RESUMO
Molecular genetic analysis of polymorphic variants of serotonin receptor genes (HTR2C and HTR2A) was performed in 89 healthy medical students and regulatory and adaptive capacities were determined by cardiorespiratory synchronism. The relationship of serotonin receptor gene polymorphisms and the regulatory and adaptive capabilities of the body were revealed. The highly active *G allele and *G/*G genotype of the serotonin receptor HTR2C gene and the heterozygous *A/*G genotype of the serotonin receptor HTR2A gene are associated with "good" regulatory and adaptive capacities. The low-active *C allele of the serotonin receptor HTR2C gene is associated with "low" regulatory and adaptive capacities.
Assuntos
Estudantes de Medicina , Humanos , Polimorfismo Genético/genética , Genótipo , Receptores de Serotonina , Alelos , Receptor 5-HT2A de Serotonina/genética , Polimorfismo de Nucleotídeo Único/genética , Receptor 5-HT2C de Serotonina/genéticaRESUMO
In nodal-line semimetals, linearly dispersing states form Dirac loops in the reciprocal space with a high degree of electron-hole symmetry and a reduced density of states near the Fermi level. The result is reduced electronic screening and enhanced correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time- and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT+U+V) and by time-dependent DFT+U+V. We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.
RESUMO
Lead-halide perovskite (LHP) semiconductors are emergent optoelectronic materials with outstanding transport properties which are not yet fully understood. We find signatures of large polaron formation in the electronic structure of the inorganic LHP CsPbBr_{3} by means of angle-resolved photoelectron spectroscopy. The experimental valence band dispersion shows a hole effective mass of 0.26±0.02 m_{e}, 50% heavier than the bare mass m_{0}=0.17 m_{e} predicted by density functional theory. Calculations of the electron-phonon coupling indicate that phonon dressing of the carriers mainly occurs via distortions of the Pb-Br bond with a Fröhlich coupling parameter α=1.81. A good agreement with our experimental data is obtained within the Feynman polaron model, validating a viable theoretical method to predict the carrier effective mass of LHPs ab initio.
RESUMO
Trigonal tellurium, a small-gap semiconductor with pronounced magneto-electric and magneto-optical responses, is among the simplest realizations of a chiral crystal. We have studied by spin- and angle-resolved photoelectron spectroscopy its unconventional electronic structure and unique spin texture. We identify Kramers-Weyl, composite, and accordionlike Weyl fermions, so far only predicted by theory, and show that the spin polarization is parallel to the wave vector along the lines in k space connecting high-symmetry points. Our results clarify the symmetries that enforce such spin texture in a chiral crystal, thus bringing new insight in the formation of a spin vectorial field more complex than the previously proposed hedgehog configuration. Our findings thus pave the way to a classification scheme for these exotic spin textures and their search in chiral crystals.
RESUMO
The indicators of pro- and antioxidant systems in sperm and sperm plasma of breeding boars of Large White breed and SS23 synthetic line were studied. Measurements of antioxidant enzyme activity, determination of lipid peroxidation (LPO) product content, and antioxidant factor were performed. Lipid peroxidation in the semen of healthy breeding boars was characterized by a stable level of activity, which is necessary to ensure normal reproductive functions. Additionally, there was a high content of low molecular weight thiols and proteins. The concentration of SH-groups in spermatozoa was higher (P≤0.05) compared to sperm plasma. The number of total, protein, and free SH-groups in the semen of boars of the synthetic line was higher (P<0.05) in relation to animals of the Large White breed. Low catalase (CAT) activity in the sperm was compensated by glutathione peroxidase (GPX). The content of ceruloplasmin (CP) in the sperm of boars was almost twice as high as that of sperm plasma. In spermatozoa, high content of reduced glutathione (GTH) was recorded, which was more than 3 times higher than in the seminal fluid. The main antioxidants of spermatozoa were superoxide dismutase (SOD), CP, SH-groups of proteins, and reduced content of GTH. We revealed that CAT is a key enzyme that neutralizes excess hydrogen peroxide in boar semen. In contrast, in sperm, hydrogen peroxide was inactivated mainly by GPX. Further research on the mechanisms of action of reactive oxygen species on boar semen will help to develop effective methods for sperm storage and successful fertilization of oocytes.
Assuntos
Antioxidantes , Peróxido de Hidrogênio , Espermatozoides , Animais , Antioxidantes/metabolismo , Cruzamento , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Masculino , Espécies Reativas de Oxigênio , Espermatozoides/metabolismo , SuínosRESUMO
This study reports for the first time temporal trends for the period of 2011-2016 in 137Cs content in cow's milk originating from private farms and households of 14 settlements located in the territories of the Rivne region, Ukraine. These areas are still radioactively contaminated as a result of the accident at the Chernobyl Nuclear Power Plant (ChNPP) in 1986. In 2016, the average 137Cs activity concentration in milk exceeded the Ukrainian Permissible Level (PL) for adults of 100â¯Bq/l in samples from 6 settlements and the PL for children of 40â¯Bq/l in 8 settlements, reaching activity concentration of around 500â¯Bq/l in some samples. Estimated annual effective doses calculated utilizing two different methodologies were in the range of 1.4-2.6â¯mSv/year and 1.2-1.8â¯mSv/year, respectively. The estimated effective period of milk semi-purification (T1/2_eff) from 137Cs in these settlements was in the range from 8 to 17â¯years. The estimated ecological period of milk semi-purification (T1/2_eco) from 137Cs was in the range from 11 to 36â¯years. The optimization of the remedial actions strategy for investigated settlements exposed to an effective dose above 1â¯mSv/year (as estimated in 2016) has shown that a diversity of measures can decrease effective dose for a representative person to below 1â¯mSv/year. Such measures include application of Ferrocyn to cows, mineral fertilization of potato fields, information campaigns on consumption of wild mushrooms and other forestry products, and feeding pigs with uncontaminated fodder. The total costs of such measures are estimated to be about 71,000 Euro per year for the combined population (8336 inhabitants) of the six villages investigated in this study that showed the highest median residual 137Cs activity concentrations in milk, with a subsequent decrease in cost in the future. This would result in an averted collective dose of 11 man-Sv, at an average cost of 6.5â¯kEuro/man-Sv averted. In the absence of governmental programs for implementation of necessary protective measures to reduce radiological risks to impacted populations, the exceedance of PL for the activity concentration of 137Cs in cow's milk for adults of 100â¯Bq/l in the Chernobyl-affected areas of Ukraine could persist for many more years - until at least 2040.
Assuntos
Radioisótopos de Césio , Acidente Nuclear de Chernobyl , Exposição Dietética/análise , Poluentes Radioativos do Solo/análise , Animais , Bovinos , Radioisótopos de Césio/análise , Radioisótopos de Césio/toxicidade , Humanos , Leite/química , UcrâniaRESUMO
Immunoblotting as well as enzyme assays demonstrate the presence of the self-glucosylating protein, glycogenin, in the protein-glycogen complex, in the sarcoplasmic reticulum and in phosphorylase kinase. In all three compartments glycogenin occurs in different, albeit, defined glucosylated forms, which upon deglucosylation are converted into a 42 kDa form. We suggest that phosphorylase kinase might have a dual function in glycogen biogenesis: firstly, control of glycogen degradation in the protein-glycogen complex via phosphorylation of glycogen phosphorylase b; secondly, regulation of glycogen biosynthesis on the sarcoplasmic reticular membranes via phosphorylation and thereby inhibition of glycogen synthase.
Assuntos
Glicogênio/biossíntese , Glicoproteínas/metabolismo , Músculo Esquelético/metabolismo , Fosforilase Quinase/metabolismo , Animais , Glucose/metabolismo , Glucosiltransferases , Glicogênio/química , Glicogênio Sintase/metabolismo , Glicoproteínas/análise , Glicoproteínas/química , Glicosilação , Peso Molecular , Músculo Esquelético/enzimologia , Fosforilase Quinase/química , Fosforilase b/metabolismo , Coelhos , Retículo Sarcoplasmático/química , Retículo Sarcoplasmático/enzimologiaRESUMO
Immunoglobulin G characteristic of malignant growth is studied for its effect on glycolysis in a dialyzed enzymic preparation from the rabbit muscles. A peptide-nature compound participating in immunoglobulin G activation of glycolysis is shown to transfer to dialysate in the process of the enzyme dialysis. The activation may involve cAMP, ADP, NADH.
Assuntos
Glicólise/efeitos dos fármacos , Imunoglobulina G/farmacologia , Neoplasias/sangue , Difosfato de Adenosina/metabolismo , Animais , Fenômenos Químicos , Química , AMP Cíclico/metabolismo , Humanos , Técnicas In Vitro , NAD/metabolismo , Coelhos , Estimulação QuímicaRESUMO
Clinical observations over 130 patients with burnt conchae of the auricle allowed the injuries to be subdivided into two groups: primary and secondary lesions. Primary lesions are associated with the direct effect of the thermal factor upon the concha of the auricle while secondary lesions are related to infectious complications of burns. The classification of thermal lesions presented here may help provide adequate and timely therapy. When treating burns of conchae of the auricle, it is important to prevent burn dissemination and suppuration of the wound.
Assuntos
Queimaduras/complicações , Orelha Externa/lesões , Queimaduras/terapia , Humanos , Infecção dos Ferimentos/prevenção & controleAssuntos
Colagogos e Coleréticos/farmacologia , Complexo Vitamínico B/farmacologia , Administração Oral , Animais , Atropina/farmacologia , Bile/efeitos dos fármacos , Ácidos e Sais Biliares/análise , Bilirrubina/análise , Colesterol/análise , Cães , Fígado/metabolismo , Comprimidos , Fatores de TempoRESUMO
Blood serum of oncologic patients due to immunoglobulin involved in its composition, activates glycolysis in the soluble fraction of muscles when using starch, glycogen and glucose as substrates. The activation is registered under both aerobic and anaerobic conditions. When elucidating the immunoglobulin effect in a glycolytic chain under aerobic conditions it is shown that its activating effect in the incomplete incubation system is manifested with such glycolysis substrates as fructose-6-phosphate and 2-phosphoglyceric acid. Glycolysis activation with serum is insignificant or absent at all with the presence of glucose-6-phosphate, fructose-1,6-diphosphate, 3-phosphoglyceric aldehide, 3-phosphoglyceric acid, phosphoenolpyruvic acid, sodium pyruvate. Immunoglobulin isolated from the blood serum of oncologic patients does not affect the activity of purified preparations of hexokinase, glycerinaldehydephosphate dehydrogenase, lactate dehydrogenase under aerobic and anaerobic conditions. When using the air as a gas medium lactate dehydrogenase is activated by immunoglobulin. Lactate dehydrogenase activity under aerobic and anaerobic conditions is essentially lower than in the case when the air serves as a gas medium.
Assuntos
Glicólise , Imunoglobulinas/metabolismo , Neoplasias/imunologia , Aerobiose , Anaerobiose , Ativação Enzimática , Humanos , Cinética , L-Lactato Desidrogenase/metabolismo , Músculos/enzimologiaRESUMO
On the basis of observation of 239 sufferers with burns of the ear auricles and analysis of clinical data, the authors have suggested a classification of such lesions. Primary lesions are associated with a direct influence of the thermal factor on the ear auricle tissues, and the secondary ones--with addition of infection. In treatment of the sufferers with burns of the ear auricles one should aim at prevention of the deepening of the burns and suppuration of a burn wound.
Assuntos
Queimaduras , Orelha Externa/lesões , Queimaduras/classificação , Queimaduras/diagnóstico , Queimaduras/terapia , HumanosRESUMO
Cellular and humoral immunity was studied in 300 patients with acute appendicitis at the age of from 1 to 14 years. In all the patients, the secondary immunodeficient state was documented, which was the most pronounced at day 3 after the operation. In children after appendectomy, the inclusion into the complex of measures of the preparations increasing the immunologic reactivity of an organism is indicated.