全文获取类型
收费全文 | 305篇 |
免费 | 16篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 24篇 |
2011年 | 30篇 |
2010年 | 14篇 |
2009年 | 7篇 |
2008年 | 24篇 |
2007年 | 31篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 18篇 |
2003年 | 17篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1994年 | 4篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 4篇 |
排序方式: 共有321条查询结果,搜索用时 31 毫秒
61.
Drizin I Gomtsyan A Bayburt EK Schmidt RG Zheng GZ Perner RJ DiDomenico S Koenig JR Turner SC Jinkerson TK Brown BS Keddy RG McDonald HA Honore P Wismer CT Marsh KC Wetter JM Polakowski JS Segreti JA Jarvis MF Faltynek CR Lee CH 《Bioorganic & medicinal chemistry》2006,14(14):4740-4749
Novel 5,6-fused heteroaromatic ureas were synthesized and evaluated for their activity as TRPV1 antagonists. It was found that 4-aminoindoles and indazoles are the preferential cores for the attachment of ureas. Bulky electron-withdrawing groups in the para-position of the aromatic ring of the urea substituents imparted the best in vitro potency at TRPV1. The most potent derivatives were assessed in in vivo inflammatory and neuropathic pain models. Compound 46, containing the indazole core and a 3,4-dichlorophenyl group appended to it via a urea linker, demonstrated in vivo analgesic activity upon oral administration. This derivative also showed selectivity versus other receptors in the CEREP screen and exhibited acceptable cardiovascular safety at levels exceeding the therapeutic dose. 相似文献
62.
Gill, trunk kidney, spleen, and liver of rainbow trout (Oncorhynchus mykiss) were examined after exposure to different sublethal concentrations of carbosulfan (25, 50 and 200 μg L−1), propineb (3, 6 and 24 mg L−1), and benomyl (2, 5 and 20 mg L−1) for 14 days. Lesions were observed in gill, trunk kidney, spleen, and liver of rainbow trout exposed to either concentration of pesticides. The most important lesions were determined in the highest concentrations of pesticides. Lamellar fusion, lamellar hyperplasia, epithelial lifting, vacuolization of epithelial tissue, epithelial necrosis, hypertrophy and sloughing of epithelium were observed on fish exposed to carbosulfan, propineb and benomyl. Fish had cell necrosis, degeneration and oedemas in liver, trunk kidney and spleen. None of these lesions were seen in control fish. 相似文献
63.
64.
Previous studies on cognitive dynamics showed that oscillatory responses of P300 are composed of mainly delta and theta responses.
In the present study, for the first time, the long-distance intra-hemispheric event related coherence (auditory oddball paradigm)
and evoked coherence (simple sound) were compared in order to evaluate the effects of cognitive tasks on the long-distance
coherences. Seventeen healthy subjects (8 female, 9 male) were included in the study. The coherence was analyzed for delta (1–3.5 Hz), theta (4–7.5 Hz) and alpha (8–13 Hz) frequency ranges for (F3-P3, F4-P4, F3-T7, F4-T8, F3-O1, F4-O2) electrode pairs. The coherence to target responses were higher than the non-target and simple auditory response coherence. This difference is significant for the delta coherence for both hemispheres and for
theta coherences over the left hemisphere. The highest coherences were recorded at fronto-temporal locations for all frequency
bands (delta, theta, alpha). Furthermore, fronto-parietal coherences were higher than the fronto-occipital coherences for
all frequency bands (delta, theta, alpha).These results show that the fronto-temporal and fronto-parietal connections are
most relevant for the identification of the target signal. This analysis open the way for a new interpretation of dynamic
localization results during cognitive tasks. 相似文献
65.
Menotta M Pierleoni R Amicucci A Sisti D Cerasi A Millo E Chiarantini L Stocchi V 《Molecular genetics and genomics : MGG》2006,276(2):126-134
Mitogen-activated protein kinases (MAPK) are used by organisms to transduce extra cellular signals from the environment in cellular events such as proliferation and differentiation. In the present study, we have characterized the first MAPK from the ectomycorrhizal fungus Tuber borchii (TBMK) which belongs to the YERK1 (yeast extra cellular regulated kinase) subfamily. TBMK is present as a single copy in the genome and the codified protein was phosphorylated during the interaction with the host plant, Tilia americana. Complementation studies showed that TBMK restores pheromone signaling in Saccharomyces cerevisiae and partially restores invasive growth of Fusarium oxysporum that lack the fmk1 gene. This suggests a protein kinase activity and its involvement in the infection processes. Hence, TBMK could play an important role during the pre-symbiotic phase of T. borchii with its host plant in the modulation of genes necessary for the establishment of symbiosis leading to the synthesis of functional ectomycorrhizae. 相似文献
66.
A Babesia microti hsp70 homologue was cloned, expressed in a prokaryotic system and tested in a pilot study for protection against lethal challenge. Results showed that 30% of the mice inoculated with recombinant protein (rBm hsp70) survived challenge, while all of the controls died. Evidence of antibody response to the hsp homologue was detected by Western blot analysis, but no protection was imparted through passive transfer of convalescent serum. Passively transferred spleen cells, from mice which survived challenge, also failed to impart protection. The mechanism of partial immunity suggested by these observations remains to be elucidated. 相似文献
67.
68.
Effects of ingesting garlic extract on plasma and erythrocyte antioxidant parameters of atherosclerotic patients were investigated in this study. Eleven patients with atherosclerosis participated in the study. They ingested a dose of 1 ml/kg body weight of garlic extract daily for 6 months (study period). Before and after this period, fasting blood samples were obtained, and oxidant (malondialdehyde, MDA and xanthine oxidase, XO) and antioxidant (superoxide dismutase, SOD and glutathione peroxidase, GSH-Px) parameters were studied in plasma and erythrocytes obtained from the patients. Blood samples obtained from 11 healthy subjects served as the controls. Plasma XO activity and MDA levels were higher, but plasma and erythrocyte GSH-Px activities were lower, in patients with atherosclerosis relative to those of the control group. Our results showed that ingestion of garlic extract leads to significantly lowered plasma and erythrocyte MDA levels in the patients even in the absence of changes in antioxidant enzyme activities. Our results also demonstrated the presence of oxidant stress in blood samples from patients with atherosclerosis, but ingesting garlic extract prevented oxidation reactions by eliminating this oxidant stress. Thus, it is possible that reduced peroxidation processes may play a part in some of the beneficial effects of garlic in atherosclerotic diseases. 相似文献
69.
Invasion and survival strategies of Anaplasma phagocytophilum 总被引:4,自引:4,他引:0
Anaplasma phagocytophilum is an aetiological agent of human granulocytic ehrlichiosis, an emerging tick‐borne zoonosis in the United States and Europe. This obligate intracellular bacterium is unique in that it colonizes polymorphonuclear leucocytes (neutrophils). Neutrophils are key players in innate immunity. These short‐lived phagocytes ingest invading microorganisms and destroy them by various means, which include fusing the bacteria‐containing phagosome with acidic lysosomes as well as directing toxic oxidative and proteolytic compounds into the phagosomal lumen. Its tropism for neutrophils indicates that A. phagocytophilum uses strategies for evading and/or neutralizing these microbicidal activities. This review focuses on some of the mechanisms that A. phagocytophilum uses for neutrophil adhesion, surviving within the hostile intracellular environment of its host neutrophil and for effectively disseminating to naïve host cells. 相似文献
70.
Borrelia burgdorferi sensu lato is the causative agent of Lyme disease, which afflicts both humans and some domestic animals. B. burgdorferi, a highly evolved extracellular pathogen, uses several strategies to survive in a complex enzootic cycle involving a diverse range of hosts. This review focuses on the unique adaptive features of B. burgdorferi, which are central to establishing a successful spirochetal infection within arthropod and vertebrate hosts. We also discuss the regulatory mechanisms linked with the development of molecular adaptation of spirochetes within different host environments. 相似文献