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661.
Bruce R. Wolff Bernard R. Glick J. J. Pasternak 《Journal of industrial microbiology & biotechnology》1990,6(4):285-289
Summary The DNA of two previously isolated recombinant clones, one fromPseudomonas sp. NCIB 8634 (=Cellvibrio mixtus) (pPC71) and another fromPseudomonas fluorescens subsp.cellulosa (pPFC4) that express endoglucanase activity inE. coli was sequenced. Plasmid pPC71 had three open reading frames, two of which include portions of plasmid pBR322. The third open reading frame occurs entirely within thePseudomonas DNA insert and encodes a protein with a molecular mass of 5845 Da. The DNA insert in pPFC4 was found to contain an open reading frame (PFC-ORF) that encodes a protein of 32189 Da. The major endoglucanase produced inE. coli cells carrying pPFC4 is about 30000 Da [26]. It is concluded that PFC-ORF encodes this endoglucanase. Both ribosome and catabolite gene activator protein binding sites lie upstream from the initiating codon of PFC-ORF. An interesting feature of the PFC-ORF protein is the presence of amino acid motifs Val-Ser-Ser-Ser-Ser and Val-Val-Ser-Ser-Ser-Ser-Ser that occur within a 25 amino acid span. 相似文献
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Dilprit Bagga Lauri O. Byerley Brian J. Koziol Zvi Glick Judith M. Ashley David Heber 《The Journal of nutritional biochemistry》1995,6(12):667-672
A high fat diet fed ad libitum will promote breast tumorigenesis in rats while caloric restriction of the same high fat diet counteracts this promotional effect. The present study examined the effects of dietary fat and calorie intake on adipose tissue weight and fatty acid composition and on tumor incidence and development. The sites of adipose tissue chosen were the mammary fat pad, representing adipose tissue in the immediate location of the studied tumor, and the abdominal fat depot which in humans has been associated with an increased risk of breast cancer. High (20% corn oil) and low (5% corn oil) fat test diets were offered ad libitum and at 40% restriction levels. In agreement with prior studies, caloric restriction of both high and low fat diets led to marked decreases in tumor incidence (63 to 68% versus 21%), tumor burden (1.84 to 2.05 versus 0.37 to 0.43 tumors/rat), and tumor weight (7.1 to 11.9 versus 1.4 to 2.2 g) at the time of sacrifice (133 days post-DMBA). While final body weights were reduced in proportion to the level of caloric restriction (290 to 291 g versus 184 to 201 g), abdominal fat (8.8 to 9.2 versus 0.9 to 1.6 g), and mammary fat weights (3.1 to 4.1 versus 0.7 to 2.0 g) were reduced markedly in association with the decrease in tumorigenesis. While both tumor and mammary fat were enriched with linoleate reflecting the fatty acid composition of dietary fat, the ratio of arachidonic acid to linoleic acid was higher in tumor tissue than in surrounding normal mammary tissue in both the phospholipid (0.78 versus 0.18) and neutral lipid fractions (0.22 versus 0.03). These observations are consistent with the concept that increases in fat tissue mass in abdominal and mammary fat depots may mediate some of the promotional effects of high fat and high calorie diets. Restriction of dietary fat and calories to reduce body fat and strategies to modify the composition of stored lipids in fat depots may offer nutritional approaches to breast cancer prevention and treatment. 相似文献
667.
Sex differences in Japanese macaques (Macaca fuscata): effects of prenatal testosterone on juvenile social behavior 总被引:1,自引:0,他引:1
The aim of this study was to assess, in a nonhuman primate, the extent to which exposure to androgen during the prenatal period interacts with early social experience to affect the display of male or female patterns of behavior. Pregnant females from a large age-graded, heterosexual group of Japanese macaques (Macaca fuscata) were implanted about the 40th day of gestation with Silastic packets of testosterone. The packets were removed on the 100th day of gestation, and the females were allowed to give birth in their outdoor corral. An unplanned procedural change, by the surgeon who did the implants, created two groups of prenatally androgenized females: a high-dose group (N = 3), and a low-dose group (N = 4). The anatomical differentiation of these groups differed in that the high-dose group had small penises and no vaginas while the low-dose group had enlarged clitorises and patent vaginas. The behavior of these two groups of females was compared with that of normal males (N = 6), prenatally androgenized males (N = 6), and normal females (N = 5) from birth to 2 years of age. There were no differences between treated and normal males, but there were sex differences between males and normal females in the frequency of mounting, playing, displaying, and grooming. The high-dose group of prenatally androgenized females differed from normal females on only one measure: increased frequency of mounting. The low-dose group mounted other juveniles more frequently than did the normal females, but the difference was not statistically significant. We concluded that mounting behavior was most sensitive to the prenatal hormone environment because it showed the largest sex difference in normal animals. Given the small sample sizes, within-group variability could have obscured possible hormonal effects on other behaviors where sex differences were less dramatic. 相似文献