Search

Objective: We aimed to construct the ferritin autophagy regulatory network and illustrate its mechanism in ferroptosis, TME immunity and malignant phenotypes of ovarian cancer. Methods: First, we used Western blot assays and immunohistochemistry to detect the pathway expression in ovarian cancer samples (C-MYC, NCOA4). Then, we performed RIP and FISH analysis to verify the targeted binding of these factors after which we constructed ovarian cancer cell models and detected pathway regulator expression (NCOA4). Co-localization and Western blot assays were used to detect ferritin autophagy in different experimental groups. We selected corresponding kits to assess ROS contents in ovarian cancer cells. MMP was measured using flow cytometry and mitochondrial morphology was observed through TEM. Then, we chose Clone, EdU and Transwell to evaluate the proliferation and invasion abilities of ovarian cancer cells. We used Western blot assays to measure the DAMP content in ovarian cancer cell supernatants. Finally, we constructed tumor bearing models to study the effect of the C-MYC pathway on ovarian cancer tumorigenesis and TME immune infiltration in in vivo conditions. Results: Through pathway expression detection, we confirmed that C-MYC was obviously up-regulated and NCOA4 was obviously down-regulated in ovarian cancer samples, while their expression levels were closely related to the malignancy degree of ovarian cancer. RIP, FISH and cell model detection revealed that C-MYC could down-regulate NCOA4 expression through directly targeted binding with its mRNA. Ferritin autophagy and ferroptosis detection showed that C-MYC could inhibit ferroptosis through NCOA4-mediated ferritin autophagy, thus reducing ROS and inhibiting mitophagy in ovarian cancer cells. Cell function tests showed that C-MYC could promote the proliferation and invasion of ovarian cancer cells through the NCOA4 axis. The Western blot assay revealed that C-MYC could reduce HMGB1 release in ovarian cancer cells through the NCOA4 axis. In vivo experiments showed that C-MYC could promote tumorigenesis and immune evasion in ovarian cancer cells through inhibiting HMGB1 release induced by NCOA4-mediated ferroptosis. Conclusion: According to these results, we concluded that C-MYC could down-regulate NCOA4 expression through directly targeted binding, thus inhibiting ferroptosis and promoting malignant phenotype/immune evasion in ovarian cancer cells through inhibiting ferritin autophagy. [ABSTRACT FROM AUTHOR]

Platinum (Pt) nanoparticles with diameters d less than 10 nm are almost invisible to THz radiation. However, they demonstrates high absorption in infrared (IR) and visible region. Mie scattering theory under the assumption of d far less than λ, suggests the prominent inhibition of absorption and scattering due to the long wavelength character and the extremely large imaginary part of the dielectric function of Pt in THz region. The results are useful for THz photonics as dichromic filters for THz telecommunication. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer (GC) carries significant morbidity and mortality globally. An increasing number of studies have confirmed that circular RNA (circRNA) is tightly associated with the carcinogenesis and development of GC, especially acting as a competing endogenous RNA for miRNAs. Objective: Our study aimed to construct the circRNA-miRNA-mRNA regulatory network and analyze the function and prognostic significance of the network using bioinformatics tools. Methods: We first downloaded the GC expression profile from the Gene Expression Omnibus database and identified differentially expressed genes and differentially expressed circRNAs. Then, we predicted the miRNA-mRNA interaction pairs and constructed the circRNA-miRNA-mRNA regulatory network. Next, we established a protein-protein interaction network and analyzed the function of these networks. Finally, we primarily validated our results by comparison with The Cancer Genome Atlas cohort and by performing qRT-PCR. Results: We screened the top 15 hub genes and 3 core modules. Functional analysis showed that in the upregulated circRNA network, 15 hub genes were correlated with extracellular matrix organization and interaction. The function of downregulated circRNAs converged on physiological functions, such as protein processing, energy metabolism and gastric acid secretion. We ascertained 3 prognostic and immune infiltration-related genes, COL12A1, COL5A2, and THBS1, and built a nomogram for clinical application. We validated the expression level and diagnostic performance of key prognostic differentially expressed genes. Conclusions: In conclusion, we constructed two circRNA-miRNA-mRNA regulatory networks and identified 3 prognostic and screening biomarkers, COL12A1, COL5A2, and THBS1. The ceRNA network and these genes could play important roles in GC development, diagnosis and prognosis. [ABSTRACT FROM AUTHOR]

Ultrasonic disintegration is a very promising sludge pretreatment method that leverages the cavitation effect to produce extreme physical environments characterized by high temperatures and high pressures. This process disintegrates sludge structure features, promotes sludge dewatering, and aides resource recovery. This paper presents a newly designed continuous ultrasonic sludge treatment device. The characteristics of the ultrasonic wave propagated in the activated sludge were simulated, with the results showing that at lower frequencies, the acoustic pressure energy distribution exhibits more local concentrations, whereas at 80 kHz, the energy distribution is relatively uniform as a result of the interference of standing waves. Subsequently, activated sludge was ultrasonically treated with different exposure times and frequencies. The sludge’s capillary suction time, particle size, and moisture content were measured. The results showed different trends for each of the investigated parameters. The dewatering performance was best when the exposure time was 5–10 s. Finally, different substances were added to the ultrasonically treated sludge to analyze the effects of ultrasonic treatment on anaerobic digestion. The gas production rate was higher when glucose was the added substance than it was for yeast. The highest total concentration of produced gas, including both hydrogen and methane, was 34% for an ultrasonic input power of 200 W at a 25 kHz frequency, an exposure time of 20 s, and with 30 g of added glucose. The gas production rate was found to be higher at the lower frequency when frequency was the only variable. These experiments demonstrate that ultrasonic treatment can change the structure of sludge particles and the moisture content of the sludge, improving sludge dewatering performance. Furthermore, after ultrasonic treatment can improve gas production. [ABSTRACT FROM AUTHOR]

Perovskite compounds are always the focus in the material research field. Herein, the polycrystalline samples and single crystals of Na 2 ZrTeO 6 , a B-site ordered double-perovskite compound, were prepared successfully. Single crystal X-ray diffraction demonstrated that Na 2 ZrTeO 6 crystallizes in the cubic space group Fm-3m (No. 225) with unit parameters of a = b = c = 7.80360(10) Å. The crystal structure of Na 2 ZrTeO 6 , formed by ZrO 6 and TeO 6 octahedra through sharing the corner oxygen atoms, belongs to the typical rock-salt-type perovskite structure. The density functional theory calculations show that Na 2 ZrTeO 6 has a direct band gap with band gap of 3.21 eV, which is lower than the experimental value of 3.85 eV. Interestingly, the powder samples of Na 2 ZrTeO 6 exhibit a self-activated near-infrared emission centered at 780 nm under ultraviolet light excitation. And a strong luminescence thermal stability was also observed. Compared to room temperature, the luminescence intensity can maintain 64 % at 200 °C. [Display omitted] • The high-purity double-perovskite Na 2 ZrTeO 6 samples were synthesized by wet chemical method. • Structure analysis indicate that Na 2 ZrTeO 6 belongs to the typical rock-salt-type perovskite structure. • Na 2 ZrTeO 6 exhibits self-activated near-infrared emission centered at 780 nm excited by 308 nm. • The sample's emission intensity maintained 64 % of its room temperature peak intensity at 200 °C. [ABSTRACT FROM AUTHOR]

We present an anisotropic property investigation of the free-standing single-walled carbon nanotube (SWCNT) random networks by terahertz time-domain spectroscopy (THz-TDS). Strongly anisotropic transmission in the spectral region 0.3–2.5 THz is observed. The experimental observation implies that our pristine SWCNT networks show preferential order in micrometer scale, which are attributed to the formation of the texture pattern. Modulation of this exceptional anisotropy by mechanical stretching and light illuminating indicates that the anisotropic response can be enhanced. The light-induced anisotropic property shows a hyperbolic tangent dependence with the pump power. The results suggest the potential applications and manipulations of SWCNT networks for THz electro-optical and polarized devices. [ABSTRACT FROM AUTHOR]

Abstract: Curing kinetics of a bisphenol-A glycidol ether epoxy resin (DGEBA)/2-ethyl-4-methylimidazole (EMI-2,4)/nano-sized SiC(nano-SiC) system was investigated with two kinetic methods by means of differential scanning calorimetry (DSC). Methods I and II were deduced by assuming a constant E and a variable E, respectively. With method I, the cure reaction activation energy E, the frequency factor A and the overall order of reaction m+n are calculated to be 71.75kJmol−1, e20.55 and 2.20, respectively. These results were used to have a simple qualitative comparison with the DGEBA/EMI-2,4 system. With method II, E is proved to decrease initially, and then increase as the cure reaction proceeds. The value of E spans from 42.4 to 95.8kJmol−1. Furthermore, the variations of E were also used to study the cure reaction mechanism, and the shrinking core model was used to study the resin–particle reaction. Methods I and II are effective as long as they are used in proper aspects. With these two methods used all together, we can have a comprehensive and in-depth understanding of the curing kinetics of the DGEBA/EMI-2,4/nano-SiC system and the effect of nano-SiC particles on the curing kinetics of the DGEBA/EMI-2,4 system. [Copyright &y& Elsevier]

Abstract: The influence of nano-sized carborundum (nano-SiC) particles and amino silane coupling agent on the curing kinetics of bisphenol-A glycidol ether epoxy resin (DGEBA) initiated with 2-ethyl-4-methylimidazole (EMI-2,4) was studied by means of non-isothermal differential scanning calorimetry (DSC). Besides decreasing the heat of reaction ΔH, the presence of nano-SiC particles results in delayed cure reactions, which is also manifested by the increased values of exothermic peak temperature T p and cure reaction activation energy E of the filled systems. Meanwhile, the amino silane coupling agent could increase ΔH, and decrease slightly the degree of delayed cure reactions caused by nano-SiC particles, and thereby decreasing T p of the filled systems. The presence of nano-SiC particles prevents from the occurrence of vitrification, so does the amino silane coupling agent when the nano-SiC particle content is low (≲15wt%). As the nano-SiC particle content is high (≳15wt%), the presence of amino silane coupling agent promotes the occurrence of vitrification. Besides E, the presence of nano-SiC particles could increase the overall order of reaction m+n and the frequency factor A, meanwhile, the amino silane coupling agent decreases these three parameters. [Copyright &y& Elsevier]

Direct coagulation casting via urease-catalyzed hydrolysis of urea in SiC suspension was studied at room temperature. The results demonstrate that high-solids-loaded SiC slurries with low viscosity can be prepared at pH 9.5–10.5. The urease-catalyzed decomposition of urea can be used to shift the pH and to increase the ionic strength of the SiC slurry. The pH value decreased with the increase of coagulation time. The optimal coagulation temperature is 50 °C for 62 vol.% SiC slurry. The strength of wet green body after 1 h of coagulation at room temperature is high enough for demolding and handling without damage in the wet green stage. [Copyright &y& Elsevier]

TiO2 prepared by the sol–gel method and adding 30 wt.% of polyvinylpyrrolidone (PVP) has been proved to be efficient in the photodegradation of methylene red under ultraviolet (UV) light. The same powder was also found to be photoactive under sunlight in this research. TiO2 powders with various contents of added PVP were prepared and characterized by XRD, diffuse reflectance spectroscopy (DRS), etc. It was found that the presence of PVP in the sol–gel process can reduce the transformation temperature from anatase to rutile phase and the crystallite size of TiO2. At the same time, a unique coexistence structure of the anatase and rutile phases was obtained in these materials. [Copyright &y& Elsevier]

Silica-doped nanocrystalline titania powders were prepared using the sol–gel technique. The influence of dopant concentration on the phase transition and grain growth was studied. Subsequently the sample was studied at a constant dopant concentration to investigate the effect of calcination temperature on the photoactivity of titania. It was found that 30SiO2/TiO2 (30 denotes the weight percent of SiO2) fired at 800 °C has a higher photoactivity than other samples with different silica content and different calcination temperature. The effect of addition of silica was to increase the photoactivity by suppressing the phase transformation of titania from anatase to rutile and forming oxygen vacancies in titania. [Copyright &y& Elsevier]

Photodoping as a nonvolatile and reversible method can be used to modify the carrier distribution at the heterojunction interface. Herein, we explore the 2D/3D van der Waals (vdW) graphene/silicon (G/Si) heterostructure in real time by terahertz (THz) emission spectroscopy. Photoinduced doping is introduced by a continuous wave laser, which leads to a screening effect to the built-in electric field at the interface. The resulting decrease in transient photocurrent reduces the THz emission amplitude from the G/Si heterostructure. The photoinduced doping effect suggests a 40% THz intrinsic modulation depth at external reverse bias. This work provides an effective way to actively control the THz emission process from the G/Si interface and paves the way for analyzing the interfacial process under photoinduced doping in vdW heterostructures. [ABSTRACT FROM AUTHOR]

We investigated the terahertz (THz) radiation mechanism of the layered tin sulfide (SnS2) crystal via THz emission spectroscopy. Under non-resonant excitation, THz generation from SnS2 is mainly due to the optical rectification effect, which is verified by the azimuthal angle, polarization angle, and pump fluence dependence of the THz signals. Further incident angle dependent THz signals suggest that the optical progress happened at the surface of SnS2 with both in-plane and out-of-plane photon-induced dipoles. This work puts forward THz emission spectroscopy as a noninvasive characterization tool for the in-plane and out-of-plane photon-induced dipoles in layered materials. [ABSTRACT FROM AUTHOR]

Inspired by the chiral structure from mode interaction, a chiral terahertz metamaterial and its complementary structure with the coexistence of asymmetric transmission and circular dichroism response are designed. The asymmetric transmission happens in the presence of electric and magnetic modes perpendicular to each other, resulting from intrinsic chirality under normal incidence. Circular dichroism exists in the presence of electric and magnetic modes parallel to each other under oblique incidence because of extrinsic chirality. Both asymmetric transmission and circular dichroism are enhanced by complementary structures, benefitting from the coupling between adjacent units. The maximum of chiral parameter κ can achieve 450, which is one hundred times higher than previously reported. The chiral response can be tuned by the incident angle and is sensitive to the environmental refractive index. The results highlight the potential applications of these metamaterials in chiral sensing and polarization transformation devices. [ABSTRACT FROM AUTHOR]

Background: Cancer‐specific autoantibodies found in serum of cancer patients have been characterized as potential predictors of the high risk of recurrence and treatment response. The objective of this study is to investigate the clinical utility of serum O‐6‐methylguanine‐DNA methyltransferase (MGMT) autoantibodies as novel biomarkers for prediction of recurrence and treatment response for glioma through MGMT peptides microarray. Methods: A total of 201 serum samples of glioma patients with various WHO grade and 311 serum samples of healthy donors were examined for the detection of MGMT autoantibodies by peptides microarray. The clinical value of MGMT autoantibodies was studied through univariable and multivariable analyses. Results: Autoantibodies to MGMT peptides were detected in sera from glioma patients and five highly responsive autoantibodies to peptides were identified in the glioma group. The positive rate of MGMT autoantibody to 20 peptides in glioma groups is compared with healthy individuals, the positive rate of MGMT‐02 (45%), MGMT‐04 (27%), MGMT‐07 (21%), MGMT‐10 (13%), and MGMT‐18 (24%) were significantly elevated in patients with glioma. MGMT autoantibody and its protein expression exhibited a significant correlation. The levels of MGMT autoantibodies decreased on the 30th day after operation, reaching preoperative levels, similar to those when tumor recurrence developed. Univariable and multivariable analyses revealed that the only preoperative autoantibodies to MGMT‐02 peptide were independently correlated with recurrence‐free survival. Preoperative seropositive patients were more likely than seronegative patients to have shorter recurrence times and to be resistant to chemoradiotherapy or chemotherapy with temozolomide. Conclusion: Monitoring the levels of preoperative serum autoantibodies to MGMT‐02 peptide was useful for predicting patients at high risk of recurrence and treatment response. [ABSTRACT FROM AUTHOR]

Giant plasmonic mode splitting has been observed in THz metamaterials due to the mediation by the Lorentz phonon dielectric material. This splitting mode is confirmed by the surface current distribution, indicating that plasmonic modes behave like dipole resonances, while the phonon mode behaves like multipole resonance due to coupling. The splitting of the plasmonic modes demonstrates an anti-crossing behavior with the change in Lorentz central frequency, which suggests that there is energy redistribution between plasmon and phonon modes. Similar to the Stark effect, the splitting frequency difference increases with the increasing direct current dielectric function. We also propose an interaction Hamiltonian to understand the physical mechanism of the plasmonic splitting. Furthermore, the splitting is convincible for small Lorentz dielectrics such as sugar and amino acid in the THz region, which could be used for biomolecular sensing applications. [ABSTRACT FROM AUTHOR]

Two-dimensional chirality induced polarization conversion and asymmetric transmission have great potential for polarization applications. We propose graphene-based planar chiral metamaterial and its complementary structure with dual functionality of both circular polarization conversion and asymmetric transmission in terahertz (THz) region. The conversion efficiency of chiral structure can reach up to 37.33/λ, which is comparable with three-dimensional chiral structure made of metal due to the unique optoelectronic properties of graphene. The transmission asymmetry of complementary chiral metamaterial originating from the high order plasmonic resonance can be tuned from 0.049% to 3.504% by changing Fermi energy, and the asymmetry can also be enhanced via geometrical optimization. This work raises the prospect of switchable, compact, and on-chip THz polarized devices with graphene materials. [ABSTRACT FROM AUTHOR]

Abstract: The coefficient of thermal expansion (CTE) and accumulated plastic strain of the pure aluminum matrix composite containing 50% SiC particles (Al/SiCp) during thermal cycling (within temperature range 298–573K) were investigated. The composite was produced by infiltrating liquid aluminum into a preform made by SiC particles with an average diameter of 14μm. Experiment results showed that the relationship between the CTE of Al/SiCp and temperature is nonlinear; CTE could reach a maximum value at about 530K. The theoretical accumulated plastic strain of Al/SiCp composites during thermal cycling has also been calculated and compared with the experimental results. [Copyright &y& Elsevier]

Abstract: The effect of temperature on surface charge properties and rheological behavior (like pH, viscosity and zeta potential) of an aqueous SiC suspension were studied. Temperature significantly affected the rheological behavior of the aqueous SiC suspension. The pH and zeta potential of the SiC suspension all decreased with the increasing of temperature. Steady rate sweep experiments showed an increase in viscosity with increasing temperature and the effect was enhanced with increasing solid loading. These effects are attributed to a destabilizing effect of temperature, derived from the dissolution of a thin SiO2 layer on the SiC surface. [Copyright &y& Elsevier]

Abstract: This work focuses on the optimization of the rheological properties of silicon suspensions by changing the concentration of a dispersant and the pH value of the dispersing medium. The zeta potential and rheological properties of silicon suspensions as a function of tetramethyl ammonium hydroxide (TMAH) concentration were carried out. The results show that the isoelectric point of the silicon particles was at pH 1.6. A silicon suspension with 46 vol.% particles displayed a minimum viscosity at pH 9.6. The results also show that TMAH is an efficient dispersant by enhancing the absolute value of the zeta potential of silicon particles. The optimum dosage of the dispersant was 0.4 wt.% of silicon particles. [Copyright &y& Elsevier]

The hydrolysis assisted solidification (HAS) process was used in the slurry forming of SiC green bodies. AlN powder was added to aqueous SiC slurry prior to shaping. The addition of small amount of AlN powder causes a dramatic increase in the suspension viscosity or even solidification in the case of highly loaded suspension. Green bodies were successfully produced. Measurements of the changes in viscosity, the pH and the zeta potential measurements were performed to evaluate the process. Effects of the addition of AlN and solidification temperature on the process and the ceramic suspension were followed. [Copyright &y& Elsevier]

Abstract: Needle-shaped and spherical titania particles were prepared with the addition of urea in the precursor solution by sol–gel method. Scanning electronic microscope (SEM), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) measurements were used to characterize the particles. The results show that the content of urea is the main factor that affects the morphology of the titania particles. The formation mechanism of the shaped titania particles is discussed. [Copyright &y& Elsevier]

Abstract: Pure aluminum matrix composite reinforced with a high volume fraction of silicon particles (Al/Sip) was fabricated by gas-pressured infiltration. The results of four point flexural strength tests show that Al/Sip has low flexural strength. The analysis of the fractograph reveals the fracture mechanism of Al/Sip. The fracture of Al/Sip is primarily dominated by the fracture of brittle silicon particles and the subsequent link up of damage through the matrix. The pre-existent microcracks in silicon particles that were made during the process of compacting will also lower the flexural strength of Al/Sip composite. The hybrid particle reinforced pure aluminum matrix composite (Al/Sip+SiCp) was fabricated in the same way. Results show the flexural strength can be improved by 11.3% compared with Al/Sip when 6 vol.% silicon particles are replaced by silicon carbide particles with the same volume fraction and size. The reason is that SiCp with higher fracture stress and higher elastic modulus can prevent the rapid expansion of cracks through the composite and lower the stress in silicon particles. [Copyright &y& Elsevier]

Tetramethyl ammonium hydroxide (TMAH) was used as dispersant for SiC aqueous suspension. The effects of dispersant concentration and pH on the rheological behavior of SiC aqueous suspension were studied. TMAH improves dispersion by increasing the negative zeta potential of SiC particles. The recommended amount of TMAH is 0.6 wt.% in order to obtain the minimum viscosity and the maximum negative zeta potential. The optimum dispersion occurs at pH 10. The dispersion mechanism by TMAH is discussed. [Copyright &y& Elsevier]

The kinetics of oxygen in- and out-diffusion in the crushed YBa2Cu3O7−δ single-crystal prepared by the top-seeded solution-growth (TSSG) were studied by thermogravimetry. By fitting these experimental curves, the chemical in-diffusion coefficient in the temperature range from 375 to 475°C were determined as on the order of 10−10cm2/s for the samples with oxygen deficiencies δ<0.1. The activation energy in the same samples was also determined as 1.04±0.10eV. The out-diffusion exhibited similar kinetics behavior as in the in-diffusion process at a fixed oxygen partial pressure. [Copyright &y& Elsevier]

Visible light responsive zinc ferrite doped titania photocatalyst (TiO2(ZnFe2O4)) was prepared by sol–gel method and was calcined at different temperatures. Diffuse reflectance spectroscopy (DRS) results show that the absorption edge of TiO2(ZnFe2O4) has moved to the visible spectrum range in comparison with the undoped titania. The photocatalytic experimental result demonstrates that TiO2(ZnFe2O4) powder can effectively photodegrade methyl orange (MO) under visible light irradiation. Effect of calcination temperature on the photocatalytic activity of TiO2(ZnFe2O4) was also investigated. Zeta potential measurements indicate that the isoelectric point (IEP) of the TiO2(ZnFe2O4) powder shifts to lower pH units with the increase of calcination temperature. Brunauer–Emmett–Teller (BET) surface area decreases with the rise of calcination temperature. It is concluded that the surface charge and BET surface area are the key factors for the higher photoactivity of zinc ferrite doped titania photocatalyst calcined at 400 °C. [Copyright &y& Elsevier]

Surface modification of SiC powder leached by deionized water, acid, and base leaching and the effect on the rheological behavior of concentrated aqueous SiC suspensions were investigated. The SiC powders were well dispersed irrespective of the surface treatment. However, the viscosity was affected by the surface treatment. The experimental results indicated that base leaching caused a lower viscosity. The reason of the leaching effect on viscosity was discussed. The influence of SiC oxidative thermal treatment was determined for SiC suspensions. It was found that calcination of the SiC powder was observed to result in partial oxidation of SiC to amorphous SiO2 and effectively reduced the viscosity of SiC suspensions. [Copyright &y& Elsevier]

• Mixed Bi 2 S 3 /MoS 2 heterostructure was prepared by liquid phase exfoliation. • Band-alignment of Bi 2 S 3 /MoS 2 heterostructure suggests the formation of Type III heterojunction. • Enhanced nonlinear saturable absorption was observed in Bi 2 S 3 /MoS 2 heterostructure films. • The enhancement is due to the interlayer electron transition in type-III heterostructure. Nonlinear optical properties of van der Waals heterostructures (vdWHs) are important for new-generation nanophotonics and integrating photonics. However, type-III vdWHs are extremely neglected in the nonlinear optical research. Herein, MoS 2 and Bi 2 S 3 are proposed to form mixed vdWHs by liquid-phase exfoliation method combined with a vacuum filtration technique. Type-III vdWHs Bi 2 S 3 /MoS 2 is identified and the band alignment is confirmed by XPS and UV–Vis absorption spectra successfully. The nonlinear responses of the vdWHs nanofilms given by Z-scan method indicate that the saturable absorption response of Bi 2 S 3 /MoS 2 is enhanced obviously compared with that of pure Bi 2 S 3 and MoS 2. Furthermore, an energy level model is proposed and the results suggest that the quick interlayer electron transition from the conduction band of Bi 2 S 3 to the valence band of MoS 2 plays a crucial role for the observed enhancement. This interlayer electron transition is driven by an oriented built-in electric field due to the band-to-band tunneling transition in type-III vdWHs. Our results make clear the mechanism of type-III heterostructures in nonlinear optical process and pave the way for applications of type-III vdWHs in nonlinear optoelectronics. [ABSTRACT FROM AUTHOR]

Surface oxidation was easily formed at the edge of WS 2 , thus leading to charge transfer from WS 2 to WO 3. • Size-separation of WS 2 nanosheets was prepared using liquid phase exfoliation. • Surface oxidation defect of WS 2 was formed easily by smaller size. • Size-dependent nonlinear optical Absorption in WS 2 was observed. • Charge transfer at interface is used to explain the tunable nonlinear absorption. Controlling nanosheet size and understanding size-dependent surface oxidation are of quite importance for the nonlinear optical properties of two-dimensional materials. Herein, size-separation of WS 2 nanosheets was prepared successfully using liquid phase exfoliation and a gradient centrifugation method. We confirmed the higher surface oxidation with the decrease of nanosheet size by both high-resolution X-ray photoelectron spectroscopy and Raman spectroscopy. To investigate the effect of size-dependent surface oxidation on nonlinear optical properties in WS 2 , Z-scan technique equipped with 800 nm femtosecond laser was used. We observed the conversion between saturable absorption and reverse saturable absorption in WS 2 dispersions as well as the decrease of saturable absorption in WS 2 films due to the increase of reverse saturable absorption contribution of WO 3. Energy-level model based on type II WS 2 /WO 3 heterostructure was put forth to understand nonlinear optical absorption of the oxidized WS 2. The results show that charge transportation from WS 2 to WO 3 increases the reverse saturable absorption contribution in WO 3 while decreases the saturable absorption in WS 2. The results pave the way to design desirable nonlinear optical devices by controlling size with different level of surface oxidation. [ABSTRACT FROM AUTHOR]

Background: KLF5 is a member of the Kruppel-like factor, subfamily of zinc finger proteins that are involved in cancers. KLF5 functions as a transcription factor and regulates the diverse protein-coding genes (PCGs) in colorectal cancer (CRC). However, the long non-coding RNAs (lncRNAs) regulated by KLF5 in CRC are currently unknown. Methods: In this study, we first designed a computational pipeline to determine the PCG and lncRNA targets of KLF5 in CRC. Then we analyzed the motif pattern of the binding regions for the lncRNA targets. The regulatory co-factors of KLF5 were then searched for through bioinformatics analysis. We also constructed a regulatory network for KLF5 and annotated its functions. Finally, one of the KLF5 lncRNA targets, SNHG12, was selected to further explore its expression pattern and functions in CRC. Results: We were able to identify 19 lncRNA targets of KLF5 and found that the motifs of the lncRNA binding sites were GC-enriched. Next, we pinpointed the transcription factors AR and HSF1 as the regulatory co-factors of KLF5 through bioinformatics analysis. Then, through the analysis of the regulatory network, we found that KLF5 may be involved in DNA replication, DNA repair, and the cell cycle. Furthermore, in the cell cycle module, the SNHG12 up-regulating expression pattern was verified in the CRC cell lines and tissues, associating it to CRC invasion and distal metastasis. This indicates that SNHG12 may play a critical part in CRC tumorigenesis and progression. Additionally, expression of SNHG12 was found to be down-regulated in CRC cell lines when KLF5 expression was knocked-down by siRNA; and a strong correlation was observed between the expression levels of SNHG12 and KLF5, further alluding to their regulatory relationship. Conclusions: In conclusion, the network analysis of KLF5 targets indicates that SNHG12 may be a significant lncRNA in CRC. [ABSTRACT FROM AUTHOR]

Chirality, as the core code of life forms, connects the ultimate secret of life and universe evolution. In article number 1900398, Changji Liu and co-workers propose an intrinsic chiral metamaterial and its complementary structures with coexistence of circular asymmetric transmission and circular dichroism in the THz region. The analysis reveals the chirality in metamaterials mainly comes from mode interaction and can be tuned by the incident angle. [Extracted from the article]