全文获取类型
收费全文 | 567635篇 |
免费 | 50245篇 |
国内免费 | 36445篇 |
专业分类
耳鼻咽喉 | 4567篇 |
儿科学 | 7354篇 |
妇产科学 | 8456篇 |
基础医学 | 63187篇 |
口腔科学 | 9563篇 |
临床医学 | 76986篇 |
内科学 | 81843篇 |
皮肤病学 | 6352篇 |
神经病学 | 28811篇 |
特种医学 | 20528篇 |
外国民族医学 | 290篇 |
外科学 | 54788篇 |
综合类 | 97068篇 |
现状与发展 | 120篇 |
一般理论 | 73篇 |
预防医学 | 39956篇 |
眼科学 | 15942篇 |
药学 | 60062篇 |
547篇 | |
中国医学 | 33091篇 |
肿瘤学 | 44741篇 |
出版年
2024年 | 1780篇 |
2023年 | 7776篇 |
2022年 | 20287篇 |
2021年 | 26165篇 |
2020年 | 20149篇 |
2019年 | 16931篇 |
2018年 | 17958篇 |
2017年 | 16772篇 |
2016年 | 15636篇 |
2015年 | 24029篇 |
2014年 | 30276篇 |
2013年 | 28264篇 |
2012年 | 41784篇 |
2011年 | 46561篇 |
2010年 | 30808篇 |
2009年 | 25051篇 |
2008年 | 31820篇 |
2007年 | 31736篇 |
2006年 | 30460篇 |
2005年 | 29562篇 |
2004年 | 20002篇 |
2003年 | 18747篇 |
2002年 | 15750篇 |
2001年 | 13859篇 |
2000年 | 13709篇 |
1999年 | 13977篇 |
1998年 | 8463篇 |
1997年 | 8251篇 |
1996年 | 6389篇 |
1995年 | 5945篇 |
1994年 | 5116篇 |
1993年 | 3339篇 |
1992年 | 4503篇 |
1991年 | 3951篇 |
1990年 | 3275篇 |
1989年 | 2879篇 |
1988年 | 2445篇 |
1987年 | 2237篇 |
1986年 | 1822篇 |
1985年 | 1380篇 |
1984年 | 830篇 |
1983年 | 632篇 |
1982年 | 359篇 |
1981年 | 359篇 |
1980年 | 300篇 |
1979年 | 389篇 |
1978年 | 213篇 |
1977年 | 164篇 |
1974年 | 158篇 |
1973年 | 132篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
背景与目的:原发性胆汁性肝硬化(PBC)伴系统性硬化症(SSc)的预后仍不十分清楚,该研究拟对其临床特点及预后进行评估。方法:从一个含580例患者的PBC数据库中选出43例PBC伴SSc患者,同时为每例PBC—SSc患者匹配2例单纯PBC患者作为对照,监测初次就医时的血清胆红素浓度。结果:局限皮肤型SSc者40例(93%)。诊断PBC时的中位年龄为49.7岁,胆红素浓度为17μmol/L,白蛋白水平为40.5g/L。24例(56%)患者于SSc后在中值为4.9年发生PBC。配对患者诊断PBC时的中位年龄为53.2岁、胆红素浓度为12μmol/L、白蛋白水平为41g/L。两组患者中位随访时间相似:PBC—SSc组为3.16年,单纯PBC组为4.8年。PBC—SSc患者南于较少接受移植手术(HR0.068;P:0.006),在校正性别、年龄、胆红素对数及碱性磷酸酶等因素后,其移植术或死亡风险(HR0.116;P=0.01)均明显降低,同时胆红素上升的比例亦较低(P=0.04)。 相似文献
992.
Jonas Bergstrm Mahmood Ahmed Jian Li Tashfeen Ahmad Andris Kreicbergs Mariana Spetea 《Journal of orthopaedic research》2006,24(6):1193-1199
Using immunohistochemical and biochemical techniques, the occurrence of endogenous opioid peptides and their receptors in normal rat bone and joint tissues was investigated. Opioid receptors were detected, quantified, and characterized in homogenates from capsule/synovium and periosteum using radioligand binding assays. Receptor binding of the nonselective opioid [3H]naloxone to tissue homogenates was stereospecific and saturable, showing similar characteristics to that of brain tissue, although with lower binding capacities. By immunohistochemistry, the neuronal occurrence of four different enkephalins was demonstrated in synovium, bone marrow, periosteum, and juxta-articular bone, whereas no neuronal dynorphin immunoreactivity was detected. Double-staining studies disclosed that enkephalins coexisted with substance P in primary afferent fibers. The applied techniques can be used to assess changes in the distribution of endogenous opioids and their receptors in joint tissues in conditions associated with pain and inflammation. The endogenous opioid system now demonstrated might be targeted and exploited therapeutically to obtain peripheral control of symptoms in joint disorders. 相似文献
993.
BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injury, the abnormal functions of brain are varied, and they have very strong plasticity and are corrected easily.
OBJECTIVE: To observe the changes of neuronal morphology in hippocampal CA1 region and memory function in newborn rats with hypoxic-ischemic encephalopathy(HIE) from ischemia 6 hours to adult.
DESIGN: Completely randomized grouping, controlled experiment.
SETTING: Taian Health Center for Women and Children; Taishan Medical College.
MATERIALS: Altogether 120 seven-day-old Wistar rats, of clean grade, were provided by the Experimental Animal Center, Shandong University of Traditional Chinese Medicine. Synaptophysin (SYN) polyclonal antibody was provided by Maixin Biological Company, Fuzhou.
METHODS: This experiment was carried out in the Laboratory of Morphology, Taishan Medical College between October 2000 and December 2003. ① The newborn rats were randomly divided into 2 groups: model group and control group, 60 rats in each group. Five rats were chosen from each group at postoperative 6 hours, 24 hours, 72 hours, 7 days, 2 weeks and 3 weeks separately for immunohistochemical staining. Fifteen newborn rats were chosen from each group at postoperative 4 weeks and 2 months separately for testing memory ability (After test, 5 rats from each group were sacrificed and used for immunohistochemical staining)② The right common carotid artery of newborn rats of model group was ligated under the anesthetized status. After two hours of incubation, the rats were placed for 2 hours in a container filled with nitrogen oxygen atmosphere containing 0.08 volume fraction of oxygen, thus, HIE models were created; As for the newborn rats in the control group, only blood vessels were isolated, and they were not ligated and hypoxia-treated. ③ Thalamencephal tissue sections of newborn rats of two groups were performed DAB developing and haematoxylin slight staining. Cells with normal nucleous in 250 μm-long granular layer which started from hippocampal CA1 region were counted with image analysis system under high-fold optical microscope (×600), and the thickness of granular layer was measured. The absorbance (A) of positive reactant of SYN in immunohistochemically-stained CA1 region was measured. Learning and memory ability were measured with step through test 3 times successively. ④ t test and paired t test were used for comparing intergroup and intragroup difference of measurement data respectively, and Chi-square for comparing the difference of enumeration data.
MAIN OUTCOME MEASURES: Comparison of cytological changes in hippocampal CA1 region and memory ability at different postoperative time points between two groups.
RESULTS: Totally 120 newborn rats were involved in the result analysis. ① Cell morphological changes in hippocampal CA1 region: In the control group, with aging, perikaryon, nucleus and nucleolus in cortex of parietal lobe were significantly increased, Nissl body was compacted, the amount of neurons was declined, but the A of SYN positive reactant was relatively increased. In the model group, at postoperative each time point, neurons were seriously shrunk and dark-stained, nucleus was contracted, chromatin was condensed, nucleolus was unclear, even cells disappeared, especially the cells in 6 hours and 24 hours groups. The amount of neurons with normal morphology in hippocampal CA1 region and granular layer thickness in the model group at postoperative each time point were significantly less or smaller than those in the control group at postoperative 6 hours respectively (t =3.002-1.254, P < 0.01). The A value of SYN positive reactant at postoperative 2, 3 and 4 weeks was significantly higher than that at previous time point (t =2.011-2.716,P < 0.05-0.01). ② Test results of learning and memory ability: In the first test, there was no significant difference in the ratio of rats which kept memory ability between two groups (P > 0.05); In the third test, the ratio of rats which kept memory ability in the model group was significantly lower than that in the control group at postoperative 4 weeks and 2 months[53%(8/15),100%(15/15);60%(9/15),93%(14/15),χ 2=2.863,2.901,P < 0.01].
CONCLUSION: The destroyed hippocampal structure induces the decrease of learning and memory ability of developmental rats. Early interference can increase the quality of neurons and also promote functional development of the nervous system. 相似文献
994.
995.
996.
目的探讨LEEP刀治疗与护理相结合在治疗宫颈疾病中的作用。方法选择应用LEEP刀治疗与红外光治疗两组患者各60例。比较其疗效和护理作用。结果LEEP刀治疗比红外光治疗宫颈疾病效果要好。结论LEEP刀治疗与护理相结合对宫颈疾病的治疗值得推广应用。 相似文献
997.
Einosuke Mizuta Toshihiro Hamada Shin-ichi Taniguchi Masaki Shimoyama Takahiro Nawada Junichiro Miake Yasuhiro Kaetsu Li Peili Kiyosuke Ishiguro Shingo Ishiguro Osamu Igawa Chiaki Shigemasa Ichiro Hisatome 《Hypertension research》2006,29(8):635-638
We report the case of a 67-year-old woman with severe hypertension caused by an extra-adrenal pheochromocytoma. The tumor was detected by 131I metaiodobenzylguanidine scintigraphy and it was found to be small (2 cm ?) by enhanced CT. After the extirpation of the tumor, the blood pressure of the patient immediately normalized. It should be taken into account that a small extra-adrenal pheochromocytoma can be one of the causes of secondary hypertension in elderly patients. Since small extra-adrenal pheochromocytomas are difficult to detect, it is also important to perform suitable examinations to establish the diagnosis. Furthermore, we emphasize the importance of an accurate diagnosis in elderly patients with pheochromocytoma, for they often have less symptomatology and more severe cardiovascular complications due to refractory hypertension than younger patients. 相似文献
998.
对1986年-1990年《江西医学院学报》的引文进行了数理统计与分析,定量描述其引文的类型,文种,时序以及在被引期刊中的分布。测定了该刊引用文献的半衰期与核心期刊,并对论著及著者分布作了分析。 相似文献
999.
1000.
本文对极易污染活螨的中药大蜜丸,在应用分离法的基础上,根据螨怕光、怕热的习性,适当调整光照,周围严格避光,达到分离活螨的目的. 相似文献