全文获取类型
收费全文 | 7677篇 |
免费 | 469篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 173篇 |
妇产科学 | 120篇 |
基础医学 | 923篇 |
口腔科学 | 219篇 |
临床医学 | 757篇 |
内科学 | 1613篇 |
皮肤病学 | 108篇 |
神经病学 | 949篇 |
特种医学 | 256篇 |
外科学 | 1330篇 |
综合类 | 83篇 |
一般理论 | 1篇 |
预防医学 | 409篇 |
眼科学 | 76篇 |
药学 | 424篇 |
中国医学 | 12篇 |
肿瘤学 | 599篇 |
出版年
2023年 | 58篇 |
2022年 | 118篇 |
2021年 | 194篇 |
2020年 | 126篇 |
2019年 | 153篇 |
2018年 | 176篇 |
2017年 | 125篇 |
2016年 | 185篇 |
2015年 | 170篇 |
2014年 | 243篇 |
2013年 | 312篇 |
2012年 | 492篇 |
2011年 | 498篇 |
2010年 | 270篇 |
2009年 | 251篇 |
2008年 | 398篇 |
2007年 | 378篇 |
2006年 | 394篇 |
2005年 | 360篇 |
2004年 | 361篇 |
2003年 | 348篇 |
2002年 | 290篇 |
2001年 | 206篇 |
2000年 | 188篇 |
1999年 | 178篇 |
1998年 | 72篇 |
1997年 | 76篇 |
1996年 | 63篇 |
1995年 | 52篇 |
1994年 | 51篇 |
1993年 | 49篇 |
1992年 | 103篇 |
1991年 | 88篇 |
1990年 | 82篇 |
1989年 | 84篇 |
1988年 | 65篇 |
1987年 | 67篇 |
1986年 | 77篇 |
1985年 | 61篇 |
1984年 | 47篇 |
1983年 | 45篇 |
1982年 | 36篇 |
1981年 | 40篇 |
1978年 | 36篇 |
1977年 | 36篇 |
1976年 | 42篇 |
1975年 | 51篇 |
1974年 | 40篇 |
1973年 | 40篇 |
1972年 | 35篇 |
排序方式: 共有8190条查询结果,搜索用时 15 毫秒
81.
目的:探讨人脑肿瘤p53表达与对亚硝脲类抗癌药耐药的关系。方法:采用WesternBlot分析,对10株人脑肿瘤细胞的p53、ERCC2表达进行检测,并与肿瘤对二氯乙基亚硝脲(BCNU)及二氯乙基肉芥子亚硝脲(SarCNU)耐药性进行比较。结果:ERCC2表达与肿瘤对BCNU和SarCNU耐药相关。p53与BCNU和SarCNU耐药相关。多元回归分析,ERCC2+p53与BCNU和SarCNU间的相关性明显提高。结论:ERCC2和p53基因表达在人脑肿瘤对亚硝脲类抗癌药耐药中起重要作用。 相似文献
82.
F. Mohr W. Hubmann W. Bender S. Hönicke Ch. Wahlheim R. Cohen C. Haslacher R. Schlenker P. Werther 《European archives of psychiatry and clinical neuroscience》1996,246(5):240-248
A German version of the Neurological Evaluation Scale (NES) was administered to 143 schizophrenic patients, 45 of them being severly chronic and disabled. Seventy-eight alcohol-dependent inpatients and 57 healthy volunteers were tested as control groups. Neurological soft signs (NSS) were rated with convincing agreement. Schizophrenic patients are more impaired on all scales than healthy controls. The chronic, severly disabled schizophrenic patients are more impaired compared with the main group of schizophrenic patients and both control groups. A significant patients and alcohol-dependent patients was only found for the subscale Motor Coordination. Compared with healthy controls the alcohol-dependent patients show a higher NES total score. The NES total score was related to the relative width of the third ventricle. Total score and subscales were correlated consistently with the level of cognitive functioning as measured by the Raven Standard Progressive Matrices and various neuropsychological tests presumably sensitive to dysfunctions of the prefrontal cortex. The NSS were related to positive as well as to negative symptoms, the correlations with negative symptoms being confined to items of Cognitive Disorganization. This close association of psychomotor and cognitive dysfunctions may be seen as related to the frequently discussed dysfunctions of the prefrontal cortex or the neurointegrative deficit postulated by Meehl. 相似文献
83.
Raphael Y. Gershon 《Journal canadien d'anesthésie》1996,43(10):1068-1071
Purpose
This case report describes a radiologically proven subdural catheter placed in a term parturient, which consistently performed as an epidural catheter for both labour analgesia as well as surgical anaesthesia.Clinical features
The patient was a 26-yr-old, 52.7 kg, 140 cm healthy woman with a 39 wk intrauterine pregnancy. At initiation of epidural blockade, and for many hours throughout labour, an appropriate volume and concentration of local anaesthetic achieved an appropriate analgesic sensory level (10 ml bupivacaine 0.25%, bilateral T10 sensory level). However, for Caesarean section, while an appropriate volume and concentration of local anaesthetic achieved an appropriate surgical anaesthetic sensory level (15 ml bupivacaine 0.5%, bilateral T4 sensory level), there was no demonstrable motor blockade (0 on the Bromage scale). The Caesarean section was performed without incident, and without the need for supplemental intravenous opioids or anxiolytics.Conclusion
We report the case to question the commonly held beliefs of subdural catheter presentation. We questioned the catheter position, and proved its subdural placement, only after larger volumes of higher concentration local anaesthetic did not achieve expected goals. It is possible that a high percentage of epidural catheters may be subdural, unbeknownst to the practitioner. 相似文献84.
85.
Raphael Reiss M.D. Alexander A. Deutsch M.D. Avinoam Eliashiv M.D. 《World journal of surgery》1983,7(4):522-526
The high rates of abdominal disorders in a growing population of geriatric patients and the greater willingness of the surgeon to cope with major problems in the elderly are factors contributing to a steady increase in abdominal procedures in this group. Four hundred consecutive major abdominal surgical procedures in patients over 70 years of age were submitted for computer analysis, the purpose of which was to determine the principal factors affecting mortality and morbidity. The etiological profile of abdominal surgery in the elderly was characterized by a high percentage of procedures related to the biliary tract, with the second largest group being those for intestinal obstruction due to benign and malignant conditions. The decision-making process in geriatric surgery is of great importance, requiring consideration of ethical, medico-legal and economic factors in addition to the purely medical ones. Analysis of data presented in this series leads to the following conclusions:
- There is a declining mortality rate in all elective operations in the elderly, in the absence of widespread malignancy.
- Timing is all important in abdominal emergencies in the elderly, and early operations are usually more successful than either immediate or delayed operations.
- Definitive procedures are sometimes both safer and more cost effective than minimal procedures performed under such circumstances.
- The principal factors leading to high mortality rates are the presence of malignancy, generalized peritonitis, and moderate-to-severe involvement of life-support systems.
86.
87.
Microsomal monooxygenases catalyze the biosynthesis of epoxides from olefinic and aromatic compounds whilst microsomal epoxide hydratase and cytoplasmic glutathione S-transferases are responsible for their further biotransformation. Although catalytically very efficient the cytoplasmic glutathione S-transferases play, due to their subcellular localization, a minor role in the inactivation of epoxides derived from large lipophilic compounds and were, therefore, not included in this study. It was shown with such a lipophilic compound, benzo(a)pyrene, as a model substance and with liver enzyme mediated bacterial mutagenesis as biological endpoint that species and strain differences in epoxide hydratase and monooxygenases are reflected in very dramatic differences in mutagenicity of benzo(a)pyrene which varied from extremely potent to a degree which could easily be overlooked. In order to investigate whether the differences in enzyme activities were causally linked to the observed differences in mutagenicity, the enzyme activities were modulated by inhibition and induction. These manipulations were always accompanied by the corresponding changes in mutagenicity.It is concluded that species such as mice which possess high monooxygenase activity but very low epoxide hydratase activity are much more susceptible than man to those toxic effects which are mediated by metabolically formed epoxides which are substrates of epoxide hydratase. In this regard, it is especially noteworthy that mice possess a much lower hepatic epoxide hydratase activity than man.Presented at the Symposium Influence of Metabolic Activations and Inactivations on Toxic Effects held at the 18th Spring Meeting of the Deutsche Pharmakologische Gesellschaft, Section Toxicology, D-6500 Mainz, March 15, 1977 相似文献
88.
89.
The aim of this paper is to review the current knowledge of phantom tooth pain, a neuropathic facial pain disorder, thought to result from peripheral nerve injury. Phantom tooth pain is a deafferentation pain disorder of persistent toothache in teeth that have been denervated (usually by root canal treatment) or pain in the area formerly occupied by teeth prior to their extraction. The pain usually extends to the facial structures adjacent to tissues that have undergone deafferentation. The clinical characteristics, differential diagnosis, epidemiology, and treatment of phantom tooth pain are reviewed. Suggestions for further research include the need for controlled treatment trials and modification of current criteria. CONCLUSIONS: Phantom tooth pain has much in common with other phantom pain disorders. In the absence of controlled clinical trials specifically directed to phantom tooth pain, treatment should be guided by standards used for other neuropathic pain disorders. Revised diagnostic criteria for phantom tooth pain are proposed. 相似文献
90.
Raphael P Viscidi Mark Schiffman Allan Hildesheim Rolando Herrero Philip E Castle Maria C Bratti Ana Cecilia Rodriguez Mark E Sherman Sophia Wang Barbara Clayman Robert D Burk 《Cancer epidemiology, biomarkers & prevention》2004,13(2):324-327
Whether antibodies to human papillomavirus (HPV) capsids, elicited by natural infection, are protective is unknown. This question was addressed in a population-based cohort of 7046 women in Costa Rica by examining the association between baseline seroreactivity to HPV-16, HPV-18, or HPV-31 virus-like particles and the risk of subsequent HPV infection at a follow-up visit 5-7 years after enrollment. Seropositivity to HPV-16, HPV-18, or HPV-31 was not associated with a statistically significant decreased risk of infection with the homologous HPV type [relative risk (RR) and [95% confidence interval (CI)], 0.74 (0.45-1.2), 1.5 (0.83-2.7), and 0.94 (0.48-1.8), respectively]. Seropositivity to HPV-16 or HPV-31 was not associated with a decreased risk of infection with HPV-16 or its genetically related types [RR (95% CI), 0.82 (0.61-1.1) and 0.93 (0.68-1.2), respectively]. Seropositivity to HPV-18 was not associated with a decreased risk of infection with HPV-18 or its genetically related types (RR 1.3; 95% CI 1.0-1.8). Thus, we did not observe immunity, although a protective effect from natural infection cannot be excluded because of the limits of available assays and study designs. 相似文献