Halogenated Cobalt Bis-Dicarbollide Strong Acids as Reusable Homogeneous Catalysts for Fatty Acid Esterification with Methanol or Ethanol.

The most commonly used homogeneous catalyst for fatty acid esterification is a corrosive sulphuric acid. However, this requires costly investment in non-corrosive equipment, presents a safety risk, is time consuming, and increases effluent generation. In this study, inorganic 3D heteroborane cluster strong acids are employed for the first time as homogeneous catalysts.

Multicolor photoluminescence of Cu clusters modulated using surface ligands.

Copper nanoclusters exhibit unique structural features and their molecular assembly results in diverse photoluminescence properties. In this study, we present ligand-dependent multicolor luminescence observed in a Cu cluster, primarily protected by -carborane-9,12-dithiol (-CBDT), featuring an octahedral Cu inner kernel enveloped by eight isolated copper atoms. The outer layer of the metal kernel consists of six bidentate -CBDT ligands, in which carborane backbones are connected through μ-sulphide linkages.

Citrate-Buffered, Magnesium-Enriched Dialysate on Calcification Propensity in Hemodialysis Patients - The CitMag Study.

Introduction: Serum calcification propensity (T50 time) is associated with mortality in patients on dialysis. Several solitary interventions improve T50. However, whether a combination of interventions yields further increases in T50 is unknown.

Macropolyhedral -BH, the "Forgotten" Isomer.

The chemistry and physics of macropolyhedral BH clusters have attracted significant attention due to the interesting photophysical properties of -BH (blue emission, laser properties) and related potential applications. We have focused our attention on the "forgotten" -BH isomer, which has received very little attention since its discovery compared to its -BH isomer, presumably because numerous studies have reported this isomer as nonluminescent. In our study, we show that in crystalline form, -BH exhibits blue fluorescence and becomes phosphorescent when substituted at various positions on the cluster, associated with peculiar microstructural-dependent effects.

Case Study of Additively Manufactured Mountain Bike Stem.

This article is focused on a case study of the topology optimisation of a bike stem manufactured by selective laser melting (SLM) additive technology. Topology optimisation was used as a design tool to model a part with less material used for transferring specific loads than the conventional method. For topology optimisation, Siemens NX 12 software was used with loads defined from the ISO 4210-5 standard.

Laser Powder Bed Fusion of Molybdenum and Mo-0.1SiC Studied by Positron Annihilation Lifetime Spectroscopy and Electron Backscatter Diffraction Methods.

Positron annihilation lifetime spectroscopy (PALS) has been used for the first time to investigate the microstructure of additively manufactured molybdenum. Despite the wide applicability of positron annihilation spectroscopy techniques to the defect analysis of metals, they have only been used sparingly to monitor the microstructural evolution of additively manufactured metals. Molybdenum and molybdenum with a dilute addition (0.

Carborane-thiol protected copper nanoclusters: stimuli-responsive materials with tunable phosphorescence.

Atomically precise nanomaterials with tunable solid-state luminescence attract global interest. In this work, we present a new class of thermally stable isostructural tetranuclear copper nanoclusters (NCs), shortly Cu@oCBT, Cu@mCBT and Cu@ICBT, protected by nearly isomeric carborane thiols: -carborane-9-thiol, -carborane-9-thiol and -carborane 12-iodo 9-thiol, respectively. They have a square planar Cu core and a butterfly-shaped CuS staple, which is appended with four respective carboranes.

Platelet function and soluble P-selectin in patients with primary immune thrombocytopenia.

Background: The bleeding phenotype in immune thrombocytopenia (ITP) is heterogeneous, but usually mild and only partly dependent on the severity of thrombocytopenia. Platelet reactivity has previously been suggested to underly the mild phenotype.

Methods: Platelet function was assessed as basal and agonist-induced surface expression of P-selectin and activation of GPIIb/IIIa via flow cytometry, and soluble (s)P-selectin levels were assessed in plasma of 77 patients with primary ITP, 19 hemato-oncologic thrombocytopenic controls (TC) and 20 healthy controls (HC).

The Livelihood of Artisanal and Small-Scale Miners and Awareness of the Use of 3T Minerals in Rwanda-A Case Study in the Rutsiro District: A Qualitative Assessment.

This article examines the impact of artisanal and small-scale mining (ASM) on livelihood in mining communities in Rwanda (Rutsiro) where wolframite and coltan are mined. The paper discusses the development of ASM and other entrepreneur activities, in particular agriculture. With ASM activities, there is environmental degradation on the one hand but also an improvement in the well-being of the local population on the other.

Carboranethiol-Protected Propeller-Shaped Photoresponsive Silver Nanomolecule.

We report the synthesis, structural characterization, and photophysical properties of a propeller-shaped Ag nanomolecule with six rotary arms, protected with -carborane-9-thiol (MCT) and triphenylphosphine (TPP) ligands. Structural analysis reveals that the nanomolecule has an Ag central icosahedral core with six directly connected silver atoms and two more silver atoms connected through three Ag-S-Ag bridging motifs. While 12 MCT ligands protect the core through metal-thiolate bonds in a 3-6-3-layered fashion, two TPP ligands solely protect the two bridging silver atoms.

Alumina Manufactured by Fused Filament Fabrication: A Comprehensive Study of Mechanical Properties and Porosity.

This article deals with a comprehensive study of the processing and mechanical properties of the ceramic material Al2O3 on Fused Filament Fabrication technology (FFF). It describes the basic input analyses of the material, such as TGA, FTIR, and MVR. These analyses enabled the design and testing of process parameters for the 3D printing of parts.

Light-Activated Intercluster Conversion of an Atomically Precise Silver Nanocluster.

Noble metal nanoclusters protected with carboranes, a 12-vertex, nearly icosahedral boron-carbon framework system, have received immense attention due to their different physicochemical properties. We have synthesized -carborane-1,2-dithiol (CBDT) and triphenylphosphine (TPP) coprotected [Ag(CBDT)(TPP)] (shortly Ag) using a ligand-exchange induced structural transformation reaction starting from [AgH(TPP)] (shortly Ag). The formation of Ag was confirmed using UV-vis absorption spectroscopy, mass spectrometry, transmission electron microscopy, X-ray photoelectron spectroscopy, infrared spectroscopy, and multinuclear magnetic resonance spectroscopy.

Lewis Superacidic Tellurenyl Cation-Induced Electrophilic Activation of an Inert Carborane.

The aryltellurenyl cation [2-(tBuNCH)C H Te] , a Lewis super acid, and the weakly coordinating carborane anion [CB H ] , an extremely weak Brønsted acid (pK =131.0 in MeCN), form an isolable ion pair complex [2-(tBuNCH)C H Te][CB H ], in which the Brønsted acidity (pK 7.4 in MeCN) of the formally hydridic B-H bonds is dramatically increased by more than 120 orders of magnitude.

Mechanical Properties of Polypropylene: Additive Manufacturing by Multi Jet Fusion Technology.

Multi jet fusion (MJF) technology has proven its significance in recent years as this technology has continually increased its market share. Recently, polypropylene (PP) was introduced by Hewlett-Packard for the given technology. To our knowledge, little is known about the mechanical properties of polypropylene processed by MJF technology.

Navigational Needs and Preferences of Hospital Patients and Visitors: What Prospects for Smart Technologies?

In this paper, we map navigational needs and preferences of patients and visitors to evaluate the appropriateness of a smartphone navigation application in the hospital in contrast to other, more traditional navigational cues. We test the effects of sociodemographic variables (age, gender, education) on wayfinding strategies and preferences of respondents (using chi2 tests). Empirical research is based on the survey among 928 patients/visitors of the Vítkovice Hospital in Ostrava, Czechia.

Epidemiological insights from a large-scale investigation of intestinal helminths in Medieval Europe.

Helminth infections are among the World Health Organization's top neglected diseases with significant impact in many Less Economically Developed Countries. Despite no longer being endemic in Europe, the widespread presence of helminth eggs in archaeological deposits indicates that helminths represented a considerable burden in past European populations. Prevalence of infection is a key epidemiological feature that would influence the elimination of endemic intestinal helminths, for example, low prevalence rates may have made it easier to eliminate these infections in Europe without the use of modern anthelminthic drugs.

A pulsed positronium beam using a positron buffer gas trap.

We describe the operation of a pulsed positronium beam based on a two-stage buffer gas positron trap (BGT) or a Surko trap. The BGT allows the areal density and temporal spread of the positron beam to be tailored. This tailored positron beam is used to form a positronium beam via charge exchange with an atomic or molecular gas.

A theoretical analysis of the structure and properties of BH isomers. Consequences to the laser and semiconductor doping capabilities of large borane clusters.

Decaborane(14), nido-BH, is the major commercially available molecular building block in boron cluster chemistry. The condensation of two such {nido-B} blocks gives the known isomers of BH- a molecule used in the fabrication of p-type semiconductors and capable of blue laser emission. Here, we computationally determine the structures and thermodynamic stabilities of 20 possible BH regioisomers constructed from the fusion of three {nido-B} blocks with the three subclusters conjoined by two-boron atom shared edges.

Radiation tolerance of two-dimensional material-based devices for space applications.

Characteristic for devices based on two-dimensional materials are their low size, weight and power requirements. This makes them advantageous for use in space instrumentation, including photovoltaics, batteries, electronics, sensors and light sources for long-distance quantum communication. Here we present a comprehensive study on combined radiation effects in Earth's atmosphere on various devices based on these nanomaterials.

Positron scattering from pyridine.

We present a range of cross section measurements for the low-energy scattering of positrons from pyridine, for incident positron energies of less than 20 eV, as well as the independent atom model with the screening corrected additivity rule including interference effects calculation, of positron scattering from pyridine, with dipole rotational excitations accounted for using the Born approximation. Comparisons are made between the experimental measurements and theoretical calculations. For the positronium formation cross section, we also compare with results from a recent empirical model.

Near-Threshold Ionization of Argon by Positron Impact.

The direct single-ionization cross section for Ar by positron impact has been measured in the region above the first ionization threshold. These measurements are compared to semiclassical calculations which give rise to a power law variation of the cross section in the threshold region. The experimental results appear to be in disagreement with extensions to the Wannier theory applied to positron impact ionization, with a smaller exponent than that calculated by most previous works.

Acid-Base Control of Valency within Carboranedithiol Self-Assembled Monolayers: Molecules Do the Can-Can.

We use simple acid-base chemistry to control the valency in self-assembled monolayers of two different carboranedithiol isomers on Au{111}. Monolayer formation proceeds via Au-S bonding, where manipulation of pH prior to or during deposition enables the assembly of dithiolate species, monothiol/monothiolate species, or combination. Scanning tunneling microscopy (STM) images identify two distinct binding modes in each unmodified monolayer, where simultaneous spectroscopic imaging confirms different dipole offsets for each binding mode.

Nuclear Magnetic Shielding of Monoboranes: Calculation and Assessment of B NMR Chemical Shifts in Planar BX and in Tetrahedral [BX] Systems.

B NMR chemical shifts of tricoordinated BX and tetracoordinated BX compounds (X = H, CH, F, Cl, Br, I, OH, SH, NH, and CH═CH) were computed, and the shielding tensors were explored not only within the nonrelativistic GIAO approach but also by application of both relativistic ZORA computations including spin-orbit coupling as well as scalar nonrelativistic ZORA computations (BP86 level of density functional theory). The contributions of the spin-orbit coupling to the overall shieldings are decisive for X = Br and I in both series. No relationship was found between the 2p orbital occupancies or 1/ΔE (difference between LUMO and suitably occupied MO that can be coupled with LUMO) with the shielding tensors (or their principal values) in the BX series.

Impact of Elimination or Reduction of Dietary Animal Proteins on Cancer Progression and Survival: Protocol of an Online Pilot Cohort Study.

Background: Current evidence suggests that the incidence of cancer is low in vegan populations, and experimental studies have revealed a significant role of dietary proteins in cancer development and progression. However, little data currently exists regarding the effect of a plant-based diet on the progression of diagnosed cancer.

Objective: The main objective of this study is to determine if a reduction or total elimination of animal protein from the diet can positively influence the outcome of an existing cancer and, in addition to standard oncological therapies, increase remission rates.

Population-specific stature estimation from long bones in the early medieval Pohansko (Czech Republic).

Objectives: We tested the effect of population-specific linear body proportions on stature estimation.

Materials And Methods: We used a skeletal sample of 31 males and 20 females from the Early Medieval site at Pohansko (Břeclav, Central Europe) and a comparative Central European Early Medieval sample of 45 males and 28 females. We developed new population-specific equations for the Pohansko sample using anatomical reconstructions of stature, then compared percentage prediction errors (%PEs) of anatomical stature from limb bone lengths using the derived Pohansko equations with those previously derived from more general European and other Early Medieval samples.