Super-resolution Imaging of Structure, Molecular Composition, and Stability of Single Oligonucleotide Polyplexes.

The successful application of gene therapy relies on the development of safe and efficient delivery vectors. Cationic polymers such as cell-penetrating peptides (CPPs) can condense genetic material into nanoscale particles, called polyplexes, and induce cellular uptake. With respect to this point, several aspects of the nanoscale structure of polyplexes have remained elusive because of the difficulty in visualizing the molecular arrangement of the two components with nanometer resolution.

Electronic structure and excited state dynamics in a dicyanovinyl-substituted oligothiophene on Au(111).

Dicyanovinyl (DCV)-substituted oligothiophenes are promising donor materials in vacuum-processed small-molecule organic solar cells. Here, we studied the structural and the electronic properties of DCV-dimethyl-pentathiophene (DCV5T-Me2) adsorbed on Au(111) from submonolayer to multilayer coverages. Using a multi-technique experimental approach (low-temperature scanning tunneling microscopy/spectroscopy (STM/STS), atomic force microscopy (AFM), and two-photon photoemission (2PPE) spectroscopy), we determined the energetic position of several affinity levels as well as ionization potentials originating from the lowest unoccupied molecular orbitals (LUMO) and the highest occupied molecular orbitals (HOMO), evidencing a transport gap of 1.

Effects of 60-day bed rest with and without exercise on cellular and humoral immunological parameters.

Exercise at regular intervals is assumed to have a positive effect on immune functions. Conversely, after spaceflight and under simulated weightlessness (e.g.

Orbital redistribution in molecular nanostructures mediated by metal-organic bonds.

Dicyanovinyl-quinquethiophene (DCV5T-Me2) is a prototype conjugated oligomer for highly efficient organic solar cells. This class of oligothiophenes are built up by an electron-rich donor (D) backbone and terminal electron-deficient acceptor (A) moieties. Here, we investigated its structural and electronic properties when it is adsorbed on a Au(111) surface using low temperature scanning tunneling microscopy/spectroscopy (STM/STS) and atomic force microscopy (AFM).

Probing exchange pathways in one-dimensional aggregates with super-resolution microscopy.

Supramolecular fibers are prominent structures in biology and chemistry. A quantitative understanding of molecular exchange pathways in these one-dimensional aggregates was obtained by a combination of super-resolution stochastic optical reconstruction microscopy and stochastic simulation. The potential of this methodology is demonstrated with a set of well-defined synthetic building blocks that self-assemble into supramolecular fibrils.

Correlation between temperature activation of charge-carrier generation efficiency and hole mobility in small-molecule donor materials.

In organic solar cells, free charge carriers are generated at the interface between an electron-donating and an electron-accepting material. The detailed mechanisms of the generation of free charge carriers are still under discussion. In this work, we investigate the influence of temperature on the generation efficiency of free charge carriers in blends of dicyanovinyl substituted oligothiophene (DCVnT) molecules and C60 by quasi-steady-state photoinduced absorption (PIA) measurements.

Optimization of solution-processed oligothiophene:fullerene based organic solar cells by using solvent additives.

The optimization of solution-processed organic bulk-heterojunction solar cells with the acceptor-substituted quinquethiophene DCV5T-Bu 4 as donor in conjunction with PC61BM as acceptor is described. Power conversion efficiencies up to 3.0% and external quantum efficiencies up to 40% were obtained through the use of 1-chloronaphthalene as solvent additive in the fabrication of the photovoltaic devices.

Correlation of π-conjugated oligomer structure with film morphology and organic solar cell performance.

The novel methyl-substituted dicyanovinyl-capped quinquethiophenes 1-3 led to highly efficient organic solar cells with power conversion efficiencies of 4.8-6.9%.

Comparative study of microscopic charge dynamics in crystalline acceptor-substituted oligothiophenes.

By performing microscopic charge transport simulations for a set of crystalline dicyanovinyl-substituted oligothiophenes, we find that the internal acceptor-donor-acceptor molecular architecture combined with thermal fluctuations of dihedral angles results in large variations of local electric fields, substantial energetic disorder, and pronounced Poole-Frenkel behavior, which is unexpected for crystalline compounds. We show that the presence of static molecular dipoles causes large energetic disorder, which is mostly reduced not by compensation of dipole moments in a unit cell but by molecular polarizabilities. In addition, the presence of a well-defined π-stacking direction with strong electronic couplings and short intermolecular distances turns out to be disadvantageous for efficient charge transport since it inhibits other transport directions and is prone to charge trapping.

Interrelation between crystal packing and small-molecule organic solar cell performance.

X-ray investigations on single crystals of a series of terminally dicyanovinyl-substituted quaterthiophenes and co-evaporated blend layers with C(60) give insight into molecular packing behavior and morphology, which are crucial parameters in the field of organic electronics. Structural characteristics on various levels and length scales are correlated with the photovoltaic performance of bulk heterojunction small-molecule organic solar cells.

Side chain variations on a series of dicyanovinyl-terthiophenes: a photoinduced absorption study.

We characterize a series of dicyanovinyl-terthiophenes with different alkyl side chains. Variations of side chain substitution patterns and length mainly affect the morphology of the evaporated thin films, which in turn sensitively influences properties like absorption, energy levels, and thin film roughness. To investigate changes in transfer processes between electron donor (D) and acceptor (A) molecules due to side chain variations, we use photoinduced absorption spectroscopy (PIA).

Evidence for an additional effect of whole-body vibration above resistive exercise alone in preventing bone loss during prolonged bed rest.

Summary: The addition of whole-body vibration to high-load resistive exercise may provide a better stimulus for the reduction of bone loss during prolonged bed rest (spaceflight simulation) than high-load resistive exercise alone.

Introduction: Prior work suggests that the addition of whole-body vibration to high-load resistive exercise (RVE) may be more effective in preventing bone loss in spaceflight and its simulation (bed rest) than resistive exercise alone (RE), though this hypothesis has not been tested in humans.

Methods: Twenty-four male subjects as part of the 2nd Berlin Bed Rest Study performed RVE (n = 7), RE (n = 8) or no exercise (control, n = 9) during 60-day head-down tilt bed rest.

SDS-coated atovaquone nanosuspensions show improved therapeutic efficacy against experimental acquired and reactivated toxoplasmosis by improving passage of gastrointestinal and blood-brain barriers.

Toxoplasmic encephalitis (TE) is the most common clinical manifestation of reactivated infection with Toxoplasma gondii in immunocompromised patients that is lethal if untreated. The combination of pyrimethamine plus sulfadiazine or clindamycin is the standard therapy for the treatment of TE, but these combinations are associated with hematologic toxicity and/or life-threatening allergic reactions. Therefore, alternative treatment options are needed.

The role of apolipoprotein E in uptake of atovaquone into the brain in murine acute and reactivated toxoplasmosis.

We investigated whether coating of atovaquone nanosuspensions (ANSs) with apolipoprotein E (apoE) peptides improves the uptake of atovaquone into the brain. The passage across the blood-brain barrier (BBB) of ANSs stabilized by polysorbate 80 (Tween 80), poloxamer 184 (P184), or poloxamer 338 (P338) and the same formulations coated with apoE peptides were analyzed in vitro and in vivo. Passage through a rat coculture model of the BBB did not differ between individual atovaquone formulations, and the addition of apoE peptides did not enhance the transport.

Nicotine and biochanin A, but not cigarette smoke, induce anti-inflammatory effects on keratinocytes and endothelial cells in patients with Behçet's disease.

During periods of smoking, patients with Behçet's disease have less oral aphthae than in abstinence. To elucidate this observation, human keratinocytes and dermal microvascular endothelial cells (HMEC-1) were incubated with serum of 20 patients with Behçet's disease and 20 healthy controls for 4 hours. Maximum non-toxic concentrations were determined and the cells were further treated with 6 microM nicotine, 3.

Gene expression changes in human cells after exposure to mobile phone microwaves.

Possible biological effects of mobile phone microwaves were investigated in vitro. In this study, which was part of the 5FP EU project REFLEX (Risk Evaluation of Potential Environmental Hazards From Low-Energy Electromagnetic Field Exposure Using Sensitive in vitro Methods), six human cell types, immortalized cell lines and primary cells, were exposed to 900 and 1800 MHz. RNA was isolated from exposed and sham-exposed cells and labeled for transcriptome analysis on whole-genome cDNA arrays.

Prospective identification of postmenopausal osteoporotic women at high vertebral fracture risk by radiography, bone densitometry, quantitative ultrasound, and laboratory findings: results from the PIOS study.

Women with established osteoporosis are at high risk to sustain additional vertebral fractures. Treatment may affect the predictive power of bone densitometry and biochemical techniques. There are few prospective studies comparing fracture prediction by dual-energy X-ray absorptiometry (DXA) and other techniques in treated women with established osteoporosis.

Atovaquone maintenance therapy prevents reactivation of toxoplasmic encephalitis in a murine model of reactivated toxoplasmosis.

Acute therapy with pyrimethamine plus sulfadiazine is the treatment of choice for reactivated toxoplasmic encephalitis (TE). Acute therapy is followed by lifelong maintenance therapy (secondary prophylaxis) with the same drugs at lower dosages. The use of pyrimethamine plus sulfadiazine is hampered by severe side effects including allergic reactions and hematotoxicity.

In vitro investigation of novel calcium phosphates using osteogenic cultures.

A rat bone marrow stromal cell (RBM) culture was used to evaluate novel bioactive calcium phosphate ceramics. Three rapidly resorbable, glassy crystalline materials with the main crystalline phase Ca2KNa(PO4)2 were investigated (sample code GB 1a, GB 14, GB 9). These materials were designed to exhibit a higher degree of biodegradability than tricalcium phosphate.

In vitro investigation of titanium and hydroxyapatite dental implant surfaces using a rat bone marrow stromal cell culture system.

In this study, rat bone marrow cells (RBM) were used to evaluate different titanium and hydroxyapatite dental implant surfaces. The implant surfaces investigated were: a titanium surface having a porous titanium plasma-sprayed coating (sample code Ti-TPS), a titanium surface with a deep profile structure (sample code Ti-DPS), an uncoated titanium substrate with a machined surface (sample code Ti-ma) and a machined titanium substrate with a porous hydroxyapatite plasma-sprayed coating (sample code Ti-HA). RBM cells were cultured on the disc-shaped test substrates for 14 days.

Morphology of the prometamorphic larva of the spadefoot toad, Scaphiopus intermontanus (Anura: Pelobatidae), with an emphasis on the lateral line system and mouthparts.

We provide a detailed description of the larval morphology of the Great Basin spadefoot toad (Scaphiopus intermontanus), a species with documented morphological variability in larval structures associated with feeding. We based our findings on laboratory-raised individuals fed a herbivorous diet. We characterized the morphology of the prometamorphic larva (limited to developmental stages 37 and 38) and then related our findings to the larval ecology of the species.

Evaluation of calcium phosphates and experimental calcium phosphate bone cements using osteogenic cultures.

In this study, rat bone marrow cells (RBM) were used to evaluate two biodegradable calcium phosphate bone cements and bioactive calcium phosphate ceramics. The substances investigated were: two novel calcium phosphate cements, Biocement F and Biocement H, tricalcium phosphate (TCP), surface-modified alpha-tricalcium phosphate [TCP (s)] and a rapid resorbable calcium phosphate ceramic consisting of CaKPO(4) (sample code R5). RBM cells were cultured on disc-shaped test substrates for 14 days.

Rapid analysis of O-acetylated neuraminic acids by matrix assisted laser desorption/ionization time-of-flight mass spectrometry.

N-Acetylneuraminic acid (a sialic acid) occurs mainly as a terminal substituent of oligosaccharides of glycoconjugates. Derivatives of neuraminic acid occur widely, substituted in the amino and hydroxy side chains, as well in the C-9 carbon skeleton. These derivatives are responsible for specific functions of sialic acids during cell-cell, cell-substrate, or cell-virus interactions.

Serum cardiac troponin T as a prognostic marker in early sepsis.

Study Objective: Sepsis is the leading cause of death in the noncardiologic ICU. Maldistributed nutritive blood flow and altered convective and diffusive oxygen transport during sepsis can lead to organ dysfunction and multiple organ failure. One of the causes of myocardial dysfunction is thought to be myocardial ischemia in sepsis; however, conventional biochemical parameters to detect myocardial ischemia lack sensitivity and specificity.

Morphological evaluation of osteoblasts cultured on different calcium phosphate ceramics.

The objective of these investigations was to develop an in vitro test system for evaluating novel rapidly resorbable calcium phosphate ceramics of varying composition. Rat bone marrow cells were cultured on the disc-shaped test substrates for 14 days. Five calcium phosphates were examined: R1 CaNaPO4; R1/M2, composed of CaNaPO4 and MgNaPO4; R1/2, composed of CaNaPO4 and Mg2SiO4; R1 + 9% SiO2 consisting of CaNaPO4 and 9% SiO2 (wt%) and R17, Ca2KNa(PO4)2.