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排序方式: 共有210条查询结果,搜索用时 62 毫秒
31.
Jinhaeng Song Ju-eun Jeon Tae Hyung Won Chung J. Sim Dong-Chan Oh Ki-Bong Oh Jongheon Shin 《Marine drugs》2014,12(5):2760-2770
Two new peptides, chujamides A (1) and B (2), were isolated from the marine sponge Suberites waedoensis, which was collected from Korean waters. Based upon the results of the combined spectroscopic analyses, the structures of these compounds were determined to be proline-riched and cyclic cystine bridged dodeca- and undecapeptides. The absolute configurations of all amino acid residues were determined to be l by advanced Marfey’s analysis. The new compounds exhibited weak cytotoxicities against A549 and K562 cell-lines, and compound 2 also demonstrated moderate inhibitory activity against Na+/K+-ATPase. 相似文献
32.
Kyuho Moon Chan-Hong Ahn Yoonho Shin Tae Hyung Won Keebeom Ko Sang Kook Lee Ki-Bong Oh Jongheon Shin Seung-Il Nam Dong-Chan Oh 《Marine drugs》2014,12(5):2526-2538
Two new secondary metabolites, arcticoside (1) and C-1027 chromophore-V (2), were isolated along with C-1027 chromophore-III and fijiolides A and B (3–5) from a culture of an Arctic marine actinomycete Streptomyces strain. The chemical structures of 1 and 2 were elucidated through NMR, mass, UV, and IR spectroscopy. The hexose moieties in 1 were determined to be d-glucose from a combination of acid hydrolysis, derivatization, and gas chromatographic analyses. Arcticoside (1) and C-1027 chromophore-V (2), which have a benzoxazine ring, inhibited Candida albicans isocitrate lyase. Chromophore-V (2) exhibited significant cytotoxicity against breast carcinoma MDA-MB231 cells and colorectal carcinoma cells (line HCT-116), with IC50 values of 0.9 and 2.7 μM, respectively. 相似文献
33.
Jeong Ho Song Tae Jo Kang Young Don Cho Sun Hyoung Lee Jeong Soo Kim 《Fibers and Polymers》2006,7(3):217-222
Propargyl alcohol was coupled to 2,4-hexadiyne-1,6-diol (HDD) and crystallized in the process of ultraviolet irradiation-induced
topochemical polymerization. The HDD polymer crystals were used as one component in the fabrication of organic photovoltaic
cells, in combination with fullerene as the electron acceptor. The various structures of the produced photovoltaic cells included
bilayer, trilayer, and bulk heterojunction structures. Their photovoltaic properties were analyzed in relation to crystal
structure, electrochemical properties, and band structure of the HDD polydiacetylene polymers. 相似文献
34.
Tae Keun Cho Mi Hwa Chong Byoung Chul Chun Hye Ran Kim Yong-Chan Chung 《Fibers and Polymers》2007,8(1):7-12
Polyurethane block copolymers chemically cross-linked by pentaerythritol, a four-way cross-linker, are tested for the shape
memory effect. One of the copolymers shows higher shape recovery than any other shape memory copolymer synthesized by us so
far. The copolymer maintains a surprising 94 % shape recovery after the third cyclic test. The four-way cross-linking by pentaerythritol
and interaction between hard segments are mainly responsible for the very high shape recovery. Tensile mechanical properties
also significantly improve by cross-linking. Glass transition temperature (T
g
) slightly increases with cross-linking content. Other characterization such molecular weight, IR, and X-ray diffraction is
also carried out to understand the arrangement of copolymer chains. 相似文献
35.
A series of shape memory polyurethane (PU) copolymers synthesized from 1,4-phenyldiisocyanate (PDI), poly(tetramethyleneglycol)
(PTMG), 1,4-butanediol (BD) as a chain extender, and glycerol as a cross-linking agent were tested for the mechanical properties
and the shape memory effect at the temperature 20 °C above melting temperature (T
m), and were compared with other PUs synthesized from 4,4′-methylene-bis-phenyldiisocyanate (MDI), PTMG, and BD. Mechanical
properties and shape memory effect were improved substantially by adopting both PDI and glycerol. Interestingly, enthalpy
of melting and T
m were not affected by the glycerol content. Vibration and shock absorption ability was investigated by measuring both loss
tan δ and storage modulus with dynamic mechanical analyzer (DMA). 相似文献
36.
Sang Tae Shin Sung Keun Jang Hong Suk Yang Ok Keun Lee Yhong Hee Shim Won Il Choi Doo Soo Lee Gwan Sun Lee Jong Ki Cho Young Won Lee 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(1):103-107
This study was performed to produce transgenic Korean native goat (Capra hircus) by laparoscopic embryo transfer (ET) to overcome the limitations of ET performed by laparotomy. Transgenic embryos were produced by DNA pronuclear microinjection of in vivo zygotes. The recipient goats were synchronized for estrus by using an introvaginal progesterone devices as a controlled internal drug-releasing insert (CIDR) for 13 days and injection of 400 IU PMSG 48 h before removal of the insert. Embryos were transferred on day 3 and 4 after removal of the insert. Recipient goats were deprived of feed for 48 h, then suspended in a laparotomy cradle at an angle of 45°. After obtaining a sufficient pneumoperitoneum, the laparoscope and forceps were inserted abdominally through 5 mm trocar sleeves. Examination of the ovaries and uterus was performed and then 213 embryos were transferred into the oviducts via the infundibula of 76 recipient goats. To compare pregnancy rates, ET was also performed by laparotomy in 82 recipient goats. The pregnancies in the recipient goats were diagnosed by ultrasound on day 30 after embryo transfer. The pregnancy rate with laparoscopic ET was significantly higher than with ET performed by laparotomy (46.1% vs. 28.6%, p < 0.05). In addition, the pregnancy rates were compared between ovulated and non-ovulated ovaries of the recipient goats in the laparoscopic ET group. No significant difference was observed between the pregnancy rates of ovulated and non-ovulated ovaries (41.3% vs. 33.3%, p < 0.05) suggesting that ET may also be possible in non-ovulated recipients through artificial rupture of Graafian follicles. These results suggest that laparoscopic ET is a highly efficient method for the transfer of goat embryos. 相似文献
37.
Jeong Hyo Lee Jeong‐Woong Park Eun Sol Seo Hoy‐Ung Kim Seo Woo Kim Ji Seon Han Hyun Sik Jun Sung‐Jo Kim Tae Sub Park Byung‐Chul Park 《Animal Science Journal》2019,90(7):903-912
The value‐added products in livestock industry is one of the key issues in order to maximize the revenue and to create a new business model. Numerous studies have suggested application of herbal plants as feed additives to increase health, productivity, and/or high‐quality product in livestock. In this study, the first experiment was designed to develop in vitro evaluation system by using primary chicken myoblast (pCM) cells isolated from pectoralis major of 10‐day‐old male embryos. Subsequently, to evaluate effects of Korean Danggui Angelica gigas Nakai (AGN), we optimized the concentration of AGN root extract for treatment of primary pCM cells. After the treatment of AGN root extract, we compared proliferation and differentiation capacity, and also examined the gene expression. In the second experiment, the next generation sequencing analysis was performed to compare the different patterns of the global gene expression in pCM cells treated with AGN extract. Three up‐regulated (pancreas beta cells, fatty acid metabolism and glycolysis) and one down‐regulated (adipogenesis) gene sets were characterized suggesting that the AGN extract affected the metabolic pathways for the utilization of fat and glucose in chicken muscle cells. Furthermore, we validated the expression patterns of the up‐regulated genes (GCLC, PTPN6, ISL1, SLC25A13, TGFBI, and YWHAH) in the AGN‐treated pCM cells by quantitative RT‐PCR. These results demonstrated that the treatment of AGN extract decreased proliferation and differentiation of pCM cells, and affected the metabolic pathways of glucose and fatty acids. Moreover, AGN extract derived from byproducts such as stem and leaf also showed the reduced proliferation patterns on AGN‐treated pCM cells. Taken together, pCM cell‐based in vitro assay system could be primarily and efficiently applied for evaluating the biofunctional efficacy of various feed additive candidates. 相似文献
38.
39.
Joohyeong Lee Yongjin Lee Geun‐Shik Lee Seung Tae Lee Eunsong Lee 《Reproduction in domestic animals》2019,54(9):1258-1264
Spermatogonial stem cells (SSC) are promising resources for genetic preservation and restoration of male germ cells in humans and animals. However, no studies have used SSC as donor nuclei in pig somatic cell nuclear transfer (SCNT). This study investigated the potential for use of porcine SSC as a nuclei donor for SCNT and developmental competence of SSC‐derived cloned embryos. In addition, demecolcine was investigated to determine whether it could prevent rupture of SSC during SCNT. When the potential of SSC to support embryonic development after SCNT was compared with that of foetal fibroblasts (FF), SSC‐derived SCNT embryos showed a higher (p < .05) developmental competence to the blastocyst stage (47.8%) than FF‐derived embryos (25.6%). However, when SSC were used as donor nuclei in the SCNT process, cell fusion rates were lower (p < .05) than when FF were used (61.9% vs. 75.8%). Treatment of SSC with demecolcine significantly (p < .05) decreased rupture of SSC during the SCNT procedure (7.5% vs. 18.8%) and increased fusion of cell‐oocyte couplets compared with no treatment (74.6% vs. 61.6%). In addition, SSC‐derived SCNT embryos showed higher blastocyst formation (48.4%) than FF‐derived embryos without (28.4%) and with demecolcine treatment (17.4%), even after demecolcine treatment. Our results demonstrate that porcine SSC are a desirable donor cell type for production of SCNT pig embryos and that demecolcine increases production efficiency of cloned embryos by inhibiting rupture of nuclei donor SSC during SCNT. 相似文献
40.
Pharmacokinetic profiles of metamizole (dipyrone) active metabolites in goats and its residues in milk 下载免费PDF全文
Tae Won Kim Andrejs Sitovs Amnart Poapolathep Helen Owen Andrzej Lisowski Zulkyya Abilova Mario Giorgi 《Journal of veterinary pharmacology and therapeutics》2018,41(5):699-705
Metamizole (dipyrone, MET) is a nonopioid analgesic drug commonly used in human and veterinary medicine. The aim of this study was to assess two major active metabolites of MET, 4‐methylaminoantipyrin (MAA) and 4‐aminoantipyrin (AA), in goat plasma after intravenous (IV) and intramuscular (IM) administration. In addition, metabolite concentration in milk was monitored after IM injection. Six healthy female goats received MET at a dose of 25 mg/kg by IV and IM routes in a crossover design study. The blood and milk samples were analyzed using HPLC coupled with ultraviolet detector and the plasma vs concentration curves analyzed by a noncompartmental model. In the goat, the MET rapidly converted into MAA and the mean maximum concentration was 183.97 μg/ml (at 0.08 hr) and 51.94 μg/ml (at 0.70 hr) after IV and IM administration, respectively. The area under the curve and mean residual time values were higher in the IM than the IV administered goats. The average concentration of AA was lower than MAA in both groups. Over 1 μg/ml of MAA was found in the milk (at 48 hr) after MET IM administration. In conclusion, IM is considered to be a better administration route in terms of its complete absorption with long persistence in the plasma. However, this therapeutic option should be considered in light of the likelihood of there being milk residue. 相似文献