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91.
Iman El Mansouri José A. Mercado Victoriano Valpuesta José M. López-Aranda Fernando Pliego-Alfaro Miguel A. Quesada 《Plant cell reports》1996,15(8):642-646
Summary An efficient and reliable method for shoot regeneration from leaf disks of Fragaria vesca L. has been developed. This protocol has been successfully employed to obtain transformed plants using Agrobacterium tumefaciens as gene vector. Murashige and Skoog basal medium supplemented with benzyladenine (4 mg/l) and indole-3-butyric acid (0.25 mg/l) induced the maximum percentage of shoot regeneration (98%) and the highest number of shoot colonies per explant (4.6) after 8 weeks of culture. Isolated shoots would elongate and proliferate when the benzyladenine concentration was lowered to 0.5 mg/l. The established protocol for shoot regeneration was employed to transform leaf disks using Agrobacterium tumefaciens carrying the plasmid pBI121. A 7.7% of the inoculated explants showed kanamycin resistance after 10 weeks of selection in a medium containing 25 mg/l of this antibiotic. The transgenic shoots obtained were rooted in the presence of 25 mg/ kanamycin and successfully acclimatized. The final percentage of transformation obtained based on beta-glucuronidase expression was 6.9%.Abbreviations BA
benzyladenine
- IBA
indole-3-butyric acid
- MS
Murashige and Skoog basal medium
- LSD
least significant difference
- NOS
nopaline synthase promoter
- NPTII
neomycin phosphotransferase (EC 2.7.1.95)
- CaMV35S
cauliflower mosaic virus promoter
- GUS
beta-glucuronidase (EC 3.2.1.31)
- LB
Luria Broth base
- CTAB
hexadecil trimethyl ammonium bromide
- PCR
polymerase chain reaction
- X-gluc
5-bromo-4-chloro-3-indolyl-glucuronide 相似文献
92.
We investigated the influence of gibberellic acid (GA3; 0, 1, 10, and 100 μM) on Nostoc linckia culture at 7, 14, and 21 days. The fresh and dry weight of N. linckia was increased considerably by the 10 and 100 μM GA3 treatments. A reduction in heterocyst frequency was observed in cultures treated with 1 and 10 μM GA3. Adding GA3 to N. linckia culture had a little effect on cell size. The amount of chlorophyll a and carotenoids decreased at all concentrations of GA3. The amount of phycocyanin increased up to twofold in 7-day-old culture treated with 1 μM GA3, and similar changes were observed for allophycocyanin and phycoerythrin content after 7 days. The effect of GA3 on reducing sugar content was different and was dependent on the growth period. A reduction in soluble sugar content was detected after GA3 application in 7- and 14-day-old cyanobacteria. Cultures treated with GA3 had a higher protein content after 14 days and a lower protein content after 7 and 21 days, and reduced nitrogenase activity after 7, 14, and 21 days. Our data show that GA3 application can be a suitable and inexpensive way to increase N. linckia biomass and phycobiliprotein production. 相似文献
93.
94.
The objective of this article is the design of a prototype allowing the determination of the cardiovascular parameters by a noninvasive method, the peripheral bioimpedance. The prototype is designed with the National Instruments PXI- 7841R data acquisition card, the NI PXI-1033 chassis, the NI SCB-68 connector block and the software of development, LabVIEW with its LabVIEW FPGA module. The core of the PXI-7841R is an FPGA target, the Xilinx Virtex-5 LX30. The configuration of FPGA was not made by VHDL but rather by graphic programming with the LabVIEW FPGA. This module offers the possibility of an easy, sure and fast design. The results of the design are very satisfactory and allowed us to have a completely reconfigurable and evolutionary system fulfilling the electric safety requirements of biomedical equipments. The system allows moreover the determination of several cardiovascular parameters and can be used as vital signs monitor. 相似文献
95.
A Mansouri 《Biochemical medicine and metabolic biology》1989,42(1):43-51
Pure methemoglobin was prepared from fresh red cells and was used as substrate for methemoglobin reduction reaction. Two sources of methemoglobin reductase were used: (a) red cell hemolysate which was prepared by freezing and thawing of unwashed red cells; (b) purified methemoglobin reductase from bank blood. Methemoglobin reduction rate was measured in a mixture of pure methemoglobin (substrate) and hemolysate (enzyme). In other experiments the rate of methemoglobin reduction was measured in the above mixture with the addition of various other compounds such as NADH, cytochrome b5, and pure methemoglobin reductase. Only the addition of pure enzyme accelerated the rate of methemoglobin reduction. In other experiments, the rate of methemoglobin reduction was measured when the reduction reaction was carried out in the presence of various amounts of deoxyhemoglobin, globin, or albumin. It was shown that all proteins tested here decreased the reduction rate. It is concluded that (a) in the red cell, under normal conditions, only the activity of the methemoglobin reductase controls the speed of methemoglobin reduction, and (b) the inhibition of methemoglobin reduction by reduced hemoglobin is mostly nonspecific suggesting a noncompetitive reaction. 相似文献
96.
97.
98.
Soheila Kashanian Mohammad Mehdi Khodaei Hamideh Roshanfekr Ghobad Mansouri 《Molecular biology reports》2014,41(1):25-37
The DNA binding behavior of [Cu(4,7-dmp)(phen-dione)Cl]Cl (1) and [Cu(2,9-dmp)(phen-dione)Cl]Cl (2) where dmp and phen-dion stand for dimethyl-1,10-phenanthroline and 1,10-phenanthroline-5,6-dion, respectively, was studied with a series of techniques including Viscometry, UV–Vis absorption, circular dichroism and fluorescence spectroscopy. Cytotoxicity effect was also investigated. Thermodynamic parameters, enthalpy and entropy changes were calculated according to Van’t Hoff equation, which indicated that both reactions are predominantly enthalpically driven. However, these two complexes show different behavior in fluorescence, circular dichroism and viscometry methods which indicate the Cu(II) complexes interact with calf-thymus DNA by different mode of binding. These have further been verified by competition studies using Hoechst as a distinct groove binder. All these results indicate that these two complexes (1) and (2) interact with CT-DNA via groove binding and partially intercalative mode, respectively and the binding affinity of the complex 1 is higher than that of complex 2. Finally, our findings suggest that the type of ligands and structure of complexes have marked effect on the binding affinity of complexes involving CT-DNA. Also, these new complexes showed excellent antitumor activity against human T lymphocyte carcinoma-Jurkat cell line. 相似文献
99.
100.
A Threshold-based Dynamic Data Replication and Parallel Job Scheduling strategy to enhance Data Grid
N. Mansouri 《Cluster computing》2014,17(3):957-977
Data Grids provide environment for huge, data-intensive applications that produce and process enormous data. Such environments are thus asked to manage data and schedule jobs at the same time. These two important operations have to be tightly coupled to achieve the best results. Replication techniques are widely used to increase the availability of data, improving performance of query latency and load balancing in Data Grid. Also effective resource scheduling is a challenging research issue. In this paper we propose a job scheduling policy, called Parallel Job Scheduling (PJS), and a dynamic data replication strategy, called Threshold-based Dynamic Data Replication (TDDR), to improve the data access efficiencies in a hierarchical Data Grid. The PJS uses hierarchical scheduling to reduce the search time for an appropriate computing node. It considers network characteristics, number of jobs waiting in queue, file locations, and disk read speed of storage drive at data sources. The main idea of TDDR strategy is using a threshold value to determine if the requested replica needs to be copied to the node. The TDDR determines this threshold dynamically based on data request arrival rates and available storage capacities. Then, in order to overcome the problem of limited storage space in each node, we design an efficient replica replacement strategy, which is developed as a two stages process. First, it deletes those files with minimum time for transferring. Second, if space is still insufficient then it considers the last time the replica was requested, number of access, size of replica and file transfer time. Results from the simulation show that our proposed algorithms have better performance in comparison with other algorithms in terms of Mean Job Time, Number of Intercommunications, Number of Replications, Computing Resource Usage, and Effective Network Usage. 相似文献