Synthesis,Antiviral, and Antimicrobial Activity of N‐ and S‐Alkylated Phthalazine Derivatives

A series of N‐alkylphthalazinone were synthesized by the reaction of phthalazin‐1(2H)‐one derivatives 1a , 1b , 1c with alkylating agents namely, propargyl, allyl bromide, epichlorohydrin, 1,3‐dichloro‐2‐propanol, 4‐bromobutylacetate, and 1‐(bromomethoxy)ethyl acetate to give the corresponding N‐alkylphthalazinone 2a , 2b , 2c , 3a , 3b , 3c , 5a , 5b , 5c , 6a , 6b , 6c , 7a , 7b , 7c , and 9a , 9b , 9c . Alkylation of phthalazin‐1(2H)‐thione to give a series from S‐alkylphthalazine 12 , 13 , 14 and thioglycosides 15 and 17 was performed. Deprotection of compounds 7a , 7b , 7c , 9a , 9b , 9c , 15 , and 17 resulted in the formation of the corresponding products 8a , 8b , 8c , 10a , 10b , 10c , 16 , and 18 . The structure of newly synthesized compounds was assigned by IR, ¹H, ¹³C NMR, and elemental analysis. Some of these compounds were screened for antiviral and antimicrobial activity.     

以脉冲萃取柱利用三异辛胺从高浓度铀溶液中回收铀

利用三异辛胺(TOA)纯化Gattar小型试验工厂的高浓度铀溶液(洗脱液的铀浓度7 g·L^-1),研究了脉冲萃取柱的性能。利用实验室级脉冲萃取柱进行了实验室规模的溶剂萃取实验和后续实验。结果表明,在室温、pH=1和有机相与水相的比例(V_O/V_A)约为1.8：1时,加入二(2-乙基己基)磷酸(D2EHPA)使其与TOA的比例(V_D2EHPA/V_TOA)为2：3,可使萃取克服Cl-的抑制效应,提高效率。将结论用于考察试验工厂级萃取柱的流体力学和传质性能,结果表明用脉冲萃取柱萃取铀可以达到97%的萃取效率,具有可行性。     

Sandwich Complex‐Containing Macromolecules: Property Tunability Through Versatile Synthesis

Sandwich complexes feature unique properties as the physical and electronic properties of a hydrocarbon ligand or its derivative are integrated into the physical, electronic, magnetic, and optical properties of a metal. Incorporation of these complexes into macromolecules results in intriguing physical, electrical, and optical properties that were hitherto unknown in organic‐based macromolecules. These properties are tunable through well‐designed synthetic strategies. This review surveys many of the synthetic approaches that have resulted in tuning the properties of sandwich complex‐containing macromolecules. While the past two decades have seen an ever‐growing number of research publications in this field, gaps remain to be filled. Thus, we expect this review to stimulate research interest towards bridging these gaps, which include the insolubility of some of these macromolecules as well as expanding the scope of the sandwich complexes.

     

Priority-based parameter optimization strategy for reducing the effects of four-wave mixing on WDM system

In order to meet the ultra high speed and ultra long-haul transmission distance in wavelength division multiplexing (WDM) systems, the nonlinear impairment affecting the overall spectral efficiency and system performance should be minimized. This paper proposes a strategy to mitigate the four-wave mixing (FWM) effect in WDM system. The strategy determines the effect of both single and combined effects of second, third, and fourth optimization priority parameters such as fiber length, input power, dispersion, channel spacing, and effective area on FWM power. A comparison study was made under different types of optical fiber such as single-mode fiber (SMF), dispersion shifted fiber, non-zero dispersion fiber, and non-zero dispersion shifted fiber. In addition, the system performance in term of bit-error-rate was calculated in the case of single priority (impact of effective area) and combined priority (impact of effective area, input power, fiber length and channel spacing). The results show that the FWM effect was reduced based on the transmission parameters order of optimization, i.e., priority selection proposed. Moreover, the results indicated that increasing sequentially the effective area, fiber length; channel spacing and decreasing the input power provide the most significant sequence in suppressing the effects of FWM. This priority sequence brought the suppression ratio to approximately 26.3% in SMF, which suppressed the FWM effects up to −50 dBm. In term of BER; the combined priority introduces improvement in BER of 2.31 × 10⁻²⁵ in comparison with single priority that has value of BER 4 × 10⁻¹⁴. Finally, this work suggests that the proposed priority-based parameter optimization strategy is an ideal solution for optimum performance of WDM system.     

Growth of Fe-doped ZnO nanorods using aerosol-assisted chemical vapour deposition via in situ doping

In situ Fe doping of ZnO nanorods (NRs) was performed using aerosol assisted chemical vapour deposition (AA-CVD) technique. As the aerosol generator is located outside the reactor, AA-CVD provides the flexibility to control doping parameters, such as doping timing, doping duration and a wider choice of dopant precursors. The Fe dopant aerosol was flowed into the reactor during the growth of ZnO NRs to achieve in situ doping. The X-ray diffraction analysis indicates that the Fe dopants were introduced into the ZnO lattice and present mainly in the form of Fe²⁺. This result is supported by the X-ray photoelectron spectroscopy analysis as the doublet separation is 13.6 eV, although there is a shift of Fe_1/2 and Fe_3/2 peaks to a lower binding energy levels. A strong green emission of PL of Fe-doped ZnO NRs shows that the NRs have poor crystal quality attributed to the Fe-induced defects (recombination centres). The poor photocatalytic performance in degrading Rhodamine B solution of Fe-doped ZnO NRs further proves that the Fe-induced defects were recombination centres rather than traps. Lastly, the growth mechanism of in situ Fe doping of ZnO NRs was discussed.     

A review on the synthesis of heteroannulated quinolones and their biological activities

Molecular Diversity - The quinoline scaffold has become an important construction motif for the development of new drugs. The quinolones and their heteroannulated derivatives have high importance...     

A Suitable Active Control for Suppression the Vibrations of a Cantilever Beam

In our consideration, a comparison between four different types of controllers for suppression the vibrations of the cantilever beam excited by an external force is carried out. Those four types are the linear velocity feedback control, the cubic velocity feedback control, the non-linear saturation controller (NSC) and the positive position feedback (PPF) controller. The suitable type is the PPF controller for suppression the vibrations of the cantilever beam. The approximate solution obtained up to the first approximation by using the multiple scale method. The PPF controller effectiveness is studied on the system. We used frequency-response equations to investigate the stability of a cantilever beam. We notified that, there is a good agreement between the analytical solution and the numerical solution.     

Preparation and characterization of Ni(II)/polyacrylonitrile and carbon nanotube composite modified electrode and application for carbohydrates electrocatalytic oxidation

A nickel(II) into porous polyacrylonitrile–carbon nanotubes composite modified glassy carbon electrode (Ni/PAN-CNT/GCE) was fabricated by simple drop-casting and immersing technique. The unique electrochemical activity of Ni/PAN-CNT composite modified glassy carbon electrode was illustrated in 0.10?M NaOH using cyclic voltammetry. The Ni/PAN-CNT/GCE exhibits the characteristic of improved reversibility and enhanced current responses of the Ni(III)/Ni(II) couple compared with Ni/PAN/GCE and Ni/CNT/GCE. The results of electrochemical impedance spectroscopy and scanning electron microscopy indicated the successful immobilization for PAN-CNT composite film. Kinetic parameters such as the electron transfer coefficient, α, and rate constant, k _s, of the electrode reaction were determined. Ni/PAN-CNT/GCE also shows good electrocatalytic activity toward the oxidation of carbohydrates (glucose, sucrose, fructose, and sorbitol). The electrocatalytic response showed a wide linear range (10–1,500, 12–3,200, 7–3,500, and 16–4,200?μM for glucose, sucrose, fructose, and sorbitol, respectively) as well as its experimental limit of detection can be achieved 6, 7, 5, and 11?μM for glucose, sucrose, fructose, and sorbitol, respectively. The modified electrode for carbohydrates determination is of the property of simple preparation, good stability, and high sensitivity.     

Fluorescence and Electrochemical Sensing of Pesticides Methomyl, Aldicarb and Prometryne by the Luminescent Europium-3-Carboxycoumarin Probe

This work describes the application of time resolved fluorescence in microtiterplates and electrochemical methods on glassy carbon electrode for investigating the interactions of europium-3-carboxycoumarin with pesticides aldicarb, methomyl and prometryne. Stern-volmer studies at different temperatures indicate that static quenching dominates for methomyl, aldicarb and prometryne. By using Lineweaver-Burk equation binding constants were determined at 303 K, 308 K and 313 K. A thermodynamic analysis showed that the reaction is spontaneous with ΔG being negative. The enthalpy ΔH and the entropy ΔS of reactions were all determined. A time-resolved (gated) luminescence-based method for determination of pesticides in microtiterplate format using the long-lived europium-3-carboxycoumarin has been developed. The limit of detection is 4.80, 5.06 and 8.01 μmol L⁻¹ for methomyl, prometryne and aldicarb, respectively. This is the lowest limit of detection achieved so far for luminescent lanthanide-based probes for pesticides. The interaction of the probe with the pesticides has been investigated using cyclic voltammetry (CV), differential pulse polarography (DPP), square wave voltammetry (SWV) and linear sweep voltammetry (LSV) on a glassy carbon electrode in I = 0.1 mol L⁻¹ p-toluenesulfonate at 25 °C. The diffusion coefficients of the reduced species are calculated. The main properties of the electrode reaction occurring in a finite diffusion space are the quasireversible maximum and the splitting of the net SWV peak for Eu(III) ions in the ternary complex formed . It was observed that the increase of the cathodic peak currents using LSV is linear with the increase of pesticides concentration in the range 5 × 10⁻⁷ to 1 × 10⁻⁵ mol L⁻¹. The detection limit (DL) were about 1.01, 2.23 and 1.89 μmolL⁻¹ for aldicarb, methomyl and prometryne, respectively. In order to assess the analytical applicability of the method, the influence of various potentially interfering species was examined. Influence of interfering species on the recovery of 10 μmol L⁻¹ pesticides has been investigated.     

Antihypertensive drugs as an inhibitors for corrosion of aluminum and aluminum silicon alloys in aqueous solutions

The corrosion behavior of aluminum and three aluminum–silicon alloys in different concentrations of HCl solutions and its inhibition by antihypertensive drugs was studied using potentiostatic polarization measurements. As the acid concentration increases, the rate of corrosion increases. Aluminum is less susceptible to corrosion than any of Al–Si alloys. The inhibition efficiency of the drug compounds increases with their concentration up to a critical value. At higher additive concentrations the inhibition efficiency starts to decrease. The inhibitive action of these compounds is due to their formation of insoluble complex adsorbed on the metal surface. The adsorption follows Langmuir adsorption isotherms. It was found that the drugs compounds provide protection to Al and Al–Si alloys against pitting corrosion by shifting the pitting potential to more positive direction until critical drug concentrations (250 ppm). After this critical concentration the inhibition against to pitting corrosion starts to decrease.