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1.
Heliyon ; 7(9): e07905, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34514179

ABSTRACT

In this work, we employ a data-fitted compartmental model to visualize the progression and behavioral response to COVID-19 that match provincial case data in Ontario, Canada from February to June of 2020. This is a "rear-view mirror" glance at how this region has responded to the 1st wave of the pandemic, when testing was sparse and NPI measures were the only remedy to stave off the pandemic. We use an SEIR-type model with age-stratified subpopulations and their corresponding contact rates and asymptomatic rates in order to incorporate heterogeneity in our population and to calibrate the time-dependent reduction of Ontario-specific contact rates to reflect intervention measures in the province throughout lockdown and various stages of social-distancing measures. Cellphone mobility data taken from Google, combining several mobility categories, allows us to investigate the effects of mobility reduction and other NPI measures on the evolution of the pandemic. Of interest here is our quantification of the effectiveness of Ontario's response to COVID-19 before and after provincial measures and our conclusion that the sharp decrease in mobility has had a pronounced effect in the first few weeks of the lockdown, while its effect is harder to infer once other NPI measures took hold.

2.
ACS Appl Mater Interfaces ; 13(1): 1301-1313, 2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33351602

ABSTRACT

The successful covalent attachment, via copper(I)-catalyzed azide alkyne cycloaddition (CuAAC), of alkyne-functionalized nickel(II) and copper(II) macrocyclic complexes onto azide (N3)-functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) films on ITO-coated glass electrodes is reported. To investigate the surface attachment of the selected metal complexes, which are analogues of the cobalt-based complex previously reported to be a molecular catalyst for hydrogen evolution, first, three different PEDOT films were formed by electropolymerization of pure PEDOT or pure N3-PEDOT, and last, 1:2N3-PEDOT:PEDOT were formed by co-polymerizing a 1:4 mixture of N3-EDOT:EDOT monomers. The successful surface immobilization of the complexes on the latter two azide-functionalized films, by CuAAC, was confirmed by X-ray photoelectron spectroscopy (XPS) and electrochemistry as well as by UV-vis-NIR and resonance Raman spectroelectrochemistry. The ratio between the N3 groups, and hence, the number of surface-attached metal complexes after CuAAC functionalization, in pristine N3-PEDOT versus 1:2N3-PEDOT:PEDOT is expected to be 3:1 and seen to be 2.86:1 with a calculated surface coverage of 3.28 ± 1.04 and 1.15 ± 0.09 nmol/cm2, respectively. The conversion, to the metal complex attached films, was lower for the N3-PEDOT films (Ni 74%, Cu 76%) than for the copolymer 1:2N3-PEDOT:PEDOT films (Ni 83%, Cu 91%) due to the former being more sterically congested. The Raman and UV-vis-NIR results were simulated using density functional theory (DFT) and time-dependent DFT (TD-DFT), respectively, and showed good agreement with the experimental data. Importantly, the spectroelectrochemical behavior of both anchored metal complexes is analogous to that of the free metal complexes in solution. This proves that PEDOT films are promising conducting scaffolds for the covalent immobilization of metal complexes, as the existing electrochromic features of the complexes are preserved on immobilization, which is important for applications in electrocatalytic proton and carbon dioxide reduction, optoelectronics, and sensing.

3.
Dalton Trans ; 48(33): 12755-12756, 2019 Sep 07.
Article in English | MEDLINE | ID: mdl-31396603

ABSTRACT

Correction for 'Substituents drive ligand rearrangements, giving dinuclear rather than mononuclear complexes, and tune CoII/III redox potential' by Fabrice N. H. Karabulut et al., Dalton Trans., 2018, 47, 11749-11759, DOI: .

4.
Dalton Trans ; 48(41): 15435-15444, 2019 Oct 22.
Article in English | MEDLINE | ID: mdl-31140505

ABSTRACT

Four new, symmetrical, bis-bidentate ditopic Rdpt-type, Rat (R azine-triazole), ligands have been prepared, Lnpym-meta/para (n = 2 or 4), which contain bidentate n-pyrimidine/triazole binding pockets connected through an appropriate aromatic spacer, meta/para-phenyl, to enable assembly into dinuclear helicates or tetranuclear tetrahedral cages, respectively. The 3 : 2 self assembly reactions of each Lnpym-meta/para ligand with iron(ii) tetrafluoroborate gave the desired complexes, as shown by X-ray crystal structure determinations of the pair of helicates [FeII2(Lnpym-meta)3(BF4)4]·6CH3CN, with n = 2 (1·6CH3CN) or 4 (2·6CH3CN), and the pair of Td cages [FeII4(Lnpym-para)6(BF4)8]·xsolvent, with n = 2 (3·xsolvent) or 4 (4·xsolvent). Reversible FeII/III processes at Em = 0.95 ± 0.05 V vs. 0.01 M AgNO3/Ag in MeCN are a feature of 1-4, with little variation in the redox potential as a function of nuclearity, architecture or choice of n-pyrimidine isomer. In all four complexes the iron(ii) centres are low spin, despite having employed the weakest field diazines, the 2- and 4-pyrimidines, in these ditopic Rat ligands. Nevertheless this is an exciting proof of principle that Rdpt-type ligands (previously used to generate about 50 spin crossover-active complexes) can be extended into ditopic forms that are suitable for supramolecular assembly of helicates and cages.

5.
Inorg Chem ; 58(9): 5543-5554, 2019 May 06.
Article in English | MEDLINE | ID: mdl-30978007

ABSTRACT

The self-assembly of macrocyclic tetranuclear 3d-4f single-molecule magnet (SMM) building blocks, [CuII3TbIII(LPr)(NO3)2(H2O)]NO3 (1), with K3[MIII(CN)6] linkers, where M = Fe, Cr, or Co, results in a range of discrete (monomer and dimer) and one-dimensional (1D) chain (coordination polymer) supramolecular architectures, which have been structurally and magnetically characterized. The outcome of reactions of 1 with an excess of K3[Fe(CN)6] has been probed in detail. It was found to be dependent on several factors, resulting in five distinctly different compounds, all of which have the same 1:1 ratio of [Cu3Tb(LPr)]3+ to [Fe(CN)6]3-, but which differ in structural type, solvent content, and magnetic behavior. Three are discrete complexes: monomeric {[Cu3Tb(LPr)(H2O)5][Fe(CN)6]·(H2O)3·(MeCN)]} (2) and [Cu3Tb(LPr)Fe(CN)6(H2O)4(MeCN)]·(H2O)2·(MeCN) (3) plus dimeric {[Cu3Tb(LPr)Fe(CN)6(H2O)4]·(H2O)6.75}2 (4), while two are 1D chains (coordination polymers): {[Cu3Tb(LPr) cis-Fe(CN)6(H2O)3(MeOH)]·(H2O)3.75·(MeOH)0.75} n (5) and {[Cu3Tb(LPr) trans-Fe(CN)6(H2O)4]·(H2O)5·(DMF)5]} n (6). When K3[Cr(CN)6] or K3[Co(CN)6] are used in place of K3[Fe(CN)6], a discrete dimer {[Cu3Tb(LPr)Cr(CN)6(H2O)4]·(H2O)2.75}2 (7) and a 1D chain coordination polymer {[Cu3Tb(LPr)Co(CN)6(H2O)3(MeOH)]·(H2O)4·(MeOH)} n (8) are obtained, respectively, which are isomorphous with 4 and 5, respectively. Magnetic studies reveal the paramagnetism of these compounds down to 1.8 K, except for 7, which displays an ordered antiferromagnetic ground state with metamagnetic behavior. The 1D-coordination polymers (5, 6, and 8) do not exhibit single-chain magnet properties, because of the very weak interbuilding block magnetic interactions. For chain 8, below 2.8 K, a clear nonzero out-of-phase signal is seen, similar to that seen for the building block 1, so the magnetism of 8 is governed by that of these SMM building blocks (1).

6.
Inorg Chem ; 57(11): 6266-6282, 2018 Jun 04.
Article in English | MEDLINE | ID: mdl-29767514

ABSTRACT

Two isomeric pyrimidine-based Rdpt-type triazole ligands were made: 4-(4-methylphenyl)-3-(2-pyrimidyl)-5-phenyl-4 H-1,2,4-triazole (L2pyrimidine) and 4-(4-methylphenyl)-3-(4-pyrimidyl)-5-phenyl-4 H-1,2,4-triazole (L4pyrimidine). When reacted with [FeII(pyridine)4(NCE)2], where E = S, Se, or BH3, two families of mononuclear iron(II) complexes are obtained, including six solvatomorphs, giving a total of 12 compounds: [FeII(L2pyrimidine)2(NCS)2] (1), [FeII(L2pyrimidine)2(NCSe)2] (2), 2·1.5H2O, [FeII(L2pyrimidine)2(NCBH3)2]·2CHCl3 (3·2CHCl3), 3 and 3·2H2O, [FeII(L4pyrimidine)2(NCS)2] (4), 4·H2O, [FeII(L4pyrimidine)2(NCSe)2] (5), 5·2CH3OH, 5·1.5H2O, and [FeII(L4pyrimidine)2(NCBH3)2]·2.5H2O (6·2.5H2O). Single-crystal X-ray diffraction reveals that the N6-coordinated iron(II) centers in 1, 2, 3·2CHCl3, 4, 5, and 5·2CH3OH have two bidentate triazole ligands equatorially bound and two axial NCE co-ligands trans-coordinated. All structures are high spin (HS) at 100 K, except 3·2CHCl3, which is low spin (LS). Solid-state magnetic measurements show that only 3·2CHCl3 ( T1/2 above 400 K) and 5·1.5H2O ( T1/2 = 110 K) undergo spin crossover (SCO); the others remain HS at 300-50 K. When 3·2CHCl3 is heated at 400 K it desorbs CHCl3 becoming 3, which remains HS at 400-50 K. UV-Vis studies in CH2Cl2, CHCl3, (CH3)2CO, CH3CN, and CH3NO2 solutions for the BH3 analogues 3 and 6 led to a 6:1 ratio of L npyrimidine/Fe(II) being employed for the solution studies. These revealed SCO activity in all five solvents, with T1/2 values for the 2-pyrimidine complex (247-396 K) that were consistently higher than for the 4-pyrimidine complex (216-367 K), regardless of solvent choice, consistent with the 2-pyrimidine ring providing a stronger ligand field than the 4-pyrimidine ring. Strong correlations of solvent polarity index with the T1/2 values in those solvents are observed for each complex, enabling predictable T1/2 tuning by up to 150 K. While this correlation is tantalizing, here it may also be reflecting solvent-dependent speciation-so future tests of this concept should employ more stable complexes. Differences between solid-state (ligand field; crystal packing; solvent content) and solution (ligand field; solvation; speciation) effects on SCO are highlighted.

7.
Dalton Trans ; 47(34): 11749-11759, 2018 Aug 29.
Article in English | MEDLINE | ID: mdl-29809223

ABSTRACT

Three new tetradentate imine ligands, HLHBr, HLClH and HLBrH (HLR1R2) were synthesised by 2 : 1 condensation of the appropriately n-halo substituted pyridine-2-carboxaldehyde (5-bromo-4a, 6-bromo-4b or 6-chloro-4c) with 1,3-diaminopropan-2-ol (5). Reactions of each of these three ligands with one equivalent of cobalt(ii) tetrafluoroborate resulted in the formation of three N4O2 coordinated cobalt(ii) complexes: the anticipated mononuclear complex [CoII(HLHBr)(MeOH)2](BF4)2 (1), and two unexpected dinuclear complexes, [CoII2(LBrH-BF2OMe)]2(BF4)2 (2) and [CoII2(LClH-BF2OMe)]2(BF4)2 (3). Dinuclear 2 and 3 result from complexation of cobalt(ii) to the ligands derived from the sterically demanding 6-halo substituted pyridine-2-carboxaldehydes (4b and 4c) undergoing rearrangement, reacting with MeOH and a BF4 anion, resulting in a pair of borate ester bridges between the two cobalt(ii) centres. A similar type of rearrangement is proposed for the PF6 analogues. Cyclic voltammetry in acetonitrile reveals that cobalt(ii) complexes 1-3 undergo a quasi-reversible oxidation: Em = 0.57, 0.38 and 0.29 V vs. 0.01 AgNO3/Ag, respectively. The observed Em value is tuned by the ligand, with the 6-chloro-substituent leading to the lowest Em value being observed for the corresponding cobalt complex, 3, rather than for either of the complexes of the n-bromo-substituted ligands (n = 6 or 5), 2 and 1.

8.
Chempluschem ; 83(7): 582-589, 2018 Jul.
Article in English | MEDLINE | ID: mdl-31950638

ABSTRACT

The multistep synthesis of a versatile new 4-substituted 3,5-bis(2-pyridyl)-1,2,4-triazole (Rdpt) ligand, 4-[4-(2-aminomethyl)phenyl]-3,5-bis(2-pyridyl)-4 H-1,2,4-triazole (apdpt), is reported, which features a reactive aminomethyl para-substituent on the phenyl group that points "out of the back" of the triazole. This enables further functionalisation under mild conditions by using a range of esters to form an amide link. Specifically, this proof of principle study demonstrates the synthesis of apdpt successfully appended with gold-binding thioctic acid (tpdpt), graphene-binding/emissive pyrene/propylpyrene (prdpt/pbdpt), and a Langmuir-Blodgett film-forming polyethylene glycol (PEG) tail (pgdpt). These ligands are subsequently reacted with [Fe(pyridine)4 (NCBH3 )2 ] to give the mononuclear iron(II) complexes [Fe(Rdpt)2 (NCBH3 )2 ]⋅solvent, in which Rdpt/solvent is tpdpt/2.5 H2 O (1), prdpt/0.5 CHCl3 ⋅H2 O (2), and pbdpt/0.5 CHCl3 ⋅2 H2 O (3), as red powders. Magnetic studies on these powders indicate that the complexes undergo only very gradual and incomplete spin crossover, from completely or mostly high spin at 300 K, to half or three-quarters high spin at 50 K. Gold nanoparticles are successfully functionalised with the thioctic acid tpdpt ligand to give tpdpt@Au with an average diameter (as determined by TEM) of (3.1±0.7) nm. Preliminary studies on the two pyrene systems in dimethylformamide show that upon excitation at λ=345 nm the blue fluorescence observed for the free ligands is retained, essentially unaffected, in the respective complexes.

9.
Forensic Sci Int ; 278: 32-46, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28689044

ABSTRACT

In contrast to the well-established and highly accurate morphological methods available for sexing adult skeletons, juvenile sex estimation is widely recognised as a difficult task that faces a series of challenges. The acquisition of 3D data, and construction of 3D models from volume or surface scans, has become increasingly common in forensic sciences, and these data offer considerable opportunity for the development and refinement of methods in sex estimation. The suitability and potential of virtual methods for juvenile sex estimation are evaluated with the aims of identifying (1) the benefits and challenges associated with virtual data and quantitative analysis of 3D models, and (2) pathways that may lead to practical improvements for sexing juveniles. The issues associated with sex estimation in juveniles are discussed and approached in the context of a framework that unifies classification results for a given trait, which provide information on its capacity to discriminate between the sexes, with the underlying patterns of dimorphism over ontogeny. Virtual collections of 3D models are suggested as integral to this framework because they enable the magnitude and mode of sexual dimorphism to be comprehensively quantified for a chosen trait or set of traits. Those data can be used to inform decisions about how to apply a method for sex estimation to maximize its success. Virtual collections, through extending the scope of analyses and impacting the way in which questions on sexual dimorphism in juveniles may be answered, are undoubtedly set to play a central role in future research.


Subject(s)
Computer Simulation , Imaging, Three-Dimensional , Sex Determination by Skeleton/methods , Age Determination by Skeleton , Anatomic Landmarks , Bone Development , Child , Child Nutrition Disorders , Datasets as Topic , Discriminant Analysis , Forensic Anthropology , Geography , Humans , Principal Component Analysis
10.
Dalton Trans ; 46(14): 4696-4710, 2017 Apr 05.
Article in English | MEDLINE | ID: mdl-28332677

ABSTRACT

Four tridentate carbazole-based ligands, HLtBu/H {3,6-di(tert-butyl)-1,8-bis[5-(3-benzyl-1,2,3-triazole)]-9H-carbazole}, HLtBu/tBu {3,6-di(tert-butyl)-1,8-bis[5-(3-(4-tert-butyl)benzyl-1,2,3-triazole)]-9H-carbazole}, HLH/H {1,8-bis[5-(3-benzyl-1,2,3-triazole)]-9H-carbazole} and HLH/tBu {1,8-bis[5-(3-(4-tert-butyl)benzyl-1,2,3-triazole)]-9H-carbazole}, were prepared and complexed with cobalt(ii) tetrafluoroborate. In situ air oxidation resulted in cobalt(iii) complexes 1-4 with the general formula [CoIII(L)2]BF4·xH2O (1: L = LtBu/H, x = 2; 2: L = LtBu/tBu, x = 1; 3: L = LH/H, x = 0.5; 4: L = LH/tBu, x = 2). X-ray structural characterisation confirmed that the four complexes are isostructural, with two orthogonally coordinated deprotonated tridentate ligands providing an octahedral N6-donor set to the cobalt(iii) ion. 1H NMR studies show that this structure is maintained in CDCl3 and DMSO-d6 solution. Cyclic voltammetry on 1-4 in MeCN showed that all of the complexes exhibit two reversible, one-electron oxidation processes (probably due to ligand oxidations), and an irreversible or quasi-reversible reduction process (probably due to reduction of Co(iii) to Co(ii)). As expected, the oxidations move 120-140 mV to lower potentials on adding tert-butyl substituents to the 3 and 6 positions of the carbazole rings, and unsurprisingly the potentials are far less sensitive to the nature of the benzyl ring substituents.

11.
Ann. intern. med ; 166(6)Mar. 2017. tab
Article in English | BIGG - GRADE guidelines | ID: biblio-948599

ABSTRACT

DESCRIPTION: The American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) jointly developed this guideline to present the evidence and provide clinical recommendations based on the benefits and harms of higher versus lower blood pressure targets for the treatment of hypertension in adults aged 60 years or older. METHODS: This guideline is based on a systematic review of published randomized, controlled trials for primary outcomes and observational studies for harms only (identified through EMBASE, the Cochrane Database of Systematic Reviews, MEDLINE, and ClinicalTrials.gov), from database inception through January 2015. The MEDLINE search was updated through September 2016. Evaluated outcomes included all-cause mortality, morbidity and mortality related to stroke, major cardiac events (fatal and nonfatal myocardial infarction and sudden cardiac death), and harms. This guideline grades the evidence and recommendations using the GRADE (Grading of Recommendations Assessment, Development, and Evaluation) method. TARGET AUDIENCE AND PATIENT POPULATION: The target audience for this guideline includes all clinicians, and the target patient population includes all adults aged 60 years or older with hypertension. RECOMMENDATION 1: ACP and AAFP recommend that clinicians initiate treatment in adults aged 60 years or older with systolic blood pressure persistently at or above 150 mm Hg to achieve a target systolic blood pressure of less than 150 mm Hg to reduce the risk for mortality, stroke, and cardiac events. (Grade: strong recommendation, high-quality evidence). ACP and AAFP recommend that clinicians select the treatment goals for adults aged 60 years or older based on a periodic discussion of the benefits and harms of specific blood pressure targets with the patient. RECOMMENDATION 2: ACP and AAFP recommend that clinicians consider initiating or intensifying pharmacologic treatment in adults aged 60 years or older with a history of stroke or transient ischemic attack to achieve a target systolic blood pressure of less than 140 mm Hg to reduce the risk for recurrent stroke. (Grade: weak recommendation, moderate-quality evidence). ACP and AAFP recommend that clinicians select the treatment goals for adults aged 60 years or older based on a periodic discussion of the benefits and harms of specific blood pressure targets with the patient. RECOMMENDATION 3: ACP and AAFP recommend that clinicians consider initiating or intensifying pharmacologic treatment in some adults aged 60 years or older at high cardiovascular risk, based on individualized assessment, to achieve a target systolic blood pressure of less than 140 mm Hg to reduce the risk for stroke or cardiac events. (Grade: weak recommendation, low-quality evidence). ACP and AAFP recommend that clinicians select the treatment goals for adults aged 60 years or older based on a periodic discussion of the benefits and harms of specific blood pressure targets with the patient.


Subject(s)
Humans , Aged , Aged, 80 and over , Hypertension/drug therapy , Antihypertensive Agents/therapeutic use , Cardiovascular Diseases/prevention & control , Age Factors , Risk Assessment , Stroke/prevention & control , Secondary Prevention , GRADE Approach
12.
Ann. intern. med ; 166(4)Feb. 2017. tab
Article in English | BIGG - GRADE guidelines | ID: biblio-948604

ABSTRACT

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations on oral pharmacologic treatment of type 2 diabetes in adults. This guideline serves as an update to the 2012 ACP guideline on the same topic. This guideline is endorsed by the American Academy of Family Physicians. METHODS: This guideline is based on a systematic review of randomized, controlled trials and observational studies published through December 2015 on the comparative effectiveness of oral medications for type 2 diabetes. Evaluated interventions included metformin, thiazolidinediones, sulfonylureas, dipeptidyl peptidase-4 (DPP-4) inhibitors, and sodium-glucose cotransporter-2 (SGLT-2) inhibitors. Study quality was assessed, data were extracted, and results were summarized qualitatively on the basis of the totality of evidence identified by using several databases. Evaluated outcomes included intermediate outcomes of hemoglobin A1c, weight, systolic blood pressure, and heart rate; all-cause mortality; cardiovascular and cerebrovascular morbidity and mortality; retinopathy, nephropathy, and neuropathy; and harms. This guideline grades the recommendations by using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. TARGET AUDIENCE AND PATIENT POPULATION: The target audience for this guideline includes all clinicians, and the target patient population includes adults with type 2 diabetes. RECOMMENDATION 1: ACP recommends that clinicians prescribe metformin to patients with type 2 diabetes when pharmacologic therapy is needed to improve glycemic control. (Grade: strong recommendation; moderate-quality evidence). RECOMMENDATION 2: ACP recommends that clinicians consider adding either a sulfonylurea, a thiazolidinedione, an SGLT-2 inhibitor, or a DPP-4 inhibitor to metformin to improve glycemic control when a second oral therapy is considered. (Grade: weak recommendation; moderate-quality evidence.) ACP recommends that clinicians and patients select among medications after discussing benefits, adverse effects, and costs.(AU)


Subject(s)
Humans , Diabetes Mellitus, Type 2/drug therapy , Hypoglycemic Agents/administration & dosage , Glycated Hemoglobin , Weight Loss , Diabetic Angiopathies/prevention & control , Drug Therapy, Combination , Arterial Pressure/drug effects , Sulfonylurea Receptors/administration & dosage , Heart Rate/drug effects , Metformin/administration & dosage
13.
Chemistry ; 23(11): 2517-2521, 2017 Feb 21.
Article in English | MEDLINE | ID: mdl-27981632

ABSTRACT

In a proof-of-principle study, a soluble macrocyclic single-molecule magnet (SMM) containing a CuII3 TbIII magnetic core was covalently grafted onto small gold nanoparticles pre-functionalised with carboxylate-terminated tethers. A modified microemulsion method allowed production of the small and monodisperse nanoparticles (approximately 3.5 nm in diameter) for the chemisorption of a large amount of intact macrocyclic complexes in the hybrid system.

14.
Dalton Trans ; 45(45): 18089-18093, 2016 Nov 15.
Article in English | MEDLINE | ID: mdl-27808299

ABSTRACT

Crystallisation of the tetranuclear 3d-4f Single-Molecule Magnet (SMM) [CuTbIII(LEt)(NO3)3(MeOH)]·MeOH (1) with Na2[tpa] (tpa = terephthalate and H6LEt is the [3 + 3] imine macrocycle derived from 1,4-diformyl-2,3-dihydroxybenzene and 1,2-diaminoethane) gives a structurally characterised one-dimensional cationic polymer {[CuTbIII(LEt)(tpa)(H2O)3](NO3)·0.5H2O·0.25MeOH}n (2). A comparative study of the static and dynamic magnetic properties of 2 and its precursor, 1, is reported.

15.
Angew Chem Int Ed Engl ; 55(48): 15067-15071, 2016 11 21.
Article in English | MEDLINE | ID: mdl-27730720

ABSTRACT

Materials capable of sensing volatile guests at room temperature by an easily monitored set of outputs are of great appeal for development as chemical sensors of small volatile organics and toxic gases. Herein the dinuclear iron(II) complex, [FeII2 (L)2 (CH3 CN)4 ](BF4 )4 ⋅2 CH3 CN (1) [L=4-(4-methylphenyl)-3-(3-pyridazinyl)-5-pyridyl-4H-1,2,4-triazole], is shown to undergo reversible single-crystal-to-single-crystal (SCSC) transformations upon exposure to vapors of different guests: 1 (MeCN)⇌2 (EtOH)→3 (H2 O)⇌1 (MeCN). Whilst 1 and 2 remain dimetallic, SCSC to 3 involves conversion to a 1D polymeric chain (due to a change in L bridging mode), which, remarkably, can undergo SCSC de-polymerization, reforming dimetallic 1. Additionally, SC-XRD studies of two ordered transient forms, 1TF3 and 2TF3, confirm that guest exchange occurs by diffusion of the new guests into the non-porous lattices as the old guests leave. These reversible SCSC events also induce color and magnetic responses. Indeed dark red 1 is spin crossover active (T1/2 ↓ 356 K; T1/2 ↑ 369 K), whilst orange 2 and yellow 3 remain high spin.

16.
Am J Phys Anthropol ; 161(4): 656-666, 2016 12.
Article in English | MEDLINE | ID: mdl-27696347

ABSTRACT

OBJECTIVES: Whereas the differences in lateral enamel growth between fossil and modern populations have been well documented in recent years, few studies report on the variability in perikymata counts and distribution between modern human populations. There is a need for information on modern human populations from a wide range of geographical regions and archaeological populations to determine whether existing patterns are representative. The aim of this paper is to document enamel surface microstructures in human teeth from a previously unknown region and time period comprehensively. MATERIALS AND METHODS: Perikymata counts and distribution are assessed in a large sample of relatively unworn permanent incisors from the mid-Holocene site of Çatalhöyük in Turkey. RESULTS: All four incisor types exhibit total perikymata counts that are intermediate between values for modern samples from northern Europe and South Africa. The perikymata distribution followed the modern human pattern of a marked decrease in spacing in the cervical half of the crown. DISCUSSION: The existence of regional differences in perikymata number and distribution demonstrates the importance of documenting enamel microstructures in a wider range of modern human populations, both geographically and chronologically.


Subject(s)
Dental Enamel/growth & development , Incisor/growth & development , Anthropology, Physical , History, Ancient , Humans , Imaging, Three-Dimensional , Odontometry , Turkey
17.
Inorg Chem ; 55(9): 4152-65, 2016 05 02.
Article in English | MEDLINE | ID: mdl-27082018

ABSTRACT

Access to a new family of thioether-linked PSRT ligands, 4-substituted-3,5-bis{[(2-pyridylmethyl)sulfanyl]methyl}-4H-1,2,4-triazoles (analogues of the previously studied amino-linked PMRT ligands), has been established. Four such ligands have been prepared, PSPhT, PS(i)BuT, PS(t-Bu)PhT, and PS(Me)PhT, with R = Ph, (i)Bu, (t-Bu)Ph, and (Me)Ph, respectively. Three dinuclear colorless to pale green iron(II) complexes, [Fe(II)2(PSRT)2](BF4)4·solvent, featuring N4S2 donor sets, were prepared. Single-crystal structure determinations on [Fe(II)2(PSPhT)2](BF4)4·2MeCN·H2O, [Fe(II)2(PSPhT)2](BF4)4·2(1)/2MeCN·(1)/2H2O·THF, [Fe(II)2(PS(Me)PhT)2](BF4)4·2MeCN, and [Fe(II)2(PS(i)BuT)2](BF4)4·4MeCN reveal that all four are stabilized in the [HS-HS] state to 100 K and that both possible binding modes of the bis-terdentate ligands, cis- and trans-axial, are observed. Variable-temperature magnetic susceptibility studies of air-dried crystals (solvatomorphs of the single crystal samples) reveal the first examples of spin crossover (SCO) for a dinuclear iron(II) complex with N4S2 coordination. Specifically, [Fe(II)2(PSPhT)2](BF4)4·2(1)/2H2O undergoes a multistep but complete SCO from [HS-HS] to [LS-LS], whereas [Fe(II)2(PS(Me)PhT)2](BF4)4·1(1)/2MeCN·2H2O exhibits a half-SCO from [HS-HS] to [HS-LS]. In contrast, [Fe(II)2(PS(i)BuT)2](BF4)4·MeCN·H2O remains [HS-HS] down to 50 K. The reflectance spectrum of pale green [Fe(II)2(PSPhT)2](BF4)4·(1)/2CHCl3·2(1)/2H2O (solvatomorph A) reveals a trace of LS character (572 nm band (1)A1g → (1)T1g). Evans' (1)H NMR method and UV-vis spectroscopy studies revealed that on cooling dark green acetonitrile solutions of these complexes from 313 to 233 K, all three undergo SCO centered at or near room temperature. The tendency of the complexes to go LS in solution reflects the electronic impact of R on the σ-donor strength of the PSRT ligand, whereas the opposite trend in stabilization of the LS state is seen in the solid state, where crystal packing effects, of the R group and solvent content, dominate the SCO behavior.

18.
Inorg Chem ; 54(6): 2902-9, 2015 Mar 16.
Article in English | MEDLINE | ID: mdl-25732607

ABSTRACT

Two new Rdpt ligands featuring long "tails", padpt (N-4H-1,2,4-triazole-3,5-di(2-pyridyl)palmitamide) and hpdpt (4-(4-heptadecafluoroctylphenyl)-3,5-bis(2-pyridyl)-4H-1,2,4-triazole), were made and reacted with [Fe(II)(py)4(NCS)2] to give pinkish-red [Fe(II)(padpt)2(SCN)2] (1) and purple-red [Fe(II)(hpdpt)2(SCN)2] (2) as solvent-free crystals. Magnetic measurements reveal that both 1 and 2 exhibit complete and reproducible spin crossovers, with a far lower T1/2 for the amide-alkyl tailed 1 (182 K) than for the fluorocarbon tailed 2 (248 K), which in turn is far lower than the T1/2 of 290 K previously reported for the nonamide-alkyl tailed analogue [Fe(II)(C16dpt)2(SCN)2]·(2)/3H2O (3). Structure determinations for 1 and 2 in both the high spin (HS) and low spin (LS) states confirm the expected trans-NCS conformation and reveal that (a) the "tails" interdigitate and (b) the LS forms are less distorted than the HS forms (Σ = 58-70° vs 47-54°). DSC and Raman spectroscopy confirmed the high tail-dependence of the SCO events in 1 and 2, as well as in 3, with the Raman data giving T1/2 values of 190, 243, and 285 K, respectively. Bright orange single crystals of the solvatomorph [Fe(II)(hpdpt)2(SCN)2]·MeOH·H2O (2solv) were also structurally and magnetically characterized and, in contrast to 2, found to remain HS down to 4 K, providing further evidence of the huge impact of crystal packing on SCO. Both 1 and 2 form stable Langmuir films at an air-water interface, a single layer of which can be transferred to a solid support.

19.
Ann. intern. med ; 162(5)2015. tab
Article in English | BIGG - GRADE guidelines | ID: biblio-946829

ABSTRACT

DESCRIPTION: The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations based on the comparative effectiveness of treatments of pressure ulcers. METHODS: This guideline is based on published literature on this topic that was identified by using MEDLINE, EMBASE, CINAHL, EBM Reviews, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, and the Health Technology Assessment database through February 2014. Searches were limited to English-language publications. The outcomes evaluated for this guideline include complete wound healing, wound size (surface area, volume, and depth) reduction, pain, prevention of sepsis, prevention of osteomyelitis, recurrence rate, and harms of treatment (including but not limited to pain, dermatologic complications, bleeding, and infection). This guideline grades the quality of evidence and strength of recommendations by using ACP's clinical practice guidelines grading system. The target audience for this guideline includes all clinicians, and the target patient population is patients with pressure ulcers. RECOMMENDATION 1: ACP recommends that clinicians use protein or amino acid supplementation in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence). RECOMMENDATION 2: ACP recommends that clinicians use hydrocolloid or foam dressings in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence). RECOMMENDATION 3: ACP recommends that clinicians use electrical stimulation as adjunctive therapy in patients with pressure ulcers to accelerate wound healing. (Grade: weak recommendation, moderate-quality evidence).


Subject(s)
Humans , Adult , Wound Healing , Pressure Ulcer/therapy , Wound Closure Techniques , Comparative Effectiveness Research
20.
Haemophilia ; 20(5): 666-73, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24720617

ABSTRACT

Prophylactic use of treatment is important for good outcomes in haemophilia, yet adherence can be suboptimal. To better understand the relationship between treatment adherence and patients' beliefs about treatment there is a need to quantify patients' treatment attitudes. The aim of this study was to develop a brief, clinically relevant, patient-reported outcome (PRO) to measure ease of use and patients' preference for haemophilia treatment. A 40-item questionnaire was completed by male adults with haemophilia A from Austria, Germany, Italy, Spain and the UK. Robust statistical methods for item evaluation including item-level statistics, dimensionality analyses and input from clinical and outcomes experts were used to inform item reduction. Retained items were subjected to psychometric evaluation including exploratory factor analysis (EFA), known-groups validity and internal consistency reliability. 273 patients completed the questionnaire. Of the 40 items, 28 items were flagged for possible deletion based on item-level statistics, three of which were retained due to clinical relevance. Two items had acceptable statistical performance but were deleted based on low clinical relevance. A total of 13 items were retained. EFA produced a conceptually defined 5-factor solution. The survey had acceptable known-groups validity and internal consistency. Refinements were made to wording and scoring, and one new item was added to assess general ease of use, resulting in a 14-item questionnaire - the HaemoPREF. Preliminary measurement properties of the HaemoPREF support the instrument to evaluate patient perception and preference for haemophilia treatment. Further psychometric evaluation is required to examine and confirm the measurement properties of the scale.


Subject(s)
Coagulants/therapeutic use , Factor VIII/therapeutic use , Hemophilia A/drug therapy , Medication Adherence/psychology , Patient Preference/psychology , Surveys and Questionnaires , Adolescent , Adult , Aged , Europe , Hemophilia A/psychology , Humans , Male , Middle Aged , Patient Satisfaction , Psychometrics , Reproducibility of Results , Young Adult
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