Genetic polymorphism of the human sex hormone-binding globulin: evidence of an isoelectric focusing variant with normal androgen-binding affinities

Human sex hormone-binding globulin (hSHBG) is a plasma glycoprotein composed of two identical subunits. The protein, which has high affinity for testosterone and estradiol has been purified to homogeneity. In this study we have investigated, on neuraminidase-treated serum samples, the presence of genetic variations of hSHBG by polyacrylamide gel isoelectric focusing (IEF). Based on IEF analyses of 110 serum samples from adult Mexican individuals we have identified two distinct IEF-patterns. The most frequent phenotype (95.45%) was characterized by two IEF-bands with pIs of 6.50 and 6.63, respectively. In five serum samples, a different 4-band pattern with pIs of 6.50, 6.63, 6.70 and 6.76 was identified. Family studies showed that this pattern was genetically determined. The frequency of this variant was 4.55%, and the observed phenotypes were consistent with the expression of an autosomal genetic system. The estimated gene frequencies for both alleles were shown to be in genetic equilibrium. Affinity constants, binding kinetics and serum concentrations of hSHBG from individuals having a 4-band pattern were similar to those obtained in individuals with a 2-band pattern, thus suggesting that the mechanism responsible for the generation of polymorphic variants of hSHBG reported herein did not involve the steroid binding site of the molecule. These findings may be of broad interest, as other serum binding proteins express genetic variants, which may permit their further structural and functional subclassification.     

Melatonin attenuates the effects of sub-acute administration of lead on kidneys in rats without altering the lead-induced reduction in nitric oxide

Exposure to lead induces oxidative stress and renal damage. Although most forms of oxidative stress are characterized by simultaneous elevation of nitrogen and oxidative species, lead-induced oxidative stress is unusual in that it is associated with a reduction in nitric oxide (NO) levels in the kidney. The role of NO in kidney injury is controversial; some studies suggest that it is associated with renal injury, whereas others show that it exerts protective effects. Concentration-dependent effects have also been proposed, linking low levels with vasodilatation and high levels with toxicity. The aim of this study was to evaluate the effects of melatonin co-exposure on the lead-induced reduction in renal NO levels. We found that sub-acute intraperitoneal administration of 10 mg/kg/day of lead for 15 days induced toxic levels of lead in the blood and caused renal toxicity (pathological and functional). Under our experimental conditions, lead induced an increase in lipid peroxidation and a decrease in NO. Melatonin co-treatment decreased lead-induced oxidative stress (peroxidation level) and toxic effects on kidneys without altering the lead-induced reduction in renal NO. These results suggest that, in our experimental model, the reduction in renal NO levels by lead exposure is not the only responsible factor for lead-induced kidney damage.     

Fluorine‐Free Noble Salt Anion for High‐Performance All‐Solid‐State Lithium–Sulfur Batteries

Amongst post‐Li‐ion battery technologies, lithium–sulfur (Li–S) batteries have captured an immense interest as one of the most appealing devices from both the industrial and academia sectors. The replacement of conventional liquid electrolytes with solid polymer electrolytes (SPEs) enables not only a safer use of Li metal (Li°) anodes but also a flexible design in the shape of Li–S batteries. However, the practical implementation of SPEs‐based all‐solid‐state Li–S batteries (ASSLSBs) is largely hindered by the shuttling effect of the polysulfide intermediates and the formation of dendritic Li° during the battery operation. Herein, a fluorine‐free noble salt anion, tricyanomethanide [C(CN)₃^?, TCM^?], is proposed as a Li‐ion conducting salt for ASSLSBs. Compared to the widely used perfluorinated anions {e.g., bis(trifluoromethanesulfonyl)imide anion, [N(SO₂CF₃)₂)]^?, TFSI^?}, the LiTCM‐based electrolytes show decent ionic conductivity, good thermal stability, and sufficient anodic stability suiting the cell chemistry of ASSLSBs. In particular, the fluorine‐free solid electrolyte interphase layer originating from the decomposition of LiTCM exhibits a good mechanical integrity and Li‐ion conductivity, which allows the LiTCM‐based Li–S cells to be cycled with good rate capability and Coulombic efficiency. The LiTCM‐based electrolytes are believed to be the most promising candidates for building cost‐effective and high energy density ASSLSBs in the near future.     

Efficient Exploration of the Composition Space in Ternary Organic Solar Cells by Combining High‐Throughput Material Libraries and Hyperspectral Imaging

Organic solar cells based on ternary active layers can lead to higher power conversion efficiencies than corresponding binaries, and improved stability. The parameter space for optimization of multicomponent systems is considerably more complex than that of binaries, due to both, a larger number of parameters (e.g., two relative compositions rather than one) and intricate morphology–property correlations. Most experimental reports to date reasonably limit themselves to a relatively narrow subset of compositions (e.g., the 1:1 donor/s:acceptor/s trajectory). This work advances a methodology that allows exploration of a large fraction of the ternary phase space employing only a few (<10) samples. Each sample is produced by a designed sequential deposition of the constituent inks, and results in compositions gradients with ≈5000 points/sample that cover about 15%–25% of the phase space. These effective ternary libraries are then colocally imaged by a combination of photovoltaic techniques (laser and white light photocurrent maps) and spectroscopic techniques (Raman, photoluminescence, absorption). The generality of the methodology is demonstrated by investigating three ternary systems, namely PBDB‐T:ITIC:PC₇₀BM, PTB7‐Th:ITIC:PC₇₀BM, and P3HT:O‐IDFBR:O‐IDTBR. Complex performance‐structure landscapes through the ternary diagram as well as the emergence of several performance maxima are discovered.     

Oral Candida colonization in patients with chronic periodontitis. Is there any relationship?

Background

Candida can be implicated in the pathology of chronic periodontitis.

Influence of the position on the bicycle on the frontal area in road cyclists

The aims of the present study were to determine whether the estimations of the frontal area of the combined cyclist-bicycle (APCB) obtained with the Heil's non-logarithmic prediction equations (NPE) in the stem position (SP), brake hoods position (BHP) and drops position (DP) are comparable to the measured APCB with the computerized planimetry (CP) method, and to analyse with the CP method and the NPE the influence of the body position on the APCB. Nineteen participants competing in the Spanish Road Cycling First division took part in the study. The NPE overestimated the APCB in the BHP and in the DP compared with the measured APCB with the CP method (6.9% and 5.1%, respectively; p<0.05). Significant differences among the three positions were obtained with the CP method. The overestimation of the APCB with the NPE in the BHP and in the DP and the less sensitivity of the NPE to show significant differences between the SP and DP suggest that the NPE are not appropriate to accurately predict the APCB.     

Multiple SNP Markers Reveal Fine-Scale Population and Deep Phylogeographic Structure in European Anchovy (Engraulis encrasicolus L.)

Geographic surveys of allozymes, microsatellites, nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have detected several genetic subdivisions among European anchovy populations. However, these studies have been limited in their power to detect some aspects of population structure by the use of a single or a few molecular markers, or by limited geographic sampling. We use a multi-marker approach, 47 nDNA and 15 mtDNA single nucleotide polymorphisms (SNPs), to analyze 626 European anchovies from the whole range of the species to resolve shallow and deep levels of population structure. Nuclear SNPs define 10 genetic entities within two larger genetically distinctive groups associated with oceanic variables and different life-history traits. MtDNA SNPs define two deep phylogroups that reflect ancient dispersals and colonizations. These markers define two ecological groups. One major group of Iberian-Atlantic populations is associated with upwelling areas on narrow continental shelves and includes populations spawning and overwintering in coastal areas. A second major group includes northern populations in the North East (NE) Atlantic (including the Bay of Biscay) and the Mediterranean and is associated with wide continental shelves with local larval retention currents. This group tends to spawn and overwinter in oceanic areas. These two groups encompass ten populations that differ from previously defined management stocks in the Alboran Sea, Iberian-Atlantic and Bay of Biscay regions. In addition, a new North Sea-English Channel stock is defined. SNPs indicate that some populations in the Bay of Biscay are genetically closer to North Western (NW) Mediterranean populations than to other populations in the NE Atlantic, likely due to colonizations of the Bay of Biscay and NW Mediterranean by migrants from a common ancestral population. Northern NE Atlantic populations were subsequently established by migrants from the Bay of Biscay. Populations along the Iberian-Atlantic coast appear to have been founded by secondary waves of migrants from a southern refuge.