121 research outputs found

    Modeliranje vremena sušenja praha Candesartan Cilexetil primjenom tehnike računalne inteligencije

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    The aim of this work was to use two computational intelligence techniques, namely, artificial neural network (ANN) and support vector regression (SVR), to model the drying time of a pharmaceutical powder Candesartan Cilexetil, which is used for arterial hypertension treatment and heart failure. The experimental data set used in this work has been collected from previously published paper of the drying kinetics of Candesartan Cilexetil using vacuum dryer and under different operating conditions. The comparison between the two models has been conducted using different statistical parameters namely root mean squared error (RMSE) and determination coefficient (R2). Results show that SVR model shows high accuracy in comparison with ANN model to predict the non-linear behaviour of the drying time using pertinent variables with {R2 = 0.9991, RMSE = 0.262} against {R2 = 0.998, RMSE = 0.339} for SVR and ANN, respectively. This work is licensed under a Creative Commons Attribution 4.0 International License.Cilj ovog rada bio je primjena dvije tehnike računalne inteligencije (umjetne neuronske mreže (ANN) i regresije potpornih vektora (SVR)) za modeliranje vremena sušenja farmaceutskog praha Candesartan Cilexetil, koji se primjenjuje za liječenje arterijske hipertenzije i zatajenje srca. Eksperimentalni skup podataka korišten u ovom radu prikupljen je iz prethodno objavljenog rada o kinetici sušenja Candesartan Cilexetila pomoću vakuumskog sušionika i pod različitim radnim uvjetima. Usporedba između dva modela provedena je pomoću različitih statističkih parametara, odnosno korijenom srednje kvadratne pogreške (RMSE) i koeficijenta određivanja (R2). Rezultati su pokazali da u usporedbi s modelom ANN model SVR pokazuje visoku točnost za predviđanje nelinearnog ponašanja vremena sušenja koristeći odgovarajuće varijable {R2 = 0,9991, RMSE = 0,262} u odnosu na {R2 = 0,998, RMSE = 0,339} za SVR i ANN. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    Umjetna inteligencija i matematičko modeliranje kinetike sušenja farmaceutskog praha

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    The study aims at modelling the drying kinetics of a pharmaceutical powder with active ingredient Candesartan Cilexetil. The kinetics was carried out in a vacuum dryer at different temperature levels, pressure, initial mass, and water content. The effect of some operating parameters on the drying time was studied. The modelling of drying times was based on the use of experimental design method. The data obtained were adjusted using 17 semi-empirical models, one proposed, a static ANN and DA_SVMR, regrouping all studied kinetics. The proposed model and DA_SVMR model were chosen as the most appropriate to describe the drying kinetics. This work is licensed under a Creative Commons Attribution 4.0 International License.Cilj rada je modeliranje kinetike sušenja farmaceutskog praha s aktivnim sastojkom Candesartan Cilexetil. Kinetika je izvedena u vakuumskoj sušilici pri različitim temperaturama, tlaku, početnoj masi i sadržaju vode. Proučavan je utjecaj nekih radnih parametara na vrijeme sušenja. Modeliranje vremena sušenja temeljilo se na primjeni eksperimentalne metode dizajna. Dobiveni podatci prilagođeni su pomoću 17 poluempirijskih modela, jednog predloženog, statičkog ANN i DA_SVMR, pregrupirajući svu proučavanu kinetiku. Predloženi model i model DA_SVMR pokazali su se kao najprikladniji za opisivanje kinetike sušenja. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

    Remediation of acid mine drainage and immobilization of rare earth elements: Comparison between natural and residual alkaline materials

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    Acid mine drainage (AMD) is a well-known source of toxic trace metals in freshwaters. Traditional passive treatment systems rely on AMD neutralization with limestone and removal of most common toxic transition metals such as Cu and Zn with little attention to rare earth elements (REE). Alkaline waste materials now receive increasing attention as low cost AMD treatment alternatives in the circular economy. This study was set up to identify the efficiency of alkaline waste materials remediating AMD and scavenging REE in addition to other toxic trace elements. An AMD sample was collected from a lixiviate coming from pyrite heaps in the Iberian Pyrite Belt (pH =1.8, 30 μM ∑REY). The sample was treated with either blast furnace slag (BFS) generated during smelting of iron ore in a blast furnace or biomass ashes (BA) derived from combustion of biomass, thereby using analytical grade CaCO3, and NaOH as reference products. The batch alkalinization experiments were conducted by adding each alkaline material at an amount to obtain an equal pH to ≈6.5. The required amounts of the products were NaOH 99%) and the remaining REE concentrations in the solutions were clearly lower than values for Cu and Zn. The Zn and Cu removals were not consistently high enough (except with NaOH) to meet environmental limits in the discharge waters. The largest efficiency for REE removals was obtained with CaCO3. Indirect evidence here suggests that gypsum is a better host for the trivalent REE than Fe(III) minerals in the precipitates. The ionic radii of trivalent REE are more similar to Ca2+than to Fe3+, explaining the better potential of gypsum as REE host. This study showed also the potential of BFS as alkaline agent for the remediation of AMD in terms of its higher alkalinity generation potential as compared to BA, thus making BA less promising than BFSThis research has received funding from European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska- Curie Grant Agreement No 857989. C.R C´anovas thanks the Spanish Ministry of Science and Innovation for the Postdoctoral Fellowship granted under application reference RYC2019-027949-I. The authors gratefully acknowledge the valuable assistance of the following people as well: Dr. Raul Moreno Gonzalez from the Department of Earth Sciences, University of Huelva in Spain for assistance in collecting acid mine water samples; Dr. Quoc Tri Phung from SCK CEN in Belgium for assistance in obtaining BFS samples; Dr. Lander Frederickx from SCK CEN in Belgium for supporting in XRD analysis; Dr. Claudia Moens, Mr. Benoit Bergen and Ms. Kristin Coorevits, ICP-MS Team, Division of Soil and Water management, KU Leuven for their enormous assistance in measuring ICP-MS samples; All the technicians of the Waste and Disposal Group, SCKCEN for their assistance in various ways. Authors also thank ENCE Energía y Celulosa Company for providing the B

    Population structure of the recent invader Hemigrapsus takanoi and prey size selection on Baltic Sea mussels

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    The shore crab Hemigrapsus takanoi Asakura and Watanabe, 2005, native to the Northwest Pacific, was recorded in European waters about 25 years ago and it was first found in the Baltic Sea in 2014. Information on population structure of invaders and their new niche is needed in order to understand their biological impact. Over one year, we assessed temporal changes in relative abundance, size-class and sex ratio, as well as breeding season of H. takanoi in the Kiel Fjord (Western Baltic Sea). In addition, prey size preference and consumption rates on mussels (Mytilus edulis Linnaeus, 1758) were experimentally assessed in spring, summer and autumn. A total of 596 individuals were collected with highest and lowest abundances in June and February, respectively. Females were dominant over males (sex ratio 1.4:1), but males grew to larger sizes. H. takanoi reproduced between June and August with ovigerous females representing 30% of the entire female abundance registered over the entire year. Males were able to open larger mussels (due to larger claws) and consumed twice as many mussels when compared to females of similar size. Consumption rates for males were 6 and 2 times higher in summer (seawater temperature of 19 °C) compared to spring (8 °C) and autumn (13 °C), respectively. Females consumed 3 times more mussels in autumn than in spring. H. takanoi is an active predator, capable of reproduction in stressful brackish water conditions. Due to large abundances and high feeding pressure, this recently introduced species could play a key role in structuring post-settlement population dynamics of the dominant habitat builder M. edulis

    5‑Substituted Pyridine-2,4-dicarboxylate Derivatives Have Potential for Selective Inhibition of Human Jumonji‑C Domain-Containing Protein 5

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    Jumonji-C domain-containing protein 5 (JMJD5) is a 2-oxoglutarate (2OG)-dependent oxygenase that plays important roles in development, circadian rhythm, and cancer through unclear mechanisms. JMJD5 has been reported to have activity as a histone protease, as an Nε-methyl lysine demethylase, and as an arginine residue hydroxylase. Small-molecule JMJD5-selective inhibitors will be useful for investigating its (patho)physiological roles. Following the observation that the broad-spectrum 2OG oxygenase inhibitor pyridine-2,4-dicarboxylic acid (2,4-PDCA) is a 2OG-competing JMJD5 inhibitor, we report that 5-aminoalkyl-substituted 2,4-PDCA derivatives are potent JMJD5 inhibitors manifesting selectivity for JMJD5 over other human 2OG oxygenases. Crystallographic analyses with five inhibitors imply induced fit binding and reveal that the 2,4-PDCA C5 substituent orients into the JMJD5 substrate-binding pocket. Cellular studies indicate that the lead compounds display similar phenotypes as reported for clinically observed JMJD5 variants, which have a reduced catalytic activity compared to wild-type JMJD5

    Convergence of Humans, Bats, Trees, and Culture in Nipah Virus Transmission, Bangladesh.

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    Preventing emergence of new zoonotic viruses depends on understanding determinants for human risk. Nipah virus (NiV) is a lethal zoonotic pathogen that has spilled over from bats into human populations, with limited person-to-person transmission. We examined ecologic and human behavioral drivers of geographic variation for risk of NiV infection in Bangladesh. We visited 60 villages during 2011-2013 where cases of infection with NiV were identified and 147 control villages. We compared case villages with control villages for most likely drivers for risk of infection, including number of bats, persons, and date palm sap trees, and human date palm sap consumption behavior. Case villages were similar to control villages in many ways, including number of bats, persons, and date palm sap trees, but had a higher proportion of households in which someone drank sap. Reducing human consumption of sap could reduce virus transmission and risk for emergence of a more highly transmissible NiV strain
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