全文获取类型
收费全文 | 61759篇 |
免费 | 5410篇 |
国内免费 | 2993篇 |
专业分类
耳鼻咽喉 | 565篇 |
儿科学 | 1072篇 |
妇产科学 | 429篇 |
基础医学 | 3454篇 |
口腔科学 | 1386篇 |
临床医学 | 7477篇 |
内科学 | 4975篇 |
皮肤病学 | 788篇 |
神经病学 | 1281篇 |
特种医学 | 1666篇 |
外科学 | 5159篇 |
综合类 | 16960篇 |
现状与发展 | 12篇 |
预防医学 | 7721篇 |
眼科学 | 639篇 |
药学 | 7854篇 |
68篇 | |
中国医学 | 6150篇 |
肿瘤学 | 2506篇 |
出版年
2024年 | 249篇 |
2023年 | 758篇 |
2022年 | 1822篇 |
2021年 | 2280篇 |
2020年 | 2107篇 |
2019年 | 1012篇 |
2018年 | 1088篇 |
2017年 | 1607篇 |
2016年 | 1180篇 |
2015年 | 2182篇 |
2014年 | 3079篇 |
2013年 | 3879篇 |
2012年 | 5737篇 |
2011年 | 5980篇 |
2010年 | 5612篇 |
2009年 | 4970篇 |
2008年 | 4884篇 |
2007年 | 4690篇 |
2006年 | 4282篇 |
2005年 | 3415篇 |
2004年 | 2348篇 |
2003年 | 1932篇 |
2002年 | 1468篇 |
2001年 | 1376篇 |
2000年 | 1039篇 |
1999年 | 364篇 |
1998年 | 84篇 |
1997年 | 92篇 |
1996年 | 92篇 |
1995年 | 68篇 |
1994年 | 69篇 |
1993年 | 51篇 |
1992年 | 35篇 |
1991年 | 27篇 |
1990年 | 22篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 21篇 |
1985年 | 21篇 |
1984年 | 9篇 |
1982年 | 11篇 |
1965年 | 16篇 |
1963年 | 9篇 |
1962年 | 10篇 |
1959年 | 13篇 |
1958年 | 28篇 |
1957年 | 20篇 |
1956年 | 14篇 |
1955年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
11.
H. C. LIN J. D. ELASHOFF YO-GUO GU J. H. MEYER 《Neurogastroenterology and motility》1992,4(3):157-163
Abstract While the volume of a liquid meal has been identified as the principal accelerator of gastric emptying of liquids, the relationship between meal volume and gastric emptying of solids has been controversial. With solid foods, the need to reduce solid foods into small particles (trituration) before passage might obscure the effect of meal volume on solid propulsion. To distinguish trituration from driving force as the rate-limiting factor for emptying, 75 (1.6 mm) nylon spheres were fed along with different amounts of steak meals (150, 300 and 600 g), or alternatively, 50, 100 or 200 (1.6 mm) nylon spheres were fed to six dogs with 300 g steak meals. To examine the effect of meal volume on gastric emptying, we studied the effect of different meal volumes on the speed of gastric emptying of liquids (150, 300, 600 and 1200 ml of phosphate buffer) and solids (150, 300 and 600 g of cooked beef steak) in five dogs with duodenal fistulas. Intestinal inhibition was eliminated by diverting all chyme through the fistulas. In the absence of intestinal feedback, we found that gastric emptying of steak and spheres were different in that steak emptying was independent of meal volume (g min-1 was constant across 150–600 g) while sphere emptying was affected by the number of spheres in the stomach and that liquid emptying was dependent on the meal volume (ml min-1 increased across 150–1200 ml). Thus, meal volume accelerated gastric emptying provided the process is not rate-limited by trituration. 相似文献
12.
米非司酮对人子宫内膜癌HHUA细胞ER、PR及亚型体外作用的研究 总被引:1,自引:0,他引:1
目的 探讨抗孕激素米非司酮体外对人子宫内膜癌HHU A细胞ER、PR及亚型的影响及其与抗肿瘤作用的相关性。方法 体外培养子宫内膜癌HHU A细胞,不同浓度米非司酮处理细胞4 8小时,采用逆转录-聚合酶链反应(RT- PCR)半定量法检测PR- A m RNA,PR- B m RNA的表达水平;应用免疫组化法检测HHU A细胞ER、PR受体蛋白的表达变化。结果 米非司酮(5 μmol/ L)显著地降低HHU A细胞PR- B m RNA和PR受体蛋白的表达水平(P<0 .0 5 ) ,但增加米非司酮剂量并不能增强其降调作用。抗孕激素米非司酮对HHU A细胞PR- Am RNA和ER受体蛋白表达无明显影响(P>0 .0 5 )。结论 抗孕激素米非司酮可明显降调子宫内膜癌HHU A细胞PR- B m RNA水平和PR蛋白的表达,并与抑制癌细胞增殖密切相关 相似文献
13.
角膜重度碱烧伤羊膜移植治疗实验研究 总被引:1,自引:0,他引:1
目的 探讨羊膜移植治疗兔眼重度碱烧伤的机理,为其临床应用提供基础理论依据。方法建立兔眼角膜碱烧伤模型,分别以生理盐水、氯霉素眼药水、氯霉素眼药水和0.1%地塞米松及羊膜移植进行治疗,取伤后1d,3d,7d,14d房水检测TNF-α、IL—1。结果各时段氯霉素眼药水和0.1%地塞米松组和羊膜移植治疗组与生理盐水组和氯霉素眼药水组TNF—α、IL—1的活性和含量明显受到抑制。结论抑制TNF—α和IL—1的生物合成和释放可能是羊膜移植治疗角膜碱烧伤的机理之一。 相似文献
14.
目的 探讨子宫黏膜下肌瘤行膨宫泵和等离子电切术的配合要点。方法 对30例子宫黏膜下肌摘患者使用膨宫泵和等离子电切手术。结果 30例手术顺利.均1次完成切除,平均手术时间40min,平均住院5d出院,无1例发生并发症。结论 术前心理护理、设备准备,术中正确摆放体位、熟练应用专科器械是护理配合的要点。 相似文献
15.
60例(男50,女10,年龄43±8a)经内窥镜证实的活动性消化性溃疡患者,口服法莫替丁40mg,qn,疗程2-4wk或延至6-9wk。溃疡愈合率DU2,4,6 wk分别为50%,84%,92%,SU2,4,6,8 wk分别为40%,68%,73%,82%。服药后3,7,14 d上腹痛缓解率DU为50%,80%,100%,SU为40%,75%,95%。未见严重不良反应。故法莫替丁对溃疡病,尤其是DU是一有效和安全药物。 相似文献
16.
目的 对重组人脑钠素(rhBNP)用于心脏手术围术期处理的可行性、安全性和有效性进行初步观察,并与硝普钠的作用进行比较。方法 选择择期心脏手术病人22例,随机分为rhBNP组(B组)和硝普钠(SNP)组(s组),每组11例。比较rhBNP与SNP对病人血流动力学和肝肾功能的影响。结果 与给药前和S组比较,B组用药后15、30、60、120和180min各点心输出量增加显著(P〈0.05,P〈0.01);B组与给药前比较,给药后即刻、15、30和60min时点外周血管阻力下降显著(P〈0.05);给药后即刻、15和30点与S组比较,下降显著(P〈0.05)。B组肺毛细血管楔压(PCWP)与用药前比较,用药后即刻、15、30、60、120和180min下降显著(P〈0.05,P〈0.01);与S组比较,给药后30、60、120和180min差异有统计学意义(P〈0.05,P〈0.01)。S组PCWP与用药前比较,用药后60min、120min和180min下降显著(P〈0.05)。B组与输注rhBNP前以及S组比较,平均动脉压、心率和中心静脉压差异均无统计学意义。输注rhBNP后病人24h尿量明显增加。用药过程中以及30d后进行电话随访,未见药物不良反应。结论 rhBNP用于心脏手术围术期处理是可行的,具有改善心功能和稳定循环的作用。 相似文献
17.
不同方法治疗特殊部位白癜风疗效的比较 总被引:1,自引:0,他引:1
目的通过不同方法治疗特殊部位白癜风的疗效观察,以便筛选出对不同部位白癜风的最佳治疗方法.方法随机将l 22例(375区白斑)特殊部位白癜风患者分为5组,移植微型毛胚组42例,磨削去除白斑组52例,毛囊刮取物注射组35例,液氮冷冻起疱去除白斑组30例,外用药物治疗组45例.观察其疗效,对各组病例统一疗效标准判断,统计学处理.结果移植微型毛胚组总有效率97.1 %,磨削去除白斑组总有效率94.7 %,毛囊刮取物注射组总有效率59.7 %,液氮冷冻起疱去除白斑组总有效率57.1%,外用药物治疗组总有效率45.5 %.经统计学处理,各组之间比较,差异有非常显著性意义(χ^2=111.77,P<0.005).结论特殊部位白癜风的治疗,目前仍是一个棘手的问题,上述所介绍的方法无疑是在实践中切实可行的方法,各有特色,可以根据不同部位,酌情选择最佳方法,也可以联合应用,相互补充,提高疗效. 相似文献
18.
Objective To compare the clinical efficacy of postoperative intraperitoneal chemotherapy combined with systemic chemotherapy to systemic chemotherapy alone for serosa-involved colorectal cancer. Methods According to the criteria of serosa-involving in colorectal cancer, 332 cases were divided into 2 groups prospectively without randomization. Study group (n=166) was treated with intraperitoneal chemotherapy combined with systemic chemotherapy, and control group (n=166) with systemic chemotherapy alone. Incidence of local recurrence, peritoneal metastasis, hepatic metastasis, other distant metastasis and 3-year, 5-year overall survival (OS) rate of two groups were compared. Results 3-year and 5-year OS rates of stage Ⅱ B in study group were similar to those in control group (χ2=0.612,P=0.434). The above rates of stage Ⅲ in study group were higher than those in control group (χ2=3.989,P=0.046). Either the study group or the control group, the 3-year and 5-year OS rates of patients undergone laparoscopic surgery or open surgery were similar (P=0.839, P=0.172). Incidences of local recurrence, peritoneal metastasis and hepatic metastasis in study group were 1.9%, 3.8% and 3.8% respetively, lower than those in control group (8.2%,9.5% and 10.1%,P<0.05). Distant metastasis rate in study group was similar to that in control group. In study group, intraperitoneal chemotherapy regimen with Oxaliplatin had lower rates of peritoneal metastasis and hepatic metastasis as compared to that with Cisplatin (0.9% vs 8.8% ,P=0.019), while the incidences of local recurrence and other distant metastasis were similar. Conclusions Postoperative intraperitoneal chemotherapy combined with systemic chemotherapy improves 3-year and 5-year overall survival rates in patients with stage Ⅲ serosa-involved colorectal cancer, and decreases local recurrence, peritoneal metastasis and liver metastasis rate, especially when intraperitoneal chemotherapy regimen contains Oxaliphtin. Comparing with open surgery, laparoscopic surgery dose not improve 3-year and S-year overall survival rates in patients receiving combined chemotherapy or systemic chemotherapy alone. 相似文献
19.
20.
ZENG Rong HU Zi-bing GUO Wei-tao LIN Hao SUN Xin WEI Jin-song WU Shao-ke 《中华创伤杂志(英文版)》2007,12(1):167-172
To explore the electrophysiological proper-ties of differentiation of rat bone marrow-derived stromal stem cells (rBMSCs) to neuron-like cells in vitro by edaravone, a new type of free radical scavenger. Methods: Stromal stem cells were separated from rat bone marrow with Ficoll-Paque reagent and expanded in different culture medium in vitro, rBMSCs were induced by edaravone containing serum-free L-DMEM. Morphologic observation and Western blot analysis including the ex-pression of Nav1.6, Kv1.2, Kv1.3, Cav1.2 were performed, and whole patch-clamp technique was used. Results: Cyton contraction and long processes were shown in differentiated stromal stem cells. Nav1.6, Kv1.2, Kv1.3 and Cav1.2 were expressed in both differentiated and undifferentiated cells. However, the expression of channel proteins in differentiated cells was up-regulated. Consistently, their resting potential and outward currents were also enhanced in the differentiated cells, which was especially significant in the outward rectifier potassium current. Conclusion: In vitro, neuron-like cells derived from rBMSCs, induced by edaravone, possess electrophysiologi-cal properties of neurons. 相似文献