PM2.5 elements at an urban site in Yangtze River Delta, China: High time-resolved measurement and the application in source apportionment.

Elemental concentrations of ambient aerosols are commonly sampled over 12-24 h, and the low time resolution puts a great limit on current understanding about the temporal variations and source apportionment based on receptor models. In this work, hourly-resolved concentrations of eighteen elements in PM2.5 at an urban site in Nanjing, a megacity in Yangtze River Delta of east China, were obtained by using a Xact 625 ambient metals monitor from 12/12/2016 to 12/31/2017. The influence of traffic activities was clearly reflected by the spikes of crustal elements (e.g., Fe, Ca, and Si) in the morning rush hour, and the firework burning and sandstorm events during the sampling periods were tracked by sharp enrichment of Ba, K and Fe, Ca, Si, Ti in PM2.5, respectively. To evaluate the advantage of hourly-resolved elements data in identifying impacts from specific emission sources, positive matrix factorization (PMF) analysis was performed with the 1-h data set (PMF1-h) and 23-h averaged data (PMF23-h), respectively. The 4- and 6-factor PMF23-h solutions had similar factor profiles and consistent factor contributions as the corresponding PMF1-h solutions. However, due to the limit in inter-sample variability, PMF analysis with 23-h average data misclassified some major (e.g., K, Fe, Zn, Ca, and Si) and trace (e.g., Pb) elements in factor profiles, resulting in different absolute factor contributions between PMF23-h and PMF1-h solutions. These results suggested the use of high time-resolved data to obtain valid and robust source apportionment results.

Myeloid Leukemia Factor Acts in a Chaperone Complex to Regulate Transcription Factor Stability and Gene Expression.

Mutations that affect myelodysplasia/myeloid leukemia factor (MLF) proteins are associated with leukemia and several other cancers. However, with no strong homology to other proteins of known function, the role of MLF proteins in the cell has remained elusive. Here, we describe a proteomics approach that identifies MLF as a member of a nuclear chaperone complex containing a DnaJ protein, BCL2-associated anthanogene 2, and Hsc70. This complex associates with chromatin and regulates the expression of target genes. The MLF complex is bound to sites of nucleosome depletion and sites containing active chromatin marks (e.g., H3K4me3 and H3K4me1). Hence, MLF binding is enriched at promoters and enhancers. Additionally, the MLF-chaperone complex functions to regulate transcription factor stability, including the RUNX transcription factor involved in hematopoiesis. Although Hsc70 and other co-chaperones have been shown to play a role in nuclear translocation of a variety of proteins including transcription factors, our findings suggest that MLF and the associated co-chaperones play a direct role in modulating gene transcription.

[Clinical Research of EGFR and KRAS Mutation in Fine Needle Aspiration Cytology Specimens of Non-small Cell Lung Carcinoma].

BACKGROUND: Epidermal growth factor receptor (EGFR) and KRAS must be detected mutation status before patients of lung cancer use targeted drugs. The aim of this study is to elucidate the significance of EGFR and KRAS mutation in fine needle aspiration (FNA) cytology suspension specimens of non-small cell lung carcinoma. METHODS: EGFR gene exons 18-21 and KRAS codons 12, 13 of exons 2 were performed by Real-time PCR methods in fine needle aspiration cytology suspension specimens of lymph nodes. RESULTS: 85 metastasis lymph nodes were detected in fine needle aspiration cytology samples of lung cancer. EGFR mutation rate was 37.3%. KRAS mutation rate was 7.2%. 19 formalin fixed paraffin-embedded tissue specimens were available and match cytology specimens. Analysis of EGFR mutation status in those samples revealed agreement with the results obtained in cytological samples (kappa=1.0). Clinical follow-up was available for 13 who presented with stage IV disease. Based on the identification of such mutations, these patients received subsequent therapy with a TKI in clinic. We observed two cases complete remission (16.7%) and 8 cases partial remission (66.7%) and three had ongoing stable disease. CONCLUSIONS: Fine-needle aspiration cytology samples were detected EGFR and KRAS mutation. The method which collects samples was easier, simple and convenient. This method has higher application value in clinical treatment.
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