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Asymmetrical Use of Appendages in Food Probing by Two Ant Species
Full text linkLateralization, or the presence of left–right asymmetry, is a widespread phenomenon in vertebrates and has been shown to confer various adaptive advantages, as lateralized individuals tend to outperform non-lateralized ones in specific tasks. In contrast, much less is known about lateralization in invertebrates. Further investigation into lateralization in understudied invertebrate groups is crucial for deepening our understanding of its evolutionary origins. In this study, we evaluated asymmetries during food probing behaviors in two ant species, Lasius niger and Linepithema humile. Overall, both species exhibited asymmetries, favoring either a particular leg or antenna when investigating a sugar drop. Interestingly, L. niger favored the right side, while L. humile favored their left. These results imply the absence of a strong driver for a bias on a specific side preference for food probing in ants, but a potential benefit of lateralization in food probing. Supporting this, individuals fully lateralized on the opposite side of the majority were observed in both species. The collective bias found in both species supports the theory that population-level lateralization may have evolved in species that need to coordinate their behaviors. This study provides novel insights into the lateralization of ant behaviors and highlights the need for further research into its evolutionary drivers
Developing Novel Functional Laser-Induced Carbon Nanofibers for Miniaturized Electroanalytical Biosensors
Full text linkElectrochemical sensors are ideal candidates for point-of-care diagnostics due to their low cost, sensitivity, and direct data readout. Nowadays, enzyme-based sensors dominate the electrochemical diagnostics market due to their outstanding selectivity. However, there are some drawbacks related to the use of enzyme like stability issues or high manufacturing costs. This thesis highlights the need for enzyme-free alternatives and provides a comprehensive overview of non-enzymatic sensors and their development. The definition, principles, and typical detection mechanisms of electrochemical sensing are explained. Various conventional strategies for fabricating enzyme-free electrochemical sensors, such as drop-casting, dip-coating, electro- and electroless deposition, screen/inkjet/3D-/roll-to-roll printing, and the emerging technology of laser scribing, are introduced and compared in terms of cost, complexity, mass production capability, and their individual pros and cons. Additionally, considerations regarding selectivity, sensitivity, and biofouling when applying these sensors to different matrices, such as clinical samples (blood, dermal interstitial fluid, sweat, saliva, urine, breath) and non-clinical samples (water from rivers, lakes, seas, food and beverages, cell culture media), are presented. Other challenges and potential solutions related to electrode fouling, measurements under physiological conditions, biocompatibility, long-term stability, storage, practical issues, and efficiency are also discussed.
In this thesis, a non-enzymatic electrochemical sensor based on laser-induced carbon nanofibers (LCNFs) for detecting hydrogen peroxide was developed. The working electrode was laser-scribed on polyimide nanofibers produced by electrospinning. These fibers contained either one or a mixture of both metal salts Pt(II)- and Ni(II)-acetylacetonate, which were converted to nanoparticles embedded within the LCNF during the laser treatment. The resulting nanoparticles consisted either of Pt- or Ni- metals and their oxides, or Pt-Ni-alloyed metal and its oxide in the case of a mixture. In the measurement setup, a Pt-wire and an Ag/AgCl electrode were used as the counter and reference electrodes, respectively, to investigate hydrogen peroxide detection. LCNFs with various compositions of the metal salts were tested towards the catalytic behavior to hydrogen peroxide and their selectivity. The best sensitivity (with a limit of detection (LOD) of 1.4 ± 0.4 μM) in an un-stirred approach was achieved by oxidizing hydrogen peroxide on a pure Pt-LCNF, but this led to unsatisfactory selectivity. Strategies such as increasing the metal content or using polymer coatings were applied to improve selectivity. Drop-coating the electrode with nylon also improved the recovery of hydrogen peroxide spiked in real matrices (undiluted and diluted human serum). Selectivity was further improved by reducing the measurement potential and switching from oxidation to reduction of hydrogen peroxide, although this came at the cost of sensitivity. Additionally, strategies to attach polyoxometalates as alternative catalysts onto the LCNF surface were explored but did not result in sensitive hydrogen peroxide detection.
A second project in this thesis focused on the non-enzymatic electrochemical detection of glucose under physiological conditions. It is well-known that glucose oxidation is catalyzed on Ni-surfaces at an alkaline pH. Therefore, the Pt/Ni-alloyed LCNF described in the previous project was used to efficiently generate a high local pH by an electrochemical pretreatment (-0.9 V for 20 s) on the Pt-sites of the LCNF, enabling glucose measurement on the Ni-sites of the alloy in a consecutive cyclovoltammetry measurement, even though the initial pH of the solution was 7.4. To enable long-term measurements, an electrochemical treatment after each measurement was introduced to clean the catalyst surface. After optimizing (i) the pretreatment, (ii) the catalyst cleaning, (iii) the measurement conditions, and (iv) the data treatment, glucose could be selectively detected in physiologically relevant concentrations with a LOD of 0.3 ± 0.1 mM. Furthermore, the aging of the electrode was investigated, where hydrophobicity is increasing with time, leading to a reduced contact between electrode and solution. To resolve this, a simple Tween-20 incubation was applied prior to measurement. Finally, the electrode performance was not affected after sterilization, and a recovery of 95 ± 10% in spiked, diluted human serum was achieved.
In the last project, pure Ni-LCNF were laser-scribed as a 3-electrode system (LCNF was used as the working, counter, and reference electrode) and used to detect glucose in simulated breath. Glucose solutions with concentrations similar to those present in lung fluids were nebulized, captured on the porous LCNFs, and electrochemically measured in NaOH solution. With optimized manufacturing, glucose-capturing, and measurement parameters, glucose was detected selectively using cyclovoltammetry and a ratiometric data readout. To simulate variations in lung fluid concentration (reflecting blood sugar level variations), various glucose concentrations of the nebulized solutions were captured, measured, and could be distinguished from each other
Nur noch „umweltverträglich“. Interview von Michael Höfling mit Immobilienexperte Tobias Just
No full textInhaled nebulised medications in palliative care - a survey among palliative care practitioners in Germany
Full text linkBackground
In palliative care, alternative routes for drug application besides the oral and intravenous administration are frequently necessary. Up-to-date, very little is known about the familiarity, use and perceived relevance of inhalative medications for symptom control among palliative care practitioners.
Methods
We conducted an anonymous online survey among palliative care physicians throughout Germany between 09/2021 and 04/2022. The questionnaire covered participants’ sociodemographics, as well as familiarity, perceived relevance and prescription practices regarding 21 nebulised drugs. Analysis was performed using methods of descriptive statistics.
Results
108 fully completed questionnaires were analysed. Most of the participants were employed in palliative care for 5 + years. The administration of normal saline, mucoactive drugs, bronchodilators and steroids via nebulisation was a widely known and frequently used technique among the participants, as evidenced by its regular use in clinical routine. About 50% of the participants reported to know epinephrine and tranexamic acid for anti-oedematous or haemostyptic effects, respectively. Both drugs were considered “relevant” by more than 60% of the prescribers. Only a minority of participants reported to know and use nebulised opioids, iloprost, several antibiotics, heparin, ketamine and lidocaine.
Conclusions
Our survey shows that nebulised drugs are prescribed and considered relevant in palliative care. However, for several of the mentioned medications only limited data is available regarding use and effectivity. There is also uncertainty to what extent the existing data may be transferable into routine palliative care setting. Therefore, more evidence should be generated
Kreativität im Unterricht durch Verbindung von Musik und Sprache - eine sonderpädagogische Herausforderung
No full textRetrospektive Analyse einer Pilotstudie zur Behandlung der Depression mittels aiTBS
Full text linkDie Therapie der Depression mit Transkranieller Magnetstimulation (TMS) ist seit einiger Zeit Gegenstand der Forschung. Da bisher nicht bekannt ist, wie genau die TMS die Verbesserung der depressiven Symptomatik hervorbringt, ist auch nicht bekannt, wie genau die Impulse appliziert werden müssen, um das bestmögliche Ergebnis zu erreichen. Ein Ansatz zur optimalen Behandlung ist die aiTBS („acclerated intermittent theta burst stimulation“). Vorteile von dieser gegenüber konventionellen TMS-Protokollen sind sowohl die kürzere Gesamtdauer als auch die damit verbundene bessere Eingliederungsmöglichkeit in den klinischen Alltag.
Wir verwendeten ein modifiziertes Protokoll unter der Arbeitshypothese, dass ein beschleunigtes iTBS-Protokoll bessere Ergebnisse erzielt als eine Behandlung mittels konventioneller iTBS.
Es handelte sich um eine Pilotstudie mit kleinen Gruppen von 9 Probanden. Die ersten beiden Gruppen wurden mit aiTBS behandelt. Die erste Gruppe für zwei Wochen, die zweite Gruppe für vier Wochen. Als Vergleichsgruppe dienten die Ergebnisse einer vorangegangen hauseigenen Studie, bei der die Patienten mit neuronavigierter, aber nicht beschleunigter, iTBS behandelt wurden. Die Anwendung erfolgte täglich von Montag bis Freitag und dreimal am Tag. Pro Sitzung wurden 600 Pulse appliziert mit einer Dauer von 15 Minuten zwischen den Sitzungen.
In allen Gruppen kam es während der Behandlung zu einer Besserung der depressiven Symptomatik. Bei der Gruppe 2, die über einen Zeitraum von vier Wochen mit der aiTBS behandelt wurde, sind die Verbesserungen signifikant. Bei Gruppe 1, die gleichbehandelt wurde, allerdings nur für zwei Wochen, hingegen nicht. Weitere Analysen ergaben, dass die Veränderungen zwischen den Gruppen nicht signifikant sind.
Es lässt sich daher zusammenfassen: Alle drei Behandlungsregime führten zu einer Reduktion der Symptomlast, allerdings ist keine Behandlung einer anderen überlegen. Das bedeutet, dass laut unserer Studie das beschleunigte Protokoll keinen Vorteil gegenüber der konventionellen Therapie bringt
Data archive of "Topological insulator constrictions – Dirac particles in a magneto-chiral box"
No full text3. DBIS Community-Workshop : Community-Workshop zum aktuellen Stand der neuen DBIS-Version
Full text linkAn integral representation for the Dirac propagator in the Reissner–Nordström geometry in Eddington–Finkelstein coordinates
Full text linkThe Cauchy problem for the massive Dirac equation is studied in the Reissner–Nordström geometry in horizon-penetrating Eddington–Finkelstein-type coordinates. We derive an integral representation for the Dirac propagator involving the solutions of the ordinary differential equations which arise in the separation of variables. Our integral representation describes the dynamics of Dirac particles outside and across the event horizon, up to the Cauchy horizon
AI modeling for outbreak prediction: A graph-neural-network approach for identifying vancomycin-resistant enterococcus carriers
Full text linkThe isolation of affected patients and intensified infection control measures are used to prevent nosocomial transmission of vancomycin-resistant enterococci (VRE), but early detection of VRE carriers is needed. However, there are still no standard screening criteria for VRE, which poses a significant threat to patient safety. Our study aimed to develop and evaluate an artificial intelligence (AI)-based approach for identifying and predicting of at-risk patients who could assist infection prevention and control staff through a human-in-the-loop approach. We used data from 8,372 patients, combining more than 125,000 movements within our hospital with patient-related information to create time-dependent graph sequences and applied graph neural networks (GNNs) to classify patients as VRE carriers or noncarriers. Our model achieves a macro F1 score of 0.880 on the task (sensitivity of 0.808, specificity of 0.942). The parameters with the strongest impact on the prediction are the codes for clinical diagnosis (ICD) and operations/procedures (OPS), which are integrated as high-dimensional patient node features in our model. We demonstrate that modeling a “living” hospital with a GNN is a promising approach for the early detection of potential VRE carriers. This proves that AI-based tools combining heterogeneous information types can predict VRE carriage with high sensitivity and could therefore serve as a promising basis for future automated infection prevention control systems. Such systems could help enhance patient safety and proactively reduce nosocomial transmission events through targeted, cost-efficient interventions. Moreover, they could enable a more effective approach to managing antimicrobial resistance