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41.
Gaynor D Starikova ZA Ostrovsky S Haase W Nolan KB 《Chemical communications (Cambridge, England)》2002,(5):506-507
The reaction of 2-(dimethylamino)phenylhydroxamic acid (2-dmAphaH) with NiSO(4).6H2O gives the complex [Ni7(2-dmAphaH-1)2(2-dmApha)8(H2O)2]SO(4).15H2O uniquely exhibiting four distinct hydroxamate binding modes, two of which are novel, and showing both antiferromagnetic and ferromagnetic interactions in contrast to [Cu5(2-dmAphaH-1)4(HSO4)2(MeOH)2].2MeOH, a strongly antiferromagnetic metallacrown formed with CuSO(4).5H2O. 相似文献
42.
Polarization-insensitive nonlinear optical loop mirror demultiplexer with twisted fiber 总被引:2,自引:0,他引:2
Liang Y Lou JW Andersen JK Stocker JC Boyraz O Islam MN Nolan DA 《Optics letters》1999,24(11):726-728
We experimentally demonstrate reduction of the polarization sensitivity of a nonlinear optical loop mirror (NOLM) from 5 to 0.5 dB by use of 550 m of twisted dispersion-shifted fiber with a twist rate of 8 turns/m (24 turns/beat length). The twisting of the fiber induces circular birefringence and equates the parallel-and the orthogonal-polarization nonlinear phase-shift terms. Experimental results show that the polarization sensitivity monotonically decreases from 5 dB for nontwisted fiber to 0.5 dB for fiber that is twisted at a rate of 8 turns/m, and the twist rate should be more than 4 turns/m (>10 turns/beat length) for emulation of circularly polarized fiber. The minimum polarization sensitivity occurs when the control-pulse polarization is aligned with one of the eigenmodes of the twisted fiber. With the fiber twisted at a rate of 8 turns/m in the NOLM, the nonlinear transmission is 23% at a switching energy of 4 pJ/pulse. Simulations confirm the observed behavior and show that the remaining polarization sensitivity results from energy transfer between orthogonal modes of the signal pulse. 相似文献
43.
Summary A convenient synthesis of the ligand ethylenediaminetetraacetamide (L) is described, and a number of metal complexes of the general formula MLCln · xH2O (Mn+=CaII, MnII, FeII, CoII, NII, CuII, ZnII, MgII, BaII, CdII, HgII and LaIII) prepared. The deprotonated Cu(L-H)2 · 2 H2O complex has been characterised and the associated pK values determined. I.r., conductivity, magnetic susceptibility and electronic spectral data are discussed. 相似文献
44.
Fructos MR Belderrain TR Nicasio MC Nolan SP Kaur H Díaz-Requejo MM Pérez PJ 《Journal of the American Chemical Society》2004,126(35):10846-10847
The complex IPrCuCl (1) catalyzes the transfer of the :CHCO2Et group from ethyl diazoacetate (EDA) to unsaturated and saturated substrates (olefins, amine, alcohols) with very high yields. In the absence of substrate, the complex 1 does not react with EDA to give the diazo coupling products (fumarate and maleate), a rare example in the field of metal-catalyzed diazocompounds decomposition. 相似文献
45.
We study the properties of polarization evolution in sinusoidally spun fibers. It is found that, similar to linear birefringent fibers, the evolution of the state of polarization exhibits periodicity, which can be measured by distributed measurement, such as those made with a polarization optical time domain reflectometer. The spatial period is linked with the spin parameters and fiber beat length in a simple equation. In combination with a previous finding, it is shown that the spatial period is uniquely related to spun-fiber polarization mode dispersion. This suggests that distributed fiber polarization mode dispersion can be determined throughthe measurement of the spatial period obtained in a distributed measurement. 相似文献
46.
47.
Nucleobase radicals (e.g., 1) are the major family of reactive intermediates formed when DNA is exposed to gamma-radiolysis. Independent generation of 1 in chemically synthesized oligonucleotides reveals that formation of this nucleobase radical under aerobic conditions results in the formation of tandem lesions approximately 65% of the time. The distribution of lesions formed with the 5'- and 3'-adjacent nucleotides is dependent upon the secondary structure of duplex DNA. Tandem lesions, which are defined as two contiguously, damaged nucleotides in a single DNA strand, are of significant biological interest. The yield of tandem lesions from 1 is much greater than was previously believed. The observations presented could have significant ramifications on how scientists interpret the effects of gamma-radiolysis on DNA. 相似文献
48.
Aradhana Pangasa Aaron R. Jex Matthew J. Nolan Bronwyn E. Campbell Shane R. Haydon Melita A. Stevens Robin B. Gasser 《Electrophoresis》2010,31(10):1637-1647
The high‐resolution analysis of genetic variation has major implications for the identification of parasites and micro‐organisms to species and subspecies as well as for population genetic and epidemiological studies. In this study, we critically assessed the effectiveness of a PCR‐based restriction endonuclease fingerprinting (REF) method for the detection of mutations in the 60 kDa glycoprotein gene (gp60) of Cryptosporidium, a genus of parasitic protists of major human and animal health importance globally. This gene displays substantial intraspecific variability in sequence, particularly in a TCA (perfect and imperfect) microsatellite region, is present as a single copy in the nuclear genome and is used widely as a marker in molecular epidemiological studies of Cryptosporidium hominis and C. parvum, the two predominant species that infect humans. The results of this study demonstrated an exquisite capacity of REF to detect nucleotide variability in the gp60 gene within each of the two species. The differentiation of genotypes/subgenotypes based on REF analysis was supported by targeted sequencing, allowing the detection of levels of variation as low as a single‐nucleotide transversion for amplicons of ∼1 kb in size. The high‐throughput potential and relatively low‐cost of REF make it a particularly useful tool for large‐scale genetic analyses of C. hominis and C. parvum. REF could also be utilized for comparative surveys of genetic variability across large nuclear genomic regions. Such analyses of Cryptosporidium in clinical and environmental samples by REF have important implications for identifying sources of infection, modes of transmission and/or possible infectivity to humans, thus assisting in the surveillance and control of cryptosporidiosis. Given its excellent mutation detection capacity, REF should find broad applicability to various single‐copy genes as well as a wide range of other protozoan and metazoan parasites. (The nucleotide sequences reported in this article are available in the GenBank database under accession numbers GU214343–GU214371). 相似文献
49.
In an attempt to study the scope of a theorem due to Pati, the authors have established that φ(t) logK|t∈B
u
V in (0,π)⟹ΣA
n
(x) is |C, 0,β| forβ>1, at the pointt = x. 相似文献
50.
Marla D. Swain George P. Anderson Dan Zabetakis Rachael D. Bernstein Jinny L. Liu Laura J. Sherwood Andrew Hayhurst Ellen R. Goldman 《Analytical and bioanalytical chemistry》2010,398(1):339-348
Single-domain antibodies (sdAb) specific for botulinum neurotoxin serotype A (BoNT A) were selected from an immune llama phage
display library derived from a llama that was immunized with BoNT A toxoid. The constructed phage library was panned using
two methods: panning on plates coated with BoNT A toxoid (BoNT A Td) and BoNT A complex toxoid (BoNT Ac Td) and panning on
microspheres coupled to BoNT A Td and BoNT A toxin (BoNT A Tx). Both panning methods selected for binders that had identical
sequences, suggesting that panning on toxoided material may be as effective as panning on bead-immobilized toxin for isolating
specific binders. All of the isolated binders tested were observed to recognize bead-immobilized BoNT A Tx in direct binding
assays, and showed very little cross-reactivity towards other BoNT serotypes and unrelated protein. Sandwich assays that incorporated
selected sdAb as capture and tracer elements demonstrated that all of the sdAb were able to recognize soluble (“live”) BoNT
A Tx and BoNT Ac Tx with virtually no cross-reactivity with other BoNT serotypes. The isolated sdAb did not exhibit the high
degree of thermal stability often associated with these reagents; after the first heating cycle most of the binding activity
was lost, but the portion of the protein that did refold and recover antigen-binding activity showed only minimal loss on
subsequent heating and cooling cycles. The binding kinetics of selected binders, assessed by both an equilibrium fluid array
assay as well as surface plasmon resonance (SPR) using toxoided material, gave dissociation constants (K
D ) in the range 2.2 × 10−11 to 1.6 × 10−10 M. These high-affinity binders may prove beneficial to the development of recombinant reagents for the rapid detection of
BoNT A, particularly in field screening and monitoring applications. 相似文献