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191.
PET工业丝的高速纺工艺 总被引:1,自引:0,他引:1
Barmag工业丝纺丝拉伸设备拥有从挤出机到卷绕机的各个元件 ,覆盖了所有复杂的应用体系对丝的选择。为了适应改造传统工业丝和高速纺工艺的需要 ,该元件家族已从纺织和地毯领域提高和发展到新的工业丝领域。 相似文献
192.
The paper considers the need to update the development strategy of Russia’s nuclear power industry and various approaches to the large-scale nuclear power development. Problems of making decisions on fast neutron reactors and closed nuclear fuel cycle (NFC) arrangement are discussed. The current state of the development of fast neutron reactors and closed NFC technologies in Russia is considered and major problems are highlighted. 相似文献
193.
JS Wunder G Paulian AG Huvos G Heller PA Meyers JH Healey 《Canadian Metallurgical Quarterly》1998,80(7):1020-1033
Seventy-four patients who had a Ewing sarcoma of bone were managed with preoperative and postoperative chemotherapy and operative resection, with or without postoperative irradiation. The primary objectives of the study were to determine the histological response to preoperative chemotherapy in terms of the percentage of tumor necrosis and to assess the relationship between the histological response and the oncological outcome. The minimum duration of follow-up of the surviving patients who were continuously free of disease was five years. Sections of each operative specimen were examined, and the histological response to chemotherapy was graded semiquantitatively. Grade I indicated necrosis of 50 per cent of the tumor or less; grade II, necrosis of more than 50 per cent but less than 90 per cent; grade III, necrosis of 90 to 99 per cent; and grade IV, necrosis of 100 per cent of the tumor. Of the seventy-four tumors, forty-four (59 per cent) were exquisitely sensitive to chemotherapy and had complete (grade-IV) or nearly complete (grade-III) necrosis. In contrast, fourteen tumors (19 per cent) had little or no response to chemotherapy (grade I) and sixteen (22 per cent) had a moderate degree of necrosis (grade II). The histological response to preoperative chemotherapy (p = 0.0001), followed by the size of the tumor (p = 0.001), were the most important predictors of event-free survival. At five years, the rate of event-free survival was zero of fourteen patients who had had a grade-I response, six of sixteen who had had a grade-II response, and thirty-seven (84 per cent) of forty-four who had had a grade-III or IV response. The risk of local recurrence was most strongly associated with the operative margins; there were only four local recurrences (6 per cent) after sixty-seven resections with negative margins. Local recurrence may also have been influenced by the histological response and the use of local radiation. There were no local recurrences after operative treatment of six tumors that had been associated with pathological fracture. The histological response to preoperative chemotherapy and the size of the primary tumor are the most important clinical predictors of the outcome of operative treatment of non-metastatic Ewing sarcoma. These indicators should be used to identify patients who are at high risk for metastasis as such patients may be candidates for more intensive or novel therapies. 相似文献
194.
J Regnstr?m G Walldius S Nilsson LS Elinder J Johansson J M?lgaard I Holme AG Olsson J Nilsson 《Canadian Metallurgical Quarterly》1996,125(2):217-229
Our knowledge of the traits possessed by extraintestinal isolates of Escherichia coli, necessary for growth and survival in urine, is limited. To identify such determinants, transposon (TnphoA'1,4) mutant libraries of a clinical isolate (CP9) were generated and screened for derivatives exhibiting decreased growth in urine in vitro, and for mutants with active lacZ fusions that were induced in urine relative to laboratory medium. Using this approach we identified two genes, guaA (CPA24) and argC (CPI-1), which were previously unrecognized as being important for growth in human urine. Unexpectedly, not only does CPA24 (guaA) not grow in human urine in vitro, but it is sensitive to its effects, undergoing a 2-3 log loss of viability over 6 h. By contrast, CPA24 neither grows nor is killed in M9 minimal medium and artificial urine. Therefore, we postulate that lack of guanine or its derivatives in urine, and the inability of CPA24 to synthesize these compounds de novo, prevents CPA24 from synthesizing other guanine (or derivatives)-dependent products that are critical for growth and survival in urine. Although it seems logical that decreased growth in urine in vitro should correlate with diminished urovirulence, this concept was tested by challenging mice with CPA24 in vivo in a mouse model of urinary tract infection (UTI). Indeed, CPA24 was found to be significantly less virulent compared with its wild-type parent CP9. CPI-1(argC) was identified because of the significant induction of its argC::lacZ fusion in urine. Subsequent testing in urine demonstrated that its growth was significantly diminished in all urine samples tested (four females, three males). Polyamine synthesis is dependent upon, in part, the arginine biosynthetic pathway. Therefore, we tested whether the induction of argC in urine and/or the decreased growth of CPI-1 was a result of low levels of polyamines or arginine in urine. The results suggest that low levels of arginine, but not polyamines, in human urine are responsible. When tested in vivo in the mouse model of UTI, CPI-1 was also found to be significantly less virulent than CP9. In summary, we have established that guaA and argC are the first genes, which we are aware of, that have been shown to contribute to the growth of E. coli in urine in vitro and both have diminished urovirulence in vivo. These results support the concept that urine can be used in vitro as a screening tool to identify urovirulence traits. 相似文献
195.
G Liuzzo A Buffon LM Biasucci JR Gallimore G Caligiuri A Vitelli S Altamura G Ciliberto AG Rebuzzi F Crea MB Pepys A Maseri 《Canadian Metallurgical Quarterly》1998,98(22):2370-2376
BACKGROUND: Systemic markers of inflammation have been found in unstable angina. Disruption of culprit coronary stenoses may cause a greater inflammatory response in patients with unstable than those with stable angina. We assessed the time course of C-reactive protein (CRP), serum amyloid A protein (SAA), and interleukin-6 (IL-6) after single-vessel PTCA in 30 patients with stable and 56 patients with unstable angina (protocol A). We also studied 12 patients with stable and 15 with unstable angina after diagnostic coronary angiography (protocol B). METHODS AND RESULTS: Peripheral blood samples were taken before and 6, 24, 48, and 72 hours after PTCA or angiography. In protocol A, baseline CRP, SAA, and IL-6 levels were normal in 87% of stable and 29% of unstable patients. After PTCA, CRP, SAA, and IL-6 did not change in stable patients and unstable patients with normal baseline levels but increased in unstable patients with raised baseline levels (all P<0.001). In protocol B, CRP, SAA, and IL-6 did not change in stable angina patients after angiography but increased in unstable angina patients (all P<0.05). Baseline CRP and SAA levels correlated with their peak values after PTCA and angiography (all P<0.001). CONCLUSIONS: Our data suggest that plaque rupture per se is not the main cause of the acute-phase protein increase in unstable angina and that increased baseline levels of acute-phase proteins are a marker of the hyperresponsiveness of the inflammatory system even to small stimuli. Thus, an enhanced inflammatory response to nonspecific stimuli may be involved in the pathogenesis of unstable angina. 相似文献
196.
197.
DA Edwards DJ Henderson-Smart AG Pettigrew A Wetzlar AF Phippard 《Canadian Metallurgical Quarterly》1994,82(1-2):181-184
Brainstem auditory evoked responses were recorded longitudinally from 11 neonatal baboons (Papio hamadryas), 6 of which were preterm. Recordings were made in unsedated animals from day 161 to day 362 after conception (term = 182 days). The pattern of development of both waveform morphology and of wave latency was consistent with that seen in the human neonate, with a rapid maturation of the response during the perinatal period, and then a slower development to adult values. Brainstem conduction time was measured from the wave I to wave IV interval, and this demonstrated a similar pattern, with a rapid decrease in latency up to term, and then decreasing more slowly to reach adult values by 4 months of age in the baboon. 相似文献
198.
TJ Brazil AG Rossi C Haslett B McGorum PM Dixon ER Chilvers 《Canadian Metallurgical Quarterly》1998,63(3):380-388
The synthetic formylpeptide fMLP is widely used as a model chemoattractant and secretagogue for mammalian neutrophils. Despite possessing fMLP receptors, equine neutrophils do not produce superoxide anions in response to fMLP and there is no inflammatory reaction in the horse when fMLP is injected intradermally. The functional capability of these receptors was investigated after pretreatment with recognized priming agents. Purified neutrophils were pretreated with lipopolysaccharide (LPS), platelet-activating factor (PAF), or tumor necrosis factor alpha (TNF-alpha) and superoxide anion generation and shape change quantified by lucigenin-dependent chemiluminescence (LDCL) and flow cytometry, respectively. LPS, TNF-alpha, and PAF pretreatment induced significant LDCL in response to fMLP; similarly LPS pretreatment was a prerequisite for fMLP-stimulated neutrophil polarization in response to fMLP. However, LPS failed to induce fMLP-mediated chemotaxis of equine neutrophils. These data indicate that equine neutrophil fMLP receptors are not vestigial as previously thought but can trigger both respiratory burst activity and cell polarization responses after priming. 相似文献
199.
A local circuit approach to understanding integration of long-range inputs in primary visual cortex 总被引:1,自引:0,他引:1
DC Somers EV Todorov AG Siapas LJ Toth DS Kim M Sur 《Canadian Metallurgical Quarterly》1998,8(3):204-217
Integration of inputs by cortical neurons provides the basis for the complex information processing performed in the cerebral cortex. Here, we have examined how primary visual cortical neurons integrate classical and nonclassical receptive field inputs. The effect of nonclassical receptive field stimuli and, correspondingly, of long-range intracortical inputs is known to be context-dependent: the same long-range stimulus can either facilitate or suppress responses, depending on the level of local activation. By constructing a large-scale model of primary visual cortex, we demonstrate that this effect can be understood in terms of the local cortical circuitry. Each receptive field position contributes both excitatory and inhibitory inputs; however, the inhibitory inputs have greater influence when overall receptive field drive is greater. This mechanism also explains contrast-dependent modulations within the classical receptive field, which similarly switch between excitatory and inhibitory. In order to simplify analysis and to explain the fundamental mechanisms of the model, self-contained modules that capture nonlinear local circuit interactions are constructed. This work supports the notion that receptive field integration is the result of local processing within small groups of neurons rather than in single neurons. 相似文献
200.
In this study, activated carbon cloths (ACCs) were modified in a glow-discharge apparatus by using 2-hydroxyethyl-methacrylate (HEMA), dimethyl-aminoethyl methacrylate (DMAEMA), and hydroxymethyldisiloxane (HMDS) plasmas. Scanning electron micrographs exhibited the formation of the polymeric films on the ACCs after glow-discharge modification. The adsorption experiments were performed using model solutes, i.e., creatinine, vitamin B-12, and trypsin. No significant change was observed in the adsorption capacities of the ACC/PHEMA and ACC/PDMAEMA composites compared with the original ACC adsorption capacity. However, there was a pronounced decrease in the case of the ACC/PHMDS. Oxygen permeabilities of both the original and modified ACCs were measured in a flow-through gas chamber. The oxygen permeabilities of the original and modified forms were 817 and 3.5-5 cm3/s.cm2.cm Hg x 10(-7), respectively. Water-vapor permeabilities of the composites were obtained by using a standard water-cup assembly. Permeabilities varying between 921 and 10,300 g/m2.day were found. Microorganism impermeabilities of the ACCs were demonstrated by using model PS monosize polymeric particles with a diameter of 0.2 micron. The particle permeability of the original ACC was 65.6 mg/m2.day. Almost no particle permission was observed through the modified ACCs. 相似文献