全文获取类型
收费全文 | 15672篇 |
免费 | 746篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 112篇 |
儿科学 | 297篇 |
妇产科学 | 170篇 |
基础医学 | 1969篇 |
口腔科学 | 318篇 |
临床医学 | 1105篇 |
内科学 | 3970篇 |
皮肤病学 | 204篇 |
神经病学 | 998篇 |
特种医学 | 658篇 |
外科学 | 3176篇 |
综合类 | 51篇 |
预防医学 | 410篇 |
眼科学 | 253篇 |
药学 | 1236篇 |
中国医学 | 53篇 |
肿瘤学 | 1537篇 |
出版年
2023年 | 99篇 |
2022年 | 206篇 |
2021年 | 367篇 |
2020年 | 188篇 |
2019年 | 257篇 |
2018年 | 345篇 |
2017年 | 251篇 |
2016年 | 291篇 |
2015年 | 326篇 |
2014年 | 453篇 |
2013年 | 487篇 |
2012年 | 791篇 |
2011年 | 878篇 |
2010年 | 471篇 |
2009年 | 373篇 |
2008年 | 707篇 |
2007年 | 717篇 |
2006年 | 732篇 |
2005年 | 747篇 |
2004年 | 684篇 |
2003年 | 670篇 |
2002年 | 702篇 |
2001年 | 363篇 |
2000年 | 429篇 |
1999年 | 423篇 |
1998年 | 185篇 |
1997年 | 139篇 |
1996年 | 151篇 |
1995年 | 130篇 |
1994年 | 139篇 |
1993年 | 119篇 |
1992年 | 358篇 |
1991年 | 337篇 |
1990年 | 296篇 |
1989年 | 339篇 |
1988年 | 295篇 |
1987年 | 270篇 |
1986年 | 256篇 |
1985年 | 247篇 |
1984年 | 158篇 |
1983年 | 130篇 |
1982年 | 62篇 |
1979年 | 125篇 |
1978年 | 94篇 |
1977年 | 59篇 |
1975年 | 69篇 |
1974年 | 61篇 |
1973年 | 57篇 |
1972年 | 51篇 |
1969年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 4 毫秒
31.
Endogenous bone-marrow-derived stem cells contribute only a small proportion of regenerated myocardium in the acute infarction model. 总被引:6,自引:0,他引:6
Shinya Fukuhara Shinji Tomita Takeshi Nakatani Chikao Yutani Soichiro Kitamura 《The Journal of heart and lung transplantation》2005,24(1):67-72
BACKGROUND: Our recent study showed that granulocyte-colony stimulating factor (G-CSF) promoted bone-marrow cells (BMC) to migrate into the infarcted heart and that they differentiated into cardiomyocytes. However, we still do not know to what degree bone-marrow-derived cardiomyocytes contribute to myocardial regeneration after injury. In this study, we verified the proportional contribution of cells from bone marrow (BM) and from non-bone marrow (n-BM) in regenerating neomyocardium after myocardial infarction. METHODS: Eight C57BL/6 mice were irradiated (900 cGy), and green fluorescent protein (GFP) mouse-derived BMCs (GFP-BMC, 1 x 10(6) cells) were injected. Four weeks later, the left descending coronary artery was ligated. Recombinant human G-CSF (200 microg/kg/day, 8 days) was injected. At 4 weeks after ligation, hearts were fixed for histology. We calculated the proportions of cardiomyocytes derived from BM and n-BM after taking the chimeric rate into consideration. RESULTS: The chimeric rate was 54.6% +/- 5.9%. At the infarcted border area, the total cell number was 1000.3 +/- 56.5/mm(2), and mobilized BM-derived GFP-BMC was 103.3 +/- 13.1/mm(2). After compensation with the chimeric rate, we found BM-derived troponin I-positive cells at 23.9 +/- 4.1/mm(2), nestin-positive cells at 12.9 +/- 2.6/mm(2), and Ki67-positive cells at 18.3 +/- 2.6/mm(2), respectively. We found significant differences in the contribution of troponin I-(6.7% +/- 1.7% vs 93.3% +/- 1.7%), nestin- (2.4 +/- 0.5 vs 97.6 +/- 0.5), and Ki67-positive (3.9 +/- 1.0 vs 96.1 +/- 1.0) cells derived from BM and n-BM. CONCLUSIONS: Bone marrow was one of the origins of regenerated cardiomyocytes; however, the contribution of cells from BM was very small compared with those of n-BM origin in the infarction model. 相似文献
32.
Kenji Yamao Atsushi Irisawa Hiroyuki Inoue Koji Matsuda Mitsuhiro Kida Shomei Ryozawa Yoshiki Hirooka Teruo Kozu 《Digestive endoscopy》2007,19(Z1):S180-S205
Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented. 相似文献
33.
N Yoshimura T Asada H Matsuda H Nohara T Higami M Nishiwaki N Mukohara M Chibana K Ogawa 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(2):157-159
A 17-year-old male patient with Marfan syndrome was admitted due to recurrent bilateral pneumothorax which had recurred totally 11 times during the past 3 years. For the treatment of obstinately continuing right pneumothorax resection of bullae in combination with pleuropexy using OK 432 was effective. Two months thereafter Bentall operation with a composite graft consisting of a woven Dacron tube and a Bj?rk-Shiley 27 mm aortic valve prosthesis was performed for his anuloartic ectasia. Left pneumothorax recurred 2 weeks after Bentall operation. But it was treated successfully with OK 432 injection into the left pleural cavity. Now, he is doing well as a student. 相似文献
34.
35.
36.
M Azuma T Kashiwagi H Sawaoka H Kimm T Takehara H Matsuda S Fujita N Mitsutani T Koizumi 《Kaku igaku. The Japanese journal of nuclear medicine》1989,26(2):171-175
The changes in portal collaterals before and after Endoscopic Injection Sclerotherapy (EIS) for esophageal varices were studied by Single Photon Emission CT (SPECT). SPECT was performed for the intra-abdominal blood pool with 99mTc autologous red blood cells (RBC) in 17 patients with liver cirrhosis before and after EIS. Twenty mCi of 99mTc-RBC labeled by in vivo technique were administered intra-venously and tomographic imaging of the intra-abdominal vascular blood pool was performed as follows. For each subjects, 64 views were obtained over 360 degrees of elliptic rotation at 30 seconds per view. In 15 of 17 patients, blood pool images over coronary vein and/or short gastric vein area were clearly demonstrated on coronary images. In 9 of 15 patients, the pool of coronary vein or short gastric vein was disappeared or decreased after EIS. It is considered that intra-abdominal blood pool SPECT study is clinically useful for following up of hemodynamics of portal collaterals before and after EIS. 相似文献
37.
Four cases of trigeminal schwannoma with different clinical presentations are reported. Two patients had root-type tumors and two ganglion-type tumors. Computed tomography demonstrated the mass in each case, but extension of the tumor into Meckel's cave, displaced but uninvolved seventh and eighth cranial nerves, extension of the tumor into the orbit or into the infratemporal fossa, and other anatomical details were far more clearly shown by magnetic resonance imaging, which provided confirmation of the mass lesions in the base of the brain and within the posterior fossa. 相似文献
38.
The antitumor effects of 2'-C-cyano-2'-deoxy-1-beta-D- arabinofuranosylcytosine (CN-DAC), a synthetic 1-beta-D-arabinofuranosyl-cytosine (ara-C) derivative, were examined and compared with that of ara-C in murine tumors and in various human tumors using three different chemosensitivity tests. CNDAC extended the life span of mice bearing P388 leukemia. CNDAC had a unique in vitro antitumor spectrum for human cancers different from that of ara-C. Compared with ara-C, CNDAC was more effective in 10 human tumors (2 lung, 4 stomach and 4 osteosarcoma), equal in 2 tumors (lung and fibrosarcoma) and less potent in 11 tumors (4 lung, 4 osteosarcoma, bladder, renal and epidermoid). Characteristically CNDAC showed excellent activities against tumors, refractory to ara-C, such as HT-1080 human fibrosarcoma implanted in chick embryos or athymic mice, although its cytotoxicity against HT-1080 was almost equal to that of ara-C. Thus, CNDAC is an interesting and promising agent that should be considered for further detailed preclinical evaluation. 相似文献
39.
Gen Kawa Shigenari Kawakita Takashi Ohara Tadashi Matsuda 《International journal of urology》1997,4(3):327-328
A 2-year-old boy presented with an accessory scrotum associated with penoscrotal transposition and a perineal lipoma. He also had a retrocerebellar arachnoid cyst. The accessory scrotum was resected with concurrent scrotoplasty. The retrocerebellar arachnoid cyst was seen on a subsequent brain computed tomography scan and was left untreated because there was no evidence that the volume was increasing. 相似文献
40.