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Understanding the stability and reactivity of silver clusters toward oxygen provides insights to design new materials of coinage metals with atomic precision. Herein, we report a systematic study o...

Anomaly detection for log sequences is a necessary task for system intelligent operation and fault diagnosis. In a log sequence, adjacent logs have the property of local correlation, while long-distance logs have remote dependencies. It is helpful to fully mine these information during modeling for improving the performance of anomaly detection. Meanwhile, there are some redundant information or noise in the log sequence, which has no contribution to the detection, and may even bring negative impact. The existing methods for log sequence anomaly detection do not take the above problems into account when constructing models. In this paper, we propose LSADNET, an unsupervised log sequence anomaly detection network based on local information extraction and globally sparse Transformer model. LSADNET applies multi-layer convolution to capture the local correlation between adjacent logs, and utilizes Transformer to learn the global dependency among long-distance logs. Meanwhile, we propose a globally sparse Transformer model to improve the self-attention mechanism, which can help to retain important information adaptively and eliminate the irrelevant information in the log sequence. In addition, according to the co-occurrence mode of log templates, we put forward the calculation formula of log template transfer value, and apply it to log vectorization. Through sufficient experiments on two public datasets, it is confirmed that LSADNET has better performance than the state-of-art methods.

Cyclotrimerization of acetylene to benzene has attracted significant interest, but the role of geometric and electronic effects on catalytic chemistry remains unclear. To fully elucidate the mechanism of catalytic acetylene-to-benzene conversion, we have performed a gas-phase reaction study of the Fen+, Con+, and Nin+ (n = 1-16) clusters with acetylene utilizing a customized mass spectrometer. It is found that their reactions with acetylene are initiated by C2H2 molecular adsorption and allow for dominant dehydrogenation with the relatively low partial pressure of the acetylene gas. However, at high acetylene concentrations, the cyclotrimerization in Mn+ + 3C2H2 (M = Fe, Co, Ni) becomes the dominant reaction channel. We demonstrate theoretically the favorable thermodynamics and reaction dynamics leading to the formation of the M+(C6H6) products. The results are discussed in terms of a cluster-catalyzed multimolecule synergistic effect and the cation-π interactions.

The tunneling mode of scanning electrochemical microscopy (SECM) was developed recently and applied to studies of charge-transfer reactions at single metal nanoparticles (NPs). When an SECM tip is ...

How hydroclimate will change in the future has been of great interest with the increasing concern of global warming. Acquirement of ample high-resolution proxy-based reconstructions will aid to answer such question by increasing the accuracy of climate prediction models. However, discrepancies among existing reconstructions in the southeast part of China (SEC) has aroused great uncertainty about the hydroclimatic conditions. Here we present an annually-resolved June–August scPDSI reconstruction and a June–July relative humidity reconstruction from 1876 to 2015 in the middle reaches of the Yangtz River, based on accurately-dated tree-ring materials. The reconstructions well reproduce the instrumental records, with explained variance of 48.82% and 46.79%. A secular wetting trend is found in the study area from 1876 to 2000, then it dried quickly. The driest (2006–2015) and wettest (1943–1955) periods both occurred after 1940, and 40% of the top 10 driest years occurred in the twenty-first century. Overall, an increasing intensified hydroclimatic variation is identified, especially significant in the recent decade. The historical summer hydroclimatic fluctuations, which were found closely related to the concurrent temperature variations, show broadly large spatial and temporal synchronicity with existing hydroclimatic reconstructions in SEC, while the intensity of variation is intermittently different. Hydroclimatic variation in the study area might be a comprehensive effect of Pacific Decadal Oscillation (PDO), Western Pacific Subtropical High (WPSH) and El Nino-Southern Oscillation (ENSO) variations. Our reconstruction provides additional support not only for a comprehensive understanding of the spatiotemporal characteristics of hydroclimatic variations, but also for the diagnosis and prediction of hydroclimatic anomalies.

The bioavailable trace metals are closely related to environmental safety and human health, which might have different source characteristics from the total trace metals in soil. To identify such differences, 31 farmland soil samples were collected from a typical agricultural watershed in East China and analyzed for bioavailable trace metal sources by using chemical fractionation, linear regression, and receptor model. Results showed that the total concentrations of Pb, Cu, Zn, Cr, and Ni in the soils were 1.25-1.59 times higher than watershed background values, but they were all dominated by the residual fraction (63.39-86.36%) according to a modified Community Bureau of Reference (BCR) sequential extraction procedure. Both chemical fractionation and enrichment factors (EFs) indicated a major contribution of the natural source to the total trace metal concentrations in the soils. However, linear regressions revealed that 60.07-89.88% of the bioavailable Pb, Cu, Zn, and Ni concentrations were contributed by anthropogenic sources. Atmospheric deposition and livestock manure were identified as the two major anthropogenic sources, and their contributions were further estimated by using a multiple linear regression of absolute principal component scores (MLR-APCS) model. Together with natural contribution, atmospheric deposition could contribute 74.55-89.86% of bioavailable Pb, Cr, and Ni concentrations. Livestock manure contributed 85.54% of bioavailable Cu and 80.05% of bioavailable Zn concentrations, respectively. These results implied that the bioavailable trace metals were influenced by both anthropogenic and natural sources, but more influenced by anthropogenic sources for bioavailable Pb, Cu, Zn, and Ni in the soils. Special attention should be paid to bioavailable Pb when implementing effective pollution control strategies in this watershed. Moreover, the risk caused by bioavailable trace metal losses from soils to aquatic system should not be ignored.

BACKGROUND Neurofibromatosis type 1 (NF1) is an inherited autosomal dominant disorder affecting many parts of the body with cafe au lait spots, skeletal deformity, and scoliosis. A familial case of NF1 with scoliosis and a painless mass had not yet been reported. CASE SUMMARY We describe the case of a 15-year-old male patient with a painless lump on the left side of his neck for 10 years and scoliosis. His right shoulder was about 5 cm lower than the left, the left side of his face was deformed, and the left submandibular skin was relaxed. The folding and drooping were obvious and movement was poor. Computed tomography revealed the involvement of the neck, upper chest wall, and surrounding left shoulder, accompanied by bone changes and scoliosis. Histological evaluation showed subepidermal pale blue mucoid degeneration, fibrous fusiform cells in the dermis in a fascicular, woven arrangement. His mother had the same medical history. The diagnosis was neurofibromatosis of the left neck. Various parts of the tumor tissue were serially resected during several visits. Eight months after surgery, there was a slight tendency to regrow. CONCLUSION This case of slow-progressing NF1 highlights the importance of early diagnosis and treatment to reduce its impact on the patient's growth and development.

Background Cognitive dysfunction is increasingly recognized as an important complication of diabetes mellitus (DM). Accumulating evidence indicates that the abnormality of cerebrovascular structure and function plays an essential role in diabetic cognitive impairment (DCI), however, changes in cerebrovascular factors have been blurred during the development of diabetes. Objective To evaluate the changes in the structure and function of cerebrovascular in DCI mice and to investigate the changes of cerebral angiogenesis and stability factors during the development of DM. Methods Diabetes was induced by feeding with high-fat diet combined with intraperitoneal injection of streptozotocin (STZ,120 mg/kg). Cognitive function was evaluated at different stages of DM, cerebral neovascularization, blood-brain barrier (BBB) permeability and hippocampal neurons were measured of DCI mice, and the expression of vascular endothelial growth factor (VEGF) and platelet-derived growth factor receptor β (PDGFRβ) in hippocampus was detected during the development of DM. Results With the progress of diabetes, the learning and memory ability of mice gradually decreased, and DCI mice showed neuronal degeneration, increased BBB permeability and pathological cerebral neovascularization. Moreover, the expression of VEGF in the hippocampus increased first and then decreased at DM+8week, PDGFRβ decreased continuously with the development of diabetes. Conclusions Our results demonstrate that DCI may be attributed to the dynamic expression of VEGF/PDGFRβ in diabetic hippocampus, and pathological cerebral neovascularization, increased BBB permeability and neuronal degeneration are the key links.

Widespread drug resistance has become the key issue in global healthcare. Extensive efforts have been made to reveal not only diverse diseases experiencing drug resistance, but also the six distinct types of molecular mechanisms underlying this resistance. A database that describes a comprehensive list of diseases with drug resistance (not just cancers/infections) and all types of resistance mechanisms is now urgently needed. However, no such database has been available to date. In this study, a comprehensive database describing drug resistance information named ‘DRESIS’ was therefore developed. It was introduced to (i) systematically provide, for the first time, all existing types of molecular mechanisms underlying drug resistance, (ii) extensively cover the widest range of diseases among all existing databases and (iii) explicitly describe the clinically/experimentally verified resistance data for the largest number of drugs. Since drug resistance has become an ever-increasing clinical issue, DRESIS is expected to have great implications for future new drug discovery and clinical treatment optimization. It is now publicly accessible without any login requirement at: https://idrblab.org/dresis/

Why one chemical is more stable than another is not always easy to understand. A unified answer for metal clusters has led to the establishment of the superatom concept, which rationalizes the delocalization of electrons; however, cluster stability based on superatom theory has not been confirmed unambiguously for any metal other than the s- and p-blocks of the periodic table of elements. Here, we have prepared pure niobium clusters and observed their reactions with CO under sufficient gas collision conditions. We find prominent inertness of Nb12+, which survives CO attack. Comprehensive theoretical calculation results reveal that the inertness of Nb12+ is associated with its cage structure and well-organized superatomic orbitals, giving rise to energetic superiority among the studied clusters. It is revealed that not only the 5s but also the 4d electrons of Nb delocalize in the cluster and significantly contribute to the superatomic state, resulting in reasonable cage aromaticity. This hollow-cage cluster, which we have called a ‘niobespherene’, provides a clue with regard to designing new materials of all-metal aromaticity and Nb-involved catalysts free of CO poisoning.

Alexithymia is a psychiatric symptom characterized by difficulties in emotion recognition, expression, and regulation. The purpose of our study was to investigate the prevalence of alexithymia among patients with epilepsy (PWE) and related factors.By the means of a cross-sectional study, we consecutively recruited PWE who visited the First Hospital of Jilin University. The demographical information and clinical data were collected. Toronto Alexithymia Scale-20 (TAS-20), Emotion Regulation Questionnaire (ERQ), Kilifi Stigma Scale for Epilepsy (KSSE), Neurological Disorders Depression Inventory for Epilepsy (NDDI-E), Generalized Anxiety Disorder-7 (GAD-7), and Nurses' Global Assessment of Suicide Risk scale (NGASR) scales were applied to assess alexithymia, emotion regulation strategies, and the presence of comorbid psychiatric symptoms.A total of 203 PWE were included. The differences in education, monthly per capita income of the family, and the number of antiepileptic drugs were statistically significant among these three groups with alexithymia, possible alexithymia, and non-alexithymia (p 0.05). Toronto Alexithymia Scale-20 scores were significantly and positively correlated with BMI (rho = 0.143, p = 0.042). Expression suppression, stigma, and generalized anxiety were independent risk factors for alexithymia (RA high prevalence of alexithymia (18.7%) was found in PWE. Alexithymia is primarily influenced by the emotional regulation strategies, anxiety, and stigma among PWE. It tends to be a mood symptom or personality trait rather than a direct result of epilepsy.

A broadband silicon four-mode (de)multiplexer [(De)MUX] is proposed and experimentally demonstrated based on subwavelength gratings (SWGs)-assisted triple-waveguide couplers (TWCs), which can (de)multiplex TE0, TE1, TE2, and TE3 modes. The mode interaction is enhanced, benefitting from both the triple-waveguide coupling and subwavelength structures. The proposed four-mode (De)MUX is composed of three SWG-assisted TWCs connected by three linear tapers. The experimental results show that the 3-dB bandwidths are 100 nm, 76 nm, 90 nm, and 95 nm for the TE0, TE1, TE2, and TE3 modes, respectively. The corresponding insertion losses are 0.2, 1.8, 1.3, and 1.7 dB, and the mode crosstalks are -23.3, -17.7, -15.5, and -17.0 dB at the 1550 nm wavelength. The proposed device can work as a mode-(De)MUX compatible with wavelength division multiplexing (WDM) to increase the transmission capacity of on-chip optical interconnects.

Copper-related materials are used for separation of ethylene and acetylene gases in chemistry; however, the precise mechanism regarding selectivity is elusive to be fully understood. Here, we have conducted a joint experimental and theoretical study of the Cun- (n = 7-30) clusters in reacting with C2H4 and C2H2. It is found that all of the Cun- clusters readily react with C2H2, giving rise to C2H2-addition products; however, Cu18- and Cu19- do not react with C2H4. We illustrate the superatomic stability of Cu18- and advocate its availability to separate C2H4 from C2H2. Further, we demonstrate the atomically precise mechanism regarding selectivity by fully unveiling the size-dependent cluster-π interactions.

Background Shocks near defibrillation threshold (nDFT) strength commonly extinguish all ventricular fibrillation (VF) wavefronts, but a train of rapid, well-organized postshock activations (PAs) typically appears before sinus rhythm ensues. If one of the PA waves undergoes partial propagation block (wavebreak), reentry may be induced, causing VF to reinitiate and the shock to fail. Objective The purpose of this study was to determine whether wavebreak leading to VF reinititation following nDFT shocks occurs preferentially at the right ventricular insertion (RVI), which previous studies have identified as a key site for wavebreak. Methods We used panoramic optical mapping to image the ventricular epicardium of 6 isolated swine hearts during nDFT defibrillation episodes. After each experiment, the hearts were fixed and their geometry scanned with magnetic resonance imaging (MRI). The MRI and mapping datasets were spatially coregistered. For failed shocks, we identified the site of the first wavebreak of a PA wave during VF reinitiation. Results We recorded 59 nDFT failures. In 31 of these, the first wavebreak event occurred within 1 cm of the RVI centerline, most commonly on the anterior side of the right ventricular insertion (aRVI) (23/31). The aRVI region occupies 16.8% ± 2.5% of the epicardial surface and would be expected to account for only 10 wavebreaks if they were uniformly distributed. By χ2 analysis, aRVI wavebreaks were significantly overrepresented. Conclusion The anterior RVI is a key site in promoting nDFT failure. Targeting this site to prevent wavebreak could convert defibrillation failure to success and improve defibrillation efficacy.

Field ageing gradients of bitumen samples recovered from 14 asphalt road sections were investigated via rheological and chemical characterizations and statistical analysis. The effects of air voids and environmental factors on the ageing gradient were evaluated using the field ageing and climate data. The effectiveness of the pressure ageing vessel (PAV) test was assessed in accelerating the bitumen’s long-term ageing by comparing with the field ageing data. Critical factors for field ageing were identified using statistical methods. A statistical model for the Glover-Rowe (G-R) parameter was formulated and verified by incorporating the screened key factors. Results indicate that a threshold air void content (around 6%) exists in differentiating the field ageing gradient patterns in the asphalt pavements. An increasing tendency is observed between the ageing gradient and annual days below 0°C. The chemical indices, stiffness-related indices, and G-R parameter can quantify the field ageing gradient of asphalt pavements. The PAV test can condition the bottom slices’ bitumen to the same ageing level as that in a pavement depth of 0.5–2 cm after 8 years’ field service. Pavement service life, binder content, minimum temperature, days above 32°C, and days below 0°C are the critical material and environmental factors that significantly affect bitumen’s complex shear modulus, crossover frequency, G-R parameter, and Δ Tc. The statistical model is verified with an acceptable mean absolute error of 28.1% and a R2 value of 0.95.

Utilizing a customized metal cluster source in tandem with a flow tube reactor and a reflectron time-of-flight mass spectrometer, we have obtained well-resolved pure metal clusters Ptn- and observed their gas-phase reactions with a few small gas molecules. Interestingly, the remarkable inertness of Pt10- was repeatedly observed in different reactions. Meanwhile, we have determined the structure of Pt10- within a regular tetrahedron. Considering that Pt possesses 5d96s1 electron configuration, the tetrahedral Pt10- exhibits unexpected stability at neither a magic number of valence electrons nor a shell closure of geometric structure. Comprehensive theoretical calculations unveil the stability of Pt10- is significantly associated with the all-metal aromaticity. In addition to the classical total aromaticity, which is mainly due to 6s electrons, there is unique beta-aromaticity ascribed to spin-polarized beta 5d electrons pertaining to singly occupied multicenter bonds. Further, we demonstrate the superatomic feature of such a transition metal cluster Pt10-, as Pt6@Pt4-, in mimicking methane.

Local pollution and the cross-boundary transmission of pollutants between cities have an inevitable impact on the atmosphere. Quantitative assessments of the contribution of transport to pollution in inland and coastal cities are necessary for the implementation of practical, regional, and joint emission control strategies. In this study, the Comprehensive Air Quality Model (CAMx), together with the Weather Research and Forecasting model (WRF), was used to simulate the contributions to pollution of different cities in 2016. The monthly inflow, outflow, and net flux from the ground to the extended layers served as the three main indicators for the analysis of the interactions of PM2.5 transport between adjacent cities. Between inland and coastal cities, the magnitude of inflow and outflow are larger in the former than in the latter. The inflow flux in the inland cities (Beijing and Shijiazhuang) was 10.6 and 10.7 kt/day, respectively, while that in the coastal cities (Tianjin, Shanghai, Hefei, Nanjing, and Hangzhou) was 9.1, 3.3, 5.8, 4.4, and 3.7 kt/day, respectively. In terms of variation over the year, the strongest inflow in the BTH region occurred in April, followed by October, July, and January, while that in the coastal cities in YRD occurred in January, followed by October, April, and July. Therefore, based on the flux intensity calculations and the transport flux pathways, effective joint control measures can be provided with scientific support, and a better understanding of the evolutionary mechanism among inland and coastal cities can be acquired.

Due to challenges in preparing pure metal clusters and in controlling reactions, the oxides produced by metal clusters reacting with oxygen are often different from traditional ion-molecule products in the gas phase and their reactivity pattern is also largely unveiled yet. In this work, utilizing a customized Re-TOFMS having a home-made cluster source and a flow tube reactor, we have observed the gaseous reactions of Nin± clusters with oxygen and found magic clusters of Ni13O8± that dominate the mass distributions. By quantum chemistry calculations, we find that both Ni13O8− and Ni13O8+ clusters bear a regular cubic structure with 8 oxygen anchoring the eight angles, however, they have rather different spin accommodations. The Ni13O8− clusters have 15 unpaired spin-up electrons exhibiting cubic aromaticity and decent ferromagnetism, while the Ni13O8+ clusters take a lower-spin ground state (11 unpaired electrons), with spin-down population on the central Ni atom pertaining to ferrimagnetism. This is a class of metalloxocube clusters that hold properties of aromaticity and ferromagnetism/ferrimagnetism charcterized by a few spin electrons, which embodies the bonding nature of superatomic compounds and enables to develop cluster-genetic materials of multi-functionality.

A broadband mode (de)multiplexer [(De)MUX] is proposed and experimentally demonstrated based on a triple-waveguide coupler (TWC) with the phase-matching of a multimode access-waveguide. The tolerance to the operating wavelength and fabrication error of the proposed mode (De)MUX can be relaxed with the aid of the wider access-waveguide and the middle waveguide. The optimized mode (De)MUX is with a coupling length of $48~\mu $ m and a broad bandwidth of >122 nm with the mode crosstalk of

We report a joint experimental and theoretical study on the reactions of cobalt clusters (Con±/0) with nitrogen using the customized reflection time-of-flight mass spectrometer combined with a 177....

Two-dimensional (2D) MXenes based on early transition-metal carbides and nitrides have highly tunable electrochemical properties including excellent catalytic activity for the hydrogen evolution re...

Semi-analytical finite element method has great advantages in computational efficiency compared with three-dimensional, because it only requires a two-dimensional mesh in the cross-section by incor...

Tropical coral reef lagoons that are characterized by high deposition rates are potentially useful for high-resolution palaeoenvironmental reconstructions. We present the geochemical and accelerator mass spectrometry (AMS) C-14-dating data of a 113-cm gravity core obtained from the Yongle atoll lagoon in the South China Sea. The core record preserves a continuous 1,500-year depositional history of the back-reef lagoon environment, with sedimentation rates varying from 0.55 to 1.55 mm yr(-1) (mean of 0.74 mm yr(-1)). Calcium carbonate (CaCO3) production was calculated based on the sediment accumulation rates and sediment density to be 807 g m(-2) yr(-1). The geochemical records of the studied core displayed a progressively increasing trend of storms over the past 1,500 years. The stable carbon and oxygen isotopes of the lagoon sediment have the potential to record monsoon intensity. The lagoon system of the Yongle atoll appears to have been influenced by minor terrestrial input from 1,500 calendar years before present (cal yr BP) to 500 cal yr BP, and by a strong anthropogenic influence over the past 200 years.

Hydrogen evolution reaction (HER) is known as the heart of various energy storage and conversation systems of renewable energy sources. Here we observe the cluster reactions of a light transition metal, vanadium, with water in a gas-phase flow tube reactor. While HER products of V1 and V2 were not observed, the effective HER of water on neutral Vn (n ≥ 3) clusters reveals reasonable and size-dependent reactivity of the vanadium clusters. Superatomic features and reaction dynamics of V10, V13, and V16 are highlighted. Among the three typical superatoms, V10 and V16 exhibit an abnormal superatomic orbital energy level order, 1S|2S|1P|1D..., where the energy-reduced 2S orbital helps to accommodate the geometric structure and hence reinforce the cluster stability. In comparison, V13 bears a less symmetrical structure and reacts readily with water, allowing for recombination of a hydroxyl atom with an adsorbed hydrogen atom, akin to a fishing-mode HER process. The joint experimental and theoretical study on neutral Vn clusters clarifies the availability of superatom chemistry for transition metals and appeals further development of cluster theory based on electronic cloud/orbital analysis instead of simply counting the valence electrons. Also, we provide insights into the HER mechanism of metal clusters and propose a strategy to design new materials for portable fuel cells of hydrogen energy.

Analyzing dynamic viscoelastic responses induced by moving loads is a significant issue for pavement design and performance evaluation. Developing three-dimensional FE models in commercial software...