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Separating ethane (C2H6) from ethylene (C2H4) is an essential and energy-intensive process in the chemical industry. Here, we report two flexible diamondoid coordination networks, X-dia-1-Ni and X-dia-1-Ni0.89Co0.11, that exhibit gate-opening between narrow-pore (NP) and large-pore (LP) phases for C2H6, but not for C2H4. X-dia-1-Ni0.89Co0.11 thereby exhibited a type F-IV isotherm at 273 K with no C2H6 uptake and a high uptake (111 cm3 g-1, 1 atm) for the NP and LP phases, respectively. Conversely, the LP phase exhibited a low uptake of C2H4 (12.2 cm3 g-1). This C2H6/C2H4 uptake ratio of 9.1 for X-dia-1-Ni0.89Co0.11 far surpassed those of previously reported physisorbents, many of which are C2H4-selective. In situ variable-pressure X-ray diffraction and modeling studies provided insight into the abrupt C2H6-induced structural NP to LP transformation. The promise of pure gas isotherms and, more generally, flexible coordination networks for gas separations was validated by dynamic breakthrough studies, which afforded high-purity (99.9%) C2H4 in one step.
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Background: The care for patients with type 2 diabetes mellitus (T2DM) necessitates a multidisciplinary team approach to reduce cardiovascular (CV) risk but implementation of effective integrated strategies has been limited. Methods and Results: We report 2-year results from a patient-centered, team-based intervention called CINEMA at University Hospitals Cleveland Medical Center. Patients with T2DM or prediabetes at high-risk for CV events, including those with established atherosclerotic CVD, elevated coronary artery calcium score ≥100, chronic heart failure with reduced ejection fraction, chronic kidney disease (CKD) stages 2-4, and/or prevalent metabolic syndrome were included. From May 2020 through September 2022, 426 patients were enrolled in the CINEMA program. A total of 227 (54%) completed ≥1 follow-up visit after an initial baseline visit with median (IQR) follow-up time 4 [3], [4], [5], [6], [7] months with maximum follow-up time 19 months. Mean age was 60 years, 47 % were women, and 37 % were Black and 85% had prevalent T2DM, 48 % had established ASCVD, 29% had chronic HF, 27% had CKD and mean baseline 10-year ASCVD risk estimate was 25.1 %; baseline use of a SGLT2i or GLP-1RA was 21 % and 18 %, respectively. Patients had significant reductions from baseline in body weight (-5.5 lbs), body mass index (-0.9 kg/m2), systolic (-3.6 mmHg) and diastolic (-1.2 mmHg) blood pressure, Hb A1c (-0.5 %), total (-10.7 mg/dL) and low-density lipoprotein (-9.0 mg/dL) cholesterol, and triglycerides (-13.5 mg/dL) (p<0.05 for all). Absolute 10-year predicted ASCVD risk decreased by â¼2.4 % (p<0.001) with the intervention. In addition, rates of guideline-directed cardiometabolic medication prescriptions significantly increased during follow-up with the most substantive changes seen in rates of SGLT2i and GLP-1RA use which approximately tripled from baseline (21 % to 57 % for SGLT2i and 18 % to 65 % for GLP-1RA, p<0.001 for both). Conclusions: The CINEMA program, an integrated, patient-centered, team-based intervention for patients with T2DM or prediabetes at high risk for cardiovascular disease has continued to demonstrate effectiveness with significant improvements in ASCVD risk factors and improved use of evidence-based therapies. Successful implementation and dissemination of this care delivery paradigm remains a key priority.
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Purification of ethylene (C2H4) as the most extensive and output chemical, from complex multi-components is of great significance but highly challenging. Herein we demonstrate that precise pore structure tuning by controlling the network hydrogen bonds in two highly-related porous coordination networks can shift the efficient C2H4 separation function from C2H2/C2H4/C2H6 ternary mixture to CO2/C2H2/C2H4/C2H6 quaternary mixture system. Single-crystal X-ray diffraction revealed that the different amino groups on the triazolate ligands resulted in the change of the hydrogen bonding in the host network, which led to changes in the pore shape and pore chemistry. Gas adsorption isotherms, adsorption kinetics and gas-loaded crystal structure analysis indicated that the coordination network Zn-fa-atz (2) weakened the affinity for three C2 hydrocarbons synchronously including C2H4 but enhanced the CO2 adsorption due to the optimized CO2-host interaction and the faster CO2 diffusion, leading to effective C2H4 production from the CO2/C2H2/C2H4/C2H6 mixture in one step based on the experimental and simulated breakthrough data. Moreover, it can be shaped into spherical pellets with maintained porosity and separation performance.
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BACKGROUND: Cells orchestrate histone biogenesis with strict temporal and quantitative control. To efficiently regulate histone biogenesis, the repetitive Drosophila melanogaster replication-dependent histone genes are arrayed and clustered at a single locus. Regulatory factors concentrate in a nuclear body known as the histone locus body (HLB), which forms around the locus. Historically, HLB factors are largely discovered by chance, and few are known to interact directly with DNA. It is therefore unclear how the histone genes are specifically targeted for unique and coordinated regulation. RESULTS: To expand the list of known HLB factors, we performed a candidate-based screen by mapping 30 publicly available ChIP datasets of 27 unique factors to the Drosophila histone gene array. We identified novel transcription factor candidates, including the Drosophila Hox proteins Ultrabithorax (Ubx), Abdominal-A (Abd-A), and Abdominal-B (Abd-B), suggesting a new pathway for these factors in influencing body plan morphogenesis. Additionally, we identified six other factors that target the histone gene array: JIL-1, hormone-like receptor 78 (Hr78), the long isoform of female sterile homeotic (1) (fs(1)h) as well as the general transcription factors TBP associated factor 1 (TAF-1), Transcription Factor IIB (TFIIB), and Transcription Factor IIF (TFIIF). CONCLUSIONS: Our foundational screen provides several candidates for future studies into factors that may influence histone biogenesis. Further, our study emphasizes the powerful reservoir of publicly available datasets, which can be mined as a primary screening technique.
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Proteínas de Drosophila , Infertilidade , Feminino , Animais , Drosophila , Drosophila melanogaster/genética , Histonas/genética , Montagem e Desmontagem da Cromatina/genética , Biologia Computacional , Proteínas de Drosophila/genética , Fatores de Transcrição/genética , Proteínas de Homeodomínio/genética , Proteínas Serina-Treonina QuinasesRESUMO
A metal-organic framework, SDMOF-1, with rigid pores of about 3.4 Å, which is appropriate for accommodating C2H2 molecules, exhibits high C2H2 adsorption capacity and great separation capability of the C2H2/C2H4 mixture. This work provides a new method to design aliphatic MOFs with a molecular sieving effect to realize efficient gas separation.
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An emerging strategy in the design of efficient gas storage technologies is the development of stimuli-responsive physisorbents which undergo transformations in response to a particular stimulus, such as pressure, heat or light. Herein, we report two isostructural light modulated adsorbents (LMAs) containing bis-3-thienylcyclopentene (BTCP), LMA-1 [Cd(BTCP)(DPT)2 ] (DPT=2,5-diphenylbenzene-1,4-dicarboxylate) and LMA-2 [Cd(BTCP)(FDPT)2 ] (FDPT=5-fluoro-2,diphenylbenzene-1,4-dicarboxylate). Both LMAs undergo pressure induced switching transformations from non-porous to porous via adsorption of N2 , CO2 and C2 H2 . LMA-1 exhibited multi-step adsorption while LMA-2 showed a single-step adsorption isotherm. The light responsive nature of the BTPC ligand in both frameworks was exploited with irradiation of LMA-1 resulting in a 55 % maximum reduction of CO2 uptake at 298â K. This study reports the first example of a switching sorbent (closed to open) that can be further modulated by light.
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Flexible metal-organic materials that exhibit stimulus-responsive switching between closed (non-porous) and open (porous) structures induced by gas molecules are of potential utility in gas storage and separation. Such behaviour is currently limited to a few dozen physisorbents that typically switch through a breathing mechanism requiring structural contortions. Here we show a clathrate (non-porous) coordination network that undergoes gas-induced switching between multiple non-porous phases through transient porosity, which involves the diffusion of guests between discrete voids through intra-network distortions. This material is synthesized as a clathrate phase with solvent-filled cavities; evacuation affords a single-crystal to single-crystal transformation to a phase with smaller cavities. At 298 K, carbon dioxide, acetylene, ethylene and ethane induce reversible switching between guest-free and gas-loaded clathrate phases. For carbon dioxide and acetylene at cryogenic temperatures, phases showing progressively higher loadings were observed and characterized using in situ X-ray diffraction, and the mechanism of diffusion was computationally elucidated.
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Cells orchestrate histone biogenesis with strict temporal and quantitative control. To efficiently regulate histone biogenesis, the repetitive Drosophila melanogaster replication-dependent histone genes are arrayed and clustered at a single locus. Regulatory factors concentrate in a nuclear body known as the histone locus body (HLB), which forms around the locus. Historically, HLB factors are largely discovered by chance, and few are known to interact directly with DNA. It is therefore unclear how the histone genes are specifically targeted for unique and coordinated regulation. To expand the list of known HLB factors, we performed a candidate-based screen by mapping 30 publicly available ChIP datasets and 27 factors to the Drosophila histone gene array. We identified novel transcription factor candidates, including the Drosophila Hox proteins Ultrabithorax, Abdominal-A and Abdominal-B, suggesting a new pathway for these factors in influencing body plan morphogenesis. Additionally, we identified six other transcription factors that target the histone gene array: JIL-1, Hr78, the long isoform of fs(1)h as well as the generalized transcription factors TAF-1, TFIIB, and TFIIF. Our foundational screen provides several candidates for future studies into factors that may influence histone biogenesis. Further, our study emphasizes the powerful reservoir of publicly available datasets, which can be mined as a primary screening technique.
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Two C2 H6 -selective metal-organic framework (MOF) adsorbents with ultrahigh stability, high surface areas, and suitable pore size have been designed and synthesized for one-step separation of ethane/ethylene (C2 H6 /C2 H4 ) under humid conditions to produce polymer-grade pure C2 H4 . Experimental results reveal that these two MOFs not only adsorb a high amount of C2 H6 but also display good C2 H6 /C2 H4 selectivity verified by fixed bed column breakthrough experiments. Most importantly, the good water stability and hydrophobic pore environments make these two MOFs capable of efficiently separating C2 H6 /C2 H4 under humid conditions, exhibiting the benchmark performance among all reported adsorbents for separation of C2 H6 /C2 H4 under humid conditions. Moreover, the affinity sites and their static adsorption energies were successfully revealed by single crystal data and computation studies. Adsorbents described in this work can be used to address major chemical industrial challenges.
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A gradual amide truncation strategy was presented to tune the pore chemistry and CO2 capture performance of a series of tetracarboxylate-based Cu-MOFs. These MOFs exhibited a high density of Lewis basic sites (LBSs) and open metal sites and were prepared with the goal to enhance CO2 selective adsorption capacity. [Cu2(L1)(H2O)2]n (NJU-Bai42: NJU-Bai for Nanjing University Bai's group), [Cu2(L2) (H2O)2]n (NJU-Bai17), and [Cu2(L3)(H2O)2]n (NTUniv-60: NTUniv for Nantong University) were synthesized, and we observed that the CO2 adsorption capacities and MOF structures were impacted by subtle changes in ligands. Interestingly, although the NTUniv-60 was decorated with the least LBSs in these three MOFs, its CO2 adsorption capacity reached 270 (53.0 wt %) and 164 (32.2 wt %) cm3 g-1 at 273 and 296 K under 1 bar, respectively, which is the highest data reported for MOFs under similar conditions. From the grand canonical Monte Carlo (GCMC) simulation, the cooperative interactions between the CO2 molecules within the shuttle-shaped cages of NTUniv-60 could potentially explain why the CO2 uptake is high in this material.
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Dióxido de Carbono , Bases de Lewis , Humanos , Adsorção , Amidas , Transporte BiológicoRESUMO
A combined experimental and theoretical study of H2 adsorption was carried out in Co-CUK-1 and Mg-CUK-1, two isostructural metal-organic frameworks (MOFs) that consist of M2+ ions (M = Co and Mg) coordinated to pyridine-2,4-dicarboxylate (pdc2-) and OH- ligands. These MOFs possess saturated metal centers in distorted octahedral environments and narrow pore sizes and display high chemical and thermal stability. Previous experimental studies revealed that Co-CUK-1 exhibits a H2 uptake of 183 cm3 g-1 at 77 K/1.0 atm [ Angew. Chem., Int. Ed. 2007, 46, 272-275, DOI: 10.1002/anie.200601627], while that for Mg-CUK-1 under the same conditions is 240 cm3 g-1 on the basis of the experimental measurements carried out herein. The theoretical H2 adsorption isotherms are in close agreement with the corresponding experimental measurements for simulations using electrostatic and polarizable potentials of the adsorbate. Through simulated annealing calculations, it was found that the primary binding site for H2 in both isostructural analogues is localized proximal to the center of the aromatic rings belonging to the pdc2- linkers. Inelastic neutron scattering (INS) spectroscopic studies of H2 adsorbed in both MOFs revealed a rotational tunnelling transition occurring at around 8 meV in the corresponding spectra; this peak represents H2 adsorbed at the primary binding site. Two-dimensional quantum rotation calculations for H2 localized at the primary and secondary binding sites in both MOFs yielded rotational energy levels that are in agreement with the transitions observed in the INS spectra. Even though both M-CUK-1 analogues possess different metal ions, they exhibit similar electrostatic environments, modeled structures at H2 saturation, and rotational potentials for H2 adsorbed at the most favorable adsorption site. Overall, this study demonstrates how important molecular-level details of the H2 adsorption mechanism inside MOF micropores can be derived from a combination of experimental measurements and theoretical calculations using two stable and isostructural MOFs with saturated metal centers and small pore windows as model systems.
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The capture of the xenon and krypton from nuclear reprocessing off-gas is essential to the treatment of radioactive waste. Although various porous materials have been employed to capture Xe and Kr, the development of high-performance adsorbents capable of trapping Xe/Kr at very low partial pressure as in the nuclear reprocessing off-gas conditions remains challenging. Herein, we report a self-adjusting metal-organic framework based on multiple weak binding interactions to capture trace Xe and Kr from the nuclear reprocessing off-gas. The self-adjusting behavior of ATC-Cu and its mechanism have been visualized by the in-situ single-crystal X-ray diffraction studies and theoretical calculations. The self-adjusting behavior endows ATC-Cu unprecedented uptake capacities of 2.65 and 0.52â mmol g-1 for Xe and Kr respectively at 0.1â bar and 298â K, as well as the record Xe capture capability from the nuclear reprocessing off-gas. Our work not only provides a benchmark Xe adsorbent but proposes a new route to construct smart materials for efficient separations.
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The removal of carbon dioxide (CO2) from acetylene (C2H2) is a critical industrial process for manufacturing high-purity C2H2. However, it remains challenging to address the tradeoff between adsorption capacity and selectivity, on account of their similar physical properties and molecular sizes. To overcome this difficulty, here we report a novel strategy involving the regulation of a hydrogen-bonding nanotrap on the pore surface to promote the separation of C2H2/CO2 mixtures in three isostructural metal-organic frameworks (MOFs, named MIL-160, CAU-10H, and CAU-23, respectively). Among them, MIL-160, which has abundant hydrogen-bonding acceptors as nanotraps, can selectively capture acetylene molecules and demonstrates an ultrahigh C2H2 storage capacity (191 cm3 g-1, or 213 cm3 cm-3) but much less CO2 uptake (90 cm3 g-1) under ambient conditions. The C2H2 adsorption amount of MIL-160 is remarkably higher than those for the other two isostructural MOFs (86 and 119 cm3 g-1 for CAU-10H and CAU-23, respectively) under the same conditions. More importantly, both simulation and experimental breakthrough results show that MIL-160 sets a new benchmark for equimolar C2H2/CO2 separation in terms of the separation potential (Δqbreak = 5.02 mol/kg) and C2H2 productivity (6.8 mol/kg). In addition, in situ FT-IR experiments and computational modeling further reveal that the unique host-guest multiple hydrogen-bonding interaction between the nanotrap and C2H2 is the key factor for achieving the extraordinary acetylene storage capacity and superior C2H2/CO2 selectivity. This work provides a novel and powerful approach to address the tradeoff of this extremely challenging gas separation.
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A combined experimental and theoretical study of C2H2 and CO2 adsorption and separation was performed in two isostructural molecular porous materials (MPMs): MPM-1-Cl ([Cu2(adenine)4Cl2]Cl2) and MPM-1-TIFSIX ([Cu2(adenine)4(TiF6)2]). It was revealed that MPM-1-Cl displayed higher low-pressure uptake, isosteric heat of adsorption (Qst), and selectivity for C2H2 than CO2, whereas the opposite was observed for MPM-1-TIFSIX. While MPM-1-Cl contains only one type of accessible channel, which has a greater preference toward C2H2, MPM-1-TIFSIX contains three distinct accessible channels, one of which is a confined region between two large channels that represents the primary binding site for both adsorbates. According to molecular simulations, the initial adsorption site in MPM-1-TIFSIX interacts more strongly with CO2 than C2H2, thus explaining the inversion of adsorbate selectivity relative to MPM-1-Cl.
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The trade-off between selectivity and adsorption capacity with porous materials is a major roadblock to reducing the energy footprint of gas separation technologies. To address this matter, we report herein a systematic crystal engineering study of C2H2 removal from CO2 in a family of hybrid ultramicroporous materials (HUMs). The HUMs are composed of the same organic linker ligand, 4-(3,5-dimethyl-1H-pyrazol-4-yl)pyridine, pypz, three inorganic pillar ligands, and two metal cations, thereby affording six isostructural pcu topology HUMs. All six HUMs exhibited strong binding sites for C2H2 and weaker affinity for CO2. The tuning of pore size and chemistry enabled by crystal engineering resulted in benchmark C2H2/CO2 separation performance. Fixed-bed dynamic column breakthrough experiments for an equimolar (v/v = 1:1) C2H2/CO2 binary gas mixture revealed that one sorbent, SIFSIX-21-Ni, was the first C2H2 selective sorbent that combines exceptional separation selectivity (27.7) with high adsorption capacity (4 mmol·g-1).
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One-step adsorptive purification of ethylene (C2H4) from four-component gas mixtures comprising acetylene (C2H2), ethylene (C2H4), ethane (C2H6) and carbon dioxide (CO2) is an unmet challenge in the area of commodity purification. Herein, we report that the ultramicroporous sorbent Zn-atz-oba (H2oba = 4,4-dicarboxyl diphenyl ether; Hatz = 3-amino-1,2,4-triazole) enables selective adsorption of C2H2, C2H6 and CO2 over C2H4 thanks to the binding sites that lie in its undulating pores. Molecular simulations provide insight into the binding sites in Zn-atz-oba that are responsible for coadsorption of C2H2, C2H6 and CO2 over C2H4. Dynamic breakthrough experiments demonstrate that the selective binding exhibited by Zn-atz-oba can produce polymer-grade purity (>99.95%) C2H4 from binary (1:1 for C2H4/C2H6), ternary (1:1:1 for C2H2/C2H4/C2H6) and quaternary (1:1:1:1 for C2H2/C2H4/C2H6/CO2) gas mixtures in a single step.
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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.
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The propensity of molecular organic compounds to form stoichiometric or nonstoichiometric crystalline hydrates remains a challenging aspect of crystal engineering and is of practical relevance to fields such as pharmaceutical science. In this work, we address the propensity for hydrate formation of a library of eight compounds comprised of 5- and 6-membered N-heterocyclic aromatics classified into three subgroups: linear dipyridyls, substituted Schiff bases, and tripodal molecules. Each molecular compound studied possesses strong hydrogen bond acceptors and is devoid of strong hydrogen bond donors. Four methods were used to screen for hydrate propensity using the anhydrate forms of the molecular compounds in our library: water slurry under ambient conditions, exposure to humidity, aqueous solvent drop grinding (SDG), and dynamic water vapor sorption (DVS). In addition, crystallization from mixed solvents was studied. Water slurry, aqueous SDG, and exposure to humidity were found to be the most effective methods for hydrate screening. Our study also involved a structural analysis using the Cambridge Structural Database, electrostatic potential (ESP) maps, full interaction maps (FIMs), and crystal packing motifs. The hydrate propensity of each compound studied was compared to a compound of the same type known to form a hydrate through a previous study of ours. Out of the eight newly studied compounds (herein numbered 4-11), three Schiff bases were observed to form hydrates. Three crystal structures (two hydrates and one anhydrate) were determined. Compound 6 crystallized as an isolated site hydrate in the monoclinic space group P21/a, while 7 and 10 crystallized in the monoclinic space group P21/c as a channel tetrahydrate and an anhydrate, respectively. Whereas we did not find any direct correlation between the number of H-bond acceptors and either hydrate propensity or the stoichiometry of the resulting hydrates, analysis of FIMs suggested that hydrates tend to form when the corresponding anhydrate structure does not facilitate intermolecular interactions.
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An In(III) based metal-organic framework (MOF), In-pbpta, with soc topology was constructed from the trigonal prismatic [In3(µ3-O)(H2O)3(O2C-)6] secondary building unit (SBU) and a custom-designed tetratopic linker H4pbpta (pbpta = 4,4',4â³,4â´-(1,4-phenylenbis(pyridine-4,2,6-triyl))-tetrabenzoic acid)). The obtained MOF shows a Brunauer-Emmett-Teller surface area of 1341 m2/g with a pore volume of 0.64 cm3/g, which is the highest among the scarcely reported In-soc-MOFs. The constructed MOF demonstrates excellent performance as a heterogeneous Lewis acid catalyst for highly efficient conversion in a one-pot multicomponent Strecker reaction for the preparation of α-aminonitriles under solvent-free conditions, which can be easy to separate and recycle without significant loss of activity for up to seven cycles. The computational modeling studies suggest the presence of the three substrates in close vicinity to the In-oxo cluster. The strong interactions of the aldehyde/ketone and the amine with the In-oxo cluster together with the readily available cyanide ion around the In-oxo cluster lead to high catalytic conversion within a short period of time for the MOF catalyst. Our work therefore lays a foundation to develop MOF as a new class of efficient heterogeneous catalyst for one-pot Strecker reaction.