Ozone (O₃) is an adverse environmental factor posing damage to ornamental plants. Thus, it is important to seek an effective way of enhancing plant tolerance to O₃-induced damage. Methyl jasmonate (MJ) and melatonin (MT) are plant growth regulators (PGRs) involved in plant abiotic stress responses. In this study, compared with the control group of plants without ozone, the influence of exogenous MJ (0, 10, 50, 100, and 150 μM) and MT (0, 0.1, 0.5, 2.5, and 12.5 μM) on the resistance of Malus crabapple ‘Hong Jiu’ was evaluated under O₃ stress (100 ± 10 nL/L for 3 h). Our data revealed that levels of MDA were significantly enhanced following O₃ treatment compared with plants without O₃. O₃ induced the activities of antioxidant enzymes and the accumulation of non-enzymatic antioxidants. While lower malondialdehyde (MDA) content, greater activities of antioxidant enzymes, and higher levels of soluble protein and non-enzymatic antioxidants were observed in PGRs-pretreated plants than in non-PGRs-pretreated plants under O₃ stress. Based on the above results and air pollution tolerance index (APTI), an exogenous supply of MJ and MT to Malus crabapple ‘Hong Jiu’ seedlings was protective for O₃-induced toxicity. The present study provides new insights into the mechanisms of MJ and MT amelioration of O₃-induced oxidative stress damages in Malus crabapple ‘Hong Jiu.’

Mosses can be used as biomonitors to monitor radionuclide deposition and heavy metal pollution in cities, forests, and grasslands. The aims of this work were to determine the activity concentrations of natural (²¹⁰Po, ²¹⁰Pb or ²¹⁰Pbₑₓ (excess ²¹⁰Pb is defined as the activity of ²¹⁰Pb minus the activity of ²²⁶Ra), ⁷Be, ⁴⁰K, ²²⁶Ra, ²³⁸U, and ²³²Th) and anthropogenic radionuclides (¹³⁷Cs) in moss body profiles and in situ underlying soils of moss samples and to assess/determine the distribution features and accumulation of these radionuclides. Activity concentrations of radionuclides in the samples were measured using a low-background gamma spectrometer and a low-background alpha spectrometer. Consistent with their source, the studied radionuclides in the moss samples and underlying soils were divided according to the principal component analysis (PCA) results into an airborne group (²¹⁰Po, ²¹⁰Pb (²¹⁰Pbₑₓ), ⁷Be, and ¹³⁷Cs) and a terrestrial group (⁴⁰K, ²³⁸U, ²²⁶Ra, and ²³²Th). The activity concentrations of ²¹⁰Po and ²¹⁰Pbₑₓ in moss body profiles were mainly concentrated in the stems–rhizoid parts, in which we measured some of the highest ²¹⁰Po and ²¹⁰Pbₑₓ levels compared to the results in the literature. ⁷Be mainly accumulated in the leaves–stem parts. Different positive correlations were observed between ²¹⁰Po and ²¹⁰Pb and between ⁷Be and ²¹⁰Pb, which indicated that the uptake mechanisms of ²¹⁰Po, ²¹⁰Pb, and ⁷Be by moss plants were different, to some extent. ¹³⁷Cs was detected only in some moss samples, and the fraction of ¹³⁷Cs in the underlying soils was much lower than that in the moss, suggesting that mosses were protecting the underlying soils from further pollution. Except for ⁴⁰K, the terrestrial radionuclide (²³⁸U, ²²⁶Ra, and ²³²Th) content in mosses was predominantly at low levels, which indicated not only the inability of mosses to use those elements for metabolic purposes but also the rather poor capability of mosses to directly mobilize, absorb, and transport elements (U, Ra, or Th) not dissolved in water.

Soil erosion constitutes a serious threat for sustainable agriculture in many countries. Magnetic susceptibility of soil is a fast, cheap, and non-destructive technique that could be used to quantify soil erosion or soil redistribution on a long-term scale. This study attempts to analyze the variation of magnetic susceptibility in soil profiles having the same lithology and climatic conditions, but different land uses and slope gradients in a subcatchment in northern Morocco. Soil cores were collected on forested, cultivated, and pasture lands. Each core was associated to a field unit (also called a homogeneous unit) characterized by a set of four cited erosion factors. The samples were measured for mass–specific low-frequency magnetic susceptibility (χₗf) and frequency-dependent magnetic susceptibility (χfd). The linear correlation of χₗf and χfd indicates the homogeneity of magnetic population in soil. It supports the use of empirical models based on comparisons of χₗf to predict the value of magnetic parameter after tillage homogenization and removal of soil material from the surface, and to estimate soil erosion or redeposition. The study built a methodology improving these empirical models and enabling a quantitative approach of the phenomenon. Two models, namely “tillage homogenization” (as improved in this study) and the proposed “simple correlation” result in globally similar estimates of erosion, while another model, the “simple proportional” model, underestimates it. The results give an estimate of long-term erosion (deposition) in sampled units and allow drawing of an areal soil redistribution map in the watershed.

It is found that strong electronegative groups can selectively adsorb cellulose by hydrogen bonds. Grafting strong negatively charged groups onto catalysts to achieve the functionalization of the catalyst can give it the ability to selectively adsorb cellulose without affecting its catalysis, which is of great significance for the hydrolysis of cellulose. In this study, PTA@MIL-101–X (X = –Br, –NH₂, –Cl, –NO₂) materials were synthesized to investigate the effect of grafting different electronegative groups on carriers to the directional hydrolysis of cellulose. The synthesized catalysts used phosphotungstic acid as the catalytic center while treated MIL-101 structure as the carrier. The grafting of different electronegative groups changed the crystal structure of the metal organic framework without affecting its stability during the reaction. The strong negative functional groups can selectively adsorb cellulose by forming hydrogen bonds with cellulose hydroxyl groups and weaken the hydrogen bonds within cellulose molecules. This hydrogen bond can reduce the side reaction of glucose, lighten the difficulty of cellulose hydrolysis, and improve the efficiency of cellulose conversion at the same time. The hydrolysis rate of cellulose increased with the electronegativity enhancement of the grafted functional groups, and the grafted –NO₂ catalyst PTA@MIL-101–NO₂ obtained the highest glucose yield of 16.2% in the cellulose-directed hydrolysis. The –NH₂ can form a chemical linkage with PTA through electrostatic interaction to get the highest immobilization stability and exhibit excellent stability in the recycling of catalysts. Graphical abstract

Although the role that renewable energy consumption plays on economic growth and emissions has been widely studied, there are relatively few papers focusing on the determinants of renewable energy consumption, and only one study focuses on the factors related to the share of renewables in the energy consumption in Africa. This paper contributes to the literature by filling the gap in knowledge by exploring the nexus between the share of renewables in energy consumption and social and economic variables, for a panel consisting of 21 African countries for the period between 1990 and 2013, extending the set of variables and the time span used by a previous study. Estimating a random-effects generalized least squares regression, we find that countries with a higher Human Development Index and a higher gross domestic product per capita have a lower share of renewable energy in the national grid. On the other hand, an increase in foreign direct investment has been found to be related to higher renewable energy integration. The level of democracy, measured by the Freedom House political rights and civil liberties ratings, does not directly affect the integration level of renewable energy sources. The negative relationship between gross domestic product per capita and the share of renewables contradicts previous findings for developed countries. This contradiction and policy implications are discussed in the light of the review of the energy mix of the selected countries.

The growth and cadmium (Cd) accumulation of emergent plant Nasturtium officinale R. Br. cuttings taken from plants grafted onto rootstocks of four terrestrial Cruciferae species were studied in a pot experiment. Scions from N. officinale seedlings were grafted onto rootstocks of Brassica chinensis L., Raphanus sativus L., Brassica napus L., and Rorippa dubia (Pers.) H. Hara. Cuttings were taken after 1 month and grown in Cd-contaminated soil (10 mg Cd kg⁻¹) for 60 days. Compared with non-grafted N. officinale, grafting onto R. sativus and B. napus rootstocks increased the root, shoot, and whole plant biomasses of N. officinale cuttings. Brassica napus rootstock was more effective than R. sativus rootstock for increasing the biomass of N. officinale cuttings. The four rootstocks decreased or had no significant effect on photosynthetic pigment contents in N. officinale cuttings compared with non-grafted N. officinale. Only grafting onto B. napus rootstock enhanced antioxidant enzyme activities. Compared with non-grafted N. officinale, R. sativus and B. napus rootstocks decreased the Cd contents in roots and shoots of N. officinale cuttings, whereas the other rootstocks had no significant effect on the shoot Cd content. The four rootstocks had no increase effects on Cd extraction by N. officinale cuttings. Therefore, cutting after grafting did not enhance the phytoremediation ability of N. officinale for growth in Cd-contaminated soil. However, R. sativus and B. napus rootstocks decreased the Cd content in N. officinale cuttings, which offers a potential approach for N. officinale safety production as a wild vegetable in Cd-contaminated soils.

The role of energy cannot be passed over in the process of economic growth and development in any economy. China consumes colossal quantity of energy; thus, the central objectives of this study is to empirically evaluate the linkages among energy use, environment by CO₂ emissions, human health by health expenditures, Foreign Direct Investment (FDI) inflows, and real GDP per capita used for economic growth over the period of 1995–2016 for China. The nature of the data directed to employ the Canonical cointegrating regression (CCR) method for unknown parameter estimation. Four equations have estimated namely for FDI, health, environment, and economic growth. The result for China during the period under the study reveals that energy consumption has significant positive impact on FDI, health, environment, and economic growth. The study results suggest that policy makers need to chalk out effective policy for effective utilization of energy so as to encourage permissible economic growth and development in China.

Generally, fungi have the ability to secrete large amounts of secondary metabolites which have the ability to reduce metal ions to metallic nanoparticles. In this report, silver nanoparticles (AgNPs) were synthesized by using an endophytic fungus isolated from the medicinal plant, Catharanthus roseus (Linn.). The endophytic fungus was identified as Botryosphaeria rhodina based on the ITS sequencing. The synthesized AgNPs were characterized by adopting various high-throughput techniques, scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDAX), high-resolution transmission electron microscopy (HR-TEM) and UV–Visible spectrophotometer. In vitro anticancer efficacy of AgNPs was tested on A-549 cells. The synthesized AgNPs were effective in scavenging free radicals and induced hallmarks of apoptosis including nuclear and DNA fragmentation in lung (A549) cancer cell lines under in vitro conditions. The results suggested that the natural biomolecules in the endophytic fungi incorporated into the nanoparticles could be responsible for the synergetic cytotoxic activity against cancer cells. The AgNPs were found to have cytotoxicity IC₅₀ of 40 μg/mL against A549 cells. To the best our knowledge, this is the first report demonstrating that AgNPs from Botryosphaeria rhodina could be able to induce apoptosis in various types of cancer cells as a novel strategy for cancer treatment.

A magnesia–pullulan (MgOP) composite has been developed to remove phosphate from a synthetic solution. In the present study, the removal of phosphate by MgOP was evaluated in both a batch and dynamic system. The batch experiments investigated the initial pH effect on the phosphate removal efficiency from pH 3 to 12 and the effect of co-existing anions. In addition, the adsorption isotherms, thermodynamics, and kinetics were also investigated. The results from the batch experiments indicate that MgOP has encouraging performance for the adsorption of phosphate, while the initial pH value (3–12) had a negligible influence on the phosphate removal efficiency. Analysis of the adsorption thermodynamics demonstrated that the phosphate removal process was endothermic and spontaneous. Investigations into the dynamics of the phosphate removal process were carried out using a fixed bed of MgOP, and the resulting breakthrough curves were used to describe the column phosphate adsorption process at various bed masses, volumetric flow rates, influent phosphate concentrations, reaction temperatures, and inlet pH values. The results suggest that the adsorption of phosphate on MgOP was improved using an increased bed mass, while the reaction temperature did not significantly affect the performance of the MgOP bed during the phosphate removal process. Furthermore, higher influent phosphate concentrations were beneficial towards increasing the column adsorption capacity for phosphate. Several mathematic models, including the Adams–Bohart, Wolboska, Yoon–Nelson, and Thomas models, were employed to fit the fixed-bed data. In addition, the effluent concentration of magnesium ions was measured and the regeneration of MgOP investigated.

Annually, over 5.5 trillion cigarettes are produced worldwide, and it is estimated that 4.5 trillion cigarette butts (CBs) are still being littered in the world. The dispersal of the CBs has caused this hazardous waste to be considered as one of the most important litters and environmental risks all over the world. This systematic study with the search protocol definition and keyword identification was developed to find the CBs control and recycling methods by searching in five scientific databases. Founded articles were monitored and finally, 35 related articles were selected and studied by the authors. The results of this study showed that CBs recycling methods have been tested in 10 specific categories all over the world. The CBs have been applied without any pre-processing methods in the bricks and asphalt production. However, other applications of the CBs such as the absorbent material production, vector control, and use as a biofilm carrier in wastewater treatment need various processing methods. The researchers also presented models and suggestions such as taxes, penalties, and public education for the control of CBs littering. Despite the innovative methods applied for the CBs recycling in previous studies, CBs have not received much attention in terms of pollutant control and environmental issues in recycling processes.