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1.
Science ; 366(6462): 241-246, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31601769

RESUMO

Purification of ethylene (C2H4), the largest-volume product of the chemical industry, currently involves energy-intensive processes such as chemisorption (CO2 removal), catalytic hydrogenation (C2H2 conversion), and cryogenic distillation (C2H6 separation). Although advanced physisorbent or membrane separation could lower the energy input, one-step removal of multiple impurities, especially trace impurities, has not been feasible. We introduce a synergistic sorbent separation method for the one-step production of polymer-grade C2H4 from ternary (C2H2/C2H6/C2H4) or quaternary (CO2/C2H2/C2H6/C2H4) gas mixtures with a series of physisorbents in a packed-bed geometry. We synthesized ultraselective microporous metal-organic materials that were readily regenerated, including one that was selective for C2H6 over CO2, C2H2, and C2H4.

2.
J Relig Health ; 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31392626

RESUMO

Spirituality, an established resource within rural America, serves as an important coping mechanism for crises of chronic illness. We examined the effects of spirituality on chronic kidney disease (CKD) maintenance in the rural community of Robeson County, North Carolina. We conducted nine focus group discussions and 16 interviews involving 80 diverse key informants impacted by CKD. As disenfranchised patients, they locally engaged in spirituality which mobilized personal and social resources and elicited support from a transcendent authority. Our participants developed a heuristic and aesthetic understanding of disease, built resilience and self-care skills, and improved overall coping and survival.

3.
ACS Appl Mater Interfaces ; 11(26): 23192-23197, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184107

RESUMO

Inspired by the structure of carbonic anhydrase, we developed a robust ultramicroporous lanthanide metal-organic framework (MOF) platform (NKMOF-3-Ln), which possesses a porous pocket to selectively bind with CO2 at ambient conditions. Notably, CO2 molecules can be precisely observed in the single-crystal structure of NKMOF-3-Ln. Highly ordered CO2 molecules can strongly interact with the framework via electrostatic interaction of nitrates. We found that the CO2 adsorption capacity and binding energy were gradually enhanced as lanthanide contraction. The strong CO2 binding affinity endows NKMOF-3-Ln with excellent CO2 separation performance, which is verified by experimental breakthrough results. Moreover, because of the specific binding affinity of CO2, NKMOF-3-Eu showed a fluorescence response to CO2.

4.
BMC Cardiovasc Disord ; 19(1): 99, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035921

RESUMO

BACKGROUND: The cornerstone of effective management in heart failure (HF) is the ability to self-care. Aims include i) To determine factors influencing self-care in HF patients with cognitive impairment (CI) and ii) to determine the influence of cognitive domains on self-care in patients with HF and CI. METHODS: MEDLINE, CINAHL, EMBASE, EBSCOHost, PsychINFO, ProQuest Research Library, Health Technology Assessment Database, The Cochrane Library, Web of Science and Scopus databases were systematically searched. Original research describing the relationship between cognition and HF self-care in community-dwelling older persons with dementia/CI in English, published in a peer-reviewed journal from 1stJanuary(2000)-22ndMarch(2016) was identified. Study and population characteristics, data sources, self-care processes, methods of cognitive assessment, cognitive domains affected, study outcomes, impact of impairment, and other risk factors of self-care impairment were abstracted by two reviewers. RESULTS: Of 10,688 studies identified, 14 met the inclusion criteria. Patients with HF and CI ranged from 14 to 73%. Where reported, self-care maintenance adequacy ranged from 50 to 61%; self-care management adequacy ranged from 14 to 36% and self-care confidence adequacy ranged from 0 to 44% on the Self-care of Heart Failure Index (SCHFI). All but one study predicted poor self-care ability according to poor outcome on cognitive testing. Additionally, specific cognitive domain deficits impaired self-care. Subjects with lower cognitive scores were less likely to seek assistance while subjects with depression had poor self-care abilities. CONCLUSIONS: Clinicians must consider the type and severity of impairments in cognitive domains to tailor management. Awareness of depression, self-confidence and support access may modulate self-care ability.

5.
Angew Chem Int Ed Engl ; 58(30): 10209-10214, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31059186

RESUMO

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.

6.
Angew Chem Int Ed Engl ; 58(30): 10138-10141, 2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31115966

RESUMO

As a major greenhouse gas, methane, which is directly vented from the coal-mine to the atmosphere, has not yet drawn sufficient attention. To address this problem, we report a methane nano-trap that features oppositely adjacent open metal sites and dense alkyl groups in a metal-organic framework (MOF). The alkyl MOF-based methane nano-trap exhibits a record-high methane uptake and CH4 /N2 selectivity at 298 K and 1 bar. The methane molecules trapped within the alkyl MOF were crystalographically identified by single-crystal X-ray diffraction experiments, which in combination with molecular simulation studies unveiled the methane adsorption mechanism within the MOF-based nano-trap. The IAST calculations and the breakthrough experiments revealed that the alkyl MOF-based methane nano-trap is a new benchmark for CH4 /N2 separation, thereby providing a new perspective for capturing methane from coal-mine methane to recover fuel and reduce greenhouse gas emissions.

7.
BMJ Open ; 9(5): e026118, 2019 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-31110093

RESUMO

OBJECTIVES: To describe the characteristics of deaths reported to the Coroners Court of Victoria (CCOV) during Victoria's last heatwave (14-17 January 2014) and subsequent 4 days (18-21 January) using medicolegal data obtained from both the police investigation report and the pathologist's report. DESIGN, SETTING AND PARTICIPANTS: A single-jurisdiction population-based retrospective analysis of consecutive heat-related deaths (HRDs) reported to the CCOV between 14 and 21 January 2014 with a historical comparison group. MAIN OUTCOME MEASURES: Descriptive statistics were used to summarise case demographics, causes of death and the types of investigations performed. The cases from 2014 were subgrouped into HRD and non-HRD. RESULTS: Of the 222 cases during the study period in 2014, 94 (42.3%) were HRDs and 128 (57.7%) were non-HRDs. HRDs were significantly older than non-HRDs (70.5 years: SD=13.8 vs 61.0 years: SD=22.4, t(220)=3.60, p<0.001, 95% CI 4.3 to 14.6). The most common primary cause of death in HRDs was circulatory system disease (n=57, 60.6%), which was significantly higher when compared with non-HRDs (n=39, 30.5%; χ2=20.1, p<0.001, OR 3.5, 95% CI 2.0 to 6.2). HRDs required significantly greater toxicology investigation (89.4% (n=84) vs 71.9% (n=92); χ2=10.9, p<0.001, OR 3.3, 95% CI 1.54 to 7.03) and greater vitreous biochemistry testing (40.4% (n=38) vs 16.4% (n=21); χ2=16.0, p<0.001, OR 3.5, 95% CI 1.9 to 6.5). CONCLUSIONS: A heatwave places a significant burden on death investigation services. The inclusion of additional laboratory tests and more detailed circumstantial information are essential if the factors that contribute to HRDs are to be identified.

8.
Chem Commun (Camb) ; 55(22): 3219-3222, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30806425

RESUMO

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.

9.
Artigo em Inglês | MEDLINE | ID: mdl-30628910

RESUMO

Although people with dementia are prone to the risk of fire and burn injuries, the relationship between fatal thermal injuries and dementia has not been investigated. We examined coronial files in the state of Victoria, Australia between July 1, 2000 and December 31, 2014, for unintentional thermal injury causing deaths of community dwelling people, aged 65 years and older to identify those with dementia. Mortality for Victorian populations with and without dementia was calculated using direct age standardization. In total, 105 deaths were identified of which 18 (17%) had dementia. Mortality was more than 3-fold greater for people with dementia (3.0 vs. 0.8 per 100,000 person-years) and they more often lived with others when the injury occurred (56%, n=10 vs. 29% n=25, P=0.028). Our results suggest that older people with dementia are at greater risk of death through thermal injury. Further research should consider investigating a larger population through combining databases across multiple jurisdictions.

10.
Angew Chem Int Ed Engl ; 57(34): 10971-10975, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-29972279

RESUMO

Highly selective separation and/or purification of acetylene from various gas mixtures is a relevant and difficult challenge that currently requires costly and energy-intensive chemisorption processes. Two ultramicroporous metal-organic framework physisorbents, NKMOF-1-M (M=Cu or Ni), offer high hydrolytic stability and benchmark selectivity towards acetylene versus several gases at ambient temperature. The performance of NKMOF-1-M is attributed to their exceptional acetylene binding affinity as revealed by modelling and several experimental studies: in situ single-crystal X-ray diffraction, FTIR, and gas mixture breakthrough tests. NKMOF-1-M exhibit better low-pressure uptake than existing physisorbents and possesses the highest selectivities yet reported for C2 H2 /CO2 and C2 H2 /CH4 . The performance of NKMOF-1-M is not driven by the same mechanism as current benchmark physisorbents that rely on pore walls lined by inorganic anions.

11.
Sci Adv ; 4(4): eaaq1636, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29719864

RESUMO

Shape-memory effects are quite well-studied in general, but there is only one reported example in the context of porous materials. We report the second example of a porous coordination network that exhibits a sorbate-induced shape-memory effect and the first in which multiple sorbates, N2, CO2 and CO promote this effect. The material, a new threefold interpenetrated pcu network, [Zn2(4,4'-biphenyldicarboxylate)2(1,4-bis(4-pyridyl)benzene)]n (X-pcu-3-Zn-3i), exhibits three distinct phases: the as-synthesized α phase; a denser-activated ß phase; and a shape-memory γ phase, which is intermediate in density between the α and ß phases. The γ phase is kinetically stable over multiple adsorption/desorption cycles and only reverts to the ß phase when heated at >400 K under vacuum. The α phase can be regenerated by soaking the γ phase in N,N'-dimethylformamide. Single-crystal x-ray crystallography studies of all three phases provide insight into the shape-memory phenomenon by revealing the nature of interactions between interpenetrated networks. The ß and γ phases were further investigated by in situ coincidence powder x-ray diffraction, and their sorption isotherms were replicated by density functional theory calculations. Analysis of the structural information concerning the three phases of X-pcu-3-Zn-3i enabled us to understand structure-function relationships and propose crystal engineering principles for the design of more examples of shape-memory porous materials.

12.
Angew Chem Int Ed Engl ; 57(20): 5684-5689, 2018 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-29575465

RESUMO

Herein, we report that a new flexible coordination network, NiL2 (L=4-(4-pyridyl)-biphenyl-4-carboxylic acid), with diamondoid topology switches between non-porous (closed) and several porous (open) phases at specific CO2 and CH4 pressures. These phases are manifested by multi-step low-pressure isotherms for CO2 or a single-step high-pressure isotherm for CH4 . The potential methane working capacity of NiL2 approaches that of compressed natural gas but at much lower pressures. The guest-induced phase transitions of NiL2 were studied by single-crystal XRD, in situ variable pressure powder XRD, synchrotron powder XRD, pressure-gradient differential scanning calorimetry (P-DSC), and molecular modeling. The detailed structural information provides insight into the extreme flexibility of NiL2 . Specifically, the extended linker ligand, L, undergoes ligand contortion and interactions between interpenetrated networks or sorbate-sorbent interactions enable the observed switching.

13.
Chem Commun (Camb) ; 54(28): 3488-3491, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29561019

RESUMO

Phases of a 2-fold pcu hybrid ultramicroporous material (HUM), SIFSIX-14-Cu-i, exhibiting 99%, 93%, 89%, and 70% partial interpenetration have been obtained. 1 : 99 C2H2/C2H4 gas separation studies reveal that as the proportion of interpenetrated component decreases, so does the separation performance.

14.
Angew Chem Int Ed Engl ; 57(13): 3332-3336, 2018 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-29377460

RESUMO

Removal of CO2 from CO gas mixtures is a necessary but challenging step during production of ultra-pure CO as processed from either steam reforming of hydrocarbons or CO2 reduction. Herein, two hybrid ultramicroporous materials (HUMs), SIFSIX-3-Ni and TIFSIX-2-Cu-i, which are known to exhibit strong affinity for CO2 , were examined with respect to their performance for this separation. The single-gas CO sorption isotherms of these HUMs were measured for the first time and are indicative of weak affinity for CO and benchmark CO2 /CO selectivity (>4000 for SIFSIX-3-Ni). This prompted us to conduct dynamic breakthrough experiments and compare performance with other porous materials. Ultra-pure CO (99.99 %) was thereby obtained from CO gas mixtures containing both trace (1 %) and bulk (50 %) levels of CO2 in a one-step physisorption-based separation process.

15.
Phys Chem Chem Phys ; 20(3): 1761-1777, 2018 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-29270586

RESUMO

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.

16.
Phys Chem Chem Phys ; 19(43): 29204-29221, 2017 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-29067398

RESUMO

Simulations of CO2 and H2 sorption were performed in an rht-metal-organic framework (MOF) that consists of Cu2+ ions coordinated to 5,5',5''-(4,4',4''-(benzene-1,3,5-triyl)tris(1H-1,2,3-triazole-4,1-diyl))triisophthalate (BTTI) linkers; it is referred to as Cu-BTTI herein. This MOF was previously synthesized and reported by three different experimental groups [Zhao et al., Sci. Rep., 2013, 3, 1149; Schröder et al., Chem. Sci., 2013, 4, 1731-1736; Hupp et al., Energy Environ. Sci., 2013, 6, 1158-1163]. This MOF is notable for the presence of open-metal sites and nitrogen-rich regions through the copper paddlewheel ([Cu2(O2CR)4]) clusters and 1,2,3-triazole groups, respectively, which allows this material to display remarkable CO2 and H2 sorption properties. All three groups report distinct experimental and theoretical gas sorption results for the MOF. In contrast to the force fields utilized in the aforementioned studies, our simulations include explicit many-body polarization interactions, which was important to reproduce sorption onto the open-metal sites. Simulations using polarizable potentials for the MOF and sorbates generated sorption isotherms and isosteric heat of adsorption (Qst) values that are outstanding agreement with the corresponding experimental data for all three groups; this is in contrast to the theoretical results presented in the respective original references. The simulations carried out in the previous studies often looked reasonable but they missed a key feature of the sorption process that lead to unreliable results. Analysis of the radial distribution function (g(r)) about the open-metal sites and examination of the modeled structure reveal that the CO2 and H2 molecules prefer to sorb onto two unique types of Cu2+ ions that exhibit the highest partial positive charges. Sorption was also observed within the corners of the truncated tetrahedral (T-Td) cages and onto the 1,2,3-triazole groups of the linkers for both sorbates. Overall, this study demonstrates how utilizing a classical polarizable force field led to the reproduction of experimental observables and allowed for an accurate description of the sorption mechanism in this MOF that is an important member of the rht-MOF family.

17.
Chem Commun (Camb) ; 53(84): 11592-11595, 2017 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-28990607

RESUMO

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 C2H2 separation from C2H2/C2H4 gas mixtures.

18.
Phys Chem Chem Phys ; 19(28): 18587-18602, 2017 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-28686253

RESUMO

Simulations of CO2 and H2 sorption were performed in UTSA-20, a metal-organic framework (MOF) having zyg topology and composed of Cu2+ ions coordinated to 3,3',3'',5,5',5''-benzene-1,3,5-triyl-hexabenzoate (BHB) linkers. Previous experimental studies have shown that this MOF displays remarkable CO2 sorption properties and exhibits one of the highest gravimetric H2 uptakes at 77 K/1.0 atm (2.9 wt%) [Z. Guo, et al. Angew. Chem., Int. Ed., 2011, 50, 3178-3181]. For both sorbates, the simulations were executed with the inclusion of explicit many-body polarization interactions, which was necessary to reproduce sorption onto the open-metal sites. Non-polarizable potentials were also utilized for simulations of CO2 sorption as a control. The simulated excess sorption isotherms for both CO2 and H2 are in very good agreement with the corresponding experimental data over a wide range of temperatures and pressures, thus demonstrating the accuracy and predictive power of the polarizable potentials used herein. The theoretical isosteric heat of adsorption (Qst) values are also in good agreement with the newly reported experimental Qst values for the respective sorbates in UTSA-20. Sorption onto the more positively charged Cu2+ ion of the [Cu2(O2CR)4] cluster was observed for both CO2 and H2. However, a binding site with energetics comparable to that for an open-metal site was also discovered for both sorbates. A radial distribution function (g(r)) analysis about the preferential Cu2+ ions for CO2 and H2 revealed that both sorbates display different trends for the relative occupancy about such sites upon increasing/decreasing the pressure in the MOF. Overall, this study provides insights into the CO2 and H2 sorption mechanisms in this MOF containing open-metal sites and small pore sizes for the first time through a classical polarizable force field.

19.
Angew Chem Int Ed Engl ; 56(38): 11426-11430, 2017 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-28707307

RESUMO

We present a crystal engineering strategy to fine tune the pore chemistry and CH4 -storage performance of a family of isomorphic MOFs based upon PCN-14. These MOFs exhibit similar pore size, pore surface, and surface area (around 3000 m2 g-1 ) and were prepared with the goal to enhance CH4 working capacity. [Cu2 (L2)(H2 O)2 ]n (NJU-Bai 41: NJU-Bai for Nanjing University Bai's group), [Cu2 (L3)(H2 O)2 ]n (NJU-Bai 42), and [Cu2 (L4)(DMF)2 ]n (NJU-Bai 43) were prepared and we observed that the CH4 volumetric working capacity and volumetric uptake values are influenced by subtle changes in structure and chemistry. In particular, the CH4 working capacity of NJU-Bai 43 reaches 198 cm3 (STP: 273.15 K, 1 atm) cm-3 at 298 K and 65 bar, which is amongst the highest reported for MOFs under these conditions and is much higher than the corresponding value for PCN-14 (157 cm3 (STP) cm-3 ).

20.
Med J Aust ; 206(10): 442-447, 2017 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-28566062

RESUMO

OBJECTIVES: To conduct a descriptive epidemiological analysis of external cause deaths (premature, usually injury-related, and potentially preventable) of nursing home residents in Australia. DESIGN: Retrospective study of a cohort of nursing home residents, using coronial data routinely recorded by the National Coronial Information System. SETTING AND PARTICIPANTS: Residents of accredited Australian nursing homes, whose deaths were reported to coroners between 1 July 2000 and 30 June 2013, and determined to have resulted from external causes. MAIN OUTCOME MEASURES: Causes of death, analysed by sex and age group, and by location of incidents leading to death and location of death. Rates of death were estimated on the basis of Australian Bureau of Statistics population and Australian Institute of Health and Welfare nursing home data. RESULTS: Of 21672 deaths of nursing home residents, 3289 (15.2%) resulted from external causes. The most frequent mechanisms of death were falls (2679 cases, 81.5%), choking (261 cases, 7.9%) and suicide (146 cases, 4.4%). The incidents leading to death usually occurred in the nursing home (95.8%), but the deaths more frequently occurred outside the nursing home (67.1%). The annual number of external cause deaths in nursing homes increased during the study period (from 1.2 per 1000 admissions in 2001-02 to 5.3 per 1000 admissions in 2011-12). CONCLUSION: The incidence of premature and potentially preventable deaths of nursing home residents has increased over the past decade. A national policy framework is needed to reduce the incidence of premature deaths among Australians living in nursing homes.


Assuntos
Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Hospitalização/estatística & dados numéricos , Mortalidade Prematura/tendências , Casas de Saúde/estatística & dados numéricos , Acidentes por Quedas/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Obstrução das Vias Respiratórias/epidemiologia , Austrália/epidemiologia , Causas de Morte , Médicos Legistas , Estudos Epidemiológicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Suicídio/estatística & dados numéricos
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