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1.
  • Ablikim, M., et al. (author)
  • First measurement of e(+)e(-) -> pK(S)(0)(n)over-barK(-) + c.c. above open charm threshold
  • 2018
  • In: Physical Review D. - 2470-0010 .- 2470-0029. ; 98:3
  • Journal article (peer-reviewed)abstract
    • The process e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. and its intermediate processes are studied for the first time, using data samples collected with the BESIII detector at BEPCII at center-of-mass energies of 3.773, 4.008, 4.226, 4.258, 4.358, 4.416, and 4.600 GeV, with a total integrated luminosity of 7.4 fb(-1). The Born cross section of e(+)e(-) -> pK(S)(0)(n) over barK(-) + c.c. is measured at each center-of-mass energy, but no significant resonant structure in the measured cross-section line shape between 3.773 and 4.600 GeV is observed. No evident structure is detected in the pK(-), nK(S)(0), pK(S)(0), nK(+), p (n) over bar, or (KSK-)-K-0 invariant mass distributions except for Lambda(1520). The Born cross sections of e(+)e(-) -> Lambda(1520)(n) over barK(S)(0) + c.c. and e(+)e(-) -> Lambda(1520)(p) over barK(+) + c.c. are measured, and the 90% confidence level upper limits on the Born cross sections of e(+)e(-) -> Lambda(1520)(Lambda) over bar (1520) are determined at the seven center-of-mass energies. There is an evident difference in line shape and magnitude of the measured cross sections between e(+)e(-) -> Lambda(1520)(-> pK(-))(n) over barK(S)(0) and e(+)e(-) -> pK-(Lambda) over bar (1520)(-> (n) over barK(S)(0)).
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2.
  • Ablikim, M., et al. (author)
  • Observation of psi(3686) -> eta ' e(+)e(-)
  • 2018
  • In: Physics Letters B. - : ELSEVIER SCIENCE BV. - 0370-2693 .- 1873-2445. ; 783, s. 452-458
  • Journal article (peer-reviewed)abstract
    • Using a data sample of 448.1 x 10(6) psi(3686) events collected with the BESIII detector at the BEPCII collider, we report the first observation of the electromagnetic Dalitz decay psi(3686) -> eta'e(+)e(-), with significances of 7.0 sigma and 6.3 sigma when reconstructing the eta' meson via its decay modes eta' -> gamma pi(+)pi(-) and eta' -> pi(+)pi(-) eta (eta -> gamma gamma), respectively. The weighted average branching fraction is determined to be B(psi(3686) -> eta'e(+)e(-)) = (1.90 +/- 0.25 +/- 0.11) x 10(-6), where the first uncertainty is statistical and the second systematic.
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3.
  • Ablikim, M., et al. (author)
  • Observation of the Semileptonic Decay D-0 -> a(0)(980)(-)e(+)nu(e) and Evidence for D+ -> a(0)(980)(0)e(+)nu(e)
  • 2018
  • In: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 121:8
  • Journal article (peer-reviewed)abstract
    • Using an e(+)e(-) collision data sample of 2.93 fb(-1) collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D-0 -> a(0)(980)(-)e(+)nu(e) and evidence for D+ -> a(0)(980)(0)e(+)nu(e) with significances of 6.4 sigma and 2.9 sigma, respectively. The absolute branching fractions are determined to be B(D-0 -> a(0)(980)(-)e(+)nu(e)) x B(a(0)(980)(-) -> eta pi(-)) = [1.33(-0.29)(+0.33)(stat) +/- 0.09(syst)] x 10(-4) and B(D+ -> a(0)(980)(0)e(+)nu(e)) x B(a(0)(980)(0) -> eta pi(0)) = [1.66(-0.66)(+0.81)(stat) +/- 0.11(syst) x 10(-4). This is the first time the a(0)(980) meson has been measured in a D-0 semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a(0)(980) states.
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4.
  • Ablikim, M., et al. (author)
  • Search for invisible decays of omega and phi with J/psi data at BESIII
  • 2018
  • In: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 98:3
  • Journal article (peer-reviewed)abstract
    • Using a data sample of (1310.6 +/- 7.0) x 10(6) J/psi events collected with the BESIII detector operating at the BEPCII collider, we perform the first experimental search for invisible decays of a light vector meson (V = omega, phi) via J/psi -> V-eta decays. The decay of eta -> pi(+)pi(-)pi(0) is utilized to tag the V meson decaying into the invisible final state. No evidence for a significant invisible signal is observed, and the upper limits on the ratio of branching fractions at the 90% confidence level are determined to be B(omega -> invisible)/B(omega -> pi(+)pi(-)pi(0)) < 8.1 x 10(-5) and B(phi -> invisible)/B(phi -> K+K-) < 3.4 x 10(-4). By using the world average values of B(omega -> pi(+)pi(-)pi(0) and B(phi -> K+K-,) the upper limits on the decay branching fractions at the 90% confidence level are set as B(omega -> invisible) < 7.3 x 10(-5) and B(phi -> invisible) < 1.7 x 10(-4), respectively.
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5.
  • Ablikim, M., et al. (author)
  • Search for the rare decays D -> h(h((')))e(+) e(-)
  • 2018
  • In: Physical Review D. - : AMER PHYSICAL SOC. - 2470-0010 .- 2470-0029. ; 97:7
  • Journal article (peer-reviewed)abstract
    • We search for rare decays of D mesons to hadrons accompanied by an electron-positron pair (h(h((')))e(+)e(- )),using an e(+)e(-) collision sample corresponding to an integrated luminosity of 2.93 fb(-1) collected with the BESIII detector at root s = 3.773 GeV. No significant signals are observed, and the corresponding upper limits on the branching fractions at the 90% confidence level are determined. The sensitivities of the results are at the level of 10(-5)-10(-6), providing a large improvement over previous searches.
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6.
  • Chong, Hui, et al. (author)
  • Organo-ptii complexes for potent photodynamic inactivation of multi-drug resistant bacteria and the influence of configuration
  • 2024
  • In: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 11:14
  • Journal article (peer-reviewed)abstract
    • PtII based organometallic photosensitizers (PSs) have emerged as novel potent photodynamic inactivation (PDI) reagents through their enhanced intersystem crossing (ISC) processes. Currently, few PtII PSs have been investigated as antibacterial materials, with relatively poor performances reported and with structure-activity relationships not well described. Herein, a pair of configurational isomers are reported of Bis-BODIPY (4,4-difluoro-boradizaindacene) embedded PtII PSs. The cis-isomer (cis-BBP) displayed enhanced 1O2 generation and better bacterial membrane anchoring capability as compared to the trans-isomer (trans-BBP). The effective PDI concentrations (efficiency > 99.9%) for cis-BBP in Acinetobacter baumannii (multi-drug resistant (MDR)) and Staphylococcus aureus are 400 nM (12 J cm−2) and 100 nM (18 J cm−2), respectively; corresponding concentrations and light doses for trans-BBP in the two bacteria are 2.50 µM (30 J cm−2) and 1.50 µM (18 J cm−2), respectively. The 50% and 90% minimum inhibitory concentration (MIC50 and MIC90) ratio of trans-BBP to cis-BBP is 22.22 and 24.02 in A. baumannii (MDR); 21.29 and 22.36 in methicillin resistant S. aureus (MRSA), respectively. Furthermore, cis-BBP displays superior in vivo antibacterial performance, with acceptable dark and photoinduced cytotoxicity. These results demonstrate cis-BBP is a robust light-assisted antibacterial reagent at sub-micromolecular concentrations. More importantly, configuration of PtII PSs should be an important issue to be considered in further PDI reagents design.
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7.
  • Wang, Longwei, et al. (author)
  • A Molybdenum Disulfide Nanozyme with Charge-Enhanced Activity for Ultrasound-Mediated Cascade-Catalytic Tumor Ferroptosis
  • 2023
  • In: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 62:11
  • Journal article (peer-reviewed)abstract
    • The deficient catalytic activity of nanozymes and insufficient endogenous H2O2 in the tumor microenvironment (TME) are major obstacles for nanozyme-mediated catalytic tumor therapy. Since electron transfer is the basic essence of catalysis-mediated redox reactions, we explored the contributing factors of enzymatic activity based on positive and negative charges, which are experimentally and theoretically demonstrated to enhance the peroxidase (POD)-like activity of a MoS2 nanozyme. Hence, an acidic tumor microenvironment-responsive and ultrasound-mediated cascade nanocatalyst (BTO/MoS2@CA) is presented that is made from few-layer MoS2 nanosheets grown on the surface of piezoelectric tetragonal barium titanate (T-BTO) and modified with pH-responsive cinnamaldehyde (CA). The integration of pH-responsive CA-mediated H2O2 self-supply, ultrasound-mediated charge-enhanced enzymatic activity, and glutathione (GSH) depletion enables out-of-balance redox homeostasis, leading to effective tumor ferroptosis with minimal side effects.
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8.
  • Wang, Xiaoyu, et al. (author)
  • Guest Editorial: Modeling and Simulation Methods for Analysis and Design of Advanced Energy Conversion Systems
  • 2020
  • In: IEEE Transactions on Energy Conversion. - 1558-0059 .- 0885-8969. ; 35:1, s. 309-311
  • Journal article (other academic/artistic)abstract
    • The papers in this special section examine modeling and simulation methods for the analysis and design of advanced energy conversion systems. Energy conversion lies aEnergyveral fronts including materials, conversion methods, power electronics, and controls have created new opportunities for efficient energy conversion from both the conventional and new sources of energy. Our urgent need to solve many critical problems with regards to the sustainability and security of our energy system as well as the ever-increasing environmental challenges facing humanity have further spurred unprecedented opportunities for creation of innovative solutions to address these challenges.
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9.
  • Wang, Yuying, et al. (author)
  • The prevalence of adverse reactions among individuals with three-dose COVID-19 vaccination
  • 2023
  • In: Journal of Infection and Public Health. - : Elsevier BV. - 1876-0341. ; 16:1, s. 125-132
  • Journal article (peer-reviewed)abstract
    • Background: Considering the adverse reactions to vaccination against coronavirus disease 2019 (COVID-19), some people, particularly the elderly and those with underlying medical conditions, are hesitant to be vaccinated. This study aimed to explore the prevalence of adverse reactions and provide direct evidence of vaccine safety, mainly for the elderly and people with underlying medical conditions, to receive COVID-19 vaccination. Methods: From 1st March to 30th April 2022, we conducted an online survey of people who had completed three doses of COVID-19 vaccination by convenience sampling. Adverse reaction rates and 95% confidence intervals were calculated. In addition, conditional logistic regression was used to compare the differences in adverse reactions among the elderly and those with underlying medical conditions with the general population. Results: A total of 3339 individuals were included in this study, of which 2335 (69.9%) were female, with an average age of 32.1 ± 11.4 years. The prevalence of adverse reactions after the first dose of inactivated vaccine was 24.6% (23.1–26.2%), 19.2% (17.8–20.7%) for the second dose, and 19.1% (17.7–20.6%) for the booster dose; among individuals using messenger RNA vaccines, the prevalence was 42.7% (32.3–53.6%) for the first dose, 47.2% (36.5–58.1%) for the second dose, and 46.1% (35.4–57.0%) for the booster dose. Compared with the general population, the prevalence of adverse events did not differ in individuals with underlying medical conditions and those aged 60 and above. Conclusions: For individuals with underlying medical conditions and those aged 60 and above, the prevalence of adverse reactions is similar to that of the general population, which provides a scientific basis regarding vaccination safety for these populations.
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10.
  • GUAN, WEN, et al. (author)
  • Frequency tuning behaviour of terahertz quantum cascade lasers revealed by a laser beating scheme
  • 2021
  • In: Optics Express. - 1094-4087 .- 1094-4087. ; 29:14, s. 21269-21279
  • Journal article (peer-reviewed)abstract
    • In the terahertz frequency range, the commercialized spectrometers, such as the Fourier transform infrared and time domain spectroscopies, show spectral resolutions between a hundred megahertz and a few gigahertz. Therefore, the high precision frequency tuning ability of terahertz lasers cannot be revealed by these traditional spectroscopic techniques. In this work, we demonstrate a laser beating experiment to investigate the frequency tuning characteristics of terahertz quantum cascade lasers (QCLs) induced by temperature or drive current. Two terahertz QCLs emitting around 4.2 THz with identical active regions and laser dimensions (150 μm wide and 6 mm long) are employed in the beating experiment. One laser is operated as a frequency comb and the other one is driven at a lower current to emit a single frequency. To measure the beating signal, the single mode laser is used as a fast detector (laser self-detection). The laser beating scheme allows the high precision measurement of the frequency tuning of the single mode terahertz QCL. The experimental results show that in the investigated temperature and current ranges, the frequency tuning coefficients of the terahertz QCL are 6.1 MHz/0.1 K (temperature tuning) and 2.7 MHz/mA (current tuning) that cannot be revealed by a traditional terahertz spectrometer. The laser beating technique shows potential abilities in high precision linewidth measurements of narrow absorption lines and multi-channel terahertz communications.
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11.
  • Wang, Huan, et al. (author)
  • Boosting the Electrochemical Performance of PI-5-CA/C-SWCNT Nanohybrid for Sensitive Detection of E. coli O157:H7 From the Real Sample
  • 2022
  • In: Frontiers in Chemistry. - : Frontiers Media SA. - 2296-2646. ; 10
  • Journal article (peer-reviewed)abstract
    • Redox activity is an important indicator for evaluating electrochemical biosensors. In this work, we have successfully polymerized indole-5-carboxylic acid into poly-5-carboxyindole nanomaterials (PI-5-CA), using its superior redox activity, and introduced carboxylated single-walled carbon nanotubes (C-SWCNTs) to synthesize a composite material. Finally, a synthesized composite material was used for the modification of the glass carbon electrode to fabricate the PI-5-CA/C-SWCNTs/GCE-based immunosensor and was successfully applied for the sensitive detection of E. coli O157:H7. The fabricated immunosensor exhibited an outstanding electrocatalytic activity toward the detection of E. coli O157:H7 with a remarkably lowest limit of detection (2.5 CFU/ml, LOD = 3 SD/k, n = 3) and has a wide linear range from 2.98x10(1) to 2.98x10(7) CFU/ml. Inspired from the excellent results, the fabricated electrode was applied for the detection of bacteria from real samples (water samples) with a good recovery rate (98.13-107.69%) as well as an excellent stability and specificity. Owing to its simple preparation, excellent performance, and detection time within 30 min, our proposed immunosensor will open a new horizon in different fields for the sensitive detection of bacteria from real samples.
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12.
  • Wang, Longwei, et al. (author)
  • Construction of S-N-C bond for boosting bacteria-killing by synergistic effect of photocatalysis and nanozyme
  • 2023
  • In: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 325
  • Journal article (peer-reviewed)abstract
    • Bacterial infection-related diseases are major public safety issues leads to millions of deaths annually. Herein, a porous sulfur doped graphitic carbon nitride (g-SCN) for ecofriendly, metal-free and low systemic toxicity were synthesized. Sulfur doping enables to broaden the absorption spectrum and promote the photocarriers separation for photocatalysis enhancement. Moreover, sulfur element will coordinate with nitrogen, changing the electronic state and endowing g-SCN with the property of nanozyme. More importantly, we established different models and confirmed that S-N-C coordination is the source of peroxidase (POD)-like activity through theory and experiment. The increased specific surface area of g-SCN, ascribing to the porous structure, makes it easier to trap bacteria. With the synergistic effect of photocatalysis and nanozyme, the prepared g-SCN has the ability to kill both gram-negative and gram-positive bacterium, with an antibacterial efficiency up to 100%. This work provides innovative synergistic strategy for constructing nanomaterials for highly efficient antibacterial therapy.
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13.
  • Wang, Lei, et al. (author)
  • Coumarin derivative trigger controlled photo-healing of ion gels and photo-controlled reversible adhesiveness
  • 2021
  • In: European Polymer Journal. - : Elsevier. - 0014-3057 .- 1873-1945. ; 144
  • Journal article (peer-reviewed)abstract
    • Fabrication strategies for photo-responsive ion gels have attracted attention owing to their precise spatial and temporal control with predetermined responses to light stimuli. In this work, a reversible light-driven method was introduced to devise photo-responsive ion gels by harnessing coumarin-based building blocks under 365 nm irradiation. A series of random copolymers composed of N, N-dimethylacrylamide (DMA) and 7-(2′-methacryloyloxyethoxy)–4-methylcoumarin (MAOEMC), namely P(DMA-r-MAOEMC), were synthesized through reversible addition-fragmentation chain transfer (RAFT) polymerization with sufficient molecular weight (≈100 kDa). The coumarin moieties in those polymers exhibited a reversible photo-induced dimerization and photocleavage behavior in 1-ethyl-3-methylimidazolium bis (trifluoromethylsufonyl) imide ([C2mim][NTf2]). Those polymers - ionic liquid system at high polymer concentration (20 wt%) under suitable wavelength UV light irradiation led to sol–gel transition, which could be functionalized as photo-healable material and photo-controlled adhesion agents. Notably, the photo-controlled adhesiveness was reversible and can be mediated from 1.2 MPa to 0.2 MPa. This work opens new avenues to develop multifunctional ion gels using dynamic covalent bonds.
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14.
  • Wang, Longwei, et al. (author)
  • Regulation of functional groups enable the metal-free PDINH/GO advisable antibacterial photocatalytic therapy
  • 2023
  • In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 451
  • Journal article (peer-reviewed)abstract
    • N-type organic semiconductor perylene-3,4,9,10-tetracarboxylic acid diimide (PDINH) are well-investigated photocatalyst. However, the photocatalytic potential for antibacterial therapy has been underexplored owing to the insufficient light absorption and rapid recombination of light-induced carriers. Herein, functional group-regulated is introduced by recrystallizing PDINH on the surface of GO in situ, endowing the PDINH/GO with enhanced photocatalytic properties, which harvest light energy across the full spectrum form ultraviolet to near-infrared. Simultaneously, the enhanced photogenerated carriers can activate Lewis base of GO to form an amide bond on the interface between bacteria and material, exhibiting high-efficient and steady bacteria trap. Compared with PDINH, both in vitro and in vivo all demonstrated PDINH/GO possess excellent antibacterial effect. In addition, as a non-metallic semiconductor, PDINH/GO shows capacity of enhancing epidermal cells proliferation and migration, resulting in successful infectious wound regeneration in mice and the side effects in vivo are negligible. Such the integration of wide-spectrum response, high efficiency of carrier separation, intentional bacterial capture and accelerated would healing of PDINH/GO not only enables an effective antibacterial therapy but also contributes to a successful example to activate nanomaterials by regulation of functional groups.
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15.
  • Xie, Haibing, et al. (author)
  • Decoupling the effects of defects on efficiency and stability through phosphonates in stable halide perovskite solar cells
  • 2021
  • In: Joule. - : CELL PRESS. - 2542-4351. ; 5:5, s. 1246-1266
  • Journal article (peer-reviewed)abstract
    • Understanding defects is of paramount importance for the development of stable halide perovskite solar cells (PSCs). However, isolating their distinctive effects on device efficiency and stability is currently a challenge. We report that adding the organic molecule 3-phosphonopropionic acid (H3pp) to the halide perovskite results in unchanged overall optoelectronic performance while having a tremendous effect on device stability. We obtained PSCs with similar to 21% efficiency that retain similar to 100% of the initial efficiency after 1,000 h at the maximum power point under simulated AM1.5G illumination. The strong interaction between the perovskite and the H3pp molecule through two types of hydrogen bonds (H center dot center dot center dot I and O center dot center dot center dot H) leads to shallow point defect passivation that has a significant effect on device stability but not on the non-radiative recombination and device efficiency. We expect that our work will have important implications for the current understanding and advancement of operational PSCs.
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16.
  • Zhang, Shuai, et al. (author)
  • High sensitive assay of formaldehyde using resonance light scattering technique based on carbon dots aggregation
  • 2023
  • In: Arabian Journal of Chemistry. - : Elsevier. - 1878-5352 .- 1878-5379. ; 16:6
  • Journal article (peer-reviewed)abstract
    • Formaldehyde (FA) is widely used in industry and also common in daily life. Finding an efficient method to determine FA is quite an industrial challenge. Herein, a novel method based on a resonance light scattering (RLS) technique was developed for the detection of FA with high sensitivity. Carbon dots (CDs) were used as RLS probes. CDs were obtained via one-pot solvothermal treatment from o-phenylenediamine. CDs showed yellow fluorescence with a quantum yield of 0.41. Due to the multiple amino groups on the surface of CDs, FA can be captured easily by formation of a covalent C = N bond based on the Schiff-base reaction. Owing to the covalent crosslinking, CD nanoparticles aggregated, and even formed precipitate. The aggregation of CDs induced RLS enhancement, where the RLS increment was linearly related to the concentration of FA ranging from 4 nM to 1.6 mM, with a limit of detection (LOD) of 1.6 nM. In comparison with many previous reports, the present RLS method showed a wider linear range and lower LOD. Furthermore, the RLS system was successfully used to detect FA in real food samples. The proposed system has prospective applicability in the detection of FA in food fields.
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17.
  • Zhang, Xiaoyu, et al. (author)
  • Causality assessment of circulating Vitamin D level on venous thromboembolism : A Mendelian randomization study
  • 2023
  • In: Nutrition, Metabolism and Cardiovascular Diseases. - 0939-4753. ; 33:9, s. 1800-1807
  • Journal article (peer-reviewed)abstract
    • Background and aims: The associations of vitamin D level with venous thromboembolism (VTE) reported in observational studies, whereas these causal associations were uncertain in European population. Therefore, we used Mendelian randomization (MR) method to explore the causal associations between 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of VTE and its subtypes [including deep vein thrombosis (DVT) and pulmonary embolism (PE)]. Methods and results: We used three kinds of genetic instruments to proxy the exposure of 25(OH)D, including genetic variants significantly associated with 25(OH)D, expression quantitative trait loci of 25(OH)D target genes, and genetic variants within or nearby 25(OH)D target genes. MR analyses did not provide any evidence for the associations of 25(OH)D levels with VTE and its subtypes (p > 0.05). The summary-data-based MR (SMR) analyses indicated that elevated expression of VDR was associated with decreased risk of VTE (OR = 0.81; 95% CI, 0.65–0.998; p = 0.047) and PE (OR = 0.67; 95% CI, 0.50–0.91; p = 0.011), and expression of AMDHD1 was associated with PE (OR = 0.93; 95% CI, 0.88–0.99; p = 0.027). MR analysis provided a significant causal effect of 25(OH)D level mediated by gene AMDHD1 on PE risk (OR = 0.09; 95% CI, 0.01–0.60; p = 0.012). Conclusion: Our MR analysis did not support causal association of 25(OH)D level with the risk of VTE and its subtypes. In addition, the expression of VDR and AMDHD1 involved in vitamin D metabolism showed a strong association with VTE or PE and might represent targets for these conditions.
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18.
  • Zhao, Xiaoyu, et al. (author)
  • Identification of genetically predicted DNA methylation markers associated with non–small cell lung cancer risk among 34,964 cases and 448,579 controls
  • 2024
  • In: Cancer. - : John Wiley & Sons. - 0008-543X .- 1097-0142. ; 130:6, s. 913-926
  • Journal article (peer-reviewed)abstract
    • Background: Although the associations between genetic variations and lung cancer risk have been explored, the epigenetic consequences of DNA methylation in lung cancer development are largely unknown. Here, the genetically predicted DNA methylation markers associated with non–small cell lung cancer (NSCLC) risk by a two-stage case-control design were investigated.Methods: The genetic prediction models for methylation levels based on genetic and methylation data of 1595 subjects from the Framingham Heart Study were established. The prediction models were applied to a fixed-effect meta-analysis of screening data sets with 27,120 NSCLC cases and 27,355 controls to identify the methylation markers, which were then replicated in independent data sets with 7844 lung cancer cases and 421,224 controls. Also performed was a multi-omics functional annotation for the identified CpGs by integrating genomics, epigenomics, and transcriptomics and investigation of the potential regulation pathways.Results: Of the 29,894 CpG sites passing the quality control, 39 CpGs associated with NSCLC risk (Bonferroni-corrected p ≤ 1.67 × 10−6) were originally identified. Of these, 16 CpGs remained significant in the validation stage (Bonferroni-corrected p ≤ 1.28 × 10−3), including four novel CpGs. Multi-omics functional annotation showed nine of 16 CpGs were potentially functional biomarkers for NSCLC risk. Thirty-five genes within a 1-Mb window of 12 CpGs that might be involved in regulatory pathways of NSCLC risk were identified.Conclusions: Sixteen promising DNA methylation markers associated with NSCLC were identified. Changes of the methylation level at these CpGs might influence the development of NSCLC by regulating the expression of genes nearby.Plain Language Summary: The epigenetic consequences of DNA methylation in lung cancer development are still largely unknown. This study used summary data of large-scale genome-wide association studies to investigate the associations between genetically predicted levels of methylation biomarkers and non–small cell lung cancer risk at the first time. This study looked at how well larotrectinib worked in adult patients with sarcomas caused by TRK fusion proteins. These findings will provide a unique insight into the epigenetic susceptibility mechanisms of lung cancer.
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19.
  • Aquila, Andrew, et al. (author)
  • Time-resolved protein nanocrystallography using an X-ray free-electron laser
  • 2012
  • In: Optics Express. - 1094-4087. ; 20:3, s. 2706-2716
  • Journal article (peer-reviewed)abstract
    • We demonstrate the use of an X-ray free electron laser synchronized with an optical pump laser to obtain X-ray diffraction snapshots from the photoactivated states of large membrane protein complexes in the form of nanocrystals flowing in a liquid jet. Light-induced changes of Photosystem I-Ferredoxin co-crystals were observed at time delays of 5 to 10 µs after excitation. The result correlates with the microsecond kinetics of electron transfer from Photosystem I to ferredoxin. The undocking process that follows the electron transfer leads to large rearrangements in the crystals that will terminally lead to the disintegration of the crystals. We describe the experimental setup and obtain the first time-resolved femtosecond serial X-ray crystallography results from an irreversible photo-chemical reaction at the Linac Coherent Light Source. This technique opens the door to time-resolved structural studies of reaction dynamics in biological systems.
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20.
  • Berglund, Erik, et al. (author)
  • Zeroth-order randomized subspace newton methods
  • 2022
  • In: 2022 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 6002-6006
  • Conference paper (peer-reviewed)abstract
    • Zeroth-order methods have become important tools for solving problems where we have access only to function evaluations. However, the zeroth-order methods only using gradient approximations are n times slower than classical first-order methods for solving n-dimensional problems. To accelerate the convergence rate, this paper proposes the zeroth order randomized subspace Newton (ZO-RSN) method, which estimates projections of the gradient and Hessian by random sketching and finite differences. This allows us to compute the Newton step in a lower dimensional subspace, with small computational costs. We prove that ZO-RSN can attain lower iteration complexity than existing zeroth order methods for strongly convex problems. Our numerical experiments show that ZO-RSN can perform black-box attacks under a more restrictive limit on the number of function queries than the state-of-the-art Hessian-aware zeroth-order method.
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21.
  • Chapman, Henry N, et al. (author)
  • Femtosecond X-ray protein nanocrystallography.
  • 2011
  • In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 470:7332, s. 73-7
  • Journal article (peer-reviewed)abstract
    • X-ray crystallography provides the vast majority of macromolecular structures, but the success of the method relies on growing crystals of sufficient size. In conventional measurements, the necessary increase in X-ray dose to record data from crystals that are too small leads to extensive damage before a diffraction signal can be recorded. It is particularly challenging to obtain large, well-diffracting crystals of membrane proteins, for which fewer than 300 unique structures have been determined despite their importance in all living cells. Here we present a method for structure determination where single-crystal X-ray diffraction 'snapshots' are collected from a fully hydrated stream of nanocrystals using femtosecond pulses from a hard-X-ray free-electron laser, the Linac Coherent Light Source. We prove this concept with nanocrystals of photosystem I, one of the largest membrane protein complexes. More than 3,000,000 diffraction patterns were collected in this study, and a three-dimensional data set was assembled from individual photosystem I nanocrystals (∼200nm to 2μm in size). We mitigate the problem of radiation damage in crystallography by using pulses briefer than the timescale of most damage processes. This offers a new approach to structure determination of macromolecules that do not yield crystals of sufficient size for studies using conventional radiation sources or are particularly sensitive to radiation damage.
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22.
  • D'Humières, Benoit, et al. (author)
  • The C3PO project : A laser communication system concept for small satellites
  • 2017
  • In: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 9781510606333
  • Conference paper (peer-reviewed)abstract
    • The satellite market is shifting towards smaller (micro and nanosatellites), lowered mass and increased performance platforms. Nanosatellites and picosatellites have been used for a number of new, innovative and unique payloads and missions. This trend requires new concepts for a reduced size, a better performance/weight ratio and a reduction of onboard power consumption. In this context, disruptive technologies, such as laser-optical communication systems, are opening new possibilities. This paper presents the C3PO1 system, "advanced Concept for laser uplink/ downlink CommuniCation with sPace Objects", and the first results of the development of its key technologies. This project targets the design of a communications system that uses a ground-based laser to illuminate a satellite, and a Modulating Retro-Reflector (MRR) to return a beam of light modulated by data to the ground. This enables a downlink, without a laser source on the satellite. This architecture suits well to small satellite applications so as high data rates are potentially provided with very low board mass. C3PO project aims to achieve data rates of 1Gbit/s between LEO satellites and Earth with a communication payload mass of less than 1kilogram. In this paper, results of the initial experiments and demonstration of the key technologies will be shown.
  •  
23.
  • Fan, Xiaoyu, et al. (author)
  • Paper test strip for silver ions detection in drinking water samples based on combined fluorometric and colorimetric methods
  • 2023
  • In: Arabian Journal of Chemistry. - : Elsevier. - 1878-5352 .- 1878-5379. ; 16:2
  • Journal article (peer-reviewed)abstract
    • In this study, a portable silver ion (Ag+) sensor was fabricated based on a dual signal output system using black phosphorus quantum dots (BPQDs) as probes. It is the first work for Ag+ detection using paper test strip based on BPQDs. The color change of BPQDs paper sensor for the determination of Ag+ was easily identified by naked eye. BPQDs were synthesized from bulk black phosphorus (BP) by mechanical exfoliation combined with a solvothermal method. BPQDs exhibited blue fluorescence with a quantum yield of 8.82 %. The fluorescence of BPQDs can be quenched by Ag+, and the absorbance of BPQDs is increased with increasing Ag+ concentration. The mechanism of the interaction between BPQDs and Ag+ involving fluorescence quenching and bonding was investigated by experimental and computational methods. The detection limit of Ag+ was 1.56 μg/mL and 0.19 μg/mL using fluorometry and colorimetry methods, respectively. A portable visual sensor based on paper test strip was constructed for Ag+ detection using the colorimetric approach. The strategy was employed to determine Ag+ successfully in drinking water samples. Therefore, the proposed portable Ag+ sensor can be potentially utilized for the lab-free analysis of drinking water and even dietary samples.
  •  
24.
  • Jia, Xiaoyu, et al. (author)
  • Chemical and Structural Engineering of Gelatin-Based Delivery Systems for Therapeutic Applications : A Review
  • 2024
  • In: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 25:2, s. 564-589
  • Research review (peer-reviewed)abstract
    • As a biodegradable and biocompatible protein derived from collagen, gelatin has been extensively exploited as a fundamental component of biological scaffolds and drug delivery systems for precise medicine. The easily engineered gelatin holds great promise in formulating various delivery systems to protect and enhance the efficacy of drugs for improving the safety and effectiveness of numerous pharmaceuticals. The remarkable biocompatibility and adjustable mechanical properties of gelatin permit the construction of active 3D scaffolds to accelerate the regeneration of injured tissues and organs. In this Review, we delve into diverse strategies for fabricating and functionalizing gelatin-based structures, which are applicable to gene and drug delivery as well as tissue engineering. We emphasized the advantages of various gelatin derivatives, including methacryloyl gelatin, polyethylene glycol-modified gelatin, thiolated gelatin, and alendronate-modified gelatin. These derivatives exhibit excellent physicochemical and biological properties, allowing the fabrication of tailor-made structures for biomedical applications. Additionally, we explored the latest developments in the modulation of their physicochemical properties by combining additive materials and manufacturing platforms, outlining the design of multifunctional gelatin-based micro-, nano-, and macrostructures. While discussing the current limitations, we also addressed the challenges that need to be overcome for clinical translation, including high manufacturing costs, limited application scenarios, and potential immunogenicity. This Review provides insight into how the structural and chemical engineering of gelatin can be leveraged to pave the way for significant advancements in biomedical applications and the improvement of patient outcomes.
  •  
25.
  • Johansson, Linda C, 1983, et al. (author)
  • Lipidic phase membrane protein serial femtosecond crystallography.
  • 2012
  • In: Nature methods. - : Springer Science and Business Media LLC. - 1548-7105 .- 1548-7091. ; 9:3, s. 263-265
  • Journal article (peer-reviewed)abstract
    • X-ray free electron laser (X-FEL)-based serial femtosecond crystallography is an emerging method with potential to rapidly advance the challenging field of membrane protein structural biology. Here we recorded interpretable diffraction data from micrometer-sized lipidic sponge phase crystals of the Blastochloris viridis photosynthetic reaction center delivered into an X-FEL beam using a sponge phase micro-jet.
  •  
26.
  • Khirirat, Sarit, et al. (author)
  • Improved Step-Size Schedules for Noisy Gradient Methods
  • 2021
  • In: ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). - Toronto, ON, Canada : IEEE. - 9781728176055 ; , s. 3655-3659
  • Conference paper (peer-reviewed)abstract
    • Noise is inherited in many optimization methods such as stochastic gradient methods, zeroth-order methods and compressed gradient methods. For such methods to converge toward a global optimum, it is intuitive to use large step-sizes in the initial iterations when the noise is typically small compared to the algorithm-steps, and reduce the step-sizes as the algorithm progresses. This intuition has been con- firmed in theory and practice for stochastic gradient methods,but similar results are lacking for other methods using approximate gradients. This paper shows that the diminishing step-size strategies can indeed be applied for a broad class of noisy gradient methods. Unlike previous works, our analysis framework shows that such step-size schedules enable these methods to enjoy an optimal O(1/k) rate. We exemplify our results on zeroth-order methods and stochastic compression methods. Our experiments validate fast convergence of these methods with the step decay schedules.
  •  
27.
  • Khirirat, Sarit, et al. (author)
  • Improved Step-Size Schedules for Proximal Noisy Gradient Methods
  • 2023
  • In: IEEE Transactions on Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-587X .- 1941-0476. ; 71, s. 189-201
  • Journal article (peer-reviewed)abstract
    • Noisy gradient algorithms have emerged as one of the most popular algorithms for distributed optimization with massive data. Choosing proper step-size schedules is an important task to tune in the algorithms for good performance. For the algorithms to attain fast convergence and high accuracy, it is intuitive to use large step-sizes in the initial iterations when the gradient noise is typically small compared to the algorithm-steps, and reduce the step-sizes as the algorithm progresses. This intuition has been confirmed in theory and practice for stochastic gradient descent. However, similar results are lacking for other methods using approximate gradients. This paper shows that the diminishing step-size strategies can indeed be applied for a broad class of noisy gradient algorithms. Our analysis framework is based on two classes of systems that characterize the impact of the step-sizes on the convergence performance of many algorithms. Our results show that such step-size schedules enable these algorithms to enjoy the optimal rate. We exemplify our results on stochastic compression algorithms. Our experiments validate fast convergence of these algorithms with the step decay schedules.
  •  
28.
  • Kirian, Richard A., et al. (author)
  • Structure-factor analysis of femtosecond micro-diffraction patterns from protein nanocrystals
  • 2011
  • In: Acta Crystallographica Section A. - 0108-7673 .- 1600-5724. ; 67:2, s. 131-140
  • Journal article (peer-reviewed)abstract
    • A complete set of structure factors has been extracted from hundreds of thousands of femtosecond single-shot X-ray microdiffraction patterns taken from randomly oriented nanocrystals. The method of Monte Carlo integration over crystallite size and orientation was applied to experimental data from Photosystem I nanocrystals. This arrives at structure factors from many partial reflections without prior knowledge of the particle-size distribution. The data were collected at the Linac Coherent Light Source (the first hard-X-ray laser user facility), to which was fitted a hydrated protein nanocrystal injector jet, according to the method of serial crystallography. The data are single 'still' diffraction snapshots, each from a different nanocrystal with sizes ranging between 100 nm and 2 mu m, so the angular width of Bragg peaks was dominated by crystal-size effects. These results were compared with single-crystal data recorded from large crystals of Photosystem I at the Advanced Light Source and the quality of the data was found to be similar. The implications for improving the efficiency of data collection by allowing the use of very small crystals, for radiation-damage reduction and for time-resolved diffraction studies at room temperature are discussed.
  •  
29.
  • Koopmann, Rudolf, et al. (author)
  • In vivo protein crystallization opens new routes in structural biology
  • 2012
  • In: Nature Methods. - : Springer Science and Business Media LLC. - 1548-7091 .- 1548-7105. ; 9:3, s. 259-262
  • Journal article (peer-reviewed)abstract
    • Protein crystallization in cells has been observed several times in nature. However, owing to their small size these crystals have not yet been used for X-ray crystallographic analysis. We prepared nano-sized in vivo–grown crystals of Trypanosoma brucei enzymes and applied the emerging method of free-electron laser-based serial femtosecond crystallography to record interpretable diffraction data. This combined approach will open new opportunities in structural systems biology.
  •  
30.
  • Lan, Xiaoyu, et al. (author)
  • Self-Assembly of Diblock Copolymers Containing Thermo- and Photoresponsive Lower Critical Solution Temperature Phase Behavior Polymer with Tunable Assembly Temperature in an Ionic Liquid Mixture
  • 2019
  • In: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 4:6, s. 11229-11236
  • Journal article (peer-reviewed)abstract
    • This work prepared a type of diblock copolymer with thermo- and photosensitivity in ionic liquids (ILs). P(N,N-dimethylacrylamide) (compatible with ILs) was prepared as one segment, while butyl acrylate (BA) and 4-phenylazophenylmethacrylate (AzoMA) were copolymerized as another segment P(AzoMA-r-BA) with stimuli responsiveness. The diblock copolymer showed tunable lower critical micellization temperature (LCMT) in two mixed imidazole ionic liquids. The value of LCMT depends on not only the conformation status of the azo group in copolymers but also the azo group content in copolymers and mixed ratio of ionic liquids. Based on this tunable LCMT, photoinduced micellization/demicellization can be achieved near room temperature by alternate irradiation with visible and ultraviolet light, and it is totally reversible.
  •  
31.
  • Li, Han, et al. (author)
  • Advancements of nature nanocage protein : preparation, identification and multiple applications of ferritins
  • 2022
  • In: Critical reviews in food science and nutrition. - : Informa UK Limited. - 1040-8398 .- 1549-7852. ; 62:25, s. 7117-7128
  • Research review (peer-reviewed)abstract
    • Ferritin is an important iron storage protein, which is widely existed in all forms of life. Ferritin can regulate iron homeostasis when iron ions are lacking or enriched in the body, so as to avoid iron deficiency diseases and iron poisoning. Ferritin presents a hollow nanocage, which can store ions or other small molecular substances in the cavity. Therefore, ferritin shows its potential as a functional nanomaterial that can deliver nutrients or drugs in a targeted manner to improve bioavailability. Due to the special structure, the research on ferritin has attracted more and more attention in recent years. In this paper, the structural characteristics of ferritin were introduced, and the natural purification and prokaryotic expression methods of ferritin from different sources were described. At the same time, ferritin can bind to small molecules, so that it has the activity of small molecules, to construct a new type of ferritin. As a result, ferritin plays an important role as a nutrient substance, in targeted transport, and disease monitoring, etc. In conclusion, the yield of ferritin can be improved by means of molecular biology. Meanwhile, molecular modification can be used to make ferritin have unique activity and function, which lays a foundation for subsequent research.
  •  
32.
  • Li, Han, et al. (author)
  • Improvement of thermal stability of oyster (Crassostrea gigas) ferritin by point mutation
  • 2021
  • In: Food Chemistry. - : Elsevier. - 0308-8146 .- 1873-7072. ; 346
  • Journal article (peer-reviewed)abstract
    • Ferritin can be widely used as functional nanomaterial. But the physiological activity of ferritin can be damaged under excessive temperatures, which affect the self-assembly property. In this study, point mutation was produced in Asp120 to Gly120 of ferritin amino acid sequence and the heat resistance was improved significantly. The thermal denaturation temperature of mutated ferritin is 89.17 degrees C and has increased by 13 degrees C more than the wildtype oyster ferritin. The effect of thermal treatment on the denaturation, aggregation state, particle size and the structure of ferritin was not changed before 90 degrees C. The computational modeling and analysis indicated that mutated ferritin promotes the overall structural stability assembly via decreasing the interaction energies of 62 percent energies in 3-fold interface. Improving the thermal stability of oyster ferritin by point mutation enhances its applications as a food ingredient.
  •  
33.
  • Li, Ning, et al. (author)
  • Associations of genetically determined lipid traits and lipid-modifying agents with the risk of diabetic retinopathy : A Mendelian randomization study
  • 2023
  • In: Atherosclerosis. - : Elsevier BV. - 1879-1484 .- 0021-9150. ; 369, s. 9-16
  • Journal article (peer-reviewed)abstract
    • BACKGROUND AND AIMS: The evidence that dyslipidemia is associated with hyperglycemia calls for an investigation of whether dyslipidemia, as well as lipid-modifying agents, could affect the subsequent development of diabetic retinopathy (DR). Therefore, we aimed to address these unanswered questions by utilizing Mendelian randomization (MR) analysis.METHODS: Genetic variants were selected from the UK Biobank as instruments to serve as proxies for lipid traits [high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG), apolipoprotein A-I (APOA-I) and apolipoprotein B (APOB)]. Univariable and multivariable MR analyses were performed to examine the associations of these lipid traits with DR and different levels of severity of DR. Based on the evidence for the effects of lipids on outcomes, we estimated the causal relevance of cholesteryl ester transfer protein (CETP) inhibitors in severe nonproliferative and proliferative DR using protein quantitative trait loci (pQTLs) and expression quantitative trait loci (eQTLs) as instruments.RESULTS: Genetically determined HDL-C levels were inversely associated with the risk of severe nonproliferative DR (OR = 0.70, 95% CI = 0.52-0.94) and proliferative DR (OR = 0.90, 95% CI = 0.83-0.97) in the main analyses utilizing the inverse variance-weighted (IVW) MR method and a couple of sensitivity analyses. No association was noted between genetically proxied CETP inhibitors and DR.CONCLUSIONS: This MR study suggests the casual protective roles of HDL-C in severe nonproliferative DR and proliferative DR, which calls for further studies to confirm these findings. Current lipid-modifying agents acting on HDL-C may not reduce the risk of DR and new treatments are required in the future.
  •  
34.
  • Li, Xiaochun, et al. (author)
  • Bidirectional associations of intellectual and social activities with cognitive function among middle-aged and elderly adults in China
  • 2022
  • In: Journal of Affective Disorders. - : Elsevier BV. - 0165-0327. ; 319, s. 83-89
  • Journal article (peer-reviewed)abstract
    • Background: Previous studies evaluating the association between leisure activities and cognitive function produced conflicting results. Different types of leisure activities may have different effects on cognition, and very few studies have explored their bidirectional associations. Our study aimed to explore whether intellectual and social activities had bidirectional associations with cognitive function among the middle-aged and elderly adults in China. Methods: Data was derived from the China Health and Retirement Longitudinal Study. The data in this study were based on 11,549 participants aged 45 or older whose intellectual and social activities and cognitive function were assessed at baseline. Cross-lagged panel model was used to examine the temporal relationship of intellectual and social activities with cognitive function. Results: Totally, 5624 participants completed the third follow-up in 2018. The results showed that the better the cognitive function they had at baseline, the more intellectual activities they were engage in (β = 0.044, P < 0.001) and vice versa (β = 0.042, P = 0.001). Additionally, better cognitive function at baseline was significantly associated with more engagement in social activities (β = 0.028, P = 0.030); in contrast, higher engagement in social activities at baseline was not related to better cognitive function (β = −0.008, P = 0.523). Limitations: Engagement in social and intellectual activities was assessed via questionnaire. Conclusions: Our findings indicated that there was a bidirectional relationship between intellectual activities and cognitive function. However, participation in social activities did not slow down the decline in cognitive function. Participating in intellectual activities, compared to social activities, is especially beneficial for cognitive function.
  •  
35.
  • Li, Xiaoyu, et al. (author)
  • Lithium-ion batteries fault diagnostic for electric vehicles using sample entropy analysis method
  • 2020
  • In: Journal of Energy Storage. - : Elsevier BV. - 2352-152X. ; 27
  • Journal article (peer-reviewed)abstract
    • Fault detection plays a vital role in the operation of lithium-ion batteries in electric vehicles. Typically, during the operation of battery systems, voltage signals are susceptible to noise interference. In this paper, a novel fault detection method based on the Empirical Mode Decomposition and Sample Entropy is proposed to identify battery faults under various operating conditions. Firstly, effective fault features are extracted through the proposed Empirical Mode Decomposition method by decomposing battery voltage signals and removing the noise interference during the voltage sampling process. Experiments are conducted to quantitatively illustrate the fault features extracted by the Empirical Mode Decomposition. Then, based on these extracted fault features, the Sample Entropy values are calculated to help accurately detect and locate the battery faults. Moreover, an evaluation strategy of the detected faults is designed to indicate the battery fault level. Finally, the effectiveness of the proposed approach is verified against real-world data measured from electric vehicles in the presence of regular and sudden faults.
  •  
36.
  • Li, Xiaoyu, et al. (author)
  • State-of-health estimation for Li-ion batteries by combing the incremental capacity analysis method with grey relational analysis
  • 2019
  • In: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 410-411, s. 106-114
  • Journal article (peer-reviewed)abstract
    • An accurate battery state-of-health (SOH) monitoring is crucial to guarantee safe and reliable operation of electric vehicles (EVs). In this paper, an incremental capacity analysis (ICA) method for battery SOH estimation is proposed. This uses grey relational analysis in combination with the entropy weight method. First, an interpolation method is employed to obtain incremental capacity (IC) curves. The health indexes are then extracted from the partial IC curves for grey relational analysis, and the entropy weight method is used to evaluate the significance of each health index. The battery SOH is assessed by calculating the grey relational degree between the reference and comparative sequences. Experimental tests are conducted on two battery cells with the same specifications to verify the efficacy of the proposed method. The results show that the maximum estimation error is limited to within 4%, thus proving its effectiveness.
  •  
37.
  • Li, Zhixuan, et al. (author)
  • Revealing two radio-active galactic nuclei extremely near PSR J0437−4715
  • 2018
  • In: Monthly Notices of the Royal Astronomical Society. - : Oxford University Press (OUP). - 0035-8711 .- 1365-2966. ; 476:1, s. 399-406
  • Journal article (peer-reviewed)abstract
    • Newton's gravitational constant G may vary with time at an extremely low level. The time variability of G will affect the orbital motion of a millisecond pulsar in a binary system and cause a tiny difference between the orbital period-dependent measurement of the kinematic distance and the direct measurement of the annual parallax distance. PSR J0437-4715 is the nearest millisecond pulsar and the brightest at radio wavelengths. To explore the feasibility of achieving a parallax distance accuracy of one light-year, comparable to the recent timing result, with the technique of differential astrometry, we searched for compact radio sources quite close to PSR J0437-4715. Using existing data from the Very Large Array and the Australia Telescope Compact Array, we detected two sources with flat spectra, relatively stable flux densities of 0.9 and 1.0 mJy at 8.4 GHz and separations of 13 and 45 arcsec. With a network consisting of the Long Baseline Array and the Kunming 40-m radio telescope, we found that both sources have a point-like structure and a brightness temperature of >= 10(7) K. According to these radio inputs and the absence of counterparts in other bands, we argue that they are most likely the compact radio cores of extragalactic active galactic nuclei, rather than Galactic radio stars. The finding of these two radio active galactic nuclei will enable us to achieve a sub-pc distance accuracy with in-beam phase-referencing very-long-baseline interferometric observations and provide one of the most stringent constraints on the time variability of G in the near future.
  •  
38.
  • Lomb, Lukas, et al. (author)
  • Radiation damage in protein serial femtosecond crystallography using an x-ray free-electron laser
  • 2011
  • In: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 84:21, s. 214111-1-214111-6
  • Journal article (peer-reviewed)abstract
    • X-ray free-electron lasers deliver intense femtosecond pulses that promise to yield high resolution diffraction data of nanocrystals before the destruction of the sample by radiation damage. Diffraction intensities of lysozyme nanocrystals collected at the Linac Coherent Light Source using 2 keV photons were used for structure determination by molecular replacement and analyzed for radiation damage as a function of pulse length and fluence. Signatures of radiation damage are observed for pulses as short as 70 fs. Parametric scaling used in conventional crystallography does not account for the observed effects.
  •  
39.
  • Long, Junshui, et al. (author)
  • Hydrological Projections in the Third Pole Using Artificial Intelligence and an Observation-Constrained Cryosphere-Hydrology Model
  • 2024
  • In: EARTHS FUTURE. - 2328-4277. ; 12:4
  • Journal article (peer-reviewed)abstract
    • The water resources of the Third Pole (TP), highly sensitive to climate change and glacier melting, significantly impact the water and food security of millions in Asia. However, projecting future spatial-temporal runoff changes for TP's mountainous basins remains a formidable challenge. Here, we've leveraged the long short-term memory model (LSTM) to craft a grid-scale artificial intelligence (AI) model named LSTM-grid. This model has enabled the production of hydrological projections for the seven major river basins of TP. The LSTM-grid model integrates monthly precipitation, air temperature, and total glacier mass changes (total_GMC) data at a 0.25-degree model grid. Training the LSTM-grid model employed gridded historical monthly runoff and evapotranspiration data sets generated by an observation-constrained cryosphere-hydrology model at the headwaters of seven TP river basins during 2000-2017. Our results demonstrate the LSTM grid's effectiveness and usefulness, exhibiting a Nash-Sutcliffe Efficiency coefficient exceeding 0.92 during the verification periods (2013-2017). Moreover, river basins in the monsoon region exhibited a higher rate of runoff increase compared to those in the westerlies region. Intra-annual projections indicated notable increases in spring runoff, especially in basins where glacier meltwater significantly contributes to runoff. Additionally, the LSTM-grid model aptly captures the runoff changes before and after the turning points of glacier melting, highlighting the growing influence of precipitation on runoff after reaching the maximum total_GMC. Therefore, the LSTM-grid model offers a fresh perspective for understanding the spatiotemporal distribution of water resources in high-mountain glacial regions by tapping into AI's potential to drive scientific discovery and provide reliable data. Water resources of the Third Pole (TP) significantly impact the water and food security in Asia. However, projecting future spatial-temporal runoff changes for the TP's mountain basins remains a challenge. Here, we've leveraged the long short-term memory (LSTM) model to craft a gridded artificial intelligence model (named LSTM-grid). Trained by the outputs of an observation-constrained distributed cryosphere-hydrology model, the LSTM-grid has enabled reliable spatiotemporal runoff and evapotranspiration projections for the headwaters of seven TP rivers (Yellow, Yangtze, Mekong, Salween, Brahmaputra, Ganges, Indus) till 2100. Our projections show that the river basins in the monsoon region exhibit a higher rate of runoff increase compared to those in the westerlies region. In particular, the proposed approach in this study can reasonably capture the runoff changes before and after the turning points of glacier melting without prior knowledge, highlighting the growing influence of precipitation on runoff after reaching the maximum total glacier mass changes (of a river basin). Hence, the LSTM-grid model provides a fresh perspective for understanding the spatiotemporal distribution of water resources in high-mountain glacial regions. We use artificial intelligence and an observation-constrained cryosphere-hydrology model to project future runoff for seven high-mountain Third Pole basins Results show that river basins in the monsoon region exhibited a higher rate of runoff increase compared to those in the westerlies region The proposed approach can aptly simulate runoff changes before and after the turning points of glacier melting without prior knowledge
  •  
40.
  • Ma, Xiaofeng, et al. (author)
  • Photo-induced Actuator using Temperature and Light Dual Responsive Azobenzene Containing Ion Gel in Ionic Liquid
  • 2020
  • In: European Polymer Journal. - : Elsevier. - 0014-3057 .- 1873-1945. ; 123
  • Journal article (peer-reviewed)abstract
    • A series of well-defined random copolymers comprising butyl acrylate (BA) and 4-phenylazophenylmethacrylate (AzoMA) (P(AzoMA-r-BA)) are prepared successfully by reversible addition fragmentation chain transfer (RAFT) polymerization. P(AzoMA-r-BA)s show LCST-type phase transition in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfone)amide ([C4mim][NTf2]). LCST depends on the photoisomerization state of azobenzene, as well as on the AzoMA composition in the random copolymers. LCST of (P(cis-AzoMA-r-BA) is significantly higher than that of P(trans-AzoMA-r-BA), because cis-AzoMA and trans-AzoMA behave as solvato-philic and solvato-phobic comonomer, respectively. At a bistable temperature, photo-induced phase separation is completely reversible. Secondly, based on this phenomenon, a thermo- / photo- responsive ion gel (BA-AzoMA ion gel) can be prepared by free radical polymerization of BA and AzoMA using ethylene glycol dimethacrylate (EGDMA) as crosslinker in [C4mim][NTf2]. BA-AzoMA ion gel shows high temperature contraction and low temperature expansion behavior, due to LCST-type phase behavior of polymer system consisting of AzoMA and BA. Contraction temperature of BA-AzoMA ion gel depends on photoisomerization state of the azobenzene group in polymers. At a bistable temperature, photo-induced expansion-contraction is reversible. Finally, a Photo-induced actuator can be realized using BA-AzoMA ion gel at suitable temperatures, featuring reversible bending by alternate irradiating with visible and UV light. The bending behavior is also demonstrated.
  •  
41.
  • Mueller, Sven Christian, et al. (author)
  • Interfacing Power System and ICT Simulators : Challenges, State-of-the-Art, and Case Studies
  • 2018
  • In: IEEE Transactions on Smart Grid. - : Institute of Electrical and Electronics Engineers (IEEE). - 1949-3053 .- 1949-3061. ; 9:1, s. 14-24
  • Journal article (peer-reviewed)abstract
    • With the transition toward a smart grid, the power system has become strongly intertwined with the information and communication technology (ICT) infrastructure. The interdependency of both domains requires a combined analysis of physical and ICT processes, but simulating these together is a major challenge due to the fundamentally different modeling and simulation concepts. After outlining these challenges, such as time synchronization and event handling, this paper presents an overview of state-of-the-art solutions to interface power system and ICT simulators. Due to their prominence in recent research, a special focus is set on co-simulation approaches and their challenges and potentials. Further, two case studies analyzing the impact of ICT on applications in power system operation illustrate the necessity of a holistic approach and show the capabilities of state-of-the-art co-simulation platforms.
  •  
42.
  • Qiang, Xiaoyu, et al. (author)
  • Hybrid precoding for Integrated Communications and Localization in Massive MIMO LEO Satellite Systems
  • 2023
  • In: ICC 2023 - IEEE International Conference on Communications. - Piscataway, NJ : IEEE. - 9781538674628 ; 2023-May, s. 3540-3545
  • Conference paper (peer-reviewed)abstract
    • The future sixth generation (6G) networks will feature great importance on the integration of communications and localization, to realize the Internet of Everything (IoE). In this paper, we investigate the hybrid precoding design for the integrated communications and localization (ICAL) in the massive multiple-input multiple-output (MIMO) low Earth orbit (LEO) systems. In particular, we first derive an upper bound of the communication spectral efficiency (SE) and the squared position error bound (SPEB) of localization. Then, we formulate a multi-objective optimization problem to simultaneously operate communications and localization. Simulation results demonstrate the satisfactory performance of the proposed massive MIMO LEO ICAL system for typical setups. © 2023 IEEE.
  •  
43.
  • Trevisan, Silvia, et al. (author)
  • A study of metallic coatings on ceramic particles for thermal emissivity control and effective thermal conductivity enhancement in packed bed thermal energy storage
  • 2022
  • In: Solar Energy Materials and Solar Cells. - : Elsevier BV. - 0927-0248 .- 1879-3398. ; 234
  • Journal article (peer-reviewed)abstract
    • Ceramic particles-based packed bed systems are attracting the interest from various high-temperature applications such as thermal energy storage, nuclear cooling reactors, and catalytic support structures. Considering that these systems work above 600 ◦C, thermal radiation becomes significant or even the major heat transfer mechanism. The use of coatings with different thermal and optical properties could represent a way to tune and enhance the thermodynamic performances of the packed bed systems. In this study, the thermal stability of several metallic (Inconel, Nitinol, and Stainless Steel) based coatings is investigated at both high temperature and cyclic thermal conditions. Consequently, the optical properties and their temperature dependence are measured. The results show that both Nitinol and Stainless Steel coatings have excellent thermal stability at temperatures as high as 1000 ◦C and after multiple thermal cycles. Contrarily, Inconel (particularly 625) based coatings show abundant coating degradation. The investigated coatings also offer a wide range of thermal emissivity (between0.6 and 0.9 in the temperature range of 400–1000 ◦C), and variable trends against increasing temperature. This work is a stepping-stone towards further detailed experimental and modelling studies on the heat transfer enhancement in different ceramic-based packed bed applications through using metallic coatings.
  •  
44.
  • Wang, Lihui, et al. (author)
  • Assembly operator training and process planning via virtual systems
  • 2011
  • In: International Journal of Sustainable Engineering. - : Taylor & Francis. - 1939-7038 .- 1939-7046. ; 4:1, s. 57-67
  • Journal article (peer-reviewed)abstract
    • In this paper, we present an integrated intuitive system for assembly operators training and assembly process planning by combining virtual reality with motion-tracking technologies. The developed conceptual prototype for assembly planning and training enables individuals to interact with a virtual environment in real time. It extends the new technologies of motion tracking and integrates them with virtual environment technologies to create real-time virtual work cell simulations in which assembly operators may be immersed with hands-on experiences. In addition to operators training, the experimental results to date are presented to demonstrate the potential contributions of human skills in achieving effective assembly planning including disassembly operations. It is expected that this approach will lead to environment-friendly and sustainable operations by conserving energy and cost that are first tested in a human-emerged virtual system.
  •  
45.
  • Wang, Xiaoyu, et al. (author)
  • A Novel Output-Constrained Controller for DC/DC Buck Converter Feeding Constant Power Loads in DC Microgrids
  • 2023
  • In: IECON 2023 - 49th Annual Conference of the IEEE Industrial Electronics Society. - : Institute of Electrical and Electronics Engineers (IEEE).
  • Conference paper (peer-reviewed)abstract
    • DC microgrids have emerged as a promising solution for efficient and reliable electricity distribution. In DC microgrids, when power electronic loads and motor drives are tightly regulated, they behave as constant power loads (CPLs) and may lead to the instability issue. In this paper, a novel output-constrained controller for the DC/DC buck converter feeding CPLs is proposed. By introducing the output-constrained technique into the backstepping method, the proposed control scheme can keep the DC bus working within the pre-specific boundary even when large-signal disturbances happen. Relevant theoretical analyses are conducted by employing Laypunov stability theorem. Simulations in Matlab/Simulink are presented to verify the proposed controller.
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46.
  • Wang, Xiaoyu, et al. (author)
  • Associations of Insomnia With Insulin Resistance Traits : A Cross-sectional and Mendelian Randomization Study
  • 2023
  • In: Journal of Clinical Endocrinology and Metabolism. - : Endocrine Society. - 0021-972X .- 1945-7197. ; 108:8, s. e574-e582
  • Journal article (peer-reviewed)abstract
    • Context: Insomnia is associated with insulin resistance (IR) in observational studies; however, whether insomnia is causally associated with IR remains unestablished.Objective: This study aims to estimate the causal associations of insomnia with IR and its related traits.Methods: In primary analyses, multivariable regression (MVR) and 1-sample Mendelian randomization (1SMR) analyses were performed to estimate the associations of insomnia with IR (triglyceride-glucose index and triglyceride to high-density lipoprotein cholesterol [TG/HDL-C] ratio) and its related traits (glucose level, TG, and HDL-C) in the UK Biobank. Thereafter, 2-sample MR (2SMR) analyses were used to validate the findings from primary analyses. Finally, the potential mediating effects of IR on the pathway of insomnia giving rise to type 2 diabetes (T2D) were examined using a 2-step MR design.Results: Across the MVR, 1SMR, and their sensitivity analyses, we found consistent evidence suggesting that more frequent insomnia symptoms were significantly associated with higher values of triglyceride-glucose index (MVR, beta = 0.024, P < 2.00E-16; 1SMR, beta = 0.343, P < 2.00E-16), TG/HDL-C ratio (MVR, beta = 0.016, P = 1.75E-13; 1SMR, beta = 0.445, P < 2.00E-16), and TG level (MVR, beta = 0.019 log mg/dL, P < 2.00E-16, 1SMR: beta = 0.289 log mg/dL, P < 2.00E-16) after Bonferroni adjustment. Similar evidence was obtained by using 2SMR, and mediation analysis suggested that about one-quarter (25.21%) of the association between insomnia symptoms and T2D was mediated by IR.Conclusions: This study provides robust evidence supporting that more frequent insomnia symptoms are associated with IR and its related traits across different angles. These findings indicate that insomnia symptoms can be served as a promising target to improve IR and prevent subsequent T2D.
  •  
47.
  • Wang, Xiaoyu, et al. (author)
  • Generalized Polyak Step Size for First Order Optimization with Momentum
  • 2023
  • In: Proceedings of the 40th International Conference on Machine Learning, ICML 2023. - : ML Research Press. ; , s. 35836-35863
  • Conference paper (peer-reviewed)abstract
    • In machine learning applications, it is well known that carefully designed learning rate (step size) schedules can significantly improve the convergence of commonly used first-order optimization algorithms. Therefore how to set step size adaptively becomes an important research question. A popular and effective method is the Polyak step size, which sets step size adaptively for gradient descent or stochastic gradient descent without the need to estimate the smoothness parameter of the objective function. However, there has not been a principled way to generalize the Polyak step size for algorithms with momentum accelerations. This paper presents a general framework to set the learning rate adaptively for first-order optimization methods with momentum, motivated by the derivation of Polyak step size. It is shown that the resulting techniques are much less sensitive to the choice of momentum parameter and may avoid the oscillation of the heavy-ball method on ill-conditioned problems. These adaptive step sizes are further extended to the stochastic settings, which are attractive choices for stochastic gradient descent with momentum. Our methods are demonstrated to be more effective for stochastic gradient methods than prior adaptive step size algorithms in large-scale machine learning tasks.
  •  
48.
  • Wang, Xiaoyu, et al. (author)
  • On the Convergence of Step Decay Step-Size for Stochastic Optimization
  • 2021
  • In: Advances in Neural Information Processing Systems. - : Neural information processing systems foundation. ; , s. 14226-14238
  • Conference paper (peer-reviewed)abstract
    • The convergence of stochastic gradient descent is highly dependent on the step-size, especially on non-convex problems such as neural network training. Step decay step-size schedules (constant and then cut) are widely used in practice because of their excellent convergence and generalization qualities, but their theoretical properties are not yet well understood. We provide convergence results for step decay in the non-convex regime, ensuring that the gradient norm vanishes at an O(ln T /√T) rate. We also provide near-optimal (and sometimes provably tight) convergence guarantees for general, possibly non-smooth, convex and strongly convex problems. The practical efficiency of the step decay step-size is demonstrated in several large-scale deep neural network training tasks. 
  •  
49.
  • Wang, Xiaoyu, et al. (author)
  • On the Convergence of Step Decay Step-Size for Stochastic Optimization
  • 2021
  • In: Advances in Neural Information Processing Systems 34 (NeurIPS 2021). - 9781713845393 ; , s. 14226-14238
  • Conference paper (peer-reviewed)abstract
    • The convergence of stochastic gradient descent is highly dependent on the step-size, especially on non-convex problems such as neural network training. Step decay step-size schedules (constant and then cut) are widely used in practice because of their excellent convergence and generalization qualities, but their theoretical properties are not yet well understood. We provide the convergence results for step decay in the non-convex regime, ensuring that the gradient norm vanishes at an O(ln T /√T ) rate. We also provide the convergence guarantees for general (possibly non-smooth) convex problems, ensuring an O(ln T /√T ) convergence rate. Finally, in the strongly convex case, we establish an O(ln T /T ) rate for smooth problems, which we also prove to be tight, and an O(ln2 T /T ) rate without the smoothness assumption. We illustrate the practical efficiency of the step decay step-size in several large scale deep neural network training tasks.
  •  
50.
  • Wang, Y., et al. (author)
  • Feasibility study of pico cellular-relaying system in urban outdoor environment
  • 2011
  • In: 2011 IEEE 12th Annual Wireless and Microwave Technology Conference, WAMICON. - 9781612840819
  • Conference paper (peer-reviewed)abstract
    • Heterogeneous networks, in particular cellular-relaying networks, have the potential to provide high data-rate services at low infrastructure costs. Macro and micro base stations have traditionally been used to provide coverage and capacity, respectively. In this paper, we analyze a new approach in which coverage is provided by means of inband relays. We show that compared with a traditional network based on macro base stations, a good outdoor coverage for a target data rate could be provided in a more cost efficient way by deploying a network based on pico base stations and relays. However, this is valid only for low data-rate because part of the spectrum is allocated to the backhaul and therefore the capacity of cellular-relaying networks is typically limited. Moreover, this break-even point depends on how the networks are deployed.
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