Global distribution and drivers of relative contributions among soil nitrogen sources to terrestrial plants.

Soil extractable nitrate, ammonium, and organic nitrogen (N) are essential N sources supporting primary productivity and regulating species composition of terrestrial plants. However, it remains unclear how plants utilize these N sources and how surface-earth environments regulate plant N utilization. Here, we establish a framework to analyze observational data of natural N isotopes in plants and soils globally, we quantify fractional contributions of soil nitrate (fNO3-), ammonium (fNH4+), and organic N (fEON) to plant-used N in soils. We find that mean annual temperature (MAT), not mean annual precipitation or atmospheric N deposition, regulates global variations of fNO3-, fNH4+, and fEON. The fNO3- increases with MAT, reaching 46% at 28.5 °C. The fNH4+ also increases with MAT, achieving a maximum of 46% at 14.4 °C, showing a decline as temperatures further increase. Meanwhile, the fEON gradually decreases with MAT, stabilizing at about 20% when the MAT exceeds 15 °C. These results clarify global plant N-use patterns and reveal temperature rather than human N loading as a key regulator, which should be considered in evaluating influences of global changes on terrestrial ecosystems.

Gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC) promotes oral cancer stemness by acting as a molecular sponge of miR331-3p.

Background/purpose: Accumulating evidence has suggested that treatment failure of cancer therapy can be attributed to cancer stem cells (CSCs). Among numerous regulators of cancer stemness, non-coding RNAs (ncRNAs) have gained significant attention recently. In this study, we examined the role of gastric adenocarcinoma predictive long intergenic noncoding RNA (GAPLINC) in oral CSCs (OCSCs). Materials and methods: RNA Sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the expression of GAPLINC. Flow cytometry and sphere-forming assay were exploited to isolate OCSCs. Measurement of aldehyde dehydrogenase 1 (ALDH1) activity, CD44 expressing cells, and various phenotypic assays, such as self-renewal, migration, invasion, and colony-forming abilities, were conducted in CSCs of two types of oral cancer cells (SAS and GNM) following the knockdown of GAPLINC. A luciferase reporter was also carried out to validate the direct interaction between GAPLINC and microRNA (miR)-331-3p. Results: Our results showed that GAPLINC was overexpressed in OCSCs from patient-derived and oral cancer cell lines. We demonstrated that silencing of GAPLINC in OCSCs downregulated various CSC hallmarks, such as ALDH1 activity, percentage of CD44-expressing cells, self-renewal capacity, and colony-forming ability. Moreover, our results revealed that the effect of GAPLINC on cancer stemness was mediated by direct repression of miR-331-3p. Conclusion: These data have potential clinical implications in that we unraveled the aberrant upregulation of GAPLINC and demonstrated that suppression of GAPLINC may reduce cancer stemness via sequestering miR-331-3p.

Diurnal predators in dim light: the ability of mantids to prey for supper.

Many insects rely heavily on visual cues in foraging and other life activities. Mantids are insect predators that usually ambush prey. The sophisticated visual system of mantids allows them to spot, track, and strike at prey with high accuracy. Mantids are categorized as diurnal animals in most cases, while our field observations suggested that they were active in foraging both day and night. Therefore, we hypothesize that predation in dim light is possible for mantids, while mantids are unable to capture prey in complete darkness. In this study, we experimentally examined whether different light conditions could affect the predation success and efficiency of mantid nymphs and adults, Hierodula chinensis Werner (Mantodea: Mantidae), through behavioral observations. Individual mantids were placed in individual chambers in complete darkness, simulated moonlight (0.1 lux), or simulated dusk (50 lux) conditions and were allowed to forage for prey items for 10 min. Our observations showed no evidence that H. chinensis could capture any prey in complete deprivation of light. The proportion of nymphs with successful predation in simulated moonlight was 50% higher than that in complete darkness and 45.83% lower than that in simulated dusk. The proportion of adults with successful predation in simulated moonlight was 42.11% higher than that in complete darkness and 57.89% lower than that in simulated dusk. Overall, the results provide new insights into the behavioral ecology of diurnal predators at night, with potential association with moonlight, starlight, and light pollution.

LINC01296 promotes cancer stemness traits in oral carcinomas by sponging miR-143.

Background/purpose: Emerging evidence has shown that various failures in cancer therapy, such as drug resistance, metastasis, and cancer relapse are attributed to cancer stem cells (CSCs). Also, growing attention has been paid to the regulation of non-coding RNAs in cancer stemness. Here, we aimed to investigate the contribution of LINC01296 in the modulation of oral CSCs. Materials and methods: The phenotypic assays including migration, invasion, and colony-forming abilities were carried out in CSCs of two types of oral cancer cells (SAS and GNM) following the knockdown of LINC01296. In addition, the percentage of cells expressing stemness marker, ALDH1, and drug resistance marker, ABCG2, was examined as well as the self-renewal capacity after silencing of LINC01296. Moreover, a luciferase reporter was used to validate the direct interaction between LINC01296 and miR-143. Results: Our results showed that LINC01296 was significantly overexpressed in oral cancer tissues and positively correlated with stemness markers. The phenotypic and flow cytometry assays demonstrated that suppression of LINC01296 reduced the aggressiveness, cancer stemness features, and colony-forming and self-renewal abilities in oral CSCs. Furthermore, we demonstrated that LINC01296 may enhance cancer stemness features through suppression of the effect of miR-143. Conclusion: Silencing of LINC01296 may be a promising direction for oral cancer therapy by reducing cancer stemness via regulation of miR-143.

Uniportal Endoscopic Interlaminar Decompression in Lumbar Spinal Stenosis: A Comprehensive Review.

BACKGROUND: From the 1990s, there has been growth in the literature demonstrating the feasibility of minimally invasive approaches for treating variety lumbar spinal disorders. There is still much work to be done in overcoming the technical challenges and explicate relative advantages of endoscopic techniques in lumbar spine surgery. In this comprehensive literature review, we discuss the history, indications, contraindications, surgical techniques, learning curves, technical tips, adverse events, and examine peer-reviewed studies addressing uniportal endoscopic interlaminar decompression in lumbar spinal surgery. METHODS: This literature review was conducted with keywords "endoscopic," "minimally invasive," "uniportal endoscopic decompression," "interlaminar decompression," and "lumbar spinal surgery" using PubMed, Embase, ClinicalKey, and Google Scholar. RESULTS: Review of 423 patients who underwent uniportal endoscopic interlaminar lumbar decompression showed satisfying results with 82% of patients no longer having leg pain, and 13% of patients having only occasional pain, with no significant operation-related deterioration in leg or back pain. To compare the outcomes between endoscopic and microscopic technique, a comparative review of 192 lumbar lateral recess stenosis patients demonstrated the uniportal endoscopic group had 29% shorter operation duration, 1.2% fewer perioperative complications, and significantly reduced postoperative pain (visual analog scale) over 5 days, and reduced use of pain medications. Multiple retrospective studies echoed the outcomes of endoscopic decompression surgery, showed shorter hospitalization time, lower mean dural expansion, lower increment of horizontal displacement measured, and less elevated levels of postoperative serum CPK (creatine phosphokinase) and CRP (c-reactive protein). Lastly, a systematic review and meta-analysis that enrolled 994 patients found that patients who received the full-endoscopic decompression technique showed statistically lower levels of back pain and leg pain and a 40% lower chance of having complications compared with those receiving microscopic decompression in lumbar stenosis. CONCLUSIONS: Based on our literature review, there are multiple positive outcomes with endoscopic interlaminar lumbar decompression, which reduces operation duration, perioperative complications, and better postoperative outcomes. However, the technical challenge highlights the importance of further training and innovation in this rapidly evolving field.

Association between early treatment with Qingfei Paidu decoction and favorable clinical outcomes in patients with COVID-19: A retrospective multicenter cohort study.

The coronavirus disease 2019 (COVID-19) epidemic has been almost controlled in China under a series of policies, including "early diagnosis and early treatment". This study aimed to explore the association between early treatment with Qingfei Paidu decoction (QFPDD) and favorable clinical outcomes. In this retrospective multicenter study, we included 782 patients (males, 56 %; median age 46) with confirmed COVID-19 from 54 hospitals in nine provinces of China, who were divided into four groups according to the treatment initiation time from the first date of onset of symptoms to the date of starting treatment with QFPDD. The primary outcome was time to recovery; days of viral shedding, duration of hospital stay, and course of the disease were also analyzed. Compared with treatment initiated after 3 weeks, early treatment with QFPDD after less than 1 week, 1-2 weeks, or 2-3 weeks had a higher likelihood of recovery, with adjusted hazard ratio (HR) (95 % confidence interval [CI]) of 3.81 (2.65-5.48), 2.63 (1.86-3.73), and 1.92 (1.34-2.75), respectively. The median course of the disease decreased from 34 days to 24 days, 21 days, and 18 days when treatment was administered early by a week (P < 0.0001). Treatment within a week was related to a decrease by 1-4 days in the median duration of hospital stay compared with late treatment (P<0.0001). In conclusion, early treatment with QFPDD may serve as an effective strategy in controlling the epidemic, as early treatment with QFPDD was associated with favorable outcomes, including faster recovery, shorter time to viral shedding, and a shorter duration of hospital stay. However, further multicenter, prospective studies with a larger sample size should be conducted to confirm the benefits of early treatment with QFPDD.

Development of a Prognostic Signature Based on Single-Cell RNA Sequencing Data of Immune Cells in Intrahepatic Cholangiocarcinoma.

Analysis of single-cell RNA sequencing (scRNA-seq) data of immune cells from the tumor microenvironment (TME) may identify tumor progression biomarkers. This study was designed to investigate the prognostic value of differentially expressed genes (DEGs) in intrahepatic cholangiocarcinoma (ICC) using scRNA-seq. We downloaded the scRNA-seq data of 33,991 cell samples, including 17,090 ICC cell samples and 16,901 ICC adjacent tissue cell samples regarded as normal cells. scRNA-seq data were processed and classified into 20 clusters. The immune cell clusters were extracted and processed again in the same way, and each type of immune cells was divided into several subclusters. In total, 337 marker genes of macrophages and 427 marker genes of B cells were identified by comparing ICC subclusters with normal subclusters. Finally, 659 DEGs were obtained by merging B cell and macrophage marker genes. ICC sample clinical information and gene expression data were downloaded. A nine-prognosis-related-gene (PRG) signature was established by analyzing the correlation between DEGs and overall survival in ICC. The robustness and validity of the signature were verified. Functional enrichment analysis revealed that the nine PRGs were mainly involved in tumor immune mechanisms. In conclusion, we established a PRG signature based on scRNA-seq data from immune cells of patients with ICC. This PRG signature not only reflects the TME immune status but also provides new biomarkers for ICC prognosis.

[Characteristics of soil organic carbon and its fractions in subtropical evergreen broad-leaved forests along an urbanization gradient.] / åŸŽå¸‚åŒ–æ¢¯åº¦ä¸Šäºšçƒ­å¸¦å¸¸ç»¿é˜”å¶æž—åœŸå£¤æœ‰æœºç¢³åŠå ¶ç»„åˆ†ç‰¹å¾.

Subtropical evergreen broad-leaved forests were selected along an urban (Guangzhou) - suburban (Dinghushan) - rural (Huaiji) gradient in the Pearl River Delta, from which soil samples in different layers were collected. The changes in total organic carbon (TOC), recalcitrant organic carbon (ROC), and active organic carbon (AOC) including readily oxidizable organic carbon (ROOC), microbial biomass carbon (MBC), and water-soluble organic carbon (WSOC) of samples were examined along this urbanization gradient to reveal the influence of urbanization on forest soil organic carbon. Results showed that no significant differences in both TOC and ROC contents were observed in 0-5 cm soil layer along the gradient. In 5-60 cm soil layer, the TOC content was significantly higher in the rural forest than that in the suburban and urban forests, the ROC content was the highest in the suburban forest and no significant difference was observed between the urban and rural forests. The ROOC content was significantly lower in the suburban forest than in the rural (0-60 cm soil layer) and urban (0-10 cm soil layer) forests. The MBC content was significantly lower in the urban forest than that in the suburban and rural forests. The suburban forest had significantly lower WSOC than the urban forest (0-10 cm soil layer). In 0-20 cm layer, the percentage of AOC to TOC of the urban and rural forests was significantly higher than those of the suburban forest, while the percentage of ROC to TOC was the lowest in the rural forest. The significant difference in the percentage of ROC to TOC was only observed in 5-10 cm depth layer between the suburban and urban forests. The results indicated that urbanization increased the active components of soil organic carbon and reduced the stable ones, which could be detrimental to organic carbon accumulation in soils. The rural forest soils were more sensitive to the urbanization.

Delirium Associated With Fluoxetine Discontinuation: A Case Report.

BACKGROUND: Withdrawal symptoms on selective serotonin reuptake inhibitor (SSRI) discontinuation have raised clinical attention increasingly. However, delirium is rarely reported in the SSRI discontinuation syndrome. CASE: We report a case of delirium developing after fluoxetine discontinuation in a 65-year-old female patient with major depressive disorder. She experienced psychotic depression with limited response to treatment of fluoxetine 40 mg/d and quetiapine 100 mg/d for 3 months. After admission, we tapered fluoxetine gradually in 5 days because of its limited effect. However, delirious pictures developed 2 days after we stopped fluoxetine. Three days later, we added back fluoxetine 10 mg/d. Her delirious features gradually improved, and the clinical presentation turned into previous psychotic depression state. We gradually increased the medication to fluoxetine 60 mg/d and olanzapine 20 mg/d in the following 3 weeks. Her psychotic symptoms decreased, and there has been no delirious picture noted thereafter. CONCLUSIONS: Delirium associated with fluoxetine discontinuation is a much rarer complication in SSRI discontinuation syndrome. The symptoms of SSRI discontinuation syndrome may be attributable to a rapid decrease in serotonin availability. In general, the shorter the half-life of any medication, the greater the likelihood patients will experience discontinuation symptoms. Genetic vulnerability might be a potential factor to explain that SSRI discontinuation syndrome also occurred rapidly in people taking long-half-life fluoxetine. The genetic polymorphisms of both pharmacokinetic and pharmacodynamic pathways might be potentially associated with SSRI discontinuation syndrome.

Metals and possible sources of lead in aerosols at the Dinghushan nature reserve, southern China.

RATIONALE: Aerosols play an important role in depositing metals into forest ecosystems. Better understanding of forest aerosols with regard to their metal content and their possible sources is of great significance for air quality and forest health. METHODS: Particulate matter with an aerodynamic diameter less than 2.5 µm (PM(2.5)) in aerosols was collected every month for 20 months using moderate-volume samplers in the Dinghushan (DHS) nature reserve in southern China. The concentrations of metals (Al, Cd, Mn, Ni, Pb, and Zn) as well as the Pb isotopic ratios in the PM(2.5) samples were measured by inductively coupled plasma mass spectrometry (ICP-MS). RESULTS: Moderate pollution with aerosol PM(2.5) was detected at the DHS nature reserve with the air mass from mainland China being the predominant PM(2.5) source. The high enrichment factors (EFs) for the heavy metals Pb, Cd, and Zn, as well as the PM(2.5) mass concentrations, coupled with backward trajectory analysis, indicated the anthropogenic origins of the PM(2.5) and of the heavy metals in the PM(2.5). The Pb isotopic ratios revealed the contributions from various Pb sources, which varied between seasons. CONCLUSIONS: Industrial emissions and automobile exhaust from the Pearl River Delta (PRD) primarily contributed to the anthropogenic Pb in PM(2.5), although there was occasionally a contribution from coal combustion during the wet season. Pb isotopic ratios analyses are helpful for air quality assessment and Pb source tracing.

Quetiapine-associated leucopenia and thrombocytopenia: a case report.

BACKGROUND: There have been few reports regarding quetiapine-associated hematological effects other than white-blood-cell alteration. We present the first reported Han-Chinese case that developed leucopenia and thrombocytopenia after taking quetiapine. CASE PRESENTATION: We present a case of a person with a bipolar I disorder who experienced leucopenia and thrombocytopenia after taking 400 mg/day of quetiapine and 1000 mg/day of valproic acid for three and one-half months. The hematological toxicity abated upon the discontinuation of both drugs. However, due to the intolerable side effects of the replaced antipsychotic (haloperidol), and according to the patient's preference, we prescribed quetiapine and valproic acid again. There was a recurrence of leucopenia and a decreased platelet count by the sixth day. The adverse effects disappeared soon after we discontinued quetiapine, while keeping valproic acid treatment. CONCLUSION: Quetiapine-associated leucopenia and thrombocytopenia seems reversible but possibly fatal. Therefore, clinical practitioners should be aware of this adverse reaction.

Lipid-content-normalized polycyclic aromatic hydrocarbons (PAHs) in the xylem of conifers can indicate historical changes in regional airborne PAHs.

The temporal variation of polycyclic aromatic hydrocarbons (PAHs) concentrations as well as the lipid content in the xylem of Masson pine trees sampled from the same site were determined and compared with the days of haze occurrence and with the historical PAHs reported in sedimentary cores. The patterns of the lipid content as well as the PAH concentrations based on the xylem dry weight (PAHs-DW) decreased from the heartwood to the sapwood. The trajectories of PAHs normalized by xylem lipid content (PAHs-LC) coincided well with the number of haze-occurred days and were partly similar with the historical changes in airborne PAHs recorded in the sedimentary cores. The results indicated that PAHs-LC in the xylem of conifers might reliably reflect the historical changes in airborne PAHs at a regional scale. The species-specificity should be addressed in the utility and application of dendrochemical monitoring on historical and comparative studies of airborne PAHs.

[Expression of monocyte chemotactic protein-1 and its receptor in sudden coronary death].

OBJECTIVE: To investigate the expression of monocyte chemotactic protein-1 (MCP-1) and its receptor CC chemokine receptor-2 (CCR-2) in coronary atherosclerosis plaques between sidden coronary death (SCD) and non-SCD. Methods The expression levels of MCP-1 and CCR-2 in SCD group, coronary atherosclerosis group (non-SCD), control group (normal coronary artery) were detected by immunohistochemistry. RESULTS: Positive rates of MCP-1 among the three groups were 78%, 47%, and 0%, respectively, with significant expressing differences between each two groups (P<0.05). Positive rates of CCR-2 among three groups were 72%, 47%, and 0%, respectively, with significant expressing differences between the SCD group and coronary atherosclerosis group as well as between the SCD group and control group (P<0.05), but with no significant expressing difference between coronary atherosclerosis group and control group (P>0.05). CONCLUSION: Overexpression of MCP-1 and CCR-2 in coronary atherosclerotic plaques is closely correlated with SCD.

Absorption of hazardous pollutants by a medicinal fern Blechnum orientale L.

A Chinese medicinal fern Blechnum orientale (Linn) was separately collected from polluted and unpolluted sites to determine whether it could accumulate hazardous pollutants or not. Metal concentrations (Cu, Zn, Mn, Pb, Cd, Cr, As, and Hg) both in the fronds and roots and polycyclic aromatic hydrocarbons (PAHs) in the fronds of this fern were quantified. At both sites, roots of B. orientale had significantly higher heavy metals than the fronds. Concentrations of Pb, As, Hg, Cd, and Cu in the fronds at the polluted site were more than 2, 6, 7, 14, 5, and 13 times of those at the unpolluted site. Translocation factor and bioaccumulation factor implied that B. orientale did not have a good ability to transport heavy metals from the roots to the fronds. Total PAHs in the fronds at the polluted site were significantly higher than those at the unpolluted site, indicating the physiological PAHs absorption by B. orientale growing at polluted sites. Uptake of pollutants via stomata might be the main reason causing the significant accumulation of hazardous pollutants in the fronds of B. orientale. Large-scale systematical survey and intensive monitoring on pollutants in this medicinal fern should be necessarily strengthened.

Chemical constituents and pharmacologic actions of Cynomorium plants.

The stem of Cynomorium songaricum is a traditional Chinese medicine reputed to have tonic effects. C. coccineum growing in northern Africa and the Mediterranean region is regarded in Arabian medical practice as the "treasure of drugs". The major constituents of Cynomorium plants have been revealed to be phenolic compounds, steroids, triterpenes, etc. Pharmacologic studies showed that the Cynomorium plants had antioxidant, immunity-improving, anti-diabetic, neuroprotective, and other bioactivities. Some chemical constituents in Cynomorium plants are unstable, implying that the chemical components of the herbal medicines produced under different conditions may be variable. This review covers the literature published until December, 2011 and describes the pharmacologic effects and secondary metabolites of Cynomorium species.

A P2P Framework for Developing Bioinformatics Applications in Dynamic Cloud Environments.

Bioinformatics is advanced from in-house computing infrastructure to cloud computing for tackling the vast quantity of biological data. This advance enables large number of collaborative researches to share their works around the world. In view of that, retrieving biological data over the internet becomes more and more difficult because of the explosive growth and frequent changes. Various efforts have been made to address the problems of data discovery and delivery in the cloud framework, but most of them suffer the hindrance by a MapReduce master server to track all available data. In this paper, we propose an alternative approach, called PRKad, which exploits a Peer-to-Peer (P2P) model to achieve efficient data discovery and delivery. PRKad is a Kademlia-based implementation with Round-Trip-Time (RTT) as the associated key, and it locates data according to Distributed Hash Table (DHT) and XOR metric. The simulation results exhibit that our PRKad has the low link latency to retrieve data. As an interdisciplinary application of P2P computing for bioinformatics, PRKad also provides good scalability for servicing a greater number of users in dynamic cloud environments.

Physiological responses and accumulation of pollutants in woody species under in situ polluted condition in Southern China.

Physiological leaf traits and accumulation of pollutants of ten woody species in response to air pollution at seriously polluted site Sanguigang (SGG) and control site Maofengshan (MFS) in Southern China were studied. Net photosynthetic rates of most species at SGG were lower than those at MFS, but stomatal conductance (g(s)) showed opposite trend. The specific leaf area of Aporusa dioica, Sapium discolor, Schefflera octophylla and Toxicodendron succedaneum were significantly, 46.77, 13.09, 55.11 and 23.51 %, higher in SGG than in MFS, while chlorophyll content being the opposite. A. dioica had the highest sulphur (S) content at both sites (11.74 mg g(-1) at SGG and 11.07 mg g(-1) at MFS). Heavy metals concentrations were generally higher in species at SGG than at MFS. S. octophylla showed significantly higher concentrations of Zn, Cd and Mn (341.81, 2.41 and 2,287.29 µg g(-1)) than other species at SGG. Moreover, A. dioica had the highest Pb concentration (9.19 µg g(-1)), and L. glutinosa showed the highest Cr concentration (3.40 µg g(-1)). According to the integrated results, we infer that A. dioica, S. octophylla and L. glutinosa are the promising species for phytoremediation in the ceramic industry polluted environment.

[Characteristics of rain season atmospheric PM2.5 concentration and its water-soluble ions contents in forest parks along an urban-rural gradient in Guangzhou City of South China].

During the rainy season (April-September) of 2012, the atmospheric particulate matter with a diameter less than 2.5 mm (PM2.5) were sampled from the forest parks in the urban area, suburban area, and rural area of Guangzhou City. The mass concentration of PM2.5 and its water-soluble ions (SO4(2-), NO3-, NO2-, Cl-, F-, Na+, NH4+, Ca2+, K+, and Mg2+) contents were also measured. In the forest parks in the urban area, suburban area, and rural area, the diurnal variation of PM2.5 mass concentration was 21.8-161.7, 19.4-156.3, and 17.2-66.5 microg x m(-3), with an arithmetic average being 55.9, 49.8, and 44.4 microg x m(-3), respectively. SO4(2-), Na+, and NH4+ were the main components of water-soluble ions in the PM2.5, and the SO4(2-) had the highest content and decreased gradually from urban to rural forest parks. The contribution of the SO2 and NOx in the PM2.5 from coal combustion to the forest parks was larger than that from vehicle exhaust, but presented a decreasing trend from urban to rural forest parks, indicating that vehicle exhaust had a greater contribution to the atmospheric SO2 and NOx in the urban forest park. In the sampling period, the contribution of sea salt to the water soluble fractions (especially K+) of the PM2.5 was greater for the suburban forest park than for the other two parks. The equivalent concentration of the NH4+ in the PM2.5 was far less than those of the SO4(2-) and NO3-, with a neutralization ratio being much lower than 1.0, which suggested that the PM2.5 had a higher acidity. The PM2.5 acidity had an increasing trend from rural to urban forest parks.

[Analysis on oil fume particles in catering industry cooking emission].

By measuring the particulate matter of oil fume which is over 10 microm or below 10 microm separately and using microradiography and Electrical Low Pressure Impactor (ELPI), it is found out the distributing characteristic of oil fume particles in catering industry cooking emission. The result shows that the diameter of the oil fume particles which was sedimentated in the kitchen is between 10-400 microm, the concentration peak value is between 10-100 microm. The diameter of oil fume aerosol is mostly smaller than 1 microm, while the concentration peak value is between 0.063-0.109 microm. In addition, the mass concentration peak value is between 6.560-9.990 microm. Through the analysis to the physical characteristics of oil fume from catering industry cooking emissions, the eigenvalue of the oil fume has been found and the feature matter for monitoring the oil fume has been discovered to provide a reasonable standard for controlling and monitoring the catering industry cooking emission.

Analysis of polycyclic aromatic hydrocarbons in tree-rings of Masson pine (Pinus massoniana L.) from two industrial sites in the Pearl River Delta, south China.

Concentrations of polycyclic aromatic hydrocarbons (PAHs) were examined and potential sources of PAHs were identified from the dated tree-rings of Masson pine (Pinus massoniana L.) near two industrial sites (Danshuikeng, DSK and Xiqiaoshan, XQS) in the Pearl River Delta of south China. Total concentrations of PAHs (∑PAHs) were revealed with similar patterns of temporal trends in the tree-rings at both sites, suggesting tree-rings recorded the historical variation in atmospheric PAHs. The differences of individual PAHs and of ∑PAHs detected in the tree-rings between the two sites reflected the historical differences of airborne PAHs. Regional changes in industrial activities might contribute to the site-specific and period-specific patterns of the tree-ring PAHs. The diagnostic PAH ratios of Ant/(Ant + PA), FL/(FL + Pyr), and BaA/(BaA + Chr)) revealed that PAHs in the tree-rings at both sites mainly stemmed from the combustion process (pyrogenic sources). Principal component analysis further confirmed that wood burning, coal combustion, diesel, and gasoline-powered vehicular emissions were the dominant contributors of PAHs sources at DSK, while diesel combustion, gasoline and natural gas combustion, and incomplete coal combustion were responsible for the main origins of PAHs at XQS. Tree-ring analysis of PAHs was indicative of PAHs from a mixture of sources of combustion, thus minimizing the bias of short-term active air sampling.