28 research outputs found
Static and dynamic resting-state brain activity patterns of table tennis players in 7-Tesla MRI
Table tennis involves quick and accurate motor responses during training and competition. Multiple studies have reported considerably faster visuomotor responses and expertise-related intrinsic brain activity changes among table tennis players compared with matched controls. However, the underlying neural mechanisms remain unclear. Herein, we performed static and dynamic resting-state functional magnetic resonance imaging (rs-fMRI) analyses of 20 table tennis players and 21 control subjects using 7T ultra-high field imaging. We calculated the static and dynamic amplitude of low-frequency fluctuations (ALFF) of the two groups. The results revealed that table tennis players exhibited decreased static ALFF in the left inferior temporal gyrus (lITG) compared with the control group. Voxel-wised static functional connectivity (sFC) and dynamic functional connectivity (dFC) analyses using lITG as the seed region afforded complementary and overlapping results. The table tennis players exhibited decreased sFC in the right middle temporal gyrus and left inferior parietal gyrus. Conversely, they displayed increased dFC from the lITG to prefrontal cortex, particularly the left middle frontal gyrus, left superior frontal gyrus-medial, and left superior frontal gyrus-dorsolateral. These findings suggest that table tennis players demonstrate altered visuomotor transformation and executive function pathways. Both pathways involve the lITG, which is a vital node in the ventral visual stream. These static and dynamic analyses provide complementary and overlapping results, which may help us better understand the neural mechanisms underlying the changes in intrinsic brain activity and network organization induced by long-term table tennis skill training
Identification of a targeting-delivery peptide based on rhCNB
Calcineurin B subunit (CNB) is the regulatory subunit of calcineurin (CN), and its classical function is to regulate the activity of CN. Research in our laboratory has revealed that the recombinant human CNB (rhCNB) is a good antitumor candidate and can be internalized by tumor cells via TLR4 receptor complexes and targeted to tumor tissue in nude mice. However, the fragment or domain of rhCNB mediating internalization and target delivery has not been identified. To explore fragment- mediated rhCNB internalization and target delivery, we generated truncated derivatives of rhCNBs by recombinant DNA technology and examined their cellular uptake. Interactions between truncated rhCNBs and the TLR4 receptor were studied by ELISA and co-immunoprecipitation, and targeting of model tumors in nude mice was examined. The results showed that one truncated derivative, Trun3 (124-169aa), was taken up by cells and targeted tumors with almost the same efficiency as intact rhCNB. These results indicate that Trun3 (45aa) contains the major sequence responsible for rhCNB internalization and tumor targeting and might be developed for drug delivery to tumors
An Improved Triggering Updating Method of Interest Message with Adaptive Threshold Determination for Directed Diffusion Routing Protocol
Although some progress has been made in studying the triggering updating methods of interest message for reducing node energy consumption in directed diffusion routing protocols, they do not consider the anisotropy of sensing areas of nodes and the requirement of diversity of interest message exchange rates within real-time performance, which makes these studies unable to accurately adapt to the characteristics of interest message update. In this work, we proposed an improved triggering updating method (ITUM) consisted of adaptive threshold determination based on the analytic hierarchy process and update judgement by similarity comparison of interest messages. Meanwhile, the network model and the sensing model are presented to describe actual network scenarios. We analyze the impact of critical parameters and evaluate the performance of ITUM with several interest message updating methods from the aspect of lowering the number of information exchanges. The simulation results prove that ITUM can improve the adaptability to scene changes while decreasing the number of information exchanges compared with the existing methods. Furthermore, it is shown that ITUM is a highly effective solution for determining the triggering updating conditions of various information exchange rates in directed diffusion routing protocol
The immunostimulatory effects and pro-apoptotic activity of rhCNB against Lewis lung cancer is mediated by Toll-like receptor 4
Background Recombinant human calcineurin B subunit (rhCNB) has been shown to be an immune-stimulatory protein promoting cytokine production and inducing phenotypic maturation of Dendritic cells (DCs). In vivo, it has good antitumor efficacy, and has potential as an antitumor drug. Exogenous rhCNB was found to be internalized into tumor cells via the Toll-like receptor 4 (TLR4) complex, but it was not known whether its immuno-modulatory and antitumor functions involved entry by this same route. Methods The production and secretion of the cytokines and chemokines in innate immune cells induced by rhCNB were determined by ELISA, and the expression of CD40, CD80, CD86, and MHCII was analyzed by FACs. Experimental Lewis lung cancer (LLC) model was prepared in C57 BL/6 wild-type (WT) mice, TLR4(-/-) mice or their littermates by the inoculation of LLCs in their right armpit, and then administrated daily intraperitoneal injections (0.2 mL) of normal saline, rhCNB 20 mg/kg, and rhCNB 40 mg/kg, respectively. Results Recombinant human calcineurin B subunit promoted the production of antitumor cytokines by innate immune cells, and culture supernatants of rhCNB-stimulated immune cells induced apoptosis of LLCs. In addition, rhCNB up-regulated CD40, CD80, CD86, and MHCII expression in macrophages and DCs in TLR4(+) cells but failed to do so in TLR4 deficient cells. rhCNB also induced the formation of CD4(+) and CD8(+)T cells in splenocytes from WT mice, but not from TLR4-deficient littermates. Intraperitoneal administration of WT C57BL/6 mice with rhCNB resulted in a 50% reduction in LLC tumor growth, but failed to inhibit tumor growth in TLR4(-/-) littermates. Conclusions The in vivo antitumor and immunomodulatory effects of rhCNB are mediated by the TLR4. This conclusion is important for the further understanding and development of rhCNB as an antitumor drug
Occurrence and Distribution of Uranium in a Hydrological Cycle around a Uranium Mill Tailings Pond, Southern China
Uranium (U) mining activities, which lead to contamination in soils and waters (i.e., leachate from U mill tailings), cause serious environmental problems. However, limited research works have been conducted on U pollution associated with a whole soil-water system. In this study, a total of 110 samples including 96 solid and 14 water samples were collected to investigate the characteristics of U distribution in a natural soil-water system near a U mining tailings pond. Results showed that U concentrations ranged from 0.09 ± 0.02 mg/kg to 2.56 × 104± 23 mg/kg in solid samples, and varied greatly in different locations. For tailings sand samples, the highest U concentration (2.56× 104 ± 23 mg/kg) occurred at the depth of 80 cm underground, whereas, for paddy soil samples, the highest U concentration (5.22 ± 0.04 mg/kg) was found at surface layers. Geo-accumulation index and potential ecological hazard index were calculated to assess the hazard of U in the soils. The calculation results showed that half of the soil sampling sites were moderately polluted. For groundwater samples, U concentrations ranged from 0.55 ± 0.04 mg/L to 3.36 ± 0.02 mg/L with a mean value of 2.36 ± 0.36 mg/L, which was significantly lower than that of percolating waters (ranging from 4.56 ± 0.02 mg/L to 12.05 ± 0.04 mg/L, mean 7.91 ± 0.98 mg/L). The results of this study suggest that the distribution of U concentrations in a soil-water system was closely associated with hydrological cycles and U concentrations decreased with circulation path
Catalysis. Identification of molybdenum oxide nanostructures on zeolites for natural gas conversion
Direct methane conversion into aromatic hydrocarbons over catalysts with molybdenum (Mo) nanostructures supported on shape-selective zeolites is a promising technology for natural gas liquefaction. We determined the identity and anchoring sites of the initial Mo structures in such catalysts as isolated oxide species with a single Mo atom on aluminum sites in the zeolite framework and on silicon sites on the zeolite external surface. During the reaction, the initial isolated Mo oxide species agglomerate and convert into carbided Mo nanoparticles. This process is reversible, and the initial isolated Mo oxide species can be restored by a treatment with gas-phase oxygen. Furthermore, the distribution of the Mo nanostructures can be controlled and catalytic performance can be fully restored, even enhanced, by adjusting the oxygen treatment
Identification of a targeting-delivery peptide based on rhCNB
Calcineurin B subunit (CNB) is the regulatory subunit of calcineurin (CN), and its classical function is to regulate the activity of CN. Research in our laboratory has revealed that the recombinant human CNB (rhCNB) is a good antitumor candidate and can be internalized by tumor cells via TLR4 receptor complexes and targeted to tumor tissue in nude mice. However, the fragment or domain of rhCNB mediating internalization and target delivery has not been identified. To explore fragment- mediated rhCNB internalization and target delivery, we generated truncated derivatives of rhCNBs by recombinant DNA technology and examined their cellular uptake. Interactions between truncated rhCNBs and the TLR4 receptor were studied by ELISA and co-immunoprecipitation, and targeting of model tumors in nude mice was examined. The results showed that one truncated derivative, Trun3 (124-169aa), was taken up by cells and targeted tumors with almost the same efficiency as intact rhCNB. These results indicate that Trun3 (45aa) contains the major sequence responsible for rhCNB internalization and tumor targeting and might be developed for drug delivery to tumors
Spectroscopic and Computational Study of Cr Oxide Structures and Their Anchoring Sites on ZSM-5 Zeolites
Studies on the Preparation, Characterization and Intracellular Kinetics of JD27-loaded Human Serum Albumin Nanoparticles
AbstractJD27 is a derivatives of active ingredient extracted from Rabdosia which includes a functional group of 1,2,3-Triazoles. It is considered as a promising anti-cancer drug candidate because of its low toxicity and broad-spectrum anti-cancer activity. However, the clinical application of JD27 has been limited by its poor solubility. Albumin is an attractive macromolecular carrier, which has been widely used in nanoparticle preparation. Compared with other drug delivery systems, drug-loaded albumin nanoparticles showed a series of advantages such as solubilization of hydrophobic drug, biodegradable, biocompatible and so on. In this study, JD27-loaded human serum albumin nanoparticles (JD27-NPs) were obtained using an established desolvation method and they were characterized by particle size, zeta potential, encapsulation efficiency, surface morphology and in vitro drug release studies. In addition, their cytotoxic activities, intracellular kinetics and cell membranes permeability were evaluated in EC-9706 cells. The experiment results showed that the particle size, zeta potential, and encapsulation efficiency were (276.5±8.26) nm, (−41.4±7.21) mV and 82.2%±5.09%, respectively. SEM images suggest that JD27–NPs were a round shape, similar uniform size and smooth surface. Drug release studies indicated JD27-NPs had the properties of sustained release. The results of cytotoxic activities suggest that antitumor efficacy of JD27–NPs is higher than JD27 in EC-9706 cells. According to the results of intracellular kinetics, the concentration of JD27-NPs in the cell could reach the peak concentration after 2 hour and gradually decreases with time lasted. The AUC0-12h and MRT of JD27-NPs are significantly higher than that in JD27 (P<0.05). JD27-NPs have advantages to keep a higher and steadier intracellular concentration than JD27 which shows JD27-NPs have priority in application. The results of Hoechst 33258 staining suggested that the permeability of the cells membrane can be changed with the different concentration and treatment time of JD27. In conclusion, albumin nanopaticles may act as a useful and safe carrier for JD27.JD27-NPs will be a promising formulation for cancer therapy in future
Near-Infrared Triggered Upconversion Polymeric Nanoparticles Based on Aggregation-Induced Emission and Mitochondria Targeting for Photodynamic Cancer Therapy
Photodynamic
therapy (PDT) is an auspicious strategy for cancer therapy by yielding
reactive oxygen species (ROS) under light irradiation. Here, we have
developed near-infrared (NIR) triggered polymer encapsulated upconversion
nanoparticles (UCNPs) based on aggregation-induced emission (AIE)
characteristics and mitochondria target ability for PDT. The coated
AIE polymer as a photosensitizer can be photoactivated by the up-converted
energy of UCNPs upon 980 nm laser irradiation, which could generate
ROS efficiently in mitochondria and induce cell apoptosis. Moreover,
a “sheddable” poly(ethylene glycol) (PEG) layer was
easily conjugated at the surface of NPs. The pH-responsive PEG layer
shields the surface positive charges and shows stronger protein-resistance
ability. In the acidic tumor environment, PEGylated NPs lose the PEG
layer and show the mitochondria-targeting ability by responding to
tumor acidity. A cytotoxicity study indicated that these NPs have
good biocompatibility in the dark but exert severe cytotoxicity to
cancer cells, with only 10% cell viability, upon being irradiated
with an NIR laser. The AIE nanoparticles are a good candidate for
effective mitochondria targeting photosensitizer for PDT