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The intermetallic compound InPd (CsCl type of crystal structure with a broad compositional range) is considered as a candidate catalyst for the steam reforming of methanol. Single crystals of this phase have been grown to study the structure of its three low-index surfaces under ultra-high vacuum conditions, using low energy electron diffraction (LEED), X-ray photoemission spectroscopy (XPS), and scanning tunneling microscopy (STM). During surface preparation, preferential sputtering leads to a depletion of In within the top few layers for all three surfaces. The near-surface regions remain slightly Pd-rich until annealing to ~580 K. A transition occurs between 580 and 660 K where In segregates towards the surface and the near-surface regions become slightly In-rich above ~660 K. This transition is accompanied by a sharpening of LEED patterns and formation of flat step-terrace morphology, as observed by STM. Several superstructures have been identified for the different surfaces associated with this process. Annealing to higher temperatures (=750 K) leads to faceting via thermal etching as shown for the (110) surface, with a bulk In composition close to the In-rich limit of the existence domain of the cubic phase. The Pd-rich InPd(111) is found to be consistent with a Pd-terminated bulk truncation model as shown by dynamical LEED analysis while, after annealing at higher temperature, the In-rich InPd(111) is consistent with an In-terminated bulk truncation, in agreement with density functional theory (DFT) calculations of the relative surface energies. More complex surface structures are observed for the (100) surface. Additionally, individual grains of a polycrystalline sample are characterized by micro-spot XPS and LEED as well as low-energy electron microscopy. Results from both individual grains and "global" measurements are interpreted based on comparison to our single crystals findings, DFT calculations and previous literature. [ABSTRACT FROM AUTHOR]

A combination of experimental methods was used to study the structure of In thin films deposited on the Pd(111) surface and the alloying behavior. X-ray photoelectron spectroscopy (XPS), lowenergy electron diffraction (LEED), and scanning tunneling microscopy results indicate that surface alloying takes place at room temperature. Below 2 monolayer equivalents (MLEs), the LEED patterns show the formation of three rotational domains of InPd(110) of poor structural quality on top of the Pd(111) substrate. Both core-levels and valence band XPS spectra show that the surface alloy does not yet exhibit the electronic structure characteristic of the 1:1 intermetallic compound under these conditions. Annealing the 1 MLE thin film up to 690 K yields to a transition from a multilayer InPd near-surface intermetallic phase to a monolayer-like surface alloy exhibiting a well ordered (√3 × √3) R30° superstructure and an estimated composition close to In2Pd3. Annealing above 690 K leads to further In depletion and a (1 x 1) pattern is recovered. The (√3 × √3) R30° superstructure is not observed for thicker films. Successive annealing of the 2 MLE thin film leads the progressive disappearance of the InPd diffraction spots till a sharp (1 x 1) pattern is recovered above 690 K. In the high coverage regime (from 4 to 35 MLE), the formation of three rotational domains of a bee-In7Pd3 compound with (110) orientation is observed. This In-rich phase probably grows on top of interfacial InPd(110) domains and is metastable. It transforms into a pure InPd(110) near-surface intermetallic phase in a temperature range between 500 and 600 K depending on the initial coverage. At this stage, the surface alloy exhibits core-level chemical shifts and valence band (VB) spectra identical to those of the 1:1 InPd intermetallic compound and resembling Cu-like density of states. Annealing at higher temperatures yields to a decrease of the In concentration in the near-surface region to about 20 at.% and a (1 x 1) LEED pattern is recovered. [ABSTRACT FROM AUTHOR]

This article attempts to understand better the origin of low friction and zero solid–solid adhesion observed on quasicrystals placed in vacuum. We present an ensemble of experimental data that allows us on the one hand to estimate the true surface energy of unoxidized quasicrystals and approximants and on the other hand to point out a correlation with electronic densities of states. [ABSTRACT FROM AUTHOR]

This paper reports a vacuum or space related effect, which is referred to as “cold welding”, “adhesion” or “sticking”. This effect is studied for bulk quasicrystal (J.M. Dubois, Useful Quasicrystals (World Scientific, Singapore, 2005)) versus different kinds of counterparts (steel, aluminium, titanium, hard metals). Full series of samples, prepared either by crystal-pulling techniques (single crystals) or by sintering (multi-grain samples) were analysed by fretting tests. Four alloy systems were investigated: Al–Pd–Mn, Al–Cr–Fe–B, Al–Cu–B and Al–Cu–Fe–B, with different crystallographic structures and nominal compositions. These materials, especially icosahedral phases, exhibit the absence of cold-welding in vacuum versus certain steels. [ABSTRACT FROM AUTHOR]

Microstructures and morphological features of a series of sintered quasicrystalline Al62.5-xCu25.3Fe12.2Bx alloys, with x ranging from 0 to 5 at.% were studied using x-ray diffraction, scanning electron microscopy, x-ray mapping, and electron probe microanalysis. Electron backscattering diffraction (EBSD) was also used to get information about the structures of some phases and identify the crystalline relationship in-between phases. Increasing x results in the change of the nature of extra phases. These secondary phases are all less than 1% in volume of the total matter except for the β phase at 5% of boron. Whatever the percentage of boron considered, boron seems to concentrate essentially in the parasite phases confirming doubts found in literature about the solubility of boron inside the face-centered-icosahedral Al-Cu-Fe phase. No special crystallographic relationship in between the tested phases could be spotted. EBSD is thus also confirmed as an excellent technique to get quasicrystalline grains orientations. [ABSTRACT FROM AUTHOR]

Investigates posttraumatic stress disorder in survivors of a bus accident who were debriefed and given social and psychological support. Description of research methods utilized; Examination of the Clinician Administered Posttraumatic Stress Disorder scale; Conclusions of this research.

We report the formation of an ordered C60 monolayer on the Al9Co2(001) surface using scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), x-ray and ultraviolet photoelectron spectroscopy (XPS/UPS), and ab initio calculations. Dosing fullerenes at 300 K results in a disordered overlayer. However, the adsorption of C60 with the sample held between 573-673 K leads to a [4, -2ι 1,3] phase. The growth of C60 proceeds with the formation of two domains which are mirror symmetric with respect to the [100] direction. Within each domain, the superstructure unit cell contains six molecules and this implies an area per fullerene equal to 91 Å2 . The molecules exhibit two types of contrast (bright and dim) which are bias dependent. The adsorption energies and preferred molecular configuration at several possible adsorption sites have been determined theoretically. These calculations lead to a possible scheme describing the configuration of each C60 in the observed superstructure. Several defects (vacancies, protrusions,. . . ) and domain boundaries observed in the film are also discussed. If the sample temperature is higher than 693 K when dosing, impinging C60 molecules dissociate at the surface, hence leading to the formation of a carbide film as observed by STM and LEED measurements. The formation of AI4C3 domains and the molecular dissociation are confirmed by XPS/UPS measurements acquired at different stages of the experiment. The cluster substructure present at the Al9Co2(001) surface dictates the carbide domain orientations. [ABSTRACT FROM AUTHOR]

he Al5Co2 crystal is a complex intermetallic compound, whose structure can be described by a stacking of chemically bonded atomic motifs. It is a potentially new catalytic material for heterogeneous hydrogenation. A single crystal of this phase has been grown by the Czochralski technique in order to study the influence of the three-dimensional bulk substructure on the two-dimensional surface using both experimental ultrahigh vacuum surface techniques and ab initio methods based on the density functional theory. Some bulk properties are first presented, focusing on chemical bond strengths, the determination of the Al and Co chemical potentials in Al5Co2, the vibrational properties, and the specific heat. Then, the combination of experimental and computational approaches allows the identification of the surface structure, which was found to depend on the surface preparation conditions. In all cases, the surface terminates at specific bulk layers (Al-rich puckered layers) where various fractions of specific sets of Al atoms are missing, identified as Al3 atoms left at the surface resulting from cluster truncation. Finally, electron density of states calculations and spectroscopic measurements were compared and indicate a strong sp-d hybridization of the topmost pure Al layer with subsurface Co atoms. This could influence the surface reactivity and the catalytic performances of this material. [ABSTRACT FROM AUTHOR]

The growth and stability of Bi thin films on the Al13Co4(100) surface has been investigated from the submonolayer to high-coverage regime by scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) for temperatures ranging from 57 to 633 K. Initially, Bi adsorption leads to the formation of a pseudomorphic monolayer, followed by the growth of islands of different heights with increasing coverage. The in-plane structure, island height, and island morphology indicate that these islands adopt either a pseudocubic (110) or hexagonal (111) orientation normal to the surface. The (HO)-oriented islands correspond to bilayer stacking (either two or four monolayers in height) while the (11 l)-oriented islands correspond to either three- or four-layer stacking. The in-plane orientation of (110) islands with respect to the substrate is random, while (111) islands adopt one of four possible orientations. In addition, the (111) islands show a moire structure. The fact that Bi islands grow with either (110) or (111) orientation simultaneously on the same substrate relates to a subtle energy balance between both orientations according to ab initio calculations, allowing both structures to coexist. The island density dependence versus both deposition temperature and flux, their most frequent structure type, reshaping effects, and chemical reactivity of the different allotropes are also discussed in this paper. [ABSTRACT FROM AUTHOR]

Structural investigations of the (210) and (100) surfaces of Al5Co2 using experimental ultrahigh vacuum techniques and ab initio computational methods are presented in this work. Both surfaces are identified and show bulk terminations where only specific atoms remain. These atoms can be seen as truncated parts of chemically bonded atomic motifs which have been identified in the bulk in a previous work [M. Meier et al., Phys. Rev. B 91, 085414 (2015)]. Whereas the (210) surface presents a single termination, the structure of the (100) topmost layers is found to be highly dependent on the preparation conditions, especially on the annealing temperature. This behavior, also observed for the (001) surface studied previously, can be partly explained when considering the bonding strength of the truncated motif parts with the subsurface. [ABSTRACT FROM AUTHOR]

By investigating the magnetism of spins on a quasiperiodic lattice, we present an experimental study of static and dynamic magnetic properties, specific heat, and magnetic entropy of the Gd3Au13Sn4 quasicrystalline approximant. The magnetic sublattice of Gd3Au13Sn4 is a periodic arrangement of nonoverlapping spin clusters of almost perfect icosahedral symmetry, where gadolinium localized f magnetic moments are distributed on equilateral triangles. The absence of disorder on the magnetic sublattice and the antiferromagnetic (AFM) interactions between the nearest-neighbor spins distributed on triangles result in geometrical frustration of spin-spin interactions. Thus, the Gd3Au13Sn4 phase can be viewed as a prototype site-ordered, geometrically frustrated spin system on icosahedral clusters. The zero-field-cooled and field-cooled magnetic susceptibilities, the alternating current susceptibility, the thermoremanent magnetization, the memory effect, the magnetic specific heat, and the magnetic entropy all show that the spin system undergoes at low temperatures a transition to a nonergodic state at the spin freezing temperature Tf ≈ 2.8 K. Below this, the ergodicity is broken on the experimental timescale, because the thermally activated correlation times for the spin reorientations become macroscopically long. The magnetic state achieved at low temperatures by continuous cooling in low magnetic fields is likely a superposition of (1) metastable states with randomly frozen spins that have no long- range order yet undergo gradual spin-freezing dynamics and (2) an AFM-like magnetically ordered state with critical slowing dynamics. The magnetic properties of the site-ordered, geometrically frustrated Gd3Au13Sn4 system are discussed in comparison to site-disordered spin glasses that contain both randomness and frustration. [ABSTRACT FROM AUTHOR]

A detailed study of the (001) surface of the Al2Cu crystal using both experimental and ab initio computational methods is presented in this work. The combination of both approaches gives many arguments to match the surface plane with a bulk truncated surface model terminated by incomplete Al planes. The missing rows of Al atoms lead to a 2√2 × √2R 45° surface reconstruction with two domains rotated by 90° from each other. Ab initio calculations demonstrate that the energetic cost associated with the removal of pairs of Al atoms is the lowest for the two nearest surface Al atoms (covalentlike interaction). They reveal that the remaining atomic rows of various widths are oriented according to the graphitelike Al 63 nets used to describe the Al2Cu bulk structure. The surface dynamics observed at 300 K at the Al2Cu surface is also presented. Finally, configurational and vibrational entropies are introduced to discuss the reduced surface plane density. [ABSTRACT FROM AUTHOR]

The structure of the quasicrystalline approximant Al13Co4(100) has been determined by surface x-ray diffraction (SXRD) and complementary density-functional-theory (DFT) calculations. Thanks to the use of a two-dimensional pixel detector, which speeds up the data acquisition enormously, an exceptionally large set of experimental data, consisting of 124 crystal truncation rods, has been collected and used to refine this complex structure of large unit cell and low symmetry. Various models were considered for the SXRD analysis. The best fit is consistent with a surface termination at the puckered type of planes but with a depletion of the protruding Co atoms. The surface energy of the determined surface model was calculated using DFT, and it takes a rather low value of 1.09J/m². The results for the atomic relaxation of surface planes found by SXRD or DFT were in excellent agreement. This work opens up additional perspectives for the comprehension of related quasicrystalline surfaces. [ABSTRACT FROM AUTHOR]

By applying the alloy design concept that stable intermetallic phases between two immiscible elements can be formed by adding a third element that forms stable compounds with both elements, we have synthesized the first known stable intermetallic compound of Cu, Gd, and Ca, where copper acts as the mediating element between the immiscible Gd and Ca. A compound with the composition Cu84Gd9Ca7 (equivalent to Cu5Gd0.54Ca0.42) was synthesized by the Czochralski technique in the form of a large single crystal of high structural perfection, and the structural model was determined by x-ray diffraction (XRD). The compound crystallizes in the hexagonal system, space group P6/mmm, and the crystal structure is isotypic to the Cu5.44Tb0.78. The unit cell contains inherent disorder due to partial occupation of the Cu3 site and the substitutional disorder at the Gd/Ca mixed site located at the vertices of the hexagonal unit cell, where Gd and Ca randomly substitute each other. The random substitution of magnetic Gd by nonmagnetic Ca atoms makes the magnetic Gd lattice disordered, which leads to interesting magnetic ordering at low temperatures that occurs below TC=24K in zero and low external magnetic fields. By performing a large set of complementary experiments along two perpendicular crystallographic directions (the [001] hexagonal-axis direction and the [100] hexagonal-plane direction), we show that the zero-field collective magnetic state can be described as a random-anisotropy ferromagnetic state, where random magnetic anisotropies originate from the magnetic dipole interactions between the Gd moments in the magnetically disordered lattice. The random-anisotropy ferromagnetic state in the Cu84Gd9Ca7 is characterized by randomness and frustration of magnetic interactions, which are the two ingredients that allow classifying this state into the generic class of spin glasses. Our paper opens the possibility to search for new ternary intermetallic phases in the Cu-Gd-Ca phase diagram, including structurally complex phases and quasicrystals. [ABSTRACT FROM AUTHOR]

Complex metallic alloys having isolated transition-metal elements in the surface layer have been reported to work well as selective hydrogenation catalysts. We report an experimental determination of the surface structure of one such compound Al13Fe4(010). The structure was determined using low-energy electron diffraction. The best-fit structure terminates in a layer similar to the puckered bulk layer but lacking some of the Al and Fe atoms. Protruding Fe atoms are located in the middle of adjacent pentagonal Al formations, connected to each other by Al "glue" atoms. The top interlayer spacing is compressed relative to the bulk with oscillating relaxations observed for subsequent layers at the surface. [ABSTRACT FROM AUTHOR]

Background: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a condition during pregnancy, which can lead to thrombocytopenia and a bleeding tendency with intracranial hemorrhage (ICH) being the most concerning complication in the fetus or neonate. An incompatibility between human platelet antigen (HPA)-1a accounts for the majority of FNAIT cases. Binding of HPA-1a-specific alloantibodies to their target on fetal platelets and endothelial cells can induce apoptosis of megakaryocytes, disrupt platelet function, and impair angiogenesis. Currently, there is no screening program to identify pregnancies at risk for severe disease. A better understanding of HPA-1a-specific antibody heterogeneity in FNAIT could aid in identifying pathogenic antibody properties linked to severe disease., Study Design and Methods: This study aimed to isolate HPA-1a-specific B-cells from an HPA-1a-alloimmunized pregnant woman. Using fluorescently labeled HPA-1a-positive platelets, single B-cells were sorted and cultured for 10 days to stimulate antibody production. Subsequently, supernatants were tested for the presence of antibodies by enzyme-linked immunosorbent assay and their reactivity towards HPA-1a-positive platelets. Amplification and sequencing of variable regions allowed the generation of monoclonal antibodies using a HEK-Freestyle-based expression system., Results: Three platelet-specific B-cells were obtained and cloned of which two were specific for HPA-1a, named D- and M-204, while the third was specific for HLA class I, which was named L-204., Discussion: This study outlined an effective method for the isolation of HPA-1a-specific B-cells and the generation of monoclonal antibodies. Further characterization of these antibodies holds promise for better understanding the pathogenic nature of alloantibodies in FNAIT., (© 2024 The Authors. Transfusion published by Wiley Periodicals LLC on behalf of AABB.)

Purpose: Three feasible cooling methods for treatment of hyperthermic individuals in the military, that differed considerably in water volume needed (none to ~80 L), were evaluated., Methods: Ten male soldiers were cooled following exercise-induced hyperthermia (rectal temperature (T re ) ∼39.5 °C) using ventilation by fanning (1.7 m s -1 ), ventilation by fanning (1.7 m s -1 ) while wearing a wet t-shirt (250 mL-27 °C water) and tarp assisted cooling with oscillations (80 L of 27.2 ± 0.5 °C water; TACO)., Results: Cooling rates were higher using TACO (0.116 ± 0.032 °C min -1 ) compared to ventilation (0.065 ± 0.011 °C min -1 , P<0.001) and ventilation in combination with a wet t-shirt (0.074 ± 0.020 °C min -1 , P=0.002). Time to cool (TTC) to T re =38.2 °C for TACO was shorter (14 ± 4 min) compared to ventilation only (20 ± 5 min; P=0.018), but not to ventilation while wearing a wet t-shirt (18 ± 6 min; P=0.090)., Conclusions: TACO may be an acceptable, efficient and feasible cooling method in case of exertional heat stroke. However, in case of limited water availability, transportat should be prioritized, and cooling of any form should be implemented while waiting for and during transport., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Neck and shoulder complaints are common in primary care physiotherapy. These patients experience pain and disability, resulting in high societal costs due to, for example, healthcare use and work absence. Content and intensity of physiotherapy care can be matched to a patient's risk of persistent disabling pain. Mode of care delivery can be matched to the patient's suitability for blended care (integrating eHealth with physiotherapy sessions). It is hypothesized that combining these two approaches to stratified care (referred to from this point as Stratified Blended Approach) will improve the effectiveness and cost-effectiveness of physiotherapy for patients with neck and/or shoulder complaints compared to usual physiotherapy., Methods: This paper presents the protocol of a multicenter, pragmatic, two-arm, parallel-group, cluster randomized controlled trial. A total of 92 physiotherapists will be recruited from Dutch primary care physiotherapy practices. Physiotherapy practices will be randomized to the Stratified Blended Approach arm or usual physiotherapy arm by a computer-generated random sequence table using SPSS (1:1 allocation). Number of physiotherapists (1 or > 1) will be used as a stratification variable. A total of 238 adults consulting with neck and/or shoulder complaints will be recruited to the trial by the physiotherapy practices. In the Stratified Blended Approach arm, physiotherapists will match I) the content and intensity of physiotherapy care to the patient's risk of persistent disabling pain, categorized as low, medium or high (using the Keele STarT MSK Tool) and II) the mode of care delivery to the patient's suitability and willingness to receive blended care. The control arm will receive physiotherapy as usual. Neither physiotherapists nor patients in the control arm will be informed about the Stratified Blended Approach arm. The primary outcome is region-specific pain and disability (combined score of Shoulder Pain and Disability Index & Neck Pain and Disability Scale) over 9 months. Effectiveness will be compared using linear mixed models. An economic evaluation will be performed from the societal and healthcare perspective., Discussion: The trial will be the first to provide evidence on the effectiveness and cost-effectiveness of the Stratified Blended Approach compared with usual physiotherapy in patients with neck and/or shoulder complaints., Trial Registration: Netherlands Trial Register: NL8249 . Officially registered since 27 December 2019. Date of first enrollment: 30 September 2020. Study status: ongoing, data collection.

Purpose: The ICF (International Classification of Functioning, Disability and Health) framework (used worldwide to describe 'functioning' and 'disability'), including the ICF scheme (visualization of functioning as result of interaction with health condition and contextual factors), needs reconsideration. The purpose of this article is to discuss alternative ICF schemes., Method: Reconsideration of ICF via literature review and discussions with 23 Dutch ICF experts. Twenty-six experts were invited to rank the three resulting alternative schemes., Results: The literature review provided five themes: 1) societal developments; 2) health and research influences; 3) conceptualization of health; 4) models/frameworks of health and disability; and 5) ICF-criticism (e.g. position of 'health condition' at the top and role of 'contextual factors'). Experts concluded that the ICF scheme gives the impression that the medical perspective is dominant instead of the biopsychosocial perspective. Three alternative ICF schemes were ranked by 16 (62%) experts, resulting in one preferred scheme., Conclusions: There is a need for a new ICF scheme, better reflecting the ICF framework, for further (inter)national consideration. These Dutch schemes should be reviewed on a global scale, to develop a scheme that is more consistent with current and foreseen developments and changing ideas on health. Implications for Rehabilitation We propose policy makers on community, regional and (inter)national level to consider the use of the alternative schemes of the International Classification of Functioning, Disability and Health within their plans to promote functioning and health of their citizens and researchers and teachers to incorporate the alternative schemes into their research and education to emphasize the biopsychosocial paradigm. We propose to set up an international Delphi procedure involving citizens (including patients), experts in healthcare, occupational care, research, education and policy, and planning to get consensus on an alternative scheme of the International Classification of Functioning, Disability and Health. We recommend to discuss the alternatives for the present scheme of the International Classification of Functioning, Disability and Health in the present update and revision process within the World Health Organization as a part of the discussion on the future of the International Classification of Functioning, Disability and Health framework (including ontology, title and relation with the International Classification of Diseases). We recommend to revise the definition of personal factors and to draft a list of personal factors that can be used in policy making, clinical practice, research, and education and to put effort in the revision of the present list of environmental factors to make it more useful in, e.g., occupational health care.

The growth of C60 films on the pseudo-ten-fold (1 0 0) surface of the orthorhombic Al13Co4 quasicrystalline approximant was studied experimentally by scanning tunneling microscopy, low-energy electron diffraction and photoemission spectroscopy. The (1 0 0) surface terminates at bulk-planes presenting local atomic configurations with five-fold symmetry-similar to quasicrystalline surfaces. While the films deposited at room temperature were found disordered, high-temperature growth (up to 693 K) led to quasi-ordered molecular films templated on the substrate rectangular unit mesh. The most probable adsorption sites and geometries were investigated by density functional theory (DFT) calculations. A large range of adsorption energies was determined, influenced by both symmetry and size matching at the molecule-substrate interface. The quasi-ordered structure of the film can be explained by C60 adsorption at the strongest adsorption sites which are too far apart compared to the distance minimizing the intermolecular interactions, resulting in some disorder in the film structure at a local scale. Valence band photoemission indicates a broadening of the molecular orbitals resulting from hybridization between the substrate and overlayer electronic states. Dosing the film at temperature above 693 K led to molecular damage and formation of carbide thin films possessing no azimuthal order with respect to the substrate.