DEVELOPMENT OF THE ALGORITHM FOR IMPLEMENTATION OF ENERGY-EFFICIENT COMPRESSED AIR SYSTEMS WITH ENERGY RECOVERY

In order to improve the energy efficiency of pneumatic systems, this paper presents an algorithm for the devlopment and implementation of an energy efficient pneumatic control system with energy recovery of compressed air. Two different ways of forming closed pneumatic circuits that reuse already used compressed air are presented. Compared to traditional pneumatic control, significant energy savings are achieved

Management of Diabetic Bacterial Foot Infections with Organic Extracts of Liverwort Marchantia debilis from Cameroon

Diabetic bacterial foot infections (DBFIs) are limb-threatening complications in patients with diabetes mellitus, accounting for 50% of diabetes related lower limb amputations in developing countries, representing approximately 20 percent of all diabetes-related hospital admissions with significant healthcare-related costs involved. The widespread problem of bacterial resistance to most commonly used antibiotics places a huge economic burden on the healthcare system, with both increased morbidity and mortality among diabetic patients with foot infections. In this study, the antibacterial activity of organic extracts of the fresh liverwort Marchantia debilis from the North West Region of Cameroon is reported. An exit pool system, where patients presenting with DBFIs consented to be involved in the use of phytomedicines, after long term treatment of ulcers with antibiotics and not yielding significant long term benefit, presented themselves at the Phytobiotechnology Research clinic (PRF). Continuous culture of swabs from foot and toe wounds from 30 infected patients on nutrient agar and MacConkey agars in triplicate as well as Gram stain microscopy, revealed the presence of Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Bacillus species. Light petroleum and methanol extracts of the whole bryophyte plants at 100% concentration were tested. In vitro inhibition of the tested bacterial isolates from the diabetic foot ulcers by M debilis was observed only with the light petroleum extract. No inhibition by the extracts was observed for the Pseudomonas aeruginosa isolate. The light petroleum extract of M debilis was formulated into a petroleum oil based cream named BryoCream (TM). This was administered to 20 of the patients with 90% cure rate in a three week time period. The main nonpolar components were determined by GCMS as lepidozene and beta-barbatene, and by NMR. as stigmasterol and beta-sitosterol. In conclusion, nonpolar extracts from bryophytes from Cameroon could, potentially, be used to treat diabetic bacterial foot infections

An simple technique for synthesis of carbon nanotubes by underwater arc plasma

Applicable, low cost technique for the production of carbon nanotubes by underwater (or solution) AC arc plasma discharge is described. The growth takes place in an AC arc in water solution between graphite electrodes.Physical chemistry 2006 : 8th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 26-29 September 200

PTSP kod policijskih službenika

PTSP kod policijskih službenik

Два нова јатрофанска дитерпена из корена Euphorbia nicaeensis

In the previous study fifteen jatrophane diterpenes were isolated from the Euphorbia nicaeensis latex. Fourteen of them have been shown to be potent P-glycoprotein (P-gp) inhibitor in two MDR cancer cells (NCI-H460/R and DLD1-TxR). The aim of this study was to determine whether and which jatro­phane diterpenes can be isolated from the root of the plant, and then to examine their inhibition power on P-glycoprotein of selected cancer cell lines (NCI-H460, DLD1, U87, NCI-H460/R, DLD1-TxR and U87-TxR). Two previously undes­cribed jatrophane diterpenes were isolated from the root of E. nicaeensis col­lected in Deliblato Sand (Serbia). The structures of the isolated compounds were determined using 1D and 2D NMR, as well as HRESIMS data. The results obtained by MTT assay showed different antitumor potential of these two jatrophanes. Compound 1 inhibited cell growth of non-small cell lung car­cinoma cell lines NCI-H460 and NCI-H460/R, as well as glioblastoma cell lines U87 and U87-TxR, while jatrophane 2 was almost completely inactive in the suppression of cancer cell growth in a given range of concentrations. The obtained results also showed that the isolated compounds have an inhibitory effect on P-glycoprotein, as well as that their inhibitory potential is similar.У претходном истраживању, петнаест дитерпена јатрофанског типа изоловано је из латекса Euphorbia nicaeensis. Њих четрнаест показала су се као снажни инхибитори P-гликопротеина (P-gp) у две MDR ћелијске линије рака (NCI-H460/R и DLD1-TxR). Циљ ове студије био је да се утврди да ли је и које јатрофанске дитерпене могуће изо- ловати из корена биљке, а затим испитивање њихове инхибиторне моћи на P-гликопро- теину одабраних ћелијских линија рака (NCI-H460, DLD1, U87, NCI-H460/R, DLD1-TxR и U87-TxR). Два претходно непозната јатрофана изолованa су из корена E. nicaeensis прикупљеног у Делиблатској пешчари. Структуре изолованих једињења одређене су применом 1D и 2D NMR метода, као и HRESIMS експеримента. Резултати добијени МТТ тестом показали су различит антиканцерогени потенцијал ова два јатрофана. Једињење 1 је инхибирало раст ћелија ћелијских линија неситноћелијског карцинома плућа NCI-H460 и NCI-H460/R, као и ћелијских линија глиобластома U87 и U87-TxR, док је јатрофан 2 био готово потпуно неефикасан у сузбијању растa ћелија карцинома у датом концентрационом опсегу. Добијени резултати су такође показали да 1 и 2 имају инхибиторно дејство на P-гликопротеин, као и да је њихов инхибиторни потенцијал сличан.Part of the theme issue honoring Professor Emeritus Slobodan Milosavljevićs 80th birthday

Significance of diarylheptanoids for chemotaxonomical distinguishing between Alnus glutinosa and Alnus incana

Diarylheptanoids are a group of secondary metabolites widely distributed in the Betulaceae family and characteristic for Alnus species. In this study, the chemotaxonomic power of diarylheptanoids, such as hirsutanonol-5-O-β-d-glucopyranoside, rubranoside A, oregonin, platyphylloside, alnuside A and hirsutanonol, has been investigated in combination with principal component analysis (PCA) for differentiation of Alnus species. Concentrations of six diarylheptanoids in the bark extracts of two natural populations of Alnus glutinosa (black alder) and Alnus incana (gray alder) were determined by ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). PCA clearly shows the separation of three groups. Populations I (A. glutinosa) and II (A. incana) both consisted of individuals of the corresponding species. Four individuals from both sampled populations formed a separate group (population III), which possibly represents a hybrid group. Accordingly, diarylheptanoids may serve in combination with PCA as chemotaxonomic markers at the species level, which may also reveal hybrid species

Антибактеријска својства талусних јетрењача marchantia polymorpha l., conocephalum conicum (l.) dum. И pellia endiviifolia (dicks.) dumort.

The antimicrobial activity of methanol extracts of three thalloid liver­worts, Marchantia polymorpha, Conocephalum conicum and Pellia endiviifolia and bis-bibenzyl marchantin A, the most dominant compound in the methanol extract of M. polymorpha, have been investigated in this research. 1H-NMR spec­troscopy revealed that the M. polymorpha and P. endiviifolia extracts of liverwort contain terpenes, oils, sugars and bis-bibenzyls, while these specific macrocyclic compounds were absent in the C. conicum extract. The anti­mic­robial potential was tested on eight bacterial strains. Antimicrobial effects of extracts and mar­chantin A were observed against Gram-positive bacteria, while they showed no effect against Gram-negative bacteria in both methods used – well diffusion and broth microdilution.У овом раду испитиван је хемијски састав и антибактеријска активност метанолних екстраката три јетрењачe, Marchantia polymorpha, Conocephalum conicum и Pellia endiveifolia и бис-бибензила маршанцина A, доминантне компоненте у метанолном екстракту M. polymorpha. 1H-NMR спектроскопија је показала присуство терпена, уља, шећера и бис-бибензила у екстрактима M. polymorpha и P. endiviifolia, док екстракт C. conicum не садржи специфична макроциклична једињења – бис-бибензиле. Антимикробни потен- цијал је тестиран на осам бактеријских сојева. Антимикробни ефекат маршанцина А уочен је на све грам позитивне сојеве, док је ефекат изостао код грам негативних сојева у обе тестиране методе – дифузионе методе у бунарима и микродилуционе методе у хранљивом бујону

Electrochemical Determination of Redox Potential in Infant Formula and Human Breast Milk

Human breast milk is the best dietary choice for newborn baby, and it is consideredto be a gold standard.All the manufacturers of infant formula aim to produce these products with composition very similar to that of human breast milk. The objects of research of this study are to investigate the significance of breast milk and infant formula in the prevention of oxidative stress, by electrochemical determination of the total antioxidant potential and commonly used DPPH method, demonstrating the relationship between the antioxidant capacity of milk and postnatal age.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/7466

Poster: "Electrochemical Determination of Redox Potential in Infant Formula and Human Breast Milk"

Human breast milk is the best dietary choice for newborn baby, and it isconsideredto be a gold standard.All the manufacturers of infant formula aim to produce theseproducts with composition very similar to that of human breast milk. The objects of research of thisstudy are to investigate the significance of breast milk and infant formula in the prevention ofoxidative stress, by electrochemical determination of the total antioxidant potential and commonlyused DPPH method, demonstrating the relationship between the antioxidant capacity of milk andpostnatal age.Abstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/7465

Tetraciklični triterpenoidi iz vrste Euphorbia nicaeensis All

In this study, three tetracyclic triterpenes: (3S,24S)-tirucall-7-ene-3,24,25-triol (1), (3S,24R)-tirucall-7-ene-3,24,25-triol (2) and inoterpene C (3), were isolated from the milkweed Euphorbia nicaeensis All. using dry-column flash silica gel chromatography and semipreparative normal-phase HPLC. Their structures were determined on the basis of 1D and 2D NMR spectra and literature review. Although these three compounds have previously been isolated from other plant species, this is the first time that they have been isolated from E. nicaeensis.U ovom radu, tri tetraciklična triterpena: (3S,24S)-tirukal-7-en-3,24,25-triol (1), (3S,24R)-tirukal-7-en-3,24,25-triol (2) i inoterpen C (3) su izolovana iz mlečike Euphorbia nicaeensis All. koristeći brzu hromatografiju na suvom stubu silika gela i semipreparativnu normalno-faznu HPLC. Strukture su određene na osnovu 1D i 2D NMR spektara i poređenjem sa literaturom. Iako su ova tri jedinjenja ranije izolovana iz drugih biljnih vrsta, ovo je prvi put da su izolovana iz E. nicaeensis