1,464 research outputs found

    Innovations in hematopoietic stem-cell mobilization: A review of the novel CXCR4 inhibitor motixafortide

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    Hematopoietic stem-cell transplantation (HCT) and stem-cell-based gene therapies rely on the ability to collect sufficient CD34+ hematopoietic stem and progenitor cells (HSPCs), typicall

    Suicide genes: Monitoring cells in patients with a safety switch

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    Clinical trials increasingly incorporate suicide genes either as direct lytic agents for tumors or as safety switches in therapies based on genetically modified cells. Suicide genes can also be used as non-invasive reporters to monitor the biological consequences of administering genetically modified cells to patients and gather information relevant to patient safety. These genes can monitor therapeutic outcomes addressable by early clinical intervention. As an example, our recent clinical trial used 18F-9-(4-fluoro-3-hydroxymethylbutyl)guanine (18FHBG) and PET/CT scans to follow T cells transduced with herpes simplex virus thymidine kinase (TK) after administration to patients. Guided by preclinical data we ultimately hope to discern whether a particular pattern of transduced T cell migration within patients reflects early development of Graft vs. Host Disease (GvHD). Current difficulties in terms of choice of suicide gene, biodistribution of radiolabeled tracers in humans versus animal models, and threshold levels of genetically modified cells needed for detection by PET/CT are discussed. As alternative suicide genes are developed, additional radiolabel probes suitable for imaging in patients should be considered

    Автоматизированный ΠΊΠΎΠ½Ρ‚Ρ€ΠΎΠ»ΡŒ ΠΊΠΎΠ½Ρ‚ΡƒΡ€ΠΎΠ² рСгулирования нСфтСхимичСского производства

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    ΠžΠ±ΡŠΠ΅ΠΊΡ‚ΠΎΠΌ исслСдования являСтся модСль тСхнологичСского процСсса ΠΏΠ΅Ρ€Π΅Ρ€Π°Π±ΠΎΡ‚ΠΊΠΈ сырой Π½Π΅Ρ„Ρ‚ΠΈ разработанная Π² Honeywell UniSim design suite. ЦСлью магистСрской диссСртации являСтся Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠ° ΠΈ исслСдованиС Π°Π²Ρ‚ΠΎΠΌΠ°Ρ‚ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π½Π½ΠΎΠΉ систСмы ΠΌΠΎΠ½ΠΈΡ‚ΠΎΡ€ΠΈΠ½Π³Π° ΠΊΠ»ΡŽΡ‡Π΅Π²Ρ‹Ρ… ΠΏΠΎΠΊΠ°Π·Π°Ρ‚Π΅Π»Π΅ΠΉ эффСктивности ΠΊΠΎΠ½Ρ‚ΡƒΡ€ΠΎΠ² автоматичСского рСгулирования нСфтСхимичСского производства. Π’ Ρ€Π°Π±ΠΎΡ‚Π΅ прСдставлСны: Π°Π½Π°Π»ΠΈΠ· ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΎΠ² ΠΌΠΎΠ½ΠΈΡ‚ΠΎΡ€ΠΈΠ½Π³Π° ΠΊΠΎΠ½Ρ‚ΡƒΡ€ΠΎΠ² управлСния, Π°Π½Π°Π»ΠΈΠ· влияния ΠΊΠΎΠ½Ρ‚ΡƒΡ€ΠΎΠ² управлСния Π½Π° тСхнологичСский процСсс, Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠ° интСрфСйса Π²Ρ‹Π²ΠΎΠ΄Π° тСхнологичСских ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΎΠ², Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠ° систСмы ΠΌΠΎΠ½ΠΈΡ‚ΠΎΡ€ΠΈΠ½Π³Π° тСхнологичСского процСсса Π½Π° языкС программирования C#, построСниС ΠΊΠΎΠ½Ρ‚Ρ€ΠΎΠ»ΡŒΠ½Ρ‹Ρ… ΠΊΠ°Ρ€Ρ‚ Π¨ΡƒΡ…Π°Ρ€Ρ‚Π° с автоматичСским Π°Π½Π°Π»ΠΈΠ·ΠΎΠΌ Π΄Π°Π½Π½Ρ‹Ρ….The object of research is a model of the technological process of crude oil refining developed in the Honeywell UniSim design suite. The aim of the master's thesis is to develop and study an automated system for monitoring key performance indicators of the loopd of automatic regulation of petrochemical production. This work presents: an analysis of methods for monitoring control loops, an analysis of the influence of control loops on a technological process, the development of an interface for outputting technological parameters, the development of a process monitoring system in the C # programming language, the construction of Shewhart control charts with automatic data analysis

    Transmit simulation and receive optimizations for 802.11b networks

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    Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.Includes bibliographical references (p. 72-73).This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.The simulation presented in this paper provides an implementation of a full simulated transmit chain from packet encoding through base band modulation for the 802.11b wireless networking standard. This forward transmit chain is coupled with a physical channel simulation that can introduce a number of different channel effects to simulate interference caused in the real world. Packets which the transmit simulation produces can be sent to a receive simulation to test design parameters or can be modulated and sent to 802.11b hardware to test hardware implementation. Using former procedure, this paper also evaluates implementations of a Phase lock loop used to track Frequency Doppler and a Time Tracking Loop used to track Code Doppler under various Signal to Noise levels. The results from these simulations can be used to optimize various receive parameters and algorithms.by Pascal F. Rettig.M.Eng

    Coherent excitations and electron phonon coupling in Ba/EuFe_2As_2 compounds investigated by femtosecond time- and angle-resolved photoemission spectroscopy

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    We employed femtosecond time- and angle-resolved photoelectron spectroscopy to analyze the response of the electronic structure of the 122 Fe-pnictide parent compounds Ba/EuFe_2As_2 and optimally doped BaFe_{1.85}Co_{0.15}As_2 near the \Gamma point to femtosecond optical excitation. We identify pronounced changes of the electron population within several 100 meV above and below the Fermi level, which we explain as combination of (i) coherent lattice vibrations, (ii) a hot electron and hole distribution, and (iii) transient modifications of the chemical potential. The response of the three different materials is very similar. In the Fourier transformation of the time-dependent photoemission intensity we identify three modes at 5.6, 3.3, and 2.6 THz. While the highest frequency mode is safely assigned to the A_{1g} mode, the other two modes require a discussion in comparison to literature. The time-dependent evolution of the hot electron distribution follows a simplified description of a transient three temperature model which considers two heat baths of lattice vibrations, which are more weakly and strongly coupled to transiently excited electron population. Still the energy transfer from electrons to the strongly coupled phonons results in a rather weak, momentum-averaged electron-phonon coupling quantified by values for \lambda between 30 and 70 meV^2. The chemical potential is found to present a transient modulation induced by the coherent phonons. This change in the chemical potential is particularly strong in a two band system like in the 122 Fe-pnictide compounds investigated here due to the pronounced variation of the electrons density of states close to the equilibrium chemical potential.Comment: 10 pages, 6 figure

    Energy dissipation in the time domain governed by bosons in a correlated material

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    In complex materials various interactions play important roles in determining the material properties. Angle Resolved Photoelectron Spectroscopy (ARPES) has been used to study these processes by resolving the complex single particle self energy Ξ£(E)\Sigma(E) and quantifying how quantum interactions modify bare electronic states. However, ambiguities in the measurement of the real part of the self energy and an intrinsic inability to disentangle various contributions to the imaginary part of the self energy often leave the implications of such measurements open to debate. Here we employ a combined theoretical and experimental treatment of femtosecond time-resolved ARPES (tr-ARPES) and show how measuring the population dynamics using tr-ARPES can be used to separate electron-boson interactions from electron-electron interactions. We demonstrate the analysis of a well-defined electron-boson interaction in the unoccupied spectrum of the cuprate Bi2_{2}Sr2_{2}CaCu2_{2}O8+x_{8+x} characterized by an excited population decay time constant Ο„QP\tau_{QP} that maps directly to a discrete component of the equilibrium self energy not readily isolated by static ARPES experiments.Comment: 19 pages with 6 figure
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