全文获取类型
收费全文 | 21014篇 |
免费 | 1544篇 |
国内免费 | 161篇 |
专业分类
耳鼻咽喉 | 177篇 |
儿科学 | 540篇 |
妇产科学 | 736篇 |
基础医学 | 2854篇 |
口腔科学 | 377篇 |
临床医学 | 2296篇 |
内科学 | 4299篇 |
皮肤病学 | 407篇 |
神经病学 | 1972篇 |
特种医学 | 649篇 |
外科学 | 2375篇 |
综合类 | 412篇 |
现状与发展 | 1篇 |
一般理论 | 3篇 |
预防医学 | 1456篇 |
眼科学 | 531篇 |
药学 | 1568篇 |
4篇 | |
中国医学 | 219篇 |
肿瘤学 | 1843篇 |
出版年
2023年 | 226篇 |
2022年 | 366篇 |
2021年 | 734篇 |
2020年 | 468篇 |
2019年 | 694篇 |
2018年 | 707篇 |
2017年 | 525篇 |
2016年 | 555篇 |
2015年 | 677篇 |
2014年 | 855篇 |
2013年 | 1184篇 |
2012年 | 1656篇 |
2011年 | 1770篇 |
2010年 | 997篇 |
2009年 | 800篇 |
2008年 | 1304篇 |
2007年 | 1280篇 |
2006年 | 1183篇 |
2005年 | 1070篇 |
2004年 | 1013篇 |
2003年 | 875篇 |
2002年 | 841篇 |
2001年 | 307篇 |
2000年 | 256篇 |
1999年 | 253篇 |
1998年 | 155篇 |
1997年 | 117篇 |
1996年 | 90篇 |
1995年 | 105篇 |
1994年 | 94篇 |
1993年 | 90篇 |
1992年 | 156篇 |
1991年 | 137篇 |
1990年 | 105篇 |
1989年 | 79篇 |
1988年 | 73篇 |
1987年 | 90篇 |
1986年 | 40篇 |
1985年 | 62篇 |
1984年 | 72篇 |
1983年 | 46篇 |
1982年 | 56篇 |
1981年 | 49篇 |
1980年 | 49篇 |
1979年 | 43篇 |
1978年 | 39篇 |
1977年 | 31篇 |
1976年 | 33篇 |
1975年 | 34篇 |
1974年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Antiproliferative effects of A02011-1, an adenylyl cyclase activator, in cultured vascular smooth muscle cells of rat. 下载免费PDF全文
1. The effects of A02011-1, a pyrazole derivative, on the proliferation of rat vascular smooth muscle cells (VSMCs) were examined. 2. A02011-1 (1-100 microM) concentration-dependently inhibited [3H]-thymidine incorporation into DNA in rat VSMCs that were synchronized by 48 h serum depletion and then re-stimulated by addition of foetal calf serum (FCS, 10%), platelet-derived growth factor (PDGF, 10 ng ml-1), 5-hydroxytryptamine (10 microM) or ADP (10 microM). The inhibitory effect of A02011-1 was fully reversible. However, FCS-induced [3H]-thymidine incorporation into rat endothelial cells was unaffected by A02011-1. 3. The concentration of A02011-1 necessary for inhibition of the FCS-induced proliferation was similar to that necessary for adenosine 3':5'-cyclic monophosphate (cyclic AMP) formation. Adenylyl cyclase activity was increased in A02011-1-treated VSMCs, whereas cyclic AMP-specific phosphodiesterase activity was unchanged. 4. A02011-1 was equipotent with forskolin but was more potent than 8-bromo-cyclic AMP against FCS (10%)-induced proliferation. 5. The antiproliferative action of A02011-1 was mimicked by 8-bromo-cyclic AMP, a membrane-permeable cyclic AMP analogue and was antagonized by 2',5'-dideoxyadenosine, an adenylyl cyclase inhibitor and by Rp-cyclic AMPS, a competitive inhibitor of cyclic AMP-dependent protein kinase (PKA) type I and II. 3-Isobutyl-1-methylxanthine (IBMX) caused significant potentiation of the antiproliferative activity of A02011-1. However, Rp-8-bromo-cyclic GMPS and staurosporine did not affect the antiproliferative activity of A02011-1.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
32.
33.
BACKGROUND: A venous lake is a venous ectasia that appears mostly on the lower lip and other sun-exposed areas of an older person. Treatment of lip venous lake includes surgical excision, laser therapy, infrared coagulation, and cryotherapy. Although the use of sclerotherapy on varicose veins, leg telangiectasia, hemorrhoids, and hemangiomas is well established, the use of sclerotherapy for lip venous lake has not been reported. OBJECTIVE: We present two cases of lip venous lake treated with intralesional injection of 1% polidocanol. METHOD: Two cases are reported, and literature is reviewed. RESULT: The lesions virtually disappeared, leaving an inconspicuous scar, with two sessions of sclerotherapy. Side effects were not observed. CONCLUSION: Sclerotherapy with polidocanol is effective in the treatment of lip venous lake and offers an alternative to conventional methods. 相似文献
34.
C Y Chai A M Lin C K Su S R Hu C Yuan L S Kao J S Kuo D S Goldstein 《Journal of the autonomic nervous system》1991,33(1):35-46
Effects of stimulation of brainstem sites on hemodynamics and plasma catecholamine levels were assessed in cats under chloralose-urethane anesthesia. Pressor areas of the dorsal medulla (DM) and ventrolateral medulla (VLM) and the depressor area of the paramedian reticular nucleus (PRN) were stimulated electrically using a monopolar electrode, or chemically using sodium glutamate microinjection. Plasma levels of norepinephrine (NE) and epinephrine (EPI) were measured in caval blood above the adrenal veins. Electrical stimulation of the DM and VLM produced increases in blood pressure and in plasma NE and EPI levels that were enhanced after acute vagotomies. The NE and EPI responses were attenuated after acute, bilateral adrenalectomies, confirming augmented adrenomedullary secretion, whereas the pressor responses were intact. Injection of sodium glutamate into the same pressor regions of the DM or VLM also produced pressor responses and elevated plasma catecholamine levels, indicating that the responses resulted from activation of neuronal perikarya. Stimulation of the PRN attenuated pressor and catecholamine responses during stimulation of the DM and VLM. The results indicate that pressor responses during stimulation of the DM and VLM are due at least partly to activation of perikarya in these regions, are associated with but not dependent on adrenomedullary activation, and are enhanced after vagotomy; and that neurons of the PRN exert inhibitory modulation of the pressor and adrenomedullary responses during stimulation of VLM and DM. 相似文献
35.
36.
37.
Periodic lateralized epileptiform discharges: etiology, clinical aspects, seizures, and evolution in 130 patients. 总被引:4,自引:0,他引:4
Irene García-Morales M Teresa García Lucia Galán-Dávila Carlos Gómez-Escalonilla Rosana Saiz-Díaz Antonio Martínez-Salio Pilar de la Pe?a Julian A Tejerina 《Journal of clinical neurophysiology》2002,19(2):172-177
The purpose of this study was to analyze the clinical aspects in 130 patients presenting periodic lateralized epileptiform discharges (PLEDs) in their EEG and to compare these results with those found in the literature. Etiology, neurologic deficit, seizure occurrence, and evolution were studied in each patient by historical review. The recordings were obtained on 8- or 16-channel EEGs with electrode placement according to the International 10-20 System. Recordings containing PLEDs were selected. PLEDs were defined as repetitive periodic, focal, or hemispheric epileptiform discharges (spikes, spike and waves, polyspikes, sharp waves) usually recurring every 1 to 2 seconds. The statistical study was carried out via the chi(2) test using the computer program SPSS. The main etiology found in this group of patients was stroke (61 of 130 patients). Other processes found were brain infections, tumors, hematomas, and several other entities grouped together as miscellaneous (anoxic encephalopathy, subarachnoid hemorrhage, craniocerebral trauma, Creutzfeldt-Jacob disease, migraine, multiple sclerosis, and aminophylline intoxication). Half of these patients (65 of 130) developed seizures, mostly partial motor seizures. No significant relation between etiology and seizures was found (chi(2) = 2.81, P = 0.4222). Seizures recurred in 14 of 130 patients during a follow-up of 14.5 months. PLEDs were not recorded in any EEG at the time of seizure recurrence. PLEDs constitute a distinctive but uncommon EEG phenomenon of repetitive, periodic, and stereotyped lateralized complexes. In agreement with the literature, PLEDs were associated with an acute process and occurred early during the course of the illness in all patients studied and were usually associated with structural lesions, with stroke being the main etiology. Traditionally, seizures occur with PLEDs but it is also accepted that they can exist in patients who never develop epileptic activity, either clinically or electrically, as demonstrated in 50% of the patients studied. No significant association between seizures and any etiology could be found. It was not demonstrated that the occurrence of seizures may influence the outcome in any way. 相似文献
38.
Marjolein Gysels Rhidian Hughes Fiona Aspinal Julia M Addington-Hall Irene J Higginson 《International journal for quality in health care》2004,16(5):375-381
OBJECTIVE: To investigate the opinions of stakeholders (service commissioners and providers) on how performance data should be presented, in order to develop effective feedback methods to facilitate the use of these data in decision making. DESIGN: A qualitative analysis of semi-structured face-to-face and telephone interviews. League tables and fictional box plots were presented as an illustrative guide. The themes covered in the interviews were the effectiveness of these two feedback formats, their positive and negative characteristics, and ideas for new and improved feedback mechanisms. PARTICIPANTS: Thirty-six stakeholders representing a range of clinical and non-clinical roles within palliative care and the wider health care system across a variety of statutory and non-statutory organizations from London and the West Midlands. RESULTS: Box plots were received more positively than league tables, and qualitative information was considered more appropriate than pictorial feedback. Conventional methods such as league tables and box plots were judged to lack essential information on which important decisions could be based, such as additional contextual information and the methodological assumptions of the instrument. Both feedback methods were considered useful as an impetus to further discussion. There was a consensus that feedback should be constructive and able to be adapted to the organizational realities in which UK health services function. CONCLUSION: Qualitative research was viewed as the right evidence for gaining an understanding of the quality of end of life care. Stakeholders highlighted the importance of the lay perspective, which requires approaches that illuminate the subjective meanings of patient experience. 相似文献
39.
40.
缺血性卒中或短暂性脑缺血发作患者的卒中预防指南 总被引:8,自引:0,他引:8
Ralph L.Sacco Robert Adams Grge Albers Mark J.ALBERTS Oscar Benavente Karen Furie Larry B.Goldstein Philip Gorelick Jonathan Halperin Robert Harbaugh S.Claiborne Johnston Irene Katzan Margaret Kelly-Hayes Edgar J.Kenton Michael Marks Lee H.Schwamm Thomas Tomsick 曹勇军 《中华脑血管病论坛》2006,4(1):21-66
这份新声明旨在为缺血性卒中或短暂性脑缺血发作存活者的缺血性卒中预防提供全面和及时的循证推荐,循证推荐包括对危险因素的控制,动脉粥样硬化性疾病的干预措施,心源性栓塞的抗栓治疗以及非心源性卒中抗血小板药的应用。另外,还为其他多种特殊情况下复发性卒中的预防提供了推荐、包括动脉夹层分离、卵圆孔未闭、高同型半胱氨酸血症、高凝状态、镰状细胞病、脑静脉窦血栓形成、女性卒中(特别是与妊娠和绝经后激素替代治疗相关卒中),脑出血后肮凝药的应用,以及该指南在高危人群中执行和应用的特殊措施。 相似文献