Search

Discovery of off-target CRISPR–Cas activity in patient-derived cells and animal models is crucial for genome editing applications, but currently exhibits low sensitivity. We demonstrate that inhibition of DNA-dependent protein kinase catalytic subunit accumulates the repair protein MRE11 at CRISPR–Cas-targeted sites, enabling high-sensitivity mapping of off-target sites to positions of MRE11 binding using chromatin immunoprecipitation followed by sequencing. This technique, termed DISCOVER-Seq+, discovered up to fivefold more CRISPR off-target sites in immortalized cell lines, primary human cells and mice compared with previous methods. We demonstrate applicability to ex vivo knock-in of a cancer-directed transgenic T cell receptor in primary human T cells and in vivo adenovirus knock-out of cardiovascular risk gene PCSK9in mice. Thus, DISCOVER-Seq+ is, to our knowledge, the most sensitive method to-date for discovering off-target genome editing in vivo.

ABSTRACT The aim of this work is to study the influence of chloride ion in the mechanical, microstructural and chemical properties of concrete. For this purpose, four concrete mixes were [...]

A numerical study of forced imbibition into capillary tubes under primary Bjerknes force is presented. A mathematical model is developed to predict the motion of a meniscus while an external force is applied. Remarkable enhancement in liquid flow attributed to the frequency and intensity of a waveform on primary Bjerknes force and to the viscosity of fluid was observed. It was found that imbibition optimal frequency for each equilibrium height depends on the time as ω(xeq)∼emt, where the recovery time is a viscosity function t(xeq)∼μH. The results are presented in a set of curves, which reveal the features of enhanced oil recovery of the system under consideration. Some physical implications are discussed.

En este trabajo se presenta la implementación y la validación experimental de un observador de alta ganancia reconfigurable para la estimación de la composición molar y de la temperatura en una columna de destilación con una mezcla binaria. El observador está compuesto por un modelo matemático simplificado de la columna de destilación y por el cálculo y corrección del error de este modelo. La idea principal de este observador es la reconfiguración continua de la ganancia con la finalidad de reducir el error de estimación del modelo en cada instante, logrando así una mayor rapidez en la convergencia del observador hacia la respuesta real del sistema. El objetivo de este trabajo es comprobar la funcionalidad de este observador mediante la validación experimental, en línea, en un proceso de una planta piloto de destilación

Comparative voltammetric studies were performed between high purity pyrite mineral (98.86%) and arsenopyrite mineral (content of 85.96% arsenopyrite, FeAsS; 11.84% pyrite, FeS 2; 0.98% galena, PbS; 0.06% chalcopyrite, CuFeS 2) in order to analyze the galvanic effect on the electrochemical reactivity of two different mineralogical phases when these are associated in the same mineral, using carbon paste electrodes (CPE) in 0.1 M NaNO 3(pH 6.5) as electrolyte. Theoretical studies were performed for a more detailed analysis on the total energy and energy relative of a total optimization of the species involved in the pyrite and arsenopyrite oxidation as pure mineral. The results indicate that the electrochemical reactivity of pyrite in the arsenopyrite mineral was delayed and displaced to more positive potentials with respect to the high purity pyrite mineral electrochemical response, due to a galvanic effect. On the other hand, the voltammetric studies showed the oxidation stages of arsenopyrite mineral, indicating that arsenopyrite was oxidized in a first stage to Fe 2+, realgar (As 2S 2), H 3ASO 3, and S 0. In a second stage, the arsenopyrite and the pyrite were oxidized to FeOOH(s) and S 0, followed by oxidation of H 3AsO 3to H 2AsO 4−and S 0to SO 4−, besides the scorodite (FeSO 4·2H 2O) formation. Meanwhile, to more negative potentials the regeneration of FeAsS and the reduction to elemental arsenic do not occur due to the reduction of arsenate (H 2AsO 4−) to H 3AsO 3and the residual scorodite (FeAsO 4·2H 2O) that was not dissolved by chemical reaction. The analysis by scanning electron microscopy and energy dispersive spectrometer to surfaces of the electrodes with the mineral (CPE) modified electrochemically was carried out to support the reaction mechanisms.

The early detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the real-time quantitative polymerase chain reaction (RT-qPCR) as a gold-standard molecular tool has allowed to test and trace the viral spread and the isolation of COVID-19-infected patients. The detection capacity of viral and internal genes is an essential parameter to consider and analyze during the assay. In this study, we analyze the performance of the two commercial RT-qPCR kits used in Chile, TaqMan™ 2019-nCoV Control Kit v1 (Thermo Fisher) and MaxCov19 (TAAG Genetics), for the COVID-19 diagnosis from nasopharyngeal swab samples (NPSs). Our results show a lower sensitivity of the TAAG kit compared to the Thermo Fisher kit, even in the detection of SARS-CoV-2 mutations associated with its variants. This study reinforces the relevance of evaluating the performance of RT-qPCR kits before being used massively since those with lower sensitivity can generate false negatives and produce outbreaks of local infections.

The main aim of this study is to offer an easy and practical research model to guide the research activity of students and thereby reduce the syndrome of ABD (All but Dissertation) and, at the same time, make it easier for evaluators to visualize the development of research projects to guide students more efficiently. The Canvas model proposed by Osterwalder and Pigneur in 2011—for the formulation of business plans—has been the source of inspiration for the instrument proposed by the authors of this study. That model has been adjusted and reformulated by the researchers for the development, synthesis, and presentation of the research projects in the academic field, resulting in the proposal of the Canvas Model for Research Projects (CMRP). For developing this instrument, the researchers have mainly used a qualitative methodology, although part of the analysis and proposals reflected in this study come from a brief empirical trial carried out with a small group of students to validate the configuration and utility of the ten elements that make up the proposed model. The result—both the documentary review, which served as the basis for the combination and distribution of the components of the proposed model, and the brief trial carried out by the researchers—allowed us to observe, in a first approach, the usefulness of the instrument in the preparation of research projects and its utility as an evaluation tool of academic research projects.

The purpose of this study was to determine the effect of thiopentone anaesthesia on glucose metabolism. Blood sugar (BS), serum immunoreactive insulin (IRI) and serum non-esterified fatty acid (NEFA) concentrations were measured during the course of (1) an intravenous glucose tolerance test (IVGTT), and (2) an intravenous insulin test (ITT), in conscious and anaesthetized fasted dogs. The IVGTTs were repeated in dogs under alpha-or beta-adrenergic blockade, induced by phentolamine or propranolol. During the IVGTT, the anaesthetized dogs showed glucose intolerance (blood sugar levels were higher than in the control group) and little serum IRI response to hyperglycaemia was detected. An attenuated initial decrease and a slower rebound of NEFA concentration was observed in anaesthetized animals than in controls. Phentolamine administration (5 mg · kg−1iv) partly restored the IRI response without affecting the BS levels; propanolol (1 mg · kg−1iv) had no effect. Anaesthetized dogs showed a moderate resistance to insulin induced hypoglycaemic action and a lack of serum NEFA response during counter-regulation of hypoglycaemia, while in conscious controls an intense rebound was observed. Hyperinsulinaemia after iv insulin administration was longer in anaesthetized dogs than in controls. The insulin distribution space was 78% of body weight and insulin t1/2in blood group compared with 54% and 16 min, in controls. We conclude that thiopentone provokes disturbances in glucose and serum NEFA metabolisms and abolishes the serum IRI response to hyperglycaemia. These effects are influenced by extrapancreatic factors regulating serum IRI levels and by an alpha-adrenergic mechanism, via the inhibition of insulin secretion.

This study was done in an attempt to elucidate some of the properties of bovine IFNs. Maximum levels of both fibroblast and leukocyte IFNs occurred prior to 24 h whereas maximum levels of immune IFN were not reached until after 72 h. The latter species of IFN was unstable at either pH 2 or 56°C whereas both the fibroblast and leukocyte IFNs were more stable under these conditions. Studies of cross-species protection between fibroblast and leukocyte IFNs indicate that the former was more protective for other species than the latter.

Wild boars (Sus scrofa) were introduced in Mexico for sport hunting and meat trading for human consumption, but the available data regarding their role in pathogen transmission are limited. B e h a v i o u r a l p a t t e r n s o f f r e e r o a m i n g w i l d b o a r i n a s p a t i o t e m p o r a l c o n t e x t Erdtmann D. and O. Keuling 2020 PeerJ, https://doi.org/10.7717/peerj.10409 Although the almost worldwide distributed wild boar Sus scrofa is a well-studied species, little is known about the behaviour of autochthonous, free living wild boar in a spatiotemporal context which can help to better understand wild boar in conflict terms with humans and to find solutions. [Extracted from the article]