Progress in phosphorylation of natural products.

Natural medicines are a valuable resource for the development of new drugs. However, factors such as low solubility and poor bioavailability of certain constituents have hindered their efficacy and potential as pharmaceuticals. Structural modification of natural products has emerged as an important research area for drug development. Phosphorylation groups, as crucial endogenous active groups, have been extensively utilized for structural modification and development of new drugs based on natural molecules. Incorporating phosphate groups into natural molecules not only enhances their stability, bioavailability, and pharmacological properties, but also improves their biological activity by altering their charge, hydrogen bonding, and spatial structure. This review summarizes the phosphorylation mechanism, modification approaches, and biological activity enhancement of natural medicines. Notably, compounds such as polysaccharides, flavonoids, terpenoids, anthraquinones, and coumarins exhibit increased antioxidation, anticancer, antiviral, immune regulatory, Antiaging, enzyme inhibition, bacteriostasis, liver protection, and lipid-lowering effects following phosphorylation modification.

PGC7 regulates H3K27me3 modification by inhibiting the interaction of YY1 with PRC2.

Primordial germ cell 7 (PGC7)(Dppa3 or Stella) is a small inherently disordered protein that is mainly expressed in oocytes and plays a vital role in the regulation of DNA methylation reprogramming in imprinted loci through interaction with other proteins. Most of PGC7-deficient zygotes are blocked at two-cell stage with an increased tri-methylation at lysine 27 of histone H3 (H3K27me3) level in the nucleus. Our previous work has indicated that PGC7 interacts with yin-yang1 (YY1) that is essential for the recruitment of enhancer of zeste homolog 2 (EZH2)-containing Polycomb repressive complex 2 (PRC2) to H3K27me3 modification sites. Here, we found that the presence of PGC7 weakened the interaction between YY1 and PRC2 without disrupting the assembly of core subunits of the PRC2 complex. In addition, PGC7 promoted AKT to phosphorylate serine 21 of EZH2, resulting in inhibition of EZH2 activity and the dissociation of EZH2 from YY1, thereby decreasing H3K27me3 level. In zygotes, the PGC7-deficient and AKT inhibitor MK2206 both promoted EZH2 to enter the pronuclei but without disturbing the subcellular localization of YY1 and caused an increase in the level of H3K27me3 in the pronuclei, as well as inhibition of the expression of zygote-activating genes regulated by H3K27me3 in two-cell embryos. In summary, PGC7 could affect zygotic genome activation during early embryonic development by regulating the level of H3K27me3 through regulation of PRC2 recruitment, EZH2 activity, and subcellular localization.NEW & NOTEWORTHY PGC7 and YY1 interaction inhibits recruitment of PRC2 by YY1. PGC7 promotes AKT and EZH2 interaction to increase pEZH2-S21 level, which weakens YY1 and EZH2 interaction, thereby decreasing H3K27me3 level. In zygotes, the PGC7-deficient and AKT inhibitor MK2206 promote EZH2 to enter the pronuclei, and increase H3K27me3 level in the pronuclei, as well as inhibition of the expression of zygote-activating genes regulated by H3K27me3 in two-cell embryos, which ultimately affects early embryo development.

Optimal allocation of agricultural water resources in Yanghe watershed considering blue water to green water ratio.

BACKGROUND: Yanghe Watershed has low annual rainfall, uneven spatial and temporal distribution, extreme shortage of water resources in some areas. The contradiction between supply and demand of water for agricultural production is prominent and the expected production value cannot be achieved. Therefore, it is necessary to investigate the supply and demand of agricultural water resources and the impact of green water on agricultural crops in Yanghe Watershed. RESULTS: This article proposes a new crop economic model for increasing the green-water footprint to blue-water footprint ratio (GWF:BWF) in accordance with the regional characteristics, alleviating agricultural water shortage in irrigation areas, optimizing water resource allocation, and achieving sustainable agricultural development. The proposition is based on a study of five crops in eight districts and counties in the Yanghe River watershed. By combining the economic model F with a crop water production function, we achieved 89.3%, 88.9%, 97.1%, 81.5%, and 87.0% of the optimal water demands of the five crops, respectively, and effectively improved the underground irrigation of crops and the water resource utilization efficiency. CONCLUSION: The GWF:BWF threshold interval was subsequently selected based on the temporal changes in the BWF and GWF in the study area. This enabled significant reduction of the planting area of blue-water crops and increase in the proportion of green-water crops, while also improving the agricultural economy of the Yanghe Watershed. The proposed model promises to afford enhanced management of agricultural irrigation areas that experience rainfall shortage. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Driving factors for decoupling water resources ecological footprint and economic growth in water-deficient cities dominated by agriculture.

To explore the key factors and specific thresholds of water resources limiting economic development, and to provide technical support for water resources management in cities dominated by agriculture similar to Zhangjiakou. We used the Tapio elastic decoupling method to quantitatively evaluate the decoupling relationship between the water resources ecological footprint (WEF) and economic growth. Then the logarithmic mean Divisia index (LMDI) and mathematical statistics are used to identify the key factors and threshold effects. The results show a significant decreasing trend in the WEF and obvious spatial differences in Zhangjiakou between 2006 and 2015, with agricultural ecological footprint dominating all districts and counties (77.54 ± 14.35%). The changes in technological effect are a contributing factor to the decoupling between the WEF and the economy in Zhangjiakou, while the economic effect is the main restricting factor. In particular, there is a high correlation between the WEF and the number of water-saving irrigation machines and the total power of agricultural machinery. According to the findings, for water-scarce cities such as Zhangjiakou, where agriculture is the primary focus, it is suggested that increasing the number of agricultural machinery can effectively alleviate the problem of water scarcity constraining economic development.

Improved growth of bait microalgae Isochrysis and aquacultural wastewater treatment with mixotrophic culture.

This research of mixotrophic microalgae Isochrysis 3011 with glycerol was combined with the treatment of aqua-cultural wastewater, different initial concentrations, and optimized light intensities. The algae growth rate, removal efficiencies of total nitrogen (TN) and total phosphorus (TP) were determined. Results showed that the suitable initial concentration was 0.4 g L-1, and the optimum light intensity was 60 µmol m-2 s-1. The growth of the mixotrophic group was better than that of the autotrophic culture. The biomass yield of the mixotrophic group with glycerol was 0.17 g L-1 d-1, and the removal rates of TN and TP were 73.39% and 95.61%, respectively. The content of total lipid and total protein in mixotrophic group were higher than the values of the autotrophic group. This indicates that aquaculture wastewater treatment with mixotrophic bait microalgae can obtain superior micro-algal biomass, which is also a potential technology for wastewater utilization and ecological protection.

Influence of the Bearing Thermal Deformation on Nonlinear Dynamic Characteristics of an Electric Drive Helical Gear System.

Based on the statics and quasi-statics analysis methods, the thermal deformation calculation model of a deep-groove ball bearing was constructed for the helical gear transmission system of a high speed electric drive, and the radial and axial bearing stiffness values of the bearing were calculated under the thermal deformation in this study. The obtained radial and axial stiffness values were introduced into the established dynamics model of helical gear system, and the influence of changed bearing stiffness, resulting from the thermal deformation, on the nonlinear dynamic characteristics of gear pair was analyzed using the Runge-Kutta method. The results show that the axial and radial deformations of bearing occur due to the increase of working speed and temperature, in which the axial stiffness of bearing is improved but the radial stiffness is reduced. The decreasing degree of axial stiffness and the increasing degree of radial stiffness decrease with the gradually increasing working rotational speed. When considering the influence of thermal deformation on the bearing stiffness, the helical gear system will have nonlinear behaviors, such as single periodic, double periodic, and chaotic motion with the change of working speed. Therefore, in order to improve the nonlinear dynamic characteristics of high speed electric drive gear systems, the influence of bearing stiffness change on the dynamic performance of a gear system should be considered in the industrial applications.

Dewaterability and energy consumption model construction by comparison of electro-dewatering for industry sludges and river sediments.

Electro-dewatering (EDW) is an emerging technology for improved sludge/sediment dewatering enabling subsequent cost effective treatment for toxicity and pathogenic reduction if required and/or disposal, but the effects of sediment/sludge properties on the efficacy of EDW remain unclear. Here we investigate EDW in the absence of chemical conditioning which can result in secondary pollution. The influence of sediment/sludge volatile solids content (VS), electrical conductivity (EC), pH and zeta potential (ζ), on mechanical and electrical behaviors determining dewaterability and energy consumption (PE) was investigated. Optimization of EDW parameters increased the final solids content (DSf) from 40 wt% to more than 55 wt% for river sediment, while the solids content in municipal sludge was only increased from 10 wt% to 15-20 wt%. Multiple linear regression and statistical analysis showed that electro-dewatering performance is primarily affected by VS and PE is mainly affected by EC. A theoretical basis for engineering design and selection of operational parameters for sludge/sediment electro-dewatering is provided by this study.

Using stable nitrogen and oxygen isotopes to identify nitrate sources in the Lancang River, upper Mekong.

The Lancang River in China is the headwater of the Mekong River. The impacts of reservoirs on the water, sediment and nutrient trapping in the Lancang River have attracted considerable attention, both locally and abroad. In this research, watershed-scale nitrogen load and nitrate sources along the Lancang River upstream in free-flowing reaches (FFRs) and downstream regulated reaches (RRs) were analyzed using stable nitrogen and oxygen isotopes. The results showed that the nitrogen nutrient (TN, NO3- and NH4+) concentration increased from upstream to downstream along the Lancang River, and the highest values come from large-scale urban samples rather than the reservoirs. Compared to other large rivers in China, such as the Yangtze River, Yellow River and Yalu Tsangpo River, nitrogen nutrient content in the Lancang River is at low level. The nitrate concentration ranged from 0.14 mg/L to 0.63mg/Land increased significantly downstream. The isotopic values ranged from 2.8‰ to 5.2‰ for δ15N-NO3- and from 4‰ to 8.5‰ for δ18O-NO3- along the river, and the δ15N-NO3- value rose significantly downstream. According to the nitrogen and oxygen isotope approach, soil organic nitrogen mineralization was the main source of the nitrate with an average of 51% contribution; domestic sewage was the second largest contributor with an average of 33% but increase downstream, likely due to the significantly larger population in the downstream region. Furthermore, the nitrate concentration decreased and δ15N- and δ18O-NO3- enriched in the Nuozhadu reservoir, indicating that the reservoir may enhance nitrate consumption and reduce nitrogen pollution to downstream reaches. The results provide a perspective of nitrogen nutrient for the trans-border river management and more insight researches are called for understanding the controversial nutrient transport topic in this region.

Retinoic Acid Induces Differentiation of Mouse F9 Embryonic Carcinoma Cell by Modulating the miR-485 Targeting of Abhd2.

Retinoic acid (RA) plays a key role in pluripotent cell differentiation. In F9 embryonic carcinoma cells, RA can induce differentiation towards somatic lineages via the Ras-extracellular signal-regulated kinase (Ras/Erk) pathway, but the mechanism through which it induces the Erk1/2 phosphorylation is unclear. Here, we show that miR-485 is a positive regulator that targets α/ß-hydrolase domain-containing protein 2 (Abhd2), which can result in Erk1/2 phosphorylation and triggers differentiation. RA up-regulates miR-485 and concurrently down-regulates Abhd2. We verified that Abhd2 is targeted by miR-485 and they both can influence the phosphorylation of Erk1/2. In summary, RA can mediate cell differentiation by phosphorylating Erk1/2 via miR-485 and Abhd2.

Ca removal and Mg recovery from flue gas desulfurization (FGD) wastewater by selective precipitation.

Selective removal of Ca and recovery of Mg by precipitation from flue gas desulfurization (FGD) wastewater has been investigated. Thermodynamic analysis of four possible additives, Na2CO3, Na2C2O4, NaF and Na2SO4, indicated that both carbonate and oxalate could potentially provide effective separation of Ca via precipitation from Mg in FGD wastewater. However, it was found experimentally that the carbonate system was not as effective as oxalate in this regard. The oxalate system performed considerably better, with Ca removal efficiency of 96% being obtained, with little Mg inclusion at pH 6.0 when the dosage was ×1.4 the stoichiometric requirement. On this basis, the subsequent recovery process for Mg was carried out using NaOH with two-step precipitation. The product was confirmed to be Mg(OH)2 (using X-ray diffraction and thermo gravimetric analysis) with elemental analysis suggesting a purity of 99.3 wt.%.

[Causes of succession of planktonic algae in Shennong bay of Three Gorges Reservoir in spring in 2014].

Objective: Algal blooms occurred in some sections of Shennong bay after impounding of Three Gorges Reservoir. Methods: Related environmental and hydrodynamic factors were monitored during the period of algal blooming season in 2014 (March 20, April 13, May 23) in Shennong bay, Three Gorges Reservoir. To study succession of planktonic algae, water stable coefficient, euphotic depth and mixed layer depth were used to analyze stratification and hydrodynamic characteristics. Results: We identified 6 phyla, 38 species (genera) planktonic algae. The sensitive area of algal bloom was at SN05 (677.677×105 cells/L) and SN06 (716.761×105 cells/L), and the planktonic algae biomass during this period was significantly different (ANOVA, p<0.05). Moderate water temperature, adequate nutrients, weak stratification and poor mixing promoted the rapid growth and breakout of the diatom bloom with Cyclotella spp. as the dominant species in March. Further increase of water temperature, stronger stratification and decrease of dissolved silicate and mixing layer restricted the diatom growth. Chlorella spp. and Chlamydomonas spp. grew better in shallow mixed layer with rich nutrients and evident stratification. Then Chlorophycean bloom broke out with Chlorella spp. as the dominant species and Chlamydomonas spp. the next-dominant species. High biomass maintained in April. In May, algal bloom gradually vanished due to sharp fluctuation of water level and increase of velocity. Monitored maximum water velocity was 0.1141 m/s at 2 m depth, exceeded an optimal flow rate perfect for growth of planktonic algae. Conclusion: Stratification and hydrodynamic characteristics had important effect on planktonic algae under the condition of adequate nutrients. Velocity became the main factor that inhibited the growth of algae in Shennong bay in pre-flood falling stage of the Three Gorges Reservoir.

Functionalization of amides via copper-catalyzed oxyalkylation of vinylarenes and decarboxylative alkenylation of sp3 C-H.

An efficient protocol was developed to prepare a series of derivatives from amides by copper-catalyzed oxyalkylation of vinylarenes and decarboxylative alkenylation of sp(3) C-H. This method is simple, practical, and inexpensive.

Nutrient spatial pattern of the upstream, mainstream and tributaries of the Three Gorges Reservoir in China.

A comprehensive monitoring program was conducted to investigate the nutrient spatial pattern in the mainstream of the Yangtze River from the Baihetan Dam down to the Three Gorges Dam located at the upper region of the Yangtze River in China. Samples were taken from 33 different sites from July 30 to August 19, 2011. The nutrient patterns of the three representative tributaries of the Three Gorges Reservoir (TGR)--the Modao, the Daning, and the Xiangxi Rivers--were also investigated. The results show that the mainstream of the TGR has a higher concentration of nitrogen and a lower concentration of phosphorus than that of the upper mainstream before the TGR. Moreover, it was found that nitrate-nitrogen (NO3-N) is the main nitrogen component, while particulate phosphorus predominates the total phosphorus (TP). It was found that the three representative tributaries of the TGR have lower total nitrogen (TN) concentrations compared to the corresponding sections of the mainstream TGR. Based on the nutrient spatial pattern, the nutrient flux was calculated. The total fluxes of TN, NO3-N, TP, and orthophosphate (PO4-P) from the upstream reach into the TGR are 2,155.06, 1,674.97, 212.98, and 83.42 t day(-1), respectively. The amount of nutrients imported from the TGR into its tributaries is more than the amount exported. It was determined that the Xiangxi River has the largest net rate of imported nitrogen at 7.66 t day(-1), whereas the Daning River has the largest net rate of imported phosphorus at 1.75 t day(-1). In addition, compared with the nutrients imported from the TGR into its tributaries, the nutrient flux from the upstream reach into the TGR contributes approximately less than 3 %.

Simultaneous Determination of Chemical Oxygen Demand, Total Nitrogen, Ammonia, and Phosphate in Surface Water Based on a Multielectrode System.

A technique for monitoring chemical oxygen demand (COD), total nitrogen (TN), ammonia (N-NH4), and phosphate (P-PO4) in surface water with a targeted signal multielectrode system (Cu, Ir, Rh, Co(OH)2, and Zr(OH)4 electrodes) is proposed for the first time. Each water quality index is specifically detected by at least two electrodes with distinct selectivity sensing mechanisms. Cyclic voltammetry and electrochemical impedance measurements are employed for multidimensional signal acquisition, complemented by normalization and Least Absolute Shrinkage and Selection Operator (LASSO) for principal feature extraction and dimension reduction. Multiple linear regression (MLR), partial least-squares (PLS), and eXtreme Gradient Boosting (XGBoost) were employed to evaluate the established prediction model. The precisions of the multielectrode system are ±10%/±5 ppm of COD, ±10%/±0.2 ppm of TN, ±5%/±0.1 ppm of N-NH4, and ±5%/±0.01 ppm of P-PO4. The analysis time of the multielectrode system is reduced from hours to minutes compared with traditional analysis, without any sample pretreatment, facilitating continuous online monitoring in the field. The developed multielectrode system offers a feasible strategy for online in situ monitoring of surface water quality.

Robust (hydrogen) phosphate sensing based on reversible redox of cobalt(II) hydroxide.

Response mechanism of the electrode is elucidated in terms of (hydrogen) phosphate accelerating oxidation of CoII to CoIII for the first time. Cyclic voltammetric techniques in conjunction with XRD, XPS and Raman characterizations have demonstrated unambiguously the response of cobalt (II) hydroxide electrode involves a phosphate and hydrogen ion dependent charge transfer process. Phosphate ions induce Co(OH)2 transformed into CoOOH within interlayer adsorption and restored the initial state after reduction. Meanwhile, the in common structural between Co(OH)2 and CoOOH prevents extensive structural convertibility upon cycling, result in the advantage of reversibility in phase transformation. Demonstrated sustainable technique offered the determination of phosphate with robust reproducibility (1000 cycles), long storage stability (6 months) and selectivity (potential interference: Cl-, NO3-, SO42- and HCO3-), achieving a detection limit of 5 × 10-8 M over a wide linear range up to 1.28 mM. Presented work provided insights into the unique selectivity towards phosphate in cobalt based sensors, which may inspire the rational design of Co(OH)2-based electrodes with superior electrochemical performance or extended applications.

Evolution of self-assembled amphiphilic colloidal particles in strong-flavor Chinese baijiu.

This study proposed the evolution of self-assembled amphiphilic colloidal particles in Strong-Flavor (SF) Baijiu based on Ostwald ripening for the first time. The evolution process occurs in two stages: disordered amphiphilic molecules self-assemble into small colloidal particles and subsequently undergo Oswald ripening to form larger hydrophobic particles. Microscopic observations revealed the average size of oil-like spherical colloidal particles in Baijiu increased from 1.86 µm to 2.96 µm while the number of particles decreased by 39.50% during the 16-year cellaring process of SF Baijiu, consistent with the particle size trend observed via laser scattering. During fusion process, the charge-to-mass ratio of positively charged colloidal particles decreased, leading ζ-potential decreased from 23.7 mV to 4.66 mV within 16 years of storage. The electrochemical impedance spectroscopy approach tracked the unidirectional variation in the dielectric constant during evolution of SF Baijiu, reflecting the gradual expansion of colloidal particles, which aligns with the evolution trend observed in molecular dynamics simulations. By integrating direct microscopic observations of amphiphilic colloidal particles with electrochemical techniques, the evolution of Baijiu samples is capable to be evaluated in-situ, laying the foundation for intelligent Baijiu aging monitoring technology.

Fatigue Strength Improvement of Laser-Directed Energy Deposition 316L Stainless Steel with In Situ Ultrasonic Rolling by Preliminary Investigation.

In this study, to improve the fatigue strength of the LDED (laser-directed energy deposition) 316L stainless steel, an in situ ultrasonic rolling technology is developed to assist the laser-directed energy deposition process (LDED-UR). The microstructural characteristics and fatigue behavior are comprehensively discussed. The results show that the average size of pores of the LDED-UR alloy is about 10.2 µm, which is much smaller than that of the LDED alloy (34.1 µm). Meanwhile, the density of the LDED alloy is also enhanced from 98.26% to 99.27% via the in situ ultrasonic rolling. With the application of the in situ ultrasonic rolling, the grains are transformed into fully equiaxed grains, and their average grain size is greatly reduced from 84.56 µm to 26.93 µm. The fatigue limit of the LDED-UR alloy is increased by 29% from 210 MPa (LDED alloy) to 270 MPa, which can be ascribed to the decreased porosity and the fine grains. In particular, the crack initiation site of the LDED alloy is located at the surfaces, while it is nucleated from the sub-surface for the LDED-UR alloy. This is mainly attributed to the compression residual stress induced by the in situ ultrasonic rolling. This research offers a valuable understanding of the failure mechanisms in additively manufactured metals, guiding the development of effective strategies to improve their fatigue threshold under severe operating conditions.

Methane dynamics altered by reservoir operations in a typical tributary of the Three Gorges Reservoir.

Substantial nutrient inputs from reservoir impoundment typically increase sedimentation rate and primary production. This can greatly enhance methane (CH4) production, making reservoirs potentially significant sources of atmospheric CH4. Consequently, elucidating CH4 emissions from reservoirs is crucial for assessing their role in the global methane budget. Reservoir operations can also influence hydrodynamic and biogeochemical processes, potentially leading to pronounced spatiotemporal heterogeneity, especially in reservoirs with complex tributaries, such as the Three Gorges Reservoir (TGR). Although several studies have investigated the spatial and temporal variations in CH4 emissions in the TGR and its tributaries, considerable uncertainties remain regarding the impact of reservoir operations on CH4 dynamics. These uncertainties primarily arise from the limited spatial and temporal resolutions of previous measurements and the complex underlying mechanisms of CH4 dynamics in reservoirs. In this study, we employed a fast-response automated gas equilibrator to measure the spatial distribution and seasonal variations of dissolved CH4 concentrations in XXB, a representative area significantly impacted by TGR operations and known for severe algal blooms. Additionally, we measured CH4 production rates in sediments and diffusive CH4 flux in the surface water. Our multiple campaigns suggest substantial spatial and temporal variability in CH4 concentrations across XXB. Specifically, dissolved CH4 concentrations were generally higher upstream than downstream and exhibited a vertical stratification, with greater concentrations in bottom water compared to surface water. The peak dissolved CH4 concentration was observed in May during the drained period. Our results suggest that the interplay between aquatic organic matter, which promotes CH4 production, and the dilution process caused by intrusion flows from the mainstream primarily drives this spatiotemporal variability. Importantly, our study indicates the feasibility of using strategic reservoir operations to regulate these factors and mitigate CH4 emissions. This eco-environmental approach could also be a pivotal management strategy to reduce greenhouse gas emissions from other reservoirs.

Copper-catalyzed methyl esterification reactions via C-C bond cleavage.

The highly effective synthesis of methyl esters from benzylic alcohols, aldehydes, or acids via copper-catalyzed C-C cleavage from tert-butyl hydroperoxide is reported in this paper for the first time. Our protocol is easily accessible and practical, making it a possible supplement for the traditional way.

In vitro bioactivity and degradability of ß-tricalcium phosphate porous scaffold fabricated via selective laser sintering.

Porous scaffolds consisting of ß-tricalcium phosphate (ß-TCP) were successfully fabricated via selective laser sintering. The scaffolds had a controlled microstructure and totally interconnected porous structure. The microstructure and mechanical properties were studied. The bioactivity and degradability of scaffolds were evaluated through the simulated body fluid (SBF) cultivation experiment. The formation of a biologically active carbonate apatite layer on the surface after immersion in SBF was demonstrated using scanning electron microscope, energy dispersive X-ray, and Fourier transform infrared spectroscopy. Fast nucleation and growth of the carbonate apatite crystals were observed to occur all through the specimen surfaces. The phenomenon was explained in terms of the distribution and dispersion of inorganic phases in the scaffolds and the ionic activity products of the apatite in the SBF. The calculation results of weight loss and Ca/P molar ratio also suggest the good bioactivity and degradability of the scaffolds. These indicate that the ß-TCP porous ceramic scaffold is a potential candidate scaffold for bone tissue engineering.