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[en] On the basis of the separated form factors method (SFF), the analysis of data on the small-angle neutron scattering (SANS) on polydispersed population of unilamellar vesicles of dipalmitoylphosphatidylcholine (DPPC) in heavy water with dimethyl sulfoxide (DMSO) is carried out. It is shown that the growth of DMSO molar fraction in water from 0 to 15% leads to increase of thickness of the bilayer to values of the repeat distance of multilamellar membranes of DPPC, which means a dehydration of the intermembrane space and steric contact of the neighbor bilayers of DPPC at a DMSO molar fraction of 15%.
[ru]На основе метода разделенных формфакторов проведен анализ спектров малоуглового рассеяния нейтронов на полидисперсной популяции однослойных везикул дипальмитоилфосфатидилхолина (ДПФХ) в тяжелой воде с добавлением диметилсульфоксида (ДМСО). Показано, что рост мольной доли ДМСО в воде от 0 до 15% приводит к увеличению толщины бислоя до характерных значений периода повторяемости многослойных мембран ДПФХ, что свидетельствует о дегидратации межмембранного пространства и стерическом контакте соседних бислоев ДПФХ при мольной доле ДМСО 15%.
[en] Primary and secondary kinetic hydrogen isotope effects in the elimination of toluene from the alkoxide of 1,2,3-triphenylpropan-2-ol have been determined and are consistent with rate limiting proton transfer in gas phase reaction and with rate limiting carbon-carbon bond cleavage in reaction in dimethyl sulphoxide (DMSO) solution. (author)
[en] The synthesis of several macrocyclic ligands, designed by a computer modeling approach for the complexation of the uranyl ion, has now been completed and their structures established. Preliminary indicate that these macrocycles successfully complex the uranyl ion. Other synthetic efforts have led to a variety of intermediates suitable for final ring closure to the desired macrocycles, providing appreciable potential for variation of the macrocyclic peripheral atoms. A 1:1-uranyl ion complex of one of these precursor products has been shown to undergo a DMSO-induced rearrangement to a 2:1 uranyl ion to ligand complex, both structures having been established by single crystal x-ray data. 10 refs
[en] To identify peptides bioactivity, 2 di- and 4 tripeptides containing a non-protein amino acid (S)-α-allylglycine (2-aminopent-4-enovic acid) were synthesized. Microbiological studies have revealed that N-tert-butyloxycarbonyl-(S)-alanyl-(S)-)-α-allylglycine, N-tert-butyloxycarbonyl-(S)-alanyl-(S)-)-α-allylglycylglycine, N-tert-butyloxycarbonyl-(S)-alanyl-(S)-)-α-allylglycyl-(S)-alanine peptides suppress the growth of gram negative: E. coli, C. freundii, S. marcesens, S. typhimurinum, Erwinia sp., P. putida and gram positive B. flavum, B. lactofermentum, B. subtilis strains. The studied peptide N-tert-butyloxycarbonylglycyl-(S)-)-α-allylglycyl glycine is an inhibitor of the branched-chain amino acid aminotransferases
[en] When a molecule with two equivalent chemical bonds is excited above the threshold for dissociation of both bonds, how the rupture of the two bonds is temporally coupled becomes a salient question. Following absorption at 193 nm dimethyl sulfoxide (CH3SOCH3) contains enough energy to rupture both C-S bonds. This can happen in a stepwise (reaction 1) or concerted (reaction 2) fashion where the authors use rotation of the SOCH3 intermediate prior to dissociation to define a stepwise dissociation: (1) CH3SOCH3 → 2CH3 + SO; (2a) CH3SOCH3 → CH3 + SOCH3; and (2b) SOCH3 → SO + CH3. Recently, the dissociation of dimethyl sulfoxide following absorption at 193 nm was suggested to involve simultaneous cleavage of both C-S bonds on an excited electronic surface. This conclusion was inferred from laser induced fluorescence (LIF) and resonant multiphoton ionization (2+1 REMPI) measurements of the internal energy content in the CH3 and SO photoproducts and a near unity quantum yield measured for SO. Since this type of concerted three body dissociation is very interesting and a rather rare event in photodissociation dynamics, the authors chose to investigate this system using the technique of photofragment translational spectroscopy at beamline 22.214.171.124. The soft photoionization provided by the VUV undulator radiation allowed the authors to probe the SOCH3 intermediate which had not been previously observed and provided good evidence that the dissociation of dimethyl sulfoxide primarily proceeds via a two step dissociation, reaction 2
[en] Highlights: ► We identified the inhibitory effect of ISL on cell proliferation of LCLs. ► We found ISL-induced genes and miRNAs through microarray approach. ► ISL-treated LCLs represented gene expression changes in cell cycle and p53 pathway. ► We revealed 12 putative mRNA–miRNA functional pairs associated with ISL effect. -- Abstract: Isoliquiritigenin (ISL) has been known to induce cell cycle arrest and apoptosis of various cancer cells. However, genetic factors regulating ISL effects remain unclear. The aim of this study was to identify the molecular signatures involved in ISL-induced cell death of EBV-transformed lymphoblastoid cell lines (LCLs) using microarray analyses. For gene expression and microRNA (miRNA) microarray experiments, each of 12 LCL strains was independently treated with ISL or DMSO as a vehicle control for a day prior to total RNA extraction. ISL treatment inhibited cell proliferation of LCLs in a dose-dependent manner. Microarray analysis showed that ISL-treated LCLs represented gene expression changes in cell cycle and p53 signaling pathway, having a potential as regulators in LCL survival and sensitivity to ISL-induced cytotoxicity. In addition, 36 miRNAs including five miRNAs with unknown functions were differentially expressed in ISL-treated LCLs. The integrative analysis of miRNA and gene expression profiles revealed 12 putative mRNA–miRNA functional pairs. Among them, miR-1207-5p and miR-575 were negatively correlated with p53 pathway- and cell cycle-associated genes, respectively. In conclusion, our study suggests that miRNAs play an important role in ISL-induced cytotoxicity in LCLs by targeting signaling pathways including p53 pathway and cell cycle.
[en] A series of derivatives of symmetrical 1,3-dichloro-1,1,3,3-tetraorganyl- and 1,1,3,3-tetrachloro-1,3-diorganyldisiloxanes ClRR’Si-O-SiRR’ (R = Cl, H, CH 3; R’ = CH 3, Et, ClCH 2, Vin, Ph) have been synthesized by a novel efficient reaction of corresponding diorganyldichlorosilane and organyltrichlorosilane RSiCl 3 (3–5-fold excess) with dimethyl sulfoxide in 53 to 91 % yield. .
[en] The authors describe an improved lateral flow assay based on (a) the use of catalytic hairpin assembly (CHA), and (b) on signal amplification performed at the interface of gold nanoparticles (AuNPs). The combination of the amplification capability of the CHA reaction and the unique optical properties of AuNPs results in an assay that has a sensitivity that is improved by more than two orders of magnitude. MicroRNA-21 was employed as a model analyte to prove the concept. The presence of microRNA-21 triggers the self-assembly of two hairpin DNAs into double stranded DNA and exposing biotin molecules on the surface of AuNPs. Hence, the target becomes recycled and the signal is strongly amplified. The AuNPs carrying biotin are captured on the test line of the strip to display a red zone. This enables the visual recognition of microRNA without the need for any instrumentation. The fast quantitation of microRNA via the red band intensity is accomplished with the help of software, and the limit of detection is 0.89 pM. The enhanced lateral flow assay was employed to the determination of microRNA-21 in cell extracts and spiked serum samples. .