Libyan Journal of Science &Technology

Introduced species in Flora of Libya 1

Abdulhamid K. Alzerbia — 2022-09-18

Introduced Species in Flora of Libya were reported in this study, the results showed of 361 species of introduced plants (17.72%) from the species recorded in the flora of Libya. These species belong to 253 genera and 89families. Six of these families belong to gymnosperms and the rest belong to angiosperms. The recorded species were introduced for different purposes, such as food, fodder, ornamental, and windbreaks. These species established and become part of the Libyan flora. Some of which are poisonous to humans or animals and some are a strong competitor or allopathic to local plants. In this paper, a list of introduced species, the origin of these species, and the purpose of their introduction will be included.

The epidemiological characteristics of (COVID-19), recommendations to contain the out- break in early stage and prevent the disease from getting out of control in Libya. 1

Ekram Ben Sauod — 2022-09-18

Coronaviruses (CoVs) are a large family of viruses that cause illness ranging from mild com-
mon cold to more severe diseases such as acute respiratory distress syndrome (SARS ) in China

in 2003, Middle East Respiratory Syndrome (MERS) in Kingdom of Saudi Arabia (KSA) in 2012,

and Coronaviruses disease 2019 (COVID-19). COVID-19 is caused by SARS- CoV-2, represent-
ing a potentially fatal disease that is of great global public health concern. COVID-19 is sug-
gested to be of zoonotic origin due to the exposure to the wet animal market in Wuhan City in

China. Human-to-human transmission of the COVID-19 and direct contact the main mode of
transmission. Therefore, the rapid spread of COVID-19 between human transmissions is a big
challenge worldwide. As the disease is not completely known, the virus may take off measures

by the WHO and the national CDC of Libya should be implemented to suppress the transmis-
sion. Ongoing investigations worldwide are important for identifying the animal source and

reservoir the disease. Currently no drugs licensed for the treatment or prevention of COVID-
19, the WHO and other health organizations should create vaccine or treatment for COVID-19.

We highlight in this review article the epidemiology, mode of transmission, symptoms, and
recommendations to contain the outbreak in the early stage and prevent the disease from
getting out of control in Libya.

Hematological and gastrointestinal protection effects of ginger rhizome on whole-body exposure of gamma radiation in mice1

Huda Gargouma — 2022-09-18

Radiation can induce acute radiation sickness in different ways. In this study, we investigated
the radio-protective efficacy of ginger extract (GE) against the gamma (γ) ray-induced damage
on mice. The source of gamma radiation was cobalt 60 (Co-60). GE was administered to mice
at a dose of 5 ml/kg intraperitoneally (IP) for 5 consecutive days before exposing them to 8
Gray (Gy) (unit of ionizing radiation dose) of Co-60-gamma-radiation. Mice treated with GE
before irradiation (pretreated group) showed a significant decrease in the mortality of lethally

irradiated mice. Moreover, spleen weight was significantly increased. Besides, the GE treat-
ment facilitated the recovery of white blood cells (WBC), and hemoglobin (HGB) cell number.

Altogether, the findings indicated that ginger has remarkable effects on mice against hemato-
poietic suppression and gastrointestinal damage caused by irradiation.

Absorption spectra and band gap of thin film nanocrystalline ZnS semiconductor depos- ited at the water/toluene interface1

Enteisar Albrasi — 2022-09-18

This work presents a wet chemical synthesis method that uses the interface of two immiscible

liquids for the formation of a thin film of nanocrystalline ZnS semiconductor at 60°C.ZnS sem-
iconducting colloid nanoparticles, containing cysteine as a capping agent was deposited as a

thin film at the water- toluene interface. In this method, the capped ZnS with cysteine held in

contact with toluene containing octylamine. The thin film produced was characterized by UV-
visible spectroscopy. The UV-Visible absorption spectra are carried out to determine the

bandgap of ZnS colloid nanoparticles and a nanocrystalline thin film of ZnS. From optical ab-
sorption measurements, it is clear that the direct energy gap decreases from 3.92-3.82 eV, and

the size of ZnS colloid nanoparticles and nanocrystalline thin film calculated from the bandgap
energy have been in the range of 3.7 - 4.2 nm.

Antimicrobial, antioxidant and anticancer activity of Ephedra alata growing in East of Libya1

Salmin Alshalmania — 2022-09-18

Introduction: The plant Ephedra alata belongs to the Ephederiaceae family. These plants distributed in North Africa, Palestine, Libya, Egypt, Saudi Arabia, and Iraq. Ephedra alata has been commonly used in folk medicine in Libya and most of the Arabian countries for treatment of asthma, hay fever, and the common cold. Aim: This study aimed to investigate the phyto-constituents and to assess its anti-microbial, antioxidant activities, in addition, to study its cytotoxic effect. Methods: The aerial part dried of the plant was subjected to a phytochemical screening and investigated for their antimicrobial activity, antioxidant effect, and cytotoxic effects. Results: The phytochemical investigation of the methanolic extracts of Ephedra alata revealed the presence of alkaloids, carbohydrates, flavonoides, steroids, tannins, and phenolic compounds. The results of anti-microbial activity revealed that; there was a significant antibacterial activity against representatives of Gram positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa), while there was no antifungal effect against Aspergillusflavus and Candida albicans. In terms of antioxidant activity, the methanolic extract of Ephedra alata showed a significant scavenging effect on the DPPH radical, compared to gallic acid. The results showed an honest correlation between antioxidant activity and flavonoid content. The plant extract displayed a significant cytotoxic effect on MCF7with IC50 and IC90 comparing with doxorubicin as a positive control. Conclusion: The results indicated that the extract of Ephedra alata had significant antioxidant, and cytotoxic effects in addition to their antimicrobial activity

Asymptotic stability of periodic solutions for a nonlinear neutral first-order differential equation with functional delay

Haitham Makhzoum — 2022-09-18

We consider the nonlinear neutral differential equation

and use the contraction mapping principle to show the asymptotic stability of the zero solution provided that

Evaluation of the surface roughness of four different types of acrylic resin denture base materials: heat cure (HC), high impact heat cure (HIHC), heat cure clear (HCC), and clear chemical cure (CC). Part (1)

Salma Elnailia — 2022-09-18

Statement of problem: Resin-based poly (methylmetha acrylate) (PMMA) has been used instead of metallic materials for denture base construction, because of the following reasons: it is aesthetic superiority; ease of construction with very cheap equipment as well as it is ease of repair. However, despite the superiority of the acrylic resin as denture base material, it still has some limitations such as low surface roughness, which causes adhesion of oral microorganisms.

The aim: To assess and compare the surface roughness of four different types of acrylic resin denture base materials: heat cure (HC), high impact heat cure (HIHC), heat cure clear (HCC), and clear chemical cure (CC).

Material and methods: Twenty-five discs measuring 11 mm in diameter and 3 mm in thickness for each different type of acrylic resins were fabricated. All samples were polished to different roughness parameters, consisting of 600 and 1200 surface polishers. The average surface roughness (Ra) was measured using a profilometer, and the average mean was calculated. Furthermore, the surface characteristics were viewed by a scanning electron microscope (SEM).

Results: For statistical analysis, ANOVA single factor was used. The 600 surface polishers of all types (HC, HIHC, CC, and HCC) demonstrated higher average means of surface roughness than the 1200 surface polishers. The P-value of the average surface roughness between the 600 and 1200 surface polisher of each type of acrylic denture was significant in HIHC, CC and HCC (P>0.018, P>0.006, P>0.013 respectively).

Conclusion: The surface texture differs according to the types of resin material; however, HIHC had by far the highest average surface roughness

The effect of magnetic treatment on some physical properties of Seawater1

Seham Mohammed — 2022-09-18

The effect of the magnetic field (14500 Gauss or 1.45 T) on density, electrical conductivity, and viscosity of seawater concentrations (20, 50, and 80%) is studied here. The results show that magnetic treatment causes a significant increase in the density and electrical conductivity of seawater, while the viscosity is decreased as compared to the ordinary seawater without magnetic treatment. The experiment was carried out during the winter of 2019, at the laboratory of physics, College of Sciences, Ajdabiya University, Libya.

Bacterial contamination of fast food shawarma sandwiches in local restaurants in Ben- ghazi city, Libya 1

Soad Ajaja — 2022-09-18

Sandwiches are widely consumed as part of the international food culture, therefore, the investigation of microbiological quality and hygienists are essential steps for risk factor determination of food-borne illnesses. This study investigated the bacterial contamination in 151 chicken shawarma sandwiches randomly selected from 19 restaurants located in four different regions in the city of Benghazi, including North, South, East, and the City center. The results showed that 89.4% of chicken shawarma sandwiches samples were contaminated with bacteria. The bacterial diversity showed that Klebsiella pneumoniae was the predominant bacterial species isolated from the sandwiches (24.5%), thus, it has been suggested to represent the highest source of bacterial contamination in the screened samples. The latter bacteria was followed by Escherichia coli (19.9%), Citrobacter freundii (18.8%), Bacillus sp. (9.9%), Proteus mirabilis(8.6%), Enterobactercloacae (7.9%), Pseudomonas aeruginosa (6%), Enterobacter aeruginosa (4%) and Staphylococcus aureus (0.7%). Quantification of the bacterial contamination using total plate count has revealed that Bacillus sp 1.9×105 cfu/g, E. cloacae1.8×105cfu/g, C. freundii 1.4×105 cfu/g, K. 7.3×104 cfu/g, E. coli 4.5×104 cfu/g and E. aerogenes 4.2×103 cfu/g. The bacterial sensitivity to the antibiotics showed that all tested pathogens were mostly resistant to Cloxacillin, Amoxicillin, Metronidazole and Cephalothin (86.7% to 100% of resistant). Only P. aeruginosa, Enterobacter sp., and P. mirabilis showed complete resistanceto Cefoxitin. Bacillus sp. was mostly resistant to the tested antibiotics compare to S. aureus. The results of this study demonstrated that the bacterial contamination in the tested sandwiches were relatively high and were produced under low hygienic conditions. This was supported by the finding that the increased bacterial count in the sandwiches and the high resistant level to antibiotic have indicated a high risk factor for acquiring food-borne illnesses.

Oxidative dehydrogenation of Propane over vanadium catalysts

Hanan Eghreibeel — 2022-09-18

Oxidative dehydrogenation of Propane over vanadium catalysts

Mitodepressive effect and chromosomal aberrations induced by KBrO3 on A. sativum Lroot tips

Hoda Khatab — 2022-09-18

Mitodepressive effect and chromosomal aberrations induced by KBrO3 on A. sativum
Lroot tips

Opinions and attitudes of general dental practitioners in Libya towards the intracanal separation of endodontic instruments

Ibtesam Orafi — 2022-09-18

Aim: To investigate the opinions and attitudes of general dental practitioners (GDPs) in Libya towards the separation of endodontic instruments.

Methodology: A pilot questionnaire was carried out on 20 GDPs to ensure that the questions were easily understood. The sample size comprised of 275 systematically selected GDPs, the questionnaire included both close-ended and partially closed-ended questions in four groups: demographics; a pattern of practice and experience of instrument fracture; management of fractured instruments and, finally, unsuccessful management of fractured instruments. Data were analyzed using the chi-square test at P≤ 0.05.

Results: The overall response rate was 97%. 90.2% of respondents had an experience of instrument fracture. The majority of respondents inspect the instrument before and during treatment. Only 4.9% of respondents reported that they would retrieve separated instruments located in the apical part of root canals. 43.6% of GDPs reported the use of the H-files Braiding technique for the removal of fractured instruments. Excessive removal of dentine was considered as the most common complication of the retrieval of fractured instruments (50.7%). 49.6% of respondents would prefer to leave the unsuccessfully removed file in the canal.

Conclusion: Separation of endodontic instruments is a procedural error that frequently occurs during endodontic treatment. The GDPs need to be familiar with the conservative techniques, which are available to retrieve separated instruments. All efforts should be made to upgrade clinicians’ skills and knowledge with regards to the use and retrieval of endodontic instruments via hands-on and continuing education courses.