149 research outputs found
Cloning and Characterization of Phospholipases A2 and Hyaluronidase Genes from the Venom of the Honeybee Apis mellifera carnica (Hymenoptera: Apidae)
No full textBee venom contains the allergic enzymes phospholipases A2 (PLA2) and hyaluronidase. These enzymes have been extensively studied as therapeutic modalities because of their proven effects in pharmaceutical and clinical applications. The cDNA cloning of PLA2 and hyaluronidase was amplified by RT-PCR from the total RNA of the venom gland of a honeybee (Apis mellifera carnica). The lengths of the PLA2 and hyaluronidase of Apis mellifera ligustica were 504 and 1146bp, respectively. The genes of PLA2 and hyaluronidase shared 90.94% and 96.65% homologies with A. mellifera ligustica and Apis cerana cerana, respectively. Some similar PLA2 and hyaluronidase were also found in the venom of other bee species, We analyzed their sequences and compared them with those of other sources. A notable finding was that the two genes differed from those of A. mellifera ligustica and A. cerana cerana. The positions of the disulfide bonds of PLA2 and hyaluronidase were also completely different from those previously reported. We used the available sequences to construct a phylogenetic tree and discovered that these two genes of A. mellifera carnica belonged to the western honeybee, and was more closely related to that of A. mellifera ligustica than to any other insect
A Central Consciousness at Work Beneath the Surface Artlessness: Narrative Strategies in “Tristram Shandy”
No full text‘The Life and Opinions of Tristram Shandy, Gentleman’ (hereafter shortened to “Tristram Shandy”) is a unique novel written by British author Laurence Sterne in the eighteenth century. While Sterne’s contemporary readers may have conflicting viewpoints about the artistic value of “Tristram Shandy” because of its surface artlessness and chaos, readers today in the contexts of such twentieth-century critical theories as postmodernism, existentialism, and deconstruction, find it congenial and more intriguing. I argue that despite the apparent chaos of this novel, the author-narrator Tristram is a central consciousness that holds the whole work together. And I believe Sterne narrates his story in such a peculiar way in conformity to his own perception of the outside world. Specifically, this paper aims to explore the inventive narrative strategies employed in Sterne’s “Tristram Shandy” in the three aspects of narrative structure, time-shifting technique and self-conscious narrator. Amazingly, “Tristram Shandy” presents a wholly new notion of creative writing, one that goes beyond its time, and has unbreakable connection with twentieth-century literature.</jats:p
Aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran on supported vanadium oxide catalysts: Structural effect and reaction mechanism
No full textThe structure-activity relationship and reaction mechanism for selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) in toluene were studied on vanadium oxide domains on TiO2, Al2O3, Nb2O5, ZrO2, and MgO and with a wide range of VOx surface densities. The structures of these catalysts were characterized by X-ray diffraction (XRD), diffuse reflectance UV-vis spectroscopy (UV-vis DRS), and Raman spectroscopy, and their reducibility was probed by H-2-temperature programmed reduction. The structures of the VOx domains evolved from monovanadate to polyvanadate structures with increasing the VOx surface densities, and finally to crystalline V2O5 clusters at surface densities above one-monolayer capacity. Within one-monolayer capacity, higher VOx surface densities and more reducible supports led to higher reducibility and reactivity of the VOx domains. The support surfaces covered with polyvanadates and V2O5 clusters and the supports with acidity favored the formation of DFF. The correlation between the reducibility and reactivity, together with the kinetic studies, suggests that the HMF oxidation to DFF proceeds via the redox mechanism involving the V5+/V4+ redox cycles and the reoxidation of V4+ to V5+ by O-2 as the rate-determining step. These results may provide guidance for the design of more efficient catalysts for the HMF oxidation to synthesize DFF.Chemistry, MultidisciplinarySCI(E)18ARTICLE3765-7778
Pre-activation with TLR7 in combination with thioridazine and loratadine promotes tumoricidal T-cell activity in colorectal cancer
No full textResearch progress in neuropathic pain after spinal cord injury: a bibliometric study from 2013 to 2024
No full textBackgroundThe incidence of neuropathic pain (NP) after spinal cord injury (SCI) is quite high. This pain is clinically challenging to treat and has an debilitating effect on patients. In recent years, NP is a popular topic of research and a number of relevant articles have been published in academic journals. The purpose of this article is to analyze the global research trend of NP after SCI using bibliometric methods.MethodsThe literature was screened from 2013 to 2024 based on the Web of Science core collection (WOSCC). These publications, including annual publications, journals, authors, references, and keywords via CiteSpace, were analyzed in order to help understand the current research direction and hotspots in this field.ResultsA total of 2022 publications were included in the analysis. The results showed that an overall upward trend in the number of publications in the study period. The top five productive journals are Spinal Cord, Journal of Neurotrauma, Pain, Experimental Neurology, and Journal of Spinal Cord Medicine, the journals related to spinal cord or pain. The top five most productive scholars are Armin Curt, Michael G. Fehlings, Wu Junfang, John L. K. Kramer, and Farinaz Nasirinezhad. Keyword bursts showed that signaling pathway, neuroinflammation, neuralgia, spinal cord stimulation, inhibition, and depression have become new research hotspots in the field of NP after SCI.ConclusionThis study provides a basis for the study of pain after SCI. It summarizes past research on NP following SCI and offers valuable reference data for further exploration of research trends and issues of focus in this field
Efficient aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran on manganese oxide catalysts
No full textA cryptomelane-type manganese oxide octahedral molecular sieve with a (2 x 2, 4.6 angstrom x 4.6 angstrom) tunnel size (OMS-2) efficiently catalyzed aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) with a high yield of 97.2% at 383 K and 0.5 MPa O-2 in N,N-dimethylformamide. OMS-2 was superior to other MnO2 catalysts with different morphologies, including OMS-1, OMS-6, and OMS-7 with various tunnel sizes, amorphous MnO2 and bimessite-type MnO2, apparently due to its (2 x 2) tunnel structure and consequently high reducibility and oxidizability. Kinetic and isotopic studies on OMS-2 showed near half-order dependence of the activities on HMF and O-2 concentrations and marked kinetic isotope effects for deuterated HMF at its methylene group. These results, together with the similar initial rates under aerobic and anaerobic conditions, suggest that HMF oxidation to DFF on OMS-2 proceeds via a redox mechanism involving kinetically-relevant steps of C-H bond cleavage in adsorbed alcoholate intermediate, derived from quasi-equilibrated dissociation of HMF, using lattice oxygen and reoxidation of Mn3+ to Mn4+ by dissociative chemisorption of O-2. (C) 2014 Elsevier Inc. All rights reserved.Chemistry, PhysicalEngineering, ChemicalSCI(E)[email protected]
Gender differences in the bile acid profiles of APP/PS1 transgenic AD mice
No full textAlzheimer's disease (AD) is a neurodegenerative disease and presents in the accumulation of amyloid and neurofibrillary tangle. The association between modulations of gut symbiotic microbes with neurological disease via bidirectional gut-brain axis has been well documented. Bile acid (BA) pools in the enterohepatic circulation could be valuable for probing complex biochemical interactions between host and their symbiotic microbiota. Herein we investigated the levels of 28 BAs in several compartments in enterohepatic circulation (including jejunal, ileum, cecum, colon and feces, plasma and liver tissue) by employing an APP/PS1 induced transgenic AD mouse model. We found that BA profiles in AD mice were gender specific. We observed decreased levels of taurine-conjugated primary BAs (TUDCA, TCA, T-α-MCA and T-β-MCA) and increased levels of secondary BA (iso-DCA) in plasma and liver extracts for female AD transgenic mice. In contrast, increased levels of TDCA in liver extracts and decreased levels of T-β-MCA in jejunal content were noted in male AD mice. These observations suggested that perturbations of BA profiles in AD mice displayed clear gender variations. Our study highlighted the roles of gut microbiota on neurodegenerative disease, which could be gender specific.Accepted versio
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