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71.
The catalytic activity of the antibody H11 is shown to reside chiefly in its ability to hydrolyze 1-acetoxybutadiene to crotonaldehyde and to promote the cycloaddition of the intermediate enol with N-alkylmaleimides. This conclusion is based upon the demonstration that the enol tautomerizes too rapidly in solution to be a competent intermediate and that under the reaction conditions for H11, no cycloaddition occurs with crotonaldehyde and N-ethylmaleimide. As a first step towards a structural understanding of the chemistry of H11, chemical modification experiments have shown that reactions of acidic amino acids, tyrosine, lysine, and histidine, but not arginine, inhibit the reactions mediated by H11.  相似文献   
72.
SiO2 gel layers of different thickness have been deposited on glass sheets by dipping from gelling solutions with different concentrations of silicon alkoxide. Some mechanical properties of the coated samples such as hardness (H), elastic modulus (E), crack formation tendency, and tensile stress in the film (σ) have been measured by microindentation techniques and slide deflection. SiO2 films deposited from more dilute solutions had lower H, E, and σ values, accounting for the observed higher resistance to crack nucleation in comparison with that found for samples prepared from more concentrated solutions.  相似文献   
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74.
The diagnosis of water distribution systems by means of the inverse transient analysis requires efficient and reliable numerical models. In the network admittance matrix method (NAMM) the 1-D waterhammer governing equations are integrated in the frequency domain and organized in a laplacian matrix form. The NAMM is particularly suitable for complex systems because of this structure and can be used for the system diagnosis, including leak sizing and location. In this paper a damaged branched system is considered and the diagnosis is performed by means of the NAMM using experimental data from laboratory transient tests. Two different boundary conditions are used in the implementation of the NAMM and the leak is located and sized with a reasonable approximation. An extended numerical investigation is also presented and allows confirmation of the results for different leak locations. The use of the NAMM for the leak detection and the validation using experimental data on a branched system are the main original contributions of this work. The successful diagnosis indicates promising results for applications in more complex systems.  相似文献   
75.
Carbon xerogels, synthesized through the resorcinol–formaldehyde polycondensation and subsequently dried under subcritical condition, have been studied as electrodes for supercapacitors. In particular, the influence of the catalyst concentration has been investigated by systematically changing the amount of catalyst (Na2CO3) utilized to synthesize the xerogels. To clarify the effect of such variable, both the surface properties and the electrochemical behavior of xerogel-based supercapacitors have been examined. From the xerogels characterization, it can be inferred that the amount of catalyst used has a strong influence on the properties of the material. Contrary to what happens with carbon aerogels, the best properties are obtained with the xerogels synthesized with the least amount of catalyst: in this case the highest measured specific capacitance of the supercapacitor cells, which is assembled coupling two symmetric electrodes in series, is 25 F/g, value that corresponds to a single-electrode specific capacitance of 100 F/g. The maximum energy storage capacity in an aqueous electrolyte is 3.1 Wh/kg. Using more concentrated catalyst solutions, the gel microstructure becomes finer, composed of smaller particles and pores, which in turns leads to an increase of the capillary drying stresses and to the collapse of the organic structure. Consequently, the shrinkage of the gels is high and the final carbon xerogels do not posses sufficient surface area and porosity to store a significative amount of energy.  相似文献   
76.
Emissions related to wood production processes are a recognized health hazard for professionally exposed subjects. The health effects of living close to wood industries are not known, particularly in the pediatric population. We aimed at investigating if living close to chipboard industries is a health hazard for the children in the Viadana district (Northern Italy).In December 2006, all the children (3-14 years) living in the Viadana district, where two big chipboard industries are located, were surveyed through a parental questionnaire (n = 3854). The children were geocoded, and the distance of their houses/schools from the closest wood plant was computed.Independently of sex, age, nationality, residential area, traffic, parents' education, passive/parental smoking, questionnaire compiler and his/her environmental concern, the children living at < 2 km from chipboard industries had a greater prevalence of respiratory (OR = 1.33, 95%CI: 1.11, 1.60), cough/phlegm (OR = 1.43, 95%CI: 1.08, 1.88), nose/throat/mouth (OR = 1.47, 95%CI: 1.23, 1.75), eye (OR = 1.24, 95%CI: 1.04, 1.48) symptoms, school-days lost (OR = 1.24, 95%CI: 1.04, 1.48), and emergency (OR = 2.14, 95%CI: 1.47, 3.11) and hospital (OR = 2.21, 95%CI: 1.17, 4.18) admissions. There was an inverse dose-response relationship between the adverse health outcomes considered and the distance from the plants. The attributable fractions for the children living close to the chipboard industries were substantial, ranging from 13% (eye symptoms) to 27% (cough/phlegm).The present findings suggest that emissions from chipboard industries might have a serious impact on children's health status and should therefore be reduced and closely monitored.  相似文献   
77.
We report a simple way to produce fully densified aligned carbon nanotube (ACNT) films. The simultaneous growth of nanotubes and densification of the ACNT films by carbon infiltration in the interstitial spaces between nanotubes are accomplished in a single step by the combination of the chemical vapor deposition and chemical vapor infiltration processes. Scanning electron microscope analysis and microbalance measurements showed that after infiltration, the diameters of nanotubes and bulk density of the ACNT films are increased by an order of magnitude (and hence the porosity of the ACNT films is decreased). Transmission electron microscope and Raman scattering analysis showed that after densification, the nanotubes are conformally coated by partially graphitized pyrolytic carbon. The compressive modulus of the densified ACNT films could be increased by three orders of magnitude compared to the pristine ACNT films. Electrical properties are also measured for the densified films showing marked differences with the ACNT films. The property enhanced densified ACNT films constitute a new form of carbon-carbon nanocomposites and could find applications as multifunctional nanocomposites.  相似文献   
78.
Background: Immune-checkpoint inhibitors (ICIs) have increased and improved the treatment options for patients with non-oncogene-addicted advanced stage non-small cell lung cancer (NSCLC). However, the role of ICIs in oncogene-addicted advanced stage NSCLC patients is still debated. In this study, in an attempt to fill in the informational gap on the effect of ICIs on other driver mutations, we set out to provide a molecular landscape of clinically relevant oncogenic drivers in programmed death-ligand 1 (PD-L1) positive NSCLC patients. Methods: We retrospectively reviewed data on 167 advanced stage NSCLC PD-L1 positive patients (≥1%) who were referred to our clinic for molecular evaluation of five driver oncogenes, namely, EGFR, KRAS, BRAF, ALK and ROS1. Results: Interestingly, n = 93 (55.7%) patients showed at least one genomic alteration within the tested genes. Furthermore, analyzing a subset of patients with PD-L1 tumor proportion score (TPS) ≥ 50% and concomitant gene alterations (n = 8), we found that n = 3 (37.5%) of these patients feature clinical benefit with ICIs administration, despite the presence of a concomitant KRAS gene alteration. Conclusions: In this study, we provide a molecular landscape of clinically relevant biomarkers in NSCLC PD-L1 positive patients, along with data evidencing the clinical benefit of ICIs in patient NSCLC PD-L1 positive alterations.  相似文献   
79.
Background: Basal cell carcinoma is one of the most common types of non-melanoma skin cancers, which can be locally destructive despite low-rate metastasis. Surgery is the treatment of choice, but it lacks of efficacy on advanced cases. Hedgehog pathway inhibitors are a class of drugs providing a new therapeutic option for patients affected by advanced disease. Besides systemic therapy, such as vismodegib and sonidegib, also topical inhibitors have been developed. Patidegib is able to decrease tumor burden, reducing the adverse effects induced by systemic targeted therapies. Methods: We performed comprehensive research to summarize the use of patidegib in advanced and recurrent aggressive basal cell carcinomas. Only English language human studies were included in the search. Results: Seven trials reported the application of patidegib. Both topical and systemic patidegib demonstrated safety, tolerability, and efficacy in naïve patients with stage II and III basal cell carcinomas, while stage IV disease and not-naïve patients did not show any benefit. Conclusion: Unlike systemic Hedgehog pathway inhibitors, patidegib 2% gel is not associated with systemic adverse effects and allows a better patient management. Considering the multidisciplinary management of neoplasia, in the era of precision medicine, it is mandatory to confide in pharmacogenomics to obtain personalized combined or sequential therapies.  相似文献   
80.
Surface-enhanced Raman spectroscopy (SERS) exploiting Raman reporter-labeled nanoparticles (RR@NPs) represents a powerful tool for the improvement of optical bio-assays due to RRs’ narrow peaks, SERS high sensitivity, and potential for multiplexing. In the present work, starting from low-cost and highly available raw materials such as cysteamine and substituted benzoic acids, novel bioorthogonal RRs, characterized by strong signal (103 counts with FWHM < 15 cm−1) in the biological Raman-silent region (>2000 cm−1), RRs are synthesized by implementing a versatile, modular, and straightforward method with high yields and requiring three steps lasting 18 h, thus overcoming the limitations of current reported procedures. The resulting RRs’ chemical structure has SH-pendant groups exploited for covalent conjugation to high anisotropic gold-NPs. RR@NPs constructs work as SERS nanoprobes demonstrating high colloidal stability while retaining NPs’ physical and vibrational properties, with a limit of detection down to 60 pM. RR@NPs constructs expose carboxylic moieties for further self-assembling of biomolecules (such as antibodies), conferring tagging capabilities to the SERS nanoprobes even in heterogeneous samples, as demonstrated with in vitro experiments by transmembrane proteins tagging in cell cultures. Finally, thanks to their non-overlapping spectra, we envision and preliminary prove the possibility of exploiting RR@NPs constructs simultaneously, aiming at improving current SERS-based multiplexing bioassays.  相似文献   
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