全文获取类型
收费全文 | 2373篇 |
免费 | 122篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 58篇 |
妇产科学 | 81篇 |
基础医学 | 379篇 |
口腔科学 | 23篇 |
临床医学 | 135篇 |
内科学 | 719篇 |
皮肤病学 | 45篇 |
神经病学 | 199篇 |
特种医学 | 58篇 |
外科学 | 236篇 |
综合类 | 2篇 |
预防医学 | 119篇 |
眼科学 | 35篇 |
药学 | 233篇 |
中国医学 | 4篇 |
肿瘤学 | 183篇 |
出版年
2023年 | 26篇 |
2022年 | 59篇 |
2021年 | 71篇 |
2020年 | 51篇 |
2019年 | 56篇 |
2018年 | 67篇 |
2017年 | 52篇 |
2016年 | 50篇 |
2015年 | 65篇 |
2014年 | 92篇 |
2013年 | 117篇 |
2012年 | 168篇 |
2011年 | 148篇 |
2010年 | 91篇 |
2009年 | 85篇 |
2008年 | 145篇 |
2007年 | 146篇 |
2006年 | 118篇 |
2005年 | 119篇 |
2004年 | 117篇 |
2003年 | 107篇 |
2002年 | 89篇 |
2001年 | 20篇 |
2000年 | 23篇 |
1999年 | 32篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 11篇 |
1995年 | 14篇 |
1994年 | 13篇 |
1993年 | 11篇 |
1992年 | 28篇 |
1991年 | 20篇 |
1990年 | 25篇 |
1989年 | 26篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 19篇 |
1985年 | 25篇 |
1984年 | 11篇 |
1983年 | 13篇 |
1982年 | 6篇 |
1979年 | 13篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 13篇 |
1972年 | 6篇 |
1971年 | 8篇 |
排序方式: 共有2514条查询结果,搜索用时 15 毫秒
1.
2.
3.
Decreases in sex hormone levels with menopause may bring about a number of consequences in women's general health and sexual well-being, especially when levels decline suddenly and prematurely, as in surgical menopause. In addition to the well-established role of estrogens in preserving the biological basis of sexual response, there is emerging evidence that androgens are significant independent determinants affecting sexual desire, activity and satisfaction, as well as mood, energy and other components of women's health. Hypoactive sexual desire disorder (HSDD), a persistent absence of sexual fantasies or thoughts and/or desire for and receptivity to sexual activity that causes personal distress, is experienced by some postmenopausal women. Even though conventional hormone therapy with estrogens or estrogens and progestogens may be effective for vaginal atrophy, increasing vaginal lubrication and reducing dyspareunia, it has not been shown to consistently increase sexual desire or activity and many women with sexual dysfunction remain unresponsive. Several recent, large, phase III studies have shown that the addition of transdermal testosterone to conventional hormone therapy can be helpful in surgically menopausal women presenting with HSDD. After 24 weeks of treatment in these studies, testosterone-treated women experienced significantly greater increases in satisfying sexual activity and sexual desire, and greater decreases in distress, than placebo-treated women. Accurate clinical assessment and individualized management of sexual symptoms are fundamentally important for all menopausal women with HSDD or other sexual problems. 相似文献
4.
Monolateral hypoplasia of the motor vagal nuclei in a case of sudden infant death syndrome 总被引:1,自引:1,他引:0
Veronica Macchi Rossella Snenghi Raffaele De Caro Anna Parenti 《Journal of anatomy》2002,200(2):195-198
During the development of motor vagal nuclei (MVN), the neuroblasts of the myeloencephalic basal plate migrate in the dorsolateral direction to form the dorsal motor vagal nucleus (DMVN) and ventrolaterally to form the ventral motor vagal nucleus (VMVN). Those neuroblasts that remain close to the median sulcus will form the hypoglossal nucleus. In support of the congenital origin of the alteration of the MVN in sudden infant death syndrome (SIDS), we report the case of an 8‐month‐old female child who was found dead in her cot. The neuropathological assessment revealed that the medullary triangle of the 4th ventricle floor was asymmetric, owing to the presence of three prominences to the left side of the median sulcus. The medial prominence corresponded to the hypoglossal nucleus, which showed a marked increase in the number of large neurons; the intermediate prominence corresponded to the DMVN whose large neurons were reduced and were recognizable mainly at the level of the medial fringe; the lateral prominence corresponded to the solitary nucleus. The left solitary tract showed a reduction of the transverse diameter. Also, the left VMVN showed marked reduction in the number of neurons. Inflammatory and astrocytic reactions were absent. We suggest that in SIDS cases the hypocellularity of the MVN and the increased number of neurons of the hypoglossal nucleus are intimately related, indicating a congenital alteration due to incomplete migration of the vagal neuroblasts with abnormality of the autonomic cardio‐respiratory control. 相似文献
5.
M Luigia Vaccario Maria A Valenti Anna Carullo Rossella Di Bartolomeo Salvatore Mazza 《Clinical EEG》2003,34(1):15-17
Benign neonatal sleep myoclonus (BNSM), characterized by myoclonic jerks of the extremities only in non-REM sleep, occurs in the first months of life with spontaneous disappearance within 3-4 months. We examined five siblings with typical BNSM, at the 3-10 years follow-up neurological examination. Psychomotor development, cognitive functions and EEG were completely normal. These cases confirm that BNSM is a self limited and nonepileptic disorder. 相似文献
6.
Polydeoxyribonucleotides and nitric oxide release from guinea-pig hearts during ischaemia and reperfusion. 总被引:1,自引:1,他引:0 下载免费PDF全文
E. Masini M. Lupini L. Mugnai S. Raspanti P. F. Mannaioni 《British journal of pharmacology》1995,115(4):629-635
1. Two polydeoxyribonucleotides, produced by the controlled hydrolysis of DNA of mammalian lung (defibrotide and its lower molecular weight fraction, P.O. 085 DV), were studied for their ability to modify the release of nitrite and the coronary flow in perfusates collected from isolated, normally perfused hearts of guinea-pigs and from hearts subjected to regional ischaemia and reperfusion. 2. In guinea-pig normally perfused hearts, both defibrotide (DFT) and its fraction, P.O. 085 DV, increase the amount of nitrite appearing in perfusates in a concentration-dependent fashion. At the highest concentration studied (10(-6) M), P.O. 085 DV was more effective than DFT. A concomitant increase in the coronary flow was observed. 3. The increase in nitrite in perfusates and the increase in coronary flow induced by both DFT and P.O. 085 DV were significantly reduced by NG-monomethyl-L-arginine (L-NMMA, 10(-4) M), an inhibitor of nitric oxide synthase (NOS). 4. The endothelium-dependent vasodilator, acetylcholine (ACh), enhances the formation of nitrite and the coronary flow. Both the increase in coronary flow and in the formation of nitrite were significantly reduced by L-NMMA (10(-4) M). 5. In guinea-pig hearts subjected to ischaemia and reperfusion, the effect of both compounds in increasing the amount of nitrite in perfusates was more evident and more pronounced with P.O. 085 DV. 6. Reperfusion-induced arrhythmias were significantly reduced by both compounds to the extent of complete protection afforded by compound P.O. 085 DV. 7. The cardioprotective and antiarrhythmic effects of DFT and P.O. 085 DV are discussed. 相似文献
7.
This study investigated the extent of impairment in functional parameters of liver mitochondria from rats treated for 60 days with hexachlorobenzene (HCB). A constant amount of mitochondrial uncoupling was found throughout the treatment period. At the same time a nearly constant amount of pentachlorophenol was detected in these mitochondria. In contrast, the level of mitochondrial porphyrins increased progressively. There was good correlation between the concentration of mitochondrial pentachlorophenol and the degree of uncoupling of oxidative phosphorylation. 相似文献
8.
9.
10.
Serum Interferon (IFN)-Neutralizing Antibodies and Bioactivities of IFNs in Patients with Severe Type II Essential Mixed Cryoglobulinemia 下载免费PDF全文
Carolina Scagnolari Milvia Casato Francesca Bellomi Francesca De Pisa Ombretta Turriziani Rossella Coviello Maria Rosaria Pirro Ferdinando Dianzani Guido Antonelli 《Clinical and Vaccine Immunology : CVI》2003,10(1):70-77
The efficacy of alpha interferon (IFN-α) in the treatment of severe type II essential mixed cryoglobulinemia (EMC) has been reported previously. In some patients, the development of neutralizing antibodies to recombinant IFN-α (rIFN-α) can affect the clinical response achieved with rIFN-α; a second treatment with natural IFN-α preparations may reinduce the clinical response. In the present study the ability of leukocyte IFN (LeIFN) to restore the response was investigated from a pharmacodynamic viewpoint. Specifically, the pharmacodynamic profiles of different IFN-α preparations were studied by measuring the serum neopterin levels and the levels of expression of protein MxA mRNA in in vivo peripheral blood mononuclear cells in two patients with EMC whose resistance to rIFN-α2a treatment increased concomitantly with the development of neutralizing antibodies. These markers were measured before injection and at 24 and 48 h after a single injection of rIFN-α2a, consensus IFN [(C)IFN], or LeIFN. No increase or only a slight increase in MxA mRNA levels was detectable after administration of rIFN-α2a or (C)IFN, whereas a significant increase (≥10-fold) in MxA mRNA expression was recorded following administration of LeIFN. The neutralizing antibodies to rIFN-α2a cross-react with (C)IFN. Sera from these patients neutralized most but not all of the subtypes present in the natural IFN-α (LeIFN) mixture, and no significant increase in neopterin levels was observed after these patients were switched to LeIFN treatment. In summary, the data demonstrate that the problem of neutralizing antibodies still exists and that LeIFN may induce an increase in the level of MxA mRNA expression but not an increase in neopterin levels in patients who are resistant to treatment with rIFN-α2a or (C)IFN. 相似文献