全文获取类型
收费全文 | 490篇 |
免费 | 36篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 2篇 |
妇产科学 | 9篇 |
基础医学 | 15篇 |
口腔科学 | 8篇 |
临床医学 | 70篇 |
内科学 | 138篇 |
神经病学 | 14篇 |
特种医学 | 13篇 |
外科学 | 126篇 |
综合类 | 59篇 |
预防医学 | 18篇 |
眼科学 | 5篇 |
药学 | 25篇 |
1篇 | |
中国医学 | 15篇 |
肿瘤学 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 11篇 |
2021年 | 33篇 |
2020年 | 35篇 |
2019年 | 22篇 |
2018年 | 28篇 |
2017年 | 21篇 |
2016年 | 20篇 |
2015年 | 21篇 |
2014年 | 40篇 |
2013年 | 37篇 |
2012年 | 35篇 |
2011年 | 30篇 |
2010年 | 28篇 |
2009年 | 23篇 |
2008年 | 19篇 |
2007年 | 20篇 |
2006年 | 18篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有545条查询结果,搜索用时 31 毫秒
71.
The fish welfare debate is intensifying. Consequently, more research is carried out to further our knowledge on fish welfare in aquaculture. We define here a series of key parameters to substantiate an acute response to a supposedly painful stimulus: a standardized tailfin clip.Ultrastructural analysis of common carp (Cyprinus carpio) tailfin indicates the presence of A-δ and C-type axons, which are typical for transmitting nociceptive signals in (higher) vertebrates. In Nile tilapia (Oreochromis niloticus), responses to a tailfin clip were studied and the unavoidable acute stress associated with the handling required for this procedure. A series of key parameters for further studies was defined. The responses seen in ‘classical’ stress parameters (e.g., changes in plasma cortisol, glucose and lactate levels) did not allow discrimination between the clipping procedure and the handling stress. However, three parameters indicated a differential, stronger response to the clip stimulus itself: first, swimming activity increased more and clipped fish spent more time in the light (in a tank where half the volume is covered by dark material); second, the gill's mucus cells released their content as observed 1 h after the clip, and this response is transient (no longer observed at 6 h post clipping). Third, branchial Na+/K+-ATPase activity assayed in vitro was not affected by the procedures, but a remarkable migration of Na+/K+-ATPase immunoreactive (chloride) cells into the lamellar epithelium was observed as of 6 h post clipping. We conclude that the differential response to clipping supports that this is a painful procedure that evokes a transient specific physiological status. 相似文献
72.
73.
替米沙坦对大鼠动脉血清钙调神经磷酸酶的影响 总被引:3,自引:1,他引:2
目的研究替米沙坦对动脉血清钙调神经磷酸酶(CaN)影响。方法92只同龄SD大鼠随机分为对照组(N)、假手术组(S)、2K1C+蒸馏水组(K)、2K1C+替米沙坦组(T)。N组不加任何干预,S组分离左肾动脉不缩窄,K组和T组缩窄左肾动脉,建立肾血管性高血压模型。术后第3周始,T组灌胃给替米沙坦10mg.(kg.d)-1,K组灌胃给蒸馏水10mg.(kg.d)-1。在术后第4、6、10周末,超声心动图观察心脏结构及功能,每组至少取6只开腹,经腹主动脉插管测血压,收集腹主动脉血后处死,分离血清,酶联免疫吸附技术(ELISA)检测CaN水平,比色法测CaN活性。结果①与N组、S组比较,K组血压(收缩压、舒张压)明显升高(P<0.01),经替米沙坦治疗后,血压明显降低(P<0.01);②K组舒张末期室间隔厚度、收缩末期室间隔厚度、舒张末期左室后壁厚度、收缩末期左室后壁厚度明显增加(P均<0.01),替米沙坦治疗后,左室壁厚度均明显下降(P均<0.01);③K组动脉血清CaN水平明显升高(P<0.01),替米沙坦治疗后,动脉血清CaN水平明显降低(P<0.01)。结论外周动脉血CaN水平在左室肥厚中也发生改变;替米沙坦抑制左心室重构作用,其机制可能与其降低循环中CaN水平有关。 相似文献
74.
目的:比较不同内径银夹缩窄大鼠肾动脉诱导的2K1C高血压模型效果.方法:用U型银夹缩窄大鼠右侧肾动脉建立2K1C高血压模型,分为4组:假手术组、2K1C-0.2 mm组、2K1C-0.25 mm组和2K1C-0.3 mm组.0~8周内,用无创尾动脉压测量仪测量大鼠尾动脉压.第8周末,BL-420S生物机能实验系统监测各组动物的心功能,计算大鼠心重量指数(HW/BW)、左和右肾脏重量指数(LKW/BW和RKW/BW),HE染色观察胸主动脉重构情况,比色法测定心肌组织羟脯氨酸含量,放免法测定血清中血管紧张素Ⅱ(Ang Ⅱ)的含量.结果:与假手术组比较,2K1C-0.25 mm组和2K1C-0.3 mm组,成模率高、肾脏固缩少,心功能损伤明显,HW/BW、羟脯氨酸和Ang Ⅱ的含量明显升高,胸主动脉发生明显重构;而2K1C-0.2 mm组,成模率低、肾脏固缩多,心功能损伤不明显.结论:0.25 mm和0.3 mm内径的银夹诱导的2K1C肾性高血压模型,成模率高,模型更稳定. 相似文献
75.
76.
Hideki Kobara Hirohito Mori Noriko Nishiyama Shintaro Fujihara Keiichi Okano Yasuyuki Suzuki Tsutomu Masaki 《Journal of gastroenterology and hepatology》2019,34(1):22-30
Rescue therapy for gastrointestinal (GI) refractory bleeding, perforation, and fistula has traditionally required surgical interventions owing to the limited performance of conventional endoscopic instruments and techniques. An innovative clipping system, the over‐the‐scope clip (OTSC), may play an important role in rescue therapy. This innovative device is proposed as the final option in endoscopic treatment. The device presents several advantages including having a powerful sewing force for closure of GI defects using a simple mechanism and also having an innovative feature, whereby a large defect and fistula can be sealed using accessory forceps. Consequently, it is able to provide outstanding clinical effects for rescue therapy. This review clarifies the current status and limitations of OTSC according to different indications of GI refractory disease, including refractory bleeding, perforation, fistula, and anastomotic dehiscence. An extensive literature search identified studies reported 10 or more cases in which the OTSC system was applied. A total of 1517 cases described in 30 articles between 2010 and 2018 were retrieved. The clinical success rates and complications were calculated overall and for each indication. The average clinical success rate was 78% (n = 1517) overall, 85% for bleeding (n = 559), 85% (n = 351) for perforation, 52% (n = 388) for fistula, 66% (n = 97) for anastomotic dehiscence, and 95% (n = 122) for other conditions, respectively. The overall and severe OTSC‐associated complications were 1.7% (n = 23) and 0.59% (n = 9), respectively. This review concludes that the OTSC system may serve as a safe and productive device for GI refractory diseases, albeit with limited success for fistula. 相似文献
77.
通过动物实验,对一种新型国产二尖瓣夹合器系统的可行性和安全性进行评价。14只正常三元杂交系猪分为实验组10只和对照组4只,实验组植入新型二尖瓣夹合器系统,对照组行传统二尖瓣修复术。分别于术前、术后不同时间点行超声心动图检查、血液检查,术后140 d对动物安乐死取材,进行心脏及主要脏器大体、病理检查,观察植入后的情况。实验组共8只动物、对照组共4只动物达到实验终点,所有动物术中未出现夹合器脱落、心脏破裂、瓣膜损伤、顽固性心律失常、脏器栓塞、心力衰竭、死亡等严重并发症。超声显示,所有夹合器均固定在二尖瓣处,不同时间点二尖瓣平均跨瓣压差、左心室射血分数等两组间均未见具有统计学意义的差异。血液学检查,未见植入器械对肝肾功能产生明显影响。病理检查提示,夹合器周围瓣叶呈现慢性炎症、黏液样变性、少量出血,未引起二尖瓣及心脏组织损伤,未出现心脏血栓、感染,各脏器也未见血栓栓塞。动物实验结果表明,新型国产二尖瓣夹合器系统生物相容性好,能够有效固定在二尖瓣处而不引起严重的相关并发症。 相似文献
78.
79.
Comparison of clipping with and without epinephrine injection for the prevention of post‐polypectomy bleeding in pedunculated colon polyps
下载免费PDF全文
![点击此处可从《Journal of gastroenterology and hepatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
80.
目的分析比较内镜下药物喷洒与内镜下金属钛夹联合止血钳治疗上消化道出血的效果。方法本次研究对象为2018年5月-2019年5月本院收治的84例上消化道出血患者,随机分为对照组42例(内镜下药物喷洒治疗)和研究组42例(内镜下金属钛夹联合止血钳治疗),对比两组的疗效。结果研究组治疗总体有效率(97.62%)高于对照组(80.95%),(P<0.05)。研究组隐血转阴时间、住院时间为(3.02±0.50)d、(6.37±0.50)d与对照组隐血转阴时间、住院时间(6.02±1.00)d、(9.67±2.00)d相比明显更优,两组数据差异有统计学意义(P<0.05)。结论内镜下金属钛夹联合止血钳治疗上消化道出血临床效果好,值得患者信赖。 相似文献