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1.  Impairment of small somatic and autonomic nerve fibres in intensive care unit patients with severe sepsis and critical illness polyneuropathy – a single center controlled observational study 
BMC Neurology  2013;13:159.
Axonal damage in large myelinated nerve fibres occurs in about 70% of patients with severe sepsis, known as critical illness polyneuropathy and contributes significantly to an increased short- and long-term morbidity and mortality in this population. Among other pathophysiological mechanisms, autonomic dysregulation, characterized by high concentrations of circulating catecholamines in the presence of impaired sympathetic modulation of heart and vessels have been discussed. We hypothesize that autonomic small fibre neuropathy play an important role in autonomic failure.
Single center, non-randomized, controlled, observational study. Skin biopsies of patients with severe sepsis and/or septic shock are compared with those of age-matched controls. In order to assess impairment of small nerve fibres, skin biopsies are taken at onset of severe sepsis, and two and 16 weeks later. Intraepidermal nerve fibre densities are histologically analyzed using anti protein gene product (PGP) 9.5 immunostaining. In addition, standardized clinical examinations, as Medical Research Council (MRC) scores of muscle strength, Rankin scores, and standardized nerve conduction studies of the right median nerve, the right tibial nerve, the left fibular nerve, and both sural nerves are performed, to identify critical illness polyneuropathy and to neurophysiologically quantify the damage of large nerve fibres.
The study will allow to describe the frequency of small fibre neuropathy in patients with severe sepsis up to four months after onset of severe sepsis and to evaluate its relationship to critical illness polyneuropathy.
Trial registration
The trial has been registered to the German Clinical Trials Register. The trial registration number is DRKS-ID: DRKS00000642.
PMCID: PMC4228411  PMID: 24176121
Critical illness polyneuropathy; CIP; Severe sepsis; Skin biopsies; Small fibre neuropathy
2.  Muscle ultrasound for early assessment of critical illness neuromyopathy in severe sepsis 
Critical Care  2013;17(5):R227.
Muscle ultrasound is emerging as a promising tool in the diagnosis of neuromuscular diseases. The current observational study evaluates the usefulness of muscle ultrasound in patients with severe sepsis for assessment of critical illness polyneuropathy and myopathy (CINM) in the intensive care unit.
28 patients with either septic shock or severe sepsis underwent clinical neurological examinations, muscle ultrasound, and nerve conduction studies on days 4 and 14 after onset of sepsis. 26 healthy controls of comparable age underwent clinical neurological evaluation and muscle ultrasound only.
26 of the 28 patients exhibited classic electrophysiological characteristics of CINM, and all showed typical clinical signs. Ultrasonic echogenicity of muscles was graded semiquantitatively and fasciculations were evaluated in muscles of proximal and distal arms and legs. 75% of patients showed a mean echotexture greater than 1.5, which was the maximal value found in the control group. A significant difference in mean muscle echotexture between patients and controls was found at day 4 and day 14 (both p < 0.001). In addition, from day 4 to day 14, the mean grades of muscle echotexture increased in the patient group, although the values did not reach significance levels (p = 0.085). Controls revealed the lowest number of fasciculations. In the patients group, fasciculations were detected in more muscular regions (lower and upper arm and leg) in comparison to controls (p = 0.08 at day 4 and p = 0.002 at day 14).
Muscle ultrasound represents an easily applicable, non-invasive diagnostic tool which adds to neurophysiological testing information regarding morphological changes of muscles early in the course of sepsis. Muscle ultrasound could be useful for screening purposes prior to subjecting patients to more invasive techniques such as electromyography and/or muscle biopsy.
Trial registration
German Clinical Trials Register, DRKS-ID: DRKS00000642.
PMCID: PMC4057413  PMID: 24499688
3.  Multi-Timescale Conformational Dynamics of CD2AP SH3C using NMR and Accelerated Molecular Dynamics** 
A complete understanding of the relationship between biological activity and molecular conformation requires an understanding of the thermally accessible potential energy landscape. An extensive set of experimental NMR residual dipolar couplings (RDCs) has been used to determine the conformational behavior of CD2AP SH3C on multiple timescales, using the Gaussian Axial Fluctuation model, and comparison to restraint-free accelerated molecular dynamics simulation. These robust analyses provide a comprehensive description of conformational fluctuations on picosecond to millisecond timescales. While the β-sheets show negligible slow motions, larger amplitude slow dynamics are found in the n-SRC and RT loops that mediate physiological interactions.
PMCID: PMC3541011  PMID: 22565613
NMR; Protein Dynamics; RDC; Molecular Dynamics; Molecular recognition; spin relaxation
4.  Junction formation of Cu3BiS3 investigated by Kelvin probe force microscopy and surface photovoltage measurements 
Recently, the compound semiconductor Cu3BiS3 has been demonstrated to have a band gap of ~1.4 eV, well suited for photovoltaic energy harvesting. The preparation of polycrystalline thin films was successfully realized and now the junction formation to the n-type window needs to be developed. We present an investigation of the Cu3BiS3 absorber layer and the junction formation with CdS, ZnS and In2S3 buffer layers. Kelvin probe force microscopy shows the granular structure of the buffer layers with small grains of 20–100 nm, and a considerably smaller work-function distribution for In2S3 compared to that of CdS and ZnS. For In2S3 and CdS buffer layers the KPFM experiments indicate negatively charged Cu3BiS3 grain boundaries resulting from the deposition of the buffer layer. Macroscopic measurements of the surface photovoltage at variable excitation wavelength indicate the influence of defect states below the band gap on charge separation and a surface-defect passivation by the In2S3 buffer layer. Our findings indicate that Cu3BiS3 may become an interesting absorber material for thin-film solar cells; however, for photovoltaic application the band bending at the charge-selective contact has to be increased.
PMCID: PMC3323917  PMID: 22497001
buffer layer; Cu3BiS3; Kelvin probe force microscopy; solar cells

Results 1-5 (5)