2,218 research outputs found

    Helper T cells (CD3+/CD4+) within the autologous peripheral blood stem cell graft positively correlate with event free survival of multiple myeloma patients

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    The microenvironment in the bone marrow — including lymphocytes — is part of the pathophysiology of multiple myeloma (MM). High dose chemotherapy followed by autologous stem cell transplantation is standard of care for younger patients. Aim: To determine the influence of reinfused lymphocyte subsets on event free survival (EFS) and overall survival (OS). Methods: In peripheral blood (PB) and aphaeresis products (AP) of 41 MM patients lymphocyte subsets were determined by flow cytometry and were correlated with clinical outcome. Results: PB lymphocyte subsets did not influence EFS or OS. Residual plasma cells in the AP were not correlated with poor outcome, whereas a high percentage of B cells (CD19+) showed a trend towards reduced EFS (P = 0.051). A high amount of CD4 cells and an increased CD4/CD8 ratio were significantly associated with prolonged EFS. In contrast, high percentage of HLA-DR positive lymphocytes showed negative impact on EFS and OS (P = 0.03 and 0.02, respectively). Conclusion: Obtained data suggest the non-activated (HLA-DR negative) helper CD4+ T cells in the AP to be tumour protective.Микроокружение в костном мозге, включая лимфоциты, оказывает влияние на патофизиологию множественной миеломы (MM). Высокодозовая химиотерапия, за которой следует аутологическая трансплантация стволовых клеток, является стандартным подходом при лечении более молодых пациентов. Цель: изучить влияние введенных субпопуляций лимфоцитов на безрецидивную выживаемость (EFS) и общую выживаемость больных c ММ. Методы: методом проточной цитофлуориметрии в периферической крови (PB) и продуктах афереза (АР) пациентов с ММ ( n = 41) изучали субпопуляции лимфоцитов и возможную корреляцию с исходом болезни. Результаты: субпопуляции лимфоцитов РB не влияли на EFS или OS. Остаточные клетки плазмы в АР не коррелировали с плохим прогнозом, в тоже время при высоком содержании В-клеток (CD19+) отмечали тенденцию к снижению EFS (P = 0,051). Высокое содержание CD4-клеток и увеличение соотношения CD4/CD8 были достоверно ассоциированы с повышением EFS. В отличие от этого, высокий процент HLADR-положительных лимфоцитов имел отрицательное влияние на EFS и OS (P = 0,03 и 0,02 соответственно). Выводы: полученные данные позволяют предположить, что неактивированные (HLA-DR-отрицательные) хелперные CD4+ T-клетки в AP могут обладать антиопухолевыми свойствами

    Compact Source of EPR Entanglement and Squeezing at Very Low Noise Frequencies

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    We report on the experimental demonstration of strong quadrature EPR entanglement and squeezing at very low noise sideband frequencies produced by a single type-II, self-phase-locked, frequency degenerate optical parametric oscillator below threshold. The generated two-mode squeezed vacuum state is preserved for noise frequencies as low as 50 kHz. Designing simple setups able to generate non-classical states of light in the kHz regime is a key challenge for high sensitivity detection of ultra-weak physical effects such as gravitational wave or small beam displacement

    <sup>14</sup>C AMS at SUERC: improving QA data from the 5 MV tandem AMS and 250 kV SSAMS

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    In 2003, a National Electrostatics Corporation (NEC) 5MV tandem accelerator mass spectrometer was installed at SUERC, providing the radiocarbon laboratory with 14C measurements to 4–5‰ repeatability. In 2007, a 250kV single-stage accelerator mass spectrometer (SSAMS) was added to provide additional 14C capability and is now the preferred system for 14C analysis. Changes to the technology and to our operations are evident in our copious quality assurance data: typically, we now use the 134-position MC-SNICS source, which is filled to capacity. Measurement of standards shows that spectrometer running without the complication of on-line δ13C evaluation is a good operational compromise. Currently, 3‰ 14C/13C measurements are routinely achieved for samples up to nearly 3 half-lives old by consistent sample preparation and an automated data acquisition algorithm with sample random access for measurement repeats. Background and known-age standard data are presented for the period 2003–2008 for the 5MV system and 2007–2008 for the SSAMS, to demonstrate the improvements in data quality

    Rapid thinning of the late Pleistocene Patagonian Ice Sheet followed migration of the Southern Westerlies

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    Here we present the first reconstruction of vertical ice-sheet profile changes from any of the Southern Hemisphere's mid-latitude Pleistocene ice sheets. We use cosmogenic radio-nuclide (CRN) exposure analysis to record the decay of the former Patagonian Ice Sheet (PIS) from the Last Glacial Maximum (LGM) and into the late glacial. Our samples, from mountains along an east-west transect to the east of the present North Patagonian Icefield (NPI), serve as ‘dipsticks' that allow us to reconstruct past changes in ice-sheet thickness, and demonstrates that the former PIS remained extensive and close to its LGM extent in this region until ~19.0 ka. After this time rapid ice-sheet thinning, initiated at ~18.1 ka, saw ice at or near its present dimension by 15.5 ka. We argue this rapid thinning was triggered by a combination of the rapid southward migration of the precipitation bearing Southern Hemisphere (SH) westerlies and regional warming

    Gravitational-wave astronomy: the high-frequency window

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    This contribution is divided in two parts. The first part provides a text-book level introduction to gravitational radiation. The key concepts required for a discussion of gravitational-wave physics are introduced. In particular, the quadrupole formula is applied to the anticipated ``bread-and-butter'' source for detectors like LIGO, GEO600, EGO and TAMA300: inspiralling compact binaries. The second part provides a brief review of high frequency gravitational waves. In the frequency range above (say) 100Hz, gravitational collapse, rotational instabilities and oscillations of the remnant compact objects are potentially important sources of gravitational waves. Significant and unique information concerning the various stages of collapse, the evolution of protoneutron stars and the details of the supranuclear equation of state of such objects can be drawn from careful study of the gravitational-wave signal. As the amount of exciting physics one may be able to study via the detections of gravitational waves from these sources is truly inspiring, there is strong motivation for the development of future generations of ground based detectors sensitive in the range from hundreds of Hz to several kHz.Comment: 21 pages, 5 figures, Lectures presented at the 2nd Aegean Summer School on the Early Universe, Syros, Greece, September 200

    Teleportation of continuous variable polarisation states

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    This paper discusses methods for the optical teleportation of continuous variable polarisation states. We show that using two pairs of entangled beams, generated using four squeezed beams, perfect teleportation of optical polarisation states can be performed. Restricting ourselves to 3 squeezed beams, we demonstrate that polarisation state teleportation can still exceed the classical limit. The 3-squeezer schemes involve either the use of quantum non-demolition measurement or biased entanglement generated from a single squeezed beam. We analyse the efficacies of these schemes in terms of fidelity, signal transfer coefficients and quantum correlations

    GEO 600 and the GEO-HF upgrade program: successes and challenges

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    The German-British laser-interferometric gravitational wave detector GEO 600 is in its 14th year of operation since its first lock in 2001. After GEO 600 participated in science runs with other first-generation detectors, a program known as GEO-HF began in 2009. The goal was to improve the detector sensitivity at high frequencies, around 1 kHz and above, with technologically advanced yet minimally invasive upgrades. Simultaneously, the detector would record science quality data in between commissioning activities. As of early 2014, all of the planned upgrades have been carried out and sensitivity improvements of up to a factor of four at the high-frequency end of the observation band have been achieved. Besides science data collection, an experimental program is ongoing with the goal to further improve the sensitivity and evaluate future detector technologies. We summarize the results of the GEO-HF program to date and discuss its successes and challenges

    Fate specification and tissue-specific cell cycle control of the <i>Caenorhabditis elegans</i> intestine

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    Coordination between cell fate specification and cell cycle control in multicellular organisms is essential to regulate cell numbers in tissues and organs during development, and its failure may lead to oncogenesis. In mammalian cells, as part of a general cell cycle checkpoint mechanism, the F-box protein β-transducin repeat-containing protein (β-TrCP) and the Skp1/Cul1/F-box complex control the periodic cell cycle fluctuations in abundance of the CDC25A and B phosphatases. Here, we find that the Caenorhabditis elegans β-TrCP orthologue LIN-23 regulates a progressive decline of CDC-25.1 abundance over several embryonic cell cycles and specifies cell number of one tissue, the embryonic intestine. The negative regulation of CDC-25.1 abundance by LIN-23 may be developmentally controlled because CDC-25.1 accumulates over time within the developing germline, where LIN-23 is also present. Concurrent with the destabilization of CDC-25.1, LIN-23 displays a spatially dynamic behavior in the embryo, periodically entering a nuclear compartment where CDC-25.1 is abundant

    Achieving ground state and enhancing entanglement by recovering information

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    For cavity-assisted optomechanical cooling experiments, it has been shown in the literature that the cavity bandwidth needs to be smaller than the mechanical frequency in order to achieve the quantum ground state of the mechanical oscillator, which is the so-called resolved-sideband or good-cavity limit. We provide a new but physically equivalent insight into the origin of such a limit: that is information loss due to a finite cavity bandwidth. With an optimal feedback control to recover those information, we can surpass the resolved-sideband limit and achieve the quantum ground state. Interestingly, recovering those information can also significantly enhance the optomechanical entanglement. Especially when the environmental temperature is high, the entanglement will either exist or vanish critically depending on whether information is recovered or not, which is a vivid example of a quantum eraser.Comment: 9 figures, 18 page
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