A new look at an old classic: implementation of a SERS-based water hardness titration.

The routine use of SERS as an analytical technique has been hindered by practical considerations among which the irreproducibility of its signals and the lack of robustness of its calibration. In the present work, we examine a strategy to perform quantitative SERS without the need for calibration. The method reinvests a colorimetric volumetric titration procedure to determine water hardness but involves monitoring the progression of the titration through the SERS signal of a complexometric indicator.

Influence of pedestal diameter on mode instabilities in Yb/Ce/Al-doped fibers.

In this paper we present numerical and experimental results revealing that the mode instability threshold of highly Yb-doped, Ce/Al co-doped pedestal fibers is affected by the size of the index-increased pedestal structure surrounding the core. An alternative preparation technology for the realization of large mode area fibers with very large Al-doped silica pedestals is introduced. Three different pedestal fiber design iterations characterized by low photodarkening were manufactured and tested in counter-pumped amplifier setups.

Magnetite-Arginine Nanoparticles as a Multifunctional Biomedical Tool.

Iron oxide nanoparticles are a promising platform for biomedical applications, both in terms of diagnostics and therapeutics. In addition, arginine-rich polypeptides are known to penetrate across cell membranes. Here, we thus introduce a system based on magnetite nanoparticles and the polypeptide poly-l-arginine (polyR-FeO).

A frugal implementation of Surface Enhanced Raman Scattering for sensing Zn in freshwaters - In depth investigation of the analytical performances.

Surface Enhanced Raman Scattering (SERS) has been widely praised for its extreme sensitivity but has not so far been put to use in routine analytical applications, with the accessible scale of measurements a limiting factor. We report here on a frugal implementation of SERS dedicated to the quantitative detection of Zn in water, Zn being an element that can serve as an indicator of contamination by heavy metals in aquatic bodies. The method consists in randomly aggregating simple silver colloids in the analyte solution in the presence of a complexometric indicator of Zn, recording the SERS spectrum with a portable Raman spectrometer and analysing the data using multivariate calibration models.

Reducing Conditions Favor Magnetosome Production in AMB-1.

Magnetotactic bacteria (MTB) are a heterogeneous group of Gram-negative prokaryotes, which all produce special magnetic organelles called magnetosomes. The magnetosome consists of a magnetic nanoparticle, either magnetite (FeO) or greigite (FeS), embedded in a membrane, which renders the systems colloidaly stable, a desirable property for biotechnological applications. Although these bacteria are able to regulate the formation of magnetosomes through a biologically-controlled mechanism, the environment in general and the physico-chemical conditions surrounding the cells in particular also influence biomineralization.

Overlapping but distinct topology for zebrafish V2R-like olfactory receptors reminiscent of odorant receptor spatial expression zones.

Background: The sense of smell is unrivaled in terms of molecular complexity of its input channels. Even zebrafish, a model vertebrate system in many research fields including olfaction, possesses several hundred different olfactory receptor genes, organized in four different gene families. For one of these families, the initially discovered odorant receptors proper, segregation of expression into distinct spatial subdomains within a common sensory surface has been observed both in teleost fish and in mammals.

The importance of the helical structure of a MamC-derived magnetite-interacting peptide for its function in magnetite formation.

Biomineralization is the process of mineral formation by organisms and involves the uptake of ions from the environment in order to produce minerals, with the process generally being mediated by proteins. Most proteins that are involved in mineral interactions are predicted to contain disordered regions containing large numbers of negatively charged amino acids. Magnetotactic bacteria, which are used as a model system for iron biomineralization, are Gram-negative bacteria that can navigate through geomagnetic fields using a specific organelle, the magnetosome.

Single crystalline superstructured stable single domain magnetite nanoparticles.

Magnetite nanoparticles exhibit magnetic properties that are size and organization dependent and, for applications that rely on their magnetic state, they usually have to be monodisperse. Forming such particles, however, has remained a challenge. Here, we synthesize 40 nm particles of magnetite in the presence of polyarginine and show that they are composed of 10 nm building blocks, yet diffract like single crystals.

Combined Experimental and Theoretical Approach to the Kinetics of Magnetite Crystal Growth from Primary Particles.

It is now recognized that nucleation and growth of crystals can occur not only by the addition of solvated ions but also by accretion of nanoparticles, in a process called nonclassical crystallization. The theoretical framework of such processes has only started to be described, partly due to the lack of kinetic or thermodynamic data. Here, we study the growth of magnetite nanoparticles from primary particles-nanometer-sized amorphous iron-rich precursors-in aqueous solution at different temperatures.

The opiate dosage adequacy scale for identification of the right methadone dose--a prospective cohort study.

Background: Opioid maintenance treatment with methadone is regarded as gold standard in the therapy of opioid dependence. Identification of the 'right' methadone dose, however, remains challenging. We wanted to explore if the Opiate Dosage Adequacy Scale (ODAS) is a helpful instrument in methadone titration.

Do you want some spiritual support? Different rates of positive response to chaplains' versus nurses' offer.

Access to spiritual support appears to be important in the hospital setting. The offer of spiritual support can be done by different providers such as doctors, nurses or chaplains. Who should initiate or coordinate this spiritual care.

"Glass fairies" and "bone children": adolescents and young adults with anorexia nervosa show positive reactions towards extremely emaciated body pictures measured by the startle reflex paradigm.

In this study, we investigated the emotional processing of extremely emaciated body cues in adolescents and young adults with (n  =  36) and without (n =  36) anorexia nervosa (AN), introducing a new picture type, which was taken from websites that promote extreme thinness and is targeted specifically at adolescents interested in extreme thinness. A startle reflex paradigm was used for implicit reactions, while a self-assessment instrument was used for subjective responses. We found a significant group difference with a startle inhibition (appetitive response) among the patients and a startle potentiation (aversive response) among the controls, whereas no such difference for subjective measures was found.

Design of simultaneous antimicrobial and anticoagulant surfaces based on nanoparticles and polysaccharides.

The rational design of silver nanoparticles encapsulated in an anticoagulant, hemocompatible polysaccharide, 6-O-chitosan sulfate, is presented. Three different approaches are described for the immobilization of these core shell particles on cellulosic surfaces. The mass of the immobilized particles is quantified using a quartz crystal microbalance with dissipation (QCM-D).

Chitosan-silane sol-gel hybrid thin films with controllable layer thickness and morphology.

The preparation of thin films of chitosan-silane hybrid materials by combining sol-gel processing and spin coating is reported. A variety of silanes can be used as starting materials for the preparation of such thin films, namely tetraethoxysilane, tri-tert-butoxysilanol, trimethylethoxysilane, p-trifluoromethyltetra-fluorophenyltriethoxysilane, trivinylmethoxysilane, (methoxymethyl)trimethyl-silane, and hexamethoxydisilane. These silanes are subjected to a sol-gel process before they are added to acidic chitosan solutions.

Female fitness optimum at intermediate mating rates under traumatic mating.

Traumatic mating behaviors often bear signatures of sexual conflict and are then typically considered a male strategy to circumvent female choice mechanisms. In an extravagant mating ritual, the hermaphroditic sea slug Siphopteron quadrispinosum pierces the integument of their mating partners with a syringe-like penile stylet that injects prostate fluids. Traumatic injection is followed by the insertion of a spiny penis into the partner's gonopore to transfer sperm.

The ABC of the blood-brain barrier - regulation of drug efflux pumps.

According to the World Health Organization Central nervous system disorders are the major medical challenge of the 21st Century, yet treatments for many CNS disorders are either inadequate or absent. One reason is the existence of the blood-brain barrier, which strictly limits the access of substances to the brain. A key element of the barrier function is the expression of ABC export proteins in the luminal membrane of brain microvessel endothelial cells.

P-glycoprotein and breast cancer resistance protein expression and function at the blood-brain barrier and blood-cerebrospinal fluid barrier (choroid plexus) in streptozotocin-induced diabetes in rats.

The aim of the study was to investigate the influence of diabetes mellitus type 1 on expression and function of the ATP-binding cassette transport proteins P-glycoprotein (Pgp, Abcb1) and breast cancer resistance protein (Bcrp, Abcg2) at the blood-brain barrier and the blood-cerebrospinal fluid barrier formed by the choroid plexus. In brain capillary endothelial cells forming the blood-brain barrier, Pgp and Bcrp are located in the luminal membrane while apical/sub-apical localization was described for Pgp in choroid plexus epithelial cells. Alterations in expression or function may lead to damages in barrier integrity and may cause brain defects after long term diabetes.

Characterization of immortalized choroid plexus epithelial cell lines for studies of transport processes across the blood-cerebrospinal fluid barrier.

Background: Two rodent choroid plexus (CP) epithelial cell lines, Z310 and TR-CSFB, were compared with primary rat CP epithelial cells and intact CP tissue with respect to transport protein expression, function and tight junction (TJ) formation.

Methods: For expression profiles of transporters and TJ proteins, qPCR and western blot analysis were used. Uptake assays were performed to study the functional activity of transporters and TJ formation was measured by trans-epithelial electrical resistance (TEER) and visualized by electron microscopy.

Fluo-cAMP is transported by multidrug resistance-associated protein isoform 4 in rat choroid plexus.

The choroid plexuses (CP) are responsible for transport of micronutrients into brain and clearance of toxic compounds, in addition to its barrier function and production of CSF. Multidrug resistance-associated protein (Mrp) 4 is one transport protein highly expressed in CP tissue and is characterized as a versatile pump for toxicants and signalling molecules. Aim of the study was to determine transport characteristics of a fluorescent cAMP analog in rat CP and to define whether fluo-cAMP can be used for analyses of function, substrate/inhibitor specificity and regulation of Mrp4.

Development of a fluorescence-based assay for drug interactions with human Multidrug Resistance Related Protein (MRP2; ABCC2) in MDCKII-MRP2 membrane vesicles.

Purpose: To establish a fluorescence-based assay for drug interactions with the ABC-export-protein MRP2 (ABCC2).

Methods: Apical membrane vesicles were isolated by differential centrifugation from polarized MDCKII cells and MDCKII cells transfected with human MRP2. Vesicle fractions were characterized by electron microscopy, determination of the marker enzyme alkaline phosphatase and Western blot analysis of MRP2.

Nonlinear photonic crystal fiber with a structured multi-component glass core for four-wave mixing and supercontinuum generation.

We report about a new type of nonlinear photonic crystal fibers allowing broadband four-wave mixing and supercontinuum generation. The microstructured optical fiber has a structured core consisting of a rod of highly nonlinear glass material inserted in a silica tube. This particular structure enables four wave mixing processes with very large frequency detuning (>135 THz), which permitted the generation of a wide supercontinuum spectrum extending over 1650 nm after 2.

Non-isothermal bleaching of photodarkened Yb-doped fibers.

We report on the thermal treatment of photodarkened Yb-doped fiber samples. The method of non-isothermal bleaching at different temperature ramp rates can be used to determine the thermal energy distribution of photodarkening induced color centers. A distributed activation energy with a mean value of about 1.

Texas Red transport across rat and dogfish shark (Squalus acanthias) choroid plexus.

Confocal microscopy and image analysis were used to compare driving forces, specificity, and regulation of transport of the fluorescent organic anion, Texas Red (sulforhodamine 101 free acid; TR), in lateral choroid plexus (CP) isolated from rat and an evolutionarily ancient vertebrate, dogfish shark (Squalus acanthias). CP from both species exhibited concentrative, specific, and metabolism-dependent TR transport from bath to subepithelial/vascular space; at steady state, TR accumulation in vascular/subepithelial space was substantially higher than in epithelial cells. In rat CP, steady-state TR accumulation in subepithelial/vascular spaces was reduced by Na(+)-replacement, but was not affected by a 10-fold increase in buffer K(+).

Transport of a fluorescent cAMP analog in teleost proximal tubules.

Previous studies have shown that killifish (Fundulus heteroclitus) renal proximal tubules express a luminal membrane transporter that is functionally and immunologically analogous to the mammalian multidrug resistance-associated protein isoform 2 (Mrp2, ABCC2). Here we used confocal microscopy to investigate in killifish tubules the transport of a fluorescent cAMP analog (fluo-cAMP), a putative substrate for Mrp2 and Mrp4 (ABCC4). Steady-state luminal accumulation of fluo-cAMP was concentrative, specific, and metabolism-dependent, but not reduced by high K+ medium or ouabain.

From blood to brain and vice versa: transport processes in choroid plexus can be studied in vitro.

The choroid plexus represents the second barrier between blood and brain besides the blood brain barrier. The barrier function is set up by plexus epithelial cells, which are equipped with a variety of active transport systems. However in contrast to the epithelial organs location and extent of expression of these transporters may be different.