295 research outputs found
Kommt und staunt! Denkmalschutz und IdentitÀtsstiftung an Monumentalbauten in Usbekistan
Usbekistan gehört ohne Frage zu den islamischen KunstlĂ€ndern ersten Ranges, was sich nicht zuletzt in der Aufnahme von StĂ€dten wie Samarkand, Buchara, Chiwa und anderen in die Liste des UNESCO-Welt- kulturerbes Ă€uĂert. Viele der historischen Monumentalbauten Usbekistans sind jedoch in den vergangenen Jahrzehnten, auch schon vor der Erlangung der politischen UnabhĂ€ngigkeit im Jahr 1991, durch RestaurierungsmaĂnahmen mehr oder weniger stark ĂŒberformt worden. Verlorene GebĂ€udestrukturen und Architekturdekore erstanden neu. Selbst fĂŒr Fachleute ist es gegenwĂ€rtig schwer, originales Bauzeitliches von Neuerschaffenem zu unterscheiden. All das lĂ€uft den hehren Theorien der europĂ€ischen Denkmalpflege zuwider, die das Konservieren, also das Erhalten des gealterten Originals, sehen möchte. Der folgende Artikel zeichnet am Beispiel Samarkands, wo die entscheidenden Theorien und Methoden entwickelt wurden, die wichtigsten Meilensteine auf dem Weg zur aktuellen Denkmalpflegepraxis nach und beleuchtet Auswirkungen gesellschafts- und kulturgeschichtlicher Entwicklungen auf die Methoden und Herangehensweisen des Denkmalschutzes. Ziel dabei ist es, zu verstehen, zu erklĂ€ren und zu begrĂŒnden, aber nicht zu richten. Denkmalpflege ist und bleibt weitgehend hoheitliche Aufgabe und steht immer in einem regionalen geschichtlichen Kontex
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Development of an online-coupled MARGA upgrade for the 2âh interval quantification of low-molecular-weight organic acids in the gas and particle phases
A method is presented to quantify the lowmolecular- weight organic acids such as formic, acetic, propionic, butyric, pyruvic, glycolic, oxalic, malonic, succinic, malic, glutaric, and methanesulfonic acid in the atmospheric gas and particle phases, based on a combination of the Monitor for AeRosols and Gases in ambient Air (MARGA) and an additional ion chromatography (Compact IC) instrument. Therefore, every second hourly integrated MARGA gas and particle samples were collected and analyzed by the Compact IC, resulting in 12 values per day for each phase. A proper separation of the organic target acids was initially tackled by a laboratory IC optimization study, testing different separation columns, eluent compositions and eluent flow rates for both isocratic and gradient elution. Satisfactory resolution of all compounds was achieved using a gradient system with two coupled anion-exchange separation columns. Online pre-concentration with an enrichment factor of approximately 400 was achieved by solid-phase extraction consisting of a methacrylate-polymer-based sorbent with quaternary ammonium groups. The limits of detection of the method range between 0.5 ngm3 for malonate and 17.4 ngm3 for glutarate. Precisions are below 1.0 %, except for glycolate (2.9 %) and succinate (1.0 %). Comparisons of inorganic anions measured at the TROPOS research site in Melpitz, Germany, by the original MARGA and the additional Compact IC are in agreement with each other (R2 D0.95-0.99). Organic acid concentrations from May 2017 as an example period are presented. Monocarboxylic acids were dominant in the gas phase with mean concentrations of 306 ngm3 for acetic acid, followed by formic (199 ngm3), propionic (83 ngm3), pyruvic (76 ngm3), butyric (34 ngm3) and glycolic acid (32 ngm3). Particulate glycolate, oxalate and methanesulfonate were quantified with mean concentrations of 26, 31 and 30 ngm3, respectively. Elevated concentrations of gas-phase formic acid and particulate oxalate in the late afternoon indicate photochemical formation as a source
Cerebrovascular reactivity during the Valsalva maneuver in migraine, tension-type headache and medication overuse headache
The aim of this study was to investigate, by means of
transcranial Doppler ultrasound (TCD), cerebrovascular
reactivity during the Valsalva maneuver (VM) during
the headache-free interval in patients with migraine (M),
migraine plus tension-type headache (M+TTH), and migraine
plus medication overuse headache (M+MOH). A total of 114 patients (n=60 M, n=38 M+TTH, n=16 M+MOH) and n=60 controls were investigated; diagnoses were made according to the International Headache Society criteria. All subjects underwent TCD monitoring and, simultaneously, non-invasive assessment of arterial blood pressure and end-tidal CO2. Two
indices were determined: the cerebrovascular Valsalva
ratio (CVR) was calculated as the maximum end-diastolic
flow velocity acceleration during the late straining
phase of the VM [cm/s2] and the centroperipheral Valsalva
ratio (CPVR) was defined as the quotient of CVR
to the concomitant arterial blood pressure acceleration
[cm/mmHg x s].
The dynamic cerebrovascular autoregulatory response
to the VM, measured as CVR, was increased in patients
with M and M+TTH compared to age-matched healthy
subjects. By contrast, CPVR (i.e. the quotient of the
cerebrovascular to the peripheral autonomic response),
was increased in M patients compared to
healthy subjects and all other headache conditions
tested.
Cerebrovascular autoregulatory response during the
VM was increased in M patients compared to agematched
normal healthy subjects, indicating a disturbed
autonomic control of cerebral vasoreactivity.
The CPVR seems to be a sensitive parameter for distinguishing between M patients and M+TTH or M+MOH patients
Measurements of PM10 ions and trace gases with the online system MARGA at the research station Melpitz in Germany â A five-year study
An hourly quantification of inorganic water-soluble PM10 ions and corresponding trace gases was performed using the Monitor for AeRosols and Gases in ambient Air (MARGA) at the TROPOS research site in Melpitz, Germany. The data availability amounts to over 80% for the five-year measurement period from 2010 to 2014. Comparisons were performed for the evaluation of the MARGA, resulting in coefficients of determinations (slopes) of 0.91 (0.90) for the measurements against the SO2 gas monitor, 0.84 (0.88), 0.79 (1.39), 0.85 (1.20) for the ACSM NO3 â, SO4 2â and NH4 + measurements, respectively, and 0.85 (0.65), 0.88 (0.68), 0.91 (0.83), 0.86 (0.82) for the filter measurements of Clâ, NO3 â, SO4 2â and NH4 +, respectively. A HONO comparison with a batch denuder shows large scatter (R2 = 0.41). The MARGA HNO3 is underestimated compared to a batch and coated denuder with shorter inlets (slopes of 0.16 and 0.08, respectively). Less NH3 was observed in coated denuders for high ambient concentrations. Long-time measurements show clear daily and seasonal variabilities. Potential Source Contribution Function (PSCF) analysis indicates the emission area of particulate ions Clâ, NO3 â, SO4 2â, NH4 +, K+ and gaseous SO2 to lie in eastern European countries, predominantly in wintertime. Coarse mode sea salt particles are transported from the North Sea to Melpitz. The particles at Melpitz are nearly neutralised with a mean molar ratio of 0.90 for the five-year study. A slight increase of the neutralization ratio over the last three years indicates a stronger decrease of the anthropogenically emitted NO3 â and SO4 2â compared to NH4 +
Pharmacokinetics, absorption, distribution, metabolism and excretion of the MEK inhibitor zapnometinib in rats
Zapnometinib is a MEK inhibitor currently under clinical development for the treatment of COVID-19 and influenza. Zapnometinib has both antiviral and immunomodulatory effects. Information concerning the absorption, distribution, metabolism, and excretion of the compound following single oral doses of 30Â mg/kg [14C]-zapnometinib to rats was required to support pharmacology and toxicology studies in animals and clinical studies in man. As part of the development and safety assessment of this substance, zapnometinib was radioactively labeled and used for the investigation of time-dependent plasma concentrations, the rates and routes of excretion, the extent and time-course of compound distribution in body tissues, the metabolite profiles in plasma, urine and feces and the chemical nature of its metabolites. The present study reveals a rapid but low absorption of zapnometinib from the gastrointestinal tract, with more than 90% of the compound being excreted within 48Â h, mainly via feces. Whole body autoradiography confirms that zapnometinib was rapidly and widely distributed, with greatest concentrations in the circulatory and visceral tissues. Maximum plasma and tissue concentrations occurred between two and 8Â h post dose. Penetration into the brain was low, and elimination from most tissues almost complete after 168Â h. Metabolic profiles showed that the main clearance routes were metabolism via oxidative reactions and glucuronidation. These results further strengthen the knowledge of zapnometinib with respect to the clinical development of the drug
Entwicklung eines zwanglĂ€ufigen Schneid- und Fixiersystems fĂŒr den Einsatz in einem Tapelegekopf
Im Rahmen des Bundesxzellenzclusters MERGE EXC 1075 an der TU Chemnitz erfolgte die Entwicklung einer neuartigen groĂserientauglichen Technologie zur Herstellung faserverstĂ€rkter Thermoplastbauteile. FĂŒr die Demonstration der Technologie wurde eine Pilotanlage realisiert, die zum Ablegen des Thermoplasttapes ĂŒber eine Verlegeeinheit â einen sog. Tapelegekopf â verfĂŒgt. Mit Abschluss des Legeprozesses wird das Halbzeug, das aus einer angebremsten Spule abgezogen wird, abgeschnitten und der Prozess wird von neuem begonnen.
FĂŒr das Schneiden des Materials haben Voruntersuchungen gezeigt, dass konturierte Klingen erforderlich sind, um ein Verlaufen des Bandes zu vermeiden. DarĂŒber hinaus hat sich als zweckmĂ€Ăig erwiesen eine zusĂ€tzliche Fixierung vorzunehmen. Dies verbessert die SchnittqualitĂ€t und ZuverlĂ€ssigkeit des Systems.
Aufgrund enger Bauraumrestriktionen wurde entschieden die Schneidbewegung und das Fixieren zwanglĂ€ufig synchronisiert auf einen Antrieb zurĂŒck zu fĂŒhren. HierfĂŒr wurden zwei ungleichmĂ€Ăige Rastgetriebe synthetisiert, ausgelegt sowie in weiteren Entwicklungsstufen auskonstruiert, gefertigt und getestet.
Mit der Inbetriebnahme des Gesamtanlagensystems erfolgte ebenfalls der Funktionsnachweis dieses mechanisch zwanglÀufigen Schneidsystems, das im Rahmen des Vortrags vorgestellt wird.
Diese Arbeiten entstanden im Rahmen des Bundesexzellenzclusters EXC 1075 âTechnologiefusion fĂŒr multifunktionale Leichtbaustrukturenâ und wurde von der Deutschen Forschungsgemeinschaft gefördert. Die Autoren danken fĂŒr die finanzielle UnterstĂŒtzung
Development of an online-coupled MARGA upgrade for the 2 h interval quantification of low-molecular-weight organic acids in the gas and particle phases
A method is presented to quantify the low-molecular-weight organic acids such
as
formic, acetic, propionic, butyric, pyruvic, glycolic, oxalic,
malonic, succinic, malic, glutaric, and methanesulfonic acid in the
atmospheric gas and particle phases, based on a combination of the Monitor for
AeRosols and Gases in ambient Air (MARGA) and an additional ion
chromatography (Compact IC) instrument. Therefore, every second hourly
integrated MARGA gas and particle samples were collected and analyzed by the
Compact IC, resulting in 12 values per day for each phase. A proper separation
of the organic target acids was initially tackled by a laboratory IC
optimization study, testing different separation columns, eluent compositions
and eluent flow rates for both isocratic and gradient elution. Satisfactory
resolution of all compounds was achieved using a gradient system with two
coupled anion-exchange separation columns. Online pre-concentration with an
enrichment factor of approximately 400 was achieved by solid-phase extraction
consisting of a methacrylate-polymer-based sorbent with quaternary ammonium
groups. The limits of detection of the method range between 0.5 ng mâ3
for malonate and 17.4 ng mâ3 for glutarate. Precisions are below
1.0 %, except for glycolate (2.9 %) and succinate (1.0 %).
Comparisons of inorganic anions measured at the TROPOS research site in
Melpitz, Germany, by the original MARGA and the additional Compact IC are in
agreement with each other (R2 = 0.95â0.99). Organic acid concentrations
from May 2017 as an example period are presented. Monocarboxylic acids were
dominant in the gas phase with mean concentrations of 306 ng mâ3 for
acetic acid, followed by formic (199 ng mâ3), propionic
(83 ng mâ3), pyruvic (76 ng mâ3), butyric (34 ng mâ3)
and glycolic acid (32 ng mâ3). Particulate glycolate, oxalate and
methanesulfonate were quantified with mean concentrations of 26, 31 and
30 ng mâ3, respectively. Elevated concentrations
of gas-phase formic acid and particulate oxalate in the late afternoon indicate photochemical
formation as a source.</p
Integrated North Sea grids: The costs, the benefits and their distribution between countries
A large number of offshore wind farms and interconnectors are expected to be constructed in the North Sea region over the coming decades, creating substantial opportunities for the deployment of integrated network solutions. Creating interconnected offshore grids that combine cross-border links and connections of offshore plants to shore offers multiple economic and environmental advantages for Europe's energy system. However, despite evidence that integrated solutions can be more beneficial than traditional radial connection practices, no such projects have been deployed yet. In this paper we quantify costs and benefits of integrated projects and investigate to which extent the cost-benefit sharing mechanism between participating countries can impede or encourage the development of integrated projects. Three concrete interconnection case studies in the North Sea area are analysed in detail using a national-level power system model. Model outputs are used to compute the net benefit of all involved stakeholders under different allocation schemes. Given the asymmetric distribution of costs and benefits, we recommend to consistently apply the Positive Net Benefit Differential mechanism as a starting point for negotiations on the financial closure of investments in integrated offshore infrastructure
Efficacy of frovatriptan versus other triptans in the acute treatment of menstrual migraine: pooled analysis of three double-blind, randomized, crossover, multicenter studies
The objective of this study was to review the efficacy and safety of frovatriptan (F) versus rizatriptan (R), zolmitriptan (Z) and almotriptan (A), in women with menstrually related migraine (IHS criteria) through a pooled analysis of three individual studies. Subjects with a history of migraine with or without aura were randomized to F 2.5Â mg or R 10Â mg (study 1), F or Z 2.5Â mg (study 2), and F or A 12.5Â mg (study 3). The studies had an identical multicenter, randomized, double-blind, crossover design. After treating three episodes of migraine in no more than 3Â months with the first treatment, patients had to switch to the next treatment for other 3Â months. 346 subjects formed intention-to-treat population of the main study; 280 of them were of a female gender, 256 had regular menses and 187 were included in the menstrual migraine subgroup analysis. Rate of pain free at 2, 4 and 24Â h was 23, 52 and 67Â % with F and 30, 61 and 66Â % with comparators (PÂ =Â NS). Pain relief episodes at 2, 4 and 24Â h were 37, 60 and 66Â % for F and 43, 55 and 61Â % for comparators (PÂ =Â NS). Rate of recurrence was significantly (PÂ <Â 0.05) lower under F either at 24Â h (11 vs. 24Â % comparators) or at 48Â h (15 vs. 26Â % comparators). Number of menstrual migraine attacks associated with drug-related adverse events was equally low (PÂ =Â NS) between F (5Â %) and comparators (4Â %)
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