Search

Graphene oxide quantum dots (GOQDs) have broad application prospects in many areas including bioimaging, drug delivery, DNA cleavage system, sensors and photocatalyst. Recently, increasing concerns have been raised about their biocompatibility, but studies about the effects of GOQDs on male reproductive system are still lacking. In this work, we explored the effects and molecular mechanisms of GOQDs on GC-2 and TM4 cells. We found autophagosome accumulation in GC-2 and TM4 cells after GOQDs treatment. Both LC3-II/LC3-I ratio and p62 levels increased, and the chloroquine-induced accumulation of LC3-II didn’t enhance in the presence of GOQDs, which indicated that GOQDs blocked autophagic flux. Further studies found that the fusion between autophagosome and lysosome was not inhibited by GOQDs, but the proteolytic capacity of lysosome was weakened and both the expression and activity of cathepsin B reduced. Taken together, these results suggested that GOQDs blocked autophagic flux by decreasing the amount and enzymatic activity of cathepsin B and inhibiting lysosome proteolytic capacity in GC-2 and TM4 cells, which might have a potential hazard to male reproduction. [ABSTRACT FROM AUTHOR]

This paper investigates the impact of post-metallization annealing (PMA) in pure nitrogen ambient on the reliability of 65 nm NOR-type floating-gate flash memory devices. The experimental results show that, with PMA process, the cycling performance of flash cells, especially for the erasing speed is obviously degraded compared to that without PMA. It is found that the bulk oxide traps and tunnel oxide/Si interface traps are significantly increased with PMA treatment. The water/moisture residues left in the interlayer dielectric layers diffuse to tunnel oxide during PMA process is considered to be responsible for these traps generation, which further enhances the degradation of erase performance. Skipping PMA treatment is proposed to suppress the water diffusion effect on erase performance degradation of flash cells. [ABSTRACT FROM AUTHOR]

High quality AlGaN material growth and chip fabrication of monolithically integrated solar blind light-emitting diodes (LEDs), waveguides and photodetectors (PDs) on an AlGaN multi-quantum wells (MQWs) wafer are presented. The strong light constraint of waveguides is confirmed, in virtue of predominant ultraviolet transverse magnetic (TM) modes in transverse transmission. Unaffected by the ambient lighting, the PDs demonstrate sufficient photosensitivity to the optical signal traveling along waveguides owing to the emission-responsion spectral overlap. When the LEDs are operated at 20 mA current, the photo-to-dark current ratio (PDCR) in the PDs is up to seven orders of magnitude, which is higher than previously reported values for self-driven nitride PDs. The responsivity, specific detectivity and external quantum efficiency (EQE) of self-driven PDs are 186 A/W, 2.54 × 1014 Jones and 8.4 × 104%, respectively. Benefiting from the effective optical isolation, the light crosstalk between adjacent devices is effectively reduced about 70%. The self-driven PDs exhibit 127/131 ns (rise/decay) rapid response in the on-chip communication. This work opens a pathway to drastically improve the ultraviolet-C (UVC) monolithically integrated systems and extends the fields of application in solar-blind communication. [Display omitted] • UVC photoelectric integrated chips based on high quality AlGaN MQWs are successfully fabricated. • The AlGaN waveguide is designed to strengthen optical constraints, enabling lower optical crosstalk. • Integrated UVC on-chip communication is demonstrated with high-speed response. [ABSTRACT FROM AUTHOR]

Recently Graphene (Gr) becomes a promising candidate for the integration of devices as a Schottky contact. In this study, Pt/Gr/GaN and Pt/GaN SBDs were fabricated to determine the Gr interlayer effect on the electrical characteristics of the devices. The temperature and frequency dependent capacitance-voltage (C–V), conductance-voltage (G/ω–V), and current-voltage (I–V) are measured, from which the Schottky barrier height (SBH), reverse leakage, the density of interface states (N ss), and time constants are derived. The results reveal SBDs with Gr interlayer exhibited higher SBH and lower leakage current. The N ss for the Pt/GaN SBD were in the range of 2 × 1013 to 2.33 × 1013 eV−1cm−2 at (E C – 0.35) to (E C – 0.62) eV, while the value for Pt/Gr/GaN SBD varies in the range of 1.85 × 1013 to 2.02 × 1013 eV−1cm−2 at (E C – 0.57) to (E C – 0.84) eV. The N ss of Pt/Gr/GaN is reduced and the distribution shifts toward the mid-gap of GaN in comparison with Pt/GaN. It is considered that the modulation of the interface states is attributed to the passivation of chemically inert Gr interlayer. [ABSTRACT FROM AUTHOR]

High delicate particulate matter (PM 2.5) concentration can seriously reduce air quality, destroy the environment, and even jeopardize human health. Accordingly, accurate prediction for PM 2.5 plays a vital role in taking precautions against upcoming air ambient pollution incidents. However, due to the disturbance of seasonal and nonlinear characteristics in the raw series, pronounced forecasts are confronted with tremendous handicaps, even though for seasonal grey prediction models in the preceding researches. A novel seasonal nonlinear grey model is initially designed to address such issues by integrating the seasonal adjustment factor, the conventional Weibull Bernoulli grey model, and the cultural algorithm, simultaneously depicting the seasonality and nonlinearity of the original data. Experimental results from PM 2.5 forecasting of four major cities (Shanghai, Nanjing, Hangzhou, and Hefei) in the YRD validate that the proposed model can obtain more accurate predictive results and stronger robustness, in comparison with grey prediction models (SNGBM(1,1) and SGM(1,1)), conventional econometric technology (SARIMA), and machine learning methods (LSSVM and BPNN) by employing accuracy levels. Finally, the future PM 2.5 concentration is forecasted from 2020 to 2022 using the proposed model, which provides early warning information for policy-makers to develop PM 2.5 alleviation strategies. [Display omitted] • A novel seasonal grey model is used to predict PM2.5 concentration in the YRD region. • The Cultural Algorithm is used for effectively identifying the coefficients. • Comparative studies exhibit the robustness and reliability of the new model. • The future PM2.5 concentrations are forecasted by the new model from 2020 to 2022. • Some corresponding policy strategies to mitigate PM2.5 pollution are put forward. [ABSTRACT FROM AUTHOR]

Connexin 43 (Cx43) is believed to play a role in the mechanisms of toxicity of many chemical species, include cadmium (Cd). In this study, human renal proximal tubule (HK-2) cells were exposed to Cd (1 μM, 10 days). Of the 584 protein residues detected using a Phospho Explorer antibody microarray (PEX100), more than half changed their levels of phosphorylation after chronic Cd exposure. Cx43 siRNA attenuated Cd-induced apoptosis and inhibited proliferation, while also attenuating changes in the levels of phosphorylation of many protein residues. According to DAVID Bioinformatics Resources analysis and KEGG PATHWAY database, AKT signal pathway may be the important one. Focusing on the AKT pathway confirmed that Cx43 mediated increased levels of p-PTEN Ser380/Ser382/Thr383 and decreased levels of p-AKT Thr308 , p-AKT Tyr326 , p-ASK1 Ser83 , and p-p27 Thr187 , thereby possibly contributing to the Cd-induced apoptosis and inhibited proliferation. These results suggested that AKT pathway was the dominant pathway involved in Cx43-mediated chronic Cd toxicity. [ABSTRACT FROM AUTHOR]

Heat stress (HS) is a potential harmful factor for male reproduction. However, the effect of HS on Sertoli cells is largely unknown. In this study, the metabolic changes in Sertoli cell line were analyzed after HS treatment. Metabolomic analysis revealed that carnitine, 2-hydroxy palmitic acid, nicotinic acid, niacinamide, adenosine monophosphate, glutamine and creatine were the key changed metabolites. We found the expression levels of BTB factors (Connexin43, ZO-1, Vimentin, Claudin1, Claudin5) were disrupted in TM-4 cells after HS treatment, which were recovered by the addition of carnitine. RT-PCR indicated that the mRNA levels of inflammatory cytokines (IL-1α, IL-1β, IL-6) were increased after HS treatment, and their related miRNAs ( miR-132 , miR-431 , miR-543 ) levels were decreased. Our metabolomic data provided a novel understanding of metabolic changes in male reproductive cells after HS treatment and revealed that HS-induced changes of BTB factors and inflammatory status might be caused by the decreased carnitine after HS treatment. [ABSTRACT FROM AUTHOR]

Highlights: [•] An 8-level 3-bit cell programming technique is presented in SONOS memory devices. [•] This new programming mode enlarges one time programming and sensing window. [•] The storage density of the 8-level cell is greatly improved. [•] The cycling endurance and retention properties are not obviously degraded. [ABSTRACT FROM AUTHOR]

The core-shell structure H-MnO 2 @PANI own excellent impedance matching characteristics (Figure b), and exist abundant interfaces that can produce strong interface polarization and enhance the loss of electromagnetic waves (Figure a), the minimum reflection loss is −52.06 dB (Figure b). The PANI bridge connects MnO 2 as a whole (Figure c), resulting in conductance loss dissipates electromagnetic waves and increases the effective absorption bandwidth to 4.56 GHz (Figure d). • The multi-interface structure MnO 2 @PANI is prepared by a mild self-template method. The surface modification enhanced the affinity of MnO 2 to AN, which made it possible to obtain the core-shell structure of MnO 2 @PANI successfully. • A series of MnO 2 -based products with multi-interface structure are obtained by simple self-template oxidation-etching strategy. The multi-interface structure is conducive to enhance the attenuation loss of polarization effect on electromagnetic wave. • RL min of H-MnO 2 @PANI is −52.06 dB at 8.48 GHz, and it has a broadband absorption of 4.56 GHz. Its excellent microwave absorption performance is attributed to the synergistic effect of conductivity loss, interface polarization and multiple reflection loss. Nowadays, high-frequency electromagnetic pollution makes the lightweight and high-efficiency absorption materials become the research hotspot. In this paper, the hollow structure MnO 2 @PANI microsphere composite was reasonably synthesized by self-template strategy and in-situ polymerization. Coating conductive polyaniline (PANI) on the modified surfaces of MnO 2 microsphere not only can improve the impedance matching and microwave absorption ability, but also solve the drawback of low loss intensity as well as narrow absorption band of pure MnO 2. The conductive polymer PANI conductance loss, MnO 2 -PANI multiple interfacial polarization and multiple reflection loss synergy endows hollow MnO 2 @PANI microsphere excellent microwave absorption performance. The RL min of hollow MnO 2 @PANI microsphere is −52.06 dB at 8.48 GHz and has a wide absorption of 4.56 GHz. Those positive results show that the pure dielectric MnO 2 @PANI microsphere material with a multi-interface hollow core-shell structure prepared from a template is a lightweight and efficient absorbent. [ABSTRACT FROM AUTHOR]

• The road base course binder (RBCB) is a slow setting and slight expansive cement. • Road base course stabilized by RBCB has higher properties and anti-cracking. • The engineering application proved RBCB has lower cost while higher performance. Reflecting cracks of asphalt pavement induced mainly by shrinkage crack of road base course become one of the most common pavement diseases in highway. To compensate the shrinkage of stabilized road base course, a slow setting slight-expansive cement was designed as road base course binder (RBCB) and the properties of road base course with RBCB were investigated. Furthermore, the RBCB's shrinkage compensation effect, the performance of RBCB stabilized crushed stone and its applications are studied in this article. RBCB has longer setting time and its 28-day strength is almost equal to 32.5 grade Portland slag cement (P.S 32.5). RBCB has slight expansion characteristics, it can effectively compensate the shrinkage of the cement, thus its volume stability under both wetting-drying and drying-wetting scenario is improved. The road base course stabilized by RBCB has higher mechanical properties and substantially lesser shrinkage crack than the ordinary cement stabilizing road base course. RBCB has low construction costs and outstanding performance in practical applications. Hence, it is an effective approach to lessen the pavement cracking by developing slow setting and expansive road base stabilizer compensate the shrinkage of road base materials. [ABSTRACT FROM AUTHOR]

Abstract To improve the utilization efficiency of steel slag in cement industry, cement clinkers are prepared by simulated multi-phased clinker sintering technology with crushed steel slag (without grinding). The results show that after high temperature treatment, the inert components and tough phases of steel slag such as iron phase, calcium ferrite phase and RO phase (CaO FeO MnO MgO solid solution) are reduced; the soundness, grindability and hydration activity of steel slag can be certainly improved; hydration activity of the multi-phased cement at early age is a little lower than that of grade 42.5 ordinary Portland cement, while develops faster than later. The multi-phased cement clinker prepared at 1400 °C with the raw material contains 16.86% steel slag has comparable grindability and soundness to the normal Portland cement clinker. Compared to traditionally using steel slag as a cement raw meal, the multi-phased clinker sintering technology has much greater technical and economic advantage. It is a promising approach to the extensive utilization of steel slag in cement industry. Graphical abstract Image 104929 Highlights • A multi-phased clinker sintering technology is put forward to massively utilize steel slag. • Multi-phased clinker has steel slag with improved soundness, grindability and activity. • Activation energy of clinker calcination decreases with the addition of steel slag. • Strength of multi-phased clinker can reach the standard of PO 42.5 cement. [ABSTRACT FROM AUTHOR]

Abstract RAC produced with crushed recycled aggregate (RA) is regarded as an environmental friendly material, while its high water demand, high mortar content and low modulus have restricted its application. Scattering-filling coarse aggregate (SFCA) process was applied to prepare the recycled aggregate concrete with promoted performance. With the reference of conventional concrete and the scattering-filling natural aggregate (SFNA) concrete, the influences of ratio, type, size and moisture state of RA on mechanical and durable properties of scattering-filling recycled aggregate (SFRA) concrete were investigated. The results indicate that SFCA process could improve the compressive strength, elastic modulus, and reduce the drying shrinkage and chloride penetration. The frost resistance of SFRA is comparable with the conventional concrete. With 10–20 mm scattering-filling aggregate of RA, SFCA concretes get more significant improvement on elastic modulus and anti-permeability; Higher water content of RA worsen the performance of recycled aggregate concrete (RAC) for water in the RA weakening ITZ; Furthermore, image processing analysis and microhardness indicated that SFCA process improve the properties by increasing the homogeneity of aggregate distribution and improving ITZ between the aggregate and cement paste in RAC. SFCA process provides an economic method to produce high-quality recycled aggregate concrete and an efficiently approach to the utilization of recycled concrete aggregate from Construction and Demolition waste. [ABSTRACT FROM AUTHOR]

In corrosion environment, corrosion ions can easily penetrate from the surface into the inside of the concrete due to the porous structure of the surface; in this case, concrete can inevitably suffer from the damage. In this study, an attempt to use nano SiO 2 (NS) and silica fume (SF) modifying cement mortar as a Surface Protection Material (SPM) was made, in order to promote penetration resistance of the whole system. SPM was coated on the surface of matrix, and then interfacial bond strength between matrix and SPM was measured; shrinkage consistency was also considered; the chloride penetrability of the system was examined as well. To reveal the mechanism, effect of NS and SF on pore structure, Interfacial Transition Zone (ITZ), hydration process, and compressive strength of SPM were investigated. The results show that matrix coated with SPM on the surface has a good integrity, with excellent interfacial bond strength and little difference in shrinkage, and chloride diffusion coefficient of the system was considerably declined, in comparison with the matrix, showing an excellent penetration resistance. The mechanism behind is that SPM, which was modified with SF-NS, shows the excellent impermeability, and this kind of material existing on the surface can noticeably obstruct the chloride ions penetrating into the inside. In cement hydration process, SF and NS can not only consume a large amount of CH to form dense C-S-H, but also exert the grading filling effect, resulting in the decline in porosity, the increase in density, the improvement in microstructure of ITZ, and the enhancement in mechanical performance. The findings can provide useful experience for the design of the cement-based materials servicing in high corrosion environment. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) have been used clinically and experimentally to relieve severe immune-related diseases due to their immunomodulatory properties, but these are impaired by inflammation. Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory mucosal disease. In the present study, we found MSCs from OLP with higher expression of interleukin (IL)-6, tumour necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β) and IL-10 compared with control. Total glucosides of paeony (TGP) significantly improves the immunomodulatory function of MSCs by inhibiting IL-6 and TNF-α expression and increasing TGF-β and IL-10 expression. Moreover, TGP can downregulate p -STAT3 expression through upregulation of miR-124. The changes of IL-6, TGF-β and p -STAT3 were further confirmed by overexpression and knockdown of miR-124 in MSCs. Taken together, the immune-regulating function of MSCs can be improved by TGP via the miR-124/STAT3 pathway. [ABSTRACT FROM AUTHOR]

Abstract: A new method for stress testing based on the theory of Barkhausen noise has been introduced using changing feature values for monitoring stress and temperature. However, changes in temperature not only have an effect on the stress but also the MBN signal itself. In order to get the accurate stress value and eliminate the temperature effect, we proposed a data processing method for stress testing based on MBN. The study found that within the steel elastic range, the Barkhausen noise feature values, including mean value, RMS value, ring numbers, peak value and the ratio of envelope peak and full peak width at half of maximum amplitude decrease with increasing temperature, there is a fixed monotonic relationship which provides a theoretical basis for building the back propagation (BP) neural network model, with stress as the output value and temperature, mean value, RMS value, ring numbers, peak value and the ratio of peak and full width of half maximum as the input values. The MATLAB 7.8.0 neural network toolbox was used to model and simulate the neural network and samples used to validate the trained BP neural network. The results showed that the network had a high degree of accuracy and generalization ability, to get the values of stress. [Copyright &y& Elsevier]