Application of Machine Learning in Nanotoxicology: A Critical Review and Perspective.

The massive production and application of nanomaterials (NMs) have raised concerns about the potential adverse effects of NMs on human health and the environment. Evaluating the adverse effects of NMs by laboratory methods is expensive, time-consuming, and often fails to keep pace with the invention of new materials. Therefore, in silico methods that utilize machine learning techniques to predict the toxicity potentials of NMs are a promising alternative approach if regulatory confidence in them can be enhanced. Previous reviews and regulatory OECD guidance documents have discussed in detail how to build an in silico predictive model for NMs. Nevertheless, there is still room for improvement in addressing the ways to enhance the model representativeness and performance from different angles, such as data set curation, descriptor selection, task type (classification/regression), algorithm choice, and model evaluation (internal and external validation, applicability domain, and mechanistic interpretation, which is key to ensuring stakeholder confidence). This review explores how to build better predictive models; the current state of the art is analyzed via a statistical evaluation of literature, while the challenges faced and future perspectives are summarized. Moreover, a recommended workflow and best practices are provided to help in developing more predictive, reliable, and interpretable models that can assist risk assessment as well as safe-by-design development of NMs.

Selenium (Se) plays a key role in the biological effects of some viruses: Implications for COVID-19.

Host nutrition is an important factor affecting disease progression. Selenium (Se) is an essential trace element for the human body with anti-inflammatory, antioxidant, and immune effects, and Se deficiency increases RNA-virus replication and virulent mutations, which lead to more severe tissue damage and symptoms. Low Se status in the host may be an important cause of health complications induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this article, we describe the metabolic mechanisms by which Se is involved in anti-inflammatory, antioxidant, and immune effects, and review the role and clinical effects of Se in viral infection. We then discuss the potential relationship between Se and coronavirus disease 2019 (COVID-19). The association between soil Se level and the incidence of COVID-19 was observed in different cities of Hubei Province. The incidence of COVID-19 was more than 10 times lower in Se-enriched cities (Enshi, Shiyan, and Xiangyang) than in Se-deficient cities (Suizhou and Xiaogan). Although the relationship between soil Se levels and the incidence of COVID-19 in Hubei still needs further study, these findings provide baseline information demonstrating the effect of Se levels on SARS-CoV-2, which could contribute to the prevention and management of COVID-19.

Cysteine-enhanced reductive degradation of nitrobenzene using nano-sized zero-valent iron by accelerated electron transfer.

As an aliphatic amino acid, cysteine (CYS) is diffuse in the living cells of plants and animals. However, little is known of its role in the reactivity of nano-sized zero-valent iron (NZVI) in the degradation of pollutants. This study shows that the introduction of CYS to the NZVI system can help improve the efficiency of reduction, with 30% more efficient degradation and a reaction rate constant nine times higher when nitrobenzene (NB) is used as probe compound. The rates of degradation of NB were positively correlated with the range of concentrations of CYS from 0 to 10 mmol/L. The introduction of CYS increased the maximum concentration of Fe(III) by 12 times and that of Fe(II) by four times in this system. A comparison of systems featuring only CYS or Fe(II) showed that the direct reduction of NB was not the main factor influencing its CYS-stimulated removal. The reduction in the concentration of CYS was accompanied by the generation of cystine (CY, the oxidized form of cysteine), and both eventually became stable. The introduction of CY also enhanced NB degradation due to NZVI, accompanied by the regeneration of CYS. This supports the claim that CYS can accelerate electron transfer from NZVI to NB, thus enhancing the efficiency of degradation of NB.

Structure-Oriented Research on the Antiestrogenic Effect of Organophosphate Esters and the Potential Mechanism.

Organophosphate esters (OPEs) can exhibit various toxicities including endocrine disruption activity. Unfortunately, the low-dose endocrine-disrupting effects mediated by estrogen receptors (ERs) are commonly underestimated for OPEs and their metabolites. Here, structure-oriented research was performed to investigate the estrogenic/antiestrogenic effect of 13 OPEs (including three metabolites) and the potential mechanism. All of the OPEs exerted antiestrogenic activities in both E-screen and MVLN assays. OPEs with bulky substituents, such as phenyl rings (triphenyl phosphate (TPP), tricresyl phosphate (TCP), diphenylphosphoryl chloride, and diphenylphosphite) or relatively long alkyl chains (dibutylbutylphosphonate (DBBP)), exerted relatively strong ER antagonism potency at micromolar concentrations. The established quantitative structure-activity relationship indicated that the antiestrogenic activities of the OPEs mainly depended on the volume, leading eigenvalue, and hydrophobicity of the molecule. Molecular docking revealed that the three OPEs with the bulkiest substituents on the phosphate ester group (TPP, TCP, and DBBP) have a similar interaction mode to the classical ER antagonist 4-hydroxytamoxifen. The correlation between the antiestrogenic activity and the corresponding ER binding affinity was statistically significant, strongly suggesting that the OPEs possess the classical antagonism mechanism of interfering with the positioning of helix 12 in the ER.

Screening the main factors affecting phthalate esters adsorption on soils, humic acid, and clay organo-mineral complexes.

Phthalate esters (PAEs) are one of the most frequently detected organic pollutants in soils. In this work, the adsorption behaviors of di-ethyl phthalate (DEP) and dibutyl phthalate (DBP) on soils, humins (HM) and Clay organo-mineral complexes (Clay-OM) from four regions in China, Changchun (CC), Cangzhou (CZ), Yinchuan (YC), and Changsha (CS) were studied. The surface and structural properties of these sorbents were characterized using Brunauer-Emmett-Teller specific surface area, Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy, and 13C nuclear magnetic resonance methods. The results showed that the CC soil has the largest pore volume (PV) and specific surface area (SSA). PV, SSA, and aliphatic carbon content of the samples ranked as Clay-OM > HM > soil. Adsorption experiments indicated that the Clay-OM exhibited the strongest adsorption affinity for both DBP and DEP, followed by HM, and then the soil samples. Furthermore, DEP and DBP adsorption amounts on the samples declined as follows: CC > CS > CZ > YC. To illustrate the dominant mechanisms for PAEs adsorption onto soil, the soil organic carbon content normalized adsorption coefficient (LogKoc) was correlated with several possible parameters using multiple parameter linear regression and significance testing. The R2 values of the DBP and DEP in multi-regression equations were 0.825 and 0.741 respectively, and the significance test suggested that pore structure and specific surface area had crucial influences on the adsorption progress.

Model for Predicting Toxicities of Metals and Metalloids in Coastal Marine Environments Worldwide.

Metals can pose hazards to marine species and can adversely affect structures and functions of communities of marine species. However, little is known about how structural properties of metal atoms combined with current geographical and climatic conditions affect their toxic potencies. A mathematical model, based on quantitative structure-activity relationships and species sensitivity distributions (QSAR-SSD) was developed by use of acute toxicities of six metals (Cd, Cr, Cu, Hg, Ni, and Zn) to eight marine species and accessory environmental conditions. The model was then used to predict toxicities of 31 metals and metalloids and then to investigate relationships between acute water quality criteria (WQC) and environmental conditions in coastal marine environments. The model was also used to predict WQC in the coastal areas of different countries. Given global climate change, the QSAR-SSD model allows development of WQC for metals that will be protective of marine ecosystems under various conditions related to changes in global climate. This approach could be of enormous benefit in delivering an evidence-based approach to support regulatory decision making in management of metal and metalloids in marine waters.

An enantiomer-based virtual screening approach: Discovery of chiral organophosphates as acetyl cholinesterase inhibitors.

Chiral organophosphates (OPs) have been used widely around the world, very little is known about binding mechanisms with biological macromolecules. An in-depth understanding of the stereo selectivity of human AChE and discovering bioactive enantiomers of OPs can decrease health risks of these chiral chemicals. In the present study, a flexible molecular docking approach was conducted to investigate different binding modes of twelve phosphorus enantiomers. A pharmacophore model was then developed on basis of the bioactive conformations of these compounds. After virtual screening, twenty-four potential bioactive compounds were found, of which three compounds (Ethyl p-nitrophenyl phenylphosphonate (EPN), 1-naphthaleneacetic anhydride and N,4-dimethyl-N-phenyl-benzenesulfonamide) were tested by use of different in vitro assays. S-isomer of EPN was also found to exhibit greater inhibitory activity towards human AChE than the corresponding R-isomer. These findings affirm that stereochemistry plays a crucial role in virtual screening, and provide a new insight into designing safer organ phosphorus pesticides on human health.

Removal of phosphate from eutrophic lakes through adsorption by in situ formation of magnesium hydroxide from diatomite.

Since in situ formation of Mg(OH)2 can efficiently sorb phosphate (PO4) from low concentrations in the environment, a novel dispersed magnesium oxide nanoflake-modified diatomite adsorbent (MOD) was developed for use in restoration of eutrophic lakes by removal of excess PO4. Various adsorption conditions, such as pH, temperature and contact time were investigated. Overall, sorption capacities increased with increasing temperature and contact time, and decreased with increasing pH. Adsorption of PO4 was well described by both the Langmuir isotherm and pseudo second-order models. Theoretical maximum sorption capacity of MOD for PO4 was 44.44-52.08 mg/g at experimental conditions. Characterization of PO4 adsorbed to MOD by use of X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and solid state (31)P nuclear magnetic resonance revealed that electrostatic attraction, surface complexation and chemical conversion in situ were the major forces in adsorption of PO4. Mg(OH)2 formed in situ had a net positive charge on the surface of the MOD that could adsorb PO4(3-) and HPO4(2-) anion to form surface complex and gradually convert to Mg3(PO4)2 and MgHPO4. Efficiency of removal of PO4 was 90% when 300 mg MOD/L was added to eutrophic lake water. Results presented here demonstrated the potential use of the MOD for restoration of eutrophic lakes by removal of excess PO4.

Toxicity reference values for polybrominated diphenyl ethers: risk assessment for predatory birds and mammals from two Chinese lakes.

PBDEs are persistent organic pollutants, and have the capability to produce adverse effects on organisms. Aquatic piscivorous species at higher trophic levels have the greatest exposure risk. Information on the toxic potency of a commercial PBDE mixture, DE-71, to mink and American kestrel was reviewed, and dietary- and tissue-based TRVs were derived and evaluated for ecological risk assessment of aquatic piscivorous species inhabiting wetland areas in China. The effect on mink thyroid function was identified as the most appropriate and protective endpoint for deriving the TRV s for mammals. The TRV was based on dietary exposure, and wa s0.1 mg DE-71/kg (wm) or 0.01 mg DE-71/kg (bm)/day (ADI); for liver of mammals,the TRV was 1.2 mg LPBDEslkg (lm). For birds, reproductive effects on American kestrels were used to derive the TRVs, in which an overall UF of 3.0 was used. The TRV was based on dietary exposure, and was 0.1 mg DE-71/kg (wm) or 0.018 mg DE-71/kg (bm)/day (ADI); for eggs of birds, the TRV was 2.35 jlgLPBDEs/g (lm). Reported concentrations of PBDEs in livers of aquatic mammals found dead, and in fish and bird eggs from Chinese wetland areas were compiled and compared to the corresponding criteria values. Results indicated that TRV values reported in this study can be used as indicators for screening-level risk assessment of piscivorous species in Chinese aquatic systems. Furthermore, based on monitoring concentrations of PBDEs in fishes from two lakes (DCL and TL) in China and the dietary-based TRV of 0.1 mg DE-71/kg (wm), a screening-level risk assessment of PBDEs was performed for predatory birds and mammals. The results suggest that concentrations of PBDEs in these two areas would not be expected to cause any adverse effects on the local fish-eating wild birds and mammals.

Setting water quality criteria in China: approaches for developing species sensitivity distributions for metals and metalloids.

Both nonparametric and parametric approaches were used to construct SSDs for use in ecological risk assessments. Based on toxicity to representative aquatic species and typical water contaminants of metals and metalloids in China, nonparametric methods based on the bootstrap were statistically superior to the parametric curve-fitting approaches. Knowing what the SSDs for each targeted species are might help in selecting efficient indicator species to use for water quality monitoring. The species evaluated herein showed sensitivity variations to different chemical treatments that were used in constructing the SSDs. For example, D. magna was more sensitive than most species to most chemical treatments, whereas D. rerio was sensitive to Hg and Pb but was tolerant to Zn. HC5 values, derived for the pollutants in this study for protecting Chinese species, differed from those published by the USEPA. Such differences may result from differences in geographical conditions and biota between China and the United States. Thus, the degree of protection desired for aquatic organisms should be formulated to fit local conditions. For approach selection, we recommend all approaches be considered and the most suitable approaches chosen. The selection should be based on the practical information needs of the researcher (viz., species composition, species sensitivity, and geological characteristics of aquatic habitats), since risk assessments usually are focused on certain substances, species, or monitoring sites. We used Tai Lake as a typical freshwater lake in China to assess the risk of metals and metalloids to the aquatic species. We calculated hazard quotients for the metals and metalloids that were found in the water of this lake. Results indicated the decreasing ecological risk of these contaminants in the following order: Hg

Toxicity reference values for protecting aquatic birds in China from the effects of polychlorinated biphenyls.

PCBs are typical of persistent, bioaccumulative and toxic compounds (PBTs) that are widely distributed in the environment and can biomagnify through aquatic food webs, because of their stability and lipophilic properties. Fish-eating birds are top predators in the aquatic food chain and may suffer adverse effects from exposure to PCB concentrations. In this review, we address the toxicity of PCBs to birds and have derived tissue residue guidelines (TRGs) and toxic reference values (TRVs) for PCBs for protecting birds in China. In deriving these protective indices, we utilized available data and three approaches, to wit: species sensitivity distribution (SSD), critical study approach (CSA) and toxicity percentile rank method (TPRM). The TRGs and TRVs arrived at by using these methods were 42.3, I 0. 7, 4.3 pg TEQs/g diet wm and 16.7, 15.5, and 5.5 pg TEQs/g tissue wm for the CSA SSD and TPRM approaches, respectively. These criteria values were analyzed and compared with those derived by others. The following TRG and TRY, derived by SSD, were recommended as avian criteria for protecting avian species in China: 10.7 pg TEQs/g diet wm and 15.5 pg TEQs/g tissue wm, respectively. The hazard of PCBs to birds was assessed by comparing the TRVs and TRGs derived in this study with actual PCB concentrations detected in birds or fish. The criteria values derived in this study can be used to evaluate the risk of PCBs to birds in China, and to provide indices that are more reasonable for protecting Chinese avian species. However, several sources of uncertainty exists when deriving TRGs and TRVs for the PCBs in birds, such as lack of adequate toxicity data for birds and need to use uncertainty factors. Clearly, relevant work on PCBs and birds in China are needed in the future. For example, PCB toxicity data for resident avian species in China are needed. In addition, studies are needed on the actual PCB levels in birds and fish in China. Such information is needed to serve as a more firm foundation for future risk assessments.

Predicting water quality criteria for protecting aquatic life from physicochemical properties of metals or metalloids.

Metals are widely distributed pollutants in water and can have detrimental effects on some aquatic life and humans. Over the past few decades, the United States Environmental Protection Agency (U.S. EPA) has published a series of criteria guidelines, which contain specific criteria maximum concentrations (CMCs) for 10 metals. However, CMCs for other metals are still lacking because of financial, practical, or ethical restrictions on toxicity testing. Herein, a quantitative structure activity relationship (QSAR) method was used to develop a set of predictive relationships, based on physical and chemical characteristics of metals, and predict acute toxicities of each species for five phyla and eight families of organisms for 25 metals or metalloids. In addition, species sensitivity distributions (SSDs) were developed as independent methods for determining predictive CMCs. The quantitative ion character-activity relationships (QICAR) analysis showed that the softness index (σp), maximum complex stability constants (log -ß(n)), electrochemical potential (ΔE(0)), and covalent index (X(m)(2)r) were the minimum set of structure parameters required to predict toxicity of metals to eight families of representative organisms. Predicted CMCs for 10 metals are in reasonable agreement with those recommended previously by U.S. EPA within a difference of 1.5 orders of magnitude. CMCs were significantly related to σp (r(2) = 0.76, P = 7.02 × 10(-9)) and log -ß(n) (r(2) = 0.73, P = 3.88 × 10(-8)). The novel QICAR-SSD model reported here is a rapid, cost-effective, and reasonably accurate method, which can provide a beneficial supplement to existing methodologies for developing preliminarily screen level toxicities or criteria for metals, for which little or no relevant information on the toxicity to particular classes of aquatic organisms exists.

Multiple roles of extracellular polymeric substance in nitrobenzene reduction by nano-sized zero-valent iron in water and their mechanism.

Extracellular polymeric substance (EPS) is secreted by many organisms and makes up a significant constituent of natural organic matter in the environment. However, nothing is known about EPS's role in the reduction of pollutants by nano-sized zero-valent iron (NZVI). This research showed that the degradation kinetics of nitrobenzene (NB) by NZVI with EPS (0.0272 ± 0.006 min-1) were 2.27 times lower than that without EPS (0.0618 ± 0.006 min-1) in the first cycle, mainly due to competition for reactive sites on the NZVI surface and the complexation of EPS with Fe(II) and Fe(III). In the second and third cycle, the degradation kinetics of NB by NZVI alone decreased obviously, while those in the presence of EPS were preserved or accelerated. Comparative studies with a quinine model compound indicated that EPS did not function as the electron shuttle to transmit electrons effectively. X-ray photoelectron spectroscopy, scanning electron microscopy and X-ray diffraction results suggested that EPS could prevent the oxidation of NZVI and even expose more effective sites on the NZVI surface, thus leading to the preservation or enhancement of NZVI reactivity in the second and third NB degradation cycles. Moreover, we found that EPS also provided colloidal stability to NZVI particles, either by steric mechanisms or electrostatic repulsion. These results indicate that EPS can play an important role in the prolongation of NZVI reactivity during standing application.

Several major issues concerning the environmental transmission and risk prevention of SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is the most serious infectious disease pandemic in the world in a century, and has had a serious impact on the health, safety, and social and economic development of all mankind. Since the earth entered the "Anthropocene", human activities have become the most important driving force of the evolution of the earth system. At the same time, the epidemic frequency of major human infectious diseases worldwide has been increasing, with more than 70% of novel diseases having zoonotic origins. The review of several major epidemics in human history shows that there is a common rule, i.e., changes in the natural environment have an important and profound impact on the occurrence and development of epidemics. Therefore, the impact of the natural environment on the current COVID-19 pandemic and its mechanisms have become scientific issues that need to be resolved urgently. From the perspective of the natural environment, this study systematically investigated several major issues concerning the environmental transmission and risk prevention of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). From a macroscopic temporal and spatial scale, the research focus on understand the impact of the destruction of the natural environment and global changes on the outbreak of infectious diseases; the threat of zoonotic diseases to human health; the regularity for virus diffusion, migration and mutation in environmental media; the mechanisms of virus transmission from animals and environmental media to humans; and environmental safety, secondary risk prevention and control of major epidemics. Suggestions were made for future key research directions and issues that need attention, with a view to providing a reference for the prevention and control of the global coronavirus disease 2019, and to improving the ability of response to major public health emergencies.

Determination of 21 photoinitiators in human plasma by using high-performance liquid chromatography coupled with tandem mass spectrometry: A systemically validation and application in healthy volunteers.

In the present study, a comprehensive and sensitive method for simultaneous determination of 21 PIs (nine benzophenones, eight amine co-initiators, and four thioxanthones) in human plasma using high-performance liquid chromatography coupled with tandem mass spectrometry was developed and validated. Two different pre-treatment approaches (liquid-liquid extraction (LLE) and LLE coupled with solid-phase extraction (SPE)) and eight extraction solvents were studied to optimize sample treatment to obtain good recoveries and reduce any matrix effects. The procedure of LLE+SPE was selected as final sample treatment procedure because it obtained higher recoveries as well as lower matrix effects than that performed by LLE alone. The recoveries of 21 target analytes at three spiked concentrations (0.05, 0.5, and 5 ng/mL) ranged from 81% to 109%. The intra- and inter-day relative standard deviations were between 2.5% and 13%. Accuracy and precision data indicated that the detection method was accurate and precise for most of the PIs. The linearities of the labeled dilution calibration curves at 10 concentration levels (iLOQ to 100 ng/mL or iLOQ to 200 ng/mL) were good with correlation coefficients ranged from 0.995 to 0.999. The method quantification limits were in the range of 1.7-16 pg/mL. The analytical method was applied to the analysis of PIs in 14 human plasma samples collected from pregnant women in Guangdong Province, China. Fifteen PIs were detected with total concentrations ranging from 318 to 2772 pg/mL. The ubiquitous contamination of human plasma with PIs suggests that there is widespread exposure to these compounds. Consequently, there should be increased awareness of these pollutants in the environment.

Transmission of SARS-CoV-2 virus and ambient temperature: a critical review.

The coronavirus disease 2019 (COVID-19) pandemic has brought unprecedented public health, and social and economic challenges. It remains unclear whether seasonal changes in ambient temperature will alter spreading trajectory of the COVID-19 epidemic. The probable mechanism on this is still lacking. This review summarizes the most recent research data on the effect of ambient temperature on the COVID-19 epidemic characteristic. The available data suggest that (i) mesophilic traits of viruses are different due to their molecular composition; (ii) increasing ambient temperature decreases the persistence of some viruses in aquatic media; (iii) a 1°C increase in the average monthly minimum ambient temperatures (AMMAT) was related to a 0.72% fewer mammalian individuals that would be infected by coronavirus; (iv) proportion of zoonotic viruses of mammals including humans is probably related to their body temperature difference; (v) seasonal divergence between the northern and southern hemispheres may be a significant driver in determining a waved trajectory in the next 2 years. Further research is needed to understand its effects and mechanisms of global temperature change so that effective strategies can be adopted to curb its natural effects. This paper mainly explores possible scientific hypothesis and evidences that local communities and authorities should consider to find optimal solutions that can limit the transmission of SARS-CoV-2 virus.

3D-QSARs and molecular dynamics simulation studies on induced fit binding of flavones to human aldose reductase.

Communicated by Ramaswamy H. Sarma.

Transformation and Cytotoxicity of Surface-Modified Silver Nanoparticles Undergoing Long-Term Aging.

Silver nanoparticles (AgNPs) are constituents of many consumer products, but the future of their production depends on ensuring safety. The stability of AgNPs in various physiological solutions and aging in storage may affect the accuracy of predicted nanoparticle toxicity. The goal of this study was to simulate the transformation of AgNPs in different media representatives to the life cycle in the environment and to identify their toxicity to Hepa1c1c7 cells in a long-term aging process. AgNPs coated with citrate, polyethylene glycol (PEG), polyvinylpyrrolidone (PVP), and branched polyethyleneimine (BPEI) were studied. Our results show that the exposure media had a significant impact on the transformation of AgNPs. Citrate-coated AgNPs showed significant aggregation in phosphate-buffered saline. The aging of AgNPs in optimal storage showed that the charge-stabilized particles (citrate) were more unstable, with significant aggregation and shape changes, than sterically stabilized particles (PEG AgNPs, PVP AgNPs). The BPEI AgNPs showed the highest dissolution of AgNPs, which induced significantly increased toxicity to Hepa1c1c7 cells. Overall, our findings showed that storage and media of AgNPs influenced the transformation of AgNPs and that the resulting changes in the AgNPs' physicochemical properties influenced their toxicity. Our study contributes to the understanding of AgNPs' transformations under realistic exposure scenarios and increasing the predictability of risk assessments.

The effect of incorporating inorganic materials into quaternized polyacrylic polymer on its mechanical strength and adsorption behaviour for ibuprofen removal.

Quaternized polyacrylic polymer has many applications in water treatment because of its ion exchange effects, but its further industrial applications are largely restricted because of its poor mechanical strength. In this work, a magnetic anion exchange resin with a polyacrylic matrix (MAP) was prepared by incorporation of Fe3O4 and subsequent modification with tetraethyl orthosilicate (TEOS) to improve the mechanical strength and adsorption performance. The incorporation of Fe3O4 significantly enhanced the mechanical strength of the polymer and improved the sphericity rate after ball milling of the polyacrylic resin from 80.1% to 97.2% as a result of hydrogen bonding between the -OH groups on Fe3O4 and the -NH- groups on the resin matrix. Further TEOS modification could effectively prevent Fe3O4 particles from dislodging from the resins. The adsorption performance was evaluated by using ibuprofen as a model compound. The adsorption kinetics showed that adsorption equilibrium was reached in 150 min. XPS analysis indicated that hydrogen bonding greatly contributed to the adsorption of ibuprofen onto the MAP. Adsorption isotherm analysis indicated that the adsorption was endothermic.