The IEEE 802.11ax for Wireless Local Area Network (WLAN), one of the most important wireless networks, will be released in 2020. In recent years, ultra-high definition video service and real-time ...applications attract increasing attention. Therefore, the next generation WLAN (beyond IEEE 802.11ax): IEEE 802.11be task group (TGbe) was formally established in 2019, which regards achieving extremely high throughput (EHT) as its core technical objective. This article investigates and analyzes the key technologies of IEEE 802.11be, and further provides our perspectives and insights on it. Specifically, this article gives a brief overview on IEEE 802.11be, including the target scenario and technical objective, key technologies overview, and the standardization process. After that, we further investigate, analyze and provide perspectives on the key technologies of IEEE 802.11be including multi-band operation, multi-AP coordination, enhanced link reliability, and latency & jitter guarantee. To the best of our knowledge, this is the first work to investigate, analyze and provide insights on IEEE 802.11be.
Reactive oxygen species (ROS), a redox signal, are produced by various enzymatic reactions and chemical processes, which are essential for many physiological functions and act as second messengers. ...However, accumulating evidence has implicated the pathogenesis of several human diseases including neurodegenerative disorders related to increased oxidative stress. Under pathological conditions, increasing ROS production can regulate the expression of diverse inflammatory mediators during brain injury. Elevated levels of several proinflammatory factors including cytokines, peptides, pathogenic structures, and peroxidants in the central nervous system (CNS) have been detected in patients with neurodegenerative diseases such as Alzheimer’s disease (AD). These proinflammatory factors act as potent stimuli in brain inflammation through upregulation of diverse inflammatory genes, including matrix metalloproteinases (MMPs), cytosolic phospholipase A2 (cPLA2), cyclooxygenase-2 (COX-2), and adhesion molecules. To date, the intracellular signaling mechanisms underlying the expression of target proteins regulated by these factors are elusive. In this review, we discuss the mechanisms underlying the intracellular signaling pathways, especially ROS, involved in the expression of several inflammatory proteins induced by proinflammatory factors in brain resident cells. Understanding redox signaling transduction mechanisms involved in the expression of target proteins and genes may provide useful therapeutic strategies for brain injury, inflammation, and neurodegenerative diseases.
Reactive oxygen species (ROS) are products of normal cellular metabolism and are known to act as second messengers. Under physiological conditions, ROS participate in maintenance of cellular ‘redox ...homeostasis’ in order to protect cells against oxidative stress. In addition, regulation of redox state is important for cell activation, viability, proliferation, and organ function. However, overproduction of ROS, most frequently due to excessive stimulation of either reduced nicotinamide adenine dinucleotide phosphate (NADPH) by pro-inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) or the mitochondrial electron transport chain and xanthine oxidase, results in oxidative stress. Oxidative stress is a deleterious process that leads to airway and lung damage and consequently to several respiratory inflammatory diseases/injuries, including acute respiratory distress syndrome (ARDS), asthma, cystic fibrosis (CF), and chronic obstructive pulmonary disease (COPD). Many of the known inflammatory target proteins, such as matrix metalloproteinase-9 (MMP-9), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), cyclooxygenase-2 (COX-2), and cytosolic phospholipase A2 (cPLA2), are associated with NADPH oxidase activation and ROS overproduction in response to pro-inflammatory mediators. Thus, oxidative stress regulates both key inflammatory signal transduction pathways and target proteins involved in airway and lung inflammation. In this review, we discuss mechanisms of NADPH oxidase/ROS in the expression of inflammatory target proteins involved in airway and lung diseases. Knowledge of the mechanisms of ROS regulation could lead to the pharmacological manipulation of antioxidants in airway and lung inflammation and injury.
The generation of terminally differentiated cell lineages during organogenesis requires multiple, coordinated cell fate choice steps. However, this process has not been clearly delineated, especially ...in complex solid organs such as the pancreas. Here, we performed single‐cell RNA‐sequencing in pancreatic cells sorted from multiple genetically modified reporter mouse strains at embryonic stages E9.5–E17.5. We deciphered the developmental trajectories and regulatory strategies of the exocrine and endocrine pancreatic lineages as well as intermediate progenitor populations along the developmental pathways. Notably, we discovered previously undefined programs representing the earliest events in islet α‐ and β‐cell lineage allocation as well as the developmental pathway of the “first wave” of α‐cell generation. Furthermore, we demonstrated that repressing ERK pathway activity is essential for inducing both α‐ and β‐lineage differentiation. This study provides key insights into the regulatory mechanisms underlying cell fate choice and stepwise cell fate commitment and can be used as a resource to guide the induction of functional islet lineage cells from stem cells in vitro.
Synopsis
Combining genetic lineage tracing and single‐cell gene expression analyses, this resource deciphers the multistep trajectories of endocrine and exocrine lineages and intermediate progenitor populations during early murine pancreas development.
Single‐cell analysis of cell lineages from fetal pancreas at E9.5–E17.5 identifies differentiation steps and pathways from multipotent progenitors to endocrine and exocrine lineages.
Fifteen cell clusters delineate all pancreatic cell types and four steps of cell fate decisions from progenitors to islet lineages.
Developmental pathways involved in the “first wave” of alpha‐cell generation differ from intermediate progenitor and population specific markers.
Endocrine progenitors undergo four transient stages.
The MAPK/ERK pathway restrains early endocrine specification.
An integrated analysis defines specification of pancreatic cell types from multipotent progenitors to endocrine and exocrine lineages and branching points during early mouse development.
The NF-κB (nuclear factor κ-light-chain-enhancer of activated B cells) transcription factor family is a pleiotropic regulator of many cellular signaling pathways, providing a mechanism for the cells ...in response to a wide variety of stimuli linking to inflammation. The stimulated cells will be regulated by not only the canonical but also non-canonical NF-κB pathways. To initiate both of these pathways, IκB-degradation triggers NF-κB release and the nuclear translocated-heterodimer (or homodimer) can associate with the κB sites of promoter to regulate the gene transcriptions. NF-κB ubiquitously expresses in neurons and the constitutive NF-κB activation is associated with processing of neuronal information. NF-κB can regulate the transcription of genes such as chemokines, cytokines, proinflammatory enzymes, adhesion molecules, proinflammatory transcription factors, and other factors to modulate the neuronal survival. In neuronal insult, NF-κB constitutively active in neuron cell bodies can protect neurons against different injuries and regulate the neuronal inflammatory reactions. Besides neurons, NF-κB transcription factors are abundant in glial cells and cerebral blood vessels and the diverse functions of NF-κB also regulate the inflammatory reaction around the neuronal environment. NF-κB transcription factors are abundant in the brain and exhibit diverse functions. Several central nerve system (CNS) diseases are linked to NF-κB activated by inflammatory mediators. The RelA and c-Rel expression produce opposite effects on neuronal survival. Importantly, c-Rel expression in CNS plays a critical role in anti-apoptosis and reduces the age-related behaviors. Moreover, the different subunits of NF-κB dimer formation can modulate the neuroninflammation, neuronal protection, or neurotoxicity. The diverse functions of NF-κB depend on the subunits of the NF-κB dimer-formation which enable us to develop a therapeutic approach to neuroinflammation based on a new concept of inflammation as a strategic tool in neuronal cells. However, the detail role of NF-κB in neuroinflammation, remains to be clarified. In the present article, we provide an updated review of the current state of our knowledge about relationship between NF-κB and neuroinflammation.
•Tunnel excavation-induced karst groundwater drawdown changed hydrological processes.•Tunnel excavation changed the distribution patterns of karst water resources.•Tunnel excavation altered the ...physical and chemical properties of karst soils.•Tunnel excavation changed physiological processes and growth rates of karst plants.•Tunnel excavation induced karst geological hazards.
Due to a lack of awareness of environmental protection at the beginning of tunnel excavation and the unique ecological vulnerability of karst areas, tunnel excavation is beginning to have increasingly serious negative effects on the ecological environments in karst areas, leading to challenges related to regional water resources and ecological security. The groundwater drawdown caused by tunnel drainage has had far-reaching impacts on the hydrology, ecology and environment in karst areas. The most prominent effects of the recent advances in drainage techniques include the destruction of aquifer structures, changes in the distribution patterns of water resources and the groundwater flow field and even the initiation of geological disasters (i.e., collapses) in karst areas. In addition, karst water circulation and hydrogeochemical processes have also been affected. However, due to the complex geological conditions and limited observational data in karst areas, the impacts of tunnel drainage on ecological systems remain poorly understood. With increased understanding, researchers have found that the physical and chemical properties of the soil, the speed of soil erosion, the physiological processes and growth rates of plants, and even the compositions of plant communities are gradually changing in tunnel-affected karst areas, although the understanding of these processes and mechanisms remains far from sufficient. Based on the progress made regarding the understanding of water resource and hydrological process issues resulting from tunnel excavation in karst areas, we expect to experience a worldwide increase in investigations of the eco-hydrogeological effects of tunnel excavation in the future.
Ultra-short-term photovoltaic power prediction is one of the important measures to reduce the adverse effects of the safe and stable operation of traditional power systems. First, the periodicity of ...the PV power is taken into account to extract periodic components. For the remaining components, under different weather types, the local sensitive hashing algorithm algorithm is used to achieve rapid classification of photovoltaic power segments, and the European distance is introduced as a measure of the prediction to predict. Using the data of the photovoltaic power station for verification, the results show that the method has a higher prediction accuracy.
A hydroxyapatite-biochar nanocomposite (HAP-BC) was successfully fabricated and its physicochemical properties characterized. The analyses showed that HAP nanoparticles were successfully loaded on ...the biochar surface. The adsorption of Pb(II), Cu(II), and Zn(II) by HAP-BC was systematically studied in single and ternary metal systems. The results demonstrated that pH affects the adsorption of heavy metals onto HAP-BC. Regarding the adsorption kinetics, the pseudo-second-order model showed the best fit for all three heavy metal ions on HAP-BC. In both single and ternary metal ion systems, the adsorption isotherm of Pb(II) by HAP-BC followed Langmuir model, while those of Cu(II) and Zn(II) fitted well with Freundlich model. The maximum adsorption capacity for each tested metal by HAP-BC was higher than that of pristine rice straw biochar (especially for Pb(II)) or those of other reported adsorbents. Therefore, HAP-BC could explore as a new material for future application in heavy metal removal.
A novel hydroxyapatite-biochar nanocomposite was synthesized and used for Pb(II), Cu(II), and Zn(II) removal in solutions. Display omitted
•A novel hydroxyapatite-biochar nanocomposite (HAP-BC) was synthesized.•The HAP-BC was tested for the adsorption of Pb(II), Cu(II), and Zn(II).•The HAP-BC showed enhanced sorption of Pb(II), Cu(II), and Zn(II).•The adsorbed HAP-BC can be effectively regenerated by using HCl solution.•The HAP-BC can be used to remove heavy metals from wastewater.
For the Bluetooth Low Energy (BLE) connection events, a 2-dimensional Markov chain-based model is proposed in this letter, to compute and analyze the duration, duty cycle, power consumption and the ...maximum throughput. A general application of peer-to-peer bidirectional data transmission is described in this model, by taking the influence of data transmission states of both the central and peripheral devices on connection event state into account. The impacts of connection parameters, closing rules of connection events and channel quality on the performance are also analyzed. Experimental results show that the proposed model can accurately calculate the terms of average connection event duration, average energy consumption and the maximum throughput of both the central and peripheral devices.
This study explores the smoothing effect on the uncertainty of the wind power fluctuations that affect a power system at points of common coupling. Set pair analysis is applied to evaluate the ...similarity between the power fluctuations of a single wind turbine and those of all aggregated wind turbines, based on which a quantitative index describing the wind power smoothing effect is proposed. The smoothing effect characteristics of a wind farm cluster are investigated for different numbers of wind turbines, different wind speeds, different seasons, and multiple sampling intervals. A significant smoothing effect is usually observed at a shorter sampling interval and a higher wind speed, and the smoothing effect index increases with an increase in the numbers of wind turbines and farms. Additionally, the correlation between the smoothing effect of aggregated wind farms and the forecast accuracy for the corresponding aggregated power output is examined. The experimental results indicate that the wind power forecast accuracy varies with the smoothing effect index, which is influenced by the number of wind farms. Furthermore, the aggregated output from a wind farm cluster with a higher smoothing effect index exhibits better forecasting performance than that from a single wind farm, showing that the trend of the wind power series becomes smoother due to the smoothing effect, thus enabling one-step-ahead wind power forecasting with higher accuracy.
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