全文获取类型
收费全文 | 860篇 |
免费 | 40篇 |
国内免费 | 1篇 |
专业分类
林业 | 87篇 |
农学 | 26篇 |
129篇 | |
综合类 | 23篇 |
农作物 | 39篇 |
水产渔业 | 138篇 |
畜牧兽医 | 384篇 |
园艺 | 7篇 |
植物保护 | 68篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 21篇 |
2021年 | 42篇 |
2020年 | 25篇 |
2019年 | 12篇 |
2018年 | 21篇 |
2017年 | 20篇 |
2016年 | 39篇 |
2015年 | 32篇 |
2014年 | 52篇 |
2013年 | 69篇 |
2012年 | 51篇 |
2011年 | 56篇 |
2010年 | 30篇 |
2009年 | 35篇 |
2008年 | 62篇 |
2007年 | 63篇 |
2006年 | 65篇 |
2005年 | 53篇 |
2004年 | 44篇 |
2003年 | 23篇 |
2002年 | 37篇 |
2001年 | 18篇 |
2000年 | 12篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1995年 | 3篇 |
1985年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有901条查询结果,搜索用时 15 毫秒
91.
Evaluation of mosquitoes, Aedes vexans, as biological vectors of porcine reproductive and respiratory syndrome virus 总被引:1,自引:0,他引:1 下载免费PDF全文
Satoshi Otake Scott A. Dee Roger D. Moon Kurt D. Rossow Carlos Trincado Carlos Pijoan 《Canadian journal of veterinary research》2003,67(4):265-270
The objective of this study was to determine whether mosquitoes, Aedes vexans (Meigen), could serve as biological vectors of porcine reproductive and respiratory syndrome virus (PRRSV). Specifically, the study assessed the duration of viability and the site of PRRSV within mosquitoes, and evaluated whether PRRSV could be transmitted to a susceptible pig by mosquitoes following a 7- to 14-day incubation period after feeding on an infected pig. For the first experiment, a total of 100 mosquitoes were allowed to feed on a pig, experimentally infected with PRRSV (day 7 post-inoculation) and were then maintained alive under laboratory conditions. A set of 10 mosquitoes were collected at 0 hour (h), 6 h, 12 h, 24 h, 48 h, 72 h, 5 days (d), 7 d, 10 d, and 14 d post-feeding (pf). Samples of exterior surface washes, salivary glands, thorax carcasses, and gut homogenates were collected from each set of mosquitoes, and tested for PRRSV. Infectious PRRSV was detected by polymerase chain reaction and swine bioassay only from the gut homogenates of mosquitoes collected at 0 h and 6 h pf. For the second experiment, a total of 30 mosquitoes were allowed to feed on a pig, experimentally infected with PRRSV and the mosquitoes were then maintained under laboratory conditions. On each of day 7, 10, and 14 pf, a set of 10 mosquitoes were allowed to feed on a susceptible pig. Transmission of PRRSV to susceptible pigs did not occur, and PRRSV was not detected from the mosquitoes. These findings indicate that mosquitoes are not likely to serve as biological vectors of PRRSV. 相似文献
92.
Abhinandan?Deora Yasuyuki?HashidokoEmail author Md.?Tofazzal?Islam Satoshi?Tahara 《European journal of plant pathology / European Foundation for Plant Pathology》2005,112(4):311-322
A total of 150 bacteria were isolated from rhizoplanes of the host and non-host plants of a phytopathogenic Peronosporomycete Aphanomyces cochlioides. Upon screening, 5% of the isolates were evaluated as antagonists as they inhibited radial growth of A. cochlioides AC-5 hyphae in a dual culture assay. In addition, those antagonistic bacteria also induced characteristic morphological alterations in the A. cochlioides AC-5 hyphae that grew towards bacterial colonies. Hyphal morphological alterations observed in AC-5 and other tested strains of Peronosporomycetes included excessive branching, curly growth, unusually longer and pointed tip formation and swelling; all of these were comparable to the alterations induced by known antimicrobial compounds. Among the antagonistic bacteria, Pseudomonas sp. strain EC-S101 induced a unique branching pattern (tree-like) in AC-5 hyphae by continuous apical bifurcation of successive hyphae, where increases in number of branches and hyphal area were linearly correlated with time up to 10 h. Our observations suggested that the pathogen might have lost its ability of normal branch production; however maintained the capability of self-branching. Soluble extracts from the culture fluids of Pseudomonas sp. strain EC-S101 and Stenotrophomonas maltophilia EC-S105 induced similar excessive branching and curly growth in A. cochlioides hyphae as the respective bacterium. These results revealed that bacterial metabolites appeared to be responsible for induction of morphological alterations. Interestingly, the antagonistic bacteria that induced hyphal morphological alterations, also efficiently suppressed in vivo damping-off disease caused by AC-5. We suggest that antagonistic rhizoplane bacteria have the capability to induce diverse morphological alterations in Peronosporomycetes hyphae during in vitro interactions. Hyphal morphological alterations associated with growth inhibition and the induction of characteristic morphological changes indicate antagonistic activity against the Peronosporomycete. 相似文献
93.
Distribution of Cucumber mosaic virus (CMV) in shoot meristem tissue of CMV-inoculated tobacco was successively analyzed with immunohistochemical microscopy and in situ hybridization. CMV signals were detected in the tissue at 7 days postinoculation (dpi), but then they decreased and disappeared after 14dpi. Detailed observation confirmed CMV invasion of shoot apical meristem at 6–8dpi. Short interfering RNA corresponding to CMV RNAs was first detected at 7dpi and was detected up to 24dpi. These results suggest that the shoot meristem tissue is infected with CMV but subsequently recovers from the infection by RNA silencing. 相似文献
94.
Hosaka S Hosaka M 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(5):593-597
A 10-year-old spayed mongrel dog was referred with repeated intercurrent hematochezia and anal bleeding. The dog was vigorous and had a normal appetite, and the fecal test showed no abnormal signs. Despite treatment primarily with sulfasalazine, the condition did not improve and unilateral blindness developed. A Prototheca zopfii infection was identified by further examination with bowel culture on Sabouraud's agar without cyclohexane and antibiotics. Subsequent to a vision loss in the other eye, the dog died showing signs of neurological disorder. 相似文献
95.
Glucose uptake activity in murine red blood cells infected with Babesia microti and Babesia rodhaini
Ohmori T Adachi K Fukuda Y Tamahara S Matsuki N Ono K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(8):945-949
The glucose uptake activity in Babesia rodhaini and B. microti - infected red blood cell (IRBC) was investigated in mice using 2-deoxy-D-glucose (2DOG) and L-glucose (L-Glc), a non-metabolizable analogue of D-glucose and non-incorporative glucose to non-infected RBC (NRBC), respectively. The uptake activities of both DOG and L-Glc were higher in IRBCs than those in NRBC. The concentration dependent uptake of 2DOG and L-Glc in both IRBC revealed a linear curve, indicating non-transporter mediated uptake. In addition, B. microti IRBC showed higher 2DOG uptake than B. rodhaini IRBC, whereas no difference was observed in L-Glc uptake. These results indicated that some new glucose uptake system, at least two systems, developed in both IRBC. The new systems were sodium independent, non-competitive to L-Glc, and sensitive to temperature. One of two systems had no kinetical difference between B. rodhaini and B. microti IRBC, however another one might have higher uptake activity in B. microti IRBC compared to that in B. rodhaini IRBC. 相似文献
96.
Kim H Tanaka S Une S Nakaichi M Sumida S Taura Y 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2004,66(12):1543-1547
Hydroxyethyl starch (HES) is a nonpenetrating extracellular cryoprotectant. In contrast to glycerol, it does not require labor-intensive removal from thawed red blood cells (RBCs) prior to transfusion. In this study, we compared glycerol and HES, and assessed HES as a substitute for glycerol in cryopreserved canine RBCs. The RBCs were preserved for 2 months in liquid nitrogen using a 20% (w/v) glycerol solution, and variable concentrations of HES solution. We evaluated the two cryoprotectants by the percentage of post-thaw hemolysis from the total free hemoglobin, saline stability, osmotic fragility, and by observing the erythrocyte morphology using a scanning electron microscope after thawing. The optimal concentration of HES was 12.5% (w/v) for the cryopreservation of canine RBCs. The thaw hemolysis, saline stability, and osmotic fragility index were 25.6 +/- 4.7%, 87.8 +/- 6.9%, and 0.445 +/- 0.024% NaCl respectively. These parameters resemble the results of RBCs frozen in a 20% (w/v) glycerol solution, which are 24.7 +/- 5.2%, 99.2 +/- 0.1%, and 0.485 +/- 0.023% NaCl respectively. From a morphological point of view, 12.5% (w/v) HES showed the best cryoprotection of RBCs compared to the other concentrations of HES. These results suggest that HES could be a possible substitute for glycerol for the cryopreservation of canine RBCs. 相似文献
97.
Ishida M Ono K Taguchi S Ohashi S Naito J Horiguchi K Harigaya T 《The Journal of reproduction and development》2004,50(5):515-523
Gene expressions and their interaction are complex and have not been definitely clarified in the placenta. To identify interactions of gene products previously not studied, we applied cDNA subtraction analyses to the placenta between days 12 and 16, days 12 and 14, days 14 and 16 of pregnancy. Among subtracted cDNAs cathepsin M, Q and R in PECs were specifically identified on days 14 and 16 pregnancy. All of these gene expressions exhibited a similar pattern to the mPL-II gene expression determined by northern blot and RT-PCR analyses. By means of in situ hybridization, these mRNAs were localized in the basal and labyrinth zones of the placenta on day 16 of pregnancy. Double staining studies of cathepsin Q or cathepsin R mRNA by in situ hybridization followed by immunohistochemical staining of mPL-II in the same section revealed that signals for cathepsin Q and cathepsin R mRNAs were colocalized in mPL-II immunopositive trophoblast cells in the basal and labyrinth zones of the placenta on day 16 of pregnancy. Possible association of cathepsins with mPL-II may play important roles in placental functions during the latter half of pregnancy in mice. 相似文献
98.
Matsuyama S Ohkura S Ichimaru T Sakurai K Tsukamura H Maeda K Okamura H 《The Journal of reproduction and development》2004,50(6):697-704
The time course of GnRH pulse generator activity and plasma concentrations of energy substrates and insulin were simultaneously observed in female goats during 4-day fasting and subsequent refeeding in the presence or absence of estrogen for a better understanding of the mechanism of energetic control of gonadotropin secretion in ruminants. The GnRH pulse generator activity was electrophysiologically assessed with the intervals of characteristic increases in multiple-unit activity (MUA volleys) in the mediobasal hypothalamus. In estradiol-treated ovariectomized (OVX+E2) goats, the MUA volley intervals increased as fasting progressed. Plasma concentrations of non-esterified fatty acid and ketone body increased, while those of acetic acid and insulin decreased during fasting. The MUA volley intervals and plasma concentrations of those metabolites and insulin were restored to pre-fasting levels after subsequent refeeding. In ovariectomized (OVX) goats, changes in plasma metabolites and insulin concentrations were similar to those in OVX+E2 goats, but the MUA volley intervals were not altered. The present results demonstrated that fasting suppressed GnRH pulse generator activity in an estrogen-dependent manner. Changes in plasma concentrations of energy substrates and insulin during fasting were associated with the GnRH pulse generator activity in the presence of estrogen, but not in the absence of the steroid in female goats. 相似文献
99.
Murakami S Ogawa A Kinoshita T Matsumoto A Ito N Nakane T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(4):387-391
Fourteen diseased pigs from four farms in which there had been an outbreak of salmonellosis were investigated. Granulomatous inflammation with depletion of lymphocytes was observed in the swollen lymph nodes in these pigs. Antigens to porcine circovirus type 2 (PCV2) were immunolabeled in the lesions along with detection of viral DNA as PCV2 by polymerase chain reaction (PCR). In addition, antigens to porcine reproductive respiratory syndrome virus (PRRSV) were immunodetected in the lungs and Salmonella Choleraesuis was isolated from the affected pigs. The nine salmonellosis affected pigs, five (55.6%) with salmonellosis and PMWS concurrently infected with PRRSV were much higher than those infected with salmonellosis and PMWS (22.2%) or with salmonellosis and PPPRV (22.2%). 相似文献
100.
Zakimi S Kyan H Oshiro M Sugimoto C Fujisaki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(4):401-404
To determine the prevalence of the 3 primary clonal lineages of Toxoplasma gondii (strain types I, II, and III) in pigs in Okinawa Prefecture, we analyzed lymph node samples that had been collected at an abattoir by PCR analysis using primers specific for the Toxoplasma gondii SAG2 locus. This study revealed the presence of this parasite in 57 out of 101 samples examined. Restriction fragment length polymorphism (RFLP) in PCR-amplified SAG2 products was used to group strains into one of the three genotypes of T. gondii. Genotypes I and II were equally predominant, accounting for 22 (44.9%) and 23 (46.9%) of 49 SAG2-positive samples, respectively, while the type III strain was found in only 4 (8.2%) of the 49 samples. The other 8 samples were indistinguishable by PCR-RFLP analysis. Polymorphisms for the 3 genotypes were confirmed at the sequence level for several samples using the sequences from the RH strain, the Beverley strain, and the C56 strain as references. On the other hand, the dihydropteroate synthase gene, which is responsible for sulfonamide resistance, was amplified in 40 of 54 SAG2-positive samples by PCR with the specific primers, and further RFLP and sequence analysis revealed that none of them carried the drug-resistant form of the dhps gene. This is the first report of genotyping of T. gondii distributed in Japan. 相似文献