Culture of Differentiated Adult Rabbit Auricular Chondrocytes     

V. Villar  B. Colao  I. Calles‐Venal  J. G. Fernndez‐lvarez  M. Fernndez‐Caso  J. M. Villar 《Anatomia, histologia, embryologia》2005,34(Z1):54-54

Chondrocytes dedifferentiate to a fibroblast‐like phenotype on plastic surfaces. Dedifferentiation is reversible if these cells are then cultured embedded in gels as alginate, agarose or collagen. Chondrocytes cultured in suspension on a non‐adherent surface are also known to form aggregates of differentiated cells. The knowledge of chondrocyte behavior in culture is relevant for tissue engineering purposes. In this report we describe a simple method to culture differentiated or redifferentiated rabbit auricular chondrocytes on plastic surfaces with a stable phenotype. When chondrocyte aggregates formed in suspension are next seeded on plastic surfaces, most of them attach to the plastic as round or polygonal cells, and this morphological differentiation, confirmed by the presence of type II collagen, is stable for long culture periods. We also report that the addition of aggregates to monolayer cultures of dedifferentiated chondrocytes results in their redifferentiation, as is shown by their morphological changes and the synthesis of type II collagen. Therefore, this simple method can be useful for the study of chondrocyte behavior on plastic surfaces and for redifferentiating previously proliferated chondrocytes in tissue engineering techniques. Furthermore, these results demonstrate that, in addition to culture conditions such as cell isolation method or cell‐density, chondrocyte behavior on plastic depends on the presence or absence of aggregates resulting from the dissociation process.  相似文献   

Effect of nutrient solution salinity and ionic concentration on parsley (Petroselinum crispum Mill.) essential oil yield and content     

Juan Eugenio Álvaro  María Teresa Lao  Mourad Baghour  Moumen Abdelmajid 《Journal of plant nutrition》2016,39(8):1057-1062

The growth and essential oil (EO) production of parsley were evaluated in response to salinity and nutrient solution concentrations in a soilless culture. Parsley plants that were 60 days old were potted in a coconut fiber and peat moss medium and were treated with four different nutrient solutions, including T1, T2, T3 and T4. The T1 nutrient solution was the standard, the T2 and T3 solutions contained incremental macronutrient concentrations with an electrical conductivity (EC) of up to 2.2 and 3.2 dS m^?1, respectively, and the T4 solution was the same as T2 but with sodium chloride (NaCl) and an incremental macronutrient concentration with an EC of 3.2 dS m^?1. Next, these plants were grown for 90 days in a greenhouse with natural daylight in Nador, Morocco. Shoot and root growth significant decreased with increasing EC. However, the salinity that resulted from the addition of NaCl did not affect plant growth in the nutrient solutions. The optimum obtained growth and EO production were 1.2 and 2.2 dS m^?1, respectively. Consequently, the optimum EC value (based on the EO production) of parsley in the soilless culture was 1.2–2.2 dS m^?1.  相似文献   

Effect of Density at Harvest on the Growth Performance and Profitability of Hatchery‐reared Spotted Rose Snapper,Lutjanus guttatus,Cultured in Floating Net Cages          下载免费PDF全文

Carlos Humberto Hernández  Crisantema Hernández  Francisco Javier Martínez‐Cordero  Nicolás Castañeda‐Lomas  Guillermo Rodríguez‐Domínguez  Albert G. J. Tacon  Eugenio Alberto Aragón‐Noriega 《Journal of the World Aquaculture Society》2016,47(1):51-60

This study evaluated the effect of the density at harvest on the performance and profitability of hatchery‐reared spotted rose snapper cultured in cages. The fish were stocked at harvest densities of 15, 20, and 22 kg/m³ in cages of 222 and 286 m³. More than 39,000 snapper fingerlings with an initial weight of 14 g were stocked. The fish were fed an extruded diet and cultured over a 360 d period. The thermal growth coefficient ranged from 0.04 to 0.05 and survival was 95% for all treatments, with the highest final weight (436.8 g) observed for fish reared at a density of 20 kg/m³. The allometric value b indicated that hatchery‐raised, cage‐cultured snapper were heavier than their wild counterparts. The major costs were feed (ranging from 44.7–45.9%), labor (22.4–32.6%), and seed costs (20.2–26.1%). The total production cost ranged from US$ 6.5 to US$ 7.5/kg. The baseline scenario was not economically feasible. However, a 10% increase in the sales price resulted in increases in the internal rate of return (183%) and net present value (US$ 97,628.9). These results suggest that L. guttatus has the potential for commercial production in cages.  相似文献   

Comparative study of Kenaf varieties and growing conditions and their effect on kraft pulp quality     

J. C. Villar  P. Poveda  J. L. Tagle 《Wood Science and Technology》2001,34(6):543-552

Kenaf (Hibiscus cannabinus L.) is an annual plant which produces a very high fiber yield per hectare and has demonstrated to be a suitable material for pulping. The crop conditions influence fiber production, but there is no information about their effect on pulp quality. The aim of this work was to study the effect of kenaf varieties and crop conditions (watering dose and harvesting time) on sulfate pulp quality. The study has been made on bast fiber sulfate pulps due to their high added value. The quality criteria were fiber dimensions, chemical composition and pulp quality. Kenaf variety or crop conditions have significant effect on fiber dimensions, holocellulose content, kappa number and breaking strength. To obtain high fiber yield and good delignified pulps it is recommended to grow the Salvador variety and to employ advance harvesting. Received: 20 January 1999  相似文献   

环境条件对杨树花粉生活力的影响   总被引：6，自引：0，他引：6       下载免费PDF全文

杨志敏  马克&#;维拉尔 《林业科学研究》1990,3(4):388-392

花粉生活力的强弱直接关系到杂交育种的成败。在花粉的采集及贮存过程中,许多因素如花枝培养的条件、花粉采集的日期,收粉后的失水时间及含水率,花粉的贮存温度及贮存时间等对花粉的质量和生活力等均具有重要的影响。为了确定这些因素对杨树花粉生活力的  相似文献   

在人工接种和自然感虫情况下美洲黑杨后代对桑天牛抗性的研究   总被引：5，自引：0，他引：5  

胡建军  韩一凡  尹伟伦  Sylvie Augustin  Marc Villar 《林业科学》2002,38(1):164-167

杨树 (Ｐｏｐｕｌｕｓｓｐｐ .)是我国主要造林和工业用材树种之一 ,据统计我国杨树人工林面积达 666×1 0 4ｈｍ2 (王世绩 ,1 995 )。但杨树天牛危害十分猖獗 ,其中光肩星天牛 (Ａｎｏｐｌｏｐｈｏｒａｇｌａｂｒｉｐｅｎｎｉｓ)和黄斑星天牛 (Ａｎｏｐｌｏｐｈｏｒａｎｏｂｉ  相似文献   

Nitrogen form and concentration interact to affect the performance of two ecologically distinct Mediterranean forest trees     

Mercedes Uscola  Juan A. Oliet  Pedro Villar-Salvador  Eugenio Díaz-Pinés  Douglass F. Jacobs 《European Journal of Forest Research》2014,133(2):235-246

Most studies examining inorganic N form effects on growth and nutrition of forest trees have been conducted on single species from boreal or temperate environments, while comparative studies with species from other biomes are scarce. We evaluated the response of two Mediterranean trees of contrasting ecology, Quercus ilex L. and Pinus halepensis Mill., to cultivation with distinct inorganic N forms. Seedlings were fertilized with different NH₄ ⁺/NO₃ ^? proportion at either 1 or 10 mM N. In both species, N forms had small effects at low N concentration, but at high N concentration they markedly affected the plant performance. A greater proportion of NH₄ ⁺ in the fertilizer at high N caused toxicity as it reduced growth and caused seedling death, with the effect being greater in Q. ilex than in P. halepensis. An increase in the proportion of NO₃ ^? at high N strongly enhanced growth relative to low N plants in P. halepensis but had minor effects in Q. ilex. Relatively more NH₄ ⁺ in the fertilizer enhanced plant P concentration but reduced K concentration in both species, while the opposite effect occurred with NO₃ ^?, and these effects were enhanced under high N concentration. We conclude that species responses to inorganic N forms were related to their ecology. P. halepensis, a pioneer tree, had improved performance with NO₃ ^? at high N concentration and showed strong plasticity to changes in N supply. Q. ilex, a late successional tree, had low responsiveness to N form or concentration.  相似文献   

Biosynthetic Modularity Rules in the Bisintercalator Family of Antitumor Compounds     

Javier Fernández  Laura Marín  Raquel álvarez-Alonso  Saúl Redondo  Juan Carvajal  Germán Villamizar  Claudio J. Villar  Felipe Lombó 《Marine drugs》2014,12(5):2668-2699

Diverse actinomycetes produce a family of structurally and biosynthetically related non-ribosomal peptide compounds which belong to the chromodepsipeptide family. These compounds act as bisintercalators into the DNA helix. They give rise to antitumor, antiparasitic, antibacterial and antiviral bioactivities. These compounds show a high degree of conserved modularity (chromophores, number and type of amino acids). This modularity and their high sequence similarities at the genetic level imply a common biosynthetic origin for these pathways. Here, we describe insights about rules governing this modular biosynthesis, taking advantage of the fact that nowadays five of these gene clusters have been made public (thiocoraline, triostin, SW-163 and echinomycin/quinomycin). This modularity has potential application for designing and producing novel genetic engineered derivatives, as well as for developing new chemical synthesis strategies. These would facilitate their clinical development.  相似文献   

QTL mapping of volatile compounds in ripe apples detected by proton transfer reaction-mass spectrometry     

Elena?Zini  Franco?Biasioli  Flavia?Gasperi  Daniela?Mott  Eugenio?Aprea  Tilmann?D.?M?rk  Andrea?Patocchi  Cesare?Gessler  Matteo?KomjancEmail author 《Euphytica》2005,145(3):269-279

The availability of genetic linkage maps enables the detection and analysis of QTLs contributing to quality traits of the genotype. Proton Transfer Reaction Mass Spectrometry (PTR-MS), a relatively novel spectrometric technique, has been applied to measure the headspace composition of the Volatile Organic Compounds (VOCs) emitted by apple fruit genotypes of the progeny ‘Fiesta’ × ‘Discovery’. Fruit samples were characterised by their PTR-MS spectra normalised to total area. QTL analysis for all PTR-MS peaks was carried out and 10 genomic regions associated with the peaks at m/z = 28, 43, 57, 61, 103, 115 and 145 were identified (LOD > 2.5). We show that it is possible to find quantitative trait loci (QTLs) related to PTR-MS characterisation of the headspace composition of single whole apple fruits indicating the presence of a link between molecular characterisation and PTR-MS data. We provide tentative information on the metabolites related to the detected QTLs based on available chemical information. A relation between apple skin colour and peaks related to carbonyl compounds was established. The two authors contributed equally to this work.  相似文献   

Influence of pH and calcium on the growth,polysaccharide production and symbiotic association of<Emphasis Type="Italic"> Sinorhizobium meliloti</Emphasis> SEMIA 116 with alfalfa roots     

Carolina?Delavechia  Eugenio?Hampp  Adriana?Fabra  Stella?CastroEmail author 《Biology and Fertility of Soils》2003,38(2):110-114

The Sinorhizobium -legume interaction is sensitive to a number of environmental factors, soil acidity being one of the most important. In the typic Hapludoll soil of the central-southern region of Córdoba (Argentine) it was found that the nodulation of alfalfa ( Medicago sativaL.) roots was impaired with a reduction in shoot dry matter under conditions of soil acidity (pH 5.5) Our results showed that the addition of lime as dolomitic limestone at a concentration of 1 t ha ^-1to acid soil caused a significant increase in the nodulation of alfalfa roots inoculated with the strain Sinorhizobium meliloti SEMIA 116 (recommended inoculum for alfalfa) in the greenhouse experiments. The success of the lime treatment may be related not only to an increase in the pH values but also to an increase in the Ca concentration, improving the growth of S. meliloti and its nodulation ability under acidic conditions. In this study, we also demonstrated an increment in the bacterial growth rate as well as in the production of exopolysaccharides and lipopolysaccharides under low pH (5.5) and a high Ca concentration (5 mM) in the culture medium.  相似文献