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Kaur Kohli R, Salas S, Shokoor B, Price CL, Davies JF. Chemically Resolved Evaporation Dynamics of Dicarboxylic Acid Mixtures in Solid Particles. Anal Chem 2023. [PMID: 37490783 DOI: 10.1021/acs.analchem.3c02475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
The evaporation rate and corresponding vapor pressure of dicarboxylic acids have been the subject of numerous scientific studies over the years, with reported values spanning several orders of magnitude. Recent work has identified the importance of considering the phase state of the material during evaporation, likely accounting for some of the variability in measured vapor pressures. In the homologous series of dicarboxylic acids, the phase state under dry conditions may be crystalline or amorphous, with particles of odd-carbon-numbered acids exhibiting tendencies to remain amorphous and spherical. Although measurements of vapor pressures for pure components make up most of the available literature data, for many applications, these compounds are not present in isolation. Additionally, many systems containing a semi-volatile material exist in a solid state, especially under dry and low relative humidity conditions. In this work, we explore the evaporation of compounds present in mixed solid-state particles. Specifically, we use single particle levitation coupled with mass spectrometry to measure the evolving composition of solid particles containing mixtures of glutaric acid and succinic acid, glutaric acid and adipic acid, and malonic acid and succinic acid. Under dry conditions, these systems exhibit non-spherical geometries consistent with crystallization of one or both components into an organic crystal. Our measurements allow the evaporation of each component in the mixture to be characterized independently and effective vapor pressures of the pure components to be inferred. The resulting vapor pressures are compared against pure component vapor pressures. We demonstrate that these mixtures exhibit thermodynamic ideality but can be influenced by limited diffusion in the solid phase. These are the first results in the literature that explore the thermodynamic and kinetic factors that control the evaporative evolution of mixed solid-state particles.
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Affiliation(s)
- Ravleen Kaur Kohli
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Stephanie Salas
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Bilal Shokoor
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Chelsea L Price
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - James F Davies
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
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Price CL, Kaur Kohli R, Shokoor B, Davies JF. Connecting the Phase State and Volatility of Dicarboxylic Acids at Elevated Temperatures. J Phys Chem A 2022; 126:6963-6972. [PMID: 36150212 DOI: 10.1021/acs.jpca.2c04546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The partitioning of semivolatile organic molecules between condensed phases and the vapor phase has broad application across a range of scientific disciplines, with significant impacts in atmospheric chemistry for regulating the evolving composition of aerosol particles. Vapor partitioning depends on the molecular interactions and phase state of the condensed material and shows a well-established dependence on temperature. The phase state of solid organic material is not always well-defined, and many examples can be found for the formation of amorphous subcooled liquid states rather than crystalline solids. This can lead to significant changes to vapor equilibrium processes by modifying the thermodynamics and kinetics of evaporation. Here, we explore the influence of phase state on the evaporation dynamics of a series of straight-chain dicarboxylic acids across a range of above-ambient temperatures. These molecules show an odd/even alteration in some of their properties based on the number of carbon atoms that may be connected to their phase state under dry conditions. Using a newly developed linear-quadrupole electrodynamic balance, we levitate single particles containing the sample and expose them to dry conditions across a range of temperatures (ambient to ∼350 K). Using the rate of evaporation measured from the change in the size or relative mass, we derive the vapor pressure and enthalpy of vaporization. Light scattering data allows for unambiguous identification of the phase of the particles (crystal vs amorphous) allowing the vapor equilibrium properties to be attributed to a particular state. This work highlights a new experimental method for characterizing vapor pressures of low volatility substances and extends the temperature range of available data for the vapor pressure of terminal dicarboxylic acids. These measurements show that crystalline and subcooled liquid states persist at elevated temperatures and provide a direct comparison between subcooled and crystal phases under the same experimental conditions.
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Affiliation(s)
- Chelsea L Price
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Ravleen Kaur Kohli
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Bilal Shokoor
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - James F Davies
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
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Price CL, Preston TC, Davies JF. Hygroscopic Growth, Phase Morphology, and Optical Properties of Model Aqueous Brown Carbon Aerosol. Environ Sci Technol 2022; 56:3941-3951. [PMID: 35312301 DOI: 10.1021/acs.est.1c07356] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Brown carbon aerosol in the atmosphere contain light-absorbing chromophores that influence the optical scattering properties of the particles. These chromophores may be hydrophobic, such as PAHs, or water soluble, such as nitroaromatics, imidazoles, and other conjugated oxygen-rich molecules. Water-soluble chromophores are expected to exist in aqueous solution in the presence of sufficient water and will exhibit physical properties (e.g., size, refractive index, and phase morphology) that depend on the environmental relative humidity (RH). In this work, we characterize the RH-dependent properties of 4-nitrocatechol (4-NC) and its mixtures with ammonium sulfate, utilizing a single-particle levitation platform coupled with Mie resonance spectroscopy to probe the size, real part of the complex refractive index (RI), and phase morphology of individual micron-sized particles. We measure the hygroscopic growth properties of pure 4-NC and apply mixing rules to characterize the growth of mixtures with ammonium sulfate. We report the RI at 589 nm for these samples as a function of RH and explore the wavelength dependence of the RI at non-absorbing wavelengths. The real part of the RI at 589 nm was found to vary in the range 1.54-1.59 for pure 4-NC from 92.5 to 75% RH, with an estimated pure component RI of 1.70. The real part of the RI was also measured for mixtures of AS and 4-NC and ranged from 1.39 to 1.51 depending on the component ratio and RH. We went on to characterize phase transitions in mixed particles, identifying the onset RH of liquid-liquid phase separation (LLPS) and efflorescence transitions. Mixtures showed LLPS in the range of 85-76% RH depending on the molar ratio, while efflorescence typically fell between 22 and 42% RH. Finally, we characterized the imaginary part of the complex RI using an effective oscillator model to capture the wavelength-dependent absorption properties of the system.
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Affiliation(s)
- Chelsea L Price
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
| | - Thomas C Preston
- Department of Atmospheric and Oceanic Sciences and Department of Chemistry, McGill University, 805 Sherbrooke Street West, Montreal, Quebec H3A 0B9, Canada
| | - James F Davies
- Department of Chemistry, University of California Riverside, Riverside, California 92521, United States
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Davies JF, Price CL, Choczynski J, Kohli RK. Hygroscopic growth of simulated lung fluid aerosol particles under ambient environmental conditions. Chem Commun (Camb) 2021; 57:3243-3246. [PMID: 33646231 DOI: 10.1039/d1cc00066g] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hygroscopicity of respiratory aerosol determines their particle size distribution and regulates solute concentrations to which entrained microorganisms are exposed. Here, we report the hygroscopicity of simulated lung fluid (SLF) particles. While the response of aqueous particles follow simple mixing rules based on composition, we observe phase hysteresis with increasing and decreasing relative humidity (RH) and clear uptake of water prior to deliquescence. These results indicate that RH history may control the state of respiratory aerosol in the environment and influence the viability of microorganisms.
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Affiliation(s)
- James F Davies
- Department of Chemistry, University of California Riverside, Riverside, CA 92521, USA.
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Abstract
Condensed phase mass transport in single aerosol particles is investigated using a linear quadrupole electrodynamic balance (LQ-EDB) and the Maxwell–Stefan (MS) framework.
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Affiliation(s)
- Brandon J. Wallace
- Department of Atmospheric and Oceanic Sciences
- Department of Chemistry
- McGill University
- Montreal
- Canada
| | - Chelsea L. Price
- Department of Chemistry
- University of California Riverside
- Riverside
- USA
| | - James F. Davies
- Department of Chemistry
- University of California Riverside
- Riverside
- USA
| | - Thomas C. Preston
- Department of Atmospheric and Oceanic Sciences
- Department of Chemistry
- McGill University
- Montreal
- Canada
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Richards DS, Trobaugh KL, Hajek-Herrera J, Price CL, Sheldon CS, Davies JF, Davis RD. Ion-molecule interactions enable unexpected phase transitions in organic-inorganic aerosol. Sci Adv 2020; 6:6/47/eabb5643. [PMID: 33208357 PMCID: PMC7673807 DOI: 10.1126/sciadv.abb5643] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 10/07/2020] [Indexed: 05/17/2023]
Abstract
Atmospheric aerosol particles are commonly complex, aqueous organic-inorganic mixtures, and accurately predicting the properties of these particles is essential for air quality and climate projections. The prevailing assumption is that aqueous organic-inorganic aerosols exist predominately with liquid properties and that the hygroscopic inorganic fraction lowers aerosol viscosity relative to the organic fraction alone. Here, in contrast to those assumptions, we demonstrate that increasing inorganic fraction can increase aerosol viscosity (relative to predictions) and enable a humidity-dependent gel phase transition through cooperative ion-molecule interactions that give rise to long-range networks of atmospherically relevant low-mass oxygenated organic molecules (180 to 310 Da) and divalent inorganic ions. This supramolecular, ion-molecule effect can drastically influence the phase and physical properties of organic-inorganic aerosol and suggests that aerosol may be (semi)solid under more conditions than currently predicted. These observations, thus, have implications for air quality and climate that are not fully represented in atmospheric models.
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Affiliation(s)
- David S Richards
- Department of Chemistry, Trinity University, 1 Trinity Place, San Antonio, TX 78212, USA
| | - Kristin L Trobaugh
- Department of Chemistry, Trinity University, 1 Trinity Place, San Antonio, TX 78212, USA
| | - Josefina Hajek-Herrera
- Department of Chemistry, Trinity University, 1 Trinity Place, San Antonio, TX 78212, USA
| | - Chelsea L Price
- Department of Chemistry, University of California-Riverside, Riverside, CA 92521, USA
| | - Craig S Sheldon
- Department of Chemistry, University of California-Riverside, Riverside, CA 92521, USA
| | - James F Davies
- Department of Chemistry, University of California-Riverside, Riverside, CA 92521, USA
| | - Ryan D Davis
- Department of Chemistry, Trinity University, 1 Trinity Place, San Antonio, TX 78212, USA.
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Price CL, Bain A, Wallace BJ, Preston TC, Davies JF. Simultaneous Retrieval of the Size and Refractive Index of Suspended Droplets in a Linear Quadrupole Electrodynamic Balance. J Phys Chem A 2020; 124:1811-1820. [PMID: 32013433 DOI: 10.1021/acs.jpca.9b10748] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Single-particle trapping is an effective strategy to explore the physical and optical properties of aerosol with high precision. Laser-based methods are commonly used to probe the size, optical properties, and composition of nonlight-absorbing droplets in optical and electrodynamic traps. However, these methods cannot be applied to droplets containing photoactive chromophores, and thus, single-particle methods have been restricted to only a subset of atmospherically relevant particle compositions. In this work, we explore the application of a broadband light scattering approach, Mie resonance spectroscopy, to simultaneously probe the size and the refractive index (RI) of droplets in a linear quadrupole electrodynamic balance. We examine the evaporation of poly(ethylene glycol)s and compare the calculated vapor pressures with literature values to benchmark the size accuracy without prior constraint on the RI. We then explore the hygroscopic growth and deliquescence of sodium chloride droplets, measuring RI at the deliquescence relative humidity and demonstrating agreement to literature values. These data allow the wavelength dependence of the RI of aqueous NaCl to be determined using a first-order Cauchy equation, and we effectively reproduce literature data from multiple techniques. We finally discuss measurements from a light-absorbing aqueous droplet containing humic acid and interpret the spectra via the imaginary component of the RI. The approach described here allows the radius of nonabsorbing droplets to be determined within 0.1%, the refractive index within 0.2%, and the first-order term in the Cauchy dispersion equation within ∼5%.
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Affiliation(s)
- Chelsea L Price
- Department of Chemistry, University of California Riverside, Riverside, California 92420, United States
| | - Alison Bain
- Department of Atmospheric and Oceanic Sciences and Department of Chemistry, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - Brandon J Wallace
- Department of Atmospheric and Oceanic Sciences and Department of Chemistry, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - Thomas C Preston
- Department of Atmospheric and Oceanic Sciences and Department of Chemistry, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - James F Davies
- Department of Chemistry, University of California Riverside, Riverside, California 92420, United States
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Price CL, Brace-McDonnell SJ, Stallard N, Bleetman A, Maconochie I, Perkins GD. Performance characteristics of five triage tools for major incidents involving traumatic injuries to children. Injury 2016; 47:988-92. [PMID: 26653268 DOI: 10.1016/j.injury.2015.10.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 10/27/2015] [Accepted: 10/31/2015] [Indexed: 02/02/2023]
Abstract
UNLABELLED Context Triage tools are an essential component of the emergency response to a major incident. Although fortunately rare, mass casualty incidents involving children are possible which mandate reliable triage tools to determine the priority of treatment. OBJECTIVE To determine the performance characteristics of five major incident triage tools amongst paediatric casualties who have sustained traumatic injuries. DESIGN, SETTING, PARTICIPANTS Retrospective observational cohort study using data from 31,292 patients aged less than 16 years who sustained a traumatic injury. Data were obtained from the UK Trauma Audit and Research Network (TARN) database. Interventions Statistical evaluation of five triage tools (JumpSTART, START, CareFlight, Paediatric Triage Tape/Sieve and Triage Sort) to predict death or severe traumatic injury (injury severity score >15). Main outcome measures Performance characteristics of triage tools (sensitivity, specificity and level of agreement between triage tools) to identify patients at high risk of death or severe injury. RESULTS Of the 31,292 cases, 1029 died (3.3%), 6842 (21.9%) had major trauma (defined by an injury severity score >15) and 14,711 (47%) were aged 8 years or younger. There was variation in the performance accuracy of the tools to predict major trauma or death (sensitivities ranging between 36.4 and 96.2%; specificities 66.0-89.8%). Performance characteristics varied with the age of the child. CareFlight had the best overall performance at predicting death, with the following sensitivity and specificity (95% CI) respectively: 95.3% (93.8-96.8) and 80.4% (80.0-80.9). JumpSTART was superior for the triaging of children under 8 years; sensitivity and specificity (95% CI) respectively: 86.3% (83.1-89.5) and 84.8% (84.2-85.5). The triage tools were generally better at identifying patients who would die than those with non-fatal severe injury. CONCLUSION This statistical evaluation has demonstrated variability in the accuracy of triage tools at predicting outcomes for children who sustain traumatic injuries. No single tool performed consistently well across all evaluated scenarios.
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Affiliation(s)
- C L Price
- Operational Research and Management Sciences Group (ORMS), Warwick Business School, University of Warwick, Coventry CV4 7AL, UK.
| | - S J Brace-McDonnell
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK; Heart of England NHS Foundation Trust, Bordesley Green East, Birmingham B9 5SS, UK
| | - N Stallard
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - A Bleetman
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - I Maconochie
- Imperial College NHS Healthcare Trust, London W2 1NY, UK; The Trauma Audit & Research Network, Manchester Medical Academic Health Sciences Centre, University of Manchester, 3rd Floor, the Mayo Building, Salford Royal NHS Foundation Trust, Stott Lane, Salford M6 8HD, UK
| | - G D Perkins
- Division of Health Sciences, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK; Heart of England NHS Foundation Trust, Bordesley Green East, Birmingham B9 5SS, UK
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Parsons NR, Hiskens R, Price CL, Achten J, Costa ML. A systematic survey of the quality of research reporting in general orthopaedic journals. ACTA ACUST UNITED AC 2011; 93:1154-9. [PMID: 21911523 DOI: 10.1302/0301-620x.93b9.27193] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The poor reporting and use of statistical methods in orthopaedic papers has been widely discussed by both clinicians and statisticians. A detailed review of research published in general orthopaedic journals was undertaken to assess the quality of experimental design, statistical analysis and reporting. A representative sample of 100 papers was assessed for compliance to CONSORT and STROBE guidelines and the quality of the statistical reporting was assessed using a validated questionnaire. Overall compliance with CONSORT and STROBE guidelines in our study was 59% and 58% respectively, with very few papers fulfilling all criteria. In 37% of papers patient numbers were inadequately reported; 20% of papers introduced new statistical methods in the 'results' section not previously reported in the 'methods' section, and 23% of papers reported no measurement of error with the main outcome measure. Taken together, these issues indicate a general lack of statistical rigour and are consistent with similar reviews undertaken in a number of other scientific and clinical research disciplines. It is imperative that the orthopaedic research community strives to improve the quality of reporting; a failure to do so could seriously limit the development of future research.
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Affiliation(s)
- N R Parsons
- University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry, CV2 2DX, UK.
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Ng SC, Benjamin JL, McCarthy NE, Hedin CRH, Koutsoumpas A, Plamondon S, Price CL, Hart AL, Kamm MA, Forbes A, Knight SC, Lindsay JO, Whelan K, Stagg AJ. Relationship between human intestinal dendritic cells, gut microbiota, and disease activity in Crohn's disease. Inflamm Bowel Dis 2011; 17:2027-37. [PMID: 21910165 DOI: 10.1002/ibd.21590] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2010] [Accepted: 10/29/2010] [Indexed: 12/11/2022]
Abstract
BACKGROUND Altered intestinal dendritic cell (DC) function underlies dysregulated T-cell responses to bacteria in Crohn's disease (CD) but it is unclear whether composition of the intestinal microbiota impacts local DC function. We assessed the relationship between DC function with disease activity and intestinal microbiota in patients with CD. METHODS Surface expression of Toll-like receptor (TLR)-2, TLR-4, and spontaneous intracellular interleukin (IL)-10, IL-12p40, IL-6 production by freshly isolated DC were analyzed by multicolor flow cytometry of cells extracted from rectal tissue of 10 controls and 28 CD patients. Myeloid DC were identified as CD11c(+) HLA-DR(+lin-/dim) cells (lin = anti-CD3, CD14, CD16, CD19, CD34). Intestinal microbiota were analyzed by fluorescent in situ hybridization of fecal samples with oligonucleotide probes targeting 16S rRNA of bifidobacteria, bacteroides-prevotella, C. coccoides-E. rectale, and Faecalibacterium prausnitzii. RESULTS DC from CD produced higher amounts of IL-12p40 and IL-6 than control DC. IL-6(+) DC were associated with the CD Activity Index (r = 0.425; P = 0.024) and serum C-reactive protein (CRP) (r = 0.643; P = 0.004). DC expression of TLR-4 correlated with disease activity. IL-12p40(+) DC correlated with ratio of bacteroides: bifidobacteria (r = 0.535, P = 0.003). IL-10(+) DC correlated with bifidobacteria, and IL-6(+) DC correlated negatively with F. prausnitzii (r = -0.50; P = 0.008). The amount of TLR-4 on DC correlated negatively with the concentration of F. prausnitzii. CONCLUSIONS IL-6 production by intestinal DC is increased in CD and correlates with disease activity and CRP. Bacterially driven local IL-6 production by intestinal DC may overcome regulatory activity, resulting in unopposed effector function and tissue damage. Intestinal DC function may be influenced by the composition of the commensal microbiota.
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Affiliation(s)
- S C Ng
- Antigen Presentation Research Group, Imperial College London, St Mark's Hospital, London, UK
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Goulding JMR, Price CL, Defty CL, Hulangamuwa CS, Bader E, Ahmed I. Erectile dysfunction in patients with psoriasis: increased prevalence, an unmet need, and a chance to intervene. Br J Dermatol 2010; 164:103-9. [PMID: 20874856 DOI: 10.1111/j.1365-2133.2010.10077.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Male erectile dysfunction (ED) is common, frequently caused by pelvic arterial atherosclerosis, and is a predictor of future cardiovascular disease. There is an emerging association between psoriasis, the metabolic syndrome and atherosclerotic disease. We hypothesized that ED occurs more commonly in patients with psoriasis, at least in part due to incipient atherosclerosis, which may offer an opportunity for early intervention. OBJECTIVES To determine the prevalence of, and risk factors for, ED in patients with psoriasis in comparison with a heterogeneous dermatology outpatient control group. METHODS We conducted a pilot study with a prospective observational cross-sectional design, recruiting consecutive adult male dermatology outpatients diagnosed with psoriasis or any other skin condition. Sexually active participants completed a questionnaire, a Dermatology Life Quality Index and the validated five-item version of the International Index of Erectile Function (IIEF-5). RESULTS Fifty-three of 92 (58%) patients with psoriasis recorded an IIEF-5 score indicative of ED, compared with 64 of 130 (49%) control patients, reflecting an age-adjusted odds ratio of 2·007 (95% confidence interval 1·088-3·701; P = 0·026). A multivariable logistic regression model indicated that increasing age and hypertension, but not a diagnosis of psoriasis, were independent risk factors for ED in our study population. CONCLUSIONS We present the largest survey of ED in patients with skin disease, and the first to posit the potential link between psoriasis, ED and atherosclerosis. We suggest that an assessment of sexual function should be part of the routine holistic care provided for dermatology outpatients, and highlight the need to screen for cardiovascular risk factors in those with documented ED.
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Affiliation(s)
- J M R Goulding
- Department of Dermatology, University Hospital, Clifford Bridge Road, Walsgrave, Coventry CV2 2DX, UK.
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Abstract
Atherosclerosis is a major global cause of morbidity and mortality, and diabetes patients are at increased risk of coronary heart disease development. Advanced glycation of proteins occurs in the body due to raised concentrations of reducing sugars and reactive oxygen species, and is a causal factor behind complications of diabetes. Glycated proteins, through alteration of protein structure and function, and from ligation with their receptors, lead to widespread vascular damage. The alpha-oxoaldehyde, methylglyoxal (MG) is the most reactive glycation precursor, and is increased in the blood of diabetes patients. There is debate about the triggering events leading to atherosclerosis, but the inflammatory action of glycated proteins, including those with MG adducts, through their receptor, RAGE, is a major candidate for initiating plaque formation. In addition glycation may cause cross-links on proteins of the extracellular matrix, stiffening arteries and 'trapping' other macromolecules. MG is also likely to form adducts on many other proteins, enzymes, lipids, DNA or RNA, changing their structure, and may disrupt enzyme activity, hormone regulation and immune function. In the latter context, MG disrupts function of the potent antigen presenting cells, dendritic cells. This effect may be a double edged sword: Poor control of infections may contribute to persistent inflammation, whilst inhibition of immune activation by dendritic cells may inhibit plaque progression. This review aims to present these ideas as a novel slant on the role of the glycation process in atherosclerosis.
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Affiliation(s)
- C L Price
- Antigen Presentation Research Group, Imperial College London Faculty of Medicine, North West London Hospitals campus, Watford Road, Harrow, Middlesex, HA1 3UJ, UK
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Price CL, Williams DW, Waters MGJ, Coulthwaite L, Verran J, Taylor RL, Stickler D, Lewis MAO. Reduced adherence ofCandida to silane-treated silicone rubber. J Biomed Mater Res B Appl Biomater 2005; 74:481-7. [PMID: 15906392 DOI: 10.1002/jbm.b.30226] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Silicone rubber is widely used in the construction of medical devices that can provide an essential role in the treatment of human illness. However, subsequent microbial colonization of silicone rubber can result in clinical infection or device failure. The objective of this study was to determine the effectiveness of a novel silane-treated silicone rubber in inhibiting microbial adherence and material penetration. Test material was prepared by a combination of argon plasma discharge treatment and fluorinated silane coupling. Chemicophysical changes were then confirmed by X-ray photoelectron spectroscopy, contact-angle measurement, and atomic force microscopy. Two separate adherence assays and a material penetration assay assessed the performance of the new material against four strains of Candida species. Results showed a significant reduction (p < 0.01) of Candida albicans GDH 2346 adherence to silane-treated silicone compared with untreated controls. This reduction was still evident after the incorporation of saliva into the assay. Adherence inhibition also occurred with Candida tropicalis MMU and Candida krusei NCYC, although this was assay dependent. Reduced penetration of silane-treated silicone by Candida was evident when compared to untreated controls, plaster-processed silicone, and acrylic-processed silicone. To summarize, a novel silicone rubber material is described that inhibits both candidal adherence and material penetration. The clinical benefit and performance of this material remains to be determined.
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Affiliation(s)
- C L Price
- Department of Dental Heath and Biological Sciences, School of Dentistry, Cardiff University, UK
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Price CL. Beyond ADA. Tex Med 1996; 92:37-41. [PMID: 8826774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Price CL. Patients improve with pet therapy. Tex Med 1996; 92:12-3. [PMID: 8772370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Price CL. Concealed handgun law has safety, legal implications for physicians. Tex Med 1996; 92:18-9. [PMID: 8901061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Price CL, Pawlicki RE. The pain clinic: a multidisciplinary approach to long term pain. Weather Vane 1980; 49:2-3. [PMID: 6901447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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