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81.
Michishita M Akiyoshi R Yoshimura H Katsumoto T Ichikawa H Ohkusu-Tsukada K Nakagawa T Sasaki N Takahashi K 《Research in veterinary science》2011,91(2):254-260
There is increasing evidence for the presence of cancer stem cells in several solid tumors, and these cancer stem cells have a potential role in tumor initiation, aggression, and recurrence. The stem cell-like properties of spheres derived from canine mammary tumors remain largely elusive. We attempted to induce sphere formation using four cell lines of canine mammary adenocarcinoma, and characterized the spheres derived from a CHMp line in vitro and in vivo. The CHMp-derived spheres showed predominantly CD44+CD24− population, higher expression of stem cell-related genes, such as CD133, Notch3 and MDR, and higher resistance to doxorubicin compared with the CHMp-derived adherent cells. Xenograft transplantations in nude mice demonstrated that only 1 × 104 sphere cells were sufficient for tumor formation. Use of the sphere assay on these sphere-derived tumors showed that sphere-forming cells were present in the tumors, and were maintained in serial transplantation. We propose that spheres derived from canine mammary adenocarcinoma cell lines possess a potential characteristic of cancer stem cells. Spheres derived from canine mammary tumors could be a powerful tool with which to investigate novel therapeutic drugs and to elucidate the molecular and cellular mechanisms that underlie tumorigenesis. 相似文献
82.
Nomura H Ogiso M Yamashita M Takaku H Kimura A Chikasou M Nakamura Y Fujii S Watai M Yamada H 《Journal of agricultural and food chemistry》2011,59(9):5150-5158
Uptake and elimination of aflatoxins (AFs) by rainbow trout ( Oncorhynchus mykiss ) during a long-term (21 days) dietary exposure were studied to assess contamination by AFs in aquaculture fish fed AF-containing feed. The uptake factor (UF) of aflatoxin B(1) (AFB(1)) in muscle ranged from 0.40 × 10(-3) to 1.30 × 10(-3). AFB(1) concentrations in liver were 165-342 times higher than in muscle. AFs from feed were more highly accumulated in liver than in muscle. Aflatoxicol (AFL) and aflatoxin M(1) (AFM(1)) were detected in muscle and liver and also in the rearing water. AFL concentrations were higher than AFM(1) by 2 orders of magnitude in muscle, and AFL was a major metabolite of AFB(1). The elimination rate constants (α) of AFB(1) and AFL in muscle (1.83 and 2.02 day(-1), respectively) and liver (1.38 and 2.41 day(-1), respectively) were very large. The elimination half-life (t(1/2)) of AFB(1) was 0.38 days (9.12 h) in muscle and 0.50 days (12.00 h) in liver. The elimination half-life of AFL in muscle and liver was 0.34 day (8.16 h) and 0.29 day (6.96 h), respectively. These data show that AFs are eliminated rapidly and are not biomagnified in fish. Thus, AFB(1) concentration in muscle of fish fed AFB(1)-containing feed (ca. 500 μg/kg) decreased to below the detection limit (20 ng/kg) of the most sensitive analytical method at 1.54 days (36.96 h) after the change to uncontaminated feed. 相似文献
83.
Hisashi Sato Akihiko Ito Akinori Ito Takashi Ise Etsushi Kato 《Soil Science and Plant Nutrition》2013,59(1):34-47
Although climate conditions primarily determine the distribution and functioning of vegetation, vegetation also influences climate via biophysical and biogeochemical features such as evapotranspiration, albedo, carbon cycling, trace gas emissions and the roughness of the land surface. Forecasts of rapid climate change during the next 100~200 years, fueled by an increase in greenhouse gases, have motivated the development of land surface models (LSMs) that predict changes in vegetation functions. Here, we review how these models have been developed and used to simulate interactive processes between climate and the land surface. Current limitations and future perspectives of the LSMs are also presented. 相似文献
84.
Hisashi Kukimura 《Potato Research》1972,15(2):106-116
Summary Gamma-rays from a60Co source were applied to dry, ‘true’ seed from the cross ofSpartaan × Maris Piper and the segregation rations for various characters were investigated. The treatment affected the segregation ratios for stem
colour, tuber shape, net skin, and vein necrosis; also possibly affected were maturity and number of primary leaflets. Ratios
for depth of eye, leaf index and secondary growth of tubers were not changed. The changes in segregation ratios may be due
to mutations and/or chromosome aberrations. Most of the changes in segregation ratios are suggested to be due to an increase
in the frequency of nulliplex genotypes. The mutation rates estimated from the segregation ratios ranged from 2.0×10−6 to 10.9×10−6 per R.
Einfluss der Gammabestrahlung auf die Aufspaltungsverh?ltnisse in Zuchfamilien bei der Kartoffel
Zusammenfassung Trockene Samenk?rner aus der KreuzungSpartaan Maris Piper wurden mit Gammastrahlen60Co in Dosen von 2, 4, 8, 16, 32 und 64 krad behandelt und die Aufspaltungsverh?ltnisse für verschicdene Merkmale untersucht. Die Keimungs- und Reproduktionsraten für die verschiedenen Dosen sind in Abb. I dargestellt. Als Reproduktionsrate wird das Verh?ltnis der Anzahl knollentragender Pflanzen zur Gesamtanzahl überlebender Pflanzen bezeichnet. RD50 der Reproduktionsrate war ungef?hr 40 krad. Die H?ufigkeit mangelhafter Pflanzen wurde durch die Bestrahlung erh?ht (Tabelle 1). Die Behandlung beeinflusste die Aufspaltungsverh?ltnisse in der Stengelfarbe (Tabelle 2), Knollenform (Tabelle 3), Netzzeichnung der Schale (Tabelle 5) und Adernnekrose (Tabelle 8). M?glicherweise wurden auch die Reife (Tabelle 9) und die Zahl der prim?ren Fiederbl?ttchen (Tabelle 6) ver?ndert. Die Verh?ltnisse für die Augentiefe (Tabelle 5), Fiederbl?ttchenform (Tabelle 7) und die Kindelbildung der Knollen (Tabelle 5) wurden nicht ver?ndert. Die H?ufigkeit ph?notypischer rezessiver Erscheinungen wurde durch die Behandlung bei einigen Merkmalen. wie z.B. Netzeeichnung der Schale (Tabelle 5). Anzahl Fiederbl?ttchen (Tabelle 6) und Schalenfarbe (Tabelle 4), significant verringert. Die Aenderung in den Aufspaltungsverh?ltnissen dürfte auf Mutationen und/oder Chromosomen-Abweichungen zurückzuführen sein. Man vermutet, dass die meisten Aenderungen in den Aufspaltungsverh?ltnissen auf ein Ansteigen der H?ufigkeit von nulliplexen Genotypen zurückgehen. Die Sch?tzung der Mutationsraten auf Grund der Aufspaltungsverh?ltnisse bewegt sich zwischen 2.0 · 10−6 und 10.9 · 10−6 pro R (Tabelle 10).
Effects de rayons gamma sur les rapports de ségrégation dans des familles de ponne de terre
Résumé On a appliqué des rayons gamma émis par le cobalt 60 à des doses de 2, 4, 8, 16, 32 et 64 krad à des semences sèches provenant du croisementSpartaan. Maris Piper et on a recherché les rapports de ségrégation de différents caractères. La Figure I donne les taux de germination et de reproduction pour les différentes doses. Le taux de reproduction est défini par le rapport de nombre de plantes qui tubérisent au nombre total de plantes survivant. RD50 du taux de reproduction est d'environ 40 krad. L'irradiation accroit la fréquence de plantes déficientes (Tableau 1). Le traitement influence les rapports de ségrégation pour la couleur de la tige (Tableau 2) la forme du tubercule (Tableau 3). la peau réticulée (Tableau 5) et la nécrose des nervures (Tableau 8). II est possible que soient également influencées la maturité (Tableau 9), ainsi que le nombre de folioles primaires (Tableau 6). Ne sont pas modifiés les rapports pour la profondeur des yeux (Tableau 5) la forme des folioles (Tableau 7) et la croissance secondaire des tubercules (Tableau 5). La fréquence de phénotypes récessifs est significativement abaissée par le traitement pour quelques caractères tels que peau réticulée (Tableau 5). nombre de folioles latérales (Tableau 6) la couleur de la peau (Tableau 4). Les changements dans les rapports de ségrégation peuvent être dus à des mutations ou à des aberrations chromosomiques. On pense que la plupart des changements dans les rapports de ségrégation sont dus à une augmentation de la fréquence de génotypes nulliplex. Les taux de mutations estimés à partir des rapports de ségrégation varient de 2.0 · 10−6 à 10.9 · 10−6 par R (Tableau 10).相似文献
85.
Identification of RFLP markers linked with heading date and its heterosis in hexaploid wheat 总被引:3,自引:0,他引:3
Recombinant inbred lines (RILs) from a cross between hexaploid wheat (T. aestivum cv. Chinese Spring (CS) and T. spelta (Sp)) were used for RFLP analysis of heading date and heterosis. Fourteen RFLP markers linking with heading date were identified;
two were localized on chromosome 1A, one on 2A, three on 2B, one on 2D, four on 5A, two on 7A and one unlinked but reported
to be on group 2. All of these markers may be attributable to genes for earliness per se. However, the markers in the chromosomes of 1A and 7A are new to this study. RILs were crossed with (tim)-CS, the alloplasmic CS with T. timopheevi cytoplasm, and the heterosis from earlier-parent and mid-parents were calculated for the F1s to examine the heterotic effect toward earliness on heading date. Five and two RFLP markers were associated with heterosis
from the earlier-parent and mid-parents, respectively. They were distributed on the chromosomes of homoeologous groups 1 and
2.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
86.
The rates of hypocotyl and radicle survival and of germination success were investigated in mature acorns ofQuercus variabilis Blume in relation to endosperm loss due to seed insects. The acorns were damaged by curculio weevils (Coleoptera: Curculionidae)
and moths, including tortricid moths (Lepidoptera: Tortricidae); the former were more abundant than the latter. Acorns damaged
by curculio weevils showed a significantly lower germination rate when there was a large endosperm loss than the rate for
sound acorns. The survival rate of the hypocotyl and radicle also decreased as endosperm loss increased. These results suggest
that acorn germination is directly inhibited by damage to the hypocotyl and radicle, which depends on the amount of endosperm
eaten by the weevils. However, the germination rate of acorns with hypocotyl and radicle was consistently high, irrespective
of the degree of endosperm loss, which suggests that weevil-damaged acorns probably germinate, provided the hypocotyl and
radicle survive until the cessation of damage.
Research Fellow of the Japan Society for the Promotion of Science.
This study was supported in part by Grants-in-Aid for Scientific Research from the Japan Ministry of Education, Science and
Culture (No. 09001647, No. 10660144, and No. 11460068) and the Nippon Life Insurance Foundation. 相似文献
87.
Yoshitaka Sakakura Shigeaki Shiotani Hisashi Chuda Atsushi Hagiwara 《Fisheries Science》2006,72(5):939-947
The water flow in larval rearing tanks has been indicated to cause mass mortality of the seven-band grouper Epinephelus septemfasciatus larvae. Therefore, a new aerating method was tested in an actual scale intensive rearing tank (8.0 m in diameter, 1.87 m
of water depth, 100 m3 of volume), in which an aerator was positioned at the center of the rearing tank surrounding cylindrical drain (1.2 m in
diameter) to generate the flow field, and seven larval rearing trials were performed. The survival rate with the former aeration
methods were compared, in which several aerators were located in the rearing tank. The survival rate at 10 days after hatching
with the new aeration method (61.5±5.1%, n=7) was approximately three times higher than the former methods (21.2±13.7%, n=6). The flow environment of rearing tanks was also examined by quantifying the flow field, and the relationship between the
flow field in the rearing tank, behavior of larvae and survival discussed. It was confirmed that the vertical circulating
flow was observed in rearing tanks, and determined effectively the survival and the behavior of grouper larvae in patchiness. 相似文献
88.
Masato MIYAKE Shinichiro HAYASHI Yoshikazu TAKETA Shunsuke IWASAKI Kouichi WATANABE Shyuich OHWADA Hisashi ASO Takahiro YAMAGUCHI 《Animal Science Journal》2010,81(2):223-229
Myostatin (MSTN) is a negative regulator during muscle differentiation, whereas insulin‐like growth factors (IGFs) are essential for muscle development. MSTN and IGFs act oppositely during myogenesis, but there is little information on the mutual relationship of MSTN and IGFs. The present study was conducted to examine whether MSTN affects IGF expression during early myogenesis in cattle. IGF‐1 mRNA was similarly expressed in M. longissimus thoracis of double‐muscled (DM) and normal (NM) Japanese shorthorn cattle. IGF‐2 mRNA expression was consistently higher in the normal and regenerating muscle of DM cattle than those of NM cattle. When myoblasts were isolated from regenerating M. longissimus thoracis, IGF‐2 mRNA expression showed a significant increase in differentiating DM derived myoblasts (DM‐myoblasts) as compared with differentiating NM derived myoblasts (NM‐myoblasts). An addition of recombinant mouse myostatin (rMSTN) to myoblast cultures attenuated IGF‐2 mRNA expression and decreased myotube formation, but did not effect IGF‐1 mRNA expression. An activin‐like kinase (ALK) inhibitor, SB431542, mediates MSTN action, suppressed the translocation of Smad2/3 into the nucleus in DM‐myoblasts, and restored the attenuated IGF‐2 mRNA expression and the decreased myotube formation induced by rMSTN in myoblast cultures. The findings indicate that MSTN may negatively regulate myoblast differentiation by suppressing IGF‐2 expression via ALK‐Smad signaling. 相似文献
89.
Vonika NOU Kyouko TOMOSHI Hiroaki INOUE Hideto KUWAYAMA Hisashi HIDARI 《Animal Science Journal》2003,74(2):129-136
To investigate the effects of high and low somatostatinergic tone on GH-releasing peptide-2 (GHRP-2) and GH-releasing hormone (GHRH)-induced growth hormone (GH) secretion in swine, we examined GHRP-2- and GHRH-induced GH secretion after pretreatment with atropine or pyridostigmine. Pretreatment of swine with atropine (80 µg/kg bodyweight (BW), intravenous (i.v.)) 15 min before i.v. administration of saline, GHRP-2 (30 µg/kg BW), GHRH (1 µg/kg BW) or a combination of GHRP-2 and GHRH, reduced plasma GH area under the curve ( P < 0.05), completely blocked GH response to GHRH, and attenuated GH response to GHRP-2 and GHRH combined ( P < 0.05), without affecting GH response to GHRP-2 only. A synergistic effect of GHRP-2 and GHRH was not observed. In contrast, pretreatment of swine with pyridostigmine (100 µg/kg BW, i.v.), under the same pretreatment conditions as above, increased plasma GH concentration ( P < 0.01), augmented GH response to GHRP-2 ( P < 0.05), and GHRP-2 and GHRH combined ( P < 0.05), but did not affect GH response to GHRH. These results suggest that the cholinergic muscarinic agents atropine and pyridostigmine modulate the GH response to GHRP-2 and GHRH, and that GHRP-2 acts antagonistically on the inhibitory effect of somatostatin in swine. 相似文献
90.
Masami Mochizuki Hisashi Furukawa 《Comparative immunology, microbiology and infectious diseases》1989,12(4):139-146
From the reasons that canine coronavirus (CCV) grows more efficiently than feline coronavirus in a cell culture and they are mutually related in their antigenicities, an enzyme-linked immunosorbent assay (ELISA) using CCV-infected feline kidney (CRFK) cells as substrate antigens was developed for detection of anti-coronavirus antibodies in cats. It was indispensable for generating coronavirus-specific ELISA antibody activities that the sample was applied to the mock-infected, normal CRFK cells in parallel with the CCV-infected cells and then the optical density values given by the mock-infected cell antigen were subtracted from those given by the virus-infected cell antigen. On the basis of ELISA antibody titers obtained in sera from the cats experimentally infected with CCV and from the spontaneous feline infectious peritonitis (FIP) cases, the ELISA described in the present study was found to be applicable as a simple and easy serologic test which was able to detect anti-coronavirus antibodies as efficiently as the indirect immunofluorescence assay with homologous FIP virus. 相似文献