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Fluorescence-based oligonucleotide probes have a great importance in research of molecular interactions. Molecular beacons (MBs) are special case of fluorescent probes that form a stem-loop shape, bringing together a fluorophore and quencher, thus emitting fluorescence only when hybridized to a complementary target. Here we describe a new method for the quantitation of MB hybridization based on the measurement of changes in free energy instead of the fluorescence intensity. The MB energy state can be measured by micro-fluorescence detection. The approach allowed to determine hybridization energy of the MB with target nucleotide directly from fluorescence spectra and distinguish the MB in unfolded and hybridized states. Moreover, the method enabled us to discriminate between DNA duplexes with perfect complementarity or a single-nucleotide mismatch, based on the first direct experimental prove of enthalpy-entropy compensation.

A large number of galaxies have large-scale magnetic fields which are usually measured by the Faraday rotation of radio waves. Their origin is usually connected with the dynamo mechanism which is based on differential rotation of the interstellar medium and alpha-effect characterizing the helicity of the small-scale motions. However, it is necessary to have initial magnetic field which cannot be generated by the dynamo. One of the possible mechanisms is connected with the Biermann battery which acts because of different masses of protons and electrons passing from the central object. They produce circular currents which induce the vertical magnetic field. As for this field we can obtain the integral equation which can be solved by simulated annealing method which is widely used in different branches of mathematics

Coil springs in motorcycles are crucial components in the vehicle's suspension system, where they are used in the front or rear to absorb the impact energy experienced by the wheels. In this study, the coil spring experienced a failure in the form of fracture, prompting several tests to analyze the mechanism and causes of this failure. The conducted tests include visual observation, chemical composition testing, metallographic testing, hardness testing, and FEM simulation. The visual observation results indicate that the failure experienced by the coil spring is due to fatigue fracture, as defined by the presence of crack initiation, crack propagation (beachmark), and final rupture. The chemical composition testing reveals that the material used is SAE 9254 Steel, that is a low-alloy steel. The microstructure formed consisted of ferrite and pearlite phases, attributed to the absence of quenching and tempering processes during the coil spring's production. The hardness testing results show an average hardness of 216,6 HV, confirming the absence of quenching and tempering in the coil spring production process. The FEM simulation results show that the stress does not exceed the yield strength of the material. [ABSTRACT FROM AUTHOR]

In this work, Ce- and Li-doped CaF2 phosphor (CaF2:Ce,Li) was synthesized by the combustion technique. Structural and morphological analysis of the synthesized material has been carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD pattern reveals the formation of a pure phase of the CaF2 crystal with a crystallite size of 717 nm. The luminescence properties were investigated by the thermoluminescence (TL) technique. The effect of sintering temperature on the TL glow curve of the pellets has been investigated for different temperatures (450, 500, 525, 550, and 575 °C). Pellets sintered at 525 °C and 550 °C presented higher sensitivity in their TL responses for gamma and UV irradiation, respectively. Samples irradiated with gamma radiation show two intense TL peaks centered at 172 °C and 275 °C. On the other hand, samples irradiated with UV radiation show two peaks centered at 195 and 280 °C. The intensity of the TL peaks increases with gamma radiation dose and UV irradiation time. The kinetic parameters of the glow curve peaks were determined through the combined analysis of the results obtained by the Tm-Tstop and deconvolution methods. [ABSTRACT FROM AUTHOR]

Fluorescence-based oligonucleotide probes have a great importance in research of molecular interactions. Molecular beacons (MBs) are special case of fluorescent probes that form a stem-loop shape, bringing together a fluorophore and quencher, thus emitting fluorescence only when hybridized to a complementary target. Here we describe a new method for the quantitation of MB hybridization based on the measurement of changes in free energy instead of the fluorescence intensity. The MB energy state can be measured by micro-fluorescence detection. The approach allowed to determine hybridization energy of the MB with target nucleotide directly from fluorescence spectra and distinguish the MB in unfolded and hybridized states. Moreover, the method enabled us to discriminate between DNA duplexes with perfect complementarity or a single-nucleotide mismatch, based on the first direct experimental prove of enthalpy-entropy compensation. [ABSTRACT FROM AUTHOR]

Nucleobase building blocks have been demonstrated to be strong candidates when it comes to DNA/RNA-like materials by benefiting from hydrogen bond interactions as physical properties. Modifying at the 5′ position is the simplest way to develop nucleobase-based structures by transesterification using the lipase Novozym 435. Herein, we describe the optimization of the lipase-catalyzed synthesis of the monomer 5′-O-methacryloylcytidine with the assistance of microwave irradiation. Variable reaction parameters, such as enzyme concentration, molar ratio of the substrate, reaction temperature and reaction time, were investigated to find the optimum reaction condition in terms of obtaining the highest yield.

La miocardiopatía o displasia arritmogénica del ventrículo derecho es una cardiopatía de origen genético cuyo diagnóstico supone, a menudo, un reto para el clínico. Es una de las causas más comunes de muerte súbita cardíaca en la adolescencia y en los adultos jóvenes. Se presenta el caso de un paciente con historia de arritmias ventriculares malignas y de muerte súbita cardíaca recuperada, por displasia arritmogénica del ventrículo derecho, con fragmentación del QRS en las derivaciones precordiales derechas, como marcador de la presencia de un sustrato propicio para el surgimiento de la fibrilación ventricular espontánea. Se comenta la patogenia, el diagnóstico y el tratamiento de esta enfermedad.

Abstract Chimeric antigen receptor (CAR) T cells brought substantial benefit to patients with B‐cell malignancies. Notwithstanding, CAR T‐cell manufacturing requires complex procedures impeding the broad supply chain. Here, we provide evidence that human CD19‐CAR T cells can be generated directly in vivo using the lentiviral vector CD8‐LV specifically targeting human CD8+ cells. Administration into mice xenografted with Raji lymphoma cells and human peripheral blood mononuclear cells led to CAR expression solely in CD8+ T cells and efficacious elimination of CD19+ B cells. Further, upon injection of CD8‐LV into mice transplanted with human CD34+ cells, induction of CAR T cells and CD19+ B‐cell depletion was observed in 7 out of 10 treated animals. Notably, three mice showed elevated levels of human cytokines in plasma. Tissue‐invading CAR T cells and complete elimination of the B‐lymphocyte‐rich zones in spleen were indicative of a cytokine release syndrome. Our data demonstrate the feasibility of in vivo reprogramming of human CD8+ CAR T cells active against CD19+ cells, yet with similar adverse effects currently notorious in the clinical practice.