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41.
Tvaskis V Christy ME Arrington J Asaturyan R Baker OK Blok HP Bosted P Boswell M Bruell A Cochran A Cole L Crowder J Dunne J Ent R Fenker HC Filippone BW Garrow K Gasparian A Gomez J Jackson HE Keppel CE Kinney E Lapikás L Liang Y Lorenzon W Lung A Mack DJ Martin JW McIlhany K Meekins D Milner RG Mitchell JH Mkrtchyan H Moreland B Nazaryan V Niculescu I Opper A Piercey RB Potterveld DH Rose B Sato Y Seo W Smith G Spurlock K van der Steenhoven G Stepanyan S Tadevosian V Uzzle A Vulcan WF Wood SA 《Physical review letters》2007,98(14):142301
We report on a study of the longitudinal to transverse cross section ratio, R=sigmaL/sigmaT, at low values of x and Q2, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06相似文献
42.
Juan M. Muñoz-Ocaña Ainouna Bouziane Farzeen Sakina Richard T. Baker Ana B. Hungría Jose J. Calvino Antonio M. Rodríguez-Chía Miguel López-Haro 《Particle & Particle Systems Characterization》2020,37(6):2000070
A novel procedure to optimize the 3D morphological characterization of nanomaterials by means of high angle annular dark field scanning-transmission electron tomography is reported and is successfully applied to the analysis of a metal- and halogen-free ordered mesoporous carbon material. The new method is based on a selection of the two parameters (μ and β) which are key in the reconstruction of tomographic series by means of total variation minimization (TVM). The parameter-selected TVM reconstructions obtained using this approach clearly reveal the porous structure of the carbon-based material as consisting of a network of parallel, straight channels of ≈6 nm diameter ordered in a honeycomb-type arrangement. Such an unusual structure cannot be retrieved from a TVM 3D reconstruction using default reconstruction values. Moreover, segmentation and further quantification of the optimized 3D tomographic reconstruction provide values for different textural parameters, such as pore size distribution and specific pore volume that match very closely with those determined by macroscopic physisorption techniques. The approach developed can be extended to other reconstruction models in which the final result is influenced by parameter choice. 相似文献
43.
Philip A. Baker Andrew F. Coffey Roger Epton Tony Johnson Edward J. Mole 《Macromolecular Symposia》1988,19(1):79-91
2, 4-Dinitrophenyl-L-phenylalanine has been coupled to L-, D-, and DL-amino acid phenyl esters pendant upon a polymer matrix. The esters had been prepared by di-isopropylcarbodiimide-mediated condensation, catalyzed by 4-dimethylaminopyridine. Reverse phase high pressure liquid chromatography (HPLC), using elution solvents consisting of 10 vol.-% trifluoroacetic acid in water/acetonitrile mixtures, has been used to investigate the 2,4-dinitrophenyl L-L and L-D dipeptide mixtures obtained on hydrazinolysis of each of the dipeptide-matrix assemblies. ‘Hydrazinolysis-HPLC’ has been used also to determine intermediate peptide homogeneity in ultra-high load solid (gel) phase synthesis with Boc amino acids. Cross-linked poly(N-[2-(4-hydroxyphenyl)ethyl]acrylamide) and two derived polymers incorporating spacer groups have been used as supports. The spacer groups made possible peptide C-terminal attachment by either HF-labile benzyl ester or HF-labile cyclohexyl ester bonds, while still incorporating the phenolic ester linkage susceptible to rapid hydrazinolytic scission. 相似文献
44.
Alyssa B. Sanders Jacob T. Zangaro Nakoa K. Webber Ryan P. Calhoun Elizabeth A. Richards Samuel L. Ricci Hannah M. Work Daniel D. Yang Kaitlyn R. Casey Joseph C. Iovine Gabriela Baker Taylor V. Douglas Sierra B. Dutko Thomas J. Fasano Sarah A. Lofland Ashley A. Rajan Mihaela A. Vasile Benjamin R. Carone Nathaniel V. Nucci 《Molecules (Basel, Switzerland)》2022,27(5)
Despite considerable advances in recent years, challenges in delivery and storage of biological drugs persist and may delay or prohibit their clinical application. Though nanoparticle-based approaches for small molecule drug encapsulation are mature, encapsulation of proteins remains problematic due to destabilization of the protein. Reverse micelles composed of decylmonoacyl glycerol (10MAG) and lauryldimethylamino-N-oxide (LDAO) in low-viscosity alkanes have been shown to preserve the structure and stability of a wide range of biological macromolecules. Here, we present a first step on developing this system as a future platform for storage and delivery of biological drugs by replacing the non-biocompatible alkane solvent with solvents currently used in small molecule delivery systems. Using a novel screening approach, we performed a comprehensive evaluation of the 10MAG/LDAO system using two preparation methods across seven biocompatible solvents with analysis of toxicity and encapsulation efficiency for each solvent. By using an inexpensive hydrophilic small molecule to test a wide range of conditions, we identify optimal solvent properties for further development. We validate the predictions from this screen with preliminary protein encapsulation tests. The insight provided lays the foundation for further development of this system toward long-term room-temperature storage of biologics or toward water-in-oil-in-water biologic delivery systems. 相似文献
45.
Peter Sörös Jonathan Marmurek Fred Tam Nicole Baker W Richard Staines Simon J Graham 《BMC neuroscience》2007,8(1):48
Background
Focal lesions of the frontal, parietal and temporal lobe may interfere with tactile working memory and attention. To characterise the neural correlates of intact vibrotactile working memory and attention, functional MRI was conducted in 12 healthy young adults. Participants performed a forced-choice vibrotactile frequency discrimination task, comparing a cue stimulus of fixed frequency to their right thumb with a probe stimulus of identical or higher frequency. To investigate working memory, the time interval between the 2 stimuli was pseudo-randomized (either 2 or 8 s). To investigate selective attention, a distractor stimulus was occasionally presented contralaterally, simultaneous to the probe. 相似文献46.
RD Harris WS Baker Van Stipdonk MJ RM Crooks EA Schweikert 《Rapid communications in mass spectrometry : RCM》1999,13(14):1374-1380
A suite of keV polyatomic or 'cluster' projectiles was used to bombard unoxidized and oxidized self-assembled monolayer surfaces. Negative secondary ion yields, collected at the limit of single ion impacts, were measured and compared for both molecular and fragment ions. In contrast to targets that are orders of magnitude thicker than the penetration range of the primary ions, secondary ion yields from polyatomic projectile impacts on self-assembled monolayers show little to no enhancement when compared with monatomic projectiles at the same velocity. This unusual trend is most likely due to the structural arrangement and bonding characteristics of the monolayer molecules with the Au(111). Copyright 1999 John Wiley & Sons, Ltd. 相似文献
47.
Baker KL Stappaerts EA Gavel D Wilks SC Tucker J Silva DA Olsen J Olivier SS Young PE Kartz MW Flath LM Kruelevitch P Crawford J Azucena O 《Optics letters》2004,29(15):1781-1783
Results of atmospheric propagation for a high-speed, large-actuator-number adaptive optics system are presented. The system uses a microelectromechanical system- (MEMS-) based spatial light modulator correction device with 1024 actuators. Tests over a 1.35-km path achieved correction speeds in excess of 800 Hz and Strehl ratios close to 0.5. The wave-front sensor was based on a quadrature interferometer that directly measures phase. This technique does not require global wave-front reconstruction, making it relatively insensitive to scintillation and phase residues. The results demonstrate the potential of large-actuator-number MEMS-based spatial light modulators to replace conventional deformable mirrors. 相似文献
48.
We refine our earlier work on the existence and uniqueness of structures on -theoretic spectra to show that the connective versions of real and complex -theory as well as the connective Adams summand at each prime have unique structures as commutative -algebras. For the -completion we show that the McClure-Staffeldt model for is equivalent as an ring spectrum to the connective cover of the periodic Adams summand . We establish a Bousfield equivalence between the connective cover of the Lubin-Tate spectrum and .
49.
50.
The classification of perfectBaer subplane partitions of PG(2, q2) is equivalentto the classification of 3-dimensional flag-transitive planeswhose translation complements contain a linear cyclic group actingregularly on the line at infinity. Since all known flag-transitiveplanes admit a translation complement containing a linear cyclicsubgroup which either acts regularly on the points of the lineat infinity or has two orbits of equal size on these points,such a classification would be a significant step towards theclassification of all 3-dimensional flag-transitive planes. Usinglinearized polynomials, a parametric enumeration of all perfectBaer subplane partitions for odd q is described.Moreover, a cyclotomic conjecture is given, verified by computerfor odd prime powers q < 200, whose truth would implythat all perfect Baer subplane partitions arise from a constructionof Kantor and hence the corresponding flag-transitive planesare all known. 相似文献