Reform design, institutional and workforce factors affecting the pace of change

Background

When implementing health care reforms the pace of change is often lacking behind the expectations of policy makers. This research is exploring in-depth the experiences of a primary care initiative from the perspective of general practitioners. The physicians' perspectives on design features, supporting environment and acceptance of the pilot are being explored. Enabling and constraining factors that may influence the pace of change of health care reforms are identified. Implications can be drawn for the strategic planning and smooth implementation of the change process.

Methods

14 problem-focused interviews with general practitioners working in pilot projects and 2 focus group discussions with 4-6 general practitioners working in single practices have been conducted. In addition, document analysis of secondary qualitative data and relevant policy documents has been conducted.

Results

Analysis revealed 9 codes: (1) Status of the general practitioner; (2) Institutional and legal framework; (3) Between cooperation and competition; (4) Hesitation from the young generation; (5) Reluctance from sole practitioners; (6) Personal drivers for starting a pilot (7) Challenges during set-up phase; (8) Challenges during growth phase; (9) Working conditions in primary care pilot projects. Enabling factors were a strong desire to be pioneering primary care provision and improved working conditions. The main constraining factors were low status of the general practitioner, uncertainty about future directions, lack of information and advice, high perceived financial risk, fear of losing autonomy and uncertainty about functioning teamwork.

Conclusions

For a smooth implementation of the primary care reform, system changes should improve education and training, compensation schemes and competence profiles of the professional groups involved. Further, initiatives should provide information and advice for practitioners striving for participating in a pilot project.

Key messages

The success of health care reforms also depends on institutional and workforce factors that may affect the pace of change. Health care reforms need strategic planning for a smooth implementation.

Structural properties of ultra-small thorium and uranium dioxide nanoparticles embedded in a covalent organic framework

We report the structural properties of ultra-small ThO2 and UO2 nanoparticles (NPs), which were synthesized without strong binding surface ligands by employing a covalent organic framework (COF-5) as an inert template. The resultant NPs were used to observe how structural properties are affected by decreasing grain size within bulk actinide oxides, which has implications for understanding the behavior of nuclear fuel materials. Through a comprehensive characterization strategy, we gain insight regarding how structure at the NP surface differs from the interior. Characterization using electron microscopy and small-angle X-ray scattering indicates that growth of the ThO2 and UO2 NPs was confined by the pores of the COF template, resulting in sub-3 nm particles. X-ray absorption fine structure spectroscopy results indicate that the NPs are best described as ThO2 and UO2 materials with unpassivated surfaces. The surface layers of these particles compensate for high surface energy by exhibiting a broader distribution of Th-O and U-O bond distances despite retaining average bond lengths that are characteristic of bulk ThO2 and UO2. The combined synthesis and physical characterization efforts provide a detailed picture of actinide oxide structure at the nanoscale, which remains highly underexplored compared to transition metal counterparts.

P1836 Common carotid artery intima-media thickness correlates with the epicardial fat thickness in patients with ischemic stroke

Purpose

The aim of this study was to determine the relationship between common carotid artery intima–media thickness (CCA-IMT), the resistance index (RI) in the vertebral and carotid arteries and epicardial fat thickness (EFT) in patients with ischemic stroke.

Methods

98 patients with ischemic stroke (31 females and 67 males, mean age was 68.2 ± 12.1 years) were studied. All patients had arterial hypertension (AH). Most of them (96.9%) had grade 3 hypertension according to ESH/ESC Guidelines for the management of arterial hypertension, 2018. Forty-two (43.1%) patients had coronary artery disease and 35 (35.4%) - atrial fibrillation (AF). The exclusion criteria was the presence of chronic obstructive pulmonary disease or other diseases associated with pulmonary hypertension. Patients were categorized according to National Institutes of Health Stroke Scale (NIHSS) severity in mild NIHSS (≤8) - 54 (55.1%) patients, moderate NIHSS (9–15) - 23 (23.5%) patients, and severe stroke NIHSS (≥16) - 21 (21.4%) patients. Median NIHSS score was 11.2 ± 1.7. All patients underwent a transthoracic echocardiography and a carotid ultrasound examination.

Results

The common carotid artery intima–media thickness correlated with EFT (r =0.78, p < 0.001), the body mass index (r = 0.7, p < 0.001) and systolic blood pressure (r = 0.25, p = 0.045). The resistance index in the vertebral and carotid arteries correlated only with EFT (r = 0.7, p < 0.001 and r = 0.78, p < 0.001, respectively) and body mass index (r = 0.58, p < 0.001 and r = 0.68, p < 0.001, respectively).

A multiple regression analysis in which the CCA-IMT was a dependent variable and age, body mass index, systolic blood pressure, blood cholesterol level and epicardial fat thickness were independent variables, showed that CCA-IMT was independently correlated with blood cholesterol level (β=0.714, р<0.001) and EFT (β =0.255, р=0.002) in patients with ischemic stroke.

Conclusions

The common carotid artery intima–media thickness and parameters of the arterial stiffness of the extracranial vessels of the head are associated with the epicardial fat thickness and blood cholesterol level in patients with ischemic stroke. The common carotid artery intima–media thickness does not depend on age, gender, body mass index, systolic and diastolic blood pressure in patients with ischemic stroke.

P1837 The severity of acute ischemic stroke is associated with the right heart remodeling in patients with arterial hypertension

Purpose

The aim of this study was to determine the relationship of echocardiographic signs of the right heart remodeling and the stroke severity in patients with arterial hypertension and ischemic stroke.

Methods

98 patients with acute ischemic stroke (31 females and 67 males, mean age was 68.2 ± 12.1 years) were studied. All patients had arterial hypertension. Most of them (96.9%) had grade 3 hypertension according to ESH/ESC Guidelines for the management of arterial hypertension, 2018. Forty-two (43.1%) patients had coronary artery disease, 35 (35.4%) - atrial fibrillation (AF). The exclusion criteria was the presence of chronic obstructive pulmonary disease or other diseases associated with pulmonary hypertension. Patients were categorized according to National Institutes of Health Stroke Scale (NIHSS) severity in mild NIHSS (≤8) - 54 (55.1%) patients, moderate NIHSS (9–15) - 23 (23.5%) patients, and severe stroke NIHSS (≥16) - 21 (21.4%) patients. Median NIHSS score was 11.2 ± 1.7. All patients underwent a transthoracic echocardiography. A comparative assessment of echocardiographic parameters was performed in patients of lower (NIHSS score ≤ 4.5) and upper (NIHSS score≥14.5) quartile according to the NIHSS score.

Results

Linear regression analysis revealed that stroke severity was significantly correlated with right atrium end-diastolic volume (EDV) (r = 0.48, p < 0.0001), right ventricular EDV (r = 0.62, p < 0.0001), left atrium EDV (r = 0.41, p = 0.002), left ventricular ejection fraction (LVEF) (r = 0.4, p = 0.003) and pulmonary artery systolic pressure (PASP) (r = 0.89, p < 0.0001). A multiple regression analysis showed that stroke severity was independently correlated with PASP (β=0.471, р=0.01), left atrium EDV (β=0.961, р=0.02) and LVEF (β=0.931, р=0.005) in patients with arterial hypertension and ischemic stroke.

In the group of patients with the upper quartile of NIHSS score, the right atrium EDV (64.7 ± 21.1 mm versus 47.6 ± 25.2 mm, р=0.04) and PASP (25.8 ± 9.3 mm versus 20.8 ± 8.0 mm, р=0.045) were higher. The left atrium EDV was higher in patients with LVEF below 50% ( 73.3 ± 36.9 mm vs 49.9 ± 18.5 mm, р=0.02) and in patients with AF (55.3 ± 19.8 vs 36.4 ± 14.6 mm, p < 0.0001). At the same time PASP did not depend on the LVEF (22.1 ± 10.7 mm vs 21.6 ± 8.1 mm, р=0.9) and the presence of AF (21.9 ± 9.0 mm vs 21.7 ± 8.1 mm, р=0.9).

Conclusions

In patients with arterial hypertension the severity of acute ischemic stroke is associated with increases in right atrium end-diastolic volume and in pulmonary artery systolic pressure. An increase in pulmonary artery systolic pressure in patients with arterial hypertension and ischemic stroke does not depend on the left ventricular ejection fraction and atrial fibrillation.

Tuning the Geometric and Electronic Structure of Synthetic High-Valent Heme Iron(IV)-Oxo Models in the Presence of a Lewis Acid and Various Axial Ligands

High-valent ferryl species (e.g., (Por)Fe^IV═O, Cmpd-II) are observed or proposed key oxidizing intermediates in the catalytic cycles of heme-containing enzymes (P-450s, peroxidases, catalases, and cytochrome c oxidase) involved in biological respiration and oxidative metabolism. Herein, various axially ligated iron(IV)-oxo complexes were prepared to examine the influence of the identity of the base. These were generated by addition of various axial ligands (1,5-dicyclohexylimidazole (DCHIm), a tethered-imidazole system, and sodium derivatives of 3,5-dimethoxyphenolate and imidazolate). Characterization was carried out via UV-vis, electron paramagnetic resonance (EPR), ⁵⁷Fe Mössbauer, Fe X-ray absorption (XAS), and ^54/57Fe resonance Raman (rR) spectroscopies to confirm their formation and compare the axial ligand perturbation on the electronic and geometric structures of these heme iron(IV)-oxo species. Mössbauer studies confirmed that the axially ligated derivatives were iron(IV) and six-coordinate complexes. XAS and ^54/57Fe rR data correlated with slight elongation of the iron-oxo bond with increasing donation from the axial ligands. The first reported synthetic H-bonded iron(IV)-oxo heme systems were made in the presence of the protic Lewis acid, 2,6-lutidinium triflate (LutH⁺), with (or without) DCHIm. Mössbauer, rR, and XAS spectroscopic data indicated the formation of molecular Lewis acid ferryl adducts (rather than full protonation). The reduction potentials of these novel Lewis acid adducts were bracketed through addition of outer-sphere reductants. The oxidizing capabilities of the ferryl species with or without Lewis acid vary drastically; addition of LutH⁺ to F₈Cmpd-II (F₈ = tetrakis(2,6-difluorophenyl)porphyrinate) increased its reduction potential by more than 890 mV, experimentally confirming that H-bonding interactions can increase the reactivity of ferryl species.

Site-specific gene expression analysis from archived human intestine samples combining laser-capture microdissection and multiplexed color-coded probes

BACKGROUND

Alterations of site-specific gene expression profiles in disease-relevant networks within the different layers of the intestinal wall may contribute to the onset and clinical course of gastrointestinal disorders. To date, no systematic analysis has assessed and compared sub-regional gene expression patterns in all distinct layers of the gut using fresh frozen human samples. Our aim was to establish an optimized protocol for site-specific RNA isolation in order to achieve maximum RNA quality and amount for subsequent gene expression analysis combining laser-capture microdissection (LCM) with a probe-based technology, the NanoString nCounter Analysis system.

METHODS

Four full-thickness colon samples from patients who underwent surgery due to pathological conditions were processed and separated into epithelium, lamina propria, myenteric plexus, submucosa, and tunica muscularis by LCM. Site-specific marker expression by nCounter technology was performed on total RNA from each sub-region, respectively.

KEY RESULTS

Collecting ~10 mm² (~100 000-250 000 cells) of tissue from the epithelial layer, lamina propria, and myenteric plexus provided sufficient amounts of RNA of appropriate quality for subsequent analyses. In contrast, ~40 mm² (~250 000-650 000 cells) of tissue were dissected from the less cell-rich submucosal and tunica muscularis layer. nCounter analysis revealed a site-specific expression pattern of marker genes in the different layers of the colonic wall which were highly correlating (r > .9).

CONCLUSIONS AND INFERENCES

LCM in combination with nCounter expression analysis enables site-specific, sensitive, reliable detection, and quantification of mRNA from histologically heterogeneous tissues.

Lamin B1 regulates somatic mutations and progression of B-cell malignancies

Somatic hypermutation (SHM) is a pivotal process in adaptive immunity that occurs in the germinal centre and allows B cells to change their primary DNA sequence and diversify their antigen receptors. Here, we report that genome binding of Lamin B1, a component of the nuclear envelope involved in epigenetic chromatin regulation, is reduced during B-cell activation and formation of lymphoid germinal centres. Chromatin immunoprecipitation-Seq analysis showed that kappa and heavy variable immunoglobulin domains were released from the Lamin B1 suppressive environment when SHM was induced in B cells. RNA interference-mediated reduction of Lamin B1 resulted in spontaneous SHM as well as kappa-light chain aberrant surface expression. Finally, Lamin B1 expression level correlated with progression-free and overall survival in chronic lymphocytic leukaemia, and was strongly involved in the transformation of follicular lymphoma. In summary, here we report that Lamin B1 is a negative epigenetic regulator of SHM in normal B-cells and a 'mutational gatekeeper', suppressing the aberrant mutations that drive lymphoid malignancy.

Chemical and Morphological Inhomogeneity of Aluminum Metal and Oxides from Soft X-ray Spectromicroscopy

Oxygen and aluminum K-edge X-ray absorption spectroscopy (XAS), imaging from a scanning transmission X-ray microscope (STXM), and first-principles calculations were used to probe the composition and morphology of bulk aluminum metal, α- and γ-Al₂O₃, and several types of aluminum nanoparticles. The imaging results agreed with earlier transmission electron microscopy studies that showed a 2 to 5 nm thick layer of Al₂O₃ on all the Al surfaces. Spectral interpretations were guided by examination of the calculated transition energies, which agreed well with the spectroscopic measurements. Features observed in the experimental O and Al K-edge XAS were used to determine the chemical structure and phase of the Al₂O₃ on the aluminum surfaces. For unprotected 18 and 100 nm Al nanoparticles, this analysis revealed an oxide layer that was similar to γ-Al₂O₃ and comprised of both tetrahedral and octahedral Al coordination sites. For oleic acid-protected Al nanoparticles, only tetrahedral Al oxide coordination sites were observed. The results were correlated to trends in the reactivity of the different materials, which suggests that the structures of different Al₂O₃ layers have an important role in the accessibility of the underlying Al metal toward further oxidation. Combined, the Al K-edge XAS and STXM results provided detailed chemical information that was not obtained from powder X-ray diffraction or imaging from a transmission electron microscope.

Attosecond physics at the nanoscale

Recently two emerging areas of research, attosecond and nanoscale physics, have started to come together. Attosecond physics deals with phenomena occurring when ultrashort laser pulses, with duration on the femto- and sub-femtosecond time scales, interact with atoms, molecules or solids. The laser-induced electron dynamics occurs natively on a timescale down to a few hundred or even tens of attoseconds (1 attosecond  =  1 as  =  10^-18 s), which is comparable with the optical field. For comparison, the revolution of an electron on a 1s orbital of a hydrogen atom is  ∼152 as. On the other hand, the second branch involves the manipulation and engineering of mesoscopic systems, such as solids, metals and dielectrics, with nanometric precision. Although nano-engineering is a vast and well-established research field on its own, the merger with intense laser physics is relatively recent. In this report on progress we present a comprehensive experimental and theoretical overview of physics that takes place when short and intense laser pulses interact with nanosystems, such as metallic and dielectric nanostructures. In particular we elucidate how the spatially inhomogeneous laser induced fields at a nanometer scale modify the laser-driven electron dynamics. Consequently, this has important impact on pivotal processes such as above-threshold ionization and high-order harmonic generation. The deep understanding of the coupled dynamics between these spatially inhomogeneous fields and matter configures a promising way to new avenues of research and applications. Thanks to the maturity that attosecond physics has reached, together with the tremendous advance in material engineering and manipulation techniques, the age of atto-nanophysics has begun, but it is in the initial stage. We present thus some of the open questions, challenges and prospects for experimental confirmation of theoretical predictions, as well as experiments aimed at characterizing the induced fields and the unique electron dynamics initiated by them with high temporal and spatial resolution.

Synthesis of (18) F-Difluoromethylarenes from Aryl (Pseudo) Halides

A general method for the synthesis of [(18) F]difluoromethylarenes from [(18) F]fluoride for radiopharmaceutical discovery is reported. The method is practical, operationally simple, tolerates a wide scope of functional groups, and enables the labeling of a variety of arenes and heteroarenes with radiochemical yields (RCYs, not decay-corrected) from 10 to 60 %. The (18) F-fluorination precursors are readily prepared from aryl chlorides, bromides, iodides, and triflates. Seven (18) F-difluoromethylarene drug analogues and radiopharmaceuticals including Claritin, fluoxetine (Prozac), and [(18) F]DAA1106 were synthesized to show the potential of the method for applications in PET radiopharmaceutical design.

Transfer characteristics of subretinal visual implants: corneally recorded implant responses

PURPOSE

The subretinal Alpha IMS visual implant is a CE-approved medical device for restoration of visual functions in blind patients with end-stage outer retina degeneration. We present a method to test the function of the implant objectively in vivo using standard electroretinographic equipment and to assess the devices' parameter range for an optimal perception.

METHODS

Subretinal implant Alpha IMS (Retina Implant AG, Reutlingen, Germany) consists of 1500 photodiode-amplifier-electrode units and is implanted surgically into the subretinal space in blind retinitis pigmentosa patients. The voltages that regulate the amplifiers' sensitivity (V _gl) and gain (V _bias), related to the perception of contrast and brightness, respectively, are adjusted manually on a handheld power supply device. Corneally recorded implant responses (CRIR) to full-field illumination with long duration flashes in various implant settings for brightness gain (V _bias) and amplifiers' sensitivity (V _gl) are measured using electroretinographic setup with a Ganzfeld bowl in a protocol of increasing stimulus luminances up to 1000 cd/m².

RESULTS

CRIRs are a meaningful tool for assessing the transfer characteristic curves of the electronic implant in vivo monitoring the implants' voltage output as a function of log luminance in a sigmoidal shape. Changing the amplifiers' sensitivity (V _gl) shifts the curve left or right along the log luminance axis. Adjustment of the gain (V _bias) changes the maximal output. Contrast perception is only possible within the luminance range of the increasing slope of the function.

CONCLUSIONS

The technical function of subretinal visual implants can be measured objectively using a standard electroretinographic setup. CRIRs help the patient to optimise the perception by adjusting the gain and luminance range of the device and are a useful tool for clinicians to objectively assess the function of subretinal visual implants in vivo.