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The importance, yet scarcity of the critical constants of thermally unstable fluids warrants the development of reliable methods for the estimation of these essential thermodynamic properties. A thorough investigation undertaken in this study on 1,589 compounds belonging to 83 chemical classes, indicated that the ratio of critical temperature to critical pressure of both low and high molecular weight compounds could be well expressed in terms of their volumetric properties. In addition, two new methodologies are presented for estimating Vc, as well as an indirect approach for prediction of Tc from surface tension data, altogether allowing the calculation of Zc. Moreover, comparative studies are made with five group contribution methods. It is also demonstrated that by employing the Peng-Robinson EOS, and without prior knowledge of the critical properties, it is possible to calculate various thermophysical properties including Psat., Tb, , ∆Hvap. , Cp, and even the Tc and Pc themselves. 相似文献
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Aneta Sevcikova Nikola Izoldova Viola Stevurkova Barbora Kasperova Michal Chovanec Sona Ciernikova Michal Mego 《International journal of molecular sciences》2022,23(1)
Understanding the mechanisms of resistance to therapy in human cancer cells has become a multifaceted limiting factor to achieving optimal cures in cancer patients. Besides genetic and epigenetic alterations, enhanced DNA damage repair activity, deregulation of cell death, overexpression of transmembrane transporters, and complex interactions within the tumor microenvironment, other mechanisms of cancer treatment resistance have been recently proposed. In this review, we will summarize the preclinical and clinical studies highlighting the critical role of the microbiome in the efficacy of cancer treatment, concerning mainly chemotherapy and immunotherapy with immune checkpoint inhibitors. In addition to involvement in drug metabolism and immune surveillance, the production of microbiota-derived metabolites might represent the link between gut/intratumoral bacteria and response to anticancer therapies. Importantly, an emerging trend of using microbiota modulation by probiotics and fecal microbiota transplantation (FMT) to overcome cancer treatment resistance will be also discussed. 相似文献
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The effect of calcinations of starting powder on the mechanical properties of hydroxyapatite (HA)-based bioceramic composite was investigated. The calcinations of HA powder in air at 900 °C increased the crystallinity as well as the size of the powder. Ball milling after the calcinations was effective in eliminating large agglomerates in the powder. When the powder was mixed with reinforcing Al2O3 powder, the mixture became fine and homogeneous. The flexural strength of HA–Al2O3 composite was increased by the calcinations processes at all the Al2O3 concentration. However, the fracture toughness was not much influenced by the calcinations. These results lead to the conclusion that the calcinations process effectively reduced the critical flaw size in the body by removing the agglomerates in the HA powder. 相似文献
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An analytical model of Al0.15Ga0.85N/GaN modulation doped field effect transistor (MODFET), which uses an accurate velocity field relationship and incorporates the dominant effect of piezoelectric polarization induced charge at the AlGaN/GaN interface is presented. The effect of traps has also been taken into account. The calculated DC characteristics are in excellent agreement with the measured data. The model is extended to predict the microwave performance of the device. High current levels (>500 mA/mm), large transconductance (160.83 mS/mm) and a high cutoff frequency (9.6 GHz) have been achieved analytically and are in close agreement with the experimental data. 相似文献
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Multicasting applications such as multimedia conferencing, online multiplayer interactive games, and distance learning are becoming increasingly popular. With multiprotocol label switching, Internet protocol networks can offer quality of service and traffic engineering capabilities. This article introduces several approaches for multisource multicast sessions in the context of IP over WDM networks and evaluates their performance in terms of blocking probability, time complexity, and memory consumption. Our simulation study shows that among all the approaches, the newly proposed approach, known as one Bidirectional Tree with Just enough bandwidth reserved on each link of the tree, achieves the best overall performance. 相似文献
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Krizkova S Fabrik I Huska D Adam V Babula P Hrabeta J Eckschlager T Pochop P Darsova D Kukacka J Prusa R Trnkova L Kizek R 《International journal of molecular sciences》2010,11(12):4826-4842
The drugs based on platinum metals represent one of the oldest, but also one of the most effective groups of chemotherapeutic agents. Thanks to many clinical studies it is known that resistance of tumor cells to drugs is a frequent cause of chemotherapy failure. With regard to platinum based drugs, multidrug resistance can also be connected with increased expression of low-molecular weight protein metallothionein (MT). This study aimed at investigating the interactions of MT with cisplatin or carboplatin, using the adsorptive transfer technique coupled with differential pulse voltammetry Brdicka reaction (AdTS DPV Brdicka reaction), and a comparison of in vitro results with results obtained in vivo. The results obtained from the in vitro study show a strong affinity between platinum based drugs and MT. Further, we analyzed extracts of neuroblastoma cell lines treated with cisplatin or carboplatin. It is clear that neuroblastoma UKF-NB-4 cisplatin-resistant and cisplatin-sensitive cell lines unlikely respond to the presence of the platinum-based cytostatics cisplatin and carboplatin. Finally, we determined the level of MT in samples from rabbits treated with carboplatin and patients with retinoblastoma treated with the same drug. 相似文献