Synovial-type (group II) phospholipase A2 human seminal plasma

Phospholipase A2 (PLA2) was analysed in seminal plasma of fertile, subfertile, and vasectomized men as well as in prostatic secretion and tissue. Immunological cross-reactivity was observed between synovial-type PLA2 antiserum and the enzyme present in seminal plasma. There was a highly significant correlation between the concentration of the synovial-type PLA2, as measured by a time-resolved fluoroimmunoassay and the catalytic activity of the PLA2. The results show that the PLA2 content in human seminal plasma is very high (approximately 1000 times of that present in blood plasma) and that the enzyme belongs to the synovial-type group II phospholipase A2. The results also indicate that the enzyme is secreted by the prostate.     

Mechanical properties and strength retention of carbon fibre-reinforced liquid crystalline polymer (LCP/CF) composite: an experimental study on rabbits

A novel composite material with ultra-high flexural strength and cortical-bone-matched elastic modulus made of liquid crystalline polymer reinforced with carbon fibres (LCP/CF) is described. Cylindrical rods of 3.2 mm diameter and 50 mm length were fabricated by a preimpregnation/pultrusion method. The initial mechanical properties of the LCP/CF rods were as follows: flexural strength 448 MPa, flexural modulus 43 GPa, shear strength 164 MPa, and interlaminar shear strength 15.3 MPa. In the in vitro study the LCP/CF rods were immersed in phosphate-buffered saline of 37 degrees C for 12, 24, and 52 weeks. In the in vivo study the LCP/CF rods were implanted into the medullary cavity of both femora and subcutaneous tissue of the New Zealand White rabbits for 12, 24, and 52 weeks. The flexural strength of the LCP/CF rods at 52 weeks was 463 MPa in saline, 467 MPa in the subcutaneous tissue and 466 MPa in the medullary cavity of the femur. The flexural modulus was 44.6, 48.9 and 46.2 GPa, respectively. The corresponding shear strength values were 160, 178 and 181 MPa. We conclude that the LCP/CF is a promising material for high-load applications and the LCP/CF rods retain their initial mechanical properties in one-year follow-up in vivo and in vitro.     

High frequency one-step gene replacement in Trichoderma reesei. II. Effects of deletions of individual cellulase genes

Four cellulase genes of Trichoderma reesei, cbh1, cbh2, egl1 and egl2, have been replaced by the amdS marker gene. When linear DNA fragments and flanking regions of the corresponding cellulase locus of more than 1 kb were used, the replacement frequencies were high, ranging from 32 to 52%. Deletion of the major cellobiohydrolase 1 gene led to a 2-fold increase in the production of cellobiohydrolase II; however, replacement of the cbh2 gene did not affect the final cellulase levels and deletion of egl1 or egl2 slightly increased production of both cellobiohydrolases. Based on our results, endoglucanase II accounts for most of the endoglucanase activity produced by the hypercellulolytic host strain. Furthermore, loss of the egl2 gene causes a significant drop in the filter paper-hydrolysing activity, indicating that endoglucanase II has an important role in the total hydrolysis of cellulose.     

Immobilization of arsenic in a tailings material by ferrous iron treatment

Weathering and internal dissolution processes in mining waste materials may mobilize elevated levels of arsenic (As), contaminating ground and surface waters. Treating the polluted waters with iron oxyhydroxides is an established remediation method. By contrast, little knowledge is available to stabilize As in source materials by treating it with Fe precipitates and, on this way, to prevent the generation of polluted waters. In the present work the efficiency of Fe(II) treatment on As immobilization in a tailings material (TM) was studied with regard to the Fe:As molar ratio, the influence of CaCO3 amendment, and the As desorption at continued intensive leaching of Fe-treated TM. Fe precipitates were created by aerobic treatment of TM with Fe(II)sulfate at several Fe:As molar ratios with or without adding CaCO3, followed by aging the Fe-treated TM. The As retention in the treated tailings was studied by 4-fold elution with water, and the As desorption kinetics was examined by suspension leaching in laboratory microcosms over 3 weeks. Fe(II) treatment of TM reduced the water-extractable total As to <10 microg/L as the Fe:As molar ratio increased from 0 to 8. The water-soluble As of Fe-treated tailings could be reduced to 10-30 microg/L also under conditions of intensive leaching. Stabilizing the pH with CaCO3 resulted in consistently higher As release. The As desorption data followed the first-order kinetics in the early time stages of the desorption whereas at longer times the parabolic diffusion model was valid.     

Pseudo-Starvation Driven Energy Expenditure Negatively Affects Ovarian Follicle Development

In the present investigation, we examined whether a change in whole body energy fluxes could affect ovarian follicular development, employing mice ectopically expressing uncoupling protein 1 in skeletal muscle (UCP1-TG). Female UCP1-TG and wild-type (WT) mice were dissected at the age of 12 weeks. Energy intake and expenditure, activity, body weight and length, and body composition were measured. Plasma insulin, glucose, leptin, plasma fibroblast growth factor 21 (FGF21) and plasma insulin-like growth factor 1 (IGF1) levels were analyzed and ovarian follicle and corpus luteum numbers were counted. IGF1 signaling was analyzed by immunohistochemical staining for the activation of insulin receptor substrate 1/2 (IRS1/2) and AKT. UCP1-TG female mice had increased energy expenditure, reduced body size, maintained adiposity, and decreased IGF1 concentrations compared to their WT littermates, while preantral and antral follicle numbers were reduced by 40% and 60%, respectively. Corpora lutea were absent in 40% of the ovaries of UCP1-TG mice. Phospho-IRS1, phospho-AKT -Ser473 and -Thr308 immunostaining was present in the granulosa cells of antral follicles in WT ovaries, but faint to absent in the antral follicles of UCP1-TG mice. In conclusion, the reduction in circulating IGF1 levels due to the ectopic expression of UCP1 is associated with reduced immunostaining of the IRS1-PI3/AKT pathway, which may negatively affect ovarian follicle development and ovulation.     

Experimental trends of NO in circulating fluidized bed combustion

Experimental trends for the dependence of CO, NO and N₂O emissions on bed temperature and oxygen concentration in circulating fluidized bed combustion (CFB) are presented. The main focus is on the nitrogen emission formation in the lower furnace area. A test campaign including seven tests with a laboratory scale CFB test rig were carried out to produce appropriate data of the phenomena. These experiments show that NO emissions above the dense bed decrease with decreasing temperature or oxygen concentration. Instead, N₂O emissions increase when the bed temperature is decreased and decrease when the oxygen concentration is decreased. These trends can partly be explained by heterogeneous reactions between NO and char, since decrease in temperature or oxygen concentration increases the bed char inventory. However, oxygen and temperature also affect directly on NO emissions. Correlations for the CO, NO, N₂O, NH₃ and HCN concentrations at the exit of dense bed were developed. This type of correlations can, among other things, be applied as boundary conditions to the more sophisticated CFD models that are usually applied to modelling of diluted part of the furnace. CFD modelling of the dense bed area is complicated and accuracy is not sufficient, thus simplified experimental correlations can aid in the development of furnace design towards better emission performance.     

In vitro and in vivo Staining Characteristics of Small,Fluorescent, Aβ42‐Binding D‐Enantiomeric Peptides in Transgenic AD Mouse Models

Plaque visualisation : We identified three different D ‐enantiomeric peptides that bind to Alzheimer's amyloid β (Aβ1‐42). As there is currently no definitive pre‐mortem diagnosis for Alzheimer's disease, we investigated the peptides' suitability as molecular probes for in vivo imaging in transgenic mouse models.

     

Key to analyte migration and retention in electrochromatography

This work identifies electrical field-induced concentration polarization (CP) as a key physical mechanism influencing the retention behavior of charged analytes in electrochromatography with fixed beds of porous adsorbent particles. Due to an insufficient screening of intraparticle surface charge, under most general conditions the porous (permeable) particles become charge-selective. CP is caused by coupled mass and charge transport normal to the charge-selective external surface of the permeable particles, which leads to concentration gradients of ionic species in the adjoining interparticle electrolyte solution. Cation-exchange (cation-selective) particles were employed to investigate the influence of applied voltage on the retention factor of counterionic, i.e., positively charged, analytes. It is demonstrated by macroscopic retention data and microscopic studies resolving the CP phenomenon on a particle scale that the dependence of CP on electrical field and mobile-phase ionic strengths is directly reflected in concomitant changes of analyte retention. The CP zones that develop at the interface between interparticle and intraparticle pore space are recognized by charged, but not electroneutral analytes while entering or leaving the particles. The intensity of these convective-diffusion boundary layers (CP zones) depends on the applied field strength and charge selectivity of a particle. Thus, it is the charge-selective transport between the interparticle and intraparticle pore space in packed beds that prevails under typical experimental conditions in electrochromatography and that forms the physical basis for a general electrical field dependence of the retention factor of charged analytes.     

Polycyclic aromatic hydrocarbons (PAH) in various types of tea

For the analysis of the 16 PAH (EFSA-PAH), which are classified as priority for different food groups by the Scientific Committee on Food (SCF) and the Joint FAO/WHO Experts Committee on Food Additives (JECFA) in tea, a sensitive analytical Fast-GC/HRMS method was used. The sample preparation included accelerated solvent extraction (ASE) and the highly automated clean up steps, gel permeation chromatography and solid phase extraction. The analytical parameters, limit of detection (0.01–0.02 μg/kg) and limit of quantification (0.03–0.06 μg/kg), were determined. The repeatability (RSD, n = 3) of different PAH in fruit tea ranged from 0.1 to 11%. It was observed that the total contents of the 16 PAH in tea samples ranged from 14 to 2,662 μg/kg. The analysed tea samples showed an increasing presence of PAH in the following order: herbal and fruit tea (n = 7) < black tea (n = 11) < green tea (n = 11) < white tea (n = 3) < mate-tea (n = 8). The correlation coefficient (R) between BaP and the sum of the 16 EFSA-PAH was established considering the contamination amount in all the 40 tea samples analysed.     

Furan and Methylfurans in Foods: An Update on Occurrence,Mitigation, and Risk Assessment

The acceptance of many foods is related to traditional cooking practices, which create taste and texture and are important to digestibility, preservation, and the reduction of foodborne illnesses. A wide range of compounds are formed during the cooking of foods, a number of these have been shown to lead to adverse effects in classical toxicological models and are known as food processing contaminants (FPC). It is essential that the presence and effects of such compounds alone and in combination within the diet are understood such that proportionate risk management measures can be developed, while taking a holistic view across the whole value chain. Furan and alkylfurans (principally 2‐ and 3‐methylfuran) are highly volatile FPC, which are formed in a wide range of foods at low amounts. The focus of research to‐date has been on those foods, which have been identified to be most consequential in terms of being sources of exposure, namely jarred and canned foods for infants and young children (meals and drinks) and coffee (roast and ground, soluble). This report presents (i) new industry data on the occurrence of furan and methylfurans in selected food categories following previous coffee studies, (ii) the most salient parameters that impact furan formation, and (iii) aspects of importance for the risk assessment.