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1.
Nature ; 602(7895): 63-67, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35110756

RESUMEN

Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.

2.
Eur Phys J C Part Fields ; 83(6): 467, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37303462

RESUMEN

The ICARUS collaboration employed the 760-ton T600 detector in a successful 3-year physics run at the underground LNGS laboratory, performing a sensitive search for LSND-like anomalous νe appearance in the CERN Neutrino to Gran Sasso beam, which contributed to the constraints on the allowed neutrino oscillation parameters to a narrow region around 1 eV2. After a significant overhaul at CERN, the T600 detector has been installed at Fermilab. In 2020 the cryogenic commissioning began with detector cool down, liquid argon filling and recirculation. ICARUS then started its operations collecting the first neutrino events from the booster neutrino beam (BNB) and the Neutrinos at the Main Injector (NuMI) beam off-axis, which were used to test the ICARUS event selection, reconstruction and analysis algorithms. ICARUS successfully completed its commissioning phase in June 2022. The first goal of the ICARUS data taking will be a study to either confirm or refute the claim by Neutrino-4 short-baseline reactor experiment. ICARUS will also perform measurement of neutrino cross sections with the NuMI beam and several Beyond Standard Model searches. After the first year of operations, ICARUS will search for evidence of sterile neutrinos jointly with the Short-Baseline Near Detector, within the Short-Baseline Neutrino program. In this paper, the main activities carried out during the overhauling and installation phases are highlighted. Preliminary technical results from the ICARUS commissioning data with the BNB and NuMI beams are presented both in terms of performance of all ICARUS subsystems and of capability to select and reconstruct neutrino events.

3.
Eur Phys J C Part Fields ; 78(4): 319, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29706795

RESUMEN

The VIolation of Pauli exclusion principle -2 experiment, or VIP-2 experiment, at the Laboratori Nazionali del Gran Sasso searches for X-rays from copper atomic transitions that are prohibited by the Pauli exclusion principle. Candidate direct violation events come from the transition of a 2p electron to the ground state that is already occupied by two electrons. From the first data taking campaign in 2016 of VIP-2 experiment, we determined a best upper limit of [Formula: see text] for the probability that such a violation exists. Significant improvement in the control of the experimental systematics was also achieved, although not explicitly reflected in the improved upper limit. By introducing a simultaneous spectral fit of the signal and background data in the analysis, we succeeded in taking into account systematic errors that could not be evaluated previously in this type of measurements.

4.
Plant Biol (Stuttg) ; 17(6): 1113-22, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26108256

RESUMEN

This study aimed to define progesterone 5ß-reductases (P5ßR, EC 1.3.99.6, enone 1,4-reductases) as function-associated molecular markers at the plant family level. Therefore cDNAs were isolated from 25 Brassicaceae species, including two species, Erysimum crepidifolium and Draba aizoides, known to produce cardiac glycosides. The sequences were used in a molecular phylogeny study. The cladogram created is congruent to the existing molecular analyses. Recombinant His-tagged forms of the P5ßR cDNAs from Aethionema grandiflorum, Draba aizoides, Nasturtium officinale, Raphanus sativus and Sisymbrium officinale were expressed in E. coli. Enone 1,4-reductase activity was demonstrated in vitro using progesterone and 2-cyclohexen-1-one as substrates. Evidence is provided that functional P5ßRs are ubiquitous in the Brassicaceae. The recombinant P5ßR enzymes showed different substrate preferences towards progesterone and 2-cyclohexen-1-one. Sequence comparison of the catalytic pocket of the P5ßR enzymes and homology modelling using Digitalis lanata P5ßR (PDB ID: 2V6G) as template highlighted the importance of the hydrophobicity of the binding pocket for substrate discrimination. It is concluded that P5ßR genes or P5ßR proteins can be used as valuable function-associated molecular markers to infer taxonomic relationship and evolutionary diversification from a metabolic/catalytic perspective.


Asunto(s)
Brassicaceae/genética , Genes de Plantas , Oxidorreductasas/genética , Filogenia , Proteínas de Plantas/genética , Progesterona Reductasa/genética , Secuencia de Aminoácidos , Brassicaceae/enzimología , Ciclohexanonas/metabolismo , ADN Complementario , Digitalis , Escherichia coli , Expresión Génica , Interacciones Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Oxidorreductasas/metabolismo , Proteínas de Plantas/metabolismo , Progesterona/metabolismo , Progesterona Reductasa/metabolismo , Especificidad por Sustrato
5.
Arq. bras. med. vet. zootec ; 68(4): 1099-1103, jul.-ago. 2016. ilus, tab
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-868456

RESUMEN

This report describes two cases of male cats affected by FLUTD (Feline lower urinary tract disease). The first patient had been affected by numerous relapses after passing through various therapeutic treatments and surgical interventions, and was subjected to the alternative protocol after being recommended for euthanasia, the second patient had no history of urinary tract disorders in the past, and was not subjected to any kind of previous treatment. The two patients had a significant improvement in their clinical condition, were not affected by relapses after participation in the alternative design, and were accompanied for about a year after their treatment.(AU)


Asunto(s)
Animales , Gatos , Dianthus/efectos de los fármacos , Fitoterapia/veterinaria , Urolitiasis/terapia , Urolitiasis/veterinaria , Enfermedades de los Gatos/terapia
6.
Rev. bras. plantas med ; 18(1): 105-112, jan.-mar. 2016. tab
Artículo en Portugués | LILACS | ID: lil-780044

RESUMEN

RESUMO Este trabalho teve por objetivo avaliar o efeito bactericida in vitro de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica (ETEC). Dentre os óleos essenciais estudados, três foram extraídos in situ por arraste a vapor e treze foram adquiridos comercialmente. Todos os óleos foram analisados por CG-EM e CG-DIC. A atividade bactericida foi avaliada pelo método de microdiluição utilizando-se caldo triptona de soja e microplacas de poliestireno de 96 poços, com posterior plaqueamento das culturas em ágar triptona de soja. Os óleos essenciais de Cinnamomum cassia e de Thymus vulgaris apresentaram concentração mínima bactericida (CMB) de 0,12% e 0,25%, respectivamente. Já os óleos comerciais de Syzygium aromaticum e Origanum vulgare apresentaram ambos CMB de 0,50% e os óleos extraídos in situ de Cymbopogon citratus e Origanum vulgare apresentaram ambos CMB de 1,00%. Os dezesseis óleos essenciais apresentaram composição química qualitativa e quantitativa distintas. As análises químicas dos óleos essenciais de Cinnamomum cassia e de Thymus vulgaris tiveram a presença majoritária de E-cinamaldeído (84,52%) e timol (50,89%). Conclui-se que os óleos de C. cassia e T. vulgaris foram os mais eficazes na inibição do crescimento in vitro dessa bactéria, a qual possui diferentes níveis de sensibilidade dependendo da composição química do óleo.


ABSTRACT This study aimed to evaluate the bactericidal effect in vitro of sixteen essential oils on enterotoxigenic Escherichia coli (ETEC). Among the essential oils, three were extracted in situ by steam distillation and thirteen were purchased commercially. All oils were analyzed by GC-MS and GC-FID. The bactericidal activity was evaluated by the microdilution method using tryptone soy broth, and 96-well polystyrene microplates with subsequent plating of the cultures in tryptone soy agar. Cinnamomum cassia and Thymus vulgaris essential oils showed minimal bactericidal concentration (MBC) 0.12% and 0.25%, respectively. Both commercial oils of Syzygium aromaticum and Origanum vulgare showed MBC of 0.50% and the oils extracted in situ Origanum vulgare and Cymbopogon citratus showed both MBC of 1.00%. The sixteen essential oils pointed out distinct qualitative and quantitative chemical composition. Chemical analysis of Cinnamomum cassia and Thymus vulgaris oils had the predominant presence of E-cinnamaldehyde (84.52% ± 0.07%) and thymol (50.89% ± 0.31%). In conclusion, T. vulgaris and C. cassia oils were the most effective in inhibiting in vitro growth of this bacterium, which has different sensitivity levels depending on the chemical composition of the oil.


Asunto(s)
Aceites Volátiles/análisis , Química , Escherichia coli Enterotoxigénica/clasificación , Cromatografía de Gases/métodos , Cinnamomum zeylanicum , Thymus (Planta)/clasificación
7.
Rev. bras. plantas med ; 17(4,supl.3): 1199-1207, 2015. tab
Artículo en Portugués | LILACS | ID: lil-776614

RESUMEN

RESUMO Este artigo descreve a ocorrência, características botânicas, fitoquímicas e a composição nutricional do feijão guandu [Cajanus cajan (L.) Millsp], e sua relação no processo de inibição da falcização na doença falciforme, um distúrbio genético que acomete as hemácias, gerando hemólise e anemia crônica. Dois constituintes químicos estariam mais relacionados aos efeitos inibitórios na falcização de células falciformes: L-fenilalanina e o ácido p-hidroxibenzóico. Estudos químico-biológicos detalhados com o feijão guandu no Brasil poderão esclarecer melhor os mecanismos pelos quais ocorre a inibição da falcização das hemácias e a diminuição do estresse oxidativo, ajudando no tratamento de pessoas com DF.


ABSTRACT This article describes the occurrence, botanical characteristics, phytochemical and nutritional composition of pigeonpea [Cajanus cajan (L.) Millsp], and their relationship in the process inhibition of sickling in sickle cell disease (SCD), a genetic disorder that affects red blood cells, causing hemolysis and chronic anemia. Two chemical components would be related to the inhibitory effect on sickling of sickle cells: the L-phenylalanine and the p- hydroxybenzoic acid. In Brazil, detailed studies with pigeonpea chemical-biological may clarify the mechanisms by which the inhibition of sickling of red blood cells occurs, reducing oxidative stress and thus helping treating people affected by this disease.


Asunto(s)
Revisión , Cajanus/química , Anemia de Células Falciformes/clasificación , Plantas Medicinales/clasificación
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