Research Progress on the Efficacy and Chemical Components of Medicinal Taxillus chinensis(DC.)Danser

Taxillus chinensis(DC.)Danser is a traditional Chinese medicine,which has the effects of nourishing the liver and kidney and strengthening the bones and muscles.Its properties and efficacy were recorded in many ancient Chinese herbal medicine books and modern books.In addition,other parasitic plants of the Loranthaceae family also have the effects of promoting blood circulation,checking diarrhea,and resisting tumor to treat various diseases.This paper reviewed recent scholars’research on the efficacy and chemical composition of medicinal Loranthaceae plants,and expounded the similarities and differences between T.chinensis and other medicinal Loranthaceae plants.

Soil organic carbon dynamics study bias deduced from isotopic fractionation in corn plant

Carbon stable isotope techniques were extensively employed to trace the dynamics of soil organic carbon(SOC)across a land-use change involving a shift to vegetation with different photosynthetic pathways.Based on the isotopic mass balance equation,relative contributions of new versus old SOC,and SOC turnover rate in corn fields were evaluated world-wide.However,most previous research had not analyzed corn debris left in the field,instead using an average corn plant δ^(13)C value or a measured value to calculate the proportion of corn-derived SOC,either of which could bias results.This paper carried out a detailed analysis of isotopic fractionation in corn plants and deduced the maximum possible bias of SOC dynamics study.The results show approximately 3‰ isotopic fractionation from top to bottom of the corn leaf.The ^(13)C enrichment sequence in corn plant was tassel﹥stalk or cob﹥root﹥leaves.Individual parts accounting for the total dry mass of corn returned distinct values.Consequently,the average δ^(13)C value of corn does not represent the actual isotopic composition of corn debris.Furthermore,we deduced that the greater the fractionation in corn plant,the greater the possible bias.To alleviate bias of SOC dynamics study,we suggest two measures:analyze isotopic compositions and proportions of each part of the corn and determine which parts of the corn plant are left in the field and incorporated into SOC.

Survey and Analysis on Undergraduate Tea Consumption and Attitude towards Tea Consumption

Based on the sample survey of undergraduates from Tsinghua University, Northwest Sci-Tech University of Agriculture and Forestry, Yunnan University and Yunnan Agricultural University, this paper analyzes their tea consumption and attitude towards tea consumption. Results show that more than 50% undergraduates like drinking tea, especially green tea. They would like to accept lower price tea, prefer quality to brand, and have higher degree of approval of new methods of tea drinking and tea products. However, most undergraduates lack relevant knowledge about identifying tea quality. Finally, it presents recommendations for expanding tea consumption market among undergraduates.

Aqueous-phase formation of N-containing secondary organic compounds affected by the ionic strength

The reaction of carbonyl-to-imine/hemiaminal conversion in the atmospheric aqueous phase is a critical pathway to produce the light-absorbing N-containing secondary organic compounds(SOC).The formation mechanism of these compounds has been wildly investigated in bulk solutions with a low ionic strength.However,the ionic strength in the aqueous phase of the polluted atmosphere may be higher.It is still unclear whether and to what extent the inorganic ions can affect the SOC formation.Here we prepared the bulk solution with certain ionic strength,in which glyoxal and ammonium were mixed to mimic the aqueous-phase reaction.Molecular characterization by High-resolution Mass Spectrometry was performed to identify the N-containing products,and the light absorption of the mixtures was measured by ultraviolet-visible spectroscopy.Thirty-nine N-containing compounds were identified and divided into four categories(N-heterocyclic chromophores,high-molecular-weight compounds with N-heterocycle,aliphatic imines/hemiaminals,and the unclassified).It was observed that the longer reaction time and higher ionic strength led to the formation of more N-heterocyclic chromophores and the increasing of the lightabsorbance of the mixture.The added inorganic ions were proposed to make the aqueous phase somewhat viscous so that the molecules were prone to undergo consecutive and intramolecular reactions to form the heterocycles.In general,this study revealed that the enhanced ionic strength and prolonged reaction time had the promotion effect on the lightabsorbing SOC formation.It implies that the aldehyde-derived aqueous-phase SOC would contribute more light-absorbing particulate matter in the industrial or populated area where inorganic ions are abundant.

Online single particle measurement of fireworks pollution during Chinese New Year in Nanning

Time-resolved single-particle measurements were conducted during Chinese New Year in Nanning, China. Firework displays resulted in a burst of SO2, coarse mode, and accumulation mode （100-500 nm） particles. Through single particle mass spectrometry analysis, five different types of particles （fireworks-metal, ash, dust, organic carbon-sulfate （OC-sulfate）, biomass burning） with different size distributions were identified as primary emissions from firework displays. The fireworks-related particles accounted for more than 70% of the total analyzed particles during severe firework detonations. The formation of secondary particulate sulfate and nitrate during firework events was investigated on single particle level. An increase of sulfite peak （80SO3） followed by an increase of sulfate peaks （97HSO7＋96SO7） in the mass spectra during firework displays indicated the aqueous uptake and oxidation of SO2 on particles. High concentration of gaseous SO2, high relative humidity and high particle loading likely promoted SO2 oxidation. Secondary nitrate formed through gas-phase oxidation of NO2 to nitric acid, followed by the condensation into particles as ammonium nitrate. This study shows that under worm, humid conditions, both primary and secondary aerosols contribute to the particulate air pollution during firework displays.

Enrichment and transfer of polycyclic aromatic hydrocarbons (PAHs) through dust aerosol generation from soil to the air

Polycyclic aromatic hydrocarbons(PAHs)are major organic pollutants in soil.It is known that they are released to the atmosphere by wind via dust aerosol generation.However,it remains unclear how these pollutants are transferred through the air/soil interface.In this study,dust aerosols were generated in the laboratory using soils(sandy loam and loam)with various physicochemical properties.The PAH concentrations of these soils and their generated dust aerosol were measured,showing that the enrichment factors(EFs)of PAHs were affected by soil texture,PAH contamination level,molecular weight of PAH species and aerosol sizes.The PAHs with higher EFs(6.24–123.35 in dust PM_(2.5);7.02–47.65 in dust PM_(10))usually had high molecular weights with more than four aromatic rings.In addition,the positive correlation between EFs of PAHs and the total OCaerosol content of dust aerosol in different particle sizes was also statistically significant(r=0.440,P<0.05).This work provides insights into the relationship between atmospheric PAHs and the contaminated soils and the transfer process of PAHs through the soil-air interface.

Insights into the formation of secondary organic carbon in the summertime in urban Shanghai

To investigate formation mechanisms of secondary organic carbon（SOC） in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O3 concentrations（daily peak 〉 120 ppb） was observed, during which daily maximum SOC concentrations exceeding 9.0 μg/（C·m^3）. Diurnal variations of SOC concentration and SOC/organic carbon（OC） ratio exhibited both daytime and nighttime peaks. The SOC concentrations correlated well with Ox（= O3＋ NO2） and relative humidity in the daytime and nighttime, respectively, suggesting that secondary organic aerosol formation in Shanghai is driven by both photochemical production and aqueous phase reactions. Single particle mass spectrometry was used to examine the formation pathways of SOC. Along with the daytime increase of SOC, the number fraction of elemental carbon（EC） particles coated with OC quickly increased from 38.1% to 61.9% in the size range of 250–2000 nm, which was likely due to gas-to-particle partitioning of photochemically generated semi-volatile organic compounds onto EC particles. In the nighttime, particles rich in OC components were highly hygroscopic, and number fraction of these particles correlated well with relative humidity and SOC/OC nocturnal peaks. Meanwhile, as an aqueous-phase SOC tracer, particles that contained oxalate-Fe（III） complex also peaked at night. These observations suggested that aqueous-phase processes had an important contribution to the SOC nighttime formation. The influence of aerosol acidity on SOC formation was studied by both bulk and single particle level measurements, suggesting that the aqueous-phase formation of SOC was enhanced by particle acidity.

Online single particle analysis of chemical composition and mixing state of crop straw burning particles： from laboratory study to field measurement

Fresh straw burning （SB） particles were generated in the laboratory by the combustion of rice straw and corn straw. The chemical composition and mixing state of the fresh SB particles were investigated by an Aerosol Time-of-Flight Mass Spectrometer （ATOFMS）. Based on the mass spectral patterns, the SB particles were clustered into four major types： Salt, Organic Carbon （OC）, Elemental Carbon （EC）, and internally mixed particles of EC and OC （EC-OC）. In addition, particles containing ash, polycyclic aromatic hydrocarbons, heavy metals or nicotine were also observed. Physical and chemical changes of the SB particles immediately after the emission were analyzed with highly time-resolved data. During the aging processes, the average particle size increased steadily. Freshly emitted organic compounds were gradu- ally oxidized to more oxygenated compounds in the OC- containing particles. Meanwhile, an important displace- ment reaction （2KCI＋ SO24- KzSO4 ＋ 2C1-） was observed. The marker ions for SB particles were optimized and applied to identify the SB particles in the ambient atmosphere. The fluctuation of the number fraction of ambient SB particles sorted by ATOFMS agrees well with that of water soluble K＋ measured by an online ion chromatography, demonstrating that the optimized marker ions could be good tracers for SB particles in field measurements.

催化臭氧净水过程中催化材料晶面的作用

非均相臭氧催化氧化(heterogeneous catalytic ozonation,HCO)技术在难降解有机物去除和提高废水可生化性方面应用广泛.非均相金属氧化物是稳定有效的HCO材料.通过晶面调控手段,可改变金属氧化物催化材料表面原子排列顺序,从而暴露出特定晶面.晶体暴露的晶面种类与比例可显著影响HCO过程中臭氧(O3)分解、污染物降解及消毒副产物生成效率.本文在实验结果和理论研究进展的基础上,系统综述了晶面调控HCO催化材料的合成方法与控制机理、强化HCO过程的增强机理以及其在水处理中的应用,如污染物降解、灭菌及副产物毒性抑制等.最后,针对晶面调控HCO催化材料现有研究的不足和实际应用所面临的挑战,从机理探索和材料开发两方面进行了展望.

Polydopamine functionalized mesoporous silica as ROS-sensitive drug delivery vehicles for periodontitis treatment by modulating macrophage polarization

Periodontitis is recognized as the major cause of tooth loss in adults, posing an adverse impact on systemic health. In periodontitis, excessive production of reactive oxygen species (ROS) at the inflamed site culminates in periodontal destruction. In this study, a novel ROS-responsive drug delivery system based on polydopamine (PDA) functionalized mesoporous silica nanoparticles was developed for delivering minocycline hydrochloride (MH) to treat periodontitis. The outer PDA layer and the inner MH of the nanoparticles acted as ROS scavengers and anti-inflammatory agents, respectively. Under the synergistic action of PDA and MH, macrophages were polarized from the pro-inflammatory M1 to the anti-inflammatory M2 phenotype. The in vitro experiments provided convincing evidence that PDA could scavenge ROS effectively, and the expression of pro-inflammatory cytokines was attenuated and the secretion of anti-inflammatory cytokines was enhanced through M1 to M2 polarization of macrophages with the cooperation of MH. In addition, the results obtained from the periodontitis rat models demonstrated that the synergetic effect of PDA and MH prevented alveolar bone loss without causing any adverse effect. Taken together, the results from the present investigation provide a new strategy to remodel the inflammatory microenvironment by inducing the polarization of macrophages from M1 toward M2 state for the treatment of periodontitis.

Genomic surveillance of emerging SARS-CoV-2 Omicron variations in Tianjin Municipality, China 2022

The coronavirus disease 2019(COvID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has severely impacted public health.In 2022,the Omicron variant of SARS-CoV-2 rapidly became the dominant circulating variant in the local COVID-19 outbreaks in Tianjin Municipality,China.To gain a deeper understanding of the genetic variations of the Omicron variant in Tianjin,specimens from indi-viduals who tested positive for SARS-CoV-2 between December 2021 and November 2022 were used for virus whole genome sequencing and phylogenetic analysis.A total of 1,674 high-quality Omicron sequences were obtained,consisting of 1,339 sequences from local cases belonging to 20 Phylogenetic Assignment of Named Global Outbreak(PANGO)lineages and 335 sequences from imported cases belonging to 70 lineages.Tianjin experienced five waves of local outbreaks,accompanied by multiple substitutions among subvariants,ranging from the initial BA.1.1 lineage to the subsequent BA.2,BF.7,and BA.5.2 lineages.The evolutionary rate of local strains,estimated to be 28.999 substitutions per year,and the evolutionary rate of imported strains,estimated to be 24.946 substitutions per year,were lower than that of the strains circulating globally.The addi-tional substitutions and deletions of local strains have been used to identify and disrupt the virus transmission chains.The subvariants such as BA.5.2.48,BA.5.2.49,BF.7.14,and XBB.1 circulating in the fifth epidemic wave presented criterial immune escape mutations including S:R346T,S:L452R and S:F486V.It is essential to implement genomic surveillance strategies to investigate further the development of genomic mutation char-acteristics in the SARS-CoV-2 variant.This ongoing monitoring will contribute to a better understanding of the virus's genetic changes and aid in effective control measures.