Quantitative CT analysis in patients with pulmonary emphysema: is lung function influenced by concomitant unspecific pulmonary fibrosis?

Purpose: Quantitative analysis of CT scans has proven to be a reproducible technique, which might help to understand the pathophysiology of chronic obstructive pulmonary disease (COPD) and combined pulmonary fibrosis and emphysema. The aim of this retrospective study was to find out if the lung function of patients with COPD with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages III or IV and pulmonary emphysema is measurably influenced by high attenuation areas as a correlate of concomitant unspecific fibrotic changes of lung parenchyma. Patients and methods: Eighty-eight patients with COPD GOLD stage III or IV underwent CT and pulmonary function tests. Quantitative CT analysis was performed to determine low attenuation volume (LAV) and high attenuation volume (HAV), which are considered to be equivalents of fibrotic (HAV) and emphysematous (LAV) changes of lung parenchyma. Both parameters were determined for the whole lung, as well as peripheral and central lung areas only. Multivariate regression analysis was used to correlate HAV with different parameters of lung function. Results: Unlike LAV, HAV did not show significant correlation with parameters of lung function. Even in patients with a relatively high HAVof more than 10%, in contrast to HAV (p=0.786) only LAV showed a significantly negative correlation with forced expiratory volume in 1 second (r=−0.309, R2=0.096, p=0.003). A severe decrease of DLCO% was associated with both larger HAV (p=0.045) and larger LAV (p=0.001). Residual volume and FVC were not influenced by LAV or HAV. Conclusion: In patients with COPD GOLD stage III-IV, emphysematous changes of lung parenchyma seem to have such a strong influence on lung function, which is a possible effect of concomitant unspecific fibrosis is overwhelmed

Insights into the Bead Fusion Mechanism of Expanded Polybutylene Terephthalate (E-PBT)

Expandable polystyrene (EPS) and expanded polypropylene (EPP) dominate the bead foam market. As the low thermal performance of EPS and EPP limits application at elevated temperatures novel solutions such as expanded polybutylene terephthalate (E-PBT) are gaining importance. To produce parts, individual beads are typically molded by hot steam. While molding of EPP is well-understood and related to two distinct melting temperatures, the mechanisms of E-PBT are different. E-PBT shows only one melting peak and can surprisingly only be molded when adding chain extender (CE). This publication therefore aims to understand the impact of thermal properties of E-PBT on its molding behavior. Detailed differential scanning calorimetry was performed on neat and chain extended E-PBT. The crystallinity of the outer layer and center of the bead was similar. Thus, a former hypothesis that a completely amorphous bead layer enables molding, was discarded. However, the incorporation of CE remarkably reduces the crystallization and re-crystallization rate. As a consequence, the time available for interdiffusion of chains across neighboring beads increases and facilitates crystallization across the bead interface. For E-PBT bead foams, it is concluded that sufficient time for polymer interdiffusion during molding is crucial and requires adjusted crystallization kinetics

Preparation and Catalytic Activity of Boron-Substituted Zirconocenes

Borylated zirconocenes of the type (L2B–C5H4)2ZrCl2 and (L2B–C5H4)(C5H5)ZrCl2 are readily available in two steps. In the polymerization of ethylene and propylene in the presence of AlEt3 or methylalumoxan (MAO), these zirconocenes are more active than the unsubstituted reagent Cp2ZrCl2

Structural Barriers In The Context Of Opiate Substitution Treatment In Germany - A Survey Among Physicians In Primary Care

Background Opiate substitution treatment (OST) is the most widely used treatment for opioid dependence in Germany with substantial long-term benefits for the patient and for society. Due to lessened restrictive admission criteria, the number of registered OST patients in Germany has increased continuously in the recent years, whereas the number of physicians providing OST has remained constant. Previous data already indicated a deteriorating situation in the availability or quality of OST delivered and that structural barriers impede physicians in actively providing OST. The present survey among a sample of primary care physicians in Germany aimed to identify and assess potential structural barriers for the provision of health care in the context of OST. Methods An anonymous written questionnaire was sent out to a sample of 2,332 physicians across Germany providing OST. Physicians contacted were identified through databases of the Federal State Chambers of Physicians and/or of the Federal Associations of Statutory Health Insurance Physicians. Data obtained were analysed descriptively. Results The response rate was 25,5% and the majority of 596 physicians sampled viewed substantial problems in terms of the regulatory framework of OST care in the German context. Furthermore, financial remuneration, insufficient qualification, as well as inadequate interdisciplinary cooperation in the treatment of comorbidities of opiate substituted patients were regarded as problematic. The number of physicians providing OST in Germany is expected to substantially decrease in the near future. Conclusion Despite less restrictive admission criteria for OST in Germany, the legal regulation framework for OST is still a limiting factor through raising concerns on the provider and consumer side to be unable to adhere to the strict rules. To avoid future shortages in the provision of OST care on the system level in Germany, revisions to the legal framework seem to be necessary. In regards to adequate care for drug use-related infectious diseases and psychiatric comorbidities commonly found in opiate substituted patients, efforts are required to improve professional qualifications of physicians providing OST as well as respective interdisciplinary collaboration

Psychiatric disorders and health service utilization in unemployed youth

Aim: Youth unemployment is associated with increased levels of anxiety, depression, alcohol abuse, reduced self-esteem and satisfaction with life. Up to date data based on standardized psychiatric diagnostic assessments in adolescent or young adult unemployment is very scarce. To our knowledge, this study has, for the first time, assessed both Axis-I (non-personality) and Axis-II (personality) psychiatric disorders and related constructs in a preselected sample of unemployed individuals. Subjects and methods: Subjects were aged 16–24 and lived in the large urban region of Essen, Germany. They were referred by case managers of the vocational services centre to the on-site psychiatric out-patient unit. SCID-I and II were administered to assess DSM-IV diagnoses. Symptom Checklist 90 R, Beck Depression Inventory and Client Sociodemographic Service Receipt Inventory were used to measure severity of psychopathology and health service utilization. Results: In all, 98% of the unemployed young adults suffered from mental disorders. Mood and anxiety disorders were the most common Axis-I disorders (47.9 and 33.4%). Altogether, 58.2% of probands met diagnostic criteria for a personality disorder; a borderline personality disorder accounted for one half of these disorders. Despite a 49% rate of Axis-I and II comorbidity and severe psychopathology, the majority of subjects were untreated and mental health service utilization in general was low. The diagnosis of a personality disorder was related to a 2.7-fold risk of dropping out of job reintegration programmes. Conclusion: Unemployed young adults referred for a psychiatric assessment have a high rate of both Axis-I and II disorders, which need to be considered upon planning individual-based vocational rehabilitation programs

Criteria for the successful completion of medical dissertations – A multicenter study

Objective: In order to acquire the academic title “doctor” in Germany, it is essential to complete a dissertation. A high number of publications at German universities are based on medical dissertations. The reasons why some dissertations are successfully accomplished and why some are not completed – despite far-reaching consequences – have been barely investigated to date

Benefits and pitfalls of scientific research during undergraduate medical education

Objective: The integration of scientific research into medical education is a widely discussed topic. Most research training programs are offered on a voluntary basis. In Germany, it is mandatory to complete a doctoral thesis to obtain the academic title “doctor”. The reasons why students start a dissertation project and the influence of this project on their undergraduate studies and later career choices are not well known

Lectures based on cardinal symptoms in undergraduate medicine - effects of evaluation-based interventions on teaching large groups

Despite critical voices lectures are still an important teaching format in current medical curricula. With the curricular reform at Hamburg Medical Faculty in the year 2004, all subject specific lectures were replaced by cardinal symptom oriented lectures (LSV) in the new clinical curriculum. LSVs are taught throughout all six thematic blocks in years three to five. Since regular student evaluations after each thematic block seemed to demand improvement of the LSVs, this study was carried out using evaluations of individual LSVs by the participating students and by trained auditors (final year students and academic staff). Based on these evaluations feedback containing the individual evaluation data was given in written form to the lecturers combined with information material on planning an LSV using modern didactic techniques. In a second evaluation period, the effects of this intervention were studied. Only small improvements in the LSVs’ quality were noted regarding the level of marks achieved. When individual items were evaluated, especially the didactic quality, significant improvements were noticeable. Overall, on the basis of individual items students ranked the quality of the LSVs significantly higher than trained auditors during the first evaluation period. This effect was no longer seen after the second evaluation period. The inter rater reliability among the auditors was very good. This study shows that regular quality assurance is needed on the structural levels and for staff to accompany the process of embedding teaching formats into curricular concepts. Further investigation is needed to determine the adequate frequency of evaluation and the format of feedback to guarantee sustainable effects of the didactic quality of lectures