•A multi-modal network (M2FNet) is proposed for object detection over all lighting conditions.•The M2FNet improves the accuracy of object detection by 25.6 % for the low-light condition.•Eight ...thresholds of illumination range are identified to determine the optimal modal.
Fusing multi-modal information from visible (VIS) and thermal infrared (TIR) images is crucial for object detection in fully adapting to varied lighting conditions. However, the existing models usually treat VIS and TIR images as independent information and extract corresponding features from separate networks due to the scarcity of training data with labeled instances from both VIS and TIR registration images. To fill this gap, a novel Multi-Modal Fusion NETwork (M2FNet) based on the Transformer architecture is proposed in this paper, which contains two effective modules: the Union-Modal Attention (UMA) and the Cross-Modal Attention (CMA). The UMA module aggregates multi-spectral features from VIS and TIR images and then extracts multi-modal features via a convolutional neural network (CNN) backbone. The CMA module is designed to learn cross-attention features from VIS and TIR pairwise features by Transformer architecture. Evaluation results by the mean average precision (mAP) metric show that the M2FNet method significantly advances the baseline methods trained using only VIS or TIR images by 10.71 % and 2.97 %, respectively. The increments in mAP are observed in the M2FNet method compared with the existing multi-modal methods on two public datasets. Sensitivity analysis of eight illumination thresholds shows that the M2FNet method presents robustness performance on varied illumination conditions and achieves the maximum increase in accuracy of 25.6 %. Moreover, this method is subsequently applied to a new testing dataset, VI2DA (Visible-Infrared paired Video and Image DAtaset), observed by diverse sensors and platforms for testing the generalization ability of object detectors, which will be publicly available at https://github.com/TIR-OD/Datasets.
Conventional wavelet transform (WT) filters have less effect on de-noising and correction of a north-seeking gyroscope sensor exposed to vibration, since the optimal wavelet decomposed level for ...de-noising is difficult to determine. To solve this problem, this paper proposes an optimized WT filter which is suited to the magnetic levitation gyroscope (GAT). The proposed method was tested on an equivalent mock-up network of the tunnels associated with the Hong Kong‒Zhuhai‒Macau Bridge. The gyro-observed signals exposed to vibration were collected in our experiment, and the empirical values of the optimal wavelet decomposed levels (from 6 to 10) for observed signals were constrained and validated by the high-precision Global Navigation Satellite System (GNSS) network. The result shows that the lateral breakthrough error of the tunnel was reduced from 12.1 to 3.8 mm with a ratio of 68.7%, which suggests that the method is able to correct the abnormal signal of a north-seeking gyroscope sensor exposed to vibration.
Senescence restricts the development of applications involving mesenchymal stem cells (MSCs) in research fields, such as tissue engineering, and stem cell therapeutic strategies. Understanding the ...mechanisms underlying natural aging processes may contribute to the development of novel approaches to preventing age-related diseases or slowing individual aging processes. Nampt is a rate-limiting NAD biosynthetic enzyme that plays critical roles in energy metabolism, cell senescence and maintaining life spans. However, it remains unknown whether Nampt influences stem cell senescence. In this study, the function of Nampt was investigated using a rat model of natural aging. Our data show that Nampt expression was significantly lower in MSCs obtained from aged rats than in those obtained from young rats during physiological aging. Reducing the level of Nampt in aged MSCs resulted in lower intracellular concentrations of NAD+ and downregulated Sirt1 expression and activity. After the Nampt inhibitor FK866 was added, young MSCs were induced to become aged cells. The enhanced senescence was correlated with NAD+ depletion and Sirt1 activity attenuation. In addition, Nampt overexpression attenuated cell senescence in aged MSCs. Our findings provide a new explanation for the mechanisms underlying stem cell senescence and a novel target for delaying stem cell senescence and preventing and treating age-related diseases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Interictal epileptiform spike (referred to as spike) detected from electroencephalograms lasting only 20- to 200-ms can provide a reliable evidence-based indicator for clinical seizure type ...diagnosis. Recent feature representation approaches focus either on the concrete-level or abstract-level information mining of the spike, thus demonstrating suboptimal detection performance. Additionally, existing abstract-level information mining methods of the spike based deep learning networks have not realized the effective feature representation of long-term dependent distinguished information within similar waveform cycles caused by morphological heterogeneity, which affects detection performance. Thus, a multilevel feature learning method for accurate spike detection was proposed in this study. Specifically, the spatio-temporal-frequency multidomain information in concrete-level first are inferred the common mimetic properties of the spike using the multidomain feature extractors. Then, the effective feature representation of long-term dependent distinguished information within similar waveform cycles caused by morphological heterogeneity is suitably captured using the temporal convolutional network. Finally, the spatio-temporal-frequency multidomain long-term dependent feature representation of spike is calculated using the element-wise manner to fuse the feature representation in concrete- and abstract-levels. The experimental results indicate that the proposed method can achieve an accuracy of 90.62±1.38%, sensitivity of 90.38±1.52%, specificity of 91.00±1.60%, precision of 90.33±4.71%, and the false detection rate per minute is <inline-formula> <tex-math notation="LaTeX">0.148\pm 0.020\text{m}^{-1} </tex-math></inline-formula>, which are higher than when using the feature representation in the concrete-or abstract-level alone. Additionally, the detection results indicate that the proposed method avoids the subjectivity and inefficiency of visual inspection, and it enables a highly accurate detection of the spike.
Rechargeable magnesium batteries (RMBs) are promising candidates to replace currently commercialized lithium‐ion batteries (LIBs) in large‐scale energy storage applications owing to their merits of ...abundant resources, low cost, high theoretical volumetric capacity, etc. However, the development of RMBs is still facing great challenges including the incompatibility of the electrolyte and the lack of suitable cathode materials with high reversible capacity and fast kinetics of Mg2+. While tremendous efforts have been made to explore compatible electrolytes and appropriate electrode materials, the rational design of unconventional Mg‐based battery systems is another effective strategy for achieving high electrochemical performance. This review specifically discusses the recent research progress of various Mg‐based battery systems. First, the optimization of electrolyte and electrode materials for conventional RMBs is briefly discussed. Furthermore, various Mg‐based battery systems, including Mg‐chalcogen (S, Se, Te) batteries, Mg‐halogen (Br2, I2) batteries, hybrid‐ion batteries, and Mg‐based dual‐ion batteries are systematically summarized. This review aims to provide a comprehensive understanding of different Mg‐based battery systems, which can inspire latecomers to explore new strategies for the development of high‐performance and practically available RMBs.
This review specifically presents current progress on recently developed rechargeable magnesium batteries, including Mg‐chalcogen batteries, Mg‐halogen batteries, hybrid ion batteries, and dual‐ion batteries. Additionally, challenges and potential solutions for these battery systems are proposed. This review aims to show new strategies for the development of high‐performance and practically available magnesium batteries.
Catalyst is the key to effective selective catalytic reduction of nitrogen oxide, and developing catalyst is always one of the hottest topics in both field of industry and academy. In order to ...realize an industrial application, one catalyst must grow on a specific support. However, seldom work compared the difference of catalyst growth with or without support. In this work, Mn2+ growth on cordierite (a typical commercial catalyst support) was investigated. The formed active species were detailedly characterized. As a result, orthorhombic cordierite guided Mn2+ to form orthorhombic oxide (γ-MnO2). In comparison, Mn2+ preferred to form tetragonal β-MnO2 without the guide of cordierite. During the synthesis, cordierite and citric acid promoted γ-MnO2 dispersion, increased growth of exposed (301) facet, and created lattice distortion between (301) and (101) planes. β-MnO2 mainly exposed (101) facet. The best catalyst was γ-MnO2, which was mostly dominated by (301) facet and had an obvious lattice distortion from 75° to 78° between (301) and (101) planes. In comparison, 0.1 g of the γ-MnO2 reached a catalytic conversion rate 1.6 times bigger than 1.0 g of β-MnO2 at 250 °C. This work helps to understand guiding effect of support on formed catalytic species, which is in favor of developing effective commercial catalysts for environmental pollutants.
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•Mn2+ prefers to form tetragonal β-MnO2 without the guide of cordierite.•Cordierite guides Mn2+ to form orthorhombic γ-MnO2.•γ-MnO2 mainly exposes (301) facet.•γ-MnO2 also has lattice distortion between (301) and (101) planes.•Catalytic activity of 0.1 g γ-MnO2 is 1.6 times bigger than 1.0 g of β-MnO2 at 250 °C.
Microbiologically induced calcite precipitation (MICP) technology shows potential for remediating heavy metal pollution; however, the underlying mechanism of heavy metal mineralization is not ...well-understood, limiting the application of this technology. In this study, we targeted Cd contamination (using 15:1, 25:1, and 50:1 Ca2+/Cd2+ molar ratios) and showed that the ureolytic bacteria Sporosarcina ureilytica ML-2 removed >99.7 % Cd2+ with a maximum fixation capacity of 75.61 mg-Cd/g-CaCO3 and maximum precipitation production capacity of 135.99 mg-CaCO3/mg-cells. Quantitative PCR analysis showed that Cd2+ inhibited the expression of urease genes (ureC, ureE, ureF, and ureG) by 70 % in the ML-2 strain. Additionally, the pseudo-first-order kinetics model (R2 = 0.9886), intraparticle diffusion model (R2 = 0.9972), and Temkin isotherm model (R2 = 0.9828) described the immobilization process of Cd2+ by bio calcite in MICP-Cd system. The three Cd2+ mineralization products generated by MICP were attributed to surface precipitation (Cd2+ → Cd(OH)2), direct binding with the CO32−/substitution calcium site of calcite (Cd2+ → CdCO3, otavite), and calcite lattice vacancy anchors (Cd2+ → (CaxCd1-x)CO3). Our findings improve the understanding of the mechanisms by which MICP can achieve in situ stabilization of heavy metals.
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•Maximum mineralized capacity reached 75.61 mg-Cd/g-CaCO3 by MICP at 24 h.•Maximum precipitation yield induced by ML-2 strain was 135 mg-CaCO3/mg-cell.•qPCR revealed the effect of Cd2+ on the key genes of urease metabolism.•The adoption kinetics and isotherm models of calcite fixed Cd2+ were verified.•Three chemical species of mineralizing Cd2+ by MICP were demonstrated.
The pH-responsive controlled release of Boscalid with low toxicity.
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•18% Boscalid has been loaded in ZIF-67 nanocarriers with large pore size.•Release of Boscalid@ZIF-67 can be ...triggered in acid condition.•Boscalid@ZIF-67 exhibits remarkable antifungal effect over Botrytis cinerea.
Pesticides have been always restricted by poor efficacy and inacceptable toxicity. In this work, a pH-sensitive controlled-release nano-capsule of fungicide, Boscalid@ZIF-67 (ZIF is a subclass of MOF), was prepared based on metal–organic framework (MOF) for higher antifungal effect and low bio-toxicity. The Boscalid@ZIF-67 was formed by physical adsorption method and it possesses uniform size and dodecahedral shape. The loading ratio is as high as 18%. In addition, the release of fungicide Boscalid showed pH sensitive response due to the weak acidic group in the MOF structure, in which the rate of release was more rapid under acid condition (＜7). Cumulative release rate release was higher about 25% and 38% adjusted from 7 to 3.5 and from 7 to 5.5 on the 6th day than that under neutral condition. At the early stage of infecting the host plant, Botrytis cinerea will produce more acidic substances such as oxalic acid, which are conducive to Boscalid@ZIF-67 disintegration for rapid release of Boscalid. Meanwhile, the antifungal effect of Boscalid@ZIF-67 was 4–6 times more of that commercially available product on Botrytis cinerea, while the bio-toxicity under the same condition is much lower than that of latter. Thus, this work not only proves that Boscalid@ZIF-67 could be used as nanoparticles platform for smart control over Botrytis cinerea, but also has great potential to improve traditional modalities by addressing the crop diseases in economic and ecological manner.
Despite impressive merits of complementary charge‐storage mechanisms for aqueous Zn‐ion hybrid micro‐supercapacitors (ZHMSCs), it remains a challenge to solve dendrite and parasitic reactions issues ...of Zn anodes. Herein, a kinetics‐boosted strategy of Zn2+ transport and desolvation of hydrated Zn2+ is proposed by engineering zwitterionic P(AM‐co‐SBMA) hydrogel electrolyte (PASHE) for highly reversible Zn plating/stripping. Mechanically robust and chemically anchored PASHE features zwitterionic groups for constructing ion migration channels and immobilizing water molecules, which accelerates Zn2+ migration for an ultrahigh transfer number (0.84) and alleviates water‐related parasitic reactions. Theoretical calculations combined with experimental results reveal that sulfobetaine sulfonate anions endow PASHE with improved desolvation kinetics and the ability to coordinate Zn2+ flux and electric field distributions at the electrolyte–electrode interface. Thus, Zn anodes exhibit excellent electrochemical performance involving high average coulombic efficiency of 99.4% in Zn|PASHE|Cu cell as well as high cumulative capacity of 2000 mAh cm−2 (20 mA cm−2, 1 mAh cm−2) and depth of discharge of 80.9% (20 mA cm−2, 10 mAh cm−2) in Zn|PASHE|Zn cells. Furthermore, ZHMSCs based on PASHE deliver excellent flexibility and cyclability for energy‐storage applications. This work provides useful insights on hydrogel electrolyte engineering for developing high‐performance Zn anodes and derived energy‐storage devices.
A mechanically robust zwitterionic hydrogel electrolyte with improved Zn2+ transport and hydrated Zn2+ desolvation kinetics and reduced water activity is developed, enabling dendrite‐free and parasitic reactions‐inhibited Zn anode with highly reversible plating/stripping. Due to these advantages, Zn‐ion hybrid micro‐supercapacitors with this zwitterionic hydrogel electrolyte achieve excellent flexibility and cyclability for wearable energy‐storage applications.
Dynamic variations in chemical composition and size distribution of dissolved copper (Cu) along the river-sea interface in the Yellow River Estuary (China) were investigated. On average, ~64% and ~8% ...of bulk dissolved Cu (<0.45 μm) were partitioned in the <1 kDa fraction and 1–100 kDa, respectively. The other 28% were in the 100 kDa–0.45 μm colloids, which indicates that this fraction may dominate the overall morphology of colloidal Cu. The <3 kDa Cu fraction was susceptible to environmental parameters and the >3 kDa fraction was related to the behavior of dissolved organic carbon. 1–100 kDa Cu migrated more violently than >100 kDa Cu and tended to be a stable polymer, with stability increasing towards the sea. The source of <1 kDa Cu was complex and may be supplemented by the decomposition of small molecular colloids and the addition of the sediments or particles ligands.
•Colloidal Cu heterogeneity in size and variation was studied in the YRE.•LMW-Cu migrated more violently than HMW-Cu and stabilized with increasing salinity.•<1 kDa Cu was double supplemented from LMW decomposition and particulate ligands addition.•Strong ligand, mixing process and desorption co-regulated colloidal Cu of the YRE.
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