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Molecular dynamics (MD) simulations have been performed to determine the reinforcing role of two-dimensional (2D) nanosheets on Young's and shear moduli of nanosheet-strengthened polylactic acid (PLA). Various volume fractions of nanosheets in addition to different kinds of nanosheets, that is, graphene (GR), silicon carbide nanosheet (SiCNS), and boron-nitride nanosheet (BNNS), are regarded as affecting parameters on the mechanical response. Uniaxial tensile and shear tests are conducted and related stress–strain diagrams are achieved to be used for exploring mechanical properties. It is found that the incorporation of 2D nanosheets into PLA has a noticeable impact on the mechanical behavior of the polymer. In a desired percentage of volume fraction (${\rm v}_{\rm f}$ v f ), GR and SiCNS have performed the greatest and least roles in augmenting the mechanical properties of PLA nanocomposites, respectively. Compared to those, the reinforcing effect of the BNNS comes in between. Also, the results show that there is a growing trend in longitudinal and transverse Young's moduli (${\rm E}_{\rm x}$ E x and ${\rm E}_{\rm y}$ E y ) and the XY-plane shear modulus (${\rm G}_{{\rm xy}}$ G xy ) of nanocomposites as the ${\rm v}_{\rm f}$ v f of nanosheets increases. [ABSTRACT FROM AUTHOR]

Salsola is one of the largest genera in the tribe Salsoleae within Amaranthaceae, with many species that share morphological characteristics, which makes it a challenging genus to study. In this study, 11 quantitative and eight qualitative morphological traits were evaluated and measured. Ward's dendrogram showed two main clusters: one composed of S. brachiata and S. turcomanica , and the other composed of two subclusters, with populations of S. kali, S. incanescens, S. orientalis and S. dendroides. In addition, we performed molecular phylogenetic analyses conducted with sequence data from nrDNA (ITS and ETS) and cpDNA markers (psb B- psb H and atp B- rbc L) under maximum parsimony, Bayesian inference and maximum likelihood approaches. All the members were clustered into a well-supported clade (PP = 1, ML/BS = 0.89) composed of two subclades: subclade A included S. turcomanica and S. brachiata (PP = 0.90, ML/BS = 73) and subclade B (PP = 0.95, ML/BS = 81) comprised S. incanescens, S. orientalis, S. dendroides and S. kali. The current study provides novel insights at morphological and molecular levels, as well as the results of molecular studies based on nr- and cpDNA sequence data that are congruent with morphological analyses. [ABSTRACT FROM AUTHOR]

Shahla Assadi Hoveyzian,1 Abdolali Shariati,2 Shayeste Haghighi,2 Sayed Mahmud Latifi,2 Mohammad Ayoubi3 1Abadan Faculty of Medical Sciences, Academic Board, Nursing and Midwifery School, Abadan, Iran; 2Ahvaz Jundishapur of Medical Sciences, Ahvaz, Iran; 3Cellular and Molecular Biology Branch, Science School, Tehran University, Tehran, IranCorrespondence: Shahla Assadi HoveyzianAcademic Board, Nursing and Midwifery School, Abadan Faculty of Medical Sciences, Abadan, IranTel + 98 916-304-6425Email Assadi.shahla@yahoo.comPurpose: Currently, revisions in education and evaluation in the nursing domain are necessary to increase the clinical competence of graduates. The aim of this study was to compare nursing students’ clinical competence using the portfolio method with conventional education and evaluation methods in clinical education.Methods: In this pretest–posttest quasiexperimental crossover study, all six-semester undergraduate nursing students of Ahvaz Jundishapur University of Medical Sciences were classified into four groups. They were selected based on the use of portfolio and conventional methods during their apprenticeship. Then, they were educated using conventional and portfolio methods. Their clinical competence was measured by a self-appraisal questionnaire. Data were statistically analyzed with independent and paired t-tests.Results: There were significant differences between average scores of clinical competence in all three domains before and after study in portfolio-based education method (P=0.0001). Furthermore, the average difference in scores before and after internship between the two educational groups in all three domains — cognitive (P=0.002), affective (P=0.0001), and psychomotor — (P=0001) was significant. Similarly, there was a significant difference in total average scores of clinical competence between the two methods (P=0.0001).Conclusion: The results showed the effect of educational method on increasing the clinical competence of nursing students in a clinical unit. This new method can be used as a combination of education, evaluation and student-centered methods.Keywords: clinical competence, education, nursing student, portfolio

A two-stage molecular dynamics (MD)-finite element (FE) modeling method is developed based on the concepts of representative volume element (RVE) and equivalent solid fibers (ESFs) containing functionalized carbon nanotubes (ESFs-fCNTs). First, the influences of nanotubes' chirality, different percent of functionalization ( P func ), various functional atoms, and polymers on the tensile and shear properties of the fCNTs inserted into the polymer matrix (fCNTs/polymer) are discovered using MD simulations. Then, using MD information as input data, the effective Young's modulus of polymeric unit cell strengthened by ESFs-fCNTs (ESFs-fCNTs/polymer) is explored through FE modeling. The ratio of effective Young's modulus of the unit cell ( E UC ) to Young's modulus of the polymeric cube ( E P ) is reported and all findings ( E UC E P ) are compared to the ESFs-pure CNTs/polymer results as well. It is found that longitudinal Young's modulus ( E x ) of nanofillers/polymer RVEs affects remarkably the E UC E P of the ESFs-nanofillers/polymer nanocomposites. The E x decreases by increasing the P func. Generally, the reinforcing impact of zigzag nanotubes compared to armchair ones on the E x of polymer RVEs is more considerable. Additionally, FE-based results illustrate that as the volume fraction of ESFs ( v f ESF ) increases, the E UC E P is enhanced. At a specific P func , the reinforcing effect of the ESFs-armchair and zigzag fCNTs is more in favor of polyethylene nanocomposites than that of the polypropylene systems. [ABSTRACT FROM AUTHOR]