On‐the‐Spot Immobilization of Quantum Dots,Graphene Oxide,and Proteins via Hydrophobins

Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications.     

Efficacy and pharmacokinetics of gallopamil in patients with coronary artery disease

We prospectively studied 10 patients with stable exertional ischaemia, selected from a larger group of patients referred for suspected coronary artery disease or to detect residual ischaemia after myocardial infarction, to evaluate pharmacokinetic changes during chronic treatment with gallopamil and its correlation with clinical efficacy in patients with coronary artery disease. Our study consisted of a 1-week run-in single-blind placebo treatment and a 4-week single-blind gallopamil treatment. At the end of the run-in period patients underwent two different exercise tests, the first 2 hours and the second 7 hours after placebo administration. During active treatment all patients underwent two different exercise tests, the first 2 hours and the second 7 hours after gallopamil (50 mg) administration on the 1st and 28th days of gallopamil therapy. On the same days in eight of the patients we evaluated gallopamil pharmacokinetic changes. Our data revealed a rapid increase of unchanged gallopamil and its metabolite (norgallopamil) in the plasma, and a peak concentration of these substances about 2 hour after oral administration on both the 1st and 28th day of observation. Moreover, our results demonstrated an increase between the first and 28th day of treatment in peak concentration of unchanged gallopamil in the plasma, and of AUC 0-infinity and AUC o-c values during chronic treatment with gallopamil. Our clinical data showed an improvement in exercise results during gallopamil therapy related to increased concentration of the drug.     

Growth hormone and heart performance. A novel mechanism of cardiac wall stress regulation in humans

OBJECTIVES: This study was designed to assess systolic wall stress and ventricular function in patients with deranged growth hormone secretion, in an attempt to elucidate the mechanisms of growth hormone interaction with heart performance. DESIGN: A case-control study. SUBJECTS: Thirty patients with active acromegaly, free of diabetes mellitus and coronary artery disease, and 25 subjects with congenital growth hormone deficiency were studied. Twelve growth hormone-deficient subjects were reevaluated after 12 months of recombinant human growth hormone therapy. Two groups of 30 normal subjects each were used as controls for the acromegalic and growth hormone-deficient patients, respectively. RESULTS: In the acromegalics, end-systolic wall stress was reduced (-20%; P < 0.01) due to ventricular wall thickening (+ 26%; P < 0.001), whereas cardiac output was significantly increased (+ 20%; P < 0.01). The velocity of fibre shortening was unchanged. In growth hormone-deficient subjects, end-systolic wall stress was markedly increased (+ 38%; P < 0.001) due to a significant reduction of ventricular wall thickness (- 28%; P < 0.001), whereas cardiac output was significantly decreased (-44%; P < 0.001). Replacement therapy with recombinant human growth hormone produced a partial correction of wall thickness and stress. Consequently, systolic performance and cardiac output improved significantly. CONCLUSION: This study demonstrates that growth hormone plays a role in the control of cardiac wall stress and performance through a mechanism mediated by the effect of growth hormone on myocardial tissue growth. The data may have therapeutic implications in cardiac diseases that lead to heart failure.     

Prediction of efficacy of octreotide therapy in patients with acromegaly

Octreotide (OCT) administration provides a biochemical cure in most acromegalic patients. This drug, however, causes several side effects and is very expensive. Acute testing has been reported to predict chronic responsiveness to OCT administration. The aim of this retrospective study was to evaluate which test, if any, among acute testing, short-term (1 month) administration, and 111In-pentetreotide (111In-DTPA-Phe-D-OCT) scintigraphy, is best in predicting response to long-term OCT treatment. Sixty-eight patients with active acromegaly were studied. An acute test (100 micrograms sc OCT) was performed as usual: a GH decrease greater than or equal to 50% of baseline was considered a positive response. GH and insulin-like growth factor I (IGF-I) were then assayed after 1 month (300 micrograms daily) and 3 months (150-600 micrograms daily) of OCT administration. GH was considered normalized when decreased less than or equal to 5 micrograms/L. Twenty-six of 68 patients were subjected to 111In-pentetreotide scintigraphy. Linear correlation analysis of the results was performed. Sensitivity, specificity, and positive and negative predictive values of the three tests were also calculated. Thirty-eight of 68 patients (56%) responded to the acute test. Among these 38 patients, 20 experienced normalization of GH and IGF-I levels during long-term therapy, as did 8 patients who did not respond to the acute test. No significant correlation was found between GH percent decrease during acute testing and long-term therapy (r = 0.11). Seven patients who responded to the acute test and 2 who did not respond had adenoma shrinkage during therapy. Conversely, GH and IGF-I decrease after short-term treatment significantly correlated with long-term treatment (r = 0.76 and 0.64, P < 0.01). Of the 26 patients subjected to 111In-pentetreotide scintigraphy, 13 had significant tracer uptake: normalization of GH and IGF-I was obtained in 8 patients. A significant correlation was found between tracer uptake and GH/IGF-I inhibition after 3 months of therapy (r = 0.6; P < 0.05). In the whole population, the positive predictive value of acute testing, short-term OCT administration, and 111In-penetreotide scintigraphy was 53%, 70%, and 73%, respectively, when the GH normalization (< 5 micrograms/L) after 3 months of therapy was considered. Moreover, 111-In-pentetreotide scintigraphy had the highest specificity (100% in patients with baseline GH values below 50 micrograms/L) compared with that of acute testing and short-term OCT administration. The acute test cannot be considered as a valuable index to identify patients' responsiveness to long-term OCT therapy, but it can be useful to test tolerability. By contrast, 1 month of OCT administration or the in vivo imaging of somatostatin receptors by 111-In-pentetreotide might better indicate the patients who might effectively benefit from this treatment.     

Synthesis and pharmacological activity of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones

The synthesis of some N,N-disubstituted 1-amino-2-phenyl-3H,12H-naphtho[1,2-b]pyrano[2,3-d]pyran-3-ones 4, by reaction of phenylchloroketene with a series of N,N-disubstituted 3-aminomethylene-2,3-dihydro-4H-naphtho[1,2-b]pyran-4-ones, followed by dehydrochlorination in situ of the primary adducts with DBN, is described. Some compounds 4 showed antiarrhythmic and analgesic activities.     

Scanning electrochemical microscopy of the photosynthetic reaction center of Rhodobacter sphaeroides in different environmental systems

The present work uses a scanning electrochemical microscopy technique to study systems containing the membrane-bound reaction center protein (RC) from the purple photosynthetic bacteria Rhodobacter spheroides to chromatophores (spherical reorganization of cell membrane following its mechanical rupture) and liposomes (reconstituted membrane systems at lower degree of complexity). Scanning electrochemical microscopy is a useful tool to investigate redox processes involving a RC, because the effective heterogeneous rate constants for the redox reaction with different mediators can be measured. The technique is also able to provide information on the role of the outer cell membrane permeation on the kinetics of the electron-transfer processes and to obtain more insight into the nature of the species involved.     

适用于汽车无线电系统AM和FM波段的低噪声开关电源

引言随着汽车启停技术(引擎空闲时自动关闭)应用的日益广泛,越来越多的汽车系统必须工作在低输入电压。热启动(此时电池电压可下降达6V)和冷启动(此时电池电压可下降达3V)期间,会发生此类低输入电压。本文介绍可承受汽车全输入电压范围(包括冷启动和抛负载条件)的中间电压8V开关电源。电源保证为常见子系统提供稳定的8V电源,例如CD驱动器、LCD,以及现代信息娱乐系统中的无线电模块。为避免AM和FM波段干扰,开关电源工作在2MHz固定频率,成为无线电系统的理想方案。     

Characterisation of the geographical origin of Western Greek virgin olive oils based on instrumental and multivariate statistical analysis

In this work, measurements of free acidity, peroxide content, spectrophotometric parameters, chlorophyll content, phenol, sterol, fatty acid and triacylglycerol composition, were carried out on samples of virgin olive oils (VOOs) coming from four different Greek Ionian islands, i.e. Zakynthos, Kefalonia, Lefkada and Kerkyra. An analysis of variance (ANOVA) highlighted statistically significant differences (p < 0.01) in the values of 26 analytical parameters amongst the VOOs produced in the four different geographical regions but a post-hoc test showed that no variable was able to distinguish all four origins. Analogously, a Principal Component Analysis (PCA) showed a modest grouping of VOOs according to geographical origin except for Kerkyra samples which were more distinct from others. Applying discriminant function analysis (DFA) a good separation of the four geographical groups was achieved with classification and prediction abilities equal to 97.7% and 95.3%, respectively. Moreover, the analysis of the standardised coefficients showed that the fatty acids and triacylglycerols were the most discriminant variables. This last outcome was confirmed by comparison of the prediction performances obtained applying DFA on four subdatasets containing fatty acids (69.8%), triacylglycerols (76.7%), sterols (62.8%), and remaining parameters (65.1%) together, respectively. As the results showed, the multidisciplinary approach that combines different types of analytical determinations improved the discrimination of geographical origin for Greek virgin olive oils.