Metal-Organic Material Polymer Coatings for Enhanced Gas Sorption Performance and Hydrolytic Stability under Humid Conditions.

Physisorbent metal-organic materials (MOMs) have shown benchmark performance for highly selective CO capture from bulk and trace gas mixtures. However, gas stream moisture can be detrimental to both adsorbent performance and hydrolytic stability. One of the most effective methods to solve this issue is to transform the adsorbent surface from hydrophilic to hydrophobic.

Highly selective CO removal for one-step liquefied natural gas processing by physisorbents.

Industrial specifications require CO2 concentrations in natural gas below 50 ppm during liquefaction because of corrosion and CO2 freezing. Herein, we report a physisorbent (TIFSIX-3-Ni) that exhibits new benchmark CO2/CH4 selectivity and fast kinetics, thereby enabling one-step LNG processing to CO2 levels of 25 ppm.

Reversible Switching between Highly Porous and Nonporous Phases of an Interpenetrated Diamondoid Coordination Network That Exhibits Gate-Opening at Methane Storage Pressures.

Herein, we report that a new flexible coordination network, NiL (L=4-(4-pyridyl)-biphenyl-4-carboxylic acid), with diamondoid topology switches between non-porous (closed) and several porous (open) phases at specific CO and CH pressures. These phases are manifested by multi-step low-pressure isotherms for CO or a single-step high-pressure isotherm for CH . The potential methane working capacity of NiL approaches that of compressed natural gas but at much lower pressures.

Controlling the Uptake and Regulating the Release of Nitric Oxide in Microporous Solids.

Representative compounds from three classes of microporous solids, namely, metal-organic frameworks (MOFs), hybrid ultra-microporous materials (HUMs), and porous-organic polymers (POPs), were investigated for their nitric oxide gas uptake and release behavior. Low-pressure sorption studies indicated strong chemisorption of NO on the free amine groups decorating the MOF UiO-66-NH when compared to its non-amine-functionalized parent. The HUMs demonstrated reversible physisorption within the low-pressure regime, but interestingly in one case there was evidence for chemisorption following pressurization with NO at 10 bar.

The effect of centred versus offset interpenetration on CH sorption in hybrid ultramicroporous materials.

Fine-tuning of hybrid ultramicroporous materials (HUMs) can significantly impact their gas sorption performance. This study reveals that offset interpenetration can be antagonistic with respect to CH separation from CH/CH gas mixtures.

Hybrid ultramicroporous materials (HUMs) with enhanced stability and trace carbon capture performance.

Fine-tuning of HUMs through pillar substitution can significantly enhance trace CO sorption performance and stability. The resulting materials, exemplified by the new material TIFSIX-3-Ni, [Ni(pyrazine)(TiF)], are shown through temperature programmed desorption experiments to remove trace quantities of CO from moist gas mixtures.

Flue-gas and direct-air capture of CO2 by porous metal-organic materials.

Sequestration of CO, either from gas mixtures or directly from air (direct air capture), is a technological goal important to large-scale industrial processes such as gas purification and the mitigation of carbon emissions. Previously, we investigated five porous materials, three porous metal-organic materials (MOMs), a benchmark inorganic material, ZEOLITE 13X: and a chemisorbent, TEPA-SBA-15: , for their ability to adsorb CO directly from air and from simulated flue-gas. In this contribution, a further 10 physisorbent materials that exhibit strong interactions with CO have been evaluated by temperature-programmed desorption for their potential utility in carbon capture applications: four hybrid ultramicroporous materials, SIFSIX-3-CU: , DICRO-3-NI-I: , SIFSIX-2-CU-I: and MOOFOUR-1-NI: ; five microporous MOMs, DMOF-1: , ZIF-8: , MIL-101: , UIO-66: and UIO-66-NH2: ; an ultramicroporous MOM, NI-4-PYC: The performance of these MOMs was found to be negatively impacted by moisture.

Tuning Pore Size in Square-Lattice Coordination Networks for Size-Selective Sieving of CO2.

Porous materials capable of selectively capturing CO2 from flue-gases or natural gas are of interest in terms of rising atmospheric CO2 levels and methane purification. Size-exclusive sieving of CO2 over CH4 and N2 has rarely been achieved. Herein we show that a crystal engineering approach to tuning of pore-size in a coordination network, [Cu(quinoline-5-carboxyate)2 ]n (Qc-5-Cu) ena+bles ultra-high selectivity for CO2 over N2 (SCN ≈40 000) and CH4 (SCM ≈3300).

A rare cationic building block that generates a new type of polyhedral network with "cross-linked" pto topology.

A rare 8-connected cationic building block, [Cu2L8(μ-MF6)](2+) (L = pyridyl ligand, M = Si, Ti, Ge, Zr or Sn), enables the formation of a small cubicuboctahedral supramolecular building block, SBB, when complexed by 2,4,6-tris(4-pyridyl)pyridine. The coordination network resulting from fusing the square faces of the SBBs can be described as a pto topology in which half of the square faces are cross-linked by MF6(2-) moieties, and represents the first example of a new 3,5-c topology.

Direct Air Capture of CO2 by Physisorbent Materials.

Sequestration of CO2, either from gas mixtures or directly from air (direct air capture, DAC), could mitigate carbon emissions. Here five materials are investigated for their ability to adsorb CO2 directly from air and other gas mixtures. The sorbents studied are benchmark materials that encompass four types of porous material, one chemisorbent, TEPA-SBA-15 (amine-modified mesoporous silica) and four physisorbents: Zeolite 13X (inorganic); HKUST-1 and Mg-MOF-74/Mg-dobdc (metal-organic frameworks, MOFs); SIFSIX-3-Ni, (hybrid ultramicroporous material).

Novel mode of 2-fold interpenetration observed in a primitive cubic network of formula [Ni(1,2-bis(4-pyridyl)acetylene)2(Cr2O7)]n.

A primitive cubic (pcu) network of formula [Ni(1,2-bis(4-pyridyl)acetylene)2(Cr2O7)]n, , has been synthesised and found to exhibit a novel type of inclined 2-fold interpenetration and an isosteric heat of adsorption (Q(st)) of 30.5 kJ mol(-1) towards CO2 at zero loading. Q(st) is relatively high in the broad context but less than that observed in related hybrid ultramicroporous materials, a feature that can be understood after studying pore structure and molecular simulations of CO2 adsorption.

Crystal Structure of Human DNA Methyltransferase 1.

DNMT1 (DNA methyltransferase 1) is responsible for propagating the DNA methylation patterns during DNA replication. DNMT1 contains, in addition to a C-terminal methyltransferase domain, a large N-terminal regulatory region that is composed of an RFTS (replication foci targeting sequence) domain, a CXXC zinc finger domain and a pair of BAH (bromo adjacent homology) domains. The regulatory domains of DNMT1 mediate a network of protein-protein and protein-DNA interactions to control the recruitment and enzymatic activity of DNMT1.

Screening metal-organic frameworks for selective noble gas adsorption in air: effect of pore size and framework topology.

The adsorption of noble gases and nitrogen by sixteen metal-organic frameworks (MOFs) was investigated using grand canonical Monte Carlo simulation. The MOFs were chosen to represent a variety of net topologies, pore dimensions, and metal centers. Three commercially available MOFs (HKUST-1, AlMIL-53, and ZIF-8) and PCN-14 were also included for comparison.

State-granted practice authority: do nurse practitioners vote with their feet?

Nurse practitioners have become an increasingly important part of the US medical workforce as they have gained greater practice authority through state-level regulatory changes. This study investigates one labor market impact of this large change in nurse practitioner regulation. Using data from the National Sample Survey of Registered Nurses and a dataset of state-level nurse practitioner prescribing authority, a multivariate estimation is performed analysing the impact of greater practice authority on the probability of a nurse practitioner moving from a state.

Study of polymeric interactions of copolymers: 2-hydroxyethyl methacrylate (HEMA) and 2,3-dihydroxypropyl methacrylate (DHPMA) with copper hydroxylated nanoballs.

2-hydroxyethyl methacrylate (HEMA) and 2,3-dihydroxypropyl methacrylate (DHPMA) were used to synthesize novel nanocomposites containing 0.5% by weight of copper hydroxylated nanoballs. Glass transition temperatures of the copolymers and their respective nanocomposites were determined by using differential scanning calorimetry (DSC).

Assessing the purity of metal-organic frameworks using photoluminescence: MOF-5, ZnO quantum dots, and framework decomposition.

Photoluminescence (PL) spectroscopy was used to characterize nanoscale ZnO impurities, amine-donor charge-transfer exciplexes, and framework decomposition in samples of MOF-5 prepared by various methods. The combined results cast doubt on previous reports describing MOF-5 as a semiconductor and demonstrate that PL as a tool for characterizing MOF purity possesses advantages such as simplicity, speed, and sensitivity over currently employed powder XRD MOF characterization methods.

Managing bone deficiency and nonunions of the proximal femur.

Revision surgery of the proximal femur with bone loss secondary to failed cephalomedullary nails is problematic and becoming more prevalent as their use grows. This article presents a technique of deformity correction, bone graft techniques that reconstitute residual defects, and definitive fixation using load-sharing devices that provide immediate stability for bone healing and early rehabilitation. Preoperative planning and the potential advantages and disadvantages of newer fixed-angled plates versus established implants are discussed.

Design and synthesis of metal-organic frameworks using metal-organic polyhedra as supermolecular building blocks.

This critical review highlights supermolecular building blocks (SBBs) in the context of their impact upon the design, synthesis, and structure of metal-organic materials (MOMs). MOMs, also known as coordination polymers, hybrid inorganic-organic materials, and metal-organic frameworks, represent an emerging class of materials that have attracted the imagination of solid-state chemists because MOMs combine unprecedented levels of porosity with a range of other functional properties that occur through the metal moiety and/or the organic ligand. First generation MOMs exploited the geometry of metal ions or secondary building units (SBUs), small metal clusters that mimic polygons, for the generation of MOMs.

Hematogenous septic arthritis of the adult hip.

A retrospective review of 10 patients admitted to 4 regional hospitals between 1987 and 1997 in whom acute septic hip arthritis was diagnosed was performed to compare presentation, laboratory and radiographic findings, treatment, and outcome. Patients presented with fever, hip or groin pain, and an inability to bear weight. Most patients manifested a leukocytosis, and all patients had an elevated erythrocyte sedimentation rate.

Thermal capsulorraphy of bilateral glenohumeral joints in a pediatric patient with Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is a heterogeneous collection of inherited connective tissue disorders characterized by hypermobility of the joints and hyperextensibility and fragility of the skin. For many patients, the hypermobile joints become problematic. To date, the mainstay of surgical treatment for EDS-related joint laxity has been open surgical capsulorraphy, which, although usually effective, confers significant morbidity to the patient.