The Effect of Curvature on lnterfacial Tension in Liquid Systems Measured by Homogeneous Nucleation

Interfacial tensions were measured as a function of the curvature of the interface in liquid ternary, two-phase systems at 25 °c. The systems were chosen so that the phase on the concave side of the interface ( = the inner phase = the droplet) consisted mainly of one of the components. When this compound is a nonpolar or polar, non-hydrogen bonding liquid the interfacial tension is almost independent of curvature, but when the inner phase is a hydrogen bonding liquid the interfacial tension a varies with the radius of curvature. The experimental method consisted in determining the time taken for a supersaturated solution to become turbid, this time being of the order of 1 millisecond

Effects of package and storage conditions on the keeping quality of Perlette grapes

Einfluß der Verpackungs- und Lagerungsbedingungen auf die Haltbarkeit von Perlette-TraubenUm die Verluste zwischen Ernte und Verkauf von Perlette-Trauben zu verringern, wurde jeweils 1/4 eines SO2-Spenders („Dual Release" SO2 generator) in die 2 kg Trauben fassenden Polyäthylenbeutel gelegt; die Verpackungsbeutel waren mit Perforationen versehen, die 0,56; 0,84; 1,12; 1,40 und 1,68 % der Folienfläche ausmachten. Die gefüllten Beutel wurden bei 5, 15, 25, 30 und 35 °C (Freilandtemperatur) in belüftete 2-kg-Kartons aus Wellpappe verpackt und 60 d lang kühl gelagert (0-3 °C). Bei der Verkostung wurden die Trauben mit einer Verpackungstemperatur von 35 °C und 1,12%iger Perforation der Verpackungsqeutel am besten beurteilt. Die niedrigste Verpackungstemperatur (5 °C) und der niedrigste Perforationsgrad (0,56 %) verringerten beide den physiologischen Gewichtsverlust (PLW) und das Abfallen der Beeren am stärksten. PLW nahm mit der Dauer der Lagerung zu. Bis zu einer Lagerungsdauer von 40 d in zu 0,56 %, 0,85 % und 1,12 % perforierten Beuteln trat keine Beerenfäulnis auf; diese war jedoch auch bei erhöhter Perforation noch zu vernachlässigen. Die höchsten Mostgewichte wurden bei Verpakkungstemperaturen von 30 oder 35 °C nach 40tägiger Lagerung festgestellt; danach nahm das Mostgewicht ab. Die höchsten Säurewerte wurden bei Verpackungstemperaturen von 25 und 35 °C nach einer Lagerungsdauer von 40 d, bei 15 und 30 °C nach 60 d ermittelt. Demzufolge können PerletteTrauben durch beigepackte SO2-Spender in Folienbeuteln, die zu 1,12 % perforiert sind und Verpacken bei 35 °C bis zu 40 d erfolgreich gelagert werden

Comprehensive analysis of common mitochondrial DNA variants and colorectal cancer risk.

Several lines of evidence implicate mitochondrial dysfunction in the development of cancer. To test the hypothesis that common mtDNA variation influences the risk of colorectal cancer (CRC), we genotyped 132 tagging mtDNA variants in a sample of 2854 CRC cases and 2822 controls. The variants examined capture approximately 80% of mtDNA common variation (excluding the hypervariable D-loop). We first tested for single marker associations; the strongest association detected was with A5657G (P=0.06). Overall the distribution of association P-values was consistent with a null distribution. Next, we classified individuals into the nine common European haplogroups and compared their distribution in cases and controls. This analysis also provided no evidence of an association between mitochondrial variation and CRC risk. In conclusion, our results provide little evidence that mitochondrial genetic background plays a role in modifying an individual's risk of developing CRC

Asexuality: Classification and characterization

This is a post-print version of the article. The official published version can be obtaineed at the link below.The term “asexual” has been defined in many different ways and asexuality has received very little research attention. In a small qualitative study (N = 4), individuals who self-identified as asexual were interviewed to help formulate hypotheses for a larger study. The second larger study was an online survey drawn from a convenience sample designed to better characterize asexuality and to test predictors of asexual identity. A convenience sample of 1,146 individuals (N = 41 self-identified asexual) completed online questionnaires assessing sexual history, sexual inhibition and excitation, sexual desire, and an open-response questionnaire concerning asexual identity. Asexuals reported significantly less desire for sex with a partner, lower sexual arousability, and lower sexual excitation but did not differ consistently from non-asexuals in their sexual inhibition scores or their desire to masturbate. Content analyses supported the idea that low sexual desire is the primary feature predicting asexual identity

What are we measuring? A critique of range of motion methods currently in use for Dupuytren's disease and recommendations for practice

Background: Range of motion is the most frequently reported measure used in practice to evaluate outcomes. A goniometer is the most reliable tool to assess range of motion yet, the lack of consistency in reporting prevents comparison between studies. The aim of this study is to identify how range of motion is currently assessed and reported in Dupuytren’s disease literature. Following analysis recommendations for practice will be made to enable consistency in future studies for comparability. This paper highlights the variation in range of motion reporting in Dupuytren’s disease. Methods: A Participants, Intervention, Comparison, Outcomes and Study design format was used for the search strategy and search terms. Surgery, needle fasciotomy or collagenase injection for primary or recurrent Dupuytren’s disease in adults were included if outcomes were monitored using range of motion to record change. A literature search was performed in May 2013 using subject heading and free-text terms to also capture electronic publications ahead of print. In total 638 publications were identified and following screening 90 articles met the inclusion criteria. Data was extracted and entered onto a spreadsheet for analysis. A thematic analysis was carried out to establish any duplication, resulting in the final range of motion measures identified. Results: Range of motion measurement lacked clarity, with goniometry reportedly used in only 43 of the 90 studies, 16 stated the use of a range of motion protocol. A total of 24 different descriptors were identified describing range of motion in the 90 studies. While some studies reported active range of motion, others reported passive or were unclear. Eight of the 24 categories were identified through thematic analysis as possibly describing the same measure, ‘lack of joint extension’ and accounted for the most frequently used. Conclusions: Published studies lacked clarity in reporting range of motion, preventing data comparison and meta-analysis. Percentage change lacks context and without access to raw data, does not allow direct comparison of baseline characteristics. A clear description of what is being measured within each study was required. It is recommended that range of motion measuring and reporting for Dupuytren’s disease requires consistency to address issues that fall into 3 main categories:- Definition of terms Protocol statement Outcome reportin

A Microhomology-Mediated Break-Induced Replication Model for the Origin of Human Copy Number Variation

Chromosome structural changes with nonrecurrent endpoints associated with genomic disorders offer windows into the mechanism of origin of copy number variation (CNV). A recent report of nonrecurrent duplications associated with Pelizaeus-Merzbacher disease identified three distinctive characteristics. First, the majority of events can be seen to be complex, showing discontinuous duplications mixed with deletions, inverted duplications, and triplications. Second, junctions at endpoints show microhomology of 2–5 base pairs (bp). Third, endpoints occur near pre-existing low copy repeats (LCRs). Using these observations and evidence from DNA repair in other organisms, we derive a model of microhomology-mediated break-induced replication (MMBIR) for the origin of CNV and, ultimately, of LCRs. We propose that breakage of replication forks in stressed cells that are deficient in homologous recombination induces an aberrant repair process with features of break-induced replication (BIR). Under these circumstances, single-strand 3′ tails from broken replication forks will anneal with microhomology on any single-stranded DNA nearby, priming low-processivity polymerization with multiple template switches generating complex rearrangements, and eventual re-establishment of processive replication

Mutability and Importance of a Hypermutable Cell Subpopulation that Produces Stress-Induced Mutants in Escherichia coli

In bacterial, yeast, and human cells, stress-induced mutation mechanisms are induced in growth-limiting environments and produce non-adaptive and adaptive mutations. These mechanisms may accelerate evolution specifically when cells are maladapted to their environments, i.e., when they are are stressed. One mechanism of stress-induced mutagenesis in Escherichia coli occurs by error-prone DNA double-strand break (DSB) repair. This mechanism was linked previously to a differentiated subpopulation of cells with a transiently elevated mutation rate, a hypermutable cell subpopulation (HMS). The HMS could be important, producing essentially all stress-induced mutants. Alternatively, the HMS was proposed to produce only a minority of stress-induced mutants, i.e., it was proposed to be peripheral. We characterize three aspects of the HMS. First, using improved mutation-detection methods, we estimate the number of mutations per genome of HMS-derived cells and find that it is compatible with fitness after the HMS state. This implies that these mutants are not necessarily an evolutionary dead end, and could contribute to adaptive evolution. Second, we show that stress-induced Lac+ mutants, with and without evidence of descent from the HMS, have similar Lac+ mutation sequences. This provides evidence that HMS-descended and most stress-induced mutants form via a common mechanism. Third, mutation-stimulating DSBs introduced via I-SceI endonuclease in vivo do not promote Lac+ mutation independently of the HMS. This and the previous finding support the hypothesis that the HMS underlies most stress-induced mutants, not just a minority of them, i.e., it is important. We consider a model in which HMS differentiation is controlled by stress responses. Differentiation of an HMS potentially limits the risks of mutagenesis in cell clones

Gene array of VHL mutation and hypoxia shows novel hypoxia-induced genes and that cyclin D1 is a VHL target gene

Gene expression analysis was performed on a human renal cancer cell line (786-0) with mutated VHL gene and a transfectant with wild-type VHL to analyse genes regulated by VHL and to compare with the gene programme regulated by hypoxia. There was a highly significant concordance of the global gene response to hypoxia and genes suppressed by VHL. Cyclin D1 was the most highly inducible transcript and 14-3-3 epsilon was downregulated. There were some genes regulated by VHL but not hypoxia in the renal cell line, suggesting a VHL role independent of hypoxia. However in nonrenal cell lines they were hypoxia regulated. These included several new pathways regulated by hypoxia, including RNase 6PL, collagen type 1 alpha 1, integrin alpha 5, ferritin light polypeptide, JM4 protein, transgelin and L1 cell adhesion molecule. These were not found in a recent SAGE analysis of the same cell line. Hypoxia induced downregulation of Cyclin D1 in nonrenal cells via an HIF independent pathway. The selective regulation of Cyclin D1 by hypoxia in renal cells may therefore contribute to the tissue selectivity of VHL mutation

Covalent enzyme coupling on cellulose acetate membranes for glucose sensor development

International audienceMethods for immobilizing glucose oxidase (GOx) on cellulose acetate (CA) membranes are compared. The optimal method involves covalent coupling of bovine serum albumin (BSA) to CA membrane and a subsequent reaction of the membrane with GOx, which has previously been activated with an excess of p-benzoquinone. This coupling procedure is fairly reproducible and allows the preparation of thin membranes (5-20 µm) showing high surface activities (1-3 U/cm2) which are stable over a period of 1-3 months. Electrochemical and radiolabeling experiments show that enzyme inactivation as a result of immobilization is negligible. A good correlation between surface activity of membranes and their GOx load is observed

Design and in vitro studies of a needle-type glucose sensor for subcutaneous monitoring

International audienceA new miniaturized glucose oxidase based needle-type glu¬ cose mlcrosensor has been developed for subcutaneous glu¬ cose monitoring. The sensor Is equivalent In shape and size to a 26-gauge needle (0.45-mm o.d.) and can be Implanted with ease without any Incision. The novel configuration greatly facilitates the deposition of enzyme and polymer films so that sensors with characteristics suitable for In vivo use (upper limit of linear range > 15 mM, response time 60%). The sensor response is largely Independent of ox¬ ygen tension In the normal physiological range. It also ex¬ hibits good selectivity against common interferences except for the exogenous drug acetaminophen