109 research outputs found

    Simplified thermal estimation techniques for large space structures

    Get PDF
    A tool for making rapid estimates of the response of space structures to thermal environments encountered in earth orbits is provided for the designer of these structures. Charts giving heating rates and temperatures for certain typical large spacecraft structural elements are provided. Background information for spacecraft thermal design considerations is presented. Environments, requirements, thermal control techniques, design guidelines, and approaches available for more detailed thermal response analysis are discussed

    Lightweight Vacuum Jacket for Cryogenic Insulation - Appendices to Final Report

    Get PDF
    The feasibility is demonstrated of producing a lightweight vacuum jacket using state-of-the-art technology and materials. Design and analytical studies were made on an orbital maneuvering system fuel tank. Preliminary design details were completed for the tank assembly which included an optimized vacuum jacket and multilayered insulation system. A half-scale LH2 test model was designed and fabricated and a force/stiffness proof test was conducted on the vacuum jacket. A vacuum leak rate of 0.00001 was measured, approximately 1500 hours of vacuum pressure was sustained, and 29 vacuum pressure cycles were experienced prior to failure. For vol. 1, see N75-26192

    Potentiation of thrombus instability: a contributory mechanism to the effectiveness of antithrombotic medications

    Get PDF
    © The Author(s) 2018The stability of an arterial thrombus, determined by its structure and ability to resist endogenous fibrinolysis, is a major determinant of the extent of infarction that results from coronary or cerebrovascular thrombosis. There is ample evidence from both laboratory and clinical studies to suggest that in addition to inhibiting platelet aggregation, antithrombotic medications have shear-dependent effects, potentiating thrombus fragility and/or enhancing endogenous fibrinolysis. Such shear-dependent effects, potentiating the fragility of the growing thrombus and/or enhancing endogenous thrombolytic activity, likely contribute to the clinical effectiveness of such medications. It is not clear how much these effects relate to the measured inhibition of platelet aggregation in response to specific agonists. These effects are observable only with techniques that subject the growing thrombus to arterial flow and shear conditions. The effects of antithrombotic medications on thrombus stability and ways of assessing this are reviewed herein, and it is proposed that thrombus stability could become a new target for pharmacological intervention.Peer reviewedFinal Published versio

    Sitting and standing performance in a total population of children with cerebral palsy: a cross-sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Knowledge of sitting and standing performance in a total population of children with cerebral palsy (CP) is of interest for health care planning and for prediction of future ability in the individual child. In 1994, a register and a health care programme for children with CP in southern Sweden was initiated. In the programme information on how the child usually sits, stands, stands up and sits down, together with use of support or assistive devices, is recorded annually.</p> <p>Methods</p> <p>A cross-sectional study was performed, analysing the most recent report of all children with CP born 1990-2005 and living in southern Sweden during 2008. All 562 children (326 boys, 236 girls) aged 3-18 years were included in the study. The degree of independence, use of support or assistive devices to sit, stand, stand up and sit down was analysed in relation to the Gross Motor Function Classification System (GMFCS), CP subtype and age.</p> <p>Result</p> <p>A majority of the children used standard chairs (57%), could stand independently (62%) and could stand up (62%) and sit down (63%) without external support. Adaptive seating was used by 42%, external support to stand was used by 31%, to stand up by 19%, and to sit down by 18%. The use of adaptive seating and assistive devices increased with GMFCS levels (p < 0.001) and there was a difference between CP subtypes (p < 0.001). The use of support was more frequent in preschool children aged 3-6 (p < 0.001).</p> <p>Conclusion</p> <p>About 60% of children with CP, aged 3-18, use standard chairs, stand, stand up, and sit down without external support. Adding those using adaptive seating and external support, 99% of the children could sit, 96% could stand and 81% could stand up from a sitting position and 81% could sit down from a standing position. The GMFCS classification system is a good predictor of sitting and standing performance.</p

    Relationship between distal radius fracture malunion and arm-related disability: A prospective population-based cohort study with 1-year follow-up

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Distal radius fracture is a common injury and may result in substantial dysfunction and pain. The purpose was to investigate the relationship between distal radius fracture malunion and arm-related disability.</p> <p>Methods</p> <p>The prospective population-based cohort study included 143 consecutive patients above 18 years with an acute distal radius fracture treated with closed reduction and either cast (55 patients) or external and/or percutaneous pin fixation (88 patients). The patients were evaluated with the disabilities of the arm, shoulder and hand (DASH) questionnaire at baseline (concerning disabilities before fracture) and one year after fracture. The 1-year follow-up included the SF-12 health status questionnaire and clinical and radiographic examinations. Patients were classified into three hypothesized severity categories based on fracture malunion; no malunion, malunion involving either dorsal tilt (>10 degrees) or ulnar variance (≥1 mm), and combined malunion involving both dorsal tilt and ulnar variance. Multivariate regression analyses were performed to determine the relationship between the 1-year DASH score and malunion and the relative risk (RR) of obtaining DASH score ≥15 and the number needed to harm (NNH) were calculated.</p> <p>Results</p> <p>The mean DASH score at one year after fracture was significantly higher by a minimum of 10 points with each malunion severity category. The RR for persistent disability was 2.5 if the fracture healed with malunion involving either dorsal tilt or ulnar variance and 3.7 if the fracture healed with combined malunion. The NNH was 2.5 (95% CI 1.8-5.4). Malunion had a statistically significant relationship with worse SF-12 score (physical health) and grip strength.</p> <p>Conclusion</p> <p>Malunion after distal radius fracture was associated with higher arm-related disability regardless of age.</p

    Residual platelet ADP reactivity after clopidogrel treatment is dependent on activation of both the unblocked P2Y1 and the P2Y12 receptor and is correlated with protein expression of P2Y12

    Get PDF
    Two ADP receptors have been identified on human platelets: P2Y1 and P2Y12. The P2Y12 receptor blocker clopidogrel is widely used to reduce the risks in acute coronary syndromes, but, currently, there is no P2Y1 blocker in clinical use. Evidence for variable responses to clopidogrel has been described in several reports. The mechanistic explanation for this phenomenon is not fully understood. The aim of this study was to examine mechanisms responsible for variability of 2MeS-ADP, a stable ADP analogue, induced platelet reactivity in clopidogrel-treated patients. Platelet reactivity was assessed by flow cytometry measurements of P-selectin (CD62P) and activated GpIIb/IIIa complex (PAC-1). Residual 2MeS-ADP activation via the P2Y12 and P2Y1 receptors was determined by co-incubation with the selective antagonists AR-C69931 and MRS2179 in vitro. P2Y1 and P2Y12 receptor expression on both RNA and protein level were determined, as well as the P2Y12 H1 or H2 haplotypes. Our data suggest that the residual platelet activation of 2MeS-ADP after clopidogrel treatment is partly due to an inadequate antagonistic effect of clopidogrel on the P2Y12 receptor and partly due to activation of the P2Y1 receptor, which is unaffected by clopidogrel. Moreover, a correlation between increased P2Y12 protein expression on platelets and decreased response to clopidogrel was noticed, r2=0.43 (P<0.05). No correlation was found between P2Y12 mRNA levels and clopidogrel resistance, indicating post-transcriptional mechanisms. To achieve additional ADP inhibition in platelets, antagonists directed at the P2Y1 receptor could be more promising than the development of more potent P2Y12 receptor antagonists

    Health care systems in Sweden and China: Legal and formal organisational aspects

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Sharing knowledge and experience internationally can provide valuable information, and comparative research can make an important contribution to knowledge about health care and cost-effective use of resources. Descriptions of the organisation of health care in different countries can be found, but no studies have specifically compared the legal and formal organisational systems in Sweden and China.</p> <p>Aim</p> <p>To describe and compare health care in Sweden and China with regard to legislation, organisation, and finance.</p> <p>Methods</p> <p>Literature reviews were carried out in Sweden and China to identify literature published from 1985 to 2008 using the same keywords. References in recent studies were scrutinized, national legislation and regulations and government reports were searched, and textbooks were searched manually.</p> <p>Results</p> <p>The health care systems in Sweden and China show dissimilarities in legislation, organisation, and finance. In Sweden there is one national law concerning health care while in China the law includes the "Hygienic Common Law" and the "Fundamental Health Law" which is under development. There is a tendency towards market-orientated solutions in both countries. Sweden has a well-developed primary health care system while the primary health care system in China is still under development and relies predominantly on hospital-based care concentrated in cities.</p> <p>Conclusion</p> <p>Despite dissimilarities in health care systems, Sweden and China have similar basic assumptions, i.e. to combine managerial-organisational efficiency with the humanitarian-egalitarian goals of health care, and both strive to provide better care for all.</p

    The multiplex bead array approach to identifying serum biomarkers associated with breast cancer

    Get PDF
    Introduction Breast cancer is the most common type of cancer seen in women in western countries. Thus, diagnostic modalities sensitive to early-stage breast cancer are needed. Antibody-based array platforms of a data-driven type, which are expected to facilitate more rapid and sensitive detection of novel biomarkers, have emerged as a direct, rapid means for profiling cancer-specific signatures using small samples. In line with this concept, our group constructed an antibody bead array panel for 35 analytes that were selected during the discovery step. This study was aimed at testing the performance of this 35-plex array panel in profiling signatures specific for primary non-metastatic breast cancer and validating its diagnostic utility in this independent population. Methods Thirty-five analytes were selected from more than 50 markers through screening steps using a serum bank consisting of 4,500 samples from various types of cancer. An antibody-bead array of 35 markers was constructed using the Luminex (TM) bead array platform. A study population consisting of 98 breast cancer patients and 96 normal subjects was analysed using this panel. Multivariate classification algorithms were used to find discriminating biomarkers and validated with another independent population of 90 breast cancer and 79 healthy controls. Results Serum concentrations of epidermal growth factor, soluble CD40-ligand and proapolipoprotein A1 were increased in breast cancer patients. High-molecular-weight-kininogen, apolipoprotein A1, soluble vascular cell adhesion molecule-1, plasminogen activator inhibitor-1, vitamin-D binding protein and vitronectin were decreased in the cancer group. Multivariate classification algorithms distinguished breast cancer patients from the normal population with high accuracy (91.8% with random forest, 91.5% with support vector machine, 87.6% with linear discriminant analysis). Combinatorial markers also detected breast cancer at an early stage with greater sensitivity. Conclusions The current study demonstrated the usefulness of the antibody-bead array approach in finding signatures specific for primary non-metastatic breast cancer and illustrated the potential for early, high sensitivity detection of breast cancer. Further validation is required before array-based technology is used routinely for early detection of breast cancer.Kenny HA, 2008, J CLIN INVEST, V118, P1367, DOI 10.1172/JCI33775Shah FD, 2008, INTEGR CANCER THER, V7, P33, DOI 10.1177/1534735407313883Carlsson A, 2008, EUR J CANCER, V44, P472, DOI 10.1016/j.ejca.2007.11.025Nolen BM, 2008, BREAST CANCER RES, V10, DOI 10.1186/bcr2096Brogren H, 2008, THROMB RES, V122, P271, DOI 10.1016/j.thromres.2008.04.008Varki A, 2007, BLOOD, V110, P1723, DOI 10.1182/blood-2006-10-053736Madsen CD, 2007, J CELL BIOL, V177, P927, DOI 10.1083/jcb.200612058Levenson VV, 2007, BBA-GEN SUBJECTS, V1770, P847, DOI 10.1016/j.bbagen.2007.01.017VAZQUEZMARTIN A, 2007, EUR J CANCER, V43, P1117GARCIA M, 2007, GLOBAL CANC FACTS FIMoore LE, 2006, CANCER EPIDEM BIOMAR, V15, P1641, DOI 10.1158/1055-9965.EPI-05-0980Borrebaeck CAK, 2006, EXPERT OPIN BIOL TH, V6, P833, DOI 10.1517/14712598.6.8.833Zannis VI, 2006, J MOL MED-JMM, V84, P276, DOI 10.1007/s00109-005-0030-4Jemal A, 2006, CA-CANCER J CLIN, V56, P106Silva HC, 2006, NEOPLASMA, V53, P538Chahed K, 2005, INT J ONCOL, V27, P1425Jain KK, 2005, EXPERT OPIN PHARMACO, V6, P1463, DOI 10.1517/14656566.6.9.1463Abe O, 2005, LANCET, V365, P1687Paradis V, 2005, HEPATOLOGY, V41, P40, DOI 10.1002/hep.20505Molina R, 2005, TUMOR BIOL, V26, P281, DOI 10.1159/000089260Furberg AS, 2005, CANCER EPIDEM BIOMAR, V14, P33Benoy IH, 2004, CLIN CANCER RES, V10, P7157Song JS, 2004, BLOOD, V104, P2065, DOI 10.1182/blood-2004-02-0449Schairer C, 2004, J NATL CANCER I, V96, P1311, DOI 10.1093/jnci/djh253Hellman K, 2004, BRIT J CANCER, V91, P319, DOI 10.1038/sj.bjc.6601944Roselli M, 2004, CLIN CANCER RES, V10, P610Zhou AW, 2003, NAT STRUCT BIOL, V10, P541, DOI 10.1038/nsb943Hapke S, 2003, BIOL CHEM, V384, P1073Miller JC, 2003, PROTEOMICS, V3, P56Amirkhosravi A, 2002, BLOOD COAGUL FIBRIN, V13, P505Bonello N, 2002, HUM REPROD, V17, P2272Li JN, 2002, CLIN CHEM, V48, P1296Louhimo J, 2002, ANTICANCER RES, V22, P1759Knezevic V, 2001, PROTEOMICS, V1, P1271Di Micco P, 2001, DIGEST LIVER DIS, V33, P546Ferrigno D, 2001, EUR RESPIR J, V17, P667Webb DJ, 2001, J CELL BIOL, V152, P741Gion M, 2001, EUR J CANCER, V37, P355Schonbeck U, 2001, CELL MOL LIFE SCI, V58, P4Blackwell K, 2000, J CLIN ONCOL, V18, P600Carriero MV, 1999, CANCER RES, V59, P5307Antman K, 1999, JAMA-J AM MED ASSOC, V281, P1470Loskutoff DJ, 1999, APMIS, V107, P54Molina R, 1998, BREAST CANCER RES TR, V51, P109Bajou K, 1998, NAT MED, V4, P923Chan DW, 1997, J CLIN ONCOL, V15, P2322Chu KC, 1996, J NATL CANCER I, V88, P1571vanDalen A, 1996, ANTICANCER RES, V16, P2345Yamamoto N, 1996, CANCER RES, V56, P2827KOCH AE, 1995, NATURE, V376, P517HADDAD JG, 1995, J STEROID BIOCHEM, V53, P579FOEKENS JA, 1994, J CLIN ONCOL, V12, P1648GEARING AJH, 1993, IMMUNOL TODAY, V14, P506HUTCHENS TW, 1993, RAPID COMMUN MASS SP, V7, P576DECLERCK PJ, 1992, J BIOL CHEM, V267, P11693GABRIJELCIC D, 1992, AGENTS ACTIONS S, V38, P350BIEGLMAYER C, 1991, TUMOR BIOL, V12, P138DNISTRIAN AM, 1991, TUMOR BIOL, V12, P82VANDALEN A, 1990, TUMOR BIOL, V11, P189KARAS M, 1988, ANAL CHEM, V60, P2299, DOI 10.1021/ac00171a028LERNER WA, 1983, INT J CANCER, V31, P463WESTGARD JO, 1981, CLIN CHEM, V27, P493TROUSSEAU A, 1865, CLIN MED HOTEL DIEU, V3, P654*R PROJ, R PROJ STAT COMP1
    corecore