Use of DNA repair enzymes in electrochemical detection of damage to DNA bases in vitro and in cells

Electrochemical measurements at mercury or solid amalgam electrodes offer a highly sensitive detection of DNA strand breaks. On the other hand, electrochemical detection of damage to DNA bases at any electrode is usually much less sensitive. In this paper, we propose a new voltammetric method for the detection of the DNA base damage based on enzymatic conversion of the damaged DNA bases to single-strand breaks (ssb), single-stranded (ss) DNA regions, or both. Supercoiled DNA exposed to UV light was specifically cleaved by T4 endonuclease V, an enzyme recognizing pyrimidine dimers, the major products of photochemical DNA damage. Apurinic sites (formed in dimethyl sulfate-modified DNA) were determined after treating the DNA with E. coli exonuclease III, an enzyme introducing ssb at the abasic sites and degrading one of the DNA strands. The ssb or ssDNA regions, or both, were detected by adsorptive transfer stripping alternating current voltammetry at the mercury electrode. This technique offers much better sensitivity and selectivity of DNA base damage detection than any other electrochemical method. It is not limited to DNA damage in vitro, but it can detect also DNA base damage induced in living bacterial cells.     

Portable device for characterizing the angular response of UV spectroradiometers

This paper introduces a device that was developed to measure the angular response of UV spectroradiometers in the field. This device is designed to be used at the operating position of spectroradiometers; thus the derived angular response also includes any effects from imperfect leveling of the diffuser and corresponds to the actual operational angular response. The design and characterization of the device and the results from its application on 11 different spectroradiometers that operate at different European UV stations are presented. Various sources of uncertainties that were identified result in a combined uncertainty in determining the angular response, which ranges between approximately 1.5% and 10%, depending on the incidence angle and the characteristics of the diffuser. For the 11 instruments, the error in reporting the diffuse irradiance ranges between 2% and - 13%, assuming isotropic distribution of the downwelling radiances.     

Shape memory effect in Cu nanowires

A rubber-like pseudoelastic behavior is discovered in single-crystalline face-centered-cubic (FCC) Cu nanowires in atomistic simulations. Nonexistent in bulk Cu, this phenomenon is associated primarily with a reversible crystallographic lattice reorientation driven by the high surface-stress-induced internal stresses due to high surface-to-volume ratios at the nanoscale level. The temperature-dependence of this behavior leads to a shape memory effect (SME). Under tensile loading and unloading, the nanowires exhibit recoverable strains up to over 50%, well beyond the typical recoverable strains of 5-8% for most bulk shape memory alloys (SMAs). This behavior is well-defined for wires between 1.76 and 3.39 nm in size over the temperature range of 100-900 K.     

Review of New Directions in Sex Therapy: Innovations and Alternatives.

The impetus for this book grew out of the editor's dissatisfaction with approaches to sex therapy that overemphasize the technical aspects of sexual functioning and thus fail to appreciate the interpersonal relationships in which sexual problems arise. A central thesis of this book is that clinicians need to be aware of how sexuality is always a "product" of a complex set of power relations. The book provides up-to-date coverage of the theoretical and research literature in the field of sex therapy, while the contributors provide challenges to reductive, biomedical explanations of clients' sexual intimacy-related concerns, and they offer many practical, insightful, and helpful suggestions. The book is relevant to sex therapists, but it would also be a valuable resource for counselors and faculty teaching graduate-level courses in sexuality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Superhydrophobic, hierarchical, plasma-nanotextured polymeric microchannels sustaining high-pressure flows

We fabricated superhydrophilic and superhydrophobic polymeric microfluidic devices with controlled hierarchical, random roughness, using plasma processing. We implemented a dye staining technique to visually demonstrate the persistence of the superhydrophobic state under flow for pressures in excess of 2.5 bar inside the microchannel. We further confirmed the stability of superhydrophobicity by pressure drop measurements, friction factor and slip length calculations under laminar flow conditions. We also compared identical rough superhydrophilic and superhydrophobic microchannels showing reduced pressure drop in the latter by as much as 22 %. Plasma etching and simultaneous nanotexturing (followed by optional fluorocarbon plasma deposition) are thus shown as an easy-to-implement method for attaining robust Cassie-state against high-pressure microchannel flows.     

Renal Injuries after Cardiac Arrest: A Morphological Ultrastructural Study

Background: This study aims to investigate the probable lesions and injuries induced in the renal tissue after a cardiac arrest. The renal ischemia–reperfusion model in cardiac arrest describes the effects of ischemia in the kidneys, alongside a whole-body ischemia–reperfusion injury. This protocol excludes ischemic conditions caused by surgical vascular manipulation, venous injury or venous congestion. Methods: For the experimental study, 24 swine were subjected to cardiac arrest. Seven minutes later, the cardiopulmonary resuscitation technique was performed for 5 min. Afterwards, advanced life support was provided. The resuscitated swine consisted one group and the non-resuscitated the other. Tissue samples were obtained from both groups for light and electron microscopy evaluation. Results: Tissue lesions were observed in the tubules, parallel to destruction of the microvilli, reduction in the basal membrane invaginations, enlarged mitochondria, cellular vacuolization, cellular apoptosis and disorganization. In addition, fusion of the podocytes, destruction of the Bowman’s capsule parietal epithelium and abnormal peripheral urinary space was observed. The damage appeared more extensive in the non-resuscitated swine group. Conclusions: Acute kidney injury is not the leading cause of death after cardiac arrest. However, evidence suggests that the kidney damage after a cardiac arrest should be highly considered in the prognosis of the patients’ health outcome.     

The 1-Fixed-Endpoint Path Cover Problem is Polynomial on Interval Graphs

We consider a variant of the path cover problem, namely, the k-fixed-endpoint path cover problem, or kPC for short, on interval graphs. Given a graph G and a subset T\mathcal{T} of k vertices of V(G), a k-fixed-endpoint path cover of G with respect to T\mathcal{T} is a set of vertex-disjoint paths ℘ that covers the vertices of G such that the k vertices of T\mathcal{T} are all endpoints of the paths in ℘. The kPC problem is to find a k-fixed-endpoint path cover of G of minimum cardinality; note that, if T\mathcal{T} is empty the stated problem coincides with the classical path cover problem. In this paper, we study the 1-fixed-endpoint path cover problem on interval graphs, or 1PC for short, generalizing the 1HP problem which has been proved to be NP-complete even for small classes of graphs. Motivated by a work of Damaschke (Discrete Math. 112:49–64, 1993), where he left both 1HP and 2HP problems open for the class of interval graphs, we show that the 1PC problem can be solved in polynomial time on the class of interval graphs. We propose a polynomial-time algorithm for the problem, which also enables us to solve the 1HP problem on interval graphs within the same time and space complexity.     

Comparative analysis of the fatty acid and sterol profiles of widely consumed Mediterranean crustacean species

Comparative analysis of FA, NL and sterol profiles in the Nephropsnorvegicus (langoustine), Palinurusvulgaris (lobster) and Penaeuskerathurus (shrimp) muscle and cephalothorax showed that C16:0, C16:1ω-7, C18:0, C18:1ω-9, C20:4ω-6, EPA and DHA were found to be their major FA. Highest EPA occurred in langoustine muscle TL, DHA in both shrimp tissues TL while C20:4ω-6 in lobster muscle and cephalothorax TL. Muscle and cephalothorax NL consisted mainly of sterols (42.5–54.4% and 13.7–43.1%) and triacylglycerols (35.4–45.8% and 44.6–59.4%). Cholesterol was the major sterol (70.90–98.58% and 97.10–98.31% of total sterols in muscle and cephalothorax respectively) followed by avenasterol (0.18–20.32% and 0.07–0.70%) and β-sitosterol (0.29–7.30% and 0.23–0.75%). Lower concentrations of brassicasterol, stigmasterol, Δ7-stigmasterol, campesterol and campestanol were also found. The examined crustaceans muscle (edible part) was found to be a good ω-3 PUFA source for the consumers, while the cephalothorax (which is usually discarded) could be used effectively as a source for ω-3 PUFA production.     

Ferromagnetic coupling of Fe3+-VO-Fe3+polarons in Fe-doped ZnO

Room temperature ferromagnetic Fe-doped ZnO with hexagonal wurtzite structure was synthesized by a hydrothermal method under 4 T high pulsed magnetic field. Detailed studies were carried out to survey the effect of magnetic field on morphological, structural and magnetic properties of samples. The results showed that the concentration of oxygen vacancies (VOs) and amount of Fe³⁺ doping in ZnO were improved due to the high magnetic field processing. It proposed that the inherent exchange interaction is mediated by magnetic ions (Fe³⁺) through VOs assist to produce bound magnetic polorans (BMPs), which is responsible for RTFM in Fe-doped ZnO matrix.