全文获取类型
收费全文 | 171150篇 |
免费 | 6664篇 |
国内免费 | 376篇 |
专业分类
耳鼻咽喉 | 2273篇 |
儿科学 | 4874篇 |
妇产科学 | 3968篇 |
基础医学 | 24753篇 |
口腔科学 | 6077篇 |
临床医学 | 9742篇 |
内科学 | 37598篇 |
皮肤病学 | 4610篇 |
神经病学 | 13785篇 |
特种医学 | 4246篇 |
外国民族医学 | 1篇 |
外科学 | 19712篇 |
综合类 | 789篇 |
一般理论 | 25篇 |
预防医学 | 20367篇 |
眼科学 | 4388篇 |
药学 | 13326篇 |
中国医学 | 723篇 |
肿瘤学 | 6933篇 |
出版年
2023年 | 882篇 |
2022年 | 690篇 |
2021年 | 2692篇 |
2020年 | 1533篇 |
2019年 | 3046篇 |
2018年 | 5243篇 |
2017年 | 3277篇 |
2016年 | 3263篇 |
2015年 | 3640篇 |
2014年 | 4036篇 |
2013年 | 6124篇 |
2012年 | 10578篇 |
2011年 | 11222篇 |
2010年 | 5517篇 |
2009年 | 4021篇 |
2008年 | 9117篇 |
2007年 | 9770篇 |
2006年 | 9324篇 |
2005年 | 8915篇 |
2004年 | 8249篇 |
2003年 | 7724篇 |
2002年 | 7302篇 |
2001年 | 5029篇 |
2000年 | 5634篇 |
1999年 | 4278篇 |
1998年 | 749篇 |
1992年 | 2304篇 |
1991年 | 2044篇 |
1990年 | 2030篇 |
1989年 | 1719篇 |
1988年 | 1641篇 |
1987年 | 1531篇 |
1986年 | 1565篇 |
1985年 | 1473篇 |
1984年 | 1060篇 |
1983年 | 903篇 |
1979年 | 1237篇 |
1978年 | 823篇 |
1977年 | 794篇 |
1976年 | 753篇 |
1975年 | 891篇 |
1974年 | 1135篇 |
1973年 | 1182篇 |
1972年 | 1125篇 |
1971年 | 1092篇 |
1970年 | 1016篇 |
1969年 | 1098篇 |
1968年 | 1116篇 |
1967年 | 984篇 |
1966年 | 891篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
63.
L Crespo J Graus F García-Hoz R Bárcena L Gil Grande V F Moreira J M Milicua J Sánchez J Blázquez 《Revista española de enfermedades digestivas》2007,99(11):667-670
Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques. 相似文献
64.
65.
Javier Garzón Almudena López-Fando Pilar Sánchez-Blázquez 《Neuropsychopharmacology》2003,28(11):1983-1990
Members of the R7 subfamily of regulators of G-protein signaling (RGS) proteins (RGS6, RGS7, RGS9-2, and RGS11) are found in the mouse CNS. The expression of these proteins was effectively reduced in different neural structures by blocking their mRNA with antisense oligodeoxynucleotides (ODNs). This was achieved without noticeable changes in the binding characteristics of labeled beta-endorphin to opioid receptors. Knockdown of R7 proteins enhanced the potency of antinociception promoted by morphine and [D-Ala(2), N-MePhe(4), Gly-ol(5)]-enkephalin (DAMGO)-both agonists at mu-opioid receptors. The duration of morphine analgesia was greatly increased in RGS9-2 and in RGS11 knockdown mice. The impairment of R7 proteins brought about different changes in the analgesic activity of selective delta agonists. Knockdown of RGS11 reduced [D-Ala(2)]deltorphin II analgesic effects. Those of RGS6 and RGS9-2 proteins caused [D-Ala(2)]deltorphin II to produce a smoothened time-course curve-the peak effect blunted and analgesia extended during the declining phase. RGS9-2 impairment also promoted a similar pattern of change for [D-Pen(2,5)]-enkephalin (DPDPE). RGS7-deficient mice showed an increased response to both [D-Ala(2)]deltorphin II and DPDPE analgesic effects. A single intracerebroventricular (i.c.v.) ED(80) analgesic dose of morphine gave rise to acute tolerance in control mice, but did not promote tolerance in RGS6, RGS7, RGS9-2, or RGS11 knockdown animals. Thus, R7 proteins play a critical role in agonist tachyphylaxis and acute tolerance at mu-opioid receptors, and show differences in their modulation of delta-opioid receptors. 相似文献
66.
67.
Rodrigo O Perez Angelita Habr-Gama Igor Proscurshim Fábio G Campos Desiderio Kiss Joaquim Gama-Rodrigues Ivan Cecconello 《Journal of gastrointestinal surgery》2007,11(11):1431-8; discussion 1438-40
BACKGROUND: The role of local excision for pT2 distal rectal cancer has been challenged because of the observation of high rates of lymph node metastases and local failure. However, neoadjuvant chemoradiation therapy (CRT) has led to increased local disease control and significant tumor downstaging, possibly decreasing rates of lymph node metastases. In this setting, a possible role for local excision of ypT2 has been suggested. METHODS: A total of 401 patients with distal rectal cancer underwent neoadjuvant CRT. Tumor response assessment was performed after at least 8 weeks from CRT completion. One hundred and twelve patients with complete clinical response were not immediately operated on and were excluded from the study, and 289 patients with incomplete clinical response were managed by radical surgery. Patients with final pathological stage ypT2 were analyzed to determine the risk of unfavorable pathological features that could represent unacceptable risk for local failure after local excision. RESULTS: Eighty-eight (30%) patients had ypT2 rectal cancer. Final ypT status was not associated with pretreatment radiological staging (p = 0.62). ypT status was significantly associated with the risk of lymph node metastases, risk of perineural and vascular invasion, and recurrence (p = 0.001). Lymph node metastases were present in 19% of patients with ypT2 rectal cancer. The risk of lymph node metastases in ypT2 was associated with the presence of perineural invasion (47% vs 4%; p = <0.001), vascular invasion (59% vs 6%; p < 0.001), and decreased mean interval CRT surgery (12 vs 18 weeks; p < 0.001), but not with mean tumor size (3.2 vs 3.1 cm; p = 0.8). Disease-free and overall survival rates were significantly better for patients with ypT2N0 (p = 0.02 and 0.006, respectively). Fifty-five (63%) patients with ypT2 had at least one unfavorable pathological feature for local excision (lymph node metastases, vascular or perineural invasion, mucinous type or tumor size >3 cm). CONCLUSION: Lymph node metastases were present in 19% of patients with ypT2 and were significantly associated with poor overall and disease-free survival rates. The risk of lymph node metastases could not be predicted by radiological staging or tumor size. Radical surgery should be considered the standard treatment option for ypT2 rectal cancer after CRT. 相似文献
68.
69.
José Abal Arca Isaura Parente Lamelas Raquel Almazán Ortega José Blanco Pérez María Elena Toubes Navarro Pedro Marcos Velázquez 《Archivos de bronconeumologia》2009,45(10):502-507
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group. 相似文献
70.