Camelliazijinica (Theaceae), a new species endemic to Danxia landscape from Guangdong Province, China.

A new species of the genus Camellia (Theaceae), Camelliazijinica, discovered in the Danxia landscape from Guangdong Province, China, is characterized and illustrated. Phylogenetic analysis based on chloroplast genomes suggested its affinity with C.drupifera, C.oleifera and C.fluviatilis, however, it morphologically differs from all of the latter by leaf shape and size. Phonologically, it most closely resembles C.microphylla, but can be distinguished from the latter by its young branchlets glabrous (vs. densely pubescent), fewer bracteoles and sepals, diverse leaf shape, midvein raised slightly with sparsely pubescent or glabrous (vs. prominently with densely pubescent) and leaf adaxially matt (vs. vernicose) when dried. By morphological and molecular analyses, Camelliazijinica represented a distinct new species of C.sect.Paracamellia.

A full-scale black soldier fly larvae (Hermetia illucens) bioconversion system for domestic biodegradable wastes to resource.

Domestic biodegradable wastes (DBW) pose a threat to environmental quality and human health. Bioconversion via black soldier fly larvae (BSFL; Hermitia illucens L.) is an expedient way for converting 'waste to resource' (insect protein and biofertilizer). Although researches abounded in laboratory-reared experiments and bioconversion mechanisms were pertinent, the void of data from actual and full-scale operation restricts the intensification of BSFL technology and its global adoption. Hence, a full-scale BSFL bioconversion system lasting 4 years in Hangzhou (China) was investigated, and the feasibility and efficiency of 15 tonnes of DBW per day were studied. Through continuous technical optimization, the average production of fresh larvae was increased from 8.5% in 2017 to 15.3% in 2020, along with bioconversion rate of final vermicompost decreased from 35.4% to 14.5%. The total biomass reduction rate in 2020 was 68.7 ± 17.4 kg/(m3 d), equivalent to 0.735 ± 0.215 kg/(kg d) in the form of fresh larvae. Crude fat in fresh larvae accounted for 13.4%, and crude protein accounted for 16.2% in which the determined amino acid profile bore a strong resemblance to fish meal only except histidine and tyrosine. Its economic benefits proved the feasibility of this technology, and the profit reached up to 35.9 US$ per tonne of DBW in 2019. In conclusion, BSFL bioconversion system under current 'insect-farm' operation was a promising solution for DBW treatment with value-added waste recycling.

Insights on dissolved organic matter and bacterial community succession during secondary composting in residue after black soldier fly larvae (Hermetia illucens L.) bioconversion for food waste treatment.

Black soldier fly larvae (Hermetia illucens L. BSFL) bioconversion is a promising biotechnology for food waste treatment. However, the separated residues still do not meet criteria for use as land application biofertilizers. In this work, we investigated a full-scale BSFL bioconversion project to explore features of dissolved organic matter (DOM) and its associated responses of bacterial community succession in residue during secondary composting. Data showed that the concentrations of total nitrogen and ammonium nitrogen decreased by 11.8% and 22.6% during the secondary composting, respectively, while the nitrate nitrogen concentration increased 18.7 times. The DOM concentration decreased by 69.1%, in which protein-like, alcohol-phenol, and biodegradable aliphatic substances were metabolized by bacteria during the thermophilic phase together with the accumulation of humus-like substances, resulting in an increase in the relative concentration of aromatic compounds. The structure of the bacterial community varied at different stages of the bioprocess, in which Bacteroidetes, Actinobacteria, Proteobacteria, and Firmicutes were the dominant bacterial phyla. Lysinibacillus, Pusillimonas, and Caldicoprobacter were found to be key contributors in the degradation and formation of DOM. The DOM concentration (33.4%) and temperature (17.7%) were the prime environmental factors that promoted succession of the bacterial community. Through bacterial metabolism, the structural stability of DOM components was improved during the composting process, and the degrees of humification and aromaticity were also increased. This study depicted the dynamic features of DOM and the associated bacterial community succession in residue during secondary composting, which is conducive with the reuse of BSFL residue as biofertilizer for agriculture.

Patients with SERPINC1 rs2227589 polymorphism found to have multiple cerebral venous sinus thromboses despite a normal antithrombin level: A case report.

BACKGROUND: The hereditary antithrombin (AT) deficiency caused by SERPINC1 gene mutation is an autosomal dominant thrombotic disorder. An increasing number of studies have shown that mutations in the SERPINC1 rs2227589 polymorphic site are correlated with a risk of venous thromboembolism (VTE) at common sites, such as lower extremity deep venous thrombosis and pulmonary thromboembolism. Currently, there are no reports of cerebral venous sinus thrombosis (CVST), a VTE site with a low incidence rate and rs2227589 polymorphism. CASE SUMMARY: Here, we report a Chinese CVST case with a mutation of the SERPINC1 rs2227589 polymorphic site, which did not cause significant AT deficiency. In a 50-year-old male patient presenting with multiple cerebral venous sinus thromboses no predisposing factors were detected, although a relative had a history of lower extremity deep venous thrombosis. We performed sequencing of the SERPINC1 gene for the patient and his daughter, which revealed the same heterozygous mutation at the rs2227589 polymorphic site: c.41+141G>A. CONCLUSION: The results showed that more studies should be conducted to assess the correlation between rs2227589 polymorphism and CVST.

Continental-Scale Paddy Soil Bacterial Community Structure, Function, and Biotic Interaction.

Rice paddy soil-associated microbiota participate in biogeochemical processes that underpin rice yield and soil sustainability, yet continental-scale biogeographic patterns of paddy soil microbiota remain elusive. The soil bacteria of four typical Chinese rice-growing regions were characterized and compared to those of nonpaddy soils. The paddy soil bacteria were significantly less diverse, with unique taxonomic and functional composition, and harbored distinct cooccurrence network topology. Both stochastic and deterministic processes shaped soil bacteria assembly, but paddy samples exhibited a stronger deterministic signature than nonpaddy samples. Compared to other environmental factors, climatic factors such as mean monthly precipitation and mean annual temperature described most of the variance in soil bacterial community structure. Cooccurrence network analysis suggests that the continental biogeographic variance in bacterial community structure was described by the competition between two mutually exclusive bacterial modules in the community. Keystone taxa identified in network models (Anaerolineales, Ignavibacteriae, and Deltaproteobacteria) were more sensitive to changes in environmental factors, leading us to conclude that environmental factors may influence paddy soil bacterial communities via these keystone taxa. Characterizing the uniqueness of bacterial community patterns in paddy soil (compared to nonpaddy soils) at continental scales is central to improving crop productivity and resilience and to sustaining agricultural soils. IMPORTANCE Rice fields provide food for over half of the world's human population. The ecology of paddy soil microbiomes is shaped by human activities, which can have a profound impact on rice yield, greenhouse gas emissions, and soil health. Investigations of the soil bacteria in four typical Chinese rice-growing regions showed that (i) soil bacterial communities maintain highly modularized species-to-species network structures; (ii) community patterns were shaped by the balance of integrated stochastic and deterministic processes, in which homogenizing selection and dispersal limitation dominate; and (iii) deterministic processes and climatic and edaphic factors influence community patterns mainly by their impact on highly connected nodes (i.e., keystone taxa) in networks. Characterizing the unique ecology of bacterial community patterns in paddy soil at a continental scale may lead to improved crop productivity and resilience, as well as sustaining agricultural soils.

Dual targeting of MEK and PI3K effectively controls the proliferation of human EGFR-TKI resistant non-small cell lung carcinoma cell lines with different genetic backgrounds.

BACKGROUND: Molecular targeted therapy for non-small cell lung carcinoma (NSCLC) is restricted due to resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). This study evaluated the effects of dual targeting of MEK and PI3K in human EGFR-TKI resistant NSCLC cell lines. METHODS: EGFR-TKI resistant NSCLC cell lines H1975, H460, and A549, with different mutation and amplification status in EGFR, K-RAS, PIK3CA, and MET genes, were treated with a MEK162 (MEK inhibitor) and BKM120 (PI3K inhibitor) combination or a BIBW2992 (EGFR inhibitor) and ARQ197 (MET inhibitor) combination and assayed for cell proliferation, apoptosis, and cell cycle distribution. RESULTS: Dual targeting of MEK and PI3K efficiently inhibited the cell proliferation, induced apoptosis and the G0/G1 cell cycle, and decreased the phosphorylation of ERK1/2, AKT, S6, and 4E-BP1. H460 cells with K-RAS and PIK3CA mutation were most sensitive to MEK162 and BKM120 combinations. H1975 cells with EGFR and PIK3CA mutation and MET amplification were sensitive to BIBW2992 and ARQ197 combinations. CONCLUSION: Dual targeting regulated the proliferation of EGFR-TKI-resistant NSCLC cells, especially mutants in K-RAS and PIK3CA that are promising for EGFR-TKI-resistant NSCLC therapeutics.

The unique molecular mechanism of diabetic nephropathy: a bioinformatics analysis of over 250 microarray datasets.

BACKGROUND/AIMS: Diabetic nephropathy (DN) is one of the main causes of end-stage kidney disease worldwide. Emerging studies have suggested that its pathogenesis is distinct from nondiabetic renal diseases in many aspects. However, it still lacks a comprehensive understanding of the unique molecular mechanism of DN. METHODS: A total of 255 Affymetrix U133 microarray datasets (Affymetrix, Santa Calra, CA, USA) of human glomerular and tubulointerstitial tissues were collected. The 22 215 Affymetrix identifiers shared by the Human Genome U133 Plus 2.0 and U133A Array were extracted to facilitate dataset pooling. Next, a linear model was constructed and the empirical Bayes method was used to select the differentially expressed genes (DEGs) of each kidney disease. Based on these DEG sets, the unique DEGs of DN were identified and further analyzed using gene ontology and pathway enrichment analysis. Finally, the protein-protein interaction networks (PINs) were constructed and hub genes were selected to further refine the results. RESULTS: A total of 129 and 1251 unique DEGs were identified in the diabetic glomerulus (upregulated n = 83 and downregulated n = 203) and the diabetic tubulointerstitium (upregulated n = 399 and downregulated n = 874), respectively. Enrichment analysis revealed that the DEGs in the diabetic glomerulus were significantly associated with the extracellular matrix, cell growth, regulation of blood coagulation, cholesterol homeostasis, intrinsic apoptotic signaling pathway and renal filtration cell differentiation. In the diabetic tubulointerstitium, the significantly enriched biological processes and pathways included metabolism, the advanced glycation end products-receptor for advanced glycation end products signaling pathway in diabetic complications, the epidermal growth factor receptor (EGFR) signaling pathway, the FoxO signaling pathway, autophagy and ferroptosis. By constructing PINs, several nodes, such as AGR2, CSNK2A1, EGFR and HSPD1, were identified as hub genes, which might play key roles in regulating the development of DN. CONCLUSIONS: Our study not only reveals the unique molecular mechanism of DN but also provides a valuable resource for biomarker and therapeutic target discovery. Some of our findings are promising and should be explored in future work.

Correction to: The chemodiversity of paddy soil dissolved organic matter correlates with microbial community at continental scales.

An amendment to this paper has been published and can be accessed via the original article.

Considerations for head and neck oncology practices during the coronavirus disease 2019 (COVID-19) pandemic: Wuhan and Toronto experience.

The practices of head and neck surgical oncologists must evolve to meet the unprecedented needs placed on our health care system by the Coronavirus disease 2019 (COVID-19) pandemic. Guidelines are emerging to help guide the provision of head and neck cancer care, though in practice, it can be challenging to operationalize such recommendations. Head and neck surgeons at Wuhan University faced significant challenges in providing care for their patients. Similar challenges were faced by the University of Toronto during the severe acute respiratory syndrome (SARS) pandemic in 2003. Herein, we outline our combined experience and key practical considerations for maintaining an oncology service in the midst of a pandemic.

Pyrola incarnata demonstrates neuroprotective effects against ß-amyloid-induced memory impairment in mice.

This study aims to investigate the neuroprotective effects of Pyrola incarnata against ß-amyloid-induced memory impairment in mice. Ethanol extract of Pyrola incarnata (EPI) was obtained and led to eleven phytochemicals successfully by isolation and purification, which were elucidated by spectroscopic analysis (1H NMR, 13C NMR and HR-ESI-MS). Thereinto, ursolic acid was gained as most abundant monomer. C57BL/6 mice were intracerebroventricular injected with aggregated Aß25-35. Open-field test, Barnes maze test and Morris water maze were conducted for evaluating cognition processes of EPI and ursolic acid. EPI significantly improved learning and memory deficits, attenuated the Aß25-35 level of deposition immunohistochemically. Further studies revealed that ursolic acid as bioactive phytochemical of P. incarnata improved spatial memory performance and ameliorated Aß25-35 accumulation by activating microglia cells and up-regulating Iba1 level in the hippocampus. These findings suggest P. incarnata could improve the cognition of mice and be a promising natural source for the treatment of neurodegenerative disease.

The impact and mechanism of quaternary ammonium compounds on the transmission of antibiotic resistance genes.

The emergence of antibiotic resistance genes (ARGs) in microbes can be largely attributed to the abuse and misuse of antibiotics and biocides. Quaternary ammonium compounds (QACs) have been used worldwide as common disinfectants and detergents; however, their potential impact on the spread and diffusion of ARGs is still unknown. In this study, we detected the QAC resistance gene (qacEΔ1), the 1 integron gene (intI1), and 12 ARGs (sul1, sul2, cfr, cml, fexA, tetA, tetG, tetQ, tetX, ermB, blaTEM, and dfrA1) in 48 water samples from three watersheds by quantitative PCR (qPCR). We investigated the evolution of bacterial antibiotic resistance under QAC and antibiotic environmental pressures by long-term continuous culture. In addition, five QACs were selected to investigate the effect of QAC on the efficiency of conjugation transfer. The changes in bacterial cell membrane and production of reactive oxygen species (ROS) were detected by flow cytometry, revealing the mechanism by which QAC affects the spread of antibiotic resistance. Our results showed that the QAC resistance gene was ubiquitous in watersheds and it had significant correlation with intI1 and seven ARGs (r = 0.999, p < 0.01). QACs could increase the resistance of bacteria to multiple antibiotics. Furthermore, all five QACs promoted the conjugation transfer of the RP4 plasmid; the optimal concentration of QACs was about 10-1-10-2 mg/L and their transfer efficiencies were between 1.33 × 10-6 and 8.87 × 10-5. QACs enhanced membrane permeability of bacterial cells and stimulated bacteria to produce ROS, which potentially promoted the transfer of plasmids between bacteria. In conclusion, this study demonstrated that QACs may facilitate the evolution and gene transfer of antibiotic resistance gene among microbiome.

Black soldier fly larvae (Hermetia illucens) strengthen the metabolic function of food waste biodegradation by gut microbiome.

Vermicomposting using black soldier fly (BSF) larvae (Hermetia illucens) has gradually become a promising biotechnology for waste management, but knowledge about the larvae gut microbiome is sparse. In this study, 16S rRNA sequencing, SourceTracker, and network analysis were leveraged to decipher the influence of larvae gut microbiome on food waste (FW) biodegradation. The microbial community structure of BSF vermicompost (BC) changed greatly after larvae inoculation, with a peak colonization traceable to gut bacteria of 66.0%. The relative abundance of 11 out of 21 metabolic function groups in BC were significantly higher than that in natural composting (NC), such as carbohydrate-active enzymes. In addition, 36.5% of the functional genes in BC were significantly higher than those in NC. The changes of metabolic functions and functional genes were significantly correlated with the microbial succession. Moreover, the bacteria that proliferated in vermicompost, including Corynebacterium, Vagococcus, and Providencia, had strong metabolic abilities. Systematic and complex interactions between the BSF gut and BC bacteria occurred over time through invasion, altered the microbial community structure, and thus evolved into a new intermediate niche favourable for FW biodegradation. The study highlights BSF gut microbiome as an engine for FW bioconversion, which is conducive to bioproducts regeneration from wastes.

The chemodiversity of paddy soil dissolved organic matter correlates with microbial community at continental scales.

BACKGROUND: Paddy soil dissolved organic matter (DOM) represents a major hotspot for soil biogeochemistry, yet we know little about its chemodiversity let alone the microbial community that shapes it. Here, we leveraged ultrahigh-resolution mass spectrometry, amplicon, and metagenomic sequencing to characterize the molecular distribution of DOM and the taxonomic and functional microbial diversity in paddy soils across China. We hypothesized that variances in microbial community significantly associate with changes in soil DOM molecular composition. RESULTS: We report that both microbial and DOM profiles revealed geographic patterns that were associated with variation in mean monthly precipitation, mean annual temperature, and pH. DOM molecular diversity was significantly correlated with microbial taxonomic diversity. An increase in DOM molecules categorized as peptides, carbohydrates, and unsaturated aliphatics, and a decrease in those belonging to polyphenolics and polycyclic aromatics, significantly correlated with proportional changes in some of the microbial taxa, such as Syntrophobacterales, Thermoleophilia, Geobacter, Spirochaeta, Gaiella, and Defluviicoccus. DOM composition was also associated with the relative abundances of the microbial metabolic pathways, such as anaerobic carbon fixation, glycolysis, lignolysis, fermentation, and methanogenesis. CONCLUSIONS: Our study demonstrates the continental-scale distribution of DOM is significantly correlated with the taxonomic profile and metabolic potential of the rice paddy microbiome. Abiotic factors that have a distinct effect on community structure can also influence the chemodiversity of DOM and vice versa. Deciphering these associations and the underlying mechanisms can precipitate understanding of the complex ecology of paddy soils, as well as help assess the effects of human activities on biogeochemistry and greenhouse gas emissions in paddy soils.

Estimation of the status of spiral ganglion neurons and Schwann cells in the auditory neural degeneration mouse using the auditory brainstem response.

CONCLUSION: The auditory brainstem response (ABR) wave I threshold, latency and amplitude are insensitive to spiral ganglion neurons (SGNs) degeneration, but are sensitive to the degeneration of Schwann cells and can estimate the status of Schwann cells in a neural degeneration mouse model. The thorough pre-operative ABR assessment would be helpful in predicting cochlear implant performance. OBJECTIVES: This study aimed in finding a non-invasive electrophysiological method to evaluate the status of the auditory nerve and the Schwann cells in sensorineural hearing loss (SNHL) and auditory neuropathy (AN) ears, and providing useful information for candidates screening and outcome prediction in cochlear implantation. METHODS: The frequency-specific acoustic ABR was recorded in mice. The immunohistochemical staining was performed to detect the SGNs and Schwann cells in mice cochlea. The correlations between ABR wave I metrics and SGNs, Schwann cells were investigated. RESULTS: In SNHL and AN mice cochlea, statistically significant correlations between ABR wave I thresholds, latencies and amplitudes at 8, 16, and 32 kHz and their corresponding SGNs densities were found only in wave I amplitude at 8 kHz. While the ABR wave I metrics at all three frequencies showed strong significant correlations with their corresponding Schwann cells densities.

Effect of Calcium-sensing Receptor on the Apoptosis of Rat Spinal Cord Neurons in Anoxia/Reoxygenation Injury and Its Significance.

Objective To investigate the effect and significance of calcium-sensing receptor (CaSR) on the apoptosis of rat spinal cord neurons in anoxia/reoxygenation(A/R) injury. Methods The spinal cells were in ischemia and hypoxia environment for 1 h and in normal environment for 24 h to establish a model of A/R. After spinal A/R model was established,the spinal cells were divided into four groups randomly:the control group,A/R group,A/R+GdCl3 group,and A/R+NPS-2390 group. The expression of CaSR in each group was detected by immunofluorescence and Western blotting. The concentration of intracellular calcium was measured by laser confocal scanning microscopy. The expressions of Caspase-3,Bax,and Bcl-2 were detected by using Western blotting. The apoptotic rate of spinal cells was detected by Tunel assay. Results Compared to the control group, there was a significant increase in the level of CaSR (t=5.462, P=0.006), the concentration of intracellular calcium (t=8.573, P=0.001), the apoptotic rate (t=4.899, P=0.008), Caspase-3 (t=5.118, P=0.007), and Bax (t=10.930,P=0.001) in A/R group. Compared to the A/R group, there was a significant increase in the level of CaSR (t=4.975, P=0.008),the concentration of intracellular calcium (t=4.899, P=0.008), the apoptotic rate (t=7.746, P=0.002), Caspase-3 (t=4.776, P=0.009), and Bax (t=5.281, P=0.006) in A/R+GdCl3 group. Compared to the A/R group, there was a significant decrease in the level of CaSR (t=3.674,P=0.021), the concentration of intracellular calcium (t=3.846, P=0.018), the apoptotic rate (t=4.281,P=0.013), Caspase-3 (t=3.521, P=0.024), and Bax(t=3.473, P=0.026) in A/R+NPS-2390 group. However, compared to the control group, there was a significant decrease in the level of Bcl-2 (t=6.242,P=0.003) in A/R group. Compared to the A/R group, there was a significant decrease in the level of Bcl-2(t=3.028, P=0.004) in A/R+GdCl3 group. Compared to the A/R group, there was a significant increase in the level of Bcl-2 (t=2.840, P=0.047) in A/R+NPS-2390 group.Conclusion During the process of A/R injury in rat spinal cord neurons,the expression of calcium sensing receptor increases,along with increase in intracellular calcium and spinal neuron apoptosis.

[Effective Prevention of Acute Hemolytic Transfusion Reaction again by Blood Matching of in vitro Hemolytic Test].

OBJECTIVE: To screen out the suitable erythrocytes compatible to the results from the routine blood matching for the patients suffered from the relapse of acute hemolytic transfusion reaction. METHODS: The in vitro hemolysis test was used to screen out the erythrocytes from the non-hemolytic donors for the transfusion of erythrocytes into the patients. RESULTS: Three U of the non-hemolytic erythrocytes were obtained by using hemolytic test in vitro, the post-transfusion effects were good, and the hemolytic reaction will not occure once more. CONCLUSION: When it is compatible to the results obtained from the routine blood matching and the post-transfusion hemolytic reaction appeared. The blood matching by using in vitro hemolytic test can be used to screen out the non-hemolytic erythrocytes for transfusion of the patients.

Dose-dependent effects of ouabain on spiral ganglion neurons and Schwann cells in mouse cochlea.

OBJECTIVE: This study aimed in fully investigating the toxicities of ouabain to mouse cochlea and the related cellular environment, and providing an optimal animal model system for cell transplantation in the treatment of auditory neuropathy (AN) and sensorineural hearing loss (SNHL). METHODS: Different dosages of ouabain were applied to mouse round window. The auditory brainstem responses and distortion product otoacoustic emissions were used to evaluate the cochlear function. The immunohistochemical staining and cochlea surface preparation were performed to detect the spiral ganglion neurons (SGNs), Schwann cells and hair cells. RESULTS: Ouabain at the dosages of 0.5 mM, 1 mM and 3 mM selectively and permanently destroyed SGNs and their functions, while leaving the hair cells relatively intact. Ouabain at 3 mM resulted in the most severe SGNs loss and induced significant loss of Schwann cells started as early as 7 days and with further damages at 14 and 30 days after ouabain exposure. CONCLUSIONS: The application of ouabain to mouse round window induces damages of SGNs and Schwann cells in a dose- and time-dependent manner, this study established a reliable and accurate animal model system of AN and SNHL.

[Effect of Simulated Climate Warming on Microbial Community and Phosphorus Forms in Wetland Soils].

Microbial community and phosphorus forms in response to simulated climate warming were studied by high-throughput sequencing and 31P nuclear magnetic resonance(31P-NMR) respectively, which were from wetland soils in constructed microcosm columns. The results revealed that relative abundances of Firmicutes, Clostridia, Clostridiales, Clostridiaceae and Clostridium were significantly decreased by 65%-98%, 69%-87%, 67%-87%, 73%-97% and 74%-93% under warming condition respectively, suggesting warming had a significant inhibitory effect on the bacterial lineage from Firmicutes to Clostridium at different taxonomic level. Particularly, principal coordinate analysis and cluster analysis also demonstrated warming had a significant effect on microbial community structure with obvious separation of samples between control and warmed groups from each wetland column site. Phosphorus forms were dominated by phosphomonoester and orthophosphate in each wetland column soil, which were significantly increased and decreased by 275% and 20% in XX wetland column soil respectively. Similarly, phosphomonoester and polyphosphate were also found to be increased and decreased by 85% and 49% in JH wetland column soil respectively, indicating that phosphorus forms in response to warming had soil heterogeneity. Canonical correspondence analysis showed that obvious changes in microbial community composition had significant effects on phosphorus forms under warming condition.

[Spatiotemporal dynamics of atmospheric PM2.5 and PM10 and its influencing factors in Nanchang, China]. / 南昌市空气PM2.5和PM10çš„æ—¶ç©ºåŠ¨æ€åŠå ¶å½±å“å› ç´ .

PM2.5 and PM10 have become the primary pollutants of most cities in China. Atmospheric PM2.5 and PM10 mass concentrations, meteorological factors, traffic flow from 2013 to 2015 in Nanchang were analyzed. Spatiotemporal dynamic pattern of atmospheric particulate matter pollution and the effect of weather and traffic on particle concentration change were discussed in this paper. The results showed that PM2.5(70.92 µg·m-3 in 2013 > 53.70 µg·m-3 in 2014 ＞ 43.65 µg·m-3 in 2015) and PM10(119.72 µg·m-3 in 2013 ＞ 86.11 µg·m-3 in 2014 ＞ 73.32 µg·m-3 in 2015) concentrations decreased gradually from 2013 to 2015. In addition, low concentrations of PM2.5 and PM10 in summer (average PM2.5 concentration 36.74 µg·m-3, average PM10 concentration 69.20 µg·m-3) but high concentrations in winter (average PM2.5 concentration 74.29 µg·m-3, average PM10 concentration 111.64 µg·m-3) were observed. Moreover, PM2.5 and PM10 concentrations changed with the urban-rural gradient, decreasing from the city center to suburb. The ratio of PM2.5/PM10(0.595 ＞ 0.584 ＞ 0.557) decreased year by year from 2013 to 2015 and was higher in the city center area than in the edge of city. PM2.5 and PM10 concentrations were affected by various meteorological factors and significantly related to air pressure, temperature, relative humidity, wind speed, precipitation and sunshine time. The influence of meteorological factors differed on PM2.5 and PM10 concentrations. Traffic flow significantly increased the surrounding PM2.5 concentration, but not PM10 concentration.

[Stable hydrogen and oxygen isotope compositions in soil-plant-atmosphere continuum (SPAC) in rocky mountain area of Beijing, China]. / 北京土石山区水分在土壤-植物-大气连续体(SPAC)ä¸­çš„ç¨³å®šåŒä½ç´ ç‰¹å¾.

The stable hydrogen and oxygen isotopes are environmental isotopes, which widely exist in various kinds of water. Their relative abundance variation in water can indicate the water circulation and mechanism of water use in plant. This research selected two major kinds of greening tree species, evergreen coniferous Platycladus orientalis and deciduous broad-leaved Quercus variabilis, in Beijing mountainous area, and the water movement process in soil-plant-atmosphere continuum was investigated by the variation characteristics analysis of stable hydrogen and oxygen isotope compositions in precipitation, soil water, groundwater, plant stem water and leaf water. The results showed that the meteoric water line equation of the study area was δD=7.17δ18O+1.45 (R2=0.93), and the soil evaporation line equation was δD=3.85δ18O+1.45 (R2=0.76). A certain degree of evaporation fractionation existed in the processes of rainfall infiltration into soil water. In different seasons, the δD and δ18O values of precipitation, soil water and spring water had different variation regularity. In rainy season, the mean δD and δ18O values were in order of precipitation> spring water>soil water, with the precipitation and soil water supplied spring water together; in dry season, the order was precipitation > soil water > spring water, and the precipitation and spring water both contributed to soil water. The δD and δ18O fitting line equations of stem water of P. orienta-lis and Q. variabilis were respectively δD=5.03δ18O-30.78 and δD=3.0δ18O-48.92. The uptake water of Q. variabilis was more enriched than that of P. orientalis, and the depth of Q. variabilis water uptake in soil profile was shallower than P. orientalis. The leaf water isotopic variation of Q. varia-bilis was more sensitive to atmospheric environment, with the kinetic isotopic fractionation of Q. variabilis being more enriched than that of P. orientalis, but they had the same response to variation of environmental condition.