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31.
Lectin histochemistry in rat thyroid tumours 总被引:1,自引:0,他引:1
Y Imamura H Sugihara T Miyake T Ikeda S Noriki N Miyoshi K Nakanishi M Fukuda 《Basic and applied histochemistry》1989,33(3):185-196
The thyroid tumours and background goiterous and adenomatous lesions induced in rats with diisopropanolnitrosamine (DIPN) plus methylthiouracil (MTU), and regenerative thyroid tissues after wounding were studied by lectin histochemistry. Ten weeks after cessation of the carcinogen treatments, carcinomas invading the surrounding tissues and blood vessels (13/20) and papillary micronodules (11/20) were formed in the thyroid tissues. In general, the carcinoma lesion was solitary, and the papillary micronodules were multiple in a single thyroid gland. Among the lectins tested, Maclura pomifera (MPA) and Solanum tuberosum (STA) showed specific binding with both carcinoma and papillary micronodule lesions, but not with the background goiterous and adenomatous lesions and regenerative thyroid tissues. The former both lesions showed higher labelling indices with BUdR or 3H-thymidine and poorer thyroglobulin accumulation than the latters, thereby indicating their enhanced proliferative capability and depressed potency of cyto-differentiation. The common cytological and histochemical properties of carcinoma lesions and papillary micronodules allow us to regard the latter as pre-invading carcinoma lesions. The lectins MPA and STA may be, therefore, used as the specific markers of malignancy in rat thyroid carcinogenesis. 相似文献
32.
Effect of rice fiber on human fecal microflora 总被引:1,自引:0,他引:1
Y Benno K Endo H Miyoshi T Okuda H Koishi T Mitsuoka 《Microbiology and immunology》1989,33(5):435-440
The effects of brown rice, containing fourfold as much dietary fiber as polished rice, on the human fecal microflora were determined. Significantly increased numbers of Bifidobacterium adolescentis and Enterococcus faecalis were observed during the brown rice intake, whereas the total counts and the numbers of bacteroides, Eubacterium aerofaciens, and Escherichia coli during the intake were lower than those before and after the intake. Lower numbers of clostridia and low incidences of Clostridium paraputrificum and C. perfringens were observed during the brown rice intake. 相似文献
33.
34.
Differential tumorigenicity between Epstein-Barr virus genome-positive and genome-negative cell lines with t(11;14)(q13;q32) derived from mantle cell lymphoma. 总被引:1,自引:0,他引:1
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Epstein-Barr virus (EBV) genome has been detected in several human lymphoproliferative diseases, but the oncogenic function of EBV is not fully understood. We previously established EBV-positive (SP-50B) and EBV-negative (SP-53) cell lines with the t(11;14)(q13;q32) chromosome abnormality from a single patient with mantle cell lymphoma. Monoclonal EBV DNA in a circular episomal form was demonstrated in the SP-50B cells by Southern blot hybridization with the EBV-terminal fragment probe. SP-50B cells were positive for not only EBV-encoded nuclear antigen-1 (EBNA1) but also latent membrane protein-1 and EBNA2. None of the EBV-encoded proteins was expressed in SP-53 cells. The isogenic EBV-infected and EBV-free cell lines of neoplastic clones made it possible to examine a tumorigenic role of EBV. Only EBV-positive SP-50B cells possessed malignant phenotypes, such as growth ability in low serum, colony formation in soft agarose, and tumorigenicity in nude mice. On the other hand, a lymphoblastoid B-cell line established by infecting the patient's normal B lymphocytes in vitro with exogenous EBV had no tumorigenicity. These results suggested that EBV infection, if it occurred in neoplastic lymphoma cells, could play a role in acquisition of malignant phenotypes. 相似文献
35.
Minamisawa Kiwamu; Ogawa Ken-Ichiro; Fukuhara Hideyuki; Koga Jinichiro 《Plant & cell physiology》1996,37(4):449-453
Indole-3-acetaldehyde (IAAId) was detected in the culture supernatantof Bradyrhizobium elkanii. Deuteriumlabelled L-tryptophan (Trp)was incorporated into IAAId and indole-3-acetic acid (IAA),suggesting that B. elkanii produces IAA via IAAId from Trp.In B. elkanii cell suspension, indole-3-pyruvic acid (IPyA)was converted to IAAId, and exogenously added IAAId was rapidlyconverted to IAA. Furthermore, the activity of indolepyruvatedecarboxylase (IPDC), which catalyzes the decarboxylation ofIPyA to produce IAAId and is a key enzyme for IPyA pathway,was detected in B. elkanii cell-free extract. The IPDC activitydepended on Mg2+ and thiamine pyrophosphate, cofactors of decarboxylation.This mounting evidence strongly suggests that IAA synthesisoccurs via IPyA pathway (Trp IPyA p IAAId IAA) in B. elkanii. (Received December 11, 1995; Accepted March 4, 1996) 相似文献
36.
Mutations associated with floral organ number in rice 总被引:14,自引:0,他引:14
Nobuhiro Nagasawa Masahiro Miyoshi Hidemi Kitano Hikaru Satoh Yasuo Nagato 《Planta》1996,198(4):627-633
How floral organ number is specified is an interesting subject and has been intensively studied in Arabidopsis thaliana. In rice (Oryza sativa L.), mutations associated with floral organ number have been identified. In three mutants of rice, floral organ number 1 (fon1) and the two alleles, floral organ number 2-1 (fon2-1) and floral organ number 2-2 (fon2-2), the floral organs were increased in number centripetally. Lodicules, homologous to petals, were rarely affected, and stamens were frequently increased from six to seven or eight. Of all the floral organs the number of pistils was the most frequently increased. Among the mutants, fon1 showed a different spectrum of organ number from fon2 -1 and fon2 -2. Lodicules were the most frequently affected in fon1, but pistils of more than half of fon1 flowers were unaffected; in contrast, the pistils of most flowers were increased in fon2 -1 and fon2-2. Homeotic conversion of organ identity was also detected at a low frequency in ectopically formed lodicules and stamens. Lodicules and stamens were partially converted into anthers and stigmas, respectively. Concomitant with the increased number of floral organs, each mutant had an enlarged apical meristem. Although meristem size was comparable among the three mutants and wild type in the early phase of flower development, a significant difference became apparent after the lemma primordium had differentiated. In these mutants, the size of the shoot apical meristem in the embryo and in the vegetative phase was not affected, and no phenotypic abnormalities were detected. These results do not coincide with those for Arabidopsis in which clavatal affects the sizes of both shoot and floral meristems, leading to abnormal phyllotaxis, inflorescence fasciation and increased floral organs. Accordingly, it is considered that FON1 and FON2 function exclusively in the regulation of the floral meristem, not of the vegetative meristem.Abbreviation DIC
differential interference contrast
This work was supported in part by Grant-in-Aid for Scientific Research on Priority Areas from the Ministry of Education, Science and Culture of Japan. 相似文献
37.
In rodents an intravenous administration of viableCryptococcus (C.) neoformans cells frequently resulted in attachment of intravascular cryptococcal granulomas to inner walls of the large to medium-sized
veins of various organs, including the lungs, liver and spleen. In order to elucidate the pathogenesis of granulomatous changes,
the cells composing the intravascular granulomas were observed by electron microscopic peroxidase (PO) cytochemistry. The
granuloma composing cells could be divided into the following four types according to the pattern of endogenous peroxidase
activity: exudate macrophage (Mφ, type I), PO-negative Mφ (type II), resident Mφ (type III) and other inflammatory cells (type
IV). In the intravenous granulomas of the lung, the percentages of composed cells were 39.0% for type I, 57.9% for type II,
0% for type III and 3.1% for type IV. By contrast, in the interstitial granulomas in the lung, type III Mφs, possibly derived
from alveolar Mφs, played a significant role in granuloma formation. This may indicate that the intravascular granuloma is
almost composed of macrophages derived from monocytes rather than alveolar macrophages. The expression of ICAM-1 on endothelia
of the pulmonary veins was examined by immunoelectron microscopy. An immunogold labeling index was significantly augmented
on the surface of endothelia in response to intravenous challenge ofC. neoformans. The intravascular granuloma demonstrates that the monocytes develop into the granuloma-composing macrophages and suppress
the cryptococcal activities even hi the peripheral blood resulting in an assistance of endothelial functions. 相似文献
38.
The effects of dwarf bamboo,Sasa, cover on the initial morrality of hardwood seedlings were investigated by transplanting 1-year-old beech (Fagus crenata) and current-year oak (Quercus mongolica var.grosseserrata) seedling to three different stands; old-growth beech and secondary oak forests withSasa undergrowth, and aSasa grassland in a grassland-forest series near the top of Mt Jippo, southwestern Japan. The most frequent cause of seedling
morrality was gnawing of the stems by rodents. In the beech forest, the gnawing was more likely to occur underSasa cover, suggesting that it provides a good habitat for rodents on the beech forest floor. TheSasa under growth may thus play an imporrant role in regeneration of beech forest. In the oak floor, mortality of both species
was low and only a little gnawing occurred during a year. However, no natural oak seedling were found in the forest even after
a mast year. This may be because most of the acorns disappeated before establishment. The early-stage demography of hardwood
seedling as oak may thus play an imporrant role in regeneration of oak forest. In theSasa grassland where the seed supply is small, almost all of the seedlings died fromo gnawing regardless of the presence ofSasa cover. These factors prevent the recruitment of a sizable seedling bank. Rodents may thus play an imporrant role in maintenance
of theSasa grassland. 相似文献
39.
Superficial cells of the oral mucosal epithelium in the carp and the cytoskeleton of the epithelial cells are examined by scanning and transmission electron microscopy. Microridges are formed on the surface of the epithelium. Epithelial cells contain two types of vesicles: mucous secretory vesicles and coated vesicles. Most of the mucous vesicles are situated in the center of the cell near the Golgi apparatus. In freeze-fracture replicas, intramembranous particles are abundant in the membranes of the secretory vesicles but rare in the apical plasma membrane. Coated vesicles are situated in the apical and subapical cytoplasm. A great number of thick filaments, considered to be keratin filaments, run randomly throughout the cell to form a meshwork. Thick filaments, which are sparse in the central cytoplasm, are connected to the membranes of the secretory vesicles and other membranous organelles. A layer of closely packed thin filaments, considered to be actin filaments, is found just beneath the apical plasma membrane. Microtubules also occur in the apical cytoplasm and run almost parallel to the cell surface. Both kinds of vesicles are connected to the thin and thick filaments. Their functional significance in the regulation of membrane at the free surface is discussed. 相似文献
40.
It has been proposed that peg formation in the vascular transition region (TR zone) between the hypocotyl and the root in
Cucurbitaceae seedlings is a gravimorphogenetic phenomenon. Initiation of the peg became visible 36 h after imbibition when
cucumber (Cucumis sativus L. cv. Burpee Hybrid II) seeds were germinated in a horizontal position at 24°C in the dark. Simultaneously, sedimented amyloplasts
(putative statoliths) were apparent in the sheath cells surrounding the vascular strands, and in the cortical cells immediately
adjacent to them, in the TR zone. In contrast, the other cortical cells, some of which were destined to develop into the peg,
contained amyloplasts which were not sedimented. These results suggest that the graviperception mechanism for peg formation
may be like that of statoliths in shoot gravitropism. By 48 h following imbibition, the cells of the TR zone still had sedimented
amyloplasts but had lost their sensitivity to gravity, possibly because of their maturation. 相似文献