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71.
本试验旨在研究氧化应激对断奶仔猪机体氧化还原状态的影响。选用24头28日龄断奶仔猪,随机分为3个处理组,每组8个重复,每个重复1头猪,采用单因子试验设计。基础日粮为玉米-豆粕型,以饲喂基础日粮为对照组,饲喂氧化鱼油和腹腔介入12mg/kg体重敌草快(Diquat)为应激组,试验期26d。结果表明:(1)与对照组相比,氧化鱼油和Diquat都造成了脾脏损伤,使脾脏和胸腺指数降低(P<0.05);(2)饲喂氧化鱼油显著增加了脾脏MDA(丙二醛)含量(P<0.05),降低血浆抑制羟基自由基的能力(P<0.05),极显著降低脾脏GST(谷光苷肽-S转移酶)的活力(P<0.01),降低血浆中SOD(超氧化物岐化酶)、GSH-PX(谷胱苷肽过氧化物酶)的活性(P<0.01)和抑制羟基自由基的能力(P<0.05);(3)Diquat极显著增加脾脏MDA的含量(P<0.01),降低脾脏GST的含量(P<0.01),降低血浆中SOD、GSH-PX的活性和抑制羟基自由基的能力(P<0.01),提高MDA的含量(P<0.01)。氧化鱼油和Diquat可诱导断奶仔猪产生氧化应激,并导致了脾脏和胸腺的氧化损伤。  相似文献   
72.
为探讨NO/cGMP信号转导系统对小型猪特异性麻醉颉颃剂催醒分子机理的调控,144只Wistar大鼠随机分为对照组和试验组,对照组和试验组再分为早期催醒组、中期催醒组和晚期催醒组。用分光光度法测定脑NOS活性和NO产量,ELISA测定脑cGMP含量。结果显示,小型猪特异性麻醉颉颃剂能明显地激活大鼠相关脑区的NOS活性和NO及cGMP产量,并且大鼠不同脑区NOS活性、NO产量和cGMP含量的变化趋势不仅与大鼠行为学变化相平行,还与不同时期表现出的催醒效果基本吻合。这表明小型猪特异性麻醉颉颃剂的催醒可能与激活特定脑区的NO/cGMP信号转导系统相关。  相似文献   
73.
环丙沙星在猪体内的生物利用度及药物动力学   总被引:13,自引:2,他引:11  
18 头健康长白×大白×杜洛克杂交猪,分3 组,每组6 头,按5 m g/kg 的剂量进行了静注、肌注及内服环丙沙星的药动学研究。高效液相色谱法测定血浆中药物的质量浓度,MCPKP药代动力学程序处理药时数据。静注给药时,环丙沙星体内分布快且广泛,消除较慢,t1/2α为(0.35±0.19) h,t1/2β为(3.15±0.57) h,Vd(area)为(3.24±0.51) L/kg,ClB 为(0.73±0.15) L/(kg·h- 1 )。肌注和内服给药时,环丙沙星均吸收较快,但内服吸收速度和程度均不及肌注给药,t1/2ka 分别为(0.23±0.15)、(0.38±0 .21) h,tm ax 分别为(0.63±0.31)、(1.39±0.39) h,Cm ax 分别为(1.31±0.34)、(0.60±0.14) m g/L,生物利用度(F)分别为(77.96±5.89)% 、(51.58±5.69)% 。本研究发现,环丙沙星肌注和内服给药的消除半衰期与静注给药相似,分别为(3.45±0.66)、(3.32±0.96) h,与在其他哺乳动物的动力学特征有所不同。  相似文献   
74.
Epidemiology and control of Menangle virus in pigs   总被引:6,自引:0,他引:6  
OBJECTIVE: To describe the epidemiology and eradication of Menangle virus infection in pigs. DESIGN: Field observations and interventions, structured and unstructured serological surveys, prospective and cross-sectional serological studies and laboratory investigations. PROCEDURE: Serum samples were collected from pigs at a 2600-sow intensive piggery in New South Wales that experienced an outbreak of reproductive disease in 1997. Serum samples were also collected from piggeries that received pigs from or supplied pigs to the affected piggery and from other piggeries in Australia. Serum and tissue samples were collected from pigs at piggeries experiencing reproductive disease in New South Wales. Sera and faeces were collected from grey-headed flying foxes (Pteropus poliocephalus) in the region of the affected piggery. Serum samples were tested for neutralising antibodies against Menangle virus. Virus isolation was attempted from faeces. RESULTS: Following the outbreak of reproductive disease, sera from 96% of adult pigs at the affected piggery, including sows that produced affected litters, contained neutralising antibodies against Menangle virus. Neutralising antibodies were also detected in sera from 88% of finisher pigs at two piggeries receiving weaned pigs from the affected piggery. No evidence of Menangle virus infection was found in other piggeries in Australia. In cross-sectional studies at the affected piggery, colostral antibodies were undetectable in most pigs by 14 to 15 weeks of age. By slaughter age or entry to the breeding herd, 95% of pigs developed high antibody titres (> or = 128) against Menangle virus in the virus neutralisation test. Menangle virus was eradicated from the affected piggery following a program of serological testing and segregation. Neutralising antibodies against Menangle virus were also detected in P poliocephalus from two colonies in the vicinity of the affected piggery. Two piggery workers were infected with Menangle virus. There was no evidence of infection in cattle, sheep, birds, rodents, feral cats and a dog at the affected piggery. CONCLUSIONS: Serological evidence of infection with Menangle virus was detected in pigs at a piggery that had experienced reproductive disease, in pigs at two associated piggeries and in fruit bats in the region of the piggery. Two humans were infected. The mode of transmission between pigs is unknown, but spread by faecal or urinary excretion is postulated. This virus can be eradicated by the segregation of pigs into discrete age groups.  相似文献   
75.
In this paper, we describe the transmission of Classical Swine Fever virus (CSF virus) within herds during the 1997–1998 epidemic in the Netherlands. In seven herds where the infection started among individually housed breeding stock, all breeding pigs had been tested for antibodies to CSF virus shortly before depopulation. Based upon these data, the transmission of CSF virus between pigs was described as exponential growth in time with a parameter r, that was estimated at 0.108 (95% confidence interval (95% CI) 0.060–0.156). The accompanying per-generation transmission (expressed as the basic reproduction ratio, R0) was estimated at 2.9. Based upon this characterisation, a calculation method was derived with which serological findings at depopulation can be used to calculate the period in which the virus was with a certain probability introduced into that breeding stock. This model was used to estimate the period when the virus had been introduced into 34 herds where the infection started in the breeding section. Of these herds, only a single contact with a herd previously infected had been traced. However, in contrast with the seven previously mentioned herds, only a sample of the breeding pigs had been tested before depopulation (as was the common procedure during the epidemic). The observed number of days between the single contact with an infected herd and the day of sampling of these 34 herds fitted well in the model. Thus, we concluded that the model and transmission parameter was in agreement with the transmission between breeding pigs in these herds.

Because of the limited sample size and because it was usually unknown in which specific pen the infection started, we were unable to estimate transmission parameters for weaned piglets and finishing pigs from the data collected during the epidemic. However, from the results of controlled experiments in which R0 was estimated as 81 between weaned piglets and 14 between heavy finishing pigs (Laevens et al., 1998a. Vet. Quart. 20, 41–45; Laevens et al., 1999. Ph.D. Thesis), we constructed a simple model to describe the transmission of CSF virus in compartments (rooms) housing finishing pigs and weaned piglets. From the number of pens per compartment, the number of pigs per pen, the numbers of pigs tested for antibodies to CSF virus and the distribution of the seropositive pigs in the compartment, this model gives again a period in which the virus most probably entered the herd. Using the findings in 41 herds where the infection started in the section of the finishers or weaned piglets of the age of 8 weeks or older, and of which only a single contact with a herd previously infected was known, there was no reason to reject the model. Thus, we concluded that the transmission between weaned piglets and finishing pigs during the epidemic was not significantly different from the transmission observed in the experiments.  相似文献   

76.
Neutrophils are an important mediator of host defence, especially in early stages of infection. A major function of neutrophils is the uptake and killing of invading microbes. Little is known about the effect of neutrophil activity on the pathogenesis and development of the carrier state in swine following infection with Salmonella choleraesuis. A human whole-blood microassay using flow cytometry was modified to measure the effect of S. choleraesuis infection in vivo on the rate of ingestion, or rate of uptake, of homologous bacteria by porcine neutrophils. Pigs were inoculated intranasally with 5–8×108 CFU S. choleraesuis and blood was collected in heparinized tubes at –5, 0, 1, 2, 3 and 4 days post inoculation (PI). Heat-killed S. choleraesuis were labelled with fluorescein isothiocyanate and incubated for various times with diluted whole blood. Red blood cells were lysed, external non-phagocytized bacteria were quenched with a commercially available lysing solution, and fluorescence from internalized bacteria labelled with fluorescein isothiocyanate was detected by flow cytometry. The rate of uptake by neutrophils did not increase until 2 days PI and then remained elevated to 4 days PI. The minimal uptake of S. choleraesuis early after exposure to these organisms may provide an opportunity for the pathogen to colonize and/or replicate to levels that facilitate establishment of a carrier state or clinical infection in swine.  相似文献   
77.
A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8 μg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256 μg/ml (62 strains) and 512 μg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.  相似文献   
78.
滇南小耳猪与巴马小型猪SLA-DQA基因多态分析   总被引:8,自引:2,他引:8  
对滇南小耳猪和巴马小型猪的SLA-DQA基因的部分内含子1、完整的外显子2和部分内含子2共341bp片段进行了PCR-RFLP酶切分型,结果表明:2品种经EcoR Ⅰ酶切后BB基因型频率(0.468 8)高于AB型(0.375 0),AA型最低(0.156 3),B为优势基因(0.656 3),A为劣势基因(0.343 7).经AluⅠ酶切后,滇南小耳猪MM基因型频率(0.500 0)高于MN型(0.321 4)和NN型(0.178 6);而巴马猪则以MN基因型频率(0.485 3)高于MM型(0.338 2)和NN型(0.176 5);2个品种中M等位基因(0.604 2)频率高于N等位基因(0.395 8).经分析表明,2猪种在两酶切位点上各分型已达Hardy-Weinberg平衡.巴马小型猪和滇南小耳猪中分别存在9种和7种PCR-RFLP组合基因型,其中BBMN为优势组合基因型,AAMN为劣势组合基因型;AAMM组合基因型在2品种间差异显著(P<0.05).遗传多态参数分析表明:SLA-DQA基因外显子2的两酶切位点在2猪种间均表现为中度多态,AluⅠ的基因多样性略高于EcoRⅠ,巴马小型猪杂合性略高于滇南小耳猪,2品种间遗传距离为0.000 4.  相似文献   
79.
An experiment was conducted to investigate the effect of dietary betaine supplementation on carcass characteristics, hormones, growth factor and lipid metabolism in finishing pigs. Forty-eight crossbred barrows and gilts (Seghers × Seghers × Duroc) weighing about 55 kg were divided into two groups, each with three replicates of eight pigs (four barrows and four gilts) per replicate, and fed corn–soybean meal basal diets supplemented with 0 and 0.125% betaine for 42 days. At trial termination, two pigs (one barrow and one gilt) weighing about 90 kg were selected from each replicate and slaughtered for analyses. The results showed that betaine increased carcass lean percentage and longissimus muscle area by 5.19% (P < 0.01) and 17.85% (P < 0.01), respectively, and decreased carcass fat percentage and average backfat thickness by 13.07% (P < 0.01) and 10.30% (P < 0.05), respectively. Serum growth hormone, insulin-like growth factor I, free triiodothyronine, free thyroxine and insulin levels in pigs fed betaine were elevated by 45.61% (P < 0.01), 55.50% (P < 0.01), 57.95% (P < 0.01), 51.80% (P < 0.01) and 42.34% (P < 0.05), respectively. Fatty acid synthase activity in the 10th rib subcutaneous adipose tissue was decreased by 24.35% (P < 0.05) with betaine supplementation, whereas hormone-sensitive lipase activity was significantly increased (P < 0.05). Meanwhile, serum free fatty acids concentration in betaine-fed pigs was 25.75% higher compared to controls (P < 0.01). The study suggested that betaine could induce changes in hormones and growth factor in finishing pigs, and therefore could inhibit fat synthesis through reducing lipogenic enzymes activities and promote fat degradation by increasing hormone-sensitive lipase activity, with a resultant decrease in adipose tissue mass and improvement in carcass characteristics.  相似文献   
80.
将48头杜×长×大三元杂交生长猪随机分为两组,分别饲喂正常磷水平日粮和无磷酸氢钙日粮,结果表明:与正常磷水平日粮相比,无磷酸氢钙日粮可显著提高磷的表观消化率(P<0.05),增加猪场的纯收入,减少粪中磷的排放以保护猪场周边的生态环境。  相似文献   
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