المنشورات العلمية لـجامعة طرابلس

احصائيات منشورات جامعة طرابلس

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    وثيقة

Nigella sativa oil alleviates mouse testis and sperm abnormalities induced by BPA: potentially through redox homeostasis?

Background & aim: There is significant evidence indicating that endocrine disrupted bisphenol A (BPA) seriously endangers human health. In males, BPA affects testis architecture and sperm quality, and ultimately reduces fertility. This study explored the therapeutic potential of Nigella sativa (NS) seed extract on testis and sperm abnormalities in BPA-exposed mice and characterized the underlying mechanism. Methods: Forty male Swiss albino mice (5.5 weeks old, N = 8 per group) were randomly divided into five groups: Group I, normal control, Group II, vehicle control (sterile corn oil); Group III, NS-exposed (oral 200 mg/kg); Group IV, BPA-exposed (oral 400 μg/kg body weight); Group V, BPA + NS-exposed mice. Animals were treated for 6 weeks and sacrificed for biochemical and histological examination. Results: The results indicated that BPA exposure results in significant testis and sperm abnormalities. Specifically, BPA promoted a marked reduction in the body and testis compared with the control group. Histopathological findings showed that BPA caused a widespread degeneration of spermatogenic cells of the seminiferous epithelium, decreased sperm counts and motility, and augmented sperm abnormalities, and whereas little alteration to sperm DNA was observed. In addition, BPA increased the levels of the lipid peroxidation marker, malondialdehyde (MDA), and reduced the levels of the antioxidant marker, reduced glutathione (GSH). Treatment with NS oil extract during BPA exposure significantly alleviated testis and sperm abnormalities, reduced MDA levels, and enhanced GSH levels. Conclusions: The results demonstrate that NS oil protects mice against BPA-induced sperm and testis abnormalities, likely by suppressing levels of the oxidative stress marker, MDA, and enhancing the levels of the antioxidant marker, GSH.
Mohamed A M Al Griw (5-2022)
موقع المنشور

Isolation of Verotoxigenic Escherichia coli O157 from poultry

The study presents results obtained by examination of cloacal swabs from poultry for the presence of verotoxigenic stains of E.coli O157:H7. Twenty samples (9.2%0 of 216 samples examined were positive for E.coli O157. Out of the twenty E.coli O157, 19 strains were positive for the production of both verotoxins (V1 and V2). However, none of them was positive for the presence of H7 antigen.
Hesham Taher Naas(1-2022)

Overall Equipment Effectiveness Evaluation and Simulation Modeling Application for Beverages Production Line

Abstract Overall equipment effectiveness (OEE) is a well-accepted measure of performance in industry. In this thesis, the components of OEE were calculated over a period of 28 months using failure and repair data gathered from food and beverages packaging line. The failure and repair data of the packaging line were statistically analyzed to understand the nature of the failure patterns, and to estimate the reliability and maintainability characteristics of the packaging line in precise quantitative terms, moreover, the best fit distribution for TBF and TTR based on failure data were computed, these distributions were included in the simulation model to describe the reliability behavior of the packaging line. Among the techniques to tackle maintenance and reliability issues, simulation can undoubtedly play an important role as it provides what-if analysis and hence help to evaluate quantitative benefits. This thesis also describes the modelling of machine breakdown behavior in industrial machines, a packaging line machines in the Aseptic Liquid Food (ALF) factory. The model also examines three important scheduled tasks (parameters) influence on packaging machines to study the correlation between these parameters and the occurrence of breakdown. Results show that the component Availability of the OEE metric should be improved to optimise the productivity and the efficiency of the line. the model results of failure time metrics (i.e. MTBF and MTTR) were validated using Output Analyzer template within Arena simulation software; and the results were near actual figures of collected data. The results of second experiment model showed a decrease in breakdown occurrences compared to first experiment, however, the scheduled tasks usage rate didn't correlate to breakdown occurrences, indicating the need to study and analyze different possible reasons of breakdown occurrence. Keywords: TPM, WCM, OEE, Simulation and modelling
Tajedeen Ramadan Own(1-2022)

دراسة خصائص بعض المركبات الليبدية المحلية و المستوردة و دورها في صناعة الصابون والمنظفات الصناعية

يعتمد البحث على اجراء دراسة للمركبات الليبدية التي لها دورا مهما في حياة الانسان كمادة غذائية غنية باطاقة و في المنتجات المختلفة الشائعة كصناعة الصابون والمنظفات الصناعية و مواد التجميل و صناعة حبر لطابعة و لأهمية الليبديات تم تحليل عشر عينات من الدهون و الزيوت الحيوانية و النباتية و دهن الزبدة ودهن البقر (بالعلف المحلي و بدون علف )زيت الزيتون المحلي و زيت الذرة corn oil ،وزيت عباد الشمس sun flower وزيت الكتان ،زيت القطن ،زيت الفول السوداني ،زيت الصويا ،زيت النخيل (وزيت الخروع المحلي )،والتي لها دورا مهما في صناعة الصابون وقدرت درجة التصبن عن طريق معايرة الأحماض الدهنية الحرة في وزنة قدرها (5 جرام )من الدهن أو زيت بواسطة معايرتها بحمض الهيدروكلوريك تركيزه (0.52N) وكذلك تم حساب رقم الأسترة ،واالرقم اليودي لكل العينات باستخدام محلول تركيزه0.1 عياري من ثايو سلفات الصوديوم Na2S2O3.5H2O والدليل المستخدم النشأ1%.
أأبوبكر ابراهيم أبوبكر الحاجي, فرج عبد الجليل العارف المودي, شعبان جاب الله سعيد الاسطى(3-2022)
موقع المنشور

In Vitro Antibacterial Activity of Flavonoid Extracts of Two Selected Libyan Algae against Multi-Drug Resistant Bacteria Isolated from Food Products

Abstract This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemorrhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.
Hesham Taher Naas(1-2017)
عرض موقع المنشور

Extent of pathogenic and spoilage microorganisms in whole muscle meat, meat products and seafood sold in Libyan market

Abstract Background: Whole muscle meat, meat products, and seafood contain different nutrients in adequate quantity providing a better environment for presence and replication of different microorganisms. There are underreported and inaccurate estimations of foodborne diseases due to the lack of effective surveillance systems in Libya. Aim: To determine the extent of microbiological contamination of whole muscle meat, meat products, and seafood. Methods: A total number of 731 samples of retail meat were collected from different stores in four cities in Libya. Samples were analyzed for aerobic plate count and subjected to microbiological enumeration and isolation techniques, followed by molecular identification by PCR and partial sequencing of 16S rDNA. Results: The results showed contamination of samples with enteric and spoilage bacteria. Fifteen genera of spoilage bacteria yielded 149 isolates which were detected and identified by PCR and partial sequencing of 16S rDNA as: Proteus spp., Provedencia spp., Raouttella ornithinolytical, Citrobacter spp., Enterobacter spp., Morganella morgi, Shewanella algea, Rhodobacter capsulatus, Listonella pelagia, Kluyvera spp., Pectobacterium spp., Brenneria spp., Klebsiella spp., Acintobacter radioresistens, and Pantoea spp. While for pathogenic bacteria, 143 isolates distributed among nine genera were identified by PCR and partial sequencing of 16S rDNA as: Bacillus spp., Escherichia spp., Shigella spp., Enterococci spp., Cronobacter spp., Staphylococci spp., Salmonella spp., Aeromonas spp., and Vibrio spp.. Many isolated bacteria are zoonotic bacteria with high importance for public health. Conclusion: Excessive handling and processing of meat and meat products seems to be one of the poorest microbiological qualities. These findings ought to be helpful in risk assessments and quality assurance of meat in order to improve food safety.
Hesham Taher Naas(9-2020)
عرض موقع المنشور

Enterohemorrhagic Escherichia coli O157 in milk and dairy products from Libya: Isolation and molecular identification by partial sequencing of 16S rDNA

Aim: The aim of this work was to isolate and molecularly identify enterohemorrhagic Escherichia coli (EHEC) O157 in milk and dairy products in Libya, in addition; to clear the accuracy of cultural and biochemical identification as compared with molecular identification by partial sequencing of 16S rDNA for the existing isolates. Materials and Methods: A total of 108 samples of raw milk (cow, she-camel, and goat) and locally made dairy products (fermented cow’s milk, Maasora, Ricotta and ice cream) were collected from some regions (Janzour, Tripoli, Kremiya, Tajoura and Tobruk) in Libya. Samples were subjected to microbiological analysis for isolation of E. coli that was detected by conventional cultural and molecular method using polymerase chain reaction and partial sequencing of 16S rDNA. Results: Out of 108 samples, only 27 isolates were found to be EHEC O157 based on their cultural characteristics (Tellurite- Cefixime-Sorbitol MacConkey) that include 3 isolates from cow’s milk (11%), 3 isolates from she-camel’s milk (11%), two isolates from goat’s milk (7.4%) and 7 isolates from fermented raw milk samples (26%), isolates from fresh locally made soft cheeses (Maasora and Ricotta) were 9 (33%) and 3 (11%), respectively, while none of the ice cream samples revealed any growth. However, out of these 27 isolates, only 11 were confirmed to be E. coli by partial sequencing of 16S rDNA and E. coli O157 Latex agglutination test. Phylogenetic analysis revealed that majority of local E. coli isolates were related to E. coli O157:H7 FRIK944 strain. Conclusion: These results can be used for further studies on EHEC O157 as an emerging foodborne pathogen and its role in human infection in Libya.
Hesham Taher Naas(11-2016)
عرض موقع المنشور

Comparison between Two Different Conventional Methods for Coliform count in Raw Milk and Locally Made Soft Cheese in Tripoli, Libya

Seventy five random samples were collected (25 raw milk, 50 local different made soft cheeses) from different supermarkets in Tripoli- Libya. The Objectives of this study were: (i)- to clear the incidence rate and count of coliforms as an indicator microorganisms for fecal contamination in raw milk and locally made soft cheese samples manufactured by traditional methods and (ii)- to make comparison between the most famous two conventional methods used for counting of such group of microorganisms. Coliforms were recovered from all the raw milk samples using the two methods (most probable number using liquid lauryl sulphate broth and sold plating method using violet red bile agar). The mean count for the former media was 28x106 while for the later one was 15x106 cfu/ml. For cheese samples (locally made Ricotta and Maasora), positive samples were 78% (39 samples) using MPN method, while 76% (38 samples) using sold plating media VRBA. The mean coliform count for positive samples using MPN was 18x107 cfu/g, while for VRBA plates the mean count for positive samples was 21x106 cfu/g. all counts were higher using MPN than VRBA for the same sample in both raw milk and cheese samples, although, clear difference in count between the two methods was recorded in cheese than that in raw milk, conditions that may affect the count in both raw milk and cheese were discussed. Factors that may limit
Hesham Taher Naas(1-2007)