Possible Implications of Bacteriospermia on the Sperm Quality,Oxidative Characteristics,and Seminal Cytokine Network in Normozoospermic Men

This study focused on the identification of bacterial profiles of semen in normozoospermic men and their possible involvement in changes to the sperm structural integrity and functional activity. Furthermore, we studied possible fluctuations of selected cytokines, oxidative markers, and antibacterial proteins as a result of bacterial presence in the ejaculate. Sperm motility was assessed with computer-assisted sperm analysis, while sperm apoptosis, necrosis and acrosome integrity were examined with fluorescent methods. Reactive oxygen species (ROS) generation was quantified via luminometry, sperm DNA fragmentation was evaluated using the TUNEL protocol and chromatin-dispersion test, while the JC-1 assay was applied to evaluate the mitochondrial membrane potential. Cytokine levels were quantified with the biochip assay, whilst selected antibacterial proteins were quantified using the ELISA method. The predominant species identified by the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were Staphylococcus hominis, Staphylococcus capitis and Micrococcus luteus. The results revealed that the sperm quality decreased proportionally to the increasing bacterial load and occurrence of conditionally pathogenic bacteria, including Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Antimicrobial susceptibility tests revealed a substantial resistance of randomly selected bacterial strains to ampicillin, vancomycin, tobramycin, and tetracycline. Furthermore, an increased bacterial quantity in semen was accompanied by elevated levels of pro-inflammatory cytokines, including interleukin-1, interleukin-2, interleukin-6, tumor necrosis factor alpha as well as ROS overproduction and lipid peroxidation of the sperm membranes. Our results suggest that semen quality may be notably affected by the bacterial quantity as well as quality. It seems that bacteriospermia may be associated with inflammatory processes, oxidative stress, sperm structural deterioration, and a subsequent risk for the development of subfertility, even in normozoospermic males.     

Large-scale parallel arrays of silicon nanowires via block copolymer directed self-assembly

Extending the resolution and spatial proximity of lithographic patterning below critical dimensions of 20 nm remains a key challenge with very-large-scale integration, especially if the persistent scaling of silicon electronic devices is sustained. One approach, which relies upon the directed self-assembly of block copolymers by chemical-epitaxy, is capable of achieving high density 1?:?1 patterning with critical dimensions approaching 5 nm. Herein, we outline an integration-favourable strategy for fabricating high areal density arrays of aligned silicon nanowires by directed self-assembly of a PS-b-PMMA block copolymer nanopatterns with a L(0) (pitch) of 42 nm, on chemically pre-patterned surfaces. Parallel arrays (5 × 10(6) wires per cm) of uni-directional and isolated silicon nanowires on insulator substrates with critical dimension ranging from 15 to 19 nm were fabricated by using precision plasma etch processes; with each stage monitored by electron microscopy. This step-by-step approach provides detailed information on interfacial oxide formation at the device silicon layer, the polystyrene profile during plasma etching, final critical dimension uniformity and line edge roughness variation nanowire during processing. The resulting silicon-nanowire array devices exhibit Schottky-type behaviour and a clear field-effect. The measured values for resistivity and specific contact resistance were ((2.6 ± 1.2) × 10(5)Ωcm) and ((240 ± 80) Ωcm(2)) respectively. These values are typical for intrinsic (un-doped) silicon when contacted by high work function metal albeit counterintuitive as the resistivity of the starting wafer (～10 Ωcm) is 4 orders of magnitude lower. In essence, the nanowires are so small and consist of so few atoms, that statistically, at the original doping level each nanowire contains less than a single dopant atom and consequently exhibits the electrical behaviour of the un-doped host material. Moreover this indicates that the processing successfully avoided unintentional doping. Therefore our approach permits tuning of the device steps to contact the nanowires functionality through careful selection of the initial bulk starting material and/or by means of post processing steps e.g. thermal annealing of metal contacts to produce high performance devices. We envision that such a controllable process, combined with the precision patterning of the aligned block copolymer nanopatterns, could prolong the scaling of nanoelectronics and potentially enable the fabrication of dense, parallel arrays of multi-gate field effect transistors.     

Potential of proton-enhanced 13C n.m.r. for the classification of kerogens

High resolution n.m.r. spectroscopy, involving the technique of cross-polarization, along with magicangle spinning, was used in the structural characterization of eight kerogens of different origins, selected to represent the three types of kerogens (types I–III evolution paths). The influence of cross-polarization dynamics on the sensitivity of the method and the ratio of individual fractions in the spectrum was studied in more detail. It is suggested that an analysis of the influence of the mixing time is necessary prior to definitive characterization of any sample. Good separation of signals in aliphatic, aromatic, and carboxylic regions was achieved. The general correlation between the ¹³C n.m.r. structural characteristics and the classification based on ultimate analysis of the kerogens (types I–III, van Krevelen atomic H/C vs. O/C diagrams) was found to be satisfactory. The structural features of kerogens derived from ¹³C n.m.r. analysis agreed quite well with characteristics constituting the above mentioned classification. The ¹³C n.m.r. method used in this paper may be considered promising in the classification of kerogens.     

Chemical composition of currant seed extracts and their protective effect on human lymphocytes DNA

On the basis of LC/UV/MS analysis, 35 compounds from the extracts of seeds of black, red, and white currants (2 cultivars of each) were identified. Black currants cultivars contained protocatechuic acid and p-hydroxybenzoic acid, and traces of nitril containing phenolic acids. The presence of synapoyl glucoside was characteristic for cv. Malling Jewel. Sesquiterpenoid glycosides and carboxymethylindol glycosides were present mainly in white and red currant cultivars. Blackcurrant seeds contained higher amounts of flavonoids, especially rutin, isoquercetin, and taxifolin. The currant seed extracts were tested for in vitro protective effect on chromosome aberrations in peripheral human lymphocytes using cytochalasin-B blocked micronucleus (CBMN) assay. The frequency of MN was scored in binucleated cells, and the cultivars of black currants showed the best antioxidant potential. At a concentration of only 0.17 mg/mL, extract of the seed cv. Malling Jewel effected a decrease in the frequency of MN of 60% compared with control cell cultures. PRACTICAL APPLICATION: Our results provide evidence of protective effects of currant seed extracts and isolated pure compounds on cytogenetic damages in human lymphocytes. Thus, currant seed extracts could exert beneficial effects in quite a few diseases, for many of the biological actions have been attributed to their antioxidant properties.     

Application of Matrix Solid-Phase Dispersion and Liquid Chromatography–Ion Trap Mass Spectrometry for the Analysis of Pesticide Residues in Fruits

This study presents an application of rapid and sensitive multiresidue method for the analysis of acephate, acetamipride, atrazine, carbendazim, carbaryl, carbofuran, dimethoate, imidacloprid, linuron, malathion, monocrotophos, monuron, propazine, simazine, and tebufenozide in fruits. The method involves an extraction procedure based on matrix solid-phase dispersion using diatomaceous earth as a dispersant and dichloromethane as the eluent. The target pesticides were determined using liquid chromatography–ion trap mass spectrometry. Quantification of the analytes was carried out using the most sensitive ion transition. Ion trap parameters, like activation q and time, were found to have a prominent influence on method sensitivity for some pesticides and they were optimized accordingly. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional ion transitions besides the ones used for quantification. The method was validated for accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as the relative standard deviation, was in general lower than 20 %. The applicability of the method to routine analysis was tested in real fruit samples with good performance.     

POLYCYCLIC AROMATIC HYDROCARBONS IN PRODUCTS OF A BEET SUGAR FACTORY IN VOJVODINA: LEVELS AND INTAKES

The levels of 16 EPA polycyclic aromatic hydrocarbons (PAHs) were investigated in samples of sugar beets and their products representative for a beet sugar factory located in the central part of Vojvodina, the main agricultural region in Serbia. The sum of the detected PAHs ranged from 51 pg g ^?1 ww for molasses to 391 pg g ^?1 ww for dried sugar beet pulp. The concentration of benzo(a)pyrene (BaP) for all sample types was about or less than 100 pg g ^?1 ww, which is far less than the existing Serbian and EU tolerances set for some foodstuffs. The Serbian intake of BaP via total sugar consumption that ranged from 70–85 g per capita day ^?1 , was assessed to be from 0.029 to 0.035 ng kg ^?1 b.w. day ^?1 . Furthermore, the toxic equivalency factor (TEF) approach was used to estimate the carcinogenicity of PAH mixture found in analyzed samples.     

Polyaniline and polypyrrole prepared in the presence of surfactants: a comparative conductivity study

Polyaniline and polypyrrole have been prepared by chemical oxidative polymerization of the corresponding monomers in an aqueous medium containing an anionic surfactant—sodium bis(2-ethylhexyl) sulfosuccinate, dodecylbenzenesulfonic acid and its sodium salt, and sodium dodecyl sulfate. Determination of the yield, elemental composition and density proved, and FTIR spectroscopy confirmed, that the anionic surfactants become incorporated in the conducting polymers. The polymerizations in the presence of a cationic surfactant, tetradecyltrimethylammonium bromide, were carried out for comparison. While the conductivity of polypyrrole became enhanced after the introduction of an anionic surfactant, the changes in the conductivity of polyaniline were marginal. The conductivity changes in both polymers during thermal ageing were measured at 175 °C. The electrical stability of polyaniline was better than that of polypyrrole. The presence of a surfactant improved the stability of conductivity of polypyrrole but reduced the electrical stability of polyaniline.     

The comparative study of biocomposites based on hydrochar and chitosan-modified urea-formaldehyde resins

To provide new insight into the field of urea-formaldehyde (UF) adhesives science, in this work, for the first time, UF resin was modified with hydrochar of spent mushroom substrate (HCUF) and chitosan (CHUF) to investigate the effect of these bio-fillers on the hydrolytic and thermal stability of in situ prepared UF resins. The characterization of the modified UF biocomposites was performed using X-ray diffraction analysis (XRD), Fourier transforms infrared spectroscopy (FTIR), non-isothermal thermogravimetric analysis (TG), differential thermal gravimetry (DTG), and differential thermal analysis (DTA). Scanning electron micrographs (SEM) of the CHUF and HCUF biocomposites show a spherical structure that differs from each other because the surface of the CHUF biocomposite has pronounced pores that form a network structure. With its hydroxyl and amino groups, chitosan bonding to UF resin through hydrogen bonds, which is confirmed by FTIR analysis. The content of free FA in CHUF biocomposite is 0.06%, while that of HCUF is higher and amounts to 0.48%. The content of released FA in both modified UF biocomposites was similar (2.5% and 2.8% for CHUF and HCUF, respectively). The hydrolytic stability of CHUF is slightly higher compared to the HCUF biocomposite. Thermal analysis shows that the CHUF is thermally more stable because it starts to decompose at a slightly higher temperature than the HCUF biocomposite.