Integrated mRNA and microRNA profiling in lung tissue and blood from human silicosis.

BACKGROUND: The overwhelming majority of subjects in the current silicosis mRNA and microRNA (miRNA) expression profile are of human blood, lung cells or a rat model, which puts limits on the understanding of silicosis pathogenesis and therapy. To address the limitations, our investigation was focused on differentially expressed mRNA and miRNA profiles in lung tissue from silicosis patients to explore potential biomarker for early detection of silicosis. METHODS: A transcriptome study was conducted based on lung tissue from 15 silicosis patients and eight normal people, and blood samples from 404 silicosis patients and 177 normal people. Three early stage silicosis, five advanced silicosis and four normal lung tissues were randomly selected for microarray processing and analyze. The differentially expressed mRNAs were further used to conduct Gene Ontology and pathway analyses. Series test of cluster was performed to explore possible changes in differentially expressed mRNA and miRNA expression patterns during the process of silicosis. The blood samples and remaining lung tissues were used in a quantitative real-time PCR (RT-qPCR) (RT-qPCR). RESULTS: In total, 1417 and 241 differentially expressed mRNAs and miRNAs were identified between lung tissue from silicosis patients and normal people (p < 0.05). However, there was no significant difference in most mRNA or miRNA expression between early stage and advanced stage silicosis lung tissues. RT-qPCR validation results in lung tissues showed expression of four mRNAs (HIF1A, SOCS3, GNAI3 and PTEN) and seven miRNAs was significantly down-regulated compared to those of control group. Nevertheless, PTEN and GNAI3 expression was significantly up-regulated (p < 0.001) in blood samples. The bisulfite sequencing PCR demonstrated that PTEN had significantly decreased the methylation rate in blood samples of silicosis patients. CONCLUSIONS: PTEN might be a potential biomarker for silicosis as a result of low methylation in the blood.

Sirtuin-1 attenuates cadmium-induced renal cell senescence through p53 deacetylation.

Cadmium (Cd), the common environmental pollutant, primarily targets at renal proximal tubules and induces nephrotoxicity. Cellular senescence, a phenomenon of cell growth arrest and a characteristics of maladaptive cell self-repair, is associated with renal disease progression. However, whether and how Cd induces renal tubular cells premature senescence is unknown. In our study, we found that Cd induced kidney damage and dysfunctions, which correlated with exacerbated tubular cell senescence, evidenced by increased senescence-associated ß-galactosidase activity, the upregulated protein expression of p53 and p21Waf1/Cip1 proteins, and elevated expression and secretion of cytokines in human proximal tubular epithelial HK-2 cells in vitro and in Cd-treated mice in vivo. Moreover, a S-phase arrest and decrease in Edu positive rate were found in Cd-treated HK-2 cells. Mechanistically, Cd suppressed the expression and activity of Sirtuin-1 (SIRT1), an anti-senescence deacetylase, resulting in the accumulation of acetylated p53 and upregulation of p21Waf1/Cip1. Activation of SIRT1 significantly abolished Cd-induced premature senescence and S-phase arrest. Finally, silencing p21Waf1/Cip1 efficiently delayed premature senescence and recovered cell cycle progression. These findings indicate that Cd promotes tubular cells senescence and impairs tubular cells regeneration, resulting in kidney dysfunctions, which could be ameliorated by SIRT1 activation.

The effect of different drugs on hard metal lung disease in a rat model.

Hard metal lung disease (HMLD) drugs include dexamethasone sodium phosphate (Dex), methylprednisolone (MP) injection, N-acetylcysteine injection (NAC), and a mix of Dex, MP, and NAC (MIX). In this study, we compared the effects of these drugs on different cytokines of hard metal lung disease in a rat model. Thirty-six adult female Sprague Dawley rats were distributed equally into the control group, hard metal (HM) group, Dex group, MP group, NAC group, and MIX group. HM powder (0.5 mL, 20 mg/mL; one time) was administered by intraperitoneal injection to the HM group through the pulmonary endotracheal tube, while the control group received normal saline (0.5 mL, 20 mg/mL; one time). After 4 weeks, the drugs were administered to the experimental groups (0.5 mL, 20 mg/mL; one time). After 8 weeks, bronchoalveolar lavage fluid (BALF) and serum were examined for cytokine levels. Biochemical analysis indicated that the Dex, MP, NAC, and MIX did not improve TGF-ß1, TGF-ß2, KL-6, and MMP-1 in the BALF, while MIX increased TIMP-1 in BALF. In addition, the NAC treatment significantly increased the expression levels of TGF-ß1, TGF-ß2, KL-6, and MMP-1. The MIX treatment significantly increased the expression levels of TGF-ß1, TGF-ß2, and KL-6. The MP treatment significantly increased the expression levels of KL-6, and MMP-1. The Dex treatment significantly increased the expression levels of TGF-ß1, KL-6, and MMP-1. This study demonstrated that administered with NAC and MIX could improve TGF-ß1, TGF-ß2, and KL-6 in serum of hard metal lung disease in a rat model. Therefore, NAC injection may be considered a useful candidate in the development of a preventive agent against HMLD.

Efficacy of Beraprost Sodium Combined with Sildenafil and Its Effects on Vascular Endothelial Function and Inflammation in Patients Experiencing Left Heart Failure Complicated with Pulmonary Arterial Hypertension.

BACKGROUND To explore the efficacy of beraprost sodium combined with sildenafil and its effects on the vascular endothelial function and inflammation in left heart failure patients complicated with pulmonary arterial hypertension. MATERIAL AND METHODS A total of 80 patients with left heart failure complicated with pulmonary arterial hypertension was enrolled as the subjects of this study and assigned into an observation group (n=40) and a control group (n=40) using a random number table. The changes in pulmonary arterial hypertension-associated indicators at 3 months after treatment and the alterations in the levels of cardiac function-associated biochemical indicator brain natriuretic peptide (BNP), inflammatory factor tumor necrosis factor alpha (TNF-alpha), and mean pulmonary arterial pressure during treatment were compared between the 2 groups. RESULTS At 3 months after treatment, the pulmonary arterial hypertension-associated indicators human urotensin II and calcitonin gene-related peptide in the observation group were lower and higher, respectively, than those in control group. Moreover, the observation group had significantly lower BNP and TNF-alpha levels and mean pulmonary arterial pressure than the control group. After intervention, the echocardiographic parameters left ventricular ejection fraction (LVEF), cardiac output (CO), and stroke volume (SV) in both groups were significantly higher than those before intervention, and the observation group had significantly higher LVEF, SV, and CO than the control group after intervention. CONCLUSIONS Beraprost sodium combined with sildenafil for left heart failure complicated with pulmonary arterial hypertension can effectively improve pulmonary arterial hypertension, alleviate left heart failure, and reduce inflammatory responses, thereby achieving better clinical efficacy in patients.

Machine Learning Based Identification of Microseismic Signals Using Characteristic Parameters.

Microseismic monitoring system is one of the effective means to monitor ground stress in deep mines. The accuracy and speed of microseismic signal identification directly affect the stability analysis in rock engineering. At present, manual identification, which heavily relies on manual experience, is widely used to classify microseismic events and blasts in the mines. To realize intelligent and accurate identification of microseismic events and blasts, a microseismic signal identification system based on machine learning was established in this work. The discrimination of microseismic events and blasts was established based on the machine learning framework. The microseismic monitoring data was used to optimize the parameters and validate the classification methods. Subsequently, ten machine learning algorithms were used as the preliminary algorithms of the learning layer, including the Decision Tree, Random Forest, Logistic Regression, SVM, KNN, GBDT, Naive Bayes, Bagging, AdaBoost, and MLP. Then, training set and test set, accounting for 50% of each data set, were prospectively examined, and the ACC, PPV, SEN, NPV, SPE, FAR and ROC curves were used as evaluation indexes. Finally, the performances of these machine learning algorithms in microseismic signal identification were evaluated with cross-validation methods. The results showed that the Logistic Regression classifier had the best performance in parameter identification, and the accuracy of cross-validation can reach more than 0.95. Random Forest, Decision Tree, and Naive Bayes also performed well in this data set. There were some differences in the accuracy of different classifiers in the training set, test set, and all data sets. To improve the accuracy of signal identification, the database of microseismic events and blasts should be expanded, to avoid the inaccurate data distribution caused by the small training set. Artificial intelligence identification methods, including Random Forest, Logistic Regression, Decision Tree, Naive Bayes, and AdaBoost algorithms, were applied to signal identification of the microseismic monitoring system in mines, and the identification results were consistent with the actual situation. In this way, the confusion caused by manual classification between microseismic events and blasts based on the characteristics of waveform signals is solved, and the required source parameters are easily obtained, which can ensure the accuracy and timeliness of microseismic events and blasts identification.

A Waveform Image Method for Discriminating Micro-Seismic Events and Blasts in Underground Mines.

The discrimination of micro-seismic events (events) and blasts is significant for monitoring and analyzing micro-seismicity in underground mines. To eliminate the negative effects of conventional discrimination methods, a waveform image discriminant method was proposed. Principal component analysis (PCA) was applied to extract the raw features of events and blasts through their waveform images that established by the recorded field data, and transform them into the new uncorrelated features. The amount of initial information retained in the derived features could be determined quantitatively by the contribution rate. The binary classification models were established by utilizing the support vector machine (SVM) algorithm and the PCA derived waveform image features. Results of four groups of cross validation show that the optimal values for the accuracy of events and blasts, total accuracy, and quality evaluation parameter MCC are 97.1%, 93.8%, 93.60%, and 0.8723, respectively. Moreover, the computation efficiency per accuracy (CEA) was introduced to quantitatively evaluate the effects of contribution rate on classification accuracy and computation efficiency. The optimal contribution rate was determined to be 0.90. The waveform image discriminant method can automatically classify events and blasts in underground mines, ensuring the efficient establishment of high-quality micro-seismic databases and providing adequate data for the subsequent seismicity analysis.

Study of lung toxicity in rats exposed to silica powder with different hard metal constituents.

The objective of this study was to assess the lung toxicity induced by the inhalation of different hard metal constituents and silica powder and screen for potential toxicity biomarkers. Rats were randomly divided into saline, cobalt, tungsten carbide, silica, and hard metal (HM) groups and were administered a single 10-mg dose of the respective treatments. After 8 weeks, the lung tissue structure in the HM group was deformed, numerous nucleated giant and epithelial-like cells appeared in the stroma, and the computed tomography scanning images appeared abnormal. Krebs von den Lungen-6 (KL-6), transforming growth factor (TGF)-ß1, and TGF-ß2 expression in bronchoalveolar lavage fluid (BALF) significantly differed between the groups ( p < 0.05). Serum KL-6 and TGF-ß1, but not TGF-ß2, levels significantly differed between some groups ( p < 0.05). We observed multinucleated giant cells in the rat lung tissue. While the serum and BALF levels of KL-6 and TGF-ß2 are not highly specific, TGF-ß1 may be a valuable reference diagnostic marker in HM lung disease.

[Effects of indium chloride on proliferation of human lung epithelial cells and its mechanism].

OBJECTIVE: To investigate the effects of different concentrations of indium chloride (InCl3) on the proliferation of human lung epithelial (Beas-2B) cells and its potential mechanism. METHODS: Beas-2B cells were exposed to different concentrations of InCl3 (0.3, 1.0, 3.0, 10.0, 30.0, 90.0, 270.0, and 810.0 µmol/L) for 24, 48, and 72 h, respectively. The effects of InCl3 on cell proliferation were determined by the CCK-8 assay. The effects of InCl3 on apoptosis were evaluated using annexin V-PI staining followed by flow cytometry. The level of intracellular reactive oxygen species (ROS) in Beas-2B cells after exposure to InCl3 was determined using 2', 7'-dichlorofluorescein diacetate labeling followed by flow cytometry. RESULTS: Compared with the control group, InCl3 at a relatively low concentration (0.3~3.0 µmol/L) significantly promoted cell proliferation (P < 0.05), while InCl3 at a relatively high concentration (30.0~80.0 µmol/L) significantly inhibited cell proliferation after 72 h (P < 0.05). InCl3 at a concentration of 0.3 µmol/L failed to induce apoptosis within 72 h; however, InCl3 at a concentration of 30.0 or 810.0 µmol/L induced substantial early apoptosis after 72 h. Compared with the control group, cells exposed to 0.3 µmol/L InCl3 showed a slight decrease in the level of intracellular ROS within 72 h, while cells exposed to 30.0 or 810.0 µmol/L InCl3 showed a significant increase in the level of intracellular ROS after 72 h (P < 0.05). CONCLUSION: At a low concentration, InCl3 stimulates cell proliferation by reducing intracellular ROS. However, at a high concentration, InCl3 inhibits cell viability by elevating intracellular ROS and inducing apoptosis.

[The clinical features of indium-related lung diseases].

OBJECTIVE: To discuss the clinical features of Indium-related lung diseases. METHODS: We searched database of Chinese and Pubmed, Embase, Web of Science to collect research data of indium-related lung diseases from Jan. 1998 to Aprl. 2014. Case reports, exposure histories and lab results were analysed and summarized. RESULTS: 1998 to Mar 2010, ten cases of indium-related lung diseases were published. Seven cases of interstitial pneumonia were reported in Japan, two cases of pulmonary alveolar proteinosis (PAP) were reported in the USA and one case of PAP reported in China. Chest computer tomography (CT) showed diffuse or local ground glass appearance (GGA) in 8 cases, 3 of which also showed centrilobular nodules; Pulmonary function test were normal only in one out of 8 cases. Cholesterol clefts were found in 4 cases of interstitial pneumonia. 3 cases died among 6 cases who were followed-up. CONCLUSIONS: Occupational exposure to indium compounds are contributory to different pulmonary diseases, which are composed of interstitial pneumonia and pulmonary alveolar proteinosis. The relationships between In-C, In-S and these pulmonary diseases are unclear.

[Comparison of welder's pneumoconiosis with silicosis and follow-up study of welder's pneumoconiosis].

OBJECTIVE: To study the character of welder's pneumoconiosis on CT, pathology, and lung function. METHODS: To contrast 185 welder's pneumoconiosis and 115 silicosis on CT, pathology, and clinical characters which were diagnosed between Jan 2008 and Dec 2013. Chest X-ray and lung function of 39 welder's pneumoconiosis patients were followed up after diagnosed 4~6 years later. RESULTS: Average age and working years of welder's pneumoconiosis were 36.7 and 11.5, less than silicosis patients 58.8 and 22.1, respectively (P<0.05). Of all 185 welder's pneumoconiosis 98.4% were of stage I and no stage III, while in silicosis group stage I, stage II and stage III were 56.5%, 22.6% and 20.9%, respectively. The ratio differences between the two groups were statistically significant,P<0.05. 82.7% of welder's pneumoconiosis patients were observed pathologically moderate or above dust deposition in lung tissue while interstitial fibrosis level was just mild (97.6% patients) or no fibrosis (2.4% patients). By contrast, 60.0% silicosis patients pathologically showed moderate or above dust deposition while 77.8% were of moderate or above fibrosis. CT findings in welder' s pneumoconiosis were diffuse branching linear structure (38.9%), low density consistent size centrilobular micronodules (19.5%), or both (30.8%). Poorly-defined ground-glass attenuation centrilobular micronodules or widely ground glass shadow were observed in 6.4% welder's pneumoconiosis patents. 30.8% patients failed to reach the original stage when 39 welder's pneumoconiosis followed up chest radiograph. CONCLUSION: Changes in welder's lung caused by welding fume were not only siderosis, but also interstitial fibrosis.

The electronic properties of boron-doped germanium nanocrystals films.

Various doping concentrations of boron (B)-doped germanium nanocrystal (Ge NC) films were prepared using the plasma-enhanced chemical vapor deposition (PECVD) technique followed by thermal annealing treatment. The electronic properties of B-doped Ge NCs films combined with the microstructural characterization were investigated. It is worthwhile mentioning that the Hall mobilities [Formula: see text] of Ge NCs films were enhanced after B doping and reached to the maximum of 200 cm2 V-1, which could be ascribed to the reduction in surface defects states in the B-doped films. It is also important to highlight that the temperature-dependent mobilities [Formula: see text] exhibited different temperature dependence trends in the Ge NCs films before and after B doping. A comprehensive investigation was conducted to examine the distinct carrier transport properties in B-doped Ge NC films, and a detailed discussion was presented, focusing on the scattering mechanisms involved in the transport process.

Trajectories of Cognition and Daily Functioning Before and After Incident Diabetes.

OBJECTIVE: The temporal pattern of cognitive and functional change before and after incident diabetes remains unknown. RESEARCH DESIGN AND METHODS: Data from wave 2 to wave 9 (2004-2018) of the English Longitudinal Study of Ageing were used. Global cognition (assessed by orientation, memory, and executive function) and daily functioning (calculated as the sum of impaired basic and instrumental activities of daily living) were measured in each wave. Incident diabetes was defined as glycated hemoglobin A1c ≥6.5% (47.5 mmol/mol), self-reported doctor diagnosis of diabetes, or glucose-lowering medication use during follow-up. RESULTS: Among the 6,342 participants (mean age 65.0 years, 57.8% women) included, 576 participants (9.1%) with incident diabetes were identified during a median follow-up of 13.3 years. The annual rates of change in global cognition (ß = -0.035 SD/year; 95% CI -0.054 to -0.015), orientation (-0.031 SD/year; -0.060 to -0.002), memory (-0.016 SD/year; -0.029 to -0.003), and executive function (-0.027 SD/year; -0.042 to -0.013) were accelerated after diabetes diagnosis compared with before the event. The postdiabetes annual changes in daily functioning (0.093 points/year; 95% CI 0.056-0.131) were also accelerated compared with the prediabetes diagnosis. However, the rate of cognitive and functional decline before the diabetes diagnosis in participants with future incident diabetes was similar to the rate in participants without diabetes. Also, no significant acute change was observed during its onset. CONCLUSIONS: Incident diabetes is associated with accelerated cognitive and functional decline after, but not before, the event. We suggest careful monitoring for cognitive and physical dysfunction after a diabetes diagnosis.

Small-scale layered structures at the inner core boundary.

The fine-scale seismic features near the inner core boundary (ICB) provide critical insights into the thermal, chemical, and geodynamical interactions between liquid and solid cores, and may shed light on the evolution mechanism of the Earth's core. Here, we utilize a dataset of pre-critical PKiKP waveforms to constrain the fine structure at the ICB, considering the influence of various factors such as source complexity, structural anomalies in the mantle, and properties at the ICB. Our modeling suggests a sharp ICB beneath Mongolia and most of Northeast Asia, but a locally laminated ICB structure beneath Central Asia, Siberia, and part of Northeast Asia. The complex ICB structure might be explained by either the existence of a kilometer-scale thickness of mushy zone, or the localized coexistence of bcc and hcp iron phase at the ICB. We infer that there may be considerable lateral variations in the dendrites growing process at ICB, probably due to the complicated thermochemical and geodynamical interaction between the outer and inner core.

N-methyl-d-aspartate receptor 1 activation mediates cadmium-induced epithelial-mesenchymal transition in proximal tubular cells.

Cadmium (Cd) is a commonly found environmental pollutant and is known to damage multiple organs with kidneys being the most common one. N-methyl-d-aspartate receptor 1 (NMDAR1) is a ligand-gated ion channel that is highly permeable to calcium ion (Ca2+). Because Cd2+ and Ca2+ have structural and physicochemical similarities, whether and how Cd could interfere NMDAR1 function to cause renal epithelial cells dysfunction remains unknown. In this study, we investigated the role of NMDAR1 in Cd-induced renal damage and found that Cd treatment upregulated NMDAR1 expression and promoted epithelial-mesenchymal transition (EMT) in mouse kidneys in vivo and human proximal tubular epithelial HK-2 cells in vitro, which were accompanied with activation of the inositol-requiring enzyme 1 (IRE-1α) / spliced X box binding protein-1 (XBP-1s) pathway, an indicative of endoplasmic reticulum (ER) stress. Mechanistically, NMDAR1 upregulation by Cd promoted Ca2+ channel opening and Ca2+ influx, resulting in ER stress and subsequently EMT in HK-2 cells. Inhibition of NMDAR1 by pharmacological antagonist MK-801 significantly attenuated Cd-induced Ca2+ influx, ER stress, and EMT. Pretreatment with the IRE-1α/XBP-1s pathway inhibitor STF-083010 also restored the epithelial phenotype of Cd-treated HK-2 cells. Therefore, our findings suggest that NMDAR1 activation mediates Cd-induced EMT in proximal epithelial cells likely through the IRE-1α/XBP-1s pathway, supporting the idea that NMDAR1 could be a potential therapeutic target for Cd-induced renal damage.

[Pathology and neurophysiology analysis for peripheral neuropathy of four patients with chemicals poisoning].

OBJECTIVE: To study the nerve electromyogram results by analysing the pathological characters of 4 cases diagnosed as peripheral neuropathy caused by n-hexane and arsenic. METHODS: The nerve electromyogram examination and pathology data of 4 patients, who had been diagnosed as toxic chemicals peripheral neuropathy, were studied retrospectively. RESULTS: Two patients in this group were exposed to n-hexane, their nerve electromyogram examinations and biopsy pathology of superficial peroneal nerve indicated the peripheral neuropathy was mainly manifests the lesion of medullary sheath. Another two patients were exposed to arsenic, their nerve electromyogram examinations showed axonal degeneration associated with demyelination, and their biopsy pathology showed the peripheral neuropathy was mainly axonal degeneration. CONCLUSION: Axonal degeneration and demyelination always coexist in peripheral neuropathy caused by chemicals.

Slab control on the mega-sized North Pacific ultra-low velocity zone.

Ultra-low velocity zones (ULVZs) are localized small-scale patches with extreme physical properties at the core-mantle boundary that often gather at the margins of Large Low Velocity Provinces (LLVPs). Recent studies have discovered several mega-sized ULVZs with a lateral dimension of ~900 km. However, the detailed structures and physical properties of these ULVZs and their relationship to LLVP edges are not well constrained and their formation mechanisms are poorly understood. Here, we break the degeneracy between the size and velocity perturbation of a ULVZ using two orthogonal seismic ray paths, and thereby discover a mega-sized ULVZ at the northern edge of the Pacific LLVP. The ULVZ is almost double the size of a previously imaged ULVZ in this region, but with half of the shear velocity reduction. This mega-sized ULVZ has accumulated due to stable mantle flow converging at the LLVP edge driven by slab-debris in the lower mantle. Such flow also develops the subvertical north-tilting edge of the Pacific LLVP.

Association of baseline level of cardiovascular risk burden and its temporal changes with cognitive decline.

Background and aim: Previous studies on cardiovascular risk burden assessed by the Framingham General Cardiovascular Risk Score (FGCRS) and cognitive trajectories mainly focus on Western populations and most of them have used a single measure of cardiovascular risk. In this study, among middle-aged and older Chinese, we investigated (i) the association of baseline FGCRS with subsequent cognitive decline and (ii) the association of FGCRS change with concomitant cognitive decline. Materials and methods: In wave 1 to wave 4 (2011-2018) of the China Health and Retirement Longitudinal Study, global cognition was assessed by orientation, memory, and executive function. FGCRS was assessed and categorized into tertiles (low, intermediate, and high) at baseline (2011) and 4 years after (2015). Furthermore, external validation was performed to check its generalizability using the English Longitudinal Study of Ageing (ELSA) 2008-2018. Results: In total, 6,402 participants with a mean [standard deviation (SD) age of 57.8 (8.4) years, 49.0% women] with complete baseline data and at least one reassessment of cognitive function were included. A 10% increment in baseline FGCRS was associated with a faster decline in global cognition (-0.010 SD/year, 95% CI -0.013, -0.008). Among 4,336 participants [mean (SD) age of 57.8 (8.2) years, 50.0% women] with data on FGCRS changes, compared to individuals with the consistently low FGCRS (reference group), a faster global cognition decline rate was observed in the low to intermediate group (-0.026 SD/year, 95% CI -0.045, -0.007), the low to high group (-0.052 SD/year, 95% CI -0.102, -0.001), the consistently intermediate group (-0.019 SD/year, 95% CI -0.033, -0.005), the intermediate to high group (-0.040 SD/year, 95% CI -0.058, -0.022), the high to intermediate group (-0.024 SD/year, 95% CI -0.047, -0.002), and the consistently high group (-0.047 SD/year, 95% CI -0.060, -0.034). Similar trends were observed for individual cognitive domains. Results from the external validation using the ELSA remained consistent. Conclusion: Higher baseline FGCRS was associated with faster cognitive decline. However, there was no consistent relationship between the direction of changes in FGCRS and cognitive decline.

[Establishment of acute pulmonary edema model induced by high concentrations of nitrogen dioxide in rats].

OBJECTIVE: To establish the rats model of acute pulmonary edema induced by inhalation of high concentrations of nitrogen dioxide (NO2). METHODS: 38 SD rats were divided into the experimental group (n = 30) and the control group (n = 8). 30 rats in the experimental group were exposed to (6747.47 ± 25.24) mg/m(3) NO2 in the exposure system. At the time point of 6, 12, 18, 24 h, chest X-ray examination was taken for the experimental group. And at each time point, 6 rats were sacrificed after taking blood samples. After sacrificing, the lung of rats was taken for pathological examination and calculated lung wet/dry weight ratio. Erythrocyte superoxide dismutase (SOD) activity and plasma atrial natriuretic peptide (ANP) concentration of blood samples were detected. RESULTS: Acute pulmonary edema was successfully induced by exposure to NO2 in 30 rats within 24 hours. There were some cloudy shadows without clear edge on the chest X-ray. To the time point of 12 hours, shadows combined with each other, and to the time point of 18 hours, the whole lung became "white" on the X-ray. The situation stabilized but not improved at the time point of 24 hours. HE staining of the lung tissue showed that to the time point of 6 hours, the alveolar gap increased and small amount of eosinophilic liquid leaked into alveolar. To the time point of 12 hours, alveolar combined with each other and eosinophilic liquid increased in amount. To the time point of 18 hours, the whole alveolar was filled with eosinophilic liquid and the situation stabilized till the time point of 24 hours. Wet/dry weight ratio of the experimental group at each time point were 5.6 ± 0.20, 6.89 ± 0.25, 8.03 ± 0.47, 7.81 ± 0.45. There was significant difference compared with the control group which was 4.72 ± 0.06 (P < 0.01). There was statistical difference between 12, 18, 24 h and 6 h time points (P < 0.01). Moreover, statistical difference was observed between 18, 24 h and 12 h time points for wet/dry weight ratio (P < 0.01). The erythrocyte SOD activity reduced significantly. Compared with the control group, there was a statistical difference (P < 0.01) at each time point. After exposure of 18 and 24 hours, plasma ANP concentration (136.66 ± 35.37) and (134.10 ± 60.41) ng/ml respectively, which were higher than (31.31 ± 13.06) ng/ml of control group and (34.71 ± 13.42) ng/ml of 6 hours time point and (47.98 ± 7.86) ng/ml. The differences were significant (P < 0.01). CONCLUSION: High concentrations of NO2 can induce acute pulmonary edema model successfully in SD rats.

Structures, Electronic Properties and Carrier Transport Mechanisms of Si Nano-Crystalline Embedded in the Amorphous SiC Films with Various Si/C Ratios.

Recent investigations of fundamental electronic properties (especially the carrier transport mechanisms) of Si nanocrystal embedded in the amorphous SiC films are highly desired in order to further develop their applications in nano-electronic and optoelectronic devices. Here, Boron-doped Si nanocrystals embedded in the amorphous SiC films were prepared by thermal annealing of Boron-doped amorphous Si-rich SiC films with various Si/C ratios. Carrier transport properties in combination with microstructural characteristics were investigated via temperature dependence Hall effect measurements. It should be pointed out that Hall mobilities, carrier concentrations as well as conductivities in films were increased with Si/C ratio, which could be reached to the maximum of 7.2 cm2/V∙s, 4.6 × 1019 cm-3 and 87.5 S∙cm-1, respectively. Notably, different kinds of carrier transport behaviors, such as Mott variable-range hopping, multiple phonon hopping, percolation hopping and thermally activation conduction that play an important role in the transport process, were identified within different temperature ranges (10 K~400 K) in the films of different Si/C ratio. The changes from Mott variable-range hopping process to thermally activation conduction process with temperature were observed and discussed in detail.