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Validation of an Reverse phase high performance liquid chromatography Method for <i>In Vitro</i> Quantification and Degradation Analysis of Naphthol AS-E Phosphate in Bulk Drugs and Nanoparticles.
No full textThis study presents the first validated High-performance liquid chromatography (HPLC) technique for quantifying naphthol AS-E phosphate (NASEP) in bulk drugs and nanoparticle formulation. A C18 HPLC cartridge (250 × 4.6 mm, 5 µm particle size) served as the stationary phase for quantification. The mobile phase consisted of Milli-Q water with 0.1% trifluoroacetic acid (TFA) in pump A and acetonitrile with 0.1% TFA in pump B, with a flow rate ranging from 0.8 to 1.2 mL/min. A 32 factorial design was employed to evaluate the robustness of the proposed method, using mobile phase composition (X1), flow rate (X2), and column temperature (X3) as independent variables and peak area (R1), retention time (R2), and percent recovery (R3) as response variables. The calibration range curve (10-500 µg/mL) was best fitted by quadratic regression. The linearity was reported in the above-mentioned range. The accuracy was 99.952% ± 0.961% at the 75% level, 99.58% ± 1.483% at the 100% level, and 99.789% ± 1.936% at the 125% level. The coefficient of variation was below 2% for both intraday and interday measurements, and the limits of detection and quantification were 0.038 and 0.115 µg/mL, respectively. The NASEP solution was stable (99.04% ± 0.0251%) for 48 h at 8°C. The forced degradation study also revealed that the NASEP solution remained stable in an acidic environment for 48 h at 40°C but degraded at 80°C (p p < 0.039). Furthermore, NASEP encapsulated in a Gly-Arg-Gly-Asp-Ser pentapeptide and low-molecular-weight heparin functionalized metal-organic framework exhibited sustained drug release at acidic pH 5.4. The proposed NASEP quantification method was validated and is suitable for routine analysis in pharmaceutical formulations.</i
Small organic fluorophores with SWIR emission detectable beyond 1300 nm.
No full text3,6-Dimethylamino fluorenone was functionalized with substituents to achieve an absorption maximum at 1012 nm and emission >1300 nm. TD-DFT calculations confirmed that the substituent orbitals contribute to narrowing the HOMO-LUMO energy gap. Imaging with an InGaAs-based SWIR camera and various longpass filters confirmed detection >1300 nm.S. B. gratefully acknowledges the financial support from the Central Innovation for SMEs (ZIM) of the German Federal
Ministry for Economic Affairs and Climate Action (BMWK). Help from Amir Gizatullin (KCC, KAUST) is gratefully acknowledged for providing 5b. O. T. B. acknowledges funding from Helmholtz Zentrum Mu¨nchen core funding, National Center for Tumor Diseases (NCT) core funding, Deutsche For schungsgemeinschaft (DFG) Emmy Noether program no. BR 5355/2-1, German Federal Ministry of Education and Research (BMBF) project BetterView, Helmholtz Imaging Project grant ZT-I-PF-4- 038, Chan Zuckerberg Initiative (CZI) Deep Tissue Imaging grants DTI-0000000248 and DTI2-0000000206, and Deutsche For schungsgemeinschaft (DFG) SFB1123-B10
Microfluidic study of CO2 diffusive leakage through microfractures in saline aquifers for CO2 sequestration
No full textCO2 diffusive leakage, or diffusive transport, through intrinsic or induced caprock fractures poses a significant concern for the security of CO2 sequestration in saline aquifers. Although this issue has garnered considerable interest and has been the subject of many numerical analyses, experimental studies remain limited. We present the first experimental investigation of CO2 diffusive leakage through microfractures in a generalized microfluidic system that represents the key features of the system under realistic CO2 sequestration conditions. Our findings reveal two-stage depletion kinetics of trapped CO2 in porous media, driven by dissolution and diffusion through fractures. The first stage is characterized by the rapid dissolution of CO2 into nearby brine, while the second stage exhibits a steady leakage rate as CO2 diffuses through the fractures into a water sink, driven by the solubility limit, assuming stable microfracture structures and negligible advection. Between these two stages, there is a transition period during which CO2 saturation remains stable. Two key parameters are proposed to quantify the diffusive leakage process: the transition time and the steady-state leakage rate. The transition time 0.1[Formula presented] defines the timescale for the onset of a diffusive leakage event, where l represents the fracture length and D the gas diffusivity. The steady-state leakage rate is primarily governed by aquifer conditions and fracture properties, which scales as [Formula presented], where C1 is the solubility limit. Our theoretical predictions align well with the experimental results. Additionally, the effects of temperature, pressure, salinity, and storage depth on CO2 diffusivity and solubility are explored through sensitivity analysis. Despite the simplifications in our experimental design and modeling, our study lays the foundation for future research by progressively incorporating additional complexities. These findings provide broader implications for assessing leakage risks in subsurface geological gas storage, such as H2 and CH4.We thank Saudi Aramco for funding this research under project number CIPR 2358. We thank Dr. Xu Liu for his assistance in establishing the mass transfer model. We also extend our gratitude to Dr. Yafei Chen and Prof. Zhengwei Pan for their valuable advice on the experimental design
Chemical kinetics uncertainty quantification on the dynamic detonation parameters for hydrogen–air mixtures
No full textThis study aims at (i) presenting detail reaction kinetics and corresponding reduced model which include nitrogen species chemistry for conditions relevant to H
-air detonations, (ii) based on the obtained kinetics, conducting the quantification of the uncertainty induced by the uncertainty of the rate constants on the dynamic detonation parameters (DDP) predicted using various semi-empirical and theoretical models, and (iii) investigating the impact of the induction length uncertainty on the 2-D detonation simulations. To achieve the first goal, a total of 72 detailed reaction models were compiled and quantitatively evaluated based on (a) shock tube ignition delay-time (
) data under detonation-relevant conditions in H
-O
-diluent(-nitrogen oxide) mixtures, and (b) DDP data. The two evaluation approaches lead to the selection of two different reaction models. For both selected mechanisms, a Monte Carlo method was adopted to statistically identify the uncertainty on the dynamic detonation parameters induced by the uncertainty of rate constants. Reactions R1: H+O
=OH +O and R2: H+O
(+M)=HO
(+M) were shown to induce the largest uncertainty on the predicted DDP for initial conditions of 300 K and 101 kPa. Furthermore, the uncertainty bands of cell size for a range of equivalence ratios obtained by perturbing R1 and R2 were illustrated. The distribution type of the DDP induced by sampling the rate constant
was investigated. To estimate the maximum possible uncertainty of cell size induced from rate constants, two extreme mechanisms were developed by perturbing the rate constants to their 3
limits. For a stoichiometric mixture, these extreme mechanisms present a variation of the induction zone length by a factor of 15, which results in a change in the predicted cell size by 10.7 times. The difference in cell size can be even larger for off-stoichiometric mixtures. Concerning the third goal of the current study, we varied the rate constant of H+O
=H+OH, the most sensitive reaction for the induction length, to its 3
limits to study the corresponding influence in 2-D unsteady simulations characteristics, i.e., soot foil, shock velocity profile, and temperature field, for a stoichiometric hydrogen–air mixture. A reduced mechanism was developed based on the selected kinetics to minimize the computational cost related to 2-D simulations. An average cell size 2.08 times larger was obtained when using the model with the -3
perturbation on R1 rather than when using the model with the +3
perturbation. Our results demonstrate that the uncertainties on the rate constants constitute an essential aspect to consider for DDP prediction and cell size prediction in 2-D unsteady simulation.This work was partly supported by the King Abdullah University of Science and Technology , through the contract number OSR-2022-CCF-1975.49. JMG acknowledges the computational resources provided by the CURTA cluster of MCIA (Mesocenter for Intensive Calculation in the Aquitaine French region) in which the 2-D simulations were carried out. The authors are grateful to the reviewers for their thorough and constructive comments
Fractionation by persistent random walk and two-component diffusion law
No full textRandom movement of microscopic particles in heterogeneous environments leads to fractionation phenomena, with the Soret effect being one of the most representative examples. This raises a fundamental question: what characteristics of random movement give rise to such fractionation phenomena? We investigate whether the persistence of a random-walk system has such a property and show that fractionation occurs only when the persistence is anisotropic. This is shown by investigating the convergence of a heterogeneous persistence random-walk system to a resulting anisotropic diffusion equation. Numerical simulations of the diffusion equation are compared with a Monte Carlo method and solutions to the recursive relations.The first author was supported by King Abdullah University of Science and Technology, Saudi Arabia baseline funds. The second and third authors were supported by the National Research Foundation of Korea, South Korea (RS-2024-00347311)
CCDC 2389632: Experimental Crystal Structure Determination : catena-[(mu-iodo)-(pyridine)-copper(i)]
No full textAn entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
Extreme Surface Ozone Episodes over the Arabian Gulf and their Relationship with Meteorological Conditions
No full textIn this study, we investigated the seasonal distribution of extreme surface ozone (O3) episodes in association with meteorological conditions over the Arabian Gulf (AG) between 2016 and 2019. We used hourly surface O3 measurements from the United States Embassy in Manama and air temperature observations from the Iowa Environmental Mesonet. We computed the maximum daily 8-h average of O3 using the Air Quality Index methodology. The results showed that the air quality in Manama can be categorized as “good,” “moderate,” “unhealthy for sensitive groups,” “unhealthy,” and “very unhealthy” for 45.31 %, 20.61 %, 19.08 %, 11.63 %, and 3.37 % of the time, respectively. The extreme days, defined as days with MDA8-O3 ≥ 86 ppb, occurred 72.11 % in summer, 15.65 % in fall, 12.24 % in spring. No extremes were recorded in winter. Our analysis of surface O3 values obtained from the Copernicus Atmosphere Monitoring Service showed that the O3 levels during summer extremes were higher by 10 ppb than their climatological mean. We then categorized the O3 summer extremes into single-day episodes (SDEs) and multi-day episodes (MDEs), revealing that most of the extremes (73.58 %) were MDEs. An analysis of meteorological conditions using the fifth-generation atmospheric reanalysis from the European Centre for Medium-Range Weather Forecasts, MODIS-Terra, and the Clouds and the Earth's Radiant Energy System database revealed that the MDEs exhibit increased temperatures, temperature subsidence form the mid-troposphere, weakened wind speeds, low aerosol optical depth, and increased insolation. These conditions are less pronounced during SDEs. Moreover, 5.67 % of the summer extremes were associated with stratospheric intrusions.This study was funded by the office of the Vice President of Research at King Abdullah University of Science and Technology (KAUST). The ground-based O observations were provided by the United States Embassy in Manama, Bahrain (https://www.airnow.gov/international/us-embassies-and-consulates/#Bahrain$Manama). The air temperature observations in Bahrain from the Iowa Environmental Mesonet can be accessed at: https://mesonet.agron.iastate.edu/request/download.phtml?network=BH__ASOS. The ERA5 reanalysis was obtained from the European Centre for Medium-Range Weather Forecasts (https://cds.climate.copernicus.eu/#!/home). The aerosol optical depth (AOD) was provided by MODIS-Level 2 Deep Blue Aerosol products, and can be accessed on the LAADS-DAAC website (https://ladsweb.modaps.eosdis.nasa.gov/search/order/1/MOD04_L2--61,MYD04_L2--61v). The shortwave solar radiation at the surface was provided by CERES downloaded from the NASA website (https://ceres.larc.nasa.gov/data/). The authors gratefully acknowledge the National Oceanic and Atmospheric Administration Air Resources Laboratory for the provision of the HYSPLIT transport and dispersion model, which can be accessed through the Real-time Environmental Applications and Display sYstem (https://www.ready.noaa.gov/HYSPLIT.php)
Thymoquinol-2-<i>O</i>-<i>β</i>-D-glucopyranoside: Isolation from <i>Pulicaria Jaubertii</i>, Anticancer Efficacy, and Comparative Apoptotic Markers Binding Studies with Thymoquinone and Thymoquinol
No full textThymoquinol-2-O-β-D-glucopyranoside (Th-Ol-G) isolated from Pulicaria jaubertii was characterized by 1D-(1H, 13C, DEPT) and 2D-(COSY, HSQC, HMBC) NMR analyses. This study provides new findings for the anticancer activity of Th-Ol-G and compares its silico binding affinity to caspases 3 and 9 with its corresponding aglycones, thymoquinone (Th-One) and thymoquinol (Th-Ol). Th-Ol-G has exerted marked cytotoxicity against HCT-116 and HeLa cells (IC50 = 13 ± 1.2 and 12 ± 0.6 µg/mL, respectively), compared to its effect on the noncarcinogenic HEK-293 cell (IC50 value of 22 ± 1.3 µg/mL). Th-Ol-G induced apoptosis in cancer cells evident by significant shrinkage of nuclei in DAPI-stained cells compared to control. Th-Ol-G markedly increased the expression of apoptotic markers, caspases 3 and 9 in HeLa and HCT-116 cells compared to untreated cells. Th-Ol-G has demonstrated a marked lower docking score of −8.8 and −6.3 kcal/mol compared to Th-One (−3.8 and −3.2 kcal/mol) and Th-Ol (−4.0 and −4.2 kcal/mol) with MM-GBSA binding free energy values of −49.1 and −26.3 kcal/mol for caspase 3 and 9, respectively. Theoretical findings suggest that Th-Ol-G exhibits stability and strong binding to both enzymes, with the sugar moiety engaging in H-bonding with the enzyme's amino acids. Additionally, conformational changes in caspase 9′s binding cavity indicate Th-Ol-G's stable interaction with the protein.All authors contributed equally. Authors thank the infrastructural facilities and institutional support provided by Al-Azhar University, Qassim University, KAUST, and Imam Abdulrahman Bin Faisal University
Rheological and tectonic implications of eastern Tibet: Insights from early aftershock sequences driven by afterslip following three 2021-2022 moderate-large events
No full textEarly aftershock sequences and afterslip provide key insights into crust rheology and the triggering mechanisms of seismicity sequences. Three recent moderate-large strike-slip earthquakes in eastern Tibet, including the 2021 Yangbi Mw 6.1, the 2021 Maduo Mw 7.4, and the 2022 Menyuan Mw 6.4 events, provide an ideal opportunity to investigate the driving processes of aftershocks and the regional crustal rheology. In this study, we inverted for the early afterslip and statistically analyzed the spatiotemporal evolution of these three aftershock sequences. Our results reveal a significant spatial complementarity between the relocated aftershocks, coseismic slip and early afterslip, suggesting aftershocks were triggered by afterslip driven by the coseismic stress changes. The depth of the aftershock sequences consistently shallows over time, which we interpret as a transient response of the brittle-ductile transition zone to early postseismic relaxation. For the first time, we quantify the depth-dependent variations of aftershock-derived rheological and frictional parameters along these three strike-slip faults in eastern Tibet. The recurrence times derived from early aftershocks are generally shorter than those estimated from geodetic or geological data, demonstrating that fault loading rates are not constant throughout the seismic cycle. This spatiotemporal comparison between aftershocks, coseismic slip and afterslip allows for the discrimination of different aftershock driving mechanisms. The framework presented here is generalized to other similar tectonic settings, providing a method to identify the dominant aftershock driving mechanism and to constrain the rheological properties, frictional parameters and recurrence times of regular earthquakes.We would like to extend our sincere thanks Sigurjón Jónsson, Yuan Gao, Zhuo Xiao, Xiaoning Su, Gaohua Zhu, Dezheng Zhao, Yaozong Zhou, Lei Zhao and Zilong He for their valuable suggestions, data sharing and communications during the development of this work. We acknowledge Crustal Movement Observation Network of China (CMONOC) for providing GNSS data at station QHME (https://data.earthquake.cn/datashare/report.shtml?PAGEID = siteInfo_jizhun). The GNSS postseismic data at station QHMD and H204 are available from Su et al., (2022) and Zhang et al., (2021a), respectively. The three aftershocks catalogues used in this study are respectively available from (Fan et al., 2022; Wang et al., 2021; Yang et al., 2021). The background seismicity catalogues for northeastern Tibet and southeastern Tibet is available from Xiao and Gao (2016) and Zhang et al., (2021b), respectively. Raw InSAR data are freely available (https://browser.dataspace.copernicus.eu/). This work was supported by the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Independent Research Project (SKLGP2024Z016), the National Natural Science Foundation of China (No. 42174023), Sichuan Province Science Fund (No. 2024NSFSC0802). The figures were prepared using the Generic Mapping Tools software (https://www.generic-mapping-tools.org/) and the MATLAB software (https://www.mathworks.com/products/matlab.html)
Comparative Effects of Superhydrophobic Sand and Plastic Mulches on Growth and Yield of Sweet Pepper (Capsicum annum L.) under Arid Environments
No full textSuperhydrophobic sand (SHS) is a plastic-free mulching technology that reduces surface evaporation of water from irrigated soils. Here, we present the results of two experimental field trials conducted in the 2019–20 and 2021–22 cropping seasons, comparing the efficacy of SHS with those of traditional plastic mulches on the growth and yield performance of sweet pepper (Capsicum annum L.) plants. The experiments were conducted at the King Abdulaziz University (KAU) agriculture research station at Hada Al-Sham (21˚48′3″N, 39˚43′25″E), Al-Jamoom, Saudi Arabia. The effects of bare soil (i.e., control treatment), 5 mm SHS thickness, and 10 mm SHS thickness, along with white and black plastic mulches (120-μm-thick polyethylene) were recorded on the plants via a randomized complete block design with three replicate plots. We found significant benefits of all of the mulches during the 2021–22 season, as evidenced by 51% (P < 0.001), 31% (P = 0.0102), and 32% (P = 0.0048) more fruits for the 10-mm SHS, white plastic, and black plastic mulches, respectively, compared with the unmulched controls. Consequently, the total fruit yield per plant increased by 112% (P = 0.000), 71% (P < 0.001), and 83% (P < 0.001), under 10 mm SHS, white plastic, and black plastic mulches, respectively. Curiously, the field trial conducted in 2019 in an adjacent field did not reveal significant benefits of SHS, which we attribute partially to erratic rain showers and field heterogeneity. Taken together, this study and our previous work show that 10-mm-thick SHS mulch is optimal for boosting irrigation efficiency in regions where water is a limiting factor. Unlike plastic mulches, SHS biodegrades in <1 year and becomes a part of the sandy soil matrix, thereby obviating landfilling. Thus, the benefits of SHS exceed those of plastic mulches in terms of closing the yield gap and carbon footprint. These findings underscore the potential of SHS as a sustainable solution for growing plants in hot and dry arid regions in Saudi Arabia and globally.This work was funded by KAUST and KAU through KAUST-KAU Collaborative Research Grant numbers REP/1/3908-01-01 (KAUST) to H.M. and JP–19–004 (KAU) to M.A.A.M. We gratefully acknowledge funding from King Abdallah University of Science and Technology (KAUST), Thuwal and King Abdulaziz University (KAU), Jeddah, under grant numbers REP/1/ 3908-01-01 (KAUST) to H.M. and JP–19–004 (KAU) to M.A.A.M. K.O. thanks Mr. Amin Haider for his assistance in SHS processing and logistic support. H.M. and A.G. have been issued a USPTO patent #11,497,177B2 on 11/15/2022. https://patents.google.com/patent/WO2018091986A1/en