Switching between Proton Vacancy and Excess Proton Transfer Pathways in the Reaction between 7-Hydroxyquinoline and Formate

Bifunctional or amphoteric photoacids simultaneously present donor (acidic) and acceptor (basic) properties making them useful tools to analyze proton transfer reactions. In protic solvents, the proton exchange between the acid and the base is controlled by the acidity or basicity strength and typically occurs on two different pathways known as protolysis and hydrolysis. We report here how the addition of a formate base will alter the relative importance of the possible reaction pathways of the bifunctional photoacid 7-hydroxyquinoline (7HQ), which has been recently understood to predominantly involve a hydroxide/methoxide transport mechanism between the basic proton-accepting quinoline nitrogen site toward the proton-donating OH group with a time constant of 360 ps in deuterated methanol (CD3OD). We follow the reaction dynamics by probing the IR-active marker modes of the different charged forms of photoexcited 7HQ, and of formic acid (HCOOD) in CD3OD solution. A comparison of the transient IR spectra as a function of formate concentration, and classical molecular dynamics simulations enables us to identify distinct contributions of “tight” (meaning “contact”) and “loose” (i.e., “solvent-separated”) 7HQ–formate reaction pairs in our data. Our results suggest that depending on the orientation of the OH group with respect to the quinoline aromatic ring system, the presence of the formate molecule in a proton relay pathway facilitates a net proton transfer from the proton-donating OH group of 7HQ-N* via the methanol/formate bridge toward the quinoline N site

Energetics of Technical Integration of 2‐Propanol Fuel Cells: Thermodynamic and Current and Future Technical Feasibility

2-Propanol/acetone is a promising liquid organic hydrogen carrier system for fuelcell reactions. Herein, six different concepts for a 2-propanol/acetone fuel cellsystem are evaluated in MATLAB simulation with respect to their thermodynamicintegration and technical feasibility. Four of the concepts use a direct 2-propanolfuel cell while the other two first release molecular hydrogen from 2-propanol andsubsequently use a hydrogen fuel cell. The presented liquid phase 2-propanol fuelcell concept is thermodynamically feasible but cannot be realized technicallyusing commercial Nafion membranes, due to membrane dissolution by the2-propanol/acetone/water fuel mixture. Gaseous 2-propanol fuel cells imply a highheating requirement for the evaporation of the fuel. A direct high-temperature fuelcell using 2-propanol is thermodynamically feasible because there is less water inthe overall system but is not technically feasible because of the esterification ofphosphoric acid. A very interesting option is the conversion of gaseous 2-propanolto pressurized hydrogen in an electrochemical pumping step followed by ahydrogen fuel cell, because here the waste heat of a sufficiently hot hydrogen fuelcell can drive the 2-propanol evaporation

Zwischen Schattendasein, Governance und Entrepreneurship - Eine empirische Bestandsaufnahme zum Professionalisierungsgrad des IT-Managements in deutschen Krankenhäusern

Bei der Umsetzung der digitalen Transformation bewegt sich das ITManagement in Krankenhäusern in einem Spannungsfeld aus historischkulturellen Vorbedingungen und den besonderen Herausforderungen wissensintensiver Expertenorganisation. Um zu untersuchen, wie professionell das ITManagement vor diesem Hintergrund ist, wurde in der vorliegenden Studie der Professionalisierungsgrad des IT-Managements als Beschreibungsgröße vorgeschlagen. Darüber hinaus wurden Ausprägungen der IT-Governance und des IT-Entrepreneurships als mögliche Determinanten des Professionalisierungsgrades konzeptionalisiert. Ein entsprechend aufgestelltes, hypothesengeleitetes Untersuchungsmodell wurde anhand der Daten von 164 CIOs deutscher Krankenhäuser überprüft. Die Ergebnisse der Studie deuten auf Professionalisierungspotenziale des IT-Managements im strategischen und evaluierenden Bereich hin. Etablierte Kommunikationskanäle zwischen CIO und Krankenhausleitung sowie eine ausgewiesene IT-Budgetverantwortungen wirkten sich positiv auf den Professionalisierungsgrad aus. Zudem Das agierte das ITManagement umso professioneller, je stärker der IT-Entrepreneurship auf organisatorischer und individueller Ebene ausgeprägt war. Die Ergebnisse können den theoretischen Erkenntnisstand über die Wirkungsweise von IT-Governance und IT-Entrepreneurship erweitern und auf ähnliche, wissensintensive Expertenorganisationen übertragen werden

Die Stellung des Deutschtums in Posen und Westpreussen : mit einer Sprachenkarte der deutschen Ostmarken

von Moritz WeissIn Fraktu

Exploring Free Energy Profiles of Enantioselective Organocatalytic Aldol Reactions under Full Solvent Influence

We present a computational study on the enantioselectivity of organocatalytic proline-catalyzed aldol reactions between aldehydes in dimethylformamide (DMF). To explore the free energy surface of the reaction, we apply two-dimensional metadynamics on top of ab initio molecular dynamics (AIMD) simulations with explicit solvent description on the DFT level of theory. We avoid unwanted side reactions by utilizing our newly developed hybrid AIMD (HyAIMD) simulation scheme, which adds a simple force field to the AIMD simulation to prevent unwanted bond breaking and formation. Our condensed phase simulation results are able to nicely reproduce the experimental findings, including the main stereoisomer that is formed, and give a correct qualitative prediction of the change in syn:anti product ratio with different substituents. Furthermore, we give a microscopic explanation for the selectivity. We show that both the explicit description of the solvent and the inclusion of entropic effects are vital to a good outcome—metadynamics simulations in vacuum and static nudged elastic band (NEB) calculations yield significantly worse predictions when compared to the experiment. The approach described here can be applied to a plethora of other enantioselective or organocatalytic reactions, enabling us to tune the catalyst or determine the solvent with the highest stereoselectivity

Diffusion Dynamics of Radiology IT : Systems in German Hospitals : A Bayesian Bass Model

Radiology has a reputation for having a high affinity to innovation – particularly with regard to information technologies. Designed for supporting the peculiarities of radiological diagnostic workflows, Radiology Information Systems (RIS) and Picture Archiving and Communication Systems (PACS) developed into widely used information systems in hospitals and form the basis for advancing the field towards automated image diagnostics. RIS and PACS can thus serve as meaningful indicators of how quickly IT innovations diffuse in secondary care settings – an issue that requires increased attention in research and health policy in the light of increasingly fast innovation cycles. We therefore conducted a retrospective longitudinal observational study to research the diffusion dynamics of RIS and PACS in German hospitals between 2005 and 2017. Based upon data points collected within the “IT Report Healthcare” and building on Rogers’ Diffusion of Innovation (DOI) theory, we applied a novel methodological technique by fitting Bayesian Bass Diffusion Models on past adoption rates. The Bass models showed acceptable goodness of fit to the data and the results indicated similar growth rates of RIS and PACS implementations and suggest that market saturation is almost reached. Adoption rates of PACS showed a slightly higher coefficient of imitation (q = 0.25) compared to RIS (q = 0.11). However, the diffusion process expands over approximately two decades for both systems which points at the need for further research into how innovation diffusion can be accelerated effectively. Furthermore, the Bayesian approach to Bass modelling showed to have several advantages over the classical frequentists approaches and should encourage adoption and diffusion research to adapt similar techniques

Exploring Innovation Capabilities of Hospital CIOs : An Empirical Assessment

Hospital CIOs play a central role in the adoption of innovative health IT. Until now, it remained unclear which particular conditions constitute their capability to innovate in terms of intrapersonal as well as organisational factors. An inventory of 20 items was developed to capture these conditions and examined by analysing data obtained from 164 German hospital CIOs. Principal component analysis resulted in three internally consistent components that constitute large portions of the CIOs innovation capability: organisational innovation culture, entrepreneurship personality and openness towards users. Results were used to build composite indicators that allow further evaluations

The Role of AlphαSynuclein in Mouse Models of Acute, Inflammatory and Neuropathic Pain

(1) AlphαSynuclein (αSyn) is a synaptic protein which is expressed in the nervous system and has been linked to neurodegenerative diseases, in particular Parkinson’s disease (PD). Symptoms of PD are mainly due to overexpression and aggregation of αSyn and include pain. However, the interconnection of αSyn and pain has not been clarified so far. (2) We investigated the potential effects of a αSyn knock-out on the nociceptive behaviour in mouse models of acute, inflammatory and neuropathic pain. Furthermore, we assessed the impact of αSyn deletion on pain-related cellular and molecular mechanisms in the spinal cord in these models. (3) Our results showed a reduction of acute cold nociception in αSyn knock-out mice while responses to acute heat and mechanical noxious stimulation were similar in wild type and knock-out mice. Inflammatory nociception was not affected by αSyn knock-out which is also mirrored by unaltered inflammatory gene expression. In contrast, in the SNI model of neuropathic pain, αSyn knock-out mice showed decreased mechanical allodynia as compared to wild type mice. This effect was associated with reduced proinflammatory mechanisms and suppressed activation of MAP kinase signalling in the spinal cord while endogenous antinociceptive mechanisms are not inhibited. (4) Our data indicate that αSyn plays a role in neuropathy and its inhibition might be useful to ameliorate pain symptoms after nerve injury