Enzyme immobilization in metal–organic frameworks (MOFs) as a promising strategy is attracting the interest of scientists from different disciplines with the expansion of MOFs’ development. Different ...from other traditional host materials, their unique strengths of high surface areas, large yet adjustable pore sizes, functionalizable pore walls, and diverse architectures make MOFs an ideal platform to investigate hosted enzymes, which is critical to the industrial and commercial process. In addition to the protective function of MOFs, the extensive roles of MOFs in the enzyme immobilization are being well-explored by making full use of their remarkable properties like well-defined structure, high porosity, and tunable functionality. Such development shifts the focus from the exploration of immobilization strategies toward functionalization. Meanwhile, this would undoubtedly contribute to a better understanding of enzymes in regards to the structural transformation after being hosted in a confinement environment, particularly to the orientation and conformation change as well as the interplay between enzyme and matrix MOFs. In this Outlook, we target a comprehensive review of the role diversities of the host matrix MOF based on the current enzyme immobilization research, along with proposing an outlook toward the future development of this field, including the representatives of potential techniques and methodologies being capable of studying the hosted enzymes.
The Multipath TCP (MPTCP) protocol has been standardized by the IETF as an extension of conventional TCP, which enables multi-homed devices to establish multiple paths for simultaneous data ...transmission. Congestion control is a fundamental mechanism for the design and implementation of MPTCP. Due to the diverse QoS characteristics of heterogeneous links, existing multipath congestion control mechanisms suffer from a number of performance problems such as bufferbloat, suboptimal bandwidth usage, etc. In this paper, we propose a learning-based multipath congestion control approach called SmartCC to deal with the diversities of multiple communication path in heterogeneous networks. SmartCC adopts an asynchronous reinforcement learning framework to learn a set of congestion rules, which allows the sender to observe the environment and take actions to adjust the subflows' congestion windows adaptively to fit different network situations. To deal with the problem of infinite states in high-dimensional space, we propose a hierarchical tile coding algorithm for state aggregation and a function estimation approach for Q-learning, which can derive the optimal policy efficiently. Due to the asynchronous design of SmartCC, the processes of model training and execution are decoupled, and the learning process will not introduce extra delay and overhead on the decision making process in MPTCP congestion control. We conduct extensive experiments for performance evaluation, which show that SmartCC improves the aggregate throughput significantly and outperforms the state-of-the-art mechanisms on a variety of performance metrics.
Zinc oxide (ZnO) nanostructures have been studied extensively in the past 20 years due to their novel electronic, photonic, mechanical and electrochemical properties. Recently, more attention has ...been paid to assemble nanoscale building blocks into three-dimensional (3D) complex hierarchical structures, which not only inherit the excellent properties of the single building blocks but also provide potential applications in the bottom-up fabrication of functional devices. This review article focuses on 3D ZnO hierarchical nanostructures, and summarizes major advances in the solution phase synthesis, applications in environment, and electrical/electrochemical devices. We present the principles and growth mechanisms of ZnO nanostructures via different solution methods, with an emphasis on rational control of the morphology and assembly. We then discuss the applications of 3D ZnO hierarchical nanostructures in photocatalysis, field emission, electrochemical sensor, and lithium ion batteries. Throughout the discussion, the relationship between the device performance and the microstructures of 3D ZnO hierarchical nanostructures will be highlighted. This review concludes with a personal perspective on the current challenges and future research.
Particulate emissions from motor vehicles have received increased attention over the past two decades owing to associations observed between ambient particulate matter (PM) levels and health effects. ...This has led to numerous changes in emissions regulations worldwide, including more stringent standards, the broadening of these to include non-road engines, and the adoption of new metrics. These changes have created a demand for new instruments that are capable of real time measurement, enhanced sensitivity, and on-board vehicle operation. In response, researchers and instrument manufacturers have developed an array of new and improved instruments and sampling methods. It is generally recognized that the exhaust aerosol concentration measured depends on both the sampling technique and the instrument used. Hence, many of the new instruments are complementary and offer merits in measuring a variety of particulate emissions attributes. However, selecting the best instrument for each application is not a straightforward task; it requires on one hand a clear measurement objective and, on the other, an understanding of the characteristics of the instrument employed.
This paper reviews how vehicle exhaust particulate emission measurements have evolved over the years. The focus is on current and newly evolving instrumentation, including gravimetric filter measurement, chemical analysis of filters, light extinction, scattering and absorption instruments, and instruments based on the electrical detection of exhaust aerosols. Correlations between the various instruments are examined in the context of steadily more stringent exhaust emissions standards. The review concludes with a discussion of future instrument and sampling requirements for the changing nature of exhaust aerosols from current and future vehicles.
•Vehicle exhaust particulate emissions regulation: not only type approval, but also on-board, in-use compliance and smoke for roadworthiness tests.•Current and newly evolving particulate instrumentation and conditioning techniques.•Correlations of particulate instruments in the context of steadily stringent particulate emissions standards.•Matching of measurement methods with measurement needs.
Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.5 pollution of 45 global megacities in 2013, based on mass concentration from ...official monitoring networks and composition data reported in the literature. The results showed that the five most polluted megacities were Delhi, Cairo, Xi'an, Tianjin and Chengdu, all of which had an annual average concentration of PM2.5 greater than 89μg/m3. The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10μg/m3. Spatial distribution indicated that the highly polluted megacities are concentrated in east-central China and the Indo-Gangetic Plain. Organic matter and SNA (sum of sulfate, nitrate and ammonium) contributed 30% and 36%, respectively, of the average PM2.5 mass for all megacities. Notable seasonal variation of PM2.5 polluted days was observed, especially for the polluted megacities of China and India, resulting in frequent heavy pollution episodes occurring during more polluted seasons such as winter. Marked differences in PM2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM2.5 pollution of those megacities mainly in Asia.
•PM2.5 pollution in 45 megacities in 2013 was compared.•The megacities in east-central China and the Indo-Gangetic Plain were most polluted.•Organic matter and sulfate, nitrate and ammonium dominated the composition of PM2.5 of global megacities.•Heavy polluted days occurred in winter and in Asia megacities.
Fucoxanthin is abundant in seaweed and is considered as a powerful antioxidant. It has been proposed to possess anti-cancer, anti-obesity and anti-diabetes effects. However, its roles in brain injury ...models have not been fully understood. The objective of this study was to investigate the neuroprotection of fucoxanthin in models of traumatic brain injury (TBI) and the role of the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant-response element (ARE) and Nrf2-autophagy pathways in the putative neuroprotection. We found that fucoxanthin alleviated TBI-induced secondary brain injury, including neurological deficits, cerebral edema, brain lesion and neuronal apoptosis. Moreover, the up-regulation of malondialdehyde (MDA) and the activity of glutathione peroxidase (GPx) were reversed by fucoxanthin treatment. Furthermore, our in vitro studies demonstrated that fucoxanthin increased the neuron survival and reduced the reactive oxygen species (ROS) level. In addition, fucoxanthin activated the Nrf2-ARE pathway and autophagy both in vivo and in vitro, which was proven by the results of immunohistochemistry, western blot and electrophoretic mobility shift assay (EMSA). However, fucoxanthin failed to provide neuroprotection and activated autophagy following TBI in Nrf2
mice. In conclusion, our studies indicated that fucoxanthin provided neuroprotective effects in models of TBI, potentially via regulation of the Nrf2-ARE and Nrf2-autophagy pathways.
Untangling “NETosis” from NETs Yousefi, Shida; Stojkov, Darko; Germic, Nina ...
European journal of immunology,
February 2019, Letnik:
49, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Neutrophil extracellular trap (NET) formation is a cellular function of neutrophils that facilitates the immobilization and killing of invading microorganisms in the extracellular milieu. To form ...NETs, neutrophils release a DNA scaffold consisting of mitochondrial DNA binding granule proteins. This process does not depend on cell death, but requires glycolytic ATP production for rearrangements in the microtubule network and F‐actin. Such cytoskeletal rearrangements are essential for both mitochondrial DNA release and degranulation. However, the formation of NETs has also been described as a distinct form of programed, necrotic cell death, a process designated “NETosis.” Necrotic cell death of neutrophils is associated with the permeabilization of both plasma and nuclear membranes resulting in a kind of extracellular cloud of nuclear DNA. The molecular mechanisms eliciting necrotic neutrophil death have been investigated and appear to be different from those responsible for NET formation following mitochondrial DNA release. Here, we discriminate between the mechanisms responsible for the release of mitochondrial versus nuclear DNA and address their respective functions. Our aim is to clarify existing differences of opinion in the fields of NET formation and neutrophil death.
NETs are formed by activated neutrophils releasing mtDNA and granule proteins. This process requires an active NADPH oxidase and glycolytic ATP production for rearrangements of the cytoskeleton network in order to relocate granules and mitochondria.
We will perform the systematic review to evaluate the effect of applying concentrated growth factor (CGF) on relieving postoperative complications and promoting wound healing following mandibular ...third molar extraction.
The PubMed, Web of Science, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang Database, China Biology Medicine Disc (CBM), and VIP Databases will be comprehensively searched up to May 31, 2024. Randomized controlled trials (RCTs) examining the application of CGF after mandibular third molar extraction will be included. The protocol was registered in PROSPERO, and the registration ID was CRD42023463234. Two reviewers will conduct the literature search, eligible study selection, data extraction, and bias risk assessment (using the Cochrane Risk of Bias 2.0 tool). Data analysis will be performed with RevMan software (version 5.4).
The results of this study will be available in a peer-reviewed journal.
Our study will provide scientific evidence regarding the efficacy of applying CGF in mandibular third molar extraction.
Thanks to the rapid development in mobile vehicles and wireless technologies, the Internet of Vehicles (IoV) has become an attractive application that can provide a large number of mobile services ...for drivers. Vehicles can be informed of the mobile position, direction, speed, and other real-time information of nearby vehicles to avoid traffic jams and accidents. However, the environments of IoV could be dangerous in the absence of security protections. Due to the openness and self-organization of IoV, there are enormous malicious attackers. To guarantee the safety of mobile services, we propose an effective decentralized authentication mechanism for IoV on the basis of the consensus algorithm of blockchain technology. The simulation under the veins framework is carried out to verify the feasibility of the scheme in reducing the selfish behavior and malicious attacks in IoV.
Industrial synthesis is driven by a delicate balance of the value of the product against the cost of production. Catalysts are often employed to ensure product turnover is economically favorable by ...ensuring energy use is minimized. One method, which is gaining attention, involves cooperative catalytic systems. By inserting a flexible polymer into a metal–organic framework (MOF) host, the advantages of both components work synergistically to create a composite that efficiently fixes carbon dioxide to transform various epoxides into cyclic carbonates. The resulting material retains high yields under mild conditions with full reusability. By quantitatively studying the kinetic rates, the activation energy was calculated, for a physical mixture of the catalyst components to be about 50 % higher than that of the composite. Through the unification of two catalytically active components, a new opportunity opens up for the development of synergistic systems in multiple applications.
More than the sum of its parts: Two catalytically active components, a metal–organic framework (MOF) host and an ionic polymer, are combined into a single material. They synergistically work together lowering the energy barrier of a reaction, further than a mixture of the individual components. This process is demonstrated by the fixation of carbon dioxide with epoxides, forming industrially relevant cyclic carbonates.
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