The mechanical property changes in three kinds of ternary borosilicate glasses (named NBS glasses) induced by 8.0-MeV Au3+ were studied by nanoindentation measurements. For these borosilicate ...glasses, the molar ratio R = Na2O/B2O3 is varied (1.34, 0.75, and 0.40 for NBS1, NBS2, and NBS3, respectively), while their molar ratio K = SiO2/B2O3 is fixed at 4.04. The nanoindentation results indicate that both the hardness and reduced Young modulus were decreased after irradiation. No obvious difference in both hardness and modulus variations of these three NBS glasses was observed. Based on the main structures of their pristine samples, the reedmergnerite groups containing Si-O-BIV may be the structural origin of Au-ion-irradiated mechanical property changes in the homogeneous glasses with R > 0.5. However, the modification of the silica network and phase separation may dominate the mechanical property changes for glasses with R ≤ 0.5. The ion- and electron-irradiation-induced mechanical property changes of these NBS glasses were also compared in this study. The extended incubation dose and the slower decreasing rate can be observed in electron-irradiation-induced hardness and modulus variations, which may be caused by the different mechanisms between both irradiation scenarios.
•Mechanical property changes of three sodium borosilicate glasses irradiated with 8-MeV Au3+ ions were investigated.•No significant composition dependence of mechanical property changes was observed in ion-irradiated borosilicate glasses.•Both the deposited nuclear and electronic energy are responsible for the variations in mean hardness and reduced Young modulus.•The reedmergnerite groups containing Si-O-BIV network may be the structural origin of Au-ion-irradiated glasses with R > 0.5.•The modification of the silica network, as well as phase separation, may dominate the glasses with R ≤ 0.5.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A simple strontium phosphate (SrP) conversion coating process was developed to protect magnesium (Mg) from the initial degradation post-implantation. The coating morphology, deposition rate and ...resultant phases are all dependent on the processing temperature, which determines the protective ability for Mg in minimum essential medium (MEM). Coatings produced at 80°C are primarily made up of strontium apatite (SrAp) with a granular surface, a high degree of crystallinity and the highest protective ability, which arises from retarding anodic dissolution of Mg in MEM. Following 14days’ immersion in MEM, the SrAp coating maintained its integrity with only a small fraction of the surface corroded. The post-degradation effect of uncoated Mg and Mg coated at 40 and 80°C on the proliferation and differentiation of human mesenchymal stem cells was also studied, revealing that the SrP coatings are biocompatible and permit proliferation to a level similar to that of pure Mg. The present study suggests that the SrP conversion coating is a promising option for controlling the early rapid degradation rate, and hence hydrogen gas evolution, of Mg implants without adverse effects on surrounding cells and tissues.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
AbstractThe rotational failure mechanism with a log-spiral is most efficient in upper-bound limit analysis for homogenous slopes, but it cannot work well in regard to layered slopes. In this study, ...the log-spiral rotational mechanism is extended for layered slopes by a multicenter method that focuses on the variations of slip surfaces between adjacent soil layers. There are multiple rigid blocks, each of which rotates around a separate center, in the proposed mechanism, and the additional rupture surface is between the adjacent blocks. Several typical examples are analyzed by the proposed method and other published mechanisms based on the limit equilibrium method or limit analysis method. Benefiting from the log-spiral, the proposed mechanism has fewer rigid blocks than that in other published mechanisms based on the limit equilibrium method or upper-bound limit analysis. The factors of safety obtained by the proposed method are smaller than existing upper-bound mechanisms, and the slip surfaces lie well in the plastic zones obtained by the finite element method (FEM). These comparisons demonstrate the applicability and advantages of the proposed failure mechanism. Furthermore, the influence of nonassociated flow rule on a two-layer slope is considered, and associated effect charts are given.
Nickel-based superalloys are used in high strength, high-value applications, such as gas turbine discs in aero engines. In these applications the integrity of the disc is critical and therefore ...understanding crack initiation mechanisms is of high importance. With an increasing trend towards powder metallurgy routes for discs, sometimes unwanted non-metallic inclusions are introduced during manufacture. These inclusions vary in size from ∼10 μm to 200 μm which is comparable to the grain size of the nickel-based superalloys. Cracks often initiate near these inclusions, and the precise size, shape, location and path of these cracks are microstructurally sensitive. In this study, we focus on crack initiation at the microstructural length scale using a controlled three-point bend test, with the inclusion deliberately located within the tensile fibre of the beam. Electron backscatter diffraction (EBSD) is combined with high spatial resolution digital image correlation (HR-DIC) to explore full field plastic strain distributions, together with finite element modelling, to understand the micro-crack nucleation mechanisms. This full field information and controlled sample geometry enable us to systematically test crack nucleation criteria. We find that a combined stored energy and dislocation density provide promising results. These findings potentially facilitate more reliable and accurate lifing prediction tools to be developed and applied to engineering components.
Display omitted
•High resolution digital image correlation.•High resolution electron backscatter diffraction.•Crack nucleation.•Non-metallic inclusion.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•Haufe-transformed weights are much more reliable than original regression weights when computing feature importance.•Feature importance reliability is strongly positively correlated with prediction ...accuracy across phenotypes.•We show mathematically that feature importance reliability is necessary, but not sufficient, for low feature importance error.•We discuss how our theoretical results relate with the reliability of imaging features and behavioral measures.
There is significant interest in using neuroimaging data to predict behavior. The predictive models are often interpreted by the computation of feature importance, which quantifies the predictive relevance of an imaging feature. Tian and Zalesky (2021) suggest that feature importance estimates exhibit low split-half reliability, as well as a trade-off between prediction accuracy and feature importance reliability across parcellation resolutions. However, it is unclear whether the trade-off between prediction accuracy and feature importance reliability is universal. Here, we demonstrate that, with a sufficient sample size, feature importance (operationalized as Haufe-transformed weights) can achieve fair to excellent split-half reliability. With a sample size of 2600 participants, Haufe-transformed weights achieve average intra-class correlation coefficients of 0.75, 0.57 and 0.53 for cognitive, personality and mental health measures respectively. Haufe-transformed weights are much more reliable than original regression weights and univariate FC-behavior correlations. Original regression weights are not reliable even with 2600 participants. Intriguingly, feature importance reliability is strongly positively correlated with prediction accuracy across phenotypes. Within a particular behavioral domain, there is no clear relationship between prediction performance and feature importance reliability across regression models. Furthermore, we show mathematically that feature importance reliability is necessary, but not sufficient, for low feature importance error. In the case of linear models, lower feature importance error is mathematically related to lower prediction error. Therefore, higher feature importance reliability might yield lower feature importance error and higher prediction accuracy. Finally, we discuss how our theoretical results relate with the reliability of imaging features and behavioral measures. Overall, the current study provides empirical and theoretical insights into the relationship between prediction accuracy and feature importance reliability.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
As a new method, support vector machine (SVM) were applied for prediction of toxicity of different data sets compared with other two common methods, multiple linear regression (MLR) and RBFNN. ...Quantitative structure–activity relationships (QSAR) models based on calculated molecular descriptors have been clearly established. Among them, SVM model gave the highest
q
2 and correlation coefficient
R. It indicates that the SVM performed better generalization ability than the MLR and RBFNN methods, especially in the test set and the whole data set. This eventually leads to better generalization than neural networks, which implement the empirical risk minimization principle and may not converge to global solutions. We would expect SVM method as a powerful tool for the prediction of molecular properties.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
HER2 mutations and amplifications have been identified as oncogenic drivers in lung cancers. Dacomitinib, an irreversible inhibitor of HER2, EGFR (HER1), and HER4 tyrosine kinases, has demonstrated ...activity in cell-line models with HER2 exon 20 insertions or amplifications. Here, we studied dacomitinib in patients with HER2-mutant or amplified lung cancers.
As a prespecified cohort of a phase II study, we included patients with stage IIIB/IV lung cancers with HER2 mutations or amplification. We gave oral dacomitinib at 30–45 mg daily in 28-day cycles. End points included partial response rate, overall survival, and toxicity.
We enrolled 30 patients with HER2-mutant (n = 26, all in exon 20 including 25 insertions and 1 missense mutation) or HER2-amplified lung cancers (n = 4). Three of 26 patients with tumors harboring HER2 exon 20 mutations 12%; 95% confidence interval (CI) 2% to 30% had partial responses lasting 3+, 11, and 14 months. No partial responses occurred in four patients with tumors with HER2 amplifications. The median overall survival was 9 months from the start of dacomitinib (95% CI 7–21 months) for patients with HER2 mutations and ranged from 5 to 22 months with amplifications. Treatment-related toxicities included diarrhea (90%; grade 3/4: 20%/3%), dermatitis (73%; grade 3/4: 3%/0%), and fatigue (57%; grade 3/4: 3%/0%). One patient died on study likely due to an interaction of dacomitinib with mirtazapine.
Dacomitinib produced objective responses in patients with lung cancers with specific HER2 exon 20 insertions. This observation validates HER2 exon 20 insertions as actionable targets and justifies further study of HER2-targeted agents in specific HER2-driven lung cancers.
NCT00818441.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We conducted a systematic study of top susceptibility variants from a genome-wide association (GWA) study of bipolar disorder to gain insight into the functional consequences of genetic variation ...influencing disease risk. We report here the results of experiments to explore the effects of these susceptibility variants on DNA methylation and mRNA expression in human cerebellum samples. Among the top susceptibility variants, we identified an enrichment of cis regulatory loci on mRNA expression (eQTLs), and a significant excess of quantitative trait loci for DNA CpG methylation, hereafter referred to as methylation quantitative trait loci (mQTLs). Bipolar disorder susceptibility variants that cis regulate both cerebellar expression and methylation of the same gene are a very small proportion of bipolar disorder susceptibility variants. This finding suggests that mQTLs and eQTLs provide orthogonal ways of functionally annotating genetic variation within the context of studies of pathophysiology in brain. No lymphocyte mQTL enrichment was found, suggesting that mQTL enrichment was specific to the cerebellum, in contrast to eQTLs. Separately, we found that using mQTL information to restrict the number of single-nucleotide polymorphisms studied enhances our ability to detect a significant association. With this restriction a priori informed by the observed functional enrichment, we identified a significant association (rs12618769, P(bonferroni)<0.05) from two other GWA studies (TGen+GAIN; 2191 cases and 1434 controls) of bipolar disorder, which we replicated in an independent GWA study (WTCCC). Collectively, our findings highlight the importance of integrating functional annotation of genetic variants for gene expression and DNA methylation to advance the biological understanding of bipolar disorder.
Full text
Available for:
DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
PDF
