Search

Phase development and changes in crystalline composition of LTCC material during the sintering process were investigated using in-situ X-ray diffraction (XRD) measurements. CeramTape GC was chosen as the chemically simplest model system composed of alumina particles and glass for the investigations. The chemical characterization and microstructural analyses of the tapes sintered with some representative firing profiles were performed by techniques such as (scanning) transmission electron microscope, energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and XRD. Moreover, the porosification behavior of LTCC substrates fired at different peak temperatures was studied. These investigations are important for the subsequent wet chemical etching, representing an approach which allows to reduce locally the permittivity of LTCC tapes. Treatment with a KOH solution shows non-selective etching behavior for all substrates. In addition, highly porous silica structures corresponding to Ca and Al depletion from the anorthite phase were observed in all samples after etching treatment. [ABSTRACT FROM AUTHOR]

The effect of phase transformation kinetics on the formation of α in the β-quenched Ti–5Al–5Mo–5V–3Cr–1Zr metastable β titanium alloy is investigated as a function of heating rate by means of in situ high energy synchrotron X-ray diffraction complemented by metallographic analysis. Quantitative phase analysis based on the Rietveld method provides the continuous evolution of phase volume fractions and lattice parameters, revealing variations in the phase transformation sequence with increasing heating rate. The initial microstructure consists in a matrix of equiaxed metastable β grains with ω ath particles located along dislocation lines as well as within domains associated with spinodal decomposition of β. During the first stage of slow heating diffusion-driven formation of the metastable phases ω and α iso ″ takes place with further decomposition of β. This effect contributes to the formation of ω and is observed as a symmetric pattern of parallel domains that reflect compositional modulations in the matrix. Evidences of the role of dislocations during phase transformation are presented. Furthermore, the results show that the stable α phase forms via two different paths: (a) slow heating rates provide homogeneous distribution of fine α plates formed through the evolution of ω, while (b) fast heating rates suppress this mechanism and promote the formation of α only from β grain boundaries. [ABSTRACT FROM AUTHOR]

Mature seeds of both the high-starch starch-excessl (sex1) mutant and the almost starchless phosphoglucomutasel mutant of Arabidopsis (Arabidopsis thaliana) have 30% to 40% less lipid than seeds of wild-type plants. We show that this is a maternal effect and is not attributable to the defects in starch metabolism in the embryo itself. Low lipid contents and consequent slow postgerminative growth are seen only in mutant embryos that develop on maternal plants with mutant phenotypes. Mutant embryos that develop on plants with wild-type starch metabolism have wild-type lipid contents and postgerminative growth. The maternal effect on seed lipid content is attributable to carbohydrate starvation in the mutant fruit at night. Fruits on sex1 plants grow more slowly than those on wild-type plants, particularly at night, and have low sugars and elevated expression of starvation genes at night. Transcript levels of the transcription factor WRINKLED1, implicated in lipid synthesis, are reduced at night in sex1 but not in wild-type seeds, and so are transcript levels of key enzymes of glycolysis and fatty acid synthesis, sex1 embryos develop more slowly than wild-type embryos. We conclude that the reduced capacity of mutant plants to convert starch to sugars in leaves at night results in low nighttime carbohydrate availability in the developing fruit. This in turn reduces the rate of development and expression of genes encoding enzymes of storage product accumulation in the embryo. Thus, the supply of carbohydrate from the maternal plant to the developing fruit at night can have an important influence on oilseed composition and on postgerminative growth. [ABSTRACT FROM AUTHOR]

• Noble metal promotion in Cu-doped LaMnO 3 catalysts changes electronic structure. • Promotion changes the reducibility of B-site cations Cu and Mn. • Promotion leads to strong surface depletion of noble metal deviating from bulk value. • Noble metal promotion strongly influences the redox properties of the perovskites. • Low amounts of noble metals in surface regions improve the NO reduction by CO. To evaluate the structural and spectroscopic steering factors of noble metal promotion in the catalytic reduction of NO by CO, a series of La(Cu 0.7 Mn 0.3) 0.98 M 0.02 O 3−δ (M = Pd, Pt, Ru, Rh) perovskite catalysts is investigated. The materials are synthesized by a sol-gel method and characterized by X-ray powder diffraction (XRD), electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). All metal-promoted perovskites exhibit a comparatively higher activity for catalytic reduction of NO by CO with respect to pure La(Cu 0.7 Mn 0.3)O 3−δ. Among all catalysts tested, the La(Cu 0.7 Mn 0.3) 0.98 Pd 0.02 O 3−δ perovskite shows the highest catalytic activity, which is tentatively related to a combined synergistic effect of improved oxygen vacancy activity and noble metals. Additionally, the redox chemistry of the catalysts in different reducing (H 2) and oxidizing (NO, O 2) atmospheres is tested. An enhanced kinetic reducibility, especially with Pd, was observed. All the H 2 -reduced catalysts are capable of reducing NO. At low and intermediate temperatures, the formation of N 2 O is observed, but at higher temperatures NO is exclusively converted to N 2. The introduction of noble metals leads to new adsorption sites for NO. As XPS suggests a tendency for depletion of noble metals in the surface-near regions, while the catalytic activity in NO reduction at the same time appears much improved, directed noble metal promotion with modest amounts especially in surface-near regions during synthesis appears as an encouraging method to economize the use of the latter. [ABSTRACT FROM AUTHOR]

Proper design of the heat treatments of metallic materials is crucial for creating a suitable microstructure resulting in the desired properties. In this paper, we present a multi-component simulation procedure for the quantitative prediction of yield strength, fracture strain, and fracture toughness of precipitation-hardened alloys, with special emphasis on Al–Mg–Si alloys. The procedure combines thermokinetic and micromechanical models, taking the microstructural information in terms of different populations of various second-phase particles into account. The predictions are compared to the results of experiments performed on AA6082 samples subjected to different artificial aging times, and good quantitative agreement is demonstrated. [ABSTRACT FROM AUTHOR]

Characterization of Mg-Si precipitates is crucial for optimizing the homogenization heat treatment of Al-Mg-Si alloys. Although sample preparation is key for high quality scanning electron microscopy imaging, most common methods lead to dealloying of Mg-Si precipitates. In this article we systematically evaluate different sample preparation methods: mechanical polishing, etching with various reagents, and electropolishing using different electrolytes. We demonstrate that the use of a nitric acid and methanol electrolyte for electropolishing a homogenized Al-Mg-Si alloy prevents the dissolution of Mg-Si precipitates, resulting in micrographs of higher quality. This preparation method is investigated in depth and the obtained scanning electron microscopy images are compared with transmission electron micrographs: the shape and size of Mg-Si precipitates appear very similar in either method. The scanning electron micrographs allow proper identification and measurement of the Mg-Si phases including needles with lengths of roughly 200 nm. These needles are β″ precipitates as confirmed by high resolution transmission electron microscopy. [ABSTRACT FROM AUTHOR]

Using pure YSZ and Ni-doped YSZ materials we provide a direct comparison of the morphology and specific growth mechanisms of carbon deposits following treatment in CO as the common component of reformate gas fuels at temperatures up to 1273 K. Under these experimental conditions, carbon is deposited on both constituents following distinctly different pathways: metallic Ni particles are both encapsulated and subsequently act as catalysts for growth of carbon filaments – leading to chemically and electronically altered Ni particles. In contrast to that, also pure YSZ oxide particles are without exception only encapsulated by distorted graphitic layers of up to 2–3 individual layers. This carbon layer is not formed by carbon spillover from the Ni particle, but directly deposited on the oxide grains by CO dissociation. While the pathway over the metallic component is dominant at high Ni loadings, the oxide especially at lower loadings can contribute directly to the structural and chemical alterations of the electrode material by changing the physico-chemical properties, e.g. by altering the conductivity via C-deposition at the intergrain regions or may also serve as additional carbon supply for re-distributed and dispersed “dusted” Ni particles attached to the carbon-covered YSZ grains. [ABSTRACT FROM AUTHOR]

We steer the catalytic performance and morphology of Pd – lanthanum iron manganite (LFM) perovskite interfaces towards optimum NO+CO reactivity in presence of water by following different preparation approaches. Strong CO adsorption for samples without Pd-perovskite interface acts as an inhibitor for adsorption/dissociation of NO, while samples with an extended interface, additionally aided by H 2 O, show reduced CO poisoning. The optimized use of lattice oxygen for CO oxidation at the phase boundary and its replenishment from NO dissociation allows for the formation of more poisoning-resistant active sites for NO activation. Reaction of species from H 2 O dissociation with adsorbed CO assists further surface clean off. Enhanced NO reduction activity on the "de-poisoned" interface leads to a pronounced increase in N 2 selectivity. Preferred production of NH 3 at low NO and high CO and H 2 O concentration indicates that water gas shift intermediates are linked to increased surface hydrogen activity and increased NH 3 formation. [Display omitted] • Synthesis approach tunes the extent of Pd-perovskite interface. • Effect of the interface dimensions on deNO x reactivity in the presence of H 2 O. • Reaction of H 2 O species with adsorbed CO assists surface de-poisoning. • Effective use of lattice oxygen for CO oxidation at the phase boundary. • Water gas shift intermediates causes enhanced NH 3 formation. [ABSTRACT FROM AUTHOR]

Abstract: Within a prospective protocol, the incidence and impact of achievement of molecular remission (mCR) and high-risk cytogenetics was investigated in 73 patients with multiple myeloma (MM) after autologous (auto)–allogeneic (allo) tandem stem cell transplantation (SCT). After induction chemotherapy, patients received melphalan 200 mg/m2 before undergoing auto-SCT, followed 3 months later by melphalan 140 mg/m2 and fludarabine 180 mg/m2 before allo-SCT. Sixteen patients had high-risk cytogenetic features, defined by positive FISH for del(17p13) and/or t(4;14). Overall, 66% of the patients achieved CR or near-CR, and 41% achieved mCR, which was sustained negative (at least 4 consecutive samples negative) in 15 patients (21%), with no significant difference in incidence between the patients with high-risk cytogenetics and others (P = .70). After a median follow-up of 6 years, overall 5-year progression-free survival was 29%, with no significant difference between del 17p13/t(4;14)-harboring patients and others (24% versus 30%; P = .70). The 5-year progression-free survival differed substantially according to the achieved remission: 17% for partial remission, 41% for CR, 57% for mCR, and 85% for sustained mCR. These results suggest that auto–allo tandem SCT may overcome the negative prognostic effect of del(17p13) and/or t(4;14) and that achievement of molecular remission resulted in long-term freedom from disease. [Copyright &y& Elsevier]

[Display omitted] We present a combined experimental and computational investigation of phase stability and mechanical properties in the Al-Cu-Mg-Zn quaternary system. Samples containing different relative compositions were prepared using magnetron sputtering and investigated by electron microscopic and X-ray based methods. To classify the technical relevance of the samples, the indentation hardness was measured. The phase stability was studied computationally using a cluster expansion approach based on density functional theory (DFT) methods in a comprehensive screening of the structural and stoichiometric configuration space. Upon decreasing Cu concentration, a transition from an FCC to a mixed FCC/BCC crystal system and significant changes in the mechanical properties depending on Valence Electron Concentration (VEC) and atomic size differences (δ r) was observed experimentally. The corresponding crystallographic phases were assigned by XRD and the experimentally observed phase transition was confirmed by the computational screening of formation energies. Since to date, quaternary complex light metal alloy systems cannot be reliably predicted, this is an important step towards a priori modelling of this class of materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The adhesion strength of AlN/Si as the weakest interface in an optoelectronic GaN based system is successfully determined for the first time. • The interfacial fracture energy of the AlN/Si interface is strongly dependent on the layer design and microstructure yielding energy release rates between 2.8 J/m2 and 13.6 J/m2. • Cross-sectional nanoindentation and four-point bending delamination tests revealed comparable local and large area interfacial fracture energy values. • The probability of interfacial delamination or cohesive fracture in multilayers can be predicted by the proposed analytical model, allowing optimized thin film design. Wide bandgap semiconductors such as group III-nitrides and SiC are considered as key materials for the fabrication of smaller, more reliable and efficient power electronics. Fabrication of robust and durable power devices requires an optimized design based on the understanding of the interfacial adhesion properties of the constituent thin-film heterostructures. In this study, the adhesion properties of GaN/AlN layers grown on Si substrates were investigated. Particularly, the influence of the AlN buffer layers, necessary for GaN growth on Si, on the delamination response was determined. The interfacial adhesion strength was obtained using cross-sectional nanoindentation (CSN) and four-point bending (4PB) tests. Analytical models based on beam- and elastic plate theory which were applied respectively to calculate the interfacial fracture energy (G ic) for both methods are found to be in good agreement provided the loading conditions are similar. Detailed transmission and scanning electron microscopy investigations prior and subsequent to delamination reveal the microstructural details of the relevant interfaces and provide insights into the encountered mechanisms of interfacial failure. Finally, the probability of delamination along the weakest interface is discussed based on a fracture mechanics model. [ABSTRACT FROM AUTHOR]

Abstract: Electron-microscopy suitable In2O3 thin films prepared by thermal deposition of In2O3 powder in 10−2 Pa O2 at 600K and, for comparison, a commercial polycrystalline In2O3 powder catalyst were tested in methanol steam reforming and in both routes of the water–gas shift reaction as a function of reaction temperature. The effect of oxidative (1bar O2, 373–673K, 1h) and reductive (1bar H2, 373–673K, 1h) catalyst pre-treatments was assessed. The resulting structural and morphological changes occurring during catalyst activation and catalytic reaction were monitored by (high-resolution) transmission electron microscopy, scanning electron microscopy and surface area measurements by N2 adsorption according to BET. Both the In2O3 thin film and the powder sample were observed to be structurally stable under typical catalyst pre-treatments in oxygen and hydrogen at temperatures T ≤673K and T <673K, respectively, as well as under typical methanol steam reforming conditions at temperatures T ≤680K. No pronounced catalyst sintering was observed below 673K. Both In2O3 samples were found to be highly active and selective toward CO2 in methanol steam reforming over a broad temperature range (450< T <673K). Selectivities of >95% toward CO2 were usually observed, with at maximum 5% or less CO formed. No dependence of selectivity on either reaction temperature or oxidative/reductive pre-treatment was observed. No catalytic activity in both routes of the water–gas shift reaction as tested in the same temperature region where the catalysts exhibit high reforming activity and selectivity, could be observed. Therefore In2O3 based catalysts offer a broad range of temperature not influenced by unwanted CO formation via the inverse water–gas shift process. [Copyright &y& Elsevier]

[Display omitted] • Strong influence of the Cu-ZrO 2 interface dimensions on the CO 2 selectivity in MSR. • Variation of Cu loading shows intrinsic contributions of ZrO 2 and Cu surface fraction. • ZrO 2 is an active support in methanol steam reforming. • ZrO 2 influences all reaction channels of the overall reaction mechanism. • Cu-ZrO 2 interfacial dimensions are independent of structural effects. On Cu/ZrO 2 catalysts, variation of the Cu loading from 0.2 wt% to 80 wt% allows assessing the influence of the Cu-ZrO 2 interface on the methanol steam reforming (MSR) performance by steering Cu particle size and morphology, revealing the contribution of potential active sites at the interface and the intrinsic relative contributions of the support and Cu surface fraction. As ZrO 2 influences both CO 2 -selective and selectivity-spoiling MSR reaction channels, disentangling support-specific effects from the special phase-boundary reactivity and the intrinsic Cu° reactivity is possible by our approach. By choosing a broad range of Cu loadings, a comparison of the most extreme cases of strong predominance of bulk-like Cu sites (80 wt% Cu) vs. highly dispersed Cu (0.2 wt%), dominated by interfacial and support reactivity, becomes accessible. Cu (80 wt%)/ZrO 2 evolves as the best MSR catalyst by avoiding adverse support effects and providing a high number of support-wetting bulk-like Cu sites. [ABSTRACT FROM AUTHOR]

The wireless high-frequency technology requires a robust, cost-effective, and highly integrated substrate technology offering the capability for areas of tailored permittivity. The wet-chemical porosification of low temperature co-fired ceramics (LTCC) substrates offers such an approach by locally embedding air. Porosification of LTCC in both extremely acidic and alkaline media has been investigated in previous works. However, for improving the available knowledge on the porosification of LTCC with H 3 PO 4 as a standard and a widely used etching solution, the impact of solution concentration was systematically investigated and a substantial improvement in the etching performance was achieved. Moreover, in the present study, for the first time, the intermediate pH values, and the impact of pH as a key parameter on the etching process have been investigated. For this purpose, the applicability of phosphate buffer solution (PBS) as a prospective novel etchant mixture for the porosification of a commercially available LTCC tape (Ceramtape GC) was explored. Valuable information about surface morphology, crystalline composition, and the pore structure of the etched LTCCs was gathered employing scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, and mercury porosimetry measurements. Based on these findings, the performance of PBS-based etchant systems towards the generation of porous LTCCs combining high depths of porosification with acceptable surface characteristics for subsequent metallization is demonstrated. Based on the obtained results, by application of a 0.2 mol L−1 solution of PBS, the effective relative permittivity of test samples with a thickness of approximately 600 µm and a porosification depth of 186 µm from each side, could be reduced up to 10% of its initial " as fired " value. Also, based on the measurement results and by measuring the depth of porosification, the permittivity of the etched layer was estimated to show a reduction of up to 22% compared to the initial " as fired " value. • Employing the wet chemical etching process for permittivity reduction of commercially available LTCC tapes. • Introduction of phosphate buffer solution as a novel etchant for the etching treatment of LTCC substrates. • Detailed studies on the impact of etchant pH and concentration on the etching process. • Tailoring porosification degree and the corresponding depth of porosification by a careful selection of etching parameters. • Kinetics and mechanism of the etching process. [ABSTRACT FROM AUTHOR]

• Schottky barrier height could be increased up to 49% using interlayers and annealing. • Effects of interface inhomogeneities after annealing are reduced using interlayers. • Enhanced Ti5Si3 alloy formation using amorphous a-SiC:H interlayers. The possibility of Schottky barrier height (SBH) modulation of conventional Ti/4H-SiC Schottky diodes by inserting an ultrathin a-SiC:H layer and the influence of annealing at 600 °C are investigated. Amorphous SiC:H layers between 0.7 and 4 nm thickness were grown on the 4H-SiC surface using plasma-enhanced chemical vapor deposition prior to Ti deposition. Diode properties are extracted using current-voltage and capacitance-voltage measurements between 300 and 450 K and compared to conventional Ti/4H-SiC diodes. Transmission electron microscopy and X-ray diffraction were applied to investigate the microstructure of as-deposited and annealed diodes. The integration of an a-SiC:H interface layer in combination with thermal annealing resulted in very ideal diode characteristics, whereas the duration of the annealing can be used to adjust the SBH. A room temperature SBH range between 0.78 and 1.16 V could be covered using different interface layer thicknesses and annealing durations. [ABSTRACT FROM AUTHOR]

Low temperature co-fired ceramics (LTCC) technology has been successfully used in microelectronics, automotive, and telecommunication applications. However, their generally high permittivity is unfavorable for micromachined devices operated at high frequencies. To overcome this drawback, we have established a wet-chemical etching process as an effective approach which can be applied to LTCC substrates in their as-fired state and allows for a local permittivity reduction in regions of interest. Understanding the etching mechanism is essential for the selection of appropriate etching conditions to control the degree of porosification. Therefore, in the present work, we report on an effective approach to achieve a tailored porosification of LTCC substrates. Different characterization techniques such as scanning and transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and Raman Spectroscopy were used for investigation of the morphology and chemical composition of the substrates and thereby studying the etching mechanism. Furthermore, using dynamic-mechanical analysis at temperatures up to 550 °C, the stiffness behavior of the LTCC substrates after wet-chemical etching was investigated, and promising results for the applicability of such modified modules were obtained, even when operated at elevated temperatures up to 550 °C. Finally, a practical correlation between the mechanical properties and the relative porosification depth is presented, which is independent of etching conditions and the substrate thickness, and is valuable for optimization of the suitable depth of porosification for securing the desired mechanical properties. Image 1 • Employing wet chemical etching for porosification of LTCC substrates for local reduction of permittivity. • Detail study on kinetics and mechanism of the etching process. • Tailoring porosification degree and the corresponding depth of porosification by a careful selection of etching parameters. • Achieving high surface quality which allows for a high-quality metal deposition for further applications. • Investigating the stiffness behavior of the substrates over a large temperature range up to 550 °C. [ABSTRACT FROM AUTHOR]

The current limitations in utilizing metal-organic frameworks for (photo)electrochemical applications stem from their diminished electrochemical stability. In our study, we illustrate a method to bolster the activity and stability of (photo)electrocatalytically active metal-organic frameworks through ligand engineering. We synthesize four distinct mixed-ligand versions of zeolitic imidazolate framework-67, and conduct a comprehensive investigation into the structural evolution and self-reconstruction during electrocatalytic oxygen evolution reactions. In contrast to the conventional single-ligand ZIF, where the framework undergoes a complete transformation into CoOOH via a stepwise oxidation, the ligand-engineered zeolitic imidazolate frameworks manage to preserve the fundamental framework structure by in-situ forming a protective cobalt (oxy)hydroxide layer on the surface. This surface reconstruction facilitates both conductivity and catalytic activity by one order of magnitude and considerably enhances the (photo)electrochemical stability. This work highlights the vital role of ligand engineering for designing advanced and stable metal-organic frameworks for photo- and electrocatalysis., (© 2024. The Author(s).)

Background: Evidence-based guideline and vaccination recommendations should continuously be updated to appropriately support health care decisions. However, resources for updating guidelines are often limited. The aim of this project was to develop a list of criteria for the prospective assessment of the need for updating individual guideline or vaccination recommendations, which can be applied from the time a guideline or guideline update is finalised., Methods: In this article we describe the development of the AGIL criteria (Assessment of Guidelines for Updating Recommendations). The AGIL criteria were developed by experienced scientists and experts in the field of guideline development in a multi-step process. The five steps included: 1) development of an initial list of criteria by the project team; 2) online survey of guideline experts on the initial version of the criteria list; 3) revision of the criteria list based on the results of the online survey; 4) workshop on the criteria list at the EbM Congress 2023; 5) creation of version 1.0 of the AGIL criteria based on the workshop results., Results: The initial list included the following three criteria: 1) relevance of the question 2) availability of new relevant evidence, and 3) impact of potentially new evidence. The response rate of the online survey for fully completed questionnaires was 31.0% (N=195; 630 guideline experts were contacted by email). For 90.3% (n=176) of the respondents, the criteria list included all essential aspects for assessing the need for updating guideline recommendations. More than three quarters of respondents rated the importance of the three criteria as "very important" or "important" (criteria 1-3: 75.3%, 86.1%, 85.2%) and - with the exception of criterion 1 - comprehensibility as "very comprehensible" or "comprehensible" (criteria 1-3: 58.4%, 75.9%, 78.5%). The results of the online survey and the workshop generally confirmed the three criteria with their two sub-questions. The incorporation of all feedback resulted in the AGIL criteria (version 1.0), recapping: 1) relevance of the question regarding a) PICO components and b) other factors, e.g. epidemiological aspects; 2) availability of new evidence a) on health-related benefits and harms and b) on other decision factors, e.g. feasibility, acceptability; 3) impact of new evidence a) on the certainty of evidence on which the recommendation is based and b) on the present recommendation, e.g., Discussion: The moderate response rate of the online survey may have limited its representativeness. Nevertheless, we consider the response rate to be satisfactory in this research context. The inclusion of many experts in the online survey and the EbM Congress workshop is a strength of the project and supports the quality of the results., Conclusions: The AGIL criteria provide a structured guidance for the prospective assessment of the need for updating individual guideline recommendations and other evidence-based recommendations. The implementation and evaluation of the AGIL criteria 1.0 in a field test is planned., (Copyright © 2023. Published by Elsevier GmbH.)

As supported CuO is well-known for low temperature activity, CuO/CeO 2 nanosphere catalysts were synthesized and tested for CO oxidation and preferential oxidation of CO (PROX) in excess H 2 . For the first reaction, ignition was observed at 95 °C, whereas selective PROX occurred in a temperature window from 50 to 100 °C. The catalytic performance was independent of the initial oxidation state of the catalyst (CuO vs. Cu 0 ), suggesting that the same active phase is formed under reaction conditions. Density functional modeling was applied to elucidate the intermediate steps of CO oxidation, as well as those of the comparably less feasible H 2 transformation. In the simulations, various Cu and vacancy sites were probed as reactive centers enabling specific pathways., Supplementary Information: The online version contains supplementary material available at 10.1007/s11244-023-01848-x., Competing Interests: Conflict of interestThe authors declare no conflict of interest., (© The Author(s) 2023.)

To elucidate the role of earth alkaline doping in perovskite-based dry reforming of methane (DRM) catalysts, we embarked on a comparative and exemplary study of a Ni-based Sm perovskite with and without Sr doping. While the Sr-doped material appears as a structure-pure Sm 1.5 Sr 0.5 NiO 4 Ruddlesden Popper structure, the undoped material is a NiO/monoclinic Sm 2 O 3 composite. Hydrogen pre-reduction or direct activation in the DRM mixture in all cases yields either active Ni/Sm 2 O 3 or Ni/Sm 2 O 3 /SrCO 3 materials, with albeit different short-term stability and deactivation behavior. The much smaller Ni particle size after hydrogen reduction of Sm 1.5 Sr 0.5 NiO 4 , and of generally all undoped materials stabilizes the short and long-term DRM activity. Carbon dioxide reactivity manifests itself in the direct formation of SrCO 3 in the case of Sm 1.5 Sr 0.5 NiO 4 , which is dominant at high temperatures. For Sm 1.5 Sr 0.5 NiO 4 , the CO : H 2 ratio exceeds 1 at these temperatures, which is attributed to faster direct carbon dioxide conversion to SrCO 3 without catalytic DRM reactivity. As no Sm 2 O 2 CO 3 surface or bulk phase as a result of carbon dioxide activation was observed for any material - in contrast to La 2 O 2 CO 3 - we suggest that oxy-carbonate formation plays only a minor role for DRM reactivity. Rather, we identify surface graphitic carbon as the potentially reactive intermediate. Graphitic carbon has already been shown as a crucial reaction intermediate in metal-oxide DRM catalysts and appears both for Sm 1.5 Sr 0.5 NiO 4 and NiO/monoclinic Sm 2 O 3 after reaction as crystalline structure. It is significantly more pronounced for the latter due to the higher amount of oxygen-deficient monoclinic Sm 2 O 3 facilitating carbon dioxide activation. Despite the often reported beneficial role of earth alkaline dopants in DRM catalysis, we show that the situation is more complex. In our studies, the detrimental role of earth alkaline doping manifests itself in the exclusive formation of the sole stable carbonated species and a general destabilization of the Ni/monoclinic Sm 2 O 3 interface by favoring Ni particle sintering., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The influence of A- and/or B-site doping of Ruddlesden-Popper perovskite materials on the crystal structure, stability, and dry reforming of methane (DRM) reactivity of specific A 2 BO 4 phases (A = La, Ba; B = Cu, Ni) has been evaluated by a combination of catalytic experiments, in situ X-ray diffraction, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and aberration-corrected electron microscopy. At room temperature, B-site doping of La 2 NiO 4 with Cu stabilizes the orthorhombic structure ( Fmmm ) of the perovskite, while A-site doping with Ba yields a tetragonal space group ( I 4/ mmm ). We observed the orthorhombic-to-tetragonal transformation above 170 °C for La 2 Ni 0.9 Cu 0.1 O 4 and La 2 Ni 0.8 Cu 0.2 O 4 , slightly higher than for undoped La 2 NiO 4 . Loss of oxygen in interstitial sites of the tetragonal structure causes further structure transformations for all samples before decomposition in the temperature range of 400 °C-600 °C. Controlled in situ decomposition of the parent or A/B-site doped perovskite structures in a DRM mixture (CH 4 :CO 2 = 1:1) in all cases yields an active phase consisting of exsolved nanocrystalline metallic Ni particles in contact with hexagonal La 2 O 3 and a mixture of (oxy)carbonate phases (hexagonal and monoclinic La 2 O 2 CO 3 , BaCO 3 ). Differences in the catalytic activity evolve because of (i) the in situ formation of Ni-Cu alloy phases (in a composition of >7:1 = Ni:Cu) for La 2 Ni 0.9 Cu 0.1 O 4 , La 2 Ni 0.8 Cu 0.2 O 4 , and La 1.8 Ba 0.2 Ni 0.9 Cu 0.1 O 4 , (ii) the resulting Ni particle size and amount of exsolved Ni, and (iii) the inherently different reactivity of the present (oxy)carbonate species. Based on the onset temperature of catalytic DRM activity, the latter decreases in the order of La 2 Ni 0.9 Cu 0.1 O 4 ∼ La 2 Ni 0.8 Cu 0.2 O 4 ≥ La 1.8 Ba 0.2 Ni 0.9 Cu 0.1 O 4 > La 2 NiO 4 > La 1.8 Ba 0.2 NiO 4 . Simple A-site doped La 1.8 Ba 0.2 NiO 4 is essentially DRM inactive. The Ni particle size can be efficiently influenced by introducing Ba into the A site of the respective Ruddlesden-Popper structures, allowing us to control the Ni particle size between 10 nm and 30 nm both for simple B-site and A-site doped structures. Hence, it is possible to steer both the extent of the metal-oxide-(oxy)carbonate interface and its chemical composition and reactivity. Counteracting the limitation of the larger Ni particle size, the activity can, however, be improved by additional Cu-doping on the B-site, enhancing the carbon reactivity. Exemplified for the La 2 NiO 4 based systems, we show how the delicate antagonistic balance of doping with Cu (rendering the La 2 NiO 4 structure less stable and suppressing coking by efficiently removing surface carbon) and Ba (rendering the La 2 NiO 4 structure more stable and forming unreactive surface or interfacial carbonates) can be used to tailor prospective DRM-active catalysts., Competing Interests: The authors declare no competing financial interest., (© 2020 American Chemical Society.)

Exsolution of metal nanoparticles from perovskite-type oxides is a very promising approach to obtain catalysts with superior properties. One particularly interesting property of exsolution catalysts is the possibility of electrochemical switching between different activity states. In this work, synchrotron-based in-situ X-ray diffraction experiments on electrochemically polarized La 0.6 Sr 0.4 FeO 3-δ thin film electrodes are performed, in order to simultaneously obtain insights into the phase composition and the catalytic activity of the electrode surface. This shows that reversible electrochemical switching between a high and low activity state is accompanied by a phase change of exsolved particles between metallic α--Fe and Fe-oxides. Reintegration of iron into the perovskite lattice is thus not required for obtaining a switchable catalyst, making this process especially interesting for intermediate temperature applications. These measurements also reveal how metallic particles on La 0.6 Sr 0.4 FeO 3-δ electrodes affect the H 2 oxidation and H 2 O splitting mechanism and why the particle size plays a minor role.

Objectives: Patients have to pay out of their own pocket for individual medical services (in German: Individuelle Gesundheitsleistungen, IGeL). The benefit of many IGeL is controversial. Hence, well-founded patient information and counselling are important. For this purpose, several medical organizations and associations developed a checklist including 10 criteria concerning legal and content aspects. Based on this checklist, this study examined how well patients feel informed about IGeL by their doctors. Additionally, we assessed the utilization of IGeL and the attitude of physicians towards IGeL., Methods: A questionnaire was distributed to 1,000 patients in 20 GP practices in Germany. The data of the patient survey was analyzed descriptively., Results: The response rate to the patient survey was 92.9 %. Of 923 patients, 38 % used at least one IGeL in the last 12 months. The most common IGeL were ultrasound examinations (34 %). Differences were found in compliance with the criteria checklist: In most cases, patients received an invoice (79 %), ad-free information (70 %) and explanations of the medical necessity of the IGeL (70 %). However, physicians have failed to meet these criteria in more than a fifth of respondents. Also, physicians rarely refer to other requirements of the checklist such as, for example, further information and the possibility of obtaining a second opinion., Conclusion: This non-representative survey indicates that many patients make use of IGeL. However, they are often not well advised. Physicians should consider criteria of the checklist more rigorously., (Copyright © 2019. Published by Elsevier GmbH.)

Background: As early as 1997, the German Guideline for Guidelines laid down patient participation in guideline development as the cornerstone of good, trustworthy medical guidelines. The German Guideline Assessment Tool (DELBI) published in 2005 requires patients or relatives to be involved in the development of medical guidelines. Ideally, this should be effected through membership in the author group. The Association of the Scientific Medical Societies in Germany (AWMF) recommends this approach for the so-called S3 guidelines (systematically developed guidelines) and S2k guidelines (consensus-based guidelines). The present study addresses the question of whether and to what extent German guideline publishers adhere to these principles of patient orientation., Methods: For this purpose, a descriptive analysis of the guidelines valid at the beginning of November 2017 was carried out. All guidelines (n=520) of the AWMF member societies were assessed. We evaluated S3- and S2k guidelines only, as these are of particular importance for patient involvement due to the requirement of an interdisciplinary guideline group. Data were reported on the involvement of patients (as co-authors of medical guidelines) and on the existence of guidance documents addressing patients and the public (so-called patient information and patient guidelines)., Results: Regarding the 105 (165) S3 (S2k) guidelines, we found evidence on patient involvement in guideline development in 99 (134) cases (94 % of S3 / 81 % of S2k guidelines). In 61 (87) guidelines, authors had contributed to the authors group (58 % / 53 %) and 59 (80) guidelines with voting rights (56 % / 48 %). For 50 (15) S3 (S2k) guidelines (48 % / 9 %), the guideline report provided information on the existence or planned development of guidance documents for patients and the public (patient guidelines or patient information). Guidance-related patient information was available on the internet for only 37 (2) S3 (S2k) guidelines (35 % / 2 %)., Conclusion: A substantial gap remains between patient / public involvement standards for guideline development and practice in Germany, even 12 years after the publication of national guideline standards. This is a missed opportunity since guidelines without adequate participation of those affected by the recommendations have a problem of legitimacy and transparency. Only guidelines where patients were involved in all voting processes during development build and strengthen trust between patients and the medical profession. And only those who present the rationale for medical recommendations in a generally understandable and comprehensible manner let affected individuals make individual decisions., (Copyright © 2018. Published by Elsevier GmbH.)

Purpose: The t(14;18) translocation might represent an intermediate step in the pathogenesis of follicular lymphoma (FL), one of the most common subtypes of non-Hodgkin lymphoma. Circulating t(14;18)-positive cells can also be detected in 30-60 % of healthy individuals at low frequencies. Some studies found a negative association between reproductive factors or use of menopausal hormone therapy (MHT) with FL. The objective of this study was to evaluate whether there is an association between number of frequencies, oral contraceptive (OC) use, menopausal status and MHT, and t(14;18) prevalence and frequency in a representative population analysis based on an epidemiologic study in the northeastern part of Germany., Methods: The analysis is based on results of buffy coat samples from 1,981 women of the Study of Health in Pomerania (SHIP-0) and data obtained in standardized face-to-face interviews. For prevalence, odds ratios (OR) and 95 % confidence intervals (CI) were calculated using unconditional logistic regression. Frequency data were analyzed using negative binomial regression. The multivariable models included age, number of pregnancies, menopausal status (premenopausal, natural, medical/surgical menopause), OC use and MHT as a measure for exogenous hormone exposure use., Results: We found no association between reproductive history and combined exogenous hormone use on the prevalence of circulating t(14;18)-positive cells. Modeling MHT and OC use separately in a sensitivity analysis, the MHT parameter yielded statistical significance [OR 1.37 (95 % CI 1.04;1.81)]. t(14;18) frequency was associated with use of OC [incidence rate ratio (IRR) for ever use 3.18 (95 % CI 1.54;6.54)], current use [IRR 3.86 (1.56;9.54)], >10 years use [IRR 3.93 (1.67;9.23)] and MHT [restricted to postmenopausal women; IRR 2.63 (95 % CI 1.01;6.85)] in bivariate age-adjusted analyses. In the multivariable model, medical/surgical menopause [IRR 2.46 (1.11;5.44)] and the category ever use of OC and MHT were statistically significant [IRR 2.41 (1.09;5.33)]., Conclusions: Exogenous hormone use might be a risk factor for t(14;18) frequency rather than for t(14;18) prevalence. Further research on healthy individuals carrying a t(14;18) translocation and possible risk factors for malignant lymphoma is necessary to determine the additional molecular or immunological events that have to occur to develop FL.

Since 2010, the German Agency for Quality in Medicine has developed so-called short information leaflets for patients that are specifically designed for use in doctor-patient encounters. Physicians, patient representatives and communication specialists were involved in the development of this format. Their implementation aims at enhancing awareness and dissemination of these leaflets amongst the members of the self-governing bodies and other multipliers (like medical specialty societies, patient organisations, other bodies and institutions of the healthcare system). This paper describes the first implementation experiences on the basis of internally collected data on the involvement of multipliers, availability and assessment of their relevance. A first analysis shows that the short information leaflets are broadly available amongst the self-governing bodies and that they are considered to be of high relevance. Due to the direct involvement of the members of specialty societies and patient organisations and other experts, short information leaflets are also gaining acceptance outside the self-governing system. This is emphasised by the rising number of requests to reprint or cite or use the leaflets. Consistency with evidence-based treatment recommendations promotes acceptance of these leaflets among physicians., (Copyright © 2015. Published by Elsevier GmbH.)

The aim of the present study was to investigate the presence of the raccoon roundworm (Baylisascaris [B.] procyonis), a dangerous zoonotic pathogen for humans, in raccoons living in the federal state of Brandenburg, Germany. In the years 2008 to 2013, a total of 762 raccoons, dating from hunting bags, were examined for intestinal helminths. No raccoon roundworm specimen was detected, but 27 samples were positive for Mesocestoides spp. Earlier studies had proved the presence of B. procyonis in Hesse and since 2005 the parasite has also been found in the western part of Saxony-Anhalt. The migration ability of raccoons may promote a further distribution of this parasite and could increase the risk for zoonotic infections in humans.

Background: Conflicts of interest can bias the recommendations of clinical guidelines. In 2010, the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF) revised its rules about how conflicts of interest in guidelines should be managed., Methods: All S2 and S3 guidelines in the AWMF database that were created in the years 2009-2011 were independently examined by two reviewers each (TL, MG, SC, BW, LF, SS). Information on conflicts of interest was extracted and descriptively analyzed. The effects of the new AWMF rules were studied with a before-and-after comparison., Results: 60 (20%) of the 297 guidelines studied contained explicit declarations of conflict of interest by their authors. 680 authors (49%) stated that they had financial relationships that constituted a conflict of interest; 86% declared conflicts arising from membership in specialty societies or professional associations. From 2009 to 2011, there was a substantial rise in the frequency of conflict-of-interest declarations in guidelines (8% of 256 guidelines that were created before the AWMF revised its rules in 2010 and 95% of 41 guidelines created afterward). The percentage of persons declaring financial conflicts of interest rose after the new rules were introduced, while the mode of documentation of conflict-of-interest evaluation and of any measures that might have been taken as a result remained unchanged., Conclusion: From 2011 onward, all conflict-of-interest declarations by guideline authors have been published in the AWMF database. There is no current standard for the evaluation and management of conflicts of interest in guideline-creating groups, and this situation urgently needs to be remedied.

Some invasive wildlife species have the potential to act as additional host and vector species for parasitic and other infectious diseases. We used the raccoon dog (Nyctereutes procyonides), a carnivore species that has its origin in Asia, as an example to demonstrate biological and ecological prerequisites which enables an invasive species to occupy a new habitat permanently. Studies conducted during the last ten years identified a total of 23 endoparasites, two ectoparasites, six bacterial or protozoan species and five viruses, found in the Nyctereutes procyonoides ussuriensis subspecies in its newly occupied range or in N. procyonoides koreensis in its original range. Results of studies in Finland and Germany furthermore showed that biological characteristics of the raccoon dog make this carnivore an appropriate host or vector for a variety of parasites and infectious diseases. This may result in a growing importance of this invasive carnivore for the epidemiology of transmissible diseases in Germany. Especially with regard to zoonotic disease outbreaks, the raccoon dog should therefore be paid more attention in disease prevention and eradication strategies.

Purpose: To determine the association between hormonal contraceptive (HC) use, and behavior-related and biological cardiovascular risk factors among teenage girls in Germany., Methods: HC use was assessed among 2,285 girls aged 13-17 years who participated in the health survey for children and adolescents (German Health Interview and Examination Survey for Children and Adolescents, KiGGS), between years 2003 and 2006. Prevalence of HC use was determined according to sociodemographic variables, behavior-related health risks, and overweight status. We compared HC users and nonusers with respect to biological cardiovascular risk factors, including systolic and diastolic blood pressure, and serum concentrations of lipids, lipoproteins, high sensitivity C-reactive protein (hs-CRP), and homocysteine., Results: HC users were more likely than nonusers to combine several behavior-related health risks, independent of sociodemographic factors. In particular, HC use was strongly associated with current smoking (odds ratio: 3.4, 95% confidence interval: 2.7-4.3). HC use and behavioral factors showed an additive effect on biological cardiovascular risk factors, explaining between 6% and 30% of the population variance. Relative contributions of HC use ranged from <1% for systolic and diastolic blood pressure to 12% for hs-CRP., Conclusions: HC use among 13-17-year-old girls in Germany is significantly correlated with a more unfavorable cardiovascular risk profile, which is partly explained by a clustering of behavioral risk factors among HC users. When prescribing HC to teenagers, physicians should systematically assess avoidable behavioral cardiovascular risk factors and provide counseling tailored to the risk profile of the individual patient., (Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Objectives: Left ventricular hypertrophy (LVH) is a precursor of morbidity and mortality in women. Use of menopausal hormone therapy (MHT) might be associated with decreased left ventricular mass (LVM) and lower risk of LVH, although results of previous observational and clinical studies are inconclusive. Therefore, we analyzed the association between MHT use and either LVM indexed to height(2.7) (LVMI) or LVH determined echocardiographically., Methods: Data from women aged >or=45 years recruited for the population-based Study of Health in Pomerania were used for cross-sectional (n=975) and longitudinal (n=675; 361 women without LVH at baseline) analyses. Information on ever (past and current) and never use of MHT were obtained. Linear (LVMI) or logistic (LVH) regression analyses were performed while controlling for potential confounders., Results: Crude and age-adjusted analyses suggested an association between ever use of MHT and lower odds for LVH. This association was no longer significant in fully adjusted models. Compared to women who never used MHT, the odds ratios of LVH for ever MHT users were 0.97 [95%-confidence interval (95%-CI) 0.71-1.30] in cross-sectional and 0.70 (95%-CI 0.44-1.11) in longitudinal fully adjusted analyses. Similarly, results with an alternative classification of MHT use (never, past, and current) indicated no significant associations with LVH after full adjustment., Conclusions: This study provides little evidence of an association between MHT use and LVH. Differences in lifestyle or health-related factors between never and MHT users could provide an explanation, in part, for the presumptive protective benefit of MHT on LVH., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Online doctor rating sites have been increasingly discussed in the past few years, but scientific papers on the issue are rare. Results of a recent study could show that online doctor rating sites do not support patients in identifying qualified doctors. Against this background, the German Medical Association and the National Association of Statutory Health Insurance Physicians have commissioned the German Agency for Quality in Medicine (ÄZQ) with developing quality standards for online doctor rating sites. The list of quality criteria, published in December 2009, contains 40 questions and defines the following main quality standards: data privacy, transparency in terms of operators and funding, a clear and understandable assessment procedure, a strict separation of content and advertisement, measures against defamation, discrimination and deception. At present,all German online doctor rating sites are being assessed according to the list of quality criteria by ÄZQ. The results will be published., (Copyright © 2010. Published by Elsevier GmbH.)

The carboxy-terminal domain of the transcription factor Escherichia coli NusA, NusACTD, interacts with the protein N of bacteriophage lambda, lambdaN, and the carboxyl terminus of the E. coli RNA polymerase alpha subunit, alphaCTD. We solved the solution structure of the unbound NusACTD with high-resolution nuclear magnetic resonance (NMR). Additionally, we investigated the binding sites of lambdaN and alphaCTD on NusACTD using NMR titrations. The solution structure of NusACTD shows two structurally similar subdomains, NusA(353-416) and NusA(431-490), matching approximately two homologous acidic sequence repeats. Further characterization of NusACTD with 15N NMR relaxation data suggests that the interdomain region is only weakly structured and that the subdomains are not interacting. Both subdomains adopt an (HhH)2 fold. These folds are normally involved in DNA-protein and protein-protein interactions. NMR titration experiments show clear differences of the interactions of these two domains with alphaCTD and lambdaN, in spite of their structural similarity.

Bait disappearance can give valuable information for the assessment of oral vaccination campaigns of foxes against rabies. In this study, the spatial and temporal disappearance of three different vaccine baits under almost identical conditions was investigated. In the study area, 350 baits were placed at previously marked positions during two different periods; late autumn and early spring. The distribution of baits was in accordance with the method as recommended by the European Union; a density of 20 baits per km2 along flight lines 500m apart. Bait disappearance was checked 1, 3, 5 and 7 days after distribution. At least 80% of the baits had disappeared within one week after distribution. No difference in bait disappearance was observed between the two selected periods. However, a significant higher bait disappearance was observed in forested areas when compared to open agricultural areas. Furthermore, the differences in bait disappearance between the three type of baits tested were relatively small and not significant.