Search results for " Ultraviolet"

Amino acid substitutions enhancing thermostability of Bacillus polymyxa beta-glucosidase A

1996

Mutations enhancing the thermostability of β-glucosidase A of Bacillus polymyxa, a family 1 glycosyl hydrolase, have been obtained after hydroxylamine mutagenesis of a plasmid containing the bglA gene, transformation of Escherichia coli with the mutagenized plasmid, and identification of transformant colonies that showed β-glucosidase activity after a thermal treatment that inactivated the wild-type enzyme. Two additive mutations have been characterized that cause replacement of glutamate at position 96 by lysine and of methionine at position 416 by isoleucine respectively. The thermoresistant mutant enzymes showed increased resistance to other denaturing agents, such as pH and urea, while …

Impulsive solvent heating probed by picosecond x-ray diffraction

2006

The time-resolved diffraction signal from a laser-excited solution has three principal components: the solute-only term, the solute-solvent cross term, and the solvent-only term. The last term is very sensitive to the thermodynamic state of the bulk solvent, which may change during a chemical reaction due to energy transfer from light-absorbing solute molecules to the surrounding solvent molecules and the following relaxation to equilibrium with the environment around the scattering volume. The volume expansion coefficient alpha for a liquid is typically approximately 1 x 10(-3) K(-1), which is about 1000 times greater than for a solid. Hence solvent scattering is a very sensitive on-line t…

Reduction of clozapine-induced hypersalivation by pirenzepine is safe.

2004

Introduction Hypersalivation is known as a frequent, disturbing, and socially stigmatizing side effect of therapy with the atypical antipsychotic clozapine. It has been shown that the addition of the anticholinergic pirenzepine is able to reduce clozapine-induced hypersalivation, probably by blocking M4-receptors. Nevertheless, a pharmacokinetic interaction between both compounds cannot be excluded. Methods In this pilot study, 29 schizophrenic patients (ICD-10; 51.7 % female; age: 36.7 +/- 8.7 years [mean +/- SD]) were included. Serum concentrations of clozapine and its pharmacologically active metabolite N-desmethylclozapine were determined under steady-state conditions by automated HPLC …

Presence and coding properties of 2'-O-methyl-5-carbamoylmethyluridine (ncm5Um) in the wobble position of the anticodon of tRNA(Leu) (U*AA) from brew…

1992

AbstractThe unknown modified nucleoside U* has been isolated by enzymatic and HPLC protocols from tRNALeu(U*AA) recently discovered in brewer's yeast. The pure U* nucleoside has been characterized by electron impact mass spectroscopy, and comparison of its chromatographic and UV-absorption properties with those of appropriate synthetic compounds. The structure of U* was established as 2′-O-methyl-5-carbamoylmethyluridine (ncm5Um). The yeast tRNALeu (U*AA) is the only tRNA so far sequenced which has been shown to contain ncm5Um. The location of such a modified uridine at the first position of the anticodon restricts the decoding property to A of the leucine UUA codon.

Determination of pesticide residues in fruit and vegetables.

1996

A review concerning the determination of pesticide residues in fruit and vegetables is presented. The basic principles and recent developments in the extraction and quantitation of pesticides are discussed. Consideration is given to solid phase and supercritical extraction techniques, automation and robotic systems, and immunoassay procedures.

In vitro evaluation of poloxamer in situ forming gels for bedaquiline fumarate salt and pharmacokinetics following intramuscular injection in rats

2019

Graphical abstract

Automated simultaneous triple dissolution profiles of two drugs, sulphamethoxazole-trimethoprim and hydrochlorothiazide-captopril in solid oral dosag…

2003

This article deals with the simultaneous determination of three dissolution profiles with the aid of the new and emerging continuous-flow methodology known as multicommutation. This methodology is based on a flow network of a set of solenoid valves controlled by the computer and acting as independent multicommutators to allow the easy and automated control of flowing solutions. The obtained three dissolution profiles from one dosage form are the whole formulation profile or "global profile" recommended by pharmacopoeias, and, at same time, are recorded two "individual" profiles from two drugs present in the formulation. This is the second attempt to obtain simultaneously three dissolution p…

Indagine diagnostica non invasiva sul dipinto su tavola l'Annunciata di Antonello da Messina

2007

Photochemical electrocyclisation of 3-vinylindoles to pyrido[2,3-a]-, pyrido[4,3-a]- and thieno[2,3-a]-carbazoles: Design, synthesis, DNA binding and…

2009

In the context of the design and synthesis of DNA ligands, some new hetarene annelated carbazoles were synthesized. As lead structure the intercalating tetracyclic systems pyrido[2,3-a]- and pyrido[4,3-a]-carbazoles and in one case a thieno[2,3-a]-carbazole were taken into account. A dialkyl amino amidic chain was introduced to the planar chromophoric system with the intent to generate minor groove binding properties. The cytotoxicity of some compounds was examined by the NCI antitumor screening. Furthermore, biophysical as well as biochemical studies were performed in order to get some information about the DNA-binding properties and inhibition of DNA related functional enzymes of this new…

Acid Titrations of poly(dG-dC).poly(dG-dC) in Aqueous Solution and in a w/o Microemulsion

2005

The model polynucleotide poly(dG-dC).poly(dG-dC) (polyGC) was titrated with a strong acid (HCl) in aqueous unbuffered solutions and in the quaternary w/o microemulsion CTAB/n-pentanol/n-hexane/water. The titrations, performed at several concentrations of NaCl in the range 0.005 to 0.600 M, were followed by recording the modifications of the electronic absorption and of the CD spectra (210or = lambdaor =350 nm) upon addition of the acid. In solution, the polynucleotide undergoes two acid-induced transitions, neither of which corresponds to denaturation of the duplex to single coil. The first transition leads to the Hoogsteen type synG.C+ duplex, while the second leads to the C+.C duplex. The…