31 research outputs found
DotTrack: absolute und relative Ortsbestimmung von Tangibles mittels eines Maussensors
Tangible User Interfaces (TUIs) integrieren oft physische Objekte, deren Positionierung oder Positionsveränderung durch den Nutzer zur Interaktion verwendet wird. DotTrack ist ein Tracking-Verfahren, das absolute Ortsbestimmung und Tracking der Position von Tangibles ohne externe Infrastruktur erlaubt. Der Prototyp verwendet dazu einen kommerziellen Maussensor, der nicht nur die Translation misst, sondern auch ein Kamerabild des Untergrunds liefert. Ein eindeutiges Punktmuster auf dem Untergrund erlaubt es, die absolute Position des Prototypen zu bestimmen. Im momentanen Entwicklungsstand sind rudimentäre absolute Ortsbestimmung, Positionstracking und mehrere Anwendungsbeispiele für das System implementiert
Stereochemistry of phase-1 metabolites of mephedrone determines their effectiveness as releasers at the serotonin transporter
Mephedrone (4-methyl-N-methylcathinone) is a psychostimulant that promotes release of monoamines via the high affinity transporters for dopamine (DAT), norepinephrine (NET) and serotonin (SERT). Metabolic breakdown of mephedrone results in bioactive metabolites that act as substrate-type releasers at monoamine transporters and stereospecific metabolism of mephedrone has been reported. This study compared the effects of the enantiomers of the phase-1 metabolites nor-mephedrone, 4-hydroxytolyl-mephedrone (4-OH-mephedrone) and dihydro-mephedrone on (i) DAT, NET and SERT mediated substrate fluxes, (ii) determined their binding affinities towards a battery of monoamine receptors and (iii) examined the relative abundance of the enantiomers in human urine. Each of the enantiomers tested inhibited uptake mediated by DAT, NET and SERT. No marked differences were detected at DAT and NET. However, at SERT, the S-enantiomers of nor-mephedrone and 4-OH-mephedrone were several times more potent than the corresponding R-enantiomers. Moreover, the R-enantiomers were markedly less effective as releasers at SERT. S-nor-mephedrone displayed moderate affinities towards human alpha; 1A; , human 5-HT; 2A; and rat and mouse trace amine-associated receptor 1. These results demonstrate that stereochemistry dictates the pharmacodynamics of the phase-1 metabolites of mephedrone at SERT, but not at DAT and NET, which manifests in marked differences in their relative potencies, i.e. DAT/SERT ratios. Chiral analysis of urine samples demonstrated that nor-mephedrone predominantly exists as the S-enantiomer. Given the asymmetric abundance of the enantiomers in biological samples, these findings may add to our understanding of the subjective effects of administered mephedrone, which indicate pronounced effects on the serotonergic system
Primary biliary cirrhosis
Primary biliary cirrhosis (PBC) is an immune-mediated chronic cholestatic liver disease with a slowly progressive course. Without treatment, most patients eventually develop fibrosis and cirrhosis of the liver and may need liver transplantation in the late stage of disease. PBC primarily affects women (female preponderance 9–10:1) with a prevalence of up to 1 in 1,000 women over 40 years of age. Common symptoms of the disease are fatigue and pruritus, but most patients are asymptomatic at first presentation. The diagnosis is based on sustained elevation of serum markers of cholestasis, i.e., alkaline phosphatase and gamma-glutamyl transferase, and the presence of serum antimitochondrial antibodies directed against the E2 subunit of the pyruvate dehydrogenase complex. Histologically, PBC is characterized by florid bile duct lesions with damage to biliary epithelial cells, an often dense portal inflammatory infiltrate and progressive loss of small intrahepatic bile ducts. Although the insight into pathogenetic aspects of PBC has grown enormously during the recent decade and numerous genetic, environmental, and infectious factors have been disclosed which may contribute to the development of PBC, the precise pathogenesis remains enigmatic. Ursodeoxycholic acid (UDCA) is currently the only FDA-approved medical treatment for PBC. When administered at adequate doses of 13–15 mg/kg/day, up to two out of three patients with PBC may have a normal life expectancy without additional therapeutic measures. The mode of action of UDCA is still under discussion, but stimulation of impaired hepatocellular and cholangiocellular secretion, detoxification of bile, and antiapoptotic effects may represent key mechanisms. One out of three patients does not adequately respond to UDCA therapy and may need additional medical therapy and/or liver transplantation. This review summarizes current knowledge on the clinical, diagnostic, pathogenetic, and therapeutic aspects of PBC
Spatially-Aware Tangibles Using Mouse Sensors
We demonstrate a simple technique that allows tangible objects to track their own position on a surface using an off-the-shelf optical mouse sensor. In addition to measuring the (relative) movement of the device, the sensor also allows capturing a low-resolution raw image of the surface. This makes it possible to detect the absolute position of the device via marker patterns at known positions. Knowing the absolute position may either be used to trigger actions or as a known reference point for tracking the device. This demo allows users to explore and evaluate affordances and applications of such tangibles
Water-promoted chlorination of 2-mercaptobenzothiazoles
Substituted benzothiazoles play an important role in medicinal
chemistry due to their pharmacological properties. Their 2-substituted
derivatives are often prepared from 2-chlorobenzothiazoles, which in turn can
be made from the 2-mercapto precursor using sulfuryl chloride. In practice,
this seemingly straightforward, and widely used reaction can be impeded by
poor reproducibility and reaction yields. In this communication we report the
importance of acid as catalyst for the parent reaction. The addition of water to
the reaction mixture represents a facile and practical method for generating
acid in situ. This simple solution reproducibly ensured excellent yields of a
variety of chlorinated products
GABAA receptor activity modulating piperine analogs: In vitro metabolic stability, metabolite identification, CYP450 reaction phenotyping, and protein binding.
In a screening of natural products for allosteric modulators of GABAA receptors (γ-aminobutyric acid type A receptor), piperine was identified as a compound targeting a benzodiazepine-independent binding site. Given that piperine is also an activator of TRPV1 (transient receptor potential vanilloid type 1) receptors involved in pain signaling and thermoregulation, a series of piperine analogs were prepared in several cycles of structural optimization, with the aim of separating GABAA and TRPV1 activating properties. We here investigated the metabolism of piperine and selected analogs in view of further cycles of lead optimization. Metabolic stability of the compounds was evaluated by incubation with pooled human liver microsomes, and metabolites were analyzed by UHPLC-Q-TOF-MS. CYP450 isoenzymes involved in metabolism of compounds were identified by reaction phenotyping with Silensomes™. Unbound fraction in whole blood was determined by rapid equilibrium dialysis. Piperine was the metabolically most stable compound. Aliphatic hydroxylation, and N- and O-dealkylation were the major routes of oxidative metabolism. Piperine was exclusively metabolized by CYP1A2, whereas CYP2C9 contributed significantly in the oxidative metabolism of all analogs. Extensive binding to blood constituents was observed for all compounds
Redox-Active Esters in Fe-Catalyzed C–C Coupling
Cross-couplings
of alkyl halides and organometallic species based
on single electron transfer using Ni and Fe catalyst systems have
been studied extensively, and separately, for decades. Here we demonstrate
the first couplings of redox-active esters (both isolated and derived <i>in situ</i> from carboxylic acids) with organozinc and organomagnesium
species using an Fe-based catalyst system originally developed for
alkyl halides. This work is placed in context by showing a direct
comparison with a Ni catalyst for >40 examples spanning a range
of
primary, secondary, and tertiary substrates. This new C–C coupling
is scalable and sustainable, and it exhibits a number of clear advantages
in several cases over its Ni-based counterpart
Cellular N-myristoyltransferases play a crucial picornavirus genus-specific role in viral assembly, virion maturation, and infectivity.
In nearly all picornaviruses the precursor of the smallest capsid protein VP4 undergoes co-translational N-terminal myristoylation by host cell N-myristoyltransferases (NMTs). Curtailing this modification by mutation of the myristoylation signal in poliovirus has been shown to result in severe assembly defects and very little, if any, progeny virus production. Avoiding possible pleiotropic effects of such mutations, we here used pharmacological abrogation of myristoylation with the NMT inhibitor DDD85646, a pyrazole sulfonamide originally developed against trypanosomal NMT. Infection of HeLa cells with coxsackievirus B3 in the presence of this drug decreased VP0 acylation at least 100-fold, resulting in a defect both early and late in virus morphogenesis, which diminishes the yield of viral progeny by about 90%. Virus particles still produced consisted mainly of provirions containing RNA and uncleaved VP0 and, to a substantially lesser extent, of mature virions with cleaved VP0. This indicates an important role of myristoylation in the viral maturation cleavage. By electron microscopy, these RNA-filled particles were indistinguishable from virus produced under control conditions. Nevertheless, their specific infectivity decreased by about five hundred fold. Since host cell-attachment was not markedly impaired, their defect must lie in the inability to transfer their genomic RNA into the cytosol, likely at the level of endosomal pore formation. Strikingly, neither parechoviruses nor kobuviruses are affected by DDD85646, which appears to correlate with their native capsid containing only unprocessed VP0. Individual knockout of the genes encoding the two human NMT isozymes in haploid HAP1 cells further demonstrated the pivotal role for HsNMT1, with little contribution by HsNMT2, in the virus replication cycle. Our results also indicate that inhibition of NMT can possibly be exploited for controlling the infection by a wide spectrum of picornaviruses