全文获取类型
收费全文 | 803篇 |
免费 | 37篇 |
国内免费 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 4篇 |
2021年 | 8篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 5篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 25篇 |
2014年 | 29篇 |
2013年 | 65篇 |
2012年 | 44篇 |
2011年 | 50篇 |
2010年 | 36篇 |
2009年 | 35篇 |
2008年 | 49篇 |
2007年 | 38篇 |
2006年 | 51篇 |
2005年 | 40篇 |
2004年 | 51篇 |
2003年 | 49篇 |
2002年 | 39篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 12篇 |
1997年 | 17篇 |
1996年 | 9篇 |
1995年 | 13篇 |
1994年 | 7篇 |
1993年 | 7篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 6篇 |
1989年 | 12篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
排序方式: 共有841条查询结果,搜索用时 15 毫秒
831.
Hiromi Mutsuura Kenji Kanbara Mikihiko Fukunaga Kazumi Yamamoto Ikumi Ban Kana Kitamura Yoshihide Nakai 《Applied psychophysiology and biofeedback》2009,34(4):291-298
Patients presenting with functional somatic syndrome (FSS) are common, and the symptoms are persistent and difficult to treat
for doctors and costly for society. The aim of this study was to clarify the common pathophysiology of FSS, especially the
relationship between hypothalamic-pituitary-adrenal (HPA) axis function and psychological characteristics of patients with
FSS. The subjects were 45 patients with FSS and 29 healthy controls. Salivary free cortisol was measured in the morning, and
psychological tests examining depression, anxiety and quality of life (QOL) were performed on the same day. In patients with
FSS, depressive scores showed a significant negative correlation with salivary free cortisol in the morning, although in healthy
controls, cortisol showed a significant positive correlation with depressive scores. In addition, the correlation between
other psychological test scores and cortisol secretion in patients with FSS contrasted with that of controls. The relationship
between cortisol and depression, anxiety or QOL, suggests that the HPA axis of patients with FSS is dysfunctional and does
not function properly when patients with FSS are under stress. This dysfunction may explain the pathology of medically unexplained
persistent symptoms of patients with FSS. 相似文献
832.
833.
Summary Cecum from chickens, 4 wk old, can best be maintained for 24 h in a serum-free organ culture system using Trowell T8 medium
agar sheet at 25°C. As determined by light microscopy as well as scanning and transmission electron microscopy, mucosal architecture
involving classic ultrastructure of chicken cecal mucosa was preserved. Protein content of cecal explants did not change up
to 48 h of culture. DNA content of cecal explants did not change up to 24 h of culture but decreased significantly to two-thirds
of control in 48 h of culture. Based on the morphologic and physiologic findings, it became evident that this organ culture
system using Trowell T8 medium at 25°C can be successfully used as an in vitro experimental model for as long as 24 h. The
organ culture system could be a useful tool, from the structural integrity of ceca observed in this study, in investigating
mucosal function and mucosal response to drugs, carcinogens, trophic factors, and pathogens. 相似文献
834.
Kiyoshi Tanaka Tomoko Sano Kozo Ishizuka Kazumi Kitta Yukio Kawamura 《Physiologia plantarum》1994,91(3):353-358
Glutathione reductase (GR; EC 1.6.4.2) was purified from spinach roots (rGR) to homogeneity in terms of SDS-PAGE, and its properties were compared with those of the enzyme from spinach leaves (IGR). The two enzymes had similar native molecular (118000) and subunit masses (58000) and immunochemical properties, but different pH optima (ca pH 7.8 for IGR, ca pH 7.2 for rGR) and amino acid compositions. Peptide maps of two GRs showed that they differed from each other. The N-terminal amino acid of the IGR was glycine and that of the rGR was blocked. The partial amino acid sequence of the N-terminal region of the IGR was determined to the 11 th residue and it was found that the sequence of 8 amino acids of the IGR had 100% homology with that of the putative chloroplast GR from Arabidopsis and pea. 相似文献
835.
836.
Hossain Shahdat Hussain Jakir Bhowmick Sujan Sarkar Marzan Basunia Mafroz Al Mamun Abdullah Tanabe Yoko Matsuzaki Kentaro Hashimoto Michio Shido Osamu 《Biological trace element research》2020,194(2):525-535
Biological Trace Element Research - Selenomethionine is able to relieve the effect of inflammation in various tissues and organs. However, there are few studies about the influences of organic... 相似文献
837.
The conventional methods of gas liquid chromatography or mass spectrometry failed to be useful for the identification of the biliary 3β, 7α-hydroxychol--en-24-oic acid, a key intermediate of chenodeoxycholic acid biogenesis. It has been preliminarily reported that this acid in human bile was successfully identified by gas chromatography-mass spectrometry, after the methoxylation of its allyl alcohol group. Physical as well as spectral properties of the methoxylation products derived from the acid were reported, compared with those from its 7β-epimer. 相似文献
838.
Ryosuke Fukada Yukimasa Yamagishi Misaki Nagasaka Daiki Osada Kazumi Nimura Iori Oshima Kazuki Tsujimoto Masayuki Kirihara Shinobu Takizawa Norio Kikuchi Takahiro Ishii Takashi Kamada 《化学与生物多样性》2023,20(8):e202300888
The marine red algal genus Laurencia has abundant halogenated secondary metabolites, which exhibit novel structural types and possess various unique biological potentials, including antifouling activity. In this study, we report the isolation, structure elucidation, and antifouling activities of two novel brominated diterpenoids, aplysin-20 aldehyde ( 1 ), 13-dehydroxyisoaplysin-20 ( 2 ), and its congeners. We screened marine red alga Laurencia venusta Yamada for their antifouling activity against the mussel Mytilus galloprovincialis. Ethyl acetate extracts of L. venusta from Hiroshima and Chiba, Japan, were isolated and purified, and the compound structures were identified using 1D and 2D NMR, HR-APCI-MS, IR, and chemical synthesis. Seven secondary metabolites were identified, and their antifouling activities were evaluated. Compounds 1 , 2 , and aplysin-20 ( 3 ) exhibited strong activities against M. galloprovincialis. Therefore, these compounds can be explored as natural antifouling drugs. 相似文献
839.
Shuji Matsumoto Megumi Shimodozono Seiji Etoh Yurika Shimozono Nobuyuki Tanaka Kazumi Kawahira 《International journal of biometeorology》2010,54(4):465-473
Footbaths are considered to provide beneficial thermal therapy for post-stroke patients with spasticity, but their anti-spastic
effects have not been investigated comprehensively. The present study aimed to evaluate alterations in motor-neuron excitability
using F-wave parameters in post-stroke patients with spastic hemiplegia. Subjects’ legs below the knee joint were immersed
in water at 41°C and F-wave recordings were made over the abductor hallucis muscle before, immediately after, and 30 min after
thermal treatment. Antidromic stimulation was performed on the tibial nerve at the ankle. Measurements included F-wave amplitude,
F-wave/M-response ratio, changes in modified Ashworth scale (MAS), body temperature and surface-skin temperature. The mean
values of both F-wave parameters were higher on the affected side before footbath treatment. In post-stroke patients, the
mean values of F-wave parameters were significantly reduced after footbath treatment (P < 0.01). The anti-spastic effects of footbath treatment were indicated by decreased F-wave parameters, in parallel with decreases
in MAS. Body temperature was significantly increased both immediately after, and 30 min following footbath treatment in both
groups, which appeared to play an important role in decreased spasticity. Surface-skin temperature increased immediately after
footbath treatment in both groups and returned to baseline 30 min later. These findings demonstrate that the use of footbaths
is an effective nonpharmacological anti-spastic treatment that might facilitate stroke rehabilitation. 相似文献
840.
Relative contribution of bacterial and photosynthetic production to metazooplankton as carbon sources 总被引:1,自引:0,他引:1
Koshikawa Hiroshi; Harada Shigeki; Watanabe Masataka; Sato Kazumi; Akehata Koji 《Journal of plankton research》1996,18(12):2269-2281
Percentages of label transfer (PLT) from bacteria and autotrophsto metazooplankton during 4 h were determined in parallel usingdissolved organic and inorganic13C tracers, respectively, inin situ batch incubations, to estimate the relative contributionof each production to the metazooplankton food requirement.The batch incubation for each pathway was done eight times,respectively, during 20 days in a mesocosm where continuousspecies succession of organisms was observed. The PLT in thetwo pathways, dependent on metazooplankton abundance and speciescomposition rather than changes in the activities of producers(bacteria or autotrophs), showed a similar tendency of changeand were of a similar magnitude: mean 1.0% (0.092.7%)in the photosynthetic pathway and 0.5% (0.221.5%) inthe bacterial pathway. This finding suggests that metazooplanktonare supported by entire microbial food webs including both thebacterial and photosynthetic pathways. 相似文献