Explore the vast range of titles available.

Cyber-physical systems embed software into the physical world. They appear in a wide range of applications such as smart grids, robotics, and intelligent manufacturing. Cyber-physical systems have proved resistant to modeling due to their intrinsic complexity arising from the combination of physical and cyber components and the interaction between them. This study proposes a general framework for discovering cyber-physical systems directly from data. The framework involves the identification of physical systems as well as the inference of transition logics. It has been applied successfully to a number of real-world examples. The novel framework seeks to understand the underlying mechanism of cyber-physical systems as well as make predictions concerning their state trajectories based on the discovered models. Such information has been proven essential for the assessment of the performance of cyber-physical systems; it can potentially help debug in the implementation procedure and guide the redesign to achieve the required performance. Discovery of hybrid dynamical models for real-world cyber-physical systems remains a challenge. This paper proposes a general framework for automating mechanistic modeling of hybrid dynamical systems from observed data with low computational complexity and noise resilience.

Organic emitters with persistent phosphorescence have shown potential application in optoelectronic devices. However, rational design and phosphorescence tuning are still challenging. Here, a series of metal-free luminophores without heavy atoms and carbonyl groups from commercial/lab-synthesized carbazole and benzene were synthesized to realize tunable molecular emission from fluorescence to phosphorescence by simply substituent variation. All the molecules emit blue fluorescence in both solution and solid state. Upon removal of excitation source, the fluorinated luminophores show obvious phosphorescence. The lab-synthesized carbazole based molecules exhibit a huge lifetime difference to the commercially purchased ones due to the existence of isomer in the latter samples. The small energy gap between singlet and triplet state and low reorganization energy help enhance intersystem crossing to contribute to a more competitive radiative process from triplet to ground state. Blue and white organic light-emitting devices are fabricated by using fluorinated luminophore as emitting layer. Though organic emitters with room temperature phosphorescence (RTP) are attractive for various applications, realizing highly efficient and long lifetime emission remains a challenge. Here, the authors report the role of push-pull electronic effects on emission for organic RTP emitters.

Strategies for treating osteoarthritis (OA) have become a research focus because an effective treatment for OA is unavailable. The objective of this study was to explore the effects and underlying mechanisms of glutamine (Gln) in OA. First, the chondrocytes were identified and a standard IL-1β-induced OA model was established. After treatment with Gln or saline, the viability and apoptosis of chondrocytes were evaluated using a CCK-8 assay and flow cytometry analysis, which revealed that Gln can improve the IL-1β-induced OA cells. Meanwhile, Gln can enhance the expression of aggrecan and collagen II, which are protective proteins for articular cartilage. Instead, Gln inhibited the expression of matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-13 (MMP-13), which can degrade cartilage. To better understand the underlying mechanisms of Gln in IL-1β-induced chondrocytes, the classical OA pathways of JNK and NF-κB were examined at the protein and mRNA levels using western blot and qRT–PCR analyses. We found that JNK and NF-κB were downregulated gradually depending on the Gln dose and protective and destructive factors changed based on changes of JNK and NF-κB. The effects of high-dose Gln were more effective than low-dose. Moreover, Gln was applied to the animal OA model to check the effects in vivo. The results showed that Gln attenuated cartilage degeneration and decreased OARSI scores, which demonstrated that Gln can improve OA. The experiments showed that Gln can benefit mice with OA by inhibiting the JNK and NF-κB signaling pathways.

Compared with traditional manufacturing enterprises, intelligent manufacturing enterprises pay more attention to the investment of knowledge capital and technological capital. Taking 258 intelligent manufacturing listed companies in China from 2015 to 2020 as research samples, the paper selects the material capital, human capital, knowledge capital and technological capital of enterprises as the input variables of Cobb-Douglas production function. Considering that enterprises are often affected by spatial correlation, stochastic frontier panel model, spatial lag stochastic frontier panel model and dynamic spatial lag stochastic frontier panel model are constructed to measure capital allocation efficiencies of enterprises. The results show that all the factor capitals in the three models have a significant positive impact on enterprises’ performance, and the dual lag effect of time and space is significant. Moreover, it is more reasonable to use the dynamic spatial lag stochastic frontier panel model to estimate the parameters and measure capital allocation efficiencies. The development of intelligent manufacturing industry has significant space-time spillover effect among provinces. About 52.98% of intelligent manufacturing enterprises have high capital allocation efficiencies, but 12.04% still need to further optimize capital allocation. The gap between the actual performance of the sample enterprises and efficiency frontier is mainly due to technical ineffectiveness. From a regional perspective, the top ten enterprises with high capital allocation efficiencies are all in the eastern region, but the average of capital allocation efficiency is the highest in the western region, followed by the eastern and central regions.

Enantiomerically enriched indole-containing heterocycles play a vital role in bioscience, medicine, and chemistry. As one of the most attractive subtypes of indole alkaloids, highly substituted tetrahydro-γ-carbolines are the basic structural unit in many natural products and pharmaceuticals. However, the syntheses of tetrahydro-γ-carbolines with high functionalities from readily available reagents are significant challenging. In particular, the stereodivergent syntheses of tetrahydro-γ-carbolines containing multi-stereogenic centers remain quite difficult. Herein, we report an expedient and stereodivergent assembly of tetrahydro-γ-carbolines with remarkably high levels of stereoselective control in an efficient cascade process from aldimine esters and indolyl allylic carbonates via a synergistic Cu/Ir catalyst system. Control experiments-guided optimization of synergistic catalysts and mechanistic investigations reveal that a stereodivergent allylation reaction and a subsequent highly stereoselective iso -Pictet-Spengler cyclization are the key elements to success. Tetrahydro-γ-carbolines are the basic structural unit in many natural products and pharmaceuticals. Here, the authors report a synergistic Cu/Ir system to assemble chiral tetrahydro-γ-carbolines via a stereodivergent allylation followed by a stereoselective iso-Pictet-Spengler cyclization.

Most cationic vectors are difficult to avoid the fate of small interfering RNA (siRNA) degradation following the endosome-lysosome pathway during siRNA transfection. In this study, the endoplasmic reticulum (ER) membrane isolated from cancer cells was used to fabricate an integrative hybrid nanoplexes (EhCv/siRNA NPs) for improving siRNA transfection. Compared to the undecorated Cv/siEGFR NPs, the ER membrane-decorated EhCv/siRNA NPs exhibits a significantly higher gene silencing effect of siRNA in vitro and a better antitumor activity in nude mice bearing MCF-7 human breast tumor in vivo. Further mechanistic studies demonstrate that functional proteins on the ER membrane plays important roles on improving cellular uptake and altering intracellular trafficking pathway of siRNA. It is worth to believe that the ER membrane decoration on nanoplexes can effectively transport siRNA through the endosome-Golgi-ER pathway to evade lysosomal degradation and enhance the silencing effects of siRNA. The silencing efficiency of siRNA delivered by non-viral cationic vectors is limited due to endosomal/lysosomal degradation. Here, the authors develop endoplasmic reticulum-coated vesicles as a biomimetic vector for siRNA delivery and show that they improve inhibition of tumor growth in mice in vivo.

A bstract Event shape observables have been widely used for precision QCD studies at various lepton and hadron colliders. We present the most accurate calculation of the transverse-energy-energy correlation event shape variable in deep-inelastic scattering. In the framework of soft-collinear effective theory the cross section is factorized as the convolution of the hard function, beam function, jet function and soft function in the back-to-back limit. A close connection to TMD factorization is established, as the beam function when combined with part of the soft function is identical to the conventional TMD parton distribution function, and the jet function is the second moment of the TMD fragmentation function matching coefficient. We validate our framework by comparing the obtained LO and NLO leading singular distributions to the full QCD calculations in the back-to-back limit. We report the resummed transverse-energy-energy correlation distributions up to N 3 LL accuracy matched with the NLO cross section for the production of a lepton and two jets. Our work provides a new way to precisely study TMD physics at the future Electron-Ion Collider.

During the chlor-alkali process, in operation since the nineteenth century, electrolysis of sodium chloride solutions generates chlorine and sodium hydroxide that are both important for chemical manufacturing 1 – 4 . As the process is very energy intensive, with 4% of globally produced electricity (about 150 TWh) going to the chlor-alkali industry 5 – 8 , even modest efficiency improvements can deliver substantial cost and energy savings. A particular focus in this regard is the demanding chlorine evolution reaction, for which the state-of-the-art electrocatalyst is still the dimensionally stable anode developed decades ago 9 – 11 . New catalysts for the chlorine evolution reaction have been reported 12 , 13 , but they still mainly consist of noble metal 14 – 18 . Here we show that an organocatalyst with an amide functional group enables the chlorine evolution reaction; and that in the presence of CO 2 , it achieves a current density of 10 kA m −2 and a selectivity of 99.6% at an overpotential of only 89 mV and thus rivals the dimensionally stable anode. We find that reversible binding of CO 2 to the amide nitrogen facilitates formation of a radical species that plays a critical role in Cl 2 generation, and that might also prove useful in the context of Cl − batteries and organic synthesis 19 – 21 . Although organocatalysts are typically not considered promising for demanding electrochemical applications, this work demonstrates their broader potential and the opportunities they offer for developing industrially relevant new processes and exploring new electrochemical mechanisms. A study shows that an organocatalyst with an amide functional group, and carbon dioxide, can efficiently and selectively produce chlorine, potentially offering a low-cost and less energy intensive alternative to the chlor-alkali process.

Aims Acyl‐CoA synthetase long chain family member 4 (ACSL4) is closely related to tumor genesis and development in certain tissues. However, the function of ACSL4 in early brain injury (EBI) caused by subarachnoid hemorrhage (SAH) is unclear. In this study, we investigated the expression patterns and role of ACSL4 in SAH and post‐SAH EBI using a rat model of SAH. Methods The rat model of SAH was induced by autologous blood injection into the prechiasmatic cistern of rats. We also used two specific inhibitors of ferroptosis (Ferrostatin‐1 and Liproxstatin‐1) to investigate the role of ferroptosis in EBI. Results We found that ACSL4 levels in brain tissue increased significantly in post‐SAH EBI. Inhibiting the expression of ACSL4 using small interfering RNAs alleviated inflammation, blood‐brain barrier (BBB) impairment, oxidative stress, brain edema, and behavioral and cognitive deficits, and increased the number of surviving neurons, after SAH. Similar effects were obtained by suppressing ferroptosis. Conclusions ACSL4 exacerbated SAH‐induced EBI by mediating ferroptosis. These findings may provide a theoretical basis for potential therapy aimed at alleviating post‐SAH EBI. ACSL4 levels in brain tissue of rats increase significantly in EBI and brain damage after SAH could be reduced by down‐regulation of ACSL4. ACSL4 could trigger ferroptosis and aggravate brain damage via catalyzing lipid metabolism. It may provide a theoretical basis for potential therapy to alleviate EBI after SAH

The collagenases of Vibrio species, many of which are pathogens, have been regarded as an important virulence factor. However, there is little information on the structure and collagenolytic mechanism of Vibrio collagenase. Here, we report the crystal structure of the collagenase module (CM) of Vibrio collagenase VhaC and the conformation of VhaC in solution. Structural and biochemical analyses and molecular dynamics studies reveal that triple-helical collagen is initially recognized by the activator domain, followed by subsequent cleavage by the peptidase domain along with the closing movement of CM. This is different from the peptidolytic mode or the proposed collagenolysis of Clostridium collagenase. We propose a model for the integrated collagenolytic mechanism of VhaC, integrating the functions of VhaC accessory domains and its collagen degradation pattern. This study provides insight into the mechanism of bacterial collagenolysis and helps in structure-based drug design targeting of the Vibrio collagenase. The collagenolytic mechanism of Vibrio collagenase, a virulence factor, remains unclear. Here, the authors report the structure of Vibrio collagenase VhaC and propose the mechanism for collagen recognition and degradation, providing new insight into bacterial collagenolysis.