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Results 351 - 400 of 1601
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Zhang Huiting - - 2007
Molecular imprinted polymers (MIPs) binding with phenoxyacetic acid (PA) as a dummy template molecule were synthesized via thermal initiation in aqueous medium. The retention behaviors of benzoic acid (BA), PA, 2-methyl-4-chlorophenoxyacetic acid (MCPA), 4-chlorophenoxyacetic acid (4-CPA), and 2,4-dichlorophenoxyacetic acid (2,4-D) on this MIP column indicate that this material can selectively ...
Moore David J - - 2007
Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC) studies are reported for combinations of cis-6-octadecenoic acid (also termed petroselinic acid, PSA) and octadecanoic acid (also termed stearic acid, SA) across a wide range of binary mole ratio combinations. The data are then used to plot the phase diagram ...
Próchniak G - - 2007
The crystal structure of the title compound, C(12)H(12)O(6)P(2), displays two different regions alternating along the a axis: a hydrogen-bonded region encompassing the end-positioned phosphonic acid groups and a hydrophobic region formed by the aromatic spacers. The asymmetric unit contains only half of the biphenyl-4,4'-diphosphonic acid (4,4'-bpdp) molecule, which is symmetric ...
Mairal Teresa - - 2008
Aptamers are artificial nucleic acid ligands, specifically generated against certain targets, such as amino acids, drugs, proteins or other molecules. In nature they exist as a nucleic acid based genetic regulatory element called a riboswitch. For generation of artificial ligands, they are isolated from combinatorial libraries of synthetic nucleic acid ...
Zheng Jinhua - - 2008
A novel method is proposed in this paper, that is the silver nanoparticle (nanoAg)-cetyltrimethylammonium bromide (CTMAB) is used as the probe of resonance light scattering (RLS) for the determination of nucleic acids. Under optimum conditions, there are linear relationships between the quenching extent of RLS and the concentration of nucleic ...
Fischer Nicholas O - - 2007
Nucleic acid (aptasensors) have found steadily increased utility and application over the past decade. In particular, aptamers have been touted as a valuable complement to and, in some cases, replacement for antibodies owing to their structural and functional robustness as well as their ease in generation and synthesis. They are ...
Marsh Derek - - 2007
Three derivatives of the hydrophobic, channel-forming peptaibiotic alamethicin (F50/5) have been synthesized, the original Aib residue at position 1, 8, or 16 being replaced with the spin-labeled amino acid TOAC (=2,2,6,6-tetramethylpiperidin-1-oxyl-4-amino-4-carboxylic acid). Electron-paramagnetic-resonance (EPR) spectroscopy was used to characterize the rotational diffusion of these compounds in five isotropic solvents of ...
Jacobsen Mikkel F - - 2007
The development of more selective chemotherapeutic agents for benign treatments of malicious diseases is highly desirable. In recent years model systems for the release of small molecule drugs from nucleic acid conjugates by templated chemical or photochemical reactions have been designed. Common for these systems is that the stoichiometric or ...
Auffinger Pascal - - 2007
Nucleic acids are polyanionic molecules that were historically considered to be solely surrounded by a shell of water molecules and a neutralizing cloud of monovalent and divalent cations. In this respect, recent experimental and theoretical reports demonstrate that water molecules within complex nucleic acid structures can display very long residency ...
Sanders Niek N - - 2007
Ocular gene therapy may offer new hope for severe eye diseases. Many of these ocular diseases are due to a gene defect in the retina, a multi-layered sensory tissue that lines the back of the eye. However, it is well known that the blood-retina barrier and sclera prevent hydrophilic and ...
Cai Changqun - - 2008
The interaction of Acid chrome blue K (ACBK) with nucleic acids in weak basic medium was studied in the presence of cetyltrimethylammonium bromide (CTMAB) based on the measurements of resonance light scattering (RLS), UV-vis, NMR spectra, etc. In hexamethylene tetramine (HMTA) buffer (pH 7.45), ACBK and nucleic acids react with ...
Lindegaard Dorthe - - 2008
Detection of nucleic acid hybridization via fluorescence resonance energy transfer (FRET) using pyren-1-ylmethyl and perylen-3-ylmethyl N2'-functionalized 2'-amino-LNA nucleosides incorporated into oligonucleotides exhibited a clear distance dependence of the FRET efficiency, ranging from below 10% when the fluorophores were approximately 40A apart to approximately 90% when the fluorophores were in close ...
Phe M-H - - 2007
Several studies have shown that the staining by fluorochromes (DAPI, SYBR Green II, and TOTO-1) of bacteria is altered by chlorination. To evaluate the effect of chlorine (bleach solution) on propidium iodide (PI) staining, we studied Escherichia coli in suspension and biomolecules in solution (DNA, RNA, BSA, palmitic acid, and ...
Grégoire Gilles - - 2007
In recent experiments, the excited-state lifetimes of protonated aromatic amino acids (TrpH+ and TyrH+) have been recorded by means of pump-probe photodissociation technique. The lifetime of TyrH+ is much longer than that of TrpH+, which has been initially rationalized on the basis of a simple phenomenological model. Besides, specific photofragments ...
Remaut K - - 2007
The use of non-viral gene carriers to deliver small nucleic acids like antisense oligonucleotides (ODNs) and small interfering RNA (siRNA) remains an attractive but challenging goal in antisense therapy. Indeed, different barriers need to be overcome in the delivery process before a therapeutic effect can be obtained. One promising technique ...
Fernando Chrisantha - - 2007
The origin of nucleic acid template replication is a major unsolved problem in science. A novel stochastic model of nucleic acid chemistry was developed to allow rapid prototyping of chemical experiments designed to discover sufficient conditions for template replication. Experiments using the model brought to attention a robust property of ...
Yessine Marie-Andrée - - 2007
The efficiency of nucleic acid-based drugs is usually hampered by the fact that, following their uptake by the cell, these drugs end up in acidic organelles (i.e., endosomes/lysosomes) from which they barely escape. This work relates to the preparation and characterization of polyion complex micelles (PICM) formed by the self-assembly ...
Anastasi Carole - - 2007
Spectacular advances in structural and molecular biology have added support to the 'RNA world' hypothesis, and provide a mandate for chemistry to explain how RNA might have been generated prebiotically on the early earth. Difficulties in achieving a prebiotically plausible synthesis of RNA, however, have led many to ponder the ...
Zhou Ding - - 2007
Aminopropyl nucleic acids (APNAs) are constitutionally simple nucleic acid alternatives with one stereogenic center per nucleotide, and with the potential to hybridize with RNA and to exert catalytic functions. We have developed a protecting group strategy to synthesize APNAs, although in a not very efficient way. Isolation and purification of ...
Schiffelers Raymond M - - 2007
At present, there are no intravenously administered nucleic acid-based therapeutics that have been approved for human use. This reflects the difficulties in applying nucleic acid-based drugs: they are nuclease sensitive and have difficulties in reaching their site of action. Important challenges for intravenously administered nucleic acid formulations are the requirements ...
Tam-Chang Suk-Wah - - 2007
In this article, we present the design principles and application of a motif composed of a stem-loop probe (SP) hybridized to a fluorescently labeled universal reporter (UR) for sensing unlabeled nucleic acids. At room temperature, SP-UR is in the hairpin-closed form in which the fluorophore of UR is in proximity ...
Li Weijun - - 2007
Lipid-based colloidal particles have been extensively studied as systemic gene delivery carriers. The topic that we would like to emphasize is the formulation/assembly of lipid-based nanoparticles (NP) with diameter under 100 nm for delivering nucleic acid in vivo. NP are different from cationic lipid-nucleic acid complexes (lipoplexes) and are vesicles ...
Shchepinov Mikhail S - - 2007
A method is proposed that has the potential to lessen detrimental damages caused by reactive oxygen species (ROS) to proteins, nucleic acids, lipids, and other components in living cells. Typically, ROS oxidize substrates by a mechanism involving hydrogen abstraction in a rate-limiting step. The sites within these (bio)molecules susceptible to ...
Richmond-Aylor Amy - - 2007
Conventional development of latent fingerprints is compromised when the prints are decomposed by extreme temperatures, such as those encountered when a weapon cartridge is fired, an improvised explosive device is detonated, and/or in arson cases. Understanding how these extreme temperatures alter the chemical and physical properties of latent fingerprint residue ...
Bartlett Derek W DW Chemical Engineering, California Institute of Technology, Pasadena, California 91125, - - 2007
Nucleic acid-based therapeutics have the potential to provide potent and highly specific treatments for a variety of human ailments. However, systemic delivery continues to be a significant hurdle to success. Multifunctional nanoparticles are being investigated as systemic, nonviral delivery systems, and here, we describe the physicochemical and biological characterization of ...
Hunter Ken C - - 2007
The present study uses density functional theory to carefully consider the effects of the environment on the enhancement in (natural and damaged) DNA nucleobase acidities because of multiple hydrogen-bonding interactions. Although interactions with one small molecule can increase the acidity of the nucleobases by up to 60 kJ mol-1 in ...
Yan Hongbin - - 2007
Nucleic acids bearing glycans of various structures have been under vigorous investigation in the past decade. The carbohydrate moieties of such complexes can serve as recognition sites for carbohydrate-binding proteins-lectins-and initiate receptor-mediated endocytosis. Therefore, carbohydrates can enhance cell targeting and internalization of nucleic acids that are associated with them and ...
Hashidoko Yasuyuki - - 2007
Throughout Central and South Kalimantan, Indonesia, strongly acidic soil (pH 2.1-3.7) is widely distributed, and the local acidic soil-tolerant plants, including local rice varieties, often possess sphingomonads in their rhizosphere and rhizoplane. To investigate the behavior of sphingomonads inhabiting the rhizosphere of such acid-tolerant plants, we designed 13 different DNA ...
Singh Shipra - - 2007
Some novel fluorophores, viz. 6-(6-isobutyrylamino-1,3-dioxo-1H,3H-benzo[de]isoquinolin-2-yl)-hexanoic acid (1), 6-(6-dimethylamino-1,3-dioxo-1H, 3H-benzo[de]isoquinolin-2-yl)-hexanoic acid (2), 6-(6-benzoylamino-1, 3-dioxo-1H, 3H-benzo[de]isoquinolin-2-yl)-hexanoic acid (3), 6-(6-amino-1-oxo-1H, 3H-benzo[de]isoquinolin-2-yl)-hexanoic acid (4) and 6-(6-amino-1H,3H-benzo[de] isoquinolin-2-yl)-hexanoic acid (5) have been designed, synthesized and characterized. Their comparative fluorescence has been studied in different organic solvents and aqueous solutions containing inorganic ions. Out of these, ...
Lim I-Im S - - 2007
This paper reports the findings of an investigation of the reactivity and assembly of gold nanoparticles mediated by homocysteine (Hcys), a thiol-containing amino acid found in plasma. The aim is to gain insight into the interparticle interaction and reactivity, which has potential application for the detection of thiol-containing amino acids. ...
Mendoza Sandra M - - 2007
We report a study of acid-terminated self-assembled monolayers of alkanethiols of different length, 11-mercaptoundecanoic acid (11-MUA) and 16-mercaptohexadecanoic acid (16-MHDA), on Au(111). Scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and contact angle techniques were used for characterization, and the results were compared ...
Levine Howard A - - 2007
Systematic evolution of ligands by exponential enrichment (SELEX) is a procedure by which a mixture of nucleic acids that vary in sequence can be separated into pure components with the goal of isolating those with specific biochemical activities. The basic idea is to combine the mixture with a specific target ...
- - 2007
The Food and Drug Administration (FDA) is classifying quality control material for cystic fibrosis nucleic acid assays into class II (special controls). The special control that will apply to the device is the guidance document entitled "Class II Special Controls Guidance Document: Quality Control Material for Cystic Fibrosis Nucleic Acid ...
Grant Gian Paola G - - 2007
In site-directed spin labeling (SDSL), a nitroxide moiety containing a stable, unpaired electron is covalently attached to a specific site within a macromolecule, and structural and dynamic information at the labeling site is obtained via electron paramagnetic resonance (EPR) spectroscopy. Successful SDSL requires efficient site-specific incorporation of nitroxides. Work reported ...
Gopinath S C B - - 2007
Aptamers are rare nucleic acid ligands, which can be concocted in the laboratory from the randomized pool of molecules by affinity and amplification processes. Aptamers have several properties as they can be applied complementarily to antibodies and have several advantages over antibodies. In the past, several aptamers have been selected ...
Wojciechowski Filip - - 2007
Peptide nucleic acid (PNA) is an oligonucleotide mimic originally designed upon a repeating N-(2-aminoethyl)glycine polyamide backbone to which nucleobase heterocycles are attached through a methylene carbonyl linkage to the alpha-amino group. These molecules possess remarkable hybridization properties with DNA or RNA forming complexes with high stability and with excellent sequence ...
Freistadt Marion S - - 2007
Nucleic acid polymerases have similar structures and motifs. The function of an aspartic acid (conserved in all classes of nucleic acid polymerases) in motif A remains poorly understood in RNA-dependent RNA polymerases. We mutated this residue to alanine in a poliovirus replicon. The resulting mutant could still replicate, although at ...
Obernosterer Gregor - - 2007
Here we describe a method for sensitive and specific histological detection of microRNAs (miRNAs) by in situ hybridization. The protocol focuses on the use of locked nucleic acids (LNAs), which are bi-cyclic RNA analogs that allow a significant increase in the hybridization temperature and thereby an enhanced stringency for short ...
Bozilović Jelena - - 2007
Nucleoside analogues are chemical means to investigate hydrogen bonds, base stacking, and solvation as the three predominant forces that are responsible for the stability of secondary structure of nucleic acids. To obtain deeper insight into the contributions of these interactions to RNA stability apart from the ones exerted by the ...
Fisker Niels - - 2007
We have investigated the effects of different locked nucleic acid modified antisense mRNA antagonists against Survivin in a prostate cancer model. These mRNA antagonists were found to be potent inhibitors of Survivin expression at low nanomolar concentrations. Additionally there was a pronounced synergistic effect when combining the mRNA antagonists against ...
Carter Darren J - - 2007
Widely used nucleic acid assays are poorly suited for field deployment where access to laboratory instrumentation is limited or unavailable. The need for field deployable nucleic acid detection demands inexpensive, facile systems without sacrificing information capacity or sensitivity. Here we describe a novel microarray platform capable of rapid, sensitive nucleic ...
Qu Guirong - - 2007
A simple, rapid, and regioselective approach for the synthesis of N-(methoxy-carbonylmethyl)- and N-(n-propoxycarbonylmethyl) nucleobases was developed. By using DMF as the solvent and in the presence of K2CO3 as the base, all the desired products were obtained in moderate yields within 8 min under microwave irradiation.
Adelfinskaya O - - 2007
Some selected amino acids, in particular L-aspartic acid (L-Asp) and L-histidine (L-His), can function as leaving group during polymerase-catalyzed incorporation of deoxyadenosine monophosphate (dAMP) in DNA. Although L-Asp-dAMP and L-His-dAMP bind, most probably, in a different way in the active site of the enzyme, aspartic acid and histidine can be ...
Ambretti S - - 2007
BACKGROUND: The vast majority of studies aimed at detecting human papillomavirus (HPV) DNA in skin cancer have used sensitive polymerase chain reaction (PCR) methods but the PCR technique, despite its high sensitivity, is not suitable to ascertain whether (i) the presence of HPV can be related only to few cells ...
Kroth Peter - - 2007
Diatoms are unicellular photoautotrophic eukaryotes that play an important role in ecology by fixing large amounts of CO2 in the oceans. Because they evolved by secondary endocytobiosis--a process of uptake of a eukaryotic alga into another eukaryotic cell--they have a rather unusual cell biology and genetic constitution. Diatoms are also ...
Kumar Vaijayanti A - - 2007
The synthesis of backbone-modified nucleic acids has been an area of very intense research over the last two decades. The main reason for this research activity is the instability of nucleic acid based drugs in the intracellular conditions. Changes in the sugar-phosphate backbone invariably bring about the changes in the ...
Pallan Pradeep S - - 2007
This protocol describes a simplified means of introducing an anomalously scattering atom into oligonucleotides by conventional solid-phase synthesis. Replacement of a nonbridging phosphate oxygen in the backbone with selenium is practically suitable for any nucleic acid. The resulting oligonucleotide P-diastereomers can be separated using anion exchange HPLC to yield diastereomerically ...
Al-Mulla Fahd - - 2007
The last decade has witnessed an impressive upsurge in the utilization of microarray platforms for biomedical research. However, the application of this emerging technology in medical practice lagged behind. This lag is understandable because there are specific issues pertaining to the utilization of clinical samples, which has to be rigorously ...
Ganesh Krishna N - - 2007
We herein describe the introduction of gem-dimethyl substitution into the aminoethylglycyl backbone of PNA to impart steric constraint and pre-organise PNA for selective recognition of nucleic acids. Introduction of cyanuric acid and 8-aminoadenine as pyrimidine and purine analogs that can form base pairing from either face is also described to ...
Murtola Merita - - 2007
We have developed 2'-O-methyloligoribonucleotide and peptide nucleic acid (PNA) based artificial ribonucleases (OBAN's), which in presence of zinc or copper ions cleave a potential therapy target in leukemia, an M-BCR/ABL mRNA model. The OBAN's give turnover of substrate and are thus real enzymes. A copper ion based system even gives ...
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