Ultrasound Evaluation of Extracranial Carotid Artery Lesions in Parkinsonian Patients

The purpose of this investigation was to determine the atherosclerotic changes in patients with vascular parkinsonism and in patients with idiopathic Parkinson’s disease, in order to evaluate the possible influence of the extracranial pathology of carotid arteries in developing lacunar cerebral infarcts. Degree of stenosis and plaque morphology of the extracranial part of carotids in both group of patients were evaluated by color Doppler flow imaging ultrasound investigation and the results were compared. We selected two matched groups of patients with parkinsonism: 22 patients with vascular parkinsonism, and 28 with idiopathic Parkinson’s disease.The atherosclerotic changes found in patients with Parkinson’s disease showed mild carotid lesions with mostly stable calcified plaques and lesser risk for embolic cerebral intravascular events contrary to the higher degree of carotid stenosis found in patients with vascular parkinsonism with mostly mixed plaques prone to embolization. Therefore, we suggest performing ultrasonographic examination of the extracranial part of carotid arteries in all patients with parkinsonism to assess risk of vascular accidents originating from carotid lesions. That would enable adequate treatment of parkinsonism and prevent further occurrence of intracranial vascular changes

Development and optimization of electrochemical method for determination of antioxidant capacity : bachelor thesis

Poznato je kako elektrode izrađene od ugljikovih materijala (grafita, staklastog ugljika, ugljikove paste ili grafena) zbog niskog omskog otpora mogu značajno poboljšati elektroanalitička svojstva osjetnih slojeva i pružaju različite mogućnosti modifikacija koje se često koriste za razvoj visoko osjetljivih senzora za istraživanje elektrokemijskih svojstava i otkrivanje raznih spojeva. Prvi cilj ovog rada bio je razviti jednostavnu elektrokemijsku metodu za određivanje vitamina C (VitC) na posebno konstruiranoj mikroelektrodi od lista pirolitičkog grafita (PGS – Pyrolytic Graphite Sheet). Ciklička voltametrija korištena je za karakterizaciju mikroelektrode i pravokutnovalna voltametrija za elektroanalitičke svrhe. Utvrđen je postupak za kvantificiranje VitC –a u realnom uzorku. VitC pokazuje jednu kvazireverzibilnu reakciju koja uključuje prijenos dva elektrona, dok potencijal oksidacije ovisi o koncentraciji analita. Pravokutnovalna voltametrija (SWV) optimizirana je i provedeno je analitičko određivanje u području potencijala od –0,30 do 0,80 V. Dobiveni rezultati pokazuju linearni odziv PGS elektrode u širokom području koncentracija. Drugi cilj bio je utvrditi učinak dodavanja različite vrste „zelenog“ biootpada na rast biljaka, sadržaj VitC –a i antioksidacijsku aktivnost u rikoli (Eruca sativa L) uporabom PGS elektrode. Dobiveni rezultati uspoređeni su sa standardiziranim metodama. Nakon tri tjedna uzgoja uočene su male razlike u rastu i velike razlike u određenim nutritivnim karakteristikama. Dodavanje ljuske kikirikija doprinosi prozračivanju tla, a primijećen je i najbrži razvoj zdrave i zelene Eruca sativa. Dodatak crne kave čini tlo blago alkalnim i rezultira značajnim povećanjem sadržaja VitC –a i antioksidacijske aktivnosti.It is known that electrodes made of carbon materials (graphite, glassy carbon, carbon paste or graphene) due to low ohmic resistance can significantly improve the electroanalytical properties of sensitive layers and provide a variety of modification options that are often used to develop highly sensitive sensors for investigation of electrochemical properties and give opportunity for detection of various compounds. The first goal of this work was to develop a simple electrochemical method for the determination of vitamin C (VitC) on a specially constructed microelectrode made from the Pyrolytic Graphite Sheet (PGS). Cyclic voltammetry was used to characterize the microelectrode and square wave voltammetry for electroanalytical purposes. A procedure for quantifying VitC in a real sample was established. VitC shows a single quasi–reversible reaction involving the transfer of two electrons, while the oxidation potential depends on the analyte concentration. SWV was optimized and analytical determination was performed in the potential range from –0.30 to 0.80 V. The obtained results show a linear response of the PGS electrode in a wide range of concentrations. The second goal was to determine the effect of adding different types of "green" biowaste on plant growth, VitC content and antioxidant activity in arugula (Eruca sativa L) using PGS electrode. The obtained results were compared with standardized methods. After three weeks of cultivation, small differences in growth and large differences in certain nutritional characteristics were observed. The addition of peanut shell contributes to soil aeration, and the fastest development of healthy and green Eruca sativa has been observed. The addition of black coffee makes the soil slightly alkaline and results in a significant increase in VitC content and antioxidant activity

ELECTROCHEMICAL AND SPECTROPHOTOMETRIC CHARACTERIZATION OF ANTIOXIDANT ACTIVITY OF DALMATIAN PLANT EXTRACTS : diploma thesis

Antioksidacijsko djelovanje prirodnih spojeva koji se nalaze u začinima, odnosno bilju procijenjeno je korištenjem elektrokemijskih i spektrofotometrijskih metoda. Odabrane su karakteristične biljke dalmatinskog područja: ružmarin, lovor i smilje. U svrhu postizanja što bolje ekstrakcije testirane su 4 metode ekstrakcije bioaktivnih tvari iz vodenih pripravaka. Izrađena je elektroda od pirolitičkog grafita, površine 7,5×10 -4 cm 2 , uz hipotezu kako će upravo izvanredne osobine ovog materijala omogućiti i olakšati prijenos elektrona između analita i elektrode. Optimiranjem parametara diferencijalne pulsne voltamtrije (DPV) pronađeni su uvjeti koji su dali visoku osjetljivost, selektivnost i reproducibilnost rezultata. Faktor 35,8 mA/cm 2 ukazao je na visoku osjetljivost i dobru linearnost (R 2 =0,980) predložene metode. Uz odabrane parametre određena je koncentracija galne kiseline u realnim uzorcima DPV metodom. Koncentracija ukupnih fenola i antioksidacijska aktivnost određena je i spektrofotometrijskim (SP) metodama. Kao najbolja metoda ekstrakcije prometnula se mikrovalna ekstrakcija za uzorke ružmarina i lovora, a jednostavna ekstrakcija na 100 ºC u trajanju od 5 minuta za ekstrakte smilja. Najveća koncentracija galne kiseline SP metodom uočena je u ekstraktu smilja, 917,1 mg dm -3 , a najveća antioksidacijska aktivnost zabilježena je u ekstraktu ružmarina potpomognuto mikrovalovima, 6406,4 μM Fe 2+ . Isti trend slijede i rezultati DPV metode. U svrhu procjene primjene elektrokemijskih metoda za određivanje galne kiseline, odnosno ukupnih fenola, napravljena je matematička korelacija između DPV i SP metoda. Konstantan odnos koncentracije galne kiseline dobiven DPV i SP metodom u iznosu približno 5,62 sugerira kako je predložena metoda pogodna za procjenu ukupnih fenola u realnim uzorcima.The antioxidant activity of small natural compounds found in spices and herbs was evaluated using electrochemical and spectrophotometric methods. The characteristic plants of the Dalmatian region were selected: rosemary, bay leaf and immortelle. In order to achieve the best possible extraction, 4 methods for the extraction of bioactive substances from aqueous preparations were tested. An electrode was made of pyrolytic graphite with a surface area of 7,5×10 -4 cm 2 , hypothesizing that the exceptional properties of this material would enable and facilitate electron transfer between the analyte and the electrode. By optimizing the parameters of differential pulse voltammetry (DPV), conditions were found that ensure high sensitivity, selectivity and reproducibility of results. The factor 35,8 mA/cm 2 indicates a high sensitivity and good linearity (R 2 =0,980) of the proposed method. Together with the selected parameters, the concentration of gallic acid in real samples was determined using the DPV method. The concentration of total phenols and antioxidant activity were also determined by spectrophotometric methods (SP). The best extraction method was microwave extraction for rosemary and bay leaf samples, simple extraction at 100 ºC for 5 minutes for the immortelle extract. The highest gallic acid concentration by SP method was found in immortelle extract (917,1 mg dm -3 ) and the highest antioxidant activity in microvawe-assisted rosemary extract (6406,4 μM Fe 2+ ). The results of DPV method follow the same trend. To evaluate the application of electrochemical methods for the determination of gallic acid or total phenolics, a mathematical correlation was established between the DPV and SP methods. The constant ratio of the gallic acid concentration determined by the DPV and SP methods of about 5,62 indicates that the proposed method is suitable for the estimation of total phenols in real samples

ELECTROCHEMICAL AND SPECTROPHOTOMETRIC CHARACTERIZATION OF ANTIOXIDANT ACTIVITY OF DALMATIAN PLANT EXTRACTS : diploma thesis

Antioksidacijsko djelovanje prirodnih spojeva koji se nalaze u začinima, odnosno bilju procijenjeno je korištenjem elektrokemijskih i spektrofotometrijskih metoda. Odabrane su karakteristične biljke dalmatinskog područja: ružmarin, lovor i smilje. U svrhu postizanja što bolje ekstrakcije testirane su 4 metode ekstrakcije bioaktivnih tvari iz vodenih pripravaka. Izrađena je elektroda od pirolitičkog grafita, površine 7,5×10 -4 cm 2 , uz hipotezu kako će upravo izvanredne osobine ovog materijala omogućiti i olakšati prijenos elektrona između analita i elektrode. Optimiranjem parametara diferencijalne pulsne voltamtrije (DPV) pronađeni su uvjeti koji su dali visoku osjetljivost, selektivnost i reproducibilnost rezultata. Faktor 35,8 mA/cm 2 ukazao je na visoku osjetljivost i dobru linearnost (R 2 =0,980) predložene metode. Uz odabrane parametre određena je koncentracija galne kiseline u realnim uzorcima DPV metodom. Koncentracija ukupnih fenola i antioksidacijska aktivnost određena je i spektrofotometrijskim (SP) metodama. Kao najbolja metoda ekstrakcije prometnula se mikrovalna ekstrakcija za uzorke ružmarina i lovora, a jednostavna ekstrakcija na 100 ºC u trajanju od 5 minuta za ekstrakte smilja. Najveća koncentracija galne kiseline SP metodom uočena je u ekstraktu smilja, 917,1 mg dm -3 , a najveća antioksidacijska aktivnost zabilježena je u ekstraktu ružmarina potpomognuto mikrovalovima, 6406,4 μM Fe 2+ . Isti trend slijede i rezultati DPV metode. U svrhu procjene primjene elektrokemijskih metoda za određivanje galne kiseline, odnosno ukupnih fenola, napravljena je matematička korelacija između DPV i SP metoda. Konstantan odnos koncentracije galne kiseline dobiven DPV i SP metodom u iznosu približno 5,62 sugerira kako je predložena metoda pogodna za procjenu ukupnih fenola u realnim uzorcima.The antioxidant activity of small natural compounds found in spices and herbs was evaluated using electrochemical and spectrophotometric methods. The characteristic plants of the Dalmatian region were selected: rosemary, bay leaf and immortelle. In order to achieve the best possible extraction, 4 methods for the extraction of bioactive substances from aqueous preparations were tested. An electrode was made of pyrolytic graphite with a surface area of 7,5×10 -4 cm 2 , hypothesizing that the exceptional properties of this material would enable and facilitate electron transfer between the analyte and the electrode. By optimizing the parameters of differential pulse voltammetry (DPV), conditions were found that ensure high sensitivity, selectivity and reproducibility of results. The factor 35,8 mA/cm 2 indicates a high sensitivity and good linearity (R 2 =0,980) of the proposed method. Together with the selected parameters, the concentration of gallic acid in real samples was determined using the DPV method. The concentration of total phenols and antioxidant activity were also determined by spectrophotometric methods (SP). The best extraction method was microwave extraction for rosemary and bay leaf samples, simple extraction at 100 ºC for 5 minutes for the immortelle extract. The highest gallic acid concentration by SP method was found in immortelle extract (917,1 mg dm -3 ) and the highest antioxidant activity in microvawe-assisted rosemary extract (6406,4 μM Fe 2+ ). The results of DPV method follow the same trend. To evaluate the application of electrochemical methods for the determination of gallic acid or total phenolics, a mathematical correlation was established between the DPV and SP methods. The constant ratio of the gallic acid concentration determined by the DPV and SP methods of about 5,62 indicates that the proposed method is suitable for the estimation of total phenols in real samples

Development and optimization of electrochemical method for determination of antioxidant capacity : bachelor thesis

Poznato je kako elektrode izrađene od ugljikovih materijala (grafita, staklastog ugljika, ugljikove paste ili grafena) zbog niskog omskog otpora mogu značajno poboljšati elektroanalitička svojstva osjetnih slojeva i pružaju različite mogućnosti modifikacija koje se često koriste za razvoj visoko osjetljivih senzora za istraživanje elektrokemijskih svojstava i otkrivanje raznih spojeva. Prvi cilj ovog rada bio je razviti jednostavnu elektrokemijsku metodu za određivanje vitamina C (VitC) na posebno konstruiranoj mikroelektrodi od lista pirolitičkog grafita (PGS – Pyrolytic Graphite Sheet). Ciklička voltametrija korištena je za karakterizaciju mikroelektrode i pravokutnovalna voltametrija za elektroanalitičke svrhe. Utvrđen je postupak za kvantificiranje VitC –a u realnom uzorku. VitC pokazuje jednu kvazireverzibilnu reakciju koja uključuje prijenos dva elektrona, dok potencijal oksidacije ovisi o koncentraciji analita. Pravokutnovalna voltametrija (SWV) optimizirana je i provedeno je analitičko određivanje u području potencijala od –0,30 do 0,80 V. Dobiveni rezultati pokazuju linearni odziv PGS elektrode u širokom području koncentracija. Drugi cilj bio je utvrditi učinak dodavanja različite vrste „zelenog“ biootpada na rast biljaka, sadržaj VitC –a i antioksidacijsku aktivnost u rikoli (Eruca sativa L) uporabom PGS elektrode. Dobiveni rezultati uspoređeni su sa standardiziranim metodama. Nakon tri tjedna uzgoja uočene su male razlike u rastu i velike razlike u određenim nutritivnim karakteristikama. Dodavanje ljuske kikirikija doprinosi prozračivanju tla, a primijećen je i najbrži razvoj zdrave i zelene Eruca sativa. Dodatak crne kave čini tlo blago alkalnim i rezultira značajnim povećanjem sadržaja VitC –a i antioksidacijske aktivnosti.It is known that electrodes made of carbon materials (graphite, glassy carbon, carbon paste or graphene) due to low ohmic resistance can significantly improve the electroanalytical properties of sensitive layers and provide a variety of modification options that are often used to develop highly sensitive sensors for investigation of electrochemical properties and give opportunity for detection of various compounds. The first goal of this work was to develop a simple electrochemical method for the determination of vitamin C (VitC) on a specially constructed microelectrode made from the Pyrolytic Graphite Sheet (PGS). Cyclic voltammetry was used to characterize the microelectrode and square wave voltammetry for electroanalytical purposes. A procedure for quantifying VitC in a real sample was established. VitC shows a single quasi–reversible reaction involving the transfer of two electrons, while the oxidation potential depends on the analyte concentration. SWV was optimized and analytical determination was performed in the potential range from –0.30 to 0.80 V. The obtained results show a linear response of the PGS electrode in a wide range of concentrations. The second goal was to determine the effect of adding different types of "green" biowaste on plant growth, VitC content and antioxidant activity in arugula (Eruca sativa L) using PGS electrode. The obtained results were compared with standardized methods. After three weeks of cultivation, small differences in growth and large differences in certain nutritional characteristics were observed. The addition of peanut shell contributes to soil aeration, and the fastest development of healthy and green Eruca sativa has been observed. The addition of black coffee makes the soil slightly alkaline and results in a significant increase in VitC content and antioxidant activity

Development and optimization of electrochemical method for determination of antioxidant capacity : bachelor thesis

Poznato je kako elektrode izrađene od ugljikovih materijala (grafita, staklastog ugljika, ugljikove paste ili grafena) zbog niskog omskog otpora mogu značajno poboljšati elektroanalitička svojstva osjetnih slojeva i pružaju različite mogućnosti modifikacija koje se često koriste za razvoj visoko osjetljivih senzora za istraživanje elektrokemijskih svojstava i otkrivanje raznih spojeva. Prvi cilj ovog rada bio je razviti jednostavnu elektrokemijsku metodu za određivanje vitamina C (VitC) na posebno konstruiranoj mikroelektrodi od lista pirolitičkog grafita (PGS – Pyrolytic Graphite Sheet). Ciklička voltametrija korištena je za karakterizaciju mikroelektrode i pravokutnovalna voltametrija za elektroanalitičke svrhe. Utvrđen je postupak za kvantificiranje VitC –a u realnom uzorku. VitC pokazuje jednu kvazireverzibilnu reakciju koja uključuje prijenos dva elektrona, dok potencijal oksidacije ovisi o koncentraciji analita. Pravokutnovalna voltametrija (SWV) optimizirana je i provedeno je analitičko određivanje u području potencijala od –0,30 do 0,80 V. Dobiveni rezultati pokazuju linearni odziv PGS elektrode u širokom području koncentracija. Drugi cilj bio je utvrditi učinak dodavanja različite vrste „zelenog“ biootpada na rast biljaka, sadržaj VitC –a i antioksidacijsku aktivnost u rikoli (Eruca sativa L) uporabom PGS elektrode. Dobiveni rezultati uspoređeni su sa standardiziranim metodama. Nakon tri tjedna uzgoja uočene su male razlike u rastu i velike razlike u određenim nutritivnim karakteristikama. Dodavanje ljuske kikirikija doprinosi prozračivanju tla, a primijećen je i najbrži razvoj zdrave i zelene Eruca sativa. Dodatak crne kave čini tlo blago alkalnim i rezultira značajnim povećanjem sadržaja VitC –a i antioksidacijske aktivnosti.It is known that electrodes made of carbon materials (graphite, glassy carbon, carbon paste or graphene) due to low ohmic resistance can significantly improve the electroanalytical properties of sensitive layers and provide a variety of modification options that are often used to develop highly sensitive sensors for investigation of electrochemical properties and give opportunity for detection of various compounds. The first goal of this work was to develop a simple electrochemical method for the determination of vitamin C (VitC) on a specially constructed microelectrode made from the Pyrolytic Graphite Sheet (PGS). Cyclic voltammetry was used to characterize the microelectrode and square wave voltammetry for electroanalytical purposes. A procedure for quantifying VitC in a real sample was established. VitC shows a single quasi–reversible reaction involving the transfer of two electrons, while the oxidation potential depends on the analyte concentration. SWV was optimized and analytical determination was performed in the potential range from –0.30 to 0.80 V. The obtained results show a linear response of the PGS electrode in a wide range of concentrations. The second goal was to determine the effect of adding different types of "green" biowaste on plant growth, VitC content and antioxidant activity in arugula (Eruca sativa L) using PGS electrode. The obtained results were compared with standardized methods. After three weeks of cultivation, small differences in growth and large differences in certain nutritional characteristics were observed. The addition of peanut shell contributes to soil aeration, and the fastest development of healthy and green Eruca sativa has been observed. The addition of black coffee makes the soil slightly alkaline and results in a significant increase in VitC content and antioxidant activity

Development and Optimization of Electrochemical Method for Determination of Vitamin C

The focus of this work was to develop a simple electrochemical method for the determination of vitamin C (VitC) by using a specially constructed microelectrode made from pyrolytic graphite sheet (PGS). A procedure for quantifying VitC in a real sample was established. VitC shows a single quasi-reversible reaction. The method was optimized, and analytical determination was performed by using cyclic voltammetry and square wave voltammetry for electroanalytical purposes. The obtained results show a linear response of the PGS electrode in a wide concentrations range. For the lower concentration range, 0.18–7.04 µg L−1, the sensitivity is 11.7 µAcm−2/mgL−1, while for the higher concentration range, 10.6–70.4 µg L−1, the sensitivity is 134 µAcm−2/mgL−1, preserving the linearity of 0.998 and 0.999. The second objective was to determine the effect of the addition of five different types of “green” biowaste on plant growth, VitC content, and antioxidant activity in arugula (Eruca sativa L.) using the developed method. After three weeks of cultivation, small differences in growth and large differences in certain nutritional characteristics were observed. The addition of black coffee makes the soil slightly alkaline and causes a significant increase in VitC content and antioxidant activity