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371.
Dual Role of the 1,2,3‐Triazolium Ring as a Hydrogen‐Bond Donor and Anion–π Receptor in Anion‐Recognition Processes
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Dr. Fabiola Zapata Lidia Gonzalez Dr. Antonio Caballero Prof. Ibón Alkorta Prof. Jose Elguero Prof. Pedro Molina 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9797-9808
Several bis(triazolium)‐based receptors have been synthesized as chemosensors for anion recognition. The central naphthalene core features two aryltriazolium side‐arms. NMR experiments revealed differences between the binding modes of the two triazolium rings: one triazolium ring acts as a hydrogen‐bond donor, the other as an anion–π receptor. Receptors 92+?2BF4 ? (C6H5), 112+?2BF4 ? (4‐NO2?C6H4), and 132+?2BF4? (ferrocenyl) bind HP2O73? anions in a mixed‐binding mode that features a combination of hydrogen‐bonding and anion–π interactions and results in strong binding. On the other hand, receptor 102+?2 BF4 ? (4‐CH3O?C6H4) only displays combined Csp2?H/anion–π interactions between the two arms of the receptors and the bound anion rather than triazolium (CH)+???anion hydrogen bonding. All receptors undergo a downfield shift of the triazolium protons, as well as the inner naphthalene protons, in the presence of H2PO4? anions. That suggests that only hydrogen‐bonding interactions exist between the binding site and the bound anion, and involve a combination of cationic (triazolium) and neutral (naphthalene) C?H donor interactions. Theoretical calculations relate the electronic structure of the substituent on the aromatic group with the interaction energies and provide a minimum‐energy conformation for all the complexes that explains their measured properties. 相似文献
372.
373.
Chemoproteomic Approach to Explore the Target Profile of GPCR ligands: Application to 5‐HT1A and 5‐HT6 Receptors
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Dr. Ainoa Rueda‐Zubiaurre Dr. Dulce Alonso Dr. Henar Vázquez‐Villa Dr. Lidia Martín‐Couce Dr. Óscar Palomares Dr. Juan A. López Prof. Dr. Mar Martín‐Fontecha Prof. Dr. Bellinda Benhamú Prof. Dr. María L. López‐Rodríguez Prof. Dr. Silvia Ortega‐Gutiérrez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(4):1313-1321
Determination of the targets of a compound remains an essential aspect in drug discovery. A complete understanding of all binding interactions is critical to recognize in advance both therapeutic effects and undesired consequences. However, the complete polypharmacology of many drugs currently in clinical development is still unknown, especially in the case of G protein‐coupled receptor (GPCR) ligands. In this work we have developed a chemoproteomic platform based on the use of chemical probes to explore the target profile of a compound in biological systems. As proof of concept, this methodology has been applied to selected ligands of the therapeutically relevant serotonin 5‐HT1A and 5‐HT6 receptors, and we have identified and validated some of their off‐targets. This approach could be extended to other drugs of interest to study the targeted proteome in disease‐relevant systems. 相似文献
374.
Anna Przybylska-Balcerek Tomasz Szablewski Lidia Szwajkowska-Michaek Dariusz
wierk Renata Cegielska-Radziejewska Zbigniew Krejpcio Elbieta Suchowilska ukasz Tomczyk Kinga Stuper-Szablewska 《Molecules (Basel, Switzerland)》2021,26(10)
Due to the health-promoting properties of elderberry fruits, which result from their rich chemical composition, this raw material is widely used in herbal medicine and the food industry. The aim of the study was to demonstrate the antibacterial activity of the elderberry fruit extracts. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The following phenolic acids were predominant: chlorogenic acid, sinapic acid, and t-cinnamic acid. Their average content was, respectively, 139.09, 72.84, 51.29 mg/g extract. Rutin and quercetin (their average content was 1105.39 and 306.6 mg/g extract, respectively) were the dominant flavonoids. The research showed that the elderberry polyphenol extracts exhibited activity against selected strains of bacteria within the concentration range of 0.5–0.05%. The following bacteria were the most sensitive to the extracts: Micrococcus luteus, Proteus mirabilis, Pseudomonas fragii, and Escherichia coli. Of the compounds under analysis, apigenin, kaempferol and ferulic, protocatechuic, and p-coumarin acids had the greatest influence on the high antibacterial activity of elderberry extracts. The results of the microbiological and chemical analyses of the composition of the extracts were analyzed statistically to indicate the bioactive compounds of the greatest antimicrobial significance. 相似文献
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Lidia Leporini Luigi Menghini Marzia Foddai Giacomo Luigi Petretto Mario Chessa Bruno Tirillini 《Natural product research》2015,29(10):899-907
Ethanol extracts of Stachys glutinosa L. (Lamiaceae) were investigated for antioxidative properties, as well as antiproliferative action on various cell lines. The antioxidant activities were investigated by ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulphonic acid) assay, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, β-carotene/linoleic acid assay, scavenging of hydrogen peroxide (horseradish peroxidase test), superoxide anion scavenging, and hypochlorous acid scavenging (taurine test). The antioxidant activity was reported as IC50 and reveals antioxidant effects. Antiproliferative effects were measured in vitro on three cell lines: HepG2 (human hepatocarcinoma), MCF7 (breast human adenocarcinoma) and C2C12 (mouse myoblast) cell lines by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The ethanol extract induced variations in cell viability on all cell lines tested. At 200 μg/mL, the effects on cell viability were ? 23%, ? 27% and ? 37%, respectively, for C2C12, MCF7 and HepG2. 相似文献
379.
Frontispiece: Cage‐like Copper(II) Silsesquioxanes: Transmetalation Reactions and Structural,Quantum Chemical,and Catalytic Studies
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Dr. Alexey N. Bilyachenko Dr. Marina S. Dronova Alexey I. Yalymov Dr. Frédéric Lamaty Dr. Xavier Bantreil Prof. Jean Martinez Christelle Bizet Lidia S. Shul'pina Prof. Alexander A. Korlyukov Dmitry E. Arkhipov Dr. Mikhail M. Levitsky Prof. Elena S. Shubina Dr. Alexander M. Kirillov Prof. Georgiy B. Shul'pin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(24)
380.
Vanessa A. dos Santos Lidia S. Shul''pina Dario Veghini Dalmo Mandelli Georgiy B. Shul''pin 《Reaction Kinetics and Catalysis Letters》2006,88(2):339-348
Summary The dinuclear manganese(IV) complex [LMn(O)3MnL](PF6)2 (1, L = 1,4,7-trimethyl-1,4,7-triazacyclononane) catalyzes the extremely efficient oxidation of alcohols with hydrogen peroxide
at room temperature. Oxalic acid is an obligatory co-catalyst. The oxidation of isopropanol, for example, yields acetone with
turnover numbers up to 40000 after 5-10 h in the absence of a solvent. 2-Cyanoethanol was oxidized by this system with somewhat
lower efficiency (conversion 70%). The catalytically active cation from salt 1 was obtained in an insoluble form containing
a heteropoly anion [Mn2O3(TMTACN)2]2[SiW12O40]. Oxidation of 2-cyanoethanol using this heterogenized catalyst and oxalic acid gave the oxo-products with the 54% total
yield. 相似文献