wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: HULL HYDRODYNAMIC DERIVATIVES
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Synthesis and antiproliferative activity of conjugates of adenosine with muramyl dipeptide and nor-muramyl dipeptide derivatives
PublikacjaWe synthesized a series of MDP(D,D) and nor-MDP(D,D) derivatives conjugated with adenosine through a spacer as potential immunosuppressants. New conjugates were evaluated on two leukemia cell lines (Jurkat and L1210) and PBMC from healthy donors.
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Synthesis and biological activity of ester derivatives of mycophenolic acid and acridines/acridones as potential immunosuppressive agents
PublikacjaImproved derivatives of mycophenolic acid (MPA) are necessary to reduce the frequency of adverse effects, this drug exerts in treated patients. In this study, MPA was coupled with N-(x-hydroxyalkyl)-9-acridone-4-carboxamides or N-(x-hydroxyalkyl)acridine-4-carboxamides to give respective ester conjugates upon Yamaguchi protocol. This esterification required protection of phenol group in MPA. Designed conjugates revealed higher...
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Biochemical, Structural Analysis, and Docking Studies of Spiropyrazoline Derivatives
PublikacjaIn this study, we evaluated the antiproliferative potential, DNA damage, crystal struc‐ tures, and docking calculation of two spiropyrazoline derivatives. The main focus of the research was to evaluate the antiproliferative potential of synthesized compounds towards eight cancer cell lines. Compound I demonstrated promising antiproliferative properties, especially toward the HL60 cell line, for which IC50 was equal to 9.4 μM/L....
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A method for predicting propeller-hull interaction, applicable to preliminary design of inland waterways ships
PublikacjaW pracy przedstawiono propozycje metody parametrycznej służącej do prognozowania charakterystyk strumienia nadążającego i ssania kadłuba okrętu o zanurzeniu bliskim głębokości akwenu. Metoda umożliwia uwzględnienie wpływu małej głębokości akwenu przy wstępnym doborze parametrów układu napędowego statków przeznaczonych do eksploatacji na wodach płytkich, np. statków śródlądowych. Model matematyczny zagadnienia wyznaczono uwzględniając...
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Computer graphics toos application for visualsation of measurements results of ship hull sections and blocks.
PublikacjaOpisano zakres minimalnych wymagań dla programu komputerowego, służącego do wizualizacji wyników pomiarów sekcji i bloków kadłuba okrętowego. Przedstawiono sposób przenoszenia danych z urządzenia pomiarowego do programu i pokazano przykłady pomiarów wykonanych na sekcjach zbudowanych w Stoczni Gdynia S.A.
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Neural network based control system architecture proposal for underwatership hull cleaning robot.
PublikacjaPrzedstawiono model matematyczny podwodnej głowicy roboczej, oraz określono metodę jej pozycjonowania i orientacji w lokalnym środowisku. Zaproponowano architekturę układu sterowania, opartego na bazie sieci neuronowych, za pomocą którego można sterować podwodnym robotem, przeznaczonym do czyszczenia burt statku.
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Efficient synthesis and antifungal investigation of nucleosides’ quaternary ammonium salt derivatives
PublikacjaQuaternary ammonium salts are a group of compounds with diverse biological properties, the most important of which are their antiviral, antibacterial, and antifungal activities. The quaternization reactions of 5'-O-tosyl derivatives of uridine and thymidine with triethylamine, trimethylamine, 4-(N ,N -dimethylamino)pyridine, 2-methylpyridine, and pyridine are described in this article. Two of the synthesized compounds are exceptional...
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The absorption and fluorescence spectra of C-1305 derivatives (IKE1-IKE8), potential antifungal agents
Dane BadawczeOptical measurements of C-1305 derivatives (IKE1-IKE8). The absorption spectra were recorded at 300 - 800 nm for solutions with 16 μg / mL derivative concentration. The fluorescence emission spectra were determined at 420-800 nm with the excitation wavelengths 360 or 415 nm for solutions with 1 μg / mL derivative concentration. All measurements were...
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Molecular modeling and evaluation of novel dibenzopyrrole derivatives as telomerase inhibitors and potential drug for cancer therapy
PublikacjaDuring previous years, many studies on synthesis, as well as on anti-tumor, anti-inflammatory and anti-bacterial activities of the pyrazole derivatives have been described. Certain pyrazole derivatives exhibit important pharmacological activities and have proved to be useful template in drug research. Considering importance of pyrazole template, in current work the series of novel inhibitors were designed by replacing central...
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CHITOSAN-DERIVATIVES IN COMBINATIONS WITH SELECTED PORPHYRINOIDS AS NOVEL HYBRID MATERIALS FOR MEDICINE AND PHARMACY
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Targeting yeast topoisomerase II by imidazo and triazoloacridinone derivatives resulting in their antifungal activity
PublikacjaFungal pathogens are considered as serious factors for deadly diseases and are a case of medical concern. Invasive fungal infections also complicate the clinical course of COVID-19, leading to a significant increase in mortality. Furthermore, fungal strains' multidrug resistance has increased the demand for antifungals with a different mechanism of action. The present study aimed to identify antifungal compounds targeting yeast...
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Linear and Nonlinear Optical Properties of Azobenzene Derivatives Modified with an (Amino)naphthalene Moiety
PublikacjaThe design of two-photon absorbing azobenzene (AB) derivatives has received much attention; however, the two-photon absorption (2PA) properties of bis-conjugated azobenzene systems are relatively less explored. Here, we present the synthesis of six azobenzene derivatives and three bisazobenzenes substituted (or not) at para position(s) with one or two amino group(s). Their linear and nonlinear absorption properties are studied...
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Urban flash flood hazard identification and assessment applying geospatial techniques and hydrodynamic modeling; Erbil city case study, Kurdistan Region of Iraq
PublikacjaThis dissertation aims to investigate the factors behind flash flooding in Erbil's central district, located in the Kurdistan Region of Iraq, and develop a methodology for assessing flood hazards in the city, despite limited data accessibility. In this thesis, each factor was investigated, including analyzing extreme precipitation events in the last two decades, including their spatial and temporal distribution of rainfall, intensity,...
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Chemosensitization of multidrug resistant Candida albicans by the oxathiolone fused chalcone derivatives
PublikacjaThree structurally related oxathiolone fused chalcone derivatives appeared effective chemosensitizers, able to restore in part sensitivity to fluconazole of multidrug-resistant C.albicans strains. Compound 21 effectively chemosensitized cells resistant due to the overexpression of the MDR1 gene, compound 6 reduced resistance of cells overexpressing the ABC-type drug transporters CDR1/CDR2 and derivative 18 partially reversed fluconazole...
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Effect of chemical structure on complexation efficiency of aromatic drugs with cyclodextrins: The example of dibenzazepine derivatives
PublikacjaIt is widely believed that the hydrophobic effect governs the binding of guest molecules to cyclodextrins (CDs). However, it is also known that high hydrophobicity of guest molecules does not always translate to the formation of stable inclusion complexes with CDs. Indeed, a plethora of other factors can play a role in the efficiency of guest–CD interactions, rendering structure-based prediction of the complexation efficiency with...
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Hydrodynamic reanalysis of water temperature and salinity in the Baltic Sea using the PM3D model
Dane BadawczeThe dataset contains the results of numerical modeling of water temperature and salinity in the Baltic Sea since 1998. A long-term reanalysis was performed using the three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). A numerical dynamic-thermodynamic model of sea...
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Thermal Decomposition of Carbamoyl Meldrum’s Acids: A Starting Point for the Preparation of 1,3-Oxazine Derivatives
PublikacjaThe ability to undergo [4 + 2] versus [2 + 2] cycloaddition was under investigation for ketenes thermally generated from carbamoyl Meldrum’s acid. Usually, 1,3-oxazino-5-carbamoylo-4,6-diones are formed when carbamoyl Meldrum’s acid reacts with imine. However, in some cases, a reaction takes an unexpected course, leading to the formation of tetraponerines alkaloids derivatives or cyclic iminoethers.
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Tetrahydroquinolinone derivatives exert antiproliferative effect on lung cancer cells through apoptosis induction
PublikacjaThe anticancer properties of quinolones is a topic of interest among researchers in the scientific world. Because these compounds do not cause side effects, unlike the commonly used cytostatics, they are considered a promising source of new anticancer drugs. In this work, we designed a brief synthetic pathway and obtained a series of novel 8-phenyltetrahydroquinolinone derivatives functionalized with benzyl-type moieties at position...
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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublikacjaDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Xanthone synthetic derivatives with high anticandidal activity and positive mycostatic selectivity index values
PublikacjaWith the current massive increases in drug-resistant microbial infection as well as the significant role of fungal infections in the death toll of COVID-19, discovering new antifungals is extremely important. Natural and synthetic xanthones are promising derivatives, although only few reports have demonstrated their antifungal mechanism of action in detail. Newly synthetized by us xanthone derivative 44 exhibited strong antifungal...
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Hydrodynamic studies in magnetically assisted external-loop airlift reactor
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Hydrodynamic aspects of unconventional propulsor design for small fast ships.
PublikacjaArtykuł przedstawia przegląd niekonwencjonalnych pędników dla małych, szybkich okrętów. Przegląd ten obejmuje pędniki strugowodne, śruby superkawitacyjne, śruby częściowo zanurzone oraz śruby kawitujące. Charakterystyczne cechy hydrodynamiczne tych pędników wymieniono i przedyskutowano, ze wskazaniem wad i zalet. Pokrótce przedstawiono dostępne metody projektowania i przedyskutowano ich oczekiwaną dokładność. Przegląd zilustrowano...
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A short pictorial history of orthodox and unorthodox hydrodynamic marine propulsors.
PublikacjaReferat przedstawia historię rozwoju wybranych hydrodynamicznych pędników okrętowych, poczynając od czasów prehistorycznych. Prekursorem pędników jest ludzka dłoń - prymitywny ale skuteczny płat nośny. Koncepcja płata nośnego używanego w różnych konfiguracjach jest podstawą działania niemal wszystkich pędników okrętowych. W referacie opisano szczegółowo koła łopatkowe, będące w zasadzie zwielokrotnionymi wiosłami, pędniki cykloidalne...
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DEVELOPMENT OF A COUPLED NUMERICAL AND EXPERIMENTAL APPROACH TO HYDRODYNAMIC NOISE ESTIMATION
PublikacjaThe hydroacoustic signature of ships' propellers can be estimated experimentally through measurements of cavitation-induced pressure fluctuations and the corresponding noise distributions at model scale. These measurements need to be performed in a cavitation tunnel under the propellers operating conditions and are quite sensitive and challenging to perform with sufficient accuracy. In comparison, the numerical approach can be...
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Numerical Simulations of Hydrodynamic Open-Water Characteristics of a Ship Propeller
PublikacjaThe paper presents the results of numerical simulations of ship propeller operation bearing the name of Propeller Open Water (POW) Tests. The object of tests was a sample ship propeller (PPTC1), the geometrical and kinematic data of which are available, along with the results of model tests, on the official page of the research centre involved in the measurements. The research aimed at verifying the correctness of results of numerical...
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Using GPUs for Parallel Stencil Computations in Relativistic Hydrodynamic Simulation
PublikacjaThis paper explores the possibilities of using a GPU for complex 3D finite difference computation. We propose a new approach to this topic using surface memory and compare it with 3D stencil computations carried out via shared memory, which is currently considered to be the best approach. The case study was performed for the extensive computation of collisions between heavy nuclei in terms of relativistic hydrodynamics.
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Hydrodynamic functions of emulsion system agitated in the draft-tube reactor
PublikacjaPrzeprowadzono badania podstawowe sposobu wytwarzania emulsji w reaktorze pętlicowym z mieszaniem. Badano punkt inwersji faz oraz zapotrzebowanie mocy mieszania w zależności od składu emulsji. Zaobserwowano występowanie maksimum mocy mieszania w punkcie inwersji emulsji. Zaobserwowano liniową zależność prędkości cyrkulacji ciągłej fazy wodnej od częstości obrotów mieszadła śmigłowego.
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Palindromic carbazole derivatives: unveiling their antiproliferative effect via topoisomerase II catalytic inhibition and apoptosis induction
PublikacjaHuman DNA topoisomerases are essential for crucial cellular processes, including DNA replication, transcription, chromatin condensation, and maintenance of its structure. One of the significant strategies employed in cancer treatment involves the inhibition of a specific type of topoisomerase, known as topoisomerase II (Topo II). Carbazole derivatives, recognised for their varied biological activities, have recently become a significant...
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Piroxicam derivatives THz classification
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Activity of isavuconazole and other triazole derivatives against clinical isolates of Aspergillus fumigatus
PublikacjaAspergillus fumigatus is the most frequent pathogen of the genus Asperillus, which is highly susceptible to triazole derivatives, especially to isavuconazole and voriconazole. Many countries face a growing problem of infections due to A. fumigatus showing acquired resistance to one or several triazoles. In medical centres, monitoring the susceptibility of isolated Aspergillus spp. is recommended. The aim of this study was to collect...
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Report vconcerning corrosion reasons of s/y Lunar hull surface and possible way of repair
PublikacjaDokonano oceny korozji kadłuba jednostki pływającej, przyczyn powstania korozji oraz zaproponowano sposoby naprawy miejsc skorodowanych.
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An algorithm for preliminary estimating hull structure mass and mass centre height of inland navigation ships
PublikacjaPrzedstawiono algorytm obliczeniowy służący do wstępnego wyznaczania masy i wysokości środka ciężkości konstrukcji kadłuba statków śródlądowych. Algorytm opracowano opierając się na zaleceniach zawartych w Przepisach Klasyfikacji i Budowy Statków Śródlądowych PRS oraz zastosowano uproszczoną metodę wyznaczania mas usztywnień poszycia kadłuba. Algorytm dotyczy wymiarowania konstrukcji klasycznych statków służących do przewozu drobnicy,...
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Influence of cathodic-protection-induced hydrogenation on mechanical properties of two ship hull plate steels
PublikacjaPrzedstawiono wyniki próby rozciągania i udarowej Charpy V dla stali zwykłej wytrzymałości (kategorii A) i podwyższonej wytrzymałości (kat. AH32) zarówno w stanie dostawy jak i po nawodorowaniu (protektor Zn w słonej wodzie). Nawodorowanie obydwu stali zwiększyło nieco granicę plastyczności (Re) i wydłużenie (A), nie zmieniając (atal A) lub nieco zmniejszając przewężenie (Z). Wpływ nawodorowania na udarność był ewidentnie pozytywny...
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Novel Nystatin A1 derivatives exhibiting low host cell toxicity and antifungal activity in an in vitro model of oral candidosis
PublikacjaOpportunistic oral infections caused by Candida albicans are frequent problems in immunocompromised patients. Management of such infections is limited due to the low number of antifungal drugs available, their relatively high toxicity and the emergence of antifungal resistance. Given these issues, our investigations have focused on novel derivatives of the antifungal antibiotic Nystatin A1, generated by modifications at the amino...
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Hydrodynamic cavitation based advanced oxidation processes: Studies on specific effects of inorganic acids on the degradation effectiveness of organic pollutants
PublikacjaThe use of cavitation in advanced oxidation processes (AOPs) to treat acidic effluents and process water has become a promising trend in the area of environmental protection. The pH value of effluents – often acidified using an inorganic acid, is one of the key parameters of optimization process. However, in the majority of cases the effect of kind of inorganic acid on the effectiveness of degradation is not studied. The present...
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The organophosphorus sulfenyl bromides as versatile reagents for cysteine derivatives functionalization by unsymmetrical disulfide bond formation
PublikacjaWe have developed a convenient method for the synthesis of L-cysteine unsymmetrical disulfides under mild conditions with good to excellent yields. Described method is based on the straightforward preparation of the organophosphorus sulfenyl bromide readily available from bis-(5,5-dimethyl-2-thiono-1,3,2-dioxaphosphorinanyl) disulfide. The unsymmetrical disulfides can be obtained for L-cysteine derivatives and thiols bearing neutral...
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Opioid Growth Factor and its Derivatives as Potential Non-toxic Multifunctional Anticancer and Analgesic Compounds
PublikacjaIn this paper, we review the structure-activity relationship of OGF and its analogues. We highlight also OGF derivatives with analgesic, immunomodulatory activity and the ability to penetrate the blood-brain barrier and may be used as safe agents enhancing chemotherapy efficacy and improving quality of life in cancer patients. The reviewed papers indicate that Met-enkephalin and its analogues are interesting candidates for the...
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The comparison of antioxidant properties and nutrigenomic redox-related activities of vitamin C, C-vitamers, and other common ascorbic acid derivatives
PublikacjaThe term ‘vitamin C’ describes a group of compounds with antiscorbutic activity of L-ascorbic acid (AA). Despite AA’s omnipresence in plant-derived foods, its derivatives have also been successfully implemented in the food industry as antioxidants, including the D-isomers, which lack vitamin C activity. This study aimed to determine the relationship between redox-related activities for five derivatives of AA using electrochemical,...
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Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
PublikacjaDerivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally...
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The measurement of the velocity field around a ship hull mo-del in a tawing tank using PIV method
PublikacjaRozdział zawiera wyniki badań eksperymentalnych pola prędkości wokół modelukadłubu statku metodą PIV. Wykazano prawidłowość zastosowania metody PIV wtego typu badaniach.
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Estimation of interior-permanent-magnet-synchronous-motor rotor position by analysis of phase-current derivatives
PublikacjaThis paper describes an algorithm for estimation of IPMSM rotor angular position. The algorithm uses derivatives of motor phase currents resulting from PWM modulation to obtain the rotor position. The presented method is designed for medium- and high-speed range, since it is based on determination of the EMF vector. Calculation of the motor position is performed in every PWM cycle. The standard SV-PWM method is used to determine...
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Hydrodynamic Loads on Marine Propellers Subject to Ventilation and Out of Water Condition
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Hydrodynamic Loads on Marine Propellers Subject to Ventilation and Out of Water Condition
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Modelling and testing of a hydrodynamic clutch filled with electrorheological fluid in varying degree
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Decolorization of Congo red via hydrodynamic cavitation in combination with Fenton’s reagent
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Hydrological Forecasting in the Oder Estuary using a Three- Dimensional Hydrodynamic Model
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Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems
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Mesh dependence study for numerical assessment of hydrodynamic characteristics of windsurfing fin
PublikacjaThe presented research aims to assess the drag coefficient and lift coefficient versus angle of attack curves for windsurfing fin. Special attention in the research was being paid to the evaluation of the stall angle value. The angle of incidence for which the stall occurs was searched, and the sensitivity of the solution for the mesh resolution was studied. The mesh resolution sensitivity analysis was done by systematically decreasing...
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Synthesis and biological evaluation of thiophosphate tricyclic coumarin derivatives as steroid sulfatase inhibitors
PublikacjaSteroid sulfatase (STS) enzyme inhibition is an important approach to the management of hormone-dependent breast cancer. In this paper, we report convenient methods for the synthesis and biological evaluation of thiophosphate tricyclic coumarin analogs exhibiting STS activity. The described methods are based on the straightforward preparation of 7-hydroxy-2,3-dihydro-1H-cyclopenta[c]chromen-2-one, 3-hydroxy- 7,8,9,10-tetrahydro-6H-benzo[c]chromen-6-one,...
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Exposure scenario and risk assessment of infants and newborns to bisphenols and their derivatives from diapers
PublikacjaNewborns and infants are more sensitive to harmful compounds such as bisphenols and their derivatives because of their not fully developed detoxification mechanism. Exposure to these substances can lead to developmental problems and health consequences in adulthood. Since disposable baby diapers are used from the first days of life and remain in contact with the baby skin, it seems important to monitor the levels of endocrine disrupting chemicals...