Towards the preparation of sustainable superplasticizers for geopolymeric pastes via radiation-induced grafting of sulfonic group-bearing monomers onto corn starch.

To address escalating environmental and sustainability concerns of petroleum-based superplasticizers (SPs), this work aims to develop sustainable and eco-friendly starch-based SPs using gamma radiation for maintaining the desired workability of geopolymeric pastes. Specifically, two green SPs were prepared from starch via radiation-induced grafting of two sulfonic group-bearing monomers, namely 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and 4-styrene sulfonic acid sodium salt (Na4SS). The grafting reaction was improved by initial modification of starch with glycidyl methacrylate to insert vinyl groups into the starch backbone. The modified starch samples were characterized by a variety of analytical techniques such as FTIR, 1H NMR, EDX, SLS, and viscometry. The prepared SPs exhibited high stability in aqueous 5 % NaOH. The effect of the prepared SPs on the fresh properties of GGBFS/MK geopolymer was studied using the mini slump test, zeta potential, adsorption capacity, and setting time. They significantly improved the paste flowability and dispersion compared to the control. Notably, the aromatic Na4SS-grafted starch displayed a comparable enhancement to the commercial PNS, while outperforming the aliphatic AMPS-grafted sample. This emphasizes the potential of these green SPs to address the challenges posed by the petroleum-based SPs and maximize the benefit of using starch as a green renewable resource.

Phospholipid profile of rat testis, its unique high level of monolysocardiolipin and its lipolytic capabilities in vitro. A chromatographic analysis.

The phospholipid profiles of testes and heart of 1-, 3-, and 6-month-old rats and their in vitro response to the endogenous phospholipases at pH 7.4 and 38 degrees C for 60 min were analyzed by TLC technology and densitometry. A noticeable high level of monolysocardiolipin (MLCL) was shown in rat testes of all samples analyzed (1-, 3-, and 6-month-old), both control and incubated. In contrast, rat heart control samples revealed a high level of CL and no MLCL was detected. MLCL was only produced subsequent to in vitro incubation of whole tissue homogenate at pH 7.4 and 38 degrees C for 60 min, with concurrent reduction of CL. Alkenyl phosphatidyl ethanolamine (PE) was the major plasmalogen of rat testes. Following in vitro incubation, (a) a very low level of lyso PE plasmalogen was produced only in 3- and 6-month-old rat testes, (b) ceramide was also produced in all testes analyzed with concurrent reduction of sphingomyelin indicating the action of sphingomyelinase. These data clearly illustrate, for the first time, the presence of high levels of MLCL in all rat testes studied which probably is related to the physiological activity in vivo and requires further investigation.

Studies on the endogenous phospholipids of chick embryo myocardium and their in vitro hydrolysis by endogenous phospholipases during embryogenesis.

The phospholipid profiles of the myocardium (from 10- and 18-day old chick embryos and 13-day old chick) and their in vitro response to the endogenous lipolytic enzymes (mainly of the phospholipase group) at pH 7.4 and 38 degrees C for 60 min were analyzed by TLC technology and densitometry. Cardiolipin (CL) was shown to be one of the major phospholipids of the chick embryo myocardium and its concentration increased as the chick embryo advanced in development. Monolysocardiolipin (MLCL) was produced subsequent to in vitro incubation of whole tissue homogenates in all myocardia studied as well as a concurrent reduction in CL. This deacylation of CL increased in magnitude as the chick embryo advanced in development indicating its age relatedness. The level of phosphatidyl ethanolamine (PE) plasmalogen was also high in all myocardia studied. Lyso alkenyl PE (LPE) was produced subsequent to in vitro incubation and its level increased as the chick embryo advanced in development, indicating PLA(2) action on the sn-2 fatty acid of PE. Phosphatidyl choline (PC) plasmalogen was also present in the chick embryo myocardium and its level increased gradually as the chick embryo advanced in development. In contrast, yolk-sac membrane contains very minute amounts of CL and PE. No PC was detected and no LPE was formed following in vitro incubation. The yolk of the unfertilized chicken egg has no CL and has very minute amounts of PE, no PC and no lysophospholipids were detected following in vitro incubation in all samples analyzed.

On the differential lipolytic capabilities of rat spleen and cardiac muscle. An in vitro incubation in conjunction with chromatographic and densitometric analysis.

The phospholipid profiles of newborn, young adult and aged rat heart and spleen and their in vitro response to endogenous phospholipases at pH 7.4 and 38 degrees C for 60 min were analysed by thin layer chromatography (TLC) technology and densitometry measurement. The noticeable high level of cardiolipin (CL) and its preferential deacylation, as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of rat cardiac muscle (newborn, young adult and aged) but the least prevalent in rat spleen. The level of ethanolamine plasmalogen (PE) was high in both the rat spleen and cardiac muscle (newborn, young adult and aged). Following in vitro incubation, the reduction in the level of PE and the high level of lyso alkenyl PE produced were most conspicuous in rat spleen (newborn, young adult and aged) and noticeably less in rat cardiac muscle. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of these two tissues, and probably are related to their physiological activities in vivo.

Comparative studies of the endogenous phospholipids and their in vitro hydrolysis by endogenous phospholipases of various tissues from 7-day-old chicks: a thin layer chromatographic and densitometric analysis.

The phospholipid profiles of heart, kidney, and pectoral muscle of 7-day-old chicks and their in vitro response to the endogenous lipolytic enzymes (mainly in the phospholipase group) at pH 7.4 and 38 degrees C for 60 min were analysed by TLC technology and densitometry. The noticeable preferential deacylation of cardiolipin (CL) as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of chick cardiac muscle, but the least prevalent in chick pectoral muscle. Deacylation of ethanolamine plasmalogen (PE) as revealed by the formation of the corresponding lyso alkenyl derivative was also prominent in cardiac muscle, but much less so in kidney and none at all was detected in pectoral muscle. The level of sphingomyelin (SM) was much higher in kidney than heart and pectoral muscle. Following in vitro incubation, the reduction in the level of SM and the high level of ceramide (Cer) production were most conspicuous in kidney, less in cardiac muscle and least in pectoral muscle. The hydrolysis of PE and SM confirm the action of endogenous PLA(2) and endogenous sphingomyelinase on PE and SM respectively. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of the tissues studied and are probably related to their physiological activities in vivo.

Studies on the endogenous phospholipids of mammalian kidney and their in vitro hydrolysis by endogenous phospholipases: a thin layer chromatographic and densitometric study.

The phosphoglycerides profile of six species of mammalian kidney (guinea pig, pig, cat, dog, mouse and rat) and their in vitro response to the endogenous phospholipases were determined by TLC technology in conjunction with densitometric measurements. Changes in their phospholipids profile subsequent to in vitro incubation of whole tissue homogenate of these kidneys for 60 min, at pH 7.4, 38 degrees C, and prior to phospholipids extraction have shown that the deacylation of the endogenous cardiolipin (CL) is the most prevalent lipolytic event of all mammalian kidneys studied. Concurrent with the deacylation of CL, there was also formation of monolysocardiolipin (MLCL) and a reduction in CL level. To a much lesser extent, lyso alkenyl phosphatidyl ethanolamine (LPE) was also produced concomitant with a decrease of the endogenous alkenyl phosphatidyl ethanolamine (PE) level. The deacylation of PE plasmalogen to its lyso form confirms the action of endogenous PLA(2) releasing sn-2 fatty acids.

Age-related changes of the endogenous cardiolipin and plasmalogens of guinea pig kidney and their in vitro hydrolysis by endogenous phospholipases: a thin layer chromatographic analysis in conjunction with densitometric measurement.

The phosphoglycerides profile of guinea pig kidney, fetal, young adult, and aged, and their in vitro response to the endogenous lipolytic enzymes, mainly in the phospholipase group were determined by TLC technology in conjunction with densitometric measurement. Changes in phosphoglycerides profile subsequent to in vitro incubation of these tissues at pH 7.4, and 38 degrees C for 45 min and prior to phospholipid extraction has provided evidence relating to their respective lipolytic enzymes capabilities and age. These changes are mainly related to endogenous cardiolipin (CL), alkenyl phospholipids (phosphatidyl ethanolamine and phosphatidyl choline) and their endogenous deacylation to their respective lyso derivatives monolysocardiolipin (MLCL), lyso alkenyl phosphatidyl ethanolamine (LPE), and lyso alkenyl phosphatidyl choline (LPC) by endogenous phospholipases. The hydrolysis of the plasmalogen confirms the action of endogenous PLA(2) on sn-2 fatty acids of these compounds.