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971.
Emissive europium hydroxide nanorods (ENR) (20 nm x 500 nm) functionalized by a surface coating of chromophore-containing organically modified silicate (ORMOSIL) layer, have been synthesized and characterized by high-resolution transmission electron microscopy (TEM). Low-temperature photophysical characterization of the functionalized nanorods (FENR) demonstrated a strong red 5D0 luminescence both in solid and in suspended solutions. Potentials of this nanorod material for live cell imaging have also been explored. Both the bare and functionalized nanorods are able to enter living human cells with no discernible cytotoxicity. Chromophore-to-Eu3+ energy-transfer in the functionalized nanorods enables staining of the cytoplasm of living human cells. This is confirmed by costaining with fluorescent dextran. The red chromophore-sensitized luminescence from the internalized nanorods in live human lung carcinoma cells (A549) can be observed by confocal microscopy 2 h after loading and reaches maximal emission after 24 h. 相似文献
972.
Wang X Guram A Bunel E Cao GQ Allen JR Faul MM 《The Journal of organic chemistry》2008,73(4):1643-1645
A one-pot procedure for the synthesis of 2-alkyl-2-arylcyanoacetates based on a Pd(OAc)2/DPPF (DPPF = 1,1'-diphenylphosphino ferreocene)-catalyzed enolate arylation followed by in situ alkylation has been developed. This procedure tolerates a diverse range of aryl and heteroaryl bromides, and provides a rapid entry to a variety of 2-alkyl-2-arylcyanoacetates in good to excellent yield. 相似文献
973.
P. Finlay M. Breitenfeldt T. Porobić E. Wursten G. Ban M. Beck C. Couratin X. Fabian X. Fléchard P. Friedag F. Glück A. Herlert A. Knecht V. Y. Kozlov E. Liénard G. Soti M. Tandecki E. Traykov S. Van Gorp Ch. Weinheimer D. Zákoucký N. Severijns 《The European Physical Journal A - Hadrons and Nuclei》2016,52(7):206
974.
Marc Bria Alan Cooper Shanika Gunatilaka Hewage Margaret Nutley 《Tetrahedron letters》2007,48(48):8430-8433
This Letter, describes the complexation of α-, β- and γ-cyclodextrins (1-3) with TTF derivative 4 in water. In particular, we show using 1H, 13C NMR, UV-vis spectroscopy and isothermal titration calorimetry that β-cyclodextrin 2 forms an effective complex with 4. Complex 2·4 can be conveniently disassembled upon the addition of 1-adamantanol. 相似文献
975.
Jex AR Whipp M Campbell BE Cacciò SM Stevens M Hogg G Gasser RB 《Electrophoresis》2007,28(21):3875-3883
In the present study, we used a mutation scanning-targeted sequencing approach to assess variation in part (pgp60) of the 60 kDa glycoprotein (gp60) gene among Cryptosporidium samples from humans in Victoria, Australia. Two nuclear ribosomal loci (the small subunit rRNA gene and the second internal transcribed spacer) were used to identify the samples as Cryptosporidium hominis (n = 74), Cryptosporidium parvum (n = 23) or Cryptosporidium meleagridis (n = 1). In total, nine distinct pgp60 sequences were identified (three C. hominis, five C. parvum and one C. meleagridis). Phylogenetic analyses of the pgp60 sequence data, employing well-defined reference sequences for comparison, allowed the genotypic and subgenotypic classification of samples. The C. hominis samples were classified as Ib A10G2R2, Id A15G1R2, and a new genotype, designated Ib2, was identified subgenotypically as A18G1R4. The C. parvum samples were classified as IIa A18G3R1, IIa A20G3R1, IIa A22G3R1, IIa A23G3R1 and IIc A5G3R2. These findings suggested that the C. hominis metapopulation is largely homogeneous, consisting of a single dominant genotype, Ib A10G2R2, whereas the C. parvum metapopulation is considerably more heterogeneous, with no single dominant genotype. The greater level of genetic heterogeneity found among the C. parvum samples, despite the smaller sample size, may relate to the zoonotic infection pattern of this species, which would be reflective of a greater number of possible infection sources. The present mutation scanning approach, coupled with targeted sequencing of genetically distinct representatives, is a practical, cost-effective tool for large-scale population genetic and epidemiological studies of Cryptosporidium and other eukaryotic organisms. 相似文献
976.
The 1H and 13C NMR data for 3-azabicyclo[3.3.1]nonanes having C-1 methylsuccinimidoanthranilate esters and C-6 methyl ethers were measured and assigned using 1D (DEPT) and 2D (COSY, HSQC, HMBC, NOESY) experiments. Comparison of this with previously published data illustrates the effects of stereochemistry and substitution on the basic heterocyclic framework. 相似文献
977.
978.
Host-defense peptides inhibit bacterial growth but manifest relatively little toxicity toward eukaryotic cells. Many host-defense peptides adopt alpha-helical conformations in which cationic side chains and lipophilic side chains are segregated to distinct regions of the molecular surface ("globally amphiphilic helices"). Several efforts have been made to develop unnatural oligomers that mimic the selective antibacterial activity of host-defense peptides; these efforts have focused on the creation of molecules that are globally amphiphilic in the preferred conformation. One such endeavor, from our laboratories, focused on helix-forming alpha/beta-peptides, i.e., oligomers containing a 1:1 pattern of alpha- and beta-amino acid residues in the backbone [Schmitt, M. A.; Weisblum, B.; Gellman, S. H. J. Am. Chem. Soc. 2004, 126, 6848-6849]. We found, unexpectedly, that the most favorable biological activity profile was displayed by a "scrambled" sequence, which was designed not to be able to form a globally amphiphilic helix. Here we report new data, involving an expanded set of alpha/beta-peptides, from experiments designed to elucidate the origins of this surprising result. In addition, we evaluate the susceptibility of alpha/beta-peptides to proteolytic degradation. Our results support the hypothesis that the ability to adopt a globally amphiphilic helical conformation is not a prerequisite for selective antibacterial activity. This conclusion represents a significant advance in our understanding of the relationship among molecular composition, conformation, and biological activity. Our results should therefore influence the design of other unnatural oligomers intended to function as antibacterial agents. 相似文献
979.
Brian Nunnally SungAe Park Ketaki Patel Mingfang Hong Xinfeng Zhang Shao-Xiong Wang Brenda Rener Angelia Reed-Bogan Oscar Salas-Solano Wendy Lau Michel Girard Heather Carnegie Virginia Garcia-Cañas K. C. Cheng Ming Zeng Margaret Ruesch Ronald Frazier Claudia Jochheim Kshama Natarajan K. Michael Jessop Mansoor Saeed Frank Moffatt Seth Madren Serigne Thiam Kevin Altria 《Chromatographia》2007,66(11-12):955-961
An international project team (including members from US, Canada and UK) was formed from a number of interested biopharmaceutical companies and regulatory authorities to conduct a cross-organisation collaboration exercise. The results of the first comparison with eight different organisations that used instruments of the same equipment model, the same reagents, and the same methodology has been reported previously [1]. This report represents the addition of other instruments using a different run buffer. The relative migration times were different, as expected, prohibiting a direct comparison between companies. The within-organisation variability was low for both relative migration time (<0.34% RSD% for all companies save one) and the peak area (<5% RSD% for all companies save one) when measuring the purity of a representative IgG sample. The apparent molecular weight of bovine serum albumin was measured with good precision (less than 10% RSD% across all companies) to the theoretical value when all data is utilized (67.5 kDa compared to 66.4 kDa). For a representative IgG sample, the three main components, IgG Light Chain, IgG Non-glycosylated Heavy Chain, and IgG Heavy Chain, could not be separated, specifically the IgG Non-glycosylated Heavy Chain and IgG Heavy Chain. When the IgG Non-glycosylated Heavy Chain and IgG Heavy Chain were combined for all organisations, the fractional peak area for the IgG Light Chain and IgG Non-glycosylated Heavy Chain + IgG Heavy Chain peak also showed excellent agreement, with less than 7.5 and 3.5% RSD%, respectively. The value of this exercise is in demonstrating the reliability of CE for the determination of apparent size of biopharmaceutical proteins. This underpins the appropriate use of such CE data in support of regulatory submissions. 相似文献
980.
The addition of small amounts of iodine to thermodynamically instable TeCl2 yields amorphous, glassy tellurium(II) halides TeCl2-xIx (0.1 < x < 0.5), which were prepared by rapid quenching of melts with the respective compositions. At ambient temperature, these glassy solids are sufficiently stable to be handled and investigated by analytical methods. High-energy X-ray diffraction and reverse Monte Carlo simulations of two compositions TeCl2-xIx, x = 0.1 and 0.5, show that these glasses are made up of structural fragments that are present in both tellurium tetrahalides and in low-valent tellurium subhalides. In both glasses, the Te-Te bonding shows narrow coordination distribution with a mean total coordination number for the Te atoms of 4.1 +/- 1.3 and a mean Te-Te coordination number of 0.7 +/- 0.7. Accordingly, the mean Cl-Te coordination number is 1.7 +/- 0.8 and the mean I-Te coordination number is 1.6 +/- 0.7. The medium-range order increases with increasing iodine content. 相似文献