Spectromicroscopy of Nanoscale Materials in the Tender X-Ray Regime Enabled by a High Efficient Multilayer-Based Grating Monochromator.

The combination of near edge X-ray absorption spectroscopy with nanoscale X-ray imaging is a powerful analytical tool for many applications in energy technologies, catalysis, which are critical to combat climate change, as well as microelectronics and life science. Materials from these scientific areas often contain key elements, such as Si, P, S, Y, Zr, Nb, and Mo as well as lanthanides, whose X-ray absorption edges lie in the so-called tender photon energy range 1.5-5.0 keV. Neither conventional grazing incidence grating nor crystal monochromators have high transmission in this energy range, thereby yielding the tender photon energy gap. To close this gap, a monochromator setup based on a multilayer coated blazed plane grating and plane mirror is devised. The measurements show that this novel concept improves the photon flux in the tender X-ray regime by two-orders-of-magnitude enabling previously unattainable laboratory and synchrotron-based studies. This setup is applied to perform nanoscale spectromicroscopy studies. The high photon flux provides sufficient sensitivity to obtain the electronic structure of Mo in platinum-free MoNi4 nanoparticles for electrochemical energy conversion. Additionally, it is shown that the chemical bonding of nano-structures in integrated circuits can be distinguished by the electronic configuration at the Si-K edge.

First Observation of New Flat Line Fano Profile via an X-Ray Planar Cavity.

A new Fano profile of a flat line is achieved experimentally by manipulating the relative amplitude of the continuum path, when q takes the pure imaginary number of -i in the x-ray regime. The underlying mechanism is that the interference term in the scattering will cancel the discrete term exactly. This new Fano profile renders only an observable continuum along with an invisible response to the discrete state of atomic resonance. The results suggest not only a different strategy to invisibility studies which provides a possible tool to identify weaker structures hidden by the strong white line, but also a new scenario to enrich the manipulations of two-path interference and nonlinear Fano resonance.

Risk factors for mortality within 6 mo in patients with diabetes undergoing urgent-start peritoneal dialysis: A multicenter retrospective cohort study.

BACKGROUND: The risk of early mortality of patients who start dialysis urgently is high; however, in patients with diabetes undergoing urgent-start peritoneal dialysis (USPD), the risk of, and risk factors for, early mortality are unknown. AIM: To identify risk factors for mortality during high-risk periods in patients with diabetes undergoing USPD. METHODS: This retrospective cohort study enrolled 568 patients with diabetes, aged ≥ 18 years, who underwent USPD at one of five Chinese centers between 2013 and 2019. We divided the follow-up period into two survival phases: The first 6 mo of USPD therapy and the months thereafter. We compared demographic and baseline clinical data of living and deceased patients during each period. Kaplan-Meier survival curves were generated for all-cause mortality according to the New York Heart Association (NYHA) classification. A multivariate Cox proportional hazard regression model was used to identify risk factors for mortality within the first 6 mo and after 6 mo of USPD. RESULTS: Forty-one patients died within the first 6 mo, accounting for the highest proportion of mortalities (26.62%) during the entire follow-up period. Cardiovascular disease was the leading cause of mortality within 6 mo (26.83%) and after 6 mo (31.86%). The risk of mortality not only within the first 6 mo but also after the first 6 mo was higher for patients with obvious baseline heart failure symptoms than for those with mild or no heart failure symptoms. Independent risk factors for mortality within the first 6 mo were advanced age [hazard ratio (HR: 1.908; 95%CI: 1.400-2.600; P < 0.001), lower baseline serum creatinine level (HR: 0.727; 95%CI: 0.614-0.860; P < 0.001), higher baseline serum phosphorus level (HR: 3.162; 95%CI: 1.848-5.409; P < 0.001), and baseline NYHA class III-IV (HR: 2.148; 95%CI: 1.063-4.340; P = 0.033). Independent risk factors for mortality after 6 mo were advanced age (HR: 1.246; 95%CI: 1.033-1.504; P = 0.022) and baseline NYHA class III-IV (HR: 2.015; 95%CI: 1.298-3.130; P = 0.002). CONCLUSION: To reduce the risk of mortality within the first 6 mo of USPD in patients with diabetes, controlling the serum phosphorus level and improving cardiac function are recommended.

SV-VATS exhibits dual intraoperative and postoperative advantages.

BACKGROUND: The merits of spontaneous ventilation video-assisted thoracic surgery (SV-VATS) are still controversial. Our team retrospectively evaluated the intraoperative and postoperative advantages of this surgical approach, comparing with mechanical ventilation video-assisted thoracic surgery (MV-VATS). METHODS: We did a single center retrospective study at the First Affiliated Hospital of Yunnan Province. 244 patients were eventually assigned to the SV-group and MV-group, and their intraoperative indicators and thoracic surgery postoperative data were included in the comparison. RESULTS: The SV-group exhibited markedly less intraoperative bleeding and postoperative thoracic drainage, and the bleeding volume was correlated with the volume and duration of drainage. Further analysis showed that, patients undergoing SV-VATS had less activation of white blood cells and neutrophils after surgery, but they also had lower serum albumin concentrations. Risks of short-term postoperative complications, including inflammatory reactions, malignant arrhythmias, constipation, and moderate or more pleural effusions, were also significantly reduced in the SV-group. Additionally, hospitalization cost was lower in the SV-group than that in the MV-group. CONCLUSIONS: SV-VATS is suitable for various types of thoracic surgery, and effectively reduce intraoperative bleeding and postoperative thoracic drainage. With less postoperative inflammatory response, it reduces the risk of short-term postoperative complications. It is also able to help to reduce the financial burden of patients.

Accurate diagnosis of endoscopic mucosal healing in ulcerative colitis using deep learning and machine learning.

BACKGROUND: In clinical applications, mucosal healing is a therapeutic goal in patients with ulcerative colitis (UC). Endoscopic remission is associated with lower rates of colectomy, relapse, hospitalization, and colorectal cancer. Differentiation of mucosal inflammatory status depends on the experience and subjective judgments of clinical physicians. We developed a computer-aided diagnostic system using deep learning and machine learning (DLML-CAD) to accurately diagnose mucosal healing in UC patients. METHODS: We selected 856 endoscopic colon images from 54 UC patients (643 images with endoscopic score 0-1 and 213 with score 2-3) from the endoscopic image database at Tri-Service General Hospital, Taiwan. Endoscopic grading using the Mayo endoscopic subscore (MES 0-3) was performed by two reviewers. A pretrained neural network extracted image features, which were used to train three different classifiers-deep neural network (DNN), support vector machine (SVM), and k-nearest neighbor (k-NN) network. RESULTS: DNN classified MES 0 to 1, representing mucosal healing, vs MES 2 to 3 images with 93.8% accuracy (sensitivity 84.6%, specificity 96.9%); SVM had 94.1% accuracy (sensitivity 89.2%, specificity 95.8%); and k-NN had 93.4% accuracy (sensitivity 86.2%, specificity 95.8%). Combined, ensemble learning achieved 94.5% accuracy (sensitivity 89.2%, specificity 96.3%). The system further differentiated between MES 0, representing complete mucosal healing, and MES 1 images with 89.1% accuracy (sensitivity 82.3%, specificity 92.2%). CONCLUSION: Our DLML-CAD diagnosis achieved 94.5% accuracy for endoscopic mucosal healing and 89.0% accuracy for complete mucosal healing. This system can provide clinical physicians with an accurate auxiliary diagnosis in treating UC.

Berberine-loaded M2 macrophage-derived exosomes for spinal cord injury therapy.

Spinal cord injury (SCI) causes immune activation of resident macrophages/microglia. Activated macrophages/microglia have two different phenotypes, the pro-inflammatory classically activated (M1) phenotype and the anti-inflammatory alternatively activated (M2) phenotype. M1 phenotype macrophages/microglia are the key factor in inflammation. The treatment of SCI remains a huge challenge due to the nontargeting and inefficiency of anti-inflammatory drugs through the blood-brain barrier (BBB). The purpose of this experiment was to design M2-type primary peritoneal macrophages exosomes (Exos) as a drug carrier for berberine (Ber), which can be efficiently targeted to deliver drugs to the injured spinal cord due to the natural advantage of Exos across the BBB. The Exos with particle size of 125±12 nm were loaded with by an ultrasonic method and the drug loading reached 17.13 ±1.64%. The Ber release experiment showed that the loaded sample (Exos-Ber) exhibited sustained release effect, and the cumulative release amount reached 71.44±2.86% within 48 h. In vitro and in vivo experiments confirmed that the Exos-Ber could decrease the M1 protein marker iNOS, elevate the M2 protein marker CD206 and reduce inflammatory and apoptotic cytokines (TNF-α, IL-1ß, IL-6, Caspase 9, Caspase 8), which showed that Exos-Ber had a good anti-inflammatory and anti-apoptotic effect by inducing macrophages/microglia from the M1 phenotype to M2 phenotype polarization. Moreover, the motor function of SCI mice was significantly improved after Exos-Ber treatment, indicating that Exos-Ber is a potential agent for SCI therapy. STATEMENT OF SIGNIFICANCE: Efficient targeting strategy for drug delivery. In addition to good biocompatibility and stealth ability, M2 macrophage-derived Exosomes present natural inflammatory targeting ability. The inflammatory microenvironment after spinal cord injury provides motivation for the targeting of exosomes. Natural drug carrier with higher safety. With the rapid development of nanomaterials, drug carriers have become more selective. However, due to the special microenvironment after central nervous system damage, some non-degradable inorganic materials will increase the pressure of self-healing and even secondary damage to neurons, which has been solved by the emergence of exosomes. Some previous studies used tumor cell line exosomes as drug carriers, but the carcinogenic factors carried by themselves have extremely high hidden dangers, and endogenous macrophage exosomes have absolute advantages over their safety.

Automated extraction of left atrial volumes from two-dimensional computer tomography images using a deep learning technique.

BACKGROUND: Precise segmentation of the left atrium (LA) in computed tomography (CT) images constitutes a crucial preparatory step for catheter ablation in atrial fibrillation (AF). We aim to apply deep convolutional neural networks (DCNNs) to automate the LA detection/segmentation procedure and create three-dimensional (3D) geometries. METHODS: Five hundred eighteen patients who underwent procedures for circumferential isolation of four pulmonary veins were enrolled. Cardiac CT images (from 97 patients) were used to construct the LA detection and segmentation models. These images were reviewed by the cardiologists such that images containing the LA were identified/segmented as the ground truth for model training. Two DCNNs which incorporated transfer learning with the architectures of ResNet50/U-Net were trained for image-based LA classification/segmentation. The LA geometry created by the deep learning model was correlated to the outcomes of AF ablation. RESULTS: The LA detection model achieved an overall 99.0% prediction accuracy, as well as a sensitivity of 99.3% and a specificity of 98.7%. Moreover, the LA segmentation model achieved an intersection over union of 91.42%. The estimated mean LA volume of all the 518 patients studied herein with the deep learning model was 123.3 ± 40.4 ml. The greatest area under the curve with a LA volume of 139 ml yielded a positive predictive value of 85.5% without detectable AF episodes over a period of one year following ablation. CONCLUSIONS: The deep learning provides an efficient and accurate way for automatic contouring and LA volume calculation based on the construction of the 3D LA geometry.

Diversity scaling of human vaginal microbial communities.

The composition and diversity of the human vaginal microbial community have been investigated intensively due to the diversity-stability relationship (DSR)-based hypothesis for bacterial vaginosis (BV) etiology, which was first proposed in the 1990s and has received renewed interest in recent years. Nevertheless, diversity changes (scaling) across individuals in a cohort or population have not yet been addressed, which is significant both theoretically and practically. Theoretically, biodiversity scaling is the core of biogeography, and practically, inter-subject heterogeneity is critical for understanding the etiology and epidemiology of human microbiome-associated diseases such as BV. Here we applied the diversity-area relationship (DAR), a recent extension to the classic species-area relationship (SAR), to study diversity scaling of the vaginal microbiome by reanalyzing reported data collected from 1 107 postpartum women. The model used here characterized the power-law (or its extension) relationships between accrued diversity and areas (numbers of individuals), upon which four biogeographic profiles were thus defined. Specifically, we established the DAR profile (relationship between diversity scaling parameter and so-termed diversity order (q)), similarly pair-wise diversity overlap (PDO) profile, maximal accrual diversity (MAD) profile, and ratio of individual-level to population-level diversity (RIP) profile. These four profiles offer valuable tools to assess and predict diversity scaling (changes) in the human vaginal microbiome across individuals, as well as to understand the dynamics of vaginal microbiomes in healthy women.

[Variation of O3 Concentration in Different Regions of Beijing from 2006-2015].

O3 continuous monitoring data for the Dingling, Guanyuan, Liulihe, and Qianmen sites from 2006-2015 were analyzed to investigate concentration levels, variation trends, temporal variations, and relationships with precursors and meteorological factors. The results showed that the ten year average concentrations of O3 at the Dingling site were the highest at 65.2 µg·m-3, followed by concentrations at Liulihe (53.4 µg·m-3), Guanyuan (49.6 µg·m-3) and Qianmen (40.4 µg·m-3). The O3 concentrations at Dingling showed a decreasing trend[0.5 µg·(m3·a)-1], while O3 concentrations at Guanyuan[0.9 µg·(m3·a)-1], Liulihe[0.3 µg·(m3·a)-1], and Qianmen[0.3 µg·(m3·a)-1] showed an increasing trend. The highest monthly average concentrations appeared during June and August, and the highest frequency occurred in July (17 times) with average concentrations of 99.8 µg·m-3. The lowest monthly average concentrations appeared during November and February, and the highest frequency occurred in January (14 times) with an average concentration of 16.6 µg·m-3. Notably, the time for the peak concentrations of O3 appeared earlier in the day in recent years. The peak concentrations of O3 appeared at 15:00-16:00 during 2013-2015, which was 1-2 hours earlier than previous years. The heavy air pollution of O3 occurred on 11 days at the Dingling site in 2015, which was ten days more than in 2013, indicating O3 pollution in the downwind suburban regions of Beijing in summer became more and more serious. The concentrations of O3 and NO2 at Dingling showed a positive correlation, while the concentrations of O3 and NO2 at the other sites showed a negative correlation, indicating O3 formation in Dingling was sensitive to NO2 chemistry, while O3 formation at the other sites was sensitive to VOC chemistry. The concentrations of O3 showed a positive correlation with temperature and negative correlations with humidity and surface pressure. Temperature had the greatest influence on O3 concentration, followed by surface pressure and humidity. For cases when daily maximum temperature exceeded 30℃ and relative humidity was between 30% and 70%, the probability of the O3 daily maximum 8 h concentration exceeding 200 µg·m-3 was high, indicating the air quality level reached levels for light pollution and moderate pollution.

Association between COX2 -765G/C polymorphism and periodontitis in Chinese population: a meta-analysis.

BACKGROUND: Studies had attempted to clarify the relation between COX2 -765G/C gene polymorphisms and periodontitis risk, but there has been no definite consensus to date. A meta-analysis was performed to further explore the relationship of COX2 -765G/C polymorphism on periodontitis risk among Chinese population. METHODS: The databases of PubMed, Springer Link, Ovid, Chinese Wanfang Databases, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biology Medicine were searched up to January 2017. The overall result and subgroup analysis results were combined using fixed-effect or random-effect based on the heterogeneity. RESULTS: Finally, 7 case-control publications including 1399 periodontitis cases and 1663 controls were identified according to the inclusion criteria. In the total analyses, COX2 -765G/C polymorphism had nonsignificant association on periodontitis risk in all models. The subgroup analyses suggested a significantly increased risk of periodontitis in studies with population-based controls and a significantly decreased risk in studies with hospital-based controls. CONCLUSIONS: This meta-analysis indicated that COX2 -765G/C polymorphism had significantly affect on periodontitis risk among Chinese individuals, which should be confirmed by other ethnic groups.

Comparison of effects between artificial joint replacement and proximal femoral nail anti-rotation for treatment of unstable intertrochanteric femoral fracture in elderly patients / 中国组织工程研究

BACKGROUND: Both proximal femoral nail anti-rotation (PFNA) and joint replacement in treatment of intertrochanteric femoral fracture can guarantee early bed removal and reduce long-term bed complications, but there are still more controversies in the selection of indications for the two methods.OBJECTIVE: To observe the differences in clinical effects of artificial joint replacement and PFNA in treatment of unstable intertrochanteric femoral fracture in elderly. METHODS: Totally 56 patients with Evans-Jensen types III-V intertrochanteric femoral fracture aged older than 65 years were enrolled in this study. Follow-up was conducted for 12 months. 11 cases did not complete follow-up visit. Among the remaining 45 cases, 27 patients were treated with artificial joint replacement, and 18 patients were treated with PFNA. Operation time, intraoperative blood loss, and postoperative weight-bearing time were compared between the two groups. Postoperative hip function was compared using Harris score between both groups. Postoperative complications were evaluated by clinical and radiological manifestations in both groups within 1 year after surgery. RESULTS AND CONCLUSION: (1) Operation time and postoperative weight-bearing time were shorter in artificial joint replacement group than in the PFNA group (t=5.596, t=14.142, P < 0.05). (2) At postoperative 1, 3 and 6 months, Harris score was significantly higher in the artificial joint replacement group than in the PFNA group (t=8.301, t=10.017, t=8.593, P < 0.05). Harris score was similar between the two groups at postoperative 1 year (t=1.541, P > 0.05). (3) The total incidence of complications was 22% in artificial joint replacement group and 23% in PFNA group; there were no statistical differences between the two groups (χ2=0.180, P > 0.05). (4) For elderly patients with unstable intertrochanteric femoral fracture, artificial joint replacement and PFNA can obtain satisfactory effect. The operation time of artificial joint replacement is short, and early weight-bearing contributes to reducing long-term bed complications.

MicroRNA-122 Inhibits Lipid Droplet Formation and Hepatic Triglyceride Accumulation via Yin Yang 1.

BACKGROUND/AIMS: An increase in intracellular lipid droplet formation and hepatic triglyceride (TG) content usually results in nonalcoholic fatty liver disease. However, the mechanisms underlying the regulation of hepatic TG homeostasis remain unclear. METHODS: Oil red O staining and TG measurement were performed to determine the lipid content. miRNA expression was evaluated by quantitative PCR. A luciferase assay was performed to validate the regulation of Yin Yang 1 (YY1) by microRNA (miR)-122. The effects of miR-122 expression on YY1 and its mechanisms involving the farnesoid X receptor and small heterodimer partner (FXR-SHP) pathway were evaluated by quantitative PCR and Western blot analyses. RESULTS: miR-122 was downregulated in free fatty acid (FFA)-induced steatotic hepatocytes, and streptozotocin and high-fat diet (STZ-HFD) induced nonalcoholic steatohepatitis (NASH) in mice. Transfection of hepatocytes with miR-122 mimics before FFA induction inhibited lipid droplet formation and TG accumulation in vitro. These results were verified by overexpressing miR-122 in the livers of STZ-HFD-induced NASH mice. The 3'-untranslated region (3'UTR) of YY1 mRNA is predicted to contain an evolutionarily conserved miR-122 binding site. In silico searches, a luciferase reporter assay and quantitative PCR analysis confirmed that miR-122 directly bound to the YY1 3'UTR to negatively regulate YY1 mRNA in HepG2 and Huh7 cells. The (FXR-SHP) signaling axis, which is downstream of YY1, may play a key role in the mechanism of miR-122-regulated lipid homeostasis. YY1-FXR-SHP signaling, which is negatively regulated by FFA, was enhanced by miR-122 overexpression. This finding was also confirmed by overexpression of miR-122 in the livers of NASH mice. CONCLUSIONS: The present results indicate that miR-122 plays an important role in lipid (particularly TG) accumulation in the liver by reducing YY1 mRNA stability to upregulate FXR-SHP signaling.

The effects of pprI gene of Deinococcus radiodurans R1 on acute radiation injury of mice exposed to 60Co γ-ray radiation.

The role of the pprI gene from Deinococcus radiodurans R1 in therapy of acute radiation injury of a mammalian host was investigated. We injected a plasmid containing the pprI gene into the muscle of mice exposed to total 6Gy of 60Co γ-ray radiation. After injection, we used in vivo gene electroporation technology to transfer the pprI gene into the cell. We found the PprI protein was expressed significantly at 1 d after irradiation, but there was no expression of pprI gene 7 d post-irradiation. The expression of pprI gene evidently decreased the death rate of mice exposed to lethal dose radiation, significantly relieved effects on blood cells in the acute stage, shortened the persistence time of the decrease of lymphocytes, and decreased the apoptotic rates of spleen cells, thymocytes and bone marrow cells. The expression of Rad51 protein in the lungs, livers, and kidneys was significantly higher in the mice treated with the pprI plasmid after irradiation. However, there were no obvious differences for Rad52 protein expression. We conclude that the prokaryotic pprI gene of D. radiodurans R1 first was expressed in mammalian cells. The expressed prokaryotic PprI protein has distinct effects of the prevention and treatment on acute radiation injury of mammal. The effects of radio-resistance may relate to expression of Rad51 protein which is homologous with RecA from D. radiodurans.

[Exploring the Severe Haze in Beijing During December, 2015: Pollution Process and Emissions Variation].

Severe haze episodes shrouded Beijing and its surrounding regions again during December, 2015, causing major environmental and health problems. Beijing authorities had launched two red alerts for atmospheric heavy pollution in this period, adopted a series of emergency control measures to reduce the emissions from major pollution sources. To better understand the pollution process and emissions variation during these extreme pollution events, we performed a model-assisted analysis of the hourly observation data of PM2.5, and meteorological parameters combined with the emissions variation of pollution sources. The synthetic analysis indicated that: (1) Compared with the same period of last year, the emissions of atmospheric pollution sources decreased in December 2015. However, the emission levels of primary pollutants were still rather high, which were the main intrinsic causes for haze episodes, and the unfavorable diffusion conditions represented the important external factor. High source emissions and meteorological factors together led to this heavy air pollution process. (2) Emergency control measures taken by the red alert for heavy air pollution could decrease the pollutants emission by about 36% and the PM2.5 concentrations by 11% to 21%. Though the implementation of red alert could not reverse the evolution trend of heavier pollution, it indeed played an active role in mitigation of PM2.5 pollution aggravating. (3) Under the heavy pollution weather conditions, air pollutants continued to accumulate in the atmosphere, and the maximum effect by taking emergency measures occurred 48-72 hours after starting the implementation; therefore, the best time for executing emergency measures should be 36-48 hours before the rapid rise of PM2.5 concentration, which requires a more powerful demand on the accuracy of air quality forecast.

[Different Air Pollution Situations of O3 and PM2.5 During Summer in Beijing].

Two different pollution situations of O3 and PM2.5 during summer in Beijing were analyzed from theperspective of synoptic situations, meteorological elements, precursors, atmospheric oxidation, back-trajectories of air mass and chemical compositions of PM2.5. The results showed that the synoptic situations in the pollution situation that O3 reached middle level pollution and PM2.5 maintained low concentrations (O3high-PM2.5 low) could be characterized as northwest gas flow in 500 hPa height and high-pressure rear in the ground. Whereas the synoptic situations in the pollution situation that O3 and PM2.5 both reached middle level pollution (O3-PM2.5 high) could be characterized as westerly gas flow in 500 hPa height and low pressure in the ground. Compared with the O3high-PM2.5 low situation, meteorological elements in O3-PM2.5 high situation could be characterized as stronger southerly winds and higher relative humidity. In the O3-PM2.5 high situation, initial concentrations of O3 and PM2.5 were higher and diurnal variations of PM2.5 were more significant, nevertheless, the average concentrations of O3 were lower than those in the O3high-PM2.5 low situation, respectively. The analysis of precursors, atmospheric oxidation and chemical compositions of PM2.5 showed that the accumulation and hygroscopic growth of PM2.5 under unfavorable meteorological conditions as well as the regional transport caused by strong southerly winds might be the main factors leading to high PM2.5 concentrations in O3-PM2.5 high situation.

[Scavenging Effect of Rime and East Wind on PM2.5 Under Air Heavy Pollution in Beijing].

In order to study the scavenging effect of rime and east wind on the concentrations of PM2.5 in Beijing during the air heavy pollution, PM2.5 concentration data of some mountains and plains stations was used, together with meteorological data, wind profile data, aerosol extinction coefficient radar data collected during December 19 to 27, 2015, to analyze the clearance mechanisms of rime and east wind on PM2.5.The results showed that ①the removal of PM2.5 by rime was a different mechanism from that by the north wind and rainy weather, in the cooling conditions, the droplets touched the branches, wire for solid condensation, leading to formation of rime, and the concentration of PM2.5 decreased;②the east wind is a special kind of wind in Beijing area, when easterly wind decreased with height, a strong upward motion could be formed, and the PM2.5 was uplifted from the surface layer to the top, while with larger westerly wind in top, it was removed into downstream and cleaned; when east wind increased with height, a weak downward movement was easy to form, and when this sinking motion could not reach the ground, the surface layer of PM2.5 capacity became small, which was beneficial to increase the concentration of PM2.5;③the PM2.5scavenging ability of east wind depended on two points, one was the strength and development of upward movement of the height formed by the east wind, and the second was the initial height of uplifted motion formed by east wind, the lower the origin of the ascending motion height, the more obvious the removal of PM2.5;④after occurrence of east wind, along with the ascending motion to m·s-1 magnitude, the mixed layer height increased to 1200-1800 meters, and PM2.5 was uplifted to top layer and cleaned.

[Implementation results of emission standards of air pollutants for thermal power plants: a numerical simulation].

The emission inventory of air pollutants from the thermal power plants in the year of 2010 was set up. Based on the inventory, the air quality of the prediction scenarios by implementation of both 2003-version emission standard and the new emission standard were simulated using Models-3/CMAQ. The concentrations of NO2, SO2, and PM2.5, and the deposition of nitrogen and sulfur in the year of 2015 and 2020 were predicted to investigate the regional air quality improvement by the new emission standard. The results showed that the new emission standard could effectively improve the air quality in China. Compared with the implementation results of the 2003-version emission standard, by 2015 and 2020, the area with NO2 concentration higher than the emission standard would be reduced by 53.9% and 55.2%, the area with SO2 concentration higher than the emission standard would be reduced by 40.0%, the area with nitrogen deposition higher than 1.0 t x km(-2) would be reduced by 75.4% and 77.9%, and the area with sulfur deposition higher than 1.6 t x km(-2) would be reduced by 37.1% and 34.3%, respectively.

Correction method for the self-absorption effects in fluorescence extended X-ray absorption fine structure on multilayer samples.

A novel correction method for self-absorption effects is proposed for extended X-ray absorption fine structure (EXAFS) detected in the fluorescence mode on multilayer samples. The effects of refraction and multiple reflection at the interfaces are fully considered in this correction method. The correction is performed in k-space before any further data analysis, and it can be applied to single-layer or multilayer samples with flat surfaces and without thickness limit when the model parameters for the samples are known. The validity of this method is verified by the fluorescence EXAFS data collected for a Cr/C multilayer sample measured at different experimental geometries.