403 research outputs found

    Low noise all-fiber amplification of a coherent supercontinuum at 2 \mu m and its limits imposed by polarization noise

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    We report the amplification of an all-normal dispersion supercontinuum pulse in a Thulium / Holmium co-doped all-fiber chirped pulse amplification system. With a -20 dB bandwidth of more than 300 nm in the range 1800-2100 nm the system delivers high quality 66 fs pulses with more than 70 kW peak power directly from the output fiber. The coherent seeding of the entire emission bandwidth of the doped fiber and the stability of the supercontinuum generation dynamics in the silicate glass all-normal dispersion photonic crystal fiber result in excellent noise characteristics of the amplified ultrashort pulses

    IL-6 production in ovarian carcinoma is associated with histiotype and biological characteristics of the tumour and influences local immunity

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    The presence of interleukin (IL)-6 in peritoneal carcinomatous fluid (PCF) and its effect on immune cells composition in PCF in patients with advanced ovarian carcinoma was studied. In 21 out of 30 ovarian carcinoma patients, PCF IL-6 levels were found to exceed those seen in PCFs of patients with gastrointestinal cancer. IL-6 activity was higher in serous/mucinous than in endometrioid and undifferentiated ovarian carcinoma PCF (P = 0.05). Ovarian carcinoma PCF IL-6 activities were correlated with serum C-reactive protein levels (r = 0.65, P = 0.0000, n = 25). Ovarian carcinoma PCF leucocyte profile differed from that in blood with respect to: (i) lower percentage of NK and CD8+and (ii) higher percentage of B and CD45RO+, CD14+and HLA-DR+cells. The proportions of CD45RO+in blood were correlated with IL-6 levels in PCF. Corresponding to PCF ovarian carcinoma tumours were stained for the presence of Ki-67 antigen and p53. The highest proportions of Ki-67+cells and cells showing accumulation of p53 were seen in undifferentiated tumours. A low grade of p53 staining was seen in tumours associated with high IL-6 levels in PCF. It was evident that IL-6 production (i) depended on the histiotype of the tumour, (ii) influenced the local immune system in favour of accumulation of B, and T memory cells, and (iii) was higher in patients lacking p53 accumulation. © 2000 CancerResearch Campaig

    Period doubling eigenstates in a fiber laser mode-locked by nonlinear polarization rotation

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    Due to the weak birefringence of single mode fibers, solitons generated in fiber lasers are indeed vector pulses and exhibit periodic parameter change including polarization evolution even when there is a polarizer inside the cavity. Period doubling eigenstates of solitons generated in a fiber laser mode-locked by the nonlinear polarization rotation, i.e., period doubling of polarization components of the soliton, are numerically explored in detail. We found that, apart from the synchronous evolution between the two polarization components, there exists asynchronous development depending on the detailed operation conditions. In addition, period doubling of one polarization component together with period-one of another polarization component can be achieved. When the period tripling window is obtained, much complexed dynamics on the two polarization components could be observed.Comment: 6 page

    Near Surface Crystallization of Pluronic P123

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    On a hydrophilic substrate the growth of a Bragg peak was observed at Q≈0.05 Å−1 which we attribute to a layering of micelles. This ordering is destroyed when the system is sheared. When shear is removed, it builds up and reaches equilibrium at ambient temperature after approximately 700s. However, there is a waiting time of 200s before any structure becomes visible again. When lower shear rates are applied the ordering recovers more quickly, but it does not build up to the same extent

    A conserved phosphorylation site regulates the transcriptional function of ETHYLENE-INSENSITIVE3-like1 in tomato

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    ETHYLENE-INSENSITIVE3/ETHYLENE-INSENSITIVE3-like (EIN3/EIL) transcription factors are important downstream components of the ethylene transduction pathway known to regulate the transcription of early ethylene-responsive genes in plants. Previous studies have shown that phosphorylation can repress their transcriptional activity by promoting protein degradation. The present study identifies a new phosphorylation region named EPR1 (EIN3/EIL phosphorylation region 1) in tomato EIL1 proteins. The functional significance of EPR1 was tested by introducing mutations in this region of the Sl-EIL1 gene and by expressing these mutated versions in transgenic tomato plants. Transient expression data and phenotypic analysis of the transgenic lines indicated that EPR1 is essential for the transcriptional activity of Sl-EIL1. Moreover, mutation in the EPR1 site that prevents phosphorylation abolishes ethylene constitutive responses normally displayed by the Sl-EIL1-overexpressing lines. Bimolecular fluorescence complementation (BiFC) studies showed that the presence of a functional phosphorylation site within EPR1 is instrumental in the dimerization of Sl-EIL1 proteins. The results illuminate a new molecular mechanism for the control of EIN3/EIL activity and propose a model where phosphorylation within the EPR1 promotes the dimerization process allowing the initiation of EIL-mediated transcription of early ethylene-regulated genes

    Allogeneic bone marrow (BM) peripheral blood progenitor cells (PBPC) transplantations in two cases prepared with the use of total body irradiation (TBI)

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    The main aims for preparative regimens in BMT/PBPCT are malignant cell eradication and/or immunosupresion to facilitate engraftment. TBI is used in concert with cyclophospamide (Cy) to increase activity.In our Unit two TBI + Cy conditioned allotransplantations – (1) BMT and (2) PBPCT – have been performed. Patients – (1) 7 years and (2) 10 years old, males, suffering from: (1) ALL – second and (2) ALL – fourth remission, received transplant material from HLA identical siblings. Transplant preparative regimens consisted of TBI (Co-60 + electrons 6 and 9 MeV: 12–16 Gy. performed in Greatpoland Cancer Centre, Poznań) and Cy (200 mg/kg bw). Patients received routine decontamination for infection prevention. Heparine for VOD and Cyclosporine + MTX for GvHD prophylaxis. Treatment related toxicity was judged accordind to WHO scale, standard criteria were used for GvHD grading.Both patients were Hepatitis B virus positive, patient (2) was also HCV + before treatment. Hematological recovery was observed in both patient (1) 13 and (2) 10 days after transplantation. Toxicity in patient (1) was WHO-1 for the liver and WHO-1 for kidneys. There was no skin or mucosal toxicity. Patient (2) had WHO-2 GIT mucosa and WHO-3 liver toxicities on day +15. No skin toxicity was observed. On day +16 patient(2) rapidly developed signs of pulmonary complications further followed by CNS involvement. He required artificial ventilation. No aGvHD observed. Patient died on day +31. Patient (1) is alive and well +36 days after transplantation. aGvHD grade I (skin) was observed on day +25 after transplantation and responded well to glukokorticosteroid therapy (2mg/kg for 5 days).The post-transplant history of these two cases reflects on possible complications of BMT/PBPCT with TBI

    Deformation Associated with Ghost Craters and Basins in Volcanic Smooth Plains on Mercury: Strain Analysis and Implications for Plains Evolution

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    Since its insertion into orbit about Mercury in March 2011, the MESSENGER spacecraft has imaged most previously unseen regions of the planet in unprecedented detail, revealing extensive regions of contiguous smooth plains at high northern latitudes and surrounding the Caloris basin. These smooth plains, thought to be emplaced by flood volcanism, are populated with several hundred ghost craters and basins, nearly to completely buried impact features having rims for which the surface expressions are now primarily rings of deformational landforms. Associated with some ghost craters are interior groups of graben displaying mostly polygonal patterns. The origin of these graben is not yet fully understood, but comparison with numerical models suggests that the majority of such features are the result of stresses from local thermal contraction. In this paper, we highlight a previously unreported category of ghost craters, quantify extensional strains across graben-bearing ghost craters, and make use of graben geometries to gain insights into the subsurface geology of smooth plains areas. In particular, the style and mechanisms of graben development imply that flooding of impact craters and basins led to substantial pooling of lavas, to thicknesses of ∼1.5 km. In addition, surface strains derived from groups of graben are generally in agreement with theoretically and numerically derived strains for thermal contraction

    Nonlinear Absorbing-Loop Mirror in a Holmium-Doped Fiber Laser

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    An Assemblage of Lava Flow Features on Mercury

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    In contrast to other terrestrial planets, Mercury does not possess a great variety of volcanic features, its history of volcanism instead largely manifest by expansive smooth plains. However, a set of landforms at high northern latitudes on Mercury resembles surface flow features documented on Earth, the Moon, Mars, and Venus. The most striking of such landforms are broad channels that host streamlined islands and that cut through the surrounding intercrater plains. Together with narrower, more sinuous channels, coalesced depressions, evidence for local flooding of intercrater plains by lavas, and a first-order analysis of lava flow rates, the broad channels define an assemblage of flow features formed by the overland flow of, and erosion by, voluminous, high-temperature, low-viscosity lavas. This interpretation is consistent with compositional data suggesting that substantial portions of Mercury's crust are composed of magnesian, iron-poor lithologies. Moreover, the proximity of this partially flooded assemblage to extensive volcanic plains raises the possibility that the formation of these flow features may preface total inundation of an area by lavas emplaced in a flood mode and that they escaped complete burial only due to a waning magmatic supply. Finally, that these broad channels on Mercury are volcanic in nature yet resemble outflow channels on Mars, which are commonly attributed to catastrophic water floods, implies that aqueous activity is not a prerequisite for the formation of such distinctive landforms on any planetary body

    Detection of genome-wide polymorphisms in the AT-rich Plasmodium falciparum genome using a high-density microarray

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    <p>Abstract</p> <p>Background</p> <p>Genetic mapping is a powerful method to identify mutations that cause drug resistance and other phenotypic changes in the human malaria parasite <it>Plasmodium falciparum</it>. For efficient mapping of a target gene, it is often necessary to genotype a large number of polymorphic markers. Currently, a community effort is underway to collect single nucleotide polymorphisms (SNP) from the parasite genome. Here we evaluate polymorphism detection accuracy of a high-density 'tiling' microarray with 2.56 million probes by comparing single feature polymorphisms (SFP) calls from the microarray with known SNP among parasite isolates.</p> <p>Results</p> <p>We found that probe GC content, SNP position in a probe, probe coverage, and signal ratio cutoff values were important factors for accurate detection of SFP in the parasite genome. We established a set of SFP calling parameters that could predict mSFP (SFP called by multiple overlapping probes) with high accuracy (≥ 94%) and identified 121,087 mSFP genome-wide from five parasite isolates including 40,354 unique mSFP (excluding those from multi-gene families) and ~18,000 new mSFP, producing a genetic map with an average of one unique mSFP per 570 bp. Genomic copy number variation (CNV) among the parasites was also cataloged and compared.</p> <p>Conclusion</p> <p>A large number of mSFP were discovered from the <it>P. falciparum </it>genome using a high-density microarray, most of which were in clusters of highly polymorphic genes at chromosome ends. Our method for accurate mSFP detection and the mSFP identified will greatly facilitate large-scale studies of genome variation in the <it>P. falciparum </it>parasite and provide useful resources for mapping important parasite traits.</p
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