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11.
Mthandazo Dube Dayma Llanes Mohamad Saoud Robert Rennert Peter Imming Ccile Hberli Jennifer Keiser Norbert Arnold 《Molecules (Basel, Switzerland)》2022,27(9)
Neglected tropical diseases affect the world’s poorest populations with soil-transmitted helminthiasis and schistosomiasis being among the most prevalent ones. Mass drug administration is currently the most important control measure, but the use of the few available drugs is giving rise to increased resistance of the parasites to the drugs. Different approaches are needed to come up with new therapeutic agents against these helminths. Fungi are a source of secondary metabolites, but most fungi remain largely uninvestigated as anthelmintics. In this report, the anthelmintic activity of Albatrellus confluens against Caenorhabditis elegans was investigated using bio-assay guided isolation. Grifolin (1) and neogrifolin (2) were identified as responsible for the anthelmintic activity. Derivatives 4–6 were synthesized to investigate the effect of varying the prenyl chain length on anthelmintic activity. The isolated compounds 1 and 2 and synthetic derivatives 4–6, as well as their educts 7–10, were tested against Schistosoma mansoni (adult and newly transformed schistosomula), Strongyloides ratti, Heligmosomoides polygyrus, Necator americanus, and Ancylostoma ceylanicum. Prenyl-2-orcinol (4) and geranylgeranyl-2-orcinol (6) showed promising activity against newly transformed schistosomula. The compounds 1, 2, 4, 5, and 6 were also screened for antiproliferative or cytotoxic activity against two human cancer lines, viz. prostate adenocarcinoma cells (PC-3) and colorectal adenocarcinoma cells (HT-29). Compound 6 was determined to be the most effective against both cell lines with IC50 values of 16.1 µM in PC-3 prostate cells and 33.7 µM in HT-29 colorectal cells. 相似文献
12.
Valentin Buchter Dr. Yih Ching Ong François Mouvet Abdallah Ladaycia Dr. Elise Lepeltier Prof. Dr. Ursula Rothlisberger Prof. Dr. Jennifer Keiser Dr. Gilles Gasser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(66):15232-15241
Schistosomiasis is a disease of poverty affecting millions of people. Praziquantel (PZQ), with its strengths and weaknesses, is the only treatment available. We previously reported findings on three lead compounds derived from oxamniquine (OXA), an old antischistosomal drug: ferrocene-containing (Fc-CH2-OXA), ruthenocene-containing (Rc-CH2-OXA) and benzene-containing (Ph-CH2-OXA) OXA derivatives. These derivatives showed excellent in vitro activity against both Schistosoma mansoni larvae and adult worms and S. haematobium adult worms, and were also active in vivo against adult S. mansoni. Encouraged by these promising results, we conducted additional in-depth preclinical studies and report in this investigation on metabolic stability studies, in vivo studies on S. haematobium and juvenile S. mansoni, computational simulations, and formulation development. Molecular dynamics simulations supported the in vitro results on the target protein. Though all three compounds were poorly stable within an acidic environment, they were only slightly cleared in the in vitro liver model. This is likely the reason why the promising in vitro activity did not translate into in vivo activity on S. haematobium. This limitation could not be overcome by the formulation of lipid nanocapsules as a way to improve the in vivo activity. Further studies should focus on increasing the compound's bioavailability, to reach an active concentration in the microenvironment of the parasite. 相似文献
13.
Ohne Zusammenfassung 相似文献
14.
Colloidal borosilicate and boron-modified colloidal silica sols were studied by 11B NMR. Formation of B–O–Si chemical bonds is established in both materials. It is shown that boron present in colloidal borosilicate is stable towards the action of complexing agents catechol and tartaric acid. In contrast, the boron in boron-modified silica is readily complexed by these agents. The results presented herein demonstrate that B–O–Si bonds are homogeneously distributed throughout the colloidal borosilicate disperse phase, while in boron-modified colloidal silica they are concentrated at the surface of colloidal silica particles. 相似文献
15.
AbstractDevising an efficient method for distributing high-radiance light-emitting diode emissions onto target surfaces is a continuing challenge. Most current design methods are mathematically complex and require intricate optimizations. In this article, a simple and highly accurate geometric optics analysis is described for creating a free-form total internal reflection collimator lens and a Fresnel exit lens, which can be fabricated easily for producing a specific intensity distribution. A powerful application is the ability to create various high-efficiency and uniform illumination patterns from a standard widely used MR16 light bulb by simply attaching a Fresnel exit lens onto the face of the bulb. 相似文献
16.
R. M. Jennerich A. N. Keiser D. A. Tate 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(1):81-89
We have obtained Doppler-free spectra of transitions in the
→ 2p2(3P)
and
→
multiplets of atomic nitrogen using saturated absorption spectroscopy. These multiplets consist of
respectively of seven and eight transitions, and have center of gravity wavelengths of 821 nm and 869 nm. Values for the hyperfine
structure coupling constants of all the upper and lower states for these multiplets were obtained for both 14N and 15N. Isotope shifts of three transitions in each multiplet were also measured, and a significant J-dependence to the shifts
was observed. 相似文献
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Hert J Keiser MJ Irwin JJ Oprea TI Shoichet BK 《Journal of chemical information and modeling》2008,48(4):755-765
The similarity of drug targets is typically measured using sequence or structural information. Here, we consider chemo-centric approaches that measure target similarity on the basis of their ligands, asking how chemoinformatics similarities differ from those derived bioinformatically, how stable the ligand networks are to changes in chemoinformatics metrics, and which network is the most reliable for prediction of pharmacology. We calculated the similarities between hundreds of drug targets and their ligands and mapped the relationship between them in a formal network. Bioinformatics networks were based on the BLAST similarity between sequences, while chemoinformatics networks were based on the ligand-set similarities calculated with either the Similarity Ensemble Approach (SEA) or a method derived from Bayesian statistics. By multiple criteria, bioinformatics and chemoinformatics networks differed substantially, and only occasionally did a high sequence similarity correspond to a high ligand-set similarity. In contrast, the chemoinformatics networks were stable to the method used to calculate the ligand-set similarities and to the chemical representation of the ligands. Also, the chemoinformatics networks were more natural and more organized, by network theory, than their bioinformatics counterparts: ligand-based networks were found to be small-world and broad-scale. 相似文献