrimethamine group, and 60.7 h and 54 h in the quinine group. Seven cases in the sulfadoxine-pyrimethamine group were RII/RIII resistant compared with none in the quinine group, but parasite reduction during the first 48 h was no slower in the resistant cases than in the 7 poorest responders to quinine. Blood sugar levels were slightly, but not significantly, lower in the quinine group. On day 7, leucocyte counts were significantly lower in the sulfadoxine-pyrimethamine group, but within the normal range. It is concluded that a single dose of sulfadoxine-pyrimethamine may be useful for the treatment of complicated malaria at health care units without facilities for admission, or if transferral is necessary after start of treatment.


Assuntos
Malária Falciparum/tratamento farmacológico , Pirimetamina/uso terapêutico , Quinina/uso terapêutico , Sulfadoxina/uso terapêutico , Animais , Criança , Pré-Escolar , Quimioterapia Combinada , Humanos , Lactente , Injeções Intramusculares , Contagem de Leucócitos , Malária Falciparum/sangue , Plasmodium falciparum/efeitos dos fármacos , Pirimetamina/administração & dosagem , Quinina/administração & dosagem , Sulfadoxina/administração & dosagem
9.
Ars cvrandi cardiol ; 7(54): 30, 32, 34-8 passim, set. 1985. tab
Artigo em Português | LILACS | ID: lil-31120

RESUMO

É relatada a mortalidade cirúrgica na revascularizaçäo do miocárdio em diferentes etapas, entre outubro de 1972 e dezembro de 1984. A partir de 1980 esteve sempre igual ou inferior a 3%, sendo que em um dos Serviços chegou a 0,9% em 1983 e 1984. Säo analisados os fatores incrementadores do risco cirúrgico nesta experiência


Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Revascularização Miocárdica/mortalidade
11.
Arq. bras. cardiol ; 40(1): 29-31, 1983. ilus, tab
Artigo em Português | LILACS | ID: lil-13939

RESUMO

Numerosas tecnicas sao empregadas para perfundir a parte inferior do corpo durante a resseccao de aneurisma da aorta toracica descendente. Nenhuma delas e isenta de complicacoes. Cinco casos deste tipo de aneurisma foram tratados pela tecnica de Crawford, com o pincamento puro e simples da aorta descendente. As possiveis vantagens da tecnica sao discutidas


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Vasculares , Aneurisma Aórtico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...