Notizen: Die Spektren der Photoneutronen aus den Reaktionen C12(y,n)C11 und O16(y,n)O15

Photoneutron energy spectra and yields from carbon and oxygene were measured using 31 Mev bremsstrahlung. The neutrons were detected via the recoil protons in a stilbene crystal. The energy spectrum of the photoneutrons from the O16(y,n) -reaction shows pronounced structure.

[Relevance of personal contextual factors of the ICF for use in practical social medicine and rehabilitation]

Personal contextual factors play an essential part in the model of the International Classification of Functioning, Disability and Health (ICF). The WHO has not yet classified personal factors for global use although they impact on the functioning of persons positively or negatively. In 2010, the ICF working group of the German Society of Social Medicine and Prevention (DGSMP) presented a proposal for the classification of personal factors into 72 categories previously arranged in 6 chapters. Now a positioning paper has been added in order to stimulate a discussion about the fourth component of the ICF, to contribute towards a broader and common understanding about the nature of personal factors and to incite a dialogue among all those involved in health care as well as those people with or with-out health problems in order to gain a comprehensive perspective about a person's condition.

[Prolonged weaning: S2k-guideline published by the German Respiratory Society]

Mechanical ventilation (MV) is an essential part of modern intensive care medicine. MV is performed in patients with severe respiratory failure caused by insufficiency of the respiratory muscles and/or lung parenchymal disease when/after other treatments, i. e. oxygen, body position, secretion management, medication or non invasive ventilation have failed.In the majority of ICU patients weaning is routine and does not present any problems. Nevertheless 40-50 % of the time during mechanical ventilation is spent on weaning. About 20 % of patients need continued MV despite resolution of the conditions which originally precipitated the need for MV.There maybe a combination of reasons; chronic lung disease, comorbidities, age and conditions acquired in ICU (critical care neuromyopathy, psychological problems). According to an International Consensus Conference the criteria for "prolonged weaning" are fulfilled if patients fail at least three weaning attempts or require more than 7 days of weaning after the first spontaneous breathing trial. Prolonged weaning is a challenge. An inter- and multi-disciplinary approach is essential for weaning success. Complex, difficult to wean patients who fulfill the criteria for "prolonged weaning" can still be successfully weaned in specialised weaning units in about 50% of cases.In patients with unsuccessful weaning, invasive mechanical ventilation has to be arranged either at home or in a long term care facility.This S2-guideline was developed because of the growing number of patients requiring prolonged weaning. It is an initiative of the German Respiratory Society (Deutsche Gesellschaft für Pneumologie und Beatmungsmedizin e. V., DGP) in cooperation with other societies engaged in the field.The guideline is based on a systematic literature review of other guidelines, the Cochrane Library and PubMed.The consensus project was chaired by the Association of Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF) based on a formal interdisciplinary process applying the Delphi-concept. The guideline covers the following topics: Definitions, epidemiology, weaning categories, pathophysiology, the spectrum of treatment strategies, the weaning unit, discharge from hospital on MV and recommendations for end of life decisions. Special issues relating to paediatric patients were considered at the end of each chapter.The target audience for this guideline are intensivists, pneumologists, anesthesiologists, internists, cardiologists, surgeons, neurologists, pediatricians, geriatricians, palliative care clinicians, nurses, physiotherapists, respiratory therapists, ventilator manufacturers.The aim of the guideline is to disseminate current knowledge about prolonged weaning to all interested parties. Because there is a lack of clinical research data in this field the guideline is mainly based on expert opinion.

Mesopattern of immobilised bone morphogenetic protein-2 created by microcontact printing and dip-pen nanolithography influence C2C12 cell fate

Making meso matter: bone morphogenetic protein-2 (BMP-2) mesopattern created by dip-pen nanolithography and microcontact printing were applied to cell differentiation.

Smad-interacting protein 1 affects acute and tonic, but not chronic pain

BACKGROUND

Smad-interacting protein 1 (also named Zeb2 and Zfhx1b) is a transcription factor that plays an important role in neuronal development and, when mutated, causes Mowat-Wilson syndrome (MWS). A corresponding mouse model carrying a heterozygous Zeb2 deletion was comprehensively analysed in the German Mouse Clinic. The most prominent phenotype was the reduced pain sensitivity. In this study, we investigated the role of Zeb2 in inflammatory and neuropathic pain.

METHODS

For this, we tested mutant Zeb2 animals in different models of inflammatory pain like abdominal constriction, formalin and carrageenan test. Furthermore, we studied the pain reactivity of the mice after peripheral nerve ligation. To examine the nociceptive transmission of primary sensory dorsal root ganglia (DRG) neurons, we determined the neuronal activity in the spinal dorsal horn after the formalin test using staining of c-Fos. Next, we characterized the neuronal cell population in the DRGs and in the sciatic nerve to study the effect of the Zeb2 mutation on peripheral nerve morphology.

RESULTS

The present data show that Zeb2 is involved in the development of primary sensory DRG neurons, especially of C- and Aδ fibres. These alterations contribute to a hypoalgesic phenotype in inflammatory but not in neuropathic pain in these Zeb2(+/-) mice.

CONCLUSION

Our data suggest that the under-reaction to pain observed in MWS patients results from a reduced responsivity to nociceptive stimulation rather than an inability to communicate discomfort.

Effects of short sustained lung inflations on cerebral blood flow and cerebral tissue oxygenation in the juvenile rabbit

BACKGROUND

Sustained lung inflations improve oxygenation but may impair hemodynamics. This study aimed to determine effects of short sustained inflations on cerebral blood flow and cerebral tissue oxygenation in experimental lung injury.

METHODS

Experiments were performed in 6 juvenile ventilated New Zealand white rabbits. The effects of a series of sustained inflations at 20, 25 and 30 cmH2O pressure for 15 seconds duration each on hemodynamics, cerebral blood flow and cerebral tissue oxygenation were determined by laser Doppler flowmetry and cerebral tissue oxygen tension measurement in naive animals, after surfactant depletion and subsequent fluid filling of the lung.

RESULTS

During the series of sustained inflations the mean arterial blood pressure decreased by 73%, 52% and 32% and the mean cerebral blood flow decreased by 73%, 39% and 30% in naive animals, after surfactant depletion and with fluid filling of the lung respectively. Arterial oxygen saturation was maintained or increased, while mean cerebral tissue oxygenation decreased by 48% (naive), 8% (surfactant depletion) or increased by 81% (surfactant depletion and fluid filling). Three minutes after the sustained inflations blood gases were similar to the blood gases prior to the sustained inflations.

CONCLUSION

A series of short sustained lung inflations of 15 seconds duration can impair cerebral blood flow but increase arterial oxygen saturation in this juvenile animal model. The combination of these effects resulted in either a decrease or increase in regional cerebral tissue oxygenation.

Forces during the controlled displacement of organic molecules

In the ongoing effort to miniaturize the functional elements in electronic devices, molecular dimensions are currently approached. Scanning probe microscopy has demonstrated fascinating capabilities for bottom-up fabrication of atomically defined prototype structures. However, little is known about the underlying interactions during the manipulation of functional organic molecules with a scanning probe tip. Here, we demonstrate the use of noncontact atomic force microscopy at cryogenic temperatures for the lateral displacement of the organic prototype molecule 3,4,9,10-perylene-tetracarboxylicacid-dianhydride on the Ag(111) surface. During repeated manipulation cycles, we measure the precise lateral and vertical tip-molecule force profiles as well as the energy dissipation before and during the manipulation process. The jump of the molecule to an adjacent equivalent substrate lattice site occurs in the regime of repulsive lateral forces, thus constituting a "pushing" mechanism.

Inbred wild type mouse strains have distinct spontaneous morphological phenotypes

The mouse is the most commonly used animal for modelling human disease. New approaches for generating genetically manipulated mouse models to represent human disease, as well as target the function of specific genes, has increased the importance of mice in biomedical science. For the correct interpretation of alterations in mouse phenotype the basic morphology of background mouse strains must be known. Despite on-going efforts to create publicly available baseline phenotypic data, the information concerning spontaneous lesions in wild-type mice is incomplete and scattered so far, and further studies are needed. We addressed this problem by screening haematoxylin-eosin stained sections of brain, reproductive organs, urinary bladder, kidney, thyroid, parathyroid, heart, lung, spleen, thymus, lymph nodes, adrenal glands, stomach, intestine, liver, skin and pancreas of six commonly used inbred mouse strains (C57BL6/J, C57BL6/NTac, C3HeB/FeJ, BALB/cByJ, 129P2/OlaHsd and FVB/N) for inherent spontaneous morphological lesions. Interesting spontaneous phenotypes were seen in morphology of the liver, pancreas, adrenal glands, lungs, intestines and heart. In conclusion, care should be taken when choosing the background mouse strain for genetic manipulations, since different mouse strains harbour different inherent lesions that can affect the function of targeted genes, interpretation of results and translation of results to model human disease.

Electronic structure of spatially aligned graphene nanoribbons on Au(788)

We report on a bottom-up approach of the selective and precise growth of subnanometer wide straight and chevron-type armchair nanoribbons (GNRs) on a stepped Au(788) surface using different specific molecular precursors. This process creates spatially well-aligned GNRs, as characterized by STM. High-resolution direct and inverse photoemission spectroscopy of occupied and unoccupied states allows the determination of the energetic position and momentum dispersion of electronic states revealing the existence of band gaps of several electron volts for straight 7-armchair, 13-armchair, and chevron-type GNRs in the electronic structure.