Adsorption is essential for many processes on surfaces; therefore, an accurate prediction of adsorption properties is demanded from both fundamental and technological points of view. Particularly, ...identifying the intrinsic determinants of adsorption energy has been a long-term goal in surface science. Herein, we propose a predictive model for quantitative determination of the adsorption energies of small molecules on metallic materials and oxides, by using a linear combination of the valence and electronegativity of surface atoms and the coordination of active sites, with the corresponding prefactors determined by the valence of adsorbates. This model quantifies the effect of the intrinsic properties of adsorbates and substrates on adsorbate-substrate bonding, derives naturally the well-known adsorption-energy scaling relations, and accounts for the efficiency and limitation of engineering the adsorption energy and reaction energy. All involved parameters are predictable and thus allow the rapid rational design of materials with optimal adsorption properties.
This paper describes the development and implementation of a robust high-accuracy ultrasonic indoor positioning system (UIPS). The UIPS consists of several wireless ultrasonic beacons in the indoor ...environment. Each of them has a fixed and known position coordinate and can collect all the transmissions from the target node or emit ultrasonic signals. Every wireless sensor network (WSN) node has two communication modules: one is WiFi, that transmits the data to the server, and the other is the radio frequency (RF) module, which is only used for time synchronization between different nodes, with accuracy up to 1 μ s. The distance between the beacon and the target node is calculated by measuring the time-of-flight (TOF) for the ultrasonic signal, and then the position of the target is computed by some distances and the coordinate of the beacons. TOF estimation is the most important technique in the UIPS. A new time domain method to extract the envelope of the ultrasonic signals is presented in order to estimate the TOF. This method, with the envelope detection filter, estimates the value with the sampled values on both sides based on the least squares method (LSM). The simulation results show that the method can achieve envelope detection with a good filtering effect by means of the LSM. The highest precision and variance can reach 0.61 mm and 0.23 mm, respectively, in pseudo-range measurements with UIPS. A maximum location error of 10.2 mm is achieved in the positioning experiments for a moving robot, when UIPS works on the line-of-sight (LOS) signal.
•The COVID-19 emerged in Wuhan City and rapidly spread throughout China.•NLR exhibited the largest area under the curve, with the highest specificity and sensitivity.•Elevated NLR can be considered ...independent biomarkers for indicating poor clinical outcomes.
To accumulate evidence that indicated the key role played by virus-triggered inflammation in the 2019-novel coronavirus disease (COVID-19) which emerged in Wuhan City and rapidly spread throughout China.
Age, neutrophil(NEU)-to-lymphocyte (LYM) ratio (NLR), lymphocyte-to-monocyte (MON) ratio, platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) of 93 patients with laboratory confirmed COVID-19 were investigated and compared. The receiver operating characteristic curve was applied to determine the thresholds for five bio-markers, and their prognostic values were assessed via the Kaplan–Meier curve and multivariate COX regression models.
The median age was 46.4 years old, and 37cases were females. A total of 27.8% of patients had been to Wuhan, and 73.1% had contacted with people from Wuhan. Fever (83.8%) and cough (70.9%) were the two most common symptoms. Elevated NLR and age were significantly associated with illness severity. The binary logistic analysis identified elevated NLR (hazard risk HR 2.46, 95% confidence interval CI 1.98–4.57) and age (HR 2.52, 95% CI 1.65–4.83) as independent factors for poor clinical outcome of COVID-19. NLR exhibited the largest area under the curve at 0.841, with the highest specificity (63.6%) and sensitivity (88%).
Elevated age and NLR can be considered independent biomarkers for indicating poor clinical outcomes.
In the arthropod gut, commensal microbiota maintain the immune deficiency (Imd)/Relish pathway for expression of antimicrobial peptides, whereas pathogenic bacteria induce dual oxidase 2 (Duox2) for ...production of extracellular microbicidal reactive oxygen species (ROS). The Imd/Relish pathway and the Duox2/ROS system are regarded as independent systems. Here, we report that these two systems are bridged by the tumor necrosis factor (TNF) ortholog PcEiger in the red swamp crayfish Procambarus clarkii. PcEiger expression is induced by commensal bacteria or the Imd/Relish pathway. PcEiger knockdown alters bacterial abundance and community composition due to variations in the oxidative status of the intestine. PcEiger induces Duox2 expression and ROS production by regulating the activity of the transcription factor Atf2. Moreover, PcEiger mediates regulation of the Duox2/ROS system by commensal bacteria and the Imd/Relish pathway. Our findings suggest that the Imd/Relish pathway regulates the Duox2/ROS system via PcEiger in P. clarkii, and they provide insights into the crosstalk between these two important mechanisms for arthropod intestinal immunity.
Synopsis
A new link between the Imd/Relish pathway and the Duox2/ROS system by PcEiger provides insights into the crosstalk between two critical intestinal immune mechanisms in the red swamp crayfish Procambarus clarkii.
The Imd/Relish pathway regulates the expression of PcEiger in the intestine of the red swamp crayfish regardless of the presence of pathogenic bacteria.
PcEiger stimulates intestinal Duox2 expression and ROS production.
PcEiger mediates regulation of the Duox2/ROS system by the Imd/Relish pathway.
A new link between the Imd/Relish pathway and the Duox2/ROS system by PcEiger provides insights into the crosstalk between two critical intestinal immune mechanisms in the red swamp crayfish Procambarus clarkii.
Recently, ambient electrochemical N2 fixation has gained great attention. However, the commercial Pt‐based electrocatalyst hardly shows its potential in this field. Herein, it is found that the ...isolated Pt sites anchored on WO3 nanoplates exhibit the optimum electrochemical NH3 yield rate (342.4 µg h−1 mg−1Pt) and Faradaic efficiency (31.1%) in 0.1 m K2SO4 at −0.2 V versus RHE, which are about 11 and 15 times higher than their nanoparticle counterparts, respectively. The mechanistic analysis indicates that N2 conversion to NH3 follows an alternating hydrogenation pathway, and positively charged isolated Pt sites with special Pt−3O structure can favorably chemisorb and activate the N2. Furthermore, the hydrogen evolution reaction can be greatly suppressed on isolated Pt sites decorated WO3 nanoplates, which guarantees the efficient going‐on of nitrogen reduction reaction.
Isolated Pt atoms anchored on WO3 nanoplates exhibit highly active for ambient ammonia electrosynthesis, which is ascribed to facilitated chemisorption and activation of nitrogen and effective suppression for hydrogen evolution reaction (HER), immensely enhancing NH3 yield rate and Faradic efficiency. This groundbreaking research presents Pt‐based nanocatalysts for electroreduction of nitrogen and provides an idea for the HER depression.
This paper comprehensively reviews the state-of-the-art development in formation control of small satellites. Satellite formation flying, distributed satellite systems, and fractionated satellite ...formation are discussed first. Various formation control architectures and methods of small satellites are then introduced, including the leader-following method, the behavior-based method, the virtual structure method, the cyclic pursuit method, the artificial potential function method, the algebraic graph method, and the noncontact force method. Coordinative control of multiple small satellites is also reviewed, covering coordinative control of satellite formation, coordinative attitude control of satellite formation, and coordinative coupled attitude and orbit control of satellite formation. The achievements and development trends of the formation control of small satellites are considered and analyzed.
The demand for lithium batteries with energy densities beyond those of lithium-ion has driven the recent studies on lithium metal anode. High-efficiency electrochemical cycling of lithium requires ...improved lithium deposition morphology and reduced parasitic reactions between lithium and the liquid electrolyte. A protective layer on lithium metal is expected to reduce contact between lithium metal and the organic solvent, exert compressive mechanical force on the anode, and improve the selectivity and uniformity of lithium ion transport at the electrode surface. This review covers recent advancements in this topic. We first establish the design criteria for an effective coating followed by a brief description of the methods for depositing the layer, characterizing its structure and morphology, and evaluating its electrochemical performance. Our discussion of the literature is organized on resultant layer composition and corresponding ion conduction mechanisms. In the case of polymeric materials, the polarity difference between the polymer and electrolyte solvents determines the degree of swelling and selectivity of lithium ion transport. We conclude by advocating for the need of increased mechanistic study for the functioning mechanism, improved understanding of layer degradation, and demonstration of the protective function in realistic cell environment, namely lean electrolytes and coupled with appropriate cathodes.
•This review covers recent advancements in protective coatings for Li metal anode.•The design criteria for an effective coating are proposed.•Ion conduction mechanisms of inorganic and polymeric coatings are discussed.•Demonstration of the protective function in realistic cell condition is advocated.
Phosphorene, also known as single- or few-layer black phosphorus (FLBP), is a new member of the two-dimensional (2D) material family and has attracted significant attention in recent years for ...applications in optoelectronics, energy storage and biomedicine due to its unique physicochemical properties and excellent biocompatibility. FLBP is regarded as a potential biological imaging agent for cancer diagnosis due to its intrinsic fluorescence (FL) and photoacoustic (PA) properties and negligible cytotoxicity. FLBP-based photothermal and photodynamic therapies have emerged with excellent anti-tumour therapeutic efficacies due to their unique physical properties, such as near-infrared (NIR) optical absorbance, large extinction coefficients, biodegradability and reactive oxygen species (ROS) or heat generation upon light irradiation. Furthermore, FLBP is a promising drug delivery platform because of its high drug-loading capacity due to its puckered layer structure with an ultralarge surface area, and FLBP is size-controllable with facile surface chemical modification. Because of the marked advantages of FLBP nanomaterials in biomedical applications, an overview of the latest progress and paradigms of FLBP-based nanoplatforms for multidisciplinary biomedical applications is presented in this tutorial review.
Enhanced glycolysis in cancer cells has been linked to cell protection from DNA damaging signals, although the mechanism is largely unknown. The 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 ...(PFKFB3) catalyzes the generation of fructose-2,6-bisphosphate, a potent allosteric stimulator of glycolysis. Intriguingly, among the four members of PFKFB family, PFKFB3 is uniquely localized in the nucleus, although the reason remains unclear. Here we show that chemotherapeutic agent cisplatin promotes glycolysis, which is suppressed by PFKFB3 deletion. Mechanistically, cisplatin induces PFKFB3 acetylation at lysine 472 (K472), which impairs activity of the nuclear localization signal (NLS) and accumulates PFKFB3 in the cytoplasm. Cytoplasmic accumulation of PFKFB3 facilitates its phosphorylation by AMPK, leading to PFKFB3 activation and enhanced glycolysis. Inhibition of PFKFB3 sensitizes tumor to cisplatin treatment in a xenograft model. Our findings reveal a mechanism for cells to stimulate glycolysis to protect from DNA damage and potentially suggest a therapeutic strategy to sensitize tumor cells to genotoxic agents by targeting PFKFB3.
Functionalization of hydrogen‐bonded organic frameworks (HOFs) for specific applications has been a long‐lasting challenge in HOF materials. Here, an efficient way to integrate functional species in ...the HOF structure through constructing an anionic framework is presented. The obtained HOFs, taking PFC‐33 (PFC = porous materials from FJIRSM,CAS) as an example, integrate a porphyrin photosensitizer as a porous backbone and a commercial biocide as counterions in the structure. The permanent channels and the electrostatic interaction between the framework and the counterions provide PFC‐33 ion‐responsive biocide‐release behavior in various physiological environments, thus exhibiting synergistic photodynamic and chemical antimicrobial efficiency. The unbonded carboxyl groups residing on the HOF surface further allow for manipulating the interfacial interaction between the PFC‐33 and the polymer matrix for membrane fabrication. Therefore, a polyHOF membrane with high stability, desired flexibility, and good permeability is obtained, which demonstrates noticeable bacterial inhibition toward Escherichia coli. This study may shed light on the functionalization of HOF materials for broad application potentials.
The functionalization of hydrogen‐bonded organic frameworks (HOFs) can be achieved in a porphyrin‐based anionic HOF structure, endowing the material with synergistic photodynamic and chemical antimicrobial efficacy. By further taking advantage of the unbonded carboxyl groups on the HOF particle surface, a freestanding flexible membrane that shows high permeability, good stability, and excellent antibacterial activity is successfully fabricated.
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