372 research outputs found
Sorption of Plutonium on a Biotite Mineral
It is necessary to obtain the data of some parameters concerning migration behavior of radionuclides in underground water for the safety assessment of radioactive waste disposal. Sorption and desorption experiments were carried out by using tracer amount of plutonium on biotite in a granitic rock. In this study, pH dependence of distribution coefficients of plutonium on a biotite mineral were measured. The following results are obtained; (1) The biotite has the pH buffer capacity at around pH 5. (2) Plutonium sorption rate was fast around pH 6 but slow at lower pH than 5. (3) The 95 percent of plutonium was sorbed on biotite at around pH 5. (4) The 10 to 30 percent of sorbed plutonium in biotite was desorbed with 1N KCl, the 50 to 60 percent with 1N HN0_3. (5) The rest of plutonium sorbed in biotite could not be desorbed even with 1N HN0_3. (6) The neutral plutonyl hydroxide could be an important species sorbed on the biotite.sorptionplutoniumbiotit
Cryo-EM structures and binding of mouse and human ACE2 to SARS-CoV-2 variants of concern indicate that mutations enabling immune escape could expand host range.
Investigation of potential hosts of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is crucial to understanding future risks of spillover and spillback. SARS-CoV-2 has been reported to be transmitted from humans to various animals after requiring relatively few mutations. There is significant interest in describing how the virus interacts with mice as they are well adapted to human environments, are used widely as infection models and can be infected. Structural and binding data of the mouse ACE2 receptor with the Spike protein of newly identified SARS-CoV-2 variants are needed to better understand the impact of immune system evading mutations present in variants of concern (VOC). Previous studies have developed mouse-adapted variants and identified residues critical for binding to heterologous ACE2 receptors. Here we report the cryo-EM structures of mouse ACE2 bound to trimeric Spike ectodomains of four different VOC: Beta, Omicron BA.1, Omicron BA.2.12.1 and Omicron BA.4/5. These variants represent the oldest to the newest variants known to bind the mouse ACE2 receptor. Our high-resolution structural data complemented with bio-layer interferometry (BLI) binding assays reveal a requirement for a combination of mutations in the Spike protein that enable binding to the mouse ACE2 receptor
A PROBLEMÁTICA DO MONITORAMENTO DAS INFECÇÕES DE SÍTIO CIRÚRGICO E A NECESSIDADE DE PADRONIZAÇÃO DE CRITÉRIOS PARA SEU DIAGNÓSTICO E NOTIFICAÇÃO.
Las infecciones hospitalarias (IH) ocurren como un problema de salud pública mundial, siendo la Infección del Sitio Quirúrgico la tercera topografia más común, de 14% a 16% de todas las IH. Cuando un paciente muere por una causa asociada a la IH, 77% están relacionadas con la ISC; 93% de ellas con infecciones serias que invaden órganos o espacios accedidos durante un procedimiento quirúrgico. Directamente, las repercusiones de las ISC aparecen en los costos hospitalarios, pues aumentan la
permanencia hospitalaria entre 7 a 10 días, amén de las readmisiones; pero, de manera indirecta, igualmente o más importante, están los costos indirectos que causan impactos emocionales desastrosos en los pacientes y en la familia.
Los criterios más utilizados para diagnóstico de ISC son los Centers for Diseases Control (CDC); otros criterios desarrollados por especialistas ingleses como el National Prevalence Survey Study (NPS) también son utilizados. El objetivo de este estudio fue buscar una respuesta, en la literatura, para la práctica del controlador de infección hospitalaria en lo que respecta a la existencia de un “patrón-oro” para el diagnóstico de ISC, con el fin de soportar los resultados obtenidos y las consecuentes acciones. Una
revisión sistemática ha mostrado que comparándose las definiciones del CDC y NPS de 93 heridas operatorias, 24% han quedado sin diagnóstico al utilizarse criterios del CDC y 19% cuando se utilizaron criterios del NPS.
La conclusión de este estudio es que no hay un “patrón-oro” para el diagnóstico de ISC, pues el juicio es subjetivo, y sujeto a variaciones de acuerdo con el observador. Es necesario que cada servicio de salud junto al grupo Comissão de Controle de Infeccção Hospitalar -CCIH (Comisión de Control de Infección
Hospitalaria) asuma y reglamente, por medio de la mejor evidencia científica, cuáles son los mejores criterios para diagnóstico y notificación de ISC, cuál es el mejor método de trabajo para vigilancia después del alta, teniendo en cuenta la factibilidad y las necesidades locales.As infecções hospitalares (IH) surgem como um problema de saúde pública mundial sendo a Infecção de Sítio Cirúrgico (ISC) a terceira topografia mais comum, de 14% a 16% de todas as IH. Quando um paciente morre por causa associada à IH, 77% estão relacionadas a ISC; 93% deles com infecções sérias que invadem órgãos ou espaços acessados durante o procedimento
cirúrgico. Diretamente, as repercussões das ISC aparecem nos custos hospitalares pois aumentam a permanência hospitalar entre 7 a 10 dias, além das readmissões; mas de forma
indireta e tão ou mais importante, estão os custos indiretos que provocam impactos emocionais desastrosos nos pacientes e familiares.
Os critérios mais utilizados para diagnóstico de ISC são os do Centers for Diseases Control (CDC), outros critérios desenvolvidos por especialistas ingleses como o National Prevalence Survey Study (NPS) também são utilizados. O objetivo deste estudo foi buscar resposta, na literatura, para a pratica do controlador de infecção hospitalar no que tange a existência de um padrão ouro para o diagnostico de ISC, a fim de respaldar os resultados obtidos e as conseqüentes ações. Uma revisão sistemática mostrou que se comparando as definições do CDC e NPS de 93 feridas operatórias, 24% ficaram sem diagnóstico quando usados critérios do CDC e 19% quando usados critérios do NPS. A conclusão deste estudo é que não há padrão ouro, no diagnóstico de ISC, pois o julgamento é subjetivo e sujeito a variações de acordo com o observador. É preciso que cada serviço de saúde, junto ao grupo da Comissão de Controle de Infecção Hospitalar (CCIH) assuma e normatize, por meio da melhor evidência científica, quais os melhores critérios para diagnóstico e notificação de ISC, qual o melhor método de trabalho para vigilância no pós-alta; levando em conta a factibilidade e as necessidades locais
Chiral patterns arising from electrostatic growth models
Recently, unusual and strikingly beautiful seahorse-like growth patterns have
been observed under conditions of quasi-two-dimensional growth. These
`S'-shaped patterns strongly break two-dimensional inversion symmetry; however
such broken symmetry occurs only at the level of overall morphology, as the
clusters are formed from achiral molecules with an achiral unit cell. Here we
describe a mechanism which gives rise to chiral growth morphologies without
invoking microscopic chirality. This mechanism involves trapped electrostatic
charge on the growing cluster, and the enhancement of growth in regions of
large electric field. We illustrate the mechanism with a tree growth model,
with a continuum model for the motion of the one-dimensional boundary, and with
microscopic Monte Carlo simulations. Our most dramatic results are found using
the continuum model, which strongly exhibits spontaneous chiral symmetry
breaking, and in particular finned `S' shapes like those seen in the
experiments.Comment: RevTeX, 12 pages, 9 figure
Modified Whole-Mount In situ Hybridization Protocol for the Detection of Transgene Expression in Electroporated Chick Embryos
hybridization. hybridization (WISH).Here we describe a modification to the WISH protocol that is essential to prevent DNA cross-hybridization and to specifically detect transgene mRNA transcripts in electroporated embryos. Our optimized WISH procedure can be applied not only to electroporated chick embryos but also to other embryos or adult tissues that have been transfected with large amounts of reporter- or expression construct DNA
Assessing flow response of self-compacting mortar by Taguchi method and ANOVA interaction
Blood group terminology 2004: from the International Society of Blood Transfusion committee on terminology for red cell surface antigens
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73460/1/j.1423-0410.2004.00564.x.pd
Rapid Analysis of Listeria monocytogenes Cell Wall Teichoic Acid Carbohydrates by ESI-MS/MS
We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of Gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria
Stemness of the Organ of Corti Relates to the Epigenetic Status of Sox2 Enhancers
In the adult mammalian auditory epithelium, the organ of Corti, loss of sensory hair cells results in permanent hearing loss. The underlying cause for the lack of regenerative response is the depletion of otic progenitors in the cell pool of the sensory epithelium. Here, we show that an increase in the sequence-specific methylation of the otic Sox2 enhancers NOP1 and NOP2 is correlated with a reduced self-renewal potential in vivo and in vitro; additionally, the degree of methylation of NOP1 and NOP2 is correlated with the dedifferentiation potential of postmitotic supporting cells into otic stem cells. Thus, the stemness the organ of Corti is related to the epigenetic status of the otic Sox2 enhancers. These observations validate the continued exploration of treatment strategies for dedifferentiating or reprogramming of differentiated supporting cells into progenitors to regenerate the damaged organ of Corti
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