4,909 research outputs found
To Bind or Not to Bind Collectively? Decomposition of Bargained Wage Differences Using Counterfactual Distributions
Collective bargaining agreements still play an important role in the German wage setting system. Both existing theoretical and empirical studies find that collective bargaining leads to higher wages compared to individually agreed ones. However, the impact of collective bargaining on the wage level may be very different along the wage distribution. As unions aim at compressing the wage distribution, one might expect that for covered workers' wages in the lower part of the distribution workers' individual characteristics may be less important than the coverage by a collective contract. In contrast, the relative importance of workers' individual characteristics may rise in the upper part of the wage distribution, whereas the overall wage difference might decline. Using the newly available German Structure of Earnings Survey (GSES) 1995 and 2001, a cross-sectional linked employer-employee-dataset from German official statistics, this study analyses the difference between collectively and individually agreed wages using a Machado/Mata (2005) decomposition type technique.collective bargaining; wage structure; wage decomposition; quantile regression
Femtosecond photoelectron and photoion spectrometer with vacuum ultraviolet probe pulses
We describe a setup to study ultrafast dynamics in gas-phase molecules using
time-resolved photoelectron and photoion spectroscopy. The vacuum ultraviolet
(VUV) probe pulses are generated via strong field high-order harmonic
generation from infrared femtosecond laser pulses. The band pass characteristic
in transmission of thin indium (In) metal foil is exploited to isolate the
harmonic of the 800 nm fundamental (H9, 14 eV, 89 nm) from all
other high harmonics. The harmonic is obtained with high
conversion efficiencies and has sufficient photon energy to access the complete
set of valence electron levels in most molecules. The setup also allows for
direct comparison of VUV single-photon probe with 800 nm multi-photon probe
without influencing the delay of excitation and probe pulse or the beam
geometry. We use a magnetic bottle spectrometer with high collection efficiency
for electrons, serving at the same time as a time of flight spectrometer for
ions. Characterization measurements on Xe reveal the spectral width of H9 to be
meV and a photon flux of photons/pulse after
spectral filtering. As a first application, we investigate the S excitation
of perylene using time-resolved ion spectra obtained with multi-photon probing
and time-resolved electron spectra from VUV single-photon probing. The time
resolution extracted from cross-correlation measurements is fs for
both probing schemes and the pulse duration of H9 is found to be fs
Zielgerichtete, enzymatisch induzierte in vivo Erzeugung von Licht mittelschemolumineszenter Adamantylylidenadamantan-1,2-dioxetane für die photochemischinduzierte Wirkstofffreisetzung aus Endosomen, photodynamische Therapie schwerzugänglicher Körperregionen und intraoperative Tumordiagnostik
Das Ziel dieses Forschungsvorhabens ist es, Licht mittels Chemolumineszenz direkt im Tumorgewebe zu erzeugen. Es soll also Licht an dem Ort erzeugt werden, wo es für therapeutische und diagnostische Zwecke gebraucht wird und wo keine externen Lichtquellen eingebracht werden können (insbesondere bei inoperablen Gehirntumoren). Das so erzeugte Licht könnte eine photochemische Freisetzung endosomal aufgenommener Wirkstoffe in vitro und in vivo bewirken und sogar eine photodynamische Therapie in schwer zugänglichen Körperregionen ermöglichen. Schließlich könnte vom Tumorgewebe emittiertes Licht der intraoperativen Tumordiagnostik dienen. Die Stoffklasse der 1,2-Dioxetane eignet sich besonders, um Licht mittels Chemolumineszenz im Körper zu erzeugen, weil Licht mit nahezu gleich bleibender, hoher Intensität 30 Minuten lang emittiert wird. Adamantylylidenadamantan-1,2-dioxetan mit einer Sialinsäuregruppe (AMS) emittiert nach der Hydrolyse durch die Neuraminidase bei pH 6 bis 7 Licht einer Wellenlänge von 477 nm. Da das Tumorinterstitium einen leicht sauren pH-Wert aufweist, eignet sich AMS besonders für die Lichterzeugung im Tumor. Ohne enzymatische Hydrolyse kommt die Reaktionskaskade, die der Erzeugung des Lichtes dient nicht in Gang, weil AMS ein spezifisches Substrat der Neuraminidase ist. Zu einem geringen Maß findet im sauren Milieu eine Hydrolyse statt. Mit so genannten Chemolumineszenzenhancern wie Albumin ist es möglich, die Lichtausbeute um das 400fache zu steigern. Damit das Licht vorwiegend im Tumor entsteht, sollte die Zerfallsreaktion des Dioxetans, die zur Emission von Licht führt, hauptsächlich im Tumorgewebe stattfinden. Durch Konjugation der Neuraminidase an Albumin entstünde ein Makromolekül, das dem Enhanced Permeability and Retention Effect unterliegt, so dass es zu einer passiven Anreicherung dieses Konjugates im Tumorinterstitium käme. Außerdem dient Albumin als Chemolumineszenzenhancer. Daher soll zunächst ein Albumin-Neuraminidase-Konjugat hergestellt werden. Zuerst würde man das Albumin-Neuraminidase-Konjugat verabreichen und warten, bis es sich im Tumor angereichert hat. Nachfolgend sollte Adamantylylidenadamantan-1,2-dioxetan mit einer Sialinestergruppe systemisch appliziert werden. Das Zusammentreffen von AMS und der Neuraminidase im Tumor führt zur Lichterzeugung. Ziel ist es, nachzuweisen, dass auch in vivo eine Lichtmenge entsteht im Tumor entsteht, die für eine endosomale Wirkstofffreisetztung, photodynamische Therapie und auch für diagnostische Zwecke ausreicht. Die im Tumor entstehende Lichtmenge wird in tumortragenden Tieren, die zuerst das Albumin-Neuraminidase-Konjugat und zeitversetzt AMS bekommen haben, mittels charge coupled device (CCD) Kamera untersucht. Tumortragende Tiere sollen einer photodynamischen Therapie unterzogen werden, wobei intratumorales Licht als Lichtquelle dienen soll. Das Tumorwachstum soll verglichen werden mit einer unbehandelten Kontrollgruppe sowie einer Gruppe, die mit externem Licht bestrahlt wird. Schließlich soll geprüft werden, ob die Freisetzung eines intralysosomal getrappten Arzneistoffes aus den Lysosomen mittels eines Photosensibilisators und im Tumor erzeugtem Licht möglich ist
A new strategy for the treatment of viral infections
Intact viruses, containing no viral genome but which are loaded with a therapeutic drug or virus like particles loaded with antiviral drugs are potentially selective drug carriers for the intracellular delivery of therapeutics. These virus constructs could be used as therapeutics for the therapy of viral infections. For example HI-viruses could be designed, that are loaded with antisense oligonucleotides that avoid replication of the wild type HI virus. The advantage of such antisense oligonucleotide loaded viruses could be the fact that they enter cells and deliver the therapeutics to the host cells of the wild type HI virus. It should be possible to treat all viral infections with this method. Wild type viruses are therapied by a modified virus of the same type or a virus like particle containing a antiviral drug – e.g. an antisense oligonucleotide. This method should work for all viruses. Additionally, a new method is described how intact viruses, containing no viral genome but which are loaded with a therapeutic drug could be obtained. The major obstacle is that the viral genome and viral proteins must be present for virus assembly on the one hand, on the other hand it must be removed subsequent to virus assembly in order to obtain a safe drug carrier. The idea is: Virus assembly takes place in the presence of the viral genome with subsequent removal of the viral genome. Firstly the viral genome is immobilized on a solid support – comparable to DNA chips. Virus assembly proceeds at the solid support. After virus assembly and drug loading the immobilized viral genome is removed. Viral proteins could be obtained from a packaging cell line. The lysate of such a packaging cell line containing the viral proteins is incubated with the immobilized viral genome to allow virus assembly. The lysate is removed after succesful assembly. The next step would be the loading of the virus with a therapeutic drug. As the viral proteins contain amino and carboxy groups they can be chemically modified by a therapeutic drug. Finally the drug loaded virus is removed from the solid support and with it from the viral genome. This could be a strategy to obtain drug loaded, intact viruses lacking the viral genome
Synthesis and biological evaluation of tumor targetedlysosomotropic detergents
Conjugation of a lysosomotropic detergent to tumor affine peptides (octreotate and melanocortin analogous) resulted in receptor mediated uptake of the peptide conjugates into tumor cells expressing the peptide receptors. During intracellular trafficking the lysosomotropic detergent was cleaved from the peptide. Cytotoxicity studies showed IC50 values in the range of 11-72 µM caused by lysosomal rupture as proven by confocal laser scanning microscopy. For cells not expressing the receptors the conjugates were less cytotoxic
Synthesis, characterization and quantum-chemical analysis of {FeNO}7 and {Fe(NO)2}9 compounds
Ten Years of German Unification
The author discusses the fate of the Foreign Intelligence Department of the GDR, which he headed for over thirty years, and of its colleagues and agents since the reunification of Germany ten years ago. There was no transformation of this service after the implosion of socialism; instead, it was liquidated, and criminal prosecutions followed which continue to this day. The author describes how this is connected to the West German leadership goal of the "de-legitimization" of the GDR. The operations of the western services are described, as well as the actions of their collaborators, who agree to make available, for a price, their knowledge of sources, files, data and other evidence in order for criminal prosecutions to be launched; i.e. the "Rosewood" operation of the CIA, and the decoding of the data carrier "SIRA" and its significance are discussed. The author holds the view that the criminal prosecution of the colleagues and agents of his service violates the internationally recognized legal concept of "equality before the law". Of the approximately 150,000 political indictments initiated since the reunification, 7,099 were for espionage. The article also addresses other subjects, such as the inhumanely high prison sentences in the United States. The author feels that, after ten years, a political gesture should be made which would remove the last vestiges of the Cold War
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