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1.
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.
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.

6.
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
9.
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 .

10.
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.

12.
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
13.
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.

14.
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.

15.
Arq. bras. med. vet. zootec. (Online) ; 71(6): 2041-2048, Nov.-Dec. 2019. ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1055131

RESUMO

A 15-year-old, mixed breed, male horse was attended with a history of multiple abscesses in the cervical region with a three-year evolution. Upon admission, three fistulous tracts with drainage of purulent secretions in the cervical region, low body score, restriction of cervical movements, and painful sensitivity to palpation were observed. The horse was diagnosed with osteomyelitis secondary to Streptococcus equi infection. The initial treatment was antibiotic therapy and local curative. Owing to the lack of response, surgical debridement was performed. An initial favorable response was observed; however, after 4 months, drainage recurred, and the animal was euthanized. A post-mortem computed tomography scan was performed to obtain details of the injury. Cervical osteomyelitis is rare, and its occurrence through hematogenous spread in adult horses and the tomographic findings had not been reported previously. The long period of evolution, difficulty in performing an aggressive debridement, and the presence of multi-drug resistant bacteria contributed to the negative outcome.(AU)


Um equino macho, sem raça definida, de 15 anos de idade, foi atendido com histórico de múltiplos abscessos cervicais com evolução de três anos. Na admissão, foram observados: três trajetos fistulosos com drenagem de material purulento na região cervical; baixo escore corporal; restrição de movimentos cervicais; e sensibilidade dolorosa à palpação da região. Foi diagnosticada osteomielite vertebral cervical secundária à infecção por Streptococcus equi. O tratamento inicial consistiu na administração de antibióticos e curativo local. Na ausência de resposta à terapia, realizou-se o debridamento cirúrgico. Inicialmente, obteve-se uma resposta favorável, entretanto, após quatro meses, houve recidiva da lesão e o animal foi submetido à eutanásia. Realizou-se tomografia computadorizada no post mortem para detalhamento da lesão. A osteomielite vertebral cervical é rara, e sua ocorrência por meio de disseminação hematógena em animais adultos não foi previamente reportada. O longo período de evolução, aliado à dificuldade de realização de um debridamento agressivo, e a característica multirresistente do agente etiológico contribuíram para o desfecho negativo do caso.(AU)


Assuntos
Animais , Osteomielite/veterinária , Infecções Estreptocócicas/complicações , Vértebras Cervicais/patologia , Streptococcus equi , Cavalos
16.
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.

17.
Arq. bras. med. vet. zootec. (Online) ; 71(5): 1686-1694, set.-out. 2019. tab
Artigo em Português | VETINDEX, LILACS | ID: biblio-1038671

RESUMO

O objetivo deste trabalho foi avaliar a pastagem, o desempenho, o conforto térmico e os parâmetros hematológicos de bovinos Nelore na fase de terminação em sistemas integrados de produção agropecuária com duas densidades de árvores (ILPF-1L= 196 árvores ha-1 e ILPF-3L=448 árvores ha-1) e em pleno sol (ILP). Foram avaliados a massa e a composição morfológica da forragem, o ganho médio diário, o ganho de peso por área e a taxa de lotação no verão e no outono, bem como as variáveis climáticas dos sistemas em três horários e parâmetros hematológicos dos animais (n=60). A massa de forragem foi superior no tratamento ILP e no verão (P<0,05). Porém, a redução da massa de forragem nos sistemas ILPFs não interferiu no desempenho dos animais (P>0,05). A temperatura ambiente, a temperatura do globo e o índice de temperatura e umidade foram melhores nos tratamentos com sombreamento e no período da manhã, proporcionando maior conforto aos animais, sendo ainda confirmado pelo menor volume globular dos bovinos em ILP (P<0,05). Conclui-se que os sistemas com componente arbóreo diminuem a massa de forragem, mas essa redução não altera o desempenho dos animais na fase de terminação. Além disso, os sistemas ILPFs melhoram o conforto térmico, entretanto essa melhora não foi suficiente para favorecer o desempenho.(AU)


The objective of this work was to evaluate pasture, performace, thermal comfort, and haematological parameters of Nellore cattle in the finishing phase in integrated crop-livestock systems with two tree densities (ICLF-1L= 196 ha -1 trees and ICLF-3L= 448 ha -1 trees) and in full sun (ICL). The forage mass morphological composition of the pasture average daily gain, weight gain per area, stocking rate of the animals were evaluated in summer and autumn, and the climatic variables of systems we evaluated at three different times, and haematological parameters of the animals (n= 60). The forage mass was higher in the ICL treatment and summer (P<0.05). However, the reduction of the forage mass in the ILPFs systems did not interfere with the performance of the animals (P>0.05). Ambient temperature, globe temperature and temperature and humidity index were better in shade treatments and in the morning, providing greater comfort to the animals, and was also confirmed by the lower globular volume of the bovines in ICL (P<0.05). It is concluded that the systems with trees reduce the forage mass but this reduction does not alter the animals' performance in the finishing phase. In addition, ICLFs improve the thermal comfort of the animals, however, this improvement was not enough to favor their performance.(AU)


Assuntos
Animais , Bovinos , Bem-Estar do Animal , Aumento de Peso , Pastagens/métodos , Resposta ao Choque Térmico , Pinus taeda , Poaceae/anatomia & histologia , Criação de Animais Domésticos/métodos
18.
Braz J Med Biol Res ; 52(9): e8224, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31482975

RESUMO

Leishmaniasis is a neglected disease that affects a large part of the world population. Knowing the sand fly fauna of a region is of fundamental importance for guiding health surveillance actions related to the prevention and control of leishmaniasis. A total of 86 specimens of sand flies (60 females and 26 males) were collected. Using the classification proposed by Galati (2003), the following species were identified: Lutzomyia longipalpis (Lutz & Neiva, 1912), Migonemyia migonei (França, 1920), Evandromyia cortelezzi (Brethes, 1923), Ev. sallesi (Galvão & Coutinho, 1939), Nyssomyia whitmani (Atunes & Coutinho, 1939), Psathyromyia lutziana (Costa Lima, 1932), Ev. lenti (Mangabeira, 1938), Brumptomyia sp. (França and Parrot, 1921), and Pressatia sp. (Mangabeira, 1942). Using PCR with internal transcribed spacer target to identify infected sand flies, five Lu. longipalpis females were infected with Leishmania spp. Despite the small number of specimens collected, considerable species diversity was found in the study area.


Assuntos
Insetos Vetores/classificação , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Psychodidae/classificação , Psychodidae/parasitologia , Animais , Brasil , DNA Espaçador Ribossômico/genética , Feminino , Leishmania/genética , Leishmaniose/transmissão , Masculino , Reação em Cadeia da Polimerase , RNA de Protozoário/genética
19.
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
20.
Braz. j. med. biol. res ; 52(9): e8224, 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1019569

RESUMO

Leishmaniasis is a neglected disease that affects a large part of the world population. Knowing the sand fly fauna of a region is of fundamental importance for guiding health surveillance actions related to the prevention and control of leishmaniasis. A total of 86 specimens of sand flies (60 females and 26 males) were collected. Using the classification proposed by Galati (2003), the following species were identified: Lutzomyia longipalpis (Lutz & Neiva, 1912), Migonemyia migonei (França, 1920), Evandromyia cortelezzi (Brethes, 1923), Ev. sallesi (Galvão & Coutinho, 1939), Nyssomyia whitmani (Atunes & Coutinho, 1939), Psathyromyia lutziana (Costa Lima, 1932), Ev. lenti (Mangabeira, 1938), Brumptomyia sp. (França and Parrot, 1921), and Pressatia sp. (Mangabeira, 1942). Using PCR with internal transcribed spacer target to identify infected sand flies, five Lu. longipalpis females were infected with Leishmania spp. Despite the small number of specimens collected, considerable species diversity was found in the study area.


Assuntos
Animais , Masculino , Feminino , Psychodidae/classificação , Psychodidae/parasitologia , RNA de Protozoário/genética , Insetos Vetores/classificação , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Brasil , Leishmaniose/transmissão , Reação em Cadeia da Polimerase , DNA Espaçador Ribossômico/genética , Leishmania/genética
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