全文获取类型
收费全文 | 766篇 |
免费 | 70篇 |
学科分类
工业技术 | 836篇 |
出版年
2024年 | 8篇 |
2023年 | 14篇 |
2022年 | 50篇 |
2021年 | 64篇 |
2020年 | 29篇 |
2019年 | 45篇 |
2018年 | 37篇 |
2017年 | 27篇 |
2016年 | 36篇 |
2015年 | 27篇 |
2014年 | 43篇 |
2013年 | 73篇 |
2012年 | 68篇 |
2011年 | 76篇 |
2010年 | 36篇 |
2009年 | 35篇 |
2008年 | 38篇 |
2007年 | 32篇 |
2006年 | 26篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1968年 | 3篇 |
排序方式: 共有836条查询结果,搜索用时 15 毫秒
21.
Vanessa Reusche Prof. Dr. Franziska Thomas 《Chembiochem : a European journal of chemical biology》2021,22(10):1779-1783
A two-step synthesis for methionine-containing hydrophobic and/or aggregation-prone peptides is presented that takes advantage of the reversibility of methionine oxidation. The use of polar methionine sulfoxide as a building block in solid-phase peptide synthesis improves the synthesis quality and yields the crude peptide, with significantly improved solubility compared to the reduced species. This facilitates the otherwise often laborious peptide purification by high-performance liquid chromatography. The subsequent reduction proceeds quantitatively. This approach has been optimised with the methionine-rich Tar-DNA-binding protein 43 (307–347), but is also more generally applicable, as demonstrated by the syntheses of human calcitonin and two aggregation-prone peptides from the human prion protein. 相似文献
22.
Vanessa Modelski Schatkoski Thaís Larissa do Amaral Montanheiro Beatriz Rossi Canuto de Menezes Raissa Monteiro Pereira Karla Faquine Rodrigues Renata Guimarães Ribas Diego Morais da Silva Gilmar Patrocínio Thim 《Ceramics International》2021,47(3):2999-3012
Studies related to biomaterials that stimulate the repair of living tissue have increased considerably, improving the quality of many people's lives that require surgery due to traumatic accidents, bone diseases, bone defects, and reconstructions. Among these biomaterials, bioceramics and bioactive glasses (BGs) have proved to be suitable for coating materials, cement, scaffolds, and nanoparticles, once they present good biocompatibility and degradability, able to generate osteoconduction on the surrounding tissue. However, the role of biomaterials in hard tissue engineering is not restricted to a structural replacement or for guiding tissue regeneration. Nowadays, it is expected that biomaterials develop a multifunctional role when implanted, orchestrating the process of tissue regeneration and providing to the body the capacity to heal itself. In this way, the incorporation of specific metal ions in bioceramics and BGs structure, including magnesium, silver, strontium, lithium, copper, iron, zinc, cobalt, and manganese are currently receiving enhanced interest as biomaterials for biomedical applications. When an ion is incorporated into the bioceramic structure, a new category of material is created, which has several unique properties that overcome the disadvantages of primitive material and favors its use in different biomedical applications. The doping can enhance handling properties, angiogenic and osteogenic performance, and antimicrobial activity. Therefore, this review aims to summarize the effect of selected metal ion dopants into bioceramics and silicate-based BGs in bone tissue engineering. Furthermore, new applications for doped bioceramics and BGs are highlighted, including cancer treatment and drug delivery. 相似文献
23.
Effects of feeding conjugated linoleic acid (CLA) to hens on progeny chick development and composition at hatch (NHC) and
three weeks of age (TWC) were assessed. CLA (0 or 0.5%, composed of mixed isomers of cis-9,trans-11 or trans-10,cis-12-CLA) was fed to hens with either safflower (SO) or olive oil (OO) (3 or 3.5%) to assure successful hatch for 2 weeks prior
to collection for incubation. Maternal CLA feeding had no effect on hatchability, but improved egg fertility (p < 0.05). Maternal feeding of CLA with SO increased 21 day-old progeny growth, while CLA with OO decreased growth (oil*CLA,
p < 0.05). In 25 day-old chicks (TWC), but not NHC, maternal CLA decreased the proportion of total body water (p < 0.05) and increased body ash (p < 0.05). While monounsaturated fatty acids were decreased and saturated fatty acids increased in eggs and NHC from hens fed
CLA, no differences in fatty acid composition were observed in chicks at 25 days of age from hens fed CLA. Maternal CLA feeding
resulted in the presence of c9,t11 and t10,c12-CLA in NHC, but only c9,t11 in the TWC. In conclusion, hens fed CLA led to improved fertility and altered body composition at 3 weeks of age. 相似文献
24.
Dietary Mannan Oligosaccharides Modulate Gut Microbiota,Increase Fecal Bile Acid Excretion,and Decrease Plasma Cholesterol and Atherosclerosis Development 下载免费PDF全文
Lisa R. Hoving Saeed Katiraei Marieke Heijink Amanda Pronk Lianne van der Wee‐Pals Trea Streefland Martin Giera Ko Willems van Dijk Vanessa van Harmelen 《Molecular nutrition & food research》2018,62(10)
1 Scope
Mannan oligosaccharides (MOS) have proven effective at improving growth performance, while also reducing hyperlipidemia and inflammation. As atherosclerosis is accelerated both by hyperlipidemia and inflammation, we aim to determine the effect of dietary MOS on atherosclerosis development in hyperlipidemic ApoE*3‐Leiden.CETP (E3L.CETP) mice, a well‐established model for human‐like lipoprotein metabolism.2 Methods and results
Female E3L.CETP mice were fed a high‐cholesterol diet, with or without 1% MOS for 14 weeks. MOS substantially decreased atherosclerotic lesions up to 54%, as assessed in the valve area of the aortic root. In blood, IL‐1RA, monocyte subtypes, lipids, and bile acids (BAs) were not affected by MOS. Gut microbiota composition was determined using 16S rRNA gene sequencing and MOS increased the abundance of cecal Bacteroides ovatus. MOS did not affect fecal excretion of cholesterol, but increased fecal BAs as well as butyrate in cecum as determined by gas chromatography mass spectrometry.3 Conclusion
MOS decreased the onset of atherosclerosis development via lowering of plasma cholesterol levels. These effects were accompanied by increased cecal butyrate and fecal excretion of BAs, presumably mediated via interactions of MOS with the gut microbiota. 相似文献25.
Erwan Diler Vanessa Leblanc Hervé Gueuné Nicolas Larché Valerie Deydier Yannick Linard Didier Crusset Dominique Thierry 《工业材料与腐蚀》2021,72(1-2):218-234
In the context of the high-level radioactive waste disposal CIGEO, the corrosion rate due to microbially influenced corrosion (MIC) has to be evaluated. In France, it is envisaged to dispose of high- and intermediate-level long-lived radioactive waste at a depth of 500 m in a deep geological disposal, drilled in the Callovo-Oxfordian claystone (Cox) formation. To do so, a carbon steel casing will be inserted inside disposal cells, which are horizontal tunnels drilled in the Cox. A specific cement grout will be injected between the carbon steel casing and the claystone. A study was conducted to evaluate the possibility of MIC on carbon steel in the foreseeable high radioactive waste disposal. The corrosiveness of various environments was investigated at 50°C and 80°C with or without microorganisms enriched from samples of Andra's underground research laboratory. The monitoring of corrosion during the experiments was ensured using gravimetric method and real-time corrosion monitoring using sensors based on the measurements of the electrical resistance. The corrosion data were completed with microbiological analyses including cultural and molecular characterizations. 相似文献
26.
We analyze the behavior of a dense granular aggregate made by identical, elastic spheres, uni-axially compressed at constant pressure. Our goal is to predict the evolution of the effective moduli along the loading path when small perturbations are applied to stressed states. The analytical model is based upon the average strain theory. We show that the moduli in the anisotropic state normalized with the corresponding initial isotropic value, are captured by a so crude model. Numerical simulations support this result. 相似文献
27.
Guadalupe Aparicio Gallego Vanessa Medina Villaamil Enrique Grande Isabel Santamarina Ca��nzos Lu��s M. Ant��n Aparicio 《International journal of molecular sciences》2012,13(10):12710-12733
Historically, cell-signaling pathways have been studied as the compilation of isolated elements into a unique cascade that transmits extracellular stimuli to the tumor cell nucleus. Today, growing evidence supports the fact that intracellular drivers of tumor progression do not flow in a single linear pathway, but disseminate into multiple intracellular pathways. An improved understanding of the complexity of cancer depends on the elucidation of the underlying regulatory networks at the cellular and intercellular levels and in their temporal dimension. The high complexity of the intracellular cascades causes the complete inhibition of the growth of one tumor cell to be very unlikely, except in cases in which the so-called “oncogene addiction” is known to be a clear trigger for tumor catastrophe, such as in the case of gastrointestinal stromal tumors or chronic myeloid leukemia. In other words, the separation and isolation of the driver from the passengers is required to improve accuracy in cancer treatment. This review will summarize the signaling pathway crossroads that govern renal cell carcinoma proliferation and the emerging understanding of how these pathways facilitate tumor escape. We outline the available evidence supporting the putative links between different signaling pathways and how they may influence tumor proliferation, differentiation, apoptosis, angiogenesis, metabolism and invasiveness. The conclusion is that tumor cells may generate their own crossroads/crosstalk among signaling pathways, thereby reducing their dependence on stimulation of their physiologic pathways. 相似文献
28.
Jorge Moreda–Piñeiro Elia Alonso-Rodríguez Vanessa Romarís-Hortas Antonio Moreda-Piñeiro Purificación López-Mahía Soledad Muniategui-Lorenzo Darío Prada-Rodríguez Pilar Bermejo-Barrera 《Food chemistry》2012,130(3):552-560
Bioavailability of total arsenic, toxic (arsenite, As(III); and arsenate, As(V)), and non-toxic (monomethylarsonic acid, MA; dimethylarsonic acid, DMA; arsenobetaine, AB; and arsenocholine, AC) arsenic species has been assessed in different raw seafood samples (white fish, cold water fish and molluscs) by using an in vitro model that combines simulated gastric and intestinal digestion/dialysis methods. Correlations between arsenic species bioavailability and seafood nutrient contents (fat and protein) have also been established. Total arsenic content in seafood samples, and dialyzable and non-dialyzable fractions, were analyzed by inductively coupled plasma – mass spectrometry (ICP–MS) after a microwave-assisted acid digestion treatment. The determination of the different arsenic species concentrations in the samples (after an optimised matrix solid phase dispersion (MSPD) approach) and in the dialyzable fraction was done by high performance liquid chromatography (HPLC) coupled to ICP-MS as a selective detector. Accuracy of the procedure (total arsenic determination) was assessed by analyzing DORM-2 and BCR-627 certified reference materials. The accuracy of the in vitro procedure was established through a mass-balance study. After statistical evaluation (95% confidence interval), good accuracy of the whole in vitro process, for total arsenic and for arsenic speciation, was observed. High dialyzability percentages for total arsenic and for arsenic species were found (i.e. from 84.6 ± 1.7% to 106 ± 2.6%). Bioavailability of arsenic exhibits a negative correlation with the fat content of the seafood. However, no correlation was observed between the bioavailable fraction of total arsenic and arsenic species and the protein content of the seafood studied. 相似文献
29.
Vanessa Migliorini Urban Ana Lucia Machado Carlos Eduardo Vergani Eunice Teresinha Giampaolo Ana Cláudia Pavarina Quezia Bezerra Cass 《应用聚合物科学杂志》2012,123(2):732-739
The effect of a post‐polymerization treatment on the leaching of methacrylic acid (MA) and benzoic acid (BA) from the reline resins [Kooliner (K), New Truliner (N), Ufi Gel hard (U), and Tokuso Rebase Fast (T)] was evaluated. Specimens of each material were divided into two groups: Group C (control) – left untreated; Group WB (water‐bath) – immersion in water at 55 ± 1°C for 10 min. Specimens were placed in artificial saliva at 37 ± 1°C and, after 1‐, 3‐, 5‐, 24‐h and 3‐, 7‐, 14‐, and 30‐day intervals, aliquots were removed and analyzed using high performance liquid chromatography. Data were analyzed by using Wilcoxon, Mann–Whitney or Kruskal–Wallis tests (α = 0.05). At 1 h, the concentration of MA released from U control specimens was higher than those of the other ones, and decreased after 3 h. WB specimens released lower amounts of MA than control specimens only for material U, at the 1‐ and 3‐h periods. For all control specimens, concentrations of leached BA progressively decreased within 5 h and from 24 h to the end. WB specimens released significantly lower amounts of BA than did the control groups. The highest concentration of MA was leached from control specimens of Ufi Gel hard. Water‐bath post‐polymerization treatment caused a significant reduction in elution of BA. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
30.
Sergio Gómez-Alonso Vanessa J. Collins David Vauzour Ana Rodríguez-Mateos Giulia Corona Jeremy P.E. Spencer 《Food chemistry》2012,130(3):493-500
The moderate consumption of red wine has been proposed to reduce the incidence of colorectal cancer. Its anti-cancer action my in part be mediated by the actions of polyphenols on colon cancer epithelial cells. We show that a red wine phenolic (50 μg/ml) extract devoid of anthocyanins (removed to reflect polyphenol bioavailability to the large intestine) and the major red wine flavonols quercetin, myricetin, laricitrin and syringetin (50 μM) are capable of inhibiting the proliferation of colorectal epithelial adenocarcinoma cells. This anti-proliferative activity was partly mediated by the direct cytotoxic actions of flavonols and also their ability to cause a significant cell cycle blockage in G2/M. The anti-proliferative effects induced by flavonols were preceded, in most cases, by a strong and significant reduction of cyclooxygenase-2 (COX-2) and cyclin D1 expression. These results indicate that the observed inverse correlation between colon cancer and a moderate red wine intake may be partly mediated by the actions of red wine flavonols on the growth of cancer cells. 相似文献