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101.
Mustafa Emre Salih Cetiner Sevil Zencir Isa Unlukurt Ibrahim Kahraman Zeki Topcu 《Cell biochemistry and biophysics》2011,59(2):71-77
We investigated the effect of extremely low-frequency electromagnetic field (ELF-EMF) with pulse trains exposure on lipid
peroxidation, and, hence, oxidative stress in the rat liver tissue. The parameters that we measured were the levels of plasma
alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase as well as plasma albumin, bilirubin, and total
protein levels in 30 adult male Wistar rats exposed to ELF. We also determined the percentage of apoptotic and necrotic cells
of the kidney extracts from the animals by flow cytometry method. Apoptotic cell death was further characterized by monitoring
DNA degradation using gel electrophoresis. The results showed an increase in the levels of oxidative stress indicators, and
the flow cytometric data suggested a possible relationship between the exposure to magnetic field and the cell death. We showed
significantly lower necrotic cell percentages in experimental animals compared to either unexposed or sham control groups.
However, DNA ladder analyses did not differentiate between the groups. Our results were discussed in relation to the response
of biological systems to EMF. 相似文献
102.
103.
de Semir D Maurisse R Du F Xu J Yang X Illek B Gruenert DC 《Cell and tissue research》2012,347(2):357-367
The prospect of developing large animal models for the study of inherited diseases, such as cystic fibrosis (CF), through
somatic cell nuclear transfer (SCNT) has opened up new opportunities for enhancing our understanding of disease pathology
and for identifying new therapies. Thus, the development of species-specific in vitro cell systems that will provide broader
insight into organ- and cell-type-specific functions relevant to the pathology of the disease is crucial. Studies have been
undertaken to establish transformed rabbit airway epithelial cell lines that display differentiated features characteristic
of the primary airway epithelium. This study describes the successful establishment and characterization of two SV40-transformed
rabbit tracheal epithelial cell lines. These cell lines, 5RTEo- and 9RTEo-, express the CF transmembrane conductance regulator
(CFTR) gene, retain epithelial-specific differentiated morphology and show CFTR-based cAMP-dependent Cl− ion transport across the apical membrane of a confluent monolayer. Immunocytochemical analysis indicates the presence of
airway cytokeratins and tight-junction proteins in the 9RTEo- cell line after multiple generations. However, the tight junctions
appear to diminish in their efficacy in both cell lines after at least 100 generations. Initial SCNT studies with the 9RTEo-
cells have revealed that SV40-transformed rabbit airway epithelial donor cells can be used to generate blastocysts. These
cell systems provide valuable models for studying the developmental and metabolic modulation of CFTR gene expression and rabbit airway epithelial cell biology. 相似文献
104.
Valéria Forni Martins Paulo Roberto GuimarãesJr. Claudia Regina Baptista Haddad João Semir 《Plant Ecology》2009,205(2):213-222
The directed dispersal hypothesis has two components: (1) non-random seed deposition by a predicted vector, which removes
greater amounts of seeds to specific sites, and (2) higher seed survival and seedling establishment in these specific sites.
Several studies suggest that ants perform both tasks. This study was designed to cover the processes from post-dispersed seeds
to established juvenile plants of a typical ant-dispersed species. Our main objective was to determine whether Ricinus
communis benefits from directed dispersal by ants to maintain its populations in previously colonized habitats. We examined whether
there were differences between ant nest pile mounds and their vicinities in the: (1) densities of seeds with and without elaiosome,
seedlings and juveniles; (2) performance of post-dispersed seeds (without elaiosome), which may be affected by seed density,
a key feature attracting seed predators; (3) nutrient quantities; (4) number of germinated seeds and juvenile biomass measurements;
and (5) ant protection of seedlings from herbivores. There were more seeds without elaiosome, seedlings and juveniles in pile
mounds, and seeds with elaiosome were equally distributed. There was no difference in the number of non-removed seeds in pile
mounds and in their vicinities, and there was no tendency for this difference to increase or decrease with time or with initial
seed density. Apparently, there was no difference in nutrient contents in soils of pile mounds and their vicinities. Likewise,
there was no difference in the number of seeds germinated and in the biomass measurements of juveniles in both soils. Ants
did not provide differential protection for seedlings in pile mounds against potential herbivores. The dispersal of Ricinus seeds by ants had a marked effect on the distribution pattern of the seeds, seedlings and juveniles of this species. However,
there were no additional advantages for the seeds, seedlings and juveniles in pile mounds and, therefore, Ricinus does not benefit from directed dispersal by ants to maintain its populations in the study sites. 相似文献
105.
Two different volatile isolates from the aerial parts of Cardaria draba (L.) Desv., obtained either by hydrodistillation (Extract I) or by CH2Cl2 extraction subsequent to hydrolysis by exogenous myrosinase (Extract II), were characterized by GC‐FID and GC/MS analyses. The main volatiles obtained by hydrodistillation, i.e., 4‐(methylsulfanyl)butyl isothiocyanate ( 1 ; 28.0%) and 5‐(methylsulfanyl)pentanenitrile ( 2 ; 13.8%), originated from the degradation of glucoerucin. In Extract I, also volatiles without sulfur and/or nitrogen were identified. These were mostly hexadecanoic acid (10.8%), phytol (10.2%), dibutyl phthalate (4.5%), and some other compounds in smaller percentages. Extract II contained mostly glucosinolate degradation products. They originated from glucoraphanin, viz., 4‐(methylsulfinyl)butyl isothiocyanate ( 3 ; 69.2%) and 5‐(methylsulfinyl)pentanenitrile ( 4 ; 4.5%), glucosinalbin, viz., 2‐(4‐hydroxyphenyl)acetonitrile ( 5 ; 7.2%), and glucoerysolin, viz., 4‐(methylsulfonyl)butyl isothiocyanate ( 6 ; 5.0%). Moreover, the volatile samples were evaluated for their antimicrobial activity using the disc‐diffusion method and determining minimum inhibitory concentrations (MIC). All volatile isolates expressed a wide range of growth inhibition activity against both Gram‐positive and Gram‐negative bacteria and fungi. The MIC values varied between 4 and 128 μg/ml. 相似文献
106.
Blažević I Radonić A Skočibušić M De Nicola GR Montaut S Iori R Rollin P Mastelić J Zekić M Maravić A 《化学与生物多样性》2011,8(12):2310-2321
Glucosinolates (GLs) were characterized in various aerial parts (stems, leaves, and flowers) of Aurinia leucadea (Guss.) C. Koch and quantified according to the ISO 9167-1 official method based on the HPLC analysis of desulfoglucosinolates. Eight GLs, i.e., glucoraphanin (GRA), glucoalyssin (GAL; 1), gluconapin (GNA; 2), glucocochlearin (GCC), glucobrassicanapin (GBN; 3), glucotropaeolin (GTL), glucoerucin (GER), and glucoberteroin (GBE) were identified. The total GL contents were 57.1, 37.8, and 81.3 μmol/g dry weight in the stems, leaves, and flowers, respectively. The major GL detected in all parts of the plant was 2, followed by 1 and 3. GC/MS Analysis of the volatile fractions extracted from the aerial parts of fresh plant material either by hydrodistillation or CH(2) Cl(2) extraction showed that these fractions mostly contained isothiocyanates (ITCs). The main ITCs were but-3-enyl- (55.6-71.8%), pent-4-enyl- (7.6-15.3%), and 5-(methylsulfinyl)pentyl ITC (0-9.5%), originating from the corresponding GLs 2, 3, and 1, respectively. The antimicrobial activity of the volatile samples was investigated by determining inhibition zones with the disk-diffusion method and minimal inhibitory concentrations (MIC) with the microdilution method. They were found to inhibit a wide range of bacteria and fungi, with MIC values of 2.0-32.0 μg/ml, indicating their promising antimicrobial potential, especially against the fungi Candida albicans and Rhizopus stolonifer as well as against the clinically important pathogen Pseudomonas aeruginosa. 相似文献
107.
Ozsarlak-Sozer G Kerry Z Gokce G Oran I Topcu Z 《Journal of physiology and biochemistry》2011,67(1):35-42
Telomeres are specialized DNA–protein complexes found at the tips of linear chromosomes. In this study, we investigated the
effects of oxidative stress on telomeric length distribution of proliferating vascular smooth muscle cells following balloon
injury in single or combined treatment of rabbits with either buthionine sulfoximine or taurine. Exposure to oxidative stress
increased the balloon injury whereas taurine treatment significantly diminished l-buthionine-sulfoximine-related intimal hyperplasia. Our results also showed that both variables had a significant influence
on mean telomeric length distribution. 相似文献
108.
Yeast mutants lacking telomerase are able to elongate their telomeres through processes involving homologous recombination. In this study, we investigated telomeric recombination in several mutants that normally maintain very short telomeres due to the presence of a partially functional telomerase. The abnormal colony morphology present in some mutants was correlated with especially short average telomere length and with a requirement for RAD52 for indefinite growth. Better-growing derivatives of some of the mutants were occasionally observed and were found to have substantially elongated telomeres. These telomeres were composed of alternating patterns of mutationally tagged telomeric repeats and wild-type repeats, an outcome consistent with amplification occurring via recombination rather than telomerase. Our results suggest that recombination at telomeres can produce two distinct outcomes in the mutants we studied. In occasional cells, recombination generates substantially longer telomeres, apparently through the roll-and-spread mechanism. However, in most cells, recombination appears limited to helping to maintain very short telomeres. The latter outcome likely represents a simplified form of recombinational telomere maintenance that is independent of the generation and copying of telomeric circles. 相似文献
109.
Local genetic differentiation in Proteopsis argentea (Asteraceae), a perennial herb endemic in Brazil 总被引:1,自引:1,他引:0
F. F. Jesus V. N. Solferini J. Semir P. I. Prado 《Plant Systematics and Evolution》2001,226(1-2):59-68
Proteopsis argentea (Asteraceae, Vernonieae) is a perennial herb endemic to the “campos rupestres” of the Espinha?o Range in Minas Gerais, Brazil,
with fragmented populational distribution. Eleven populations were sampled, throughout the entire distribution of the species,
and assayed for isozyme variation. Low intra-population genetic diversity was found (P = 19.2; A = 1.30; He = 0.058) whereas
species level diversity was higher (P = 55.5, A = 2.0, He = 0.093). The most geographically isolated population showed exclusive
alleles at two loci, whereas two populations less than 2 km apart from each other showed inverted frequencies for two alleles.
Mean genetic identity was high (I = 0.974), but the large Fst (0.30) indicates that the species could lose an important part
of its genetic variation with the extinction of a single population. Our findings indicate that geographic isolation alone
cannot explain population differentiation: localized pollinator behaviour and selection, for example, may be contributing
to the patterns observed.
Received February 18, 2000 Accepted November 1, 2000 相似文献
110.
Kruithof BP van Wijk B Somi S Kruithof-de Julio M Pérez Pomares JM Weesie F Wessels A Moorman AF van den Hoff MJ 《Developmental biology》2006,295(2):507-522
Proepicardial cells give rise to epicardium, coronary vasculature and cardiac fibroblasts. The proepicardium is derived from the mesodermal lining of the prospective pericardial cavity that simultaneously contributes myocardium to the venous pole of the elongating primitive heart tube. Using proepicardial explant cultures, we show that proepicardial cells have the potential to differentiate into cardiac muscle cells, reflecting the multipotency of this pericardial mesoderm. The differentiation into the myocardial or epicardial lineage is mediated by the cooperative action of BMP and FGF signaling. BMP2 is expressed in the distal IFT myocardium and stimulates cardiomyocyte formation. FGF2 is expressed in the proepicardium and stimulates differentiation into the epicardial lineage. In the base of the proepicardium, coexpression of BMP2 and FGF2 inhibits both myocardial and epicardial differentiation. We conclude that the epicardial/myocardial lineage decisions are mediated by an extrinsic, inductive mechanism, which is determined by the position of the cells in the pericardial mesoderm. 相似文献