The selective adsorption/separation of C2 hydrocarbons has been realized in a “flexible-robust” MOF, Zn2(Atz)2Ox. Owing to the distinctive guest-dependent multistep adsorption behaviors and suitable ...guest–framework interactions, this MOF shows outstanding separation performance for C2H2/C2H4 mixtures in a wide range of temperature confirmed by a column breakthrough experiment.
Exploring novel multifunctional rare earth materials is very important because these materials have fundamental interests, such as new structural facts and connecting modes, as well as potential ...technological applications, including optics, magnetic properties, sorption, and catalytic behaviors. Especially, employing these nanomaterials for sensing or catalytic reactions is still very challenging. Herein, a new superstable, anionic terbium‐metal–organic‐framework, H2N(CH3)2Tb(cppa)2(H2O)2, (China Three Gorges University (CTGU‐1), H2cppa = 5‐(4‐carboxyphenyl)picolinic acid), is successfully prepared, which can be used as a turn‐on, highly‐sensitive fluorescent sensor to detect Eu3+ and Dy3+, with a detection limitation of 5 × 10−8 and 1 × 10−4m in dimethylformamide, respectively. This result represents the first example of lanthanide‐metal–organic‐frameworks (Ln‐MOF) that can be employed as a discriminative fluorescent probe to recognize Eu3+ and Dy3+. In addition, through ion exchanging at room temperature, Ag(I) can be readily reduced in situ and embedded in the anionic framework, which leads to the formation of nanometal‐particle@Ln‐MOF composite with uniform size and distribution. The as‐prepared Ag@CTGU‐1 shows remarkable catalytic performance to reduce 4‐nitrophenol, with a reduction rate constant κ as large as 2.57 × 10−2 s−1; almost the highest value among all reported noble‐metal‐nanoparticle@MOF composites.
A new porous, anionic Tb‐metal–organic‐framework, China Three Gorges University (CTGU‐1), can serve as a turn‐on sensor for detection of Eu3+ and Dy3+, with different detection limits. Additionally, spontaneous in situ reduction and immobilization of ion‐exchanged Ag(I) to Ag nanoparticles in the anionic framework result in an Ag@CTGU‐1 composite, which can remarkably catalyze the reduction of 4‐nitrophenol.
Stomatal closure is regulated by plant hormones and some small molecules to reduce water loss under stress conditions. Both abscisic acid (ABA) and polyamines alone induce stomatal closure; however, ...whether the physiological functions of ABA and polyamines are synergistic or antagonistic with respect to inducing stomatal closure is still unknown. Here, stomatal movement in response to ABA and/or polyamines was tested in Vicia faba and Arabidopsis thaliana, and the change in the signaling components under stomatal closure was analyzed. We found that both polyamines and ABA could induce stomatal closure through similar signaling components, including the synthesis of hydrogen peroxide (H2O2) and nitric oxide (NO) and the accumulation of Ca2+. However, polyamines partially inhibited ABA‐induced stomatal closure both in epidermal peels and in planta by activating antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), to eliminate the ABA‐induced increase in H2O2. These results strongly indicate that polyamines inhibit abscisic acid‐induced stomatal closure, suggesting that polyamines could be used as potential plant growth regulators to increase photosynthesis under mild drought stress.
The development of ethane (C2H6)‐selective adsorbents for ethylene (C2H4) purification, although challenging, is of prime industrial importance. Pillared‐layer metal‐organic frameworks (MOFs) possess ...facilely tunable pore structure and functionality, which means they have excellent potential for high‐performance C2H6/C2H4 separation applications. Herein, we report a family of isostructural pillared‐layer MOFs with various metal centers M and co‐ligands L, M2(D‐cam)4L2 (denoted M‐cam‐L; M = Cu, Co, Ni; L = pyz, apyz, dabco), with a variety of pore surface properties. All of the M‐cam‐L materials exhibit preferential adsorption for C2H6 over C2H4. In particular, Ni‐cam‐pyz exhibits the highest C2H6 capture capacity (68.75 cm3 g−1 at 1 bar and 298 K), Cu‐cam‐dabco possesses the greatest C2H6/C2H4 adsorption selectivity (2.3), and the lowest isosteric heat of adsorption is demonstrated for Cu‐cam‐pyz (20.1 kJ mol−1). Dynamic column breakthrough experiments also confirmed the excellent separation performance of M‐cam‐pyz and M‐cam‐dabco materials. The synthesis route of the M‐cam‐L materials is easily scaled‐up under laboratory conditions, and hence this class of MOFs is promising for practical C2H4 purification.
In this work, Fe3O4 and metal–organic framework MIL-101(Fe) composites (Fe3O4/MIL-101(Fe)) was demonstrated to possess excellent catalytic property to directly catalyze luminol chemiluminescence ...without extra oxidants. We utilized Fe3O4/MIL-101(Fe) to develop a ultra-sensitive quantitative analytical method for H2O2 and glucose. The possible mechanism of the chemiluminescence reaction had been investigated. Under optimal conditions, the relative chemiluminescence intensity was linearly proportional to the logarithm of H2O2 concentration in the range of 5–150nM with a limit of detection of 3.7nM (signal-to-noise ratio = 3), and glucose could be linearly detected in the range from 5 to 100nM and the detection limit was 4.9nM (signal-to-noise ratio = 3). Furthermore, the present approach was successfully applied to quantitative determination of H2O2 in medical disinfectant and glucose in human serum samples.
Fe3O4/MIL-101(Fe) could catalyze luminol chemiluminescence without extra oxidants and the chemiluminescence intensity of Fe3O4/MIL-101(Fe)-luminol system could be further improved by H2O2 and glucose, which were used to fabricate a ultra-sensitive quantitative analytical method for H2O2 and glucose. Display omitted
•Fe3O4/MIL-101(Fe) possessed more outstanding catalytic performance than individual Fe3O4 or MIL-101(Fe).•The composites ould catalyze luminol chemiluminescence without extra oxidants.•The nanomole of H2O2 and glucose could be detected by Fe3O4/MIL-101(Fe)-luminol chemiluminescence system.
Designing efficient multifunctional electrocatalysts for water and urea splitting to produce green hydrogen presents a significant yet worthwhile challenge. Herein, the morphology and electronic ...structure of cobalt metaphosphate (Co2P4O12) by vanadium (V) doping, resulting in improved electrocatalytic activity and stability for hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR) are simultaneously regulated. Theory calculations show that V‐doped Co2P4O12 (V‐Co2P4O12) can boost the kinetics of catalytic reactions by optimizing the d‐band center of Co atoms and the binding strength of intermediates, as well as enhancing the density of states. Moreover, the doping of V into Co2P4O12 crystalline structure benefits the formation of a thicker amorphous layer during the catalytic process, which could enhance its alkaline corrosion resistance and stability. Additionally, the multilevel nanostructures of V‐Co2P4O12 provide rich active sites for catalytic reactions. As a result, a two‐electrode electrolyzer assembled by V‐doped Co2P4O12 delivers low voltages for overall water and urea splitting. The superior performance suggests that the proposed V‐doping strategy is a promising way to regulate electrocatalytic activity for catering to green electrocatalytic applications.
The morphology and electronic structure of the Co2P4O12 catalyst are simultaneously regulated by V doping, which endows the catalyst with enhanced hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and urea oxidation reaction (UOR) performance. Thanks to the excellent trifunctional catalytic performance, the assembled two‐electrode electrolyzers enable efficient overall water and urea splitting at low overpotentials.
Rationale
The
N
-methyl-
d
-aspartate (NMDA) receptor antagonists, including
R
-ketamine and rapastinel (formerly GLYX-13), show rapid antidepressant effects in animal models of depression.
Objective
...We compared the rapid and sustained antidepressant effects of
R
-ketamine and rapastinel in the social defeat stress model.
Results
In the tail suspension and forced swimming tests,
R
-ketamine (10 mg/kg, intraperitoneal (i.p.)) or rapastinel (10 mg/kg, i.p.) significantly attenuated the increased immobility time in the susceptible mice, compared with the vehicle-treated group. In the sucrose preference test, both compounds significantly enhanced the reduced preference in susceptible mice 2, 4, or 7 days after a single injection. All mice were sacrificed 8 days after a single injection. Western blot analyses showed that
R
-ketamine, but not rapastinel, significantly attenuated the reduced brain-derived neurotrophic factor (BDNF)-TrkB signaling, postsynaptic density protein 95 (PSD-95), and GluA1 (a subtype of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor) in the prefrontal cortex, dentate gyrus, and CA3 of the hippocampus in the susceptible mice. In contrast, both compounds had no effect against the increased BDNF-TrkB signaling, PSD-95, and GluA1 seen in the nucleus accumbens of susceptible mice. Moreover, sustained antidepressant effect of
R
-ketamine (3 mg/kg, intravenous (i.v.)), but not rapastinel (3 mg/kg, i.v.), was detected 7 days after a single dose.
Conclusions
These results highlight
R
-ketamine as a longer lasting antidepressant compared with rapastinel in social defeat stress model. It is likely that synaptogenesis including BDNF-TrkB signaling in the prefrontal cortex (PFC) and hippocampus may be required for the mechanisms promoting this sustained antidepressant effect.
In principle, porous physisorbents are attractive candidates for the removal of volatile organic compounds such as benzene by virtue of their low energy for the capture and release of this pollutant. ...Unfortunately, many physisorbents exhibit weak sorbate-sorbent interactions, resulting in poor selectivity and low uptake when volatile organic compounds are present at trace concentrations. Herein, we report that a family of double-walled metal-dipyrazolate frameworks, BUT-53 to BUT-58, exhibit benzene uptakes at 298 K of 2.47-3.28 mmol g
at <10 Pa. Breakthrough experiments revealed that BUT-55, a supramolecular isomer of the metal-organic framework Co(BDP) (H
BDP = 1,4-di(1H-pyrazol-4-yl)benzene), captures trace levels of benzene, producing an air stream with benzene content below acceptable limits. Furthermore, BUT-55 can be regenerated with mild heating. Insight into the performance of BUT-55 comes from the crystal structure of the benzene-loaded phase (C
H
@BUT-55) and density functional theory calculations, which reveal that C-H···X interactions drive the tight binding of benzene. Our results demonstrate that BUT-55 is a recyclable physisorbent that exhibits high affinity and adsorption capacity towards benzene, making it a candidate for environmental remediation of benzene-contaminated gas mixtures.
Abstract The purpose of this study was to develop and validate a physiologically based pharmacokinetic (PBPK) model combined with an EGFR occupancy (EO) model for osimertinib (OSI) to predict plasma ...trough concentration (C trough ) and the intracranial time-course of EGFR (T790M and L858R mutants) engagement in patient populations. The PBPK model was also used to investigate the key factors affecting OSI pharmacokinetics (PK) and intracranial EGFR engagement, analyze resistance to the target mutation C797S, and determine optimal dosing regimens when used alone and in drug-drug interactions (DDIs). A population PBPK-EO model of OSI was developed using physicochemical, biochemical, binding kinetic, and physiological properties, and then validated using nine clinical PK studies, observed EO study, and two clinical DDI studies. The PBPK-EO model demonstrated good consistency with observed data, with most prediction-to-observation ratios falling within the range of 0.7 to 1.3 for plasma AUC, C max , C trough and intracranial free concentration. The simulated time-course of C797S occupancy by the PBPK model was much lower than T790M and L858R occupancy, providing an explanation for OSI on-target resistance to the C797S mutation. The PBPK model identified ABCB1 CL int,u , albumin level, and EGFR expression as key factors affecting plasma C trough and intracranial EO for OSI. Additionally, PBPK-EO simulations indicated that the optimal dosing regimen for OSI in patients with brain metastases is either 80 mg once daily (OD) or 160 mg OD, or 40 mg or 80 mg twice daily (BID). When used concomitantly with CYP enzyme perpetrators, the PBPK-EO model suggested appropriate dosing regimens of 80 mg OD with fluvoxamine (FLUV) itraconazole (ITR) or fluvoxamine (FLUC) for co-administration and an increase to 160 mg OD with rifampicin (RIF) or efavirenz (EFA). In conclusion, the PBPK-EO model has been shown to be capable of simulating the pharmacokinetic concentration–time profiles and the time-course of EGFR engagement for OSI, as well as determining the optimum dosing in various clinical situations.
Accurate evaluation of excess pore water pressure (EPWP) generated in earthquake vibration is a key important factor in seismic engineering against liquefaction. Most previous studies were focused on ...the relation between cyclic resistance and EPWP developed in the entire liquefaction process. Only a few researchers pointed out that the maximum EPWP ratio accumulated at the first loading cycle, represented by (Δu/p0)max−N1, was intimately related to the liquefaction resistance of sand. Based on this viewpoint, liquefaction resistance of sandy soils can be improved significantly by repressing EPWP at the first cycle by engineering countermeasures. The relationship between (Δu/p0)max−N1 and liquefaction resistance or the cyclic number to liquefaction Nf, however, has not been established quantitatively yet. Moreover, whether this relationship is influenced by stress states such as liquefaction-induced anisotropy, structure or fabric of soils, and loading conditions, is not clear yet. Therefore, a series of undrained cyclic triaxial loading tests were conducted on Toyoura sand, a clean sand famous in Japan, to identify the above-mentioned uncertainties. Based on the test results, a unique empirical (Δu/p0)max−N1-Nf relation was proposed to evaluate the liquefaction resistance. Finally, three typical samples were given to display the application of (Δu/p0)max−N1-Nf relation.
•The effect of the pore water pressure accumulated at the first cycle on liquefaction resistance were studied systematically.•A unique relation was proposed to predict liquefaction resistance by the accumulated pore water pressure at the first cycle.•Three engineering applications were employed to illustrate the application of the research finding.
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