1,721,029 research outputs found
Aptamer-antibody hybrid ELONA that uses hybridization chain reaction to detect a urinary biomarker EN2 for bladder and prostate cancer
No full textWe report an EN2-specific (K(d) = 8.26 nM) aptamer, and a sensitive and specific enzyme-linked oligonucleotide assay (ELONA) for rapid and sensitive colorimetric detection of bladder and prostate cancer biomarker EN2 in urine. The assay relies on an aptamer-mediated hybridization chain reaction (HCR) to generate DNA nanostructures that bind to EN2 and simultaneously amplify signals. The assay can be performed within 2.5 h, and has a limit of detection of 0.34 nM in buffer and 2.69 nM in artificial urine. Moreover, this assay showed high specificity as it did not detect other urinary proteins, including biomarkers of other cancers. The proposed ELONA is inexpensive, highly reproducible, and has great chemical stability, so it may enable development of a simple, sensitive and accurate diagnostic tool to detect bladder and prostate cancers early
Development of an optical sandwich ELONA using a pair of DNA aptamers for yellow fever virus NS1
No full text© 2022Here, we proposed an enzyme-linked oligonucleotide assay (ELONA) for yellow fever (YF) diagnosis that uses a pair of aptamers, YFns1-4 and YFns1-31. The aptamers were selected to specifically bind to nonstructural protein 1 (NS1), which is secreted at a high concentration after YF infection. We applied the aptamers which did not interfere with each other on binding to the NS1 in a sandwich ELONA. In the assay, the best detection sensitivity was obtained when the combination of YFns1-31 as a capture aptamer and YFns1-4 as a detect aptamer was used. The sensitivity could be attributed to the results of the direct ELONA with each YFns1-4 and YFns1-31; a great absorbance intensity and a broad detectable range of NS1, respectively. The sandwich ELONA achieved a low detection limit of 0.85 nM in buffer and was highly specific to the YFV-NS1 as its detection signals were significantly distinct from those of other flavivirus-derived NS1. In addition, the assay showed a desirable sensitivity in serum-spiked condition. Our developed sandwich ELONA can be a new practical and applicable serological diagnostics in YF endemic regions where other flaviviruses coexist and facilities for complex diagnostic tests are lacking.11Nsciescopu
Deciphering oxygen vacancies and d-band structures as key descriptors for understanding electrocatalytic trend of glycerol oxidation reaction kinetics in alkaline media
No full textDespite the advantages of employing electrocatalytic glycerol oxidation reaction (EGOR) as the anode reaction for hydrogen production, the limited understanding of how electrocatalytic activity trends relate to the intrinsic properties of electrocatalysts leads to frequent trial and error in designing high-performance electrocatalyst materials. Herein, we report systematic studies to decipher the correlation between the kinetics of EGOR under alkaline conditions and the concentration of oxygen vacancy (Vo) and d-band filling (fd) of electrocatalysts using a perovskite-based model system. The modulation of transition metal species in the B-site of LaMO3 (M = transition metal species such as Mn, Fe, Co, and Ni) electrocatalysts allows the systematic control of the density of Vo and fd of electrocatalysts. Our results, based on the experimental and computational calculation analyses, show that LaNiO3 (LNO) with the highest contents of Vo and fd exhibits the most enhanced intrinsic kinetics of EGOR. This is because accelerated charge transfer between LNO and glycolate species by high contents of Vo and fd weakens the strength of C-C bond in glycolate. In particular, the contents of Vo and fd have a proportional relationship with the specific electrocatalytic activity of LaMO3, indicating that Vo and fd can be used as descriptors to predict the specific activity of electrocatalysts. This work highlights the importance of controlling Vo and fd of electrocatalysts to achieve high performance EGOR.
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
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
Facilitating C-C bond cleavage toward selective electrocatalytic oxidation of glycerol to formic acid: d-p orbital hybridization and adsorption thermodynamics
No full textFormic acid (FA) is a high-value product in hydrogen energy systems; hence, its selective production via electrochemical glycerol oxidation reaction (GOR) in an alkaline medium has emerged as an energy-efficient approach. However, the process is hindered by sluggish C-C bond cleavage, limited charge transfer, and competitive adsorption between glycerol and OH* species. In this study, we design La-based perovskite electrocatalysts with dual B-site metal incorporation to address the key challenges of alkaline GOR. Among various transition metal combinations (Ni, Fe, and Co), LaNi0.5Co0.5O3 (LNCO) demonstrates the highest GOR performance due to a synergistic effect between Ni and Co, which has been shown to modulate the electronic structure and optimize adsorption thermodynamics. In particular, LNCO exhibits enhanced charge transfer behavior, driven by metal 3d-oxygen 2p orbital hybridization and by a delocalized electronic structure with negligible band gap. Furthermore, glycerol adsorption is thermodynamically more favorable than OH* species, providing balanced adsorption energy conducive to efficient GOR. Consequently, LNCO promotes C-C bond cleavage kinetics and enhances selective FA production. These findings highlight that LNCO is a promising electrocatalytic platform for value-added chemical synthesis via a sustainable electrochemical route.
성향점수매칭을 이용한 미세치근단수술의 예후 인자 분석
No full textDept. of Dentistry/박사1. Objectives
The purpose of this retrospective clinical study is to evaluate effect of various potential prognostic factors related to endodontic microsurgery on the clinical outcome with PSM analysis. Five factors are included in this study. Lesion type(isolated endodontic lesion vs. endodontic-periodontal combined lesion), surgery type(initial surgery vs. re-surgery), the existence of through-and-through lesion, Endocem as root-end filling material, and sinus perforation was evaluated as prognostic factors of the healing outcomes following endodontic microsurgery using propensity score matching (PSM) based statistical analyses.
2. Materials and Methods
The clinical and radiographic records were collected from the Microscope Center of the Department of Conservative Dentistry at the Dental College of Yonsei University, Seoul, Korea. Data were from patients who underwent endodontic microsurgery in the center between March 2001 and March 2014. All patients had postoperative follow-up period of at least 1 year. The surgical outcomes of treatment group and control group were compared for each factor. To reduce the effect of selection bias in this study, the estimated propensity scores were used to match the cases. After matching, Cox proportional hazard regreesion analysis was performed for the estimation of the effect of potential prognostic factors on the outcome.
3. Results
For lesion type, 83 cases of endodontic-periodontal combined lesion group were matched to 166 cases of isolated endodontic lesion group. A Cox propotional harzard regression model with the matched data identified endodontic-periodontal combined lesion as a negative effect factor of the outcome (p=.001). For surgery type, 67 cases of re-surgery group were matched to 268 cases of surgery group. . There was no significant difference in prognosis between the surgery and re-surgery group (p>0.05). For through-and-through lesion, 18 cases of treatment group were matched to 72 cases of control group. There was no significant difference in prognosis between the cases with and without through-and through lesions (p>0.05). For sinus perforation, 17 cases with perforations were matched to 68 cases with no perforations. There was no significant difference in prognosis between the cases with and without perforations (p>005). For Endocem, 28 cases of Endocem group were matched to 112 cases of MTA group. There was no significant difference in prognosis between Endocem group and MTA group (p>0.05).
4. Conclusions
Lesion type was significant predictors of the outcome of endodontic microsurgery. Isolated endodontic lesion was significantly associated factors with better prognosis of endodontic micrusrgery. Surgery type, through-and-through lesion, sinus perforation and Endocem were not significantly associated factors on the outcome of the surgery. Various factors can be related to the prognosis of the endodontic microsurgery based on an analysis that utilized PSM, a useful statistical matching method for observational studies.ope
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
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