全文获取类型
收费全文 | 169566篇 |
免费 | 14463篇 |
国内免费 | 9331篇 |
专业分类
耳鼻咽喉 | 1856篇 |
儿科学 | 2545篇 |
妇产科学 | 1753篇 |
基础医学 | 18974篇 |
口腔科学 | 3111篇 |
临床医学 | 20994篇 |
内科学 | 24134篇 |
皮肤病学 | 2694篇 |
神经病学 | 8407篇 |
特种医学 | 7086篇 |
外国民族医学 | 56篇 |
外科学 | 16265篇 |
综合类 | 28639篇 |
现状与发展 | 36篇 |
一般理论 | 13篇 |
预防医学 | 13654篇 |
眼科学 | 3900篇 |
药学 | 17679篇 |
128篇 | |
中国医学 | 8960篇 |
肿瘤学 | 12476篇 |
出版年
2024年 | 415篇 |
2023年 | 1899篇 |
2022年 | 4851篇 |
2021年 | 6752篇 |
2020年 | 5165篇 |
2019年 | 4549篇 |
2018年 | 4721篇 |
2017年 | 4650篇 |
2016年 | 4738篇 |
2015年 | 7147篇 |
2014年 | 8916篇 |
2013年 | 9418篇 |
2012年 | 13633篇 |
2011年 | 14361篇 |
2010年 | 10579篇 |
2009年 | 8937篇 |
2008年 | 10759篇 |
2007年 | 10721篇 |
2006年 | 9923篇 |
2005年 | 8936篇 |
2004年 | 6966篇 |
2003年 | 6939篇 |
2002年 | 5553篇 |
2001年 | 4441篇 |
2000年 | 3722篇 |
1999年 | 2894篇 |
1998年 | 1571篇 |
1997年 | 1604篇 |
1996年 | 1164篇 |
1995年 | 1003篇 |
1994年 | 873篇 |
1993年 | 561篇 |
1992年 | 787篇 |
1991年 | 618篇 |
1990年 | 584篇 |
1989年 | 493篇 |
1988年 | 424篇 |
1987年 | 371篇 |
1986年 | 306篇 |
1985年 | 267篇 |
1984年 | 167篇 |
1983年 | 128篇 |
1982年 | 80篇 |
1981年 | 73篇 |
1980年 | 49篇 |
1979年 | 84篇 |
1978年 | 64篇 |
1976年 | 62篇 |
1974年 | 53篇 |
1973年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Theresa M Y Lee Siow Ann Chong Yiong Huat Chan Gangaharan Sathyadevan 《Revue canadienne de psychiatrie》2004,49(12):838-842
OBJECTIVES: The impact of command hallucinations on patients and the determinants of patients' compliance with them are still poorly understood. The extant literature is also divided on their association with violence. This study aimed to establish the prevalence of command hallucinations and to identify the factors that affect compliance with the commands, together with patients' coping methods. METHODS: We recruited 50 consecutive male and 50 consecutive female schizophrenia inpatients who reported hearing voices in the 6 months prior to admission. We interviewed these patients, using a semistructured questionnaire. We collected information on the contents of their auditory hallucinations and their coping methods. RESULTS: Of the patients, 53 (53%) reported command hallucinations. Of these 53 patients, 58% were women and 48% were men; 62% reported complying with the commands. They were also more likely to comply with nonviolent commands. A history of self-harm predicted compliance. Those patients who did not comply with the commands adopted various methods of coping, of which praying was the most common. CONCLUSION: Command hallucinations are common in patients with schizophrenia. Patients with a history of self-harm need closer monitoring because they may be more likely to comply with these hallucinations. Assessment should also include the patient's own coping strategies, which can be incorporated into the treatment. 相似文献
92.
Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement.
Shan Kai Yin Hong Liang Yi Wen Ying Lu Jian Guan Hong Min Wu Zhen Yu Cao Dong Zhen Yu Yan Yan Huang Chun Gen Wu 《Otolaryngology--head and neck surgery》2007,136(4):632-637
OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy. 相似文献
93.
妇科腹腔镜手术中转开腹原因分析 总被引:2,自引:1,他引:1
目的探讨妇科腹腔镜手术中转开腹的原因。方法对1234例妇科腹腔镜手术中的中转开腹患者的病情进行总结分析。结果16例腹腔镜中转开腹患者中,盆腔严重粘连者7例,盆腔恶性肿瘤4例,其他5例。结论盆腔严重粘连和盆腔恶性肿瘤是妇科腹腔镜手术中转开腹的主要原因,术前、术中充分的病情评估可能有助于减少中转开腹的发生。 相似文献
94.
R. R. Cocco K.-M. Järvinen N. Han K. Beyer H. A. Sampson 《Clinical and experimental allergy》2007,37(6):831-838
BACKGROUND: For immunotherapeutic approaches, 'critical' amino acids (AAs) within allergenic epitopes are replaced with alternate AAs to eliminate IgE antibody binding. OBJECTIVE: To determine the critical AAs for IgE binding in beta-casein and beta-lactoglobulin (BLG). METHODS: Peptides of 10-14 AAs in length were synthesized on a derivatized cellulose membrane with single AA substitutions (alanine or glycine) at each position. Membranes were incubated with a pool of sera from 15 cow's milk-allergic patients and individual sera from six of the 15 patients. In cases where no decrease in binding occurred with a single AA substitution, peptides with two AA substitutions were generated and labelled. RESULTS: Using pooled patient sera, single AA substitutions led to complete elimination of binding to six of 11 peptides for beta-casein and to all six peptides for BLG. Substituting two AAs led to an elimination of binding to four of the remaining five beta-casein epitopes. However, in three of the 11 modified beta-casein peptides and five of the six BLG peptides, no decrease in IgE binding occurred in at least one individual patient. For these patients, critical AAs other than those defined by the patient serum pool were identified, indicating a heterogeneous pattern of IgE recognition. CONCLUSION: These results indicate that AAs critical for IgE binding are more heterogeneous than initially defined by pooled milk-allergic patient sera. For future immunotherapeutic interventions with mutated peptides, critical AAs should also be identified with individual patient sera to account for heterogeneity of IgE binding between patients. 相似文献
95.
Han Reichgelt 《Journal of molecular neuroscience : MN》1996,28(1-3):231-235
Neural networks are models of the brain and have been used within Artificial Intelligence to provide alternative explanations
to the symbolic explanations of cognition in which one assumes that an intelligent system has certain explicit representations
of some aspect of the world and uses these in intelligent behavior. Obviously, if neural networks are indeed good models of
the brain, and give a satisfactory account of cognition, then they could be a valuable tool to neuroscientists. This article
gives a brief overview of the various neural network models, and critically reviews their status as models of the brain and
of cognition. 相似文献
96.
对1997年以来423例病态喉的频闪喉镜表现进行分析,结果显示声带有病理改变者其粘膜波、振幅、闭合相、运动周期性、对称性均有不同程度的变化,这种变化能直接反映声带病变的深度及范围,对喉部疾病的诊断、鉴别诊断、治疗指导及预后评价具有重要意义. 相似文献
97.
Photic evoked responses were recorded from the striate cortex of Long-Evans hooded intact, monocular visual deprivation (MD) and MD treated with NGF rats. The averaged visual evoked responses (AVER) were obtained from both hemispheres and provided comparison after binocular photic stimuli between the contralateral and the ipsilateral striate cortex with relation to the MD eye. One month of monocular visual deprivation at the critical period of development resulted in marked reduction of the amplitudes of AVER components as compared to the control recordings (P < 0.001). These changes of the AVER could be prevented by NGF infusion to lateral ventricle at the dosage of 2.0–2.4 μg/day for four weeks during the monocular deprivation. In conclusion, the change of AVER amplitudes induced by monocular visual deprivation during the critical period of development can be prevented by NGF infusion to lateral ventricle. 相似文献
98.
Two new nitro analogs of tranylcypromine, (E)-2-(p-nitrophenyl)cyclopropylamine ((E)-p-NTCP) and (E)-2-(m-nitrophenyl)cyclopropylamine ((E)-m-NTCP) were synthesized in order to examine the effect of aromatic nitro substitution on the MAO-inhibitory activity of 2-phenylcyclopropylamines. The compounds were obtained by treatingt-butyl (E)-2-(p-nitrophenyl) cyclopropanecarbamate andt-butyl (E)-2-(m-nitrophenyl)cyclopropanecarbamate withp-toluenesulfonic acid in CH3CN. Inhibitions of rat brain mitochondrial MAO-A and B by the compounds were examined using serotonin and benzylamine as the substrate at bothin vitro andex vivo levels. It was found fromin vitro measurements that(E)-p-NTCP at 6.0×10?5M elicited merely 22.5% inhibition against MAO-B without any effect on MAO-A. In contrast,(E)-m-NTCP showed fair degrees of inhibitions of MAO-A and B with IC50 values, 2.5×10?7M and 1.4×10?6M, respectively. It was also noted from(E)-m-NTCP thatm-nitro substitution caused a shift of selectivity of the inhibition toward MAO-A. According toex vivo measurements at 1.5, 3, 6, and 12 hr following the administration of a dose of 0.015 mmol/kg, i.p. to the rats, the inhibition percents of MAO-A by(E)-m-NTCP were 58.6, 63.7 63.6, and 46.6%, slightly lower than those observed by tranylcypromine. Whereas,(E)-p-NTCP at the same dose level did not show significant inhibitions against both MAO-A and MAO-B. Possible reasons for the difference in potencies between(E)-m-NTCP and(E)-p-NTCP were sought in relation to differing electron withdrawing effects ofm-andp-substituents which will influence electron density of the side chain amino functions and the partitions. 相似文献
99.
Two new diterpenoid alkaloids, flavamine ( 1) and flavadine ( 2), were isolated from the roots of ACONITUM FLAVUM Hand-Mazz. The structures were established on the bases of spectral analyses and chemical correlations with napelline ( 3) and lucidusculine ( 4), respectively. 相似文献
100.
宫颈粘液过氧化物酶在月经周期中的变化规律 总被引:3,自引:1,他引:2
本文对29例月经周期正常妇女的宫颈粘液过氧化物酶进行了30个周期的研究。在月经周期不同时间测定宫颈粘液过氧化物酶(CMPx)活性及血清促黄体生成素(LH)、雌二醇(E_2)和孕酮(P)。结果表明:在排卵前三天酶活性明显下降,至排卵后一天开始上升。卵泡期,酶活性与E_2呈负相关(r=-0.67);黄体期,酶活性与P呈正相关(r=0.79)。本研究提示:1.CMPx在排卵周期具有特定的变化规律,其变化受体内激素水平影响,可作为预告排卵的指标。2.如简化测定方法,可为自然避孕提供新途径。 相似文献