全文获取类型
收费全文 | 1496篇 |
免费 | 110篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 10篇 |
妇产科学 | 20篇 |
基础医学 | 247篇 |
口腔科学 | 22篇 |
临床医学 | 78篇 |
内科学 | 427篇 |
皮肤病学 | 58篇 |
神经病学 | 91篇 |
特种医学 | 41篇 |
外科学 | 210篇 |
综合类 | 9篇 |
预防医学 | 28篇 |
眼科学 | 29篇 |
药学 | 129篇 |
中国医学 | 11篇 |
肿瘤学 | 152篇 |
出版年
2023年 | 9篇 |
2022年 | 22篇 |
2021年 | 40篇 |
2020年 | 28篇 |
2019年 | 31篇 |
2018年 | 43篇 |
2017年 | 44篇 |
2016年 | 39篇 |
2015年 | 49篇 |
2014年 | 61篇 |
2013年 | 68篇 |
2012年 | 103篇 |
2011年 | 93篇 |
2010年 | 58篇 |
2009年 | 58篇 |
2008年 | 78篇 |
2007年 | 96篇 |
2006年 | 71篇 |
2005年 | 91篇 |
2004年 | 71篇 |
2003年 | 63篇 |
2002年 | 72篇 |
2001年 | 32篇 |
2000年 | 34篇 |
1999年 | 17篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 10篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 14篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 20篇 |
1988年 | 12篇 |
1987年 | 17篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1979年 | 4篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1968年 | 6篇 |
1966年 | 6篇 |
1965年 | 3篇 |
排序方式: 共有1627条查询结果,搜索用时 31 毫秒
1.
Air-pouch-type inflammation was induced by injecting sodium carboxymethyl cellulose solution containing leukotriene C4 (LTC4, 3.20 x 10(-7) M, 0.2 micrograms/ml) and prostaglandin E2 (PGE2, 5.68 x 10(-6) M, 2.0 micrograms/ml), platelet-activating factor (PAF, 1 x 10(-6) M, 0.52 micrograms/ml), or 12-O-tetradecanoyl phorbol 13-acetate (TPA, 1.62 x 10(-6) M, 1.0 micrograms/ml) into an air pouch made on the dorsum of rats. Vascular permeability and tissue edema formation were significantly increased by injecting the phlogogen solution. The histamine level in the pouch fluid was dramatically increased by injecting TPA but not by LTC4 and PGE2, or PAF. Injection of isoproterenol or procaterol with the phlogogen solution produced dose-dependent suppression of both vascular permeability increase and tissue edema formation. However, the TPA-induced increase in the histamine level was not suppressed in parallel with the decrease of vascular permeability or tissue edema formation. These results indicate that beta-agonists suppress vascular permeability response and local tissue edema formation not by inhibiting mast cell degranulation, but by inhibiting the reactivity of the local vasculature to chemical mediators such as arachidonate metabolites, PAF, and histamine and serotonin released from mast cells. 相似文献
2.
T Kuwahara T Kudoh H Nagase M Takamiya A Nakano T Ohtsuka H Yoshizaki M Arisawa 《European journal of pharmacology》1992,221(1):99-105
We found a novel nonpeptide CCKB receptor antagonist, tetronothiodin (Ro 09-1468), in the culture broth of Streptomyces sp. NR0489. The structure of the compound (C31O8H38S), which has a 19-membered ring with an alpha-acyltetronic acid and tetrahydrothiophene moiety, is completely different from that of any known CCK receptor antagonist. Tetronothiodin inhibited [125I]CCK-8 binding to rat brain CCKB receptors with an IC50 of 3.6 nM, whereas it showed only weak affinity for rat CCKA receptors (IC50 = 70 microM). As demonstrated autoradiographically, tetronothiodin concentration dependently inhibited [125I]CCK-8 binding to CCKB receptors in rat forebrain slices. The effects of tetronothiodin on cytosolic Ca2+ concentrations in GH3 cells, a rat anterior pituitary tumor cell line, were investigated with the fura-2 method. Tetronothiodin inhibited CCK-8-induced Ca2+ mobilization without affecting basal cytosolic Ca2+ concentrations. In conclusion, tetronothiodin is a new, potent and highly selective CCKB receptor antagonist. It is a useful tool for investigating the pharmacological and physiological roles of CCKB receptors. 相似文献
3.
Keigo Kohara Tomio Ono Keiko Tominaga-Yoshino Tomokazu Shimonaga Seiichi Kawashima Akihiko Ogura 《Brain research》1998,809(2):285
Neurons survive when their activity is maintained. An influential hypothesis on the cellular mechanism underlying this phenomenon is that there is an appropriate range of intracellular Ca2+ concentration ([Ca2+]i) for survival. The rat cerebellar granule neuron in culture serves as the most often used model system for the analysis of activity-dependent survival, since it does not survive unless an excitant (KCl or glutamate) is added to the culture medium. Against the above-mentioned hypothesis, we found in our previous examination no difference between steady-state [Ca2+]i in granule neurons cultured under high KCl (i.e., survival) and low KCl (i.e., death) conditions. In this report, we present the quantitative background of unchanged [Ca2+]i between the two culture conditions. Influx of Ca2+ due predominantly to L-type voltage-dependent calcium channels was higher in high KCl cultures than in low KCl cultures. At the same time, efflux of Ca2+ due to the activity of Ca2+/Na+ antiport was also higher in high KCl cultures. Additionally, we found that the endocytotic activity was greater in high KCl cultures than in low KCl cultures, as monitored by the rate of uptake of horseradish peroxidase added to medium. Since the uptake was blocked by an internal Ca2+ chelator, the increased endocytotic activity in high KCl cultures might be a consequence of the enhanced Ca2+ turnover. 相似文献
4.
Cardiovascular depression occuring when diazepam is combined with fentanyl has been investigated using the benzodiazepine antagonist RO15-1788 in the dog.After the initial administration of fentanyl (40mcg/kg), the mean arterial pressure (MAP) decreased to 89% of its control value. Following the administration of diazepam (1.2mg/kg), the MAP and the total peripheral resistance (TPR) decreased significantly, to 75% and 83% of their control values respectively. After the administration of RO15-1788 (0.4mg/kg), the MAP increased significantly to 90% and the TPR to 102% of their control values and, lastly, the administration of naloxone (40mcg/kg) increased the MAP to 108% of its control value. No relationship was found between the changes in the catecholamines and the changes in the MAP after the administration of fentanyl, diazepam, and RO15-1788.The mechanism of circulatory depression when diazepam was used with fentanyl is interpreted as being a peripheral vasodilatory effect of diazepam acting by way of the benzodiazepine receptors since RO15-1788 was found to antagonize this effect.(Sone T, Kato T, Tsukahara I et al.: The effect of RO15-1788 on cardiovascular depression caused by fentanyl and diazepam. J Anesth 2: 69–76, 1988) 相似文献
5.
Anjali Ramaswamy Nina N. Brodsky Tomokazu S. Sumida Michela Comi Hiromitsu Asashima Kenneth B. Hoehn Ningshan Li Yunqing Liu Aagam Shah Neal G. Ravindra Jason Bishai Alamzeb Khan William Lau Brian Sellers Neha Bansal Pamela Guerrerio Avraham Unterman Victoria Habet Carrie L. Lucas 《Immunity》2021,54(5):1083-1095.e7
- Download : Download high-res image (177KB)
- Download : Download full-size image
6.
Production and release of infectious hepatitis C virus from human liver cell cultures in the three-dimensional radial-flow bioreactor 总被引:5,自引:0,他引:5
Aizaki H Nagamori S Matsuda M Kawakami H Hashimoto O Ishiko H Kawada M Matsuura T Hasumura S Matsuura Y Suzuki T Miyamura T 《Virology》2003,314(1):16-25
Lack of efficient culture systems for hepatitis C virus (HCV) has been a major obstacle in HCV research. Human liver cells grown in a three-dimensional radial-flow bioreactor were successfully infected following inoculation with plasma from an HCV carrier. Subsequent detection of increased HCV RNA suggested viral replication. Furthermore, transfection of HCV RNA transcribed from full-length cDNA also resulted in the production and release of HCV virions into supernatant. Infectivity was shown by successful secondary passage to a new culture. Introduction of mutations in RNA helicase and polymerase regions of HCV cDNA abolished virus replication, indicating that reverse genetics of this system is possible. The ability to replicate and detect the extracellular release of HCV might provide clues with regard to the persistent nature of HCV infection. It will also accelerate research into the pathogenicity of HCV, as well as the development of prophylactic agents and new therapy. 相似文献
7.
K Yoshizaki H Nishikawa S Yamada T Morimoto H Watari 《The Japanese journal of physiology》1979,29(2):211-225
The 31P-NMR technique was used for the monitoring of intracellular pH and studying its heterogeneity in the femoral biceps muscle of Rana catesbiana under anaerobic conditions. The value of intracellular pH of fresh muscle calculated from the chemical shift of intracellular inorganic phosphate (P1) was 7.3 on average and the line width of P1 was about 0.2 ppm. As the line width determined by the relaxation mechanism was 0.099 ppm, the P1 signal in fresh muscle was concluded to consist of overlapped narrow components, which indicated the heterogeneity of muscular pH (about 0.2 pH unit). Living muscle showed gradual acidification due to glycolysis and the decrease in heterogeneity. When glycolysis was suppressed by iodoacetic acid, slight alkalization due to the breakdown of creatine phosphate was observed. When the Lohmann reaction was suppressed by 2, 4-dinitro-1-fluorobenzene, rapid acidification accompanied by the appearance of a new acidic component was observed with the onset of ATP decrease. This new component was not detected in the muscle pretreated with glycerol to disrupt the transverse tubules. Therefore, it is likely that this new acidic component originates in the intracellular compartment, and not in the cellular difference. 相似文献
8.
The topological changes of the human autonomic cardiac nervous system in two cadavers with a retroesophageal right subclavian
artery (Rersa) were compared with the normal autonomic cardiac nervous system. The following new results were obtained in
addition to the conventional deficient finding of the right recurrent laryngeal nerve. (1) Right superior cardiac nerves arising
from the superior cervical ganglion were consistently observed in both cadavers, in addition to the right thoracic cardiac
nerves along the Rersa. (2) A segmental accompanying tendency of the right cardiac nerves was recognized: the cardiac nerves
arising from the sympathetic trunk cranial to the middle cervical ganglia ran along with the right common carotid artery,
whereas the cardiac nerves arising from the sympathetic trunk caudal to the vertebral ganglion ran along the Rersa. (3) The
right thoracic cardiac nerves, which have never been observed to accompany the normal right subclavian artery, ran along the
proximal part of the Rersa. According to previous reports of individuals with the Rersa, a thick right thoracic cardiac nerve
is commonly observed instead of a right superior cardiac nerve. However, all the cardiac nerves were recognized in both the
individuals described in the present report. Therefore, we strongly disagree with the previous idea that the origin of the
right cardiac nerves from the sympathetic trunk and ganglia is shifted caudally in individuals with the Rersa. The topological
changes of the autonomic cardiac nervous system in two cases of Rersa also reflected spatial changes of great arteries. 相似文献
9.
Murata K Inami M Hasegawa A Kubo S Kimura M Yamashita M Hosokawa H Nagao T Suzuki K Hashimoto K Shinkai H Koseki H Taniguchi M Ziegler SF Nakayama T 《International immunology》2003,15(8):987-992
CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients. 相似文献
10.
Susumu Harada Maya Iijima Akiko Nakamura Yoshitsugu Yoshizaki Hiroaki Matsuo Eisin Morita 《Arerugī》2007,56(1):41-48
BACKGROUND: Either omega-5 gliadin or high molecular weight glutenin is known to be a major allergen in wheat-dependent exercise-induced anaphylaxis (WDEIA). It is generally considered that gluten specific IgE score is more reliable than that of wheat specific IgE score for the diagnosis of WDEIA. Our aim was to verify the significance of gluten specific IgE in the diagnosis of WDEIA. METHODS: We evaluated the result of gluten CAP-RAST score and omega-5 gliadin specific IgE score on four WDEIA patients who visited our hospital during the years 2004 and 2005, whose diagnosis were onfirmed by prick tests, immunoblot tests and provocation tests. RESULTS: Contrary to our expectations, all four patients showed negative gluten CAP-RAST scores, however all patient's omega-5 gliadin specific IgE scores were positive. CONCLUSION: Our results suggest that gluten specific CAP-RAST score is unreliable in the diagnosis of WDEIA. On the other hand omega-5 gliadin specific IgE score is possibly a better candidate as a diagnostic tool for WDEIA. 相似文献