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1.
Phys Rev Lett ; 132(21): 211803, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38856264

RESUMO

We report the first search for dark sectors performed at the NA64 experiment employing a high energy muon beam and a missing energy-momentum technique. Muons from the M2 beamline at the CERN Super Proton Synchrotron with a momentum of 160 GeV/c are directed to an active target. The signal signature consists of a single scattered muon with momentum <80 GeV/c in the final state, accompanied by missing energy, i.e., no detectable activity in the downstream calorimeters. For a total dataset of (1.98±0.02)×10^{10} muons on target, no event is observed in the expected signal region. This allows us to set new limits on the remaining (m_{Z^{'}},g_{Z^{'}}) parameter space of a new Z^{'} (L_{µ}-L_{τ}) vector boson which could explain the muon (g-2)_{µ} anomaly. Additionally, our study excludes part of the parameter space suggested by the thermal dark matter relic abundance. Our results pave the way to explore dark sectors and light dark matter with muon beams in a unique and complementary way to other experiments.

2.
Phys Rev Lett ; 131(16): 161801, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37925688

RESUMO

Thermal dark matter models with particle χ masses below the electroweak scale can provide an explanation for the observed relic dark matter density. This would imply the existence of a new feeble interaction between the dark and ordinary matter. We report on a new search for the sub-GeV χ production through the interaction mediated by a new vector boson, called the dark photon A^{'}, in collisions of 100 GeV electrons with the active target of the NA64 experiment at the CERN SPS. With 9.37×10^{11} electrons on target collected during 2016-2022 runs NA64 probes for the first time the well-motivated region of parameter space of benchmark thermal scalar and fermionic dark matter models. No evidence for dark matter production has been found. This allows us to set the most sensitive limits on the A^{'} couplings to photons for masses m_{A^{'}}≲0.35 GeV, and to exclude scalar and Majorana dark matter with the χ-A^{'} coupling α_{D}≤0.1 for masses 0.001≲m_{χ}≲0.1 GeV and 3m_{χ}≤m_{A^{'}}.

3.
Phys Rev Lett ; 129(16): 161801, 2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36306760

RESUMO

A search for a new Z^{'} gauge boson associated with (un)broken B-L symmetry in the keV-GeV mass range is carried out for the first time using the missing-energy technique in the NA64 experiment at the CERN SPS. From the analysis of the data with 3.22×10^{11} electrons on target collected during 2016-2021 runs, no signal events were found. This allows us to derive new constraints on the Z^{'}-e coupling strength, which, for the mass range 0.3≲m_{Z^{'}}≲100 MeV, are more stringent compared to those obtained from the neutrino-electron scattering data.

4.
Phys Rev Lett ; 126(21): 211802, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34114842

RESUMO

We performed a search for a new generic X boson, which could be a scalar (S), pseudoscalar (P), vector (V), or an axial vector (A) particle produced in the 100 GeV electron scattering off nuclei, e^{-}Z→e^{-}ZX, followed by its invisible decay in the NA64 experiment at CERN. No evidence for such a process was found in the full NA64 dataset of 2.84×10^{11} electrons on target. We place new bounds on the S, P, V, A coupling strengths to electrons, and set constraints on their contributions to the electron anomalous magnetic moment a_{e}, |Δa_{X}|≲10^{-15}-10^{-13} for the X mass region 1 MeV≲m_{X}≲1 GeV. These results are an order of magnitude more sensitive compared to the current accuracy on a_{e} from the electron g-2 experiments and recent high-precision determination of the fine structure constant.

5.
Phys Rev Lett ; 125(8): 081801, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32909809

RESUMO

We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as a shield, and would be observed either through their a(s)→γγ decay in the rest of the HCAL detector, or as events with a large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing of the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84×10^{11} electrons on target, allowing us to set new limits on the a(s)γγ-coupling strength for a(s) masses below 55 MeV.

6.
Phys Rev Lett ; 123(12): 121801, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31633975

RESUMO

A search for sub-GeV dark matter production mediated by a new vector boson A^{'}, called a dark photon, is performed by the NA64 experiment in missing energy events from 100 GeV electron interactions in an active beam dump at the CERN SPS. From the analysis of the data collected in the years 2016, 2017, and 2018 with 2.84×10^{11} electrons on target no evidence of such a process has been found. The most stringent constraints on the A^{'} mixing strength with photons and the parameter space for the scalar and fermionic dark matter in the mass range ≲0.2 GeV are derived, thus demonstrating the power of the active beam dump approach for the dark matter search.

7.
J Helminthol ; 94: e71, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31409433

RESUMO

Human ascariasis is a neglected tropical disease of great relevance to public health and is considered the most frequent helminthiasis in poor regions. Accurately diagnosing this parasite has been challenging due to limitations of current diagnostic methods. Immunoglobulin Y (IgY) technology is a very effective alternative for the production of highly specific and profitable antibodies. This study aimed to produce and apply anti-Ascaris suum IgY antibodies in the immunodiagnosis of human ascariasis. Five immunizations comprising total saline extract from A. suum adult life forms were given at 14-day intervals to Gallus gallus domesticus hens of the Isa Brown line. Eggs and blood samples were collected weekly and fortnightly, respectively, to monitor the production of antibodies. The specificity of antibodies was confirmed by dot-blot, kinetic enzyme-linked immunosorbent assay (ELISA), avidity ELISA, immunoblotting and indirect immunofluorescence antibody tests. The application for disease diagnosis was performed through the detection of immune complexes in human serum samples by sandwich ELISA. Peaks of IgY anti-A. suum production occurred at weeks 6 and 8. IgY showed high avidity levels after the second dose of immunization, ranging from 64% to 93%, with a mean avidity index of 78.30%. Purified IgY recognized 12 bands of proteins from A. suum saline extract. Eggs, the uterine portion and cuticles of A. suum female adult are reactive in immunofluorescence. The detection of immune complexes showed diagnostic values of 80% sensitivity and 90% specificity. In conclusion, specific IgY have been shown to be a potential immunodiagnostic tool with promising future applications in human ascariasis.


Assuntos
Anticorpos Anti-Helmínticos/biossíntese , Ascaríase/diagnóstico , Ensaio de Imunoadsorção Enzimática , Imunoglobulinas/biossíntese , Animais , Complexo Antígeno-Anticorpo , Antígenos de Helmintos/administração & dosagem , Antígenos de Helmintos/imunologia , Ascaris suum , Galinhas , Feminino , Humanos , Imunização , Testes Imunológicos/métodos , Sensibilidade e Especificidade
8.
Clin Genet ; 92(2): 199-203, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28116794

RESUMO

Different types of mutations in the DMD gene underlie Duchenne muscular dystrophies (DMD) and Becker muscular dystrophies (BMD). Large deletions and duplications are the most frequent causative genetic alterations worldwide, but little is known about DMD/BMD genetic profile in Brazil. Hence, we recruited patients with DMD and BMD from 8 neuromuscular reference centers along the country, and performed a comprehensive molecular investigation that included Multiplex Ligation-dependent Probe Amplification and Next generation sequencing (NGS) analyses. We evaluated 199 patients from 177 unrelated families: 166 with DMD, 32 with BMD and 1 1.5 years old asymptomatic patient with persistent hiperCKemia. Overall, large deletions (58.2%) followed by nonsense mutations (12.4%) and large duplications (11.3%) were the most frequent variants in Brazilian families. Large deletions were less frequent in BMD than in DMD (44.8% vs 60.8%). We identified 19 new DMD variants. Nonsense mutations were significantly more frequent in patients from northeastern region than from southern/southeastern regions of Brazil (27.7% vs 8.5%, P < .05). Genetic profile of Brazilian patients with DMD/BMD is similar to previously reported cohorts, but it is not uniform across the country. This information is important to plan rational clinical care for patients in face of the new coming mutation-specific therapies.


Assuntos
Distrofina/genética , Predisposição Genética para Doença , Distrofia Muscular de Duchenne/diagnóstico , Distrofia Muscular de Duchenne/genética , Adolescente , Brasil , Criança , Pré-Escolar , Análise Mutacional de DNA , Diagnóstico Diferencial , Éxons/genética , Feminino , Duplicação Gênica/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Distrofia Muscular de Duchenne/epidemiologia , Distrofia Muscular de Duchenne/fisiopatologia , Mutação , Deleção de Sequência , Adulto Jovem
9.
Spinal Cord ; 54(10): 861-865, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26927294

RESUMO

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The main goal of this study was to examine the influence of regular physical activity (PA) on lung volumes and flows. SETTING: The study was conducted in the Vall d'Hebrón Hospital, Barcelona (Spain), and La Fe Hospital, Valencia (Spain). METHODS: Spirometric tests were performed to 67 paraplegics, and differences were established between the active group (AG) (n=37) that performed >60 min per week of moderate-to-vigorous PA (MVPA) and 30 non-AG (NAG). Further, we established the relationship between the spirometric and PA variables and between being active and reaching the lower limit of normal (LLN) of the spirometric variables. RESULTS: AG had greater values than the NAG: FVC (P<0.01), FEV1 (P<0.01) and PEF (P<0.01). Moderate correlations between the MVPA and FVC (r=0.41, P<0.01) and the MVPA and FEV1 (r=0.39, P<0.01) were obtained. The relationship between being physically active and reaching the LLN was statistically significant for FEV1 (χ2=6.184, P<0.05) but not for FVC (P>0.05). CONCLUSIONS: The performance of MVPA for a minimum of 60 min per week can have a beneficial effect, both on lung volumes and on expiratory flow, and led to an achievement of the LLN in FEV1.


Assuntos
Exercício Físico/fisiologia , Pneumopatias/etiologia , Paraplegia/complicações , Adulto , Distribuição de Qui-Quadrado , Estudos Transversais , Feminino , Volume Expiratório Forçado/fisiologia , Humanos , Pneumopatias/diagnóstico , Masculino , Pessoa de Meia-Idade , Espanha , Espirometria , Capacidade Vital
10.
J Fish Biol ; 89(1): 876-89, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27264779

RESUMO

In this study, seasonal numerical abundance of the critically endangered Atlantic goliath grouper Epinephelus itajara was estimated by conducting scuba dive surveys and calculating sightings-per-unit-effort (SPUE) at three sites in southern Brazil. Seasonal differences in size and reproductive condition of captured or confiscated specimens were compared. The SPUE differed significantly with season, increasing in late spring and peaking during the austral summer months. A significant effect was observed in the number of fish relative to the lunar cycle. All females sampled during the summer were spawning capable, while all those sampled during other seasons were either regressing or regenerating. What these data strongly infer is that the E. itajara spawning aggregation sites have been located in the southern state of Paraná and the northern state of Santa Catarina and summer is the most likely spawning season. Size frequency distributions, abundance and reproductive state were estimated and correlated with environmental variables.


Assuntos
Bass/fisiologia , Reprodução , Comportamento Social , Animais , Bass/anatomia & histologia , Brasil , Feminino , Masculino , Lua , Ovário/anatomia & histologia , Estações do Ano
11.
Spinal Cord ; 53(1): 59-63, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25403502

RESUMO

STUDY DESIGN: Cross-sectional study. OBJECTIVES: The main goal of our study was to explore the differences in heart rate variability (HRV) while sitting between able-bodied (AB) participants and paraplegic (P) individuals. SETTING: The study was conducted in the Physical Therapy department and the Physical Education and Sports department of the University of Valencia and Vall d'Hebrón Hospital. METHODS: To record the HRV, a 1000-Hz Suunto Oy t6 heart rate monitor was used. The data were analyzed in the temporal and frequency domains, and nonlinear analysis was performed as well. RESULTS: We found significant differences between P and AB participants in SDNN: t(76)=2.81, P<0.01; root mean squared of the difference of successive RR intervals: t(76)=2.35, P<0.05; very low frequency: t(76)=2.97, P<0.01; low frequency: t(41.06)=2.33, P<0.05; total power of the spectrum: t(45.74)=2.57, P<0.05; SD1: t(76)=2.35, P<0.05; SD2: t(76)=2.82, P<0.01. Furthermore, there is a reduced variability in the P participants who adopted a sedentary lifestyle as could be observed in detrended fluctuation1 t(40)=-2.10; P<0.05. CONCLUSION: Although individuals in the P group were more active in sports than the AB group, they had an altered HRV when compared with AB individuals. It could be important to develop more intense sports programs to improve cardiac vagal tone, which in turn produces a decrease in work and oxygen consumption of the heart.


Assuntos
Frequência Cardíaca/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Adulto , Estudos Transversais , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-Idade , Paraplegia/etiologia , Traumatismos da Medula Espinal/reabilitação , Vértebras Torácicas
12.
Am J Transplant ; 13(3): 738-45, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23311355

RESUMO

In this prospective study we analyzed pretransplant interferon-γ secretion by cytomegalovirus (CMV)-specific CD8+ T cells to assess its possible utility in determining the risk of CMV replication after solid organ transplantation. A total of 113 lung and kidney transplant patients were enrolled in the study but only 55 were evaluable. All CMV-seronegative recipients were pretransplant "nonreactive" (IFNγ <0.2 IU/mL) (11/11), whereas 30/44 (68.2%) CMV-seropositive (R+) recipients were "reactive" (IFNγ ≥0.2 IU/mL) and 14/44 (31.8%) were "nonreactive". In the R(+) "nonreactive" group, 7/14 (50%) developed posttransplant CMV replication, whereas the virus replicated only in 4/30 (13.3%) of the R(+) "reactive" patients (p = 0.021). According to the best multivariate model, pretransplant "nonreactive" recipients receiving an organ from a CMV-seropositive donor had a 10-fold increased risk of CMV replication compared to pretransplant "reactive" recipients (adjusted OR 10.49, 95% CI 1.88-58.46). This model displayed good discrimination ability (AUC 0.80) and calibration (Hosmer-Lemeshow test, p = 0.92). Negative and positive predictive values were 83.7% and 75%, respectively. The accuracy of the model was 82%. Therefore, assessment of interferon-γ secretion by cytomegalovirus (CMV)-specific CD8+ T cells prior to transplantation is useful in informing the risk of posttransplant CMV replication in solid organ transplant patients.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/patogenicidade , Rejeição de Enxerto/diagnóstico , Interferon gama/metabolismo , Transplante de Rim/efeitos adversos , Transplante de Pulmão/efeitos adversos , Adulto , Idoso , Antivirais/uso terapêutico , Biomarcadores/sangue , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/etiologia , Feminino , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/etiologia , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Adulto Jovem
13.
Oper Dent ; 47(3): 239-246, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35604838

RESUMO

The aim of this clinical report is to present a possible alternative treatment, with 24-month follow-up, for restoring tooth loss due to extensive erosive tooth wear. A 21-year-old male patient, complaining of intense sensitivity in the maxillary posterior teeth, and presenting severe wear on maxillary premolar and molar teeth due to gastroesophageal reflux, sought care in the university clinics. The planned treatment was to refer for medical treatment and perform restorations with the high-viscosity glass ionomer cement Equia Forte (GC Corporation, Tokyo, Japan), aiming to restore the dental anatomy and to consequently decrease the pain symptomatology. A silicone guide, obtained from a diagnostic waxing, was used during the restorative approach considering the patient's occlusion. After all the clinical steps of the restorative technique, an occlusal adjustment of restorations was performed. During monthly recalls up to 24 months, the treatment was stable and in service. In addition, the patient reported no pain and improved chewing, leading to a better quality of life.


Assuntos
Cárie Dentária , Cimentos de Ionômeros de Vidro , Adulto , Coroas , Cárie Dentária/terapia , Restauração Dentária Permanente/métodos , Cimentos de Ionômeros de Vidro/uso terapêutico , Humanos , Masculino , Qualidade de Vida , Viscosidade , Adulto Jovem
14.
Rev Sci Instrum ; 93(9): 093508, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36182487

RESUMO

This paper describes two new helical arrays of magnetic coils recently installed inside the TJ-II vacuum vessel. Their main objective is the precise measurement of the spatial periodicity of the magnetohydrodynamic perturbations usually found in the TJ-II plasmas. Given the high probability of coil failures due to the harsh plasma environment and in view of the extremely difficult access to the TJ-II vessel interior for maintenance, the coil system has been divided in two quasi-identical helical arrays. Both arrays consist of 32 triaxial sensors measuring orthogonal components of the local magnetic field along an ideal helical path whose trajectory runs close to the plasma edge. A description of the main characteristics of coils and arrays as well as their nominal positioning along an ideal helical path, inside the vessel, is given. A precise experimental determination of the real spatial orientation of the coils is performed by comparing the signals measured in current ramp-up and ramp-down experiments with calculations based on a filamentary model for the TJ-II magnetic coils. After this fine calibration procedure, it is possible to analyze the dependence of the amplitude of the measured magnetic field and its fluctuations as a function of the coil distance to the last closed flux surface. The study of the phase evolution of the parallel and perpendicular oscillatory components is also enabled. Finally, two examples of mode number determination are shown. One corresponds to a low frequency mode appearing in pure electron cyclotron resonance heating plasma, and the other one shows several modes observed during combined injection of both co and counter neutral beams and identified as shear Alfvén waves.

16.
Eksp Klin Gastroenterol ; (3): 60-7, 2011.
Artigo em Russo | MEDLINE | ID: mdl-21698811

RESUMO

UNLABELLED: The alverina citrate and simethicone combination (ACS-Meteospazmil) is used for irritable bowel syndrome (IBS) for almost 20 years, but the supporting scientific evidence for efficacy is limited. OBJECTIVE: to evaluate the effectiveness of ACS in patients with abdominal pain and discomfort at IBS. METHODS: In a double-blind, randomized, placebo-controlled study enrolled 412 patients with IBS conform to Rome criteria III. Selection criterion in the study was to evaluate the intensity of abdominal pain or discomfort during the 2-week run-in period without medication, which according to analog scale (VAS) was to be 60-100 mm. With the help of an interactive voice communication system (IVCS), patients were randomized to treatment with either alverin citrate 60 mg with Simethicone 300 mg three times daily or corresponding placebo for 4 weeks. RESULTS: For analyze of the results of the study were selected 409 patients. After 4 weeks, patients treated with ACS, was observed lower scores in the VAS assessment of abdominal pain or discomfort compared to placebo (mean--40 and 50 mm, p = 0.047) and a higher level of response to treatment (46.8% and 34.3%, respectively). Recorded side effects were similar in both groups. CONCLUSION: The combination of ACS was significantly more effective in patients with IBS compared to placebo in reducing abdominal pain or discomfort.


Assuntos
Dor Abdominal/tratamento farmacológico , Síndrome do Intestino Irritável/tratamento farmacológico , Propilaminas/uso terapêutico , Dor Abdominal/etiologia , Administração Oral , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Hungria , Síndrome do Intestino Irritável/complicações , Masculino , Pessoa de Meia-Idade , Medição da Dor , Polônia , Propilaminas/administração & dosagem , Qualidade de Vida , Resultado do Tratamento
17.
Clin Biomech (Bristol, Avon) ; 82: 105252, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33497989

RESUMO

BACKGROUND: Foot pain is a highly prevalent health problem for which measures such as a pattern of Pressure Discomfort Threshold of the foot plantar surface can provide valuable information for orthosis design. This study aimed to describe such pattern as a tool for the assessment of painful conditions of the feet and to analyse how it modifies according to age, gender and obesity. METHODS: A cross-sectional study was performed with participants allocated in: Group 1 people aged 20 to 35 years, Group 2 aged 50 to 65 years and Group 3 aged over 65. Pressure Discomfort Threshold on twelve points of the foot plantar surface was measured with an adapted manual dynamometer. Inferential analyses of the data were performed using one-way analysis of variance (ANOVA) considering foot areas, age group, gender and obesity. FINDINGS: 36 participants were analysed. The pattern of Pressure Discomfort Threshold for all individuals showed a significantly higher threshold on the heel and external foot (P < 0.001, η2 = 0.124) and was statistical significantly influenced by age (P < 0.001, η2 = 0.17), especially in participants aged over 65; by gender, with women having higher values (P < 0.001, η2 = 0.13), and by obesity (P < 0.001, η2 = 0.19). INTERPRETATION: A Pressure Discomfort Threshold pattern exists in the foot plantar surface. The characteristics of the discomfort pattern of the foot and its association with aging, gender and obesity may have considerable implications for orthosis and footwear design.


Assuntos
Envelhecimento/fisiologia , , Obesidade/fisiopatologia , Limiar da Dor/fisiologia , Pressão , Caracteres Sexuais , Adulto , Idoso , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Aparelhos Ortopédicos
18.
Eur Phys J C Part Fields ; 81(10): 959, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34790033

RESUMO

We report the results of a search for a new vector boson ( A ' ) decaying into two dark matter particles χ 1 χ 2 of different mass. The heavier χ 2 particle subsequently decays to χ 1 and an off-shell Dark Photon A ' ∗ → e + e - . For a sufficiently large mass splitting, this model can explain in terms of new physics the recently confirmed discrepancy observed in the muon anomalous magnetic moment at Fermilab. Remarkably, it also predicts the observed yield of thermal dark matter relic abundance. A detailed Monte-Carlo simulation was used to determine the signal yield and detection efficiency for this channel in the NA64 setup. The results were obtained re-analyzing the previous NA64 searches for an invisible decay A ' → χ χ ¯ and axion-like or pseudo-scalar particles a → γ γ . With this method, we exclude a significant portion of the parameter space justifying the muon g-2 anomaly and being compatible with the observed dark matter relic density for A ' masses from 2 m e up to 390 MeV and mixing parameter ε between 3 × 10 - 5 and 2 × 10 - 2 .

19.
Eur Phys J C Part Fields ; 80(12): 1159, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33343226

RESUMO

Recently, the ATOMKI experiment has reported new evidence for the excess of e + e - events with a mass ∼ 17 MeV in the nuclear transitions of 4 He, that they previously observed in measurements with 8 Be. These observations could be explained by the existence of a new vector X 17 boson. So far, the search for the decay X 17 → e + e - with the NA64 experiment at the CERN SPS gave negative results. Here, we present a new technique that could be implemented in NA64 aiming to improve the sensitivity and to cover the remaining X 17 parameter space. If a signal-like event is detected, an unambiguous observation is achieved by reconstructing the invariant mass of the X 17 decay with the proposed method. To reach this goal an optimization of the X 17 production target, as well as an efficient and accurate reconstruction of two close decay tracks, is required. A dedicated analysis of the available experimental data making use of the trackers information is presented. This method provides independent confirmation of the NA64 published results [1], validating the tracking procedure. The detailed Monte Carlo study of the proposed setup and the background estimate show that the goal of the proposed search is feasible.

20.
Science ; 216(4553): 1427-9, 1982 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-6124037

RESUMO

When injected continuously into the lateral ventricles of the rat, somatostatin increased the frequency of the migrating myoelectric complexes of the small intestine in a dose-related manner. A significant increase was obtained at a dose as low as 0.066 picomole per minute. In contrast, cholecystokinin octapeptide decreased the frequency of the migrating myoelectric complex of the small intestine or disrupted this pattern when injected into the lateral ventricle at rates of 0.073 to 0.23 picomole per minute. These findings support the hypothesis that somatostatin and cholecystokinin octapeptide act on central nervous system structures that are involved in the control of intestinal motility.


Assuntos
Colecistocinina/farmacologia , Motilidade Gastrointestinal , Somatostatina/farmacologia , Animais , Colecistocinina/administração & dosagem , Colecistocinina/análogos & derivados , Relação Dose-Resposta a Droga , Injeções Intraventriculares , Masculino , Ratos , Ratos Endogâmicos , Somatostatina/administração & dosagem
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