RESUMO
This Letter presents the results from the MiniBooNE experiment within a full "3+1" scenario where one sterile neutrino is introduced to the three-active-neutrino picture. In addition to electron-neutrino appearance at short baselines, this scenario also allows for disappearance of the muon-neutrino and electron-neutrino fluxes in the Booster Neutrino Beam, which is shared by the MicroBooNE experiment. We present the 3+1 fit to the MiniBooNE electron-(anti)neutrino and muon-(anti)neutrino data alone and in combination with MicroBooNE electron-neutrino data. The best-fit parameters of the combined fit with the exclusive charged-current quasielastic analysis (inclusive analysis) are Δm^{2}=0.209 eV^{2}(0.033 eV^{2}), |U_{e4}|^{2}=0.016(0.500), |U_{µ4}|^{2}=0.500(0.500), and sin^{2}(2θ_{µe})=0.0316(1.0). Comparing the no-oscillation scenario to the 3+1 model, the data prefer the 3+1 model with a Δχ^{2}/d.o.f.=24.7/3(17.3/3), a 4.3σ(3.4σ) preference assuming the asymptotic approximation given by Wilks's theorem.
RESUMO
The MiniBooNE experiment at Fermilab reports results from an analysis of ν_{e} appearance data from 12.84×10^{20} protons on target in neutrino mode, an increase of approximately a factor of 2 over previously reported results. A ν_{e} charged-current quasielastic event excess of 381.2±85.2 events (4.5σ) is observed in the energy range 200
RESUMO
We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K^{+}âµ^{+}ν_{µ}) at the NuMI beamline absorber. These signal ν_{µ}-carbon events are distinguished from primarily pion decay in flight ν_{µ} and ν[over ¯]_{µ} backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=E_{ν}-E_{µ}), and total cross section for these events are extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω using neutrinos, a quantity thus far only accessible through electron scattering.
RESUMO
The MiniBooNE-DM Collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8-GeV Booster proton beam in a dedicated run with 1.86×10^{20} protons delivered to a steel beam dump. The MiniBooNE detector, 490 m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous MiniBooNE scattering results were employed, and several constraining data sets were simultaneously analyzed to minimize systematic errors from neutrino flux and interaction rates. No excess of events over background was observed, leading to a 90% confidence limit on the dark matter cross section parameter, Y=ε^{2}α_{D}(m_{χ}/m_{V})^{4}â²10^{-8}, for α_{D}=0.5 and for dark matter masses of 0.01
RESUMO
The MiniBooNE experiment at Fermilab reports results from an analysis of ν[over ¯](e) appearance data from 11.27×10(20) protons on target in the antineutrino mode, an increase of approximately a factor of 2 over the previously reported results. An event excess of 78.4±28.5 events (2.8σ) is observed in the energy range 200
RESUMO
The MiniBooNE experiment at Fermilab reports results from a search for ¯ν_{µ}â¯ν_{e} oscillations, using a data sample corresponding to 5.66×10²° protons on target. An excess of 20.9±14.0 events is observed in the energy range 475
RESUMO
Studies were carried out to elucidate the nature of biphasic ATP hydrolysis by myosin at low temperature. 1. The rate of ATP splitting decreased sharply at 3--5 min after initiation of the reaction below a critical temperature (25 degrees and 30 degrees in the presence of Ca-2+ and EDTA, respectively). On the other hand, Mg-2+-ATPase [ED 3.6.1.3] did not exhibit such biphasic kinetics. 2. The Arrhenius plot of the second phase of the reaction after the rate transition gave a straight line whether the temperature of assay was above or below the critical one, giving 5.7 kcal/mole as the activation energy of Da-2+-ATPase showed features similar to those of Ca-2+-ATPase. 3. Michaelis constants for the two phases at 8 degrees were also different. In addition, the first phase of EDTA-ATPase was shown to have two different constants, depending on ATP concentration. 4. The profiles of the dependence of ATPase activity on KCl concentration were essentially the same for both phases, while bending of the time curve was scarecly observed obove pH 8 for Ca-2+-ATPase or at pH 6 for EDTA-ATPase. 5. 2, 4-Dinitrophenol abolished the phase transition for Ca-2+-ATPase and EDTA-ATPase, and heat treatment also minimized the transition for the former.
Assuntos
Adenosina Trifosfatases/metabolismo , Miosinas/metabolismo , Trifosfato de Adenosina , Animais , Cálcio/farmacologia , Calorimetria , Dinitrofenóis/farmacologia , Ácido Edético/farmacologia , Ativação Enzimática/efeitos dos fármacos , Cinética , Magnésio/farmacologia , Músculos/enzimologia , Coelhos , Temperatura , Termodinâmica , Fatores de TempoRESUMO
As previously reported when a specific thiol group, S2, of myosin reacts with N-ethylmaleimide (NEM), its Ca2+-ATPase activity is decreased. Therefore, the reactivity of S2 can be estimated by measuring the decrement of the enzymatic activity. Using the change in the reactivity as a structural probe, we investigated whether F-actin affects the conformation around the region containing S2 under physiological conditions (at neutral pH and low ionic strength). 1. Experiments were carried out with heavy meromyosin (HMM), S1 of which had heen blocked with NEM, to observe the reactivity of S2 alone. In the experiments done in the presence of F-actin, the Ca2+-ATPase activity was measured using the heavy meromyosin fraction after actin had been removed by centrifugation and gel filtration. 2. ATP and other nucleotides activated the reactivity of S2 in the presence of Mg2+. On the other hand, F-actin markedly activated the reactivity of S2 which had been increased by ATP, but not by the other nucleotides. 3. The above cooperative action of F-actin with ATP was not observed in the presence of Ca2+ instead of Mg2+, or above 0.2 M KCl. These results suggest that the S2 region of the myosin molecule is a key region in the molecular interaction of the actin myosin-ATP system under physiological conditions.
Assuntos
Actinas , Subfragmentos de Miosina , Miosinas , Ribonucleotídeos/farmacologia , Actinas/fisiologia , Difosfato de Adenosina/farmacologia , Adenosina Trifosfatases/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Cálcio/farmacologia , Ativação Enzimática , Etilmaleimida/farmacologia , Concentração de Íons de Hidrogênio , Cinética , Subfragmentos de Miosina/metabolismo , Miosinas/metabolismo , Concentração Osmolar , Cloreto de Potássio/farmacologia , Conformação Proteica , CoelhosRESUMO
Ornithine decarboxylase (ODC) was induced by platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), and insulin at doses ranging from 0.125 to 0.5 U/mL, 25 to 500 ng/mL, and 10(-8) to 10(-7) mol/L, respectively, in NIH-3T3 cells. The induction of ODC reached a plateau approximately 4 to 6 hours after addition of each mitogen. PDGF exerted a synergistic action with 10(-7) mol/L insulin until the concentration of PDGF reached 0.5 U/mL and exerted an additive action at concentrations greater than 0.5 U/mL. FGF also accelerated ODC induction by insulin (10(-7) mol/L) synergistically when it was added at doses up to 500 ng/mL. PDGF added to the intact monolayer cells caused a spike-and-plateau increase in cytosolic Ca2+ concentration ([Ca2+]i); the spike was independent of extracellular Ca2+, whereas the plateau formation was dependent on extracellular Ca2+. On the other hand, FGF caused a plateau-like increase in [Ca2+]i, exclusively dependent on extracellular Ca2+. Insulin did not affect [Ca2+]i in NIH-3T3 cells. Trifluoperazine (15 to 30 mumol/L) inhibited the induction of ODC by PDGF and FGF, but did not inhibit the effect of insulin to induce ODC. N-(6-aminohexyl)-5-chloro-1-Naphthalenesulfonamide ([W-7] 30 to 40 mumol/L) showed a more profound suppressive effect on ODC induced by PDGF and FGF than N-(6-aminohexyl)-naphthalenesulfonamide (W-5) did. There was no difference between the effects of W-7 and W-5 on ODC induction by insulin.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Células 3T3/enzimologia , Calmodulina/fisiologia , Fator 2 de Crescimento de Fibroblastos/farmacologia , Insulina/farmacologia , Ornitina Descarboxilase/biossíntese , Fator de Crescimento Derivado de Plaquetas/farmacologia , Células 3T3/química , Animais , Cálcio/análise , Cálcio/metabolismo , Cálcio/fisiologia , Calmodulina/análise , Calmodulina/antagonistas & inibidores , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Indução Enzimática/efeitos dos fármacos , Camundongos , Ornitina Descarboxilase/fisiologia , Sulfonamidas/farmacologia , Fatores de Tempo , Trifluoperazina/farmacologiaRESUMO
The effects of 8-N-N-diethylamino octyl 3,4,5-trimethoxybenzoate (TMB-8) and trifluoperazine (TFP) on the early phase (10 min) of the release of pancreatic hormones from isolated rat islets were investigated. TMB-8 and TFP stimulated insulin, glucagon, and somatostatin release in a dose-dependent manner at a low glucose concentration (2.5 mM). The levels of glucagon and somatostatin release were also stimulated by these two agents at a high glucose concentration (10 mM). Their effects were independent of external calcium ion level. These two agents did not modify insulin release at the high glucose concentration. The stimulative effects of the two agents on the release of these hormones were partially suppressed when the islets were pretreated with 6-hydroxydopamine (6-OHDA), a chemical adrenergic denervator that acts at nerve endings. In this situation, the norepinephrine (NE) released from pancreatic islets decreased to 44% of that of non-treated islets (P less than 0.01). The addition of NE (10(-9) M) to the incubation medium increased insulin, glucagon, and somatostatin secretion by 20-30% over control levels (P less than 0.05). In conclusion, the early phase of pancreatic hormone release was stimulated by TMB-8 and TFP. Our results strongly suggest that these two drugs could be mediated by the NE released from nerve endings in the islets.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Ácido Gálico/análogos & derivados , Glucagon/metabolismo , Insulina/metabolismo , Ilhotas Pancreáticas/metabolismo , Somatostatina/metabolismo , Trifluoperazina/farmacologia , Animais , Ácido Gálico/farmacologia , Hidroxidopaminas/farmacologia , Técnicas In Vitro , Secreção de Insulina , Ilhotas Pancreáticas/efeitos dos fármacos , Cinética , Masculino , Oxidopamina , Ratos , Ratos EndogâmicosRESUMO
1) Normal intestinal microbial flora (NF) in feces of rats were examined before and after administration of gentamicin (GM). Although GM caused no influence on NF after 6 hours, the number of NF decreased markedly 24 hours after GM, viz., the count of coliforms, enterococci and lactobacilli was reduced to 1/10-1/100 of the control value while proteus and fusobacteria declines in number down to 1/100-1/1,000 times as low as the control value. 2) The decreased count of NF tended to recover to some degree at the end of the 1st therapeutic week and the considerably recovered count continued thereafter indicating about 1/10 times as low as the control value until a 12-week experimental period, except that the count of lactobacilli returned to almost normal. 3) Susceptibility of coliforms isolated from GM-treated rats to GM was nearly equal to that of the bacteria isolated from the untreated control rats, which revealed no development of drug resistance to GM. 4) The increasing rate of body weight was higher in GM-treated rats than in the control, and the feed intake was consequently great in the former.
Assuntos
Gentamicinas/farmacologia , Intestinos/microbiologia , Animais , Peso Corporal/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Resistência Microbiana a Medicamentos , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Feminino , Lactobacillus/efeitos dos fármacos , Lactobacillus/isolamento & purificação , Ratos , Staphylococcus/efeitos dos fármacos , Staphylococcus/isolamento & purificaçãoRESUMO
The effect of gentamicin (GM) on the thyroid function was investigated in relation with its stimulating action to the growth of rats at a very small dose level. The results may be summarized as follows: (1) Changes in 131-I-uptake of the thyroid after administration of GM were unremarkable. The change in wet weight of the thyroid was also unremarkable. Therefore, GM may not affect the thyroid itself. (2) GM-treated rats clearly showed a decrease in 131-I-triiodothyronine resine sponge uptake (trisorb test) as compared with the control animals, viz.,GM-treated rats indicated hypofunction of the thyroid. (3) Thyroxin (t4) levels in theserum, determined by 125-I-T4 resine sponge uptake (tetrasorb test), were apparentlylower in the GM-treated rats than in the control. (4) The thyroid function test for synthesis of the hormones revealed an increase in diiodotyrosine (DIT) value and decreases in 3, 5, 3'-triiodothyronine (T3) and T4 values in the GM-treated groups as compared with the values in the control. (5) In view of the above results iit was obvious that GM does not cause abnormalities on iodine-uptake, iodine oxidation, organic conversion to iodinated tyrosines, deiodination and thyroglobulin. In contrast, GM may induce abnormality on coupling reaction from DIT to T3 and T4 because the increase in DIT value and decreases in T3 and T4 values are seen following administration of GM. The whole of these facts seems to play an important role in stimulation to growth of rats after administration of the drug.
Assuntos
Gentamicinas/farmacologia , Glândula Tireoide/metabolismo , Glândulas Suprarrenais/anatomia & histologia , Animais , Di-Iodotirosina/metabolismo , Iodo/metabolismo , Masculino , Tamanho do Órgão , Ratos , Glândula Tireoide/anatomia & histologia , Glândula Tireoide/efeitos dos fármacos , Hormônios Tireóideos/biossíntese , Tiroxina/sangue , Tri-Iodotironina/metabolismoRESUMO
A 10-year-old girl with negative T wave in leads I, II, III, aVF, and V2-6 in the ECG was examined. The two-dimensional echocardiogram and the MRI revealed that she had a tumor in the free wall near the apex of the left ventricle. We removed the intramural fibroma (50 x 35 x 30 mm) of the left ventricle under cardiopulmonary bypass very carefully not to perforate the left ventricular cavity. After the removal, the defect was repaired by the sutures of the myocardial layers so that the volume inside the left ventricle could be kept and its shape could be maintained. She has been doing well without any trouble for 5 months after the operation.
Assuntos
Fibroma/cirurgia , Neoplasias Cardíacas/cirurgia , Procedimentos Cirúrgicos Cardíacos , Ponte Cardiopulmonar , Criança , Feminino , Ventrículos do Coração/cirurgia , HumanosRESUMO
The antitumor effect of a synthetic cord factor (6, 6'-Di-O-decanoyl-alpha, alpha-trehalose) (SS 554) on the growth of Meth-A fibrosarcoma in BALB/c mice was examined. With regard to administration routes, only intratumoral (i.t.) injection showed a curative effect; subcutaneous (s.c.), per oral (p.o.) or intravenous (i.v.) routes has no such effect. To show the antitumor effect of known natural and synthetic cord factors, the co-presence of oily vehicles has been shown to be necessary. Accordingly, compound SS 554 examined in suspensions of sesame oil, squalane (SQA), squalene (SQE) or sesame oil and water emulsion had a curative effect with a 60% survival rate. However, no such effect was obtained with a suspension in PBS or in HCO-60 solution. In this regard, it should be noted that sequential but independent administration of SS 554 and oil was found to be equally as effective as simultaneous administration of oil with SS 554. Thus the effect of the oil should be reconsidered through an examination of the sequential appearance of effector cells. In the case of sesame oil, the amount of oil necessary was over 10%, or 0.01 mg absolutely. When the dose effect of SS 554 was examined in the presence of 10% sesame oil, doses over 1 mg exhibited a dose dependent curative effect. In tumor-bearing mice, the effect of the time of administration was also examined; the best result was obtained when intratumor injection was performed on day 3 after tumor implantation. Mice that recovered after SS 554 treatment exhibited growth inhibition and rejection of rechallenged Meth-A cells. However, this immunity was specific as it did not extend to a rechallenge with RL male-1 leukemia cells.