| 1. |
- Buchholz, Angela, et al.
(författare)
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Deconvolution of FIGAERO-CIMS thermal desorption profiles using positive matrix factorisation to identify chemical and physical processes during particle evaporation
- 2020
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 20:13, s. 7693-7716
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Tidskriftsartikel (refereegranskat)abstract
- The measurements of aerosol particles with a filter inlet for gases and aerosols (FIGAERO) together with a chemical ionisation mass spectrometer (CIMS) yield the overall chemical composition of the particle phase. In addition, the thermal desorption profiles obtained for each detected ion composition contain information about the volatility of the detected compounds, which is an important property for understanding many physical properties like gas-particle partitioning. We coupled this thermal desorption method with isothermal evaporation prior to the sample collection to investigate the chemical composition changes during isothermal particle evaporation and particulate-water-driven chemical reactions in alpha-pinene secondary organic aerosol (SOA) of three different oxidative states. The thermal desorption profiles of all detected elemental compositions were then analysed with positive matrix factorisation (PMF) to identify the drivers of the chemical composition changes observed during isothermal evaporation. The keys to this analysis were to use the error matrix as a tool to weight the parts of the data carrying most information (i.e. the peak area of each thermogram) and to run PMF on a combined data set of multiple thermograms from different experiments to enable a direct comparison of the individual factors between separate measurements. The PMF was able to identify instrument background factors and separate them from the part of the data containing particle desorption information. Additionally, PMF allowed us to separate the direct desorption of compounds detected at a specific elemental composition from other signals with the same composition that stem from the thermal decomposition of thermally instable compounds with lower volatility. For each SOA type, 7-9 factors were needed to explain the observed thermogram behaviour. The contribution of the factors depended on the prior isothermal evaporation. Decreased contributions from the factors with the lowest desorption temperatures were observed with increasing isothermal evaporation time. Thus, the factors identified by PMF could be interpreted as volatility classes. The composition changes in the particles due to isothermal evaporation could be attributed to the removal of volatile factors with very little change in the desorption profiles of the individual factors (i.e. in the respective temperatures of peak desorption, T-max). When aqueous-phase reactions took place, PMF was able to identify a new factor that directly identified the ions affected by the chemical processes. We conducted a PMF analysis of the FIGAERO-CIMS thermal desorption data for the first time using laboratory-generated SOA particles. But this method can be applied to, for example, ambient FIGAERO-CIMS measurements as well. There, the PMF analysis of the thermal desorption data identifies organic aerosol (OA) sources (such as biomass burning or oxidation of different precursors) and types, e.g. hydrocarbon-like (HOA) or oxygenated organic aerosol (OOA). This information could also be obtained with the traditional approach, namely the PMF analysis of the mass spectra data integrated for each thermogram. But only our method can also obtain the volatility information for each OA source and type. Additionally, we can identify the contribution of thermal decomposition to the overall signal.
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| 2. |
- Buchholz, Angela, et al.
(författare)
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Insights into the O : C-dependent mechanisms controlling the evaporation of alpha-pinene secondary organic aerosol particles
- 2019
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 19:6, s. 4061-4073
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Tidskriftsartikel (refereegranskat)abstract
- The volatility of oxidation products of volatile organic compounds (VOCs) in the atmosphere is a key factor to determine if they partition into the particle phase contributing to secondary organic aerosol (SOA) mass. Thus, linking volatility and measured particle composition will provide insights into SOA formation and its fate in the atmosphere. We produced alpha-pinene SOA with three different oxidation levels (characterized by average oxygen-to-carbon ratio; (O:C) over bar = 0.53, 0.69, and 0.96) in an oxidation flow reactor. We investigated the particle volatility by isothermal evaporation in clean air as a function of relative humidity (RH < 2 %, 40 %, and 80 %) and used a filter-based thermal desorption method to gain volatility and chemical composition information. We observed reduced particle evaporation for particles with increasing <(O:C )over bar> ratio, indicating that particles become more resilient to evaporation with oxidative aging. Particle evaporation was increased in the presence of water vapour and presumably particulate water; at the same time the resistance of the residual particles to thermal desorption was increased as well. For SOA with (O:C ) over bar = 0.96, the unexpectedly large increase in mean thermal desorption temperature and changes in the thermogram shapes under wet conditions (80 % RH) were an indication of aqueous phase chemistry. For the lower (O:C ) over bar cases, some water-induced composition changes were observed. However, the enhanced evaporation under wet conditions could be explained by the reduction in particle viscosity from the semi-solid to liquid-like range, and the observed higher desorption temperature of the residual particles is a direct consequence of the increased removal of high-volatility and the continued presence of low-volatility compounds.
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| 3. |
- Buchholz, Angela, et al.
(författare)
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Patient-Centered Placement Matching of Alcohol-Dependent Patients Based on a Standardized Intake Assessment : Primary Outcomes of an Exploratory Randomized Controlled Trial
- 2020
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Ingår i: European Addiction Research. - : S. Karger AG. - 1022-6877 .- 1421-9891. ; 26:3, s. 109-121
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Tidskriftsartikel (refereegranskat)abstract
- Background: Placement matching guidelines are promising means to optimize patient-centered care and to match patients' treatment needs. Despite considerable research regarding placement matching approaches to optimize alcohol abuse treatment, findings are inconclusive. Objectives: To investigate whether the use of patient-centered placement matching (PCPM) guidelines is more effective in reducing heavy drinking and costs 6 months after discharge from an inpatient alcohol withdrawal treatment compared to usual referral to aftercare. Secondary aims were to investigate whether age, gender, trial site or level of care (LOC) are moderators of efficacy and whether patients who were actually referred to the recommended LOC had better treatment outcomes compared to patients who were treated under- or overmatched. Methods: Design. Exploratory randomized controlled trial with measurements during withdrawal treatment and 6 months after initial assessment. Setting. Four German psychiatric clinics offering a 7-21 day inpatient qualified withdrawal program for patients suffering from alcohol dependence. Participants. From 1,927 patients who had a primary diagnosis of alcohol dependence and did not have organized aftercare when entering withdrawal treatment, 299 were invited to participate. Of those, 250 were randomized to the intervention group (IG, n = 123) or the control group (CG, n = 127). Intervention. The PCPM were applied to patients of the IG by feeding back a recommendation to a LOC for aftercare that was calculated from the Measurements in the Addictions for Triage and Evaluation (MATE) and discussed with the staff of the treatment unit. Patients of the CG received a general feedback regarding their MATE interview on request. Measurements. The MATE, the Client Socio-Demographic and Service Receipt Inventory--European Version and the MATE-Outcomes were administered. Data were analyzed using generalized linear models. Results: In the intention-to-treat analysis, there were no significant differences between IG and CG regarding days of heavy drinking (incident risk ratio [IRR] 1.09; p = 0.640), direct (IRR 1.06; p = 0.779), indirect (IRR 0.77; p = 0.392) and total costs (IRR 0.89; p = 0.496). Furthermore, none of the investigated moderator variables affected statistically significant drinking or cost-related primary outcomes. Regardless of group allocation, patients who received matched aftercare reported significantly fewer days of heavy drinking than undermatched patients (IRR 2.09; p = 0.004). For patients who were overmatched, direct costs were significantly higher (IRR 1.79; p = 0.024), but with no additional effects on alcohol consumption compared to matched patients. Conclusions: While the use of PCPM failed to affect the actual referral to aftercare, our findings suggest that treating patients on the recommended LOC may have the potential to reduce days of heavy drinking compared to undertreatment and costs compared to overtreatment.
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| 4. |
- Buchholz, Angela, et al.
(författare)
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Patient-centered placement matching of alcohol-dependent patients based on a standardized intake assessment : process evaluation within an exploratory randomized controlled trial
- 2022
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Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the implementation of placement matching guidelines, feasibility has been concerned in previous research. Objectives of this process evaluation were to investigate whether the patient-centered matching guidelines (PCPM) are consistently applied in referral decision-making from an inpatient qualified withdrawal program to a level of care in aftercare, which factors affect whether patients actually receive matched aftercare according to PCPM, and whether its use is feasible and accepted by clinic staff.Methods: The study was conducted as process evaluation within an exploratory randomized controlled trial in four German psychiatric clinics offering a 7-to-21 day qualified withdrawal program for patients suffering from alcohol dependence, and with measurements taken during detoxification treatment and six months after the initial assessment. PCPM were used with patients in the intervention group by feeding back to them a recommendation for a level of care in aftercare that had been calculated from Measurements in the Addictions for Triage and Evaluation (MATE) and discussed with the staff on the treatment unit. As measurements, The MATE, the Client Socio-Demographic and Service Receipt Inventory—European Version, a documentation form, the Control Preference Scale, and the Motivation for Treatment Scale were administered. A workshop for the staff at the participating trial sites was conducted after data collection was finished.Results: Among 250 patients participating in the study, 165 were interviewed at follow-up, and 125 had received aftercare. Although consistency in the application of PCPM was moderate to substantial within the qualified withdrawal program (Cohen’s kappa ≥ .41), it was fair from discharge to follow-up. In multifactorial multinomial regression, the number of foregoing substance abuse treatments predicted whether patients received more likely undermatched (Odds Ratio=1.27; p=.018) or overmatched (Odds Ratio=0.78; p=.054) treatment. While the implementation process during the study was evaluated critically by the staff, they stated a potential of quality assurance, more transparency and patient-centeredness in the use of PCPM.Conclusions: While the use of PCPM has the potential to enhance the quality of referral decision making within treatment, it may not be sufficient to determine referral decisions for aftercare.Trial Registration: German Clinical Trials Register DRKS00005035. Registered 03/06/2013.
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| 5. |
- Buchholz, Angela, et al.
(författare)
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Placement matching of alcohol-dependent patients based on a standardized intake assessment : rationale and design of a randomized controlled trial
- 2014
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Ingår i: BMC Psychiatry. - : Springer Science and Business Media LLC. - 1471-244X. ; 14, s. 286-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Despite considerable research on substance-abuse placement matching, evidence is still inconclusive. The aims of this exploratory trial are to evaluate (a) the effects of following matching guidelines on health-care costs and heavy drinking, and (b) factors affecting the implementation of matching guidelines in the treatment of alcohol-dependent patients. Methods: A total of 286 alcohol-dependent patients entering one of four participating detoxification units and having no arrangements for further treatment will be recruited. During the first week of treatment, all patients will be administered Measurements in the Addictions for Triage and Evaluation (MATE), European Quality of Life-Five Dimensions health status questionnaire (EQ-5D), and the Client Socio-Demographic and Service Receipt Inventory-European Version (CSSRI-EU). Patients who are randomly allocated to the intervention group will receive feedback regarding their assessment results, including clear recommendations for subsequent treatment. Patients of the control group will receive treatment as usual and, if requested, global feedback regarding their assessment results, but no recommendations for subsequent treatment. At discharge, treatment outcome and referral decisions will be recorded. Six months after discharge, patients will be administered MATE-Outcome, EQ-5D, and CSSRI-EU during a telephone interview. Discussion: This trial will provide evidence on the effects and costs of using placement-matching guidelines based on a standardized assessment with structured feedback in the treatment of alcohol-dependent patients. A process evaluation will be conducted to facilitate better understanding of the relationship between the use of guidelines, outcomes, and potential mediating variables.
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| 6. |
- Dalirian, Maryam, 1978-, et al.
(författare)
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Cloud droplet activation of black carbon particles coated with organic compounds of varying solubility
- 2018
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Ingår i: Atmospheric Chemistry and Physics Discussions. - : Copernicus GmbH. - 1680-7367 .- 1680-7375. ; 18:16, s. 12477-12489
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric black carbon (BC) particles are a concern due to their impact on air quality and climate. Their net climate effect 15 is, however, still uncertain. This uncertainty is partly related to the contribution of coated BC-particles to the global CCN budgets. In this study, laboratory measurements were performed to investigate cloud condensation nuclei (CCN) activity of BC (Regal black) particles, in pure state or coated through evaporating and subsequent condensation of glutaric acid, levoglucosan (both water-soluble organics) or oleic acid (an organic compound with low solubility). A combination of Soot Particle Aerosol Mass Spectrometer (SP-AMS) measurements and size distribution measurements with Scanning Mobility 20 Particle Sizer (SMPS) showed that the studied BC particles were nearly spherical agglomerates with a fractal dimension of 2.79 and that they were coated evenly by the organic species. The CCN activity of BC particles increased after coating with all the studied compounds and was governed by the fraction of organic material. The CCN activation of the BC particles coated by glutaric acid and levoglucosan were in good agreement with the theoretical calculations using shell-and-core model, which is based on a combination of the CCN activities of the pure compounds. The oleic acid coating enhanced the CCN 25 activity of the BC particles, even though the pure oleic acid particles were CCN inactive. The surprising effect of oleic acid might be related to the arrangement of the oleic acid molecules on the surface of the BC cores or other surface phenomena facilitating water condensation onto the coated particles. Our results show potential in accurately predicting the CCN activity of atmospheric BC coated with organic species by present theories, given that the identities and amount of the coating species are known. Furthermore, our results suggest that even relatively thin soluble coatings (around 2 nm for the compounds studied here) are enough to make the insoluble BC particles CCN active at typical atmospheric supersaturations and thus be efficiently taken up by cloud droplets. This highlights the need of an accurate description of the composition of atmospheric particles containing BC to unravel their net impact on climate.
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| 7. |
- Dams, Judith, et al.
(författare)
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Excess costs of alcohol-dependent patients in German psychiatric care compared with matched non-alcohol-dependent individuals from the general population : a secondary analysis of two datasets
- 2018
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Ingår i: BMJ Open. - : BMJ. - 2044-6055. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Heavy alcohol use can cause somatic and mental diseases, affects patients' social life and is associated with social isolation, unemployment and reduced quality of life. Therefore, societal costs of alcohol dependence are expected to be high. The aim of this study was to estimate excess costs of patients with alcohol dependence diagnosed using the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition criteria compared with individuals without alcohol dependence in Germany. Design In a secondary analysis, baseline data of patients with alcohol dependence enrolled in a randomised controlled trial (German Clinical Trials Register DRS00005035) were compared with data collected via a telephone survey from individuals without alcohol dependence and that had been matched by entropy balancing. Health service use was evaluated retrospectively for a 6-month period. Settings Four German psychiatric university clinics (patients with alcohol dependence) and the German general adult population (individuals without alcohol dependence). Participants n=236adult patients with alcohol dependence and n=4687adult individuals without alcohol dependence. Primary and secondary outcome measures The excess costs of health service use, absenteeism and unemployment of patients with alcohol dependence were calculated and compared with individuals without alcohol dependence. In subgroup analyses, the associations between excess cost and gender, comorbidities and the duration of disease were investigated. Results Total 6-month excess costs of Euro11839 (95% CI Euro11 529 to Euro12 147) were caused by direct excess costs of Euro4349 (95% CI Euro4129 to Euro4566) and indirect costs of Euro7490 (95% CI Euro5124 to Euro9856). In particular, costs of inpatient treatment, formal long-term care, absenteeism and unemployment were high. Conclusions Alcohol dependence causes substantial direct and indirect excess costs. Cost-effective interventions to prevent and treat alcohol dependence are urgently needed. Trial registration number DRKS00005035.
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| 8. |
- Friedrichs, Anke, et al.
(författare)
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Role preferences of patients with alcohol use disorders
- 2018
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Ingår i: Addictive Behaviours. - : Elsevier BV. - 0306-4603 .- 1873-6327. ; 84, s. 248-254
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Tidskriftsartikel (refereegranskat)abstract
- AimsShared decision making (SDM) is increasingly demanded in medical decision making. SDM acknowledges patients' role preferences in decision making processes. There has been limited research on SDM and role preferences in substance use disorders; results are promising. Aim of this study was to investigate role preferences of patients with alcohol use disorders (AUD), and to identify predictors of these preferences.MethodCross-sectional data collected from June 2013 to May 2014 in four detoxification wards in Germany during a randomised controlled trial (RCT, Registration Code O1GY1114) was analysed. Of the 250 patients with AUD who were included in the RCT, data from 242 patients [65% male; mean age = 45.2 years (sd = 10.3)] were analysed. Participants' role preferences were assessed with the Control Preference Scale. Potential correlates were drawn from instruments used in the RCT; multinomial logistic regression was used.Results90% (n = 217) of the AUD patients preferred an active or shared role in decision-making, 10% (n = 25) preferred a passive role. Patients' desire for help was associated with their role preference (OR = 3.087, p = .05). The model's goodness of fit was Nagelkerke's R-2 = 0.153 [chi(2) (24) = 25.206, p = .395].ConclusionsPatients' preference for an active role in decision-making underscores the importance of involving patients in their treatment planning. Patients' desire for help seems to be an important determinant of paternalistic decision making. However, further research is needed to determine whether patients' role preferences are related to their behavior during their treatment referral and recovery.
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| 9. |
- Frischknecht, Ulrich, et al.
(författare)
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Screening auf problematischen Alkoholkonsum – Erhebung zur Umsetzung der S3-Leitlinienempfehlungen in der transdisziplinären Versorgung einer Modellregion : [Screening for Problematic Alcohol Consumption – A Survey on Guideline Implementation in Transdisciplinary Health Care of a Model Region]
- 2022
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Ingår i: Das Gesundheitswesen. - : Georg Thieme Verlag KG. - 0941-3790 .- 1439-4421. ; 84:01, s. 43-51
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Tidskriftsartikel (refereegranskat)abstract
- Aim Recording the frequency of screenings for problematic alcohol consumption by professionals involved in the health care of respective patients. The German S3-guideline screening, diagnosis and treatment of alcohol-related disorders recommends the use of questionnaire-based screenings for all patients in all settings.Methods Cross-sectional survey on screening frequency among general practitioners, gynecologists, psychiatrists, child- and adolescent therapists, psychotherapists, social workers and midwives. Logistic regression was used to explore how healthcare professionals' attributes were associated with the implementation of screenings.Results With response rates of about 20%, health care professionals reported using screening instruments for an average of 6.9% of all patients during the previous four weeks. Most of the time, custom-made questions were used instead of the recommended instruments (AUDIT, AUDIT-C). Higher screening rates were reported for patients with newly diagnosed hypertension (21.2%), alcohol-related disorders (43.3%) and mental disorders (39.3%). Knowledge of the guideline was associated with implementation of screenings (OR=4.67; 95% KI 1.94-11.25, p<0.001).Conclusions Comprehensive screening for problematic alcohol use with questionnaire-based instruments in accordance with guidelines is far from being routinely implemented in the studied health care settings. Measures to increase the knowledge of the guidelines are necessary in order to increase the frequency of alcohol screening in health care.
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| 10. |
- Gramlich, Yvette, 1993-, et al.
(författare)
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Impact of Biomass Burning on Arctic Aerosol Composition
- 2024
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Ingår i: ACS Earth and Space Chemistry. - 2472-3452.
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Tidskriftsartikel (refereegranskat)abstract
- Emissions from biomass burning (BB) occurring at midlatitudes can reach the Arctic, where they influence the remote aerosol population. By using measurements of levoglucosan and black carbon, we identify seven BB events reaching Svalbard in 2020. We find that most of the BB events are significantly different to the rest of the year (nonevents) for most of the chemical and physical properties. Aerosol mass and number concentrations are enhanced by up to 1 order of magnitude during the BB events. During BB events, the submicrometer aerosol bulk composition changes from an organic- and sulfate-dominated regime to a clearly organic-dominated regime. This results in a significantly lower hygroscopicity parameter κ for BB aerosol (0.4 ± 0.2) compared to nonevents (0.5 ± 0.2), calculated from the nonrefractory aerosol composition. The organic fraction in the BB aerosol showed no significant difference for the O:C ratios (0.9 ± 0.3) compared to the year (0.9 ± 0.6). Accumulation mode particles were present during all BB events, while in the summer an additional Aitken mode was observed, indicating a mixture of the advected air mass with locally produced particles. BB tracers (vanillic, homovanillic, and hydroxybenzoic acid, nitrophenol, methylnitrophenol, and nitrocatechol) were significantly higher when air mass back trajectories passed over active fire regions in Eastern Europe, indicating agricultural and wildfires as sources. Our results suggest that the impact of BB on the Arctic aerosol depends on the season in which they occur, and agricultural and wildfires from Eastern Europe have the potential to disturb the background conditions the most.
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