全文获取类型
| 收费全文 | 114篇 |
| 免费 | 9篇 |
专业分类
| 电工技术 | 3篇 |
| 综合类 | 1篇 |
| 化学工业 | 43篇 |
| 建筑科学 | 3篇 |
| 轻工业 | 10篇 |
| 水利工程 | 1篇 |
| 无线电 | 14篇 |
| 一般工业技术 | 20篇 |
| 冶金工业 | 7篇 |
| 原子能技术 | 2篇 |
| 自动化技术 | 19篇 |
出版年
| 2024年 | 2篇 |
| 2023年 | 3篇 |
| 2022年 | 6篇 |
| 2021年 | 10篇 |
| 2020年 | 10篇 |
| 2019年 | 6篇 |
| 2018年 | 4篇 |
| 2017年 | 5篇 |
| 2016年 | 4篇 |
| 2015年 | 6篇 |
| 2014年 | 5篇 |
| 2013年 | 9篇 |
| 2012年 | 3篇 |
| 2011年 | 4篇 |
| 2010年 | 6篇 |
| 2009年 | 1篇 |
| 2008年 | 4篇 |
| 2007年 | 5篇 |
| 2006年 | 1篇 |
| 2005年 | 5篇 |
| 2004年 | 2篇 |
| 2003年 | 4篇 |
| 2002年 | 2篇 |
| 2001年 | 2篇 |
| 2000年 | 1篇 |
| 1998年 | 1篇 |
| 1997年 | 2篇 |
| 1994年 | 2篇 |
| 1993年 | 1篇 |
| 1992年 | 1篇 |
| 1990年 | 2篇 |
| 1989年 | 2篇 |
| 1988年 | 1篇 |
| 1987年 | 1篇 |
排序方式： 共有123条查询结果，搜索用时 0 毫秒
21.
Nadine Kretschmer Antje Hufner Christin Durchschein Katrin Popodi Beate Rinner Birgit Lohberger Rudolf Bauer 《International journal of molecular sciences》2021,22(5)
Melanoma is the deadliest form of skin cancer and accounts for about three quarters of all skin cancer deaths. Especially at an advanced stage, its treatment is challenging, and survival rates are very low. In previous studies, we showed that the constituents of the roots of Onosma paniculata as well as a synthetic derivative of the most active constituent showed promising results in metastatic melanoma cell lines. In the current study, we address the question whether we can generate further derivatives with optimized activity by synthesis. Therefore, we prepared 31, mainly novel shikonin derivatives and screened them in different melanoma cell lines (WM9, WM164, and MUG-Mel2 cells) using the XTT viability assay. We identified (R)-1-(1,4-dihydro-5,8-dihydroxy-1,4-dioxonaphthalen-2-yl)-4-methylpent-3-enyl 2-cyclopropyl-2-oxoacetate as a novel derivative with even higher activity. Furthermore, pharmacological investigations including the ApoToxGloTM Triplex assay, LDH assay, and cell cycle measurements revealed that this compound induced apoptosis and reduced cells in the G1 phase accompanied by an increase of cells in the G2/M phase. Moreover, it showed hardly any effects on the cell membrane integrity. However, it also exhibited cytotoxicity against non-tumorigenic cells. Nevertheless, in summary, we could show that shikonin derivatives might be promising drug leads in the treatment of melanoma. 相似文献
22.
Marcus Adam Zhiyu Wang Aliaksei Dubavik Gordon M. Stachowski Christian Meerbach Zeliha Soran‐Erdem Christin Rengers Hilmi Volkan Demir Nikolai Gaponik Alexander Eychmüller 《Advanced functional materials》2015,25(18):2638-2645
Here, a new, fast, and versatile method for the incorporation of colloidal quantum dots (QDs) into ionic matrices enabled by liquid–liquid diffusion is demonstrated. QDs bear a huge potential for numerous applications thanks to their unique chemical and physical properties. However, stability and processability are essential for their successful use in these applications. Incorporating QDs into a tight and chemically robust ionic matrix is one possible approach to increase both their stability and processability. With the proposed liquid–liquid diffusion‐assisted crystallization (LLDC), substantially accelerated ionic crystallization of the QDs is shown, reducing the crystallization time needed by one order of magnitude. This fast process allows to incorporate even the less stable colloids including initially oil‐based ligand‐exchanged QDs into salt matrices. Furthermore, in a modified two‐step approach, the seed‐mediated LLDC provides the ability to incorporate oil‐based QDs directly into ionic matrices without a prior phase transfer. Finally, making use of their processability, a proof‐of‐concept white light emitting diode with LLDC‐based mixed QD‐salt films as an excellent color‐conversion layer is demonstrated. These findings suggest that the LLDC offers a robust, adaptable, and rapid technique for obtaining high quality QD‐salts. 相似文献
23.
Anne‐Christin Bansleben Ingo Schellenberg Detlef Ulrich David Bansleben 《Flavour and Fragrance Journal》2010,25(4):214-218
Today the world market for oregano has exploded, from a once insignificant amount to a consumption volume of 500 000 tonnes/year. This is due to consumers' change in preference for Mediterranean‐style cooking and innovative cosmetic‐ and health‐related products. Since there are currently only three genotypes on the European food market, the diversity of human taste requires the breeding of new and sensorily interesting varieties. When investigating the profiles, it is necessary to establish methods suitable for characterizing the odour, taste and even retronasal odour of strong aromatic herbs. This paper is able to fulfil these requirements. In summary, these results found the tested specimens – a commonly traded blend, Origanum onites, Origanum vulgare subsp. hirtum and a blend of all three specimens – to be very dissimilar. The analysis results in a reduction in the number of relevant attributes for sensory testing and the establishment of an oregano profile with high marketing potential. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
24.
Dr. Armin Welker Dr. Christian Kersten Dr. Christin Müller Dr. Ramakanth Madhugiri Collin Zimmer Patrick Müller Robert Zimmermann Stefan Hammerschmidt Hannah Maus Prof. John Ziebuhr Prof. Christoph Sotriffer Prof. Tanja Schirmeister 《ChemMedChem》2021,16(2):340-354
Inhibition of coronavirus (CoV)-encoded papain-like cysteine proteases (PLpro) represents an attractive strategy to treat infections by these important human pathogens. Herein we report on structure-activity relationships (SAR) of the noncovalent active-site directed inhibitor (R)-5-amino-2-methyl-N-(1-(naphthalen-1-yl)ethyl) benzamide ( 2 b ), which is known to bind into the S3 and S4 pockets of the SARS-CoV PLpro. Moreover, we report the discovery of isoindolines as a new class of potent PLpro inhibitors. The studies also provide a deeper understanding of the binding modes of this inhibitor class. Importantly, the inhibitors were also confirmed to inhibit SARS-CoV-2 replication in cell culture suggesting that, due to the high structural similarities of the target proteases, inhibitors identified against SARS-CoV PLpro are valuable starting points for the development of new pan-coronaviral inhibitors. 相似文献
25.
PA Tataranni L Christin S Snitker G Paolisso E Ravussin 《Canadian Metallurgical Quarterly》1998,83(4):1260-1263
The sympathetic nervous system controls cardiovascular homeostasis and regulates energy metabolism. Pima Indians, a population with a low prevalence of hypertension and a high prevalence of obesity, have low sympathetic nervous activity, compared with Caucasians. Preliminary findings suggest that they may also have a low beta-adrenergic sensitivity. We studied beta-adrenergic sensitivity in 87 nondiabetic normotensive individuals [52 Pima Indians (35 males/17 females) and 35 Caucasians (24 males/11 females)], matched for age and body weight. Chronotropic sensitivity to beta-adrenergic stimulation was assessed by the dose of isoproterenol necessary to increase heart rate by 25 beats per minute [chronotropic dose-25 (CD25)]. Despite a similar basal heart rate and arterial blood pressure, Pimas tended to have lower beta-adrenergic sensitivity than Caucasians (CD25 = 2.37 +/- 2.27 vs. 1.57 +/- 1.38 microg, P = 0.07; mean +/- SD). This difference was significant in males (CD25 = 3.03 +/- 2.39 vs. 1.85 +/- 1.56 microg, P = 0.02) but not in females (CD25 = 1.01 +/- 1.17 vs. 0.96 +/- 0.61 microg, P = 0.99). In males only, CD25 was positively correlated to percent body fat (r = 0.36, P < 0.01). After adjustment for percent body fat, beta-adrenergic sensitivity was still significantly lower in Pima than in Caucasian males (CD25 = 3.44 +/- 2.24 vs. 2.57 +/- 1.60 microg, P = 0.05). In conclusion, our data suggest that increased adiposity is accompanied by decreased beta-adrenergic sensitivity in males only. However, at each level of adiposity, Pima Indian males have lower beta-adrenergic sensitivity than Caucasian males. In combination with a low sympathetic nervous system activity, a reduced beta-adrenergic sensitivity may contribute to the low prevalence of hypertension and the high prevalence of obesity observed in Pima Indians. 相似文献
26.
Carotenoids and chlorophylls in processed xanthophyll-rich food 总被引：1，自引：0，他引：1
Processing of food modifies nutrient contents and food matrices. The present analyses provide information about the effects of heat steam sterilization (HSS), high pressure processing (HPP) and common household cooking on the stability of carotenoids and chlorophylls in spinach, parsley, dill and kale. For HSS, samples were heated in an autoclave for 5, 10, 15 and 20 min at 121 °C. Additionally, one sample was treated via HPP at 200, 400 and 600 MPa for 5, 10 and 40 min at room temperature. Carotenoid and chlorophyll contents were determined by reversed-phase HPLC. Lutein was the most abundant carotenoid in all samples. Furthermore, violaxanthin, zeaxanthin, β-carotene, chlorophylls a and b were quantified. Thermal treatment via HSS led to a significant decline of contents of lutein, chlorophylls a and b. HPP did not reduce the amounts of xanthophylls and chlorophylls. Conclusively, HPP seems to be a good alternative to HSS for the preservation of xanthophyll-rich food. 相似文献
27.
Christin Gellrich;Leonid Shupletsov;Przemyslaw Galek;Ahmed Bahrawy;Julia Grothe;Stefan Kaskel; 《Advanced materials (Deerfield Beach, Fla.)》2024,36(29):2401336
A liquid precursor for 3D printing ultramicroporous carbons (pore width <0.7 nm) to create a novel in-plane capacitive-analog of semiconductor-based diodes (CAPodes) is presented. This proof-of-concept integrates functional EDLCs into microstructured iontronic devices. The working principle is based on selective ion-sieving, controlling the size of the electrolyte ions, and the nanoporous sieving carbon's pore size. By blocking bulky electrolyte ions from entering the sub-nanometer pores, a unidirectional charging characteristic with controllable ion flux is achieved, leading to diodic U-I characteristics with a high rectification ratio. The liquid precursor approach enables successful printing of miniaturized in-plane CAPodes. A combination of inkjet and extrusion printing techniques with suitable inks is explored to fabricate electrode materials with engineered porosity. Deliberate fine-tuning of the ultramicroporous carbon's porosity and surface area is achieved using a customized carbon precursor and CO2 etching techniques. Electrochemical evaluation of the printed CAPodes demonstrates successful miniaturization compared with macroscopic film assembly. 3D manufacturing and miniaturization allow for the integration of CAPodes into logic gate circuits (OR, AND). For the first time, these switchable devices are used as variable capacitors in a high-pass filter application, adjusting the cut-off frequency of applied alternating voltage analogous to an I-MOS varactor. 相似文献
28.
Ethik in der Medizin - 相似文献
29.
Scientometrics - Identification of important works and assessment of importance of publications in vast scientific corpora are challenging yet common tasks subjected by many research projects.... 相似文献
30.