全文获取类型
收费全文 | 35379篇 |
免费 | 3940篇 |
国内免费 | 2328篇 |
专业分类
耳鼻咽喉 | 385篇 |
儿科学 | 394篇 |
妇产科学 | 302篇 |
基础医学 | 4266篇 |
口腔科学 | 461篇 |
临床医学 | 4082篇 |
内科学 | 5684篇 |
皮肤病学 | 782篇 |
神经病学 | 2121篇 |
特种医学 | 1688篇 |
外国民族医学 | 7篇 |
外科学 | 3550篇 |
综合类 | 5368篇 |
现状与发展 | 4篇 |
一般理论 | 3篇 |
预防医学 | 2254篇 |
眼科学 | 946篇 |
药学 | 3963篇 |
20篇 | |
中国医学 | 2465篇 |
肿瘤学 | 2902篇 |
出版年
2024年 | 197篇 |
2023年 | 672篇 |
2022年 | 1530篇 |
2021年 | 1909篇 |
2020年 | 1284篇 |
2019年 | 1327篇 |
2018年 | 1363篇 |
2017年 | 1263篇 |
2016年 | 1390篇 |
2015年 | 1913篇 |
2014年 | 2212篇 |
2013年 | 2158篇 |
2012年 | 2946篇 |
2011年 | 2998篇 |
2010年 | 2010篇 |
2009年 | 1568篇 |
2008年 | 1814篇 |
2007年 | 1785篇 |
2006年 | 1653篇 |
2005年 | 1584篇 |
2004年 | 1163篇 |
2003年 | 1271篇 |
2002年 | 1099篇 |
2001年 | 892篇 |
2000年 | 694篇 |
1999年 | 570篇 |
1998年 | 359篇 |
1997年 | 341篇 |
1996年 | 255篇 |
1995年 | 205篇 |
1994年 | 190篇 |
1993年 | 131篇 |
1992年 | 133篇 |
1991年 | 137篇 |
1990年 | 128篇 |
1989年 | 98篇 |
1988年 | 78篇 |
1987年 | 65篇 |
1986年 | 64篇 |
1985年 | 39篇 |
1984年 | 22篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 20篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 5篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1972年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
研究了欧芹素乙(Imperatorin,Imp)和异欧芹素乙(Iso-imperatorin,Isi)及对照药物维拉帕米(Verapamil,Ver)对小鼠腹腔巨噬细胞体外释放肿瘤坏死因子(Tumornecrosisfactor,TNF)的影响。结果表明:Imp、Isi及Ver对小鼠腹腔巨噬细胞体外释放TNF具有显著的抑制作用。药物浓度在10-6~10-4mol/L范围内,该抑制作用呈剂量依赖性:药物浓度达10-4mol/L时,则可完全抑制TNF的释放。 相似文献
102.
微创经皮钢板骨桥接术联合锁定加压钛板治疗胫骨远端骨折 总被引:4,自引:0,他引:4
目的探讨微创经皮钢板骨桥接术(minimallyi nvasive percutaneous plate osteosynthesis,MIPPO)联合锁定加压钛板(locking compression plate,LCP)治疗胫骨远端骨折的近期疗效。方法2004年6月~2006年3月采用MIPPO联合LCP治疗胫骨远端骨折16例,AO分型:43A1型7例,43A3型5例,43B1型2例,43C3型2例。采用3种方法复位胫骨骨折后插入LCP,用锁定螺钉固定。结果16例随访5~20个月,平均11,5月。16例切口一期愈合,骨折无延迟愈合、畸形愈合、断钉、断板等并发症。术后X线检查4~12周(平均7.6周)骨痂形成并开始部分负重,8~20周骨性愈合(平均16周),此时开始完全负重。3例出现胫骨远端内植物局部不适。根据美国足踝骨科学会评分系统对踝关节功能评分,优14例(87.5%),良2例(12,5%)。结论MIPPO具有创伤小、固定牢靠、可早期功能锻炼等优点,近期疗效满意,是治疗胫骨远端骨折的有效方法。 相似文献
103.
Background
Cancer cells recurrently develop into acquired resistance to the administered drugs. The iatrogenic mechanisms of induced chemotherapy-resistance remain elusive and the degree of drug resistance did not exclusively correlate with reductions of drug accumulation, suggesting that drug resistance may involve additional mechanisms. Our aim is to define the potential targets, that makes drug-sensitive MCF-7 breast cancer cells turn to drug-resistant, for the anti-cancer drug development against drug resistant breast cancer cells. 相似文献104.
笔者2006年3月~2008年5月应用牵引配合手法推拿治疗腰椎间盘突出症230例,收到满意疗效,总结如下。 相似文献
105.
106.
Shang Wen Chen Ji An Liang Shih Neng Yang Hui Ling Ko Fang Jen Lin 《Radiotherapy and oncology》2003,67(1):69-76
BACKGROUND AND PURPOSE: The potential risk of prolongation of treatment time in cervical cancer has been reported for many low-dose rate (LDR) studies, with an estimated loss of local control ranging from 0.3 to 1.6% per day of treatment prolongation. Since the treatment schedule for fractionated high-dose rate intracavitary brachytherapy (HDRICB) is not directly comparable with that for low-dose rate studies, this report aims to evaluate the adverse effect of treatment prolongation specifically for cervical cancer treated with HDRICB. MATERIAL AND METHODS: From September 1992 to December 1997, 257 patients diagnosed with uterine cervical cancer (35 Ib, 26 IIa, 122 IIb, 10 IIIa, 57 IIIb, 7 IVa), who underwent external radiotherapy combined with between two and four courses of HDRICB and a minimum of 3 years of follow-up (median 57 months), were analyzed. Treatment consisted of irradiation of the whole pelvis with 44-45 Gy consisting of 22-25 fractions by 5 weeks, with the dose boosted to 54-58 Gy (with central shielding) for patients diagnosed as FIGO stage IIb-IVa bilateral parametrial disease. HDRICB was performed using an Ir-192 remote afterloading technique at 1-week intervals. The standard prescribed dose for each course of HDRICB was 7.2 Gy to point A for three insertions (before July 1995), or 6.0 Gy to point A for four insertions (after July 1995). Total prescribed point A doses (external beam radiotherapy+HDRICB) ranged from 58 to 71.6 Gy (median, 65.6 Gy) for stage IB-IIA, while analogous dosage for larger lesions (stage IIb-IVa) ranged from 59 to 75.6 Gy (median, 65.6 Gy). Kaplan-Meier and multivariate analyses were used to test the effect of treatment time on pelvic control rate (PCR) and cause-specific survival (CSS) at 5 years. RESULTS: Median treatment time was 63 days. For all stages of disease, the 5-year CSS and PCR were significantly different comparing treatment times of less than and greater than or equal to 63 days [83% and 65% (P=0.004], 93% and 83% (P=0.02), respectively]. These associations were also significant for stage Ib/IIa [97% and 79% (P=0.01), and 100% and 87% (P=0.02), respectively), but not for stage IIb [75% and 72% (P=0.79), and 93% and 87% (P=0.83), respectively] or stage III [66% and 49% (P=0.2), and 83% and 72% (P=0.21), respectively]. Multivariate analysis identified three prognostic factors for CSS, stage (P<0.001), tumor response to external RT (P=0.001), and overall treatment time (OTT; P=0.006). Prognostic factors for pelvic failure were stage (P<0.001), tumor response to external RT (P=0.001), and OTT (P=0.03). Prolongation of treatment time resulted in a daily decrease in pelvic control rate of 0.67% overall, and 0.43% for stage Ib-IIa, 0.57% for stage IIb, and 0.73% for stage III patients. CONCLUSION: Analysis of the data from the current study demonstrates that the adverse effect of treatment prolongation was observed later in the treatment course for the high-dose rate (HDR) series compared to the LDR analog, however, treatment-time prolongation still negatively influenced the cause-specific survival and pelvic control rate for both dosage groups. 相似文献
107.
组织工程支架在犬急性脊髓损伤修复中应用的初步研究 总被引:6,自引:1,他引:5
目的探讨携带神经干细胞的聚碳酸亚丙酯[poly(propylene carbonate),PPC]可降解支架移植在犬脊髓急性损伤后修复中的作用。方法制作犬T13脊髓左侧半切损伤模型。将实验动物随机分为3组:细胞支架组在损伤后1周时将填充神经干细胞的PPC可降解支架植入损伤区.支架组只植入支架,对照组不作移植。8周后观察支架的组织反应、降解情况及神经干细胞的迁移分化和脊髓轴突再生情况。结果支架部分降解,管腔内未见瘢痕侵入。神经干细胞向支架邻近部位广泛迁移、扩散,并分化为3种神经细胞表型。神经丝蛋白(NF)及髓鞘碱性磷酯蛋白(MBP)免疫组化显示细胞支架组脊髓损伤区邻近部位的继发损害较其他组轻。结论携带神经干细胞的PPC可降解支架在犬脊髓组织中无明显组织反应.能够抵御瘢痕侵入:其携带的神经干细胞能够整合入邻近脊髓组织并起到一定保护作用。 相似文献
108.
Summary. Background: Pathological shear stress induces platelet aggregation that is dependent on von Willebrand factor (VWF) binding to glycoprotein (Gp)Ib‐IX‐V and phosphatidylinositol 3‐kinase activation. We tested the hypothesis that pathological shear stress stimulates phosphatidylinositol 3,4,5‐trisphosphate (PIP3) synthesis by directing the assembly of a molecular signaling complex that includes class IA phosphatidylinositol 3‐kinase (PI 3‐KIA). Methods: Platelets were subjected to 120 dynes cm?2 shear stress in a cone‐plate viscometer. Resting and sheared platelets were lyzed, immunoprecipitations of PI 3‐KIA performed, or lipids extracted for PIP3 measurements. α‐Actinin was incubated with phosphatidylinositol 4,5‐bisphosphate (PIP2), immunoprecipitated, and used as a substrate for in vitro PI 3‐KIA activity. Results: Pathological shear stress induces biphasic PIP3 production. In resting platelets, PI 3‐KIA associates with α‐actinin and PIP2. After exposure to shear stress, α‐actinin and PIP2 rapidly disassociate from PI 3‐KIA. PI 3‐KIA then gradually re‐associates with PIP2 and α‐actinin, and this complex becomes linked to GpIbα through the cytoskeleton. PIP3 production and the observed changes in the association between α‐actinin, PIP2, and PI 3‐KIA are inhibited when VWF binding to GpIbα is blocked. In a cell‐free system, α‐actinin binds PIP2 and when the α‐actinin–PIP2 complex is added to platelet PI 3‐KIA, PIP3 production is stimulated. Conclusions: These results suggest that pathological shear‐induced VWF binding to GpIb‐IX‐V stimulates PIP3 production through the assembly of an α‐actinin‐based complex that colocalizes PI 3‐KIA with substrate PIP2. 相似文献
109.
目的探讨第一、二鳃弓综合征面部不对称畸形的整形外科矫治方法。方法根据第一、二鳃弓综合征患者临床及X线所示面部双侧不对称情况,采用健侧下颌骨外板去除、颧骨截骨降低;患侧下颌体、颧骨应用健侧下颌骨外板贴附植骨或高密度多孔聚乙烯(Medpor)假体置入等术式,配合颏部水平截骨颏成形术,以缩小面部双侧宽度的差异,矫治颜面不对称畸形。结果共矫治23例,经6个月至3年的术后随访观察,双侧面部宽度差异明显缩小,正面观面部不对称明显改善。结论第一、二鳃弓综合征面部骨骼发育畸形是三维方向的,双侧面骨宽度的差异,是造成正面观面部不对称的重要因素,根据受术者的具体情况,采用以上术式的组合,扩充患侧或同时缩窄健侧骨骼,进行面部骨性支架重建,可以取得良好的矫治效果。 相似文献
110.
目的初步探讨阻塞性黄疸早期门静脉高压的机制。方法将大鼠分为胆管结扎组(B)与假手术组(A),分别于术后3、7、14d比较两组的游离门静脉压力(FPP)、血浆和肝组织内皮素(ET)浓度。结果胆总管结扎7d后门静脉压力显著高于对照组;胆总管结扎后各时段ET水平均显著高于对照组;门静脉压力与血浆ET、肝组织ET呈正相关。结论阻塞性黄疸早期即有门静脉压力的升高,它可能是体内ET水平升高致肝窦阻力增加的结果。 相似文献