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1.
Phys Rev Lett ; 115(23): 231102, 2015 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-26684106

RESUMEN

Binary-driven hypernovae (BdHNe) within the induced gravitational collapse paradigm have been introduced to explain energetic (E_{iso}≳10^{52} erg), long gamma-ray bursts (GRBs) associated with type Ic supernovae (SNe). The progenitor is a tight binary composed of a carbon-oxygen (CO) core and a neutron-star (NS) companion, a subclass of the newly proposed "ultrastripped" binaries. The CO-NS short-period orbit causes the NS to accrete appreciable matter from the SN ejecta when the CO core collapses, ultimately causing it to collapse to a black hole (BH) and producing a GRB. These tight binaries evolve through the SN explosion very differently than compact binaries studied in population synthesis calculations. First, the hypercritical accretion onto the NS companion alters both the mass and the momentum of the binary. Second, because the explosion time scale is on par with the orbital period, the mass ejection cannot be assumed to be instantaneous. This dramatically affects the post-SN fate of the binary. Finally, the bow shock created as the accreting NS plows through the SN ejecta transfers angular momentum, braking the orbit. These systems remain bound even if a large fraction of the binary mass is lost in the explosion (well above the canonical 50% limit), and even large kicks are unlikely to unbind the system. Indeed, BdHNe produce a new family of NS-BH binaries unaccounted for in current population synthesis analyses and, although they may be rare, the fact that nearly 100% remain bound implies that they may play an important role in the compact merger rate, important for gravitational waves that, in turn, can produce a new class of ultrashort GRBs.

2.
Infect Genet Evol ; 103: 105322, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35753623

RESUMEN

Cross-species transmission events and mixed infection of small ruminant lentiviruses (SRLVs) were studied in seven goats and two sheep from three small ruminant mixed flocks from Northeast and Southeast Brazil. Genetic and antigenic analyses with gag/env genes and ELISA multiepitope SU1/SU5 recombinant antigens were carried out, respectively. The genetic analysis of gag and env sequences showed high viral diversity in both species, MVV-like (subtype A1) and CAEV-like B1 in goats, and CAEV-like (subtype B1) in sheep, revealing SRLV interspecies transmission from sheep to goats and vice versa in Brazilian farms. Two Brazilian caprine lentiviruses were segregated in two new genetic clades based on gag analyses, which suggests a new classification into heterogenic genotype A. Furthermore, goat isolates were grouped into subtype A1 and B1 clusters. Cross-reactive antibodies were detected in goats using ELISA with a recombinant antigen carrying SU1 and SU5 immunodominant epitopes; the results showed anti-CAEV and MVV antibodies in goats and anti-CAEV antibodies in sheep. This result can be associated with the high divergence in the V4 region due to SRLV variability. All results confirm cross-species infection of SRLV in Brazilian mixed herds.


Asunto(s)
Enfermedades de las Cabras , Infecciones por Lentivirus , Enfermedades de las Ovejas , Animales , Brasil/epidemiología , Cabras , Lentivirus/genética , Infecciones por Lentivirus/veterinaria , Filogenia , Rumiantes , Ovinos
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 224: 117340, 2020 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-31330420

RESUMEN

This work reports a theoretical and experimental study on the electronic and vibrational properties of Bi2(MoO4)3. First-principle calculations were applied to increase the understanding on the properties of the chemical composition through the energy bands. The conduction band minimum (CBM) is found at the high symmetric Γ-point, while the valence-band maximum (VBM) is located between the Z and the Γ-points. Therefore, these facts confirm that the Bi2(MoO4)3 crystal is a semiconductor compound with an indirect band-gap of about 2.1 eV. Moreover, lattice dynamic properties were calculated using density functional perturbation theory (DFPT) in order to assign the experimental Raman bands. In addition, we performed temperature-dependent Raman spectroscopic studies in the Bi2(MoO4)3 crystals to obtain information on structural changes induced by effects of the temperature change. From the changes observed in the Raman spectra phase transitions at ∼ 668 and 833 K were inferred, with the last one possibly related to the disorder due to the heating process.

4.
Acta Odontol Latinoam ; 22(3): 183-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20302217

RESUMEN

This experimental light microscopy study investigated the formation of a hybrid layer and resin tags on sound dentin, after utilization of conventional and self-etching adhesive systems. After restorative procedures, the specimens were decalcified in a formic acid and sodium citrate solution, embedded in paraffin, sectioned at 6-microm thickness and stained by the Brown & Brenn method for analysis and measurement by light microscopy (AXIOPHOT) (400x). The results were statistically analyzed by analysis of variance, at a significance level of 5%. Based on the results, it could be concluded that the conventional adhesive allowed the formation of a thicker hybrid layer than the self-etching adhesive, with similar penetration into the dentinal tubules (resin tags).


Asunto(s)
Cementos Dentales , Grabado Dental , Dentina , Adulto , Humanos , Técnicas In Vitro , Adulto Joven
5.
Cardiovasc Res ; 47(3): 567-73, 2000 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-10963729

RESUMEN

OBJECTIVE: The aim of this work was to investigate the effect of vitamin E (VE) supplementation on the formation of autoantibodies against oxidized low density lipoproteins (LDL) in a hyperlipidemic animal model. METHODS: Thirty-four male hamsters (Mesocricetus auratus), (4 weeks old) were divided into three groups: Group A (n=9) was fed with standard rodent chow; group B (n=13) was fed with a standard rodent chow plus 2% cholesterol and 10% butter and group C (n=12) was fed with the same diet plus 0.2% (w/w) VE. Blood samples were collected by intracardiac puncture and antibody levels were determined in each animal at 4 weeks of age and after 20 weeks of experimental diet. A modified ELISA technique was used to analyze the modulation of autoantibody titers against an epitope of oxidized LDL in serum samples. Antigens prepared for the ELISA tests were characterized using spectrofluorimetry. Serum VE levels were determined in the lipidic fractions by HPLC. RESULTS: The groups fed with cholesterol-fat enriched diet presented a three-fold increase in total serum cholesterol and two-fold increase in serum triglycerides compared to the control group. VE supplementation played no role in serum cholesterol and serum triglyceride concentrations but led to a decreased autoantibody (anti-LDL-malondialdehyde) formation (P<0.05). CONCLUSIONS: Our results show that VE supplementation leads to a lower production of autoantibodies against oxidized LDL, suggesting a protective effect of VE against in vivo oxidation of LDL particles, in a dose-dependent manner.


Asunto(s)
Autoanticuerpos/sangre , Suplementos Dietéticos , Hiperlipidemias/tratamiento farmacológico , Lipoproteínas LDL/inmunología , Vitamina E/administración & dosificación , Análisis de Varianza , Animales , Colesterol/administración & dosificación , Colesterol/sangre , Cricetinae , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática/métodos , Hiperlipidemias/inmunología , Hiperlipidemias/metabolismo , Peroxidación de Lípido , Lípidos/sangre , Lipoproteínas LDL/metabolismo , Masculino , Malondialdehído/metabolismo , Espectrometría de Fluorescencia , Triglicéridos/sangre , Vitamina E/sangre
6.
Oper Dent ; 37(6): E1-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22621163

RESUMEN

This clinical study assessed the performance of posterior composite resins applied with the Adper™ Single Bond Plus (SB) and Adper™ Scotchbond SE (SE) adhesive systems and Filtek™ Supreme Plus composite resin, using modified US Public Health Service criteria. A total of 97 restorations were placed in posterior teeth by two calibrated operators. Application of the materials followed manufacturers' instructions. The restorations were evaluated by two examiners at baseline and after one year. Statistical analyses were conducted using the proportion test at a significance level of 5% (p<0.05). All the restorations evaluated (ie, 100%) received an alpha rating for the criteria of marginal discoloration and marginal integrity at baseline. At one year, for marginal discoloration, 64.6% of SB and 61.2% of SE received an alpha rating. For marginal integrity, 72.9% of SB and 77.6% of SE received an alpha rating. The other restorations received bravo ratings for both criteria. None of the teeth that received the restorative systems presented caries lesions around the restorations. A total of eight teeth presented postoperative sensitivity one week after baseline, five with SB and three with SE; the symptom had disappeared one year later. One year later, composite resin restorations using either adhesive system showed satisfactory clinical performance.


Asunto(s)
Resinas Compuestas/química , Materiales Dentales/química , Restauración Dental Permanente/normas , Recubrimientos Dentinarios/química , Grabado Ácido Dental/métodos , Adolescente , Bisfenol A Glicidil Metacrilato/química , Bisfenol A Glicidil Metacrilato/normas , Color , Resinas Compuestas/normas , Caries Dental/clasificación , Adaptación Marginal Dental , Materiales Dentales/normas , Restauración Dental Permanente/clasificación , Sensibilidad de la Dentina/clasificación , Femenino , Estudios de Seguimiento , Humanos , Masculino , Ensayo de Materiales , Cementos de Resina/química , Cementos de Resina/normas , Propiedades de Superficie , Resultado del Tratamiento , Adulto Joven
8.
Braz J Med Biol Res ; 42(10): 988-92, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19784482

RESUMEN

The influence of aging on memory has been extensively studied, but the importance of short-term memory and recall sequence has not. The objective of the current study was to examine the recall order of words presented on lists and to determine if age affects recall sequence. Physically and psychologically healthy male subjects were divided into two groups according to age, i.e., 23 young subjects (20 to 30 years) and 50 elderly subjects (60 to 70 years) submitted to the Wechsler Adult Intelligence Scale-Revised and the free word recall test. The order of word presentation significantly affected the 3rd and 4th words recalled (P < 0.01; F = 14.6). In addition, there was interaction between the presentation order and the type of list presented (P < 0.05; F = 9.7). Also, both groups recalled the last words presented from each list (words 13-15) significantly more times 3rd and 4th than words presented in all remaining positions (P < 0.01). The order of word presentation also significantly affected the 5th and 6th words recalled (P = 0.05; F = 7.5) and there was a significant interaction between the order of presentation and the type of list presented (P < 0.01; F = 20.8). The more developed the cognitive functions, resulting mainly from formal education, the greater the cognitive reserve, helping to minimize the effects of aging on the long-term memory (episodic declarative).


Asunto(s)
Envejecimiento/fisiología , Cognición/fisiología , Memoria a Corto Plazo/fisiología , Recuerdo Mental/fisiología , Pruebas Neuropsicológicas , Adulto , Anciano , Humanos , Masculino , Adulto Joven
9.
Hum Reprod ; 16(10): 2227-9, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11574520

RESUMEN

Two cases of patients with ruptured ovarian pregnancies (P1 = ovarian heterotopic and P2 = primary ovarian ectopic) after intracytoplasmic sperm injection and blastocyst transfer are presented. Laparoscopy was performed on day 40 and day 27 after transfer in cases P1 and P2 respectively. In both cases the ectopic pregnancies were located on the left ovary and were successfully removed by laparoscopy preserving the ovaries. In case P1 the intrauterine pregnancy was not affected. A healthy boy was born after 37 weeks of pregnancy. In this way, potential fertility of the patients and the intrauterine pregnancy were maintained. These cases occurred during a series of blastocyst transfers in which 129 pregnancies were obtained. There were no cases of ovarian ectopic/heterotopic pregnancies from January 1996 to September 1999 in 814 pregnancies obtained from day 2 or day 3 embryo transfers. Because the ovarian ectopic pregnancies occurred in patients with day 5 embryo transfer who otherwise did not have any predisposing factors for ectopic pregnancy, it is advisable to conduct a large scale analysis of future data about the possible association between blastocyst-stage embryo transfer and the somewhat higher risk of unexpected complications of clinical outcome.


Asunto(s)
Implantación del Embrión , Transferencia de Embrión/efectos adversos , Embarazo Ectópico/etiología , Embarazo Ectópico/patología , Inyecciones de Esperma Intracitoplasmáticas , Adulto , Femenino , Humanos , Recién Nacido , Trabajo de Parto , Laparoscopía , Masculino , Embarazo , Embarazo Ectópico/cirugía , Embarazo Múltiple
10.
Braz. j. med. biol. res ; 42(10): 988-992, Oct. 2009. ilus, tab
Artículo en Inglés | LILACS | ID: lil-526194

RESUMEN

The influence of aging on memory has been extensively studied, but the importance of short-term memory and recall sequence has not. The objective of the current study was to examine the recall order of words presented on lists and to determine if age affects recall sequence. Physically and psychologically healthy male subjects were divided into two groups according to age, i.e., 23 young subjects (20 to 30 years) and 50 elderly subjects (60 to 70 years) submitted to the Wechsler Adult Intelligence Scale-Revised and the free word recall test. The order of word presentation significantly affected the 3rd and 4th words recalled (P < 0.01; F = 14.6). In addition, there was interaction between the presentation order and the type of list presented (P < 0.05; F = 9.7). Also, both groups recalled the last words presented from each list (words 13-15) significantly more times 3rd and 4th than words presented in all remaining positions (P < 0.01). The order of word presentation also significantly affected the 5th and 6th words recalled (P = 0.05; F = 7.5) and there was a significant interaction between the order of presentation and the type of list presented (P < 0.01; F = 20.8). The more developed the cognitive functions, resulting mainly from formal education, the greater the cognitive reserve, helping to minimize the effects of aging on the long-term memory (episodic declarative).


Asunto(s)
Adulto , Anciano , Humanos , Masculino , Adulto Joven , Envejecimiento/fisiología , Cognición/fisiología , Memoria a Corto Plazo/fisiología , Recuerdo Mental/fisiología , Pruebas Neuropsicológicas , Adulto Joven
11.
Acta odontol. latinoam ; 22(3): 183-189, 2009. tab, graf, ilus
Artículo en Inglés | LILACS | ID: lil-585593

RESUMEN

This experimental light microscopy study investigated the formation of a hybrid layer and resin tags on sound dentin, after utilization of conventional and self-etching adhesive systems. Afterrestorative procedures, the specimens were decalcified in a formic acid and sodium citrate solution, embedded in paraffin, sectioned at 6-ìm thickness and stained by the Brown & Brenn method for analysis and measurement by light microscopy (AXIOPHOT) (400x). The results were statistically analyzed by analysis of variance, at a significance level of 5%. Based on the results, it could be concluded that the conventional adhesive allowed the formation of a thicker hybrid layer than the self-etching adhesive, with similar penetration into the dentinal tubules (resin tags).


Analisamos nesta pesquisa laboratorial/microscópica, o poder deformação da camada híbrida de adesão e dos prolongamentos resinosos (tags) em tecido dentinário hígido, empregando, para tanto, nesse substrato dental, um sistema adesivo convencional e outro autocondicionante. Após a realização dos procedimentosrestauradores; os espécimes foram descalcificados em solução de ácido fórmico/citrato de sódio, incluídos em parafina, cortados a uma espessura de 6 micrometros, corados pelo método Brown & Brenn, para posteriormente, serem analisados e mensurados emmicroscopia óptica comum (AXIOPHOT) (400X). Após a coleta dos resultados, estes foram submetidos à análise estatística ANOVA, ao nível de 5%. De acordo com os resultados obtidospudemos concluir que o adesivo convencional possibilitou a formaçãode uma camada híbrida de adesão mais espessa do que o adesivo autocondicionante e um mesmo nível penetração no interior do túbulo dentinário (Tags).


Asunto(s)
Recubrimientos Dentinarios/química , Resinas Compuestas , Dentina , Grabado Ácido Dental/métodos , Análisis de Varianza , Microscopía/métodos
12.
Rev. bras. cir ; 71(1): 33-5, 1981.
Artículo en Portugués | LILACS | ID: lil-3935

RESUMEN

Os autores estudaram o padrao segmentar arterial do rim de natimortos atraves de 33 moldes obtidos por corrosao. A divisao primaria e secundaria da arteria renal e sua distribuicao foram observadas e relacionadas a formacao dos segmentos. Os moldes mostraram predominancia de tres ou quatro segmentos (36,4% e 39,4%, respectivamente). A presenca do segmento posterior ocorreu em 90,9% e o padrao classico de cinco segmentos ocorreu em apenas 15,1% dos casos


Asunto(s)
Muerte Fetal , Nefrectomía , Arteria Renal
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