50 research outputs found
A comparative analysis of gamma and hadron families at the superhigh energies recorded in experiment Pamir
A comparative analysis of hadron and gamma families which have undergone the decascading procedure is made. Results are compared with different models of interactions. In hadron families with energies Summary E sub H sup gamma 20 TeV as well as in gamma families with energies Summary E sub gamma 70 TeV, increasing azimuthal anisotropy is observed
A Density Functional Theory and Laser Flash Photolysis Investigation of Carbofuran Photodegradation in Aqueous Medium
Density functional theory (DFT) approach was used to study the photodegradation of Carbofuran in aqueous medium. This computational method enables us to assign the electronic transitions and interpret the dissociative behavior upon irradiation based on a thermodynamical analysis of the bond dissociation energies (BDE) of Carbofuran. According to these calculations, phenoxy C---O bond appears weaker than the C---N bonds. Hence, it was predicted that the photodegradation of Carbofuran should occur with an initial homolytic dissociation of the C---O bond of the carbamate moiety. Laser Flash Photolysis (LFP) results clearly indicate the formation of the phenoxyl radical, which support the outcome of this theoretical approach
The Concept of Old Town Neighborhoods and Their Historical Formation
In this article, the structure and objects of the neighborhoods, as well as the fact that the neighborhood is a small administrative area, are associated with a common way of life, values, traditions and customs. It is said that the functions of the mahalla have changed at different stages of history due to political and social changes
Serendipitous Discovery of Light-Induced \u3cem\u3e(In Situ)\u3c/em\u3e Formation of An Azo-Bridged Dimeric Sulfonated Naphthol as a Potent PTP1B Inhibito
Background Protein tyrosine phosphatases (PTPs) like dual specificity phosphatase 5 (DUSP5) and protein tyrosine phosphatase 1B (PTP1B) are drug targets for diseases that include cancer, diabetes, and vascular disorders such as hemangiomas. The PTPs are also known to be notoriously difficult targets for designing inihibitors that become viable drug leads. Therefore, the pipeline for approved drugs in this class is minimal. Furthermore, drug screening for targets like PTPs often produce false positive and false negative results. Results Studies presented herein provide important insights into: (a) how to detect such artifacts, (b) the importance of compound re-synthesis and verification, and (c) how in situ chemical reactivity of compounds, when diagnosed and characterized, can actually lead to serendipitous discovery of valuable new lead molecules. Initial docking of compounds from the National Cancer Institute (NCI), followed by experimental testing in enzyme inhibition assays, identified an inhibitor of DUSP5. Subsequent control experiments revealed that this compound demonstrated time-dependent inhibition, and also a time-dependent change in color of the inhibitor that correlated with potency of inhibition. In addition, the compound activity varied depending on vendor source. We hypothesized, and then confirmed by synthesis of the compound, that the actual inhibitor of DUSP5 was a dimeric form of the original inhibitor compound, formed upon exposure to light and oxygen. This compound has an IC50 of 36 μM for DUSP5, and is a competitive inhibitor. Testing against PTP1B, for selectivity, demonstrated the dimeric compound was actually a more potent inhibitor of PTP1B, with an IC50 of 2.1 μM. The compound, an azo-bridged dimer of sulfonated naphthol rings, resembles previously reported PTP inhibitors, but with 18-fold selectivity for PTP1B versus DUSP5. Conclusion We report the identification of a potent PTP1B inhibitor that was initially identified in a screen for DUSP5, implying common mechanism of inhibitory action for these scaffolds
Роль метилирования генов микроРНК в различных молекулярно-биологических подтипах рака молочной железы
The methylation of CpG islands in the promoter regions of miRNA genes is an epigenetic modification that plays a decisive role in the breast cancer (BC) initiation and progression. The aim of the study was to investigate the frequency of 5 miRNA genes methylation (miRNA-9–1, miRNA-9–3, miRNA-34b/c, miRNA-193A, miRNA-129-2) in mammary epithelial neoplasms. Methylation-specific polymerase chain reaction (MS-PCR) was used to detect methylated genes. 62 patients took part in this study. It was found that the frequency of all 5 miRNAs genes methylation is significantly higher in tumor tissue than in the adjacent histologically unchanged mammary tissue. The authors also performed a correlation analysis and founded a relationship between the methylation rate of certain miRNA genes with some clinical and molecular characteristics of the tumor. This information on epigenetic disorders of BC complements the “molecular portrait” of the tumor and can be used to diagnose and assess the prognosis.Метилирование промоторных CpG-островков генов микроРНК (миРНК) при раке молочной железы (РМЖ) – эпигенетическая модификация, которая играет решающую роль в инициировании и прогрессировании заболевания. В данной статье представлено исследование, цель которого – изучить частоту метилирования пяти генов миРНК (миРНК-9–1, миРНК- 9–3, миРНК-34b/c, миРНК-193a, миРНК-129-2) в эпителиальных опухолях молочной железы. Для выявления метилированных генов использовался метод полимеразной цепной реакции, специфичной к метилированному аллелю (МС-ПЦР). В исследовании приняли участие 62 пациентки. Оказалось, что частота метилирования генов всех пяти миРНК достоверно выше в опухолевой ткани, чем в прилежащей гистологически неизмененной ткани молочных желез. Авторы также провели корреляционный анализ и выявили связь частоты метилирования определенных генов миРНК с некоторыми клиническими и молекулярными характеристиками опухоли. Полученные данные об эпигенетических нарушениях при РМЖ дополняют «молекулярный портрет» опухоли и являются перспективными маркерами для диагностики и оценки прогноза, а также могут стать мишенью для успешной терапии
Desoxyhemigossypol 6-methyl ether
The title sesquiterpene [systematic name: 6-methoxy-10-methyl-7-(propan-2-yl)-2-oxatricyclo[6.3.1.04,12]dodeca-1(11),4,6,8(12),9-pentaen-5-ol], C16H18O3, was isolated from pathogen-infected stele tissue of Gossypium barbadense. There are two molecules in the asymmetric unit and the dihedral angle between their naphthofuran systems is 86.48 (2)°. In the crystal, O—H...O hydrogen bonds between the hydroxy groups and etheric O atoms link the molecules into centrosymmetric tetramers. These tetramers are assembled into (010) layers via stacking interactions between the naphthofuran systems [interplanar distance 3.473 (3) Å] and short C—H...O contacts
Lacinilene C 7-methyl ether
The title compound, C16H20O3 [systematic name: 1-hydroxy-7-methoxy-1,6-dimethyl-4-(propan-2-yl)naphthalen-2(1H)-one], is a sesquiterpene isolated from foliar tissues of the cotton plant and is of interest with respect to its antibacterial properties. Its phenyl ring is ideally planar, and the maximum of deviation in the second ring is 0.386 (3) Å. The hydroxy group and the methyl group are oriented in an equatorial fashion and axial, respectively, to the second ring. In the crystal, inversion dimers are formed through pairs of O—H...O hydrogen bonds. Weak C—H...O hydrogen bonds link the dimers into columns along the c axis. These columns form a crystal structure with a crystal packing factor of 0.66
Investigation of catalytic hydrogen sensors with platinum group catalysts
Environmental deterioration and limited resources of hydrocarbons push the development of alternative power sources. One of the most promising energy carriers is hydrogen. However, handling hydrogen is more hazardous than the use of hydrocarbons because it has a significantly wider flammable range. Thus the development of new sensors for preventing hydrogen leakage is the actual task of modern materials science and chemical engineering. In this work, the response of catalytic sensors to hydrogen with different catalysts of platinum group (Pt, Pd, Ir, Rh, Pt+Pd, Pt+Pd+Rh, Pt+Pd+Ir) in the pre-explosion concentration range is studied. Temperature dependencies of sensitivity are discussed. A hysteresis in sensor response is observed during the cycling of the supply voltage. This phenomenon can be explained by partial transformation of platinum group metal oxides into metallic phase at a temperature of more than 500 C and reverse metal oxidation at temperatures less than 400 C. It has been shown that the sensors with catalysts containing Ir and Rh demonstrate more preferable characteristics for practical applications.