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1.
J Am Chem Soc ; 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38838087

ABSTRACT

For the excitation to a repulsive state of a diatomic molecule, one expects a single broad peak in the photodissociation spectrum. For Zn2+, however, two peaks for the spin- and symmetry-allowed A2Σg+ ← X2Σu+ transition are observed. A detailed quantum-chemical analysis reveals pronounced multiconfigurational character of the A2Σg+ state. The σg(4s)2σg(4p) configuration with bond order 1.5 dominates at short distances, while the repulsive σg(4s)σu*(4s)2 configuration with bond order -0.5 wins over with increasing bond length. The two excited-state configurations contribute with opposite signs to the transition dipole moment, which reaches zero near the equilibrium distance. This local minimum of the oscillator strength is responsible for the pronounced dip in the photodissociation spectrum, which is thus the spectroscopic signature of the multiconfigurational character of the A2Σg+ state.

2.
J Chem Phys ; 160(13)2024 Apr 07.
Article in English | MEDLINE | ID: mdl-38557850

ABSTRACT

Molecular cluster ions, which are stored in an electromagnetic trap under ultra-high vacuum conditions, undergo blackbody infrared radiative dissociation (BIRD). This process can be simulated with master equation modeling (MEM), predicting temperature-dependent dissociation rate constants, which are very sensitive to the dissociation energy. We have recently introduced a multiple-well approach for master equation modeling, where several low-lying isomers are taken into account. Here, we experimentally measure the BIRD of CO4●-(H2O)1,2 and model the results with a slightly modified multiple-well MEM. In the experiment, we exclusively observe loss of water from CO4●-(H2O), while the BIRD of CO4●-(H2O)2 leads predominantly to loss of carbon dioxide, with water loss occurring to a lesser extent. The MEM of two competing reactions requires empirical scaling factors for infrared intensities and the sum of states of the loose transition states employed in the calculation of unimolecular rate constants so that the simulated branching ratio matches the experiment. The experimentally derived binding energies are ΔH0(CO4●--H2O) = 45 ± 3 kJ/mol, ΔH0(CO4●-(H2O)-H2O) = 41 ± 3 kJ/mol, and ΔH0(CO2-O2●-(H2O)2) = 37 ± 3 kJ/mol. Quantum chemical calculations on the CCSD(T)/aug-cc-pVTZ//CCSD/aug-cc-pVDZ level, corrected for the basis set superposition error, yield binding energies that are 2-5 kJ/mol higher than experiment, within error limits of both experiment and theory. The relative activation energies for the two competing loss channels are as well fully consistent with theory.

3.
Phys Chem Chem Phys ; 26(14): 10904-10918, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38525830

ABSTRACT

As one of the main components of sea salt aerosols, sodium chloride is involved in numerous atmospheric processes. Gas-phase clusters are ideal models to study fundamental physical and chemical properties of sodium chloride, which are significantly affected by the cluster size. Of particular interest are magic cluster sizes, which exhibit high intensities in mass spectra. In order to understand the origin of these magic cluster sizes, quantum chemical calculations at the CCSD(T)//DFT level are performed, yielding structures and binding energies of neutral (NaCl)x, anionic (NaCl)xCl- and cationic (NaCl)xNa+ clusters up to x = 8. Our calculations show that the clusters can easily isomerize, enabling dissociation into the lowest-energy isomers of the fragments. Energetics can explain the special stability of (NaCl)4Cl-, but (NaCl)4Na+ actually offers low-lying dissociation channels, despite being a magic cluster size. Collision-induced dissociation experiments reveal that the loss of neutral clusters (NaCl)x, x = 2, 4, is in most cases more favorable than the loss of NaCl or the atomic ion, i.e. sodium chloride clusters actually fragment via the cleavage of the entire cluster, not by evaporating small cluster building blocks. This is rationalized by the calculated high stability of even-numbered neutral clusters (NaCl)x, especially x = 2, 4. Analysis of the density of states and rate constants calculated with a modified Rice-Ramsperger-Kassel-Marcus (RRKM) equation called AWATAR - considering all energetically accessible isomers of reactants and fragments - shows that entropic effects are responsible for the magic cluster character of (NaCl)4Na+. In particular, low-lying vibrational modes provide a high density of states of the near-planar cluster. Together with the small contribution of an atomic ion to the sum of states in a loose transition state for dissociation, this leads to a very small unimolecular rate constant for dissociation into (NaCl)4 and Na+, which is the lowest energy fragmentation pathway. Thus, entropic effects may override energetics for certain magic cluster sizes.

4.
Clin Res Cardiol ; 2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38466346

ABSTRACT

BACKGROUND: Previous reports suggest septal hypertrophy with an interventricular septum depth (IVSD) ≥ 14 mm may adversely affect outcomes after transcatheter aortic valve implantation (TAVI) due to suboptimal valve placement, valve migration, or residual increased LVOT pressure gradients. AIMS: This analysis investigates the impact of interventricular septal hypertrophy on acute outcomes after TAVI. METHODS: Between 2009 and 2021, 1033 consecutive patients (55.8% male, 80.5 ± 6.7 years, EuroSCORE II 6.3 ± 6.5%) with documented IVSD underwent TAVI at our center and were included for analysis. Baseline, periprocedural, and 30-day outcome parameters of patients with normal IVSD (< 14 mm; group 1) and increased IVSD (≥ 14 mm; group 2) were compared. Data were retrospectively analyzed according to updated Valve Academic Research Consortium-3 (VARC-3) definitions. Comparison of outcome parameters was adjusted for baseline differences between groups using logistic and linear regression analyses. RESULTS: Of 1033 patients, 585 and 448 patients were allocated to groups 1 and 2, respectively. There was no significant difference between groups regarding transfemoral access rate (82.6% (n = 478) vs. 86.0% (n = 381), p = 0.157). Postprocedural mean transvalvular pressure gradient was significantly increased in group 2 (group 1, 7.8 ± 4.1 mmHg, vs. group 2, 8.9 ± 4.9 mmHg, p = 0.046). Despite this finding, there was no significant difference between groups regarding the rates of VARC-3 adjudicated composite endpoint device success (90.0% (n = 522) vs. 87.6% (n = 388), p = 0.538) or technical success (92.6% (n = 542) vs. 92.6% (n = 415), p = 0.639). Moreover, the groups showed no significant differences regarding the rates of paravalvular leakage ≥ moderate (3.1% (n = 14) vs. 2.6% (n = 9), p = 0.993), postprocedural permanent pacemaker implantation (13.4% (n = 77) vs. 13.8% (n = 61), p = 0.778), or 30-day mortality (5.1% (n = 30) vs. 4.5% (n = 20), p = 0.758). CONCLUSION: Although transvalvular mean pressure gradients were significantly higher in patients with increased IVSD after TAVI, acute outcomes were comparable between groups suggesting no early impact of adverse hemodynamics due to elevated IVSD. However, how these differences in hemodynamic findings may affect mid- and long-term outcomes, especially in terms of valve durability, needs to be evaluated in further investigations.

5.
J Phys Chem A ; 128(7): 1306-1312, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38347749

ABSTRACT

The fullerene ion C60+ is the only carrier of diffuse interstellar bands (DIBs) identified so far. Transition-metal compounds feature electronic transitions in the visible and near-infrared regions, making them potential DIB carriers. Since iron is the most abundant transition metal in the cosmos, we here test this idea with Fe+(H2O). Laboratory spectra were obtained by photodissociation spectroscopy at 80 K. Spectra were modeled with the reflection principle. A high-resolution spectrum of the DIB standard star HD 183143 served as an observational reference. Two broad bands were observed from 4120 to 6800 Å. The 4120-4800 Å band has sharp features emerging from the background, which have the width of DIBs but do not match the band positions of the reference spectrum. Calculations show that the spectrum arises from a d-d transition at the iron center. While no match was found for Fe+(H2O) with known DIBs, the observation of structured bands with line widths typical for DIBs shows that small molecules or molecular ions containing iron are promising candidates for DIB carriers.

6.
Clin Res Cardiol ; 113(1): 86-93, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37391628

ABSTRACT

AIM: Transcatheter aortic valve implantation (TAVI) is a mainstay in the management of severe aortic valve stenosis in elderly patients, but there is uncertainty on their long-term effectiveness. We aimed to assess the long-term outcome of patients undergoing TAVI with the Portico valve. METHODS: We retrospectively collected the data on patients in whom TAVI with Portico was attempted from 7 high-volume centres. Only patients theoretically eligible for 3 or more years of follow-up were included. Clinical outcomes, including death, stroke, myocardial infarction, reintervention for valve degeneration and hemodynamic valve performance were systematically assessed. RESULTS: A total of 803 patients were included, with 504 (62.8%) women, mean age of 82 years, median EuroSCORE II of 3.1%, and 386 (48.1%) subjects at low/moderate risk. The median follow-up was 3.0 years (3.0; 4.0). The composite of death, stroke, myocardial infarction, and reintervention for valve degeneration occurred in 37.5% (95% confidence interval: 34.1-40.9%), with all-cause death in 35.1% (31.8-38.4%), stroke in 3.4% (1.3-3.4%), myocardial infarction in 1.0% (0.3-1.5%), and reintervention for valve degeneration in 1.1% (0.6-2.1%). The mean aortic valve gradient at follow-up was 8.1 ± 4.6 mmHg, and at least moderate aortic regurgitation was present in 9.1% (6.7-12.3%). Independent predictors of major adverse events or death were: peripheral artery disease, chronic obstructive pulmonary disease, estimated glomerular filtration rate, atrial fibrillation, prior pacemaker implantation, EuroSCORE II, and reduced left ventricular ejection fraction (all p < 0.05). CONCLUSIONS: Portico use is associated with favorable long-term clinical outcomes. Clinical outcomes were largely impacted by baseline risk factors and surgical risk.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Myocardial Infarction , Stroke , Transcatheter Aortic Valve Replacement , Humans , Female , Aged , Aged, 80 and over , Male , Transcatheter Aortic Valve Replacement/adverse effects , Aortic Valve/surgery , Retrospective Studies , Stroke Volume , Treatment Outcome , Ventricular Function, Left , Aortic Valve Stenosis/surgery , Stroke/etiology
7.
Eur J Cardiothorac Surg ; 65(1)2024 Jan 02.
Article in English | MEDLINE | ID: mdl-38152923

ABSTRACT

OBJECTIVES: Relevant paravalvular leakage (PVL) due to prosthesis dislodgement is a rare but potentially severe complication after transcatheter mitral valve implantation (TMVI). Due to the epicardial anchoring mechanism of the Tendyne® TMVI system, repositioning of the valve stent may be possible by retensioning of the tether. This multicentre study aimed to investigate the procedural and short-term safety as well as efficacy of retensioning manoeuvres. METHODS: From 2017 to 2021, N = 18 patients who underwent secondary tether retensioning were identified. Baseline, procedural and follow-up data were available from N = 11 patients and analysed according to the Mitral Valve Research Consortium definitions. Continuous variables are shown as median with interquartile range. RESULTS: All patients [age 75 years (73.5, 85.0), 64% male (N = 7), EuroSCORE II 6.2% (5.8, 11.6)] presented with post-procedural PVL [63.6% (N = 7) with PVL ≥3+]. Of these, 54% (N = 6) showed signs of haemolysis. The majority were severely symptomatic [New York Heart Association ≥III (91%, N = 10)]. Procedural outcomes revealed no acute complications and no mortality. At discharge, PVL was completely eliminated in 91% (N = 10) of patients with 1 case of remaining moderate PVL. At 30 days, Mitral Valve Research Consortium device success was achieved in 82% (N = 9) of patients. Two patients required open surgical mitral valve replacement due to persistent and recurrent PVL. In 89% (N = 8) of patients with successful retensioning procedure, New York Heart Association class was I/II. There was no 30-day mortality. CONCLUSIONS: This multicentre study demonstrates technical feasibility, procedural safety and acute efficacy of retensioning procedures in the majority of patients. The potential to retension the tether in transapical TMVI may provide additional management advantages in populations at high surgical risk.


Subject(s)
Heart Valve Prosthesis Implantation , Heart Valve Prosthesis , Mitral Valve Insufficiency , Humans , Male , Aged , Female , Mitral Valve/surgery , Heart Valve Prosthesis Implantation/methods , Mitral Valve Insufficiency/surgery , Treatment Outcome , New York , Cardiac Catheterization/methods
8.
Environ Sci Atmos ; 3(10): 1396-1406, 2023 Oct 12.
Article in English | MEDLINE | ID: mdl-38013930

ABSTRACT

Glyoxylic acid is formed in the troposphere by oxidation of organic molecules. In sea salt aerosols, it is expected to be present as glyoxylate, integrated into the salt environment and strongly interacting with water molecules. In water, glyoxylate is in equilibrium with its gem-diol form. To understand the influence of water and salt on the photophysics and photochemistry of glyoxylate, we generate small model clusters containing glyoxylate by electrospray ionization and study them by Fourier-Transform Ion Cyclotron Resonance (FT-ICR) mass spectrometry. We used infrared multiple photon dissociation spectroscopy and UV/vis photodissociation spectroscopy for structural characterization as well as quantum chemical calculations to model the spectra and dissociation patterns. Resonant absorption of infrared radiation leads to water evaporation, which indicates that water and glyoxylate are separate molecular entities in a significant fraction of the clusters, in line with the observed absorption of UV light in the actinic region. Hydration of glyoxylate leads to a change of the dihedral angle in the CHOCOO-·H2O complex, causing a slight redshift of the S1 ← S0 transition. However, the barriers for internal rotation are below 5 kJ mol-1, which explains the broad S1 ← S0 absorption extending from about 320 to 380 nm. Most importantly, hydration hinders dissociation in the S1 state, thus enhancing the quantum yield of fluorescence combined with water evaporation. No C-C bond photolysis is observed, but due to the limited signal-to-noise ratio, it cannot be ruled out. The quantum yield, however, will be relatively low. Fluorescence dominates the photophysics of glyoxylate embedded in the dry salt cluster, but the quantum yield shifts towards internal conversion upon addition of one or two water molecules.

9.
Rev Sci Instrum ; 94(6)2023 Jun 01.
Article in English | MEDLINE | ID: mdl-37862508

ABSTRACT

A versatile multifunctional laboratory-based near ambient pressure x-ray photoelectron spectroscopy (XPS) instrument is presented. The entire device is highly customized regarding geometry, exchangeable manipulators and sample stages for liquid- and solid-state electrochemistry, cryochemistry, and heterogeneous catalysis. It therefore delivers novel and unique access to a variety of experimental approaches toward a broad choice of functional materials and their specific surface processes. The high-temperature (electro)catalysis manipulator is designed for probing solid state/gas phase interactions for heterogeneous catalysts including solid electrolyzer/fuel cell electrocatalysts at pressures up to 15 mbar and temperatures from room temperature to 1000 °C. The liquid electrochemistry manipulator is specifically designed for in situ spectroscopic investigations of polarized solid/liquid interfaces using aqueous electrolytes and the third one for experiments for ice and ice-like materials at cryogenic temperatures to approximately -190 °C. The flexible and modular combination of these setups provides the opportunity to address a broad spectrum of in situ and operando XPS experiments on a laboratory-based system, circumventing the limited accessibility of experiments at synchrotron facilities.

10.
Z Evid Fortbild Qual Gesundhwes ; 182-183: 125-129, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37806814

ABSTRACT

INTRODUCTION: In the past decade, a legal framework was created in Germany that promotes intense collaboration at the interface between primary and secondary care. This overview article distinguishes between the effects of two complementary programs aimed at improving ambulatory care in Baden-Wuerttemberg: (1) general practitioner-centered care (GPCC), which strengthens the role of general practitioners, and (2) collaborative cardiology care (CCC), which coordinates primary and cardiology care. METHODS: The overview article presents two already published studies that assess the impact of the programs on hospitalizations in patients with chronic heart failure (CHF) based on claims data from 2016. The hospitalization rate of patients enrolled in GPCC (N=75,096) and CCC (N=13,404) were compared with corresponding control groups (N=65,618 and N=8,776 respectively). RESULTS: The hospitalization rate in GPCC was lower than in the control group (risk ratio 0.97; 95% CI: 0.95-0.99, P=0.0024). GPCC patients with CHF that received specialist cardiology care as part of CCC had significantly lower hospitalization rates than those receiving standard cardiology care (risk ratio 0.92; 0.88-0.97, P=0.0014). DISCUSSION: This overwiew study shows that reforming medical care and compensation at the interface between general practice and specialist care can lead to fewer hospital admissions in patients with CHF. CONCLUSION: Overall, this article underlines the importance of collaboration between primary care physicians and specialists for patients with CHF that are receiving ambulatory care.


Subject(s)
Heart Failure , Secondary Care , Humans , Family Practice , Germany , Heart Failure/therapy , Hospitalization
11.
Int J Integr Care ; 23(2): 22, 2023.
Article in English | MEDLINE | ID: mdl-37275630

ABSTRACT

Objective: To evaluate a novel healthcare programme for the treatment of patients with hip and knee osteoarthritis in southern Germany in terms of clinical and health economic outcomes. The study is based on claims data from 2014 to 2017. Methods: We conducted a retrospective comparative cohort study of 9768 patients with hip and knee osteoarthritis, of whom 9231 were enrolled in a collaborative ambulatory orthopaedic care programme (intervention group), and 537 patients received usual orthopaedic care (control group). Key features of the programme are coordinated care, morbidity-adapted reimbursement and extended consultation times. Multivariable analysis was performed to determine effects on health utilisation outcomes. The economic analysis considered annual costs per patient from a healthcare payer perspective, stratified by healthcare service sector. Besides multivariable regression analyses, bootstrapping was used to estimate confidence intervals for predicted mean costs by group. Results: Musculoskeletal-disease-related hospitalisation was much less likely among intervention group patients than control group patients [odds ratio (OR): 0.079; 95% CI: 0.062-0.099]. The number of physiotherapy prescriptions per patient was significantly lower in the intervention group (RR: 0.814; 95% CI: 0.721-0.919), while the likelihood of participation in exercise programmes over one year was significantly higher (OR: 3.126; 95% CI: 1.604-6.094). Enrolment in the programme was associated with significantly higher ambulatory costs (€1048 vs. €925), but costs for inpatient care, including hospital stays, were significantly lower (€1003 vs. €1497 and €928 vs. €1300 respectively). Overall annual cost-savings were €195 per patient. Conclusions: Collaborative ambulatory orthopaedic care was associated with reduced hospitalisation in patients with hip and knee osteoarthritis. Health costs for programme participants were lower overall, despite higher costs for ambulatory care.

12.
J Phys Chem A ; 127(15): 3402-3411, 2023 Apr 20.
Article in English | MEDLINE | ID: mdl-37040467

ABSTRACT

Transition metals are important in various industrial applications including catalysis. Due to the current concentration of CO2 in the atmosphere, various ways for its capture and utilization are investigated. Here, we study the activation of CO2 and H2O at [NbO3]- in the gas phase using a combination of infrared multiple photon dissociation spectroscopy and density functional theory calculations. In the experiments, Fourier-transform ion cyclotron resonance mass spectrometry is combined with tunable IR laser light provided by the intracavity free-electron laser FELICE or optical parametric oscillator-based table-top laser systems. We present spectra of [NbO3]-, [NbO2(OH)2]-, [NbO2(OH)2]-(H2O) and [NbO(OH)2(CO3)]- in the 240-4000 cm-1 range. The measured spectra and observed dissociation channels together with quantum chemical calculations confirm that upon interaction with a water molecule, [NbO3]- is transformed to [NbO2(OH)2]- via a barrierless reaction. Reaction of this product with CO2 leads to [NbO(OH)2(CO3)]- with the formation of a [CO3] moiety.

13.
EuroIntervention ; 19(2): e176-e187, 2023 Jun 05.
Article in English | MEDLINE | ID: mdl-37013922

ABSTRACT

BACKGROUND: Reducing rates of permanent pacemaker implantation (PPI) after transcatheter aortic valve implantation (TAVI) is important for achieving the best procedural outcomes. The cusp overlap technique (COT) implements procedural steps including an overlap angulation of the right and left coronary cusp to mitigate this complication. AIMS: We investigated the incidence of PPI and complication rates following the COT compared to the standard three-cusp implantation technique (3CT) in an all-comers cohort. METHODS: A total of 2,209 patients underwent TAVI with the self-expanding Evolut platform from January 2016 to April 2022 at five sites. Baseline, procedural and in-hospital outcome characteristics were compared for both techniques before and after one-to-one propensity score matching. RESULTS: A total of 1,151 patients were implanted using the 3CT and 1,058 using the COT. At discharge, the rates of PPI (17.0 vs 12.3%; p=0.002) and moderate/severe paravalvular regurgitation (4.6% vs 2.4%; p=0.006) were significantly reduced with the COT compared with 3CT within the unmatched cohort. Overall procedural success and complication rates were similar; major bleeding was less common in the COT group (7.0% vs 4.6%; p=0.020). These results remained consistent after propensity score matching. In multivariable logistic regression analysis, right bundle branch block (odds ratio [OR] 7.19, 95% confidence interval [CI]: 5.18-10.0; p<0.001) and diabetes mellitus (OR 1.38, 95% CI: 1.05-1.80; p=0.021) emerged as predictors of PPI, whereas the COT (OR 0.63, 95% CI: 0.49-0.82; p<0.001) was protective. CONCLUSIONS: The introduction of the COT was associated with a significant and relevant reduction of PPI and paravalvular regurgitation rates without an increase in complication rates.


Subject(s)
Aortic Valve Stenosis , Heart Valve Prosthesis , Pacemaker, Artificial , Transcatheter Aortic Valve Replacement , Humans , Aortic Valve/surgery , Aortic Valve Stenosis/surgery , Postoperative Complications/epidemiology , Transcatheter Aortic Valve Replacement/adverse effects , Transcatheter Aortic Valve Replacement/methods , Treatment Outcome , Prosthesis Design , Risk Factors
14.
J Am Soc Mass Spectrom ; 34(3): 337-354, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36744598

ABSTRACT

The precise location of an ion or electron, whether it is internally solvated or residing on the surface of a water cluster, remains an intriguing question. Subtle differences in the hydrogen bonding network may lead to a preference for one or the other. Here we discuss spectroscopic probes of the structure of gas-phase hydrated ions in combination with quantum chemistry, as well as H/D exchange as a means of structure elucidation. With the help of nanocalorimetry, we look for thermochemical signatures of surface vs internal solvation. Examples of strongly size-dependent reactivity are reviewed which illustrate the influence of surface vs internal solvation on unimolecular rearrangements of the cluster, as well as on the rate and product distribution of ion-molecule reactions.

15.
Chemistry ; 29(26): e202203590, 2023 May 08.
Article in English | MEDLINE | ID: mdl-36729049

ABSTRACT

Molecular processes behind hydrogen evolution reactions can be quite complex. In macroscopic electrochemical cells, it is extremely difficult to elucidate and understand their mechanism. Gas phase models, consisting of a metal ion and a small number of water molecules, provide unique opportunities to understand the reaction pathways in great detail. Hydrogen evolution in clusters consisting of a singly charged metal ion and one to on the order of 50 water molecules has been studied extensively for magnesium, aluminum and vanadium. Such clusters with around 10-20 water molecules are known to eliminate atomic or molecular hydrogen upon mild activation by room temperature black-body radiation. Irradiation with ultraviolet light, by contrast, enables hydrogen evolution already with a single water molecule. Here, we analyze and compare the reaction mechanisms for hydrogen evolution on the ground state as well as excited state potential energy surfaces. Five distinct mechanisms for evolution of atomic or molecular hydrogen are identified and characterized.

16.
J Am Chem Soc ; 144(47): 21485-21493, 2022 11 30.
Article in English | MEDLINE | ID: mdl-36383735

ABSTRACT

Blackbody infrared radiative dissociation (BIRD) in a collision-free environment is a powerful method for the experimental determination of bond dissociation energies. In this work, we investigate temperature-dependent BIRD of CO3·-(H2O)1,2 at 250-330 K to determine water binding energies and assess the influence of multiple isomers on the dissociation kinetics. The ions are trapped in a Fourier-transform ion cyclotron resonance mass spectrometer, mass selected, and their BIRD kinetics are recorded at varying temperatures. Experimental BIRD rates as a function of temperature are fitted with rates obtained from master equation modeling (MEM), using the water binding energy as a fit parameter. MEM accounts for the absorption and emission of photons from black-body radiation, described with harmonic frequencies and infrared intensities from quantum chemical calculations. The dissociation rates as a function of internal energy are calculated by Rice-Ramsperger-Kassel-Marcus theory. Both single-well and multiple-well MEM approaches are used. Dissociation energies derived in this way from the experimental data are 56 ± 6 and 45 ± 3 kJ/mol for the first and second water molecules, respectively. They agree within error limits with the ones predicted by ab initio calculations done at the CCSD(T)/aug-cc-pVQZ//CCSD/aug-cc-pVDZ level of theory. We show that the multiple-well MEM approach described here yields superior results in systems with several low-lying minima, which is the typical situation for hydrated ions.


Subject(s)
Infrared Rays , Water , Anions , Kinetics , Water/chemistry , Carbonates
17.
BMC Musculoskelet Disord ; 23(1): 740, 2022 Aug 03.
Article in English | MEDLINE | ID: mdl-35922853

ABSTRACT

BACKGROUND: In 2014, the novel orthopedic care program was established by the AOK health insurance fund in southern Germany to improve ambulatory care for patients with musculoskeletal disorders. The program offers extended consultation times, structured collaboration between general practitioners and specialists, as well as a renewed focus on guideline-recommended therapies and patient empowerment. The aim of this study was to assess the impact of the program on health service utilization in patients with hip and knee osteoarthritis (OA). METHODS: This retrospective cohort study, which is based on claims data, evaluated health service utilization in patients with hip and knee OA from 2014 to 2017. The intervention group comprised OA patients enrolled in collaborative ambulatory orthopedic care, and the control group received usual care. The outcomes were participation in exercise interventions, prescription of physical therapy, OA-related hospitalization, and endoprosthetic surgery rates. Generalized linear regression models were used to analyze the effect of the intervention. RESULTS: Claims data for 24,170 patients were analyzed. Data for the 23,042 patients in the intervention group were compared with data for the 1,128 patients in the control group. Participation in exercise interventions (Odds Ratio (OR): 1.781; 95% Confidence Interval (CI): 1.230-2.577; p = 0.0022), and overall prescriptions of physical therapy (Rate Ratio (RR): 1.126; 95% CI: 1.025-1.236; p = 0.0128) were significantly higher in the intervention group. The intervention group had a significantly lower risk of OA -related hospitalization (OR: 0.375; 95% CI: 0.290-0.485; p < 0.0001). Endoprosthetic surgery of the knee was performed in 53.8% of hospitalized patients in the intervention group vs. 57.5% in the control group; 27.7% of hospitalized patients underwent endoprosthetic surgery of the hip in the intervention group versus 37.0% in the control group. CONCLUSIONS: In patients with hip and knee OA, collaborative ambulatory orthopedic care is associated with a lower risk of OA-related hospitalization, higher participation in exercise interventions, and more frequently prescribed physical therapy.


Subject(s)
Osteoarthritis, Hip , Osteoarthritis, Knee , Ambulatory Care , Cohort Studies , Humans , Osteoarthritis, Hip/rehabilitation , Osteoarthritis, Hip/surgery , Osteoarthritis, Knee/rehabilitation , Osteoarthritis, Knee/surgery , Retrospective Studies
18.
BMJ Open ; 12(8): e062657, 2022 08 08.
Article in English | MEDLINE | ID: mdl-35940832

ABSTRACT

OBJECTIVES: To compare opioid prescription rates between patients enrolled in coordinated ambulatory care and patients receiving usual care. DESIGN: In this retrospective cohort study, we analysed claims data for insured patients with non-specific/specific back pain or osteoarthritis of hip or knee from 2014 to 2017. SETTING: The study was based on administrative data provided by the statutory health insurance fund 'Allgemeine Ortskrankenkasse', in the state of Baden-Wurttemberg, Germany. PARTICIPANTS: The intervention group consisted of patients enrolled in a coordinated ambulatory healthcare model; the control group included patients receiving usual care. Outcomes were overall strong and weak opioid prescriptions. Generalised linear regression models were used to analyse the effect of the intervention. RESULTS: Overall, 46 001 (non-specific 18 787/specific 27 214) patients with back pain and 19 366 patients with osteoarthritis belonged to the intervention group, and 7038 (2803/4235) and 963 patients to the control group, respectively. No significant difference in opioid prescriptions existed between the groups. However, the chance of being prescribed strong opioids was significantly lower in the intervention group (non-specific back pain: Odds Ratio (OR) 0.735, 95% Confidential Interval (CI) 0.563 to 0.960; specific back pain: OR 0.702, 95% CI 0.577 to 0.852; osteoarthritis: OR 0.644, 95% CI 0.464 to 0.892). The chance of being prescribed weak opioids was significantly higher in patients with specific back pain (OR 1.243, 95% CI 1.032 to 1.497) and osteoarthritis (OR 1.493, 95% CI 1.037 to 2.149) in the intervention group. CONCLUSION: Coordinated ambulatory healthcare appears to be associated with a lower prescription rate for strong opioids in patients with chronic musculoskeletal disorders. TRIAL REGISTRATION NUMBER: German Clinical Trials Register (DRKS00017548).


Subject(s)
Analgesics, Opioid , Osteoarthritis , Analgesics, Opioid/therapeutic use , Back Pain/drug therapy , Delivery of Health Care , Humans , Osteoarthritis/drug therapy , Prescriptions , Retrospective Studies
19.
J Patient Saf ; 18(5): 444-448, 2022 08 01.
Article in English | MEDLINE | ID: mdl-35948293

ABSTRACT

OBJECTIVE: The aim of this study was to analyze the strength of safety measures described in incident reports in outpatient care. METHODS: An incident reporting project in German outpatient care included 184 medical practices with differing fields of specialization. The practices were invited to submit anonymous incident reports to the project team 3 times for 17 months. Using a 14-item coding scheme based on international recommendations, we deductively coded the incident reports and safety measures. Safety measures were classified as "strong" (likely to be effective and sustainable), "intermediate" (possibly effective and sustainable), or "weak" (less likely to be effective and sustainable). RESULTS: The practices submitted 245 incident reports. In 160 of them, 243 preventive measures were described, or an average of 1.5 per report. The number of documented measures varied from 1 in 67% to 4 in 5% of them. Four preventive measures (2%) were classified as strong, 37 (15%) as intermediate, and 202 (83%) as weak. The most frequently mentioned measures were "new procedure/policy" (n = 121) and "information/notification/warning" (n = 45). CONCLUSIONS: The study provides examples of critical incidents in medical practices and for the first time examines the strength of ensuing measures introduced in outpatient care. Overall, the proportion of weak measures is (too) high, indicating that practices need more support in identifying strong measures.


Subject(s)
Medical Errors , Patient Safety , Humans , Medical Errors/prevention & control , Risk Management
20.
Phys Chem Chem Phys ; 24(27): 16576-16585, 2022 Jul 13.
Article in English | MEDLINE | ID: mdl-35775378

ABSTRACT

Molybdenum sulfides and molybdenum oxysulfides are considered a promising and cheap alternative to platinum as a catalyst for the hydrogen evolution reaction (HER). To better understand possible rearrangements during catalyst activation, we perform collision induced dissociation experiments in the gas phase with eight different molybdenum oxysulfides, namely [Mo2O2S6]2-, [Mo2O2S6]-, [Mo2O2S5]2-, [Mo2O2S5]-, [Mo2O2S4]-, [HMo2O2S6]-, [HMo2O2S5]- and [HMo2O2S4]-, on a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer. We identify fragmentation channels of the molybdenum oxysulfides and their interconnections. Together with quantum chemical calculations, the results show that [Mo2O2S4]- is a particularly stable species against further dissociation, which is reached from all starting species with relatively low collision energies. Most interestingly, H atom loss is the only fragmentation channel observed for [HMo2O2S4]- at low collision energies, which relates to potential HER activity, since two such H atom binding sites on a surface may act together to release H2. The calculations reveal that multiple isomers are often very close in energy, especially for the hydrogenated species, i.e., atomic hydrogen can bind at various sites of the clusters. S2 groups play a decisive role in hydrogen adsorption. These are further features with potential relevance for HER catalysis.

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