75 research outputs found
Possible solution of the Coriolis attenuation problem
The most consistently useful simple model for the study of odd deformed
nuclei, the particle-rotor model (strong coupling limit of the core-particle
coupling model) has nevertheless been beset by a long-standing problem: It is
necessary in many cases to introduce an ad hoc parameter that reduces the size
of the Coriolis interaction coupling the collective and single-particle
motions. Of the numerous suggestions put forward for the origin of this
supplementary interaction, none of those actually tested by calculations has
been accepted as the solution of the problem. In this paper we seek a solution
of the difficulty within the framework of a general formalism that starts from
the spherical shell model and is capable of treating an arbitrary linear
combination of multipole and pairing forces. With the restriction of the
interaction to the familiar sum of a quadrupole multipole force and a monopole
pairing force, we have previously studied a semi-microscopic version of the
formalism whose framework is nevertheless more comprehensive than any
previously applied to the problem. We obtained solutions for low-lying bands of
several strongly deformed odd rare earth nuclei and found good agreement with
experiment, except for an exaggerated staggering of levels for K=1/2 bands,
which can be understood as a manifestation of the Coriolis attenuation problem.
We argue that within the formalism utilized, the only way to improve the
physics is to add interactions to the model Hamiltonian. We verify that by
adding a magnetic dipole interaction of essentially fixed strength, we can fit
the K=1/2 bands without destroying the agreement with other bands. In addition
we show that our solution also fits 163Er, a classic test case of Coriolis
attenuation that we had not previously studied.Comment: revtex, including 7 figures(postscript), submitted to Phys.Rev.
Application of the Kerman-Klein method to the solution of a spherical shell model for a deformed rare-earth nucleus
Core-particle coupling models are made viable by assuming that core
properties such as matrix elements of multipole and pairing operators and
excitation spectra are known independently. From the completeness relation, it
is seen, however, that these quantities are themselves algebraic functions of
the calculated core-particle amplitudes. For the deformed rare-earth nucleus
158Gd, we find that these sum rules are well-satisfied for the ground state
band, implying that we have found a self-consistent solution of the non-linear
Kerman-Klein equations.Comment: revtex and postscript, including 1 figure(postscript), submitted to
Phys.Rev.Let
Trombolisis en el tromboembolismo de pulmĂłn
Fil: Valdivieso, W..
Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Ărea de CardiologĂaFil: Gambarte, A..
Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Ărea de CardiologĂaFil: PiasentĂn, J..
Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Ărea de CardiologĂaFil: Limia, P..
Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Ărea de CardiologĂ
Effectiveness of mRNA vaccine boosters against infection with the SARS-CoV-2 omicron (B.1.1.529) variant in Spain: a nationwide cohort study
Factor de impacto: 25,71 Q1Background: The omicron (B.1.1.529) variant of SARS-CoV-2 has increased capacity to elude immunity and cause breakthrough infections. The aim of this study was to estimate the effectiveness of mRNA-based vaccine boosters (third dose) against infection with the omicron variant by age, sex, time since complete vaccination, type of primary vaccine, and type of booster. Methods: In this nationwide cohort study, we linked data from three nationwide population registries in Spain (Vaccination Registry, Laboratory Results Registry, and National Health System registry) to select community-dwelling individuals aged 40 years or older, who completed their primary vaccine schedule at least 3 months before the start of follow-up, and had not tested positive for SARS-CoV-2 since the start of the pandemic. On each day between Jan 3, and Feb 6, 2022, we matched individuals who received a booster mRNA vaccine and controls of the same sex, age group, postal code, type of vaccine, time since primary vaccination, and number of previous tests. We estimated risk of laboratory-confirmed SARS-CoV-2 infection using the Kaplan-Meier method and compared groups using risk ratios (RR) and risk differences. Vaccine effectiveness was calculated as one minus RR. Findings: Between Jan 3, and Feb 6, 2022, 3â111â159 matched pairs were included in our study. Overall, the estimated effectiveness from day 7 to 34 after a booster was 51·3% (95% CI 50·2-52·4). Estimated effectiveness was 52·5% (51·3-53·7) for an mRNA-1273 booster and 46·2% (43·5-48·7) for a BNT162b2 booster. Effectiveness was 58·6% (55·5-61·6) if primary vaccination had been with ChAdOx1 nCoV-19 (Oxford-AstraZeneca), 55·3% (52·3-58·2) with mRNA-1273 (Moderna), 49·7% (48·3-51·1) with BNT162b2 (Pfizer-BioNTech), and 48·0% (42·5-53·7) with Ad26.COV2.S (Janssen). Estimated effectiveness was 43·6% (40·0-47·1) when the booster was administered between 151 days and 180 days after complete vaccination and 52·2% (51·0-53·3) if administered more than 180 days after primary scheduled completion. Interpretation: Booster mRNA vaccine-doses were moderately effective in preventing infection with the omicron variant of SARS-CoV-2 for over a month after administration, which indicates their suitability as a strategy to limit the health effects of COVID-19 in periods of omicron variant domination. Estimated effectiveness was higher for mRNA-1273 compared with BNT162b2 and increased with time between completed primary vaccination and booster.S
Ab initio screening methodology applied to the search for new permanent magnetic materials
In this paper a computational high-throughput screening (HTS) approach to the search for alternative permanent magnetic materials is presented. Systems considered for a start are binary intermetallic compounds composed of rare-earth (RE) and transition metal (TM) elements. With the tight-binding-linear muffin-tin-orbital-atomic-sphere-approximation (TBLMTO-ASA) method of density functional theory (DFT) a variety of REâTM intermetallic phases is investigated and their magnetic properties are obtained at rather low computational costs. Next, interstitial elements such as boron, carbon and nitrogen in these phases are considered. For promising candidate phases with high and stable spontaneous ferromagnetic polarization, the calculated local magnetic moments and exchange coupling parameters, as obtained from TB-LMTO-ASA calculations, are then used for Monte Carlo simulations to identify candidates with sufficiently high Curie temperatures (Tc). Finally, magnetocrystalline anisotropy constants (K1) of the most promising candidate phases are calculated with accurate, potential-shape-unrestricted DFT calculations using the Vienna ab initio simulation package. The computational HTS procedure is illustrated by results for a selection of hard-magnetic REâTM phases like RETM5, RE2TM17 and RE2TM14B
Evaluation of genotypic and phenotypic methods for differentiation of the members of the Anginosus group streptococci
The terminology and classification of the Anginosus group streptococci has been inconsistent. We tested the utility of 16S rRNA gene and tuf gene sequencing and conventional biochemical tests for the reliable differentiation of the Anginosus group streptococci. Biochemical testing included Rapid ID 32 Strep, API Strep, Fluo-Card Milleri, Wee-tabs, and Lancefield antigen typing. Altogether, 61 Anginosus group isolates from skin and soft tissue infections and four reference strains were included. Our results showed a good agreement between 16S rRNA gene and tuf gene sequencing. Using the full sequence was less discriminatory than using the first part of the 16S rRNA gene. The three species could not be separated with the API 20 Strep test. Streptococcus intermedius could be differentiated from the other two species by ÎČ-galactosidase (ONPG) and ÎČ-N-acetyl-glucosaminidase reactions. Rapid ID 32 Strep ÎČ-glucosidase reaction was useful in separating S. anginosus strains from S. constellatus. In conclusion, both 16S rRNA gene and tuf gene sequencing can be used for the reliable identification of the Anginosus group streptococci. S. intermedius can be readily differentiated from the other two species by phenotypic tests; however, 16S rRNA gene or tuf gene sequencing may be needed for separating some strains of S. constellatus from S. anginosus
EpidemiologĂa molecular y anĂĄlisis filogenĂ©tico de la infecciĂłn por el virus del papiloma humano en mujeres con lesiones cervicales y cĂĄncer en la regiĂłn litoral del Ecuador
The aim of the present study was to gather information regarding the molecular epidemiology of Human papillomavirus (HPV) and related risk factors in a group of women with low- and high-grade cervical lesions and cancer from the coastal region of Ecuador. In addition, we studied the evolution of HPV variants from the most prevalent types and provided a temporal framework for their emergence, which may help to trace the source of dissemination within the region. We analyzed 166 samples, including 57 CIN1, 95 CIN2/3 and 14 cancer cases. HPV detection and typing was done by PCR-sequencing (MY09/MY11). HPV variants and estimation of the time to most recent common ancestor (tMRCA) was assessed through phylogeny and coalescence analysis. HPV DNA was found in 54.4% of CIN1, 74.7% of CIN2/3 and 78.6% of cancer samples. HPV16 (38.9%) and HPV58 (19.5%) were the most prevalent types. Risk factors for the development of cervical lesions/cancer were the following: three or more pregnancies (OR = 4.3), HPV infection (OR = 3.7 for high-risk types; OR = 3.5 for HPV16), among others. With regard to HPV evolution, HPV16 isolates belonged to lineages A (69%) and D (31%) whereas HPV58 isolates belonged only to lineage A. The period of emergence of HPV16 was in association with human populations (tMRCA = 91. 052 years for HPV16A and 27. 000 years for HPV16D), whereas HPV58A preceded Homo sapiens evolution (322. 257 years). This study provides novel data on HPV epidemiology and evolution in Ecuador, which will be fundamental in the vaccine era.Fil: Bedoya Pilozo, Cesar H.. Escuela Superior PolitĂ©cnica del Litoral; Ecuador. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Medina MagĂŒes, Lex G.. Escuela Superior PolitĂ©cnica del Litoral; EcuadorFil: Espinosa GarcĂa, Maylen. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: SĂĄnchez, Martha. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Parrales Valdiviezo, Johanna V.. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Molina, Denisse. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Ibarra, MarĂa A.. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Quimis Ponce, MarĂa. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: España, Karool. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: PĂĄrraga Macias, Karla E.. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Cajas Flores, Nancy V.. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Solon, Orlando A.. Instituto Nacional de Investigaciones en Salud PĂșblica; Ecuador. Universidad Agraria del Ecuador; EcuadorFil: Robalino Penaherrera, Jorge A.. Instituto Nacional de Investigaciones en Salud PĂșblica; EcuadorFil: Chedraui, Peter. Hospital Gineco-ObstĂ©trico Enrique C. Sotomayor; EcuadorFil: Escobar, Saul. Universidad CatĂłlica de Guayaquil; EcuadorFil: Loja Chango, Rita D.. Universidad CatĂłlica de Guayaquil; EcuadorFil: Ramirez MorĂĄn, Cecibel. Universidad CatĂłlica de Guayaquil; EcuadorFil: Espinoza Caicedo, Jasson. Universidad CatĂłlica de Guayaquil; EcuadorFil: SĂĄnchez Giler, Sunny. Universidad Especialidades EspĂritu Santo. Facultad de Ciencias MĂ©dicas; EcuadorFil: Limia, Celia M.. Instituto de Medicina Tropical Pedro Kouri; CubaFil: AlemĂĄn, Yoan. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Soto, Yudira. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Kouri, Vivian. Instituto de Medicina Tropical Pedro Kouri; CubaFil: Culasso, AndrĂ©s Carlos Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa. CĂĄtedra de VirologĂa; ArgentinaFil: Badano, Ines. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste; Argentina. SecretarĂa de EducaciĂłn Superior, Ciencia, TecnologĂa e InnovaciĂłn; Ecuador. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, QuĂmicas y Naturales. Laboratorio de BiologĂa Molecular Aplicada; Argentin
Streptococcus intermedius causing infective endocarditis and abscesses: a report of three cases and review of the literature
<p>Abstract</p> <p>Background</p> <p><it>Streptococcus intermedius </it>is a member of the Streptococcus anginosus group. Clinical disease with <it>S. intermedius </it>is characterized by abscess formation and rarely endocarditis. Identification of <it>Streptococcus intermedius </it>is difficult, leading to the development of molecular methods to more accurately identify and characterize this organism.</p> <p>Case presentation</p> <p>Over a period of 6 months we encountered three cases of invasive <it>Streptococcus intermedius </it>infection presenting as hepatic abscesses, brain abscess, and endocarditis. We confirmed our microbiologic diagnosis through 16S sequencing and found a common virulence gene in each case.</p> <p>Conclusion</p> <p>Our report illustrates three different clinical manifestations due to <it>Streptococcus intermedius </it>infection that can be encountered in healthy individuals in a community hospital setting. To our knowledge, this is the first case of <it>Streptococcus intermedius </it>endocarditis confirmed by 16S sequencing analysis. The use of molecular methods may allow a better understanding of the epidemiology and pathogenesis of this organism.</p
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