552 research outputs found
Least-Squares Fitting of Time-Domain Signals for Fourier Transform Mass Spectrometry
No full textTo advance Fourier transform mass spectrometry (FTMS)-based molecular structure analysis, corresponding development of the FTMS signal processing methods and instrumentation is required. Here, we demonstrate utility of a least-squares fitting (LSF) method for analysis of FTMS time-domain (transient) signals. We evaluate the LSF method in the analysis of single- and multiple-component experimental and simulated ion cyclotron resonance (ICR) and Orbitrap FTMS transient signals. Overall, the LSF method allows one to estimate the analytical limits of the conventional instrumentation and signal processing methods in FTMS. Particularly, LSF provides accurate information on initial phases of sinusoidal components in a given transient. For instance, the phase distribution obtained for a statistical set of experimental transients reveals the effect of the first data-point problem in FT-ICR MS. Additionally, LSF might be useful to improve the implementation of the absorption-mode FT spectral representation for FTMS applications. Finally, LSF can find utility in characterization and development of filter-diagonalization method (FDM) MS. Figure
Multi-omics “upstream analysis” of regulatory genomic regions helps identifying targets against methotrexate resistance of colon cancer
No full textAbstractWe present an “upstream analysis” strategy for causal analysis of multiple “-omics” data. It analyzes promoters using the TRANSFAC database, combines it with an analysis of the upstream signal transduction pathways and identifies master regulators as potential drug targets for a pathological process. We applied this approach to a complex multi-omics data set that contains transcriptomics, proteomics and epigenomics data. We identified the following potential drug targets against induced resistance of cancer cells towards chemotherapy by methotrexate (MTX): TGFalpha, IGFBP7, alpha9-integrin, and the following chemical compounds: zardaverine and divalproex as well as human metabolites such as nicotinamide N-oxide
Least-Squares Fitting of Time-Domain Signals for Fourier Transform Mass Spectrometry
No full textTo advance Fourier transform mass spectrometry (FTMS)-based molecular structure analysis, corresponding development of the FTMS signal processing methods and instrumentation is required. Here, we demonstrate utility of a least-squares fitting (LSF) method for analysis of FTMS time-domain (transient) signals. We evaluate the LSF method in the analysis of single- and multiple-component experimental and simulated ion cyclotron resonance (ICR) and Orbitrap FTMS transient signals. Overall, the LSF method allows one to estimate the analytical limits of the conventional instrumentation and signal processing methods in FTMS. Particularly, LSF provides accurate information on initial phases of sinusoidal components in a given transient. For instance, the phase distribution obtained for a statistical set of experimental transients reveals the effect of the first data-point problem in FT-ICR MS. Additionally, LSF might be useful to improve the implementation of the absorption-mode FT spectral representation for FTMS applications. Finally, LSF can find utility in characterization and development of filter-diagonalization method (FDM) MS.LSMBNational Licence
Comparison of dynamic properties of InP/InAs quantum-dot and quantum-dash lasers
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 109, 161104 (2016) and may be found at https://doi.org/10.1063/1.4965846.The dynamic properties of MOVPE grown InP/InAs quantum-dot and quantum-dash lasers, showing identical structural design, emitting in the C-band are investigated and compared to each other. Based on the small-signal measurements, we show the impact of the density of states function on the cut-off frequency, being larger for quantum dots at low currents, and reaching similar values for quantum dashes only at higher currents. The large-signal measurements show error-free data transmission at 22.5 and 17.5 Gbit/s for the quantum-dot and quantum-dash lasers.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/EU/264687/Postgraduate Research on Photonics as an Enabling Technology/PROPHE
Мамлюки династии Бахри в социально-политической жизни Египта и Ближнего Востока (XIII-XIV века)
No full textДиссертационная работа посвящена анализу мамлюкской системы власти в Египте, взаимоотношений и взаимосвязей мамлюков с соседними странами и ведущими государствами, игравшими важную роль в политической жизни XIII-XIV вв. Структура диссертации состоит из введения, трех глав, заключения, списка источников и литературы. Во введении рассматривается актуальность, объект и предмет, теоретико-методологические основания исследования, степень изученности проблемы и анализ источников, определены цели и задачи. В первой главе дан историографический обзор и анализ источников проблемы. Во второй главе рассматриваются вопросы становления мамлюкской системы власти в Египте, взлет и расцвет мамлюкских султанов бахритской (1250 – 1382/1390 гг.) династии. В третьей главе показано, как мамлюки в условиях жесткого противостояния на Ближнем Востоке с ведущими европейскими государствами, ближневосточными крестоносцами, монголами Ирана сумели провозгласить независимую арабо-мусульманскую империю, игравшую значительную роль на международной арене в XIII – XIV вв. В магистерской диссертации раскрывается процесс объединения значительной части средневекового Востока под эгидой державы мамлюков. В заключении подводятся итоги и делаются выводы по теме. В списке источников и литературы приведен перечень источников и литературы, использованной в магистерской диссертации. В процессе анализа источников и научной литературы автор опирается на хронологические и структурно-тематические принципы. В работе активно используются такие общенаучные методы как: метод классификации, историко-сравнительный, ретроспективный. Ключевые слова: Ближний Восток, Египет, Сирия, мамлюки, бахриты, мусульмане, крестоносцы, монголыThis study examines the Mamluks system of rule in Egypt, the relationships of the Mamluks with neighboring countries and leading states which played an important role in the political life in the 13th-14th centuries. The thesis consists of an introduction, three chapters, conclusion, list of sources and literature. The introduction shows the urgency of the research, the object and the subject, the theoretical and methodological foundations of the study, the degree of knowledge of the problem and the analysis of sources, and determines the goals of the research. The first chapter provides a historiographical review and analyzes the sources which were used in this study. The second chapter deals with the formation of the Mamluks system of Rule in Egypt, the rise and the period of prosperity of the Bahri Mamluks (1250-1382 / 1390). The third chapter shows how the Mamluks managed to create an independent Arab-Muslim empire in conditions of a tough struggle in the Middle East with leading European states, Middle Eastern Crusaders, and Iranian Mongols. Also, this chapter shows a significant role of Mamluk Sultanate in the international arena in the 13th-14th centuries. Furthermore, the chapter reveals the process of unifying a significant part of the medieval East under the auspices of the Mamluks. The conclusion sums up the results of the research. The list of sources and literature contains a list of sources and literature used in the master's thesis. In the process of analyzing sources and scientific literature, the author relies on chronological and structural-thematic principles. Actively used such general scientific methods as a classification method, historical-comparative and retrospective method. Keywords: The Middle East, Egypt, Syria, Mamluks, the Bahri dynasty, Muslims, Crusaders, Mongol
Refractory CrMoNbWV High-Entropy Alloy Manufactured by Mechanical Alloying and Spark Plasma Sintering: Evolution of Microstructure and Properties
No full textIn this study, bulk samples of a CrMoNbWV high-entropy alloy (HEA) were obtained for the first time by spark plasma sintering (SPS) of mechanically alloyed (MA) powders at 1200 °C, 1300 °C, and 1400 °C. Microstructure evolution, phase formation as well as wear and corrosion behavior were investigated. The MA powders’ phase composition was found to be represented by body-centered-cubic (BCC) solid solution. The solid solution partially decomposed to Laves phases under the sintering, such as Cr2Nb and (Fe, Cr)Nb, and NbVO4-VO oxides mixture. The temperature increase to 1400 °C led to a grain coarsening of the BCC phase and decreased the Laves phase content accompanied by precipitation at the grain boundaries. The sintered samples showed high hardness and compressive strength (2700–2800 MPa) at room temperature. The wear tests demonstrated excellent results in comparison to conventional wear-resistant composites. The obtained samples also exhibited high corrosion resistance under electrochemical tests in H2SO4 solution. The CrMoNbWV HEA has comparable mechanical and corrosive properties with the WNbMoTaV type HEA, but at the same time has a reduced density: CrMoNbWV—10.55 g/cm3, WNbMoTaV—12.42 g/cm3Team Vera Popovic
Highly efficient non-degenerate four-wave mixing under dual-mode injection in InP/InAs quantum-dash and quantum-dot lasers at 1.55 μm
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 107, 191111 (2015) and may be found at https://doi.org/10.1063/1.4935796.This work reports on non-degenerate four-wave mixing under dual-mode injection in metalorganic vapor phase epitaxy grown InP/InAs quantum-dash and quantum dot Fabry-Perot laser operating at 1550 nm. High values of normalized conversion efficiency of −18.6 dB, optical signal-to-noise ratio of 37 dB, and third order optical susceptibility normalized to material gain χ(3)/g0 of ∼4 × 10−19 m3/V3 are measured for 1490 μm long quantum-dash lasers. These values are similar to those obtained with distributed-feedback lasers and semiconductor optical amplifiers, which are much more complicated to fabricate. On the other hand, due to the faster gain saturation and enhanced modulation of carrier populations, quantum-dot lasers demonstrate 12 dB lower conversion efficiency and 4 times lower χ(3)/g0 compared to quantum dash lasers.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/EU/264687/Postgraduate Research on Photonics as an Enabling Technology/PROPHE
1.55-μm mode-locked quantum-dot lasers with 300 MHz frequency tuning range
No full textThis article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 106, 031114 (2015) and may be found at https://doi.org/10.1063/1.4906451.Passive mode-locking of two-section quantum-dot mode-locked lasers grown by metalorganic vapor phase epitaxy on InP is reported. 1250-μm long lasers exhibit a wide tuning range of 300 MHz around the fundamental mode-locking frequency of 33.48 GHz. The frequency tuning is achieved by varying the reverse bias of the saturable absorber from 0 to −2.2 V and the gain section current from 90 to 280 mA. 3 dB optical spectra width of 6–7 nm leads to ex-facet optical pulses with full-width half-maximum down to 3.7 ps. Single-section quantum-dot mode-locked lasers show 0.8 ps broad optical pulses after external fiber-based compression. Injection current tuning from 70 to 300 mA leads to 30 MHz frequency tuning.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/EU/264687/Postgraduate Research on Photonics as an Enabling Technology/PROPHE
Erratum to: Measurement of the top quark mass with lepton+jets final states using pp collisions at
No full textIn this article the author name Luigi Calligaris was incorrectly written as A. Calligaris. The original article has been corrected
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