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Brian Giambattista W. W. McNairy C. G. Slough A. Johnson L. D. Bell R. V. Coleman J. Schneir R. Sonnenfeld B. Drake P. K. Hansma 《Proceedings of the National Academy of Sciences of the United States of America》1987,84(14):4671-4674
A scanning tunneling microscope (STM) can provide atomic-resolution images of solids covered with a variety of liquids, including cryogenic fluids, both polar and nonpolar solvents, conductive aqueous solutions, oils, and even greases. This short overview includes images of solids covered with liquid nitrogen, liquid helium, paraffin oil, silicone oil, microscope immersion oil, silicone vacuum grease, fluorocarbon grease, glycerol, and salt water. These images show atoms, charge-density waves, grains in an evaporated metal film, and even corrosion processes as they occur in real time. The future includes not only basic research in surface science but also applied research in lithography, lubrication, catalysis, corrosion, electrochemistry, and perhaps even biology. 相似文献
3.
Synergistic antiproliferative activity of quercetin and cisplatin on ovarian cancer cell growth 总被引:1,自引:0,他引:1
G Scambia F O Ranelletti P Benedetti Panici G Bonanno R De Vincenzo M Piantelli S Mancuso 《Anti-cancer drugs》1990,1(1):45-48
It has been demonstrated that the flavonoid quercetin (3,3',4',5-7-pentahydroxyflavone) (Q) inhibits the growth of several cancer cell lines and that the antiproliferative activity of this substance is mediated by a so-called type II estrogen binding site (type II EBS). We investigated the effects of quercetin and cisplatin (CDDP) alone and in combination on the proliferation of the ovarian cancer cell line OVCA 433. Both drugs exhibited a dose-related growth inhibition in a range of concentrations between 0.01 and 2.5 microM and 0.01 and 2.5 micrograms/ml for Q and CDDP respectively. The combination of the two drugs resulted in a synergistic antiproliferative activity. Two other flavonoids tested, i.e., rutin (3-rhamnosylglucoside of quercetin) and hesperidin [7-b rutinoside of hesperetin (3'-5-3-hydroxy-4-methoxyflavone)] were ineffective both alone and in combination with CDDP. Since both rutin and hesperidin do not bind to type II EBS it can be hypothesized that Q synergizes with CDDP by acting through an interaction with these binding sites. 相似文献
4.
A M Vignola A Bonanno M Profita L Riccobono N Scichilone M Spatafora J Bousquet G Bonsignore V Bellia 《The European respiratory journal》2003,22(5):795-801
In asthmatic subjects an imbalance between elastase and alpha1-antitrypsin (alpha1-PI) exists. This study aims to evaluate whether ageing per se affects the levels of elastase. Both young and elderly asthmatics with comparable severity and duration of disease, as well as young and elderly healthy subjects, underwent an induced sputum procedure to measure levels of elastase and alpha1-PI. The percentage of sputum neutrophils and eosinophils was higher in young and elderly asthmatics than in young and elderly controls. The levels of both total and active elastase were significantly higher in young and elderly asthmatics than in young and elderly controls, and directly correlated with the percentage of neutrophils. In addition, in both young and elderly asthmatics the levels of total and active elastase were negatively correlated with forced expiratory volume in one second values, but positively correlated with the duration of the disease. This study indicates that ageing per se does not necessarily lead to a progressive elastase/alpha1-antitrypsin imbalance in asthma, and suggests that an important variable in the development of airway remodelling in both young and elderly asthmatics is represented by the duration of the disease. 相似文献
5.
Effect of rigid contact lens oxygen transmissibility on stromal pH in the living human eye 总被引:1,自引:0,他引:1
Corneal stromal pH was measured fluorometrically in nine human subjects after 1.5 hours of eye closure while wearing hard gas permeable contact lenses. Six lens types providing a wide range in oxygen transmissibilities (Dk/L)O2 from 0.15 to 55.0 X 10(-9) (cm ml O2/seconds of ml mmHg) were used. Stromal pH upon opening the eyes was directly related to (Dk/L)O2 and ranged from 7.01 to 7.26. These pH values were all significantly lower than the control (no lens), which had a pH of 7.38 (P less than 0.005). After eye opening (lens still on) stromal pH increased and reached a new steady-state (range, 7.11-7.45) in approximately 30 minutes; however, these pH levels were still below the control (no lens) (pH 7.54; P less than 0.005). The rate of pH change after eye opening also increased directly with (Dk/L)O2. The authors conclude that the lenses presently available provide insufficient gas exchange to prevent alteration of corneal pH and suggest that the measurement of stromal pH may provide a sensitive index for evaluating the metabolic effects of contract lens wear. 相似文献
6.
A detailed comparison of intracellular pH (pHi) regulatory mechanisms was made between fresh (FBCE) and cultured (CBCE) bovine corneal endothelium to: (1) identify the ion transport mechanisms that could directly or indirectly affect transendothelial HCO3- transport; and (2) determine if cultured cells could serve as a model for studying transendothelial bicarbonate transport. We used the pH-sensitive fluorescent probe BCECF-AM to measure pHi. FBCE and CBCE readily incorporated the dye and showed pHi calibration curves that were not significantly different with respect to pK (7.39 for FBCE and 7.35 for CBCE). Resting pHi in bicarbonate free Ringer's (pH 7.5) was significantly lower in cultured cells (7.17 +/- .02, n = 50) than in fresh cells (7.30 +/- .02, n = 54). Steady-state pHi was reduced by addition of 0.5 mmol/l amiloride, a Na+/H+ exchange blocker (-.16 pH U for FBCE, -.18 for CBCE) or removal of Na+ (-.47 pH U for FBCE, -.51 for CBCE). Recovery from an (NH4)2SO4-induced acid load was blocked by Na+ removal, and the rate of recovery was inhibited 74% and 79% in the presence of amiloride for FBCE and CBCE, respectively. The dependence of proton efflux on Na+0 showed simple saturating kinetics (apparent Km = 30 and 31 mmol/l for FBCE and CBCE, respectively), consistent with the presence of Na+/H+ exchange in FBCE and CBCE. Na+/H+ exchange activity, as measured by amiloride-sensitive acid recovery, was inversely proportional to pHi. The activity in FBCE was about twice that in CBCE. Furthermore, the zero flux point for Na+/H+ exchange was at least 0.1 pH U higher in FBCE. Changing from bicarbonate-free Ringer's to bicarbonate Ringer's (5% CO2/28 mmol/l HCO3-, pH 7.5) induced a rapid and short acidification followed by an alkalinization .09 and .18 pH U above the starting pHi for FBCE (final pHi 7.37) and CBCE (final pHi 7.33), respectively. This transition was unaffected by amiloride. Similarly, amiloride had no effect on resting pHi in bicarbonate Ringer's for FBCE or CBCE, indicating that Na+/H+ exchange does not contribute to the maintenance of the steady-state resting pHi in bicarbonate Ringer's. Although most of the characteristics of Na+/H+ exchange for FBCE and CBCE were similar, the differences in overall activity and the low levels of activity in resting cells must be considered when using CBCE to model ion coupled fluid transport in BCE. 相似文献
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Pace E Profita M Melis M Bonanno A Paternò A Mody CH Spatafora M Ferraro M Siena L Vignola AM Bonsignore G Gjomarkaj M 《Clinical and experimental immunology》2004,135(3):519-527
The pleural space is a virtual compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells during a variety of respiratory diseases. Here, we study the potential role of the eicosanoid metabolite leukotriene B4 (LTB4) in disparate diseases leading to acute (pneumonia) or chronic (tuberculosis, cancer) inflammation of the pleural space. LTB4 concentrations were significantly higher in pleural fluid due to pneumonia, tuberculosis and cancer with respect to congestive heart failure and correlated with neutrophil elastase, which is used as an indication of state of activation of neutrophils in the pleural space. Moreover, pleural LTB4 was biologically active, as an anti-LTB4 antibody partially neutralized the chemotactic activity of parapneumonic, tuberculous and cancer effusions. Macrophages, neutrophils, lymphocytes, mesothelial cells and cancer cells all expressed mRNA for 5-lipoxygenase, the enzyme that initiates leukotriene synthesis leading to the production of LTB4, in exudative pleural effusions. Upon stimulation in transudative pleural effusions, pleural macrophages produced, in a time-dependent fashion, a significantly higher concentration of LTB4 than mesothelial cells. These studies demonstrate that different cell types are capable of producing LTB4 in the inflamed pleural space and that this mediator may play a crucial role in the recruitment of neutrophils into the pleural space. 相似文献
9.
Thirty-nine bereaved individuals completed the Continuing Bonds Scale (CBS), assessing various aspects of the ongoing attachment to the deceased, at 60 months postloss in a longitudinal conjugal bereavement study. They also completed symptom measures at 6, 14, 25, and 60 months postloss. Higher CBS scores were associated with a more elevated grief-specific symptom pattern over the 5-year postloss period. Moreover, those who expressed greater helplessness and less blame toward the deceased during a monologue role-play involving their deceased spouse at 6 months postloss had higher CBS scores. Finally, greater satisfaction in the past relationship with the spouse was predictive of higher CBS scores. The results were discussed in relation to existing literature on the adaptiveness of continuing bonds. 相似文献
10.
Reciprocal stimulation of gammadelta T cells and dendritic cells during the anti-mycobacterial immune response 总被引:2,自引:0,他引:2
Dieli F Caccamo N Meraviglia S Ivanyi J Sireci G Bonanno CT Ferlazzo V La Mendola C Salerno A 《European journal of immunology》2004,34(11):3227-3235
Gammadelta T cells and dendritic cells (DC) are two distinct cell types of innate immunity that participate in early phases of immune response against Mycobacterium tuberculosis infection. Here we show that a close functional relationship exists between these cell populations. Using an in vitro coculture system, Vgamma1 T cells from Tcrb(-/- )mice were found to be activated by DC infected in vitro with BCG, as indicated by the elevated CD69 expression, IFN-gamma secretion and cytotoxic activity. This activation process was due to a non-cognate mechanism since it required neither cell to cell contact nor interaction between the TCR and a specific antigen, but was mediated by DC-derived IL-12. Reciprocally, Vgamma1 T cells provided a key cytokine, IFN-gamma, which increased IL-12 production by BCG-infected DC. Moreover, exposure of BCG-infected DC to Vgamma1 T cells conditioned the former to prime a significantly stronger anti-mycobacterial CD8 T cell response. Consequently, stimulation of gammadelta T cells and their non-cognate interaction with DC could be applied as an immune adjuvant strategy to optimize vaccine-induced CD8 T cell immunity. 相似文献