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21.
T Y Hsu H W Renshaw C W Livingston J L Augustine D L Zink B B Gauer 《American journal of veterinary research》1985,46(5):1206-1211
Inoculation of live Corynebacterium pseudotuberculosis, culture supernatant, ammonium sulfate-fractionated crude exotoxin, or chromatographically purified exotoxin preparations into gnotobiotic small ruminants (n = 13) caused death of the ruminants within 48 hours. Characteristic changes observed in animals living greater than or equal to 2 hours after inoculation included hemorrhage and edema at the site of injection, severe hemolytic anemia and hemoglobinuria, dark red fluid in body cavities, lung edema, and icterus. The crude exotoxin preparation caused a syndrome of acute shock in 2 lambs that died within 15 minutes after inoculation. Clinical and pathologic responses of animals inoculated with culture supernatant and purified toxin were similar. Histopathologic evidence indicated that the exotoxin caused necrotic changes in the proximal convoluted tubules of the kidneys. Inoculation with live organisms caused multiple foci of suppurative inflammation in skeletal muscle and adjacent adipose tissue, whereas such changes were not observed in animals administered exotoxin preparations. Although C pseudotuberculosis exotoxin induced a hemolytic anemia in the experimental animals, it did not lead to in vitro lysis of ovine, caprine, or bovine erythrocytes, unless they had been sensitized with Rhodococcus (Corynebacterium) equi filtrate. The toxic sphingomyelin-specific phospholipase D from C pseudotuberculosis had a molecular weight of 31,000 daltons and an isoelectric point of approximately 9.6. The elution profile of exotoxin on a carboxymethyl Sephadex column was studied and the majority of the enzymatic activity was eluted by a NaCl gradient (0.25M to 0.7M) with a maximum at 0.35M NaCl.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
22.
Experimental infection of normal and immunosuppressed pigs with Pseudomonas pseudomallei 总被引:1,自引:0,他引:1
AD THOMAS JC FORBES-FAULKNER TL D''ARCY JH NORTON D HOFFMANN 《Australian veterinary journal》1990,67(2):43-46
A single dose of 5 x 10(8) bacilli of Pseudomonas pseudomallei by intratracheal injection resulted in acute (21 cases) or chronic (19 cases) melioidosis in 40 of 48 pigs. Fifteen (10 acute and 5 chronic) had been immunosuppressed by cyclophosphamide before inoculation. The major clinical signs were initial fever, marked neutrophilia and, in the acute cases, respiratory distress. There were no signs of the nasal and ocular discharge, paresis or diarrhoea seen in acute cases in south-east Asia. The cyclophosphamide treatment caused a significant decrease in the neutrophil count by 7 d after inoculation in all 15 immunosuppressed pigs, and all were culture positive at necropsy. Eight of the 33 non-treated pigs were culture negative at necropsy. Pigs overcoming the initial phase of infection had more abscess-like nodules that were bacteriologically sterile at necropsy than the pigs with acute cases of melioidosis. P. pseudomallei was isolated predominantly from the spleen, lungs and the injection site. Although only one strain was used in this study, it is likely that Australian strains of P. pseudomallei are not as virulent as the south-east Asian isolates. 相似文献
23.
Effects of yohimbine on xylazine-pentobarbital anesthesia were evaluated in ponies. Five minutes after the IV injection of xylazine (1.1 mg/kg of body weight), pentobarbital sodium (12.7 mg/kg, IV) and additional xylazine (2.2 mg/kg, IM) were given and produced anesthesia in 12 ponies for 64.0 +/- 16.4 minutes (mean +/- SD) as well as immobilization for 89.8 +/- 34.2 minutes. Eleven ponies were given yohimbine (0.1 mg/kg, IV) 50 minutes after pentobarbital dosing. In these 11 ponies, durations of anesthesia and immobilization were shorter, 52.0 +/- 1.4 and 65.5 +/- 14.8 minutes, respectively. The xylazine-pentobarbital combination caused bradycardia that was reversed by yohimbine injection. Xylazine-pentobarbital produced a small, but steady, decrease of mean arterial blood pressure, which was compounded by yohimbine administration and was evident for approximately 2 minutes. Within a minute after yohimbine injection, the ponies' respiratory rate decreased and the length of inspiration and expiration and thoracic breathing increased. This lasted approximately 2 to 3 minutes and was followed by an increase in respiratory rate. The anesthesia also produced a decrease in PaO2 that gradually returned to base line in 12 control ponies, but was more pronounced in 11 ponies given yohimbine. The PaCO2, although remaining moderately high in control ponies, returned to base line after yohimbine injection. An increased pHa was seen 60 minutes after induction of anesthesia and was especially noticeable after yohimbine administration. Decreases in the number of WBC, hemoglobin content, PCV, plasma protein and serum aspartate transaminase resulting from xylazine-pentobarbital were reversed by yohimbine. Conversely, serum glucose values and creatine kinase activities were increased by xylazine-pentobarbital.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
24.
H Han Hsu 《Veterinary parasitology》1986,21(4):247-254
Metacercariae of Fasciola hepatica were labeled with 75Se by exposure of infected Lymnaea columella to 75Se-M, 20 muCi/snail, in 5 ml of water. Seventy-two mice were inoculated with 50 75Se-labeled metacercariae. At intervals after infection, the distribution of metacercariae in gut, body cavities and liver was studied by compressed organ autoradiography, and a variant of this technique adapted to gut content and body cavity washes. Ag degree focus counts from autoradiograms expressed as percentage of actual exposure level were subjected to probit analysis. Estimates of the average departure time of radio-labeled maritas from gastrointestinal tracts and average arrival time into the abdominal cavities were 12.2 and 12.5 h, respectively. The peak accumulation of maritas in abdominal cavities occurred at 24 h post-inoculation. A 7.7-h discrepancy between estimated average departure time from abdominal cavities (92 h) and average arrival time at livers (99.7 h) was attributed to experimental error. 相似文献
25.
On mechanical behavior of traditional timber shear wall in Taiwan I: background and theory derivation 总被引:1,自引:0,他引:1
The objectives of this study were to explore the mechanical behavior of traditional timber shear walls in Taiwan and to propose
a theoretical model to predict their lateral force resistance. An extensive field investigation was conducted, and the dimensions,
tectonic detail, and materials used were recorded. The data collected were used as the reference for theoretical derivation
and experimental design. In the theoretical model, the moment resistance of entire shear walls was derived from the contributions
of the moment-resisting capacity supplied not only by embedment and friction action between board units and beams but also
the dowel action of bamboo nails. Timber shear walls with various geometric conditions and material properties are considered.
The theoretical model demonstrated in this study can be used to predict the mechanical behavior of timber shear walls and
will be verified by experiments in our next article. 相似文献
26.
Summary The deformation and stresses in a circular wood log resulting from an arbitrary radial moisture distribution are examined. In this paper the log is modeled as a layered cylinder, with each layer assumed to be linearly elastic, cylindrically orthotropic, and homogeneous. The general solution to the equations of elasticity for a representative layer is given; constants of integration in the solution are determined through application of appropriate continuity conditions at the layer interfaces. Numerical examples are presented for logs of Scots pine which illustrate the effect of nonuniform moisture content upon the displacement and stress distributions. 相似文献
27.
Lactuca indica L. (Compositae family) is used as a folk medicine in anti-inflammatory, antibacterial, antidiabetic, and other medications in Asia. The objectives of this study were to evaluate the antiproliferative effect of ethanol extracts of Lactuca indica L. (EEL) on human leukemic HL-60 cell lines and its active components. The results showed that EEL exhibited strong cytotoxic effects against HL-60 cells; the IC50 value was 313 microg/mL. Flow cytometric analysis of the externalization of phosphatidylserine (PS) using the annexin V/PI method on EEL-treated HL-60 cells showed a concentration-dependent increase of apoptosis. Moreover, EEL could induce typical DNA fragmentation in a concentration- and time-dependent manner as determined by electrophoresis and TUNEL assays. The treatment of HL-60 cells with EEL induced significant accumulation of cells in the G0/G1 phase, indicating that EEL is a cell-cycle-dependent anticancer agent. Our results also indicate that EEL-induced apoptosis in HL-60 cells is associated with the loss of mitochondrial membrane potential (delta psi m). EEL contains 5% phenolic compounds, such as quercetin, caffeic acid, rutin, and chlorogenic acid. Among the four active phenolic compounds, quercetin was found to be the most effective in inhibition against cell viability and in alteration of mitochondrial function. Our results suggest that the induction of apoptosis by EEL might offer a pivotal mechanism for its chemopreventive action. 相似文献
28.
Gallic acid induces apoptosis in 3T3-L1 pre-adipocytes via a Fas- and mitochondrial-mediated pathway
Gallic acid (3,4,5-trihydroxybenzoic acid) is a naturally abundant plant phenolic compound. Our previous studies have shown that some phenolic acids such as gallic acid inhibit cell growth and induce apoptosis in 3T3-L1 pre-adipocytes. However, the molecular mechanism of gallic acid in the induction of cell apoptosis is still unclear. In this study, we investigated the effect of gallic acid on the apoptotic pathway in 3T3-L1 pre-adipocytes. Western blot data revealed that gallic acid stimulated an increase in the protein expression of Fas, FasL, and p53. The ratio of expression levels of pro- and anti-apoptotic Bcl-2 family members was changed by gallic acid treatment. Gallic acid released mitochondrial cytochrome c into the cytosol and subsequently induced the activation of caspase-9 and caspase-3, which were followed by the cleavage of poly(ADP-ribose) polymerase. Pretreatment with a general caspase-9 inhibitor (Z-LEHD-FMK) and caspase-3 inhibitor (Z-DEVD-FMK) prevented gallic acid from inhibiting cell viability in 3T3-L1 pre-adipocytes. The data also indicated that treatment with gallic acid inhibited histone deacetylase activity in 3T3-L1 pre-adipocytes. These results demonstrate that gallic acid induces apoptosis in 3T3-L1 pre-adipocytes through the Fas and mitochondrial pathway. The induction of cell apoptosis by gallic acid may prove to be a pivotal mechanism for decreased pre-adipocyte proliferation. 相似文献
29.
Effects of flavonoids and phenolic acids on the inhibition of adipogenesis in 3T3-L1 adipocytes 总被引:4,自引:0,他引:4
Obesity has become a global epidemic in both developed and developing countries, and it is a significant risk factor for various diseases such as diabetes, cancer, heart disease, and hypertension. In the present study, the effect of naturally occurring antioxidants (flavonoids and phenolic acids) on the inhibition of adipogenesis in 3T3-L1 adipocytes was investigated. The results showed that o-coumaric acid and rutin had the highest inhibition on intracellular triglyceride (61.3 and 83.0%, respectively) among 15 phenolic acids and 6 flavonoids tested. However, the oil red o stained material (OROSM) showed that cell number in 3T3-L1 adipocytes was not influenced by those compounds. For glycerol-3-phosphate dehydrogenase (GPDH) activity, the data indicated that o-coumaric acid and rutin had the highest inhibition on GPDH activity (54.2 and 66.8%, respectively) among the compounds tested. o-Coumaric acid and rutin also inhibited the expression of PPARgamma, C/EBPalpha and leptin and then up-regulated expression of adiponectin at the protein level. Some naturally occurring antioxidants efficiently suppressed adipogenesis in 3T3-L1 adipocytes. These results suggest that o-coumaric acid and rutin targeted for adipocyte functions could be effective in improving the symptoms of metabolic syndrome. 相似文献
30.
W.‐L. Hsu Y.‐S. Lin Y.‐Y. Hu M.‐L. Wong F.‐Y. Lin Y.‐J. Lee 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(2):437-442