全文获取类型
收费全文 | 272篇 |
免费 | 32篇 |
专业分类
林业 | 17篇 |
农学 | 4篇 |
55篇 | |
综合类 | 16篇 |
农作物 | 9篇 |
水产渔业 | 14篇 |
畜牧兽医 | 162篇 |
园艺 | 1篇 |
植物保护 | 26篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 10篇 |
2017年 | 16篇 |
2016年 | 14篇 |
2015年 | 10篇 |
2014年 | 21篇 |
2013年 | 28篇 |
2012年 | 37篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 19篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 1篇 |
2000年 | 5篇 |
1998年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1990年 | 1篇 |
1979年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有304条查询结果,搜索用时 0 毫秒
301.
Flora Mückschel Elijah Ollo Stefanie P. Glaeser Rolf Düring Feng Yan Hermann Velten Ulf Theilen Michael Frei 《植物养料与土壤学杂志》2023,186(5):522-531
Background
Wastewater from sewage treatment plants contains high levels of nutrients, which can be used for plant nutrition. Classical wastewater treatment plants use complex microbial consortia of autotrophic and heterotrophic microorganisms for biological wastewater treatment. Certain autotrophic microalgae (e.g., species of the genera Chlorella, Scenedesmus, and Pediastrum) accumulate nutrients from wastewater very effectively.Aims
We investigated the potential of microalgae biomass obtained from a prototype wastewater treatment plant as a source of nutrients for crops, focusing on nitrogen.Methods
We provided wheat plants with different levels of algae biomass equivalent to 60, 120, and 180 kg N per hectare or with mineral fertilizer (N, P, and K) equivalent to the amounts contained in the algal biomass. Physiological and phenotypic traits were measured during growth, including vegetation indices, photosynthetic performance, growth, and nitrogen use efficiency (NUE). In addition, the adundances of Bacteria, Archaea and fungi and genes of ammonium oxidizing Bacteria and Archaea were determined in the rhizosphere of differently fertilized plants.Results
Microalgal application at fertilizer levels of 120 and 180 kg N ha–1 showed significantly improved physiological performance, growth, yield and nutrient uptake compared to the unfertilized control. Nevertheless, their yields and NUE were lower than with the application of equal amounts of mineral fertilization, while the adundance of rhizosphere microbes and ammonia-oxidizing microorganisms were not significantly affected.Conclusions
Microalgae from wastewater treatments form a suitable source of organic fertilizer for wheat plants with only moderate reductions in N use efficiency compared to mineral fertilizer. 相似文献302.
Constance Gebhardt Dr med vet ; Johannes Hirschberger Dr med vet DECVIM DECVCP ; Stefanie Rau Dr med vet ; Gisela Arndt Dr rer pol ; Karen Krainer ; Florian J. Schweigert Dr med vet ; Leo Brunnberg Dr med vet ; Bernd Kaspers Dr med vet Barbara Kohn Dr med vet DECVIM 《Journal of Veterinary Emergency and Critical Care》2009,19(5):450-458
Background – There is a high mortality rate in patients with systemic inflammatory response syndrome (SIRS) or sepsis. Therefore, an early diagnosis and prognostic assessment is important for optimal therapeutic intervention. The objective of the study was to evaluate if baseline values and changes in serum C-reactive protein (CRP) might predict survival in dogs with SIRS and sepsis.
Design – Prospective study; July 2004 to July 2005.
Setting – Small Animal Clinic, Berlin, Clinic of Small Animal Medicine, Munich.
Animals – Sixty-one dogs.
Measurements and Main Results – For the CRP analysis blood was drawn on day 0, 1, and 2; CRP was measured using a commercial ELISA test kit. Thirteen dogs suffered from nonseptic SIRS and 48 dogs from sepsis. The 14-day survival rate was 61% (69% nonseptic SIRS, 58% sepsis). Serum CRP was higher in sick dogs compared with controls ( P <0.001). Over the 3-day period surviving dogs ( n =31) displayed a significantly greater decrease in CRP than nonsurvivors ( n =10) ( P =0.001). No correlation was found between the initial CRP concentrations and the survival rate. The changes in CRP corresponded to the survival rate ( P =0.01).
Conclusion – There was no significant relationship between the survival rate in dogs with nonseptic SIRS or sepsis and the initial serum CRP concentrations. There was a correlation between decreasing CRP concentrations and recovery from disease. However, the changes in CRP concentrations over a 3-day period correctly predicted survival in 94% of dogs and death in 30% of the dogs (false positive rate 22%). 相似文献
Design – Prospective study; July 2004 to July 2005.
Setting – Small Animal Clinic, Berlin, Clinic of Small Animal Medicine, Munich.
Animals – Sixty-one dogs.
Measurements and Main Results – For the CRP analysis blood was drawn on day 0, 1, and 2; CRP was measured using a commercial ELISA test kit. Thirteen dogs suffered from nonseptic SIRS and 48 dogs from sepsis. The 14-day survival rate was 61% (69% nonseptic SIRS, 58% sepsis). Serum CRP was higher in sick dogs compared with controls ( P <0.001). Over the 3-day period surviving dogs ( n =31) displayed a significantly greater decrease in CRP than nonsurvivors ( n =10) ( P =0.001). No correlation was found between the initial CRP concentrations and the survival rate. The changes in CRP corresponded to the survival rate ( P =0.01).
Conclusion – There was no significant relationship between the survival rate in dogs with nonseptic SIRS or sepsis and the initial serum CRP concentrations. There was a correlation between decreasing CRP concentrations and recovery from disease. However, the changes in CRP concentrations over a 3-day period correctly predicted survival in 94% of dogs and death in 30% of the dogs (false positive rate 22%). 相似文献
303.
Large-scale biotechnological production of the antileukemic marine natural product sorbicillactone A
下载免费PDF全文
![点击此处可从《Marine drugs》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Bringmann G Gulder TA Lang G Schmitt S Stöhr R Wiese J Nagel K Imhoff JF 《Marine drugs》2007,5(2):23-30
In the search for novel bioactive compounds from sponge-derived microorganisms, we have recently identified two structurally and biosynthetically unprecedented fungal metabolites, the novel-type alkaloids sorbicillactone A and sorbicillactone B. Sorbicillactone A is active against leukemia cells without showing notable cytotoxicity. Therefore, we have developed an efficient process for its biotechnological production and isolation on a large scale supplying sufficient material for the ongoing preclinical investigations and structure-activity relationship (SAR) studies. 相似文献
304.
Anna Fickler Claudia Torno Stefanie Staats Gerald Rimbach Carsten Schulz 《Aquaculture Research》2019,50(8):2170-2180
Phytoestrogens are putatively able to enhance the biosynthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), but have also been shown to affect fish growth dose dependently. The aim of the present study was to identify a concentration for the phytoestrogen genistein and the phytoestrogen metabolite equol that further increases the endogenous biosynthesis of EPA and DHA without impairing fish growth. Juvenile rainbow trout (87.2 ± 0.3 g) were fed seven diets on a fixed ratio for 8 weeks. A vegetable oil‐based diet served as a control diet and was supplemented with equol (EQ) and genistein (G), respectively, at 0.1%, 0.2% and 0.3% of feed dry matter (1, 2 and 3). Growth and nutrient composition of whole body homogenates were not affected by dietary treatments. EPA and DHA levels in liver, fillet and whole body samples were not significantly increased by EQ and G diets. Fish fed EQ diets showed dose dependently increased liver weights and C18:0 liver levels, indicating estrogen‐like effects at increased dietary dosages. In conclusion, the utilization of equol and genistein in plant oil‐based diets in order to enhance the biosynthesis of EPA and DHA seems not reasonable in rainbow trout. 相似文献