2,110 research outputs found

    Switching the aptamer attachment geometry can dramatically alter the signalling and performance of electrochemical aptamer-based sensors

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    Electrochemical aptamer-based (EAB) sensors, composed of an electrode-bound DNA aptamer with a redox reporter on the distal end, offer the promise of high-frequency, real-time molecular measurements in complex sample matrices and even in vivo. Here we assess the extent to which switching the aptamer terminus that is electrode-bound and the one that is redox-reporter-modified affects the performance of these sensors. Using sensors against doxorubicin, cocaine, and vancomycin as our test beds, we find that both signal gain (the relative signal change seen in the presence of a saturating target) and the frequency dependence of gain depend strongly on the attachment orientation, suggesting that this easily investigated variable is a worthwhile parameter to optimize in the design of new EAB sensors

    Descent of Equivalences and Character Bijections

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    Categorical equivalences between block algebras of finite groups—such as Morita and derived equivalences—are well known to induce character bijections which commute with the Galois groups of field extensions. This is the motivation for attempting to realise known Morita and derived equivalences over non-splitting fields. This article presents various results on the theme of descent to appropriate subfields and subrings. We start with the observation that perfect isometries induced by a virtual Morita equivalence induce isomorphisms of centres in non-split situations and explain connections with Navarro’s generalisation of the Alperin–McKay conjecture. We show that Rouquier’s splendid Rickard complex for blocks with cyclic defect groups descends to the non-split case. We also prove a descent theorem for Morita equivalences with endopermutation source

    Anticancer Gene Transfer for Cancer Gene Therapy

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    Gene therapy vectors are among the treatments currently used to treat malignant tumors. Gene therapy vectors use a specific therapeutic transgene that causes death in cancer cells. In early attempts at gene therapy, therapeutic transgenes were driven by non-specific vectors which induced toxicity to normal cells in addition to the cancer cells. Recently, novel cancer specific viral vectors have been developed that target cancer cells leaving normal cells unharmed. Here we review such cancer specific gene therapy systems currently used in the treatment of cancer and discuss the major challenges and future directions in this field

    Impaired decisional impulsivity in pathological videogamers

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    Abstract Background Pathological gaming is an emerging and poorly understood problem. Impulsivity is commonly impaired in disorders of behavioural and substance addiction, hence we sought to systematically investigate the different subtypes of decisional and motor impulsivity in a well-defined pathological gaming cohort. Methods Fifty-two pathological gaming subjects and age-, gender- and IQ-matched healthy volunteers were tested on decisional impulsivity (Information Sampling Task testing reflection impulsivity and delay discounting questionnaire testing impulsive choice), and motor impulsivity (Stop Signal Task testing motor response inhibition, and the premature responding task). We used stringent diagnostic criteria highlighting functional impairment. Results In the Information Sampling Task, pathological gaming participants sampled less evidence prior to making a decision and scored fewer points compared with healthy volunteers. Gaming severity was also negatively correlated with evidence gathered and positively correlated with sampling error and points acquired. In the delay discounting task, pathological gamers made more impulsive choices, preferring smaller immediate over larger delayed rewards. Pathological gamers made more premature responses related to comorbid nicotine use. Greater number of hours played also correlated with a Motivational Index. Greater frequency of role playing games was associated with impaired motor response inhibition and strategy games with faster Go reaction time. Conclusions We show that pathological gaming is associated with impaired decisional impulsivity with negative consequences in task performance. Decisional impulsivity may be a potential target in therapeutic management

    Will the Playstation generation become better endoscopic surgeons?

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    A frequently heard comment is that the current "Playstation generation" will have superior baseline psychomotor skills. However, research has provided inconsistent results on this matter. The purpose of this study was to investigate whether the "Playstation generation" shows superior baseline psychomotor skills for endoscopic surgery on a virtual reality simulator. The 46 study participants were interns (mean age 24 years) of the department of surgery and schoolchildren (mean age 12.5 years) of the first year of a secondary school. Participants were divided into four groups: 10 interns with videogame experience and 10 without, 13 schoolchildren with videogame experience and 13 without. They performed four tasks twice on a virtual reality simulator for basic endoscopic skills. The one-way analysis of variance (ANOVA) with post hoc test Tukey-Bonferroni and the independent Student's t test were used to determine differences in mean scores. Interns with videogame experience scored significantly higher on total score (93 vs. 74.5; p=0.014) compared with interns without this experience. There was a nonsignificant difference in mean total scores between the group of schoolchildren with and those without videogame experience (61.69 vs. 55.46; p=0.411). The same accounts for interns with regard to mean scores on efficiency (50.7 vs. 38.9; p=0.011) and speed (18.8 vs. 14.3; p=0.023). In the group of schoolchildren, there was no statistical difference for efficiency (32.69 vs. 27.31; p=0.218) or speed (13.92 vs. 13.15; p=0.54). The scores concerning precision parameters did not differ for interns (23.5 vs. 21.3; p=0.79) or for schoolchildren (mean 15.08 vs. 15; p=0.979). Our study results did not predict an advantage of videogame experience in children with regard to superior psychomotor skills for endoscopic surgery. However, at adult age, a difference in favor of gaming is present. The next generation of surgeons might benefit from videogame experience during their childhoo

    Radio emission from Supernova Remnants

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    The explosion of a supernova releases almost instantaneously about 10^51 ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from a SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critical discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analyzing the prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure

    Polymorphisms in Toll-like receptor genes influence antibody responses to cytomegalovirus glycoprotein B vaccine

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    <p>Abstract</p> <p>Background</p> <p>Congenital Cytomegalovirus (CMV) infection is an important medical problem that has yet no current solution. A clinical trial of CMV glycoprotein B (gB) vaccine in young women showed promising efficacy. Improved understanding of the basis for prevention of CMV infection is essential for developing improved vaccines.</p> <p>Results</p> <p>We genotyped 142 women previously vaccinated with three doses of CMV gB for single nucleotide polymorphisms (SNPs) in TLR 1-4, 6, 7, 9, and 10, and their associated intracellular signaling genes. SNPs in the platelet-derived growth factor receptor (PDGFRA) and integrins were also selected based on their role in binding gB. Specific SNPs in TLR7 and IKBKE (inhibitor of nuclear factor kappa-B kinase subunit epsilon) were associated with antibody responses to gB vaccine. Homozygous carriers of the minor allele at four SNPs in TLR7 showed higher vaccination-induced antibody responses to gB compared to heterozygotes or homozygotes for the common allele. SNP rs1953090 in IKBKE was associated with changes in antibody level from second to third dose of vaccine; homozygotes for the minor allele exhibited lower antibody responses while homozygotes for the major allele showed increased responses over time.</p> <p>Conclusions</p> <p>These data contribute to our understanding of the immunogenetic mechanisms underlying variations in the immune response to CMV vaccine.</p
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