全文获取类型
收费全文 | 1758篇 |
免费 | 158篇 |
出版年
2022年 | 14篇 |
2021年 | 16篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 16篇 |
2017年 | 24篇 |
2016年 | 23篇 |
2015年 | 38篇 |
2014年 | 60篇 |
2013年 | 130篇 |
2012年 | 77篇 |
2011年 | 94篇 |
2010年 | 53篇 |
2009年 | 62篇 |
2008年 | 82篇 |
2007年 | 120篇 |
2006年 | 101篇 |
2005年 | 100篇 |
2004年 | 83篇 |
2003年 | 68篇 |
2002年 | 91篇 |
2001年 | 44篇 |
2000年 | 43篇 |
1999年 | 57篇 |
1998年 | 28篇 |
1997年 | 26篇 |
1996年 | 16篇 |
1995年 | 26篇 |
1994年 | 19篇 |
1993年 | 12篇 |
1992年 | 35篇 |
1991年 | 18篇 |
1990年 | 24篇 |
1989年 | 21篇 |
1988年 | 25篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 14篇 |
1984年 | 24篇 |
1983年 | 12篇 |
1982年 | 25篇 |
1981年 | 12篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1978年 | 10篇 |
1977年 | 17篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1972年 | 7篇 |
排序方式: 共有1916条查询结果,搜索用时 31 毫秒
91.
Junichi Ueda Takao Yokota Nobutaka Takahashi Michio Yoshida Jiro Kato 《Bioscience, biotechnology, and biochemistry》2013,77(12):3083-3086
A root growth-promoting factor was isolated from Artemisia capillaris Thunb. The chemical structure of this compound was elucidated as methyl 3-(3-methylbut-2-enoyl)-4-hydroxycinnamate (capillarol) on the basis of its spectroscopic analysis. At 5×10–4m this compound promoted rice root growth to 180% of the control value. 相似文献
92.
Ryosuke Tateishi Shuichiro Shiina Masaaki Akahane Jiro Sato Yuji Kondo Ryota Masuzaki Hayato Nakagawa Yoshinari Asaoka Tadashi Goto Kuni Otomo Masao Omata Haruhiko Yoshida Kazuhiko Koike 《PloS one》2013,8(4)
Background
In the treatment of hepatocellular carcinoma (HCC), hepatic resection has the advantage over radiofrequency ablation (RFA) in terms of systematic removal of a hepatic segment.Methods
We enrolled 303 consecutive patients of a single naïve HCC that had been treated by RFA at The University of Tokyo Hospital from 1999 to 2004. Recurrence was categorized as either intra- or extra-subsegmental as according to the Couinaud''s segment of the original nodule. To assess the relationship between the subsegments of the original and recurrent nodules, we calculated the kappa coefficient. We assessed the risk factors for intra- and extra-subsegmental recurrence independently using univariate and multivariate Cox proportional hazard regression. We also assessed the impact of the mode of recurrence on the survival outcome.Results
During the follow-up period, 201 patients in our cohort showed tumor recurrence distributed in a total of 340 subsegments. Recurrence was categorized as exclusively intra-subsegmental, exclusively extra-subsegmental, and simultaneously intra- and extra-subsegmental in 40 (20%), 110 (55%), and 51 (25%) patients, respectively. The kappa coefficient was measured at 0.135 (95% CI, 0.079–0.190; P<0.001). Multivariate analysis revealed that of the tumor size, AFP value and platelet count were all risk factors for both intra- and extra-subsegmental recurrence. Of the patients in whom recurrent HCC was found to be exclusively intra-subsegmental, extra-subsegmental, and simultaneously intra- and extra-subsegmental, 37 (92.5%), 99 (90.8%) and 42 (82.3%), respectively, were treated using RFA. The survival outcomes after recurrence were similar between patients with an exclusively intra- or extra-subsegmental recurrence.Conclusions
The effectiveness of systematic subsegmentectomy may be limited in the patients with both HCC and chronic liver disease who frequently undergo multi-focal tumor recurrence. 相似文献93.
94.
95.
A petal‐specific InMYB1 promoter from Japanese morning glory: a useful tool for molecular breeding of floricultural crops
下载免费PDF全文
![点击此处可从《Plant biotechnology journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mana Hirose Yasumasa Morita Atsushi Hoshino Shigeru Iida Yoshimi Oshima Nobutaka Mitsuda Masaru Ohme‐Takagi Katsuhiro Shiratake 《Plant biotechnology journal》2016,14(1):354-363
Production of novel transgenic floricultural crops with altered petal properties requires transgenes that confer a useful trait and petal‐specific promoters. Several promoters have been shown to control transgenes in petals. However, all suffer from inherent drawbacks such as low petal specificity and restricted activity during the flowering stage. In addition, the promoters were not examined for their ability to confer petal‐specific expression in a wide range of plant species. Here, we report the promoter of InMYB1 from Japanese morning glory as a novel petal‐specific promoter for molecular breeding of floricultural crops. First, we produced stable InMYB1_1kb::GUS transgenic Arabidopsis and Eustoma plants and characterized spatial and temporal expression patterns under the control of the InMYB1 promoter by histochemical β‐glucuronidase (GUS) staining. GUS staining patterns were observed only in petals. This result showed that the InMYB1 promoter functions as a petal‐specific promoter. Second, we transiently introduced the InMYB1_1 kb::GUS construct into Eustoma, chrysanthemum, carnation, Japanese gentian, stock, rose, dendrobium and lily petals by particle bombardment. GUS staining spots were observed in Eustoma, chrysanthemum, carnation, Japanese gentian and stock. These results showed that the InMYB1 promoter functions in most dicots. Third, to show the InMYB1 promoter utility in molecular breeding, a MIXTA‐like gene function was suppressed or enhanced under the control of InMYB1 promoter in Arabidopsis. The transgenic plant showed a conspicuous morphological change only in the form of wrinkled petals. Based on these results, the InMYB1 promoter can be used as a petal‐specific promoter in molecular breeding of floricultural crops. 相似文献
96.
Naoyuki Okuda Hiroyuki Inoue Kazuhiko Ishikawa Tamotsu Hoshino 《Bioscience, biotechnology, and biochemistry》2016,80(10):2065-2068
We obtained strains with the xylanase regulator gene, xlnR, overexpressed (HXlnR) and disrupted (DXlnR) derived from Talaromyces cellulolyticus strain C-1, which is a cellulase hyperproducing mutant. Filter paper degrading enzyme activity and cellobiohydrolase I gene expression was the highest in HXlnR, followed by C-1 and DXlnR. These results indicate that the enhancement of cellulase productivity was succeeded by xlnR overexpression. 相似文献
97.
Hoshino Shotaro Onaka Hiroyasu Abe Ikuro 《Journal of industrial microbiology & biotechnology》2019,46(3-4):363-374
Journal of Industrial Microbiology & Biotechnology - Bacterial secondary metabolites (SM) are rich sources of drug leads, and in particular, numerous metabolites have been isolated from... 相似文献
98.
The objective of this study was to develop an ideal freezing extender and method for rat epididymal sperm cryopreservation. Epididymal sperm collected from 30 Wistar males was frozen, and experiments were conducted to study its post-thaw characteristics when freezing with raffinose-free buffer or various concentrations of raffinose and egg yolk dissolved in distilled and deionised water, PBS, or modified Krebs–Ringer bicarbonate (mKRB)-based extender. Different concentrations of glycerol, Equex STM, or sodium dodecyl sulfate (SDS) dissolved in either PBS or mKRB containing egg yolk were also tested. Based on the data from these experiments, further experiments tested how different sugars such as raffinose, trehalose, lactose, fructose, and glucose dissolved in mKRB with Equex STM, SDS and egg yolk supplementation affected the post-thaw characteristics of cryopreserved sperm. Cryosurvival of frozen-thawed sperm were judged by microscopic assessment of the sperm motility index (SMI), and acrosome integrity was measured using FITC-PNA staining. Thawed sperm were subjected to 3 h of a thermal resistance test. Beneficial effects on the post-thaw survival of sperm were obtained when 0.1 M raffinose in mKRB was used with 0.75% Equex STM, 0.05% SDS, and 20% egg yolk. Sperm cryopreserved with this treatment exhibited a higher motility index and maintained greater SMI and acrosome integrity throughout incubation when compared to sperm frozen in various concentrations of other cryoprotectants and trehalose, lactose, fructose, glucose. In conclusion, cryopreservation in an extender solution of raffinose dissolved in mKRB containing Equex STM, SDS and egg yolk greatly enhances the freezability of rat epididymal sperm. 相似文献
99.
Taking advantage of the phenomenon of bioluminescence resonance energy transfer (BRET), we developed a bioluminescent probe composed of EYFP and Renilla reniformis luciferase (RLuc)--BRET-based autoilluminated fluorescent protein on EYFP (BAF-Y)--for near-real-time single-cell imaging. We show that BAF-Y exhibits enhanced RLuc luminescence intensity and appropriate subcellular distribution when it was fused to targeting-signal peptides or histone H2AX, thus allowing high spatial and temporal resolution microscopy of living cells. 相似文献