21 research outputs found
Clinical evaluation of near-infrared light transillumination (NIRT) as an interproximal caries detection tool in a large sample of patients in a private practice
No full textBackground: A study has been carried out in order to evaluate in vivo the diagnostic performance of near-infrared light transillumination (NIRT) compared to digital radiographic examination (RE) in the detection of class II carious lesions. Methods: A total of 114 patients were included, and 2957 proximal surfaces were considered. Surfaces were imaged by means of NIRT and radiographed with a photostimulable phosphor system. NIRT and radiographic images were observed by two blinded operators. Their diagnoses were compared with those made while visiting the patients, when visual-tactile, radiographic and NIRT data were matched by expert operators to obtain the reference diagnoses. Sensitivity, specificity and inter-observer consistency were calculated. Results: Throughout the visits, 395 caries were detected. When investigating without clinical information and in a blind manner, RE performed significantly better than NIRT regarding sensitivity analysis (0.591 vs. 0.456, p<0.001), and NIRT performed significantly better than RE regarding specificity analysis (0.980 vs 0.933, p<0.001). However, NIRT showed sensitivity similar to RE when only enamel caries were concerned. With regard to the agreement between the two observers, NIRT performed significantly better than RE (0.901 for RE analysis, 0.989 for NIRT analysis, P<0.001). A high probability of false positives for enamel caries (95% from 0.699 to 0.791) was observed in RE. NIRT was very likely to detect and correct the erroneous positive diagnosis of enamel carious lesions obtained using RE (95% CI for probability from 0.938 to 0.979). Conclusions: NIRT should be used in caries diagnosis in combination with radiographic images. In fact, NIRT can help to correct a false positive diagnosis of enamel caries. Furthermore, NIRT could be used to detect caries in patients for whom non-urgent radiographic exposition is contraindicated and to monitor enamel caries in medically treated patients. Finally, thanks to its three-dimensional images, NIRT can aid in detecting small caries when performing minorly invasive restorative procedures
Heightened thrombin generation in individuals with resistance to activated protein C
No full textWe chose to evaluate whether or not a state of biochemical hypercoagulability was present in 74 individuals (69 heterozygotes and 5 homozygotes) resistant to activated protein C (APC) due to the Arg506 → Gln mutation in the factor V gene. To this end, plasma levels of two markers of thrombin formation, prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin complexes (TAT), were measured. High levels of F1 + 2 and TAT were found in 32% and 23% of APC-resistant individuals vs 4% in controls. The levels of these markers tended to be particularly elevated in three homozygous subjects. A significant positive correlation between F1 + 2 and TAT was present in APC-resistant individuals. No relationship between marker values and the previous occurrence of thrombotic episodes was found. Therefore, by measuring F1 + 2 and TAT a state of biochemical hypercoagulability has been identified in about one-third of APC-resistant individuals. This frequency is similar to that previously observed in comparable individuals with inherited deficiencies of protein C and protein S, which are usually associated with a stronger thrombotic tendency than APC-resistant individuals
Antibodies to SARS-CoV2 induced by vaccination and infection correlate with protection against the infection
No full textThe COVID-19 pandemic remained worldwide for almost three years, but little is known about the dynamics of
humoral immune response to the third dose over time and its protection from infection. Our aim was to assess the
humoral immune response after the third dose of the different vaccines administered to SARS-CoV-2 naive and
previously infected individuals, and its correlation with protection in an academic community.
For each person studied (185), three blood samples were taken between December 2021 and July 2022, one
month apart. Anti-S antibodies were quantified by ELISA, while anti-N antibody levels were determined by
ECLIA. Most of the participants had received two doses of viral vector-based, mRNA-based and virus-inactivated
vaccines.
Although anti-N antibody levels revealed that 80% of the individuals had been exposed to the virus before or
during the study, only 42% reported having been diagnosed.
When anti-S IgG levels were measured 3–5 months after the second dose of any vaccine, they were higher in
those previously infected individuals. The same results were observed for anti-N IgG levels in those who received
2 doses of the virus-inactivated vaccine.
When analyzing the dynamics of anti-S antibodies we observed that, although positive IgG antibody levels
were detected 5–6 months after the second dose administration, those observed 30–60 days after the third dose
were significantly higher and remained so for at least 8 months.
Higher levels of anti-S IgG antibodies at the first sampling were associated with a lower incidence of subse quent infection. The same association was seen in people who received the booster compared with those who
received two doses.
This study provides further evidence that anti-S IgG antibodies remained at high levels over time, and both
anti-S levels and the third dose of anti-SARS-CoV-2 vaccine correlate with protection against the infection. It also
shows that infection acts as a booster of immunization, increasing levels of both anti-N and anti-S IgG.EEA RafaelaFil: Flor, Noelia. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Inmunología Experimental; ArgentinaFil: García, María Ines. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Inmunología Experimental; ArgentinaFil: Molineri, Ana Ines. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Molineri, Ana Ines. Consejo Nacional de Ciencia y Tecnología (CONICET). Instituto de Investigación de la Cadena Láctea (IDICAL); ArgentinaFil: Molineri, Ana Ines. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Investigación de la Cadena Láctea (IDICAL); ArgentinaFil: Botasso, Oscar. Universidad Nacional de Rosario; ArgentinaFil: Botasso, Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Instituto de Inmunología clínica y Experimental de Rosario (IDICER); ArgentinaFil: Diez, Cristina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Biología Molecular e Inmunología Aplicadas; ArgentinaFil: Veaute; Carolina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Inmunología Experimental; ArgentinaFil: Veaute, Carolina. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas. Laboratorio de Biología Molecular e Inmunología Aplicadas; Argentin
Caracterización de una microdispersión de caucho reciclado de neumáticos en asfalto
No full textDebido a la gran producción y no reutilización de losneumáticos fuera de servicio en países donde no se cuentacon normativas claras, como es el caso de la RepúblicaArgentina, se ha pensado en valorar las propiedades yla factibilidad de inclusión en cementos asfálticos en caliente.El trabajo recorre las técnicas de trituración y de caracterización del polvo de neumáticos, diseña la tecnología para producir la microdispersión y generar el Sistema de Asfalto Caucho. Utilizando modernas técnicas se caracteriza el Sistema y se observan losbeneficios en sus prestaciones para ser empleado en mezclasasfálticas de alto desempeño. Se destaca sus bondades desde el punto de vista ambientales.DescriptoresMicrodispersión de caucho; Reciclado de neumáticos enasfalto; Sistema Asfalto CauchoAbstractDue to the great production and no re-use of tyres out ofuse in countries in which no clear rules are available, suchas Republic Argentina, it has been thought to assess theirproperties and possibility of inclusion in hot bitumens.This paper reviews the crushing and characterizationtechniques of tyre’s dust, design the technology to producemicro dispersion and generate the bitumen-rubber system,using modern techniques the system is characterized andhis benefits are seen in its uses in bitumen mixtures ofhigh performance. Marking the environmental strength.DescriptorsRubber Microdiffusion; Tires recycled in asphalt;Rubber Asphalt Syste
IFABP portal region insertion during membrane interaction depends on phospholipid composition
No full textIntestinal fatty acid-binding protein (IFABP) is highly expressed in the intestinal epithelium and it belongs to the family of soluble lipid binding proteins. These proteins are thought to participate in most aspects of the biology of lipids, regulating its availability for specific metabolic pathways, targeting and vectorial trafficking of lipids to specific subcellular compartments. The present study is based on the ability of IFABP to interact with phospholipid membranes, and we characterized its immersion into the bilayer´s hydrophobic central region occupied by the acyl-chains. We constructed a series of Trp-mutants of IFABP to selectively probe the interaction of different regions of the protein, particularly the elements forming the portal domain that is proposed to regulate the exit and entry of ligands to/from the binding cavity. We employed several fluorescent techniques based on selective quenching induced by soluble or membrane confined agents. The results indicate that the portal region of IFABP penetrates deeply into the phospholipid bilayer, especially when CL-containing vesicles are employed. The orientation of the protein and the degree of penetration were highly dependent on the lipid composition, the superficial net charge and the ionic strength of the medium. These results may be relevant to understand the mechanism of ligand transfer and the specificity responsible for the unique functions of each member of the FABP family.Fil: de Gerónimo, Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce. Area de Investigación en Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; ArgentinaFil: Rodriguez Sawicki, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; ArgentinaFil: Botasso Arias, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; ArgentinaFil: Franchini, Gisela Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; ArgentinaFil: Zamarreño, Fernando. Universidad Nacional del Sur. Departamento de Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Costabel, Marcelo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Bahía Blanca. Instituto de Física del Sur; Argentina. Universidad Nacional del Sur. Departamento de Física; ArgentinaFil: Corsico, Betina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; ArgentinaFil: Falomir Lockhart, Lisandro Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - La Plata. Instituto de Investigaciones Bioquímicas de la Plata; Argentin
ESTIMATING MARKUPS FROM PLANT-LEVEL DATA
No full textThis paper investigates the consequences of ignoring price heterogeneity on the estimation of markups using micro-data. I show that ignoring output price heterogeneity yields markup estimates severely biased towards one regardless of competitiveness levels. To do so, I set up an econometric model that assumes monopolistic competition and a CES demand function in a differentiated product market. This model controls for unobserved price heterogeneity and is easy to estimate since OLS is applicable. Using data from Colombian plants, the differentiated product model reveals markup estimates considerably higher than one, rejecting the hypothesis of competitive markets.
Does antidumping protection raise market power? Evidence from EU firm level data.
No full textThis paper empirically tests the effects of Anti-Dumping (AD) protection on the price-cost margin of firms. To this end, we use a rich panel data set of 1,666 EU producers that were involved in AD cases initiated in 1996. Our findings indicate that price-cost margins in most cases significantly increase in the period of protection compared to a period before protection. In industries where competition is very tough before protection, we fail to find an increase in price-cost margins, while in industries with positive markups before protection, trade policy raises market power between 3% points and 15 % points, depending on the sector. Our results are robust to alternative specifications and estimation techniques, controlling for unobservable fixed effects and potential endogeneity of the regressors. Our findings are also consistent with recent theoretical models that deal with the economic effects on price behaviour in response to AD protection.
Does antidumping protection raise market power? Evidence from EU firm level data.
No full textThis paper empirically tests the effects of Anti-Dumping (AD) protection on the price-cost margin of firms. To this end, we use a rich panel data set of 1,666 European producers that were involved in AD cases initiated in 1996. Our findings indicate that price-cost margins in most cases significantly increase in the period of protection compared to a period before protection. In industries where competition is very tough before protection, we fail to find an increase in price-cost margins, while in industries with positive markups before protection, trade policy raises market power between 3% points and 15 % points, depending on the sector. Our results are robust to alternative specifications and estimation techniques, controlling for unobservable fixed effects and potential endogeneity of the regressors. Our findings are also consistent with recent theoretical models that deal with the economic effects on price behaviour in response to AD protection.Antidumping cases; European producers; Market power;
Energy-Entropy-Momentum integration of discrete thermo-visco-elastic dynamics.
No full textA novel time integration scheme is presented for the numerical solution of the dynamics of discrete systems consisting of point masses and thermo-visco-elastic springs. Even considering fully coupled constitutive laws for the elements, the obtained solutions strictly preserve the two laws of thermo dynamics and the symmetries of the continuum evolution equations. Moreover, the unconditional control over the energy and the entropy growth have the effect of stabilizing the numerical solution, allowing the use of larger time steps than those suitable for comparable implicit algorithms. Proofs for these claims are provided in the article as well as numerical examples that illustrate the performance of the method
