A Bioactive Fraction from Streptomyces sp. Enhances Maize Tolerance against Drought Stress

Warrad Mona,Hassan Yasser M.,Mohamed Mahmoud S.M,Hagagy Nashwa,Al-Maghrabi Omar A,Selim Samy,Saleh Ahmed M.,AbdElgawad Hamada 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

Drought stress is threatening the growth and productivity of many economical crops. Therefore, it is necessary to establish innovative and efficient approaches for improving crop growth and productivity. Here we investigated the potentials of the cell-free extract of Actinobacteria (Ac) isolated from a semi-arid habitat (Al-Jouf region, Saudi Arabia) to recover the reduction in maize growth and improve the physiological stress tolerance induced by drought. Three Ac isolates were screened for production of secondary metabolites, antioxidant and antimicrobial activities. The isolate Ac3 revealed the highest levels of flavonoids, antioxidant and antimicrobial activities in addition to having abilities to produce siderophores and phytohormones. Based on seed germination experiment, the selected bioactive fraction of Ac3 cell-free extract (F2.7, containing mainly isoquercetin), increased the growth and photosynthesis rate under drought stress. Moreover, F2.7 application significantly alleviated drought stress-induced increases in H2O2, lipid peroxidation (MDA) and protein oxidation (protein carbonyls). It also increased total antioxidant power and molecular antioxidant levels (total ascorbate, glutathione and tocopherols). F2.7 improved the primary metabolism of stressed maize plants; for example, it increased in several individuals of soluble carbohydrates, organic acids, amino acids, and fatty acids. Interestingly, to reduce stress impact, F2.7 accumulated some compatible solutes including total soluble sugars, sucrose and proline. Hence, this comprehensive assessment recommends the potentials of actinobacterial cell-free extract as an alternative ecofriendly approach to improve crop growth and quality under water deficit conditions.

Association between GSTP1 Genotypes and Hormone Receptor Phenotype in Invasive Ductal Carcinomas of Breast

Khabaz, Mohamad Nidal,Gari, Mamdooh Abdullah,Al-Maghrabi, Jaudah Ahmed,Nedjadi, Taoufik,Bakarman, Marwan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Eighty six cases of invasive ductal breast carcinomas were utilized to investigate GSTP1 polymorphisms in certain immunohistochemistry (IHC) subtypes of breast cancer with respect to ER, PR and HER2 expression. The frequency of wild allele homozygote, heterozygote and variant allele homozygote genotypes were 46.5%, 52.3% and 1.16% respectively; Whereas 54.3% of the control subjects were GSTP1 wild type allele homozygous, 40.0% were heterozygous and 5.71% mutant allele homozygous. There was dramatic inverted relation between positive IHC ER staining and increasing grade of tumors in general (100%, 88.6%, 40.4%) and especially among tumors with heterozygote genotype of GSTP1 (70%, 35.4%, 22.7). There was increase in positive IHC HER2 staining consistent with higher grades in general (20%, 29.6%, 50.0%), especially among tumors with GSTP1 wild allele homozygote genotype (5.0%, 9.1%, 31.8%). A remarkable reverse relation was also observed between the fraction of IHC hormone receptor phenotype ER+/PR+/ HER2- and increased grade of tumors (60.0%, 45.5%, and 27.3%) especially among tumors with GSTP1 heterozygote genotype, and a similar link was noted regarding ER+/PR-/ HER2- and tumor grade. There was increase in frequency of ER-/PR-/ HER2- (0.0%, 6.8%, and 18.2%) and ER-/PR-/ HER2+ (0.0%, 4.54%, and 40.9%) consistent with the higher grades of tumors in general and especially GSTP1 heterozygote genotype tumors. As a conclusion, there is no correlation between GSTP1 polymorphism and increased risk of breast cancer i.e. the mutant allele is randomly distributed in cancer and control cases. However, there is a link between GSTP1 genotypes and hormone receptor expression status and certain phenotypes of breast cancer, which may have clinical importance.

Cu₀- doped TiO₂ nanofibers as potential photocatalyst and antimicrobial agent

Yousef, A.,El-Halwany, M.M.,Barakat, N.A.M.,Al-Maghrabi, M.N.,Kim, H.Y. Korean Society of Industrial and Engineering Chemi 2015 Journal of industrial and engineering chemistry Vol.26 No.-

Cu<SUB>0</SUB> nanoparticles (NPs)-doped TiO<SUB>2</SUB> nanofibers (NFs) were prepared as an effective photodegradation of three azo dyes as well as an antimicrobial agent under visible light. Fabrication of one dimensional zero-valent Cu nanoparticles-doped TiO<SUB>2</SUB> nanofibers with high aspect ratio have been successfully synthesized by simple and low cost; electrospinning technique followed by hydrothermal process. The photocatalytic activity of introduced nanofibers was evaluated by performing of three azo dyes. Catalytic NFs show a superior photodegaradation activity under visible light as well as good antimicrobial activity. Moreover, photocatalyst nanofibers appeared good stability, which was used for three cycles without regeneration.

Cu0- doped TiO2 nanofibers as potential photocatalyst and antimicrobial agent

Ayman Yousef,M.M. El-Halwany,나지르,Mohammednoor N. Al-Maghrabi,김학용 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.26 No.-

Cu0 nanoparticles (NPs)-doped TiO2 nanofibers (NFs) were prepared as an effective photodegradation of three azo dyes as well as an antimicrobial agent under visible light. Fabrication of one dimensional zero- valent Cu nanoparticles-doped TiO2 nanofibers with high aspect ratio have been successfully synthesized by simple and low cost; electrospinning technique followed by hydrothermal process. The photocatalytic activity of introduced nanofibers was evaluated by performing of three azo dyes. Catalytic NFs show a superior photodegaradation activity under visible light as well as good antimicrobial activity. Moreover, photocatalyst nanofibers appeared good stability, which was used for three cycles without regeneration.

Effects of rapid thermal annealing on the local environment, electronic structure and magnetic properties of Mn doped TiO₂ thin films

Aljawfi, Rezq Naji,Vij, Ankush,Chae, K.H,Dalela, S.,Alvi, P.A.,AL-Maghrabi, M.A.,Kumar, Shalendra Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.445 No.-

<P><B>Abstract</B></P> <P>In this report, nanostructure thin films of Ti<SUB>0.97</SUB> Mn<SUB>0.03</SUB> O<SUB>2−δ</SUB> were deposited on Si (001) substrate by pulsed laser deposition (PLD) technique, followed by rapid thermal annealing (RTA) in different ambient gases; O<SUB>2</SUB>, N<SUB>2</SUB> and Ar. The RTA treatment dramatically affected the surface defects, local environment, electronic structure and magnetic properties of the films, where, annealing of the film in O<SUB>2</SUB> gas recovered the dislocated atoms of oxygen vacancy (Vo) at the surfaces and induced a diamagnetic phase, whereas the annealing of film in N<SUB>2</SUB> gas introduced Vo, reduced the valence state of Ti<SUP>4+</SUP> (TiO<SUB>2</SUB>) into Ti<SUP>3+</SUP> (Ti<SUB>2</SUB>O<SUB>3</SUB>) and induced ferromagnetic (FM) signal. Therefore, the change in the local atomic defects of Vo at the surface texture is likely to be responsible for the magnetic response. The presence of oxygen vacancy has been traced by means of Raman scattering and near edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements. The NEXAFS spectra were carried out in synchrotron facility at Ti/Mn <I>L</I> <SUB>3,2</SUB> and O-<I>K</I> edges. The spectral feature at Ti <I>L</I> <SUB>3,2</SUB> edges revealed the rutile phase of TiO<SUB>2</SUB>. The asymmetry of <I>t</I> <SUB>2</SUB> <I> <SUB>g</SUB> </I> and <I>e<SUB>g</SUB> </I> bands at the O-<I>K</I> edge confirmed the formation of Vo and reflected the modification in the O co-ordination around Ti<SUP>4+</SUP>cations. The Mn <I>L</I> <SUB>3,2</SUB> edges revealed the incorporation of Mn ions in the TiO<SUB>2</SUB> network with Mn<SUP>2+</SUP> and Mn<SUP>3+</SUP> mixed valence states. This different valance states (Mn<SUP>2+</SUP> and Mn<SUP>3+</SUP>) is the basis for the ferromagnetism induced by Stoner spin-splitting of the local density of defects state at Fermi level (E<SUB>F</SUB>). The change in the magnetic moment of the films after RTA process is related to the change in the local density of defects band. Crystal field and charge transfer parameters were extracted roughly by using atomic multiplet calculations (theory).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ti<SUB>0.93</SUB>Mn<SUB>0.03</SUB>O<SUB>2</SUB> thin films were deposited on Si substrate (001) by PLD technique. </LI> <LI> The films have been treated via rapid thermal annealing (RTA) in Ar, N<SUB>2</SUB> and O<SUB>2</SUB>. </LI> <LI> A significant modification is induced by RTA in different ambient gas. </LI> <LI> RTA in O<SUB>2</SUB> decreases the oxygen vacancy (Vo) and optimizes the crystal structure. </LI> <LI> N<SUB>2</SUB> induces the Vo and reduces the valance state of TiO<SUB>2</SUB> (Ti<SUP>4+</SUP>) to be Ti<SUB>2</SUB>O<SUB>3</SUB> (Ti<SUP>3+</SUP>). </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>