Relations between global forcing number and maximum anti-forcing number of a graph

The global forcing number of a graph G is the minimal cardinality of an edge subset discriminating all perfect matchings of G, denoted by gf(G). For any perfect matching M of G, the minimal cardinality of an edge subset S in E(G)-M such that G-S has a unique perfect matching is called the anti-forcing number of M,denoted by af(G, M). The maximum anti-forcing number of G among all perfect matchings is denoted by Af(G). It is known that the maximum anti-forcing number of a hexagonal system equals the famous Fries number. We are interested in some comparisons between the global forcing number and the maximum anti-forcing number of a graph. For a bipartite graph G, we show that gf(G)is larger than or equal to Af(G). Next we mainly extend such result to non-bipartite graphs, which is the set of all graphs with a perfect matching which contain no two disjoint odd cycles such that their deletion results in a subgraph with a perfect matching. For any such graph G, we also have gf(G) is larger than or equal to Af(G) by revealing further property of non-bipartite graphs with a unique perfect matching. As a consequence, this relation also holds for the graphs whose perfect matching polytopes consist of non-negative 1-regular vectors. In particular, for a brick G, de Carvalho, Lucchesi and Murty [4] showed that G satisfying the above condition if and only if G is solid, and if and only if its perfect matching polytope consists of non-negative 1-regular vectors. Finally, we obtain tight upper and lower bounds on gf(G)-Af(G). For a connected bipartite graph G with 2n vertices, we have that 0 \leq gf(G)-Af(G) \leq 1/2 (n-1)(n-2); For non-bipartite case, -1/2 (n^2-n-2) \leq gf(G)-Af(G) \leq (n-1)(n-2).Comment: 19 pages, 11 figure

Study on the molecular interactions of hydroxylated polycyclic aromatic hydrocarbons with catalase using multi-spectral methods combined with molecular docking.

To reveal the potential effects of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) on catalase (CAT), the interactions of 1-hydroxynaphthalene (1-OHNap), 9-hydroxyphenanthrene (9-OHPhe) and 1-hydroxypyrene (1-OHPyr) with CAT were investigated using multi-spectroscopic and molecular docking techniques. Fluorescence analysis showed that 1-OHNap, 9-OHPhe and 1-OHPyr can form 1:1 complex with CAT, with the binding constant of 6.31 × 103, 1.03 × 104 and 2.96 × 105 L mol-1 at 17 °C. Thermodynamic and docking parameters demonstrated that van der Waals’ force, hydrogen bonds and hydrophobic interactions dominated the three binding processes. Molecular docking also revealed the specific binding mode of OH-PAHs with CAT. Synchronous fluorescence and circular dichroism spectral results indicated that the three OH-PAHs induced varied structural changes of CAT. Furthermore, CAT activity was promoted by 9-OHPhe, but inhibited by either 1-OHNap or 1-OHPyr. Under the maximum experimental concentration of OH-PAHs, the percent change of CAT activity induced by 1-OHNap, 9-OHPhe and 1-OHPyr were 8.42%, 4.26% and 13.21%

Study on the molecular interactions of hydroxylated polycyclic aromatic hydrocarbons with catalase using multi-spectral methods combined with molecular docking

Abstract(#br)To reveal the potential effects of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) on catalase (CAT), the interactions of 1-hydroxynaphthalene (1-OHNap), 9-hydroxyphenanthrene (9-OHPhe) and 1-hydroxypyrene (1-OHPyr) with CAT were investigated using multi-spectroscopic and molecular docking techniques. Fluorescence analysis showed that 1-OHNap, 9-OHPhe and 1-OHPyr can form 1:1 complex with CAT, with the binding constant of 6.31 × 10 3 , 1.03 × 10 4 and 2.96 × 10 5 L mol −1 at 17 °C. Thermodynamic and docking parameters demonstrated that van der Waals’ force, hydrogen bonds and hydrophobic interactions dominated the three binding processes. Molecular docking also revealed the specific binding mode of OH-PAHs with CAT. Synchronous fluorescence and circular dichroism spectral results indicated that the three OH-PAHs induced varied structural changes of CAT. Furthermore, CAT activity was promoted by 9-OHPhe, but inhibited by either 1-OHNap or 1-OHPyr. Under the maximum experimental concentration of OH-PAHs, the percent change of CAT activity induced by 1-OHNap, 9-OHPhe and 1-OHPyr were 8.42%, 4.26% and 13.21%

Recent progress on RF orbital angular momentum antennas

In the last five years or so, there has been a great interest in RF OAM to address the contradiction between the lack of wireless spectrum resources and the continually growing demands of the bandwidth. Recent developments and technological advancements in antenna design, material science, and integrated circuits have enabled miniaturized, multiple modes, tunable in radio frequency (RF) orbital angular momentum (OAM) antenna designs. From conventional methods such as spiral phase plate and reflector antenna to antenna array and metasurface, the working principle and structures are introduced. To improve the performance of RF OAM antennas, several innovative physical concepts have been explored for the designs of RF OAM antenna designs. In this paper, we present an up-to-date survey on the development of RF OAM antenna technologies. Open issues and development trends are explored as a source of inspiration towards the future better outcome of RF OAM antenna designs

Neurodevelopmental toxicity assessments of alkyl phenanthrene and Dechlorane Plus co-exposure in zebrafish.

Alkyl phenanthrene (A-Phen) and Dechlorane Plus (DP) are ubiquitous environmental pollutants that widely co-exist in the environment. It has been established that both A-Phen and DP elicit neurotoxicity, but the potential interactive toxicity of these contaminants is not well-known. To determine whether a mixture of A-Phen and DP would exhibit interactive effects on neurodevelopment, we co-exposed 3-methylphenanthrene (3-MP), a representative of A-Phen, with DP. Our results illustrated that exposure to 5 or 20 μg/L 3-MP alone or in combination with 60 μg/L DP caused neurobehavioral anomalies in zebrafish. In accordance with the behavioral deficits, 3-MP alone or co-exposed with DP significantly decreased axonal growth of secondary motoneurons, altered intracellular Ca2+ homeostasis and induced cell apoptosis in the muscle of zebrafish. Additionally, 3-MP alone or co-exposed with DP significantly increased reactive oxygen species (ROS) and the mRNA levels of apoptosis-related genes. These findings indicate that 3-MP alone or co-exposed with DP induces neurobehavioral deficits through the combined effects on neuronal connectivity and muscle function. Chemical analysis revealed significant increases in 3-MP and DP bioaccumulation in zebrafish co-exposed with 3-MP and DP. Elevated bioaccumulation resulting from mixture exposure may represent a significant contribution of the synergistic effects observed in combined chemical exposure

Elevated Foxp3+ double-negative T cells are associated with disease progression during HIV infection

Persistent immune activation, which occurs during the whole course of HIV infection, plays a pivotal role in CD4+ T cells depletion and AIDS progression. Furthermore, immune activation is a key factor that leads to impaired immune reconstitution after long-term effective antiretroviral therapy (ART), and is even responsible for the increased risk of developing non-AIDS co-morbidities. Therefore, it’s imperative to identify an effective intervention targeting HIV-associated immune activation to improve disease management. Double negative T cells (DNT) were reported to provide immunosuppression during HIV infection, but the related mechanisms remained puzzled. Foxp3 endows Tregs with potent suppressive function to maintain immune homeostasis. However, whether DNT cells expressed Foxp3 and the accurate function of these cells urgently needed to be investigated. Here, we found that Foxp3+ DNT cells accumulated in untreated people living with HIV (PLWH) with CD4+ T cell count less than 200 cells/µl. Moreover, the frequency of Foxp3+ DNT cells was negatively correlated with CD4+ T cell count and CD4/CD8 ratio, and positively correlated with immune activation and systemic inflammation in PLWH. Of note, Foxp3+ DNT cells might exert suppressive regulation by increased expression of CD39, CD25, or vigorous proliferation (high levels of GITR and ki67) in ART-naive PLWH. Our study underlined the importance of Foxp3+ DNT cells in the HIV disease progression, and suggest that Foxp3+ DNT may be a potential target for clinical intervention for the control of immune activation during HIV infection

GSKJ4 Protects Mice Against Early Sepsis via Reducing Proinflammatory Factors and Up-Regulating MiR-146a

Sepsis, defined as life-threatening organ dysfunction, is one of the most common causes of mortality in intensive care units with limited therapeutic options. However, the mechanism underlying the regulation of epigenetics on sepsis remains largely undefined. Here we showed that JMJD3, the histone lysine demethylase, played a critical role in the epigenetic regulation of innate immunity during early sepsis. Pharmacological inhibition of JMJD3 by GSKJ4 protected mice against early septic death and reduced pro-inflammatory cytokine interleukin-1β (IL-1β) production as well as IL-6, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) expression. Interestingly, GSKJ4 up-regulated the transcription of anti-inflammatory microRNA-146a (miR-146a) in peritoneal macrophages from septic mice. Mechanistically, JMJD3 negatively regulated the transcription of miR-146a via its demethylation of H3K27me3 on the promoter of miR-146a. Moreover, the transcription of miR-146a was positively regulated by nuclear factor-κB (NF-κB) p65. Inhibition of NF-κB p65 promoted JMJD3 binding to miR-146a promoter and decreased the tri-methylation level of H3K27, while the inhibition of JMJD3 did not affect the recruitment of NF-κB p65 to miR-146a promoter. These results highlight an epigenetic mechanism by which JMJD3 was inhibited by NF-κB p65 from binding to miR-146a promoter to promote the anti-inflammatory response. Taken together, our findings uncover a key role for JMJD3 in modulating the miR-146a transcription and shed light on the JMJD3 inhibitors could be potential therapeutic agents for early sepsis therapy

Population response of intestinal microbiota to acute Vibrio alginolyticus infection in half-smooth tongue sole (Cynoglossus semilaevis)

IntroductionVibriosis causes enormous economic losses of marine fish. The present study investigated the intestinal microbial response to acute infection of half-smooth tongue sole with different-dose Vibrio alginolyticus within 72 h by metagenomic sequencing.MethodsThe inoculation amount of V. alginolyticus for the control, low-dose, moderate-dose, and high-dose groups were 0, 8.5 × 101, 8.5 × 104, and 8.5 × 107 cells/g respectively, the infected fish were farmed in an automatic seawater circulation system under a relatively stable temperature, dissolved oxygen and photoperiod, and 3 ~ 6 intestinal samples per group with high-quality DNA assay were used for metagenomics analysis.ResultsThe acute infections with V. alginolyticus at high, medium, and low doses caused the change of different-type leukocytes at 24 h, whereas the joint action of monocytes and neutrophils to cope with the pathogen infection only occurred in the high-dose group at 72 h. The metagenomic results suggest that a high-dose V. alginolyticus infection can significantly alter the intestinal microbiota, decrease the microbial α-diversity, and increase the bacteria from Vibrio and Shewanella, including various potential pathogens at 24 h. High-abundance species of potential pathogens such as V. harveyii, V. parahaemolyticus, V. cholerae, V. vulnificus, and V. scophthalmi exhibited significant positive correlations with V. alginolyticus. The function analysis revealed that the high-dose inflection group could increase the genes closely related to pathogen infection, involved in cell motility, cell wall/ membrane/envelope biogenesis, material transport and metabolism, and the pathways of quorum sensing, biofilm formation, flagellar assembly, bacterial chemotaxis, virulence factors and antibiotic resistances mainly from Vibrios within 72 h.DiscussionIt indicates that the half-smooth tongue sole is highly likely to be a secondary infection with intestinal potential pathogens, especially species from Vibrio and that the disease could become even more complicated because of the accumulation and transfer of antibiotic-resistance genes in intestinal bacteria during the process of V. alginolyticus intensified infection