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131.
Ramovatar Meena Kavindra Kumar Kesari Madhu Rani R. Paulraj 《Journal of nanoparticle research》2012,14(2):712
The study aimed to correlate cell proliferation inhibition with oxidative stress and p53 protein expression in cancerous cells.
Hydroxyapatite (HAP) (Ca10(PO4)6(OH)2) is the essential component of inorganic composition in human bone. It has been found to have obvious inhibitory function
on growth of many kinds of tumor cells and its nanoparticle has stronger anti-cancerous effect than macromolecule microparticles.
Human breast cancer cells (MCF-7) were cultured and treated with HAP nanoparticles at various concentrations. Cells viability
was detected with MTT colorimetric assay. The morphology of the cancerous cells was performed by transmission electron microscopy
and the expression of a cell apoptosis related gene (p53) was determined by ELISA assay and flow cytometry (FCM). The intracellular
reactive oxygen species (ROS) level in HAP exposed cells was measured by H2DCFDA staining. DNA damage was measured by single-cell gel electrophoresis assay. The statistical analysis was done by one
way ANOVA. The cellular proliferation inhibition rate was significantly (p < 0.05) increasing in a dose-dependent manner of HAP nanoparticles. Cell apoptotic characters were observed after MCF-7 cells
were treated by HAP nanoparticles for 48 h. Moreover, ELISA assay and FCM shows a dose-dependent activation of p53 in MCF-7
cells treated with nanoHAP. These causative factors of the above results may be justified by an overproduction of ROS. In
this study, a significant (p < 0.05) increase in the level of intracellular ROS in HAP-treated cells was observed. This study shows that HAP inhibits
the growth of human breast cancer MCF-7 cells as well as induces cell apoptosis. This study shows that HAP NPs Induce the
production of intracellular reactive oxygen species and activate p53, which may be responsible for DNA damage and cell apoptosis. 相似文献
132.
Bansal S Ponnan P Raj HG Weintraub ST Chopra M Kumari R Saluja D Kumar A Tyagi TK Singh P Prasad AK Saso L Rastogi RC Parmar VS 《Applied biochemistry and biotechnology》2009,157(2):285-298
Our earlier reports documented that calreticulin, a multifunctional Ca2+-binding protein in endoplasmic reticulum lumen, possessed protein acetyltransferase function termed Calreticulin Transacetylase
(CRTAase). The autoacetylation of purified human placental CRTAase concomitant with the acetylation of receptor proteins by
a model acetoxycoumarin, 7,8-Diacetoxy-4-methylcoumarin, was observed. Here, we have examined the autoacetylation property
of CRTAase by immunoblotting and mass spectrometry. Ca2+ was found to inhibit CRTAase activity. The inhibition of both autoacetylation of CRTAase as well as acetylation of the receptor
protein was apparent when Ca2+ was included in the reaction mixture as visualized by interaction with anti-acetyl lysine antibody. The acetylation of lysines
residues: −48, −62, −64, −153, and −159 in N-domain and −206, −207, −209, and −238 in P-domain of CRTAase were located by
high-performance liquid chromatography-electronspray ionization tandem mass spectrometry. Further, computer assisted protein
structure modeling studies were undertaken to probe the effect of autoacetylation of CRTAase. Accordingly, the predicted CRTAase
3D model showed that all the loop regions of both N- and P-domain bear the acetylated lysines. Energy minimization of the
acetylated residues revealed charge neutralization of lysines due to the N-ε-acetylation which may facilitate the interaction
of CRTAase with the protein substrate and the subsequent transacetylase action.
An erratum to this article can be found at 相似文献
133.
Yao Liu Madhu Sheri Marcus D. Cole Duk Man Yu Todd Emrick Thomas P. Russell 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5733-5737
A new and highly efficient cathode interlayer material for organic photovoltaics (OPVs) was produced by integrating C60 fullerene monomers into ionene polymers. The power of these novel “C60‐ionenes” for interface modification enables the use of numerous high work‐function metals (e.g., silver, copper, and gold) as the cathode in efficient OPV devices. C60‐ionene boosted power conversion efficiencies (PCEs) of solar cells, fabricated with silver cathodes, from 2.79 % to 10.51 % for devices with a fullerene acceptor in the active layer, and from 3.89 % to 11.04 % for devices with a non‐fullerene acceptor in the active layer, demonstrating the versatility of this interfacial layer. The introduction of fullerene moieties dramatically improved the conductivity of ionene polymers, affording devices with high efficiency by reducing charge accumulation at the cathode/active layer interface. The power of C60‐ionene to improve electron injection and extraction between metal electrodes and organic semiconductors highlights its promise to overcome energy barriers at the hard‐soft materials interface to the benefit of organic electronics. 相似文献
134.
Inside Back Cover: A Detailed Analysis of the Morphology of Fibrils of Selectively Mutated Amyloid β (1–40) (ChemPhysChem 17/2016)
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135.
Sonyanaik B. Sakram B. Shyam P. Madhu P. Govan M. 《Russian Journal of General Chemistry》2018,88(7):1495-1501
Russian Journal of General Chemistry - An efficient synthesis of 6-(2-chloro-4-fluorophenyl)-9-phenylimidazo[1,2-a][1,8]naphthyridine derivatives by the reaction of phenacyl bromide with... 相似文献
136.
Pharmacophore hypotheses were developed for six structurally diverse series of cholecystokinin-B/gastrin receptor (CCK-BR) antagonists. A training set consisting of 33 compounds was carefully selected. The activity spread of the training set molecules was from 0.1 to 2100 nM. The most predictive pharmacophore model (hypothesis 1), consisting of four features, namely, two hydrogen bond donors, one hydrophobic aliphatic, and one hydrophobic aromatic feature, had a correlation (r) of 0.884 and a root-mean-square deviation of 1.1526, and the cost difference between null cost and fixed cost was 81.5 bits. The model was validated on a test set consisting of six different series of 27 structurally diverse compounds and performed well in classifying active and inactive molecules correctly. This validation approach provides confidence in the utility of the predictive pharmacophore model developed in this work as a 3D query tool in the virtual screening of drug-like molecules to retrieve new chemical entities as potent CCK-BR antagonists. The model can also be used to predict the biological activities of compounds prior to their costly and time-consuming synthesis. 相似文献
137.
Hydrated and anhydrous trinuclear metal(III) trifluoroacetates of Cr and Fe were prepared by reaction of freshly precipitated metal oxides with trifluoroacetic acid, while manganese analogs by acid exchange. IR data show the presence of bidentate trifluoroacetate groups. The diffuse reflectance spectra suggest octahedral environment around metals.Mössbauer spectra show that iron atoms in the compounds are high spin hexacoordinated; two types of iron sites are suggested in hydrated iron compound. Low magnetic moment of chromium and iron compounds indicate antiferromagnetic coupling. Th anhydrous compounds decompose in single step with the evolution of (CF3CO)2O.M
3O(O2CCF3)7 form complexes [M
3O(O2CCF3)6·3Py]+ [O2CCF3]– with pyridine.
Dreikernige Metall(III)-Trifluoracetate
Zusammenfassung Es wurden hydratisierte und wasserfreie dreikernige Metall(III)-Trifluoracetate von Cr und Fe mittels der Reaktion von frisch gefälltem Metalloxid und Trifluoressigsäure dargestellt; die Mangan-Analogen wurden über Säure-Austausch gewonnen. Die IR-Daten zeigen die Präsenz von zweizähnigen Trifluoracetat-Gruppen an. Die diffuse-reflectance-Spektren sprechen für eine octahedrale Umgebung rund um das Metall. DieMössbauer-Spektren zeigen, daß die Eisenatome in den entsprechenden Verbindungen high-spin hexakoordiniert sind; dabei werden in den hydratisierten Eisenverbindungen zwei Typen von Eisenatomen gezeigt. Ein niederes magnetisches Moment der Chrom- und Eisen-Verbindungen zeigen eine antiferromagnetische Kopplung an. Die wasserfreien Verbindungen zersetzen sich in einem einzigen Schritt unter Entwicklung von (CF3CO)2O. Mit Pyridin bilden die VerbindungenM 3O(O2CCF3)7 die Komplexe [M 3O(O2CCF3)6·3Py]+ [O2CCF3]–.相似文献
138.
Dr. Juliane Adler Monika Baumann Bruno Voigt Dr. Holger A. Scheidt Dr. Debanjan Bhowmik Dr. Tilmann Häupl Prof. Dr. Bernd Abel Prof. Dr. Perunthiruthy K. Madhu Prof. Dr. Jochen Balbach Prof. Dr. Sudipta Maiti Prof. Dr. Daniel Huster 《Chemphyschem》2016,17(17):2744-2753
A small library of rationally designed amyloid β [Aβ(1–40)] peptide variants is generated, and the morphology of their fibrils is studied. In these molecules, the structurally important hydrophobic contact between phenylalanine 19 (F19) and leucine 34 (L34) is systematically mutated to introduce defined physical forces to act as specific internal constraints on amyloid formation. This Aβ(1–40) peptide library is used to study the fibril morphology of these variants by employing a comprehensive set of biophysical techniques including solution and solid‐state NMR spectroscopy, AFM, fluorescence correlation spectroscopy, and XRD. Overall, the findings demonstrate that the introduction of significant local physical perturbations of a crucial early folding contact of Aβ(1–40) only results in minor alterations of the fibrillar morphology. The thermodynamically stable structure of mature Aβ fibrils proves to be relatively robust against the introduction of significantly altered molecular interaction patterns due to point mutations. This underlines that amyloid fibril formation is a highly generic process in protein misfolding that results in the formation of the thermodynamically most stable cross‐β structure. 相似文献
139.
Madhu Sudan Manna Seok Yeol Yoo Mohammed Sharique Hyoju Choi Bimal Pudasaini Prof. Dr. Mu-Hyun Baik Prof. Dr. Uttam K. Tambar 《Angewandte Chemie (International ed. in English)》2023,62(35):e202304848
We report a copper-catalyzed, regioselective, and stereospecific alkylation of unbiased internal allylic carbonates with functionalized alkyl and aryl Grignard reagents. The reactions exhibit high stereospecificity and regioselectivity for either SN2 or SN2′ products under two sets of copper-catalyzed conditions, which enables the preparation of a broad range of products with E-alkene selectivity. Density functional theory calculations reveal the origins of the regioselectivity based on the different behaviors of homo- and heterocuprates. 相似文献
140.
Sharma N Sharma UK Malik S Bhushan S Kumar V Verma SC Sharma N Sharma M Sinha AK 《Journal of separation science》2008,31(4):629-635
Shikonin and its derivatives are important red colored naphthoquinone pigments found in a large number of Arnebia species, including A. euchroma, that are responsible for the various pharmacological activities exhibited by the plant. The precise separation of each naphthoquinone is essential for total quality evaluation and bioactivity analysis of herbal formulations of A. euchroma. Furthermore, the overexploitation of this useful plant has resulted in species becoming endangered. With this in mind, a simple and rapid preparative scale HPLC method with single compound recovery for the isolation and purification of two shikonin derivatives (i. e. acetylshikonin, beta-acetoxyisovalerylshikonin) from cell suspension cultures of A. euchroma is presented. The compounds were separated on a C(18) column within 10 min using acetonitrile/methanol (95:5) as mobile phase in isocratic mode. The isolated compounds were found to be more than 98% pure. The LOD for acetylshikonin and beta-acetoxyisovalerylshikonin was estimated at 0.063 and 0.146 mug/mL, respectively, while the LOQ was found to be 0.209 and 0.487 mug/mL, respectively. The recoveries accomplished for both the shikonin derivatives were in the range of 94.7-96.8%. The repeatability, expressed as %RSD, of acetylshikonin and beta-acetoxyisovalerylshikonin was found to be 1.74 and 1.27, respectively. 相似文献