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Getting hooked on flying
The function and consequences of fluorescence in tetrapods
Fluorescence, the optical phenomenon whereby short-wavelength light is absorbed and emitted at longer wavelengths, has been widely described in aquatic habitats, in both invertebrates and fish. Recent years have seen a stream of articles reporting fluorescence, ranging from frogs, platypus, to even fully terrestrial organisms such as flying squirrels, often explicitly or implicitly linking the pre
Arthroscopic Partial Meniscectomy for a Degenerative Meniscus Tear Is Not Cost Effective Compared With Placebo Surgery : An Economic Evaluation Based on the FIDELITY Trial Data
BACKGROUND: In patients with a degenerative tear of the medial meniscus, recent meta-analyses and systematic reviews have shown no treatment benefit of arthroscopic partial meniscectomy (APM) over conservative treatment or placebo surgery. Yet, advocates of APM still argue that APM is cost effective. Giving advocates of APM their due, we note that there is evidence from the treatment of other musc
Covalent Binding of an NAD Analogue to Liver Alcohol Dehydrogenase Resulting in an Enzyme-Coenzyme Complex not Requiring Exogenous Coenzyme for Activity
1. The NAD analogue, N6-[N-(6-aminohexyl)carbamoylmethyl]-NAD, was covalently bound to horse liver alcohol dehydrogenase in a carbodiimide-mediated reaction and in such a way that it was active with the very same enzyme molecule to which it was coupled. 2. The degree of substitution, i.e. the number of NAD analogues per enzyme subunit, could be varied (0.3 - 1.6). In one preparation 1.6 coenzyme m
Steroid Conversion Using Immobilized Living Microorganisms
In steroid transformations some of the advantages of immobilized microorganisms seem to be especially important, since the manufacture of steroid drugs often involves very expensive intermediates and products (1). Therefore, we have been studying two corticosteroid transformations. The first reaction is an 11-β-hydroxylation catalyzed by free or polyacrylamide immobilized Curvularia lunata, pr
Preparation of an Active Soluble Lactate Dehydrogenase-Nicotinamide Adenine Dinucleotide Complex Using Glutaraldehyde
The cofactor analogue N6-((6-aminohexyl)-carbamoylmethyl)-NAD was bound to beef heart lactate dehydrogenase by the glutaraldehyde coupling method and the enzyme-coenzyme complex subsequently separated from excess of non-coupled cofactor by gel filtration chromatography. The number of cofactor molecules bound per enzyme molecule could be varied between 0 and 8 by altering the coupling time. The enz
Synthesis of the bifuncttonal dinucleotide AMP-ATP and its application in general ligand affinity chromatography
A new AMP derivative substituted with spacer arms both at position N6 and C8 of the adenine moiety was synthesized and immobilized to Sepharose. To the immobilized ligand was subsequently coupled C8-substituted ATP in a solid-phase synthesis fashion yielding the bifunctional general ligand AMP-ATP. This affinity material was used in the separation of two major groups of enzymes, dehydrogenases and
The microbe thermistor
WE describe here the development of a new analytical configuration, called a microbe thermistor, in which immobilised microorganisms are placed in proximity to a thermistor which measures the metabolic heat evolved by them. Many metabolites can thus be analysed, as we show here by the determination of both single components such as glucose and fructose and of more complex mixtures such as casein.
New approach to steroid conversion using activated immobilized microorganisms
THE marked increase in demand for contraceptives and anti-inflammatory agents such as cortisol and prednisolone, combined with a diminishing supply of steroid raw materials may lead to shortages of steroid drugs1. Thus it is important to develop new sources for steroids as well as to devise more efficient means for steroid conversions. Here we report a new approach to steroid transformation in whi
Immobilization of steroid-transforming microorganisms in polyacrylamide
Immobilized coenzymes
The Synthesis of Three AMP-Analogues: N6-(6-Aminohexyl)-adenosine 5′-Monophosphate, N6-(6-Aminohexyl)-adenosine 2′,5′-Bisphosphate, and N6-(6-Aminohexyl)-adenosine 3′,5′-Bisphosphate and Their Application as General Ligands in Biospecific Affinity Chromatography
Phosphorylation of 6‐chloropurine riboside with phosphorus oxychloride and phosphorus trichloride gave a mixture of the two isomers, 6‐chloropurine‐riboside 2′,5′‐bisphosphate and 6‐chloropurine‐riboside 3′,5′‐bisphosphate. Reaction with 1,6‐diaminohexane followed by resolution of the isomeric mixture on a Dowex 1‐X2 column yielded N6‐(6‐aminohexyl)‐adenosine 2′,5′‐bisphosphate and N6‐(6‐amin
The preparation and characterisation of a water-soluble coenzymically active dextran-NAD+
A New Immobilized NAD+ Analogue, Its Application in Affinity Chromatography and as a Functioning Coenzyme
Alkylation of NAD+ with iodoacetic acid followed by alkaline rearrangement gave N6-carboxymethyl-NAD+. Condensation of this analogue with 1,6-diaminohexane gave the analogue NAD+- N6-[N-(6-aminohexyl)-acetamide]. The coenzymic activity of the two derivatives was tested with malate dehydrogenase, alcohol dehydrogenase and lactate dehydrogenase. The efficiency relative to unsubstituted NAD+ was i
On Adenine Nucleosides for Affinity Chromatography
Preparation of a NAD(H)-polymer matrix showing coenzymic function of the bound pyridine nucleotide
To a Sepharose gel the pyridine nucleotide NAD(H) has been bound using dicyclohexyl carbodiimide. In order to improve the steric availability of the nucleotide for added soluble enzymes such as dehydrogenases, a spacer molecule, ε-amino caproic acid, was inserted between the carbohydrate matrix and the nucleotide. The obtained preparation contained 56 μmoles NAD+/g dry polymer. The obtained
Superporous Agarose—A New Material for Chromatography
Superporous particles contain two sets of pores, normal diffusion pores and very large flow pores. If such particles are used chromatographically, part of the flow will pass through each particle. This leads to a rapid equilibration between the stationary and the mobile phases, even if the superporous particle has a large outer diameter. Superporous particles are thus chromatographically efficient
Screening for prostate cancer : evidence, ongoing trials, policies and knowledge gaps
Long-term screening with serum prostate-specific antigen (PSA) and systematic prostate biopsies can reduce prostate cancer mortality but leads to unacceptable overdiagnosis. Over the past decade, diagnostic methods have improved and the indolent nature of low-grade prostate cancer has been established. These advances now enable more selective detection of potentially lethal prostate cancer. This n
Introduction—on tools, bit by bit
This thematic issue of the Journal of Digital History focuses on different digital tools that are used to study, explore, and narrate the past. Our idea has been to collect a broad range of articles that demonstrate and critique new ways of exploring the past through computational means—all in order to open up and problematize the use of digital methods in historical research, including analytical