全文获取类型
收费全文 | 196848篇 |
免费 | 1954篇 |
国内免费 | 161篇 |
专业分类
耳鼻咽喉 | 1362篇 |
儿科学 | 7001篇 |
妇产科学 | 3318篇 |
基础医学 | 19044篇 |
口腔科学 | 2307篇 |
临床医学 | 13656篇 |
内科学 | 36252篇 |
皮肤病学 | 1328篇 |
神经病学 | 17850篇 |
特种医学 | 9948篇 |
外科学 | 32740篇 |
综合类 | 2404篇 |
一般理论 | 2篇 |
预防医学 | 18601篇 |
眼科学 | 3234篇 |
药学 | 10591篇 |
中国医学 | 668篇 |
肿瘤学 | 18657篇 |
出版年
2023年 | 94篇 |
2022年 | 181篇 |
2021年 | 407篇 |
2020年 | 288篇 |
2019年 | 319篇 |
2018年 | 22231篇 |
2017年 | 17633篇 |
2016年 | 19826篇 |
2015年 | 1301篇 |
2014年 | 1370篇 |
2013年 | 1447篇 |
2012年 | 8006篇 |
2011年 | 22054篇 |
2010年 | 19538篇 |
2009年 | 12071篇 |
2008年 | 20588篇 |
2007年 | 22816篇 |
2006年 | 1730篇 |
2005年 | 3376篇 |
2004年 | 4507篇 |
2003年 | 5387篇 |
2002年 | 3635篇 |
2001年 | 812篇 |
2000年 | 1030篇 |
1999年 | 763篇 |
1998年 | 556篇 |
1997年 | 459篇 |
1996年 | 366篇 |
1995年 | 345篇 |
1994年 | 290篇 |
1993年 | 234篇 |
1992年 | 370篇 |
1991年 | 435篇 |
1990年 | 465篇 |
1989年 | 448篇 |
1988年 | 390篇 |
1987年 | 324篇 |
1986年 | 278篇 |
1985年 | 287篇 |
1984年 | 195篇 |
1983年 | 164篇 |
1982年 | 115篇 |
1980年 | 127篇 |
1979年 | 161篇 |
1978年 | 120篇 |
1977年 | 106篇 |
1976年 | 92篇 |
1974年 | 121篇 |
1973年 | 82篇 |
1969年 | 90篇 |
排序方式: 共有10000条查询结果,搜索用时 765 毫秒
41.
42.
43.
A prognosis of patients with a curative resected advanced cancer of the lower gastric region was worse than that of the other region of the stomach. The 5 year survival rate was only 47.3%. One of the main reasons was that a rate of lymph node recurrence was higher. In this point of view, we studied on lymphatic flow of the lower gastric region using an activated carbon particle (CH40). Lymph nodes were stained black soon after the injection of CH40 into the lower gastric wall at laparotomy. The black stained rate of an each regional lymph node was as follows. 3. 58%, 4. 17%, 5. 50%, 6. 25%, 1. 21%, 7. 58%, 8. 83%, 9. 58%, 11. 17% and 12. 33% in case of injection into the greater curvature and and 4. 31%, 6. 100%, 8. 25%, 9. 25%, 14V and 56% in case of injection into the lesser curvature. The stained rate was relatively high in 12 and 14V lymph node which we had not routinely dissected. The rates of lymph nodes stained black were related to those of cancer metastasis. The results suggest that lymphadenectomy of 12 for the cancer at the lesser curvature and that of 14V for the cancer at the greater curvature might make a prognosis of lower gastric cancer better. 相似文献
44.
High incidence of nitrosamine-induced tumorigenesis in mice lacking DNA repair methyltransferase 总被引:12,自引:4,他引:8
Iwakuma T; Sakumi K; Nakatsuru Y; Kawate H; Igarashi H; Shiraishi A; Tsuzuki T; Ishikawa T; Sekiguchi M 《Carcinogenesis》1997,18(8):1631-1635
The enzyme O6-methylguanine-DNA methyltransferase repairs alkylation-
induced DNA damage, O6-methylguanine and O4-methylthymine, the former being
formed more frequently. Previously, by means of gene targeting, we
generated mice in which alleles for methyltransferase were disrupted. We
now use these mouse lines, which are totally deficient in methyltransferase
activity, to examine protective effects of the enzyme against tumor
formation. In gene-targeted female mice given an i.p. injection of 5 mg/kg
of dimethylnitrosamine, a larger number of liver and lung tumors occurred,
as compared with normal female mice treated in the same manner. In male
mice given a lower dose of carcinogen, the difference between normal and
gene-targeted mice was statistically insignificant although more tumors did
form in the gene-targeted mice. Methyltransferase apparently afforded
protection from nitrosamine- induced tumorigenesis.
相似文献
45.
Yuji Morimoto Osamu Kemmotsu Koichi Kitami Izumi Matsubara Ichiro Tedo 《Journal of anesthesia》1995,9(1):22-26
We evaluated whether we could predict the neurologic outcome in 55 out-of-hospital cardiac arrest patients using auditory
brainstem responses (ABR). ABR patterns were classified into one of 3 types by evaluation of 5 components: type 1, with all
5 components; type 2, lack of at least one response between the 2nd and 5th components; type 3, with only the first component
or no response. The relation between the ABR patterns on the 3rd day following resuscitation and the neurologic outcome on
hospital discharge was evaluated. The specificity that the 5 awake patients had type-1 ABR was 38%. The sensitivity that the
10 brain dead patients had type-3 ABR was 60%. In the type-1 ABR patients, the negative predictive value that the patients
were awake was 100%. In the type-3 ABR patients, the negative predictive value that the patients became brain dead was 90.9%.
These results suggest that ABR on the 3rd post-resuscitation day may not be useful for predicting if patients are awake or
become brain dead, although the loss of components may be a sign of morbidity, and the presence of the 2nd or later components
indicates possible future prevention of brain death. 相似文献
46.
Irwin L. Flink 《Brain structure & function》2002,205(3):235-244
47.
IgG-maleimide peroxidase, Fab'-maleimide peroxidase, polymer and monomer types of Fab'-periodate peroxidase were prepared from an antibody against rat lipoamide dehydrogenase, a component of the pyruvate dehydrogenase complex which is located in mitochondria. They were examined for immunohistochemical staining of the rat kidney. Fab'-maleimide peroxidase was the best for staining mitochondrial protein. IgG-maleimide peroxidase and the monomer type of Fab'-periodate peroxidase had the same intensity of staining. The polymer type of Fab'-periodate peroxidase could not stain the lipoamide dehydrogenase. 相似文献
48.
49.
50.
Tanaka Takeo Kobayashi Masao Saito Osamu Kamada Nanao Kuramoto Atsushi Usui Tomofusa 《Clinica chimica acta; international journal of clinical chemistry》1981,117(2):121-131
The biochemical activities of 8 lysosomal acid hydrolases in leukemic cells from 48 patients were examined. Characteristic alterations were found in α-mannosidase, β-galactosidase and N-acetyl-β-glucosaminidase activities of leukemic cells. The level of α-mannosidase activity was much higher in myelo(mono)genous leukemias (AML, AMoL, AMMoL, CML and CMMoL) than in lymphogenous ones (ALL, T-cell leukemia, hairy cell leukemia and CLL) without exception. The β-galactosidase activity also differed as a result of α-mannosidase, except in T-cell leukemia. In T-cell leukemia it was within the range of normal lymphocytes, but in the other lymphogenous leukemias it was significantly below normal. N-acetyl-β-glucosaminidase activity in myelo(mono)genous leukemic cells was above the range of normal granulocytes. The changes in these enzyme levels were consistent. The lymphocytic or myelocytic nature of three cases of acute undifferentiated leukemia could be determined by enzyme studies. In two cases it was lymphocytic and in one it was myelocytic. The enzymatic abnormalities were also found in morphologically mature neutrophils from patients with not only chronic types (CML, CMMoL) but also acute types (AMoL, AMMoL) of leukemias, and were similar to those of their respective leukemic cells. Analysis of lysosomal enzymes (at least three of those mentioned above), can elucidate one of the biochemical properties of leukemic cells and may be valuable in the differentiation of leukemias. 相似文献