全文获取类型
收费全文 | 7472篇 |
免费 | 306篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 177篇 |
妇产科学 | 104篇 |
基础医学 | 1115篇 |
口腔科学 | 182篇 |
临床医学 | 369篇 |
内科学 | 2174篇 |
皮肤病学 | 140篇 |
神经病学 | 464篇 |
特种医学 | 261篇 |
外科学 | 1153篇 |
综合类 | 25篇 |
预防医学 | 176篇 |
眼科学 | 80篇 |
药学 | 463篇 |
中国医学 | 22篇 |
肿瘤学 | 826篇 |
出版年
2023年 | 24篇 |
2022年 | 47篇 |
2021年 | 113篇 |
2020年 | 80篇 |
2019年 | 113篇 |
2018年 | 109篇 |
2017年 | 102篇 |
2016年 | 125篇 |
2015年 | 117篇 |
2014年 | 195篇 |
2013年 | 279篇 |
2012年 | 460篇 |
2011年 | 498篇 |
2010年 | 270篇 |
2009年 | 233篇 |
2008年 | 466篇 |
2007年 | 531篇 |
2006年 | 575篇 |
2005年 | 566篇 |
2004年 | 510篇 |
2003年 | 472篇 |
2002年 | 471篇 |
2001年 | 76篇 |
2000年 | 66篇 |
1999年 | 81篇 |
1998年 | 154篇 |
1997年 | 106篇 |
1996年 | 93篇 |
1995年 | 73篇 |
1994年 | 66篇 |
1993年 | 73篇 |
1992年 | 51篇 |
1991年 | 58篇 |
1990年 | 48篇 |
1989年 | 46篇 |
1988年 | 37篇 |
1987年 | 37篇 |
1986年 | 21篇 |
1985年 | 28篇 |
1984年 | 25篇 |
1983年 | 19篇 |
1982年 | 25篇 |
1981年 | 32篇 |
1980年 | 36篇 |
1979年 | 15篇 |
1978年 | 18篇 |
1975年 | 19篇 |
1973年 | 16篇 |
1972年 | 13篇 |
1968年 | 15篇 |
排序方式: 共有7811条查询结果,搜索用时 359 毫秒
111.
Shin-ichiro Masunaga M.D. Ph.D. Koji Ono M.D. Ph.D. Yoshinori Sakurai D.Eng. Masao Takagaki M.D. Ph.D. Toru Kobayashi D.Eng. Minoru Suzuki M.D. Yuko Kinashi M.D. Ph.D. Mitsuhiko Akaboshi Ph.D. 《International journal of radiation oncology, biology, physics》1998,41(5):365
Purpose: Response of quiescent (Q) and total tumor cells in solid tumors to neutron irradiation with three different cadmium (Cd) ratios was examined. The role of Q cells in tumor control was also discussed.Methods and Materials: C3H/He mice bearing SCC VII tumors received continuous administration of 5-bromo-2′-deoxyuridine (BrdU) for 5 days using implanted mini-osmotic pumps to label all proliferating (P) cells. Thirty minutes after intraperitoneal injection of sodium borocaptate-10B (BSH), or 3 h after oral administration of dl-p-boronophenylalanine-10B (BPA), the tumors were irradiated with neutrons, or those without 10B-compounds were irradiated with gamma rays. This neutron irradiation was performed using neutrons with three different cadmium (Cd) ratios. The tumors were then excised, minced, and trypsinized. The tumor cell suspensions were incubated with cytochalasin-B (a cytokinesis-blocker), and the micronucleus (MN) frequency in cells without BrdU labeling (Q cells) was determined using immunofluorescence staining for BrdU. The MN frequency in total (P + Q) tumor cells was determined from tumors that were not pretreated with BrdU. The sensitivity to neutrons was evaluated in terms of the frequency of induced micronuclei in binuclear tumor cells (MN frequency).Results: Without 10B-compounds, the MN frequency in Q cells was lower than that in the total cell population. The sensitivity difference between total and Q cells was reduced by neutron irradiation. Relative biological effectiveness (RBE) of neutrons compared with gamma rays was larger in Q cells than in total cells, and the RBE values for low-Cd-ratio neutrons tended to be larger than those for high-Cd-ratio neutrons. With 10B-compounds, MN frequency for each cell population was increased, especially for total cells. This increase in MN frequency was marked when high-Cd-ratio neutrons were used. BPA increased the MN frequency for total tumor cells more than BSH. Nevertheless, the sensitivity of Q cells treated with BPA was lower than that in BSH-treated Q cells. This tendency was clearly observed in high-Cd-ratio neutrons.Conclusion: From the viewpoint of enhancing the Q-cell sensitivity, tumors should be irradiated with high-Cd-ratio neutrons after BSH administration. However, normal tissue reaction remains to be examined because of its low tumor-to-normal tissue and tumor-to-blood biodistribution ratios. 相似文献
112.
Expression of apoptosis-related proteins in adenomyotic uteri treated with danazol and GnRH agonists. 总被引:2,自引:0,他引:2
Ken Ueki Koji Kumagai Hidetoshi Yamashita Zhong-lian Li Minoru Ueki Yoshinori Otsuki 《International journal of gynecological pathology》2004,23(3):248-258
The biologic properties of adenomyosis and the effects of therapeutic agents on adenomyosis were evaluated with immunohistochemistry, terminal deoxy-nucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method, transmission electron microscopy, and analysis of genomic abnormality. In the adenomyotic endometrium, estrogen receptor (ER) expression was more intense than in the eutopic endometrium during the secretory phase, and bcl-2 was constantly expressed throughout the menstrual cycle. The expression of ER and bcl-2 was weaker in the adenomyotic endometrium treated with danazol than in that treated with gonadotro-pin-releasing hormone agonist (GnRHa), whereas bcl-2 phosphorylated on serine-87 was more intensely expressed in danazol-treated adenomyotic endometrium than in the GnRHa-treated one. The number of TUNEL-positive cells increased in the adenomyotic endometrium treated with danazol or GnRHa. Ultrastructurally, most of the adenomyotic endometrial cells treated with danazol underwent postapoptotic necrosis and formed a cluster of dead cells. In contrast, cells treated with GnRHa underwent typical apoptosis and were sparsely distributed in the adenomyotic endometrium. Analysis of several cancer-related genes showed no microsatellite instability or loss of heterozygosity in adenomyotic tissues. Therefore, we conclude that the occurrence of adenomyosis is correlated to bcl-2 expression regulated by estrogen and ER rather than genetic mutation. 相似文献
113.
Naruse H Arii T Kondo T Ohnishi M Sakaki T Takahashi K Masai M Ohyanagi M Iwasaki T Fukuchi M 《Annals of nuclear medicine》2000,14(6):427-432
It is likely that a close association exists between findings obtained by two methods: dobutamine stress echocardiography and 123I-MIBG scintigraphy. Both of these methods are associated with beta-adrenergic receptor mechanisms. This study was conducted to demonstrate the relation between myocardial response to dobutamine stress and sympathetic nerve release of norepinephrine in the failing heart. In 12 patients with heart failure due to idiopathic dilated cardiomyopathy, the myocardial effects of dobutamine stress were evaluated by low-dose dobutamine stress echocardiography: and sympathetic nerve function was evaluated by scintigraphic imaging with iodine-123 [123I] meta-iodobenzylguanidine (MIBG), an analogue of norepinephrine. Echocardiography provided quantitative assessment of wall motion and left ventricular dilation; radiotracer studies with 123I-MIBG provided quantitative assessment of the heart-to-mediastinum (H/M) uptake ratio and washout rate. Results showed that H/M correlated with baseline wall motion (r = 0.682, p = 0.0146), wall motion after dobutamine stress (r = 0.758, p = 0.0043), the change in wall motion (r = 0.667, p = 0.0178), and with left ventricular diastolic diameter (r = 0.837, p = 0.0007). In addition, the 123I-MIBG washout rate correlated with baseline wall motion (r = 0.608, p = 0.0360), wall motion after dobutamine stress (r = 0.703, p = 0.0107), and with the change in wall motion (r = 0.664, p = 0.0185). Wall motion, especially in the myocardial response to dobutamine stress, is related to sympathetic nerve activity in heart failure. 相似文献
114.
Akemi Irie Akira Yamauchi Keiichi Kontani Minoru Kihara Dage Liu Yukako Shirato Masako Seki Nozomu Nishi Takanori Nakamura Hiroyasu Yokomise Mitsuomi Hirashima 《Clinical cancer research》2005,11(8):2962-2968
PURPOSE: Galectin-9, a member of the beta-galactoside-binding galectin family, induces aggregation of certain cell types. We assessed the contribution of galectin-9 to the aggregation of breast cancer cells as well as the relation between galectin-9 expression in tumor tissue and distant metastasis in patients with breast cancer. EXPERIMENTAL DESIGN: Subclones of MCF-7 breast cancer cells with high or low levels of galectin-9 expression were established and either cultured on plastic dishes or transplanted into nude mice. The tumors of 84 patients with breast cancer were tested for galectin-9 expression by immunohistochemistry. The patients were followed up for 14 years. RESULTS: MCF-7 subclones with a high level of galectin-9 expression formed tight clusters during proliferation in vitro, whereas a subclone (K10) with the lowest level of galectin-9 expression did not. However, K10 cells stably transfected with a galectin-9 expression vector aggregated in culture and in nude mice. Ectopic expression of galectin-9 also reduced MCF-7 cell adhesion to extracellular matrix proteins. Tumors of 42 of the 84 patients were galectin-9 positive, and those of 19 of the 21 patients with distant metastasis were galectin-9 negative. None of the 13 patients with galectin-9-positive tumors and lymph node metastasis up to level II manifested distant metastasis. The cumulative disease-free survival ratio for galectin-9-positive patients was more favorable than that for the galectin-9-negative group (P < 0.0001). Multivariate analysis revealed that galectin-9 status influenced distant metastasis independently of and to a greater extent than lymph node metastasis. CONCLUSIONS: Galectin-9 is a possible prognostic factor with antimetastatic potential in breast cancer. 相似文献
115.
BackgroundAmong the gramineae species, orchard grass is a typical causative pollen that provokes seasonal rhinitis. The purpose of this study was to examine the protective efficacy of epinastine hydrochloride for signs and symptoms caused by repeated nasal provocation with discs containing orchard grass pollen.MethodsA single-dose, placebo-controlled, double-blind, crossover clinical study was conducted in subjects with orchard grass pollinosis. The pollen challenge was conducted with the use of provocation discs containing orchard grass pollen.ResultsEpinastine hydrochloride suppressed nasal symptoms caused by nasal provocation tests using orchard grass pollen discs. Among the nasal symptoms, the number of sneezing was significantly inhibited 30 minutes and 60 minutes after the administration of epinastine hydrochloride, as compared with placebo. There were no adverse reactions to the study drugs.ConclusionsOur results suggest that nasal provocation tests with discs containing orchard grass pollen is a useful method for evaluating the onset of action of antiallergic drugs. As compared with placebo, epinastine hydrochloride decreased early-phase sneezing and the total nasal symptom score after repeated nasal provocations with orchard grass pollen discs. 相似文献
116.
Ryota Tochinai Minoru Ando Tomo Suzuki Katsuya Suzuki Yuriko Nagata Chie Hata Kazumi Uchida Toshihide Kobayashi Shoichi Kado Kimiyuki Kaneko 《Experimental and toxicologic pathology》2013,65(6):737-743
Microtubule disassembling agents (MDAs) such as colchicine (COL) and vincristine sulfate (VCR) are known to be cardiotoxic. However, few attempts have been made to histopathologically examine cardiac lesions induced by MDAs. In this study, we endeavored to induce myocardial injury in rats by administering MDAs and to clarify the morphological features of these myocardial lesions. Male rats were intravenously administered COL (1.00 or 1.25 mg/kg for 2 days at single daily doses) or VCR (0.50 or 0.75 mg/kg for 2 days at single daily doses). The day after administration, hearts were excised and examined histopathologically, immunohistochemically and electron microscopically. Degeneration and necrosis of myocardial cells with vacuolation were observed in rats administered COL at 1.25 mg/kg or VCR at 0.75 mg/kg. Electron microscopic examination revealed vacuoles in swollen mitochondria. Moreover, there were cells showing pyknosis and karyorrhexis in the interstitium. TUNEL and immunohistochemical staining for endothelial cells and electron microscopic examination identified the apoptotic cells in the interstitium to be vascular endothelial cells. These vascular endothelial lesions were induced by lower doses of MDAs than were myocardial lesions. Furthermore, common sites of cardiac lesions induced by MDAs had almost the same distribution as areas positive for pimonidazole, a marker of hypoxia. These findings indicate that MDAs occasionally damage mitochondria in myocardial cells, and suggest that these changes involve microcirculatory dysfunction induced by endothelial cell injury. 相似文献
117.
Kazumichi Kawakubo Hiroyuki Isayama Yousuke Nakai Naoki Sasahira Hirofumi Kogure Takashi Sasaki Kenji Hirano Minoru Tada Kazuhiko Koike 《Gut and liver》2012,6(3):399-402
Patients with pancreatic cancer frequently suffer from both biliary and duodenal obstruction. For such patients, both biliary and duodenal self-expandable metal stent placement is necessary to palliate their symptoms, but it was difficult to cross two metal stents. Recently, endoscopic ultrasonography-guided choledochoduodenostomy (EUS-CDS) was reported to be effective for patients with an inaccessible papilla. We report two cases of pancreatic cancer with both biliary and duodenal obstructions treated successfully with simultaneous duodenal metal stent placement and EUS-CDS. The first case was a 74-year-old man with pancreatic cancer. Duodenoscopy revealed that papilla had been invaded with tumor and duodenography showed severe stenosis in the horizontal portion. After a duodenal uncovered metal stent was placed across the duodenal stricture, EUS-CDS was performed. The second case was a 63-year-old man who previously had a covered metal stent placed for malignant biliary obstruction. After removing the previously placed metal stent, EUS-CDS was performed. Then, a duodenal covered metal stent was placed across the duodenal stenosis. Both patients could tolerate a regular diet and did not suffer from stent occlusion. EUS-CDS combined with duodenal metal stent placement may be an ideal treatment strategy in patients with pancreatic cancer with both duodenal and biliary malignant obstruction. 相似文献
118.
Histological analysis of vasculopathy associated with pulmonary hypertension in combined pulmonary fibrosis and emphysema: comparison with idiopathic pulmonary fibrosis or emphysema alone 下载免费PDF全文
119.
120.
Mika Shigeta Minoru Saiki Daisuke Tsuruta Chika Ohata Norito Ishii Fumitake Ono Takahiro Hamada Teruki Dainichi Minao Furumura John J. Zone Sarolta Karpati Cassian Sitaru Takashi Hashimoto 《The Journal of dermatology》2012,39(12):1002-1005
Dermatitis herpetiformis (DH) is common in some Caucasian populations but extremely rare in Japanese, probably because of different immunogenetic backgrounds. We report two Japanese DH cases with typical clinical, histological and direct immunofluorescence features. However, no symptom of gluten‐sensitive enteropathy was shown. The diagnosis was confirmed by eliminating other autoimmune blistering diseases by indirect immunofluorescence, enzyme‐linked immunosorbent assays and immunoblotting. However, circulating immunoglobulin (Ig)A anti‐endomysium, reticulin and gliadin antibodies were not detected. IgA antibodies to tissue and epidermal transglutaminases were also negative. One case was associated with lung cancer and the other one with autoimmune pancreatitis. On review of 17 cases of DH reported in Japan over the previous 10 years, including our cases, one case was associated with gluten‐sensitive enteropathy, four with malignant neoplasms, two with autoimmune systemic disorders and one with psoriasis. Although our cases were typical of DH in clinical, histopathological and IgA deposit features, they showed different human leukocyte antigen haplotypes, no gluten‐sensitive enteropathy and no DH‐specific IgA antibodies, including those to epidermal and tissue transglutaminases. These results suggest that studies of unique characteristics in Japanese DH patients should facilitate further understanding of pathogenesis in DH. 相似文献