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21.
Anjos JC Appel JA Bean A Bediaga I Bracker SB Browder TE Cremaldi LM Duboscq JE Elliot JR Escobar CO Gibney MC Hartner GF Karchin PE Kumar BR Lima JG Losty MJ Luste GJ Mantsch PM Martin JF McHugh S Menary SR Morrison RJ Nash T Pinfold J Punkar G Purohit MV Ross WR Santoro AF Sliwa K Sokoloff MD Souza MH Spalding WJ Streetman ME Stundzia AB Witherell MS 《Physical review letters》1992,69(20):2892-2895
22.
Jesús Emmanuel Solís‐Prez Jos Francisco Gmez‐Aguilar Lizeth Torres Ricardo Fabricio Escobar‐Jimnez Juan Reyes‐Reyes 《Mathematical Methods in the Applied Sciences》2019,42(18):7335-7348
In this work, the design of spectral observers for signal reconstruction based on Kalman filters is performed and evaluated. The conformable derivative and the beta‐derivative were used to design the Kalman filters. Both derivatives satisfy the same formulas of the classical derivation, eg, the chain rule. The derivative order, the Ricatti equation parameters, and the observers tuning parameters were optimized using an optimization algorithm based on the bat's echolocation behavior (Bat algorithm). The simulation results showed the advantages of using the proposed observers for the signal reconstruction. 相似文献
23.
Elisabeth Siebert Marius Horch Yvonne Rippers Johannes Fritsch Stefan Frielingsdorf Oliver Lenz Francisco VelazquezEscobar Friedrich Siebert Lars Paasche Uwe Kuhlmann Friedhelm Lendzian Maria‐Andrea Mroginski Ingo Zebger Peter Hildebrandt 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2013,125(19):5267-5270
24.
Claudio Parra Patricio Muoz Luis Bustos Felipe Parra Mario J. Simirgiotis Hugo Escobar 《Molecules (Basel, Switzerland)》2021,26(7)
The Lamiaceae family is an important source of species among medicinal plants highly valued for their biological properties and numerous uses in folk medicine. Origanum is one of the main genera that belong to this family. The purpose of the study was to determine the phenolic composition of the Origanum vulgare extract and evaluate the antimicrobial, antioxidant, and inhibitory activities of this species that grows in the Andean region of the Atacama Desert. High-performance liquid chromatography was performed to determine the main phenols. Rosmarinic acid was identified as the predominant phenolic compound in this species (76.01 mg/100 g DW), followed by protocatechuic acid, which to our knowledge, no previous study reported similar concentrations in O. vulgare. The oregano extract exhibited a content of total phenolic (3948 mg GAE/100 g DW) and total flavonoid (593 mg QE/100 g DW) with a higher DPPH antioxidant activity (IC50 = 40.58 µg/mL), compared to the same species grown under other conditions. Furthermore, it was found to inhibit α-glucosidase activity with an IC50 value (7.11 mg/mL) lower than acarbose (129.32 mg/mL). Pseudomonas syringae and Pantoea agglomerans (both MIC 0.313 mg/mL and MBC 1.25 mg/mL) were the bacteria most susceptible to oregano extract with the lowest concentration necessary to inhibit bacterial growth. These results open the door for the potential use of this plant to manage chronic diseases, and they expand the knowledge of the species cultivated in arid environmental conditions. 相似文献
25.
Phytochromes are ubiquitous photoreceptors found in plants, eukaryotic algae, bacteria and fungi. Particularly, when bacteriophytochrome is irradiated with light, a Z‐to‐E (photo)isomerization takes place in the biliverdin chromophore as part of the Pr‐to‐Pfr conversion. This photoisomerization is concomitant with a bathochromic shift in the Q‐band. Based on experimental evidence, we studied a possible keto–enol tautomerization of BV, as an alternative reaction channel after its photoisomerization. In this contribution, the noncatalyzed and water‐assisted reaction pathways for the lactam–lactim interconversion through consecutive keto–enol tautomerization of a model BV species were studied deeply. It was found that in the absence of water molecules, the proton transfer reaction is unable to take place at normal conditions, due to large activation energies, and the endothermic formation of lactim derivatives prevents its occurrence. However, when a water molecule assists the process by catalyzing the proton transfer reaction, the activation free energy lowers considerably. The drastic lowering in the activation energy for the keto–enol tautomerism is due to the stabilization of the water moiety through hydrogen bonds along the reaction coordinate. The absorption spectra were computed for all tautomers. It was found that the UV–visible absorption bands are in reasonable agreement with the experimental data. Our results suggest that although the keto–enol equilibrium is likely favoring the lactam tautomer, the equilibrium could eventually be shifted in favor of the lactim, as it has been reported to occur in the dark reversion mechanism of bathy phytochromes. 相似文献
26.
Mattson M Alkhazov G Atamantchouk AG Balatz MY Bondar NF Cooper PS Dauwe LJ Davidenko GV Dersch U Dolgolenko AG Dzyubenko GB Edelstein R Emediato L Endler AM Engelfried J Eschrich I Escobar CO Evdokimov AV Filimonov IS Garcia FG Gaspero M Giller I Golovtsov VL Gouffon P Gülmez E Kangling H Iori M Jun SY Kaya M Kilmer J Kim VT Kochenda LM Konorov I Kozhevnikov AP Krivshich AG Krüger H Kubantsev MA Kubarovsky VP Kulyavtsev AI Kuropatkin NP Kurshetsov VF Kushnirenko A Kwan S Lach J Lamberto A 《Physical review letters》2002,89(11):112001
We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.1+/-0.5 events, a statistical significance of 6.3sigma. The observed mass of this state is 3519+/-1 MeV/c(2). The Gaussian mass width of this state is 3 MeV/c(2), consistent with resolution; its lifetime is less than 33 fs at 90% confidence. 相似文献
27.
Raman spectroscopy has been applied to the analytical determination of inosine nucleoside in nucleotides. Spectral characteristics of aqueous solutions of lithium, potassium and magnesium salts of inosine 5'-monophosphoric acid are described. Two characteristic bands located at 1553 and 1593 cm(-1) whose frequencies are not sensitive either to the nucleotide concentration or to alkaline cations present in the medium, have been used for this purpose. The concentration ranges over which the method was applicable were 2.5-80 and 11.5-80 mg ml(-1) of inosine using the 1553 and 1593 cm(-1) bands, respectively, with relative standard deviations of 2.5 and 4.0% and detection limits of 0.25 and 1.16% (w/w). As the above bands are not generated by the standard nucleobases, this method can be applied to the quantitative determination of inosine in transfer ribonucleic acids. 相似文献
28.
Raman Spectra of the Rare Earth Orthovanadate The laser-Raman spectra of the tetragonal rare earth orthovanadates of the type LnVO4 (Ln = Pr to Lu) as well as those of ScVO4 and YVO4 has been recorded and interpreted with the aid of both, the site symmetry and the factor group analysis, using also IR data reported previously. The influence of the cations on the internal vibrations of the anion are discussed in detail. 相似文献
29.
Preparation and Properties of Some New Arsenate and Vanadate Halogen Apatites The preparation of new apatite-like compounds of the composition Na2Nd2Pb6(RO4)6X2 (with R = As, V and X = Cl, Br and also R = P and X = Br) is reported. Crystallographic data for these as well as for the already known Na2Nd2Pb6(PO4)6Cl2 are determined from the corresponding X-ray powder diagrams. Also the infrared and Raman spectra were recorded and briefly discussed. 相似文献
30.
Alavi-Harati A Alexopoulos T Arenton M Arisaka K Barbosa RF Barker AR Barrio M Bellantoni L Bellavance A Blucher E Bock GJ Bown C Bright S Cheu E Coleman R Corcoran MD Cox B Erwin AR Escobar CO Ford R Glazov A Golossanov A Gouffon P Graham J Hamm J Hanagaki K Hsiung YB Huang H Jejer V Jensen DA Kessler R Kobrak HG Kotera K LaDue J Lai N Ledovskoy A McBride PL Monnier E Nelson KS Nguyen H Prasad V Qi XR Quinn B Ramberg EJ Ray RE Santos E Senyo K Shanahan P Shields J Slater W Solomey N Swallow EC 《Physical review letters》2003,90(14):141801
The KTeV experiment at Fermilab has isolated a total of 132 events from the rare decay K(L)-->e+ e- mu+ mu-, with an estimated background of 0.8 events. The branching ratio of this mode is determined to be [2.69+/-0.24(stat)+/-0.12(syst)]x10(-9), with a radiative cutoff of M(2)(ee mu mu)/M(2)(K)>0.95. The first measurement using this mode of the parameter alpha from the D'Ambrosio-Isidori-Portolès (DIP) model of the K(L)gamma*gamma* vertex yields a result of -1.59+/-0.37, consistent with values obtained from other decay modes. Because of the limited statistics, no sensitivity is found to the DIP parameter beta. We use this decay mode to set limits on CP and lepton violation. 相似文献