全文获取类型
收费全文 | 7887篇 |
免费 | 318篇 |
国内免费 | 62篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 161篇 |
妇产科学 | 39篇 |
基础医学 | 1046篇 |
口腔科学 | 153篇 |
临床医学 | 379篇 |
内科学 | 2435篇 |
皮肤病学 | 54篇 |
神经病学 | 478篇 |
特种医学 | 280篇 |
外科学 | 1204篇 |
综合类 | 38篇 |
预防医学 | 205篇 |
眼科学 | 86篇 |
药学 | 547篇 |
中国医学 | 64篇 |
肿瘤学 | 1048篇 |
出版年
2023年 | 34篇 |
2022年 | 60篇 |
2021年 | 121篇 |
2020年 | 67篇 |
2019年 | 82篇 |
2018年 | 108篇 |
2017年 | 77篇 |
2016年 | 110篇 |
2015年 | 123篇 |
2014年 | 174篇 |
2013年 | 231篇 |
2012年 | 388篇 |
2011年 | 452篇 |
2010年 | 242篇 |
2009年 | 252篇 |
2008年 | 450篇 |
2007年 | 484篇 |
2006年 | 511篇 |
2005年 | 559篇 |
2004年 | 548篇 |
2003年 | 542篇 |
2002年 | 581篇 |
2001年 | 111篇 |
2000年 | 109篇 |
1999年 | 122篇 |
1998年 | 188篇 |
1997年 | 145篇 |
1996年 | 119篇 |
1995年 | 108篇 |
1994年 | 111篇 |
1993年 | 114篇 |
1992年 | 96篇 |
1991年 | 75篇 |
1990年 | 95篇 |
1989年 | 67篇 |
1988年 | 52篇 |
1987年 | 66篇 |
1986年 | 59篇 |
1985年 | 42篇 |
1984年 | 30篇 |
1983年 | 32篇 |
1982年 | 41篇 |
1981年 | 42篇 |
1980年 | 34篇 |
1979年 | 19篇 |
1978年 | 23篇 |
1977年 | 15篇 |
1976年 | 16篇 |
1973年 | 17篇 |
1970年 | 13篇 |
排序方式: 共有8267条查询结果,搜索用时 15 毫秒
131.
Manometric Evidence of Improved Early Gastric Stasis by Erythromycin after Pylorus-preserving Pancreatoduodenectomy 总被引:3,自引:0,他引:3
Matsunaga H Tanaka M Takahata S Ogawa Y Naritomi G Yokohata K Yamaguchi K Chijiiwa K 《World journal of surgery》2000,24(10):1236-1242
Gastric stasis is a frequent complication of pylorus-preserving pancreatoduodenectomy (PPPD). We demonstrated that it might be attributable to delayed recovery of phase III activity of the gastric migrating motor complex due to low concentrations of plasma motilin caused by resection of the duodenum. Leucine 13-motilin is effective for treating gastric stasis, but it is not yet available for clinical use. Whether erythromycin would improve early gastric stasis after PPPD was tested clinically and by manometry. A manometric tube assembly and a gastrostomy tube were inserted in the stomach of 10 patients at PPPD for pressure recording from the gastric antrum and jejunum and for gastric juice drainage, respectively. After baseline recording, erythromycin 5 mg/kg was given intravenously on day 14 and saline as a placebo on day 17 every 4 hours four times a day. The daily volume of gastric juice output and the gastric motility index were measured. The mean period until the return of gastric phase III was 31 +/- 1 days. Erythromycin significantly increased the gastric motility index from 7.9 +/- 1.3 mmHg to 15.7 +/- 1.8 mmHg (p = 0.0005), whereas saline did not (7.2 +/- 1.6 mmHg to 6.5 +/- 1.2 mmHg; p = 0.21). Erythromycin significantly decreased the gastric juice output from 1,080 +/- 190 ml to 738 +/- 199 ml (p < 0.0001), but the saline injections did not (1,064 +/- 174 ml to 1,115 +/- 189 ml; p = 0.35). Erythromycin, a universally available motilin agonist, is a safe, effective, potent drug for the treatment of early gastric stasis after PPPD. 相似文献
132.
133.
The human T-cell factor-4 gene splicing isoforms, Wnt signal pathway, and apoptosis in renal cell carcinoma. 总被引:4,自引:0,他引:4
134.
135.
Seiji Kawakita Ryuichi Aibara Yuji Kawamura Eiji Yumoto Junzo Desaki 《The Laryngoscope》1998,108(3):398-402
The authors investigated the process of denervation and reinnervation of the interarytenoid (IA) muscle in the guinea pig using transmission electron microscopy and glycogen depletion technique after unilateral transection of the recurrent laryngeal nerve (RLN) and superior laryngeal nerve to clarify the innervation pattern of the unpaired IA muscle. Anastomosis between the bilateral arytenoid branches was confirmed in the belly of the IA muscle. Five weeks after transection, all of the IA muscle fibers appeared to have been reinnervated by the contralateral RLN. As the arytenoid branch of the RLN runs together with that of the contralateral RLN in a single intramuscular nerve funiculus, it is possible that collateral sprouting branches grow and extend into the adjacent denervated Schwann's sheaths. The authors conclude that the unpaired IA muscle, as a whole, receives specific motor nerve supply from the bilateral RLNs, although each muscle fiber is innervated unilaterally. 相似文献
136.
The 1.5 GHz Electromagnetic Near-field Used for Cellular Phones Does Not Promote Rat Liver Carcinogenesis in a Medium-term Liver Bioassay 总被引:3,自引:1,他引:3
Katsumi Imaida Masao Taki So-ichi Watanabe Yoshitsugu Kamimura Takayasu Ito Tsuyoshi Yamaguchi Nobuyuki Ito Tomoyuki Shirai 《Cancer science》1998,89(10):995-1002
We have recently established that local exposure to a 929.2 MHz electromagnetic near-field, used for cellular phones, does not promote rat liver carcinogenesis in a medium-term bioassay system. In the present study, a 1.439 GHz electromagnetic near-field (EMF), another microwave band employed for cellular phones in Japan, was similarly investigated. Time division multiple access (TDMA) signals for the Personal Digital Cellular (PDC) Japanese cellular telephone standard system were directed to rats through a quarter-wavelength monopole antenna. Numerical dosimetry showed that the peak SARs within the liver were 1.91–0.937 W/kg, while the whole-body average specific absorption rates (SARs) were 0.680–0.453 W/kg, when the time-averaged antenna radiation power was 0.33 W. Exposure was for 90 min a day, 5 days a week, over 6 weeks, to male F344 rats given a single dose of diethylnitrosamine (200 mg/kg, i.p.) 2 weeks previously. At week 3, all rats were subjected to a two-thirds partial hepatectomy. At week 8, the experiment was terminated and the animals were killed. Carcinogenic potential was scored by comparing the numbers and areas of the induced glutathione S-transferase placental form (GST-P)-positive foci in the livers of exposed (48) and sham-exposed rats (48). Despite increased serum levels of corticosterone, adrenocorticotropic hormone (ACTH) and melatonin, the numbers and the areas of GST-P-positive foci were not significantly altered by the exposure. These findings clearly indicated that local body exposure to a 1.439 GHz EMF, as in the case of a 929.2 MHz field, has no promoting effect on rat liver carcinogenesis in the present model. 相似文献
137.
Nobukazu Fujimoto Yoshihiko Segewa Nagio Takigawa Ichiro Takata Katsuyuki Hotta Hiroshi Mogami Masao Nakata Koichi Mandai Kenji Eguchi 《Lung cancer (Amsterdam, Netherlands)》1998,20(3):203-209
We present two cases of intrapulmonary lymph node. The patients were a 44-year-old woman and a 71-year-old man each with a small peripheral nodule in the lung. On computed tomography (CT) scans, both nodules were spiculated. Since histological diagnosis could not be obtained by bronchoscopic examination or CT-guided needle biopsy, they underwent video-assisted thoracoscopic surgery. Histological examination of the resected material revealed that both nodules were composed of lymph node. Intrapulmonary lymph node has until recently been assigned no clinical significance; however, differential diagnosis of this lesion from lung cancers and other metastatic tumors is now clinically important. 相似文献
138.
Kazushige Kiguchi Masao Iwamori Yukari Mochizuki Takeshi Kishikawa Katsumi Tsukazaki Masahiko Saga Akira Amemiya Shiro Nozawa 《Cancer science》1998,89(9):923-932
Cells of the human tumor cell line RMG-1, derived from a clear-cell adenocarcinoma of the ovary, were injected intraperitoneally into nude mice, and the cells obtained from the tumor nodules in the mesenterium were found to form a larger number of, and larger-sized, tumor nodules than the original RMG-1 cells. The RMG-1-h cells, transferred into culture from the tumor nodules after a 4th in vivo passage, showed a dissemination potential as high as that of cells disseminating directly from the tissues, and exceedingly higher than that of RMG-1 cells. To assess the molecular bases of the different biological properties of RMG-1 and RMG-1-h cells, we compared the content and expression of various carbohydrate antigens in both cells. The chromosomal profile of RMG-1-h cells revealed their human origin and was identical to that of the original RMG-1 cells. In contrast to the broad histogram for the Lex-bearing cells among RMG-1 cells in flow cytometry, the weakly and moderately positive cells toward anti-Lex antibody were found to be eliminated from the histogram for the RMG-1-h cells, resulting in the enrichment of cells strongly expressing Lex, which may account for the high dissemination potential. In addition, the adhesion of RMG-1 cells to mesothelial cells was found to be significantly inhibited by pretreatment of the cells with anti-Lex antibody, indicating Lex-mediated cell-to-cell interaction between ovarian cancer cells and mesothelial cells. By TLC-immunostaining, two Lex-glycolipids, III3Fucα-nLc4Cer and V3Fucα-nLc6Cer were detected in both RMG-1 and RMG-1-h cells, and their total concentrations were not significantly different from each other. However, the hydrophobic moieties of Lex-glycolipids in RMG-1-h cells were different from those in RMG-1 cells, suggesting that a difference in the structure of the hydrophobic moieties of Lex is partly involved in the enhanced reactivity of RMG-1-h cells toward anti-Lex antibody. Thus, the high dissemination potential of ovarian cancer cells was shown to be mediated by the Lex-determinant and the Lex-bearing cells are enriched by repeated in vivo passage of the cells into nude mice. 相似文献
139.
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
140.
从何首乌(PolygonummultiflorumThunb.)的根中分离出11个化合物,根据光谱学分析分别鉴定为:大黄酚(chrysophanol,Ⅰ)、大黄素甲醚(physcione,Ⅱ)、大黄素(emodin,Ⅲ)、ω-羟基大黄素(citreorosein,Ⅳ)、大黄酚8-O-β-D-吡喃葡萄糖苷(chrysophanol8-O-β-D-glucopyranoside,Ⅴ)、大黄素甲醚8-O-β-D-吡喃葡萄糖苷(Physcione8-O-β-D-glucopyranoside,Ⅵ)、大黄素8-O-β-D-吡喃葡萄糖苷(emodin8-O-β-D-glucopyranoside,Ⅶ)、决明酮8-O-β-D-吡喃葡萄糖苷(torachrysone8-O-β-D-glucopyranoside,Ⅷ)、2,3,5,4′-四羟基芪2-O-β-D-吡喃葡萄糖苷(2,3,5,4′-tetrahydroxystilbene2-O-β-D-glucopyranoside,Ⅸ)、没食子酸甲基酯(methylgallate,Ⅹ)和吲哚-3-(L-α-氨基-α-羟基内酸)甲酯[Indole-3-(L-α-amino-α-hydroxypropionicacid)methylester]。其中,化合物Ⅺ为新的天然产物。上述蒽醌和萘类化合物以及芦荟大黄素(aloe-emodin,Ⅻ)、大黄酸(rhein,)、芦荟大黄素8-O-β-D-吡喃葡萄糖苷(aloe-emodin8-O-β-D-glucopyranoside,)、大黄酚8-O-β-D-(6′-O-丙酰基)吡喃葡萄糖苷(chrysophanol8-O-β-D-(6′-O-malonyl)glucopyra- 相似文献