全文获取类型
收费全文 | 654篇 |
免费 | 31篇 |
专业分类
林业 | 32篇 |
农学 | 21篇 |
基础科学 | 1篇 |
112篇 | |
综合类 | 49篇 |
农作物 | 103篇 |
水产渔业 | 52篇 |
畜牧兽医 | 228篇 |
园艺 | 8篇 |
植物保护 | 79篇 |
出版年
2023年 | 2篇 |
2022年 | 15篇 |
2021年 | 18篇 |
2020年 | 21篇 |
2019年 | 18篇 |
2018年 | 16篇 |
2017年 | 23篇 |
2016年 | 21篇 |
2015年 | 20篇 |
2014年 | 32篇 |
2013年 | 37篇 |
2012年 | 41篇 |
2011年 | 50篇 |
2010年 | 29篇 |
2009年 | 21篇 |
2008年 | 42篇 |
2007年 | 38篇 |
2006年 | 33篇 |
2005年 | 31篇 |
2004年 | 33篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 11篇 |
2000年 | 16篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1994年 | 3篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 3篇 |
1964年 | 2篇 |
1963年 | 2篇 |
1956年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有685条查询结果,搜索用时 15 毫秒
51.
Woochul Chang Chang Youn Lee Jun-Hee Park Moon-Seo Park Lee-So Maeng Chee Soon Yoon Min Young Lee Ki-Chul Hwang Yong-An Chung 《Journal of veterinary science (Suw?n-si, Korea)》2013,14(1):69-76
The use of mesenchymal stem cells (MSCs) has emerged as a potential new treatment for myocardial infarction. However, the poor viability of MSCs after transplantation critically limits the efficacy of this new strategy. The expression of microRNA-210 (miR-210) is induced by hypoxia and is important for cell survival under hypoxic conditions. Hypoxia increases the levels of hypoxia inducible factor-1 (HIF-1) protein and miR-210 in human MSCs (hMSCs). miR-210 positively regulates HIF-1α activity. Furthermore, miR-210 expression is also induced by hypoxia through the regulation of HIF-1α. To investigate the effect of miR-210 on hMSC survival under hypoxic conditions, survival rates along with signaling related to cell survival were evaluated in hMSCs over-expressing miR-210 or ones that lacked HIF-1α expression. Elevated miR-210 expression increased survival rates along with Akt and ERK activity in hMSCs with hypoxia. These data demonstrated that a positive feedback loop involving miR-210 and HIF-1α was important for MSC survival under hypoxic conditions. 相似文献
52.
53.
In the nine years from 1993 to 2001, 210 cases of rabies were recorded in domestic animals in South Korea; 115 cattle, 94 dogs and one farmed deer were affected. The annual incidence of rabies cases increased to a peak of 64 in 1998, and then decreased to about 30 cases per year. The cases were confined to the northern part of Kyounggi and Kangwon provinces. One hundred and forty-six cases (69.5 per cent) occurred in Kyounggi and 64 cases (30.5 per cent) in Kangwon province, and about 82 per cent of them were confined to two counties in Kyounggi province (29 per cent in Paju and 28.1 per cent in Younchun) and to Chulwon county in Kangwon province (25.2 per cent). However, over several years the outbreaks gradually moved south and east in both Kyounggi and Kangwon provinces. There were more rabies cases in cattle than in dogs, suggesting that the disease is transmitted by the sylvatic cycle. To investigate the relationship between rabies in domestic animals and wild animals, 107 wild animals, including Korean raccoon dogs, badgers, weasels and feral cats, were tested for rabies; 21 of the 67 Korean raccoon dogs tested (31 per cent) were infected. The cases in domestic animals were most common in winter, from December to February, and least common in summer, from June to September. 相似文献
54.
Tripathi GR Park J Park Y Hwang I Park Y Hahm KS Cheong H 《Journal of agricultural and food chemistry》2006,54(22):8437-8443
A PVYO virus-resistant potato (Solanum tuberosum L. cv. Golden Valley) was identified, and further, from its tubers, a small (5.57 kDa) antiviral peptide potide-G was isolated. Application of potide-G on virus susceptible potato (cv. Winter valley) expressed robust resistance to PVYO infection and showed no virus infected morphology. We found that PVYO infection spreads up completely within 3 days post inoculation (dpi) in susceptible cultivar. PVYO was more accumulated toward the basal leaves, when infection occurred longer. Combined results of morphology of PVYO infection, ELISA, RT-PCR, and real-time PCR showed the resistance to the PVYO infection depends on the expression of Ry gene. Indeed, the real-time PCR result showed that the Ry gene up-regulated to 3 times higher in PVYO infected cv. Golden valley. Golden crude protein was found to be active against PVYO infection in the in vivo test. In addition, application of potide-G in a virus susceptible potato potently reduced the viral infection actively with 50 times lower concentration than that of the Golden protein. Further identification of a host-specific resistant gene in a plant and the peptide derived from it offers new opportunities for the development of novel bio-pesticides against plant virus. 相似文献
55.
Lee KT Byun MJ Kang KS Hwang H Park EW Kim JM Kim TH Lee SH 《Journal of animal science》2012,90(4):1081-1087
This study was carried out to identify SNP associated with fatness traits on pig chromosome 6. In total, 11,067 putative genomic variations were detected in 125 complete bacterial artificial chromosome sequences corresponding to the region between SW2098 and SW1881, which harbors multiple QTL affecting intramuscular fat content (IMF) and backfat thickness (BFT). Among 173 putative SNP validated by MassArray, 120 SNP were used in an association study on 541 offspring produced by a cross of Korean native pig and Landrace breeds. The significance level of each SNP was determined using single marker regression analysis. Further, significant threshold values were determined using a false discovery rate. Nine out of 120 SNP showed significant effects on BFT or IMF or both. Of the 9 significant SNP, 4 were significantly associated with IMF, 7 were significantly related to BFT, and 2 SNP (Kps8172 and Kps6413) showed significant effects on both traits. Moreover, multiple regression analysis considering all significant SNP was used to correct spurious false positives due to linkage disequilibrium. Consequently, only 1 SNP (Kps6413) was significant for IMF, whereas 4 SNP including Kps6413 showed significant effects on BFT. The significant SNP had generally additive effects and on average explained 1.72% of the genetic variation for IMF and 3.92% for BFT, respectively. These markers can potentially be applied in pig breeding programs for improving IMF and BFT traits after validation in other populations. 相似文献
56.
Rees EE Merrill EH Bollinger TK Hwang YT Pybus MJ Coltman DW 《Preventive veterinary medicine》2012,104(1-2):149-159
Chronic wasting disease (CWD) is a fatal disease of North American cervids that was first detected in a wild, hunter-shot deer in Saskatchewan along the border with Alberta in Canada in 2000. Spatially explicit models for assessing factors affecting disease detection are needed to guide surveillance and control programs. Spatio-temporal patterns in CWD prevalence can be complicated by variation in individual infection probability and sampling biases. We assessed hunter harvest data of mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) during the early phases of an outbreak in Saskatchewan (i.e., 2002-2007) for targeting the detection of CWD by defining (1) where to look, and (2) how much effort to use. First, we accounted for known demographic heterogeneities in infection to model the probability, P(E), that a harvested deer was infected with CWD given characteristics of the harvest location. Second, in areas where infected deer were harvested we modelled the probability, P(D), of the hunter harvest re-detecting CWD within sample units of varying size (9-54 km(2)) given the demographics of harvested deer and time since first detection in the study area. Heterogeneities in host infection were consistent with those reported elsewhere: mule deer 3.7 times >white-tailed deer, males 1.8 times>females, and quadratically related to age in both sexes. P(E) increased with number of years since the first detection in our study area (2002) and proximity to known disease sources, and also varied with distance to the South Saskatchewan River and small creek drainages, terrain ruggedness, and extent of agriculture lands within a 3 km radius of the harvest. The majority (75%) of new CWD-positive deer from our sample were found within 20 km of infected deer harvested in the previous year, while approximately 10% were greater than 40 km. P(D) modelled at 18 km(2) was best supported, but for all scales, P(D) depended on the number of harvested deer and time since the first infected deer was harvested. Within an 18 km(2) sampling unit, there was an 80% probability of detecting a CWD-positive deer with 16 harvested deer five years after the initial infected harvest. Identifying where and how much to sample to detect CWD can improve targeted surveillance programs early in the outbreak of the disease when based on hunter harvest. 相似文献
57.
Ji-young Jung Eui-hwa Nam Seol-hee Park Seung-hee Han Cheol-yong Hwang 《Journal of veterinary science (Suw?n-si, Korea)》2013,14(2):199-205
In humans, skin barrier dysfunction is thought to be responsible for enhanced penetration of allergens. Similar to conditions seen in humans, canine atopic dermatitis (CAD) is characterized by derangement of corneocytes and disorganization of intercellular lipids in the stratum corenum (SC) with decreased ceramide levels. This study was designed to evaluate the effects of a moisturizer containing ceramide on dogs with CAD. Dogs (n = 20, 3~8 years old) with mild to moderate clinical signs were recruited and applied a moisturizer containing ceramide for 4 weeks. Transepidermal water loss (TEWL), skin hydration, pruritus index for canine atopic dermatitis (PICAD) scores, and canine atopic dermatitis extent and severity index (CADESI) scores of all dogs were evaluated. Skin samples from five dogs were also examined with transmission electron microscopy (TEM) using ruthenium tetroxide. TEWL, PICAD, and CADESI values decreased (p < 0.05) and skin hydration increased dramatically over time (p < 0.05). Electron micrographs showed that the skin barrier of all five dogs was partially restored (p < 0.05). In conclusion, these results demonstrated that moisturizer containing ceramide was effective for treating skin barrier dysfunction and CAD symptoms. 相似文献
58.
PH Hong YD Su JH Su YH Chen TL Hwang CF Weng CH Lee ZH Wen JH Sheu NC Lin YH Kuo PJ Sung 《Marine drugs》2012,10(5):1156-1168
Two new briarane diterpenoids, briarenolides, F (1) and G (2), were isolated from an octocoral identified as Briareum sp. The structures of briaranes 1 and 2 were established by spectroscopic methods and by comparison of the spectroscopic data with those of known briarane analogues. Briarenolide F was proven to be the first 6-hydroperoxybriarane derivative and this compound displayed a significant inhibitory effect on the generation of superoxide anion by human neutrophils. 相似文献
59.
Chih-Yang Liu Tsong-Long Hwang Mei-Ru Lin Yung-Husan Chen Yu-Chia Chang Lee-Shing Fang Wei-Hsien Wang Yang-Chang Wu Ping-Jyun Sung 《Marine drugs》2010,8(7):2014-2020
A new bioactive sterol glycoside, 3β-O-(3′,4′-di-O-acetyl-β-d-arabinopyranosyl) -25ξ-cholestane-3β,5α,6β,26-tetrol-26-acetate) (carijoside A, 1), was isolated from an octocoral identified as Carijoa sp. The structure of glycoside 1 was established by spectroscopic methods and by comparison with spectral data for the other known glycosides. Carijoside A (1) displayed significant inhibitory effects on superoxide anion generation and elastase release by human neutrophils and this compound exhibited moderate cytotoxicity toward DLD-1, P388D1, HL-60, and CCRF-CEM tumor cells. 相似文献
60.
Shyh-Shin Hwang Yu-Che Cheng Chen Chang Huu-Sheng Lur Ta-Te Lin 《Journal of Cereal Science》2009,50(1):36-42
This research involved a magnetic resonance imaging (MRI) technique that was applied to examine water distribution and migration in single rice kernels during the tempering process. The imaging experiments were performed in a Bruker 9.4T MRI system. Three-dimensional spin-echo (SE) imaging sequences were optimized by adjusting the scanning parameters of echo time (TE) and repetition time (TR) to obtain images with maximum contrast. The MR images showed that the moisture distribution in the rice kernel is non-uniform and compartmental. The embryo region exhibited much higher MR signal intensity than the starchy endosperm portion. The tempering process was analyzed with spatial-temporal signal intensities of the endosperm following the drying process of the rice kernel. The transient change of the signal intensities in the endosperm was well fitted with a double exponential function suggesting that both convection and diffusion contributed to the reduction of the moisture gradient within the rice kernel during tempering. This hypothesis was further supported by the experimental data of the insulated rice kernel whose convective mass transfer was excluded. The experimental results revealed that MR imaging of rice kernels could be used as an efficient tool to examine the mechanisms of moisture migration within cereal grains. 相似文献