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51.
OUTLINING ETHICAL ISSUES IN NANOTECHNOLOGIES 总被引:1,自引:0,他引:1
Nanotechnologies are an expression of the human ability to control and manipulate matter on a very small scale. Their use will enable an even and constant monitoring of human organisms, in a new and perhaps less invasive way. Debates at all levels – national, European and international – have pointed out the common difficulty of giving a complete, clear definition of nanotechnologies. This is primarily due to the variety of their components, to the fact that there is not just one technology but several.
The most significant medical applications of nanotechnologies are in the diagnostic and the therapeutic fields, eg biosensors and molecular imaging, providing diagnosis and drug delivery with no invasive methods involved.
Like any other emerging field, such technologies imply new possibilities for improving health but, on the other hand, they are still at an experimental stage and therefore should be implemented under rigorous safety testing before going on general release. For this purpose, the ethical, legal and social implications (ELSI) of nanotechnologies have been elaborated by study groups, in order to develop solutions before the results of the tests are diffused into medical practice.
The aim of this paper is to define some of the ethical issues concerning biomedical applications and to evaluate whether there is a need for new or additional guidelines and regulations. 相似文献
The most significant medical applications of nanotechnologies are in the diagnostic and the therapeutic fields, eg biosensors and molecular imaging, providing diagnosis and drug delivery with no invasive methods involved.
Like any other emerging field, such technologies imply new possibilities for improving health but, on the other hand, they are still at an experimental stage and therefore should be implemented under rigorous safety testing before going on general release. For this purpose, the ethical, legal and social implications (ELSI) of nanotechnologies have been elaborated by study groups, in order to develop solutions before the results of the tests are diffused into medical practice.
The aim of this paper is to define some of the ethical issues concerning biomedical applications and to evaluate whether there is a need for new or additional guidelines and regulations. 相似文献
52.
ANTONIO E PIPOLO THOMAS R SINCLAIR GIL M S CAMARA 《The Annals of applied biology》2004,144(2):223-227
Oil and protein are the most valuable components of soybean seed. Evidence indicates that growth and composition of soybean seed are controlled by supplies of carbon and nitrogen provided by the maternal plant to the seed, but it is difficult experimentally to control and quantify the precise amount of carbon and nitrogen provided to the seed by the whole plant. To examine whether oil and protein concentrations are affected by the supply of nitrogen to the seed, immature soybean seeds (Glycine max cv. Williams 82) were grown in vitro in nutrient solutions containing 20, 40, 60 or 80 mM of glutamine. The seeds were incubated in Erlenmeyer flasks for 8 days at 25°C. The rate of dry matter accumulation changed from 7.2 to 8.3 mg seed−1 day−1 as the glutamine concentration increased from 20 to 80 mM but the differences were not significant (P 0.05). Seed protein concentration increased as glutamine concentration increased from 294 mg g−1 at 20 mM glutamine to as high as 445 mg g−1 at 80 mM glutamine. Typical in vivo protein concentration of mature soybean seeds is about 400 mg g−1. Oil and protein concentrations were negatively correlated (r2= 0.44), which indicates that oil and protein synthesis are interrelated. Protein synthesis was favoured over oil synthesis when nitrogen became more abundant. The seeds used in this study clearly demonstrated a capacity to respond to nitrogen availability with changes in seed protein concentration. 相似文献
53.
PILAR DELGADO M. ROSARIO ROMERO ANTONIO TORRES 《The Journal of eukaryotic microbiology》1990,37(3):182-186
The pattern of cytospindle assembly and the modifications of the microtubular cytoplasmic network during division of Paramecium are studied by means of indirect immunofluorescence. The assembly of cytospindle starts at two independent areas placed respectively around the proter's and opisthe's buccal overture. The moment of the microtubule bundles’appearance depends on their distance from the buccal opening, with those closest appearing 1st. The existence of microtubule organizing centers that act transiently during division of Paramecium is discussed. 相似文献
54.
ANTONIO JESÚS SERRATO ELENA MARÍA YUBERO-SERRANO LUISA MARÍA SANDALIO JUAN MUÑOZ-BLANCO ANA CHUECA JOSÉ LUIS CABALLERO & MARIAM SAHRAWY 《Plant, cell & environment》2009,32(7):811-827
A full-length FBPase cDNA has been isolated from Fragaria × ananassa (strawberry) corresponding to a novel putative chloroplastic FBPase but lacking the regulatory redox domain, a characteristic of the plastidial isoenzyme (cpFBPaseI). Another outstanding feature of this novel isoform, called cpFBPaseII, is the absence of the canonical active site. Enzymatic assays with cpFBPaseII evidenced clear Mg2+ -dependent FBPase activity and a K m for fructose-1,6-bisphosphate (FBP) of 1.3 m m . Immunolocalization experiments and chloroplast isolation confirmed that the new isoenzyme is located in the stroma. Nevertheless, unlike cpFBPaseI, which is redox activated, cpFBPaseII did not increase its activity in the presence of either DTT or thioredoxin f (TRX f ) and is resistant to H2 O2 inactivation. Additionally, the novel isoform was able to complement the growth deficiency of the yeast FBP1 deletion fed with a non-fermentable carbon source. Furthermore, orthologues are restricted to land plants, suggesting that cpFBPaseII is a novel and an intriguing chloroplastic FBPase that emerged late in the evolution of photosynthetic organisms, possibly because of a pressing need of land plants. 相似文献
55.
MANUEL SÁNCHEZ LÓPEZ-BERGES ANTONIO DI PIETRO MARIE-JOSÉE DABOUSSI HALA ABDEL WAHAB CHRISTELLE VASNIER M. ISABEL G. RONCERO MARIE DUFRESNE CONCEPCIÓN HERA 《Molecular Plant Pathology》2009,10(1):95-107
Forward genetic screens are efficient tools for the dissection of complex biological processes, such as fungal pathogenicity. A transposon tagging system was developed in the vascular wilt fungus Fusarium oxysporum f. sp. lycopersici by inserting the novel modified impala element imp160::gfp upstream of the Aspergillus nidulans niaD gene, followed by transactivation with a constitutively expressed transposase. A collection of 2072 Nia+ revertants was obtained from reporter strain T12 and screened for alterations in virulence, using a rapid assay for invasive growth on apple slices. Seven strains exhibited reduced virulence on both apple slices and intact tomato plants. Five of these were true revertants showing the re-insertion of imp160::gfp within or upstream of predicted coding regions, whereas the other two showed either excision without re-insertion or no excision. Linkage between imp160::gfp insertion and virulence phenotype was determined in four transposon-tagged loci using targeted deletion in the wild-type strain. Knockout mutants in one of the genes, FOXG_00016 , displayed significantly reduced virulence, and complementation of the original revertant with the wild-type FOXG_00016 allele fully restored virulence. FOXG_00016 has homology to the velvet gene family of A. nidulans . The high rate of untagged virulence mutations in the T12 reporter strain appears to be associated with increased genetic instability, possibly as a result of the transactivation of endogenous transposable elements by the constitutively expressed transposase. 相似文献
56.
The powdery mildew fungus Podosphaera fusca (synonym Podosphaera xanthii), a constant threat to cucurbits 总被引:2,自引:0,他引:2
ALEJANDRO PÉREZ-GARCÍA DIEGO ROMERO DOLORES FERNÁNDEZ-ORTUÑO FRANCISCO LÓPEZ-RUIZ ANTONIO DE VICENTE JUAN A. TORÉS 《Molecular Plant Pathology》2009,10(2):153-160
Numerous vegetable crops are susceptible to powdery mildew, but cucurbits are arguably the group most severely affected. Podosphaera fusca (synonym Podosphaera xanthii ) is the main causal agent of cucurbit powdery mildew and one of the most important limiting factors for cucurbit production worldwide. Although great efforts have been invested in disease control, by contrast, many basic aspects of the biology of P. fusca remain unknown.
Taxonomy: Podosphaera fusca (Fr.) Braun & Shishkoff. Kingdom Fungi; Phylum Ascomycota; Subdivision Pezizomycotina; Class Leotiomycetes; Order Erysiphales; Family Erysiphaceae; genus Podosphaera ; species fusca.
Identification: Superficial persistent mycelium. Conidia in chains, hyaline, ellipsoid to ovoid or doliform, about 24–40 × 15–22 µm, with cylindrical or cone-shaped fibrosin bodies, which often germinate from a lateral face and produce a broad, clavate germ tube and cylindrical foot-cells. Unbranched erect conidiophores. Cleistothecia globose, mostly 70–100 µm in diameter, dark brown/black. One ascus per cleistothecium with eight ascospores.
Host range: Angiosperm species that include several families, such as Asteracea, Cucurbitaceae, Lamiaceae, Scrophulariaceae, Solanaceae and Verbenaceae.
Disease symptoms: White colonies develop on leaf surfaces, petioles and stems. Under favourable environmental conditions, the colonies coalesce and the host tissue becomes chlorotic and usually senesces early.
Control: Chemical control and the use of resistant cultivars. Resistance has been documented in populations of P. fusca to some of the chemicals registered for control. 相似文献
Taxonomy: Podosphaera fusca (Fr.) Braun & Shishkoff. Kingdom Fungi; Phylum Ascomycota; Subdivision Pezizomycotina; Class Leotiomycetes; Order Erysiphales; Family Erysiphaceae; genus Podosphaera ; species fusca.
Identification: Superficial persistent mycelium. Conidia in chains, hyaline, ellipsoid to ovoid or doliform, about 24–40 × 15–22 µm, with cylindrical or cone-shaped fibrosin bodies, which often germinate from a lateral face and produce a broad, clavate germ tube and cylindrical foot-cells. Unbranched erect conidiophores. Cleistothecia globose, mostly 70–100 µm in diameter, dark brown/black. One ascus per cleistothecium with eight ascospores.
Host range: Angiosperm species that include several families, such as Asteracea, Cucurbitaceae, Lamiaceae, Scrophulariaceae, Solanaceae and Verbenaceae.
Disease symptoms: White colonies develop on leaf surfaces, petioles and stems. Under favourable environmental conditions, the colonies coalesce and the host tissue becomes chlorotic and usually senesces early.
Control: Chemical control and the use of resistant cultivars. Resistance has been documented in populations of P. fusca to some of the chemicals registered for control. 相似文献
57.
58.
ANTONIO FLORES-MOYA IVÁN GÓMEZ BENJAMÍN VIÑEGLA MARÍA ALTAMIRANO EDUARDO PÉREZ-RODRÍGUEZ CRISTINA MAESTRE ROSARIO M. CABALLERO & FÉLIX L. FIGUEROA 《The New phytologist》1998,139(4):673-683
The effects of full-spectrum solar radiation and of solar radiation deprived of total u.v. radiation (λ<395 nm) on the endemic Mediterranean red alga Rissoella verruculosa (Bertoloni) J. Agardh were studied in situ in early summer, from sunrise to sunset. Photosynthetic performance, pigment content and the activities of enzymes related to nutrient uptake, were monitored under both radiation conditions throughout a daylight period.
The doses of solar radiation, measured on the day during which the experiments were carried out (24 June 1997), were 9228·25, 1109·70 and 13·03 kJ m−2 for PAR (λ=400–700 nm), u.v.-A (λ=315–400 nm) and u.v.-B (λ=280–315 nm), respectively. Under these conditions, a clear daily variation in photosynthetic performance was found. However, no significant differences were detected between the two radiation conditions. At noon, strong sunlight impaired O2 evolution by 75%, but complete recovery occurred during the afternoon, reaching similar values to those measured in the early morning. By contrast, photoinhibition of optimal quantum yield ( F v / F m ), and the relative electron transport rate was followed by only a slight recovery during the afternoon. The rate of photosynthesis in air (simulating emersion conditions), estimated by CO2 exchange, showed a negative balance at noon, which was accentuated in plants exposed to the full-solar spectrum.
Significant changes in the activities of nitrate reductase and carbonic anhydrase were found throughout the day under both radiation conditions. In thalli receiving solar radiation deprived of u.v., total CA activity decreased throughout the day. However, in thalli exposed to full-spectrum solar radiation, the activity of the enzyme tended to increase in the afternoon, correlating with an increase in NR activity. 相似文献
The doses of solar radiation, measured on the day during which the experiments were carried out (24 June 1997), were 9228·25, 1109·70 and 13·03 kJ m
Significant changes in the activities of nitrate reductase and carbonic anhydrase were found throughout the day under both radiation conditions. In thalli receiving solar radiation deprived of u.v., total CA activity decreased throughout the day. However, in thalli exposed to full-spectrum solar radiation, the activity of the enzyme tended to increase in the afternoon, correlating with an increase in NR activity. 相似文献
59.
Radiotracking was used to study the ranging behaviour and movements of the Nutcracker Nucifraga caryocatactes in the Alevé forest (northwest Italian Alps), from September to December 1994-96, when Nutcrackers collected seeds of Arolla Pines Pinus cembra. Home range size and overlap decreased from September to December. Autumn ranging behaviour was not consistent with territoriality. Nutcrackers stored seeds throughout the Alevé; many apparently stored seeds in scree at high altitudes (above 2200 m) where the forest comes to an end, and also in Larch forests opposite the Alevé (probably to avoid competition with rodents and conspecifics). Estimates of Nutcracker abundance, derived from transect counts, varied significantly among habitats, years and months, which possibly reflected differences in seed availability and abundance. The ranging behaviour observed at the Alevé was compared with that monitored at Mont Avic, another area in the northwest Italian Alps, where resources (in this case Hazel Corylus avellana nuts) were concentrated in a few zones. Home range size was significantly larger at Mont Avic, especially during late autumn. There, the home range size increased and overlap decreased from September to November, when birds abandoned Hazels and dispersed to the coniferous woods. Differences between Alevé and Mont Avic implied that the availability and distribution of resources are the major determinants of the ranging behaviour of the Nutcracker during autumn. However, differences between adults and juveniles were also found. 相似文献
60.
MANUEL B. CRESPO ANTONIO DE LA TORRE JOSE L. SOLANAS 《Botanical journal of the Linnean Society. Linnean Society of London》1994,116(2):135-144
Linaria arabiniana sp. nov. is described from coastal sand dunes of a very reduced area in Alicante Province (south-eastern part of the Iberian Peninsula). It is a perennial herb characterized by its 3–4-verticillate leaves, glabrous stems, large violet or rarely yellow flowers, and bicoloured usually flat seeds. Morphological characteristics and taxonomic affinities of this taxon are discussed, as are data on its ecology, phytosociology, and eventual conservation features. 相似文献