Water vapour and gas induced phase transformations in an 8-fold interpenetrated diamondoid metal-organic framework.

In this work, we report the synthesis, structural characterisation and sorption properties of an 8-fold interpenetrated diamondoid (dia) metal-organic framework (MOF) that is sustained by a new extended linker ligand, [Cd(Imibz)2], X-dia-2-Cd, HImibz or 2 = 4-((4-(1H-imidazol-1-yl)phenylimino)methyl)benzoic acid. X-dia-2-Cd was found to exhibit reversible single-crystal-to-single-crystal (SC-SC) transformations between four distinct phases: an as-synthesised (from N,N-dimethylformamide) wide-pore phase, X-dia-2-Cd-α; a narrow-pore phase, X-dia-2-Cd-ß, formed upon exposure to water; a narrow-pore phase obtained by activation, X-dia-2-Cd-γ; a medium-pore CO2-loaded phase X-dia-2-Cd-δ. While the space group remained constant in the four phases, the cell volumes and calculated void space ranged from 4988.7 Å3 and 47% (X-dia-2-Cd-α), respectively, to 3200.8 Å3 and 9.1% (X-dia-2-Cd-γ), respectively. X-dia-2-Cd-γ also exhibited a water vapour-induced structural transformation to the water-loaded X-dia-2-Cd-ß phase, resulting in an S-shaped sorption isotherm. The inflection point occurred at 18% RH with negligible hysteresis on the desorption profile. Water vapour temperature-humidity swing cycling (60% RH, 300 K to 0% RH, 333 K) indicated hydrolytic stability of X-dia-2-Cd and working capacity was retained after 128 cycles of sorbent regeneration. CO2 (at 195 K) was also observed to induce a structural transformation in X-dia-2-Cd-γ and in situ PXRD studies at 1 bar of CO2, 195 K revealed the formation of X-dia-2-Cd-δ, which exhibited 31% larger unit cell volume than X-dia-2-Cd-γ.

Pillar Modularity in fsc Topology Hybrid Ultramicroporous Materials Based upon Tetra(4-pyridyl)benzene.

Hybrid ultramicroporous materials (HUMs) are porous coordination networks composed of combinations of organic and inorganic linker ligands with a pore diameter of <7 Å. Despite their benchmark gas sorption selectivity for several industrially relevant gas separations and their inherent modularity, the structural and compositional diversity of HUMs remains underexplored. In this contribution, we report a family of six HUMs (SIFSIX-22-Zn, TIFSIX-6-Zn, SNFSIX-2-Zn, GEFSIX-4-Zn, ZRFSIX-3-Zn, and TAFSEVEN-1-Zn) based on Zn metal centers and the tetratopic N-donor organic ligand tetra(4-pyridyl)benzene (tepb). The incorporation of fluorinated inorganic pillars (SiF6 2-, TiF6 2-, SnF6 2-, GeF6 2-, ZrF6 2-, and TaF7 2-, respectively) resulted in (4,6)-connected fsc topology as verified using single-crystal X-ray diffraction. Pure-component gas sorption studies with N2, CO2, C2H2, C2H4, and C2H6 revealed that the large voids and narrow pore windows common to all six HUMs can be leveraged to afford high C2H2 uptakes while retaining high ideal adsorbed solution theory (IAST) selectivities for industrially relevant gas mixtures: >10 for 1:99 C2H2/C2H4 and >5 for 1:1 C2H2/CO2. The approach taken, systematic variation of pillars with retention of structure, enables differences in selectivity to be attributed directly to the choice of the inorganic pillar. This study introduces fsc topology HUMs as a modular platform that is amenable to fine-tuning of structure and properties.

Flexible Coordination Network Exhibiting Water Vapor-Induced Reversible Switching between Closed and Open Phases.

That physisorbents can reduce the energy footprint of water vapor capture and release has attracted interest because of potential applications such as moisture harvesting, dehumidification, and heat pumps. In this context, sorbents exhibiting an S-shaped single-step water sorption isotherm are desirable, most of which are structurally rigid sorbents that undergo pore-filling at low relative humidity (RH), ideally below 30% RH. Here, we report that a new flexible one-dimensional (1D) coordination network, [Cu(HQS)(TMBP)] (H2HQS = 8-hydroxyquinoline-5-sulfonic acid and TMBP = 4,4'-trimethylenedipyridine), exhibits at least five phases: two as-synthesized open phases, α ⊃ H2O and ß âŠƒ MeOH; an activated closed phase (γ); CO2 (δ ⊃ CO2) and C2H2 (ϵ ⊃ C2H2) loaded phases. The γ phase underwent a reversible structural transformation to α ⊃ H2O with a stepped sorption profile (Type F-IV) when exposed to water vapor at <30% RH at 300 K. The hydrolytic stability of [Cu(HQS)(TMBP)] was confirmed by powder X-ray diffraction (PXRD) after immersion in boiling water for 6 months. Temperature-humidity swing cycling measurements demonstrated that working capacity is retained for >100 cycles and only mild heating (<323 K) is required for regeneration. Unexpectedly, the kinetics of loading and unloading of [Cu(HQS)(TMBP)] compares favorably with well-studied rigid water sorbents such as Al-fumarate, MOF-303, and CAU-10-H. Furthermore, a polymer composite of [Cu(HQS)(TMBP)] was prepared and its water sorption retained its stepped profile and uptake capacity over multiple cycles.

Participant Characteristics and Attendance Patterns for a Multispecialty Veterans Affairs ECHO Program 2012-2018.

Introduction: The Veteran Integrated Service Network (VISN) 20 Veterans Affairs-Extension for Community Healthcare Outcomes (VA-ECHO) program connects specialty and primary care providers (PCPs) across large geographic areas, utilizing video-teleconferencing with the intention of increasing access to care among underserved and isolated populations. No previously published work describes participation patterns of a multispecialty ECHO program. We describe the development of VISN 20 VA-ECHO program to inform the design and evaluation of ECHO programs. Methods: The participant cohort included VA-affiliated licensed health care professionals, including trainees, who attended at least one VISN 20 VA-ECHO session between April 2012 and December 2018. Participant characteristics reported include gender, clinical location, clinical specialty, discipline, and rurality. Results: Over the 6-year time frame, VISN 20 VA-ECHO offered 945 sessions in 14 clinical specialties and recorded 17,893 hours of attendance. The cohort included 1,346 participants, 74.3% of whom were female, 85.2% employed in medical centers, and 40.7% affiliated with primary care. Most participants (62.3%) attended one specialty exclusively; among all participants, 40% attended five or more sessions. Discussion: Although VA-ECHO was implemented to develop single specialty expertise among PCPs, our participant cohort represented a more diverse audience from a range of disciplines and specialties. Our experience may be valuable to other teams implementing ECHO programs. Conclusions: Through adaptability and strategies that actively promoted inclusion of a diverse audience, VISN 20 VA-ECHO expanded to include multiple clinical specialties and successfully engaged an audience across a large geographic area and beyond PCPs.

Associations of sleep duration and sleep-wake rhythm with lung parenchymal abnormalities on computed tomography: The MESA study.

Impairment of the circadian rhythm promotes lung inflammation and fibrosis in pre-clinical models. We aimed to examine whether short and/or long sleep duration and other markers of sleep-wake patterns are associated with a greater burden of lung parenchymal abnormalities on computed tomography among adults. We cross-sectionally examined associations of sleep duration captured by actigraphy with interstitial lung abnormalities (n = 1111) and high attenuation areas (n = 1416) on computed tomography scan in the Multi-Ethnic Study of Atherosclerosis at Exam 5 (2010-2013). We adjusted for potential confounders in logistic and linear regression models for interstitial lung abnormalities and high attenuation area, respectively. High attenuation area models were also adjusted for study site, lung volume imaged, radiation dose and stratified by body mass index. Secondary exposures were self-reported sleep duration, sleep fragmentation index, sleep midpoint and chronotype. The mean age of those with longer sleep duration (≥ 8 hr) was 70 years and the prevalence of interstitial lung abnormalities was 14%. Increasing actigraphy-based sleep duration among participants with ≥ 8 hr of sleep was associated with a higher adjusted odds of interstitial lung abnormalities (odds ratio of 2.66 per 1-hr increment, 95% confidence interval 1.42-4.99). Longer sleep duration and higher sleep fragmentation index were associated with greater high attenuation area on computed tomography among participants with a body mass index < 25 kg m-2 (p-value for interaction < 0.02). Self-reported sleep duration, later sleep midpoint and evening chronotype were not associated with outcomes. Actigraphy-based longer sleep duration and sleep fragmentation were associated with a greater burden of lung abnormalities on computed tomography scan.

The First Sulfate-Pillared Hybrid Ultramicroporous Material, SOFOUR-1-Zn, and Its Acetylene Capture Properties.

Hybrid ultramicroporous materials, HUMs, are comprised of metal cations linked by combinations of inorganic and organic ligands. Their modular nature makes them amenable to crystal engineering studies, which have thus far afforded four HUM platforms (as classified by the inorganic linkers). HUMs are of practical interest because of their benchmark gas separation performance for several industrial gas mixtures. We report herein design and gram-scale synthesis of the prototypal sulfate-linked HUM, the fsc topology coordination network ([Zn(tepb)(SO4 )]n ), SOFOUR-1-Zn, tepb=(tetra(4-pyridyl)benzene). Alignment of the sulfate anions enables strong binding to C2 H2 via O⋅⋅⋅HC interactions but weak CO2 binding, affording a new benchmark for the difference between C2 H2 and CO2 heats of sorption at low loading (ΔQst =24 kJ mol-1 ). Dynamic column breakthrough studies afforded fuel-grade C2 H2 from trace (1 : 99) or 1 : 1 C2 H2 /CO2 mixtures, outperforming its SiF6 2- analogue, SIFSIX-22-Zn.

The "Chemistree" of Porous Coordination Networks: Taxonomic Classification of Porous Solids to Guide Crystal Engineering Studies.

New approaches to gas/vapor storage and purification are urgently needed to address the large energy footprint, cost, and/or risk associated with existing technologies. In this context, new classes of porous physisorbents, exemplified by porous coordination networks (PCNs), have emerged. There are now >100 000 entries in the Cambridge Structural Database (CSD) metal-organic framework (MOF) subset and the rate of publication, >5000 per year, grows unabatedly. The number of PCNs makes it infeasible to test all of them for sorption performance and it is therefore timely to introduce a classification approach based upon taxonomy to supplement topological classification of PCNs. This taxonomic approach complements existing databases such as the CSD and enable the design (crystal engineering) of new families of PCNs. It also categorizes existing PCNs in a manner useful to crystal engineers. The internal consistency of the taxonomic approach is verified by case studies of several well-known PCNs whereas its utility is demonstrated upon understudied topologies and hard-to-rationalize infinite rod building blocks. Overall, taxonomic classification enables a traffic light system to direct crystal engineers towards finding a "needle in haystack," that is, a family (platform) of PCNs that is amenable to crystal engineering and systematic structure/property studies.

Agreement of sleep specialists with registered nurses' sleep study orders in supervised clinical practice.

STUDY OBJECTIVES: Incorporating registered nurses (RN-level) into obstructive sleep apnea (OSA) management decisions has the potential to augment the workforce and improve patient access, but the appropriateness of such task-shifting in typical practice is unclear. METHODS: Our medical center piloted a nurse triage program for sleep medicine referrals. Using a sleep specialist-designed decision-making tool, nurses triaged patients referred for initial sleep studies to either home sleep apnea test (HSAT) or in-laboratory polysomnography (PSG). During the first 5 months of the program, specialists reviewed all nurse triages. We compared agreement between specialists and nurses. RESULTS: Of 280 consultations triaged by nurses, nurses deferred management decisions to sleep specialists in 6.1% (n = 17) of cases. Of the remaining 263 cases, there was 88% agreement between nurses and specialists (kappa 0.80, 95% confidence interval 0.74-0.87). In the 8.8% (n = 23) of cases where supervising specialists changed sleep study type, specialists changed from HSAT to PSG in 16 cases and from PSG to HSAT in 7. The most common indication for change in sleep study type was disagreement regarding OSA pretest probability (n = 14 of 23). Specialists changed test instructions in 3.0% (n = 8) of cases, with changes either related to the use of transcutaneous carbon dioxide monitoring (n = 4) or adaptive servo-ventilation (n = 4). CONCLUSIONS: More than 80% of sleep study triages by registered nurses in a supervised setting required no sleep specialist intervention. Future research should focus on how to integrate nurses into the sleep medicine workforce in a manner that maximizes efficiency while preserving or improving patient outcomes.

[Cu(4-phenylpyridine)4(trifluoromethanesulfonate)2], a Werner complex that exhibits high selectivity for o-xylene.

[Cu(4-phenylpyridine)4(trifluoromethanesulfonate)2] is a new Werner complex that exhibits switching behaviour between non-porous (apohost) and porous (guest-loaded) phases upon exposure to o-xylene but not when exposed to other C8 isomers. High o-xylene selectivity (>6) vs. the other C8 isomers was observed from binary mixtures, only the third occurrence across all sorbent types.

Risk of Cardiovascular Disease Related to Smoking Is Greater Among Women With Sleep-Disordered Breathing.

STUDY OBJECTIVES: Although both sleep-disordered breathing (SDB) and smoking are associated with cardiovascular disease (CVD), the potential for an interactive effect on CVD risk has not been explored. Our objective was to determine if smoking-related risk for CVD rises with greater SDB severity. METHODS: Polysomnography and smoking history were obtained in 3,852 men and women in the Sleep Heart Health Study without baseline CVD. Fine-Gray proportional hazard models accounting for competing risk were used to calculate risk of incident CVD associated with SDB severity (defined by clinical cutoffs of the apnea-hypopnea index), smoking status (never, former, and current) and their interaction adjusting for potential confounders. RESULTS: Over a mean (standard deviation) follow-up period of 10.3 (3.4) years, there were 694 incident CVD events. We found a significant three-way interaction of sex, current smoking, and moderate to severe SDB (P = .039) in the adjusted proportional hazards model. In adjusted analyses, women who were current smokers with moderate to severe SDB had a hazard ratio for incident CVD of 3.5 (95% confidence interval 1.6-8.0) relative to women who were nonsmokers without SDB. No such difference in CVD risk was observed in men or women of other strata of smoking and SDB. CONCLUSIONS: In women, smoking-related risk for CVD is significantly higher among individuals with moderate to severe SDB.

Consumer Sleep Technology: An American Academy of Sleep Medicine Position Statement.

ABSTRACT: Consumer sleep technologies (CSTs) are widespread applications and devices that purport to measure and even improve sleep. Sleep clinicians may frequently encounter CST in practice and, despite lack of validation against gold standard polysomnography, familiarity with these devices has become a patient expectation. This American Academy of Sleep Medicine position statement details the disadvantages and potential benefits of CSTs and provides guidance when approaching patient-generated health data from CSTs in a clinical setting. Given the lack of validation and United States Food and Drug Administration (FDA) clearance, CSTs cannot be utilized for the diagnosis and/or treatment of sleep disorders at this time. However, CSTs may be utilized to enhance the patient-clinician interaction when presented in the context of an appropriate clinical evaluation. The ubiquitous nature of CSTs may further sleep research and practice. However, future validation, access to raw data and algorithms, and FDA oversight are needed.

Introduction to Obstructive Sleep Apnea for the Internist.

Introduction: The prevalence of sleep-disordered breathing is increasing, and there are insufficient sleep medicine specialists to meet the clinical demand of caring for these patients. One way to meet this clinical need is to train primary care and internal medicine physicians to provide some of the care. However, trainees in these specialties often receive very little training on practical aspects of the management of obstructive sleep apnea (OSA). We developed an experiential workshop to address this need at our institution. Methods: For approximately 60 internal medicine residents, we ran a 2.5-hour workshop consisting of two 20-minute didactic presentations to the whole audience and two 40-minute breakout sessions, led by eight facilitators. During the breakout sessions, the residents interacted with equipment such as positive airway pressure (PAP) devices and interfaces, reviewed sleep testing and PAP download reports, and participated in guided small-group discussions. Results: We received 40 evaluation surveys with at least partial responses. Only 50% of respondents had received prior formal instruction on PAP devices. Both subjective and objective knowledge scores improved on the postworkshop questions compared to the preworkshop questions. Trainee comments were extremely positive, indicating that they enjoyed the format of the session. Discussion: This curriculum provides an interactive educational session focused on practical aspects of OSA management relevant to primary care physicians and internists. It was well received and could be adapted to suit other time frames and other groups of learners.

Habitual Sleep Duration and All-Cause Mortality in a General Community Sample.

STUDY OBJECTIVES: The current study sought to determine whether sleep duration and change in sleep duration are associated with all-cause mortality in a community sample of middle-aged and older adults while accounting for several confounding factors including prevalent sleep-disordered breathing (SDB). METHODS: Habitual sleep duration was assessed using self-report (< 7, 7-8, ≥ 9 h/night) at the baseline and at the follow-up visits of the Sleep Heart Health Study. Techniques of survival analysis were used to relate habitual sleep duration and change in sleep duration to all-cause mortality after adjusting for covariates such as age, sex, race, body mass index, smoking history, prevalent hypertension, diabetes, cardiovascular disease, antidepressant medication use, and SDB severity. RESULTS: Compared to a sleep duration of 7-8 h/night, habitually long sleep duration (≥ 9 h/night), but not short sleep duration (< 7 h/night), was associated with all-cause mortality with an adjusted hazards ratio of 1.25 (95% confidence interval [CI]: 1.05, 1.47). Participants who progressed from short or normal sleep duration to long sleep duration had increased risk for all-cause mortality with adjusted hazard ratios of 1.75 (95% CI: 1.08, 2.78) and 1.63 (95% CI: 1.26, 2.13), respectively. Finally, a change from long to short sleep duration was also associated with all-cause mortality. CONCLUSION: Long sleep duration or a shift from long to short sleep duration are independently associated with all-cause mortality.

Associations between prescription opioid use and sleep impairment among veterans with chronic pain.

OBJECTIVE: Chronic pain is associated with impairments in sleep; however, the relationship between prescription opioid status and sleep is unclear. The primary aim of this study was to examine differences in self-reported sleep quality between groups of patients who varied based on chronic pain and prescription opioid status. DESIGN: This is a cross-sectional study with retrospective review of patient medical records. SETTING: The study was performed in a single VA medical center located in the Pacific Northwest. SUBJECTS: Participants with chronic pain and a current prescription for opioid medications (N=72), chronic pain and no opioid prescription (N=104), or who did not report current chronic pain or opioid prescription (N=91) were included. METHODS: All participants completed self-report questionnaires assessing demographic characteristics, sleep parameters, pain-related variables, and psychiatric symptoms. Data on prescription opioid use were extracted from patients' medical records. RESULTS: In unadjusted analyses, patients with chronic pain who were prescribed opioids were more likely to have sleep apnea diagnoses in their medical record and reported more impairment on sleep global score and across four sleep parameter subscales (subjective sleep quality, sleep latency, sleep disturbance, and use of sleeping medications). In linear regression analyses controlling for demographic and clinical covariates, prescription opioid status was associated with sleep latency, and opioid dose was significantly associated with sleep latency and sleep global score. CONCLUSIONS: Prescription opioid status and dose were associated with impairment in self-reported sleep. For patients with chronic pain, consideration should be given to use of nonpharmacological interventions to improve sleep.

Resistant hypertension and obstructive sleep apnea.

Hypertension (HTN) is a modifiable, highly prevalent risk factor for cardiovascular morbidity and renal dysfunction worldwide. In the United States, HTN affects one in three adults, contributes to one out of every seven deaths and to nearly half of all cardiovascular disease-related deaths. HTN is considered resistant when the blood pressure remains above goal despite lifestyle modification and administration of three antihypertensive agents of different classes including a diuretic. Large population-based studies have suggested that obstructive sleep apnea (OSA) is a risk factor for resistant HTN. The mechanism proposed is a pattern of intermittent hypoxia associated with hyperaldosteronism, increased sympathetic tone, endothelial dysfunction, and inflammation. In this review we discuss the association between OSA and resistant HTN, the physiologic mechanisms linking OSA with resistant HTN, and the effect of continuous positive airway pressure therapy (CPAP) on blood pressure in patients with resistant HTN. While the reduction in blood pressure with CPAP is usually modest in patients with OSA, a decrease of only a few mmHg in blood pressure can significantly reduce cardiovascular risk. Patients presenting to a center specializing in management of hypertension should be screened and treated for OSA as a potentially modifiable risk factor.

Obstructive sleep apnea during rapid eye movement sleep, daytime sleepiness, and quality of life in older men in Osteoporotic Fractures in Men (MrOS) Sleep Study.

STUDY OBJECTIVES: Assess the association between REM predominant obstructive sleep apnea (OSA), sleepiness, and quality of life in a community-based cohort of men ≥ 65 years-old. DESIGN INTERVENTION AND MEASUREMENTS: A cross-sectional analysis of 2,765 subjects from the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study was performed to identify subjects with an apnea hypopnea index (AHI) < 15 (n = 2,044). Subjects were divided into groups based on the AHI in REM sleep (< 5 [referent group], 5 to < 15, 15 to < 30, and ≥ 30). Daytime somnolence, sleep-related quality of life, sleep disturbance, general quality of life, depressive symptoms, and health status were quantified using Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), Pittsburgh Sleep Quality Index (PSQI), Short Form-12 (SF-12), Geriatric Depression Scale-15 (GDS), and self-perceived health status, respectively. RESULTS: Prevalence of REM-predominant OSA (AHI-REM ≥ 5) was 42.8% if OSA was defined as AHI ≥ 15 and 14.4% if OSA was defined as AHI ≥ 5. Higher AHI-REM was associated with polysomnographic indices of poorer sleep architecture (reduced total sleep time, sleep efficiency, REM sleep duration and proportion). Adjusting for age, BMI, and study site, higher AHI-REM was not associated with subjective sleep measures (ESS, FOSQ, PSQI), lower quality of life (SF-12), or greater depressive symptoms (GDS). CONCLUSIONS: In a community-based sample of older adult men ≥ 65 years-old, REM-predominant OSA was highly prevalent and was associated with objective indices of poorer sleep quality on polysomnography but not with subjective measures of daytime sleepiness or quality of life.