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61.
We investigated if Pinus ponderosa plantations in Patagonia are able to produce viable mycorrhizal inocula towards adjacent grasslands, which only harbor endomycorrhizal vegetation. We hypothesized that these inocula have the potential to contribute to the establishment of naturally disseminated seedlings. Also, we determined the main fungal taxa involved in this process. Seven plantations in the onset of their reproductive phase and located in the Patagonian native forest/steppe ecotone (Argentina) were selected. Soil samplings were obtained at nine points along a 450 m long, W-E transect established in each plantation. Soil bioassays were performed in a greenhouse, with P. ponderosa seedlings acting as hosts for mycorrhizal inocula present in soil samples, during 12 months. Mycorrhization percentage, morphotype richness and morphotype composition was determined through morphological evaluation. Viable ecto- and ectendomycorrhizal inocula were found disseminated outside plantations. The amount of mycorrhizal inoculum followed a decreasing function with distance to plantation edges. Mycorrhizal fungal genus Rhizopogon and “E-strain” mycorrhizal types appeared as pioneering taxa regarding seedlings colonization, being the most persistent and frequent symbionts found. Plantations, thus, facilitate the surrounding terrain for newcoming seedlings through the dispersion of mycorrhizal fungal inocula.  相似文献   
62.
A lupin seed γ-conglutin-enriched preparation was tested in a glucose overload trial with both murine models and adult healthy volunteers. The results with rats showed a dose-dependent significant decrease of blood glucose concentration, which confirmed previous findings obtained with the purified protein. Moreover, three test-product doses equivalent to 630, 315, and 157.5 mg γ-conglutin, orally administered 30 min before the carbohydrate supply, showed a relevant hypoglycemic effect in human trials. Insulin concentrations were not significantly affected. The general hematic parameters did not change at all.This is the first report on the glucose-lowering effect of lupin γ-conglutin in human subjects.  相似文献   
63.
Consumption of fruits and vegetables, which are rich in polyphenols, has been associated with a reduced risk of chronic diseases such as cancer. Dietary polyphenols have antioxidant and antiproliferative properties that might explain their beneficial effect on cancer prevention. The aim of this study was to investigate the effects of different pure polyphenols [quercetin, chlorogenic acid, and (-)-epicatechin] and natural fruit extracts (strawberry and plum) on viability or apoptosis of human hepatoma HepG2 cells. The treatment of cells for 18 h with quercetin and fruit extracts reduced cell viability in a dose-dependent manner; however, chlorogenic acid and (-)-epicatechin had no prominent effects on the cell death rate. Similarly, quercetin and strawberry and plum extracts, rather than chlorogenic acid and (-)-epicatechin, induced apoptosis in HepG2 cells. Moreover, quercetin and fruit extracts arrested the G1 phase in the cell cycle progression prior to apoptosis. Quercetin and strawberry and plum extracts may induce apoptosis and contribute to a reduced cell viability in HepG2 cells.  相似文献   
64.
Pistachio (Pistacia vera L.) is a strategic nut tree species in the Middle East which holds comparative advantage over other fruit trees in view of its hardiness, income generation opportunities and benefits for the ecosystem. Yet pistachio cultivation depends on a very narrow genetic base, in spite of the existence of many varieties still marginally exploited. Syria is an important center of diversity for pistachio. A country wide ecogeographic survey in this country was carried out to determine the extent of pistachio genetic diversity and its use. As a whole, 114 accessions were collected from 37 farms to assess diversity at morphological and molecular level. Molecular evaluation was carried out using Amplified Fragment Length Polymorphism (AFLP) technique and performed using seven primer pair combinations. Results from the studies allowed the identification of 25 pistachio female varieties in Syria, some of which unique and described for the first time. Three groups of pistachio diversity were identified by cluster analysis which provides useful information about the distribution of genetic diversity in Syria for enhanced use and sustainable conservation.  相似文献   
65.
Mice in which all members of the Hox10 or Hox11 paralogous group are disrupted provide evidence that these Hox genes are involved in global patterning of the axial and appendicular skeleton. In the absence of Hox10 function, no lumbar vertebrae are formed. Instead, ribs project from all posterior vertebrae, extending caudally from the last thoracic vertebrae to beyond the sacral region. In the absence of Hox11 function, sacral vertebrae are not formed and instead these vertebrae assume a lumbar identity. The redundancy among these paralogous family members is so great that this global aspect of Hox patterning is not apparent in mice that are mutant for five of the six paralogous alleles.  相似文献   
66.
67.
Plasmon rulers can be used to determine nanoscale distances within chemical or biological species. They are based on the spectral shift of the scattering spectrum when two plasmonic nanoparticles approach one another. However, the one-dimensionality of current plasmon rulers hampers the comprehensive understanding of many intriguing processes in soft matter, which take place in three dimensions. We demonstrated a three-dimensional plasmon ruler that is based on coupled plasmonic oligomers in combination with high-resolution plasmon spectroscopy. This enables retrieval of the complete spatial configuration of complex macromolecular and biological processes as well as their dynamic evolution.  相似文献   
68.
Multidrug-resistant tuberculosis (MDR) is perceived as a growing hazard to human health worldwide. Judgments about the true scale of the problem, and strategies for containing it, need to come from a balanced appraisal of the epidemiological evidence. We conclude in this review that MDR is, and will probably remain, a locally severe problem; that epidemics can be prevented by fully exploiting the potential of standard short-course chemotherapy (SCC) based on cheap and safe first-line drugs; and that best-practice SCC may even reduce the incidence of MDR where it has already become endemic. On the basis of the available, imperfect data, we recommend a three-part response to the threat of MDR: widespread implementation of SCC as the cornerstone of good tuberculosis control, improved resistance testing and surveillance, and the careful introduction of second-line drugs after a sound evaluation of cost, effectiveness, and feasibility.  相似文献   
69.
Abundant extraterrestrial chromite grains from decomposed meteorites occur in middle Ordovician (480 million years ago) marine limestone over an area of approximately 250,000 square kilometers in southern Sweden. The chromite anomaly gives support for an increase of two orders of magnitude in the influx of meteorites to Earth during the mid-Ordovician, as previously indicated by fossil meteorites. Extraterrestrial chromite grains in mid-Ordovician limestone can be used to constrain in detail the temporal variations in flux of extraterrestrial matter after one of the largest asteroid disruption events in the asteroid belt in late solar-system history.  相似文献   
70.
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