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排序方式: 共有1185条查询结果,搜索用时 31 毫秒
311.
HB Mortensen KJ Robertson HJ Aanstoot T Danne RW Holl P Hougaard JA Atchison F Chiarelli D Daneman B Dinesen H Dorchy P Garandeau S Greene H Hoey EA Kaprio M Kocova P Martul N Matsuura EJ Schoenle O S?vik PG Swift RM Tsou M Vanelli J Aman 《Canadian Metallurgical Quarterly》1998,15(9):752-759
Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross-sectional, non-population-based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4-6.3%, mean 5.4%). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 +/- 1.3% (mean +/- SD) compared with 8.9 +/- 1.8% in those aged 12-18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg(-1) 24 h(-1)) in children aged 2-9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37% (n = 1071) used three or more. Of those on two or three injections daily, 37% used pre-mixed insulins, either alone or in combination with short- and intermediate-acting insulin. Pre-adolescent children on pre-mixed insulin showed similar HbA1c levels to those on a combination of short- and long-acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long-acting insulin. Among adolescent boys, lower HbA1c was related to use of more short-acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few. 相似文献
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HB Muss 《Canadian Metallurgical Quarterly》1994,21(1):107-113
Hereditary fructose intolerance (HFI) is a potentially fatal autosomal recessive disease of carbohydrate metabolism. HFI patients are deficient in aldolase B, the isozyme expressed in fructose-metabolizing tissues. The eight protein coding exons, including splicing signals, of the aldolase B gene from one American HFI patient were amplified by the polymerase chain reaction (PCR). Single-strand conformational polymorphism (SSCP) analysis and direct sequence determination were applied to the amplified fragments. The mutations in the patient's alleles were identified as a nonsense mutation (R59op) in exon 3 and a missense mutation (C134R) in exon 5. These mutations were confirmed by sequence determination of cloned PCR-amplified exons 3 and 5 from the patient. Allele specific oligonucleotide (ASO) hybridizations of amplified exons 3 and 5 showed the Mendelian inheritance of both mutations. Site-directed mutagenesis was used to generate an expression plasmid for the C134R mutation, and the mutant enzyme was expressed in bacteria. Assays of partially purified enzyme preparations showed that this missense mutation results in an apparently unstable enzyme that retains partial activity. This is the first evidence for a partially active aldolase B from an HFI individual with an identified mutation, and supports the hypothesis that adequate gluconeogenesis/glycolysis is maintained in HFI patients by the presence of partially active enzymes. 相似文献
314.
Fatigue life prediction of a cable harness in an industrial robot using dynamic simulation 总被引:1,自引:0,他引:1
Ji Won Yoon Tae Won Park Hong Jae Yim 《Journal of Mechanical Science and Technology》2008,22(3):484-489
The cable which transfers the signal and power in an industrial robot has a problem of fatigue fracture like steel components.
Since the cable is very flexible compared to other components of the system, it is difficult to estimate its motion numerically.
Some studies have been done on a large deformation problem, especially in a cable, and a few attempts have been made to apply
the absolute nodal coordinate formulation (ANCF), which can simulate a large deformation. Only researches about the fatigue
life of structural cables or comparative studies of FEM and ANCF simulations can be found. This paper presents a method to
simulate the behavior of the cable harness using the ANCF and to predict the fatigue life while computing the strain time
history of the point of interest. Rigid body dynamics is applied for the robot system, while ANCF is used for the cable harness.
The simulation is performed by using the dynamic analysis process. The material property of the cable is obtained by a test.
A simplified model is prepared. With these data, the behavior of the cable is simulated and the fatigue life is predicted. 相似文献
315.
HB Skinner DJ Kilgus J Keyak EE Shimaoka AS Kim JS Tipton 《Canadian Metallurgical Quarterly》1994,(305):178-189
Fundamental to the development of a durable, uncemented femoral component is an understanding of the remodeling process that goes on after implantation. Predicting the bone remodeling that results from the use of a given hip implant would facilitate the design of a prosthesis that would optimize bone adaptation. This report combines the results of finite element stress analysis of the AML prosthesis implanted in vitro into a proximal femur with quantitative bone mineral density measured in vivo in the medial and lateral aspects of human femora at periods after implantation. Unimplanted femora were also analyzed for comparison purposes. Bone density measurements were obtained using dual energy x-ray absorptiometry. Absolute values of the maximum principal stress and maximum shear stress calculated in the femur at the time of implantation accurately predict bone density resulting from remodeling caused by the prosthesis. The calculated initial strain was not found to correlate with resultant bone density. These findings suggest that the results of stress analyses using three dimensional models of femora implanted in vitro can predict bone remodeling around prostheses and may be used to quantitate appropriate design criteria for total hip replacements. 相似文献
316.
This article focuses on the implementation of a dual-mode controller for the maneuver of a two-axis flexible robotic arm. The joint angle trajectory tracking is accomplished by proportional and derivative and feedforward controllers. Based on the pole placement technique, a linear stabilizer is designed for elastic mode stabilization in the plane perpendicular to each joint axis. The stabilizer is switched on when the trajectory reaches the vicinity of the terminal state. The effect of switching time of the stabilizer and varying payload on arm vibration are investigated. With the proposed control system, accurate joint angle tracking and elastic mode stabilization can be accomplished. © 1993 John Wiley & Sons, Inc. 相似文献
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320.
Human invasive soft-tissue infections caused by group A Streptococcus are associated with significant morbidity and mortality. To investigate the pathogenesis of these serious infections, we characterized the host response to bacterial challenge with an M-type 3 isolate recovered from a patient with necrotizing fasciitis, or with isogenic gene replacement mutants deficient in cysteine protease, hyaluronic acid capsule, or M protein in a murine model of human invasive soft-tissue infection. Animals challenged with the wild-type or cysteine protease-deficient strain developed spreading tissue necrosis at the site of inoculation, became bacteremic, and subsequently died. Histopathologic examination of the necrotic lesion revealed bacteria throughout inflamed subcutaneous tissue. Arterioles and venules in the subcutaneous layer were thrombosed and the overlying tissue was infarcted. In contrast, animals challenged with either an acapsular or M protein-deficient mutant developed a focal area of tissue swelling at the site of inoculation without necrosis or subsequent systemic disease. Histopathologic examination of the soft-tissue lesion demonstrated bacteria confined within a well-formed subcutaneous abscess. We conclude that the group A streptococcal hyaluronic acid capsule and M protein, but not the cysteine protease, are critical for the development of tissue necrosis, secondary bacteremia, and lethal infection in a murine model of human necrotizing fasciitis. 相似文献