| 1. |
- Wan, Lu Ming, et al.
(författare)
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Heparanase Facilitates PMA-Induced Megakaryocytic Differentiation in K562 Cells via Interleukin 6/STAT3 Pathway
- 2020
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Ingår i: Thrombosis and Haemostasis. - : GEORG THIEME VERLAG KG. - 0340-6245 .- 2567-689X. ; 120:4, s. 647-657
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Tidskriftsartikel (refereegranskat)abstract
- Heparanase (HPSE) is an endo-beta-D-glucuronidase that cleaves heparan sulfate and hence participates in remodeling of the extracellular matrix, leading to release of cytokines that are immobilized by binding to heparan sulfate proteoglycans (HSPGs), and consequently activating signaling pathways. This function of HPSE is correlated to its expression level that is normally very low in majority of the tissues. Exceptionally, human platelets express high level of HPSE, suggesting a unique physiological role in this cell. Using K562 cell line, we found a progressive increase of HPSE during the megakaryocytic differentiation. Analysis of a series of megakaryocytic differentiation-related heparin-binding proteins (HBPs) in the cell culture medium revealed an exclusive positive correlation between the level of interleukin 6 (IL-6) and HPSE expression. IL-6 modulated megakaryocytic differentiation through activation of STAT3. Further, we demonstrated that overexpression of HPSE potentiates megakaryocytic differentiation, whereas elimination of HPSE led to a delayed differentiation. This function of HPSE is associated with its activity, as overexpression of inactive HPSE had no effect on IL-6 production and megakaryocytic differentiation. The role of HPSE is further supported by the observation in an umbilical cord blood CD34+ cells megakaryocytic differentiation model. Our data propose a novel role for HPSE in platelets production by a HPSE/IL-6/STAT3 positive feedback loop that specifically regulates megakaryocytes maturation.
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| 2. |
- Wan, Qiuchi, et al.
(författare)
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Evaluating quantitative pollen representation of vegetation in the tropics : A case study on the Hainan Island, tropical China
- 2020
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Ingår i: Ecological Indicators. - : Elsevier. - 1470-160X .- 1872-7034. ; 114, s. 1-14
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Tidskriftsartikel (refereegranskat)abstract
- Complex pollen-vegetation relationships in tropical environments have long been a challenge for the interpretation of pollen spectra in terms of vegetation cover. Here, we test the application of the widely-used Extended R-Value (ERV) model in the tropical secondary and planted woodlands of the Hainan Island (China) to estimate relative pollen productivities (RPPs) for common plant taxa occurring as pollen in surface and fossil samples of the region. We collected pollen (soil samples) and related vegetation data within 1500 m radius at 23 random distributed sites within an area of 50 km x 100 km. We found a large difference between the modern pollen assemblages and the related vegetation composition in terms of number and dominance of taxa. We tested the three existing ERV sub-models and three methods to distance-weight vegetation cover, i.e. 1/d, the Prentice's model (using a Gaussian Plume dispersal model, GPM), and the Lagrangian stochastic dispersal model (LSM). The LSM appears to be inappropriate for our dataset. The combination of ERV sub-model 2 and Prentice's model using nine anemophilous and zoophilous (or with "messy" pollination syndrome) taxa was found to provide the best results. The relevant source area of pollen (RSAP) of the soil samples was estimated to ca. 1000-1500 m. The ranking of RPPs is as follows: Castanopsis-Lithocarpus (19.44 +/- 0.17) Asteraceae (8.74 +/- 0.05) > Moraceae (6.52 +/- 0.08) > Euphorbiaceae (5.22 +/- 0.1) > Papilionaceae (2.66 +/- 0.05) > Mallotus-Macaranga (2.21 +/- 0.08) > Anacardiaceae (1.77 +/- 0.04) > Rubiaceae (1.29 +/- 0.02) > Poaceae (=1). Violation of the ERV model assumptions of anemophily and stationarity of vegetation composition influenced the performance of the ERV analysis in this study and implied careful evaluation of the results. Nevertheless, the obtained RPPs are considered reliable and will allow to quantify the relative cover of the nine plant taxa in the past. Further studies of this kind will be worthwhile to obtain additional RPP values for a larger number of tropical taxa, even though quantification of past plant cover in the tropics will remain a challenge. The numerous zoophilous taxa may either be absent of the pollen record, or exhibit pollen-vegetation relationships for which the ERV-model is not successful in estimating RPPs. These plant taxa will require other approaches for their quantification in the past.
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| 3. |
- Zhang, Zhuo-Zhi, et al.
(författare)
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A suspended silicon single-hole transistor as an extremely scaled gigahertz nanoelectromechanical beam resonator
- 2020
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 32:52
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Tidskriftsartikel (refereegranskat)abstract
- Suspended single-hole transistors (SHTs) can also serve as nanoelectromechanical resonators, providing an ideal platform for investigating interactions between mechanical vibrations and charge carriers. Demonstrating such a device in silicon (Si) is of particular interest, due to the strong piezoresistive effect of Si and potential applications in Si-based quantum computation. Here, a suspended Si SHT also acting as a nanoelectromechanical beam resonator is demonstrated. The resonant frequency and zero-point motion of the device are approximate to 3 GHz and 0.2 pm, respectively, reaching the best level among similar devices demonstrated with Si-containing materials. The mechanical vibration is transduced to electrical readout by the SHT. The signal transduction mechanism is dominated by the piezoresistive effect. A giant apparent effective piezoresistive gauge factor with strong correlation to single-hole tunneling is extracted in this device. The results show the great potential of the device in interfacing charge carriers with mechanical vibrations, as well as investigating potential quantum behavior of the vibration phonon mode.
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| 4. |
- Bai, Fan, et al.
(författare)
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Application of similarity theory in modeling the output characteristics of proton exchange membrane fuel cell
- 2021
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Ingår i: International journal of hydrogen energy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0360-3199 .- 1879-3487. ; 46:74, s. 36940-36953
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Tidskriftsartikel (refereegranskat)abstract
- Proton Exchange Membrane Fuel Cell (PEMFC) has attracted widespread interest. In the present work, similarity analysis is adopted for a three-dimensional single-phase isothermal model of PEMFC to derive similarity criteria. Seven kinds of input criteria (Pi(1) similar to Pi(7)) are obtained, relevant to the fluid flow, pressure drop, flow resistance in a porous medium, activity loss, diffusion mass transfer, convective mass transfer and ohmic loss in PEMFC respectively. Dimensionless voltage and dimensionless current density are defined as two output criteria. Numerical verifications show that if the seven criteria keep their individual values with their components vary in a wide range, the dimensionless polarization curves keep the same with a deviation about 1%, showing the validity and feasibility of the present analysis. From the effect on the dimensionless polarization curve, sensibility analysis shows that the seven criteria can be divided into three categories: strong (Pi(4) and Pi(7), -94.9% similar to +349.2%), mild to minor (Pi(5) and Pi(6), -4.5% similar to +5.0%), and negligible (Pi(1), Pi(2) and Pi(3), -1.2% similar to +1.1%). The similarity analysis approach can greatly save computation time in modeling the output characteristics of PEMFC. (C) 2021 Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC.
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| 5. |
- Eriksson, Kimmo, et al.
(författare)
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Perceptions of the appropriate response to norm violation in 57 societies
- 2021
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Ingår i: Nature Communications. - : Nature Research. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Norm enforcement may be important for resolving conflicts and promoting cooperation. However, little is known about how preferred responses to norm violations vary across cultures and across domains. In a preregistered study of 57 countries (using convenience samples of 22,863 students and non-students), we measured perceptions of the appropriateness of various responses to a violation of a cooperative norm and to atypical social behaviors. Our findings highlight both cultural universals and cultural variation. We find a universal negative relation between appropriateness ratings of norm violations and appropriateness ratings of responses in the form of confrontation, social ostracism and gossip. Moreover, we find the country variation in the appropriateness of sanctions to be consistent across different norm violations but not across different sanctions. Specifically, in those countries where use of physical confrontation and social ostracism is rated as less appropriate, gossip is rated as more appropriate. Little is known about peoples preferred responses to norm violations across countries. Here, in a study of 57 countries, the authors highlight cultural similarities and differences in peoples perception of the appropriateness of norm violations.
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| 6. |
- Li, F., et al.
(författare)
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A Cobalt@Cucurbit[5]uril Complex as a Highly Efficient Supramolecular Catalyst for Electrochemical and Photoelectrochemical Water Splitting
- 2021
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Ingår i: Angewandte Chemie International Edition. - : Wiley-VCH Verlag. - 1433-7851 .- 1521-3773. ; 60:4, s. 1976-1985
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Tidskriftsartikel (refereegranskat)abstract
- A host–guest complex self-assembled through Co2+ and cucurbit[5]uril (Co@CB[5]) is used as a supramolecular catalyst on the surface of metal oxides including porous indium tin oxide (ITO) and porous BiVO4 for efficient electrochemical and photoelectrochemical water oxidation. When immobilized on ITO, Co@CB[5] exhibited a turnover frequency (TOF) of 9.9 s−1 at overpotential η=550 mV in a pH 9.2 borate buffer. Meanwhile, when Co@CB[5] complex was immobilized onto the surface of BiVO4 semiconductor, the assembled Co@CB[5]/BiVO4 photoanode exhibited a low onset potential of 0.15 V (vs. RHE) and a high photocurrent of 4.8 mA cm−2 at 1.23 V (vs. RHE) under 100 mW cm−2 (AM 1.5) light illumination. Kinetic studies confirmed that Co@CB[5] acts as a supramolecular water oxidation catalyst, and can effectively accelerate interfacial charge transfer between BiVO4 and electrolyte. Surface charge recombination of BiVO4 can be also significantly suppressed by Co@CB[5].
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| 7. |
- Liang, Hua, et al.
(författare)
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Recognition of maturity-onset diabetes of the young in China
- 2021
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Ingår i: Journal of Diabetes Investigation. - : Wiley. - 2040-1116 .- 2040-1124. ; 12:4, s. 501-509
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Tidskriftsartikel (refereegranskat)abstract
- Aims/Introduction: Given that mutations related to maturity-onset diabetes of the young (MODY) are rarely found in Chinese populations, we aim to characterize the mutation spectrum of MODY pedigrees. Materials and Methods: Maturity-onset diabetes of the young candidate gene- or exome-targeted capture sequencing was carried out in 76 probands from unrelated families fulfilling the clinical diagnostic criteria for MODY. MAF <0.01 in the GnomAD or ExAC database was used to filter significant variants. Sanger sequencing was then carried out to validate findings. Function prediction by SIFT, PolyPhen-2 and PROVEAN or CADD was carried out in missense mutations. Results: A total of 32 mutations in six genes were identified in 31 families, accounting for 40.79% of the potential MODY families. The MODY subtype detection rate was 18.42% for GCK, 15.79% for HNF1A, 2.63% for HNF4A, and 1.32% for KLF11, PAX4 and NEUROG3. Seven nonsense/frameshift mutations and four missense mutations with damaging prediction were newly identified novel mutations. The clinical features of MODY2, MODY3/1 and MODYX are similar to previous reports. Clinical phenotype of NEUROG3 p.Arg55Glufs*23 is characterized by hyperglycemia and mild intermittent abdominal pain. Conclusions: This study adds to the emerging pattern of MODY epidemiology that the proportion of MODY explained by known pathogenic genes is higher than that previously reported, and found NEUROG3 as a new causative gene for MODY.
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| 8. |
- Ma, Wenjun, et al.
(författare)
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Responses of soil extracellular enzyme activities and microbial community properties to interaction between nitrogen addition and increased precipitation in a semi-arid grassland ecosystem
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 703
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Tidskriftsartikel (refereegranskat)abstract
- Both atmospheric nitrogen (N) deposition and precipitation can strongly impact below-ground biogeochemical processes. Soil extracellular enzymes activities (EEAs) and microorganisms are considered as the key agents in ecosystem nutrient cycling. However, how the interaction between increasing N deposition and precipitation may affect soil EEAs and microbes remain poorly understood. In a 5-year field experiment in a meadow steppe in northern China, we tested the effects of N addition (N0, 0; N1, 5; N2, 10 g N m−2 yr−1) and increased precipitation (W0, ambient precipitation; W1, increase of 15% ambient precipitation; W2, increase of 30% ambient precipitation) on soil EEAs, microbial and chemical properties. Results showed that their interaction significantly affected all hydrolase activities, except for β-1,4-xylosidase (βX). Furthermore, increased precipitation and N addition interactively affected bacterial gene copies (P ≤ 0.05), and increased precipitation comparatively had a stronger effects. The results on the combination of N addition and increased precipitation showed that increased precipitation alleviated the positive effects of N addition on soil EEAs. This implies that the effects of either treatment alone on grassland biogeochemical processes may be alleviated by their simultaneous occurrence. Our results suggested that soil EEAs were mainly controlled by the content of N and phosphorus (P), and the ratio of C: N and C: P. Therefore, soil element content and stoichiometry could better explain the responses of EEAs to global changes. Moreover, soil microbial communities were mainly controlled by soil P content. Overall, our study highlights that the interaction between N deposition and precipitation may play a vital role in predicting the responses of soil enzyme activities to global changes in grassland ecosystems.
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| 9. |
- Wang, Deyu, et al.
(författare)
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Mapping the BCPNN Learning Rule to a Memristor Model
- 2021
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media SA. - 1662-4548 .- 1662-453X. ; 15
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Tidskriftsartikel (refereegranskat)abstract
- The Bayesian Confidence Propagation Neural Network (BCPNN) has been implemented in a way that allows mapping to neural and synaptic processes in the human cortexandhas been used extensively in detailed spiking models of cortical associative memory function and recently also for machine learning applications. In conventional digital implementations of BCPNN, the von Neumann bottleneck is a major challenge with synaptic storage and access to it as the dominant cost. The memristor is a non-volatile device ideal for artificial synapses that fuses computation and storage and thus fundamentally overcomes the von Neumann bottleneck. While the implementation of other neural networks like Spiking Neural Network (SNN) and even Convolutional Neural Network (CNN) on memristor has been studied, the implementation of BCPNN has not. In this paper, the BCPNN learning rule is mapped to a memristor model and implemented with a memristor-based architecture. The implementation of the BCPNN learning rule is a mixed-signal design with the main computation and storage happening in the analog domain. In particular, the nonlinear dopant drift phenomenon of the memristor is exploited to simulate the exponential decay of the synaptic state variables in the BCPNN learning rule. The consistency between the memristor-based solution and the BCPNN learning rule is simulated and verified in Matlab, with a correlation coefficient as high as 0.99. The analog circuit is designed and implemented in the SPICE simulation environment, demonstrating a good emulation effect for the BCPNN learning rule with a correlation coefficient as high as 0.98. This work focuses on demonstrating the feasibility of mapping the BCPNN learning rule to in-circuit computation in memristor. The feasibility of the memristor-based implementation is evaluated and validated in the paper, to pave the way for a more efficient BCPNN implementation, toward a real-time brain emulation engine.
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| 10. |
- Xu, Jiawei, et al.
(författare)
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A Memristor Model with Concise Window Function for Spiking Brain-Inspired Computation
- 2021
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Ingår i: 3rd IEEE International Conference on Artificial Intelligence Circuits and Systems, AICAS. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a concise window function to build a memristor model, simulating the widely-observed non-linear dopant drift phenomenon of the memristor. Exploiting the non-linearity, the memristor model is applied to the in-situ neuromorphic solution for a cortex-inspired spiking neural network (SNN), spike-based Bayesian Confidence Propagation Neural Network (BCPNN). The improved memristor model utilizing the proposed window function is able to retain the boundary effect and resolve the boundary lock and inflexibility problem, while it is simple in form that can facilitate large-scale neuromorphic model simulation. Compared with the state-of-the-art general memristor model, the proposed memristor model can achieve a 5.8x reduction of simulation time at a competitive fitting level in cortex-comparable large-scale software simulation. The evaluation results show an explicit similarity between the non-linear dopant drift phenomenon of the memristor and the BCPNN learning rule, and the memristor model is able to emulate the key traces of BCPNN with a correlation coefficient over 0.99.
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