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1.
The objective of the present study was to evaluate the effects of low-molecular-weight chitosan (LMWC) on the growth performance, immune responses and intestinal health of weaned pigs challenged by enterotoxigenic Escherichia coli (ETEC). A total of 32 weaned pigs were randomly allocated to four treatments: non-challenged (fed with basal diet), ETEC-challenged (fed with basal diet) and ETEC-challenged plus 50 or 100 mg/kg LMWC supplementation, respectively. After 11 days feeding, the non-challenged pigs were infused with sterilised Luria–Bertani culture, while the remaining pigs were infused with 2.6 × 1011 colony-forming units of ETEC. At 3 days post-challenge, all pigs were administered d-xylose at 0.1 g/kg body weight. One hour later, blood samples were obtained, and the pigs then euthanised to collect intestinal samples. Data showed that only 100 mg/kg LMWC supplementation attenuated (P < 0.05) the average daily gain reduction caused by ETEC. Furthermore, besides the decreased (P < 0.05) serum tumour necrosis factor-α and immunoglobulin (Ig) G concentrations detected in ETEC-challenged pigs supplemented with LMWC at 50 or 100 mg/kg, the higher dose (100 mg/kg) also decreased (P < 0.05) the serum IgM concentration and increased (P < 0.05) the villus height and villus height-to-crypt depth ratio in both the jejunum and ileum, and the sucrase activity in the ileal mucosa. Moreover, LMWC supplementation (50 or 100 mg/kg) in ETEC-challenged pigs elevated (P < 0.05) the mRNA levels of jejunal mucosal peptide transporter 1 and ileal mucosal peptide transporter 1, divalent metal transporter 1 and zinc transporter 1, and decreased (P < 0.05) the ileal and caecal E. coli abundances, while 100 mg/kg LMWC additionally elevated (P < 0.05) the ileal Bacillus abundance, and caecal and colonic Bifidobacterium abundances. These results suggest that LMWC helps alleviate ETEC-induced growth retardation in weaned pigs, which could be associated with the inhibition of the immune responses and improved intestinal health. 相似文献
2.
Yadnyavalkya Patil 《Gut microbes》2020,11(3):310-334
ABSTRACT It is well established that pig gut microbiota plays a critical role in maintaining metabolic homeostasis as well as in a myriad of physiological, neurological and immunological functions; including protection from pathogens and digestion of food materials – some of which would be otherwise indigestible by the pig. A rich and diverse gut microbial ecosystem (balanced microbiota) is the hallmark of good health; while qualitative and quantitative perturbations in the microbial composition can lead to development of various diseases. Alternatively, diseases caused by stressors or other factors have been shown to negatively impact the microbiota. This review focuses primarily on how commensal microorganisms in the gastrointestinal tract of pigs influence biochemical, physiological, immunological, and metabolic processes within the host animal. 相似文献
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Aleksandra Wo
niak Dagmara Miek Piotr Bska Tomasz Stadejek 《Transboundary and Emerging Diseases》2019,66(4):1454-1461
PCV2 is globally spread pathogen involved in a number of diseases (PCVD). Commonly used vaccines against PCV2 are proved to be highly efficacious. The role of recently discovered PCV3 for pig health and interference with PCV2 remains unknown. The study performed on serum samples from seven farms vaccinated against PCV2 and four non‐vaccinated showed very low prevalence of PCV2 viremia in the former (3 out of 106 positive serum pools) and high prevalence of PCV2 viremia in the latter (35 out of 60 positive pools). Mean log10 PCV2 genome equivalents were lower in vaccinated farms (4.8 ± 0.6 log10 copies/ml) than in non‐vaccinated farms (6.3 ± 1.3 log10 copies/ml). PCV3 was detected in 31 out of 106 and 12 out of 60 serum pools from vaccinated and non‐vaccinated farms, respectively. Mean log10 PCV3 genome equivalents were significantly (p < 0.05) lower in vaccinated farms (3.9 ± 0.8 log10 copies/ml) than in non‐vaccinated farms (4.4 ± 0.6 log10 copies/ml). Concurrent PCV2 and PCV3 infection was rare and found only in 1 out of 529 and 4 out of 292 individual serum samples from vaccinated and non‐vaccinated farms, respectively. Our results showed lack of impact of PCV3 circulation on PCV2 vaccine efficacy. On the other hand, intensive PCV2 circulation and high viremia detected in non‐vaccinated farms did not seem to increase the level of PCV3 infection. 相似文献
6.
融水小型猪的种源来自广西融水县,2012年被引到广东繁育并测定了基础数据,包括种质特性、繁殖性能、生长曲线、血液学指标、血生化指标、脏器系数、染色体分析。参照国家和地方有关实验动物标准,初步建立了融水小型猪微生物与寄生虫、环境与设施、饲料、病理学、遗传学等质量控制标准。融水小型猪能适应当地气候,繁殖良好,自然受孕率为88.3%,妊娠期平均112 d,初产平均胎产仔6.1头,经产平均产仔7.9头。融水小型猪体型小,雌雄成年体重(6月龄)分别为17.21±5.20 kg和16.35±5.23 kg,性情温顺,线粒体DNA分析表明融水小型猪比兰屿猪更为古老。通过标准化的饲养管理与质量控制,具有培育成实验用小型猪的基本条件。 相似文献
7.
目的掌握融水小型猪主要器官解剖学及组织学数据。方法选择6月龄F1代小型猪雌雄各两头,麻醉后测体重,进行大体解剖,颈动脉取血测定全身血量、血浆量,记录脊柱数量和恒齿齿式,取出主要脏器进行拍照、称重及测量,切取脏器的部分组织,用福尔马林固定后做组织切片,在显微镜下观察并拍照。结果获得了融水小型猪的主要脏器形态图片、组织学显微图片、主要脏器重量、脏器系数及其他基础数据。结论初步掌握了融水小型猪的器官解剖学和组织学基础数据。 相似文献
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高梅 《中国比较医学杂志》2015,25(9):51-55
目的 比较两种阳性物质人血白蛋白、卵白蛋白对豚鼠主动全身过敏作用,为过敏性试验提供较好的阳性对照。方法 将豚鼠随机分为14组,以人血白蛋白、卵白蛋白(2、10、100 mg/只)、0.9%氯化钠注射液等受试物为对照,研究不同致敏剂量、激发剂量、激发时间等条件下,豚鼠全身主动过敏的反应情况。结果 在2~100 mg/只剂量范围内,人血白蛋白、卵白蛋白豚鼠主动全身过敏反应的发生率为100%。在2~10 mg/只剂量范围内,过敏症状发生程度随致敏剂量、激发剂量的增加而增加,相同剂量的卵白蛋白较人血白蛋白反应程度更强。结论 豚鼠主动全身过敏试验,阳性对照推荐使用卵白蛋白,剂量为2 mg/只。 相似文献
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