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排序方式: 共有901条查询结果,搜索用时 343 毫秒
101.
Kennedy E Webb P Walker P Saltzman E Maxwell D Nelson M Booth S 《Food and nutrition bulletin》2011,32(1):60-68
Enormous progress has been made in the past 100 years in improving diet and nutritional status. However, the job is not done. This paper summarizes some of the current challenges and proposes priorities for future research and policy development. The nutrition agenda is more complex than it was 100 years ago. The world now faces undernutrition side-by-side with dietary excess and related chronic diseases. The complexity of modern nutrition necessitates using a systems approach to identifying effective policies and programs. There is a renewed interest in addressing the new nutrition agenda. 相似文献
102.
Klarskov MB Dam HF Petersen DH Hansen TM Löwenborg A Booth TJ Schmidt MS Lin R Nielsen PF Bøggild P 《Nanotechnology》2011,22(44):445702
We present measurements of the electronic properties of graphene using a repositionable micro four-point probe system, which we show here to have unique advantages over measurements made on lithographically defined devices; namely speed, simplicity and lack of a need to pattern graphene. Measurements are performed in ambient, vacuum and controlled environmental conditions using an environmental scanning electron microscope (SEM). The results are comparable to previous results for microcleaved graphene on silicon dioxide (SiO(2)). We observe a pronounced hysteresis of the charge neutrality point, dependent on the sweep rate of the gate voltage; and environmental measurements provide insight into the sensor application prospects of graphene. The method offers a fast, local and non-destructive technique for electronic measurements on graphene, which can be positioned freely on a graphene flake. 相似文献
103.
F Booth 《Canadian Metallurgical Quarterly》1998,317(7153):281-282
104.
105.
Dobutamine-induced hypotension has been disregarded as a marker of more severe functional abnormalities in patients with suspected coronary artery disease. However, its functional significance in patients with myocardial infarction has not been studied. The aim of this study was to define the predictors of systolic blood pressure (SBP) response to dobutamine in patients with previous myocardial infarction. Dobutamine stress (up to 40 microg/kg per minute) echocardiography was performed in 326 patients with prior myocardial infarction referred for evaluation of myocardial ischemia. A 16-segment, four-grade score model was used to assess left ventricular function. Wall motion score index was derived by summation of wall motion score divided by 16. SBP and heart rate increased from rest to peak dobutamine stress (127 +/- 22 vs 134 +/- 27 mm Hg and 72 +/- 14 vs 122 +/- 24 bpm, p < 0.00001 in both). An increase of SBP > or = 30 mm Hg occurred in 50 patients (15%). By multivariate analysis, independent predictors of failure of SBP increase were higher peak wall motion score index (p < 0.001), higher resting SBP (p < 0.01), and medication with calcium channel blockers (p < 0.05). SBP drop > or = 20 mm Hg occurred in 54 patients (17%). Independent predictors of SBP drop were higher resting wall motion score index (p < 0.001), higher resting SBP (p < 0.0001), and older age (p < 0.05). In patients with myocardial infarction, left ventricular function and baseline systolic blood pressure are powerful predictors of SBP response to dobutamine stress testing. 相似文献
106.
Mutations in the Delta7-sterol reductase gene in patients with the Smith-Lemli-Opitz syndrome 总被引:1,自引:0,他引:1
BU Fitzky M Witsch-Baumgartner M Erdel JN Lee YK Paik H Glossmann G Utermann FF Moebius 《Canadian Metallurgical Quarterly》1998,95(14):8181-8186
The Smith-Lemli-Opitz syndrome (SLOS) is an inborn disorder of sterol metabolism with characteristic congenital malformations and dysmorphias. All patients suffer from mental retardation. Here we identify the SLOS gene as a Delta7-sterol reductase (DHCR7, EC 1.3.1. 21) required for the de novo biosynthesis of cholesterol. The human and murine genes were characterized and assigned to syntenic regions on chromosomes 11q13 and 7F5 by fluorescense in situ hybridization. Among the mutations found in patients with the SLOS, are missense (P51S, T93M, L99P, L157P, A247V, V326L, R352W, C380S, R404C, and G410S), nonsense (W151X), and splice site (IVS8-1G>C) mutations as well as an out of frame deletion (720-735 del). The missense mutations L99P, V326L, R352W, R404C, and G410S reduced heterologous protein expression by >90%. Our results strongly suggest that defects in the DHCR7 gene cause the SLOS. 相似文献
107.
Mycobacterium szulgai is a rare cause of human infections, and when present it is mostly known to cause lung infection. We report the first case of isolated Mycobacterium szulgai osteomyelitis in a 68-year-old woman on chronic immunosuppressive therapy. Review of the literature revealed a total of three other cases of M. szulgai osteomyelitis. In all these cases there was evidence of hematogenous or contiguous spread, including one with extensive dissemination. Pulmonary M. szulgai infections tend to occur in patients with chronic lung disease and/or concomitant lung infections, whereas osteomyelitis tends to occur in patients who have severe immunosuppression secondary to disease or drugs. 相似文献
108.
Many studies showed an increased occurrence of primary hyperparathyroidism during lithium therapy. We studied 53 patients receiving lithium therapy prospectively for 2 yr. Serum PTH levels were unequivocally elevated. The baseline PTH level was 2.8 +/- 1.2 pmol/L and increased progressively to 3.9 +/- 1.5 pmol/L after 2 yr (P < 0.0005). There was no change in serum calcium, alkaline phosphatase, inorganic phosphate concentrations or tubular reabsorption of phosphate in relation to glomerular filtration rate. Fasting urinary reabsorption of calcium increased significantly (P < 0.0005), which was concordant with the PTH change. Fasting and 24-h urinary excretion of calcium decreased significantly (P < 0.0005), suggesting reduced, rather than enhanced, bone resorption as in primary hyperparathyroidism. This may be the main mechanism in maintaining normocalcemia, despite PTH elevation, during lithium therapy. 相似文献
109.
110.
K. T. Foster G. Young J. W. Cook D. E. A. Clarke R. H. Kirby M. G. Booth 《BT Technology Journal》1998,16(4):34-47
This paper provides an overview of digital subscriber line (DSL) technology and describes some of the key technical issues facing BT's DSL engineering team. The factors which determine the theoretical information-carrying capacity of BT's access network cables are discussed to give the reader a feel for the potential of the existing access network to deliver broadband services. Transmission on this network will be subject to impairments which will limit the achievable capacity, and there is an urgent need to ensure that all DSL systems are spectrally compatible if the capacity of the network is to be fully realised. 相似文献