Engineering Spin States of Isolated Copper Species in a Metal-Organic Framework Improves Urea Electrosynthesis

The catalytic activities are generally believed to be relevant to the electronic states of their active center, but understanding this relationship is usually difficult. Here, we design two types of catalysts for electrocatalytic urea via a coordination strategy in a metal–organic frameworks: Cu^(Ⅲ)-HHTP and Cu^(Ⅱ)-HHTP. Cu^(Ⅲ)-HHTP exhibits an improved urea production rate of 7.78 mmol h^(−1)g^(−1) and an enhanced Faradaic efficiency of 23.09% at-0.6 V vs. reversible hydrogen electrode, in sharp contrast to Cu^(Ⅱ)-HHTP.Isolated CuⅢspecies with S = 0 spin ground state are demonstrated as the active center in Cu^(Ⅲ)-HHTP, different from Cu^(Ⅱ) with S = 1/2 in Cu^(Ⅱ)-HHTP. We further demonstrate that isolated Cu^(Ⅲ)with an empty dx2-y20orbital in Cu^(Ⅲ)-HHTP experiences a single-electron migration path with a lower energy barrier in the C–N coupling process, while Cu^(Ⅱ)with a single-spin state( d_(x2-y2)^(1)) in Cu^(Ⅱ)-HHTP undergoes a two-electron migration pathway.

End-to-End Joint Multi-Object Detection and Tracking for Intelligent Transportation Systems

Environment perception is one of the most critical technology of intelligent transportation systems(ITS).Motion interaction between multiple vehicles in ITS makes it important to perform multi-object tracking(MOT).However,most existing MOT algorithms follow the tracking-by-detection framework,which separates detection and tracking into two independent segments and limit the global efciency.Recently,a few algorithms have combined feature extraction into one network;however,the tracking portion continues to rely on data association,and requires com‑plex post-processing for life cycle management.Those methods do not combine detection and tracking efciently.This paper presents a novel network to realize joint multi-object detection and tracking in an end-to-end manner for ITS,named as global correlation network(GCNet).Unlike most object detection methods,GCNet introduces a global correlation layer for regression of absolute size and coordinates of bounding boxes,instead of ofsetting predictions.The pipeline of detection and tracking in GCNet is conceptually simple,and does not require compli‑cated tracking strategies such as non-maximum suppression and data association.GCNet was evaluated on a multivehicle tracking dataset,UA-DETRAC,demonstrating promising performance compared to state-of-the-art detectors and trackers.

MSF-Net: A Multilevel Spatiotemporal Feature Fusion Network Combines Attention for Action Recognition

An action recognition network that combines multi-level spatiotemporal feature fusion with an attention mechanism is proposed as a solution to the issues of single spatiotemporal feature scale extraction,information redundancy,and insufficient extraction of frequency domain information in channels in 3D convolutional neural networks.Firstly,based on 3D CNN,this paper designs a new multilevel spatiotemporal feature fusion(MSF)structure,which is embedded in the network model,mainly through multilevel spatiotemporal feature separation,splicing and fusion,to achieve the fusion of spatial perceptual fields and short-medium-long time series information at different scales with reduced network parameters;In the second step,a multi-frequency channel and spatiotemporal attention module(FSAM)is introduced to assign different frequency features and spatiotemporal features in the channels are assigned corresponding weights to reduce the information redundancy of the feature maps.Finally,we embed the proposed method into the R3D model,which replaced the 2D convolutional filters in the 2D Resnet with 3D convolutional filters and conduct extensive experimental validation on the small and medium-sized dataset UCF101 and the largesized dataset Kinetics-400.The findings revealed that our model increased the recognition accuracy on both datasets.Results on the UCF101 dataset,in particular,demonstrate that our model outperforms R3D in terms of a maximum recognition accuracy improvement of 7.2%while using 34.2%fewer parameters.The MSF and FSAM are migrated to another traditional 3D action recognition model named C3D for application testing.The test results based on UCF101 show that the recognition accuracy is improved by 8.9%,proving the strong generalization ability and universality of the method in this paper.

氧化石墨烯共价杂化水基聚氨酯电沉积树脂的制备及性能

采用超声波辅助反应技术,实现了甲苯二异氰酸酯(TDI)对氧化石墨烯(GO)的改性,成功制备了异氰酸酯共价改性的NCO@GO碳材料。采用原位聚合法制备出GO共价杂化水性聚氨酯,并与交联剂混合后得到聚氨酯(PU)电沉积涂料。利用红外光谱分析了GO改性前后及GO/PU电沉积树脂的特征官能团,用热失重研究了GO/PU电沉积树脂的热稳定性,X射线衍射研究了GO/PU电沉积树脂中GO层间效应,透射电子显微镜表征了GO/PU电沉积树脂的形态,电导率仪测试了漆膜的导电率,研究了氧化石墨烯含量对聚氨酯漆膜外观和性能的影响。结果表明,随着GO含量的增加,水性聚氨酯漆膜的导电性、光泽度、硬度和耐酸性表现出先增大后降低的规律。当石墨烯的质量分数为0.75%时,石墨烯在水性聚氨酯树脂及其乳液中具有较好的分散性,漆膜的导电性、光泽度、硬度和耐酸性等性能达到最佳。

Accumulation of residual soil microbial carbon in Chinese fir plantation soils after nitrogen and phosphorus additions

Nitrogen(N) and phosphorus(P) additions can affect soil microbial carbon(C) accumulation.However,the mechanisms that drive the changes in residual microbial C that occur after N and P additions have not been well-defined for Chinese fir plantations in subtropical China.We set up six different treatments, viz.a control(CK), two N treatments(N_1: 50 kg ha^(-1) a^(-1); N2:100 kg ha^(-1) a^(-1)), one P treatment(P: 50 kg ha^(-1) a^(-1)),and two combined N and P treatments(N_1P:50 kg ha^(-1) a^(-1) of N+50 kg ha^(-1) a^(-1) of P; N_2P:100 kg ha^(-1) a^(-1) of N+50 kg ha^(-1) a^(-1) of P).We then investigated the influences of N and P additions on residual microbial C.The results showed that soil pH and microbial biomass decreased after N additions, while microbial biomass increased after P additions.Soil organic carbon(SOC) and residual microbial C contents increased in the N and P treatments but not in the control.Residual microbial C accumulation varied according to treatment and declined in the order: N_2P>N_1P>N2>N_1>P>CK.Residual microbial C contents were positively correlated with available N, P, and SOC contents, but were negatively correlated with soil p H.The ratio of residual fungal C to residual bacterial C increased under P additions, but declined under combined N+P additions.The ratio of residual microbial C to SOC increased from 11 to 14%under the N_1P and N_2P treatments, respectively.Our results suggest that the concentrations of residual microbial C and the stability of SOC would increase under combined applications of N and P fertilizers in subtropical Chinese fir plantation soils.

File Wallet:A File Management System Based on IPFS and Hyperledger Fabric

Online file management systems enable cooperatively editing and sharing.However,due to the cost of communication and storage infrastructures,traditional online file management services,e.g.,Google Drive and OneDrive,usually provide limited storage space and relatively low download speed for free users.To achieve better performance,ordinary users have to purchase their expensive services.Moreover,these file management systems are based on centralized architecture and bear the privacy leakage risk,because users’personal files are stored and controlled by their servers.To address the above problems,we propose a peer-to-peer(P2P)file management system based on IPFS and Hyperledger Fabric,named as FileWallet,which can serve as a personal wallet for individual users or organizations to store and share their files in a secure manner.In FileWallet,the users form a P2P network and a Fabric network,where P2P network builds the connections and distributed storage network and the Fabric network sustains consistent blockchain ledgers to record file operation related transactions.In our FileWallet,the storage and communication costs are mitigated in the decentralized design,and the file owner can fully control the access permission of the file to preserve the file privacy.The design of the system architecture,main functionalities,and system implementations are presented in this paper.The performance of the system is evaluated through experiments,and the experimental results show its wide applicability and scalability.

Effects of Ion Doping on the Optical Properties of Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSC) play a leading role in the third generation photovoltaics due to their low cost, easy fabrication process, high conversion efficiency and good stability. As a media of dye adsorption, electron transport, and electrolyte diffusion, the nanocrystalline semiconductor photoanode plays a key role during light-to-electricity conversion in DSC. This paper studies the influence of different ions doping and different concentration of ion doping on the electrical and optical properties of DSC, through the photoelectric property test of DSC. We learn that Zn2+ doped TiO2 photoanode is the best. At the same time there was an optimum doping concentration which was 0.05% (mole fraction).

The F5 gene predicts poor prognosis of patients with gastric cancer by promoting cell migration identified using a weighted gene co-expression network analysis

Distal gastric cancer(DGC)is a subgroup of gastric cancer(GC),which has different molecular characteristics from proximal gastric cancer(PGC).These differences result in different overall survival(OS)rates;however,data pertaining to the survival rate in PGC or DGC are contradictory.This suggests that the location of GC is not the unique cause of the different survival rates,while the molecular characteristics might be more important factors determining the prognosis of DGC.Therefore,the aim of this study was to discover key prognostic factors in DGC using bioinformatic methods and to explore the potential molecular mechanism.The Cancer Genome Atlas(TCGA)public database was employed to screen data relating to DGC,and we conducted a weighted gene co-expression network analysis(WGCNA)on DGC patient samples to establish co-expression modules.High-weight genes(hub genes)in a dominant color module were identified.In vitro experiments and gene set enrichment analyses(GSEA)were carried out to elucidate the potential molecular mechanism.In this study,139 DGC samples were enrolled to perform a co-expression analysis.According to the correlation between gene modules and clinical characteristics,the royal blue module related to stage M of DGC was screened,and a survival analysis was conducted to show that highcoagulation-factor V(F5)expression was related to the short OS of patients with GC.In vitro experiments confirmed that F5 could promote the migration of GC cells.GSEA suggested that F5 might have affected the prognosis of GC by modulating the activities of the Wnt and/or the TGF-βsignaling pathways.Our results indicated that high F5 expression predicts poor prognosis of patients with DGC,and it functions probably by promoting cell migration through the Wnt and/or the TGF-βsignaling pathways.

An insight into the in vivo imaging potential of curcumin analogues as fluorescence probes

Curcumin and its derivatives have good electrical and optical properties due to the highly symmetric structure of delocalized π electrons. Apart from that, curcumin and its derivatives can interact with numerous molecular targets, thereby exerting less side effects on human body. The fluorescence emission wavelength and fluorescence intensity of curcumin can be enhanced by modifying its π-conjugated system and β-diketone structure. Some curcumin-based fluorescent probes have been utilized to detect soluble/insoluble amyloid-β protein, intracranial reactive oxygen species, cysteine, cancer cells, etc. Based on the binding characteristics of curcumin-based fluorescent probes with various target molecules, the factors affecting the fluorescence intensity and emission wavelength of the probes are analyzed, in order to obtain a curcumin probe with higher sensitivity and selectivity. Such an approach will be greatly applicable to in vivo fluorescence imaging.

Effect of uninterrupted dabigatran or rivaroxaban on achieving ideal activated clotting time to heparin response during catheter ablation in patients with atrial fibrillation

BACKGROUND Uninterrupted use of oral anticoagulants before atrial fibrillation(AF)ablation can reduce the incidence of perioperative thromboembolic events.However,the effect of new oral anticoagulants on activated clotting time(ACT)in respo-nse to heparin during AF ablation in Chinese populations remains unknown.The aim of the present retrospective study was to investigate the value of ACTs in response to intraoperative heparin administration in patients using dabigatran or rivaroxaban.METHODS From January 2018 to December 2021,a total of 173 patients undergoing AF ablation were included in the study,in which 101 patients were treated with dabigatran,72 patients were treated with rivaroxaban.The intraoperative ACT values were examined in both groups.The incidence of periprocedural complications was evaluated.RESULTS Initial heparin dosage(88±19 U/kg vs.78±27 U/kg,P<0.05),total heparin dosage(137±41 U/kg vs.106±52 U/kg,P<0.05)during the ablation procedure were higher in the dabigatran group than those in the rivaroxaban group.Mean ACT(280±36 s vs.265±30 s,P<0.05),and the percentage of ACTs within the therapeutic range(250-350 s)(74%±26%vs.60%±29%,P<0.05)were significantly lower in the dabigatran group than those in the rivaroxaban group,particularly in male pati-ents.Furthermore,the average time of achieving the target ACT(250-350 s)was also found longer in the dabigatran group(P<0.05)as compared with the rivaroxaban group.No significant difference was found in the incidence of periprocedural complica-tions between the two groups.CONCLUSIONS The anticoagulant effect of uninterrupted rivaroxaban therapy appears to be more stable and efficient than dabigatran administration during catheter ablation in patients with AF.

Study on Hydrogen Production System by Coupling with DSSCs

The consumption of dye-sensitized solar cells (DSSCs) used to produce hydrogen, compared with the traditional water-splitting energy, is much less. First of all it is because of DSSCs’ low cost, easy fabrication process, high conversion efficiency and good stability;secondly it also solves the problem of serious corrosion of the electrode, for the entire solar system is in the air. We use three tandem dye-sensitized photovoltaic cells as a source of power;the open circuit voltage of photoelectric unit shows the feasibility of using dye-sensitized photovoltaic cell decomposition of water to produce hydrogen.

Correlation between SP-D content in cerebrospinal fluid and severity of viral encephalitis

Objective:To detect the content of SP-D in cerebrospinal fluid(CSF) of children with viral encephalitis, evaluate the correlation between SP-D and indexes of brain injury, inflammatory reaction and cellular immune disorder.Methods: 78 cases of viral encephalitis children diagnosed in our hospital during December 2016 to May 2018 were selected as Viral encephalitis group, 51 cases of fever without intracranial infection children were selected as Control group. The cerebrospinal fluid samples of two groups were taken and SP-D, brain injury-related indicators, inflammatory indicators and T lymphocyte subsets were detected. Pearson test was used to analyze the relationship between SP-D content in CSF and above indicators.Results: Content of SP-D in CSF of Viral encephalitis group was lower than that of control group (P<0.05). Contents of MBP, CK-BB, NSE and S100B in CSF of Viral encephalitis group were higher than those of Control group;contents of IL-1β, TNF-αand ICAM-1 in CSF of Viral encephalitis group were higher than those of Control group;distribution proportion of CD3+, CD4+ T lymphocytes and CD4+/CD8+ ratio in CSF were lower than those of Control group, and levels of CD8+ were higher than that of Control group (P<0.05). Correlation analysis showed that, SP-D content in CSF of viral encephalitis children was directly related to brain injury indexes, inflammatory indexes and T lymphocyte subsets distribution levels(P<0.05).Conclusion: Content of SP-D in CSF of viral encephalitis children decreases abnormally, the specific content is directly related to the degree of brain injury, intracranial inflammation and cellular immune dysfunction. It is important to evaluate the severity of the disease.

Detection of serum IgE and Eotaxin in asthma children and its clinical significance

Objective:To detect serum contents of IgE, Eotaxin and explore the relationship between serum IgE, Eotaxin and asthma severity.Methods: 140 cases of asthma children diagnosed in our hospital during January 2017 to March 2018 were chosen as Asthma group, 100 cases of healthy children vaccinated in our hospital at the same time were chosen as Normal control group. Serum contents of IgE, Eotaxin, inflammatory mediators and airway remodeling indexes were detected in two groups. Correlation analysis was used to evaluate the relationship between serum IgE, Eotaxin content and severity of asthma.Results: Serum contents of IgE and Eotaxin in Asthma group were significantly higher than those in Normal control group, and contents of IL-9, IL-17, IL-18 and IL-33 were higher than those in Normal control group, IL-35 was lower than that in Normal control group;serum contents of MMP-2, MMP-9, TGF-β and VEGF in Asthma group were significantly higher than those in Normal control group (P<0.05). Pearson test found that serum contents of IgE, Eotaxin in asthma children were positively correlated with inflammatory mediators such as IL-9, IL-17, IL-18, IL-33, negatively correlated with IL-35;positively correlated with airway remodeling indexes such as MMP-2, MMP-9, TGF-β and VEGF.Conclusion: Serum contents of IgE, Eotaxin in asthma children are significantly higher than those in normal children, and the specific contents were closely related to the degree of systemic inflammatory response and airway remodeling.

Designing Unpowered Shoulder Complex Exoskeleton via Contralateral Drive for Self-rehabilitation of Post-stroke Hemiparesis

Rehabilitation using exoskeleton robots can effectively remediate dysfunction and restore post-stroke survivors’ physical ability. However, low kinematic compatibility and poor self-participation of post-stroke patients in rehabilitation restrict the outcomes of exoskeleton-based therapy. The study presents an Unpowered Shoulder Complex Exoskeleton (USCE), consisting of Shoulder Girdle Mechanism (SGM), Ball-and-Socket Joint Mechanism (BSM), Gravity Compensating Mechanism (GCM) and Adjustable Alignment Design (AAD), to achieve self-rehabilitation of shoulder via energy transfer from the healthy upper limb to the affected counterpart of post-stroke hemiplegic patients. The SGM and AAD are designed to improve the kinematic compatibility by compensating for displacements of the glenohumeral joint with the adaptable size of USCE for different wearers. The BSM and GCM can transfer the body movement and energy from the healthy half of the body to the affected side without external energy input and enhance the self-participation with sick posture correction. The experimental results show that the USCE can provide high kinematic compatibility with 90.9% movement similarity between human and exoskeleton. Meanwhile, the motion ability of a post-stroke patient’s affected limb can be increased through energy transfer. It is expected that USCE can improve outcomes of home-based self-rehabilitation.

Episodic sandstone-type uranium mineralization in Asia during the Late Mesozoic-Cenozoic

Sandstone-type uranium deposits(STUDs) are the most important global source of uranium. However, it is unclear why STUDs have a non-random distribution in time and space. It is generally thought that STUDs are formed by the circulation of groundwater in sandstone rocks. The groundwater is typically oxidized and sourced from local precipitation, which suggests the regional climate may have a role in the formation of STUDs. The groundwater circulation is mainly affected by basin evolution, which means that regional tectonism may also control the formation of STUDs. In this study, the author examined STUDs in Asia, and compiled previously reported ages for STUDs and compared these with the uplift history of the major orehosting regions and the late Mesozoic–Cenozoic climatic evolution of Asia. Apart from a few uranium deposits in the Transural region, most of the STUDs in Asia were formed during the Late Cretaceous to Quaternary, and can be classified into three stages:Late Cretaceous–early Paleogene(80–50 Ma;stage I), Oligocene–mid-Miocene(25–17 Ma;stage Ⅱ), and late Miocene–present(8–0 Ma;stage Ⅲ). The formation of STUDs in Asia was closely related to regional uplift caused by India–Eurasia collision,subduction of oceanic plates, and increased humidity during greenhouse climate periods and intensification of the Asian Monsoon.

Highly sensitive humidity sensors based on hexagonal boron nitride nanosheets for contactless sensing

Humidity sensors with high sensitivity,rapid response,and facile fabrication process for contactless sensing applications have received considerable attention in recent years.Herein,humidity sensors based on hexagonal boron nitride(h-BN)nanosheets that are synthesized by a facile ultrasonic process have been fabricated,which display an ultrahigh sensitivity of 28,384%at 85%relative humidity(RH),rapid response/recovery time(3.0/5.5 s),and long-term stability in a wide humidity detection range(11%-85%RH),superior to most of the reported humidity sensors.The high sensitivity can be ascribed to the massive hydrophilic functional groups absorbed on the h-BN nanosheet surface.Benefiting from the high humidity sensing performances,contactless Morse code messaging and human writing and speech recognition have been demonstrated.This work demonstrates the great potential of the high-performance h-BN nanosheet-based humidity sensors for future contactless sensing devices.

Value of Coronary Sinus During Computed Tomography Pulmonary Angiography for Predicting Pulmonary Hypertension in Patients with Acute Pulmonary Embolism

Objective:Computed tomography pulmonary angiography(CTPA)parameters are valuable for predicting pulmonary hypertension(PH)in patients with pulmonary embolism(PE).However,few studies have used the coronary sinus ostium area(CSOA),derived from CTPA,to detect PH.This study aimed to compare the prognostic values of the CSOA,coronary sinus ostium diameter(CSOD),and right ventricular(RV)/left ventricular(LV)ratio for PH.Methods:This study retrospectively analyzed 78 patients(mean age,(51.94±12.33)years;53.8%male)with acute PE confirmed by CTPA at the Sixth and Eighth Medical Centers of the People’s Liberation Army General Hospital between June 2018 and June 2020.Patients were categorized into 2 groups using a pulmonary artery systolic pressure(PASP)cut-off of 30 mmHg.CTPA parameters were compared between these groups.Results:Patients with PASP>30 mmHg(n=22)had a larger CSOA,CSOD,RV diameter,RV/LV ratio,and inferior vena cava diameter compared with patients with PASP≤30 mmHg(n=56).The CSOA had an area under the receiver-operating characteristic curve(AUC,0.84;95%confidence interval(CI),0.74–0.94;P<0.001)similar to that of the RV/LV ratio(AUC,0.85;95%CI,0.73–0.99;P<0.001),while that of the CSOD was smaller(AUC,0.66;95%CI,0.51–0.81;P<0.05).Conclusion:Both CSOA and CSOD demonstrated a good ability to predict PH,while CSOA better predicted PASP>30 mmHg.

π-Pimer,π-Dimer,π-Trimer,and 1Dπ-Stacks in a Series of Benzene Triimide Radical Anions:Substituent-Modulated π Interactions and Physical Properties in Crystalline State

We herein present the efficient syntheses,crystal structures,and physical properties of a series of novel benzene triimide(BTI)radical anions,emphasizing the relationship between molecular structure with spin–spin intermolecular interactions and physical properties in the crystalline state.BTI radical crystals were preparedby reducingvarious substitutedBTIs(1)with cobaltocene(CoCp2),followed by sequential crystallization processes.Two isolable radical species,that is,neutral molecule-radical anion pair(2)and monoradical species(3),were obtained from BTIs bearing small substituents(ethyl and propyl),while for those bearing larger substituents(butyl,hexyl,and benzyl)sole monoradicals(3)were produced.The radical species showed diverse intermolecular stackings in the crystalline state referred to asπ-pimer,π-dimer,alternatingπ-trimer,and one-dimensional(1D)slippedπ-stacks depending on the length and size of the substituents.Different spin–spin interactions arising from the substituent-tuned radical packings were demonstrated by electron spin resonance(ESR)spectra.The structure–property relationshipwas studied in terms of magnetism and conductivity.The radicalπ-pimers andπ-stacks with effective charge transport exhibited paramagnetic property and conductivity feasibly at room temperature,whileπ-dimers andπ-trimers featuring thermally populated spin-triplet stateswere antiferromagnetic and nonconductive due to their strong radical–radical pairing effect.

Spin-Enhanced C-C Coupling in CO_(2)Electroreduction with Oxide-Derived Copper

Electrocatalytic reduction of carbon dioxide(CO_(2))to multicarbon(C2+)products involves intricate multiple protons and electron transfer of C-C coupling,which is dictated by not only the intrinsic reactivity but also the spin states of electrons in the catalyst.Here,we observe spin-enhanced CO_(2)reduction(CO_(2)RR)electrocatalytic activity on an oxidederived copper(OD-Cu)catalyst due to the existence of a specific Cu*site that carried the magnetic moments.Due to the correlation of magnetic and catalytic properties in OD-Cu,the current density through the OD-Cu electrode increases by nearly 10%at 350 mT.The field strength and angle dependence of such magnetic field effect(MFE),together with the time-resolved measurements proved that it originated from the alignment of magnetic moments on Cu*sites.The MFE on the electrocatalytic process enabled an enhancement(up to 15%)of the CO_(2)RR Faradaic efficiency using the OD-Cu catalyst.Importantly,the enhancement was attributed to the spinantiparallel alignment of electrons to promote C-C coupling on asymmetric Cu*-Cu sites;consequently,the optimal bias was reduced by∼0.2 V under the magnetic field for C2 products with Faradaic efficiency>30%and selectivity>75%.Our work uncovers a new paradigmfor spin-enhanced catalysis applicable to a broad range of chemical reactions involving spin singlet products.