The XRE Family Transcriptional Regulator SrtR in Streptococcus suis Is Involved in Oxidant Tolerance and Virulence

Streptococcus suis is a zoonotic pathogen that harbors anti-oxidative stress genes, which have been reported to be associated with virulence. Serial passage has been widely used to obtain phenotypic variant strains to investigate the functions of important genes. In the present study, S. suis serotype 9 strain DN13 was serially passaged in mice 30 times. The virulence of a single colony from passage 10 (SS9-P10) was found to increase by at least 140-fold as indicated by LD50 values, and the increased virulence was stable for single colonies from passage 20 (SS0-P20) and 30 (SS0-P30). Compared to the parental strain, the mouse-adapted strains were more tolerant to oxidative and high temperature stress. Genome-wide analysis of nucleotide variations found that reverse mutations occurred in seven genes, as indicated by BLAST analysis. Three of the reverse mutation genes or their homologs in other bacteria were reported to be virulence-associated, including ideSsuis in S. suis, a homolog of malR of Streptococcus pneumoniae, and a homolog of the prepilin peptidase-encoding gene in Legionella pneumophila. However, these genes were not involved in the stress response. Another gene, srtR (stress response transcriptional regulator), encoding an XRE family transcriptional regulator, which had an internal stop in the parental strain, was functionally restored in the adapted strains. Further analysis of DN13 and SS9-P10-background srtR-knock-out and complementing strains supported the contribution of this gene to stress tolerance in vitro and virulence in mice. srtR and its homologs are widely distributed in Gram-positive bacteria including several important human pathogens such as Enterococcus faecium and Clostridioides difficile, indicating similar functions in these bacteria. Taken together, our study identified the first member of the XRE family of transcriptional regulators that is involved in stress tolerance and virulence. It also provides insight into the mechanism of enhanced virulence after serial passage in experimental animals

Deep vein thrombosis and pulmonary embolism: a prospective, observational study to evaluate diagnostic performance of the Tina-quant D-Dimer Gen.2 assay

BackgroundD-Dimer testing is a diagnostic tool for exclusion of deep vein thrombosis (DVT) and pulmonary embolism (PE). This study evaluated the diagnostic performance of the Tina-quant® D-Dimer Gen.2 assay (Roche Diagnostics International Ltd, Rotkreuz, Switzerland) in patients with low/intermediate pre-test probability of DVT/PE using standard, age-, and clinical probability-adjusted cut-offs.MethodsIn this prospective, observational, multicenter study (July 2017–August 2019), plasma samples were collected from hospital emergency departments and specialist referral centers. DVT/PE was diagnosed under hospital standard procedures and imaging protocols. A standard D-dimer cut-off of 0.5 µg fibrinogen equivalent units (FEU)/ml was combined with the three-level Wells score; cut-offs adjusted for age (age × 0.01 µg FEU/ml for patients >50 years) and clinical probability (1 µg FEU/ml for low probability) were also evaluated. An assay comparison was conducted in a subset of samples using the Tina-quant D-Dimer Gen.2 assay and the previously established routine laboratory assay, STA-Liatest D-Di Plus assay (Stago Deutschland GmbH, Düsseldorf, Germany).Results2,897 patients were enrolled; 2,516 completed the study (DVT cohort: 1,741 PE cohort: 775). Clinical assessment plus D-dimer testing using the standard cut-off resulted in 317 (DVT) and 230 (PE) false positives, and zero (DVT) and one (PE) false negatives. Negative predictive value (NPV) was 100.0% (95% confidence interval [CI]: 99.7%–100.0%) and 99.8% (95% CI: 98.8%–100.0%) for DVT and PE, respectively. After age-adjustment, NPV was 99.9% (95% CI: 99.6%–100.0%) and 99.1% (95% CI: 97.8–99.7) for DVT and PE, respectively. False positive rates decreased (>50%) in clinical probability-adjusted analyses vs. primary analysis. In the assay comparison, the performances of the two assays were comparable.ConclusionThe Tina-quant D-Dimer Gen.2 assay and standard D-dimer cut-off level combined with the three-level Wells score accurately identified patients with a very low probability of DVT/PE

Cancer Biomarker Discovery: The Entropic Hallmark

Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases

A Comparative Study of Trade Relations and the Spatial-Temporal Evolution of Geo-Economy between China and Vietnam

With the increasing economic importance of the Asia-Pacific Region, the economic interdependence among countries in the region has gradually enhanced. With the continuous opening up of the two countries, Sino-Vietnamese economic relations have also been deepened. However, the export trade between Vietnam and China has been competitive. China and Vietnam seek to dominate or join an agreement that is conducive to their own trade, which also exacerbates the trade competition between the two countries. This paper compares China and Vietnam and analyzes their foreign trade data from 2005 to 2014. By analyzing the competitiveness of export commodities, the trade division effect and spatio-temporal changes of the geo-economic relationship in the Asia-Pacific Region, this study explores Sino-Vietnamese trade relations and compares the pattern of geo-economic evolution between the two countries. The findings show that China and Vietnam have similarities and substitutability in textiles, apparel and footwear in terms of commodity structure. There is already a trade diversion effect between Vietnam and China on these commodities, but it is not substantial. From a geographic perspective, China’s geo-economic relations in the Pacific Rim present an increasingly dispersed trend. However, the spatial pattern of Vietnam’s geo-economy has maintained a low-level and stable spatial agglomeration over the last decade

Influence of annealing on the stress-assisted two-way memory effect in cold-worked NiTi wire

The magnitude of stress‐assisted two‐way memory effect (SATWME) in NiTi alloys is affected by many factors and the mechanism of the development of SATWME is not been explored in depth. The influence of annealing on SATWME is investigated in a cold‐worked NiTi alloy by using a dynamic mechanical analyzer. Some new results are presented. NiTi shape memory alloys (SMAs) have attracted great attention in the past decades due to their novel performances, such as shape memory effect (SME),1-3 pseudoelasticity,4-6 and high damping.7, 8 These functional properties are related to the reversible martensitic transformation.9-12 As the research of SMA‐related applications expands in various industries, such as actuators, SMA pipe couplings, and SMA composites,1 the necessity for understanding and accurately predicting the SMA thermomechanical response grows faster. One typical issue is the stress‐assisted two‐way memory effect (SATWME) of NiTi alloys. The occurrence of SATWME has been characterized by the stress‐assisted martensitic transformation and the reverse transformation evoked during thermal cycling under a constant stress. The magnitude of SATWME is affected not only by pre‐strain, applied stress, and temperature but also by prior thermomechanical treatments, such as cold‐work and annealing. Wada and Liu13-15 have studied the shape recovery behavior of NiTi alloys under constant stresses and variable pre‐strain conditions. Bigeon and Morin16 investigated the influence of constant stress on the SATWME of TiNi alloy, and its maximum value appeared at about 200 MPa. Miller and Lagoudas3 also observed the occurrence of maximum SATWME in NiTi alloy at a similar constrained stress level provided that the alloy underwent certain cold‐work and heat treatment. However, the mechanism of the development of SATWME has not been explored in depth or fully understood. In order to provide more convincing experimental data, this study investigated the effect of annealing on the SATWME in cold‐worked NiTi wire. Such understanding is of significance to the application of these alloys. Some new results are presented in this paper.status: publishe

Influence of annealing time and thermo-mechanical cycling on constrained recovery properties of a cold-worked NiTi wire

In this work, the influence of parameters such as annealing time, pre-strain and thermo-mechanical cycling on recovery stresses of NiTi wires has been investigated by using a dynamic mechanical analyzer. The results show that the maximum recovery stress decreases with increasing annealing time and increases with increasing pre-strain except for 60-min annealed sample with 4% pre-strain, which has a higher recovery stress than 45-min annealed sample with the same pre-strain. The recovery stresses drastically increase during the first two thermo-mechanical cycles for all samples, regardless of annealing time. The observed changes of recovery stress could be attributed to different transformation temperatures and mechanical properties induced by different annealing times and/or thermo-mechanical cycling.status: publishe

Research on spatial characteristics of metropolis development using nighttime light data: NTL based spatial characteristics of Beijing.

As the capital and one of the metropolises in China, Beijing has met with a number of serious so-called "urban diseases" in the process of rapid urbanization such as blind expansion of urban areas, explosion of population and the increase of urban heat island effect. To treat these "urban diseases" and make the metropolis develop healthful and sustainable in Beijing in the future, the spatial characteristics of metropolis developments in Beijing are explored in this paper. The urban built-up areas in Beijing are extracted using the DMSP-OLS nighttime light data from 1992 to 2013. The characteristics of the urban developments of Beijing are studied, including spatial and temporal scales of urban developments, urban barycenter of Beijing and its transfer trajectory, variations of urban spatial forms and the differences of urban internal developments. The results have shown that the built-up areas had been increasing and circling extending from the central urban areas to the outer spaces in the last 21 years. The built-up area had expanded by 878km2 in 1992-2013, and the built-up area in 2013 had expanded to three times comparing to that of 1992. The expanding area of the built-up area in the northeast is the largest. The expansion of the urban had mainly occurred in 1996-2007, and the expanded area had accounted for 92% of the total research period. During the whole research period, the urban barycenter of Beijing had moved 5000.71 meters towards Northeast 28° of its original place from Dongcheng District to Chaoyang District. The development level of each municipal district had been increasing year by year, and the development differences among the municipal districts had been gradually reduced; the spatial forms of Beijing had been alternately changed between extensive and intensive expansion. The results of this study can help to plan urban land use and people migration of Beijing

Garden waste biomass for renewable and sustainable energy production in China: Potential, challenges and development

Garden waste biomass is a potentially underutilized renewable biofuel feedstock, which is increasing dramatically with rapid urbanization worldwide. China has experienced fast-paced urbanization over the past three decades: the settlement area has increased at a rate of 6.1% annually, with greenspace increasing by 12.7% annually from 1996 to 2008. This paper provides a synthesis of literature and experimental data to trace the potential of garden waste biomass for green renewable energy production in China. Our results show that the total potential biofuel produced by garden waste biomass was estimated at 260 petajoules (PJ), accounting for 20.7% of China's urban residential electricity consumption, or 12.6% of China's transport gasoline demand in 2008. Thus the use of garden waste biomass for energy production will contribute to the construction of low-carbon cities. However, there are still many difficulties the main challenges are how to quantify the available garden waste biomass accurately, and technical and financial issues with the exploitation of garden waste biomass for energy production. Finally, we provide several practical suggestions for the future development of garden waste biomass for energy production. The use of garden waste for energy production in urban areas could be a win-win approach for mitigating both the burden of disposed costs and the energy crisis. (C) 2013 Elsevier Ltd. All rights reserved.Garden waste biomass is a potentially underutilized renewable biofuel feedstock, which is increasing dramatically with rapid urbanization worldwide. China has experienced fast-paced urbanization over the past three decades: the settlement area has increased at a rate of 6.1% annually, with greenspace increasing by 12.7% annually from 1996 to 2008. This paper provides a synthesis of literature and experimental data to trace the potential of garden waste biomass for green renewable energy production in China. Our results show that the total potential biofuel produced by garden waste biomass was estimated at 260 petajoules (PJ), accounting for 20.7% of China's urban residential electricity consumption, or 12.6% of China's transport gasoline demand in 2008. Thus the use of garden waste biomass for energy production will contribute to the construction of low-carbon cities. However, there are still many difficulties the main challenges are how to quantify the available garden waste biomass accurately, and technical and financial issues with the exploitation of garden waste biomass for energy production. Finally, we provide several practical suggestions for the future development of garden waste biomass for energy production. The use of garden waste for energy production in urban areas could be a win-win approach for mitigating both the burden of disposed costs and the energy crisis. (C) 2013 Elsevier Ltd. All rights reserved

The Spatio-Temporal Evolution of Geo-Economic Relationships between China and ASEAN Countries: Competition or Cooperation?

In the last 30 years, China’s economic power has experienced great changes and has brought about a profound impact on the world economy. This led us to ask a question: do changes in China’s economic power shift the geo-economic relationships between China and its neighboring countries? To answer this question, we researched the evolution of geo-economic relationships between China and the Association of Southeast Asian Nations (ASEAN) countries. Using the Euclidean distance method, we explored the changes in these geo-economic relationships between China and ASEAN countries from 1980 to 2014. Our findings resulted in five conclusions: (1) Over time, geo-economic relationships between China and ASEAN countries remained relatively stable. (2) Geographically, the main geo-economic relationships between China and continental ASEAN countries were complementary, while the main geo-economic relationships between China and island ASEAN countries were competitive. (3) Geopolitics and geo-culture were attributed to the changes in geo-economic relationships. (4) The evolution of geo-economic relationships was characterized by path dependence. (5) Geo-economic relationships between China and ASEAN countries could be classified into four types: game type, with high cooperation and competition; complementary type, with high cooperation and low competition; fight type, with low cooperation and high competition; and loose type, with low cooperation and competition. Our findings contribute to improving the understanding of geo-economic relationships