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The popularity and high price of durian make quality control in terms of ripeness very important, which in turn depends heavily on harvesting at an appropriate maturity stage. To date, reports on data-driven methods for maturity prediction are scarce, with many rather focusing on ripeness prediction. Herein, we report the first disclosure of key molecular markers in the liquid extract of durian peduncle that can be a predictive tool for maturity. Multiple chromatographic and spectroscopic techniques including TLC, HPLC, PS-MS, LC–MS/MS, and NMR, were used to characterize chemical profiles of the aqueous extracts from peduncles at different ages. Four compounds that show positive correlations with maturity were identified as sucrose, asparagine, arginine, and pipecolic acid, with asparagine as the most abundant species. This finding paves the way for more research of high impact such as the relationship between biochemical reactions in peduncle and pulp, and the development of accurate and non-destructive sensors for maturity prediction.

The organogels poly(styrene-co-divinylbenzene), PS gel (1); poly(styrene-co-divinylbenzene-co-vinylpyridine), PS-VP gel (2); poly(styrene-co-divinylbenzene-co-vinylbenzoic acid), PS-VBA gel (3); and poly(styrene-co-divinylbenzene-co-styrenesulfonate), PS-SS gel (4) were prepared with limonene by varying the concentration of cross-linker and comonomer to control the properties of the gels. Limonene was used as the swelling solvent due to its low toxicity and environmental friendliness. Additionally, 4-vinylpyridine (VP), 4-vinylbenzoic acid, and 4-styrenesulfonate were introduced as cationic and anionic moieties to act as interaction units. An increase in the divinylbenzene ratio improved the mechanical strength, as evidenced by an increase in the G′ value; for example, the G′ of gel 3 improved from 15,000 Pa with 5% cross-linking to 93,000 Pa with 10% cross-linking. However, the increased cross-linking reduced the solubility in limonene, resulting in a decrease in the swelling ratio from 1.5 to 0.7. Cationic gel 2 can adsorb anionic compounds, while anionic gel 4 can adsorb cationic compounds. Gel 2 with 5 mol% VP was able to adsorb approximately 4.4 mg/g of an anionic dye, while gel 4 with 5 mol% SS was able to adsorb approximately 6.6 mg/g of a cationic dye. The limonene organogels were used for lipophilic drug storage and the controlled release of testosterone due to their dense polymer network.

Oilfield scale inhibitors have been used for many decades, mostly to fight carbonate and sulfate scaling. Many inhibitors are known, but only a few show good biodegradation to make them environmentally acceptable in areas with strict regulations, such as offshore Norway. Often high biodegradation is at the expense of other useful properties, such as thermal stability for high-temperature squeeze applications. We have now synthesized and investigated a new class of polycarbonate polymers with pendant anionic functional groups (carboxylate and phosphonate) as potential oilfield scale inhibitors. These polymers have a carbonate group in the backbone. Polymers with carboxylate and phosphonate side groups were prepared. We report here the scale inhibition performance of these polymers at 100 °C against both calcite and barite scaling at typical North Sea conditions in dynamic tube-blocking equipment, both before and after aging at 130 °C. The phosphonated copolymer gave very good performance against calcite sc...

The aim of this research is to develop a transdermal drug delivery system (TDDS) for testosterone by novel physical chain entanglement organogels in propylene glycol. The organogels have been widely studied for TDDS, due to their good interactive properties with skin. The physical gel with amphiphilic polymers was studied and evaluated in this study, in order to fabricate the controllable release and sufficient permeability through the skin barrier of transdermal testosterone. The novel sugar amine-derived gel, that is poly(vinyl benzyl-N-methyl-D-glucamine) gel (poly(VbNMDG) gel), was obtained by the subsequent polymerization of the neutral form (VbNMDG) and cationic form (VbNMDG-H) with an organic base as a promotor. The gel showed electrostatic interactions as indicated by FTIR, and responsive behavior under alkali conditions. The network structure is generated from multi-interaction of linear polymer chain, confirmed by in situ polymerization. This was evidenced by the rheological measurement, which confirmed a gradual change from sol to gel-like behavior. Regarding the drug release, we set the target release time at 24 h, which is an effective treatment condition for hypogonadism. For the permeation, it was studied by using abdominal rat skin as a membrane. The d -limonene/PG synergistic activity enhanced the permeability, resulting in the highest coefficient (KD/L) at 8.80 ± 1.95 cm/h at 10% Limonene/PG. Furthermore, we evaluated the carbon chain length effect by copolymerizing of benzalkonium chloride. The dodecyl (C-12) group showed significant penetration enhancement, indicated by the coefficient which was 13.76 ± 5.45 cm/h.

d-limonene, a terpene and natural compound, has been found to be an excellent penetration enhancer for transdermal drug delivery (TDD). It hence has been incorporated within various transdermal formulations. Herein, we report the application of polystyrene gel swollen with d-limonene and its derivatives for TDD. Poly(styrene-co-divinylbenzene) (PS gel), poly(styrene-co-divinylbenzene-co-4-vinylpyridine) (PS-4VP) gel and poly(styrene-co-divinylbenzene-co-(vinylbenzyl) trimethylammonium chloride) (PS-VBAC gel) were employed as chemical gels to improve the stability of the TDD substrates. The drug permeation properties from the PS gels swollen in limonene were examined, regarding the effect of its network density as well as their rheological properties. The lowest density of the network showed the highest steady flux of the permeation at 43.7 &plusmn, 0.3 &mu, g/cm2. FT-IR spectra were confirmed for PS-4VP and PS-VBAC, bearing cationic moieties and they could control the release of ibuprofen by the electrostatic interaction at the interface of organogel and skin. The steady state flux of skin permeation got low values from 55.2 &plusmn, 0.8 to 11.6 &plusmn, 2.0 &mu, g/cm2, when the cationic moieties were increased. Moreover, the chemical network of PS gel swollen in limonene showed high mechanical stability illustrated by elastic modulus (G&rsquo, ) of about 98 kPa for 10% cross-linked PS gel. The developed PS gels swollen in limonene show highly promising results, suggesting their possible application in TDD.