Graphene plasmons are known to offer an unprecedented level of confinement and enhancement of electromagnetic field. They are hence amenable to interacting strongly with various other excitations ...(for example, phonons) in their surroundings and are an ideal platform to study the properties of hybrid optical modes. Conversely, the thermally induced motion of particles and quasiparticles can in turn interact with electronic degrees of freedom in graphene, including the collective plasmon modes via the Coulomb interaction, which opens up new pathways to manipulate and control the behavior of these modes. This study demonstrates tunable electrothermal control of coupling between graphene mid‐infrared (mid‐IR) plasmons and IR active optical phonons in silicon nitride. This study utilizes graphene nanoribbons functioning as both localized plasmonic resonators and local Joule heaters upon application of an external bias. In the latter role, they achieve up to ≈100 K of temperature variation within the device area. This study observes increased modal splitting of two plasmon–phonon polariton hybrid modes with temperature, which is a manifestation of increased plasmon–phonon coupling strength. Additionally, this study also reports on the existence of a thermally excited hybrid plasmon–phonon mode. This work can open the door for future optoelectronic devices such as electrically switchable graphene mid‐infrared plasmon sources.
Thermally induced phonons can interact with the collective plasmon modes in graphene via the Coulomb interactions, opening up new pathways to manipulate the behavior of the phonon–plasmon hybrid modes. Utilizing graphene nanoribbons as both plasmonic resonators and Joule heaters, graphene plasmons are electrothermally excited, which may have implications for devices such as electrically switchable graphene plasmon sources.
Recently, hip-hop pedagogy or Hip-Hop Based Education (HHBE) have become buzz words in the academic and public debate around hip-hop. However, we found that most definitions of hip-hop pedagogy are ...missing the concept of pedagogy itself. One consequence of failing to adequately explain the concept of pedagogy is that it may lead future hip-hop researchers, students, and teachers inadvertently to disseminate misinformation or foster unclear thinking by using "hip-hop pedagogy" in inaccurate or vague ways. For these reasons, it is important to have a shared understanding of hip-hop pedagogy. In this article, we present three updated, expanded definitions of hip-hop pedagogy with the potential for widespread acceptance. These definitions aim to convey in the simplest terms what hip-hop pedagogy is for the purpose of informing educators and preparing them to use data.
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•The MOF-based adsorbent with QuEChER-oriented solvent adaptability and selectivity was designed and produced.•The similarity of structures and biological effects of targets was found ...by cheminformatics.•For anti-viral drugs, MOF-based adsorbent now spans from aqueous to organic solution.
Due to the recent epidemic of viral diseases, the use and discharge of antiviral drugs and related compounds have increased, leading to the accumulation issues in living organisms. QuEChER-based methods are widely used in the pretreatment of biological samples. Hence it is important to develop adsorbents that are compatible with QuEChER-related organic solvents, and simultaneously exhibit high selectivity for enriching targeted compounds. In this study, a uracil structure (an RNA fragment) was introduced into the metal–organic framework (MOF) by one-pot synthesis at room temperature. The as-prepared MOF adsorbent showed good performance in acetonitrile, particularly for compounds with purine-like structures, such as anti-COVID-19 drug favipiravir and its analogues. The similarity of structures and drug-like properties were collected to analyze the common features and biological effects of these captured compounds by cheminformatics. Using shrimp meat extract as the sample matrix, the MOF-based membrane solid-phase extraction (MSPE) combined with high performance liquid chromatography (HPLC) achieved a limit of detection (LOD) at ppb level under a UV detector. This work introduced a novel approach to tuning the solvent adaptability and selectivity of MOF-based adsorbent for QuEChER applications. Along with our previous work, the solvent adaptability of MOF-based adsorbent now spans from aqueous to organic solution, offering a new option for the sample preparation of such contaminants.
Prenatal imaging phenotypes and genotypes were analyzed in 13 cases prenatally diagnosed with Joubert syndrome (JS), all of which underwent magnetic resonance imaging (MRI), ultrasound, and genetic ...testing. Prenatal MRI diagnosed 10 cases as JS with a typical molar tooth sign (MTS), while prenatal ultrasound diagnosed or suspiciously diagnosed 11 cases as JS with typical or mild MTS in 10 cases. Mutations in JS-related genes and other prenatal JS imaging phenotypes were identified in 10 cases, including OFD1 in two cases cerebellar vermis (CV) absence, posterior fossa dilation, ventriculomegaly, polydactyly, malformations of cortical development (MCD), and persistent left superior vena cava, TMEM67 in two cases (CV absence, polydactyly, hyperechoic kidneys or polycystic kidneys, posterior fossa dilation, and ventriculomegaly), CC2D2A in two cases (CV absence, polydactyly, MCD, agenesis of the corpus callosum, encephalocele and hydrocephalus, ventriculomegaly, and posterior fossa dilation), RPGRIP1L in one case (CV absence), TCTN3 in one case (CV absence, polydactyly, MCD, and posterior fossa dilation), CEP290 in one case (CV absence and polycystic kidney), and NPHP1 in one case (CV absence). The prenatal diagnosis of JS presents a number of challenges, including the variants of unknown significance, the lack of functional assessment in prenatal imaging, unclear phenotype–genotype relationships in prenatal evaluation, and the incorrect identification of the JS hallmark, the MTS, in prenatal imaging, especially on ultrasound. Although combined MRI, ultrasound, and exome sequencing could help improve the prenatal diagnosis of JS, there still exist significant challenges.
Understanding how natural hybridization and polyploidizations originate in plants requires identifying potential diploid ancestors. However, cryptic plant species are widespread, particularly in ...Ceratopteris (Pteridaceae). Identifying Ceratopteris cryptic species with different polyploidy levels is a challenge because Ceratopteris spp. exhibit high degrees of phenotypic plasticity. Here, two new cryptic species of Ceratopteris, Ceratopteris chunii and Ceratopteris chingii, are described and illustrated. Phylogenetic analyses reveal that each of the new species form a well-supported clade. C. chunii and C. chingii are similar to Ceratopteris gaudichaudii var. vulgaris and C. pteridoides, respectively, but distinct from their relatives in the stipe, basal pinna of the sterile leaf or subelliptic shape of the fertile leaf, as well as the spore surface. In addition, chromosome studies indicate that C. chunii and C. chingii are both diploid. These findings will help us further understand the origin of Ceratopteris polyploids in Asia.
Comprehending the spatial–temporal characteristics, contributions, and evolution of driving factors in agricultural non-CO
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greenhouse gas (GHG) emissions at a macro level is pivotal in pursuing ...temperature control objectives and achieving China’s strategic goals related to carbon peak and carbon neutrality. This study employs the Intergovernmental Panel on Climate Change (IPCC) carbon emissions coefficient method to comprehensively evaluate agricultural non-CO
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GHG emissions at the provincial level. Subsequently, the contributions and spatial–temporal evolution of six driving factors derived from the Kaya identity were quantitatively explored using the Logarithmic Mean Divisia Index (LMDI) and Geographical and Temporal Weighted Regression (GTWR) methods. The results revealed that the distribution of agricultural non-CO
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GHG emissions is shifting from the central provinces to the northwest regions. Moreover, the dominant driving factors of agricultural non-CO
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GHG emissions were primarily economic factor (EDL) with positive impact (cumulative promotion is 2939.61 million metric tons (Mt)), alongside agricultural production efficiency factor (EI) with negative impact (cumulative reduction is 2208.98 Mt). Influence of EDL diminished in the eastern coastal regions but significantly impacted underdeveloped regions such as the northwest and southwest. In the eastern coastal regions, EI gradually became the absolute dominant driver, demonstrating a rapid reduction effect. Additionally, a declining birth rate and rural-to-urban population migration have significantly amplified the driving effects of the population factor (RP) at a national scale. These findings, in conjunction with the disparities in geographic and socioeconomic development among provinces, can serve as a guiding framework for the development of a region-specific roadmap aimed at reducing agricultural non-CO
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GHG emissions.
A surface component activity model was proposed to predict the sorbent concentration (Cs) dependence of partition coefficient, and a semi-empirical Cs-dependent function of partition coefficient was ...derived. Display omitted
► A surface component activity (SCA) model to describe the Cs-effect of partition coefficient was proposed. ► A semi-empirical Cs-dependent function of partition coefficient was derived. ► The function can predict the Cs-dependence of partition coefficient for both organic compounds and heavy metals.
During studying the distribution of pollutants between the aqueous and particulate phases, an anomalous Cs-effect phenomenon, namely, the experimentally measured partition coefficient (Kp) value of a given system decreased with increasing the sorbent concentration (Cs), was observed in a number of adsorption systems. Classical Langmuir model cannot predict the Cs-effect. In this paper, a surface component activity (SCA) model was proposed, which suggests that surface component (adsorption site or adsorbed solute) activity coefficient is a function of Cs because of the existence of adsorbent particle–particle interactions. A semi-empirical Cs-dependent function of partition coefficient was derived, and it can predict the Cs-dependence of partition coefficient for both organic compounds and heavy metals.
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•A comprehensive phytochemical investigation on the endangered Cephalotaxus oliveri.•Six cephalotaxine-type alkaloids and three C31-biflavonoids were newly obtained.•Alkaloids 1–4 are ...the first natural cephalotaxine esters in the N-oxide form.•Some isolates showed cytotoxicities with IC50 values ranging from 3 nM to 0.1 μM.•21 polyketides were isolated from an endophyte associated with the title plant.
Rare and endangered plants (REPs) and their associated endophytes survived in unique habitats are promising sources for natural product-derived drug discovery. In this study, six new (cephaloverines A–F, 1–6, resp.) and 16 known (11–26) cephalotaxine-type alkaloids, together with three new (oliverbiflavones A–C, 7–9, resp.) and 11 known (27–37) biflavonoids were isolated and characterized from the twigs and leaves of Cephalotaxus oliveri, an endangered plant endemic to China. Meanwhile, a preliminary investigation on the secondary metabolites from a selected fungal endophyte (i.e., Alternaria alternate Y-4–2) associated with the title plant led to the isolation of 21 structurally distinct polyketides including one new dimeric xanthone (10). The new structures (1–10) with the absolute configurations were determined by detailed spectroscopic analyses, electronic circular dichroism (ECD) or Na2MoO4-induced ECD, the modified Mosher’s method, and some chemical transformations. Compounds 1–4 are the first representatives of naturally occurring N-oxides of cephalotaxine esters, while compounds 7–9 have a special structural feature of having a C-methylated biflavonoid skeleton. The Cephalotaxus alkaloids with ester side-chains at C-3 (1–6, 13–22, and 26) and four biflavonoids (27–29 and 34) were found to show pronounced cytotoxicities against a small panel of human cancer cell lines (A549, NCI-H460, HL60, NCI-H929, and RPMI-8226), with IC50 values mainly ranging from 0.003 to 9.34 μM. The most potent compound, deoxyharringtonine (16), generally exhibited IC50 values less than 10 nM. The structure–activity relationship (SAR) of the aforementioned Cephalotaxus alkaloids was briefly discussed.
We conducted combined gas-phase anion photoelectron spectroscopy and density functional theory studies on nucleobase-silver complexes. The most probable structures of the nucleobase-Ag– complexes ...were determined by comparing the theoretical calculations with the experimental measurements. The vertical detachment energies (VDEs) of uracil-Ag–, thymine-Ag–, cytosine-Ag–, and guanine-Ag– were estimated to be 2.18 ± 0.08, 2.11 ± 0.08, 2.04 ± 0.08, and 2.20 ± 0.08 eV, respectively, based on their photoelectron spectra. Adenine-Ag– has two isomers coexisting in the experiment; the experimental VDEs of the two isomers are 2.18 and 2.53 eV, respectively. In the most probable isomers of nucleobases-Ag–, uracil, thymine, and cytosine interact with Ag– anion via N–H···Ag and C–H···Ag hydrogen bonds, while adenine and guanine interact with Ag– anion through two N–H···Ag hydrogen bonds. The N–H···Ag hydrogen bonds can be characterized as medium or strong hydrogen bonds. It is found that binding sites of the Ag anion to the nucleobases are affected by the deprotonation energies and the steric effects of two adjacent X–H groups.
Abstract
Mutations and transient conformational movements of the receptor binding domain (RBD) that make neutralizing epitopes momentarily unavailable present immune escape routes for severe acute ...respiratory syndrome coronavirus 2 (SARS-CoV-2). To mitigate viral escape, we developed a cocktail of neutralizing antibodies (NAbs) targeting epitopes located on different domains of spike (S) protein. Screening of a library of monoclonal antibodies generated from peripheral blood mononuclear cells of COVID-19 convalescent patients yielded potent NAbs, targeting the N-terminal domain (NTD) and RBD domain of S, effective at nM concentrations. Remarkably, a combination of RBD-targeting NAbs and NTD-binding NAbs, FC05, enhanced the neutralization potency in cell-based assays and an animal model. Results of competitive surface plasmon resonance assays and cryo-electron microscopy (cryo-EM) structures of antigen-binding fragments bound to S unveil determinants of immunogenicity. Combinations of immunogens, identified in the NTD and RBD of S, when immunized in rabbits and macaques, elicited potent protective immune responses against SARS-CoV-2. More importantly, two immunizations of this combination of NTD and RBD immunogens provided complete protection in macaques against a SARS-CoV-2 challenge, without observable antibody-dependent enhancement of infection. These results provide a proof of concept for neutralization-based immunogen design targeting SARS-CoV-2 NTD and RBD.
Immunogens identified in the N-terminal domain and receptor binding domain of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein using a cocktail of non-competing neutralizing antibodies when injected in macaques elicited a potent protective efficacy against SARS-CoV-2.
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