| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
- Li, Shu, et al.
(författare)
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Comparative efficacy and safety of urate-lowering therapy for the treatment of hyperuricemia : a systematic review and network meta-analysis
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of hyperuricemia and gout has been increasing, but the comparative effectiveness and safety of different treatments remain uncertain. We aimed to compare the effectiveness and safety of different treatments for hyperuricemia using network meta-analysis methodology. We systematically reviewed fifteen randomized controlled trials (involving 7,246 patients through January 2016) that compared the effects of different urate-lowering drugs (allopurinol, benzbromarone, febuxostat, pegloticase and probenecid) on hyperuricemia. Drug efficacy and safety, as outcomes, were measured by whether the target level of serum urate acid was achieved and whether any adverse events occurred, respectively. We derived pooled effect sizes expressed as odds ratios (ORs) and 95% confidence intervals (CIs). The efficacy and safety of the drugs were ranked by cumulative ranking probabilities. Our findings show that febuxostat, benzbromarone, probenecid, pegloticase, and allopurinol were all highly effective at reducing the risk of hyperuricemia compared to placebo. Febuxostat had the best efficacy and safety compared to the other drugs. Furthermore, febuxostat 120 mg QD was more effective at achieving urate-lowering targets (OR: 0.17, 95% CI: 0.12-0.24) and safer (OR: 0.72, 95% CI: 0.56-0.91) than allopurinol.
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| 4. |
- Attané, Isabelle, et al.
(författare)
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Being a single man in rural China
- 2018
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Ingår i: Population and Societies. - 0184-7783. ; :557, s. 1-4
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Tidskriftsartikel (refereegranskat)abstract
- Those who are single in rural China are almost exclusively men. The presence of excess men in the population combines with internal migration and women's quest for upward social mobility through marriage to explain this phenomenon. The DefiChine survey sheds light on the situation of single men in three rural districts of Shaanxi. One of its findings is that, although the shortage of women does create competition between men looking for a wife, the social and economic dimensions of male singlehood cannot be ignored.
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| 5. |
- Brownstein, Catherine A., et al.
(författare)
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An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
- 2014
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 15:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. Results: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. Conclusions: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups.
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| 6. |
- Li, Weidong, et al.
(författare)
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Intelligent Optimisation for Integrated Process Planning and Scheduling
- 2011
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Ingår i: Multi-objective Evolutionary Optimisation for Product Design and Manufacturing. - London : Springer London. - 9780857296177 - 9780857296528 ; , s. 305-324
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Bokkapitel (refereegranskat)abstract
- Traditionally, process planning and scheduling were performed sequentially, where scheduling was executed after process plans had been generated. Considering the fact that the two functions are usually complementary, it is necessary to integrate them more tightly so that the performance of a manufacturing system can be improved greatly. In this chapter, a multi-agent-based framework has been developed to facilitate the integration of the two functions. In the framework, the two functions are carried out simultaneously, and an optimization agent based on evolutionary algorithms is used to manage the interactions and communications between agents to enable proper decisions to be made. To verify the feasibility and performance of the proposed approach, experimental studies conducted to compare this approach and some previous works are presented. The experimental results show the proposed approach has achieved significant improvement.
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| 7. |
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| 8. |
- Lu, Xin, et al.
(författare)
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A Generic Digital Twin Framework for Collaborative Supply Chain Development
- 2022
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Ingår i: 2022 5th International Conference on Computing and Big Data (ICCBD 2022). - : IEEE. - 9781665457163 - 9781665457156 - 9781665457170 ; , s. 177-181
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Konferensbidrag (refereegranskat)abstract
- Current Supply Chains (SCs) are complex and diverse along with fragile to SC disruptions. This leads urgently needs to develop an intelligent, transparent, collaborative and resilient SC system to cope with unexpected SC disruptions. Digital twin (DT) is one of the most promising solutions to develop smart SCs that has been extensively studied recent years. However, SCDT paradigm is still at an early stage. This paper presents a generic and modularized five layers DT framework to provide a flexible and collaborative solution, which can be compatible with different DT systems in various SCs. The feasibility of the proposed framework is validated through a practical implementation in a distributed eyewear industry.
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| 9. |
- Zhang, Liang, et al.
(författare)
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Deep Learning for Additive Screening in Perovskite Light-Emitting Diodes
- 2022
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 61:37
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Tidskriftsartikel (refereegranskat)abstract
- Additive engineering with organic molecules is of critical importance for achieving high-performance perovskite optoelectronic devices. However, experimentally finding suitable additives is costly and time consuming, while conventional machine learning (ML) is difficult to predict accurately due to the limited experimental data available in this relatively new field. Here, we demonstrate a deep learning method that can predict the effectiveness of additives in perovskite light-emitting diodes (PeLEDs) with a high accuracy up to 96 % by using a small dataset of 132 molecules. This model can maximize the information of the molecules and significantly mitigate the duplicated problem that usually happened with previous models in ML for molecular screening. Very high efficiency PeLEDs with a peak external quantum efficiency up to 22.7 % can be achieved by using the predicated additive. Our work opens a new avenue for further boosting the performance of perovskite optoelectronic devices.
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| 10. |
- Zhang, Wei, et al.
(författare)
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Thermal detection of surface plasmons on gold nanohole arrays
- 2012
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Ingår i: Chinese Science Bulletin. - : Springer Science and Business Media LLC. - 1001-6538 .- 1861-9541. ; 57:1, s. 68-71
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Tidskriftsartikel (refereegranskat)abstract
- We used a thin-film thermocouple to detect the thermal effect of surface plasmons excited in Au nanohole array structures. We found that the thermal electromotive force of Au film with periodic nanohole structures is three times greater than that of a bare Au film for 785-nm laser excitation at a given power. This effect is caused by the resonant excitation of localized surface plasmons in the nanoholes. In addition, we found that the thermal electromotive force (EMF) of the Au film with dumbbell-like nanohole arrays depends strongly on the incident polarization. The thermal EMF is the greatest when the excitation light is polarized perpendicular to the long axis of the dumbbell.
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| 11. |
- Zou, Yatao, et al.
(författare)
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Manipulating crystallization dynamics through chelating molecules for bright perovskite emitters
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Molecular additives are widely utilized to minimize non-radiative recombination in metal halide perovskite emitters due to their passivation effects from chemical bonds with ionic defects. However, a general and puzzling observation that can hardly be rationalized by passivation alone is that most of the molecular additives enabling high-efficiency perovskite light-emitting diodes (PeLEDs) are chelating (multidentate) molecules, while their respective monodentate counterparts receive limited attention. Here, we reveal the largely ignored yet critical role of the chelate effect on governing crystallization dynamics of perovskite emitters and mitigating trap-mediated non-radiative losses. Specifically, we discover that the chelate effect enhances lead-additive coordination affinity, enabling the formation of thermodynamically stable intermediate phases and inhibiting halide coordination-driven perovskite nucleation. The retarded perovskite nucleation and crystal growth are key to high crystal quality and thus efficient electroluminescence. Our work elucidates the full effects of molecular additives on PeLEDs by uncovering the chelate effect as an important feature within perovskite crystallization. As such, we open new prospects for the rationalized screening of highly effective molecular additives.
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| 12. |
- Zou, Yatao, et al.
(författare)
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Thermal-induced interface degradation in perovskite light-emitting diodes
- 2020
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Ingår i: Journal of Materials Chemistry C. - : ROYAL SOC CHEMISTRY. - 2050-7526 .- 2050-7534. ; 8:43, s. 15079-15085
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Tidskriftsartikel (refereegranskat)abstract
- Perovskite light-emitting diodes (PeLEDs) have experienced rapid improvements in device efficiency during the last several years. However, the operational instability of PeLEDs remains a key barrier hindering their practical applications. A fundamental understanding of the degradation mechanism is still lacking but will be important to seek ways to mitigate these unwanted processes. In this work, through comprehensive characterizations of the perovskite emitters and the interfacial contacts, we figure out that Joule heating induced interface degradation is one of the dominant factors affecting the operational stability of PeLEDs. We investigate the interfacial contacts of PeLEDs based on a commonly used device structure, with an organic electron transport layer of 1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene (TPBi), and observe obvious photoluminescence quenching of the perovskite layer after device operation. Detailed characterizations of the interlayers and the interfacial contacts reveal that photoluminescence quenching is mainly due to the element inter-diffusion at the interface induced by the morphological evolution of the TPBi layers under Joule heating during the operation of PeLEDs. Our work provides direct insights into the degradation pathways and highlights the importance of exploring intrinsically stable interlayers as well as interfacial contacts beyond the state-of-the-art to further boost the operational stability of PeLEDs.
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| 13. |
- Boyko, Andrey A., et al.
(författare)
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High-energy, narrowband, non-resonant PPKTP optical parametric oscillator
- 2022
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Ingår i: Nonlinear Frequency Generation and Conversion. - : SPIE - International Society for Optical Engineering.
-
Konferensbidrag (refereegranskat)abstract
- We present a narrowband, non-resonant optical parametric oscillator based on 5-mm thick Rb-doped periodically-poled KTiOPO4 (PPKTP) operating in the high-energy/low repetition-rate regime. An uncoated volume Bragg grating (VBG) is employed as one of the cavity mirrors reflecting only the signal whereas the other cavity mirror is reflecting only the idler. Pumping by a Nd:YAG laser at 1.0642 mu m in a double-pass, the signal plus idler output energy reached almost 5 mJ at a repetition rate of 100 Hz corresponding to a conversion efficiency of similar to 26%. Both signal and idler are narrowband with full width at half maximum (FWHM) of 0.5 nm at 1942 nm and 0.76 nm at 2355 nm, respectively.
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| 14. |
- Chen, Weidong, et al.
(författare)
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Narrowband BaGa2GeSe6 Optical Parametric Oscillator Pumped in an Intracavity Cascade Configuration
- 2023
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Ingår i: Proceedings - Optica Nonlinear Optics Topical Meeting 2023, NLO 2023. - : Optical Society of America.
-
Konferensbidrag (refereegranskat)abstract
- We present a tunable (6.62-11.34 µm), singly-resonant, cascade optical parametric oscillator with intracavity pumping of BaGa2GeSe6 in the second stage and spectral narrowing realized by a Volume Bragg Grating, providing millijoule output at 100 Hz.
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| 15. |
- Chen, Weidong, et al.
(författare)
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Narrowband, intracavity-pumped, type-II BaGa2GeSe6 optical parametric oscillator
- 2024
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Ingår i: Optics Express. - : Optica Publishing Group. - 1094-4087. ; 31:2, s. 1728-1735
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Tidskriftsartikel (refereegranskat)abstract
- We present a tunable (6.62-11.34 µm), singly-resonant, cascade optical parametric oscillator with intracavity pumping of BaGa2GeSe6 in the second stage and spectral narrowing realized by a Volume Bragg Grating acting on the signal wave of the first stage which serves as a pump for the second stage. The maximum energy achieved near 8 µm in the narrowband regime is 1.1 mJ at 100 Hz (spectral width: ∼20 cm−1, pulse duration: ∼7 ns). The overall conversion efficiency from 1 to 8 µm for broadband and narrowband operation is 4.0% and 3.1%, respectively, corresponding to quantum efficiencies of 31% and 23%.
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| 16. |
- Foley, Ryan J., et al.
(författare)
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THE FIRST MAXIMUM-LIGHT ULTRAVIOLET THROUGH NEAR-INFRARED SPECTRUM OF A TYPE Ia SUPERNOVA
- 2012
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Ingår i: THE ASTROPHYSICAL JOURNAL LETTERS. - 2041-8205. ; 753:1, s. L5-
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Tidskriftsartikel (refereegranskat)abstract
- We present the first maximum-light ultraviolet (UV) through near-infrared (NIR) Type Ia supernova (SN Ia) spectrum. This spectrum of SN 2011iv was obtained nearly simultaneously by the Hubble Space Telescope at UV/optical wavelengths and the Magellan Baade telescope at NIR wavelengths. These data provide the opportunity to examine the entire maximum-light SN Ia spectral energy distribution. Since the UV region of an SN Ia spectrum is extremely sensitive to the composition of the outer layers of the explosion, which are transparent at longer wavelengths, this unprecedented spectrum can provide strong constraints on the composition of the SN ejecta, and similarly the SN explosion and progenitor system. SN 2011iv is spectroscopically normal, but has a relatively fast decline (Delta m(15)(B) = 1.69 +/- 0.05 mag). We compare SN 2011iv to other SNe Ia with UV spectra near maximum light and examine trends between UV spectral properties, light-curve shape, and ejecta velocity. We tentatively find that SNe with similar light-curve shapes but different ejecta velocities have similar UV spectra, while those with similar ejecta velocities but different light-curve shapes have very different UV spectra. Through a comparison with explosion models, we find that both a solar-metallicity W7 and a zero-metallicity delayed-detonation model provide a reasonable fit to the spectrum of SN 2011iv from the UV to the NIR.
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| 17. |
- Fox, Ori D., et al.
(författare)
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UNCOVERING THE PUTATIVE B-STAR BINARY COMPANION OF THE SN 1993J PROGENITOR
- 2014
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Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 790:1, s. 17-
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Tidskriftsartikel (refereegranskat)abstract
- The Type IIb supernova (SN) 1993J is one of only a few stripped-envelope SNe with a progenitor star identified in pre-explosion images. SN IIb models typically invoke H envelope stripping by mass transfer in a binary system. For the case of SN 1993J, the models suggest that the companion grew to 22M(circle dot) and became a source of ultraviolet (UV) excess. Located in M81, at a distance of only 3.6 Mpc, SN 1993J offers one of the best opportunities to detect the putative companion and test the progenitor model. Previously published near-UV spectra in 2004 showed evidence for absorption lines consistent with a hot (B2 Ia) star, but the field was crowded and dominated by flux from the SN. Here we present Hubble Space Telescope Cosmic Origins Spectrograph and Wide-Field Camera 3 observations of SN 1993J from 2012, at which point the flux from the SN had faded sufficiently to potentially measure the UV continuum properties from the putative companion. The resulting UV spectrum is consistent with contributions from both a hot B star and the SN, although we cannot rule out line-of-sight coincidences.
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| 18. |
- Graves, Genevieve J. M., et al.
(författare)
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Limits from the Hubble Space Telescope on a Point Source in SN 1987A
- 2005
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 629, s. 944-959
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Tidskriftsartikel (refereegranskat)abstract
- We observed supernova 1987A (SN 1987A) with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) in 1999 September and again with the Advanced Camera for Surveys (ACS) on the HST in 2003 November. Our spectral observations cover ultraviolet (UV) and optical wavelengths from 1140 to 10266 Å, and our imaging observations cover UV and optical wavelengths from 2900 to 9650 Å. No point source is observed in the remnant. We obtain a limiting flux of Fopt<=1.6×10-14 ergs s-1 cm-2 in the wavelength range 2900-9650 Å for any continuum emitter at the center of the supernova remnant (SNR). This corresponds to an intrinsic luminosity of Lopt<=5×1033 ergs s-1. It is likely that the SNR contains opaque dust that absorbs UV and optical emission, resulting in an attenuation of ~35% due to dust absorption in the SNR. Correcting for this level of dust absorption would increase our upper limit on the luminosity of a continuum source by a factor of 1.54. Taking into account dust absorption in the remnant, we find a limit of Lopt<=8×1033 ergs s-1. We compare this upper bound with empirical evidence from point sources in other supernova remnants and with theoretical models for possible compact sources. We show that any survivor of a possible binary system must be no more luminous than an F6 main-sequence star. Bright young pulsars such as Kes 75 or the Crab pulsar are excluded by optical and X-ray limits on SN 1987A. Other nonplerionic X-ray point sources have luminosities similar to the limits on a point source in SN 1987A; RCW 103 and Cas A are slightly brighter than the limits on SN 1987A, while Pup A is slightly fainter. Of the young pulsars known to be associated with SNRs, those with ages <=5000 yr are all too bright in X-rays to be compatible with the limits on SN 1987A. Examining theoretical models for accretion onto a compact object, we find that spherical accretion onto a neutron star is firmly ruled out and that spherical accretion onto a black hole is possible only if there is a larger amount of dust absorption in the remnant than predicted. In the case of thin-disk accretion, our flux limit requires a small disk, no larger than 1010 cm, with an accretion rate no more than 0.3 times the Eddington accretion rate. Possible ways to hide a surviving compact object include the removal of all surrounding material at early times by a photon-driven wind, a small accretion disk, or very high levels of dust absorption in the remnant. It will not be easy to improve substantially on our optical-UV limit for a point source in SN 1987A, although we can hope that a better understanding of the thermal infrared emission will provide a more complete picture of the possible energy sources at the center of SN 1987A.
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| 19. |
- Hu, Kaixiong, et al.
(författare)
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CNN-BiLSTM enabled prediction on molten pool width for thin-walled part fabrication using Laser Directed Energy Deposition
- 2022
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Ingår i: JOURNAL OF MANUFACTURING PROCESSES. - : Elsevier BV. - 1526-6125. ; 78, s. 32-45
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Tidskriftsartikel (refereegranskat)abstract
- Laser Directed Energy Deposition (LDED) is a promising metal Additive Manufacturing (AM) technology capable of fabricating thin-walled parts to support some high-value applications. Accurate and efficient prediction on the molten pool width is critical to support in-situ control of LDED for part quality assurance. Nevertheless, owing to the intricate physical mechanisms of the process, it is challenging to designing an effective approach to accomplish the prediction target. To tackle the issue, in this research, a new data model-driven predictive approach, which is enabled by a hybrid machine learning model namely CNN-BiLSTM, is presented. High prediction accuracy and efficiency are achievable through innovative measures in the research, that is, (i) the CNN-BiLSTM model is designed and configured by addressing the characteristics of the LDED process; (ii) process parameters related to the deposition and heat accumulation phenomena during the LDED process are extensively considered to strengthen the prediction accuracy. Experiments for thin-walled part fabrication were conducted to validate and benchmark the approach. In average, 4.286% of the mean absolute percentage error (MAPE) was acquired, and the prediction time took by the approach was only 0.04% of that by a finite element analysis (FEA) approach. Compared to the LSTM model, the BiLSTM model and the CNN-LSTM model, MAPEs of the CNN-BiLSTM model were improved by 27.0%, 17.3% and 12.6%, respectively. It demonstrates that the approach is competent in producing good-quality thin-walled parts using the LDED process.
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| 20. |
- Huang, Zhiwen, et al.
(författare)
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Cross-domain tool wear condition monitoring via residual attention hybrid adaptation network
- 2024
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Ingår i: Journal of manufacturing systems. - : Elsevier BV. - 0278-6125 .- 1878-6642. ; 72, s. 406-423
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Tidskriftsartikel (refereegranskat)abstract
- Intelligent models for tool wear condition monitoring (TWCM) have been extensively researched. However, in industrial scenarios, limited acquired monitoring signals and variations of machining parameters lead to insufficient training samples and data distribution shifts for the models. To address the issues, this research presents a novel residual attention hybrid adaptation network (RAHAN) model based on a residual attention network (ResAttNet) and a hybrid adaptation strategy. In the RAHAN model, by integrating a channel attention mechanism and deep residual modules, ResAttNet is designed as a feature extractor to acquire features from monitoring signals for tool wear conditions. Embedding subdomain adaptation into a condition recognizer while establishing separate adversarial learning in a domain obfuscator, the hybrid adaptation strategy is developed to eliminate global distribution shifts and align local distributions of each tool wear phase simultaneously. Six migration tasks under a laboratory and two factory machining platforms were conducted to evaluate the effectiveness of the RAHAN model. Compared with a baseline model, four ablation models, and six state-of-the-art transfer learning models, the RAHAN model achieved the highest average accuracy of 92.70% on six migration tasks. Furthermore, the RAHAN model shows clearer feature representations of each tool wear condition than other compared models. The comparative results demonstrate that the RAHAN model has superior transferability and therefore can be considered as a good potential solution to support cross-domain TWCM under different machining processes.
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| 21. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy in higher eukaryotes
- 2008
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Ingår i: Autophagy. - : Landes Bioscience. - 1554-8627 .- 1554-8635. ; 4:2, s. 151-175
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Forskningsöversikt (refereegranskat)abstract
- Research in autophagy continues to accelerate,1 and as a result many new scientists are entering the field. Accordingly, it is important to establish a standard set of criteria for monitoring macroautophagy in different organisms. Recent reviews have described the range of assays that have been used for this purpose.2,3 There are many useful and convenient methods that can be used to monitor macroautophagy in yeast, but relatively few in other model systems, and there is much confusion regarding acceptable methods to measure macroautophagy in higher eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers of autophagosomes versus those that measure flux through the autophagy pathway; thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from fully functional autophagy that includes delivery to, and degradation within, lysosomes (in most higher eukaryotes) or the vacuole (in plants and fungi). Here, we present a set of guidelines for the selection and interpretation of the methods that can be used by investigators who are attempting to examine macroautophagy and related processes, as well as by reviewers who need to provide realistic and reasonable critiques of papers that investigate these processes. This set of guidelines is not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to verify an autophagic response.
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| 22. |
- Krisciunas, Kevin, et al.
(författare)
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THE MOST SLOWLY DECLINING TYPE Ia SUPERNOVA 2001ay
- 2011
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Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 142:3, s. 74-
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Tidskriftsartikel (refereegranskat)abstract
- We present optical and near-infrared photometry, as well as ground-based optical spectra and Hubble Space Telescope ultraviolet spectra, of the Type Ia supernova (SN) 2001ay. At maximum light the Si II and Mg II lines indicated expansion velocities of 14,000 km s-(1), while Si III and S II showed velocities of 9000 km s(-1). There is also evidence for some unburned carbon at 12,000 km s(-1). SN 2001ay exhibited a decline-rate parameter of Delta m(15)(B) = 0.68 +/- 0.05 mag; this and the B-band photometry at t greater than or similar to + 25 day past maximum make it the most slowly declining Type Ia SN yet discovered. Three of the four super-Chandrasekhar-mass candidates have decline rates almost as slow as this. After correction for Galactic and host-galaxy extinction, SN 2001ay had M(B) = -19.19 and M(V) = -19.17 mag at maximum light; thus, it was not overluminous in optical bands. In near-infrared bands it was overluminous only at the 2 sigma level at most. For a rise time of 18 days (explosion to bolometric maximum) the implied (56)Ni yield was (0.58 +/- 0.15)/alpha M(circle dot), with alpha = L(max)/E(Ni) probably in the range 1.0-1.2. The (56)Ni yield is comparable to that of many Type Ia SNe. The normal (56)Ni yield and the typical peak optical brightness suggest that the very broad optical light curve is explained by the trapping of gamma rays in the inner regions.
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| 23. |
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| 24. |
- Li, Weidong, et al.
(författare)
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An FFT processor based on 16-point module
- 2001
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Ingår i: Proc. NORCHIP'01. ; , s. 125-130
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Konferensbidrag (refereegranskat)abstract
- The number of multiplications has been a key merit for FFT algorithms. It has important impact on the total power consumption. In this paper, we present a 16-point FFT module, which reduc-es the multiplicative complexity by using real constant multiplications. A pipeline FFT proces-sor has been implemented with the 16-point module and simulation result shows that it is an attractive candidate to reduce the power consumption.
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| 25. |
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| 26. |
- Li, Weidong, et al.
(författare)
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Selective Disassembly Planning for Sustainable Management of Waste Electrical and Electronic Equipment
- 2013
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Ingår i: Re-engineering Manufacturing for Sustainability. - Singapore : Springer Singapore. ; , s. 341-346
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Konferensbidrag (refereegranskat)abstract
- Waste Electrical and Electronic Equipment (WEEE) are one of the most significant waste streams in modern societies. Full disassembly of WEEE is rarely an ideal solution due to high disassembly costs. Selective disassembly, which prioritizes operations for partial disassembly according to the legislative and economic considerations of specific stakeholders, is becoming an important yet still challenging research topic in recent years. In this paper, a Particle Swarm Optimization (PSO)-based selective disassembly planning method embedded with customizable decision-making models has been developed. The developed method is flexible to handle WEEE to meet the various requirements of stakeholders, and is capable to achieve optimized selective plans. Practical cases on Liquid Crystal Display (LCD) televisions have been used to verify and demonstrate the effectiveness of the research in application scenarios.
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| 27. |
- Li, Weidong, 1970-
(författare)
-
Studies on implementation of low power FFT processors
- 2003
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the last decade, the interest for high speed wireless and on cable communication has increased. Orthogonal Frequency Division Multiplexing (OFDM) is a strong candidates and has been suggested or standardized in those communication systems. One key component in OFDM-based systems is FFT processor, which performs the efficient modulation/demodulation.There are many FFT architectures. Among them, the pipeline architectures are suitable for the real-time communication systems. This thesis presents the implementation of pipeline FFT processors that has low power consumptions.We select the meet-in-the-middle design methodology for the implementation of FFT processors. A resource analysis for the pipeline architectures is presented. This resource analysis determines the number of memories, butterflies, and complex multipliers to meet the specification.We present a wordlengths optimization method for the pipeline architectures. We show that the high radix butterfly can be efficiently implemented with carry-save technique, which reduce the hardware complexity and the delay. We present also an efficient implementation of complex multiplier using distributed arithmetic (DA). The implementation of low voltage memories is also discussed.Finally, we present a 16-point butterfly using constant multipliers that reduces the total number of complex multiplications. The FFT processor using the 16-point butterflies is a competitive candidate for low power applications.
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| 28. |
- Li, Xiangdong A., et al.
(författare)
-
Design and Evaluation of Cross-Objects User Interface for Whiteboard Interaction
- 2017
-
Ingår i: Distributed, Ambient and Pervasive Interactions. - Cham : Springer. - 9783319586960 - 9783319586977 ; , s. 180-191
-
Konferensbidrag (refereegranskat)abstract
- Whiteboard has long been an important tool for education and communication, and nowadays it embraces display functions and other interactive features such as pen pointing and selecting of digital contents. Despite the enhanced interactivity, it is often time- and cost-consuming to implement specific apparatus for different whiteboard interactions. Therefore, we aimed at incorporating physical-world objects (e.g. Lego Rubik’s cubes) as the cross-objects user interface for multiple whiteboard interaction tasks without incurring heavy development work. The user interface utilised electromagnetic technique to extract electromechanical signals and recognised normal objects, thus extended the generality. To further understand effectiveness of the user interface, we implemented a low-fidelity prototype and conducted within-subject evaluation. The results showed the cross-objects user interface was natural, responsive, and easy of learning as the conventional whiteboard. Moreover, the user interface outperformed over the conventional one in the perspectives of configuration efficiency and versatility of multiple interaction tasks. Given these findings, practical implications for future tangible user interface design for whiteboard interactions are discussed.
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| 29. |
- Li, Xiangdong, et al.
(författare)
-
Towards personalized virtual reality touring through cross-object user interfaces
- 2019
-
Ingår i: Personalized Human-Computer Interaction. - : Walter de Gruyter. - 9783110552485 ; , s. 201-222
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Real-time adaptation is one of the most important problems that currently require a solution in the field of personalized human-computer interaction. For conventional desktop system interactions, user behaviors are acquired to develop models that support context-aware interactions. In virtual reality interactions, however, users operate tools in the physical world but view virtual objects in the virtual world. This dichotomy constrains the use of conventional behavioral models and presents difficulties to personalizing interactions in virtual environments. To address this problem, we propose the cross-object user interfaces (COUIs) for personalized virtual reality touring. COUIs consist of two components: a Deep Learning algorithm-based model using convolutional neural networks (CNNs) to predict the user’s visual attention from the past eye movement patterns to determine which virtual objects are likely to be viewed next, and delivery mechanisms that determine what should when and where be displayed on the user interface. In this chapter, we elaborate on the training and testing of the prediction model and evaluate the delivery mechanisms of COUIs through a cognitive walk-through approach. Furthermore, the implications for using COUIs to personalize interactions in virtual reality (and other environments such as augmented reality and mixed reality) are discussed.
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| 30. |
- Li, Yuangui, et al.
(författare)
-
A new method to construct reduced vector sets for simplifying support vector machines
- 2006
-
Ingår i: IEEE International Conference on Engineering of Intelligent Systems. - Piscataway, NJ : IEEE Communications Society. - 1424404568
-
Konferensbidrag (refereegranskat)abstract
- Support vector machines (SVM) are well known to give good results on pattern recognition problems, but for large scale problems, they exhibit substantially slower classification speeds than neural networks. It has been proposed to speed the SVM classification by approximating the decision function of SVM with a reduced vector set. A new method to construct the reduced vector set is proposed in this paper, which is constructed by merging the closest support vectors in an iterative fashion. A minor modification on the proposed method also has been made in order to simplify the decision function of reduced support vector machines (RSVM). The proposed method was compared with previous study on several benchmark data sets, and the computational results indicated that our method could simplify SVMs and RSVMs effectively, which will speed the classification for large scale problems
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| 31. |
- Li, Yuangui, et al.
(författare)
-
Improved sparse least-squares support vector machine classifiers
- 2006
-
Ingår i: Neurocomputing. - : Elsevier BV. - 0925-2312 .- 1872-8286. ; 69:13-15, s. 1655-1658
-
Tidskriftsartikel (refereegranskat)abstract
- The least-squares support vector machines (LS-SVM) can be obtained by solving a simpler optimization problem than that in standard support vector machines (SVM). Its shortcoming is the loss of sparseness and this usually results in slow testing speed. Several pruning methods have been proposed. It is found that these methods can be further improved for classification problems. In this paper a different reduced training set is selected to re-train LS-SVM. Then a new procedure is proposed to obtain the sparseness. The performance of the proposed method is compared with other typical ones and the results indicate that it is more effective.
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| 32. |
- Luo, Xiyu, et al.
(författare)
-
Effects of local compositional heterogeneity in mixed halide perovskites on blue electroluminescence
- 2024
-
Ingår i: Matter. - 2590-2393. ; 7:3, s. 1054-1070
-
Tidskriftsartikel (refereegranskat)abstract
- Compositional heterogeneity is commonly observed in mixed bromide/iodide perovskite photoabsorbers, typically with minimal effects on charge carrier recombination and photovoltaic performance. Consistently, it has so far received very limited attention in bromide/chloride-mixed perovskites, which hold particular significance for blue light-emitting diodes. Here, we uncover that even a minor degree of localized halide heterogeneity leads to severe non-radiative losses in mixed bromide/chloride blue perovskite emitters, presenting a stark contrast to general observations in photovoltaics. We not only provide a visualization of the heterogeneity landscape spanning from micro-to sub-microscale but also identify that this issue mainly arises from the initially formed chloride-rich clusters during perovskite nucleation. Our work sheds light on a long-term neglected factor impeding the advancement of blue light-emitting diodes using mixed halide perovskites and provides a practical strategy to mitigate this issue.
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| 33. |
- McCully, Curtis, et al.
(författare)
-
HUBBLE SPACE TELESCOPE AND GROUND-BASED OBSERVATIONS OF THE TYPE Iax SUPERNOVAE SN 2005hk AND SN 2008A
- 2014
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 786:2, s. 134-
-
Tidskriftsartikel (refereegranskat)abstract
- We present Hubble Space Telescope (HST) and ground-based optical and near-infrared observations of SN 2005hk and SN 2008A, typical members of the Type Iax class of supernovae (SNe). Here we focus on late-time observations, where these objects deviate most dramatically from all other SN types. Instead of the dominant nebular emission lines that are observed in other SNe at late phases, spectra of SNe 2005hk and 2008A show lines of Fe II, Ca II, and Fe I more than a year past maximum light, along with narrow [ Fe II] and [ Ca II] emission. We use spectral features to constrain the temperature and density of the ejecta, and find high densities at late times, with n(e) greater than or similar to 10(9) cm(-3). Such high densities should yield enhanced cooling of the ejecta, making these objects good candidates to observe the expected infrared catastrophe, a generic feature of SN Ia models. However, our HST photometry of SN 2008A does not match the predictions of an infrared catastrophe. Moreover, our HST observations rule out a complete deflagration that fully disrupts the white dwarf for these peculiar SNe, showing no evidence for unburned material at late times. Deflagration explosion models that leave behind a bound remnant can match some of the observed properties of SNe Iax, but no published model is consistent with all of our observations of SNe 2005hk and 2008A.
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| 34. |
- Menon, Vinod, et al.
(författare)
-
Microstructural organization of human insula is linked to its macrofunctional circuitry and predicts cognitive control
- 2020
-
Ingår i: eLife. - : eLife Sciences Publications, Ltd. - 2050-084X. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- The human insular cortex is a heterogeneous brain structure which plays an integrative role in guiding behavior. The cytoarchitectonic organization of the human insula has been investigated over the last century using postmortem brains but there has been little progress in noninvasive in vivo mapping of its microstructure and large-scale functional circuitry. Quantitative modeling of multi-shell diffusion MRI data from 413 participants revealed that human insula microstructure differs significantly across subdivisions that serve distinct cognitive and affective functions. Insular microstructural organization was mirrored in its functionally interconnected circuits with the anterior cingulate cortex that anchors the salience network, a system important for adaptive switching of cognitive control systems. Furthermore, insular microstructural features, confirmed in Macaca mulatta, were linked to behavior and predicted individual differences in cognitive control ability. Our findings open new possibilities for probing psychiatric and neurological disorders impacted by insular cortex dysfunction, including autism, schizophrenia, and fronto-temporal dementia.
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| 35. |
- Michael, Eli, et al.
(författare)
-
Hubble Space Telescope Observations of High-Velocity Lyα and Hα Emission from Supernova Remnant 1987A : The Structure and Development of the Reverse Shock
- 2003
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 593, s. 809-830
-
Tidskriftsartikel (refereegranskat)abstract
- We present two-dimensional line profiles of high-velocity (~+/-12,000 km s-1) Lyα and Hα emission from supernova remnant 1987A obtained with the Space Telescope Imaging Spectrograph between 1997 September and 2001 September (days 3869-5327 after the explosion). This emission comes from hydrogen in the debris that is excited and ionized as it passes through the remnant's reverse shock. We use these profiles to measure the geometry and development of the reverse-shock surface. The observed emission is confined within ~+/-30° about the remnant's equatorial plane. At the equator, the reverse shock has a radius of ~75% of the distance to the equatorial ring. We detect marginal differences (6%+/-3%) between the location of the reverse-shock front in the northeast and southwest parts of the remnant. The radius of the reverse shock surface increases for latitudes above the equator, a geometry consistent with a model in which the supernova debris expands into a bipolar nebula. Assuming that the outer supernova debris has a power-law density distribution, we can infer from the reverse-shock emission light curve an expansion rate (in the northeast part of the remnant) of 3700+/-900kms-1, consistent with the expansion velocities determined from observations in radio (Manchester et al.) and X-ray (Park et al.; Michael et al.) wavelengths. However, our most recent observation (at day 5327) suggests that the rate of increase of mass flux across the northeast sector of the reverse shock has accelerated, perhaps because of deceleration of the reverse shock caused by the arrival of a reflected shock created when the blast wave struck the inner ring. Resonant scattering within the supernova debris causes Lyα photons created at the reverse shock to be directed preferentially outward, resulting in a factor of ~5 difference in the observed brightness of the reverse shock in Lyα between the near and far sides of the remnant. Accounting for this effect, we compare the observed reverse-shock Lyα and Hα fluxes to infer the amount of interstellar extinction by dust as E(B-V)=0.17+/-0.01 mag. We also notice extinction by dust in the equatorial ring with E(B-V)~0.02-0.08 mag, which implies dust-to-gas ratios similar to that of the LMC. Since Hα photons are optically thin to scattering, the observed asymmetry in brightness of Hα from the near and far sides of the remnant represents a real asymmetry in the mass flux through the reverse shock of ~30%. We discuss future observational strategies that will permit us to further investigate the reverse-shock dynamics and resonant scattering of the Lyα line and to constrain better the extinction by dust within and in front of the remnant.
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| 36. |
|
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| 37. |
- Simon, Joshua D., et al.
(författare)
-
Variable Sodium Absorption in a Low-extinction Type Ia Supernova
- 2009
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 702, s. 1157-1170
-
Tidskriftsartikel (refereegranskat)abstract
- Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the progenitor system prior to the explosion, with significant implications for the nature of the supernova (SN) progenitors. We present the third detection of such variable absorption, based on six epochs of high-resolution spectroscopy of the Type Ia supernova SN 2007le from the Keck I Telescope and the Hobby-Eberly Telescope. The data span a time frame of approximately three months, from 5 days before maximum light to 90 days after maximum. We find that one component of the Na I D absorption lines strengthened significantly with time, indicating a total column density increase of ~2.5 × 1012 cm-2. The data limit the typical timescale for the variability to be more than 2 days but less than 10 days. The changes appear to be most prominent after maximum light rather than at earlier times when the ultraviolet flux from the SN peaks. As with SN 2006X, we detect no change in the Ca II H and K absorption lines over the same time period, rendering line-of-sight effects improbable and suggesting a circumstellar origin for the absorbing material. Unlike the previous two supernovae exhibiting variable absorption, SN 2007le is not highly reddened (E B - V = 0.27 mag), also pointing toward circumstellar rather than interstellar absorption. Photoionization calculations show that the data are consistent with a dense (107 cm-3) cloud or clouds of gas located ~0.1 pc (3 × 1017 cm) from the explosion. These results broadly support the single-degenerate scenario previously proposed to explain the variable absorption, with mass loss from a nondegenerate companion star responsible for providing the circumstellar gas. We also present possible evidence for narrow Hα emission associated with the SN, which will require deep imaging and spectroscopy at late times to confirm. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and NASA. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Based in part on observations obtained with the Hobby-Eberly Telescope, which is a joint project of the University of Texas at Austin, the Pennsylvania State University, Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Universität Göttingen.
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| 38. |
- Stritzinger, Maximilian, et al.
(författare)
-
THE CARNEGIE SUPERNOVA PROJECT : SECOND PHOTOMETRY DATA RELEASE OF LOW-REDSHIFT TYPE Ia SUPERNOVAE
- 2011
-
Ingår i: Astronomical Journal. - : American Astronomical Society. - 0004-6256 .- 1538-3881. ; 142:5, s. 156-
-
Tidskriftsartikel (refereegranskat)abstract
- The Carnegie Supernova Project (CSP) was a five-year observational survey conducted at Las Campanas Observatory that obtained, among other things, high-quality light curves of similar to 100 low-redshift Type Ia supernovae (SNe Ia). Presented here is the second data release of nearby SN Ia photometry consisting of 50 objects, with a subset of 45 having near-infrared follow-up observations. Thirty-three objects have optical pre-maximum coverage with a subset of 15 beginning at least five days before maximum light. In the near-infrared, 27 objects have coverage beginning before the epoch of B-band maximum, with a subset of 13 beginning at least five days before maximum. In addition, we present results of a photometric calibration program to measure the CSP optical (uBgVri) bandpasses with an accuracy of similar to 1%. Finally, we report the discovery of a second SN Ia, SN 2006ot, similar in its characteristics to the peculiar SN 2006bt.
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| 39. |
- Sun, Lingyun, et al.
(författare)
-
Cross-objects user interfaces for video interaction in virtual reality museum context
- 2018
-
Ingår i: Multimedia tools and applications. - : Springer Science and Business Media LLC. - 1380-7501 .- 1573-7721. ; 77:21, s. 29013-29041
-
Tidskriftsartikel (refereegranskat)abstract
- Museums are good places for learning and nowadays many museums are integrating digital media such as video and increasingly moving towards using virtual reality. In the physical world people used to seek information from object surfaces e.g. posters on the wall and this has been used as a metaphor in the virtual reality museum: numerous videos were inhabited within virtual objects and shaped cross-objects user interfaces (COUIs). However, how such interfaces perform for video interactions still needs more investigations. In this study we implemented and investigated COUIs in comparison with the conventional card-style user interfaces and the plain virtual reality user interfaces in the virtual reality museum. The results reported no significant differences in the perceived usability or learning experience between these user interfaces, except the COUIs had a lower level of satisfaction than the card-style user interfaces. However, the COUIs showed greater efficiency with shorter eye fixation durations and higher saccade frequencies, and within these COUIs instances, namely the fully-detached, semi-attached, and fully-attached COUIs, the fully-attached instance was closest to the form of interacting with physical object surfaces and it reported highest efficiency as well. Rationales behind these results and implications generalising for the future design of COUIs, are discussed.
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| 40. |
- Wang, Chuanfei, et al.
(författare)
-
Organic Semiconductor Interfaces and Their Effects in Organic Solar Cells
- 2023
-
Ingår i: Chinese journal of chemistry. - : WILEY-V C H VERLAG GMBH. - 1001-604X .- 1614-7065.
-
Forskningsöversikt (refereegranskat)abstract
- Energy levels and energy level alignment at interfaces play a decisive role in designing efficient and stable organic solar cells (OSCs). In this review two usually used technologies in organic photovoltaic communities for measuring energy levels of organic semiconductors, photoelectron spectroscopy and electrochemical methods, are introduced, and the relationships between the values obtained from the corresponding techniques are compared. The energy level and energy level alignment across the interfaces involved in solution processed organic photovoltaics are described, and the corresponding integer charge transfer model for predicting and explaining energy level alignment is presented. The effects of the interface properties in designing efficient binary and ternary OSCs were discussed. The effects of environmental factors mainly including water vapor, oxygen gas and thermal annealing on energy levels and energy level alignment involved in photoactive layers, and the subsequent effects on the corresponding OSC properties are given.
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| 41. |
- Wang, Hao, et al.
(författare)
-
In-situ growth of low-dimensional perovskite-based insular nanocrystals for highly efficient light emitting diodes
- 2023
-
Ingår i: Light. - : SPRINGERNATURE. - 2095-5545 .- 2047-7538. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Regulation of perovskite growth plays a critical role in the development of high-performance optoelectronic devices. However, judicious control of the grain growth for perovskite light emitting diodes is elusive due to its multiple requirements in terms of morphology, composition, and defect. Herein, we demonstrate a supramolecular dynamic coordination strategy to regulate perovskite crystallization. The combined use of crown ether and sodium trifluoroacetate can coordinate with A site and B site cations in ABX(3) perovskite, respectively. The formation of supramolecular structure retard perovskite nucleation, while the transformation of supramolecular intermediate structure enables the release of components for slow perovskite growth. This judicious control enables a segmented growth, inducing the growth of insular nanocrystal consist of low-dimensional structure. Light emitting diode based on this perovskite film eventually brings a peak external quantum efficiency up to 23.9%, ranking among the highest efficiency achieved. The homogeneous nano-island structure also enables high-efficiency large area (1 cm(2)) device up to 21.6%, and a record high value of 13.6% for highly semi-transparent ones.
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| 42. |
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| 43. |
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| 44. |
- Wang, Li, et al.
(författare)
-
Spectral Narrowing of a Non-Resonant PPKTP Optical Parametric Oscillator using a VBG
- 2023
-
Ingår i: CLEO: Applications and Technology, CLEO:A and T 2023. - : Optica Publishing Group.
-
Konferensbidrag (refereegranskat)abstract
- A non-resonant optical parametric oscillator based on 5-mm-thicii Rb-doped periodically-poled KTÌOPO4 (PPKTP) generates narrow-band (<1-nm) idler pulses of 5.84-ITIJ energy at -2382 nm and 100 Hz using a volume Bragg grating for the signal wave.
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| 45. |
- Wang, Xiaofeng, et al.
(författare)
-
Evidence for type ia supernova diversity from ultraviolet observations with the hubble space telescope
- 2012
-
Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 749:2, s. 126-
-
Tidskriftsartikel (refereegranskat)abstract
- We present ultraviolet (UV) spectroscopy and photometry of four Type Ia supernovae (SNe 2004dt, 2004ef, 2005M, and 2005cf) obtained with the UV prism of the Advanced Camera for Surveys on the Hubble Space Telescope. This data set provides unique spectral time series down to 2000 angstrom. Significant diversity is seen in the near-maximum-light spectra (similar to 2000-3500 angstrom) for this small sample. The corresponding photometric data, together with archival data from Swift Ultraviolet/Optical Telescope observations, provide further evidence of increased dispersion in the UV emission with respect to the optical. The peak luminositiesmeasured in the uvw1/F250W filter are found to correlate with the B-band light-curve shape parameter Delta m(15)(B), but with much larger scatter relative to the correlation in the broadband B band (e.g., similar to 0.4 mag versus similar to 0.2 mag for those with 0.8 mag < Delta m(15)(B) < 1.7 mag). SN 2004dt is found as an outlier of this correlation (at > 3 sigma), being brighter than normal SNe Ia such as SN 2005cf by similar to 0.9 mag and similar to 2.0 mag in the uvw1/F250W and uvm2/F220W filters, respectively. We show that different progenitor metallicity or line-expansion velocities alone cannot explain such a large discrepancy. Viewing-angle effects, such as due to an asymmetric explosion, may have a significant influence on the flux emitted in the UV region. Detailed modeling is needed to disentangle and quantify the above effects.
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| 46. |
- Wang, Yanghui, et al.
(författare)
-
Prediction of melt pool width and layer height for Laser Directed Energy Deposition enabled by physics-driven temporal convolutional network
- 2023
-
Ingår i: Journal of manufacturing systems. - : Elsevier BV. - 0278-6125 .- 1878-6642. ; 69, s. 1-17
-
Tidskriftsartikel (refereegranskat)abstract
- Laser Directed Energy Deposition (L-DED) is a momentous metal additive manufacturing technology. Owing to high flexibility characteristic, it has been progressively adopted by high-value manufacturing industries. For the technology, one of the fundamental research challenges is how to accurately predict the melt pool size to ensure high-quality L-DED processes. To tackle the challenge, a novel physics-driven temporal convolutional network (TCN) approach is presented. In this research, the high prediction accuracy for L-DED is achievable via the following innovations: (i) a TCN model is designed as the core of the approach to leveraging the distinctive characteristics of the TCN model to address the temporal nature of the L-DED process during heat accumulation and incremental deposition; (ii) the physical models of the peak temperature, Marangoni effect and liquid jets affecting the melt pool formulization during the L-DED process are specified to strengthen the prediction accuracy of the approach. Experiments for manufacturing thin-walled parts using L-DED were conducted for approach validation and analyses. On average, the mean absolute percentage errors (MAPEs) of predicting the melt pool width and the layer height of a melt pool attained by this approach are 3.421% and 4.643%, respectively. The experiments demonstrate that the approach is competent to support the L-DED process in producing good-quality thin-walled parts.
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| 47. |
- Wassermann, Demian, et al.
(författare)
-
Sensing Spindle Neurons in the Insula with Multi-shell Diffusion MRI
- 2018
-
Konferensbidrag (refereegranskat)abstract
- Sensing microstructural characteristics of human brain tissue with clinical scanners has been an area of heated debate in the diffusion MRI (dMRI) community. In this work, we propose that diffusion MRI on clinical scanners is sensitive to the presence of spindle neurons.Spindle neurons, located in the insular and anterior cingular cortices, are only present in mammals with high cognitive functions. Albeit this neurons' role is not yet known, evidence suggests they facilitate rapid long-range information integration.In this work, we provide theoretical and in-silico evidence that the dMRI signal is sensitive to the presence of spindle neurons as well as preliminary evidence on human dMRI images.
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| 48. |
- Weidong, Wang, et al.
(författare)
-
Numerical Evaluation on a Direct-contact Thermal Energy Storage System
- 2017
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 105, s. 4389-4394
-
Tidskriftsartikel (refereegranskat)abstract
- This study evaluates numerically various configurations of direct-contact PCM thermal energy storage devices, regarding inlet location, inlet flow directions, pre-heating and inlet tubes with straight fins. The direct-contact conjugate heat transfer between the heat transfer fluid (HTF) and PCM during melting process, is solved numerically by enthalpy-porosity formulation in the computational fluid dynamic approach. The results indicate that pre-heating could form channels in a short time, which improve heat transfer rate for charging stages. To further enhance heat transfer performance, inlet tubes embedded with straight fins. Compared to pre-heating method, the electric power can be saved. Each design are evaluated with respect to their heat transfer performance vis-à-vis heat storage ratio.
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| 49. |
- Xiang, Yusen, et al.
(författare)
-
Ginkgolic acids inhibit SARS-CoV-2 and its variants by blocking the spike protein/ACE2 interplay
- 2023
-
Ingår i: International Journal of Biological Macromolecules. - : Elsevier. - 0141-8130 .- 1879-0003. ; 226, s. 780-792
-
Tidskriftsartikel (refereegranskat)abstract
- Targeting the interaction between the spike protein receptor binding domain (S-RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and angiotensin-converting enzyme 2 (ACE2) is a potential therapeutic strategy for treating coronavirus disease 2019 (COVID-19). However, we still lack small-molecule drug candidates for this target due to the missing knowledge in the hot spots for the protein-protein interaction. Here, we used NanoBiT technology to identify three Ginkgolic acids from an in-house traditional Chinese medicine (TCM) library, and they interfere with the S-RBD/ACE2 interplay. Our pseudovirus assay showed that one of the compounds, Ginkgolic acid C17:1 (GA171), significantly inhibits the entry of original SARS-CoV-2 and its variants into the ACE2-overexpressed HEK293T cells. We investigated and proposed the binding sites of GA171 on S-RBD by combining molecular docking and molecular dynamics simulations. Site-directed mutagenesis and surface plasmon resonance revealed that GA171 specifically binds to the pocket near R403 and Y505, critical residues of S-RBD for S-RBD interacting with ACE2. Thus, we provide structural insights into developing new small-molecule inhibitors and vaccines against the proposed S-RBD binding site.
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| 50. |
- Xu, Weidong, 1988-, et al.
(författare)
-
Rational molecular passivation for high-performance perovskite light-emitting diodes
- 2019
-
Ingår i: Nature Photonics. - : Springer Nature Publishing AG. - 1749-4885 .- 1749-4893. ; 13:6, s. 418-424
-
Tidskriftsartikel (refereegranskat)abstract
- A major efficiency limit for solution-processed perovskite optoelectronic devices, for example light-emitting diodes, is trap-mediated non-radiative losses. Defect passivation using organic molecules has been identified as an attractive approach to tackle this issue. However, implementation of this approach has been hindered by a lack of deep understanding of how the molecular structures influence the effectiveness of passivation. We show that the so far largely ignored hydrogen bonds play a critical role in affecting the passivation. By weakening the hydrogen bonding between the passivating functional moieties and the organic cation featuring in the perovskite, we significantly enhance the interaction with defect sites and minimize non-radiative recombination losses. Consequently, we achieve exceptionally high-performance near-infrared perovskite light-emitting diodes with a record external quantum efficiency of 21.6%. In addition, our passivated perovskite light-emitting diodes maintain a high external quantum efficiency of 20.1% and a wall-plug efficiency of 11.0% at a high current density of 200 mA cm−2, making them more attractive than the most efficient organic and quantum-dot light-emitting diodes at high excitations.
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