| 271. |
- Li, Qin, et al.
(författare)
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Dynamics inside the cancer cell attractor reveal cell heterogeneity, limits of stability, and escape
- 2016
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 113:10, s. 2672-2677
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Tidskriftsartikel (refereegranskat)abstract
- The observed intercellular heterogeneity within a clonal cell population can be mapped as dynamical states clustered around an attractor point in gene expression space, owing to a balance between homeostatic forces and stochastic fluctuations. These dynamics have led to the cancer cell attractor conceptual model, with implications for both carcinogenesis and new therapeutic concepts. Immortalized and malignant EBV-carrying B-cell lines were used to explore this model and characterize the detailed structure of cell attractors. Any subpopulation selected from a population of cells repopulated the whole original basin of attraction within days to weeks. Cells at the basin edges were unstable and prone to apoptosis. Cells continuously changed states within their own attractor, thus driving the repopulation, as shown by fluorescent dye tracing. Perturbations of key regulatory genes induced a jump to a nearby attractor. Using the Fokker-Planck equation, this cell population behavior could be described as two virtual, opposing influences on the cells: one attracting toward the center and the other promoting diffusion in state space (noise). Transcriptome analysis suggests that these forces result from high-dimensional dynamics of the gene regulatory network. We propose that they can be generalized to all cancer cell populations and represent intrinsic behaviors of tumors, offering a previously unidentified characteristic for studying cancer.
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| 272. |
- Li, Qiang, et al.
(författare)
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Plasmonic devices for optical interconnect
- 2012
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Ingår i: Proc. - ICOCN: Int. Conf. Opt. Commun. Networks. - 9781467349574 ; , s. 72-74
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Konferensbidrag (refereegranskat)abstract
- Plasmonic nanowire waveguides, hybrid couplers and planar couplers are potential optical interconnect components, which feature small footprint, low loss, high coupling efficiency at optical communication wavelength, and could be integrated to photonic integrated circuits.
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| 273. |
- Li, Rongrong, et al.
(författare)
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Pressure, Feed Rate, and Abrasive Mass Flow Rate Influence on Surface Roughness for Recombinant Bamboo Abrasive Water Jet Cutting
- 2015
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Ingår i: BioResources. - : BioResources. - 1930-2126 .- 1930-2126. ; 10:2, s. 1998-2008
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Tidskriftsartikel (refereegranskat)abstract
- The effects of pressure, feed rate, and abrasive mass flow rate on surface roughness were investigated during abrasive water cutting of recombinant bamboo. Two different thicknesses (10 mm and 15 mm) of recombinant bamboo were cut in the longitudinal and transversal directions by abrasive water jet. All experiments were arranged using response surface methodology. The parameter Ra was selected to represent the surface roughness. The value of Ra increased with an increase in feed rate and abrasive mass flow rate, but decreased with an increase in pressure. The surface roughness was lower when cutting the fiber longitudinally than when cutting transversally.
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| 274. |
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| 275. |
- Li, Shu-Ming, et al.
(författare)
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Microwave-assisted method for the synthesis of cellulose-based composites and their thermal transformation to Mn2O3
- 2013
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Ingår i: Industrial crops and products (Print). - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 43, s. 751-756
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the synthesis of inorganic materials using cellulose as a template by thermal treatment of the precursor. Cellulose-based composites have been successfully fabricated by an efficient microwave-assisted method. The influences of heating time on the phases and shape of the precursor were investigated. Mn2O3 materials were obtained by thermal treatment of the precursor at 600 degrees C for 3 h in air. The morphology of cellulose composites was preserved after thermal transformation to form Mn2O3. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrometry (FTIR), energy-dispersive X-ray spectra (EDS). scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). A rapid microwave-assisted method with the thermal post-treatment provides a promising route for the fabrication of inorganic materials using natural polymer as a template.
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| 276. |
- Li, Shu-Ming, et al.
(författare)
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Rapid microwave-assisted preparation and characterization of cellulose-silver nanocomposites
- 2011
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 83:2, s. 422-429
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Tidskriftsartikel (refereegranskat)abstract
- A simple rapid and efficient microwave-assisted synthesis of cellulose-silver nanocomposites with silver nanoparticles homogeneously dispersed in the cellulose matrix using cellulose solution AgNO3 and ascorbic acid in N N-dimethylacetamide (DMAc) is reported The cellulose solution was prepared by the dissolution of microcrystalline cellulose in a solvent system of lithium chloride (LiCl)/DMAc The effects of the microwave heating times and ascorbic acid concentration on the nanocomposites were investigated The microstructure size morphology and thermal properties of these nanocomposites were analyzed with X-ray diffraction (XRD) Fourier transform infrared (FT-IR) thermogravimetric analysis (TG) differential scanning calorimetric analysis (DSC) and scanning electron microscopy (SEM) The results revealed that the ascorbic acid concentration played an important role in the phase of the nanocomposites This work provided a promising way to prepare cellulose-silver nanocomposites with good dispersity.
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| 277. |
- Li, Shu-Ming, et al.
(författare)
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Synthesis of cellulose-calcium silicate nanocomposites in ethanol/water mixed solvents and their characterization
- 2010
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 80:1, s. 270-275
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Tidskriftsartikel (refereegranskat)abstract
- Cellulose-calcium silicate nanocomposites with calcium silicate nanoparticles homogeneously dispersed in the cellulose matrix have been successfully synthesized using cellulose solution, Ca(NO3)(2)center dot 4H(2)O and Na2SiO3 center dot 9H(2)O in ethanol/water mixed solvents at room temperature for 24 h. The cellulose solution was previously prepared by the dissolution of cellulose in a solvent system of N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl). The feeding order had an influence on the morphology of the cellulose-calcium silicate nanocomposites and the size of the calcium silicate particles. The cellulose in nanocomposites showed cellulose type II crystalline structure. The products were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG), differential scanning calorimetric analysis (DSC), Fourier transform infrared spectrometry (FT-IR), energy-dispersive X-ray spectra (EDS), and scanning electron microscopy (SEM).
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| 278. |
- Li, S., et al.
(författare)
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New Strategy for Black Phosphorus Crystal Growth through Ternary Clathrate
- 2017
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7505 .- 1528-7483. ; 17:12, s. 6579-6585
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Tidskriftsartikel (refereegranskat)abstract
- We are reporting a new synthetic strategy to grow large-sized black phosphorus (Black-P) crystals through a ternary clathrate Sn24P22-xI8, under lower synthetic temperature and pressure. The Black-P crystals are found grown in situ at the site where the solid clathrate originally resides, which suggests chemical vapor mineralizer does not play a critical role for the Black-P formation. More detailed systematical studies have indicated the P vacancies in the framework of the ternary clathrate Sn24P22-xI8 are important for the subsequent Black-P from phosphorus vapors, and a likely vapor solid solid model is responsible for the Black-P crystal growth. The obtained room temperature mobility mu is similar to 350 cm(2)/V.s from Hall measurements at mechanically cleaved flakes, where noticeable microcracks are visible. The obtained high mobility value further suggests the high quality of the Black-P crystals synthesized through this route.
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| 279. |
- Li, Suyang, et al.
(författare)
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One-pot fabrication of Mo1-xWxS2 alloy nanosheets as SERS substrates with highly Raman enhancement effect and long-term stability
- 2022
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Ingår i: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425 .- 1873-3557. ; 279, s. 121465-
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Tidskriftsartikel (refereegranskat)abstract
- A new Mo1-xWxS2 two-dimensional nanosheets were prepared by the one-pot method. After certain Mo atoms in MoS2 were replaced by W ones in a hydrothermal reduction procedure, Mo1-xWxS2 was formed on the Mo foil. Well enhanced Mo1-xWxS2 nanosheets were prepared when the sodium tungstate concentration got under control. Various characterizations were carried out, which indicate that Mo1-xWxS2 nanosheets with good crystallinity. Compared with MoS2, the Raman intensity of Rhodamine 6G (10-6 M) was amplified by 1.7 times with Mo1-xWxS2 nanosheets as the substrate. The characteristic Raman peaks could still be clearly distinguished until the concentration of Rhodamine 6G (R6G), Methylene blue (MB) and Crystal violet (CV) down to 10-8, 10-8 and 10- 7 M, respectively. With abundant edge active sites that facilitate charge transfer, Mo1-xWxS2 nanosheets could better enhance SERS signals of target detection molecules and get a good linear relationship exists within the concentration and Raman peak strength. In addition, R6G SERS detection also shows excellent reproducibility and long-term stability of this TMDs SERS substrate.
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| 280. |
- Li, Xiaowu, et al.
(författare)
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On a Family of Trimodal Distributions
- 2014
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Ingår i: Communications in Statistics - Theory and Methods. - : Taylor & Francis. - 0361-0926 .- 1532-415X. ; 43:14, s. 2886-2896
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Tidskriftsartikel (refereegranskat)abstract
- In this article, a family of trimodal distributions is presented. The distributional properties and some of the inferential aspects of this family of trimodal distributions are discussed. We propose a moment based estimator as well as a maximum likelihood estimator of the parameters. A numerical simulation is conducted to evaluate the finite sample performances of the proposed estimators. A real data example is analyzed for illustration.
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