| 351. |
- Li, Yuchen, et al.
(författare)
-
Public awareness, emotional reactions and human mobility in response to the COVID-19 outbreak in China : a population-based ecological study
- 2022
-
Ingår i: Psychological Medicine. - : Cambridge University Press. - 0033-2917 .- 1469-8978. ; 52:9, s. 1793-1800
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The outbreak of COVID-19 generated severe emotional reactions, and restricted mobility was a crucial measure to reduce the spread of the virus. This study describes the changes in public emotional reactions and mobility patterns in the Chinese population during the COVID-19 outbreak.Methods: We collected data on public emotional reactions in response to the outbreak through Weibo, the Chinese Twitter, between January 1st and March 31st, 2020. Using anonymized location-tracking information, we analyzed the daily mobility patterns of approximately 90% of Sichuan residents.Results: There were three distinct phases of the emotional and behavioral reactions to the COVID-19 outbreak. The alarm phase (January 19th –26th) was a restriction-free period, characterized by few new daily cases, but enormous public negative emotions (the number of negative comments per Weibo post increased by 246.9 per day, 95%CI: 122.5–371.3), and a substantial increase in self-limiting mobility (from 45.6% to 54.5%, changing by 1.5% per day, 95%CI: 0.7%–2.3%). The epidemic phase (January 27th –February 15th) exhibited rapidly increasing numbers of new daily cases, decreasing expression of negative emotions (a decrease of 27.3 negative comments per post per day, 95%CI: −40.4–−14.2), and a stabilized level of self-limiting mobility. The relief phase (February 16th –March 31st) had a steady decline in new daily cases and decreasing levels of negative emotion and self-limiting mobility.Conclusions: During the COVID-19 outbreak in China, the public’s emotional reaction was strongest before the actual peak of the outbreak and declined thereafter. The change in human mobility patterns occurred before the implementation of restriction orders, suggesting a possible link between emotion and behavior.
|
|
| 352. |
- Liang, L., et al.
(författare)
-
Theoretical study on the interaction of nucleotides on two-dimensional atomically thin graphene and molybdenum disulfide
- 2017
-
Ingår i: FlatChem. - : Elsevier B.V.. - 2452-2627. ; 2, s. 8-14
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, the interaction between single nucleotide and polynucleotides composed of different nucleotides and two-dimensional (2D) materials (graphene and MoS2) were investigated through first principles calculations and molecular dynamics (MD) simulation. The binding energy strength between single nucleotide and graphene is G > C > A > T, and it is G > A > C > T between single nucleotide and MoS2, derived from density function density (DFT) calculations. The binding strength between polynucleotide and graphene is A6 > G6 > T6 > C6, and the order is G6 > A6 > C6 > T6 of binding strength between polynucleotide and MoS2, calculated from molecular dynamics simulation. The average binding free energy for different single nucleotide A, T, C, G (polynucleotides A6, T6, C6, G6) on graphene sheet is −4.17 kcal/mol (-10.04 kcal/mol), and it is about −2.29 kcal/mol (-2.24 kcal/mol) on MoS2 surface. The binding strength for different single nucleotide (polynucleotides) on graphene sheets is around 2 times (4 times) stronger than that between nucleotide (polynucleotides) and MoS2 surface. The different absorption strength of nucleotides on these two-dimensional materials may be utilized for different promising applications.
|
|
| 353. |
- Lind, Lars, et al.
(författare)
-
Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
- 2021
-
Ingår i: eLife. - : eLife Sciences Publications Ltd. - 2050-084X. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions.
|
|
| 354. |
- Liu, Jian, et al.
(författare)
-
Quantitative proteomics approach reveals novel biomarkers and pathological mechanism of keloid
- 2022
-
Ingår i: PROTEOMICS - Clinical Applications. - : John Wiley & Sons. - 1862-8346 .- 1862-8354. ; 16:4
-
Tidskriftsartikel (refereegranskat)abstract
- Background Keloid is a pathological skin scar formation with complex and unclear molecular pathology mechanism. Novel biomarkers and associated mechanisms are needed to improve current therapies.Objectives To identify novel biomarkers and underlying pathological mechanisms of keloids.MethodsSix pairs of keloid scar tissues and corresponding normal skin tissues were quantitatively analyzed by a high-resolution label-free mass spectrometry-based proteomics approach. Differential protein expression data was further analyzed by a comprehensive bioinformatics approach to identify novel biomarkers and mechanistic pathways for keloid formation. Candidate biomarkers were validated experimentally.Results In total, 1359 proteins were identified by proteomic analysis. Of these, 206 proteins exhibited a significant difference in expression between keloid scar and normal skin tissues. RCN3 and CALU were significantly upregulated in keloids. RCN1 and PDGFRL were uniquely expressed in keloids. Pathway analysis suggested that the XBP1-mediated unfolded protein response (UPR) pathway was involved in keloid formation. Moreover, a PDGFRL centric gene coexpression network was constructed to illustrate its function in skin.Conclusions and Clinical Relevance Our study proposed four novel biomarkers and highlighted the role of XBP1-mediated UPR pathway in the pathology of keloids. It provided novel biological insights that contribute to develop novel therapeutic strategies for keloids.
|
|
| 355. |
- Liu, Niantao, et al.
(författare)
-
Facile high-voltage sputtering synthesis of three-dimensional hierarchical porous nitrogen-doped carbon coated Si composite for high performance lithium-ion batteries
- 2018
-
Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 343, s. 78-85
-
Tidskriftsartikel (refereegranskat)abstract
- Various kinds of efforts have been devoted to ameliorate the serious volume-expansion effect and low electron conductivity of silicon-based materials in lithium ion batteries. Here, we report a facile high voltage sputtering process to prepare three-dimensional hierarchical porous nitrogen-doped carbon coated Si microsphere to significantly improve the lithium storage performance. The structure and morphology of the as-obtained samples are characterized by X-ray diffraction, transmission electron microscope and scanning electron microscope. The results indicate that the as-prepared composite is composed of silicon nanoparticles (similar to 100 nm) coated with conductive thin carbon layer (similar to 8.5 nm). The composite shows excellent lithium storage performance with a reversible capacity of 1565 mAh g(-1) after 100 cycles at a current density of 0.5 A g(-1), as well as a long cycling performance at the high current density of 2 A g(-1). The facile preparation process and highly silicon-loading (similar to 78%) makes the prepared material be a great potential application in lithium-ion batteries.
|
|
| 356. |
- Liu, Wei, Assistant Professor, 1987-, et al.
(författare)
-
An open-source and experimentally guided CFD strategy for predicting air distribution in data centers with air-cooling
- 2023
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 242
-
Tidskriftsartikel (refereegranskat)abstract
- Data centers are generally over cooled to ensure the trouble free running. In a data center with air-cooling, it is crucial to investigate the air distribution and temperature field to aid the design, which ensures the stable operation with less energy consumption. Computational fluid dynamics (CFD) is perfect for such a mission, but the cost is high and the user is offered with little customization as commercial software are mostly adopted. Therefore, this study presented a systematic investigation on making use of open-source software, including OpenFOAM and paraView to realize geometry preparation, mesh generation, experimentally guided numerical setup and solution, and results visualization. A JAVA program was developed to ensure the case preparation and simulation in just one command. Self-adapted momentum sources were developed to realize the desired flow rate through the servers. The strategy was validated and demonstrated by a pilot data center from Alibaba cloud, Alibaba group. The developed solver predicted the air temperature in both cold and hot isles of a data center with mean error of 0.7 K. This work initiated a starting point for achieving automated CFD simulation of data centers with open-source tools.
|
|
| 357. |
- Liu, Wei, Assistant Professor, 1987-, et al.
(författare)
-
Modeling transient particle transport in transient indoor airflow by fast fluid dynamics with the Markov chain method
- 2020
-
Ingår i: Building and Environment. - : Elsevier Ltd. - 0360-1323 .- 1873-684X. ; 186
-
Tidskriftsartikel (refereegranskat)abstract
- It is crucial to accurately and efficiently predict transient particle transport in indoor environments to improve air distribution design and reduce health risks. For steady-state indoor airflow, fast fluid dynamics (FFD) + Markov chain model increased the calculation speed by around seven times compared to computational fluid dynamics (CFD) + Eulerian model and CFD + Lagrangian model, while achieving the same level of accuracy. However, the indoor airflow could be transient, if there were human behaviors involved like coughing or sneezing and air was supplied periodically. Therefore, this study developed an FFD + Markov chain model solver for predicting transient particle transport in transient indoor airflow. This investigation used two cases, transient particle transport in a ventilated two-zone chamber and a chamber with periodic air supplies, for validation. Case 1 had experimental data for validation and the results showed that the predicted particle concentration by FFD + Markov chain model matched well with the experimental data. Besides, it had similar accuracy as the CFD + Eulerian model. In the second case, the prediction by large eddy simulation (LES) was used for validating the FFD. The simulated particle concentrations by the Markov chain model and the Eulerian model were similar. The simulated particle concentrations by the Markov chain model and the Eulerian model were similar. The computational time of the FFD + Markov chain model was 7.8 times less than that of the CFD + Eulerian model.
|
|
| 358. |
- Liu, Wei, Assistant Professor, 1987-, et al.
(författare)
-
Performance of fast fluid dynamics with a semi-Lagrangian scheme and an implicit upwind scheme in simulating indoor/outdoor airflow
- 2022
-
Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 207:B
-
Tidskriftsartikel (refereegranskat)abstract
- Computational fluid dynamics can be time consuming for predicting indoor airflows and pollutant transport in large-scale problems or emergency management. Fast fluid dynamics (FFD) is able to accomplish efficient and accurate simulation of indoor/outdoor airflow. FFD solves the advection term of the Navier–Stokes equations either by a semi-Lagrangian (SL) scheme or an implicit upwind (IU) scheme. The SL scheme can be highly efficient, but its first-order version is not conservative and introduces significant numerical diffusion. To improve its accuracy, a high-order temporal and interpolation scheme that not only reduces dissipation and dispersion errors but also guarantees the convergence speed should be applied. Otherwise, an IU scheme instead could be used to solve the advection term. The IU scheme is conservative and introduces minor numerical diffusion, but it may increase the computation time. Therefore, this study investigated the performance of FFD with SL scheme using high-order temporal and interpolation schemes and that with IU scheme. The comparisons used experimental data of two indoor airflows and one outdoor airflow. The results showed that FFD with IU scheme was overall more accurate than FFD with SL scheme. In simulating indoor airflow, both methods were robust and the predictions were independent of time step sizes if the Courant number was less than or equal to one. In simulating the outdoor airflow, the FFD with SL scheme performed better than the FFD with IU scheme for large time step sizes. The FFD with IU scheme consumed 44%–61% computing time of the FFD with SL scheme.
|
|
| 359. |
- Liu, Wei, Assistant Professor, 1987-, et al.
(författare)
-
Prediction of transient particle transport in transient indoor airflow by integrated fast fluid dynamics and Markov chain model
- 2020
-
Ingår i: 16th Conference of the International Society of Indoor Air Quality and Climate. - : International Society of Indoor Air Quality and Climate.
-
Konferensbidrag (refereegranskat)abstract
- It is crucial to accurately and efficiently predict transient particle transport in indoor environments in order to improve air distribution design and reduce health risks. For the steady-state indoor airflow, our previous studies have found that the integrated fast fluid dynamics (FFD) + Markov chain model increased the speed of calculation by around seven times compared to the combination of computational fluid dynamics (CFD) + Eulerian model and CFD + Lagrangian model, while achieving the same level of accuracy. However, the indoor airflow could be transient, if there was a human behaviour involved like coughing or sneezing, opening the door, and supplying the air periodically. Therefore, this study developed an FFD + Markov chain model solver for predicting transient particle transport in transient indoor airflow in OpenFOAM. This investigation used transient particle transport in a ventilated two-zone chamber to validate the model. In this case, the validation used experimental data from literature and showed that the predicted particle concentration by FFD + Markov chain model matched well with the experimental data. Besides, it had similar accuracy as the FFD + Eulerian model and the CFD + Eulerian model. The FFD + Markov chain model requires a similar computational time with the FFD + Eulerian model if the same time step size was used.
|
|
| 360. |
- Liu, Wei, et al.
(författare)
-
The Synthesis of a Multiple D-A Conjugated Macrocycle and Its Application in Organic Photovoltaic
- 2023
-
Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773.
-
Tidskriftsartikel (refereegranskat)abstract
- As a novel class of materials, D-A conjugated macrocycles hold significant promise for chemical science. However, their potential in photovoltaic remains largely untapped due to the complexity of introducing multiple donor and acceptor moieties into the design and synthesis of cyclic pi-conjugated molecules. Here, we report a multiple D-A ring-like conjugated molecule (RCM) via the coupling of dimer molecule DBTP-C3 as a template and thiophenes in high yields. RCM exhibits a narrow optical gap (1.33 eV) and excellent thermal stability, and shows a remarkable photoluminescence yield (phi PL) of 11.1 % in solution, much higher than non-cyclic analogues. Organic solar cell (OSC) constructed with RCM as electron acceptor shows efficient charge separation at donor-acceptor band offsets and achieves a power conversion efficiency (PCE) of 14.2 %-approximately fourfold higher than macrocycle-based OSCs reported so far. This is partly due to low non-radiative voltage loss down to 0.20 eV and a high electroluminescence yield (phi EL) of 4x10-4. Our findings emphasize the potential of D-A cyclic conjugated molecules in advancing organic photovoltaic technology. A multiple D-A ring-like conjugated molecule, RCM was synthesized via a template-directed process. RCM inherits the superior photovoltaic properties characteristic of D-A linear molecules, including a narrow optical gap and effective charge transfer. Importantly, RCM demonstrates reduced non-radiative losses, attributable to its minimized vibration.+image
|
|
