Optical properties of Li-patterned graphene via a self-assembling molecular network

Adsorbed Li atoms on graphene can tune its electronic properties in favor of various applications. The tendency of Li atoms for clustering on a graphene surface remains challenging. Herein, adsorption of Li atoms on graphene through a self-assembling network is investigated and its stability is verified via molecular dynamic calculations. Among the various properties that Li-doped graphene can possess, we explore its optical properties by calculating its electron energy loss spectra (EELS). We demonstrate that the variation in the distribution of Li atoms on graphene results in different peaks in the EELS curves.

Electrostatic patterning on graphene with dipolar self-assembly

We have investigated the influence of electric dipole moment in different periodic two-dimensional network on the electronic structure properties of graphene. Although the control of doping level in graphene within a van der Waals heterostructure constitutes a difficult task, the dipolar nature of the different molecular stacks can be used to control its electrostatic properties. First, we demonstrate that the orientation and magnitude of the adsorbed molecular dipole moments allow to control the electrical behaviour of graphene, and acts as an electrostatic gate that shifts neutrality point of graphene to behave as n- or p-doped materials. Then, we show that the presence of local dipole moment in SAN induces an electrostatic potential in graphene that creates well-defined patterned regions with different electronic characteristics that would influence the confinement of molecular species.

First Report of Passerilepis parina (Cestoda: Hymenolepididae) from Parus major in Iran: A Probable Fatal Case Due to Hyperin-fection

Cestodes are important parasites that can affect the health of humans and wildlife. Among these, the genus Passerilepis is an important endoparasite of Passeriform birds while poorly studied in Iran. During a parasitological field survey in central parts of Iran in 2018, thirty-two cestodes, as an obstructive intertwined mass, recovered from the intestine of a recently dead Parus major (great tit). Morphological characteristics of recovered cestodes were drawn carefully by a camera lucida equipped microscope and identification was carried out using standard keys. All of the collected cestodes were identified as P. parina. In the current study, we recorded P. parina from great tit for the first time in Iran.

First report of Spirocerca lupi larva in dung beetles (Scarabaeus armeniacus) in the central region of Iran: A morphological and molecular identification

Dung beetles as detritivores insects, naturally use feces of vertebrates as foods and reproduction beds. This leads to frequent contacts between dung beetles and parasitic helminths. The current study was carried out to assess infections of dung beetles with larval stages of helminths in rural areas of Taleqan County, Alborz Province, Iran. A total number of 200 dung beetles were collected randomly in June 2017 from the highlands of Taleqan County. Beetles were dissected in normal saline and carefully studied using a stereomicroscope. Morphological characteristics of the recovered larvae were drawn using a camera lucida equipped microscope at 400× magnification. Then, genomic DNAs of the recovered larvae extracted and PCR amplifications of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were carried out and the amplicons were sequenced. All collected dung beetles identified as Scarabaeus armeniacus from the Scarabaeidae family (55.5 % were male and 44.5 % female). Three females of the beetles have been found to be naturally infected with the third stage larvae of Spirocerca lupi. The average length and width of the larvae were 2.95 (2.81-3.15; CI 95 %) and 0.12 (0.1-0.15; CI 95 %) mm, respectively. The phylogenetic analysis showed that S. lupi belonged to a clade within the Spirocercidae family. In the current study, S. armeniacus introduced as a potential biological vector for transmission of S. lupi to vertebrates in the region. To the best of the authors' knowledge, this is the first report on the larval stages of S. lupi in S. armeniacus.

Intestinal helminthic parasites of rodents in the central region of Iran: first report of a capillariid nematode from Dryomys nitedula

OBJECTIVES

Rodents play an important role to spread zoonotic diseases through society. The current study was carried out to collect informative data on the intestinal helminthic infections of wild rodents in Taleqan County, Alborz Province, the center of Iran, emphasizing their zoonotic aspects.

RESULTS

Sixty-two killed rodents by local farmers belonging to five species were collected, among which 24 were identified as Mus musculus, 15 as Meriones persicus, 12 as Meriones libycus, 10 as Apodemus witherbyi, and 1 as Dryomys nitedula. Of them, 30 (48.4%) were infected with at least one helminth species. Rodents were infected with Hymenolepis diminuta (42%), Syphacia obvelata (21%), Hymenolepis nana (17.7%), Heligmosomoides polygyrus (9.6%), Trichuris muris (8%), and as well as a capillariid nematode that was isolated for the first time from D. nitedula in Iran. The findings of the present study revealed a significant intestinal helminthic infection of rodents in Taleqan County. Improving hygiene practices, and making a preventive attitude can be helpful to reduce the hazards of rodent-borne diseases in the area where humans, livestock, and synanthropic rodents are living close to each other.

Large-extended 2D supramolecular network of dipoles with parallel arrangement on a Si(111)-B surface

We have investigated the self-assembly of a strong dipolar molecule (LDipCC) on the semiconducting Si(111)-B surface with scanning tunneling microscopy (STM), density functional theory (DFT) calculations and STM simulations. Although the formation of an extended two-dimensional network was clearly revealed by STM under ultra-high vacuum, the assignment of a specific STM signature to the different terminal groups from the LDipCC molecular unit required a complete analysis by numerical simulations. The overall observed assembly is explained in terms of STM contrasts associated with the molecular structure of LDipCC and the molecule-surface interactions. To distinguish the relative arrangement of the dipolar molecules within the assembly, a rational combination of experimental results and electronic structure calculations allows us to identify a single adsorbed LDipCC phase in which the molecular dipoles are homogeneously arranged into a parallel fashion on the Si(111)-B surface.

Structural, electronic, and magnetic properties of the Fe-doped GaP nanotubes

In this work we aimed to study the structural, electronic, and magnetic properties of the Fe-doped GaP nanotubes (GaPNTs). The method, utilized in this work is based on first-principle calculations that are applied to the case studies; (5,5) armchair, (8,0) zigzag GaPNTs, and Fe-doped GaPNTs. The results of simulation show that there is distortion around Fe impurity with respect to the pristine GaPNTs for Fe-doped (5,5) and (8,0) GaPNTs. The total density of states (DOS) indicates that Fe-doped GaPNTs show the metal behavior. Furthermore, it is perceived that both Fe-doped (5,5) and (8,0) GaPNTs are magnetic systems while pristine GaPNTs do not show magnetic behavior. The study suggests that such Fe-doped nanotubes may be useful in nanomagnets and spintronics.

Post-traumatic stress disorder: a neglected health concern among commercial motor vehicle drivers

BACKGROUND

Post-traumatic stress disorder (PTSD) is an anxiety disorder that may develop following a trauma. Iranian commercial motor vehicle drivers experience many road traffic accidents during their working life; this may increase the probability for developing PTSD, which in turn may lead to increased human errors as well as decreased work efficiency.

OBJECTIVE

To examine the prevalence of PTSD and its associated factors among a group of Iranian commercial motor vehicle drivers.

METHODS

In a cross-sectional study, 424 drivers who referred to participate in an annually training program were selected using a simple random sampling technique. They were requested to complete the Persian version of PCL-C and a data collection sheet about their occupational and demographic features.

RESULTS

385 (90.8%) of 424 studied drivers completed the study. 265 (68.8%) of the drivers had first-grade driving license. The mean±SD on-the-job daily driving was 10.2±2.8 h. 74 of 385 (19.2%; 95% CI: 15.3%-23.2%) met the PTSD criteria. Higher age and job experience as a professional driver, and having past history or past familial history of psychiatric disorders, were independent predictors of developing PTSD. The disease was more prevalent among drivers with first-grade driving license.

CONCLUSION

The prevalence of PTSD among Iranian commercial motor vehicle drivers is higher than the figures reported elsewhere. Measures to diagnose of such drivers and to ensure optimum follow-up of victims before return to professional driving should be considered.