Hidden charge states in soft-x-ray laser-produced nanoplasmas revealed by fluorescence spectroscopy.

Highly charged ions are formed in the center of composite clusters by strong free-electron laser pulses and they emit fluorescence on a femtosecond time scale before competing recombination leads to neutralization of the nanoplasma core. In contrast to mass spectrometry that detects remnants of the interaction, fluorescence in the extreme ultraviolet spectral range provides fingerprints of transient states of high energy density matter. Spectra from clusters consisting of a xenon core and a surrounding argon shell show that a small fraction of the fluorescence signal comes from multiply charged xenon ions in the cluster core. Initially, these ions are as highly charged as the ions in the outer shells of pure xenon clusters with charge states up to at least 11+.

[Mild dementia and driving ability. Part 1: Fundamentals]. / Beginnende Demenz und Fahreignung. Teil 1: Grundlagen.

Physiological changes, but most of all diseases, affect driving ability in old age, whereby cognitive and mental performance plays an important part. Impaired health and feeling of unease while driving are the main reasons for driving cessation in the elderly. The causes of crashes and crash development show typical features compared to younger drivers. In the assessment of accident frequency and crash risk, sophisticated analyses are necessary. A person with moderate to severe dementia is certainly no longer fit to drive, whereas driving ability may be maintained in mild dementia for some time. In part 2, comprehensive information on the practice of assessment and judgement of driving ability is provided.

[Mild dementia and driving ability. Part 2: Assessment and its consequences in practice]. / Beginnende Demenz und Fahreignung. Teil 2: Das Assessment und seine praktischen Konsequenzen.

The legal framework and the essentials in traffic and transport psychology and statistics were described in part 1. Safe driving depends on different sensory and mental processes interacting in a complicated manner. Physiological changes and--even more importantly--a variety of diseases result in impaired performance in these functional areas. Moderate to severe dementia certainly means that the person is no longer fit to drive, whereas driving ability may be maintained in mild dementia for some time. There are different approaches and assessment tools, but a single test that could, on its own, answer the question whether a patient with mild dementia is fit to drive does not exist. Driving ability is not only determined by cognitive function. Further assessment of possible risk factors and overall functioning is necessary. If dementia is diagnosed, then the question of fitness to drive must be promptly discussed with the patient because during the course of dementia driving ability will inevitably be lost. The conclusion of the assessment of driving ability must not be pronounced like a verdict, the physician should rather counsel and support the patient and his family on the difficult road towards driving cessation.

Allelic variation in genes encoding Panton-Valentine leukocidin from community-associated Staphylococcus aureus.

Community-associated methicillin-resistant Staphylococcus aureus isolates characteristically contain the genes for Panton-Valentine leukocidin (PVL), which is a proposed virulence factor. To determine whether different alleles of the PVL genes lukS-PV and lukF-PV occur, and whether they are associated with specific genetic lineages of S. aureus, sequences from 28 S. aureus isolates, representing four different multilocus sequence types, and bacteriophages SLT and PVL were compared. Seven nucleotide polymorphisms were identified, which defined three groups of the lukS-PV and lukF-PV sequence. Only one polymorphism resulted in an amino-acid change. Bacteriophage SLT and isolates of bacteriophage type 80/81 contained the prototypic (founder) lukS-PV and lukF-PV sequence. The alleles were not lineage-specific.

Glucocorticoids inhibit prostaglandin synthesis not only at the level of phospholipase A2 but also at the level of cyclo-oxygenase/PGE isomerase.

1. Prostanoid synthesis was induced in bone marrow-derived macrophages by addition of exogenous arachidonic acid to the cell cultures. When the cells were preincubated with dexamethasone (10(-7) and 10(-6) M) overnight, prostaglandin synthesis was inhibited by 66.5 +/- 2.8% and 56.7 +/- 2.9% (mean +/- s.d.; n = 3) respectively. 2. Endogenous membrane bound phospholipase A2 was measured with labelled phospholipids used as substrates. The enzyme activity with phosphatidylcholine and phosphatidylethanolamine as substrates was inhibited by 27.0 +/- 8.3% and 23.3 +/- 11.1% (n = 4) respectively, in dexamethasone-treated macrophages compared to control cells. Neither the distribution of radiolabelled arachidonic acid among the different phospholipid species nor the release of arachidonic acid from prelabelled cells were significantly impaired by pretreatment of the macrophages with dexamethasone (1 microM). 3. The enzyme activity of the cyclo-oxygenase/prostaglandin E (PGE) isomerase was measured in cell membranes from control cells and dexamethasone-treated cells. It was inhibited by 40.0 +/- 8.4% (n = 4) in dexamethasone-treated cells as compared to control cells. Thus, glucocorticoids inhibit not only phospholipase A2 in these cells, but predominantly inhibit arachidonic acid metabolism subsequent to its release from phospholipids.

The influence of various carbon fibre braiding techniques and methods of fixation on the extensibility of ligament prostheses.

An alloplastic ligament prosthesis with carbon fibres should not only be biocompatible but should also restore the biomechanical function of a natural system, which includes restoring its elasticity. Tests with new types of braided carbon fibre strands showed their elastic extensibility to increase with increasing number of filament tows and increasing braid angle. The best results were obtained with 32 tows and a 43 degrees braid angle. This strand type was tested in vitro as a medial collateral ligament prosthesis with two methods of fixation in human knees and, in like manner, in vivo in sheep knees. Biomechanical tests in vitro using human cadaver knees and sheep knees after 12 weeks' implantation showed an elasticity similar to that of normal natural ligaments.

The body reaction to carbon fibre particles implanted into the medullary space of rabbits.

It is thought that abrasion particles can produce a tissue reaction when alloplastic material is used for prosthetic devices. Therefore it is important to examine the reaction of the tissues and the body to microparticles before introducing a new material. Carbon reinforced carbon is a new material which is suitable for artificial joints because of its physical properties (strength and elasticity). Carbon fibre fragments with a diameter of 7 microns and a length between 20-100 microns were injected in the medullary canal of 16 rabbits, and evaluated after periods of 2 and 12 weeks. Phagocytosis of small carbon fibre fragments by macrophages occurs, but only a minimal foreign body reaction to the intramedullary carbon fibre fragments. There is a small amount of fibrosis around some carbon fibres and a small amount of new bone formation with inclusion of carbon. Only a few carbon fragments are transported to the parenchymal organs. There is no foreign body reaction.

Three-dimensional load measurements in an external fixator.

On the basis of a six-degree-of-freedom adjustable fracture reduction hexapod external fixator, a system which can be used for measuring axial and shear forces as well as torsion and bending moments in the fixator in vivo was developed. In a pilot study on 9 patients (7 fresh fractures and 2 osteotomies of the tibia), the load in the fixator during the healing process was measured after 2, 4, 8 and 12 weeks and at fixator removal. The measured values enabled both the type of fracture to be determined as well as the monitoring of the healing process. In well-reduced type A3 fractures small axial (direction of the bone axis) forces were found in the fixator. A2, B2 and C3 fractures showed distinct axial forces, which decreased during the healing process, according to an increasing load transfer over the bone. Bending moments in the fixator showed good correspondence with the clinical healing process, except in the case of a C3 fracture. A combination of bending moment and axial force proved to be particularly suitable to assess fracture healing. In transverse fractures, the well-known resorption phenomenon of bone in the fracture gap at approximately 4 weeks was detected by the system. Compared with other external fixator load measurements in vivo, the hexapod offers the advantage of being able to measure all forces and moments in the fixator separately and with a relatively simple mechanical arrangement. In our opinion, it will be possible to control fracture healing using this system, thereby minimizing radiation exposure from radiographs. Furthermore, the measurement system is a step towards the development of external fixator systems that enable automatic adjustments of the callus mechanical situation ("automatic dynamization") and inform the patients about the optimal weight bearing of their extremity ("intelligent fixator").

Prevention of thromboembolism with low-molecular-weight heparin in orthopedic surgery: a 5-year experience.

A regimen of prophylaxis of thromboembolism with low molecular weight heparin (LMWH) and unfractionated heparin (UFH) in orthopedic surgery is presented. Over a 5-year period, 11,905 patients have been operated in all fields of orthopedic surgery in a big trauma center. In 498 cases, deep vein thrombosis (DVT) was clinically suspected and phlebography was performed: 122 patients had confirmed DVT (rate 0.98%); 59.8% of the DVT were limited to the calf. Nineteen pulmonary embolisms (rate 0.16%) were diagnosed (3 lethal). Heparin-induced thrombocytopenia type II was diagnosed in 12 of 122 patients. Only one of these had received LMWH. The related rates of DVT were highest for tibial head fractures (12.4%), total knee replacement (6.7%), and multiple trauma (6.4%). The extent of DVT was most severe in multiple trauma. The results proved the regimen to be of good clinical use and showed that more attention has to be paid to fractures, especially of the knee; and to patients with multiple injuries.

[Reaction of the bone- and soft tissues to implanted bone wax in the sheep]. / Die Reaktion des Knochen- und Weichteilgewebes auf implantiertes Knochenwachs beim Schaf

2,5 gr. of bone wax (Knochenwachs) were implanted in the iliac crest of 10 sheep. The induction of a foreign body reaction and chronic inflammation was proven demonstrable until the 12th week after implantation of the bone wax. In this period only partial resorption of the wax occurred simultaneously with significantly retarded osseous regeneration. From a clinical point of view it therefore seems necessary when using bone wax to pay particular attention to inflammatory reactions, reduced new bone formation and eventual occurrence of pseudo-arthrosis.

[Physical flow studies of new surgical aspiration drains]. / Strömungsphysikalische Untersuchungen neuer chirurgischer Saug-Drainagen

Mathematical and experimental results demonstrate that the customary Redon drain as well as the improved Neo-Redovac drain develop suction only over a short initial distance. The above mentioned innovation of three additional oval holes does not increase efficiency. The disadvantage of rapidly diminished suction is overcome in the "Ulmer Drain", in which equidistant openings of continually increasing aperture are aligned towards the drain end.

[Traumatic cysts of the spleen]. / Traumatische Milzcysten

During a routine clinical examination of a 7-year-old girl and a 17-year-old man a large tumor was discovered in the left upper quadrant of the abdomen. Large splenic cyst were found in the spleen at splenectomy. The traumatic etiology of the cysts can be assumed on the basis of histologic results, as well as of a significant history of previous trauma. The etiology, differential diagnosis, therapy, and classification of splenic cysts are discussed.

[Regression trends of neurologic damage in the surgical emergency management of patients with injuries of the cervical vertebrae with spinal cord involvement]. / Die Rückbildungstendenz neurologischer Schäden bei der operativen Sofortversorgung von Halswirbelsäulenverletzten mit Rückenmarksbeteiligung.

Sixty-five patients with cervical spine injuries and varied neurological deficits were treated operatively. Evaluation revealed an improvement in neurological findings dependent upon the promptness of anatomical reduction in patients with incomplete lesions. The more frequent neurological improvement seen with open reduction and internal fixation as compared with closed reduction was not statistically significant but was felt to justify the additional resources required for internal fixation. In complete lesions, there was no evidence that the time of anatomical reduction was related to improvement in neurological findings.