(Z)-2-Meth­oxy-N-[(5-nitro­thio­phen-2-yl)methyl­idene]aniline

The dihedral angle between the benzene and thio­phene rings in the title compound, C12H10N2O3S, is 27.94 (13)°. An inter­molecular C—H⋯π inter­action contributes to the stability of the crystal structure

Removal of Heavy Metals from Multicomponent Metal Mixtures by Polymer Enhanced Ultrafiltration: Effects of pH, Ionic Strength and Conformational Changes in Polymer Structure

Fractional separation of industrially important heavy metals (cadmium, nickel, zinc) from binary and ternary metal mixtures by continuous mode polymer enhanced ultrafiltration was studied. Polyethyleneimine (PEI) was used as a complexation polymer. Effects of pH and ionic strength on process efficiency were investigated. To gain insight about the characteristics of binding between highly branched PEI and metal ions and effect of salt concentration on this binding were investigated by performing dynamic and static light scattering measurements. It was observed that with optimum pH and salt concentration, fractional separation of metals can be achieved

Novel boron specific copolymers with quaternary amine segments for efficient boron removal via PEUF

In this study, a copolymer, poly (vinyl amino-N, N'-bis-propane diol-co-DADMAC) (GPVA-co-DADMAC) was synthesized in three comonomer ratios (2%, 5% and 10%) and efficiently exploited for boron removal via polymer enhanced ultrafiltration (PEUF). Boron concentration could be reduced from 10 ppm down to 0.8 ppm by the employment of novel copolymer in continuous PEUF at pH 9 and boron-to-polymer mass ratio (loading) of 0.001. Polymer precipitation was not observed even after complexation with boron. Boron retention was found to be highly pH dependent and boron concentration dependent at constant loading. Hence, efficient polymer regeneration can be expected due to high pH and concentration dependency of boron complexation. Moreover, permeate flux was not affected by the polymer concentration in the conditions studied (polymer concentration <= 10 g/L; pressure drop: 2 bar). Dynamic and static light scattering measurements showed that gyration radius of the polymers rises by dilution or by increasing pH of the solutions. Furthermore, a two-step equilibrium model was correlated with the experimental boron retention data. Having high boron binding affinity, hydrolytic stability and efficiency in boron removal, the synthesized copolymers possessing DADMAC segments seemed to be attractive and useful for large scale water treatment with PEUF systems

Use of Specifically Tailored Chelating Polymers for Boron Removal from Aqueous Solutions by Polymer Enhanced Ultrafiltration

Two selective functional polychelatogens, namely hydroxyethylaminoglycerol functioned poly(glycidylmethacrylate (PNS) and Poly(4-Vinyl-1,3-dioxalan-2-one-co-vinyl acetate) (COP) were synthesized and utilized in polymer-enhanced ultrafiltration (PEUF) to remove boron from the aqueous solution. The effect of operating parameters on boron retention was investigated. PNS was synthesized in three molecular weights to observe the effect of molecular weight in borate retention. Increase in pH increased boron retention for all of the synthesized polymers. Decrease in loading resulted in an enhancement in retention values when COP, medium (PNSM) and the low molecular weight of PNS (PNSL) were used. No significant change was observed in the permeate flux with COP (41L/m2 center dot h), PNSL (48L/m2 center dot h) and PNSM (47L/m2 center dot h). However, a decrease in the loading led to a decrease in the permeate flux for high molecular weight PNS (PNSH). Conformational changes in the polymer structure were examined using dynamic and static light-scattering. Retention results for all of the polymers were found to be remarkably higher than the literature, when polyvinyl alcohol was used as the chelating agent. Satisfactory retention results were obtained using both PNSL (R: 54%) and PNSM (R: 57%), showing that PEUF can be employed effectively for borate removal using the specifically tailored polymers

Imino-bis-propane diol functional polymer for efficient boron removal from aqueous solutions via continuous PEUF process

Boron contamination is an environmentally serious problem especially due to its hazards on plants. In this work, newly synthesized poly (vinyl amino-N, N'-bis-propane diol) (GPVA) is presented as an excellent chelating polymer for boron removal. Boron concentration could be reduced from 10 ppm down to 0.4 ppm via total recycle Polymer Enhanced Ultrafiltration (PEUF). Experiments revealed that the polymer shows the highest PEUF boron rejections (96% at pH 9.0) reported so far, without precipitation in a wide concentration range. Detailed investigations such as effect of pH, loading (boron-to-polymer mass ratio) and polymer concentration showed that, the boron binding is highly pH dependent and increases with boron concentration at constant loading. Furthermore, permeate flux was found as nearly independent from polymer concentration up to 10 g/L at 200 kPa pressure drop. In addition, gyration radius of the polymer in solution increases while increasing pH and polymer concentration in the presence of boron as inferred from Dynamic and Static Light Scattering measurements. Regarding with high efficiency and hydrolytic stability of GPVA, its use in combination with PEUF would be of interest for large scale and long term use in boron removal

Placental and Umbilical Cord Blood Oxidative Stress Level and Telomere Homeostasis in Early Onset Severe Preeclampsia

Objective Although the etiopathogenesis of preeclampsia (PE) is unknown, evidence suggests that it may be associated with increased oxidative stress. Studies have shown that oxidative stress can affect DNA fragments called telomeres. However, the interactions of PE, oxidative stress, and telomere length are not clearly known. This study aims to evaluate the oxidative/anti-oxidative stress balance in the placenta and umbilical cord and examine the effect of oxidative stress on telomeres. Materials-Method Cord blood and placental samples were collected from 27 pregnant women with severe PE (28 0/7-33 6/7gestational weeks) and 53 healthy pregnant women. Telomere length (TL) was measured by real-time PCR in the cord blood and placenta tissue. Total antioxidant status (TAS) and total oxidant status (TOS) levels were measured in the cord blood and placenta tissue using a colorimetric method. Results No significant differences were found between groups regarding age, BMI, gravida, parity, and newborn gender (p>0.05). Cord blood and placental TL of PE patients were significantly shorter than the control group, while cord blood and placental TAS and TOS levels were higher (p<0.05). The results of a multivariate logistic regression analysis showed that the level of placental TOS in PE patients (OR=1.212, 95% CI=1.068-1.375) was an independent risk factor affecting PE. Conclusion This study found that oxidative stress is an independent risk factor in the development of PE and shortens TL in both placental and umbilical cord blood. Future research on telomere homeostasis may offer a new perspective for the treatment of PE. © 2022 Georg Thieme Verlag. All rights reserved