965 research outputs found
The parameter map and velocity on time scales
No full textIn this paper the concepts of a parameter map and velocity on time scales are introduced and investigated some properties. © 2013 H. Kusak and A. Caliskan
Analysis of expression of viral fusion proteins und infection studies with recombinant porcine circovirus
No full textDie Porcinen Circoviren Typ1 (PCV1) und Typ2 (PCV2) gehören zur Familie der
Circoviridae. Sie gelten in Bezug auf die Xenotransplantation als potenzielle
Gefahr für den humanen Empfänger. Zunächst erfolgte die Expression von
Fusionsproteinen der beiden größten offenen Leserahmen, die für die
Replikationsproteine Rep und Rep` sowie das Kapsidprotein Cap kodieren. Die
Expression des vollständigen Kapsidproteins von PCV1 und PCV2 mittels des
Expressionsvektors pGEX als GST-Fusionsprotein war nicht möglich, da ein
Volllängenprodukt nicht nachweisbar war. Die Variation der Expressions-
temperatur, der Zusammensetzung des Nährmediums sowie der Einsatz Protease-
defizienter Bakterienstämme brachte keine Verbesserungen. Als mögliche Ursache
wurde die Codonzusammensetzung des cap-Gens in Betracht gezogen, die für die
Synthese in E.coli ungünstig ist. Durch computergestützte Berechnungen wurde
der Codongebrauch optimiert. Die Expression der modifizierten Fusionsproteine
ergab Produkte der Größe von ca. 42 kDa für PCV1 sowie der Größe 45 kDa für
PCV2, die mit den unlöslichen Zellfraktionen erhalten wurden. Die exprimierten
Cap-Proteine stellten die Grundlage zur Synthese von Cap-spezifischer
Antikörper dar. Durch Herstellung von Fusionsproteinen mit
Fluoreszenzproteinen EGFP bzw. pDsRed konnte die subzelluläre Lokalisation des
Kapsidproteins von PCV1 sowie PCV2, als auch der Replikationsproteine von PCV1
einzeln und in Kombination gezeigt werden. Das Kapsidprotein von PCV1 und von
PCV2 war in den Nukleoli lokalisiert, es zeigte sich keine Abhängigkeit der
Lokalisierung von den Replikationsproteinen. Die Produkte des rep-Gens Rep
sowie Rep` akkumulieren im Nukleus, wobei die Nukleoli ausgespart wurden. Die
subzelluläre Lokalisation änderte sich bei Kotransfektion von Rep und Cap
nicht, demzufolge scheint eine gegenseitige Beeinflussung der Lokalisation
nicht wahrscheinlich. Die Kernloklisation wird durch nukleäre
Lokalisationssignale (NLS) vermittelt, die in sich anschließenden Studien
eingegrenzt wurden (Finsterbusch et al., 2005). Es wurden weiterhin zwei
rekombinante Viren hergestellt, die jeweils am 3’-Ende des rep- bzw. des cap-
Gens ein EGFP-Gen tragen. Nach Transfektion mit dem rekombinanten Virus pRVC2,
welches das an das cap-Gen fusionierte EGFP Protein enthielt, wurde
Fluoreszenz beobachtet. Das Fusionsprotein war in den ersten 24 h nach
Transfektion im Bereich der Nukleoli lokalisiert, danach kam es zur Verteilung
im gesamten Nukleus. Eine produktive Infektion von Zellkulturzellen wurde mit
dem rekombinanten Virus RVC2 nicht beobachtet. Vermutlich ist das
Fusionsprotein nicht in der Lage die natürlichen Funktionen des Kapsidproteins
zu übernehmen. Nach Transfektion des rekombinanten Virus PRVR2, welches das an
das rep-Gen fusionierte EGFP-Protein trug, wurde weder Fluoreszenz noch eine
Infektion nachgewiesen, was darauf hindeutet, dass Manipulationen am Rep-
Protein von PCV1 schlechter kompensiert werden können.The porcine circovirus type 1 (PCV1) and type 2 (PCV2) belong to the family of
Circoviridae. They are regarded as a potential danger for the human recipient
in the context of Xenotransplantation. The present thesis evaluated: 1\. The
expression of fusion proteins of the two largest open reading frames of PCV.
2\. The construction of fluorescent fusion proteins 3\. The construction of
two recombinant circovirus type 1 isolates carrying the gene of green
fluorescent protein fused at the 3’ end of cap or rep. The expression of full
capsid protein of PCV1 and PCV2 using the pGEX expression vector system was
possible. Variation of the expression temperature, the composition of the
culture medium and the use of protease-deficient bacterial strains brought no
improvement. The codon preference of the cap gene was considered as a possible
cause. Therefore the codon preference was analysed by computer calculation and
optimised regions were fused and expressed with the pGEX-expression system.
The subcellular localization of the capsid protein and replication proteins
Rep / Rep’ were analyzed by the construction of fusion proteins with
fluorescent proteins EGFP or pDsRed. Cap of PCV1 and PCV2 were localized in
the nucleoli and showed no dependence of the localization of the replication
proteins Rep / Rep’. The products of the rep gene Rep / Rep’ accumulated in
the nucleus. Cotransfection showed no change in the localization. A reciprocal
influence of the localization was not considered likely. Two recombinant
viruses, which carry an EGFP gene in each case at the 3 ' ends of the rep or
the cap gene were constructed furthermore. After transfection with the
recombinant virus PRVC2, which contained the EGFP gene fused to the cap gene,
fluorescence was observed. The fusion protein was located in the first 24 h
after transfection in the nucleoli. Later, distribution throughout the nucleus
was seen. A productive infection of tissue culture cells with the recombinant
virus RVC2 was not observed. Presumably, the fusion protein is incapable to
take over of the natural functions of the capsid protein. After transfection
of the recombinant virus PRVR2, which contained the EGFP gene fused to the rep
gene neither fluorescent nor infection was observed what points to the fact
that manipulations in the Rep protein can be worse compensated by PCV1
Arslantepe 2011-2012 Yili Kazi Sonuclari. Ilk Tunç çagi'in yeni buluntari
No full textRapporto sui risultati delle campagne di scavo ad Arslantepe degli anni 2011 e 2012
Mechanical and wear performance of A356/Al2O3 aluminum nanocomposites by considering the mechanical milling time and microstructural properties
No full textPurpose: The paper aims to examine the mechanical and wear performance of A356/Al2O3 (alumina) nanocomposites. The correlation between wear performance and the microstructural properties that result from various mechanical milling periods was investigated. Design/methodology/approach: The production of nano alumina reinforced (1 Wt.%) A356 aluminum nanocomposite specimens was carried out using the traditional powder metallurgy method, incorporating three different mechanical milling times (1, 2 and 4 h). Subsequently, mechanical and wear performance assessments were conducted using hardness, compression and pin-on-disc wear tests. Findings: Although the specimens subjected to the most prolonged mechanical milling (4 h) demonstrated superior hardness and compressive strength properties, they exhibited a remarkable weight loss during the wear tests. The traditional evaluation, which supports that the wear performance is generally correlated with hardness, does not consider the microstructural properties. Since the sample milled for 1 h has a moderate microstructure, it showed better wear performance than the sample with higher hardness. Originality/value: The originality of the paper is demonstrated through its evaluation of wear performance, incorporating not only hardness but also the consideration of microstructural properties resulted from mechanical milling. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2023-0031
AUTHOR CORRECTION - ERS International Congress 2019:highlights from Best Abstract awardees
No full textLorna E. Latimer, Marieke Duiverman, Mahmoud I. Abdel-Aziz, Gulser Caliskan, Sara M. Mensink-Bout, Alberto Mendoza-Valderrey, Aurelien Justet, Junichi Omura, Karthi Srikanthan, Jana De Brandt. Breathe 2019; 15: e143–e149. This article from the December 2019 issue of Breathe was published with an error in the name of one of the authors. The corrected author list is shown above. The article has been corrected and republished online.</p
Electrochemical DNA sensor technology for monitoring of drug-DNA interactions
No full textThe objective of this investigation is to understand the nature and dynamics of binding small molecules to bio-macromolecules using electrochemical methods. The investigation pertaining to the design of site- and conformation-specific reagents provides a rationale for new studies of drug delivery design. Some anticancer drugs and DNA interactions have been undertaken by using a variety of techniques. Determination of interaction between DNA and DNA-targeted molecules would be valuable in the design of molecule-specific electrochemical biosensors for applications in diagnostics, development of drugs for chemotherapy, and as a biotechnological tool for DNA-based point-of-care diagnosis. © World Scientific Publishing Company.106S181A. Erdem acknowledges financial support from TUBITAK (Project no. 106S181). A. Erdem, an associate member of TUBA expresses her gratitude to the TUBA for their support. A. Caliskan and H. Karadeniz acknowledge TUBITAK for scholarship for M.Sc. project and doctoral degree. -
An integrated approach of artificial neural networks and polynomial chaos expansion for prediction and analysis of yield and environmental impact of oil shale retorting process under uncertainty
No full textShale oil reserves exploration is getting huge investments due to the depletion of conventional reserves. Computational methods have been used to realize optimum design and operation of shale oil and gas reserves exploration and processing. The uncertainty associated with the composition of shale reserves and operating conditions during processing put a challenge to the realization of high yield and mitigation of environmental impact. In the current work, machine learning (ML) based models are proposed for the estimation of the yield and environmental impact of the oil shale retorting process under uncertainty. An artificial uncertainty of 1% was inserted in feed composition and process conditions of an Aspen model of the process to generate data for the development of the ML models. Artificial Neural Network (ANN), Least Square Boosting (LSB), and Bagging techniques were compared to find the best ML model. ANN models, with the highest correlation coefficient of 0.995 and 0.999 for the oil yield and CO2 content respectively, are used as surrogates in a Polynomial Chaos Expansion (PCE) framework for the uncertainty analysis of the process. For 1% uncertainty in feed composition and process conditions, a mean absolute deviation of 0.319 and 0.580 was obtained for the oil yield and carbon dioxide emissions respectively. To find the hierarchy in the process inputs in terms of their effect on the oil yield and carbon dioxide emissions, the ANN model is used as a surrogate in sensitivity analysis through Sobol and Fourier Amplitude Sensitivity Test (FAST) indices. The most sensitive input variables were feed temperature and air molar flow rate. The proposed modeling framework will provide a base for future real-time monitoring and analysis of the oil shale retorting processes
Correction to
No full textThe article “Intermittent levosimendan infusion in ambulatory patients with end‑stage heart failure: a systematic review and meta‑analysis of 984 patients”, written by Hagar Elsherbini, Osama Soliman, Casper Zijderhand, Mattie Lenzen, Sanne E. Hoeks, Rasha Kaddoura, Mohamed Izham5, Abdulaziz Alkhulaifi, Amr S. Omar, and Kadir Caliskan, was originally published electronically on the publisher’s internet portal on 11 April 2021 without open access. With the author(s)’ decision to opt for Open Choice the copyright of the article changed on 10 June 2021 to</p
Analysis of saponins and phenolic compounds as inhibitors of α-carbonic anhydrase isoenzymes
No full textA series of phenolic and saponin type natural products such as quercetin, rutin, catechin, epicatechin, silymarin, trojanoside H, astragaloside IV, astragaloside VIII and astrasieversianin X, were investigated for their inhibitory effects against the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). We here report inhibitory effects of these compounds against five α-CA isozymes (hCA I, hCA II, bCA III, hCA IV and hCA VI). Most of the phenolic and saponin type compounds inhibited the isoenzymes quite effectively at low micromolar KI-s ranging between 0.1 and 4 μM, whereas a few derivatives were ineffective (KI-s > 100 μM). The results were remarkable which might lead to design of novel CAIs with a diverse inhibition mechanism compared to sulfonamide/sulfamate inhibitors
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