Search

Melissa officinalis L. is a cosmopolitan aromatic and medicinal plant from the Lamiaceae family, which is necessary for pharmaceutical and cosmetic production. To evaluate the impact of different harvesting times and plant materials on the essential oil content and composition of M. officinalis 4-year-old plants, the present study was conducted in Fars province, Iran, under industrial field conditions. A randomized factorial experiment with three replications was used. Each replication contained six treatments [3 harvesting of M. officinalis × 2 treatments (shade drying + fresh state)]. Hydrodistillation was used to obtain the essential oils from each treatment, which were subsequently analyzed using GC-FID and GC-MS. The results demonstrated a significant influence of harvesting times and plant materials on the essential oil content and composition of M. officinalis. The average essential oil content was 0.028% to 0.095% (w/w). At different harvest times, the fresh plant yielded a higher content of essential oil compared to the dry plant. The number of chemical constituents in the essential oils was influenced by different harvesting times and plant materials. The predominant and common constituents in all harvested plant materials were the oxygenated monoterpenes geranial (28.7-43.2%) and neral (12.9-30.9%). Based on the major compounds, the essential oils from different harvesting times and plant materials were categorized into two chemotypes: chemotype I (geranial/thymol) and chemotype II (geranial/neral). It is recommended that drying operations not be used as a post-harvest processing method to achieve the highest essential oil yield from M. officinalis. [ABSTRACT FROM AUTHOR]

In the Gasht-Masuleh area in the Alborz Mountains, gabbroic magma intruded Palaeozoic metasediments and Mesozoic sediments and crystallised as isotropic and cumulate gabbros. LREE enrichment points to relatively low degrees of mantle melting and depletion of Ti, Nb and Ta relative to primitive mantle points to an arc related component in the magma. Clinopyroxene compositions indicate MORB to arc signatures. U–Pb zircon crystallisation ages of 99.5 ± 0.6 Ma and 99.4 ± 0.6 Ma and phlogopite 40Ar/39Ar ages of 97.1 ± 0.4 Ma, 97.5 ± 0.4 Ma, 97.1 ± 0.1 Ma, within 2σ error, indicate that gabbro intrusion occurred in the (Albian-)Cenomanian (mid-Cretaceous). As active subduction did not take place in the Cretaceous in North Iran, the small volume mafic magmatism in the Gasht-Masuleh area must be due to local, extension-related mantle melting. Melting was most likely caused by far field effects triggered by roll-back of the Neo-Tethys subducting slab. As subduction took place at a distance of ~ 400 km (present distance) from the Alborz Mountains, the observed arc geochemical signatures must be inherited from a previous subduction event and concomitant mantle metasomatism, possibly in combination with contamination of the magma by crustal material. Highlights: Gasht-Masuleh gabbros calc-alkaline, extensional setting, inherited arc signature (Albian-) Cenomanian, 99 Ma zircon ages 97–98 Ma 40Ar/39Ar phlogopite ages Mantle upwelling and formation of gabbros triggered by Neo-Tethys slab roll-back causing extension [ABSTRACT FROM AUTHOR]

In this review, we intend to provide a summary of the activities of researchers in the field of Toxoplasma gondii in Iran, during the past 70 years. Most studies have been limited to epidemiological studies (mostly using ELISA and IFA methods). Designing a standard and reliable method using the specific antigens of this parasite is essential. So far, studies in the field of drug effects have not been able to introduce an effective drug with few side effects. Various types of vaccines have been developed, such as recombinant and DNA vaccines. However, none of them had a good efficacy. The use of multi-epitope vaccines as potential vaccines against toxoplasmosis is recommended. At present, limited studies have been conducted on the patterns of transmission and genetic diversity of isolated isolates in Iran. Future research to determine the genotype of T. gondii could play an important role in the study of population structure, and biological characteristics of this parasite. It is hoped that the results of this study will help control, prevent, and reduce the burden of disease caused by this parasite. [ABSTRACT FROM AUTHOR]

Given the complexities of reservoir exploration and development, it is vital to understand the geomechanical properties of the reservoir and well in the drilling operation. In constructing a mechanical model of the earth, a combination of environmental geomechanical parameters, as well as the magnitude and direction of stresses, is used. In this study, stress analysis and its effect on azimuth well in deviated drilling in an oil field located in southwestern Iran are investigated. Necessary geomechanical parameters are estimated using density and slowness logs of sonic waves (shear and compression). The Mohr–Coulomb failure criterion is followed to determine a safe mud weight window. A mechanical model of the earth is designed using laboratory data and well logging, and it is validated by the results obtained from laboratory rock mechanics using the calibrated core samples. The results show that drilling in the azimuth at about 135° with an angle of about 15° is the most stable path for the well in the carbonate reservoir formation in the studied oil field. [ABSTRACT FROM AUTHOR]

This work reports on a classroom-based study that investigated the role of field independence in the effectiveness of processing instruction. From a high school in Iran, fifty six learners were recruited and randomly assigned to an experimental and a comparison group. The former was taught through processing instruction while the latter received traditional output-based instruction on English passive. A sentence-level interpretation task was used in a pretest-treatmentposttest design to measure instructional effects. The results illustrated that processing instruction significantly improved learners' acquisition of the target structure, whereas the traditional instruction was not effective. Furthermore, no interaction was found between the learners' field independence and their performance in the immediate and delayed posttests. This could be attributed to the unique characteristic of processing instruction and its systematic nature neutralising learners' differences and consequently creating an optimum learning condition benefitting all the learners. [ABSTRACT FROM AUTHOR]