Epitaxial Strain Enhanced Ferroelectric Polarization toward a Giant Tunneling Electroresistance.

A substantial ferroelectric polarization is the key for designing high-performance ferroelectric nonvolatile memories. As a promising candidate system, the BaTiO3/La0.67Sr0.33MnO3 (BTO/LSMO) ferroelectric/ferromagnetic heterostructure has attracted a lot of attention thanks to the merits of high Curie temperature, large spin polarization, and low ferroelectric coercivity. Nevertheless, the BTO/LSMO heterostructure suffers from a moderate FE polarization, primarily due to the quick film-thickness-driven strain relaxation. In response to this challenge, we propose an approach for enhancing the FE properties of BTO films by using a Sr3Al2O6 (SAO) buffering layer to mitigate the interfacial strain relaxation. The continuously tunable strain allows us to illustrate the linear dependence of polarization on epitaxial strain with a large strain-sensitive coefficient of ∼27 µC/cm2 per percent strain. This results in a giant polarization of ∼80 µC/cm2 on the BTO/LSMO interface. Leveraging this large polarization, we achieved a giant tunneling electroresistance (TER) of ∼105 in SAO-buffered Pt/BTO/LSMO ferroelectric tunnel junctions (FTJs). Our research uncovers the fundamental interplay between strain, polarization magnitude, and device performance, such as on/off ratio, thereby advancing the potential of FTJs for next-generation information storage applications.

Large Polarization Near 50 µC/cm2 in a Single Unit Cell Layer SrTiO3.

The generally nonpolar SrTiO3 has attracted more attention recently because of its possibly induced novel polar states and related paraelectric-ferroelectric phase transitions. By using controlled pulsed laser deposition, high-quality, ultrathin, and strained SrTiO3 layers were obtained. Here, transmission electron microscopy and theoretical simulations have unveiled highly polar states in SrTiO3 films even down to one unit cell at room temperature, which were stabilized in the PbTiO3/SrTiO3/PbTiO3 sandwich structures by in-plane tensile strain and interfacial coupling, as evidenced by large tetragonality (∼1.05), notable polar ion displacement (0.019 nm), and thus ultrahigh spontaneous polarization (up to ∼50 µC/cm2). These values are nearly comparable to those of the strong ferroelectrics as the PbZrxTi1-xO3 family. Our findings provide an effective and practical approach for integrating large strain states into oxide films and inducing polarization in nonpolar materials, which may broaden the functionality of nonpolar oxides and pave the way for the discovery of new electronic materials.

Enhanced Pitting Corrosion Resistance of Nanostructured AISI 304 Stainless Steel via Pipe Inner Surface Grinding Treatment.

By means of a pipe's inner surface grinding, a single-phase nanostructured austenite was formed on the surface of an AISI 304 stainless steel. The electrochemical corrosion behavior was compared with a coarse-grained counterpart of identical surface roughness. Experimental results show that the nanostructured austenite shows a higher pitting potential and a wider passivation interval than those of its coarse-grained counterpart. The enhanced corrosion resistance was attributed to the fast diffusion of Cr within the nanostructure and, hence, the formation of a thicker passive film to efficiently protect the surface against the ion attack. This work provides insights into a simple processing method to improve the surface strength and pitting resistance of stainless steel.

Polar Magnetism Above 600 K with High Adaptability in Perovskite Oxides.

High magnetic order temperature, sustainable polar insulating state, and tolerance to device integrations are substantial advantages for applications in next-generation spintronics. However, engineering such functionality in a single-phase system remains a challenge owing to the contradicted chemical and electronic requirements for polar nature and magnetism, especially with an ordering state highly above room temperature. Perovskite-related oxides with unique flexibility allow electron-unpaired subsystems to merge into the polar lattice to induce magnetic interactions, combined with their inherent asymmetry, thereby promising polar magnet design. Herein, by atomic-level composition assembly, a family of Ti/Fe co-occupied perovskite oxide films Pb(Ti1-x,Fex)O3 (PFT(x)) with a Ruddlesden-Popper superstructure are successfully synthesized on several different substrates, demonstrating exceptional adaptability to different integration conditions. Furthermore, second-harmonic generation measurements convince the symmetry-breaking polar character. Notably, a ferromagnetic ground state up to 600 K and a steady insulating state far beyond room temperature were achieved simultaneously in these films. This strategy of constructing layered modular superlattices in perovskite oxides could be extended to other strongly correlated systems for triggering nontrivial quantum physical phenomena.

Thickness-Dependent Polar Domain Evolution in Strained, Ultrathin PbTiO3 Films.

Ferroelectric ultrathin films have great potential in electronic devices and device miniaturization with the innovation of technology. In the process of product commercialization, understanding the domain evolution and topological properties of ferroelectrics is a prerequisite for high-density storage devices. In this work, a series of ultrathin PbTiO3 (PTO) films with varying thicknesses were deposited on cubic KTaO3 substrates by pulsed laser deposition and were researched by Cs-corrected scanning transmission electron microscopy (STEM), reciprocal space mapping (RSM), and piezoresponse force microscopy (PFM). RSM experiments indicate the existence of a/c domains and show that the lattice constant varies continuously, which is further confirmed by atomic-scale STEM imaging. Diffraction contrast analysis clarifies that with the decrease in PTO film thickness, the critical thickness for the formation of a/c domains could be missing. When the thickness of PTO films is less than 6 nm, the domain configurations in the ultrathin PTO films are the coexistence of a/c domains and bowl-like topological structures, where the latter ones were identified as convergent and divergent types of meron. In addition, abundant 90° charged domain walls in these ultrathin PTO films were identified. PFM studies reveal clear ferroelectric properties for these ultrathin PTO films. These results may shed light on further understanding the domain evolution and topological properties in ultrathin ferroelectric PTO films.

Development of a 3D Printed Lung Model Made of Synthetic Materials for Simulation.

BACKGROUND: Considering the complexity of lung structures and the difficulty of thoracoscopic surgery, simulation-based training is of paramount importance for junior surgeons. Here, we aim to design a high-fidelity lung model through utilizing the three-dimensional (3D) printing technology combined with synthetic materials to mimic the real human lung. METHODS: The 3D printed lung model was manufactured based on the computed tomography images of a randomly selected male patient. Synthetic materials were used for the construction of lung parenchyma, blood vessels, and bronchi. Then, the model was assessed in terms of its visual, tactile, and operational features by participants (the senior surgeons, junior surgeons, and medical students), who were asked to complete the specially designed survey-questionnaires. RESULTS: A 3D printed model of the right lung made of synthetic materials was successfully fabricated. Thirty subjects participated in our study (10 senior surgeons, 10 junior surgeons, and 10 medical students). The average visual evaluation scores for senior surgeons, junior surgeons, and medical students were 3.97 ± 0.61, 4.56 ± 0.58, 4.76 ± 0.49, respectively. The average tactile evaluation scores were 3.40 ± 0.50, 4.13 ± 0.68, 4.00 ± 0.64, respectively. The average operation evaluation scores were 3.33 ± 0.83, 3.93 ± 0.66, 4.03 ± 0.66, respectively. Significant lower scores were obtained in the group of the senior surgeons compared with the other two groups. CONCLUSION: A high level of fidelity was exhibited in our 3D printed lung model and it could be applied as a promising simulator for the surgical training in the future.

Fabrication of Low Roughness Gradient Nanostructured Inner Surface on an AISI 304 Stainless Steel Pipe via Ultra-Sonic Rolling Treatment (USRT).

Gradient nanostructure (GNS) has drawn great attention, owing to the unique deformation and properties that are superior to nanostructure with uniform scale. GNS is commonly fabricated via surface plastic deformation with small tips (of balls or shots) so as to produce high deformation to refine the coarse grains, but unfortunately it suffers from the deterioration of surface quality which is hard to guarantee the reliable service. Although there are mirror-finishing techniques that can greatly enhance the surface quality, the induced slight deformation is commonly unable to produce GNS of reasonable thickness. Here, we propose a method to fabricate a GNS surface layer with a substantially enhanced surface quality via ultra-sonic rolling treatment (USRT), namely, surface rolling with a roller vibrated at a frequency of 20,000 Hz. It is found that 4-pass USRT is able to produce 20-30 µm thick GNS on AISI 304 stainless steel pipe inner surface, wherein the surface quality is enhanced by one order of magnitude from the starting Ra = 3.92 µm to 0.19 µm. Processing by a roller with a high-frequency vibration is necessary for both good surface quality and the effective accumulation of heavy deformation on the surface. The flattening mechanism as well as the microstructural evolution from millimeter- to nanometer-scale for AISI 304 stainless steel is discussed.

Zero Lithium Miscibility Gap Enables High-Rate Equimolar Li(Mn,Fe)PO4 Solid Solution.

Forming olivine-structured Li(Mn,Fe)PO4 solid solution is theoretically a feasible way to improve the energy density of the solid solutions for lithium ion batteries. However, the Jahn-Teller active Mn3+ in the solid solution restricts their energy density and rate performance. Here, as demonstrated by operando X-ray diffraction, we show that equimolar LiMn0.5Fe0.5PO4 solid solution nanocrystals undergo a single-phase transition during the whole (de)lithiation process, with a feature of zero lithium miscibility gap, which endows the nanocrystals with excellent electrochemical properties. Specifically, the energy density of LiMn0.5Fe0.5PO4 reaches 625 Wh kg-1, which is 16% higher than that of LiFePO4. Moreover, the high-performance LiMn0.5Fe0.5PO4 nanocrystals are prepared by a microwave-assisted hydrothermal synthesis in pure water.

Bi-Cation Electrolyte for a 1.7 V Aqueous Zn Ion Battery.

Rechargeable aqueous zinc-ion batteries (ZIBs) are receiving increased attention because of their high safety and low cost. However, their practical application is plagued by their low energy density as a result of low output voltage and a narrow voltage window of aqueous electrolytes. Here, we explored a ZIB with a wider potential window using bication (1 M Al(CF3SO3)3/1 M Zn(CF3SO3)2) as the electrolyte and α-MnO2 as the cathode, obtaining a discharge voltage of 1.7 V, ∼0.3 V higher than the value reported earlier. The resultant cell delivers a record high energy density of 448 W h kg-1 (based on MnO2 mass) and retains 100% capacity over 1000 cycles. The ion-storage mechanism and the role of Al3+ in enlarging the output voltage were elucidated. This research indicates the important role of using bications in improving the electrochemical performance of aqueous ZIBs, opening a new way to increase the energy density of aqueous energy storage devices.

In Situ Passivation on Rear Perovskite Interface for Efficient and Stable Perovskite Solar Cells.

Despite the rocketing rise in power conversion efficiencies (PCEs), the performance of perovskite solar cells (PSCs) is still limited by the carrier transfer loss at the interface between perovskite (PVSK) absorbers and charge transporting layers. Here, we propose a novel in situ passivation strategy by using [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) to improve the charge dynamics at the rear PVSK/CTL interface in the n-i-p structure device. A pre-deposited PCBM-doped PbI2 layer is redissolved during PVSK deposition in our routine, establishing a bottom-up PCBM gradient that is facile for charge extraction. Meanwhile, the surface defects are in situ-passivated via PCBM-PVSK interaction, which substantially suppresses the trap-assisted recombination at the rear interface. Due to the synergistic effect of charge-extraction promotion and trap passivation, the fabricated PSCs deliver a champion PCE of 20.10% with attenuated hysteresis and improved long-term stability, much higher than the 18.39% of the reference devices. Our work demonstrates a promising interfacial engineering strategy for further improving the performance of PSCs.

Fibulin-3 Has Anti-Tumorigenic Activities in Cutaneous Squamous Cell Carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common skin cancer. Several previous studies have shown that fibulin-3 participates in the occurrence and development of various tumors; however, its role in cSCC remains unknown. In the present study, we observed that the expression of fibulin-3 was downregulated in cSCC tissues compared with normal skin tissues, which was due to fibulin-3 promoter methylation. In vitro, knockdown of fibulin-3 in cSCC cell lines A431 and SCL-1 cells promoted cell proliferation, protected cells against apoptosis and enhanced migration and invasion abilities. Conversely, overexpression of fibulin-3 inhibited cell proliferation by promoting growth arrest during the G1/S phase transition, induced apoptosis, and reduced migration and invasion abilities. These anticarcinogenic effects of fibulin-3 were associated with inhibition of the AKT signaling pathway. Through a mouse xenograft model, we found that fibulin-3 overexpression inhibited the cSCC tumor growth in vivo. Our results suggest that fibulin-3 has anti-tumorigenic activities in cSCC. Downregulation of fibulin-3 is involved in cSCC development and it may serve as a novel therapeutic target of this disease.

Microstructure of FeCrAl Thin Film Composed of Nanocrystals Deposited on Zr Alloy and Their Corrosion Behavior Under Water Steam Atmosphere.

Zr alloy cladding materials is the core component of the nuclear reactor, the safety of cladding materials is very important. Zr alloy cladding materials is inclined to react with water under high temperature. The products are ZrO2 and H2. The mechanical property of Zr alloy decreases promptly. In order to protect Zr alloy from high temperature water, FeCrAl thin film layer was deposited on Zr alloy surface. The structure, chemical composition, surface elemental valence and morphology of FeCrAl thin film layer were carefully investigated by XRD, EDS, XPS, and SEM. After the test of corrosion experiment, deposition of FeCrAl thin film layer on Zr alloy surface showed the better corrosion property than Zr alloy under high temperature water steam atmosphere. The corrosion rate of Zr alloy with deposited FeCrAl thin film was 1.5 times lower than that of Zr alloy. The deposition of FeCrAl thin film layer on Zr alloy is an efficient approach to improve the corrosion property.

Cornulin Is Induced in Psoriasis Lesions and Promotes Keratinocyte Proliferation via Phosphoinositide 3-Kinase/Akt Pathways.

Psoriasis is a chronic inflammatory skin disease characterized by abnormal proliferation of epidermal keratinocytes and infiltration of inflammatory cells. CRNN is a major component of the cornified cell envelope and implicated in several epithelial malignancies. Here, we show that CRNN expression was increased in the lesioned epidermis from the patients with psoriasis vulgaris and skin lesions from the imiquimod (IMQ)-treated mice. Expression of CRNN in cultured keratinocytes (HEKa and HaCaT) was also induced by M5, a mixture of five pro-inflammatory cytokines (i.e., IL-17A, IL-22, IL-1α, oncostatin M, and TNF-α). Lentiviral expression of CRNN increased cell proliferation by inducing cyclin D1. Conversely, knockdown of CRNN by small interfering RNA suppressed G1/S transition and attenuated the M5-induced proliferation. In addition, CRNN overexpression increased the phosphorylation and activation of phosphoinositide 3-kinase and Akt. Inactivation of the phosphoinositide 3-kinase and Akt pathways using small interfering RNA or selective inhibitors (LY294002 and MK2206) reduced the proliferative effects of CRNN. Furthermore, topical use of anti-psoriatic calcipotriol effectively decreased expression of CRNN, inhibited the Akt activation and improved the IMQ-stimulated psoriasis-like pathologies. Taken together, these results suggest that induced expression of CRNN may contribute to the pathogenesis of psoriasis.

Yes-associated protein promotes the abnormal proliferation of psoriatic keratinocytes via an amphiregulin dependent pathway.

Psoriasis is a chronic inflammatory skin disease with high morbidity, poor treatment methods and high rates of relapse. Keratinocyte hyperproliferation and shortened cell cycles are important pathophysiological features of psoriasis. As a known oncogene, Yes-associated protein (YAP) plays a role in promoting cell proliferation and inhibiting cell apoptosis; however, whether YAP is involved in the pathogenesis of psoriasis remains to be determined. Amphiregulin (AREG), a transcriptional target of YAP, was found to be upregulated in psoriasis, and overexpression of AREG promoted keratinocyte proliferation. In the present study, immunohistochemistry showed that YAP expression was elevated in the skin of psoriasis patients and in the Imiquimod (IMQ) mouse model of psoriasis. Knockdown of YAP in HaCaT cells inhibited cell proliferation, caused cell cycle arrest in G0/G1 phase and promoted apoptosis. These changes in YAP-knockdown HaCaT cells were related to changes in AREG expression. We concluded that YAP may play an important role in the regulation of abnormal keratinocyte proliferation via an AREG-dependent pathway and that YAP could be a new target in the treatment of psoriasis.

Antimicrobial peptide LL-37 promotes the viability and invasion of skin squamous cell carcinoma by upregulating YB-1.

Antimicrobial peptide LL-37 serves a function in the host defense against microbial invasion, and also regulates cell proliferation, immune activity and angiogenesis. Previous studies have reported that LL-37 participates in the development of numerous tumour types, such as ovarian cancer, lung cancer, melanoma and breast cancer. However, the function of LL-37 in the development of skin squamous cell carcinoma (SCC) has not yet been fully elucidated. The aim of the current study was to investigate how LL-37 promotes the expression of Y-box binding protein 1 (YB-1) in SCC. Short interfering RNA (siRNA) was used to inhibit the expression of YB-1, and in vitro MTT and Transwell migration assays were used to evaluate the effect of reduced YB-1 on the viability and invasion of A431 cells. A431 cells were stimulated with LL-37, and quantitative polymerase chain reaction, immunofluorescence and western blot analyses were used to detect changes in YB-1 expression. Mitogen-activated protein kinase kinase, mitogen-activated protein kinase and nuclear factor (NF)-κB signaling pathway inhibitors were also used to evaluate the mechanism of LL-37-induced YB-1 protein expression. It was found that YB-1 expression was increased in SCC tissue compared with normal tissue. Inhibiting YB-1 expression using siRNA significantly reduced the viability and suppressed the invasion of tumour cells (P<0.05 for both). LL-37 treatment at 0.05 µg/ml for 24 or 48 h significantly promoted YB-1 protein expression (P<0.05), and this was dependent on the NF-κB signaling pathway. In conclusion, the current study demonstrated that by upregulating the expression of YB-1, LL-37 can promote the occurrence and development of SCC, and this process involves the NF-κB signaling pathway.

Antimicrobial peptide LL-37 promotes the proliferation and invasion of skin squamous cell carcinoma by upregulating DNA-binding protein A.

The antimicrobial peptide LL-37 not only contributes to the host defence against microbial invasion but also regulates immune activity, angiogenesis and cell proliferation. Studies have shown that LL-37 participates in the development of a variety of tumours, such as lung cancer, ovarian cancer, breast cancer and melanoma. However, the role of LL-37 in the development of skin squamous cell carcinoma (SCC) is not clear. The present study used immunohistochemistry to confirm that the expression of human DNA-binding protein A (dbpA) was increased in SCC tissues. After stimulating SCC A341 cells, LL-37 was shown promote the proliferation, migration and invasion of these malignant cells. LL-37 also promoted the upregulation of dbpA mRNA and protein expression. In addition, after using small interfering RNA to silence the normal dbpA expression in these malignant cells, the proliferation and invasion of the tumor cells were significantly reduced. When the NF-κB inhibitor PDTC was used to inhibit the process of LL-37-stimulated cells, it was found that the original upregulated expression of dbpA was downregulated. Overall, the present demonstrated that by upregulating the expression of dbpA, LL-37 can promote the proliferation and invasion of tumour cells, and that this process depends on the NF-κB signalling pathway.

Yes-Associated Protein Contributes to the Development of Human Cutaneous Squamous Cell Carcinoma via Activation of RAS.

Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin malignant tumors with an increasing incidence. Studies have shown that Yes-associated protein (YAP) participates in the development of a variety of tumors as an oncogene, but to our knowledge its role in cSCC has not been reported. In this study, we used immunohistochemistry to show that YAP expression was elevated in cSCC samples of different stages versus in normal skin and that it was well correlated with the progression of the disease. Down-regulation of YAP in cSCC cell lines A431 and SCL-1 inhibited cell proliferation by inducing growth arrest during the G1/S phase transition, promoted apoptosis, and reduced invasion and migration abilities in vitro. Conversely, overexpression of YAP promoted cell proliferation and protected cells against basal and chemotherapy-induced apoptosis. These oncogenic effects of YAP were associated with activation of the RAS protein and its downstream AKT and ERK. Using a mouse xenograft model, we further showed that YAP depletion inhibited cSCC tumor growth in vivo. Our results suggested that YAP is involved in the carcinogenesis and development of cSCC and that it may serve as a biomarker or therapeutic target of this disease.

Association between interleukin-10-3575T>A (rs1800890) polymorphism and cancer risk.

BACKGROUND: Previous studies investigated the associations of interleukin-10 (IL-10) polymorphisms with different types of cancer, indicating an influence on cancer risk. IL-10-3575T>A (rs1800890) has been studied concerning a potential implication in terms of some cancer site risks, but the results from single studies are contradictory. METHODS: Eligible articles were identified by a search of the PubMed, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) databases until November 30, 2014. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the cancer risk by cancer sites, ethnicity, and other study features. RESULTS: We identified 15 published studies to research the link of the IL-10-3575T>A polymorphism with cancer risk. Our meta-analysis indicated that the IL-10-3575T>A polymorphism has a significant association with decreased melanoma risk in the heterozygote model (OR=0.67, 95% CI=0.49-0.92, p=0.02) and dominant model (OR=0.70, 95% CI=0.52-0.95, p=0.01), but increased diffuse large B-cell lymphoma (DLBCL) risk in all the different genetic models. CONCLUSION: Our analysis suggests that the IL-10-3575T>A mutation may associate with melanoma and DLBCL and exert a differential effect in different cancer sites. However, other factors may influence the association, and large-scale multicenter with adequate methodological quality studies are needed to confirm the impact on cancer susceptibility.

A novel dynamic cardiac simulator utilizing pneumatic artificial muscle.

With the development of methods and skills of minimally invasive surgeries, equipments for doctors' training and practicing are in high demands. Especially for the cardiovascular surgeries, operators are requested to be familiar with the surgical environment of a beating heart. In this paper, we present a new dynamic cardiac simulator utilizing pneumatic artificial muscle to realize heartbeat. It's an artificial left ventricular of which the inner chamber is made of thermoplastic elastomers (TPE) with an anatomical structure of the real human heart. It is covered by another layer of material forming the artificial muscle which actuates the systole and diastole uniformly and omnidirectionally as the cardiac muscle does. Preliminary experiments were conducted to evaluate the performance of the simulator. The results indicated that the pressure at the terminal of the aorta could be controlled within the range of normal human systolic pressure, which quantitatively validated the new actuating mode of the heart-beating is effective.

[Effect of occupational commitment on job burnout of traditional Chinese medicine doctors].

OBJECTIVE: To investigate the status of job burnout in traditional Chinese medicine (TCM) doctors and explore the effect of occupational commitment on job burnout. METHODS: A test of occupational commitment and job burnout was carried out in 507 TCM doctors with occupational commitment questionnaire and Maslach Burnout Inventory-Human Services Survey (MBI-HSS). RESULTS: The age group of < 30 years scored lowest (2.352 +/- 0.660) in personal accomplishment compared with 30 years old group and 40 years old group [(2.136 +/- 0.704) and (2.127 +/- 0.628) respectively] (P < 0.01). The score of emotional exhaustion and depersonalization increased with educational levels. There was significantly negative correlation between job burnout and occupational commitment (P < 0.01). Occupational commitment had significant effect on job burnout (P < 0.01). Occupational trouble commitment was a major predictor for emotional exhaustion (P < 0.01). Professional self-efficacy commitment was a major predictor for depersonalization (P < 0.01). Affective commitment was a major predictor for personal accomplishment (P < 0.01). CONCLUSION: Occupational commitment is a good predictor for job burnout. Improving occupational commitment is an important measure to prevent job burnout.