426 research outputs found

    PHYSICAL APPEARANCE OF Cd-SUBSTITUTED COBALT FERRITE NANOPARTICLES

    Get PDF
    Objective: Ferrites are an important class of magnetic materials and the most important property of ferrite is its high electrical resistivity, low eddy current, and dielectric losses. The nanostructured ultrafine samples of the ferrite series are prepared by using the Sol-Gel auto combustion method. The prepared samples were characterized by X-ray diffraction (XRD) and Scanning Electron Micrograph (SEM) techniques. X-ray analysis confirms the formation of a single-phase cubic spinel structure. Materials and Methods: A series of polycrystalline nano ferrite having the chemical formula Co1-xCdxFe2O4 (where, x= 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) were prepared by using Sol-Gel auto combustion method. The starting materials cobalt nitrate (Co(NO3)2·6H2O), ferric nitrate (Fe(NO3)2·9H2O), Cadmium nitrate (Cd(NO3)2·9H2O), citric acid (C6H8O7·H2O) and ammonia (NH3) solution were taken in 99.9% AR grade. Results: In the Co1-xCdxFe2O4 ferrite system, the lattice constant, hopping length (LA and LB) and A-site (A-O) and B-site (B-O) bond length of the samples has been increased due to the increase in cadmium content. The crystalline size of the samples lies in the range between 18nm to 33nm calculated by using Sherrer’s formula Conclusion: Nanaosized Co1-xCdxFe2O4 system was synthesized by using the sol-gel technique

    Certain subclasses of multivalent functions defined by new multiplier transformations

    Full text link
    In the present paper the new multiplier transformations \mathrm{{\mathcal{J}% }}_{p}^{\delta }(\lambda ,\mu ,l) (\delta ,l\geq 0,\;\lambda \geq \mu \geq 0;\;p\in \mathrm{% }%\mathbb{N} )} of multivalent functions is defined. Making use of the operator Jpδ(λ,μ,l),\mathrm{% {\mathcal{J}}}_{p}^{\delta }(\lambda ,\mu ,l), two new subclasses Pλ,μ,lδ(A,B;σ,p)\mathcal{% P}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) and P~λ,μ,lδ(A,B;σ,p)\widetilde{\mathcal{P}}% _{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p)\textbf{\ }of multivalent analytic functions are introduced and investigated in the open unit disk. Some interesting relations and characteristics such as inclusion relationships, neighborhoods, partial sums, some applications of fractional calculus and quasi-convolution properties of functions belonging to each of these subclasses Pλ,μ,lδ(A,B;σ,p)\mathcal{P}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) and P~λ,μ,lδ(A,B;σ,p)\widetilde{\mathcal{P}}_{\lambda ,\mu ,l}^{\delta }(A,B;\sigma ,p) are investigated. Relevant connections of the definitions and results presented in this paper with those obtained in several earlier works on the subject are also pointed out

    Tight-binding parameters for charge transfer along DNA

    Full text link
    We systematically examine all the tight-binding parameters pertinent to charge transfer along DNA. The π\pi molecular structure of the four DNA bases (adenine, thymine, cytosine, and guanine) is investigated by using the linear combination of atomic orbitals method with a recently introduced parametrization. The HOMO and LUMO wavefunctions and energies of DNA bases are discussed and then used for calculating the corresponding wavefunctions of the two B-DNA base-pairs (adenine-thymine and guanine-cytosine). The obtained HOMO and LUMO energies of the bases are in good agreement with available experimental values. Our results are then used for estimating the complete set of charge transfer parameters between neighboring bases and also between successive base-pairs, considering all possible combinations between them, for both electrons and holes. The calculated microscopic quantities can be used in mesoscopic theoretical models of electron or hole transfer along the DNA double helix, as they provide the necessary parameters for a tight-binding phenomenological description based on the π\pi molecular overlap. We find that usually the hopping parameters for holes are higher in magnitude compared to the ones for electrons, which probably indicates that hole transport along DNA is more favorable than electron transport. Our findings are also compared with existing calculations from first principles.Comment: 15 pages, 3 figures, 7 table

    Plant and algal chlorophyll synthases function in Synechocystis and interact with the YidC/Alb3 membrane insertase

    Get PDF
    In the model cyanobacteriumSynechocystissp. PCC 6803, the terminalenzyme of chlorophyll biosynthesis, chlorophyll synthase (ChlG), forms acomplex with high light-inducible proteins, the photosystem II assembly fac-tor Ycf39 and the YidC/Alb3/OxaI membrane insertase, co-ordinatingchlorophyll delivery with cotranslational insertion of nascent photosystempolypeptides into the membrane. To gain insight into the ubiquity of thisassembly complex in higher photosynthetic organisms, we produced functionalforeign chlorophyll synthases in a cyanobacterial host. Synthesis of algal andplant chlorophyll synthases allowed deletion of the otherwise essential nativecyanobacterial gene. Analysis of purified protein complexes shows that theinteraction with YidC is maintained for both eukaryotic enzymes, indicatingthat a ChlG-YidC/Alb3 complex may be evolutionarily conserved in algaeand plants

    Evidence Map of Pancreatic Surgery–A living systematic review with meta-analyses by the International Study Group of Pancreatic Surgery (ISGPS)

    Get PDF
    Background: Pancreatic surgery is associated with considerable morbidity and, consequently, offers a large and complex field for research. To prioritize relevant future scientific projects, it is of utmost importance to identify existing evidence and uncover research gaps. Thus, the aim of this project was to create a systematic and living Evidence Map of Pancreatic Surgery. Methods: PubMed, the Cochrane Central Register of Controlled Trials, and Web of Science were systematically searched for all randomized controlled trials and systematic reviews on pancreatic surgery. Outcomes from every existing randomized controlled trial were extracted, and trial quality was assessed. Systematic reviews were used to identify an absence of randomized controlled trials. Randomized controlled trials and systematic reviews on identical subjects were grouped according to research topics. A web-based evidence map modeled after a mind map was created to visualize existing evidence. Meta-analyses of specific outcomes of pancreatic surgery were performed for all research topics with more than 3 randomized controlled trials. For partial pancreatoduodenectomy and distal pancreatectomy, pooled benchmarks for outcomes were calculated with a 99% confidence interval. The evidence map undergoes regular updates. Results: Out of 30, 860 articles reviewed, 328 randomized controlled trials on 35, 600 patients and 332 systematic reviews were included and grouped into 76 research topics. Most randomized controlled trials were from Europe (46%) and most systematic reviews were from Asia (51%). A living meta-analysis of 21 out of 76 research topics (28%) was performed and included in the web-based evidence map. Evidence gaps were identified in 11 out of 76 research topics (14%). The benchmark for mortality was 2% (99% confidence interval: 1%–2%) for partial pancreatoduodenectomy and <1% (99% confidence interval: 0%–1%) for distal pancreatectomy. The benchmark for overall complications was 53% (99%confidence interval: 46%–61%) for partial pancreatoduodenectomy and 59% (99% confidence interval: 44%–80%) for distal pancreatectomy. Conclusion: The International Study Group of Pancreatic Surgery Evidence Map of Pancreatic Surgery, which is freely accessible via www.evidencemap.surgery and as a mobile phone app, provides a regularly updated overview of the available literature displayed in an intuitive fashion. Clinical decision making and evidence-based patient information are supported by the primary data provided, as well as by living meta-analyses. Researchers can use the systematic literature search and processed data for their own projects, and funding bodies can base their research priorities on evidence gaps that the map uncovers. © 2021 The Author
    corecore