全文获取类型
收费全文 | 12882篇 |
免费 | 702篇 |
国内免费 | 417篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 61篇 |
妇产科学 | 33篇 |
基础医学 | 1688篇 |
口腔科学 | 311篇 |
临床医学 | 619篇 |
内科学 | 1058篇 |
皮肤病学 | 151篇 |
神经病学 | 1473篇 |
特种医学 | 140篇 |
外国民族医学 | 1篇 |
外科学 | 806篇 |
综合类 | 964篇 |
现状与发展 | 1篇 |
预防医学 | 210篇 |
眼科学 | 73篇 |
药学 | 5416篇 |
中国医学 | 790篇 |
肿瘤学 | 141篇 |
出版年
2023年 | 106篇 |
2022年 | 225篇 |
2021年 | 355篇 |
2020年 | 236篇 |
2019年 | 265篇 |
2018年 | 293篇 |
2017年 | 292篇 |
2016年 | 335篇 |
2015年 | 320篇 |
2014年 | 571篇 |
2013年 | 1194篇 |
2012年 | 542篇 |
2011年 | 610篇 |
2010年 | 471篇 |
2009年 | 508篇 |
2008年 | 512篇 |
2007年 | 511篇 |
2006年 | 412篇 |
2005年 | 392篇 |
2004年 | 339篇 |
2003年 | 343篇 |
2002年 | 275篇 |
2001年 | 243篇 |
2000年 | 250篇 |
1999年 | 249篇 |
1998年 | 257篇 |
1997年 | 259篇 |
1996年 | 231篇 |
1995年 | 242篇 |
1994年 | 231篇 |
1993年 | 222篇 |
1992年 | 203篇 |
1991年 | 188篇 |
1990年 | 200篇 |
1989年 | 185篇 |
1988年 | 164篇 |
1987年 | 146篇 |
1986年 | 164篇 |
1985年 | 180篇 |
1984年 | 181篇 |
1983年 | 138篇 |
1982年 | 186篇 |
1981年 | 159篇 |
1980年 | 126篇 |
1979年 | 97篇 |
1978年 | 77篇 |
1977年 | 59篇 |
1976年 | 65篇 |
1975年 | 47篇 |
1974年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
甘草甜素和甘草酸单铵促进IL-2增强NK活性的研究 总被引:1,自引:0,他引:1
本实验采用乳酸脱氢酶释放法研究甘草甜素和甘草酸单铵对人外周血NK细胞活性的影响。结果表明,甘草甜素和甘草酸单铵本身无增强NK细胞活性的作用,但可明显促进IL-2增强NK活性,这种增强作用与甘草甜素和甘草酸单铵的浓度有关。 相似文献
32.
本文报道了用导数光谱法测定磷酸丙吡胺的尿药浓度,本方法能消除尿中杂质干扰,测定结果准确。6名受试者交叉口服磷酸丙吡胺缓释片和普通片,测得尿药浓度计算消除速度常数K,排泄速率(Δx/Δt)_(max) 所需时间,证明缓稀片药物排泄慢,药效维持时间长,且缓释片的相对生物利用度与普通片基本相同。 相似文献
33.
Pharmaceutical Research - 相似文献
34.
L. A. Cassis L. P. Dwoskin 《Journal of neural transmission (Vienna, Austria : 1996)》1994,98(2):159-164
Summary To determine if acute or chronic (21 days) losartan (10mg/kg, s.c.) regulates the renin-angiotensin system in interscapular brown adipose tissue, angiotensin II (AII) content and [3H]overflow from slices preloaded with [3H]norepinephrine were examined. Acute or chronic losartan administration had no effect on AII content. AII increased evoked [3H]overflow from slices from control rats. Losartan administration did not alter basal [3H]outflow or evoked [3H]overflow. Acute losartan administration inhibited AII-induced enhancement of evoked [3H]overflow. Tolerance developed to the inhibitory effect of losartan following chronic administration.Supported by a grant from the American Heart Association (Local Kentucky Affiliate) and by a gift from DuPont Merck Pharmaceuticals. Portions of this work have been presented in abstract form [The Pharmacologist 34(3): 157, 1992] 相似文献
35.
微囊化吲哚美辛片剂的研讨 总被引:2,自引:0,他引:2
以明胶-CAP 为囊材,经复凝聚法制备吲哚美辛微囊,再按所筛选的最佳处方制备微囊化片剂。该片与市售片相比,体外 T_(50)延长约5.6倍,家兔体内达峰时间滞后,能明显减轻对大鼠胃的刺激性。 相似文献
36.
观察了以内毒素作为致病原在支气管高反应性形成中的作用。结果:豚鼠腹腔注射内毒素后,其气道对组织胺引起哮喘潜伏期明显缩短,组织胺收缩离体气管平滑肌的PD2值明显增高,异丙肾上腺素松弛作用的PD2值显著降低,同时血浆及肺组织中组织胺含量显著增高。提示内毒素可能是呼吸道感染诱发支气管高反应性形成的重要因素,其机制与β受体功能改变及组织胺含量升高有关。 相似文献
37.
M. H. Baums G. Spahn M. Nozaki H. Steckel W. Schultz H.-M. Klinger 《Knee surgery, sports traumatology, arthroscopy》2007,15(5):687-644
Frozen shoulder is said to be a self-limiting entity but full recovery often takes more than 2 years. For that, most patients
are unwilling to tolerate painful restriction while awaiting resolution. We prospectively investigated 30 patients (16 women,
14 men) for the outcome of arthroscopic capsular release in idiopathic frozen shoulder. Results were determined by the assessment
of subjective and objective parameters to estimate both shoulder function and general health status. Symptoms persisted without
improvement for a minimum of 6 months of conservative treatment. Preoperative average American shoulder and elbow surgeons
score (ASES) was 35, visual analog scale (VAS) to measure pain was 7, and simple shoulder test (SST) was 4. Mean scores of
the physical component of SF-36 were considerably reduced. Mean forward elevation was 85°, average abduction was 70°, mean
internal rotation was 15°, and mean external rotation was 10°. Patients were followed-up at 6 weeks, 3, 6, 12 months and by
a mean of 36 months. Range of motion for all planes improved (P < 0.05). Median VAS reduced to 2, average ASES increased to 91, and SST enhanced to a mean of 10 (P < 0.05). We stated improvement of the physical components in the SF-36 questionnaire in particular bodily pain and the role-physical
score. There were no significant differences between the measurements in the early postoperative phase compared to the mid-term
follow-up (P > 0.05). Our results demonstrate that arthroscopic release of refractory idiopathic frozen shoulder combined with a gentle
manipulation provides reliable expectations for improvement in both clinical and general health status for most patients.
We recommend the use of a limb-specific and a general-health-status questionnaire to conclude the benefit of the surgical
intervention and contribute the optimization of a therapy concept more effectively. 相似文献
38.
目的 探讨膝关节纤维性僵直手术及围手术期、术后综合康复治疗的方法和意义.方法 26例膝关节纤维性僵直患者,采用髌骨外上方小切口,辅助关节镜下行关节内粘连松解,并结合徒手推拿松解.术前进行心理宣教,术后第2天开始经止痛泵维持在CPM机上行慢速全范围关节活动度功能锻炼,并行主被动伸屈膝功能锻炼、髌骨内推训练.结果 术后平均随访19个月(8~32个月),膝关节活动度从术前平均32°增至113°,平均提高81°.无皮肤坏死、创口裂开、肌腱断裂、骨折等并发症发生.结论 关节镜辅助下小切口松解治疗膝关节纤维性僵直的手术操作简单,创伤小,康复快.膝关节僵直围手术期及术后综合康复治疗,对膝关节功能恢复有重要意义. 相似文献
39.
N.D. Stafford L.T. Condon M.J.C. Rogers A.W. MacDonald S.L. Atkin 《Clinical otolaryngology》2003,28(4):314-319
The expression of somatostatin receptors 1 and 2 in benign, pre‐malignant and malignant laryngeal lesions The role of chemotherapy in squamous cell carcinoma of the larynx has not been clearly defined. Whilst toxic chemotherapy regimes may confer a marginal improvement in survival, surgery and radiotherapy remain the mainstay of treatment. Somatostatin is a naturally occurring peptide, which exerts antiproliferative and antiangiogenic effects via five membrane‐bound receptor subtypes. The expression of somatostatin receptor subtypes (SSTRs) 1 and 2 was studied in benign, pre‐malignant and malignant laryngeal specimens. Epithelial expression of SSTR1 was detected in 4/6 (67%) Reinke's oedema, 5/6 (83%) pre‐malignant and 8/12 (67%) malignant specimens, with virtually no stromal or vascular expression. High levels of epithelial SSTR2 expression were noted in all Reinke's oedema specimens, compared with low‐to‐moderate levels in only 2/6 (33%) pre‐malignant and 3/12 (25%) malignant specimens (P < 0.01). This ‘loss’ of epithelial SSTR2 expression may provide a growth advantage in pre‐malignant and malignant laryngeal lesions. Vascular expression of SSTR2 was ubiquitous in all groups, with scant stromal expression. Overall, most (>80%) pre‐malignant and malignant laryngeal specimens expressed at least one of the two SSTR subtypes studied. Somatostatin analogues may have a therapeutic role in squamous cell carcinoma of the larynx. 相似文献
40.
目的:研究原料药粒径等对盐酸普萘洛尔渗透泵片释药行为的影响。方法:取不同批号盐酸普萘洛尔及同批号重结晶前、后的原料药均按相同处方制备成渗透泵片,考察药物体外释放情况及释药24h后衣膜形态;并对上述不同原料药的粒径分别以光学显微镜和激光粒度分析仪进行证实。结果:以原料药粒径较小的渗透泵片释放完毕后衣膜变形,且不能维持零级释放,原料药粒径较大的渗透泵片结果与之相反。不同原料药经仪器证实粒径确有差异。结论:原料药的粒径可影响制备的渗透泵片的释放行为,提示性状稳定的原料药的合理选择在制剂过程中不可忽视。 相似文献