全文获取类型
收费全文 | 42650篇 |
免费 | 3564篇 |
国内免费 | 1065篇 |
专业分类
耳鼻咽喉 | 444篇 |
儿科学 | 1144篇 |
妇产科学 | 804篇 |
基础医学 | 6483篇 |
口腔科学 | 1122篇 |
临床医学 | 4059篇 |
内科学 | 8278篇 |
皮肤病学 | 749篇 |
神经病学 | 3730篇 |
特种医学 | 1459篇 |
外国民族医学 | 4篇 |
外科学 | 5249篇 |
综合类 | 2526篇 |
一般理论 | 30篇 |
预防医学 | 3060篇 |
眼科学 | 776篇 |
药学 | 3621篇 |
中国医学 | 404篇 |
肿瘤学 | 3337篇 |
出版年
2023年 | 208篇 |
2022年 | 391篇 |
2021年 | 710篇 |
2020年 | 411篇 |
2019年 | 623篇 |
2018年 | 937篇 |
2017年 | 721篇 |
2016年 | 777篇 |
2015年 | 875篇 |
2014年 | 1117篇 |
2013年 | 1474篇 |
2012年 | 2050篇 |
2011年 | 2087篇 |
2010年 | 1248篇 |
2009年 | 1084篇 |
2008年 | 1885篇 |
2007年 | 1988篇 |
2006年 | 1795篇 |
2005年 | 1638篇 |
2004年 | 1529篇 |
2003年 | 1348篇 |
2002年 | 1207篇 |
2001年 | 2503篇 |
2000年 | 2418篇 |
1999年 | 1993篇 |
1998年 | 825篇 |
1997年 | 569篇 |
1996年 | 427篇 |
1995年 | 376篇 |
1994年 | 334篇 |
1993年 | 301篇 |
1992年 | 1160篇 |
1991年 | 1042篇 |
1990年 | 943篇 |
1989年 | 1029篇 |
1988年 | 930篇 |
1987年 | 865篇 |
1986年 | 805篇 |
1985年 | 732篇 |
1984年 | 463篇 |
1983年 | 393篇 |
1982年 | 242篇 |
1981年 | 199篇 |
1980年 | 167篇 |
1979年 | 276篇 |
1978年 | 149篇 |
1977年 | 146篇 |
1975年 | 129篇 |
1974年 | 152篇 |
1973年 | 140篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
344 cases of Heart-Qi Deficiency Syndrome (HQDS) including 19 Kinds of disease were observed to explore the rule of differentiation of symptoms and signs for HQDS. The results showed that the common symptoms of HQDS were weakness, shortness of breath, and palpitation, etc. According to with or without complicated cardiovascular diseases, the patients were divided into two groups: group A with cardiovascular diseases, group B without that. In group A, the symptoms and signs of HQDS were the most frequent and early clinical manifestations, the associated symptoms and signs were blood stasis and attack of water-evil, etc. In group B, in whom often associated with nervous and emotional symptoms such as insomnia, dreamfulness, and amnesia, etc., which was due to the disturbance of emotional activities of heart. In order to avoid diagnostic confusion, the authors suggest that the HQDS patients with cardiovascular diseases would be diagnosed as HQDS; on the other hand, the HQDS patients without cardiovascular diseases would be diagnosed as disturbance of emotional activities of heart. 相似文献
103.
The authors report a case of supraventricular tachyarrhythmia complicated by severe myocardial ischemia after IV injection of Atropine in a 37 years old woman, without known coronary artery disease. She had an ECG with sinusal bradycardia (40/min) and she was on the waiting list for to be submitted to surgical intervention on the lumbar spine. 相似文献
104.
This study shows that arterial smooth muscle cells (SMC) isolated from rats receiving atherogenic doses of the lipid emulsion, Lipofundin-S, alter their in vitro growth properties. Compared to cells from control animals, SMC isolated from Lipofundin-S-infused rats show a reduction in both saturation density and response to increasing serum concentrations, without a change in the baseline proliferation. Also, SMC isolated from lipid-treated animals and grown for five days in the presence of 30, 150, or 300 pg/ml estradiol show a 30% increase in growth vs. cells from controls. Epinephrine at 1 microM stimulates growth in SMC from control rats, while causing no growth enhancement over five days in cells from lipid-infused animals. Thus, atherogenic infusions of Lipofundin-S into rats cause phenotypic changes in arterial SMC which can be passed to successive cell generations in vitro. 相似文献
105.
Transitional mucosa adjacent to colorectal cancers is essentially characterized by an excess of sialomucins at the expense of the normally predominant sulphomucins in epithelial cells lining the intestinal crypts which presents the early stage of oncogenic transformation of colorectal epithelium. The presence or absence of sialomucins at the resection margins was studied histochemically using the high iron diamine-alcian blue(HID-AB) stain in 64 rectal cancer patients in Dukes' B stage who underwent curative anterior resection. The correlation was revealed between the presence of sialomucins at the resection margins and subsequent development of local tumour recurrence. Fourteen of 27 patients (51.9%) with sialomucins predominant pattern at either resection margin developed local recurrence compared with 4 of 37 patients (10.8%) with sulphomucins predominant pattern (P less than 0.001). It is suggested that determination of the transitional mucosa around anastomosis in patients treated for the rectal carcinoma by anterior resection appears to identify those with a higher risk of local recurrence. 相似文献
106.
Antibodies to glutamic acid decarboxylase discriminate major types of diabetes mellitus. 总被引:13,自引:0,他引:13
Insulin-dependent diabetes mellitus (IDDM) is marked by circulating antibodies to a 64,000-M(r) islet cell antigen identified as glutamic acid decarboxylase (GAD). We describe a radioimmunoprecipitation assay with GAD isolated from pig brain. The sera tested were from 80 patients with IDDM including 26 with disease of recent onset and 54 with disease of longer duration (3-42 yr), 20 with non-insulin-dependent diabetes mellitus (NIDDM), and 55 nondiabetic subjects. Conventional assays for islet cell cytoplasmic antibodies were performed concurrently. The level of antibody in serum was expressed in units based on percentage reactivity of a standard reference serum. The frequency of antibody to GAD in IDDM was 69% in short-duration cases and 59% in long-duration cases. The latter was substantially higher than the frequency of islet cell cytoplasmic antibody. Antibodies to GAD were elevated (means +/- 3 SD) in 5% NIDDM cases and in none of the nondiabetic subjects. A simple laboratory test with a defined autoantigen has substantial implications for population screening and early diagnosis of IDDM and for better understanding of its pathogenesis. 相似文献
107.
Effects of Cistanche deserticola on immune function in mice 总被引:2,自引:0,他引:2
108.
Neuropeptide Y action in the rat hippocampal slice: site and mechanism of presynaptic inhibition 总被引:10,自引:0,他引:10
Neuropeptide Y (NPY), the most abundant peptide in mammalian CNS, has been shown to inhibit excitatory neurotransmission presynaptically at the stratum radiatum-CA1 synapse in the in vitro rat hippocampal slice. We examined the site and mechanism of this inhibition in a series of in vitro intra- and extracellular recordings in areas CA1 and CA3, the source of much of the excitatory synaptic input to the CA1 neurons. NPY's inhibitory action at the stratum radiatum-CA1 synapse was unaffected by high concentrations of the antagonists bicuculline, theophylline, or atropine, suggesting that it does not act by stimulating the release of the known presynaptic inhibitory transmitters GABA, adenosine, or ACh, respectively. Bath application of 10(-6) NPY, a concentration that strongly inhibited the stratum radiatum-CA1 synapse had no effect on CA3 neuron resting potential, input resistance or action potential amplitude, threshold, or duration. NPY also does not alter the amplitude or duration of the prolonged CA3 action potentials evoked in the presence of TTX, tetraethyl-ammonium, and elevated external Ca2+ or those evoked in the presence of TTX and Ba2+ ions. NPY therefore does not alter the passive or active properties of the somata of the presynaptic CA3 neurons. Neither the afferent fiber volley of the Schaffer collaterals in stratum radiatum of area CA1 nor the excitability of the CA3 terminals in CA1 was affected by NPY application. However, application of the transient K+ current blocker, 4-aminopyridine (4-AP) at concentrations of 10 and 50 microM, completely abolished the action of 10(-6) M NPY on the stratum radiatum-CA1 excitatory synaptic potentials. This action of 4-AP could be reversed by reducing extracellular Ca2+ concentrations from a control level of 1.5 to 0.7 mM (in 10 microM 4-AP) and to 0.5 mM (in 50 microM 4-AP). The evidence suggests that NPY inhibits excitatory synaptic transmission at the Schaffer collateral-CA1 synapse by acting directly at the terminal to reduce a Ca2+ influx. 相似文献
109.
U S Page J E Okies L Q Colburn J C Bigelow N W Salomon A H Krause 《The Journal of thoracic and cardiovascular surgery》1986,92(5):847-852
The incidence of prior percutaneous transluminal coronary angioplasty in surgical cases is nearly doubling yearly. In 1985, 11.4% of our bypass patients had one or more prior angioplasties. One hundred thirty-five patients with prior angioplasty are compared to 2,205 patients without angioplasty undergoing surgical revascularization. The mortality is 3.2 times higher in the angioplasty patients than in the control patients and the perioperative infarction rate is 2.5 times higher. Forty-four patients were taken directly to the operating room from the catheterization laboratory, 50 were operated on within 10 days, and 41 underwent operation more than 10 days after angioplasty. All of these late failures were of the lesion previously dilated. The infarction rate was less in patients taken immediately to the operating room on an emergency basis than in those whose operation was delayed up to 10 days (30% versus 70%). All patients who died had angioplasty of the anterior descending coronary artery. Angioplasty of this artery increases operative mortality should surgical treatment become necessary acutely. Patients should be informed before angioplasty of the increased surgical risks after a failed angioplasty procedure. 相似文献
110.