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161.
Fluorescent carbon nanoparticles from Citrus sinensis as efficient sorbents for pollutant dyes
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Here, we report a simple, green and economic process for the synthesis of highly fluorescent carbon nanoparticles (CPs) through low‐temperature carbonization of a fruit waste, Citrus sinensis peel. This approach allows the large‐scale production of aqueous CPs dispersions without any additives and post‐treatment processes. The as‐prepared CPs were of small particle size, exhibited bright blue fluorescence under UV irradiation (λmax = 365 nm) with excellent colloidal stability in water. The chemical composition, structure and morphology of the as‐prepared CPs were analyzed using various spectroscopic techniques such as X‐ray diffraction, transmission electron microscopy and raman spectroscopy. The formed CPs were turbostratic in nature, with a large number of functional groups on the surface. We explored the adsorption characteristics of the formed CPs for wastewater treatment. Because of the negative surface of the CPs, as evident from the zeta value, it is possible to use them for selective adsorption of the cationic dye methylene blue from a mixture of dyes. The equilibrium adsorption isotherm revealed that the Langmuir model better describes the adsorption process than the Freundlich model. As‐prepared CPs rapidly adsorbed ~84% of the methylene blue within 1 min and can be regenerated and used repeatedly. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
162.
Ganguly S Paila YD Chattopadhyay A 《Biochemical and biophysical research communications》2011,(1):180-184
Sphingolipids are essential components of eukaryotic cell membranes. We recently showed that the function of the serotonin1A receptor is impaired upon metabolic depletion of sphingolipids using fumonisin B1 (FB1), a specific inhibitor of ceramide synthase. Serotonin1A receptors belong to the family of G-protein coupled receptors and are implicated in the generation and modulation of various cognitive, behavioral and developmental functions. Since function and dynamics of membrane receptors are often coupled, we monitored the lateral dynamics of the serotonin1A receptor utilizing fluorescence recovery after photobleaching (FRAP) under these conditions. Our results show an increase in mobile fraction of the receptor upon sphingolipid depletion, while the diffusion coefficient of the receptor did not exhibit any significant change. These novel results constitute the first report on the effect of sphingolipid depletion on the mobility of the serotonin1A receptor. Our results assume greater relevance in the broader context of the emerging role of receptor mobility in understanding cellular signaling. 相似文献
163.
164.
Thymol, a naturally occurring phenolic compound, has been known for its antioxidant, anti microbial, and anti inflammatory activity. Thymol has also been reported as anti-cancer agent, but its anti-cancer mechanism has not yet been fully elucidated. Thus, we aimed to investigate anticancer activity of thymol on HL-60 (acute promyelotic leukemia) cells. In our study, thymol demonstrated dose dependent cytotoxic effects on HL-60 cells after 24 h of exposure. However, thymol did not show any cytotoxic effect in normal human PBMC. The cytotoxic effect of thymol on HL-60 cells appears to be associated with induction of cell cycle arrest at sub G0/G1 phase, and apoptotic cell death based on genomic DNA fragmentation pattern. Thymol also showed significant increase in production of reactive oxygen species (ROS) activity, increase in mitochondrial H2O2 production and depolarization of mitochondrial membrane potential. On performing Western Blot analysis, thymol showed increase in Bax protein level with a concomitant decrease in Bcl2 protein expression in a dose dependent manner. Our study also showed activation of caspase -9, -8 and -3 and concomitant PARP cleavage, which is the hallmark of caspase-dependent apoptosis. Moreover, to rule out the involvement of other mechanisms in apoptosis induction by thymol, we also studied its effect on apoptosis inducing factor (AIF). Thymol induced AIF translocation from mitochondria to cytosol and to nucleus, thus indicating its ability to induce caspase independent apoptosis. We conclude that, thymol-induced apoptosis in HL-60 cells involves both caspase dependent and caspase independent pathways. 相似文献
165.
Devi YS Seibold AM Shehu A Maizels E Halperin J Le J Binart N Bao L Gibori G 《The Journal of biological chemistry》2011,286(9):7609-7618
Prolactin (PRL) is essential for normal reproduction and signals through two types of receptors, the short (PRL-RS) and long (PRL-RL) form. We have previously shown that transgenic mice expressing only PRL-RS (PRLR(-/-)RS) display abnormal follicular development and premature ovarian failure. Here, we report that MAPK, essential for normal follicular development, is critically inhibited by PRL in reproductive tissues of PRLR(-/-)RS mice. Consequently, the phosphorylation of MAPK downstream targets are also markedly inhibited by PRL without affecting immediate upstream kinases, suggesting involvement of MAPK specific phosphatase(s) in this inhibition. Similar results are obtained in a PRL-responsive ovary-derived cell line (GG-CL) that expresses only PRL-RS. However, we found the expression/activation of several known MAPK phosphatases not to be affected by PRL, suggesting a role of unidentified phosphatase(s). We detected a 27-kDa protein that binds to the intracellular domain of PRL-RS and identified it as dual specific phosphatase DUPD1. PRL does not induce expression of DUDP1 but represses its phosphorylation on Thr-155. We also show a physical association of this phosphatase with ERK1/2 and p38 MAPK. Using an in vitro phosphatase assay and overexpression studies, we established that DUPD1 is a MAPK phosphatase. Dual specific phosphatase inhibitors as well as siRNA to DUPD1, completely prevent PRL-mediated MAPK inhibition in ovarian cells. Our results strongly suggest that deactivation of MAPK by PRL/PRL-RS contributes to the severe ovarian defect in PRLR(-/-)RS mice and demonstrate the novel association of PRL-RS with DUPD1 and a role for this phosphatase in MAPK deactivation. 相似文献
166.
167.
Chitosan and its derivatives for gene delivery 总被引:2,自引:0,他引:2
Saranya N Moorthi A Saravanan S Devi MP Selvamurugan N 《International journal of biological macromolecules》2011,48(2):234-238
Gene delivery can particularly be used for the treatment of diseases by the insertion of genetic materials (DNA and RNA) into mammalian cells either to express new proteins or to prevent the expression of existing proteins. Chitosan, a natural polymer is nontoxic, biocompatible, and biodegradable and it is used as a support material for gene delivery. However, practical use of chitosan has been mainly limited to its unmodified forms, and thus modified chitosans can be used for the wide range of biomedical applications including the interaction and intracellular delivery of genetic materials. In this context, this review paper provides the recent development on chitosan derivatives available for gene delivery. 相似文献
168.
Fifty-five bacteriocinogenic lactic acid bacteria (LAB) isolated from seven different sources. Eight isolates were found to
produce pediocin PA-1 like bacteriocin as detected by pedB gene PCR and dot-blot hybridization. The culture filtrate (CF) activity of these isolates exhibited strong antilisterial,
antibacterial activity against tested food-borne pathogens and LAB. The identification and genetic diversity among the selected
LAB was performed by conventional morphological and molecular tools like RFLP, RAPD, and 16S rDNA gene sequencing. The isolates
were identified as, 1 each of Pediococcus acidilactici Cb1, Lactobacillus
plantarum Acr2, and Streptococcus equinus AC1, 2 were of P. pentosaceus Cb4 and R38, and other 3 were Enterococcus
faecium Acr4, BL1, V3. Partial characterization of the bacteriocins revealed that the peptide was heat-stable, active at acidic to
alkaline pH, inactivated by proteolytic enzymes, and had molecular weight around 4.6 kDa and shared the properties of class
IIa pediocin-family. The bacteriocin production at different temperatures, pH, and salt concentrations was studied to investigate
the optimal condition for application of these isolates as a starter culture or as a biopreservative in either acidic or non-acidic
foods. 相似文献
169.
K. Sanjana P. Devi Birendra Behera Banalata Sahoo Tapas K. Maiti 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014
Background
Newer strategies for augmenting immune responses of pharmacologically active glucans may serve to improve the medicinal potential of these biomolecules. With this aim, the present work was focused on generating targeted high molecular size glucan particles with magnified immune response activity.Methods
Heteroglucans were conjugated with PAMAM dendrimers using a Schiff base reductive amination reaction to generate a polytethered molecule with multiple glucan motifs. The modulated construct was characterized by FTIR, TEM, 1H NMR and dynamic light scattering (DLS) methods. Effects of conjugated glucans were examined in RAW 264.7 macrophage cells as well as in S-180 murine tumor models.Results
Dendrimer-conjugated glucans were found to exhibit a two-fold increase in immune stimulation in comparison to unconjugated glucans. This may be corroborated by the predominant enhancement in immunological functions such as nitric oxide production, ROS generation and immune directed tumor inhibition in murine models. Immune cell surface markers (CD4, CD8, CD19, MHC-II) and cytokine levels were also found to be highly up-regulated in the splenocytes of mice subjected to particulate glucan administration. Our study also demonstrated that conjugated glucan treatment to RAW 264.7 cells strongly enhanced the phosphorylation of two downstream signalling molecules of the mitogen activated protein kinase (MAPKs) family: p38 and MEK1/2 relative to single glucans thereby relating molecular mechanisms with enhanced immune stimulation.Conclusions and general significance
The results obtained thus support that particulate format of soluble heteroglucan will thereby improve its functionality and identify leads in therapeutic competence. 相似文献170.
K. Sri Manjari A. Jyothy P. Shravan Kumar B. Prabhakar M. Uma Devi M. Ramanna Pratibha Nallari A. Venkateshwari 《Gene》2014