Effects of plant community structural characteristics on carbon sequestration in urban green spaces.

The structural characteristics of plant communities in urban green spaces have a significant impact on their carbon sequestration function. In this study, comprehensive data were collected from 106 plant communities (each 20 m × 20 m) in Zhengzhou Green Expo Park. We assessed aboveground and soil carbon storage, alongside maintenance carbon emissions, to quantify carbon dynamics. Our primary objective was to establish a statistical model that correlates the structural attributes of plant communities with their total annual carbon sequestration. This model aims to provide a quantitative framework for optimizing community structures to maximize carbon sequestration in urban green spaces. The results showed that density and coverage were significantly and positively correlated with aboveground and soil carbon stocks. Density and mean height were significantly and positively correlated with maintenance carbon emissions. Density played a key structural role in regulating the total carbon sequestration of the plant communities, being 27.24 times more effective than coverage. The total annual carbon sequestration of the plant community reached an optimal value of 327.67 kg CO2-eq/y-1 at a density and cover of 0.15 and 1, respectively. This study provides valuable data for increasing the carbon sink ability of urban green spaces through plant structure regulation and supporting low-carbon development strategies in urban management.

Rubus suavissimus S. Lee Extract Alleviates Oxidative Stress and Inflammation in H2O2-Treated Retinal Pigment Epithelial Cells and in High-Fat Diet-Fed Mouse Retinas.

BACKGROUND: Age-related macular degeneration (AMD) is the most common cause of visual disorders in the aged population and is characterized by the formation of retinal pigment epithelium (RPE) deposits and dysfunction/death of the RPE and photoreceptors. It is supposed that both oxidative stress and inflammation play a critical role in the pathogenesis of AMD. The development of therapeutic strategies against oxidative stress and inflammation in AMD is urgently needed. Rubus suavissimus S. Lee (RS), a medicinal plant growing in the southwest region of China, has been used as an herbal tea and medicine for various diseases. METHODS: In this project, we evaluate the therapeutic potential of RS extract for AMD. We prepared RS extracts from dried leaves, which contained the main functional compounds. RESULTS: RS extract significantly increased cell viability, upregulated the expression of antioxidant genes, lowered the generation of malondialdehyde and reactive oxygen species, and suppressed inflammation in H2O2-treated human RPE cells. In the in vivo study, treatment with RS extract attenuated body weight gain, lowered cholesterol and triglyceride levels in the liver and serum, increased antioxidant capacity, and alleviated inflammation in the retina and RPE/choroid of mice fed a high-fat diet. CONCLUSIONS: Our findings suggest that RS extract offers therapeutic potential for treating AMD patients.

Discovery of a new polymorph of clotrimazole through melt crystallization: Understanding nucleation and growth kinetics.

Clotrimazole (CMZ) is a classical antifungal drug for studying crystallization. In this study, a new CMZ polymorph (Form 2) was discovered during the process of nucleation and growth rate determination in the melt. High-quality single crystals were grown from melt microdroplets to determine the crystal structure by x-ray diffraction. Form 2 is metastable and exhibits a disordered structure. The crystal nucleation and growth kinetics of the two CMZ polymorphs were systematically measured. Form 2 nucleates and grows faster than the existing form (Form 1). The maximum nucleation rate of Forms 1 and 2 was observed at 50 °C (1.07 Tg). The summary of the maximum nucleation rate temperature of CMZ and the other six organic compounds indicates that nucleation near Tg in the supercooled liquid is a useful approach to discovering new polymorphs. This study is relevant for the discovering new drug polymorphs through an understanding of nucleation and growth kinetics during melt crystallization.

Mesoporous acidic polymeric ionic liquids as novel solid acids for catalytic hydrolysis of ketoxime reactions.

In this study, a series of mesoporous acidic polymeric ionic liquids were successfully synthesized and characterized to explore their structures and properties. Examination of catalytic performance using cyclohexanone oxime's maximum conversion were investigated, and the Box-Behnken design was used to achieve the highest hydrolysis conversion. Excellent catalytic activity, structural stability, and an easy recovery feature were all displayed by the Poly(VBS-DVB)HSO4 catalyst. Additionally, a possible reaction pathway involving hydrogen protons was proposed for the present hydrolysis. Moreover, a series of ketoximes were also examined including acetone oxime, butanone oxime, cyclopentanone oxime and acetophenone oxime over Poly(VBS-DVB)HSO4 catalyst. The conversion of ketoxime was not less than 80.44%, and the results also demonstrated excellent catalytic performance. Synthesis of mesoporous acidic polymeric ionic catalysts with good properties would be very important for their applications.

Upgrading the peroxi-coagulation treatment of complex water matrices using a magnetically assembled mZVI/DSA anode: Insights into the importance of ClO radical.

The electrochemical technologies for water treatment have flourished over the last decades. However, it is still challenging to treat the actual complex water effluents by a single electrochemical process, often requiring coupling of technologies. In this study, an upgraded peroxi-coagulation (PC) process with a magnetically assembled mZVI/DSA anode has been devised for the first time. COD, NH3-N and total phosphorous were simultaneously and effectively removed from livestock wastewater. The advantages, influence of key parameters and evolution of electrogenerated species were systematically investigated to fully understand this novel PC process. The fluorescent substances in livestock wastewater could also be almost removed under optimal conditions (300 mA, 0.2 g ZVI particles and pH 6.8). The interaction between OH and active chlorine yielded ClO with a high steady-state concentration of 6.85 × 10-13 M, which did not cause COD removal but accelerated the oxidation of NH3-N. The Mulliken population suggested that OH and NH3-N had similar electron-donor behavior, whereas ClO acted as an electron-withdrawing species. Besides, although the energy barrier for the reaction between OH and NH3-N (17.0 kcal/mol) was lower than that with ClO (18.8 kcal/mol), considering the tunneling in the H abstraction reaction, the Skodje-Truhlar method adopted for calculations evidenced a 17-fold faster NH3-N oxidation rate with ClO. In summary, this work describes an advantageous single electrochemical process for the effective treatment of a complex water matrix.

The effect of adsorption and grafting on the acidity of [(HSO3)C3C1im]+[Cl]- on the surface of (SiO2)4O2H4 clusters.

Both adsorption and graft of active components on the surface of the silica are paramount methods for preparing heterogeneous catalysts. In this paper, the acidity of [(HSO3)C3C1im]+[Cl]- adsorbed and grafted on the surface of silica clusters was calculated at the level of B3LYP-d3/6-311++g(d, p). The results showed that both methods can enhance the acidity of the ionic liquids (ILs). The hydroxyl group on the carrier surface can increase the acidity, and moreover the acidity increases with the number of hydroxyl group. Besides, geometric parameters, ESP, topology and NBO analysis proved that the ILs acidity on the hydroxyl-free surface was mainly influenced by the interaction between -SO3 group and cluster surface. And yet the ILs acidity on the hydroxylated surface changes followed with the moderate strength hydrogen bond between the ILs and cluster surface.

Preparation of Ni-IL/SiO2 and its catalytic performance for one-pot sequential synthesis of 2-propylheptanol from n-valeraldehyde.

A novel silica-immobilized nickel and acid ionic liquid (Ni-IL/SiO2) catalyst was prepared by combining a bonding procedure with an impregnation operation and was characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) techniques. Its catalytic performance was evaluated for the one-pot synthesis of 2-propylheptanol (2-PH) via a sequential n-valeraldehyde self-condensation and hydrogenation reaction. As a result, Ni-IL/SiO2 showed an excellent catalytic activity for the one-pot synthesis of 2-PH, affording a 2-PH selectivity of 75.4% at a n-valeraldehyde conversion of 100% and the sum of 2-PH and pentanol selectivity reached 98.6% under the suitable reaction conditions.

Formation of CO2 bubbles in epoxy resin coatings: A DFT study.

The epoxy resin coating is a fundamental species with epoxy resins used as main components to form the final film. Unexpectedly, bulky CO2 bubbles that occasionally appeared during the curing process of epoxy resin coatings might destroy the final film properties. With an attempt to thoroughly understand the formation mechanism of CO2 bubbles and further propose countermeasures to control them, Density Function Theory (DFT) in this paper was employed to calculate the absorption process, the curing reaction and the formation mechanism of CO2 bubbles. The gas phase basicity (GB) values and pKa values of common amine curing agents were calculated. The total Gibbs free energies difference of the curing reactions between polluted curing agents and epoxy resins were calculated according to a thermodynamic cycle. Whether in gas phase or resin phase, the energetically negative ΔGsolv indicated that the curing reactions might occur spontaneously and CO2 molecules would be separated and released from amine molecules. The total Gibbs free energy calculations also revealed that the re-absorption of CO2 by the curing system was energetically unfavorable. Thus, the formation mechanism of CO2 bubbles of epoxy resin coatings could be summarize in three steps: (1) Carbon dioxide pollutes accidentally the curing agents. (2) CO2 molecules are gradually released as the curing process occurs. (3) CO2 molecules are collected to form big bubbles which can lead to seriously surface and/or internal defects. Finally, based on practical experiences three tips were proposed to control CO2 bubbles. The present results not only evidenced the nature of the unexpected bubbles of epoxy resin coatings, but also additionally paved to the way to full utilization of the formation mechanism to improve the epoxy coatings' properties.

Green synthesis of benzonitrile using ionic liquid with multiple roles as the recycling agent.

Preparation of benzonitrile from benzaldehyde and hydroxylamine hydrochloride is one of the most advantageous approaches. Nevertheless, it suffers from various constraints such as longer reaction time, corrosion and recovery of hydrochloric acid, the use of metal salt catalysts and their separation. For these reasons, a novel green benzonitrile synthetic route was proposed with ionic liquid as the recycling agent in this study. The results indicated that hydroxylamine 1-sulfobutyl pyridine hydrosulfate salt ((NH2OH)2·[HSO3-b-Py]·HSO4) was an expert alternative to hydroxylamine hydrochloride. Meanwhile, the ionic liquid [HSO3-b-Py]·HSO4 exhibited the multiple roles of co-solvent, catalysis and phase separation, thus the use of metal salt catalyst was eliminated, and no additional catalyst was needed. Hence, the separation process was greatly simplified. When the molar ratio of benzaldehyde to (NH2OH)2·[HSO3-b-Py]·HSO4 was 1 : 1.5, the volume ratio of paraxylene to [HSO3-b-Py]·HSO4 was 2 : 1, the benzaldehyde conversion and benzonitrile yield were both 100% at 120 °C in 2 h. Even better, the ionic liquid could be recovered easily by phase separation, and recycled directly after reaction. Additionally, this novel route is applicable to the green synthesis of a variety of aromatic, heteroaromatic and aliphatic nitriles with excellent yields.

A novel hydroxylamine ionic liquid salt resulting from the stabilization of NH2OH by a SO3H-functionalized ionic liquid.

A SO3H-functionalized ionic liquid was used as an alternative to conventional inorganic acids in hydroxylamine stabilization, leading to the formation of a novel hydroxylamine ionic liquid salt that exhibits improved thermal stability and reactivity in the one-step, solvent-free synthesis of caprolactam in comparison with hydroxylamine hydrochloride and hydroxylamine sulfate.

[Effects of theanine and houpu extract in 7-day chick social separation-stress procedure].

OBJECTIVE: To examine the abilities of theanine and houpu extracts (HE) to reverse behavioral indexes (separation vocalization, stress-induced analgesia and activity). METHOD: 7-day-old chicks received IP injection of theanine and HE 30 min before being tested in the presence of three social companions or in isolation for 3-min observation period. Dependent measures were: a) Chicks were placed into an infrared ray device to calculate their spontaneous activities by a computer program b) record the separation vocalizations for every chick. c) In the experiment of stress-induced analgesia, 50 uL of formalin (0.1%) was injected into the plantar of the animal foot to index stress-induced analgesia (i. e. foot-lift frequency, foot-lift duration and peck frequency). RESULT: In the experiments, isolated chicks exhibited more vocalizations (P < 0.01) and fewer pain-related behaviors than non-isolated chicks (P < 0.01). Theanine (12.5, 25, 50 mg x kg(-1)) and HE (25 mg x kg(-1)) decrease separately the tendency (dB) of the principal frequency (P < 0.05, P < 0.01); The stress induced analgesia can be reversed by theanine in 25, 50 mg x kg(-1). Both of the materials do not affect the spontaneous activities in this chick model without causing sedation. CONCLUSION: These results suggest that theanine and HE in the dosages may be useful in modulating anxiety states. They are seems no synergism in the chick model.