全文获取类型
收费全文 | 580篇 |
免费 | 27篇 |
国内免费 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 12篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 16篇 |
2017年 | 14篇 |
2016年 | 22篇 |
2015年 | 30篇 |
2014年 | 37篇 |
2013年 | 46篇 |
2012年 | 73篇 |
2011年 | 63篇 |
2010年 | 24篇 |
2009年 | 32篇 |
2008年 | 37篇 |
2007年 | 23篇 |
2006年 | 26篇 |
2005年 | 24篇 |
2004年 | 23篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1994年 | 3篇 |
1987年 | 3篇 |
1984年 | 2篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 2篇 |
1958年 | 2篇 |
1957年 | 1篇 |
1956年 | 2篇 |
1954年 | 2篇 |
1950年 | 2篇 |
排序方式: 共有608条查询结果,搜索用时 31 毫秒
1.
Yoshifumi Abe Atsuhiko Matsunaga Ryota Matsuzawa Toshiki Kutsuna Shuhei Yamamoto Kei Yoneki Manae Harada Ryoma Ishikawa Takaaki Watanabe Atsushi Yoshida 《PloS one》2016,11(3)
Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients. 相似文献
2.
The present work was undertaken to find if there are relations between light and auxin action on elongation of coleoptilar node and mesocotyl with Avena seedlings. Red light inhibited the elongation of mesocotyl and simultaneously decreased the rate of transport of diffusible auxin through the node. Red light also inhibited the transport of exogenously given IAA through the nodal region. The light inhibition of IAA transport was closely related to the increase of IAA immobilization. As the age proceeds, the ability of IAA immobilization increased with the decrease in the rate of mesocotyl elongation, even if the seedling was grown in complete darkness. The nature of radioactive substances found in the IAA-C14 treated tissue was examined by paper chromatography. The above results strongly suggested that the increase of IAA immobilization might result in the inhibition of mesocotyl elongation. 相似文献
3.
GORO KOKUBUGATA KATSUHIKO KONDO F.L.S. 《Botanical journal of the Linnean Society. Linnean Society of London》1996,120(1):51-55
Similar karyotypes of In = 22 in Cycas circinalis, C. media var. basaltica, C. revoluia var. rewluta, C. revoluta var. taiwaniana and C. siammsis were compared with each other by using the CMA and DAPI fluorescent staining methods. Their four largest submedian-centromeric chromosomes each had a CMA band at the terminal region in common. Their 12 terminal-centromeric chromosomes commonly displayed CMA bands at the terminal region and the pericentric region. Two of the 12 terminal-centromeric chromosomes carried a CMA band somewhere in the interstitial region of the long arm. C. circinalis alone showed it at a relative position closer to the centromere. The other taxa showed it at a relative position near the terminal region. All of the chromosomes exhibited the DAPI dot at the centromeric region. 相似文献
4.
金花茶(Camellia petelotii)的小孢子单核期花药,经培养和继代培养6个月后的愈伤组织中,发现有少量体细胞进行减数分裂。在减数第一和第二次分裂中,同源染色体的配对和分离基本正常,最后形成四分体。该愈伤组织经石蜡切片和压片观察,发现其主要由大量的液化细胞和贮藏细胞所组成,此外,还有少部分分生细胞。没有发现进一步的分化。其染色体数目,2n=30者占71.7%其余则为非整倍体。 相似文献
5.
6.
Tokimatsu Koji Tang Longlong Yasuoka Rieko Ii Ryota Itsubo Norihiro Nishio Masahiro 《The International Journal of Life Cycle Assessment》2020,25(9):1710-1736
The International Journal of Life Cycle Assessment - Despite the long-standing demand for research on dynamic lifecycle assessment (LCA) for policymaking, only a few studies have addressed this... 相似文献
7.
Takemura Aya Matsumoto Junya Hashimoto Ryota Kawano Kenji Miura Kenichiro 《Journal of computational neuroscience》2021,49(3):273-282
Journal of Computational Neuroscience - When two-frame apparent motion stimuli are presented with an appropriate inter-stimulus interval (ISI), motion is perceived in the direction opposite to the... 相似文献
8.
9.
10.
Ikuko Kusaba Takahiro Nakao Hiroko Maita Shusei Sato Ryota Chijiiwa Emi Yamada Susumu Arima Mareshige Kojoma Kanji Ishimaru Ryo Akashi Akihiro Suzuki 《Plant Biotechnology》2021,38(1):57
Licorice (Glycyrrhiza uralensis) is a medicinal plant that contains glycyrrhizin (GL), which has various pharmacological activities. Because licorice is a legume, it can establish a symbiotic relationship with nitrogen-fixing rhizobial bacteria. However, the effect of this symbiosis on GL production is unknown. Rhizobia were isolated from root nodules of Glycyrrhiza glabra, and a rhizobium that can form root nodules in G. uralensis was selected. Whole-genome analysis revealed a single circular chromosome of 6.7 Mbp. This rhizobium was classified as Mesorhizobium by phylogenetic analysis and was designated Mesorhizobium sp. J8. When G. uralensis plants grown from cuttings were inoculated with J8, root nodules formed. Shoot biomass and SPAD values of inoculated plants were significantly higher than those of uninoculated controls, and the GL content of the roots was 3.2 times that of controls. Because uninoculated plants from cuttings showed slight nodule formation, we grew plants from seeds in plant boxes filled with sterilized vermiculite, inoculated half of the seedlings with J8, and grew them with or without 100 µM KNO3. The SPAD values of inoculated plants were significantly higher than those of uninoculated plants. Furthermore, the expression level of the CYP88D6 gene, which is a marker of GL synthesis, was 2.5 times higher than in inoculated plants. These results indicate that rhizobial symbiosis promotes both biomass and GL production in G. uralensis. 相似文献