全文获取类型
收费全文 | 3643篇 |
免费 | 175篇 |
国内免费 | 61篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 89篇 |
妇产科学 | 99篇 |
基础医学 | 398篇 |
口腔科学 | 38篇 |
临床医学 | 478篇 |
内科学 | 653篇 |
皮肤病学 | 57篇 |
神经病学 | 263篇 |
特种医学 | 248篇 |
外科学 | 361篇 |
综合类 | 318篇 |
预防医学 | 264篇 |
眼科学 | 35篇 |
药学 | 333篇 |
3篇 | |
中国医学 | 100篇 |
肿瘤学 | 116篇 |
出版年
2023年 | 35篇 |
2022年 | 61篇 |
2021年 | 97篇 |
2020年 | 90篇 |
2019年 | 70篇 |
2018年 | 61篇 |
2017年 | 59篇 |
2016年 | 57篇 |
2015年 | 80篇 |
2014年 | 121篇 |
2013年 | 143篇 |
2012年 | 220篇 |
2011年 | 218篇 |
2010年 | 160篇 |
2009年 | 174篇 |
2008年 | 199篇 |
2007年 | 201篇 |
2006年 | 182篇 |
2005年 | 147篇 |
2004年 | 106篇 |
2003年 | 89篇 |
2002年 | 82篇 |
2001年 | 65篇 |
2000年 | 53篇 |
1999年 | 44篇 |
1998年 | 42篇 |
1997年 | 54篇 |
1996年 | 53篇 |
1995年 | 42篇 |
1994年 | 51篇 |
1993年 | 36篇 |
1992年 | 13篇 |
1991年 | 22篇 |
1990年 | 24篇 |
1989年 | 26篇 |
1988年 | 31篇 |
1987年 | 29篇 |
1986年 | 15篇 |
1985年 | 35篇 |
1984年 | 26篇 |
1983年 | 16篇 |
1980年 | 15篇 |
1977年 | 13篇 |
1975年 | 12篇 |
1959年 | 43篇 |
1958年 | 66篇 |
1957年 | 75篇 |
1956年 | 73篇 |
1955年 | 83篇 |
1954年 | 51篇 |
排序方式: 共有3879条查询结果,搜索用时 15 毫秒
31.
32.
目的 探讨喉癌患者不同手术方式的临床疗效及预后影响因素.方法 以本院2008年1月~2011年1月收治的60例喉癌手术治疗患者为研究对象,根据手术方式的不同分为全切除组及部分切除组,比较两组患者的3年生存率及术后早期生活质量,分析影响喉癌患者预后水平的危险因素.结果 两组患者3年生存率差异无统计学意义(P>0.05),部分切除组患者术后早期生活质量高于全切除组,差异有统计学意义(P<0.05).单因素分析结果显示,年龄、术前是否存在淋巴结转移、TNM分期情况及患者术后早期生活质量是影响患者预后水平的主要因素.结论 部分喉癌切除术在治疗喉癌中,与全切除术生存率相近,但术后早期生活质量较高;年龄、术前是否存在淋巴结转移、TNM分期情况及患者术后早期生活质量是影响预后的主要因素. 相似文献
33.
目的:构建SV40T抗原的特异性真核表达载体,并导入胃癌细胞株SGC7901进行表达鉴定.方法:扩增小鼠H /K ATPase β亚基启动子,与pMT18-T载体相连,并将其亚克隆至真核表达载体 pcDNA3.1(-),构建pcDNA3.1(-)/HK; 从含有SV40T基因的pLITAg质粒酶切回收SV40T基因,与pcDNA3.1(-)/HK相连,构建胃壁细胞特异性表达载体pcDNA3.1(-)/HKSV,同时构建非特异性表达载体pcDNA3.1(-)/SV,进行酶切及测序鉴定.用脂质体转染的方法将构建的载体导入胃癌细胞株SGC7901,PCR扩增基因组DNA,RT-PCR检测SV40T mRNA的表达.结果:限制性内切酶分析与测序结果显示,真核表达载体pcDNA3.1/HKSK构建成功;转染该载体的SGC7901细胞可检测到SV40T基因DNA的存在,且有SV40T mRNA的表达.结论:特异性表达SV40T基因的真核表达载体pcDNA3.1(-)/HKSV构建成功. 相似文献
34.
35.
36.
??OBJECTIVE To investigate the influencing mechanism of the particle size of hydroxypropyl methylcellulose (HPMC) on the release behavior of nifedipine from a sustained-release tablet system based on the compaction properties of HPMC. METHODS The compaction properties of HPMC K4M of different particle sizes were determined. Hydrophilic matrix sustained-release tablets were prepared using nifedipine as the active ingredient and HPMC K4M as a hydrophilic matrix former. The effect of compaction properties of HPMC K4M on the porosity, release, and other properties of nifedipine hydrophilic matrix sustained-release tablets were also studied. RESULTS The decrease of the particle size of HPMC K4M resulted in higher bulk density, tap density, compressibility index, and tensile strength and smaller elastic recovery of HPMC K4M, which all led to the decrease of thickness and porosity and the increase of HPMC concentration per unit volume of nifedipine hydrophilic matrix sustained-release tablets. These factors resulted in faster gelation rate of nifedipine sustained-release tablets and decreased water ingress and polymer swelling, so the release of nifedipine from the delivery system was prolonged. CONCLUSION The obviously different compaction properties of HPMC of different particle sizes influence the porosity and gelation rate and then the release of hydrophilic matrix nifedipine sustained-release tablets. 相似文献
37.
桂枝饮片标准汤剂质量标准研究 总被引:5,自引:9,他引:5
目的制备桂枝饮片标准汤剂,并进行质量标准研究。方法依照标准汤剂的制备要求,制备15批桂枝饮片标准汤剂,以肉桂酸作为定量检测指标,计算转移率与出膏率,并建立其HPLC指纹图谱分析方法。结果通过对15批桂枝标准汤剂进行测定,肉桂酸转移率为56.93%~94.06%,出膏率为3.30%~9.40%;并用中药色谱指纹图谱相似度评价系统(2012A)软件进行指纹图谱分析,标定了9个共有峰,确认4个,分别为原茶儿酸(1号峰)、香豆素(4号峰)、肉桂酸(6号峰)、桂皮醛(7号峰)。对15批桂枝饮片标准汤剂分别进行了相似度评价,其相似度均高于0.95。结论建立了桂枝饮片标准汤剂指纹图谱,该方法精密度、稳定性和重复性良好,具有一定的鉴别意义,可为桂枝配方颗粒的质量控制提供参考。 相似文献
38.
Verguts J Vergote I Amant F Moerman P Koninckx P 《Journal of minimally invasive gynecology》2008,15(6):700-703
Study ObjectivePort site metastases (PSM) after laparoscopic surgery for advanced-stage ovarian carcinoma are a cause of concern, but the pathophysiology is unknown. Because CO2 pneumoperitoneum was recently demonstrated to be a cofactor in adhesion formation and tumor implantation in a laparoscopic mouse model, and because both could be prevented by the addition of 4% oxygen to the CO2 pneumoperitoneum, we wanted to test the hypothesis that PSM could be related to tumor cell hypoxia during CO2 pneumoperitoneum.DesignA randomized controlled pilot trial to compare the incidence of PSM in women undergoing laparoscopy with a pure CO2 pneumoperitoneum in comparison with women with CO2 pneumoperitoneum with the addition of 4% oxygen (Canadian Task Force classification C).SettingUniversity Hospital Gasthuisberg, Leuven, Belgium.PatientsSince January 1, 2007, 22 consecutive women undergoing laparoscopy for suspected ovarian cancer with subsequent debulking laparotomy were included.InterventionsDiagnostic laparoscopy with 100% CO2 versus laparoscopy with addition of 4% oxygen.Measurements and Main ResultsIn the control group, 9 (47%) PSM found in 19 port sites were excised. In the CO2+oxygen group, a similar incidence was found, that is, 8 (50%) PSM in 16 port sites. The incidence of PSM was higher in small women (p <.018) and in high-grade malignancies. The pathophysiology of PSM is unknown, but besides direct wound contamination, aerosolization of tumor cells and gas leaks have been suggested together with a causal relationship with the CO2 pneumoperitoneum. Tumor cell hypoxia probably is not an important mechanism because PSM were not prevented by adding small amounts of oxygen to the CO2 pneumoperitoneum.ConclusionThe hypothesis of tumor cell hypoxia by the CO2 pneumoperitoneum as a mechanism for PSM could not be confirmed. 相似文献
39.
Background Aggressive angiomyxoma (AA) is a rare vulvovaginal mesenchymal neoplasm with a marked tendency to local recurrence but which
usually does not metastasize.
Case report We describe a case of AA in the left labium majus pudendi in a 47-year-old woman who underwent incomplete surgical excision.
Follow-up 2 years later revealed no recurrence.
Conclusion In the past, most authors advocated wide excision even if genitourinary and digestive tract resection were necessary. These
days, a less radical surgery is recommended, but the significance of hormonal treatment and/or radiation therapy is not clear
yet. Further investigation is necessary. 相似文献
40.