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排序方式: 共有132条查询结果,搜索用时 15 毫秒
1.
2.
DALDINIA CONCENTRICA ATTACKING THE WOOD OF FRAXINUS EXCELSIOR 总被引:1,自引:0,他引:1
3.
Hernandez-Trejo A B Estrada-Drouaillet JA López-Santillán C Rios-Velasco SE Varela-Fuentes R Rodríguez-Herrera E Osorio-Hernández 《Phyton》2019,88(1):47-54
The control of Spodoptera frugiperda is based
on synthetic insecticides, so some alternatives are the use of
entomopathogenic fungi (EF) and neem extract. The objective of
the study was to evaluate in vitro effectiveness of native EF and
neem extracts on S. frugiperda larvae. Six EF were identified by
DNA sequencing of ITS regions from three EF (Fusarium solani,
Metarrhizium robertsii, Nigrospora spherica and Penicillium
citrinum). They were evaluated in concentrations of 1 × 10⁸ spores/
mL. In addition, a second bioassay was carried out evaluating
only F. solani, M. robertsii and N. sphaerica and the addition
of vegetable oil. On the other hand, extraction of secondary
metabolites from neem seed (Azadirachta indica) was carried
out by performing, mass (g) and solvent volume (mL ethanol
and water) combinations, which were subjected to microwaves
and ultrasound. Subsequently, these extracts were evaluated
in concentrations of 3%, 4% and 5%. A survival analysis was
performed for each of the bioassays. With respect to the results
of the first bioassay, F. solani obtained a probability of survival of
0.476 on the seventh day, while in the second bioassay, M. robertsii
obtained 0.488 survival probability. This suggests that the expected
percentage of larvae that stay alive on the sixth day is 48.8%.
However, in the evaluation of the neem extract the combination
1:12/70% to 4% caused 84% mortality of larvae. The use of native
HE and neem extracts has potential for the control of S. frugiperda. 相似文献
4.
Differential expression of globin genes has provided an interesting model system for better understanding commonly inherited diseases such as thalassemia. In the avian beta-type globin cluster (5'-rho-betaH-betaA-epsilon-3'), silencing of the embryonic rho-globin gene occurs concomitantly with the activation of the adult betaA-globin gene during embryonic development. DNA methylation is a dynamic process that regulates gene expression. We observed a progressive loss of methylation of betaA-globin gene, during avian embryonic development that was concurrent with the expression of the gene. The promoter and exon 1 regions of the template strand were completely demethylated, whereas residual methylation was retained in exons 2 and 3. Using a modified methylation-sensitive single-nucleotide primer extension (MS-SNuPE) assay, we observed stage-specific demethylase activity in the nuclear extracts of chicken red cells; activity in 5-, 8-, and 11-day-old erythroid cell nuclear extracts was 6, 76, and 24%, respectively. The demethylase targeted both hemimethylated and fully methylated substrates. Our findings demonstrate stage-specific demethylase activity in nuclear extracts from primary chicken erythroid cells that could target the fully methylated promoter of a developmentally regulated native gene. 相似文献
5.
6.
Wan H Luo F Wert SE Zhang L Xu Y Ikegami M Maeda Y Bell SM Whitsett JA 《Development (Cambridge, England)》2008,135(15):2563-2572
7.
de Jong A Dondorp WJ Frints SG de Die-Smulders CE de Wert GM 《Nature reviews. Genetics》2011,12(9):657-663
Prenatal screening strategies are undergoing rapid changes owing to the introduction of new testing techniques. The overall tendency is towards broadening the scope of prenatal testing through increasingly sensitive ultrasound scans and genome-wide molecular tests. In addition, non-invasive prenatal diagnosis is likely to be introduced in the near future. These developments raise important ethical questions concerning meaningful reproductive choice, the autonomy rights of future children, equity of access and the proportionality of testing. 相似文献
8.
Fibroblast growth factor 18 influences proximal programming during lung morphogenesis 总被引:1,自引:0,他引:1
Whitsett JA Clark JC Picard L Tichelaar JW Wert SE Itoh N Perl AK Stahlman MT 《The Journal of biological chemistry》2002,277(25):22743-22749
The structure and functions of the airways of the lung change dramatically along their lengths. Large-diameter conducting airways are supported by cartilaginous rings and smooth muscle tissue and are lined by ciliated and secretory epithelial cells that are involved in mucociliary clearance. Smaller peripheral airways formed during branching morphogenesis are lined by cuboidal and squamous cells that facilitate gas exchange to a network of fine capillaries. The factors that mediate formation of these changing cell types and structures along the length of the airways are unknown. We report here that conditional expression of fibroblast growth factor (FGF)-18 in epithelial cells of the developing lung caused the airway to adopt structural features of proximal airways. Peripheral lung tubules were markedly diminished in numbers, whereas the size and extent of conducting airways were increased. Abnormal smooth muscle and cartilage were found in the walls of expanded distal airways, which were accompanied by atypically large pulmonary blood vessels. Expression of proteins normally expressed in peripheral lung tubules, including SP-B and pro-SP-C, was inhibited. FGF-18 mRNA was detected in normal mouse lung in stromal cells surrounding proximal airway cartilage and in peripheral lung mesenchyme. Effects were unique to FGF-18 because expression of other members of the FGF family had different consequences. These data show that FGF-18 is capable of enhancing proximal and inhibiting peripheral programs during lung morphogenesis. 相似文献
9.
10.
Ikegami M Hull WM Yoshida M Wert SE Whitsett JA 《American journal of physiology. Lung cellular and molecular physiology》2001,281(3):L697-L703
Both surfactant protein (SP) D and granulocyte-macrophage colony-stimulating factor (GM-CSF) influence pulmonary surfactant homeostasis, with the deficiency of either protein causing marked accumulation of surfactant phospholipids in lung tissues and in the alveoli. To assess whether the effects of each gene were mediated by distinct or shared mechanisms, surfactant homeostasis and lung morphology were assessed in 1) double-transgenic mice in which both SP-D and GM-CSF genes were ablated [SP-D(-/-),GM(-/-)] and 2) transgenic mice deficient in both SP-D and GM-CSF in which the expression of GM-CSF was increased in the lung. Saturated phosphatidylcholine (Sat PC) pool sizes were markedly increased in SP-D(-/-),GM(-/-) mice, with the effects of each gene deletion on surfactant Sat PC pool sizes being approximately additive. Expression of GM-CSF in lungs of SP-D(-/-),GM(-/-) mice corrected GM-CSF-dependent abnormalities in surfactant catabolism but did not correct lung pathology characteristic of SP-D deletion. In contrast to findings in GM(-/-) mice, degradation of [(3)H]dipalmitoylphosphatidylcholine by alveolar macrophages from the SP-D(-/-) mice was normal. The emphysema and foamy macrophage infiltrates characteristic of SP-D(-/-) mice were similar in the presence or absence of GM-CSF. Taken together, these findings demonstrate the distinct roles of SP-D and GM-CSF in the regulation of surfactant homeostasis and lung structure. 相似文献