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.

[Reality of psychotherapeutic care with regard to outpatient psychotherapy of elderly people in Münsterland (Westfalia)]. / Versorgungssituation älterer Menschen hinsichtlich ambulanter Richtlinien-Psychotherapie.

The need for efficacy of geriatric psychotherapy as well specialized training in geriatric psychosomatics and psychotherapy is commonly recognized amongst professionals. Despite this, this knowledge is not reflected in everyday life. One consequence of this is that psychotherapy for elderly patients is still the exception. We conducted a study in which 478 practicing psychotherapists in Münsterland (Westfalia) were surveyed by mail questionnaire regarding the number and main diagnosis of their patients of greater than 50 years of age, as well as the elderly-specific therapies or future plans for such therapies they might have. The response rate was 65% (312 psychotherapists who answered the questionnaire). The results showed that patients older than 60 years of age were greatly underrepresented compared to younger patients. Moreover, specific therapies, such as age-specific psychotherapy in groups, were rare. To date, it seems that only a minority of elderly patients with psychiatric and psychosomatic diseases are treated adequately by psychotherapy in the outpatient sector. This was evident even in a region such as Münsterland, which has plentiful psychotherapeutic resources.

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.

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").

[Experiences in the treatment of midfacial fractures using a fixed-angle osteosynthetic system. Biomechanical results]. / Osteosynthetische Versorgung von Mittelgesichtsfrakturen mit einem multidirektionalen winkelstabilen Plattensystem. Biomechanische Ergebnisse.

AIM: Fixed-angle osteosynthetic systems are characterized by mechanical "locking" of the osteosynthetic screw and plate. These systems have found increasing acceptance and use for osteosynthetic fixation and temporary reconstruction of the mandible. The aim of this study was to investigate the applicability and performance of fixed-angle systems in the treatment of midfacial fractures. MATERIAL AND METHOD: A newly developed fixed-angle osteosynthetic plate system (smart lock) was compared to a conventional system using fresh human skulls. The iatrogenically produced zygomatic fractures of the human skulls were treated by osteosynthesis and biomechanically tested. Furthermore, in a dynamic test series, an artificial bone was subjected to an alternating force of 15 N of up to 1,000,000 cycles. The new screws and plates were subjected to further biomechanical tests. RESULTS: The tests using the fixed-angle implants revealed that an increase of stability of up to 40% can be expected after osteosynthetic fixation. Furthermore, the plates resisted 1,000,000 cycles of alternating forces, whereby the conventional systems failed after 170,000 cycles on the average. CONCLUSION: Fixed-angle systems, due to their construction, provide a high degree of stability even in thin bones of the midface. They appear to be promising for the treatment of midfacial fractures.

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.

Dimensional variability of nonstandardized greater taper finger spreaders with matching gutta-percha points.

AIM: The purpose of this research was to determine the compatibility and dimensional variability between nonstandardized gutta-percha points and matching finger spreaders. METHODOLOGY: The diameters of nonstandardized gutta-percha points (n = 15) and matching finger spreaders (n = 15) from different manufacturers (Kerr, Dentsply Maillefer, Vereignigte Dentalwerke and Roeko) were determined and statistically analysed using a profile projector under a magnification of 50 x (+/- 0.002 mm). RESULTS: The dimensions of the finger spreaders and gutta-percha cones were inconsistent. Of the 29 groups of nonstandardized gutta-percha cones evaluated, 22 had standard deviations larger than 0.020 at D1. The standard deviations at D11 were greater than at D1, with the exception of those manufactured by Roeko. Overall, nonstandardized gutta-percha cones made by VDW had the greatest dimensional consistency within each size group; the largest variations were seen in the Dentsply Maillefer gutta-percha points. The 13 sizes of nonstandardized finger spreaders were more consistent. CONCLUSIONS: The results of this study show that corresponding sizes of nonstandardized finger spreaders and gutta-percha cones have statistically significant differences. There were large dimensional variations within sizes and discrepancies between the nominal size and actual size. Thus, these discrepancies may cause problems during root canal filling.

[Corrections using the hexapod]. / Korrekturen mit dem Hexapoden.

The hexapod is a construction that has been subjected to a great deal of investigation in robotics for use in three-dimensional positioning. One use of it is for positioning of the cockpit in flight simulators. Application of the hexapod principle in the external fixator makes it possible to realize prescribed movements of bone fragments with a simple and stable design. The precise setting of the system requires software that has been developed and optimized for clinical use. Translations, axis corrections and rotations are possible individually and also in combinations for correction of complex deformities. The system has advantages, especially in the case of rotations around the longitudinal axis of the bone and in the realization of translation movements. Because the centres of rotation are taken into account by the mathematical calculations, the planning of corrections is simplified. The hexapod system is described, and its clinical application is presented with reference to case reports.

Fracture reduction and deformity correction with the hexapod Ilizarov fixator.

A configuration for the Ilizarov external fixator with six distractors and 12 ball joints in the form of a hexapod was developed. The system allows for six degrees of freedom bone fragment displacement by controlling the distractors. Using this assembly, universal three-dimensional corrections or reductions are possible without the need for complicated joint mechanisms. The device was used in 16 patients: five had displaced tibial fractures with severe soft tissue damage, 10 had deformities or pseudarthroses subsequent to treatment of tibial fractures, and one had an axis deviation in the course of tibial lengthening. Translational (to 40 mm) and rotational deformities (to 33 degrees) were corrected. Final radiographic examinations after the correction procedure was complete showed median residual deformities of 3.5 mm (range, 0-5 mm) and 1 degree (range, 0 degree-4 degrees) in the anteroposterior projection and of 1.5 mm (range, 0-6 mm) and less than 1 degree (range, 0 degree-9 degrees) in the lateral projection. The construction is a useful and important addition to the Ilizarov fixator system. As a bone fixation device it is unique in that its optimal use depends on the availability of computer software.

Follow-up evaluation of open intra-articular fractures of the calcaneus.

The results of a follow-up evaluation of open intra-articular calcaneal fractures are presented. A modified Merle d'Aubigné functional score and Zwipp radiographic score were used. A retrospective analysis of 35 patients with 36 open intra-articular fractures represents the basis of the study. At the time of follow-up examination (on average 44 months after the injury), 5 amputations of the affected extremity and 4 ankle arthrodeses had been carried out. The 23 patients still able to bear weight on the affected hindfoot and possessing a functional ankle joint were radiographically and functionally evaluated. No excellent results were documented. Only 6 good functional and 2 good radiographic outcomes were noted. In 17 instances, a poor functional or radiographic score was given. Devastating results were seen in the course of treatment of third-degree open joint depression or comminuted intra-articular fractures (n = 15): 9 cases of osteomyelitis, 5 amputations, 1 partial calcanectomy, 1 arthrodesis. An open reduction as part of the primary treatment (n = 6) led to local complications in all instances. The most favorable results were seen after nonoperative fracture management: complication-free course of treatment in 4 of 11 patients. All workmen's injuries led to a permanent disability, and these patients received compensation. The treatment and salvage of the soft-tissue envelope should be paramount in all therapeutic decisions. The fracture treatment must not further jeopardize these tissues. An aggressive operative treatment of local complications, including arthrodesis or amputation, is recommended.

[Transoral metal implant removal after ventral C2/C3 spondylodesis in pharyngo-vertebral fistula]. / Die transorale metallentfernung nach ventraler spondylodese c2/c3 bei pharyngovertebraler fistel.

A 26-year-old man sustained a C2 arc fracture. Ventral spondylodesis using an H-plate was performed. The patient developed a pharyngovertebral fistula which remained undetected for 1 year. Spontaneous fusion of C3/C4 and osteolysis of the cortical block occurred. The fistula was demonstrated intraoperatively and the implant was transorally removed. No further problems occurred after this unusual method of treatment. The anatomy of the cervical spine, special problems of intensive care patients and the use of proper instrumentation are discussed.

[Aplasia of the articular process of the 2nd cervical vertebra]. / Aplasie eines gelenkfortsatzes am 2. halswirbelkörper.

The X-ray diagnosis of a contusion of the cervical spine showed unilateral aplasia of the inferior articular process of C2 in a 7-year-old boy. The literature, diagnosis and differential diagnosis are discussed.

[Dangers and risks of thoracic drainage at the accident site]. / Gefahren und Risiken der am Unfallort gelegten Thoraxdrainagen.

For several years it has been argued that a chest tube should be placed at the scene of an accident if thoracic trauma is suspected. However, during emergency treatment in hospital it has been observed that a high number of such tubes have been placed incorrectly. To validate this impression, we conducted a retrospective analysis of the clinical course of 33 trauma victims who had chest tubes placed at the scene of accident. It was found that 39.4% of the chest tubes were placed completely incorrectly and 21.2% required some correction; 39.4% were placed correctly. In two cases (6.1%) life-threatening complications developed because of the chest tube, necessitating a thoracotomy in 1 patient and repeated pericardial punction in the other. Based on the results of our study we believe that a more critical attitude should be adopted to the placement of chest tubes at the scene of the accident.

[Significance of isthmic spondylolisthesis in expert assessment of occupational disease of the lumbar spine]. / Die Bedeutung der isthmischen Spondylolisthesis in der Begutachtung der Berufskrankheit der Lendenwirbelsäule.

In Germany, disc-related disease of the lumbar spine is eligible for workmen's compensation if caused by long-standing work requiring heavy lifting or carrying or extreme trunk-bending (BK 2108). The appraisal of causality is particularly difficult if conditions like isthmic spondylolisthesis preexist. 250 consecutive appraisals in nurses concerning the BK 2108 were analysed, 12 applicants (4.8%) had isthmic spondylolisthesis (4.6% of females and 5.9% of males). The literature about the natural history of isthmic spondylolisthesis is reviewed. A person who has isthmic spondylolisthesis is up to 25% more likely to have significant back trouble during his life than one who does not. Back pain in adults associated with spondylolisthesis is usually heralded by back pain in the late teens or early twenties. Progression of the slip is rarely seen after maturity. Due to the loss of protection by the posterior elements the disc is prone to premature degeneration which, however, does not become clinically apparent in most cases. Longstanding vocational heavy lifting or excessive stooping can negatively influence the natural history of isthmic spondylolisthesis. It can produce symptomatic disease in a person who would otherwise have remained asymptomatic, or it can cause a deterioration in those with preexisting symptoms. Criteria for the appraisal of causality are proposed. It is stressed that the course of the disease in relation to age and vocational strains has to be analysed in each individual case.

[Universal 3-dimensional correction and reposition with the ring fixator using the hexapod configuration]. / Universelle dreidimensionale Korrektur und Reposition mit dem Ringfixateur unter Anwendung der Hexapod-Anordnung.

A new configuration for the Ilisarov fixator with 6 distractors and 12 ball joints in the form of a hexapod is proposed. Using this assembly, a correction or reduction is possible with respect to any given point and axis in space. The primary position of the rings is not critical. The fixator system is statically determined and there is no stress between the longitudinal rods. Difficult corrections like those necessary for rotational deformities can be done without complicated joint mechanisms.

[The transparent tibia]. / Der transparente Unterschenkel.

To keep damage to vascular and neural structure in the lower leg to a minimum when Ilizarov ring fixators are mounted, a transparent model of the lower leg has been designed and produced. In this model the course of the vascular and neural structures is shown anatomically correct relative to the bones of the lower leg. This model makes it easier to imagine the spatial relations and helps in correct placement of the Kirschner wires in the lower leg.

[Development and characterization of an absorbable temporary wound dressing]. / Entwicklung und charakterisierung einer absorbierbaren temporären Wundabdeckung.

Most of the temporary dressings used in the treatment of burns do not meet the objectives of a skin substitute concerning application, safety and comfort. Removal is often painful and traumatic and increases the risk of infection. Biodegradable polymers of lactic and caproic acid were developed as part of a research programme (BMFT/FRG 01 KG 8809/7), and chemical and physical properties were investigated. Films made of the copolymer material were characterized by structure, transparency, permeability, tensile strength, flexibility and degradation. The transparent films appeared increasingly opaque during hydrolysis. The water vapour permeance could be varied between 40 and 250 (40-136) ml/m2 per h (according to the method of measurement). The mechanical properties are characterized by a maximum elongation of > 2000% at 37 degrees C and a very low elastically modulus. When the results were compared with those of three established film dressings, no restriction was found in the aptitude of the material as a wound dressing.