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The ternary superparamagnetic nanocomposites consisting of graphene oxide (GO), Fe3O4 nanoparticles, and optically active poly(amide-imide) (PAI) were fabricated in three steps consisting of a facile one-pot in situ growth of Fe3O4 on GO, resulted in the preparation of the magnetic Fe3O4@GO, modification of Fe3O4@GO by 3-aminopropyltriethoxy silane to introduce amino groups on its surface, and subsequently its compositing by various levels of 5, 10, and 15 wt% with chiral PAI derived from 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide and N, N′-(4,4′-carbonyldiphthaloyl)-bis-l-phenylalanine diacid through ultrasonic irradiation. Characterization of the resulting nanocomposites was performed by Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The SEM analysis showed Fe3O4 nanoparticles with 30 nm size successfully decorated the GO nanosheets. The TGA analysis established the expected thermal stabilities for PAI/Fe3O4@GO nanocomposites. Furthermore, incorporation of Fe3O4@GO in polymer matrix improved the mechanical properties substantially. PAI/Fe3O4@GO 10 wt% was used to evaluate the sorption properties of Hg2+ at pH 7.

A new diamine monomer containing indole unit, 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide, was successfully synthesized and applied in the preparation of a series of polyimides (PIs) via a conventional two-step polymerization procedure with three aromatic tetracarboxylic dianhydrides. The prepared polymers showed excellent solubility in organic solvents such as N-methyl-2-pyrrolidinone (NMP), N, N-dimethylacetamide, and N, N-dimethylformamide. Flexible and strong films of PIs were obtained via casting from their solutions. The glass transition temperature of these polymers was in the range of 223–264°C. They were fairly stable up to a temperature around 300°C and lost 10% weight at 372°C in nitrogen atmosphere. All of the polymers revealed absorption maxima around 323 nm with a fluorescence emission maxima around 378–406 nm in NMP. The cyclic voltammetry of the PIs exhibited an oxidation wave with a peak at 1.07 V. The resulting polymer films had tensile strengths from 83 MPa to 107 MPa, elongates at break of 7–10%, and tensile moduli of 2.2–2.3 GPa.

Thermally stable polyimide/titania (PI/TiO 2 ) hybrid nanocomposite films have been successfully synthesized through the in situ formation of TiO 2 within a PI matrix via sol-gel process. Poly(amic acid) (PAA) solution is prepared from 3,5-diamino benzoyl amino phenyl-14Hdibenzo[a,j]xanthene and 4,4 0 -(hexaflouroisopropylidene)diphthalic anhydride in N-methyl-2-pyrrolidinone solvent. The different amounts of tetraethyl orthotitanate and actylacetone are incorporated into PAA matrix, and then thermally imidized to form PI/TiO 2 . The chelating agent, acetylacetone, was applied to reduce the gelation rate of titanium alkoxide. Thermal decomposition temperatures of nanocomposites with a 10% weight loss were in excess of 500 C, and char yields higher than 63% at 800 C in nitrogen. The chemical and morphological structures of the hybrid nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. The results show that the TiO 2 particles are well dispersed in the PI matrix with particle size between 10 and 30 nm in diameter. POLYM. COMPOS.,

BACKGROUND: The ultimate goal in educating medical students is to train skilled workforce who by obtaining the required knowledge of the discipline, personal and professional skills, and attitudes to enter the national health-care system. This study was conducted with the goal of designing a comprehensive clinical competency test of operating room technology student using the Delphi technique, and then, the clinical skills of the operating room technology students of the paramedical school were assessed using the CIPP evaluation model. MATERIALS AND METHODS: The present study was conducted in the University of Medical Sciences to evaluate clinical skills with Delphi technique and CIPP evaluation model. This was a mixed methods study. Purposive sampling method was employed in the qualitative stage, and a census was conducted in the quantitative part. A comprehensive clinical competency test was designed in this research using the Delphi technique and was conducted with 18 students. Then, clinical skills evaluation was performed by descriptive-analytical statistical tests and evaluator's observation using the CIPP model. RESULTS: The comprehensive clinical competencies test of the surgical technology students was designed in four sections: content, evaluation method, test conditions, and the criteria for passing the comprehensive test. The results in the implementation stage showed that the operating room technology students had a range of excellent to weak performances in exhibiting basic skills at different levels. CONCLUSIONS: The results of the present study showed that the comprehensive test, designed based on the Delphi technique of experts, and using the CIPP model can be a good criterion for the evaluation of the operating room technology students before entering the clerkship.