Synthesis, Structural Characterization, and Antimicrobial Activities of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) Complexes of Triazole‐based Azodyes

Khedr, Abdalla M.,Gaber, Mohamed,Abd El‐,Zaher, Eman H. SCIENCE PRESS 2011 CHINESE JOURNAL OF CHEMISTRY Vol.29 No.6

<P><B>Abstract</B></P><P>The synthesis and characterization of new transition metal complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with 3‐(2‐hydroxynaph‐1‐ylazo)‐1,2,4‐triazole (<B>HL<SUP>1</SUP></B>) and 3‐(2‐hydroxy‐3‐carboxynaph‐1‐ylazo)‐1,2,4‐triazole (<B>HL<SUP>2</SUP></B>) have been carried out. Their structures were confirmed by elemental analyses, thermal analyses, spectral and magnetic data. The IR and <SUP>1</SUP>H NMR spectra indicated that <B>HL<SUP>1</SUP></B> and <B>HL<SUP>2</SUP></B> coordinated to the metal ions as bidentate monobasic ligands via the hydroxyl O and azo N atoms. The UV‐Vis, ESR spectra and magnetic moment data revealed the formation of octahedral complexes [Mn<B>L<SUP>1</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>3</SUB>] (<B>1</B>), [Co<B>L<SUP>1</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>3</SUB>]·H<SUB>2</SUB>O (<B>2</B>), [Mn<B>L<SUP>2</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>3</SUB>] (<B>6</B>) and [Co<B>L<SUP>2</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>3</SUB>] (<B>7</B>), [Ni<B>L<SUP>1</SUP></B>(AcO)(H<SUB>2</SUB>O)] (<B>3</B>), [Zn<B>L<SUP>1</SUP></B>(AcO)(H<SUB>2</SUB>O)]·H<SUB>2</SUB>O (<B>5</B>), [Ni<B>L<SUP>2</SUP></B>(AcO)(H<SUB>2</SUB>O)] (<B>8</B>), [Zn<B>L<SUP>2</SUP></B>(AcO)(H<SUB>2</SUB>O)]·10H<SUB>2</SUB>O (<B>10</B>) have tetrahedral geometry, whereas [Cu<B>L<SUP>1</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>2</SUB>] (<B>4</B>) and [Cu<B>L<SUP>2</SUP></B>(AcO)(H<SUB>2</SUB>O)<SUB>2</SUB>]·5H<SUB>2</SUB>O (<B>9</B>) have square pyramidal geometry.. The mass spectra of the complexes under EI‐con‐ ditions showed the highest peaks corresponding to their molecular weights, based on the atomic weights of <SUP>55</SUP>Mn, <SUP>59</SUP>Co, <SUP>58</SUP>Ni, <SUP>63</SUP>Cu and <SUP>64</SUP>Zn isotopes; besides, other peaks containing other isotopes distribution of the metal. Kinetic and thermodynamic parameters of the thermal decomposition stages were computed from the thermal data using Coats‐Redfern method. <B>HL<SUP>2</SUP></B> and complexes <B>6</B>–<B>10</B> were found to have moderate antimicrobial activities against <I>Staphylococcus aureus </I>(gram positive), <I>Escherichia coli </I>(gram negative) and <I>Salmonella </I>sp bacteria, and antifungal activity against <I>Fusarium oxysporum</I>, <I>Aspergillus niger</I> and <I>Candida albicans</I>. Also, in most cases, metallation increased the activity compared with the free ligand.</P>

Adaptive Mitigation of Narrowband Interference in Impulse Radio UWB Systems Using Time-Hopping Sequence Design

Mohamed E. Khedr,Amr El-Helw,Mohamed Hossam Afifi 한국통신학회 2015 Journal of communications and networks Vol.17 No.6

The coexistence among different systems is a major problem in communications. Mutual interference between different systems should be analyzed and mitigated before their deployment. The paper focuses on two aspects that have an impact on the system performance. First, the coexistence analysis, i.e. evaluating the mutual interference. Second aspect is the coexistence techniques, i.e. appropriate system modifications that guarantee the simultaneous use of the spectrum by different technologies. In particular, the coexistence problem is analyzed between ultra-wide bandwidth (UWB) and narrow bandwidth (NB) systems emphasizing the role of spectrum sensing to identify and classify the NB interferers that mostly affect the performance of UWB system. A direct sequence (DS)-time hopping (TH) code design technique is used to mitigate the identified NB interference. Due to the severe effect of Narrowband Interference on UWB communications, we propose an UWB transceiver that utilizes spectrum-sensing techniques together with mitigation techniques. The proposed transceiver improves both the UWB and NB systems performance by adaptively reducing the mutual interference. Detection and avoidance method is used where spectrum is sensed every time duration to detect the NB interferer's frequency location and power avoiding it's effect by using the appropriate mitigation technique. Two scenarios are presented to identify, classify, and mitigate NB interferers.

Separation axioms in generalized fuzzy soft topological spaces

F. H. Khedr,M. S. Malfi 원광대학교 기초자연과학연구소 2019 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.18 No.2

In the present paper, we continue the study on generalized fuzzy soft topological spaces. We introduce the notion of separation axioms $ T_i $ ($ i = 0, 1, 2, 3, 4 $) in generalized fuzzy soft topological spaces and study some of its properties. By using this notions, we also give some basic theorems of separation axioms in generalized fuzzy soft topological spaces. Finally, we discuss hereditary property and topological property in generalized fuzzy soft topological spaces.

New ursane triterpenoids from Ficus pandurata and their binding affinity for human cannabinoid and opioid receptors

Amgad I. M. Khedr,Sabrin R. M. Ibrahim,Gamal A. Mohamed,Hany E. A. Ahmed,Amany S. Ahmad,Mahmoud A. Ramadan,Atef E. Abd El-Baky,Koji Yamada,Samir A. Ross 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.7

Phytochemical investigation of Ficus pandurataHance (Moraceae) fruits has led to the isolation of two newtriterpenoids, ficupanduratin A [1b-hydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (11) and ficupanduratin B [21ahydroxy-3b-acetoxy-11a-methoxy-urs-12-ene] (17), alongwith 20 known compounds: a-amyrin acetate (1), a-amyrin(2), 3b-acetoxy-20-taraxasten-22-one (3), 3b-acetoxy-11amethoxy-olean-12-ene (4), 3b-acetoxy-11a-methoxy-12-ursene (5), 11-oxo-a-amyrin acetate (6), 11-oxo-b-amyrinacetate (7), palmitic acid (8), stigmast-4,22-diene-3,6-dione(9), stigmast-4-ene-3,6-dione (10), stigmasterol (12), b-sitosterol(13), stigmast-22-ene-3,6-dione (14), stigmastane-3,6-dione (15), 3b,21b-dihydroxy-11a-methoxy-olean-12-ene (16), 3b-hydroxy-11a-methoxyurs-12-ene (18), 6-hydroxystigmast-4,22-diene-3-one (19), 6-hydroxystigmast-4-ene-3-one (20), 11a,21a-dihydroxy-3b-acetoxy-urs-12-ene(21), and b-sitosterol-3-O-b-D-glucopyranoside (22). Compound21 is reported for the first time from a natural source. The structures of the 20 compounds were elucidated on thebasis of IR, 1D (1H and 13C), 2D (1H–1H COSY, HSQC,HMBC and NOESY) NMR and MS spectroscopic data, inaddition to comparison with literature data. The isolatedcompounds were evaluated for their anti-microbial, antimalarial,anti-leishmanial, and cytotoxic activities. In addition,their radioligand displacement affinity on opioid andcannabinoid receptors was assessed. Compounds 4, 11, and15 exhibited good affinity towards the CB2 receptor, withdisplacement values of 69.7, 62.5 and 86.5 %, respectively. Furthermore, the binding mode of the active compounds inthe active site of the CB2 cannabinoid receptors was investigatedthrough molecular modelling.

Metronomic capecitabine versus doxorubicin in advanced hepatocellular carcinoma

Gehan Abd Elatti Khedr,Sherif Farouk Elzawawy,Ahmad Gaber Gowil,Amany Saleh Elyamany,Mohamed Eshafei 대한종양외과학회 2016 Korean Journal of Clinical Oncology Vol.12 No.1

Purpose: We evaluated oral metronomic capecitabine (MC) compared to intravenous doxorubicin in patients with advanced or metastatic hepatocellular carcinoma (HCC). Methods: From January 2013 to December 2015, patients with Child-Pugh class A or early B were randomized either to MC group (500 mg twice daily continuously) or doxorubicin group (60 mg∕m2 every 21 days). Results: Forty patients were included in each group. The baseline clinical characteristics of the enrolled patients were well balanced between the two groups. No complete response (CR) was reported in either group. In MC group, 2 patients (5%) had partial response (PR), 25 patients (62.5%) stable disease (SD) and 27 patients (67.5%) had disease control. In doxorubicin group, 4 patients (10%) achieved PR, 24 patients (60%) SD and 28 patients (70%) had disease control. The 6 months overall survival (OS) was 77.5% for MC and 75% for doxorubicin. The one year OS was 47.5% for MC and 42.5% for doxorubicin (P=0.521). The median OS survival was 10.2 months for MC and 9.6 months for doxorubicin (95% confidence interval, 3.2–6.5). The 6 month progression-free survival (PFS) was 45% for MC and 50% for doxorubicin. The one year PFS was 12.5% for MC and 7.5% for doxorubicin (P=0.289). The median time to progression was 3.4 months for MC and 3.1 months for doxorubicin. On multivariate analysis no significant impact for tumor stage, previous transhepatic arterial chemoembolization, portal vein thrombosis or median baseline alpha fetoprotein on OS. Conclusion: MC showed response rate and survival outcome comparable to doxorubicin in advanced HCC but with a more favorable toxicity profile.

Retroperitoneal Extrapleural Approach for Corpectomy of the First Lumbar Vertebra : Technique and Outcome

Zidan, Ihab,Khedr, Wael,Fayed, Ahmed Abdelaziz,Farhoud, Ahmed The Korean Neurosurgical Society 2019 Journal of Korean neurosurgical society Vol.62 No.1

Objective : Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy. Methods : Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months. Results : The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected. Conclusion : The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior loadbearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

Highly efficient and reusable superhydrophobic/superoleophilic polystyrene@ Fe₃O₄ nanofiber membrane for high-performance oil/water separation

Moatmed, Sara M.,Khedr, Mohamed Hamdy,El-dek, S.I.,Kim, Hak-Yong,El-Deen, Ahmed G. Elsevier 2019 Journal of environmental chemical engineering Vol.7 No.6

<P><B>Abstract</B></P> <P>Due to increasing of oil spills and high organic contamination of marine environment, developing of cost-effective and rapid oil/water separation technique has become inevitable. Herein, freestanding and flexible hybrid polystyrene nanofibers are introduced as highly efficient hybrid membrane for ultrafast oil/water separation without external pressure. Typically, different loading of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles embedded into polystyrene nanofibers using electrospinning to fabricate superhydrophobic/super-oleophilic membrane. The morphological shape, crystal structure and surface wettability behavior were elucidated by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and contact angel, respectively. The optimum loading of magnetite nanoparticles into the nanofiber membranes was investigated to achieve best separation performance. The obtained results demonstrated that the incorporation of (Fe<SUB>3</SUB>O<SUB>4</SUB>) nanoparticles into membrane has a significant impact for enhancing superhydrophobic properties and the separation efficiency against light and heavy oils. Among all formulations, the fabricated (PS@Fe<SUB>3</SUB>O<SUB>4</SUB>10 wt.%) membrane revealed ultrahigh flux (5000 L m<SUP>−2</SUP> h<SUP>−1</SUP>) with separation efficiency of 99.8 % for hexane under gravity driven process and excellent superhydrophobicity with water contact angle 162° moreover excellent reusability 98.5 % for 50 consecutive cycles. Interestingly, the proposed hybrid nanofiber membrane achieved distinct separation efficiencies 95 % and 92 % for food oils such as olive oil and sesame oil. Overall, the current study provides cost-effective and facile approach to distinctly improve the membrane performance for durable oil/water separation technique.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Maintenance metronomic chemotherapy combined with conventional treatment for metastatic breast cancer patients

Sherif Elzawawy,Gehan Khedr,Basma Elsabaa 대한종양외과학회 2015 Korean Journal of Clinical Oncology Vol.11 No.2

Purpose: To evaluate the progression free survival, response rate and toxicity for patients who were treated with conventional therapy combined with metronomic chemotherapy. Methods: patients received either chemotherapy followed by maintenance metronomic chemotherapy with or without hormonal therapy or primarily treated with hormonal therapy concomitant with metronomic chemotherapy. Metronomic chemotherapy consists of cyclophosphamide 50 mg tablet daily and methotrexate 2.5 mg twice daily on days 2 and 5 weekly, continued until disease progression or development of unacceptable toxicity. Results: after median follow up of 18 months, 40 patients were assessed. The progression free survival was 52.5% and the median time to disease progression was 10.4 months. The overall clinical benefit (complete response [CR]+partial remission [PR]+stable disease [SD]) was 52.5 % with no G3 or G4 toxicities encountered for metronomic therapy. The median time to disease progression was 12.5 months for estrogen receptor (ER)+ve, human epidermal growth factor receptor 2 (Her2)–ve (progression free survival [PFS]: 67.5%) compared to 8 months for ER+ve, Her2+ve (PFS: 10%), 9 months for ER–ve, Her2+ve (PFS: 10%) and 8 months for triple negative (PFS: 12.5%). The difference was statistically significant (P=0.018). Conclusion: maintenance metronomic cyclophosphamide and methotrexate demonstrated efficacy and provided durable disease stabilization especially for ER positive patients. The low costs and minimal toxicity allow patients to continue treatment for several months and support its use as an additional therapeutic tool.

S-CLOSEDNESS IN BITOPOLOGICAL SPACES

Mashhour, A.S.,Khedr, F.H.,Hasanein, I.A.,Allam, A.A. Department of Mathematics 1984 Kyungpook mathematical journal Vol.24 No.1

Effect of earthquake induced-pounding on the response of four adjacent buildings in series

Hytham Elwardany,Beshoy Mosa,M. Diaa Eldin Khedr,Ayman Seleemah 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.2

Structural pounding due to strong seismic excitations can result in severe damage or even collapse of colliding structures. Many researchers focused on studying the mutual pounding between two adjacent structures while very few researches were concerned with the pounding of a series of structures. This paper aims to study the pounding effect on a series of four buildings having different natural frequencies. The paper also investigates the effect of different arrangements of the four buildings on their pounding response. For this, a mathematical model was constructed using Matlab code where, pounding was modeled using a contact force-based approach. A Non-Linear viscoelastic (Hertzdamp) contact element was used and activated only during the approach period of collision. The mathematical model was validated by comparing its prediction versus experimental results on three adjacent buildings. Then the model was used to study the pounding between four adjacent structures arranged in different sequences according to their natural frequencies. The results revealed that increasing the gap distance generally led to decrease the peak responses of the towers. Such response is somehow different from that predicted earlier by the authors for the case of three adjacent buildings. Moreover, the arrangement of towers has a significant effect on their pounding response. Significant difference between the natural frequencies of adjacent structures increases the pounding forces especially when the more flexible buildings are located at the outer edge of the series. The study points out the need for further researches on buildings in series to gain a better understanding of such complex phenomena.