全文获取类型
收费全文 | 147篇 |
免费 | 10篇 |
专业分类
林业 | 7篇 |
农学 | 5篇 |
9篇 | |
综合类 | 3篇 |
农作物 | 37篇 |
水产渔业 | 10篇 |
畜牧兽医 | 81篇 |
园艺 | 2篇 |
植物保护 | 3篇 |
出版年
2023年 | 3篇 |
2021年 | 3篇 |
2020年 | 9篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 15篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有157条查询结果,搜索用时 15 毫秒
101.
Won Ho Lee Seok Won Lee Tae Jin Kang Kwansoo Chung Jae Ryoun Youn 《Fibers and Polymers》2002,3(4):159-168
Polyurethane foams were produced by using a homogenizer as a mixing equipment. Effects of stirring speed on the foam structure
were investigated with SEM observations. Variation of the bubble size, density of the foam, compressive strength, and thermal
conductivity were studied. A hybrid foam consisting of polyurethane foam and commercial polystyrene foam is produced. Mechanical
and thermal properties of the hybrid foam were compared with those of pure polyurethane foam. Advancement of flow front during
mold filling was observed by using a digital camcorder. Four types of mold geometry were used for mold filling experiments.
Flow during mold filling was analyzed by using a two-dimensional control volume finite element method. Variation of foam density
with respect to time was experimentally measured. Creeping flow, uniform density, uniform conversion, and uniform temperature
were assumed for the numerical simulation. It was assumed for the numerical analysis that the cavity has thin planar geometry
and the viscosity is constant. The theoretical predictions were compared with the experimental results and showed good agreement. 相似文献
102.
Biodegradable nanocomposites were prepared by mixing a polymer resin and layered silicates by the melt intercalation method.
Internal structure of the nanocomposite was characterized by using the small angle X-ray scattering (SAXS) and transmission
electron microscope (TEM). Nanocomposites having exfoliated and intercalated structures were obtained by employing two different
organically modified nanoclays. Rheological properties in shear and extensional flows and biodegradability of nanocomposites
were measured. In shear flow, shear thinning behavior and increased storage modulus were observed as the clay loading increased.
In extensional flow, strain hardening behavior was observed in well dispersed system. Nanocomposites with the exfoliated structure
had better biodegradability than nanocomposites with the intercalated structure or pure polymer. 相似文献
103.
Jeong-Hyun Yoon Nayoung Lee Kumju Youn Mi Ra Jo Hyeung-Rak Kim Dong-Seok Lee Chi-Tang Ho Mira Jun 《Marine drugs》2021,19(3)
The proteolytic processing of amyloid precursor protein (APP) by β-secretase (BACE1) and γ-secretase releases amyloid-β peptide (Aβ), which deposits in amyloid plaques and contributes to the initial causative events of Alzheimer’s disease (AD). In the present study, the regulatory mechanism of APP processing of three phlorotannins was elucidated in Swedish mutant APP overexpressed N2a (SweAPP N2a) cells. Among the tested compounds, dieckol exhibited the highest inhibitory effect on both intra- and extracellular Aβ accumulation. In addition, dieckol regulated the APP processing enzymes, such as α-secretase (ADAM10), β-secretase, and γ-secretase, presenilin-1 (PS1), and their proteolytic products, sAPPα and sAPPβ, implying that the compound acts on both the amyloidogenic and non-amyloidogenic pathways. In addition, dieckol increased the phosphorylation of protein kinase B (Akt) at Ser473 and GSK-3β at Ser9, suggesting dieckol induced the activation of Akt, which phosphorylated GSK-3β. The specific phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 triggered GSK-3β activation and Aβ expression. In addition, co-treatment with LY294002 noticeably blocked the effect of dieckol on Aβ production, demonstrating that dieckol promoted the PI3K/Akt signaling pathway, which in turn inactivated GSK-3β, resulting in the reduction in Aβ levels. 相似文献
104.
Jong-Tai Kim Jong-Yeol Park Hun-Su Seo Hwa-Gyun Oh Jae-Wuk Noh Jae-Hoon Kim Dae-Yong Kim Hee-Jeong Youn 《Veterinary parasitology》2002,103(1-2):53-63
Neospora caninum is an intracellular apicomplexan parasite that infects a wide range of mammals and has been associated with abortion in cattle worldwide. Artemisinin is an effective antimalarial compound derived from a traditional Chinese herbal remedy, qinghao or Artemisia annua L. In the study reported, the cultured host cells (vero cells or mouse peritoneal macrophages) infected with N. caninum tachyzoites were incubated with alpha-MEM (minimal essential medium) 10%HS supplemented with various concentration or artemisinin (20, 10, 1, 0.1 and 0.01 microg/ml) to examine the efficacy of artemisinin against N. caninum tachyzoites intracellular multiplication. In long-term studies, at 20 or 10 microg/ml for 11 days, artemisinin reduced N. caninum and completely eliminated all microscopic foci of N. caninum. At 1 microg/ml for 14 days, artemisinin reduced N. caninum and completely achieved elimination of all microscopic foci of N. caninum. There was no apparent toxicity to host cells in long-term studies. In short-term studies, at > or = 0.1microg/ml, artemisinin reduced N. caninum tachyzoites intracellular multiplication, significantly (P < 0.05) and appeared to depend on the artemisinin concentrations. Pretreatment of host cells or N. caninum tachyzoites with artemisinin had no effect on N. caninum tachyzoites intracellular multiplication. These results demonstrate that artemisinin inhibited N. caninum tachyzoites intracellular multiplication. 相似文献
105.
Mohamed Rhouma Alexander de Oliveira El Warrak Eric Troncy Francis Beaudry Younès Chorfi 《Canadian journal of veterinary research》2013,77(3):191-198
There is evidence that vitamin E (VE) has anti-inflammatory and analgesic properties in human osteoarthritis (OA). This double-blinded and randomized pilot study used a broad spectrum of clinical and laboratory parameters to investigate whether such beneficial effects could be detected in a canine experimental OA model. Dogs were divided into 2 groups: control (n = 8), which received a placebo, and test group (n = 7), which received 400 IU/animal per day of VE for 55 d, starting the day after transection of the cranial cruciate ligament. Lameness and pain were assessed using a visual analogue scale (VAS), numerical rating scale (NRS), and electrodermal activity (EDA) at day 0, day 28, and day 55. Cartilage and synovial inflammation lesions were assessed. One-side comparison was conducted at an alpha-threshold of 10%. At day 56, dogs were euthanized and concentrations of prostaglandin E2 (PGE2), nitrogen oxides (NOx), and interleukin-1 beta (IL-1β) were measured in synovial fluid. Concentrations of NOx and PGE2 in synovial fluid were lower in the test group (P < 0.0001 and P = 0.03, respectively). Values of VAS, NRS, and EDA showed a consistent trend to be lower in the test group than in the control, while statistical significance was reached for VAS at day 55 and for EDA at day 28 (adjusted P = 0.07 in both cases). Histological analyses of cartilage showed a significant reduction in the scores of lesions in the test group. This is the first time that a study in dogs with OA using a supplement with a high dose of vitamin E showed a reduction in inflammation joint markers and histological expression, as well as a trend to improving signs of pain. 相似文献
106.
Joo Youn Oh Mee Kum Kim Hyun Ju Lee Jung Hwa Ko Won Ryang Wee Jin Hak Lee 《Veterinary ophthalmology》2009,12(Z1):50-56
Objective Although variations exist between species with respect to outcomes after cryopreservation, little is known about the differences in the susceptibility of the corneal stroma to cryoinjury. We performed this study to investigate freeze–thaw‐induced damage in keratocytes and collagen in rabbit, pig, and human corneas. Animals studied Rabbit, pig, and human. Procedures We prepared 250‐μm‐thick anterior stroma from rabbit, pig, and human corneas after scraping off the epithelium and endothelium. Each 250‐μm‐thick corneal stroma without epithelium was placed in a 50‐mL tube, frozen with liquid N2 for 15 min and taken out to thaw rapidly at 37 °C. This procedure of rapid freezing and thawing was repeated three times. Differences between the species with respect to cells and collagen structures were examined using hematoxylin–eosin (H&E) staining, terminal deoxynucleotidyl transferase‐mediated nick end labeling (TUNEL) assay, and transmission electron microscopy (TEM). We orthotopically transplanted the pig and rabbit corneal transplants after the triple freeze–thaw cycle into rabbit eyes and evaluated graft survival. Results On gross examination, rabbit corneas became opaque after the triple freeze–thaw procedure, while pig and human corneas remained transparent. Histologically, keratocytes were apoptotic on TUNEL assay and TEM in rabbit, pig, and human corneas. Collagen fibrils were fragmented and the arrangement of collagen fibrils was severely disturbed in rabbit corneas on H&E staining and TEM; collagen was well preserved in pig and human corneas. Rabbit corneal stroma underwent autolysis after transplantation, whereas the pig corneal stroma remained clear for 1 month. Conclusions Our study showed that rabbit corneal stroma was more susceptible to freeze–thaw injury than pig and human corneas. 相似文献
107.
108.
Eui-Hwa Nam Seol-Hee Park Ji-Young Jung Seung-Hee Han Hwa-Young Youn Jun-Seok Chae Cheol-Yong Hwang 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(2):187-191
The purpose of this study was to evaluate the effects of a topical spray containing 0.0584% hydrocortisone aceponate (HCA) on canine atopic dermatitis (CAD) and to evaluate the skin barrier function during the treatment of CAD. Twenty-one dogs that fulfilled the diagnostic criteria for CAD were included in this study. The HCA spray was applied once a day to the lesions of all dogs for 7 or 14 days. Clinical assessment was performed before (day 0) and after treatment (day 14), and clinical responses were correlated with changes in skin barrier function. CAD severity significantly decreased after 14 days of HCA treatment based on the lesion scores (p < 0.0001), which were determined using the CAD extent and severity index (CADESI-03) and pruritus scores (p < 0.0001) calculated using a pruritus visual analog scale. Transepidermal water loss, a biomarker of skin barrier function, was significantly reduced compared to baseline (day 0) measurements (p = 0.0011). HCA spray was shown to be effective for significantly improving the condition of dogs suffering from CAD. This treatment also significantly improved cutaneous hydration and skin barrier function in the animals. 相似文献
109.
Jung JW Park JS Hwang JW Kang KS Lee YS Song BS Lee GJ Yeo CD Kang JS Lee WS Jeon KS Um CH Kim YS Oh MJ Youn JP Li P Park JE Hwang SY 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(11):1329-1333
The recent DNA microarray technology enables us to understand a large number of gene expression profiling. The technology has potential possibility to comprehend mechanism of multiple genes were related to compounds which have toxicity in biological system. So, the toxicogenomics through this technology may be very powerful for understanding the effect of unknown toxic mechanisms in biological system. We have studied that the effect of compounds related to hepatotoxin in vivo system using DNA microarray and classified chemicals which have been well characterized. We have studied three compounds; 2 peroxisome proliferators: Clofibrate (ethyl-p-chlorophenoxyisobutyrate), gemfibrozil (5-2[2,5-dimethyl-phenoxy]2-2-dimethyl-pentanonic), and an antiepileptic drug: phenytoin (5,5-diphenylhydantoin). Male Sprague-Dawely VAF(+) albino rats of 5-6 weeks old were treated with each compound for 24 hr and 2 weeks. 4.8 K cDNA microarray in house has been used for gene expression profiling. We found that the clustering of gene expression had similarity like as the toxic phenotype of compounds. 相似文献
110.