51
|
Smith KE, Stoops WW. Synthetic Cathinone Use Among Polysubstance Users: Indirect Indicator of Indiscriminate Drug Taking or Preferred Drug of Abuse? JOURNAL OF DRUG ISSUES 2019. [DOI: 10.1177/0022042619826079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A survey pertaining to synthetic cathinone (SC) use was completed by 499 polysubstance users enrolled in a residential recovery program in the Southeastern United States. Of the final sample, 28% reported ever SC use. SC-users, compared with nonusers, were more often younger (32.7 vs. 36.0, p = .001), White (93.4% vs. 80.8%, p = .001), and on probation/parole since 2010 (80.9% vs. 70.9%, p = .032). SC-users evidenced extensive drug histories and were less likely to be enrolled in an urban-based program, compared to a rural, Appalachian-based program (73.8% vs. 86.6%, p = .001). Use of synthetic cannabinoids (adjusted odds ratio [AOR] = 1.9, p = .044), kratom (AOR = 1.7, p = .045), and inhalants (AOR = 2.3, p = .001) were significantly associated with SC use. Approximately 23% of SC-users preferred SCs to amphetamines or cocaine; however, only 3.6% ranked SC as their most preferred drug. Past-year SC use declined to 6.6%. Among polysubstance users in this sample, SC use may be a potential indicator of versatile and indiscriminate drug-taking.
Collapse
|
52
|
Laverock J, Jovic V, Zakharov AA, Niu YR, Kittiwatanakul S, Westhenry B, Lu JW, Wolf SA, Smith KE. Observation of Weakened V-V Dimers in the Monoclinic Metallic Phase of Strained VO_{2}. PHYSICAL REVIEW LETTERS 2018; 121:256403. [PMID: 30608778 DOI: 10.1103/physrevlett.121.256403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/04/2018] [Indexed: 06/09/2023]
Abstract
Emergent order at mesoscopic length scales in condensed matter can provide fundamental insight into the underlying competing interactions and their relationship with the order parameter. Using spectromicroscopy, we show that mesoscopic stripe order near the metal-insulator transition (MIT) of strained VO_{2} represents periodic modulations in both crystal symmetry and V-V dimerization. Above the MIT, we unexpectedly find the long-range order of V-V dimer strength and crystal symmetry become dissociated beyond ≈200 nm, whereas the conductivity transition proceeds homogeneously in a narrow temperature range.
Collapse
|
53
|
Ellins EA, Smith KE, Lennon LT, Papacosta O, Wannamethee SG, Whincup PH, Halcox JP. Arterial pathophysiology and comparison of two devices for pulse wave velocity assessment in elderly men: the British regional heart study. Open Heart 2017; 4:e000645. [PMID: 29344365 PMCID: PMC5761282 DOI: 10.1136/openhrt-2017-000645] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 10/20/2017] [Accepted: 11/07/2017] [Indexed: 01/27/2023] Open
Abstract
Objective Vascular disease is highly prevalent in the elderly. This study aimed to evaluate arterial phenotype in elderly men and compare carotid–femoral pulse wave velocity (cfPWV) assessed by two techniques (Sphygmocor (S)and Vicorder (V)). Methods 1722 men (72–92 years), participants in the British Regional Heart Study, underwent ultrasound assessment of carotid intima–media thickness (cIMT), carotid distensibility coefficient and presence of carotid plaque. cfPWV and ankle brachial pressure index (ABPI) were also assessed. 123 men returned for between visit reproducibility assessments. Results Good reproducibility was demonstrated in all measures (Gwet’s agreement=0.8 for plaque, intraclass correlation=0.65 for ABPI and coefficient of variation <13% for all other measures). Measurements were obtained in >90% of men for all measures except cfPWV(S) and ABPI. In 1122 men with both cfPWV(V) and cfPWV(S) data, cfPWV(S) was greater than cfPWV(V) (mean difference=0.23,95%CI 0.10 to 0.37 m/s). cfPWV(V) was higher at low cfPWV values and cfPWV(S) was higher at high cfPWV values. Correlation of V transit time (TT) against S carotid and femoral TT demonstrated that the slope of the regression line for femoral TT was steeper than for carotid TT, resulting in a proportionally greater subtraction of carotid TT from femoral TT at higher PWVs. Conclusions Reproducible, satisfactory quality non-invasive measurements of vascular phenotype were obtainable in a large proportion of elderly men. The discrepancy in results between the two PWV measures may partly be due to the differential impact of subtracting carotid TT when deriving cfPWV(S) across the clinical PWV range.
Collapse
|
54
|
Hetrick SE, Bailey AP, Smith KE, Malla A, Mathias S, Singh SP, O'Reilly A, Verma SK, Benoit L, Fleming TM, Moro MR, Rickwood DJ, Duffy J, Eriksen T, Illback R, Fisher CA, McGorry PD. Integrated (one-stop shop) youth health care: best available evidence and future directions. Med J Aust 2017; 207:S5-S18. [PMID: 29129182 DOI: 10.5694/mja17.00694] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 09/26/2017] [Indexed: 01/07/2023]
Abstract
Although mental health problems represent the largest burden of disease in young people, access to mental health care has been poor for this group. Integrated youth health care services have been proposed as an innovative solution. Integrated care joins up physical health, mental health and social care services, ideally in one location, so that a young person receives holistic care in a coordinated way. It can be implemented in a range of ways. A review of the available literature identified a range of studies reporting the results of evaluation research into integrated care services. The best available data indicate that many young people who may not otherwise have sought help are accessing these mental health services, and there are promising outcomes for most in terms of symptomatic and functional recovery. Where evaluated, young people report having benefited from and being highly satisfied with these services. Some young people, such as those with more severe presenting symptoms and those who received fewer treatment sessions, have failed to benefit, indicating a need for further integration with more specialist care. Efforts are underway to articulate the standards and core features to which integrated care services should adhere, as well as to further evaluate outcomes. This will guide the ongoing development of best practice models of service delivery.
Collapse
|
55
|
Smith KE, Stewart EA. Academic advocacy in public health: Disciplinary 'duty' or political 'propaganda'? Soc Sci Med 2017; 189:35-43. [PMID: 28780438 DOI: 10.1016/j.socscimed.2017.07.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 07/17/2017] [Accepted: 07/20/2017] [Indexed: 01/26/2023]
Abstract
The role of 'advocacy' within public health attracts considerable debate but is rarely the subject of empirical research. This paper reviews the available literature and presents data from qualitative research (interviews and focus groups conducted in the UK in 2011-2013) involving 147 professionals (working in academia, the public sector, the third sector and policy settings) concerned with public health in the UK. It seeks to address the following questions: (i) What is public health advocacy and how does it relate to research?; (ii) What role (if any) do professionals concerned with public health feel researchers ought to play in advocacy?; and (iii) For those researchers who do engage in advocacy, what are the risks and challenges and to what extent can these be managed/mitigated? In answering these questions, we argue that two deeply contrasting conceptualisations of 'advocacy' exist within public health, the most dominant of which ('representational') centres on strategies for 'selling' public health goals to decision-makers and the wider public. This contrasts with an alternative (less widely employed) conceptualisation of advocacy as 'facilitational'. This approach focuses on working with communities whose voices are often unheard/ignored in policy to enable their views to contribute to debates. We argue that these divergent ways of thinking about advocacy speak to a more fundamental challenge regarding the role of the public in research, policy and practice and the activities that connect these various strands of public health research.
Collapse
|
56
|
Parsons TJ, Sartini C, Ellins EA, Halcox JPJ, Smith KE, Ash S, Lennon LT, Wannamethee SG, Lee IM, Whincup PH, Jefferis BJ. Objectively measured physical activity, sedentary time and subclinical vascular disease: Cross-sectional study in older British men. Prev Med 2016; 89:194-199. [PMID: 27261410 PMCID: PMC4976831 DOI: 10.1016/j.ypmed.2016.05.031] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 05/23/2016] [Accepted: 05/28/2016] [Indexed: 11/30/2022]
Abstract
Low physical activity (PA) and high levels of sedentary time (ST) are associated with higher cardiovascular disease (CVD) risk among older people. However, their independent contribution and importance of duration of PA and ST bouts remain unclear. We investigated associations between objectively measured PA, ST and non-invasive vascular measures, markers of CVD risk. Cross-sectional study of 1216 men from the British Regional Heart Study, mean age 78.5years, measured in 2010-2012. Carotid intima thickness (CIMT), distensibility coefficient (DC) and plaque presence were measured using ultrasound; pulse wave velocity (cfPWV) and augmentation index (AIx) using a Vicorder. PA and ST were measured using hip-worn ActiGraph GT3X accelerometers. After adjusting for covariates, each additional 1000 steps per day was associated with a 0.038m/s lower cfPWV (95% CI=-0.076, 0.0003), 0.095 10(-3) kPa(-1) higher DC (95% CI=0.006, 0.185), 0.26% lower AIx (95% CI=-0.40, -0.12) and a 0.005mm lower CIMT (95% CI=-0.008, -0.001). Moderate and vigorous PA (MVPA) was associated with lower AIx and CIMT, light PA (LPA) with lower cfPWV and CIMT and ST with higher cfPWV, AIx and CIMT and lower DC. LPA and ST were highly correlated (r=-0.62). The independence of MVPA and ST or MVPA and LPA was inconsistent across vascular measures. Bout lengths for both PA and ST were not associated with vascular measures. In our cross-sectional study of older men, all PA regardless of intensity or bout duration was beneficially associated with vascular measures, as was lower ST. LPA was particularly relevant for cfPWV and CIMT.
Collapse
|
57
|
Dickson MF, Staton-Tindall M, Smith KE, Leukefeld C, Webster JM, Oser CB. A Facebook Follow-Up Strategy for Rural Drug-Using Women. J Rural Health 2016; 33:250-256. [PMID: 27467119 DOI: 10.1111/jrh.12198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/21/2016] [Accepted: 06/24/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE Facebook (FB) use has grown exponentially over the past decade, including in rural areas. Despite its popularity, FB has been underutilized as a research follow-up approach to maintain contact with research participants and may have advantages in less densely populated areas and among more hard-to-reach, at-risk groups. The overall goal of this study was to examine FB as a supplemental follow-up approach to other follow-up strategies with rural drug-using women. METHODS Face-to-face interviews were conducted with randomly selected women who completed baseline interviews in 3 rural jails in 1 state. Analyses focus on participants who were released from jail and were eligible for 3-month follow-up (n = 284). Bivariate analyses were used to examine differences between FB users and nonusers, and multivariate logistic regression models examined predictors of 3-month follow-up participation and being located for follow-up using FB. FINDINGS About two-thirds (64.4%) of participants were regular FB users. Bivariate analyses indicated that FB users were younger, more educated, and more likely to have used alcohol in the 30 days before incarceration but less likely to have a chronic health problem. Regression analyses indicated that rural FB users had more than 5 times the odds of being located for the 3-month follow-up interview, even after controlling for other variables. There were no significant predictors of being followed up using FB. CONCLUSIONS Findings suggest that FB is widely used and well accepted among rural drug-using women. Among hard-to-reach populations, including those in rural, geographically isolated regions, FB serves as a method to improve participant follow-up.
Collapse
|
58
|
Ellins E, Smith KE, Lennon LT, Papacosta O, Wannamethee SG, Whincup PH, Halcox JP. NON-INVASIVE ASSESSMENT OF MYOCARDIAL PERFUSION IN ELDERLY MEN: THE IMPACT OF AORTIC STIFFNESS AND CENTRAL BLOOD PRESSURE. J Am Coll Cardiol 2016. [DOI: 10.1016/s0735-1097(16)31879-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
59
|
Parsons TJ, Sartini C, Ellins EA, Halcox JPJ, Smith KE, Ash S, Lennon LT, Wannamethee SG, Lee IM, Whincup PH, Jefferis BJ. Objectively measured physical activity and sedentary behaviour and ankle brachial index: Cross-sectional and longitudinal associations in older men. Atherosclerosis 2016; 247:28-34. [PMID: 26854973 PMCID: PMC4819952 DOI: 10.1016/j.atherosclerosis.2016.01.038] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 01/13/2016] [Accepted: 01/21/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Associations between bouts of physical activity (PA), sedentary behaviour (SB) and cardiovascular disease, and their mutual independence are not well defined. A low ankle brachial index (ABI ≤0.9) indicates peripheral arterial disease (PAD) and is predictive of cardiovascular events and functional impairment. We investigated the independence of PA and SB and the importance of bout duration in relation to ABI using objective measures. METHODS 945 men from the British Regional Heart Study, mean age 78.4 y, had concurrent measurements of ABI (Vicorder) and physical activity (Actigraph GT3X accelerometer); 427 men also had accelerometer measurements one year previously and contributed data to longitudinal analyses. RESULTS AND CONCLUSION In cross-sectional analyses, after adjusting for covariates each extra 10 min of moderate and vigorous PA per day was associated with an OR of 0.81 (95% CI 0.72, 0.91) for a low ABI, a stronger association than for light PA (OR 0.85, 95% CI 0.75, 0.98). Each extra 30 min of SB was associated with an OR of 1.19 (95% CI 1.07, 1.33) for a low ABI. Associations between moderate and vigorous PA and ABI persisted after adjustment for light PA or SB. Bout lengths for PA and SB were not associated with a low ABI. One year changes in PA or SB were not associated with low ABI. All physical activity and lower levels of SB, regardless of bout duration were inversely associated with ABI; more intense PA showed a stronger association. No associations between changes in PA and ABI were observed, but power may have been limited.
Collapse
|
60
|
|
61
|
Kapetanakis V, Smith KE, Papacosta O, Ellins EA, Lennon LT, Owen CG, Rudnicka AR, Halcox JP, Wannamethee SG, Whincup PH. OP80 Cardiovascular risk factors over the adult life course: associations with carotid intima-media thickness and carotid-femoral pulse wave velocity in older men in the british regional heart study. Br J Soc Med 2015. [DOI: 10.1136/jech-2015-206256.79] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
62
|
Amsler MO, Smith KE, McClintock JB, Singh H, Thatje S, Vos SC, Brothers CJ, Brown A, Ellis D, Anderson J, Aronson RB. In situ observations of a possible skate nursery off the western Antarctic Peninsula. JOURNAL OF FISH BIOLOGY 2015; 86:1867-1872. [PMID: 25898908 DOI: 10.1111/jfb.12679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 02/25/2015] [Indexed: 06/04/2023]
Abstract
A dense aggregation of skate egg cases was imaged during a photographic survey of the sea floor along the western Antarctic Peninsula in November 2013. Egg cases were noted in a narrow band between 394 and 443 m depth. Although some skate species in other oceans are known to utilize restricted areas to deposit eggs in great numbers, such nurseries have not been described in the Southern Ocean.
Collapse
|
63
|
Chen B, Laverock J, Newby D, McNulty JF, Smith KE, Glans PA, Guo JH, Qiao RM, Yang WL, Lees MR, Tung LD, Singh RP, Balakrishnan G. Effects of rare-earth size on the electronic structure of La1−xLuxVO3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:105503. [PMID: 25710627 DOI: 10.1088/0953-8984/27/10/105503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electronic structure of La(1-x)Lu(x)VO(3)(x = 0, 0.2, 0.6 and 1) single crystals has been investigated using soft x-ray absorption spectroscopy, soft x-ray emission spectroscopy, and resonant soft x-ray inelastic scattering to study the effects of rare-earth size. The x-ray absorption and emission spectra at the O K-edge present a progressive evolution with R-site cation, in agreement with local spin density approximation calculations. This evolution with R, together with the temperature dependence of the O K-edge spectra, is attributed to changes in the crystal structure of La(1-x)Lu(x)VO(3). The crystal-field dd. excitations probed by resonant inelastic x-ray scattering at the V L(3)-edge exhibit an increase in energy and enhanced intensity with the decrease of R-site ionic radius, which is mainly attributed to the increased tilting magnitude of the VO(6) octahedra. Upon cooling to ~95 K, the dd* excitations are prominently enhanced in relative Intensity, in agreement with the formation of the Jahn.Teller distortion int he orbital ordering phase. Additionally, the dd* transitions of the mixed compounds are noticeably suppressed with respect to those of the pure compounds, possibly owing to the formation of C-type orbital ordering induced by large R-site size variances.
Collapse
|
64
|
Laverock J, Kittiwatanakul S, Zakharov AA, Niu YR, Chen B, Wolf SA, Lu JW, Smith KE. Direct observation of decoupled structural and electronic transitions and an ambient pressure monocliniclike metallic phase of VO2. PHYSICAL REVIEW LETTERS 2014; 113:216402. [PMID: 25479508 DOI: 10.1103/physrevlett.113.216402] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Indexed: 06/04/2023]
Abstract
We report the simultaneous measurement of the structural and electronic components of the metal-insulator transition (MIT) of VO2 using electron and photoelectron spectroscopies and microscopies. We show that these evolve over different temperature scales, and are separated by an unusual monocliniclike metallic phase. Our results provide conclusive evidence that the new monocliniclike metallic phase, recently identified in high-pressure and nonequilibrium measurements, is accessible in the thermodynamic transition at ambient pressure, and we discuss the implications of these observations on the nature of the MIT in VO2.
Collapse
|
65
|
Laverock J, Chen B, Preston ARH, Newby D, Piper LFJ, Tung LD, Balakrishnan G, Glans PA, Guo JH, Smith KE. Low-energy V t2g orbital excitations in NdVO3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:455603. [PMID: 25336521 DOI: 10.1088/0953-8984/26/45/455603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electronic structure of NdVO(3) and YVO(3) has been investigated as a function of sample temperature using resonant inelastic soft x-ray scattering at the V L(3)-edge. Most of the observed spectral features are in good agreement with an atomic crystal-field multiplet model. However, a low energy feature is observed at ∼ 0.4 eV that cannot be explained by crystal-field arguments. The resonant behaviour of this feature establishes it as due to excitations of the V t(2g) states. Moreover, this feature exhibits a strong sample temperature dependence, reaching maximum intensity in the orbitally-ordered phase of NdVO(3), before becoming suppressed at low temperatures. This behaviour indicates that the origin of this feature is a collective orbital excitation, i.e. the bi-orbiton.
Collapse
|
66
|
Cho SW, Newby D, DeMasi A, Smith KE, Piper LFJ, Jones TS. Determination of the individual atomic site contribution to the electronic structure of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA). J Chem Phys 2013; 139:184711. [PMID: 24320295 DOI: 10.1063/1.4829764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have studied the element and orbital-specific electronic structure of thin films of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) using a combination of synchrotron radiation-exited resonant x-ray emission spectroscopy, x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, as well as density functional theory calculations. Resonant and non-resonant x-ray emission spectroscopies were used to measure the C and O 2p partial densities of state in PTCDA. Furthermore, resonant x-ray emission at the C and O K-edges is shown to be able to measure the partial densities of states associated with individual atomic sites. The flat molecular orientation of PTCDA on various substrates is explained in terms of the carbonyl O atom acting as a hydrogen-bond acceptor leading to multiple in-plane intermolecular C=O···H-C hydrogen bonding between carbonyl groups and the perylene core of the neighboring PTCDA molecules. We support this conclusion by comparison of our calculations to measurements of the electronic structure using element-, site-, and orbital-selective C and O K-edge resonant x-ray emission spectroscopy, and photoemission spectroscopy.
Collapse
|
67
|
Laverock J, Chen B, Smith KE, Singh RP, Balakrishnan G, Gu M, Lu JW, Wolf SA, Qiao RM, Yang W, Adell J. Resonant soft-X-ray emission as a bulk probe of correlated electron behavior in metallic SrxCa1-xVO3. PHYSICAL REVIEW LETTERS 2013; 111:047402. [PMID: 23931404 DOI: 10.1103/physrevlett.111.047402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Indexed: 06/02/2023]
Abstract
The evolution of electron correlation in SrxCa1-xVO3 has been studied using a combination of bulk-sensitive resonant soft x-ray emission spectroscopy, surface-sensitive photoemission spectroscopy, and ab initio band structure calculations. We show that the effect of electron correlation is enhanced at the surface. Strong incoherent Hubbard subbands are found to lie ∼20% closer in energy to the coherent quasiparticle features in surface-sensitive photoemission spectroscopy measurements compared with those from bulk-sensitive resonant soft x-ray emission spectroscopy, and a ∼10% narrowing of the overall bandwidth at the surface is also observed.
Collapse
|
68
|
Chen B, Laverock J, Piper LFJ, Preston ARH, Cho SW, DeMasi A, Smith KE, Scanlon DO, Watson GW, Egdell RG, Glans PA, Guo JH. The band structure of WO3 and non-rigid-band behaviour in Na0.67WO3 derived from soft x-ray spectroscopy and density functional theory. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:165501. [PMID: 23553445 DOI: 10.1088/0953-8984/25/16/165501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The electronic structure of single-crystal WO3 and Na0.67WO3 (a sodium-tungsten bronze) has been measured using soft x-ray absorption and resonant soft x-ray emission oxygen K-edge spectroscopies. The spectral features show clear differences in energy and intensity between WO3 and Na0.67WO3. The x-ray emission spectrum of metallic Na0.67WO3 terminates in a distinct Fermi edge. The rigid-band model fails to explain the electronic structure of Na0.67WO3 in terms of a simple addition of electrons to the conduction band of WO3. Instead, Na bonding and Na 3s-O 2p hybridization need to be considered for the sodium-tungsten bronze, along with occupation of the bottom of the conduction band. Furthermore, the anisotropy in the band structure of monoclinic γ-WO3 revealed by the experimental spectra with orbital-resolved geometry is explained via density functional theory calculations. For γ-WO3 itself, good agreement is found between the experimental O K-edge spectra and the theoretical partial density of states of O 2p orbitals. Indirect and direct bandgaps of insulating WO3 are determined from extrapolating separations between spectral leading edges and accounting for the core-hole energy shift in the absorption process. The O 2p non-bonding states show upward band dispersion as a function of incident photon energy for both compounds, which is explained using the calculated band structure and experimental geometry.
Collapse
|
69
|
Smith KE, Whiting BR, Reiker GG, Commean PK, Sinacore DR, Prior FW. Assessment of technical and biological parameters of volumetric quantitative computed tomography of the foot: a phantom study. Osteoporos Int 2012; 23:1977-85. [PMID: 22147208 PMCID: PMC3339281 DOI: 10.1007/s00198-011-1851-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 09/12/2011] [Indexed: 11/29/2022]
Abstract
SUMMARY Few studies exist for bone densitometry of the whole foot. A phantom study demonstrated the sources of error and necessary controls for accurate quantitative computed tomography of the foot. A loss in bone mineral density (BMD) in the small foot bones may be an early indicator of diabetic foot complications. INTRODUCTION Volumetric quantitative computed tomography (vQCT) facilitates the assessment of pedal bone osteopenia, which, in the presence of peripheral neuropathy, may well be an early sign of diabetic foot deformity. To date, sources and magnitudes of error in foot vQCT measurements have not been reported. METHODS Foot phantoms were scanned using a 64-slice CT scanner. Energy (in kilovoltage peak), table height, phantom size and orientation, location of "bone" inserts, insert material, location of calibration phantom, and reconstruction kernel were systematically varied during scan acquisition. RESULTS Energy (in kilovoltage peak) and distance from the isocenter (table height) resulted in relative attenuation changes from -5% to 22% and -5% to 0%, respectively, and average BMD changes from -0.9% to 0.0% and -1.1% to 0.3%, respectively, compared to a baseline 120-kVp scan performed at the isocenter. BMD compared to manufacturer-specified values ranged, on average, from -2.2% to 0.9%. Phantom size and location of bone-equivalent material inserts resulted in relative attenuation changes of -1.2% to 1.4% compared to the medium-sized phantom. CONCLUSION This study demonstrated that variations in kilovoltage peak and table height can be controlled using a calibration phantom scanned at the same energy and height as a foot phantom; however, error due to soft tissue thickness and location of bones within a foot cannot be controlled using a calibration phantom alone.
Collapse
|
70
|
Smith KE, Gilmore AB, Fooks G, Collin J, Weishaar H. Tobacco industry attempts to undermine Article 5.3 and the "good governance" trap. Tob Control 2010; 18:509-11. [PMID: 19955541 DOI: 10.1136/tc.2009.032300] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
71
|
Smith KE, Ravikumar N, Hession M, Morrison JJ. Trends in the obstetric features and management of twin pregnancies. IRISH MEDICAL JOURNAL 2010; 103:70-72. [PMID: 20666067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
There are no reports outlining the trends in obstetric features and clinical management of twin pregnancies in an Irish obstetric population. The aim of this study was to investigate these factors for all twin pregnancies delivered during the 19 year period between 1989 and 2007, at Galway University Hospital (GUH). There were 52,199 infants delivered at GUH, of which 1594 infants (3.05% of births) were twins, related to 797 twin pregnancies. The overall incidence of twin pregnancies was 1.52%, increasing from 0.8%-1.0% in the early years of the study to 1.7-1.8% in the latter years of the study (P<0.001). There was a significant increase in incidence of twins born to mothers aged 30-39 years, alongside a significant reduction to mothers aged 20-29 years (P<0.01). The caesarean section rate overall was 41.5% (331/797), of which 54% (n=179) were elective, and 46% (n=152) were emergency, representing an emergency caesarean section rate of 19.1% of all twin pregnancies, and of 24.6% after exclusion of elective caesarean sections. The caesarean section rate for twins increased from 30% in 1989 to greater than 50% in the latter years of the study (P<0.01), related largely to a significant increase in elective caesarean sections (P<0.01). The combined vaginal-caesarean delivery rate was remarkably low at 0.75% of all twin pregnancies, and 1% after exclusion of elective caesarean sections. The preterm delivery rates were 4.1% (<32 weeks), and 16.3% (<36 weeks), with an overall perinatal mortality rate of 37 per 1000. These findings highlight the altered demographic and clinical aspects of twin pregnancies in an Irish obstetric population.
Collapse
|
72
|
Joyce KE, Smith KE, Henderson G, Greig G, Bambra C. Patient perspectives of Condition Management Programmes as a route to better health, well-being and employability. Fam Pract 2010; 27:101-9. [PMID: 19948563 DOI: 10.1093/fampra/cmp083] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Condition Management Programmes (CMPs), delivered through primary care settings, have been identified as possible vehicles to facilitate return to work for individuals with chronic health problems. There is little research, however, which examines how such programmes are received by patients. OBJECTIVE To explore patients' experiences of CMPs in terms of health, well-being and employability. METHODS Four focus groups and nine semi-structured interviews were conducted in order to capture patients' (n = 25) perceptions and experiences regarding participation in one of five different CMPs: Cardiac Rehabilitation, Counselling, Lower Back Pain Services, Smoking Cessation and a GP Exercise Referral Programme. RESULTS Experiences of the CMPs were generally positive. Respondents reported improved health behaviours (specifically better diets and increased exercise), positive psychosocial outcomes (including increased self-esteem, confidence and social support) and in some cases, return to work. However, concerns were expressed about the shortness of interventions and their accessibility. CONCLUSIONS Although condition management appears to have been well received by participants, the findings also illustrate that there is no 'one size fits all' template for CMPs. Rather, interventions should be adapted to take account of the dynamics of specific conditions, the context in which the intervention is based and the characteristics of the individuals involved.
Collapse
|
73
|
Learmonth T, Glans PA, Guo JH, Greenblatt M, Smith KE. Electronic excitations in the correlated metal BaV(0.98)Ti(0.02)S(3) studied using resonant inelastic soft x-ray scattering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:025504. [PMID: 21386258 DOI: 10.1088/0953-8984/22/2/025504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Electronic excitations in the correlated metal BaTi(0.02)V(0.98)S(3) have been studied using resonant inelastic soft x-ray scattering at the V L edge. The intensities of the intra-atomic d-d(*) excitations and the elastic x-ray scattering feature are found to be temperature dependent, with the intensity increasing with decreasing temperature until saturation is reached near 100 K. The behavior of the spectral features is interpreted as evidence of a shift in the 3d electrons from more band-like states at higher temperature to more localized states at low temperature.
Collapse
|
74
|
Jeong HK, Noh HJ, Kim JY, Colakerol L, Glans PA, Jin MH, Smith KE, Lee YH. Comment on "Near-edge X-ray absorption fine-structure investigation of graphene". PHYSICAL REVIEW LETTERS 2009; 102:099701-099702. [PMID: 19392571 DOI: 10.1103/physrevlett.102.099701] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Indexed: 05/27/2023]
Abstract
A Comment on the Letter by D. Pacilé et al., Phys. Rev. Lett. 101, 066806 (2008)10.1103/PhysRevLett.101.066806. The authors of the Letter offer a Reply.
Collapse
|
75
|
DeMasi A, Piper LFJ, Zhang Y, Reid I, Wang S, Smith KE, Downes JE, Peltekis N, McGuinness C, Matsuura A. Electronic structure of the organic semiconductor Alq3 (aluminum tris-8-hydroxyquinoline) from soft x-ray spectroscopies and density functional theory calculations. J Chem Phys 2009; 129:224705. [PMID: 19071937 DOI: 10.1063/1.3030975] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The element-specific electronic structure of the organic semiconductor aluminum tris-8-hydroxyquinoline (Alq(3)) has been studied using a combination of resonant x-ray emission spectroscopy, x-ray photoelectron spectroscopy, x-ray absorption spectroscopy, and density functional theory (DFT) calculations. Resonant and nonresonant x-ray emission spectroscopy were used to measure directly the carbon, nitrogen and oxygen 2p partial densities of states in Alq(3), and good agreement was found with the results of DFT calculations. Furthermore, resonant x-ray emission at the carbon K-edge is shown to be able to measure the partial density of states associated with individual C sites. Finally, comparison of previous x-ray emission studies and the present data reveal the presence of clear photon-induced damage in the former.
Collapse
|