Crossmodal to unimodal transfer of temporal perceptual learning.

Subsecond temporal processing is crucial for activities requiring precise timing. Here, we investigated perceptual learning of crossmodal (auditory-visual or visual-auditory) temporal interval discrimination (TID) and its impacts on unimodal (visual or auditory) TID performance. The research purpose was to test whether learning is based on a more abstract and conceptual representation of subsecond time, which would predict crossmodal to unimodal learning transfer. The experiments revealed that learning to discriminate a 200-ms crossmodal temporal interval, defined by a pair of visual and auditory stimuli, significantly reduced crossmodal TID thresholds. Moreover, the crossmodal TID training also minimized unimodal TID thresholds with a pair of visual or auditory stimuli at the same interval, even if crossmodal TID thresholds are multiple times higher than unimodal TID thresholds. Subsequent training on unimodal TID failed to reduce unimodal TID thresholds further. These results indicate that learning of high-threshold crossmodal TID tasks can benefit low-threshold unimodal temporal processing, which may be achieved through training-induced improvement of a conceptual representation of subsecond time in the brain.

Functional analysis of transgenic cry1Ah-1 maize.

Maize is an important food crop in the world, but the yield and quality of maize have been significantly reduced due to the impact of insect pests. In order to address this issue, the cry1Ah gene was subjected to error-prone PCR for mutagenesis, and subsequently, the mutant cry1Ah-1 gene was introduced into maize inbred line GSH9901 callus using the Agrobacterium-mediated method. The T2 generation transformed plants were obtained by subculture, and 9 transgenic positive plants were obtained by molecular detection which was carried out by PCR, qRT-PCR, Bt gold-labeled immunoassay test strips, Western blot and ELISA. It was found that the Cry1Ah-1 gene could be transcribed normally in maize leaves, of which OE1 and OE3 had higher relative expression levels and could successfully express proteins of 71.94 KD size. They were expressed in different tissues at the 6-leaf stage, heading stage and grain-filling stage, and could ensure the protection of maize from corn borer throughout the growth period. The biological activities of OE1 and OE3 were tested indoors and in the field, and the results showed that in indoors, the corn borer that fed on OE1 and OE3 corn leaves had a mortality rate of 100 % after 3 days; in the field, OE1 and OE3 had strong insecticidal activity against corn borer, reaching a high resistance level. In conclusion, the transgenic cry1Ah-1 maize has a strong insecticidal effect on corn borer, and has a good prospect of commercialization.

Serial Cardiac MRI for Quantification of the Dynamics of Anthracycline-Induced Subclinical Myocardial Injury.

BACKGROUND: Anthracyclines are known to be associated with chemotherapy-induced cardiotoxicity. Limited data focus on dynamic myocardial injury during the course of chemotherapy in patients with breast cancer. PURPOSE: To investigate the variation of tissue characterization and myocardial deformation derived by cardiac MRI during anthracycline chemotherapy. STUDY TYPE: Prospective. POPULATION: Fifty-eight female breast cancer patients (mean age: 52.82 ± 2.61 years) were enrolled. FIELD STRENGTH/SEQUENCE: A 3.0-T, cardiac MRI including cine balanced steady-state free precession, a modified Looker-Locker inversion recovery (MOLLI), and a fast spin echo (FSE) T2-weighted sequences were performed. ASSESSMENT: Cardiac MRI was performed baseline and after two, four, and six cycles of chemotherapy. Assessment of global longitudinal strain (GLS), global circumstance strain (GCS), global radial strain (GRS), and strain rate (GLS-s, GCS-s, GRS-s) and T1, T2 and T2* were accomplished by CVI42. The anthracycline dose and risk factors were also collected before each cardiac MRI. STATISTICAL TESTS: Analysis of variance (ANOVA) for repeated measures was used to compare the changes in LVEF cardiac function, strain and T1/T2/T2* parameters over time. Pearson correlation analyses were performed to estimate the potential associations between differences in myocardial characteristics (∆) and the chemotherapy cycle. A P value <0.05 was considered statistically significant. RESULTS: LVEF was not significantly different from pretreatment MRI regarding each cycle of chemotherapy (P = 0.54). Compared with baseline, patients had significantly lower GLS (-15.85% ± 0.83%, -14.50% ± 0.88%, -12.34% ± 1.01% vs. -18.82% ± 0.92%) and GLS-s (-0.71% ± 0.07%, -0.65% ± 0.05%, -0.64% ± 0.04% vs. -0.95 ± 0.06%) and increased T2 values (57.21 ± 4.27 msec, 58.60 ± 3.93 msec, 58.10 ± 3.17 msec vs. 43.88 ± 3.28 msec) at two, four and six cycles of chemotherapy treatment. ∆GLS and ∆GLS-s were significantly associated with the chemotherapy cycle (correlation coefficients for GLS = 0.75, GLS-s = 0.75). DATA CONCLUSION: Cardiac MRI can precisely detect the dynamic changes of anthracycline-induced subclinical myocardial injury that is represented as a gradually decrease in GLS and GLS-s. These parameters may provide new insight for monitoring risk and therapy in patients with breast cancer. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 1.

Unraveling different influences of the fraction of the tetragonal phase in oxide films on the corrosion resistance of Zr alloys from the phase transition mechanism.

The mechanism of Sn and Nb influence on the fraction of tetragonal ZrO2 in oxide films on Zr alloys and their influence mechanism on corrosion resistance of Zr alloys, despite decades of research, are ambiguous due to the lack of kinetic knowledge of phase evolution of ZrO2 with doping. Using stochastic surface walking and density functional theory calculations, we investigate the influence of Nb and Sn on the stability of tetragonal (t) and monoclinic (m) ZrO2, and t-m phase transition in oxide films. We found that though Nb and Sn result in similar apparent variation trends in the t-phase fraction in oxide films, their influences on t-m phase transition differ significantly, which is the underlying origin of different influences of the t-phase fraction in oxide films on the corrosion resistance of Zr alloys with Sn and Nb alloying. These results clarify an important aspect of the relationship between the microstructure and corrosion resistance of Zr alloys.

Negative perceived context of reception and sociocultural resources on mental health among Hispanic and Somali adolescents.

Although immigrant negative perceived context of reception (PCOR), perceptions of the opportunities and degree of acceptance in an immigrant-receiving community, has been linked with compromised adolescent well-being, receiving contexts may differ by region and for youth from different ethnic backgrounds. The current study examines how negative PCOR and factors that promote resilience differentially shape mental health among Hispanic and Somali adolescents in Minnesota. Hispanic (n = 163) and Somali (n = 186) first- and second-generation youth aged 12-19 completed a survey on negative PCOR, assets and resources (i.e., ethnic identity, social support, religious participation), and mental well-being (i.e., anxiety and depressive symptoms). Parents and caregivers also completed a survey on PCOR and social support. Adolescent negative PCOR, relative to parent/caregiver negative PCOR, was associated with higher adolescent anxiety and depressive symptoms. Religious participation and social support, reported by both parent/caregiver and adolescent, was associated with lower anxiety and depressive symptoms. Additionally, among Hispanic adolescents, social support buffered the effects of negative PCOR on depressive symptoms. Conversely, strong ethnic identity was associated with higher depressive symptoms for both groups, suggesting acculturative and assimilative pressures play an important role in adolescent mental health. Although social ties can be weakened postmigration, our results indicate that social and religious resources remain beneficial. Given that by the end of the next decade over 50% of the US youth population will identify as part of a racial or ethnic minority group, positive postimmigration adaptation is a critical public health concern.

Orientation Tuning and End-stopping in Macaque V1 Studied with Two-photon Calcium Imaging.

Orientation tuning is a fundamental response property of V1 neurons and has been extensively studied with single-/multiunit recording and intrinsic signal optical imaging. Long-term 2-photon calcium imaging allows simultaneous recording of hundreds of neurons at single neuron resolution over an extended time in awake macaques, which may help elucidate V1 orientation tuning properties in greater detail. We used this new technology to study the microstructures of orientation functional maps, as well as population tuning properties, in V1 superficial layers of 5 awake macaques. Cellular orientation maps displayed horizontal and vertical clustering of neurons according to orientation preferences, but not tuning bandwidths, as well as less frequent pinwheels than previous estimates. The orientation tuning bandwidths were narrower than previous layer-specific single-unit estimates, suggesting more precise orientation selectivity. Moreover, neurons tuned to cardinal and oblique orientations did not differ in quantities and bandwidths, likely indicating minimal V1 representation of the oblique effect. Our experimental design also permitted rough estimates of length tuning. The results revealed significantly more end-stopped cells at a more superficial 150 µm depth (vs. 300 µm), but unchanged orientation tuning bandwidth with different length tuning. These results will help construct more precise models of V1 orientation processing.

Experiences of discrimination and language brokering: Exploring risks and protective factors.

OBJECTIVES: Language brokering (LB) often occurs in public places, putting youth who broker at risk for experiencing discrimination while engaging in brokering. Guided by the risk and resilience theoretical framework, the present study goals were twofold: (a) to examine the association between discrimination and LB, and (b) to explore moderating abilities of ethnic identity and family dynamics. METHOD: Data were collected from 458 young adults (Mage = 21.36, 80% female). Participants were from a diverse region in the United States, and a majority of them self-identified as Latino (66.2%). Participants were invited to complete a one-time online survey about their LB and family experiences. RESULTS: We found that discrimination was negatively associated with LB for these young people. Specifically, discrimination was related to higher LB burden and higher LB role reversal, and lower LB efficacy. In addition, we found that ethnic-racial identity (ERI) acted as a moderator of LB role reversal against discrimination, and that negative family dynamics moderated the association between discrimination and LB. Positive family dynamics were not successful in buffering against negative effects of discrimination. CONCLUSIONS: Our findings indicate that young people who broker seem to be negatively impacted by discrimination. The effects of discrimination on LB role reversal could be alleviated by strong ERI; however, the same is not true for LB burden and LB efficacy. Furthermore, negative family dynamics exacerbated the negative effects of discrimination on LB, and positive family dynamics did not serve as a buffer against discrimination. Implications for those working with language brokers are discussed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Praseodymium selective fluorescence recognition based on GdPO4: Tb3+ probe via energy transfer from Tb3+ to Pr3+ ions.

A novel strategy is proposed based on the efficient energy transfer from Tb3+ to Pr3+ for the sensitive and selective discrimination of praseodymium ions due to the matched energy levels of 5D4 (Tb3+) and 3P0 (Pr3+). The electron of Tb3+ transfers from the ground state to the excited state under the excitation of ultraviolet light and relaxes to the 5D4 level. In the presence of Pr3+ the electron has no time to return to the ground state, thus it transfers to the 3P0 level of Pr3+ resulting in the quenching of Tb3+ luminescence. In the case of GdPO4: Tb3+ nanowire, its fluorescence intensity at 545 nm linearly decreased when Pr3+ concentration ranged from 1 × 10-7 to 1 × 10-5 M, and the detection limit was 75 nM. To further investigate the sensing mechanism, CePO4: Tb3+, YPO4: Tb3+, and YBO3: Tb3+ nanoparticles were also synthesized for Pr3+ ion detection. For all materials, similar fluorescence quenching by Pr3+ ions occurred, which confirmed the efficient energy transfer from Tb3+ to Pr3+ ions. Utilizing the matched energy levels of 5D4 (Tb3+) and 3P0 (Pr3+), for the first time, we proposed a novel strategy (taking GdPO4: Tb3+ probe as the example) based on the efficient energy transfer from Tb3+ to Pr3+ for the sensitive and selective discrimination of praseodymium ions.

Immune-related lncRNAs as predictors of survival in breast cancer: a prognostic signature.

BACKGROUND: Breast cancer is a highly heterogeneous disease, this poses challenges for classification and management. Long non-coding RNAs play acrucial role in the breast cancersdevelopment and progression, especially in tumor-related immune processes which have become the most rapidly investigated area. Therefore, we aimed at developing an immune-related lncRNA signature to improve the prognosis prediction of breast cancer. METHODS: We obtained breast cancer patient samples and corresponding clinical data from The Cancer Genome Atlas (TCGA) database. Immune-related lncRNAs were screened by co-expression analysis of immune-related genes which were downloaded from the Immunology Database and Analysis Portal (ImmPort). Clinical patient samples were randomly separated into training and testing sets. In the training set, univariate Cox regression analysis and LASSO regression were utilized to build a prognostic immune-related lncRNA signature. The signature was validated in the training set, testing set, and whole cohorts by the Kaplan-Meier log-rank test, time-dependent ROC curve analysis, principal component analysis, univariate andmultivariate Cox regression analyses. RESULTS: A total of 937 immune- related lncRNAs were identified, 15 candidate immune-related lncRNAs were significantly associated with overall survival (OS). Eight of these lncRNAs (OTUD6B-AS1, AL122010.1, AC136475.2, AL161646.1, AC245297.3, LINC00578, LINC01871, AP000442.2) were selected for establishment of the risk prediction model. The OS of patients in the low-risk group was higher than that of patients in the high-risk group (p = 1.215e - 06 in the training set; p = 0.0069 in the validation set; p = 1.233e - 07 in whole cohort). The time-dependent ROC curve analysis revealed that the AUCs for OS in the first, eighth, and tenth year were 0.812, 0.81, and 0.857, respectively, in the training set, 0.615, 0.68, 0.655 in the validation set, and 0.725, 0.742, 0.741 in the total cohort. Multivariate Cox regression analysis indicated the model was a reliable and independent indicator for the prognosis of breast cancer in the training set (HR = 1.432; 95% CI 1.204-1.702, p < 0.001), validation set (HR = 1.162; 95% CI 1.004-1.345, p = 0.044), and whole set (HR = 1.240; 95% CI 1.128-1.362, p < 0.001). GSEA analysis revealed a strong connection between the signature and immune-related biological processes and pathways. CONCLUSIONS: We constructed and verified a robust signature of 8 immune-related lncRNAs for the prediction of breast cancer patient survival.

Stability and anion diffusion kinetics of Yttria-stabilized zirconia resolved from machine learning global potential energy surface exploration.

Yttria-stabilized zirconia (YSZ) is an important material with wide industrial applications particularly for its good conductivity in oxygen anion transportation. The conductivity is known to be sensitive to Y concentration: 8 mol. % YSZ (8YSZ) achieves the best performance, which, however, degrades remarkably under ∼1000 °C working conditions. Here, using the recently developed SSW-NN method, stochastic surface walking global optimization based on global neural network potential (G-NN), we establish the first ternary Y-Zr-O G-NN potential by fitting 28 803 first principles dataset screened from more than 107 global potential energy surface (PES) data and explore exhaustively the global PES of YSZ at different Y concentrations. Rich information on the thermodynamics and the anion diffusion kinetics of YSZ is, thus, gleaned, which helps resolve the long-standing puzzles on the stability and conductivity of the 8YSZ. We demonstrate that (i) 8YSZ is the cubic phase YSZ with the lowest possible Y concentrations. It is thermodynamically unstable, tending to segregate into the monoclinic phase of 6.7YSZ and the cubic phase of 20YSZ. (ii) The O anion diffusion in YSZ is mediated by O vacancy sites and moves along the ⟨100⟩ direction. In 8YSZ and 10YSZ, despite different Y concentrations, their anion diffusion barriers are similar, ∼ 1 eV, but in 8YSZ, the O diffusion distance is much longer due to the lack of O vacancy aggregation along the ⟨112⟩ direction. Our results illustrate the power of G-NN potential in solving challenging problems in material science, especially those requiring a deep knowledge on the complex PES.

Protective Effects of Oxymatrine on Vascular Endothelial Cells from High-Glucose-Induced Cytotoxicity by Inhibiting the Expression of A2B Receptor.

BACKGROUND/AIMS: Diabetes mellitus (DM) has become an increasingly epidemic metabolic disease. Vascular endothelial cells play a key role in developing the cardiovascular complications of DM. The A2B receptor is expressed in vascular endothelial cells, and may help regulate the function of endothelial cells. The aim of this study was to investigate the protective effects of oxymatrine (OMT) on human umbilical vein endothelial cells (HUVECs) from high glucose-induced cytotoxicity. METHODS: Homology modeling and molecular docking analysis were used to detect the binding sites between the adenosine A2B receptor and OMT. HUVECs were cultured with control (5.5 mM) or elevated glucose (22.2 mM) in the presence or absence of 3 µM OMT or A2B siRNA for 3 days. The MTS cell viability assay was used to measure the toxicity of high glucose on HUVECs and the protective effect of OMT or A2B siRNA. The expression of the adenosine A2B receptor and CCL5 in HUVECs was detected with real-time quantitative PCR (qPCR) and Western blotting methods in each group. Levels of IL-1ß and TNF-α were measured using an enzyme-linked immunosorbent assay (ELISA) kit, and the concentration of NO was detected with the nitrate reductase method. Monocyte chemotactic activity in each group was detected using Transwell chambers. Furthermore, the phosphorylation of p38 and ERK1/2 in each group was observed through the Western blotting method. RESULTS: Homology modeling and molecular docking analysis showed that OMT contains well-fitted binding sites to the A2B receptor. After chronic culture at high glucose, the rate of cell viability was significantly lower than that of the control group. After co-treatment with OMT or A2B siRNA, cell viability was significantly increased compared with the high-glucose group. The results from real-time quantitative RT-PCR (qRT-PCR) and Western blotting indicated that high glucose could increase the expression of A2B receptors in HUVECs, an effect that was inhibited by OMT. In addition, the results revealed that the expression of CCL5, IL-1ß and TNF-α was increased in the high-glucose group, and that the NO produced by HUVECs decreased due to hyperglycemia; however, co-culture with OMT or A2B siRNA abolished these effects. Meanwhile, the chemotaxis activity of monocytes to HUVECs cultured in high-glucose medium was enhanced 2.59-fold compared to the control cells. However, the inflammatory reactions in HUVECs were completely relieved by co-treatment with OMT or A2B siRNA. Moreover, the phosphorylation of p38 and ERK1/2 in HUVECs in the high-glucose group was significantly higher than that of the control group; these effects were reversed after co-treatment with OMT or A2B siRNA. CONCLUSION: OMT may protect the HUVECs from high glucose-induced cytotoxicity through inhibitting the expression of A2B receptor and inflammatory factors as well as decreasing the phosphorylation of p38 and ERK1/2.

MicroRNA-100 suppresses the migration and invasion of breast cancer cells by targeting FZD-8 and inhibiting Wnt/ß-catenin signaling pathway.

Wnt/ß-catenin signaling pathway plays a major role in the cancer metastasis. Several microRNAs (miRNAs) are contributed to the inhibition of breast cancer metastasis. Here, we attempted to find novel targets and mechanisms of microRNA-100 (miR-100) in regulating the migration and invasion of breast cancer cells. In this study, we found that miR-100 expression was downregulated in human breast cancer tissues and cell lines. The overexpression of miR-100 inhibited the migration and invasion of MDA-MB-231 breast cancer cells. Inversely, the downregulation of miR-100 increased the migration and invasion of MCF-7 breast cancer cells. Furthermore, FZD-8, a receptor of Wnt/ß-catenin signaling pathway, was demonstrated a direct target of miR-100. The overexpression of miR-100 decreased the expression levels not only FZD-8 but also the key components of Wnt/ß-catenin pathway, including ß-catenin, metalloproteniase-7 (MMP-7), T-cell factor-4 (TCF-4), and lymphoid enhancing factor-1 (LEF-1), and increased the protein expression levels of GSK-3ß and p-GSK-3ß in MDA-MB-231 cells, and the transfection of miR-100 inhibitor in MCF-7 cells showed the opposite effects. In addition, the expression of miR-100 was negatively correlated with the FZD-8 expression in human breast cancer tissues. Overall, these findings suggest that miR-100 suppresses the migration and invasion of breast cancer cells by targeting FZD-8 and inhibiting Wnt/ß-catenin signaling pathway and manipulation of miR-100 may provide a promoting therapeutic strategy for cancer breast treatment.

Parental support buffers the association of depressive symptoms with cortisol and C-reactive protein during adolescence.

Social experiences can affect the relationship between depression and physical health. The current study examined how social support from parents and friends may moderate the association of depressive symptoms with hypothalamic-pituitary-adrenal (HPA) axis activity and C-reactive protein among adolescents (N=316, Mage=16.40, SD=.74; 57% female) from diverse ethnic backgrounds (23.1% Asian, 29.1% European, 41.8% Latino, and 6.0% other backgrounds). Results indicated that parent support, but not friend support, moderated the link between depressive symptoms and both total daily cortisol output (a measure HPA activity) and C-reactive protein (a marker of inflammation). These patterns did not differ by ethnicity. Overall, the study highlights the continued, and perhaps accumulated, importance of parents during adolescence despite increasing needs for autonomy from and exploration outside of the family unit.

Everyday discrimination and diurnal cortisol during adolescence.

PURPOSE: To examine the associations of the frequency and type of everyday discrimination with diurnal cortisol and whether those associations depend upon adolescents' ethnicity and gender. METHODS: Adolescents (N=292, Mage=16. 39years, SD=0.74; 58% female) reported the frequency of perceived everyday discrimination and whether they attributed that discrimination to race, gender, age, or height and weight. Five saliva samples were collected per day across 3days and assayed for cortisol. RESULTS: Higher frequency of everyday discrimination was associated with greater total daily cortisol output (area under the curve; AUC), lower wake and bedtime levels of cortisol, and less of a decline in cortisol across the day. These associations generally did not depend upon ethnicity or gender and attributions for the discrimination were not as consequential as the actual frequency of any type of unfair treatment. CONCLUSION: Everyday discrimination, regardless of its type, may contribute to heightened HPA activity among adolescents of different ethnic backgrounds and genders.

Using intravoxel incoherent motion MR imaging to study the renal pathophysiological process of contrast-induced acute kidney injury in rats: Comparison with conventional DWI and arterial spin labelling.

OBJECTIVES: To investigate the potential of intravoxel incoherent motion (IVIM) to assess the renal pathophysiological process in contrast-induced acute kidney injury (CIAKI). METHODS: Twenty-seven rats were induced with CIAKI model, six rats were imaged longitudinally at 24 h prior to and 30 min, 12, 24, 48, 72 and 96 h after administration; three rats were randomly chosen from the rest for serum creatinine and histological studies. D, f, D* and ADC were calculated from IVIM, and renal blood flow (RBF) was obtained from arterial spin labelling (ASL). RESULTS: A progressive reduction in D and ADC was observed in cortex (CO) by 3.07 and 8.62 % at 30 min, and by 25.77 and 28.16 % at 48 h, respectively. A similar change in outer medulla (OM) and inner medulla (IM) was observed at a later time point (12-72 h). D values were strongly correlated with ADC (r = 0.885). As perfusion measurement, a significant decrease was shown for f in 12-48 h and an increase in 72-96 h. A slightly different trend was found for D*, which was decreased by 26.02, 21.78 and 10.19 % in CO, OM and IM, respectively, at 30 min. f and D* were strongly correlated with RBF in the cortex (r = 0.768, r = 0.67), but not in the medulla. CONCLUSIONS: IVIM is an effective imaging tool for monitoring progress in renal pathophysiology undergoing CIAKI. KEY POINTS: • IVIM analysis permits separate quantification of diffusion and perfusion. • IVIM can provide useful biomarkers ifor changes in renal pathophysiology. • IVIM can be useful for monitoring progress in renal pathophysiology undergoing CIAKI.

Anisotropic kinetics of solid phase transition from first principles: alpha-omega phase transformation of Zr.

Structural inhomogeneity is ubiquitous in solid crystals and plays critical roles in phase nucleation and propagation. Here, we develop a heterogeneous solid-solid phase transition theory for predicting the prevailing heterophase junctions, the metastable states governing microstructure evolution in solids. Using this theory and first-principles pathway sampling simulation, we determine two types of heterophase junctions pertaining to metal α-ω phase transition at different pressures and predict the reversibility of transformation only at low pressures, i.e. below 7 GPa. The low-pressure transformation is dominated by displacive Martensitic mechanism, while the high-pressure one is controlled by the reconstructive mechanism. The mechanism of α-ω phase transition is thus highly pressure-sensitive, for which the traditional homogeneous model fails to explain the experimental observations. The results provide the first atomic-level evidence on the coexistence of two different solid phase transition mechanisms in one system.

Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition.

Solid-to-solid phase transition, although widely exploited in making new materials, challenges persistently our current theory for predicting its complex kinetics and rich microstructures in transition. The Ga2O3α-ß phase transformation represents such a common but complex reaction with marked change in cation coordination and crystal density, which was known to yield either amorphous or crystalline products under different synthetic conditions. Here we, via recently developed stochastic surface walking (SSW) method, resolve for the first time the atomistic mechanism of Ga2O3α-ß phase transformation, the pathway of which turns out to be the first reaction pathway ever determined for a new type of diffusionless solid phase transition, namely, pseudomartensitic phase transition. We demonstrate that the sensitivity of product crystallinity is caused by its multi-step, multi-type reaction pathway, which bypasses seven intermediate phases and involves all types of elementary solid phase transition steps, i.e. the shearing of O layers (martensitic type), the local diffusion of Ga atoms (reconstructive type) and the significant lattice dilation (dilation type). While the migration of Ga atoms across the close-packed O layers is the rate-determining step and yields "amorphous-like" high energy intermediates, the shearing of O layers contributes to the formation of coherent biphase junctions and the presence of a crystallographic orientation relation, (001)α//(201[combining macron])ß + [120]α//[13[combining macron]2]ß. Our experiment using high-resolution transmission electron microscopy further confirms the theoretical predictions on the atomic structure of biphase junction and the formation of (201[combining macron])ß twin, and also discovers the late occurrence of lattice expansion in the nascent ß phase that grows out from the parent α phase. By distinguishing pseudomartensitic transition from other types of mechanisms, we propose general rules to predict the product crystallinity of solid phase transition. The new knowledge on the kinetics of pseudomartensitic transition complements the theory of diffusionless solid phase transition.

Energy Landscape of Zirconia Phase Transitions.

The solid-phase transitions of zirconia are important phenomena for many industrial applications. Because of the lack of tools for resolving the atom displacement pattern, the transition kinetics has been disputed for over 60 years. Here, first-principles-based stochastic surface walking (SSW) pathway sampling is utilized for resolving the mechanism of ZrO2 tetragonal-to-monoclinic solid-phase transition. Two types of lattice and atom correspondence allowed in phase transition are determined for the first time from energy criterion, which are originated from two nearly energy-degenerate lowest-transition pathways and one stress-induced ferroelastic transition channel of tetragonal phase. An orthorhombic crystal phase (Pbc2/1) is discovered to be a trapping state at low temperatures in phase transition, the presence of which does not create new orientation relation but deters transformation toughening significantly. This new finding may facilitate the design of new functional oxide materials in ceramic industry.

Overexpression of SMARCA5 correlates with cell proliferation and migration in breast cancer.

SMARCA5 partners with RSF-1 to compose the RSF complex, which belongs to the ISWI family of chromatin remodelers. Recent studies referred that SMARCA5 was overexpressed in some malignant tumors. However, expression pattern and biological roles of SMARCA5 in breast cancer have not been examined. In the present study, we found that SMARCA5 was overexpressed in breast cancer specimens by immunohistochemistry. Significant association was observed between SMARCA5 overexpression and TNM stage (p = 0.0199), tumor size (p = 0.0066), high proliferation index (p = 0.0366), and poor overall survival (p = 0.0141). SMARCA5 overexpression also correlated with Rsf-1 expression levels (p = 0.0120). Furthermore, colony formation assay and Matrigel invasion assay showed that knockdown of SMARCA5 expression in MDA-MB-231 and MDA-MB-435s cell lines with high endogenous expression decreased cell proliferation and cell invasion. Flow cytometry showed knockdown of SMARCA5-arrested cell cycle. Further analysis of cell cycle and invasion-related molecules showed that SMARCA5 downregulated cyclin A, MMP2 expression and upregulated p21 expression. In conclusion, our study demonstrated that SMARCA5 was overexpressed in human breast cancers and correlated with poor prognosis. SMARCA5 contributes to breast cancer cell proliferation and invasion.

CXCL12-CXCR4 axis promotes the natural selection of breast cancer cell metastasis.

CXCR4 and its ligand CXCL12 can promote the proliferation, survival, and invasion of cancer cells. They have been shown to play an important role in regulating metastasis of breast cancer to specific organs. High CXCR4 expression was also correlated to poor clinical outcome. Previous study also showed that tumor cells express a high level of CXCR4 and that tumor metastasis target tissues (lung, liver, and bone) express high levels of the ligand CXCL12, allowing tumor cells to directionally migrate to target organs via a CXCL12-CXCR4 chemotactic gradient. However, the exact mechanisms of how CXCR4 and CXCL12 enhance metastasis and/or tumor growth and their full implications on breast cancer progression are unknown. Yet it is likely that chemokine receptor signaling may provide more than just a migrational advantage by also helping the metastasized cells establish and survive in secondary environments. In this study, we investigated CXCR4 and CXCL12 expression in breast cancer and analyzed its association with clinicopathological factors by immunohistochemistry first. Then, we detected the mRNA and protein expression of CXCR4 and CXCL12 in breast cancer cell lines by Western blot and RT-PCR. The MDA-MB-231 has CXCR4 expression and very weak CXCL12 expression. So, we constructed the functional CXCL12 expression in MDA-MB-231 using a gene transfection technique. Further experiments were conducted to evaluate the effect of CXCL12 transfection on the biological behaviors of MDA-MB-231. The cell proliferation of MDA-MB-231-CXCL12 was accessed by MTT assay; the apoptosis was analyzed by an AnnexinV-FITC/propidium iodide double staining of flow cytometry method; and the cell invasive ability was examined by Matrigel invasion assay. Immunohistochemical analysis showed the co-expression of CXCR4 and CXCL12 correlated with lymph node metastasis and TNM stage (p < 0.01). It suggested that the chemokine CXCL12 and its sole ligand CXCR4 play important role in the malignance of breast cancer. To gain a deeper insight into it, we picked CXCR4-expressing cells MDA-MB-231 to be transfected with CXCL12 stably. The decreased cellular proliferation, increased apoptosis, and invasive ability were found in MDA-MB-231 with successful CXCL12 transfection (p < 0.05). Our findings underlined the CXCL12-CXCR4 axis correlated tightly with breast cancer metastasis. CXCL12-CXCR4 axis can increase the invasion and apoptosis of MDA-MB-231 simultaneously. These data strongly support the hypothesis that CXCL12-CXCR4 axis promotes the natural selection of breast cancer cell metastasis. Our findings could have significant implications in terms of breast cancer aggressiveness and the effectiveness of targeting the receptors and downstream signaling pathways for the treatment of breast cancer.