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1.
A 2-D gel electrophoretic method, consisting of isoelectric focusing and alkaline urea-PAGE was used to monitor proteolysis during ripening (180d, 5°C and 8°C) of full- and reduced-fat Cheddar cheese. The method enabled quantifying changes in levels of peptides in cheese with good spot-resolution. Results can complement those from other analyses, especially those for determining low MW peptides. Notable effects were found for cheese composition and ripening temperature on gel pattern and on relative levels of selected proteolysis products. In both cheese varieties, most peptides reached a maximum during the first 3 ripening months and gradually disappeared as ripening advanced. 相似文献
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Joanna Gruszczynska-Biegala Andrzej Stefan Andrzej A. Kasprzak Piotr Dobryszycki Sofia Khaitlina Hanna Strzelecka-Goaszewska 《International journal of molecular sciences》2021,22(5)
Formation of stable actin filaments, critically important for actin functions, is determined by the ionic strength of the solution. However, not much is known about the elements of the actin fold involved in ionic-strength-dependent filament stabilization. In this work, F-actin was destabilized by Cu2+ binding to Cys374, and the effects of solvent conditions on the dynamic properties of F-actin were correlated with the involvement of Segment 227-235 in filament stabilization. The results of our work show that the presence of Mg2+ at the high-affinity cation binding site of Cu-modified actin polymerized with MgCl2 strongly enhances the rate of filament subunit exchange and promotes the filament instability. In the presence of 0.1 M KCl, the filament subunit exchange was 2–3-fold lower than that in the MgCl2-polymerized F-actin. This effect correlates with the reduced accessibility of the D-loop and Segment 227-235 on opposite filament strands, consistent with an ionic-strength-dependent conformational change that modulates involvement of Segment 227-235 in stabilization of the intermonomer interface. KCl may restrict the mobility of the α-helix encompassing part of Segment 227-235 and/or be bound to Asp236 at the boundary of Segment 227-235. These results provide experimental evidence for the involvement of Segment 227-235 in salt-induced stabilization of contacts within the actin filament and suggest that they can be weakened by mutations characteristic of actin-associated myopathies. 相似文献
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Arun Pandian Chandrasekaran Sang Hyeon Woo Neha Sarodaya Byung Ho Rhie Apoorvi Tyagi Soumyadip Das Bharathi Suresh Na Re Ko Seung Jun Oh Kye-Seong Kim Suresh Ramakrishna 《International journal of molecular sciences》2021,22(11)
Cell division cycle 25A (Cdc25A) is a dual-specificity phosphatase that is overexpressed in several cancer cells and promotes tumorigenesis. In normal cells, Cdc25A expression is regulated tightly, but the changes in expression patterns in cancer cells that lead to tumorigenesis are unknown. In this study, we showed that ubiquitin-specific protease 29 (USP29) stabilized Cdc25A protein expression in cancer cell lines by protecting it from ubiquitin-mediated proteasomal degradation. The presence of USP29 effectively blocked polyubiquitination of Cdc25A and extended its half-life. CRISPR-Cas9-mediated knockdown of USP29 in HeLa cells resulted in cell cycle arrest at the G0/G1 phase. We also showed that USP29 knockdown hampered Cdc25A-mediated cell proliferation, migration, and invasion of cancer cells in vitro. Moreover, NSG nude mice transplanted with USP29-depleted cells significantly reduced the size of the tumors, whereas the reconstitution of Cdc25A in USP29-depleted cells significantly increased the tumor size. Altogether, our results implied that USP29 promoted cell cycle progression and oncogenic transformation by regulating protein turnover of Cdc25A. 相似文献
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为获得有抗氧化活性的工业用酵母菌株,对2株来源于原料乳中有较强抗氧化活性的酵母菌进行鉴定.根据菌株的表型、生理生化特征和基因型的特性,初步将这2株菌鉴定为毕赤氏发酵酵母(Pichia fermentans).将这2株酵母菌在高温灭菌(UHT)牛乳中培养以研究其对牛乳主要成分的影响,结果表明:这2株酵母能在UHT牛乳中产乙醇,具有促进蛋白水解活性与脂肪水解活性的能力,能有效提高乳中的游离氨基酸和脂肪酸的含量. 相似文献
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Mansour Shakerian Seyed Hadi Razavi Faramarz Khodaiyan Seyed Ali Ziai Mohammad Saeid Yarmand Ali Moayedi 《International Journal of Food Science & Technology》2014,49(1):261-268
Effects of different levels of fat and inulin on bacterial cell counts, degree of proteolysis and concentrations of organic acids in the yogurt containing inactivated cells of probiotic strains Bifidobacterium animalis and Lactobacillus acidophilus were investigated. Results showed that both L. acidophilus and B. animalis grew well in the yogurt samples reaching cell counts higher than 106 CFU mL?1 at the final pH of 4.5. Inulin at the concentration of 1% had no significant effects on the production of organic acids and cell counts of L. acidophilus, but promoted the growth of B. animalis with a reduction in the degree of proteolysis. Generally, different fat levels showed significant effects on the production of organic acids and nonsignificant effects on the cell counts of probiotic bacteria and degree of proteolysis. In case of lactic acid, the ratio of L‐ (+)to D‐ (?) isomer ranged from 50/50 to 80/20 in yogurt samples. 相似文献
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UHT乳贮存中常见问题及其原因分析 总被引:12,自引:3,他引:9
UHT乳作为“营养全价”食品倍受消费者喜爱。但是UHT乳在贮藏中容易出现一些质量问题,常见的有:脂肪上浮、形成沉淀和凝胶、乳清析出、酸包和胀包及色香味的改变等。针对以上问题进行了论述,并探讨了产生的原因及相应的预防措施。 相似文献
10.
Large and small starch granules prepared from Proctor barley contain high levels of firmly bound protein. Experiments with α-amylase under simulated mashing conditions suggest that this protein limits the rate of starch breakdown during mashing. Gel electrophoresis shows hordein to be a principal component. Treatment with cysteine or malt endopeptidase changes the nature of the associated protein. 相似文献