613 research outputs found
Effect of particle size distribution and calcium aluminate cement on the rheological behaviour of all-alumina refractory castables
Previous works based on statistical design of experiments (DoE) defined a model all-alumina self-flow refractory castable (SFRC) with optimized particle size distribution for simultaneous high flowability index (FI) and superior post-sintering performance. This work compares the SFRC rheological behaviour and setting time with those of alternative all-alumina castables with different Andreasen aggregate particle size distribution modulus, and of the equivalent castables containing calcium aluminate cement. The model castable showed Bingham behaviour with low yield stress, viscosity and thixotropy, guaranteeing easier casting and less wear in the casting and/or projection equipment. However, as the coarse particle fraction increases, the castable flow tends to be non-linear and changes from Bingham to Herschel–Bulkley. The cement containing castables quickly loose flowability despite the applied shear. This work confirmed previous conclusions based on FI measurements and demonstrates the adequacy of the use of FI values in the calculation of FI response surface by DoE.info:eu-repo/semantics/publishedVersio
Human and murine IFIT1 proteins do not restrict infection of negative-sense RNA viruses of the Orthomyxoviridae, Bunyaviridae, and Filoviridae families
UNLABELLED: Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) is a host protein with reported cell-intrinsic antiviral activity against several RNA viruses. The proposed basis for the activity against negative-sense RNA viruses is the binding to exposed 5\u27-triphosphates (5\u27-ppp) on the genome of viral RNA. However, recent studies reported relatively low binding affinities of IFIT1 for 5\u27-ppp RNA, suggesting that IFIT1 may not interact efficiently with this moiety under physiological conditions. To evaluate the ability of IFIT1 to have an impact on negative-sense RNA viruses, we infected Ifit1(-/-) and wild-type control mice and primary cells with four negative-sense RNA viruses (influenza A virus [IAV], La Crosse virus [LACV], Oropouche virus [OROV], and Ebola virus) corresponding to three distinct families. Unexpectedly, a lack of Ifit1 gene expression did not result in increased infection by any of these viruses in cell culture. Analogously, morbidity, mortality, and viral burdens in tissues were identical between Ifit1(-/-) and control mice after infection with IAV, LACV, or OROV. Finally, deletion of the human IFIT1 protein in A549 cells did not affect IAV replication or infection, and reciprocally, ectopic expression of IFIT1 in HEK293T cells did not inhibit IAV infection. To explain the lack of antiviral activity against IAV, we measured the binding affinity of IFIT1 for RNA oligonucleotides resembling the 5\u27 ends of IAV gene segments. The affinity for 5\u27-ppp RNA was approximately 10-fold lower than that for non-2\u27-O-methylated (cap 0) RNA oligonucleotides. Based on this analysis, we conclude that IFIT1 is not a dominant restriction factor against negative-sense RNA viruses.
IMPORTANCE: Negative-sense RNA viruses, including influenza virus and Ebola virus, have been responsible for some of the most deadly outbreaks in recent history. The host interferon response and induction of antiviral genes contribute to the control of infections by these viruses. IFIT1 is highly induced after virus infection and reportedly has antiviral activity against several RNA and DNA viruses. However, its role in restricting infection by negative-sense RNA viruses remains unclear. In this study, we evaluated the ability of IFIT1 to inhibit negative-sense RNA virus replication and pathogenesis both in vitro and in vivo. Detailed cell culture and animal studies demonstrated that IFIT1 is not a dominant restriction factor against three different families of negative-sense RNA viruses
GEOMETRIC ANALYSIS BY CONSTRUCTAL DESIGN OF STIFFENED STEEL PLATES UNDER BENDING WITH TRANSVERSE I-SHAPED OR T-SHAPED STIFFENERS
Several stiffened plates arrangements subjected to bending were configured applying the Constructal Design Method (CDM) and solved by Finite Element Method (FEM), aiming through the Exhaustive Search (ES) technique analyze the influence of transverse I-Shaped or T-Shaped stiffeners in mechanical behavior. Considering a non-stiffened plate as reference and maintaining the total steel volume constant, a portion of the reference plate was deducted from its thickness, and transformed into stiffeners through the ???? volume fraction parameter, which represents the ratio between the steel volume of the stiffeners and the steel volume of the reference plate. Assuming ???? = 0.3, 25 plates with just I-Shaped stiffeners in longitudinal and transverse directions and 25 plates with I-Shaped stiffeners in longitudinal direction and T-Shaped stiffeners in transverse direction were proposed. The results showed that the plates with transverse T-Shaped stiffeners are more effective, reducing the maximum von Mises stress and maximum deflection, respectively, in up to more than 60% and 50% when compared with the plates with just I-Shaped stiffeners
Dynamics of a Cistus salviifolius L. community after experimental disturbances. Patterns of structure and biomass recover
Estudou-se a dinâmica de regeneração da estrutura e biomassa de
uma comunidade arbustiva dominada por Cistus salviifolius
L., após intervenção experimental (corte da biomassa
arbustiva, com incorporação, deposição e extracção), durante
5 anos.
Verificou-se uma tendência de regeneração da comunidade,
através de um processo de auto-sucessão, após a intervenção.
A densidade arbustiva máxima foi registada no primeiro ano,
no segundo na parcela de deposição, tendo o máximo sido
menos acentuado na parcela de extracção. A altura dos
arbustos e a biomassa produzida aumentaram durante todo o
período de estudo. Contudo, enquanto a biomassa foliar
aumentou apenas nos 3 primeiros anos após a intervenção, a
biomassa lenhosa e a necromassa ainda continuavam a
aumentar no final do período do estudo. A razão de peso
foliar (LWR) atingiu, assim, o máximo no primeiro ano,
diminuindo posteriormente até ao final do período de estudo,
sendo o decréscimo na parcela de incorporação menos
pronunciado. Observaram-se algumas diferenças, entre os 3
tipos de intervenção, apenas nos 3 primeiros anos. No final
dos 5 anos que durou o estudo, os valores de densidade,
altura, biomassa e índices de área, registados para os arbustos
de C. salviifolius, eram semelhantes nas 3 parcelas. Contudo,
enquanto a densidade dos arbustos era ainda bastante mais
elevada do que na situação pré-tratamentos, a sua altura
média era próxima da inicial. Os valores de biomassa, quer
total quer dos seus componentes, assim como os do índice de
área foliar (LAI), pelo contrário, eram ainda bastante
inferiores aos obtidos antes da intervenção, principalmente na
parcela de incorporação
Sacral Fractures and Associated Injuries.
STUDY DESIGN: Literature review.
OBJECTIVE: The aim of this review is to describe the injuries associated with sacral fractures and to analyze their impact on patient outcome.
METHODS: A comprehensive narrative review of the literature was performed to identify the injuries associated with sacral fractures.
RESULTS: Sacral fractures are uncommon injuries that result from high-energy trauma, and that, due to their rarity, are frequently underdiagnosed and mistreated. Only 5% of sacral fractures occur in isolation. Injuries most often associated with sacral fractures include neurologic injuries (present in up to 50% of sacral fractures), pelvic ring disruptions, hip and lumbar spine fractures, active pelvic/ abdominal bleeding and the presence of an open fracture or significant soft tissue injury. Diagnosis of pelvic ring fractures and fractures extending to the lumbar spine are key factors for the appropriate management of sacral fractures. Importantly, associated systemic (cranial, thoracic, and abdominopelvic) or musculoskeletal injuries should be promptly assessed and addressed. These associated injuries often dictate the management and eventual outcome of sacral fractures and, therefore, any treatment algorithm should take them into consideration.
CONCLUSIONS: Sacral fractures are complex in nature and often associated with other often-missed injuries. This review summarizes the most relevant associated injuries in sacral fractures and discusses on their appropriate management
Portable dehumidifiers as an original matrix for the study of inhalable nanoparticles in school
Good air quality is documented as a significant factor of social justice. The human health hazards associated with air pollution are not distributed equally across cities; the most vulnerable people are more exposed to ambient air as they commute to work and wait for buses or trains at the stations. Aerosols play important roles in atmosphere quality and the climate; their oxidation at the nanoscale level may possibly increase the reactivity and toxicity of atmospheric particulates. Indoor school environments are characterized by high concentrations of different airborne particulate and gaseous pollutants. The documentation of nanoparticles (NPs), ultra-fine particles (UFPs), and micron-size particle species present in indoor primary schools are an important aspect in the recognition of their influence in respirational difficulties and decreased cognitive progress in children. This work utilizes the study of condensed water, sampled with portable dehumidifiers (PD), to describe NPs and UFPs in the vapor stage of enclosed zones. The acquired extracts were analyzed by advanced electron microscopy techniques. A total of 392 NPs and 251 UFPs were examined in a set of 22 samples acquired in moderately limited or inadequately ventilated indoor areas from several schools. Noting that NPs-related disorders happen at particular places of respirational structure, identification of site-specific NPs accumulation should be anticipated in direction to better verify the corresponding human health outcomes resulting from respirable NPs
Human And Murine Ifit1 Proteins Do Not Restrict Infection Of Negative-sense Rna Viruses Of The Orthomyxoviridae, Bunyaviridae, And Filoviridae Families
Interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) is a host protein with reported cell-intrinsic antiviral activity against several RNA viruses. The proposed basis for the activity against negative-sense RNA viruses is the binding to exposed 5'-triphosphates (5'-ppp) on the genome of viral RNA. However, recent studies reported relatively low binding affinities of IFIT1 for 5'-ppp RNA, suggesting that IFIT1 may not interact efficiently with this moiety under physiological conditions. To evaluate the ability of IFIT1 to have an impact on negative-sense RNA viruses, we infected Ifit1(-/-) and wild-type control mice and primary cells with four negative-sense RNA viruses (influenza A virus [IAV], La Crosse virus [LACV], Oropouche virus [OROV], and Ebola virus) corresponding to three distinct families. Unexpectedly, a lack of Ifit1 gene expression did not result in increased infection by any of these viruses in cell culture. Analogously, morbidity, mortality, and viral burdens in tissues were identical between Ifit1(-/-) and control mice after infection with IAV, LACV, or OROV. Finally, deletion of the human IFIT1 protein in A549 cells did not affect IAV replication or infection, and reciprocally, ectopic expression of IFIT1 in HEK293T cells did not inhibit IAV infection. To explain the lack of antiviral activity against IAV, we measured the binding affinity of IFIT1 for RNA oligonucleotides resembling the 5' ends of IAV gene segments. The affinity for 5'-ppp RNA was approximately 10-fold lower than that for non-2'-O-methylated (cap 0) RNA oligonucleotides. Based on this analysis, we conclude that IFIT1 is not a dominant restriction factor against negative-sense RNA viruses. IMPORTANCE Negative-sense RNA viruses, including influenza virus and Ebola virus, have been responsible for some of the most deadly outbreaks in recent history. The host interferon response and induction of antiviral genes contribute to the control of infections by these viruses. IFIT1 is highly induced after virus infection and reportedly has antiviral activity against several RNA and DNA viruses. However, its role in restricting infection by negative-sense RNA viruses remains unclear. In this study, we evaluated the ability of IFIT1 to inhibit negative-sense RNA virus replication and pathogenesis both in vitro and in vivo. Detailed cell culture and animal studies demonstrated that IFIT1 is not a dominant restriction factor against three different families of negative-sense RNA viruses.891894659476Division of Intramural Research, NIAID, NIHNIH grant [F32 AI112274][U54 AI057160][R01 AI104972][R01 AI104002
Antibodies Against Glycolipids Enhance Antifungal Activity of Macrophages and Reduce Fungal Burden After Infection with Paracoccidioides brasiliensis
Paracoccidioidomycosis is a fungal disease endemic in Latin America. Polyclonal antibodies to acidic glycosphingolipids (GSLs) from Paracoccidioides brasiliensis opsonized yeast forms in vitro increasing phagocytosis and reduced the fungal burden of infected animals. Antibodies to GSL were active in both prophylactic and therapeutic protocols using a murine intratracheal infection model. Pathological examination of the lungs of animals treated with antibodies to GSL showed well-organized granulomas and minimally damaged parenchyma compared to the untreated control. Murine peritoneal macrophages activated by IFN-gamma and incubated with antibodies against acidic GSLs more effectively phagocytosed and killed P brasiliensis yeast cells as well as produced more nitric oxide compared to controls. The present work discloses a novel target of protective antibodies against P brasiliensis adding to other well-studied mediators of the immune response to this fungus.CapesFAPESPUniv Sao Paulo, Dept Microbiol, Inst Biomed Sci, Sao Paulo, BrazilUniv Sao Paulo, Lab Med Mycol IMTSP LIM53, Sao Paulo, BrazilAlbert Einstein Coll Med, Dept Med, New York, NY USAAlbert Einstein Coll Med, Dept Microbiol & Immunol, New York, NY USAUniv Fed Fluminense, Niteroi, RJ, BrazilUniv Fed Sao Paulo, Dept Microbiol Immunol & Parasitol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Microbiol Immunol & Parasitol, Sao Paulo, BrazilFAPESP: 2011/17267-4FAPESP: 2013/18655-3Web of Scienc
The Metallicity Distribution Functions of SEGUE G and K dwarfs: Constraints for Disk Chemical Evolution and Formation
We present the metallicity distribution function (MDF) for 24,270 G and
16,847 K dwarfs at distances from 0.2 to 2.3 kpc from the Galactic plane, based
on spectroscopy from the Sloan Extension for Galactic Understanding and
Exploration (SEGUE) survey. This stellar sample is significantly larger in both
number and volume than previous spectroscopic analyses, which were limited to
the solar vicinity, making it ideal for comparison with local volume-limited
samples and Galactic models. For the first time, we have corrected the MDF for
the various observational biases introduced by the SEGUE target selection
strategy. The SEGUE sample is particularly notable for K dwarfs, which are too
faint to examine spectroscopically far from the solar neighborhood. The MDF of
both spectral types becomes more metal-poor with increasing |Z|, which reflects
the transition from a sample with small [alpha/Fe] values at small heights to
one with enhanced [alpha/Fe] above 1 kpc. Comparison of our SEGUE distributions
to those of two different Milky Way models reveals that both are more
metal-rich than our observed distributions at all heights above the plane. Our
unbiased observations of G and K dwarfs provide valuable constraints over the
|Z|-height range of the Milky Way disk for chemical and dynamical Galaxy
evolution models, previously only calibrated to the solar neighborhood, with
particular utility for thin- and thick-disk formation models.Comment: 70 pages, 25 figures, 7 tables. Accepted by The Astrophysical Journa
Effects of morphine on the expression of cytokines and inflammatory mediators in a rabbit model of endotoxin-induced experimental uveitis
- …