| 1. |
- Petersen, Julian, et al.
(författare)
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A previously uncharacterized Factor Associated with Metabolism and Energy (FAME/C14orf105/CCDC198/1700011H14Rik) is related to evolutionary adaptation, energy balance, and kidney physiology
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- In this study we use comparative genomics to uncover a gene with uncharacterized function (1700011H14Rik/C14orf105/CCDC198), which we hereby name FAME (Factor Associated with Metabolism and Energy). We observe that FAME shows an unusually high evolutionary divergence in birds and mammals. Through the comparison of single nucleotide polymorphisms, we identify gene flow of FAME from Neandertals into modern humans. We conduct knockout experiments on animals and observe altered body weight and decreased energy expenditure in Fame knockout animals, corresponding to genome-wide association studies linking FAME with higher body mass index in humans. Gene expression and subcellular localization analyses reveal that FAME is a membrane-bound protein enriched in the kidneys. Although the gene knockout results in structurally normal kidneys, we detect higher albumin in urine and lowered ferritin in the blood. Through experimental validation, we confirm interactions between FAME and ferritin and show co-localization in vesicular and plasma membranes.
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| 2. |
- Szucs, Edina, et al.
(författare)
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Synthesis, biochemical, pharmacological characterization and in silico profile modelling of highly potent opioid orvinol and thevinol derivatives
- 2020
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Ingår i: European Journal of Medicinal Chemistry. - : ELSEVIER. - 0223-5234 .- 1768-3254. ; 191
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Tidskriftsartikel (refereegranskat)abstract
- Morphine and its derivatives play inevitably important role in the m-opioid receptor (MOR) targeted antinociception. A structure-activity relationship study is presented for novel and known orvinol and thevinol derivatives with varying 3-O, 6-O, 17-N and 20-alkyl substitutions starting from agonists, antagonists and partial agonists. In vitro competition binding experiments with [H-3]DAMGO showed low subnanomolar affinity to MOR. Generally, 6-O-demethylation increased the affinity toward MOR and decreased the efficacy changing the pharmacological profile in some cases. In vivo tests in osteoarthritis inflammation model showed significant antiallodynic effects of thevinol derivatives while orvinol derivatives did not. The pharmacological character was modelled by computational docking to both active and inactive state models of MOR. Docking energy difference for the two states separates agonists and antagonists well while partial agonists overlapped with them. An interaction pattern of the ligands, involving the interacting receptor atoms, showed more efficient separation of the pharmacological profiles. In rats, thevinol derivatives showed antiallodynic effect in vivo. The orvinol derivatives, except for 6-O-desmethyl-dihydroetorfin (2c), did not show antiallodynic effect.
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| 3. |
- Aas, Wenche, et al.
(författare)
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Equilibria and dynamics in binary and ternary uranyl oxalate and acetate/fluoride complexes
- 1999
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Ingår i: Journal of the Chemical Society - Dalton Transactions. - : Royal Society of Chemistry (RSC). - 0300-9246 .- 1364-5447. ; :8, s. 1311-1317
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Tidskriftsartikel (refereegranskat)abstract
- The formation of ternary UO2(ac)pFq2-p-q (p = 1 or 2 and q = 1-3) complexes, and their equilibrium constants were investigated by potentiometric titrations and 19F NMR spectroscopy. The equilibrium constants have been determined from the emf data in a NaClO4 medium at constant sodium concentration, [Na+] = 1.00 M at 25°C, except for the UO2(ac)F32- complex where 19F NMR at -5°C was used. The magnitude of the equilibrium constant for the stepwise addition of fluoride indicates that prior co-ordination of acetate has only a small effect on the subsequent bonding of fluoride. The acetate exchange in the ternary UO2(ac)F32- complex was studied using 19F NMR. Through magnetisation transfer experiments, it was possible to confirm the provisional mechanism from a previous study and also the consistency of the rate constants for the five different exchange pathways required to describe the fluoride exchange. The exchange takes place via the intermediate UO2F3(H2O)2-, indicating that the acetate exchange follows an interchange mechanism with solvent participation in the transition state. The rates and mechanisms of the ligand exchange reactions in UO2(ox)2(H2O)2- and UO2(ac)2(H2O) have been studied using 13C NMR techniques at -5°C. The rate law is v = k-[complex][ligand], and the second order rate constant and the activation parameters for both systems have been determined. The reactions most likely take place through an Eigen-Wilkins type of mechanism, where the first step is a pre-equilibrium of an outer-sphere complex followed by a rate determining exchange of water. The rate constants for the water exchange reactions are very similar to that in UO2(H2O)52+. The information from the binary oxalate system rules out the formation of UO2(ox)2(H2O)2- as an intermediate in the exchange reactions in the previously studied UO2(ox)2F3-, also in this case confirming a previously suggested exchange mechanism. The H+/D+ isotope effects and a linear free energy relationship suggest that the main catalytic effect of H+ on ligand exchange rates is due to the formation of a protonated precursor. Hence, the catalytic effect depends on the basicity of the ligand and the site for the proton attack.
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| 4. |
- Ahn, Henrik Casimir, 1949-, et al.
(författare)
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A New Total Artificial Heart Concept Allowing Replacement or Support of the Native Heart
- 2018
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Ingår i: Journal of Clinical & Experimental Cardiology. - Los Angeles, United States : Omics Publishing Group. - 2155-9880. ; 9:2
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Tidskriftsartikel (refereegranskat)abstract
- A total artificial heart (TAH) is typically used to bridge the time to heart transplantation. A device designed by Robert Jarvik has been improved through the years and under the name of Syncardia™ this has been the most successful commercially available TAH so far. Since 2008 the Carmat™ heart has been under development in Europe. The Scandinavian Real Heart™ is based on a unique physiological concept where the atrio-ventricular valve plane is of utmost importance in the pumping function of the heart. It consists of two identical parts driven separately by independent motors and in this first animal study we have used one part as a left ventricular assist device. This new concept makes the device flexible as it may be used not only as a TAH but also as a separate pump for left or right ventricular assist.
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| 5. |
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| 6. |
- Augustin, Jakob, 1976, et al.
(författare)
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No evidence of genetic benefits from extra-pair fertilisations in female sand martins (Riparia riparia)
- 2007
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Ingår i: Journal of Ornithology. - : Springer Science and Business Media LLC. - 2193-7192 .- 2193-7206. ; 148:2, s. 189-198
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Tidskriftsartikel (refereegranskat)abstract
- Genetic parentage studies of socially monogamous birds reveal a widespread prevalence of extra-pair paternity. Variation in extra-pair paternity among individuals may depend on how different individuals benefit from extra-pair fertilisations and on the opportunity to pursue extra-pair copulations. A long-term study of sand martins (Riparia riparia) in Hungary allowed us to examine patterns of extra-pair fertilisations in a large colony of over 3,000 breeding pairs with many known age individuals. We used multi-locus DNA fingerprinting to determine whether extra-pair fertilisations occur when females are paired to (1) presumably low quality mates, or (2) genetically similar or dissimilar mates, and whether extra-pair fertilisations result in offspring of higher quality. Extra-paternal young were found in 38% of 47 broods and comprised 19% of 190 offspring. Males that lost paternity did not differ significantly from others in age or body condition. Social mates of broods containing extra-pair offspring did not differ in genetic similarity from pairs without extra-pair offspring. Furthermore, there was no significant difference in body condition between extra-pair young and their maternal half-siblings. We were unable to assign paternity and therefore cannot exclude the possibility that extra-pair males differed from the within-pair males they cuckolded, in age, body condition or genetic similarity with the female. We found a positive relationship between paternity losses and breeding density, suggesting that low breeding density may constrain opportunities for seeking extra-pair copulations.
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| 7. |
- Batta, Gy., et al.
(författare)
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C‐19 configurational assignments in some morphine derivatives by homonuclear NOE
- 1992
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Ingår i: Magnetic Resonance in Chemistry. - : Wiley. - 0749-1581 .- 1097-458X. ; 30:13, s. S96-S104
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Tidskriftsartikel (refereegranskat)abstract
- Azidolysis‐thermolysis of C‐19 diastereomer tosyl esters of morphine derivatives resulted in the formation of a new substituted 4‐azatetracyclo [4.4.02,4.03,8] decane ring system. As the course of such transformations depends on the chirality of C‐19, its relative configuration was determined both in the starting materials and in the new compounds. To this end a semiquantitative 1H{1H} NOE interpretation was combined with MMX molecular mechanics. Interestingly, both in the starting materials with a rotating C‐7—C‐19 bond and in the fairly rigid aziridine ring‐containing products, the same (H‐8α{19‐Me}) NOE effects were the most informative on the stereochemistry. In addition full a priori 1H and 13C assignments of 13 compounds are presented.
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| 8. |
- Birch Tyrberg, Rasmus, et al.
(författare)
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Students’ and teachers’ attitudes towards PBL-curriculum components in a medical programme : a follow-up study
- 2021
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Ingår i: MedEdPublish. - : Association for Medical Education in Europe. - 2312-7996. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The aim was to explore students' and teachers' attitudes towards horizontal and vertical integration and other components of the curriculum, and to compare these results with data from a study at our medical school published in 2002.Methods: A questionnaire with 17 questions regarding different components of our curriculum was sent to students and staff at our medical school. They were asked to rate the importance of different components on a Likert scale from 1-6. We compared the answers between the two groups, and also compared them with the results from 2002.Results: Horizontal and vertical integration were rated as very important components (Teachers (n=283) median 5 and 5, Students (n=596) 6 and 5 respectively). Students valued lectures and clinical rotations more highly than teachers. Teachers considered laboratory training, training in searching scientific literature, scientific projects, basic education in ethics, reading and discussion of fictional literature, interprofessional components and examinations as significantly more important than the students did.Conclusions: Attitudes have remained positive towards horizontal and vertical integration despite major changes in the curriculum. The majority of the components of our curriculum were well appreciated, indicating that our curriculum is robust, but some components warrant inspection and possible revision.
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| 9. |
- Bodor, A., et al.
(författare)
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F-19 NMR study of the equilibria and dynamics of the Al3+/F- system
- 2000
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 39:12, s. 2530-2537
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Tidskriftsartikel (refereegranskat)abstract
- A careful reinvestigation by high-field F-19 NMR (470 MHz) spectroscopy has been made of the Al3+/F- system in aqueous solution under carefully controlled conditions of pH, concentration, ionic strength (I), and temperature. The F-19 NMR spectra show five distinct signals at 278 K and I = 0.6 M (TMACl) which have been attributed to the complexes AlFi(3-i)+(aq) with i less than or equal to 5. There was no need to invoke AlFi(OH)(j)((3-i-j)+) mixed complexes in the model under our experimental conditions (pH less than or equal to 6.5), nor was any evidence obtained for the formation of AlF63-(aq) at very high ratios of F-/Al3+. The stepwise equilibrium constants obtained for the complexes by integration of the F-19 signals are in good agreement with literature data given the differences in medium and temperature. In I = 0.6 M TMACl at 278 K and in I = 3 M KCl at 298 K the log K-i values are 6.42, 5.31, 3.99, 2.50, and 0.84 (for species i = 1-5) and 6.35, 5.25, and 4.11 (for species i = 1-3), respectively. Disappearance of the F-19 NMR signals under certain conditions was shown to be due to precipitation. Certain 19F NMR signals exhibit temperature- and concentration-dependent exchange broadening. Detailed line shape analysis of the spectra and magnetization transfer measurements indicate that the kinetics are dominated by F- exchange rather than complex formation. The detected reactions and their rate constants are AlF22+ + *F- reversible arrow AIF*F2+ + F- (k(02) = (1.8 +/- 0.3) x 10(6) M-1 s(-1)), AlF30 + *F- reversible arrow (AlF2F0)-F-* + F- (k(03) = (3.9 +/- 0.9) x 10(6) M-1 s(-1)), and AlF30 + H*F reversible arrow AlF2*F-0 + HF (k(03)(H) = (6.6 +/- 0.5) x 10(4) M-1 s(-1)). The rates of these exchange reactions increase markedly with increasing F- substitution. Thus, the reactions of AlF2+(aq) were too inert to be detected even on the T-1 NMR time scale, while some of the reactions of AlF30(aq) were fast, causing large line broadening. The ligand exchange appears to follow an associative interchange mechanism. The cis-trans isomerization of AlF2+(aq), consistent with octahedral geometry for that complex, is slowed sufficiently to be observed at temperatures around 270 R. Difference between the Al3+/F- system and the much studied Al3+/OH- system are briefly commented on.
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| 10. |
- Chang-Chun, Chen, et al.
(författare)
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Nucleoside transport inhibition mediates lidoflazine-induced cardioprotection during intermittent aortic crossclamping
- 1992
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : Elsevier. - 0022-5223 .- 1097-685X. ; 104:6, s. 1602-1609
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Tidskriftsartikel (refereegranskat)abstract
- The effects of pretreatment with the nucleoside transport inhibitor lidoflazine on repeated ischemia-reperfusion injury induced by normothermic intermittent aortic crossclamping were studied in canine hearts. Eighteen mongrel dogs were allocated to three groups: placebo (n = 6), lidoflazine (1 mg/kg) (n = 6), and lidoflazine (1 mg/kg) plus the adenosine receptor blocker aminophylline (7 mg/kg) (n = 6). Pretreatment was performed intravenously during 15 minutes before extracorporeal circulation. All hearts were subjected to four intervals of 15 minutes of global ischemia each followed by 10 minutes of reperfusion. After weaning from extracorporeal circulation, functional recovery was followed for 1 hour. In the lidoflazine group, myocardial adenosine content (0.25 +/- 0.06 mumol/gm dry weight) was 3.5 times higher than that in the control group (0.07 +/- 0.03 mumol/gm dry weight; p < 0.05) at the end of the last aortic crossclamping. The release of adenosine from the myocardium during each reperfusion period was significantly higher than that in the control group (p < 0.05). Myocardial extraction of lactate was normalized at every reperfusion interval in the lidoflazine group but not in the control group (p < 0.05). In the lidoflazine group functional recovery was significantly better than that in the control group. Positive rate of rise of pressure, negative rate of rise of pressure, and cardiac output recovered to, respectively, 150% +/- 19%, 82% +/- 8%, and 131% +/- 15% in the lidoflazine group versus, respectively, 37% +/- 9%, 23% +/- 7%, and 29% +/- 8% in the control group (p < 0.001) at 1 hour after extracorporeal circulation. When the adenosine receptor blocker aminophylline was administered in association with lidoflazine, protection dropped significantly: positive and negative rate of rise of pressure and cardiac output were, respectively, 58% +/- 8%, 46% +/- 9%, and 67% +/- 16% at 1 hour after extracorporeal circulation (p < 0.05 versus lidoflazine alone). These results suggest that the cardioprotective effects of lidoflazine are at least in part mediated by adenosine receptor stimulation via nucleoside transport inhibition-induced accumulation of endogenous adenosine in the myocardium.
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| 11. |
- Csende, F., et al.
(författare)
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Copper(II) chloride as an efficient reagent for the dehydrogenation of pyridazinone derivatives
- 1995
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Ingår i: Synthesis (Stuttgart). - : Georg Thieme Verlag KG. - 0039-7881 .- 1437-210X. ; :10, s. 1240-1242
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Tidskriftsartikel (refereegranskat)abstract
- A new procedure is described for the preparation of pyridazinones from 4,5-dihydropyridazinones under mild conditions with CuCl2 in MeCN via halogenation and spontaneous HCl elimination. For the trans-hexahydrophthalazin-8(1H)-one 1B*, the HCl elimination is five times faster than for the corresponding cis isomer 1B.
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| 12. |
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| 13. |
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| 14. |
- Csende, F., et al.
(författare)
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Preparation and antiarrhythmic activity of hexahydroisoindol-1-one derivatives
- 1999
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Ingår i: Scientia pharmaceutica. - : MDPI. - 0036-8709 .- 2218-0532. ; 67:2, s. 149-158
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of a series of partially saturated isoindol-1-one from 2- p-toluoyl-cyclohexanecarboxylic acid is described. The compounds were evaluated for their ability to protect against chloroform-induced fibrillation in mice.
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| 15. |
- Csende, F., et al.
(författare)
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Synthesis and structural study of new saturated isoindol-1-one derivatives
- 1993
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Ingår i: Heterocycles. - : The Japan Institute of Heterocyclic Chemistry. - 0385-5414 .- 1881-0942. ; 36:8, s. 1809-1821
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Tidskriftsartikel (refereegranskat)abstract
- Condensation of 2-p-toluoylcyclohexanecarboxylic acid (1a,b) with primary amines gave the corresponding hexahydroisoindol-1-ones (2a-g) in good yield. The octahydro derivatives (4a-g) were prepared from cis- and trans-hexahydro-1(2H)-phthalazinone (3a,b) by reduction with zinc-hydrochloric acid via ring contraction. Stereoselective synthesis of cis-N-phenyloctahydroisoindol-1-one (4h) was performed starting from 2b by reduction with magnesium-methanol at room temperature. Configurational assignments of cis and trans isomers were based on 1H-and 13C-nmr spectroscopic studies.
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| 16. |
- Csende, F., et al.
(författare)
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Synthesis and structural study of novel 1,2-diazepinones and azabicyclooctane derivatives
- 1996
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Ingår i: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 2:5, s. 453-461
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Tidskriftsartikel (refereegranskat)abstract
- Condensation of 3-toluoyl-1,2,2-trimethylcyclopentane-1-carboxylic acid 2 with hydrazine, diamines or 3-aminopropanol afforded the novel bicyclic 1,2-diazepinone 3 or various condensed azabicyclooctane derivatives 4-6, respectively. Further transformations of the 1,2-diazepinone 3 to its perhydro 7 and N-methyl 8 derivatives are also described. Compound 3 when treated with Zn/HC1 resulted in the azabicyclo[3.2.1] octanone derivative 9 by a stereoselective ring contraction. Lactone formation from 3 on treatment with acetic anhydride has also been attempted.
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| 17. |
- Cziáky, Z., et al.
(författare)
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Synthesis of 2H‐pyrano[2,3‐b]quinolines. Part II. Preparation and 1H‐nmr investigations of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines
- 1995
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Ingår i: Journal of Heterocyclic Chemistry. - : Wiley. - 0022-152X .- 1943-5193. ; 32:3, s. 755-760
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Tidskriftsartikel (refereegranskat)abstract
- Diastereoisomers of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines 8 and 9 were synthesized starting from the appropriate 2‐chloroquinoline‐3‐carboxaldehydes 1. The relative configuration of the 1,3‐diol intermediates 4 and 5 was determined on the basis of the 13C‐nmr spectra of their acetonides. The relative stereochemistry of title compounds was confirmed by using homonuclear NOE and selective decoupling experiments, as well as by analysis of the coupling patterns observed in their 1H‐nmr spectra.
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| 18. |
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| 19. |
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| 20. |
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| 21. |
- Farkas, I., et al.
(författare)
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Crystal structure of the sodium salt of the uranyl-oxyacetate-fluoride dimer, Na4(UO2)2(OCH2COO)2F 4 · 6H2O
- 1999
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Ingår i: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 53:11, s. 1009-1012
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Tidskriftsartikel (refereegranskat)abstract
- The structure of the ternary uranyl-oxyacetate-fluoride dimer, (UO2)2(OCH2COO)2F4 4-, was studied by single crystal X-ray diffraction. The space group is P1̄, and the structure contains discrete dimers with a double pentagonal bipyramid geometry, linked by octahedrally coordinated sodium ions. The uranyl ion has a coordination number of five with two fluorides and three oxygens coordinated in a plane perpendicular to the linear UO2 axis. The dimer is formed via bridging oxygen atoms from the deprotonated hydroxyl groups of the glycolate ligands.
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| 22. |
- Farkas, I., et al.
(författare)
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Rates and mechanisms of water exchange of UO22+(aq) and UO2(oxalate)F(H2O)(2)(-) : A variable-temperature O-17 and F-19 NMR study
- 2000
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 39:4, s. 799-805
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Tidskriftsartikel (refereegranskat)abstract
- This study consists of two parts: The first part comprised an experimental determination of the kinetic parameters for the exchange of water between UO2(H2O)(5)(2+) and bulk water, including an ab initio study at the SCF and MP2 levels of the geometry of UO2(H2O)(5)(2+), UO2(H2O)(4)(2+), and UO2(H2O)(6)(2+) and the thermodynamics of their reactions with water. In the second part we made an experimental study of the rate of water exchange in uranyl complexes and investigated how this might depend on inter- and intramolecular hydrogen bond interactions. The experimental studies, made by using O-17 NMR, with Tb3+ as a chemical shift reagent, gave the following kinetic parameters at 25 degrees C: k(ex) = (1.30 +/- 0.05) x 10(6) s(-1); Delta H double dagger = 26.(1) +/- 1.(4) kJ/mol; Delta S double dagger = -40 +/- 5 J/(K mol). Additional mechanistic indicators were obtained from the known coordination geometry of U(VI) complexes with unidentate ligands and from the theoretical calculations. A survey of the literature shows that there are no known isolated complexes of UO22+ with unidentate ligands which have a coordination number larger than 5. This was corroborated by quantum chemical calculations which showed that the energy gains by binding an additional water to UO2(H2O)(4)(2+) and UO2(H2O)(5)(2+) are 29.8 and -2.4 kcal/mol, respectively. A comparison of the change in Delta U for the reactions UO2(H2O)(5)(2+) --> UO2(H2O)(4)(2+) + H2O and UO2(H2O)(5)(2+) + H2O --> UO2(H2O)(6)(2+) indicates that the thermodynamics favors the second (associative) reaction in gas phase at 0 K, while the thermodynamics of water transfer between the first and second coordination spheres, UO2(H2O)(5)(2+) --> UO2(H2O)(4)(H2O)(2+) and UO2(H2O)(5)(H2O)(2+) --> UO2(H2O)(6)(2+), favors the first (dissociative) reaction. The energy difference between the associative and dissociative reactions is small, and solvation has to be included in ab initio models in order to allow quantitative comparisons between experimental data and theory. Theoretical calculations of the activation energy were not possible because of the excessive computing time required. On the basis of theoretical and experimental studies, we suggest that the water exchange in UO2(H2O)(5)(2+) follows a dissociative interchange mechanism. The rates of exchange of water in UO2(oxalate)F(H2O)(2-) (and UO2(oxalate)F-2(H2O)(2-) studied previously) are much slower than in the aquation, k(ex) = 1.6 x 10(4) s(-1), an effect which we assign to hydrogen bonding involving coordinated water and fluoride. The kinetic parameters for the exchange of water in UO2(H2O)(5)(2+) and quenching of photo excited *UO2(H2O)(5)(2+) are very near the same, indicating similar mechanisms.
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| 23. |
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| 24. |
- Fischer, Andreas, et al.
(författare)
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Sodium pentafluorouranate(IV) monohydrate, Na[UF5]center dot H2O
- 2004
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Ingår i: Acta Crystallographica Section E. - : International Union of Crystallography (IUCr). - 1600-5368. ; 60, s. I45-I46
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Tidskriftsartikel (refereegranskat)abstract
- Na[UF5]·H2O crystallizes in the orthorhombic space group Pbcn. It contains a uranium(IV) ion, which is coordinated by nine F- ions yielding a tricapped trigonal prism. Some of the F - ions function as bridging ligands coordinating to the Na + ion. The latter is coordinated by four F- ions. Together with two molecules of water of crystallization, a distorted octahedral coordination around Na+ is obtained.
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| 25. |
- Fjellander, Ester, 1982-, et al.
(författare)
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Atropoisomerism in Phosphepines and Azepines
- 2009
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Ingår i: Journal of Organic Chemistry. - Washington DC : American Chemical Society. - 0022-3263 .- 1520-6904. ; 74:23, s. 9120-9125
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Tidskriftsartikel (refereegranskat)abstract
- Free energy barriers to biaryl tropoinversion in metal complexes with tropos phosphepine and azepine ligands were determined by temperature-dependent P-31 NMR inversion-transfer experiments and line shape analysis of the temperature-dependent H-1 NMR spectra, respectively. The barrier in the PdCl2 complex of the azepine ligand was found to be slightly higher than that of the corresponding free ligand. Studies of a tridentate azepine ligand Suggested that Configurational change takes place without prior decoordination from the metal.
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| 26. |
- Forsell, Claes, et al.
(författare)
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Preoperative Topical Hypothermia used in Prolonged Severe Lower Limb Ischemia to Avoid Ischemic Damage - The First Clinical Experience
- 2013
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Ingår i: International Journal of Biomedical Science. - 1550-9702 .- 1555-2810. ; 9:3, s. 181-184
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Tidskriftsartikel (refereegranskat)abstract
- Severe lower limb ischemia TASC IIB/III with sensory and motor neurologic deficiencies leads to prolonged hospital care, amputation, and death in 20-70 % of cases. We present our first clinical experience of the use of preoperative topical hypothermia to improve muscular viability in these patients. Two hours after onset of symptoms, six 4-liter plastic bags were filled with snow and packed against the ischemic leg which was protected from frost injury by a layer of towels. After surgical revascularization four hours later muscular and neural functions in the leg were completely restored. A maximum serum myoglobin of 6500 ng/L (median 12000 ng/L in similar but untreated patients) postoperatively decreased to 1400 ng/L after 27 hours.
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| 27. |
- Gaipov, Abduzhappar, et al.
(författare)
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Acute kidney injury following coronary revascularization procedures in patients with advanced CKD.
- 2019
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 34:11, s. 1894-1901
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous studies reported that compared with percutaneous coronary interventions (PCIs), coronary artery bypass grafting (CABG) is associated with a reduced risk of mortality and repeat revascularization in patients with mild to moderate chronic kidney disease (CKD) and end-stage renal disease (ESRD). Information about outcomes associated with CABG versus PCI in patients with advanced stages of CKD is limited. We evaluated the incidence and relative risk of acute kidney injury (AKI) associated with CABG versus PCI in patients with advanced CKD.Methods: We examined 730 US veterans with incident ESRD who underwent a first CABG or PCI up to 5 years prior to dialysis initiation. The association of CABG versus PCI with AKI was examined in multivariable adjusted logistic regression analyses.Results: A total of 466 patients underwent CABG and 264 patients underwent PCI. The mean age was 64 ± 8 years, 99% were male, 20% were African American and 84% were diabetic. The incidence of AKI in the CABG versus PCI group was 67% versus 31%, respectively (P < 0.001). The incidence of all stages of AKI were higher after CABG compared with PCI. CABG was associated with a 4.5-fold higher crude risk of AKI {odds ratio [OR] 4.53 [95% confidence interval (CI) 3.28-6.27]; P < 0.001}, which remained significant after multivariable adjustments [OR 3.50 (95% CI 2.03-6.02); P < 0.001].Conclusion: CABG was associated with a 4.5-fold higher risk of AKI compared with PCI in patients with advanced CKD. Despite other benefits of CABG over PCI, the extremely high risk of AKI associated with CABG should be considered in this vulnerable population when deciding on the optimal revascularization strategy.
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| 28. |
- Gaipov, Abduzhappar, et al.
(författare)
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Predialysis coronary revascularization and postdialysis mortality
- 2019
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Ingår i: Journal of Thoracic and Cardiovascular Surgery. - : MOSBY-ELSEVIER. - 0022-5223 .- 1097-685X. ; 157:3, s. 976-
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: Coronary artery bypass grafting (CABG) is associated with better survival than percutaneous coronary intervention (PCI) in patients with mild-to-moderate chronic kidney disease (CKD) and end-stage renal disease (ESRD). However, the optimal strategy for coronary artery revascularization in patients with advanced CKD who transition to ESRD is unclear. Methods: We examined a contemporary national cohort of 971 US veterans with incident ESRD who underwent first CABG or PCI up to 5 years before dialysis initiation. We examined the association of a history of CABG versus PCI with all-cause mortality following transition to dialysis using Cox proportional hazards models adjusted for time between procedure and dialysis initiation, sociodemographics, comorbidities, and medications. Results: In total, 582 patients underwent CABG and 389 patients underwent PCI. The mean age was 64 +/- 8 years, 99% of patients were male, 79% were white, 19% were African American, and 84% had diabetes. The all-cause post-dialysis mortality rates after CABG and PCI were 229 per 1000 patient-years (95% confidence interval [CI], 205-256) and 311 per 1000 patient years (95% CI, 272-356), respectively. Compared with PCI, patients who underwent CABG had 34% lower risk of death (multivariable adjusted hazard ratio, 0.66; 95% CI, 0.51-0.86, P = .002) after initiation of dialysis. Results were similar in all subgroups of patients stratified by age, race, type of intervention, presence/absence of myocardial infarction, congestive heart failure, and diabetes. Conclusions: CABG in patients with advanced CKD was associated lower risk of death after initiation of dialysis compared with PCI.
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| 29. |
- Giesecke, Marianne, et al.
(författare)
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The protonation state and binding mode in a metal coordination complex from the charge measured in solution by electrophoretic NMR
- 2013
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Ingår i: Analytical Methods. - : Royal Society of Chemistry (RSC). - 1759-9660 .- 1759-9679. ; 5:7, s. 1648-1651
-
Tidskriftsartikel (refereegranskat)abstract
- We measured with high accuracy the effective charge of a uranium (VI)-AMP complex by electrophoretic NMR (eNMR). Using the same method, the degree of counterion association is also assessed which leads to a quantitative determination of the nominal charge which then provides the degree of ligand deprotonation in the complex. This demonstrates a new application of eNMR for resolving structural details of supramolecular complexes.
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| 30. |
- Grams, Morgan, et al.
(författare)
-
Decline in Estimated Glomerular Filtration Rate After Acute Kidney Injury: A Surrogate Endpoint?
- 2015
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Ingår i: ASN (American Society of Nephrology).
-
Konferensbidrag (refereegranskat)abstract
- Background: Often a transient condition, acute kidney injury (AKI) is not currently accepted as an endpoint for drug registration trials by the US FDA. We sought to determine whether an intermediate-term change in eGFR after AKI has a sufficiently strong relationship with subsequent ESRD to serve as an alternative endpoint in clinical trials of AKI preventionand/or treatment.Methods: We evaluated 161,185 US veterans who underwent major surgery between2004-2011. Post-surgical AKI was defined by the KDIGO creatinine criteria;decline in eGFR was calculated from pre-hospitalization value to two time-points post-discharge (60-days, 90-days) and related to ESRD and mortality using Cox proportional hazards regression.Results: In-hospital mortality varied by AKI status, ranging from 1% for patients without AKI to 35% for those with dialysis-requiring AKI. An eGFR decline of ³30% at 60-days was relatively frequent: 2.5%, 9.7%, 17.2%, and 28.6% in those with no AKI, Stage 1 AKI, Stage 2 AKI, and Stage 3 AKI, respectively. There was a graded relationship between eGFR decline at 60-days and risk of ESRD in persons both with and without AKI (Figure). Compared to stable eGFR/no in-hospital AKI, the adjusted hazard ratio (HR) of ESRD associated with a 30% decline at 60-days after AKI was 6.42 (95% CI: 4.8-8.7). Risks for mortality associated with eGFR decline were smaller: the HR for 30% decline 60-days after in-hospital AKI was 1.59 (95% CI: 1.46-1.73). Risk relationships were similar at 90-days.Conclusions: A 30% decline in eGFR from pre-hospitalization baseline to 60-days or 90-days after an episode of AKI may be an acceptable surrogate endpoint in trials of AKI prevention and/or treatment.
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| 31. |
- Grams, Morgan E, et al.
(författare)
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Acute Kidney Injury After Major Surgery : A Retrospective Analysis of Veterans Health Administration Data.
- 2016
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Ingår i: American Journal of Kidney Diseases. - : Saunders Elsevier. - 0272-6386 .- 1523-6838. ; 67:6, s. 872-880
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Few trials of acute kidney injury (AKI) prevention after surgery have been conducted, and most observational studies focus on AKI following cardiac surgery. The frequency of, risk factors for, and outcomes after AKI following other types of major surgery have not been well characterized and may present additional opportunities for trials in AKI.STUDY DESIGN: Observational cohort study.SETTING & PARTICIPANTS: 3.6 million US veterans followed up from 2004 to 2011 for the receipt of major surgery (cardiac; general; ear, nose, and throat; thoracic; vascular; urologic; and orthopedic) and postoperative outcomes.FACTORS: Demographics, health characteristics, and type of surgery.OUTCOMES: Postoperative AKI defined by the KDIGO creatinine criteria, postoperative length of stay, end-stage renal disease, and mortality.RESULTS: Postoperative AKI occurred in 11.8% of the 161,185 major surgery hospitalizations (stage 1, 76%; stage 2, 15%, stage 3 [without dialysis], 7%; and AKI requiring dialysis, 2%). Cardiac surgery had the highest postoperative AKI risk (relative risk [RR], 1.22; 95% CI, 1.17-1.27), followed by general (reference), thoracic (RR, 0.92; 95% CI, 0.87-0.98), orthopedic (RR, 0.70; 95% CI, 0.67-0.73), vascular (RR, 0.68; 95% CI, 0.64-0.71), urologic (RR, 0.65; 95% CI, 0.61-0.69), and ear, nose, and throat (RR, 0.32; 95% CI, 0.28-0.37) surgery. Risk factors for postoperative AKI included older age, African American race, hypertension, diabetes mellitus, and, for estimated glomerular filtration rate < 90mL/min/1.73m(2), lower estimated glomerular filtration rate. Participants with postoperative AKI had longer lengths of stay (15.8 vs 8.6 days) and higher rates of 30-day hospital readmission (21% vs 13%), 1-year end-stage renal disease (0.94% vs 0.05%), and mortality (19% vs 8%), with similar associations by type of surgery and more severe stage of AKI relating to poorer outcomes.LIMITATIONS: Urine output was not available to classify AKI; cohort included mostly men.CONCLUSIONS: AKI was common after major surgery, with similar risk factor and outcome associations across surgery type. These results can inform the design of clinical trials in postoperative AKI to the noncardiac surgery setting.
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| 32. |
- Grams, Morgan E, et al.
(författare)
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Candidate Surrogate End Points for ESRD after AKI
- 2016
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Ingår i: Journal of the American Society of Nephrology. - : American Society of Nephrology. - 1046-6673 .- 1533-3450. ; 27:9, s. 2851-2859
-
Tidskriftsartikel (refereegranskat)abstract
- AKI, a frequently transient condition, is not accepted by the US Food and Drug Association as an end point for drug registration trials. We assessed whether an intermediate-term change in eGFR after AKI has a sufficiently strong relationship with subsequent ESRD to serve as an alternative end point in trials of AKI prevention and/or treatment. Among 161,185 United States veterans undergoing major surgery between 2004 and 2011, we characterized in-hospital AKI by Kidney Disease Improving Global Outcomes creatinine criteria and decline in eGFR from prehospitalization to postdischarge time points and quantified associations of these values with ESRD and mortality over a median of 3.8 years. An eGFR decline of ≥30% at 30, 60, and 90 days after discharge occurred in 3.1%, 2.5%, and 2.6%, of survivors without AKI and 15.9%, 12.2%, and 11.7%, of survivors with AKI. For patients with in-hospital AKI compared with those with no AKI and stable eGFR, a 30% decline in eGFR at 30, 60, and 90 days after discharge demonstrated adjusted hazard ratios (95% confidence intervals) of ESRD of 5.60 (4.06 to 7.71), 6.42 (4.76 to 8.65), and 7.27 (5.14 to 10.27), with corresponding estimates for 40% decline in eGFR of 6.98 (5.21 to 9.35), 8.03 (6.11 to 10.56), and 10.95 (8.10 to 14.82). Risks for mortality were smaller but consistent in direction. A 30%-40% decline in eGFR after AKI could be a surrogate end point for ESRD in trials of AKI prevention and/or treatment, but additional trial evidence is needed.
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| 33. |
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| 34. |
- Hejjel, L., et al.
(författare)
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Alternatives to heart transplantation
- 1997
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Ingår i: Orvosi Hetilap. - : Akademiai Kiado Rt.. - 0030-6002 .- 1788-6120. ; 138:18, s. 1107-1111
-
Tidskriftsartikel (refereegranskat)
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| 35. |
- Heldbjerg, Henning, et al.
(författare)
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Contrasting population trends of common starlings (Sturnus vulgaris) across Europe
- 2019
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Ingår i: Ornis Fennica. - 0030-5685. ; 96:4, s. 153-168
-
Tidskriftsartikel (refereegranskat)abstract
- The greatest loss of biodiversity in the EU has occurred on agricultural land. The Common Starling (Sturnus vulgaris) is one of the many numerous and widespread European farmland breeding bird species showing major population declines linked to European agricultural intensification. Here we present results based on monitoring data collected since 1975 in 24 countries to examine the influence of changing extent of grassland and cattle abundance (based on results of earlier studies showing the importance of lowland cattle grazed grassland for the species), wintering provenance and temperature on national breeding population trends of Starlings across Europe. Positive Starling population trends in Central-East Europe contrast with negative trends in North and West Europe. Based on this indicative approach, we found some support for the importance of cattle stock and no support for grassland, temperature or wintering provenance to explain Starling population trends in Europe. However, we acknowledge such a European-wide analysis may conceal regional differences in responses and suggest that currently accessible national land use data might be insufficient to describe the detailed current changes in animal husbandry and grassland management that may be responsible for changes in food availability and hence breeding Starling abundance and their differences across Europe. Reviewing results from local studies relating Starling population trends to local agricultural change offer contradictory results, suggesting complex interacting processes at work. We recommend combining national datasets on demography, land-use/agricultural practices and from autecological research to better explain the reasons for contrasting Starling trends across Europe, to enable us to predict how changing agriculture will affect Starlings and potentially suggest mitigation measures to restore local populations where possible.
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| 36. |
- Holm, Jonas, 1971-, et al.
(författare)
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Biomarker dynamics in cardiac surgery: a prospective observational study on MR-proADM, MR-proANP, hs-CRP and sP-selectin plasma levels in the perioperative period
- 2020
-
Ingår i: Biomarkers. - : TAYLOR & FRANCIS LTD. - 1354-750X .- 1366-5804. ; 25:3, s. 296-304
-
Tidskriftsartikel (refereegranskat)abstract
- Background: For many biomarkers in cardiac surgery, there is a lack of knowledge regarding the normal dynamics of plasma levels during the perioperative course. The aim of this study was to investigate the perioperative dynamics of MR-proADM, MR-proANP, hs-CRP and sP-selectin in cardiac surgery. Method: A prospective observational pilot study with 20 patients scheduled for open cardiac surgery procedures with cardiopulmonary bypass (CPB). Plasma samples were taken for each patient and biomarker during the pre-, per- and postoperative period until Day 6 postoperatively. Results: MR-proADM increased significantly from 0.62 [IQR; 0.54-0.93] nmol/L preoperatively to 1.20 [1.04-1.80] nmol/L postoperative Day 1. MR-proANP increased significantly from 125 [77-152] pmol/L preoperatively to 198 [168-307] pmol/L on weaning from CPB. hs-CRP increased significantly from 2.5 mg/L [0.4-12] preoperatively to peak at 208 mg/L [186-239] postoperative Day 3. The preoperative level of sP-selectin at 23.0 [21.3-26.3] ng/mL initially fell at weaning from CPB, followed by a significant peak of 25.5 [22.7-27.7] ng/mL 8 h postoperatively. Conclusions: The findings in this study may help to understand the physiology of the biomarkers analysed and their response to cardiac surgical trauma including CPB. Furthermore, these findings will guide us in further research on the clinical usefulness of these biomarkers.
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| 37. |
- Holm, Jonas, 1971-, et al.
(författare)
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Copeptin Release in Cardiac Surgery : A New Biomarker to Identify Risk Patients?
- 2018
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Ingår i: Journal of Cardiothoracic and Vascular Anesthesia. - : Saunders Elsevier. - 1053-0770 .- 1532-8422. ; 32:1, s. 245-250
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To describe the dynamics of copeptin in open cardiac surgery during the perioperative course.DESIGN: Prospective cohort study.SETTING: Single tertiary hospital.PARTICIPANTS: Twenty patients scheduled for open cardiac surgery procedures with cardiopulmonary bypass (CPB).INTERVENTIONS: No intervention.MEASUREMENTS AND MAIN RESULTS: Copeptin concentrations were measured pre-, peri-, and postoperatively until day 6 after surgery. Patients were analyzed as a whole cohort (n = 20) and in a restricted "normal cohort" consisting of patients with normal preoperative copeptin concentration (<10 pmol/L) and perioperative uneventful course (n = 11). In the whole cohort, preoperative copeptin concentration was 7.0 pmol/L (interquartile range: 3.1-11 pmol/L). All patients had an early rise of copeptin, with 80% having peak copeptin concentration at weaning from CPB or upon arrival in the intensive care unit. Patients in the "normal cohort" had copeptin concentration at weaning from CPB of 194 pmol/L (98-275), postoperative day 1, 27 pmol/L (18-31); and day 3, 8.9 pmol/L (6.3-12).CONCLUSIONS: Regardless of cardiac surgical procedure and perioperative course, all patients had an early significant rise of copeptin concentrations, generally peaking at weaning from CBP or upon arrival in the intensive care unit. Among patients with normal copeptin concentration preoperatively and uneventful course, the postoperative copeptin concentrations decreased to normal values within 3-to-4 days after cardiac surgery. Furthermore, the restricted "normal cohort" generally tended to display lower levels of copeptin concentration postoperatively. Further studies may evaluate whether copeptin can be a tool in identifying risk patients in cardiac surgery.
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| 38. |
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| 39. |
- Irvine, Joe, et al.
(författare)
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Innovation Strategy Development For Remote, Rural And Less Favoured Regions
- 2014
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Ingår i: Practitioners Proceedings 2014 University-IndustryInteraction Conference. - 9789491901126 ; , s. 51-70
-
Konferensbidrag (refereegranskat)abstract
- This paper addresses the development of strategies to increase innovation in remote rural and less favouredregions. Many of the strategies aimed at developing innovation emanates from policy makers incentrally located urban conurbations and are assumed to be universally applicable. An example is thetriple helix model for economic development based around the idea of universities, business and publicsector organisations all coming together to foster innovation and economic prosperity.In many remote, rural and less-favoured localities there may not be a university or other knowledgeintensiveinstitution present. In fact, in some areas the public sector may also be weak and there may noteven be many local businesses operating. In those areas the social and community groups play the dominantrole.Therefore how can appropriate innovation strategies and policies be developed for remote, rural and lessfavoured regions that fully meet the needs of those areas? This question was addressed by theUNICREDS project.UNICREDS was an EU INTERREG IVC funded project including partners from remote, rural and lessfavoured regions from across the EU including the UK, Scandinavia and central Europe. The approachtaken by the project included assessments, a survey and reviews of best practice. This produced a largenumber of case studies and a wealth of insightful data on how innovation works in these regions andsuggested a new approach for future policy development in these regions.The main conclusion was that a one size fits all strategy for innovation is not effective for those regionswhose innovation system is not well advanced. For these areas much greater effort is required by policymakers to introduce locally developed processes and mechanisms that better reflect the needs of the majorregional stakeholders. Moreover, cultural and organisational innovations are also required within eachstakeholder to ensure a more effective contribution is made by universities to regional innovation processes.A new model aimed at assisting policy makers to develop innovation strategies for remote, rural and lessfavoured areas is also described.
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| 40. |
- Johansson, A., et al.
(författare)
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The solution thermolysis approach to molybdenum(V) alkoxides : synthesis, solid state and solution structures of the bimetallic alkoxides of molybdenum(V) and niobium(V), tantalum(V) and tungsten(VI)
- 2000
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Ingår i: Journal of the Chemical Society-Dalton Transactions. - : Royal Society of Chemistry (RSC). - 0300-9246 .- 1470-479X .- 1364-5447. ; :3, s. 387-394
-
Tidskriftsartikel (refereegranskat)abstract
- No complex formation can be observed between molybdenum(VI) oxoalkoxides and the alkoxides of niobium(V) or tantalum(V) at room temperature. The bimetallic derivatives of molybdenum(V), Mo4M2O8((OPr)-Pr-i)(14), where M=Nb 1 and Ta 2, were instead isolated on cooling from the solutions of the isopropoxides in toluene subjected to a short-time reflux. The X-ray single crystal study showed both 1 and 2 to be built of ((PrO)-Pr-i)(3)M(mu-(OPr)-Pr-i)(3)MoO(mu-O)(2)MoO(mu-(OPr)-Pr-i)(2)MoO(mu-O)(2)MoO(mu-(OPr)-Pr-i)(3)M((OPr)-Pr-i)(3) non-linear chain molecules with 2 Mo-Mo bonds (2.5836(8) Angstrom) and short but non-bonding Mo-M distances (3.1791(8) Angstrom for 1 and 3.1746(8) Angstrom for 2). According to NMR and EXAFS data this structure becomes very fluxional or might even be partially broken into homometallic components in hydrocarbon solutions. The oxidation of 2 with traces of oxygen leads to the formation of Mo3Ta2O8((OPr)-Pr-i)(10) 3. Compound 3 can be isolated in a pure form from the reaction of MoO((OPr)-Pr-i)(4) with Ta((OPr)-Pr-i)(4)(OMe) 6: the presence of methoxide ligands leads to the formation of additional oxoligands via non-reductive thermolysis leading to the formation of a (CH3)(2)C(OMe)(2) ketal as organic byproduct. The molecules of 3 are 5-member rings with a MoO(mu-O)(2)MoO fragment in the basis (Mo-Mo 2.5730(13) Angstrom), coupled to two (mu-(OPr)-Pr-i)(2)Ta((OPr)-Pr-i)(3) fragments that are joined together by an oxomolybdate ligand (mu-O)(2)MoO2. According to NMR-spectroscopic data the aggregate is preserved and rigid in solution. Mo4Ta4O16((OPr)-Pr-i)(12) 4 was found to be one of the products of complete oxidation of 2 (and 3) on prolonged contact with dry oxygen. The thermal treatment of the solutions of MoO((OPr)-Pr-i)(4) and WO((OPr)-Pr-i)(4) in toluene yields (Mo4O8)-O-V(Mo,W)O-VI(2)2((OPr)-Pr-i)(12) 5 with a molecular structure very close to its homometallic analog Mo6O10((OPr)-Pr-i)(12). The complete X-ray single crystal study was carried out for the sample of 5 with (Mo4O8)-O-V(Mo0.45W0.55)O-VI(2)2((OPr)-Pr-i)(12) composition.
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| 41. |
- Kálai, T., et al.
(författare)
-
Synthesis and reactions of new nitronyl nitroxides
- 1997
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Ingår i: Synthesis (Stuttgart). - : Georg Thieme Verlag KG. - 0039-7881 .- 1437-210X. ; 1997:09, s. 1049-1055
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Tidskriftsartikel (refereegranskat)abstract
- Various new 2-substituted 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-yloxyl 3-oxide mono- 1b, 7, 13a,b, 14, 15, 16, 17, 22 and biradicals 8, 9 were prepared. The nitronyl nitroxide functions were selectively reduced by Fe/HOAc to 1-hydroxyimidazoline derivatives 3b, 11, 21. The reductions by Zn/HCl led to imidazolines 4, 12. The nitronyl nitroxide functions remained inert when the 2-phenyl compound was nitrated by H2SO4/HNO3 to give nitrophenyl nitronyl nitroxide derivatives 13a,b, 14.
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| 42. |
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| 43. |
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| 44. |
- Karalius, Antanas, et al.
(författare)
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Control Over Emergent π-π-Interactions in Double-Dynamic Coordination Complexes Through a Nature-Inspired Coordination-Triggered System
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A complex self-assembly system based on coordination of dynamic imine/hemiacetal ligands isdemonstrated. Natural dipicolinic acid complexes are considered intercalants of certain bacterialDNA and implicated in thermal resistance of the dormant cell, and 6-formyl-2-picolinate was usedas building block. The dipicolinate-mimicking system showed an emergent and preferentialdynamic, drawbridge-style, π-π interaction effect to the opposing meridional ligand in octahedralcomplexes. The interactions proved to be influenced by the ligand net charge, the bridging arylgroup substitution, and the coordinating metal charge. The application scope of the effect isdiscussed.
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| 45. |
- Karalius, Antanas, et al.
(författare)
-
Formation and Out-of-Equilibrium, High/Low State Switching of a Nitroaldol Dynamer in Neutral Aqueous Media
- 2020
-
Ingår i: Angewandte Chemie International Edition. - : Wiley-VCH Verlag. - 1433-7851 .- 1521-3773. ; 59:9, s. 3434-3438
-
Tidskriftsartikel (refereegranskat)abstract
- The nitroaldol reaction is demonstrated as an efficient dynamic covalent reaction in phosphate buffers at neutral pH. Rapid equilibration was recorded with pyridine-based aldehydes, and dynamic oligomerization could be achieved, leading to nitroaldol dynamers of up to 17 repeating units. The dynamers were applied in a coherent stimuli-responsive molecular system in which larger dynamers transiently existed out-of-equilibrium in a neutral aqueous system rich in formaldehyde, controlled by nitromethane.
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| 46. |
- Karalius, Antanas, et al.
(författare)
-
Interdependent, Dynamic Nitroaldol and Stereoselective Boronic Ester Reactions for Complex Dynamers of Different Topologies
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Dynamic systems based on interdependent nitroaldol and boronic ester reactions have beendemonstrated. In aprotic solvents, nitroalkane-1,3-diols generated by the nitroaldol reaction weresusceptible to ester formation with different boronic acids, leading to significant stabilization of theadducts under basic conditions. Hydrolysis of the boronic esters occurred in the presence of water.The boronic ester formation was stereoselective as established using diastereomericnitroalkanediols. The use of bifunctional building blocks was furthermore established, allowing formain chain nitroaldol-boronate dynamers as well as complex dynamers with distinct topologies. Theshape and rigidity of the resulting dynamers showed apparent dependency on the configuration ofthe boronic acids.
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| 47. |
- Karalius, Antanas, et al.
(författare)
-
Rapidly Exchanging, Double-Dynamic, Catalyst-Free Nitroaldol-Hemiacetal Systems for Metal-Responsive Reversible Polymerization
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A spontaneous, catalyst-free, reversible nitroaldol reaction is reported. The reaction wasused to create dynamic systems and to evaluate their scope and applicability. The thermodynamicand kinetic properties of the reaction were estimated, showing substantial solvent effects andatypical behavior regarding fluctuations and conversion overshoots. This was especially the casewhere the dynamic process was coupled with hemiacetal formation. Multifunctional building blockswere furthermore explored to generate responsive molecular systems, where zinc-coordinationcould be used to downregulate the nitroaldol reaction through the amplification of a dihemiacetalspecies. The systems were also extended to dynamic oligomer formation, where the molecularweight could be predictably upregulated by concentration increase and downregulated throughmetal coordination-induced amplification.
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| 48. |
- Karalius, Antanas
(författare)
-
Responsive Molecular Systems through Dynamic Covalent Chemistry
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Nature tends to inspire research in chemistry. Systems that emerge from molecules interacting via reaction networks is something that life has mastered over the course of evolution in order to produce complexity. Dynamic reactions are key in systems chemistry, where reaction networks give rise to complex, emergent behavior. This thesis aims to harness a special feature of selected dynamic reaction systems – responsiveness.The first chapter of this thesis introduces dynamic covalent chemistry and a general approach to create simple reaction networks by connecting dynamic covalent reactions. Concepts in systems chemistry are introduced in terms of network topology, responsiveness and non-equilibrium processes, while drawing parallels to natural systems.The second chapter explores the potential of the nitroaldol reaction for dynamic systems. Nitroaldol reactions are demonstrated for dynamic polymerization as well as formaldehyde-responsive breakdown of dynamic polymers. The simultaneous formation and breakdown of polymers create emergent non-equilibrium behavior. Furthermore, nitroaldol produced-diols are used in boronate ester formation. This reactivity produces interdependence over two reactions. Combining nitroaldol and boronate building blocks enabled boronate dynamers of different topology.The third chapter explores metal coordination effects in dynamic reaction networks. Novel base-free nitroaldol reactivity is exploited in reaction networks with hemiacetals. A systemic response to metals is demonstrated by hemiacetal-metal coordination. In the second half of the chapter, a biomimetic dynamic imine complex is shown to produce emergent, π-π-interactions resembling a “draw-bridge”. Variation of metal charge, effective electrostatic character of substituent and ligands gives control over the system and its emergent π-π-interactions.
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| 49. |
- Kćrćdi, F., et al.
(författare)
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Fused 1,2,4-triazole heterocycles. ii : Reaction of 2-chloro-3-(1,3-dioxolan-2-yl)quinolines with 1,2,4-triazole-5-thiol
- 1995
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Ingår i: Heterocyclic Communications. - : Walter de Gruyter GmbH. - 0793-0283 .- 2191-0197. ; 1:2-3, s. 195-198
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Tidskriftsartikel (refereegranskat)abstract
- Reaction of 2-chloro-3-(1,3-dioxolan-2-yl)quinolines 1 with 1,2,4-triazole-5-thiol 2 leads to the formation of a mixture of 11-(2-hydroxyethyl)oxy-11H-[1,2,4]triazolo[5',1':2,3][1,3]thiazino[6,5-b]quinolines 3 and 11-(2-hydroxyethyl)oxy-11/-/-[1,2,4]triazolo[3',4':2,3][1,3]thiazino[6,5-£>]quinolines 4. The structures of the separated regioisomers were determined by homonuclear NOE difference spectroscopy and the results were further confirmed by desulfurisation.
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| 50. |
- Kolehmainen, Jari, et al.
(författare)
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Quadruple Helix, Innovation and the Knowledge-Based Development : Lessons from Remote, Rural and Less-Favoured Regions
- 2016
-
Ingår i: Journal of the Knowledge Economy. - New York : Springer Science+Business Media B.V.. - 1868-7865 .- 1868-7873. ; 7:1, s. 23-42
-
Tidskriftsartikel (refereegranskat)abstract
- This paper addresses the dynamics of knowledge-based development of remote, rural and less-favoured regions. Many of the regional strategies and policies aimed at developing innovation emanate from policymakers in centrally located urban conurbations and are assumed to be universally applicable. An example is the classical “triple helix” model and its successors for economic development based around the idea of universities, business and public sector organisations all coming together to foster innovation and economic prosperity. In many remote, rural and less-favoured localities, there may not be a university or other knowledge-intensive institution present which makes a difference from the point of view of local development agendas. In many regions, also the business community may be scattered and insufficiently developed in terms of innovation. And furthermore, this kind of region may also have a weak public sector to enhance innovativeness. In such regions, social and community groups may often play the dominant entrepreneurial role. The community may also play a significant role in remote, rural and less-favoured regions where the basic elements of “triple helix” model are present. In this respect the concept of a “quadruple helix” is highly beneficial. This is the case, because innovation processes are becoming increasingly open to different stakeholders. In this paper, four illustrative cases of knowledge-based development processes and policies in remote, rural and less-favoured regions are analysed by using a “double-coin model of knowledge-based regional development” which places the quadruple helix model at the very heart of knowledge-based regional development.
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