In this work, bilinear residual network method is proposed to solve nonlinear evolution equations. The activation function in final layer of deep neural network cannot interact with the neuron inside ...the deep neural network, but the residual network can transfer the input layer to the activation function in final layer to realize the interaction within the network. This reduces the complexity of the model and gives more interactive results. The steps of solving the exact analytical solution through the residual network are given. The rogue wave solution of Caudrey–Dodd–Gibbon–Kotera–Sawada-like equation is obtained by using the bilinear residual network method. Characteristic plots and dynamic analysis of these rogue waves are given.
Abstract
Background
China has been using inactivated coronavirus disease 2019 (COVID-19) vaccines as primary series and booster doses to protect the population from severe to fatal COVID-19. We ...evaluated primary and booster vaccine effectiveness (VE) against Omicron BA.2 infection outcomes.
Methods
This was a 13-province retrospective cohort study of quarantined close contacts of BA.2-infected individuals. Outcomes were BA.2 infection, COVID-19 pneumonia or worse, and severe/critical COVID-19. Absolute VE was estimated by comparison with an unvaccinated group.
Results
There were 289 427 close contacts ≥3 years old exposed to Omicron BA.2 cases; 31 831 turned nucleic acid amplification test–positive during quarantine, 97.2% with mild or asymptomatic infection, 2.6% with COVID-19 pneumonia, and 0.15% with severe/critical COVID-19. None died. Adjusted VE (aVE) against any infection was 17% for primary series and 22% when boosted. Primary series aVE in adults >18 years was 66% against COVID-19 pneumonia or worse and 91% against severe/critical COVID-19. Booster dose aVE was 74% against pneumonia or worse, and 93% against severe/critical COVID-19.
Conclusions
Inactivated COVID-19 vaccines provided modest protection from infection, very good protection against pneumonia, and excellent protection against severe/critical COVID-19. Booster doses are necessary to provide strongest protection.
China-produced inactivated COVID-19 absolute vaccine effectiveness (VE) levels against Omicron BA.2 infection, pneumonia or worse, and severe COVID-19 were 17%, 66%, and 91%; boosted VEs were 22%, 74%, and 93%. Inactivated vaccines were highly effective against severe COVID-19 in China's then infection-naive population.
Observation of chiral phonons Zhu, Hanyu; Yi, Jun; Li, Ming-Yang ...
Science (American Association for the Advancement of Science),
02/2018, Letnik:
359, Številka:
6375
Journal Article
Recenzirano
Odprti dostop
Chirality reveals symmetry breaking of the fundamental interaction of elementary particles. In condensed matter, for example, the chirality of electrons governs many unconventional transport ...phenomena such as the quantum Hall effect. Here we show that phonons can exhibit intrinsic chirality in monolayer tungsten diselenide. The broken inversion symmetry of the lattice lifts the degeneracy of clockwise and counterclockwise phonon modes at the corners of the Brillouin zone. We identified the phonons by the intervalley transfer of holes through hole-phonon interactions during the indirect infrared absorption, and we confirmed their chirality by the infrared circular dichroism arising from pseudoangular momentum conservation. The chiral phonons are important for electron-phonon coupling in solids, phonon-driven topological states, and energy-efficient information processing.
The asymmetric catalytic addition of linear Grignard reagents to ketones has been a long‐standing challenge in organic synthesis. Herein, a novel family of PNP ligands (W‐Phos) was designed and ...applied in copper‐catalyzed asymmetric addition of linear Grignard reagents to aryl alkyl ketones, allowing facile access to versatile chiral tertiary alcohols in good to high yields with excellent enantioselectivities (up to 94 % yield, 96 % ee). The process can also be used to synthesize chiral allylic tertiary alcohols from more challenging α,β‐unsaturated ketones. Notably, the potential utility of this method is demonstrated in the gram‐scale synthesis and modification of various densely functionalized medicinally relevant molecules.
A novel family of PNP ligands (W‐Phos) was designed and applied in the copper‐catalyzed asymmetric addition of linear Grignard reagents to ketones, allowing ready access to versatile chiral tertiary alcohols in high yields and with excellent enantioselectivities.
Designing and modulating the local structure of metal sites is the key to gain the unique selectivity and high activity of single metal site catalysts. Herein, we report strain engineering of curved ...single atomic iron‐nitrogen sites to boost electrocatalytic activity. First, a helical carbon structure with abundant high‐curvature surface is realized by carbonization of helical polypyrrole that is templated from self‐assembled chiral surfactants. The high‐curvature surface introduces compressive strain on the supported Fe−N4 sites. Consequently, the curved Fe−N4 sites with 1.5 % compressed Fe−N bonds exhibit downshifted d‐band center than the planar sites. Such a change can weaken the bonding strength between the oxygenated intermediates and metal sites, resulting a much smaller energy barrier for oxygen reduction. Catalytic tests further demonstrate that a kinetic current density of 7.922 mA cm−2 at 0.9 V vs. RHE is obtained in alkaline media for curved Fe−N4 sites, which is 31 times higher than that for planar ones. Our findings shed light on modulating the local three‐dimensional structure of single metal sites and boosting the catalytic activity via strain engineering.
Compressive strain engineering of curved single atomic iron‐nitrogen sites could boost the catalytic activity for electrocatalytic oxygen reduction reaction.
Glioblastoma tumors exhibit extensive inter- and intratumoral heterogeneity, which has contributed to the poor outcomes of numerous clinical trials and continues to complicate the development of ...effective therapeutic strategies. Most in vitro models do not preserve the cellular and mutational diversity of parent tumors and often require a lengthy generation time with variable efficiency. Here, we describe detailed procedures for generating glioblastoma organoids (GBOs) from surgically resected patient tumor tissue using a chemically defined medium without cell dissociation. By preserving cell-cell interactions and minimizing clonal selection, GBOs maintain the cellular heterogeneity of parent tumors. We include details of how to passage and cryopreserve GBOs for continued use, biobanking and long-term recovery. In addition, we describe procedures for investigating patient-specific responses to immunotherapies by co-culturing GBOs with chimeric antigen receptor (CAR) T cells. It takes ~2-4 weeks to generate GBOs and 5-7 d to perform CAR T cell co-culture using this protocol. Competence with human cell culture, tissue processing, immunohistology and microscopy is required for optimal results.
Kushen （Radix Sophorae Flavescentis） has a long history of use for the treatment of tumors, inflammation and other diseases in traditional Chinese medicine. Compound Kushen Injection （CKI） is a ...mixture of natural compounds extracted from Kushen and Baituling （Rhizoma Smilacis Glabrae）. The main principles of CKI are matrine （MT） and oxymatrine （OMT） that exhibit a variety of pharmacological activities, including anti-inflammatory, anti-allergic, anti-viral, anti-fibrotic and cardiovascular protective effects. Recent evidence shows that these compounds also produce anti-cancer actions, such as inhibiting cancer cell proliferation, inducing cell cycle arrest, accelerating apoptosis, restraining angiogenesis, inducing cell differentiation, inhibiting cancer metastasis and invasion, reversing multidrug resistance, and preventing or reducing chemotherapy- and/or radiotherapy-induced toxicity when combined with chemotherapeutic drugs. In this review, we summarize recent progress in studying the anti-cancer activities of MT, OMT and CKI and their potential molecular targets, which provide clues and references for further study.
Four new electrocatalysts TM@g-C4N3 (TM = V, Tc, Os, Pt) of NRR obtained from high-throughput screening and first-principles calculations of 3d, 4d and 5d transition metal series.
Display omitted
...•The hierarchical high-throughput screening method was developed and applied.•The most active catalyst is V@g-C4N3 with onset potential as low as -0.37 V.•ΔEads(*N2) can be an descriptor to characterize the activity of catalysts.•The evolution trend of catalytic activity is consistent with that of d-band center.
The potential of TM atoms embedded g-C4N3 as a new class of electrocatalysts (TM@g-C4N3, TM = 3d, 4d and 5d transition metal) towards nitrogen reduction reaction (NRR) were systematically investigated through the combination of high-throughput screening and first-principles calculations. Among 30 candidate materials, TM@g-C4N3 (TM = V, Tc, Os, Pt) exhibited the highest activity for electrocatalytic N2 reduction to produce NH3. Particularly, V@g-C4N3 is identified as the most active catalyst for NRR with onset potential of −0.37 V. Interestingly, a volcano curve between Uonset (onset potential) and ΔEads(*N2) (the adsorption energy of N2) is established, and thus ΔEads(*N2) can be used as a descriptor to characterize the activity of catalysts. Among all investigated catalysts, the lowest onset potential of V@g-C4N3 can be attributed to its moderate adsorption energies for N2. After in-deep analysis of the intrinsic properties of the four catalysts, we found that the increasing order of catalytic activity is consistent with the increasing order of d-band center (εd) of the four catalysts. In addition, the excellent thermal stability of the four catalysts is verified via simulated annealing at 500 K for 10 ps. Furthermore, three catalysts TM@g-C4N3 (TM = V, Tc, Pt) demonstrate good selectivity. Therefore, V@g-C4N3 is a promising electrocatalyst for NRR. Our work opens the way for g-C4N3 as a new type of support to construct efficient single-atom catalyst for electrocatalytic ammonia synthesis. The predicted TM@g-C4N3 catalysts will provide useful guidance for experimental synthesis and rational design of catalysts in future.
Abstract
We herein disclose a simple and general method for the synthesis of chromendiones through Rh(III)‐catalyzed C−H functionalization/annulation reactions of nitrones with cyclic ...2‐diazo‐1,3‐diones by using nitrone group as a traceless directing group. This method exhibits high efficiency and broad functional group compatibility. The derivatization of these chromendiones has been also demonstrated to further strengthen the synthetic utility of the transformation.
Porous materials with well‐defined pore structures have received considerable attention in the past decades due to their unique structures and wide applications. Most porous materials such as ...zeolites, metal‐organic frameworks, covalent organic frameworks, and porous organic polymers are extended to infinite frameworks or networks by robust covalent or coordination bonds. Porous molecular cages composed of discrete molecules with permanent cavities are an emerging class of porous material and the discrete molecules assemble into solids by weak intermolecular interaction. In comparison to porous extended solids such as metal‐organic frameworks and covalent organic frameworks, porous molecular cage solids are generally soluble in organic solvents thus allowing solution processing, making them more convenient to apply in many fields. This review mainly focuses on the recent advances of application of porous molecular cages (porous organic cages and metal‐organic cages) for enantioselective recognition and separation from 2010 to present, including gas chromatography, capillary electrochromatography, chiral fluorescent recognition, chiral potentiometric sensing, and enantioselective adsorption. Furthermore, the two important family members of porous molecular cages, porous organic cages and metal‐organic cages, are also discussed.
PDF
