Carrier Transport and Molecular Displacement Modulated dc Electrical Breakdown of Polypropylene Nanocomposites

Dielectric energy storage capacitors have advantages such as ultra-high power density, extremely fast charge and discharge speed, long service lifespan and are significant for pulsed power system, smart power grid, and power electronics. Polypropylene (PP) is one of the most widely used dielectric materials for dielectric energy storage capacitors. It is of interest to investigate how to improve its electrical breakdown strength by nanodoping and the influencing mechanism of nanodoping on the electrical breakdown properties of polymer nanocomposites. PP/Al₂O₃ nanocomposite dielectric materials with various weight fraction of nanoparticles are fabricated by melt-blending and hot-pressing methods. Thermally stimulated current, surface potential decay, and dc electrical breakdown experiments show that deep trap properties and associated molecular chain motion are changed by incorporating nanofillers into polymer matrix, resulting in the variations in conductivity and dc electrical breakdown field of nanocomposite dielectrics. Then, a charge transport and molecular displacement modulated electrical breakdown model is utilized to simulate the dc electrical breakdown behavior. It is found that isolated interfacial regions formed in nanocomposite dielectrics at relatively low loadings reduce the effective carrier mobility and strengthen the interaction between molecular chains, hindering the transport of charges and the displacement of molecular chains with occupied deep traps. Accordingly, the electrical breakdown strength is enhanced at relatively low loadings. Interfacial regions may overlap in nanocomposite dielectrics at relatively high loadings so that the effective carrier mobility decreases and the interaction between molecular chains may be weakened. Consequently, the molecular motion is accelerated by electric force, leading to the decrease in electrical breakdown strength. The experiments and simulations reveals that the influence of nanodoping on dc electrical breakdown properties may origin from the changes in the charge transport and molecular displacement characteristics caused by interfacial regions in nanocomposite dielectrics.

Nitrogen-Doped Multi-Scale Porous Carbon for High Voltage Aqueous Supercapacitors

Recently, "Water-in-salt" electrolyte has been reported to extend the working voltage of aqueous supercapacitor. However, this electrolyte needs the electrode materials possess some good features such as proper pore structure, high electron and ion conductivity. Herein, we fabricated the nitrogen-doped multi-scale porous carbon (NMC) by the simple enriching melamine-resorcinol-formaldehyde xerogels method with integrating triblock copolymer for micro-pores formation. All the results confirmed that our NMC is provided with a very high specific surface area (3,170 m2 g-1) and its monoliths are composed of multi-scale porous structure. By employing the nanostructured NMC as electrode materials, we have investigated the capability for high-voltage aqueous supercapacitor applications. The superconcentrated "Water-in-salt" electrolyte expand stability operating potential window of aqueous symmetric supercapacitor up to 2.4 V with a high energy density of 33 Wh kg-1 at power density of 0.3 kW kg-1. Our studies indicate that the NMC is potential materials for high performance over wider voltage range.

Radiomics Nomogram Building From Multiparametric MRI to Predict Grade in Patients With Glioma: A Cohort Study

BACKGROUND

Accurate classification of gliomas is crucial for prescribing therapy and assessing the prognosis of patients.

PURPOSE

To develop a radiomics nomogram using multiparametric MRI for predicting glioma grading.

STUDY TYPE

Retrospective.

POPULATION

This study involved 85 patients (training cohort: n = 56; validation cohort: n = 29) with pathologically confirmed gliomas.

FIELD STRENGTH/SEQUENCE

1.5T MR, containing contrast-enhanced T₁ -weighted (CET₁ WI), axial T₂ -weighted (T₂ WI), and apparent diffusion coefficient (ADC) sequences.

ASSESSMENT

A region of interest of the tumor was delineated. A total of 652 radiomics features were extracted and were reduced using least absolute shrinkage and selection operator regression.

STATISTICAL TESTING

Radiomic signature, participant's age, and gender were analyzed as potential predictors to perform logistic regression analysis and develop a prediction model of glioma grading, and a radiomics nomogram was used to represent this model. The performance of the nomogram was assessed in terms of discrimination, calibration, and clinical value in glioma grading.

RESULTS

The radiomic signature was significantly associated with glioma grade (P < 0.001) in both the training and validation cohorts. The performance of the radiomics nomogram derived from three MRI sequences (with C-index of 0.971 and 0.961 in the training and validation cohorts, respectively) was improved compared to those based on either CET₁ WI, T₂ WI, or ADC alone in glioma grading (with C-index of 0.914, 0.714, 0.842 in the training cohort, and 0.941, 0.500, 0.730 in the validation cohort). The nomogram derived from three sequences showed good calibration: the calibration curve showed good agreement between the estimated and the actual probability. The decision curve demonstrated that combining three sequences had more favorable clinical predictive value than single sequence imaging.

DATA CONCLUSION

We created and assessed a multiparametric MRI-based radiomics nomogram that may help clinicians classify gliomas more accurately.

LEVEL OF EVIDENCE

4 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;49:825-833.

Fabrication of WO3·2H2O/BC Hybrids by the Radiation Method for Enhanced Performance Supercapacitors

In this study, we described a facile process for the fabrication of tungsten oxide dihydrate/bamboo charcoal hybrids (WO₃·2H₂O/BC) by the γ-irradiation method. The structural, morphological, and electrochemical properties of WO₃·2H₂O/BC hybrids were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and WO₃·2H₂O (pseudocapacitance) created a combined effect, which enhanced the specific capacitance and superior cyclic stability of the WO₃·2H₂O/BC hybrid electrode. The WO₃·2H₂O/BC hybrids showed the higher specific capacitance (391 F g⁻¹ at 0.5 A g⁻¹ over the voltage range from −1 to 0 V), compared with BC (108 F g⁻¹) in 6 M KOH solution. Furthermore, the hybrid electrode showed superior long-term performance with 82% capacitance retention even after 10,000 cycles. The experimental results demonstrated that the high performance of WO₃·2H₂O/BC hybrids could be a potential electrode material for supercapacitors.

A Novel Radiation Method for Preparing MnO₂/BC Monolith Hybrids with Outstanding Supercapacitance Performance

A novel facile process for fabrication of amorphous MnO₂/bamboo charcoal monolith hybrids (MnO₂/BC) for potential supercapacitor applications using γ-irradiation methods is described. The structural, morphological and electrochemical properties of the MnO₂/BC hybrids have been investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The combination of BC (electrical double layer charge) and MnO₂ (pseudocapacitance) created a complementary effect, which enhanced the specific capacitance and good cyclic stability of the MnO₂/BC hybrid electrodes. The MnO₂/BC hybrids showed a higher specific capacitance (449 F g⁻¹ at the constant current density of 0.5 A g⁻¹ over the potential range from –0.2 V to 0.8 V), compared with BC (101 F g⁻¹) in 1 M of Na₂SO₄ aqueous electrolyte. Furthermore, the MnO₂/BC hybrid electrodes showed superior cycling stability with 78% capacitance retention, even after 10,000 cycles. The experimental results demonstrated that the high performance of MnO₂/BC hybrids could be a potential electrode material for supercapacitors.

Immune-related proteins detected through iTRAQ-based proteomics analysis of intestines from Apostichopus japonicus in response to tussah immunoreactive substances

Apostichopus japonicus is a species of sea cucumber that is extensively bred as a marine delicacy because of its high nutritive and medicinal value. Immunostimulants are usually used to enhance the immunity of sea cucumber against diseases, but the physiological function of immunostimulants is poorly understood. In this study, we fed A. japonicus individuals with a diet supplemented with different concentrations of tussah immunoreactive substances (TIS), and then subjected their intestines to iTRAQ-based proteomic analysis. A total of 51 differentially expressed proteins were detected in response to TIS, 13 proteins were upregulated, while 38 proteins were reduced. These proteins are involved in phagocytosis, tissue protection, cell apoptosis and energy metabolism. Among these 51 proteins, 7 proteins (GLO2, ACOX, CTTN, MARK, FADD, CSTA and CASP6) related to immunity with functional annotation in sea cucumber were further analyzed. In addition, the upregulated expression of 4 immune-related proteins (GLO2, ACOX, CTTN and MARK) was validated by qRT-PCR. The findings of this study gave further insight into the mechanism by which TIS might enhance the immunity of A. japonicus.

In vitro functional characterization of prostaglandin-endoperoxide synthase 2 during chondrocyte hypertrophic differentiation

Cyclooxygenase 2 (Cox-2) has been implicated an essential role during bone repair, but the mechanisms remain elusive. Bone repair healing is known to include processes similar to endochondral ossification. In this study, we investigated the in vitro effect of Cox-2 on Col10a1 expression and chondrocyte hypertrophy, two critical components of endochondral ossification. Using quantitative RT-PCR, we detected increased mRNA levels of Cox-2 and Col10a1 in hypertrophic MCT cells, while cells treated with Cox-2 inhibitor, NS398, showed decreased mRNA and protein levels of Cox-2 and Col10a1. Increased Cox-2 also correlated with significantly upregulated Col10a1 in hypertrophic ATDC5 cells, whereas inhibition of Cox-2 significantly decreased Col10a1 expression. We further generated a Cox-2-expressing ATDC5 stable cell line. Compared with the controls, Cox-2 over-expression significantly increased Col10a1 as early as day 7 of continuous culturing, but not at days 14 and 21. Enhanced Alp staining was also observed in day 7 stable cell line. Correspondingly, we detected significantly increased levels of Runx2, Alp, Bcl-2, Bax, Col1a1, Osterix, and Bsp in day 7 stable line. Most of these genes have been associated with chondrocyte maturation and apoptosis. Together, our results support that Cox-2 promotes Col10a1 expression and chondrocyte hypertrophy in vitro, possibly through upregulation of Runx2 and other relevant transcription factors.

Protective efficacy of recombinant Cryptosporidium parvum CpPRP1 sushi domain against C. tyzzeri infection in mice

Until now, there are no completely effective parasite-specific pharmaceuticals or immunotherapies for treatment against the zoonotic cryptosporidiosis. Sushi domain (CpSushi) is an important functional domain in Cryptosporidium parvum putative rhoptry protein-1 (CpPRP1), which is the only reported C. parvum rhoptry protein and may play key role in the course of invasion. Here, a 708-bp fragment encoding the CpSushi domain was amplified and expressed in E. coli. Immunofluorescence detection showed that CpSushi was located on the surface of C. parvum oocysts and the apical pole to the sporozoites that belonged to the position of rhoptry. Three-week-old female ICR mice were used for detecting the immunoreactions and immunoprotection of recombinant CpSushi (rCpSushi) to artificial C. tyzzeri infection. The results indicated that a significant increase of anti-CpSushi antibody response was induced by the recombinant protein. Compared to blank, Tris-EDTA (TE) buffer and adjuvant controls mice, rCpSushi-immunized mice produced specific spleen cell proliferation as well as enhanced IL4, IL5, IL12p70 and TNF-α production in vitro. The reduction rate of parasites shedding in stool in mice immunized with rCpSushi was 68.91% after challenging with C. tyzzeri. These results suggest that CpSushi could be a new promising cryptosporidiosis vaccine candidate antigen composition.

URI promotes the migration and invasion of human cervical cancer cells potentially via upregulation of vimentin expression

URI is known to act as an oncoprotein in several tumors. Our previous studies have shown that URI is associated with the migration process in cervical and gastric cancer cells, but the mechanisms remain to be determined. Given the fact that URI positively regulates vimentin expression, we therefore investigated how URI regulated vimentin expression affects the migration and invasion of cells from two human cervical cancer cell lines HeLa and C33A, which differentially express URI. We have shown that knock-down of URI in HeLa cells using URI siRNA caused decreased vimentin mRNA and protein levels along with attenuated cell motility. Meanwhile, overexpression of URI by transfection of PCMV6-URI in C33A cells resulted in increased vimentin expression and enhanced cell migration and invasion. We have also used TGF-β to induce vimentin expression, which enhanced the cell migration and invasion abilities affected by URI, while inhibition of vimentin by siRNA attenuated URI's effect on cell migration and invasion. In addition, we have performed luciferase reporter and ChIP assays, and the results support that URI indirectly enhances the activity of vimentin promoter. Taken together, our results suggest that URI plays essential roles in the migration and invasion of human cervical cancer cells, possibly via targeting vimentin expression.

Effects of tussah immunoreactive substances on growth, immunity, disease resistance against Vibrio splendidus and gut microbiota profile of Apostichopus japonicus

Tussah immunoreactive substance (TIS) comprises a number of active chemicals with various bioactivities. The current study investigated the effects of these substances on the sea cucumber Apostichopus japonicus. The specific growth rate (SGR) of TIS-fed sea cucumbers was significantly enhanced, whereas no significant difference in SGR was observed between those soaked in antibiotics and those fed with basal diet only. TIS also improved the immune response of the animals when given at a dose of 1.0% or 2.0%, as shown by increased phagocytic, lysozyme, superoxide dismutase, alkaline phosphatase, acid phosphatase, and catalase activities following injection with live Vibrio splendidus. At a dose of 1.0% or 2.0%, TIS significantly enhanced the immune ability (P < 0.05) of the sea cucumbers, but except for lysozyme activity, other immune indices were reduced one day after the animals were injected with Vibrio splendidus. However, the values of these immune indexes were still significantly higher compared to those of the control groups (P < 0.05). Intestinal micro flora counts and high-throughput sequencing showed that dietary TIS could improve the amount of probiotic bacteria, yielding a 6-fold increase in Bacillus and 10-fold increase in Lactobacillus for sea cucumbers fed with 2.0% TIS diet compared to the control. Furthermore, TIS-containing diet also greatly reduced the number of harmful bacteria, with the number of Vibrio in sea cucumbers fed with 1%TIS diet decreased by 67% compared to the control. The results thus indicated that TIS increased the growth of sea cucumbers and enhanced their resistance to V. splendidus infection by improving the immunity of the animals. TIS also improved the gut microbiota profiles of the animals by increasing the probiotics and reducing the harmful bacteria within their guts.

T-box family of transcription factor-TBX5, insights in development and disease

The T-box gene family refers to a group of transcription factors that share a highly conserved, sequence-specific DNA-binding domain (T-box) containing around 180-amino acids. According to HUGO gene nomenclature committee (HGNC), there are 18 T-box family members. These T-box genes have been implicated essential roles during embryogenesis and cardiac development, given their specific expression pattern in developing mammalian heart for several T-box genes, including TBX5. TBX5 is consisted of three transcriptional variants which cover 9 exons and encode two distinct isoforms that differ in N-terminus. TBX5 is probably the most frequently studied T-box gene over the past decade due to the typical cardiac defects observed in Holt-Oram syndrome (HOS), which is caused by TBX5 mutation. Most of the mutations are within exons 3-7 where locate sequence coding for the T-box domain. Notably, a variety of cardiac defects, as well as abnormalities in limb and other organs have been seen in HOS syndrome with different kinds of TBX5 mutations, suggesting a heterogeneous disease mechanism. We have performed a meta-analysis of TBX5 and found a significant correlation between its single nucleotide polymorphism (SNP) rs3825214 (A to G), and risk of atrial fibrillation and its subtypes, supporting TBX5 as a master transcription factor for cardiac development. In addition, bioinformatics analysis of this SNP identified several TFs that may be affected for their binding affinity with TBX5. Identification and characterization of more TBX5 mutations and SNPs hold promise for therapeutic strategy targeting TBX5 associated developmental abnormalities and diseases.

Capacitive deionization of NaCl solutions with ambient pressure dried carbon aerogel microsphere electrodes

We first used carbon aerogel microspheres prepared via emulsion polymerization and ambient drying techniques as electrode material for capacitive deionization.

Runx2-interacting genes identified by yeast two-hybrid screening of libraries generated from hypertrophic chondrocytes

Runx2, a member of the Runt domain family, is a well-known master transcription factor for osteoblast differentiation. Runx2 has also been shown to play essential roles during chondrocyte hypertrophy, an important late stage of endochondral ossification linking both bone and cartilage development. To identify the co-factors that may interact with Runx2 together to regulate this critical process, we have performed yeast two-hybrid (Y2H) screening using Runx2 as a bait to screen a cDNA library of hypertrophic chondrocytes. The bait expressing cassette was constructed by fusing Runx2 with the pGBKT7 vector containing the Gal4 DNA binding domain (BD). The Mate & Plate libraries were constructed using pGADT7-Rec and cDNAs derived from hypertrophic chondrocytes enriched limb tissues or hypertrophic MCT cells. After co-transformation of pGBKT7-Runx2 and the cDNA libraries, colonies that grew in nutrition deficient medium were selected and subjected to PCR and sequencing analysis. We successfully identified more than 30 candidate genes, including Lectin-1 (Lgals1), Col1a2, Edf1 and Timp-2. We have performed literature review and bioinformatics analysis of these genes using GenePaint. Most of them show ubiquitous expression with Lgals1 show enhanced expression in hypertrophic chondrocytes. We further performed preliminary expression analysis by quantitative PCR and detected differential expression of these candidate genes in proliferative and hypertrophic MCT cells, with Timp-2 significantly (around 3-fold) and Lgals1 moderately (around 1.5 fold) upregulated in hypertrophic MCT cells. Our results suggest that, candidate gene Timp-2 is very likely to interact with Runx2 and together to play essential function during cartilage development, and possibly its homeostasis.

Relationship between adiponectin receptor 1 gene polymorphisms and ischemic stroke

OBJECTIVE

Previous study suggested adiponectin receptor 2 (ADIPOR2) genetic polymorphisms were associated with the risk of ischemic stroke. However, the relation between adiponectin receptor 1 (ADIPOR1) gene polymorphism and stroke remains unclear.

METHODS

In the present study, we utilized the polymerase chain reaction-sequencing method to detect rs2275737 and s1342387 genotypes of ADIPOR1 gene in 300 cases of ischemic stroke patients and 300 age- and sex- matched healthy controls.

RESULTS

For rs2275737, we found A allele carriers have increased risk to ischemic stroke (OR=2.570, 95% CI: 1.999-3.305); also, we found rs1342387 A allele was associated with the risk for stroke (OR=1.351, 95% CI: 1.074-1.699). After adjusted for confounders such as hypertension, diabetes, and smoking, we found the association remains significant.

CONCLUSION

ADIPOR1 genetic polymorphism may increase the risk of ischemic stroke.

Dietary Cordyceps militaris protects against Vibrio splendidus infection in sea cucumber Apostichopus japonicus

Vibrio splendidus is the common pathogen that causes infectious diseases widely spread in cultured sea cucumber in China. Therefore, we investigated the ability of Cordyceps militaris to protect against infection caused by V. splendidus. In this study, sea cucumbers were fed with a diet containing 0 (control), 1%, 2% or 3% C. militaris for 28 days, and subsequently challenged with V. splendidus by injection with 1.0 × 10(9) cfu per animal. Parameters of immune response such as phagocytosis (PC), lysozyme (LSZ) activity, superoxide dismutase (SOD) activity, alkaline phosphatase (AKP) activity and acid phosphatase (ACP) activity were determined on days 0, 1, 3, 5 and 7 after injection. The results showed that dietary C. militaris at a dose of 2% or 3% significantly up-regulated (P < 0.05) all the immune parameters on day 0. One day after injection with V. splendidus, all the immune indices except ACP exhibited a tendency to decrease and then increase again, returning to the initial level on days 5 and/or 7 after injection. All the immune parameters of those fed with C. militaris were found significantly higher (P < 0.05) than those of the control group on day 1 after injection. Only LSZ activity of those fed with 1%- or 3%-C. militaris diet on day 5 showed significantly increases (P < 0.05) than the controls. As for ACP activity, the values remained steady with time, but with significant increase (P < 0.05) seen in sea cucumbers fed with 2%-C. militaris diet, and lasted for up to 7 days after V. splendidus injection. The cumulative mortality of sea cucumbers fed with the basal diet followed V. splendidus infection was significantly higher (P < 0.05) than those fed with 2% and 3% C. militaris diet. Under the experimental conditions, dietary C. militaris could enhance the immune responses of Apostichopus japonicus and improve its resistance to infection by V. splendidus.

Hierarchical three-dimensional NiCo2O4 nanoneedle arrays supported on Ni foam for high-performance supercapacitors

A novel NiCo₂O₄ nanoneedle arrays with bottom crosslinked nanosheets grew on Ni foam as advanced binder-free electrodes via a facile one-step hydrothermal method followed by annealing in air, which exhibited high electrochemical performance.

A facile route to modify ferrous phosphate and its use as an iron-containing resource for LiFePO4 via a polyol process

This study introduces an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries via two processes: (1) the synthesis of LiFePO4/C cathode material using a low cost divalent precursor ferrous phosphate, Fe3 (PO4)2·8H2O, as iron source in a polyol process and (2) the modification of the morphology of this precursor by varying the reaction time in a coprecipitation process. The study examines the effects of different structures and morphologies of the precursor on the structure and electrochemical performance of the as-synthesized LiFePO4/C. The LiFePO4/C shows an excellent rate capability and cycle performance, with initial discharge capacities of 153, 128, and 106 mA h g(-1) at 1 C, 5 C, and 10 C. The capacity retention is respectively 98.7%, 98.2%, and 98.7%, after 10 cycles at the corresponding rates. The capacity retention remains at 97% even after 300 cycles at the rate of 10 C. The outstanding electrochemical performance can be attributed to the improved rate of Li(+) diffusion and the excellent crystallinity of synthesized LiFePO4/C powders through the modified precursor. Therefore, this is an economical and environmentally friendly way of synthesizing LiFePO4/C to be used as cathode material in lithium ion batteries.