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91.
92.
By using genome in situ hybridization (GISH) on root somatic chromosomes of allotetraploid derived from the cross Gossypium arboreum × G. bickii with genomic DNA (gDNA) of G. bickii as a probe, two sets of chromosomes, consisting of 26 chromosomes each, were easily distinguished from each other by their distinctive hybridization signals. GISH analysis directly proved that the hybrid GarboreumxG. bickii is an allotetraploid amphiploid. The karyotype formula of the species was 2n = 4x = 52 = 46m (4sat) + 6sm (4sat). We identified four pairs of satellites with two pairs in each sub-genome. FISH analysis using 45S rDNA as a probe showed that the cross G. arboreumxG. bickii contained 14 NORs. At least five pairs of chromosomes in the G sub-genome showed double hybridization (red and blue) in their long arms, which indicates that chromatin introgression from the A sub-genome had occurred. 相似文献
93.
Heng HH Bremer SW Stevens J Ye KJ Miller F Liu G Ye CJ 《Journal of cellular biochemistry》2006,98(6):1424-1435
The establishment of the correct conceptual framework is vital to any scientific discipline including cancer research. Influenced by hematologic cancer studies, the current cancer concept focuses on the stepwise patterns of progression as defined by specific recurrent genetic aberrations. This concept has faced a tough challenge as the majority of cancer cases follow non-linear patterns and display stochastic progression. In light of the recent discovery that genomic instability is directly linked to stochastic non-clonal chromosome aberrations (NCCAs), and that cancer progression can be characterized as a dynamic relationship between NCCAs and recurrent clonal chromosome aberrations (CCAs), we propose that the dynamics of NCCAs is a key element for karyotypic evolution in solid tumors. To support this viewpoint, we briefly discuss various basic elements responsible for cancer initiation and progression within an evolutionary context. We argue that even though stochastic changes can be detected at various levels of genetic organization, such as at the gene level and epigenetic level, it is primarily detected at the chromosomal or genome level. Thus, NCCA-mediated genomic variation plays a dominant role in cancer progression. To further illustrate the involvement of NCCA/CCA cycles in the pattern of cancer evolution, four cancer evolutionary models have been proposed based on the comparative analysis of karyotype patterns of various types of cancer. 相似文献
94.
Seyed Mahmood Ghaffari 《Biologia》2006,61(4):375-379
Karyotype analysis and chromosome behaviour in tetraploid Allium iranicum is reported. The somatic karyotype 2n = 32, consists of 12 pairs of metacentric chromosomes, two pairs of submetacentric chromosomes and two pairs of submetacentric
satellite chromosomes. Chromosome complement follows two sets of 16 pairs of homologous chromosomes. A detailed analysis of
Pachytene, Diplotene and Metaphase I of meiosis in pollen mother cells in this taxon showed that the most common chromosome
configurations were bivalents at all subphases mentioned. It is concluded that A. iranicum is most likely a natural allotetraploid and certainly differs from related species A. ampeloprasum, A. commutatum and A. porrum. 相似文献
95.
Nineteen Trypanosoma cruzi stocks, most of them of wild origin, and four Trypanosoma rangeli stocks from Colombia were analysed by molecular karyotype analysis with cloned DNA cruzipain as the probe. Another 27 cloned stocks of T. cruzi from different geographic areas of South America were used as reference for T. cruzi lineages. Phenetic analysis of chromosome size polymorphism demonstrated a great variability of Colombian T. cruzi stocks, suggesting that most belong to lineage I, although two of them belong to lineage II. The 2 lineage II T. cruzi, 17 T. cruzi lineage I, and 3 T. rangeli stocks from Colombia were studied further by Southern blot analysis with a panel of kinetoplast DNA minicircle probes. Hybridisation results indicate that the two T. cruzi II stocks are genetically distant from each other and from T. cruzi lineages IIb, IId, and IIe from Chile. Finally, T. cruzi minicircle probes do not cross-hybridise in any stringency condition tested with T. rangeli minicircles, a clear indication that these parasites can be easily distinguished by this method. 相似文献
96.
Karyotype, location of the nucleolar organiser region (NOR) and heterochromatin presence and composition were studied in the
Antarctic scallop Adamussium colbecki Smith, 1902. The karyotype exhibits 2n = 38 chromosomes with 11 pairs of metacentrics, 5 of submetacentrics, one subtelocentric and two telocentrics. Ag–NOR, CMA3, DA/MM and NOR–FISH evidenced paracentromeric NORs on the short arm of 2nd pair chromosomes. Digestion with three restriction
endonucleases followed by sequential staining with Giemsa, CMA3 and DAPI evidenced on all chromosomes centromeric heterochromatin positive for both DAPI and CMA3. In situ hybridisation analysis showed the presence of an AT-rich satellite DNA in the centromeric heterochromatin of several chromosomes.
A mosaicism was detected in the germinal cell lines of one specimen, as in six of the 20 plates examined the set had 37 chromosomes
with a missing pair of telocentrics and an unpaired metacentric. Comparison of the chromosome sets of all the pectinids studied
to date and comparison with a phyletic tree obtained from molecular mitochondrial genes studies yielded good agreement between
karyotype morphology and taxonomic classification. 相似文献
97.
The speciose Brazilian Elateridae fauna is characterized by high karyotypic diversity, including one species (Chalcolepidius zonatus Eschscholtz, 1829) with the lowest diploid number within any Coleoptera order. Cytogenetic analysis of Conoderus dimidiatus Germar, 1839, C. scalaris (Germar, 1824,) C. ternarius Germar, 1839, and C. stigmosus Germar, 1839 by standard and differential staining was performed with the aim of establishing mechanisms of karyotypic differentiation
in these species. Conoderus dimidiatus, C. scalaris, and C. ternarius have diploid numbers of 2n(♂) = 17 and 2n(♀) = 18, and a X0/XX sex determination system, similar to that encountered in the majority of Conoderini species. The karyotype
of C. stigmosus was characterized by a diploid number of 2n=16 and a neoXY/neoXX sex determination system that was highly differentiated from other species of the genus. Some features
of the mitotic and meiotic chromosomes suggest an autosome/ancestral X chromosome fusion as the cause of the neoXY system
origin in C. stigmosus. C-banding and silver impregnation techniques showed that the four Conoderus species possess similar chromosomal characteristics
to those registered in most Polyphaga species, including pericentromeric C band and autosomal NORs. Triple staining techniques
including CMA3/DA/DAPI also provided useful information for differentiating these Conoderus species. These techniques revealed unique GC-rich heterochromatin associated with NORs in C. scalaris and C. stigmosus and CMA3-heteromorphism in C. scalaris and C. ternarius. 相似文献
98.
In this paper, we report a chromosomal study of three Brazilian species of Colostethus, C. brunneus from the type locality, Colostethus sp. (aff. trilineatus), and Colostethus sp., which is morphologically similar to C. brunneus. The diploid number for C. brunneus was 2n = 24 chromosomes, in agreement with that previously described for specimens from Peru. Colostethus sp. (aff. trilineatus) and Colostethus sp. showed a very similar karyotype with 22 chromosomes. The NOR was located on pair 3 in C. brunneus, on pair 4 in Colostethus sp. (aff. trilineatus), and on pair 2 in Colostethus sp. In one specimen of Colostethus sp., an additional NOR site was located on pair 7 in only one of the homologs. This extra Ag-NOR site was confirmed by FISH
using an rDNA probe. In addition to the NOR location, the C-banding pattern was also species-specific, despite the similar
chromosomal morphology of the species. These results indicate that although these species may be closely related, there is
a clear dichotomy in their chromosome number. 相似文献
99.
A new cell line from larval fat bodies of the bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae) 总被引:1,自引:0,他引:1
Zhang H Zhang YA Qin Q Wang Y Li X Miao L Yin Z Zhang A Qu L Ding C 《In vitro cellular & developmental biology. Animal》2006,42(10):290-293
Summary A new cell line, designated IOZCAS-Ha-I, was initiated from the fat body of larvae of Helicoverpa armigera (Lepidoptera: Noctuidae) in TNM-FH medium containing 10% fetal bovine serum. Spherical cells were predominant among the various
cell types. The cell line showed a typical lepidopteran chromosome pattern ranging from 58 to 239 chromosomes in the majority
of the cells, it was confirmed to have originated from the H. armigera by the DNA amplification-fingerprinting polymerase chain reaction (DAF-PCR) technique. The new cell line was only slightly
susceptible to the multiple nucleocapsid nuclear polyhedrosis viruses (NPV) from H. armigera. 相似文献
100.