Fingerprinting the magnetic behavior of antiferromagnetic nanostructures using remanent magnetization curves

Antiferromagnetic (AF) nanostructures from Co3O4, CoO and Cr2O3 were prepared by the nanocasting method and were characterized magnetometrically. The field and temperature dependent magnetization data suggests that the nanostructures consist of a core-shell structure. The core behaves as a regular antiferromagnet and the shell as a two-dimensional diluted antiferromagnet in a field (2d DAFF) as previously shown on Co3O4 nanowires [Benitez et al., Phys. Rev. Lett. 101, 097206 (2008)]. Here we present a more general picture on three different material systems, i.e. Co3O4, CoO and Cr2O3. In particular we consider the thermoremanent (TRM) and the isothermoremanent (IRM) magnetization curves as "fingerprints" in order to identify the irreversible magnetization contribution originating from the shells. The TRM/IRM fingerprints are compared to those of superparamagnetic systems, superspin glasses and 3d DAFFs. We demonstrate that TRM/IRM vs. H plots are generally useful fingerprints to identify irreversible magnetization contributions encountered in particular in nanomagnets.Comment: submitted to PR

A novel mutation of KIF11 in a child with 22q11.2 deletion syndrome associated with MCLMR

Microcephaly with or without chorioretinopathy, lymphedema, or mental retardation (MCLMR; OMIM 152950) is a rare autosomal dominantly inherited syndrome. Mutations in the kinesin family member 11 (KIF11) gene have been associated with this condition. Here, we report a de novo novel heterozygous missense mutation in exon 12 of the KIF11 gene [c.1402T>G; p.(Leu468Val)] in a boy with 22q11.2 microdeletion syndrome. His major features were microcephaly, ventricular septal defect, congenital lymphedema of the feet, and distinct facial appearance including upslanting palpebral fissures, a broad nose with rounded tip, anteverted nares, long philtrum with a thin upper lip, pointed chin, and prominent ears. His right eye was enucleated due to subretinal hemorrhage and retinal detachment at age 3 months. Lacunae of chorioretinal atrophy and the pale optic disc were present in the left eye. He also had a de novo 1.6-Mb microdeletion in the Di George/VCFS region of chromosome 22q11.2 in SNP array, which was confirmed by FISH analysis. In this study, for the first time, we describe the co-occurrence of a KIF11 mutation and 22q11.2 deletion syndrome in a patient with MCLMR

Effects of Silica Modification (Mg, Al, Ca, Ti, and Zr) on Supported Cobalt Catalysts for H₂-Dependent CO₂ Reduction to Metabolic Intermediates

Serpentinizing hydrothermal systems generate H2 as a reductant and harbor catalysts conducive to geochemical CO2 conversion into reduced carbon compounds that form the core of microbial autotrophic metabolism. This study characterizes mineral catalysts at hydrothermal vents by investigating the interactions between catalytically active cobalt sites and silica-based support materials on H2-dependent CO2 reduction. Heteroatom incorporated (Mg, Al, Ca, Ti, and Zr), ordered mesoporous silicas are applied as model support systems for the cobalt-based catalysts. It is demonstrated that all catalysts surveyed convert CO2 to methane, methanol, carbon monoxide, and low-molecular-weight hydrocarbons at 180 °C and 20 bar, but with different activity and selectivity depending on the support modification. The additional analysis of the condensed product phase reveals the formation of oxygenates such as formate and acetate, which are key intermediates in the ancient acetyl-coenzyme A pathway of carbon metabolism. The Ti-incorporated catalyst yielded the highest concentrations of formate (3.6 mM) and acetate (1.2 mM) in the liquid phase. Chemisorption experiments including H2 temperature-programmed reduction (TPR) and CO2 temperature-programmed desorption (TPD) in agreement with density functional theory (DFT) calculations of the adsorption energy of CO2 suggest metallic cobalt as the preferential adsorption site for CO2 compared to hardly reducible cobalt–metal oxide interface species. The ratios of the respective cobalt species vary depending on the interaction strength with the support materials. The findings reveal robust and biologically relevant catalytic activities of silica-based transition metal minerals in H2-rich CO2 fixation, in line with the idea that autotrophic metabolism emerged at hydrothermal vents

Advancing Critical Chemical Processes for a Sustainable Future: Challenges for Industry and the Max Planck–Cardiff Centre on the Fundamentals of Heterogeneous Catalysis (FUNCAT)

Catalysis is involved in around 85 % of manufacturing industry and contributes an estimated 25 % to the global domestic product, with the majority of the processes relying on heterogeneous catalysis. Despite the importance in different global segments, the fundamental understanding of heterogeneously catalysed processes lags substantially behind that achieved in other fields. The newly established Max Planck–Cardiff Centre on the Fundamentals of Heterogeneous Catalysis (FUNCAT) targets innovative concepts that could contribute to the scientific developments needed in the research field to achieve net zero greenhouse gas emissions in the chemical industries. This Viewpoint Article presents some of our research activities and visions on the current and future challenges of heterogeneous catalysis regarding green industry and the circular economy by focusing explicitly on critical processes. Namely, hydrogen production, ammonia synthesis, and carbon dioxide reduction, along with new aspects of acetylene chemistry

Neotectonics of the South Marmara Sub-Region

Neotektonik dönemde Kuzey Anadolu Fayı ve kolları, inceleme alanı ve Marmara Bölgesi’nde en etkin tektonik yapıyı oluşturmaktadırlar. KAF, Marmara Bölgesi’nde kuzey ve güney olmak üzere iki kola ayrılır. Bunlardan Marmara Denizi’nin kuzeyinden geçen kol kuzey kol, güneyinden ve inceleme alanından geçen kol ise güney koldur. İnceleme alanında kuzeyde Edincik, Kapıdağı, Bandırma-Mudanya yükselimleri, güneyde Uludağ yükselimi ve Söğütalan platosu yer alır. Bu iki yükselim alanının ortasında doğu-batı uzanımlı bir çöküntü (depresyon) alanı gelişmiştir. Bu yükselim alanları ve çöküntü alanı, neotektonik dönemde Kuzey Anadolu Fayı’nın güney kolunun etkinliği ve kontrolü ile meydana gelmişlerdir. Çöküntü alanı içerisinde ise bir çok çek-ayır biçiminde havzalar oluşmuştur. Bölgede KAF’ın güney koluna ait faylar Yenice-Gönen, Manyas-Mustafakemalpaşa, Uluabat ve Bursa faylarıdır. Sismolojik veriler bölgedeki depremlerin  büyük ölçüde KAF’a ait güney kol üzerinde meydana geldiğini, hasar yapıcı ve yıkıcı depremlerin  hem doğrultu atımlı hem de eğim atımlı faylar üzerinde oluştuğunu göstermektedir.Anahtar Kelimeler: Güney Marmara Bölgesi, Kuzey Anadolu Fayı, çek-ayır havza, yanal atımlı fay.  In neotectonic period, North Anatolian Fault and its branches are the most active in the study area and Marmara Region. NAF is divided into two bracnhes as north and south  in the Marmara Region. The northern branch is located in the north of the Sea of Marmara. The southern branch is located in study area and south of the Sea of Marmara. The South Marmara Region has ptwo uplift areas located at southern and northern margins and a depression between these uplifts. The north uplifts are Edincik, Kapıdağı and Bandırma-Mudanya, south uplifts are Uludağ uplift and Söğütalan Plateau. The uplift and depression areas are contrelled by the southern branch of the NAF in the neotectonic period. In the depression area a lot of pull-apart style basins happened. The southern branch of the North Anatolian Fault, which consists of the Yenice-Gönen, Manyas-M.Kemalpaşa, Uluabat and Bursa faults. According to seismological data of  South Marmara Region, earthquakes have occured on the southern branch of the NAF and earthquakes show that the faults have not only strike-slip but also normal fault characteristics.Keywords: South Marmara Region, North Anatolian Fault, pull-apart basin, strike-slip faul

Tunable e_g Orbital Occupancy in Heusler Compounds for Oxygen Evolution Reaction

Heusler compounds have potential in electrocatalysis because of their mechanical robustness, metallic conductivity, and wide tunability in the electronic structure and element compositions. This study reports the first application of Co2YZ-type Heusler compounds as electrocatalysts for the oxygen evolution reaction (OER). A range of Co2YZ crystals was synthesized through the arc-melting method and the eg orbital filling of Co was precisely regulated by varying Y and Z sites of the compound. A correlation between the eg orbital filling of reactive Co sites and OER activity was found for Co2MnZ compounds (Z=Ti, Al, V, and Ga), whereby higher catalytic current was achieved for eg orbital filling approaching unity. A similar trend of eg orbital filling on the reactivity of cobalt sites was also observed for other Heusler compounds (Co2VZ, Z=Sn and Ga). This work demonstrates proof of concept in the application of Heusler compounds as a new class of OER electrocatalysts, and the influence of the manipulation of the spin orbitals on their catalytic performance. © 2020 The Authors. Angewandte Chemie International Edition published by Wiley-VCH Gmb

DOCK6 Mutations Are Responsible for a Distinct Autosomal-Recessive Variant of Adams-Oliver Syndrome Associated with Brain and Eye Anomalies

Author contacted for file

Advancing critical chemical processes for a sustainable future: challenges for industry and the Max Planck-Cardiff centre on the fundamentals of heterogeneous catalysis (funcat)

Catalysis is involved in around 85 % of manufacturing industry and contributes an estimated 25 % to the global domestic product, with the majority of the processes relying on heterogeneous catalysis. Despite the importance in different global segments, the fundamental understanding of heterogeneously catalysed processes lags substantially behind that achieved in other fields. The newly established Max Planck–Cardiff Centre on the Fundamentals of Heterogeneous Catalysis (FUNCAT) targets innovative concepts that could contribute to the scientific developments needed in the research field to achieve net zero greenhouse gas emissions in the chemical industries. This Viewpoint Article presents some of our research activities and visions on the current and future challenges of heterogeneous catalysis regarding green industry and the circular economy by focusing explicitly on critical processes. Namely, hydrogen production, ammonia synthesis, and carbon dioxide reduction, along with new aspects of acetylene chemistry

Lipid-mediated Wnt protein stabilization enables serum-free culture of human organ stem cells

Wnt signalling proteins are essential for culture of human organ stem cells in organoids, but most Wnt protein formulations are poorly active in serum-free media. Here we show that purified Wnt3a protein is ineffective because it rapidly loses activity in culture media due to its hydrophobic nature, and its solubilization requires a detergent, CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), that interferes with stem cell self-renewal. By stabilizing the Wnt3a protein using phospholipids and cholesterol as carriers, we address both problems: Wnt activity remains stable in serum-free media, while non-toxic carriers allow the use of high Wnt concentrations. Stabilized Wnt3a supports strongly increased self-renewal of organ and embryonic stem cells and the serum-free establishment of human organoids from healthy and diseased intestine and liver. Moreover, the lipophilicity of Wnt3a protein greatly facilitates its purification. Our findings remove a major obstacle impeding clinical applications of adult stem cells and offer advantages for all cell culture uses of Wnt3a protein

A hydrogen-dependent geochemical analogue of primordial carbon and energy metabolism

Hydrogen gas, H2, is generated by alkaline hydrothermal vents through an ancient geochemical process called serpentinization in which water reacts with iron containing minerals deep within the Earth's crust. H2 is the electron donor for the most ancient and the only energy releasing route of biological CO2 fixation, the acetyl-CoA pathway. At the origin of metabolism, CO2 fixation by hydrothermal H2 within serpentinizing systems could have preceded and patterned biotic pathways. Here we show that three hydrothermal minerals—greigite (Fe3S4), magnetite (Fe3O4) and awaruite (Ni3Fe)—catalyse the fixation of CO2 with H2 at 100°C under alkaline aqueous conditions. The product spectrum includes formate (up to 200 mM), acetate (up to 100 µM), pyruvate (up to 10 µM), methanol (up to 100 µM), and methane. The results shed light on both the geochemical origin of microbial metabolism and on the nature of abiotic formate and methane synthesis in modern hydrothermal vents