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排序方式: 共有433条查询结果,搜索用时 31 毫秒
21.
Dr. Ricardo Ferraz Prof. João Costa‐Rodrigues Prof. Maria H. Fernandes Dr. Miguel M. Santos Dr. Isabel M. Marrucho Prof. Luís Paulo N. Rebelo Prof. Cristina Prudêncio Prof. João Paulo Noronha Dr. Željko Petrovski Dr. Luís C. Branco 《ChemMedChem》2015,10(9):1480-1483
Significant antiproliferative effects against various tumor cell lines were observed with novel ampicillin salts as ionic liquids. The combination of anionic ampicillin with appropriate ammonium, imidazolium, phosphonium, and pyridinium cations yielded active pharmaceutical ingredient ionic liquids (API‐ILs) that show potent antiproliferative activities against five different human cancer cell lines: T47D (breast), PC3 (prostate), HepG2 (liver), MG63 (osteosarcoma), and RKO (colon). Some API‐ILs showed IC50 values between 5 and 42 nM , activities that stand in dramatic contrast to the negligible cytotoxic activity level shown by the ampicillin sodium salt. Moreover, very low cytotoxicity against two primary cell lines—skin (SF) and gingival fibroblasts (GF)—indicates that the majority of these API‐ILs are nontoxic to normal human cell lines. The most promising combination of antitumor activity and low toxicity toward healthy cells was observed for the 1‐hydroxyethyl‐3‐methylimidazolium–ampicillin pair ([C2OHMIM][Amp]), making this the most suitable lead API‐IL for future studies. 相似文献
22.
Nataša Z. Tomić Aleksandar D. Marinković Željko Radovanović Kata Trifković Milena Marinović-Cincović Radmila Jančić Heinemann 《Journal of Polymer Research》2018,25(4):96
Atom transfer free radical polymerization (ATRP) was employed in a synthesis of graft polymer EVA-g-PMMA with controlled length of side PMMA chains. Three steps of synthesis: partial hydrolysis of EVA, esterification with chloroacetyl chloride and ATRP grafting were performed to produce EVAOH, macroinitiator EVACl and grafted polymers G8020 (EVA/PMMA?=?80/20 wt%) and G6040 (EVA/PMMA?=?60/40 wt%). FTIR, Raman and NMR spectroscopy were used in the determination of the chemical structure and modification of EVA. Transmitted light and dark field microscopy showed higher affinity for coil formation of EVA-g-PMMA with longer PMMA side chains, i.e. G6040 compatibilizer. Morphological, thermal and adhesive properties of optical fiber adhesives of graft polymers and polymer blends poly(ethylene-co-vinyl acetate)-blend-poly(methyl methacrylate) (EVA/PMMA) compatibilized with 1 wt% of EVA-g-PMMA, were studied. Image analysis of SEM micrographs showed effective compatibilization with short grafted chains (G8020) that was indicated by lower porosity characteristics. TG/DTG analysis enabled determination of degree of hydrolysis and amount of chloro-functionalized groups. DSC analysis showed higher thermal stability of G8020 polymer. Single lap joint of adhesives/optical fibers were subjected to adhesive testing and obtained results for maximal force applied and adhesive failure suggested the visible influence of the length of graft chains on adhesion. 相似文献
23.
Slobodan?P.??erbanovi? Ivona?R.?Grguri? Mirjana?Lj.?Kijev?anin Aleksandar?Z.?Tasi? Bojan?D.?Djordjevi?Email author 《Korean Journal of Chemical Engineering》2004,21(4):858-866
A comparison of the performances of two different approaches of cubic equations of state models, based on a classical van
der Waals and mixing rules incorporating theG
E
equation, was carried out for correlation of Vapor-Liquid Equilibria (VLE), HE and C
P
E
data alone, and simultaneous correlation of VLE+HE, VLE+C
P
E
, HE +C
P
E
and VLE+HE +C
P
E
data for the diethers (1,4-dioxane or 1,3-dioxolane) with n-alkane systems. For all calculations the Peng-Robinson-Stryjek-Vera
cubic equation of state (PRSV CEOS) was used. A family of mixing rules for the PRSV CEOS based on the Modified van der Waals
one-fluid mixing rule (MvdW1) and two well-known CEOS/GE mixing rules (MHV1 and MHV2), was considered. The NRTL equation, as the GE model with linear or reciprocal temperature dependent parameters, was incorporated in the CEOS/GE models. The results obtained by the CEOS/GE models exhibit significant improvement in comparison to the MvdW1 models. 相似文献
24.
Aleksandar Dedic 《Drying Technology》2013,31(10):2557-2564
ABSTRACT This paper presents the specific methods to obtain sorption isotherms. Sorption isotherms were first obtained experimentally for 20°C and 100°C and then, by using the presented method, isotherms were also obtained for 50°C and 80°C. The same treatment can be applied in finding any isotherm sorption in the temperature range between 20°Cand 100°C. The experiments were carried out on beech (Fagus moesiaca) and sample dimensions were 3×3×3cm. Based on the results of the experiment, by regression analysis, the most suitable analytic formula was proposed. It relsites temperature and air humidity with the equilibrium moisture content in wood. Experimental results were compared with psychrometric tables and Bramhall's formula for desorption curves with good agreement. This proves that the method presented in this paper is precise and efficient to decrease the lime needed to obtain sorption isotherms experimentally. 相似文献
25.
Ivan Gutman Sven J. Cyvin Vesna Petrović Aleksandar Teodorović 《Polycyclic Aromatic Compounds》2013,33(3):183-189
Abstract A fully-naphthalenoid hydrocarbon (FUN) is a benzenoid hydrocarbon whose all π-electrons can be (formally) grouped into disjoint naphthalene-units. The cyclic conjugation in FUNs is studied by means of the energy-effects of their various cycles. It is found that the dominant conjugation modes in FUNs are those involving the 6- and 10-membered cycles of the “full” naphthalene fragments. The cycles belonging to the “empty” domains of a FUN have significantly smaller energy-effects. 相似文献
26.
Aleksandar Kova?evi?Author Vitae 《Computer Speech and Language》2012,26(2):105-126
The task of reviewing scientific publications and keeping up with the literature in a particular domain is extremely time-consuming. Extraction and exploration of methodological information, in particular, requires systematic understanding of the literature, but in many cases is performed within a limited context of publications that can be manually reviewed by an individual or group. Automated methodology identification could provide an opportunity for systematic retrieval of relevant documents and for exploring developments within a given discipline. In this paper we present a system for the identification of methodology mentions in scientific publications in the area of natural language processing, and in particular in automatic terminology recognition. The system comprises two major layers: the first layer is an automatic identification of methodological sentences; the second layer highlights methodological phrases (segments). Each mention is categorised in four semantic categories: Task, Method, Resource/Feature and Implementation. Extraction and classification of the segments is formalised as a sequence tagging problem and four separate phrase-based Conditional Random Fields are used to accomplish the task. The system has been evaluated on a manually annotated corpus comprising 45 full text articles. The results for the segment level annotation show an F-measure of 53% for identification of Task and Method mentions (with 70% precision), whereas the F-measures for Resource/Feature and Implementation identification were 61% (with 67% precision) and 75% (with 86% precision) respectively. At the document-level, an F-measure of 72% (with 81% precision) for Task mentions, 60% (with 81% precision) for Method mentions, 74% (with 78% precision) for the Resource/Feature and 79% (with 81% precision) for the Implementation categories have been achieved. We provide a detailed analysis of errors and explore the impact that the particular groups of features have on the extraction of methodological segments. 相似文献
27.
Antoine Doucet Gabriella Kazai Bodin Dresevic Aleksandar Uzelac Bogdan Radakovic Nikola Todic 《International Journal on Document Analysis and Recognition》2011,14(1):45-52
This paper describes the setup of the Book Structure Extraction competition run at ICDAR 2009. The goal of the competition was to evaluate and compare automatic techniques for deriving structure information from digitized books, which could then be used to aid navigation inside the books. More specifically, the task that participants faced was to construct hyperlinked tables of contents for a collection of 1,000 digitized books. This paper describes the setup of the competition and its challenges. It introduces and discusses the book collection used in the task, the collaborative construction of the ground truth, the evaluation measures, and the evaluation results. The paper also introduces a data set to be used freely for research evaluation purposes. 相似文献
28.
Aleksandar Zeljić Christoph M. Wintersteiger Philipp Rümmer 《Journal of Automated Reasoning》2017,58(1):127-147
We consider the problem of automatically and efficiently computing models of constraints, in the presence of complex background theories such as floating-point arithmetic. Constructing models, or proving that a constraint is unsatisfiable, has various applications, for instance for automatic generation of test inputs. It is well-known that a naïve encoding of constraints into simpler theories (for instance, bit-vectors or propositional logic) often leads to a drastic increase in size, or that it is unsatisfactory in terms of the resulting space and runtime demands. We define a framework for systematic application of approximations in order to improve performance. Our method is more general than previous techniques in the sense that approximations that are neither under- nor over-approximations can be used, and it shows promising performance on practically relevant benchmark problems. 相似文献
29.
Perica Paunović Orce Popovski Emilija Fidančevska Bogdan Ranguelov Dafinka Stoevska Gogovska Aleksandar T. Dimitrov Svetomir Hadži Jordanov 《International Journal of Hydrogen Energy》2010
The subject of this work is the use of non-stoichiometric titanium oxides – Magneli phases as support material of Co-based electrocatalysts aimed for hydrogen/oxygen evolution reaction. Commercial micro-scaled Ebonex (Altraverda, UK) was mechanically treated for 4, 8, 12, 16 and 20 h and further Co metallic phase was grafted by sol-gel method. Morphology of Co/Ebonex electrocatalysts was observed by means of TEM and SEM microscopy, while electrochemical behavior by means of cyclic voltammetry and steady-state galvanostatic method. 相似文献
30.
An examination of the mechanisms for stable foam formation in activated sludge systems 总被引:1,自引:0,他引:1
Screening pure cultures of 65 mycolic acid producing bacteria (Mycolata) isolated mainly from activated sludge with a laboratory based foaming test revealed that not all foamed under the conditions used. However, for most, the data were generally consistent with the flotation theory as an explanation for foaming. Thus a stable foam required three components, air bubbles, surfactants and hydrophobic cells. With non-hydrophobic cells, an unstable foam was generated, and in the absence of surfactants, cells formed a greasy surface scum. Addition of surfactant converted a scumming population into one forming a stable foam. The ability to generate a foam depended on a threshold cell number, which varied between individual isolates and reduced markedly in the presence of surfactant. Consequently, the concept of a universal threshold applicable to all foaming Mycolata is not supported by these data. The role of surfactants in foaming is poorly understood, but evidence is presented for the first time that surfactin synthesised by Bacillus subtilis may be important. 相似文献