Digital in-line X-ray holography with zone plates.

Single pulse imaging with radiation provided by free-electron laser sources is a promising approach towards X-ray microscopy, which is expected to provide high resolution images of biological samples unaffected by radiation damage. One fully coherent imaging technique for this purpose is digital in-line holography. Key to its successful application is the creation of X-ray point sources with high photon flux.

X-ray holographic microscopy with zone plates applied to biological samples in the water window using 3rd harmonic radiation from the free-electron laser FLASH.

The imaging of hydrated biological samples - especially in the energy window of 284-540 eV, where water does not obscure the signal of soft organic matter and biologically relevant elements - is of tremendous interest for life sciences. Free-electron lasers can provide highly intense and coherent pulses, which allow single pulse imaging to overcome resolution limits set by radiation damage. One current challenge is to match both the desired energy and the intensity of the light source.

Flow conditions in the vicinity of microstructured interfaces studied by holography and implications for the assembly of artificial actin networks.

Microstructured fluidic devices have successfully been used for the assembly of free standing actin networks as mechanical model systems on the top of micropillars. The assembly occurs spontaneously at the pillar heads when preformed filaments are injected into the channel. In order to reveal the driving mechanism of this localization, we studied the properties of the flow profile by holographic tracking.

BioRef: a versatile time-of-flight reflectometer for soft matter applications at Helmholtz-Zentrum Berlin.

BioRef is a versatile novel time-of-flight reflectometer featuring a sample environment for in situ infrared spectroscopy at the reactor neutron source BER II of the Helmholtz Zentrum Berlin für Materialien und Energie (HZB). After two years of design and construction phase the instrument has recently undergone commissioning and is now available for specular and off-specular neutron reflectivity measurements. BioRef is especially dedicated to the investigation of soft matter systems and studies at the solid-liquid interface.

Ptychographic coherent x-ray diffractive imaging in the water window.

Coherent x-ray diffractive microscopy enables full reconstruction of the complex transmission function of an isolated object to diffraction-limited resolution without relying on any optical elements between the sample and detector. In combination with ptychography, also specimens of unlimited lateral extension can be imaged. Here we report on an application of ptychographic coherent diffractive imaging (PCDI) in the soft x-ray regime, more precisely in the so-called water window of photon energies where the high scattering contrast between carbon and oxygen is well-suited to image biological samples.

Differential clinical characteristics, medication usage, and treatment response of bipolar disorder in the US versus The Netherlands and Germany.

Increased early-onset bipolar illness was seen in the US compared with the Netherlands and Germany (abbreviated here as Europe), but other clinical characteristics, medication use, and treatment response have not been systematically explored. Outpatients with bipolar disorder were treated naturalistically and followed prospectively at four sites in the US and three in Europe. Data and clinical characteristics were collected from patient questionnaires, and medication usage and good-to-excellent response to treatment for at least 6 months ascertained from daily clinician ratings on the National Institutes of Mental Health-Life Chart Method.

Spectral analysis by XANES reveals that GPNMB influences the chemical composition of intact melanosomes.

GPNMB is a unique melanosomal protein. Unlike many melanosomal proteins, GPNMB has not been associated with any forms of albinism, and it is unclear whether GPNMB has any direct influence on melanosomes. Here, melanosomes from congenic strains of C57BL/6J mice mutant for Gpnmb are compared to strain-matched controls using standard transmission electron microscopy and synchrotron-based X-ray absorption near-edge structure analysis (XANES).

STXMPy: a new software package for automated region of interest selection and statistical analysis of XANES data.

Background: Soft X-ray spectromicroscopy based absorption near-edge structure analysis, is a spectroscopic technique useful for investigating sample composition at a nanoscale of resolution. While the technique holds great promise for analysis of biological samples, current methodologies are challenged by a lack of automatic analysis software e. g.

Quantification of the adhesion strength of fibroblast cells on ethylene glycol terminated self-assembled monolayers by a microfluidic shear force assay.

The adhesion strength of cells depends on the properties of the surface they attach to. Varying the surface properties can trigger different cellular responses such as differentiation. In order to study cell adhesion quantitatively, we developed a microfluidic shear force assay which allows the variation of applied shear stress by five orders of magnitude.

The role of "inert" surface chemistry in marine biofouling prevention.

The settlement and colonization of marine organisms on submerged man-made surfaces is a major economic problem for many marine industries. The most apparent detrimental effects of biofouling are increased fuel consumption of ships, clogging of membranes and heat exchangers, disabled underwater sensors, and growth of biofoulers in aquaculture systems. The presently common-but environmentally very problematic-way to deal with marine biofouling is to incorporate biocides, which use biocidal products in the surface coatings to kill the colonizing organisms, into the surface coatings.

Soft X-ray holographic microscopy of chromosomes with high aspect ratio pinholes.

We used digital in-line soft X-ray holography (DIXH) in the Gabor geometry to image human chromosomes. The divergent wave front was generated by diffraction of synchrotron radiation from a high aspect ratio pinhole. As under our experimental conditions the achievable resolution depends on the pinhole radius, high aspect ratio holes with diameters in the 100 nm range were prepared by focused ion beam (FIB) milling.

In situ characterization of thermo-responsive poly(N-isopropylacrylamide) films with sum-frequency generation spectroscopy.

The thermo-responsive behaviour of thiol modified poly(N-isopropylacrylamide) (pNIPAM) films immobilized on gold are probed by in situ broadband sum-frequency generation (SFG) spectroscopy. The pNIPAM films were prepared by atom transfer radical polymerization (ATRP) using a nitro-biphenyl-thiol (NBT)-SAM on a polycrystalline gold surface as a substrate. Additionally, Raman and infrared reflection absorption spectroscopy (IRRAS) are applied to spin-coated pNIPAM films.

Computer simulation of water-mediated forces between gel-phase phospholipid bilayers.

Water-mediated forces between gel-phase phospholipid bilayers were calculated as a function of interbilayer separation using the grand canonical Monte Carlo technique and all-atom CHARMM force field. The mechanism of the short-range interbilayer repulsion proved to be similar to that calculated previously for the fluid-phase bilayers despite substantial differences in structure and areal density between the gel and fluid phases.

Cognitive functioning in euthymic bipolar I and bipolar II patients.

Objective: There is growing evidence of cognitive impairment as a trait factor in bipolar disorder. The generalizability of this finding is limited because previous studies have either focussed exclusively on bipolar I disorder or have analysed mixed patient groups. Thus, it is still largely unknown whether bipolar II patients perform differently from bipolar I patients on measures of cognitive functioning.

Analysis of holographic microscopy data to quantitatively investigate three-dimensional settlement dynamics of algal zoospores in the vicinity of surfaces.

In this article we describe the technical aspects of digital in-line holographic microscopy to track multiple macrofouling Ulva linza zoospores simultaneously during their exploration of surfaces. Using an effective method of artefact suppression at the edges of holograms in combination with projection of volume reconstructions, a fast algorithm was developed which allows a reliable determination of a large number of subsequent spore positions. Thus, statistical analysis of swimming behaviour in the vicinity of surfaces becomes possible.

Preliminary results of a fine-grain analysis of mood swings and treatment modalities of bipolar I and II patients using the daily prospective life-chart-methodology.

Objective: The study aimed to increase the knowledge about the detailed course differences between different forms of bipolar disorder.

Method: Using the prospective life-chart-clinician version, we compared the fine-grain analysis of mood swings and treatment modalities of 18 bipolar II with 31 bipolar I patients.

Results: During an observational period of a mean of 26 months we observed an increase of euthymic days, and a decrease of (sub)depressive and (hypo)manic days.

Physicochemical properties of (ethylene glycol)-containing self-assembled monolayers relevant for protein and algal cell resistance.

The influence of the number of repeating units in self-assembled monolayers (SAMs) of ethylene glycol and of their end-group termination on the settlement and adhesion of two types of algal cells, viz., zoospores of the macroalga Ulva and cells of the diatom Navicula , was studied. The findings are related to the resistance of these surfaces against fibrinogen adsorption.

Digital in-line holography with femtosecond VUV radiation provided by the free-electron laser FLASH.

Femtosecond vacuum ultraviolet (VUV) radiation provided by the free-electron laser FLASH was used for digital in-line holographic microscopy and applied to image particles, diatoms and critical point dried fibroblast cells. To realize the classical in-line Gabor geometry, a 1 microm pinhole was used as spatial filter to generate a divergent light cone with excellent pointing stability. At a fundamental wavelength of 8 nm test objects such as particles and diatoms were imaged at a spatial resolution of 620 nm.

Resistance of polysaccharide coatings to proteins, hematopoietic cells, and marine organisms.

The interaction of covalently coupled hyaluronic acid, alginic acid, and pectic acid with proteins, cells (hematopoietic KG1a and Jurkat cells), and marine organisms (algal zoospores and barnacle cypris larvae) is compared. In contrast to cells and proteins for which such polysaccharide coatings are known for their antiadhesive properties, marine algal spores and barnacle cyprids were able to colonize the surfaces. Of the three polysaccharides, hyaluronic acid showed the lowest settlement of both Ulva zoopores and barnacles.

Coherent-pulse 2D crystallography using a free-electron laser x-ray source.

Coherent diffractive imaging for the reconstruction of a two-dimensional (2D) finite crystal structure with a single pulse train of free-electron laser radiation at 7.97 nm wavelength is demonstrated. This measurement shows an advance on traditional coherent imaging techniques by applying it to a periodic structure.

[Specific aspects of treatment for women with bipolar affliction].

This manuscript summarizes specific issues in the disease course and pharmacological treatment of women with bipolar disorders. Gender differences relevant to the female biology manifest in symptoms, outcome, and course. The preponderance of depressive symptoms is typical, and the risk of rapid cycling is estimated to be eight times higher for women than for men.

Structured and gradient polymer brushes from biphenylthiol self-assembled monolayers by self-initiated photografting and photopolymerization (SIPGP).

The self-initiated photografting and photopolymerization (SIPGP) of styrene, methyl methacrylate, and tert-butyl methacrylate on structured self-assembled monolayers (SAMs) of electron beam cross-linked omega-functionalized biphenylthiols SAMs on gold was investigated. Polymer brushes with defined thickness can be prepared on crosslinked benzyl-, phenyl-, hydroxyl-, and amino-functionalized SAMs, whereas non-cross-linked SAM regions desorb from the surface during the SIPGP process. By the preparation of brush gradients on different functionalized SAMs, it was demonstrated that the resulting polymer brush layer thickness is determined by the locally applied electron beam dosage.

Zeta potential of motile spores of the green alga Ulva linza and the influence of electrostatic interactions on spore settlement and adhesion strength.

The zeta potential of the motile spores of the green alga (seaweed) Ulva linza was quantified by video microscopy in combination with optical tweezers and determined to be -19.3+/-1.1 mV.