Electro-copolymerisation of indene and styrene

Electroinitiated cationic copolymerisation of indene and styrene was investigated by constant potential electrolysis. Effects of copolymerisation potential and temperature on the copolymer composition and the reactivity ratios are discussed. The reactivity ratios of the monomers were calculated according to the integrated Lewis-Mayo equation.     

Calcitonin treatment in reflex sympathetic dystrophy: a preliminary study

Reflex sympathetic dystrophy is one of the important complications effecting the rehabilitation programmes of hemiplegic patients in a negative manner by causing pain and function loss. In this study, the aim was to investigate the effects of salmon calcitonin treatment in reflex sympathetic dystrophy that develops in hemiplegia. Forty-one patients with hemiplegia resulting from cerebrovascular events and stage 1-2 reflex sympathetic dystrophy were included in the study. Salmon calcitonin, 1 x 100 IU/day intramuscularly for 4 weeks, was administered to 25 of these patients (calcitonin group) to the other 16 patients physiological saline, 1 ml/day intramuscularly for 4 weeks, was administered (control group). At the end of the fourth week of treatment the pain score of the calcitonin group was significantly lower than that of the control group. Shoulder abduction and external rotation, wrist flexion and metacarpophalangeal extension of the calcitonin group were found to be significantly better than those of the control group. In the calcitonin group the significant decrease in pain and tenderness resulted in improvement of range of motion and motor functions.     

Visualizing Extracellular Vesicles and Their Function in 3D Tumor Microenvironment Models

Extracellular vesicles (EVs) are cell-derived nanostructures that mediate intercellular communication by delivering complex signals in normal tissues and cancer. The cellular coordination required for tumor development and maintenance is mediated, in part, through EV transport of molecular cargo to resident and distant cells. Most studies on EV-mediated signaling have been performed in two-dimensional (2D) monolayer cell cultures, largely because of their simplicity and high-throughput screening capacity. Three-dimensional (3D) cell cultures can be used to study cell-to-cell and cell-to-matrix interactions, enabling the study of EV-mediated cellular communication. 3D cultures may best model the role of EVs in formation of the tumor microenvironment (TME) and cancer cell-stromal interactions that sustain tumor growth. In this review, we discuss EV biology in 3D culture correlates of the TME. This includes EV communication between cell types of the TME, differences in EV biogenesis and signaling associated with differing scaffold choices and in scaffold-free 3D cultures and cultivation of the premetastatic niche. An understanding of EV biogenesis and signaling within a 3D TME will improve culture correlates of oncogenesis, enable molecular control of the TME and aid development of drug delivery tools based on EV-mediated signaling.     

Lower bounds on lengths of checking sequences

Lower bounds on the lengths of checking sequences constructed for testing from Finite State Machine-based specifications are established. These bounds consider the case where a distinguishing sequence is used in forming state recognition and transition verification subsequences and identify the effects of overlapping among such subsequences. Empirical results show that the existing methods for construction of checking sequences provide checking sequences with lengths that are within acceptable distance to these lower bounds.     

Loss mechanisms and high power piezoelectrics

Heat generation is one of the significant problems in piezoelectrics for high power density applications. In this paper, we review the loss mechanisms in piezoelectrics first, followed by the heat generation processes for various drive conditions. Heat generation at off-resonance is caused mainly by dielectric loss tan δ′ (i.e., P-E hysteresis loss), not by mechanical loss, while the heat generation at resonance is mainly attributed to mechanical loss tan φ′. Then, practical high power materials developed at Penn State is introduced, which exhibit the vibration velocity more than 1 m/s, leading to the power density capability 10 times of the commercially available “hard” PZTs. We propose a internal bias field model to explain the low loss and high power origin of these materials. Finally, using a low temperature sinterable “hard” PZT, we demonstrated a high power multilayer piezoelectric transformers.     

Standardization problem of author affiliations in citation indexes

Academic effectiveness of universities is measured with the number of publications and citations. However, accessing all the publications of a university reveals a challenge related to the mistakes and standardization problems in citation indexes. The main aim of this study is to seek a solution for the unstandardized addresses and publication loss of universities with regard to this problem. To achieve this, all Turkey-addressed publications published between 1928 and 2009 were analyzed and evaluated deeply. The results show that the main mistakes are based on character or spelling, indexing and translation errors. Mentioned errors effect international visibility of universities negatively, make bibliometric studies based on affiliations unreliable and reveal incorrect university rankings. To inhibit these negative effects, an algorithm was created with finite state technique by using Nooj Transducer. Frequently used 47 different affiliation variations for Hacettepe University apart from “Hacettepe Univ” and “Univ Hacettepe” were determined by the help of finite state grammar graphs. In conclusion, this study presents some reasons of the inconsistencies for university rankings. It is suggested that, mistakes and standardization issues should be considered by librarians, authors, editors, policy makers and managers to be able to solve these problems.     

Do ozone and boric acid affect microleakage in class V composite restorations?

The aim of this in vitro study was to evaluate the effects of chlorhexidine gluconate (2%), sodium hypochloride (2.5%), ozone gas, and boric acid at different concentrations (1%, 3%, 5%, and 7%) on microleakage from composite restorations.

In a total of 80 extracted human canine teeth, a class V cavity was opened on the buccal surface and the samples were separated into eight groups. In the control group, no procedure was applied for cavity disinfection, then composite restoration (Z250, 3M) was made using single-stage, self-etch adhesive (Single Bond 3M). In the other groups, seven different disinfectants were used, then the cavity was restored. The teeth were split into two in the buccolingual direction, parallel to the long axes. Stain penetration was examined under stereomicroscope and scored. Examination with SEM was made on one sample from each group, selected at random. Statistical evaluations were made using Dunnett C Post Hoc Comparison and Kruskal–Wallis H tests.

In the occlusal region evaluation, the groups with the lowest level of leakage were the 3% and 5% boric acid groups, and the highest levels of microleakage were determined in the chlorhexidine group and the 1% boric acid group. In the gingival region, the lowest level of microleakage was in the 5% boric acid group and the highest levels were determined in the 1% and 7% boric acid groups.

Boric acid disinfectants used at suitable concentrations were not seen to create a risk in respect of microleakage.     

Swelling kinetics,mechanical properties,and release characteristics of chitosan‐based semi‐IPN hydrogels

Two series of pH‐sensitive semi‐interpenetrating network hydrogels (semi‐IPN) based on chitosan (CS) natural polymer and acrylamide (AAm) and/or N‐hydroxymethyl acrylamide (HMA) monomers by varying the monomer and CS ratios were synthesized by free radical chain polymerization. 5‐Fluorouracil (5‐FU), a model anticancer drug, has been added to the feed composition before the polymerization. The characterization of gels indicated that the drug is molecularly dispersed in the polymer matrix. The swelling kinetics of drug‐loaded gels have decreased with increased HMA content at 37°C in both distilled water and buffer solutions with a pH of 2.1 or 7.4. Elastic modulus of the gels increased with the increase in HMA content and higher CS concentration enhanced the elastic modulus positively. Moreover, cumulative release percentages of the gels for 5‐FU were ca. 10% higher in pH 2.1 than those in pH 7.4 media. It was determined that they can be suitable for the use in both gastric and colon environments. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41886.     

Controlling the particle size of nanobrookite TiO2 thin films

In this study, pure nanobrookite TiO₂ thin films were successfully deposited on glass substrates with the spin-coating method using titanium butoxide and acetic acid. The particle size of TiO₂ films was controlled by the water:AcAc volume ratio. This study shows that it is possible to obtain single oriented pure brookite films. The structural and optical properties of the nanobrookite TiO₂ thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM), spectrophotometer (NKD), and Fourier transform infrared spectrometer (FTIR).