Graded-index Research Articles

Sustainable HPLC technique for measurement of antidiabetic drugs: Appraisal of green and white metrics, content uniformity, and in vitro dissolution

Abstract Green chemistry and white chemistry are two approaches to chemistry that prioritize sustainability and environmental protection. The pursuit of green chemistry is to develop chemical processes and products that decrease or stop the use and generation of dangerous materials. In contrast, white chemistry focuses on developing energy-efficient, sustainable chemical processes that produce minimal waste. Our study evaluated the environmental friendliness of the suggested approach, using eight greenness appraisal techniques, including analytical eco-scale, analytical method volume intensity, HPLC-environmental assessment tool, analytical method greenness score, analytical greenness, analytical greenness metric for sample preparation, green analytical procedure index, and complexgreen analytical procedure index, in addition to the unique metric blue applicability grade index of white chemistry. We have developed and validated a highly effective and reliable method for concurrently analyzing designated pharmaceutical medications characterized in metformin (MET) and empagliflozin (EMP) formulations, including their degraded products. This method is cost-effective, specific, and environmentally friendly, utilizing reversed-phase high-performance liquid chromatography with an XBridge BEH C8 column (150 mm × 4.6 mm, 5 μm) at a flow rate of 1.0 mL·min−1, an injection volume of 5.0 μL, a column oven temperature of 50°C, a wavelength of 224 nm, and a mobile phase comprised of phosphate buffer adjusted at pH 6.8 and acetonitrile in gradient mode. In the HPLC method, linearity has been achieved over the concentration range of 10–106 and 30–1,050 µg·mL−1 for EMP and MET, respectively, with correlation coefficients more than 0.999 and good recoveries within 98–102%. An assessment of the content uniformity of finished products confirmed that they met the declaration’s acceptance standards (85–115%). A comparative study has been successfully conducted on generic and reference products, demonstrating their similarity. The suggested approach was validated by adhering to international council for harmonisation criteria.

Cutting-edge HPLC and MCR techniques for synchronically quantifying anticholinergic drugs in the presence of C12 and C14 homologs: Robust application to green and white chemistry.

Green and white chemistry are vital to revolutionizing the chemical industry through their unparalleled potential to enhance sustainability and efficiency. In this study, nine sustainability tools of both green and white metrics, including green analytical procedure index (GAPI), ComplexGAPI, analytical greenness, analytical greenness metric for sample preparation, Analytical Eco-Scale (ESA), analytical method greenness score, high-performance liquid chromatography- environmental assessment tool (HPLC-EAT), analytical method volume intensity, and blue applicability grade index (BAGI), have been developed for appraising environmental friendliness for both innovative and straightforward mean centering of ratio spectra (MCR) and reversed-phase high-performance liquid chromatography (RP-HPLC)strategies utilized for concurrent analysis and separation of cyclopentolate (CYC) and C12 and C14 homologs of benzalkonium chloride (BNZ) in pure and ophthalmic solution. The mobile phase, formed of buffer phosphate and acetonitrile (35:65, v/v), was adjusted to pH 6.3, and 215-nm UV detection was used. The experimental flow rate was 2.0 mL min-1, and the analytical column was L11 Inertsil Ph-3 (150 mm × 4.6 mm, 5 µm). All sequences were run at 25°C in the column oven. The MCR approach effectively resolved the drug's spectral overlapping. CYC and BNZ employed this approach at 227.5 and 220.4 nm, respectively. As part of the HPLC analysis, an isocratic method was employed with phosphate buffer and acetonitrile in the mobile phase at 35:65. A correlation coefficient greater than 0.999 was observed between the calibration curves for the HPLC and MCR methods in the ranges of 20-320 µg mL-1 and 5-30 µg mL-1 for all drugs. The technique yields excellent primary recovery rates, ranging from 97.2% to 100.5%. The recommended approach has been validated according to International Council for Harmonizationguidelines.

A practical and eco-friendly method for the determination of polycyclic aromatic hydrocarbons in açaí-based food products by vacuum-assisted sorbent extraction coupled to gas chromatography-mass spectrometry

For the first time, a method for the simultaneous analysis of fifteen polycyclic aromatic hydrocarbons (PAHs), including light and heavy PAHs, in açaí-based food products (AFPs) was developed using vacuum-assisted sorbent extraction (VASE) combined with gas chromatography-mass spectrometry (GC–MS). The method requires no organic solvents and is amenable to full automation. To achieve optimal analytical extraction conditions, VASE parameters including stirring rate, extraction time, desorption temperature, desorption time, preheat time, and preheat temperature were optimized using sequential multivariate optimization. The method was validated and yielded limits of quantification below 1 µg kg−1 for all analytes, with recoveries ranging from 65 % to 112 % and good precision (≤11 % relative standard deviation). Additionally, the greenness and practical aspects of the method were investigated using the Green Analytical Procedure Index (GAPI), eco-scale, and the Blue Applicability Grade Index (BAGI), respectively. The VASE-GC–MS approach is suitable for routine analysis and exhibits characteristics of a green analytical method. No PAHs were detected above the limits of detection in thirty samples of AFPs.

Radiomics analysis using magnetic resonance imaging of bone marrow edema for diagnosing knee osteoarthritis.

This study aimed to develop and validate a bone marrow edema model using a magnetic resonance imaging-based radiomics nomogram for the diagnosis of osteoarthritis. Clinical and magnetic resonance imaging (MRI) data of 302 patients with and without osteoarthritis were retrospectively collected from April 2022 to October 2023at Longhua Hospital affiliated with the Shanghai University of Traditional Chinese Medicine. The participants were randomly divided into two groups (a training group, n = 211 and a testing group, n = 91). We used logistic regression to analyze clinical characteristics and established a clinical model. Radiomics signatures were developed by extracting radiomic features from the bone marrow edema area using MRI. A nomogram was developed based on the rad-score and clinical characteristics. The diagnostic performance of the three models was compared using the receiver operating characteristic curve and Delong's test. The accuracy and clinical application value of the nomogram were evaluated using calibration curve and decision curve analysis. Clinical characteristics such as age, radiographic grading, Western Ontario and McMaster Universities Arthritis Index score, and radiological features were significantly correlated with the diagnosis of osteoarthritis. The Rad score was constructed from 11 radiological features. A clinical model was developed to diagnose osteoarthritis (training group: area under the curve [AUC], 0.819; testing group: AUC, 0.815). Radiomics models were used to effectively diagnose osteoarthritis (training group,: AUC, 0.901; testing group: AUC, 0.841). The nomogram model composed of Rad score and clinical characteristics had better diagnostic performance than a simple clinical model (training group: AUC, 0.906; testing group: AUC, 0.845; p < 0.01). Based on DCA, the nomogram model can provide better diagnostic performance in most cases. In conclusion, the MRI-bone marrow edema-based radiomics-clinical nomogram model showed good performance in diagnosing early osteoarthritis.

Squamous cell carcinoma of ear and temporal bone: A retrospective study on clinicopathological predictors.

Ear and temporal bone squamous cell carcinoma (ETBSCC) is a rare and aggressive malignant tumor with minimal clinicopathological studies. The object of this study was to retrospectively evaluate the predictive effect of clinicopathological variables on the 5-year overall survival (OS) rate of ETBSCC patients in a single tertiary medical center in Tianjin, China. A cohort of 44 patients with diagnosed ETBSCC from December 2012 to August 2022 were retrospectively studied. Univariate and multivariate analysis were, respectively, performed for the assessment of clinicopathological predictors, including sex, age, history of chronic suppurative otitis media (CSOM), lesion side, diameter, the choice of surgical approach, parotidectomy, neck dissection, adjuvant therapies, T stage, lymph node metastasis, tumor grade, margin, perineural invasion (PNI), and Ki-67 index. Seventeen females and 27 males were included, with the mean age of 65 years old, ranging from 36 to 89 years. The 5-year OS rate was 43% (mean 51 months, 95% confidence interval [CI] = 39-64). Significant prediction of a worse prognosis for 5-year OS rate was observed under univariate analysis for advanced T stage, positive margin, identified PNI, and higher Ki-67 index, respectively. Advanced T stage was confirmed to be an independent prognostic factor strongly affecting 5-year OS rate among this cohort of patients using a multivariate cox proportional hazard model. We found that clinicopathological parameters, especially postoperative pathological parameters, play a critical role in predicting the prognosis of ETBSCC patients.

Maximizing food equivalent unit yield for forage maize production without notably compromising dry matter yield and feed quality in a semi-arid region

Food equivalent unit (FEU) is a vector used to measure the value of food based on its calorie and protein content and their digestibility. However, the optimal planting density and N application rate for maximizing the FEU yield (FEUY) of forage maize (Zea mays L.) is still poorly understood in the fast-growing animal husbandry regions of the Chinese Loess Plateau. Here, a 2-year consecutive field experiment was conducted to explore the impacts of planting density, N application rate, and their interactions on growth, dry matter yield (DMY), forage quality, and FEUY of a dominant forage maize cultivar. Planting density significantly affected the stem diameter, LAI, DMY, and dry matter allocation (DMA) of the leaf. Initially, increasing the N rate increased the stem diameter, LAI, FEUY, and DMY of forage maize and then decreased. The stem diameter, LAI, FEUY and above-ground DMY peaked under 180 kg∙ha−1 N in both years. Moreover, N application significantly increased the crude protein content of the whole plant and decreased the acid detergent fiber content. The surface fittings of the 2-year study indicated that 110,000 plants∙ha−1 (plant density) and 171.2 kg∙ha−1 (N rate) obtained the greatest DMY (19.0 t∙ha−1). The grade index (a comprehensive evaluation index for forage quality) peaked at 15.4 MJ∙d−1 under 94,000 plants ha−1 and 270 kg∙ha−1. The 110,000 plants∙ha−1 plant density and 181.5 kg∙ha−1 N rate jointly maximized the FEUY (11,125.4 FEU∙ha−1), maintaining 99.9 % of the maximum DMY and 97.5 % of the maximum grade index. Thus, 110,000 plants∙ha−1 plant density and 181.5 kg∙ha−1 N rate are recommended for high-productivity forage maize production, without notably compromising dry matter yield and feed quality. This research is conducive to advancing the coordinated development of forage crop cultivation and herbivorous livestock farming in semi-arid rainfed areas.

Vibration of embedded restrained composite tube shafts with nonlocal and strain gradient effects

Torsional vibration response of a circular nanoshaft, which is restrained by the means of elastic springs at both ends, is a matter of great concern in the field of nano-/micromechanics. Hence, the complexities arising from the deformable boundary conditions present a formidable obstacle to the attainment of closed-form solutions. In this study, a general method is presented to calculate the torsional vibration frequencies of functionally graded porous tube nanoshafts under both deformable and rigid boundary conditions. Classical continuum theory, upgraded with nonlocal strain gradient elasticity theory, is employed to reformulate the partial differential equation of the nanoshaft. First, torsional vibration equation based on the nonlocal strain gradient theory is derived for functionally graded porous nanoshaft embedded in an elastic media via Hamilton’s principle. The ordinary differential equation is found by discretizing the partial differential equation with the separation of variables method. Then, Fourier sine series is used as the rotation function. The necessary Stokes' transformation is applied to establish the general eigenvalue problem including the different parameters. For the first time in the literature, a solution that can analyze the torsional vibration frequencies of functionally graded porous tube shafts embedded in an elastic media under general (elastic and rigid) boundary conditions on the basis of nonlocal strain gradient theory is presented in this study. The results obtained show that while the increase in the material length scale parameter, elastic media and spring stiffnesses increase the frequencies of nanoshafts, the increase in the nonlocal parameter and functionally grading index values decreases the frequencies of nanoshafts. The detailed effects of these parameters are discussed in the article.

Effects of heat wave propagation and initial stress on the thermo-elastic behavior of porous-auxetic FG circular plate with variable hybrid foundation

Engineering structures' heterogeneity and porous-auxetic features generate some prominent effects on their thermo-mechanical behavior. In addition, initial stress and heat wave propagation also play important roles in the mechanical behavior of FGM structures. Therefore, this paper investigates the effects of heat wave propagation and initial stress on the thermo-elastic behavior of porous-auxetic FG circular/annular plates with variable hybrid foundations. The one-dimensional transient hyperbolic heat conduction equation is modeled using the Cattaneo-Vernotte (C-V) theory and numerically solved using the Crank-sNicolson (C-N) finite difference scheme. Besides, a mathematical model of the other governing equations is extracted based on the classical thermoporoelasticity theory and semi-analytically solved by employing the state-space method and differential quadrature technique. Numerical examples are provided to illustrate the findings of this investigation graphically. The results reveal that the grading indices, and thermal relaxation time have a significant effect on heat wave propagation in the FG circular plate. Initial stress, porosity, and auxeticity also play an important role in its thermoelastic behavior.

On the maximization of entropy in the process of thermalization of highly multimode nonlinear beams.

We present a direct experimental confirmation of the maximization of entropy which accompanies the thermalization of a highly multimode light beam, upon its nonlinear propagation in standard graded-index (GRIN) optical fibers.

Hierarchical Gradient Structural Porous Metamaterial with Selective Spectral Response for Daytime Passive Radiative Cooling

AbstractPorous photonic structures have greatly advanced large‐scale radiative cooling application owing to its satisfying optical properties, easy‐designation, and low cost. However, current reported porous radiative cooling materials mainly focuses on uniform or random pore distribution structure, which failed to achieve precise spectrum control for sunlight and mid‐infrared light, thereby weakening the radiative cooling performance. Herein, gradient structural porous metamaterials (GSPMs) are proposed and successfully constructed for maximizing cooling effectiveness based on step‐by‐step freeze‐casting technology. The designed GSPMs with gradient micro‐nano porous structure can wide‐range scatter entire solar spectrum while possess gradual refractive index transition to increase air‐medium interface absorption at mid‐infrared regions. Notably, solar reflectivity and mid‐infrared emissivity of GSPMs reach 97.3% and 97.6%, achieving maxinum cooling temperature of 8.7 °C and net cooling power of 94.1 W m−2, presenting a higher cooling effect than random porous materials. Moreover, GSPMs enable achieve compatibility with color aesthetic and cooling superiorities due to selective spectra response behavior, as well as can be applied in building materials, realizing efficient energy saving and CO2 emission reduction. This work proposed gradient porous structure can achieve highly efficient daytime radiative cooling, offering new possibilities in the structure design of next‐generation porous radiative cooling materials.

Two-site microendoscopic imaging probe for simultaneous three-dimensional imaging at two anatomic locations in tissues.

Systems that can image in three dimensions at cellular resolution and across different locations within an organism may enable insights into complex biological processes, such as immune responses, for which a single location measurement may be insufficient. In this Letter, we describe an in vivo two-site imaging probe (TIP) that can simultaneously image two anatomic sites with a maximum separation of a few centimeters. The TIP consists of two identical bendable graded index (GRIN) lenses and is demonstrated by a two-photon two-color fluorescence imaging system. Each GRIN lens has a field of view of 162 × 162 × 170 µm3, a nominal numerical aperture of 0.5, a magnification of 0.7, and working distances of 0.2 mm in air for both ends. A blind linear unmixing algorithm is applied to suppress bleedthrough between channels. We use this system to successfully demonstrate two-site two-photon two-color imaging of two biomedically relevant samples, i.e., (1) a mixture of two autofluorescent anti-cancer drugs and (2) a live hybrid tumor consisting of two spectrally distinct fluorescent cell lines.

Coupled thermo-mechanical analysis of creep in a rotating FGMEE annular plate under complex thermal loading considering solar radiation, convection, and internal heat source

In this analysis, the creep responses of a non-constant thickness annular plate was presented. The material of disc is assumed functionally graded magneto-electro-elastic (FGMEE) in which the material properties change through the radius. Also, the heat transfer coefficients for convection and conduction are functions of radius and temperature. At first, the equation of heat transfer accounting for thermal gradient, convection boundary conditions, internal heat generation, and solar radiation effects was derived. The differential transformation method (DTM) was used to solve the resulting nonlinear differential equation. The equilibrium equation for the annular plate including creep strain effects was then obtained. Ignoring creep strains, an analytical solution was obtained for the zero-time of this equation. Then, creep strains were introduced using Norton's law and the Prandtl-Reuss relations to find the stress and strain rates under fixed temperature boundary conditions. Next, the equation of strain rates including creep strains was solved analytically. Finally, an iterative approach was used to evaluate the time-dependent redistribution of creep stresses at any time point. Numerical examples highlighted the influences of key parameters like internal heat generation, convective heat transfer, grading index, solar radiation, thickness profile, and angular speed on the stresses, deformations and electric and magnetic potentials.

Efficacy and Safety of Laser Therapy on Ischemic Central Retinal Vein Occlusion: A Systematic Review and Analysis of Clinical Studies.

Many studies have evaluated different treatments for ischemic central retinal vein occlusion (CRVO). Nevertheless, improvement and complication rates vary significantly. This systematic review aimed toevaluate the efficacy of laser therapy in treating ischemic CRVO compared with a control group using other treatments. The databases of PubMed,Google Scholar, and ClinicalTrials.gov were searched usingavarietyofkeywords, including"ischemic central retinal vein occlusion," "CRVO," "laser," and "panretinal photocoagulation." After data extraction, each study's quality was assessed using the methodological index for nonrandomized studies (MINORS) or grading of recommendations, assessment, development, and evaluation or GRADE standards. A sum of 195 abstracts were reviewed,andseven clinicaltrials were eventually chosen. Of these, four were prospective studies, two were randomized controlled studies, and only one was a retrospective study. The assessment of potential biases in our included studies revealed that all these studies demonstrated moderate or high quality. Two studies were selected for meta-analysis, and the results showed no significant difference in visual acuity (VA) outcomes between the treated and the control groups (P = 0.17). In the remaining five studies, laser therapy was found to be more effective at neovascular complications, with a higher rate of neovascular glaucoma (NVG), iris neovascularization (NVI), neovascularisation at disc (NVD), and retinal neovascularization in the group without laser treatments. This review suggests that laser therapy is essential in preventing neovascular complications, such as NVG, NVI, NVD, and retinal neovascularization rather than improving VA. In addition, the combination of laser photocoagulation and intravitreal injection (IVI) improved VA, but further studies are required.

Impact of treatment setting on survival outcomes in undifferentiated pancreatic carcinoma: An analysis of the National Cancer Database.

e16333 Background: Undifferentiated carcinoma of the pancreas is a rare and highly aggressive form of pancreatic cancer, characterized by its low degree of cellular differentiation. The prognosis for this condition remains poor, with median survival times typically not exceeding one year. While existing research indicates that treatment at academic institutions may lead to improved survival outcomes compared to non-academic settings, there is scant research on this topic in the context of undifferentiated carcinoma of the pancreas. Addressing this research gap, this study analyzes data from the National Cancer Database (NCDB) to compare long-term survival rates between patients treated at academic institutions and those at other facilities. Methods: The National Cancer Database (NCDB) was used to identify patients diagnosed with undifferentiated carcinoma of the pancreas from 2004 to 2019 using the histology code 8020 as assigned by the Commission on Cancer Accreditation program. Kaplan-Meier, ANOVA, and Chi-Square tests were performed. Data was analyzed using SPSS version 27 and statistical significance was set at α = 0.05. Results: In this analysis of 284 patients, 124 (43.7%) received care at academic centers, while 160 (56.3%) were treated at non-academic institutions. Individuals treated at academic centers had a significantly extended mean overall survival of 27 months compared to 13.9 months for those treated elsewhere (p &lt; 0.05). Additionally, patients at academic centers were more likely to be insured, undergo surgical interventions, receive chemotherapy, and be initially diagnosed at a different facility (p &lt; 0.05). Conversely, patients at non-academic centers were more likely to be white, live closer to their care facility, and exhibit greater metastatic regional lymph nodes (p &lt; 0.05). However, there was no significant association between treatment at academic centers and variables such as median income, cancer grade, and Charlson-Deyo Comorbidity Index (CDCI) (p &gt; 0.05). Conclusions: This study revealed that individuals with undifferentiated carcinoma of the pancreas receiving treatment at academic centers exhibit a significantly improved overall survival rate compared to those treated at non-academic centers. This disparity in survival rates might be attributed to the higher prevalence of chemotherapeutic treatments and surgical interventions at academic institutions. While these observations are based on correlational data, they underscore the necessity for further investigation to establish causality.

Combined NF2/PTEN mutations as predictors of meningioma aggressiveness.

e14044 Background: In meningiomas, loss of the NF2 tumor suppressor gene function leads to dysregulation of cell proliferation and tumor formation. PTEN, another tumor suppressor gene correlated with worse prognosis in tumors like gliomas, has also been reported in meningiomas, but the impact of its mutation alone or in conjunction with NF2 loss on outcomes in these tumors is unexplored. We aimed to evaluate whether dual NF2/PTEN mutations comprise a more aggressive meningioma phenotype compared to tumors with only NF2 mutations. Identifying this high-risk genetic profile could allow for preventative and individualized treatment of these aggressive meningiomas. Methods: We reviewed patients who underwent meningioma resection at our institution from January 2018 through October 2022. Demographic information, tumor characteristics, pre- and post-operative clinical characteristics, and outcomes were collected. Meningioma specimens were analyzed by immunohistochemistry for WHO grading and Ki67 proliferation index and by sequencing for genomic alterations. We performed multivariable logistic regression analyses to identify clinical outcomes associated with proliferation index and genetic mutations. Results: We identified NF2 mutations in 24 meningiomas and dual NF2/PTEN mutations in 7 meningiomas. Mutation rates did not significantly differ based on demographic factors including sex, age, race, socioeconomic status, or prior cranial radiation status (p&gt;0.05). The majority of tumors with these mutations (93%) were in non-skull base regions (i.e. convexity, parafalcine). Tumors with both NF2 and PTEN mutations were more likely to be WHO grade III tumors than those with the NF2 mutation alone (29% versus 9%). Tumors with dual mutations had higher likelihood of having Ki67 proliferation indices ≥ 10% (OR 5.98, p&lt;0.01). While higher Ki67 index was significantly associated with features of more aggressive tumors including higher WHO grade and recurrence rates, dual mutation in NF2 and PTEN is associated with higher rate of recurrence (OR 13.13, p&lt;0.001) and mortality (OR 5.14, p&lt;0.05) compared to NF2 irrespective of Ki67 index. Notably, patients with mutations in NF2 alone or both NF2/PTEN did not differ in preoperative Karnofsky performance score, Simpson resection grade, or presence of post operative residual tumor. Conclusions: Our results demonstrated that concomitant NF2 and PTEN mutations in meningiomas were associated with higher WHO grades, tumor proliferation indices, recurrence rates, and mortality rates. This finding suggests that NF2/PTEN mutated meningiomas represent a distinct subset of tumors that demonstrate a more aggressive clinical and histopathological phenotype that may require more aggressive treatment and closer surveillance. Further investigation is warranted to confirm the prognostic relevance of NF2/PTEN mutations in meningioma and elucidate their underlying molecular mechanisms.

Low-loss, compact, fibre-integrated cell for quantum memories

We present a low-loss, compact, hollow core optical fibre (HCF) cell integrated with single mode fibre (SMF). The cell is designed to be filled with atomic vapour and used as a component in photonic quantum technologies, with applications in quantum memory and optical switching. We achieve a total insertion loss of 0.6(2) dB at 780 nm wavelength via graded index fibre to ensure efficient mode matching coupled with anti-reflection coatings to minimise loss at the SMF-HCF interfaces. We also present numerical modelling of these interfaces, which can be undertaken efficiently without the need for finite element simulation. We encapsulate the HCF core by coupling to the SMF inside a support capillary, enhancing durability and facilitating seamless integration into existing fibre platforms.

Twist detection Mach-Zehnder interferometer based on optical vernier effect and its phase demodulation system

Fiber interferometric sensor can achieve sensing enhancement of various physical quantities based on the optical vernier effect, but there are currently no proposed torsion detection enhancement schemes. In this paper, we control the number of cladding modes in the sensing single-mode fiber by graded index fiber collimator and form a dual beam interference with the core mode, resulting in a transmission spectrum with regular waveform. The experimental results indicate that the sensing Mach-Zehnder interferometer (MZI) has a torsional sensitivity of −0.014 nm/(rad/m) within a large detection range of 0–60 rad/m. After amplification by optical cursor effect, it reaches −0.361 nm/(rad/m) with an amplification factor of 25.8 times, the detection limit for envelope valley is 0.345 rad/m. The sensor has a relatively small response to other physical quantities, with a strain sensitivity of 20.4 pm/με, a temperature sensitivity of 1.792 nm/℃, and a refractive index sensitivity of 77.885 nm/RIU, exhibiting excellent anti refractive index crosstalk performance. In addition, we discuss the phase demodulation scheme for interferometric sensor based on optical vernier effect sensitivity enhancement for the first time, which can filter out noise caused by dispersion or loss, eliminate the influence of the initial phase of the sensing system, and evaluate the direction of improving the detection performance of the phase demodulation system.

Trioctylphosphine oxide-based hydrophobic magnetic deep eutectic solvent as a novel extractant for the enrichment of primary aromatic amines from juice and environmental water

In this study, a novel technique utilizing vortex-assisted dispersive liquid-liquid microextraction with magnetic deep eutectic solvents (MDESs) was established and coupled with HPLC-UV to analyze six primary aromatic amines (PAAs). A novel hydrophobic MDES prepared from trioctylphosphine oxide, octanol, and CoCl2 was used as the extractant, which could be dispersed uniformly during extraction, then floated onto the sample surface and re-aggregated into a single drop spontaneously after the extraction. The variables influencing the efficiency of the extraction process were investigated. When performing under the optimal extraction conditions, this method exhibited excellent linearity, low limits of detection (0.2–0.9 ng mL−1), and high precision (RSD ≤ 8.3 %). The enrichment factors ranged from 56 to 182. Satisfactory recoveries in the range of 91.6–109.2 % with RSDs < 7.1 % were obtained from three apple juices and three environmental water samples. The greenness and practicality of the developed method were assessed by AGREE, AGREEprep, and blue applicability grade index metric tools. Overall, the established procedure demonstrated its simplicity, speediness, environmental friendliness, and effectiveness in analyzing PAAs from aqueous matrices.

Study on the Effect of Asphalt Static Conditions on the Tensile Properties of Acidic Aggregate Hydraulic Asphalt Concrete.

Hydraulic asphalt concrete is known for its excellent seepage control performance and strong deformation resistance. This engineering material has widespread applications in the seepage control structures of hydraulic buildings. Recent projects have investigated the use of acidic aggregates to improve economic efficiency. However, they have also highlighted the weaker adhesion between acidic aggregates and asphalt, which necessitates stringent construction process control. This study investigates the impact of resting conditions on the tensile properties of acidic aggregate hydraulic asphalt concrete. The results of the tensile testing indicate that the storage time significantly affects the performance of asphalt concrete. The tensile strength of the specimens without anti-stripping agents decreased from 1.711 MPa to 0.914 MPa after resting periods of 0, 10, 20, and 30 days. The specimens treated with anti-stripping agents also showed a decrease in tensile strength over time, similar to the trend observed in the previous specimens. Digital specimen simulations indicated a decrease in cohesion between the asphalt and the aggregate from 5.375 MPa to 2.664 MPa after 30 days, representing a reduction of 50.44%. To counteract the effect of the storage time on the bonding between acidic aggregates and asphalt, this study recommends reducing the grading index and maximum size of aggregates, decreasing the coarse aggregate content, and selecting smooth aggregate shapes.

Estimating nitroxynil residues in food samples and surface water using two different sustainable chemical sensing techniques: Comparative greenness, whiteness, and blueness study

The presence of veterinary drug residues in edible animal tissues endangers human health and safety, accordingly, global nations enacted legislative restrictions to monitor their concentrations in food. In this work, we introduce two fluorimetric sensors for determining nitroxynil (NXL), a crucial veterinary medication, in various matrices. Sensor I, novel nitrogen and sulfur-doped carbon quantum dots (S,N-CQDs), was fabricated from strawberry and leek juices as cheap and sustainable natural resources. Only five minutes of microwave radiation were required as a rapid synthesizing technique without any drastic conditions or organic solvents. The S,N-CQDs manifest blue emission using λex/em of 340/418 nm. The synthesized nanosensor was characterized using UV Spectroscopy, transmission electron microscopy (TEM), and Fourier-transform infrared spectrometry (FTIR). Sensor II was the acriflavine reagent (AV) that exhibits native fluorescence using λex/em of 265/505 nm. Both sensors displayed quantitative turning off in their native fluorescence by increasing concentrations of NXL (1.0–10.0 and 0.5–8.0 µg mL−1) with correlation coefficients r = 0.9998 and 0.9999 for sensors I and II, respectively. The two probes achieved satisfactory percentage recoveries and standard deviation (SD < 4) for NXL assessing in complex matrices of diverse food samples (bovine muscle, kidney, and fat) and Fasciolar® veterinary formulation. Additionally, they have been successfully used to detect the investigated drug in river ecosystems with a mean %recovery of 100.10 ± 1.70, and 99.95 ± 1.31 for sensors I and II, respectively. The two constructed sensors’ specificity has been confirmed for all tested matrices reflecting their feasibility as promising platforms in therapeutic drug monitoring, livestock ecosystems, food safety assurance, quality control of drugs, and environmental pollution monitoring. Quenching mechanisms for both methodologies were studied and the reaction stoichiometry for NXL − AV complex was calculated in two ways. Lastly, a comprehensive comparison was performed between the suggested methodologies and published fluorimetric works. The greenness feature was assessed by the Analytical Eco-scale (AES), Green Analytical Procedure Index (GAPI), and Analytical GREEnness Metric Approach (AGREE). In addition, white analytical chemistry principles were checked to assess sustainability criteria using the RGB 12 algorithm. The recently launched Blue Applicability Grade Index (BAGI) metric tool was also employed to assess the practicality (Blueness) character.