Thermoelastic Response of the Juno Spacecraft's Solar Array/Magnetometer Boom and Its Applicability to Improved Magnetic Field Investigation.

Juno was inserted into a polar orbit about Jupiter on 4 July 2016. Juno's magnetic field investigation acquires vector measurements of the Jovian magnetic field using a pair of a triaxial Fluxgate Magnetometers (FGMs) colocated with four attitude-sensing star cameras on an optical bench. The optical bench is placed on a boom at the outer extremity of one of Juno's three solar arrays. The Magnetic Field investigation (MAG) uses measurements of the optical bench inertial attitude provided by the micro-Advanced Stellar Compass (µASC) to render accurate vector measurements of the planetary magnetic field. During periJoves, orientation of the MAG Optical Benches (MOB) is determined using the spacecraft (SC) attitude combined with transformations between SC and MOB coordinate frames. Substantial prelaunch effort was expended to maximize the thermomechanical stability of the Juno solar arrays and MAG boom. Nevertheless, the Juno flight experience demonstrates that the transformation between SC and MAG reference frames varies significantly in response to spacecraft thermal excursions associated with large attitude maneuvers and proximate encounters with Jupiter. This response is monitored by comparing attitudes provided by the MAG investigation's four Camera Head Units (CHUs) with those provided by the Stellar Reference Unit (SRU). These systematic variations in relative orientation are thought to be caused by the thermoelastic flexure of the Juno solar array in response to temperature excursions associated with maneuvers and heating during close passages of Jupiter. In this paper, we investigate these thermal effects and propose a model for compensation of the MAG boom flexure.

Transmission electron microscopy specimen preparation method for multiphase porous functional ceramics.

An optimum method is proposed to prepare thin foil transmission electron microscopy (TEM) lamellae of multiphase porous functional ceramics: prefilling the pore space of these materials with an epoxy resin prior to focused ion beam milling. Several advantages of epoxy impregnation are demonstrated by successful preparation of TEM specimens that maintain the structural integrity of the entire lamella. Feasibility of the TEM alignment procedure is demonstrated, and ideal TEM analyses are illustrated on solid oxide fuel cell and solid oxide electrolysis cell materials. Some potential drawbacks of the TEM specimen preparation method are listed for other samples.

Geometrical characterization of interconnected phase networks in three dimensions.

In electrochemical devices such as fuel cells or batteries the microstructure is a determining factor for the performance of the device. To be able to optimize the microstructure it is important to be able to quantitatively measure key structural parameters, such that systematic studies can be made. We present several general methods for quantitative characterization of network structures without prior assumptions of shape or application. The characterization is performed by extracting distributions of values rather than single value descriptions, thus allowing more detailed comparisons between samples to be made. The methods characterize tortuosity, path diameters, the novel dead ends property and a particle shape independent alternative to a particle size distribution. The parameters are calculated by the computation of arrival time maps by the fast marching method. The methods are applied to the analysis of each of the three phases in a solid oxide fuel cell sample.

A framework for automatic segmentation in three dimensions of microstructural tomography data.

Routine use of quantitative three dimensional analysis of material microstructure by in particular, focused ion beam (FIB) serial sectioning is generally restricted by the time consuming task of manually delineating structures within each image slice or the quality of manual and automatic segmentation schemes. We present here a framework for performing automatic segmentation of complex microstructures using a level set method. The technique is based on numerical approximations to partial differential equations to evolve a 3D surface to capture the phase boundaries. Vector fields derived from the experimentally acquired data are used as the driving forces. The framework performs the segmentation in 3D rather than on a slice by slice basis. It naturally supplies sub-voxel precision of segmented surfaces and allows constraints on the surface curvature to enforce a smooth surface in the segmentation. Two applications of the framework are illustrated using solid oxide cell materials as examples.

[Bullying as health hazard among school children]. / Mobning som sundhedstrussel blandt store skoleelever.

The objective was to analyse bullying in relation to sociodemographic factors, health, well-being, and health behaviours. The study is the 1998 Danish contribution to the international WHO-coordinated study Health Behaviour in School-aged Children. It includes 5,205 11-15 year-old students from a random sample of 55 schools who answered a standardized questionnaire. Twenty-five percent were bullied several times during the academic year, most frequently among the youngest students, and independent of sex; 32% bullied others, boys more frequently than girls; the frequency increased with age. Bullying was associated with low social class. Bullying varied considerably among schools. The victims had more problems as regards health, well-being and self-esteem; they smoked and drank less than others. Those who bullied others also had more problems but to a much smaller extent than the victims. They had higher levels of risk behaviours such as smoking, drinking, and seat-belt avoidance, and were less satisfied with school. In conclusion, victims of bullying have a very high proportion of health problems, poor well-being and low self-esteem. To bully others is significantly associated with health risk behaviours.

Efficacy and safety of prolonged thromboprophylaxis with a low molecular weight heparin (dalteparin) after total hip arthroplasty--the Danish Prolonged Prophylaxis (DaPP) Study.

The aim of this study was to compare the efficacy and safety of prolonged (35 days) thromboprophylaxis with a standard length (7 days) regimen of a low molecular weight heparin in patients undergoing total hip arthroplasty. The study was multicentre, randomised, double-blind, and prospective with two groups. Following seven days on a standard length regimen of dalteparin (5000 antifactor Xa units subcutaneously once daily starting 12 h before surgery), patients were randomized to continue the prophylaxis with either subcutaneous injections of dalteparin or placebo injections for a further 28 days. Efficacy was evaluated at the end of the study (day 35) in all patients with bilateral ascending phlebography to detect deep vein thrombosis. Bleeding complications and other adverse events were registered throughout the study period. Three hundred consecutive patients agreed to participate before the operation: 281 were finally randomised and 215 completed the study; two patients died before randomisation; 17 developed deep vein thrombosis; none developed pulmonary embolism; and five of 113 patients (4.4%, 95% CI 1-10%) developed deep vein thrombosis in the dalteparin group, compared with 12 of 102 (11.8%; 95% CI 6-20%) in the placebo group (p=0.039). Deep vein thrombosis in the proximal veins was diagnosed in one patient (0.9%; 95% CI 0-5%) in the dalteparin group, and in five (5.0%; 95% CI 2-11%) in the placebo group (p=0.076). Major bleeding was observed in one patient in the placebo group; minor bleeding complications and adverse events were equally distributed between the groups. We concluded that prolonged (35 days) thrombo prophylaxis with dalteparin is more effective than a standard length (7 days) regimen without increased risk of bleeding complications or other adverse events.

Triplex US in the diagnosis of asymptomatic deep venous thrombosis.

PURPOSE: To evaluate the accuracy of triplex ultrasound (TUS) compared with venography as a screening test for deep venous thrombosis (DVT), and to evaluate interobserver variation in the interpretation of the venographic studies. MATERIAL AND METHODS: A total of 133 postoperative hip fracture patients, asymptomatic of DVT, were prospectively examined with TUS and venography. All venograms were reviewed blindly and in case of disagreement a consensus was arrived at. RESULTS: The incidence of DVT was 20%, with isolated calf vein thrombi in 63% of the cases. There were 7 false-negative and one false-positive result/s at TUS, with a sensitivity of 74%, specificity of 99% and accuracy of 97%. The kappa values ranged from 0.58 to 0.82. The false-negative results were all caused by missed calf vein thrombi in technically inadequate examinations. At sonography 2% of vein segments were noninterpretable, compared to 29% at venography. CONCLUSION: Venous US is less sensitive as a test for DVT in this study of asymptomatic patients than in earlier studies on symptomatic patients. Still, sonographic screening of high-risk patients would be both effective and cost effective. Fresh thrombi may cause a false-negative compression test.

[Brodie abscess. Primarily misinterpreted as traumatic lesion]. / Brodies absces. Primoert fejltolket som traumefølger.

Two case histories are presented. In the first, a 49 year-old man fell on his right hip. He was able to walk, but because of pain he came to our emergency room. Radiographics gave an impression of an undislocated intertrochanteric fracture, scintigraphy confirmed the suspicion. There were no signs of infection. On starting osteosynthesis with the drilling of a hole in the lateral cortex, discharge of pus was observed and curettage of the abscess cavity was performed. In the second, a 21 year-old man hit his right knee against a table. Because of pain he was admitted to hospital. Primary signs of a lesion of the lateral meniscus were found and arthroscopy was scheduled. When readmitted we found signs of an infection and X-ray revealed a Brodie's abscess in the proximal tibia. The abscess cavity was opened and curettage was performed. Radiographics, scintigraphics, blood parameters and pathological and microbiological investigations revealed primary chronic osteomyelitis in both patients. Antibiotic therapy was instituted and six weeks after primary operation bone transplantation was performed. The further course was uncomplicated.

Arthrodesis after infected knee arthroplasty using long arthrodesis nail. A report of five cases.

Safe methods to perform secondary arthrodesis in the treatment of infected total knee arthroplasty (TKA) after revision arthroplasty has failed are increasingly needed as TKA becomes more common. Possible treatments include external fixation (with single- or double-framed fixators), internal fixation, or amputation. This article reports five cases of infected TKA treated with arthrodesis using a long intramedullary nail. Arthrodesis was performed in a two-stage manner, with surgical revision and insertion of a long intramedullary nail. All arthrodeses healed on an average of 4.8 months.

Computer registration of infections used to measure the effect of prophylactic antibiotics on postoperative infections following osteosynthesis in hip fractures.

Continuous registration of operations and wound infections was used to demonstrate the effect of prophylactic antibiotics in hip fracture osteosynthesis. In order to monitor wound infections and other postoperative complications in an orthopaedic department, 2 years' data on 688 patients with hip fractures, were entered into a personal computer program. During 1990, there was no formal policy for antibiotic prophylaxis; during 1991 prophylactic cefuroxime was recommended for osteosynthesis of hip fractures. In 1990 56% of patients were given prophylaxis and in 1991 this rose to 79%. Overall, 68% of patients had prophylaxis. The overall rate of deep wound infections (DWI) was significantly lower in patients treated with prophylactic antibiotics (0.6%), compared with those without prophylaxis (4.6%). Patients with DWI were admitted to the hospital for an average of 43.7 days, compared with 14.6 days for patients without complications. We recommend the use of prophylactic cefuroxime in hip fracture osteosynthesis. Computer registration of complications is a useful method for clinical quality control in an orthopaedic department.

[The thromboprophylactic effect of low molecular weight heparin (Fragmin) in hip fracture surgery. A placebo controlled trial]. / Den tromboprofylaktiske effekt af lavmolekylaer heparin (Fragmin) ved hoftefrakturkirurgi. En placebokontrolleret undersøgelse.

A prospective, randomized, double-blind trial concerning prophylaxis of thrombosis in 82 patients undergoing hip fracture surgery was conducted to compare a new low-molecular-weight heparin (Fragmin) with a placebo. Deep venous thrombosis (DVT) was detected by I125-fibrinogen uptake test followed by ascending phlebography when positive. Sixty-eight patients completed the study and a 50% reduction in the incidence of DVT was demonstrated: 9/30 (30%) patients in the treatment group and 22/38 (50DVT. This significant difference was achieved by one daily dose of 5.000 IU Fragmin subcutaneously, commencing preoperatively and continuing for six days. No differences in bleeding nor other complications in the two groups were observed. Fragmin administered once daily offers an effective and safe prophylaxis of thrombosis in hip fracture surgery.

The thromboprophylactic effect of a low-molecular-weight heparin (Fragmin) in hip fracture surgery. A placebo-controlled study.

A prospective, randomized, double-blind trial concerning thromboprophylaxis in 82 patients in whom hip fracture surgery was performed was conducted to compare a new low-molecular-weight heparin (Fragmin) with placebo. Deep venous thrombosis (DVT) was detected by 125-I-fibrinogen uptake test followed by ascending phlebography when positive. Sixty-eight patients completed the study, and a 50% reduction in the incidence of DVT was demonstrated: nine of 30 patients in the treatment group (30%) and 22 of 38 patients in the placebo group (58%) developed DVT. This significant difference was achieved by one daily dose of 5000 IU Fragmin subcutaneously, commenced preoperatively and continued for six days. There were no differences in bleeding or other complications in the two groups. Fragmin given once daily offers an effective and safe thromboprophylaxis in hip fracture surgery.

Gentamicin-collagen sponge for local applications. 10 cases of chronic osteomyelitis followed for 1 year.

A bovine collagen sponge containing gentamicin was applied locally in 10 patients with chronic osteomyelitis who were then followed for 1 year postoperatively. No adverse effects or recurrence of infections was observed. The release of gentamicin from the sponge was more complete and rapid than has been reported with polymethyl methacrylate (PMMA) beads. Compared with previous reports on PMMA beads, a much higher gentamicin concentration in the wound exudate can be expected after implantation of the collagen sponge, which is easy to apply and does not require a second operation for removal.

Thromboprophylaxis by low-molecular-weight heparin in elective hip surgery. A placebo controlled study.

In a double-blind, randomised study of thromboprophylaxis in patients undergoing total hip replacement, we compared a low-molecular-weight heparin with a placebo. Of the 120 patients enrolled, 112 completed the trial; 58 in the treatment group and 54 in the placebo group. Nine (16%) patients in the treatment group and 19 (35%) in the placebo group developed deep venous thrombosis, diagnosed by the 125I-fibrinogen uptake test (p < 0.02). Verification was obtained by phlebography in 86% of the patients. Prolonged surgery increased the risk of thrombosis in the placebo group but not in the treatment group (p < 0.05). There were significantly more cases of deep venous thrombosis in the placebo group during the first four postoperative days (p < 0.02). The groups did not differ with respect to peroperative and postoperative bleeding. Low-molecular-weight heparin offers safe and easily administered thromboprophylaxis in total hip replacement.

Out-of-home care in Denmark.

Paradoxically, Denmark has a large number of children in out-of-home care because it has a comprehensive child welfare system. Danish families turn to it for help, and under present social conditions of unemployment and family disruptions, the system is strained. This paper describes a large-scale, government-funded effort to improve the system's policies, programs, and flexible use of placement-treatment resources.

[Prevention of thrombosis in orthopedic surgery]. / Tromboseprofylakse i ortopaedkirurgi.

The high incidence of thromboembolic complications in orthopedic surgery necessitates an effective thromboprophylactic regime. Current methods of prophylaxis are discussed, and principles of thromboprophylaxis with low-molecular weight heparin are presented.

[Post-traumatic subcutaneous emphysema--misdiagnosed as gas gangrene]. / Posttraumatisk subkutant emfysem--fejltolket som gasgangraen.

Two cases of subcutaneous emphysema which developed after minor trauma are presented. One patient had a wound on the tip of the olecranon, and the other an interdigital wound. Both cases were misdiagnosed as gas gangrene, and treated with surgical revision and antibiotics. Neither necrosis nor bacteria were found. Both cases of emphysema were believed to be due to the pumping effect of the movement of the limbs.

The relationship between pressure flow studies and furosemide urography in hydronephrosis.

Patients with hydronephrosis were assessed by furosemide intravenous urography, pressure flow studies and renography. The area increase during furosemide urography was compared to the pressure increase during perfusion and the renographically assessed functional share. We found no correlation between the area increase and the pressure changes during perfusion. Neither was any correlation found between the functional share and the area index. It is concluded that cases of idiopathic hydronephrosis cannot be categorized by the methods currently available.