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961.
The N-terminal fragment of prohormone brain natriuretic peptide (NT-proBNP) is a commonly used biomarker for the diagnosis of congestive heart failure, although its biological function is not well known. NT-proBNP exhibits heavy O-linked glycosylation, and it is quite difficult to develop an antibody that exhibits glycosylation-independent binding. We developed an antibody that binds to the recombinant NT-proBNP protein and its deglycosylated form with similar affinities in an enzyme immunoassay. The epitope was defined as Gly63–Lys68 based on mimetic peptide screening, site-directed mutagenesis and a competition assay with a peptide mimotope. The nearest O-glycosylation residues are Thr58 and Thr71; therefore, four amino acid residues intervene between the epitope and those residues in both directions. In conclusion, we report that an antibody reactive to Gly63–Lys68 of NT-proBNP exhibits O-glycosylation-independent binding. 相似文献
962.
Aurlien deLaTorre Yiu Yiu Lee Camille Oger Per Torp Sangild Thierry Durand Jetty Chung‐Yung Lee Jean‐Marie Galano 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(24):6363-6366
The growing importance of lipidomics, and the interest of non‐enzymatic metabolites of polyunsaturated fatty acids (PUFAs) prompted us to initiate the synthesis of novel dihomo‐IsoF compounds. Such metabolites of adrenic acid, the main PUFA in white matter, were synthesized using a divergent approach based on an orthoester cyclization. LC‐MS/MS investigation on pig brains showed the potential of this novel biomarker for the first time, as a powerful new tool for brain lipid peroxidation assessment. 相似文献
963.
964.
965.
Separation and Migration Behavior of Dichlorophenols in β‐Cyclodextrin‐Modified Capillary Zone Electrophoresis 下载免费PDF全文
Chih‐Yu Chen Yu‐Chih Liu I‐Chin Chien Chung‐Chuan Hsueh Chen‐Hsing Lin 《中国化学会会志》2014,61(9):1025-1030
The separation and migration behavior of six isomeric dichlorophenols (DCPs) in cyclodextrin‐modified capillary zone electrophoresis (CD‐CZE) using a phosphate‐borate buffer at alkaline pH with β‐CD and hydroxypropyl‐β‐CD (HP‐β‐CD) as electrolyte modifiers were investigated. The influence of buffer pH and the concentration of β‐cyclodextrins were examined. The results indicate that baseline separation of six isomeric DCPs can be achieved with addition of β‐CD concentration in the range of 2.0‐10 mM or HP‐β‐CD concentration in the range of 4.0‐10 mM at pH 10.0. Binding constants of DCPs to β‐CDs were evaluated for a better understanding of the interaction of DCPs with β‐CDs. 相似文献
966.
967.
A pH‐Responsive Carrier System that Generates NO Bubbles to Trigger Drug Release and Reverse P‐Glycoprotein‐Mediated Multidrug Resistance 下载免费PDF全文
Ming‐Fan Chung Hung‐Yi Liu Dr. Kun‐Ju Lin Dr. Wei‐Tso Chia Prof. Hsing‐Wen Sung 《Angewandte Chemie (International ed. in English)》2015,54(34):9890-9893
Multidrug resistance (MDR) resulting from the overexpression of drug transporters such as P‐glycoprotein (Pgp) increases the efflux of drugs and thereby limits the effectiveness of chemotherapy. To address this issue, this work develops an injectable hollow microsphere (HM) system that carries the anticancer agent irinotecan (CPT‐11) and a NO‐releasing donor (NONOate). Upon injection of this system into acidic tumor tissue, environmental protons infiltrate the shell of the HMs and react with their encapsulated NONOate to form NO bubbles that trigger localized drug release and serve as a Pgp‐mediated MDR reversal agent. The site‐specific drug release and the NO‐reduced Pgp‐mediated transport can cause the intracellular accumulation of the drug at a concentration that exceeds the cell‐killing threshold, eventually inducing its antitumor activity. These results reveal that this pH‐responsive HM carrier system provides a potentially effective method for treating cancers that develop MDR. 相似文献
968.
Yian-Yuan Chu Hsiu-Ming Kuo Yu-Che Wu Chin-Yi Wu Hwo-Shuenn Sheu Gene-Hsiang Lee Ming-Chou Chen Chung K. Lai 《Tetrahedron》2014
The preparation, characterization, and mesomorphic properties of two series of tridentate N-salicylidene-2-hydroxyanilines and their metal complexes were described. The crystal and molecular structure of bis[2-hydroxy-4-propyloxy-N-(2-hydroxy-3,4-dipropyloxybenzylidene) aniline]copper(II) were determined by means of X-ray analysis. It crystallizes in the monoclinic space group P2(1)/n and a Z=4. The geometry at Cu2+ ions is square pyramidal with a THF solvent molecule coordinated. The core structure was nearly flat, and the intramolecular Cu–Cu atoms were separated by ca. 3.0163(6) Å. All compounds 2a formed smectic C phases, and copper complexes 1a–Cu were not mesogenic. In contrast, compound 2e and complexes 1b–Cu, 1d–Cu, 1e–Cu, and 1e–Pd exhibited columnar phases. The lack of mesomorphism in 1e–Zn was attributed to a preferred tetrahedral over square planar geometry. A Ncell equal to 2.44–2.92, calculated from powder XRD data within a 9.0 Å thick indicated that an induced structure correlated by two catenar-shaped molecules was formed in Colh phases. 相似文献
969.
Ayyakannu Arumugam Napoleon Fazlur-Rahman Nawaz Khan Euh Duck Jeong Eun Hyuk Chung 《Tetrahedron letters》2014
An efficient, three-component domino reaction of dimedone 1, aromatic aldehydes (2a–o), and 1,3-cyclohexanedione 1a in the regio-selective synthesis of 3,3-dimethyl-9-phenyl-2H-xanthene-1,8(5H,9H)-diones (3a–o) is reported. The desired product, 3 is efficiently promoted by ascorbic acid as an organo catalyst. 相似文献
970.
The in vitro and in vivo metabolism of pyronaridine, an antimalarial agent, was investigated in rats and humans. In vitro incubation of pyronaridine with rat and human liver microsomes resulted in the formation of 11 metabolites, with pyronaridine quinoneimine (M3) as the major metabolite. The structures of pyronaridine metabolites were characterized on the basis of the product ion mass spectra obtained under low-energy collision-induced dissociation (CID) ion trap mass spectrometry. Both pyronaridine (m/z 518) and M3 (m/z 516) produced the same product ion (m/z 447). These results could be explained by the characteristic neutral loss of a 69 Da fragment from M3 via gamma-H rearrangement and 1,7 sigmatropic shift, whereas the neutral loss of a 71 Da fragment from the pyronaridine occurred by charge site-initiated heterolytic cleavage. These fragmentations were further supported by the tandem mass spectrum of D(3)-pyronaridine. Other metabolites generated in the microsomal incubations were carbonylated, hydroxylated and O-demethylated derivatives. Pyronaridine and its metabolites were detected in both feces and urine after intraperitoneal administration to rats. The in vivo metabolic profile in rats was different from the in vitro profile. M3, a chemically reactive quinonimine, was not detected whereas O-demethylated derivatives (M14, M15, M16, and M19) were identified in fecal and urinary extracts. The role of quinoneimine metabolites in pyronaridine-caused toxicity should be further evaluated, although these metabolites or their conjugates were not detected in urine and feces. 相似文献