全文获取类型
收费全文 | 2244篇 |
免费 | 98篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 69篇 |
妇产科学 | 31篇 |
基础医学 | 282篇 |
口腔科学 | 14篇 |
临床医学 | 161篇 |
内科学 | 551篇 |
皮肤病学 | 22篇 |
神经病学 | 135篇 |
特种医学 | 32篇 |
外科学 | 531篇 |
综合类 | 7篇 |
预防医学 | 51篇 |
眼科学 | 106篇 |
药学 | 122篇 |
中国医学 | 8篇 |
肿瘤学 | 216篇 |
出版年
2023年 | 11篇 |
2022年 | 30篇 |
2021年 | 55篇 |
2020年 | 42篇 |
2019年 | 45篇 |
2018年 | 40篇 |
2017年 | 33篇 |
2016年 | 31篇 |
2015年 | 53篇 |
2014年 | 41篇 |
2013年 | 92篇 |
2012年 | 119篇 |
2011年 | 134篇 |
2010年 | 73篇 |
2009年 | 51篇 |
2008年 | 100篇 |
2007年 | 109篇 |
2006年 | 103篇 |
2005年 | 104篇 |
2004年 | 104篇 |
2003年 | 111篇 |
2002年 | 155篇 |
2001年 | 49篇 |
2000年 | 71篇 |
1999年 | 56篇 |
1998年 | 32篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 16篇 |
1994年 | 14篇 |
1993年 | 18篇 |
1992年 | 46篇 |
1991年 | 53篇 |
1990年 | 37篇 |
1989年 | 33篇 |
1988年 | 43篇 |
1987年 | 39篇 |
1986年 | 24篇 |
1985年 | 24篇 |
1984年 | 8篇 |
1983年 | 23篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1974年 | 8篇 |
1973年 | 10篇 |
1970年 | 7篇 |
排序方式: 共有2356条查询结果,搜索用时 15 毫秒
1.
2.
Jun Agata Nobuyuki Ura Hideaki Yoshida Yasuyuki Shinshi Haruki Sasaki Masaya Hyakkoku Shinya Taniguchi Kazuaki Shimamoto 《Hypertension research》2006,29(11):865-874
Angiotensin II receptor blockers (ARBs) are widely used for the treatment of hypertension. It is believed that treatment with an ARB increases the level of plasma angiotensin II (Ang II) because of a lack of negative feedback on renin activity. However, Ichikawa (Hypertens Res 2001; 24: 641-646) reported that long-term treatment of hypertensive patients with olmesartan resulted in a reduction in plasma Ang II level, though the mechanism was not determined. It has been reported that angiotensin 1-7 (Ang-(1-7)) potentiates the effect of bradykinin and acts as an angiotensin-converting enzyme (ACE) inhibitor. It is known that ACE2, which was discovered as a novel ACE-related carboxypeptidase in 2000, hydrolyzes Ang I to Ang-(1-9) and also Ang II to Ang-(1-7). It has recently been reported that olmesartan increases plasma Ang-(1-7) through an increase in ACE2 expression in rats with myocardial infarction. We hypothesized that over-expression of ACE2 may be related to a reduction in Ang II level and the cardioprotective effect of olmesartan. Administration of 0.5 mg/kg/day of olmesartan for 4 weeks to 12-week-old stroke-prone spontaneously hypertensive rats (SHRSP) significantly reduced blood pressure and left ventricular weight compared to those in SHRSP given a vehicle. Co-administration of olmesartan and (D-Ala7)-Ang-(1-7), a selective Ang-(1-7) antagonist, partially inhibited the effect of olmesartan on blood pressure and left ventricular weight. Interestingly, co-administration of (D-Ala7)-Ang-(1-7) with olmesartan significantly increased the plasma Ang II level (453.2+/-113.8 pg/ml) compared to olmesartan alone (144.9+/-27.0 pg/ml, p<0.05). Moreover, olmesartan significantly increased the cardiac ACE2 expression level compared to that in Wistar Kyoto rats and SHRSP treated with a vehicle. Olmesartan significantly improved cardiovascular remodeling and cardiac nitrite/ nitrate content, but co-administration of olmesartan and (D-Ala7)-Ang-(1-7) partially reversed this anti-remodeling effect and the increase in nitrite/nitrate. These findings suggest that olmesartan may exhibit an ACE inhibitory action in addition to an Ang II receptor blocking action, prevent an increase in Ang II level, and protect cardiovascular remodeling through an increase in cardiac nitric oxide production and endogenous Ang-(1-7) via over-expression of ACE2. 相似文献
3.
Keishi Kashibuchi Kyoichi Tomita Jack A Schalken Haruki Kume Takumi Takeuchi Tadaichi Kitamura 《International journal of urology》2007,14(9):789-794
OBJECTIVES: To determine the value of the loss of expression of E-cadherin and cadherin associated molecules as useful markers for both prognosis and chemosensitivity in bladder cancer patients who have undergone radical cystectomy. PATIENTS AND METHODS: In 55 paraffin embedded specimens of radical cystectomy at our hospital from 1982 to 2000, the expression of E-cadherin, alpha-, beta- and gamma-catenin was examined by immunohistochemical staining. To evaluate the prognostic significance of these molecules, Kaplan-Meier survival curves were constructed and a statistical analysis was calculated by a log-rank test. A multivariate test (tumor stage, tumor grade, lymph node metastasis, configuration, the expression of E-cadherin, alpha-, beta- and gamma-catenin) was performed to detect prognostic markers. RESULTS: Normal expression was found in 33 cases (60.0%) for E-cadherin, 29 (52.7%) for alpha-catenin, 31 cases (56.4%) for beta-catenin, and 31 cases (56.4%) for gamma-catenin. The expression patterns for E-cadherin, alpha-, beta- and gamma-catenin were significantly correlated with each other (P < 0.01). Survival analysis showed a significant difference between normal and aberrant expression in each staining. A multivariate analysis revealed that the expression of alpha- catenin was an independent prognostic factor (P = 0.0191). In 23 patients that received adjuvant chemotherapy, there was a significant difference in survival between the normal and aberrant expression of alpha-catenin, but not other molecules. CONCLUSION: Alpha-catenin may not only be a good prognostic marker, but also one of key molecules that determine the chemosensitivities in patients with invasive bladder cancer. 相似文献
4.
Yoshiharu Kikawa Akio Nakai Yosuke Shigematsu Masakatsu Sudo Kimitaka Kato Shinichi Haruki 《Pediatric nephrology (Berlin, Germany)》1990,4(4):343-344
Leukotriene B4 (LTB4) production in polymorphonuclear leucocytes (PMN) was examined in ten children with steroid-responsive nephrotic syndrome (SRNS) before, during, and after steroid administration. Comparison of LTB4 production was made in 14 children with non-inflammatory disease who were not receiving steroid therapy. No significant change was noted in PMN LTB4 biosynthesis in children with SRNS throughout any phase of the disease. Furthermore, there was no significant difference in LTB4 biosynthesis in PMN between SRNS patients before steroid therapy and patients with non-inflammatory disease. These findings suggest that inhibition of LTB4 production is not involved in the mechanism underlying steroid action in SRNS. 相似文献
5.
Arg60 to Leu mutation of the human thromboxane A2 receptor in a dominantly inherited bleeding disorder. 总被引:7,自引:2,他引:5
下载免费PDF全文
![点击此处可从《The Journal of clinical investigation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
T Hirata A Kakizuka F Ushikubi I Fuse M Okuma S Narumiya 《The Journal of clinical investigation》1994,94(4):1662-1667
Recent advances in molecular genetics have revealed the mechanisms underlying a variety of inherited human disorders. Among them, mutations in G protein-coupled receptors have clearly demonstrated two types of abnormalities, namely loss of function and constitutive activation of the receptors. Thromboxane A2 (TXA2) receptor is a member of the family of G protein-coupled receptors and performs an essential role in hemostasis by interacting with TXA2 to induce platelet aggregation. Here we identify a single amino acid substitution (Arg60-->Leu) in the first cytoplasmic loop of the TXA2 receptor in a dominantly inherited bleeding disorder characterized by defective platelet response to TXA2. This mutation was found exclusively in affected members of two unrelated families with the disorder. The mutant receptor expressed in Chinese hamster ovary cells showed decreased agonist-induced second messenger formation despite its normal ligand binding affinities. These results suggest that the Arg60 to Leu mutation is responsible for the disorder. Moreover, dominant inheritance of the disorder suggests the possibility that the mutation produces a dominant negative TXA2 receptor. 相似文献
6.
A 33-year-old male presented to the Chiba University Hospital with the main complaint of right flank pain. Bilateral vas deferens were not palpable. Hormonal examination revealed hypergonadotropic hypogonadism and cytogenetic studies a 47,XXY karyotype. The significance of the association of this karyotype with the absence of vas deferens is discussed. 相似文献
7.
Haruo Ito Zengo Kataumi Shigeyuki Yanagi Kenji Kawamura Hidenori Sumiya Hideki Fuse Jun Shimazaki 《International journal of andrology》1986,9(3):161-169
Testicular development was studied in prepubertal boys with retractile testes. Testicular volume, the diameter of the seminiferous tubules and the number of spermatogonia in the tubules were decreased in cases of unilateral retractile testis, when compared with values for the contralateral normally descended testis. On the other hand, in patients with a unilateral retractile testis and contralateral inguinal testis, there was no difference in the developmental parameters between the two testes. These results suggest that the retractile testis has developmental failures characteristic of a cryptorchid testis and therefore requires orchiopexy. 相似文献
8.
Yuichi Yamada Teruhiko Kido Masao Ishizaki Ryumon Honda Ikiko Tsuritani Haruki Yamaya Kôji Nogawa 《International archives of occupational and environmental health》1988,60(1):7-14
Summary Forty-nine out of 54 male workers engaged in the production of an epoxy compound, t-methyl-3-phenylglycidate, showed skin symptoms in varing degrees that may be due to the skin-irritative effect of the compound. The exposed workers were also shown to have subjective symptoms which may be related to the irritative property of the compound on surface tissue. Laboratory examinations on the blood obtained from the exposed workers showed significantly higher values of leukocyte concentration as compared with the non-exposed controls. This was chiefly caused by the increase of neutrophilic granulocytes and T-cell lymphocytes. Serum IgA levels of the exposed workers were shown to be significantly lower than those of the control group. Hemoglobin concentration, hematocrit value and red cell count of the exposed workers remained at the same level as those of the control subjects. Liver or kidney damage was not found in biochemical analyses on the sera of exposed workers. 相似文献
9.
10.
Misawa Y Oki SI Tezuka Y Fuse K 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2001,47(5):563-564
Primary tissue failure of bioprosthetic heart valves refers primarily to calcification of the leaflets of the bioprosthesis. A 75 year old patient underwent reoperation 15 years after mitral valve replacement with a Carpentier-Edwards porcine bioprosthesis. The extracted bioprosthetic valve was found to have one prolapsed leaflet and a small amount of calcification on all three leaflets without tear or perforation. The two commissures suspending the prolapsed leaflet were detached, causing mitral valve regurgitation. 相似文献