Rasburicase in the treatment of hyperuricemia of newborns

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Anionic multiblock core cross-linked star copolymers via RAFT polymerization

Poly(2-acrylamido-2-methylpropane sulfonic acid) is a polyelectrolyte currently used in numerous industrial applications. Herein, we report the use of reversible addition fragmentation chain transfer (RAFT) polymerization to prepare a range of well-defined homopolymers and block copolymers of 2-acrylamido-2-methylpropane sulfonic acid (AMPS®) and either N-hydroxyethyl acrylamide (HEAm) or 4-acryloylmorpholine (NAM) as a comonomer. We also describe the one-pot synthesis of multiblock core cross-linked star copolymers of AMPS® and HEAm with low dispersities (<1.3). The influence of several parameters such as the cross-linker type, cross-linker to chain transfer agent (CTA) ratio, arm length and composition on the polymerization efficiency are investigated

Treatment and Long-Term Sequelae in Childhood Brain Tumors

In children treated for brain tumors, important deficits in cognitive development have been described. The reduction of Intelligence Quotient (IQ) is correlated with multiple conditions such as tumor location, obstructive hydrocephalus, surgical intervention, and above all, the use of radiotherapy, especially in young children. Demyelinization represents the most striking microscopic alteration following radiation: cerebral white matter's loss and failure to white matter development could partly account for changes in IQ score.Recently, combined chemo-radiotherapeutic approaches and the improvement of radiotherapy techniques have enabled the reduction of neurocognitive symptoms and improved the standard of life of childhood brain tumor survivors

Nutritional status in the pediatric oncology patients

Nutritional status plays a vital role in the growth of children. In pediatric patients, disease-related malnutrition is a dynamic and multifactorial process supported by several factors such as inflammation, increased energy expenditure, decreased intake or reduced utilization of nutrients. In pediatric patients with malignancies, sarcopenia may coexist with malnutrition, amplifying its negative impact on prognosis. Careful monitoring of nutritional status both at diagnosis and during chemotherapy treatment allows early detection of the risk and/or presence of malnutrition. A rapid and personalized nutritional intervention can improve adherence to treatment, reduce complications and improve the patients' quality of life

Functional multisite copolymer by one-pot sequential RAFT copolymerization of styrene and maleic anhydride

A Multisite copolymer with functionalizable units inserted at precise locations was synthesised by one-pot Reversible Addition–Fragmentation Chain-Transfer (RAFT) polymerization and sequential Single Monomer Unit Insertion (SMUI) and Chain Extension (ChainExt) using Styrene (Sty) and Maleic Anhydride (MAnh) as comonomers. The multisite copolymer was based on a polystyrene (PSty) backbone (ca. 5700 g mol−1) with MAnh units inserted locally at four positions in the backbone. First, a well-defined macroCTA (1400 g mol−1 – Đ = 1.07) was synthesised by optimized RAFT polymerization (high conversion, high livingness and low dispersity) of styrene (DP = 10) using industrial grade butyl-2-methyl-2-[(dodecylsulfanylthiocarbonyl)sulfanyl] propionate as chain transfer agent (CTA-Ester – 80% pure). Subsequently, the polystyrene macroCTA was used for one-pot SMUI using a small excess of MAnh monomer (DPtarget = 1.5). The copolymer was chain extended by styrene leading to a polystyrene backbone with MAnh units (1.5 in average) located in the middle of the chain. By repeating SMUI and ChainExt, several units of MAnh were inserted locally along the polystyrene backbone (every 10 units on average) to give a functionalizable multisite copolymer (Đ = 1.35). Long alkyl chains (stearyl) were added by esterification of maleic anhydride moieties to obtain branched architecture

“¿Seres o Bioceres?” Memes on agribusiness and the dispute of senses between nature and biodiversity in Argentina

El objetivo de este artículo es analizar desde una perspectiva etnográfica, los distintos sentidos que construyen memes relacionados con el agronegocio en Argentina en relación con la naturaleza y la biodiversidad.Los memes son piezas de comunicación gráfica que se masificaron con la cultura de internet y que la ciencia social ha definido como textos multimodales puestos en circulación para ser intercambiados y replicados en la expresión y discusión pública.Se generó un universo de 75 memes recolectados en redes sociales (Facebook y Twitter) entre junio del año 2021 y septiembre de 2022. En una primera instancia realizamos un análisis de su autoría (emisores anónimos y nominales), circulación y contenido, agrupándolos en dos categorías referidas a diferentes instancias del vínculo sociedad-naturalezas: a) la disputa entre agronegocio y agroecología, donde el agronegocio, liderado por investigación científica (p. e. Bioceres), representa su dominación y destrucción y b) biodiversidad y agronegocio, donde el Estado se muestra inerme frente a la destrucción de la biodiversidad, a la vez que legitima el modelo agroindustrial.Se concluye que los memes sobre agronegocio son, para algunos grupos sociales, una herramienta comunicativa que, usando el humor esa “forma amable de la desesperación” interpelan al lector-consumidor, buscando su identificación con el ideario de lucha contra el agronegocio, denunciando la destrucción de la biodiversidad en el proceso de acumulación por desposesión.bstract The aim of this paper is to analyze, from an ethnographic point of view, different meanings of memes about agribusiness and biodiversity in Argentina. Memes are pieces of graphic communication that became widespread with internet culture and that social science has defined as multimodal texts put into circulation to be exchanged and replicated in public expression and discussion. We collected on social media (Facebook and Twitter) an universe of 75 memes between June 2021 and September 2022. We first analysed their authorship (anonymous and nominal issuers), circulation and content, grouping them into two categories referring to different instances of the society-natures link: a) the dispute between agribusiness and agroecology, where agribusiness, led by scientific research (e.g. Bioceres), represents its domination and destruction and b) biodiversity and agribusiness, where the state shows itself to be helpless in the face of the destruction of biodiversity, while at the same time legitimising the agro-industrial model. It is concluded that memes about agribusiness are, for some social groups, a communicative tool that, using humour, that "gentle form of desperation", interpellates the reader-consumer, seeking his or her identification with the ideology of struggle against agribusiness, reporting biodiversity collapse in the process of accumulation by dispossession.Fil: Pereyra, Horacio Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lucero, Paula. Universidad Nacional de La Plata; ArgentinaFil: Mastrangelo, Andrea Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Misiones; Argentin

How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals

We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax–solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005–0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax–solvent–PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) &lt; ϕ* &lt; 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate species likely to be effective PPDs for particular wax systems

Improving the Brain Delivery of Chemotherapeutic Drugs in Childhood Brain Tumors

The central nervous system (CNS) may be considered as a sanctuary site, protected from systemic chemotherapy by the meninges, the cerebrospinal fluid (CSF) and the blood-brain barrier (BBB). Consequently, parenchymal and CSF exposure of most antineoplastic agents following intravenous (IV) administration is lower than systemic exposure. In this review, we describe the different strategies developed to improve delivery of antineoplastic agents into the brain in primary and metastatic CNS tumors. We observed that several methods, such as BBB disruption (BBBD), intra-arterial (IA) and intracavitary chemotherapy, are not routinely used because of their invasiveness and potentially serious adverse effects. Conversely, intrathecal (IT) chemotherapy has been safely and widely practiced in the treatment of pediatric primary and metastatic tumors, replacing the neurotoxic cranial irradiation for the treatment of childhood lymphoma and acute lymphoblastic leukemia (ALL). IT chemotherapy may be achieved through lumbar puncture (LP) or across the Ommaya intraventricular reservoir, which are both described in this review. Additionally, we overviewed pharmacokinetics and toxic aspects of the main IT antineoplastic drugs employed for primary or metastatic childhood CNS tumors (such as methotrexate, cytosine arabinoside, hydrocortisone), with a concise focus on new and less used IT antineoplastic agents