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11.
A. S. Hegazi Hani Abdelwahab A. J. Calderon Martin 《Algebras and Representation Theory》2018,21(1):19-45
The paper is devoted to classify all of the nilpotent Malcev algebras of dimension ≤ 6 over an arbitrary base field ?? of characteristic not 2. We also classify all 7-dimensional non-Lie nilpotent Malcev algebras which are not metabelian over any field of characteristic not 2. 相似文献
12.
Rubén A. Toscano Rachel Mata José Calderon Rosabel Segura 《Journal of chemical crystallography》1996,26(10):707-711
Chloroform/Methanol extraction of the bark ofCedrela salvadorensis (Meliaceae), followed by chromatography afforded the crystalline C28H34O7 terpene. The structure first proposed by spectroscopy is confirmed by this X-ray analysis as 7-acetyloxy-14,15:21,23-diepoxy-4,4,8-trimethyl-d-homo-24-nor-17-oxachola-1,20,22-triene-3,16,-dione. The title compound crystallized in the orthorhombic space groupP212121 with unit cell parametersa=10.243(2),b=13.356(3) andc=18.058(4) Å. The molecule is comprised of a six-membered tetracyclic skeleton, with a circular arc overall conformation. No intermolecular hydrogen bonding is indicated. 相似文献
13.
A Bioorthogonal Small‐Molecule‐Switch System for Controlling Protein Function in Live Cells
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Dr. Peng Liu Abram Calderon Dr. Georgios Konstantinidis Dr. Jian Hou Dipl. Stephanie Voss Dr. Xi Chen Fu Li Soumya Banerjee Dr. Jan‐Erik Hoffmann Christiane Theiss Dr. Leif Dehmelt Dr. Yao‐Wen Wu 《Angewandte Chemie (International ed. in English)》2014,53(38):10049-10055
Chemically induced dimerization (CID) has proven to be a powerful tool for modulating protein interactions. However, the traditional dimerizer rapamycin has limitations in certain in vivo applications because of its slow reversibility and its affinity for endogenous proteins. Described herein is a bioorthogonal system for rapidly reversible CID. A novel dimerizer with synthetic ligand of FKBP′ (SLF′) linked to trimethoprim (TMP). The SLF′ moiety binds to the F36V mutant of FK506‐binding protein (FKBP) and the TMP moiety binds to E. coli dihydrofolate reductase (eDHFR). SLF′‐TMP‐induced heterodimerization of FKBP(F36V) and eDHFR with a dissociation constant of 0.12 μM . Addition of TMP alone was sufficient to rapidly disrupt this heterodimerization. Two examples are presented to demonstrate that this system is an invaluable tool, which can be widely used to rapidly and reversibly control protein function in vivo. 相似文献
14.
The static dielectric constants, ε(s), of ice-Ih and liquid water were calculated using density functional theory with the Perdew-Burke-Ernzerhof (PBE) exchange-correlation functional and the projector-augmented-wave (PAW) approach. Proton disordered ice configurations and uncorrelated liquid configurations were sampled with the electrostatic switching method using force fields specially designed to facilitate the ab initio free energy perturbation calculations. Our results indicate that PAW-PBE underestimates the ε(s) of both ice-Ih and liquid water but predicts the ratio of ice and water ε(s) in good agreement with experimental measurements. PAW-PBE gives average water dipole moments of 2.50 D in ice-Ih and 2.48 D in the liquid. Our results show that the fixed-charge water models developed by adaptive force matching can reproduce the PAW-PBE dipole moments with an error of approximately 5%. The ice and liquid models created in this work have polarizabilities of 1.32 ?(3) and 1.30 ?(3), respectively, along the HOH bisector direction. 相似文献
15.
Elyssia S. Gallagher Seid M. Adem Leonard K. Bright Isen A. C. Calderon Elisabeth Mansfield Craig A. Aspinwall 《Electrophoresis》2014,35(8):1099-1105
Protein separations in CZE suffer from nonspecific adsorption of analytes to the capillary surface. Semipermanent phospholipid bilayers have been used to minimize adsorption, but must be regenerated regularly to ensure reproducibility. We investigated the formation, characterization, and use of hybrid phospholipid bilayers (HPBs) as more stable biosurfactant capillary coatings for CZE protein separations. HPBs are formed by covalently modifying a support with a hydrophobic monolayer onto which a self‐assembled lipid monolayer is deposited. Monolayers prepared in capillaries using 3‐cyanopropyldimethylchlorosilane (CPDCS) or n‐octyldimethylchlorosilane (ODCS) yielded hydrophobic surfaces with lowered surface free energies of 6.0 ± 0.3 or 0.2 ± 0.1 mJ m?2, respectively, compared to 17 ± 1 mJ m?2 for bare silica capillaries. HPBs were formed by subsequently fusing vesicles comprised of 1,2‐dilauroyl‐sn‐glycero‐3‐phosphocholine or 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine to CPDCS‐ or ODCS‐modified capillaries. The resultant HPB coatings shielded the capillary surface and yielded reduced electroosmotic mobility (1.3–1.9 × 10?4 cm2 V?1s?1) compared to CPDCS‐ and ODCS‐modified or bare capillaries (3.6 ± 0.2 × 10?4 cm2 V?1s?1, 4.8 ± 0.4 × 10?4 cm2 V?1s?1, and 6.0 ± 0.2 × 10?4 cm2 V?1s?1, respectively), with increased stability compared to phospholipid bilayer coatings. HPB‐coated capillaries yielded reproducible protein migration times (RSD ≤ 3.6%, n ≥ 6) with separation efficiencies as high as 200 000 plates/m. 相似文献
16.
This Article reveals a rare synthesis of pure Pr(2)O(2)CO(3) (POC) nanopowder by thermolysis (700 °C) of a single chemical precursor in an autogenic reaction. The autogenic thermolysis of praseodymium acetate is a solvent-free, efficient, and straightforward approach yielding luminescent POC nanoparticles. The as-prepared POC nanopowder converted to PrO(1.833) (PO) powder via combustion. Methodical morphological, structural, and compositional characterizations of POC and PO powders are carried out, supported by mechanistic elucidation and the photoluminescent properties. 相似文献
17.
Mahrour A. Lacroix M. Nketsa-Tabiri J. Calderon N. Calderon R. Gagnon M. 《Radiation Physics and Chemistry》1998,52(1-6):77-80
This study was undertaken to determine if a combined treatment (marinating in natural plant extracts or vacuum) with irradiation could have a synergistic effect, in order to prevent the lipid oxidation resulting in the development of undesirable flavours. The fresh chicken legs were irradiated at 0,3 and 5 kGy. The fatty acids composition of lipids was identified using gas liquid chromatography. The effect of irradiation treatment combined with a pre-treatment on the fatty acids composition was followed. The day after irradiation, ten panallists were asked to evaluate, using the instruction scaling, the overall appearance, the odor, the flavor and the overall acceptability of the samples. The major fatty acids identified in lipids were oleic acid, palmitic acid, palmitoleic acid and stearic acid. Pre-treatments have a significant effect on linoleic acid (C18:2) and higher fatty acids. The unsaturated fatty acids derived from phospholipids appeared to be more affected by the irradiation dose: however, marinating have better protection on C18:2 derived from phospholipids. The results of sensory evaluation have shown a significant better odor and flavor for the irradiated chicken at 5 kGy than the control. No significant difference have been found between the marinated chicken, the chicken irradiated under vacuum and the control. 相似文献
18.
María Gallego Joaquín Calbo Dr. Juan Aragó Rafael M. Krick Calderon Fernando H. Liquido Takahiro Iwamoto Allison K. Greene Edward A. Jackson Dr. Emilio M. Pérez Prof. Dr. Enrique Ortí Prof. Dr. Dirk M. Guldi Prof. Dr. Lawrence T. Scott Prof. Dr. Nazario Martín 《Angewandte Chemie (International ed. in English)》2014,53(8):2170-2175
Herein, we investigate the association of a fullerene fragment, hemifullerene C30H12, with an electron‐donating bowl‐shaped tetrathiafulvalene derivative (truxTTF). UV/Vis titrations and DFT calculations support formation of the supramolecular complex, for which an association constant of log Ka=3.6±0.3 in CHCl3 at room temperature is calculated. Remarkably, electron transfer from truxTTF to C30H12 to form the fully charge‐separated species takes place upon irradiation of the associate with light, constituting the first example in which a fullerene fragment mimics the electron‐accepting behavior of fullerenes within a supramolecular complex. 相似文献
19.
M. A. Pedrosa C. Hidalgo E. Calderon A. Alonso R. O. Orozco J. L. De Pablos TJ-II team P. Balan 《Czechoslovak Journal of Physics》2005,55(12):1579-1587
The influence of plasma density and edge gradients in the development of perpendicular sheared flow has been investigated
in the plasma edge region of the TJ-II stellarator. It has been experimentally observed that the generation of spontaneous
perpendicular sheared flow (i.e. the naturally occurring shear layer) requires a minimum plasma density or gradient. It has
been found that there is a coupling between the onset of sheared flow development and an increase in the level of plasma edge
turbulence; once sheared flow is fully developed the level of fluctuations and turbulent transport slightly decreases whereas
edge gradients and plasma density increase. The resulting shearing rate is close to the one required to trigger a transition
to improved confinement regimes with reduction of edge turbulence, showing that spontaneous sheared flows and fluctuations
keep themselves near marginal stability.
Presented at the Workshop “Electric Fields, Structures and Relaxation in Edge Plasmas”, Tarragona, Spain, July 3–4, 2005. 相似文献
20.
Concepción A. Monje Antonio J. Calderon Blas M. Vinagre Yangquan Chen Vicente Feliu 《Nonlinear dynamics》2004,38(1-2):369-381
The objective of this work is to find out optimum settings for a fractional PI controller in order to fulfill three different robustness specifications of design for the compensated system, taking advantage of the fractional order, . Since this fractional controller has one parameter more than the conventional PI controller, one more specification can be fulfilled, improving the performance of the system and making it more robust to plant uncertainties, such as gain and time constant changes. For the tuning of the controller an iterative optimization method has been used, based on a nonlinear function minimization. Two real examples of application are presented and simulation results are shown to illustrate the effectiveness of this kind of unconventional controllers. 相似文献