An estimate of the need for continuous glucose monitoring in type 2 diabetes with intensive insulin treatment in secondary healthcare.

AIM: To estimate the proportion of persons with type 2 diabetes (T2DM) receiving intensive insulin treatment in the secondary healthcare who could be candidates for continuous glucose monitoring (CGM), based on different HbA1c criteria. For comparison, the results are also presented as proportion of persons with type 1 diabetes (T1DM) in the same region. PATIENTS AND METHODS: In the Central Denmark Region, we identified all persons with T1DM (n = 6179) and T2DM (n = 4315) who had a minimum of one contact to a diabetes outpatient clinic from September 2021 to September 2022. Insulin regimen and HbA1c measured after a minimum of 2 months with a stable insulin regimen were retrieved from the healthcare administrative electronic platform used in the region. RESULTS: The numbers of persons with T1DM and T2DM with HbA1c meeting the criteria were 5145 and 3090, respectively. The fraction of T2DM with basal-bolus insulin was 35.3%, and the fraction with basal-bolus insulin and HbA1c >53 (7%) mmol/mol or >58 (7.5%) mmol/mol was 20.5% and 16.6%, respectively. These proportions correspond to 19.4%, 14.4% and 11.7% of the persons with T1DM in the same geographical area. CONCLUSION: The proportion of persons with T2DM in secondary healthcare undergoing intensive insulin treatment who could be candidates for CGM corresponded to only a minor fraction of persons with T1DM in the same region, irrespective of any HbA1c criteria applied.

Delayed photodissociation of the tin cluster Sn22.

Millisecond-delayed photodissociation of gas-phase Sn22- clusters stored in a Penning trap is investigated as a function of excitation energy. Sn15- is the only significant charged fragment, indicative of the break-off of neutral heptamers. Fits of the time-resolved fragmentation require a distribution of decay constants, caused by the finite width of the internal energy distribution of the cluster ensemble prior to photoexcitation. A lower limit for the dissociation energy for the loss of Sn7 is determined to be 2.1(1) eV, a factor of two above literature quantum chemical calculations.

Dehydrogenation of diborane on small Nbn+ clusters.

The reactivity of Nbn+ (1 ≤ n ≤ 21) clusters with B2H6 is studied by using a self-developed multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). The Nbn+ clusters were generated by a magnetron sputtering source and reacted with the B2H6 gas under fully thermalized conditions in the downstream flow tube where the reaction time was accurately controlled and adjustable. The complete and partial dehydrogenation products NbnB1-4+ and NbnB1-4H1,2,4+ were detected, indicative of the removal of H2 and likely BHx moieties. Interestingly, these NbnB1-4+ and NbnB1-4H1,2,4+ products are limited to 3 ≤ n ≤ 6, suggesting that the small Nbn+ clusters are relatively more reactive than the larger Nbn>6+ clusters under the same conditions. By varying the B2H6 gas concentrations and the reactant doses introduced into the flow tube, and by changing the reaction time, we performed a detailed analysis of the reaction dynamics in combination with the DFT-calculated thermodynamics. It is demonstrated that the lack of cooperative active sites on the Nb1+ cations accounts for the weakened dehydrogenation efficiency. Nb2+ forms partial dehydrogenation products at a faster rate. In contrast, the Nbn>6+ clusters are subject to more flexible vibrational relaxation which disperse the energy gain of B2H6-adsorption and thus are unable to overcome the energy barriers for subsequent hydrogen atom transfer and H2 release.

One size does not fit all: universal cuff overestimates oscillometric blood pressure in persons with large arm circumference.

OBJECTIVE: Some brachial cuffs for oscillometric blood pressure (BP) measurement are claimed to cover a wide range of upper-arm circumferences; however, their validation is rarely conducted. Our aim was to compare oscillometric BP measurements obtained with a universal cuff with those obtained with an appropriately sized cuff. METHODS: We utilised the Microlife B6 Connect monitor, conducting oscillometric BP measurements in a random sequence with both a universal cuff (recommended for arm circumferences from 22 to 42 cm) and an appropriately sized cuff (medium for circumference 22-32 cm and large for 32-42 cm). We included 91 individuals with an arm circumference of 22-32 cm and 64 individuals with an arm circumference of 32-42 cm. RESULTS: For arm circumferences > 32 cm, systolic and diastolic BP measured with the universal cuff was higher than that measured with the large cuff (systolic 6.4 mmHg, 95% confidence interval [CI]). 3.9-8.8, diastolic 2.4 mmHg, 95%CI, 1.2-3.7, p < 0.001 for both). Overestimation of BP with the universal cuff was statistically significant after correcting for the sequence of measurements. No statistical difference was found between the universal cuff and medium cuff for circumferences in the 22-32 cm range. The bladder size in the universal cuff matched the dimensions of the medium-sized cuff; however, the cuff was larger. CONCLUSION: Overestimation of BP measured with a universal cuff in persons with large arm circumferences is clinically important. It poses the risk of unnecessary initiation or intensification of antihypertensive medication in persons using the universal cuff.

What is the context?Clinical guidelines recommend individualisation of the size of the cuff used for blood pressure measurement according to the circumference of the upper arm.Many blood pressure monitors are sold with a single "universal" cuff claimed to cover a wide range of upper arm sizes.We compared blood pressure obtained with the Microlife B6 Connect monitor and a "universal" cuff with the results obtained with individual sized cuffs (medium size for arm circumference between 22 and 32 cm and large size for arm circumference between 32 and 42 cm).What is new?In persons with large upper arm circumference is the systolic blood pressure 6.4 mmHg higher and the diastolic blood pressure 2.4 mmHg higher with the universal cuff than with the individual-sized large cuff.What is the impact?The universal cuff overestimates blood pressure in persons with large arm circumference.

Weak Interactions Initiate C-H and C-C Bond Dissociation of Ethane on Nbn + Clusters.

The conversion of ethane into value-added chemicals under ambient conditions has attracted much attention but the mechanisms remain not fully understood. Here we report a study on the reaction of ethane with thermalized Nbn + clusters based on a multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). It is found that ethane reacts with Nbn + clusters to form both products of dehydrogenation and methane-removal (odd-carbon products). Combined with density functional theory (DFT) calculations, we studied the reaction mechanisms of the C-C bond activation and C-H bond cleavage on the Nbn + clusters. It is unveiled that hydrogen atom transfer (HAT) initiates the reaction process, giving rise to the formation of Nb-C bonds and an elongated C-C distance in the HNbn + CH2 CH3 motif. Subsequent reactions allow for C-C bond activation and a competitive HAT process which is associated with CH4 removal or H2 release, resulting in the production of the observed carbides.

The largest fullerene.

Fullerenes are lowest energy structures for gas phase all-carbon particles for a range of sizes, but graphite remains the lowest energy allotrope of bulk carbon. This implies that the lowest energy structure changes nature from fullerenes to graphite or graphene at some size and therefore, in turn, implies a limit on the size of free fullerenes as ground state structures. We calculate this largest stable single shell fullerene to be of size N = 1 × 104, using the AIREBO effective potential. Above this size fullerene onions are more stable, with an energy per atom that approaches graphite structures. Onions and graphite have very similar ground state energies, raising the intriguing possibility that fullerene onions could be the lowest free energy states of large carbon particles in some temperature range.

Fragmentation channels of non-fullerene cationic carbon clusters.

The unimolecular fragmentation channels of highly excited small cationic carbon clusters have been measured with a time-of-flight mass spectrometer after photofragmentation. The dominant channel is loss of the neutral trimer, for all CN+N = 10-27 clusters except for N = 11, 12 which decay by monomer emission, and C25+ which shows competing loss of C2 and C3. The results permit to quantify the role of the rotational entropy in the competition between monomer and trimer decays with the help of energies calculated with density functional theory.

Cascade Infrared Thermal Photon Emission.

The later stages of cooling of molecules and clusters in the interstellar medium are dominated by emission of vibrational infrared radiation. With the development of cryogenic storage it has become possible to experimentally study these processes. Recent storage ring results demonstrate that intramolecular vibrational redistribution takes place within the cooling process, and an harmonic cascade model has been used to interpret the data. Here we analyze this model and show that the energy distributions and the photon emission rates develop into near-universal functions that can be characterized with only a few parameters, irrespective of the precise vibrational spectra and oscillator strengths of the systems. We show that the photon emission rate and emitted power vary linearly with total excitation energy with a small offset. The time developments of ensemble internal energy distributions are calculated with respect to their first two moments. The excitation energy decreases exponentially with a rate constant which is the average of all k1→0 Einstein coefficients, and the time development of the variance is also calculated.

What Determines If a Ligand Undergoes Coordination or Catalytic Activation on a Metal Cluster?

We report a joint experimental and theoretical study on the reactivity of Agn+ clusters with H2S, D2O, and NH3. Complete dehydrogenation products are observed for Agn+ reacting with H2S, but no dehydrogenation products are found for D2O or NH3 under the same reaction condition. Theoretical calculations elucidate why Agn+ clusters show different reactivities with these inorganic hydrides. NH3 shows strong coordination with Agn+, but the dehydrogenation reactions are unfavorable; in contrast, the fragile H-S bonds and stable AgnS+ products facilitate the hydrogen evolution of H2S on Agn+. We fully analyzed the metal-ligand interactions of Agn+ clusters with three molecules and illustrated the reaction dynamics and charge-transfer interactions and altered the superatomic states during the formation of cluster sulfides. We expect this study to benefit the design of stable environmentally friendly desulfurization catalysts and also the understanding of the mechanism on ligand-protected metal clusters in wet chemistry.

DECAY DYNAMICS IN MOLECULAR BEAMS.

The phenomenon of power law decays in molecular beams is reviewed. The transition from a canonical to a microcanonical description of the decay is analyzed, and the appearance of the power law decay derived. Deviations from a power law often contain information on parallel competing processes. This is illustrated with examples where thermal radiation or dark unimolecular channels are the competing processes. Also corrections to the power law due to finite heat capacities and from nonideal energy distributions are derived. Finally, the consequences for the interpretation of action spectroscopy data are reviewed. © 2020 The Authors. Mass Spectrometry Reviews published by Wiley Periodicals, Inc. Mass Spec Rev.

Light-Induced Magnetization at the Nanoscale.

Triggering and switching magnetic moments is of key importance for applications ranging from spintronics to quantum information. A noninvasive ultrafast control at the nanoscale is, however, an open challenge. Here, we propose a novel laser-based scheme for generating atomic-scale charge current loops within femtoseconds. The associated orbital magnetic moments remain ferromagnetically aligned after the laser pulses have ceased and are localized within an area that is tunable via laser parameters and can be chosen to be well below the diffraction limit of the driving laser field. The scheme relies on tuning the phase, polarization, and intensities of two copropagating Gaussian and vortex laser pulses, allowing us to control the spatial extent, direction, and strength of the atomic-scale charge current loops induced in the irradiated sample upon photon absorption. In the experiment we used He atoms driven by an ultraviolet and infrared vortex-beam laser pulses to generate current-carrying Rydberg states and test for the generated magnetic moments via dichroic effects in photoemission. Ab initio quantum dynamic simulations and analysis confirm the proposed scenario and provide a quantitative estimate of the generated local moments.

Shells in CO2 clusters.

Abundance spectra of (CO2)N clusters up to N ≈ 500 acquired under a wide range of adiabatic expansion conditions are analyzed within the evaporative ensemble framework. The analysis reveals that the cluster stability functions display a strikingly universal pattern for all expansion conditions. These patterns reflect the inherent properties of individual clusters. From this analysis the size-dependent cluster binding energies are determined, shell and subshell closing sizes are identified, and cuboctahedral packing ordering for sizes above N ≈ 130 is confirmed. It is demonstrated that a few percent variation in the dissociation energies translates into significant abundance variations, especially for the larger clusters.

Clusters of Fullerenes: Structures and Dynamics.

The geometric structures and reaction dynamics of clusters of carbon fullerene molecules are reviewed. The topics on structure cover the elementary building blocks, the interatomic and intermolecular potentials, and the geometric structures of the aggregates. The dynamics part describes the time development after excitation with laser light, in bimolecular collisions, and in collisions with high energy atomic ions. These reactions produce singly or multiply charged clusters, fragmented or intact fullerene monomers, and fusion products. The duration of the interaction time and the transferred energy are found to play determining roles for the nature of the products. Short interaction times and high energy excitation favor intramolecular reactions on excited potential energy surfaces, producing fused products, often with a strong release of the combined excess energy and heat of fusion. Clusters excited at low energies tend to disintegrate into intact fullerene molecules.

What Determines the Drastic Reactivity of Nbn+ Clusters with Nitric Oxide under Thermalized Conditions?

We report an in-depth study of the adsorption and reaction of NO with cationic Nbn+ (n = 1-20) clusters under thermalized conditions in a laminar flow tube reactor in tandem with a customized triple quadrupole mass spectrometer (FT-TQMS). It is found that the small-sized Nbn+ clusters (2 ≤ n ≤ 7) readily react with NO giving rise to dominant fragmentation products pertaining to the loss of a stable diatomic molecule NbO or NbN. In contrast, the reaction products of larger-sized clusters (n ≥ 10) proceed through diverse channels, including NO adsorption, N2/N2O release, and even NO2 formation. These experimental observations provided the incentive for us to dig deep into the reaction mechanism with the help of DFT calculations. In contrast to the NO-donation coordination in transition metal complexes, here the cationic Nbn+ clusters exhibit dominant electronic donation in initiating the reactions with NO molecules. We fully demonstrated the reaction rate constants, compared the reaction energy diagram of typical Nbn+ clusters, and unveiled the distinct interaction mechanism of niobium clusters available for NO activation and conversion.

Computing gold cluster energies with density functional theory: the importance of correlation.

Energies calculated with density functional theory depend critically on the choice of the exchange-correlation functional. In this work, we use measured dissociation energies of Aun+ (n = 5-17) clusters as benchmark data to test two very different functionals for calculating total energies in these clusters; the simpler (and fast) PBE and the evolved (and expensive) B2PLYP double-hybrid functionals. PBE consistently gives poor agreement with the experimental results. In contrast, the B2PLYP functional, which implicitly includes electron correlation by performing a perturbative second-order correction, significantly improves the agreement of the calculations, at the cost of much more demanding computations. The better performance of the double-hybrid functional is ascribed to the longer range of the interatomic potential.

Cyclotrimerization of Acetylene on Clusters Con+/Fen+/Nin+(n = 1-16).

Cyclotrimerization of acetylene to benzene has attracted significant interest, but the role of geometric and electronic effects on catalytic chemistry remains unclear. To fully elucidate the mechanism of catalytic acetylene-to-benzene conversion, we have performed a gas-phase reaction study of the Fen+, Con+, and Nin+ (n = 1-16) clusters with acetylene utilizing a customized mass spectrometer. It is found that their reactions with acetylene are initiated by C2H2 molecular adsorption and allow for dominant dehydrogenation with the relatively low partial pressure of the acetylene gas. However, at high acetylene concentrations, the cyclotrimerization in Mn+ + 3C2H2 (M = Fe, Co, Ni) becomes the dominant reaction channel. We demonstrate theoretically the favorable thermodynamics and reaction dynamics leading to the formation of the M+(C6H6) products. The results are discussed in terms of a cluster-catalyzed multimolecule synergistic effect and the cation-π interactions.

Effect of 12 weeks continuous positive airway pressure on day and night arterial stiffness and blood pressure in patients with type 2 diabetes and obstructive sleep apnea: A randomized controlled trial.

The objective of this study was to evaluate the effect of continuous positive airway pressure treatment on pulse wave velocity and blood pressure in patients with type 2 diabetes and obstructive sleep apnea. A randomized controlled study was performed, including 72 patients with type 2 diabetes and newly diagnosed obstructive sleep apnea recruited from outpatient clinics at three Danish hospitals. The patients were randomized to continuous positive airway pressure for 12 weeks or no continuous positive airway pressure. Office measurements were performed at baseline, 4 weeks and 12 weeks. At baseline and 12 weeks, a 24-hr measurement of pulse wave velocity and blood pressure was performed. No significant change was observed in the primary outcome variable of carotid-femoral pulse wave velocity measured with SphygmoCor. With the Mobil-O-Graph, changes in office pulse wave velocity between the groups were significant: 0.3 m/s; 95% confidence interval, 0.1-0.6; p = .02. The group receiving continuous positive airway pressure had a larger decrease in pulse wave velocity than controls but none of the changes within the groups were significant. No significant change in ambulatory blood pressure was observed in any of the two groups after 12 weeks. In conclusion, continuous positive airway pressure treatment for 12 weeks does not significantly reduce pulse wave velocity or blood pressure in patients with type 2 diabetes and obstructive sleep apnea.

Gas-phase Förster resonance energy transfer in mass-selected ions with methylene or peptide linkers between two dyes: a concerted dance of charges.

Förster Resonance Energy Transfer (FRET) between a photoexcited and a ground-state dye is dictated by how far apart the two dyes are compared to the Förster distance. While there is a significant number of studies on the process for biomacromolecules in solution, there are only a few reports on gas-phase FRET. Here we report on a simple gas-phase model system, synthesized with the rhodamine 575 (R575+) and rhodamine 640 (R640+) FRET pair and a covalent linker with four methylenes, R575+-(CH2)4-R640+. Each dye carries a positive charge which allows for mass-spectroscopy experiments. We have recorded gas-phase dispersed fluorescence spectra of the mass-selected dications excited at different wavelengths using the homebuilt LUNA (LUminescence iNstrument in Aarhus) setup and find in all cases that emission is exclusively from the R640+ acceptor dye. The linker does not interfere electronically with the dyes and simply acts as a spacer. We can therefore establish the direct effect of the interaction between the two dyes when it comes to emission band maximum. Indeed, we find that R640+ experiences a significant shift in its maximum from 560 ± 1 nm for the monomer cation to 577 ± 2 nm in the presence of R575+, independent of initial excitation of R575+ or R640+. This redshift is ascribed to the large polarizability along the long axis of the xanthene core structure, and that this polarizability is larger in the excited state than in the ground state. Experiments were also done on a triply charged 11-mer peptide labelled with the same two dyes, R575+-(Gly-Gln)5-Lys-R640+ + H+ (Gly = glycine, Gln = glutamine, and Lys = lysine) where the extra positive charge is located on the peptide. Again a redshifted emission spectrum of the donor is observed with maximum at 582 ± 2 nm. Our work clearly demonstrates strong sensitivity of the photophysics of one dye to the nearby environment, and that caution is needed when using the energy transfer efficiency to infer dye-dye separations in gas-phase experiments.

Iodization Threshold in Size-Dependent Reactions of Lead Clusters Pbn+ with Iodomethane.

Utilizing a magnetron-sputtering (MagS) source in tandem with a multiple-ion laminar flow tube (MIFT) reactor and a customized triple quadrupole mass spectrometer (TQMS), we have prepared clean Pbn+ (n = 1-13) clusters and measured their reactivity with iodomethane under high carrier gas pressures. Strong size dependences are found for the reactivity of these cationic Pbn+ clusters with CH3I. For the Pbn+ with n ≤ 4, iodinated clusters PbnI+ were found to be the dominant products, in strong contrast to n > 4 where no such products were seen. Quantum chemical studies show that with an increasing number of Pb atoms, the Pb-Pb interatomic interactions become stronger compared with the Pb-I bonding in PbnI+ clusters. Furthermore, the reactions of Pb1-4+ with CH3I have fairly small transition state energy barriers, in contrast to those for Pbn>4+ clusters which have magnitudes that will prevent reactions under the ambient conditions.

Isotope enrichment in neon clusters grown in helium nanodroplets.

Neon cluster ions Nes + grown in pre-ionized, mass-to-charge selected helium nanodroplets (HNDs) reveal a strong enrichment of the heavy isotope 22Ne that depends on cluster size s and the experimental conditions. For small sizes, the enrichment is much larger than previously reported for bare neon clusters grown in nozzle expansions and subsequently ionized. The enrichment is traced to the massive evaporation of neon atoms in a collision cell that is used to strip helium from the HNDs. We derive a relation between the enrichment of 22Ne in the cluster ion and its corresponding depletion factor F in the vapor phase. The value thus found for F is in excellent agreement with a theoretical expression that relates isotopic fractionation in two-phase equilibria of atomic gases to the Debye temperature. Furthermore, the difference in zero-point energies between the two isotopes computed from F agrees reasonably well with theoretical studies of neon cluster ions that include nuclear quantum effects in the harmonic approximation. Another fitting parameter provides an estimate for the size si of the precursor of the observed Nes +. The value is in satisfactory agreement with the size estimated by modeling the growth of Nes + and with lower and upper limits deduced from other experimental data. On the other hand, neon clusters grown in neutral HNDs that are subsequently ionized by electron bombardment exhibit no statistically significant isotope enrichment at all. The finding suggests that the extent of ionization-induced dissociation of clusters embedded in HNDs is considerably smaller than that for bare clusters.