Transient charge-driven 3D conformal printing via pulsed-plasma impingement.

Seamless integration of microstructures and circuits on three-dimensional (3D) complex surfaces is of significance and is catalyzing the emergence of many innovative 3D curvy electronic devices. However, patterning fine features on arbitrary 3D targets remains challenging. Here, we propose a facile charge-driven electrohydrodynamic 3D microprinting technique that allows micron- and even submicron-scale patterning of functional inks on a couple of 3D-shaped dielectrics via an atmospheric-pressure cold plasma jet. Relying on the transient charging of exposed sites arising from the weakly ionized gas jet, the specified charge is programmably deposited onto the surface as a virtual electrode with spatial and time spans of ~mm in diameter and ~µs in duration to generate a localized electric field accordantly. Therefore, inks with a wide range of viscosities can be directly drawn out from micro-orifices and deposited on both two-dimensional (2D) planar and 3D curved surfaces with a curvature radius down to ~1 mm and even on the inner wall of narrow cavities via localized electrostatic attraction, exhibiting a printing resolution of ~450 nm. In addition, several conformal electronic devices were successfully printed on 3D dielectric objects. Self-aligned 3D microprinting, with stacking layers up to 1400, is also achieved due to the electrified surfaces. This microplasma-induced printing technique exhibits great advantages such as ultrahigh resolution, excellent compatibility of inks and substrates, antigravity droplet dispersion, and omnidirectional printing on 3D freeform surfaces. It could provide a promising solution for intimately fabricating electronic devices on arbitrary 3D surfaces.

Amelanotic metastatic gastric malignant melanoma: a case report.

Melanoma is a malignant form of cutaneous cancer with an increasing incidence since 1970s, accounting for nearly 75% of the death related to skin cancer especially in western countries. Highest recurrence and mortality were observed for the subtype with distal metastasis, demonstrating poor outcomes. However, high incidence of gastrointestinal metastasis of malignant melanoma is frequently misdiagnosed due to lack of specific clinical manifestations, especially for the rare observed cases presented amelanotic appearance, accounting for about 2% of all metastatic cases. In the present study, we reported a 36-year-old male patient, who was firstly diagnosed as gastric cancer, and then was confirmed as amelanotic melanoma metastasis by pathological examination, demonstrating positive for melanoma markers including Melan A, S-100, Hmb45 and CD79a. In conclusion, for the amelanotic neoplasm observed during gastroscopy in patients with melanoma history, pathological examination should be carried out to confirm the possibility of melanoma metastasis, providing evidences for the following treatment.

Multiscale Study of the Charge Transport Properties of Silicone Rubber Oligomers.

Polymer dielectrics are widely used as insulation in electronic and electrical equipment. The charge transport process in polymer dielectrics under a high electric field, which is considered to result in electrical aging and even breakdown of equipment insulation, has attracted considerable attention. Based on a localized charge transfer model, the charge transport mechanism for typical silicone rubber (SR) insulating materials was studied by multiscale methods. A model of silicone rubber oligomers under standard conditions was generated by classical molecular dynamics. The frontier molecular orbitals and projected density of states for the SR oligomer were obtained via quantum chemistry methods. The electronic coupling, reorganization energy, and free energy difference for both electron and hole transfer processes between adjacent SR molecules in the molecular dynamics model were calculated. Both hole transfer and electron transfer in SR conform to an intermolecular hopping mechanism due to their high intramolecular reorganization energy and low intermolecular electronic coupling. The results of normal mode analysis for reorganization energy indicate that the high-temperature approximation holds for charge transport in SR around or above room temperature. The charge transfer trajectory and charge mobility in SR were simulated based on kinetic Monte Carlo simulations. The hole and electron mobilities at room temperature were calculated to be 7.24 × 10-11 and 2.76 × 10-9 cm2/Vs, respectively, which agrees with the experimental data. Both electron transport and hole transport in SR show thermal activation characteristics, with corresponding activation energies of 358 and 314 meV, respectively. This work suggests a physical model to describe the charge transport process in SR polymer dielectrics.

Study on the Long Bone Failure Behaviors Under the Indenter Rigid-Contact by Experiment Analysis and Subject-Specific Simulation.

The bending fracture behaviors of long bone have gained great attention due to the high bending fracture risk during sports events, traffic accidents, and falling incidents, etc. For evaluating bone bending behaviors, most of the previous studies used an indenter in three point bending experiments while the effect of its rigidity was never considered. In this work, using the porcine long bones, the three point bending tests were conducted to explore the bone fracture behaviors under a rigid indenter. In addition to collecting the force applied, the bone fracture dynamic process was recorded by high-speed photography, and the fracture surface profile in mesoscale was observed by the scanning electron microscope (SEM). Based on CT scanning of long bones, the cross section properties of test specimens were calculated by a homemade matlab script for correlating with their failure strengths. Also, a subject-specific finite element (FE) model was developed to identify the outcomes induced by a rigid indenter on simulation. Findings led to conclusions as follows: (1) The tension fracture came with fracture path deflection, which was caused by the bone indentation induced mesoscale crack-opening. Due to this damage before the whole bone fracture, a bone fracture moment correction was established to compensate experimental data. (2) The plastic indentation caused the force fluctuation as suggested by correlation analysis. (3) The bone failure moment correlated with the inertial moment of the bone cross section at the fracture location higher than the traditional cross section area. (4) In the subject-specific simulation, the indentation caused compression fracture under a much lower failure force. Removing the element erosion on the indenter-contacted area only during the validation was verified as a good option to solve this issue.

Neuropilin-1 is up-regulated by cancer-associated fibroblast-secreted IL-8 and associated with cell proliferation of gallbladder cancer.

We previously demonstrated that cancer-associated fibroblasts (CAFs) promoted the proliferation of gallbladder cancer (GBC) cells, but the mechanism is not clear. Neuropilin-1 (NRP-1) plays an important role in various malignancies as transmembrane glycoprotein. Our goal was to reveal the relationship between CAFs and NRP-1 and their potential functions in GBC. In this study, we found NRP-1 was overexpressed in GBC tissue, associated with poor survival and was up-regulated by CAFs. The cytokine array cluster analysis revealed IL-8 secreted by CAFs facilitated the up-regulation of NRP-1 in tumour cells. NRP-1 knockdown suppressed tumour growth in vivo. Gene expression microarray analysis showed 581 differentially regulated genes under NRP-1 knockdown conditions. Ingenuity pathway analysis demonstrated that NRP-1 knockdown may inhibit tumour progression by affecting cell proliferation. We then confirmed that NRP-1 knockdown in NOZ and GBC-SD cells significantly inhibited cell proliferation. Additionally, the IL-8 mediated MDM2 and CCNA2 expression were affected by NRP-1 knockdown. Our findings suggested that NRP-1 was up-regulated by CAF-secreted IL-8, which subsequently promoted GBC cell proliferation, and these molecules may serve as useful prognostic biomarkers and therapeutic targets for GBC.

Suppressor of Ty 16 promotes lung cancer malignancy and is negatively regulated by miR-1227-5p.

Suppressor of Ty 16 (Spt16) is a component of the facilitates chromatin transcription (FACT) complex, which is a histone chaperone and involved in gene transcription, DNA replication, and DNA repair. Previous studies showed that FACT is highly expressed in cancer, and cancer cells are more reliant on FACT than normal cells. However, the relationship between Spt16 and lung cancer remains unclear. In this study, we explored the functions of Spt16 in lung cancer cells. The effects of Spt16 on lung cancer cell proliferation, cell cycle progression, apoptosis, migration, and invasion were examined. We found that knockdown of Spt16 led to obvious decreases of both Rb and MCM7, and further activated the DNA damage response (DDR) pathway. In addition, a novel micro-RNA, miR-1227-5p, directly targeted the 3'-UTR of Spt16 and regulated the mRNA levels of Spt16. Furthermore, we found that CBL0137, the functional inhibitor of FACT, showed similar effects as loss of Spt16. Together, our data indicated that Spt16 is likely to be an essential regulator for lung cancer malignancy and is negatively regulated by miR-1227-5p.

Enhancing flashover performance of alumina/epoxy spacers by adaptive surface charge regulation using graded conductivity coating.

Surface flashover properties of alumina/epoxy spacers, involving a surface charge accumulation process, are critical for the safe and reliable operation of a high-voltage direct-current (HVDC) gas-insulated transmission line (GIL). This study reports surface charging behavior and flashover performance of alumina/epoxy spacers with different surface conductivity graded coating (SCGC) schemes in SF6/N2 mixtures under DC stress. Four kinds of SCGC schemes, i.e. localized coating near high voltage (HV-coating), near grounded electrode (GND-coating), at the middle of spacer surface (SPM-coating) and near both high voltage and grounded electrode (HV-GND-coating), are designed by partially spraying SiC/epoxy composites on the spacer surface. Surface charge distribution patterns exhibit varied features with different SCGC schemes. The HV-coating and GND-coating schemes lead to aggravated homo-charge and hetero-charge accumulation respectively, whereas in the SPM-coating scheme surface charge shows a multi-tier distribution pattern with alternating polarity. A transition of the dominant surface charge mechanism from bulk conductivity to surface conductivity with increasing conductivity on the coated area is found. Flashover performance differs a lot with different SCGC schemes: the HV-coating and HV-GND-coating schemes increase the flashover voltage while the SPM-coating and GND-coating schemes degrade it. The optimal surface insulation strength is achieved in the HV-coating scheme with a coating width of about 10 mm. The impact of different SCGC schemes on flashover performance is revealed based on the electric field analysis by considering the effect of surface charges.

The role of interfacial H-bonding on the electrical properties of UV-cured resin filled with hydroxylated Al2O3 nanoparticles.

Surface hydroxylation of crude Al2O3 (c-Al2O3) nanoparticles by H2O2 was conducted to tailor the electrical properties of UV-cured resin. The hydroxyl groups on Al2O3 particles were designed to establish hydrogen bonding between the hydroxyl and carboxyl groups, which favors the enhancement of interfacial strength between fillers and UV-cured resin matrix. The effect of interfacial strength on the electrical properties was investigated. Owing to the improved interfacial strength, it can be conjectured that a larger volume of the interaction zone exists in UV-cured resin/hydroxylated Al2O3 (UV/h-Al2O3) composites. As a consequence, the number of deeper traps is increased, restraining the charge migration and raising the charge injection barrier. Thus, UV/h-Al2O3 composites exhibit remarkably enhanced breakdown strength, improved volume resistivity and suppressed space charge accumulation in comparison with that of UV/c-Al2O3 composites at the same filler content. It was found that the addition of 0.5 wt% h-Al2O3 increases the AC breakdown strength and volume resistivity by 15.5% and 367.9%, respectively. Our results suggest that hydroxylation is an efficient way to improve the electrical properties of UV-cured resin nanocomposites, thus promoting stereolithography 3D printing in the application of electrical and electronic fields.

First-principles investigation of band offset and charge transfer characteristics at the PE/fluorinated layer interface.

Polymers, especially polyethylene (PE), are widely employed as insulating materials in electrical power transmission systems. However, the insulation still faces the problem of space charge, which distorts the electric field distribution and accelerates electrical aging. Experimental results show that after the fluorination process, less charge injection occurs compared with pure PE. To clarify the mechanism, classical molecular dynamics was employed to build a PE/fluorinated layer interfacial model and first principles calculation was utilized to get the band offset at the interface. The results calculated by both the bulk plus band lineup method and the layer-decomposed density of states method show that the energy band of the fluorinated PE layer is overall lower than that of the PE side, and the band offsets are around 2 eV. Charge transport results based on Marcus theory and kinetic Monte Carlo simulations also show that charge can easily accumulate at the interfacial area under an electric field and the band offset can suppress charge injection. The conduction band offset acts as an energy barrier for the excess electrons at the fluorinated layer side to cross the interface, while the valence band offset has the same effect on hole transport because of the energy barrier caused by the inverted region. Our findings provide a fundamental and theoretical basis for material modification and space charge inhibition.

Effect and mechanism of YB-1 knockdown on glioma cell growth, migration, and apoptosis.

Y-box binding protein 1 (YB-1) is manifested as its involvement in cell proliferation and differentiation and malignant cell transformation. Overexpression of YB-1 is associated with glioma progression and patient survival. The aim of this study is to investigate the influence of YB-1 knockdown on glioma cell progression and reveal the mechanisms of YB-1 knockdown on glioma cell growth, migration, and apoptosis. It was found that the knockdown of YB-1 decreased the mRNA and protein levels of YB-1 in U251 glioma cells. The knockdown of YB-1 significantly inhibited cell proliferation, colony formation, and migration in vitro and tumor growth in vivo. Proteome and phosphoproteome data revealed that YB-1 is involved in glioma progression through regulating the expression and phosphorylation of major proteins involved in cell cycle, adhesion, and apoptosis. The main regulated proteins included CCNB1, CCNDBP1, CDK2, CDK3, ADGRG1, CDH-2, MMP14, AIFM1, HO-1, and BAX. Furthermore, it was also found that YB-1 knockdown is associated with the hypo-phosphorylation of ErbB, mTOR, HIF-1, cGMP-PKG, and insulin signaling pathways, and proteoglycans in cancer. Our findings indicated that YB-1 plays a key role in glioma progression in multiple ways, including regulating the expression and phosphorylation of major proteins associated with cell cycle, adhesion, and apoptosis.

Identification of a diverse synthetic abietane diterpenoid library for anticancer activity.

A diverse natural-product-like synthetic abietane diterpenoid library contains about 56 compounds were obtained, and evaluated for their potential in vitro cytotoxic or antitumor activity against A549, PC-3 and SKOV-3 tumor cell lines by SRB assay. Treatment of A549 cells with the most potent compound ketone 19 showed induction of apoptosis, as revealed by JC-1 mitochondrial membrane potential staining, TUNNEL assay, western blotting analysis and flow cytometry assay.

Identification of a diverse synthetic abietane diterpenoid library and insight into the structure-activity relationships for antibacterial activity.

A diverse natural product-like (NPL) synthetic abietane diterpenoid library containing 86 compounds were obtained and the SARs were studied based on their antibacterial potential. Further in vitro cytotoxic and in silico drug-like properties evaluation showed that the potent antibacterial compound 84 had good drug-like properties and displayed low cytotoxicity toward noncancerous mammalian cells, indicating the study of AA and DHAA might be a good starting point for the search of novel antimicrobial molecules. Future work should be focused on the optimization of their potency and selectivity.

Lipoprotein lipase and phospholipid transfer protein overexpression in human glioma cells and their effect on cell growth, apoptosis, and migration.

Glioma is one of the common tumors in brain. The expression level of lipoprotein lipase (LPL) or phospholipid transfer protein (PLTP) may influence glioma progression and its relationship with clinical and pathological parameters. The clinical significance of LPL or PLTP expression in glioma has not been established. In the present study, the LPL and PLTP levels in glioma tumors were investigated and the relationship between the LPL and PLTP level and the grade of malignant glioma was analyzed, with the aim to provide new ideas for the diagnosis and treatment of gliomas in clinical and basic research settings. LPL and PLTP mRNA and protein levels were significantly higher in Grade IV glioma than those in the lower grade tumors (P < 0.01). Double immunofluorescent staining showed that the levels of LPL and PLTP were significantly associated with the pathological grade of glioma (P = 0.005). The levels of LPL and PLTP were increased with the shortened survival of glioma patients (P < 0.001). Knockdown of LPL and PLTP led to decreased cell growth and migration but increased apoptosis in vitro Additionally, cell cycle-related cyclins and their partners were found to be down-regulated while cyclin-dependent kinase inhibitors p16, p21, and Rb were up-regulated. Furthermore, knockdown of LPL or PLTP resulted in the up-regulation of pro-apoptotic molecules and the down-regulation of anti-apoptotic molecules. Ablation of LPL or PLTP in U251 cells resulted in the down-regulation of epithelial mesenchymal transition markers and invasion molecules matrix metalloproteinases. LPL and PLTP appear to be novel glioma-associated proteins and play a role in the progression of human glioma.

Interleukin-18 -137 G/C and -607 C/A polymorphisms and Alzheimer's disease risk: a meta-analysis.

The -137 G/C and -607 C/A polymorphisms in interleukin-18 (IL-18) gene have been reported to be associated with Alzheimer's disease (AD) risk, but the results are inconclusive. Considering a single study may lack the power to provide reliable conclusion, we performed a meta-analysis to investigate the association between the IL-18 -137 G/C and -607 C/A polymorphisms and AD susceptibility. A comprehensive literature search of PubMed, Embase, China National Knowledge Infrastructure (CNKI) and Wanfang databases were conducted before September 1, 2015. The pooled odds ratio (OR) with 95 % confidence intervals (CIs) were calculated. Five eligible studies with a total of 1536 subjects were finally included in this meta-analysis. For the IL-18 -137 G/C polymorphism, a significantly decreased risk was detected in patients carrying the C allele of -137 G/C in all study subjects in allele model (C vs. G: OR = 0.816, 95 % CI = 0.680-0.980, p = 0.029). Moreover, stratification by ethnicity indicated markedly association between the -137 G/C C allele and AD risk in Asians. For the IL-18 -607 C/A polymorphism, a significantly decreased risk was found in patients carrying the A allele of -607 C/A in all study subjects in dominant model (AA + CA vs. CC: OR = 0.696, 95 % CI = 0.529-0.915, p = 0.010). However, the results suggested no significant association between the -607 C/A polymorphism and AD susceptibility when stratified by ethnicity. Our present meta-analysis suggests that the C allele carrier of IL-18 -137 G/C was associated with decreased risk for AD in Asians. Further well-designed case-control studies with larger sample size and more ethnic groups are needed to confirm these conclusions.

Quantifying the Effects of Formalin Fixation on the Mechanical Properties of Cortical Bone Using Beam Theory and Optimization Methodology With Specimen-Specific Finite Element Models.

The effects of formalin fixation on bone material properties remain debatable. In this study, we collected 36 fresh-frozen cuboid-shaped cortical specimens from five male bovine femurs and immersed half of the specimens into 4% formalin fixation liquid for 30 days. We then conducted three-point bending tests and used both beam theory method and an optimization method combined with specimen-specific finite element (FE) models to identify material parameters. Through the optimization FE method, the formalin-fixed bones showed a significantly lower Young's modulus (-12%) compared to the fresh-frozen specimens, while no difference was observed using the beam theory method. Meanwhile, both the optimization FE and beam theory methods revealed higher effective failure strains for formalin-fixed bones compared to fresh-frozen ones (52% higher through the optimization FE method and 84% higher through the beam theory method). Hence, we conclude that the formalin fixation has a significant effect on bovine cortical bones at small, elastic, as well as large, plastic deformations.

Expression and significance of cortactin and HDAC6 in human prostatic foamy gland carcinoma.

Cortactin, the cytoplasmic substrate of HDAC6, is known to play an actin cytoskeletal regulatory role which is implicated in the motility of cancer cells, and thus in cancer progression. Its activity is found to be regulated by HDAC6. However, the significance of cortactin and HDAC6 remains unclear in uncommon histologic variant human prostatic foamy gland carcinoma (PfCa). In this study, we aimed to identify the expression and potential role of cortactin and HDAC6 in PfCa. Therefore, 16 PfCa specimens containing 48 foci with distinctive lesions were collected to identify the status of cortactin and HDAC6 by immunohistochemistry. Their correlation between clinicopathological characteristics and prognostic values were further analysed. The effect of cortactin and HDAC6 on prostate cancer cell migration and invasion was then evaluated in IA8 cells. The results showed that expression of cortactin and HDAC6 was significantly higher in PfCa foci, compared to that of high-grade prostatic intraepithelial neoplasia (HGPIN) foci and benign foci (P < 0.05). Cortactin and HDAC6 were associated with poor prognosis of patients with PfCa (P < 0.05). Multivariable Cox regression analysis showed HDAC6 level was a significant prognostic factor for survival of patients with PfCa (ß = 1.200, Wald value = 7.282, P = 0.007, 95% CI = 1.389-7.941, P < 0.01, ß > 0). Both knocking down cortactin and inhibition of HDAC6 activity with tubacin reduced in vitro migration and invasion ability of IA8 cells substantially. Furthermore, HDAC6 has prognostic value for patients with PfCa. Dysregulation of cortactin and HDAC6 is implicated in the invasiveness and migration of prostate cancer cells.

Association of human papillomavirus type 58 with breast cancer in Shaanxi province of China.

A number of reports have identified HPV DNA in breast cancer specimens and HPV type 16, 18, 31, 33, 45, and 51 were more prevalent. HPV 58 was frequently detected in cervical cancer in Shaanxi China. The aim of the present study was to investigate whether HPV 58 present in breast cancer. 169 cases of breast cancer samples and 83 benign breast lesions were analyzed. Type specific primers and oligonucliotide probe were used for the detection of HPV 58 by conventional PCR and in situ hybridization techniques. The HPV 58 viral load were measured by qPCR. p16 protein expression were evaluated by immunohistochemistry. HPV 58 E7 DNA was detected in 25 out of 169 formalin fixed paraffin embedded breast cancer tissues (14.79%) by PCR, only 1 out of 83 non-malignant breast lesions showed positive (1.20%). The results of ISH showed that 17 out of 169 (10.06%) malignant samples were positive for HPV 58 E7, and only 1 out of 83 non-malignant lesions was positive. Positive p16 immunostaining was observed in all the HPV 58 E7 ISH positive cases, but 16 out of 98 cases with HPV negative were p16 positive. The presence of HPV 58 in both normal duct epithelial cells and carcinoma in situ along with its presence in the cancer cells of the same specimen indicated the possible causal role of HPV 58 in breast cancer. The findings provide a solid morphological evidence of the involvement of HPV 58 in breast cancer development.

Dual effects of atmospheric pressure plasma jet on skin wound healing of mice.

Cold plasma has become an attractive tool for promoting wound healing and treating skin diseases. This article presents an atmospheric pressure plasma jet (APPJ) generated in argon gas through dielectric barrier discharge, which was applied to superficial skin wounds in BALB/c mice. The mice (n = 50) were assigned randomly into five groups (named A, B, C, D, E) with 10 animals in each group. Natural wound healing was compared with stimulated wound healing treated daily with APPJ for different time spans (10, 20, 30, 40, and 50 seconds) on 14 consecutive days. APPJ emission spectra, morphological changes in animal wounds, and tissue histological parameters were analyzed. Statistical results revealed that wound size changed over the duration of the experimental period and there was a significant interaction between experimental day and group. Differences between group C and other groups at day 7 were statistically significant (p < 0.05). All groups had nearly achieved closure of the untreated control wounds at day 14. The wounds treated with APPJ for 10, 20, 30, and 40 seconds showed significantly enhanced daily improvement compared with the control and almost complete closure at day 12, 10, 7, and 13, respectively. The optimal results of epidermal cell regeneration, granulation tissue hyperplasia, and collagen deposition in histological aspect were observed at day 7. However, the wounds treated for 50 seconds were less well healed at day 14 than those of the control. It was concluded that appropriate doses of cold plasma could inactivate bacteria around the wound, activate fibroblast proliferation in wound tissue, and eventually promote wound healing. Whereas, over doses of plasma suppressed wound healing due to causing cell death by apoptosis or necrosis. Both positive and negative effects may be related to the existence of reactive oxygen and nitrogen species (ROS and RNS) in APPJ.