Composition, Antioxidant Potential, and Antimicrobial Activity of Helichrysum plicatum DC. Various Extracts

Helichrysum plicatum DC. is widely used in folk medicine in treating a variety of health disorders. The aim of this study was to examine the influence of different extraction solvents on the chemical composition, antioxidant potential, and antimicrobial activities of H. plicatum. Aerial parts were separately extracted with ethanol, dichloromethane, and sunflower oil. The oil extract (OE) was re-extracted with acetonitrile. A total of 142 compounds were tentatively identified in ethanolic (EE), dichloromethane (DCME), and acetonitrile (ACNE) extracts using HPLC-DAD/ESI-ToF-MS. The dominant compound class in all extracts were α-pyrones, alongside flavonoids in EE, terpenoids in DCME and ACNE, and phloroglucinols in DCME. The antioxidant potential of the extracts was assessed by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. EE and DCME possessed the most potent radical scavenging capacity. Antimicrobial activity was investigated on eight bacterial, two yeast, and one fungal species. All extracts exhibited high antifungal and notable antibacterial activities compared to control substances, with DCME being the most potent. DCME exhibited stronger antimicrobial activity against P. aeruginosa than the standard chloramphenicol

Oxidative Stress Markers in GnRH AgonistaAnd Antagonist Protocols in IVF

Background: Our aim was to study the effect of GnRH agonist and antagonist protocols of ovarian stimulation on oxidative stress parameters in serum and the influence of oxidative stress parameters change on the outcome of IVF cycles. Methods: This prospective study included 82 patients who under went IVF procedures. We determined SOD, MDA and SH groups in serum. Serum samples were obtained between the second and fourth day of the cycle and on the day of HCG administration during ovarian stimulation. Results: Patients were divided into two groups depending on the protocol of stimulation. The mean total and mature oocytes number and number of fertilized oocytes were higher in GnRH agonist group. There was no significant difference in biochemical pregnancy, miscarriage and live -birth rate in both groups. Mean serum SOD was significantly lower, while mean serum MDA and SH groups were significantly higher after ovarian stimulation. Delivery rate was higher in patients without OS while miscarriage rate was higher in patients with OS. Conclusions: Our study confirmed that there is a difference in the concentration of oxidative stress parameters before and after ovarian stimulation. IVF outcome is better in patients without OS after ovarian stimulation. However, the protocol of ovarian stimulation is neither associated with a change in oxidative stress parameters nor with the outcome of ART procedures

Microbiological parameters and sensory characteristics of sliced meat products packaged in modified atmosphere throughout the shelf life

Demand for food, such as ready to eat food which is easy to consume with as long as possible shelf life, has continuously increased due to the modernization and growth of the human population. Sliced meat products that were normally packed and placed on the market in vacuum packaging, were packed in MAP with the aim of extending the shelf life. The research objective of this study was to determine the microbiological parameters and sensory characteristics of 6 sliced meat products packaged in modified atmosphere (smoked pork loin with added water, Budim sausage, Kamendin pancetta, Smoked pork neck with added water, Kulen, Ham for pizza with added water) during the expected shelf life. This study included sensory analysis and microbiological parameters (Listeria monocytogenes, Enterobacteriaceae and total aerobic mesophilic microorganisms). All samples of sliced meat products packaged in modified atmosphere had satisfactory microbiological and sensory characteristics during the expected shelf life which ranged from 30 to 90 days

Effects of Selected Essential Oils on Listeria monocytogenes in Biofilms and in a Model Food System

The composition of 18 essential oils was determined using gas chromatography–mass spectrometry, and their antilisterial activity was evaluated by the disk diffusion method, followed by the determination of the minimum inhibitory and minimum bactericidal concentrations. The most active essential oils were oregano, thyme, cinnamon, winter savory, and clove, with MIC values ranging from 0.09 to 1.78 µL/mL. We investigated the biofilm-forming potential of Listeria monocytogenes on polystyrene at 5 °C, 15 °C, and 37 °C in three different media. The formation of biofilm was found to be dependent on the temperature and the availability of nutrients. After treatment with selected essential oils, the reduction in biofilm biomass was in the range of 32.61% and 78.62%. Micromorphological changes in the L. monocytogenes treated by oregano and thyme essential oils were observed in the form of impaired cell integrity and cell lyses by using scanning electron microscope. Oregano and thyme essential oils (MIC and 2MIC) significantly (p < 0.05) reduced the population of L. monocytogenes in minced pork meat during storage at 4 °C. In conclusion, the obtained results indicated the good activity of some selected essential oils on L. monocytogenes, with bacteriostatic, bactericidal, and antibiofilm effects at very low concentrations

Methanol oxidation on an ink type electrode using Pt supported on high area carbons

Methanol oxidation was investigated on the following Pt catalysts: bare Pt electrode, Pt covered by nafion (R) film, and pt catalysts supported on high area carbons in the form of an ink. The reaction was carried out using slow linear potential sweep and potentiostatic steps. Active surface area of Pt particles was estimated from hydrogen desorption charge on cyclic voltammograms. The influence of Nafion film, Pt loading, type of carbon support, and methanol concentration were studied. No influence of Nafion (R) film on kinetic parameters of methanol oxidation was found. Tafel slope on smooth Pt was found to be about 90 mV dec(-1), while on supported Pt catalysts time depende(n)t values between 140 and 90 mV dec(-1) were estimated from the potentiostatic decays by using data between 0.5 and 5 min. Specific activity was slightly dependent on Pt loading with flat maximum at about 20%, Pt. Activity of Pt/SAB catalyst was two to three times higher than that of Pt/BP and Pt/XC-72 catalysts

Kinetic study of methanol oxidation on carbon-supported PtRu electrocatalyst

Methanol electrooxidation was investigated on the carbon-supported PtRu electrocatalyst (1:1 atomic ratio) in acid media. X-ray diffraction measurement indicated alloying of Pt and Ru. Cyclic voltammetry of the sample reflects the amount of Ruin the catalyst and its ability to adsorb OH radicals. Tafel plots for the oxidation of 0.02-3 M methanol in the solutions containing 0.05-1 M HClO4 and in the temperature range 27-40 degreesC showed reasonably well-defined linear region with the slope of about 115 mV dec(-1) at the low currents, irrespective of the experimental conditions employed. Reaction order with respect to methanol was found to be 0.5. A correlation between methanol oxidation rate and pseudocapacitive current of OH adsorption on Ru sites was established. It was proposed that bifunctional mechanism is operative with the reaction between methanol residues adsorbed on Pt sites and OH radicals adsorbed on Ru sites as the rate-determining step

Toxic Metal and Trace Element Concentrations in Blood and Outcome of In Vitro Fertilization in Women

The aim of this study was to investigate the association of trace element and toxic metal concentrations in blood and the outcome of in vitro fertilization (IVF). The study included 104 consecutive patients that underwent assisted reproductive technology (ART) procedures. The following parameters were determined: cadmium (Cd), mercury (Hg), arsenic (As), and lead (Pb); and copper (Cu), zinc (Zn), selenium (Se), and magnesium (Mg). Serum samples were obtained before commencing stimulation. Patients with smoking habit had significantly higher Pb concentrations (P=0.022), as well as higher concentrations of As and Hg but not significantly. All subjects were divided into groups of pregnant and nonpregnant patients. Pregnant patients had lower mean values of Mg (P=0.009), As (P lt 0.05), and Pb (P=0.034), compared to nonpregnant, and a significant correlation between pregnancy outcome and concentrations of Mg, Cd, and Pb was found. Women who had had delivered had lower Mg (P=0.009) and Cd (P=0.014) concentrations. There was a significant correlation of the negative outcome of IVF procedure with higher concentrations of Pb (P=0.046) and Cd (P=0.012). In conclusion, our results suggest that there is a difference in Mg, Pb, and Cd concentrations between pregnant and nonpregnant women. There was no association between toxic metals and number and quality of oocytes and embryos, while there was with fertilization rate. Concerning trace elements, we did not find the correlation of trace elements with oocyte number and quality, nor with a number of fertilized oocytes, except for Cu. Patients who were pregnant had lower concentrations of Mg

Poor ovarian response to stimulation for in vitro fertilization

The term “poor respond (POR) patients” is used for the group of women who respond badly to usual doses of gonadotropins in in vitro fertilization (IVF) treatments; the consequence is low pregnancy rate. A consensus was reached on the minimal criteria needed to define POR. At least two of the following three features must be present: 1. advanced maternal age (40 years or more) 2. previous POR (3 or less oocytes with a conventional stimulation protocol) 3. abnormal ovarian reserve (AMH 0.5-1.1 ng/ml or AFC 5-7). The aim is to find better therapeutic options for these patients. Increased levels of day 3 follicle stimulating hormone (FSH) and estradiol (E2), as well as decreased levels of anti-Mьllerian hormone (AMH) and antral follicle count (AFC), can be used to assess ovarian reserve, as indirect predictive tests. A larger number of well designed, large scale, randomized, controlled trials are needed to assess the efficacy of different management strategies for poor responders: flare up gonadotropin releasing hormone (GnRH) agonist protocols, modified long GnRH agonist mini-dose protocols, luteal initiation GnRH agonist stop protocol, pretreatment with estradiol - GnRH antagonist in luteal phase, natural cycle aspiration or natural cycle aspiration GnRH antagonist controlled, adjuvant therapy with growth hormone or dehydroepiandrosterone (DHEA). The results of up to now used protocols are unsatisfactory and stimulation of the ovulation in poor responders remains a challenge, especially when bearing in mind that in the majority of cases the patients will be menopausal in relatively short period of time

The properties of carbon-supported hydrous ruthenium oxide obtained from RuOxHy sol

Preparation of RuOxHy/carbon black nanocomposite material was performed by the impregnation method starting from RuOxHy sol as a precursor. Black Pearls 2000(R) (BP) and Vulcan(R) XC-72 R (XC) were used as supporting materials. Samples of the composite were calcined in nitrogen atmosphere at temperatures from 130 to 450 degreesC. Chemical and structural characterization of the precursor and the composites was performed by using energy-dispersive X-ray fluorescence spectroscopy (EDXRFS), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). These techniques showed that the oxide impregnated into carbon support is hydrous and amorphous. The amorphous structure is maintained if the composite is calcined up to 300 degreesC, while the lowintensity peak at 2theta position that corresponds to the most intensive peak of the rutile structure was registered at 450 degreesC. The capacitance of the composite was determined using cyclic voltammetry. It was found that the capacitance is dependent on calcination temperature and surface area of the carbon black support. The highest specific capacitance of about 700 F g(-1) of composite was registered for RuOxHy supported on BP and calcined at 300 degreesC while four times lower values was obtained for RuOxHy supported on XC. The capacitance measurements indicated that XC-supported RuOXHy composite is highly porous while BP-supported one is more compact

Reduction of polycyclic aromatic hydrocarbons in common carp meat smoked in traditional conditions

Common carp meat was smoked in traditional conditions without filter and with zeolite, granular activated carbon, and gravel filters. The aim of this study was to determine the influence of using different filters in traditional smoking conditions on 16 polycyclic aromatic hydrocarbons from the Environmental Protection Agency list (16 US-EPA PAHs). Determination and quantification of PAHs were performed by gas chromatography-mass spectrometry (GC-MS). According to the obtained results, all examined samples of common carp meat smoked in traditional conditions were safe for consumers regarding to the European Commission Regulation on PAH content. After statistical analysis, the zeolite filter appeared to be the best one based on food safety of traditional production of smoked common carp meat. Application of any of these filters to produce smoked common carp meat in traditional conditions resulted in a safer product, as lower levels of PAHs were obtained