884 research outputs found
Reconstruction methods for single-shot diffractive imaging of free nanostructures with ultrashort x-ray and XUV laser pulses
With x-ray and XUV single-shot diffractive imaging on free nanoparticles it is possible to investigate structure and shape of the particles. The scattering image of the nanoparticle only contains the intensity distribution but not the phase of the scattered light. Thus, numerical methods are required to infer information from experimental data. In the thesis, different reconstruction methods are implemented, advanced and applied to different scattering scenarios to characterize diffraction patterns for different laser parameters, reconstruct optical properties and 3d shapes of nanotargets.Mit Einzelschussmessungen an freien Nanoteilchen mit Hilfe von Röntgenstrahlung ist es möglich, die Teilchenstruktur zu untersuchen. Damit die Information aus Experimenten gewonnen werden kann, sind numerische Methoden notwendig, da das Streubild der Nanoteilchen nur die Inensitätsverteilung des gestreuten Lichtes, aber nicht die Phase bereitstellt. Es werden verschiedene Rekonstruktionsmethoden implementiert, weiterentwickelt und auf verschiedene Streuszenarien angewandt, um Streubilder für verschiedene Laserparameter zu charakterisieren, optische Eigenschaften und 3D-Formen zu rekonstruieren
The Sound of Feelings:Electrophysiological Responses Emotional Speech in Alexithymia
BACKGROUND: Alexithymia is a personality trait characterized by difficulties in the cognitive processing of emotions (cognitive dimension) and in the experience of emotions (affective dimension). Previous research focused mainly on visual emotional processing in the cognitive alexithymia dimension. We investigated the impact of both alexithymia dimensions on electrophysiological responses to emotional speech in 60 female subjects. METHODOLOGY: During unattended processing, subjects watched a movie while an emotional prosody oddball paradigm was presented in the background. During attended processing, subjects detected deviants in emotional prosody. The cognitive alexithymia dimension was associated with a left-hemisphere bias during early stages of unattended emotional speech processing, and with generally reduced amplitudes of the late P3 component during attended processing. In contrast, the affective dimension did not modulate unattended emotional prosody perception, but was associated with reduced P3 amplitudes during attended processing particularly to emotional prosody spoken in high intensity. CONCLUSIONS: Our results provide evidence for a dissociable impact of the two alexithymia dimensions on electrophysiological responses during the attended and unattended processing of emotional prosody. The observed electrophysiological modulations are indicative of a reduced sensitivity to the emotional qualities of speech, which may be a contributing factor to problems in interpersonal communication associated with alexithymia
Delayed wound repair in sepsis is associated with reduced local pro-inflammatory cytokine expression
Sepsis is one of the main causes for morbidity and mortality in hospitalized patients. Moreover, sepsis associated complications involving impaired wound healing are common. Septic patients often require surgical interventions that in-turn may lead to further complications caused by impaired wound healing. We established a mouse model to the study delayed wound healing during sepsis distant to the septic focus point. For this reason cecal ligation and puncture (CLP) was combined with the creation of a superficial wound on the mouse ear. Control animals received the same procedure without CPL. Epithelialization was measured every second day by direct microscopic visualization up to complete closure of the wound. As interplay of TNF-α, TGF-β, matrix metalloproteinases (MMP), and tissue inhibitors of metalloproteinases (TIMP) is important in wound healing in general, TNF-α, TGF-β, MMP7, and TIMP1 were assessed immunohistochemical in samples of wounded ears harvested on days 2, 6, 10 and 16 after wounding. After induction of sepsis, animals showed a significant delay in wound epithelialization from day 2 to 12 compared to control animals. Complete wound healing was attained after mean 12.2± standard deviation (SD) 3.0 days in septic animals compared to 8.7± SD 1.7 days in the control group. Septic animals showed a significant reduction in local pro-inflammatory cytokine level of TNF-α on day 2 and day 6 as well as a reduced expression of TGF-β on day 2 in wounds. A significant lower expression of MMP7 as well as TIMP1 was also observed on day 2 after wounding. The induction of sepsis impairs wound healing distant to the septic focus point. We could demonstrate that expression of important cytokines for wound repair is deregulated after induction of sepsis. Thus restoring normal cytokine response locally in wounds could be a good strategy to enhance wound repair in sepsis
Metabolic syndrome incidence in an aging workforce:Occupational differences and the role of health behaviors
This study investigates whether the incidence of metabolic syndrome (MetS), and its components, differs by occupational group among older workers (45–65 years) and whether health behaviors (smoking, leisure-time physical activity, diet quality, and alcohol consumption) can explain these differences. A sample of older workers (N = 34,834) from the North of the Netherlands was investigated. We analyzed data from two comprehensive measurement waves of the Lifelines Cohort Study and Biobank. MetS components were determined by physical measurements, blood markers, medication use, and self-reports. Occupational group and health behaviors were assessed by questionnaires. The association between occupational groups and MetS incidence was examined using logistic regression analysis. Health behaviors were subsequently added to the model to examine whether they can explain differences in MetS incidence between occupational groups. Low skilled white-collar (OR: 1.24; 95 % CI: 1.12, 1.37) and low skilled blue-collar (OR: 1.37; 95 % CI: 1.18, 1.59) workers had a significantly higher MetS incidence risk than high skilled white-collar workers. Similar occupational differences were observed on MetS component level. Combinations of unhealthy behaviors were more prevalent among blue-collar workers. MetS incidence in older workers differs between occupational groups and health behaviors explain a substantial part of these differences. Health promotion tailored to occupational groups may be beneficial specifically among older low skilled blue-collar workers. Research into other factors that contribute to occupational differences is needed as well as studies spanning the entire working life course
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Biological Risk Assessment of Three Dental Composite Materials following Gas Plasma Exposure
Gas plasma is an approved technology that generates a plethora of reactive oxygen species, which are actively applied for chronic wound healing. Its particular antimicrobial action has spurred interest in other medical fields, such as periodontitis in dentistry. Recent work has indicated the possibility of performing gas plasma-mediated biofilm removal on teeth. Teeth frequently contain restoration materials for filling cavities, e.g., resin-based composites. However, it is unknown if such materials are altered upon gas plasma exposure. To this end, we generated a new in-house workflow for three commonly used resin-based composites following gas plasma treatment and incubated the material with human HaCaT keratinocytes in vitro. Cytotoxicity was investigated by metabolic activity analysis, flow cytometry, and quantitative high-content fluorescence imaging. The inflammatory consequences were assessed using quantitative analysis of 13 different chemokines and cytokines in the culture supernatants. Hydrogen peroxide served as the control condition. A modest but significant cytotoxic effect was observed in the metabolic activity and viability after plasma treatment for all three composites. This was only partially treatment time-dependent and the composites alone affected the cells to some extent, as evident by differential secretion profiles of VEGF, for example. Gas plasma composite modification markedly elevated the secretion of IL6, IL8, IL18, and CCL2, with the latter showing the highest correlation with treatment time (Pearson’s r > 0.95). Cell culture media incubated with gas plasma-treated composite chips and added to cells thereafter could not replicate the effects, pointing to the potential that surface modifications elicited the findings. In conclusion, our data suggest that gas plasma treatment modifies composite material surfaces to a certain extent, leading to measurable but overall modest biological effects
Metabolic syndrome and poor self-rated health as risk factors for premature employment exit:a longitudinal study among 55 016 middle-aged and older workers from the Lifelines Cohort Study and Biobank
BACKGROUND: Poor self-rated health (SRH) is a well-established risk factor for premature employment exit through unemployment, work disability, and early retirement. However, it is unclear whether the premature employment exit risk associated with underlying cardio-metabolic health conditions is fully captured by poor SRH. This study examines the metabolic syndrome (MetS), an early-stage risk factor for cardiovascular disease and type two diabetes mellitus, as a risk factor for premature employment exit while controlling for poor SRH.METHODS: We analyzed data from N = 55 016 Dutch workers (40-64 years) from five waves of the Lifelines Cohort Study and Biobank. MetS components were based on physical measures, blood markers, and medication use. SRH and employment states were self-reported. The associations between MetS, SRH, and premature employment exit types were analyzed using competing risk regression analysis.RESULTS: During 4.3 years of follow-up, MetS remained an independent risk factor for unemployment [adjusted subdistribution hazard ratio (SHR): 1.14, 95% CI: 1.03, 1.25] and work disability (adjusted SHR: 1.33, 95% CI: 1.11, 1.58) when adjusted for poor SRH, common chronic diseases related to labor market participation (i.e., cancer, musculoskeletal-, pulmonary-, and psychiatric diseases), and sociodemographic factors. MetS was not associated with early retirement.CONCLUSIONS: Poor SRH did not fully capture the risk for unemployment and work disability associated with MetS. More awareness about MetS as a 'hidden' cardio-metabolic risk factor for premature employment exit is needed among workers, employers, and occupational health professionals. Regular health check-ups including MetS assessment and MetS prevention might help to prolong healthy working lives.</p
The Relation of Surgical Procedures and Diagnosis Groups to Unplanned Readmission in Spinal Neurosurgery: A Retrospective Single Center Study
Background: Unplanned readmission has gained increasing interest as a quality marker for inpatient care, as it is associated with patient mortality and higher economic costs. Spinal neurosurgery is characterized by a lack of epidemiologic readmission data. The aim of this study was to identify causes and predictors for unplanned readmissions related to index diagnoses and surgical procedures. Methods: In this study, from 2015 to 2017, spinal neurosurgical procedures were recorded for surgical and non-surgical treated patients. The main reasons for an unplanned readmission within 30 days following discharge were identified. Multivariate logarithmic regression revealed predictors of unplanned readmission. Results: A total of 1172 patient records were examined, of which 4.27% disclosed unplanned readmissions. Among the surgical patients, the readmission rate was 4.06%, mainly attributable to surgical site infections, while it was 5.06% for the non-surgical patients, attributable to uncontrolled pain. A night-time surgery presented as the independent predictive factor. Conclusion: In the heterogeneous group of spinal neurosurgical patients, stratification into diagnostic groups is necessary for statistical analysis. Degenerative lumbar spinal stenosis and spinal abscesses are mainly affected by unplanned readmission. The surgical procedure dorsal root ganglion stimulation is an independent predictor of unplanned re-hospitalizations, as is the timing of surgery
Inclusivity insights:two urban development projects in Johannesburg
Johannesburg, which is South Africa’s largest city and economic center, is still influenced by patterns of inequality of the past. Although spatial transformation has been rapid since 1994, spatial divisions along class lines are still prevalent long after the apartheid era. This is despite the fact that societal values such as inclusivity, spatial justice and equal access to resources have become the core goals of Johannesburg’s spatial and urban development. This is particularly true when addressing housing, public open spaces, transport and social infrastructure embedded in a suitable land-use mix. However, despite the adoption of numerous policies by government, this research indicates that even recent urban development projects such as Fleurhof and Waterfall are falling short in delivering those objectives. Based on a case study analysis, we show that significant disfunctionalities become evident when evaluating these two projects, despite their meeting relevant indicators of spatial inclusion on paper. Tensions are identified between theoretical approaches and the implementation of societally relevant policy goals. These include inclusivity and spatial justice by mostly privatized provision of housing and services, and deficiencies in public maintenance of infrastructure. The research reveals, that ‘ticking-the-boxes’ behavior on policy and project level does not produce equitable, inclusive neighborhoods and urban spatial patterns, but rather reproduces spatial inequalities of the past. If these policies are to result in real spatial change and improvement in the lives of Johannesburg residents, a more proactive approach by the public sector at different levels will be necessary
Suicide risk management in research on internet-based interventions for depression:A synthesis of the current state and recommendations for future research
BACKGROUND: The number of studies examining internet-based interventions (IBIs) for depression is increasing. Although many individuals with depression experience suicidal ideation, there is only insufficient information available on how to manage and support individuals at risk of suicide in IBI trials. Here, we examined the current practice regarding the management of individuals experiencing suicidal thoughts or behaviors in studies of IBIs for depression. METHODS: Information pertaining to the management of suicidality was extracted from 24 studies. Additionally, researchers in the field completed a questionnaire (n = 13) before being interviewed (n = 11) about their procedures and considerations regarding the management of suicidality. RESULTS: In most trials (N = 17; 71%), individuals at risk of suicide were excluded based on varying criteria. N = 7 studies used structured interviews and N = 5 studies used single items of self-report questionnaires for assessing suicidality. The nature and degree of support provided to individuals at risk of suicide varied and only one intervention comprised suicide-specific content. LIMITATIONS: Most experts referred to research on interventions with some level of human support (e.g. written feedback) which might limit the representativeness of the results of the interviews for unguided interventions. CONCLUSIONS: Suicidality is often treated more as an exclusion criterion rather than a treatable condition in research on IBIs for depression. This paper provides an overview of the current practice and gives recommendations for the design of future trials
No Significant Bone Resorption after Open Treatment of Mandibular Condylar Head Fractures in the Medium-Term
Open treatment of condylar head fractures (CHF) is considered controversial. In this retrospective cohort study our primary objective was therefore to assess bone resorption and remodeling as well as patients function after open treatment of CHF in a medium-term follow-up (15.1 ± 2.2 months). We included 18 patients with 25 CHF who underwent open reduction and internal fixation, between 2016 and 2021, in our analysis. The clinical data and cone-beam computed tomography (CBCT) datasets were analyzed. The condylar processes were segmented in the postoperative (T1) and follow-up (T2) CBCT scans. Volumetric and linear bone changes were the primary outcome variables, measured by using a sophisticated 3D-algorithm. The mean condylar head volume decreased non-significantly from 3022.01 ± 825.77 mm3 (T1) to 2878.8 ± 735.60 mm3 (T2; p = 0.52). Morphological alterations indicated remodeling and resorption. The pre-operative maximal interincisal opening (MIO) was 19.75 ± 3.07 mm and significantly improved to 40.47 ± 1.7 mm during follow-up (p = 0.0005). Low rates of postoperative complications were observed. Open reduction of CHF leads to good clinical outcomes and low rates of medium-term complications. This study underlines the feasibility and importance of open treatment of CHF and may help to spread its acceptance as the preferred treatment option
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