Low-cost virtual instrumentation system of an energy-dispersive X-ray spectrometer for a scanning electron microscope

The paper describes an energy-dispersive X-ray spectrometer for a scanning electron microscope (SEM-EDXS). It was constructed using the new architecture of a virtual instrument (VI), which is low-cost, space-saving, fast and flexible way to develop the instrument. Computer-aided teaching (CAT) was used to develop the instrument and operation rather than a traditional instrument technique. The VI was designed using the object-oriented program language C++ and compact programmable logical devices (CPLD). These include spectra collection and processing, quantitative analysis and X-ray-intensity distribution analysis. The procedure is described in detail. The VI system gives an e¡ective and user-friendly human interface for the whole analytical task. Some examples are described

Screening of AAK1 interaction proteins and its role in regulating global translation level in cells

Objective·To investigate noval interacting partners for adaptor-associated protein kinase 1 (AAK1) and AAK1-mediated biological functions besides clathrin-mediated endocytosis.Methods·The labeled AAK1 vector and the blank control vector were transfected in HEK-293T cells, and the potential AAK1 interacting proteins were obtained by co-immunoprecipitation with agar-specific gel and mass spectrometry. Further verifications were performed by CoIP and fluorescence-based imaging. Recombinant proteins were purified in vitro and the direct interaction between proteins were confirmed by glutathione-S-transferase pulldown (GST Pulldown) assay. The regulation of AAK1 in the global protein synthesis was explored by puromycin incorporation assay.Results·Mass spectrometry results showed that AAK1 was associated with a series of proteins, including fragile X mental retardation syndrome-related protein 1 (FXR1), FXR2 and fragile X mental retardation protein 1 (FMRP). Enriching with anti-FLAG agarose gels after exogenous transfecting of AAK1-3xFLAG and FMRP-MYC plasmids, the expression of FMRP-MYC was detected. The expression of FMRP could also be detected by CoIP with endogenous AAK1 antibodies. Fluorescence-based imaging showed that they were spatially colocalized in the cytoplasm. GST Pulldown assay showed that FMRP could pulldown recombinant HIS6-AAK1 protein. Puromycin incorporation assay showed that in the same amount of time, the number of newly synthesized peptides labeled with puromycin was positively correlated with AAK1 protein expression.Conclusion·AAK1 directly interacts with FMRP in cytoplasm and could up-regulate global protein synthesis level

Past distribution of epiphyllous liverworts in China: The usability of historical data

Epiphyllous liverworts form a special group of bryophytes that primarily grow on the leaves of understory vascular plants in tropical and subtropical evergreen broadleaf forests. Being sensitive to moisture and temperature changes, epiphyllous liverworts are often considered to be good indicators of climate change and forest degradation. However, they are a poorly collected and taxonomically complicated group, with an only partly identified distribution pattern. In this study, we built four models based on 24 environmental variables at four different spatial resolutions (i.e., 1 km, 5 km, 10 km, and 15 km) to predict the past distribution of epiphyllous liverworts in China, using Maxent model and 63 historical location records (i.e., presence‐only data). Both area under the curve of the receiver operating characteristic (AUC) and true skill statistic (TSS) methods are used to assess the model performance. Results showed that the model with the predictors at a 15‐km resolution achieved the highest predictive accuracy (AUC=0.946; TSS=0.880), although there was no statistically significant difference between the four models (p > 0.05). The most significant environmental variables included aridity, annual precipitation, precipitation of wettest month, precipitation of wettest quarter, and precipitation of warmest quarter, annual mean NDVI, and minimum NDVI. The predicted suitable areas for epiphyllous liverworts were mainly located in the south of Yangtze River and seldom exceed 35°N, which were consistent with the museum and herbarium records, as well as the historical records in scientific literatures. Our study further demonstrated the value of historical data to ecological and evolutionary studies

Thermoelectric Transport in Nanocomposites.

Thermoelectric materials which can convert energies directly between heat and electricity are used for solid state cooling and power generation. There is a big challenge to improve the efficiency of energy conversion which can be characterized by the figure of merit

The heme-p53 interaction: Linking iron metabolism to p53 signaling and tumorigenesis

Recently, we reported that heme binds to tumor suppressor p53 protein (TP53, best known as p53) and promotes its nuclear export and cytosolic degradation, whereas iron chelation stabilizes p53 protein and suppresses tumors in a p53-dependent manner. This not only provides mechanistic insights into tumorigenesis associated with iron excess, but also helps guide the administration of chemotherapy based on iron deprivation in the clinic

Hydroxylamine Contributes More to Abiotic N2O Production in Soils Than Nitrite

Nitrite (NO2-) and hydroxylamine (NH2OH) are important intermediates of the nitrogen (N) cycle in soils. They play a crucial role in the loss of nitrous oxide (N2O) and nitric oxide (NO) from soil due to their high reactivity. In this study, we collected soil samples from three ecosystems (grassland, arable land, and forest with a riparian zone) and explored the contribution of NO2- and NH2OH to N2O formation in the different soils after exposure to oxic or anoxic pre-treatment. In addition, the importance of abiotic processes on the N2O formation from the two intermediates was studied by irradiating the soil samples with γ-irradiation. Our results demonstrate that NO2- addition induced the largest N2O production in the grassland soil, followed by the forest and arable soils. Only 9–39% of the produced N2O after NO2- addition came from abiotic processes. NH2OH addition increased N2O emissions the most from the arable soil, followed by the grassland and forest soils. The conversion of NH2OH to N2O was mostly (73–93%) abiotic. Anoxic pre-treatment decreased N2O production from NH2OH remarkably, especially for the grassland soil, while it increased N2O production from NO2- for most of the soils. Correlation analysis showed that NO2- effects on N2O production were strongly correlated to NH4+ content in soils with anoxic pre-treatment, while NH2OH effects on N2O production were strongly correlated to soil Mn and C content in soils with oxic pre-treatment. Our results indicate that NH2OH plays an important role for abiotic N2O formation in soils with low C and high Mn content, while the effect of NO2- was important mainly during biotic N2O production. Anoxic periods prior to N addition may increase the contribution of NO2-, but reduce the contribution of NH2OH, to soil N2O formation

The Effects of pH Change through Liming on Soil N2O Emissions

Nitrous oxide (N2O) is an overwhelming greenhouse gas and agricultural soils, particularly acidic soils, are the main source of its release to the atmosphere. To ameliorate acidic soil condition, liming materials are added as an amendment. However, the impact of liming materials has not been well addressed in terms of exploring the effect of soil pH change on N2O emissions. In the present study, a soil with pH 5.35 was amended with liming materials (CaMg(CO3)2, CaCO3, Ca(OH)2 and CaO) to investigate their effects on N2O emissions. The results indicate that application of liming materials reduced the magnitudes of N2O emissions. The maximum reduction of soil N2O emissions took place for Ca(OH)2 treatment when compared to the other liming materials, and was related to increasing soil pH. Mineral N, dissolved organic C, and microbial biomass C were also influenced by liming materials, but the trend was inconsistent to the soil pH change. The results suggest that N2O emission mitigation is more dependent on soil pH than C and N dynamics when comparing the different liming materials. Moreover, ameliorating soil acidity is a promising option to mitigate N2O emissions from acidic soilsThe authors would like to thank the funding bodies of the National Science Foundation of China (417501 10485), China Post-Doctoral Science Foundation (2017 M 622478), and National Key R&D Program (2017 YFD 0800102) for financially assisting the present researchS

Patterns of Carbon-Bound Exogenous Compounds Impact Disease Pathophysiology in Lung Cancer Subtypes in Different Ways.

Carbon-bound exogenous compounds, such as polycyclic aromatic hydrocarbons (PAHs), tobacco-specific nitrosamines, aromatic amines, and organohalogens, are known to affect both tumor characteristics and patient outcomes in lung squamous cell carcinoma (LUSC); however, the roles of these compounds in lung adenocarcinoma (LUAD) remain unclear. We analyzed 11 carbon-bound exogenous compounds in LUAD and LUSC samples using in situ high mass-resolution matrix-assisted laser desorption/ionization Fourier-transform ion cyclotron resonance mass spectrometry imaging and performed a cluster analysis to compare the patterns of carbon-bound exogenous compounds between these two lung cancer subtypes. Correlation analyses were conducted to investigate associations among exogenous compounds, endogenous metabolites, and clinical data, including patient survival outcomes and smoking behaviors. Additionally, we examined differences in exogenous compound patterns between normal and tumor tissues. Our analyses revealed that PAHs, aromatic amines, and organohalogens were more abundant in LUAD than in LUSC, whereas the tobacco-specific nitrosamine nicotine-derived nitrosamine ketone was more abundant in LUSC. Patients with LUAD and LUSC could be separated according to carbon-bound exogenous compound patterns detected in the tumor compartment. The same compounds had differential impacts on patient outcomes, depending on the cancer subtype. Correlation and network analyses indicated substantial differences between LUAD and LUSC metabolomes, associated with substantial differences in the patterns of the carbon-bound exogenous compounds. These data suggest that the contributions of these carcinogenic compounds to cancer biology may differ according to the cancer subtypes