The fenbufen loaded PLGA/chitosan nanofibrous scaffolds were fabricated by electrospinning. The hydrophilicity of nanofibrous scaffold was enhanced with the increase of chitosan content. The drug ...release also is accelerated with chitosan increasing because the higher hydrophilicity makes drug diffusing from scaffold more easily.
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▶ The average diameter increased with the increase of chitosan content and then decreased. ▶ The release rate of fenbufen increased with the increase of chitosan. ▶ The aligned nanofibrous scaffold exhibits lower drug release rate. ▶ The drug release could be controlled by crosslinking in glutaraldehyde vapor.
In this study both aligned and randomly oriented poly(
d,l-lactide-co-glycolide) (PLGA)/chitosan nanofibrous scaffold have been prepared by electrospinning. The ratio of PLGA to chitosan was adjusted to get smooth nanofiber surface. Morphological characterization using scanning electron microscopy showed that the aligned nanofiber diameter distribution obtained by electrospinning of polymer blend increased with the increase of chitosan content which was similar to that of randomly oriented nanofibers. The release characteristic of model drug fenbufen (FBF) from the FBF-loaded aligned and randomly oriented PLGA and PLGA/chitosan nanofibrous scaffolds was investigated. The drug release rate increased with the increase of chitosan content because the addition of chitosan enhanced the hydrophilicity of the PLGA/chitosan composite scaffold. Moreover, for the aligned PLGA/chitosan nanofibrous scaffold the release rate was lower than that of randomly oriented PLGA/chitosan nanofibrous scaffold, which indicated that the nanofiber arrangement would influence the release behavior. In addition, crosslinking in glutaraldehyde vapor would decrease the burst release of FBF from FBF-loaded PLGA/chitosan nanofibrous scaffold with a PLGA/chitosan ratio less than 9/1, which would be beneficial for drug release.
Reduced expression of the p53 family member p63 has been suggested to play a causative role in cancer metastasis. Here, we show that ΔNp63α, the predominant p63 isoform, plays a major role in ...regulation of cell migration, invasion and cancer metastasis. We identified mitogen-activated protein (MAP) kinase phosphatase 3 (MKP3) as a downstream target of ΔNp63α that is required for mediating these effects. We show that ΔNp63α regulates extracellular signal-regulated protein kinases 1 and 2 (Erk1/2) activity via MKP3 in both cancer and non-transformed cells. We further show that exogenous ΔNp63α inhibits cell invasion and is dependent on MKP3 upregulation for repression. Conversely, endogenous pan-p63 ablation results in increased cell migration and invasion, which can be reverted by reintroducing the ΔNp63α isoform alone, but not by other isoforms. Interestingly, these effects require Erk2, but not Erk1 expression, and can be rescued by enforced MKP3 expression. Moreover, MKP3 expression is reduced in invasive cancers, and reduced p63 expression increases metastatic frequency in vivo. Taken together, these results suggest an important role for ΔNp63α in preventing cancer metastasis by inhibition of Erk2 signaling via MKP3.
The potential of ion flotation to remove cadmium, lead and copper from dilute aqueous solution with a plant-derived biosurfactant tea saponin was investigated. The operating parameters, such as ...initial solution pH, the collector to heavy metals ratio, and the ionic strength (NaCl), have a marked influence on the performance of ion flotation, as shown in this investigation. The maximum removal of lead, copper and cadmium can reach 89.95%, 81.13% and 71.17%, respectively when the ratio of collector to metal was 3:1. The selectivity coefficients of lead over cadmium, lead over copper and cadmium over copper in the present of tea saponin were observed, and the selectivity coefficient of lead over cadmium was the highest one. The foam products were identified by Fourier transform infrared (FTIR) spectroscopy, and the result indicated that the carboxylate groups and divalent metal ions were formed definite complexation in the bulk solution.
In this paper, in order to achieve the resource utilization of metallurgical industry waste, the cracking resistance of magnesium oxysulfate cement coatings using granulated blast furnace slag powder ...and iron tailings powder as fillers was studied, x-ray Diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the hydration products. The results show that an appropriate amount of slag powder and iron tailings powder can make the internal structure of the coating more compact, the surface smooth and effectively reduce the generation of cracks.
NAC (NAM, ATAF1,2, and CUC2) transcription factors play an important role in the responses of plants to various environmental stresses. To investigate the function of SlNAC1, which was found to be a ...member of the ATAF subfamily in tomato (Solanum lycopersicum L.) plants under heat stress conditions, transgenic tomato plants were generated using an antisense technology. After a treatment at 40 °C for 48 h, in comparison with wild-type (WT) plants, the transgenic plants were severely wilted and exhibited a lower net photosynthetic rate and a maximal photochemical efficiency of photosystem II. Moreover, the transgenic plants displayed a higher ion leakage and malondialdehyde content and a lower proline content. The content of reactive oxygen species (superoxide anion radicals and hydrogen peroxide) were higher, and activities of ascorbate peroxidase and superoxide dismutase lower in the transgenic plants than in the WT plants. The transgenic plants also exhibited a lower accumulation of the transcripts of some heat shock protein genes (Hsp70, Hsp90, sHsp17.4, and sHsp17.6). All of these results suggest that the suppression of SlNAC1 could obviously reduce heat resistance in the tomato plants, and this indicates that SlNAC1 played an important role in the thermal tolerance of the tomato plants.
In this paper, in order to achieve the resource utilization of metallurgical waste, this article studied the water resistance of magnesium oxysulfate cement coating using blast furnace slag powder ...and iron tailings powder as fillers, and characterized its hydration products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results indicate that an appropriate amount of slag powder and iron tailings powder can make the internal structure of the coating more dense, effectively improve the softening coefficient, and enhance water resistance.
•The relation of thermal comfort and thermal balance between human body and surroundings is explored.•PMV model is simplified with the sensible heat loss from human body.•Human thermal comfort could ...be evaluated from thermal balance instead of environmental factors.•It is noted that sensible heat loss from human body is approximately linear with PMV.•Correlation between PPD and sensible heat loss from human body is developed.
The radiant cooling air conditioning system has been increasingly prevailed, due to its features of maintaining more comfortable indoor environment with lower energy consumption against the conventional cooling methods. This work explores the effect of heat exchange between human body and surroundings on human thermal comfort subject to the radiant cooling air conditioning system. The widely accepted thermal comfort index, PMV (Predicted Mean Vote), is adopted to evaluate human thermal comfort. To determine the heat loss from human body, the human thermal balance and heat release characteristics are discussed. The test room with various boundary conditions are simulated and analyzed by Airpak. It is found that for sedentary human body subject to the radiant cooling system, the sensible heat loss is approximately linear to the PMV and the value of sensible heat loss for the thermal neutrality (PMV=0) is a constant. The simplified PMV model is finally achieved based on the results obtained from 594 calculated points. In addition, the relation between the sensible heat loss and the PPD (Predicted Percentage of Dissatisfied) is obtained. The findings from this work could be referenced for thermal comfort evaluation and system design when radiant cooling applies.
Multi-component lithium disilicate (LD) glasses were ion-exchanged in a pure or mixed nitrate salt bath. The surface morphologies, mechanical properties, chemical stability and ion leaching of ...ion-exchanged LD glasses before and after storage in artificial saliva for 21 days were investigated. It can be found that chemical stability of ion-exchanged LD glass was temperature-dependent. The residual compressive stress induced by ion-exchange increased the chemical potential of alkali ions in glass, and the ion-exchanged LD glass, especially 235 °C/64 h group, chemical stability in artificial saliva for 21 days were deteriorated. Back-exchange treatment could relax the stress on the outermost layer of the ion-exchanged LD glass without deteriorating its strengthening effect, and back-exchanged LD glass presented good chemical and mechanical stability in artificial saliva. The results might help to enhance the service stability of ion-exchanged LD glass-ceramics in the oral condition.
•Chemical and mechanical stability of ion-exchanged LD glass was obviously degraded after storage in artificial saliva.•Chemical stability is closely related to residual stress or ion-exchange temperature.•Back-exchanged LD glass shows good chemical stability and maintaining the strengthening effect.
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