Since December 2019, novel coronavirus infected pneumonia emerged in Wuhan city and rapidly spread throughout China. In severe novel coronavirus pneumonia cases, the number of platelets, their ...dynamic changes during the treatment, platelet‐to‐lymphocyte ratio (PLR) were a concern. We sought to describe the platelet feature of these cases. Single‐center case series of the 30 hospitalized patients with confirmed coronavirus disease (COVID)‐19 in Huizhou municipal central hospital from January 2020 to February 2020 were retrospectively analyzed. Demographic, clinical, blood routine results, other laboratory results, and treatment data were collected and analyzed. Outcomes of severe patients and nonsevere patients were compared. Univariate analysis showed that: age, platelet peaks, and PLR at peak platelet were the influencing factors in severe patients, multivariate analysis showed that the PLR value at peak platelet during treatment was an independent influencing factor in severe patients. The average hospitalization day of patients with platelet peaks during treatment was longer than those without platelet peaks (P < .05). The average age of patients with platelet peaks during treatment was older than those without platelet peaks (P < .05). The patients with significantly elevated platelets during treatment had longer average hospitalization days. And the higher PLR of patients during treatment had longer average hospitalization days. Single‐center case series of the 30 hospitalized patients with confirmed COVID‐19 in Huizhou Municipal Central Hospital, presumed that the number of platelets and their dynamic changes during the treatment may have a suggestion on the severity and prognosis of the disease. The patient with markedly elevated platelets and longer average hospitalization days may be related to the cytokine storm. The PLR of patients means the degree of cytokine storm, which might provide a new indicator in the monitoring in patients with COVID‐19.
Power systems are being exposed to cyber-attacks due to the high integration of information technology and the vulnerability of communication networks. Existing false data attacks research focus on ...dc state estimation. In this paper, we show that an attacker can construct an undetectable attack vector against ac state estimation based on a few measurements in the attacking region associated with boundary buses without knowing the full topology and parameter information of the entire power network. An iteration approach is adopted to obtain the attack vector. The simulations on the IEEE 14-bus and 118-bus systems are used to demonstrate the correctness and effectiveness of the proposed attack scheme. This paper provides a basis to study the attack behaviors under the ac case, and a theoretical guide to develop protection strategies and detection methods.
Mechanisms of soil organic carbon (SOC) stabilization have been widely studied due to their relevance in the global carbon cycle. No‐till (NT) has been frequently adopted to sequester SOC; however, ...limited information is available regarding whether sequestered SOC will be stabilized for long term. Thus, we reviewed the mechanisms affecting SOC stability in NT systems, including the priming effects (PE), molecular structure of SOC, aggregate protection, association with soil minerals, microbial properties, and environmental effects. Although a more steady‐state molecular structure of SOC is observed in NT compared with conventional tillage (CT), SOC stability may depend more on physical and chemical protection. On average, NT improves macro‐aggregation by 32.7%, and lowers SOC mineralization in macro‐aggregates compared with CT. Chemical protection is also important due to the direct adsorption of organic molecules and the enhancement of aggregation by soil minerals. Higher microbial activity in NT could also produce binding agents to promote aggregation and the formation of metal‐oxidant organic complexes. Thus, microbial residues could be stabilized in soils over the long term through their attachment to mineral surfaces and entrapment of aggregates under NT. On average, NT reduces SOC mineralization by 18.8% and PE intensities after fresh carbon inputs by 21.0% compared with CT (p < .05). Although higher temperature sensitivity (Q10) is observed in NT due to greater Q10 in macro‐aggregates, an increase of soil moisture regime in NT could potentially constrain the improvement of Q10. This review improves process‐based understanding of the physical and chemical mechanism of protection that can act, independently or interactively, to enhance SOC preservation. It is concluded that SOC sequestered in NT systems is likely to be stabilized over the long term.
Understanding the mechanisms of soil organic carbon (SOC) stability could be better to predict the SOC fate under climate change. Our review identified the factors affecting SOC stability and the roles of microbial residues in SOC stability regulated by physicochemical protection. This study provides systematic evidences of enhanced SOC accumulation under no‐till at upper soil depth, and improves process‐based understanding of the physical and chemical mechanisms of protection that can act, independently or interactively, to enhance SOC preservation. It is concluded that SOC sequestered in no‐till systems could be stabilized over the long term.
Adsorptive separation of propylene/propane (C3H6/C3H8) mixture is desired for its potential energy saving on replacing currently deployed and energy‐intensive cryogenic distillation. Realizing ...efficient C3H6/C3H8 separation in the emerging hydrogen‐bonded organic frameworks (HOFs) is very challenging owing to the lack of functional sites for preferential gas binding. By virtue of crystal engineering, we herein report a functionalized HOF (HOF‐16) with free ‐COOH sites for the efficient separation of C3H6/C3H8 mixtures. Under ambient conditions, HOF‐16 shows a significant C3H6/C3H8 uptake difference (by 76 %) and selectivity (5.4) in contrast to other carboxylic acid‐based HOFs. Modeling studies indicate that free ‐COOH groups together with the suitable pore confinement facilitate the recognition and high‐density packing of gas molecules. The separation performance of HOF‐16 was validated by breakthrough experiments. HOF‐16 is stable towards strong acidity and water.
A robust hydrogen‐bonded organic framework with free COOH groups and suitable pore confinement demonstrates excellent performance for the important and challenging C3H6/C3H8 separation.
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•The influence of spatio-temporal factors on human comfort was quantified.•Seasonal change is the main factor affecting physical ...comfort.•Theartificialimpermeablematrixincreasesthesurfacethermalfieldtemperature.•Natural factors can always effectively reduce the surface temperature.•Human comfort can be improved to a certain extent through human intervention.
In recent decades, urbanization and the dramatic increase in urban populations have exacerbated the urban heat island effect. At present, much attention has been paid to the causes and patterns of the urban heat island effect. However, there are few quantitative studies on the impact of the urban heat island effect. By extracting post-world climate data, DEM data, and land use data for 20 years between 2001 and 2020, this paper first studies the variation pattern and spatial distribution characteristics of urban heat islands in New York State, summarizes the seasonal distribution characteristics of temperature, and then uses Giles formula to calculate Tom's discomfort index and evaluate human thermal comfort, and evaluates the effect of heat island effect on human sensory thermal comfort. The results show that on the time scale, the surface temperature in the study area generally showed a slow upward trend over the past 20 years. For example, in July, the maximum and minimum temperatures increased by 3.2 °C and 4.1 °C, respectively. At the spatial scale, most of the heat island areas in the study area were distributed in the New York City agglomeration, especially from May to October, when the heat island effect was particularly obvious. The temperature map showed obvious high temperatures. Compared with 2001, the human discomfort index (DI) increased between June and August 2020. The land use map shows that as the city expands, people's DI index also increases, and the proportion of people who feel uncomfortable with heat increases to 50%. Except for the New York City cluster, other areas were mostly athermic-free. This result shows that excessive urban development concentration seriously affects residents' quality of life. We should pay attention to the superimposed impact of climate change and urban heat islands on the human discomfort index, and adjust the local high temperature and thermal field area through reasonable planning, strengthening greening, and using building technology to make cities more livable.
Two‐dimensional (2D) nanomaterials, such as graphene and transition metal chalcogenides, show many interesting dimension‐related materials properties. Inspired by the development of 2D inorganic ...nanomaterials, single‐layered covalent organic frameworks (sCOFs), featuring atom‐thick sheets and crystalline extended organic structures with covalently bonded building blocks, have attracted great attention in recent years. With their unique graphene‐like topological structure and the merit of structural diversity, sCOFs promise to possess novel and designable properties. However, the synthesis of sCOFs with well‐defined structures remains a great challenge. Herein, the recent development of the bottom‐up synthesis methods of 2D sCOFs, such as thermodynamic equilibrium control methods, growth‐kinetics control methods, and surface‐assisted covalent polymerization methods, are reviewed. Finally, some of the critical properties and application prospects of these materials are outlined.
Single‐layered covalent organic frameworks (sCOFs), mimicking the topology of graphene, but incorporating chemical functionality into their backbones, are pursued as potential candidates in nanoelectronics. Several representative synthesis strategies for the synthesis of high‐quality graphene‐like sCOFs with extended order are reviewed and the application prospects of sCOFs are outlined.
High-entropy pyrochlore-type structures based on rare-earth zirconates are successfully produced by conventional solid-state reaction method. Six rare-earth oxides (La
2
O
3
, Nd
2
O
3
, Sm
2
O
3
, ...Eu
2
O
3
, Gd
2
O
3
, and Y
2
O
3
) and ZrO
2
are used as the raw powders. Five out of the six rare-earth oxides with equimolar ratio and ZrO
2
are mixed and sintered at different temperatures for investigating the reaction process. The results demonstrate that the high-entropy pyrochlores (5RE
1/5
)
2
Zr
2
O
7
have been formed after heated at 1000°C. The (5RE
1/5
)
2
Zr
2
O
7
are highly sintering resistant and possess excellent thermal stability. The thermal conductivities of the (5RE
1/5
)
2
Zr
2
O
7
high-entropy ceramics are below 1 W·m
–1
·K
–1
in the temperature range of 300–1200°C. The (5RE
1/5
)
2
Zr
2
O
7
can be potential thermal barrier coating materials.
Dysregulated prefrontal control over amygdala is engaged in the pathogenesis of psychiatric diseases including depression and anxiety disorders. Here we show that, in a rodent anxiety model induced ...by chronic restraint stress (CRS), the dysregulation occurs in basolateral amygdala projection neurons receiving mono-directional inputs from dorsomedial prefrontal cortex (dmPFC→BLA PNs) rather than those reciprocally connected with dmPFC (dmPFC↔BLA PNs). Specifically, CRS shifts the dmPFC-driven excitatory-inhibitory balance towards excitation in the former, but not latter population. Such specificity is preferential to connections made by dmPFC, caused by enhanced presynaptic glutamate release, and highly correlated with the increased anxiety-like behavior in stressed mice. Importantly, low-frequency optogenetic stimulation of dmPFC afferents in BLA normalizes the enhanced prefrontal glutamate release onto dmPFC→BLA PNs and lastingly attenuates CRS-induced increase of anxiety-like behavior. Our findings thus reveal a target cell-based dysregulation of mPFC-to-amygdala transmission for stress-induced anxiety.
Power grid is one of the most critical infrastructures in a nation and could suffer a variety of cyber attacks. Recent studies have shown that an attacker can inject pre-determined false data into ...smart meters such that it can pass the residue test of conventional state estimator. However, the calculation of the false data vector relies on the network (topology and parameter) information of the entire grid. In practice, it is impossible for an attacker to obtain all network information of a power grid. Unfortunately, this does not make power systems immune to false data injection attacks. In this paper, we propose a local load redistribution attacking model based on incomplete network information and show that an attacker only needs to obtain the network information of the local attacking region to inject false data into smart meters in the local region without being detected by the state estimator. Simulations on the modified IEEE 14-bus system demonstrate the correctness and effectiveness of the proposed model. The results of this paper reveal the mechanism of local false data injection attacks and highlight the importance and complexity of defending power systems against false data injection attacks.
Numerical results for ground-state and excited-state properties (energies, double occupancies, and Matsubara-axis self-energies) of the single-orbital Hubbard model on a two-dimensional square ...lattice are presented, in order to provide an assessment of our ability to compute accurate results in the thermodynamic limit. Many methods are employed, including auxiliary-field quantum Monte Carlo, bare and bold-line diagrammatic Monte Carlo, method of dual fermions, density matrix embedding theory, density matrix renormalization group, dynamical cluster approximation, diffusion Monte Carlo within a fixed-node approximation, unrestricted coupled cluster theory, and multireference projected Hartree-Fock methods. Comparison of results obtained by different methods allows for the identification of uncertainties and systematic errors. The importance of extrapolation to converged thermodynamic-limit values is emphasized. Cases where agreement between different methods is obtained establish benchmark results that may be useful in the validation of new approaches and the improvement of existing methods.
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