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排序方式: 共有200条查询结果,搜索用时 15 毫秒
81.
Hau J Hendriksen CF 《ILAR journal / National Research Council, Institute of Laboratory Animal Resources》2005,46(3):294-299
Polyclonal antibody production in mammals is generally associated with multiple injections of antigens and adjuvants and repeated blood sampling procedures. During the past 20 yr, the use of chickens instead of mammals for this purpose has increased. A major advantage of using birds is that the antibodies can be harvested from the egg yolk instead of serum, thus making blood sampling obsolete. In addition, the antibody productivity of an egg-laying hen is much greater than that of a similar sized mammal. This article focuses on the developments in oral immunization strategies for chickens that combined with the antibodies from the egg yolk, have great potential for active implementation of the three Rs (replacing, reducing, and refining the use of laboratory animals to the extent possible) in polyclonal antibody production schemes. 相似文献
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83.
Expression and characterization of UDPGlc dehydrogenase (KfiD), which is encoded in the type-specific region 2 of the Escherichia coli K5 capsule genes. 总被引:2,自引:2,他引:0 下载免费PDF全文
Region 2 of the Escherichia coli K5 capsule gene cluster contains four genes (kfiA through -D) which encode proteins involved in the synthesis of the K5 polysaccharide. A DNA fragment containing kfiD was amplified by PCR and cloned into the gene fusion vector pGEX-2T to generate a GST-KfiD fusion protein. The fusion protein was isolated from the cytoplasms of IPTG (isopropyl-beta-D-thiogalactopyranoside)-induced recombinant bacteria by affinity chromatography and cleaved with thrombin. The N-terminal amino acid sequence of the cleavage product KfiD' corresponded to the predicted amino acid sequence of KfiD with an N-terminal glycyl-seryl extension from the cleavage site of the fusion protein. Anti-KfiD antibodies obtained with KfiD' were used to isolate the intact KfiD protein from the cytoplasms of E. coli organisms overexpressing the kfiD gene. The fusion protein, its cleavage product (KfiD'), and overexpressed KfiD converted UDPGlc to UDPGlcA. The KfiD protein could thus be characterized as a UDPglucose dehydrogenase. 相似文献
84.
The structure of the K40 antigenic capsular polysaccharide (K40 antigen) of E. coli O8:K40:H9 was elucidated by determination of the composition, 1H- and 13C-n.m.r. spectroscopy, periodate oxidation and Smith degradation, and methylation analysis. The K40 polysaccharide consists of [(O-β-
-glucopyranosyluronic acid)-(1→4)-O-(2-acetamido-2-deoxy--
-glucopyranosyl)-(1→6)-O-(2-acetamido-2-deoxy--
-glucopyranosyl)-(1→4)] repeating units. All of the glucuronic acid residues are substituted amidically with
-serine. 相似文献
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87.
Chiara Pastori Mark Daniel Clara Penas Claude-Henry Volmar Andrea L Johnstone Shaun P Brothers Regina M Graham Bryce Allen Jann N Sarkaria Ricardo J Komotar Claes Wahlestedt Nagi G Ayad 《Epigenetics》2014,9(4):611-620
Epigenetic proteins have recently emerged as novel anticancer targets. Among these, bromodomain and extra terminal domain (BET) proteins recognize lysine-acetylated histones, thereby regulating gene expression. Newly described small molecules that inhibit BET proteins BRD2, BRD3, and BRD4 reduce proliferation of NUT (nuclear protein in testis)-midline carcinoma, multiple myeloma, and leukemia cells in vitro and in vivo. These findings prompted us to determine whether BET proteins may be therapeutic targets in the most common primary adult brain tumor, glioblastoma (GBM). We performed NanoString analysis of GBM tumor samples and controls to identify novel therapeutic targets. Several cell proliferation assays of GBM cell lines and stem cells were used to analyze the efficacy of the drug I-BET151 relative to temozolomide (TMZ) or cell cycle inhibitors. Lastly, we performed xenograft experiments to determine the efficacy of I-BET151 in vivo. We demonstrate that BRD2 and BRD4 RNA are significantly overexpressed in GBM, suggesting that BET protein inhibition may be an effective means of reducing GBM cell proliferation. Disruption of BRD4 expression in glioblastoma cells reduced cell cycle progression. Similarly, treatment with the BET protein inhibitor I-BET151 reduced GBM cell proliferation in vitro and in vivo. I-BET151 treatment enriched cells at the G1/S cell cycle transition. Importantly, I-BET151 is as potent at inhibiting GBM cell proliferation as TMZ, the current chemotherapy treatment administered to GBM patients. Since I-BET151 inhibits GBM cell proliferation by arresting cell cycle progression, we propose that BET protein inhibition may be a viable therapeutic option for GBM patients suffering from TMZ resistant tumors. 相似文献
88.
Summary This brief review of the science and practice of ecological restoration and rehabilitation in Australia shows that, from small isolated efforts in the first half of the 20th century, substantial numbers of programmes are steadily emerging from natural area, agricultural landscape, mining and aquatic management sectors. With support from numerous research programmes in the last two decades, restoration and rehabilitation work is increasing in scale and ecological rigour; and researchers and practitioners are increasingly engaging with the international restoration discourse. Future improvements in prioritization, goal-setting, monitoring, evaluation and communication are, however, still needed to improve Australia's capacity to meet its increasingly serious environmental challenges and do its bit to reduce and halt global degradation. 相似文献
89.
Otto Kalliokoski Kirsten R. Jacobsen Huda S. Darusman Trine Henriksen Allan Weimann Henrik E. Poulsen Jann Hau Klas S. P. Abelson 《PloS one》2013,8(3)
The metabolism cage is a barren, non-enriched, environment, combining a number of recognized environmental stressors. We investigated the ability of male BALB/c mice to acclimatize to this form of housing. For three weeks markers of acute and oxidative stress, as well as clinical signs of abnormality were monitored. Forced swim tests were conducted to determine whether the animals experienced behavioral despair and the serotonergic integrity was tested using an 8-OH-DPAT challenge. The metabolism cage housed mice excreted approximately tenfold higher amounts of corticosterone metabolites in feces throughout the study when compared to controls. Urinary biomarkers confirmed that these mice suffered from elevated levels of oxidative stress, and increased creatinine excretions indicated increased muscle catabolism. Changes in the core body temperature (stress-induced hyperthermia) and the fur state of the mice also indicated impaired well-being in the metabolism cage housed mice. However, monitoring body weight and feed intake was found misleading in assessing the wellbeing of mice over a longer time course, and the forced swim test was found poorly suited for studying chronic stress in mice in the present setup. In conclusion, the mice were found not to acclimatize to the metabolism cages whereby concern for animal welfare would dictate that mice should be housed in this way for as short periods as possible. The elevated degree of HPA axis activity, oxidative stress, and increased overall metabolism warrant caution when interpreting data obtained from metabolism cage housed mice, as their condition cannot be considered representative of a normal physiology. 相似文献
90.
Hau J Kalliokoski O Jacobsen K Abelson K 《Laboratory animals》2011,45(2):129; author reply 129-129; author reply 130