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The stability of the power system is destroyed, will cause a large number of users power outage, even cause the collapse of the whole system, extremely serious consequences. Based on the analysis in single machine infinite system as an example, when at the f point two phase ground fault occurs, the fault lines on either side of the circuit breaker tripping resection at the same time,respectively by two kinds of calculation and simulation methods of system transient stability analysis, the conclusion are consistent. and the simulation analysis is superior to calculation analysis.

This study assesses the chemical characteristics of As in aerosol PM 2.5 samples that were collected from July 2011 to May 2012 in Beijing, China. Total As, As(Ⅲ), and As(Ⅴ) were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), high performance liquid chromatography (HPLC), and hydride generation atomic fluorescence (HG-AFS), respectively. The average concentrations of total As, As(Ⅲ) and As(Ⅴ) over the entire sampling period were (21.82±17.01), (3.15±1.94), and (10.78±5.39) ng·m -3 , respectively. The average concentrations of total As, As(Ⅲ) and As(Ⅴ) were (16.62±5.80), (18.34±9.00), (21.49±10.22), and (29.52±27.97) ng·m -3 during the spring, (5.42±2.5), (1.61±0.51), (2.88±1.12), and (3.27±1.23) ng·m -3 during the summer, and (7.55±1.47), (13.57±13.34), (12.75±6.54), and (8.68±3.57) ng·m -3 during the winter, respectively. The average concentrations of As(Ⅲ) in different seasons were higher than As(Ⅴ) concentrations. Seasonal characteristics may be caused by seasonal differences in diffusion conditions, emission sources, and atmospheric oxidation. The ratios of average concentrations of As(Ⅲ)/As(Ⅴ) were 0.67 in spring, 0.13 in summer, 0.27 in autumn, and 0.44 in winter. Ratios of As(Ⅲ)/As(Ⅴ) were negatively correlated with relative humidity, which indicates that high humidity conditions may not have been favorable for the transformation of As(Ⅲ) into As(Ⅴ). As(Ⅲ)/As(Ⅴ) and As(Ⅲ) both showed positive correlations with Ca 2+ , thereby indicating that soil dust may have been an important source of As(Ⅲ).

Samples of particulate matter from coal-fired boilers of different tons were collected in Lanzhou city, and the water-soluble inorganic ions, carbonaceous species, water-soluble organic compounds (WSOC) and polycyclic aromatic hydrocarbons (PAHs) were analyzed. The results showed that SO 4 2- , Cl - , and Ca 2+ were the most important water-soluble ions in the coal-fired boiler samples, accounting for 35.13%, 23.16%, and 22.20% of the total mass of water-soluble ions, respectively. The pyrolysis composition spectra of the carbonaceous species were similar among the coal-fired boilers, and organic carbon fraction (OC1, OC2, OC3, and OC4),and elemental carbon fraction (EC1, EC2, and EC3) accounted for 1.04%, 8.26%, 20.09%, 6.78%, 51.08%, 7.09%, and 5.66% of the total carbon (TC), respectively. EC1 had the highest content and was the most important carbonaceous species. The average ratios of WSOC/TC and WSOC/OC were 0.09±0.07 and 0.23±0.12, respectively, and the difference among the boilers of different tons was large. Phenanthrene (Phe), pyrene (Pyr), and benzene(k)anthracene (BkF) were the three main components of the PAHs, accounting for 16.69%, 11.93%, and 10.66% of the total PAHs, respectively. The particulate water-soluble ions, organic/elemental carbon aerosol (OCEC) and WSOC emitted from different tons coal-fired boilers were not significantly linearly related to the tonnage of the steam boiler, and low molecular weight PAHs decreased with the increase of tonnage of the steam boiler.

[This corrects the article on p. 10847 in vol. 8, PMID: 26617798.]., (IJCEP Copyright © 2018.)

MicroRNA-137 (miR-137) was reported to be dysregulated in several human cancers. However, the function and mechanism of miR-137 in non-small cell lung cancer (NSCLC) is still unclear. In the current study, we explored the role of miR-137 in NSCLC progression. Using qRT-PCR, our data showed that miR-137 was significantly down-regulated in NSCLC tissues and cell lines. In vitro functional assay, we found that over-expression of miR-137 suppressed NSCLC cells proliferation, migration and invasion, indicating that miR-137 could act as a tumor suppressor in NSCLC progression. In addition, bone morphogenetic protein-7 (BMP7) was identified as a target of miR-137 in NSCLC cells, Luciferase reporter assay suggested that miR-137 directly targeted 3'-UTR of BMP7, and correlation analysis revealed that BMP7 inversely correlated with miR-137 in NSCLC tissues. Furthermore, Restoration of BMP7 remarkably reversed the tumor suppressive effects of miR-137 on NSCLC cell proliferation, migration, and invasion. Taken together, our findings suggested that miR-137/BMP7 axis could contribute to the progression of NSCLC, suggesting miR-137 as a potential therapeutic target for the treatment of NSCLC.

In recent years, the food safety and quality has always been a serious issue. Therefore, it is urgent to develop a rapid and widely available method to determine the quality of food. Due to high spectral resolution, good spectral selectivity and good ability of spectrogram analysis, the technology of two-dimensional (2D) correlation spectroscopy is an effective method for solving three major problems encountered by the conventional one-dimensional (1D) spectrum: low selectivity of the spectra, difficulty in extracting the information of the spectral feature and difficulty in spectrogram analysis. Therefore, 2D correlation spectroscopy, which is suited to distinguish similar samples hardly distinguished by the conventional 1D spectroscopy, has been successfully applied in many complex biological systems. The developmental process, the experimental way to obtain spectrum, the fundamental mathematical principle and the properties of 2D correlation spectroscopy were introduced in this paper. At the same time, it is pointed out that the origin of weak characteristic bands of substance can be verified in terms of the positive or negative corss peaks in synchronous 2D correlation spectrum combined with the existence or inexistence of corss peaks in asynchronous 2D correlation spectrum. The application of 2D near-infrared, mid-infrared, fluorescence, and raman correlation spectroscopy in the detection of food quality and adulteration, concentrated specifically on diary product, wine, oil, meat, honey, and rice were reviewed. Finally, the limitations and future development prospects were pointed out.

Introduction: Non-small cell lung cancer (NSCLC) is the major cause of cancer death worldwide. Increasing evidence shows that long non coding RNAs (lncRNAs) are widely involved in the development and progression of NSCLC. lncRNA PVT1 in several cancers has been studied, its role in lung cancer remains unknown. Our studies were designed to investigate the expression, biological role and clinical significance of PVT1 in lung cancer., Methods: lncRNA PVT1 expression in 82 NSCLC tissues and 3 lung cancer cell lines was measured by quantitative Real-time PCR (qRT-PCR). Its association with overall survival of patients was analyzed by statistical analysis. RNA interference (RNAi) approaches were used to investigate the biological functions of PVT1. The effect of PVT1 on proliferation was evaluated by MTT, cell migration and invasion ability was evaluated by cell migration and invasion assays., Results: lncRNA PVT1 expression was significantly upregulated in NSCLC tissues and lung cancer cells when compared with corresponding adjacent normal tissues and normal bronchial epithelial cells. Increased PVT1 expression was significantly correlated with histological grade and lymph node metastasis. In addition, NSCLC patients with PVT1 higher expression have shown significantly poorer overall survival than those with lower PVT1 expression. And PVT1 expression was an independent prognostic marker of overall survival in a multivariate analysis. In vitro assays our results indicated that knockdown of PVT1 inhibited cell proliferation, migration, and invasion., Conclusions: Our data indicated that lncRNA PVT1 is significantly upregulated in NSCLC tissues and may represent a new biomarker and a potential therapeutic target for NSCLC intervention.

Based on Euclidian distances between synchronous two-dimensional infrared correlation spectra, in terms of the average Euclidian distances between unknown samples and "extreme samples", and average intra- and inter-Euclidian distances of samples in the calibration set, a new method for the discrimination of adulterated milk was proposed. Sixteen pure milk samples were collected and 16 adulterated milk samples with urea (0.01-0.3 g x L(-1)), and 16 adulterated milk samples with melamine (0.01-0.3 g x L(-1)) samples were prepared, respectively. The IR absorption spectra of all samples were measured at room temperature. The synchronous two-dimensional correlation spectra were generated from concentration-dependent spectral variation of adulterant in milk. The Euclidian distances were calculated between synchronous two-dimensional infrared correlation spectra of all samples. Then, the classification models were built respectively for adulterated milk with urea, and adiulterated milk with melamine. The "extreme samples", average intra- and inter-Euclidian distances were determined. Finally, the unknown samples in prediction set were predicted using constructed models in terms of classification rules of adulterated milk. The classification accuracy rates for pure milk and adulterated milk were 100%. The effectiveness of the proposed method was verified. The results obtained in this study revealed that synchronous two-dimensional infrared correlation spectra in combination with Euclidian distance has a feasible potential to discriminate adulterated milk and pure milk.

Objective: To investigate the clinical, pathological characteristics and outcomes of IgA nephropathy in the elderly., Methods: Seventy patients over age 60 with IgA nephropathy were studied and compared with 82 patients under 60 years in the clinical and pathological features as well as the outcomes., Results: Compared with non-elderly group, elder group patients had higher blood pressure [systolic pressure (142.0+/-20.4) mmHg vs (124.2+/-16.9) mmHg (1mmHg=0.133 kPa), diastolic pressure (83.1+/-11.8) mmHg vs (78.9+/-12.3) mmHg], serum creatinine [(172.7+/-125.8) micromol/L vs (94.4+/-42.5) micromol/L], serum cholesterol[(5.7+/-1.6) mmol/L vs (5.1+/-1.6) mmol/L], 24 hj urinary protein excretion rate [(3.4+/-2.9) g/d vs (1.8+/-2.0) g/d], and the incidence of CKD stages 3-5(64.0% vs 14.6%)(P<0.05). No significant differences were seen in the disease courses, rate of gross hematuria, serum triglyceride and serum IgA level between two groups(P>0.05).Renal pathological investigation showed the chronic lesions were dominated in elder group. There was significant difference in portion of glomerular sclerosis [(19.7+/-20.1)% vs (13.4+/-17.8)%], renal tubule atrophy (>1 score,34.2% vs 25.6%), interstitial fibrosis (>1,score 34.2% vs 18.2%), and arteriolosclerosis (>2 score,20.0% vs 8.5%) between two groups (P<0.05). However, there were no significant difference in proportion of mesangial proliferation, crescent and interstitial inflammatory cell infiltration (P>0.05). After a mean post-biopsy follow-up of (34.6+/-33.3) months, the 3-year and the 5-year renal survival rates for elder group were 74.6% and 62.2%, respectively, which were lower than those of non-elder group (100% and 92.9%, P=0.002)., Conclusion: Elder patients with IgA nephropathy were more likely to suffer from hypertension, hyperlipidemia, renal insufficiency and chronic pathologic lesions, which might be the risk factors for the patient's unfavorable prognosis.

Objective: To analyze the therapeutic results and prognostic factors of hepatic metastases treated by ultrasound-guided percutaneous microwave coagulation., Methods: Seventy-four patients with 149 nodules of hepatic metastases were given percutaneous microwave coagulation therapy. The longest diameter of the metastatic nodule ranged from 0.7 - 6.8 cm (mean, 3.1 +/- 1.8 cm). The cumulative survival rate was analyzed by Kaplan-Meier method and the difference between groups was compared with log-rank test. Cox proportional hazard model was used to determine potential prognostic variables., Results: The follow-up period for the 74 patients was 5 - 83 months (mean, 25.1 +/- 11.4 months). The overall 1-, 3-, and 5-year cumulative survival rates were 91.4%, 46.4% and 29.0%, respectively. The log-rank test showed that number of metastases, tumor size, tumor cell differentiation and local recurrence or new metastases were statistically significant prognostic factors; while age, sex and site of primary tumors were not significant prognostic factors. Multivariate analysis revealed that tumor differentiation, number of metastases and recurrence or new metastases were statistically significant prognostic factors., Conclusion: Ultrasound-guided percutaneous microwave coagulation therapy for hepatic metastases in patients with single metastasis, well-differentiated tumor, and without recurrence and new metastases could achieve long-term survival.