全文获取类型
收费全文 | 11368篇 |
免费 | 630篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 614篇 |
妇产科学 | 220篇 |
基础医学 | 1674篇 |
口腔科学 | 114篇 |
临床医学 | 767篇 |
内科学 | 2371篇 |
皮肤病学 | 262篇 |
神经病学 | 573篇 |
特种医学 | 338篇 |
外国民族医学 | 1篇 |
外科学 | 1154篇 |
综合类 | 467篇 |
一般理论 | 7篇 |
预防医学 | 752篇 |
眼科学 | 497篇 |
药学 | 992篇 |
中国医学 | 85篇 |
肿瘤学 | 1016篇 |
出版年
2023年 | 73篇 |
2022年 | 216篇 |
2021年 | 360篇 |
2020年 | 153篇 |
2019年 | 210篇 |
2018年 | 287篇 |
2017年 | 202篇 |
2016年 | 253篇 |
2015年 | 287篇 |
2014年 | 388篇 |
2013年 | 496篇 |
2012年 | 670篇 |
2011年 | 722篇 |
2010年 | 413篇 |
2009年 | 349篇 |
2008年 | 533篇 |
2007年 | 608篇 |
2006年 | 562篇 |
2005年 | 490篇 |
2004年 | 445篇 |
2003年 | 403篇 |
2002年 | 374篇 |
2001年 | 298篇 |
2000年 | 286篇 |
1999年 | 229篇 |
1998年 | 92篇 |
1997年 | 72篇 |
1996年 | 69篇 |
1995年 | 58篇 |
1993年 | 49篇 |
1992年 | 154篇 |
1991年 | 145篇 |
1990年 | 127篇 |
1989年 | 134篇 |
1988年 | 155篇 |
1987年 | 122篇 |
1986年 | 123篇 |
1985年 | 122篇 |
1984年 | 103篇 |
1983年 | 67篇 |
1982年 | 49篇 |
1979年 | 73篇 |
1978年 | 68篇 |
1977年 | 54篇 |
1976年 | 55篇 |
1974年 | 60篇 |
1973年 | 68篇 |
1972年 | 51篇 |
1971年 | 59篇 |
1970年 | 58篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
101.
Sephton R Das KR Coles J Toye W Pinder P 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》1999,22(3):113-117
A high-dose rate brachytherapy facility was installed into an established operating theatre by using local shielding in the form of mobile lead screens and by taking advantage of the ease with which staff movements can be controlled in an operating suite. This facility was inexpensive to develop, and has proved clinically efficient and entirely adequate from a radiation safety standpoint. 相似文献
102.
Whole cell and five different types of acellular pertussis vaccine were assayed using a mouse aerosol challenge model which permitted delivery of a controlled, consistent dose of Bordetella pertussis to the lower respiratory tract. Using this system, the viable counts in the lungs of vaccinated mice were immunisation dose-dependent and allowed the protective capacity of different vaccine preparations to be distinguished. This model may thus provide the basis for a protection assay for pertussis vaccines. Comparison of acellular vaccines with a whole cell pertussis vaccine showed that the latter gave better active protection in mice but with a different dose-response relationship. Thus the two types of vaccine are not directly comparable in the same assay and require different reference standards. A pentavalent type acellular vaccine is suggested as a possible candidate standard for the acellular vaccine potency test. The results suggest that this aerosol challenge model has potential for use as a potency test for acellular pertussis vaccines. 相似文献
103.
Inhibition of herpes simplex virus type 1 and adenovirus type 5 by heterocyclic Schiff bases of aminohydroxyguanidine tosylate 总被引:3,自引:0,他引:3
Eleven heterocyclic Schiff bases of aminohydroxyguanidine tosylate (SB-AHGs), compounds I-XI, were tested for antiviral activity against herpes simplex virus type 1 (HSV-1) and adenovirus type 5 (Ad 5) via plaque reduction and virus yield reduction assays. This work was undertaken to test the hypothesis that low molecular weight SB-AHGs (MW < 235 for the free SB) make better antiviral agents than high MW SB-AHGs (MW > 300). The plaque reduction assay method demonstrated that three compounds, I, VII and IX, had moderate activity against HSV-1, with 50% inhibitory concentration (IC50) values of 38.0, 23.5 and 52.1 microM, respectively. Against Ad 5, compounds I, VIII and XI exhibited moderate activity, with IC50 values of 52.7, 19.3 and 5.1 microM, respectively. Among the compounds screened, compound I (1-[(3'-hydroxy-6'-methyl-2'-pyridyl)methylene]amino-3-hydroxyguanidi ne tosylate) was the most promising antiviral candidate, with selectivity indices (SI) of 10.2 (HSV-1) and 7.6 (Ad 5), respectively. Virus yield reduction assays indicated that compound I had less antiviral potency against HSV-1 than against Ad 5. The antiviral effects of compound I at a high input virus multiplicity of infection (MOI > 5) indicated that compound I had effective anti-adenoviral activity at 24 h post infection. This work demonstrated that some of SB-AHGs only have moderate antiviral activities against Ad 5 and HSV-1 viruses. In general, low MW SB-AHGs have low cytotoxicities to the host cells. 相似文献
104.
Das J 《Indian journal of dermatology, venereology and leprology》1996,62(5):312-313
A 17 years old boy presented clinically with typical lesions of pustular posriasis. Although his pus culture from the pocket of pus did not reveal any organism, his blood culture reports showed growth of Diplococci pneumoniae, which was sensitive to gentamycin. The patient was completely cured of the lesion after gentamycin therapy. 相似文献
105.
106.
The lactate dehydrogenase (LDH) activity of garden lizard brain did not change with advancing age. On the other hand the succinate dehydrogenase (SDH) activity showed a decline during maturation (young to middle-aged) remaining stabilized thereafter. Seven days of partial water deprivation did not alter the LDH activity of lizards of all three age groups but caused an increase in SDH activity of old lizards only. Restricted feeding led to a decline in the activities of both the enzymes (LDH and SDH) in young lizards and an increase in LDH activity of only the old, the response in middle-aged being insignificant. The protein content of the brain did not change during maturation, but declined in old lizards. Partial water deprivation caused an increase in protein content of the brain of both middle-aged and old lizards but not in young counterparts. Only the young lizards showed an increase in protein content of the brain in response to food restriction. 相似文献
107.
Effects of vitamin B-6 deficiency on the developing central nervous system of the rat. Myelination 总被引:1,自引:0,他引:1
The effects of different levels of dietary pyridoxine (1.0, 1.2, 1.4, and 20.0 mg/kg diet) fed to dams during growth, gestation and lactation on myelination in progeny were investigated. Degree of myelination at 15 days, postnatally, was determined from closely matched micrographs of the four dietary treatment groups. Electron micrographs showed markedly less myelination in the 1.0 group as compared with the 1.4 and 20.0 groups with the 1.2 group appearing intermediate in the number of myelinated axons. Some myelinated axons of the 1.0 group exhibited an "unusual" appearance of whorls of lamina separated by cytoplasmic space occupied by widely separated lamina. The results indicate that brain development, particularly myelination, was affected by a deficiency of vitamin B-6 prior to and including the period of rapid myelination. 相似文献
108.
The action of copper (CuSO4, 5mg/kg, oral) on selected neuropharmacological actions of cannabis resin (CI, oral) was studied on albino rats and mice. Copper potentiated the barbiturate hypnosispotentiating activity of CI in albino rats and mice and had no effect on hypothermic activity in albino rats.Single doses of copper partially inhibited tolerance to barbiturate hypnosis-potentiation activity and markedly delayed the development of tolerance to hypothermic activity of CI. Oral as well as i.c.v. copper (CuSO4, 0.1 g) in single dose antagonised the tolerance to hypothermic activity of cannabis or THC for to two weeks. Copper-CI interaction could be antagonised by penicillamine. Zinc (ZnSO4, 5 mg/kg, oral) had an action similar to that of copper in antagonising the development of tolerance to the hypothermic activity of CI, but magnesium (MgSO4, 5 mg/kg, i.p.) was devoid of any such action.Studies indicate that, although copper has no significant neuropharmacological action, it interacts with CI activity, especially in tolerant rats, in effects on hypothermia. The site of action of copper is possibly the hypothalamus, where it inhibits the processes of tolerance development to CI on the noradrenergic neurone. 相似文献
109.
The authors present a case of radiation-induced pacemaker failure. After 2,000 rad (20 Gy) of photon irradiation for metastatic bronchogenic carcinoma, the pulse generator circuitry failed, producing a "runaway" rhythm. This suggests that present pacemaker circuitry may be more susceptible to irradiation than previously believed, and that even modest radiation doses can induce life-threatening arrhythmias. 相似文献
110.
The synthesis and release of procoagulant activity (PCA) from leukaemic leucocytes was studied in anin vitro culture system stimulated by endotoxin. Puromycin, actinomycin-D, vinblastine, colchicine, dibutyryl cyclic AMP and ouabaln were added to the culture system to study some of the metabolic processes of these cells in relation to synthesis and release of PCA. It was found that production of PCA is an active process and depends on new protein synthesis. The release of PCA from cells can be inhibited by vinblastine, an inhibitor of microfilament and microtubules in the cell. The optimal release of PCA occurs at pH 7.2-@#@ 7.4 at 37°C and is not inhibited by the ATPase inhibitor ouabaln. Dibutyryl cyclic AMP inhibits the release/synthesis of PCA. Gram negative septicaemia and endotoxinaemia are capable of increased production and release of PCA from leukaemic cells and could contribute to the coagulation fallure seen in this disease. 相似文献