1,120 research outputs found
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
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
A0.13μm CMOSΔΣ fractional-N frequency synthesizer for WLAN transceivers
No full textA fractional-N frequency synthesizer fabricated in a0.13μm CMOS technology is presented for the application of IEEE802.11 b/g wireless local area network(WLAN) transceivers. A monolithic LC voltage controlled oscillator(VCO) is implemented with an on-chip symmetric inductor. The fractional-N frequency divider consists of a pulse swallow frequency divider and a3rd-order multistage noise shaping(MASH)ΔΣ modulator with noise-shaped dithering techniques. Measurement results show that in all channels, phase noise of the synthesizer achieves-93 dBc/Hz and-118 dBc/Hz in band and out of band respectively with a phase-frequency detector(PFD) frequency of20 MHz and a loop bandwidth of100 kHz. The integrated RMS phase error is no more than0.8°. The proposed synthesizer consumes8.4 mW from a1.2 V supply and occupies an area of0.86 mm2.?2011 Chinese Institute of Electronics
Xianggang Ya re dai sen lin fu xiu de sheng tai ping gu
No full textAfter 8-19 years of restoration, therefore, there were improvements in the quality of the restored sites in terms of vegetation structure, soil productivity and nutrient cycling. While the degree of improvement increases with age of the plantations, the qualities of the restored sites still lag behind that of the mature forest.Based on the above findings, an assessment system is developed for the evaluation of restoration progress in the subtropical region. It includes a set of ecological indicators including: species diversity, timber transaction areas, standard deviation of tree height, total crown area, sapling density, species invasion, soil bulk density, soil water-holding capacity, organic carbon content, TKN, pH, seed bank, soil mineralization rate and litter decomposition rate. These findings have, therefore, filled the knowledge gap that there is virtually no study on the ecological assessment of restored subtropical forests in the literature. In addition, the goals and strategy of ecological restoration in Hong Kong are also discussed in the thesis.Ecological rehabilitation with exotic species, particularly nitrogen-fixing legumes, is capable of ameliorating the degraded soils. While there is no change in the soil texture, ecological rehabilitation lowered pH and bulk density, increased organic carbon (OC) and total Kjeldahl nitrogen (TKN) contents, and elevated field capacity and available water contents of the soil. Intra-layer differences in OC and TKN were widened in R89, a trend comparable to TO. Ammonification and nitrification were detected in the restored soils, where NH4-N predominated over NO3-N and net N mineralization was higher in R89 than R95 and R00. In contrast, TO is dominated by NO3-N and net N mineralization is higher than the restored soils.Ecological succession is happening in all the restored sites and the evidence of proof include: stem exclusion (declining density); steady increase of tall trees (>12m); invasion of grass, fern, vine and climber though few; increase in species diversity; canopy closure; decreasing standing litter but a simultaneous increase in fruits and seeds; increase of DBH, transaction areas and crown area, etc. Overall, the restored forests are inferior to the mature forest in terms of biodiversity and stand complexity.Keywords: ecological assessment, forest rehabilitation, soil destruction sites, subtropical areaLitterfall production was characterized by bimodal peaks in TTEBA and by a single peak in TO. Peak production in August through September in Tai Tong was caused by mechanical breakage during the passage of tropical cyclones. In contrast, litterfall in TO was less easily affected by cyclones. Total litterfall production was in the order of TO ≥ R00 > R89 ≥ R95. Litterfall production was only positively correlated with canopy closure of the forests. Nutrient return was higher in the dry season than the wet season, which is governed by the quantity of litterfall.The decomposition constants (k) for Acacia mangium and Schima superba foliage litter decreased in the order of TO > R89 > R00 > R95. It is positively correlated with SOC, TKN, TP, clay percentage and FC water of the soils but negatively with soil bulk density (p<0.05). Among the restored sites, the half life (T50) of leaf litter was shortest for Acacia mangium (92.4 days) and Schima superba (105.0 days) in R89. Overall, litter decomposition is faster in TO than any of the restored sites.The present study investigates the successional development of three restored subtropical forests in Hong Kong, with special emphasis on the development of an assessment system suitable for the evaluation of restoration progress. The restored forests, aged 8 (R00), 13 (R95) and 19 (R89) years, were established on severely degraded lands in Tai Tong East Borrow Area (TTEBA) depleted of vegetation and top soil cover. The vegetation, soil and nutrient cycling processes of these restored forests were benchmarked against a mature forest (TO), aged 300+ years, characterized by high biodiversity and undisturbed soil. The restored forests are dominated by exotic species, mostly nitrogen-fixing legumes, and the mature forest by broad-leaved native species. The objectives of this thesis are threefold: (a) to assess the ecological development of the restored forests; (b) to develop an assessment system that can be employed to assess restoration progress; and (c) to revisit the goals and strategy of ecological restoration in Hong Kong.Zheng, Hailong."October 2009."Source: Dissertation Abstracts International, Volume: 72-01, Section: A, page: .Thesis (Ph.D.)--Chinese University of Hong Kong, 2010.Includes bibliographical references (leaves 187-209).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Abstract also in Chinese
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
No full textThe 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
JIA-DISSERTATION-2019.pdf: 1800009 bytes, checksum: fde3dbcc5755036f584ae7759c401f76 (MD5)
LICENSE.txt: 4208 bytes, checksum: 1c1dac8caf1650c86e36a7103dda6b3e (MD5)
Previous issue date: 2019-07-11Embargo set by: Seth Robbins for item 112951
Lift date: 2021-11-26T20:49:41Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Only Restriction Lifted for Item 112951 on 2021-11-27T10:15:23Z
An asymmetric MOSFET-C band-pass filter with on-chip charge pump auto-tuning
No full textAn asymmetric MOSFET-C band-pass filter(BPF)with on chip charge pump auto-tuning is presented.It is implemented in UMC (United Manufacturing Corporation)0.18μm CMOS process technology. The filter system with auto-tuning uses a master-slave technique for continuous tuning in which the charge pump OUtputs 2.663 V, much higher than the power supply voltage, to improve the linearity of the filter. The main filter with third order low-pass and second order high-pass properties is an asymmetric band-pass filter with bandwidth of 2.730-5.340 MHz. The in-band third order harmonic input intercept point(HP3) is 16.621 dBm,wim 50 Ω as the source impedance. The input referred noise iS about 47.455μVrms. The main filter dissipates 3.528 mW while the auto-tuning system dissipates 2.412 mW from a 1.8 V power supply. The filter with the auto-tuning system occupies 0.592 mm~2 and it can be utilized in GPS (global positioning system)and Bluetooth systems
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’
Global Change Modulates Microbial Carbon Use Efficiency: Mechanisms and Impacts on Soil Organic Carbon Dynamics
No full textABSTRACT Microbial carbon use efficiency (CUE) is a key parameter of initial microbial utilization of organic matter in soil. The responses of CUE to global change factors (GCFs) remain unclear due to their multiple effects and interactions. Here, this study generalized 385 observations obtained using various methods, including 13 C‐/ 14 C‐labeled substrates, 18 O‐labeled water, stoichiometric modeling, and others. The effects of climate change (drought, precipitation, warming), fertilization (nitrogen addition, phosphorus addition, potassium addition, and nitrogen fertilization combined with phosphorus and potassium), land use conversion, and natural restoration, were evaluated along with their 16 associated GCFs on CUE. CUE was insensitive to climate change factors and most fertilization practices, maintaining a mean value of 0.36 under global change scenarios. Farmland conversion to forest and vegetation restoration decreased CUE by 11% and 17%, respectively. Grassland restoration increased CUE by 41%, indicating that grasslands have high potential for soil carbon accrual. Nitrogen fertilization combined with phosphorus and potassium increased CUE by 18% because the combined application of nutrients allows plants to produce organic matter sources with high‐quality and decreases nutrient limitations for microorganisms. Increase in soil pH induced by GCFs leads to higher CUE. The CUE was decoupled from soil organic carbon content under several global change scenarios (e.g., warming, fertilization), suggesting that this relationship is not universally consistent across GCFs. This study provides a new perspective on the responses of CUE to GCFs and deepens our understanding of the global change effects on microbial physiology with consequences for soil carbon cycling.Fundamental Research Funds for the Central Universities https://doi.org/10.13039/501100012226National Natural Science Foundation of China https://doi.org/10.13039/50110000180
- …
