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This study introduces the synthesis and characterization of advanced silica core–shell nanostructures, with an emphasis on the innovative Si-ACS (Silica Acorn Core–Shell) design and its modified counterparts. Employing the classic Stöber method, SiCore particles were first produced, followed by the creation of the acorn-like Si-ACS structures. A key aspect of this research is the exploration of the effects of CTAB and TEOS concentrations on the morphology and properties of the silica shells. The study reveals that surfactant concentration influences shell morphology from corn-like to uniformly thin structures, as well as the shell thickness. Specifically, increasing the CTAB concentration from 45.8 mM to 166.9 mM increased the silica shell thickness from 160 to 280 nm, demonstrating the significant impact of surfactant concentration on shell formation. Si-ACS particles exhibited a surface area of 55.54 m2/g and a pore volume of 0.64 cm3/g, as evidenced by BET measurements, indicating successful mesopore formation critical for catalytic and adsorption applications. The materials were further modified with cholesterol and tetraethyl pentaamine (TEPA), which was confirmed by FT-IR analysis. Additionally, the study demonstrates the application of these functionalized nanostructures as chromatographic columns. In particular, the dual-mode interactions of Si-ACS-CHOL-TEPA significantly improve the separation of phthalate esters, thereby highlighting the potential of these materials in advanced analytical and biotechnological applications.

Polymer monolithic stationary phases were prepared based on a cyclic anhydride as a reactive and tunable platform viaring-opening post-polymerization using primary amines, octadecylamine and benzylamine. The characterization techniques indicated the insertion of the functional groups into the original monoliths and confirmed the amidation reactions. The post-polymerization modification also improved the monolith's thermal and mechanical stability and induced significant improvement in their surface area. The stationary phases were synthesized inside small dimension stainless-steel columns (2.1 mm i.d. × 50 mm length). The prepared columns before and after modifications have been tested for the separation of the alkylbenzene series and some polycyclic aromatic hydrocarbons (PAHs) as model compounds. In all cases, the chromatographic performance in terms of the height equivalent to a theoretical plate on the functionalized monoliths was remarkably improved when compared with that on the unmodified monolith, which was between 9.59–39.49 μm and 4.08–31.50 μm using monoliths modified with octadecylamine and benzylamine, respectively. Under the same chromatographic conditions, the functionalization of monoliths with octadecylamine provided more hydrophobic interactions and enhanced the retention of alkylbenzenes, while the modification of monoliths with benzyl groups improved the separation and the retention of the PAHs through the strong π–π interactions. However, post-modification polymerization with octadecylamine and benzylamine enhanced the separation efficiency of the prepared columns toward all studied compounds. The repeatability of the injections on the same column and the reproducibility of the prepared columns have been studied for some selected parameters and estimated in terms of percent relative standard deviation (%RSD) for some of the studied compounds. The repeatability of the prepared columns was ≤9.42% (n= 5) based on run-to-run injections and ≤9.48% based on day-to-day injections for five successive days. The reproducibility levels, on the other hand, were ≤20.95% for all studied parameters in all cases. To assess their performance for the analysis of real samples, the applicability of the prepared columns was examined for the separation of the active ingredients extracted from some commercial pharmaceutical formulations and for the separation of tea water extract constituents. The validation data show the suitability of the columns for practical use in the routine analysis of these samples.

Females of some mosquito species are anthropophilic, as they feed on human blood to support egg production and, hence, are forensically valuable if found at a crime scene. The present study investigated the blood meal digestion process in Culex pipiensL. both with and without heroin and proposed a method for estimating the post-feeding interval (PFI). Mosquitoes were fed on a control mouse, a heroin-injected mouse, or in vitro heroin-treated mouse blood. The blood meal digestion was then investigated at different hours post-feeding. Data showed that the blood meal size ingested by control mosquitoes was 0.681 ± 0.04 mg/mosquito and was completely digested within 45 h post-feeding. An estimation of the PFI was proposed in terms of the rate of hemoglobin (Hb) digestion. The blood meal size of the mosquitoes fed on the in vitro heroin-treated blood and the heroin-injected mouse was 0.96 ± 0.06 and 0.79 ± 0.01 mg/mosquito and was completely digested within 50 and 55 h post-feeding, respectively. The digestion of Hb started similarly in all experimental mosquitoes until 10 h post-feeding, after which it significantly decreased in heroin-treated blood meals compared with the control ones. This may suggest that heroin impacted the digestion process, as it took an extra 5–10 h to complete. These findings could be valuable in the forensic context since an estimation of PFI is proposed as a potential estimation of the postmortem interval (PMI). However, care should be taken as heroin in the host blood has significantly impacted the overall digestion process and, hence, may bias the PFI/PMI estimation.

Background: Convolvulus species are extensively used in traditional medicines for the treatment of peptic ulcer diseases primarily associated with the presence of many bioactive compounds, such as coumarins. Methods: A validation and improvement of a rapid, sensitive and simple technique for bioactive compounds analysis of scopolin and scopoletin in Convolvulus pilosellifolius (CP) and Convolvulus austroaegyptiacus (CA) plant extracts using UHPLC-MS/MS were performed. Both plants extracts were subjected to high-resolution DART-ToF-MS technique for fast profiling of their constituents. Results: DART-ToF-MS spectra proved the presence of experimental mass at 193.05137 and 355.10371 m/z in the extract of CA plant and at 193.05084 and 355.10365 m/z in CP plant extract for scopolin and scopoletin compounds, respectively. The total chromatographic analysis time was less than 10 min with excellent resolution and negligible matrix effect. The validated parameter showed good linearity (R2 ≥0.998) over a wide concentration range of 0.05-10.0 μg mL-1 for both scopolin and scopoletin, detection limits of scopolin and scopoletin were 0.03 and 0.01 μg mL-1, respectively. The method also showed good intraday and interday precisions (RSD<4.33%). The recovery percentage values were between 97.04 and 99.97% at three added concentration limits. The highest content of scopolin (3.485 mg g-1) and scopoletin (0.795 mg g-1) was detected in CA ethanolic extract. The studied plants were finally compared with all previous reports in terms of scopolin and scopoletin content. Conclusion: The results indicate that the suggested method can be used for regular analysis of active compounds in medicinal plant extracts.