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51.
A natural scorpion toxin BmK 16 was purified for the first time from the venom of the Chinese scorpion Buthus martensii Karsch (BmK) by using combined gel-filtration, ion exchange and reversed phase chromatography. The sequence of the N-terminal 8 amino acid residues was determined by Edman degradation. Using the N-terminal sequence as a tag, the database searching revealed a hit in the scorpion cDNA Bank. The sequence for N-terminal 8 amino acid residues, molecular weight and amino acid compositions of BmK 16 were identical with the calculated values according to the first 64 residues‘ se-quence of the precursor peptide alpha-neurotoxin TX16 derived from the sequence of the cDNA AF156597 (EMBL). The se-quence-specific resonance assignment of BmK 16 was achieved and the intact sequence of BmK 16 was determined as follow-ings: VRDAY IAKPH NCVYE CARNE YCNDL CTKNG AKSGY CQWVG KYGNG CWCKE LPDNV PIRVP GKCH. Furthermore, the results from the sequence homology analysis and the toxicity assays indicated that BmK 16 was an α-likescorpion neurotoxin. 相似文献
52.
中分子毒素在碳纳米管上的吸附 总被引:4,自引:0,他引:4
研究了两种不同形态的碳纳米管(随机生长多壁碳纳米管(MWCNTs)及定向生长多壁碳纳米管(ACNTs))对典型中分子毒素的吸附性能. 并与两种现有商用血液灌流吸附材料(活性炭(AC)及大孔吸附树脂(MR))进行了对比. 结果显示, 碳纳米管(CNTs)具有优异的中分子吸附能力, 其中MWCNTs对典型中分子毒素的吸附量可达47.18 mg·g-1, 为活性炭的10.8倍, 为大孔吸附树脂的5.5倍. 此外, 碳纳米管的吸附非常迅速, 中分子毒素在MWCNTs及ACNTs达到吸附平衡的时间仅为10 min和15 min, 而活性炭及大孔吸附树脂则分别需要60 min及120 min. 碳纳米管优异的吸附性能得益于其独特的微观结构所形成的发达的中孔. 因此, 碳纳米管可望成为高效的吸附材料, 应用于血液灌流中. 相似文献
53.
IntroductionSince the first report of transgenic plants ap-peared in1 984[1] ,there has been a rapid progressdirecting toward using this new technique to im-prove crops. Protecting crops from insect pestsquickly became a major goal ofgenetic engineering.By far,the greatest research effort in developingpest- resistant transgenic crops has been devoted tothe expression of Bacillus thuringiensis( Bt) toxinin plants.The formulations based on bacterium Bacillusthuringiensis as a biopesticide for … 相似文献
54.
55.
Farid Jahouh Peng Xu Willie F. Vann Pavol Kováč Joseph H. Banoub 《Journal of mass spectrometry : JMS》2013,48(10):1083-1090
We report herein the glycation sites in a vaccine candidate for cholera formed by conjugation of the synthetic hexasaccharide fragment of the O‐specific polysaccharide of Vibrio cholerae, serotype Ogawa, to the recombinant tetanus toxin C‐fragment (rTT–Hc) carrier. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analysis of the vaccine revealed that it is composed of a mixture of neoglycoconjugates with carbohydrate : protein ratios of 1.9 : 1, 3.0 : 1, 4.0 : 1, 4.9 : 1, 5.9 : 1, 6.9 : 1, 7.9 : 1 and 9.1 : 1. Liquid chromatography tandem mass spectrometry (LC‐MS/MS) analysis of the tryptic and GluC V8 digests allowed identification of 12 glycation sites in the carbohydrate–protein neoglycoconjugate vaccine. The glycation sites are located exclusively on lysine (Lys) residues and are listed as follows: Lys 22, Lys 61, Lys 145, Lys 239, Lys 278, Lys 318, Lys 331, Lys 353, Lys 378, Lys 389, Lys 396 and Lys 437. Based on the 3‐D representation of the rTT–Hc protein, all the glycation sites correspond to lysines located at the outer surface of the protein. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
56.
Javier Ramos‐Soriano Ulf Niss Dr. Jesús Angulo Dr. Manuel Angulo Dr. Antonio J. Moreno‐Vargas Dr. Ana T. Carmona Prof. Dr. Sten Ohlson Prof. Dr. Inmaculada Robina 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(52):17989-18003
The synthesis of several non‐carbohydrate ligands of cholera toxin based on polyhydroxyalkylfuroate moieties is reported. Some of them have been linked to D ‐galactose through a stable and well‐tolerated S‐glycosidic bond. They represent a novel type of non‐hydrolyzable bidentate ligand featuring galactose and polyhydroxyalkylfuroic esters as pharmacophoric residues, thus mimicking the GM1 ganglioside. The affinity of the new compounds towards cholera toxin was measured by weak affinity chromatography (WAC). The interaction of the best candidates with this toxin was also studied by saturation transfer difference NMR experiments, which allowed identification of the binding epitopes of the ligands interacting with the protein. Interestingly, the highest affinity was shown by non‐carbohydrate mimics based on a polyhydroxyalkylfuroic ester structure. 相似文献
57.
Andrew I. Selwood Alistair L. Wilkins Rex Munday Haifeng Gu Kirsty F. Smith Lesley L. Rhodes Frode Rise 《Tetrahedron letters》2014
Pinnatoxin H was isolated from a culture of the dinoflagellate Vulcanodinium rugosum isolated from the South China Sea. The structure of pinnatoxin H was elucidated by LC–MS/MS and NMR spectroscopy. It was found to have the same macrocyclic structure and substituents as pinnatoxins D, E and F, but the side chain on the cyclohexenyl ring was an ethenyl group, as found in pinnatoxin G and portimine. The observation that this strain of V. rugosum produced only pinnatoxin H and portimine is consistent with previous findings that the profile of pinnatoxins can vary significantly among strains. The acute toxicity of pinnatoxin H to mice was 67 μg/kg (intraperitoneal) and 163 μg/kg (gavage). 相似文献
58.
Arun P. Thottumkara Dr. William H. Parsons Prof. J. Du Bois 《Angewandte Chemie (International ed. in English)》2014,53(23):5760-5784
The paralytic agent (+)‐saxitoxin (STX), most commonly associated with oceanic red tides and shellfish poisoning, is a potent inhibitor of electrical conduction in cells. Its nefarious effects result from inhibition of voltage‐gated sodium channels (NaVs), the obligatory proteins responsible for the initiation and propagation of action potentials. In the annals of ion channel research, the identification and characterization of NaVs trace to the availability of STX and an allied guanidinium derivative, tetrodotoxin. The mystique of STX is expressed in both its function and form, as this uniquely compact dication boasts more heteroatoms than carbon centers. This Review highlights both the chemistry and chemical biology of this fascinating natural product, and offers a perspective as to how molecular design and synthesis may be used to explore NaV structure and function. 相似文献
59.
Design of Monodisperse and Well‐Defined Polypeptide‐Based Polyvalent Inhibitors of Anthrax Toxin 下载免费PDF全文
Sanket Patke Mohan Boggara Ronak Maheshwari Sunit K. Srivastava Manish Arha Marc Douaisi Jacob T. Martin Ian B. Harvey Matthew Brier Tania Rosen Jeremy Mogridge Prof. Ravi S. Kane 《Angewandte Chemie (International ed. in English)》2014,53(31):8037-8040
The design of polyvalent molecules, presenting multiple copies of a specific ligand, represents a promising strategy to inhibit pathogens and toxins. The ability to control independently the valency and the spacing between ligands would be valuable for elucidating structure–activity relationships and for designing potent polyvalent molecules. To that end, we designed monodisperse polypeptide‐based polyvalent inhibitors of anthrax toxin in which multiple copies of an inhibitory toxin‐binding peptide were separated by flexible peptide linkers. By tuning the valency and linker length, we designed polyvalent inhibitors that were over four orders of magnitude more potent than the corresponding monovalent ligands. This strategy for the rational design of monodisperse polyvalent molecules may not only be broadly applicable for the inhibition of toxins and pathogens, but also for controlling the nanoscale organization of cellular receptors to regulate signaling and the fate of stem cells. 相似文献
60.
National Institutes of Health Consensus Development Panel on Clinical Use of Botulinum Toxin 《Journal of voice》1992,6(4):394-400
The National Institutes of Health Consensus Development Conference on Clinical Use of Botulinum Toxin brought together neurologists, ophthalmologists, otolaryngologists, speech pathologists, and other health care professionals as well as the public to address the mechanisms of action of botulinum toxin, the indications and contraindications for botulinum toxin treatment, the general principles of technique of injection and handling for its safe and effective use, and the short-term and long-term side effects and complications of therapy. Following 2 days of presentations by experts and discussion by the audience, a consensus panel weighed the evidence and prepared their consensus statement. Among their findings, the panel recommended that (a) botulinum toxin therapy is safe and effective for treating strabismus, blepharospasm, hemifacial spasm, adductor spasmodic dysphonia, jaw-closing oromandibular dystonia, and cervical dystonia; (b) botulinum toxin is not curative in chronic neurological disorders; (c) the safety of botulinum toxin therapy during pregnancy, breast feeding, and chronic use during childhood is unknown; (d) the long-term effects of chronic treatment with botulinum toxin remain unknown; and (e) botulinum toxin should be administered by committed interdisciplinary teams of physicians and related health care professionals with appropriate instrumentation. The full text of the consensus panel's statement follows. 相似文献