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Graphene-based nanomaterials possess broad applications because of their excellent multi-functional properties. In this work, a facile self-assembling method was presented for preparing one kind of graphene oxide-based paper/hollow microspheres hybrid. It was found that most of the hollow microspheres can strongly anchored on the surface of graphene oxide paper (GOP) by an in-situ scanning electron microscope peeling testing combining with molecular dynamics (MD) simulation. In addition, the uniform distribution of hollow microspheres on the surface of GOP cannot only provide a better surface wettability, but also can effectively improve the interfacial stress-transfer capability between such hybrid and polymer matrix. Our work provides a guidance for the structural designs of graphene-based nanomaterials and broaden their applications.

To study the influence of different concentrations of TGF-β_1 on the number and transdifferentiation of epithelial cells in endometrial tissue. 40 cases of normal endometrial tissue obtained by surgery in our hospital were collected, and epithelial cells were separated. According to the random number table method, cells were assigned into normal control groups (only with culture solution) and experimental groups (TGF-β1 was added on the basis of the above), the experimental group is further assigned into three groups, that is, low-dose (3 ng/ml), medium-dose (6 ng/ml) and high-dose (9 ng/ml) TGF-β_1 group followed by analysis of cell numbers, FN, α-SMA and Col-I level. FN secretion in normal control group was (0.469±0.010) ng/L, and ColI secretion was (0.532±0.033) ng/L. There was a difference between FN values and Col-I values in each experimental group (P < 0.01); α-SMA and other data in the experimental group had opposite effects compared with control group with significant differences for different concentrations of TGF-β_1. As concentration gradually increased, E-cadherin level in cytoplasm will gradually decrease. On the contrary, α-SMA level in cytoplasm will gradually increase (P < 0.05) (F = 145.125, 179.511, P < 0.01). TGF-β_1 stimulates the increase in of number of epithelial cells in endometrial tissue and induces them to transform into myofibroblasts dose dependently

Reducing the operating temperature of solid oxide fuel cells (SOFCs) has attracted worldwide attention in recent years. This has prompted massive efforts in developing new electrolyte materials for low-temperature SOFCs, typically including heterostructure materials consisting of semiconductors and ionic conductors. In this study, a p-n heterostructure (LiZnO–SnO2) and an n-n heterostructure (ZnO–SnO2) are proposed and evaluated in SOFCs to tap further the potential of a heterostructure for low-temperature electrolyte use. The results show that the developed LiZnO–SnO2 and ZnO–SnO2 both capably play competent electrolyte roles in SOFCs with high ionic conductivities and promising fuel cell performance, achieving peak power outputs of 376 and 255 mW cm−2 at 530 °C, respectively. To interpret the good performance of the two heterostructure electrolytes, energy band alignment mechanisms based on p-n hetero-junction and n-n heterostructure are employed to illustrate the ionic enhancement and electronic suppression processes of the materials. These findings reveal new insight into developing heterostructure electrolytes for low-temperature SOFCs.

Lowering the operational temperature of solid oxide fuel cells (SOFCs) is a vital research challenge for achieving broad commercialization of SOFCs. However, there is currently a lack of suitable electrolyte materials with sufficient ionic conductivity. In this review, the recent progress in semiconductor-ionic conductor composite strategies and related key technologies for low temperature SOFCs (LT-SOFCs) applications is highlighted, in particular, emphasizing the demonstration of such composite materials sandwiched between semiconductor electrodes in a symmetrical configuration that has delivered a potent solution. Despite the co-existence of electronic and ionic conduction in the composite membrane, no electronic short-circuiting was displayed, but rather an enhanced device power output was achieved. Here, the recent progresses in the development of SOFCs, from single-layer fuel cells, to two-phase semiconductor-ionic conductor membrane fuel cells with symmetrical electrodes, are discussed. This review will furnish researchers within the SOFC community and beyond with a broader understanding of the theory, development and significance of composite materials for LT-SOFCs.

Polyvinylidene fluoride (PVDF) is composited into electrolyte material, e.g., LaCePr-oxide-La0.6Sr0.4Co0.2Fe0.8O3-δ (LCP-LSCF), to improve its electrochemical performance and enhance its mechanical strength for a low-temperature solid oxide fuel cell. The influence of different PVDF contents on the performance of the as-prepared samples was studied in this work. X-ray diffraction results indicate that there is no impurity phase in the composite. Thermogravimetric analysis and differential scanning calorimetry were employed to investigate the composite’s stability at operating temperature. The I–V and I–P characteristics indicate that the microstructures of the nanocomposites that can be controlled by PVDF which plays an important role in its electrochemical performance. The cell with 3 wt% PVDF that was heat treated at 210 °C achieved the highest power density of 687 mW cm−2 at 550 °C, which was 196 mW cm−2 higher than that without any heat treatment. The pores are formed by PVDF, and the heat treatment enlarged the triple-phase boundary (TPB), which was the main reason for improved performance.

There is a rapid growing interest in low-temperature operation of solid oxide fuel cells (LTSOFCs). Recent advances in composited or doped CeO2 have resulted in high ion conductivity at low temperature below 600 °C. However, doped CeO2 faced reduced electronic conduction by fuel cell operation. In this study, we report a semiconductor heterostructure of CeO2–Fe2O3 for the electrolyte applications. We successfully developed high ionic conduction up to 0.18 S cm−1 while suppressing its electronic conduction following a good fuel cell demonstration of 403 mW cm−2 at 530 °C. The mechanism of ionic conduction and enhanced conductivity as well as suppression of electronic conductivity has been further investigated. Our findings demonstrate that the composite of the semiconductor heterostructure materials is a highly promising electrolyte for LTSOFCs.

Reducing the operating temperature of Solid Oxide Fuel Cells (SOFCs) to 300–600 °C is a great challenge for the development of SOFC. Among the extensive research and development (R&D) efforts that have been done on lowering the operating temperature of SOFCs, nanomaterials have played a critical role in improving ion transportation in electrolytes and facilitating electrochemical catalyzation of the electrodes. This work reviews recent progress in lowering the temperature of SOFCs by using semiconductor-ionic conductor nanomaterial, which is typically a composition of semiconductor and ionic conductor, as a membrane. The historical development, as well as the working mechanism of semiconductor-ionic membrane fuel cell (SIMFC), is discussed. Besides, the development in the application of nanostructured pure ionic conductors, semiconductors, and nanocomposites of semiconductors and ionic conductors as the membrane is highlighted. The method of using nano-structured semiconductor-ionic conductors as a membrane has been proved to successfully exhibit a significant enhancement in the ionic conductivity and power density of SOFCs at low temperatures and provides a new way to develop low-temperature SOFCs.

Recent advances have presented a promising p-n heterostructure strategy to develop highly ionic conducting electrolytes for low-temperature solid oxide fuel cells (LT-SOFCs). In this study, a p–n–n heterostructure approach is further proposed to develop new electrolytes for LT-SOFCs based on p-type Ni0.8Co0.15Al0.05LiO2−δ (NCAL), n-type ZnO, and n-type SnO2. Material characterization reveals that the developed NCAL-ZnO-SnO2 electrolyte gains a desirable heterostructure with homogenous distribution and hetero-interface as well as enriched oxygen vacancies. Electrochemical studies find that the electrical conductivity and fuel cell performance are significantly correlated with the mass ratios of p/n phases in the samples. The 2NCAL-1(ZnO-SnO2) exhibits a highest ionic conductivity of 0.389 S cm−1 at 530 ℃ along with a remarkable fuel cell power density of 1267 mW cm−2, which are apparently superior to those of p–n heterostructure electrolytes of NCAL-ZnO and NCAL-SnO2. By considering the semiconductor features of the used materials, further investigation in terms of energy band structure and rectifying characteristic studies indicate the possible existence of p-n-n heterojunction in the NCAL-ZnO-SnO2 fuel cell with rectifying behavior for charge carrier modulation. On basis of which, an energy band alignment effect is propounded to illustrate the electronic blocking and ionic acceleration processes of the p–n–n heterostructure electrolyte. The successful demonstration of 2NCAL-1(ZnO-SnO2) thus provides a new approach to develop advanced electrolytes for LT-SOFCs.

A novel semiconductor-ionic La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF)-Sm/Ca co-doped CeO2 (SCDC) nanocomposite has been developed as a membrane, which is sandwiched between two layers of Ni0.8Co0.15Al0.0 ...

Natural mineral, cuprospinel (CuFe2O4) originated from natural chalcopyrite ore (CuFeS2), has been used for the first time in low temperature solid oxide fuel cells. Three different types of devices are fabricated to explore the optimum application of CuFe2O4 in fuel cells. Device with CuFe2O4 as a cathode catalyst exhibits a maximum power density of 180 mW/cm2 with an open circuit voltage 1.07 V at 550 °C. And a power output of 587 mW/cm2 is achieved from the device using a homogeneous mixture membrane of CuFe2O4, Li2O-ZnO-Sm0.2Ce0.8O2 and LiNi0.8Co0.15Al0.05O2. Electrochemical impedance spectrum analysis reveals different mechanisms for the devices. The results demonstrate that natural mineral, chalcopyrite, can provide a new implementation to utilize the natural resources for next-generation fuel cells being cost-effective and make great contributions to the environmentally friendly sustainable energy.

In this study，nanocomposites of LaCePr-oxide (LCP) and Ni 0.8 Co 0.15 Al 0.05 LiO 2-δ (NCAL) with different contents of polyvinylidene fluoride (PVDF) were prepared and applied to solid oxide fuel cells. The composite materials were characterized by X-ray diffraction analysis (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and electrochemical impedance spectrum (EIS). The effect of PVDF concentration on the conductivity and performance of the fuel cells was investigated. It was found that PVDF plays a template role of pore forming in the nanocomposites, and the changed microstructure by as-formed pores greatly influences the electrochemical property of the nanocomposites. The cell with 3 wt% PVDF heat-treated at 210 °C achieved the highest power density of 982 mW cm −2 at 520 °C, which enhanced performance by more than 57% than when no heat-treatment was implemented. It is 66% higher than the cell with no PVDF and no heat-treatment. Pores formed by PVDF after heat-treatment enlarged the triple phase boundary (TPB), which results in improved fuel cell performance.

In the present work, we report a composite of industrial-grade material LaCePr-oxide (LCP) and perovskite La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF) for advanced electrolyte layer-free fuel cells (EFFCs). The microstructure, morphology, and electrical properties of the LCP, LSCF, and LCP-LSCF composite were investigated and characterized by XRD, SEM, EDS, TEM, and EIS. Various ratios of LCP to LSCF in the composite were modulated to achieve balanced ionic and electronic conductivities. Fuel cell with an optimum ratio of 60 wt% LCP to 40 wt% LSCF reached the highest open circuit voltage (OCV) at 1.01 V and a maximum power density of 745 mW cm −2 at 575 °C, also displaying a good performance stability. The high performance is attributed to the interfacial mechanisms and electrode catalytic effects. The findings from the present study promote industrial-grade rare-earth oxide as a promising new material for innovative low temperature solid oxide fuel cell (LTSOFC) technology.

In order to improve the catalytic activity of commercial Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) for low-temperature solid oxide fuel cells (LTSOFC) (300-600 degrees C), CoOx has been used to modify th ...

Conductive polyvinylidene fluoride(PVDF) matrix composites filled with graphited fiber(GF) or carbon fiber(CF) were prepared by the melt-mixing method. The breakage and length distribution of the fibers in the polymer matrix were studied by scanning electron microscope(SEM) and optical microscope(OM) observations, respectively. The differences in the positive temperature coefficient(PTC) effects of the composites were mainly attributed to inter-fiber contact ability. The elimination of the negative temperature coefficient(NTC) effect for CF/PVDF composite was because of an increase in the viscosity of the polymer matrix. With the same filler content, CF could be more effective, to eliminate the NTC effect when compared with GF. Addition of 2% CF(mass fraction) in the PVDF composite with 7% GF(mass fraction) could effectively eliminate the NTC phenomenon of the composite.

Human ileocecal adenocarcinoma cells HCT-8 were treated with RGD-containing cellular adhesion peptides including RGD, RGD(NH 2 ) 2 ( i.e. , RGE-NH 2 ), RGDS, and RGDS-NH 2 . MTT assay was prepared to examine their inhibiting effects on HCT-8 cells after treatment. The methods including Haematoxylin and Eosin(HE) staining, transmission electron microscopy(TEM), immunohistochemistry, flow cytometry, and Reverse Transcription-Polymerase Chain Reaction(RT-PCR) were used to observe the morphology of the apoptotic cells and analyze the mechanism of apoptosis. The experimental results indicate that RGD-containing cellular adhesion peptides can inhibit the growth and proliferation of tumor HCT-8 cells in a dose-dependent manner and induce the apoptosis of HCT-8 cells. At the same time, the high conservative property of RGD was confirmed again.

The thermal decomposition of Zn-MPA complex was investigated under microwave irradiation. ZnO and ZnS nanocrystals could be obtained by decomposing Zn-MPA(3-mercaptopropionic acid) complex under different reaction conditions. It was found that both the pH value of the solution and the molar ratio of Zn2+ and MPA can play an important role in the formation of ZnO and ZnS nanocrystals. MPA mainly acts as an S source or as a complexing agent. This study provides a new route for the controllable preparation of semiconductor nanocrystals.

This study aims at determining the therapeutic effect of knockdown of signal transducers and activators of transcription3(STAT3) gene expression by short interference RNA(siRNA) on transplanted Lewis lung cancer in mice in vivo. pSilencer 2.1-U6 STAT3 siRNA against STAT3(STAT3 siRNA) was synthesized. Lewis lung cancer cells were inoculated subcutaneously into C57BL/6 mice. Seven days after inoculation, the tumor-bearing mice were randomly divided into 3 groups and received intratumoral injection of (1) vehicle(PBS solution), (2) vector(negative control), and (3) STAT3 siRNA. Tumor volume and weight were calculated. Tumors and the lungs were excised for 21 days after inoculation. Expressions of STAT3, vascular endothelial growth factor(VEGF), and matrix metalloproteinase-2(MMP2) were analyzed by RT-PCR, Western blot, and immunohistochemical staining. HE staining and TUNEL assay were used to confirm the apoptosis of tumors. The synthetic STAT3 siRNA effectively suppressed tumor growth, prevented tumor from pulmonary metastasis, and induced tumor apoptosis in vivo compared with vehicle and vectore in controls. It significantly inhibited STAT3 expression to contribute to downregulation of VEGF and MMP2 expression within tumors in vivo. This study demonstrates that STAT3 siRNA can effectively inhibit the expression of STAT3 gene within tumors, leading to suppression of tumor growth, prevention of cancer from pulmonary metastasis, and enhancing apoptosis of the transplanted Lewis lung cancer in mice in vivo.

High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACET) and super conductive carbon black(HG-lP) as conductive filler, low-density polyethylene(LDPE) as the second component, ethylene-vinyl acetate(EVA) and ethylene propylene rubber(EPR) as the third component, azobisformamide(AC) as foamer, and dicumyl peroxide(DCP) as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene(HDPE)/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient(PTC) effect; whereas super conductive carbon black(HG-lP)-filled HDPE foaming conductive composite shows better negative temperature coefficient(NTC) effect.