| 1. |
- Zhang, Lixiu, et al.
(författare)
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Advances in the Application of Perovskite Materials
- 2023
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Ingår i: NANO-MICRO LETTERS. - : SHANGHAI JIAO TONG UNIV PRESS. - 2311-6706. ; 15:1
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Forskningsöversikt (refereegranskat)abstract
- Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices (solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices (artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.
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| 2. |
- Zhao, Xue, et al.
(författare)
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Two-dimensional BCN matrix inlaid with single-atom-Cu driven electrochemical nitrate reduction reaction to achieve sustainable industrial-grade production of ammonia
- 2021
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Ingår i: APPLIED MATERIALS TODAY. - : Elsevier. - 2352-9407. ; 25
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical methods have been proven to effectively eliminate nitrates in sewage and convert them into high value-added ammonia products. Here, after annealing treatment of metal boron cluster organic polymers formed by the combination of 1,10-phenanthroline, Cu2+ and closo-[B12H12](2)(-), a Cu single-atom doped BCN (B-doped CN) with a diamond-shaped nanosheet structure was obtained. In the electrochem-ical reduction reaction of nitrate, BCN-Cu exhibits excellent catalytic activity, specifically: 1) the ammonia yield rate reached as high as 498.85 mu g h(-1) cm(-2), 1047.14 mu g h(-1) cm(-2), 1900.07 mu g h(-1) cm(-2) and 3358.74 mu g h(-1) cm(-2) at -0.3 V, -0.4 V, -0.5 V and -0.6 V vs reversible hydrogen electrode, respectively, and Faradaic efficiency is 95.90%, 97.28%, 98.23% and 97.37%; 2) after repeated use of BCN-Cu 10 times or continuous operation for 16 h, the activity against electrochemical reduction reaction of nitrate anions is almost unchanged. The (NO3-)-N-15 isotopic labeling experiment proved that the detected NH3 comes from the reduction of NO3- on BCN-Cu. Control experiments show that the presence of Cu determines whether BCN-Cu has the possibility of catalyzing electrochemical reduction reactions of nitrate, and the presence of the B element enhances the catalytic activity of BCN-Cu. Density functional calculations indicate that in the water phase the process of reducing NO3- to NH3 on Cu-0 is an exothermic reaction, and that the adsorption process of NO3- on Cu-0 is the rate-determining step.
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| 3. |
- Cheng, Liu, et al.
(författare)
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EEG-CLNet : Collaborative Learning for Simultaneous Measurement of Sleep Stages and OSA Events Based on Single EEG Signal
- 2023
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Ingår i: IEEE Transactions on Instrumentation and Measurement. - : IEEE. - 0018-9456 .- 1557-9662. ; 72
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Tidskriftsartikel (refereegranskat)abstract
- Sleep-stage and apnea-hypopnea index (AHI) are the most important metrics in the diagnosis of sleep syndrome disease. In previous studies, these two tasks are usually implemented separately, which is both time- and resource-consuming. In this work, we propose a novel single electroencephalogram (EEG)-based collaborative learning network (EEG-CLNet) for simultaneous sleep staging and obstructive sleep apnea (OSA) event detection through multitask collaborative learning. The EEG-CLNet regards different tasks as a common unit to extract features from intragroups via both local parameter sharing and cross-task knowledge distillation (CTKD), rather than just sharing parameters or shortening the distance between different tasks. Our approach has been validated on two datasets with the same or better performance than other methods. The experimental results show that our method achieves a performance gain of 1%-5% compared with the baseline. Compared to previous works where two or even more models were required to perform sleep staging and OSA event detection, the EEG-CLNet could reduce the total number of model parameters and facilitate the model to mine the hidden relationships between different task semantic information. More importantly, it effectively alleviates the task bias problem in hard parameter sharing. As a consequence, this approach has notable potential to be a solution for a lightweight wearable sleep monitoring system in the future.
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| 4. |
- Peng, Yan, et al.
(författare)
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Cu Nanoparticle-Decorated Boron-Carbon-Nitrogen Nanosheets for Electrochemical Determination of Chloramphenicol
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:25, s. 28956-28964
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, irregular Cu nanoparticle-decorated boron-carbon-nitrogen (Cu-BCN) nanosheets were successfully synthesized. A Cu-BCN dispersion was deposited on a bare glassy carbon electrode (GCE) to prepare an electrochemical sensor (Cu-BCN/GCE) for the detection of chloramphenicol (CAP) in the environment. Cu-BCN was characterized using high-resolution scanning transmission electron microscopy (HRSTEM), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and X-ray photoelectron spectroscopy (XPS). The performance of the Cu-BCN/GCE was studied using electrochemical impedance spectroscopy (EIS), and its advantages were proven by electrode comparison. Differential pulse voltammetry (DPV) was used to optimize the experimental conditions, including the amount of Cu-BCN deposited, enrichment potential, deposition time, and pH of the electrolyte. A linear relationship between the CAP concentration and current response was obtained under the optimized experimental conditions, with a wide linear range and a limit of detection (LOD) of 2.41 nmol/L. Cu-BCN/GCE exhibited high stability, reproducibility, and repeatability. In the presence of various organic and inorganic species, the influence of the Cu-BCN-based sensor on the current response of CAP was less than 5%. Notably, the prepared sensor exhibited excellent performance in real-water samples, with satisfactory recovery.
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| 5. |
- Qi, Di, et al.
(författare)
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Climate change drives rapid decadal acidification in the Arctic Ocean from 1994 to 2020
- 2022
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 377:6614, s. 1544-1550
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic Ocean has experienced rapid warming and sea ice loss in recent decades, becoming the first open-ocean basin to experience widespread aragonite undersaturation [saturation state of aragonite (Warag) < 1]. However, its trend toward long-term ocean acidification and the underlying mechanisms remain undocumented. Here, we report rapid acidification there, with rates three to four times higher than in other ocean basins, and attribute it to changing sea ice coverage on a decadal time scale. Sea ice melt exposes seawater to the atmosphere and promotes rapid uptake of atmospheric carbon dioxide, lowering its alkalinity and buffer capacity and thus leading to sharp declines in pH and Warag. We predict a further decrease in pH, particularly at higher latitudes where sea ice retreat is active, whereas Arctic warming may counteract decreases in Warag in the future.
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| 6. |
- Zhang, Jibin, et al.
(författare)
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Ligand-Induced Cation-p Interactions Enable High-Efficiency, Bright, and Spectrally Stable Rec. 2020 Pure-Red Perovskite Light-Emitting Diodes
- 2023
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Ingår i: Advanced Materials. - : WILEY-V C H VERLAG GMBH. - 0935-9648 .- 1521-4095.
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Tidskriftsartikel (refereegranskat)abstract
- Achieving high-performance perovskite light-emitting diodes (PeLEDs) with pure-red electroluminescence for practical applications remains a critical challenge because of the problematic luminescence property and spectral instability of existing emitters. Herein, high-efficiency Rec. 2020 pure-red PeLEDs, simultaneously exhibiting exceptional brightness and spectral stability, based on CsPb(Br/I)(3) perovskite nanocrystals (NCs) capping with aromatic amino acid ligands featuring cation-pi interactions, are reported. It is proven that strong cation-pi interactions between the PbI6-octahedra of perovskite units and the electron-rich indole ring of tryptophan (TRP) molecules not only chemically polish the imperfect surface sites, but also markedly increase the binding affinity of the ligand molecules, leading to high photoluminescence quantum yields and greatly enhanced spectral stability of the CsPb(Br/I)(3) NCs. Moreover, the incorporation of small-size aromatic TRP ligands ensures superior charge-transport properties of the assembled emissive layers. The resultant devices emitting at around 635 nm demonstrate a champion external quantum efficiency of 22.8%, a max luminance of 12 910 cd m(-2), and outstanding spectral stability, representing one of the best-performing Rec. 2020 pure-red PeLEDs achieved so far.
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| 7. |
- Zhao, Xue, et al.
(författare)
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Copper confined in vesicle-like BCN cavities promotes electrochemical reduction of nitrate to ammonia in water
- 2021
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Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 9:41, s. 23675-23686
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical methods to convert high-concentration nitrates present in sewage into high-value-added ammonia do not just alleviate the problem of environmental pollution but also provide less energy-intensive alternatives to the Haber-Bosch process. In this work, a metal-boron organic polymer precursor was annealed at high temperature to obtain copper nanoparticles encapsulated in a vesicle-like BCN matrix (BCN@Cu). In the electrochemical reduction of nitrate (E-NIRR), this species exhibited excellent catalytic activity. Specifically, the ammonia yields of BCN@Cu under applied potentials of -0.3 V, -0.4 V, -0.5 V, and -0.6 V versus the reversible hydrogen electrode were 271.1 mu mol h(-1) mg(cat.)(-1), 354.8 mu mol h(-1) mg(cat.)(-1), 435.6 mu mol h(-1) mg(cat.)(-1), and 576.2 mu mol h(-1) mg(cat.)(-1), respectively, and the corresponding Faraday efficiencies were 86.3%, 88.0%, 89.3%, and 88.9%. Isotope labeling experiments with (NO3-)-N-15 confirmed that the detected ammonia had originated from the electrochemical reduction of NO3- on the catalyst surface. Moreover, the E-NIRR activity of BCN@Cu remained high even after using it ten consecutive times or 20 h of continuous operation, suggesting the practicality of the industrial application of BCN@Cu. The presence of copper was key in determining BCN@Cus E-NIRR activity, while the presence of boron greatly improved its catalytic performance. Furthermore, density functional theory calculations indicated that BCN does not itself promote the reaction but rather assists the dispersion of Cu nanoparticles, thereby expanding the catalysts active surface area.
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| 8. |
- Zhao, Xue, et al.
(författare)
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Hydrophobic boron organic polymers : Ultra-high capacity of enrichment and storage for chloroform
- 2020
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Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 385
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Tidskriftsartikel (refereegranskat)abstract
- Chloroform, a superstar widely applied as solvent, extractant, refrigerating fluid and adhesive, faces storage risks and environmental pressures. Herein, a brand-new strategy for storing and enriching chloroform is designed. It is shown that stable boron organic polymers BOPS-S3 with excellent hydrophobicity can be facilely prepared by combining Na-2[B12H12] and amphiphilic HBPB-14 molecules. The unique molecular structure of such as prepared polymers endows strong affinity with chloroform. BOPS-S3 possesses an ultra-high adsorption capacity of 46.9 g.g(-1) toward liquid chloroform, with a resulting gel that maintains a low volatilization rate. In addition, a stainless mesh coating with BOPS-S3 is shown to excellently remove chloroform vapor, likewise BOPS-S3 is shown efficient for removal of chloroform traces in water, with a residual amount lower than the allowable concentration in drinking water defined by the World Health Organization. This work provides a novel approach to store chloroform in transportation or other unstable conditions with unprecedented ramifications.
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| 9. |
- Zhao, Xue, et al.
(författare)
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Simultaneous anchoring of Ni nanoparticles and single-atom Ni on BCN matrix promotes efficient conversion of nitrate in water into high-value-added ammonia
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 433:Part 2
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical synthesis of ammonia driven by clean energy is expected to realize the supply of ammonia for distributed production of industry and agriculture. Here, nickel nanoparticles and nickel in the form of single atoms were simultaneously anchored on the electrochemically active carrier BCN matrix through a structured domain strategy, which realized a high-efficiency, high-value-added, conversion of nitrate in sewage. Specifically, the electrochemical nitrate reduction reaction (NIRR) driven by BCN@Ni in alkaline media achieves an ammonia yield rate as high as 2320.2 μg h−1 cm−2 (at −0.5 V vs RHE), and Faraday efficiency as high as 91.15% (at −0.3 V vs RHE). Even in neutral and acidic media, the ammonia yield rates of NIRR driven by BCN@Ni are as high as 1904.2 μg h−1 cm−2 and 2057.4 μg h−1 cm−2, respectively (at −0.4 V vs RHE). The 15NO3- isotope labeling experiment verified that the recorded ammonia all came from the electrochemical reduction of NO3– on BCN@Ni. Density functional theory (DFT) calculations show that both nano-Ni and single-atom Ni in BCN@Ni have the ability to electrochemically convert NO3– into NH3, and that the addition of BCN can further promote the NIRR on Ni.
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| 10. |
- Anani, Adi, 1944-, et al.
(författare)
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QoS-guaranteed packet scheduling in wireless networks
- 2009
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Ingår i: The Journal of China Universities of Posts and Telecommunications. - Amsterdam : Elsevier. - 1005-8885. ; 16:2, s. 63-67
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Tidskriftsartikel (refereegranskat)abstract
- To guarantee the quality of service (QoS) of a wireless network, a new packet scheduling algorithm using cross-layer design technique is proposed in this article. First, the demand of packet scheduling for multimedia transmission in wireless networks and the deficiency of the existing packet scheduling algorithms are analyzed. Then the model of the QoS-guaranteed packet scheduling (QPS) algorithm of high speed downlink packet access (HSDPA) and the cost function of packet transmission are designed. The calculation method of packet delay time for wireless channels is expounded in detail, and complete steps to realize the QPS algorithm are also given. The simulation results show that the QPS algorithm that provides the scheduling sequence of packets with calculated values can effectively improve the performance of delay and throughput.
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Antonelli, Massimo, et al.
(författare)
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Year in review in Intensive Care Medicine 2012. II : Pneumonia and infection, sepsis, coagulation, hemodynamics, cardiovascular and microcirculation, critical care organization, imaging, ethics and legal issues
- 2013
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; 39:3, s. 345-364
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Tidskriftsartikel (refereegranskat)
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| 29. |
- Arghavani, Abbas, et al.
(författare)
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Power-Adaptive Communication With Channel-Aware Transmission Scheduling in WBANs
- 2024
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Ingår i: IEEE Internet of Things Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 2327-4662. ; 11:9, s. 16087-16102
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Tidskriftsartikel (refereegranskat)abstract
- Radio links in wireless body area networks (WBANs) are highly subject to short and long-term attenuation due to the unstable network topology and frequent body blockage. This instability makes it challenging to achieve reliable and energy-efficient communication, but on the other hand, provides a great potential for the sending nodes to dynamically schedule the transmissions at the time with the best expected channel quality. Motivated by this, we propose improved Gilbert-Elliott Markov chain model (IGE), a memory-efficient Markov chain model to monitor channel fluctuations and provide a long-term channel prediction. We then design adaptive transmission power selection (ATPS), a deadline-constrained channel scheduling scheme that enables a sending node to buffer the packets when the channel is bad and schedule them to be transmitted when the channel is expected to be good within a deadline. ATPS can self-learn the pattern of channel changes without imposing a significant computation or memory overhead on the sending node. We evaluate the performance of ATPS through experiments using TelosB motes under different scenarios with different body postures and packet rates. We further compare ATPS with several state-of-the-art schemes, including the optimal scheduling policy, in which the optimal transmission time for each packet is calculated based on the collected received signal strength indicator (RSSI) samples in an off-line manner. The experimental results reveal that ATPS performs almost as efficiently as the optimal scheme in high-date-rate scenarios and has a similar trend on power level usage.
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| 30. |
- Arghavani, Mahdi, et al.
(författare)
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StopEG : Detecting when to stop exponential growth in TCP slow-start
- 2020
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Ingår i: Proceedings of the 2020 IEEE 45th Conference on Local Computer Networks (LCN 2020). - 9781728171586 - 9781728171593 ; , s. 77-87
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Konferensbidrag (refereegranskat)abstract
- TCP slow-start grows the congestion window exponentially, aims to quickly probe the throughput of the network path. Stopping this growth at the wrong time can affect the overall network performance. In this paper, we introduce StopEG, an efficient mechanism to accurately and quickly detect when to stop this exponential growth. StopEG reacts to the changes on congestion window size rather than traditional congestion signals such as packet loss. We show that theoretically the number of inflight packets in the forward path is no more than 56.8% of all the inflight packets when the bottleneck link is unsaturated, and use this value as the threshold to stop the exponential growth. StopEG is evaluated through simulations in ns-3 by incorporating it into Google's BBR congestion control algorithm. Simulation results demonstrate its effectiveness in BBR, with a reduction of ≈68% in the length of the bottleneck queue when new connections are initiated.
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| 31. |
- Chen, Chao, et al.
(författare)
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Effects of Salt Tracer Amount, Concentration and Kind on the Fluid Flow Behavior in a Hydrodynamic Model of Continuous Casting Tundish
- 2012
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Ingår i: Steel Research International. - : John Wiley & Sons. - 1611-3683 .- 1869-344X. ; 83:12, s. 1141-1151
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Tidskriftsartikel (refereegranskat)abstract
- The hydrodynamic modeling method that widely used to simulate the fluid flow was reconsidered and discussed in this paper. The effects of injected salt tracer amount, concentration and kind on the fluid flow behavior in a hydrodynamic model tundish were investigated. The results were compared with the mathematical modeling calculation results, that the tracer density effect was eliminated. The residence time distribution (RTD) curve of tracer introduced deviated to the left side of the calculated curve, besides the deviation was increased as dimensionless tracer amount (the ratio of tracer amount to hydrodynamic model tundish volume) increased from 0.202 × 10−3 to 1.008 × 10−3. The results of tracer concentration study were similar, namely the deviation was increased with concentration increased; on the other hand, the deformation of a “stair-shape” RTD curve occurred when tracer concentration was much lower (at dimensionless tracer amount of 0.168 × 10−3 with converting to saturated solution). Besides, the effect of tracer kind on the accuracy of hydrodynamic modeling was also studied; the measurements of KCl solution with lower density than that of NaCl solution exhibited more of accuracy. Finally, the optimized tracer in hydrodynamic model tundish of present work is saturated KCl solution with dimensionless tracer amount of 0.202 × 10−3.
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| 32. |
- Chen, Yawen, et al.
(författare)
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A Novel P-shape Tessellation Approach on Double-Loop Networks
- 2009
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Ingår i: 2009 IEEE INTERNATIONAL SYMPOSIUM ON IT IN MEDICINE & EDUCATION, VOLS 1 AND 2, PROCEEDINGS. - NEW YORK : IEEE. - 9781424439294 ; , s. 507-511
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Konferensbidrag (refereegranskat)abstract
- Double loop computer networks are widely used in the design and implementation of local area networks and parallel processing architectures. However the embedding problems on double-loop networks have not been well studied due to the complexity of double-loop networks. Since the traditional L-shape, designed to compute the diameter of double-loop networks, is not efficient to solve embedding problems, we propose a novel tessellation approach to partition the geometric plane of double-loop networks into a set of parallelogram shaped tiles, called P-shape. Our proposed tessellation technique, P-shape, is a useful theoretical tool for embedding meshes on double-loop networks, and can be extended to analyze other problems as a bridge between regular graphs and double-loop networks.
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| 33. |
- Cheng, Chunling, et al.
(författare)
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High speed data streams clustering algorithm based on improved SS tree
- 2012
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Ingår i: Innovative Computing Information and Control Express Letters, Part B. - : ICIC International. - 2185-2766. ; 3:1, s. 207-212
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Tidskriftsartikel (refereegranskat)abstract
- In high speed networks, data streams show rapid, bursting and continuous characteristics, which makes real-time clustering of data streams be a difficulty. An improved SS tree structure is designed in this paper to keep the summarized information of data streams. Then, a high speed data streams clustering algorithm based on improved SS tree is proposed. In order to process the bursting streams in time, caching and piggyback mechanisms are used. The chaining buffers in the improved SS tree are used to temporarily store the data stream objects which cannot be processed immediately, and then the contents in buffers will be piggybacked together with the following data. To meet high arrival of data streams, two-phase clustering framework is adopted. Pre-aggregation phase produces local micro-clusters. After that, local micro-clusters take part in the global clustering phase based on the improved SS tree. Experimental results show that the proposed algorithm has better clustering accuracy in high-speed networks. The improved SS tree can effectively cluster high speed data streams and has a good applicability.
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| 34. |
- Deng, Xuefan, et al.
(författare)
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A new strategy for boron cluster-based metal boride (Co2B) synthesis and its applicability to electrocatalytic nitrate reduction
- 2024
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Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 485
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Tidskriftsartikel (refereegranskat)abstract
- To achieve efficient conversion of nitrate to ammonia, it is necessary to design and develop electrode materials with high activity and efficiency for the electrocatalytic reduction reaction of nitrate (NO3RR). Due to its unique semi-metallic properties, the vacancy orbitals of boron are prone to accommodate electrons, so doping element B with transition metals is expected to change the local electronic configuration of the metal, which in turn affects the corresponding catalytic reaction. Here, we propose a new strategy for the preparation of metal borides by using dodecahydro-closo-dodecaborate and Co2+ complexed and calcined to prepare a novel metal boride-Co2B for electrocatalytic nitrate reduction. This modification considerably enhances the performance of NO3RR. Co2B exhibited a Faradaic efficiency of NH4+ (FENH4+) as high as 96.61 % at -0.5 V vs. RHE, achieving a remarkable NH4+ yield of 5.73 mg h-1 mgcat - 1. This study provides a new approach for designing catalysts for environmentallyfriendly ammonia synthesis.
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| 35. |
- Deng, Xuefan, et al.
(författare)
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A new strategy for boron cluster-based metal boride (Co2B) synthesis and its applicability to electrocatalytic nitrate reduction
- 2024
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 485
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Tidskriftsartikel (refereegranskat)abstract
- To achieve efficient conversion of nitrate to ammonia, it is necessary to design and develop electrode materials with high activity and efficiency for the electrocatalytic reduction reaction of nitrate (NO3RR). Due to its unique semi-metallic properties, the vacancy orbitals of boron are prone to accommodate electrons, so doping element B with transition metals is expected to change the local electronic configuration of the metal, which in turn affects the corresponding catalytic reaction. Here, we propose a new strategy for the preparation of metal borides by using dodecahydro-closo-dodecaborate and Co2+ complexed and calcined to prepare a novel metal boride-Co2B for electrocatalytic nitrate reduction. This modification considerably enhances the performance of NO3RR. Co2B exhibited a Faradaic efficiency of NH4+ (FENH4+) as high as 96.61 % at -0.5 V vs. RHE, achieving a remarkable NH4+ yield of 5.73 mg h-1 mgcat - 1. This study provides a new approach for designing catalysts for environmentallyfriendly ammonia synthesis.
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| 36. |
- Ghadimi, Euhanna, et al.
(författare)
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Hidden Terminal-Aware Contention Resolution With an Optimal Distribution
- 2011
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Ingår i: Proceedings - 8th IEEE International Conference on Mobile Ad-hoc and Sensor Systems, MASS 2011. - 9780769544694 ; , s. 182-191
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Konferensbidrag (refereegranskat)abstract
- Achieving low-power operation in wireless sensor networks with high data load or bursty traffic is challenging. The hidden terminal problem is aggravated with increased amounts of data in which traditional backoff-based contention resolution mechanisms fail or induce high latency and energy costs. We analyze and optimize Strawman, a receiver-initiated contention resolution mechanism that copes with hidden terminals. We propose new techniques to boost the performance of Strawman while keeping the resolution overhead small. We finally validate our improved mechanism via experiments.
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| 37. |
- Guo (郭佳诚), Jiacheng, et al.
(författare)
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Vortex dynamics and fin-fin interactions resulting in performance enhancement in fish-like propulsion
- 2023
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Ingår i: Physical Review Fluids. - 2469-990X. ; 8:7
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Tidskriftsartikel (refereegranskat)abstract
- The leading-edge vortex (LEV) formation on the caudal fin (CF) has been identified as playing a key role in efficient lift-based thrust production of fish-like propulsion. The enhancement of the CF LEV through its interaction with vortices formed upstream due to a median fin with a distinct shape is the focus of this paper. High-speed, high-fidelity videos and particle imaging velocimetry (PIV) were obtained from rainbow trout during steady forward swimming to visualize the undulatory kinematics and two-dimensional flow behavior. Body kinematics are quantified using a traveling-wave formulation that is used to prescribe the motion of a high-fidelity three-dimensional surface model of the fish body for a computational fluid dynamics (CFD) study. The pressure field of the CFD result is compared and validated with the PIV result from the experiment. Using CFD, the vortex forming and shedding behaviors of the anal fin (AF) and their capturing and interaction with the trunk (TK) and the CF are visualized and examined. Coherent AF-bound LEVs are found to form periodically, leading to thrust production of the AF. The vortices subsequently shed from the AF are found to help stabilize and reinforce the LEV formation on the CF by aiding LEV initiation at stroke reversal and enhancing LEV during a tail stroke, which leads to enhancement of lift-based thrust production. The CF is found to shed vortex tubes (VTs) that create backward-facing jets, and the ventral-side VT and the associated backward jets are both strengthened by vortices shed by the AF. An additional benefit of the AF is found to be reduction of body drag by reducing the lateral crossflow that leads to loss of beneficial pressure gradient across the body. Through varying AF-CF spacing and AF height, we find that CF thrust enhancement and TK drag reduction due to the AF are both affected by the position and size of the AF. The position and area of the AF that led to the most hydrodynamic benefit are found to be the original, anatomically accurate position and size. In this paper, we demonstrate the important effect of vortex interaction among propulsive surfaces in fish-like propulsion.
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| 38. |
- Kapur, Rick, et al.
(författare)
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T regulatory cells and dendritic cells protect against transfusion-related acute lung injury via IL-10
- 2017
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 129:18, s. 2557-2569
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Tidskriftsartikel (refereegranskat)abstract
- Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatalities and is characterized by acute respiratory distress following blood transfusion. Donor antibodies are frequently involved; however, the pathogenesis and protective mechanisms in the recipient are poorly understood, and specific therapies are lacking. Using newly developed murine TRALI models based on injection of anti-major histocompatibility complex class I antibodies, we found CD4+CD25+FoxP3+ T regulatory cells (Tregs) and CD11c+ dendritic cells (DCs) to be critical effectors that protect against TRALI. Treg or DC depletion in vivo resulted in aggravated antibody-mediated acute lung injury within 90 minutes with 60% mortality upon DC depletion. In addition, resistance to antibody-mediated TRALI was associated with increased interleukin-10 (IL-10) levels, and IL-10 levels were found to be decreased in mice suffering from TRALI. Importantly, IL-10 injection completely prevented and rescued the development of TRALI in mice and may prove to be a promising new therapeutic approach for alleviating lung injury in this serious complication of transfusion.
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| 39. |
- Li, Fei, et al.
(författare)
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Quantum Bacterial Foraging Optimization Algorithm
- 2014
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Ingår i: 2014 IEEE CONGRESS ON EVOLUTIONARY COMPUTATION (CEC). - : IEEE Press. - 9781479914883 ; , s. 1265-1272
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Konferensbidrag (refereegranskat)abstract
- This paper proposes a novel swarm intelligence optimization method which integrates bacterial foraging optimization (BFO) with quantum computing, called quantum bacterial foraging optimization (QBFO) algorithm. In QBFO, a multi-qubit which can represent a linear superposition of states in search space probabilistically is used to represent a bacterium, so that the quantum bacteria representation has a better characteristic of population diversity. A quantum rotation gate is designed to simulate the chemotactic step to drive the bacteria toward better solutions. Several tests are conducted based on benchmark functions including multi-peak function to evaluate optimization performance of the proposed algorithm. The numeric results show that the proposed QBFO has more powerful properties in convergence rate, stability and the ability of searching for the global optimal solution than the original BFO and quantum genetic algorithm. In addition, we applied our proposed QBFO to solve the traveling salesman problem, which is a well-known NP-hard problem in combinatorial optimization. The results indicate that the proposed QBFO shows better convergence behavior without premature convergence, and has more powerful properties in convergence rate, stability and the ability of searching for the global optimal solution, as compared to ant colony optimization algorithm and quantum genetic algorithm.
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| 40. |
- Li, June, et al.
(författare)
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Desialylated Platelet Clearance in the Liver is a Novel Mechanism of Systemic Immunosuppression
- 2023
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Ingår i: Research. - 2096-5168. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Platelets are small, versatile blood cells that are critical for hemostasis/thrombosis. Local platelet accumulation is a known contributor to proinflammation in various disease states. However, the anti-inflammatory/immunosuppressive potential of platelets has been poorly explored. Here, we uncovered, unexpectedly, desialylated platelets (dPLTs) down-regulated immune responses against both platelet-associated and -independent antigen challenges. Utilizing multispectral photoacoustic tomography, we tracked dPLT trafficking to gut vasculature and an exclusive Kupffer cell-mediated dPLT clearance in the liver, a process that we identified to be synergistically dependent on platelet glycoprotein Ibα and hepatic Ashwell-Morell receptor. Mechanistically, Kupffer cell clearance of dPLT potentiated a systemic immunosuppressive state with increased anti-inflammatory cytokines and circulating CD4+ regulatory T cells, abolishable by Kupffer cell depletion. Last, in a clinically relevant model of hemophilia A, presensitization with dPLT attenuated anti-factor VIII antibody production after factor VIII ( infusion. As platelet desialylation commonly occurs in daily-aged and activated platelets, these findings open new avenues toward understanding immune homeostasis and potentiate the therapeutic potential of dPLT and engineered dPLT transfusions in controlling autoimmune and alloimmune diseases.
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| 41. |
- Li, Sirui, et al.
(författare)
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Glioma grading, molecular feature classification, and microstructural characterization using MR diffusional variance decomposition (DIVIDE) imaging
- 2021
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 31:11, s. 8197-8207
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To evaluate the potential of diffusional variance decomposition (DIVIDE) for grading, molecular feature classification, and microstructural characterization of gliomas. Materials and methods: Participants with suspected gliomas underwent DIVIDE imaging, yielding parameter maps of fractional anisotropy (FA), mean diffusivity (MD), anisotropic mean kurtosis (MKA), isotropic mean kurtosis (MKI), total mean kurtosis (MKT), MKA/MKT, and microscopic fractional anisotropy (μFA). Tumor type and grade, isocitrate dehydrogenase (IDH) 1/2 mutant status, and the Ki-67 labeling index (Ki-67 LI) were determined after surgery. Statistical analysis included 33 high-grade gliomas (HGG) and 17 low-grade gliomas (LGG). Tumor diffusion metrics were compared between HGG and LGG, among grades, and between wild and mutated IDH types using appropriate tests according to normality assessment results. Receiver operating characteristic and Spearman correlation analysis were also used for statistical evaluations. Results: FA, MD, MKA, MKI, MKT, μFA, and MKA/MKT differed between HGG and LGG (FA: p = 0.047; MD: p = 0.037, others p < 0.001), and among glioma grade II, III, and IV (FA: p = 0.048; MD: p = 0.038, others p < 0.001). All diffusion metrics differed between wild-type and mutated IDH tumors (MKI: p = 0.003; others: p < 0.001). The metrics that best discriminated between HGG and LGGs and between wild-type and mutated IDH tumors were MKT and FA respectively (area under the curve 0.866 and 0.881). All diffusion metrics except FA showed significant correlation with Ki-67 LI, and MKI had the highest correlation coefficient (rs = 0.618). Conclusion: DIVIDE is a promising technique for glioma characterization and diagnosis. Key Points: • DIVIDE metrics MKIis related to cell density heterogeneity while MKAand μFA are related to cell eccentricity. • DIVIDE metrics can effectively differentiate LGG from HGG and IDH mutation from wild-type tumor, and showed significant correlation with the Ki-67 labeling index. • MKIwas larger than MKAwhich indicates predominant cell density heterogeneity in gliomas. • MKAand MKIincreased with grade or degree of malignancy, however with a relatively larger increase in the cell eccentricity metric MKAin relation to the cell density heterogeneity metric MKI.
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| 42. |
- Lu, Haibo, et al.
(författare)
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Comparing machine learning-derived global estimates of soil respiration and its components with those from terrestrial ecosystem models
- 2021
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 16:5
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Tidskriftsartikel (refereegranskat)abstract
- The CO2 efflux from soil (soil respiration (SR)) is one of the largest fluxes in the global carbon (C) cycle and its response to climate change could strongly influence future atmospheric CO2 concentrations. Still, a large divergence of global SR estimates and its autotrophic (AR) and heterotrophic (HR) components exists among process based terrestrial ecosystem models. Therefore, alternatively derived global benchmark values are warranted for constraining the various ecosystem model output. In this study, we developed models based on the global soil respiration database (version 5.0), using the random forest (RF) method to generate the global benchmark distribution of total SR and its components. Benchmark values were then compared with the output of ten different global terrestrial ecosystem models. Our observationally derived global mean annual benchmark rates were 85.5 ± 40.4 (SD) Pg C yr-1 for SR, 50.3 ± 25.0 (SD) Pg C yr-1 for HR and 35.2 Pg C yr-1 for AR during 1982-2012, respectively. Evaluating against the observations, the RF models showed better performance in both of SR and HR simulations than all investigated terrestrial ecosystem models. Large divergences in simulating SR and its components were observed among the terrestrial ecosystem models. The estimated global SR and HR by the ecosystem models ranged from 61.4 to 91.7 Pg C yr-1 and 39.8 to 61.7 Pg C yr-1, respectively. The most discrepancy lays in the estimation of AR, the difference (12.0-42.3 Pg C yr-1) of estimates among the ecosystem models was up to 3.5 times. The contribution of AR to SR highly varied among the ecosystem models ranging from 18% to 48%, which differed with the estimate by RF (41%). This study generated global SR and its components (HR and AR) fluxes, which are useful benchmarks to constrain the performance of terrestrial ecosystem models.
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| 43. |
- Ma, Dan, et al.
(författare)
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A state-of-the-art review on rock seepage mechanism of water inrush disaster in coal mines
- 2022
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Ingår i: International Journal of Coal Science & Technology. - : Springer Nature. - 2095-8293 .- 2198-7823. ; 9:1
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Forskningsöversikt (refereegranskat)abstract
- Water inrush is one of the most dangerous disasters in coal mining. Due to the large-scale mining and complicated hydrogeological conditions, thousands of deaths and huge economic losses have been caused by water inrush disasters in China. There are two main factors determining the occurrence of water inrush: water source and water-conducting pathway. Research on the formation mechanism of the water-conducting pathway is the main direction to prevent and control the water inrush, and the seepage mechanism of rock mass during the formation of the water-conducting pathway is the key for the research on the water inrush mechanism. This paper provides a state-of-the-art review of seepage mechanisms during water inrush from three aspects, i.e., mechanisms of stress-seepage coupling, flow regime transformation and rock erosion. Through numerical methods and experimental analysis, the evolution law of stress and seepage fields in the process of water inrush is fully studied; the fluid movement characteristics under different flow regimes are clearly summarized; the law of particle initiation and migration in the process of water inrush is explored, and the effect of rock erosion on hydraulic and mechanical properties of the rock media is also studied. Finally, some limitations of current research are analyzed, and the suggestions for future research on water inrush are proposed in this review.
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| 44. |
- Maddali, Manoj V., et al.
(författare)
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Validation and utility of ARDS subphenotypes identified by machine-learning models using clinical data : an observational, multicohort, retrospective analysis
- 2022
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Ingår i: The Lancet Respiratory Medicine. - 2213-2600. ; 10:4, s. 367-377
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Tidskriftsartikel (refereegranskat)abstract
- Background: Two acute respiratory distress syndrome (ARDS) subphenotypes (hyperinflammatory and hypoinflammatory) with distinct clinical and biological features and differential treatment responses have been identified using latent class analysis (LCA) in seven individual cohorts. To facilitate bedside identification of subphenotypes, clinical classifier models using readily available clinical variables have been described in four randomised controlled trials. We aimed to assess the performance of these models in observational cohorts of ARDS. Methods: In this observational, multicohort, retrospective study, we validated two machine-learning clinical classifier models for assigning ARDS subphenotypes in two observational cohorts of patients with ARDS: Early Assessment of Renal and Lung Injury (EARLI; n=335) and Validating Acute Lung Injury Markers for Diagnosis (VALID; n=452), with LCA-derived subphenotypes as the gold standard. The primary model comprised only vital signs and laboratory variables, and the secondary model comprised all predictors in the primary model, with the addition of ventilatory variables and demographics. Model performance was assessed by calculating the area under the receiver operating characteristic curve (AUC) and calibration plots, and assigning subphenotypes using a probability cutoff value of 0·5 to determine sensitivity, specificity, and accuracy of the assignments. We also assessed the performance of the primary model in EARLI using data automatically extracted from an electronic health record (EHR; EHR-derived EARLI cohort). In Large Observational Study to Understand the Global Impact of Severe Acute Respiratory Failure (LUNG SAFE; n=2813), a multinational, observational ARDS cohort, we applied a custom classifier model (with fewer variables than the primary model) to determine the prognostic value of the subphenotypes and tested their interaction with the positive end-expiratory pressure (PEEP) strategy, with 90-day mortality as the dependent variable. Findings: The primary clinical classifier model had an area under receiver operating characteristic curve (AUC) of 0·92 (95% CI 0·90–0·95) in EARLI and 0·88 (0·84–0·91) in VALID. Performance of the primary model was similar when using exclusively EHR-derived predictors compared with manually curated predictors (AUC=0·88 [95% CI 0·81–0·94] vs 0·92 [0·88–0·97]). In LUNG SAFE, 90-day mortality was higher in patients assigned the hyperinflammatory subphenotype than in those with the hypoinflammatory phenotype (414 [57%] of 725 vs 694 [33%] of 2088; p<0·0001). There was a significant treatment interaction with PEEP strategy and ARDS subphenotype (p=0·041), with lower 90-day mortality in the high PEEP group of patients with the hyperinflammatory subphenotype (hyperinflammatory subphenotype: 169 [54%] of 313 patients in the high PEEP group vs 127 [62%] of 205 patients in the low PEEP group; hypoinflammatory subphenotype: 231 [34%] of 675 patients in the high PEEP group vs 233 [32%] of 734 patients in the low PEEP group). Interpretation: Classifier models using clinical variables alone can accurately assign ARDS subphenotypes in observational cohorts. Application of these models can provide valuable prognostic information and could inform management strategies for personalised treatment, including application of PEEP, once prospectively validated. Funding: US National Institutes of Health and European Society of Intensive Care Medicine.
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| 45. |
- Parreiras, Lucas S., et al.
(författare)
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Engineering and two-stage evolution of a lignocellulosic hydrolysate-tolerant Saccharomyces cerevisiae strain for anaerobic fermentation of xylose from AFEX pretreated corn stover
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:9
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Tidskriftsartikel (refereegranskat)abstract
- The inability of the yeast Saccharomyces cerevisiae to ferment xylose effectively under anaerobic conditions is a major barrier to economical production of lignocellulosic biofuels. Although genetic approaches have enabled engineering of S. cerevisiae to convert xylose efficiently into ethanol in defined lab medium, few strains are able to ferment xylose from lignocellulosic hydrolysates in the absence of oxygen. This limited xylose conversion is believed to result from small molecules generated during biomass pretreatment and hydrolysis, which induce cellular stress and impair metabolism. Here, we describe the development of a xylose-fermenting S. cerevisiae strain with tolerance to a range of pretreated and hydrolyzed lignocellulose, including Ammonia Fiber Expansion (AFEX)-pretreated corn stover hydrolysate (ACSH). We genetically engineered a hydrolysate-resistant yeast strain with bacterial xylose isomerase and then applied two separate stages of aerobic and anaerobic directed evolution. The emergent S. cerevisiae strain rapidly converted xylose from lab medium and ACSH to ethanol under strict anaerobic conditions. Metabolomic, genetic and biochemical analyses suggested that a missense mutation in GRE3, which was acquired during the anaerobic evolution, contributed toward improved xylose conversion by reducing intracellular production of xylitol, an inhibitor of xylose isomerase. These results validate our combinatorial approach, which utilized phenotypic strain selection, rational engineering and directed evolution for the generation of a robust S. cerevisiae strain with the ability to ferment xylose anaerobically from ACSH.
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| 46. |
- Pesonen, Joonas, et al.
(författare)
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Methodology and tools for controller-networking codesign in WirelessHART
- 2009
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Ingår i: ETFA 2009 - 2009 IEEE Conference on Emerging Technologies and Factory Automation. - : IEEE conference proceedings. - 9781424427284
-
Konferensbidrag (refereegranskat)abstract
- This paper describes a methodology for controller and communication scheduling co-design in control systems operating over wirelessHART networks. Data collection and dissemination operations are identified and scheduled to minimize the nominal communication latency. Techniques for improving the reliability of the network when link transmissions are unreliable are discussed, and a Markov-chain model for computing the latency distribution of data collection operations for a given schedule is proposed. The resulting latency models allow to represent the networked control loop as a jump-linear system, whose performance can be analyzed using techniques from stochastic control. We demonstrate how this framework can be used to co-design a networked LQG controller for a five-by-five MIMO control loop.
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| 47. |
- Soldati, Pablo, et al.
(författare)
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Deadline-constrained transmission scheduling and data evacuation in wireless HART networks
- 2009
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Ingår i: Proceedings of ECC. - : IEEE. - 9783952417393 ; , s. 4320-4325
-
Konferensbidrag (refereegranskat)abstract
- Real-time data delivery is a critical issue in wirelessHART networks. This paper develops a novel mathematical programming framework for joint routing and link scheduling of deadline-constrained traffic in wirelessHART networks. The general framework explores dynamic network flows on a time-expanded graph model and can provide flexible solutions for a variety of real-time data delivery problems. Data evacuation, an important communication paradigm in wirelessHART networks, is a special case of this general framework. We establish the lower bound on evacuation time for line, multi-line and binary tree networks. Moreover, we design a novel scheduling algorithm for data evacuation in binary tree networks, and prove that this scheduling algorithm can always achieve the lower bound on evacuation time. We evaluate our scheduling algorithm through numerical simulations, and results show that our algorithm can always minimize the evacuation time with the least number of channels.
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| 48. |
- Soldati, Pablo, et al.
(författare)
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Optimal Routing and Scheduling of Deadline-Constrained Traffic Over Lossy Networks
- 2010
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Ingår i: 2010 IEEE GLOBAL TELECOMMUNICATIONS CONFERENCE GLOBECOM 2010. - 9781424456383
-
Konferensbidrag (refereegranskat)abstract
- The traditionally wired automation infrastructure is quickly migrating to more flexible and scalable wireless solutions. To cope with the stringent requirements of process automation in terms of latency and reliability, the network resources must be optimized to ensure timely and reliable communication. This paper considers the joint routing and transmission scheduling problem for reliable real-time communication over lossy networks. Specifically, we impose a strict latency bound for packet delivery from source to destination, and devise optimal transmission scheduling policies that maximize the success probability of delivering the packet within the specified deadline. A solution to this problem allows to characterize the set of achievable latencies and packet reliability for a given network. We offer a complete understanding of the problem when erasure events on links are independent and follow a Bernoulli process. We consider both static and dynamic resource allocation policies, and compare them in numerical examples.
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| 49. |
- Teng, Fei, et al.
(författare)
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Multimedia Monitoring System of Obstructive Sleep Apnea via Deep Active Learning Model
- 2022
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Ingår i: IEEE Multimedia. - : IEEE. - 1070-986X .- 1941-0166. ; 29:3, s. 48-56
-
Tidskriftsartikel (refereegranskat)abstract
- Obstructive Sleep Apnea (OSA) is one of the most common sleep-related breathing disorders. Nearly 1 billion people worldwide suffer from it, causing serious health effects and social burden. However, traditional monitoring systems often fall short in terms of cost and accessibility. In this article, we first propose a deep active learning model to detect OSA events from electrocardiogram (ECG). We then designed and developed a prototype of OSA monitoring system using ECG sensor and smartphone, in which our OSA detection algorithm is implemented and validated. Experiments show that we achieve accuracy of 92.15% while using 40% of labeled data, significantly reducing the cost of labeling and maximizing the performance. According to detection results and health-related multimedia signals, we provide OSA risk level and medical advice to users. We believe that the multimedia monitoring system can efficiently help diagnose OSA, which could lead to effective intervention strategies and better sleep care.
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| 50. |
- Villacampa, Eva Gracia, et al.
(författare)
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Genome-wide Spatial Expression Profiling in Formalin-fixed Tissues
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Formalin-fixed paraffin embedding (FFPE) is the most widespread long-term tissue preservation approach. Here we present a procedure to perform genome-wide spatial analysis of mRNA in FFPE fixed tissue sections. The procedure takes advantage of well-established, commercially available methods for imaging and spatial barcoding using slides spotted with barcoded oligo(dT) probes to capture the 3’ end of mRNA molecules in tissue sections. First, we conducted expression profiling and cell type mapping in coronal sections from the mouse brain to demonstrate the method’s capability to delineate anatomical regions from a molecular perspective. Second, we explored the spatial composition of transcriptomic signatures in ovarian carcinosarcoma samples using data-driven analysis methods, exemplifying the method’s potential to elucidate molecular mechanisms in heterogeneous clinical samples. Finally, we demonstrate the applicability of the assay to characterize organoids and a human lung biopsy specimen infected with SARS-CoV-2.
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