quantitative-analysis-thermogravimetry-mass-spectrum-analysis-for

Quantitative Analysis by Thermogravimetry-Mass Spectrum Analysis for Reactions with Evolved Gases

During energy conversion, material production, and metallurgy processes, reactions often have the features of unsteadiness, multistep, and ...

Chinese Academy of Sciences

For the multianode-PMT-based quadrant tracking sensor, one of the tracking error sources is the crosstalk. The crosstalk can be reduced by de-crosstalk algorithm, so the tracking error of the de-crosstalk algorithm for the multianode-PMT-based quadrant tracking sensor are analyzed in theory and verified by experiments. Both the theoretical analysis and the experimental results showed that the spot displacement sensitivity could be improved by the de-crosstalk algorithm, but the spot centroid detecting error increased at the same time. So the de-crosstalk algorithm could not improve the tracking accuracy effectively.

Error analysis of the de-crosstalk algorithm for the multianode-PMT-based quadrant tracking sensor.

H9N2 influenza viruses with an A316S substitution in hemagglutinin (HA) and a shorter neuraminidase (NA) stalk have become predominant in China. The A316S was shown to increase HA cleavage efficiency when combined with short stalk NA, and the short stalk NA improved NA enzyme activity and release of virus from erythrocytes. Single mutations or combinations of these mutations strengthened the virulence of H9N2 virus in chickens and mice.

Amino acid 316 of hemagglutinin and the neuraminidase stalk length influence virulence of H9N2 influenza virus in chickens and mice.

Autophagy, a highly conserved process conferring cytoprotection against stress, contributes to the progression of cerebral ischemia. β-arrestins are multifunctional proteins that mediate receptor desensitization and serve as important signaling scaffolds involved in numerous physiopathological processes. Here, we show that both ARRB1 (arrestin, β 1) and ARRB2 (arrestin, β 2) were upregulated by cerebral ischemic stress. Knockout of Arrb1, but not Arrb2, aggravated the mortality, brain infarction, and neurological deficit in a mouse model of cerebral ischemia. Accordingly, Arrb1-deficient neurons exhibited enhanced cell injury upon oxygen-glucose deprivation (OGD), an in vitro model of ischemia. Deletion of Arrb1 did not affect the cerebral ischemia-induced inflammation, oxidative stress, and nicotinamide phosphoribosyltransferase upregulation, but markedly suppressed autophagy and induced neuronal apoptosis/necrosis in vivo and in vitro. Additionally, we found that ARRB1 interacted with BECN1/Beclin 1 and PIK3C3/Vps34, 2 major components of the BECN1 autophagic core complex, under the OGD condition but not normal conditions in neurons. Finally, deletion of Arrb1 impaired the interaction between BECN1 and PIK3C3, which is a critical event for autophagosome formation upon ischemic stress, and markedly reduced the kinase activity of PIK3C3. These findings reveal a neuroprotective role for ARRB1, in the context of cerebral ischemia, centered on the regulation of BECN1-dependent autophagosome formation. 

ARRB1/β-arrestin-1 mediates neuroprotection through coordination of BECN1-dependent autophagy in cerebral ischemia.

Archaea substantially contribute to global geochemical cycling and energy cycling and are impacted by land-use change. However, the response of archaeal communities to a change from upland field to paddy field has been poorly characterized. Here, soil samples were collected at two depths (0-20 cm and 20-40 cm) from one upland field and six paddy fields that were established on former upland fields at different times (1, 5, 10, 20, 30, and 40 years before the study). Barcoded pyrosequencing was employed to assess the archaeal communities from the samples at taxonomic resolutions from phylum to genus levels. The total archaeal operational taxonomic unit (OTU) richness showed a significant positive correlation with the land-use change duration. Two phyla, Euryarchaeota and Crenarchaeota, were recorded throughout the study. Both the relative abundance and OTU richness of Euryarchaeota increased at both depths but increased more steadily at the subsurface rather than at the surface. However, these data of Crenarchaeota were the opposite. Additionally, the archaeal composition exhibited a significant relationship with C/N ratios, total phosphorus, soil pH, Olsen phosphorus, and the land-use change duration at several taxonomic resolutions. Our results emphasize that after a change from upland fields to paddy fields, the archaeal diversity and composition changed, and the duration is an important factor in addition to the soil chemical properties. 

Duration-Related Variations in Archaeal Communities after a Change from Upland Fields to Paddy Fields.

A cascade radical cyclization of 2-isocyanoaryl thioethers with H-phosphorus oxides, organoboronic acids, or alkyl radical precursors has been efficiently developed, providing a novel and highly efficient methodology to structurally diverse C2-substituted benzothiazole derivatives with broad functional group tolerance and good yields. This cascade radical process achieves the first cycloaddition of an imidoyl radical from isocyanide to sulfur atom, rending C(sp)-S bond formation.

Cascade C(sp)-S Bond Cleavage and Imidoyl C-S Formation: Radical Cyclization of 2-Isocyanoaryl Thioethers toward 2-Substituted Benzothiazoles.

Soil organic C, N, P contents and their catalyzed enzyme activities play an important role in maintaining and supplying energy and nutrient in grasslands. There is no consensus on the effects of N deposition on soil organic nutrients and enzyme activities in grassland ecosystems. It remains unclear whether C addition will retard the negative effects of N deposition. We carried out an experiment in Hulun Buir grassland of Inner Mongolia to examine the effects of C and N additions on soil organic C, N, P and relative enzyme activities after three years treatments. The experiment was conducted with N treatments at five levels (0, 25, 50, 100 and 200 kg·hm·a) and with C treatments at three levels (0, 250 and 500 kg·hm·a). The results showed that higher levels of N addition significantly decreased dehydrogenase (DHA) and β-1,4-N-acetylglucosaminidase (NAG) activities by 22.3% and 12.5%, respectively. Nitrogen addition had no significant effect on soil organic N and decreased the organic C and P contents by 6.6% and 14.5%, respectively. High C addition significantly increased DHA, β-glucosidase (BG) activities and increased soil organic N and organic P by 15.1%, 12.2%, 1.9%, 2.6%, respectively. The results suggested that continuous N inputs inhibited microbial activities and caused losses of soil organic C and organic P. Carbon addition could enhance microbial activities and promote the secretion of enzymes and increase soil organic N and P. The combined C and N addition could play an important role in maintaining the balance and supply of soil C, N, and P in grassland ecosystem.

[Effects of carbon and nitrogen additions on soil organic C, N, P contents and their catalyzed enzyme activities in a grassland.]

There is much debate about whether the junction temperature or phosphor temperature is higher in white light-emitting diodes (LEDs). The main reason is that the junction and phosphor temperatures cannot be measured directly using traditional temperature measurement tools. In this study, a magnetic nanoparticle thermometer, a nondestructive and precise temperature measurement tool, is introduced and described in detail. The model, measurement principle, and experimental setup are described. The temperature of the phosphor layer and the top surface of the P-N junction in white LEDs was measured directly using the magnetic nanoparticle thermometer, and the results show that the phosphor layer temperature was higher than the chip top surface temperature at different input voltages, providing a reference for relative researchers.

The phosphor temperature measurement of white light-emitting diodes based on magnetic nanoparticle thermometer.

Studies on effects of nitrogen deposition were mainly focused on temperate grasslands in Inner Mongolia of China. In addition, there are substantial differences between the present simulation methods and the natural nitrogen deposition. A three-year experiment was carried out to compare the effects of simulation methods (common urea and slow-released urea) and nitrogen deposition rates (0, 25, 50, 75, 100, 150, 200 and 300 kg N·hm·a) on soil nutrients and biological characteristics in Hulun Buir Grassland. We found that simulated nitrogen deposition had significant influences on soil chemical properties, biological properties and enzyme activities. With the increases of nitrogen deposition, soil pH declined with the greatest extent of 0.2 units, while the highest concentrations of total dissolved nitrogen (TDN) and dissolved organic carbon (DOC) increased by 5-7 times and 12%-36%, respectively. There was a decline trend for soil total phosphorus (TP) and organic phosphorus (TOP). Microbial biomass and metabolic activity increased firstly and then decreased. Moderate simulated nitrogen deposition rates significantly increased soil carbon, nitrogen and phosphorus related enzyme activities. Compared to common urea, using slow-released urea to simulate nitrogen deposition decelerate the decline of soil pH and the increase of dissolved nutrients, and smoothed the change of microbial biomass, metabolic activity, and nitrogen hydrolyzed enzyme activities. Overall, the results confirmed that continuous nitrogen input caused the decline of soil pH and the increase of bioavailable carbon and nitrogen, and then changed microbial biomass and activity.

Kai Wei

Institute of Engineering Thermophysics

Chinese Academy of Sciences

Quantitative Analysis by Thermogravimetry-Mass Spectrum Analysis for Reactions with Evolved Gases