Gary E. Mueller 《加拿大化工杂志》1999,77(1):132-135

The radial void fraction distribution of equal sized spheres in cylindrical packed bed tubes with low diameter aspect ratios (1 ≤ D/d ≤ 2) is determined from the spheres' center coordinates, the local radial void faction and the radial positions within the tubes. A correlation that closely predicts the local radial void fraction at a radial position is determined from the radial void fraction distributions. The correlation is a function of the diameter aspect ratio and the radial position in the cylindrical packed bed tubes.  相似文献   

    

TJ Barstow  AM Scremin  DL Mutton  CF Kunkel  TG Cagle  BJ Whipp 《Canadian Metallurgical Quarterly》1996,28(10):1221-1228

We examined the ability of patients with spinal cord injury to undergo adaptations to chronic exercise training (cycle ergometry) invoked by functional electrical stimulation (FES) of the legs. Nine such patients performed incremental and constant work rate exercise before and after exercise training. Exercise sessions averaged 2.1 +/- 0.4/wk, and consisted of 30 min/session of continuous FES recumbent cycling with increasing work rate as tolerated. Peak VO2 and peak work rate significantly improved with training. Peak VO2 was significantly correlated with peak heart rate both before and after training (r = 0.97 pre and 0.85 post, P < 0.01 for both). The time course of the VO2, VCO2 and VE responses to constant-load exercise (unloaded cycling) and in recovery (mean response time MRT) were very long prior to training, and became significantly faster following training. However, there was no correlation between percentage improvement in either MRTon or MRToff for VO2 and the percentage increase in peak VO2. Exercise tolerance in these patients with spinal cord injury appears to be a direct function of the ability to increase heart rate. Further, exercise training can elicit significant improvements in both exercise tolerance and in gas exchange kinetics, even when performed only twice per week. However, these improvements may be accomplished by different mechanisms.  相似文献   

    

TJ Smith  SJ Foster 《Canadian Metallurgical Quarterly》1995,177(13):3855-3862

  相似文献   

    

DR Mueller  CW Clark  DL Ederer  JJ Jia  WL O'Brien  QY Dong  TA Callcott 《Canadian Metallurgical Quarterly》1995,52(6):4457-4461

  相似文献   

    

EK Insko  TJ Connick  MD Schnall  SG Orel 《Canadian Metallurgical Quarterly》1997,37(5):778-784

An RF multicoil array for high resolution imaging of the breast is presented. The RF multicoil is incorporated into a dedicated breast imaging apparatus that holds either breast in gentle compression during imaging. Simulations and imaging experiments demonstrate the high sensitivity and RF homogeneity of the multicoil array. Direct comparisons are made between the multicoil and a surface coil. In vivo images are presented to demonstrate the homogeneity of the RF field of the multicoil over the entire breast. An in vivo image of both high temporal and spatial resolution is shown, which demonstrates the sensitivity of the RF multicoil array that may be achieved in a practical imaging experiment.  相似文献   

    

PJ Morgan  G Harrison  PP Freestone  D Crane  AJ Rowe  TJ Mitchell  PW Andrew  RJ Gilbert 《Canadian Metallurgical Quarterly》1997,412(3):563-567

Proteolytic cleavage of the bacterial protein toxin pneumolysin with protease K creates two fragments of 37 and 15 kDa. This paper describes the purification of these two fragments and their subsequent physical and biological characterisation. The larger fragment is directly involved in the cytolytic mechanism of this pore-forming protein, via membrane binding and self-association. The smaller fragment lacks ordered structure or discernible activity.  相似文献   

    

TJ Chang  TC Chang  SM Lin  SF Huang  YH Pai 《Canadian Metallurgical Quarterly》1998,97(12):860-865

Thyrotropin (TSH)-secreting pituitary adenoma (TSPA) is a rare cause of hyperthyroidism and detailed reports of this entity in Taiwan are uncommon. We report a patient with TSPA with symptoms of hyperthyroidism and describe the presentation, endocrine and histologic findings, and treatment. The patient, a 42-year-old man, presented with a 2-year history of weight loss, palpitation, anxiety, and bad temper. He had increased basal serum thyroxine (T4, 18.3 micrograms/dL) and triiodothyronine (T3, 250 ng/dL) concentrations. The TSH concentration was normal (4.6 microIU/mL) and showed impaired response to stimulation by TSH-releasing hormone. Tests for antithyroid antibodies were negative. Thyroid scintigraphy showed mild thyroid enlargement. The thyroid uptake of radioactive iodine (131I) was high at 2 hours (34%) and 24 hours (63%) after 131I administration. Other serum hormone concentrations were within normal limits. Magnetic resonance imaging of the brain showed a microadenoma in the pituitary region. Octreotide and bromocriptine tests showed 78.4% and 58.3% inhibition of TSH, respectively. The patient underwent trans-sphenoidal pituitary tumor excision, and the symptoms of hyperthyroidism subsided after surgery. Six months after the operation, there was no evidence of recurrence of the tumor or symptoms of hyperthyroidism. Hormonal supplements were also not necessary. In conclusion, TSPA is a rare cause of hyperthyroidism. However, in patients with symptoms of hyperthyroidism and increased basal serum T1 and T3 concentrations, but normal or even elevated serum TSH concentrations, TSPA should be considered in the differential diagnosis.  相似文献   

    

JV Wu  TJ Shuttleworth  P Stampe 《Canadian Metallurgical Quarterly》1996,154(3):275-282

Calcium-activated potassium channels (maxi K+ channels) isolated from avian nasal salt gland cells were reconstituted into lipid bilayers and characterized. The 266 pS channel is blocked discretely by charybdotoxin from the external solution at nanomolar concentrations and by Ba2+ from the cytosolic side at micromolar concentrations. Fast tetraethylammonium (TEA) block is seen as apparent reductions in amplitude of the unitary currents. From the extent of the reductions, TEA binding affinity was calculated to be 0.16 mM from the external solution and 37 mm from internal solution. The overall channel properties conform to those of maxi K+ channels in other epithelial tissues. The calcium sensitivity of the channel was found to be variable from channel to channel, extending over a wide range of concentrations from 1 to 1,000 microM. Examination of the pooled calcium titration curves, revealed that these curves are grouped into five clusters, and the probability distribution of the clusters matches a binomial distribution. The Hill coefficient derived from the titration curves varies from 1 to 5 and is linearly correlated to calcium binding with a slope of 1 per 10-fold change in Kd. Clustered titration curves with such a characteristic suggest that the gating components and the calcium binding sites of the maxi K+ channels in the avian nasal gland are hetero-tetrameric and may result from random mixing of two distinct subunits possessing high and low calcium sensitivities, respectively.  相似文献   

    

TJ Dosios  DC Angouras  DG Floros 《Canadian Metallurgical Quarterly》1998,66(6):2098-2099

We describe a unique case of a de novo desmoid tumor of the posterior mediastinum in a 21-year-old nulligravida. The tumor recurred twice despite its histologically confirmed radical extirpations. Because of the aggressive local behavior of desmoid tumors and their unusual locations, which prevent wide excision margins, we favor the early consideration of adjuvant therapy.  相似文献   

    

TE Miller  S Margalit  TJ Creamer 《Canadian Metallurgical Quarterly》1996,17(2):182-4, 186-8, 190

Gas-plasma-treated, woven polyethylene fabric to reinforce heavily filled composite resin was used to fabricate a direct/indirect fixed partial denture to esthetically replace a missing maxillary central incisor for a 12-year-old boy. The patient and his parents were interested in using a fixed prosthesis as an interim space-maintaining restoration, which would boost the patient's self-esteem. The technique used was an amalgamation of old concepts and new procedures that enable general dentists to expeditiously and inexpensively replace missing teeth. This relatively noninvasive and basically reversible procedure allows the patient to ponder the final restoration as he or she goes through growth, development, and maturation of the hard and soft tissues.  相似文献