| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 4. |
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| 5. |
- Abeysinghe, Kasun S., et al.
(författare)
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Total mercury and methylmercury concentrations over a gradient of contamination in earthworms living in rice paddy soil
- 2017
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 36:5, s. 1202-1210
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Tidskriftsartikel (refereegranskat)abstract
- Mercury (Hg) deposited from emissions or from local contamination, can have serious health effects on humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil-dwelling organisms that have been used as indicators of Hg bioavailability; however, the MeHg concentrations they accumulate in rice paddy environments are not well known. Earthworm and soil samples were collected from rice paddies at progressive distances from abandoned mercury mines in Guizhou, China, and at control sites without a history of Hg mining. Total Hg (THg) and MeHg concentrations declined in soil and earthworms as distance increased from the mines, but the percentage of THg that was MeHg, and the bioaccumulation factors in earthworms, increased over this gradient. This escalation in methylation and the incursion of MeHg into earthworms may be influenced by more acidic soil conditions and higher organic content further from the mines. In areas where the source of Hg is deposition, especially in water-logged and acidic rice paddy soil, earthworms may biomagnify MeHg more than was previously reported. It is emphasized that rice paddy environments affected by acidifying deposition may be widely dispersed throughout Asia.
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| 6. |
- Abolfathi, Bela, et al.
(författare)
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The Fourteenth Data Release of the Sloan Digital Sky Survey : First Spectroscopic Data from the Extended Baryon Oscillation Spectroscopic Survey and from the Second Phase of the Apache Point Observatory Galactic Evolution Experiment
- 2018
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Ingår i: Astrophysical Journal Supplement Series. - : IOP Publishing Ltd. - 0067-0049 .- 1538-4365. ; 235:2
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Tidskriftsartikel (refereegranskat)abstract
- The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014-2016 July) public. Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey; the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data-driven machine-learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from the SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS web site (www.sdss.org) has been updated for this release and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020 and will be followed by SDSS-V.
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| 7. |
- Blanton, Michael R., et al.
(författare)
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Sloan Digital Sky Survey IV : Mapping the Milky Way, Nearby Galaxies, and the Distant Universe
- 2017
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Ingår i: Astronomical Journal. - : IOP Publishing Ltd. - 0004-6256 .- 1538-3881. ; 154:1
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Tidskriftsartikel (refereegranskat)abstract
- We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and. high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z similar to 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z similar to 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs. and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the. Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July.
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| 8. |
- Bu, C. S., et al.
(författare)
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Iron based oxygen-carrier-aided oxy-fuel combustion of coal char: Reactivity and oxygen transfer mechanism
- 2023
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 333
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Tidskriftsartikel (refereegranskat)abstract
- Adding an active oxygen carrier to the inert bed material may favor the oxygen distribution in fluidized bed (FB) combustors. This so-called method “Oxygen-carrier-aided combustion, OCAC” has been applied recently to air combustion in FB boilers, but could also be potentially interesting in oxy-fuel combustion. Here we analyze OCAC in oxy-fuel combustion by experimental determination of the reactivity of char from three coals (lignite, bituminous and anthracite coal) using three oxygen carriers (OC, analytical reagent Fe2O3, hematite, and steel slag). The tests were conducted in a micro thermo-gravimetric analyzer (micro-TGA) and the combustion kinetics was determined for the nine combinations of char and OC. Additional tests were conducted in a macro-TGA i.e., much sample in a big ceramic crucible, to evaluate the phase composition and crystal quality using X-ray diffraction (XRD) to the combustion residues collected at various degrees of carbon conversion (0.2, 0.5, and 0.8). The results show that the burnout temperature decreases with OCs as the combustion rate increases, while the ignition temperature hardly changes. The enhancement of the rate of char combustion by OCs is in the following order: steel slag < hematite < AR-Fe2O3. The lower the fuel rank, the stronger the effect of the oxygen carrier. The combustion kinetics of chars using OC has a higher activation energy and pre-exponential factor than pure char. The enlarged lattice constant of Fe2O3 measured by XRD during the char combustion indicates that the redox reactions of Fe2O3 accelerate the oxidization of char by enhancing the rate of oxygen transport to the carbon surface.
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| 9. |
- Cheng, Chao, et al.
(författare)
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Mosaic chromosomal alterations are associated with increased lung cancer risk : insight from the INTEGRAL-ILCCO cohort analysis
- 2023
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Ingår i: Journal of Thoracic Oncology. - : Elsevier. - 1556-0864 .- 1556-1380.
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Mosaic chromosomal alterations (mCAs) detected in white blood cells represent a type of clonal hematopoiesis (CH) that is understudied compared with CH-related somatic mutations. A few recent studies indicated their potential link with nonhematological cancers, especially lung cancer. Methods: In this study, we investigated the association between mCAs and lung cancer using the high-density genotyping data from the OncoArray study of INTEGRAL-ILCCO, the largest single genetic study of lung cancer with 18,221 lung cancer cases and 14,825 cancer-free controls. Results: We identified a comprehensive list of autosomal mCAs, ChrX mCAs, and mosaic ChrY (mChrY) losses from these samples. Autosomal mCAs were detected in 4.3% of subjects, in addition to ChrX mCAs in 3.6% of females and mChrY losses in 9.6% of males. Multivariable logistic regression analysis indicated that the presence of autosomal mCAs in white blood cells was associated with an increased lung cancer risk after adjusting for key confounding factors, including age, sex, smoking status, and race. This association was mainly driven by a specific type of mCAs: copy-neutral loss of heterozygosity on autosomal chromosomes. The association between autosome copy-neutral loss of heterozygosity and increased risk of lung cancer was further confirmed in two major histologic subtypes, lung adenocarcinoma and squamous cell carcinoma. In addition, we observed a significant increase of ChrX mCAs and mChrY losses in smokers compared with nonsmokers and racial differences in certain types of mCA events. Conclusions: Our study established a link between mCAs in white blood cells and increased risk of lung cancer.
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| 10. |
- Deng, Min, et al.
(författare)
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Genome-wide association analyses in Han Chinese identify two new susceptibility loci for amyotrophic lateral sclerosis
- 2013
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 45:6, s. 697-
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Tidskriftsartikel (refereegranskat)abstract
- To identify susceptibility genes for amyotrophic lateral sclerosis (ALS), we conducted a genome-wide association study (GWAS) in 506 individuals with sporadic ALS and 1,859 controls of Han Chinese ancestry. Ninety top SNPs suggested by the current GWAS and 6 SNPs identified by previous GWAS were analyzed in an independent cohort of 706 individuals with ALS and 1,777 controls of Han Chinese ancestry. We discovered two new susceptibility loci for ALS at 1q32 (CAMK1G, rs6703183, P-combined = 2.92 x 10(-8), odds ratio (OR) = 1.31) and 22p11 (CABIN1 and SUSD2, rs8141797, P-combined = 2.35 x 10(-9), OR = 1.52). These two loci explain 12.48% of the overall variance in disease risk in the Han Chinese population. We found no association evidence for the previously reported loci in the Han Chinese population, suggesting genetic heterogeneity of disease susceptibility for ALS between ancestry groups. Our study identifies two new susceptibility loci and suggests new pathogenic mechanisms of ALS.
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| 11. |
- Fan, Hongchao, et al.
(författare)
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An automatic approach for the typification of façade structures
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Ingår i: ISPRS journal of photogrammetry and remote sensing (Print). - 0924-2716 .- 1872-8235.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Typification is a well-established operator of map generalization. Although it is widely used in many existing research fields, less discussion has been devoted to the quality of typification. This paper presents a user survey for the evaluation of different typification results of façade structures under different constraints. The survey shows that preservation of the shape of the features is the most important constraint for a reasonable typification process, which has also been quantitatively verified by calculating the similarities between the typified façades and the original façade using attributed relational graph (ARG) and nested earth mover’s distance (NEMD) algorithms. Based on that, an algorithm is developed to generate perceivably reasonable representation from the original facade with decreasing map scale. The algorithm is implemented and tested on a number of façades. Experiments reveal that the typification can be automatically conducted and can create results which are well associated with the original façades.
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| 12. |
- Fan, Hongchao, et al.
(författare)
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Shell model representation as a substitute of LOD3 for 3D modeling in CityGML
- 2011
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Ingår i: Geo-spatial Information Science. - : Informa UK Limited. - 1009-5020 .- 1993-5153. ; 14:2, s. 78-84
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Tidskriftsartikel (refereegranskat)abstract
- The OGC standard for 3D city modeling is widely used in an increasing number of applications. It defines five consecutive Levels of Detail (LoD0 to LoD4 with increasing accuracy and structural complexity), in which LoD3 includes all exterior appearances and geometrical details and subsequently requires much storage space. A new LoD is introduced as shell model with the exterior shell of the LoD3 model and the opening objects like windows, doors as well as smaller façade objects are projected onto walls. In this paper, a user survey is presented. The results of this survey show that the shell model can give users almost the same visual impression as the LoD3 model. Furthermroe, algorithms are developed to extract the shell model from LoD3 model. Experiments show that this shell model can reduce up to 90% storage of the original LoD3 model. Therefore, on one hand it can be used as a substitute for a LoD3 model for the visualization on small displays. On the other hand, it can be treated as a sub-level of detail (SLoD3) in CityGML, since it retains almost the same amount of information but requires much less storage space.
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| 13. |
- Gu, Dong, et al.
(författare)
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Growth of Single-Crystal Mesoporous Carbons with Im(3)over-barm Symmetry
- 2010
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 22:16, s. 4828-4833
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Tidskriftsartikel (refereegranskat)abstract
- Highly ordered mesoporous carbon FDU-16 rhombic dodecahedral single crystals with body-centered cubic structure (space group Im (3) over barm) have been successfully synthesized by employing an organic-organic assembly of triblock copolymer Pluronic F127 (EO106PO70EO106) and phenol/formaldehyde resol in basic aqueous solution. Synthetic factors (including reaction time, temperature, and stirring rate) are explored for controlling the formation of rhombic dodecahedral single crystals. The optimal stirring rate and the reaction temperature are 300 +/- 10 rpm and similar to 66 degrees C, respectively. High-resolution scanning electron microscopy (HRSEM), scanning transmission electron microscopy (STEM), and ultramicrotomy are applied to study the fine structures of the carbon single crystals. The mesopores are arranged in body-centered cubic symmetry throughout the entire particle. Surface steps are clearly observed in the {110} surface, which suggests a layer-by-layer growth of the mesoporous carbon FDU-16 single crystals. Cryo-SEM results from the reactant solution confirm the formation of resol/F127 unit micelles, further supporting the layer-by-layer growth process. The mesoporous carbon FDU-16 single crystals grow up to the final size of 2-4 mu m within 2 days. These findings may have consequences for the growth mechanism of other carbon materials in aqueous solution; moreover, the high-quality single crystals also have potential applications in nanodevice technologies.
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| 14. |
- Guo, S., et al.
(författare)
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Evidence for pseudospin-chiral quartet bands in the presence of octupole correlations
- 2020
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Ingår i: Physics Letters B. - : ELSEVIER. - 0370-2693 .- 1873-2445. ; 807
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Tidskriftsartikel (refereegranskat)abstract
- Three nearly degenerate pairs of doublet bands are identified in Ba-131. Two of them, with positive-parity, are interpreted as pseudospin-chiral quartet bands. This is the first time that a complete set of chiral doublet bands built on the pseudospin partners pi(d(5/2), g(7/2)) is observed. The chiral bands with opposite parity built on 3-quasiparticle configurations are directly connected by many E1 transitions, without involving an intermediary non-chiral configuration. The observed band structures in Ba-131 have been investigated by using the reflection-asymmetric particle rotor model. The energies and the electromagnetic transition ratios of the three pairs of doublet bands observed in Ba-131 are reproduced and they are interpreted as chiral doublet bands with three-quasiparticle configurations. It is the first time that multiple chiral bands are observed in the presence of enhanced octupole correlations and pseudospin symmetry.
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| 15. |
- Huang, Zi-Nan, et al.
(författare)
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Analysis of the stress field in the reactor vessel of the China Initiative Accelerator Driven System during postulated ULOF and UTOP transients
- 2023
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 194
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Tidskriftsartikel (refereegranskat)abstract
- The China Initiative Accelerator Driven System (CiADS) was proposed by China Academy of Science since 2015. The subcritical reactor in CiADS is a liquid Lead Bismuth Eutectic (LBE) cooled fast reactor. When the reactor core is in operation, the LBE coolant will directly contact and corrode the inner surface of reactor vessel. Due to the high temperature, the corrosion will be more severe. If the stress on the reactor vessel exceeds the limit, the plastic deformation will occur, leading to the generation and expansion of defects and cracks, and the safety of the reactor will be affected. Therefore, evaluating the stress field of the reactor vessel under different operating conditions is a very important research project. In this paper, the finite element analysis software ADINA was applied to analyze the reactor vessel in CiADS, and the ASME Code was used as stress assessment standards. We can preliminarily prove that the stress assessments of the vessel during the postulated Unprotected Loss of Flow (ULOF) accidents satisfy the requirements of ASME Code. The limit reactivity insertion to protect the vessel from plastic deformation is 0.58$ in the postulated Unprotected Transient over Power (UTOP) accidents based on our current results. Therefore, we can preliminarily conclude that the current material selection and structural design of the reactor vessel in CiADS could survive most of the postulated transient accidents considering the stress effect.
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| 16. |
- Kristanl, Matej, et al.
(författare)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 17. |
- Lian, Ming, et al.
(författare)
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Lidar mapping of atmospheric atomic mercury in the Wanshan area, China
- 2018
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 240, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- A novel mobile laser radar system was used for mapping gaseous atomic mercury (Hg0) atmospheric pollution in the Wanshan district, south of Tongren City, Guizhou Province, China. This area is heavily impacted by legacy mercury from now abandoned mining activities. Differential absorption lidar measurements were supplemented by localized point monitoring using a Lumex RA-915M Zeeman modulation mercury analyzer. Range-resolved concentration measurements in different directions were performed. Concentrations in the lower atmospheric layers often exceeded levels of 100 ng/m3 for March conditions with temperature ranging from 5 °C to 20 °C. A flux measurement of Hg0 over a vertical cross section of 0.12 km2 resulted in about 29 g/h. Vertical lidar sounding at night revealed quickly falling Hg0 concentrations with height. This is the first lidar mapping demonstration in a heavily mercury-polluted area in China, illustrating the lidar potential in complementing point monitors.
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| 18. |
- Liu, Wei, et al.
(författare)
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Pickering multiphase materials using plant-based cellulosic micro/nanoparticles
- 2024
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Ingår i: Aggregate. - 2692-4560.
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Forskningsöversikt (refereegranskat)abstract
- Pickering multiphase systems stabilized by solid particles have recently attracted increasing attention due to their excellent stability. Among various solid stabilizers, natural and renewable cellulosic micro/nanoparticles that are derived from agricultural and forestry sources have become promising candidates for Pickering stabilization due to their unique morphological features and tunable surface properties. In this review, recent progress on forming and stabilizing Pickering multiphase systems using cellulosic colloidal particles is summarized, including the physicochemical factors affecting their assembly at the interfaces and the preparation methods suitable for producing Pickering emulsions. In addition, relevant application prospects of corresponding Pickering multiphase materials are outlined. Finally, current challenges and future perspectives of such renewable Pickering multiphase systems are presented. This review aims to encourage the utilization of cellulosic micro/nanoparticles as key components in the development of Pickering systems, leading to enhanced performance and unique functionalities. image
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| 19. |
- Lock, Nina, et al.
(författare)
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Copper doped TiO2 nanoparticles characterized by X-ray absorption spectroscopy, total scattering, and powder diffraction - a benchmark structure-property study
- 2013
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9234 .- 1477-9226. ; 42:26, s. 9555-9564
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Tidskriftsartikel (refereegranskat)abstract
- Metal functionalized nanoparticles potentially have improved properties e. g. in catalytic applications, but their precise structures are often very challenging to determine. Here we report a structural benchmark study based on tetragonal anatase TiO2 nanoparticles containing 0-2 wt% copper. The particles were synthesized by continuous flow synthesis under supercritical water-isopropanol conditions. Size determination using synchrotron PXRD, TEM, and X-ray total scattering reveals 5-7 nm monodisperse particles. The precise dopant structure and thermal stability of the highly crystalline powders were characterized by X-ray absorption spectroscopy and multi-temperature synchrotron PXRD (300-1000 K). The combined evidence reveals that copper is present as a dopant on the particle surfaces, most likely in an amorphous oxide or hydroxide shell. UV-VIS spectroscopy shows that copper presence at concentrations higher than 0.3 wt% lowers the band gap energy. The particles are unaffected by heating to 600 K, while growth and partial transformation to rutile TiO2 occur at higher temperatures. Anisotropic unit cell behavior of anatase is observed as a consequence of the particle growth (a decreases and c increases).
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| 20. |
- Lv, B. F., et al.
(författare)
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Chirality of Nd-135 reexamined : Evidence for multiple chiral doublet bands
- 2019
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 100:2
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Tidskriftsartikel (refereegranskat)abstract
- One new pair of positive-parity chiral doublet bands have been identified in the odd-A nucleus Nd-135 which together with the previously reported negative-parity chiral doublet bands constitute a third case of multiple chiral doublet (M chi D) bands in the A approximate to 130 mass region. The properties of the M chi D bands are well reproduced by constrained covariant density functional theory and particle rotor model calculations. The newly observed M chi D bands in Nd-135 represents an important milestone in supporting the existence of M chi D in nuclei.
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| 21. |
- Mao, Bo, et al.
(författare)
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City Model Generalization Quality Assessment using Nested Structure of Earth Mover’s Distance
- 2010
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- To evaluate the quality of city model generalization, an attributed relational graph (ARG) is used to represent the features of city models and Nested structure of Earth Mover's Distance (NEMD) is employed to calculate the visual similarity of the ARGs. The experiments show that the proposed method is coherence with user survey result.
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| 22. |
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| 23. |
- Meng, Fanqi, et al.
(författare)
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Relativistic Doppler Frequency Up-conversion and Probing the Initial Relaxation of a Non-Equilibrium Electron-Hole Plasma in Silicon
- 2015
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Ingår i: 2015 40TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ). - : IEEE. - 9781479982721 - 9781479982714
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Konferensbidrag (refereegranskat)abstract
- we demonstrate experimentally the relativistic Doppler frequency up-conversion of the THz pulses from the counter-propagating ionized plasma front in silicon. The observed frequency up-conversion can be well modeled by the 1D FDTD simulations if significant short scattering time (well below 10 fs) in the plasma is assumed. To further elucidate the scattering rate in the electro-hole plasma, we performed pump probe experiment employing ultra-broadband (150 THz) THz-Mid-Infrared pulse. The results show the scattering time decreases from similar to 200 fs down to similar to 20 fs when the carrier density increases up to 10(19)-cm(-3), and then saturates for higher densities. Such scattering time dependence on plasma carrier density can be very well fitted by the Drude model for thermalized electron-holes, and the saturation behavior is attributed to electron-hole phase-space restriction as the plasma becomes degenerate. The resultant much shorter scattering time measured with non-thermalized plasma is in good accordance with the Doppler experiment, which demonstrates Doppler geometry an effective method for probing non-equilibrium plasma dynamics.
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| 24. |
- Meng, Fanqi, et al.
(författare)
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Ultrafast dynamic conductivity and scattering rate saturation of photoexcited charge carriers in silicon investigated with a midinfrared continuum probe
- 2015
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - : American Physical Society. - 1098-0121 .- 1550-235X. ; 91:7, s. 075201-
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Tidskriftsartikel (refereegranskat)abstract
- We employ ultrabroadband terahertz-midinfrared probe pulses to characterize the optical response of photoinduced charge-carrier plasmas in high-resistivity silicon in a reflection geometry, over a wide range of excitation densities (10(15)-10(19) cm(-3)) at room temperature. In contrast to conventional terahertz spectroscopy studies, this enables one to directly cover the frequency range encompassing the resultant plasma frequencies. The intensity reflection spectra of the thermalized plasma, measured using sum-frequency (up-conversion) detection of the probe pulses, can be modeled well by a standard Drude model with a density-dependent momentum scattering time of similar to 200 fs at low densities, reaching similar to 20 fs for densities of similar to 10(19) cm(-3), where the increase of the scattering rate saturates. This behavior can be reproduced well with theoretical results based on the generalized Drude approach for the electron-hole scattering rate, where the saturation occurs due to phase-space restrictions as the plasma becomes degenerate. We also study the initial subpicosecond temporal development of the Drude response and discuss the observed rise in the scattering time in terms of initial charge-carrier relaxation, as well as the optical response of the photoexcited sample as predicted by finite-difference time-domain simulations.
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| 25. |
- Meng, Mei, et al.
(författare)
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Accumulation of total mercury and methylmercury in rice plants collected from different mining areas in China
- 2014
-
Ingår i: Environmental Pollution. - : Pergamon Press. - 0269-7491 .- 1873-6424. ; 184, s. 179-186
-
Tidskriftsartikel (refereegranskat)abstract
- A total of 155 rice plants were collected from ten mining areas in three provinces of China (Hunan, Guizhou and Guangdong), where most of mercury (Hg) mining takes place in China. During the harvest season, whole rice plants were sampled and divided into root, stalk & leaf, husk and seed (brown rice), together with soil from root zone. Although the degree of Hg contamination varied significantly among different mining areas, rice seed showed the highest ability for methylmercury (MeHg) accumulation. Both concentrations of total mercury (THg) and MeHg in rice plants were significantly correlated with Hg levels in soil, indicating soil is still an important source for both inorganic mercury (IHg) and MeHg in rice plants. The obvious discrepancy between the distribution patterns of THg and MeHg reflected different pathways of IHg and MeHg accumulation. Water soluble Hg may play more important role in MeHg accumulation in rice plants.
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| 26. |
- Meng, Qing-Ling, et al.
(författare)
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Anatomic study of maximum intensity projection of the membranous labyrinth and the internal auditory meatus- MRI scan in 16 Chinese adults
- 2007
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 127:11, s. 1150-6
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Tidskriftsartikel (refereegranskat)abstract
- CONCLUSION: Three-dimensional reconstruction of maximum intensity projection (MIP) might document objectively, stereoscopically and directly the minute structures of the membranous labyrinth and internal auditory meatus. In this study, we establish magnetic resonance imaging (MRI) measurement criteria of the inner ear in Chinese adults.OBJECTIVE: The goal of this study was to provide an anatomic basis for otolosurgery and neurosurgery in Chinese adults.MATERIALS AND METHODS: Sixteen healthy volunteer subjects were scanned by a GE-signa 1.5T MRI scanner. All original images were transferred to an MRI workstation and all the structures of the inner ear were reconstructed, rotated at various angles and measured with an MIP program.RESULTS: Anatomic structures of the membranous labyrinth and internal auditory meatus were well demonstrated in MIP images in all volunteers. All inner ear structures including utricle, saccule, cochlear duct, internal auditory meatus and three semicircular ducts produced high intensity signals.
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| 27. |
- Meng, Yang, et al.
(författare)
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Semi-empirical impedance model of perforated plate under grazing flow
- 2019
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Ingår i: 25th AIAA/CEAS Aeroacoustics Conference, 2019. - Reston, Virginia : American Institute of Aeronautics and Astronautics Inc, AIAA.
-
Konferensbidrag (refereegranskat)abstract
- A semi-empirical impedance formula of a circular orifice under grazing flow is derived, based on a linearized potential flow model. The effect of boundary layer is considered by introducing the convection speed of vorticity which is assumed to be a function of the dimensionless boundary layer thickness. Asymptotic expression of the impedance at low Strouhal number is acquired by the method of perturbation, while the impedance at large Strouhal number can be well approximated by that without grazing flow. The model predictions achieve reasonable agreement with the data available in a previous experimental investigation.
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| 28. |
- Montazeri, Z, et al.
(författare)
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Systematic meta-analyses, field synopsis and global assessment of the evidence of genetic association studies in colorectal cancer
- 2020
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Ingår i: Gut. - : BMJ. - 1468-3288 .- 0017-5749. ; 69:8, s. 1460-1471
-
Tidskriftsartikel (refereegranskat)abstract
- To provide an understanding of the role of common genetic variations in colorectal cancer (CRC) risk, we report an updated field synopsis and comprehensive assessment of evidence to catalogue all genetic markers for CRC (CRCgene2).DesignWe included 869 publications after parallel literature review and extracted data for 1063 polymorphisms in 303 different genes. Meta-analyses were performed for 308 single nucleotide polymorphisms (SNPs) in 158 different genes with at least three independent studies available for analysis. Scottish, Canadian and Spanish data from genome-wide association studies (GWASs) were incorporated for the meta-analyses of 132 SNPs. To assess and classify the credibility of the associations, we applied the Venice criteria and Bayesian False-Discovery Probability (BFDP). Genetic associations classified as ‘positive’ and ‘less-credible positive’ were further validated in three large GWAS consortia conducted in populations of European origin.ResultsWe initially identified 18 independent variants at 16 loci that were classified as ‘positive’ polymorphisms for their highly credible associations with CRC risk and 59 variants at 49 loci that were classified as ‘less-credible positive’ SNPs; 72.2% of the ‘positive’ SNPs were successfully replicated in three large GWASs and the ones that were not replicated were downgraded to ‘less-credible’ positive (reducing the ‘positive’ variants to 14 at 11 loci). For the remaining 231 variants, which were previously reported, our meta-analyses found no evidence to support their associations with CRC risk.ConclusionThe CRCgene2 database provides an updated list of genetic variants related to CRC risk by using harmonised methods to assess their credibility.
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| 29. |
- Petrache, C. M., et al.
(författare)
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Evidence of chiral bands in even-even nuclei
- 2018
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 97:4
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Tidskriftsartikel (refereegranskat)abstract
- Evidence for chiral doublet bands has been observed for the first time in the even-even nucleus Nd136. One chiral band was firmly established. Four other candidates for chiral bands were also identified, which can contribute to the realization of the multiple pairs of chiral doublet bands (MχD) phenomenon. The observed bands are investigated by the constrained and tilted axis cranking covariant density functional theory (TAC-CDFT). Possible configurations have been explored. The experimental energy spectra, angular momenta, and B(M1)/B(E2) values for the assigned configurations are globally reproduced by TAC-CDFT. Calculated results support the chiral interpretation of the observed bands, which correspond to shapes with maximum triaxiality induced by different multiquasiparticle configurations in Nd136.
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| 30. |
- Petrache, C. M., et al.
(författare)
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Multiple chiral bands in 137 Nd
- 2020
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Ingår i: European Physical Journal A. - : Springer Nature. - 1434-6001 .- 1434-601X. ; 56:8
-
Tidskriftsartikel (refereegranskat)abstract
- Two new bands have been identified in 137Nd from a high-statistics JUROGAM II gamma-ray spectroscopy experiment. Constrained density functional theory and particle rotor model calculations are used to assign configurations and investigate the band properties, which are well described and understood. It is demonstrated that these two new bands can be interpreted as chiral partners of previously known three-quasiparticle positive- and negative-parity bands. The newly observed chiral doublet bands in 137Nd represent an important support to the existence of multiple chiral bands in nuclei. The present results constitute the missing stone in the series of Nd nuclei showing multiple chiral bands, which becomes the most extended sequence of odd–even and even-even nuclei presenting multiple chiral bands in the Segré chart.
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| 31. |
- Qian, Li-Bing, et al.
(författare)
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Transmission of electrons through the conical glass capillary with the grounded conducting outer surface
- 2017
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 66:12
-
Tidskriftsartikel (refereegranskat)abstract
- The transmission of 1.5 keV-electrons through a conical glass capillary is reported. This study aims to understand the so-called guiding effect for the negatively charged particles (e.g. electrons). The guiding mechanism is understood quite well with positively charged particles in particular highly charged ions, but not clear with electrons, i. e., even the basic scheme mediated by the existence of negative charge patches to guide the electrons is still somewhat controversial.. The study of the charging-up dynamics causing the electrons transport inside the capillary will shed light on this issue. In order to perform this, a data acquisition system has been setup to follow the time evolution of the two-dimensional angular distribution of the transmitted electrons. The electrons are detected by the multi-channel plate (MCP) detector with a phosphor screen. The image from the phosphor screen is recorded by a charge-coupled device camera. The timing signals for the detected events are extracted from the back stack of the MCP detector and recorded by the data acquisition system, synchronized with the acquired images. The electron beam has a size of 0.5 mm x 0.5 mm and a divergence of less than 0.35.. The inner diameter of the straight part of the capillary is 1.2 mm and the exit diameter is 225 mu m. A small conducting aperture of 0.3 mm in diameter is placed at the entrance of the capillary. Two-dimensional angular distribution of the transmitted electrons through conical glass capillary and its time evolution are measured. The results show that the transmission rate decreases and reaches to a constant value for the completely discharged glass capillary with time going by. The centroid of the angular distribution moves to an asymptotic value while the width remains unchanged. These transmission characteristics are different from those indicated in our previous work (2016 Acta Phys: Si n: 65 204103). The difference originates from the different manipulations of the capillary outer surface. A conducting layer is coated on the outer surface of the capillary and grounded in this work. This isolates various discharge/charge channels and forms a new stable discharge channel. The transmission rate as a function of the tilt angle shows that the allowed transmission occurs at the tilt angle limited by the geometrical factors, i. e., the geometrical opening angle given by the aspect ratio as well as the beam divergence. The transmission characteristics suggest that most likely there are formed no negative patches to facilitate the electron transmission through the glass capillary at this selected beam energy. It is different from that of highly charged ions, where the formation of the charge patches prohibits the close collisions between the following ions and guides them out of the capillary.
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| 32. |
- Qu, Zhiguo, et al.
(författare)
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QB-IMD : A secure medical data processing system with privacy protection based on quantum blockchain for IoMT
- 2024
-
Ingår i: IEEE Internet of Things Journal. - Piscataway, NJ : Institute of Electrical and Electronics Engineers (IEEE). - 2327-4662. ; 11:1, s. 40-49
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Tidskriftsartikel (refereegranskat)abstract
- Security and privacy are issues that cannot be ignored when collecting and processing medical data in the Internet of Medical Things (IoMT). Blockchain technology is a decentralized ledger system that has diverse application scenarios in the medical field. Blockchain technology relies on traditional cryptography to ensure data integrity and verifiability, but the creation of quantum computing has made it possible to break traditional encryption and signature methods. Therefore, quantum blockchain can provide a higher level of security for handling medical data. This paper innovatively designs a new medical data processing system based on quantum blockchain (QB-IMD). In QB-IMD, a quantum blockchain structure and a novel electronic medical record algorithm (QEMR) are proposed to ensure that the processed data is legitimate and tamper-proof. QEMR combines quantum signature and quantum identity authentication to avoid the potential security risks of digital signatures. In addition, through delegated computing by quantum cloud, medical diagnostic data can be computed without leaking to quantum cloud servers, thus protecting user privacy. Through mathematical proof, theoretical analysis and simulation, it is demonstrated that our scheme can resist six attacks and is feasible to protect user privacy. © IEEE
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| 33. |
- Shan, Yuli, et al.
(författare)
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City-level climate change mitigation in China
- 2018
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 4:6
-
Tidskriftsartikel (refereegranskat)abstract
- As national efforts to reduce CO2 emissions intensify, policy-makers need increasingly specific, subnational information about the sources of CO2 and the potential reductions and economic implications of different possible policies. This is particularly true in China, a large and economically diverse country that has rapidly industrialized and urbanized and that has pledged under the Paris Agreement that its emissions will peak by 2030. We present new, city level estimates of CO2 emissions for 182 Chinese cities, decomposed into 17 different fossil fuels, 46 socioeconomic sectors, and 7 industrial processes. We find that more affluent cities have systematically lower emissions per unit of gross domestic product (GDP), supported by imports from less affluent, industrial cities located nearby. In turn, clusters of industrial cities are supported by nearby centers of coal or oil extraction. Whereas policies directly targeting manufacturing and electric power infrastructure would drastically undermine the GDP of industrial cities, consumption based policies might allow emission reductions to be subsidized by those with greater ability to pay. In particular, sector based analysis of each city suggests that technological improvements could be a practical and effective means of reducing emissions while maintaining growth and the current economic structure and energy system. We explore city-level emission reductions under three scenarios of technological progress to show that substantial reductions (up to 31%) are possible by updating a disproportionately small fraction of existing infrastructure.
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| 34. |
- Song, Jiao-Jiao, et al.
(författare)
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Relocalization of uranium 5f electrons in the antiferromagnetic heavy-fermion superconductor UPd2Al3 : Insights from angle-resolved photoemission spectroscopy
- 2024
-
Ingår i: Physical Review B. - : American Physical Society. - 2469-9950 .- 2469-9969. ; 109:20
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the antiferromagnetic heavy fermion superconductor UPd2Al3, employing angle-resolved photoemission spectroscopy to unravel the complex electronic structure of its U 5? electrons. We observe unexpected characteristics that challenge the conventional temperature-dependent behavior of heavy fermion systems, revealing unexpected characteristics. At temperatures above the anticipated coherence temperature (?*), we observe itinerant U 5? electrons at temperatures higher than previously postulated. Additionally, a previously unidentified dispersionless band emerges around 600 meV below the Fermi energy, potentially linked to spin-orbit splitting within the U 5? states. Hybridization between the 5? electrons and conduction band was observed with an energy dispersion of 10 meV at low temperatures, suggesting that U 5? electrons near and at the Fermi surface have an itinerant nature. Temperature-dependent 5?−5? resonance spectra reveal that the 5? electron spectrum weight increases with lowering temperature and begins to decrease at temperatures significantly higher than the Néel temperature (??). We further show that the competition between the Kondo effect and Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions may be responsible for the relocalization of 5? electrons, making relocalization a precursor to the establishment of magnetic order at lower temperatures. Our experiments also provide evidence that 5? electrons with the same orbital are involved in both the Kondo effect and RKKY interactions, suggesting that the two coexist at lower temperatures.
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| 35. |
- Thomson, Mark D., et al.
(författare)
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Relativistic Doppler reflection as a probe for the initial relaxation of a non-equilibrium electron-hole plasma in silicon
- 2015
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Ingår i: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19). - : Institute of Physics (IOP). ; , s. 012016-012019
-
Konferensbidrag (refereegranskat)abstract
- This paper reviews the status of investigations of the relativistic Doppler reflectionof a broadband terahertz pulse at a counter-propagating plasma front of photo-excited chargecarriers in undoped silicon. When a THz pulse with 20-THz bandwidth impinges onto amoving plasma front with a carrier density in the range of 1019 per cm3, one observes a spectralup-shift, which is, however, much less pronounced than expected from simulations assuming a Drude plasma characterized by a single carrier relaxation time τ of the order of 15-100 fs.Qualitative agreement between simulations and experiments can be achieved if τ is chosen tobe less than 5 fs. In order to explore carrier relaxation in more detail, optical-pump/THz-probeexperiments in the conventional co-propagation geometry were performed. If the pump-probedelay is long enough for monitoring of the equilibrium value of the scattering time, τ rangesfrom 200 fs at low carrier density to 20 fs in the 1019-cm-3 density range. For small (subpicosecond)pump-probe delay, the data reveal a significantly faster scattering, which slowsdown during energy relaxation of the charge carriers.
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| 36. |
- Wan, Cheng-Liang, et al.
(författare)
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Dynamics of slow electrons transmitting through straight glass capillary and tapered glass capillary
- 2016
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Ingår i: Wuli xuebao. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 65:20
-
Tidskriftsartikel (refereegranskat)abstract
- It has been found that the transmission rate of the electrons through insulating capillaries as a function of time/incident charge is not the same as that of the ions. The question arises that by using the electrons, if the negative charge patches can be formed to facilitate the transmission of the following electrons, thereby substantiating that the so-called guiding effect works also for electrons. This study aims to observe the time evolutions of the transmission of electrons through a straight glass tube and a tapered glass capillary. This will reveal the details of how and (or) if the negative charge patches can be formed when the electrons transport through them. In this work, a set of MCP/phosphor two-dimensional detection system based on Labview platform is developed to obtain the time evolution of the angular distribution of the transmitted electrons. The pulsed electron beams are obtained to test our detection system. The time evolution of the angular profile of 1.5 keV electrons transmitting through the glass tube/capillary is observed. The transmitted electrons are observed on the detector for a very short time and disappear for a time and then appear again for both the glass tube and tapered glass capillary, leading to an oscillation. The positive charge patches are formed in the insulating glass tube and tapered glass capillary since the secondary electron emission coefficient for the incident energy is larger than 1. It is due to the fact that fast discharge of the deposited charge leads to the increase of the transmission rate, while the fast blocking of the incident electrons due to the deposited positive charge leads to the decrease of the transmission rate. The geometrical configuration of the taper glass capillary tends to make the secondary electrons deposited at the exit part to form the negative patches that facilitate the transmission of electrons. This suggests that if the stable transmission needs to be reached for producing the electron micro-beam by using tapered glass capillaries, the steps must be taken to have the proper grounding and shielding of the glass capillaries and tubes. Our results show a difference in transmission through the insulating capillary between electrons and highly charged ions.
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| 37. |
- Wang, Yaxuan, et al.
(författare)
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Sustainable polysaccharide-based materials for intelligent packaging
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 313
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Forskningsöversikt (refereegranskat)abstract
- Unlike traditional food packaging which is mainly used to enhance food quality and provide consumers with product descriptions, intelligent packaging, as a novel type of food packaging system, is capable of executing intelligent functions and has attracted much attention during the past decade. Considering the inherent advantages of polysaccharides such as excellent biocompatibility, biodegradability, non-toxicity, and high abundance, intelligent packaging materials based on such polymers are believed to be one of the most promising candidates among current intelligent food packing systems. This work summarizes the latest research on the development, properties and applications of natural polysaccharide-based intelligent food packaging materials. Moreover, this paper shows that polysaccharides have a good application prospect in the intelligent packaging industry. First, the intelligent packaging system and polysaccharide-based intelligent packaging are summarized, and several representative polysaccharides are introduced. Second, various sensing methods for monitoring changes in food properties are summarized, including those based on variation in temperature, humidity, oxygen levels, pH, chemical composition, or microbial contamination. Then, the application of polysaccharide-based intelligent packaging materials in the food industry is discussed. Finally, the difficulties and future directions of polysaccharide-based materials for intelligent food packaging are discussed.
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| 38. |
- Wang, Zhixin, et al.
(författare)
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Large area photonic crystal quantum cascade laser with 5 W surface-emitting power
- 2019
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Ingår i: Optics Express. - : OPTICAL SOC AMER. - 1094-4087. ; 27:16, s. 22708-22716
-
Tidskriftsartikel (refereegranskat)abstract
- Room temperature surface emission is realized on a large area (1.5 mm x 1.5 mm) photonic crystal quantum cascade laser (PhC-QCL) driven under pulsed mode, at the wavelength around 8.75 mu m. By introducing in-plane asymmetry to the pillar shape and optimizing the current injection with a grid-like window contact, the maximum peak power of the PhC-QCL is up to 5 W. The surface emitting beam has a crossing shape with 10 degrees divergence.
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| 39. |
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| 40. |
- Xiong, Shaobing, et al.
(författare)
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Engineering of the Back Contact between PCBM and Metal Electrode for Planar Perovskite Solar Cells with Enhanced Efficiency and Stability
- 2019
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 7:19
-
Tidskriftsartikel (refereegranskat)abstract
- The cathode interface plays a critical role in achieving high-performance fullerene/perovskite planar solar cells. Herein, the simple molecule Isatin and its derivatives are introduced at the back contact [6,6]-phenyl-C61-butyric acid methyl ester (PCBM)/Al as a cathode modification interlayer. It is revealed that the Isatin interlayers facilitate electron transport/extraction and suppress electron recombination, attributed to the formation of negative dipole potential steps and the passivation of the interfacial trap density. The average power conversion efficiencies of the resulting devices are significantly improved by 11% from 17.68% to 19.74%, with an enhancement in all device parameters including short-circuit current, open-circuit voltage, and fill factor. The hysteresis index is found to disappear. In addition, such interlayer enhances device stability under ambient conditions compared to the control devices due to suppression of moisture-induced degradation of the perovskite films. These findings provide a comprehensive understanding of the engineering of the back contact between PCBM and the metal electrode to improve efficiency and stability of perovskite solar cells.
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| 41. |
- Xu, Xiaohang, et al.
(författare)
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The local impact of a coal-fired power plant on inorganic mercury and methyl-mercury distribution in rice (Oryza sativa L.)
- 2017
-
Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491 .- 1873-6424. ; 223, s. 11-18
-
Tidskriftsartikel (refereegranskat)abstract
- Emission from coal-fired power plants is one of the major anthropogenic sources of mercury (Hg) in the environment, because emitted Hg can be quickly deposited nearby the source, attention is paid to the effects of coal-burning facilities on levels of toxic methyl-mercury (MeHg) in biota near such sources. Since rice is an agricultural crop that can bio-accumulate MeHg, the potential effects of a large Hg emitting coal-fired power plant in Hunan Province, China on both inorganic Hg (Hg(II)) and MeHg distributions in rice was investigated. Relatively high MeHg (up to 3.8 mu g kg(-1)) and Hg(II) (up to 22 mu g kg(-1)) concentrations were observed in rice samples collected adjacent to the plant, suggesting a potential impact of Hg emission from the coal fired power plant on the accumulation of Hg in rice in the area. Concentrations of MeHg in rice were positively correlated with soil MeHg, soil S, and gaseous elemental Hg (GEM) in ambient air. Soil MeHg was the most important factor controlling MeHg concentrations in rice. The methylation of Hg in soils may be controlled by factors such as the chemical speciation of inorganic Hg, soil S, and ambient GEM.
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| 42. |
- Yang, Zhenxing, et al.
(författare)
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Tuning the band gap and the nitrogen content in carbon nitride materials by high temperature treatment at high pressure
- 2018
-
Ingår i: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 130, s. 170-177
-
Tidskriftsartikel (refereegranskat)abstract
- Carbon nitride (C-N) materials have been attracting great interest because of their extraordinary performance in photocatalysis and energy conversion. However, developing an effective strategy for achieving band-gap engineering of C-N materials to satisfy practical applications remains highly desired. Here we report an efficient way to tune the band gap and control the nitrogen stoichiometry in carbon nitride compounds by using high pressure and high temperature (HPHT) treatment. It is found that treating a g-C3N4 precursor at relatively low temperature (630oC and below) under pressure can efficiently narrow the band gap even down to the red light region (~600 nm), increase the crystallinity, and significantly improve the charge carrier separation efficiency (by two orders of magnitude), almost without changing their stoichiometry. When increasing the treatment temperature under pressure, nitrogen-doped graphene/graphite materials with weak ferromagnetism were obtained. We thus obtained C-N materials with tunable band gaps, ranging from semiconducting to metallic states. XPS measurements show that pyridinic nitrogen is preferentially eliminated under such HPHT conditions while graphitic nitrogen is preserved in the C-N network. Our results thus provide an efficient strategy for tuning the structure and physical properties of C-N materials for applications.
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| 43. |
- Yao, Xiangyu, et al.
(författare)
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A highly sensitive bead-based flow cytometric competitive binding assay to detect SARS-CoV-2 neutralizing antibody activity
- 2022
-
Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Accurate detection of SARS-CoV-2 neutralizing antibody (nAb) is critical for assessing the immunity levels after virus infection or vaccination. As fast, cost-effective alternatives to viral infection-based assays, competitive binding (CB) assays were developed to quantitate nAb by monitoring the ability of sera to inhibit the binding of viral spike (S) protein to the angiotensin converting enzyme 2 (ACE2) receptor. Herein, we established a bead-based flow cytometric CB assay and tested the detection performance of six combination models, i.e. immobilized ACE2 and soluble Fc-tagged S1 subunit of S protein (iACE2/S1-Fc), immobilized ACE2 and soluble Fc-tagged receptor binding domain (RBD) of S protein (iACE2/RBD-Fc), immobilized S1 and soluble Fc-tagged ACE2 (iS1/ACE2-Fc), immobilized S1 and soluble His-tagged ACE2 (iS1/ACE2-His), immobilized RBD and soluble Fc-tagged ACE2 (iRBD/ACE2-Fc), and immobilized RBD and soluble His-tagged ACE2 (iRBD/ACE2-His). Using SARS-CoV-2 monoclonal antibodies and sera of convalescent COVID-19 patients and vaccinated subjects, the combination models iACE2/RBD-Fc, iACE2/S1-Fc and iS1/ACE2-His were identified to be able to specifically detect SARS-CoV-2 nAb, among which iACE2/RBD-Fc model showed the highest sensitivity, superior to a commercial SARS-CoV-2 surrogate virus neutralization test (sVNT) ELISA kit. Further studies demonstrated that the sensitivity and specificity of CB assays were affected by the tag of ACE2, type of spike and method of measuring binding rate between ACE2 and spike. Moreover, the iACE2/RBD-Fc model showed good performance in detecting kinetic development of nAb against both the prototype SARS-CoV-2 strain and an omicron variant of SARS-CoV-2 in people immunized by an inactivated SARS-CoV-2 vaccine, and the results of iACE2/RBD-Fc model are correlated well with those of live virus-based and pseudovirus-based neutralization tests, demonstrating the potential to be developed into a highly sensitive, specific, versatile and high-throughput method for detecting SARS-CoV-2 nAb in clinical practice.
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| 44. |
- Yao, Yunjun, et al.
(författare)
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Assessment and simulation of global terrestrial latent heat flux by synthesis of CMIP5 climate models and surface eddy covariance observations
- 2016
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 0168-1923. ; 223, s. 151-167
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Tidskriftsartikel (refereegranskat)abstract
- The latent heat flux (LE) between the terrestrial biosphere and atmosphere is a major driver of the global hydrological cycle. In this study, we evaluated LE simulations by 45 general circulation models (GCMs) in the Coupled Model Intercomparison Project Phase 5 (CMIP5) by a comparison with eddy covariance (EC) observations from 240 globally distributed sites from 2000 to 2009. In addition, we improved global terrestrial LE estimates for different land cover types by synthesis of seven best CMIP5 models and EC observations based on a Bayesian model averaging (BMA) method. The comparison results showed substantial differences in monthly LE among all GCMs. The model CESM1-CAM5 has the best performance with the highest predictive skill and a Taylor skill score (S) from 0.51-0.75 for different land cover types. The cross-validation results illustrate that the BMA method has improved the accuracy of the CMIP5 GCM's LE simulation with a decrease in the averaged root-mean-square error (RMSE) by more than 3 W/m2 when compared to the simple model averaging (SMA) method and individual GCMs. We found an increasing trend in the BMA-based global terrestrial LE (slope of 0.018 W/m2 yr-1, p <0.05) during the period 1970-2005. This variation may be attributed directly to the inter-annual variations in air temperature (Ta), surface incident solar radiation (Rs) and precipitation (P). However, our study highlights a large difference from previous studies in a continuous increasing trend after 1998, which may be caused by the combined effects of the variations of Rs, Ta, and P on LE for different models on these time scales. This study provides corrected-modeling evidence for an accelerated global water cycle with climate change.
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| 45. |
- Zhang, Linyu, et al.
(författare)
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miR-125b promotes tau phosphorylation by targeting the neural cell adhesion molecule in neuropathological progression
- 2019
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Ingår i: Neurobiology of Aging. - : ELSEVIER SCIENCE INC. - 0197-4580 .- 1558-1497. ; 73, s. 41-49
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs, small noncoding RNAs, not only regulate gene expression at the post-transcriptional level in a variety of physiological processes but also accompany the initiation and progression of a vast number of diseases, including dementia. While miR-125b has been shown to be aberrantly expressed in some dementia patients, its role in the pathological process remains ambiguous. Presenilin-1/2 conditional double knockout mice exhibit a range of symptoms, including impaired cognition and memory, increased tau phosphorylation, neuroinflammation, and apoptosis, and are therefore regarded as a useful dementia model. In the prefrontal cortices of double knockout mice, miR-125b was found to be abnormally increased in an age-dependent manner. We further verified the neural cell adhesion molecule (NCAM) as an miR-125b target using the dual luciferase reporter assay. The NCAM protein level was decreased when miR-125b was overexpressed (OE) in neuronal growth factor-induced differentiated PC12 cells, which further inhibited the neuronal growth factor-induced phosphorylation of glycogen synthase kinase 3 beta (GSK beta) at the Ser9 site and ultimately increased the GSK3 beta activity and tau phosphorylation. Moreover, on serum deprivation, high GSK3 beta activity in differentiated miR-125b-OE PC12 cells induced increased caspase-3 activation. Finally, adeno-associated virus-mediated miR-125b overexpression in the prefrontal cortexes of wild-type C57B/L6 mice resulted in decreased dendritic spine density. In addition, similar to the in vitro data, elevated GSK3 beta activity and hyperphosphorylation of the tau protein were confirmed. Taken together, our findings reveal a direct regulation of miR-125b on NCAM, which leads to further effects on downstream GSK3 beta activity and tau phosphorylation and may contribute to the generation of neurofibrillary tangles in neuropathological progression.
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| 46. |
- Zhang, Meizhen, et al.
(författare)
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Fabrication and Application of Ag@SiO2/Au Core-Shell SERS Composite in Detecting Cu2+ in Water Environment
- 2024
-
Ingår i: Molecules. - 1431-5157 .- 1420-3049. ; 29:7
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Tidskriftsartikel (refereegranskat)abstract
- A sensitive and simple method for detecting Cu2+ in the water source was proposed by using surface-enhanced Raman scattering spectroscopy (SERS) based on the Ag@SiO2/Au core-shell composite. The Ag@SiO2 SERS tag was synthesized by a simple approach, in which Ag nanoparticles were first embedded with Raman reporter PATP and next coated with a SiO2 shell. The Ag@SiO2 nanoparticles had strong stability even in a high-concentration salty solution, and there were no changes to their properties and appearance within one month. The Ag@SiO2/Au composite was fabricated through a controllable self-assemble process. L-cysteine was decorated on the surface of a functionalized Ag@SiO2/Au composite, as the amino and carboxyl groups of it can form coordinate covalent bond with Cu2+, which shows that the Ag@SiO2/Au composite labelled with L-cysteine has excellent performance for the detection of Cu2+ in aqueous media. In this study, the SERS detection of Cu2+ was carried out using Ag@SiO2 nanoparticles, and the limit of detection (LOD) as low as 0.1 mg/L was achieved.
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| 47. |
- Zhang, Qingke, et al.
(författare)
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Vector coevolving particle swarm optimization algorithm
- 2017
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Ingår i: Information Sciences. - : Elsevier. - 0020-0255 .- 1872-6291. ; 394-395, s. 273-298
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we propose a novel vector coevolving particle swarm optimization algorithm (VCPSO). In VCPSO, the full dimension of each particle is first randomly partitioned into several sub-dimensions. Then, we randomly assign either one of our newly designed scalar operators or learning operators to update the values in each sub-dimension. The scalar operators are designed to enhance the population diversity and avoid premature convergence. In addition, the learning operators are designed to enhance the global and local search ability. The proposed algorithm is compared with several other classical swarm optimizers on thirty-three benchmark functions. Comprehensive experimental results show that VCPSO displays a better or comparable performance compared to the other algorithms in terms of solution accuracy and statistical results.
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