Ion-doped brushite cements for bone regeneration

Decades of research in orthopaedics has culminated in the quest for formidable yet resorbable biomaterials using bioactive materials. Brushite cements most salient features embrace high biocompatibility, bioresorbability, osteoconductivity, self-setting characteristics, handling, and injectability properties. Such type of materials is also effectively applied as drug delivery systems. However, brushite cements possess limited mechanical strength and fast setting times. By means of incorporating bioactive ions, which are incredibly promising in directing cell fate when incorporated within biomaterials, it can yield biomaterials with superior mechanical properties. Therefore, it is a key to develop fine-tuned regenerative medicine therapeutics. A comprehensive overview of the current accomplishments of ion-doped brushite cements for bone tissue repair and regeneration is provided herein. The role of ionic substitution on the cements physicochemical properties, such as structural, setting time, hydration products, injectability, mechanical behaviour and ion release is discussed. Cell-material interactions, osteogenesis, angiogenesis, and antibacterial activity of the ion-doped cements, as well as its potential use as drug delivery carriers are also presented.This study was funded by the Portuguese Foundation for Science and Technology (FCT) and the German Academic Exchange Service (Deutscher Akademischer Austauschdienst, DAAD) for the transnational cooperation FCT/DAAD 2018-2019. The authors also thank the funds provided under the distinctions attributed to JMO (IF/01285/2015) and SP (CEECIND/03673/2017). Furthermore, funding by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG), Grant Nr. HU 2498/1-1; GB 1/22-1, and the Emerging Talents Initiative of the FAU is acknowledged

Исследование изотопной селективности процесса кристаллизации NaCl из водного раствора, находящегося в магнитном поле

Объектом исследования являются кристаллы NaCl, выращенные под воздействием постоянного магнитного поля из водного раствора. В данной работе приведены теоретическое обоснование и результаты исследований по изменению изотопного эффекта в постоянном магнитном поле при кристаллизации NaCl из водных растворов.The object of study are NaCl crystals grown under the influence of a constant magnetic field from an aqueous solution. This paper presents the theoretical justification and research results on the change in the isotope effect in a constant magnetic field during crystallization of NaCl from aqueous solutions

Accelerated swell testing of artificial sulfate bearing lime stabilised cohesive soils

This paper reports on the physico-chemical response of two lime stabilised sulfate bearing artificial soils subject to the European Accelerated Volumetric Swell Test (EN13286-49). At various intervals during the test, a specimen was removed and subject to compositional and microstructural analysis. Ettringite was formed by both soils types, but with significant differences in crystal morphology. Ettringite crystals formed from kaolin based soils were very small, colloidal in size and tended to form on the surface of other particles. Conversely, those formed from montmorillonite were relatively large and typically formed away from the surface in the pore solution. It was concluded that the mechanism by which ettringite forms is determined by the hydroxide ion concentration in the pore solution and the fundamental structure of the bulk clay. In the kaolin soil, ettringite forms by a topochemical mechanism and expands by crystal swelling. In the montmorillonite soil, it forms by a through-solution mechanism and crystal growth

Enthalpy of formation of ye’elimite and ternesite

Calcium sulfoaluminate clinkers containing ye’elimite (Ca4Al6O12(SO4)) and ternesite (Ca5(SiO4)2SO4) are being widely investigated as components of calcium sulfoaluminate cement clinkers. These may become low energy replacements for Portland cement. Conditional thermodynamic data for ye’elimite and ternesite (enthalpy of formation) have been determined experimentally using a combination of techniques: isothermal conduction calorimetry, X-ray powder diffraction and thermogravimetric analysis. The enthalpies of formation of ye’elimite and ternesite at 25 °C were determined to be − 8523 and − 5993 kJ mol−1, respectively

Observing many researchers using the same data and hypothesis reveals a hidden universe of uncertainty

This study explores how researchers’ analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers’ expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team’s workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers’ results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings

Cognitive biases in expectation formation: Lab evidence on redistribution preferences, financial forecasting, and subscription traps

Upon an introductory part, Chapter 2 brings existing inequality in South Africa (high) and Switzerland (low) to the lab to study how people’s preferences for redistribution change with the level of income inequality and uncertainty of income positions. The results propose an inequality trap: greater inequality today favors personal income overestimation. Demand for redistribution reduces, which propels advanced inequality tomorrow. Chapter 3 reports a series of Learning-to-Forecast experiments, which are found to replicate price volatility of demand-driven asset markets quite accurately. This study investigates whether “bubble-and-crash” dynamics persist in the long run (150 periods) and how decision time (6 vs. 25 sec) influences market volatility. Low time pressure induces a tendency of prices converging to their fundamental value in the long run. In contrast, increasing time pressure limits trend-chasing behavior and coordination right from the beginning. Consequently, there is less price volatility and faster convergence to the fundamental value. Chapter 4 explores a novel menu effect in the context of subscriptions. Providers typically capitalize on arranging offers such that a longer, but costlier option is chosen over the cheaper, but shorter alternative. Sizing the shorter subscription down to single-use raises its attraction. This suspects that the presence of a single-use option prompts rational evaluation based on a realistic estimate to use the subscription again. Instead, when both alternatives represent time spans, an irrational mind may discern them along the same category - referred to as pigeonholing - with the consequence that other comparative criteria come to the fore