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71.
Tim Redmond Charles Ryavec J. Edmonds A. Mandel L. Lovász 《Mathematical Intelligencer》1980,2(2):106-107
72.
73.
(±)-iso-Amarine is a potent organocatalyst at 1 mol % loading for both the bromoacetoxylation of alkenes with added acetic acid and bromolactonisation of unsaturated carboxylic acids with stoichiometric NBS as the electrophilic bromine source. A simple bromoamidine with an N-Br bond has been characterised crystallographically for the first time. Asymmetric induction in the bromination reactions with enantiopure amidines was zero. 相似文献
74.
Photophysical Properties of Tin Ethyl Etiopurpurin I (SnET2) and Tin Octaethylbenzochlorin (SnOEBC) in Solution and Bound to Albumin 总被引:2,自引:0,他引:2
Brian W. Pogue Robert W. Redmond Niraj Trivedi Tayyaba Hasan 《Photochemistry and photobiology》1998,68(6):809-815
Abstract— The photophysical characteristics of two second-generation PDT photosensitizers, tin ethyl etiopurpurin I (SnET2 ) and tin octaethylbenzochlorin (SnOEBC), have been measured in homogeneous solution and when bound to bovine serum albumin (BSA). The ground state and triplet state absorption spectra have been characterized, as have triplet lifetimes and quantum yields for intersys-tem crossing, singlet oxygen formation and photobleaching. In total, these parameters provide a complete set of data that can be used to quantitatively compare the photosensitizing efficiencies of these molecules. The photo-bleaching quantum yield of SnET2 is increased dramatically when it is bound to BSA, thus limiting the production of singlet oxygen at incident fluences above 1 J/cm2 . In contrast, the quantum yield of photobleaching of SnOEBC is at least an order of magnitude lower than that of SnET2 under these conditions and does not significantly limit the photosensitization process for typical in vivo or in vitro fluences. This difference is expected to play a significant role in determining the relative photosensitizing ability of these compounds in vivo. 相似文献
75.
Batrice M. Aveline Tayyaba Hasan Robert W. Redmond 《Journal of photochemistry and photobiology. B, Biology》1995,30(2-3):161-169
Absorption, fluorescence and laser flash photolysis spectroscopies were used to investigate the effects of self-aggregation, binding to human serum albumin and incorporation in cancer cells on the photophysics of benzoporphyrin derivative monoacid ring A (BPDMA). Aggregation of BPDMA has been studied in mixtures of methanol and phosphate-buffered saline (PBS). The extent of aggregation was dependent on dye concentration and solvent composition, becoming particularly marked in mixtures containing less than 30% methanol. A dimerization constant Kd or 9 × 106 M−1 was determined by fluorescence experiments for BPDMA in pure PBS. In addition to spectral modifications, aggregation induces a lowering of the fluorescence and intersystem crossing quantum yields. Human serum albumin binds BPDMA with an association constant Kb of 5.2 × 105 M−1 in PBS. When bound to HSA, BPDMA displays photophysical properties very similar to the monomer in organic solvents. The molar ratio [HSA]/[BPDMA] corresponding to complete binding of the dye was determined to be approximately 10. Efficient generation of the triplet state of BPDMA was also observed from aqueous cellular suspensions containing incorporated photosensitizer. 相似文献
76.
Lüdemann HC Redmond RW Hillenkamp F 《Rapid communications in mass spectrometry : RCM》2002,16(13):1287-1294
Laser-induced fluorescence spectroscopy was carried out on microcrystalline samples of three typical matrices under conditions of matrix-assisted laser desorption/ionization (MALDI). The emitted fluorescence intensity was determined as a function of incident laser fluence and a sublinear increase of the fluorescence intensity with laser fluence was found. A very good fit was obtained when the experimental fluorescence vs. fluence data were compared with a numerical model assuming that under typical MALDI fluence conditions a large fraction of molecules in the excited singlet state undergoes singlet-singlet annihilation. Throughout the fluence range relevant for MALDI, however, the experimental data could not be fit well to a model assuming resonant two-photon absorption as the process depopulating the singlet state. In a separate set of experiments, the singlet lifetimes of several typical crystalline MALDI matrices were determined and found to be considerably shorter than previously reported. While both singlet-singlet annihilation and resonant two-photon absorption have been discussed in the literature as candidates for pathways to primary matrix ion generation in MALDI, the data presented here suggest that singlet-singlet annihilation is the dominant mechanism for depopulating the singlet state in a matrix crystal excited at typical MALDI fluences. 相似文献
77.
Charles R. Clark Allan G. Blackman Akbar Mobinikhaledi Wayne A. Redmond Rex T. Weavers 《Angewandte Chemie (International ed. in English)》1998,37(8):1133-1135
In a one-pot synthesis at room temperature the N-methylpyridazinium ion ( 1 ) dimerizes stereospecifically and with 100 % conversion in a series of OH−-catalyzed processes to give a new tetraazafluorene ( 2 ). Four of the individual steps can be identified directly and monitored by 1H NMR spectroscopy. 相似文献
78.
BeatrizG. delaTorre JuanCarlos Morales Anna Avi Daniela Iacopino Andrea Ongaro Donald Fitzmaurice Deirdre Murphy Hugh Doyle Gareth Redmond Ramon Eritja 《Helvetica chimica acta》2002,85(9):2594-2607
Oligodeoxynucleotide conjugates 1 – 15 carrying anchoring groups such as amino, thiol, pyrrole, and carboxy groups were prepared. A post‐synthetic modification protocol was developed. In this method 2′‐deoxy‐O4‐(p‐nitrophenyl)uridine‐3‐phosphoramidite was prepared and incorporated in oligonucleotides. After assembly, the modified nucleoside was made to react with different amines carrying the anchoring groups. At the same time, protecting groups were removed to yield the desired oligonucleotide conjugates. In a second approach, amino, thiol, and carboxylic groups were introduced into the 3′‐end of the oligonucleotides by preparing solid supports loaded with the appropriate amino acids. Oligonucleotide gold conjugates were prepared and their binding properties were examined. 相似文献
79.
80.
UHPLC‐MS/MS quantification of buprenorphine,norbuprenorphine, methadone,and glucuronide conjugates in umbilical cord plasma 下载免费PDF全文
Amy Redmond Kyle Jennifer Carmical Darshan Shah Jason Pryor Stacy Brown 《Biomedical chromatography : BMC》2015,29(10):1567-1574
Opioid use during pregnancy can result in the newborn being physically dependent on the substance, thus experiencing drug withdrawal, termed neonatal abstinence syndrome (NAS). Buprenorphine and methadone are two drugs used to treat opioid withdrawal and are approved for use in pregnancy. Quantification of these compounds in umbilical cord plasma would help assess in utero exposure of neonates in cases of buprenorphine or methadone use during pregnancy. An LC‐MS/MS method using solid‐phase extraction sample preparation was developed and validated for the simultaneous quantification of methadone, buprenorphine, norbuprenorphine, and glucuronide metabolites in umbilical cord plasma. The average accuracy (percentage error) and precision (relative standard deviation) were <15% for each validated concentration. Our data establishes a 2 week maximum freezer storage window in order to achieve the most accurate cord plasma concentrations of these analytes. Additionally, we found that the umbilical cord tissue analysis was less sensitive compared with analysis with umbilical cord blood plasma, indicating that this may be a more appropriate matrix for determination of buprenorphine and metabolite concentrations. This method was successfully applied to the analysis of cord blood from women with known buprenorphine or methadone use during pregnancy. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献