Single-layer Cell Research Articles

Measurement of Chemical Potential in Bcy Electrolyte with Varying Thickness and Configuration Using Embedded Reference Electrodes

The correlation between internal chemical potential, and durability of anode-supported BCY (yttria-doped barium cerate) electrolyte cells, was investigated as a function of electrolyte thickness and configuration. Internal hydrogen and oxygen chemical potentials were measured using embedded Pt probes. As the electrolyte thickness decreased, the internal chemical potential became dominated by the gases surrounding the cathode, indicating that the thin BCY cell may be vulnerable to water vapor produced at the cathode during operation. BCY cells with BZY (yttria-doped barium zirconate) protecting at the cathode side (bi-layer cells) showed a small chemical potential variation through the electrolyte region close to the electrode side, indicating significant electronic conduction.Constant-current tests were conducted on thin (~ 10 µm) and thick (~ 35 µm) BCY single layer cells, and also on BCY-BZY bi-layer cells, especially under negative voltage conditions. Consistent with the results of the internal chemical-potential measurements, the thin BCY single layer cell showed a significant rate of degradation due to changes in BCY composition in the electrolyte and cathode, while the thick BCY single layer cell showed much better durability, regardless of the sign of cell voltage. The bi-layer cell was stably operated under any severe operating conditions, because of the BZY protecting layer against water vapor’s attack and its significant electronic conduction close to the cathode/electrolyte interface. Thus, the present work shows the effect of BCY electrolyte thickness and configuration on the durability of BCY based cells, in terms of their internal chemical potential.

Effect of Pressure on Lithium-Ion Battery Ageing

Lithium-ion batteries can age non-uniformly posing additional challenge in managing larger battery cells. For instance, a non-uniform distribution of solid electrolyte interphase (SEI) or plated lithium has been observed in cylindrical cells along the jelly roll length (1-2). The authors have suggested pressure distribution as a cause of this non-uniform ageing. This necessitates investigation of the effect of pressure on ageing. With different goals in mind, the effect of pressure on the rate of lithium-ion battery ageing has been studied previously (3-4).The work by Rubino et al.(3) indicates that the higher capacity fade in prismatic cells as compared to cylindrical cells of the same chemistry is due to the lower pressure in the former. However, the pressure was not a directly controlled parameter in this study. In contrast, the work by Arnold et al. (4) on commercial pouch cells shows that high stack pressure causes higher capacity fade, and that a small stack pressure is important to extend the life-time. However, the pouch cells were constrained along the thickness inducing non-uniform pressure on the different electrode layers and varying amplitudes of cyclic stack pressure during charge and discharge that is proportional to the external pressure. Hence, the above discrepancy of the effect of pressure calls for further investigation on ageing of model systems with single layer cells subjected to different levels of constant pressure. As an additional contribution, postmortem analysis is performed in order to understand how pressure level affects ageing mechanism.Here we present a study on commercial NMC positive and graphite negative electrodes in small laboratory pouch cells. The pouch cells are subjected to different stack pressure levels at controlled temperature using spring loaded stainless steel plates. Additionally, in order to monitor any differences in current distribution due to pressure and ageing, groups of cells are connected in parallel as the current distribution is measured using high precision shunt resistors and a Keithly differential multimeter. Capacity and impedance are measured periodically in order to track the performance changes with aging. A preliminary result indicates higher capacity fade in cells subjected to lower stack pressure. Results from EIS test indicate an increased ohmic resistance for high stack pressure cells, while low stack pressure cells show an increase in charge transfer resistance. Furthermore, different stack pressure on the cells of a parallel connected cell configuration results in current distribution with the cell subjected lower pressure taking slightly larger share of current. Details of the experimental techniques, and results from electrochemical and post mortem analysis will be presented and discussed during the meeting. Conclusions from this study will contribute to better understanding of the causes of non-uniform aging and suggestion for solutions to this problem through better cell design.

Oncocytic papillary renal cell carcinoma: A clinicopathological and genetic analysis and indolent clinical course in 14 cases

A sort of PRCC with distinct eosinophilic cytoplasm named Oncocytic Papillary Renal Cell Carcinoma (OPRCC) has been increasingly attracting the attention of researchers recently. However, owing to the rarity of OPRCC, the clinicopathological and genetic features of the tumor have still not been well elucidated and whether it should be regarded as an independent subtype of PRCC remains controversial. Herein, a cohort of 14 OPRCCs was studied with the aim of revealing the distinct clinicopathological features, facilitating the classification and correct diagnosis of OPRCC. Men and women each accounted for a half of the cohort with the median age of 64 years old. The majority of patients (9/14) were identified by medical examination and the remaining presented with macroscopic haematuria or lumbar pain. Grossly, tumors were well demarcated and varied from 1.5 to 9cm in diameter. Microscopically, typical OPRCC possessed fine papillary structures with delicate fibrovascular cores, lined with a single layer cell with large, deeply eosinophilic granular cytoplasm and round or polygonal-shaped nucleus exhibiting low nuclear grade in 10 cases (WHO/ISUP grade I-II). Most cases (12/14) possessed hemosiderin-laden and foam-like cells. Focal necrosis presented in 5 cases. Furthermore, solid oncocytoma-like areas appeared in 5 cases and focal sarcomatoid differentiation was identified in 1 case. Immunohistochemically, the majority of tumors presented high expression rates of alpha-methylacylCoA racemase (AMACR), CD10 and vimentin, which were similar to type 2 PRCC. The immune markers including cytokeratin-7 (CK7), KSP-cadherin and EMA exhibited variable positive immunostaining. Genetically, FISH analysis demonstrated trisomy of chromosome 7 in 7 OPRCCs and trisomy of chromosome 17 in 6 OPRCCs. Among 7 male cases, loss of chromosome Y was revealed in 2 cases. Follow-up data was available in 13 patients and only 1 patient died of bone metastasis of the tumor. The other 12 patients were all alive uneventfully at a mean follow-up time of 37 months, indicating that OPRCC is a unique subtype of PRCC with indolent clinical behavior. In conclusion, OPRCCs show a single layer tumor cell of low nuclear grade similar to type 1 PRCC, and abundant eosinophilic cytoplasm resembling type 2 PRCC. Furthermore, the tumor presents the same immunophynotype as type 2 PRCC but the same genetic features and prognosis as type 1 PRCC. OPRCC should be classified as an independent subtype of PRCC with different features from both type 1 and type 2 PRCC.

Design of an Automated System for the Evaluation of Materials for Battery Research

During the development of new materials for battery production the produced materials have to be evaluated. Usually several single-layer battery cells of the developed material are assembled manually and characterized electrochemically. The results depend very largely on the manual assembly where an amount of random deviations tolerances affect the performance of the product (e.g. alignment of the electrodes or electrolyte filling).In this contribution possible sources of errors of the manual assembly are analyzed and a conceptual design of a new assembly system for a variant flexible and size-adapted automated system for the use in compact environments is created.

Phenyl substitution of cationic bis-cyclometalated iridium(iii) complexes for iTMC-LEECs

A series of seven cationic bis-cyclometalated iridium(iii) complexes of the form [(C^N)2(N^N)Ir][PF6] has been designed in order to examine the effect of bulky, hydrophobic phenyl substituents on the structure-property relationship of these ionic transition metal complexes (iTMCs) in light-emitting electrochemical cells (LEECs). Capping phenyl substituents on the cyclometalating and ancillary ligands allows for individual tuning of the HOMO and LUMO energy levels, respectively, yielding an emission range from yellow to red. The complexes in this series exhibit increased quantum yields, up to 70% higher than the unoptimized, archetypal [(2-phenylpyridine)2(2,2'-bipyridine)Ir][PF6]. Among these, one complex, C3, was recently reported to produce devices with superior luminance and efficiency. Simultaneous measure of the series of complexes enabled the clear discernment of trends in device performance connected to fundamental structure-property relationships that elucidate the origin of enhanced luminance. In general, phenyl substitution of the 2-phenylpyridine ligands of the parent complex produced higher luminance and faster device response than phenyl substitution of the 2,2'-bipyridine ligand. Overall, complex design and device engineering produce competitive LEECs from simple, single-layer architectures. The synthesis, crystallographic, photophysical, and electrochemical properties of the iTMCs, along with the electroluminescence properties of the LEEC devices are reported herein.

Safety and efficacy of a novel Prunus domestica extract (Sitoprin, CR002) on testosterone-induced benign prostatic hyperplasia (BPH) in male Wistar rats

The efficacy of a novel Prunus domestica bark extract (Sitoprin, CR002) was investigated on testosterone propionate (TP)-induced benign prostatic hyperplasia (BPH) in male Wistar rats. BPH was induced by daily subcutaneous administration of TP (3.0 mg/kg) over a period of 15 days (interim sacrifice group) and for an additional 21 days (terminal sacrifice group). We evaluated the dose-dependent efficacy (0, 50, 100 and 200 mg/kg body weight/day) of CR002 and a control group against BPH, and compared with a reference standard Prunus africana extract (CR001). Extensive clinical examinations were carried out on days 1, 7, 14, 21, 28 and 35 of treatment period to determine the onset, duration and severity of clinical signs. Clinical pathology, hematology, biochemistry and histopathology were performed on days 15 and 35, prior to necropsy. Animals were fasted overnight prior to blood collection. Prostate glands and tissues were examined. On day 36, histopathology of ventral prostrate of control rats demonstrates single layer of columnar mucin secreting epithelial cells along with a lumen occupied with eosinophilic secretion. In contrast, CR002 and CR001 groups (100 and 200 mg/kg/day) exhibited no hyperplasia and proliferation of epithelial cells. Prostate histopathology of these treated groups was comparable with control rats. The hyperplasia and hypertrophy of prostrate was reduced to single-layered cell indicating the efficacy of CR002 and CR001. Overall, results demonstrate that CR002 exhibits therapeutic efficacy/activity in TP-induced BPH in rats, which is comparable to CR001.

Photovoltaic properties of Zn, Al, La, Sm, and Yb complexes with o-iminobenzoquinone ligands

The o-iminobenzoquinone complexes of lanthanum, samarium, and ytterbium, Ln(L)3 (L = 3,5-ditert- butyl-1,2-quinone-1-(2-oxy-3,5-di-tert-butylphenyl)imine) are synthesized. In order to study the photovoltaic properties of the obtained complexes and previously synthesized similar complexes of zinc and aluminum M(L)2 prototypes of photovoltaic cells are prepared on their basis. An examination of the fabricated devices has revealed that nanolayers of all the compounds, except for ytterbium complex, exhibited photovoltaic properties. The best results of energy conversion are achieved for single-layer cells containing zinc complex as a photoactive material (Open-circuit voltage U OC = 1.01 V, short-circuit current J SC = 5.2 nA/cm2).

Resistive switching characteristics of Si3N4-based resistive-switching random-access memory cell with tunnel barrier for high density integration and low-power applications

In this letter, a bipolar resistive-switching random-access memory (RRAM) in Ni/Si3N4/SiO2/p+-Si structure and its fabrication process are demonstrated. The proposed device with double-layer dielectrics consisting of Si3N4 layer (5 nm) as a resistive switching and SiO2 (2.5 nm) layer for the tunnel barrier is investigated in comparison with that having a single layer of Si3N4. Double-layer cell shows ultra-low power operation under a compliance current (ICOMP) of 500 nA, which ensures the reset current (IRESET) of sub-1 μA much lower than that of the single-layer cell. Also, large on/off ratio (∼105) has been obtained since the SiO2 layer efficiently suppresses the current in the high-resistance state. Moreover, maximum selectivity in double-layer cell is 122 when 1/2 read bias scheme is applied to the crossbar array. Highly nonlinear I-V characteristics of the double-layer Si3N4-based RRAM cell warrant the realization of selector-free RRAM cell in the crossbar array pursuing higher integration density.

12V-Class Bipolar LiMn1-YFeyPO4 /Li4Ti5O12 Battery with an Oxide-Based Solid-State Electrolyte Layer

Lithium batteries are capable of a high energy density, high power, and long cycle performance. Demand for lithium-ion batteries has increased for applications ranging from portable devices to large machines such as electric vehicles and energy storage for load leveling. Especially, a high voltage of the battery system is required for these large-scaled applications. However, we can use only around 3.7 V from a conventional monopolar-type lithium-ion battery, and are required to connect in series for the high-voltage systems. To overcome these problems, a bipolar-type cell [1] is considered to be one of the suggestions for improvement the cell voltage. Using solid-state electrolyte makes it possible to fabrication the bipolar batteries without a porous film separator and partitions to avoid liquid junction. The solid-electrolyte, for example, Li2S-P2S5 glass-ceramics[2], LiSICON[3], perovskites[4] and garnets have been investigated to improve an ionic conductivity at RT. The cubic garnet-type with a nominal composition of Li7La3Zr2O12 (LLZ) [5] has high ionic conductivities (2.4×10-4 Scm-1 at RT) and a wide electrochemical window. On the other hand, difficulty of forming an effective electrode-electrolyte interface is known as problems of all-solid-state lithium-ion batteries. Forming a favorable electrode-electrolyte interface by interfacial modification has effectively decreased the interfacial resistance. In this study, we tried to use a lithium-ion conductive binder as buffer layer on active materials and LLZ for improving Li+ ion diffusion in electrode-electrolyte interface. Olivine LiMn1-yFeyPO4 (LMFP) has been studied as a potential 4V-class cathode with high thermal stability compared to such as LiCoO2, LiNi1/3Co1/3Mn1/3O2, and LiMn2O4. Spinel Li4Ti5O12 (LTO) has advantages of a zero strain property, the suppression of internal short-circuit reaction[6], high power, and long-life performance[7] for the anode in the bipolar battery with the solid-state electrolyte. Li-ion cell with a combination of the LMFP cathode and the LTO anode shows a voltage plateau of 2.5V for Mn3+/Mn2+ redox[8]. 5 series LMFP/LTO cell has a good harmonization with 12V battery system. Current collectors for the LMFP cathode and the LTO anode can be used as the same aluminum foil, which becomes easy to make bipolar electrodes. We thus fabricated 12V-class bipolar LiMn0.8Fe0.2PO4/ LTO battery with the LLZ solid-electrolyte layer, which based on a composite electrode composed of active materials and LLZ coated with a lithium-ion conductive binder, and this single-layered electrode cell takes out 2.5 V. The bipolar batteries were constructed from five cells stacked together, which contained four bipolar electrodes and two monopolar electrodes as endplates to obtain output voltage of 12 V. Cathodes and anodes in bipolar batteries are disposed in contact respectively with opposite sides of a common current collecting element forming a unitary bipolar structure. The LLZ powders were synthesized by solid phase process and synthesized particles were crushed into smaller sizes by bead milling. After mixing LLZ powders and lithium-ion conductive binder, the mixture sprayed and deposited on each electrode. The layer of LLZ powders between the anode and the cathode is working as not only the electrolyte but also as an ionic conductive separator After LLZ powders deposited, cross-sectional SEM image of LLZ/LTO is shown in Fig. 1. Particle diameter of LLZ powders is < 1mm by bead milling process. Electrode- electrolyte interface has effectively pasted up using binder and peeling was not observed. Thickness of LLZ layer, LMP layer, and LTO layer were 20, 60 and 60 mm, respectively. Total thickness of the bipolar battery was 570 mm. Fig. 2 shows fcharge and discharge curves of the bipolar LMFP/Li4Ti5O12 battery at the first cycle and 25°C. The bipolar battery shows the discharge curve has a high voltage slope at 12V corresponding to 2.4V for a single cell and has a capacity of 5mAh. The result of other electrochemical tests of bipolar LMFP/Li4Ti5O12 batteries will be also reported.

Degradation Study of Yttria Doped Barium Cerate (BCY) Electrolyte in Protonic Ceramic Fuel Cells Under Various Test Conditions

Acceptor-doped barium cerate has been considered as a potential electrolyte material in solid oxide fuel cell because of its high proton conductivity at temperatures below 7000C. However, despite its superior transport property, barium cerate cannot be practically used in fuel cell due to its poor chemical stability in the atmosphere of water vapor and carbon dioxide. In the present work, we fabricated two kinds of BCY based anode supported cells, 1) BCY single layer cell and 2) BCY/BZY bi-layer cell, and their stability and degradation mechanism were investigated and compared, especially under severe operating conditions such as a negative voltage and low air flow rate. Constant current (CC) tests were conducted on the cells under various operating conditions such as positive vs. negative cell voltage and high vs. low fuel/air flow rate. Constant current (CC) tests were conducted on the BCY single layer and BCY/BZY bi-layer cells under a negative well as well a positive cell voltage as a function of air flow rate. Before and after the CC tests, I-V curve and impedance spectra were measured and compared to trace any increase in ohmic and/or non-ohmic resistance of the cells. Post-material analyses were conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) to find out any change in microstructure and phase after severe operations.

Efficacy of Novel Pygeum Extract (CR002) on Testosterone‐Induced Benign Prostatic Hyperplasia (BPH) in Male Wistar Rats

The efficacy of a novel Prunus domestica extract (pygeum extract, CR002) was investigated on testosterone propionate (TP)‐induced BPH in male Wistar rats. BPH was induced by subcutaneous administration of TP (3.0 g/kg) over a period of 15 days (interim sacrifice group) and for 21 days (terminal sacrifice group). We evaluated the dose‐dependent efficacy (0, 50, 100 and 200 mg/kg body weight/day) of novel Prunus domestica extract (CR002) and a control group against BPH, and compared with a reference standard Prunus africana extract (CR001). Extensive clinical examinations were carried out on days 1, 7, 14, 21, 28 and 35 of treatment period to determine the onset, duration and severity of clinical signs. Clinical pathology, hematology, biochemistry and histopathology were performed on days 15 and 35, prior to necropsy. Animals were fasted overnight prior to blood collection. Prostate glands and tissues were examined. On day 36, histopathology of ventral prostrate of control rats demonstrate single layer of columnar mucin secreting epithelial cells and lumen was occupied with eosinophilic secretion. In contrast, CR002 and CR001 groups (100 and 200 mg/kg/day) exhibited no hyperplasia and proliferation of epithelial cells. Prostate histopathology of these treated groups was comparable with control rats. The hyperplasia and hypertrophy of prostrate was reduced to single layered cell indicating the efficacy of CR002 and CR001. Overall, results demonstrate that CR002 exhibits therapeutic efficacy/activity in TP‐induced BPH in rats, which is comparable to CR001.

Development of High-Pressure ESR System Using Micro-coil

We have developed the high-pressure electron spin resonance (ESR) system using a micro-coil in the frequency region up to around 2 GHz and potentially 10 GHz. The hybrid-type piston-cylinder pressure cell whose maximum pressure reaches 4 GPa was used. In this study, we obtained ESR spectra at 2.3 GPa successfully, which can never be obtained by the single-layer piston-cylinder pressure cell. The minimum detectable spin number was estimated to be the order of 1012 spins/G. Moreover, it is shown that the sensitivity can be improved by two orders of magnitude using the field modulation technique. This high-pressure ESR technique is a promising one to achieve the sensitivity and the high pressure simultaneously.

Atomic force microscopy based nanoindentation study of onion abaxial epidermis walls in aqueous environment

An atomic force microscopy based nanoindentation method was employed to study how the structure of cellulose microfibril packing and matrix polymers affect elastic modulus of fully hydrated primary plant cell walls. The isolated, single-layered abaxial epidermis cell wall of an onion bulb was used as a test system since the cellulose microfibril packing in this cell wall is known to vary systematically from inside to outside scales and the most abundant matrix polymer, pectin, can easily be altered through simple chemical treatments such as ethylenediaminetetraacetic acid and calcium ions. Experimental results showed that the pectin network variation has significant impacts on the cell wall modulus, and not the cellulose microfibril packing.

Mn source effects on electrochemical properties of Fe -and Ni-substituted Li2MnO3 positive electrode material

This study examined Mn source effects on the electrochemical properties of Fe-substituted and Ni-substituted Li2MnO3 (Li1+x(Fe0.2Ni0.2Mn0.6)1−xO2, 0 < x < 1/3). Manganese sources of two kinds were selected: MnCl2·4H2O and KMnO4. Given the same preparation conditions, the chemical composition, transition metal distribution, and electrochemical properties of the two samples were compared. The sample obtained from KMnO4 exhibited better electrochemical performance, except for high-rate discharge characteristics, than that obtained from MnCl2. The origin of the different electrochemical performance was discussed to ascertain the unknown factor responsible for it. The full-cell performance was assessed using a single-layer laminate cell and mesocarbon microbead (MCMB) anode.

Ultra-Multilevel-Storage Phase Change Memory

In this study, we investigated ultra-multilevel-storage (UMLS) in lateral phase change memory (PCM) on the basis of device structure, reliability and programming method. We found that the number of resistance levels was limited strictly by the number of PC layers in multilayer multilevel cell (ML-MLC). A number of distinct levels up to 16 were obtained using a simple single-layer multilevel cell (SL-MLC). And material engineering is expected to greatly improve the reliability of MLS. We believe that fast-freely-achievable (FFA)-MLC by stair-like-pulse programming is a very promising method for futures application.

Delamination-resistant bi-layer electrolyte for anode-supported solid oxide fuel cells

One of the critical fuel cell degradation phenomena is ‘cell imbalance’ in a series-connected stack, which can cause abnormal operation under a negative cell voltage and consequently rapid degradation by anode interface delamination. In a previous study, the effect of electrolyte composition on the electrochemical degradation of solid oxide fuel cell (SOFC) was investigated, and it was observed that a small amount of ceria (an electronic conducting material) prevents anode delamination under abnormal (negative voltage) operation. However, the open circuit voltage (OCV) was lowered as a result of reduction of ceria. In the present study, bi-layer, YSZ (8mol % yttria doped zirconia, a predominantly ionic conductor) at the cathode side and 8CYSZ (8mol % ceria doped YSZ, a mixed ionic-electronic conductor) at the anode side were fabricated for anode-supported cells with a Pt probe embedded in each layer to estimate the internal oxygen chemical potential and tested under a negative voltage. The results indicated that the OCV was close to the theoretical value (similar to that of a YSZ single layer cell) and no delamination was observed under negative voltage operation (similar to the case of an 8CYSZ single-layer cell). Therefore, the bi-layer-structured electrolyte (with locally increased electronic conduction at the anode side) is effective in preventing anode/electrolyte delamination as well as maintaining open circuit voltage.

Photovoltaic Characterization and Electrochemical Impedance Spectroscopy Analysis of Dye-Sensitized Solar Cells Based on Composite TiO2–MWCNT Photoelectrodes

Dye-sensitized solar cells (DSSCs) use the effect of light on dye molecules to generate electricity through a photoelectrochemical mechanism. The aim of this study is to synthesize nanostructured DSSCs based on titania–multiwalled carbon nanotube (TiO2–MWCNT) composite photoelectrodes and improve their performance and efficiency. DSSCs were fabricated based on single-layer TiO2–MWCNT photoelectrodes with various weight percentages of multiwalled carbon nanotubes and bilayer TiO2/TiO2–2%MWCNT photoelectrodes. The microstructure and thickness of the anodic layers were characterized by field-emission scanning electron microscopy and optical microscopy. Also, to compare the conversion efficiency and determine the electron behavior in the electrical equivalent circuit of these cells, photovoltaic characterization and electrochemical impedance spectroscopy (EIS) analysis were used. The DSSC based on a single-layer TiO2–2%MWCNT electrode, compared with other single-layer DSSCs in this study, had the highest conversion efficiency of 3.9% (for anodic layer thickness of 9 μm). The efficiency of the solar cell with the bilayer TiO2/TiO2–2%MWCNT photoelectrode, in comparison with the single-layer solar cell with the TiO2–2%MWCNT electrode, showed a 23% increase from 4.33% to 5.35% (for anodic layer thickness of 18 μm). EIS analysis indicated that the charge-transport resistance of the DSSC based on the bilayer photoelectrode, in comparison with the single-layer TiO2 and TiO2–2%MWCNT solar cells, was decreased by 68% and 57%, respectively.

Microfluidics platform for measurement of volume changes in immobilized intestinal enteroids.

Intestinal enteroids are ex vivo primary cultured single-layer epithelial cell spheroids of average diameter ∼150 μm with luminal surface facing inward. Measurement of enteroid swelling in response to secretagogues has been applied to genetic testing in cystic fibrosis and evaluation of drug candidates for cystic fibrosis and secretory diarrheas. The current measurement method involves manual addition of drugs and solutions to enteroids embedded in a Matrigel matrix and estimation of volume changes from confocal images of fluorescently stained enteroids. We developed a microfluidics platform for efficient trapping and immobilization of enteroids for quantitative measurement of volume changes. Multiple enteroids are trapped in a "pinball machine-like" array of polydimethylsiloxane posts for measurement of volume changes in unlabeled enteroids by imaging of an extracellular, high-molecular weight fluorescent dye. Measurement accuracy was validated using slowly expanding air bubbles. The method was applied to measure swelling of mouse jejunal enteroids in response to an osmotic challenge and cholera toxin-induced chloride secretion. The microfluidics platform allows for parallel measurement of volume changes on multiple enteroids during continuous superfusion, without an immobilizing matrix, and for quantitative volume determination without chemical labeling or assumptions about enteroid shape changes during swelling.

Three-dimensional culture and identification of human eccrine sweat glands in matrigel basement membrane matrix

Interactions between the extracellular matrix (ECM) and epithelial cells are necessary for the proper organization and function of the epithelium. In the present study, we show that human eccrine sweat gland epithelial cells cultured in matrigel, a representation of ECM components, constitute a good model for studying three-dimensional reconstruction, wound repair and regeneration and differentiation of the human eccrine sweat gland. In matrigel, epithelial cells from the human eccrine sweat gland form tubular-like structures and then the tubular-like structures coil into sphere-like shapes that structurally resemble human eccrine sweat glands in vivo. One sphere-like shape can be linked to another sphere-like shape or to a cell monolayer via tubular-like structures. Hematoxylin and eosin staining has revealed that the tubular-like structures have a single layer or stratified epithelial cells located peripherally and a lumen at the center, similar to the secretory part or duct part, respectively, of the eccrine sweat gland in sections of skin tissue. Immunohistochemical analysis of the cultures has demonstrated that the cells express CK7, CK19, epithelial membrane antigen and actin. Thus, matrigel promotes the organization and differentiation of epithelial cells from the human eccrine sweat gland into eccrine sweat gland tissues.

Improved performance of ceria-based solid oxide fuel cell using doped LaGaO3 films deposited by pulsed laser deposition

A dense La0.9Sr0.1Ga0.8Mg0.2O3−δ (LSGM) film is fabricated using the pulsed laser deposition (PLD) technique on a Ce0.8Sm0.2O2−δ (SDC) electrolyte which is prepared using a co-pressing process on a NiO–SDC anode substrate. The LSGM/SDC bilayer electrolyte cell with Sm0.5Sr0.5CoO3−δ–Ce0.8Sm0.2O2−δ (SSC–SDC, 70:30 wt.%) cathode achieves significantly enhanced cell performance, yielding open circuit voltage (OCV) value of 0.89 V and maximum power density of 758 mW cm−2 at 700 °C. The electrical current leakage in the SDC single layer cell caused by the reduction of Ce4+ to Ce3+ in reducing environment has been eliminated by depositing the LSGM thin film as a blocking layer; besides, the reaction between NiO and LSGM can be prevented due to the dense SDC electrolyte layer. The influence of oxygen pressure and post-annealing temperature on the crystallinity, microstructure and surface roughness of the LSGM films are studied for obtaining a high quality film. Characterization analysis of the cell shows that the bilayer electrolyte deposited by the PLD technique have retained the chemical, mechanical and structural integrity of the cell.