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   38篇
  免费   2篇
林业   7篇
农学   1篇
  6篇
农作物   8篇
水产渔业   6篇
畜牧兽医   8篇
园艺   1篇
植物保护   3篇
  2023年   1篇
  2022年   1篇
  2021年   5篇
  2020年   1篇
  2019年   5篇
  2018年   2篇
  2017年   7篇
  2016年   1篇
  2015年   1篇
  2014年   3篇
  2013年   3篇
  2012年   2篇
  2011年   2篇
  2010年   1篇
  2008年   1篇
  2007年   2篇
  2004年   1篇
  1992年   1篇
排序方式: 共有40条查询结果,搜索用时 109 毫秒
31.
Physico-mechanical and antioxidant properties of glycerol plasticized fish gelatin films were investigated at different levels of fish protein hydrolysates (FPH) from silver carp muscle (5, 10, 15, and 20 g FPH/100 g gelatin). The films supplemented with FPH, especially at higher concentration showed significant increase in 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 20-azinobis-(3-ethylbenzothiazoline-6-sulfnic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP), elongation at break, difference of color, water vapor permeability and opacity, while tensile strength, elastic modulus, L*, b*, and contact angle decreased markedly (p < 0.05). However, no significant differences were observed for a* and solubility of all samples (p > 0.05). Films prepared using 20% FPH had lower glass transition temperature and more homogeneous structure, compared with control film. Also, Fourier transform infrared (FTIR) spectroscopy confirmed the increase of free groups of hydrolysates and lower interaction between chains of film incorporated with the highest content of FPH. Thus, these results indicate that FPH enhanced the antioxidant activities and affected some characteristics due to less interaction between gelatin and FPH.  相似文献   
32.
Lysozyme levels in the head kidney, spleen and liver tissues of the male and female Caspian kutum (Rutilus frisii kutum) were measured under monthly temperature variations and gonadal growth. The lysozyme content in all tissues of the male and female of the Caspian kutum showed almost a significant decreasing trend from October to March, coinciding with the lowest sea surface temperature and afterwards, it increased in April and May. In vitellogenic stage of the ovarian growth, the lysozyme level decreased in all three tissues and then increased significantly in the spawning stage. Over testicular growth, lysozyme level showed no remarkable variations from the early maturing to developed stages but increased in the spermiation stage. The regularity of lysozyme level in both sexes of the Caspian kutum was liver>spleen>head kidney. The effectiveness ratio (partial Eta2) of temperature and gonadal growth in the lysozyme variations showed that temperature factor was more highlight than gonadal growth. In conclusion, the liver similar to the kidney and spleen plays an essential role against pathogen as an organ of lysozyme producing in the Caspian kutum. In addition, the female lysozyme level was higher than the male in all studied tissues.  相似文献   
33.
IpaA, IpaB, IpaC, and IpaD are Shigella dysenteriae Ipa operon genes which collectively contribute in invasion to the epithelial cells of the human gut. Among them, IpaD has been demonstrated to play the most crucial role in shigellosis. Noteworthy, due to the more efficient, cost-effective and no need for advanced equipment in comparison with traditional systems, plant-based expression systems are considered as a novel strategy for production of recombinant proteins. As an aim of this research, attempts were carried out to examine and compare IpaD antigen production in three different plant-based platforms, including transgenic tobacco hairy roots and leaves as well as a transient based expression. Furthermore, different signal peptides (i.e. Zera® and Extensin) were also employed in order to improve the production level. Based on TAS-ELISA result, the highest yield of IpaD acquired by ER-derived protein bodies (Zera® ) which was more than 1.29-fold higher as compared with apoplastic space based on TSP% in both transgenic tobacco hairy roots and leaves. Furthermore, transgenic tobacco hairy roots were more abundant than transgenic leaves averaging 0.52 ng of IpaD per μg TSP and with a maximum of 0.94 ng IpaD per μg TSP in the best-performing construct of pBI-ZeCIpaD. Totally, the results of quantitative RT-PCR and TAS-ELISA indicated that the best time point for the production of IpaD using agroinfiltration was 72 h post infiltration and during 72 to 96 hpi, expression levels descended rapidly. To the best of our knowledge, this is the first report representing and combining the potential effects of signal peptides and plant-based expression platforms on stably production of IpaD antigen in transgenic tobacco leaves and hairy roots.  相似文献   
34.
A field experiment was arranged in split plot based on randomized complete block design in three replications at Moghan plain, Iran, during the years 2014–2016. Treatments included four irrigation levels, 100%, 80%, 60%, and 40% of water requirements for the main plot, and tomato cultivars included for a subplot. Results indicated that deficit irrigation resulted in a decrease in yield and yield components, morphological characteristics and water use efficiency (WUE), and volumetric soil moisture in different layers of soil, while resulting in an increase in qualitative characteristics. Reductions of tomato fruit yield and other studied traits were different in the first and second agronomic years. But in general, comparison of means showed that, based on the normal irrigation, optimal growth and plant growth were observed for 08 cultivar. Moreover, under deficit irrigation conditions, Superbita cultivar exhibited higher yield and WUE compared to 08 and Matin cultivars.

Abbreviations: WUE = Water use efficiency; IWUE = Irrigation water use efficiency; K = Kelvin; IR = Irrigation water; Cul = Cultivar; ETo = Reference evapotranspiration; Etc = Evapotranspiration; Kc = Crop coefficient; Kp = Pan coefficient; cm = Centimeter; gr = Gram; t = Tone; ha = Hectare; ? = Volumetric water content; kg = kilogram.  相似文献   
35.
As the dominant macrofauna in many soils, earthworms play a significant role in mineral weathering and nutrient release from mineral structures into available forms for root uptake. Phlogopite is a trioctahedral micaceous mineral that can be weathered to other minerals through release of its interlayer potassium (K). In this study, we investigated the effect of earthworm activities and associated microbial communities on phlogopite weathering during the production of phlogopite-enriched vermicompost with different quantities of phlogopite added. An experiment was run under laboratory conditions using three levels of phlogopite (0, 20% and 40% by weight) in triplicates. Each Petri dish contained 20 g of a mixture of cow manure and phlogopite, and vermicomposting process was performed by inoculation of eight Eisenia foetida earthworms. Changes in clay mineralogy and C/N ratio in each dish were assessed at days 0, 45, 90, 135, and 180 during vermicomposting. The results indicated that phlogopite was partially weathered to vermiculite and interstratified mica-vermiculite during the vermicomposting process. The rate of weathering was higher during the early stages of vermicomposting (the first 90 d). The weathering of phlogopite was influenced considerably by the activity of earthworms and associated microbial communities during the organic matter transformation process. At the early stages of the process, the weathering rate for different levels of phlogopite was not significantly different, but over time it accelerated steadily, and the difference increased.  相似文献   
36.
Plant Foods for Human Nutrition - Prebiotics are regarded as the non-digestible food constituents that are selectively consumed by health-promoting bacteria (probiotics). In fact, a number of...  相似文献   
37.
The renewable, proteinaceous, marine biopolymer spongin is yet the focus of modern research. The preparation of a magnetic three-dimensional (3D) spongin scaffold with nano-sized Fe3O4 cores is reported here for the first time. The formation of this magnetic spongin–Fe3O4 composite was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA) (TGA-DTA), vibrating sample magnetometer (VSM), Fourier-transform infrared spectroscopy (FTIR), and zeta potential analyses. Field emission scanning electron microscopy (FE-SEM) confirmed the formation of well-dispersed spherical nanoparticles tightly bound to the spongin scaffold. The magnetic spongin–Fe3O4 composite showed significant removal efficiency for two cationic dyes (i.e., crystal violet (CV) and methylene blue (MB)). Adsorption experiments revealed that the prepared material is a fast, high-capacity (77 mg/g), yet selective adsorbent for MB. This behavior was attributed to the creation of strong electrostatic interactions between the spongin–Fe3O4 and MB or CV, which was reflected by adsorption mechanism evaluations. The adsorption of MB and CV was found to be a function of pH, with maximum removal performance being observed over a wide pH range (pH = 5.5–11). In this work, we combined Fe3O4 nanoparticles and spongin scaffold properties into one unique composite, named magnetic spongin scaffold, in our attempt to create a sustainable absorbent for organic wastewater treatment. The appropriative mechanism of adsorption of the cationic dyes on a magnetic 3D spongin scaffold is proposed. Removal of organic dyes and other contaminants is essential to ensure healthy water and prevent various diseases. On the other hand, in many cases, dyes are used as models to demonstrate the adsorption properties of nanostructures. Due to the good absorption properties of magnetic spongin, it can be proposed as a green and uncomplicated adsorbent for the removal of different organic contaminants and, furthermore, as a carrier in drug delivery applications.  相似文献   
38.
This study assesses the effects of ginger on nausea and vomiting caused by pregnancy and compares it with metoclopramide medicine. This study was a randomized double-blind controlled trial. Metoclopramide, Ginger and placebo were putted in similar capsules. The medicines were administered three times a day. Then the Rhodes questionnaire was completed and its score were calculated. Data were analyzed by Chi square test, ANOVA and Repeated measurement. The intensity of changes in nausea, vomiting and Rhodes during study were statistically different in two groups of ginger and metoclopramide compared with placebo (p < 0.05), but it was not statistically significant between two groups of ginger and metoclopramide. According to our study, ginger is less effective than metoclopramide in reducing nausea and vomiting but it could be a good alternative for metoclopramide.  相似文献   
39.
To investigate the efficiency of hCG/CIDR after breeding to increase the reproductive performance, 35 synchronized ewes were mated with fertile rams and were assigned to three treatment groups. Ewes in hCG group (n?=?12) received 400 IU hCG on day 11 post-mating, and ewes in CIDR group (n?=?11) received CIDR from day 7 until day 19 post-mating. Ewes in the control group (n?=?12) did not receive any treatment. Blood samples were collected on days 7, 12, 17, and 22 post-mating. Plasma P4 concentrations were higher on days 12 and 17 post-mating in hCG- and CIDR-treated groups (P?<?0.05). However, the concentrations of P4 on day 22 post-mating in hCG and control groups were higher than that in CIDR group (P?<?0.05). Ewes in hCG group produced more quadruplets (P?<?0.05) and triplets, and as a result, they had a larger litter size (P?<?0.05). The lamb mortality rate by weaning in hCG group (3.6%) was less than that in control (11.8%; P?<?0.05) and CIDR (9.1%; P?>?0.05) groups. Post-mating administration of hCG or CIDR did not affect the lamb birth weight in single and quadruplet births (P?>?0.05), but the birth weight of twin lambs was higher in the hCG and CIDR groups (P?<?0.05). Weaning weights of twin lambs were higher in the hCG and CIDR groups (P?<?0.05). In conclusion, hCG/CIDR administration post-mating increased the maternal P4 concentrations and enhanced reproductive performance.  相似文献   
40.
Landscape Ecology - Lacunarity as a scale-dependent measure of spatial heterogeneity has received great attention in landscape ecology. Most lacunarity measures have been obtained from greyscale or...  相似文献   
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