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1.
J Org Chem ; 88(14): 9853-9869, 2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37432502

RESUMO

Triarylsilanols have been reported as the first silicon-centered molecular catalysts for direct amidation of carboxylic acids with amines as identified after a screen of silanols, silanediols, disiloxanediols, and incompletely condensed silsesquioxanes as potential homogeneous catalysts. Subsequent synthesis and testing of various electronically differentiated triarylsilanols have identified tris(p-haloaryl)silanols as more active than the parent triarylsilanol, where the bromide congener is found to be the most active. Catalyst decomposition can be observed by NMR methods, but RPKA methods reveal that product inhibition is operative, where tertiary amides are more inhibitory than secondary amides. Studies using an authentically synthesized triaryl silylester as a putative intermediate in the catalytic system enable a plausible mechanism to be proposed as supported by computationals.

2.
Phys Chem Chem Phys ; 24(11): 6453-6468, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35244651

RESUMO

In this work we investigate the structure-property relationships in a series of alkylimidazolium ionic liquids with almost identical molecular weight. Using a combination of theoretical calculations and experimental measurements, we have shown that re-arranging the alkyl side chain or adding functional groups results in quite distinct features in the resultant ILs. The synthesised ILs, although structurally very similar, cover a wide spectrum of properties ranging from highly fluid, glass forming liquids to high melting point crystalline salts. Theoretical ab initio calculations provide insight on minimum energy orientations for the cations, which then are compared to experimental X-ray crystallography measurements to extract information on hydrogen bonding and to verify our understanding of the studied structures. Molecular dynamics simulations of the simplest (core) ionic liquids are used in order to help us interpret our experimental results and understand better why methylation of C2 position of the imidazolium ring results in ILs with such different properties compared to their non-methylated analogues.

3.
Inorg Chem ; 58(15): 10346-10356, 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31334640

RESUMO

A comparison of chlorido-gallium functionalized alkoxides as precursors for aerosol-assisted chemical vapor deposition (AACVD) was carried out. Variable-temperature (VT)-NMR studies were used to probe the fluxional behavior of these alkoxides in solution, and hence their utility as precursors. The synthesis involved the initial isolation of the dimer [GaCl(NMe2)2]2 via a salt metathesis route from GaCl3 and 2 equiv of LiNMe2. This dimer was then reacted with 4 equiv of HOCH2CH2CH2NEt2, resulting in the formation of Ga[µ-(OCH2CH2CH2NEt2)2GaCl2]3 (1). Mass spectrometry and VT-NMR confirmed the oligomeric structure of 1. Tuning of the ligand properties, namely, the chain length and substituents on N, resulted in formation of the monomers [GaCl(OR)2] (R = CH2CH2NEt2, (2); CH2CH2CH2NMe2, (3)). VT-NMR studies, supported by density functional theory calculations, confirmed that the ligands in both 2 and 3 possess a hemilabile coordination to the gallium center, owing to either a shorter carbon backbone (2) or less steric hindrance (3). Both 2 and 3 were selected for use as precursors for AACVD: deposition at 450 °C gave thin films of amorphous Ga2O3, which were subsequently annealed at 1000 °C to afford crystalline Ga2O3 material. The films were fully characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and energy dispersive X-ray analysis.

4.
Gynecol Obstet Invest ; 83(3): 234-240, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29539625

RESUMO

BACKGROUND: The diagnostic accuracy of colposcopy is poor for detecting precancerous cervical lesions. OBJECTIVES: We assessed the performance of colposcopy for identifying cervical intraepithelial neoplasia grade 2 or worse (CIN2+), before and after including a dynamic spectral imaging (DSI) map that quantifies and maps acetowhitening to assist subsequent biopsy of suspicious lesions. METHODS: Four hundred and twenty-five women were examined at a multi-center setting in Wales, of which 393 women were included in the final analysis. RESULTS: For all referrals, the sensitivity of conventional colposcopy for histologically confirmed CIN2+ was 51.5%, the specificity was 92.0%, the positive predictive value was 56.7%, and the negative predictive value (NPV) was 90.4%. With the incorporation of the DSI map in predicting CIN2+, these became 84.8, 61.5, 30.8, and 95.3% respectively. The increase of sensitivity was statistically significant (p < 0.001). For the 236 women having colposcopy after low-grade (LG) cytology, with the incorporation of DSI, the sensitivity for CIN2+ increased from 27.3 to 86.4% (p < 0.001) and the NPV from 92.6 to 97.8%. CONCLUSIONS: Colposcopy with DSI results in improved sensitivity to detect CIN2+ and maintains a high NPV for all referrals and especially for those with LG referral cytology.


Assuntos
Colposcopia/métodos , Imagem Óptica/métodos , Displasia do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/diagnóstico , Adulto , Biópsia/métodos , Feminino , Humanos , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Neoplasias do Colo do Útero/patologia , País de Gales , Displasia do Colo do Útero/patologia
5.
Chemistry ; 22(1): 302-9, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26608231

RESUMO

For the first time, a versatile electrolyte bath is described that can be used to electrodeposit a wide range of p-block elements from supercritical difluoromethane (scCH2 F2 ). The bath comprises the tetrabutylammonium chlorometallate complex of the element in an electrolyte of 50×10(-3)  mol dm(-3) tetrabutylammonium chloride at 17.2 MPa and 358 K. Through the use of anionic ([GaCl4 ](-) , [InCl4 ](-) , [GeCl3 ](-) , [SnCl3 ](-) , [SbCl4 ](-) , and [BiCl4 ](-) ) and dianionic ([SeCl6 ](2-) and [TeCl6 ](2-) ) chlorometallate salts, the deposition of elemental Ga, In, Ge, Sn, Sb, Bi, Se, and Te is demonstrated. In all cases, with the exception of gallium, which is a liquid under the deposition conditions, the resulting deposits are characterised by SEM, energy-dispersive X-ray analysis, XRD and Raman spectroscopy. An advantage of this electrolyte system is that the reagents are all crystalline solids, reasonably easy to handle and not highly water or oxygen sensitive. The results presented herein significantly broaden the range of materials accessible by electrodeposition from supercritical fluid and open up the future possibility of utilising the full scope of these unique fluids to electrodeposit functional binary or ternary alloys and compounds of these elements.

6.
Phys Chem Chem Phys ; 18(21): 14359-69, 2016 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-27166921

RESUMO

We present investigations into a variety of supporting electrolytes and supercritical fluids probing the phase and conductivity behaviour of these systems and show that they not only provide sufficient electrical conductivity for an electrodeposition bath, but match the requirements imposed by the different precursors and process parameters, e.g. increased temperature, for potential deposition experiments. The two supercritical fluids that have been explored in this study are difluoromethane (CH2F2) and 1,1-difluoroethane (CHF2CH3). For CH2F2, the phase behaviour and electrical conductivity of eight ionic compounds have been studied. Each compound consists of a cation and an anion from the selected candidates i.e. tetramethylammonium ([N(CH3)4](+)), tetrabutylammonium ([N((n)C4H9)4](+)), 1-ethyl-3-methylimidazolium ([EMIM](+)) and 1-butyl-3-methylimidazolium ([BMIM](+)) for cations, and tetrakis(perfluoro-tert-butoxy)aluminate ([Al(OC(CF3)3)4](-)), chloride (Cl(-)), trifluoromethyl sulfonimide ([NTf2](-)) and tris(pentafluoroethyl)trifluorophosphate ([FAP](-)) for anions. For CHF2CH3, [N((n)C4H9)4][BF4] and [N((n)C4H9)4][B{3,5-C6H3(CF3)2}4] have been investigated for comparison with the previously measured solubility and conductivity in CH2F2. We have found that [N((n)C4H9)4][Al(OC(CF3)3)4], [N((n)C4H9)4][FAP] and [N(CH3)4][FAP] have much higher molar conductivity in scCH2F2 at similar conditions than [N((n)C4H9)4][BF4], a widely used commercial electrolyte. Additionally, scCHF2CH3 shows potential for use as the solvent for supercritical fluid electrodeposition, especially at high temperatures since high density of this fluid can be achieved at lower operating pressures than similar fluids that can be used to produce electrochemical baths with comparable conductivity.

7.
Inorg Chem ; 54(6): 2497-9, 2015 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-25723901

RESUMO

Unprecedented homoleptic octathioether macrocyclic coordination to Na(+) in [Na([24]aneS8)](+) has been achieved by using Na[B{3,5-(CF3)2-C6H3}4] as a source of "naked" Na(+) ions and confirmed crystallographically, with d(Na-S) = 2.9561(15)-3.0524(15) Å. Density functional theory calculations show that there is electron transfer from the S 3p and C 2p valence orbitals of the ligand to the 3s and 3p orbitals of the Na(+) ion upon complexation.

8.
Chemistry ; 20(17): 5019-27, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24644266

RESUMO

The Ge(IV) chlorometallate complexes, [EMIM]2 [GeCl6 ], [EDMIM]2 [GeCl6 ] and [PYRR]2 [GeCl6 ] (EMIM=1-ethyl-3-methylimidazolium; EDMIM=2,3-dimethyl-1-ethylimidazolium; PYRR=N-butyl-N-methylpyrrolidinium) have been synthesised and fully characterised; the first two also by single-crystal X-ray diffraction. The imidazolium chlorometallates exhibited significant CH⋅⋅⋅Cl hydrogen bonds, resulting in extended supramolecular assemblies in the solid state. Solution (1) H NMR data also showed cation-anion association. The synthesis and characterisation of Ge(II) halometallate salts [EMIM][GeX3 ] (X=Cl, Br, I) and [PYRR][GeCl3 ], including single-crystal X-ray analyses for the homologous series of imidazolium salts, are reported. In these complexes, the intermolecular interactions are much weaker in the solid state and they appear not to be significantly associated in solution. Cyclic-voltammetry experiments on the Ge(IV) species in CH2 Cl2 solution showed two distinct, irreversible reduction waves attributed to Ge(IV) -Ge(II) and Ge(II) -Ge(0) , whereas the Ge(II) species exhibited one irreversible reduction wave. The potential for the Ge(II) -Ge(0) reduction was unaffected by changing the cation, although altering the oxidation state of the precursor from Ge(IV) to Ge(II) does have an effect; for a given cation, reduction from the [GeCl3 ](-) salts occurred at a less cathodic potential. The nature of the halide co-ligand also has a marked influence on the reduction potential for the Ge(II) -Ge(0) couple, such that the reduction potentials for the [GeX3 ](-) salts become significantly less cathodic when the halide (X) is changed Cl→Br→I.

9.
Chemistry ; 20(33): 10503-13, 2014 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-25043194

RESUMO

Bis-ß-ketoimine ligands of the form [(CH2 )n {N(H)C(Me)CHC(Me)O}2 ] (L(n) H2 , n=2, 3 and 4) were employed in the formation of a range of gallium complexes [Ga(L(n) )X] (X=Cl, Me, H), which were characterised by NMR spectroscopy, mass spectrometry and single-crystal X-ray diffraction analysis. The ß-ketoimine ligands have also been used for the stabilisation of rare gallium hydride species [Ga(L(n) )H] (n=2 (7); n=3 (8)), which have been structurally characterised for the first time, confirming the formation of five-coordinate, monomeric species. The stability of these hydrides has been probed through thermal analysis, revealing stability at temperatures in excess of 200 °C. The efficacy of all the gallium ß-ketoiminate complexes as molecular precursors for the deposition of gallium oxide thin films by chemical vapour deposition (CVD) has been investigated through thermogravimetric analysis and deposition studies, with the best results being found for a bimetallic gallium methyl complex [L(3) {GaMe2 }2 ] (5) and the hydride [Ga(L(3) )H] (8). The resulting films (F5 and F8, respectively) were amorphous as-deposited and thus were characterised primarily by XPS, EDXA and SEM techniques, which showed the formation of stoichiometric (F5) and oxygen-deficient (F8) Ga2 O3 thin films.

10.
Chem Sci ; 15(19): 7342-7358, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38756793

RESUMO

The overall performance of lithium batteries remains unmatched to this date. Decades of optimisation have resulted in long-lasting batteries with high energy density suitable for mobile applications. However, the electrolytes used at present suffer from low lithium transference numbers, which induces concentration polarisation and reduces efficiency of charging and discharging. Here we show how targeted modifications can be used to systematically evolve anion structural motifs which can yield electrolytes with high transference numbers. Using a multidisciplinary combination of theoretical and experimental approaches, we screened a large number of anions. Thus, we identified anions which reach lithium transference numbers around 0.9, surpassing conventional electrolytes. Specifically, we find that nitrile groups have a coordination tendency similar to SO2 and are capable of inducing the formation of Li+ rich clusters. In the bigger picture, we identified a balanced anion/solvent coordination tendency as one of the key design parameters.

11.
J Biol Chem ; 287(10): 7146-58, 2012 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-22130672

RESUMO

Retinoblastoma-binding protein-6 (RBBP6) plays a facilitating role, through its RING finger-like domain, in the ubiquitination of p53 by Hdm2 that is suggestive of E4-like activity. Although the presence of eight conserved cysteine residues makes it highly probable that the RING finger-like domain coordinates two zinc ions, analysis of the primary sequence suggests an alternative classification as a member of the U-box family, the members of which do not bind zinc ions. We show here that despite binding two zinc ions, the domain adopts a homodimeric structure highly similar to those of a number of U-boxes. Zinc ions could be replaced by cadmium ions without significantly disrupting the structure or the stability of the domain, although the rate of substitution was an order of magnitude slower than any previous measurement, suggesting that the structure is particularly stable, a conclusion supported by the high thermal stability of the domain. A hallmark of U-box-containing proteins is their association with chaperones, with which they cooperate in eliminating irretrievably unfolded proteins by tagging them for degradation by the proteasome. Using a yeast two-hybrid screen, we show that RBBP6 interacts with chaperones Hsp70 and Hsp40 through its N-terminal ubiquitin-like domain. Taken together with the structural similarities to U-box-containing proteins, our data suggest that RBBP6 plays a role in chaperone-mediated ubiquitination and possibly in protein quality control.


Assuntos
Proteínas de Transporte/química , Proteínas de Ligação a DNA/química , Cádmio/química , Cádmio/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Choque Térmico HSP40/química , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP70/genética , Proteínas de Choque Térmico HSP70/metabolismo , Humanos , Ligação Proteica/fisiologia , Domínios RING Finger , Saccharomyces cerevisiae/genética , Técnicas do Sistema de Duplo-Híbrido , Ubiquitina-Proteína Ligases , Ubiquitinação/fisiologia , Zinco/química , Zinco/metabolismo
12.
Inorg Chem ; 52(9): 5185-93, 2013 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-23590521

RESUMO

The reaction of SiX4 (X = Cl or Br) with PMe3 in anhydrous CH2Cl2 forms trans-[SiX4(PMe3)2], while the diphosphines, Me2P(CH2)2PMe2, Et2P(CH2)2PEt2, and o-C6H4(PMe2)2 form cis-[SiX4(diphosphine)], all containing six-coordinate silicon centers. With Me2PCH2PMe2 the product was trans-[SiCl4(κ(1)-Me2PCH2PMe2)2]. The complexes have been characterized by X-ray crystallography, microanalysis, IR, and multinuclear ((1)H, (13)C{(1)H}, and (31)P{(1)H}) NMR spectroscopies. The complexes are stable solids and not significantly dissociated in nondonor solvents, although they are very moisture and oxygen sensitive. This stability conflicts with the predictions of recent density functional theory (DFT) calculations (Wilson et al. Inorg. Chem. 2012, 51, 7657-7668) which suggested six-coordinate silicon phosphines would be unstable, and also contrasts with the failure to isolate complexes with SiF4 (George et al. Dalton Trans. 2011, 40, 1584-1593). No reaction occurred between phosphines and SiI4, or with SiX4 and arsine ligands including AsMe3 and o-C6H4(AsMe2)2. Attempts to make five-coordinate [SiX4(PR3)] using the sterically bulky phosphines, P(t)Bu3, P(i)Pr3, or PCy3 failed, with no apparent reaction occurring, consistent with predictions (Wilson et al. Inorg. Chem. 2012, 51, 7657-7668) that such compounds would be very endothermic, while the large cone angles of the phosphines presumably preclude formation of six-coordination at the small silicon center. The reaction of Si2Cl6 with PMe3 or the diphosphines in CH2Cl2 results in instant disproportionation to the SiCl4 adducts and polychlorosilanes, but from hexane solution very unstable white [Si2Cl6(PMe3)2] and [Si2Cl6(diphosphine)] (diphosphine = Me2P(CH2)2PMe2 or o-C6H4(PMe2)2) precipitate. The reactions of SiHCl3 with PMe3 and Me2P(CH2)2PMe2 also produce the SiCl4 adducts, but using Et2P(CH2)2PEt2, colorless [SiHCl3{Et2P(CH2)2PEt2}] was isolated, which was characterized by an X-ray structure which showed a pseudo-octahedral complex with the Si-H trans to P. Attempts to reduce the silicon(IV) phosphine complexes to silicon(II) were unsuccessful, contrasting with the isolation of stable N-heterocyclic carbene adducts of Si(II).

13.
Acta Crystallogr C ; 69(Pt 5): 560-4, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23629914

RESUMO

Tribenzylphosphane, PBz3 (C21H21P), crystallizes in a notably different unit cell to its Group 15 analogues NBz3 and SbBz3. The packing is dominated by face-edge π-interactions which result in infinite columns of molecules parallel to the b axis; these columns are linked by further face-edge π-interactions into sheets of columns parallel to the [101] direction. Its hydrochloride salt, tribenzylphosphonium hydrogen dichloride-tribenzylphosphane (1/1), lies on a threefold axis within a trigonal crystal system. It exists in the solid state as a hydrogen-bridged dimer with the composition [H(PBz3)2](+)[HCl2](-) (C42H43P2(+)·HCl2(-)). The cation is the first structurally authenticated example of a phosphane acting as a hydrogen-bond acceptor to a phosphonium group and the cations are linked into a three-dimensional network through intermolecular face-edge π-interactions.

15.
Vet Clin North Am Food Anim Pract ; 39(3): 535-543, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37419831

RESUMO

This article is an overview of trace mineral nutrition, disease association with dietary inadequacy of trace minerals, and the associated diseases in goats. The trace minerals most commonly associated with deficiency-related diseases encountered in clinical veterinary medicine, Copper, Zinc, and Selenium, are discussed in greater detail than those less commonly associated with diseases. However, Cobalt, Iron, and Iodine are also discussed. The signs of deficiency-associated diseases, along with diagnostic evaluation to confirm such diseases, are also discussed.

16.
Chemistry ; 18(19): 6079-87, 2012 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-22461280

RESUMO

The donor-functionalised alkoxides {Me(3-x)N(CH(2)CH(2)O)(x)} (L(x); x = 1, 2) have been used to form gallium hydride complexes [{GaH(2)(L(1))}(2)] and [{GaH(L(2))}(2)] that are stable and isolable at room temperature. Along with a heteroleptic gallium tris(alkoxide) complex [Ga(L(1))(3)] and the dimeric complex [{GaMe(L(2))}(2)], these compounds have been used as single-source precursors for the deposition of Ga(2)O(3) by aerosol-assisted chemical vapour deposition (AACVD) with toluene as solvent. The resulting films were mostly transparent, indicating low levels of carbon contamination, and they were also mainly amorphous. However, [Ga(L(1))(3)] did contain visibly crystalline material deposited at a substrate temperature of 450 °C, by far the lowest ever observed for the CVD of gallium oxide.

17.
Inorg Chem ; 51(11): 6385-95, 2012 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-22594881

RESUMO

Bis(ß-ketoimine) ligands, [R{N(H)C(Me)-CHC(Me)═O}(2)] (L(1)H(2), R = (CH(2))(2); L(2)H(2), R = (CH(2))(3)), linked by ethylene (L(1)) and propylene (L(2)) bridges have been used to form aluminum, gallium, and indium chloride complexes [Al(L(1))Cl] (3), [Ga(L(n))Cl] (4, n = 1; 6, n = 2) and [In(L(n))Cl] (5, n = 1; 7, n = 2). Ligand L(1) has also been used to form a gallium hydride derivative [Ga(L(1))H] (8), but indium analogues could not be made. ß-ketoimine ligands, [Me(2)N(CH(2))(3)N(H)C(R')-CHC(R')═O] (L(3)H, R' = Me; L(4)H, R' = Ph), with a donor-functionalized Lewis base have also been synthesized and used to form gallium and indium alkyl complexes, [Ga(L(3))Me(2)] (9) and [In(L(3))Me(2)] (10), which were isolated as oils. The related gallium hydride complexes, [Ga(L(n))H(2)] (11, n = 3; 12, n = 4), were also prepared, but again no indium hydride species could be made. The complexes were characterized mainly by NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction. The ß-ketoiminate gallium hydride compounds (8 and 11) have been used as single-source precursors for the deposition of Ga(2)O(3) by aerosol-assisted (AA)CVD with toluene as the solvent. The quality of the films varied according to the precursor used, with the complex [Ga(L(1))H] (8) giving by far the best quality films. Although the films were amorphous as deposited, they could be annealed at 1000 °C to form crystalline Ga(2)O(3). The films were analyzed by powder XRD, SEM, and EDX.

18.
Practitioner ; 256(1754): 25-8, 3, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23252133

RESUMO

Regular physical activity of moderate intensity can bring about major health benefits as well as significant cost savings for the NHS. Evidence suggests that regular exercise can produce up to a 30% reduction in all cause mortality with a 35% lower risk of cardiovascular disease, coronary heart disease and stroke. There is evidence to show that 37% of CHD deaths can be attributed to physical inactivity compared with 19% and 13% for smoking and hypertension respectively. In addition, a 40% reduction in the risk of metabolic syndrome and type 2 diabetes mellitus has been reported with moderate physical activity. Current guidelines from the CMO, for adults aged 19-64 years, recommend: 150 minutes of moderate intensity aerobic exercise per week such as fast walking or cycling plus muscle strengthening activities on two or more days a week, or 75 minutes of vigorous intensity aerobic activity such as running or singles tennis plus the same muscle strengthening regimen, or an equivalent mix of the two. Only 40% of men and 28% of women in England are achieving the recommended levels of exercise/physical activity. One way GPs can increase their patients' physical activity levels could be via an individualised tailored care pathway aiming to motivate individuals to make long-term health changes. Evidence suggests that the risks associated with physical activity at a level to promote health are low and that health benefits outweigh the risks. The 5 As system (Ask, Assess, Advise, Assist and Arrange) which is sometimes used in smoking cessation can be adapted for physical activity. Ask about the patient's current levels of physical activity using the General Practice Physical Activity Questionnaire; Assess their fitness and capabilities; Advise about appropriate exercise and the risks involved; Assist in locating places to get involved, use 'Let's Get Moving' and exercise referral schemes available; Arrange any necessary referrals.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Terapia por Exercício/métodos , Atividade Motora/fisiologia , Cooperação do Paciente , Aptidão Física/fisiologia , Humanos
19.
Syst Rev ; 11(1): 223, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36243764

RESUMO

BACKGROUND: The COVID-19 pandemic has disproportionately impacted homeless populations and service workers, especially within homeless shelter/hostel settings. To date, there have been few evidence syntheses examining outbreaks of COVID-19 among both homeless shelter residents and service workers and no critical review of infection control and prevention (IPAC) measures. This scoping review offers a much-needed synthesis of COVID-19 prevalence within homeless shelters and a review of pertinent IPAC measures.  METHODS: We conducted a scoping review that aimed to synthesize academic and gray literature published from March 2020 to July 2021 pertaining to (1) the prevalence of COVID-19 among both residents and staff in homeless shelters and hostels in high-income countries and (2) COVID-19 IPAC strategies applied in these settings. Two reviewers independently screened the literature from several databases that included MEDLINE, PsycInfo, and the WHO's COVID-19 Global Health Portal. The extracted data was mapped, categorized, and thematically discussed. RESULTS: Thematic analysis of 77 academic and gray literature documents revealed four key themes: (1) the demographics of COVID-19 in homeless shelters, (2) asymptomatic spread, (3) pre-existing vulnerability of people experiencing homelessness and shelters, and (4) the inconsistency and ineffectiveness of IPAC implementation. CONCLUSION: This review offers a useful glimpse into the landscape of COVID-19 outbreaks in homeless shelters/hostels and the major contributing factors to these events. This review revealed that there is no clear indication of generally accepted IPAC standards for shelter residents and workers. This review also illustrated a great need for future research to establish IPAC best practices specifically for homeless shelter/hostel contexts. Finally, the findings from this review reaffirm that homelessness prevention is key to limiting disease outbreaks and the associated negative health outcomes in shelter populations. Limitations of this review included the temporal and database constraints of the search strategy, the exclusion of quality assessments of the literature, and the absence of investigation on the influence of emerging variants on public health policy. SYSTEMATIC REVIEW REGISTRATION: This scoping review has not been registered on any database; the protocol is available on York University's Institutional Repository https://dx.doi.org/10.25071/10315/38513 .


Assuntos
COVID-19 , Pessoas Mal Alojadas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Países Desenvolvidos , Humanos , Controle de Infecções , Pandemias/prevenção & controle , Prevalência
20.
Dalton Trans ; 51(34): 13061-13070, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35972272

RESUMO

Air and moisture stable diaryl dithiocarbamate salts, Ar2NCS2Li, result from addition of CS2 to Ar2NLi, the latter being formed upon deprotonation of diarylamines by nBuLi. Oxidation with K3[Fe(CN)6] affords the analogous thiuram disulfides, (Ar2NCS2)2, two examples of which (Ar = p-C6H4X; X = Me, OMe) have been crystallographically characterised. The interconversion of dithiocarbamate and thiuram disulfides has also been probed electrochemically and compared with that established for the widely-utilised diethyl system. While oxidation reactions are generally clean and high yielding, for Ph(2-naphthyl)NCS2Li an ortho-cyclisation product, 3-phenylnaphtho[2,1-d]thiazole-2(3H)-thione, is also formed, resulting from a competitive intramolecular free-radical cyclisation. To demonstrate the coordinating ability of diaryl dithiocarbamates, a small series of Co(III) complexes have been prepared, with two examples, [Co{S2CN(p-tolyl)2}3] and [Co{S2CNPh(m-tolyl)}3] being crystallographically characterised. Solvothermal decomposition of [Co{S2CN(p-tolyl)2}3] in oleylamine generates phase pure CoS2 nanospheres in an unexpected phase-selective manner.

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