摘要：
The water-soluble antioxidant, chlorogenic acid, was successfully encapsulated in the low cost-high volume yeast cells for the first time, as characterized by FT-IR spectra and fluorescence micrograph of the yeast cells, chlorogenic acid and microcapsule. The encapsulation efficiency (EE) of yeast cells could be enhanced significantly (P < 0.001) by the treatment of yeast cells with plasmolyser before encapsulation. Also, the release characteristics of the obtained yeast-encapsulated chlorogenic acid were evaluated, and its storage stability as a powder were investigated at 25 degrees C/75% relative humidity (RH), 25 degrees C/90% RH and 60 degrees C. It could be clearly demonstrated that no chemical changes had taken place during the encapsulation, and the yeast-encapsulated chlorogenic acid exhibited a good stability. This study would be helpful to promote the application of chlorogenic acid. The new yeast-cell-based encapsulation protocol may have some general interests for maintaining the stability of other water-soluble substances. (c) 2006 Elsevier Ltd. All rights reserved.
摘要：
In this paper, we consider the n-order neutral delay differential equation with unstable type ((x(t) - p(t)x(t - tau))((n)) = q(t)vertical bar x(t - sigma)vertical bar(alpha-1)x(t - sigma), t >= t(0), where n >= 2 is an even integer, alpha >= 1, tau > 0, sigma > 0 and p, q is an element of C([t(0), +infinity], R+). We first prove that this equation always has an unbounded positive solution, then some new bounded oscillation and nonoscillation criteria are obtained. (c) 2005 Elsevier Inc. All rights reserved.
作者机构：
[Chen, AP] Department of Mathematics, Xiangnan College, Chenzhou, Hunan 423000, China;[Zhou, TJ; Liu, YR] School of Mathematics, Central South University, Changsha, Hunan 410083, China;[Zhou, TJ] College of Science, Hunan Agricultural University, Changsha, Hunan 410128, China
通讯机构：
[Zhou, TJ ] ;Cent S Univ, Sch Math, Changsha 410083, Hunan, Peoples R China.
关键词：
almost periodic solution;global exponential stability;Halanay;inequality;shunting inhibitory cellular neural networks
摘要：
In this paper, a class of two-dimensional shunting inhibitory cellular neural networks with time-varying delays and variable coefficients as following system $$ \frac{{d}x_{ij}}{{d}t}=L_{ij}(t)-a_{ij}(t)x_{ij}-\sum_{C_{kl}\in N_r(i,j)}c_{ij}^{kl}(t)f_{kl}(x_{kl}(t-\tau_{kl}(t)))x_{ij}$$ is studied, which every cell has its own signal transmission function. We obtain two sufficient conditions about existence of a unique almost periodic solution for the system by way of exponential dichotomy and the Banach fixed point theorem, and point out the utilization occasion of every condition. Moreover, we prove that the almost periodic solution is global exponential stability by using of Halanay inequality. Two examples are given to illustrate that the criterion are feasible.
期刊：
Computational and Theoretical Chemistry,2005年724(1-3):81-86 ISSN：2210-271X
通讯作者：
Zeng, Y
作者机构：
[Zeng, Y] Hunan Normal Univ, Coll Chem & Chem Engn, Minist Educ, Key Lab Chem Biol & Trad Chinese Med Res, Changsha 410081, Hunan, Peoples R China.;Hunan Agr Univ, Dept Chem, Changsha 410128, Peoples R China.;Hunan Univ Arts & Sci, Dept Chem, Hunan 415000, Changde, Peoples R China.;Univ N Carolina, Dept Acad Technol & Networks, Chapel Hill, NC 27599 USA.
通讯机构：
[Zeng, Y] H;Hunan Normal Univ, Coll Chem & Chem Engn, Minist Educ, Key Lab Chem Biol & Trad Chinese Med Res, Changsha 410081, Hunan, Peoples R China.
关键词：
density functional calculations;hypophosphite;nickel;copper;adsorption
摘要：
Surface structures and electronic properties of hypophosphite, H2PO2-, molecularly adsorbed on Ni(111) and Cu(111) surfaces were investigated using B3LYP density functional theory. Geometry and orientation of H2PO2- were fully optimized on the metal clusters and six and four stable structures were obtained on Ni(111) and Cu(111) surfaces, respectively. The most stable structures were that H2PO2- is absorbed with its two P-O bonds in faced to the substrate surface and with 0 atoms in bridge sites. The adsorption energy was more larger on the Ni surface than on the Cu surface. The results of the Mulliken population analysis showed that the donation from lone pair of O atom in H2PO2- to substrate and the 4s back donation from substrate to H2PO2- sigma* play very important roles in the adsorption, and that the amounts of both donation and back donation were larger on the Ni surface than on the Cu surface. There were more negative Mulliken charge transfers from H2PO2- to substrate clusters on Ni substrate clusters than on Cu substrate clusters and were more positive Mulliken charges on P atom in Ni4H2PO2- than in Cu4H2PO2-, which means that P atom in Ni4H2PO2- are easily attacked by nucleophile such as OH-, and farther H2PO2- were more easily oxidated on Ni substrate than on Cu substrate. (c) 2005 Elsevier B.V. All rights reserved.
摘要：
By using the continuation theorem of coincidence degree theory and Liapunov function, we obtain some sufficient criteria to ensure the existence and global exponential stability of periodic solution to the bidirectional associative memory (BAM) neural networks with periodic coefficients and continuously distributed delays. These results improve and generalize the works of papers [J. Cao, L. Wang, Phys. Rev. E 61 (2000) 1825] and [Z. Liu, A. Chen, J. Cao, L. Huang, IEEE Trans. Circuits Systems 150 (2003) 1162]. An example is given to illustrate that the criteria are feasible. (c) 2005 Elsevier B.V. All rights reserved.
摘要：
The expression of Arabidopsis PDF1.2 gene isregulated by jasmonic acid (JA) and ethylene (ET). It also has been well documented that GCC box is an element responsive to ET, however, the responsive mechanism of JA in such plant defense gene expression is unclear. In this paper, the authors define the essential cis-acting element in PDF1.2 promoter responsive to methyl jasmonate (MeJA) through fragment deletions and site-directed mutageneses combiningAgrobacterium-mediated transient reporter gene expression in tobacco leaves. Firstly, the MeJA inducible expression o fPDF1.2 was confirmed by using the upstream -1.86 kb fragment of PDFI.2 gene. Secondly, the upstream -300— -243 bp fragment of the promoter was evidenced to respond to MeJA. To further characterize this promoter region, three point mutations were introduced into the -300— -243 bp fragment of the promoter. This result showed that the mutation of GCC box abolished MeJA induction, whereas the mutations of the G box-like and the imperfect palindrome sequence did not significantly decrease MeJA inducible effect, indicating that GCC box in PDFI.2 is essential for MeJA induction. The sufficient responsiveness to MeJA of this GCC box was further investigated by 4xGCC fused upstream to the CaMV 35S minimal promoter. This result suggested that the fused promoter was able to activate reporter gene expression in response to MeJA. Thus these results indicate that the GCC box in PDFI.2 is an essential and sufficient element to confer MeJA induction.
摘要：
Crop researchers often store ground plant tissue samples for considerable time before determining their nitrogen (N) concentration. The objective of this study was to determine the effects of storage methods and storage duration on total N analysis in rice leaves. The storage methods investigated were (1) keeping ground leaf tissue in a paper bag, (2) storage in a bottle with additional drying at 70°C for 24h, or (3) in a bottle without additional drying. Paper bags and sealed bottles were kept under ambient condition. Leaf N concentration was measured about once a month for two years by micro-Kjeldahl method. Storage methods had little effect on leaf N concentration during the two-year storage period. The difference in leaf N concentration was 0.1-0.2gkg-1 between the samples stored in paper bags and in bottles, which was less than 0.5% of mean value of leaf N concentration. Leaf N concentration was not affected over the two-year storage duration. These results suggest that it is sufficient to keep plant tissue samples in paper bags under ambient condition for at least two years for measurement of leaf N concentration.
摘要：
β-ocimene, a kind of monoterpene, was found recently as a plant communication signal molecule. It has two isomeric forms in nature: cis-β-ocimene and trans-β-ocimene. According to recent reports, all investigated plants, such as corn, cotton, lima bean, potato, tobacco, arabidopsis, and Mediterranean pine, could release the chemical component β-ocimene after fed by arthropod herbivores,
摘要：
Six chlorophyll meters (SPAD) were compared to determine the magnitude of differences in SPAD readings on rice leaves. Correlations among the six SPAD meters were statistically significant (P<0.01) with correlation coefficients (r) ranging from 0.971 to 0.990. However, the differences in SPAD readings were statistically significant among the six meters (P<0.05) and the difference between two meters was as large as 2.7 units. Such magnitudes of discrepancy should be considered when different SPAD meters are used in the same study.
摘要：
The deactivation of nickel hydroxide to the electrooxidation of hypophosphite on a nickel electrode was studied by means of in situ UV-Vis subtractive reflectance spectroscopy. The experimental results show that when the potential is lower than -1.0 V (SCE), the surface on nickel electrode is free of nickel hydroxide, on which hypophosphite is active. When the potential moves positively to about -0.75V, two absorbency bands around 300 nm and 550 nm, which were ascribed to the formation of α-nickel hydroxide, were observed, nickel is oxidized to α-nickel hydroxide. Severe deactivation of the surface occurs when the nickel surface is covered with nickel hydroxide, which separates the hypophosphite ion from nickel substrate.
期刊：
JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS,1999年42(2):199-201 ISSN：0362-4803
通讯作者：
Tang, GH
作者机构：
Peking Union Med Coll Hosp, Chinese Acad Med Sci, Dept Nucl Med, Beijing 100730, Peoples R China.;Hunan Agr Univ, Dept Appl Chem, Changsha 410128, Peoples R China.;[Tang, GH] First Mil Univ, Nan Feng Hosp, Dept Nucl Med, Guangzhou 510516, Peoples R China.
通讯机构：
[Tang, GH] F;First Mil Univ, Nan Feng Hosp, Dept Nucl Med, Guangzhou 510516, Peoples R China.
