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2.
Many rate constants of elementary steps on single crystals have been measured. Their pre-exponential factors can now be compared to those calculated by transition state theory. Such a calculation is presented in this Letter with due attention to microscopic reversibility, standard states, and configurational entropy. 相似文献
3.
After a period of general nonspecific symptoms (weakness; nocturnal sweating) for a few days a 29-year-old man suddenly developed a purpura-like rash on both hands and feet ("glove and sock") with mild itching and oedema. A blood count demonstrated leukopenia (2100/microliters) with neutropenia (1100/microliters), thrombocytopenia (81,000/microliters) and reticulocytopenia (1/1000), while haemoglobin content was normal. The bone-marrow showed almost complete reduction of erythropoiesis with the presence of giant proerythroblasts. Granulopoiesis and megakaryopoiesis were unremarkable. Positive tests for IgM and IgG antibodies against parvovirus B19 established the diagnosis of infection with this organism. The rash, blood picture and bone-marrow changes all regressed spontaneously, without any treatment, within a week. The petechial or purpuric "glove and sock" syndrome may be a special form of parvovirus B19 infection. 相似文献
4.
Jiang Wang Chunlei Liu Christian LeinenbachUlrich E. Klotz Peter J. UggowitzerJörg F. Löffler 《Calphad》2011,35(1):82-94
The Cu-Sn-Ti ternary system has been studied via experiments and thermodynamic modelling. In the experimental section, the composition of the alloys was selected based on the preliminary calculations and available literature data. Metallography, scanning electron microscopy and electron probe microanalysis were employed to analyse alloy samples prepared by arc-melting after annealing at 800 °C for 760 h. Solid phase relations at 800 °C were established. In contrast to earlier reports, the CuSn3Ti5 phase was interpreted as a binary intermetallic compound (Sn3Ti5) with extended Cu solubility. In the modelling section, three binary sub-systems were critically evaluated and updated according to the new experimental data and theoretical calculations reported in literature. According to their crystal structures and homogeneity ranges, appropriate sublattice models were proposed for SnTi3,SnTi2,Sn3Ti5 and Sn5Ti6. A set of self-consistent thermodynamic parameters for the Cu-Sn-Ti ternary system was obtained by considering the present experimental results and reported experimental information. The calculated results compare with the available experimental data to validate the present thermodynamic assessment. 相似文献
5.
A turbulent environment characterized by unsteady economic cycles, customized products, a growing bandwidth of products, an exploding number of variants and shorter product life cycles force manufacturers to permanent adaptation of their factories. Flexible and changeable structures will be required to enable factories dealing with the technological challenges and economic pressure of the future competitively. In order to achieve changeability objectives in manufacturing, a detailed analysis of existing structures and its representative attributes is essential. It is the basis for systematic structure planning of factories. In this paper a method for analyzing the capacitive and technological structure of a factory embedded in a network of manufacturing and its network of suppliers is presented. The synchronization of product and production development under the influence of change is intended. Therefore, the structural views of product and production are specifically in focus of the method. Based on the results of the analysis models an approach of a tool for giving product and production structure dynamism is suggested to investigate the effects and dependencies of change drivers in manufacturing. 相似文献
6.
Powder Metallurgy (PM) technology is emerging as one of the most promising techniques for the manufacture of net shape components and panels of aluminium foam. Control of the stability of the aluminium foaming process is one of the key issues in a serial production. Since there are many different parameters to be controlled in the raw material, the precursor and the finished foam part, the best solution is to keep all these factors in one centre of competence to exclude external influences and transporting problems. The latest material for the foaming tools plays also a decisive role concerning a high surface quality and a constant heat generation within the foam. New developments such as a precursor testing equipment or a foaming optimized furnace construction guarantees constant production conditions to be equipped for a more and more demanding market. 相似文献
7.
Amanda Gabrielle da Silva Luiz Ricardo Goulart Philipp Lffler Christian Code Adriana Freitas Neves 《International journal of molecular sciences》2022,23(22)
Limitations in the detection of cocirculating flaviviruses such as Dengue and Zika lead us to propose the use of aptameric capture of the viral RNA in combination with RT-PCR (APTA-RT-PCR). Aptamers were obtained via SELEX and next-generation sequencing, followed by colorimetric and fluorescent characterizations. An APTA-RT-PCR assay was developed, optimized, and tested against the viral RNAs in 108 serum samples. After selection, sequence APTAZC10 was designed as a bifunctional molecular beacon (APTAZC10-MB), exhibiting affinity for the viral targets. APTA-RT-PCR was able to detect Dengue and Zika RNA in 43% and 8% of samples, respectively. Our results indicate that APTAZC10-MB and APTA-RT-PCR will be useful to improve the detection of Dengue and Zika viruses in a fast molecular assay for the improvement of infectious disease surveillance. 相似文献
8.
9.
Judit Molnár Gábor J. Szebeni Boglárka Csupor-L?ffler Zsuzsanna Hajdú Thomas Szekeres Philipp Saiko Imre Ocsovszki László G. Puskás Judit Hohmann István Zupkó 《International journal of molecular sciences》2016,17(2)
Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1), 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13)-en-12,6α-olide (2), iso-seco-tanapartholide 3-O-methyl ether (3) and 4β,15-dihydro-3-dehydrozaluzanin C (4), were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica). When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC50 values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1) population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents. 相似文献
10.
Zoran V. Popovic Felix Bestvater Damir Krunic Bernhard K. Krmer Raoul Bergner Christian Lffler Berthold Hocher Alexander Marx Stefan Porubsky 《International journal of molecular sciences》2021,22(14)
The CD73 pathway is an important anti-inflammatory mechanism in various disease settings. Observations in mouse models suggested that CD73 might have a protective role in kidney damage; however, no direct evidence of its role in human kidney disease has been described to date. Here, we hypothesized that podocyte injury in human kidney diseases alters CD73 expression that may facilitate the diagnosis of podocytopathies. We assessed the expression of CD73 and one of its functionally important targets, the C-C chemokine receptor type 2 (CCR2), in podocytes from kidney biopsies of 39 patients with podocytopathy (including focal segmental glomerulosclerosis (FSGS), minimal change disease (MCD), membranous glomerulonephritis (MGN) and amyloidosis) and a control group. Podocyte CD73 expression in each of the disease groups was significantly increased in comparison to controls (p < 0.001–p < 0.0001). Moreover, there was a marked negative correlation between CD73 and CCR2 expression, as confirmed by immunohistochemistry and immunofluorescence (Pearson r = −0.5068, p = 0.0031; Pearson r = −0.4705, p = 0.0313, respectively), thus suggesting a protective role of CD73 in kidney injury. Finally, we identify CD73 as a novel potential diagnostic marker of human podocytopathies, particularly of MCD that has been notorious for the lack of pathological features recognizable by light microscopy and immunohistochemistry. 相似文献