share it - The Open Access and Research Data Repository of the University Libraries in Saxony-Anhalt
Not a member yet
91636 research outputs found
Sort by
MLUH-E-412_1, Pernis apivorus (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-412_1, Object: eggshell, Species: Pernis apivorus (Linnaeus, 1758), Preservation: good preservation, Locality_loc.: Zwickau, Locality today: Zwickau, Country: GermanyCollection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 155, Identification by: M. Schönwetter, Aquisition: 1953, Aquired from: Städtisches Naturkundemuseum Zwickau, ex Collection: ex. Coll. Städtisches Naturkundemuseum Zwicka
Satb1 directs the differentiation of TH17 cells through suppression of IL-2 expression
No full textT helper (TH)17 cells are crucial for host defense in barrier organs, and their altered functionality can disrupt tissue homeostasis, increasing the risk of autoimmune diseases. Thus, it is essential to understand the mechanisms controlling TH17 differentiation to develop strategies influencing their role in diseases. Here, we identified Special AT-rich sequence-binding protein 1 (Satb1) as a pioneering factor for TH17 development. Satb1 is highly expressed in TH17 cells, and loss of Satb1 prevents the differentiation of TH17 cells. Consequently, expression of Satb1 in CD4+ T cells is required for the formation of TH17-driven autoimmune diseases. Mechanistically, Satb1 mediates TH17 development through regulating accessibility of the Il2 gene locus and thereby preventing interleukin (IL)-2 signaling early during TH17 differentiation. Hence, suppression of IL-2 expression by Satb1 during TH17 formation is pivotal, suggesting that Satb1 could serve as a novel therapeutic target for treating autoimmune diseases driven by TH17 cells
MLUH-E-279_1, Aquila rapax vindhiana Franklin, 1831, eggshell
No full textInventory No.: MLUH-E-279_1, Object: eggshell, Species: Aquila rapax vindhiana Franklin, 1831, Preservation: complete preservation, Locality_loc.: Baroda, Locality today: Gujarat, Country: IndiaCollector_leg.: General R. M. Betham, Date: 12/12/1897, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 172, Identification by: M. Schönwetter, Aquisition: 1935, Aquired from: Gowland, ex Collection: ex. Coll. C. R. Wood; ex. Coll. E. C. S. Baker; ex. Coll. General R. M. Betham; ex. Coll. Gowlan
MLUH-E-32_3, Falco subbuteo Linnaeus, 1758, eggshell
No full textInventory No.: MLUH-E-32_3, Object: eggshell, Species: Falco subbuteo Linnaeus, 1758, Preservation: complete preservation, Locality_loc.: Harburg, Locality today: Harburg, Country: GermanyCollection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 190, Identification by: M. Schönwetter, Aquisition: 1939, Aquired from: J. F. G. Umlauff, ex Collection: ex. Coll. J. F. G. Umlauf
MLUH-E-192_2, Accipiter nisus nisus (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-192_2, Object: eggshell, Species: Accipiter nisus nisus (Linnaeus, 1758), Preservation: severe damage, Locality_loc.: Oschatz, Locality today: Oschatz, Country: GermanyCollector_leg.: O. Salzmann, Date: 15/06/1927, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 160, Identification by: J. Dahlke, Aquisition: 1933, Aquired from: M. Winter, ex Collection: ex. Coll. M. Winter; ex. Coll. O. Salzma
Effects of haloperidol on cardiac histamine H2 receptors and β-adrenoceptors in isolated mouse and human atrial preparations
No full textThe antipsychotic drug haloperidol is found on the WHO list of essential drugs. In vitro, haloperidol demonstrates binding affinity for various receptors, including histamine H2 receptors (H2Rs). Several cardiac effects of haloperidol are known, but it remains unclear whether H2Rs are involved. Here, the hypothesis was tested that haloperidol has the potential to act as either an agonist or an antagonist of human cardiac H2Rs. The contractile effects of haloperidol were studied in isolated left and right atrial preparations from transgenic mice overexpressing human H2Rs in the heart (H2-TG), and compared to human atrial preparations from adult patients. Haloperidol reduced the histamine-stimulated force of contraction in the human atrial preparations as well as the histamine-stimulated force of contraction and beating rate in the left and right atrial preparations from the H2-TG, respectively. Moreover, haloperidol reduced the isoprenaline-stimulated force of contraction in the human atrial preparations. In the wild-type mouse preparations, haloperidol only reduced the isoprenaline-stimulated beating rate in the right atria, but not the force in the left atria. Principally, haloperidol is capable of acting as an antagonist of both H2Rs and β-adrenoceptors in the human heart. However, the effects are only relevant at very high doses of haloperidol, which are never or seldom achieved in practice
Die schulischen Leistungen geflüchteter Kinder am Ende der Grundschulzeit in Deutschland
No full textQuasi-static dispersion of dusts for the measurement of safety characteristics of hybrid mixtures
No full textKnowledge of the explosion limiting concentrations of explosible materials is
necessary for the design of explosion protection measures. Currently employed
methods of testing the minimum explosible concentration (MEC) of a dust cloud or
the lower explosion limit (LEL) of a hybrid mixture are based on arbitrary
assumptions and possess technical limitations that often lead to values of
MEC/LEL which are unrealistically low or poorly reproducible. The lack of reliable
experimental data of the LEL of hybrid mixtures has led to the development of
theoretical models that, as a quick solution, calculate the LEL of hybrid mixtures
based on single component data.
This research work presents a state-of-the-art method for the experimental
determination of the MEC of a combustible dust cloud or the LEL of a hybrid
mixture. The new setup operates under laminar flow conditions and allows a
uniform suspension of dust particles in an open top acrylic glass tube. Dust cloud
is ignited in a quasi-static state to eliminate the influence of the flow regime on the
ignition and combustion propagation. The dust concentration is measured with the
help of infrared sensors installed a few centimetres above and below the ignition
source.
In order to evaluate the possible influence of flow velocity and ignition energy, the
LEL of hybrid mixtures of lycopodium and titanium with methane have been
measured at four and two flow front velocities, respectively, and three ignition
energies. The results suggest small variations in the LEL, which, under the
consideration of measurement uncertainties, have been regarded negligible.
Based on the mass balance of the fuel mixture and the enthalpy balance of the
whole system, a simple mathematical model for the calculation of the LEL of hybrid
mixtures has been derived. The theoretically calculated values of the LEL of hybrid
mixtures agreed well with the experimental data. By analyzing the modelled as well
as the experimental values, it can be concluded that the LEL values of the
individual components in a hybrid mixture set the upper and lower limit for the LEL
of a hybrid mixture, provided that the results are presented in molar units. How the
LEL of a hybrid mixture changes within these limits with respect to the change in
the mixture composition depends on the interaction of dust and gas during the
combustion.
The ignition and combustion propagation mechanism in lean hybrid mixtures has
been investigated utilizing high-speed videos. The analysis of the videos revealed
that in lean hybrid mixtures of volatile dusts the ignition kernel does not develop
into an autonomously growing reaction zone, but rather serves as an ignition
source for the rest of the fuel. Contrary to the general perception, in hybrid mixtures
at their LEL, the combustion propagation speed does not increase by increasing
the relative amount of gas in the system.Die derzeit verbreiteten Methoden zur Bestimmung der unteren Explosionsgrenze
(UEG) einer Staubwolke oder eines hybriden Gemisches beruhen auf
unrealistische Annahmen und weisen technische Beschränkungen auf, die häufig
zu ultrakonservativen oder schlecht reproduzierbaren Werten der UEG führen. Der
Mangel an zuverlässigen experimentellen Daten der UEG hybrider Gemische
führte zur Entwicklung empirischer Modelle, welche zur Vereinfachung die UEG
der hybriden Gemische auf Grundlage der UEG der einzelnen Komponenten
berechnen.
In dieser Forschungsarbeit wird eine dem Stand der Technik entsprechende
Methode zur experimentellen Bestimmung der UEG einer brennbaren Staubwolke
eines hybriden Gemisches vorgestellt. Der neue Versuchsaufbau arbeitet unter
laminaren Strömungsbedingungen und ermöglicht eine gleichmäßige Verteilung
von Staubpartikeln in einem freibelüfteten Acrylglasrohr. Die Staubwolke wird in
einem quasi-statischen Zustand entzündet, um den Einfluss der
Strömungsverhältnisse auf die Zündung und die Flammenausbreitung zu
verhindern. Die Staubkonzentration wird mit Hilfe von Infrarotsensoren gemessen,
die einige Zentimeter über und unter der Zündquelle angebracht sind.
Um den Einfluss von Strömungsgeschwindigkeit und Zündenergie zu bewerten,
wurde die UEG von Hybridgemischen aus Lycopodium und Titan mit Methan
jeweils bei vier und zwei Strömungsgeschwindigkeiten und drei Zündenergien
gemessen. Die Ergebnisse deuten auf geringe Schwankungen der UEG hin, die
unter Berücksichtigung der Messunsicherheiten als vernachlässigbar angesehen
werden können.
Auf Grundlage der Massenbilanz des Brennstoffs und der Enthalpiebilanz des
gesamten Systems wurde ein einfaches mathematisches Modell für die
Berechnung der UEG von Hybridgemischen abgeleitet. Die vom Modell
berechneten Werte der UEG von Hybridgemischen stimmten gut mit den
experimentellen Daten überein. Die Analyse der modellierten und der
experimentellen Werte lässt den Schluss zu, dass die UEG-Werte der einzelnen
Komponenten im Hybridgemisch die Ober- und Untergrenze für die UEG des
Hybridgemischs festlegen, sofern die Ergebnisse in molaren Einheiten dargestellt
werden. Wie sich die UEG von Hybridgemischen innerhalb dieser Grenzwerte bei
wechselnder Gemischzusammensetzung verändert, hängt von der
Wechselwirkung von Staub und Gas während der Verbrennung ab.
Die Zündung und Flammenausbreitung in mageren Hybridgemischen wurde mit
Hilfe von Hochgeschwindigkeitsvideos untersucht. Die Analyse der Videos ergab,
dass sich in mageren Hybridgemischen aus flüchtigen Stäuben der Zündkern nicht
zu einer eigenständig wachsenden Flamme entwickelt, sondern vielmehr als
Zündquelle für den Rest des Brennstoffs dient. Entgegen der allgemeinen
Auffassung nimmt die Flammengeschwindigkeit in hybriden Gemischen bei ihrer
UEG nicht zu, wenn die relative Gasmenge im System steigt.Literaturverzeichnis: Seite [87]-9
MLUH-E-38_1, Falco eleonorae Géné, 1839, eggshell
No full textInventory No.: MLUH-E-38_1, Object: eggshell, Species: Falco eleonorae Géné, 1839, Preservation: complete preservation, Locality_loc.: Cykladen, Locality today: Cyclades, Country: GreeceCollector_leg.: Dr. T. J. Krüper, Date: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 191, Identification by: M. Schönwetter, ex Collection: ex. Coll. Dr. T. J. Krüper, Additional Information: strug 75 Kr
Laser-induced nano-functional surfaces for enhanced SERS performance
No full textNanostructured metal surfaces play a crucial role in sensing applications, particularly in Surface-Enhanced Raman Spectroscopy (SERS). In this study, laser-induced periodic surface structures (LIPSS) are fabricated on silicon substrates using femtosecond laser irradiation to investigate their formation mechanisms and impact on Raman signal enhancement. By systematically varying the laser fluence and pulse number, their effects are examined on LIPSS periodicity and, consequently, SERS performance. The results reveal that increasing laser fluence from 0.80 to 1.40 J/cm2 significantly reduces LIPSS periodicity due to enhanced Surface Plasmon Polaritons (SPPs) excitation and energy redistribution. LIPSS exhibit elongated elliptical structures at lower pulse numbers, which gradually transition into circular patterns with increasing pulses, driven by electric field redistribution and interference effects. The influence of LIPSS on SERS is systematically analyzed using a thiophenol solution to evaluate Raman signal sensitivity. The results demonstrate that precisely tuned periodicity and depth of LIPSS significantly enhance SERS signals by optimizing localized electromagnetic fields and plasmonic resonance effects. Notably, LIPSS with a periodicity of ∼795 nm exhibited the highest enhancement due to the resonant coupling of SPPs with the excitation laser, while optimal depths (∼352–547 nm) balanced hotspot density and plasmonic efficiency