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1.
Influence of compaction on the interfacial transition zone and the permeability of concrete 总被引:2,自引:0,他引:2
Andreas Leemann Beat Münch Philippe Gasser Lorenz Holzer 《Cement and Concrete Research》2006,36(8):1425-1433
The interfacial transition zone (ITZ) is regarded as a key feature for the transport properties and the durability of concrete. In this study one self-compacting concrete (SCC) mixture and two conventionally vibrated concrete (CVC) mixtures are studied in order to determine the influence of compaction on the porosity of the ITZ. Additionally oxygen permeability and water conductivity were measured in vertical and horizontal direction. The quantitative analysis of images made with an optical microscope and an environmental scanning electron microscope shows a significantly increased porosity and width of the ITZ in CVC compared to SCC. At the same time oxygen permeability and water conductivity of CVC are increased in comparison to SCC. Moreover, considerable differences in the porosity of the lower, lateral and upper ITZ are observed in both types of concrete. The anisotropic distribution of pores in the ITZ does not necessarily cause anisotropy in oxygen permeability and water conductivity though. 相似文献
2.
The diffusion coefficient \(D_{{{\text{O}}_{2} }}\), the porosity and the pore structure of mortars produced with a Portland cement and a range of blended cements containing limestone powder, microsilica, portlandite or slag were measured in the non-carbonated and the carbonated state. Additionally, the setup for measuring O2 diffusion was adapted to measure also the CO2 diffusion of the carbonated mortars. The diffusion coefficient \(D_{{{\text{O}}_{2} }}\) and the total porosity were increased in the mortars containing microsilica and slag, while they were decreased in the other mortars due to carbonation. Invariably, the pore structure became coarser in all samples. The relationship between diffusion coefficients \(D_{{{\text{O}}_{2} }}\) and \(D_{{{\text{CO}}_{2} }}\) in the carbonated mortars was always linear, with \(D_{{{\text{O}}_{2} }}\) systematically higher by factor of 1.37. As this factor broadly agrees with what was found in the scant literature about CO2 diffusion, it could be used for estimating \(D_{{{\text{CO}}_{2} }}\) of carbonated mortar and concrete based on measurements of O2 diffusion. 相似文献
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Sonia Domingos-Pereira Karthik Sathiyanadan Lenka Polak Jacques-Antoine Haefliger Martina Schmittnaegel Carola H. Ries Patrice Jichlinski Beat Roth Laurent Derr Denise Nardelli-Haefliger 《International journal of molecular sciences》2023,24(1)
Bacillus Calmette-Guérin (BCG) instillations for the treatment of non-muscle-invasive bladder cancer patients can result in significant side effects and treatment failure. Immune checkpoint blockade and/or decreasing tumor-infiltrating myeloid suppressor cells may be alternative or complementary treatments. Here, we have characterized immune cell infiltration and chemoattractant molecules in mouse orthotopic MB49 bladder tumors. Our data show a 100-fold increase in CD45+ immune cells from day 5 to day 9 tumors including T cells and mainly myeloid cells. Both monocytic myeloid-derived suppressor-cells (M-MDSC) and polymorphonuclear (PMN)-MDSC were strongly increased in day 9 tumors, with PMN-MDSC representing ca. 70% of the myeloid cells in day 12 tumors, while tumor associated macrophages (TAM) were only modestly increased. The kinetic of PD-L1 tumor expression correlated with published data from patients with PD-L1 expressing bladder tumors and with efficacy of anti-PD-1 treatment, further validating the orthotopic MB49 bladder-tumor model as suitable for designing novel therapeutic strategies. Comparison of chemoattractants expression during MB49 bladder tumors grow highlighted CCL8 and CCL12 (CCR2-ligands), CCL9 and CCL6 (CCR-1-ligands), CXCL2 and CXCL5 (CXCR2-ligands), CXCL12 (CXCR4-ligand) and antagonist of C5/C5a as potential targets to decrease myeloid suppressive cells. Data obtained with a single CCR2 inhibitor however showed that the complex chemokine crosstalk would require targeting multiple chemokines for anti-tumor efficacy. 相似文献
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J Schwaller J Frantsve J Aster IR Williams MH Tomasson TS Ross P Peeters L Van Rompaey RA Van Etten R Ilaria P Marynen DG Gilliland 《Canadian Metallurgical Quarterly》1998,17(18):5321-5333
Recent reports have demonstrated fusion of the TEL gene on 12p13 to the JAK2 gene on 9p24 in human leukemias. Three variants have been identified that fuse the TEL pointed (PNT) domain to (i) the JAK2 JH1-kinase domain, (ii) part of and (iii) all of the JH2 pseudokinase domain. We report that all of the human TEL/JAK2 variants, and a human/mouse chimeric hTEL/mJAK2(JH1) fusion gene, transform the interleukin-3 (IL-3)-dependent murine hematopoietic cell line Ba/F3 to IL-3-independent growth. Transformation requires both the TEL PNT domain and JAK2 kinase activity. Furthermore, all TEL/JAK2 variants strongly activated STAT 5 by phosphotyrosine Western blots and by electrophoretic mobility shift assays (EMSA). Mice (n = 40) transplanted with bone marrow infected with the MSCV retrovirus containing either the hTEL/mJAK2(JH1) fusion or its human counterpart developed a fatal mixed myeloproliferative and T-cell lymphoproliferative disorder with a latency of 2-10 weeks. In contrast, mice transplanted with a TEL/JAK2 mutant lacking the TEL PNT domain (n = 10) or a kinase-inactive TEL/JAK2(JH1) mutant (n = 10) did not develop the disease. We conclude that all human TEL/JAK2 fusion variants are oncoproteins in vitro that strongly activate STAT 5, and cause lethal myelo- and lymphoproliferative syndromes in murine bone marrow transplant models of leukemia. 相似文献
7.
We describe how interactive paper can be used together with a multi-channel web information system to build a platform for
experimenting with multi-modal context-aware mobile information services. As an application, we present a tourist guide for
visitors to an international festival that was developed to investigate alternative modes of information delivery and interaction
in mobile environments. The guide is based around a set of interactive paper documents—an event brochure, map and bookmark.
The brochure and map are augmented with digital services by using a digital pen to activate links and a text-to-speech engine
for information delivery. The digital pen is also used for data capture of event ratings and reviews. The bookmark provides
access to advanced searches and ticket reservations. We describe the architecture and operation of the system, highlighting
the challenges of extending a web information system to support both the generation of the paper documents and the interaction
from these documents, alongside more traditional access channels. Finally, we discuss the range of context-aware interactions
that is supported by our platform. 相似文献
8.
The Tyrosine Gate of the Bacterial Lectin FimH: A Conformational Analysis by NMR Spectroscopy and X‐ray Crystallography 下载免费PDF全文
Dr. Brigitte Fiege Dr. Said Rabbani Dr. Roland C. Preston Dr. Roman P. Jakob Pascal Zihlmann Dr. Oliver Schwardt Dr. Xiaohua Jiang Prof. Timm Maier Prof. Beat Ernst 《Chembiochem : a European journal of chemical biology》2015,16(8):1235-1246
Urinary tract infections caused by uropathogenic E. coli are among the most prevalent infectious diseases. The mannose‐specific lectin FimH mediates the adhesion of the bacteria to the urothelium, thus enabling host cell invasion and recurrent infections. An attractive alternative to antibiotic treatment is the development of FimH antagonists that mimic the physiological ligand. A large variety of candidate drugs have been developed and characterized by means of in vitro studies and animal models. Here we present the X‐ray co‐crystal structures of FimH with members of four antagonist classes. In three of these cases no structural data had previously been available. We used NMR spectroscopy to characterize FimH–antagonist interactions further by chemical shift perturbation. The analysis allowed a clear determination of the conformation of the tyrosine gate motif that is crucial for the interaction with aglycone moieties and was not obvious from X‐ray structural data alone. Finally, ITC experiments provided insight into the thermodynamics of antagonist binding. In conjunction with the structural information from X‐ray and NMR experiments the results provide a mechanism for the often‐observed enthalpy–entropy compensation of FimH antagonists that plays a role in fine‐tuning of the interaction. 相似文献
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The tetrasaccharide 4, a substructure of ganglioside GQ1balpha, shows a remarkable affinity for the myelin-associated glycoprotein (MAG) and was therefore selected as starting point for a lead optimization program. In our search for structurally simplified and pharmacokinetically improved mimics of 4, antagonists with modifications of the core disaccharide Galbeta(1-3)GalNAc, as well as the terminal alpha(2-3)- and the internal alpha(2-6)-linked neuraminic acid were synthesized and tested in target-based binding assays. Compared to the reference tetrasaccharide 4, the most potent antagonist 17 exhibits a 360-fold improved affinity. Furthermore, pharmacokinetic parameters such as stability in the cerebrospinal fluid, logD and permeation through the BBB indicate the drug-like properties of antagonist 17. 相似文献