948 research outputs found
Identification and analysis of phosphorylation status of proteins in dormant terminal buds of poplar
<p>Abstract</p> <p>Background</p> <p>Although there has been considerable progress made towards understanding the molecular mechanisms of bud dormancy, the roles of protein phosphorylation in the process of dormancy regulation in woody plants remain unclear.</p> <p>Results</p> <p>We used mass spectrometry combined with TiO<sub>2 </sub>phosphopeptide-enrichment strategies to investigate the phosphoproteome of dormant terminal buds (DTBs) in poplar (<it>Populus simonii × P. nigra</it>). There were 161 unique phosphorylated sites in 161 phosphopeptides from 151 proteins; 141 proteins have orthologs in <it>Arabidopsis</it>, and 10 proteins are unique to poplar. Only 34 sites in proteins in poplar did not match well with the equivalent phosphorylation sites of their orthologs in <it>Arabidopsis</it>, indicating that regulatory mechanisms are well conserved between poplar and <it>Arabidopsis</it>. Further functional classifications showed that most of these phosphoproteins were involved in binding and catalytic activity. Extraction of the phosphorylation motif using Motif-X indicated that proline-directed kinases are a major kinase group involved in protein phosphorylation in dormant poplar tissues.</p> <p>Conclusions</p> <p>This study provides evidence about the significance of protein phosphorylation during dormancy, and will be useful for similar studies on other woody plants.</p
Quantum state engineering by periodical two-step modulation in atomic system
By periodical two-step modulation, we demonstrate that the dynamics of
multilevel system can still evolve even in multiple large detunings regime, and
provide the effective Hamiltonian (of interest) for this system. We then
illustrate this periodical modulation in quantum state engineering, including
achieving direct transition from the ground state to the Rydberg state or the
desired superposition of two Rydberg states without satisfying two-photon
resonance condition, switching between Rydberg blockade regime and Rydberg
antiblockade regime, stimulating distinct atomic transitions by the same laser
field, and implementing selective transitions in the same multilevel system.
Particularly, it is robust against perturbation of control parameters. Another
advantage is that the waveform of laser field has simple square-wave form which
is readily implemented in experiments. Thus, it offers us a novel method of
quantum state engineering in quantum information processing.Comment: 16 pages, 12 figure
Conditional Positional Encodings for Vision Transformers
We propose a conditional positional encoding (CPE) scheme for vision
Transformers. Unlike previous fixed or learnable positional encodings, which
are pre-defined and independent of input tokens, CPE is dynamically generated
and conditioned on the local neighborhood of the input tokens. As a result, CPE
can easily generalize to the input sequences that are longer than what the
model has ever seen during training. Besides, CPE can keep the desired
translation-invariance in the image classification task, resulting in improved
classification accuracy. CPE can be effortlessly implemented with a simple
Position Encoding Generator (PEG), and it can be seamlessly incorporated into
the current Transformer framework. Built on PEG, we present Conditional
Position encoding Vision Transformer (CPVT). We demonstrate that CPVT has
visually similar attention maps compared to those with learned positional
encodings. Benefit from the conditional positional encoding scheme, we obtain
state-of-the-art results on the ImageNet classification task compared with
vision Transformers to date. Our code will be made available at
https://github.com/Meituan-AutoML/CPVT .Comment: A general purpose conditional position encoding for vision
transformer
Roles of Pro- and Anti-Inflammatory Cytokines in the Pathogenesis of SLE
SLE is an autoimmune inflammatory disease in which various pro- and anti-inflammatory cytokines, including TGF-β, IL-10, BAFF, IL-6, IFN-α, IFN-γ, IL-17, and IL-23, play crucial pathogenic roles. Virtually, all these cytokines can be generated by both innate and adaptive immune cells and exert different effects depending on specific local microenvironment. They can also interact with each other, forming a complex network to maintain delicate immune homeostasis. In this paper, we elaborate on the abnormal secretion and functions of these cytokines in SLE, analyze their potential pathogenic roles, and probe into the possibility of them being utilized as targets for therapy
A Sodium laser guide star coupling efficiency measurement method
Large telescope's adaptive optics (AO) system requires one or several bright
artificial laser guide stars to improve its sky coverage. The recent advent of
high power sodium laser is perfect for such application. However, besides the
output power, other parameters of the laser also have significant impact on the
brightness of the generated sodium laser guide star mostly in non-linear
relationships. When tuning and optimizing these parameters it is necessary to
tune based on a laser guide star generation performance metric. Although return
photon flux is widely used, variability of atmosphere and sodium layer make it
difficult to compare from site to site even within short time period for the
same site. A new metric, coupling efficiency is adopted in our field tests. In
this paper, we will introduce our method for measuring the coupling efficiency
of a 20W class pulse sodium laser for AO application during field tests that
were conducted during 2013-2015
High-proportion breast milk feeding is associated with a reduction in the incidence of IVH in very preterm infants
ObjectiveTo investigate the protective effect of high-proportion breast milk feeding (>50%) on intraventricular hemorrhage (IVH) in very preterm infants (VPIs).MethodsThis was a retrospective secondary analysis of a prospective multi-center study, which included 604 VPIs from six hospitals in eastern China between September 2019 and December 2020. The 604 VPIs were divided into two groups according to whether IVH occurred. High-proportion breast milk feeding was defined as breast milk accounting for 51–100% of the total feeding amount both within 7 days and throughout the hospitalization. The IVH grades and the rate of high-proportion breast milk feeding were analyzed. Furthermore, to explore the relationship between high-proportion breast milk feeding and IVH grading, the VPIs' general information, perinatal factors, growth, and nutritional status during hospitalization, and related complications were compared between the two groups.ResultsHigh-proportion breast milk feeding was reported in 63.41% of the VPIs. Furthermore, IVH grades I–II and III–IV were noted in 39.73% (240/604) and 1.66% (10/604) of the VPIs, respectively. Univariate analysis revealed that IVH occurrence in VPIs is influenced by perinatal factors, invasive respiratory therapy, high-proportion breast milk feeding, start feeding with breast milk, the cumulative amount of early parenteral nutrition, postnatal complications, physical growth, and other factors (P < 0.05). After adjustments for gestational age, birth weight, and possible influencing factors through binary logistic regression analysis, the results revealed that high-proportion breast milk feeding and and start feeding with breast milk were associated with a lower total incidence of IVH. Further stratification showed that high-proportion breast milk feeding was associated with a lower incidence of grade I–II IVH. Similarly, after adjusting for the same factors, breast milk feeding >50% in the 1st week was associated with a decreased incidence of total IVH and further stratification showed that it was associated with a lower incidence of grade I–II IVH.ConclusionHigh-proportion breast milk feeding and breast milk feeding more than 50% of total intake during the 1st week might be protective factors for IVH grade I–II in VPIs, which further verified the neuroprotective effect of breast milk. In clinical practice, the construction of breast milk banks should be strengthened, breast milk feeding should be encouraged in neonatal intensive care units, and efforts should be made to increase breast milk feeding rates to improve the outcomes of VPIs
Bis[μ-1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene-κ2 N 3:N 3′]silver(I) dinitrate dihydrate
The reaction of 1,4-bis(4,5-dihydro-1H-imidazol-2-yl)benzene (bib) with silver(I) nitrate in a 1:1 molar ratio generates the metallacyclic title complex, [Ag2(C12H14N4)2](NO3)2·2H2O, in which the bib ligand displays a cis configuration. Each bib ligand acts as a bidentate bridging ligand connecting a pair of AgI ions to form a [2 + 2] metallamacrocycle in which the Ag⋯Ag distance is 6.77 (2) Å. Each AgI ion has weak contacts (2.91 Å) with the nitrate anion. The uncoordinated water molecules make hydrogen bonds with nitrate O atoms, forming chains. The H atoms attached to the uncoordinated nitrogen interact with these chains through N—H⋯O hydrogen bonds, forming layers parallel to the (11) plane
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