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排序方式: 共有344条查询结果,搜索用时 9 毫秒
91.
92.
JA Moshier MG Mutchnick J Dosescu TK Holtz S Akkary K Mahakala JR Merline PH Naylor 《Canadian Metallurgical Quarterly》1996,25(6):814-820
BACKGROUND: Thymosin-alpha 1 is a biological response modifier that has been used clinically, alone and in combination with interferon-alpha for the treatment of chronic hepatitis B viral infection. Both immunomodulatory and immediate intracellular mechanisms have been postulated to explain the effect of these two agents on HBV-infected hepatocytes. METHODS: In this study, hepatitis B transfected HepG2 hepatoblastoma cells (HepG2-Nu2), derived from 2.2.15 cells, were used as an in vitro model to determine the efficacy of thymosin-alpha 1 and interferon-alpha, individually and combined, as proliferation inhibitors of HBV-infected cells. For comparison, parental HepG2 cells and an SV40-transfected HepG2 cell line (HepG2P9T2) were also evaluated. RESULTS: In a clonogenic soft agar assay, thymosin-alpha 1 inhibited the anchorage-independent growth of the HepG2-Nu2 cells by 40% compared with untreated controls, but did not inhibit parental HepG2 or HepG2P9T2 clonal growth. The response was dose dependent over concentrations spanning three log units. In comparison, 10000 units/ml of interferon-alpha inhibited parental HepG2, HepG2-N4Z and HepG2P9T2 by 33%, 41% and 87%, respectively. The combination of thymosin-alpha 1 and interferon-alpha consistently inhibited HepG2-Nu2 clonal growth more effectively than either treatment alone, reaching maximum inhibition levels of 51%. CONCLUSIONS: Thymosin-alpha 1 specifically inhibits the tumorigenic growth of HBV-transfected HepG2 cells in contrast to the general inhibition displayed by interferon-alpha. This panel of cell lines may be an important resource for dissecting the mechanism by which thymosin, alone or in combination with other drugs, influences HBV-infected hepatocytes and/or HBV-associated carcinoma. 相似文献
93.
94.
Tooley F. Firth W. Walker A. MacKenzie H. Reid J. Smith S. 《Quantum Electronics, IEEE Journal of》1985,21(9):1356-1362
We report measurements on the frequency dependence of transphasor gain using an indium antimonide etalon. Experimental results and a theoretical model indicate that the product of bandwidth and low frequency gain is approximately constant and that this constant is determined by the recombination rate of free carriers. The results should be generally applicable to devices of this type. 相似文献
95.
D Walmsley CJ Inglefield AR Naylor LE Murchison PS Kolhe GG Cooper 《Canadian Metallurgical Quarterly》1996,13(3):281-283
Loco-regional recurrence following resection of squamous cell carcinoma of the upper aero-digestive tract is a major problem. Cells exfoliated from malignant tumours have been considered capable of implanting and giving rise to local recurrence or metastatic deposits. A prospective study was performed examining washings from the gloves and instruments used in major head and neck operations to determine if exfoliated cells were indeed present. Following removal of the main tumour specimen all surgeons washed their hands in a solution containing a cell fixative and all instruments were soaked in the solution. Samples were then centrifuged and stained using a modified PAP technique. On occasions nuclear fragments consistent with squamous cell carcinoma were present in both glove and instrument washings. We recommend that all surgeons change gloves and instruments following removal of the main tumour specimen and prior to irrigation of the operative field with a tumoricidal agent. 相似文献
96.
97.
Consideration is given to the characterization and origins of mold fouling occurring during the injection molding of elastomers. Results for nitrile rubber and fluoroelastomer compounds are presented with a range of techniques, including light microscopy, scanning electron microscopy, elemental analysis by energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy, and surface‐energy measurements with the sessile drop approach. A specially designed mold tool combined with interchangeable cavity inserts has also enabled the exploration of the effects of different metal surface treatments on the onset and extent of mold fouling. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3186–3194, 2006 相似文献
98.
Alkylphenol ethoxylates in the environment 总被引:21,自引:0,他引:21
Carter G. Naylor James P. Mieure William J. Adams John A. Weeks Frank J. Castaldi Larry D. Ogle Robert R. Romano 《Journal of the American Oil Chemists' Society》1992,69(7):695-703
A comprehensive monitoring study, sponsored by the Chemical Manufacturers Association and designed in cooperation with the
Environmental Protection Agency (EPA), measured the levels of nonylphenol (NP) and its ethoxylates (NPE) in 30 rivers. The
sites, all receiving municipal or industrial wastewater, were selected at random from EPA’s United States river reach database
by a statistical procedure. Water column and bottom sediment samples were collected along a perpendicular transect at each
site. All samples were assayed for NP and NPE1, and the higher ethoxylates (NPE2 to NPE17) were determined in the water samples. Analysis was by high-performance liquid chromatography (HPLC) with fluorescence detection
of microgram quantities of NPE obtained by extractive steam distillation (NP and NPE1) or a dualcolumn extraction procedure (NPE2 to NPE17). Sample collection and analytical procedures were validated according to rigorous EPA guidelines, and quality assurance
standards were met throughout the study. NP and NPE concentrations in river water were mostly (60 to 75% of the samples) below
their detection limits (about 0.1 ppb for NP, NPE1, and NPE2; 1.6 ppb for NPE3–17). The highest levels found were about 1 ppb for NP, NPE1, and NPE2, 15 ppb for NPE3–17. A majority of sediment samples contained detectable amounts of NP and NPE1, ranging up to 3000 ppb for NP and 170 ppb for NPE1. Sediment interstitial water concentrations of NP were estimated to be similar to concentrations in the water column.
A portion of this paper was presented at the 1991 Annual AOCS Meeting in Chicago 相似文献
99.
Georgiana Neag Melissa Finlay Amy J. Naylor 《International journal of molecular sciences》2021,22(14)
Interaction between endothelial cells and osteoblasts is essential for bone development and homeostasis. This process is mediated in large part by osteoblast angiotropism, the migration of osteoblasts alongside blood vessels, which is crucial for the homing of osteoblasts to sites of bone formation during embryogenesis and in mature bones during remodeling and repair. Specialized bone endothelial cells that form “type H” capillaries have emerged as key interaction partners of osteoblasts, regulating osteoblast differentiation and maturation and ensuring their migration towards newly forming trabecular bone areas. Recent revolutions in high-resolution imaging methodologies for bone as well as single cell and RNA sequencing technologies have enabled the identification of some of the signaling pathways and molecular interactions that underpin this regulatory relationship. Similarly, the intercellular cross talk between endothelial cells and entombed osteocytes that is essential for bone formation, repair, and maintenance are beginning to be uncovered. This is a relatively new area of research that has, until recently, been hampered by a lack of appropriate analysis tools. Now that these tools are available, greater understanding of the molecular relationships between these key cell types is expected to facilitate identification of new drug targets for diseases of bone formation and remodeling. 相似文献
100.
The V-I characteristics of a 3He-cooled, composite bolometer detector designed for submillimetre astronomy are modelled. The modelling yields detector parameters that cannot be measured directly. The system NEP predicted from theoretical V-I equations is found to agree with the measured noise values. The calculated dynamic thermal conductance and the electrical responsivity are found to deviate from the standard model at low temperatures. 相似文献