Common fixed point theorems for the stronger Meir-Keeler cone-type function in cone ball-metric spaces

In this work, we introduce the concept of cone ball-metric spaces and we prove fixed point results on such spaces for mappings satisfying a contraction involving a stronger Meir-Keeler cone-type function.     

Field emission characteristics of carbon nanotubes post-treated with high-density Ar plasma

The field emission characteristics of carbon nanotubes (CNTs) grown by thermal chemical vapor deposition (CVD) and subsequently surface treated by high-density Ar plasma in an inductively coupled plasma reactive ion etching (ICP-RIE) with the various plasma powers were measured. Results indicate that, after treated by Ar plasma with power between 250 and 500 W, the emission current density of the CNTs is enhanced by nearly two orders of magnitude (increased from 0.65 to 48 mA/cm²) as compared to that of the as-grown ones. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to investigate the structural features relevant to the modified field emission properties of CNTs. The SEM images of CNTs subjected to a 500 W Ar plasma treatment exhibit obvious damages to the CNTs. Nevertheless, the turn-on fields decreased from 3.6 to 2.2 V/μm, indicating a remarkable field emission enhancement. Our results further suggest that the primary effect of Ar plasma treatment might be to modify the geometrical structures of the local emission region in CNTs. In any case, the Ar plasma treatment appears to be an efficient method to enhance the site density for electron emission and, hence markedly improving the electric characteristics of the CNTs.     

Triterpene Acids from the Leaves of Planchonella Duclitan (Blanco) Bakhuizan

From the methanolic extract of the leaves of Planchonella duclitan, 2α,3α,19α,23‐tetrahydroxy‐13,27‐cyclours‐11‐en‐28‐oic acid (1), myrianthic acid (2), 2‐hydroxyursolic acid (3), ursolic acid (4), pomolic acid (5), rotundic acid (6), and jacoumaric acid (7) were isolated, and their structures were elucidated on the basis of their spectroscopic analysis. Among them, compound 1 was a new cyclopropyl ursane‐type triterpene acid. Additionally, compounds 4 and 7 showed significant cytotoxicity toward human colorectal carcinoma cell line HT29 and human breast carcinoma cell line MCF‐7 with IC₅₀ values ranging from 5.8 ± 1.4 to 6.5 ± 1.9 μM.     

Optical Non‐Linearity from Montmorillonite Intercalated with a Chromophore‐Containing Dendritic Structure: A Self‐Assembly Approach

Chromophore‐containing dendritic structures (G1, G2) are utilized to intercalate layered silicates, which results in a large d‐spacing up to 126 Å. An exfoliated morphology is obtained by mixing the dendritic structure intercalated layered silicates with polyimide in N,N‐dimethylacetamide solution. The dendritic structures attached on the clay template would arrange in a non‐centrosymmetric manner. This self‐assembled arrangement brought about the electro‐optical coefficients of 5–6 pm · V⁻¹ for these relatively low chromophore‐containing organic/inorganic nanocomposites without resorting to poling. Excellent temporal stability (100 °C) is also achieved.

     

Kinetics of the reactions of NCO with NO and NO2

The rate coefficients of the reactions of NCO radicals with NO and NO₂: (1) NCO + NO → products (293–836 K) and : (2) NCO + NO₂ → products (294–774 K) were measured by means of laser photolysis and laser induced fluorescence technique in the indicated temperature ranges. NCO radicals were produced from the reaction of CN, from photodissociation of ICN or BrCN, with O₂. The concentration of NCO was monitored with a dye laser set at 414.95 nm. We determined k₁ = 1.73 × 10^?5 T^?2.01 exp(?470/T) cm³ molecule^?1 s^?1 that agrees with published results at room temperature and confirms the temperature dependence of an early report. A non-Arrhenius negative temperature dependence of k₂ was observed in this work that agrees satisfactorily with results for a shock tube¹⁸ near 1250 K. We obtained k₂ = 6.4 × 10^?10 T^?0.646 exp(164/T) cm³ molecule^?1 s^?1 for 1250 K ≥ T ≥ 294 K by combining data of these two measurements. Our result at 294 K and the temperature dependence disagree with results of two previous investigations. © 1995 John Wiley & Sons, Inc.     

Degenerate riccati equations with unbounded coefficients arising in transport theory

Of concern is the degenerate Riccati equation of the form TR+RT=TA+TBR+RTC+RTDR (?). This models a certain transport equation in the half-space. Our first result will concern a unique, positive solution of the operator equation SR+RT=K in a anach space equipped with a cone structure. We then proceed to prove existence of positive solutions for (?) on an L¹ space of σ-finite measure and a Banach space X, respectively, under different assumptions. Some estimates of the solution with respect to certain norms are obtained.     

Biochemical and biomedical applications of multifunctional magnetic nanoparticles: a review

Nanotechnology offers tremendous potential for future medical diagnosis and therapy. Various types of nanoparticles have been extensively studied for numerous biochemical and biomedical applications. Magnetic nanoparticles are well-established nanomaterials that offer controlled size, ability to be manipulated by an external magnetic field, and enhancement of contrast in magnetic resonance imaging. As a result, these nanoparticles could have many applications including bacterial detection, protein purification, enzyme immobilization, contamination decorporation, drug delivery, hyperthermia, etc. All these biochemical and biomedical applications require that these nanoparticles should satisfy some prerequisites including high magnetization, good stability, biocompatibility, and biodegradability. Because of the potential benefits of multimodal functionality in biomedical applications, in this account highlights some general strategies to generate magnetic nanoparticle-based multifunctional nanostructures. After these magnetic nanoparticles are conjugated with proper ligands (e.g., nitrilotriacetate), polymers (e.g., polyacrylic acid, chitosan, temperature- and pH-sensitive polymers), antibodies, enzymes, and inorganic metals (e.g., gold), such biofunctional magnetic nanoparticles exhibit many advantages in biomedical applications. In addition, the multifunctional magnetic nanoparticles have been widely applied in biochemical fields including enzyme immobilization and protein purification.     

Liquid-phase adsorption and desorption of phenol onto activated carbons with ultrasound

The effect of 48-kHz ultrasound on the adsorption and desorption of phenol from aqueous solutions onto coconut shell-based granular activated carbons was studied at 25 degrees C. Experiments were performed at different carbon particle sizes (1.15, 2.5, 4.0 mm), initial phenol concentrations (1.06-10.6 mol/m3), and ultrasonic powers (46-133 W). Regardless of the absence and presence of ultrasound, the adsorption isotherms were well obeyed by the Langmuir equation. When ultrasound was applied in the whole adsorption process, the adsorption capacity decreased but the Langmuir constant increased with increasing ultrasonic power. According to the analysis of kinetic data by the Elovich equation, it was shown that the initial rate of adsorption was enhanced after sonication and the number of sites available for adsorption was reduced. The effect of ultrasonic intensity on the initial rate and final amount of desorption of phenol from the loaded carbons using 0.1 mol/dm3 of NaOH were also evaluated and compared.     

Synthesis and evaluation of in vitro bioactivity for polysubstituted N-arylpyrazole derivatives

New polysubstituted N-arylpyrazole derivatives were synthesized from N1-arylsydnone with acetylene and boronic acid, including 2-thiophenyl, 3-thiophenyl, 2-benzo[b]thiophenyl, or dibenzothiophenyl-4-boronic acid, via 1,3-dipolar cycloaddition and Suzuki coupling reaction. Based on the growth inhibitory activity results against lung carcinoma (NCI-H226), nasopharyngeal (NPC-TW01), and T-cell leukemia (Jurkat) cancer cells, compounds 5d and 7d with dibenzothiophenyl bioisostere possessed the significant inhibitory activity for NPC-TW01 (32 μM and 16 μM) and NCI-H226 (16 μM and 8.9 μM), respectively.     

Abstract Riccati equations in an L1 space of finite measure and applications to transport theory

We consider operator-valued Riccati initial-value problems of the form R′(t) + TR(t) + R(t)T = TA(t) + TB(t)R(t) + R(t)TC(t) + R(t)TD(t)R(t), R(0) = R₀. Here A to D and R₀ have values as non-negative bounded linear operators in L¹ (μ), where μ is a finite measure, and T is a closed non-negative operator in L¹ (μ) satisfying additional technical conditions. For such problems the notion of strongly mild solutions is defined, and local existence and uniqueness theorems for such solutions are established. The results of the analysis are applied to the reflection kernels with both isotropically scattering homogeneous and anisotropically scattering inhomogeneous medium.