PHAHST Potential: Modeling Sorption in a Dispersion-Dominated Environment.

PHAHST (potentials with high accuracy, high speed, and transferability) is a recently developed force field that utilizes exponential repulsion, multiple dispersion terms, explicit many-body polarization, and many-body van der Waals interactions. The result is a systematic approach to force field development that is computationally practical. Here, PHAHST is employed in the simulation for rare gas uptake of krypton and xenon in the metal-organic material, HKUST-1. This material has shown promise in use as an adsorptive separating agent and presents a challenge to model due to the presence of heterogeneous interaction sorption surfaces, which include pores with readily accessible, open-metal sites that compete with dispersion-dominated pores. Such environments are difficult to simulate with commonly used empirical force fields, such as the Lennard-Jones (LJ) potential, which perform better when electrostatics are dominant in determining the nature of sorption and alone are incapable of modeling interactions with open-metal sites. The effectiveness of PHAHST is compared to the LJ potential in a series of mixed Kr-Xe gas simulations. It has been demonstrated that PHAHST compares favorably with experimental results, and the LJ potential is inadequate. Overall, we establish that force fields with physically grounded repulsion/dispersion terms are required in order to accurately model sorption, as these interactions are an important component of the energy. Furthermore, it is shown that the simple mixing rules work nearly quantitatively for the true pair potentials, while they are not transferable for effective potentials like LJ.

Trailblazing Kr/Xe Separation: The Birth of the First Kr-Selective Material.

Efficient separation of Kr from Kr/Xe mixtures is pivotal in nuclear waste management and dark matter research. Thus far, scientists have encountered a formidable challenge: the absence of a material with the ability to selectively adsorb Kr over Xe at room temperature. This study presents a groundbreaking transformation of the renowned metal-organic framework (MOF) CuBTC, previously acknowledged for its Xe adsorption affinity, into an unparalleled Kr-selective adsorbent. This achievement stems from an innovative densification approach involving systematic compression of the MOF, where the crystal size, interparticle interaction, defects, and evacuation conditions are synergistically modulated. The resultant densified CuBTC phase exhibits exceptional mechanical resilience, radiation tolerance, and notably an unprecedented selectivity for Kr over Xe at room temperature. Simulation and experimental kinetic diffusion studies confirm reduced gas diffusion in the densified MOF, attributed to its small pore window and minimal interparticle voids. The lighter Kr element demonstrates facile surface passage and higher diffusivity within the material, while the heavier Xe encounters increased difficulty entering the material and lower diffusivity. This Kr-selective MOF not only represents a significant breakthrough in Kr separation but also demonstrates remarkable processability and scalability to kilogram levels. The findings presented herein underscore the transformative potential of engineered MOFs in addressing complex challenges, heralding a new era of Kr separation technologies.

Creating a Guardrail System to Ensure Appropriate Activation of Adolescent Portal Accounts.

The parent of an adolescent patient noticed an upcoming appointment in the patient's portal account that should have remained confidential to the parent. As it turned out, this parent was directly accessing their child's adolescent patient portal account instead of using a proxy account. After investigation of this case, it was found that the adolescent account had been activated with the parent's demographic (i.e., phone/email) information. This case illustrates the challenges of using adult-centric electronic health record (EHR) systems and how our institution addressed the problem of incorrect portal account activations.Confidentiality is fundamental to providing healthcare to adolescents. To comply with the 21st Century Cures Act's information blocking rules, confidential information must be released to adolescent patients when appropriate while also remaining confidential from their guardians. While complying with this national standard, systems of care must also account for interstate variability in which services allow for confidential adolescent consent. Unfortunately, there are high rates of guardian access to adolescent portal accounts which may lead to unintended disclosure of confidential information. Therefore, measures must be taken to minimize the risk of inadvertent confidentiality breaches via adolescent patient portals.Our institution implemented a guardrail system that checks the adolescent patient's contact information against the contact information of their parent/guardian/guarantor. This guardrail reduced the rate of account activation errors after implementation. However, the guardrail can be bypassed when demographic fields are missing. Thus, ongoing efforts to create pediatric-appropriate demographic fields, clearly distinguishing patient from proxy, in the EHR and workflows for registration of proxy accounts in the patient portal are needed.

Tuning the Selectivity between C2H2 and CO2 in Molecular Porous Materials.

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.

Ensuring Adolescent Patient Portal Confidentiality in the Age of the Cures Act Final Rule.

PURPOSE: Managing confidential adolescent health information in patient portals presents unique challenges. Adolescent patients and guardians electronically access medical records and communicate with providers via portals. In confidential matters like sexual health, ensuring confidentiality is crucial. A key aspect of confidential portals is ensuring that the account is registered to and utilized by the intended user. Inappropriately registered or guardian-accessed adolescent portal accounts may lead to confidentiality breaches. METHODS: We used a quality improvement framework to develop screening methodologies to flag guardian-accessible accounts. Accounts of patients aged 12-17 were flagged via manual review of account emails and natural language processing of portal messages. We implemented a reconciliation program to correct affected accounts' registered email. Clinics were notified about sign-up errors and educated on sign-up workflow. An electronic alert was created to check the adolescent's email prior to account activation. RESULTS: After initial screening, 2,307 of 3,701 (62%) adolescent accounts were flagged as registered with a guardian's email. Those accounts were notified to resolve their logins. After five notifications over 8 weeks, 266 of 2,307 accounts (12%) were corrected; the remaining 2,041 (88%) were deactivated. CONCLUSIONS: The finding that 62% of adolescent portal accounts were used/accessed by guardians has significant confidentiality implications. In the context of the Cures Act Final Rule and increased information sharing, our institution's experience with ensuring appropriate access to adolescent portal accounts is necessary, timely, and relevant. This study highlights ways to improve patient portal confidentiality and prompts institutions caring for adolescents to review their systems and processes.

The Value of OpenNotes for Pediatric Patients, Their Families and Impact on the Patient-Physician Relationship.

BACKGROUND: OpenNotes, the sharing of medical notes via a patient portal, has been extensively studied in adults but not in pediatric populations. This has been a contributing factor in the slower adoption of OpenNotes by children's hospitals. The 21st Century Cures Act Final Rule has mandated the sharing of clinical notes electronically to all patients and as health systems prepare to comply, some concerns remain particularly with OpenNotes for pediatric populations. OBJECTIVES: After a gradual implementation of OpenNotes at an academic pediatric center, we sought to better understand how pediatric patients and families perceived OpenNotes. This article presents the detailed steps of this informatics-led rollout and patient survey results with a focus on pediatric-specific concerns. METHODS: We adapted a previous OpenNotes survey used for adult populations to a pediatric outpatient setting (with parents of children <12 years old). The survey was sent to patients and families via a notification email sent as a standard practice after a clinic visit, in English or Spanish. RESULTS: Approximately 7% of patients/families with access to OpenNotes read the note during the study period, and 159 (20%) of those patients responded to the survey. Of the survey respondents, 141 (89%) of patients and families understood their notes; 126 (80%) found the notes always or usually accurate; 24 (15%) contacted their clinicians after reading a note; and 153 (97%) patients/families felt the same or better about their doctor after reading the note. CONCLUSION: Although limited by relatively low survey response rate, OpenNotes was well-received by parents of pediatric patients without untoward consequences. The main concerns pediatricians raise about OpenNotes proved to not be issues in the pediatric population. Our results demonstrate clear benefits to adoption of OpenNotes. This provides reassurance that the transition to sharing notes with pediatric patients can be successful and value additive.

Next-Generation Accurate, Transferable, and Polarizable Potentials for Material Simulations.

PHAHST (potentials with high accuracy, high speed, and transferability) intermolecular potential energy functions have been developed from first principles for H2, N2, the noble gases, and a metal-organic material, HKUST-1. The potentials are designed from the outset to be transferable to heterogeneous environments including porous materials, interfaces, and material simulations. This is accomplished by theoretically justified choices for all functional forms, parameters, and mixing rules, including explicit polarization in every environment and fitting to high quality electronic structure calculations using methods that are tractable for real systems. The models have been validated in neat systems by comparison to second virial coefficients and bulk pressure-density isotherms. For inhomogeneous applications, our main target, comparisons are presented to previously published experimental studies on the metal-organic material HKUST-1 including adsorption, isosteric heats of adsorption, binding site locations, and binding site energies. A systematic prescription is provided for developing compatible potentials for additional small molecules and materials. The resulting models are recommended for use in complex heterogeneous simulations where existing potentials may be inadequate.

Robust Microporous Metal-Organic Frameworks for Highly Efficient and Simultaneous Removal of Propyne and Propadiene from Propylene.

Simultaneous removal of trace amounts of propyne and propadiene from propylene is an important but challenging industrial process. We report herein a class of microporous metal-organic frameworks (NKMOF-1-M) with exceptional water stability and remarkably high uptakes for both propyne and propadiene at low pressures. NKMOF-1-M separated a ternary propyne/propadiene/propylene (0.5 : 0.5 : 99.0) mixture with the highest reported selectivity for the production of polymer-grade propylene (99.996 %) at ambient temperature, as attributed to its strong binding affinity for propyne and propadiene over propylene. Moreover, we were able to visualize propyne and propadiene molecules in the single-crystal structure of NKMOF-1-M through a convenient approach under ambient conditions, which helped to precisely understand the binding sites and affinity for propyne and propadiene. These results provide important guidance on using ultramicroporous MOFs as physisorbent materials.

Simulations of hydrogen, carbon dioxide, and small hydrocarbon sorption in a nitrogen-rich rht-metal-organic framework.

Grand canonical Monte Carlo (GCMC) simulations of gas sorption were performed in Cu-TDPAH, also known as rht-MOF-9, hereafter [1], a metal-organic framework (MOF) with rht topology consisting of Cu2+ ions coordinated to 2,5,8-tris(3,5-dicarboxyphenylamino)-1,3,4,6,7,9,9b-heptaazaphenalene (TDPAH) ligands. This MOF is notable for the presence of open-metal copper sites and high nitrogen content on the linkers. [1] Exhibits one of the highest experimental H2 uptakes at 77 K/1 atm within the extant rht-MOF family (ca. 2.72 wt%) and also has strong affinity for CO2 (5.83 mmol g-1 at 298 K/1 atm). Our simulations, which include explicit many-body polarization interactions, accurately modeled macroscopic thermodynamic properties (e.g., sorption isotherms and isosteric heats of adsorption (Qst)) as well as the binding sites for H2, CO2, CH4, C2H2, C2H4, and C2H6 in the MOF. Four different binding sites were observed through analysis of the radial distribution function (g(r)) about the two chemically distinct Cu2+ ions, simulated annealing calculations, and examination of the three-dimensional histogram showing the sites of occupancy: (1) at the Cu2+ ion facing toward the center of the linker (CuL), (2) at the Cu2+ ion facing away from the center of linker (CuC), (3) nestled between three [Cu2(O2CR)4] units in the corner of the truncated tetrahedral (T-Td) cage and (4) straddling the copper nuclei parallel to the axis of the Cu-Cu bond within the T-Td cage. The low-loading (initial) binding site in the MOF is highly sensitive to the partial charges of the Cu2+ ions that were used for parametrization. It was discovered that most sorbates prefer to sorb onto or near the Cu2+ ions that exhibit the greater partial positive charge (i.e., at site 1). The simulated H2 and CO2 sorption results obtained using a polarizable potential for the respective sorbates are in good agreement with the corresponding experimental data, especially near ambient pressure. Simulations of gas sorption were also performed in [1] using nonpolarizable potentials for the individual sorbates; these include potentials from the TraPPE force field for most sorbates.

Highly Selective Separation of C2H2 from CO2 by a New Dichromate-Based Hybrid Ultramicroporous Material.

A new hybrid ultramicroporous material, [Ni(1,4-di(pyridine-2-yl)benzene)2(Cr2O7)]n (DICRO-4-Ni-i), has been prepared and structurally characterized. Pure gas sorption isotherms and molecular modeling of sorbate-sorbent interactions imply strong selectivity for C2H2 over CO2 (SAC). Dynamic gas breakthrough coupled with temperature-programmed desorption experiments were conducted on DICRO-4-Ni-i and two other porous materials reported to exhibit high SAC, TIFSIX-2-Cu-i and MIL-100(Fe), using a C2H2/CO2/He (10:5:85) gas mixture. Whereas CO2/C2H2 coadsorption by MIL-100(Fe) mitigated the purity of trapped C2H2, negligible coadsorption and high SAC were observed for DICRO-4-Ni-i and TIFSIX-2-Cu-i.

Hybrid Ultra-Microporous Materials for Selective Xenon Adsorption and Separation.

The demand for Xe/Kr separation continues to grow due to the industrial significance of high-purity Xe gas. Current separation processes rely on energy intensive cryogenic distillation. Therefore, less energy intensive alternatives, such as physisorptive separation, using porous materials, are required. Herein we show that an underexplored class of porous materials called hybrid ultra-microporous materials (HUMs) affords new benchmark selectivity for Xe separation from Xe/Kr mixtures. The isostructural materials, CROFOUR-1-Ni and CROFOUR-2-Ni, are coordination networks that have coordinatively saturated metal centers and two distinct types of micropores, one of which is lined by CrO4 (2-) (CROFOUR) anions and the other is decorated by the functionalized organic linker. These nets offer unprecedented selectivity towards Xe. Modelling indicates that the selectivity of these nets is tailored by synergy between the pore size and the strong electrostatics afforded by the CrO4 (2-) anions.

A high rotational barrier for physisorbed hydrogen in an fcu-metal-organic framework.

A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption in Y-FTZB, a recently reported metal-organic framework (MOF) with fcu topology, reveals that the strongest binding site in the MOF causes a high barrier to rotation on the sorbed H2. This rotational barrier for H2 is the highest yet of reported MOF materials based on physisorption.

Insights into an intriguing gas sorption mechanism in a polar metal-organic framework with open-metal sites and narrow channels.

Simulations of H2 and CO2 sorption were performed in the metal-organic framework (MOF), [Cu(Me-4py-trz-ia)]. This MOF was recently shown experimentally to exhibit high uptake for H2 and CO2 sorption and this was reproduced and elucidated through the simulations performed herein. Consistent with experiment, the theoretical isosteric heat of adsorption, Q(st), values were nearly constant across all loadings for both sorbates. The simulations revealed that sorption directly onto the open-metal sites was not observed in this MOF, ostensibly a consequence of the low partial positive charges of the Cu(2+) ions as determined through electronic structure calculations. Sorption was primarily observed between adjacent carboxylate oxygen atoms (site 1) and between nearby methyl groups (site 2) of the organic linkers. In addition, saturation of the most energetically favorable sites (site 1) is possible only after filling a nearby site (site 2) first due to the MOF topology. This suggests that the lack of dependence on loading for the Q(st) is due to the concurrent filling of sites 1 and 2, leading to an observed average Q(st) value.