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121.
Isolation,Structure Elucidation,and (Bio)Synthesis of Haprolid,a Cell‐Type‐Specific Myxobacterial Cytotoxin 下载免费PDF全文
Heinrich Steinmetz Dr. Jun Li Dr. Chengzhang Fu Dr. Nestor Zaburannyi Dr. Birgitte Kunze Dr. Kirsten Harmrolfs Viktoria Schmitt Dr. Jennifer Herrmann Prof. Dr. Hans Reichenbach Prof. Dr. Gerhard Höfle Prof. Dr. Markus Kalesse Prof. Dr. Rolf Müller 《Angewandte Chemie (International ed. in English)》2016,55(34):10113-10117
Myxobacteria are well‐established sources for novel natural products exhibiting intriguing bioactivities. We here report on haprolid ( 1 ) isolated from Byssovorax cruenta Har1. The compound exhibits an unprecedented macrolactone comprising four modified amino acids and a polyketide fragment. As configurational assignment proved difficult, a bioinformatic analysis of the biosynthetic gene cluster was chosen to predict the configuration of each stereocenter. In‐depth analysis of the corresponding biosynthetic proteins established a hybrid polyketide synthase/nonribosomal peptide synthetase origin of haprolid and allowed for stereochemical assignments. A subsequent total synthesis yielded haprolid and corroborated all predictions made. Intriguingly, haprolid showed cytotoxicity against several cell lines in the nanomolar range whereas other cells were almost unaffected by treatment with the compound. 相似文献
122.
123.
Oier Aizpurua-Olaizola Jone Omar Patricia Navarro Maitane Olivares Nestor Etxebarria Aresatz Usobiaga 《Analytical and bioanalytical chemistry》2014,406(29):7549-7560
High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) has been successfully applied to cannabis plant extracts in order to identify cannabinoid compounds after their quantitative isolation by means of supercritical fluid extraction (SFE). MS conditions were optimized by means of a central composite design (CCD) approach, and the analysis method was fully validated. Six major cannabinoids [tetrahydrocannabinolic acid (THCA), tetrahydrocannabinol (THC), cannabidiol (CBD), tetrahydrocannabivarin (THCV), cannabigerol (CBG), and cannabinol (CBN)] were quantified (RSD < 10%), and seven more cannabinoids were identified and verified by means of a liquid chromatograph coupled to a quadrupole-time-of-flight (Q-ToF) detector. Finally, based on the distribution of the analyzed cannabinoids in 30 Cannabis sativa L. plant varieties and the principal component analysis (PCA) of the resulting data, a clear difference was observed between outdoor and indoor grown plants, which was attributed to a higher concentration of THC, CBN, and CBD in outdoor grown plants. Graphical Abstract
Representative figure of the identification and quantification process of cannabinoids 相似文献
124.
Débora Bellini Machado Ivone M. Sato Flávia R. O. Silva Vera Lúcia R. Salvador Júlio Takehiro Marumo Nestor Schor Maria Helena Bellini 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(1):97-102
Following physical examination and radiography analysis, cystotomy was performed to remove a rabbit’s single bladder stone. This rabbit urolith was analyzed by X-ray fluorescence spectrometry (EDXRF) and scanning electron microscopy (SEM). The EDXRF technique was successful for the determination of major elements (Ca, Mg, P, K and S) and presented sufficient sensitivity to also trace elements (Sr, Fe, Cu, V, Cr, Mn, Zn and Pb) determination. The results showed significant quantitative and structural variations among the urolith regions. The EDXRF technique using the fundamental parameters method and SEM attend as complementary techniques that can be useful in the management of urinary stone analysis. 相似文献
125.
Flávia Gomes de Góes Rocha Karen Cristina Barbosa Chaves Cinthia Zanini Gomes Camila Barricheli Campanharo Lilia Coronato Courrol Nestor Schor Maria Helena Bellini 《Journal of fluorescence》2010,20(6):1225-1231
Renal cell carcinoma (RCC) remains one of the greatest challenges of urological oncology and is the third leading cause of
death in genitourinary cancers. RCCs are highly vascularized and are amenable to antiangiogenic therapy. Endostatin (ES) is
a fragment of collagen XVIII that possesses antiangiogenic activity. In this study, we examined the potential of erythrocyte
PpIX fluorescence spectroscopy for monitoring the efficacy of antiangiogenic therapy in metastatic renal cell carcinoma (mRCC),
using an orthotopic metastatic mouse model. Balb/C-bearing Renca cells were treated with NIH/3T3-LendSN cells. Lung weight,
nodule area, microvascular area (MVA), and erythrocyte PpIX fluorescence were evaluated. Emission spectra were obtained by
exciting the samples at 405 nm. There was a significant decrease in lung wet weight, lung nodule area and MVA in the treated
group compared to the control group (P < 0.001). Significant differences in autofluorescence shape were observed in the 620–650 nm spectral region. The most intense
fluorescence peak was observed at ∼632 nm. The autofluorescence of the control samples was about 53% higher than that of normal
blood (P < 0.05). In the group treated with ES, the autofluorescence was about 54% lower than in the control group (P < 0.05). Fluorescence intensity was positively correlated with the nodule area (R
2 = 0.8859; P < 0.001) and MVA (R
2 = 0.9431; P < 0.001) in the ES-treated group. These results demonstrate that the spectroscopic analysis method allows a selective detection
of tumor masses. This preliminary study suggests that PpIX fluorescence may be useful as a biomarker for antiangiogenic cancer
therapy. 相似文献
126.
Olivares M Vallejo A Irazola M Murelaga X Baceta JI Tarriño A Etxebarria N 《Talanta》2010,83(2):605-612
The analysis of hydrocarbons in chert rocks provides a worthwhile source of information regarding the geochemical features of a depositional setting. Since the typical analytical procedure requires long Soxhlet extractions and the use of large quantities of sample (30-50 g), in this work we have optimised the focused ultrasound extraction (FUSE) and the microwave-assisted extraction (MAE) to make available a less severe procedure. In both cases a full experimental design including solvent mixture composition (Dichloromethane/Hexane/Acetone) and process variables (sonication time and cycles, and extraction temperature and time) by means of D-optimal designs. In the extracted fractions hydrocarbons (C16-C40) were analysed by gas-chromatography-mass spectrometry. In the case of FUSE the process variables were the most sensitive variables and the optimum conditions were defined at 60:40 DCM/Hex mixture and a sonication time of 30 min and 9 cycles. In the case of MAE all the variables shown a significant effect on the extraction yield and the most adequate conditions (60:30:10 DCM/Hex/Ace mixture and an irradiation time of 15 min at 110 °C) were established from the analysis of the response surface. Both methods were systematically applied with different chert samples collected in Cucho (Trebiño County, Burgos, Spain) and we were able to assure quantitative extractions (>85%) in the first extraction. Additionally, from the distribution patterns of n-alkanes obtained in the different chert samples (nodular chert, laminar chert and massive-brechoid chert) collected in Cucho, we were able to distinguish different origins and diagenetic history. 相似文献
127.
Ruiz-Hernandez SE Grau-Crespo R Almora-Barrios N Wolthers M Ruiz-Salvador AR Fernandez N de Leeuw NH 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):9828-9833
We have calculated the concentrations of Mg in the bulk and surfaces of aragonite CaCO(3) in equilibrium with aqueous solution, based on molecular dynamics simulations and grand-canonical statistical mechanics. Mg is incorporated in the surfaces, in particular in the (001) terraces, rather than in the bulk of aragonite particles. However, the total Mg content in the bulk and surface of aragonite particles was found to be too small to account for the measured Mg/Ca ratios in corals. We therefore argue that most Mg in corals is either highly metastable in the aragonite lattice, or is located outside the aragonite phase of the coral skeleton, and we discuss the implications of this finding for Mg/Ca paleothermometry. 相似文献
128.
Bassolé IH Lamien-Meda A Bayala B Tirogo S Franz C Novak J Nebié RC Dicko MH 《Molecules (Basel, Switzerland)》2010,15(11):7825-7839
Essential oils from leaves of Lippia multiflora, Mentha x piperita and Ocimum basilicum from Burkina Faso were analysed by GC-FID and GC-MS. Major components were p-cymene, thymol, b-caryophyllene, carvacrol and carvone for L. multiflora, menthol and iso-menthone for M. x piperita and, linalool and eugenol for O. basilicum. The essential oils and their major monoterpene alcohols were tested against nine bacterial strains using the disc diffusion and broth microdilution methods. The essential oils with high phenolic contents were the most effective antimicrobials. The checkerboard method was used to quantify the efficacy of paired combinations of essential oils and their major components. The best synergetic effects among essential oils and major components were obtained with combinations involving O. basilicum essential oil and eugenol, respectively. As phenolic components are characterized by a strong spicy aroma, this study suggests that the selection of certain combinations of EOs could help to reduce the amount of essential oils and consequently reduce any adverse sensory impact in food. 相似文献
129.
We demonstrate in this Letter that a joint transform correlator shows vulnerability to known-plaintext attacks. An unauthorized user, who intercepts both an object and its encrypted version, can obtain the security key code mask. In this contribution, we conduct a hybrid heuristic attack scheme merge to a Gerchberg-Saxton routine to estimate the encrypting key to decode different ciphertexts encrypted with that same key. We also analyze the success of this attack for different pairs of plaintext-ciphertext used to get the encrypting code. We present simulation results for the decrypting procedure to demonstrate the validity of our analysis. 相似文献
130.
Jone Omar Alfredo Sarmiento Maitane Olivares Ibone Alonso Nestor Etxebarria 《Journal of Raman spectroscopy : JRS》2012,43(8):1151-1156
In this work, virgin olive oil mixed with essential oils from rosemary has been analyzed by means of Raman spectroscopy. First of all, experimental design has been employed in order to define the Raman spectroscopy's parameters, final measuring conditions were: acquisition time of 30 s, five accumulations, and the intensity of the laser power at 75 mW. The Raman spectra were initially measured at full range (150–3000 cm−1), but a narrower window assured faster accumulations and more accurate predictions. The calibration solutions of eucalyptol and camphor in olive oil were prepared following a central composite design and different spectra pre‐processing algorithms were evaluated. To conclude, essential oils obtained by means of Supercritical Fluid Extraction, Ultrasounds, and hydrodistillation were mixed with virgin olive oil and quantified with Raman spectroscopy. Predicted concentrations of the olive oil mixtures were compared with concentrations obtained for the same samples by a Comprehensive Two‐Dimensional Gas Chromatographic (GC × GC) method. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献