Search Results (63)

Dried orange pulp (Citrus sinensis) is known for its antioxidant properties. This study aimed to examine the effects of adding dried orange pulp (OP) to the layers’ diets on the concentration of selected elements in the egg. The present work was part of a bigger project aiming to investigate the effect of orange pulp in layers’ diets on the performance of birds and egg quality. There were three dietary treatments and 63 layers per treatment, with 189 layers in total. Cages were the experimental units, and seven cages were allocated per treatment (n = 7). The dietary treatments were (1) a control treatment (C) that involved a basal diet without orange pulp addition, (2) an OP treatment with the addition of 9% dried orange pulp, and (3) a hesperidin–naringin (EN) treatment with 0.767 g hesperidin and 0.002 g naringin added per kg of diet; these levels of hesperidin and naringin represent those present in dried orange pulp for the OP treatment. Birds were fed the diets for 30 days. The diets had similar energy and protein levels and contained the same vitamin and mineral premixes. The analyzed egg (yolk, albumen, shell) elemental profile consisted of As, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Sb, Se, Sr, V, and Zn and was determined via Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Dried orange pulp supplementation significantly altered the elemental profile. OP largely altered the element concentrations in albumen and egg yolk. Most notably, it decreased the concentrations of Co (p < 0.001), Fe (p < 0.001), Mn (p < 0.001), Ni (p = 0.046), and Se (p = 0.035) in egg yolk and those of Co (p = 0.011), Fe (p = 0.025), Cr (p = 0.049), Cu (p = 0.001), and Se (p = 0.014) in albumen. In addition, it decreased the concentrations of As (p = 0.025) and Ca (p = 0.025) in the eggshell. Principal component analysis was applied to the concentrations of the examined elements in all egg parts to explore the relationships between the elements and detect those capable of distinguishing samples, resulting in the apparent separation of yolk, albumen, and eggshell samples. Further analysis revealed that all samples were clustered into the three dietary treatments, resulting in 100% correct classification. The chelating and antioxidant capacities of flavonoids are intricate and rely on a variety of factors. OP supplementation modulated the deposition of specific elements in egg parts in comparison to those from layers fed a typical diet. Thus, this study indicated that eggs with specialized elemental profiles could be created. Full article

Microminerals such as cobalt (Co), copper (Cu), iodine (I), iron (Fe), manganese (Mn), molybdenum (Mo), selenium (Se), and zinc (Zn) play key roles in cattle health. However, trace element imbalances are often underdiagnosed. This study retrospectively analyzed serum samples from 1273 cows across 117 herds in Spain, encompassing conventional dairy (n = 46), pasture-based dairy (n = 11), organic dairy (n = 25), and semi-extensive beef (n = 35) systems. Trace elements were determined by inductively coupled plasma mass spectrometry (ICP-MS). All herds were investigated for clinical or productive issues where mineral deficiencies were suspected. Significant differences were found in serum trace mineral concentrations between production systems. Adequacy rates were highest in conventional dairy herds receiving routine mineral supplementation, while deficiencies in Se, I, and Cu were frequently detected in pasture-based, organic, and beef herds. Zinc deficiencies were rare and typically involved complex, combined deficiencies. At the farm level, multielement deficiencies (≥3 elements) were detected in 39–45% of organic, pasture-based, and beef herds, but in only 5% of conventional dairy herds (p < 0.001). Principal component and cluster analyses produced consistent groupings of minerals according to dietary supplementation and soil-driven exposure. These findings highlight the increased vulnerability of low-input systems to complex micromineral imbalances and underline the importance of system-adapted mineral-monitoring and supplementation strategies in herd health management. However, as the study is based on diagnostic submissions rather than a randomized herd survey, the findings should be interpreted with caution due to potential selection bias. Full article

Polyoxometalate (POM)-type supramolecular materials have unique structures and hold immense potential for development in the fields of biomedicine, information storage, and electrocatalysis. In this study, (NH₄)₃ [AlMo₆O₂₄H₆]·7H₂O was employed as a polyacid anion template, pentacyclic imidazole molecules served as organic ligands, and the moderate-temperature hydrothermal and natural evaporation methods were used in combination for the design and synthesis of two octamolybdenum-oxo cluster (homopolyacids containing molybdenum-oxygen structures as the main small-molecular structures)-based organic–inorganic hybrid compounds, [(C₃N₂H₅)(C₃N₂H₄)][(β-Mo₈O₂₆H₂)]_0.5 (1) and {Zn(C₃N₂H₄)₄}{[(γ-Mo₈O₂₆)(C₃N₂H₄)₂]_0.5}·2H₂O (2). Structural and property characterization revealed that both compounds crystallized in the P-1 space group with relatively stable three-dimensional structures under the action of hydrogen bonding. Upon temperature stimulation, the [Zn(C₃N₂H₄)₄]²⁺ cation and water molecules in 2 exhibited obvious oscillations, leading to significant dielectric anomalies at approximately 250 and 260 K when dielectric testing was conducted under heating conditions. Full article

In this study, density functional theory (DFT) was used to analyze the processes that govern the interactions among triethylaluminum (TEAL), the Ziegler–Natta (ZN) catalyst, and the inhibitory compounds dimethylamine (DMA) and diethylamine (DEA) during olefin polymerization. The structural and charge characteristics of these inhibitors were examined through steric maps and DFT calculations. Combined DFT calculations (D3-B3LYP/6-311++G(d,p)) and IR spectroscopic analysis show that the most efficient way to deactivate the ZN catalyst is via the initial formation of the TEAL·DMA complex. This step has a kinetic barrier of only 27 kcal mol⁻¹ and a negative ΔG, in stark contrast to the >120 kcal mol⁻¹ required to form TEAL·DEA. Once generated, TEAL·DMA adsorbs onto the TiCl₄/MgCl₂ cluster with adsorption energies of −22.9 kcal mol⁻¹ in the gas phase and −25.4 kcal mol⁻¹ in n-hexane (SMD model), values 5–10 kcal mol⁻¹ more favorable than those for TEAL·DEA. This explains why, although dimethylamine is present at only 140 ppm, its impact on productivity (−19.6%) is practically identical to that produced by 170 ppm of diethylamine (−20%). The persistence of the ν(Al–N) band at ~615 cm⁻¹, along with a >30% decrease in the Al–C/Ti–C bands between 500 and 900 cm⁻¹, the downward shift of the N–H stretch from ~3300 to 3200 cm⁻¹, and the +15 cm⁻¹ increase in ν(C–N) confirm Al←N coordination and blockage of alkyl transfer, establishing the TEAL·DMA → ZN pathway as the dominant catalytic poisoning mechanism. Full article

Delineating soil management zones in cocoa cultivation areas can help optimize production and minimize ecological and environmental risks. This research assessed the spatial distribution of heavy metal concentration and soil fertility indicators in Cross River State, Nigeria, to delineate soil management zones (MZs). A total of n = 63 georeferenced, composite soil samples were collected at the 0–30 cm depth increment, air-dried, and subjected to physicochemical analysis. The soil data were subjected to principal component analysis (PCA), and the selected principal components (PCs) were used for fuzzy c-means clustering analysis to delineate the MZs. The result indicated that soil pH varied from 4.8 (strongly acidic) to 6.3 (slightly acidic), with high average organic carbon contents. The degree of contamination was low, while the ecological risk indicator (RI) of the environment under cocoa cultivation ranged from low risk (RI = 18.24) to moderate risk (RI = 287.15), with moderate risk areas mostly found in patches around the central and upper regions. Higher pH was associated with increased levels of exchangeable Ca, Mg, and K, and TN and OC. Strong spatial dependence was observed for silt, pH, OC, Mg, Zn, Cu, Pb, Cd, Cr, and DC. The result showed the first six principal components (PCs) with eigenvalues >1 accounting for 83.33% of the cumulative variance, and three MZs were derived via the selected six PCs using fuzzy c-means clustering analysis. The results of this study further indicated that MZ3 had the highest pH (6.06), TN (0.24%), OC (2.79%), exchangeable Ca (10.62 cmol/kg), Mg (4.01 cmol/kg), and K (0.12 cmol/kg). These were significantly (p < 0.05) higher than those observed in MZ2 and MZ1, and they represent the most fertile parts of the study area. Furthermore, 40.6% of the study area had marginal soil (i.e., soil under MZ2). Full article

The Mekong Delta, an important agricultural and economic hub in Vietnam, has suffered from severe water quality issues caused by both natural and anthropogenic forces. This paper aims to conduct a rational statistical approach to evaluate the current situation of surface water quality in the Mekong Delta, applying Factor Analysis (FA), Principal Component Analysis (PCA), and Agglomerative Hierarchical Clustering (AHC) to a database of 3117 samples collected by national and provincial monitoring stations. The results revealed significant contamination with organic pollutants (BOD5: 3.50–172.870 mg/L, COD: 6.493–472.984 mg/L), pesticides (e.g., DDTs: n.d to 1.227 mg/L), trace metals (As: 0.006–0.046 mg/L, Cr: n.d–1.960 mg/L), and microbial indicators (Coliforms: n.d–45,100 MPN/100 mL), often higher than the WHO drinking water threshold. PCA/AHC analysis identified the following five major pollution components: (1) organic pollution and sewage/industrial and deposited chemicals (PCA1—23.08% variance); (2) pesticide and agricultural runoff derived contamination with Hg (PCA2—15.44%); (3) microbial pollution of the water was found to correlate positively with Zn and Cu content (PCA3—8.90%); (4) salinity was found to mobilize As and Cr (PCA4—8.00%); (5) nutrient/microbial pollution presumably from agricultural and sewage inputs (PCA5—7.22%). AHC showed some spatial variability that grouped samples in urban/industrial (Cluster 1), rural/agricultural (Cluster 2), and a highly contaminated one, where water was toxic and presented with microbial and Cd contamination (Cluster 3). Levels of pesticides, Cr, and microbial pollution were higher than reported in previous Mekong Delta studies and exceeded regional trends. These results emphasize the importance of holistic water management strategies, including better wastewater treatment, pesticide control, sustainable farming, and climate-adaptive measures to reduce saltwater intrusion and safeguard drinking water quality for the Mekong Delta. Full article

The genetic variability of Coffea canephora is essential for the identification of genotypes with enhanced nutritional traits. This study aimed to characterize C. canephora genotypes based on nutrient accumulation in fruits, evaluated over two consecutive harvests. The experiment followed a randomized block design with four replications, comprising 42 genotypes. To assess nutrient accumulation, fruit samples were collected from each genotype and oven-dried. In a plant tissue analysis laboratory, the concentrations of N, P, K, Ca, Mg, S, Fe, Mn, Cu, Zn, and B were determined. Nutrient accumulation in the fruits was calculated as dry mass × nutrient concentration, and the data were converted to kg or g of nutrients accumulated per ton of coffee beans at 12% moisture content. The results revealed significant variability among genotypes in nutrient accumulation, with the general accumulation order being N > K > Ca > Mg > S > P > Mn > Fe > B > Cu > Zn. Multivariate analysis identified seven groups, with Verdim R, Clementino, and Pirata forming distinct clusters due to their unique characteristics. Clementino exhibited the highest nutrient accumulation, while LB1 had the lowest. The study demonstrated high heritability for all traits, indicating strong genetic control, along with significant positive correlations among nutrients. These findings highlight the potential of selecting nutrient-efficient genotypes to enhance the sustainability of coffee cultivation. The nutritional data obtained can support the development of more nutritionally efficient cultivars, ensuring long-term sustainability in coffee production. Full article

Selecting and breeding tea plant varieties with low nitrogen tolerance is crucial for reducing the application of nitrogen fertilizer in tea gardens and promoting the green and sustainable production of tea. Thus, a split-plot designed field experiment was conducted in a subtropical tea garden in China, where ten distinct cultivars were planted and exposed to two different levels of nitrogen (N) supply. This study aimed to assess the response of these cultivars to normal (450 kg ha⁻¹) and low (150 kg ha⁻¹) N fertilization treatments and to evaluate their tolerance to low N conditions. The results revealed notable differences in both the growth and biomass responses of the tea cultivars to N supply levels. Under low N supply, tea tree height, pruned litter biomass, and its nitrogen accumulation were all significantly lower than those under the normal N level. There was also a significant interaction effect between the cultivar and N level in the one-hundred-bud weight, new shoot yield, and its nitrogen content, respectively. The amount of total N uptake by harvested new shoots was relatively low, whereas a considerable amount of N was returned to the garden through pruned biomass. The aboveground biomass and its nitrogen accumulation could be considered as critical indicators for identifying nitrogen-tolerant cultivars with a variation coefficient by 20% and 20.57%, respectively. Additionally, cluster analysis showed that BY1 and LJ43 were strong low N-tolerant cultivars, while HJY was the most N-sensitive cultivar, closely followed by the ZN117 tea plants. In conclusion, significant disparities were observed in the adaptability of different tea cultivars to low N fertilization under the ambient field conditions. This study provided valuable theoretical insights and practical references for selecting N-tolerant tea varieties and reducing N fertilizer consumption in tea gardens. Full article

This study explores the chemical composition of different macrophyte species and infers their potential in extracting nutrients and some heavy metals from water as well as the use of macrophytes’ biomass as natural fertilizers. It used a dataset obtained from a previous study composed of 445 samples of chemical concentrations in the dried biomass of 16 macrophyte species collected from the Santana Reservoir in Rio de Janeiro, Brazil. Correlation tests, analysis of variance, and factor analysis of mixed data were performed to infer correspondences between the macrophyte species. The results showed that the macrophyte species can be grouped into three different clusters with significantly different profiles of chemical element concentrations (N, P, K⁺, Ca²⁺, Mg²⁺, S, B, Cu²⁺, Fe²⁺, Mn²⁺, Zn²⁺, Cr³⁺, Cd²⁺, Ni²⁺, Pb²⁺) in their biomass (factorial map from PCA). Most marginal macrophytes have a lower concentration of chemical elements (ANOVA p-value < 0.05). Submerged and floating macrophyte species presented a higher concentration of metallic and non-metallic chemical elements in their biomass (ANOVA p-value < 0.05), revealing their potential in phytoremediation and the removal of toxic compounds (such as heavy metal molecules) from water. A cluster of macrophyte species also exhibited high concentrations of macronutrients and micronutrients (ANOVA p-value < 0.05), indicating their potential for use as soil fertilizers. These results reveal that the plant’s location in the reservoir (marginal, floating, or submerged) is a relevant feature associated with macrophytes’ ability to remove chemical components from the water. The obtained results can contribute to planning the management of macrophyte species in large water reservoirs. Full article

Pollution is one of the most important issues currently affecting the global population and environment. Therefore, determining the zones where stringent measures should be taken is necessary. In this study, Principal Component Analysis (PCA), Factor Analysis (FA), and t-distributed Stochastic Neighbor Embedding (t-SNE) were utilized for dimensionality reduction and clustering of data series containing the concentration of 10 heavy metals collected at 14 locations. The Hazard Quotient (HQ) and Hazard Index (HI) were utilized to determine the non-carcinogenic risk to the population in the studied zones. The highest concentrations of metals in the samples were those of Fe, Zn, Mn, and Cr. PCA indicated that Fe and Zn (Co and Cd) had the highest contribution on the first (second) Principal Component (PC). FA showed that the three-factor model is adequate for explaining the variability of pollutant concentrations. The factor loadings revealed the strength of association between variables and factors, e.g., 0.97 for Zn, 0.83 for Cr, and 0.99 for Co. HQ for ingestion, ${HQ}_{ing},$ was the highest for Fe (between 6.10 × 10⁻⁵ and 2.57 × 10⁻⁴). HQ for inhalation, ${HQ}_{inh}$, was the biggest for Mn (from 1.41 × 10⁻³ to 1.95 × 10⁻³). HI varied in the interval [0.172, 0.573], indicating the absence of a non-carcinogenic risk. However, since values above 0.5 were determined at four sites, continuous monitoring of the pollution in the sampling locations is necessary. Full article

This study investigates the production and nutritional quality of Panicum maximum cv. Mombasa grass under varying levels of water stress and nitrogen (N) fertilization, aiming to enhance forage production in harsh environments. Four irrigation levels (5760, 6912, 4608, and 3456 m³ ha⁻¹ year⁻¹) and three N fertilizer doses (115, 57.5, and 0 kg ha⁻¹ year⁻¹) were tested. The results indicate that Mombasa grass produced higher fresh and dry weights under higher irrigation levels (I1 and I2) compared to water deficit conditions across all cuts. Interestingly, under moderate water stress (I3), the dry weight was not significantly different from that under higher irrigation for the sixth harvest in the first season. Water deficit conditions led to a significant reduction in protein content across all treatments. However, under lower irrigation levels (I3 and I4), there was a significant increase in phosphorus (P), potassium (K^₊), iron (Fe^2₊), and zinc (Zn) concentrations. A heatmap analysis of shape descriptors grouped the productivity and nutritional traits into two clusters based on their response to combined fertilization and drought stress. This analysis revealed that the dry weight, number of leaves, and Fe and Zn contents were positively affected under moderate water stress (80% of control; 4608 m³ ha⁻¹ year⁻¹) with recommended N fertilization. The study concludes that Panicum maximum cv. Mombasa is tolerant to moderate water stress and is suitable for forage production in the Qassim region, Saudi Arabia. Full article

The dehydrogenation of n-butane to butenes is a crucial process for producing valuable petrochemical intermediates. This study explores the role of oxyphilic metal promoters (Sn, Zn, and Ga) in enhancing the performance and stability of Pt@MFI catalysts for n-butane dehydrogenation. The presence of Sn in the catalyst inhibits the agglomeration of Pt clusters, maintaining their subnanometric particle size. PtSn@MFI exhibits superior stability and selectivity for butenes while suppressing cracking reactions, with selectivity for C1–C3 products as low as 2.1% at 550 °C compared to over 30.5% for Pt@MFI. Using a combination of high-angle annular dark-field scanning transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and Raman spectroscopy, we examined the structural and electronic properties of the catalysts. Our findings reveal that Zn tends to consume hydroxyl groups and substitute framework sites, and Ga induces more defective sites in the zeolite structure. In contrast, the interaction between SnO_x and the zeolite framework does not depend on reactions with hydroxyl groups. The incorporation of Sn significantly prevents Pt particle agglomeration, maintaining smaller Pt particle sizes and reducing coke formation compared to Zn and Ga promoters. Theoretical calculations showed that Sn increases the positive charge on Pt clusters, enhancing their interaction with the zeolite framework and reducing sintering, albeit with a slight increase in the energy barrier for C-H activation. These results underscore the dual benefits of Sn as a promoter, offering enhanced structural stability and reduced coke formation, thus paving the way for the rational design of more effective and durable catalysts for alkane dehydrogenation and other high-value chemical processes. Full article

The electrochemical nitrogen reduction reaction (NRR) is an attractive pathway for producing ammonia under ambient conditions. The development of efficient catalysts for nitrogen fixation in electrochemical NRRs has become increasingly important, but it remains challenging due to the need to address the issues of activity and selectivity. Herein, using density functional theory (DFT), we explore ten kinds of triple transition metal atoms (M₃ = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn) anchored on the C₂N monolayer (M₃-C₂N) as NRR electrocatalysts. The negative binding energies of M₃ clusters on C₂N mean that the triple transition metal clusters can be stably anchored on the N6 cavity of the C₂N structure. As the first step of the NRR, the adsorption configurations of N₂ show that the N₂ on M₃-C₂N catalysts can be stably adsorbed in a side-on mode, except for Zn₃-C₂N. Moreover, the extended N-N bond length and electronic structure indicate that the N₂ molecule has been fully activated on the M₃-C₂N surface. The results of limiting potential screen out the four M₃-C₂N catalysts (Co₃-C₂N, Cr₃-C₂N, Fe₃-C₂N, and Ni₃-C₂N) that have a superior electrochemical NRR performance, and the corresponding values are −0.61 V, −0.67 V, −0.63 V, and −0.66 V, respectively, which are smaller than those on Ru(0001). In addition, the detailed NRR mechanism studied shows that the alternating and enzymatic mechanisms of association pathways on Co₃-C₂N, Cr₃-C₂N, Fe₃-C₂N, and Ni₃-C₂N are more energetically favorable. In the end, the catalytic selectivity for NRR on M₃-C₂N is investigated through the performance of a hydrogen evolution reaction (HER) on them. We find that Co₃-C₂N, Cr₃-C₂N, Fe₃-C₂N, and Ni₃-C₂N catalysts possess a high catalytic activity for NRR and exhibit a strong capability of suppressing the competitive HER. Our findings provide a new strategy for designing NRR catalysts with high catalytic activity and selectivity. Full article

Zinc oxide (ZnO) is a wide bandgap semiconductor that holds significant potential for various applications. However, most of the native point defects in ZnO like Zn interstitials typically cause an n-type conductivity. Consequently, achieving p-type doping in ZnO is challenging but crucial for comprehensive applications in the field of optoelectronics. In this work, we investigated the electrical and optical properties of ex situ doped p-type ZnO films. The p-type conductivity has been realized by ion implantation of group V elements followed by rapid thermal annealing (RTA) for 60 s or flash lamp annealing (FLA) on the millisecond time scale in nitrogen or oxygen ambience. The phosphorus (P)-doped ZnO films exhibit stable p-type doping with a hole concentration in the range of 10¹⁴ to 10¹⁸ cm⁻³, while antimony (Sb) implantation produces only n-type layers independently of the annealing procedure. Microstructural studies of Sb-doped ZnO show the formation of metallic clusters after ms range annealing and SbZn-oxides after RTA. Full article

The [ZnL(ONO₂)₂] 1 and [ZnL(NCS)₂] 2 complexes were synthesized using self-assembly of the s-triazine tridentate ligand (L) with Zn(NO₃)₂·6H₂O and Zn(ClO₄)₂·6H₂O/NH₄SCN, respectively. The Zn(II) is further coordinated by two nitrate and two isothiocyanate groups as monodentate ligands in 1 and 2, respectively. Both complexes have distorted square pyramidal coordination environments where the extent of distortion is found to be greater in 2 (τ₅ = 0.41) than in 1 (τ₅ = 0.28). Hirshfeld calculations explored the significant C···O, C···C, N···H, and O···H contacts in the molecular packing of both complexes. The energy framework analysis gave the total interaction energies of −317.8 and −353.5 kJ/mol for a single molecule in a 3.8 Å cluster of 1 and 2, respectively. The total energy diagrams exhibited a strong resemblance to the dispersion energy frameworks in both complexes. NBO charge analysis predicted the charges of the Zn(II) in complexes 1 and 2 to be 1.217 and 1.145 e, respectively. The electronic configuration of Zn1 is predicted to be [core] 4S^0.32 3d^9.98 4p^0.45 4d^0.02 5p^0.01 for 1 and [core] 4S^0.34 3d^9.97 4p^0.53 4d^0.02 for 2. The increased occupancy of the valence orbitals is attributed to the donor→acceptor interactions from the ligand groups to Zn(II). The Zn(II) complexes were examined for their cytotoxic and antimicrobial activities. Both 1 and 2 have good cytotoxic efficiency towards HCT-116 and A-549 cancerous cell lines. We found that 1 is more active (IC₅₀ = 29.53 ± 1.24 and 35.55 ± 1.69 µg/mL) than 2 (IC₅₀ = 41.25 ± 2.91 and 55.05 ± 2.87 µg/mL) against both cell lines. Also, the selectivity indices for the Zn(II) complexes are higher than one, indicating their suitability for use as anticancer agents. In addition, both complexes have broad-spectrum antimicrobial activity (IC₅₀ = 78–625 μg/mL) where the best result is found for 2 against P. vulgaris (IC₅₀ = 78 μg/mL). Its antibacterial activity is found to be good compared to gentamycin (5 μg/mL) as a positive control against this microbe. Full article