Croatian Digital Thesis Repository
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Istraživanje regulacije piruvat kinaze u kvascu Pichia pastoris i utjecaja njene overekspresije na proizvodnju antitijela
No full textThe goal of the thesis was to investigate whether the main regulatory mechanism of pyruvate kinase (Cdc19) in P. pastoris is allosteric activation by fructose-1,6-bisphosphate (FBP) as in Saccharomyces cerevisiae. To test this hypothesis, the pyruvate kinase gene (CDC19) in P. pastoris genome was substituted with mutant CDC19E397A, and strains were grown in ethanol as a carbon source. In S. cerevisiae, FBP activates pyruvate kinase (Cdc19) by interacting with the glutamate (Glu392). This regulation mechanism is important for Cdc19 inactivation in absence of glucose since it prevents futile cycling and enables gluconeogenic growth in nonfermentable carbon source. The analogous glutamate found in P. pastoris (Glu397) was replaced with alanine in a CRISPR-Cas9-mediated strategy and their growth in ethanol as a sole carbon source was determined. No differences in growth ability were observed, thus it was concluded that allosteric activation by FBP at Glu397 is not the main pyruvate kinase regulation mechanism in P. pastoris and there must be another key regulation mechanism or another interaction site important for allosteric regulation. Effects of CDC19ᴇ₃₉₇ᴀ overexpression in VHH antibody high-producing P. pastoris strain on VHH (Variable domain of the Heavy chain of the Heavychain antibody) yield were also evaluated by screening in glucose-limited conditions and results showed that CDC19ᴇ₃₉₇ᴀ overexpression can improve yield up to 2 fold.Cilj ovog rada bio je odrediti je li glavni regulacijski mehanizam piruvat kinaze u P. pastoris alosterička aktivacija pomoću frukoza-1,6-bisfosfata (FBP) kao kod Saccharomyces cerevisiae. Kako bi testirali ovu prepostavku, gen piruvat kinase (CDC19) u genomu P. pastoris je zamijenjen s CDC19E397A te su mutanti uzgajani na etanolu kao izvoru ugljika. U S. cerevisiae, FBP aktivira piruvat kinazu (Cdc19) ulazeći u interakciju s glutamatom (Glu392) te je ovaj regulatorni mehanizam važan za glukoneogeni rast na nefermentabilnim izvorima ugljika jer rezultira inaktivacijom Cdc19 te sprječava uzaludno kruženje metabolita u nedostatku glukoze. Analogni glutamat pronađen u P. pastoris (Glu397) je zamijenjen s alaninom koristeći CRISPR-Cas9 te je određivan rast mutanata na etanolu kao jedinom izvoru ugljika. Rezultati su pokazali jednak rast za mutante u usporedbi s divljim tipom iz čega se može zaljučiti da alosterička regulacija djelovanjem FBP-a na Glu397 nije glavni regulacijski mehanizam piruvat kinaze u P. pastoris te da mora postojati drugi mehanizam regulacije ili je neki drugi aminokiselinski ostatak ključan za alosteričku regulaciju Cdc19. Utjecaj overekspresije CDC19ᴇ₃₉₇ᴀ na prinos VHH antitijela u VHH proizvodnom soju P. pastoris je također ispitan u uvjetima limitacije glukozom. Rezultati su pokazali da overekspresija CDC19ᴇ₃₉₇ᴀ povećava proizvodnju VHH (Variable domain of the Heavy chain of the Heavychain antibody) prinos do 2 puta
Laboratory diagnostics of multiple myeloma
No full textMultipli mijelom aktivna je zloćudna bolest plazma stanica s izraženim oštećenjima drugih organa za razliku od stanja koje mu
prethode, monoklonske gamapatije neodređenog značaja i šuljajućeg mijeloma. Dolazi do stvaranja malignog klona plazma stanica koje sintetiziraju monoklonski imunoglobulin. Zbog njegovog nakupljanja, i potiskivanja funkcionalnih imunoglobulina, dolazi do najčešćih simptoma bolesti poput bolova u kostima, čestih infekcija, anemija, bubrežnog zatajenja i dr. Bolest je nepoznate etiologije, ali se pretpostavlja da joj pridonose genska predispozicija, izloženost zračenju i utjecaj okoliša. Druga je najčešća hematoonkološka bolest koja više zahvaća crnu nego bijelu rasu te više muškaraca od žena. Bolest se najčešće javlja između 65. i 72. godine života. Multipli mijelom neizlječiva je bolest, ali uz pomoć novih lijekova i autologne transplatacije matičnih stanica, postiže se puno dulje preživljenje i remisija bolesti. Laboratorijskim testovima dokazuju se monoklonski proteini, određuje se njihov tip te se kvantificiraju. Time se postavlja dijagnoza i prati uspješnost terapije. Elektroforeza serumskih proteina probirni je test za dokazivanje postojanja monoklonskog vrška. Određivanje slobodnih lakih lanaca u serumu probirni je test u kombinaciji s elektroforezom serumskih proteina i koristi se za praćenje bolesti te praćenje stanja nakon transplantacije koštane srži.
Imunofiksacijskom elektroforezom proteina klasicira se M-proteina. To je potvrdni test monoklonalnosti na temelju kojeg se može
donijeti diferencijalna dijagnoza mono-, bi- i triklonalnih gamapatija. Također, tim se testom provjerava relaps bolesti nakon
transplantacije koštane srži. Nalazi pacijenata s multiplim mijelomom često ukazuju na povišene koncentracije ukupnih proteina i
gama globulina, a koncentracija albumina je snižena. Uz to je sedimentacija eritrocita, kao biljeg upale i malignog procesa, ali i
viskoznosti krvi, ubrzana. Povišeni β-2-mikroglobulin loš je prognostički biljeg isto kao i hiperkalcijemija do koje dolazi zbog
osteolize u već uznapredovaloj bolesti. Cilj ovog diplomskog rada bio je prikazati mogućnosti biokemijskih metoda u dijagnostici
monoklonskih proteina kod sumnje na plazmastaničnu diskraziju. Koristeći se metodom kapilarne elektroforeze serumskih proteina monoklonski su vršci dokazani u 3 od 4 bolesnice, imunofiksacijom su potvrđeni tipovi monoklonskih proteina, a
imunoturbidimetrijom su kvantificirani. Navedene metode pomogle su u postavljanju dijagnoze i profiliranju fenotipa bolesti što je
preduvjet za daljnje liječenje.Multiple myeloma is an active malignant disease of plasma cells characterized by significant damage to other organs,
unlike its preceding conditions, monoclonal gammopathy of undetermined significance and smoldering myeloma.
The disease involves the formation of a malignant clone of plasma cells that synthesize monoclonal
immunoglobulin. Due to its accumulation and suppression of functional immunoglobulins, the most common
symptoms of the disease arise, such as bone pain, frequent infections, anemia, kidney failure, and others. The disease
has an unknown etiology, but it is believed that genetic predisposition, exposure to radiation, and environmental
factors contribute to it. It is the second most common hematologic malignancy, affecting Black people more than
White people, and men more than women. The disease most often occurs between the ages of 65 and 72. Multiple
myeloma is an incurable disease, but with the help of new drugs and autologous stem cell transplantation, much
longer survival and disease remission can be achieved. Laboratory tests detect monoclonal proteins, determine their
type, and quantify them. This establishes the diagnosis and monitors the effectiveness of therapy. Serum protein
electrophoresis is a screening test used to detect the presence of a monoclonal spike. The determination of free light
chains in serum is a screening test combined with serum protein electrophoresis, used for monitoring the disease
and post-bone marrow transplantation status. Immunofixation electrophoresis of proteins classifies the M-protein.
This is a confirmatory test for monoclonality, based on which a differential diagnosis of mono-, bi-, and triclonal
gammopathies can be made. Additionally, this test checks for relapse of the disease after bone marrow
transplantation. The laboratory findings of patients with multiple myeloma often indicate elevated levels of total
proteins and gamma globulins, while albumin concentration is reduced. Moreover, erythrocyte sedimentation rate
(as a marker of inflammation and malignant processes, but also blood viscosity) is accelerated. Elevated β-2-
microglobulin is a poor prognostic marker, as is hypercalcemia, which occurs due to osteolysis in advanced stages
of the disease. The aim of this thesis was to present the possibilities of biochemical methods in the diagnosis of
monoclonal proteins in suspected plasma cell dyscrasias. Using the method of capillary serum protein
electrophoresis, monoclonal spikes were detected in 3 out of 4 female patients, the types of monoclonal proteins
were confirmed by immunofixation, and they were quantified by immunoturbidimetry. These methods helped
establish the diagnosis and profile the disease phenotype, which is a prerequisite for further treatment
Application of design of experiments in developing a sprayable gel formulation for dermal melatonin delivery
No full textMelatonin je neurohormon koji se već dugi niz godina koristi u liječenju nesanice, a novija
istraživanja pokazuju njegov veliki potencijal u liječenju kožnih oboljenja poput atopijskog
dermatitisa, vitiliga i psorijaze. Lokalnom primjenom moguće je ostvariti veću koncentraciju lijeka
na mjestu primjene te smanjiti rizik od sistemskih nuspojava. Gel kao farmaceutski oblik osigurava
dulji kontakt s kožom i bolju (bio)raspoloživost djelatne tvari. Primjena formulacije raspršivanjem
omogućava jednostavnost primjene, obuhvaćanje većih površina te ravnomjernu raspodjelu
sadržaja. Cilj ovog rada bio je razviti gel Carbopola i poletilenglikola (PEG-a) za dermalnu primjenu
melatonina raspršivanjem. Za ispitivanje utjecaja koncentracije Carbopola i PEG-a na ključna
svojstva gela te optimizaciju formulacije, primijenjen je statistički dizajn eksperimenta. Temeljem
opsežne reološke i teksturne karaterizacije te ispitivanja ujednačenosti doziranja, odabrane su
optimalne koncentracije Carbopola i PEG-a (redom 0,1 % i 5 %; m/m) za daljnju karakterizaciju i
uklapanje melatonina. Dodatak melatonina neznatno je utjecao na svojstva formulacije, što ukazuje
na prikladnost razvijenog gela za uklapanje djelatne tvari. Ispitivanjem reoloških i fizičko-kemijskih
svojstava formulacije nakon 30 dana, potvrđena je stabilnost formulacije tijekom skladištenja.
Dobiveni rezultati ukazuju na potencijal razvijenog gela s Carbopolom i PEG-om kao farmaceutskog
oblika za dermalnu primjenu melatonina raspršivanjem.Melatonin is a neurohormone commonly used for the treatment of insomnia. Recent research shows
its great potential in treating skin conditions such as atopic dermatitis, vitiligo, and psoriasis. Topical
application allows for a higher concentration of the drug at the site of application and reduces the
risk of systemic side effects. Gel as a drug delivery system ensures prolonged contact with the skin
and better (bio)availability of the drug. Application of the formulation by spraying allows for ease
of use, coverage of larger areas, and even distribution of the contents.The aim of this work was to
develop a sprayable Carbopol and polyethylene glycol (PEG)-based gel for dermal application of
melatonin. To examine the influence of Carbopol and PEG concentration on key properties of the
gel and to optimize the formulation, a statistical design of experiments was employed. Based on the
extensive rheological and textural characterization and dosing uniformity testing, the optimal
concentrations of Carbopol and PEG (0.1% and 5%, respectively; w/w) were selected for further
characterization and incorporation of melatonin. The addition of melatonin had a negligible effect
on the formulation properties, indicating the suitability of the developed gel for incorporating this
active substance. Examination of the rheological and physicochemical properties of the formulation
after 30 days confirmed the stability of the formulation during storage. The obtained results indicate
the potential of the developed Carbopol/PEG gel as a delivery system for dermal application of
melatonin by spraying
Application of the design of experiments (DOE) method in the optimization of cold forming process parameters for fastener production
No full textOvaj diplomski rad bavi se optimizacijom procesa hladnog oblikovanja dvoglavih čavala u proizvodnji pričvrsnih elemenata, s posebnim naglaskom na fazu pokretanja stroja. Faza pokretanja često uzrokuje povećanu varijabilnost dimenzija i veću stopu otpada, što negativno utječe na učinkovitost i ekonomičnost proizvodnje. Cilj istraživanja je primjenom metode planiranja pokusa (Design of Experiments – DOE) identificirati ključne procesne parametre koji utječu na kvalitetu proizvoda tijekom ove faze te razviti prediktivni model za optimizaciju procesa.
U teorijskom dijelu rada obrađena je tehnologija hladnog oblikovanja metala, s posebnim osvrtom na proizvodnju pričvrsnih elemenata i izazove povezane s fazom pokretanja. Također, detaljno je prikazana metodologija planiranja pokusa (DOE) i njezina primjena u industrijskim procesima za poboljšanje kvalitete i učinkovitosti.
Eksperimentalni dio rada proveden je na stroju za hladno oblikovanje u proizvodnom pogonu. Definirani su relevantni ulazni faktori i izlazne varijable, nakon čega je provedeno planiranje i izvođenje pokusa prema odabranom DOE dizajnu. Prikupljeni podaci analizirani su statističkim metodama, uključujući ANOVA analizu i regresijsko modeliranje, kako bi se identificirali značajni utjecaji i međudjelovanja faktora.
Rezultati istraživanja omogućili su razvoj prediktivnog modela koji precizno opisuje utjecaj procesnih parametara na kvalitetu proizvoda u fazi pokretanja. Na temelju modela predložene su optimalne postavke procesa koje minimaliziraju otpad i osiguravaju stabilnu proizvodnju. Validacija modela provedena je kroz dodatne pokuse, čime je potvrđena njegova učinkovitost i primjenjivost u stvarnim proizvodnim uvjetima.This thesis focuses on the optimization of the cold forming process for double-headed nails in the production of fasteners, with a particular emphasis on the startup phase of the machine. The startup phase often leads to increased dimensional variability and higher scrap rates, which negatively affect the efficiency and cost-effectiveness of production. The objective of this study is to apply the Design of Experiments (DOE) methodology to identify key process parameters that influence product quality during this phase and to develop a predictive model for process optimization.
The theoretical part of the thesis covers the technology of cold metal forming, with a specific focus on fastener production and the challenges associated with the startup phase. Furthermore, the methodology of DOE is thoroughly explained, including its application in industrial processes to improve quality and efficiency.
The experimental work was conducted on a cold forming machine in Plant. Relevant input factors and output variables were defined, followed by the planning and execution of experiments based on the selected DOE design. The collected data were analysed using statistical methods, including ANOVA and regression modelling, to identify significant effects and interactions between factors.
The results of the study enabled the development of a predictive model that accurately describes the influence of process parameters on product quality during startup. Based on the model, optimal process settings were proposed to minimize scrap and ensure stable production. Model validation was carried out through additional trials, confirming its effectiveness and applicability in real manufacturing conditions
Challenges of environmental taxation and ESG legislation : the Danish model of green transition
No full textZelena tranzicija podrazumijeva prijelaz na održivi način poslovanja koji se temelji na smanjenju emisija stakleničkih plinova, zaštiti okoliša i odgovornom korištenju resursa. Tijekom cijelog procesa, fiskalna politika ima ključnu ulogu kroz uvođenje ekoloških poreza, subvencija za zelene investicije i poreznih olakšica za održivo poslovanje. Ističe se sve veći značaj ESG kriterija ( okolišni, društveni i upravljački) koji polako postaju standard pri donošenju financijskih odluka i poslovnih strategija. ESG oporezivanje obuhvaća fiskalne mjere koje su usmjerene na poticanje održivog razvoja poduzeća i kažnjavanje onih koji ih ne poštuju. Ovdje se jača povezanost poreznog sustava s ciljevima održavanja. Porezni instrumenti nisu samo usmjereni na zaštitu okoliša, već i na društvenu pravednost kroz redistribuciju prihoda i ublažavanje negativnih socijalnih učinaka. Primjeri iz EU pokazuju razne pristupe zelenoj fiskalnoj reformi, a uspješnost ovisi o transparentnosti, prilagodbi lokalnim uvjetima odnosno uključenost javnosti i koordinaciji s drugim politikama.The green transition refers to the shift towards sustainable business practices aimed at reducing greenhouse gas emissions, protecting the environment, and responsibly utilizing resources. Throughout this process, fiscal policy plays a pivotal role by introducing ecological taxes, subsidies for green investments, and tax incentives for sustainable business operations. The increasing significance of ESG (Environmental, Social, and Governance) criteria is evident, as they gradually become standard considerations in financial decision-making and business strategies. ESG taxation encompasses fiscal measures designed to promote sustainable development among enterprises and penalize non-compliance, thereby strengthening the alignment of the tax system with sustainability objectives. These tax instruments not only focus on environmental protection but also address social justice through income redistribution and mitigating adverse social impacts. Examples from the EU demonstrate various approaches to green fiscal reform, with success contingent upon transparency, adaptation to local conditions (including public involvement), and coordination with other policies
Skip loader body for communal container
No full textOvaj diplomski rad bavi se razvojem i konstrukcijskom razradom nadogradnje vozila s
nadogradnjom za samoutovar komunalnih kontejnera s mogućnošću pražnjenja tereta na
promjenjivim visinama. Na temelju analize tržišnih rješenja, tehničkih propisa i ograničenja,
definiran je niz funkcionalnih i konstrukcijskih zahtjeva koje je sustav morao zadovoljiti. Kao
osnova odabrano je vozilo Mercedes-Benz New Atego 1530 L, čije tehničke karakteristike
postavljaju granice unutar kojih se oblikuje nadogradnja.
U sklopu rada razrađena su različita konceptualna rješenja, od kojih su tri evaluirana pomoću
višekriterijskog sustava ocjenjivanja temeljenog na tehničkim i funkcionalnim parametrima.
Nakon provedenog vrednovanja, odabran je optimalan koncept koji omogućuje stabilno i
kontrolirano pražnjenje kontejnera na različitim visinama, uz zadržavanje pouzdanosti i
jednostavnosti uporabe.
Konstrukcijska razrada provedena je u programskom paketu SolidWorks, gdje je izrađen
cjeloviti 3D model i pripadajuća tehnička dokumentacija. Proračunati su svi ključni elementi
sustava, uključujući teleskopske ruke, hidrauličke cilindre, spojeve i stabilizatore, a odabir
materijala temeljen je na zahtjevima čvrstoće, otpornosti na habanje i sigurnosti.
Konačno rješenje osigurava mehaničku pouzdanost, stabilnost u radu i prilagodljivost različitim
vrstama kontejnera, čime je ispunjena tehnička svrha nadogradnje u skladu s važećim normama
i pravilnicima.This thesis presents the development and structural design of a skip loader truck body upgrade
with the capability of discharging containers at variable heights. Based on market analysis,
regulatory constraints, and technical requirements, a set of functional and construction-related
criteria was defined to guide the design process. The selected base vehicle is the Mercedes
Benz New Atego 1530 L, whose technical specifications determined the design boundaries of
the upgrade.
Several conceptual solutions were developed, three of which were evaluated using a multi
criteria assessment system based on technical and operational parameters. Following the
evaluation, the optimal concept was selected, one that ensures stable and controlled container
discharge at various heights while maintaining reliability and ease of use.
The structural design was carried out using the SolidWorks software package, where a complete
3D model and accompanying technical documentation were created. All key components were
analyzed, including telescopic arms, hydraulic cylinders, joints, and stabilizers, and material
selection was based on strength, wear resistance, and safety requirements.
The final solution provides mechanical reliability, operational stability, and adaptability to
different container types, thus fulfilling the functional and technical purpose of the upgrade in
accordance with applicable standards and regulations
Influence of the reaction parameters on the biodiesel synthesis from palm oil and selected straight-chain alcohols
No full textKroz posljednjih nekoliko desetljeća znanost se intenzivnije posvetila razvoju biogoriva s ciljem smanjenja onečišćenja okoliša uzrokovanog izgaranjem fosilnih goriva. Isto tako, porast broja svjetske populacije, brza industrijalizacija, urbanizacija, samo su neki od čimbenika koji uzrokuju rastuću potražnju za energijom i time potiču sve veću upotrebu fosilnih goriva. Kako su fosilna goriva neobnovljivi izvori energije, istraživanja su usmjerena na gorivo koje bi potjecalo isključivo od obnovljivih izvora. Kao dobra alternativa pokazao se biodizel zbog svoje ekološki prihvatljive prirode. Dobiva se katalitičkom transesterifikacijom – reakcijom biosirovine (biljnih ulja i životinjskih masti) s alkoholom uz prisutnost katalizatora. Sastavni dio masti i ulja su trigliceridi – esteri alkohola glicerola i viših masnih kiselina koji sudjeluju u reakciji transesterifikacije s alkoholom. Nastaju smjese alkilnih estera masnih kiselina (biodizel) i alkohol glicerol kao sporedni produkt. U ovom je radu biodizel sintetiziran transesterifikacijom iz palminog ulja kao glavne biosirovine te odabranih ravnolančanih alkohola: 1-propanola, 1-butanola, 1-pentanola, 1-heksanola, 1-oktanola uz prisutnost baznog katalizatora - kalijeva hidroksida (KOH), budući da svojstva primjene biodizela ovise o strukturi reaktanata korištenih u sintezi. Praćeni su utjecaji određenih parametara na reakciju sinteze, a to su: reakcijsko vrijeme (5, 15, 60 minuta), temperatura
(60 °C), molarni omjer alkohola i ulja (5:1 i 10:1) i maseni udio katalizatora (1 mas.% KOH i 3 mas.% KOH). Osim utjecaja navedenih parametara, praćen je i utjecaj molekulske mase alkohola na iskorištenje reakcije. S obzirom na navedene alkohole, u reakciji sinteze biodizela nastaju propilni, butilni, pentilni, heksilni i oktilni esteri masnih kiselina. Dobiveni rezultati pokazuju da reakcijsko vrijeme ima vrlo malo ili nimalo utjecaja na iskorištenje. Povećanje masenog udjela katalizatora i molarnog omjera alkohola i ulja generalno dovodi do većeg iskorištenja sinteze biodizela. S povećanjem molekulske mase alkohola pada polaritet alkohola, a u konačnici i alkoksidnog aniona koji ima glavnu ulogu u mehanizmu bazne transesterifikacije. Padom polariteta alkoksidnog aniona pada i njegov afinitet prema esterskoj skupini triglicerida i time se iskorištenje reakcije smanjuje.Over the past few decades, science has devoted itself more intensively to the development of biofuels with the aim of reducing environmental pollution caused by the burning of fossil fuels. Likewise, the increase in the number of the world's population, rapid industrialization, urbanization, are just some of the factors that cause the growing demand for energy and thus encourage the ever-increasing use of fossil fuels. As fossil fuels are non-renewable sources of energy, researches aimed for fuel that would come exclusively from renewable sources. Biodiesel proved to be a good alternative due to its environmentally friendly nature. It is obtained by catalytic transesterification - the reaction of feedstocks (vegetable oils and animal fats) with an alcohol in the presence of a catalyst. An integral part of fats and oils are triglycerides - esters of glycerol and fatty acids that participate in the transesterification reaction with an alcohol. Therefore, fatty acid alkyl esters (biodiesel) and also alcohol glycerol as a by-product are produced. In this work, biodiesel was synthesized by base – catalyzed transesterification from palm oil as the main feedstock and selected straight-chain alcohols: 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-octanol, in the presence of a base catalyst - potassium hydroxide (KOH), since the application properties of biodiesel depend on the structure of the reactants used in the synthesis. The effects of certain parameters on the synthesis reaction were monitored: reaction time (5, 15, 60 minutes), temperature
(60 °C), molar ratio of alcohol and oil (5:1 and 10:1) and mass fraction of catalyst
(1 wt.% KOH and 3 wt.% KOH). In addition to the influence of the mentioned parameters, the influence of the molecular weight of alcohol on the reaction conversion was investigated, as well. With regard to the mentioned alcohols in the biodiesel synthesis reaction, fatty acid propyl, butyl, pentyl, hexyl and octyl esters were produced. The obtained results show that the reaction time has very little or no influence on the reaction conversion. Increasing the mass fraction of the catalyst and the molar ratio of alcohol to oil generally leads to a higher reaction conversion. As the molecular weight of the alcohol increases, the polarity of the alcohol decreases, and ultimately of the alkoxide anion, which plays a major role in the base transesterification mechanism. As the polarity of the alkoxide anion decreases, its affinity towards the ester group of triglycerides also decreases, and thus the conversion of the reaction decreases
Suspension compliance measuring device for Formula Student race car
No full textProblemi s elastičnim deformacijama ovjesa su uočeni na stazi prilikom testiranja. Pretpostavke su da se najveće deformacije događaju na naplatku, ali su to samo pretpostavke. Cilj uređaja za mjerenje elastokinematike ovjesa je prikupiti što više korisnih podataka koji se primarno tiču promjene kutova bočnog nagiba kotača te usmjerenosti kotača.
U ovom radu je napravljena analiza problema koji uzrokuju deformacije ovjesa, predstavljena su trenutna rješenja na tržištu te je napravljeno predstavljanje mogućih rješenja. Nakon toga je konstrukcijski razrađeno optimalno rješenje za trenutne potrebe FSB Racing Teama, to rješenje je detaljno predstavljeno te popraćeno troškovnikom i tehničkom dokumentacijom.Problems with elastic deformations of the suspension were observed on the track during testing. It is assumed that the greatest deformations occur on the wheel rim, but these are only assumptions. The goal of the suspension compliance measurement device is to collect as much useful data as possible, primarily concerning changes in the wheel's camber and toe angles.
This paper analyzes the problems causing suspension deformations, presents existing solutions available on the market, and introduces potential solutions. Following this, an optimal solution for the current needs of the FSB Racing Team was developed in detail, presented comprehensively, and supported with a cost analysis and technical documentation
Optimization and validation of HPLC method for the simultaneous determination of prednisolone derivatives
No full textGlukokortikoidi su skupina lijekova koji se sve češće primjenjuju u suvremenoj medicinskoj praksi zbog svojih izraženih
protuupalnih i imunosupresivnih svojstava. Koriste se u liječenju širokog spektra upalnih bolesti, uključujući astmu,
upalne bolesti crijeva, alergije te različite bolesti oka. Ipak, njihova dugotrajna primjena povezana je s ozbiljnim
nuspojavama kao što su Cushingov sindrom, neurološke smetnje, glaukom i srčano zatajenje, što ističe potrebu za
razvojem pouzdanih analitičkih metoda za njihovo ispitivanje.
U ovom radu analizirani su su prednizolon fosfat i prednizolon acetat, a cilj je bio razviti i validirati HPLC metodu
sukladno ICH Q2(R2) smjernicama, te kvantificirati njihov sadržaj u prahu djelatne tvari i model uzorku. Primjenom
HPLC-DAD metode sa gradijentnom elucijom postignuto je učinkovito razdvajanje analita pri temperaturi od 50 °C i
valnoj duljini od 254 nm. Metoda je zadovoljila sve zahtjeve validacijskih parametara. Dobiveni rezultati pokazali su da
je sadržaj oba analita u ispitivanim uzorcima unutar propisanih granica prema važećim farmakopejskim standardima.Glucocorticoids are a group of drugs increasingly used in modern medical practice due to their pronounced antiinflammatory and immunosuppressive properties. They are used in the treatment of a wide range of inflammatory
diseases, including asthma, inflammatory bowel diseases, allergies, and various ocular conditions. However, their longterm use is associated with serious side effects such as Cushing's syndrome, neurological disorders, glaucoma, and heart
failure, highlighting the need for the development of reliable analytical methods for their examination.
In this study, prednisolone phosphate and prednisolone acetate were analyzed, with the aim of developing and validating
an HPLC method in accordance with ICH Q2(R2) guidelines and quantifying their content in the active pharmaceutical
ingredient powder and a model sample. By applying the HPLC-DAD method with gradient elution, effective separation
of the analytes was achieved at a temperature of 50°C and a wavelength of 254 nm. The method met all validation
parameter requirements. The obtained results showed that the content of both analytes in the tested samples was within
the prescribed limits according to current pharmacopoeial standards
Characterization methods for in situ forming hydrogels applied in extended release drug delivery systems
No full textHidrogelovi su hidrofilne, trodimenzionalne polimerne mreže koje mogu apsorbirati velike količine vode ili bioloških tekućina. Zbog visokog sadržaja vode i fizikalno-kemijske sličnosti s izvanstaničnim matriksom, ovi materijali posjeduju svojstva poput bubrenja i odlikuju se izrazitom biokompatibilnošću. U ovom radu, fokus je na poli(laktid-ko-glikolid) (PLGA) polimerima, koji su biorazgradivi i biokompatibilni kopolimeri mliječne i glikolne kiseline, široko prihvaćeni u farmaceutskim i medicinskim proizvodima. PLGA hidrogelovi su jedni od kandidata za primjenu u sustavima za dostavu lijeka s produljenim oslobađanjem u farmaceutskoj industriji. Cilj ovog završnog rada bio je istražiti metode karakterizacije in situ formiranih hidrogelova na osnovi PLGA polimera. Eksperimentalni dio obuhvaća pripravu hidrogelova koristeći polimerne otopine PLGA kopolimera s različitim molnim omjerom laktida (LA) i glikolida (GA) (LA:GA = 85:15 i 50:50) koristeći dimetil sulfoksid (DMSO) i N-metil pirolidon (NMP) kao biokompatibilna otapala u vodenom mediju (fosfatnom puferu). Provedena je karakterizacija formiranih hidrogelova kroz vrijeme gravimetrijskim testom praćenja promjene mase (bubrenje i fizikalna stabilnost), kinetike izlaska otapala tekućinskom kromatografijom visoke djelotvornosti (HPLC), promjene molekulskih masa polimera uslijed hidrolitičke razgradnje gel permeacijskom kromatografijom (GPC metodom) te morfološka ispitivanja pretražnim elektronskim mikroskopom (ESEM). Iz rezultata provedenih mjerenja vidljivo je kontinuirano smanjenje mase formiranih hidrogelova tijekom 14 dana s najvećim padom u prva 24 sata. Gravimetrijski je pokazano da se polimerima s manjim udjelom laktida masa brže smanjuje u odnosu na polimere s većim LA:GA omjerom. HPLC analiza potvrdila je izlazak DMSO otapala iz hidrogelova unutar prva 4 sata. GPC analiza pokazala je kemijsku razgradnju PLGA polimera kroz vrijeme, pri čemu se PLGA polimer s LA:GA omjerom 50:50 brže razgrađivao u odnosu na PLGA polimer s 85:15 omjerom. ESEM ispitivanja ukazala su na neke morfološke razlike između formiranih PLGA hidrogelova s obzirom na sastav polimera i vrstu otapala.Hydrogels are hydrophilic, three-dimensional polymer networks that can absorb large amounts of water or biological fluids. Due to their high water content and physicochemical similarity to the extracellular matrix, these materials possess properties such as swelling and are characterized by excellent biocompatibility. In this paper, the focus is on poly(lactide-co-glycolide) (PLGA) polymers, which are biodegradable and biocompatible copolymers of lactic and glycolic acids, widely accepted in pharmaceutical and medical products. PLGA hydrogels are one of the candidates for application in sustained-release drug delivery systems in the pharmaceutical industry. The aim of this thesis was to investigate methods for the characterization of in situ formed hydrogels based on PLGA polymers. The experimental part includes the preparation of hydrogels using polymer solutions of PLGA copolymers with different molar ratios of lactide (LA) and glycolide (GA) (LA:GA = 85:15 and 50:50) using dimethyl sulfoxide (DMSO) and N-methyl pyrrolidone (NMP) as biocompatible solvents in an aqueous medium (phosphate buffer). The formed hydrogels were characterized over time by gravimetric tests monitoring mass changes (swelling and physical stability), solvent release kinetics by high-performance liquid chromatography (HPLC), changes in polymer molecular weights due to hydrolytic degradation by gel permeation chromatography (GPC), and morphological examinations by scanning electron microscopy (ESEM). The results of the measurements showed a continuous decrease in the mass of the formed hydrogels over 14 days, with the largest decrease in the first 24 hours. Gravimetrically, it was shown that the polymer composition (LA:GA ratio) has a greater influence on the mass reduction than the type of solvent (DMSO and NMP). HPLC analysis confirmed the release of DMSO solvent from the hydrogels within the first 4 hours. GPC analysis showed chemical degradation of PLGA polymers over time, with the PLGA polymer with a LA:GA ratio of 50:50 degrading faster than the PLGA polymer with a ratio of 85:15. ESEM examinations indicated some morphological differences between the formed PLGA hydrogels with respect to on the polymer composition and the type of solvent