1,046 research outputs found
Gras- und Kleesaaten, Gewinnung und Handel in Dänemark, Grossbritannien und Irland.
No full text[Pt. 1] issued separately as Hollmann. Gras- und Kleesamengewinnung in Dänemark, Stück 19 of Berichte über Land- und Forstwirtschaft im Ausland.[Pt. 1] Gras- und Kleesamengewinnung in Dänemark. Von dr. Hollmann.--[Pt. 2] Klee- und Grassaaten, Gewinnung und Handel in Grossbritannien und Irland. Von dr. Skalweit.Mode of access: Internet
Paramedic versus emergency physician emergency medical service: role of the anaesthesiologist and the European versus the Anglo-American concept
No full textPurpose of review Much controversy exists about who can provide the best medical care for critically ill patients in the prehospital setting. The Anglo-American concept is on the whole to provide well trained paramedics to fulfil this task, whereas in some European countries emergency medical service physicians, particularly anaesthesiologists, are responsible for the safety of these patients. Recent findings Currently there are no convincing level I studies showing that an emergency physician-based emergency medical service leads to a decrease in overall mortality or morbidity of prehospital treated patients, but many methodical, legal and ethical issues make such studies difficult. Looking at specific aspects of prehospital care, differences in short-term survival and outcome have been reported when patients require cardiopulmonary resuscitation, advanced airway management or other invasive procedures, well directed fluid management and pharmacotherapy as well as fast diagnostic-based decisions. Summary Evidence suggests that some critically ill patients benefit from the care provided by an emergency physician-based emergency medical service, but further studies are needed to identify the characteristics and early recognition of these patient
Solvent‐Free Photobiocatalytic Hydroxylation of Cyclohexane
No full textThe use of neat reaction media, that is the avoidance of additional solvents, is the simplest and the most efficient approach to follow in biocatalysis. Here, we show that unspecific peroxygenase from Agrocybe aegerita (AaeUPO) can hydroxylate the neat model substrate cyclohexane. H2O2 was photocatalytically generated in situ by nitrogen-doped carbon nanodots (N−CNDs) and UV LED illumination. AaeUPO entrapment in alginate beads increased enzyme stability and facilitated the reaction in neat cyclohexane. N−CNDs absorption in beads containing AaeUPO created a 2-in-1 heterogeneous photobiocatalyst that was active for up to seven days under reaction conditions and produced cyclohexanol, 2.5 mM. To increase productivity, the bead size and the photocatalyst-to-enzyme ratio have been identified as promising targets for optimisation.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi
Mechanisms of neuro- and cytotoxicity of local anesthetics and their adjuvants
No full textPlaatselijke verdovingsmiddelen zetten een mechanisme in gang waarbij zenuwcellen zichzelf vernietigen. Dit kan leiden tot zenuwschade. Stevens wilde achterhalen hoe die zenuwschade ontstaat. Hij toont aan dat alle gangbare plaatselijke verdovingsmiddelen een soort zelfmoordmechanisme van zenuwcellen in gang zetten. Om de kans op deze schade te beperken, worden plaatselijke verdovingsmiddelen vaak met andere middelen gemengd. Het merendeel van deze middelen is onschadelijk. Stevens spoorde twee middelen op die de zenuwschade verergerden. Het onderzoek is uitgevoerd in celculturen, maar Stevens raadt nu al aan om deze middelen niet bij plaatselijke verdoving te gebruiken
Pro-Con Debate: Do We Need Quantitative Neuromuscular Monitoring in the Era of Sugammadex?
No full textIn this Pro-Con article, we debate the merits of using quantitative neuromuscular blockade monitoring. Consensus guidelines recommend their use to guide the administration of nondepolarizing neuromuscular blockade and reversal agents. A major impediment to this guideline is that until recently, reliable quantitative neuromuscular blockade monitors have not been widely available. Without them, anesthesia providers have been trained with and are adept at using a variety of qualitative neuromuscular blockade monitors otherwise known as peripheral nerve stimulators. Although perhaps less accurate, anesthesia providers find them reliable and easy to use. They have a long track record of using them with the perception that their use leads to effective neuromuscular blockade reversal and minimizes clinically significant adverse events from residual neuromuscular blockade. In the recent past, 2 disruptive developments have called upon anesthesia care providers to reconsider their practice in neuromuscular blockade administration, reversal, and monitoring. These include: (1) commercialization of more reliable quantitative neuromuscular monitors and (2) widespread use of sugammadex, a versatile reversal agent of neuromuscular blockade. Sugammadex appears to be so effective at rapidly and effectively reversing even the deepest of neuromuscular blockades, and it has left anesthesia providers wondering whether quantitative monitoring is indeed necessary or whether conventional, familiar, and less expensive qualitative monitoring will suffice? This Pro-Con debate will contrast anesthesia provider perceptions with evidence surrounding the use of quantitative neuromuscular blockade monitors to explore whether quantitative neuromuscular monitoring (NMM) is just another technology solution looking for a problem or a significant advance in NMM that will improve patient safety and outcomes
Artificial photosynthesis: Hybrid systems
No full textOxidoreductases are promising catalysts for organic synthesis. To sustain their catalytic cycles they require efficient supply with redox equivalents. Today classical biomimetic approaches utilizing natural electron supply chains prevail but artificial regeneration approaches bear the promise of simpler and more robust reaction schemes. Utilizing visible light can accelerate such artificial electron transport chains and even enable thermodynamically unfeasible reactions such as the use of water as reductant. This contribution critically summarizes the current state of the art in photoredoxbiocatalysis (i.e. light-driven biocatalytic oxidation and reduction reactions).Accepted Author ManuscriptBT/Biocatalysi
Biocatalytic C=C Bond Reduction through Carbon Nanodot-Sensitized Regeneration of NADH Analogues
No full textLight-driven activation of redox enzymes is an emerging route for sustainable chemical synthesis. Among redox enzymes, the family of Old Yellow Enzyme (OYE) dependent on the nicotinamide adenine dinucleotide cofactor (NADH) catalyzes the stereoselective reduction of α,β-unsaturated hydrocarbons. Here, we report OYE-catalyzed asymmetric hydrogenation through light-driven regeneration of NADH and its analogues (mNADHs) by N-doped carbon nanodots (N-CDs), a zero-dimensional photocatalyst. Our spectroscopic and photoelectrochemical analyses verified the transfer of photo-induced electrons from N-CDs to an organometallic electron mediator (M) for highly regioselective regeneration of cofactors. Light triggered the reduction of NAD+ and mNAD+s with the cooperation of N-CDs and M, and the reduction behaviors of cofactors were dependent on their own reduction peak potentials. The regenerated cofactors subsequently delivered hydrides to OYE for stereoselective conversions of a broad range of substrates with excellent biocatalytic efficiencies.</p
Stereoselective double reduction of 3-methyl-2-cyclohexenone by use of palladium and platinum nanoparticles in tandem with alcohol dehydrogenase
No full textThe combination of metal nanoparticles (Pd or Pt NPs) with NAD-dependent thermostable alcohol dehydrogenase (TADH) resulted in the one-flask catalytic double reduction of 3-methyl-2-cyclohexenone to 3-(1S,3S)-methylcyclohexanol. In this article some assumptions about the interactions between a chemocatalyst and a biocatalyst have been proposed. It was demonstrated that the size of the NPs was the critical parameter for the mutual inhibition: the bigger the NPs the more harmful for the enzyme they were even if the NPs themselves were only moderately inactivated. Conversely the smaller the NPs the more minimal the TADH denaturation although they were dramatically inhibited. Resuming the chemocatalysts were very sensitive to deactivation which was not related to the amount of enzyme used while the inhibition of the biocatalyst can be strongly reduced by minimizing the NPs/TADH ratio used to catalyze the reaction. Among some methods to avoid direct binding of NPs with TADH we found that using large Pd NPs and protecting their surfaces with a silica shell the overall yield of 3-(1S,3S)-methylcyclohexanol was maximized (36%).BT/Biocatalysi
Natural deep eutectic solvents as performance additives for biocatalysis
No full textFollowing ionic liquids, (natural) deep eutectic solvents ((NA)DES) are receiving significant attention as performance additives for biocatalytic reactions. (NA)DES are increasingly evaluated as solvents to replace water in hydrolase-catalyzed esterification reactions thereby shifting the reaction equilibrium. They also frequently outperform water in terms of solubility properties of hydrophobic reagents and thereby enable higher space-time yields. Furthermore, (NA)DES frequently exceed stabilizing effects on enzymes and thereby enable more robust (and therefore economically more attractive) biocatalytic syntheses. In this contribution, we will summarize and critically evaluate the recent literature on (NA)DES-supported biocatalysis.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.BT/Biocatalysi
- …
