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The inhalation of particulate matter (PM) in second-hand smoke (SHS) is hazardous to health of smokers and non-smokers. Tobacco strength (amount of tar, nicotine, and carbon monoxide) and different additives might have an effect on the amount of PM. This study aimed to investigate the influence of tobacco strength or additives on PM. Four cigarette types of the brand Marlboro with different strengths and with or without additives were analyzed in comparison to the 3R4F reference cigarette. SHS was generated by an automatic environmental tobacco smoke emitter (AETSE) in an enclosed space with a volume of 2.88 m³. PM concentrations (PM10, PM2.5, PM1) were measured with a laser aerosol spectrometer followed by statistical analysis. The two strongest Marlboro brands (Red and Red without additives) showed the highest PM concentrations of all tested cigarettes. The measured mean concentrations Cmean of PM10 increased up to 1458 µg/m³ for the Marlboro Red without additives (PM2.5: 1452 µg/m³, PM1: 1263 µg/m³). The similarly strong Marlboro Red showed very similar PM values. The second strongest type Marlboro Gold showed 36% (PM10, PM2.5) and 32% (PM1) lower values, respectively. The “lightest” type Marlboro Silver Blue showed 54% (PM10, PM2.5) or 50% (PM1) lower PM values. The results indicate that the lower the tar, nicotine, and carbon monoxide amounts, as well as the longer the cigarette filter, the lower are the PM levels. An influence of additives could not be determined.
Particulate matter emitted during autopsies can serve as a vector for numerous viruses or bacteria and can lead to infections. Reducing the exposure of those particles in indoor working environments is, therefore, an important issue. To assess the health risk for employees in forensic medicine, we measure particulate matter in the ambient air during autopsies by using an aerosol spectrometer. The autopsies were performed with either an ordinary oscillating saw or an adapted saw with a suction unit. The particle emissions from both saws were compared to each other in order to evaluate whether a technical adaption leads to a particle reduction. Furthermore, the particle exposure reduction by wearing a face mask and variations in the background concentration in the room were analyzed. High particle concentrations were measured while using the ordinary saw. By using the adapted saw or wearing a face mask, the particle exposure could mostly be avoided. On the majority of the working days, an increase in the background concentration could be observed. Based on this knowledge, the use of a proper suction unit and wearing a face mask during autopsies is necessary. Besides, it is important to have sufficient ventilation in the room so that long-lasting high background concentrations can be prevented.
Introduction: Potential health damage by environmental emission of tobacco smoke (environmental tobacco smoke, ETS) has been demonstrated convincingly in numerous studies. People, especially children, are still exposed to ETS in the small space of private cars. Although major amounts of toxic compounds from ETS are likely transported into the distal lung via particulate matter (PM), few studies have quantified the amount of PM in ETS. Study aim The aim of this study was to determine the ETS-dependent concentration of PM from both a 3R4F reference cigarette (RC) as well as a Marlboro Red brand cigarette (MRC) in a small enclosed space under different conditions of ventilation to model car exposure.
Method: In order to create ETS reproducibly, an emitter (ETSE) was constructed and mounted on to an outdoor telephone booth with an inner volume of 1.75 m3. Cigarettes were smoked under open- and closed-door condition to imitate different ventilation scenarios. PM2.5 concentration was quantified by a laser aerosol spectrometer (Grimm; Model 1.109), and data were adjusted for baseline values. Simultaneously indoor and outdoor climate parameters were recorded. The time of smoking was divided into the ETS generation phase (subset "emission") and a declining phase of PM concentration (subset "elimination"); measurement was terminated after 10 min. For all three time periods the average concentration of PM2.5 (Cmean-PM2.5) and the area under the PM2.5 concentration curve (AUC-PM2.5) was calculated. The maximum concentration (Cmax-PM2.5) was taken from the total interval.
Results: For both cigarette types open-door ventilation reduced the AUC-PM2.5 (RC: from 59 400 +/- 14 600 to 5 550 +/- 3 900 mug*sec/m3; MRC: from 86 500 +/- 32 000 to 7 300 +/- 2 400 mug*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 600 +/- 150 to 56 +/- 40 mug/m3, MRC from 870 +/- 320 to 75 +/- 25 mug/m3; p < 0.001) by about 90%. Cmax-PM2.5 was reduced by about 80% (RC: from 1 050 +/- 230 to 185 +/- 125 mug/m3; MRC: from 1 560 +/-500 mug/m3 to 250 +/- 85 mug/m3; p < 0.001). In the subset "emission" we identified a 78% decrease in AUC-PM2.5 (RC: from 18 600 +/- 4 600 to 4 000 +/- 2 600 mug*sec/m3; MRC: from 26 600 +/- 7 200 to 5 800 +/- 1 700 mug*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 430 +/- 108 to 93 +/- 60 mug/m3; MRC: from 620 +/- 170 to 134 +/- 40 mug/m3; p < 0.001). In the subset "elimination" we found a reduction of about 96-98% for AUC-PM2.5 (RC: from 40 800 +/- 11 100 to 1 500 +/- 1 700 mug*sec/m3; MRC: from 58 500 +/- 25 200 to 1 400 +/- 800 mug*sec/m3; p < 0.001) and Cmean-PM2.5 (RC: from 730 +/- 200 to 27 +/- 29 mug/m3; MRC: from 1 000 +/- 450 to 26 +/- 15 mug/m3; p < 0.001). Throughout the total interval Cmax-PM2.5 of MRC was about 50% higher (1 550 +/- 500 mug/m3) compared to RC (1 050 +/- 230 mug/m3; p < 0.05). For the subset "emission" - but not for the other periods - AUC-PM2.5 for MRC was 43% higher (MRC: 26 600 +/- 7 200 mug*sec/m3; RC: 18 600 +/- 4 600 mug*sec/m3; p < 0.05) and 44% higher for Cmean-PM2.5 (MRC: 620 +/- 170 mug/m3; RC: 430 +/- 108 mug/m3; p < 0.05).
Conclusion: This method allows reliable quantification of PM2.5-ETS exposure under various conditions, and may be useful for ETS risk assessment in realistic exposure situations. The findings demonstrate that open-door condition does not completely remove ETS from a defined indoor space of 1.75 m3. Because there is no safe level of ETS exposure ventilation is not adequate enough to prevent ETS exposure in confined spaces, e.g. private cars. Additionally, differences in the characteristics of cigarettes affect the amount of ETS particle emission and need to be clarified by ongoing investigations.
In many neural systems anatomical motifs are present repeatedly, but despite their structural similarity they can serve very different tasks. A prime example for such a motif is the canonical microcircuit of six-layered neo-cortex, which is repeated across cortical areas, and is involved in a number of different tasks (e.g. sensory, cognitive, or motor tasks). This observation has spawned interest in finding a common underlying principle, a ‘goal function’, of information processing implemented in this structure. By definition such a goal function, if universal, cannot be cast in processing-domain specific language (e.g. ‘edge filtering’, ‘working memory’). Thus, to formulate such a principle, we have to use a domain-independent framework. Information theory offers such a framework. However, while the classical framework of information theory focuses on the relation between one input and one output (Shannon’s mutual information), we argue that neural information processing crucially depends on the combination of multiple inputs to create the output of a processor. To account for this, we use a very recent extension of Shannon Information theory, called partial information decomposition (PID). PID allows to quantify the information that several inputs provide individually (unique information), redundantly (shared information) or only jointly (synergistic information) about the output. First, we review the framework of PID. Then we apply it to reevaluate and analyze several earlier proposals of information theoretic neural goal functions (predictive coding, infomax and coherent infomax, efficient coding). We find that PID allows to compare these goal functions in a common framework, and also provides a versatile approach to design new goal functions from first principles. Building on this, we design and analyze a novel goal function, called ‘coding with synergy’, which builds on combining external input and prior knowledge in a synergistic manner. We suggest that this novel goal function may be highly useful in neural information processing.
An information-theoretic approach to numerically determine the Markov order of discrete stochastic processes defined over a finite state space is introduced. To measure statistical dependencies between different time points of symbolic time series, two information-theoretic measures are proposed. The first measure is time-lagged mutual information between the random variables Xn and Xn+k, representing the values of the process at time points n and n + k, respectively. The measure will be termed autoinformation, in analogy to the autocorrelation function for metric time series, but using Shannon entropy rather than linear correlation. This measure is complemented by the conditional mutual information between Xn and Xn+k, removing the influence of the intermediate values Xn+k−1, …, Xn+1. The second measure is termed partial autoinformation, in analogy to the partial autocorrelation function (PACF) in metric time series analysis. Mathematical relations with known quantities such as the entropy rate and active information storage are established. Both measures are applied to a number of examples, ranging from theoretical Markov and non-Markov processes with known stochastic properties, to models from statistical physics, and finally, to a discrete transform of an EEG data set. The combination of autoinformation and partial autoinformation yields important insights into the temporal structure of the data in all test cases. For first- and higher-order Markov processes, partial autoinformation correctly identifies the order parameter, but also suggests extended, non-Markovian effects in the examples that lack the Markov property. For three hidden Markov models (HMMs), the underlying Markov order is found. The combination of both quantities may be used as an early step in the analysis of experimental, non-metric time series and can be employed to discover higher-order Markov dependencies, non-Markovianity and periodicities in symbolic time series.
Parodontitis ist eine chronisch entzündliche nichtübertragbare Erkrankung, die alle Anteile des Zahnhalteapparates (Parodonts) betrifft und dort weitgehend irreversible Schäden verursacht. Schätzungen legen nahe, dass in Deutschland ca. 10 Mio. Menschen an einer schweren Parodontitis erkrankt sind. Parodontitis zeigt über viele Jahre zumeist wenige oder nur milde Symptome, die von den Patienten oft nicht wahrgenommen oder richtig eingeordnet werden. Fehlendes Bewusstsein kann dazu führen, dass zahnärztliche Behandlung erst in einem fortgeschrittenen Erkrankungsverlauf in Anspruch genommen wird, wenn umfangreiche Therapiemaßnahmen notwendig geworden sind und sich die Prognose für den Erhalt der Zähne verschlechtert hat. Der parodontale Screeningindex (PSI) ist ein einfaches und schnelles Instrument, mit dem die Notwendigkeit weiterführender diagnostischer Maßnahmen beurteilt werden kann. Der Index wird mittlerweile bei vielen Patienten durchgeführt. Trotzdem bleiben die Versorgungszahlen niedrig und hinter dem zurück, was für das Absenken der bestehenden Parodontitislast notwendig wäre. Jede Zahnarztpraxis muss in der Lage sein, Parodontitistherapie umzusetzen. Fachzahnärzte oder Spezialisten können die allgemeinzahnärztlichen Kollegen wesentlich bei der Behandlung von schweren Formen von Parodontitis unterstützen. Dazu ist eine Aufwertung des Faches in der universitären Ausbildung erforderlich, aber auch die zunehmende postgraduale Ausdifferenzierung von Spezialisten oder Fachzahnärzten für Parodontologie. Die neuen Behandlungsrichtlinien für die Parodontaltherapie (PAR-Therapie) erlauben die Versorgung der parodontal erkrankten Patienten auf Basis international anerkannter wissenschaftlicher Standards und verbessern damit die Rahmenbedingungen für die Parodontitistherapie in der zahnärztlichen Praxis.
Introduction: In this article the personal study and life situation of parents who are also medical students at the Medical School of the Goethe University Frankfurt am Main is discussed. There is a special focus on the topics "studying with children" and "family-friendly university", which have been present in discussions about university development and in the daily life of academics, especially during the last decade. The workgroup "Individual Student Services" at the medical faculty at the Goethe University tries to meet the necessities of the individual study courses and to support the study success with a new counselling and student service concept.
Methods: The experience of parents studying medicine was recorded in semi-structured interviews (Date: April 2010), which were held as part of the sponsored pilot project on part-time medical studies ("Pilot Project Part-time Medical Studies"). Additionally, study results from the Medical School of the Goethe University Frankfurt am Main were integrated as well as a literature analysis.
Results: It was found that the teaching demands and support services, which have been suggested and needed for years now, have been partially implemented and are without sufficient support at the faculty level to date. Thus the current situation of medical students with children is still difficult and seems a big challenge for everyone involved.
Solution: As part of the "Individual Student Services" a new pilot project on part-time medical studies was established in November 2009. Only the use of new, unconventional and innovative ideas allows universities to adequately support the changing and heterogeneous student population and support them to successfully completing their medical studies.
Paraneoplastic cerebellar degeneration associated with lymphoepithelial carcinoma of the tonsil
(2013)
Background: Paraneoplastic cerebellar degeneration (PCD) is a classical tumor-associated, immune-mediated disease typically associated with gynecological malignancies, small-cell lung-cancer or lymphoma.
Case presentation: Here we present the case of a 38-year old male with an over 12 months rapidly progressive cerebellar syndrome. Extensive diagnostic workup revealed selective hypermetabolism of the right tonsil in whole-body PET. Histological examination after tonsillectomy demonstrated a lymphoepithelial carcinoma of the tonsil and the tongue base strongly suggesting a paraneoplastic cause of the cerebellar syndrome. To the best of our knowledge this is the first case of an association of a lymphoepithelial carcinoma, a rare pharyngeal tumor, with PCD.
Conclusions: In cases of classical paraneoplastic syndromes an extensive search for neoplasms should be performed including whole-body PET to detect tumors early in the course of the disease.
Biophysical parameters can accelerate drug development; e.g., rigid ligands may reduce entropic penalty and improve binding affinity. We studied systematically the impact of ligand rigidification on thermodynamics using a series of fasudil derivatives inhibiting protein kinase A by crystallography, isothermal titration calorimetry, nuclear magnetic resonance, and molecular dynamics simulations. The ligands varied in their internal degrees of freedom but conserve the number of heteroatoms. Counterintuitively, the most flexible ligand displays the entropically most favored binding. As experiment shows, this cannot be explained by higher residual flexibility of ligand, protein, or formed complex nor by a deviating or increased release of water molecules upon complex formation. NMR and crystal structures show no differences in flexibility and water release, although strong ligand-induced adaptations are observed. Instead, the flexible ligand entraps more efficiently water molecules in solution prior to protein binding, and by release of these waters, the favored entropic binding is observed.