1,965 research outputs found
Fragmentation function of in soft gluon factorization and threshold resummation
We study the fragmentation function of the gluon to color-octet heavy
quark-antiquark pair using the soft gluon factorization (SGF) approach, which
expresses the fragmentation function in a form of perturbative short-distance
hard part convoluted with one-dimensional color-octet soft gluon
distribution (SGD). The short distance hard part is calculated to
next-to-leading order in and a renormalization group equation for
the SGD is derived. By solving the renormalization group equation, threshold
logarithms are resummed to all orders in perturbation theory. The comparison
with gluon fragmentation function calculated in NRQCD factorization approach
indicates that the SGF formula resums a series of velocity corrections in NRQCD
which are important for phenomenological study.Comment: 38 pages, 8 figure
New symmetries for the Ablowitz-Ladik hierarchies
In the letter we give new symmetries for the isospectral and non-isospectral
Ablowitz-Ladik hierarchies by means of the zero curvature representations of
evolution equations related to the Ablowitz-Ladik spectral problem. Lie
algebras constructed by symmetries are further obtained. We also discuss the
relations between the recursion operator and isospectral and non-isospectral
flows. Our method can be generalized to other systems to construct symmetries
for non-isospectral equations.Comment: 11 page
Plastic Responses in Growth, Morphology, and Biomass Allocation of Five Subtropical Tree Species to Different Degrees of Shading
We investigated how different degrees of shading affected growth, morphology, and biomass allocation in seedlings from two coniferous and three broadleaved species. The experiment was conducted in a shade house over a 1-year period. Our results showed that under increasing shade, seedlings from most species exhibited lower total biomass, net assimilation rates, relative growth rates, root mass ratios, and root/shoot ratios. In contrast, the slenderness quotients, leaf area ratios, and specific leaf areas increased with increasing shade. For coniferous species, growth traits were relatively more plastic (responsive to shade) than morphology or biomass allocation traits, whereas for broadleaved species, growth and biomass allocation were the most shade-sensitive traits. When comparing coniferous versus broadleaved species, the former had a higher growth plasticity index and lower allocation plasticity than the latter. Root biomass and stem mass ratio were the most and least plastic traits in response to shading. Our results indicate that shade differentially affects coniferous and broadleaved species in terms of their growth, morphology, and biomass allocation. These findings have important implications for the establishment and maintenance of mixed-species stands
Online Inertia Estimation Using Electromechanical Oscillation Modal Extracted from Synchronized Ambient Data
Synthetic θ‐Defensin Antibacterial Peptide as a Highly Efficient Nonviral Vector for Redox‐Responsive miRNA Delivery
Synthetic cationic vectors have shown great promise for nonviral gene delivery. However, their cytotoxicity and low efficiency impose great restrictions on clinic applications. To push through this limitation, humanized peptides or proteins with cationic biocompatibility as well as biodegradation would be an excellent candidate. Herein, for the first time, we describe how an arginine‐rich humanized antimicrobial cyclopeptide, θ‐defensin, can be used as a synthetic cationic vector to load and deliver miRNA into bone mesenchymal stem cells with high efficiency and ultralow cytotoxicity, surpassing the efficiency of the commercial polyethylenimine (25 kD) and Lipofectamine 3000. To note, θ‐defensin can redox‐responsively release the loaded miRNA through a structural change: in extracellular oxidative environment, θ‐defensin has large β‐sheet structures stabilized by three disulfide linkages, and this special structure enables highly efficient delivery of miRNA by passing through cell membranes; in intracellular environment, redox‐responsive disulfide linkages are broken and the tight β‐sheet structures are destroyed, so that the miRNA can be released. Our results suggest that synthetic θ‐defensin peptides are a new class of nonviral gene vectors and this study may also provide a promising strategy to design smart‐responsive gene vectors with high efficiency and minimal toxicity.This study describes how an arginine‐rich humanized antimicrobial cyclopeptide, θ‐defensin, can be used as a synthetic cationic vector to load and deliver miRNA into bone mesenchymal stem cells with high efficiency and low cytotoxicity, surpassing the efficiency of the commercial polyethylenimine (25 kD) and Lipofectamine 3000.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/1/adbi201700001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/2/adbi201700001_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141894/3/adbi201700001-sup-0001-S1.pd
Phenotypic Plasticity of Cunninghamia lanceolata (Lamb.) Hook. Seedlings in Response to Varied Light Quality Treatments
Effects of light quality on phenotypic plasticity in Cunninghamialanceolata (Lamb.) Hook. seedlings during growth and development, and the underlying mechanisms, were investigated. The seedlings showed distinct morphological adjustments when exposed to an equal photosynthetic photon flux density (400 mu mol.m(-2).s(-1)) of different light qualities: monochromatic blue (BL), monochromatic red (RL), monochromatic far-red (FrL), mixed RL and FrL at 1:1 (RFr1:1L), mixed RL and FrL at 1:2 (RFr1:2L), and multi-wavelength white (WL, control). Compared with WL, FrL and BL significantly promoted height increment. However, BL was unfavorable for root growth. The seedling biomass was lower and the root-to-shoot ratio was smaller under BL. RL promoted leaf area enlargement, root growth, axillary bud number, and increased the root-to-shoot ratio, but inhibited stem elongation. Low R/Fr ratios or increased FrL proportion increased seedling stem elongation. The seedling growth under RFr1:1L treatment was poorer than that under other treatments; however, the number of axillary buds was the highest. The plasticity of leaf morphology traits was lower in different treatments, and that of axillary bud traits was crucial in the adaptation of C. lanceolata to light quality. Precise management of light quality and wavelength in controlled environments may maximize the economic efficiency of forest production and enhance its quality
Corneal optical density: Structural basis, measurements, influencing factors, and roles in refractive surgery
The cornea is the main refractive medium of the human eye, and its clarity is critical to visual acuity. Corneal optical density (COD) is an important index to describe corneal transparency. Intact corneal epithelial and endothelial cells, regular arrangement of collagen fibers in the stroma, and normal substance metabolism are all integral for the cornea to maintain its transparency. In the last two decades, the Pentacam Scheimpflug imaging system has emerged as a breakthrough for the measurement of COD (also called corneal densitometry). It has been found that a wide variety of factors such as age, refractive status, and corneal diseases can affect COD. Different corneal refractive surgery methods also change COD in different corneal regions and layers and affect visual acuity following the surgery. Thus, COD has gradually become a significant indicator to evaluate corneal health, one on which the attention of clinicians has been increasingly focused
Development and Validation of an RNA-Seq-Based Prognostic Signature in Neuroblastoma
Objective: The stratification of neuroblastoma (NBL) prognosis remains difficult. RNA-based signatures might be able to predict prognosis, but independent cross-platform validation is still rare.
Methods: RNA-Seq-based profiles from NBL patients were acquired and then analyzed. The RNA-Seq prognostic index (RPI) and the clinically adjusted RPI (RCPI) were successively established in the training cohort (TARGET-NBL) and then verified in the validation cohort (GSE62564). Survival prediction was assessed using a time-dependent receiver operating characteristic (ROC) curve and area under the ROC curve (AUC). Functional enrichment analysis of the genes was conducted using bioinformatics methods.
Results: In the training cohort, 10 gene pairs were eventually integrated into the RPI. In both cohorts, the high-risk group had poor overall survival (OS) (P < 0.001 and P < 0.001, respectively) and favorable event-free survival (EFS) (P = 0.00032 and P = 0.06, respectively). ROC curve analysis also showed that the RPI predicted OS (60 month AUC values of 0.718 and 0.593, respectively) and EFS (60 month AUC values of 0.627 and 0.852, respectively) well in both the training and validation cohorts. Clinicopathological indicators associated with prognosis in the univariate and multivariate regression analyses were identified and added to the RPI to form the RCPI. The RCPI was also used to divide populations into different risk groups, and the high-risk group had poor OS (P < 0.001 and P < 0.001, respectively) and EFS (P < 0.05 and P < 0.05, respectively). Finally, the RCPI had higher accuracy than the RPI for the prediction of OS (60 month AUC values of 0.730 and 0.852, respectively) and EFS (60 month AUC values of 0.663 and 0.763, respectively) in both the training and validation cohorts. Moreover, these differentially expressed genes may be involved in certain NBL-related events.
Conclusions: The RCPI could reliably categorize NBL patients based on different risks of death
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