Effect of Air Transport Delay on Mortality in Critical Illness: A Population-Based Cohort Study.

OBJECTIVE: For critically ill patients in remote areas, we assessed the association of transport delay via fixed wing air ambulance on 30-day mortality, excluding interhospital transports. METHODS: This was a retrospective cohort analysis of all such adult transports in Manitoba, Canada, over 5.4 years. Causal mediation analysis was used, with the Acute Physiology and Chronic Health Evaluation II Acute Physiology Score at the destination intensive care unit as the mediator. The covariates were age, sex, comorbidities, socioeconomic status, and physiologic variables from the sending site. RESULTS: The primary cohort was composed of 554 patients; 113 (20.4%) died within 30 days. The total transport delay (mean ± standard deviation) was 5.1 ± 1.7 hours. Compared with no delay, the average 5-hour transport delay was associated with an odds ratio for mortality of 1.34 with a 95% confidence interval from 40% lower to 270% higher, with 60% of the influence of total travel time attributable to worsening of patients' acute physiologic status during the delay in intensive care unit admission due to transport. CONCLUSIONS: Although these findings provide insufficient evidence for an effect of fixed wing air transport delay on mortality among critically ill patients, they underscore the need for additional and larger studies on this topic.

Heterobimetallic coordination polymers based on the [Pt(SCN)4]2- and [Pt(SeCN)4]2- building blocks.

New complexes and the first coordination polymers containing [Pt(SCN)4](2-) of the type [M(L)x][Pt(SCN)4] (where L = 2,2'-bipyridine (bipy), x = 2, M = Co(II), Ni(II), Cu(II); L = ethylenediamine (en), x = 2, M = Ni(II), Cu(II); L = N,N,N',N'-tetramethylethylenediamine (tmeda), x = 1, M = Cu(II); L = 2,2';6',2″-terpyridine (terpy), x = 1, M = Mn(II), Co(II); L = 1,10-phenanthroline (phen), x = 2, M = Pb(II)) were prepared by reacting the appropriate metal-ligand cations with K2[Pt(SCN)4] and structurally characterized. [M(bipy)2Pt(SCN)4]2·2MeOH (M = Co (1), Cu (4)) consist of supramolecular tetranuclear distorted squares containing two [M(bipy)2](2+) and two [Pt(SCN)4](2+) units. [Cu(bipy)2(NCS)]2[Pt(SCN)4] (6) is a double salt of the [Pt(SCN)4](2-) anion and two [Cu(bipy)(NCS)](+) cations. [Cu(en)2Pt(SCN)4] (7, 8) are 1-D coordination polymers that are coordinated in either cis or trans fashion at the [Pt(SCN)4](2-) unit, for 7 and 8, respectively. Complexes [Cu(en)2Pt(SeCN)4] (9) and [Ni(en)2Pt(SCN)4] (10) are similar to 8 and 7, respectively, but complex 9 (prepared using ((n)Bu4N)2[Pt(SeCN)4]) also presents intermolecular Se-Se interactions which resulted in an increased dimensionality. Compounds [M(terpy)Pt(SCN)4] (M = Mn (11), Co (13)) involve 2-D sheets of [M(terpy)](2+) and [Pt(SCN)4](2-) units, whereas [Mn(terpy)2][Pt(SCN)4] (12) is a double salt of one [Mn(terpy)2](2+) unit and one [Pt(SCN)4](2-). [Cu(tmeda)Pt(SCN)4] (14) contains a five-coordinate Cu(2+) metal center coordinated to one tmeda ligand and three different [Pt(SCN)4](2-) units, resulting in 2-D sheets. [Pb(phen)2Pt(SCN)4] (15) contains an 8-coordinate Pb(2+) metal center coordinated to two phen ligands and four [Pt(SCN)4](2-), generating a 3-D network in the solid state. Structural correlations were established between the ancillary ligand, the choice of metal, the structure of the [Pt(SCN)4](2-) building block, and the resulting dimensionality of the coordination polymers.

Magnetic properties of isostructural M(H2O)4[Au(CN)4]2-based coordination polymers (M = Mn, Co, Ni, Cu, Zn) by SQUID and µSR studies.

A series of isomorphous M(H(2)O)(4)[Au(CN)(4)](2)·4H(2)O (M = Mn, Co, Ni, Zn; Cu is similar) coordination polymers was synthesized from the reaction of M(II) with KAu(CN)(4); they consist of octahedrally coordinated metal centres with four equatorial water molecules and trans-axial N-cyano ligands from [Au(CN)(4)](-) moieties, generating a linear 1-D chain of M(H(2)O)(4)[Au(CN)(4)]-units. An additional interstitial [Au(CN)(4)](-) unit forms AuN and hydrogen bonds with adjacent chains. The Cu(II) system readily loses water to yield Cu[Au(CN)(4)](2)(H(2)O)(4), which was not structurally characterized. The magnetic properties of these polymers were investigated by a combination of SQUID magnetometry and zero-field muon spin relaxation (ZF-µSR). Only weak antiferromagnetic interactions along the chains are mediated by the [Au(CN)(4)]-units, but the ZF-µSR data indicates that interchain interactions yield a phase transition to a magnetically ordered state for Cu[Au(CN)(4)](2)(H(2)O)(4) below 0.6 K, while for M(H(2)O)(4)[Au(CN)(4)](2)·4H(2)O (M = Co), depopulation of zero-field split Kramer's doublets to an effective "S = 1/2" ground state yields a transition to a spin-frozen magnetic state below 0.26 K. On the other hand, only a simple slowing-down of spins above 0.02 K is observed for the more weakly zero-field split M(H(2)O)(4)[Au(CN)(4)](2)·4H(2)O (M = Mn, Ni) complexes.

Aggregation of [Au(CN)4]- anions: examination by crystallography and 15N CP-MAS NMR and the structural factors influencing intermolecular Au···N interactions.

To investigate the factors influencing the formation of intermolecular Au···NC interactions between [Au(CN)(4)](-) units, a series of [cation](n+)[Au(CN)(4)](n) double salts was synthesized, structurally characterized and probed by IR and (15)N{(1)H} CP-MAS NMR spectroscopy. Thus, [(n)Bu(4)N][Au(CN)(4)], [AsPh(4)][Au(CN)(4)], [N(PPh(3))(2)][Au(CN)(4)], [Co(1,10-phenanthroline)(3)][Au(CN)(4)](2), and [Mn(2,2';6',2''-terpyridine)(2)][Au(CN)(4)](2) show [Au(CN)(4)](-) anions that are well-separated from one another; no Au-Au or Au···NC interactions are present. trans-[Co(1,2-diaminoethane)(2)Cl(2)][Au(CN)(4)] forms a supramolecular structure, where trans-[Co(en)(2)Cl(2)](+) and [Au(CN)(4)](-) ions are found in separate layers connected by Au-CN···H-N hydrogen-bonding; weak Au···NC coordinate bonds complete octahedral Au(III) centers, and support a 2-D (4,4) network motif of [Au(CN)(4)](-)-units. A similar structure-type is formed by [Co(NH(3))(6)][Au(CN)(4)](3)·(H(2)O)(4). In [Ni(1,2-diaminoethane)(3)][Au(CN)(4)](2), intermolecular Au···NC interactions facilitate formation of 1-D chains of [Au(CN)(4)](-) anions in the supramolecular structure, which are separated from one another by [Ni(en)(3)](2+) cations. In [1,4-diazabicyclo[2.2.2]octane-H][Au(CN)(4)], the monoprotonated amine cation forms a hydrogen-bond to the [Au(CN)(4)](-) unit on one side, while coordinating to the axial sites of the gold(III) center through the unprotonated amine on the other, thereby generating a 2-D (4,4) net of cations and anions; an additional, uncoordinated [Au(CN)(4)](-)-unit lies in the central space of each grid. This body of structural data indicates that cations with hydrogen-bonding groups can induce intermolecular Au···NC interactions, while the cationic charge, shape, size, and aromaticity have little effect. While the ν(CN) values are poor indicators of the presence or absence of N-cyano bridging between [Au(CN)(4)](-)-units (partly because of the very low intensity of the observed bands), (15)N{(1)H} CP-MAS NMR reveals well-defined, ordered cyanide groups in the six diamagnetic compounds with chemical shifts between 250 and 275 ppm; the resonances between 260 and 275 ppm can be assigned to C-bound terminal ligands, while those subject to CN···H-N bonding resonate lower, around 250-257 ppm. The (15)N chemical shift also correlates with the intermolecular Au···N distances: the shortest Au-N distances also shift the (15)N peak to lower frequency. This provides a real, spectroscopically measurable electronic effect associated with the crystallographic observation of intermolecular Au···NC interactions, thereby lending support for their viability.

Changes in electronic properties of polymeric one-dimensional {[M(CN)2]-}n (M = Au, Ag) chains due to neighboring closed-shell Zn(II) or open-shell Cu(II) ions.

A series of d(10) dicyanometallate polymeric compounds were studied by electronic spectroscopy and density functional theory (DFT) calculations. In these materials, the negatively charged one-dimensional (1D) polymeric chains are linked together by [M(en)(2)](2+) (M = Cu(II) and Zn(II); en = ethylenediamine). More than innocent building blocks, the [M(en)(2)](2+) units offer a possible synthetic way to modify electronic properties of the materials. Through its low energy d-d excited state, the d(9) copper(II) ions offer deactivation pathways for the normally emissive dicyanometallate polymer. Deactivation was shown to be specific to the excited state energy.

The use of polarizable [AuX2(CN)2]- (X = Br, I) building blocks toward the formation of birefringent coordination polymers.

The [(n)Bu(4)N][AuX(2)(CN)(2)] (X = Br, I) salts were synthesized and structurally characterized. Both feature square-planar [AuX(2)(CN)(2)](-) anions, with trans cyano and halo ligands, which aggregate via halogen-halogen interactions. The aggregation of [AuX(2)(CN)(2)](-) units results in the parallel alignment of all of the Br-Au-Br moieties in the anions along the [110] and [110] directions. Two crystal habits of [(n)Bu(4)N][AuBr(2)(CN)(2)] were grown: with (110) and (001) as the primary faces. The birefringence in the (110) plane was found to be Δn = 0.051(4) and was <0.03 in the (001) plane. Using the [AuBr(2)(CN)(2)](-) unit, [M(phen)(2)][AuBr(2)(CN)(2)](2) (M = Fe, Ni), [Ni(terpy)(2)][AuBr(2)(CN)(2)](2), [Fe(terpy)(2)][AuBr(2)(CN)(2)][ClO(4)], and [Cu(phen)(2)(NO(3))][AuBr(2)(CN)(2)] (phen = 1,10-phenanthroline, terpy = 2,2';6',2''-terpyridine) were synthesized and structurally characterized: they formed ionic structures with coordinatively saturated metal cations and structurally aligning Br···Br interactions between the [AuBr(2)(CN)(2)](-) anions. A molecular complex, Cu(terpy)[AuBr(2)(CN)(2)](2), was prepared, as well as the coordination polymer, [Ni(en)(2)(AuBr(2)(CN)(2))][AuBr(2)(CN)(2)]·MeOH (en = ethylenediamine). The structure consists of layers of chains of Ni(en)(2)(AuBr(2)(CN)(2))(+) units and chains of unbound [AuBr(2)(CN)(2)](-) units formed via Br···Br interactions; a Δn = 0.131(3) was measured. The Δn values were related to the supramolecular structures in terms of the relative intermolecular alignment of Br-Au-Br and NC-Au-CN bonds. These measurements both demonstrate the utility of the Au-Br bonds in enhancing birefringence and show that the contribution of the M-CN units to the overall birefringence of cyanometallate coordinations polymers is non-negligible.