全文获取类型
收费全文 | 24645篇 |
免费 | 1258篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 151篇 |
儿科学 | 388篇 |
妇产科学 | 447篇 |
基础医学 | 3128篇 |
口腔科学 | 785篇 |
临床医学 | 1785篇 |
内科学 | 5833篇 |
皮肤病学 | 450篇 |
神经病学 | 2199篇 |
特种医学 | 1080篇 |
外科学 | 3853篇 |
综合类 | 107篇 |
预防医学 | 674篇 |
眼科学 | 466篇 |
药学 | 1940篇 |
中国医学 | 58篇 |
肿瘤学 | 2659篇 |
出版年
2023年 | 100篇 |
2022年 | 201篇 |
2021年 | 415篇 |
2020年 | 236篇 |
2019年 | 339篇 |
2018年 | 399篇 |
2017年 | 313篇 |
2016年 | 390篇 |
2015年 | 410篇 |
2014年 | 566篇 |
2013年 | 675篇 |
2012年 | 1079篇 |
2011年 | 1255篇 |
2010年 | 652篇 |
2009年 | 619篇 |
2008年 | 1072篇 |
2007年 | 1084篇 |
2006年 | 1077篇 |
2005年 | 1074篇 |
2004年 | 1036篇 |
2003年 | 1031篇 |
2002年 | 1077篇 |
2001年 | 940篇 |
2000年 | 952篇 |
1999年 | 938篇 |
1998年 | 331篇 |
1997年 | 265篇 |
1996年 | 246篇 |
1995年 | 202篇 |
1994年 | 186篇 |
1993年 | 173篇 |
1992年 | 665篇 |
1991年 | 573篇 |
1990年 | 609篇 |
1989年 | 587篇 |
1988年 | 503篇 |
1987年 | 460篇 |
1986年 | 451篇 |
1985年 | 408篇 |
1984年 | 284篇 |
1983年 | 237篇 |
1980年 | 96篇 |
1979年 | 244篇 |
1978年 | 145篇 |
1977年 | 131篇 |
1975年 | 100篇 |
1974年 | 98篇 |
1972年 | 106篇 |
1971年 | 104篇 |
1969年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Kota Sahara Rin Yamada Takashi Fujiwara Koichi Koizumi Shin‐ichiro Horiguchi Tsunekazu Hishima Tatsuro Yamaguchi 《Digestive endoscopy》2015,27(7):768-771
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76‐year‐old Japanese man presented to our hospital with a 1‐year history of worsening diarrhea, lower abdominal pain, and weight loss (−6 kg). Laboratory evaluation revealed white blood cell count of 13 200/μL, C‐reactive protein level of 2.0 mg/dL (normal range, 0.0–0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic. 相似文献
2.
3.
4.
5.
6.
7.
Experiments were performed on spinalized rats, transected at the Cl level. The intravenous administration of TRH and its analog YM-14673 (N alpha-[(S)-4-oxo-2-azetidinyl) carbonyl]-L-histidyl-L-prolinamide dehydrate) produced marked increases in the amplitude of mono- and polysynaptic reflex potentials and those of the withdrawal flexor reflexes. The effects of YM-14673 were stronger and longer-lasting than those of TRH. The stimulant action of TRH and YM-14673 on the flexor reflexes was not antagonized by prazosin, chlorpromazine, haloperidol or cyproheptadine, suggesting no involvement of the release of catecholamines or serotonin in the stimulant effects of TRH and its analog. Therefore, YM-14673 may be beneficial for the treatment of several spinal motor neuron diseases. 相似文献
8.
S Yamada 《Journal of UOEH》1988,10(2):211-218
Physical activity and nutrition are the most important factors in preserving and/or improving health conditions. The relationship between exercise and nutrition is focused on two different directions: one is the direction toward health promoting, the other is for performance of a long heavy muscular work. For preserving and/or promoting health conditions, energy balance between intake and expenditure must be taken into account. The amount of glycogen stored in muscles is the essential factor to promote a long distance performance of working muscles. Topics that influence the energy balance and glycogen loading used by endurance athletes to improve performance are reviewed. 相似文献
9.
Basic fibroblast growth factor prevents thalamic degeneration after cortical infarction 总被引:10,自引:0,他引:10
K Yamada A Kinoshita E Kohmura T Sakaguchi J Taguchi K Kataoka T Hayakawa 《Journal of cerebral blood flow and metabolism》1991,11(3):472-478
In the focal infarction model of the rat middle cerebral artery (MCA), the thalamus of the occluded side becomes gradually atrophic, mainly because of retrograde degeneration. We determined whether basic fibroblast growth factor (bFGF) administered intracisternally could prevent this thalamic atrophy. We occluded the left MCA through a small cranial opening, and animals were then divided into two groups. One group received intracisternal injections of recombinant bFGF (1 microgram dissolved in 0.1 ml of saline with 2% rat serum) starting 1 day after occlusion and repeated once a week to a total dose of 4 micrograms by four injections. The other group received vehicle solution by the same schedule. The animals were perfused and fixed at 28 days after occlusion, and histological examination was made at the level of the caudoputamen and thalamus. In the bFGF-treated rats, the area of the posterior ventral thalamus of the occluded side was 93% of that of the contralateral side, i.e., significantly larger than in the normal saline-treated rats (75%, p less than 0.01). The infarction size was not statistically different in the two groups. Microscopic observation indicated that normal-saline-treated animals showed shrinkage and disappearance of thalamic neurons, whereas bFGF-treated groups showed preservation of thalamic neurons. Computerized analysis of the cell size substantiated this observation. To assess the effect of bFGF on astrocytes, bFGF or vehicle solution was injected into normal rats, and their histology was evaluated at 1, 2, and 4 weeks after injection. The bFGF-injected group showed a significant increase in glial fibrillary acidic protein-positive astrocytes in the brain tissue facing the ventriculocisternal system.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
10.
Mitsumasa Iwata Shunji Izuta Motoshi Suzuki Kiyohide Kojima Yoshihito Furuhashi Yutaka Tomoda Shonen Yoshida 《Cancer science》1991,82(4):433-439
We examined the mechanisms of the inhibition of DNA synthesis by a new platinum compound, (-)-( R )-2-aminomethylpyrrolidine(1,1-cyclobutane-dicarboxylato)-2-platinum(II) monohydrate (DWA-2114R), a derivative of the antitumor drug cis- diamminedichloroplatinum(II) (CDDP), using prokaryotic and eukaryotic DNA polymerases. Preincubating activated DNA with CDDP or DWA-2114R reduced its template activity for prokaryotic and eukaryotic DNA polymerases in a dose-dependent manner. DWA2114R required six times greater drug concentration and two times longer incubation time to show the same decrease of the template activity compared to CDDP. Treatment of primed pUC118 ssDNA templates with the two drugs followed by second-strand synthesis by prokaryotic and eukaryotic DNA polymerases revealed that DWA2114R bound to DNA in a similar manner to CDDP and these adducts blocked DNA elongation by DNA polymerases of eukaryotes as well as of prokaryotes. With these two drugs, the elongations by E. coli DNA polymerase I (Klenow fragment), T7 DNA polymerase and calf thymus DNA polymerase α were strongly arrested at guanine-guanine sequences (GG). Stop bands were also observed at adenine-guanine sequences (AG) guanine-adenine-guanine sequences (GAG) and mono-guanine sequence (G). Calf testis DNA polymerase β was also arrested efficiently at AG, GAG and G, but much more weakly at GG. This pattern was common to DWA2114R and CDDP. 相似文献