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Archaeobotanical research of the Roman port Barbir in Sukošan
No full textU ovom je diplomskom radu napravljena arheobotanička analiza biljnih ostataka sakupljenih
u antičkoj luci Barbir u Sukošanu, koja se koristila od 1. do 5. stoljeća. Ukupno je obrađeno
13 uzoraka sakupljenih 2019. i 2020. godine iz kojih je izolirano ukupno 525,25 biljnih
nekarboniziranih makrofosila. Determinirano je ukupno 24 biljnih svojti, a po najvećoj
brojnosti ističu se: obična smokva (Ficus carica L.), pitoma maslina (Olea europaea L.),
morska resa (Cymodocea nodosa (Ucria) Asch.), vinova loza (Vitis vinifera ssp. vinifera
L./sylvestris (C. C. Gmel.) Hegi), obična kupina (Rubus fruticosus L. agg.) i pinija (Pinus
pinea L.). Ostale svojte čine samo 6,71 % pronađenih biljnih ostataka. Kultivirane i korisne
drvenaste biljke su bile najbrojnije makrofosilima i čine čak 78,98 % analiziranih ostataka. Iz
usporedbe s drugim istraživanjima antičkih lokaliteta na hrvatskoj obali Jadrana i drugdje u
Sredozemlju vidi se da su biljke pronađene u antičkoj luci Barbir očekivani biljni predstavnici
mediteranskih korisnih drvenastih i zeljastih biljaka, što upućuje na zaključak da je tadašnje
stanovništvo uzgajalo i koristilo tipične sredozemne biljke.In this thesis, an archaeobotanical analysis of plant remains collected from the ancient harbor
of Barbir in Sukošan has been conducted. The harbor was in use from the 1st to the 5th
century. A total of 13 samples collected in 2019 and 2020 were processed, yielding 525.25
non-carbonized macrofossils of plants. A total of 24 plant taxa were identified, with the most
abundant ones being: common fig (Ficus carica L.), domesticated olive (Olea europaea L.),
Mediterranean seagrass (Cymodocea nodosa (Ucria) Asch.), grapevine (Vitis vinifera ssp.
vinifera L./sylvestris (C. C. Gmel.) Hegi), common blackberry (Rubus fruticosus L. agg.), and
stone pine (Pinus pinea L.). Other taxa constituted only 6.71% of the identified plant remains.
Cultivated and useful woody plants were the most abundant in macrofossils, accounting for
78.98% of the analyzed remains. A comparison with other studies of ancient sites along the
Croatian Adriatic coast and elsewhere in the Mediterranean region reveals that the plants
found in the ancient harbor of Barbir are representative of expected Mediterranean useful
woody and herbaceous plant species. This suggests that the inhabitants of that time cultivated
and utilized typical Mediterranean plants
Comparison of different statistical models to predict mortality from COVID
No full textOvaj rad sadržava najbitnije teorijske rezultate vezane za višeparametarsku linearnu regresiju te primjenu tih rezultata na predviđanje smrtnosti od COVID-a. U prvom poglavlju naveli smo neke osnovne definicije iz vjerojatnosti i statistike koji su korisni za ostatak rada. Drugo poglavlje započeli smo s definicijom jednostavne linearne regresije koju smo odmah proširili na složenu linearnu regresiju. Objasnili smo metodu najmanjih kvadrata i dali njezinu geometrijsku interpretaciju. Dokazali smo Gauss - Markovljev teorem i spomenuli test hipoteza. U trećem poglavlju obradili smo metode odabira podskupa uključujući odabir najboljeg podskupa, stepenastu selekciju unaprijed i unazad te etapnu regresiju unaprijed. Osim toga, dotaknuli smo se metoda sažimanja, točnije ridge i lasso regresije. U zadnjem, četvrtom poglavlju počinjemo graditi modele višestruke linearne regresije promatrajući prvo udio zaraženih kao zavisnu varijablu, a nakon toga i udio umrlih od virusa.This paper contains the most important theoretical results related to multiple linear regression and the application of these results in predicting COVID mortality. In the first chapter we mentioned some basic probability and statistics definitions that are useful for further work. We started the second chapter with the definition of simple linear regression, which we immediately expanded to multiple linear regression. We explained the method of least squares and gave its geometric interpretation. We proved the Gauss-Markov theorem and mentioned hypothesis testing. In the third chapter, we covered subset selection methods including best subset selection, forward stepwise selection, backward stepwise selection and forward stagewise regression. Additionally, we touched on shrinkage methods, specifically ridge and lasso regression. In the final, fourth chapter, we begin to build multiple linear regression models, first considering the share of infected as a dependent variable, and then the share of deaths from the virus
Adaptive laboratory evolution of bacterium Geobacillus thermoglucosidasius in extreme enironmental conditions
No full textKako bi se smanjila koncentracija CO2 u zraku, znanstvenici pokušavaju koristiti bakterije kao stanične tvornice koje bi hvatale dodatni CO2 te pomoću procesa mineralizacije ga “reciklirale” i kasnije koristili u različitim granama industrije. Ovaj rad se bazira na adaptivnoj laboratorijskoj evoluciji tri soja bakterije Geobacillus thermoglucosidasius. Ova termofilna i gram-pozitivna bakterija može rasti pri maksimalnoj vrijednosti pH od 8.5 te temperaturi od 70°C. U ovom je istraživanju provedena adaptivna laboratorijska evolucija na okoliš gdje prevladava alkalni pH (>8.5) te temperatura viša od 70°C: uvjeti koji odgovaraju ugljičnoj anhidrazi. To je esencijalno jer je jednom od korištenih sojeva pomoću genetske modifikacije ugljična anhidraza, enzim koji hvata ugljik, pričvršćena za staničnu stijenku. Također, jedan je od ciljeva bio i usporediti efikasnost protokola rađenog ručno s automatiziranim protokolom. Rezultati su pokazali 4 zajedničke mutacije na genima šest replika dobivenih ručno rađenim protokolom zbog adaptacije na pH 9.1. Replike dobivene automatiziranim protokolom su imale 4 zajedničke mutacije na jednoj skupini sojeva i 1 na drugoj. Dostignuti pH je 9.01. Adaptivna laboratorijska evolucija se još jednom dokazala korisnom za optimizaciju staničnih tvornica za industrijsku upotrebu te se ručno rađeni protokol dokazao efikasnijim od automatiziranog.To fight high CO2 emissions scientists are trying to use bacteria as cell factories to capture extra CO2 via mineralisation to “recycle” it and use it in different industries. This study aimed to use adaptive laboratory evolution on three strains of Geobacillus thermoglucosidasius. This thermophilic and gram-positive bacterium can grow at a maximum of 8.5 pH and 70°C temperature. One of the strains was genetically modified to express a carbonic anhydrase, the enzyme that enables carbon capture, anchored to its cell wall. The goal was to adapt these strains to an environment that is defined by alkaline pH (> 8.5) and temperature higher than 70°C: the conditions that favour carbonic anhydrase activity. We also wanted to compare the efficiency of a manually performed protocol versus automation. The results demonstrated 4 common mutations among 6 manually executed replicates that managed to adapt to 9.1 pH. Automatically performed replicates reached a maximum pH of 9.01 and had 4 common mutations for one set of replicates and 1 common mutation for the second set. Overall, adaptive laboratory evolution once more proved useful for optimizing cell factories for industrial applications and the manual protocol performed better than the automatic one
Cultivation of industrial hemp in Croatia
No full textCilj rada bio je predstaviti samu industrijsku konoplju te ispitati pogodnosti uzgoja na poljoprivrednim površinama u Hrvatskoj. Istraženo je i kako industrijska konoplja utječe na krajolik te koje su njezine prednosti. Analiziran je prostor Republike Hrvatske te detaljnije uzgoj u zadnjih deset godina, a obuhvaća analizu površina pod industrijskom konopljom, sadnje, uzgoja, žetve te prerade konoplje i proizvoda od konoplje. Uz prikupljanje podataka iz znanstvenih i stručnih radova te različitih internetskih izvora, u radu analiziran je intervju koji se provodio s uzgajivačimai prodavačimaindustrijske konoplje, apodatci o uzgoju su kartografski prikazani. Trenutni prioritet leži u edukaciji ne samo ostalog stanovništva nego i poljoprivrednika o industrijskoj konoplji i njezinim prednostima. Pokazalo se da uzgoj konoplje raste kao posljedica promjene zakona o uzgoju. Poljoprivrednici se odlučuju na konoplju zbog pozitivnog utjecaja koji ima na tlo i zbog kvalitete i cijene konačnih proizvoda.The main goal of the paper was to present industrial hemp and to examine the benefits of growing it on agricultural land in Croatia. The paper also investigated how industrial hemp affects the landscape and its advantages. The area of the Republic of Croatia was analyzed, the cultivation in the last ten years more specifically, also including the analysis of areas with industrial hemp, planting, cultivation, harvesting and processing of hemp and hemp products. In addition to the collection of data from scientific and professional works and various Internet sources, the paper analyzed interviews that were conducted with growers and sellers of industrial hemp, and the cultivation data were presented cartographically. The current priority lies in educating farmers and the rest of the population about industrial hemp and its advantages. Hemp cultivation has been shown to increase as a result of the change in cultivation laws. Farmers choose hemp because of the positive impact it has on the soil and because of the quality and price of the final products
Quantum-chemical docking of heterocycles into the active site of butyrylcholinesterase using deep reinforcement learning
No full textAlzheimerova bolest teška je i neizlječiva neurološka bolest koju karakterizira gubitak kognitivnih sposobnosti pojedinca. Simptomi uključuju demenciju te promjene u ponašanju i osobnosti bolesnika, a bolest predstavlja jedan od vodećih uzroka smrti u svijetu. Prema kolinergičkoj hipotezi, u mozgu oboljelih osoba smanjena je koncentracija neurotransmitera acetilkolina te se za povećanje njegove koncentracije kao lijekovi koriste inhibitori acetilkolinesteraze i butirilkolinesteraze. Ti inhibitori u svojoj strukturi često sadrže heterocikličke sustave te su u ovom radu istraženi konfiguracijski prostori malih heterocikličkih molekula u aktivnom mjestu butirilkolinesteraze. Molekule aziridina i azetidina te njihove kombinacije dokirane su korištenjem kvantno-kemijskog Monte Carlo dokiranja. Za pretraživanje konfiguracijskih prostora primijenjen je protokol računalstva s velikom propusnošću, a za 100 struktura najniže energije provedene su dodatne optimizacije geometrije i izračuni standardnih Gibbsovih energija vezanja. Pokazano je da se energija dokiranih molekula u aktivnom mjestu butirilkolinesteraze može uspješno procijeniti korištenjem duboke neuronske mreže istrenirane algoritmom dubokoga pojačanog učenja.Alzheimer's disease is a severe and incurable neurological disease that is characterized by the loss of an individual's cognitive abilities. Symptoms are dementia and changes in the patient's behavior and personality, and the disease is one of the leading causes of death in the world. According to the cholinergic hypothesis, the concentration of the neurotransmitter acetylcholine is reduced in the brain of affected individuals, and acetylcholinesterase and butyrylcholinesterase inhibitors are used as drugs to increase its concentration. These inhibitors often contain heterocyclic systems in their structure, and in this work the configurational spaces of small heterocyclic molecules in the active site of butyrylcholinesterase were investigated. Aziridine and azetidine molecules and their combinations were docked using quantum- chemical Monte Carlo docking. A high-throughput computing protocol was applied to search the configurational spaces, and additional geometry optimizations as well as calculation of standard Gibbs binding energies were performed for the 100 lowest energy structures. It has been shown that the energy of docked molecules in the active site of butyrylcholinesterase can be successfully estimated using a deep neural network trained by deep reinforcement learning
Specific effects of ions on the formation and properties of poly(allylamine hydrochloride)/poly(acrylic acid) multilayer
No full textPolielektrolitni kompleksi i višeslojevi poli(alilamin-hidroklorida) i poli(akrilne kiseline) pripravljeni su u vodenim otopinama NaF, NaCl, NaClO4, LiCl i (CH3)4NCl. Nastanak polielektrolitnih kompleksa po prvi puta istražen je visoko-razlučivom ultrazvučnom spektroskopijom. Ovom metodom ustanovljeno je da interpolielektrolitna neutralizacija rezultira ion-specifičnom agregacijom nabijenih koloidnih kompleksa. Analogan utjecaj iona određen je u slučaju odgovarajućih višeslojeva. Elipsometrom i mikroskopom atomskih sila utvrđeno je da debljina i hrapavost filma raste u nizu F− < Cl− < ClO4− za anione odnosno (CH3)4N+ < Na+ < Li+
za katione. Nadalje, ustanovljeno je da hidrofobnost višesloja također slijedi opisani trend za anione kada je polikation završni sloj filma. Zagrijavanjem polielektrolitnih višesloja tijekom njihove priprave potisnut je specifičan utjecaj iona na površinsku hrapavost i močivost zbog reorijentacije i migracije polimernih lanaca na međupovršini višesloj/zrak. Naposlijetku, provedeno istraživanje ukazuje na značajnu korelaciju između procesa interpolielektrolitne neutralizacije u otopini i na površini.Polyelectrolyte complexes and multilayers of poly(allylamine hydrochloride) and poly(acrylic acid) were prepared in aqueous solutions of NaF, NaCl, NaClO4, LiCl, and (CH3)4NCl. The formation of polyelectrolyte complexes was investigated for the first time by high-resolution ultrasonic spectroscopy. Using this method, it was established that interpolyelectrolyte neutralization results in ion-specific aggregation of charged colloidal complexes. Analogous influence of ions was observed in the case of corresponding multilayers. Using ellipsometer and atomic force microscope, it was determined that the thickness and roughness of the film increases in the sequence F− < Cl− < ClO4− for anions and (CH3)4N+ < Na+ < Li+ for cations. Furthermore, it was found that the hydrophobicity of the multilayer also follows the described trend for anions when a polycation is terminating layer of the film. By heating polyelectrolyte multilayers during their preparation, the specific influence of ions on surface roughness and wettability was suppressed due to the reorientation and migration of polymer chains at the multilayer/air interface. Finally, the conducted research indicates a significant correlation between the process of interpolyelectrolyte neutralization in solution and on the surface
Total synthesis of penicyclone A
No full textPeniciklon A je poliketid izoliran iz kulture dubokomorske gljivice Penicillium Sp. F32-2. Zanimljiva struktura ovog prirodnog spoja koji sadrži spiro[5.5]laktonsku jezgru i četiri stereogena centra te prijavljena antimikrobna aktivnost potaknule su studije o njegovoj totalnoj sintezi. U ovom radu istražena su tri fundamentalno različita pristupa sintezi peniciklona A. Prvi pristup temeljio se na razvoju oksidativne dearomatizacije fenola te daljnje funkcionalizacije dobivenog cikloheksadienona regioselektivnom cis-dihidroksilacijom. Drugi pristup temeljio se na korištenju D-(+)-kvininske kiseline kao polaznog spoja, dok se treći pristup temeljio na razvoju dijastereoselektivne dvostruke adicije Grignardovih reagensa na literaturno poznati lakton izveden iz D-riboze. Peniciklon A je uspješno pripravljen trećim pristupom. Sintetski peniciklon A pokazao je različito optičko skretanje od prirodnog materijala te nedostatak antimikrobne aktivnosti što je potaknulo sintezu i drugog enantiomera, također iz D-riboze.Penicyclone A is a polyketide isolated from the deep-sea fungus Penicillium Sp. F32-2. Its interesting structure containing a spiro[5.5]lactone core and four stereogenic centers and the reported antimicrobial activity prompted studies in its total synthesis. Three fundamentally different approaches to the synthesis of penicyclone A were investigated. The first approach was based on the development of an oxidative dearomatization of phenols and further functionalization of the obtained cyclohexadienone by regioselective cis-dihydroxylation. The second approach was based on the use of D-(-)-quinic acid as a starting compound, while the third approach was based on the development of a diastereoselective double Grignard reaction. Penicyclone A was successfully prepared using the third approach. Synthetic penicyclone A showed differences in optical rotation and a lack of antimicrobial activity. This prompted the synthesis of the second enantiomer
Kvantno-mehaničko tuneliranje
No full textKvantno-mehaničko tuneliranje podrazumijeva transmisiju neke čestice ili većeg sustava u klasično nedozvoljeno područje. Sam efekt prvi je otkrio njemački fizičar Friedrich Hund proučavajući molekulske spektre te ga je opisao u radovima izdanima 1927. godine. Iste godine efekt kvantno-mehaničkog tuneliranja primijetio je i Lothar Nordheim proučavajući termionsku emisiju elektrona, a u nadolazećim godinama primjećen je još u mnogim sustavima te je aktivno istraživan još i danas. Uz to što kvantno-mehaničko tuneliranje objašnjava brojne prirodne procese kao što su nukleosinteza, dinamika vodikove veze i alfa raspad, ima i brojne primjene u industriji poput proizvodnje poluvodiča i supervodiča, dioda, tranzistora te pretražnog mikroskopa s tuneliranjem. U ovome je radu objašnjen efekt kvantno-mehaničkog tuneliranja na primjeru pravokutne potencijalne barijere za koji je izveden izraz za vjerojatnost transmisije neke čestice u ovisnosti o zadanim parametrima tog sustava. Također, opisana je i značajna uloga efekta tuneliranja u dinamici vodikove veze, u kojoj se događa transmisija vodikovog atoma u međumolekulskom prostoru, te u alfa raspadu jezgara određenih teških metala
Origin and composition of biogenous sediment of the Lojišće Beach, Dugi otok
No full textPrema prethodnim istraživanjima, zaključeno je da je sediment plaže Lojišće sastavljen
primarno od karbonatnog pijeska biogenog porijekla veličine oko 0,2 mm. Uzorak pijeska gotovo
u potpunosti čine krhotine skeleta i ljuštura organizama. S obzirom da je materijal usitnjen, zbog
veličine zrna nemoguće je zaključiti koje skupine organizama su pridonijele njegovom stvaranju.
U jednoj od rijetkih prilika kada je pijesak bio izbačen na plažu, a prije nego je bio usitnjen
valovima, prikupljen je uzorak krupnog sedimenta iz kojeg je moguće prepoznati pojedine skupine
organizama. U krupnom uzorku dovoljno je očuvanih i prepoznatljivih krhotina, cijelih ljuštura i
drugih dijelova organizama koji mogu dati detaljniji uvid u sastav sedimenta.According to past researches, it has been concluded that sediment from the beach
Lojišće is composed primarily of biogenic carbonate sand sized approximately 0,2 mm. The
sample of the sand is almost entirely made of shell fragments. Considering the small size of these
fragments, it is normally impossible to determine which organisms contributed to its genesis.
However, the sample of sand used in this research was collected from the beach on one of the rare
occasions before the fragments were weathered and broken down by waves, which enabled
macroscopic sorting, since the fragments remained large enough to still be visible with naked eye.
This coarse-grained sample contains preserved grains, fragments of shells and other organism
remains, enabling a more detailed insight into the composition of the sedimen
Synthetic route development for the preparation of the conjugate of D-glucose and diethylenetriaminepentaacetic acid (DTPA)
No full textU sklopu ovog diplomskog rada pripravljen je „late-stage” međuprodukt koji se sastoji od benzilirane D-glukoze i trietilen-glikol-ditosilata (10) u svrhu priprave konjugata D-glukoze i dietilentriaminpentaoctene kiseline (DTPA) (1). Konjugat 1 teranostički je agens koji se može koristiti u ciljanoj dostavi radiofarmaceutika u stanice raka, a sve u svrhu radioterapije i/ili dijagnostike. Ukupna struktura konjugata 1 sastavljena je od tri jedinice: D-glukoze, trietilenglikola i DTPA. U ovom radu ispitana je uspješnost nekoliko različitih sintetskih pristupa u pripravi spoja 1. Rad uključuje sintezu, pročišćavanje, izolaciju i karakterizaciju dobivenih
međuprodukata. Sam cilj ovog rada je pronalazak efikasne sintetske rute do spoja 1 sa što manje koraka, a sa što većim prinosom, polazeći iz komercijalno dostupnih spojeva. Dobiveni spojevi okarakterizirani su spektroskopskim metodama (IR, 1H i 13C NMR).In this diploma thesis „late-stage” intermediate for the preparation of the conjugate of D-glucose and diethylenetriaminepentaacetic acid (DTPA) (1) was synthesized, consisting of benzylated D-glucose and triethylene glycol ditosylate (10). Conjugate 1 is a theranostic agent, whose structure can be used for the selective delivery of radiopharmaceutics into cancer cells with the aim of a radiotherapy treatment and/or diagnostics. The full structure of 1 is comprised of: D-glucose, triethylene glycol and DTPA. In this work, the effectiveness of several different synthetic approaches in the preparation of compound 1 was examined. The thesis includes the synthesis, purification, isolation and characterization of prepared intermediates in the synthetic route. The aim of this work is to find an efficient synthetic route towards compound 1 with as few steps as possible, and with as high a yield as possible, starting from commercially available compounds. Obtained compounds were characterized with spectroscopic methods (IR, 1H and 13C NMR)