Effects of the temperature, strain rate, and loading conditions on the deformation behaviors and mechanical properties of the Ni/Ni3Al superalloy.

Using the molecular dynamics method, we comprehensively studied the effects of temperature, strain rate, and loading conditions on the deformation behaviors and the mechanical properties of the Ni/Ni3Al superalloy. Our investigation revealed that, an increase of the deformation temperature led to a significant improvement of plastic deformation capacity of the system, but the tensile strength and elastic modulus decreased. And the tensile strength and plastic deformation capacity of the system drastically increased with the strain rate. At high deformation temperature and strain rate, the loading conditions had a large effect on the deformation behaviors and the mechanical properties of the system. The difference of the mechanical properties of the system was mainly due to the different deformation mechanism of the system under different deformation temperature, strain rate and loading conditions. Our study offered a theoretical framework for explaining the difference of the mechanical properties for the Ni/Ni3Al superalloy at different service conditions.

A theoretical study of surface lithium effects on the [111] SiC nanowires as anode materials.

CONTEXT: Silicon carbide nanowires (SiCNWs) are considered a promising alternative material for application in lithium-ion batteries, with researchers striving to develop new electrode materials that exhibit high capacity and high charge/discharge rate performance. To gain a deeper understanding of the application of SiCNWs in semiconductor material science and energy supply fields, we investigated the effects of nanoscale and surface lithiation on the electrical and mechanical properties of SiCNWs grown along the [111] direction. First-principles calculation was used to study their geometries, electronic structures, and associated electrochemical properties. Herein, we considered SiCNWs with full hydrogen passivation, full lithium passivation, and mixed passivation at different sizes. The formation energy indicates that the stability of SiCNWs increases with the increasing diameter, and the surface-lithiated SiC nanowires (Li-SiCNWs) are found to be energetically stable. The mixed passivated SiCNWs exhibit the properties of indirect band gap with the increase of lithium atoms on the surface, while the fully lithium passivated nanowires exhibit metallic behavior. Charge analysis shows that a portion of the electrons on the lithium atoms are transferred to the surface atoms of the nanowires and electrons prefer to cluster more near the C atoms. Additionally, Li-SiCNWs still have good mechanical resistance during the lithiation process. The stable open-circuit voltage range and theoretical capacity of these SiCNWs indicate their suitability as anode materials. METHOD: In this study, Materials Studio 8.0 was used to construct the models of the SiCNWs. And all the density functional theory (DFT) calculations were performed by the Vienna ab initio Simulation Package (VASP). The self-consistent field calculations are performed over a Monkhorst-Pack net of 1 × 1 × 6 k-points. The energy convergence criteria for the self-consistent field calculation were set to 10-5 eV/atom with a cutoff energy of 400 eV.

Effects of crack-γ/γ' interface relative distributions on the deformation and crack growth behaviors of a nickel-based superalloy.

Using the molecular dynamics (MD) method, we investigated the effects of crack distributions on the deformation and crack growth of a nickel (Ni)-based superalloy. The results indicated that as the distance between two cracks increased, both tensile strength and plasticity decreased, while the crack growth rate significantly increased. In systems with short crack distances, strong interactions occurred between the dislocations that emitted from two cracks and the γ/γ' interface mismatched dislocation network. These interactions led to an overlap in the plastic zones ahead of the crack tips at the γ/γ' interface, which resulted in significant passivation at the front and middle regions of the cracks. Consequently, the two cracks merged in the X-direction to form a wide crack. The cracks coalescence consumed a lot of external deformation work, resulting in the highest tensile strength and plasticity. In this study, we proposed a potential approach to simultaneously enhance the strength and plasticity of multidefect systems, providing a theoretical basis for explaining deformation mechanisms and crack growth in these systems.

Molecular Dynamics Simulation on Solidification Microstructure and Tensile Properties of Cu/SiC Composites.

The shape of ceramic particles is one of the factors affecting the properties of metal matrix composites. Exploring the mechanism of ceramic particles affecting the cooling mechanical behavior and microstructure of composites provides a simulation basis for the design of high-performance composites. In this study, molecular dynamics methods are used for investigating the microstructure evolution mechanism in Cu/SiC composites containing SiC particles of different shapes during the rapid solidification process and evaluating the mechanical properties after cooling. The results show that the spherical SiC composites demonstrate the highest degree of local ordering after cooling. The more ordered the formation is of face-centered-cubic and hexagonal-close-packed structures, the better the crystallization is of the final composite and the less the number of stacking faults. Finally, the results of uniaxial tensile in three different directions after solidification showed that the composite containing spherical SiC particles demonstrated the best mechanical properties. The findings of this study provide a reference for understanding the preparation of Cu/SiC composites with different shapes of SiC particles as well as their microstructure and mechanical properties and provide a new idea for the experimental and theoretical research of Cu/SiC metal matrix composites.

Equibiaxial strain regulates the electronic structure and mechanical, piezoelectric, and thermal transport properties of the 2H-phase monolayers CrX2 (X = S, Se, Te).

A superior piezoelectric coefficient and diminutive lattice thermal conductivity are advantageous for the application of a two-dimensional semiconductor in piezoelectric and thermoelectric devices, whereas an imperfect piezoelectric coefficient and large lattice thermal conductivity limit the practical application of the material. In this study, we investigate how the equibiaxial strain regulates the electronic structure, and mechanical, piezoelectric, and thermal transport properties. Tensile strain can deduce the bandgap of the monolayer CrX2 (X = S, Se, Te), whereas compressive strain has an opposite effect. Additionally, the transition from a semiconductor to a metal state and the transition between direct and indirect band gaps will occur at appropriate strain values, so the electronic structure can be effectively regulated. The reason is the different sensitivities of the energy corresponding to K and Γ on the valence band to the strain due to the changes in different orbital overlaps. The tensile strain can effectively improve the flexibility of monolayers CrX2, which provides a possibility for the application of flexible electronic devices. Furthermore, the tensile strain can improve the piezoelectric strain coefficient of monolayers CrX2. Using Slacks formulation, we calculate the lattice thermal conductivity, and the tensile biaxial strain can reduce the lattice thermal conductivity. Our research provides a strategy to enhance the piezoelectric and flexible electronic applications and decrease the lattice thermal conductivity, which can benefit the thermoelectric applications.

Genome-wide DNA methylation analysis identifies potent CpG signature for temzolomide response in non-G-CIMP glioblastomas with unmethylated MGMT promoter: MGMT-dependent roles of GPR81.

PURPOSES: To identify potent DNA methylation candidates that could predict response to temozolomide (TMZ) in glioblastomas (GBMs) that do not have glioma-CpGs island methylator phenotype (G-CIMP) but have an unmethylated promoter of O-6-methylguanine-DNA methyltransferase (unMGMT). METHODS: The discovery-validation approach was planned incorporating a series of G-CIMP-/unMGMT GBM cohorts with DNA methylation microarray data and clinical information, to construct multi-CpG prediction models. Different bioinformatic and experimental analyses were performed for biological exploration. RESULTS: By analyzing discovery sets with radiotherapy (RT) plus TMZ versus RT alone, we identified a panel of 64 TMZ efficacy-related CpGs, from which a 10-CpG risk signature was further constructed. Both the 64-CpG panel and the 10-CpG risk signature were validated showing significant correlations with overall survival of G-CIMP-/unMGMT GBMs when treated with RT/TMZ, rather than RT alone. The 10-CpG risk signature was further observed for aiding TMZ choice by distinguishing differential outcomes to RT/TMZ versus RT within each risk subgroup. Functional studies on GPR81, the gene harboring one of the 10 CpGs, indicated its distinct impacts on TMZ resistance in GBM cells, which may be dependent on the status of MGMT expression. CONCLUSIONS: The 64 TMZ efficacy-related CpGs and in particular the 10-CpG risk signature may serve as promising predictive biomarker candidates for guiding optimal usage of TMZ in G-CIMP-/unMGMT GBMs.

Lymph node and bone metastasis of pulmonary intestinal adenocarcinoma: A case report.

Pulmonary enteric adenocarcinoma (PEAC) is a rare pathological type of lung adenocarcinoma, accounting for ~0.6% of primary lung adenocarcinoma, which has similar morphological and immunohistochemical characteristics to colorectal adenocarcinoma. Making a certain differential diagnosis of PEAC based on morphological and immunohistochemical results is difficult. It is known that PEAC may metastasize to the pancreas, skin, soleus muscle and intestine, but no bone metastasis has been reported. At our department, a rare case of PEAC with bone and lymph node metastasis was previously diagnosed. The present case study reports on a 58-year-old male patient encountered at our hospital with pain in the lumbar, back and right iliac with no obvious cause. Chest CT indicated a space-occupying lesion in the left upper lung lobe, enlarged lymph nodes in the mediastinum and left lung, and partial vertebral bone destruction. Enhanced CT results indicated multiple foci of active bone metabolism in the body, while rectal colonoscopy showed no obvious abnormalities. Histopathological and immunohistochemical results after right iliac bone puncture suggested stage IV PEAC with secondary malignancies in bones, mediastinal lymph node, hilar lymph node and left supraclavicular lymph node.

An FSV analysis approach to verify the robustness of the triple-correlation analysis theoretical framework.

Among all the gas disasters, gas concentration exceeding the threshold limit value (TLV) has been the leading cause of accidents. However, most systems still focus on exploring the methods and framework for avoiding reaching or exceeding TLV of the gas concentration from viewpoints of impacts on geological conditions and coal mining working-face elements. The previous study developed a Trip-Correlation Analysis Theoretical Framework and found strong correlations between gas and gas, gas and temperature, and gas and wind in the gas monitoring system. However, this framework's effectiveness must be examined to determine whether it might be adopted in other coal mine cases. This research aims to explore a proposed verification analysis approach-First-round-Second-round-Verification round (FSV) analysis approach to verify the robustness of the Trip-Correlation Analysis Theoretical Framework for developing a gas warning system. A mixed qualitative and quantitative research methodology is adopted, including a case study and correlational research. The results verify the robustness of the Triple-Correlation Analysis Theoretical Framework. The outcomes imply that this framework is potentially valuable for developing other warning systems. The proposed FSV approach can also be used to explore data patterns insightfully and offer new perspectives to develop warning systems for different industry applications.

Hexagonal warping effect in the Janus group-VIA binary monolayers with large Rashba spin splitting and piezoelectricity.

In this paper, the electronic band structure, Rashba effect, hexagonal warping, and piezoelectricity of Janus group-VIA binary monolayers STe2, SeTe2, and Se2Te are investigated based on density functional theory (DFT). Due to the inversion asymmetry and spin-orbit coupling (SOC), the STe2, SeTe2 and Se2Te monolayers exhibit large intrinsic Rashba spin splitting (RSS) at the Γ point with the Rashba parameters 0.19 eV Å, 0.39 eV Å, and 0.34 eV Å, respectively. Interestingly, based on the k·p model via symmetry analysis, the hexagonal warping effect and a nonzero spin projection component Sz arise at a larger constant energy surface due to nonlinear k3 terms. Then, the warping strength λ was obtained by fitting the calculated energy band data. Additionally, in-plane biaxial strain can significantly modulate the band structure and RSS. Furthermore, all these systems exhibit large in-plane and out-of-plane piezoelectricity due to inversion and mirror asymmetry. The calculated piezoelectric coefficients d11 and d31 are about 15-40 pm V-1 and 0.2-0.4 pm V-1, respectively, which are superior to those of most reported Janus monolayers. Because of the large RSS and piezoelectricity, the studied materials have great potential for spintronic and piezoelectric applications.

Using multi-focus group method as an effective tool for eliciting business system requirements: Verified by a case study.

This research aims to explore the multi-focus group method as an effective tool for systematically eliciting business requirements for business information system (BIS) projects. During the COVID-19 crisis, many businesses plan to transform their businesses into digital businesses. Business managers face a critical challenge: they do not know much about detailed system requirements and what they want for digital transformation requirements. Among many approaches used for understanding business requirements, the focus group method has been used to help elicit BIS needs over the past 30 years. However, most focus group studies about research practices mainly focus on a particular disciplinary field, such as social, biomedical, and health research. Limited research reported using the multi-focus group method to elicit business system requirements. There is a need to fill this research gap. A case study is conducted to verify that the multi-focus group method might effectively explore detailed system requirements to cover the Case Study business's needs from transforming the existing systems into a visual warning system. The research outcomes verify that the multi-focus group method might effectively explore the detailed system requirements to cover the business's needs. This research identifies that the multi-focus group method is especially suitable for investigating less well-studied, no previous evidence, or unstudied research topics. As a result, an innovative visual warning system was successfully deployed based on the multi-focus studies for user acceptance testing in the Case Study mine in Feb 2022. The main contribution is that this research verifies the multi-focus group method might be an effective tool for systematically eliciting business requirements. Another contribution is to develop a flowchart for adding to Systems Analysis & Design course in information system education, which may guide BIS students step by step on using the multi-focus group method to explore business system requirements in practice.

A novel hypoxia- and lactate metabolism-related signature to predict prognosis and immunotherapy responses for breast cancer by integrating machine learning and bioinformatic analyses.

Background: Breast cancer is the most common cancer worldwide. Hypoxia and lactate metabolism are hallmarks of cancer. This study aimed to construct a novel hypoxia- and lactate metabolism-related gene signature to predict the survival, immune microenvironment, and treatment response of breast cancer patients. Methods: RNA-seq and clinical data of breast cancer from The Cancer Genome Atlas database and Gene Expression Omnibus were downloaded. Hypoxia- and lactate metabolism-related genes were collected from publicly available data sources. The differentially expressed genes were identified using the "edgeR" R package. Univariate Cox regression, random survival forest (RSF), and stepwise multivariate Cox regression analyses were performed to construct the hypoxia-lactate metabolism-related prognostic model (HLMRPM). Further analyses, including functional enrichment, ESTIMATE, CIBERSORTx, Immune Cell Abundance Identifier (ImmuCellAI), TIDE, immunophenoscore (IPS), pRRophetic, and CellMiner, were performed to analyze immune status and treatment responses. Results: We identified 181 differentially expressed hypoxia-lactate metabolism-related genes (HLMRGs), 24 of which were valuable prognostic genes. Using RSF and stepwise multivariate Cox regression analysis, five HLMRGs were included to establish the HLMRPM. According to the medium-risk score, patients were divided into high- and low-risk groups. Patients in the high-risk group had a worse prognosis than those in the low-risk group (P < 0.05). A nomogram was further built to predict overall survival (OS). Functional enrichment analyses showed that the low-risk group was enriched with immune-related pathways, such as antigen processing and presentation and cytokine-cytokine receptor interaction, whereas the high-risk group was enriched in mTOR and Wnt signaling pathways. CIBERSORTx and ImmuCellAI showed that the low-risk group had abundant anti-tumor immune cells, whereas in the high-risk group, immunosuppressive cells were dominant. Independent immunotherapy datasets (IMvigor210 and GSE78220), TIDE, IPS and pRRophetic analyses revealed that the low-risk group responded better to common immunotherapy and chemotherapy drugs. Conclusions: We constructed a novel prognostic signature combining lactate metabolism and hypoxia to predict OS, immune status, and treatment response of patients with breast cancer, providing a viewpoint for individualized treatment.

A comparative analysis of the principal component analysis and entropy weight methods to establish the indexing measurement.

BACKGROUND: As the world's largest coal producer, China was accounted for about 46% of global coal production. Among present coal mining risks, methane gas (called gas in this paper) explosion or ignition in an underground mine remains ever-present. Although many techniques have been used, gas accidents associated with the complex elements of underground gassy mines need more robust monitoring or warning systems to identify risks. This paper aimed to determine which single method between the PCA and Entropy methods better establishes a responsive weighted indexing measurement to improve coal mining safety. METHODS: Qualitative and quantitative mixed research methodologies were adopted for this research, including analysis of two case studies, correlation analysis, and comparative analysis. The literature reviewed the most-used multi-criteria decision making (MCDM) methods, including subjective methods and objective methods. The advantages and disadvantages of each MCDM method were briefly discussed. One more round literature review was conducted to search publications between 2017 and 2019 in CNKI. Followed two case studies, correlation analysis and comparative analysis were then conducted. Research ethics was approved by the Shanxi Coking Coal Group Research Committee. RESULTS: The literature searched a total of 25,831publications and found that the PCA method was the predominant method adopted, and the Entropy method was the second most widely adopted method. Two weighting methods were compared using two case studies. For the comparative analysis of Case Study 1, the PCA method appeared to be more responsive than the Entropy. For Case Study 2, the Entropy method is more responsive than the PCA. As a result, both methods were adopted for different cases in the case study mine and finally deployed for user acceptance testing on 5 November 2020. CONCLUSIONS: The findings and suggestions were provided as further scopes for further research. This research indicated that no single method could be adopted as the better option for establishing indexing measurement in all cases. The practical implication suggests that comparative analysis should always be conducted on each case and determine the appropriate weighting method to the relevant case. This research recommended that the PCA method was a dimension reduction technique that could be handy for identifying the critical variables or factors and effectively used in hazard, risk, and emergency assessment. The PCA method might also be well-applied for developing predicting and forecasting systems as it was sensitive to outliers. The Entropy method might be suitable for all the cases requiring the MCDM. There is also a need to conduct further research to probe the causal reasons why the PCA and Entropy methods were applied to each case and not the other way round. This research found that the Entropy method provides higher accuracy than the PCA method. This research also found that the Entropy method demonstrated to assess the weights of the higher dimension dataset was higher sensitivity than the lower dimensions. Finally, the comprehensive analysis indicates a need to explore a more responsive method for establishing a weighted indexing measurement for warning applications in hazard, risk, and emergency assessments.

Sc/C codoping effect on the electronic and optical properties of the TiO2 (101) surface: a first-principles study.

Extension of the light absorption range and a reduction of the possibility of the photo-generated electron-hole pair recombination are the main tasks to break the bottleneck of the photocatalytic application of TiO2. In this paper, we systematically investigate the electronic and optical properties of Sc-doped, C-doped, and Sc/C-codoped TiO2 (101) surfaces using spin-polarized DFT+U calculations. The absorption coefficient of the Sc/C-codoped TiO2 (101) surfaces were enhanced the most compared with the other two doped systems in the high energy region of visible light, which can be attributed to the shallow impurity states. Furthermore, we studied the optical absorption properties with the change of the impurity concentration. The Sc/C-codoped TiO2 (101) surface with 5.56% impurity concentration exhibited optimal photocatalytic performance in the visible region. These results may be helpful for designing the high-performance of the photocatalysts by doping.

Biaxial Tensile Strain-Induced Enhancement of Thermoelectric Efficiency of α-Phase Se2Te and SeTe2 Monolayers.

Thermoelectric (TE) materials can convert waste heat into electrical energy, which has attracted great interest in recent years. In this paper, the effect of biaxial-tensile strain on the electronic properties, lattice thermal conductivity, and thermoelectric performance of α-phase Se2Te and SeTe2 monolayers are calculated based on density-functional theory and the semiclassical Boltzmann theory. The calculated results show that the tensile strain reduces the bandgap because the bond length between atoms enlarges. Moreover, the tensile strain strengthens the scatting rate while it weakens the group velocity and softens the phonon model, leading to lower lattice thermal conductivity kl. Simultaneously, combined with the weakened kl, the tensile strain can also effectively modulate the electronic transport coefficients, such as the electronic conductivity, Seebeck coefficient, and electronic thermal conductivity, to greatly enhance the ZT value. In particular, the maximum n-type doping ZT under 1% and 3% strain increases up to six and five times higher than the corresponding ZT without strain for the Se2Te and SeTe2 monolayers, respectively. Our calculations indicated that the tensile strain can effectively enhance the thermoelectric efficiency of Se2Te and SeTe2 monolayers and they have great potential as TE materials.

Theoretical studies on the electronic structures and optical properties of (Cu, C)-codoped rutile TiO2 from GGA+U calculations.

The electronic structures, formation energy and optical properties of Cu-doped, C-doped, and (Cu, C)-codoped TiO2 were investigated by the projector augmented wave (PAW) method within GGA + U approximation. The results show that the lattice distortion of the Cu@i1&C@i2 system is the largest in all doping systems. The optical absorption edges of the C@i system and the Cu@i1&C@i2 system appear a blue-shift, which is attributed to the band gap expansion and some deep states generation. The Cu@i system exhibits a reduction in band gap and a generation of the hole state, such as it emerges the highest optical absorption in all doping systems.

Baicalein induces apoptosis and autophagy of breast cancer cells via inhibiting PI3K/AKT pathway in vivo and vitro.

PURPOSE: Baicalein, a widely used Chinese herbal medicine, has shown anticancer effects on many types of human cancer cell lines. However, little is known about the underlying mechanism in human breast cancer cells. In this study, we examined the apoptotic and autophagic pathways activated following baicalein treatment in human breast cancer cells in vitro and in vivo. MATERIALS AND METHODS: In in vitro study, we used MTT and clone formation assay to confirm the inhibitory role of baicalein on proliferation of MCF-7 and MDA-MB-231 breast cancer cells. Apoptosis was detected employing Hoechst 33258 staining, JC-1 staining, and flow cytometry. Autophagy was monitored by acridine orange staining and transmission electron microscopy observation. Quantitative real-time PCR and Western blot analysis were employed to study the effects of baicalein on PI3K/AKT signaling components of MCF-7 and MDA-MB-231 breast cancer cells. In in vivo study, the effect of baicalein was tested with a breast cancer cells transplantation tumor model. RESULTS: Our study showed that baicalein has the potential to suppress cell proliferation, induce apoptosis and autophagy of breast cancer cells in vitro and in vivo. Furthermore, baicalein significantly downregulated the expression of p-AKT, p-mTOR, NF-κB, and p-IκB while enhancing the expression of IκB in MCF-7 and MDA-MB-231 cells. It also decreased the p-AKT/AKT and p-mTOR/mTOR ratios. CONCLUSION: Our study demonstrated that baicalein induces apoptosis and autophagy of breast cancer cells via inhibiting the PI3K/AKT signaling pathway in vivo and vitro. Our study revealed that baicalein may be a potential therapeutic agent for breast cancer.

MiR-429 suppresses neurotrophin-3 to alleviate perineural invasion of pancreatic cancer.

Perineural invasion (PNI) potentially increases the risk of relapse and abdominal pain in patients with pancreatic ductal adenocarcinoma (PDAC). However, the underlying mechanisms of PNI of PDAC is incompletely revealed. Our study aimed to investigate roles of miR-429 in modulating PNI in PDAC. We found that miR-429 was downregulated in PDAC cancer tissues and was profoundly decreased in tissues with PNI. It was reduced in nine of the ten examined pancreatic cancer cell lines. MiR-429 mimics restored its cellular expressions in MIA PaCa-2 and BxCP3 cells and significantly suppressed cell viability and invasion of the cancer cells. The online bioinformatic software predicted that neurotrophin-3 (NT-3) was a potential target gene of miR-429. It was showed that NT-3 mRNA elevated in PC cancer tissues, especially in patients presenting PNI. MiR-429 upregulation substantially suppressed the NT-3 mRNA and secretion in cancer cells. Also, the dual luciferase reporter assays confirmed the interaction between miR-429 and NT-3. When co-culturing the two PDAC cells with PC-12 cells, the invaded cell counts significantly increased comparing with the sole culture of cancer cells. However, miR-429 mimic transfection or NT-3 blocking retarded the cancer invasion in the co-culture system. Besides, we found that cancer cells conditioned medium (CM) treatment significantly increased the neurite outgrowth percentage in PC-12 cells, which was suppressed by culturing with CM from miR-429 mimics-transfected cells. In the CM cultured PC-12 cells, NT-3 receptor TrkC as well as pain-related proteins TRPV1 and TRPV2 significantly elevated. Collectively, miR-429 potentially suppressed neurotrophin-3 to alleviate PNI of PDAC.

Baicalein suppress EMT of breast cancer by mediating tumor-associated macrophages polarization.

Tumor associated macrophages (TAMs) are the main infiltrating component in the tumor microenvironment and play an important role in cancer progression. Baicalein has a wide range of pharmacological properties. This study explores the potential effect of baicalein on macrophages polarization and epithelial-mesenchymal transition (EMT) of breast cancer. Co-culture system was established to evaluate the interaction between TAMs and breast cancer cells. Then the role of baicalein in modulating TAMs function was assessed. Finally, breast cancer mouse model was established to study the underlying mechanism. In vitro experiments showed that co-culture with M2 macrophages significantly enhanced EMT of both MDA-MB-231 and MCF-7 breast cancer cells. Baicalein could regulate polarization of M2 and attenuate TGF-ß1 secretion. In vivo experiments showed that compared with the MDA-MB-231 + M2 group, tumor growth and metastasis of baicalein + MDA-MB-231 + M2 group was significantly inhibited, with smaller tumor size and decreased lung metastasis lesions. Our findings suggest that the regulation of TAMs may be a novel mechanism underlying the anti-tumor effects of baicalein in breast cancer.

Effects of area, aspect ratio and orientation of rectangular nanohole on the tensile strength of defective graphene - a molecular dynamics study.

Molecular dynamics simulations with adaptive intermolecular reactive empirical bond order (AIREBO) potential are performed to investigate the effects of rectangular nanoholes with different areas, aspect ratios (length/width ratios) and orientations on the tensile strength of defective graphene. The simulations reveal that variation of area, aspect ratio and orientation of rectangular nanohole can significantly affect the tensile strength of defective graphene. For example, defective graphene with a larger area of rectangular nanohole shows a bigger drop in tensile strength. It was found that the tensile strength of both armchair and zigzag edged graphene monotonically decreases with area increases in rectangular nanohole. Changes in aspect ratio and orientation of rectangular nanohole, however, can either decrease or increase the tensile strength of defective graphene, dependent on the tensile direction. This study also presents information that the tensile strength of defective graphene with large area of nanohole is more sensitive to changes in aspect ratio and orientation than is defective graphene with small area of nanohole. Interestingly, variation of tensile strength of defective graphene from MD simulations is in good agreement with predictions from energy-based quantized fracture mechanics (QFM). The present results suggest that the effect of nanoholes on the tensile strength of graphene provides essential information for predictive optimization of mechanical properties and controllable structural modification of graphene through defect engineering.

Tumor-infiltrating lymphocytes are associated with ß-catenin overexpression in breast cancer.

BACKGROUND: Inhibition of lymphocytes infiltration and activity may impair antitumor immune response and limit treatment responsiveness. Wnt/ß-catenin pathway has been suggested to contribute to immune evasion in tumor by suppressing the function of immune cells and excluding T cell infiltration. However, the effects of Wnt/ß-catenin on TILs recruitment remain controversial. OBJECTIVE: We aimed to investigate whether intratumoral Wnt/ß-catenin signaling could affect the lymphocyte infiltration in breast cancer. METHODS: The distribution of stromal TILs, CD8+ and FOXP3+ TIL subsets, and the expression of ß-catenin were separately assessed on consecutive sections of 96 breast cancer specimens. RESULTS: Both stromal infiltrated TILs and ß-catenin expression were upregulated in hormone receptor negative HER2-enriched and TNBC subtypes. Furthermore, high levels of stromal TILs as well as CD8+ or FOXP3+ TIL subsets were associated with ß-catenin overexpression by breast cancer, respectively. CONCLUSIONS: For the first time, we demonstrated that rather than excluding lymphocytes infiltration as reported in mela-noma, high levels of TILs were associated with ß-catenin overexpression in BC. Wnt/ß-catenin signaling may play a critical role in BC immunity, particularly in HER2-enriched and triple negative BC, and may serve as a potential target for regulating immune infiltrates in breast cancer.