全文获取类型
收费全文 | 386179篇 |
免费 | 35611篇 |
国内免费 | 26903篇 |
专业分类
耳鼻咽喉 | 2928篇 |
儿科学 | 5004篇 |
妇产科学 | 4384篇 |
基础医学 | 42444篇 |
口腔科学 | 6396篇 |
临床医学 | 54486篇 |
内科学 | 52490篇 |
皮肤病学 | 4212篇 |
神经病学 | 18779篇 |
特种医学 | 14255篇 |
外国民族医学 | 230篇 |
外科学 | 34352篇 |
综合类 | 71792篇 |
现状与发展 | 87篇 |
一般理论 | 33篇 |
预防医学 | 28235篇 |
眼科学 | 10950篇 |
药学 | 41841篇 |
445篇 | |
中国医学 | 25065篇 |
肿瘤学 | 30285篇 |
出版年
2024年 | 1308篇 |
2023年 | 5611篇 |
2022年 | 14798篇 |
2021年 | 18882篇 |
2020年 | 14801篇 |
2019年 | 12117篇 |
2018年 | 12543篇 |
2017年 | 11975篇 |
2016年 | 11078篇 |
2015年 | 17294篇 |
2014年 | 21536篇 |
2013年 | 19561篇 |
2012年 | 29127篇 |
2011年 | 32737篇 |
2010年 | 22042篇 |
2009年 | 17991篇 |
2008年 | 22025篇 |
2007年 | 21708篇 |
2006年 | 20751篇 |
2005年 | 19827篇 |
2004年 | 13105篇 |
2003年 | 12646篇 |
2002年 | 10374篇 |
2001年 | 8829篇 |
2000年 | 8647篇 |
1999年 | 8762篇 |
1998年 | 5526篇 |
1997年 | 5309篇 |
1996年 | 4125篇 |
1995年 | 3889篇 |
1994年 | 3252篇 |
1993年 | 2112篇 |
1992年 | 2547篇 |
1991年 | 2204篇 |
1990年 | 1858篇 |
1989年 | 1621篇 |
1988年 | 1338篇 |
1987年 | 1242篇 |
1986年 | 1002篇 |
1985年 | 722篇 |
1984年 | 391篇 |
1983年 | 286篇 |
1982年 | 146篇 |
1981年 | 175篇 |
1980年 | 118篇 |
1979年 | 162篇 |
1978年 | 76篇 |
1977年 | 56篇 |
1974年 | 43篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Principles for managing penetrating craniocerebral injuries caused by firearm missiles 总被引:1,自引:0,他引:1
X Zhang S Y Yi W P Liu Z W Zhang L G Wang A M Li 《Journal of clinical neuroscience》1996,3(3):229-233
Penetrating craniocerebral firearm injuries remain one of the most lethal causes of all trauma and are common both in war or peace time. Data were reviewed for 4140 severely head-injured patients (Glasgow Coma Scale (GCS) scores 3-8) treated at Xi-Jing Hospital between 1973 and 1993; 51 of these patients had acute penetrating craniocerebral injuries caused by firearm missiles. These patients consisted of 46 males (90.2%) and 5 females (9.8%) ranging in age from 3 months to 48 years (median 22.4 years). The lesion types included 2 tangential wounds, 37 tubular wounds and 12 through-and-through wounds. All cases were urgent with the patients in severe and unstable states. After emergency treatment and operation, 5 cases died (9.8%). Follow up studies at three months showed that 23 cases (45.1%) had made a good recovery. Moderate disability, severe disability and vegetative states in this series were 29.4%, 13.7% and 2.0% respectively. Long term follow up studies indicated that 32 were able to resume their occupation. The principles for managing penetrating craniocerebral firearm injuries and suggestions for operation are discussed. 相似文献
92.
Da-Nian Zhu, Long-Mei Xue, Peng Li. Effect of central muscarine receptor blockade. with DKJ-21 on the blood pressure and heart rote in stress-induced hypertensive rats.
The experiments were performed on Wistar or Sprague-Dawley rats of both sexes divided at random into stress and control groups. The rats in the stress groups were put into cages and subjected to electric foot-shocks and noises for 9-15 days, which caused an increase in blood pressure (BP) and heart rate (HR). In hypertensive rats DKJ-21 (4mg/lml) was injected intravenously (i.v.), and 0.5-1.0h after administration the BP and HR dropped from the high level to normotensive level. In normotensive rats, however, administration of DKJ-21 had no effect on BP or HR. In separate groups of normotensive rats, pretreatment of DKJ-21 (4 mg/l ml, i.v.) blocked the pressor and tachycardiac effect induced by microinjection of physostigmine (0.4μg/0.1 /μl/site), corticosterone (40μg/0.1μl/site) or aldosterone (40 μg/0.1 μl/site) into the rostral ventrolateral medulla (rVLM). Furthermore, DKJ-21 also attenuated the enhancement of the pressor response to stimulation of the defense area in the midbrain, which was induced by microinjection of drugs (mentioned above) into the rVLM. These results indicate that i.v. DKJ-21 can selectively block the muscarinic receptors in the rVLM in stress-induced hypertensive rats, which suggests that abnormal enhancement of cholinergic mechanism in the rVLM may be related to hypertensive effects of corticoids in this area. 相似文献
The experiments were performed on Wistar or Sprague-Dawley rats of both sexes divided at random into stress and control groups. The rats in the stress groups were put into cages and subjected to electric foot-shocks and noises for 9-15 days, which caused an increase in blood pressure (BP) and heart rate (HR). In hypertensive rats DKJ-21 (4mg/lml) was injected intravenously (i.v.), and 0.5-1.0h after administration the BP and HR dropped from the high level to normotensive level. In normotensive rats, however, administration of DKJ-21 had no effect on BP or HR. In separate groups of normotensive rats, pretreatment of DKJ-21 (4 mg/l ml, i.v.) blocked the pressor and tachycardiac effect induced by microinjection of physostigmine (0.4μg/0.1 /μl/site), corticosterone (40μg/0.1μl/site) or aldosterone (40 μg/0.1 μl/site) into the rostral ventrolateral medulla (rVLM). Furthermore, DKJ-21 also attenuated the enhancement of the pressor response to stimulation of the defense area in the midbrain, which was induced by microinjection of drugs (mentioned above) into the rVLM. These results indicate that i.v. DKJ-21 can selectively block the muscarinic receptors in the rVLM in stress-induced hypertensive rats, which suggests that abnormal enhancement of cholinergic mechanism in the rVLM may be related to hypertensive effects of corticoids in this area. 相似文献
93.
Eleven (3%) of 340 patients with hepatocellular carcinoma (HCC) presented with obstructive jaundice. The tumor extensively infiltrated the major bile ducts in eight patients. Jaundice was relieved by endoscopic endoprosthesis in four patients, nasobiliary drainage in two patients, percutaneous transhepatic stenting in one patient, and surgical intubation in one patient. The survival interval of these eight patients (mean +/- SD) was 35 +/- 20 days. Three patients had tumor fragments in the common bile ducts. In two patients, major hepatic resection was done after initial tube decomposition of the biliary system. One patient remained tumor-free on follow-up at 24 months, and the other patient had recurrent tumor detected on follow-up at 17 months after surgery. The tumor was irresectable in the third patient. Multiple surgical and endoscopic procedures kept the bile duct patent for 17 months before the patient died of the disease. Not all patients who present with obstructive jaundice due to HCC are terminally ill. With proper management, good palliation and occasional cure are possible. 相似文献
94.
应用神经组织化学技术观察了兔角膜NA能神经及AchE阳性神经在角膜损伤后的再生,证实术后1月,两种神经均有再生轴突进入植片;术后3月可见交界区和植床内神经密度明显增加;同时,对术后两种神经再生的功能意义进行了讨论。 相似文献
95.
96.
97.
X F Sun H Zhang X C Wu Y M Han G Q Hou M S Xian 《Acta oncologica (Stockholm, Sweden)》1992,31(1):37-40
The microcirculatory architecture of normal tissue, transitional mucosa and adenocarcinoma of the human colon was investigated with microvascular corrosion casting (MVCC) combined with scanning electron microscopy (SEM). The study showed that the capillaries within the normal mucosa were arranged in a regular hexagonal pattern around the mucosal glands and that the microvessels of transitional mucosa mostly had lost the typical hexagonal pattern and become slightly wider in diameter. The microvessels in the tumor periphery were increased in number and disorganized, and presented large variation in morphology with claw-like formations, widened sinuses, diverticula and appendixoid patterns. Microvessels were lacking in the central areas of tumors. These morphological alterations may serve as additional indicators of tumor development. 相似文献
98.
99.
100.
Three kinds of lectins (UEA-I, ConA, PNA) were used to study normal, dysplastic, neoplastic nasopharyngeal epithelium by lectin affinitive histochemical method. UEA-I (ulex europeus agglutinin-I) displayed membrane distribution in normal squamous epithelium, but most of nasopharyngeal carcinoma cells were negative. Notably, severe dysplastic epithelium (precancerous lesion) exhibited a strong membranous and cytoplasmic affinity, which contrasted sharply with the normal epithelium and carcinoma cells. The statistically significant difference in the content and distribution of lectin UEA-I in these three groups suggest that UEA-I is a hopeful marker for diagnosing precancerous lesion of the nasopharynx. However, PNA and ConA are of less diagnostic value.
相似文献