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81.
L. H. Wu Y. J. Liu S. B. Zhou F. G. Guo D. Bi X. H. Guo A. J. M. Baker J. A. C. Smith Y. M. Luo 《Plant Systematics and Evolution》2013,299(3):487-498
Sedum plumbizincicola X.H. Guo et S.B. Zhou ex L.H. Wu (Crassulaceae), a new species restricted to lead–zinc mining areas in Zhejiang Province, China, is described and illustrated. This taxon belongs to sect. Sedum (H. Ohba) S.H. Fu based on the adaxially gibbous carpels and follicles. It superficially resembles S. alfredii Hance and three other Sedum species found in the same area, but differs from these other taxa in bearing 4-merous flowers. Differences in geographical distribution, growth habit, phenology, macromorphology, leaf and stem anatomy, as well as seed micromorphology among S. plumbizincicola, S. alfredii and other related taxa in the genus Sedum are also reported. nrDNA internal transcribed spacers (ITS) sequences from seven populations of S. plumbizincicola support the recognition of this as a taxonomic entity distinct from S. alfredii. 相似文献
82.
In this article, surface coatings derived from homo-bifunctional tri(ethylene glycol) (EG3) and hexa(ethylene glycol) (EG6) molecules which have two terminal aldehyde groups are reported. These homo-bifunctional molecules can be used to functionalize amine-terminated surfaces through crosslinking one aldehyde group to surface amine groups, while leaving the other aldehyde group available for covalent immobilization of proteins. Best of all, after reducing remaining aldehyde groups on the surface with a reducing agent, sodium borohydride, the surface becomes oligo(ethylene glycol) (OEG)-terminated. The OEG-terminated surface can resist nonspecific protein adsorption, a feature that is often required for many biosensors and biomedical devices. Although some mixed self-assembled monolayers formed from two different organothiols also permit covalent protein immobilization and resist nonspecific protein adsorption, the procedure reported herein requires only one type of homo-bifunctional molecule and can be applied to both silicon and gold surfaces. 相似文献
83.
84.
Huahua Wang Junjun Huang Weihong Liang Xiaolei Liang Yurong Bi 《Plant and Soil》2013,366(1-2):479-490
Background and Aims
Polyamines and nitric oxide (NO) are two important molecules modulating numerous environment stresses in plants. This study was to investigate the roles of polyamines and NO in aluminum (Al) tolerance in red kidney bean.Methods
The interaction between putrescine (Put) and NO under Al stress was examined. NO donor and scavenger were used to further examine the role of NO in Al-induced citrate secretion from roots by high performance liquid chromatography.Results
Al stress caused increase of endogenous free Put, and exogenous Put alleviated Al-induced inhibition of root elongation and Al accumulation. In addition, Put induced NO production and nitrate reductase (NR) activity under Al stress. Al- and Put-induced NO production could be reversed by NR inhibitor. Furthermore, Al stress stimulated citrate secretion from roots, and this response was stimulated by NO donor, whereas NO scavenger inhibited Al-induced citrate secretion from roots. Concomitantly, NO donor reduced Al accumulation in root apexes, while NO scavenger further enhanced Al accumulation. Al-induced inhibition of root growth was significantly improved by exogenous citrate treatment.Conclusions
Put and NO enhanced Al tolerance by modulating citrate secretion from roots, and NO may act downstream of Put in red kidney bean under Al stress. 相似文献85.
Faming Wang Weixing Zhu Bi Zou Deborah A. Neher Shenglei Fu Hanping Xia Zhian Li 《Plant and Soil》2013,364(1-2):207-218
Background and aims
The relationship between tree species and soil nutrient availability is critical for evaluating plantation succession and promoting forest restoration. This study was conducted to evaluate the impact of exotic and native tress species on soil nutrient availability.Methods
Four exotic species (Eucalyptus urophylla, E. tereticornis, Acaia auriculaeformis, A. mangium) and four native species (Castanopsis fissa, Schima superba, C. hystrix, Michelia macclurei) were planted and grown for one-year. Soil solution (DOC, DON, NH4?N, NO3?N) was sampled and analyzed during the study. After the experiment, soil properties were determined, and plant tissues were analyzed.Results
DOC levels were greater in soils with trees planted than controls without trees. Compared to native species, exotic species had much faster growth rates and greatly reduced DON and NO3?N concentrations. Exotic species always had less P concentrations in leaves and stems than native species. Furthermore, N-fixing A. auriculaeformis led to greater soil available P compared to other species.Conclusions
Based on these findings, we provide some recommendations for afforestation practice. This study highlights that a better understanding of the pros and cons of exotic species would be beneficial to advance afforestation in China and the world. 相似文献86.
Multiphasic triacylglycerol dynamics in the intact heart during acute in vivo overexpression of CD36
Andrew N. Carley Jian Bi Xuerong Wang Natasha H. Banke Jason R. B. Dyck J. Michael O'Donnell E. Douglas Lewandowski 《Journal of lipid research》2013,54(1):97-106
Cardiac triacylglycerol (TAG) stores buffer the intracellular availability of long chain fatty acid (LCFA) that act as nuclear receptor ligands, substrate for lipotoxic derivatives, and high energy-yield fuel. The kinetic characteristics of TAG turnover and homeostatic mechanisms linking uptake and storage dynamics in hearts have until now remained elusive. This work examines TAG pool dynamics in the intact beating heart, under normal conditions and in response to acute gene expression-induced changes in CD36. Dynamic mode 13C NMR elucidated multiple kinetic processes in 13C-palmitate incorporation into TAG: an initial, saturable exponential component and a slower linear rate. Although previous work indicates the linear component to reflect TAG turnover, we hypothesized the saturable exponential to reflect transport of LCFA across the sarcolemma. Thus, we overexpressed the LCFA transporter CD36 through cardiac-specific adenoviral infection in vivo. Within 72 h, CD36 expression was increased 40% in intact hearts, accelerating the exponential phase relative to PBS-infused hearts. TAG turnover also increased with elevations in adipose triglyceride lipase (ATGL) and a modest increase in diacylglycerol acyltransferase 1 (DGAT1), without a significant expansion of the intracellular lipid pools. The results demonstrate a dynamic system of reciprocal gene regulation that couples saturable LCFA uptake across the sarcolemma to TAG synthesis/lipolysis rates. 相似文献
87.
88.
Ruifei Wang Jiajia Bi Khamal Kwesi Ampah Xueqing Ba Wenguang Liu Xianlu Zeng 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2013,1833(12):3195-3205
Tumor cell migration is a crucial step in the metastatic cascade, and interruption of this step is considered to be logically effective in preventing tumor metastasis. Lipid rafts, distinct liquid ordered plasma membrane microdomains, have been shown to influence cancer cell migration, but the underlying mechanisms are still not well understood. Here, we report that lipid rafts regulate the dynamics of actin cytoskeleton and focal adhesion in human melanoma cell migration. Disrupting the integrity of lipid rafts with methyl-β cyclodextrin enhances actin stress fiber formation and inhibits focal adhesion disassembly, accompanied with alterations in cell morphology. Furthermore, actin cytoskeleton, rather than microtubules, mediates the lipid raft-dependent focal adhesion disassembly by regulating the dephosphorylation of focal adhesion proteins and the internalization of β3 integrin. We also show that Src–RhoA–Rho kinase signaling pathway is responsible for lipid raft disruption-induced stress fiber formation. Taken together, these observations provide a new mechanism to further explain how lipid rafts regulate the migration of melanoma cell and suggest that lipid rafts may be novel and attractive targets for cancer therapy. 相似文献
89.
Xiuling Li Pavel Přibyl Kateřina Bišová Shigeyuki Kawano Vladislav Cepák Vilém Zachleder Mária Čížková Irena Brányiková Milada Vítová 《Biotechnology and bioengineering》2013,110(1):97-107
The alga Parachlorella kessleri, strain CCALA 255, grown under optimal conditions, is characterized by storage of energy in the form of starch rather than lipids. If grown in the complete medium, the cultures grew rapidly, producing large amounts of biomass in a relatively short time. The cells, however, contained negligible lipid reserves (1–10% of DW). Treatments inducing hyperproduction of storage lipids in P. kessleri biomass were described. The cultures were grown in the absence or fivefold decreased concentration of either nitrogen or phosphorus or sulfur. Limitation by all elements using fivefold or 10‐fold diluted mineral medium was also tested. Limitation with any macroelement (nitrogen, sulfur, or phosphorus) led to an increase in the amount of lipids; nitrogen limitation was the most effective. Diluted nutrient media (5‐ or 10‐fold) were identified as the best method to stimulate lipid overproduction (60% of DW). The strategy for lipid overproduction consists of the fast growth of P. kessleri culture grown in the complete medium to produce sufficient biomass (DW more than 10 g/L) followed by the dilution of nutrient medium to stop growth and cell division by limitation of all elements, leading to induction of lipid production and accumulation up to 60% DW. Cultivation conditions necessary for maximizing lipid content in P. kessleri biomass generated in a scale‐up solar open thin‐layer photobioreactor were described. Biotechnol. Bioeng. 2013; 110: 97–107. © 2012 Wiley Periodicals, Inc. 相似文献
90.
Özlem Biçen Ünlüer Arzu Ersöz Ridvan Say Özlem Tomsuk Hülya Sivas 《Biotechnology progress》2013,29(2):472-479
This study describes preparation and use of novel labeled and antibodious polymeric nanolabels (anti‐alpha fetoprotein cross‐linked nanolabels) as an immunogenic and semisynthetic nanolabel with potential prognostic and therapeutic roles for hepatoma cancer. Specificity, uptake, and binding efficiencies of the nanolabel have been examined in a human hepatosarcoma cell line HepG2, a human colorectal cell line DLD‐1, and a mouse myoblast cell line C2. Labeling of the cells has been performed by treating live and fixed cells with varying concentrations of the nanolabels and then, the cells have been examined under a fluorescence microscope. In addition, all cell lines have also been labeled using FITC‐conjugated nanotrastuzumab to compare the results obtained with those of the binding of the FITC‐nanoanti‐alpha fetoprotein nanolabels. Results show that FITC‐conjugated anti‐alpha fetoprotein cross‐linked nanolabels have been taken up by both live and fixed cells and have efficiently and specifically labeled HepG2 cells at a quite low concentration. Taken all together, the results indicate that the novel targeted nanoimaging tools and technique demonstrated their ability to detect the distribution of the nanolabels as probes in hepatoma cells. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 472–479, 2013 相似文献