全文获取类型
收费全文 | 44281篇 |
免费 | 4124篇 |
国内免费 | 1738篇 |
专业分类
耳鼻咽喉 | 169篇 |
儿科学 | 280篇 |
妇产科学 | 275篇 |
基础医学 | 2759篇 |
口腔科学 | 849篇 |
临床医学 | 4930篇 |
内科学 | 2584篇 |
皮肤病学 | 450篇 |
神经病学 | 1097篇 |
特种医学 | 904篇 |
外国民族医学 | 1篇 |
外科学 | 2471篇 |
综合类 | 9436篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 4991篇 |
眼科学 | 384篇 |
药学 | 9140篇 |
192篇 | |
中国医学 | 8349篇 |
肿瘤学 | 879篇 |
出版年
2024年 | 583篇 |
2023年 | 840篇 |
2022年 | 1728篇 |
2021年 | 2047篇 |
2020年 | 1760篇 |
2019年 | 1120篇 |
2018年 | 1068篇 |
2017年 | 1477篇 |
2016年 | 1585篇 |
2015年 | 1555篇 |
2014年 | 3063篇 |
2013年 | 3097篇 |
2012年 | 3132篇 |
2011年 | 3288篇 |
2010年 | 2538篇 |
2009年 | 2083篇 |
2008年 | 2114篇 |
2007年 | 2396篇 |
2006年 | 1853篇 |
2005年 | 1606篇 |
2004年 | 1357篇 |
2003年 | 1186篇 |
2002年 | 994篇 |
2001年 | 920篇 |
2000年 | 715篇 |
1999年 | 632篇 |
1998年 | 543篇 |
1997年 | 475篇 |
1996年 | 452篇 |
1995年 | 439篇 |
1994年 | 414篇 |
1993年 | 355篇 |
1992年 | 326篇 |
1991年 | 296篇 |
1990年 | 255篇 |
1989年 | 227篇 |
1988年 | 209篇 |
1987年 | 187篇 |
1986年 | 195篇 |
1985年 | 211篇 |
1984年 | 156篇 |
1983年 | 79篇 |
1982年 | 136篇 |
1981年 | 79篇 |
1980年 | 66篇 |
1979年 | 53篇 |
1978年 | 55篇 |
1977年 | 46篇 |
1976年 | 53篇 |
1974年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
本文介绍了一种应用微机BASIC语言的屈光学矩阵算法程序,可方便、迅速地解决许多眼科屈光学计算问题,如共轴球面折射系统、共轴球面反射、折射系统、球、柱镜偏心棱镜效应计算和散光柱镜系统的斜交球、柱镜组合计算等等。 相似文献
22.
23.
本文探讨6种测定DNA的方法。以吲哚反应一醋酸异成酯抽提的方法最好,比较稳定而灵敏,一般实验室条件就可进行,测定仅需0.1ml血液。 相似文献
24.
Yasushi Sano Hirohisa Machida Kuang‐I. Fu Hiroaki Ito Takahiro Fujii 《Digestive endoscopy》2004,16(Z1):S93-S96
The goal of endoscopic mucosal resection (EMR) is to allow the endoscopist to obtain tissue or resect lesions not previously amenable to standard biopsy or excisional techniques and to remove malignant lesions without open surgery. In this article, we describe the results of conventional EMR and EMR using an insulation‐tipped (IT) electrosurgical knife (submucosal dissection method) for large colorectal mucosal neoplasms and discuss the problems and future prospects of these procedures. At present, conventional EMR is much more feasible than EMR using IT‐knife from the perspectives of time, money, complication, and organ preservation. However, larger lesions tend to be resected in a piecemeal fashion; and it is difficult to confirm whether EMR has been complete. For accurate histopathological assessment of the resected specimen en bloc EMR is desirable although further experience is needed to establish its safety and efficacy. Further improvements of in EMR with special knife techniques are required to simply and safely remove large colorectal neoplasms. 相似文献
25.
通过动物痛行为反应(缩足反射)确定局部和鞘内应用川芎嗪(TMP)对ATP等P2X受体激动剂所致大鼠足底急性伤害性行为反应的影响。P2X3受体拮抗剂TNP-ATP(0.3μmol/L)明显抑制P2X受体激动剂ATP(1μmol/L)或α,β-meATP(0.6μmol/L)引起的大鼠足底急性伤害性反应。大鼠足底局部应用TMP(0.1-10mmol/L)剂量依赖性地对ATP(1μmol/L)或α,β-meATP(0.6μmol/L)引起的伤害性反应具有抑制作用。鞘内应用TMP(50mmol/L)对ATP(1μmol/L)或α,β-meATP(0.6μmol/L)引起的伤害性反应具有抑制作用。结果表明,TMP可通过阻断P2X3受体介导的伤害性兴奋传入抑制P2X受体激动剂引起的大鼠足底急性伤害性反应。 相似文献
26.
Kenji Yamao Atsushi Irisawa Hiroyuki Inoue Koji Matsuda Mitsuhiro Kida Shomei Ryozawa Yoshiki Hirooka Teruo Kozu 《Digestive endoscopy》2007,19(Z1):S180-S205
Standard imaging techniques using a curved linear array echoendocope are summarized to facilitate the attainment of expertise in endoscopic ultrasonography and endoscopic ultrasound‐guided fine needle aspiration, and to promote the widespread use of this diagnostic and therapeutic tool. Typical images of the mediastinal organs, the bilio‐pancreatic systems and neighboring organs by scanning from the esophagus, stomach, duodenal bulb, and descending portion of the duodenum, are shown in a sequential manner. The basic techniques of endoscopic ultrasound‐guided fine needle aspiration are also presented. 相似文献
27.
Electrophysiological examinations were done on 20 patients aged 40–71 years with recently diagnosed high grade non-Hodgkin's lymphomas. General chemotherapy and intrathecal chemotherapy in order to prevent central nervous system (CNS) involvement were begun. On the first day of chemotherapeutic cycle patients received intrathecally methotrexate (ITMTX) and prednisolone. Electrophysiological study was carried out twice in each subject: before ITMTX injection and a day after injection. The study procedure included: a conventional nerve conduction examination (peripheral conduction velocity and compound muscle action potential amplitude), the F wave latency and amplitude measurement and F ratio (F-M-1/2M) calculation for peroneal and tibial nerve bilaterally. Results of the first and the second examinations were statistically compared by t-Student's test. No significant differences between values of estimated parameters were found. The study revealed no recent alterations in proximal, paraspinal motor conduction and motor neuron excitability due to antidromical activation after single ITMTX administration. 相似文献
28.
S. Jepsen A. Rühling K. Jepsen B. Ohlenbusch H.K. Albers 《Clinical oral implants research》1996,7(2):133-142
The aim of this prospective study was to characterize an implant patient population exhibiting clinical signs of peri‐implantitis and to determine subsequently the incidence of progressive attachment loss. The predictive values of diagnostic parameters were evaluated. 25 patients with 54 endosseous implants that had been loaded for 41±15 months were included in the study. Clinical parameters included the assessment of plaque, bleeding on probing, probing depth, attachment levels, and Periotest® values. Probing measurements were performed in duplicate by means of a controlled force electronic probe (Periprobem). Peri‐implant crevicular fluid samples were collected and assayed for neutral proteolytic enzyme (NPE) activity (Periocheck®). Analysis of duplicate baseline probing data revealed a high degree of reproducibility (mean difference: 0.1±0.3mm). A minimum threshold of 1.0mm (>3×S.D.) loss of probing attachment was chosen to classify a site as positive for breakdown. Alternatively, the tolerance method was employed to identify sites with progressive attachment loss. After 6 months, irrespective of the analytical method, 6 percent of all sites (in 19% of the implants) and 28% of the patients had experienced further per attachment loss. There were significant differences ( p <0.05) in mean plaque (73% vs. 45%) and NPE (36% vs. 12%) scores between patients with progressive peri‐implantitis and those with stable peri‐implant conditions. Both bleeding on probing and the NPE‐test were characterized by high negative predictive values, and thus negative scores can serve as indicators for stable peri‐implant conditions. For monitoring peri‐implant health during recall visits, attachment level recordings with a controlled force electronic probe in conjunction with enzymatic diagnostic tests of the host response can be recommended. 相似文献
29.
本文比较了11例眼球异物CT与X线影像,并经手术摘出异物证实,CT眼球异物检出及定位准确性均优于X线,尤其对球壁异物的定位,而且能显示断层眼球壁轮廓,具有直观效果,CT异物影像比异物明显扩大,应警惕CT伪影可能使球壁异物定位发生误差,CT目前尚不能完全取代眼球异物常规X线检查。 相似文献
30.
实验组为45名缓解的内源性抑郁症患(男25例,女20例)。对照组为15名缓解的双相障碍患者(男8例,女7例),71名正常人(男41例,女30例)。利用作者建立的想象结局法发现:实验组想象力总分显著低于正常人组,特别是当涉及不愉快事件的测题时,单项分亦显著低于正常人。双相障碍组总分亦显著低于正常人。实验组有关性内容的比率得分显著低于正常人。 相似文献