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As a traditional Chinese medicine, Eupatorium lindleyanum DC. has an effect on resolving phlegm, relieving cough, and relieving asthma. In this study, an ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry method was established for qualitative analysis of Eupatorium lindleyanum. Besides, we developed an ultra high performance liquid chromatography with triple quadrupole tandem mass spectrometry method in positive and negative multiple reaction monitor modes for the quantitative analysis of 27 chemical constituents from 19 different batches of Eupatorium lindleyanum. The methodology validated linearity, intraday and interday precision, stability, repeatability, and recovery. The results showed that there were some differences in different batches of Eupatorium lindleyanum, which might be attributed to the influence of different growth environments and climatic conditions on the accumulation of compounds. The variable importance of projection value of orthogonal partial least square discriminant analysis and anti-inflammatory activity test showed that eupalinolide A, B, C, and K have high content and strong activity, which could provide a reference for the follow-up study of the quality markers of Eupatorium lindleyanum. Collectively, we developed a rapid and efficient method for the qualitative analysis and simultaneous quantification of Eupatorium lindleyanum, which was beneficial for the comprehensive utilization and development of resources.

Copolymerization is a commonly employed method for optimizing the properties of polymer materials. Incorporating ether segments into polyesters main chain to obtain polyether-polyester copolymers is an effective strategy to realize the integration of multiple properties of polyester and polyether, and to develop more high-performance, multi-purpose polymer materials. Herein, the synthesis of poly(ether-ester)s is accessible by employing the biphenyl-linked heterodinuclear salen Cr-Al complex in the presence of PPNCl for the copolymerization of epoxides and e-caprolactone (CL). Monitoring the copolymerization process reveals that catalyst 1 exhibited good performance for the copolymerization of epoxides and CL, affording copolymers with a gradient sequence structure. The dynamic thermomechanical analysis (DMA) study indicates the obtained poly(ether-ester)s possess enhanced flexibility compared with the block copolymers or blend of PPO and PCL homopolymers with the same ratio. This study provides a theoretical basis for the preparation of high-performance polymer materials.

Efficient and one-pot conversion of biomass-derived carbohydrate into highly value-added 5-hydroxymethylfurfural (HMF) is a crucial reaction step for the valorization of biomass resources toward bio-based chemicals and fuels. In this work, a series of Sn/SAPO-34 catalysts were prepared through impregnation and evaluated in glucose conversion to HMF. The physicochemical properties of Sn/SAPO-34 catalysts were systematically characterized by SEM, XRD, N2 physisorption, XPS, solid-state 119Sn, 29Si, and 31P NMR, XRF, UV–vis, NH3-TPD, and pyridine-FTIR techniques. It was demonstrated that controlling the Sn loading amount could facilely adjust the acid strength and acid amount of the SAPO-34 zeolite. The incorporation of Sn species could induce the formation of a tetrahedrally coordinated Sn4+ site and Sn-OH site to improve the amounts of Brønsted and Lewis acid sites of the catalyst. However, modification with sufficiently high Sn loading could decrease the acid strength and performance of the catalyst owing to its structure damage. The 5%Sn/SAPO-34 catalyst (i.e., Sn loading calculated based on the mass ratio of SnCl4·5H2O as a precursor to the parent SAPO-34) was found to exhibit the superior catalytic performance under mild conditions and could afford an HMF yield of 64.4% at 98.5% glucose conversion in a biphasic 35 wt % NaCl-H2O/tetrahydrofuran (THF) system at 150 °C within 1.5 h. Additionally, a catalytic reaction pathway was proposed, involving the adsorption of glucose molecules by the −Cl group on the catalyst via a hydrogen bond, followed by glucose isomerization to fructose over the Lewis acid Sn4+ and Al3+ sites and, finally, fructose dehydration to HMF catalyzed by the Brønsted acid Sn-OH and Si-OH-Al sites. The activity of the catalyst decreased due to the leaching of the active site Sn after several consecutive cycles. This work provides insights into the improvement in the Sn-containing zeolite catalyst for tandem conversion of glucose to HMF.

As a noninvasive therapy, high-intensity focused ultrasound (HIFU) shows great potential in inducing anticancer immune responses. However, the overall anticancer efficacy of HIFU is still limited due to the rapid attenuation of ultrasound waves and inadequacy of ultrasound waves to spread to the whole tumor. Here, we combined HIFU with the ultrasound contrast agent/chemotherapeutic drug co-delivery nanodroplets to achieve synergistic enhancement of anticancer efficacy. Different from the widely used thermal HIFU irradiation, by which excessive heating would result in inactivation of immune stimulatory molecules, we used short acoustic pulses to trigger HIFU (mechanical HIFU, mHIFU) to improve anticancer immune responses. The nanodroplets displayed a mHIFU/glutathione (GSH)-dual responsive drug release property, and their cellular uptake efficacy and toxicity against cancer cells increased upon mHIFU irradiation. The generated immunogenic debris successfully induced the exposure of damage-associated molecular patterns on the cell surface for dendritic cells (DCs) maturation. In vivo experiments with tumor-bearing mice showed that the co-delivery nanodroplets in combination with mHIFU could effectively inhibit tumor growth by inducing immunogenic cell death, activating DCs maturation, and enhancing the effector T-cell infiltration within tumors. This work reveals that combined treatment with nanodroplets and mHIFU is a promising approach to eradicate tumors.

Danqi tablet composed of the dried roots of Salvia miltiorrhiza and Panax notoginseng is a well-known Chinese patent medicine commonly used for the treatment of cardio-cerebrovascular diseases such as coronary heart disease and myocardial ischemia. Numerous chemical constituents belonging to S. miltiorrhiza and P. notoginseng were detectable in Danqi tablet. Here, we established and validated a rapid and sensitive ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry method for simultaneous quantification of 23 components in Danqi tablet and then successfully applied to assay 12 batches of samples from ten manufacturers. Our results demonstrated that the contents of 23 components in 12 batches of Danqi tablets varied significantly and their quality indeed existed different based on principal component analysis. According to the quantitative data and the loading plot of principal component analysis, five abundant compounds in Danqi tablet were selected as characteristic chemical markers possibly responsible for the quality assessment. Among them, salvianolic acid B and ginsenoside Rg1 were further chosen to be combined at 2:5 ratio to evaluate the anti-thrombotic activity on phenylhydrazine-induced zebrafish heart thrombosis model. Expectedly, this component combination increased the heart red blood cells intensity compared with the model group and the median effective concentration was 123.4 μg/mL, suggestive of its well anti-thrombotic effect. This study contributed to quantitative evaluation of Danqi tablet and indicated the combination of salvianolic acid B and ginsenoside Rg1 may be capable of reflecting the effect of Danqi tablet, thereby providing reference for further investigations on the improvement of quality control and clinical application of Danqi tablet. This article is protected by copyright. All rights reserved.

The increase of affected river reaches by reservoirs has drastically disturbed the original hydrological conditions, and subsequently influenced the nutrient biogeochemistry in the aquatic system, particularly in the cascade reservoir system. To understand the seasonal variation of nitrogen (N) behaviors in cascade reservoirs, hydrochemistry and nitrate dual isotopes (δ15N-NO3- and δ18O-NO3-) were conducted in a karst watershed (Wujiang River) in southwest China. The results showed that NO3--N accounted for almost 90% of the total dissolved nitrogen (TDN) concentration with high average concentration 3.8 ± 0.4 mg/L among four cascade reservoirs. Higher N concentration (4.0 ± 0.8 mg/L) and larger longitudinal variation were observed in summer than in other seasons. The relationship between the variation of NO3--N and dual isotopes in the profiles demonstrated that nitrification was dominated transformation, while assimilation contributed significantly in the epilimnion during spring and summer. The high dissolved oxygen concentration in the present cascade reservoirs system prevented the occurrence of N depletion processes in most of the reservoirs. Denitrification occurred in the oldest reservoir during winter with a rate ranging from 18 to 28%. The long-term record of surface water TDN concentration in reservoirs demonstrated an increase from 2.0 to 3.6 mg/L during the past two decades (~ 0.1 mg/L per year). The seasonal nitrate isotopic signature and continuously increased fertilizer application demonstrated that chemical fertilizer contribution significantly influenced NO3--N concentration in the karst cascade reservoirs. The research highlighted that the notable N increase in karst cascade reservoirs could influence the aquatic health in the region and further investigations were required.

A vinylogous aldol-type reaction of allylazaarenes and aldehydes is disclosed, which affords a series of chiral γ-hydroxyl-α,β-unsaturated azaarenes in moderate to excellent yields with high to excellent regio- and enantioselectivities. With ( R , R P )-TANIAPHOS and ( R , R )-QUINOXP* as the ligand, the carbon-carbon double bond in the products is generated in ( E )-form. With ( R )-DTBM-SEGPHOS as the ligand, ( Z )-form carbon-carbon double bond is formed in the major product. In this vinylogous reaction, aromatic, α,β-unsaturated, and aliphatic aldehydes are competent substrates. Moreover, a variety of azaarenes, such as pyrimidine, pyridine, pyrazine, quinoline, quinoxaline, quinazoline, and benzo[ d ]imidazole are well tolerated. At last, the chiral vinylogous product is demonstrated as a suitable Michael acceptor towards CuI-catalyzed nucleophilic addition with organomagnesium reagents.

Sulfur-containing polymers are polymers containing at least one sulfur atom in the repeat units of their main chains. The incorporation of sulfur atoms into the polymer main chains endows polymers with enhanced properties in many areas, including improved mechanical properties, optical properties, thermal properties, and adhesive abilities toward metal ions. Such enhanced properties make sulfur-containing polymers promising polymeric materials. In terms of environmental issues caused by waste plastic, the utilization of sulfur-containing polymers is also appealing from the aspect of degradability. Hence, degradable sulfur-containing polymers, including poly(thiocarbonate)s, poly(thioester)s, and poly(sulfite)s, are drawing more and more attention. However, the synthesis of these polymers involves problems like mixed structures and weak stereochemistry control of the resultant polymers due to the intrinsic properties of sulfur atoms, such as strong nucleophilicity and coordinative abilities. Thus, tackling the problems caused by sulfur chemistry is the main challenge relating to the precise synthesis of sulfur-containing polymers. Herein, this review describes recent progress made regarding the precise synthesis of sulfur-containing polymers from the perspectives of structure control, stereochemistry control, and topological structure modification.

The development of “metal-free” catalyst systems with high efficiency for the ring-opening polymerization (ROP) of epoxides, providing polyethers with controlled molecular weights and dispersity as well as the desired main-chain sequence, is crucially required. In this paper, we present a binary catalyst system, in which triphenylboroxin (TPBX) is employed as a catalyst in conjunction with bis-(triphenylphosphine)iminium chloride (PPNCl) as the initiator, for the ROP of epoxides to precisely synthesize polyethers. The binary TPBX/PPNCl system exhibits good activity under mild conditions, yielding polyethers with predictable molecular weights and low dispersity (Đ < 1.25). Of importance is that the ROP of epoxides mediated by the binary system shows a living polymerization character, allowing for the synthesis of multi-block polyethers. In addition, the synthesis of propylene oxide/ethylene oxide copolyethers with a random structure is achieved. Furthermore, on the basis of the kinetics study, a bimolecular TPBX cooperatively catalyzed mechanism is proposed and verified by density functional theory (DFT) calculations.

Polymeric materials possessing both high refractive indices and high Abbe numbers are much in demand for the development of advanced optical devices. However, the synthesis of such functional materials is a challenge because of the trade-off between these two properties. Herein, a synthetic strategy is presented for enhancing the optical properties of CO2 -based polycarbonates by modifying the polymer's topological structure. Terpolymers with thiocarbonate and carbonate units randomly distributed in the polymers' main chain were synthesized via the terpolymerization of cyclohexene oxide with a mixture of CO2 and COS in the presence of metal catalysts, most notably a dinuclear aluminum complex. DFT calculations were employed to explain why different structural sequence were obtained with distinct bimetallic catalysts. Varying the CO2 pressure made it possible to obtain terpolymers with tunable carbonate linkages in the polymer chain. More importantly, optical property studies revealed that terpolymers with comparable thiocarbonate and carbonate units exhibited a refractive index of 1.501 with an enhanced Abbe number as high as 48.6, much higher than the corresponding polycarbonates or polythiocarbonates. Additionally, all terpolymers containing varying thiocarbonate content displayed good thermal properties with Tg >109 °C and Td >260 °C, suggesting little loss in the thermal stability compared to the polycarbonate. Hence, modification of the topological structure of the polycarbonate is an efficient method of obtaining polymeric materials with enhanced optical properties without compromising thermal performance.

By using a mixed-ligand approach, a new Cu(II)-based coordination polymer (CP) with the chemical formula of {[Cu(tci)(bpy)(NO3)·DMF·0.5CH3CN}n (H3tci = tri(2-carboxyethyl) isocyanurate, bpy = 4,4-b...

Safflower has both medicinal and edible values but research on its nutrient composition is still lacking. This study was established for the quantitative determination of 28 nucleosides, nucleobases, and amino acids based on the ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry. Analysis of 30 batches of safflower from different producing areas indicated that the contents of l-proline, l-asparagine, l(+)-arginine, l-serine, l-histidine, uracil, guanosine, and uridine was high in safflower. Principle component analysis and cluster analysis found that samples from different regions could be distinguished well, and samples from the same area could be clustered into one class, different geographical environments may cause the differences of nucleosides, nucleobases, and amino acids in safflower. The analysis of principal component analysis, cluster analysis, and counter propagation artificial neural network show similar results. Then the content of nucleosides, nucleobases, and essential amino acids were compared, and found that the content in safflower from Gansu was higher than those from other regions, and there was a little difference between the samples from Xinjiang, Sichuan, and Yunnan. This research revealed the composition of nucleosides, nucleobases, and amino acids in safflower, and provided a theoretical basis for utilization of safflower.

Toughness improvement of thermosetting benzoxazine/epoxy blends is of great significance to expand their applications in the field of high-performance structural parts. Introduction of multiphase s...

Gold nanostars (AuNS) are promising carriers for targeted delivery of therapeutic oligonucleotides, but their potential in fabricating an on-demand drug release system in a facile and robust way remains to be explored. In this paper, we used a model aptamer (HApt), acting not only as a target ligand but also as a natural thermal-responsive material, to decorate AuNS. The prepared gold nanoconstruct, HApt@AuNS, displayed stoichiometric loading capacity of the anthracycline drug doxorubicin (Dox). The on-demand drug release was realized by illuminating nanoconstructs with near-infrared (NIR) light. Furthermore, a higher degree of Dox release from the nanoconstructs was achieved in an acidic environment, compared to neutral conditions. The

Topological polymers possess many advantages over linear polymers. However, when it comes to the poly(monothiocarbonate)s, no topological polymers have been reported. Described herein is a facile and efficient approach for synthesizing well-defined branched poly(monothiocarbonate)s in a "grafting through" manner by copolymerizing carbonyl sulfide (COS) with epichlorohydrin (ECH), where the side-chain forms in situ. The lengths of the side-chains are tunable based on reaction temperatures. More importantly, enhancement in thermal properties of the branched copolymer was observed, as the Tg value increased by 22 °C, compared to the linear analogues. When chiral ECH was utilized, semicrystalline branched poly(monothiocarbonate)s were accessible with a Tm value of 112 °C, which is 40 °C higher than that of the corresponding linear poly(monothiocarbonate)s. The strategy presented herein for synthesizing branched polymers provides efficient and concise access to topological polymers.

The copolymerization of epoxides and cyclic thioanhydrides provides a promising method to produce polythioesters and represents an alternative route to the step-growth condensation of dithiols and ...

Polyesters, as a class of high-performance and versatile polymer materials, often suffer from some drawbacks, such as hydrophobicity and brittleness due to their single structure nature. Thus, modifications have attracted much attention for enhancing their desirable properties, of which one efficient way is incorporating the aliphatic polyether segment into the main chain of the polyester. However, this approach is of much challenge because the obtained polyesters are problematic in either low alternating degree or low molecular weight. Herein, we describe an efficient strategy to incorporate polyether fragment into polyester by developing a novel Co-Al based heterodinuclear complex for mediating the copolymerization of propylene oxide (PO) with e-caprolactone (CL). The tracking experiments reveal that PO and CL convert into the polymer chain throughout the polymerization process. Especially, the linear increase in the molecular weight with conversion of CL indicates the controllable nature of the copolymerization. The competition polymerization, offering the monomer reactivity ratios of rCL = 0.96 and rPO = 1.04, suggests that the tendency of self-propagation or incorporation of monomers is nearly identical. Interestingly, the obtained polymers with different ether contents exhibit tunable thermal properties with enhanced decomposition temperature for the polymer with higher ether content. The newly developed heterodinuclear complex for new polymerization provides an idea to synthesize new functional polymeric materials.

Elimination of soot particles from diesel exhaust remains one of the most pressing environmental issues. During the NOx-assisted soot catalytic oxidation process, it is proposed that the enhanced adsorption of NOx species (including NO and NO2) on the catalyst plays an important role in soot combustion. In this work, the 3DOM mullite catalysts with distinct NOx adsorption properties were designed, and the effect of NOx adsorption intensity on soot combustion behavior was investigated. It is proven that the soot combustion activity of 3DOM SmMn2O5 (SMO) catalyst was greatly improved when the adsorption of NOx on the catalyst was strengthened by the modification of K2Mn4O8 (KMO). Among all the as-prepared catalysts, the 5% KMO-SMO catalyst stands out with the best performance with the T10, T50, T90 and SCO2 of 299 °C, 336 °C, 383 °C and 99%, which represents one of the best catalysts for soot combustion application. Besides, our reaction mechanism analysis illustrates the importance of balancing the NOx adsorption and NO oxidation on modified SMO catalyst for NOx-assisted soot combustion reaction.

1,2-Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)-catalyzed asymmetric hydrophosphination of α,β-unsaturated phosphine sulfides was developed with the assistance of "soft-soft" interaction between copper(I)-catalyst and the phosphine sulfide moiety, which afforded 1,2-bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo- and enantioselectivities. Interestingly, the nucleophilic copper(I)-diphenylphosphide species was characterized by 31 P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2-bisphosphines, which were employed as ligands in Rh-catalyzed asymmetric hydrogenation of α-amino-α,β-unsaturated ester. The α-amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.

A green and convenient solid-state method assisted by mechanical energy is employed for the synthesis of boron (B) and nitrogen (N) co-doped porous carbons (B,N-Cs). Glutamic acid (Glu) and boric acid (H3 BO3 ) are used as the N-containing carbon precursor and boron source, respectively. This method is easy to perform and proved to be efficient towards co-doping B and N into the carbon matrix with high contents of B (7 atom %) and N (10 atom %). By adjusting the molar ratio of H3 BO3 to Glu, the surface chemical states of B and N could be readily modulated. When increasing H3 BO3 dosage, the pore size of B,N-Cs could be tuned ranging from micropores to mesopores with a Brunauer-Emmett-Teller (BET) surface area up to 940 m2 g-1 . Finally, the B,N-Cs were applied as metal-free catalysts for the cycloaddition of CO2 to epoxides, which outperform the N-doped carbon catalyst (NC-900) and the physically mixed catalyst of NC-900/B4 C. The enhanced activity is attributed to the cooperative effect between B and N sites. X-ray photoelectron spectroscopy (XPS) analysis reveals that BN3 in the B,N-Cs serves as a critical active site for the cooperative catalysis.

The mulberry leaf is a classic herb commonly used in traditional Chinese medicine. It has also been used as animal feed for livestock and its fruits have been made into a variety of food products. Traditionally, mulberry (Morus alba L.) leaf harvesting after frost is thought to have better medicinal properties, but the underlying mechanism remains largely unsolved. To elucidate the biological basis of mulberry leaves after frost, we first explored the content changes of various compounds in mulberry leaves at different harvest times. Significant enrichment of flavonoids was observed with a total of 224 differential metabolites after frost. Subsequently, we analyzed the transcriptomic data of mulberry leaves collected at different harvest times and successfully annotated 22,939 unigenes containing 1,695 new genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed 26, 20, and 59 unigenes related to flavonoids synthesis in three different groups harvested at different times. We found that the expression levels of flavonoid biosynthesis-related unigenes also increased when harvested at a delayed time, which was consistent with the flavonoid accumulation discovered by the metabolomic analysis. The results indicated that low temperature may be a key trigger in flavonoid biosynthesis of mulberry leaves by increasing the expression of flavonoid biosynthesis-related genes. This study also provided a theoretical basis for the optimal harvest time of mulberry leaves.

Nitrogen and phosphorus are key elements in controlling eutrophication in the aquatic system. Water and sediment samples were collected from Hongfeng Lake, a seasonally stratified reservoir in southwest China, in winter and summer. Diffusion fluxes of NH4+, NO3−, and labile P in summer using diffusive gradients in thin films technology were 3.4, −37.2, and 0.9 mg m−2 day−1, respectively, based on Fick’s first law. The diffusion flux of labile P was 2.05 mg m−2 day−1 in winter. The contributions fraction of the labile P diffusion flux from sediment to the overlying water were higher in winter than those in summer, because of the relatively lower external input, concentrations and higher diffusion fluxes in winter. After the external input decreased, all of the three diffusion fluxes were lower than the previous record. To understand the influence effect of hydrodynamics, environmental fluid dynamics code modeling was used to simulate the flow and temperature field in winter and summer. Modeling results showed that velocity in summer was higher than that in winter due to concentrated rainfall within the catchment. Moreover, the velocity and temperature in the euphotic zone were higher than that of the hypolimnion in summer. Less variation of velocity and temperature in vertical profile in winter than that in summer was observed, which may be attributable to the high specific heat capacity and the low heat conductivity of water. There was no significant correlation among velocity, hydrochemistry, nitrogen, and phosphorus concentrations. Hydrodynamics, solar radiation, and water depth affect the position of the thermocline, which was consequently to water temperature, hydrochemistry, dissolved nitrogen, and phosphorus concentration. Correlation analysis suggested that the higher bottom velocity and total bed shear may accelerate labile P, NH4+, and NO3− diffusion fluxes. These results provide evidence and suggestions for preventing and controlling reservoir eutrophication and water safety management.

The efficient conversion of hemicellulose and cellulose into reducing sugars remains as one major challenge for biorefinery of lignocellulosic biomass. In this work, saccharification of corncob in the aqueous phase was effectively realized via pretreatment by magnetic carbon-based solid acid (MMCSA) catalyst, combined with the subsequent in situ enzymatic hydrolysis (occurring in the same pretreatment system after separation of MMCSA). Through the combined two-step hydrolysis of corncob, the total sugar (xylose and glucose) yield of 90.03% was obtained, including a xylose yield of 86.99% and an enzymatic digestibility of pretreatment residue of 91.24% (cellulase loading of 20 FPU/g, 24 h). Compared with the traditional enzymatic hydrolysis of pretreated residue, the presented in situ enzymatic hydrolysis system can reach a comparable enzymatic digestibility in one-third reacting time with a half cellulase loading and save about 31% water consumption, which provides a more sustainable and low-cost method for the saccharification of lignocellulose.

Introducing multiphase structures into benzoxazine (BOZ)/epoxy resins (ER) blends via reaction-induced phase separation has proved to be promising strategy for improving their toughness. However, due to the limited contrast between two phases, little information is known about the phase morphological evolutions, a fundamental but vital issue to rational design and preparation of blends with different phase morphologies in a controllable manner. Here we addressed this problem by amplifying the difference of polymerization activity (PA) between BOZ and ER by synthesizing a low reactive phenol-3,3-diethyl-4,4′-diaminodiphenyl methane based benzoxazine (MOEA-BOZ) monomer. Results indicated that the PA of ER was higher than that of BOZ. The use of less reactive MOEA-BOZs significantly enlarged their PA difference with ER, and thus increased the extent of phase separation and improved the phase contrast. Phase morphologies varied with the content of ER. As for the phase morphological evolution, a rapid phase separation could occur in the initial homogeneous blends with the polymerization of ER, and the phase morphology gradually evolved with the increase in ER conversion until the ER was used up. The polymerization of ER is not only the driving-force for the phase separation, but also the main factor influencing the phase morphologies.

Red and yellow pigments are the major ingredients of safflower, often used to color food and cosmetics. Carthamin, the main component of red pigment, and hydroxysafflor yellow A, anhydrosafflower yellow B were representative components of yellow pigment. Plant metabolomics and semi-quantitative analysis were used to analyze the changes of pigment composition during blooming period, especially these characteristic components. Carthamin, hydroxysafflor yellow A, anhydrosafflower yellow B and other components were screened out as differential metabolites based on plant metabolomics. Then semi-quantitative analysis was used to quantify these three representative components of pigments. Experimental results showed that: content of pigments has dynamic changes along with flowering, in the early blooming period, yellow pigment accumulated much and red pigment was low in content. In the middle period, the accumulation rate of the yellow pigment slowed down and content was stabilized. In the next step, the content of yellow pigment gradually decreased, and the content of red pigments gradually increased. Later, the level of yellow pigment decreased significantly, and accumulation rate of red pigment increased significantly. Lastly, the appearance color of safflower was red, with yellow parts barely visible, and accumulation of red pigment was highest, yellow pigment was lowest in content. This article is protected by copyright. All rights reserved.

Unintended pregnancy is a situation that every woman may encounter, and medical abortion is the first choice for women, but abortion often brings many sequelae.Angelica sinensisRadix (Danggui) andLeonuriHerba (Yimucao) are widely used in the treatment of gynecological diseases, which can regulate menstrual disorders, amenorrhea, dysmenorrhea, and promote blood circulation and remove blood stasis, but the mechanism for the treatment of abortion is not clear. We determined the ability of Danggui and Yimucao herb pair (DY) to regulate the Th1/Th2 paradigm by detecting the level of progesterone in the serum and the expression of T-bet and GATA-3 in the spleen and uterus. Then, we detected the level of metabolites in the serum and enriched multiple metabolic pathways. The arachidonic acid pathway can directly regulate the differentiation of Th1/Th2 cells. This may be one of the potential mechanisms of DY in the treatment of abortion.

Dahuang-Gancao decoction (DGD) is a classical formula, which is commonly used for reliving constipation in Chinese clinic. The aim of this study was to investigate the pharmacodynamic, pharmacokinetic and tissue distribution alternations of DGD in normal and constipation mice. DGD exhibited stronger purgative effect in constipation mice by the increased fecal excretion and reduced first defection time compared with normal mice. The Cmax, AUC0-t and MRT0-t of rhein, aloe-emodin, rhein-8-O-β-D-glucoside, sennoside A, and glycyrrhizic acid as main bio-active components in DGD were markedly increased in constipation mice. The tissue distribution of the analytes in constipation mice were higher than those in normal mice with rhein > rhein-8-O-β-D-glucoside > aloe-emodin > glycyrrhizic acid > emodin in liver, and glycyrrhizic acid > rhein-8-O-β-D-glucoside > liquitin > sennoside A > rhein > aloe-emodin > emodin in colon. The kidney concentrations of the analytes showed a descending order of rhein > rhein-8-O-β-D-glucoside > sennoside A > glycyrrhizic acid > aloe-emodin > emodin, most of them were higher while rhein was lower in constipation mice than normal mice. The higher exposure of the anthraquinones in plasma, liver and colon may result in the stronger purgative effect in the constipation mice than normal mice. Rhein is mainly excreted through the kidney, the decreased level of rhein in constipation mice may explain the alleviated side effects. Accumulation of glycyrrhizic acid in colon may related with the moderate property of licorice. These results provided the experimental basis for understanding the therapeutic effects and metabolite profile of DGD.

Although compatibility is highly advocated in traditional Chinese medicine (TCM), inappropriate combination of some herbs may reduce the therapeutic action and even produce toxic effects. Kansui and licorice, one of TCM “Eighteen Incompatible Medicaments”, are the most representative cases of improper herbal combination, which may still be applied simultaneously under given conditions. However, the potential mechanism of their compatibility and incompatibility is unclear. In the present study, two different ratios of kansui and licorice, representing their compatibility and incompatibility respectively, were designed to elucidate their interaction by comparative plasma/tissue metabolomics and a heatmap with relative fold change. As a result, glycocholic acid, prostaglandin F2a, dihydroceramide and sphinganine were screened out as the principal alternative biomarkers of compatibility group; sphinganine, dihydroceramide, arachidonic acid, leukotriene B4, acetoacetic acid and linoleic acid were those of incompatibility group. Based on the values of biomarkers in each tissue, the liver was identified as the compatible target organ, while the heart, liver, and kidney were the incompatible target organs. Furthermore, important pathways for compatibility and incompatibility were also constructed. These results help us to better understand and utilize the two herbs, and the study was the first to reveal some innate characters of herbs related to TCM “Eighteen Incompatible Medicaments”., Graphical abstract Image 1, Highlights • Comparative metabolomics was employed to dissect the compatibility and incompatibility mechanism of kansui and licorice. • An interactive heatmap with relative fold change was created to explore complex metabolomics data of herb-herb interaction. • The study first revealed some innate important characters of herbs related TCM “Eighteen Incompatible Medicaments”.

The enzymatic esterification of oleic acid and 1-butanol to butyl oleate was performed in an aqueous-organic system in capillary microreactors with various inner diameters operated under slug flow. The free Rhizomucor miehei lipase in the aqueous phase was used as catalyst and n-heptane as the organic solvent. A close to 100% yield of butyl oleate could be achieved in the microreactor made of polytetrafluoroethylene within 30 min residence time at 30 °C. The reaction rate is well described by the existing kinetic model based on a Ping Pong Bi Bi mechanism with competitive inhibition of 1-butanol. This model was extended to describe the effect of the interfacial area and aqueous to organic flow ratio in microreactors. By performing the reaction at low aqueous to organic flow ratios in hydrophilic microreactors (e.g., made of stainless steel), the enzyme turnover number could be enhanced significantly making it promising for process intensification.

In order to improve the stability of silicon-based heavy metals adsorbents and reduce ions release (Zn, Mg, etc) in the ion exchange process, a novel adsorbent with excellent heavy metal adsorption was synthesized by loading sodium isobutyl xanthate (SIBX) onto the surface of silicon-zinc mesoporous (SZM) material. For comparison, two silicon-zinc materials using silicate (Na2SiO3, inorganic silicon) and tetraethyl orthosilicate (C8H20O4Si, organic silicon) were synthesized separately. Among them, inorganic silicon-zinc mesoporous (SZM-1) material was used to verify its ions exchange properties, organic silicon-zinc mesoporous (SZM-2) material acts as matrix and modified with SIBX. The copper sulfate solution was employed to evaluate the adsorption ability of as-prepared adsorbents. Above materials were characterized by a set of complementary techniques: SEM-EDS, XRD, TEM, BET, FT-IR, and XPS. The analyses prove that the SIBX can be attached to the surface of the SZM-2, the presence of SIBX can simultaneously immobilize Zinc atoms and adsorb Copper ions.

Summary Two catalytic asymmetric vinylogous aldol-type reactions of aldehydes with allyl phosphonate and allyl sulfone have been uncovered in good to high yields for the first time. The bulky ligand—(R)-DTBM-SEGPHOS—was found to be the key to perfectly control both regio- and enantioselectivities. Transformations of the vinylogous products (including Horner-Wadsworth-Emmons and Julia olefinations) were successfully realized by virtue of the phosphonate and sulfone moieties. Moreover, the present methodology was successfully applied in the asymmetric synthesis of natural products., Graphical Abstract, Highlights • Asymmetric vinylogous aldol • Excellent regioselectivity • HWE and Julia olefinations, Chemistry; Organic Synthesis; Stereochemistry

We report a new semiaromatic poly(thioester) obtained through the copolymerization of phthalic thioanhydride and propylene oxide. The reaction was catalyzed by a chromium-based complex in conjuncti...

The retention of polyvinyl chloride (PVC) microplastics in sewage sludge during wastewater treatment raises concerns. However, the effects of PVC microplastics on methane production from anaerobic digestion of waste activated sludge (WAS) have never been documented. In this work, the effects of PVC microplastics (1 mm, 10-60 particles/g TS) on anaerobic methane production from WAS were investigated. The presence of 10 particles/g TS of PVC microplastics significantly ( P = 0.041) increased methane production by 5.9 ± 0.1%, but higher levels of PVC microplastics (i.e., 20, 40, and 60 particles/g TS) inhibited methane production to 90.6 ± 0.3%, 80.5 ± 0.1%, and 75.8 ± 0.2% of the control, respectively. Model-based analysis indicated that PVC microplastics at >20 particles/g TS decreased both methane potential (B0) and hydrolysis coefficient (k) of WAS. The mechanistic studies showed that bisphenol A (BPA) leaching from PVC microplastics was the primary reason for the decreased methane production, causing significant ( P = 0.037, 0.01, 0.004) inhibitory effects on the hydrolysis-acidification process. The long-term effects of PVC microplastics revealed that the microbial community was shifted in the direction against hydrolysis-acidification and methanation. In conclusion, PVC microplastic caused negative effects on WAS anaerobic digestion through leaching the toxic BPA.

Boron trioxide (B2O3), a common and easily available boron oxide, was first reported as an effective metal-free heterogeneous catalyst for the chemical fixation of CO2 with epoxides to produce cyclic organic carbonates (COCs). The ball-milling treatment of B2O3 significantly enhanced the catalytic activity by increasing the adsorption capacity to propylene oxide substrate. In situ DRIFTS characterization indicated there was a ring opening process of epoxides on the surface of B2O3, which was induced by the boron sites from B2O3. The recovery test of B2O3 showed that it could be easily recycled and reused for 5 runs without a loss of activity. This kind of Lewis acid catalytic property of B2O3 marks a rare case of a metal-free heterogeneous catalyst mimicking the metal-based catalysts for the COCs production.

Coupled nitrogen and oxygen isotopes of nitrate have proven useful in identifying nitrate sources and transformation in rivers. However, isotopic fractionation and low-resolution monitoring limit the accurate estimation of nitrate dynamics. In the present study, the spatio-temporal variations of nitrate isotopes (N-15 and O-18) and hydrochemical compositions (NO3- and Cl-) of river water were examined to understand nitrate sources in the Xijiang River, China. High-frequency sampling campaigns and isotopic analysis were performed at the mouth of the Xijiang River to capture temporal nitrate variabilities. The overall values of delta N-15-NO3- and delta O-18-NO3- ranged from +4.4% to +14.1% and from -0.3% to +6.8%, respectively. The results of nitrate isotopes indicated that NO3- mainly originated from soil organic nitrogen (SON), chemical fertilizer (CF), and manure and sewage wastes (MS whereas approximately 58% of nitrate was derived from anthropogenic inputs (M&S and CF) in the dry season. The nitrate flux was 2.08 x 10(5) tons N yr(-1) during one hydrologic year between 2013 and 2014, with 86% occurring in the wet season. Long-term fluctuations in nitrate flux indicated that nitrate export increased significantly over the past 35 years, and was significantly correlated with nitrate concentrations. The seasonal pattern of nitrate dynamics indicated the mixing of nitrified NO3- and denitrified NO3- between surface flow and groundwater flow under different hydrological conditions. Overall, the present study quantitatively evaluates the spatio-temporal variations in nitrate sources in a subtropical watershed, and the high-frequency monitoring gives a better estimate of nitrate exports and proportional contributions of nitrate sources.

Highly dispersed platinum (Pt) nanoparticles are deposited on CeO2 nanorods via atomic layer deposition (ALD) to improve the catalytic activity towards the NO–CO reaction. For comparison, CeO2 nanosphere and CeO2 nanorod loaded Pt nanoparticle catalysts fabricated by ALD and incipient wetness impregnation (IWI) are studied. The size distribution of Pt nanoparticles of Pt/CeO2 nanosphere (Pt/CeO2-NS) and Pt/CeO2 nanorod (Pt/CeO2-NR) catalysts prepared by ALD is quite narrow and uniform (3.05 ± 0.42 nm for Pt/CeO2-NSs, and 3.05 ± 0.38 nm for Pt/CeO2-NRs) compared to that of the PtIWI/CeO2-NS catalyst prepared by incipient wetness impregnation. The combination of XPS, H2-TPR, XAFS and in situ DRIFTS characterization techniques confirms that the strong interaction between Pt nanoparticles and CeO2 nanorods leads to the decrease of the CO poisoning effect on Pt and activation of oxygen around the interfaces. As a result, the full conversion of NO takes place at a relatively low temperature of ∼200 °C, revealing that the activity of the ALD prepared Pt/CeO2-NR catalyst is greatly enhanced.

This paper presents an experimental study on the catalytic methane combustion (CMC) in plate-type microreactors with wall-coated Pt/γ-Al2O3 catalyst. Firstly, the influence of different operational conditions and coating properties on the CMC in the straight parallel-channel microreactor has been investigated. A specific catalyst loading of 57.6 g m−2 was found to yield the highest methane conversion over 3.5 wt% Pt/γ-Al2O3. A higher or lower loading tended to decrease the methane conversion due to either the limited internal diffusion through the thicker coating layer or insufficient active sites in the thinner coating layer. Then, the above microreactor was compared with other five different geometries, including cavity, double serpentine microchannels, obstacled microchannels, meshed circuit and vascular network. The double serpentine microchannel geometry presented the highest methane conversion (especially at a relatively low mixture flow rate) due to the appropriate control over the residence time and catalyst coating surface area.

Conventional hydrodesulfurization technology was limited to treat aromatic heterocyclic sulfur compounds in ultralow-sulfur diesel. Extractive desulfurization (EDS) using ionic liquid (IL) exhibited good performance to address these issues, except for its long extraction time (15–40 min). To address this, microreactor was adopted to intensify the IL-based EDS, where dibenzothiophene was extracted from model diesel (MD) as the continuous phase to 1-butyl-3-methylimidazolium tetrafluoroborate as the dispersed phase under segmented flow (which appeared preferably at capillary numbers lower than 0.01). The effects of temperature, residence time and flow rate ratio on the desulfurization efficiency were investigated. The extraction equilibration time could be shortened from more than 15 min in conventional batch extractors to 120 s in microreactors. The extraction process was modeled according to the two-film model applied within a unit cell of the segmented flow, where the mass transfer resistance was considered primarily on the film side of the IL droplet. The mechanism for the improved EDS performance at higher temperatures or larger IL to MD flow ratios was investigated and validated, which was related to the significant increase in the diffusion coefficient or the specific interfacial area. These findings may shed important insights into the precise manipulation of IL-based EDS for a better process design and reactor optimization.

Irinotecan (CPT-11)-induced gastrointestinal toxicity strongly limits its anticancer efficacy. Glycyrrhiza uralensis Fisch., especially flavonoids, has strong anti-inflammatory and immunomodulatory activities. Herein, we investigate the protective effect of the total flavonoids of G. uralensis (TFGU) on CPT-11–induced colitis mice from the perspective of gut microbiota and fecal metabolism. The body weight and colon length of mice were measured. Our results showed that oral administration of TFGU significantly attenuated the loss of body weight and the shortening of colon length induced by CPT-11. The elevated disease activity index and histological score of colon as well as the up-regulated mRNA and protein levels of TNF-α, IL-1β, and IL-6 in the colonic tissue of CPT-11–treated mice were significantly decreased by TFGU. Meanwhile, TFGU restored the perturbed gut microbial structure and function in CPT-11–treated mice to near normal level. TFGU also effectively reversed the CPT-11–induced fecal metabolic disorders in mice, mainly call backing the hypoxanthine and uric acid in purine metabolism. Spearman’s correlation analysis further revealed that Lactobacillus abundance negatively correlated with fecal uric acid concentration, suggesting the pivotal role of gut microbiota in CPT-11–induced colitis. Since uric acid is a ligand of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, TFGU was further validated to inhibit the activation of NLRP3 inflammasome by CPT-11. Our findings suggest TFGU can correct the overall gut microbial dysbiosis and fecal metabolic disorders in the CPT-11–induced colitis mice, underscoring the potential of using dietary G. uralensis as a chemotherapeutic adjuvant.

The efficient conversion of hemicellulose and cellulose in lignocellulosic biomass to reducing sugars remains as one major challenge for the development of biorefinery. In this work, corncob saccharification in the aqueous phase was realized efficiently via pretreatment by magnetic carbon-based solid acid (MMCSA) catalyst, combined with the subsequent in situ enzymatic hydrolysis (occurring in the same pretreatment system after MMCSA separation). Under the optimized pretreatment conditions (the ratio of corncob, catalyst and water is 1:1:20 (g:g:mL), 160°C for 20 min) and in situ enzymatic hydrolysis (cellulase loading of 20 FPU / g, 24 h), an xylose yield of 88.77% and an enzymatic digestibility of 91.24% were obtained, respectively. Compared with the traditional enzymatic process, the present in situ enzymatic system has advantages of reduced enzyme loading, water consumption, and improved saccharification efficiency. Thus, this study provides a more sustainable and effective method for the saccharification of hemicellulose and cellulose in the corncob to produce reducing sugars.

Therapeutic oligonucleotides (TOs) represent one of the most promising drug candidates in the targeted cancer treatment due to their high specificity and capability of modulating cellular pathways that are not readily druggable. However, efficiently delivering of TOs to cancer cellular targets is still the biggest challenge in promoting their clinical translations. Emerging as a significant drug delivery vector, nanoparticles (NPs) can not only protect TOs from nuclease degradation and enhance their tumor accumulation, but also can improve the cell uptake efficiency of TOs as well as the following endosomal escape to increase the therapeutic index. Furthermore, targeted and on-demand drug release of TOs can also be approached to minimize the risk of toxicity towards normal tissues using stimuli-responsive NPs. In the past decades, remarkable progresses have been made on the TOs delivery based on various NPs with specific purposes. In this review, we will first give a brief introduction on the basis of TOs as well as the action mechanisms of several typical TOs, and then describe the obstacles that prevent the clinical translation of TOs, followed by a comprehensive overview of the recent progresses on TOs delivery based on several various types of nanocarriers containing lipid-based nanoparticles, polymeric nanoparticles, gold nanoparticles, porous nanoparticles, DNA/RNA nanoassembly, extracellular vesicles, and imaging-guided drug delivery nanoparticles., Graphical abstract Image 1, Highlights • Therapeutic TOs are most promising drug candidates for cancer therapy. • Successful delivery of TOs is the biggest challenge for clinic translation. • Nanocarriers have revolutionized and greatly promote the delivery of TOs in vivo. • LNPs and extracellular vesicles are most commonly developed for TOs delivery. • New generation of delivery systems for TOs still need to be further developed.

The increase of affected river reaches by reservoirs has drastically disturbed the original hydrological conditions, and subsequently influenced the nutrient biogeochemistry in the aquatic system, particularly in the cascade reservoir system. To understand the seasonal variation of nitrogen (N) behaviors in cascade reservoirs, hydrochemistry and nitrate dual isotopes (δ15N-NO3− andδ18O-NO3−) were conducted in a karst watershed (Wujiang River) in southwest China. The results showed that NO3−–N accounted for almost 90% of the total dissolved nitrogen (TDN) concentration with high average concentration 3.8 ± 0.4 mg/L among four cascade reservoirs. Higher N concentration (4.0 ± 0.8 mg/L) and larger longitudinal variation were observed in summer than in other seasons. The relationship between the variation of NO3−–N and dual isotopes in the profiles demonstrated that nitrification was dominated transformation, while assimilation contributed significantly in the epilimnion during spring and summer. The high dissolved oxygen concentration in the present cascade reservoirs system prevented the occurrence of N depletion processes in most of the reservoirs. Denitrification occurred in the oldest reservoir during winter with a rate ranging from 18 % to 28 %. The long-term record of surface water TDN concentration in reservoirs demonstrated an increase from 2.0 to 3.6 mg/L during the past two decades (~ 0.1 mg/L per year). The seasonal nitrate isotopic signature and continuously increased fertilizer application demonstrated that chemical fertilizer contribution significantly influenced NO3−–N concentration in the karst cascade reservoirs. The research highlighted that the notable N increase in karst cascade reservoirs could influence the aquatic health in the region and further investigations were required.

Leonurus japonicus Houtt., a traditional Chinese herbal medicine, is often used as a gynecological medicine with the effect of promoting blood circulation, regulating menstruation, clearing heat, and detoxificating. As the most important alkaloid in L. japonicus, leonurine has a wide range of biological activities, such as antioxidation, anti‐inflammation, and anti‐apoptosis. Cardiovascular system and central nervous system diseases are arrogant killers that threaten human lives and health around the world, but many drugs for treating them have certain side effects. This paper reviews the potential therapeutic effects of leonurine on cardiovascular system and central nervous system diseases, summarizes the previous research progress, and focuses on its therapeutic effect in various diseases. Although leonurine plays a prominent role in the treatment of cardiovascular system and central nervous system diseases, there are still some shortages, such as low bioavailability, weak transmembrane ability, and poor fat solubility. Therefore, the structure modification of leonurine may solve these problems and provide reference value for the development of new drugs. At present, leonurine is in clinical trial, and it is hoped that our summary will help to provide guidance for its future research on the basic science and clinical application., This article reviews the pharmacological effects of a hot potential drug leonurine on cardiovascular and brain diseases. Its structure modification may be an effective way to reduce side effects, strengthen efficacy, and improve bioavailability. We believe that in the near future, leonurine is very likely to become one of the new drugs following the results of artemisinin, which will benefit all human beings.

Fluorescence (excitation-emission matrices, EEMs) spectroscopy coupled with PARAFAC (parallel factor) modelling and UV-Vis (ultraviolet visible) spectra were used to ascertain the sources, distribution and biogeochemical transformation of dissolved organic matter (DOM) in the Duliujian River catchment. Dissolved organic carbon (DOC), chromophoric dissolved organic matter (a335) (CDOM), and hydrophobic components (a260) were higher in summer than in other seasons with 53.3 m−1, while aromaticity (SUVA254) was higher in spring. Four fluorescent components, namely terrestrial humic acid (HA)-like (A/C), terrestrial fulvic acid (FA)-like (A/M), autochthonous fulvic acid (FA)-like (A/M), and protein-like substances (Tuv/T), were identified using EEM-PARAFAC modelling in this river catchment. The results demonstrated that terrestrial HA-like substances enhance its contents in summer ARE compared with BRE, whilst terrestrial FA-like substances were newly input in summer ARE, which was entirely absent upstream and downstream, suggesting that rain events could significantly input the terrestrial soil-derived DOM in the ambient downward catchments. Autochthonous FA-like substances in summer BRE could derive from phytoplankton in the downstream waters. The results also showed that DOM from wetland exhibited lower fluorescent intensity of humic-like peak A/C and fulvic-like peak A/M, molecular weight (SR) and humification index (HIX) during the low-flow season. Built-up land, cropland, and unused land displayed higher a335 (CDOM). A higher proportion of forest and industrial land in the SCs showed higher SUVA254 values. Humic-like moiety, molecular weight and aromaticity were more responsive to land use during stormflow in summer. Rainfall could increase the export of soil DOM from cropland and unused land, which influences the spatial variation of HIX. The results in this study highlighted that terrestrial DOM has a significant influence on the biogeochemical alterations of DOM compositions and thus water quality in the downward watershed catchments, which might significantly vary according to the land-use types and their alterations by human activities.

The production of fluorescent dissolved organic matter (FDOM) by phytoplankton and its subsequent degradation, both of which occur constantly under diurnal-day time sunlight and by night time dark-microbial respiration processes in the upper layer of surface waters, influence markedly several biogeochemical processes and functions in aquatic environments and can be feasibly related to global warming (GW). In this work sunlight-mediated high-temperature was shown to accelerate the production of FDOM, but also its complete disappearance over a 24-h diurnal period in July at the highest air and water temperatures (respectively, 41.1 and 33.5 °C), differently from lower temperature months. Extracellular polymeric substances (EPS), an early-state DOM, were produced by phytoplankton in July in the early morning (6:00–9:00), then they were degraded into four FDOM components over midday (10:00–15:00), which was followed by simultaneous production and almost complete degradation of FDOM with reformation of EPS during the night (2:00–6:00). Such transformations occurred simultaneously with the fluctuating production of nutrients, dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and the two isotopes (δ15N and δ18O) of NO3−. It was estimated that complete degradation of FDOM in July was associated with mineralization of approximately 15% of the initial DOC, which showed a nighttime minimum (00:00) in comparison to a maximum at 13:00. FDOM identified by excitation-emission matrix spectroscopy combined with parallel factor analysis consisted of EPS, autochthonous humic-like substances (AHLS) of C- and M-types, a combined form of C- and M-types of AHLS, protein-like substances (PLS), newly-released PLS, tryptophan-like substances, tyrosine-like substances (TYLS), a combined form of TYLS and phenylalanine-like substances (PALS), and their degradation products. Finally, stepwise degradation and production processes are synthesized in a pathway for FDOM components production and their subsequent transformation under different diurnal temperature conditions, which provided a broader paradigm for future impacts on GW-mediated DOM dynamics in lake water.

Remediation of nitrate pollution of Earth’s rivers and aquifers is hampered by cumulative biogeochemical processes and nitrogen sources. Isotopes (δ15N, δ18O) help unravel spatiotemporal nitrogen(N)-cycling of aquatic nitrate (NO3−). We synthesized nitrate isotope data (n = ~5200) for global rivers and shallow aquifers for common patterns and processes. Rivers had lower median NO3− (0.3 ± 0.2 mg L−1, n = 2902) compared to aquifers (5.5 ± 5.1 mg L−1, n = 2291) and slightly lower δ15N values (+7.1 ± 3.8‰, n = 2902 vs +7.7 ± 4.5‰, n = 2291), but were indistinguishable in δ18O (+2.3 ± 6.2‰, n = 2790 vs +2.3 ± 5.4‰, n = 2235). The isotope composition of NO3− was correlated with water temperature revealing enhanced N-cascading in warmer climates. Seasonal analyses revealed higher δ15N and δ18O values in wintertime, suggesting waste-related N-source signals are better preserved in the cold seasons. Isotopic assays of nitrate biogeochemical transformations are key to understanding nitrate pollution and to inform beneficial agricultural and land management strategies.

Today renewable energies such as biodiesel have considerable role in the bio-based economy. Long production time and low efficiency are a number of problems in biodiesel production that is essential to be considered when designing and operating the biodiesel production systems. In this study, using safflower oil in a hydrodynamic cavity reactor, biodiesel fuel was produced in the possible shortest time and maximum efficiency. The effect of reaction time (30, 60 and 90 s), concentration of potassium hydroxide catalyst (0.75%, 1% and 1.25%), alcohol to oil ratio (6, 8 and 10) and rotor-stator distance (1 cm, 2 cm and 3 cm) on the reaction yield were analyzed. The results were analyzed by response surface methodology. Among the independent variables, reaction time was the most important factor on the reaction yield, which had a positive impact on the quality of methyl ester. The optimum values obtained were: 63.88 s reaction time, 0.94% catalyst concentration, 1: 8.36 alcohol to oil molar ratio, 1.53 cm rotor-stator distance, and 89.11% yield. Several properties and compounds of biodiesel obtained were measured and compared with ASTM D6751 (American Society for Testing and Materials) and EN 14214 standard (European Standards). The results showed that most of the features conform to the afore-mentioned standard. Therefore, transesterification of safflower oil with a hydrodynamic cavitation reactor can function as a good alternative to the diesel.

Following successful abatement of external nutrient sources, one must shift the focus to the role of phosphorus (P) release from sediment. This enables us to better assess the causes for sustained eutrophication in freshwater ecosystem and how to deal with this challenge. In this study, five sediment cores from the shallow YuQiao Reservoir in northern China were investigated. The reservoir serves as the main raw water source for tap water services of Tianjin megacity, with a population of 15.6 million. Sediment characteristics and P fractions were determined in order to assess the role of the sediments as the P source to the water body. The total P content (TP) in sediments was similar to what was found in catchment soils, although the P sorption capacity of sediments was 7–10 times greater than for the catchment soils. Isotherm adsorption experiments documented that when P concentration in overlying water drops below 0.032–0.070 mg L−1, depending on the site, the sediment contributes with a positive flux of P to the overlying water. Adsorbed P at different depths in the sediments is found to be released with a similarly rapid release rate during the first 20 h, though chronic release was observed mainly from the top 30 cm of the sediment core. Dredging the top 30 cm layer of the sediments will decrease the level of soluble reactive phosphate in the water being sustained by the sediment flux of P.