| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Huang, Hongyun, et al.
(författare)
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Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)
- 2018
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Ingår i: Cell Transplantation. - : SAGE Publications. - 0963-6897 .- 1555-3892. ; 27:2, s. 310-324
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Forskningsöversikt (refereegranskat)abstract
- Cell therapy has been shown to be a key clinical therapeutic option for central nervous system diseases or damage. Standardization of clinical cell therapy procedures is an important task for professional associations devoted to cell therapy. The Chinese Branch of the International Association of Neurorestoratology (IANR) completed the first set of guidelines governing the clinical application of neurorestoration in 2011. The IANR and the Chinese Association of Neurorestoratology (CANR) collaborated to propose the current version "Clinical Cell Therapy Guidelines for Neurorestoration (IANR/CANR 2017)". The IANR council board members and CANR committee members approved this proposal on September 1, 2016, and recommend it to clinical practitioners of cellular therapy. These guidelines include items of cell type nomenclature, cell quality control, minimal suggested cell doses, patient-informed consent, indications for undergoing cell therapy, contraindications for undergoing cell therapy, documentation of procedure and therapy, safety evaluation, efficacy evaluation, policy of repeated treatments, do not charge patients for unproven therapies, basic principles of cell therapy, and publishing responsibility.
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| 3. |
- Konold, Patrick E., et al.
(författare)
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3D-printed sheet jet for stable megahertz liquid sample delivery at X-ray free-electron lasers
- 2023
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Ingår i: IUCrJ. - : International Union Of Crystallography. - 2052-2525. ; 10, s. 662-670
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Tidskriftsartikel (refereegranskat)abstract
- X-ray free-electron lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial and temporal resolution. A principal challenge in this pursuit involves the delivery of samples to the X-ray interaction point in such a way that produces data of the highest possible quality and with maximal efficiency. This is hampered by intrinsic constraints posed by the light source and operation within a beamline environment. For liquid samples, the solution typically involves some form of high-speed liquid jet, capable of keeping up with the rate of X-ray pulses. However, conventional jets are not ideal because of radiation-induced explosions of the jet, as well as their cylindrical geometry combined with the X-ray pointing instability of many beamlines which causes the interaction volume to differ for every pulse. This complicates data analysis and contributes to measurement errors. An alternative geometry is a liquid sheet jet which, with its constant thickness over large areas, eliminates the problems related to X-ray pointing. Since liquid sheets can be made very thin, the radiation-induced explosion is reduced, boosting their stability. These are especially attractive for experiments which benefit from small interaction volumes such as fluctuation X-ray scattering and several types of spectroscopy. Although their use has increased for soft X-ray applications in recent years, there has not yet been wide-scale adoption at XFELs. Here, gas-accelerated liquid sheet jet sample injection is demonstrated at the European XFEL SPB/SFX nano focus beamline. Its performance relative to a conventional liquid jet is evaluated and superior performance across several key factors has been found. This includes a thickness profile ranging from hundreds of nanometres to 60 nm, a fourfold increase in background stability and favorable radiation-induced explosion dynamics at high repetition rates up to 1.13 MHz. Its minute thickness also suggests that ultrafast single-particle solution scattering is a possibility.
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| 4. |
- Konold, Patrick, et al.
(författare)
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Microsecond time-resolved X-ray scattering by utilizing MHz repetition rate at second-generation XFELs
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Detecting microsecond structural perturbations in biomolecules has wide relevance inbiology, chemistry, and medicine. Here, we show how MHz repetition rates at X-ray freeelectron lasers (XFELs) can be used to produce microsecond time-series of proteinscattering with exceptionally low noise levels of 0.001%. We demonstrate the approach byderiving new mechanistic insight into Jɑ helix unfolding of a Light-Oxygen-Voltage (LOV)photosensory domain. This time-resolved acquisition strategy is easy to implement andwidely applicable for direct observation of structural dynamics of many biochemicalprocesses.
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| 5. |
- Liu, Cheng, et al.
(författare)
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Tuning the composition of heavy metal-free quaternary quantum dots for improved photoelectrochemical performance
- 2021
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 9:9, s. 5825-5832
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Tidskriftsartikel (refereegranskat)abstract
- Colloidal quantum dots (QDs) are promising building blocks towards the development of cost-effective and high-efficiency photoelectrochemical (PEC) cells. Unfortunately, the frequent use of QDs possessing heavy metals (e.g. Cd and Pb) in state-of-the-art QD-based PEC technologies is a major obstacle regarding their future commercial perspective. In this work, we synthesized heavy metal-free quaternary CuZnInS3 (CZIS) with variable Cu : Zn ratios and fabricated corresponding QDs-PEC devices via a facile chemical bath deposition (CBD) technique. It is revealed that the tuned CZIS (1Zn) QDs (i.e. Cu : Zn ratio of 1 : 1) can result in optimized optical properties including enhanced quantum yield, suppressed nonradiative recombination and extended excitonic lifetime. Accordingly, as-fabricated CZIS (1Zn) QD-based photoanodes demonstrated increased charge transfer rate and decreased electron transport resistance for improved PEC performance. The results indicate that tuning the composition of heavy metal-free multinary QDs is one of the promising pathways to achieve eco-friendly and high-performance PEC systems for solar hydrogen production.
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| 6. |
- Miao, Yanfeng, et al.
(författare)
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Stable and bright formamidinium-based perovskite light-emitting diodes with high energy conversion efficiency
- 2019
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Solution-processable perovskites show highly emissive and good charge transport, making them attractive for low-cost light-emitting diodes (LEDs) with high energy conversion efficiencies. Despite recent advances in device efficiency, the stability of perovskite LEDs is still a major obstacle. Here, we demonstrate stable and bright perovskite LEDs with high energy conversion efficiencies by optimizing formamidinium lead iodide films. Our LEDs show an energy conversion efficiency of 10.7%, and an external quantum efficiency of 14.2% without outcoupling enhancement through controlling the concentration of the precursor solutions. The device shows low efficiency droop, i.e. 8.3% energy conversion efficiency and 14.0% external quantum efficiency at a current density of 300 mA cm(-2), making the device more efficient than state-of-the-art organic and quantum-dot LEDs at high current densities. Furthermore, the half-lifetime of device with benzylamine treatment is 23.7 hr under a current density of 100 mA cm(-2), comparable to the lifetime of near-infrared organic LEDs.
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| 7. |
- Tong, Xin, et al.
(författare)
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Boosting the performance of eco-friendly quantum dots-based photoelectrochemical cells via effective surface passivation
- 2020
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 76
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectrochemical (PEC) cells fabricated using environment-friendly colloidal quantum dots (QDs) are promising optoelectronic devices for future practical solar-to-hydrogen conversion. However, the majority of current eco-friendly QDs-based PEC cells exhibited low efficiency mainly due to the charge trapping at QDs’ surface states and interfacial recombination processes in devices. Here, eco-friendly AgInS2 (AIS) QDs-based PEC cells passivated with variable ZnS layers were fabricated and the effects of ZnS surface passivation on corresponding device performance were investigated. It is demonstrated that optimizing the thickness of the ZnS passivation layers can largely suppress the charge trapping/recombination and enhance the electron injection efficiency in the PEC devices, leading to a saturated photocurrent density of ∼5.7 mA/cm2 under standard AM 1.5 G solar illumination. Increasing the thickness of ZnS passivation layers can further inhibit the photocorrosion and give rise to higher device stability. These results indicate that ZnS surface passivation is a facile and efficient technique to boost the performance of eco-friendly QDs-based PEC cells.
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| 8. |
- Wang, Cheng-Xiang, et al.
(författare)
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On the Road to 6G: Visions, Requirements, Key Technologies, and Testbeds
- 2023
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Ingår i: IEEE Communications Surveys and Tutorials. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 1553-877X. ; 25:2, s. 905-974
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Tidskriftsartikel (refereegranskat)abstract
- Fifth generation (5G) mobile communication systems have entered the stage of commercial deployment, providing users with new services, improved user experiences as well as a host of novel opportunities to various industries. However, 5G still faces many challenges. To address these challenges, international industrial, academic, and standards organizations have commenced research on sixth generation (6G) wireless communication systems. A series of white papers and survey papers have been published, which aim to define 6G in terms of requirements, application scenarios, key technologies, etc. Although ITU-R has been working on the 6G vision and it is expected to reach a consensus on what 6G will be by mid-2023, the related global discussions are still wide open and the existing literature has identified numerous open issues. This paper first provides a comprehensive portrayal of the 6G vision, technical requirements, and application scenarios, covering the current common understanding of 6G. Then, a critical appraisal of the 6G network architecture and key technologies is presented. Furthermore, existing testbeds and advanced 6G verification platforms are detailed for the first time. In addition, future research directions and open challenges are identified to stimulate the on-going global debate. Finally, lessons learned to date concerning 6G networks are discussed.
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| 9. |
- Wang, Kuan, et al.
(författare)
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Threshold switching memristor-based stochastic neurons for probabilistic computing
- 2021
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Ingår i: Materials Horizons. - : Royal Society of Chemistry. - 2051-6347 .- 2051-6355. ; 8:2, s. 619-629
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Tidskriftsartikel (refereegranskat)abstract
- Biological neurons exhibit dynamic excitation behavior in the form of stochastic firing, rather than stiffly giving out spikes upon reaching a fixed threshold voltage, which empowers the brain to perform probabilistic inference in the face of uncertainty. However, owing to the complexity of the stochastic firing process in biological neurons, the challenge of fabricating and applying stochastic neurons with bio-realistic dynamics to probabilistic scenarios remains to be fully addressed. In this work, a novel CuS/GeSe conductive-bridge threshold switching memristor is fabricated and singled out to realize electronic stochastic neurons, which is ascribed to the similarity between the stochastic switching behavior observed in the device and that of biological ion channels. The corresponding electric circuit of a stochastic neuron is then constructed and the probabilistic firing capacity of the neuron is utilized to implement Bayesian inference in a spiking neural network (SNN). The application prospects are demonstrated on the example of a tumor diagnosis task, where common fatal diagnostic errors of a conventional artificial neural network are successfully circumvented. Moreover, in comparison to deterministic neuron-based SNNs, the stochastic neurons enable SNNs to deliver an estimate of the uncertainty in their predictions, and the fidelity of the judgement is drastically improved by 81.2%.
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| 10. |
- Wang, Yu-Cheng, et al.
(författare)
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Porous Carbon Membrane-Supported Atomically Dispersed Pyrrole-Type Fe-N-4 as Active Sites for Electrochemical Hydrazine Oxidation Reaction
- 2020
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:31
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Tidskriftsartikel (refereegranskat)abstract
- The rational design of catalytically active sites in porous materials is essential in electrocatalysis. Herein, atomically dispersed Fe-N-x sites supported by hierarchically porous carbon membranes are designed to electrocatalyze the hydrazine oxidation reaction (HzOR), one of the key techniques in electrochemical nitrogen transformation. The high intrinsic catalytic activity of the Fe-N-x single-atom catalyst together with the uniquely mixed micro-/macroporous membrane support positions such an electrode among the best-known heteroatom-based carbon anodes for hydrazine fuel cells. Combined with advanced characterization techniques, electrochemical probe experiments, and density functional theory calculation, the pyrrole-type Fe-N-4 structure is identified as the real catalytic site in HzOR.
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| 11. |
- Xia, Li, et al.
(författare)
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Synergistic tailoring of band structure and charge carrier extraction in "€œgreen"€ core/shell quantum dots for highly efficient solar energy conversion
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 442:2
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Tidskriftsartikel (refereegranskat)abstract
- Environment-friendly colloidal core/shell quantum dots (QDs) with controllable optoelectronic characteristics are promising building blocks for future commercial solar technologies. Herein, we synergistically tailor the electronic band structure and charge carrier extraction of eco-friendly AgInS2 (AIS)/ZnS core/shell QDs via Mn-alloying and Cu-doping in the core and shell, respectively. It is demonstrated that the Mn-alloying in AIS core can broaden the band gap to facilitate delocalization of photogenerated electrons into the shell and further incorporation of Cu in the ZnS shell enables the creation of Cu-related states that capture the photogenerated holes from core, thus leading to charge carrier recombination and accelerated transfer of photogenerated electrons in the core/shell QDs. As-prepared Mn-AIS/ZnS@Cu QDs were assembled as light harvesters in a photoelectrochemical (PEC) device for light-driven hydrogen evolution, delivering a maximum photocurrent density of ∼6.4 mA cm-2 with superior device stability under standard one sun irradiation (AM 1.5G, 100 mW cm-2). Our findings highlight that simultaneously engineering the band alignment and charge carrier dynamics of “green†core/shell QDs endow the feasibility to design future high-efficiency and durable solar hydrogen production systems.
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| 12. |
- Xu, Weicheng, et al.
(författare)
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Nitrogen doping to accelerate the phase transition to ordered intermetallic Pt3Co catalyst for the oxygen reduction reaction in fuel cells
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 11:8, s. 4078-4087
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Tidskriftsartikel (refereegranskat)abstract
- Ordered intermetallic Pt–M alloys are foreseen to be promising as next-generation low-Pt catalysts for the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs) due to their high catalytic activity and stability. Nevertheless, the disorder-to-order intermetallic phase transition often needs to proceed at elevated annealing temperature for a long time, which leads to severe particle agglomeration. Herein, an efficient nitrogen (N)-doping strategy is developed to speed up such phase transition in an intermetallic Pt3Co alloy catalyst, which shortens the annealing duration by 3–5 fold at a temperature of 600–800 °C. Such a strategy can not only minimize the particle agglomeration but also effectively optimize the electronic structure of surface Pt atoms with the incorporated N. The prepared N-doped ordered intermetallic Pt3Co catalyst exhibits high ORR activity among the best of the state-of-the-art, with mass activities of 1.21 and 1.20 A mgPt−1 at 0.90 V in rotating disk electrode (RDE) and proton exchange membrane fuel cell (PEMFC) tests, respectively. Moreover, with the total Pt loading of 0.15 mgPt cm−2, the H2–air PEMFC delivers a power density of 1.27 W cm−2 at 150 kPaabs and 0.6 V, corresponding to a high Pt utilization of 0.118 gPt kW−1 that has surpassed the DOE 2025 target (0.125 gPt kW−1). This study paves a new way to develop high-performance low-Pt ORR catalysts for PEMFCs.
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| 13. |
- You, Xiaohu, et al.
(författare)
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Towards 6G wireless communication networks: vision, enabling technologies, and new paradigm shifts
- 2021
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Ingår i: Science China Information Sciences. - : Science Press. - 1674-733X .- 1869-1919. ; 64:1
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Forskningsöversikt (refereegranskat)abstract
- The fifth generation (5G) wireless communication networks are being deployed worldwide from 2020 and more capabilities are in the process of being standardized, such as mass connectivity, ultra-reliability, and guaranteed low latency. However, 5G will not meet all requirements of the future in 2030 and beyond, and sixth generation (6G) wireless communication networks are expected to provide global coverage, enhanced spectral/energy/cost efficiency, better intelligence level and security, etc. To meet these requirements, 6G networks will rely on new enabling technologies, i.e., air interface and transmission technologies and novel network architecture, such as waveform design, multiple access, channel coding schemes, multi-antenna technologies, network slicing, cell-free architecture, and cloud/fog/edge computing. Our vision on 6G is that it will have four new paradigm shifts. First, to satisfy the requirement of global coverage, 6G will not be limited to terrestrial communication networks, which will need to be complemented with non-terrestrial networks such as satellite and unmanned aerial vehicle (UAV) communication networks, thus achieving a space-air-ground-sea integrated communication network. Second, all spectra will be fully explored to further increase data rates and connection density, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands. Third, facing the big datasets generated by the use of extremely heterogeneous networks, diverse communication scenarios, large numbers of antennas, wide bandwidths, and new service requirements, 6G networks will enable a new range of smart applications with the aid of artificial intelligence (AI) and big data technologies. Fourth, network security will have to be strengthened when developing 6G networks. This article provides a comprehensive survey of recent advances and future trends in these four aspects. Clearly, 6G with additional technical requirements beyond those of 5G will enable faster and further communications to the extent that the boundary between physical and cyber worlds disappears.
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