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Unaltered pancreatic islet blood perfusion in islet amyloid polypeptide-deficient mice

Objective: Several biological activities have been ascribed to islet amyloid polypeptide (IAPP). However, their physiological relevance remains unclear. Previous studies in rats with exogenous administration of IAPP suggest that the peptide may increase splanchnic vascular resistance and redistribute the blood flow within the pancreas to the islets. In this study, the use of IAPP-deficient mice al

Will sympatric speciation fail due to stochastic competitive exclusion?

Sympatric speciation requires coexistence of the newly formed species. If divergence proceeds by small mutational steps, the new species utilize almost the same resources initially, and full speciation may be impeded by competitive exclusion in stochastic environments. We investigate this primarily ecological problem of sympatric speciation by studying the population dynamics of a diverging asexua

Purification of histidine-tagged single-chain Fv-antibody fragments by metal chelate affinity precipitation using thermoresponsive copolymers

Metal chelate affinity precipitation (MCAP) has been successfully developed as a simple purification process for proteins that have affinity for metal ions. The present lack of widespread applications for this technique as compared to immobilized metal affinity chromatography (IMAC) may be related to the scarcity of well-characterized metal affinity macroligands (AML) and their applications to the

Path dependency and the future of advanced vehicles and biofuels

The accumulated experience and path-dependent development of petroleum-based transport fuels and internal combustion engine vehicles has created an apparent technological lock-in. Our analysis of a RApid Future vehicles and Fuels scenario (RAFF) for the EU shows that ambitious carbon emission reductions can be achieved even with projected increases in road transport. Furthermore, escaping the lock

Anti-inflammatory properties of micropatterned titanium coatings

Prolonged inflammation and reactive oxygen species (ROS) generated around an implanted biosensor are the primary causes of the foreign body response, including encapsulation of biosensor membranes. We have previously demonstrated that TiO2 surfaces reduce ROS. Here we investigated the potential of using the anti-inflammatory properties of TiO2 in the design of biosensor membranes with improved lon

Experimental quantum-state tomography of a solid-state qubit

Quantum-state tomography is used to characterize the state of an ensemble based qubit implemented through two hyperfine levels in Pr3+ ions, doped into a Y2SiO5 crystal. We experimentally verify that single-qubit rotation errors due to inhomogeneities of the ensemble can be suppressed using the Roos-Molmer dark-state scheme [Roos and Molmer, Phys. Rev. A 69, 022321 (2004)] Fidelities above > 90%,

Structure elucidation of the hepatitis B virus encapsidation signal by NMR on selectively labeled RNAs.

Hepatitis B virus (HBV) HBV is DNA virus with a unique replication strategy, which involves reverse transcription of its pregenomic RNA. Essential for this reverse transcription are the 5'- and 3'-ends of its pregenomic RNA (5'-RT-RNA and 3'-RT-RNA, respectively) which form conserved bulged stem-loop structures. The 5'-RT-RNA consists of a 67 nucleotide bulged stein-loop structure, epsilon, which

Multifocal electroretinography (mfERG) in insulin dependent diabetics with and without clinically apparent retinopathy

Purpose: To Study the retinal function, using multifocal electroretinography (mfERG), in diabetic patients with mild and moderate retinopathy, and in diabetics without clinically apparent retinopathy. Methods: Thirty-one patients with insulin dependent diabetes mellitus, eleven without any clinically apparent retinopathy, twelve with mild retinopathy and eight with moderate retinopathy, were studi

HIV/hepatitis coinfection in eastern Europe and new pan-European approaches to hepatitis prevention and management

Issues: HIV/hepatitis coinfection in Europe; WHO European clinical protocols on the management of people coinfected with HIV/AIDS and hepatitis B or C (HBV or HCV); stakeholder recommendations for better HCV services. Introduction: The increasing availability of highly active antiretroviral therapy throughout Europe and central Asia has changed comorbidity and mortality patterns among people livin

Enzymatic and chemical synthesis of phosphatidylcholine regioisomers containing eicosapentaenoic acid or docosahexaenoic acid

Regioselective incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into phosphatidylcholine (PC) was carried out using enzymatic and chemical synthesis. Incorporation at the sn-1 position was successfully achieved by lipase-catalysed esterification of 2-palmitoyl-lysophosphatidylcholine (LPC), although in most cases, the enzymes incorporated EPA and DHA at lower rates than

Female call preferences in tree-hole frogs: why are there so many unattractive males?

In tree-hole frogs, Metaphrynella sundana, the fundamental call frequency varies widely between males. In field playback experiments, females strongly preferred calls from the lower range of frequencies found in the population. There was no correlation, however, between male size and call frequency, as is normally the case for anurans, so large males were not necessarily more attractive to females

Extraction of cadmium from phosphoric acid solutions with amines. Part III. A thermodynamic extraction model

A thermodynamic model for cadmium extraction from phosphoric-hydrochloric acid mixtures has been developed. The model enables calculations of cadmium extraction as well as coextraction of phosphoric and hydrochloric acids to be made. In the aqueous phase Bromley's model for the activity coefficients is adopted. In the organic phase simple expressions for the non-ideal behaviour of phosphoric acid

Extending the Light-Harvesting Properties of Transition-Metal Dendrimers

We report a study of the electronic energy-transfer dynamics within the transition-metal polypyridine complex OsRu3pyr6 (Os[(dpp)Ru(bpy{pyrene})2]38+, where dpp=2,3-bis(2-pyridyl)pyrazine and bpy=2,2-bipyridine) after excitation with UV light. By using a broadband visible femtosecond probe, we are able to simultaneously detect both the energy transfer from the peripheral aromatic ligands to the Os

Magnetic resonance imaging of the knee in chronic knee pain. A 2-year follow-up

Objective: The aim of the study was to evaluate the change over time of cartilage defects, subchondral lesions and meniscal abnormalities of the knee using magnetic resonance (MR) imaging with a 2-year interval in patients with chronic knee pain. Design: In the format of a prospective study of early osteoarthritis (OA), the signal knee (most painful at the inclusion in the study 1990) in 47 indivi