Construction of thermally and chemically robust metal−organic frameworks (MOFs) is highly desirable for postcombustion CO 2 capture from flue gas containing water vapor and other acidic gases. Here we report a strategy based on appending amino groups to the triazolate linkers of MOFs to achieve exceptional chemical stability against aqueous, acidic, and basic conditions. These MOFs exhibit not only CO 2 /N 2 thermodynamic adsorption selectivity as high as 120 but also CO 2 /H 2 O kinetic adsorption selectivity up to 70, featuring distinct adsorptive sites at the channel center for CO 2 and at the corner for H 2 O, respectively. The best performing MOF in this series features low regeneration energy, high CO 2 capture utility under humid conditions, and decent cycling performance for mimic flue gas.M etal−organic frameworks (MOFs) are prominent solid adsorbents that combine well-defined adsorptive sites, fine-tuned pore sizes, and decorated interior functionalities to achieve strong binding affinity, high selectivity, large capacity, and low regeneration energy for CO 2 capture. 1−3 However, with respect to practical postcombustion capture, concerns arise from the competitive adsorption of H 2 O against CO 2 4
The artificial engineering of an enzyme's structural conformation to enhance its activity is highly desired and challenging. Anisotropic reticular chemistry, best illustrated in the case of multivariate metal−organic frameworks (MTV-MOFs), provides a platform to modify a MOF's pore and inner-surface with functionality variations on frameworks to optimize the interior environment and to enhance the specifically targeted property. In this study, we altered the functionality and ratio of linkers in zeolitic imidazolate frameworks (ZIFs), a subclass of MOFs, with the MTV approach to demonstrate a strategy that allows us to optimize the activity of the encapsulated enzyme by continuously tuning the framework−enzyme interaction through the hydrophilicity change in the pores' microenvironment. To systematically study this interaction, we developed the component-adjustment-ternary plot (CAT) method to approach the optimal activity of the encapsulated enzyme BCL and revealed a nonlinear correlation, first incremental and then decremental, between the BCL activity and the hydrophilic linker' ratios in MTV-ZIF-8. These findings indicated there is a spatial arrangement of functional groups along the three-dimensional space across the ZIF-8 crystal with a unique sequence that could change the enzyme structure between closed-lid and open-lid conformations. These conformation changes were confirmed by FTIR spectra and fluorescence studies. The optimized BCL@ZIF-8 is not only thermally and chemically more stable than free BCL in solution, but also doubles the catalytic reactivity in the kinetic resolution reaction with 99% ee of the products.
We
report a dual-interfacial engineering approach that uses a sub-20
nm polycrystalline MOF-74 shell as a transition phase to engineer
the MOF–polymer interface. The application of a shell MOF layer
divides the original single interface problem into two interfaces:
MOF–MOF and MOF–polymer, which can be individually addressed.
The greater external surface area created by the uneven MOF-74 shell
containing high-density open metal sites allows the MOF to interact
with 300% polymer at the interface compared to traditional MOF, thereby
ensuring good interfacial compatibility. When applied on UiO-66-NH2, its respective mixed-matrix membranes exhibit a simultaneous
increase of CO2/CH4 separation selectivity and
CO2 permeability with increasing MOF loading, implying
a defect-free interface. When applied on MOF-801, the mixed-matrix
membranes exhibit an ethylene/ethane separation selectivity up to
5.91, a drastic 76% increase compared to that of the neat polymer
owing to a “gas focusing” mechanism promoted by the
preferred pore orientation in the MOF-74 layer. This represents one
of the most selective ethylene/ethane separation membranes reported
to date.
Cytogenetic and histopathologic data were correlated with clinical parameters from 423 patients with non-Hodgkin's lymphoma (NHL). Clinical correlations were performed on subgroups of 149 patients with low-grade lymphoma (LG) and 205 patients with diffuse lymphoma with a large cell component (DLLC). Correlations were made between clinical outcome and individual recurring cytogenetic aberrations, each of which was noted in greater than 5% of cases belonging to LG NHL and DLLC, and derived measures of karyotypic complexity, comprising modal chromosome number, number of marker chromosomes, and number of translocation breakpoints. No correlations with survival were noted in LG NHL, although median follow-up was only 2 years. Seven patients with t(8;14) LG NHL had an indolent course. Among 104 patients with DLLC and abnormal karyotypes at diagnosis, breaks at 1q21–23 or more than 4 marker chromosomes was associated with a shortened median survival. Using these variables we constructed a proportional hazards model with a good fit to observed data. Breaks at 6q21–25 predicted a decreased probability of achieving remission. Patients with DLLC and breaks at 1q21–23 or 1p32–36 had a shorter duration of complete remission. Of 41 DLLC studied at relapse, the only long-term survivors had t(14;18).
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