837 research outputs found
Effect of dry heat, microwave and ultrasonic treatments on physicochemical properties of potato starch with or without pectin
Purpose: To investigate the effects of dry heat, microwave and ultrasonic treatments on the physicochemical properties of potato starch alone or blended with pectin.
Methods: The physicochemical properties of potato starch gels prepared using microwave, ultrasonic and dry heat treatments were assessed. Pasting properties, gel strength, thermal properties and crystal texture of the potato starch were determined using Rapid Visco analyzer, texture profile analyzer, differential scanning calorimeter and x-ray diffractometer.
Results: Dry heat and ultrasonic treatments significantly increased the peak viscosity of the potato starch, and significantly decreased its setback and pasting temperatures (p < 0.05). Dry heat treatment significantly increased the hardness, while dry heat and ultrasonic treatments significantly improved retrogradation of the potato starch (p < 0.05). Transparency of potato starch paste was significantly increased by the different treatments, except microwave treatment (p < 0.05). Potato starch gels blended with pectin and subjected to any of the treatments exhibited significantly increased hardness, when compared with raw potato starch (p < 0.05). The retrogradation of the potato starch was significantly improved by the different treatments. Dry heat and ultrasonic treatments significantly decreased the syneresis of potato starch with or without pectin (p < 0.05). The three treatments also significantly affected the gelatinization enthalpy of the potato starch with or without pectin, and exerted some effects on the crystallinity of the gels.
Conclusion: The results obtained in this study suggest that differences in physicochemical properties of potato starch gels are due mainly to the degree of damage to starch granules caused by different treatments. The addition of pectin to potato starch gel greatly improves its hardness and retrogradation
Degradation or excretion of quantum dots in mouse embryonic stem cells
<p>Abstract</p> <p>Background</p> <p>Quantum dots (QDs) have been considered as a new and efficient probe for labeling cells non-invasively in vitro and in vivo, but fairly little is known about how QDs are eliminated from cells after labeling. The purpose of this study is to investigate the metabolism of QDs in different type of cells.</p> <p>Results</p> <p>Mouse embryonic stem cells (ESCs) and mouse embryonic fibroblasts (MEFs) were labeled with QD 655. QD-labeling was monitored by fluorescence microscopy and flow cytometry for 72 hours. Both types of cells were labeled efficiently, but a quick loss of QD-labeling in ESCs was observed within 48 hours, which was not prevented by inhibiting cell proliferation. Transmission electron microscope analysis showed a dramatic decrease of QD number in vesicles of ESCs at 24 hours post-labeling, suggesting that QDs might be degraded. In addition, supernatants collected from labeled ESCs in culture were used to label cells again, indicating that some QDs were excreted from cells.</p> <p>Conclusion</p> <p>This is the first study to demonstrate that the metabolism of QDs in different type of cells is different. QDs were quickly degraded or excreted from ESCs after labeling.</p
(5-Bromo-2-hyÂdroxyÂphenÂyl)(4-propylÂcycloÂhexÂyl)methanone
In the title compound, C16H21BrO2, the cycloÂhexane ring adopts a chair conformation. The hyÂdroxy and carbonyl groups are involved in an intraÂmolecular O—H⋯O hydrogen bond. In the crystal, weak C—H⋯O interÂactions link the molÂecules into zigzag chains along [010]
PHoToNs–A parallel heterogeneous and threads oriented code for cosmological N-body simulation
We introduce a new code for cosmological simulations, PHoToNs, which incorporates features for performing massive cosmological simulations on heterogeneous high performance computer (HPC) systems and threads oriented programming. PHoToNs adopts a hybrid scheme to compute gravitational force, with the conventional Particle-Mesh (PM) algorithm to compute the long-range force, the Tree algorithm to compute the short range force and the direct summation Particle-Particle (PP) algorithm to compute gravity from very close particles. A self-similar space filling a Peano-Hilbert curve is used to decompose the computing domain. Threads programming is advantageously used to more flexibly manage the domain communication, PM calculation and synchronization, as well as Dual Tree Traversal on the CPU+MIC platform. PHoToNs scales well and efficiency of the PP kernel achieves 68.6% of peak performance on MIC and 74.4% on CPU platforms. We also test the accuracy of the code against the much used Gadget-2 in the community and found excellent agreement
Soft Language Clustering for Multilingual Model Pre-training
Multilingual pre-trained language models have demonstrated impressive
(zero-shot) cross-lingual transfer abilities, however, their performance is
hindered when the target language has distant typology from source languages or
when pre-training data is limited in size. In this paper, we propose XLM-P,
which contextually retrieves prompts as flexible guidance for encoding
instances conditionally. Our XLM-P enables (1) lightweight modeling of
language-invariant and language-specific knowledge across languages, and (2)
easy integration with other multilingual pre-training methods. On the tasks of
XTREME including text classification, sequence labeling, question answering,
and sentence retrieval, both base- and large-size language models pre-trained
with our proposed method exhibit consistent performance improvement.
Furthermore, it provides substantial advantages for low-resource languages in
unsupervised sentence retrieval and for target languages that differ greatly
from the source language in cross-lingual transfer
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An Hα Imaging Survey of All (Ultra)luminous Infrared Galaxies at Decl. ≥ -30 in the GOALS Sample
This paper presents the result of Hα imaging for luminous and ultraluminous infrared galaxies. It is a complete subsample of the Great Observatories All-sky LIRG Survey (GOALS) with decl. ≥ -30 , and consists of 148 galaxies with log(L IR/L ) ≥ 11.0. All the Hα images were carried out using the 2.16 m telescope at the Xinglong Station of the National Astronomy Observatories, Chinese Academy of Sciences (NAOC), during the year from 2006 to 2009. We obtained the pure Hα luminosity for each galaxy and corrected the luminosity for [N ii] emission, filter transmission, and extinction. We also classified these galaxies based on their morphology and interaction. We found that the distribution of star-forming regions in these galaxies is related to this classification. As the merging process advanced, these galaxies tended to have a more compact distribution of star-forming regions, higher L IR, and warmer IR-color (f 60/f 100). These results imply that the degree of dynamical disturbance plays an important role in determining the distribution of a star-forming region
Genetic analysis of the Pacific white shrimp (Litopenaeus vannamei): heterosis and heritability for harvest body weight
Heterosis and heritability estimates for the survival of the Pacific white shrimp (Litopenaeus vannamei) under the commercial scale ponds
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