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The Cabibbo-allowed weak radiative decay Λ+c→Σ+γ has been searched for in a sample of Λ+cΛ¯−c pairs produced in e+e− annihilations, corresponding to an integrated luminosity of 4.5fb−1 collected with the BESIII detector at center-of-mass energies between 4.60 and 4.70 GeV. No excess of signal above background is observed, and we set an upper limit on the branching fraction of this decay to be B(Λ+c→Σ+γ)<4.4×10−4 at a confidence level of 90\%, which is in agreement with Standard Model expectations.
Based on 7.33 fb−1 of e+e− collision data taken at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of D∗+s→D+sπ0 relative to that of D∗+s→D+sγ to be (6.16±0.43±0.19)%. The first uncertainty is statistical and the second one is systematic. By using the world average value of the branching fraction of D∗+s→D+se+e−, we determine the branching fractions of D∗+s→D+sγ and D∗+s→D+sπ0 to be (93.57±0.44±0.19)% and (5.76±0.44±0.19)%, respectively.
Based on 7.33 fb−1 of e+e− collision data taken at center-of-mass energies between 4.128 and 4.226 GeV with the BESIII detector, we measure the branching fraction of D∗+s→D+sπ0 relative to that of D∗+s→D+sγ to be (6.16±0.43±0.19)%. The first uncertainty is statistical and the second one is systematic. By using the world average value of the branching fraction of D∗+s→D+se+e−, we determine the branching fractions of D∗+s→D+sγ and D∗+s→D+sπ0 to be (93.57±0.44±0.19)% and (5.76±0.44±0.19)%, respectively.
Based on electron positron collision data collected with the BESIII detector operating at the BEPCII storage rings, the differential cross sections of inclusive π0 and K0S production as a function of hadron momentum, normalized by the total cross section of the e+e−→ hadrons process, are measured at six center-of-mass energies from 2.2324 to 3.6710 GeV. Our results with a relative hadron energy coverage from 0.1 to 0.9 significantly deviate from several theoretical calculations based on existing fragmentation functions, especially at lower energies.
Extending the carotenoid pathway to astaxanthin in plants is of scientific and industrial interest. However, expression of a microbial beta-carotene ketolase (BKT) that catalyses the formation of ketocarotenoids in transgenic plants typically results in low levels of astaxanthin. The low efficiency of BKTs in ketolating zeaxanthin to astaxanthin is proposed to be the major limitation for astaxanthin accumulation in engineered plants. To verify this hypothesis, several algal BKTs were functionally characterized using an Escherichia coli system and three BKTs were identified, with high (up to 85%), moderate (~38%), and low (~1%) conversion rate from zeaxanthin to astaxanthin from Chlamydomonas reinhardtii (CrBKT), Chlorella zofingiensis (CzBKT), and Haematococcus pluvialis (HpBKT3), respectively. Transgenic Arabidopsis thaliana expressing the CrBKT developed orange leaves which accumulated astaxanthin up to 2 mg g -1 dry weight with a 1.8-fold increase in total carotenoids. In contrast, the expression of CzBKT resulted in much lower astaxanthin content (0.24 mg g -1 dry weight), whereas HpBKT3 was unable to mediate synthesis of astaxanthin in A. thaliana. The none-native astaxanthin was found mostly in a free form integrated into the light-harvesting complexes of photosystem II in young leaves but in esterified forms in senescent leaves. The alteration of carotenoids did not affect chlorophyll content, plant growth, or development significantly. The astaxanthin-producing plants were more tolerant to high light as shown by reduced lipid peroxidation. This study advances a decisive step towards the utilization of plants for the production of high-value astaxanthin. Keywords: Arabidopsis thaliana, astaxanthin, beta-carotene ketolase, carotenoid, Haematococcus pluvialis
Formalin‐fixed, paraffin‐embedded (FFPE ), biobanked tissue samples offer an invaluable resource for clinical and biomarker research. Here, we developed a pressure cycling technology (PCT )‐SWATH mass spectrometry workflow to analyze FFPE tissue proteomes and applied it to the stratification of prostate cancer (PC a) and diffuse large B‐cell lymphoma (DLBCL ) samples. We show that the proteome patterns of FFPE PC a tissue samples and their analogous fresh‐frozen (FF ) counterparts have a high degree of similarity and we confirmed multiple proteins consistently regulated in PC a tissues in an independent sample cohort. We further demonstrate temporal stability of proteome patterns from FFPE samples that were stored between 1 and 15 years in a biobank and show a high degree of the proteome pattern similarity between two types of histological regions in small FFPE samples, that is, punched tissue biopsies and thin tissue sections of micrometer thickness, despite the existence of a certain degree of biological variations. Applying the method to two independent DLBCL cohorts, we identified myeloperoxidase, a peroxidase enzyme, as a novel prognostic marker. In summary, this study presents a robust proteomic method to analyze bulk and biopsy FFPE tissues and reports the first systematic comparison of proteome maps generated from FFPE and FF samples. Our data demonstrate the practicality and superiority of FFPE over FF samples for proteome in biomarker discovery. Promising biomarker candidates for PC a and DLBCL have been discovered.