Monolithic stationary phases prepared via cyclic anhydride ring-opening polymerization as tunable platforms for chromatographic applications

Polymer monolithic stationary phases were prepared based on a cyclic anhydride as a reactive and tunable platform via ring-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.

The efficacy of mindfulness-based programs in reducing anxiety among nurses in hospital settings: A systematic review

BACKGROUND

The increasing pressure of their professional duties has led to a notable concern regarding the mounting anxiety levels among nurses. The ongoing discussion revolves around the efficacy of mindfulness as a means to alleviate anxiety in nurses.

AIM

This systematic review evaluated the effectiveness of mindfulness in reducing anxiety among nurses.

METHODS

The evaluation followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. An extensive and comprehensive search was conducted across eight databases to identify studies that utilized randomized controlled trials (RCTs) and were published in English between 2011 and 2022. Independently, two reviewers assessed the validity of the randomized controlled trials using the Consolidated Standards of Reporting Trials criteria. Additionally, two authors independently employed the Risk of Bias in Non-Randomized Studies of Interventions (ROBINS-2) method to evaluate the potential bias in the RCTs.

RESULTS

Eight randomized controlled trial studies that were deemed eligible were included in the current analysis. Based on the literature review, it was determined that mindfulness-based training can assist nurses in reducing their anxiety levels. Furthermore, the effectiveness of mindfulness-based programs in enhancing nurses' mindfulness and self-compassion has been firmly established.

CONCLUSIONS

Based on existing literature, mindfulness-based interventions have proven to be effective in reducing anxiety levels among nurses. However, in order to enhance the overall quality of research, it is necessary to implement more rigorous controlled designs that include randomization. Additionally, larger sample sizes with a diverse range of participants are needed to establish and validate the effectiveness of mindfulness-based programs in alleviating anxiety among nurses.

LINKING EVIDENCE TO ACTION

Implementing mindfulness-based training in healthcare organizations can offer numerous benefits. One such advantage is that it can help nurses in reducing anxiety and enhancing their ability to handle the pressures associated with their profession.

STUDY REGISTRATION

PROSPERO Protocol registration ID: CRD42023475157.

Nurses' Attitudes Concerning Analgesia Administration for Pediatric Patients with Sickle Cell Disease in Jordan: A Cross-Sectional Study

BACKGROUND

Pain management of vaso-occlusive crises is a fundamental priority in the lifelong care of children and adolescents with sickle cell disease.

AIM

This study examined nurses' attitudes towards caring for children with sickle cell disease (SCD) and SCD pain management in those with vaso-occlusive pain.

METHOD

A structured, self-reporting survey was provided to a convenience sample of 298 nurses across 10 hospitals serving Jordan's northern and middle regions. Descriptive and inferential statistics were applied for data analysis.

RESULTS

Most nurses (77%) perceived their experience caring for children with SCD as positive. Many nurses (65%) felt frustrated about caring for these children during painful episodes. Participants identified workload and inadequate time as limiting their ability to address the analgesic needs of children with SCD. Receiving structured education specialized in pain management and more years of experience in nursing significantly predicted less hesitancy in administering opioid-based analgesia.

CONCLUSIONS

The results of this study provided further insight into factors that potentially contribute to vaso-occlusive pain crises frequently being poorly managed and inadequately addressed among pediatric patients. Nurses' attitudes and understanding of SCD pain management must be addressed to advance the clinical practice of managing pain in children with SCD.

Forensic analysis of mosquito blood meal digestion process and the impact of heroin opiate: determination of the post-feeding interval as a PMI estimation

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 pipiens L. 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.

Preparation of value-added metal-organic frameworks for high-performance liquid chromatography. Towards green chromatographic columns

This work applies the concepts of green chemistry, where polyethylene terephthalate (PET) bottles were used as the acid-dicarboxylic linker source for the synthesis of MIL-53(Al) metal organic frameworks (MOFs) and then used as a stationary phase for the separation of various solutes and compared with MIL-53(Al) synthesized from traditional terephthalic acid. Both synthesized MIL-53(Al) MOFs were characterized by scanning electron microscopy (SEM), FT-IR, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and specific surface area analysis. Eight groups of standard analytes in addition to real samples were tested to evaluate the separation performance of the MIL-53(Al) packed columns in HPLC under various chromatographic conditions. Based on elution order of the studied compounds and the effects of mobile phase composition, the working mechanism was reversed phase mode in the presence of size-exclusion effects for large molecules, which exceeded the dynamic diameter of MIL-53(Al) (~7.6 Å). The effects of stationary phase sieving, mobile phase flow rate and composition, injected sample mass, and temperature were investigated relative to the chromatographic behavior of MIL-53(Al). MIL-53(Al) particle sieving before packing reduced peak broadening and significantly enhanced the chromatographic performance of the prepared columns up to 2.26 times relative to the number of theoretical plates. The MIL-53(Al) packed columns offered high-resolution separation for all studied mixtures with R_s >2 and good stability and long-term durability. At optimal conditions, the prepared columns exhibited efficiencies between 5600-63200 plates m^-1. Higher efficiencies were observed for alkylbenzenes and polyaromatic hydrocarbons as the organic linker in the MIL-53(Al) structure, which improved retention and separation of aromatics through π-π interactions. Thermodynamic parameters including ΔH, ΔS, and ΔG for the transfer of analyte from the mobile phase to the MIL-53(Al) stationary phase were studied. Compared with previously cited MOFs packed columns, the present MIL-53(Al) columns gave comparable selectivity and much better efficiency for most of the studied chemicals at optimum conditions, indicating the feasibility of MIL-53(Al) as a stationary phase for HPLC applications.

Development and Validation of a Rapid and Efficient Method for Simultaneous Determination of Scopolin and Scopoletin in Convolvulus Species by Ultra- high-performance Liquid Chromatography-Tandem Mass Spectrometry

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.

Determination of Monoaromatic Hydrocarbons in Water Samples by Nano-Liquid Chromatography using a Composite Carbon Nanotubes- Lauryl Polymethacrylate Capillary Monolithic Column

Background:

This work reports a green analytical method for the determination of organic environmental pollutants using nano-liquid chromatography with a self-made column for rapid, sensitive, inexpensive and efficient analysis of BTX pollutants in water. The applications of monolithic nanoscale columns for quantitative analysis of environmental real samples are very limited in the literature.

Methods:

A capillary column containing a composite of multi-walled carbon nanotubes incorporated into a lauryl methacrylate-co-ethylene dimethacrylate porous monolithic polymer was fabricated for the determination of BTX pollutants in real water samples.

Results:

Baseline separation was accomplished at 0.4 µL/min flow rate with UV-detection set at 208 nm. Under the optimum conditions, the calibration curves were validated over the range of 1.0-500 µg/L with R2 more than 0.9992. The detection limits of benzene, toluene, o-xylene and m/p-xylene were 0.25, 0.05, 0.075 and 0.05 µg/L, respectively. After a simple extraction process with a theoretical preconcentration factor equal to 200, the recovery values in Milli-Q, tap and sea water samples were found to be ranged from 84.85 to 97.84% with %RSD less than 7.5. Furthermore, we reported a comparison between our prepared composite column with a commercial C18 silica based column which is the most used in such analytical field. Each column demonstrated its advantages from different analytical aspects.

Conclusion:

The application of monolithic columns and nano-scale LC for routine analysis of environmental samples is very promising as the use of monolithic capillary columns offers several advantages over conventional scale particulate packed columns.