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81.
82.
P. Carrasqueira H. Rocha J. M. Dias T. Ventura B. C. Ferreira M. C. Lopes 《International Transactions in Operational Research》2023,30(1):206-223
Radiation therapy is a technology-driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head-and-neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high-quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques. 相似文献
83.
Journal of Computer Science and Technology - DOACROSS loops are significant parts in many important scientific and engineering applications, which are generally exploited pipeline/wave-front... 相似文献
84.
El-Denglawey A. Issa Shams A. M. Saddeek Yasser B. Tekin H. O. Zakaly Hesham M. H. 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(10):3934-3942
Journal of Inorganic and Organometallic Polymers and Materials - This work aimed to investigate the impact of Lead-fluoride based glasses via theoretical and simulation techniques on mechanical and... 相似文献
85.
86.
Replacement of precious single metal catalysts with cost-effective, highly-dispersed composite catalysts for catalytic hydrothermal conversion of residue holds tremendous promise for the residue upgrading technologies. Organic metals were added to the feed as the oil-soluble precursors, and transformed into the catalytic active phases in this work. Physical properties and structures of the composite catalysts had been investigated by X-ray fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscope and transmission electron microscopy. The composite catalysts were found to be highly efficient in the catalytic hydrothermal conversion of both model compound and residue. Increased metal dispersion and synergistic effects of two metals played indispensable roles in such catalytic system. Results showed that under the test conditions in the article, the catalyst had the best catalytic performance when the mass ratio of molybdenum to iron was 1.5. 相似文献
87.
Neural Computing and Applications - Traffic identification is currently an important challenge for network management and security. In this paper, we propose a novel application identification... 相似文献
88.
Lydia Saidi Dr. Djenisa H. A. Rocha Dr. Oualid Talhi Dr. Yamina Bentarzi Prof. Dr. Bellara Nedjar-Kolli Dr. Khaldoun Bachari Dr. Filipe A. Almeida Paz Dr. Luisa A. Helguero Prof. Dr. Artur M. S. Silva 《ChemMedChem》2019,14(10):1041-1048
Breast and prostate cancers are frequently treated with chemotherapy. Several novel chemicals are being reported for this purpose, particularly synthetic and natural benzophenones. This work reports the synthesis of substituted 2-hydroxybenzophenones through 1,4-conjugate addition/intramolecular cycloaddition/dehydration of nitromethane on key intermediate chromones. Structures were extensively studied by means of 2D NMR spectroscopy and single-crystal XRD. Their cytotoxicity was evaluated in vitro in two breast cancer cell lines (MDA-MB-231 and T47-D) and one prostate cancer cell line (PC3). The most potent compound exhibited good cytotoxic effects against the three cancer cell lines (IC50 values ranging from 12.09 to 26.49 μm ) and induced cell-cycle retardation only on prostate cancer cells, which suggested that it might exert cell-type-specific effects. 相似文献
89.
Bram H. Frohock Jessica M. Gilbertie Dr. Jennifer C. Daiker Dr. Lauren V. Schnabel Dr. Joshua G. Pierce 《Chembiochem : a European journal of chemical biology》2020,21(7):933-937
The failure of frontline antibiotics in the clinic is one of the most serious threats to human health and requires a multitude of novel therapeutics and innovative approaches to treatment so as to curtail the growing crisis. In addition to traditional resistance mechanisms resulting in the lack of efficacy of many antibiotics, most chronic and recurring infections are further made tolerant to antibiotic action by the presence of biofilms. Herein, we report an expanded set of 5-benzylidene-4-oxazolidinones that are able to inhibit the formation of Staphylococcus aureus biofilms, disperse preformed biofilms, and, in combination with common antibiotics, are able to significantly reduce the bacterial load in a robust collagen-matrix model of biofilm infection. 相似文献
90.
Jie Gao Zhikai Li Mei Dong Weibin Fan Jianguo Wang 《Frontiers of Chemical Science and Engineering》2020,14(5):847
Coal-based ethanol production by hydration of ethylene is limited by the low equilibrium ethylene conversion at elevated temperature. To improve ethylene conversion, coupling hydration of ethylene with a potential ethanol consumption reaction was analyzed thermodynamically. Five reactions have been attempted and compared: (1) dehydration of ethanol to ethyl ether ( ), (2) dehydrogenation of ethanol to acetaldehyde ( ), (3) esterification of acetic acid with ethanol ( ), (4) dehydrogenation of ethanol to ethyl acetate ( ), and (5) oxidative dehydrogenation of ethanol to ethyl acetate ( ). The equilibrium constants and equilibrium distributions of the coupled reactions were calculated and the effects of feed composition, temperature and pressure upon the ethylene equilibrium conversion were examined. The results show that dehydrogenation of ethanol to acetaldehyde has little effect on ethylene conversion, whereas for dehydrogenation of ethanol to acetaldehyde and ethyl acetate, ethylene conversion can be improved from 8% to 12.8% and 18.5%, respectively, under conditions of H2O/C2H4 = 2, 10 atm and 300°C. The esterification of acetic acid with ethanol can greatly enhance the ethylene conversion to 22.5%; in particular, ethylene can be actually completely converted to ethyl acetate by coupling oxidative dehydrogenation of ethanol. 相似文献