New issue of GaN nanoparticles solar cell

M.A. Qaeed,K. Ibrahim,K.M.A. Saron,M.S. Mukhlif,A. Ismail,Nezar G. Elfadill,Khaled M. Chahrour,Q.N. Abdullah,K.S.A. Aldroobi 한국물리학회 2015 Current Applied Physics Vol.15 No.4

This study involves the synthesis of gallium nitride (GaN) nanoparticles (NPs) under different low temperatures using a simple chemical method. The nanoparticles are spin coated on Si substrate to fabricate the solar cell. The FESEM images obtained indicate the presence of cubic GaN nanoparticle with average diameter of 50 nm synthesized at 90 ℃. The spin coating technique deposited n-GaN NPs/Si(111) produced a heterojunction solar cell with fill factor of 0.56 and conversion efficiency of 2.06%. Based on these results, this study proposes a novel low cost technique for the fabrication of GaN NPs solar cells.

Histopathology and Ultrastructural Findings of Fatal COVID-19 Infections on Testis

Achua Justin K.,Chu Kevin Y.,Ibrahim Emad,Khodamoradi Kajal,Delma Katiana S.,Iakymenko Oleksii A.,Kryvenko Oleksandr N.,Arora Himanshu,Ramasamy Ranjith 대한남성과학회 2021 The World Journal of Men's Health Vol.39 No.1

Purpose: To evaluate the presence and analyze the pathological changes within the testes of patients who died or recovered from severe acute respiratory syndrome coronavirus 2 (COVID-19) complications. Materials and Methods: Testis tissue was collected from autopsies of COVID-19 positive (n=6) and negative men (n=3). Formalin-fixed paraffin-embedded tissues were stained with hematoxylin and eosin (H&E) and subjected to immunofluorescence for angiotensin-converting enzyme 2 (ACE-2) expression. Fluorescent-labeled tissue slides were imaged on a quantitative pathology scope with various zoom levels allowing for qualitative and quantitative interpretation. Tissue from four COVID- 19 positive autopsy cases and a live seroconverted patient was imaged with transmission electron microscopy (TEM). Results: H&E histomorphology showed three of the six COVID-19 biopsies had normal spermatogenesis while the remaining three had impaired spermatogenesis. TEM showed the COVID-19 virus in testis tissue of one COVID-19 positive autopsy case and the live biopsy, H&E stain on the same autopsy case demonstrated interstitial macrophage and leukocyte infiltration. Immunofluorescent stained slides from six COVID-19 positive men demonstrated a direct association between increased quantitative ACE-2 levels and impairment of spermatogenesis. Conclusions: The novel COVID-19 has an affinity for ACE-2 receptors. Since ACE-2 receptor expression is high in the testes, we hypothesized that COVID-19 is prevalent in testes tissue of infected patients. This study suggests the male reproductive tract, specifically the testes, may be targets of COVID-19 infection. We found an inverse association between ACE-2 receptor levels and spermatogenesis, suggesting a possible mechanism of how COVID-19 can cause infertility.

Biological Screening of Novel Derivatives of Valproic Acid for Anticancer and Antiangiogenic Properties

Farooq, Muhammad,El-Faham, Ayman,Khattab, Sherine N.,Elkayal, Ahmed M.,Ibrahim, Mahmoud F.,Taha, Nael Abu,Baabbad, Almohannad,Wadaan, Mohammad A.M.,Hamed, Ezaat A. Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18

Background: Valproic acid (VPA) is a potent anticancer and antiangiogenic agent. However, design and synthesis of chemical derivatives with improved antiangiogenic and anticancer activities are still necessary. In this study a library of novel derivatives of VPA was synthesized and tested. Methods: A human liver cancer cell line (HepG2) and a human normal embryonic kidney cell line (HEK 293) were exposed to various concentrations of VPA derivatives for 24 hours and cell viability was checked by MTT colorimetric assay. Anti-angiogenic properties were evaluated in transgenic zebrafish embryos. Results: N-valproylglycine derivatives suppressed survival almost 70% (p value 0.001) in HepG2 cells but only 10-12% in HEK 293 cells (p value 0.133). They also suppressed angiogenic blood vessel formation by 80% when used between $2-20{\mu}M$ in zebrafish embryos. Valproic acid hydrazides showed moderate level of anticancer activity by affecting 30-50% (p value 0.001) of cell viability in HepG2 cells and 8-10% in HEK293 cells (p value 0.034). Conclusion: The majority of compounds in this study showed potent and stronger antiangiogenic and anticancer activity than VPA. They proved selectively toxic to cancer cells and safer for normal cells. Moreover, these compounds inhibited developmental angiogenesis in zebrafish embryos. Based on the fact that liver is a highly vascularized organ, in case of liver carcinoma these compounds have the potential to target the pathological angiogenesis and could be an effective strategy to treat hepatocellular carcinoma.

Analysis of Responses to Kava Kava in the Feline Pulmonary Vascular Bed

Alan D. Kaye,Jason M. Hoover,Ikhlass N. Ibrahim,Aaron M. Fields,Todd A. Richards 한국식품영양과학회 2006 Journal of medicinal food Vol.9 No.1

This study was designed to test the hypothesis that kava kava induces a depressor response in the pulmonaryvascular bed of the cat and to identify the pathways involved in the mediation or modulation of these effects. In separate ex-periments, the effects of L-N5-(1-iminoethyl)ornithine hydrochloride (L-NIO), a nitric oxide synthase inhibitor, glibenclamide,an ATP-sensitive K. channel blocker, meclofenamate, a nonselective cyclooxygenase inhibitor, nicardipine, a calcium chan-nel blocker, bicuculline, a .-aminobutyric acid (GABA)A receptor antagonist, and saclofen, a GABAB antagonist, were in-vestigated on pulmonary arterial responses to kava kava (kava), pinacidil, an ATP-sensitive K. channel activator, bradykinin,an inducer of nitric oxide synthase, 3-aminopropyl(methyl)phosphinic acid hydrochloride (SKF-97541), a GABAB receptoragonist, and muscimol, a GABAA receptor agonist. Lobar arterial perfusion pressure and systemic pressure were continuouslymonitored, electronically averaged, and recorded. Under elevated tone conditions in the isolated left lower lobe of the felinevascular bed, kava induced a dose-dependent vasodepressor response that was not significantly altered after administration ofL-NIO, glibenclamide, meclofenamate, or saclofen. Responses to kava were significantly reduced after administration of ei-ther nicardipine or bicuculline. When the calcium channel blocker nicardipine was administered in addition to the GABAblocker bicuculline, there was near complete attenuation of the kava-induced vasodepressor responses. The results of this in-vestigation suggest that kava has potent vasodepressor activity in the feline lung bed and that this response is mediated ormodulated by both a calcium channel- and GABA receptor-sensitive pathway.

Activity and stability of purified amylase produced by streptomyces aureofaciens 77

Ibrahim, A.N.,Ahmed, F.H.,Ibrahim, M.M.K.,Arafa, M.A.I. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.1

The effects of pH values, temperature and some elements on the amylolytic activity and stability of the purified S. aureofacienc 77 amylase were studied in this investigation. The purified enzyme showed its maximum activity at pH 6 within 8 min incubation at $40^{\circ}C$. None of the tested 6 metals showed on stimulatory effect on the enzymatic activity, $Fe^{+++}$, $Cu^{++}$ and $Hg^{++}$ at high dose inhibited the enzyme activity to great extent as compared with $Zn^{++}$, $Mn^{++}$ and $Fe^{++}$ whih gave less effect in this respect. The enzyme liquor was found to be thermolabile, since it lost completely its activity after 4 days incubation under room temperature and showed maximum activity during this period as a result of additions of $Ca^{++}$and NaCl, Gradual reduction was however recorded until activity reached 30% after 60 days of incubation.

Precepitation and purification of amylase enzyme produced by streptomyces aureofaciens 77

Ibrahim, A.N.,Ahmed, F.H.,Ibrahim, M.M.K.,Arafa, M.A.I. The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.1

Precipitation and purification of amylase secreted by Streptomyces aureofaciens 77 in liquid inorganic salts-starch medium under the optimum conditions were carried out. Ammonium sulphate fractionation was used to precipitate amylase in cell free culture filtrate. (NH/sub 4/)/sub 2/ SO/sub 4/ at a concentration of 50-70% saturation gave the highest enzyme yield. The obtained precipitates were redissolved in phosphate buffer (pH 7.0) and subjected to dialysis. The dialyzed enzyme preparation was applied to DEAE-cellulose column chromatography which resulted in an increase of purification up to 59.48 fold. A further step of purification was done by applying the obtained purified sample to Sephadex-G200 column chromatography which resulted in ann increase of purification up to 73. 92 fold. The results clearly indicated that the isolated amylase from S. aureofaciens 77 was only on type.

METHODS TO IMPROVE UTILIZATION OF RICE STRAW II. EFFECTS OF DIFFERENT LEVELS OF FEEDING ON INTAKE AND DIGESTIBILITY OF UNTREATED AND UREA AMMONIA TREATED RICE STRAW

Badurdeen, A.L.,Ibrahim, M.N.M.,Schiere, J.B. Asian Australasian Association of Animal Productio 1994 Animal Bioscience Vol.7 No.2

Forty cross bred ($168\;{\pm}\;28\;kg$) bull calves were offered either untreated (US) or urea ammonia treated (TS) rice straw at five levels of feeding, namely; 60, 80, 100, 120 140% of ad libitum. Ad libitum level for each animal was estimated over a period of one month, which was followed by a preliminary period of 21 days and a collection period of 15 days. The maximum organic matter intake (OMI-kg/100 kg BW) were 2.08 and 3.35 for US and TS, respectively and urea treatment increased the maximum OMI by 61% than for US. In order to reach maximum intake the amount feed refusal should be 25% for US, but with TS maximum intake was not reached even when the amount of feed refused was 39% of that consumed. The OMD of US significantly decreased with increase in OMI, whereas with TS the decrease was not significant. The inability of animals to select between stems and leaves particularly in TS might be one of the reasons for its constant digestibility. Considering the substantial increases in intake and the negative effect on digestibility of US, further trials are warranted, as well as studies to determine the practical implications.

Effect of Xylitol on Remineralization of Demineralized Dental Enamel

e Ibrahim-Auerkari, A soufyan, F Alkatiri, F Verisqa, A Megantoro, n Sumawinata, S Mangundjaja 대한임상예방치과학회 2010 International Journal of Clinical Preventive Denti Vol.6 No.1

Objective: Dental decay by caries only occurs when demineralization is not compensated by a sufficient remineralization process. This investigation aimed to determine in vitro the effects of xylitol exposure on the remineralization as reflected in structure, composition and hardness of demineralized enamel. Materials and Method: Human enamel samples were demineralized for two days at 50 C in a 0.01 M acetate buffer solution (pH 4.0) and then immersed for two weeks at 37°C in a remineralizing solution containing 20% or 50% xylitol. Surface microstructure, composition and hardness levels were measured of the enamel samples with and without xylitol treatment. Results: The results showed significantly higher mean enamel hardness after immersion in the xylitol-containing remineralization solution in comparison with the demineralized samples (p<0.05). However, no significant difference was observed in the mean hardness of the groups treated with 20% or 50% xylitol. Conclusion: This could be taken to suggest that high xylitol concentrations in the remineralizing solution are not necessary to significantly improve the surface structure and strength of demineralized enamel.

Effect of Xylitol on Remineralization of Demineralized Dental Enamel

E Ibrahim-Auerkari,A Soufyan,F Alkatiri,F Verisqa,A Megantoro,N Sumawinata,S Mangundjaja 대한예방치과학회 2010 International Journal of Clinical Preventive Denti Vol.6 No.2

Objective: Dental decay by caries only occurs when demineralization is not compensated by a sufficient remineralization process. This investigation aimed to determine in vitro the effects of xylitol exposure on the remineralization as reflected in structure, composition and hardness of demineralized enamel. Materials and Method: Human enamel samples were demineralized for two days at 50 C in a 0.01 M acetate buffer solution (pH 4.0) and then immersed for two weeks at 37°C in a remineralizing solution containing 20% or 50% xylitol. Surface microstructure, composition and hardness levels were measured of the enamel samples with and without xylitol treatment. Results: The results showed significantly higher mean enamel hardness after immersion in the xylitol-containing remineralization solution in comparison with the demineralized samples (p<0.05). However, no significant difference was observed in the mean hardness of the groups treated with 20% or 50% xylitol. Conclusion: This could be taken to suggest that high xylitol concentrations in the remineralizing solution are not necessary to significantly improve the surface structure and strength of demineralized enamel.

Behavior of reinforced concrete segmental hollow core slabs under monotonic and repeated loadings

Najm, Ibrahim N.,Daud, Raid A.,Al-Azzawi, Adel A. Techno-Press 2019 Structural monitoring and maintenance Vol.6 No.4

This study investigated experimentally the response of thick reinforced concrete specimens having hollow cores with critical parameters. The investigation includes testing of twelve specimens that are solid and hollow-core slab models. Each specimen consists of two pieces, the piece dimensions are (1.2 m) length, (0.3 m) width and (20 cm) thickness tested under both monotonic and repeated loading. The test program is carried out to study the effects of load type, core diameters, core shape, number of cores, and steel fiber existence. Load versus deflection at mid span, failure modes, and crack patterns were obtained during the test. The test results showed that core shape and core number has remarkable influenced on cracking pattern, ultimate load, and failure mode. Also, when considering repeated loading protocol, the ultimate load capacity, load at yielding, and ductility is reduced.