Carbonic anhydrase (CA) is a zinc-containing metalloprotein, in which the Zn active center plays the key role to transform CO into carbonate. Inspired by nature, herein we used metal-organic frameworks (MOFs) to mimic CA for CO conversion, on the basis of the structural similarity between the Zn coordination in MOFs and CA active center. The biomimetic activity of MOFs was investigated by detecting the hydrolysis of para-nitrophenyl acetate, which is a model reaction used to evaluate CA activity. The biomimetic materials (e.g., CFA-1) showed good catalytic activity, and excellent reusability, and solvent and thermal stability, which is very important for practical applications. In addition, ZIF-100 and CFA-1 were used to mimic CA to convert CO gas, and exhibited good efficiency on CO conversion compared with those of other porous materials (e.g., MCM-41, active carbon). This biomimetic study revealed a novel CO treatment method. Instead of simply using MOFs to absorb CO, ZIF-100 and CFA-1 were used to mimic CA for in situ CO conversion, which provides a new prospect in the biological and industrial applications of MOFs.
Highly efficient removal of trace propyne (C3H4) (propyne <1000 ppm) from propylene (C3H6) is an essential and challenging industrial process due to the high molecular similarity of C3H4 and C3H6.
Selective separation of propyne/propadiene mixture to obtain pure propadiene (allene), an essential feedstock for organic synthesis, remains an unsolved challenge in the petrochemical industry, thanks mainly to their similar physicochemical properties. We herein introduce a convenient and energy-efficient physisorptive approach to achieve propyne/propadiene separation using microporous metal-organic frameworks (MOFs). Specifically, HKUST-1, one of the most widely studied high surface area MOFs that is available commercially, is found to exhibit benchmark performance (propadiene production up to 69.6 cm3/g, purity > 99.5%) as verified by dynamic breakthrough experiments. Experimental and modeling studies provide insight into the performance of HKUST-1 and indicate that it can be attributed to a synergy between thermodynamics and kinetics that arises from abundant open metal sites and cage-based molecular traps in HKUST-1.
Integrating photocatalysis and biocatalysis
to fabricate photobiocatalysts
for asymmetric catalysis is of great significance but remains challenging.
In this work, we build a photoenzymatic platform for asymmetric catalysis
using rationally designed photocatalytic porphyrinic covalent organic
frameworks (COFs) as mesoporous solid carriers to immobilize wheat
germ lipase (WGL). The formed WGL@COFs photobiocatalysts show high
enzymatic activity and good operational stability. Attributed to the
proximity effect of photocatalysts and enzymes in one system, WGL@COFs
exhibit good performance and reusability for an enantioselective Mannich
reaction under visible light irradiation. Notably, this asymmetric
reaction with the formation of C(sp3)–C(sp3) bonds cannot be achieved by WGL or COFs independently. Furthermore,
various characterization techniques unveil the catalytic mechanism
(singlet oxygen as the main pathway of asymmetric catalysis). This
work creates a general and efficient strategy using COFs as photocatalytic
platforms for enzyme immobilization to fabricate photobiocatalysts
that realize highly efficient photoenzymatic asymmetric catalysis.
Highly efficient
and selective removal of pharmaceuticals and personal care products
(PPCPs) from wastewater is a great challenge and is significant. In
this study, we chose UiO-66-R, which contains eight isostructural
metal–organic frameworks (MOFs) with variable functional groups
(−R), as a platform for systemically investigating the influence
of functionalization on its adsorption behavior with respect to three
classic PPCPs. We conducted kinetic, modeling, and structure–function
relationship studies on PPCP removal using MOFs. The adsorption kinetics,
including the adsorption rate, affinity, and separation factor (R
L), were comprehensively analyzed and simulated.
The design and function of MOFs can greatly promote their adsorption
capacity and the efficiency of PPCPs. The structure–function
relationship study revealed that hydrogen bonding, electrostatic,
and π–π interactions between MOFs and PPCP molecules
played important roles in the adsorption process and significantly
influenced the adsorption efficiency. This study paves a new way for
the application of MOFs with respect to the removal of PPCP pollution
and provides guidance for the design of new porous materials for environmental
treatment and separation applications.
In the past few years, a growing body of clinical evidence has highlighted the risk of vitamin D deficiency in patients with chronic hepatitis C and that vitamin D levels are associated with the course of hepatitis C virus (HCV) infection, adverse effects, and treatment response to peginterferon/ribavirin. Recently, studies have found that vitamin D status is related to drug resistance and increased risk of infection in patients with liver cirrhosis. Vitamin D-related gene polymorphisms have been found to explain the interactions between vitamin D deficiency and HCV infection, offering a new perspective toward understanding the current problems such as the development of insulin resistance and racial differences in sustained virological response. Studies have been conducted to determine whether vitamin D supplementation as an adjuvant yields a better result compared with traditional HCV treatment. Here, we provide a brief review of the past and present knowledge of vitamin D in HCV infection.
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