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A novel red phosphor Lu3(1-x)Sc2Ga3O12: xEu3+(0 ≤ x ≤ 0.3) was successfully prepared by high temperature solid state method. The Lu2.4Sc2Ga3O12: 0.2Eu3+ phosphor shows strong high internal quantum efficiency and thermal stability with values of 64.79 % and 87.0 %, respectively. Based on Lu2.4Sc2Ga3O12: 0.2Eu3+ phosphor, the partial replacement of Lu3+ ions in the host by Gd3+ / Y3+ ions changes the local crystal field environment of Eu3+ ions, resulting in wonderful changes in the luminous center, and the luminous intensity at 593 nm is increased by 3.66 and 3.54 times, respectively. The decay time of Eu3+ ions is analyzed from the perspective of dynamics, and the reasons for the enhancement of luminescence after partial replacement of Lu3+ ions are discussed in detail from two aspects of phosphor structure and crystal field effect around Eu3+ ions. In addition, with the substitution of Gd3+ / Y3+ ions, the thermal stability of the sample is 90.3 %/89.4 % with excellent low thermal quenching. The thermal quenching mechanism is described by combining Debye temperature and activation energy. The sample also has a high internal quantum efficiency IQE=79.03 % / 78.24 %. Finally, under the excitation of 365 nm chip, the phosphors of Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Gd3+ and Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Y3+ synthesized R-LED device has extremely high color rendering index, Ra is 78.23/77.15 and color temperature is 1640.38 K/1642.97 K. The experimental results show that the Lu2.34Sc2Ga3O12: 0.2Eu3+, 0.02Gd3+ / Y3+ phosphors prepared has a wide application prospect in w-LED devices.
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Connected and automated vehicles (CAVs) hold promise for enhancing transportation safety and efficiency. However, their large-scale deployment necessitates rigorous testing across diverse driving scenarios to ensure safety performance. In order to address two challenges of test scenario diversity and comprehensive evaluation, this study proposes a vehicle lane-changing scenario generation method based on a time-series generative adversarial network (TimeGAN) with an adaptive parameter optimization strategy (APOS). With just 13.3% of parameter combinations tested, we successfully trained a satisfactory TimeGAN and generate a substantial number of lane-changing scenarios. Then, the generated scenarios were evaluated for diversity, fidelity, and utility, demonstrating their effectiveness in capturing a wide range of driving situations. Furthermore, we employed a Lane-Changing Risk Index (LCRI) to identify the rare adversarial cases in scenarios. Compared to real scenarios, our approach generates 27 times more adversarial cases with 1.8 times higher average risk, highlighting its potential for uncovering critical safety vulnerabilities. This study paves the way for more comprehensive and effective CAV testing, ultimately contributing to safer and more reliable autonomous driving technologies.
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Accidentes de Tránsito , Conducción de Automóvil , Humanos , Accidentes de Tránsito/prevención & control , Automóviles , Automatización , Seguridad , Redes Neurales de la ComputaciónRESUMEN
DNA-encoded library (DEL) technologies enable the fast exploration of gigantic chemical space to identify ligands for the target protein of interest and have become a powerful hit finding tool for drug discovery projects. However, amenable DEL chemistry is restricted to a handful of reactions, limiting the creativity of drug hunters. Here, we describe a new on-DNA synthetic pathway to access sulfides and sulfoximines. These moieties, usually contemplated as challenging to achieve through alkylation and oxidation, can now be leveraged in routine DEL selection campaigns.
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ADN , Sulfuros , ADN/química , Sulfuros/química , Sulfuros/síntesis química , Estructura Molecular , Iminas/química , Oxidación-Reducción , Alquilación , Descubrimiento de DrogasRESUMEN
Using a novel homologation-heterocyclization cascade, the on-DNA synthesis of benzofurans from aldehydes has been developed. The methodology, based on an innovative use of the Seyferth-Gilbert homologation, followed by a high yielding Sonogashira coupling in situ intramolecular cyclization one-pot, two-step reaction, provides a powerful and unique pathway for DNA-encoded library (DEL) synthesis of a wide array of pharmaceutically relevant benzofuran-based scaffolds.
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Benzofuranos , Biblioteca de Genes , Ciclización , ADNRESUMEN
LiYGeO4 phosphors doped with Dy3+ and Eu3+ ions were synthesized using the solid phase method, and their color characteristics were adjustable. The bandgap value of LiYGeO4 calculated by diffuse reflection data is very close to the theoretical value of 3.669 eV, indicating that LiYGeO4 is an ideal candidate for doped rare earth activated ions. The analysis of the emission spectra and fluorescence attenuation curves of Dy3+ and Eu3+ co-doped LiYGeO4 phosphors revealed a clear energy transfer process: energy transfer from Dy3+ to Eu3+. Analysis of emission spectra and fluorescence attenuation curves revealed a transfer of energy from Dy3+ to Eu3+. This transfer mechanism is attributed to the dipole-dipole interactions. In addition, by constantly adjusting the doping levels of Dy3+ and Eu3+, a warm white phosphor with a color temperature of 3881 K was obtained. Finally, the emission intensity of the LiYGeO4:0.015Dy3+,0.02Eu3+ phosphor at 423 K was 86%, indicating that the phosphor has excellent thermal stability and 40% internal quantum efficiency, which proves the potential application of the LiYGeO4 phosphor in white light-emitting diodes (w-LEDs).
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A series of Ca3Al2Ge3O12: xDy3+, yEu3+ phosphors were successfully prepared by the high-temperature solid-phase method. The phase and morphology of the phosphors were studied by means of Rietveld refinement and scanning electron microscopy. The results show that the phase is pure, and the crystal structure is the Ia3Ì d space group. In the Ca3Al2Ge3O12: xDy3+ phosphors, using 380 nm excitation, phosphors showed blue (4F9/2 â 6H15/2) and yellow (4F9/2 â 6H13/2) emission peaks at 481 and 581 nm, respectively. In Ca3Al2Ge3O12: xDy3+, yEu3+ phosphors, the energy transfer was inferred by the spectrum overlap of Dy3+ and Eu3+, and the lifetime attenuation was analyzed from the perspective of dynamics; finally, the band gap structure of the phosphors was analyzed by combining diffuse reflection spectra with the first principle, and the energy transfer mechanism and luminescence mechanism were elaborated by combining theory and practice. The transition from blue white light to red light can be achieved by tuning the range of y in Ca3Al2Ge3O12: 0.015Dy3+, yEu3+. Wherein, when y = 0.07, phosphors, the chromaticity coordinate of warm white CIE is (0.3932, 0.3203), the color temperature is 3093 K, and the warm white light is synthesized. The thermal stability of the synthesized warm white phosphors is 90.1% (423 K), the thermal sensing factors are Samax = 5.51 × 10-4 K-1 (303 K) and Srmax = 0.0359% K-1 (303 K), and the actual quantum efficiency is IQE = 52.48%. These results prove that Ca3Al2Ge3O12: Dy3+, Eu3+ have good application prospects as single-component warm w-LED devices.
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A novel on-DNA oxidative disulfide formation method has been developed. Under ambient conditions, the methodology showcased wide applicability and swift implementation in routine DNA-encoded library synthesis to access pharmaceutically relevant motifs.
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Thiophene and its substituted derivatives are a highly important class of heterocyclic compounds, with noteworthy applications in pharmaceutical ingredients. In this study, we leverage the unique reactivity of alkynes to generate thiophenes on-DNA, using a cascade iodination, Cadiot-Chodkiewicz coupling and heterocyclization. This approach, tackling on-DNA thiophene synthesis for the first time, generates diverse, and unprecedented structural and chemical features, which could be significant motifs in DEL screening as molecular recognition agents for drug discovery.
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Organophosphonic compounds are distinctive among natural products in terms of stability and mimicry. Numerous synthetic organophosphonic compounds, including pamidronic acid, fosmidromycin, and zoledronic acid, are approved drugs. DNA encoded library technology (DELT) is a well-established platform for identifying small molecule recognition to target protein of interest (POI). Therefore, it is imperative to create an efficient procedure for the on-DNA synthesis of α-hydroxy phosphonates for DEL builds.
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In this work, an environment-friendly core-shell material based on CDs@SiO2as the core and mesoporous ion-imprinted layer as the shell was reported. As a highly sensitive and accurate fluorescent sensor for the detection of Pb2+in environmental water, the composition combined ion imprinting technology with quantum dots to selectively quench the fluorescence of CDs by metal coordination in the presence of Pb2+, and the visual change of gradually weakening blue color could be observed by the naked eye for visual detection. The mesoporous structure significantly improved the detection recognition rate of CDs@SiO2@MIIPs.The molecularly imprinted sensor presented a favorable linear relationship over a Pb2+concentration range from 10 nmol l-1to 100 nmol l-1and a detection limit of 2.16 nmol l-1for Pb2+. The imprinting factor of the CDs@SiO2@MIIPs was 5.13. The sensor has a fast detection rate, is highly selective in the identification of Pb2+, and can be reused up to 10 times. The applicability of the method was evaluated by the determination of Pb2+in spiked environmental water samples with satisfactory results.
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ß-Lactam antibiotics are one of the most important antibacterial drug classes worldwide. This work will present the first prototype on-DNA ß-lactam combinatorial library with novel structures and chemical space properties that would be significant for phenotypic screening to identify the next generation of antibiotics to combat the pervasive problem of bacterial resistance.
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Antibacterianos , beta-Lactamas , Antibacterianos/farmacología , ADN , beta-Lactamas/farmacologíaRESUMEN
Antimony (Sb) demonstrates ascendant reactive activation with lithium ions thanks to its distinctive puckered layer structure. Compared with graphite, Sb can reach a considerable theoretical specific capacity of 660 mAh g-1 by constituting Li3Sb safer reaction potential. Hereupon, with a self-supported organic carbon as a three-dimensional polymer network structure, Sb/carbon (3DPNS-Sb/C) composites were produced through a hydrothermal reaction channel followed by a heat disposal operation. The unique structure shows uniformitarian Sb nanoparticles wrapped in a self-supported organic carbon, alleviating the volume extension of innermost Sb alloying, and conducive to the integrality of the construction. When used as anodes for lithium-ion batteries (LIBs), 3DPNS-Sb/C exhibits a high invertible specific capacity of 511.5 mAh g-1 at a current density of 0.5 A g-1 after 100 cycles and a remarkable rate property of 289.5 mAh g-1 at a current density of 10 A g-1. As anodes, LIBs demonstrate exceptional electrochemical performance.
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The reasonable design of the precursor of a carbon-based nanocatalyst is an important pathway to improve catalytic performance. In this study, a simple solvothermal method was used to synthesize [Cu(TPT)(2,5-tdc)] â 2H2 O (Cu-MOF), which contains N and S atoms, in one step. Further in-situ carbonization of the Cu-MOF as the precursor was used to synthesize Cu/Cux S-embedded N,S-doped porous carbon (Cu/Cux S/NSC) composites. The catalytic activities of the prepared Cu/Cux S/NSC were investigated through catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results show that the designed Cu/Cux S/NSC has exceptional catalytic activity and recycling stability, with a reaction rate constant of 0.0256â s-1 , and the conversion rate still exceeds 90 % after 15 cycles. Meanwhile, the efficient catalytic reduction of dyes (CR, MO, MB and RhB) confirmed its versatility. Finally, the active sites of the Cu/Cux S/NSC catalysts were analyzed, and a possible multicomponent synergistic catalytic mechanism was proposed.
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A novel composite HKUST-1/cellulose/chitosan aerogel (HKUST-1/CCSA) as an efficient adsorbent with hierarchical pores was prepared through a facile in situ growth way combining covalent cross-linking, vacuum freeze-drying, and solvothermal methods. By incorporating with cellulose (CE), covalently cross-linked cellulose (CE)/chitosan (CS) composite aerogel exhibits good stability, maintaining fine morphology and structures in acidic solutions under solvothermal conditions. Meantime, a high content of CS is beneficial to enhancing the growth of HKUST-1. Finally, the mass loading ratio of HKUST-1 is as high as 42.54 % in HKUST-1/CCSA. The BET specific surface area of HKUST-1/CCSA reaches 457.75 m2 g-1, which is much larger than that of CCSA (9.74 m2 g-1). HKUST-1/CCSA was applied to remove methylene blue with high adsorption capacity (526.3 mg g-1) and good recycling capability. This strategy can provide an effective and facile pathway to prepare ultra-stable polysaccharide-based composite aerogel with high specific surface area and hierarchical pores, branching out more applications in pollutant treatment fields.
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2D metal-organic framework (MOFs) can be ideal sacrificial templates for fabricating nanomaterials because of active sites exposed on the surface rather than in pores and channels, often exhibiting improved performance in catalysis applications. In this study, the novel 2D layered cobalt-based MOF [Co(TPT)(fma)(H2O)2]·3H2O (Co-MOF) has been constructed by the selection of high N atom content ligands. On this basis, a 2D nitrogen-doped carbon-coated cobalt nanoparticle composite (Co@NC) was prepared by using this MOF as a precursor. Magnetic Co@NC has excellent catalytic activity and recycling features regarding the reaction of 4-nitrophenol (4-NP) reducing to 4-aminophenol (4-AP) in the presence of NaBH4 at ambient temperature. 2D Co@NC-600 can reach nearly 100% conversion within 120 s and its stability remains almost unchanged after five reaction cycles. Moreover, this Co@NC catalyst also is highly active for catalytic reduction of dyes such as Rhodamine B (RhB) and Methylene blue (MB).
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Antibiotics as newly emerging organic pollutants are arousing more and more serious environmental issues. Meantime, metal-organic frameworks (MOFs) are considered as promising adsorbents to remove antibiotics. To overcome the limitations of large-scale applications for MOFs in the powder form, herein, we proposed a strategy of in-situ growth ZIF-67 onto polyaniline (PANI) modified regenerated cellulose aerogel (RCA). First, RCA was obtained by chemical cross-linking and physical cross-linking method. Then, PANI played the role of metal chelated layers, which were coated on RCA by in-situ polymerization. Finally, ZIF-67 nanocrystals were in-situ growth on the surface of the PANI coated regenerated cellulose aerogel to synthesise the composite adsorbent ZIF-67/PANI/RCA. The loading mass ratios of ZIF-67 on RCA and PANI/RCA were 25.39% and 42.38%, respectively, which indicates that PANI as interface layers can effectively promote the in-situ growth of ZIF-67 compared with pure RCA. The obtained composite adsorbent (ZIF-67/PANI/RCA) was applied for the adsorption of tetracycline (TC) with high adsorption capacity (409.55 mg·g-1) and good recycling ability. After six cycles of adsorption-desorption, the removal efficiency toward TC was still over 94%. This strategy may provide an effective and versatile pathway to increase MOF loading mass on aerogel and sequentially branch out their applications in pollutant treatment fields.
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Zeolitas , Compuestos de Anilina , Antibacterianos , Celulosa , Imidazoles , Esqueleto , TetraciclinaRESUMEN
Composites of MOFs and aerogels (MOFACs), as a new class of nanostructured materials, attract increasing attention due to their favorable adsorption properties. Herein, UiO-66-NH2-CS aerogel monolith (UNCAM) was synthesized by covalent crosslinking with hierarchical structure, exhibiting effective and stable adsorption of Pb(II) ions. The aerogel monolith containing 50% MOF particles possesses a ultra-low density of 15.8 mg·cm-3, which is mainly attributed to the highly porous structure. Meantime, UNCAM can be described more suitable by the pseudo-second-order model and shows a higher mass transfer rate. The highest Pb(II) adsorption capacity of aerogel monolith is up to 102.03 mg·g-1 (1.612 × 106 mg·m-3), which is comparable to literature reports. The adsorption of Pb(II) by UNCAM is an endothermic and spontaneous process and consistent with the Langmuir model, indicating that the adsorption process belongs to monolayer adsorption and chemisorption. Furthermore, the adsorption mechanisms of coordination interaction between N and Pb (II) were confirmed, and the O also played a synergistic role in adsorption on a certain degree. Lastly, The UNCAM retained 90.12% adsorption ability after three cycles. This strategy may provide an effective and versatile pathway to convert the bulk MOF particles into a shapeable form and sequentially branch out their applications in pollutant treatment fields.
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A pot experiment was conducted to study the effects of Eucalyptus grandis leaf litter during its early stage decomposition on the growth and the photosynthesis of Cichorium intybus. Each pot contained 12 kg soil mixed with different amounts of E. grandis leaf litter (30 g x pot(-1), A1; 60 g x pot(-1), A2; 90 g x pot(-1), A3; and 0 g x pot(-1), CK), and sowed with C. intybus. The growth indicators and the photosynthetic characteristics of C. intybus were measured after the third leaf of C. intybus seedlings fully expanded in treatment A3. At the early stage of leaf litter decomposition, the C. intybus biomass accumulation, leaf area growth, and synthesis of photosynthetic pigments were inhibited significantly, and the inhibition effect was getting stronger with the increasing amount of the leaf litter addition. The intercellular CO2 concentration of C. intybus was increased by litter addition, while the net photosynthetic rate, stomatal conductance, and transpiration rate were significantly lower than those of the control. With the increase of leaf litter addition, all the parameters of C. intybus light response and CO2 response except CO2 compensation point showed an obvious downward trend, and there existed significant differences between the treatments of litter additions and the control. It was suggested that during the decomposition of E. grandis leaf litter, its allelopathic substances released gradually and acted on receptor plants, inhibited the synthesis of photosynthetic pigments and the photosynthesis of the receptors, decreased the receptors environmental adaptation ability, and accordingly, inhibited the growth of C. intybus.
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Cichorium intybus/crecimiento & desarrollo , Eucalyptus/química , Feromonas/farmacología , Fotosíntesis/efectos de los fármacos , Hojas de la Planta/metabolismo , Cichorium intybus/fisiología , Feromonas/metabolismo , Fotosíntesis/fisiología , Plantones/crecimiento & desarrolloRESUMEN
Osteogenesis imperfecta (OI, also known as brittle bone disease) is caused mostly by mutations in two type I collagen genes, COL1A1 and COL1A2 encoding the pro-α1 (I) and pro-α2 (I) chains of type I collagen, respectively. Two Chinese families with autosomal dominant OI were identified and characterized. Linkage analysis revealed linkage of both families to COL1A2 on chromosome 7q21.3-q22.1. Mutational analysis was carried out using direct DNA sequence analysis. Two novel missense mutations, c.3350A>G and c.3305G>C, were identified in exon 49 of COL1A2 in the two families, respectively. The c.3305G>C mutation resulted in substitution of a glycine residue (G) by an alanine residue (A) at codon 1102 (p.G1102A), which was found to be mutated into serine (S), argine (R), aspartic acid (D), or valine (V) in other families. The c.3350A>G variant may be a de novo mutation resulting in p.Y1117C. Both mutations co-segregated with OI in respective families, and were not found in 100 normal controls. The G1102 and Y1117 residues were evolutionarily highly conserved from zebrafish to humans. Mutational analysis did not identify any mutation in the COX-2 gene (a modifier gene of OI). This study identifies two novel mutations p.G1102A and p.Y1117C that cause OI, significantly expands the spectrum of COL1A2 mutations causing OI, and has a significant implication in prenatal diagnosis of OI.
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Colágeno/genética , Mutación/genética , Osteogénesis Imperfecta/genética , Alelos , Secuencia de Aminoácidos , Pueblo Asiatico/genética , Niño , Colágeno/química , Colágeno Tipo I , Femenino , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Osteogénesis Imperfecta/diagnóstico por imagen , Linaje , Embarazo , Diagnóstico Prenatal , Radiografía , Adulto JovenRESUMEN
Neodymium-doped gadolinium gallium garnet (Nd:GGG)crystal is the best operation material of solid-state heat-capacity laser. In the present paper, Nd:GGG single crystal was grown by Czochralski (Cz) method. Fluorescence spectra and absorption spectra were measured. At the same time, the spectral parameters of Nd:GGG laser crystal were calculated by Judd-Ofelt theory, including absorption and emission cross-section, intensity parameters, radiative transition probability, fluorescence branch ratio and fluorescent lifetime. According to the measurement and calculation of absorption spectra, it is illustrated that the main absorption peak of Nd: GGG crystal was at near 808 nm, the absorption cross section of the main peak at 808 nm sigma abs, was equal to 4. 35 x 10(-20) cm2. The FWHM of absorption line-width was equal to 8 nm, and the absorption intensity became stronger with the increase in Nd3+ ions concentration. According to the measurement and calculation of fluorescence spectra, the fluorescence emission peak was at near 1062 nm, which corresponds to 4F(3/2) - 4(I(11/2) emission band of Nd3+ ions. The radiative transition probabilityof the main emission peak at 1062 nm A(jj') was equal to 1 832.01 s(-1). The fluorescence branch ratio betajj was equal to 45.07%. The fluorescence lifetime r was equal to 250 micros. The stimulated emission cross section sigma(lamda) was equal to 21.58 x 10(-20) cm2. The laser operationof 4F(3/2) - 4I(11/2) transition can be realized due to the larger fluorescence branch ratio and stimulated emission cross section