14 research outputs found
Different phenotypic manifestations between Brazilian and Japanese patients with anti-MDA5 autoantibody-positive dermatomyositis: longitudinal, tricentric, and international study
No full textIntrodução: O autoanticorpo anti-melanoma differentiation-associated gene 5 (anti-MDA5) está fortemente associado a doença pulmonar intersticial (DPI) e DPI rapidamente progressiva (DPI-RP), sobretudo em pacientes asiáticos com dermatomiosite (DM) e DM clinicamente amiopática (DMCA). Entretanto, essa associação não tem sido bem estabelecida em pacientes brasileiros com DM/DMCA. Objetivos: Comparar a prevalência de acometimento pulmonar entre os pacientes brasileiros e japoneses com DM/DMCA anti-MDA5(+). Secundariamente, comparar as características demográficas, clínicas, laboratoriais, terapêuticas e evolutivas destes pacientes. Métodos: Este estudo de coorte retrospectivo foi conduzido entre 2003 e 2023, com pacientes adultos com DM (EULAR/ACR, 2017) e DMCA (Gerami et al., 2006), e com autoanticorpo anti-MDA5 positivo, em seguimento em centros terciários (um brasileiro e dois japoneses). A DPI ao diagnóstico foi definida como aguda (3 meses) ou se o paciente se apresentava assintomático; pacientes com DPI-RP sendo definida como presença de DPI associada a dispneia e hipoxemia num período 3 months), or if the patient was asymptomatic; patients were diagnosed with RP-ILD if they presented with ILD associated with dyspnea and hypoxemia within a period of <3 months of diagnosis. Results: Of the 108 patients, 38 (35.2%) were Brazilian and 70 (64.8%) were Japanese. The mean age of Brazilian and Japanese patients at diagnosis of the disease was 42.9±13.7 and 53.3±14.8 years, respectively (P <0.001), with a predominance of females in both groups. The median duration between the onset of symptoms and the diagnosis of the disease was 4.5 (1.8-13.0) and 2.0 (1.0-4.0) months (P =0.001), while the median follow-up times for these patients were 52 (21-77 and 49 (22-89) months (P =0.890). Of the Brazilian patients, 22 (57.9%) and 16 (42.1%) had DM and CADM, respectively, and 12 (17.1%) and 58 (82.9%) Japanese patients had DM and CADM. Brazilian patients had a higher frequency of weight loss, heliotrope, V neck sign, calcinosis, digital ulcers, Raynauds phenomenon, dysphagia, and muscle weakness. In comparison, the Japanese had a higher frequency of mechanic\'s hands. Laboratory characteristics and the presence of dyspnea were similar between the two groups. However, the prevalence of ILD was significantly lower in the Brazilian sample than in the Japanese sample (47.4% vs . 98.6%, P<0.001). Acute ILD was observed in 10.5% and 44.3% of Brazilian and Japanese patients, respectively (P <0.001), whereas RP-ILD was observed in one (2.6%) Brazilian patient and 36 (51.4%) Japanese patients (P<0.001). There was no significant difference in the use of pulse therapy with methylprednisolone and intravenous human immunoglobulin at the onset of the disease between the two groups. However, aggressive triple therapy with corticosteroids, cyclophosphamide, and calcineurin inhibitors introduced early was common only in Japanese patients. The distribution of infections, neoplasms, disease reactivation, and death was comparable between the two samples. Conclusions: Brazilian patients had a lower frequency of ILD and RP-ILD than Japanese patients, and they demonstrated a less severe clinical profile such that early aggressive initial therapy commonly used in Japanese centers was unnecessary. The phenotypic variability of patients with anti-MDA5(+) DM/CADM appears to be influenced by several factors, including ethnicit
Refocusing vector assessment towards the elimination of onchocerciasis from Africa: a review of the current status in selected countries
No full textMeasures to control onchocerciasis have been in place for well over 30 years. Recently, programs have turned from disease control towards transmission elimination. The absence of infective larvae in the black fly Simulium sp. vector is central to defining elimination, and assessments of infectivity by O150 polymerase chain reaction in the vector not only provide valuable information to programs, but are also required for verification of elimination. The status of transmission in black flies was assessed in five countries in the African region during 2014 and 2015. Several of these countries were evaluated because of promising results from epidemiological studies in humans. No infective flies were found in two countries. Infective flies were found in the other three, despite the absence of infection in humans (as evaluated by skin-snip microscopy). Ongoing transmission as demonstrated in the black flies could be due to a variety of factors, including lack of treatment of hypo-endemic areas and cross-border issues. Challenges identified during the course of the entomological work suggest that there is a need for improved selection of vector collection sites and vector collection periods in order to improve fly catches. Two important challenges to achieving elimination identified were definition of the hypo-endemic zones and establishing the existence of areas of cross-border transmission occurring between countries.Full Tex
Granulometrijska analiza drvne sječke
No full textIstraživanje je postavljeno s ciljem utvrđivanja primjenjivost mehaničkoga uređaja za vibracijsko prosijavanje na uzorcima drvne sječke i ovisnosti granolumetrijske strukture drvne sječke o ulaznoj sirovini.
Uzorkovanje je obavljeno prilikom iveranja energijskoga drva izvezenoga iz odjeka 23 A i 35 B na pomoćna stovarišta gospodarske jedinice „Kapelački lug-Karaš“ u Šumariji Donji Miholjac Uprave šuma podružnice Našice trgovačkoga društva „Hrvatske šume“ d.o.o. Iveranje je na oba stovarišta obavljeno primjenom vučenog iverača Eschlböch Biber 80.
Zbog nedostupnosti normom propisanoga instrumentarija, u trenutku istraživanja, granulometrijska analiza drvne sječke provedena je mehaničkim uređajem za vibracijsko prosijavanje tipa CISA RP.08 sa sitima dimenzija 2,8 mm, 8,0 mm i 16,0 mm.
Ukupno je obrađeno šest uzoraka drvne sječke; četiri uzorka energijskoga drva iz 23 A odsjeka i dva uzorka energijskoga drva iz 35 B odsjeka.
Na temelju razultata istraživanja nije moguće zaključiti da je iveranjem energijskoga drva iz 23 A odsjeka i iz 35 B odsjeka iveračem Eschlböch Biber 80 proizvedena drvna sječka značajno različite granulometrijske strukture. Naime, odstupanja granulometrijske strukture pojedinih uzoraka od prosječnih vrijednosti ne pružaju dovoljno uporište za tvrdnju kako bi različit sastav energijskoga drva po vrstama drveća rezultirao bitno različitim granulometrijskim strukturam proizvedene sječke. Razlozi ovih rezultata mogu biti posljedica sličnosti između energijskoga drva iz dvije istraživane sječine, ali i nedovoljnoga intenziteta uzorkovanja.
U svakom slučaju razultati istraživanja ukazuju na nužanost nastavka i intenziviranja znanstvenih istraživanja kakvoće drvne sječke iz šuma Republike Hrvatske s ciljem uspostave referentnih vrijenosti za pojedine šumske zajednic
Choke manifold : master’s thesis
No full textBušenje je kompleksan tehnološki proces, često popraćen brojnim problemima, a jedan od njih je i dotok, koji može dovesti do erupcije. Ukoliko se dotok pojavi, tada je potrebno isključiti isplačne pumpe, zatvoriti bušotinu pomoću preventera, iscirkulirati dotok kroz vod za prigušivanje bušotine, te ugušiti bušotinu utiskivanjem otežane isplake u svrhu vraćanja bušotine pod kontrolu. Vod za prigušivanje bušotine vodi prema razdjelniku podesive sapnice, na kojemu se nalaze ventili i podesive sapnice, a služi za smanjenje tlaka dotoka na atmosferski tlak, a nakon toga se fluid, otvaranjem i zatvaranjem ventila, usmjerava kroz tlačne vodove prema isplačnoj jami, vibracijskim sitima, separatoru plina ili baklji, ovisno o potrebi.Well drilling is a demanding technological process, usually followed by many problems, and one of those problems is the entry of the formation fluid into the wellbore, known as kick, which can eventually lead to blowout. If the kick occurs, it is necessary to shut down the mud pump(s), close the well by activating blowout preventers, circulate the fluid out through choke line, and kill the well by pumping heavy drilling mud into the wellbore. Choke line, connected to the drilling spool, leads to the choke manifold, on which valves and chokes are located, and its purpose is to reduce the fluid pressure to atmospheric one. After that, by opening and closing certain valves on the choke manifold, the fluid is directed through pressure lines either to the mud pit, shakers, gas separator or flare
THE PELLETS APPLICATION IN LABORATORY RESEARCHING OF INHIBITIVE MUD/SHALE INTERACTION
No full textNestabilnost kanala bušotine predstavlja ozbiljan problem koji se najčešće javlja tijekom bušenja kroz šejl. Uzrok nestabilnosti šejla proizlazi iz njegovog mineraloškog sastava (osobito udjela minerala glina) i njegovih fizikalno-kemijskih karakteristika. Do sada su provedena brojna laboratorijska ispitivanja s ciljem definiranja osnovnih uzroka nestabilnosti šejla i utvrđivanja svojstava šejla koja utječu na njegovo ponašanje u kontaktu s vodenom fazom različitih isplaka. U tim ispitivanjima korišteni su uzorci šejla dobiveni procesom jezgrovanja ili krhotine šejla sakupljene na vibracijskim sitima, ali i različiti uzorci šejla iz površinskih kopova, te je teško usporediti dobivene rezultate. Provođenje opsežnih laboratorijskih ispitivanja i usporedba dobivenih rezultata moguća je upotrebom umjetno stvorenih uzoraka šejla (peleta) točno određenog mineraloškog sastava. U radu su opisana laboratorijska ispitivanja bubrenja peleta određenog mineraloškog sastava u inhibiranim isplakama.Wellbore instability appears to be a serious problem during drilling process through shale. Shales instability cause basically comes out of its mineralogical composition (especially clay minerals content) and physico-chemical properties. Many research activities about shale instability causes and shale properties (affecting shale behavior during interaction with water phase of different drilling muds) definition have been carried out by now. In these laboratory tests were used original shales samples given by coring process or collecting shale cuttings from shale shakers, and different shale samples from outcrop. From this reason is very difficult compare laboratory tests results given by different authors. Possible solution is use artificial shale samples (pellets) with exact mineralogical composition, enabling extensive laboratory tests and tests results comparison. In this paper presented laboratory tests of pellets swelling in inhibitive muds
MODELLING OF THE ISOMERIZATION PROCESS FOR THE PURPOSE OF ADVANCING MOTOR GASOLINE QUALITY
No full textSažetak
U radu je postavljen matematički model odabranog modela izomerizacije. Pri postavljanju modela proces je istražen sa stajališta reakcijskog mehanizma, kinetike reakcija izomerizacije, te parametara kemijske ravnoteže. Simulacijski model reaktora izveden je prema postavljenim materijalnim bilancama, a modelom su opisani i procesi izmjene topline, te procesi izmjene tvari postupcima separacije.
Postavljeni simulacijski model omogućio je istraživanje i proučavanje optimalnih radnih uvjeta procesa simuliranjem, te je predloženo unapređenje procesa sa stajališta povećanja prinosa visokooktanskog produkta procesa izomerizacije, kao i povećanja oktanskog broja proizvoda.
Rezultati dobiveni simuliranjem procesa unaprijeđenog dodatkom kolone za deizopentanizaciju pokazali su povećanje iscrpka izomerizata za čak 42% u usporedbi s procesom bez unapređenja, dok je izvedba procesa s molekulskim sitima rezultirala značajnim povećanjem istraživačkog oktanskog broja proizvoda od 9 jedinica. Rezultati simuliranja procesa bez unapređenja i procesa s kolonom deizopentanizera pokazali su vrlo dobro slaganje s eksperimentalnim podacima industrijskog procesa.Abstract
The paper defines a mathematical model of the chosen isomerization model. While setting the model, the process was explored from the viewpoint of reaction mechanism, isomerization reactions kinetics, and chemical balance parameters. The reactor simulation model has been elaborated according to the set material balances, while the model describes also the heat exchange processes, as well as those of substance exchange using separation procedures.
The set simulation model has enabled research and study of optimal operating process conditions using simulation, and process advancement has been suggested from the viewpoint of increasing the yield of the high octane isomerization process product, as well as the yield of the product octane number.
The results obtained through the simulation of the process advanced by the addition of the deisopentanizer column have shown an increased isomerate yield by as much as 42% compared with the process without advancement, while the process implementation with molecular sieves has resulted in a considerable increase of the product research octane number of 9 units. The results of process simulation without advancement and those of the process with deisopentanizer column have shown very good match with the experimental data of the industrial process
Reduction of dustiness in sawing wood by universal circular saw
No full textCilj je provedenih istraživanja usporedba raspodjele veličina čestica usitnjenog materijala nastaloga longitudinalnim propiljivanjem drva kružnom pilom s dva lista različitog tipa zubi. Istraživanje je provedeno na univerzalnoj kružnoj pili pri brzini rezanja v = 50 m·s-1 i posmičnoj brzini vf = 16 m·min-1. Korišteni su listovi pile s asimetričnim trobridnim razvraćenim zubima K1 i sa stlačenim zubima K2. Odabrani su uzorci relativne vlažnosti od 8 do 10% od smrekovine, bukovine i merantija, drvnog materijala tipičnog za proizvodnju europrozora. Granulometrijska analiza uzoraka provedena je na tresilici proizvođača Fritch i sitima veličina (stranice kvadratnih otvora) 1,0; 0,5: 0,355; 0,1; 0,05 sa dnom. Svaki uzorak prosijavan je 15 minuta, uz tri ponavljanja. Rezultati pokazuju da pri piljenju listom pile K2 nastaju krupnije čestice te da je nastalo 25% više čestica merantija krupnijih od 1 mm nego pri piljenju listom pile K1. Za sve tri ispitivane vrste drva značajno je da nastane dvostruko manje čestica sitnijih od 100 mikrometara, tzv. lebdećih čestica (sito 0,05 s dnom) piljenjem pilom K2 negoli pilom K1. Iako dobiveni uzorci nisu sadržavali znatniji udio sitnih lebdećih čestica, zbog njihovoga štetnog utjecaja na zdravlje radnika, nužno je skrenuti pozornost na to da se odgovarajućim izborom alata može smanjiti udio drvnih čestica sitnijih od 100 mikrometara.The aim of this paper is a comparison of particle size distribution of sawdust in longitudinal sawing of wood by the universal circular saw when using two saw blades with different types of teeth.
Experiments were carried out by use of a universal circular saw, at the cutting speed of v = 50 m·s-1 and feed speed of vf= 16 m·min-1. A universal saw blade with triangular asymmetric spring setting teeth K1 was used as a tool, as well as a saw blade with tipped swaged teeth K2. Specimens were used of spruce, beech and meranti wood with moisture content from 8 to 10%, species otherwise typical of the production of Euro windows. Granulometric analysis of produced sawdust was carried out by a sieve machine Fritch, with the set of sieves whose mesh gauge were as follows 1.0, 0.5, 0.355, 0.1, 0.05 and the bottom. Each specimen was meshed for 15 minutes and three specimens were meshed for each variant. The results show that larger chips were produced with the use of the saw blade K2 – the proportion of 1mm mesh, where the difference in using these two types of blades was up to 25% - meranti. From the viewpoint of airborne particles, it should be emphasised that with all three species of wood, the production of particles smaller than 100 micrometers (0.05 and bottom mesh) was twice lower when sawing was carried out with the saw blade K2 than with the saw blade K1. Even though the share of fine fraction was not considerable in the obtained samples, it can be stated that these amounts are also hazardous for the work environment and therefore attention should be drawn to the results of these experimental measurements, as it is possible to affect the proportion of fine fraction smaller than 100 micrometers by an adequate choice of tool
Investigation of interaction between pesticides and microplastic particles
No full textOnečišćenje mora plastičnim otpadom jedan je od najhitnijih globalnih problema morskog okoliša u cijelom svijetu. Privukao je svjetsku pozornost vlada, javnosti, znanstvene zajednice, medija i nevladinih organizacija te je postao vruća tema u aktualnoj morskoj ekologiji i istraživanju okoliša. Cilj ovog rada bio je istražiti utjecaj temperature i starosti mikroplastike poli(etilen- tereftalata) (PET) na adsorpciju pesticida simazina (SMZ). Korištene su čestice mikroplastike (10-100 μm) pripremljene iz nestarenih filmova PET-a te filmova podvrgnutim ubrzanom starenju 56 dana pod UV zračenjem. Nakon usitnjavanja u kriomlinu određena je raspodjela veličina čestica mikroplastike, pri čemu su za razdvajanje frakcija korišteni vibrirajuća tresilica sa sitima i laboratorijsko sito sa zračnim mlazom. Adsorpcijski eksperimenti provedeni su korištenjem termostatirane laboratorijske tresilice, a promjene koncentracije simazina praćene su tekućinskom kromatografijom visoke djelotvornosti (HPLC). Na kraju su ispitani pojedinačni štetni učinci mikroplastike i simazina te ukupni učinci mikroplastike s adsorbiranim onečišćivalom, provedbom standardnih testova akutne toksičnosti na zelene mikroalge Pseudokirchneriella subcapitata (ISO 8692). Rezultati ATR-FTIR spektroskopijesu pokazali da se UV starenjem povećava udio manjih frakcija čestica mikroplastike, što znači da je zbog utjecaja starenja materijal više podložan fragmentaciji, te je došlo do oksidativne razgradnje koja rezultira stvaranjem funkcionalnih skupina koje sadrže kisik (smanjena hidrofobnost materijala). Rezultati adsorpcije simazina slijede Langmuirovom model što ukazuje na adsorpciju u monosloju te je raspodjela aktivnih mjesta na adsorbensu homogena. Adsorpcija je izraženija u slučaju starenih uzoraka u odnosu na uzorke mikroplastike koji nisu stareni, te je najveća adsorpcija simazina postignuta uz PET 56 pri temperaturi od 20°C. Ispitivanje toksičnosti na zelenim mikroalgama Pseudokirchneriella subcapitata pokazalo je najveću toksičnost kod kombiniranih uzoraka simazina sa starenom mikroplastikom (PET 56) i CaCl2.The pollution of the sea by plastic waste is one of the most urgent global problems of the marine environment all over the world. It has attracted worldwide attention from governments, the public, the scientific community, the media and non-governmental organizations and has become a hot topic in current marine ecology and environmental research. The aim of this work was to investigate the influence of temperature and age of poly(ethylene-terephthalate) (PET) microplastics on the adsorption of the pesticide simazine (SMZ). Microplastic particles (10-100 μm) prepared from pristine PET films and films subjected to accelerated aging were used 56 days under UV radiation were used. After grinding in a cryomill, the particle size distribution of microplastics was determined, using a vibrating shaker with sieves and a laboratory sieve with an air jet were used to separate the fractions. Adsorption experiments were carried out using a thermostated laboratory shaker, and changes in simazine concentration were monitored by high-performance liquid chromatography (HPLC). In the end, the individual harmful effects of microplastics and simazine and the overall effects of microplastics with adsorbed pollutant were tested by performing standard acute toxicity tests on the green microalgae Pseudokirchneriella subcapitata (ISO 8692). The results of ATR-FTIR spectroscopy showed that UV aging increases the proportion of smaller fractions of microplastic particles, which means that due to the influence of aging, the material is more susceptible to fragmentation, and oxidative decomposition has occurred, which results in the formation of functional groups containing oxygen (reduced hydrophobicity of the material). The results of simazine adsorption follow the Langmuir model, which indicates adsorption in a monolayer and the distribution of active sites on the adsorbent is homogeneous. Adsorption is more pronounced in the case of aged samples compared to pristine microplastic samples, and the highest simazine adsorption was achieved with PET 56 at a temperature of 20°C. The toxicity test on the green microalgae Pseudokirchneriella subcapitata showed the highest toxicity with the combined samples of simazine with aged microplastic (PET 56) and CaCl2
Investigation of interaction between pesticides and microplastic particles
No full textOnečišćenje mora plastičnim otpadom jedan je od najhitnijih globalnih problema morskog okoliša u cijelom svijetu. Privukao je svjetsku pozornost vlada, javnosti, znanstvene zajednice, medija i nevladinih organizacija te je postao vruća tema u aktualnoj morskoj ekologiji i istraživanju okoliša. Cilj ovog rada bio je istražiti utjecaj temperature i starosti mikroplastike poli(etilen- tereftalata) (PET) na adsorpciju pesticida simazina (SMZ). Korištene su čestice mikroplastike (10-100 μm) pripremljene iz nestarenih filmova PET-a te filmova podvrgnutim ubrzanom starenju 56 dana pod UV zračenjem. Nakon usitnjavanja u kriomlinu određena je raspodjela veličina čestica mikroplastike, pri čemu su za razdvajanje frakcija korišteni vibrirajuća tresilica sa sitima i laboratorijsko sito sa zračnim mlazom. Adsorpcijski eksperimenti provedeni su korištenjem termostatirane laboratorijske tresilice, a promjene koncentracije simazina praćene su tekućinskom kromatografijom visoke djelotvornosti (HPLC). Na kraju su ispitani pojedinačni štetni učinci mikroplastike i simazina te ukupni učinci mikroplastike s adsorbiranim onečišćivalom, provedbom standardnih testova akutne toksičnosti na zelene mikroalge Pseudokirchneriella subcapitata (ISO 8692). Rezultati ATR-FTIR spektroskopijesu pokazali da se UV starenjem povećava udio manjih frakcija čestica mikroplastike, što znači da je zbog utjecaja starenja materijal više podložan fragmentaciji, te je došlo do oksidativne razgradnje koja rezultira stvaranjem funkcionalnih skupina koje sadrže kisik (smanjena hidrofobnost materijala). Rezultati adsorpcije simazina slijede Langmuirovom model što ukazuje na adsorpciju u monosloju te je raspodjela aktivnih mjesta na adsorbensu homogena. Adsorpcija je izraženija u slučaju starenih uzoraka u odnosu na uzorke mikroplastike koji nisu stareni, te je najveća adsorpcija simazina postignuta uz PET 56 pri temperaturi od 20°C. Ispitivanje toksičnosti na zelenim mikroalgama Pseudokirchneriella subcapitata pokazalo je najveću toksičnost kod kombiniranih uzoraka simazina sa starenom mikroplastikom (PET 56) i CaCl2.The pollution of the sea by plastic waste is one of the most urgent global problems of the marine environment all over the world. It has attracted worldwide attention from governments, the public, the scientific community, the media and non-governmental organizations and has become a hot topic in current marine ecology and environmental research. The aim of this work was to investigate the influence of temperature and age of poly(ethylene-terephthalate) (PET) microplastics on the adsorption of the pesticide simazine (SMZ). Microplastic particles (10-100 μm) prepared from pristine PET films and films subjected to accelerated aging were used 56 days under UV radiation were used. After grinding in a cryomill, the particle size distribution of microplastics was determined, using a vibrating shaker with sieves and a laboratory sieve with an air jet were used to separate the fractions. Adsorption experiments were carried out using a thermostated laboratory shaker, and changes in simazine concentration were monitored by high-performance liquid chromatography (HPLC). In the end, the individual harmful effects of microplastics and simazine and the overall effects of microplastics with adsorbed pollutant were tested by performing standard acute toxicity tests on the green microalgae Pseudokirchneriella subcapitata (ISO 8692). The results of ATR-FTIR spectroscopy showed that UV aging increases the proportion of smaller fractions of microplastic particles, which means that due to the influence of aging, the material is more susceptible to fragmentation, and oxidative decomposition has occurred, which results in the formation of functional groups containing oxygen (reduced hydrophobicity of the material). The results of simazine adsorption follow the Langmuir model, which indicates adsorption in a monolayer and the distribution of active sites on the adsorbent is homogeneous. Adsorption is more pronounced in the case of aged samples compared to pristine microplastic samples, and the highest simazine adsorption was achieved with PET 56 at a temperature of 20°C. The toxicity test on the green microalgae Pseudokirchneriella subcapitata showed the highest toxicity with the combined samples of simazine with aged microplastic (PET 56) and CaCl2
Investigation of interaction between pesticides and microplastic particles
No full textOnečišćenje mora plastičnim otpadom jedan je od najhitnijih globalnih problema morskog okoliša u cijelom svijetu. Privukao je svjetsku pozornost vlada, javnosti, znanstvene zajednice, medija i nevladinih organizacija te je postao vruća tema u aktualnoj morskoj ekologiji i istraživanju okoliša. Cilj ovog rada bio je istražiti utjecaj temperature i starosti mikroplastike poli(etilen- tereftalata) (PET) na adsorpciju pesticida simazina (SMZ). Korištene su čestice mikroplastike (10-100 μm) pripremljene iz nestarenih filmova PET-a te filmova podvrgnutim ubrzanom starenju 56 dana pod UV zračenjem. Nakon usitnjavanja u kriomlinu određena je raspodjela veličina čestica mikroplastike, pri čemu su za razdvajanje frakcija korišteni vibrirajuća tresilica sa sitima i laboratorijsko sito sa zračnim mlazom. Adsorpcijski eksperimenti provedeni su korištenjem termostatirane laboratorijske tresilice, a promjene koncentracije simazina praćene su tekućinskom kromatografijom visoke djelotvornosti (HPLC). Na kraju su ispitani pojedinačni štetni učinci mikroplastike i simazina te ukupni učinci mikroplastike s adsorbiranim onečišćivalom, provedbom standardnih testova akutne toksičnosti na zelene mikroalge Pseudokirchneriella subcapitata (ISO 8692). Rezultati ATR-FTIR spektroskopijesu pokazali da se UV starenjem povećava udio manjih frakcija čestica mikroplastike, što znači da je zbog utjecaja starenja materijal više podložan fragmentaciji, te je došlo do oksidativne razgradnje koja rezultira stvaranjem funkcionalnih skupina koje sadrže kisik (smanjena hidrofobnost materijala). Rezultati adsorpcije simazina slijede Langmuirovom model što ukazuje na adsorpciju u monosloju te je raspodjela aktivnih mjesta na adsorbensu homogena. Adsorpcija je izraženija u slučaju starenih uzoraka u odnosu na uzorke mikroplastike koji nisu stareni, te je najveća adsorpcija simazina postignuta uz PET 56 pri temperaturi od 20°C. Ispitivanje toksičnosti na zelenim mikroalgama Pseudokirchneriella subcapitata pokazalo je najveću toksičnost kod kombiniranih uzoraka simazina sa starenom mikroplastikom (PET 56) i CaCl2.The pollution of the sea by plastic waste is one of the most urgent global problems of the marine environment all over the world. It has attracted worldwide attention from governments, the public, the scientific community, the media and non-governmental organizations and has become a hot topic in current marine ecology and environmental research. The aim of this work was to investigate the influence of temperature and age of poly(ethylene-terephthalate) (PET) microplastics on the adsorption of the pesticide simazine (SMZ). Microplastic particles (10-100 μm) prepared from pristine PET films and films subjected to accelerated aging were used 56 days under UV radiation were used. After grinding in a cryomill, the particle size distribution of microplastics was determined, using a vibrating shaker with sieves and a laboratory sieve with an air jet were used to separate the fractions. Adsorption experiments were carried out using a thermostated laboratory shaker, and changes in simazine concentration were monitored by high-performance liquid chromatography (HPLC). In the end, the individual harmful effects of microplastics and simazine and the overall effects of microplastics with adsorbed pollutant were tested by performing standard acute toxicity tests on the green microalgae Pseudokirchneriella subcapitata (ISO 8692). The results of ATR-FTIR spectroscopy showed that UV aging increases the proportion of smaller fractions of microplastic particles, which means that due to the influence of aging, the material is more susceptible to fragmentation, and oxidative decomposition has occurred, which results in the formation of functional groups containing oxygen (reduced hydrophobicity of the material). The results of simazine adsorption follow the Langmuir model, which indicates adsorption in a monolayer and the distribution of active sites on the adsorbent is homogeneous. Adsorption is more pronounced in the case of aged samples compared to pristine microplastic samples, and the highest simazine adsorption was achieved with PET 56 at a temperature of 20°C. The toxicity test on the green microalgae Pseudokirchneriella subcapitata showed the highest toxicity with the combined samples of simazine with aged microplastic (PET 56) and CaCl2
