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The influence of the filling and handling process on the microbial contamination rate of syringes
Get PDFFragestellung: Zweck dieser Arbeit war, den Einfluss einer Aufziehkanüle sowie eines Desinfektionsmaßnahmenbündels auf die mikrobielle Kontaminationsrate von Spritzen zu untersuchen, die aus 10-ml-NaCl-Kunststoffampullen (mit Abdrehverschluss und Fingerschutz) aufgezogen wurden. Es wurden drei Aufziehmethoden verglichen. Methode 1 bestimmte die Kontaminationsrate ohne Kanüle und ohne Desinfektionsmaßnahmen, Methode 2 bestimmte sie ohne Kanüle, jedoch mit Desinfektionsmaßnahmen (Hände-, Flächen- und Ampullendesinfektion). Methode 3 bestimmte die Kontaminationsrate mit Desinfektionsmaßnahmen sowie mit Kanüle.
Methoden: Im Stationsstützpunkt einer fachübergreifenden Intensivstation wurden insgesamt 500 Spritzen (10 ml) aus NaCl-Ampullen aufgezogen. Pro Methode (1–3) kamen 150 Spritzen zum Einsatz. 50 NaCl-Fertigspritzen fungierten als Negativkontrollen. Alle Proben wurden unter einer Sicherheitswerkbank der Klasse II (LAF-Werkbank) membranfiltriert und die Filter auf Columbia-Blutagarplatten übertragen. Nach dreitägiger Bebrütung bei 37 °C sowie anschließender elftägiger Bebrütung bei 22 °C wurden gewachsene Kolonien per MALDI-TOF ausgewertet. In einem Zusatzversuch wurde Methode 1 unter ITS-ähnlichen Bedingungen im Labor wiederholt. 75 Proben wurden unter LAF-Werkbank in aerobe und 75 Proben in anaerobe Blutkulturflaschen überführt. Die Bebrütung erfolgte bei 37 °C für 14 Tage, die Auswertung positiver Flaschen per MALDI-TOF.
Resultate: Von 500 auf der ITS aufgezogenen Spritzen zeigten nur drei bakterielle Kontamination. Pro Methode (n = 150) war jeweils eine Spritze betroffen (0,67 % Kontaminationsrate). Alle nachgewiesenen Kontaminanten zählten zur Familie der Micrococcaceae. Die Kontaminationsrate zeigte keine statistisch signifikante Abhängigkeit von der Methode (jeweils α = 0,05, p > 0,999 im Methodenvergleich). Die Negativkontrollen waren kontaminationsfrei. Der Zusatzversuch (n = 150) zeigte eine leicht höhere Kontaminationsrate (2,67 %), diese aber im Vergleich mit Methode 1 des Hauptversuchs keine statistisch signifikante Abhängigkeit von der mikrobiologischen Ansatzmethode (α = 0,05, p = 0,371). Nachgewiesen wurden aerobe und fakultativ anaerobe Sporenbildner.
Schlussfolgerungen: Die Resultate deuten darauf hin, dass bei der Entnahme aus der verwendeten NaCl-Kunststoffampulle auf eine Aufziehkanüle verzichtet werden kann, wenn mit aseptischer No-Touch-Technik gearbeitet wird. Das Aufziehen mittels Kanüle erwies sich in der Umsetzung zudem als umständlicher. Desinfektionsmaßnahmen hingegen beugen Kontamination durch Handhabungsfehler vor. Nur auf die Ampullendesinfektion könnte bei Beachtung gründlicher No-Touch-Technik in einem vor Durchgangsverkehr geschützten Umfeld sowie kontaminationsgeschützter Lagerung der Ampullen ggf. verzichtet werden. Da sich Kontaminationen auch bei hoher Umsicht nicht gänzlich verhindern lassen, können Fertigspritzen eine Alternative sein.Objective: The purpose of this study was to investigate the benefit of a cannula and a disinfection bundle on the microbial contamination rate of syringes drawn up from 10 ml NaCl plastic ampoules (with twist-off cap and finger protection). Three methods of drawing up a syringe were compared. Method 1 examined the contamination rate without cannula and without disinfection measures, method 2 without cannula but with disinfection measures (hand, surface and ampoule disinfection). Method 3 examined the contamination rate with disinfection measures and with a cannula.
Methods: A total of 500 syringes (10 ml) were drawn up at the nurses station of a multidisciplinary intensive care unit. For each method (1–3) 150 syringes were used, 50 prefilled NaCl syringes served as negative controls. Membrane filtration was used to process all samples under laminar air flow workbench. Subsequently, the filters were transferred to Columbia blood agar. After three days of incubation at 37°C followed by eleven days of incubation at 22°C, colonies were analysed by MALDI-TOF. In an additional experiment, method 1 was repeated under ITS-like conditions in the laboratory. 75 samples were transferred to aerobic and 75 samples to anaerobic blood culture bottles under laminar air flow workbench. Incubation was carried out at 37°C for 14 days, positive bottles were analysed by MALDI-TOF.
Results: Of 500 syringes drawn up at the nurses station only three showed bacterial contamination. Only one syringe per method (n = 150) was affected (0.67 % contamination rate). All contaminants were bacteria of the Micrococcaceae family. The contamination rate showed no statistically significant dependence on the method (Fisher’s exact test, α = 0.05, p > 0.999 in each case). The negative controls showed no contamination. The additional experiment (n = 150) showed a slightly higher contamination rate (2.67 %). However, the contamination rate showed no statistically significant dependence on the microbiological preparation method when compared to method 1 of the main experiment (Fisher’s exact test, α = 0.05, p = 0.371). Aerobic and facultative anaerobic spore-forming bacteria were detected.
Conclusions: The results indicate that it is possible to draw up syringes from the NaCl plastic ampoules used without a cannula. The prerequisite is an aseptic non-touch technique. Drawing up a syringe using a cannula even proved to be more inconvenient in practice. However, disinfection measures prevent contamination due to handling errors. Only under conditions of aseptic non-touch technique, a protected environment and contamination-protected storage of the ampoules there might be no need for ampoule disinfection. As contamination cannot be completely prevented despite a high level of caution, prefilled syringes could be an alternative
Comparison of four CMD screening tests in anamnestically asymptomatic patients
Get PDFEinleitung:
Bei einer jährlichen Inzidenz von 3,9 % für craniomandibuläre Dysfunktion (CMD) fordert die deutsche Justiz vor jeder zahnärztlichen Therapie die Abklärung de-/kompensierter Funktionsstörungen. Bisher haben sich vier CMD-Screeningtests etabliert: CMD Kurzbefund, CMD-Screening, Präventives Strukturelles Belastungs Screening (PSBS) und Präventive Manuelle Strukturanalyse (PMSA). In der Vergangenheit ist über deren Notwendigkeit diskutiert worden. Diesbezüglich wurden in dieser Studie anamnestisch symptomlose Personen auf das Vorliegen kompensierter Funktionsstörungen untersucht. Weiterhin wurden die vier CMD Screeningtests unter Nutzung der Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) als Referenzstandard verglichen. Weitere explorative Fragen bezüglich Prävalenzen und Diagnostik wurden erörtert.
Material und Methoden:
Es handelte sich um eine prospektive explorative klinische Querschnittstudie, an der in einem Zeitraum von 12 Monaten 200 anamnestisch symptomlose Testpersonen im Alter von 10 50 Jahren teilnahmen. Diese wurden mittels PMSA, PSBS, CMD Screening, CMD Kurzbefund und DC/TMD Achse I bezüglich fünf DC/TMD-Diagnosen untersucht. Die DC/TMD Achse I diente als Referenzstandard. Es wurden Sensitivität, Spezifität, positive und negative prädiktive Vorhersagewerte, 95 % Konfidenzintervalle, Prävalenzen, Mittelwerte, Meridiane, Standardabweichungen und p-Werte ermittelt. Die Ergebnisse wurden mit und ohne DC/TMD-Diagnosealgorithmus dargestellt.
Ergebnisse:
Die vier Screenings detektierten bei anamnestisch symptomlosen Personen 0,0 15,0 % kompensierte Arthralgie-Befunde, 14,5-20,0 % beginnende Diskusverlagerungen, 34,5-49,5 % versteckte Muskelbefunde, 0,5-1,0 % Diskusverlagerungen mit Mundöffnungseinschränkungen und 0,0-0,5 % kompensierte degenerative Gelenkerkrankungen (DGE). Dabei traten höchstens zwei Befunde zeitgleich auf. Zum Teil wichen die Tests signifikant voneinander und von DC/TMD ab. Latente Befunde waren mit DC/TMD wegen des Diagnosealgorithmus nicht nachweisbar. Isometrische und palpatorische Tests unterschieden sich nicht signifikant voneinander. Die Palpationskombination aus Mm. masseter/temporalis/digastricus venter anterior/posterior sowie die passive Kompression in dorsolateraler Richtung besaßen die signifikant höchsten Prävalenzen kompensierter Befunde.
Schlussfolgerung:
Kompensierte Befunde können bei anamnestisch symptomlosen Personen auftreten, weshalb Screenings notwendig sind. Der CMD Kurzbefund ist bedingt zur Detektion kompensierter DGE und nicht für Arthralgie-Befunde nutzbar. Die anderen Screenings sind zur Detektion aller fünf DC/TMD-Diagnosen gut einsetzbar. Die DC/TMD sind für Studien mit anamnestisch symptomlosen Personen nicht der beste aber derzeit der am besten geeignete Referenzstandard.
Die passive Kompression in dorsolateraler Richtung ist ausreichend. Bei den CMD-Screeningtests sollten die Mm. masseter/temporalis/digastricus venter anterior/posterior palpiert werden.Introduction:
With an annual incidence rate of 3,9 % for craniomandibular dysfunction (CMD), the German judiciary requires diagnostic confirmation of de-/compensated dysfunction prior to any dental therapy. To date, four CMD screening tests have been established: CMD Short Finding, CMD Screening, Preventive Structural Stress Screening (PSSS) and Preventive Manual Structural Analysis (PMSA). The needs of CMD screening tests have been debated. In this regard, anamnestically asymptomatic patients are examined for the presence of compensated dysfunctions. Furthermore, these four screening tests are compared using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) as a reference standard. Further exploratory questions on prevalence and diagnostics are also discussed.
Material and Methods:
This prospective exploratory clinical cross-sectional study involves 200 anamnestically asymptomatic patients ages 10 to 50 who participated over 12 months. The patients were evaluated using the PMSA, PSSS, CMD-Short Finding, CMD-Screening, and DC/TMD Axis I tests regarding the five DC/TMD diagnoses. In addition, DC/TMD Axis I serves as the reference standard. The following metrics are used: sensitivity, specificity, positive and negative predictive values, 95 % confidence intervals, prevalences, means, meridians, standard deviations, and p values. The results are presented with and without the DC/TMD diagnostic algorithm.
Results:
In anamnestically asymptomatic patients, compensated CMD findings were detectable in all screenings: 0,0-15,0 % Arthralgia, 14,5-20,0 % Disc Displacement with reduction, 34,5 49,5 % Myogenic Pain, 0,5-1,0 % Disc Displacement without reduction with limited opening, and 0,0 0,5 % Degenerative Joint Disease (DJD). At most, two findings co-occurred. In some cases, the CMD screening tests differed significantly from each other and from DC/TMD. Latent findings were not detectable with DC/TMD due to the diagnostic algorithm. Isometric and palpatory tests did not significantly differ. The palpation combination of the masseter muscle/temporalis muscle/digastric muscle anterior/posterior bellies, and the passive compression in the dorsolateral direction exhibited the highest significant prevalences of compensated findings.
Conclusion:
The presence of compensated findings in anamnestically asymptomatic subjects confirms the forensic significance of CMD screening tests. The CMD-Short Finding test is of limited use for detecting compensated DJD and is not suitable for arthralgia findings. The other CMD screening tests are helpful in detecting all five DC/TMD diagnoses. Moreover, DC/TMD I is not the best option but is currently the best possible reference standard for scientific work with anamnestically asymptomatic patients. Passive compression in the dorsolateral direction is sufficient. For CMD screening tests, the masseter muscle/temporalis muscle/digastric muscle anterior/posterior bellies should be palpated
Self-Similar Phase Diagram of the Fibonacci-Driven Quantum Ising Model
Get PDFWe study a stroboscopic quantum Ising model with Fibonacci dynamics. We use its boundary spin correlation functions in long but finite chains to identify regions in the phase diagram which exhibit Majorana zero modes (MZM) as well as Majorana golden-ratio modes (MGM). We find that these regions evolve in a self-similar manner with increasing simulation time and identify the self-similarity transform which governs this evolution of the phase diagram. Integrability-breaking perturbations lead to a temporal decay of the boundary spin correlations, ultimately limiting the self-similarity of the phase diagram. Our predictions are testable with current quantum information processors
Geometric and demographic effects explain contrasting fragmentation-biodiversity relationships across scales
Get PDFThere is consensus that habitat loss is a major driver of biodiversity loss, while the effects of fragmentation, given a constant total habitat amount, are still debated. Here, we use a process-based metacommunity model to show how scale- and context-dependent fragmentation–biodiversity relationships can emerge from the interplay of two types of fragmentation effects – geometric and demographic. Geometric effects arise from the spatial distributions of species and landscape modification, whereas demographic effects reflect long-term changes in species demographic rates following landscape modification. Our spatial model considers sessile individuals in a heterogeneous landscape and dynamically simulates the processes of species reproduction, dispersal, competition, mortality, and immigration. We introduce a novel approach to partition geometric and demographic fragmentation effects that is based on model outputs directly after landscape modification and after a phase of community dynamics in the modified landscape. In detailed simulation experiments, we assessed how key ecological processes and factors, such as dispersal, habitat heterogeneity, and edge effects, influence geometric, demographic and net fragmentation effects across spatial scales. We found that increasing intraspecific aggregation due to short dispersal and/or environmental autocorrelation increased positive geometric fragmentation effects at the landscape scale. In our model, negative demographic fragmentation effects emerged at the local and landscape scale due to high dispersal mortality in the matrix and due to negative edge effects. We showed that the model can simultaneously predict positive fragmentation–biodiversity relationships at the local scale and negative relationships at the landscape scale as well as context-dependent variation of these relationships at the landscape scale. We conclude that the framework of geometric and demographic effects can reconcile previous apparently conflicting results and hopefully unlock and advance the debate on biodiversity changes in modified landscapes
Seismic-based detection, location and identification of volcano-induced landslides: a feasibility study based on the 2018 Anak Krakatau volcano flank collapse
Get PDFThe 22 December 2018 Anak Krakatau volcanic flank collapse triggered a devastating tsunami along the Sunda Strait, highlighting the need for an early warning system to detect both volcanic collapse and landslide-triggered tsunami from seismic data. Seismically, massive landslides exhibit a deficiency in high-frequency radiation compared to tectonic earthquakes, classifying them as long-period events. In order to use seismic signals for tsunami early warning, the analysis must rely heavily on stations at close distances, particularly because slower-traveling surface waves are required for a good location. In this study, we used spectral analysis to distinguish the 2018 flank collapse from typical tectonic earthquakes and utilized long-period back-projection (40–70 s) of surface wave envelopes to assess its location. Using the Indonesian seismic network, we conducted spectral analysis of the first 100 s of seismic data, with recordings from epicentral distances of 1.0°–2.5°. We confirmed a systematic deficiency of high frequencies in landslide events, enabling the use of a simple frequency ratio to discriminate between earthquakes and landslides. The location was then determined through back-projection within 3 minutes after the event initiation. Our results indicate that the Indonesian seismic network is viable for back-projection, with expected response times within 3–4 minutes at volcanoes with high tsunami potential due to subaerial flank collapse. We conclude by considering practicalities of implementing this approach in operational tsunami early warning systems
Zur Kenntnis des Verhaltens nachbarlicher Gewebe bei bösartigen Tumoren der Tiere
Get PDFDigitalisat der Ausgabe von 1912, erschienen 202
Noninvasive detection of lower extremity artery disease using multi-site photoplethysmographic signals and machine learning
Get PDFLower extremity stenosis (LES) is a prevalent cardiovascular condition and a strong indicator of systemic arteriosclerosis. Existing diagnostic methods are invasive or operator-dependent and often unavailable at the primary care level. Here, we propose a non-invasive screening method based on morphological features extracted from multi-site PPG signals that were calculated from multi-site photoplethysmography measurements during a proof-of-concept clinical study at University Hospital Tübingen. Machine learning methods were used to classify 42 patients with 2 measurements each at four locations (i.e., a total of 84 measurements and 336 signals) into either the control or stenosis group. An overall classification accuracy of 82.6% (sensitivity: 0.750, specificity: 0.865) is achieved. This result is clinically relevant and shows that the selected features are effective for detecting stenosis and could be used as a screening method at the primary physician level
Nb:TiO2 Protection Layers for FTO-based Cathodes for CO2 Reduction Under Neutral Conditions
Get PDFWith the rising anthropogenic CO2 concentrations in the atmosphere and the growing interest in converting solar energy into value-added products, interest in (photo)electrochemical reduction of CO2 is increasing. A key component for this process is an optically transparent and electrically conductive substrate, usually in the form of a transparent conducting oxide (TCO) film deposited on glass. However, most traditional TCO materials, such as fluorine-doped SnO2 (FTO) or tin-doped In2O3 (ITO), are not stable under cathodic conditions. TiO2 has been widely reported as an excellent protection layer material in photo-electrochemical (PEC) research, and niobium is one prospective dopant to improve its conductivity. In this work, we demonstrate that commercial FTO glass can be protected against (photo)corrosion under cathodic reaction conditions in pH-neutral electrolytes by direct-current sputtering of thin Nb-doped TiO2 (Nb:TiO2) overlayers. Combined with a pre-deposition FTO etching procedure, the Nb:TiO2-covered FTO electrode offers excellent electrochemical stability while maintaining good transparency and conductivity
Typical thermalization of low-entanglement states
Get PDFProving thermalization from the unitary evolution of closed quantum systems is one of the oldest questions that is still only partially resolved. Efforts led to various versions of the eigenstate thermalization hypothesis (ETH), which implies thermalization under certain conditions. Whether the ETH holds in specific systems is however difficult to verify from the microscopic description of the system. In this work, we focus on thermalization under local Hamiltonians of low-entanglement initial states, which are operationally accessible in many natural physical settings, including schemes for testing thermalization in experiments and quantum simulators. We prove thermalization of these states under precise conditions that have operational significance. More specifically, motivated by arguments of unavoidable finite resolution, we define a random energy smoothing on local Hamiltonians that leads to local thermalization when the initial state has low entanglement. Finally we show that this transformation affects neither the Gibbs state locally nor, under generic smoothness conditions on the spectrum, the short-time dynamics
Heterogeneity of the Functional Reserve of Cardiomyocytes
Get PDFIn recent times there had been findings that Ca2+-kinetics in adjacent cells differ from each other, which might be an aspect that influences the efficiency of Ca2+-mediated cardiac function. In addition, the first subgroups of cardiomyocytes have been identified based on molecular genetic differences. However, little is known about the physiological heterogeneity of the contractile function of isolated cardiomyocytes. In the following, I will answer the question of whether these subgroups can be identified and distinguished by their cellular response, and to what extent intervention in the β-adrenergic signaling cascade influences the variability of the cellular signaling response and contributes to a better understanding of cardiomyocyte heterogeneity.
Therefore, I obtained cardiomyocytes by Langendorff isolation from male Wistar rats at an average age of nine weeks. I examined the intracellular Ca2+-kinetics and sarcomere-shortening in stimulated cardiomyocytes, using ratiometric fluorescence microscopy. A control group was compared with one Isoprenaline (β-adrenergic agonist) group and Forskolin (downstream adenylate cyclase agonist) groups. I analyzed the sarcomere length during contraction and relaxation, time to maximal shortening and relaxation time of the sarcomeres, as well as the underlying cytosolic [Ca2+] transient, i.e. Ca2+-transient amplitude, Ca2+-removal time and time to maximal [Ca2+]. Sarcomere length shortening and intracellular Ca2+-dynamics of the untreated cells showed heterogeneity based on the broad scattering of the data collected. Isoprenaline intervention was associated with a positive inotropic response, which was expressed in a significantly greater shortening of the sarcomere length compared to the control
group (p < 0.001), as well as a significantly greater increase in Ca2+ amplitude (p < 0.001) and in systolic [Ca2+] (p = 0.0079). The heterogeneity of contractility, measured as the range of the data, was lower for the Isoprenaline group than for the control-, 0.1 µM Forskolin- and 1 µM Forskolin group but was generally larger for the Ca2+ parameters. 1 µM (p < 0.001) and 10 µM (p < 0.001) Forskolin led to a significant increase in sarcomere-shortening compared to the control group. 10 µM Forskolin was associated with a significantly greater sarcomere length shortening with less heterogeneity than the Isoprenaline intervention. There was a significant increase in the Ca2+ amplitude within all Forskolin groups, but no significant difference to the control group. The distribution of individual cellular responses to Isoprenaline and Forskolin respectively indicated subgroups with differing functional reserve. The greater heterogeneity of the data collected in the Isoprenaline group compared to the Forskolin groups suggests
contributing factors to heterogeneity in the signaling pathways upstream of the adenylate cyclase.Jüngst wurde festgestellt, dass sich die Ca2+-Dynamiken benachbarter Kardiomyozyten unterscheiden, was die Effektivität der Ca2+-vermittelten kontraktilen Funktion des Herzmuskels beeinflussen könnte. Zudem lassen sich molekulargenetisch verschiedene Subgruppen an Kardiomyozyten nachweisen. Bisher ist nur wenig über die physiologische Heterogenität der kontraktilen Funktion isolierter Herzmuskelzellen bekannt. In der vorliegenden Arbeit wird die Frage beantwortet, ob sich auch anhand der kontraktilen Funktion Subgruppen identifizieren lassen und inwieweit ein Eingriff in die β-adrenerge Signalkaskade als physiologischer Stressor die Variabilität der zellulären Signalantwort beeinflusst. Hierzu wurden Langendorff-Isolationen der Herzen von neun Wochen alten männlichen Wistar-Ratten durchgeführt. Ich untersuchte die intrazelluläre Ca2+-Dynamik und Sarkomerlängenverkürzung stimulierter Kardiomyozyten mit einem ratiometrischen Fluoreszenzmikroskop. Eine Kontrollgruppe wurde mit einer Isoprenalin (β-adrenerger Agonist) Gruppe sowie mit Forskolin (nachgeschalteter Adenylatcyclase Agonist)
Gruppen verglichen. Es wurde die Sarkomerlänge im kontrahierten sowie relaxierten Zustand, die Zeit bis zur maximalen Verkürzung sowie die Relaxationszeit der Sarkomere als auch die zugrundeliegende basale und maximale zytosolische [Ca2+], die Ca2+-Amplitude, die Ca2+
-Entfernungszeit und die Zeit bis zur maximalen [Ca2+] analysiert.
Die Sarkomerlängenverkürzung sowie die intrazelluläre Ca2+-Dynamik unbehandelter
Zellen wiesen aufgrund der breiten Streuung der erhobenen Daten Heterogenität auf.
Die Isoprenalin Intervention ging mit einer positiv inotropen Reaktion einher, welche
sich in einer signifikant stärkeren Verkürzung der Sarkomerlänge verglichen mit der
Kontrollgruppe (p < 0,001) äußerte, bei einer signifikant größeren Steigerung in
der Ca2+-Amplitude (p < 0,001) sowie in der systolischen [Ca2+] (p = 0,0079). Die He-
terogenität der Sarkomerlängenverkürzung, gemessen in der Spannweite der Daten, fiel für die Isoprenalin Gruppe geringer aus als für die Kontroll-, 0,1 µM Forskolin und 1 µM Forskolin Gruppe, war jedoch für die Ca2+-Parameter am größten. Die 1 µM (p < 0,001) und 10 µM (p < 0,001) Forskolin Intervention führten zu einer signifikant stärkeren Sarkomerlängenverkürzung als die Kontrollgruppe. Die 10 µM Forskolin Gruppe ging mit einer signifikant stärkeren Sarkomerlängenverkürzung bei gleichzeitig geringerer Heterogenität im Vergleich zur Isoprenalin Intervention einher. In allen Forskolin Gruppen kam es zu einem signifikanten Anstieg der Ca2+
-Amplitude, jedoch ohne signifikanten Unterschied zur Kontrollgruppe. Die Variabilität der zellulären Signalantwort in der Kontroll-, Isoprenalin und Forskolin Gruppe lassen auf funktionelle Subgruppen schließen. Die größere Heterogenität der erhobenen Daten in der Isoprenalin Gruppe verglichen mit den Forskolin Gruppen deutet auf Heterogenitätsfaktoren in den der Adenylatcyclase vorgeschalteten Signalwegen hin