| 1. |
- Ablikim, M., et al.
(författare)
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Observation of e(+)e(-) -> pi(0)pi(0)h(c) and a Neutral Charmoniumlike Structure Z(c)(4020)(0)
- 2014
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:21, s. 212002-
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Tidskriftsartikel (refereegranskat)abstract
- Using data collected with the BESIII detector operating at the Beijing Electron Positron Collider at center-of-mass energies of root s = 4.23, 4.26, and 4.36 GeV, we observe e(+)e(-) -> pi(0)pi(0)h(c) for the first time. The Born cross sections are measured and found to be about half of those of e(+)e(-) -> pi(+)pi(-)h(c) within less than 2 sigma. In the pi(0)h(c) mass spectrum, a structure at 4.02 GeV/c(2) is found. It is most likely to be the neutral isospin partner of the Z(c)(4020)(+/-) observed in the process of e(+)e(-) -> pi(+)pi(-)h(c) being found. A fit to the pi(0)h(c) invariant mass spectrum, with the width of the Z(c)(4020)(0) fixed to that of its charged isospin partner and possible interferences with non-Z(c)(4020)(0) amplitudes neglected, gives a mass of (4023.9 +/- 2.2 +/- 3.8) MeV/c(2) for the Z(c)(4020)(0), where the first error is statistical and the second systematic.
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| 2. |
- Ablikim, M., et al.
(författare)
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Search for the weak decays J/psi -> D-s(()*()-) e(+)nu(e) + c.c.
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:11, s. 112014-
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Tidskriftsartikel (refereegranskat)abstract
- Using a sample of 2.25 x 10(8) J/psi events collected with the BESIII detector at the BEPCII collider, we search for the J/psi semileptonic weak decay J/psi -> D-s(-) e(+)nu(e) +c.c. with a much higher sensitivity than previous searches. We also perform the first search for J/psi -> D-s(*-) e(+) nu(e) + c.c. No significant excess of a signal above background is observed in either channel. At the 90% confidence level, the upper limits are determined to be B(J/psi -> D-s(-) e(+) nu(e) + c.c.) < 1.3 x 10(-6) and B(J/psi -> D-s*(-) e(+) nu(e) + c.c.) < 1.8 x 10(-6), respectively. Both are consistent with Standard Model predictions.
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| 3. |
- Ablikim, M., et al.
(författare)
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Search for C-parity violation in J/psi -> gamma gamma and gamma phi
- 2014
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 90:9, s. 092002-
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Tidskriftsartikel (refereegranskat)abstract
- Using 1.06 x 10(8) psi(3686) events recorded in e(+)e(-) collisions at root s = 3.686 GeV with the BESIII at the BEPCII collider, we present searches for C-parity violation in J/psi -> gamma gamma and gamma phi decays via psi(3686) -> J/psi pi(+)pi(-). No significant signals are observed in either channel. Upper limits on the branching fractions are set to be B(J/psi -> gamma gamma) < 2.7 x 10(-7) and B(J/psi -> gamma phi) < 1.4 x 10(-6) at the 90% confidence level. The former is one order of magnitude more stringent than the previous upper limit, and the latter represents the first limit on this decay channel.
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| 4. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 5. |
- Hallac, B. B., et al.
(författare)
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Effect of Ethanol Organosolv Pretreatment on Enzymatic Hydrolysis of Buddleja davidii Stem Biomass
- 2010
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 49:4, s. 1467-1472
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Tidskriftsartikel (refereegranskat)abstract
- Ethanol organosolv pretreatment was performed on Buddleja davidii to evaluate this bioresource as a potential feedstock for bioethanol production. B. davidii was pretreated and delignified, while 85% of the glucose content of the untreated material was retained in the pretreated solid fraction. The enzymatic hydrolysis showed that organosolv pretreatment produced solid substrates that were readily digestible by cellulases. Gel-permeation chromatography was used to determine the degree of polymerization (DP) of cellulose, and solid-state cross polarization/magic angle spinning 13C NMR experiments were conducted to study the changes in crystallinity and ultrastructure of cellulose. The results showed a decrease in DP along with an increase in the relative proportions of para-crystalline and amorphous cellulose and a decrease in cellulose Ia̧ and Ib̃. Removal of lignin and hemicellulose, reduction in DP, and decrease in the crystalline allomorphs (Ia̧ and Ib̃) increased the amenability of the biomass to enzymatic degradation.
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| 6. |
- Pu, X., et al.
(författare)
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A wireless 8-channel ECG biopotential acquisition system for dry electrodes
- 2012
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Ingår i: Proceedings of the 2012 IEEE International Symposium on Radio-Frequency Integration Technology. - Singapore : IEEE Press. - 9781467323048 ; , s. 140-142
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Konferensbidrag (refereegranskat)abstract
- A wireless 8-channel biopotential acquisition system for capturing electrocardiogram (ECG) using dry electrodes is presented. The ECG system consists of copper electrodes, a micropowered 8-channel custom ASIC, and an off-the-shelf microprocessor and bluetooth radio. Each analog channel of the custom ECG front-end is composed of a chopper-modulated instrumentation amplifier (CMIA) with chopping spike filter (CSF), a programmable gain amplifier (PGA), and a output buffer. Implemented in standard a 0.35 μm CMOS technology, the ECG front-end consumes 101 μA from a 2.7 V supply, occupying 5 mm2 of chip area. Measurement results show an input impedance of 1 G Ω, an input-referred noise of 0.97 μVrms (0.5 ∼ 100 Hz), and a CMRR of 114 dB. Finally, a complete wireless 8-channel ECG monitoring system incorporating this analog front-end is demonstrated, showing successful recordings of a capture ECG waveform using a smart phone.
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| 7. |
- Yan, J. H., et al.
(författare)
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Chemical compositions of four switchgrass populations
- 2010
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 34:1, s. 48-53
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Tidskriftsartikel (refereegranskat)abstract
- Four populations of switchgrass (Alamo, GA993, GA992, Kanlow), Panicum virgatum L., were studied for the difference of their chemical constituents. The extractives, Klason lignin, and carbohydrates compositions of the stem portion of these switchgrass populations were determined by gas chromatography mass spectroscopy (GC-MS) and high performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) respectively. Ball milled grass lignin (BMGL) was isolated and analyzed by NMR spectroscopy. The results demonstrated that the chemical compositions of four switchgrass populations were similar with the exception of the lignin content and chemical composition of extractives. The results of quantitative C-13 NMR spectroscopy indicated that switchgrass lignin consisted of p-hydroxylphenyl, guaiacyl, and syringyl units in an average ratio of 26:42:32 and incorporated with p-coumaric acid and ferulic acid at a level of approximately 0.20 per aromatic ring. The lignin structure of four switchgrass cultivars was comparable.
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