Templating Novel Thermotropic Liquid Crystal Phases

Templating is a bottom-up approach used in materials science, whereby intricate nanoscale features of a ‘host’ medium are transferred onto a ‘guest’ matrix through a series of chemical and physical mechanisms. The past few decades have seen a great deal of research on the topic of templating lyotropic liquid crystal phases, mainly for biomedical applications. More recently, thermotropic liquid crystal templating has also sparked research interests, particularly the cholesteric and blue phases, for their applications in tuneable photonic structures. With thermotropic liquid crystal templating being a relatively recent field of research, little is known about the nanoscopic interactions between host liquid crystals and guest polymers that result in the templating effect. This thesis aims to gain a better understanding of how templates are created through the process of surface modification of polymers and which properties of the host liquid crystal can be templated. Two novel thermotropic mesophases were templated for the first time, namely the twist-bend nematic (NTB) phase and the ferroelectric SmA (SmAPF) phase. The host liquid crystal used to template the NTB phase was a mixture of the dimer CB7CB with the calamitic liquid crystal 5CB. Refilling the NTB template with a nematic mesogen allowed for a better understanding of the electrical and mechanical properties of the NTB phase. A carbosilane-tethered bent-core mesogen exhibiting the SmAPF phase was synthesised by adapting procedures available in literature, and this mesogen was used for templating the SmAPF phase. Refilling the SmAPF template enabled an insight into which properties of the host mesophase can be templated, such as the layered structure, biaxiality and ferroelectric switching. Samples composed of a monomer and host liquid crystal were thermodynamically-stabilised (photopolymerised) and metastable room temperature NTB phases were formed using this process. All photopolymerised phases showed similar thermal and dielectric properties to the pure host liquid crystals. Residual birefringence was observed in the polymer networks of all polymerised phases when the liquid crystal was in the isotropic state. Templates were created by washing the host liquid crystal from the polymer matrix. Raman spectroscopy was used for the first time to confirm that the templates were not contaminated with unwashed host liquid crystal. Visualisation of the templates using SEM revealed a clear difference between the template morphologies formed from different host liquid crystals, whereby the general mesoscopic structure of the host mesophase had been templated. The thermal and dielectric properties of the refilled templates showed that order was being induced in the refilled liquid crystal. The distinction between physical properties of the refilled templates and pure 5CB was especially clear in measurements of permittivity and threshold electric fields. For NTB templates, it was suggested that the nanofeatures of the NTB phase had been templated. The field of thermotropic liquid crystal templating is still in its infancy, yet it offers a great deal of potential in understanding the elegant interplay of chemical and physical processes in soft matter systems at the nanoscopic scale

Modal Hedges in Para-pharmaceutical Product Instructions: Some Examples from English and Serbian

The paper investigates how modal hedges (Coates 1983) understood as expressions of procedural meaning, i.e. expressions which instruct the addressee/reader how to process the propositional content of an utterance/statement (Watts 2004) are used in product descriptions, advertisements and consumer instructions leaflets for a number of products belonging to the Consumer Health Care category for the purposes of complying with consumer protection laws on the one hand and serving as an implicit disclaimer of manufacturer’s responsibility on the other. The analysis is carried out contrastively for two languages, English and Serbian. The results obtained are discussed and viewed as a matter of cultural variety and difference, especially taking into consideration the fact that consumer protection laws seem to be equally strict in US, UK and Commonwealth, Europe and Serbia.

IN SILICO EVALUATION OF ANGIOTENSIN II RECEPTOR ANTAGONIST’S PLASMA PROTEIN BINDING USING COMPUTED MOLECULAR DESCRIPTORS

The discovery of new pharmacologically active substances and drugs modeling led to necessity of predicting drugs properties and its ADME data. Angiotensin II receptor antagonists are a group of pharmaceuticals which modulate the renin-angiotensin-aldosterone system and today represent the most commonly prescribed anti-hypertensive drugs. The aim of this study was to compare different molecular properties of seven angiotensin II receptor antagonists / blockers (ARBs), (eprosartan, irbesartan, losartan, olmesartan, telmisartan, valsartan) and their plasma protein binding (PPB) data. Several ARBs molecular descriptors were calculated using software package Molinspiration Depiction Software as well as Virtual Computational Chemistry Laboratory (electronic descriptor – PSA, constitutional parameter – Mw, geometric descriptor – Vol, lipophilicity descriptors - logP values, aqueous solubility data – logS). The correlations between all collected descriptors and plasma protein binding data obtained from relevant literature were established. In the simple linear regression poor correlations were obtained in relationships between PPB data and all calculated molecular descriptors. In the next stage of the study multiple linear regression (MLR) was used for correlation of PPB data with two different descriptors as independent variables. The best correlation (R2=0.70 with P<0.05) was established between PPB data and molecular weight with addition of volume values as independent variables. The possible application of computed molecular descriptors in drugs protein binding evaluation can be of great importance in drug research

Prikazi knjiga

John C. Pollock and Douglas A. Vakoch (editors) COVID-19 IN INTERNATIONAL MEDIA: GLOBAL PANDEMIC PERSPECTIVES London: Routledge, 2022, 267 pp Richard M. Perloff THE DYNAMICS OF NEWS: JOURNALISM IN THE 21ST-CENTURY MEDIA MILIEU New York: Routledge, 2020John C. Pollock and Douglas A. Vakoch (editors) COVID-19 IN INTERNATIONAL MEDIA: GLOBAL PANDEMIC PERSPECTIVES London: Routledge, 2022, 267 pp Richard M. Perloff THE DYNAMICS OF NEWS: JOURNALISM IN THE 21ST-CENTURY MEDIA MILIEU New York: Routledge, 202

Myasthenia gravis patients with anti-MuSK antibodies [Miastenija gravis kod bolesnika s pozitivnim protutijelima na MuSK]

In myasthenia gravis (MG) patients without detectable anti-acetylcholine receptor (anti-AChR) antibody, referred to as seronegative myasthenia gravis patients, there is a variable proportion of patients with antibodies against the muscle specific kinase (MuSK). MuSK antibodies were found in 8 (29.6%) of our 27 patients with generalized MG without anti-AChR antibodies. All these patients were female. The age at the onset ranged from 22 to 38 years. All patients had ocular and bulbar symptoms, and two patients also had generalized limb weakness. Two patients had pure ocular symptoms for 7 or 8 years before the development of bulbar symptoms. All anti-MuSK positive patients were treated with immunosuppressive drugs, three received plasmapheresis and one patient required mechanical ventilation. Our results are consistent with other literature reports

CORRELATION BETWEEN ANGIOTENSIN-CONVERTING ENZYME INHIBITORS LIPOPHILICITY AND PROTEIN BINDING DATA

Angiotensin-converting enzyme (ACE) inhibitors represent a significant group of drugs primarily used in the treatment of hypertension and congestive heart failure. In this research, seven ACE inhibitors (enalapril, quinapril, fosinopril, lisinopril, cilazapril, ramipril, benazepril) were studied to evaluate the relationship between their protein binding and calculated (logP values) or ultra-high performance liquid chromatographytandem mass spectrometry (UHPLC-MS) and reversed-phase thin-layer chromatography (RP-TLC) lipophilicity data (ϕ0, CHI or C0 parameters, respectively). Their protein binding data varied from negligible (lisinopril) to 99% (fosinopril), while calculated logPKOWWINvalues ranged from -0.94 (lisinopril) to 6.61 (fosinopril). The good correlations were established between protein binding values and logPKOWWIN data (R2=0.7520) as well as between protein binding and chromatographic hydrophobicity data, ϕ0, CHI or C0parameters (R2 were 0.6160, 0.6242 and 0.6547, respectively). The possible application of hydrophobicity data in drugs protein binding evaluation can be of great importance in drug bioavailability

DESCRIPTION FOR ANALYSING AND MODEL OF NOISE REDUCTION IN THE TURBINE FACILITY OF HYDROELECTRIC POWER PLANT

Buka u hidroelektranama izravno utječe na zaposlenike ako je njezin intenzitet iznad dopuštenih, zakonom propisanih granica. U ovom radu prikazan je model rješavanja problema buke u postrojenju hidroelektrane.The noise in hydroelectric power plants directly affects the employees if its intensity is higher than permitted values, according to the legal regulations. This paper provides the description of a model for solving the problem of noise reduction in one hydroelectric power plant

RE-EVALUACIJA I NOVI PRISTUPI U ANALIZI MIGRACIONE POLITIKE U EVROPI

Migration policy is one of the most significant fields for analysis of contemporary population movements and their societal implications. In this paper some of the most important theoretical approaches to migration policy are shown, as well as their benefits and shortcomings, presented in comparative perspective. The special attention is given to the problem of contemporary demographic tendencies in Europe, with special emphasis on many causes of migration movements. At the end of the paper, some of the possible new directions in forming migration policy in Europe are presented, as well as the strategical solutions for (violent) migration problem.Migraciona politika predstavlja jednu od najznačajnijih oblasti analize savremenih populacionih kretanja i njihovih društvenih implikacija. U ovom radu prikazani su vodeći teorijski pristupi u oblasti analize migracione politike, kao i prednosti i nedostaci navedenih pristupa u komparativnoj perspektivi. Posebna pažnja posvećena je analizi savremenih demografskih tendencija na tlu Evrope, sa posebnim fokusom na sagledavanje brojnih činilaca koji uslovljavaju migraciona kretanja. Na kraju, razmotreni su mogući novi pravci u formiranju migracione politike u Evropi, kao i strategijske osnove rešavanja problema (nasilnih) migracija

The influence of pectinase addition during blackberry maceration on physico-chemical quality parameters of blackberry wines

Kupinovo vino je vodno vino dobiveno alkoholnom fermentacijom soka ili masulja svježe kupine. Zbog svog nutritivnog sastava ima blagotvoran utjecaj na ljudsko zdravlje. Tijekom procesa proizvodnje kupinova vina često se koriste komercijalni enzimski pripravci kako bi se dobio proizvod što bolje kakvoće. Cilj ovog rada bio je istražiti utjecaj dodatka enzima pektinaze tijekom maceracije kupine na fizikalno-kemijske pokazatelje kakvoće kupinovih vina. Provedena je alkoholna fermentacija masulja kupine, pri čemu su dvije fermentacije provedene bez dodatka enzima tijekom maceracije te dvije fermentacije s dodatkom enzima pektinaze tijekom maceracije ploda kupine. U gotovim vinima, nakon dozrijevanja, provedene su fizikalno-kemijske analize kakvoće vina te određivanje boje. Rezultati istraživanja pokazali su kako je u vinu proizvedenom uz dodatak pektinaze tijekom maceracije postignuto veće iskorištenje sirovine, veći početni udjel suhe tvari u soku, veća relativna gustoća, ukupni suhi ekstrakt i udjel pepela, u odnosu na vino proizvedeno bez dodatka enzima (kontrola). Nadalje, veća koncentracija ukupnih polifenola te posljedično veće vrijednosti intenziteta boje i tona dobivene za vino proizvedeno uz dodatak enzima u odnosu na kontrolu ukazuju na bolju ekstrakciju tvari boje tijekom maceracije.Blackberry wine is a fruit wine produced by alcoholic fermentation of raw blackberry juice or must. Because of its nutritional composition it has a beneficial effect on human health. In order to obtain the high quality product, the commercial enzyme preparations are often used during the blackberry wine production process. The aim of this work was to investigate the influence of pectinase addition during maceration of blackberries on physico-chemical quality parameters of blackberry wines. Fermentation of blackberry must was carried out in a way that two fermentations were carried out without the enzyme addition during maceration and two were carried out with the pectinase addition during maceration. After wine maturation, the finished wines were analysed for physico-chemical quality parameters as well as colour parameters. The results showed that compared to wine produced without the pectinase addition during maceration (control), the wine produced with the addition of pectinase had higher raw material utilization efficiency, higher initial dry matter content in juice after maceration and higher relative density, total dry extract and ash. Furthermore, higher concentration of total polyphenols and subsequently higher colour intensity and hue of blackberry wine produced with the addition of pectinase compared to control indicate better extraction of colour components during maceration