Signal Balance as a Pluripotency Determinant: In vitro modeling of in vivo pluripotency states with WNT, FGF and BMP

This thesis enriches the body of knowledge around pluripotency by describing a novel pluripotent state. It deepens our understanding of cell biology, the processes establishing pluripotency and provides new insights into improving the process of artificial generation of pluripotent cells

Characterization of a planar microcoil for implantable microsystems

This paper discusses the modelling, design and characterization of planar microcoils to be used in telemetry systems that supply energy to miniaturized implants. Parasitic electrical effects that may become important at a.c. frequencies of several megahertz are evaluated. The fabrication process and electrical characterization of planar receiver microcoils will be described, and it will be shown that a power of a few milliwatts is feasible.\u

Interpreting random forest models using a feature contribution method

Model interpretation is one of the key aspects of the model evaluation process. The explanation of the relationship between model variables and outputs is easy for statistical models, such as linear regressions, thanks to the availability of model parameters and their statistical significance. For “black box” models, such as random forest, this information is hidden inside the model structure. This work presents an approach for computing feature contributions for random forest classification models. It allows for the determination of the influence of each variable on the model prediction for an individual instance. Interpretation of feature contributions for two UCI benchmark datasets shows the potential of the proposed methodology. The robustness of results is demonstrated through an extensive analysis of feature contributions calculated for a large number of generated random forest models

Switching on electrocatalytic activity in solid oxide cells

Solid oxide cells (SOCs) can operate with high efficiency in two ways - as fuel cells, oxidizing a fuel to produce electricity, and as electrolysis cells, electrolysing water to produce hydrogen and oxygen gases. Ideally, SOCs should perform well, be durable and be inexpensive, but there are often competitive tensions, meaning that, for example, performance is achieved at the expense of durability. SOCs consist of porous electrodes - the fuel and air electrodes - separated by a dense electrolyte. In terms of the electrodes, the greatest challenge is to deliver high, long-lasting electrocatalytic activity while ensuring cost- and time-efficient manufacture. This has typically been achieved through lengthy and intricate ex situ procedures. These often require dedicated precursors and equipment; moreover, although the degradation of such electrodes associated with their reversible operation can be mitigated, they are susceptible to many other forms of degradation. An alternative is to grow appropriate electrode nanoarchitectures under operationally relevant conditions, for example, via redox exsolution. Here we describe the growth of a finely dispersed array of anchored metal nanoparticles on an oxide electrode through electrochemical poling of a SOC at 2 volts for a few seconds. These electrode structures perform well as both fuel cells and electrolysis cells (for example, at 900 °C they deliver 2 watts per square centimetre of power in humidified hydrogen gas, and a current of 2.75 amps per square centimetre at 1.3 volts in 50% water/nitrogen gas). The nanostructures and corresponding electrochemical activity do not degrade in 150 hours of testing. These results not only prove that in operando methods can yield emergent nanomaterials, which in turn deliver exceptional performance, but also offer proof of concept that electrolysis and fuel cells can be unified in a single, high-performance, versatile and easily manufactured device. This opens up the possibility of simple, almost instantaneous production of highly active nanostructures for reinvigorating SOCs during operation

A larger agglutinated foraminifer originally described as a marine plant : the case of Arthrodendron Ulrich, 1904 (Foraminifera), its synonyms and homonyms

The large, agglutinated foraminiferal genus Aschemocella Vialov, 1966 (type species Aschemonella carpathica Neagu, 1964) and the body fossil Halysium Świdziński, 1934 (type species Halysium problematicum Świdziński, 1934) are herein synonymized with the genus Arthrodendron Ulrich, 1904 (type species A. diffusum Ulrich, 1904), a form originally described as a marine alga from Upper Cretaceous (Maastrichtian) flysch sediments of the Kodiak Formation of the Yakutat Group (formerly Yakutat Formation) on Pogibshi Island, Alaska. The species Aschemonella carpathica Neagu is regarded as a subjective junior synonym of Arthrodendron diffusum Ulrich, which is herein lectotypified and transferred to the Foraminifera

The importance of early arthritis in patients with rheumatoid arthritis

Rheumatoid arthritis (RA) is a systemic inflammatory disorder that manifests predominantly in the synovial joint, where it causes a chronic inflammatory process, leading to early osteoarticular destructions. These destructions are progressive and irreversible, generating a significant functional deficiency. During the last years, the diagnostic approach of RA has focused on early arthritis. Early arthritis can develop into established RA or another established arthropathy, like systemic lupus erythematosus or psoriatic arthritis. It can have a spontaneous resolution or may remain undifferentiated for indefinite periods of time. The management of early arthritis has changed considerably in the past few years, under the influence of new concepts of diagnosis and new effective therapies. The treatment goal of early arthritis should now be the clinical remission and prevention of joint destruction. Methotrexate is the first line of therapy, used to treat early arthralgia and to reverse or limit impending exacerbation to RA. Biological treatment is used as a second line therapy in patients with severe disease who do not respond or have a contraindication to disease-modifying antirheumatic drugs (DMARDs). Patients with early arthritis should usually be identified and directed to rheumatologists to confirm the presence of arthritis, and to establish the correct diagnosis plus to initiate the proper treatment strategies

Kinetic Monte Carlo and Cellular Particle Dynamics Simulations of Multicellular Systems

Computer modeling of multicellular systems has been a valuable tool for interpreting and guiding in vitro experiments relevant to embryonic morphogenesis, tumor growth, angiogenesis and, lately, structure formation following the printing of cell aggregates as bioink particles. Computer simulations based on Metropolis Monte Carlo (MMC) algorithms were successful in explaining and predicting the resulting stationary structures (corresponding to the lowest adhesion energy state). Here we present two alternatives to the MMC approach for modeling cellular motion and self-assembly: (1) a kinetic Monte Carlo (KMC), and (2) a cellular particle dynamics (CPD) method. Unlike MMC, both KMC and CPD methods are capable of simulating the dynamics of the cellular system in real time. In the KMC approach a transition rate is associated with possible rearrangements of the cellular system, and the corresponding time evolution is expressed in terms of these rates. In the CPD approach cells are modeled as interacting cellular particles (CPs) and the time evolution of the multicellular system is determined by integrating the equations of motion of all CPs. The KMC and CPD methods are tested and compared by simulating two experimentally well known phenomena: (1) cell-sorting within an aggregate formed by two types of cells with different adhesivities, and (2) fusion of two spherical aggregates of living cells.Comment: 11 pages, 7 figures; submitted to Phys Rev