Konzepte zur Aktivierung von photodynamischen Substraten durch tiefes Licht

Photoinduzierte Therapien werden in der Medizin, z.B. gegen Hautkrankheiten oder -krebs genutzt und stetig weiterentwickelt. Dabei ist ein limitierender Faktor die Penetrationstiefe von elektromagnetischer Strahlung, sodass die Anwendung auf oberflächliche und von außen zu erreichende Arealen begrenzt ist. Durch die Kombination eines photodynamischen Substrats mit einem Photosensibilisator/Katalysator unter Verwendung von „tiefem Licht“, welches erst am Wirkort freigesetzt oder generiert wird, kann dieses Problem gelöst werden. In dieser Arbeit werden zwei Konzepte entwickelt, bei denen die drei Komponenten kombiniert und auf ihre synergetische photodynamische Wirkung untersucht werden. Dabei wird zum einen ein PDT-Effekt mit Cerenkov-Lumineszenz als tiefe Lichtquelle untersucht und zum anderen die photoinitiierte Freisetzung von pharmakologisch aktiven Abbauprodukten des Artemisinins. Dabei konnte für das erste Konzept nach Entwicklung und Anwendung einer spektroskopischen Nachweismethode von Singulett-Sauerstoff gezeigt werden, dass die emittierte Cerenkov-Strahlung des Isotops Gallium-68 ausreicht, um einen PDT-Effekt zu initiieren. Dabei konnte geschlussfolgert werden, dass für eine möglichst effiziente Nutzung der Cerenkov-Strahlung als tiefe Lichtquelle, Photosensibilisatoren eingesetzt werden sollten, welche im UV-Bereich hohe Extinktionskoeffizienten aufweisen. Das zweite Konzepte der Aktivierung von Artemisinin durch tiefes Licht konnte nicht vollständig untersucht werden, jedoch wurde eine Funktionalisierungsmethode an SiO2-Nanopartikeln entwickelt, die bei Anwendung auf geeignete UCNPs eine Oberflächendekoration sowohl mit Benzophenon als auch Artemisinin ermöglicht. Bei dieser Funktionalisierung entstandene Moleküle wurden in Hinblick auf deren Aktivität gegen Pankreas-Tumorzellen, als auch auf ihre Triplett-Lebensdauern untersucht. Dabei konnte gezeigt werden, dass ein erhöhtes Verhältnis von Artemisinin zu Benzophenon sowohl in einer erhöhten biologischen Aktivität als auch in einer verkürzten Triplett-Lebensdauer resultieren

Chemical Study of the Interstitial Water Dissolved Organic Matter and Gases in Lake Erie, Cleveland Harbor, and Hamilton Harbour Bottom Sediments - Composition and Fluxes to Overlying Waters

The research on which this report is based was financed in part by the U.S. Department of the Interior, as authorized by the Water Research and Development Act of 1978 (P.L. 95-467).(print) iv, 167, [45] p. : ill., maps ; 29 cm.FINAL REPORT FOR OWRT GRANT A-O59-OHIOItem lacks publication date. Issue date supplied from hand-written year on coverIntroduction -- The Study Area -- Methods and Materials -- Results -- Discussion -- Conclusions -- Selected Bibliographic References -- Tables 1-32 -- Figures 1-36 -- Appendi

Time-dependent integrity during storage of natural surface water samples for the trace analysis of pharmaceutical products, feminizing hormones and pesticides

Monitoring and analysis of trace contaminants such as pharmaceuticals and pesticides require the preservation of the samples before they can be quantified using the appropriate analytical methods. Our objective is to determine the sample shelf life to insure proper quantification of ultratrace contaminants. To this end, we tested the stability of a variety of pharmaceutical products including caffeine, natural steroids, and selected pesticides under refrigerated storage conditions. The analysis was performed using multi-residue methods using an on-line solid-phase extraction combined with liquid chromatography tandem mass spectrometry (SPE-LC-MS/MS) in the selected reaction monitoring mode. After 21 days of storage, no significant difference in the recoveries was observed compared to day 0 for pharmaceutical products, while for pesticides, significant losses occurred for DIA and simazine after 10 days (14% and 17% reduction respectively) and a statistically significant decrease in the recovery was noted for cyanazine (78% disappearance). However, the estrogen and progestogen steroids were unstable during storage. The disappearance rates obtained after 21 days of storage vary from 63 to 72% for the feminizing hormones. Overall, pharmaceuticals and pesticides seem to be stable for refrigerated storage for up to about 10 days (except cyanazine) and steroidal hormones can be quite sensitive to degradation and should not be stored for more than a few days

Sediment Characteristics and Methane Ebullition in Three Subarctic Lakes

Ebullition (bubbling) from climate‐sensitive northern lakes remains an unconstrained source of atmospheric methane (CH4). Although the focus of many recent studies, ebullition is rarely linked to the physical characteristics of lakes. In this study we analyze the sediments of subarctic postglacial lakes and investigate how sediment properties relate to the large spatial variation in CH4 bubble flux, quantified over multiple years using bubble traps. The results show that the sediments from our lakes are rich in total organic carbon, containing 37 kg/m3 on average. This number is roughly 40% higher than the average for yedoma deposits, which have been identified as high CH4 emitters. However, the quantity of total organic carbon is not a useful indicator of high emissions from the study lakes. Neither is the amount of CH4 in the sediment a reliable measure of ebullition potential. Instead, our data point to coarse detritus, partly from buried submerged aquatic vegetation and redeposited peat as spatial controls on fluxes, often in combination with previously established effects of incoming solar radiation and water depth. The results once again highlight the climate sensitivity of northern lakes, indicating that biological responses to warmer waters and increased energy input and heating of organic sediments during longer ice‐free seasons can substantially alter future CH4 emissions

Moving Beyond the Gradient: Social Classes as Group Contexts Defined by Multiple Forms of Capital

Social class is a complex multidimensional phenomenon. Yet social psychologists have typically used indicators of SES or “social rank” to proxy class. Informed by sociology and cultural psychology, we treat social classes as group contexts characterized by the interplay of material, social, and cultural capital. Subjecting three datasets to latent profile analysis (LPA; N = 30,332), we uncover qualitatively distinct class groupings within the U.S. population—each characterized by a unique pattern of capital (Studies 1–3). Consistent with theory in cultural psychology, class formation is guided by a reciprocal relationship between material capital (income and assets) and social capital (interpersonal ties). Across studies, we predict and observe one profile (the “middle/upper class”) that exhibits high material capital but low levels of social capital, and another profile (the “vulnerable workers”) that displays modest material capital but very high social capital. Studies 2 and 3 illuminate the adaptive value of vulnerable workers’ high social capital, with this group reporting similar mental and physical health outcomes to the middle/upper class (Studies 2 and 3) and leveraging their social networks to protect against health impacts of the Covid-19 pandemic (Study 3). Our work reveals that tradeoffs between material and social capital occur most reliably at the group (not individual) level; that class effects are not monotonic, but reflect higher-order interactions between forms of capital; and that LPA can be a fruitful analytic approach when combined with careful theorization, validation of profiles against appropriate covariates, and preregistration

Reasoning about others’ minds attenuates class differences in tests of logical aptitude

Social-class differences in aptitude testing are often attributed to working-class deficits in basic cognitive skills. The present work challenges prevailing deficit narratives with respect to an important cognitive ability: logical reasoning. We argue that many logic tests are rooted in middle-class norms of independence. Given that working-class contexts instead promote interdependent cognitive skills, class differences on logic tests may reflect cultural mismatch rather than poor reasoning ability among working-class individuals. We test these claims in two pre-registered studies (Ntotal = 990). Study 1 reveals that reframing a classic logical reasoning task to be socially relevant (i.e., inferring others’ social attributes) attenuates class-based differences in performance. Study 2 shows that logic problems recruiting theory of mind—reasoning about the thoughts, intentions, and desires of others—most robustly attenuates class differences in performance. Our results have important implications for strength- vs. deficit-centered perspectives on social class and inclusive approaches to testing