2,677 research outputs found

    A Robust Solution to the Super-Resolution Phase Problem in Scanning Transmission Electron Microscopy

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    From a set of images, each of poor resolution, recorded in a transmission microscope under many different incident angles of coherent illumination, it is possible to obtain wavelength-limited resolution even if there is a narrow aperture lying in the back-focal plane of the imaging lens. This is achieved by a deconvolution algorithm which retrieves the phase of the Fourier transform of the specimen. The method accounts for complex components in the transfer function of the lens, is not very sensitive to defocus and is remarkably resilient to noise. It may have important applications in overcoming the resolution limit in the scanning transmission electron microscope (STEM), where such data are readily available

    Optical ptychography with extended depth of field

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    Ptychography is an increasingly popular phase imaging technique. However, like any imaging technique it has a depth of field that limits the volume of a thick specimen that can be imaged in focus. Here, we have proposed to extend the depth of field using a multislice calculation model; an optical experiment successfully demonstrates our proposal

    Initial high anti-emetic efficacy of granisetron with dexamethasone is not maintained over repeated cycles.

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    We have reported previously that the anti-emetic efficacy of single agent 5HT3 antagonists is not maintained when analysed with the measurement of cumulative probabilities. Presently, the most effective anti-emetic regimen is a combination of a 5HT3 antagonist plus dexamethasone. We, therefore, assessed the sustainment of efficacy of such a combination in 125 patients, scheduled to receive cisplatin > or = 70 mg m(-2) either alone or in combination with other cytotoxic drugs. Anti-emetic therapy was initiated with 10 mg of dexamethasone and 3 mg of granisetron intravenously, before cisplatin. On days 1-6, patients received 8 mg of dexamethasone and 1 mg of granisetron twice daily by oral administration. Protection was assessed during all cycles and calculated based on cumulative probability analyses using the method of Kaplan-Meier and a model for transitional probabilities. Irrespective of the type of analysis used, the anti-emetic efficacy of granisetron/dexamethasone decreased over cycles. The initial complete acute emesis protection rate of 66% decreased to 30% according to the method of Kaplan-Meier and to 39% using the model for transitional probabilities. For delayed emesis, the initial complete protection rate of 52% decreased to 21% (Kaplan-Meier) and to 43% (transitional probabilities). In addition, we observed that protection failure in the delayed emesis period adversely influenced the acute emesis protection in the next cycle. We conclude that the anti-emetic efficacy of a 5HT3 antagonist plus dexamethasone is not maintained over multiple cycles of highly emetogenic chemotherapy, and that the acute emesis protection is adversely influenced by protection failure in the delayed emesis phase

    Filming activities for the farmer-to-farmer instruction videos on labor-saving weed management options

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    Quantum information with structured light

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    We investigate structured photons as carriers of quantum information. We describe our implementation of quantum cryptography with orbital angular momentum, and present our results on efficient implementation of quantum state tomography for structured light fields

    Long-Term Outcomes and Practical Considerations in the Pharmacological Management of Tyrosinemia Type 1

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    Tyrosinemia type 1 (TT1) is a rare metabolic disease caused by a defect in tyrosine catabolism. TT1 is clinically characterized by acute liver failure, development of hepatocellular carcinoma, renal and neurological problems, and consequently an extremely poor outcome. This review showed that the introduction of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) in 1992 has revolutionized the outcome of TT1 patients, especially when started pre-clinically. If started early, NTBC can prevent liver failure, renal problems, and neurological attacks and decrease the risk for hepatocellular carcinoma. NTBC has been shown to be safe and well tolerated, although the long-term effectiveness of treatment with NTBC needs to be awaited. The high tyrosine concentrations caused by treatment with NTBC could result in ophthalmological and skin problems and requires life-long dietary restriction of tyrosine and its precursor phenylalanine, which could be strenuous to adhere to. In addition, neurocognitive problems have been reported since the introduction of NTBC, with hypothesized but as yet unproven pathophysiological mechanisms. Further research should be done to investigate the possible relationship between important clinical outcomes and blood concentrations of biochemical parameters such as phenylalanine, tyrosine, succinylacetone, and NTBC, and to develop clear guidelines for treatment and follow-up with reliable measurements. This all in order to ultimately improve the combined NTBC and dietary treatment and limit possible complications such as hepatocellular carcinoma development, neurocognitive problems, and impaired quality of life

    Gene Expression Profiling in a Mouse Model Identifies Fetal Liver- and Placenta-Derived Potential Biomarkers for Down Syndrome Screening

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    BACKGROUND: As a first step to identify novel potential biomarkers for prenatal Down Syndrome screening, we analyzed gene expression in embryos of wild type mice and the Down Syndrome model Ts1Cje. Since current Down Syndrome screening markers are derived from placenta and fetal liver, these tissues were chosen as target. METHODOLOGY/PRINCIPAL FINDINGS: Placenta and fetal liver at 15.5 days gestation were analyzed by microarray profiling. We confirmed increased expression of genes located at the trisomic chromosomal region. Overall, between the two genotypes more differentially expressed genes were found in fetal liver than in placenta. Furthermore, the fetal liver data are in line with the hematological aberrations found in humans with Down Syndrome as well as Ts1Cje mice. Together, we found 25 targets that are predicted (by Gene Ontology, UniProt, or the Human Plasma Proteome project) to be detectable in human serum. CONCLUSIONS/SIGNIFICANCE: Fetal liver might harbor more promising targets for Down Syndrome screening studies. We expect these new targets will help focus further experimental studies on identifying and validating human maternal serum biomarkers for Down Syndrome screening

    Comparability of antibody response to a booster dose of 7-valent pneumococcal conjugate vaccine in infants primed with either 2 or 3 doses

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    In this cohort study we compared IgG antibody levels between infants immunized with 7-valent CRM197-conjugated pneumococcal vaccine (PCV-7) at 2,4 and 11 months and at 2, 3, 4 and 11 months of age,as measured by double adsorption ELISA. Pre- and post-booster levels following the 2 + 1 - and 3 + 1-dose schedule were comparable for 5 out of 7 serotypes except for serotypes 6B and 19F. The proportion of children reaching post-booster antibody thresholds were comparable except for 6B (>= 1.0 mu g/ml and >= 5.0 mu g/ml) and 19F (>= 5.0 mu g/ml). Surveillance studies are warranted for vaccine impact on 6B and 19F disease cases after reduced-dose PCV-7 schedules. (C) 2009 Elsevier Ltd. All rights reserved

    Ptychographic electron microscopy using high-angle dark-field scattering for sub-nanometre resolution imaging

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    Diffractive imaging, in which image-forming optics are replaced by an inverse computation using scattered intensity data, could, in principle, realize wavelength-scale resolution in a transmission electron microscope. However, to date all implementations of this approach have suffered from various experimental restrictions. Here we demonstrate a form of diffractive imaging that unshackles the image formation process from the constraints of electron optics, improving resolution over that of the lens used by a factor of five and showing for the first time that it is possible to recover the complex exit wave (in modulus and phase) at atomic resolution, over an unlimited field of view, using low-energy (30 keV) electrons. Our method, called electron ptychography, has no fundamental experimental boundaries: further development of this proof-of-principle could revolutionize sub-atomic scale transmission imaging

    Weekly low-dose mitoxantrone plus doxorubicin as second-line chemotherapy for advanced breast cancer

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    Weekly low dose mitoxantrone (3 mg/m2) plus doxorubicin (8 mg/m2) was administered as second-line chemotherapy to 33 patients with advanced breast cancer. Four out of 28 evaluable patients (14%) obtained a partial response with a median duration of 34 weeks (range 18-67+ weeks), while 8 patients (29%) showed stable disease with a median duration of 28 weeks (range 11+-60 weeks). Gastrointestinal toxicity and alopecia were mild. Grade II and III leukopenia occurred in 63% of the courses without serious infectious disease. Four patients experienced an asymptomatic drop of 16-20% in the left ventricular ejection fraction (LVEF) after relatively low cumulative doses of each drug, and one patient with a history of pericarditis carcinomatosa and mediastinal irradiation developed a heart failure. In conclusion, this second-line combination treatment had moderate activity in breast cancer and caused only few subjective side effects, especially with respect to gastrointestinal symptoms
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