全文获取类型
收费全文 | 11762篇 |
免费 | 586篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 174篇 |
妇产科学 | 115篇 |
基础医学 | 1574篇 |
口腔科学 | 373篇 |
临床医学 | 701篇 |
内科学 | 3034篇 |
皮肤病学 | 267篇 |
神经病学 | 860篇 |
特种医学 | 460篇 |
外科学 | 2079篇 |
综合类 | 69篇 |
一般理论 | 1篇 |
预防医学 | 265篇 |
眼科学 | 107篇 |
药学 | 716篇 |
中国医学 | 26篇 |
肿瘤学 | 1480篇 |
出版年
2023年 | 96篇 |
2022年 | 162篇 |
2021年 | 332篇 |
2020年 | 154篇 |
2019年 | 249篇 |
2018年 | 296篇 |
2017年 | 230篇 |
2016年 | 303篇 |
2015年 | 298篇 |
2014年 | 398篇 |
2013年 | 440篇 |
2012年 | 681篇 |
2011年 | 759篇 |
2010年 | 431篇 |
2009年 | 409篇 |
2008年 | 620篇 |
2007年 | 710篇 |
2006年 | 656篇 |
2005年 | 679篇 |
2004年 | 619篇 |
2003年 | 575篇 |
2002年 | 584篇 |
2001年 | 197篇 |
2000年 | 189篇 |
1999年 | 204篇 |
1998年 | 147篇 |
1997年 | 146篇 |
1996年 | 103篇 |
1995年 | 107篇 |
1994年 | 61篇 |
1993年 | 75篇 |
1992年 | 156篇 |
1991年 | 137篇 |
1990年 | 156篇 |
1989年 | 105篇 |
1988年 | 106篇 |
1987年 | 124篇 |
1986年 | 119篇 |
1985年 | 98篇 |
1984年 | 52篇 |
1983年 | 60篇 |
1982年 | 24篇 |
1981年 | 28篇 |
1979年 | 55篇 |
1978年 | 29篇 |
1977年 | 23篇 |
1975年 | 22篇 |
1974年 | 24篇 |
1973年 | 23篇 |
1972年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Atsushi Takai Yoshihiro Okabe Nobuhiro Aoki Mariko Takada Shuji Yamamoto Naoya Kimoto Mikio Fujita Akihiko Okada Chiharu Kawanami Yukinobu Takimoto Akio Orino 《Nihon Shokakibyo Gakkai zasshi》2007,104(10):1498-1503
A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication. 相似文献
22.
Yumiko Motoi Masashi Takanashi Masako Itaya Kazuhiko Ikeda Yoshikuni Mizuno Hideo Mori 《Neuropathology》2004,24(1):60-65
In the present case, a patient in whom limb apraxia and asymmetrical parkinsonism developed suggesting corticobasal degeneration, is reported. Neuropathologic examination revealed numerous tufted astrocytes in the precentral cortex in addition to the characteristic pathologic findings of PSP. Therefore, on the basis of clinicopathologic features, atypical progressive supranuclear palsy was diagnosed. In addition, the brain tissue of the present patient was investigated with an antibody specific for four‐repeat tau (4R‐tau). In the precentral cortex, numerous tau‐positive tufted astrocytes, pretangles, and threads were positive for 4R‐tau. Using a confocal microscopy we demonstrated that tufted astrocytes positive for 4R‐tau were adjacent to astrocytes positive for GFAP. The present findings suggest that accumulation of four‐repeat tau in astrocytes is a degenerative process rather than a reactive process. 相似文献
23.
High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel 总被引:2,自引:0,他引:2
Kazuyoshi Takeshita Haruaki Ishibashi Masayuki Suzuki Takumi Yamamoto Toshihiro Akaike Masashi Kodama 《Artificial organs》1995,19(2):191-193
Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 107 cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit. 相似文献
24.
T Sekiya T Iwabuchi S Okabe M Takiguchi N Oda 《No shinkei geka. Neurological surgery》1990,18(11):1029-1033
In order to preserve the frontotemporal branch of the facial nerve in frontotemporal and trans-zygomatic craniotomies, electromyographic responses from the facial muscles were recorded preoperatively. Incising the frontotemporal branch of the facial nerve could be avoided by identifying the crossing point of the frontotemporal branch of the facial nerve on the superior border of the zygomatic arch. The crossing points were investigated in 20 patients and in most cases they existed between 2 cm and 6 cm from the anterior border of the external auditory canal. Another important point to preserve the facial nerve is to conserve the layer in which the facial nerve is included. Therefore, the surgical anatomy in the region of the zygomatic arch and temporal area was reviewed in detail. This knowledge is crucial for neurosurgeons to dissect precisely in this region without causing postoperative facial palsy. 相似文献
25.
26.
Toshifumi Gabata Masumi Kadoya Osamu Matsui Masashi Yamashiro Tsutomu Takashima Donald G. Mitchell Yasutaka Nakamura Kazuo Takeuchi Yasuni Nakanuma 《Journal of magnetic resonance imaging : JMRI》1998,8(2):503-504
We reported a case of the biliary cystadenoma of the liver. The cystic mass had labulation and septation and showed marked hyperintensity on T1-weighted images and hypointensity on T2-weighted images; MR findings were very unusual for cystadenoma. The content of the cystic mass was jelly-like, thick mucinous fluid without intracystic hemorrhage. We concluded that these unusual signal intensities of the cyst were due to hyperproteinous mucinous fluid. 相似文献
27.
Eye infections caused by adenovirus (Ad) often result in nosocomial infections and community epidemics with significant rates of morbidity. No antiviral agent effective against Ad is yet available for clinical use. Therefore, early diagnosis is still the mainstay for patient management and the prevention of epidemics. A multiplex PCR assay based on amplification of a combination of the fiber and hexon genes which can identify the six important oculopathogenic serotypes of Ads (Ad serotype 3[Ad3], Ad4, Ad7, Ad8, Ad19, and Ad37) in a single-tube amplification reaction was developed. Ad serotypes could be distinguished by the different amplicon sizes. The assay correctly identified prototype strains as well as isolates in clinical specimens. In comparison with a previously described PCR-restriction fragment polymorphism method, our assay gave unequivocal results for clinical specimens. Our multiplex PCR has the potential to serve as a rapid and cost-effective tool for the typing of important ocular Ads. 相似文献
28.
Hirota M Nozawa F Okabe A Shibata M Kuwata K Ogawa M 《Rinsho byori. The Japanese journal of clinical pathology》2000,48(6):527-532
Relationship between SIRS and CARS in the pathologic condition of acute pancreatitis was discussed. SIRS promotes excessive inflammatory reaction and CARS induces the susceptibility to infection. Both conditions can develop into organ failure in acute pancreatitis. Hence, countermeasures for both conditions are mandatory in the care of patients with acute pancreatitis. 相似文献
29.
Takahiro Tsujimura Masashi Takeda Nobuyuki Terada Hiroshi Uramoto 《Pathology international》1991,41(8):642-646
Two cases of peritoneal papillary carcinoma are reported. The patient in the first case was a 71-year-old woman with symptoms of obstructive ileus. Laparotomy revealed a tumor in the omentum involving the transverse colon, and several small tumors in the peritoneum and pelvic wall. However, no primary site of the tumor was seen in the ovary, pancreas, or gastrointestinal tract. The patient in the second case was a 44-year-old woman with carcinomatous peritonitis. Postmortem examination revealed multiple tumors in the peritoneum, omentum, and pelvic wall. Tumors were also found in the cortex with mild invasion of the underlying parenchyma of the bilateral ovaries, although these lesions were thought to be metastatic. The histologic features of the tumor in both cases were those of tubulopapillary adenocarcinoma containing scattered psammoma bodies. The cells were positive with the PAS D technique, but negative with alcian blue staining. In both cases, the serum levels of CA-125 were considerably elevated, and the tumor cells showed positivity for CA-125, S 100 protein, cytokeratin and EMA by im-munohistochemistry. The present cases were most likely peritoneal serous papillary adenocarcinoma derived from extraovarian peritoneal mesothelium with miillerian potential, being different from the usual type of diffuse malignant mesothelioma. Acta Pathol Jpn 41: 642-646, 1991. 相似文献
30.
Frequent co-localization of Cox-2 and laminin-5 gamma2 chain at the invasive front of early-stage lung adenocarcinomas 总被引:7,自引:0,他引:7
Niki T Kohno T Iba S Moriya Y Takahashi Y Saito M Maeshima A Yamada T Matsuno Y Fukayama M Yokota J Hirohashi S 《The American journal of pathology》2002,160(3):1129-1141
Laminin-5 is an extracellular matrix protein that plays a key role in cell migration and tumor invasion. Cox-2 is an induced isoform of cyclooxygenases that plays an important role in carcinogenesis, suppression of apoptosis, angiogenesis, and metastasis of colon cancer. We report frequent co-expression of cox-2 and laminin-5 at the invasive front of early-stage lung adenocarcinomas. We investigated the expression of cox-2 and laminin-5 immunohistochemically in 102 cases of small-sized lung adenocarcinoma (maximum dimension, 2 cm or less). Cox-2 and laminin-5 were expressed in 97 (95.1%) and 82 (80.4%) cases, respectively. Both were preferentially localized in cancer cells at the cancer-stroma interface, although cox-2 tended to show a diffuse staining pattern in some cases. A comparison of their staining patterns revealed a striking similarity in their distribution in 24 cases, and a partial overlap between their localization in another 20 cases. Moreover, an overall correlation was found between the expression levels of cox-2 and laminin-5 (P = 0.018). To gain insight into the mechanisms that regulate the expression of these proteins, we additionally studied their expression in 58 cases of stage I lung adenocarcinoma, in which p53 status was determined by immunohistochemistry, polymerase chain reaction-single strand conformation polymorphism analysis, and direct sequencing. The results showed that tumors with mutant p53 tended to express more cox-2 than those with wild-type p53 (P = 0.080). Also, tumors that overexpressed p53 had higher levels of cox-2 and laminin-5 than those without p53 overexpression (P = 0.032 and 0.047, respectively). Further immunohistochemical analysis showed that tumors that overexpressed both epidermal growth factor receptor (EGFR) and erbB-2 had higher levels of cox-2 and laminin-5 than those without concomitant overexpression of these proteins (P = 0.014 and P = 0.018, respectively). To see whether EGFR signaling is involved in cox-2 and laminin-5 expression, we further conducted in vitro analyses using six lung adenocarcinoma cell lines (A549, HLC-1, ABC-1, LC-2/ad, VMRC-LCD, and L27). Western blot analyses showed that cox-2 mRNA levels, and to a lesser extent laminin-5 gamma2 mRNA levels, correlated with the expression levels of erbB-2 and the phosphorylated form of MAPK/ERK-1/2 protein. The addition of transforming growth factor-alpha increased both cox-2 and laminin-5 gamma2 mRNA levels in A549, ABC-1, and L27 with different kinetics; the induction of cox-2 occurred earlier than that of laminin-5 gamma2. Finally, the migration of ABC-1 cells was inhibited by MAP kinase kinase inhibitor PD98059 and a selective cox-2 inhibitor NS-398. In contrast, the migration of A549 cells was inhibited by PD98059, but much less effectively by NS-398. These results suggest that co-stimulatory mechanisms may exist that increase the expression of cox-2 and laminin-5 at the invasive front of lung adenocarcinomas and that EGFR signaling could be one of the mechanisms. Further investigations are warranted concerning the role of cox-2 and laminin-5 in cancer cell invasion and the significance of p53 and EGFR signaling in the regulation of cox-2 and laminin-5 expression. 相似文献