Scientific collaboration of researchers and organizations: a two-level blockmodeling approach

Scientometrics - The development and successful implementation of R&D policies depends on understanding patterns of scientific collaboration (SC). Existing studies on SC typically focus on...     

Quality of information and communication technology introduction

Software Quality Journal -     

Surface decoration of magnetic nanoparticles with folate-conjugated poly(N-isopropylacrylamide-co-itaconic acid): A facial synthesis of dual-responsive nanocarrier for targeted delivery of doxorubicin

The aim of study was to develop a novel drug nanocarrier via facile coating of a folate-conjugated dual-responsive copolymer with carboxylic functional groups on the surface of magnetic nanoparticles for the efficient loading and cell-specific targeting of a positively charged anticancer agent. The nanocarrier exhibited many favorable capabilities such as narrow distributed nano-ranged size (～30 nm), high drug loading capacity (～65%), and stimuli-responsive drug release. The results of various cell cytotoxicity studies such as MTT assay, DAPI staining, and flow cytometry concluded that the developed smart nanocarrier paves a way for efficient cancer therapy by the multiple targeting strategies.     

Identification of Mg<Subscript>2</Subscript>Cu particles in Cu-alloyed austempered ductile iron

In the present work, the Mg₂Cu precipitates in copper-alloyed austempered ductile iron (ADI) were identified by analyzing techniques such as TEM and SEM with EDS. It was revealed that, in castings made of ADI-containing copper, highly dispersed particles of Mg₂Cu are formed, whose size does not exceed <1 μm. The research work was carried out on ductile iron that was austenitized at 900 °C, followed by austempering at 380 °C. The microstructure was investigated using various techniques, including optical microscopy, XRD, SEM, and TEM. In addition to this, the exhibited impact properties of castings with Cu, Ni, and Cu+Ni were also determined. This study casts a new light on the formation of the structure of Cu-alloyed ADI. The highly-dispersive and brittle Mg₂Cu particles that are located in the vicinity of the graphite nodules have a negative effect on the impact properties of ADI. It has also been shown that impact strength decreases from levels of 160-180 J (for copper-free ADI) to 90-120 J (for copper-and copper-nickel-alloyed ADI).     

Evaluating and quantifying the liming potential of phosphate rocks

The liming potential of phosphate rock was evaluated with theoreticalcalculations and quantified by laboratory titration and soil incubation. Threeanions present in the carbonate apatite structure of phosphate rock that canconsume protons and cause an increase in pH when dissolved from apatite arePO₄ ^3–, CO₃ ^2–, andF^–. The pKa for HF is so low that F^– has verylittle effect on increasing pH. The pKa for 2 protons onH₂PO₄ ^– and H₂CO₃are sufficiently high enough to cause an increase in pH withPO₄ ^3– and CO₃ ^2–releasedinto solution if the pH range is between 4 and 6. Because of the greater molarquantity of PO₄ ^3– compared toCO₃ ^2–, PO₄ ^3– exerts agreater affect on the liming potential of P rock. For a variety of phosphaterocks with a axes ranging from 9.322 to 9.374 Å in the carbonate apatitestructure, the theoretical % calcium carbonate equivalence (CCE) rangesfrom 59.5 to 62%. With the presence of gangue carbonate minerals from2.5to 10% on a weight basis in the phosphate rocks, the theoretical%CCE ranges from 59.5 to 63.1%. Use of AOAC method 955.01 forquantifying the %CCE of North Carolina phosphate rock (NCPR) and Idahophosphate rock (IDPR) resulted in %CCE ranging from 39.9 to 53.7%which were less than the theoretical values. The lower values measured in theAOAC method was presumed to be due to formation of CaHPO₄ orCaHPO₄·2H₂O precipitates which would result inlessthan 2 protons neutralized per mole of PO₄ ^3–released from carbonate apatite. The highly concentrated solution formed in themethod was considered not indicative of a soil solution and thus determined%CCE values would be suspect. A soil incubation study was conducted todetermine a more appropriate %CCE value in a soil environment usingCopper Basin, Tennessee soil with a soil pH of 4.2. Agricultural limestone,NCPR, IDPR, and a granulated IDPR were added to 100 g of soil atrates of 0.1, 0.3, 1, 3, and 10 g/kg soil, incubated for 105 daysat field moisture capacity, and analyzed for changes in soil pH and P. The%CCE of each phosphate rock addition was determined using limestone as astandard curve. The relationship between %CCE and % dissolved Pfollowed a quadratic model where%CCE=8.47+0.0078(%dissolved P)² (r²=0.84).At 0% dissolved P, the model predicted 8.47% CCE which wasprobably due to gangue carbonate minerals. The experimental model showedqualitative agreement with theory showing increased liming ability withincreased dissolved P from the P rock. However, the model showed lower%CCE than theoretical calculations when %P dissolved ranged from20 to 60%.     

Automatic Generation of Language-based Tools

Many tools can be automatically derived from formal language definitions, such as compilers/interpreters, editors, analyzers, visualizers/animators, etc. Some examples of language-based tools generated automatically by the LISA system are described in the paper. In addition the specification of an algorithm animator and program visualizer, Alma, generated from an extended LISA input-grammar is discussed; LISA principles and code are reused in Alma implementation.     

Das magnetische Feld des gleichstromdurchflossenen Leiters von elliptischem Querschnitt

Übersicht Es wird das magnetfeld eines elliptischen Stromleiters bestimmt. Die Permeabiliät des Leiters ₁ und des umgebenden Raumes ₂ sind beliebig. Zur Berechnung wird die Methode der Trennung der Veränderlichen angewendet.

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Contents The magnetic Field of the wire of eliptical cross section has been determined. The calculations have been carried out for any permeability values of the wire and its environment. The Fourier method of separation of variables has been applied.

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Bezeichnungen a, b Halbachsen der Ellipse - c Ellipsenexzentrizität - ₁ Permeabilität des Leiters - ₂ Permeabilität des Raumes - , ,z elliptische Koordinaten - a ,a ,a _z Einheitsvektoren - A Vektorpotential - B _x ,B _y Induktionskomponenten im kartesischen Koordinatensystem - B ,B Induktionskomponenten im elliptischen Koordinatensystem - C, D Konstanten - J Stromdichte - I Leiterstrom - Index I Innengebiet des Leiters - Index II Außengebiet des Leiters     

Growth properties and growth factor responsiveness in skin fibroblasts from centenarians

Human fibroblast cultures, which have a finite replicative lifespan in vitro, are the most widely used model for the study of senescence at the cellular level. An inverse relationship between replicative capability and donor age has been reported in human fibroblast strains. We studied the growth capacity of fibroblast primary cultures derived from people whose lifespan was as closer as possible to the expected maximum human lifespan, i.e. people over one hundred. Our data suggest that outgrowth of fibroblasts from biopsies, growth kinetics at different population doubling levels, capability to respond to a classical mitogenic stimulus (such as 20% serum) and a variety of growth factors, were remarkably similar in fibroblasts from centenarians and young controls. On the whole, our data challenge the tenet of a simple and strict relationship between in vivo aging and in vitro proliferative capability of human fibroblasts, at least at the individual level.