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1.
J Med Virol ; 96(5): e29640, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38699969

RESUMEN

After the termination of zero-COVID-19 policy, the populace in China has experienced both Omicron BA.5 and XBB waves. Considering the poor antibody responses and severe outcomes observed among the elderly following infection, we conducted a longitudinal investigation to examine the epidemiological characteristics and antibody kinetics among 107 boosted elderly participants following the Omicron BA.5 and XBB waves. We observed that 96 participants (89.7%) were infected with Omicron BA.5, while 59 (55.1%) participants were infected with Omicron XBB. Notably, 52 participants (48.6%) experienced dual infections of both Omicron BA.5 and XBB. The proportion of symptomatic cases appeared to decrease following the XBB wave (18.6%) compared to that after the BA.5 wave (59.3%). Omicron BA.5 breakthrough infection induced lower neutralizing antibody titers against XBB.1.5, BA.2.86, and JN.1, while reinfection with Omicron XBB broadened the antibody responses against all measured Omicron subvariants and may alleviate the wild type-vaccination induced immune imprinting. Boosted vaccination type and comorbidities were the significant factors associated with antibody responses. Updated vaccines based on emerging severe acute respiratory syndrome coronavirus 2 variants are needed to control the Coronavirus Disease 2019 pandemic in the elderly.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Inmunización Secundaria , SARS-CoV-2 , Humanos , Anciano , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19/administración & dosificación , Masculino , Femenino , Estudios Longitudinales , China/epidemiología , SARS-CoV-2/clasificación , SARS-CoV-2/fisiología , Anticuerpos Neutralizantes , Cinética , Anticuerpos Antivirales/sangre , Reinfección/epidemiología
2.
J Org Chem ; 89(6): 4067-4073, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38391391

RESUMEN

We describe herein an N-heterocyclic-carbene-catalyzed atroposelective synthesis of axially chiral diaryl ethers. Through a sequentially enantioselective desymmetric process and a kinetic resolution process, the products could be constructed in good yields with excellent enantiopurities. Both alcohols and phenols were compatible with this catalytic system. The axially chiral carboxylic acids derived from the esters were proven to be potential chiral ligands for asymmetric synthesis, for example, Rh(III)-catalyzed enantioselective C-H functionalization.

3.
J Org Chem ; 89(7): 4904-4915, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38500413

RESUMEN

The palladium-catalyzed highly regioselective asymmetric allylic alkylation of 3'-indolyl-3-oxindole derivatives with Morita-Baylis-Hillman (MBH) carbonates was developed to facilely construct chiral 3,3'-bisindole derivatives under mild reaction conditions. The regioselectivity (α/γ) of MBH carbonates was efficiently switched in the presence of chiral oxalamide phosphine or spiroketal-based diphosphine/Pd(0) complexes as a chiral catalyst. A series of multifunctional 3,3'-bisindole derivatives with all-carbon quaternary stereogenic centers were obtained in high yields with good to excellent enantio-, diastereo-, and regioselectivity. The present process is endowed with some salient features such as broad substrate scope, N-protecting group-free, excellent stereoselectivity, as well as adjustable regioselectivity.

4.
Inorg Chem ; 63(4): 2224-2233, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38214448

RESUMEN

Bifunctional materials have attracted ongoing interest in the field of detection and removal of contaminants because of their integration of two functions, but they exhibit commonly exceptional performance in only one of these two aspects. The interaction between the two functional units of the bifunctional materials may compromise their sensing and adsorption abilities. Guided by the concept of domain building blocks (DBBs), a hierarchical metal-organic framework (MOF)-on-MOF hybrid was designed by growing gold nanoclusters (AuNCs)-embedded zeolitic imidazolate framework 8 (AuNCs/ZIF-8) on the surface of Zr-MOF (UiO-66-NH2) for the simultaneous detection and removal of Hg2+. In the hybrid, the amino groups (-NH2) and AuNCs─which were the adsorption groups and sensing units, respectively, were isolated from each other. Specifically, the adsorption groups (-NH2) were assembled in the inner UiO-66-NH2 layer, while the sensing units (AuNCs) were confined in the outer ZIF-8 layer. This hierarchical structure not only spatially hindered the electron transfer between these two units but also triggered the aggregation-induced emission of AuNCs because of the confinement of ZIF-8 on the AuNCs, thus changing the fluorescence of AuNCs from quenching to enhancement. The newly prepared UiO-66-NH2@AuNCs/ZIF-8 hybrid, as expected, showed an ultralow detection limit (0.42 ppb) and a high adsorption capacity (129.9 mg·g-1) for Hg2+. Overall, this work provides a feasible approach to improve the integrated performance of MOF-based composites based on DBBs.

5.
Alcohol Alcohol ; 59(4)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38851209

RESUMEN

AIMS: High-intensity drinking (HID), extreme drinking considerably above the level of heavy episodic drinking (HED), is associated with long-term health and social consequences. There is limited understanding of HID beyond young adulthood. This study aims to identify concurrent risk factors for HID, comparing age differences among all adults. METHODS: Multinomial logistic and linear regression modeling was performed using a nationally-representative sample of adults (analytic n = 7956) from the 2015 and 2020 National Alcohol Surveys. The outcomes were any HID of 8-11 drinks and 12+ drinks for men, and 8+ drinks for women, and corresponding frequencies. Concurrent risk factors included coping motive, sensation seeking, simultaneous use of alcohol and cannabis (SAC), and drinking at a bar or party. Analyses were stratified by age (18-29 vs. older) and sex. RESULTS: For younger men, sensation-seeking was significantly associated with HID (vs. no HED) at both levels and frequency of HID 8-11 drinks, while drinking to cope was only significant for 12+ drinks. For older men, drinking to cope was a consistent predictor for both HID level and its frequency, but sensation-seeking was not significant. Both coping and sensation-seeking were significantly associated with any HID for all women, while coping was significant for HID frequency for younger women. Frequent drinking at bars and parties were associated with greater odds of HID for all adults. With HED as referent, similar patterns of (though fewer significant) associations were observed. CONCLUSIONS: Younger and older adults share similar risk factors for HID, with coping more consistent for older men.


Asunto(s)
Adaptación Psicológica , Motivación , Humanos , Masculino , Femenino , Adulto , Adulto Joven , Estados Unidos/epidemiología , Adolescente , Consumo de Bebidas Alcohólicas/epidemiología , Consumo de Bebidas Alcohólicas/psicología , Factores de Riesgo , Uso de la Marihuana/epidemiología , Uso de la Marihuana/psicología , Persona de Mediana Edad , Factores de Edad , Consumo Excesivo de Bebidas Alcohólicas/epidemiología , Consumo Excesivo de Bebidas Alcohólicas/psicología , Factores Sexuales
6.
Artículo en Inglés | MEDLINE | ID: mdl-38880996

RESUMEN

Ethnic enclave residence is associated with decreased risk for drinking and related problems, but less is known about the mechanisms that explain this association. Informed by theories of social control, we used a multilevel framework to examine whether negative attitudes toward drinking mediated associations between ethnic enclave residence (i.e., neighborhood linguistic isolation) and alcohol outcomes among Mexican American young adults (N = 628) in Southern California. Model 1 assessed mediation effects in the pathways from linguistic isolation to current drinking and alcohol use disorder (AUD). Model 2 adjusted for parental drinking attitudes and neighborhood alcohol availability. There were differential associations by gender in direct effects of linguistic isolation and negative drinking attitudes on both drinking and AUD. Among women only, linguistic isolation was related to greater abstinence and decreased AUD after accounting for social control proxies of parent attitudes and alcohol availability. Young adults' own drinking attitudes did not mediate relationships between linguistic isolation and alcohol outcomes. This study offers evidence on the importance of disaggregating Hispanic national groups by gender to uncover social mechanisms within ethnic enclave settings for tailored supports in reducing risk of drinking and alcohol-related harms.

7.
Angew Chem Int Ed Engl ; : e202404728, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38760998

RESUMEN

Lithium-ion batteries play an integral role in various aspects of daily life, yet there is a pressing need to enhance their safety and cycling stability. In this study, we have successfully developed a highly secure and flexible solid-state polymer electrolyte (SPE) through the in situ polymerization of allyl acetoacetate (AAA) monomers. This SPE constructed an efficient Li+ transport channel inside and effectively improved the solid-solid interface contact of solid-state batteries to reduce interfacial impedance. Furthermore, it exhibited excellent thermal stability, an ionic conductivity of 3.82×10-4 S cm-1 at room temperature (RT), and a Li+ transport number (tLi+) of 0.66. The numerous oxygen vacancies on layered inorganic SiO2 created an excellent environment for TFSI- immobilization. Free Li+ migrated rapidly at the C=O equivalence site with the poly(allyl acetoacetate) (PAAA) matrix. Consequently, when cycled at 0.5C and RT, it displayed an initial discharge specific capacity of 140.6 mAh g-1 with a discharge specific capacity retention rate of 70 % even after 500 cycles. Similarly, when cycled at a higher rate of 5C, it demonstrated an initial discharge specific capacity of 132.3 mAh g-1 while maintaining excellent cycling stability.

8.
J Am Chem Soc ; 145(36): 19707-19714, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37578936

RESUMEN

The susceptibility to moisture of metal-organic frameworks (MOFs) is a critical bottleneck for their wider practical application. Constructing core-shell composites has been postulated as an effective strategy for enhancing moisture resistance, but for fragile MOFs this has rarely been accomplished. We report herein, for the first time, the construction of a customized hydrophobic porous shell, NTU-COF, on the particularly fragile MOF-5 by a "Plug-Socket Anchoring" strategy. Notably, the pore structure of MOF-5 was well maintained, and it could still achieve complete CO2/N2 separation under humid conditions. The homogeneous interface between MOF-5 and NTU-COF has been inspected at atomic resolution by a combination of cryogenic focused ion beam (cryo-FIB) and ultralow-dose (scanning) transmission electron microscope giving profound insight into the mechanism of assembly of the core-shell structure. This work presents a facile strategy for the fabrication of a hydrophobic porous shell for labile MOFs, and provides a general approach for solving the problem of moisture instability of porous materials for practical applications.

9.
J Am Chem Soc ; 145(25): 13901-13911, 2023 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-37311069

RESUMEN

One-step harvest of high-purity light hydrocarbons without the desorption process represents an advanced and highly efficient strategy for the purification of target substances. The separation and purification of acetylene (C2H2) from carbon dioxide (CO2) by CO2-selective adsorbents are urgently demanded yet are very challenging owing to their similar physicochemical properties. Here, we employ the pore chemistry strategy to adjust the pore environment by immobilizing polar groups into an ultramicroporous metal-organic framework (MOF), achieving one-step manufacture of high-purity C2H2 from CO2/C2H2 mixtures. Embedding methyl groups into prototype stable MOF (Zn-ox-trz) not only changes the pore environment but also improves the discrimination of guest molecules. The methyl-functionalized Zn-ox-mtz thus exhibits the benchmark reverse CO2/C2H2 uptake ratio of 12.6 (123.32/9.79 cm3 cm-3) and an exceptionally high equimolar CO2/C2H2 selectivity of 1064.9 at ambient conditions. Molecular simulations reveal that the synergetic effect of pore confinement and surfaces decorated with methyl groups provides high recognition of CO2 molecules through multiple van der Waals interactions. The column breakthrough experiments suggest that Zn-ox-mtz dramatically achieved the one-step purification capacity of C2H2 from the CO2/C2H2 mixture with a record C2H2 productivity of 2091 mmol kg-1, surpassing all of the CO2-selective adsorbents reported so far. In addition, Zn-ox-mtz exhibits excellent chemical stability under different pH values of aqueous solutions (pH = 1-12). Moreover, the highly stable framework and excellent inverse selective CO2/C2H2 separation performance showcase its promising application as a C2H2 splitter for industrial manufacture. This work paves the way to developing reverse-selective adsorbents for the challenging gas separation process.

10.
Small ; 19(39): e2301572, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37236175

RESUMEN

Solid-state lithium-ion batteries (SLIBs) are the promising development direction for future power sources because of their high energy density and reliable safety. To optimize the ionic conductivity at room temperature (RT) and charge/discharge performance to obtain reusable polymer electrolytes (PEs), polyvinylidene fluoride (PVDF), and poly(vinylidene fluoride-hexafluoro propylene) (P(VDF-HFP)) copolymer combined with polymerized methyl methacrylate (MMA) monomers are used as substrates to prepare PE (LiTFSI/OMMT/PVDF/P(VDF-HFP)/PMMA [LOPPM]). LOPPM has interconnected lithium-ion 3D network channels. The organic-modified montmorillonite (OMMT) is rich in the Lewis acid centers, which promoted lithium salt dissociation. LOPPM PE possessed high ionic conductivity of 1.1 × 10-3 S cm-1 and a lithium-ion transference number of 0.54. The capacity retention of the battery remained 100% after 100 cycles at RT and 0.5 C. The initial capacity of one with the second-recycled LOPPM PE is 123.9 mAh g-1 . This work offered a feasible pathway for developing high-performance and reusable LIBs.

11.
Inorg Chem ; 62(7): 3123-3133, 2023 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-36749708

RESUMEN

The development of multifunctional materials for the synchronous detection and removal of mercury ions (Hg2+) is in high demand. Although a few multifunctional materials as a fluorescent indicator and adsorbent have achieved this aim, the feedback of their removal efficiency still depends on other methods. Herein, magnetic Fe3O4 nanoparticles (MNPs) and 6-aza-2-thiothymine-protected gold nanoclusters (ATT-AuNCs) were rationally assembled into a zeolitic imidazolate framework 8 (ZIF-8) structure via a one-pot method. The coordination assembly of ATT-AuNCs and ZIF-8 not only strengthened the aurophilic interactions of adjacent ATT-AuNCs but also induced the restriction of intramolecular motion of ATT with a six-membered heterocyclic structure. As a consequence, the fluorescence (FL) quantum yield of MNPs/ATT-AuNCs@ZIF-8 was 12.5-fold higher than that of pristine ATT-AuNCs. Benefiting from the enhanced FL emission, MNPs/ATT-AuNCs@ZIF-8 showed improved sensitivity for Hg2+ detection and therefore could evaluate the removal efficiency via FL detection, without relying on another detection method. Additionally, the nanocomposite also displayed a satisfactory removal capability for Hg2+, including a short capture time (20 min), a high removal efficiency (>96.9%), and excellent reusability (10 cycles). This work provides an approach for customizing functional nanocomposites to concurrently detect and remove Hg2+ with superior performance, especially for high detection sensitivity.

12.
Phys Chem Chem Phys ; 25(41): 28078-28085, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37622227

RESUMEN

Solvent-controlled extraction and precipitation are the most fundamental methods for obtaining hemicellulose from lignocellulosic biomass and purification processes. However, the dissolution and precipitation mechanisms involved have scarcely been mentioned. In this study, the molecular scale behavior of xylan-type hemicellulose during solvent-controlled extraction and precipitation is investigated using molecular dynamics (MD) simulations and density functional theory (DFT) calculations. To bring the model closer to the real extracted xylan, a high degree of polymerization (DP100) of xylan is established, and hemicelluloses with low DP (DP15 and DP50) are also investigated. Four phenomena are explained at the molecular level, including the influence of the polymerization degree and side chain on the solubility of xylan in water, the improvement of the xylan's solubility in NaOH, the precipitation of xylan in ethanol, and the acetyl group preservation of xylan in DMSO. This study contributes to an increased understanding of the dissolution and precipitation mechanisms of hemicellulose and provides a resource for the simulation of high DP hemicellulose, which gives a theoretical basis for the efficient extraction of high-purity hemicellulose as well as economic biorefining.

13.
Alcohol Alcohol ; 58(5): 523-531, 2023 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-37258041

RESUMEN

Co-use of multiple drugs may prolong or increase heavy drinking, even for individuals with health conditions adversely affected by it. Patterns of alcohol and drug use may vary across racial/ethnic groups, with differential implications for health. This study examines racial/ethnic differences in the associations between risky drinking and other drug use in adults with diabetes, hypertension, heart disease, or cancer. Multiple logistic regression modeling, stratified by condition, was performed using a nationally representative sample of adults drawn from the 2015 to 2019 National Survey on Drug and Health. The outcome was risky drinking (consuming more than 7/14 drinks weekly). Other drugs considered were tobacco, marijuana, illicit drugs, and non-medical prescription drugs. Covariates included age, sex, education, income, marital/cohabitation status, health insurance coverage, and self-rated health status. Each drug category was positively associated with risky drinking across all four conditions. Racial/ethnic minority adults were less likely than White adults to engage in risky drinking, with this pattern most consistent for those with hypertension. Other drug use in minority adults (i.e. tobacco and illicit drug use in Black and Hispanic adults, and marijuana and prescription drug use in Asian adults) was associated with disproportionately greater odds of risky drinking compared with White adults. This pattern was more prominent for those with a heart condition, and not found for those with cancer. Future interventions might address co-use of alcohol and other drugs in adults with chronic conditions, with special attention to racial/ethnic minority adults.


Asunto(s)
Enfermedad Crónica , Trastornos Relacionados con Sustancias , Adulto , Humanos , Enfermedad Crónica/epidemiología , Enfermedad Crónica/etnología , Etanol , Etnicidad , Hispánicos o Latinos , Grupos Minoritarios , Trastornos Relacionados con Sustancias/epidemiología , Trastornos Relacionados con Sustancias/etnología , Estados Unidos/epidemiología , Blanco , Negro o Afroamericano , Asiático , Grupos Raciales/estadística & datos numéricos
14.
Appl Opt ; 62(3): 725-734, 2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36821278

RESUMEN

Optomechanical components such as the lens barrels and frames of IR spectrometers produce strong internal stray radiation, which reduces the instrument's SNR and dynamic range. An IR internal stray radiation calculation method based on an analytical model of the view factor is proposed. The mathematical model of the view factor calculation method of typical optomechanical components is established. For any IR optical systems, the internal stray radiation can be quickly and accurately calculated by adjusting the coordinate systems in the calculation method. Based on the proposed method, the internal stray radiation of a double-pass long-wave IR spectrometer was calculated. The calculation results are consistent with the simulation results. The RMS value of the relative error between the calculated value and the simulated value is around 11%. To verify the proposed method, an experiment was conducted to test the internal stray radiation of the long-wave IR spectrometer. The internal stray radiation test results agree with the calculated and simulated results, and the relative error between the test results and the calculation results is within 9%.

15.
Luminescence ; 2023 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-38148625

RESUMEN

It is of great significance to develop an effective method for methyl parathion (MP) detection. Herein, a novel nitrogen-doped titanium carbide quantum dots (N-Ti3 C2 QDs) was prepared and used to construct a simple and sensitive fluorescence sensing platform of MP by making use of inner filter effect (IFE). The prepared N-Ti3 C2 QDs can exhibit strong blue fluorescence at 434 nm. Meanwhile, MP could hydrolyze to produce p-nitrophenol (p-NP) under alkaline conditions, which showed a characteristic ultraviolet-visible (UV-visible) absorption peak at 405 nm, resulting in the fluorescence of N-Ti3 C2 QDs is effectively quenched by p-NP. In addition, the investigation of time-resolved fluorescence decays indicated that the corresponding quenching mechanism of p-NP on N-Ti3 C2 QDs is due to the IFE. After optimizing the conditions, the as-developed fluorescence sensing platform displayed wide detection range (0.1-30 µg mL-1 ) and low detection limit (0.036 µg mL-1 ) for MP, and it was also successfully applied for MP analysis in real water samples, thus it is expected that this simple, sensitive and enzyme-free sensing platform shows great applications.

16.
Dev Dyn ; 251(7): 1175-1195, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35048440

RESUMEN

BACKGROUND: Hedgehog (HH) signaling is essential for homeostasis in gustatory fungiform papillae (FP) and taste buds. However, activities of HH antagonists in these tissues remain unexplored. We investigated a potential role for HH-interacting protein (HHIP), an endogenous pathway antagonist, in regulating HH signaling during taste organ homeostasis. We found a restricted pattern of Hhip-expressing cells in the anterior epithelium of each nongustatory filiform papilla (FILIF) only. To test for roles in antagonism of HH signaling, we investigated HHIP after pathway inhibition with SMO inhibition via sonidegib and Smo deletion, Gli2 deletion/suppression, or with chorda tympani/lingual nerve cut. RESULTS: In all approaches, the HHIP expression pattern was retained in FILIF suggesting HH-independent regulation of HHIP. Remarkably, after pathway inhibition, HHIP expression was detected also in the conical, FILIF-like atypical FP. We found a close association of de novo expression of HHIP in atypical FP with loss of Gli1+, HH-responding cells. Further, we report that PTCH1 is another potential HH antagonist in FILIF that co-localizes with HHIP. CONCLUSIONS: After HH pathway inhibition the ectopic expression of HHIP correlates with a FILIF-like morphology in atypical FP and we propose that localized expression of the HH antagonist HHIP regulates pathway inhibition to maintain FILIF during tongue homeostasis.


Asunto(s)
Papilas Gustativas , Expresión Génica Ectópica , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Homeostasis , Papilas Gustativas/metabolismo , Lengua
17.
Angew Chem Int Ed Engl ; 62(50): e202316149, 2023 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-37937327

RESUMEN

Porous materials with d3 electronic configuration open metal sites have been proved to be effective adsorbents for N2 capture and N2 /O2 separation. However, the reported materials remain challenging to address the trade-off between adsorption capacity and selectivity. Herein, we report a robust MOF, MIL-102Cr, that features two binding sites, can synergistically afford strong interactions for N2 capture. The synergistic adsorption site exhibits a benchmark Qst of 45.0 kJ mol-1 for N2 among the Cr-based MOFs, a record-high volumetric N2 uptake (31.38 cm3 cm-3 ), and highest N2 /O2 selectivity (13.11) at 298 K and 1.0 bar. Breakthrough experiments reveal that MIL-102Cr can efficiently capture N2 from a 79/21 N2 /O2 mixture, providing a record 99.99 % pure O2 productivity of 0.75 mmol g-1 . In situ infrared spectroscopy and computational modelling studies revealed that a synergistic adsorption effect by open Cr(III) and fluorine sites was accountable for the strong interactions between the MOF and N2 .

18.
Angew Chem Int Ed Engl ; 62(37): e202308579, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37486880

RESUMEN

Developing hydrogen-bonded organic frameworks (HOFs) that combine functional sites, size control, and storage capability for targeting gas molecule capture is a novel and challenging venture. However, there is a lack of effective strategies to tune the hydrogen-bonded network to achieve high-performance HOFs. Here, a series of HOFs termed as HOF-ZSTU-M (M=1, 2, and 3) with different pore structures are obtained by introducing structure-directing agents (SDAs) into the hydrogen-bonding network of tetrakis (4-carboxyphenyl) porphyrin (TCPP). These HOFs have distinct space configurations with pore channels ranging from discrete to continuous multi-dimensional. Single-crystal X-ray diffraction (SCXRD) analysis reveals a rare diversity of hydrogen-bonding models dominated by SDAs. HOF-ZSTU-2, which forms a strong layered hydrogen-bonding network with ammonium (NH4 + ) through multiple carboxyl groups, has a suitable 1D "pearl-chain" channel for the selective capture of propylene (C3 H6 ). At 298 K and 1 bar, the C3 H6 storage density of HOF-ZSTU-2 reaches 0.6 kg L-1 , representing one of the best C3 H6 storage materials, while offering a propylene/propane (C3 H6 /C3 H8 ) selectivity of 12.2. Theoretical calculations and in situ SCXRD provide a detailed analysis of the binding strength of C3 H6 at different locations in the pearl-chain channel. Dynamic breakthrough tests confirm that HOF-ZSTU-2 can effectively separate C3 H6 from multi-mixtures.

19.
Angew Chem Int Ed Engl ; 62(37): e202309095, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37488075

RESUMEN

Polycrystalline metal-organic framework (MOF) layers hold great promise as molecular sieve membranes for efficient gas separation. Nevertheless, the high crystallinity tends to cause inter-crystalline defects/cracks in the nearby crystals, which makes crystalline porous materials face a great challenge in the fabrication of defect-free membranes. Herein, for the first time, we demonstrate the balance between crystallinity and film formation of MOF membrane through a facile in situ modulation strategy. Monocarboxylic acid was introduced as a modulator to regulate the crystallinity via competitive complexation and thus concomitantly control the film-forming state during membrane growth. Through adjusting the ratio of modulator acid/linker acid, an appropriate balance between this structural "trade-off" was achieved. The resulting MOF membrane with moderate crystallinity and coherent morphology exhibits molecular sieving for H2 /CO2 separation with selectivity up to 82.5.

20.
Angew Chem Int Ed Engl ; 62(40): e202309918, 2023 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-37583031

RESUMEN

Protein channels on the biofilm conditionally manipulate ion transport via regulating the distribution of charge residues, making analogous processes on artificial membranes a hot spot and challenge. Here, we employ metal-organic frameworks (MOFs) membrane with charge-adjustable subnano-channel to selectively govern ion transport. Various valent ions are binded with crown ethers embedded in the MOF cavity, which act as charged guest to regulate the channels' charge state from the negativity to positivity. Compared with the negatively charged channel, the positive counterpart obviously enhances Li+ /Mg2+ selectivity, which benefit from the reinforcement of the electrostatic repulsion between ions and the channel. Meanwhile, theoretical calculations reveal that Mg2+ transport through the more positively charged channel needed to overcome higher entrance energy barrier than that of Li+ . This work provides a subtle strategy for ion-selective transport upon regulating the charge state of insulating membrane, which paves the way for the application like seawater desalination and lithium extraction from salt lakes.

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