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1.
Nature ; 465(7296): 326-8, 2010 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-20485430

RESUMO

The unusual helium-rich (type Ib) supernova SN 2005E is distinguished from all supernovae hitherto observed by its faint and rapidly fading light curve, prominent calcium lines in late-phase spectra and lack of any mark of recent star formation near the supernova location. These properties are claimed to be explained by a helium detonation in a thin surface layer of an accreting white dwarf. Here we report that the observed properties of SN 2005cz, which appeared in an elliptical galaxy, resemble those of SN 2005E. We argue that these properties are best explained by a core-collapse supernova at the low-mass end (8-12 solar masses) of the range of massive stars that explode. Such a low-mass progenitor lost its hydrogen-rich envelope through binary interaction, had very thin oxygen-rich and silicon-rich layers above the collapsing core, and accordingly ejected a very small amount of radioactive (56)Ni and oxygen. Although the host galaxy NGC 4589 is an elliptical, some studies have revealed evidence of recent star-formation activity, consistent with the core-collapse model.

2.
J Econ Entomol ; 109(1): 255-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26511981

RESUMO

We investigated the effects of morphology of host cucumber, Cucumis sativus L., leaves acclimatized to different atmospheric humidity levels on oviposition by adult females of the twospotted spider mite, Tetranychus urticae Koch. Cucumber seedlings were grown at a vapor pressure deficit (VPD) of 0.4, 1.9, or 3.0 kPa at 28°C (90%, 50%, or 20% relative humidity, respectively) in growth chambers until the second true leaves had expanded. Adult females of T. urticae were released on the adaxial surfaces of leaf squares cut from first and second true leaves in each treatment group, and held in the same humidity condition. Eggs were counted 2 d after release. The lower acclimatization humidity (higher VPD) increased trichome (leaf hair) density of the host leaves and oviposition rate, but the relationship between the trichome and oviposition differed between leaf positions. The leaf mass per area (LMA) was greater in first true leaves than in second true leaves, but was not influenced by VPD. A linear regression model with oviposition rate as the dependent variable and trichome density and LMA as independent variables showed that both variables influenced the oviposition rate approximately equally. We conclude that oviposition was accelerated under low humidity (high VPD) conditions indirectly probably through an increase in the trichome density of host leaves.


Assuntos
Cucumis sativus/anatomia & histologia , Oviposição , Tetranychidae/fisiologia , Aclimatação , Animais , Feminino , Umidade , Folhas de Planta/anatomia & histologia
3.
Phys Rev Lett ; 114(16): 161101, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25955041

RESUMO

We report on a new constraint on gravitylike short-range forces, in which the interaction charge is mass, obtained by measuring the angular distribution of 5 Å neutrons scattering off atomic xenon gas. Around 10^{7} scattering events were collected at the 40 m small angle neutron scattering beam line located at the HANARO research reactor of the Korean Atomic Energy Research Institute. The extracted coupling strengths of new forces in the Yukawa-type parametrization are g[over ^]^{2}=(0.2±6.8±2.0)×10^{-15} GeV^{-2} and g[over ^]^{2}=(-5.3±9.0_{-2.8}^{+2.7})×10^{-17} GeV^{-2} for interaction ranges of 0.1 and 1.0 nm, respectively. These strengths correspond to 95% confidence level limits of g^{2}<(1.4±0.2)×10^{-14} GeV^{-2} and g^{2}<(1.3±0.2)×10^{-16} GeV^{-2}, improving the current limits for interaction ranges between 4 and 0.04 nm by a factor of up to 10.

4.
Nature ; 447(7146): 829-32, 2007 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-17568740

RESUMO

The death of massive stars produces a variety of supernovae, which are linked to the structure of the exploding stars. The detection of several precursor stars of type II supernovae has been reported (see, for example, ref. 3), but we do not yet have direct information on the progenitors of the hydrogen-deficient type Ib and Ic supernovae. Here we report that the peculiar type Ib supernova SN 2006jc is spatially coincident with a bright optical transient that occurred in 2004. Spectroscopic and photometric monitoring of the supernova leads us to suggest that the progenitor was a carbon-oxygen Wolf-Rayet star embedded within a helium-rich circumstellar medium. There are different possible explanations for this pre-explosion transient. It appears similar to the giant outbursts of luminous blue variable stars (LBVs) of 60-100 solar masses, but the progenitor of SN 2006jc was helium- and hydrogen-deficient (unlike LBVs). An LBV-like outburst of a Wolf-Rayet star could be invoked, but this would be the first observational evidence of such a phenomenon. Alternatively, a massive binary system composed of an LBV that erupted in 2004, and a Wolf-Rayet star exploding as SN 2006jc, could explain the observations.

5.
Biochim Biophys Acta ; 1137(1): 39-44, 1992 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-1382608

RESUMO

Ba(2+)-currents (IBa) through voltage-dependent Ca(2+)-channels were studied in Xenopus oocytes injected with RNA from several excitable tissues, using the two-electrode voltage-clamp technique. Previous studies have shown that the expression of cardiac Ca(2+)-channels can be suppressed by an hybrid-arrest procedure that includes co-injection of the tissue-derived RNA with an 'antisense' oligonucleotide complementary to a part of RNA coding for the Ca(2+)-channel alpha 1 subunit. In this study, this method was used to investigate the role of the alpha 2/delta subunit. Co-injection of RNA extracted from either rabbit heart, rat brain or rat skeletal muscle (SkM) with 'antisense' oligonucleotides complementary to the alpha 2/delta subunit RNA did not substantially affect the expression of IBa in the oocytes. Using the Northern blot hybridization method, it was shown that native oocytes contain large amounts of alpha 2/delta subunit RNA of Ca(2+)-channel. It is proposed that te oligonucleotide treatment fails to eliminate the alpha 2/delta RNA because of the vast excess of endogenous alpha 2/delta RNA. These results impose a limit on the use of the hybrid-arrest method.


Assuntos
Canais de Cálcio/genética , Oócitos/metabolismo , RNA/genética , Animais , Bário/metabolismo , Northern Blotting , Encéfalo/metabolismo , Canais de Cálcio/metabolismo , Cátions Bivalentes , Células Cultivadas , Feminino , Hibridização de Ácido Nucleico , Oligonucleotídeos Antissenso/farmacologia , RNA/metabolismo , Coelhos , Ratos , Xenopus laevis
6.
FEBS Lett ; 297(3): 221-5, 1992 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-1371969

RESUMO

Native tissue-like L-type voltage-dependent calcium channels (L-VDCC's) were expressed by in vitro transcribed cRNA injection of rat aorta or rabbit cardiac alpha 1 subunit into Xenopus laevis oocytes. Co-injection of VSM-alpha 1 with the cloned skeletal muscle beta-subunit (SK-beta) of the L-type VDCC significantly increased the expressed peak current amplitude without significant changes in kinetics. Similar results were obtained by co-injection of cardiac alpha 1 (DSHT-alpha 1) the cloned skeletal alpha 2-subunit (SK-alpha 2) or with SK-beta. The oocytes co-expressing cRNA's retained L-type VDCC pharmacology.


Assuntos
Canais de Cálcio/metabolismo , Di-Hidropiridinas/farmacologia , Regulação da Expressão Gênica , Músculo Liso Vascular/metabolismo , Miocárdio/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Aorta , Canais de Cálcio/efeitos dos fármacos , Canais de Cálcio/fisiologia , Clonagem Molecular , Condutividade Elétrica , Feminino , Oócitos/metabolismo , Coelhos , Ratos , Xenopus laevis
7.
FEBS Lett ; 334(3): 261-4, 1993 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-8243628

RESUMO

[3H]Azidobutyryl clentiazem, a new photoactivable diltiazem derivative, has a higher binding affinity than azidobutyryl diltiazem. It can be covalently incorporated into the alpha 1 subunit of the skeletal muscle calcium channel by UV irradiation, which allows the benzothiazepine binding site to be determined. The photolabeled alpha 1 subunit and its proteolytic fragments were analyzed with a panel of sequence-directed antibodies. The results suggest that the linker region between segment S5 and S6 of domain IV is involved in benzothiazepine binding. This site is different from the dihydropyridine and verapamil binding sites.


Assuntos
Marcadores de Afinidade/metabolismo , Azidas/metabolismo , Benzodiazepinas/metabolismo , Bloqueadores dos Canais de Cálcio/metabolismo , Canais de Cálcio/metabolismo , Diltiazem/análogos & derivados , Músculos/metabolismo , Animais , Sítios de Ligação , Ligação Competitiva , Bovinos , Diltiazem/metabolismo , Testes de Precipitina , Coelhos , Verapamil/metabolismo
8.
FEBS Lett ; 331(1-2): 177-81, 1993 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-8405401

RESUMO

Calcium channel blockers are drugs that bind to the alpha 1 subunit of L-type calcium channels and selectively inhibit ion movements through these channels. Determination of the mechanism of channel blockade requires localization of drug-binding sites within the primary structure of the receptor. In this study the 1,4-dihydropyridine-binding site of the membrane bound receptor has been identified. The covalently labeled receptor was purified and digested with trypsin. The labeled peptide fragments were immunoprecipitated with sequence-directed antibodies. The data indicate the existence of at least three distinct dihydropyridine-binding domains within the primary structure of the alpha 1 subunit.


Assuntos
Canais de Cálcio/metabolismo , Di-Hidropiridinas/metabolismo , Proteínas Musculares/análise , Músculos/metabolismo , Marcadores de Afinidade , Animais , Azidas/química , Canais de Cálcio Tipo L , Di-Hidropiridinas/química , Fragmentos de Peptídeos/metabolismo , Fotoquímica , Coelhos , Trítio
9.
Biochem Pharmacol ; 56(8): 1005-12, 1998 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9776311

RESUMO

In the present study, we expressed human flavin-containing monooxygenase 1 (FMO1), FMO3, FMO4t (truncated), and FMO5 in the baculovirus expression vector system at levels of 0.6 to 2.4 nmol FMO/mg of membrane protein. These four isoforms, as well as purified rabbit FMO2, and eleven heterologously expressed human P450 isoforms were examined for their capacity to metabolize trimethylamine (TMA) to its N-oxide (TMAO), using a new, specific HPLC method with radiochemical detection. Human FMO3 was by far the most active isoform, exhibiting a turnover number of 30 nmol TMAO/nmol FMO3/min at pH 7.4 and 0.5 mM TMA. None of the other monooxygenases formed TMAO at rates greater than 1 nmol/nmol FMO/min under these conditions. Human fetal liver, adult liver, kidney and intestine microsomes were screened for TMA oxidation, and only human adult liver microsomes provided substantial TMAO-formation (range 2.9 to 9.1 nmol TMAO/mg protein/min, N = 5). Kinetic studies of TMAO formation by recombinant human FMO3, employing three different analytical methods, resulted in a Km of 28 +/- 1 microM and a Vmax of 36.3 +/- 5.7 nmol TMAO/nmol FMO3/min. The Km determined in human liver microsomes ranged from 13.0 to 54.8 microM. Therefore, at physiological pH, human FMO3 is a very specific and efficient TMA N-oxygenase, and is likely responsible for the metabolic clearance of TMA in vivo in humans. In addition, this specificity provides a good in vitro probe for the determination of FMO3-mediated activity in human tissues, by analyzing TMAO formation at pH 7.4 with TMA concentrations not higher than 0.5 mM.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Metilaminas/metabolismo , Microssomos/enzimologia , Oxidantes/metabolismo , Oxigenases/metabolismo , Cromatografia Líquida de Alta Pressão , Humanos , Intestinos/enzimologia , Rim/enzimologia , Cinética , Fígado/embriologia , Fígado/enzimologia , Microssomos Hepáticos/enzimologia
10.
Meat Sci ; 54(1): 65-70, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22063713

RESUMO

Forty-four Japanese Black fattening steers from four groups, produced in four districts and consisting of differing genetic backgrounds were slaughtered to examine the characteristic differences in muscle fiber types at the 6th thoracic vertebra of the M. longissimus thoracis (LT). The influence of percentage, diameter, and relative area of each muscle fiber type on the carcass characteristics and some quantity and quality traits of beef taken from LT, were also investigated. Significant differences in the characteristics of the muscle fiber types were observed among the four groups, except for muscle fiber diameter in the αR fiber, and the relative area of each αW fiber. For all steers, the average percentages and diameters of each muscle fiber type, ßR, αR and αW were 26.8, 18.5 and 54.7% and 51.4, 50.6 and 52.4 µm, respectively. The relative area of each fiber type was similar to those of muscle fiber composition. αR Fiber content had significant negative correlations with marbling score (p<0.05), intramuscular fat content (p<0.05) and ultimate pH value (p<0.05). Significant correlations between the diameter of each fiber type, and the quantity or quality traits of the meat were not found, with the exception of red fiber types (ßR and αR) and meat color a(∗) values (p<0.05) which were positively correlated.

11.
Jpn J Antibiot ; 43(10): 1667-73, 1990 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-2086810

RESUMO

Cefminox (CMNX), one of newly developed cephamycin antibiotics, was administered to 7 cases of diffuse peritonitis associated with infantile acute appendicitis to determine its concentrations in the blood, the appendiceal tissue and the purulent ascites and simultaneously to investigate its clinical efficacy. CMNX was intravenously injected at a dose of 20 mg/kg (at a maximum amount of 1.0 g/body) before operation and intravenously by bolus injection or by drip infusion twice daily after operation for 3 to 11 days in a total dose of 2.36 to 14.06 g. Fourteen strains of bacteria were isolated from the purulent ascites: Escherichia coli was isolated from 6 cases but superinfections in 5 cases. MICs of CMNX against these isolated organisms were at or lower than 3.13 micrograms/ml for 12 out of 14 strains. CMNX penetrated into the appendiceal tissue and the purulent ascites very well. The concentrations in the pus reached higher than those in the tissue in about 1 hour after administration and were found to reach as high as 9.63 micrograms/ml in 5 hours after administration. Its clinical efficacies were excellent in 4 cases, good in 2 cases and poor in 1 case. No subjective or objective adverse reactions were observed nor any abnormalities were found in laboratory examinations.


Assuntos
Antibacterianos/farmacocinética , Apendicite/terapia , Líquido Ascítico/metabolismo , Infecções Bacterianas , Cefamicinas/farmacocinética , Peritonite/terapia , Doença Aguda , Adolescente , Fatores Etários , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Apendicite/complicações , Apendicite/microbiologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Cefamicinas/farmacologia , Cefamicinas/uso terapêutico , Criança , Pré-Escolar , Resistência Microbiana a Medicamentos , Feminino , Humanos , Masculino , Peritonite/complicações , Peritonite/microbiologia
12.
Nihon Koshu Eisei Zasshi ; 41(11): 1090-8, 1994 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-7873769

RESUMO

Since 1983, with the institution of the "Health Service Law for the Aged", the "health notebook" has been issued to people aged 40 years and over in order to aid in management of their health. Few people actually fill their health data in notebook by themselves. In order to develop effective use of the health notebook by residents and health professionals, the uses of the health notebooks by residents aged 40 years and over, public health nurses, and physicians were investigated. Three hundred and fifty four residents aged 40 and over, 41 public health nurses, and 18 physicians were studied in 1990, in Yamagata city. A majority of residents took their health notebooks with them to health consultations, and public health nurses used the notebooks to provide advice to them. Public health nurses effectively issued the health notebooks to residents using occasions where residents gathered. Some physicians reported that health notebooks were useful for motivating the people to maintain their health, while others preferred using a health card media. When comparing the health notebooks to the maternity passbooks, health notebooks need to be more easily utilized by users for recording information, and their value should be effectively explained to them. Furthermore, in order to promote self-care behaviors, greater use of health notebooks by all health professionals in indicated.


Assuntos
Comportamentos Relacionados com a Saúde , Prontuários Médicos , Adulto , Idoso , Estudos de Avaliação como Assunto , Feminino , Promoção da Saúde , Humanos , Masculino , Pessoa de Meia-Idade
13.
Eye (Lond) ; 27(8): 931-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23743532

RESUMO

AIM: To clarify the 2-year efficacy of ranibizumab for patients with polypoidal choroidal vasculopathy (PCV) with recurrent or residual exudation from branching vascular networks after previous photodynamic therapy (PDT). METHODS: We retrospectively reviewed 26 eyes of 26 Japanese patients (22 men, 4 women) in this pilot study. All eyes had PCV with complete regression of polypoidal lesions resulting from PDT detected by indocyanine green angiography (ICGA), but recurrent or residual leakage from branching vascular networks on fluorescein angiography and evidence of persistent fluid on optical coherence tomography (OCT). Three consecutive intravitreal injections of ranibizumab (0.5 mg/0.05 ml) were administered to all eyes. RESULTS: The mean logarithm of the minimum angle of resolution best-corrected visual acuity (BCVA) improved significantly from 0.55 at baseline to 0.35 at 12 months (P<0.0001) and 0.43 at 24 months (P=0.0012). The mean increases in the BCVA 12 and 24 months after baseline were 1.95 and 1.23 lines, respectively. The mean central retinal thickness significantly decreased from 295 µm at baseline to 189 µm at 12 months (P<0.0038) and 163 µm at 24 months (P<0.001). The mean numbers of intravitreal ranibizumab (IVR) injections at months 12 and 24, including the initial treatments, were 5.8 and 8.8, respectively. Five (19.2%) eyes had recurrent polypoidal lesions on ICGA at a mean of 15.7 months after baseline. At month 24, OCT showed no exudation in 17 (65.4%) of the 26 eyes. No adverse events developed. CONCLUSIONS: IVR injections maintained or improved the VA and retinal thickness at 24 months in eyes with PCV with recurrent or residual exudation from branching vascular networks after previous PDT.


Assuntos
Inibidores da Angiogênese/administração & dosagem , Anticorpos Monoclonais Humanizados/administração & dosagem , Doenças da Coroide/tratamento farmacológico , Corioide/irrigação sanguínea , Idoso , Idoso de 80 Anos ou mais , Doenças da Coroide/fisiopatologia , Exsudatos e Transudatos , Feminino , Angiofluoresceinografia , Humanos , Verde de Indocianina , Injeções Intravítreas , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Ranibizumab , Estudos Retrospectivos , Acuidade Visual/fisiologia
15.
Neuroscience ; 171(2): 443-50, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20849933

RESUMO

Clioquinol (CQ) was associated with cases of transient global amnesia and with the neurodegenerative syndrome subacute myelo-optico-neuropathy (SMON) in humans. However, CQ forms lipophilic chelates with cations and has the potential as a scientific and clinical tool used for selective modulation of histochemically reactive zinc pools. The relationship among transient lack of synaptic zinc release, hippocampal long-term potentiation (LTP) induction and cognitive memory is poorly understood. To evaluate the role of synaptic zinc release, in the present study, hippocampal LTP induction and cognitive behavior were examined in young rats after i.p. injection of CQ (30 mg/kg). Intracellular zinc detected by Timm's stain and extracellular (synaptic cleft) zinc detected by ZnAF-2 were significantly decreased in the hippocampus 6 h after CQ injection. The molecular layer of the dentate gyrus, in which perforant path-granule cell synapses exist, was most responsive to CQ injection. Dentate gyrus LTP was induced similarly to the control 2 h after CQ injection, while significantly attenuated 6-24 h after CQ injection. In the training trial of the object recognition memory 2 h after CQ injection, there was no significant difference in learning behavior between the control and CQ-treated rats. In the test trial, CQ-treated rats showed normal recognition memory 1 h after the training, whereas recognition memory deficit 24 h after the training unlike the control rats. These results indicate that acute exposure to CQ impairs long-term (24 h) memory in the hippocampus of young rats. The CQ-mediated attenuation of dentate gyrus LTP, which may be associated with the transient lack of zinc release from zincergic neurons, seems to be involved in the impairment of the long-term memory.


Assuntos
Clioquinol/toxicidade , Hipocampo/efeitos dos fármacos , Potenciação de Longa Duração/efeitos dos fármacos , Memória/efeitos dos fármacos , Reconhecimento Psicológico/efeitos dos fármacos , Animais , Cognição/efeitos dos fármacos , Giro Denteado/efeitos dos fármacos , Giro Denteado/fisiologia , Hipocampo/fisiologia , Técnicas In Vitro , Masculino , Ratos , Zinco/fisiologia
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