Investigation of interaction effects on dual-frequency driven cavitation dynamics in a two-bubble system.

The cavitation dynamics of a two-bubble system in viscoelastic media excited by dual-frequency ultrasound is studied numerically with a focus on the effects of inter-bubble interactions. Compared to the isolated bubble cases, the enhancement or suppression effects can be exerted on the amplitude and nonlinearity of the bubble oscillations to different degrees. Moreover, the interaction effects are found to be highly sensitive to multiple paramount parameters related to the two-bubble system, the dual-frequency ultrasound and the medium viscoelasticity. Specifically, the larger bubble of a two-bubble system shows a stronger effect on the smaller one, and this effect becomes more pronounced when the larger bubble undergoes harmonic and/or subharmonic resonances as well as the two bubbles get closer (e.g., d0 < 100 µm). For the influences of the dual-frequency excitation, the results show that the bubbles can achieve enhanced harmonic and/or subharmonic oscillations as the frequency combinations with small frequency differences (e.g., Δf < 0.2 MHz) close to the corresponding resonance frequencies of bubbles, and the interaction effects are consequently intensified. Similarly, the bubble oscillations and the interaction effects can also be enhanced as the acoustic pressure amplitude of each frequency component is equal and the pressure amplitude pA increases. Above a pressure threshold (pA = 215 kPa), a larger bubble undergoes period 2 (P2) oscillations, which can force a smaller bubble to change its oscillation pattern from period 1 (P1) into P2 oscillations. In addition, it is found that the medium viscosity dampens the bubble oscillations while the medium elasticity affects the bubble resonances, accordingly exhibiting stronger interaction effects at smaller viscosities (e.g., µ < 4 mPa·s) or certain elasticities (approximately G = 70-120 kPa, G = 160-200 kPa and G = 640-780 kPa) at which the bubble resonances occur. The study can contribute to a better understanding of the complex dynamic behaviors of interacting cavitation bubbles in viscoelastic tissues for high efficient cavitation-mediated biomedical applications using dual-frequency ultrasound.

Energy minimization segmentation model based on MRI images.

Introduction: Medical image segmentation is an important tool for doctors to accurately analyze the volume of brain tissue and lesions, which is important for the correct diagnosis of brain diseases. However, manual image segmentation methods are time-consuming, subjective and lack of repeatability, it needs to develop automatic and reliable methods for image segmentation. Methods: Magnetic Resonance Imaging (MRI), a non-invasive imaging technique, is commonly used to detect, characterize and quantify tissues and lesions in the brain. Partial volume effect, gray scale in homogeneity, and lesions presents a great challenge for automatic medical image segmentation methods. So, the paper is dedicated to address the impact of partial volume effect and multiple sclerosis lesions on the segmentation accuracy in MRI. The objective function of the improved model and the post-processing method of lesion filling are researched based on the fuzzy clustering space and energy model. Results: In particular, an energy-minimized segmentation algorithm is proposed. Through experimental verification, the AR-FCM algorithm can better overcome the problem of low segmentation accuracy of the RFCM algorithm for tissue boundary voxels and improve the segmentation accuracy of this algorithm. Meanwhile, a multi-channel input energy-minimization segmentation method with lesion filling and anatomical mapping is further proposed. Discussion: The feasibility of the lesion filling strategy using post-processing can be confirmed and the segmentation accuracy is increased by comparison experiments.

Cell image reconstruction using digital holography with an improved GS algorithm.

Digital holography is an effective technology in image reconstruction as amplitude and phase information of cells can be acquired without any staining. In this paper, we propose a holographic technique with an improved Gerchberg-Saxton (GS) algorithm to reconstruct cell imaging based on phase reconstruction information. Comparative experiments are conducted on four specific models to investigate the effectiveness of the proposed method. The morphological parameters (such as shape, volume, and sphericity) of abnormal erythrocytes can be obtained by reconstructing cell hologram of urinary sediment. Notably, abnormal red blood cells can also be detected in mussy circumstances by the proposed method, owing to the significantly biophysical contrast (refractive index distribution and mass density) between two different cells. Therefore, this proposed method has a broad application prospect in cell image reconstruction and cell dynamic detection.

Being Negatively Cued, are People Less Cooperative? The Influence of Watching Eyes on Cooperative Behavior.

In the course of human evolution, watching eyes have had an important influence on individual cooperative behavior. However, researchers have not explored how the valence of watching eyes affects cooperative behavior. Therefore, this study includes three studies to investigate the effect of watching eyes with different valences on cooperative behavior. The results showed that positive watching eyes (vs. negative watching eyes) induced positive emotions (PA) in the participants and thus increased their tendency to cooperate (Studies 1-2). The role of the decision maker (making decisions for oneself vs. making decisions on behalf of others) moderates the effect of watching eyes on cooperative behavior through emotion (Study 3). In conclusion, the valence of watching eyes significantly affects cooperation. This study not only further enriches research on environmental stimulation and cooperation but also provides inspiration and a reference for solving problems of cooperation in social dilemmas.

The link between self-uncertainty and conspicuous consumption: Tolerance of uncertainty as a moderator.

This study, based on self-affirmation theory, aims to investigate the impact of self-uncertainty on individual consumption behavior. Self-uncertainty was categorized into moral, cognitive, and interpersonal self-uncertainty, and different types of self-uncertainty were manipulated through four experiments, including a moral dilemma, a recall paradigm, and a picture quiz task written by E-Prime software to examine the effects of different types of self-uncertainty on conspicuous consumption and their possible boundary conditions. Our results show that moral, cognitive, and interpersonal self-uncertainty contribute to a stronger tendency to engage in conspicuous consumption. Our results also suggest that tolerance of uncertainty moderates the effect of self-uncertainty on conspicuous consumption, meaning that subjects with a high tolerance of uncertainty are less inclined to engage in conspicuous consumption than those with a low tolerance of uncertainty, even if they have high self-uncertainty. This study may provide an explanation for conspicuous consumption behavior, further validating the theory of compensatory consumption. Additionally, the results from this study also provide a reference for understanding people's decision-making behavior in an uncertain social context and can provide new guidance to control irrational consumption behavior.

Procedural fairness predicts cooperative behaviour for high-self-esteem individuals but not for low-self-esteem individuals.

Cooperation is vital for modern society. Previous studies showed that procedural fairness promotes cooperation; however, they mainly focused on cooperation intention, which may fail to reveal actual cooperative behaviour. Moreover, little is known regarding the personality boundary of the effect of procedural fairness on cooperation. Guided by previous findings that self-esteem increases sensitivity to procedural unfairness, we attempted to explore the moderating effect of self-esteem on the association between procedural fairness and cooperative behaviour. In Experiment 1, 160 participants' self-esteem was measured using the Rosenberg Self-Esteem Scale; procedural fairness was manipulated in two conditions, depending on whether money was allocated in an economic game by rolling the dice twice or an allocator's arbitrary choice. Cooperative behaviour was assessed using the chicken game paradigm. Experiment 2 (148 participants) aimed to replicate and extend the results of Experiment 1 using a more rigorous experimental design, in which the possible effect of outcome favourability was excluded. The results of both experiments consistently showed that procedural fairness positively predicted cooperative behaviour, and this association was significant in high-self-esteem individuals, but not in low-self-esteem individuals. These findings shed light on the vital role of self-esteem in understanding the relationship between procedural fairness and cooperative behaviour.

Attachment style predicts cooperation in intuitive but not deliberative response in one-shot public goods game.

Cooperation is an important prosocial behaviour that is of great significance to individuals and society. The social heuristics hypothesis (SHH) systematically explains how cooperation is interactively affected by intuitive and deliberative processes. On the one hand, the intuitive process can be either cooperative or selfish, which is determined by previous experience. On the other hand, the deliberative process could support either a cooperative decision or a selfish decision, depending on which strategy could maximise the current payoff. This research aims to investigate the mechanism of cooperation. Attachment style was selected as a proxy for previous experience to examine whether and how previous life experience shapes intuitive response. Time constraint (Studies 1 and 2) and cognitive load (Study 3) were manipulated to dissociate the intuitive and deliberative processes. In addition, cooperation was assessed by adopting one-shot public goods games. Results showed that attachment avoidance (Studies 1, 2, and 3) and attachment anxiety (Study 3) significantly predicted cooperation in the intuition condition, whereas these associations were insignificant in the deliberation condition (Studies 1, 2, and 3). These findings provide further support for the SHH and shed new light on the mechanism of cooperation.

Powerful Individuals Behave Less Cooperatively in Common Resource Dilemmas When Treated Unfairly.

Previous research has suggested that power undermines cooperation in social dilemmas. However, the story may not be so simple. Guided by recent findings that power heightens sensitivity to unfairness, we examined the moderating effect of distributive justice on the association between power and cooperation. Across two experiments, when treated unfairly, high-power (vs. low-power) participants perceived greater unfairness. Moreover, high-power (vs. low-power) participants behaved less cooperatively not only when they interacted with the offender who treated them unfairly (Experiment 1), but also when they interacted with innocent third parties (Experiment 2). However, high-power and low-power participants showed no difference in perceived fairness and cooperation when treated fairly. These findings shed light on the association between power and cooperation by suggesting the modulating role of distributive justice, and they remind us that researchers should take participants' personal sense of power into account when manipulating fairness.

Why Does Advice Discounting Occur? The Combined Roles of Confidence and Trust.

Judges tend to discount the opinions of others even though advice is often helpful in improving their accuracy. The present research proposes that this phenomenon of advice discounting results from the judges' confidence in their initial decision and little trust in advice. Furthermore, the degree of advice discounting may be predicted by the combined roles of confidence and trust. Three studies provide evidence for these hypotheses. Participants were very confident in their initial estimation and had little trust in the advice (study 1). The degree of advice discounting decreased when participants felt less confidence in performing difficult tasks compared with easy tasks (study 2) or when participants placed more trust in advice because the advice was from an expert rather than from a novice (study 3). In addition, confidence and trust predicted the degree of advice discounting across three studies. These findings shed new light on the mechanism underlying advice discounting and advice taking by indicating the combined roles of confidence and trust.

Overexpression of Glutathione S-transferase P1 Inhibits the Viability and Motility of Prostate Cancer via Targeting MYC and Inactivating the MEK/ERK1/2 Pathways.

Prostate cancer (PC) is one of the most common malignancies of men. Glutathione S-transferase P1 (GSTP1) has been suggested to play a protective role in the prostate. The proto-oncogene MYC has been extensively proved to be a key regulator of tumor transformation from early stage to malignant. Our study aims to investigate the mechanism of GSTP1 in the biological behavior of PC. Compared with normal prostate tissues, the expression of GSTP1 was decreased in PC tissues. Conversely, the level of MYC was increased in PC tissues compared with normal tissues. MYC was convinced a direct target of GSTP1. Besides, the overexpression of GSTP1 or MYC siRNA strongly reduced cell viability via decreasing the volume of cell spheres and cell proliferation rate. GSTP1 overexpression or MYC siRNA also decreased cell motility of PC via reducing the closing rate of scratch wounds and the number of invasive cells. We further explored the underlying mechanism, and found that the level of p-MEK and p-ERK1/2 was strongly decreased in PC3 cells with pcDNA-GSTP1 or MYC siRNA transfection compared with control group. The inhibitory effect on cell viability, p-MEK and p-ERK1/2 was stronger when pcDNA-GSTP1 and MYC siRNA function together. Finally, the in vivo experiment displayed that pcDNA-GSTP1 transfection reduced tumor growth and tumor volume in PC xenografts. The decreased level of metastasis-related proteins VEGF (vascular endothelial growth factor) and MMP (metal matrix proteinase)-9 in GSTP1 overexpression model mice was detected by immunohistochemistry. Besides, the expression of MYC, p-MEK and p-ERK1/2 was strongly inhibited in mice with pcDNA-GSTP1 transfection. Taken together, our research indicates that GSTP1 overexpression inhibits the viability and motility of PC in vitro and in vivo, and may through targeting MYC and inactivating MEK/ERK1/2 pathway.

hsa-mir-3199-2 and hsa-mir-1293 as Novel Prognostic Biomarkers of Papillary Renal Cell Carcinoma by COX Ratio Risk Regression Model Screening.

Papillary renal cell carcinoma(PRCC) is the second most common and aggressive renal cell carcinoma. Identification of novel microRNA biomarkers could be beneficial for the diagnosis and prognosis of PRCC patients. We aimed to screen differentially expressed miRNAs that can act as prognostic factors and to predict the survival of PRCC patients. High-throughput data of miRNAs of 274 PRCC samples were downloaded from TCGA (The Cancer Genome Atlas) dataset and interested miRNAs were identified. Hierarchical clustering and principal component analysis (PCA) were performed on these miRNAs. Critical genes that can act as prognostic factors were screened by LASSO. What's more, Kaplan-Meier survival analysis and ROC (Receiver Operating Characteristic) growth curve were used to testify the accuracy of the model. Biological processes of putative targets of miRNAs were analyzed by bioinformatics methods such as GO (Go Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. A total of 105 differentially expressed miRNAs were screened out in PRCC samples compared with healthy controls. Two critical miRNAs, hsa-mir-3199-2, and hsa-mir-1293, were screened out by LASSO (Least Absolute Shrinkage and Selection Operator), including 197 and 189 target genes, respectively. Furthermore, its' accuracy was testified by ROC analysis with the AUC (Area under the curve) value of 0.7774968 and 0.6743466. These miRNAs were significantly enriched in pathways as platelet activating factor biosynthetic process, epithelial cell maturation, and IkappaB kinase complex. In conclusion, hsa-mir-3199-2 and hsa-mir-1293 that can act as prognostic biomarkers of PRCC were screened out, which can provide new insights for the clinical treatment of the disease. J. Cell. Biochem. 118: 3488-3494, 2017. © 2017 Wiley Periodicals, Inc.

Microfiber interferometric acoustic transducers.

Acoustic and ultrasonic transducers are key components in biomedical information technology, which has been applied in medical diagnosis, photoacoustic endoscopy and photoacoustic imaging. In this paper, an acoustic transducer based on Fabry-Perot interferometer (FPI) fabricated in a microscaled optical fiber is demonstrated. The transducer is fabricated by forming two wavelength-matched Bragg gratings into the microfiber by means of side illumination with a 193nm excimer laser. When placing the transducer in water, the applied acoustic signal periodically changes the refractive index (RI) of the surrounding liquid and modulates the transmission of the FPI based on the evanescent-field interaction between the liquid and the transmitting light. As a result, the acoustic signal can be constructed with a tunable laser whose output wavelength is located at the slope of the inteferometric fringes. The transducer presents a sensitivity of 10 times higher than the counterparts fabricated in conventional singlemode fibers and has great potential to achieve higher resolution for photoacoustic imaging due to its reduced diameter.

"Raisin bun"-like nanocomposites of palladium clusters and porphyrin for superior formic acid oxidation.

A novel "raisin bun"-like nanocomposite, where Pd clusters are embedded in porphyrin matrix, is developed as a promising electrocatalyst. Thanks to the synergy between the Pd clusters and the porphyrin matrix, this composite exhibits a low oxidation potential, high mass activity and excellent stability toward electrochemical oxidation of formic acid, which opens new routes for the design of high-performance catalysts in fuel cells.

Enhancement of ß-crystalline phase of poly(vinylidene fluoride) in the presence of hyperbranched copolymer wrapped multiwalled carbon nanotubes.

Many efforts have been performed on the poly(vinylidene fluoride), PVDF, due to its piezoelectric, pyroelectric and ferroelectric potentials. In this regard, how to fabricate the PVDF with high content of ß-phase, which is also the direct contribution to PVDF's prominent property, becomes a critical issue. In this study, starting with the α-phase dominated sample, the PVDF with extremely high content of ß-crystalline phase was obtained by the incorporation of multiwalled carbon nanotubes (MWCNTs) modified by hyperbranched copolymers (HBCs). We proved that, via XRD, DSC as well as the structural characterizations from the polarized optical microscopy and transmission electron microscopy (TEM), the success of this strategy was ascribed to the enhanced dispersibility and stability of MWCNTs endowed by the HBCs, which significantly favors the formation of the ß-crystalline phase of PVDF.

Synthesis and photobiological study of a novel chlorin photosensitizer BCPD-18MA for photodynamic therapy.

This paper reports synthesis and photobiological properties of a novel chlorin photosensitizer BCPD-18MA. Cytotoxicity, cellular uptake, subcellular location, biodistribution, photodynamic therapy (PDT) efficiency, cell apoptosis as well as histological analysis of the liposomal-delivered BCPD-18MA (L-BCPD-18MA) was studied using mammary adenocarcinoma MDA-MB-231 cells and Lewis lung carcinoma (LLC) implanted in C57BL/6 mice as experimental models. The results showed that L-BCPD-18 was incorporated rapidly into MDA-MB-231 cells and localized partially in mitochondria. L-BCPD-18 induced cell apoptosis by PDT. In addition, biodistribution of L-BCPD-18MA in LLC-bearing mice demonstrated a fast clearance rate of the drug and good skin-related tumor selectivity. Finally, entrapment of BCPD-18 into liposomes resulted in a dramatic impairment of dark toxicity and a notable improvement of PDT antitumor efficacy in vitro. Compared with liposomal-delivered BPDMA (L-BPDMA), L-BCPD-18MA exhibited low dark toxicity and high PDT efficiency on MDA-MB-231 cells. The photodynamic efficacy of L-BCPD-18MA on LLC-bearing mice is comparable to that of L-BPDMA, implying that L-BCPD-18MA is a potential antitumor candidate for PDT.

[Design of a half solenoid coil for optimization of magnetic focusing in trans-cranial magnetic stimulation].

Trans-cranial magnetic stimulation (TMS) is the process that excitable human brain tissue is activated with the electric field induced from a changing magnetic field. Magnetic focusing characteristic is one of the most important technical considerations of coil design in TMS. In this paper, a half solenoid coil was proposed to be used in TMS and the magnitude profile of the induced electric fields in different depth was studied based on the induced electric field theory of magnetic stimulating coil. The magnitude profile of the induced electric fields produced by half solenoid coils was compared with that of butterfly-shaped coils. The result shows that half solenoid coils retain the good focusing characteristics of the main lobe of the butterfly-shaped coils. At the same time side effect of the side lobes on notargeted tissue is mitigated, which would otherwise lead to undesirable stimulation. Hence magnetic focusing is optimized, which is expected to give a more accurate delivery of the focal point for more effective stimulation.