首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   969篇
  免费   87篇
  国内免费   74篇
林业   20篇
农学   48篇
基础科学   25篇
  24篇
综合类   262篇
农作物   34篇
水产渔业   165篇
畜牧兽医   468篇
园艺   64篇
植物保护   20篇
  2024年   1篇
  2023年   26篇
  2022年   30篇
  2021年   51篇
  2020年   37篇
  2019年   36篇
  2018年   22篇
  2017年   54篇
  2016年   44篇
  2015年   42篇
  2014年   30篇
  2013年   74篇
  2012年   75篇
  2011年   85篇
  2010年   47篇
  2009年   33篇
  2008年   40篇
  2007年   41篇
  2006年   30篇
  2005年   30篇
  2004年   45篇
  2003年   29篇
  2002年   32篇
  2001年   29篇
  2000年   21篇
  1999年   32篇
  1998年   16篇
  1997年   25篇
  1996年   22篇
  1995年   11篇
  1994年   5篇
  1993年   6篇
  1992年   5篇
  1991年   6篇
  1990年   5篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1984年   2篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
排序方式: 共有1130条查询结果,搜索用时 15 毫秒
91.
目的:为临床设计背部皮神经营养血管皮瓣提供解剖学基础。方法:在l7例34侧成人躯干标本上,用显微解剖法观测第l—l2胸神经后皮支及其营养血管的来源.走行及分布规律。结果:第l—l2胸神经后皮支的伴行动脉为肋间后动脉的背侧皮支。皮神经及其伴行动脉于脊柱两旁相应肋间穿出深筋膜,呈节段性、重叠性分布于背部皮肤,皮神经营养血管相互间形成丰富的吻合。结论:可设计以第l—12胸神经后皮支及其营养血管为蒂的皮神经营养血管皮瓣。  相似文献   
92.
Lactic acid bacteria play an essential role in the food industry in the manufacture of many fermented products (cheese, yogurt, fermented vegetables, etc.). Application of these organisms is now being extended to the area of health improvement, as their probiotic activities become known. Probiotics are defined as viable microorganisms that exert a beneficial effect on the health of the host when they are ingested in sufficient quantity. Lactic acid bacteria and bifidobacteria isolated from the human intestine are the most common probiotics used for human consumption. The development of new probiotics with new beneficial effects is eagerly awaited in the food industry. This review introduces Lactococcus, which are one of the genera of lactic acid bacteria and are mainly isolated from dairy products and fermented vegetables, as new probiotics, focusing especially on Lactococcus lactis H61, which improves skin status in Japanese women with oral intake of heat‐killed or live cells. The deduced mechanisms associated with the beneficial effects of strain H61 are also discussed.  相似文献   
93.
A 1‐year‐old, female spayed, domestic shorthair cat presented for blepharospasm of the right eye. Slit‐lamp biomicroscopic examination showed focal corneal ulceration and presumptive keratomalacia of the right eye. Examination of the left eye was normal apart from a focal endothelial opacity. Within the first 24 h of medical management, the right eye developed marked corneal edema and globular anterior protrusion of the corneal surface consistent with feline acute corneal hydrops (FACH). Surgical management consisted of a bridge conjunctival graft, nictitating membrane flap, and temporary tarsorrhaphy. Resolution of corneal edema and pain occurred in the right eye within 24 days. Spectral domain optical coherence tomography (SD‐OCT) of the anterior segment was performed in both eyes. Conjunctival tissue from the bridge graft precluded examination of deeper corneal structures in the right eye. The left eye displayed a focal separation of the corneal endothelium and Descemet's membrane from the overlying stroma. These SD‐OCT findings are similar to the analogous syndrome found in humans and represent a potential etiology for FACH of the right eye in the case presented here. Unfortunately, the cat was lost to follow‐up and the progression of this lesion to FACH in the left eye could not be determined.  相似文献   
94.
95.
ABSTRACT

1. Olive leaf extract (OLE) and hazelnut skin (HS), which are known to have good antioxidant activity, were added into chicken nuggets in different ways. In the first method, the nuggets were coated with sodium alginate-calcium chloride-based coatings containing OLE and HS. In the second method, OLE and HS were directly added into the nugget patties. Nuggets that did not contain any additive (C1) and the samples prepared with the coating solution that did not include any additives (C2) were assigned as controls.

2. Nuggets were stored at two different temperatures, either in a refrigerator (4°C) or in a deep freezer (?18°C) for 21 days and 90 days respectively. Moisture content (%), pH, antioxidant status (TBARS), colour and microbial count (total mesophilic and psychrophilic aerobic bacteria) analyses were carried out during storage.

3. At the end of refrigerator storage (day 21), TBARS values for samples in which OLE and HS were directly added were found to be lower than those with OLE and HS coatings (P < 0.05). Total number of mesophilic and psychrophilic bacteria were found to be the lowest in the treatment in which HS was directly incorporated into nugget patty (P < 0.05).

4. For frozen samples, application of a coating containing OLE and HS and direct addition of HS into patties were found to be effective in reducing lipid oxidation. No microbial growth was determined in most of the samples stored in the deep freezer.  相似文献   
96.
97.
糖尿病足溃疡在糖尿病并发症中较为常见且具有高的致死率,引起国内外专家关注。随着研究的深入,中西医在临床中发现一类症状相似糖尿病足溃疡久治难愈,符合中医学的阴证疮面,故称糖尿病足溃疡阴证。要想对糖尿病足溃疡阴证的发病机制,病理特点和干预治疗等多方面有深入的了解,动物模型的建立为其提供可靠有效的途径。论文概括了前人对于糖尿病大鼠皮肤溃疡模型的进展,同时总结其阴证模型的优缺点和自己的经验与认识,以期对临床具有指导意义的糖尿病大鼠皮肤溃疡阴证模型。  相似文献   
98.
为探究WIF1(Wnt inhibitory factor 1)基因中WIF1-I8-sv889结构变异位点变异与皱皮香猪躯干被毛形成的关系,本试验采用冰冻组织切片观察皱皮香猪皮肤毛囊的组织学形态,采用PCR方法分析WIF1-I8-sv889位点在猪群中的分布频率,并通过在线软件UCSC、RegRNA 2.0对结构变异序列所含的功能元件进行分析。组织学研究显示,与正常香猪和大白猪皮肤相比,皱皮香猪毛囊毛根鞘伸入真皮层,形成棘突,且皱褶凹陷处毛囊聚集,相反皱褶凸起处毛囊较少;皱皮香猪皮肤毛囊中的毛球宽度显著增大(P<0.05),单个毛囊中的毛干数极显著增多(P<0.01)。在WIF1-I8-sv889结构变异断点两端设计特异性引物,扩增片段长1383 bp,与参考基因组比,1383 bp中889 bp为结构变异区间,缺失581 bp,倒置308 bp。群体分布结果显示,猪群中WIF1-I8-sv889位点呈现出丰富的多态性,检测到3种基因型:正常的Ⅱ型、杂合的DI型和缺失的DD型,皱皮香猪中未检测到Ⅱ型;与正常香猪和大白猪相比,皱皮香猪中D等位基因占优势(94.44%);经卡方检验,皱皮香猪D等位基因显著或极显著高于正常香猪和大白猪(P<0.05;P<0.01)。结果提示,WIF1基因中的WIF1-I8-sv889结构变异可能与皱皮香猪毛囊的形态发生有关。  相似文献   
99.
This study describes a novel end‐to‐end‐jejunojejunal‐anastomotic technique using skin staples following resection of compromised small intestine. Five horses were referred with colic and underwent exploratory laparotomy, resection and anastomosis. No long‐term complications were recorded at 12 months. This safe and effective technique may be used in equine gastrointestinal surgery.  相似文献   
100.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号