全文获取类型
收费全文 | 21131篇 |
免费 | 1016篇 |
国内免费 | 577篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 214篇 |
妇产科学 | 451篇 |
基础医学 | 2600篇 |
口腔科学 | 326篇 |
临床医学 | 1416篇 |
内科学 | 2639篇 |
皮肤病学 | 424篇 |
神经病学 | 1238篇 |
特种医学 | 357篇 |
外国民族医学 | 7篇 |
外科学 | 1115篇 |
综合类 | 3069篇 |
现状与发展 | 2篇 |
预防医学 | 1001篇 |
眼科学 | 264篇 |
药学 | 5128篇 |
11篇 | |
中国医学 | 1532篇 |
肿瘤学 | 879篇 |
出版年
2023年 | 242篇 |
2022年 | 373篇 |
2021年 | 741篇 |
2020年 | 763篇 |
2019年 | 564篇 |
2018年 | 498篇 |
2017年 | 746篇 |
2016年 | 795篇 |
2015年 | 720篇 |
2014年 | 1686篇 |
2013年 | 2479篇 |
2012年 | 2085篇 |
2011年 | 1914篇 |
2010年 | 1423篇 |
2009年 | 1187篇 |
2008年 | 1045篇 |
2007年 | 726篇 |
2006年 | 626篇 |
2005年 | 553篇 |
2004年 | 477篇 |
2003年 | 349篇 |
2002年 | 286篇 |
2001年 | 180篇 |
2000年 | 139篇 |
1999年 | 131篇 |
1998年 | 146篇 |
1997年 | 112篇 |
1996年 | 127篇 |
1995年 | 97篇 |
1994年 | 78篇 |
1993年 | 75篇 |
1992年 | 49篇 |
1991年 | 37篇 |
1990年 | 52篇 |
1989年 | 41篇 |
1988年 | 49篇 |
1987年 | 37篇 |
1986年 | 33篇 |
1985年 | 143篇 |
1984年 | 143篇 |
1983年 | 146篇 |
1982年 | 145篇 |
1981年 | 108篇 |
1980年 | 92篇 |
1979年 | 63篇 |
1978年 | 54篇 |
1977年 | 35篇 |
1976年 | 31篇 |
1975年 | 29篇 |
1973年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
41.
42.
To evaluate the effect of interleukin-8 (IL8) on glomerular basement membrane (GBM) sulfated compounds and albuminuria, we
infused IL8 in 1% bovine serum albumin (BSA) for 5 days into the left renal artery of Holtzman male rats at the rate of 10
μl/h using an osmotic pump. Control rats received 1% BSA. A significant increase in urinary albumin/creatinine ratio was seen
on the last day of IL8 infusion (0.38±0.11, mean ± SEM) when compared with albumin/creatinine ratio prior to infusion (0.19±0.04,
P = 0.04). No significant differences in urinary albumin excretion prior to and after infusion of 1% BSA were observed. On
the last day of infusion, rats were injected with 35sulfate (1.0 mCi/200 g body weight) intraperitoneally and killed after 8 h. Glomeruli were isolated and GBM obtained. After
5 days of IL8 administration, there was a significant increase in 35sulfate uptake by GBM of the infused kidney (76±10 cpm/dry glomerular weight, mean ± SEM) compared with the uptake seen in
the contralateral kidney (53±9, P = 0.05). The in vivo infusion of IL8 increased the 35sulfate uptake by GBM and augmented the urinary albumin/creatinine ratio, suggesting that IL8 may induce albuminuria by altering
the metabolism of the GBM sulfated compounds. This hypothesis needs to be confirmed by studies on glomerular charge selectivity
and GBM anionic sites during the course of the infusion. Moreover, the persistence of the effect needs to be evaluated by
prolonging the infusion for more than 5 days.
Received June 3, 1996; received in revised form and accepted October 18, 1996 相似文献
43.
44.
Seishiro Hirano Takako Asami Naomi Kodama Kazuo T. Suzuki 《Archives of toxicology》1994,68(7):444-449
In a preceding study, we reported that the numbers of macrophages and polymorphonuclear leukocytes (PMN) were increased in
bronchoalveolar lavage fluid (BALF) following the intratracheal instillation of nickel sulfate (NiSO4) in rats. In the present study, BALF chemotactic activities for both macrophages and PMN were measured to investigate if
the increases of these inflammatory cells in BALF depend on increases in chemotactic activities in epithelial lining fluid
(ELF) of the lung. Both the number of PMN and the PMN chemotactic activity peaked at 2 days post-instillation and they were
significantly correlated. However, the PMN chemotactic activity was inversely correlated with concentration of leukotriene
B4 (LTB4), a well-known chemotaxin. Although PMN were not observed in control BALF, LTB4 concentration in the control ELF (ca. 5×10–7 M) was estimated to have a potential to attract PMN chemotactically through a membrane in in vitro migration assay. These
results suggest that the presence of LTB4 in ELF itself does not trigger transpulmonary PMN infiltration. The rat BALF were fractionated by high performance liquid
chromatography (HPLC), and PMN chemotactic activity of each fraction was measured. The elution profiles of PMN chemotactic
activity showed that there were at least two different chemotaxins in BALF obtained from the NiSO4-exposed rats. Macrophage chemotactic activity in BALF also peaked at 2 days post-instillation. However, the number of macrophages
was not significantly correlated with the chemotactic activity for macrophage in BALF. The HPLC study showed that the macrophage
chemotactic substance in the BALF obtained from NiSO4-exposed rats was different from complement fragment (C5a) and its MW was estimated to be 10 – 12 kD.
Received: 1 December 1993/Accepted: 16 March 1994 相似文献
45.
Axonal neuropathy in a patient with monoclonal IgM kappa reactive with Schmidt-Lantermann incisures 总被引:1,自引:0,他引:1
Angelo Quattrini Raffaello Nemni Raffaella Fazio Sandro Iannaccone Isabella Lorenzetti Franco Grassi Nicola Canal 《Journal of neuroimmunology》1991,33(1):73-79
We report a patient with a progressive, predominantly sensory neuropathy and a IgM kappa M-protein that binds to Schmidt-Lantermann incisures. A sural nerve biopsy showed primary axonal damage and IgM deposits at Schmidt-Lantermann incisures were seen by direct immunoperoxidase. Serum from the patient injected into rat sciatic nerve reacts with the incisures as with those in the patient's nerve. The IgM kappa M-protein reacts with chondroitin sulfate C and binds to a broad nerve protein band with a mobility of between 170 and 118 kDa. Peripheral neuropathy may be related to the M-protein, which had immunocytochemical reactivity not previously described for patients with polyneuropathy and IgM monoclonal gammopathy. 相似文献
46.
多糖硫酸脂(PSS)治疗缺血性脑血管病临床观察和实验室研究 总被引:1,自引:0,他引:1
应用PSS治疗270例缺血性脑血管病并进行了临床、实验室以及动物试验的观察.总有效率为92.27%;显效率65.24%,与对照组相比较有显著性差异(P<0.005).实验室观察发现PSS有显著的抗凝血、降低血粘度,降低血脂及血管扩张作用.动物实验也说明了这一点. 相似文献
47.
Summary A new gas-liquid chromatographic (GLC) determination of cholesterol sulfate (CS) and dehydroepiandrosterone sulfate (DHEAS) for a biochemical diagnosis of recessive X-linked ichthyosis (RXLI) is described. Although the GLC method for determination of CS is known to be more sensitive than the thin layer chromatographic (TLC) method, the former method has not been widely employed because of its complicated pre-purification steps. The present method allows us to measure the serum levels of CS and DHEAS without tedious purification steps such as multiple conventional column chromatography and preparative thin layer chromatography. Sulfated steroids are rapidly purified with a commercially available mini disposable cyclohexylsilane-bonded phase (CH) column, CH BOND ELUT, and the purified steroids after desulfation are converted to water-resistant tert-butyldimethylsilyl ether derivatives for the GLC analysis on dual 2 m glass columns packed with 2% XE-60 on Chromosorb W.By the present method, serum CS concentrations in RXLI patients were shown to be about 10 times higher than those in patients with ichthyosis vulgaris, carriers of RXLI, and healthy subjects. This method is more suitable not only for a biochemical diagnosis of RXLI but also for studies on the metabolism of sulfated steroids than the previous time-consuming GLC methods. 相似文献
48.
从中间体(4)出发,经醛(5),与鏻叶立德(3)或2-酮-4-苯丁烷磷酸酯(11)钠缩合成(6),再钠硼氢还原得3′α-醇(7A)及其差向异构体(7B),经硅胶柱色谱分开,分别经二异丁基铝氢还原,与溴化5-三苯鏻戊酸之Wittig试剂缩合,得17-苯-18,19,20-失三碳前列腺素F2α(9A)及其15-差向异构体(9B),再用重氮甲烷甲酯化,分别得相应的17-苯-18,19,20-失三碳前列腺素F2α甲酯(10A)及其15-差向异构体(10B)。 相似文献
49.
尼莫地平片溶出度的研究 总被引:3,自引:0,他引:3
采用转篮法对尼莫地平国产市售片,进口片和自制片在不同介质、不同转速和PH条件下的溶出度进行测试。结果表明,介质对尼莫地平溶出具有很大的影响,而最佳测定方法是以0.1%的十二烷基硫酸钠水溶液为介质,转速150r/min。 相似文献
50.
荞麦花粉抗贫血作用的实验研究 总被引:1,自引:0,他引:1
用荞麦花粉的水提取液进行了抗大白鼠缺铁性贫血的研究,结果表明:荞麦花粉具有和硫酸亚铁相似的抗缺铁性贫血作用.饮用荞麦花粉提取液35d的大白鼠,生长发育良好,主要脏器未见损害.该研究为荞麦花粉的开发利用提供了实验依据. 相似文献