Ga Content Research Articles

Effect of Ga on microstructure and properties of Ag50CuSn12 and Al2O3/oxygen-free copper welds

The effects of Ga on the properties of Ag50CuSn12 and brazed joints were studied. The results show that Ga can reduce the melting temperature of the Ag50CuSn12 and improve its wettability. With the increase of Ga content, the spreading area of the solder increases first and then decreases. And the spreading area is the largest when the content of Ga is 3 wt%, which is 48% higher than that without Ga. Ga plays an important role in grain refinement of weld microstructure. The size of the block particles in the weld decreases accompanied by the increase of Ga. The fine strip grains increase is evenly distributed. The refinement effect is also the best when the Ga content is 3 wt%. For this reason, the shear strength of the brazed joint of Al2O3 and oxygen-free copper increases first and then decreases. When the Ga content is 3 wt%, the shear strength is the highest, which is 2.2 times that of the joint without Ga.The analysis suggests that the incorporation of Ga lowers the melting point of the solder, improves its oxidation resistance, and reduces its surface tension and viscosity, thereby enhancing its wettability and diffusivity. However, excessive Ga can hinder the solder's spread.

Application of combined GA3 and NAA treatments to improve yield and quality of Okra (Abelmoschus esculentus L.)

In Bangladesh, okra is an important popular summer vegetable. However, traditional farming practices often lead to suboptimal yields. Thus, the study was designed to determine the ideal GA3 and NAA doses for accelerating okra growth, yield, and quality characteristics. A three-replication, randomized complete block design was adopted. Foliar sprays with three concentrations of GA3 (0 ppm, 150 ppm, and 250 ppm) and NAA (0 ppm, 150 ppm, and 250 ppm) were applied in 2022 and 2023. In comparison to the control, the combined application of GA3 @ 150 ppm and NAA @ 150 ppm improved plant height, leaf number, leaf area, branch number, internode length, bud number, pod number, pod length, pod diameter, and 1000 seed weight average over the two years. Furthermore, GA3 @ 150 ppm with NAA 150 ppm increased yield by 35.08% and 27.01% in 2022 and 2023 respectively, above the control. Combining NAA @ 150 ppm with GA3 resulted in higher levels of vitamin C, TSS, magnesium, and zinc by 19.31%, 81.2%, 22.73% and 21.43% in 2022 and 22.83%, 50.57%, 18.07%, 33.33% in 2023 respectively, compared to the control. In contrast, GA3 and NAA decreased potassium and calcium in both year when compared to the control. Overall, the results of this experiment indicated that using GA3 @ 150 ppm with NAA @ 150 ppm could enhance okra growth, yield, and quality. These findings provide insightful information for improving okra cultivation techniques and improving Bangladesh’s productivity in agriculture and food security.

Diversity of Treatments in Overcoming Morphophysiological Dormancy of Paeonia peregrina Mill. Seeds.

Paeonia peregrina Mill. is a protected, herbaceous species native to Southeastern Europe and Turkey. Due to its vulnerability, it has to be protected both in its natural habitats and through cultivation. Peonies are known to have a low potential for natural regeneration due to their seed dormancy, low germination rate, and long germination period. In this study, treatments with gibberellic acid (GA3 150, 200, 250, 300, and 350 mg L-1 GA3) and warm (at 20/16 °C day/night regime) and cold stratification (at 4 °C) were used to accelerate dormancy release and increase the germination rate. The seeds of P. peregrina from four natural habitats in Serbia and the Institute's collection were collected and analyzed. They showed an underdeveloped embryo that needs to grow inside the seed before it can germinate. The application of GA3 accelerated each stage of germination (seed coat rapturing, hypocotyl dormancy release, and epicotyl dormancy release) for approximately 10 days compared to the control. It was also found that two-day imbibition with 200 mg L-1 GA3 significantly accelerated and equalized germination. Higher GA3 concentrations had a more pronounced impact on each stage but also resulted in greater seed infection after the seed coat rupture, elongated and weak seedlings, while lower concentrations did not result in obtaining uniform seedlings. There were no significant differences observed between localities. Restoring P. peregrina through seeds and nursery-produced plants is crucial for conserving the genetic diversity of the tested species.

Influence of Tis108 on GA content and expression of key enzyme GeCYP714A1 involved in GA deactivation of Gastrodia elata

To investigate the influence of the strigolactone inhibitor Tis108 on the growth of Gastrodia elata, this study treated G. elata tuber with Tis108 solution of 10 μmol·L~(-1) and measured the content of endogenous hormone gibberellin(GA) in the tuber. By using reverse transcription-polymerase chain reaction(RT-PCR) technology, the key enzyme GeCYP714A1 gene involved in GA deactivation was cloned. Bioinformatics analysis on the GeCYP714A1 gene was carried out by using ExPASy, SWISS-MODEL, MEGA, etc., and its expression levels in different parts of G. elata were determined. The results showed that after Tis108 treatment, GA content in G. elata tuber was significantly increased, and the transcription level of the GeCYP714A1 gene was significantly decreased. The full length of the coding region of the GeCYP714A1 gene is 1 173 bp, encoding 390 amino acids. The protein has a molecular weight of 44.85 kDa, a theoretical isoelectric point of 9.83, an instability index of 49.20, an aliphatic index of 89.03, and a grand average of hydropathicity of-0.235, classifying it as an unstable, basic, hydrophilic protein, and the GeCYP714A1 protein was localized in the mitochondria, lacking a signal peptide and a transmembrane structure. Phylogenetic tree analysis revealed that GeCYP714A1 was most closely related to the DcCYP714C2(PKU78454.1) protein from Dendrobium candidum, with a sequence identity of 67.25%. The qRT-PCR analysis of the expression patterns of the GeCYP714A1 gene indicated that GeCYP714A1 had the highest transcription level in G. elata tuber, followed by stem and inflorescence. The study represented that Tis108 inhibited the transcription level of GeCYP714A1 involved in GA deactivation in G. elata tuber, thereby increasing the accumulation of GA and affecting the growth of G. elata tuber. These results provided a basis for further studies of strigolactone regulation of GA signal and tuber development in G. elata.

Response of Elymus nutans Griseb. seedling physiology and endogenous hormones to drought and salt stress

Elymus nutans Griseb. (E. nutans), a pioneer plant for the restoration of high quality pasture and vegetation, is widely used to establish artificial grasslands and ecologically restore arid and salinized soils. To investigate the effects of drought stress and salt stress on the physiology and endogenous hormones of E. nutans seedlings, this experiment configured the same environmental water potential (0 (CK), − 0.04, − 0.14, − 0.29, − 0.49, − 0.73, and − 1.02 MPa) of PEG-6000 and NaCl stress to investigate the effects of drought stress and salt stress, respectively, on E. nutans seedlings under the same environmental water potential. The results showed that although the physiological indices and endogenous hormones of the E. nutans seedlings responded differently to drought stress and salt stress under the same environmental water potential, the physiological indices of E. nutans shoots and roots were comprehensively evaluated using the genus function method, and the physiological indices of the E. nutans seedlings under the same environmental water potential exhibited better salt tolerance than drought tolerance. The changes in endogenous hormones of the E. nutans seedlings under drought stress were analyzed to find that treatment with gibberellic acid (GA3), gibberellin A7 (GA7), 6-benzyladenine (6-BA), 6-(y,y-dimethylallylaminopurine) (2.IP), trans-zeatin (TZ), kinetin (KT), dihydrozeatin (DHZ), indole acetic acid (IAA), and 2,6-dichloroisonicotininc acid (INA) was more effective than those under drought stress. By analyzing the amplitude of changes in the endogenous hormones in E. nutans seedlings, the amplitude of changes in the contents of GA3, GA7, 6-BA, 2.IP, TZ, KT, DHZ, IAA, isopentenyl adenosine (IPA), indole-3-butyric acid (IBA), naphthalene acetic acid (NAA), and abscisic acid was larger in drought stress compared with salt stress, which could be because the endogenous hormones are important for the drought tolerance of E. nutans itself. The amplitude of the changes in the contents of DHZ, TZR, salicylic acid, and jasmonic acid was larger in salt stress compared with drought stress. Changes in the content of melatonin were larger in salt stress compared with drought stress, which could indicate that endogenous hormones and substances are important for the salt tolerance of E. nutans itself.

Heavily Fe-doped quaternary-alloy ferromagnetic semiconductor (In,Ga,Fe)Sb

We study epitaxial growth and physical properties of heavily Fe-doped quaternary-alloy ferromagnetic semiconductor (In0.84−x ,Ga x ,Fe0.16)Sb thin films (Ga content x = 2%–10%, Fe content fixed at 16%). The (In0.84−x ,Ga x ,Fe0.16)Sb films have a zinc-blende-type crystal structure without any other second phase, and all the samples exhibit intrinsic ferromagnetism with high Curie temperature (>300 K). The carrier type of the (In0.84−x ,Ga x ,Fe0.16)Sb films is found to change by varying x, and a carrier-type phase diagram of (In,Ga,Fe)Sb is presented. These results suggest that (In,Ga,Fe)Sb is a promising material for semiconductor spintronic devices, such as ferromagnetic p-n junctions, operating at RT.

Melatonin Priming Promotes Crop Seed Germination and Seedling Establishment Under Flooding Stress by Mediating ABA, GA, and ROS Cascades.

Both seed germination and subsequent seedling establishment are key checkpoints during the life cycle of seed plants, yet flooding stress markedly inhibits both processes, leading to economic losses from agricultural production. Here, we report that melatonin (MT) seed priming treatment enhances the performance of seeds from several crops, including soybean, wheat, maize, and alfalfa, under flooding stress. Transcriptome analysis revealed that MT priming promotes seed germination and seedling establishment associated with changes in abscisic acid (ABA), gibberellin (GA), and reactive oxygen species (ROS) biosynthesis and signaling pathways. Real-time quantitative RT-PCR (qRT-PCR) analysis confirmed that MT priming increases the expression levels of GA biosynthesis genes, ABA catabolism genes, and ROS biosynthesis genes while decreasing the expression of positive ABA regulatory genes. Further, measurements of ABA and GA concentrations are consistent with these trends. Following MT priming, quantification of ROS metabolism-related enzyme activities and the concentrations of H2O2 and superoxide anions (O2 -) after MT priming were consistent with the results of transcriptome analysis and qRT-PCR. Finally, exogenous application of GA, fluridone (an ABA biosynthesis inhibitor), or H2O2 partially rescued the poor germination of non-primed seeds under flooding stress. Collectively, this study uncovers the application and molecular mechanisms underlying MT priming in modulating crop seed vigor under flooding stress.

Effect of Gibberellic Acid and Zinc Sulphate on Growth, Yield and Quality of Cucumber (Cucumis sativus L.)

An experiment was conducted at Horticulture Research Field, Department of Horticulture, Naini Agricultural Institute, Faculty of Agriculture, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, during February-May, 2023 on cucumber. The experiment was laid out in factorial randomized block design with twenty treatment combinations and was replicated thrice. The experiment consisted of two factors. Factor H: Hybrids (TMCU-1107, TMCU-1125, TMCU-3112 and Saira-934) and Factor T: Different concentrations of GA₃+ZnSO₄ (T0 - Control (water spray), T1 -GA₃ @100ppm+ZnSO₄ @0.25%, T2 - GA₃ @200ppm+ ZnSO₄ @0.50%, T3 - GA₃ @300ppm+ ZnSO₄ @0.75% and T4 - GA₃ @400ppm+ZnSO₄ @1%). TMCU-1125 recorded significantly higher yield attributes of cucumber over other hybrids in parameters like vine length at 80 DAS (102.6 cm), days to 50% flowering (40), days to 1st harvest (46), number of fruits per plant (11), fruit length (18.4 cm), average fruit weight (237.5 g), average fruit yield per plant (2.6 kg) and ascorbic acid content (0.8 mg/100g). Among different treatments, GA₃ @300ppm+ ZnSO₄ @0.75% resulted in significantly longer vine at 80 DAS (98.4 cm), Days to 50% flowering (43), days to 1st harvest (50), number of fruits per plant (9), fruit length (16.6 cm), average fruit weight (232.0 g), average fruit yield per plant (2.0 kg) and ascorbic acid content (0.5 mg/100g). The interaction effect of T8 (TMCU-1125 + GA₃ @300ppm+ ZnSO₄ @0.75% is best suited for getting higher growth, yield, quality of cucumber.

Geochemistry of Middle Jurassic Coals from the Dananhu Mine, Xinjiang: Emphasis on Sediment Source and Control Factors of Critical Metals

In recent years, coal-type critical metal deposits have become a research hotspot in coal geology. As a major coal-accumulating basin in the Xinjiang area, the Turpan-Hami Basin contains abundant coal resources and has the potential to become a large coal-type critical metal deposit. However, previous studies on the enrichment characteristics of critical metal elements in coal are few and need further research. Based on SEM-EDS, XRF, and ICP-MS experiments, this study investigates the coal petrology, mineralogy, and geochemistry of the No. 22 coal of the Xishanyao Formation from the Dananhu Coal Mine, Xinjiang, to identify the sediment source, depositional environment, and controlling factors of the critical metal elements of the No. 22 coal. The results showed that the Dananhu coals are characterized by a low ash yield, low total sulfur content, high volatile yield, and high inertinite proportions. Quartz, kaolinite, and illite are the main minerals in the coal. Compared with the world’s low-rank coals, Ni, Co, Mo, and Ta are slightly enriched, Li, Rb, Cs, Ba, Tl, Bi, and Ge are depleted, and the concentrations of other trace elements are comparable to the average values of the world’s low-rank coals. The REY of the Dannanhu coals exhibited high fractionation, with its enrichment patterns characterized by the H-type and M-H-type. Although most of the critical metals are not enriched in the Dannanhu coals, the Ga, Zr (Hf), and Nb (Ta) concentrations in the coal ash of the Dannanhu coals have reached the economic cut-off grade and have the potential to be a substitute for rare metal resources. The terrigenous detrital sources of the Dannanhu coals mainly come from the Paleozoic dacite, andesite, and a small amount of granite from the Harik Mountain and Eastern Bogda Mountain in the Turpan-Hami Basin. The Dannanhu coals are generally in a dry and hot depositional environment, with high salinity and weak reduction-oxidation. The low source input and weak reduction-oxidation environment have resulted in low concentrations of critical metal of the No. 22 coal from the Dananhu Coal Mine.

Seaweed-based biostimulants improves quality traits, postharvest disorders, and antioxidant properties of sweet cherry fruit and in response to gibberellic acid treatment

The main aim of this research was to determine whether seaweed-based biostimulants (BIO) have the potential to offset the delaying of fruit maturation and improve fruit quality and antioxidant properties in gibberellic acid (GA3)-treated cherries. Compared to the control, 5 g L−1 BIO applied twice at pit hardening (PH) and straw color (SC) or 3 times at PH, SC, and 1 week before harvest (1WBH) in mid-maturing ‘Bing’ cherries accelerated color development, increased soluble solids content (SSC), titratable acidity, total phenolics (TP), and DPPH radical scavenging activity at harvest. However, these treatments resulted in smaller and softer fruit. For late-maturing ‘Lapins’ cherries, BIO had no effect on fruit coloration, but increased the levels of antioxidants and antioxidant capacity at harvest, especially in 3 applications. Spraying 5 g L−1 BIO 3 times plus a single application of 10 mg L−1 GA3 at PH on ‘Bing’ cherries effectively increased fruit firmness (FF) and size, but showed a strong delaying effect on color development and SSC at harvest, and reduced resistance to disorders after 4 weeks of storage at 0°C if the combination-treated fruit were late harvested. Decreasing GA3 concentration from 10 to 5 mg L−1, increasing BIO concentration from 5 to 10 g L−1, and extending the harvest date by 5 d could impair the delaying effect of GA3 on fruit maturation, restore the normal fruit size, reduce the rates of decay, stem browning (SB), and surface pitting (SP), and maintain high FF and DPPH radical scavenging activity. In conclusion, pre-harvest 3 applications of 10 g L−1 BIO and 5 mg L−1 GA3 once at PH have the potential to curtail the GA3’s inhibition on fruit maturation, extend the harvest window, improve fruit quality, and increase antioxidants and antioxidant capacity in ‘Bing’ cherries.

In vitro and in vivo evaluation of osteogenesis and antibacterial activity of Mg[sbnd]Ga alloys

MgGa alloys are considered highly potential biodegradable materials, owing to its good mechanical properties and appropriate corrosion resistance. However, it is still far from application due to the lack of biological evaluation. In the present study, biocompatibility, osteogenesis and antibacterial activity of extruded Mg–xGa (x = 1 and 5 wt%) alloys were investigated by in vitro cell culture experiments and in vivo implantation. The cell adhesion and proliferation of osteoblast precursor cells (MC3T3-E1) showed the excellent cytocompatibility of Mg–1Ga and poor cytocompatibility of Mg–5Ga. The osteogenic activity was evaluated and revealed that Ga3+ in the Mg–1Ga extract had the ability to enhance osteogenic differentiation through the facilitation of its early stages. In vivo studies in a rat femoral condyle model revealed that both Mg–1Ga and Mg–5Ga significantly promoted new bone formation without causing any adverse effects. Mg–5Ga exhibited a much higher corrosion rate in vivo than Mg–1Ga. Its osteogenic activity was better due to the rapid release of Mg2+ and Ga3+, but this caused premature structural integrity loss. Mg–1Ga and Mg–5Ga released Ga3+ to inhibit E. coli and S. aureus, with antibacterial rate increasing with Ga content. Our studies demonstrate that Mg–Ga alloys have the potential to be used as osteogenic and antibacterial implant materials. Statement of significanceThis study evaluates the biocompatibility, osteogenesis, and antibacterial activity of Mg–Ga alloys, which are promising biodegradable materials for medical applications. The study finds that Mg–1Ga exhibits excellent cytocompatibility and promotes osteogenic differentiation, facilitating the early stages of osteoblast precursor cell development. In vivo studies in a rat femoral condyle model reveal that Mg–1Ga and Mg–5Ga significantly promote new bone formation without causing any adverse effects. The antibacterial activity of both alloys is evaluated against E. coli and S. aureus, with the inhibition rate increasing with Ga content. These findings suggest that Mg–Ga alloys have the potential to serve as osteogenic and antibacterial implant materials, providing significant insights into the development of novel biomedical implants.

Ga/Al ratio induced afterglow behavior of Ce3+:GAGG scintillation ceramics

This work investigated the optical and scintillation properties of cerium-doped gadolinium aluminum gallium garnet (Ce:GAGG) ceramics with different gallium-to-aluminum (Ga/Al) ratios. The optical transmittance, fluorescence spectra, fluorescence lifetime, light yield, scintillation decay, and afterglow characteristics of the ceramic samples were studied. The experimental results reveal that the decay time of Ce:GAGG ceramic is significantly decreased with the increase of Ga content. The mean decay time of 60 ns is achieved when the Ga/Al ratio is 3:2 in our experiment. The light yield of ceramics varies from 12,140 to 44,825 ph/MeV with the change of Ga content, and the highest light yield is achieved when the Ga/Al ratio is 2.4:2.6. Noteworthy fluctuation in the afterglow performance is affected by the Ga content significantly. The afterglow intensity of the sample with Ga/Al = 2:3 is approximately 0.5 % of its initial intensity after the X-ray excitation was turned off for 5 s. The formation mechanism of defects which is related with the afterglow behaviors were investigated and discussed.

Short-Range Order in Gallium Solid Solutions in α-Iron

Short-range order in soft magnetic FeGa alloys containing from 3 to 25 at % Ga was studied using nuclear gamma resonance (Mössbauer) spectroscopy. The Mössbauer spectra were analyzed via fitting with subspectra corresponding to different configurations of the neighborhoods of the Fe atoms with Ga in the first and second coordination shells. It has been shown that in samples of alloys containing from 3 to 17 at % gallium, the short-range order is almost independent of the heat treatment conditions (quenching from a paramagnetic state or exposure in a ferromagnetic state) and is characterized by the presence of pairs of Ga atoms in the position of the second neighbors (B2-type clusters). At a Ga content of 17 to 21 at %, the portion of B2 clusters turns out to be significantly higher after quenching than after annealing, which correlates with the observed effect of heat treatment on the magnitude of magnetostriction. As the Ga concentration (21–25 at %) further increases, the observed features in the distribution of Ga atoms indicate the appearance and growth of D03 phase regions.

Automated Imaging to Evaluate the Exogenous Gibberellin (Ga3) Impact on Seedlings from Salt-Stressed Lettuce Seeds.

Salinity stress is a common challenge in plant growth, impacting seed quality, germination, and general plant health. Sodium chloride (NaCl) ions disrupt membranes, causing ion leakage and reducing seed viability. Gibberellic acid (GA3) treatments have been found to promote germination and mitigate salinity stress on germination and plant growth. 'Bauer' and 'Muir' lettuce (Lactuca sativa) seeds were soaked in distilled water (control), 100 mM NaCl, 100 mM NaCl + 50 mg/L GA3, and 100 mM NaCl + 150 mg/L GA3 in Petri dishes and kept in a dark growth chamber at 25 °C for 24 h. After germination, seedlings were monitored using embedded cameras, capturing red, green, and blue (RGB) images from seeding to final harvest. Despite consistent germination rates, 'Bauer' seeds treated with NaCl showed reduced germination. Surprisingly, the 'Muir' cultivar's final dry weight differed across treatments, with the NaCl and high GA3 concentration combination yielding the poorest results (p < 0.05). This study highlights the efficacy of GA3 applications in improving germination rates. However, at elevated concentrations, it induced excessive hypocotyl elongation and pale seedlings, posing challenges for two-dimensional imaging. Nonetheless, a sigmoidal regression model using projected canopy size accurately predicted dry weight across growth stages and cultivars, emphasizing its reliability despite treatment variations (R2 = 0.96, RMSE = 0.11, p < 0.001).

Elicitors directed in vitro growth and production of stevioside and other secondary metabolites in Stevia rebaudiana (Bertoni) Bertoni

Stevia rebaudiana (stevia) is a plant in the Asteraceae that contains several biologically active compounds including the antidiabetic diterpene glycosides (e.g. stevioside, rebaudioside and dulcoside) that can serve as zero-calorie sugar alternatives. In this study, an elicitation strategy was applied using 5% polyethylene glycol (PEG), sodium chloride (NaCl; 50 and 100 mM) and gibberellic acid (2.0 and 4.0 mg/L GA3) to investigate their effect on shoot morphogenesis, and the production of phenolics, flavonoids, total soluble sugars, proline and stevioside, as well as antioxidant activity, in shoot cultures of S. rebaudiana. Herewith, the media supplemented with 2 mg/L and 4 mg/L GA3 exhibited the highest shooting response (87% and 80%). The augmentation of lower concentrations of GA3 (2 mg/L) in combination with 6-benzylaminopurine (BAP) resulted in the maximum mean shoot length (11.1 cm). The addition of 100 mM NaCl salts to the media led to the highest observed total phenolics content (TPC; 4.11 mg/g-DW compared to the control 0.52 mg/g-DW), total flavonoids content (TFC; 1.26 mg/g-DW) and polyphenolics concentration (5.39 mg/g-DW) in shoots cultured. However, the maximum antioxidant activity (81.8%) was observed in shoots raised in media treated with 50 mM NaCl. The application of 2 mg/L of GA3 resulted in the highest accumulation of proline (0.99 μg/mL) as compared to controls (0.37 μg/mL). Maximum stevioside content (71 µL/mL) was observed in cultures supplemented with 100 mM NaCl and 5% PEG, followed by the 4 mg/L GA3 treatment (70 µL/mL) as compared to control (60 µL/mL). Positive correlation was observed between GA3 and stevioside content. Notably, these two compounds are derived from a shared biochemical pathway. These results suggest that elicitation is an effective option to enhance the accumulation of steviosides and other metabolites and provides the groundwork for future industrial scale production using bioreactors.

Degradation Behaviors of Polylactic Acid, Polyglycolic Acid, and Their Copolymer Films in Simulated Marine Environments.

Poly(lactic acid) (PLA) and poly(glycolic acid) (PGA) are extensively studied biodegradable polymers. However, the degradation behavior of their copolymer, poly(lactic-co-glycolic acid) (PLGA), in marine environments has not yet been confirmed. In this study, the changes in macroscopic and microscopic morphology, thermal properties, aggregation, and chemical structure of PLA, PGA, PLGA-85, and PLGA-75 (with 85% and 75% LA content) in simulated marine environments were investigated. Results revealed that degradation occurred through hydrolysis of ester bonds, and the degradation rate of PGA was faster than that of PLA. The amorphous region degraded preferentially over the crystalline region, leading to cleavage-induced crystallization and decreased thermal stability of PLA, PLGA-85, and PLGA-75. The crystal structures of PLGAs were similar to those of PLA, and the higher GA content, the faster was the degradation rate. This study provides a deeper understanding of the seawater degradation behaviors of PLA, PGA, and their copolymers, and provides guidance for the preparation of materials with controllable degradation performance.

The contribution of Ca and Mg to the accumulation of amino acids in maize: from the response of physiological and biochemical processes

BackgroundThe quality of maize kernels is significantly enhanced by amino acids, which are the fundamental building blocks of proteins. Meanwhile, calcium (Ca) and magnesium (Mg), as important nutrients for maize growth, are vital in regulating the metabolic pathways and enzyme activities of amino acid synthesis. Therefore, our study analyzed the response process and changes of amino acid content, endogenous hormone content, and antioxidant enzyme activity in kernels to the coupling addition of sugar alcohol-chelated Ca and Mg fertilizers with spraying on maize.Result(1) The coupled addition of Ca and Mg fertilizers increased the Ca and Mg content, endogenous hormone components (indole-3-acetic acid, IAA; gibberellin, GA; zeatin riboside, ZR) content, antioxidant enzyme activity, and amino acid content of maize kernels. The content of Ca and Mg in kernels increased with the increasing levels of Ca and Mg fertilizers within a certain range from the filling to the wax ripening stage, and significantly positively correlated with antioxidant enzyme activities. (2) The contents of IAA, GA, and ZR continued to rise, and the activities of superoxide dismutase (SOD) and catalase (CAT) were elevated, which effectively enhanced the ability of cells to resist oxidative damage, promoted cell elongation and division, and facilitated the growth and development of maize. However, the malondialdehyde (MDA) content increased consistently, which would attack the defense system of the cell membrane plasma to some extent. (3) Leucine (LEU) exhibited the highest percentage of essential amino acid components and a gradual decline from the filling to the wax ripening stage, with the most substantial beneficial effect on essential amino acids. (4) CAT and SOD favorably governed essential amino acids, while IAA and MDA negatively regulated them. The dominant physiological driving pathway for the synthesis of essential amino acids was “IAA-CAT-LEU”, in which IAA first negatively drove CAT activity, and CAT then advantageously controlled LEU synthesis.ConclusionThese findings provide a potential approach to the physiological and biochemical metabolism of amino acid synthesis, and the nutritional quality enhancement of maize kernel.

Selective photochemical oxidation of sulfides by Gallium and Sulfur Co-Modified TiO2/g-C3N4 Nanocomposites as catalyst

In this study, with the objective of promoting the oxidation of sulfides, a distinctive photocatalyst was synthesized by incorporating Ga- and S-co-doped TiO2 onto graphitic carbon nitride (g-C3N4). Under visible light irradiation, the composites demonstrated enhanced photocatalytic performance in comparison to g-C3N4 and TiO2/g-C3N4. The nanocomposite catalyst displayed a remarkable enhancement in photocatalytic activity, benefiting from the creation of a Z-scheme heterojunction by combining TiO2 and g-C3N4, as well as the presence of electron trap centers, efficient photogenerated electron transfer, improved charge carrier separation, and extended optical absorption in the visible light range. To optimize the performance, the substitution contents of Ga and S (GaxSy@TiO2-g-C3N4) were varied, where the values of x and y were set at 5 % and 10 %, respectively. Notably, Based on the obtained results, it was observed that the Ga5.0S10.0@TiO2-g-C3N4 sample displayed the highest yield when subjected to visible-light irradiation, making it the most effective and optimal sample. The findings of this study offer a fresh perspective on the synergistic effect of dopant photocatalysts in the oxidation of organic compounds. This work presents a novel approach for the development of highly efficient photocatalysts capable of effectively oxidizing organic compounds.

Different Phenotypic, Photosynthetic, and Physiological Responses to Flooding between Q. nuttallii and Q. palustris.

Flooding stress is an increasingly serious problem in wetlands, often affecting large areas of crops and timber production areas. The current study aimed to explore the species differences in responses to flooding stress between Q. nuttallii and Q. palustris in an outdoor environment. All the tested plants survived after a 60-day flooding treatment that left 5 cm of water above the soil surface. This suggests that the two species are flood-tolerant, so they can be applied in the construction of riparian protection forests and wetland restoration. Compared with control conditions, flooding treatment significantly decreased seedling height and diameter and the Pn, Gs, Tr, Fv/Fm, ABS/CSm, TR0/CSm, ET0/CSm, RE0/CSm, IAA, and GA3 content and significantly increased the content of MDA, H2O2, soluble sugars, SOD, POD, ADH, ABA, and JA. Under control conditions, Q. nuttallii showed significantly greater growth and photosynthetic capability than Q. palustris. In contrast, Q. palustris exhibited less inhibition of growth and photosynthesis, oxidative stress levels, and antioxidant enzyme activities than Q. nuttallii under flooding conditions. The findings indicate that Q. palustris has better defense mechanisms against the damage caused by flooding stress than Q. nuttallii. Q. nuttallii was more sensitive and responsive to flooding than Q. palustris.

Influence of {Ce3+ – Mg2+} pairs on the photo- and thermally stimulated luminescence of Mg2+ co-doped Gd3(Ga,Al)5O12:Ce single crystals

Single crystals of Gd3(Ga,Al)5O12:Ce,Mg with different concentration of Mg2+ ions varying from 0 to 0.029 at.% are investigated by the X-ray diffraction, steady-state and time-resolved photoluminescence, and thermally stimulated luminescence (TSL) methods in a wide temperature range (77–510 K). The origin and structure of the luminescence centers are considered. The influence of Mg2+ ions on the structure of the Ce3+-related excited state, the processes taking place in this state, and the TSL characteristics is clarified. At low temperatures, the photoluminescence optical quenching in close {Ce3+ - Mg2+} pairs is found to be responsible for the light yield reduction accompanied with the acceleration of the luminescence decay kinetics. At room temperature, the luminescence quenching can be additionally caused by the thermal ionization of the 5d1 excited state of Ce3+ ion, whose probability increases with the increasing Ga content. The conclusion is made that in order to create the fast scintillator with the maximum light yield, the concentration of intrinsic crystal lattice defects in Gd3(Ga,Al)5O12:Ce,Mg should be minimized, the optimum composition of the host should be chosen, and the balance between the concentrations of the doped Mg2+ and Ce3+ ions should be optimised.