全文获取类型
收费全文 | 5068篇 |
免费 | 285篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 50篇 |
妇产科学 | 107篇 |
基础医学 | 613篇 |
口腔科学 | 125篇 |
临床医学 | 251篇 |
内科学 | 1435篇 |
皮肤病学 | 148篇 |
神经病学 | 448篇 |
特种医学 | 107篇 |
外科学 | 1021篇 |
综合类 | 11篇 |
预防医学 | 110篇 |
眼科学 | 70篇 |
药学 | 338篇 |
中国医学 | 11篇 |
肿瘤学 | 461篇 |
出版年
2023年 | 52篇 |
2022年 | 88篇 |
2021年 | 121篇 |
2020年 | 85篇 |
2019年 | 128篇 |
2018年 | 147篇 |
2017年 | 105篇 |
2016年 | 133篇 |
2015年 | 108篇 |
2014年 | 181篇 |
2013年 | 190篇 |
2012年 | 331篇 |
2011年 | 323篇 |
2010年 | 169篇 |
2009年 | 157篇 |
2008年 | 264篇 |
2007年 | 286篇 |
2006年 | 268篇 |
2005年 | 301篇 |
2004年 | 260篇 |
2003年 | 235篇 |
2002年 | 219篇 |
2001年 | 100篇 |
2000年 | 101篇 |
1999年 | 107篇 |
1998年 | 65篇 |
1997年 | 54篇 |
1996年 | 38篇 |
1995年 | 26篇 |
1994年 | 43篇 |
1993年 | 28篇 |
1992年 | 51篇 |
1991年 | 56篇 |
1990年 | 36篇 |
1989年 | 61篇 |
1988年 | 57篇 |
1987年 | 57篇 |
1986年 | 38篇 |
1985年 | 40篇 |
1984年 | 32篇 |
1983年 | 31篇 |
1982年 | 13篇 |
1981年 | 14篇 |
1980年 | 13篇 |
1979年 | 33篇 |
1978年 | 17篇 |
1977年 | 16篇 |
1976年 | 15篇 |
1974年 | 23篇 |
1972年 | 16篇 |
排序方式: 共有5396条查询结果,搜索用时 15 毫秒
51.
Oral immunization with ATP-dependent protease-deficient mutants protects mice against subsequent oral challenge with virulent Salmonella enterica serovar typhimurium
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Matsui H Suzuki M Isshiki Y Kodama C Eguchi M Kikuchi Y Motokawa K Takaya A Tomoyasu T Yamamoto T 《Infection and immunity》2003,71(1):30-39
We evaluated the efficacy of mutants with a deletion of the stress response protease gene as candidates for live oral vaccine strains against Salmonella infection through infection studies with mice by using a Salmonella enterica serovar Typhimurium mutant with a disruption of the ClpXP or Lon protease. In vitro, the ClpXP protease regulates flagellum synthesis and the ClpXP-deficient mutant strain exhibits hyperflagellated bacterial cells (T. Tomoyasu et al., J. Bacteriol. 184:645-653, 2002). On the other hand, the Lon protease negatively regulates the efficacy of invading epithelial cells and the expression of invasion genes (A. Takaya et al., J. Bacteriol. 184:224-232, 2002). When 5-week-old BALB/c mice were orally administered 5 x 10(8) CFU of the ClpXP- or Lon-deficient strain, bacteria were detected with 10(3) to 10(4) CFU in the spleen, mesenteric lymph nodes, Peyer's patches, and cecum 1 week after inoculation and the bacteria then decreased gradually in each tissue. Significant increases of lipopolysaccharide-specific immunoglobulin G (IgG) and secretory IgA were detected at week 4 and maintained until at least week 12 after inoculation in serum and bile, respectively. Immunization with the ClpXP- or Lon-deficient strain protected mice against oral challenge with the serovar Typhimurium virulent strain. Both the challenged virulent and immunized avirulent salmonellae were completely cleared from the spleen, mesenteric lymph nodes, Peyer's patches, and even cecum 5 days after the challenge. These data indicate that Salmonella with a disruption of the ATP-dependent protease ClpXP or Lon can be useful in developing a live vaccine strain. 相似文献
52.
53.
Masaru Kishida Hiroki Nakazono Rei Kuroiwa Hidenori Dokai Junko Nakazato Hiroaki Nakamura Itsuo Suzuki Noriaki Shinomiya 《Arerugī》2007,56(11):1372-1377
BACKGROUND: Relationship between post administrative changes in plasma drug levels and bronchodilation remains unknown. In this study, we measured plasma levels of procaterol, a beta2-agonist, when being inhaled through nebulizers in children with bronchial asthma to examine relationship between improvement of pulmonary function and the plasma levels. METHOD: Six asthmatic children with the mean age of 9.8 years, inhaled 0.3 ml of 0.01% procaterol solution through a nebulizer. We examined changes in pulmonary function and plasma procaterol levels before and after inhalation. RESULTS: Procaterol was detected in the plasma 2 minutes after inhalation when it already rose to the maximum level, and kept the steady until showing a decline in 30 minutes. The measured highest value was 87.8+/-45.1 pg/ml. FEV 1.0 remarkably increased 2 minutes after inhalation and was maintained until 60 minutes after inhalation. Other lung function parameters also improved. There was no significant change in the heart rate, but serum potassium concentrations significantly dropped in all patients 60 minutes after inhalation. CONCLUSION: Plasma procaterol levels promptly rose to the peak at 2 minutes after inhalation and decreased 30 minutes later. Improvement of pulmonary function started promptly at minutes after inhalation and it became a peak 60 minutes later. 相似文献
54.
Yasuyuki Sumikawa Yuriko Ueki Akira Miyoshi Lei Cheng Min Yin Hai-Bo Shi Masuko Daitoku Sumikawa Takeshi Kono Toshiyuki Aoki Ichiro Katayama 《Arerugī》2007,56(10):1270-1275
BACKGROUND: The comparative studies of the prevalence of atopic dermatitis and skin barrier functions in Japanese and Chinese were performed. METHODS: Clinical investigations were performed in 68 elementary school students in Lhasa, Tibet Autonomous Region and 67 students in Yixing, Jiangsu Province in China, and 99 students in Nishinomiya, Hyogo in Japan. Transepidermal water loss (TEWL) and capacitance were measured. Questionary survey about bathing frequency was also performed for students in Lhasa, Yixing and Osaka. RESULT: The prevalence rate of atopic dermatitis was 0% in Lhasa, 2.63% in Yixing, 4.26% in Nishinomiya. TEWL of students in Nishinomiya was higher than that in Yixing and Lhasa. Capacitance of students in Lhasa was lower than that in Nishinomiya and Yixing. The frequency of taking a bath in Lhasa was about 2.2 times per month and fewer than that in Nishinomiya and Yixing. CONCLUSION: There was tendency that the prevalence of atopic dermatitis increased according to increase of TEWL. It was thought that more investigations are necessary whether the development of habitat and environment influence the prevalence of atopic dermatitis and skin barrier function. 相似文献
55.
Shinichiro Nanko Akira Ueki Mineko Hattori Xiao Y. Dai Tsukasa Sasaki Rimmei Fukuda Kazuhiko Ikeda Hajime Kazamatsuri 《American journal of medical genetics. Part A》1994,54(4):361-364
Parkinson's disease is thought to be caused by a combination of unknown environmental, genetic, and degenerative factors. Evidence from necropsy brain samples and pharmacokinetics suggests involvement of dopamine receptors in the pathogenesis or pathophysiology of Parkinson's disease. Genetic association studies between Parkinson's disease and dopamine D2, D3 and D4 receptor gene polymorphisms were conducted. The polymorphism was examined in 71 patients with Parkinson's disease and 90 controls. There were no significant differences between two groups in allele frequencies at the D2, D3, and D4 dopamine receptor loci. Our findings do not support the hypothesis that susceptibility to Parkinson's disease is associated with the dopamine receptor polymorphisms examined. © 1994 Wiley-Liss, Inc. 相似文献
56.
Toyota N Uzawa H Komiyama M Shimada Y 《Journal of muscle research and cell motility》1999,20(8):755-760
We examined the binding domains of cardiac and fast skeletal muscle troponin I (CTnI and FTnI, respectively) to myofibrils (MFs). Deletion mutants containing CTnI amino acid residues 1–79, 43–207 and 80–207 (CTnI-head, CTnI-tail-1 and CTnI-tail-2, respectively) and FTnI amino acid residues 1–54 and 55–182 (FTnI-head and FTnI-tail, respectively) were transiently expressed in cardiac and fast skeletal muscle cells. To monitor the intracellular localization of these exogenously introduced truncated TnIs, epitope tagging was used. CTnI-tail-1 was incorporated into cardiac MFs specifically, but CTnI-tail-2 was not assembled onto any MFs examined. This suggests that there is no potent actin filament-binding site in CTnI-tail-2. Since CTnI-tail-1 has an amino acid extension (CTnI residues 43–79) whose sequence is longer than that of CTnI-head-2; it appears that this sequence extension is important in binding to cardiac MFs. FTnI-tail, containing the inhibitory domain of actomyosin ATPase, showed intensive and specific incorporation into fast MFs. FTnI-tail was a homologous fragment of CTnI-tail-2, but the binding patterns of these two domains differed greatly from each other. It is possible that the absence of potent binding affinity of CTnI-tail-2 corresponding to the inhibitory domain of actomyosin ATPase is advantageous for continuous cardiac muscle contraction, since a potent inhibitory activity is a serious obstacle to cardiac muscle contraction. It can be assumed that distinctive binding ability of functional domains of TnI-tails reflect unique adaptations to muscles with different physiological properties. 相似文献
57.
Saruta J Tsukinoki K Sasaguri K Ishii H Yasuda M Osamura YR Watanabe Y Sato S 《Cells, tissues, organs》2005,180(4):237-244
Human saliva chromogranin A (CgA) is clinically promising as a psychological stress marker. However, expression of CgA is poorly understood in humans, although salivary gland localization of CgA in other mammals, such as rodents and horses, has been demonstrated. In the present study, we investigated the expression and localization of CgA in the human submandibular gland (HSG) using various methods. CgA was consistently localized in serous and ductal cells in HSG, as detected by immunohistochemistry and in situhybridization. Reactivity was stronger in serous cells than in ductal cells. In addition, strong immunoreactivity for CgA was observed in the saliva matrix of ductal cavities. Western blotting gave one significant immunoreactive band of 68 kDa in the adrenal gland, HSG and saliva. Finally, CgA was detected in secretory granules of serous and ductal cells by immunoelectron microscopy. In conclusion, CgA in humans is produced by HSG and secreted into saliva. 相似文献
58.
59.
Quantitative assessment of proximal tubule function in single nephrons of the rat kidney 总被引:7,自引:0,他引:7
B M Brenner T M Daugharty I F Ueki J L Troy 《The American journal of physiology》1971,220(6):2058-2067
60.
A. Ueki L. Rosén B. Andbjer U. B. Finnman U. Altamimi A. M. Janson M. Goldstein L. F. Agnati K. Fuxe 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1993,93(2):259-270
We studied the ability of the vigilance-promoting drug modafinil to modulate the anterograde and retrograde changes in tyrosine hydroxylase (TH) immunoreactivity and in dopamine (DA) stores in the nigro-neostriatal DA neurons, following a partial hemitransection of this ascending DA system, using a combined morphometrical, biochemical and behavioural analysis. Modafinil was given daily i.p. in doses of 10–100 mg/kg, starting 15 min after the lesion, and the partially hemitransected rats were killed 2 weeks later. Changes in TH-immunoreactive nerve cell bodies and nerve terminals induced by the partial hemitransection were studied in the substantia nigra and neostriatum in combination with image analysis. The substantia nigra and neostriatum were also subjected to biochemical analysis of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels. Modafinil treatment dose-dependently (10–100 mg/kg) counteracted the hemitransection-induced disappearance of nigral TH-immunoreactive nerve cell body profiles and neostriatal TH-immunoreactive nerve terminal profiles. A 2-week treatment with 100 mg/kg of modafinil also counteracted the hemitransection-induced depletion of DA stores in the neostriatum and the ventral midbrain. Moreover, the repeated daily treatment with modafinil (100 mg/kg) protected against the hemitransection-induced disappearance of striatal 5-hydroxytryptamine, 5-hydroxyindoleacetic acid and noradrenaline levels. Striatal DA function was analysed by studying apomorphine-induced (1 mg/kg, s.c.) ipsilateral rotational behaviour 4 and 11 days after the operation. A marked dose-dependent reduction of ipsilateral rotational behaviour was demonstrated after the daily modafinil treatment in the partially hemitransected rats. In another model involving unilateral nigral microinjections of 6-hydroxydopamine, acute (one single dose) modafinil (100 mg/kg) did not affect the contralateral rotational behaviour induced by apomorphine (0.05 mg/kg s.c.), when given 30 min before the apomorphine. Taken together, morphological, neurochemical and behavioural evidence has been obtained that anterograde and retrograde changes induced in the DA stores and TH immunoreactivity of the nigro-neostriatal DA neurons by a partial hemitransection are counteracted by modafinil in a dose dependent way with 100 mg/kg producing a significant protective action against impairment of DA transmission. The results of this study open up the possibility that modafinil may protect against the anterograde and retrograde degeneration of nigrostriatal DA neurons seen after mechanically induced injury. 相似文献