Impedance,Electrical Equivalent Circuit (EEC) Modeling,Structural (FTIR and XRD), Dielectric,and Electric Modulus Study of MC-Based Ion-Conducting Solid Polymer Electrolytes

The polymer electrolyte system of methylcellulose (MC) doped with various sodium bromide (NaBr) salt concentrations is prepared in this study using the solution cast technique. FTIR and XRD were used to identify the structural changes in solid films. Sharp crystalline peaks appeared at the XRD pattern at 40 and 50 wt.% of NaBr salt. The electrical impedance spectroscopy (EIS) study illustrates that the loading of NaBr increases the electrolyte conductivity at room temperature. The DC conductivity of 6.71 × 10⁻⁶ S/cm is obtained for the highest conducting electrolyte. The EIS data are fitted with the electrical equivalent circuit (EEC) to determine the impedance parameters of each film. The EEC modeling helps determine the circuit elements, which is decisive from the engineering perspective. The DC conductivity tendency is further established by dielectric analysis. The EIS spectra analysis shows a decrease in bulk resistance, demonstrating free ion carriers and conductivity boost. The dielectric property and relaxation time confirmed the non-Debye behavior of the electrolyte system. An incomplete semicircle further confirms this behavior model in the Argand plot. The distribution of relaxation times is related to the presence of conducting ions in an amorphous structure. Dielectric properties are improved with the addition of NaBr salt. A high value of a dielectric constant is seen at the low frequency region.     

A Study of Methylcellulose Based Polymer Electrolyte Impregnated with Potassium Ion Conducting Carrier: Impedance,EEC Modeling,FTIR, Dielectric,and Device Characteristics

In this research, a biopolymer-based electrolyte system involving methylcellulose (MC) as a host polymeric material and potassium iodide (KI) salt as the ionic source was prepared by solution cast technique. The electrolyte with the highest conductivity was used for device application of electrochemical double-layer capacitor (EDLC) with high specific capacitance. The electrical, structural, and electrochemical characteristics of the electrolyte systems were investigated using various techniques. According to electrochemical impedance spectroscopy (EIS), the bulk resistance (R_b) decreased from 3.3 × 10⁵ to 8 × 10² Ω with the increase of salt concentration from 10 wt % to 40 wt % and the ionic conductivity was found to be 1.93 ×10⁻⁵ S/cm. The dielectric analysis further verified the conductivity trends. Low-frequency regions showed high dielectric constant, ε′ and loss, ε″ values. The polymer-salt complexation between (MC) and (KI) was shown through a Fourier transformed infrared spectroscopy (FTIR) studies. The analysis of transference number measurement (TNM) supported ions were predominantly responsible for the transport process in the MC-KI electrolyte. The highest conducting sample was observed to be electrochemically constant as the potential was swept linearly up to 1.8 V using linear sweep voltammetry (LSV). The cyclic voltammetry (CV) profile reveals the absence of a redox peak, indicating the presence of a charge double-layer between the surface of activated carbon electrodes and electrolytes. The maximum specific capacitance, C_s value was obtained as 118.4 F/g at the sweep rate of 10 mV/s.     

Components and distributions of cytoskeleton network in neoplastic Hep G2cells extracted with triton X-100 and (NH4)2SO4

AIM To explore the components and the distributions of the cytoskeleton network in neoplastic Hep G2 cellsextracted with triton X-100 and (NH4)2SO4.METHODS Using the mouse lung adenocarcinoma cell sublines (C6/C7) with low and high metastasis as acontrol, the human hepatocellular carcinoma cell line (Hep G2) as well as the cell sublines (C6/C7) wasextracted with triton X-100 and/or (NH4)2SO4, then stained with Coomasie blue R250 or labeled withimmunoenzymatic technique to identify the cytokeratin-type or vimentin-type intermediate filamentcomponents and study the distributions of cytoskeleton comparatively.RESULTS Extracted with triton X-100 and/or (NH4)2SO4, then stained with Coomasie blue R250, the cells'cytoskeleton network were showed clearly; still it was very difficult to identify the variations of thecytoskeleton network in morphology by light microscopy when the same cells was extracted with the differentextraction above; compared with the low metastasis cells (C7), most of the high metastasis cells (C6) werelikely showed that the distribution of the cytoskeleton network was more irregular and uneven as well asgathering on one side to the cell neucleus, and so did a few of Hep G2 cells (the percentage of regular andeven distribution of cytoskeleton, C6: 8.0±1.0; C7: 84.0±2.0; Hep G2: 96.0±2.0; n = 500; x2-test,P<0.01). Moreover, extracted with triton X-100 and (NH4)2SO4, then labeled by immunoenzymatictechnique, the mouse lung adenocarcinoma sublines (C6/C7) were positive for cytokeratin antibody only, butthe hepatocellular carcinoma cell (Hep G2) was positive for both cytokeratin and vimentin antibodies.Besides these, in the same cells, the distribution of the intermediate filament network showed by theimmunoenzymatic technique was nearly keeping with that of the cytoskeleton network showed by Coomasieblue R250 stain.CONCLUSION ① It is very difficult to identify the variations of the cytoskeleton network in morphologyby light microscopy when the same cell was extracted with triton X-100 and/or (NH4)2SO4 then stained withCoomasie blue R250 in comparsion. ② The characterizing distribution of the intermediate filament as well asthe ctoskeleton network that was irregular, uneven and gathering on one side to the nucleus in neoplastic cellmight provide a valuable information for studing tumor metastasis. ③ In analysing the components ofintermediate filament protein of malignant tumor cells, the heterogenous proteins (co-expression) must betaken into consideration.     

The Effect of Ca Dopant on the Electrical and Dielectric Properties of BaTi4O9 Sintered Ceramics

The current research examines the impact of Ca²⁺ substitution on the phase and electrical properties of (Ba_1−xCa_x)Ti₄O₉, (x = 0.0, 0.3, 0.6, and 0.9) sintered pellets synthesized by solid-state reaction method. The as-synthesized samples were analyzed using X-ray diffraction (XRD) and impedance spectroscopy. The emergence of orthorhombic phase fit into space group Pnmm was revealed by XRD, and the addition of Ca resulted in a considerable shift in grain size. Dielectric properties were determined using an impedance spectroscopy in a wide frequency range from 1MHz to 3 GHz. The dielectric properties i.e., dielectric constant (ε_r) and dielectric loss (tanσ), were measured at 3 GHz frequency. The frequency-dependent parameters such as conductivity, dielectric constant, and dielectric loss indicated that the relaxation process is a Maxwell–Wagner type of interfacial polarization. The improved dielectric properties and low energy loss have made (Ba_1−xCa_x)Ti₄O₉ a prominent energy storage material. This study provides the possibility to improve its dielectric properties and reduce energy loss, making it an excellent energy storage material.     

Phase I Trial of FLAGM with High Doses of Cytosine Arabinoside for Relapsed, Refractory Acute Myeloid Leukemia: Study of the Japan Adult Leukemia Study Group (JALSG)

This study was designed to determine the optimal high dose for cytosine arabinoside (ara-C) in combination with fludarabine, granulocyte colony-stimulating factor, and mitoxantrone (FLAGM) in adult patients with relapsed or refractory acute myeloid leukemia. Nine patients were enrolled at increasing dosage levels of ara-C (8, 12, and 16 g/m2 per dose level). Ara-C and fludarabine were administered once a day at level 1, once or twice a day at level 2, and twice a day at level 3. All patients had grade 4 hematologic toxicity. The most common adverse events were of grade 2 or less, with nausea and vomiting being the most common (6 events), followed by diarrhea (5 events), and rash (5 events). Of the 13 grade 3 nonhematologic toxicities reported, the 2 most common were febrile neutropenia (6 events) and disseminated intravascular coagulation (3 events). No early deaths were observed. FLAGM with high-dose ara-C was considered safe for patients, and the recommended dosage of ara-C in this study was 2 g/m2 every 12 hours for a total dose of 16 g/m2.     

Evidence for a limited role of NAD(P)H in the nutritional regulation of glucagon release: Studies with menadione and NH4Cl

Summary Menadione and NH₄Cl were reported to lower the islet content of reduced pyridine nucleotides. They were used to investigate the possible significance of NAD(P)H in the regulation of glucagon release by glucose and arginine. Menadione (10–25 μmol/l) enhanced arginine-stimulated glucagon release at a low glucose concentration (3.3 mmol/l), but failed both to affect glucagon secretion in the sole presence of glucose (3.3 mmol/l) and to suppress the inhibitory action of glucose 11.1 mmol/l upon glucagon output. In contrast to menadione, NH₄Cl inhibited arginine-stimulated glucagon release at the low glucose concentration. The inhibitory action of glucose in high concentration upon glucagon release was not suppressed by NH₄Cl. These findings do not permit to extrapolate to the A₂-cell the concept that reduced pyridine nucleotides represent a major coupling factor in the nutritional regulation of hormonal release.     

Methylation of the p15(INK4B) gene in myelodysplastic syndrome: it can be detected early at diagnosis or during disease progression and is highly associated with leukaemic transformation

To investigate the time sequence of occurrence of p15(INK4B) gene methylation in myelodysplastic syndrome (MDS) and its correlation with leukaemic transformation and survival of patients, the methylation status of the p15(INK4B) promoter region was analysed in 50 patients and was serially studied in 22 of them. Of the 50 patients, 17 (34%) showed p15(INK4B) gene methylation, first demonstrated at diagnosis or during follow-up. When FAB subtypes at the time of study were used in the analysis, the incidence of (p15INK4B) methylation in each risk group of MDS remained stable throughout the course: 0% for low-risk MDS [refractory anaemia (RA) and RA with ring sideroblasts] and from 23% at diagnosis to 30% for high-risk MDS [RA with excess of blasts (RAEB), RAEB in transformation and chronic myelomonocytic leukaemia] respectively. The incidence of p15(INK4B) methylation rose to 60% at initial study and, finally, to 75% in cases of acute myeloid leukaemia (AML) evolved from MDS. Most patients (69%) with p15(INK4B) methylation showed disease progression to AML; it could be detected before, at the time or after the diagnosis of leukaemic transformation. p15(INK4B) methylation in MDS patients implicated a shorter survival time in univariate analyses, but its prognostic significance disappeared in multivariate analyses. In conclusion, p15(INK4B) methylation can be detected early at the diagnosis of MDS or acquired during disease progression. It may play an important role in the pathogenesis of some high-risk MDS and is related to leukaemic transformation of MDS.