Rafidain journal of science

Simple and accurate spectrophotometric method for the estimation of benzocaine (BENZ) as pure form and in its formulation (ear drops) in aqueous solution has been developed. The method is based on the diazotization of BENZ, with equivalent amount of nitrite, in an acidic medium to yield the diazotized benzocaine. Then the diazotized benzocaine is coupled with 4-chlororesorcinol (4-CRL) reagent in basic medium to formed, an intense yellow azo dye, which is water-soluble and it has good stability. The yellow azo dye exhibits maximum absorption at 436 nm. The relationship between absorbance and concentration gave good range of determination from 10 to 50 μg BENZ in final volume of 10 ml i.e.,1 to 5 μg.ml-1with a molar absorptivity and Sandell\\\\'s sensitivity index values of 3.722104 l.mol-1. cm-1 and 0.0044 μg.cm-2 respectively, a relative error of –1.06 to +2.47% and a relative standard deviation was not more than 0.921% depending on the concentration level of BENZ, low detection limit of 0.1924 μg.ml-1 and low of quantitation value equal to 0.6416 μg.ml-1 have been estimated. The method has been applied to the estimation of BENZ in ear drop (otocol drops).

Present paper reports a theoretical study to investigate the compressional behavior of nano PbS( , , ) under high pressure by using different equations of state. The pressure dependence of these parameters for three nano PbS particles of different sizes (2.6nm, 5.4nm and 8.8nm), have been calculated by using B-M EOS, m L-J EOS and S-K EOS. Obtained results are compared with available experimental data. This comparison reveals the validity of using the well-known EOSs of bulk materials such as B-M EOS and m L-J EOS further to S-K EOS which was used for studying nano materials. The effect of particle\\\\'s size, under high pressure, have been investigated in present work. The overall results in this work let us put question mark about S-K EOS

Since December 2019, the novel Coronavirus (SARS-CoV-2), which has emerged in China, has drawn global interest due to its quick spread, which affects more than 221 countries and territories worldwide and many of external transportations. Covid-2019 is a severe acute respiratory syndrome of viral pneumonia. After the (SARS CoV-1) of the 21st Century and the Coronavirus Respiratory Syndrome of Middle East, the emergence of Covid-19 has been established as the third entrance of a potential pathogen Coronavirus. Due to a lack of proofreading activity for viral RNA polymers, single-stranded RNA viruses show a higher biological mutation rate; however, CoV has minimal proofreading abilities, as the nsp14 protein allows members of the CoV family to increase the size of the genome, unlike the other RNA viruses that are susceptible to mutations, with the exception of the Arenaviridae family.
The wide range of new discoveries has brought importance to coronavirus researches and strategic expansion is important to accept the newest innovations and advances. This review extensively summarizes the genetic structure, cause of COVID-19 infection and detection to assist with follow-up research, prevention and to provide the current information to the readers

Diatoms considered as are a phytoplankton main group of in aquatic ecosystems abundance, diversity, and productivity. Allelopathic infractions, are an important part of phytoplankton competition, allelopathy may be one of the factors affecting the structure of phytoplankton. Diatoms are known to produce a number of allelopathic compounds, such as polyunsaturated fatty acids (PUFAs), polyunsaturated aldehydes (PUAs) and polyphenolic and halogenated compounds. However, Allelochemicals (AC) are chemical substances produced by diatoms and release which affecting microorganisms in their neighborhood. These chemicals are able to prevent or encourage the co-occurring phytoplankton species growth along other organisms. Such sintering behavior affecting not just each species that replying to or making a definite chemical, but as well functioning of communities, populations, and ecosystems including defense, reproduction, competition, and predator avoidance. The current review demonstrates work of Allelopathy in diatoms and stimulated or excreted chemicals via diatom direct or indirect way to environment for maintaining their domination

The current research work was carried out to verify the role of AgNO3 silver nitrate in the germination and growth of seedlings of Leucaena leucocephala trees and to demonstrate the effects on seedlings growth indicators such as stem height, root length, number of vegetative branches and number of leaves per seedling, as well as the induction of callus from stem and leaf explant, In presence and absence of silver nitrate in MS culture media. As well as different concentrations of silver nitrate were used, the continuous growth of seedlings that were grown on MS media and supported by different concentrations of AgNO3 showed to a variation in the response in terms of stem high and root length of seedling. As for the branches that arose after the cotyledon leaves and the number of leaves for these branches, they also varied as a result of using different concentrations of nitrates. Variation of the incidence of callus with the type of plant growth regulators and their concentrations used in this research, The study also included an explanation of the role of growth regulators in creating callus from cutting the stem and leaves and comparing it with callus growing on the same nutrient media and supplied with concentrations of silver nitrate

In this study, the ability of some gram-negative bacteria isolated from different clinical samples to produce AmpC enzymes by phenotypic and molecular methods was investigated. The percentage of its occurrence was (40.6 %) by the use of cefoxitin disk as this antibiotic is used to screen for isolates that can produce this enzymes, the highest rate was for bacteria Pseudomonas aeruginosa (15.5 %) followed by Klebsiella pneumoniae (12.5 %), as for the three dimensional extraction method, the percentage of this enzyme reached (13.2 %), which depend on the use of crude enzymatic extracts instead of live microbial cells, the highest rate was for Pseudomonas aeruginosa (12.5 %) followed by Klebsiella pneumoniae (9.3 %), (37.5 %) by using disk antagonism test method which is one of the best methods for investigating these enzymes. As for molecular methods PCR assay was used to detect the blaAmpC gene encoding for this enzyme, the highest percentage was for Klebceiala pneumoniae, Pseudomonas aeruginosa reached (13.3 %).

The quality of the water of the Tigris River passing through the city of Mosul was studied, starting from the Kubba area in the north to the Yarmajah area in the south, and the Tigris River is the only water resource for the city. The Physical and Chemical propertiesof river water was conducted, which included (water temperature, pH, electrical conductivity, total dissolved solids, turbidity, dissolved oxygen and some positive and negative ions), and the Canadian Water Quality Index = (WQI) was used to express the quality of river water. Tigris as it passes in the city of Mosul. The results indicated that the water of the Tigris River passing through the city of Mosul tends towards alkalinity, and the river water has good ventilation, as the average dissolved oxygen values ranged between (8.3-9.3) mg / liter. The ions of nitrates, orthophosphates, sulphates and chlorides showed a variation in their concentrations during the study period. The rates of sodium and potassium ion concentrations ranged between (19.9-24.6) and (2.6-4.2) mg / liter, respectively. The studied water was classified as (good - moderate) for drinking, as the values of the water quality index ranged between (76.7-91.2). The index values ranged between (86.3-99.6) and the water was classified as excellent too good for the river conservation system

The nuclear binding energies of the parent and daughter nuclei, rather than their mass values, were used to calculate the positive beta decay energy ( Q_β^+-value) for a wide variety of nuclei ranging from 10≤Z≤98. The Quark-like Model (QLM) was used to compute the positive beta decay energy because it can efficiently compute the nuclear binding energies of the parent and daughter nuclei. As a result, a novel formula for calculating the positive beta decay energy was derived. The employment of a graphical representation between the practical and theoretical binding energies resulted in the generation of linear calibration equations for the parent and daughter nuclei, as well as a correction factor in MeV, resulting in the convergence of experimental and theoretical results. To produce a new final version of the (Q_β^+-value) mathematical derivations were used. The results indicated that after modifying the model utilized, there is an adequate match between the actual and theoretical values, particularly for medium and heavy nuclei, but less so for light nuclei due to the presence of magic numbers and their overlapping in this spectrum. A standard deviation of not more than (2.32) was obtained which can be considered relatively large due to the continuous spectrum of beta decay. The significance of this work lies in the possibility of calculating the values of the decay energies based on the values of the nuclear binding energies, which are calculated based on knowledge of the number of protons and neutrons, resulting in more accurate and efficient results than using the accepted mass formula, because mass values in the atomic mass units of the nuclius are difficult to obtain.

Mycorrhizae is a symbiotic relationship between roots of the most types of Vascular plants and fungi. These symbionts are characterized by a two directional movement of nutrients, whereby the fungi take up carbon while the nutrients are transferred to the plant, and thus there is a link between the plant root and the soil in infertile soils, As the growth of the Mycorrhizae in the plant roots greatly increases the surface area of the root absorption, the absorption of nutrients by the mycorrhiza fungi leads to improve plant growth and production, according to this, Mycorrhizae plants are more able to withstand environmental stresses compared to non-mycorrhizal plants. Mycorrhizae vary in form and function, including the fungus Ectomycorrhiza, Endomycorrhiza with other type, as well as increasing plant immunity and helping to reduce pathogens and harmful organisms (for example, fungi are effective against nematodes and some types of fungi, they can elimination to 60 types of pathogens that cause rot and scab) and help accelerate the flowering process and accelerate the process of crop survival and it affects the growth of green mass.