全文获取类型
收费全文 | 213227篇 |
免费 | 14914篇 |
国内免费 | 898篇 |
专业分类
耳鼻咽喉 | 2214篇 |
儿科学 | 5580篇 |
妇产科学 | 4305篇 |
基础医学 | 30579篇 |
口腔科学 | 5113篇 |
临床医学 | 20431篇 |
内科学 | 44942篇 |
皮肤病学 | 3788篇 |
神经病学 | 20443篇 |
特种医学 | 8640篇 |
外国民族医学 | 51篇 |
外科学 | 30886篇 |
综合类 | 2419篇 |
现状与发展 | 2篇 |
一般理论 | 217篇 |
预防医学 | 15803篇 |
眼科学 | 4348篇 |
药学 | 14935篇 |
1篇 | |
中国医学 | 406篇 |
肿瘤学 | 13936篇 |
出版年
2023年 | 892篇 |
2022年 | 1407篇 |
2021年 | 3784篇 |
2020年 | 2555篇 |
2019年 | 3674篇 |
2018年 | 4495篇 |
2017年 | 3388篇 |
2016年 | 3918篇 |
2015年 | 4527篇 |
2014年 | 6290篇 |
2013年 | 8977篇 |
2012年 | 13293篇 |
2011年 | 14022篇 |
2010年 | 8444篇 |
2009年 | 7793篇 |
2008年 | 12817篇 |
2007年 | 13638篇 |
2006年 | 13099篇 |
2005年 | 13198篇 |
2004年 | 12686篇 |
2003年 | 11909篇 |
2002年 | 11404篇 |
2001年 | 3621篇 |
2000年 | 3307篇 |
1999年 | 3544篇 |
1998年 | 2946篇 |
1997年 | 2340篇 |
1996年 | 2035篇 |
1995年 | 1930篇 |
1994年 | 1673篇 |
1993年 | 1690篇 |
1992年 | 2215篇 |
1991年 | 2166篇 |
1990年 | 1937篇 |
1989年 | 1910篇 |
1988年 | 1655篇 |
1987年 | 1664篇 |
1986年 | 1547篇 |
1985年 | 1491篇 |
1984年 | 1325篇 |
1983年 | 1209篇 |
1982年 | 1204篇 |
1981年 | 1139篇 |
1980年 | 974篇 |
1979年 | 986篇 |
1978年 | 748篇 |
1977年 | 754篇 |
1976年 | 636篇 |
1975年 | 663篇 |
1974年 | 663篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
171.
5-Amino-4-imidazolecarboxamide (AICA) riboside, the nucleoside corresponding to AICA ribotide (AICAR or ZMP), an intermediate of the de novo pathway of purine biosynthesis, was found to exert a dose-dependent inhibition on gluconeogenesis in isolated rat hepatocytes. Production of glucose from lactate-pyruvate mixtures was half-maximally inhibited by approximately 100 microM and completely suppressed by 500 microM AICA riboside. AICA riboside also inhibited the production of glucose from all other gluconeogenic precursors investigated, i.e., fructose, dihydroxyacetone, and L-proline. Measurements of intermediates of the glycolytic-gluconeogenic pathway showed that AICA riboside provoked elevations of triose phosphates and fructose-1,6-bisphosphate and decreases in fructose-6-phosphate and glucose-6-phosphate. The effects of AICA riboside persisted when the cells were washed 10 min after its addition but were suppressed by 5-iodotubercidin, an inhibitor of adenosine kinase. AICA riboside provoked a dose-dependent buildup of normally undetectable Z nucleotides. After 20 min of incubation with 500 microM AICA riboside, ZMP, ZTP, and ZDP reached 3, 0.3, and 0.1 mumol/g cells, respectively. Concentrations of ATP were not significantly modified by addition of up to 500 microM AICA riboside when the cells were incubated with lactate-pyruvate but decreased with fructose or dihydroxyacetone. The activity of rat liver fructose-1,6-bisphosphatase was inhibited by ZMP with an apparent Ki of 370 microM. It is concluded that AICA riboside exerts a suppressive effect on gluconeogenesis because it provokes an accumulation of ZMP, which inhibits fructose-1,6-bisphosphatase.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
172.
173.
Nauman A Chaudhry Alejandro J Lavaque Anish Shah Peter E Liggett 《Ophthalmic surgery, lasers & imaging》2005,36(1):70-72
The authors describe the use of photodynamic therapy with verteporfin for subfoveal choroidal neovascular membrane secondary to optic nerve drusen. A 28-year-old woman had a peripapillary choroidal neovascular membrane secondary to optic nerve drusen with significant metamorphopsia. Photodynamic therapy using verteporfin was performed. Visual acuity improved to 20/20 with resolution of metamorphopsia and absence of leakage on fluorescein angiography a few weeks after verteporfin therapy. The patient's condition remained stable for 16 months with 20/20 vision. Photodynamic therapy with verteporfin may be a useful treatment option in patients with choroidal neovascular membranes secondary to optic nerve drusen. 相似文献
174.
175.
176.
177.
W. A. A. Tjalma M. Arbyn† J. Paavonen‡ T. R. Van Waes & J. J. Bogers§ 《International journal of gynecological cancer》2004,14(5):751-761
Persistent infection with one of the oncogenic human papillomavirus (HPV) types is a necessity for the development of cervical cancer. By HPV vaccination, cervical cancer could become a very rare disease. Two types of HPV vaccines can be distinguished: (i) therapeutic vaccines which induce cellular immunity targeted against epithelial cells infected with HPV and (ii) prophylactic vaccines inducing virus-neutralizing antibodies protecting against new but not against established infections. At present, several vaccines have been developed and tested in clinical trials. The vaccines are generally well tolerated and highly immunogenic. The current clinical data indicate that prophylactic vaccines are very effective against new persistent infections and the development of cervical intraepithelial lesions. The protection is type specific. However, the follow-up of the vaccination trials is still short. The effect of HPV vaccines on future cancer incidence will only be known after decades of follow-up. This article will address the status of recently terminated phase II and currently running phase III trials with prophylactic HPV vaccines. 相似文献
178.
This was a retrospective observational study of 11 consecutive patients of major primary postpartum haemorrhage (PPH) who had the B-Lynch suture at the time of caesarean section, performed between 1 March 2001 and 31 March 2004 at a teaching hospital in Scotland. Case-note review was performed in 123 patients, who had major primary PPH to identify patients who had B-Lynch sutures at the time of caesarean section. The patient's age, parity, gestation of pregnancy at which the B-Lynch suture was performed, the indication for caesarean section and the cause of primary major PPH were recorded. The operative details, intraoperative and immediate postoperative complications and the need for subsequent hysterectomy were noted. The patients were followed-up with clinic visits at 6 weeks and any further hospital referral for late postoperative complications and whether subsequent successful pregnancy was achieved, were documented. The incidence of major PPH in our centre was 0.5% of the total deliveries, of which 11 cases had the B-Lynch suture applied at the time of caesarean section. The patients were aged between 25 and 38 years old (mean 31 years). Parity ranged from 0 to 1 and the gestational age at which the procedure was performed ranged from 34 to 41 weeks (mean 38 weeks). Ten operations (91%) were performed by senior registrars supervised by the consultant on call and one (9%) case was performed by a consultant on call. All cases had the B-Lynch sutures performed for major primary PPH caused by uterine atony at the time of caesarean section. The weight of the babies delivered ranged between 2,110 - 4,820 g (mean 3,500 g). The total blood loss at surgery ranged from 2,000 - 10,000 ml (mean 3,500 ml). Only three patients (28%) required hysterectomy. All the patients made a good postoperative recovery. The hospital stay ranged from 4 - 24 days (mean 8 days). The patient who remained in hospital for 24 days did so because her baby was admitted into the neonatal unit. All the patients were reviewed 6 weeks postnatally. There was no significant morbidity. A subsequent successful pregnancy has been achieved in one patient. 相似文献
179.
180.