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1.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2328-2331, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018474

RESUMEN

How do people hear sounds? As a counterpart of Prof. G. V. Békésy's traveling wave theory, we have proposed resonance theory of outer hair cells and cochlear standing wave theory, respectively. Based on these proposals, this paper develops a transmission-line-based cochlear standing wave model. Since the macroscopic cochlear model is designed as it looks like, various auditory physiology can be explained. Transient analyses with pure-tone excitation and Gaussian pulse excitation are carried out, and Prof. D. Kemp's otoacoustic emission (OAE) is demonstrated successfully.Clinical relevance-Our new model has a great potential to explain auditory physiology including structural inner disorders, hearing loss, and even tinnitus.


Asunto(s)
Cóclea , Acúfeno , Células Ciliadas Auditivas Externas , Humanos , Emisiones Otoacústicas Espontáneas , Posición de Pie
2.
Physiol Res ; 69(2): 253-260, 2020 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-32199013

RESUMEN

Beneficial effects of sesame lignans, especially antioxidative effects, have been widely reported; however, its potential effects on autonomic nerves have not yet been investigated. Therefore, the current study aimed to investigate the effect of sesame lignans on the autonomic nervous system. The sympathetic nerve activity in rat skeletal muscle was measured using electrophysiological approaches, with blood flow determined using the laser Doppler method. Sesame lignans were administered intragastrically at 2 and 20 mg/kg, and after 60 min, the sympathetic nerve activity was observed to increase by 45.2% and 66.1%, respectively. A significant increase in blood flow (39.6%) was also observed for the 20-mg/kg dose when measured at 55 min after administration. These sympathomimetic effects were completely prevented by subdiaphragmatic vagotomy, and the increase in blood flow was eliminated in the presence of the beta2-adrenergic receptor inhibitor butoxamine. Thus, it is proposed that sesame lignans can increase the blood flow of skeletal muscle, possibly by exciting sympathetic nerve activity through the afferent vagal nerve.


Asunto(s)
Velocidad del Flujo Sanguíneo/efectos de los fármacos , Lignanos/farmacología , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/efectos de los fármacos , Sesamum , Fibras Simpáticas Posganglionares/efectos de los fármacos , Animales , Velocidad del Flujo Sanguíneo/fisiología , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Lignanos/aislamiento & purificación , Masculino , Músculo Esquelético/fisiología , Ratas , Fibras Simpáticas Posganglionares/fisiología
3.
Benef Microbes ; 10(3): 293-300, 2019 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-30638397

RESUMEN

Various lactobacilli have been suggested to exert beneficial effects in humans. In this study, we examined the effects of intraduodenal (ID) administration of heat-killed Lactobacillus delbrueckii LAB4 (LAB4) on activities of efferent sympathetic nerves innervating the liver and pancreas. Consequently, it was observed that ID administration of LAB4 significantly reduced either the efferent hepatic sympathetic nerve activity (hepatic-SNA) or pancreatic sympathetic nerve activity (pancreatic-SNA) in urethane-anaesthetised rats. Moreover, the effect of acute and chronic administration of LAB4 (1×109 cells/ml) on hyperglycaemia induced by intracranial injection of 2-deoxy-D-glucose (2DG) were examined in conscious rats. We found that LAB4 significantly inhibited 2DG-induced hyperglycaemia. These findings suggest that ID administration of heat-killed LAB4 might lower plasma glucose level via changes in the autonomic nervous system in rats.


Asunto(s)
Vías Autónomas/efectos de los fármacos , Glucemia/efectos de los fármacos , Lactobacillus delbrueckii/fisiología , Hígado/inervación , Páncreas/inervación , Probióticos/farmacología , Animales , Desoxiglucosa/administración & dosificación , Desoxiglucosa/toxicidad , Modelos Animales de Enfermedad , Hiperglucemia/inducido químicamente , Hiperglucemia/tratamiento farmacológico , Masculino , Probióticos/administración & dosificación , Ratas Wistar
4.
Climacteric ; 19(6): 568-573, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27736245

RESUMEN

OBJECTIVE: Royal jelly (RJ) from honeybees (Apis mellifera) has estrogenic activity. Estrogen deficiency after menopause leads to a high risk of memory impairment and depression as well as metabolic syndrome and osteoporosis. We here investigated the effect of RJ on memory impairment and depression-like behaviors in ovariectomized (OVX) rats. METHODS: OVX rats were administered with RJ for 82 days. Hippocampus-dependent spatial memory and depression-like behaviors were assessed by the Morris water maze test and the forced swimming test, respectively. The weights of body, brain and uterus and the contents of protein and myelin galactolipids including galactosylceramide and sulfatide were measured. RESULTS: Memory impairment and depression-like behaviors in OVX rats were recovered to the levels of sham-operated rats by RJ administration. Increased body weight and decreased uterine weight in OVX rats were recovered to the levels of sham-operated rats by 17ß-estradiol (E2) administration but not by RJ administration. In contrast, brain weight was slightly increased by RJ administration but not by E2 administration. The contents of protein and myelin galactolipids were higher in the brains of RJ-administered OVX rats than in the brains of E2-administered OVX rats. CONCLUSION: The results suggest that RJ has a beneficial effect on neurological symptoms of a menopausal disorder.


Asunto(s)
Depresión/tratamiento farmacológico , Ácidos Grasos/uso terapéutico , Trastornos de la Memoria/tratamiento farmacológico , Posmenopausia/fisiología , Animales , Conducta Animal/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Estradiol/farmacología , Ácidos Grasos/administración & dosificación , Femenino , Galactolípidos/análisis , Aprendizaje por Laberinto/efectos de los fármacos , Vaina de Mielina/química , Proteínas del Tejido Nervioso/análisis , Tamaño de los Órganos/efectos de los fármacos , Ovariectomía , Ratas , Ratas Wistar , Natación , Útero/efectos de los fármacos
5.
J Appl Microbiol ; 120(6): 1711-22, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27005691

RESUMEN

AIM: To elucidate the distribution and circulation dynamics of Campylobacter and Salmonella in Japanese chicken broiler flocks. METHODS AND RESULTS: A 2-year investigation of the distribution of Campylobacter and Salmonella was conducted in 25 broiler flocks at nine farms in Japan from 2013 to 2014. Campylobacter and Salmonella tested positive in 11 (44·0%) and 24 (96·0%) broiler flocks respectively. One hundred and ninety-five Campylobacter and 184 Salmonella isolates were characterized into 12 Campylobacter (including two novel genotypes) and three Salmonella MLST genotypes. Only Salmonella isolation between caecal and environmental samples were significantly correlated. Further, one litter sample tested positive for Salmonella before new chicks were introduced. The Campylobacter strains rapidly lost culturability within 2-18 days; in contrast, the Salmonella strains survived from 64-211 days in artificially inoculated water samples. CONCLUSION: No persistent circulation-mediated Campylobacter contamination was observed. In contrast, circulation of Salmonella in broiler houses was seen, apparently due to the litter excreted from broiler flocks, as well as Salmonella-contaminated water and feed. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper provides the distribution, genotypic data and circulation dynamics of Campylobacter and Salmonella as recently observed in Japanese chicken broiler farms.


Asunto(s)
Infecciones por Campylobacter/veterinaria , Campylobacter/aislamiento & purificación , Enfermedades de las Aves de Corral/microbiología , Salmonelosis Animal/microbiología , Salmonella/aislamiento & purificación , Animales , Campylobacter/clasificación , Campylobacter/genética , Infecciones por Campylobacter/microbiología , Ciego/microbiología , Pollos , Granjas , Japón , Tipificación de Secuencias Multilocus , Prevalencia , Salmonella/clasificación , Salmonella/genética
6.
Clin Exp Allergy ; 46(9): 1152-61, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-26765219

RESUMEN

BACKGROUND: Several gene variants identified in bronchial asthmatic patients are associated with a decrease in pulmonary function. The effects of this intervention on pulmonary function have not been fully researched. OBJECTIVE: We determined the effects of high-dose inhaled corticosteroids (ICSs) on decreased pulmonary function in asthmatic Japanese patients with variants of IL13 and STAT4 during long-term treatments with low to mild doses of ICS. METHODS: In this study, 411 patients with bronchial asthma who were receiving ICSs and living in Japan were recruited, were genotyped, and underwent pulmonary function tests and fibreoptic examinations. The effects of 2 years of high-dose ICSs administered to asthmatic patients who were homozygous for IL13 AA of rs20541 or STAT4 TT of rs925847 and who progressed to airway remodelling were investigated. RESULTS: High-dose ICS treatment increased the pulmonary function of patients homozygous for IL13 AA of rs20541 but not of patients homozygous for STAT4 TT of rs925847. The increased concentrations of the mediators IL23, IL11, GMCSF, hyaluronic acid, IL24, and CCL8 in bronchial lavage fluid (BLF) were diminished after high-dose ICS treatment in patients homozygous for IL13 AA of rs20541. CONCLUSION AND CLINICAL RELEVANCE: IL13 AA of rs20541 and STAT4 TT of rs925847 are potential genomic biomarkers for predicting lower pulmonary function. The administration of high-dose ICSs to asthmatic patients with genetic variants of IL13 AA may inhibit the advancement of airway remodelling. The genetic variants of STAT4 TT did not respond to high-dose ICSs. Therefore, using medications other than ICSs must be considered even during the initial treatment of bronchial asthma. These genetic variants may aid in the realization of personalized and phenotype-specific therapies for bronchial asthma.


Asunto(s)
Remodelación de las Vías Aéreas (Respiratorias)/genética , Asma/genética , Asma/patología , Predisposición Genética a la Enfermedad , Variación Genética , Interleucina-13/genética , Factor de Transcripción STAT4/genética , Administración por Inhalación , Corticoesteroides/administración & dosificación , Remodelación de las Vías Aéreas (Respiratorias)/efectos de los fármacos , Alelos , Antiasmáticos/administración & dosificación , Asma/tratamiento farmacológico , Asma/metabolismo , Biomarcadores , Líquido del Lavado Bronquioalveolar , Citocinas/metabolismo , Eosinófilos , Femenino , Estudios de Asociación Genética , Genotipo , Humanos , Inmunoglobulina E/inmunología , Interleucina-13/metabolismo , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Pruebas de Función Respiratoria , Mucosa Respiratoria/inmunología , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/patología , Factor de Transcripción STAT4/metabolismo
7.
J Helminthol ; 90(6): 658-662, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26388560

RESUMEN

Conventional identification of Paragonimus species and their natural definitive hosts is based on the morphological features of adult parasites isolated from the lungs of wild mammalian hosts. However, wild animals are protected by strict regulations and sampling is not always possible. Recently, molecular techniques have been developed to identify the internal transcribed spacer (ITS) sequences of Paragonimus eggs in faeces/sputum of human patients. Also, mammalian hosts can be identified using the D-loop sequence of mitochondrial DNA in faecal samples. In this study, we used molecular techniques on faeces from wild animals collected in Da Krong Nature Reserve, Quang Tri province, central Vietnam, where Paragonimus metacercariae are highly prevalent in mountain crabs, to identify Paragonimus species and their natural definitive hosts. The results indicated that wild cats, Prionailurus bengalensis, were infected with at least three different Paragonimus species, P. westermani, P. skrjabini and P. heterotremus. Because all of these species can infect humans in Asian countries, human paragonimiasis should be considered in this area.


Asunto(s)
Enfermedades de los Gatos/diagnóstico , Heces/parasitología , Felidae/parasitología , Técnicas de Diagnóstico Molecular/métodos , Paragonimiasis/veterinaria , Paragonimus/aislamiento & purificación , Animales , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/parasitología , Gatos , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Variación Genética , Genotipo , Paragonimiasis/diagnóstico , Paragonimiasis/epidemiología , Paragonimiasis/parasitología , Paragonimus/clasificación , Paragonimus/genética , Vietnam/epidemiología
8.
Benef Microbes ; 6(6): 817-22, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26259890

RESUMEN

Lactobacilli exhibit several health benefits in mammals, including humans. Our previous reports established that heat-killed Lactobacillus brevis SBC8803 (SBC8803) increased both efferent gastric vagal nerve activity and afferent intestinal vagal nerve activity in rats. We speculated that this strain could be useful for the treatment of gastrointestinal (GI) disorders. In this study, we examined the effects of SBC8803 on peristalsis and the activity of the efferent celiac vagal nerve innervating the intestine in rats. First, we examined the effects of intraduodenal (ID) administration of SBC8803 on efferent celiac vagal nerve activity (efferent CVNA) in urethane-anesthetised rats using electrophysiological studies. The effects of intravenous injection of the serotonin 5-HT3 receptor antagonist granisetron on changes in efferent CVNA due to ID administration of SBC8803 were also investigated. Finally, the effects of oral gavage of SBC8803 on GI transit were analysed using the charcoal propulsion method in conscious rats treated with or without granisetron. ID administration of SBC8803 increased efferent CVNA. Pretreatment with granisetron eliminated SBC8803-dependent changes in efferent CVNA. Furthermore, oral gavage of SBC8803 significantly accelerated GI transit, while pretreatment with granisetron inhibited GI transit. Our findings suggested that SBC8803 increased efferent CVNA and GI transit of charcoal meal via 5-HT3 receptors. Moreover, SBC8803 enhanced the activity of efferent vagal nerve innervating the intestine and promoted peristalsis via 5-HT3 receptors.


Asunto(s)
Tránsito Gastrointestinal , Levilactobacillus brevis/metabolismo , Agonistas de Receptores de Serotonina , Transmisión Sináptica , Administración Oral , Animales , Fenómenos Electrofisiológicos , Calor , Masculino , Ratas Wistar , Estimulación del Nervio Vago
9.
Vet Rec ; 177(8): 202, 2015 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-26286947

RESUMEN

A coprological survey with detailed clinical observation of naturally occurring haemorrhagic enteritis (HE) cases was conducted to understand the pathophysiology of HE by clarifying the infection status of Eimeria and enteropathogenic bacteria in cattle. Faecal samples from 55 cases of HE and 26 clinically normal animals were collected, and a quantitative examination of Eimeria and potential enteropathogenic bacteria was performed. The number of Eimeria species oocysts per gram of faeces (OPG) exceeded 10,000 in 69.1 per cent of HE cases with a maximum of 1,452,500 OPG and Eimeria zuernii was found to be overwhelmingly dominant. A significant increase in faecal coliform count was observed in HE cases compared with clinically normal animals. Among the animals shedding >10,000 OPG, 42.9 per cent showed a remarkable increase in Clostridium perfringens abundance (>104 CFU/g) in the faeces. In the cases with C. perfringens detected, its abundance was positively correlated with Eimeria OPG and high C. perfringens abundance was always accompanied by high Eimeria OPG. E. zuernii is likely to play a crucial role in massive multiplication of C. perfringens in HE in cattle.

10.
J Helminthol ; 89(2): 182-8, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24229574

RESUMEN

Paragonimus heterotremus, which is an important pathogen for human paragonimiasis in Asia, is recognized as having the smallest metacercariae (maximum diameter < 300 µm) of any previously reported Paragonimus species. Recently, P. pseudoheterotremus has been described from Thailand as a new species having metacercariae (about 200 µm) slightly smaller than those of Thai P. heterotremus. In fact, the small size of P. pseudoheterotremus metacercariae is compatible with those of P. heterotremus from India and China. In this study in Vietnam, we found variably sized small metacercariae which are expected to consist of both P. heterotremus and P. pseudoheterotremus. Contrary to expectation, the adult flukes obtained by separate infection of experimental cats with different sized metacercariae were all identified as P. heterotremus, using both morphological and molecular characteristics. The molecular analyses of an extensive collection of P. heterotremus/P. pseudoheterotremus isolates from Asian countries also indicated that genetic distances between different populations of P. heterotremus are even larger than that between P. pseudoheterotremus and P. heterotremus. The haplotype network showed that all P. heterotremus and P. pseudoheterotremus isolates formed a P. heterotremus complex consisting of three groups with strong geographical origins. In addition, the Indian P. heterotremus group is the root of the other P. heterotremus and P. pseudoheterotremus populations. Based on the observed metacercarial polymorphisms and genetic variation in P. heterotremus, P. pseudoheterotremus should be considered a geographically isolated population of the P. heterotremus complex.


Asunto(s)
Braquiuros/parasitología , Variación Genética , Paragonimiasis/parasitología , Paragonimus/clasificación , Paragonimus/genética , Animales , Gatos , China , Femenino , Humanos , India , Masculino , Datos de Secuencia Molecular , Paragonimus/crecimiento & desarrollo , Paragonimus/aislamiento & purificación , Filogenia , Tailandia , Vietnam
11.
J Appl Microbiol ; 116(5): 1274-81, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24410864

RESUMEN

AIM: To evaluate the efficacy of the effects of heat-killed Lactobacillus brevis SBC8803 (HK-SBC8803) on the standard physiological markers of skin health of cutaneous arterial sympathetic nerve activity (CASNA), cutaneous blood flow and transepidermal water loss (TEWL) and to determine whether SBC8803 targets serotonin 5-HT3 receptors in rats. METHODS AND RESULTS: A set of three experiments were conducted to examine the effects of SBC8803 on CASNA, cutaneous blood flow and TEWL using Wistar and hairless rats. Two additional experiments further attempted to determine whether HK-SBC8803 was targeting the serotonin 5-HT3 receptors by pretreatment with the 5-HT3 antagonist granisetron. Administration of HK-SBC8803 in the first three experiments caused marked inhibition of CASNA and significant elevation of cutaneous blood flow under urethane anaesthesia as well as significant decrease in TEWL on the dorsal skin of conscious hairless rats. Pretreatment with granisetron decreased the effects of HK-SBC8803 on CASNA and cutaneous blood flow. CONCLUSIONS: These findings suggest that HK-SBC8803 reduces CASNA, increases cutaneous blood flow and decreases TEWL and that 5-HT3 receptors may be involved in CASNA and cutaneous blood flow responses. SIGNIFICANCE AND IMPACT OF THE STUDY: HK-SBC8803 could be a useful substance in the treatment/prevention of skin problems, specifically chapped or dry skin.


Asunto(s)
Levilactobacillus brevis , Piel/irrigación sanguínea , Sistema Nervioso Simpático/fisiología , Pérdida Insensible de Agua , Animales , Arterias/inervación , Granisetrón/farmacología , Calor , Masculino , Ratas , Ratas Wistar , Receptores de Serotonina 5-HT3 , Flujo Sanguíneo Regional , Antagonistas de la Serotonina/farmacología
12.
Phys Rev Lett ; 110(13): 131801, 2013 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-23581309

RESUMEN

We measure the branching fraction of B- → τ- ν(τ) using the full Υ(4S) data sample containing 772×10(6) BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Events with BB pairs are tagged by reconstructing one of the B mesons decaying into hadronic final states, and B- → τ- ν(τ) candidates are detected in the recoil. We find evidence for B- → τ- ν(τ) with a significance of 3.0 standard deviations including systematic errors and measure a branching fraction B(B- → τ- ν(τ))=[0.72(-0.25)(+0.27)(stat)±0.11(syst)]×10(-4).


Asunto(s)
Partículas Elementales , Física Nuclear/métodos , Teoría Cuántica
13.
J Helminthol ; 87(4): 450-6, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23067567

RESUMEN

Two members of the Paragonimus skrjabini complex, P. skrjabini and P. miyazakii, are now considered as two sub-species, P. skrjabini skrjabini and P. skrjabini miyazakii. They are well known as important pathogens for human paragonimiasis in China and Japan. Recently, members of this species complex have been reported from India. Here we report the first discovery of P. skrjabini from freshwater crab hosts in Thanh Hoa province, Vietnam. For morphological and molecular phylogenetic studies, adult worms were obtained by experimental infection in cats and dogs. Molecular analyses of metacercariae and adults revealed that the P. skrjabini population from Thanh Hoa, Vietnam was almost completely identical with that from Yunnan province, China. Those populations from Thanh Hoa, Vietnam and Yunnan, China and those from Manipur, India were significantly different from P. skrjabini populations reported from other localities of China in cytochrome oxidase subunit 1 (CO1) gene sequences, indicating considerable genetic variation within the P. skrjabini complex. Moreover, low bootstrap values in the CO1 tree suggested that more variant genotypes belonging to P. skrjabini complex may be found in other Asian countries in between Vietnam and India, such as Myanmar, Laos and Thailand. Since P. skrjabini is known as a pathogen for humans, paragonimiasis cases caused by P. skrjabini might be found in Vietnam and other Asian countries.


Asunto(s)
Braquiuros/parasitología , Paragonimus/clasificación , Paragonimus/aislamiento & purificación , Animales , Análisis por Conglomerados , ADN de Helmintos/química , ADN de Helmintos/genética , Complejo IV de Transporte de Electrones/genética , Datos de Secuencia Molecular , Paragonimus/genética , Filogenia , Análisis de Secuencia de ADN , Homología de Secuencia , Vietnam
14.
J Helminthol ; 87(2): 141-6, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22354973

RESUMEN

Among about 50 nominal Paragonimus species, Paragonimus proliferus is rather a rare species, found only in Yunnan province, China, until our recent discovery of this species in Lai Chau province, northern Vietnam close to Yunnan, China. Here we add Quang Binh province, central Vietnam as a new endemic area of P. proliferus. Large excysted metacercariae found in mountainous crabs, Potamiscus tannanti, were morphologically identified as P. proliferus, which was confirmed further by molecular analyses. Second internal transcribed spacer (ITS2) sequences of the P. proliferus population in Quang Binh province were completely (100%) identical with those of P. proliferus populations in Lai Chau province, northern Vietnam and Yunnan province, China. However, cytochrome oxidase subunit 1 (CO1) gene sequences of Quang Binh population were significantly different (5.6%) from that of previously reported northern Vietnam and Yunnan, China populations. A phylogenetic tree revealed that all CO1 sequences of P. proliferus Quang Binh population formed a distinct group, which was clustered with northern Vietnam and Yunnan, China populations with the bootstrap value of 75%. This is the first record of the genetically variant population of P. proliferus, distribution of which is geographically remote from the previously reported endemic areas in the border between northern Vietnam and Yunnan, China, suggesting that P. proliferus may be much more widely distributed in the Indochina peninsula (or South-East Asia) than expected.


Asunto(s)
Braquiuros/parasitología , Variación Genética , Paragonimus/clasificación , Paragonimus/genética , Animales , Análisis por Conglomerados , ADN de Helmintos/química , ADN de Helmintos/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Datos de Secuencia Molecular , Paragonimus/aislamiento & purificación , Filogenia , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Homología de Secuencia de Ácido Nucleico , Vietnam
15.
Phys Rev Lett ; 109(2): 021601, 2012 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-23030153

RESUMEN

We observe evidence for CP violation in the decay D+ → K(S)(0)π+ using a data sample with an integrated luminosity of 977 fb(-1) collected by the Belle detector at the KEKB e+ e- asymmetric-energy collider. The CP asymmetry in the decay is measured to be (-0.363±0.094±0.067)%, which is 3.2 standard deviations away from zero, and is consistent with the expected CP violation due to the neutral kaon in the final state.

16.
Phys Rev Lett ; 108(23): 232001, 2012 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-23003948

RESUMEN

The processes γγ → ωϕ, ϕϕ, and ωω are measured using an 870 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. Production of vector meson pairs is clearly observed and their cross sections are measured for masses that range from threshold to 4.0 GeV. In addition to signals from well established spin-zero and spin-two charmonium states, there are resonant structures below charmonium threshold, which have not been previously observed. We report a spin-parity analysis for the new structures and determine the products of the η(c), χ(c0), and χ(c2) two-photon decay widths and branching fractions to ωϕ, ϕϕ, and ωω.

17.
Phys Rev Lett ; 108(17): 171802, 2012 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-22680852

RESUMEN

We present a precise measurement of the CP violation parameter sin2φ1 and the direct CP violation parameter A(f) using the final data sample of 772×10(6) BB[over ¯] pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is reconstructed in a J/ψK(S)(0), ψ(2S)K(S)(0), χ(c1)K(S)(0), or J/ψK(L)(0) CP eigenstate and its flavor is identified from the decay products of the accompanying B meson. From the distribution of proper-time intervals between the two B decays, we obtain the following CP violation parameters: sin2φ1=0.667±0.023(stat)±0.012(syst) and A(f)=0.006±0.016(stat)±0.012(syst).

18.
Phys Rev Lett ; 108(17): 171801, 2012 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-22680851

RESUMEN

We report a measurement of the CP-violation parameter sin2φ1 at the Υ(5S) resonance using a new tagging method, called "B-π tagging." In Υ(5S) decays containing a neutral B meson, a charged B, and a charged pion, the neutral B is reconstructed in the J/ψK(S)(0) CP-eigenstate decay channel. The initial flavor of the neutral B meson at the moment of the Υ(5S) decay is opposite to that of the charged B and may thus be inferred from the charge of the pion without reconstructing the charged B. From the asymmetry between B-π(+) and B-π(-) tagged J/ψK(S)(0) yields, we determine sin2φ1=0.57±0.58(stat)±0.06(syst). The results are based on 121 fb(-1) of data recorded by the Belle detector at the KEKB e(+)e(-) collider.

19.
Phys Rev Lett ; 108(18): 181808, 2012 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-22681063

RESUMEN

We report first observations of B(s)(0) → J/ψη and B(s)(0) → J/ψη'. The results are obtained from 121.4 fb(-1) of data collected at the Υ(5S) resonance with the Belle detector at the KEKB e+ e- collider. We obtain the branching fractions B(B(s)(0) → J/ψη)=[5.10±0.50(stat)±0.25(syst)(-0.79)(+1.14)(N(B(s)(*) B(s)(*))]×10(-4), and B(B(s)(0) → J/ψη')=[3.71±0.61(stat)±0.18(syst)(-0.57)(+0.83)(N(B(s)(*) B(s)(*))]×10(-4). The ratio of the two branching fractions is measured to be (B(B(s) → J/ψη'))/(B(B(s) → J/ψη))=0.73±0.14(stat)±0.02(syst).


Asunto(s)
Partículas Elementales , Teoría Cuántica
20.
Phys Rev Lett ; 108(7): 071801, 2012 Feb 17.
Artículo en Inglés | MEDLINE | ID: mdl-22401192

RESUMEN

We search for CP violation in Cabibbo-suppressed charged D meson decays by measuring the difference between the CP-violating asymmetries for the Cabibbo-suppressed decays D(±)→K(+)K(-)π(±) and the Cabibbo-favored decays D(s)(±)→K(+)K(-)π(±) in the K(+)K(-) mass region of the ϕ resonance. Using 955 fb(-1) of data collected with the Belle detector, we obtain A(CP)(D+→ϕπ+)=(+0.51±0.28±0.05)%. The measurement improves the sensitivity of previous searches by more than a factor of 5. We find no evidence for direct CP violation.

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