Design and preparation of fluorescent covalent organic frameworks for biological sensing.

Covalent organic frameworks (COFs) are a new class of functional solids featuring several fantastic structural characteristics, including a great diversity of building units and cross-linking patterns, precise integration of building blocks, and adjustable topology of porous architecture. In addition to the above features, some COF samples are constructed with high-density conjugated fragments, which have unique potential advantages in fluorescence imaging, and thus may have great potential applications in bioimaging. Herein, this article summarizes the recent progress in the design and preparation of fluorescent covalent organic frameworks. We investigate the systemic correlation between the structural qualities of COF networks and biological sensors. Finally, the significant advantages, major challenges, and future opportunities of fluorescent covalent organic frameworks are discussed for the development of next-generation porous materials for sensing applications.

Peroxymonosulfate activation through ferromagnetic bimetallic spinel sulfide composite (Fe3O4/NiCo2S4) for organic pollutant degradation.

Spinel sulfides are a good candidate as heterogeneous catalysts for wastewater treatment through peroxymonosulfate (PMS) activation. In this paper, magnetic Fe3O4/NiCo2S4 composite was successfully synthesized by hydrothermal method. Catalyst screening displayed that the composite catalyst with a Fe3O4:NiCo2S4 molar ratio of 1:3 (i.e.,0.33-Fe3O4/NiCo2S4) is the most optimal. The results showed that 0.33-Fe3O4/NiCo2S4 composite catalyst had superior catalytic activity, achieving 99.8%,65.1% and 40.7% of RhB, COD and TOC removals within 30 min with 180 m g/L PMS and 75 mg/L catalyst. We proposed a potential catalytic mechanism of PMS activation by Fe3O4/NiCo2S4 in two aspects. On the one hand, sulfur species such as S2- and S22- enhance the Co3+/Co2+, Ni3+/Ni2+ and Fe3+/Fe2+ cycles on Fe3O4/NiCo2S4 surface. On the other hand, there is the synergistic effect of Co3+/Co2+, Ni3+/Ni2+ and Fe3+/Fe2+ cycles in activating PMS. Overall, owing to its excellent catalytic activity, reusability, and easy recovery, Fe3O4/NiCo2S4 is a potentially useful catalyst for remediation of contaminated water.

Impacts of Drought on Maize and Soybean Production in Northeast China During the Past Five Decades.

Climate change has a distinct impact on agriculture in China, particularly in the northeast, a key agriculture area sensitive to extreme hydroclimate events. Using monthly climate and agriculture data, the influence of drought on maize and soybean yields-two of the main crops in the region-in northeast China since 1961 to 2017 were investigated. The results showed that the temperature in the growing season increased by 1.0 °C from the period 1998-2017 to the period 1961-1980, while the annual precipitation decreased slightly. However, precipitation trends varied throughout the growing season (May-September), increasing slightly in May and June, but decreasing in July, August and September, associated with the weakening of the East Asian summer monsoon. Consequently, the annual and growing season drought frequency increased by 15%, and 25%, respectively, in the period 1998-2017 relative to the period 1961-1980. The highest drought frequency (55%) was observed in September. At the same time, the drought intensity during the growing season increased by 7.8%. The increasing frequency and intensity of drought had negative influences on the two crops. During moderate drought years in the period 1961-2017, 3.2% and 10.4% of the provincial maize and soybean yields were lost, respectively. However, during more severe drought years, losses doubled for soybean (21.8%), but increased more than four-fold for maize (14.0%). Moreover, in comparison to the period 1961-1980, a higher proportion of the yields were lost in the period 1998-2017, particularly for maize, which increased by 15% (increase for soybean was 2.4%). This change largely depends on increasing droughts in August and September, when both crops are in their filling stages. The impact of drought on maize and soybean production was different during different growth stages, where a strong relationship was noted between drought and yield loss of soybean in its filling stage. Given the sensitivity of maize and soybean yields in northeast China to drought, and the observed production trends, climate change will likely have significant negative impacts on productivity in the future.

The influence of excess precipitation on winter wheat under climate change in China from 1961 to 2017.

Winter wheat is one of China's most important staple food crops, and its growth and productivity are influenced by climate. Given its importance, we investigated the influence of excess precipitation under recent climate change on winter wheat in east-central China during 1961-2017. Although annual precipitation in the studied region decreased slightly, it increased during the winter wheat flowering and maturity period (May to June). Concurrently, the number of late growing season sunshine hours decreased. Our results showed that about 44% of the years with excess precipitation and less than normal radiation (16 years) were associated with decreasing winter wheat yields. Furthermore, during most years, precipitation of 50% above normal resulted in large decreases in winter wheat production in Jiangsu and Anhui provinces, some of the wetter parts of the studied region. These results indicated that the grain yield variability of winter wheat was mainly influenced by excess precipitation in May, where precipitation could explain 70%-78% of yield variability in the wet parts. Moreover, excess precipitation can induce Fusarium head blight as well as wheat sprouting of pre-harvest, both affecting the grain quality of winter wheat. Projected increases in precipitation throughout the 21st century in the studied region, warrants further studies of how to maintain the winter wheat production in a changing climate.

Clinical application of the Innovance D-dimer assay in the diagnosis of acute pulmonary thromboembolism.

Patients with acute pulmonary thromboembolism (APTE) have a high short-term mortality rate. The current study aimed to investigate the use of D-dimer in the diagnosis of APTE in suspected APTE patients. All suspected APTE patients were classified into diagnosis or control groups according to the results of a computed tomography pulmonary angiogram. Mann-Whitney U and Kruskal-Wallis H tests were used to evaluate the association between D-dimer values and APTE. Area under the curve (AUC) values and the Youden Index were used to determine D-dimer cut-off levels for the prediction of APTE. The data of 112 suspected APTE patients (54.8% women; mean age, 70.5 years) were analyzed prospectively. There were no significant differences in age (74.5 vs. 73.5 years, P=0.538) or gender distribution (female ratio 56.5 vs. 53.0%, P=0.847) between the diagnosis and control groups. The incidence of symptoms including dyspnea (67.4 vs. 33.3%; P<0.01), chest distress (47.8 vs. 25.8%; P<0.05) and elevated D-dimer (8.49 vs. 0.97 mg/l; P<0.001) were significantly higher in patients with APTE compared with the control group. D-dimer values >3.32 mg/l fibrinogen equivalent units (FEU) were indicative of APTE and the Youden Index was 0.69. The maximum AUC was 0.87 (95% CI: 0.79-0.92), the sensitivity and specificity were 89.13 and 80.30%, respectively, the positive and negative likelihood ratios were 4.53 and 0.14, respectively, and the positive and negative predictive values were 75.90 and 91.40%, respectively. A D-dimer value <0.60 mg/l FEU was the optimal threshold for excluding APTE diagnosis, with a sensitivity of 100.0% and a specificity of 28.79%. The positive and negative likelihood ratios were 1.40 and 0.00, respectively, and the positive and negative predictive values were 49.50 and 100.00%, respectively. Thus, D-dimer levels, combined with clinical assessment, yield high sensitivity and specificity in diagnosing APTE.

[Climatic suitability model for spring maize in Northeast China].

Crop growth is a continuous and dynamic process, and thus, the optimal meteorological indices for crop growth also change continuously. In this paper, the estimation algorithms of the daily available precipitation and the temporal interpolation methods of meteorological indices for crop growth were developed, and the climatic suitability model at daily scale was established, which was tested by the spring maize data of agro-meteorological stations in Northeast China. The simulated climatic suitability had significantly positive correlations with the height and 100-grain mass of spring maize. The correlation coefficient (R2) between the climatic suitability and the spring maize height was over 0.58 at vegetative growth stage, and over 0.45 at reproductive growth stage. The established climatic suitability model at daily scale could objectively reflect the interactions between crop growth and meteorological factors at vegetative growth stage and reproductive growth stage.

Proteomics-based generation and characterization of monoclonal antibodies against human liver mitochondrial proteins.

Monoclonal antibodies (mAbs) have the potential to be a very powerful tool in proteomics research to determine protein expression, quantification, localization and modification, as well as protein-protein interactions, especially when combined with microarray technology. Thus, a large amount of well-characterized and highly qualified antibodies are needed in proteomics. Purified antigen, which is not always available, has proven to be one of the rate-limiting steps in mAb large-scale generation. Here we describe our strategies to establish a murine hybridoma cell bank for human liver mitochondria using unknown native proteins as the immunogens. The antibody-recognized mitochondrial proteins were identified by MS following immunoprecipitation (IP), and by screening of human liver cDNA expression library. We found that the established antibodies reacted specifically with a number of important enzymes in mitochondria. The subcellular localization of these antigens in mitochondria was further confirmed by immunohistocytochemistry. A panel of antibodies was also tested for their ability to capture and deplete the targeting proteins and complexes from the total mitochondrial proteins. We believe these well-characterized antibodies would be useful in various applications for Human Liver Proteome Project (HLPP) when the scale of this hybridoma cell bank is enlarged significantly in the near future.

[Construction and primary analysis of subtractive library induced by soybean mosaic virus (SMV)].

SMV is one of main diseases of soybean, which could affect yields and quality of soybean seriously. It was effective to soybean breeding by studying the expression of resistant gene to SMV with molecular technology. In this study, a soybean resistance line, DongNong 8143, was used to construct a subtractive cDNA library by SSH from soybean leaves inoculated by SMV No.1 at primary stage. cDNA dominantly or specifically expressed in infected leaves was purified using PCR Purification Kit and cloned into pGEM-T easy vector. Colonies were grown on LB-agar plates containing ampicillin, X-gal and IPTG. A subtractive plasmid library was constructed by SSH. Then the library was transformed to host bacteria E. coli DH5alpha, and the titer of the library was measured as 2 x 10(3) . 64 clones were picked up randomly and sequenced. Of them there is 50 clones which result of sequenced were good. The length of EST fragment varied from 136bp to 691bp, and the average length is 456bp. Among them, 41 sequences has poly(A). Through ESTs were compared with sequences in unigene database of GeneBank with BLASTn and BLASTx algorithm, 38 ESTs of them had comparatively clear results and the percent of them in acquired ESTs is 74%. The EST expression profile showed that the resistance-related genes include cell protection, signal transduction, restrict pathogen growth, system acquired resistance, and house-keeping gene. There are 12 ESTs, which have not comparatively clear results, that maybe new genes.