Search Results (5)

In agricultural practice, in addition to determining the nitrogen (N_f) dose, it is necessary to effectively control its effect on currently grown crops. Meeting these conditions requires not only the use of phosphorus (P) and potassium (K), but also nutrients such as magnesium (Mg) and sulfur (S). This hypothesis was verified in a single-factor field experiment with winter wheat (WW) carried out in the 2015/2016, 2016/2017, and 2017/2018 growing seasons. The experiment consisted of seven variants: absolute control (AC), NP, NPK-MOP (K as Muriate of Potash), NPK-MOP+Ki (Kieserite), NPK-KK (K as Korn–Kali), NPK-KK+Ki, and NPK-KK+Ki+ES (Epsom Salt). The use of K as MOP increased grain yield (GY) by 6.3% compared to NP. In the NPK-KK variant, GY was 13% (+0.84 t ha⁻¹) higher compared to NP. Moreover, GYs in this fertilization variant (FV) were stable over the years (coefficient of variation, CV = 9.4%). In NPK-KK+Ki+ES, the yield increase was the highest and mounted to 17.2% compared to NP, but the variability over the years was also the highest (CV ≈ 20%). The amount of N in grain N (GN) increased progressively from 4% for NPK-MOP to 15% for NPK-KK and 25% for NPK-KK+Ki+ES in comparison to NP. The nitrogen harvest index was highly stable, achieving 72.6 ± 3.1%. All analyzed NUE indices showed a significant response to FVs. The PFP-N_f (partial factor productivity of N_f) indices increased on NPK-MOP by 5.8%, NPK-KK by 12.9%, and NPK-KK+Ki+ES by 17.9% compared to NP. The corresponding N_f recovery of N_f in wheat grain was 47.2%, 55.9%, and 64.4%, but its total recovery by wheat (grain + straw) was 67%, 74.5%, and 87.2%, respectively. In terms of the theoretical and practical value of the tested indexes, two indices, namely, NUP (nitrogen unit productivity) and NUA (nitrogen unit accumulation), proved to be the most useful. From the farmer’s production strategy, FV with K applied in the form of Korn–Kali proved to be the most stable option due to high and stable yield, regardless of weather conditions. The increase in the number of nutritional factors optimizing the action of nitrogen in winter wheat caused the phenomenon known as the “scissors effect”. This phenomenon manifested itself in a progressive increase in nitrogen unit productivity (NUP) combined with a regressive trend in unit nitrogen accumulation (NUA) in the grain versus the balance of soil available Mg (Mg_b). The studies clearly showed that obtaining grain that met the milling requirements was recorded only for NUA above 22 kg N t⁻¹ grain. This was possible only with the most intensive Mg treatment (NPK-KK+Ki and NPK-KK+Ki+ES). The study clearly showed that three of the six FVs fully met the three basic conditions for sustainable crop production: (i) stabilization and even an increase in grain yield; (ii) a decrease in the mass of inorganic N in the soil at harvest, potentially susceptible to leaching; and (iii) stabilization of the soil fertility of P, K, and Mg. Full article

Semiconductor photocatalysis is an effective strategy for solving the problems of increasing energy demand and environmental pollution. ZnIn₂S₄-based semiconductor photocatalyst materials have attracted much attention in the field of photocatalysis due to their suitable energy band structure, stable chemical properties, and good visible light responsiveness. In this study, ZnIn₂S₄ catalysts were modified by metal ion doping, the construction of heterojunctions, and co-catalyst loading to successfully prepare composite photocatalysts. The Co-ZnIn₂S₄ catalyst synthesized by Co doping and ultrasonic exfoliation exhibited a broader absorption band edge. Next, an a-TiO₂/Co-ZnIn₂S₄ composite photocatalyst was successfully prepared by coating partly amorphous TiO₂ on the surface of Co-ZnIn₂S₄, and the effect of varying the TiO₂ loading time on photocatalytic performance was investigated. Finally, MoP was loaded as a co-catalyst to increase the hydrogen production efficiency and reaction activity of the catalyst. The absorption edge of MoP/a-TiO₂/Co-ZnIn₂S₄ was widened from 480 nm to about 518 nm, and the specific surface area increased from 41.29 m²/g to 53.25 m²/g. The hydrogen production performance of this composite catalyst was investigated using a simulated light photocatalytic hydrogen production test system, and the rate of hydrogen production by MoP/a-TiO₂/Co-ZnIn₂S₄ was found to be 2.96 mmol·h⁻¹·g⁻¹, which was three times that of the pure ZnIn₂S₄ (0.98 mmol·h⁻¹·g⁻¹). After use in three cycles, the hydrogen production only decreased by 5%, indicating that it has good cycle stability. Full article

The field of coordination chemistry has undergone rapid transformation from preparation of monometallic complexes to multimetallic complexes. So far numerous multimetallic coordination complexes have been synthesized. Multimetallic coordination complexes with well-defined architectures are often called as metal organic polygons and polyhedra (MOPs). In recent past, MOPs have received tremendous attention due to their potential applicability in various emerging fields. However, the field of coordination chemistry of MOPs often suffer set back due to the instability of coordination complexes particularly in aqueous environment-mostly by aqueous solvent and atmospheric moisture. Accordingly, the fate of the field does not rely only on the water solubilities of newly synthesized MOPs but very much dependent on their stabilities both in solution and solid state. The present review discusses several methodologies to prepare MOPs and investigates their stabilities under various circumstances. Considering the potential applicability of MOPs in sustainable way, several methodologies (remedies) to enhance the stabilities of MOPs are discussed here. Full article

The importance of the dynamic interplay between the opioid and the serotonin neuromodulatory systems in chronic pain is well recognized. In this study, we investigated whether these two signalling pathways can be integrated at the single-cell level via direct interactions between the mu-opioid (MOP) and the serotonin 1A (5-HT_1A) receptors. Using fluorescence cross-correlation spectroscopy (FCCS), a quantitative method with single-molecule sensitivity, we characterized in live cells MOP and 5-HT_1A interactions and the effects of prolonged (18 h) exposure to selected non-peptide opioids: morphine, codeine, oxycodone and fentanyl, on the extent of these interactions. The results indicate that in the plasma membrane, MOP and 5-HT_1A receptors form heterodimers that are characterized with an apparent dissociation constant ${\mathrm{K}}_{\mathrm{d}}^{\mathrm{app}}$ = (440 ± 70) nM). Prolonged exposure to all non-peptide opioids tested facilitated MOP and 5-HT_1A heterodimerization and stabilized the heterodimer complexes, albeit to a different extent: ${\mathrm{K}}_{\mathrm{d}, \mathrm{Fentanyl}}^{\mathrm{app}}$ = (80 ± 70) nM), ${\mathrm{K}}_{\mathrm{d},\mathrm{Morphine}}^{\mathrm{app}}$ = (200 ± 70) nM, ${\mathrm{K}}_{\mathrm{d}, \mathrm{Codeine}}^{\mathrm{app}}$ = (100 ± 70) nM and ${\mathrm{K}}_{\mathrm{d}, \mathrm{Oxycodone}}^{\mathrm{app}}$ = (200 ± 70) nM. The non-peptide opioids differed also in the extent to which they affected the mitogen-activated protein kinases (MAPKs) p38 and the extracellular signal-regulated kinase (Erk1/2), with morphine, codeine and fentanyl activating both pathways, whereas oxycodone activated p38 but not ERK1/2. Acute stimulation with different non-peptide opioids differently affected the intracellular Ca²⁺ levels and signalling dynamics. Hypothetically, targeting MOP–5-HT_1A heterodimer formation could become a new strategy to counteract opioid induced hyperalgesia and help to preserve the analgesic effects of opioids in chronic pain. Full article

Efficient electrocatalyst plays a significant role on the development of hydrogen energy. In this work, an N,P-codoped carbon layer coupled with MoP nanoparticles (MoP/NPCs) was prepared through a facile high-temperature pyrolysis treatment. The obtained MoP/NPCs presented efficient activity for hydrogen evolution reaction (HER), with low onset potential of 90 mV, and a small Tafel slope (71 mV dec⁻¹), as well as extraordinary stability in acidic electrolyte. This work provides a new facile strategy for the design and synthesis of sustainable and effective molybdenum-based electrocatalysts as alternatives to non-Pt catalysts for HER. Full article