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31.
A. F. G. Wyatt I. N. Adamenko K. E. Nemchenko 《Journal of Low Temperature Physics》2002,126(1-2):609-614
We calculate the energy density of high energy phonons created from a pulse of low energy phonons spatially confined to a narrow cone. We include the tangential expansion of the propagating pulse and the interactions between high energy phonons within the pulse as well with low energy phonons. The expansion of the pulse causes it to cool so much that the creation of high energy phonons stops within 3 mm of the heater. The decay rate of high energy phonons governs the dynamic equilibrium inside the pulse. The magnitude of the high energy phonons, emitted by the pulse into the cold liquid helium, is calculated for different length pulses. It is found that small heaters can produce short pulses of high energy phonons from relatively long injected pulses. 相似文献
32.
W Weder RA Schmid H Bruchhaus S Hillinger GK von Schulthess HC Steinert 《Canadian Metallurgical Quarterly》1998,66(3):886-92; discussion 892-3
BACKGROUND: Accurate staging of non-small cell lung cancer is essential for treatment planning. We evaluated in a prospective study the role of whole-body 2-[18F]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) in mediastinal nodal staging with a positive predictive value of 96%. The study was continued to further evaluate the value of whole-body FDG PET in detecting unexpected extrathoracic metastases (ETMs) in patients qualifying for surgical treatment by conventional staging. METHODS: One hundred patients underwent clinical evaluation, chest and upper abdominal computed tomography scan, mediastinoscopy (lymph nodes greater than 1 cm on computed tomography), and routine laboratory tests. In 94 patients with stage IIIa or less and 6 with suspected N3 a whole-body FDG PET was performed. If clinical signs of ETMs were present additional diagnostic methods were applied. All findings in the FDG PET were confirmed histologically or radiologically. RESULTS: Unexpected ETMs were detected in 13 (14%) of 94 patients (stage IIIa or less) at 14 sites. In addition 6 of 94 patients were restaged up to N3 after PET. The suspected N3 disease (stage IIIb) on computed tomography was confirmed by PET in all 6 patients. There was no false positive finding of ETM. Weight loss was correlated with the occurrence of ETM: more than 5 kg, 5 of 13 patients (38%); more than 10 kg, 4 of 6 patients (67%). Pathologic laboratory findings were not predictive for ETM. CONCLUSIONS: Whole-body FDG PET improves detection of ETMs in patients with non-small cell lung cancer otherwise elegible for operation. In 14% of patients (stage IIIa or less), ETMs were detected, and in total, 20% of the patients were understaged. 相似文献
33.
34.
GB Karlsson M Halloran D Schenten J Lee P Racz K Tenner-Racz J Manola R Gelman B Etemad-Moghadam E Desjardins R Wyatt NP Gerard L Marcon D Margolin J Fanton MK Axthelm NL Letvin J Sodroski 《Canadian Metallurgical Quarterly》1998,188(6):1159-1171
CD4+ T lymphocyte depletion in human immunodeficiency virus type 1 (HIV-1)-infected humans underlies the development of acquired immune deficiency syndrome. Using a model in which rhesus macaques were infected with chimeric simian-human immunodeficiency viruses (SHIVs), we show that both the level of viremia and the structure of the HIV-1 envelope glycoprotein ectodomains individually contributed to the efficiency with which CD4(+) T lymphocytes were depleted. The envelope glycoproteins of recombinant SHIVs that efficiently caused loss of CD4(+) T lymphocytes exhibited increased chemokine receptor binding and membrane-fusing capacity compared with those of less pathogenic viruses. These studies identify the HIV-1 envelope glycoprotein ectodomains as determinants of CD4(+) T lymphocyte loss in vivo and provide a foundation for studying pathogenic mechanisms. 相似文献
35.
A 29-year-old man was admitted to the hospital because of a high fever and dyspnea. He had a history of bronchial asthma and had had a bullectomy of the right lung at 15 years of age. He had visited a family physician because of fever and non productive coughing. Medications had no effect on his symptoms, and dyspnea developed. A chest X-ray film showed total collapse of the right lung, and he was referred to our hospital. Laboratory data showed eosinophilia and a high titer of IgE. Total obstruction of the right main stem bronchus by mucous plug was found during fiberoptic bronchoscopy. Aspergillus was detected by pathological examination of bronchial lavage fluid. Tests for aspergillus-specific IgE and IgG antibody were positive, as was immediate skin reactivity to Aspergillus. Allergic bronchopulmonary aspergillosis (ABPA) was diagnosed. Infusion and inhalation of a corticosteroid and fluconazole were effective; the symptoms resolved and X-ray findings improved. While migratory infiltration, proximal bronchiectasis and segmental or subsegmental atelectasis caused by a mucous plug are common X-ray findings in allergic bronchopulmonary aspergillosis, total collapse is rare. 相似文献
36.
37.
Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase implicated in cell-matrix interaction and integrin signaling. It is well established that Tyr-397 is the FAK autophosphorylation site and Tyr-407, -576/577, -861, and -925 are the sites on murine FAK that are mediated by Src family kinases. To study how FAK is regulated by tyrosine phosphatase(s), cells overexpressing chicken FAK are treated with sodium vanadate. Both the phosphotyrosine content and the enzymatic activity of FAK are increased in response to vanadate. Interestingly, sustained FAK Tyr-576/577 and -863 phosphorylations are detected in vanadate-treated FAK overexpressors and are dependent on FAK autophosphorylation. Further analysis of sodium vanadate-treated FAK overexpressors reveals that the enhanced FAK kinase activity parallels its elevated Tyr-576/577 phosphorylation. Thus, we conclude that Src-mediated FAK phosphorylation is regulated by a tyrosine phosphatase(s) and may be of physioligical significance. 相似文献
38.
G Velikova RE Banks A Gearing I Hemingway MA Forbes SR Preston NR Hall M Jones J Wyatt K Miller U Ward J Al-Maskatti SM Singh PJ Finan NS Ambrose JN Primrose PJ Selby 《Canadian Metallurgical Quarterly》1998,77(11):1857-1863
The concentrations of the soluble adhesion molecules E-cadherin, E-selectin, intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were investigated in 48 patients with colorectal cancer before treatment, and their relation to clinical, histological and routine laboratory parameters was examined. Data were collected on tumour stage at presentation, presence and sites of metastatic disease, tumour pathology and results of routine laboratory tests. Serum concentrations of ICAM-1 and VCAM-1 were significantly elevated in the patients with colorectal cancer in comparison with a group of healthy subjects (P < 0.00001). Levels of circulating ICAM-1 and VCAM-1 were increased both in patients with local and those with metastatic disease. Although elevated in some patients soluble E-cadherin and E-selectin concentrations were not significantly elevated compared with the control group (P = 0.71 and P = 0.052 respectively). The levels of circulating ICAM-1 were significantly correlated with those of VCAM-1 and E-selectin. A correlation was also found between the serum concentrations of E-selectin and ICAM-1 and alkaline phosphatase, total white cell count and platelet count. VCAM-1 was positively correlated with age and negatively with degree of tumour differentiation and haemoglobin concentration. The biological implications and possible clinical relevance of these findings are discussed. 相似文献
39.
A Seth I Ourmanov MJ Kuroda JE Schmitz MW Carroll LS Wyatt B Moss MA Forman VM Hirsch NL Letvin 《Canadian Metallurgical Quarterly》1998,95(17):10112-10116
The utility of modified vaccinia virus Ankara (MVA) as a vector for eliciting AIDS virus-specific cytotoxic T lymphocytes (CTL) was explored in the simian immunodeficiency virus (SIV)/rhesus monkey model. After two intramuscular immunizations with recombinant MVA-SIVSM gag pol, the monkeys developed a Gag epitope-specific CTL response readily detected in peripheral blood lymphocytes by using a functional killing assay. Moreover, those immunizations also elicited a population of CD8+ T lymphocytes in the peripheral blood that bound a specific major histocompatibility complex class I/peptide tetramer. These Gag epitope-specific CD8+ T lymphocytes also were demonstrated by using both functional and tetramer-binding assays in lymph nodes of the immunized monkeys. These observations suggest that MVA may prove a useful vector for an HIV-1 vaccine. They also suggest that tetramer staining may be a useful technology for monitoring CTL generation in vaccine trials in nonhuman primates and in humans. 相似文献
40.
K. R. Price Jenny Lewis G. M. Wyatt G. R. Fenwick 《Molecular nutrition & food research》1988,32(6):609-626
In addition to causing embarassment and unease, flatulence is linked to a variety of symptoms, some of which may be distressing. This review describes the origins of intestinal gas, its composition and methods which have been developed for its analysis. Emphasis is placed upon the effects of legumes in the diet in producing excessive intestinal gas and, particularly, on the role of raffinose-type oligosaccharides, containing α-galactosidic groupings. Suggestions for overcoming the problem are presented, including drug treatment, enzyme treatment, food processing and plant breeding. It is emphasised that removal of all raffinose-oligosaccharides from beans does not remove the problem of flatulence in animals and man; the compounds responsible — though assumed to be polysaccharides (or polysaccharide-derived oligomers formed by processing or cooking) — have yet to be characterised. 相似文献