1,035 research outputs found
Nonlinear generation of THz vortex beams with tunable orbital angular momentum in si microdisks
No full textIn this poster presentation, we demonstrate waveguide-coupled microdisks that emit THz light with tunable orbital angular momentum. The topological charge of the THz light can be tuned by changing the driving infrared wavelengths in the difference-frequency generation process
Absorption and oral bioavailability of nanoencapsulated curcumin
No full textMany natural bioactive compounds bear various health-promoting benefits and are incorporated in functional foods. The utilization of the compounds in human body, or the bioavailability is usually not taken into consideration in the process of food formulation. In this Ph.D. study, the problem of the poor bioavailability of polyphenols, such as curcumin, was addressed by development of two nanoscale delivery systems, namely biopolymer micelles and nanoemulsions. It is known that solubilization and metabolism are two limiting factors for curcumin oral bioavailability. Using Caco-2 cell monolayers model, it was revealed that the permeation of solubilized curcumin was fast and by passive diffusion and that solubilization, not permeation of curcumin limited the absorption and the oral bioavailability. Subsequently, the solubilization of curcumin was improved by encapsulation of curcumin in biopolymer-based micelles and organogel-based formulations. Polymer micelles were generated from modified starch and self-synthesized modified epsilon polylysine. Upon encapsulation, the water solubility of curcumin was greatly increased and curcumin was stabilized against alkaline degradation. Moreover, the in vitro anti-cancer and cellular antioxidant activities of curcumin were also enhanced. On the other hand, food-grade curcumin organogel with high loading and in vitro bioaccessibility was developed. Based on the organogel, nanoemulsions were further generated to achieve faster and more complete digestion. The absorption mechanism of the nanoemulsion was examined using Caco-2 cell monolayer permeation assay and was suggested as the classic digestion-permeation route. It was further revealed that the oral bioavailability increased by 9-fold compared with unformulated curcumin on mice. Moreover, the toxicity of nanoemulsions was examined in vitro. Three tested food-grade nanoemulsions did not show significant toxicity on Caco-2 cell monolayers, which suggested that nanoemulsions may not affect the integrity of the small intestine epithelium. The biopolymer micelles and nanoemulsion formulations can be applied for oral delivery of other water-insoluble compounds for functional food application. And the formulation development method driven by absorption mechanisms also provides an example for future formulation studies.Ph. D.Includes bibliographical referencesIncludes vitaby Hailong Y
Coherently switching the focusing characteristics of all-dielectric metalenses
Get PDFFlat, gradient index, metasurface optics – in particular all-dielectric metalenses – have emerged and evolved over recent years as compact, lightweight alternative to their conventional bulk glass/crystal counterparts. Here we show that the focal properties of all-dielectric metalenses can be switched via coherent control, which is to say by changing the local electromagnetic field in the metalens plane rather than any physical or geometric property of the nanostructure or surrounding medium. The selective excitation of predominantly electric or magnetic resonant modes in the constituent cells of the metalens provides for switching, by design, of its phase profile enabling binary switching of focal length for a given lens type and, uniquely, switching between different (spherical and axicon) lens types
Cohomologically Full Rings
No full textInspired by a question raised by Eisenbud–Mustaţă–Stillman regarding the injectivity of maps from Ext modules to local cohomology modules and the work by the third author with Pham, we introduce a class of rings, which we call cohomologically full rings. This class of rings includes many well-known singularities: Cohen–Macaulay rings, Stanley–Reisner rings, F-pure rings in positive characteristics, and Du Bois singularities in characteristics 0. We prove many basic properties of cohomologically full rings, including their behavior under flat base change. We show that ideals defining these rings satisfy many desirable properties, in particular they have small cohomological and projective dimension. When R is a standard graded algebra over a field of characteristic 0, we show under certain conditions that being cohomologically full is equivalent to the intermediate local cohomology modules being generated in degree 0. Furthermore, we obtain Kodaira-type vanishing and strong bounds on the regularity of cohomologically full graded algebras
Development and application of the heat pulse method for soil physical measurements
Get PDFAccurate and continuous measurements of soil thermal and hydraulic properties are required for environmental, Earth and planetary science, and engineering applications, but they are not practically obtained by steady‐state methods. The heat pulse (HP) method is a transient method for determination of soil thermal properties and a wide range of other physical properties in laboratory and field conditions. The HP method is based on the line‐heat source solution of the radial heat flow equation. This literature review begins with a discussion of the evolution of the HP method and related applications, followed by the principal theories, data interpretation methods, and their differences. Important factors for HP probe construction are presented. The properties determined in unfrozen and frozen soils are discussed, followed by a discussion of limitations and perspectives for the application of this method. The paper closes with a brief overview of future needs and opportunities for further development and application of the HP method.This is an article published as He, Hailong, Miles F. Dyck, Robert Horton, Tusheng Ren, Keith L. Bristow, Jialong Lv, and Bingcheng Si. "Development and application of the heat pulse method for soil physical measurements." Reviews of Geophysics 54 (2018): 567-620. doi: 10.1029/2017RG000584. Posted with permission.</p
A new interpretive approach to an old issue under the WTO Turning the chapeau of GATT article XX into a wild card for greater domestic regulatory autonomy
Get PDFThe current anti-globalization movements can be seen as counter movements against neo-liberalism staged by social groups who have not benefited much from global economic integration. The WTO has been criticized for restricting domestic regulatory autonomy that could accommodate the interests of some of the disadvantaged social groups by having very narrow and strict exceptions to trade disciplines. Particularly, the WTO judiciary has repeatedly refused to exempt domestic regulatory measures having policy objectives beyond the closed-end list prescribed in the exception clause of GATT Article XX in its jurisprudence by declining various approaches to circumvent that list. However, I argue and try to demonstrate that the interpretation of the chapeau of Article XX by the Appellate Body in recent years can be used to reconstruct the chapeau to exempt highly flexible domestic measures with objectives listed in Article XX and even domestic measures with objectives not listed in Article XX. This is only a tentative development so far, not yet substantiated by explicit Appellate Body endorsement and successful application in WTO dispute settlement. But it should be followed in order to help the WTO endure and finally survive the attacks from the counter movements around the world. Nevertheless, the new interpretation and the interpretations of the closely related texts, particularly the lettered subparagraphs of Article XX, need tweaks to be more internally consistent with one another. A number of WTO Agreements also contain clauses serving basically the same purpose of Article XX, which is to exempt domestic measures otherwise in violation of trade disciplines. The new interpretation of Article XX needs to be transplanted into these Agreements as well to achieve internal consistency of the WTO jurisprudence. Therefore, after reconstructing the chapeau of Article XX, I will make my suggestions supported by careful analysis of the relevant legal texts and previous cases in these two regards.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2021-08-01The student, Hailong Jia, accepted the attached license on 2019-07-09 at 20:15.The student, Hailong Jia, submitted this Dissertation for approval on 2019-07-09 at 20:33.This Dissertation was approved for publication on 2019-07-11 at 16:12.DSpace SAF Submission Ingestion Package generated from Vireo submission #14232 on 2019-11-26 at 13:05:17Made available in DSpace on 2019-11-26T20:49:26Z (GMT). No. of bitstreams: 2
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An integrative method to decode regulatory logics in gene transcription
Get PDFabstract: Modeling of transcriptional regulatory networks (TRNs) has been increasingly used to dissect the nature of gene regulation. Inference of regulatory relationships among transcription factors (TFs) and genes, especially among multiple TFs, is still challenging. In this study, we introduced an integrative method, LogicTRN, to decode TF–TF interactions that form TF logics in regulating target genes. By combining cis-regulatory logics and transcriptional kinetics into one single model framework, LogicTRN can naturally integrate dynamic gene expression data and TF-DNA-binding signals in order to identify the TF logics and to reconstruct the underlying TRNs. We evaluated the newly developed methodology using simulation, comparison and application studies, and the results not only show their consistence with existing knowledge, but also demonstrate its ability to accurately reconstruct TRNs in biological complex systems.The final version of this article, as published in Nature Communications, can be viewed online at: http://www.nature.com/articles/s41467-017-01193-
RETRACTED ARTICLE: MiR-616 plays oncogenic role in hepatocellular carcinoma progression through suppressing PTEN expression and activating PI3K/AKT pathway
No full textWe, the Editors and Publisher of the journal Artificial Cells, Nanomedicine, and Biotechnology, have retracted the following article:Rina Sa, Huali Song, Meihua Wei, Hailong Su, Yao Hong, Lulu Zhou, & Yunfei Bai (2020) MiR-616 plays oncogenic role in hepatocellular carcinoma progression through suppressing PTEN expression and activating PI3K/AKT pathway. Artificial Cells, Nanomedicine, and Biotechnology, 48:1, 728–734. DOI: 10.1080/21691401.2019.1596928.It has come to our attention that the full authorship list and affiliations for this manuscript were changed after the article was accepted. We have contacted the corresponding author for an explanation, but we have not received a response. As determining authorship is core to the integrity of pubished work, we are therefore retracting the article. The corresponding author listed in this publication has been informed.We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’
Scientometrics of Scientometrics Based on Web of Science Core Collection Data between 1992 and 2020
No full textScientometrics is a quantitative and statistical approach that analyzes research on certain themes. It originated from information/library science but has been applied in various disciplines, including information science, library science, natural science, technology, engineering, medical sciences, and social sciences and humanities. Numerous scientometric studies have been carried out, but no study has attempted to investigate the overall research status of scientometrics. The objective of this study was to investigate the research status of scientometrics based on 16,225 publications archived in the Web of Science Core Collection between 1992 and 2020. The results show that there has been a marked increase in publications on scientometric studies over the past decades, with “Information Science Library Science” being the predominant discipline publishing scientometric studies, but scientometrics has been widely adopted in a variety of other disciplines (240 of 254 Web of Science categories). It was found that Web of Science, Vosviewer, and Scientometrics are the most utilized database, software, and journal for scientometric studies, respectively. The most productive author (Lutz Bornmann from the Max Planck Society, Germany), organization (University of Granada, Spain), and country (USA) are also identified. In addition, high-impact scientometric studies and the research landscape are analyzed through citation networks and the co-occurrence of keywords method
Exploring the combined impact of Project Portfolio Construction and steering on project portfolio performance
No full textIn recent years, project portfolio management (PPM) has received increased attention from both academics and practitioners. However, the development of the discipline is still in its infancy stage, and many aspects of PPM are still less understood. One particularly intriguing and important stream of research is concerned with the critical performance factors and the way in which they influence the overall project portfolio performance.
Empirical evidence suggests that both the periodic project portfolio construction (PPC) and the continuous project portfolio steering (PPS) are positively associated with project portfolio performance (PPP). Nevertheless, the question of 'how' has yet to be answered. To address this gap, this study set out to explore the way in which PPC and PPS could contribute to the PPP at an operationalised level. This study is dedicated to theory development by adopting the social constructionist approach. An investigation through the lens of General Systems Theory was carried out in the form of a single in-depth case study within a German construction machinery OEM. Qualitative data was collected and subsequently analysed by using thematic analysis.
The findings suggest that the four performance dimensions could be influenced by the eight essential elements of PPC and PPS. Their collaborative contributions to PPP appear to be indirect and mediated through an additional theoretical construct, i.e., project portfolio management capability. Based on the findings, the conceptualisation of the four theoretical constructs are determined and integrated into one visual framework to illustrate the associations at an operationalised level.
This study has partially addressed the identified gaps in the existing body of knowledge. The contribution is multi-fold. It contributes to the existing knowledge by providing a more complete and comprehensive framework that incorporates both the periodic and continuous notion of project portfolio management. The contribution to practice lies in its practical relevance, which offers the organisations a structured framework that could be used to systematically identify the gaps in their portfolio performance, determine the possible areas of improvement, and develop courses of action in related areas
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