Nashwa Elshaer

Dr. Nashwa Elshaer


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
23 March 2020 in Nanomaterials
Verified
Journal Article
Open access
PDF file
Mohamed T. El-SaadonyMohamed T. El-Saadony
Mohamed T. El-Saadony
Mohamed E.  Abd El-HackMohamed E. Abd El-Hack
Mohamed E. Abd El-Hack
Ayman TahaAyman Taha
Ayman Taha
MFMoustafa Fouda
Moustafa Fouda
JAJamaan Ajarem
Jamaan Ajarem
NENashwa Elshaer
Nashwa Elshaer
In spite of great developments in the agricultural field and plant productivity in the last decades, the concern about the control of agricultural pests is still continuous. However, pest management is expected to have more effects from nanomaterials by providing innovative solutions. The current study confirms the biotransformation of copper nanoparticles (CuNPs) using a cell-free culture extract of metal copper-resistant bacteria Pseudomonas fluorescens MAL2, which was isolated from heavy metal-contaminated soils collected from Sharqia Governorate, Egypt. The local screened bacterial isolate, Pseudomonas fluorescens MAL2, is similar to Pseudomonas fluorescens DSM 12442T DSM. After optimization of growth conditions, F-Base medium was found to be the best medium and pH 7, temperature 35 °C, concentration of CuSO4·5H2O 300 ppm, 10 mL supernatant: 40 mL CuSO4·5H2O (300 ppm), and reaction time 90 min were recorded as the best growth conditions to the fabrication of CuNPs. The formed CuNPs were characterized using initially visual observation of the change in the color of the reaction mixture from blue color to the dark green as an indication of CuNPs biotransformation. Then, UV–Vis spectroscopy showed a maximum absorption at 610 nm under the optimum conditions performed. Transmission Electron Microscopy (TEM) revealed the formation of spherical aspect with size ranges from 10:70 nm; moreover, Energy Dispersive X-ray spectroscopy (EDX) indicated the presence of CuNPs and other elements. In addition, the presence of alcohols, phenols, alkenes, and amines is confirmed by Fourier-Transform Infrared spectroscopy (FTIR) spectroscopy analysis. Dynamic Light Scattering (DLS) supported that the Zeta-average size of nanoparticle was 48.07 with 0.227 PdI value. The Zeta potential showed −26.00mV with a single peak. The biosynthesized CuNPs (Bio CuNPs) showed toxicity against the stored grain pest (Tribolium castaneum), where LC50 value was 37 ppm after 5 days of treatment. However, the negligible effect was observed with chemical synthesis of CuNPs (Ch CuNPs) at the same concentration. The results suggest that Bio CuNPs could be used not only as a biocontrol agent, but also as an ecofriendly and inexpensive approach for controlling the stored grain pests.

11 October 2021 in Saudi Journal of Biological Sciences
Verified
Journal Article
Open access
RERamadan M. El-Ashry
Ramadan M. El-Ashry
Mohamed T. El-SaadonyMohamed T. El-Saadony
Mohamed T. El-Saadony
AEAhmed E.A. El-Sobki
Ahmed E.A. El-Sobki
AEAmira M. El-Tahan
Amira M. El-Tahan
SASaad Al-Otaibi
Saad Al-Otaibi
NENashwa Elshaer
Nashwa Elshaer
Nemours effective management tactics were used to reduce world crop losses caused by plant-parasitic nematodes. Nowadays the metallic nanoparticles are easily developed with desired size and shape. Nanoparticles (NPs) technology becomes a recognized need for researchers. Ecofriendly and biosafe SiNPs are developed from microorganisms. Recently, silicon nanoparticles (SiNPs) have gained novel pesticide properties against numerous agricultural pests. This study assessed the biosynthesis of SiNPs from Fusarium oxysporum SM5. The obtained SiNPs were spherical with a size of 45 nm and a negative charge of −25.65. The nematocidal effect of SiNPs against egg hatching and second-stage juveniles (J2) of root-knot nematode (RKN) (Meloidogyne incognita) was evaluated on eggplant,Solanum melongena L. plants. In vitro, all tested SiNPs concentrations significantly (p ≤ 0.05) inhibited the percentage of egg hatching at a different time of exposure than control. Meanwhile, after 72 h, the percent mortality of J2 ranged from 87.00 % to 98.50 %, with SiNPs (100 and 200 ppm). The combination between SiNPs and the half-recommended doses (0.5 RD) of commercial nematicides namely, fenamiphos (Femax 40 % EC)R, nemathorin (Fosthiazate 10 % WG) R, and fosthiazate (krenkel 75 % EC) R confirmed the increase of egg hatching inhibition and J2 mortality after exposure to SiNPs (100 ppm) mixed with 0.5 RD of synthetic nematicides. The findings suggest that the combination between SiNPs, and 0.5 RD of nematicides reduced nematode reproduction, gall formation, egg masses on roots and final population of J2 in the soil. Therefore, improving the plant growth parameters by reducing the M. incognita population.

27 September 2022 in Life
Verified
Journal Article
Open access
PDF file
AHArwa A. Hassan
Arwa A. Hassan
KSKarima Bel Hadj Salah
Karima Bel Hadj Salah
EFEsraa M. Fahmy
Esraa M. Fahmy
DMDoaa Abd Elraouf Mansour
Doaa Abd Elraouf Mansour
SASally Abdelhamid
Sally Abdelhamid
NENashwa Elshaer
Nashwa Elshaer
Chlorpyrifos (CPF) is a common organophosphorus insecticide. It is associated with negative consequences such as neurotoxicity and reproductive injury. This study aimed to observe the ability of olive leaf extract to attenuate chlorpyrifos toxicity, which induced neuro- and reproductive toxicity in male albino rats. Olive leaf extract (OLE) exhibits potent antioxidant and antiapoptotic properties. Twenty-two mature male rats were divided into four groups: control (saline), CPF (9 mg/kg), OLE (150 mg/kg), and CPF + OLE. Treatment was administered orally for 80 days. The CPF significantly reduced serum sex hormones, sperm counts and motility, high oxidants (MDA), and depleted antioxidants (GSH, SOD, TAC) in the brain and testes homogenate; additionally, it decreased serum AChE and brain neurotransmitters, increased Bax, decreased Bcl-2, and boosted caspase-3 immune expression in neural and testicular cells. Immunological expression of Ki 67 in the cerebrum, cerebellum, choroid plexus, and hippocampus was reduced, and α-SMA in testicular tissue also decreased. Histopathological findings were consistent with the above impacts. OLE co-administration significantly normalized all these abnormalities. OLE showed significant protection against neural and reproductive damage caused by CPF.

20 October 2022 in Egyptian Academic Journal of Biological Sciences, B. Zoology
Verified
Journal Article
Open access
PDF file
EMEl-Saadany H. M.
El-Saadany H. M.
GKGamila A.M. Kotb
Gamila A.M. Kotb
AIA. Ibrahim
A. Ibrahim
NENashwa Elshaer
Nashwa Elshaer
Bacillus thuringiensis subsp. kurstaki (Btk) is well-known and widely used as a biological insecticide. Registration of biopesticides with the national pesticides broad must be laboratory testing for acute toxicity as short-term and long-term health effects. Acute oral toxicity tests were carried out on rats with d-endotoxin and formulation (9.4% WP) of Btk based on the Organization for Economic Co-operation and Development (OECD). The purpose of this study is to assess the biosafety of the bioinsecticide Btk (d-endotoxin and 9.4% WP) in adult rats after a single oral dose based on hematotoxicity, hepato- renal toxicity, and the lipid profile. Results illustrate that most haematological parameters increased in treated rats. Compared to the control, liver enzymes (AST, ALT, and ALP) and globulin (Glb) concentration were increased and decreased in male rats subjected to both kinds of Btk. While female rats treated with both Btk products are showing a significant elevation in ALP, total protein (TP), albumin (Alb), and Glb levels versus the levels of ALT and AST. Urea concentrations decreased significantly in all treated rats, but Creatinine levels appeared to remain unchanged. Moreover, there was a decline and elevation in the serum of lipid profiles (T cholesterol and HDL) in treated male rats and female rats, respectively. LDL levels increased in treated male animals, while they decreased in treated females. All treated animals displayed negligible modifications in tissue somatic index, except a slight increase in lung weights when compared to the control. Contradictory, the body weight gain levels were reduced in all treated animals compared to untreated. In addition, there are no mortality or pathogenicity symptoms in all treated animals. These findings suggest that both treatments can induce hepato- renal toxicity and hematotoxicity with side effects on lipid profile aspects. Therefore, additional research, including subacute and chronic studies, is recommended

12 November 2019 in bioRxiv
Verified
Preprint
Open access
PDF file
SRSaray Ramos
Saray Ramos
FCFleur Chelemen
Fleur Chelemen
VPViviana Pagone
Viviana Pagone
NENashwa Elshaer
Nashwa Elshaer
PIPaula Irles
Paula Irles
Maria-Dolors PiulachsMaria-Dolors Piulachs
Maria-Dolors Piulachs
Eyes absent (Eya), is a protein structurally conserved from hydrozoans to humans, for which two basic roles have been reported: it can act as a transcription cofactor and as a protein tyrosine phosphatase. Eya was discovered in the fly Drosophila melanogaster in relation to its function in eye development, and the same function was later reported in other insects. Eya is also involved in insect oogenesis, although studies in this sense are limited to D. melanogaster , which has meroistic ovaries, and where eya mutations abolish gonad formation. In the present work we studied the function of eya in the panoistic ovary of the cockroach Blattella germanica . We show that eya is essential for correct development of panoistic ovaries. In B. germanica, eya acts at different level and in a distinct way in the germarium and the vitellarium. In the germarium, eya contributes to maintain the correct number of somatic and germinal cells by regulating the expression of steroidogenic genes in the ovary. In the vitellarium, eya facilitates follicle cells proliferation and contributes to regulate the cell program, in the context of basal ovarian follicle maturation. Thus, eya -depleted females of B. germanica arrest the growth and maturation of basal ovarian follicles and become sterile.