Cholangiocytes: Cell transplantation

Background:Due to significant limitations to the access to orthotropic liver transplantation, cell therapies forliver diseases have gained large interest worldwide.Scope of review:To revise current literature dealing with cell therapy for liver diseases. We discussed the ad-vantages and pitfalls of the different cell sources tested so far in clinical trials and the rationale underlying thepotential benefits of transplantation of human biliary tree stem cells (hBTSCs).Major conclusions:Transplantation of adult hepatocytes showed transient benefits but requires immune-sup-pression that is a major pitfall in patients with advanced liver diseases. Mesenchymal stem cells and hemato-poietic stem cells transplanted into patients with liver diseases are not able to replace resident hepatocytes butrather they target autoimmune or inflammatory processes into the liver. Stem cells isolated from fetal or adultliver have been recently proposed as alternative cell sources for advanced liver cirrhosis and metabolic liverdisease. We demonstrated the presence of multipotent cells expressing a variety of endodermal stem cell markersin (peri)-biliary glands of bile ducts in fetal or adult human tissues, and in crypts of gallbladder epithelium. Inthefirst cirrhotic patients treated in our center with biliary tree stem cell therapy, we registered no adverse eventbut significant benefits.General significance:The biliary tree stem cell could represent the ideal cell source for the cell therapy of liverdiseases. This article is part of a Special Issue entitled: Cholangiocytes in Health and Diseaseedited by JesusBanales, Marco Marzioni, Nicholas LaRusso and Peter Jansen

Estudio analítico de un modelo predador-presa con efecto Allee

El efecto Allee se introduce en modelos de competencia intraespecífica y dos especies en competencia. Se utiliza análisis de plano de fase y simulación para investigar la dinámica de estos modelos. Combinando modelación simple y simulación, se demuestra que el efecto Allee por sí solo podría llevar sistemas de dos especies en competencia a estados estables alternativos. En tales sistemas, si la competencia interespecífica es intensa, las dos especies podrían extinguirse aunque su densidad de población sea alta

Stochastic Electron Acceleration by Temperature Anisotropy Instabilities Under Solar Flare Plasma Conditions

We use 2D particle-in-cell (PIC) plasma simulations to study electron acceleration by electron temperature anisotropy instabilities, assuming magnetic fields ($B$), electron densities ($n_e$) and temperatures ($T_e$) typical of the top of contracting magnetic loops in solar flares. We focus on the long-term effect of $T_{e,\perp} > T_{e,\parallel}$ instabilities by driving the anisotropy growth during the whole simulation time ($T_{e,\perp}$ and $T_{e,\parallel}$ are the temperatures perpendicular and parallel to the field). This is achieved by imposing a shear velocity, which amplifies the field due to magnetic flux freezing, making $T_{e,\perp} > T_{e,\parallel}$ due to electron magnetic moment conservation. We use the initial conditions: $T_e \sim 52$ MK, and $B$ and $n_e$ such that the ratio between the electron cyclotron and plasma frequencies $\omega_{ce}/\omega_{pe}=0.53$. When the anisotropy becomes large enough, oblique, quasi-electrostatic (OQES) modes grow, efficiently scattering the electrons and limiting their anisotropy. After that, when $B$ has grown by a factor $\sim 2-3$ (corresponding to $\omega_{ce}/\omega_{pe}\sim 1.2-1.5$), the unstable modes become dominated by parallel, electromagnetic z (PEMZ) modes. In contrast to the OQES dominated regime, the scattering by PEMZ modes is highly inelastic, producing significant electron acceleration. When the field has grown by a final factor $\sim 4$, the electron energy spectrum shows a nonthermal tail that resembles a power-law of index $\sim$ 2.9, plus a high-energy bump reaching $\sim 300$ keV. Our results suggest a critical role played by $\omega_{ce}/\omega_{pe}$ and $T_e$ in determining the efficiency of electron acceleration by temperature anisotropy instabilities in solar flares.Comment: 11 pages, 9 figure

Intrahepatic cholangiocarcinoma: review and update

Cholangiocarcinoma (CCA) is a heterogeneous group of malignancies that could develop at any level from the biliary tree. CCA is currently classified into intrahepatic (iCCA), perihilar and distal on the basis of its anatomical location. Of note, these three CCA subtypes have common features but also important inter-tumor and intra-tumor differences that can affect the pathogenesis and outcome. A unique feature of iCCA is that it recognizes as origin tissues, the hepatic parenchyma or large intrahepatic and extrahepatic bile ducts, which are furnished by two distinct stem cell niches, the canals of Hering and the peribiliary glands, respectively. The complexity of iCCA pathogenesis highlights the need of a multidisciplinary, translational and systemic approach to this malignancy. This review will focus on the advances of iCCA epidemiology, histo-morphology, risk factors, molecular pathogenesis, revealing the existence of multiple subsets of iCCA

Reaction-diffusion equations: a chemical application

Obtenemos soluciones exactas para un sistema de reacción-difusión asociado a una reacción cubica autocatalítica entre dos sustancias químicas según la regla con tasa . Para obtener dichas soluciones empleamos una transformación de onda

The staging of gastritis with the olga system in the italian setting. histological features and gastric cancer risk

BACKGROUND: Recently OLGA (Operative Link on Gastritis Assessment) classification has been proposed to identify high-risk forms of gastritis that can evolve in gastric cancer (stages III and IV). Helicobacter pylori infection and age older than 40 have been considered as independent risk factor for high-risk OLGA stages

Bayesian and Multi-Armed Contextual Meta-Optimization for Efficient Wireless Radio Resource Management

Optimal resource allocation in modern communication networks calls for the optimization of objective functions that are only accessible via costly separate evaluations for each candidate solution. The conventional approach carries out the optimization of resource-allocation parameters for each system configuration, characterized, e.g., by topology and traffic statistics, using global search methods such as Bayesian optimization (BO). These methods tend to require a large number of iterations, and hence a large number of key performance indicator (KPI) evaluations. In this paper, we propose the use of meta-learning to transfer knowledge from data collected from related, but distinct, configurations in order to speed up optimization on new network configurations. Specifically, we combine meta-learning with BO, as well as with multi-armed bandit (MAB) optimization, with the latter having the potential advantage of operating directly on a discrete search space. Furthermore, we introduce novel contextual meta-BO and meta-MAB algorithms, in which transfer of knowledge across configurations occurs at the level of a mapping from graph-based contextual information to resource-allocation parameters. Experiments for the problem of open loop power control (OLPC) parameter optimization for the uplink of multi-cell multi-antenna systems provide insights into the potential benefits of meta-learning and contextual optimization

Rule-Based Lloyd Algorithm for Multi-Robot Motion Planning and Control with Safety and Convergence Guarantees

This paper presents a distributed rule-based Lloyd algorithm (RBL) for multi-robot motion planning and control. The main limitations of the basic Loyd-based algorithm (LB) concern deadlock issues and the failure to address dynamic constraints effectively. Our contribution is twofold. First, we show how RBL is able to provide safety and convergence to the goal region without relying on communication between robots, nor neighbors control inputs, nor synchronization between the robots. We considered both case of holonomic and non-holonomic robots with control inputs saturation. Second, we show that the Lloyd-based algorithm (without rules) can be successfully used as a safety layer for learning-based approaches, leading to non-negligible benefits. We further prove the soundness, reliability, and scalability of RBL through extensive simulations, an updated comparison with the state of the art, and experimental validations on small-scale car-like robots

El Triásico de la región de Monterde-Alhama de Aragón (Provincia de Zaragoza)

Se estudian los materiales en facies Buntsandstein y Muschelkalk de los afloramientos triásicos situados entre Monterde y el Norte de Alhama de Aragón. Para ello se han levantado siete columnas estratigráficas, habiéndose obtenido dos de ellas con un mayor detalle. Después de establecerse seis grandes tramos (unidades litoestratigráficas informales), claramente diferenciables, se estudian las variaciones verticales dentro de cada uno de ellos, así como las relaciones entre los mismos. En las reconstrucciones paleogeográficas y en la evolución sedimentaria> se resalta tanto la existencia de importantes umbrales durante la génesis de las tres unidades inferiores, como la transición gradual de depósitos marinos a continentales, y la presencia de interrupciones sedimentarias que, a veces, originan paleosuelos bien desarrollados. [RÉSUMÉ] On a studié les materiaux en faciés Buntsandstein et Muschelkalk des afleurments triassiques compris entre Monterde et le nord d'Alhama de Aragón. On a levé sept colonnes, dont deux en détaille. Aprés avoir établi six unités litostratigraphiques informelles trés differentes, on a étudié les variations verticales de chaque une ainsi que ses relations mutuelles. On fait sortir des importants seuils pendant la genése des trois unités inferieures par les reconstructions paléogéographiques et l'evolution sédimentaire, ainsi que la transition paulatine des dépots continentaux a marins et divers interruptions de la sedimentation, soulignés parfois par des paleochenaux. [AB5TRACT] The Buntsandstein and Muschelkalk facies have been surveyed in the outcrops between Monterde and the North of Alhama de Aragón. Seven stratigraphic sections have been studied, two in greater detail. After stablishing six informal lithostratigraphical units, very different each other, thcir vertical variations are studied as well as their mutual relations. The palaeogeogi-aphic reconstructions and the sediníentary evolution point out the existence of several shoals during tSe genesis of tSe three lower units as well as tSe transition from continental to marine deposits and several sedimentary breaks, sometimes niarked by paleosoils

Innovations in Chewable Formulations: The Novelty and Applications of 3D Printing in Drug Product Design

Since their introduction, chewable dosage forms have gained traction due to their ability to facilitate swallowing, especially in paediatric, geriatric and dysphagia patients. Their benefits stretch beyond human use to also include veterinary applications, improving administration and palatability in different animal species. Despite their advantages, current chewable formulations do not account for individualised dosing and palatability preferences. In light of this, three-dimensional (3D) printing, and in particular the semi-solid extrusion technology, has been suggested as a novel manufacturing method for producing customised chewable dosage forms. This advanced approach offers flexibility for selecting patient-specific doses, excipients, and organoleptic properties, which are critical for ensuring efficacy, safety and adherence to the treatment. This review provides an overview of the latest advancements in chewable dosage forms for human and veterinary use, highlighting the motivations behind their use and covering formulation considerations, as well as regulatory aspects