188 research outputs found

    Histochemical Investigation and Kinds of Alkaloids in Leaves of Different Developmental Stages in Thymus quinquecostatus

    Get PDF
    Thymus quinquecostatus, with more medical value, is a kind of wild plants. In order to exploit and utilize this plant, we studied the species and locations of alkaloids in its leaves. In this paper, histochemical study of leaves at different developing stages was taken to localize the alkaloids. Meanwhile, the kinds and content of alkaloids in leaves were identified using GC-MS technique. It was found that there were two kinds of glandular trichomes, namely, peltate trichomes and capitate trichomes, on the surface of leaves, and their secretory cells could secrete alkaloids. Results showed that trichomes could secrete alkaloids as soon as the first pair of leaves formed, and there were altogether 18 kinds of alkaloids identified by GC-MS. Nearly all of these alkaloids of leaves at different developing stages were distinct from each other, except one, 3-methoxy-a-methyl-benzeneethanamine, persists at different developing stages with high concentration

    Numerical simulation of the fluid dynamics within the tissue engineering scaffolds micro-tubes

    Full text link
    The core of tissue engineering is the fabrication of a complex three-dimensional space with cells and biomaterials. In the development of porous scaffolds in vitro, no matter the seed cells ran into the scaffold, or its excretion of waste discharged scaffolds, they both need the nutrient solution to be brought into or taken out. Therefore, the flow of the nutrient solution, cells and metabolic waste for the profitable living in vitro culture plays a significant role. the paper constructed bone scaffold models of different geometric parameters, analog cells, and nutrient solution flow conditions in the scaffolds using the FLUENT software. By making a contrastive analysis with the simulated result, the internal organizational design parameters of scaffold for tissue engineering is optimized and a certain amount of data and a theoretical basis for the internal bone scaffold structure design is provided

    Structural and functional changes of the cerebellum in temporal lobe epilepsy

    Get PDF
    AimsThis study aimed to comprehensively explore the cerebellar structural and functional changes in temporal lobe epilepsy (TLE) and its association with clinical information.MethodsThe SUIT toolbox was utilized to perform cerebellar volume and diffusion analysis. In addition, we extracted the average diffusion values of cerebellar peduncle tracts to investigate microstructure alterations. Seed-based whole-brain analysis was used to investigate cerebellar–cerebral functional connectivity (FC). Subgroup analyses were performed to identify the cerebellar participation in TLE with/without hippocampal sclerosis (HS)/focal-to-bilateral tonic–clonic seizure (FBTCS) and TLE with different lateralization.ResultsTLE showed widespread gray matter atrophy in bilateral crusII, VIIb, VIIIb, left crusI, and left VIIIa. Both voxel and tract analysis observed diffusion abnormalities in cerebellar afferent peduncles. Reduced FC between the right crus II and the left parahippocampal cortex was found in TLE. Additionally, TLE showed increased FCs between left lobules VI–VIII and cortical nodes of the dorsal attention and visual networks. Across all patients, decreased FC was associated with poorer cognitive function, while increased FCs appeared to reflect compensatory effects. The cerebellar structural changes were mainly observed in HS and FBTCS subgroups and were regardless of seizure lateralization, while cerebellar–cerebral FC alterations were similar in all subgroups.ConclusionTLE exhibited microstructural changes in the cerebellum, mainly related to HS and FBTCS. In addition, altered cerebellar–cerebral functional connectivity is associated with common cognitive alterations in TLE

    Novel core/void/shell composite phase change materials for high temperature thermal energy storage

    Get PDF
    Abstract(#br)Metallic solid-liquid phase change materials (SLPCMs) are crucial for the thermal energy storage technology of various industrial systems. However, the encapsulation of metallic SLPCMs is still technically difficult. In this pursuit, the present research envisaged the development of a novel technology to successfully prepare the core(=Al-Si/Bi)/void/shell(=Al 2 O 3 ) composite SLPCMs by using Al/Bi immiscible alloy powders as starting material and tetraethoxysilane as SiO 2 source. The Al-Si alloy and Al 2 O 3 shell were in-situ synthesized by the displacement reaction between SiO 2 and molten Al. Interestingly, most of the Bi distributed in the shell of Al/Bi immiscible alloy powders could not only improve the activity of alloy powders and promote the formation of precursor shell, but also be recycled by evaporation to form the void layer during the calcination process of composite SLPCMs. The produced void layer provided a space buffer to alleviate the volume expansion of the core SLPCM, and thereby improving the thermal cycling stability of the prepared composite SLPCMs. The thermal cycling test results showed that after 300 thermal cycles, the melting latent heat reduction of the core(=Al-Si/Bi)/void/shell(=Al 2 O 3 ) composite SLPCMs (24.3-31.7J/g) was much less than that of the core(=Al-Si)/shell(=Al 2 O 3 ) composite SLPCM (58.1J/g). Moreover, the prepared Al-Si/Bi/Al 2 O 3 exhibited an adjustable melting temperature (571.9℃ to 631.9℃) and average particle diameter (39.3μm to 112.6μm), relatively high thermal conductivity [2.068W(mK) -1 to 2.966W(mK) -1 ], and excellent thermal energy storage capacity (209.5J/g to 278.2J/g). Thus, the prepared Al-Si/Bi/Al 2 O 3 composite SLPCMs are potential thermal energy storage materials, which can be used to improve the energy efficiency of various industrial systems

    A strategy for designing microencapsulated composite phase change thermal storage materials with tunable melting temperature

    Get PDF
    Abstract(#br)Thermal energy storage technology with high temperature phase change materials (PCMs) plays an increasingly important role in the concentrated solar power plants and industrial waste heat recovery systems. In this study, a novel displacement reaction between tetraethoxysilane as SiO 2 source and molten raw Al powder was purposed to successfully prepare Al-Si/Al 2 O 3 high temperature composite PCMs. Interestingly, by proposed synthetic methodology, we not only achieved the in-situ synthesis of Al-Si alloy PCM and Al 2 O 3 shell, but also realized the controllability of Al-Si alloy composition and Al 2 O 3 shell layer thickness. Our results indicated that the melting temperature of the prepared composite PCMs depended on the composition of Al-Si alloy, and could be designed within a certain temperature range (from 574.0 °C to 641.4 °C), instead of a particular temperature point. The melting temperature adjustability of the prepared composite PCMs provided an additional flexibility in different working temperature conditions. Moreover, the prepared composite PCMs exhibited a relatively high thermal storage capacity (248.6 J/g to 331.0 J/g), good thermal stability, excellent repeatable utilization property and certain shell layer self-repairing ability in the working temperature range. Therefore, the prepared composite PCMs can prove to be promising thermal energy storage materials for improving the energy efficiency in various systems under different working temperature conditions

    Coadministration of bedaquiline and pyrifazimine reduce exposure to toxic metabolite N-desmethyl bedaquiline

    Get PDF
    Background: A new, effective anti-tuberculosis (TB) regimen containing bedaquiline (BDQ) and pyrifazimine (TBI-166) has been recommended for a phase IIb clinical trial. Preclinical drug–drug interaction (DDI) studies of the combination of BDQ and TBI-166 have been designed to support future clinical trials. In this study, we investigated whether a DDI between BDQ and TBI-166 affects the pharmacokinetics of BDQ.Methods: We performed in vitro quantification of the fractional contributions of the fraction of drug metabolism by individual CYP enzymes (fm) of BDQ and the inhibition potency of key metabolic pathways of TBI-166. Furthermore, we conducted an in vivo steady-state pharmacokinetics study in a murine TB model and healthy BALB/c mice.Results: The in vitro fm value indicated that the CYP3A4 pathway contributed more than 75% to BDQ metabolism to N-desmethyl-bedaquiline (M2), and TBI-166 was a moderate (IC50 2.65 µM) potential CYP3A4 inhibitor. Coadministration of BDQ and TBI-166 greatly reduced exposure to metabolite M2 (AUC0-t 76310 vs 115704 h ng/mL, 66% of BDQ alone), whereas the exposure to BDQ and TBI-166 did not changed. The same trend was observed both in healthy and TB model mice. The plasma concentration of M2 decreased significantly after coadministration of BDQ and TBI-166 and decreased further during treatment in the TB model.Conclusions: In conclusion, our results showed that the combination of BDQ and TBI-166 significantly reduced exposure to the toxic metabolite M2 by inhibiting the activity of the CYP3A4 pathway. The potential safety and efficacy benefits demonstrated by the TB treatment highly suggest that coadministration of BDQ and TBI-166 should be studied further

    Expression and purification of soluble single-chain Fv against human fibroblast growth factor receptor 3 fused with Sumo tag in Escherichia coli

    Get PDF
    Background: Overexpression or mutated activation of Fibroblast growth factor receptor 3 (FGFR3) is involved in the pathogenesis of many tumors. More and more studies focus on the potential usage of therapeutic antibodies against FGFR3. Results: In this study, a novel single-chain Fv (ScFv) against FGFR3 was prepared and characterized. To achieve the soluble expression, ScFv was fused with Sumo (Small ubiquitin-related modifier) by polymerase chain reaction (PCR), and cloned into pET-20b. The recombinant bacteria were induced by 0.5 mM Isopropyl-\u3b2-D-thiogalactopyranoside (IPTG) for 16 h at 20\ub0C, and the supernatant liquid of Sumo-ScFv was harvested and purified by Ni-NTA chromatography. After being cleaved by the Sumo protease, the recombinant ScFv was released from the fusion protein, and further purified by Ni-NTA chromatography. The purity of ScFv was shown to be higher than 95% and their yield reached 4 mg per liter of bacterial culture. In vitro data showed that ScFv can significantly attenuate FGF9-induced phosphorylation of FGFR3. Conclusion: We provide a novel method to produce soluble expression and bioactive functions of ScFv in Escherichia coli

    Synthesis and White-Light Emission of ZnO/HfO2: Eu Nanocables

    Get PDF
    ZnO/HfO2:Eu nanocables were prepared by radio frequency sputtering with electrospun ZnO nanofibers as cores. The well-crystallized ZnO/HfO2:Eu nanocables showed a uniform intact core–shell structure, which consisted of a hexagonal ZnO core and a monoclinic HfO2 shell. The photoluminescence properties of the samples were characterized. A white-light band emission consisted of blue, green, and red emissions was observed in the nanocables. The blue and green emissions can be attributed to the zinc vacancy and oxygen vacancy defects in ZnO/HfO2:Eu nanocables, and the yellow–red emissions are derived from the inner 4f-shell transitions of corresponding Eu3+ ions in HfO2:Eu shells. Enhanced white-light emission was observed in the nanocables. The enhancement of the emission is ascribed to the structural changes after coaxial synthesis
    corecore