Preparation of NiO supported carbon paste electrode for sensitive and selective determination of Gallic acid in plant samples

In this work, nickel oxide (NiO) nanoparticles were synthesized by the chemical coprecipitation method and used for modification of the carbon paste electrode for GA detection and determination. Morphological properties of prepared material were investigated using ICP-OES (inductively coupled plasma–optical emission spectrometry), XRD (X-ray diffraction), SEM and TEM (Scanning and Transmission Electron Microscopy). The electrochemical properties of the prepared electrode and the behavior of GA over the modified electrode were examined using CV (Cyclic Voltammetry), EIS (Electrochemical impedance spectroscopy), and SWV (Square Wave Voltammetry)

Fabrication of bismuth-oxychloride supported carbon paste electrode for sensitive Quinine sensing

Quinine is a natural white crystalline cinchona alkaloid that belongs to the aryl amino alcohol group of drugs, and it has antipyretic (fever reducing), antimalarial, analgesic, anti-inflammatory properties and a bitter taste. Today, quinine is considered as the best antimalarial drug since it is chiefly used in the treatment of falciparum malaria resistant to other antimalarials. Quinine is preferred where the disease has become highly resistant to other antimalarial drugs [1]. Quinine has a low therapeutic index, and it is potentially toxic and causes several side effects including nausea, blurred vision, diarrhea, abdominal pain, headache, fever, renal failure and asthma [2]. Since quinine is widely used as a bittering agent in tonic type drinks, a sensitive and discriminatory system for the discovery of quinine is essential for human health. In this work, a modified bismuth-oxychloride (BiOCl) carbon paste electrode was prepared for the detection of quinine. BiOCl nanoparticles were synthesized by the chemical coprecipitation method. The electrochemical properties of quinine at this electrode were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and differential pulse voltammetry (DPV). In addition, electrochemical impedance spectroscopy (EIS), inductively coupled plasma–optical emission spectrometry (ICP-OES), transmission and scanning electron microscopy (TEM and SEM) and X-ray diffraction (XRD) were used to characterize the synthesized materials. The prepared electrode showed better electrocatalytic response than the bare carbon paste electrode. After square wave voltammetry (SWV) optimization, the electrode showed a wide linear working range from 20 to 200 μM at pH 6 of Britton–Robinson buffer solution (BRBS) as the supporting electrolyte. The excellent selectivity of the proposed method, with good repeatability and reproducibility, strongly suggests a potential application of the method for the determination of quinine in pharmaceuticals. The practicality with good recoveries indicates that the morphology of the materials is closely related to other parameters, which in turn suggests that the developed approach can provide a cost effective, rapid, selective, and sensitive method for quinine monitoring

Lipid nanocarriers for advanced skin delivery of fluocinolone acetonide: formulation development, physicochemical and biopharmaceutical characterization

Увод: Лечење болести које захватају фоликуле длаке (нпр. alopecia areata) је велики изазов. Бројна истраживања усмерена су ка развоју липидних наноносача за побољшање односа користи и ризика примене топикалних кортикостероида. Циљ: Циљ овог рада је био да се, варирањем различитих формулационих и процесних параметара, развију стабилни липидни наноносачи за побољшану/унапређену испоруку флуоцинолонацетонида, као модел лековите супстанце из групе користикостероида, у/кроз кожу. Материјал и методе: Одабране формулације окарактерисане су у погледу величине капи/честица и дистрибуције капи/честица по величини (PDI), зета потенцијала (ЗП), pH вредности и електричне проводљивости. Применом in vitro метода за испитивање ослобађања/пермеације кроз вештачку поликарбонатну мембрану/топлотом изоловани епидермис коже уха свиње, процењен је значај примене липидних наноносачa за испоруку флуоцинолонацетонида у кожу, у поређењу са комерцијално доступним препаратом (Синодерм® крем, Галеника, Србија). Резултати и дискусија: Резултати спроведених истраживања су показали да се успешно могу израдити наноемулзије флуоцинолонацетонида задовољавајућих физичко-хемијских карактеристика (величина капи -30 mV, pH вредност ~ 4,1) и дугорочне стабилности током годину дана чувања на собној температури. Иако су иницијално поседовали задовољавајуће физичко-хемијске карактеристике, развијени наноструктурирани липидни носачи са флуоцинолонацетонидом гелирали су већ током три месеца чувања на собној температури, што указује на неадекватну стабилност ових система. Резултати добијени in vitro испитивањем ослобађања/пермеације кроз вештачку поликарбонатну мембрану/кожу уха свиње указали су на супериорност развијених липидних носача (превасходно наноемулзије са 10% уљане фазе) у погледу испоруке флуоцинолонацетонида кроз кожу у поређењу са Синодерм® кремом као референтним узорком. Закључак: Наноемулзије израђене са 10% уљане фазе (смеша триглицерида средње дужине ланца и олеинске киселине) и стабилизоване смешом лецитина и полисорбата 80 представљају обећавајућу стратегију за побољшану испоруку флуоцинолонацетонида у кожу.Introduction: Treatment of skin diseases affecting the hair follicles (e.g., alopecia areata) is still a challenging task. Numerous studies have been focused on the development of various lipid nanocarriers to improve benefit-risk ratio of topical corticosteroids. The Aim: This study aimed to develop physically stable lipid nanocarriers for improved/advanced skin delivery of fluocinolone acetonide, as a model of drug, by varying different formulation and process parameters. Material and Methods: The selected formulations were analyzed in terms of droplet/particle size (Z-ave), size distribution (PDI), zeta potential (ZP), pH value and electrical conductivity. In vitro release/permeation tests with synthetic polycarbonante membranes/heat-separated porcine ear epidermis were employed to estimate the usefulness of applying advanced lipid nanocarriers for fluocinolone acetonide delivery into/trough the skin, compared to commercially available topical product (Sinoderm® cream, Galenika, Serbia). Results: The obtained results showed that is possible to develop nanoemulsions with satisfying physicochemical properties (droplet size -30 mV, pH value ~ 4.1) and long-term stability (during one year of storage at room temperature). Although developed nanostructured lipid carriers initially had satisfying physicochemical characteristics, a gelling was observed during three months at room temperature, indicating inadequate stability of these systems. The results obtained by in vitro release/permeation tests with synthetic polycarbonate membranes/heat-separated porcine ear epidermis showed the superiority of the developed nanocarriers (particularly nanoemulsion with 10% of oil phase) regarding the fluocinolone acetonide delivery through the skin compared to Sinoderm® cream as reference. Conclusion: Nanoemulsions prepared with 10% of oil phase (medium chain triglycerides and oleic acid) and lecithin/polysorbate 80 as stabilizer mixture are the promising strategy for improved delivery of fluocinolone acetonide into the skin

Fluocinolone acetonide nanosuspensions for skin delivery: influence of formulation and process parameters on physicochemical characteristics and in vitro performance

Увод: Захваљујући низу јединствених особина, наносуспензије представљају обећавајућу стратегију за дермалну испоруку у води слабо растворљивих лековитих супстанци. Међутим, упркос бројним истраживачким напорима, развој наносуспензија је прилично изазован задатак. Услед велике специфичне површине, као и велике површинске енергије, нанокристали су склони агрегацији током чувања, што може негативно да утиче како на перформансе тако и безбедност примене наносуспензија. Циљ рада: Циљ овог рада је био да се варирањем одговарајућих формулационих и процесних параметара развију стабилне наносуспензије за дермалну испоруку флуоцинолонацетонида као модел лековите супстанце. Материјал и методе: Наносуспензије су припремљене применом topdown методе уситњавања у течном медијуму варирањем типа и удела стабилизатора, као и одговарајућих процесних параметара (садржај медијума за уситњавање и време трајања процеса уситњавања). Одабране формулације су окарактерисане у погледу величине честица, полидисперзног индекса (PDI), зета потенцијала и pH вредности. Применом in vitro метода за испитивање ослобађања/пермеације кроз вештачку поликарбонатну мембрану/топлотом изоловани епидермис коже уха свиње процењен је значај примене наносуспензије у поређењу са конвенционалним, комерцијално доступним препаратом за примену на кожи (Синодерм® крем, Галеника, Србија). Резултати: Најмање вредности величине честица (<250 nm) и расподеле величине честица (PDI<0,3), уочене су код формулације стабилизоване са 0,0125% полисорбата 80, како иницијално, тако и након 2 недеље чувања на собној температури и у фрижидеру. Спроведена in vitro испитивања ослобађања/пермеације указала су на супериорност отпималне наносуспензије у погледу испоруке флуоцинолонацетонида кроз кожу у поређењу са формулацијом угушћеном применом ксантан гуме, као и референтним узорком (Синодерм® крем). Закључак: Наносуспензије израђене применом полисорбата 80 (0,0125%) као стабилизатора представљају обећавајућу формулацију за побољшану испоруку флуоцинолонацетонида у кожу. Додатна испитивања су неопходна како би се проценила дугорочна стабилност развијене формулације, као и њен терапијски значај.Introduction: Owing to numerous appealing properties, nanosuspensions represent a promising strategy for dermal delivery of poorly water soluble drugs. However, despite the considerable research efforts, development of nanosuspensions is a still challenging task. Due to large surface area and high surface energy, nanocrystal particles are prone to aggregate during storage, which can compromise both nanosuspension performance and safety. The Aim: This study aimed to develop physically stable nanosuspensions for dermal delivery of fluocinolone acetonide as a model drug, by varying different formulation and process parameters. Material and Methods: Nanosuspensions were prepared by modified wet ball milling technique, by varying type/ratio of stabilizer and corresponding process parameters (content of milling medium and milling duration). The selected formulations were analyzed in terms of particle size (Z-Ave) and size distribution (PDI), zeta potential (ZP), and pH value. In vitro release/permeation tests with synthetic polycarbonate membranes/heat-separated porcine ear epidermis were employed to estimate the usefulness of applying nanosuspensions for fluocinolone acetonide delivery into/trough the skin, compared to the conventional, commercially available topical product (Sinoderm® cream, Galenika, Serbia). Results: The smallest particle size (<250 nm) and particle size distributions (PDI<0.3) were observed for nanosuspension stabilized with 0.0125% оf polysorbate 80, both initially and after 2 weeks of storage at room temperature and in a refrigerator. The results obtained by in vitro release/permeation tests with synthetic polycarbonate membranes/heat-separated porcine ear epidermis showed the superiority of the optimal nanosuspension regarding the fluocinolone acetonide delivery through the skin compared to nanosuspension thickened by xanthan gum and Sinoderm® cream as reference. Conclusion: Nanosuspensions prepared with polysorbate 80 (0.0125%) as stabilizer represent a promising formulation for improved delivery of fluocinolone acetonide into/through the skin. Additional studies are needed to assess the long-term stability of the developed formulation, as well as its therapeutic usefulness

Winter destinations hotels performance measurement practice - evidence from CEE

This study offers insight into the performance measurement practice of winter destination hotels in Bosnia. The research was conducted through face-to-face interviews with hotel owners, managing directors and managers. In the metrics measurement structure, financial metrics dominate, but hotels use non-financial metrics to a significant extent as well. The results point to the existence of differences in performance measurement of hotels of different income and sales growth. Moreover, the research highlights that managers mostly assess the usefulness of both organizational and operational metrics as above average. Unlike performance measurement, the managers’ attitudes differ only with hotels of different sales growth

Fabrication of bismuth-oxychloride supported carbon paste electrode for sensitive and selective Quinine sensing

In this work, a modified bismuth-oxychloride (BiOCl) carbon paste electrode was prepared for the detection of quinine. BiOCl nanoparticles were synthesized by the chemical coprecipitation method. The electrochemical properties of quinine at this electrode were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV), and differential pulse voltammetry (DPV). In addition, electrochemical impedance spectroscopy (EIS), inductively coupled plasma–optical emission spectrometry (ICP-OES), transmission and scanning electron microscopy (TEM and SEM) and X-ray diffraction (XRD) were used to characterize the synthesized materials. The prepared electrode showed better electrocatalytic response than the bare carbon paste electrode

Elektrohemijsko određivanje nitrita u uzorcima vode primenom elektrode od ugljenične paste modifikovane Ni/Bi oksidom

U ovom istraživanju, sintetisani su kompozitni nanomaterijali koji su korišćeni za modifikaciju elektrode od ugljenične paste. Materijali su sintetisani metodom koprecipitacije, a korišćene su soli nikla i bizmuta. Morfološke karakteristike materijala su ispitane skenirajućom i transmisionom elektronskom mikroskopijom i rendgenskom strukturnom analizom. Na osnovu ciklične voltametrije i elektrohemijske impedanse modifikovana elektroda pokazuje bolje elektrokatalitičke osobine od nemodifikovane elektrode

Die ostkeltischen spätlatènezeitlichen Wagengräber im Burgmuseum Deutschlandsberg und aus Hrtkovci–Vukoder in Syrmien

Eines der Phänomene der kontinentalen Eisenzeit ist der Brauch, die Elite nach mediterranem Vorbild mit zwei- oder vierrädrigen Wagen zu bestatten. Die Beigabe eines Wagens ist vor allem dann gut erkennbar, wenn die Wagen mit Elementen aus Metall, ob technische Elemente oder Zierteile, versehen waren. Innerhalb der Spätlatènezivilisation kommen Bestattungen mit vierrädrigem Wagen nur vereinzelt vor. Der elitäre Tote bzw. vornehme Krieger wurde auf den Kasten des vierrädrigen Wagens gelegt und samt Waffen und beigelegtem Trink- und Speiseservice am Scheiterhaufen verbrannt. Neben verschiedenen eisernen Wagenelementen wird an dieser Stelle auch ins Grab beigelegtes Herdgerät besprochen. Den weit verstreuten Gräbern mit vierrädrigem Wagen sind unter anderem technische Details zum Wagenbau, das Pferdegeschirr und die häufige Beigabe von italischem Bronzegeschirr gemeinsam. Wie es zu diesem Bestattungsphänomen innerhalb der weit entfernten Gebiete gekommen ist, muss offenbleiben. Der Fund aus Hrtkovci-Vukoder ist eindeutig mit der nächstgelegenen keltischen Siedlung der Skordisker auf der Gomolava zu verbinden. Für die östliche Herkunft des Bestatteten aus dem Wagengrab im Burgmuseum Archeo Norico Deutschlandsberg sprechen die Eisenfibel vom Typ Gura Padinii und das Girlandenmuster auf den Eisenplatten

Utvrđivanje faktora virulentnosti Exserohilum turcicum u Srbiji

The determination of Exserohilum turcicum virulence factors and resistance responses of three sets of maize inbred lines (four differential, eight isogenic and 22 commercial inbreeds) to three isolates of this pathogen under greenhouse conditions were studied. The maize inbreeds were selected according to previous testing of resistance based on lesion types in 194 inbreeds under field conditions of plant inoculation with the E. turcicum race 0 (designated as the isolate MRI-Et). The standard procedure was applied to obtained isolates MRIZP-1747 and MRIZP-1416 from resistant and susceptible lesion types, respectively. These lesions were developed on the same leaf of a plant of the experimental hybrid no. 163/99 grown in a nursery at Zemun Polje during 1999. The third isolate (MRIZP-1435) was isolated from a leaf sample originating from the location of Srbobran in which the occurrence of northern corn leaf blight (NCLB), caused by Exserohilum turcicum, was intensive. Based upon virulence/avirulence of three isolates of E. turcicum on differential maize inbred lines, it was found out that the isolate MRIZP-1747 could be classified as race 0, whereas isolates MRIZP-1416 and MRIZP-1435 could be classified as race 1. These are the first results that confirm the presence of race 1 of E. turcicum in Serbia. Not including differential lines, 22 and six lines were resistant to race 0 and race 1, respectively, while eight and five lines were resistant and susceptible to both races, respectively. All isogenic lines not containing the Ht gene were susceptible to both races 0 and 1.U ovom radu proučavani su faktori virulentnosti Exserohilum turcicum i tipovi otpornosti tri seta samooplodnih linija kukuruza (četiri diferencijalne, osam izogene i 22 komercijalne linije) prema tri izolata ovog patogena u uslovima staklare. Linije su izabrane na osnovu prethodnog testiranja tipa otpornosti pega kod 194 samooplodnih linija u poljskim uslovima inokulacije biljaka rasom 0 vrste E. turcicum (označena kao izolat MRI-Et). Standardnim postupkom je iz otpornog tipa pege izolovana kultura izolata MRIZP-1747, a iz osetljivog tipa pege izolat MRIZP-1416. Ove pege su bile obrazovane na istom listu jedne biljke eksperimentalnog hibrida br. 163/99 u rasadniku kukuruza u Zemun Polju u 1999. godini. Izolat MRIZP-1435 je iste godine izolovan iz uzorka lista kukuruza poreklom iz lokaliteta Srbobran u kojem je bila neoubičajeno intenzivna pojava sive pegavosti lista koju prouzrokuje E. turcicum. Na osnovu virulentnosti i avirulentnosti tri izolata E. turcicum na diferencijalnim linijama kukuruza utvrđeno je da se izolat MRIZP-1747 može klasifikovati kao rasa 0, dok se izolati MRIZP- 1416 i MRIZP-1435 mogu klasifikovati kao rasa 1. Ovo su prvi rezultati koji potvrđuju da u Srbiji osim rase 0 postoji i rasa 1 E. turcicum. Ne uključujući diferencijalne linije, otpornost prema rasi 0 ispoljile su 22 linije i šest linija prema rasi 1. Istovremeno, osam linija je bilo otporno prema rasi 0 i pet linija prema rasi 1. Sve izogene linije koje nisu sadržavale Ht gen bile su osetljive prema ovim rasama

Hydrothermal synthesis of novel Sm2(MoO4)3 for selective electrochemical detection of pesticide metol in water samples

The rapid advancement of technology over the past decade has resulted in significant transformations within the photography sector. In photographic processes, photosensitive materials are used by photographers to convert latent images into visible ones. Among other photographic developers, Metol has been used as a monochrome photographic chemical for more than 100 years in Europe. Metol (MTL), chemically N-methyl-p-aminophenol sulphate with formula [HOC6H4NH2(CH3)]2SO4, is also used as a corrosion inhibitor, antioxidant, and antimicrobial, and it serves as an intermediary for the medication diloxanide and dyes for fur and hair [1]. Since it is used in the photographic industry, it is released into the water, contaminating ground, and household water. It can be easily found in different water bodies such as rivers, lakes, ponds, and seas. MTL was found to be a cancerogenic organic pollutant with a significant impact on human health, the environment, animals, plants, and water sources [2]. MTL is non-biodegradable and can accumulate in biotic organisms. It is also related to numerous environmental issues, even in low concentrations. Nevertheless, a larger dose of MTL is necessary to have a substantial effect on several health problems, such as cancer, irritable eyes, slowed heartbeat, skin allergies, and harm to the body's internal blood supply [3]. Therefore, developing a straightforward, quick, affordable, sensitive, and practical method for ML detection in aquatic bodies is imperative. In this study, a susceptible and selective sensor for the detection and quantification of nitrogen-organic pollutant Metol (MTL) was developed. For this purpose, samarium-molybdate (Sm2(MoO4)3 nanoparticles were synthesized by organic solvent-free, eco-friendly, low-cost hydrothermal method and used as an excellent modifier with high catalytic efficiency for implementation into the carbon paste. Electrochemical measurements indicate that the developed electrode facilitates electron transfer processes and enriches the catalytic response. The fabricated Sm2(MoO4)3/CPE sensor has a wide linear range of 0.1 to 100 and 100 to 300 μM of MTL with a low detection and quantification limit of 0.047 µM and 0.156 µM at pH 3 in a BRBS, as supporting electrolyte. The results of using this sensor to analyze real water samples from various sources were satisfactory, indicating that this approach can offer an inexpensive, quick, sensitive sensor for ambient MTL monitorin