Tetrameric DABCO™-Bromine: an Efficient and Versatile Reagent for Bromination of Various Organic Compounds

Tetrameric DABCO™-bromine is a powerful brominating agent but shows reasonable selectivity with certain substrates. The selective bromination for activated aromatic compounds and alkenes is reported. Synthesis of -bromo ketones and nitriles has also been achieved by using this reagent and the results are also reported. All products reported were obtained in good to excellent yields.KEYWORDS: Tetrameric DABCO™-Bromine, TDB, solid supports, bromination, -bromination, 1,2-dibromo compounds, bromohydrin

Geometric morphometric analysis of the molars in three species of the genus Mus (Mus) (Rodentia, Muridae) based on the outline method

The relatively new technique of outline-based geometric morphometrics was applied in a study of the variation in the shape of the upper and lower molars among 122 mice, belonging to one species from Iran (Mus musculus) and two species from Europe (Mus macedonicus, Mus spicilegus). Differentiation of specimens based on molar shape was highly dependent on the details of the shape information. Among molars, the second upper and first lower molars are better at separating the species. This method provides a useful way to distinguish species based on the outline of their molars.Keywords: shape variation; upper and lower molars; mice; Iran; Europe

Species diversity and ecological studies of phytoplankton in the Bazangan Lake

Bazangan, the Khorasan largest natural lake, is located in Northeast. 120km from Mashhad with the area of 690000m2. The purpose of this study was to characterize ecological aspects and to compare seasonal variations in species diversity of phytoplanktons in the surface water of littoral zone in the Bazangan lake. Samples were collected from eleven stations in each season during the year 2002. Some ecological factors such as pH. EC, salinity, hardness of water, nutrients and water temperature were measured. Four macroalgae and 33 phytoplankton species belonging to 5 algae groups viz. Chrysophyta (21 species). Chlorophyta (7 species), Cyanophyta (4 species) and Pyrrophyta (1 species) were identified. Diatoma tennis. Fragillaria crotonensis, Lilothrix subtilissinia and Merisinopodia punctata had the most species abundance. Comparing to other groups, Chrysophyta was abundant in all seasons mostly in the spring and summer. Different numerical indices of diversity such as species richness, evenness and diversity as well as parametric families of diversity were obtained in different seasons based on the abundance data of phytoplanktons. The results showed that the highest species diversity of the phytoplanktons could be seen in the summer and autumn. The Bazangan is classified as an oligothroph and a subsaline lake

Determination of developmental stages of embryo in the sea urchin, Echinometra mathaei

Sea Urchin is one of the most useful tools in developmental biology studies because this organism has the simplest kind of developmental stages. We aimed to determine developmental stages and timetable of Echinometra mathaei embryo (the species of Persian Gulf). The spawning of E. mathaei was induced by 0.5M KCl injection (1ml) into the coelomic cavity. After fertilization, embryos were placed in beakers and were incubated at 29°C and a salinity of 39 ppt until embryos reached the pluteus stage. The developmental stages of embryos and the timing of each stage including cleavage, morulae, blastula, gastrula, prism and pluteus larvae were studied under the microscope. Our results showed that after 30 hours from fertilization time, the embryos developed to pluteus larvae. E. mathaei had the shorter development time in comparison to the other Sea Urchin species. Therefore, it may be appropriate as a model organism in biological researches

Studying of Artemia sp. production in Gonabad salt-waters, Kavir-e-Namak Basin, eastern Iran

A preliminary stock assessment of Artemia sp. has been carried out for the first time in Gonabad salt-waters, situated in the Kavir-e-Namak Basin, a salty desert in eastern Iran. We conducted seasonal analysis of physico-chemical and biological properties of salt-waters for two stations in the study area over the year 2002. Hand-held plankton net was used with a mesh size of 20mm to collect phytoplankton samples. We identified five families of phytoplankton such as: Nitzschiaceae, Naviculaceae, Cymbellaceae, Oscillatoriaceae and Nostocaceae in the salt-waters of the area. Phytoplankton species from family Nitzschiaceae were the most abundant, present in the waters year-round and comprised the main food item for Artemia sp. in the region. Phytoplankton abundance was highest during spring and earlier of autumn and Artemia sp. showed a fluctuation in their density over the year, increasing gradually from spring to winter in one station and from spring to autumn in another. Considering the optimal physico-chemical and biological properties for Artemia sp. production and development, we concluded that the best time period for Artemia sp. production start from May to November in Kaleshor area around the Kavir-e-Namak Basin

Transplacental transmission of SARS-CoV-2 infection: A case report from Iran

We report a case of SARS-CoV-2 vertical transmission through the placenta in a neonate whose mother had non-M3 acute myeloid leukemia (AML) that was complicated with Covid-19 in the last trimester. Viral load in nasopharyngeal swabs from mother and neonate were high. Real-time PCR of the fetal side of the placenta was positive for SARS-CoV-2, which makes it possible to consider this case as a congenital case of SARS-CoV-2 infection that is transmitted through vertical transmission. © 2020, Author(s)

Internet addiction: a 21st century epidemic?

Internet addiction, while not yet officially codified within a psychopathological framework, is growing both in prevalence and within the public consciousness as a potentially problematic condition with many parallels to existing recognized disorders. The rapid and unfettered increase in the number of people accessing a relatively unrestricted internet substantially increases the possibility that those suffering with an underlying psychological comorbidity may be at serious risk of developing an addiction to the internet, lending further credence to this hitherto understudied condition. In this commentary, I outline my recommendations for improved diagnosis, study and prevention of internet addiction

Problematic Internet Use in High School Students in Guangdong Province, China

BACKGROUND: Problematic Internet Use (PIU) is a growing problem in Chinese adolescents. There are many risk factors for PIU, which are found at school and at home. This study was designed to investigate the prevalence of PIU and to investigate the potential risk factors for PIU among high school students in China. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional study was conducted. A total of 14,296 high school students were surveyed in four cities in Guangdong province. Problematic Internet Use was assessed by the 20-item Young Internet Addiction Test (YIAT). Information was also collected on demographics, family and school-related factors and Internet usage patterns. Of the 14,296 students, 12,446 were Internet users. Of those, 12.2% (1,515) were identified as problematic Internet users (PIUs). Generalized mixed-model regression revealed that there was no gender difference between PIUs and non-PIUs. High study-related stress, having social friends, poor relations with teachers and students and conflictive family relationships were risk factors for PIU. Students who spent more time on-line were more likely to develop PIU. The habits of and purposes for Internet usage were diverse, influencing the susceptibility to PIU. CONCLUSIONS/SIGNIFICANCE: PIU is common among high school students, and risk factors are found at home and at school. Teachers and parents should pay close attention to these risk factors. Effective measures are needed to prevent the spread of this problem