1,720,958 research outputs found
Acridine orange and silica nanoparticles facilitated novel robust fluorescent hollow microcapsules toward DNA bio-sensor
No full textTuning optical properties by nanotechnology has become a topic of larger interest as these materials can be of extraordinary sensitivity, selectivity and robustness toward sensing applications. Here we report novel fluorescent hollow microcapsules via congregation of poly (l-lysine) interceded by silica nanoparticles and acridine orange. Scanning tunneling microscope images confirm spherical nature of microcapsules with size of 1-3μm. The hollow structures are verified by fluorescent images, which indicate acridine orange is intermingled in the shell wall of the microcapsules. The excitation fluorescence spectra reveal that acridine orange exists in monomeric and aggregated form within the microcapsules. But at pH 8.5, monomeric acridine orange diffuses out of microcapsules. Association of acridine orange with poly (l-lysine) and SiO2 nanoparticles in monomeric or aggregated form does not limit intercalation of acridine orange with DNA. Thus, the acridine orange based fluorescent hollow microcapsule could easily sense DNA in 100ngmL-1 concentration ranges. The excited state lifetime of fluorescent hollow microcapsules is shorter than acridine orange in neutral form, which further establishes a strong association of acridine orange with poly (l-lysine). However, the excited state lifetime is marginally quenched in the presence of DNA but independent of DNA concentration that rules out the possibility of intercalation in the excited state rather than a ground state complex formation. © 2013 .Ahmad H., 2013, J COLLOID SCI BIOTEC, V2, P153; Amali AJ, 2011, ANAL CHIM ACTA, V708, P75, DOI 10.1016-j.aca.2011.10.001; Amali AJ, 2012, CHEM COMMUN, V48, P856, DOI 10.1039-c1cc15209b; Bagaria HG, 2011, J MATER CHEM, V21, P9454, DOI 10.1039-c1jm10712g; Bi SY, 2006, SENSOR ACTUAT B-CHEM, V119, P199, DOI 10.1016-j.snb.2005.12.014; Boal AK, 2000, NATURE, V404, P746; BRUN AM, 1992, J AM CHEM SOC, V114, P3656, DOI 10.1021-ja00036a013; Carmona P.A.O., 2013, J COLLOID SCI BIOTEC, V2, P130; Connors KA., 1987, BINDING CONSTANTS ME; Du H, 1998, PHOTOCHEM PHOTOBIOL, V68, P141, DOI 10.1111-j.1751-1097.1998.tb02480.x; Kitazawa N, 2011, J MATER SCI, V46, P2036, DOI 10.1007-s10853-010-5035-x; Luchowski R, 2003, CHEM PHYS, V293, P155, DOI 10.1016-S0301-0104(03)00301-X; Lyles MB, 2002, BIOPHYS CHEM, V96, P53, DOI 10.1016-S0301-4622(02)00036-4; Manju S, 2011, COLLOID SURFACE B, V82, P588, DOI 10.1016-j.colsurfb.2010.10.021; Mann S, 1996, NATURE, V382, P313, DOI 10.1038-382313a0; Medintz IL, 2005, NAT MATER, V4, P435, DOI 10.1038-nmat1390; MURRAY CB, 1995, SCIENCE, V270, P1335, DOI 10.1126-science.270.5240.1335; Patra D, 2009, TALANTA, V77, P1549, DOI 10.1016-j.talanta.2008.09.007; Patra D, 2013, MICROCHIM ACTA, V180, P59, DOI 10.1007-s00604-012-0903-5; Patra D, 2009, J MATER CHEM, V19, P4017, DOI 10.1039-b822358k; Rahman MM, 2012, J MATER CHEM, V22, P1173, DOI 10.1039-c1jm13882k; Ribeiro L. F. V., 2013, J COLLOID SCI BIOTEC, V2, P78; Shaikh M, 2008, PHOTOCH PHOTOBIO SCI, V7, P408, DOI 10.1039-b715815g; Shenhar R, 2003, ACCOUNTS CHEM RES, V36, P549, DOI 10.1021-ar020083j; Veyret R, 2005, J MAGN MAGN MATER, V293, P171, DOI 10.1016-j.jmmm.2005.01.057; Vitzthum F, 1999, ANAL BIOCHEM, V276, P59, DOI 10.1006-abio.1999.4298; Whitesides GM, 2002, P NATL ACAD SCI USA, V99, P4769, DOI 10.1073-pnas.082065899; Wong MS, 2002, NANO LETT, V2, P583, DOI 10.1021-nl020244c0
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A new method for pH triggered curcumin release by applying poly(l-lysine) mediated nanoparticle-congregation
No full textWe introduce a novel method for encapsulation of curcumin by synthesizing microcapsule containing self-assembled nanoparticles using poly ( l-lysine), trisodium citrate and silica sol. Such microcapsules can only be prepared in neutral and alkaline environment and unencapsulated curcumin can be effectively removed by simple centrifugation with encapsulation efficiency 57.34percent. The particle sizes are in the range 0.7-3. μm with an effective diameter 1.05. μm. The structure of the microcapsules is dependent upon the solubility of curcumin in the solvent environment, the microcapsule are spherical when prepared in 10percent acetone and bowl-shaped-conical when prepared in water suspension, however, the size of these curcumin encapsulated microcapsules remain similar. Fluorescence microscope images confirm that curcumin is predominantly concentrated within the shell wall of the capsules. Photophysical behavior of Micro-curcumin with respect to curcumin alone is evaluated. Release of curcumin is found to be triggered by pH where acidic environment trigger maximum release compared to basic and neutral conditions. Micro-curcumin is as stable as curcumin. Drug release efficiency is found to be 61.44percent and the drug release profile of Micro-curcumin follow Higuchi model. It is also revealed that β-diketone group of curcumin responsible for scavenging activity is retained in the Micro-curcumin, thus suggesting applicability of such system as a poorly water soluble drug delivery vehicle. In contrast to other curcumin delivery systems, the presented method is easy, fast and does not need flow rate monitoring device. In addition poly ( l-lysine) as a non-toxic and highly stable material that prevents metabolic degradation is used in the present preparation method. © 2013 Elsevier B.V.Aggarwal BB, 2009, INT J BIOCHEM CELL B, V41, P40, DOI 10.1016-j.biocel.2008.06.010; Amali AJ, 2011, ANAL CHIM ACTA, V708, P75, DOI 10.1016-j.aca.2011.10.001; Amali AJ, 2011, ANGEW CHEM INT EDIT, V50, P1318, DOI 10.1002-anie.201005619; Amali AJ, 2012, CHEM COMMUN, V48, P856, DOI 10.1039-c1cc15209b; AMMON HPT, 1991, PLANTA MED, V57, P1, DOI 10.1055-s-2006-960004; Anand P, 2007, MOL PHARM, V4, P807, DOI 10.1021-mp700113r; Anand P, 2010, BIOCHEM PHARMACOL, V79, P330, DOI 10.1016-j.bcp.2009.09.003; Bagaria HG, 2011, J MATER CHEM, V21, P9454, DOI 10.1039-c1jm10712g; Benesi M. L., 1949, J AM CHEM SOC, V71, P2703; Bhawana R., 2011, J AGR FOOD CHEM, V59, P2056; Bich V.T., 2009, PHYS ENG NEW MAT SPR, V127, P271, DOI 10.1007-978-3-540-88201-5_31; Bisht Savita, 2007, Journal of Nanobiotechnology, V5, P3, DOI 10.1186-1477-3155-5-3; Bisht S, 2010, MOL CANCER THER, V9, P2255, DOI 10.1158-1535-7163.MCT-10-0172; Boal AK, 2000, NATURE, V404, P746; Chauhan S.C., 2007, P S DAK ACAD SCI, V86, P283; Cheng AL, 2001, ANTICANCER RES, V21, P2895; Clifford NW, 2008, J MATER CHEM, V18, P162, DOI 10.1039-b715100d; Das RK, 2010, NANOMED-NANOTECHNOL, V6, P153, DOI 10.1016-j.nano.2009.05.009; De R, 2009, ANTIMICROB AGENTS CH, V53, P1592, DOI 10.1128-AAC.01242-08; Deeb Dorrah D, 2005, J Exp Ther Oncol, V5, P81; Deng XM, 2002, EUR POLYM J, V38, P1435, DOI 10.1016-S0014-3057(02)00017-4; DEODHAR SD, 1980, INDIAN J MED RES, V71, P632; Eigner D, 1999, J ETHNOPHARMACOL, V67, P1, DOI 10.1016-S0378-8741(98)00234-7; FALK M, 1989, MAT SCI ENG A-STRUCT, V114, P209, DOI 10.1016-0921-5093(89)90861-7; Gupta V, 2009, INT J NANOMED, V4, P115; Hassenkam T, 2002, ADV MATER, V14, P1126, DOI 10.1002-1521-4095(20020816)14:161126::AID-ADMA11263.0.CO;2-A; HIGUCHI T, 1963, J PHARM SCI, V52, P1145, DOI 10.1002-jps.2600521210; JACKSON M, 1989, BIOCHIM BIOPHYS ACTA, V998, P75, DOI 10.1016-0167-4838(89)90121-0; Jordan WC, 1996, J NATL MED ASSOC, V88, P333; Jovanovic SV, 1999, J AM CHEM SOC, V121, P9677, DOI 10.1021-ja991446m; Karmakar S, 2006, NEUROSCI LETT, V407, P53, DOI 10.1016-j.neulet.2006.08.013; KISO Y, 1983, PLANTA MED, V49, P185, DOI 10.1055-s-2007-969845; Kolev TM, 2005, INT J QUANTUM CHEM, V102, P1069, DOI 10.1002-qua.20469; KUTTAN R, 1987, TUMORI, V73, P29; Landis-Piwowar KR, 2006, DRUG RESIST UPDATE, V9, P263, DOI 10.1016-j.drup.2006.11.001; Lao Christopher D, 2006, BMC Complement Altern Med, V6, P10, DOI 10.1186-1472-6882-6-10; Lee YK, 2009, J AGR FOOD CHEM, V57, P305, DOI 10.1021-jf802737z; Liang GA, 2009, BIOORGAN MED CHEM, V17, P2623, DOI 10.1016-j.bmc.2008.10.044; Lopez-Lazaro M, 2008, MOL NUTR FOOD RES, V52, pS103, DOI 10.1002-mnfr.200700238; Maiti K, 2007, INT J PHARMACEUT, V330, P155, DOI 10.1016-j.ijpharm.2006.09.025; Mann S, 1996, NATURE, V382, P313, DOI 10.1038-382313a0; MURRAY CB, 1995, SCIENCE, V270, P1335, DOI 10.1126-science.270.5240.1335; Nardo L, 2009, J PHOTOCH PHOTOBIO B, V97, P77, DOI 10.1016-j.jphotobiol.2009.08.004; Ozcelik B, 2003, J FOOD SCI, V68, P487, DOI 10.1111-j.1365-2621.2003.tb05699.x; Patra D, 2011, SPECTROCHIM ACTA A, V79, P1034, DOI 10.1016-j.saa.2011.04.016; Patra D, 2012, COLLOID SURFACE B, V94, P354, DOI 10.1016-j.colsurfb.2012.02.017; Patra D, 2011, SPECTROCHIM ACTA A, V79, P1823, DOI 10.1016-j.saa.2011.05.064; Patra D, 2012, INT J BIOL MACROMOL, V50, P885, DOI 10.1016-j.ijbiomac.2012.02.010; Patra D, 2009, J MATER CHEM, V19, P4017, DOI 10.1039-b822358k; Patwardhan SV, 2003, CHEM COMMUN, P1122, DOI 10.1039-b302056h; Pizzo P, 2010, J CELL MOL MED, V14, P970, DOI 10.1111-j.1582-4934.2009.00681.x; QURESHI S, 1992, PLANTA MED, V58, P124, DOI 10.1055-s-2006-961412; Rana RK, 2005, ADV MATER, V17, P1145, DOI 10.1002-adma.200401612; RYSER HJP, 1980, CANCER, V45, P1207, DOI 10.1002-1097-0142(19800315)45:5+1207::AID-CNCR28204513273.0.CO;2-M; RYSER HJP, 1978, P NATL ACAD SCI USA, V75, P3867, DOI 10.1073-pnas.75.8.3867; BHAVANISHANKAR TN, 1980, INDIAN J EXP BIOL, V18, P73; Shen L, 2007, SPECTROCHIM ACTA A, V67, P619, DOI 10.1016-j.saa.2006.08.018; Shenhar R, 2003, ACCOUNTS CHEM RES, V36, P549, DOI 10.1021-ar020083j; Shishodia S, 2005, BIOCHEM PHARMACOL, V70, P700, DOI 10.1016-j.bcp.2005.04.043; Shishodia S, 2007, CURR PROB CANCER, V31, P243, DOI 10.1016-j.currproblcancer.2007.04.001; SRIMAL RC, 1973, J PHARM PHARMACOL, V25, P447; SRIVASTAVA R, 1985, THROMB RES, V40, P413, DOI 10.1016-0049-3848(85)90276-2; Sugiyama Y, 1996, BIOCHEM PHARMACOL, V52, P519, DOI 10.1016-0006-2952(96)00302-4; WAHLSTROM B, 1978, ACTA PHARMACOL TOX, V43, P86; Wang D, 2008, CLIN CANCER RES, V14, P6228, DOI 10.1158-1078-0432.CCR-07-5177; Wang Y, 2009, INT J FOOD MICROBIOL, V136, P71, DOI 10.1016-j.ijfoodmicro.2009.09.001; Whitesides GM, 2002, P NATL ACAD SCI USA, V99, P4769, DOI 10.1073-pnas.082065899; Wong MS, 2002, NANO LETT, V2, P583, DOI 10.1021-nl020244c; Yallapu MM, 2010, J COLLOID INTERF SCI, V351, P19, DOI 10.1016-j.jcis.2010.05.022; Yallapu MM, 2010, MACROMOL BIOSCI, V10, P1141, DOI 10.1002-mabi.201000084; Yang FS, 2005, J BIOL CHEM, V280, P5892, DOI 10.1074-jbc.M404751200; Yu J, 2010, J AM CHEM SOC, V132, P1929, DOI 10.1021-ja908139y24
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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