256 research outputs found

    3-Factor-criticality in double domination edge critical graphs

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    A vertex subset SS of a graph GG is a double dominating set of GG if N[v]S2|N[v]\cap S|\geq 2 for each vertex vv of GG, where N[v]N[v] is the set of the vertex vv and vertices adjacent to vv. The double domination number of GG, denoted by γ×2(G)\gamma_{\times 2}(G), is the cardinality of a smallest double dominating set of GG. A graph GG is said to be double domination edge critical if γ×2(G+e)<γ×2(G)\gamma_{\times 2}(G+e)<\gamma_{\times 2}(G) for any edge eEe \notin E. A double domination edge critical graph GG with γ×2(G)=k\gamma_{\times 2}(G)=k is called kk-γ×2(G)\gamma_{\times 2}(G)-critical. A graph GG is rr-factor-critical if GSG-S has a perfect matching for each set SS of rr vertices in GG. In this paper we show that GG is 3-factor-critical if GG is a 3-connected claw-free 44-γ×2(G)\gamma_{\times 2}(G)-critical graph of odd order with minimum degree at least 4 except a family of graphs.Comment: 14 page

    Analysis of temperature field for a surface-mounted and interior permanent magnet synchronous motor adopting magnetic-thermal coupling method

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    Aiming at obtaining high power density of surface-mounted and interior permanent magnet synchronous motor (SIPMSM), it is important to accurately calculate the temperature field distribution of SIPMSM, and a magnetic-thermal coupling method is proposed. The magnetic-thermal coupling mechanism is analyzed. The thermal network model and finite element model are built by this method, respectively. The effects of power frequency on iron losses and temperature fields are analyzed by the magnetic-thermal coupling finite element model under the condition of rated load, and the relationship between the load and temperature field is researched under the condition of the synchronous speed. In addition, the equivalent thermal network model is used to verify the magnetic-thermal coupling method. Then the temperatures of various nodes are obtained. The results show that there are advantages in both computational efficiency and accuracy for the proposed coupling method, which can be applied to other permanent magnet motors with complex structures

    Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration

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    Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration (IVDD). However, the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells (BMSCs) transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis. Herein, we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10 (Co-Q10), a promising hydrophobic antioxidant which targets mitochondria ROS, into the lecithin micelles, which renders the insoluble Co-Q10 dispersible in water as stable colloids. These micelles are injectable, which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro, and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models. Compared to mere use of Co-Q10, the Co-Q10 loaded micelle possessed better bioactivities, which elevated the viability, restored mitochondrial structure as well as function, and enhanced production of ECM components in rat BMSCs. Moreover, it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model. Therefore, these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS, and might be a potential therapeutic agent for IVDD

    Influence of coal structure and macrolithotype of coal on coal adsorption and desorption of gas

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    In order to study the influence of coal body structure and macrolithotype of coal in high rank coal on coal body adsorption and desorption, The data of coal petrography, coal quality, isothermal adsorption and desorption of 79 coal rock samples from 55 coal-bed methane wells in No.3 Coal Seam in the south of Qinshui Basin were collected, and the change laws in the Langmuir volume (VL), Langmuir pressure (PL), desorption rate of coal samples with the same macrolithotype of coal, different coal body structures and the same coal body structure, different macrolithotype of coal of coal samples, were discussed in the influential mechanisms of coal body structure and macrolithotype of coal on coal body adsorption and desorption. The results show that the average VL of coal samples in the study area is 37.00 m3/t, of which 86.61% is distributed in 33.00—41.00 m3/t, and the average PL is 2.82 MPa, of which 82.28% is distributed in 2.30~3.30 MPa. The adsorption and desorption capacities of fractured coal are better than those of primary structure coal and the difference of pore connectivity caused by structural destruction is the fundamental reason for the difference of desorption and adsorption characteristics between primary structural coal and fractured coal; The development degree of pores and fissures of primary structure coal is different from that of fractured coal. The methane emission effect of fractured coal is better than that of primary structure coal because of more developed pores. The decreasing rule of surface free energy of coal for methane adsorption is the mylonitic coal > granulitic coal > fractured coal > primary structure coal, which reflects the difference of methane adsorption capacity of coal with different coal structure; the adsorption and desorption capabilities of the three types of macro coals are bright coal > semibright coal > semidull coal. On the one hand, the specific surface area of coal decreases roughly in the order of bright coal, semibright coal, and semidull coal, which reflects the difference in adsorption sites on the surface of the coal matrix. On the other hand, it is caused by the difference of vitrinite and inertinite content between vitrain and durain. The purpose of this study is to further reveal the occurrence and production mechanism of CBM in high-rank coal reservoirs, and to provide a basis for the optimization of CBM favorable areas and target horizons

    HMGB1 cytoplasmic translocation in patients with acute liver failure

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    <p>Abstract</p> <p>Background</p> <p>High-mobility group box 1 (HMGB1) is a late mediator of lethal systemic inflammation. Acute liver failure (ALF) has been shown to trigger systemic inflammation in clinical and animal studies. To evaluate the possibility of HMGB1 cytoplasmic translocation in ALF, we determined whether HMGB1 is released in hepatocytes and end organ in patients with liver failure/injury.</p> <p>Methods</p> <p>HepG2 cell were stimulated with LPS or TNF-α, the increase of HMGB1 extracellularly in the culture medium and intracellularly in various cellular fractions were determined by western blot or immunocytochemistry. To observe sub-cellular location of HMGB1 in hepatocytes, liver specimens were obtained from 6 patients with ALF caused by HBV infection, 10 patients with chronic viral hepatitis B, 6 healthy controls, as well as animals model of ALF by intraperitoneal administration of D-GalN (600 mg/kg) and LPS (0.5 mg/kg).</p> <p>Results</p> <p>In HepG2 cell culture, LPS or TNF actively induced HMGB1 cytoplasmic translocation and release in a time- and dose-dependent fashion. In animal model of ALF, cytoplasmic HMGB1 translocation was observed in hepatocyts as early as 3 hours post onset of ALF. In patients with ALF caused by HBV infection, cytoplasmic HMGB1 translocation was similarly observed in some hepatocytes of the liver specimen.</p> <p>Conclusions</p> <p>Cytoplasmic HMGB1 translocation may occur during ALF, which may potentially contribute to the pathogenesis of liver inflammatory diseases.</p

    Genome-Wide Mapping of DNA Methylation in Chicken

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    Cytosine DNA methylation is an important epigenetic modification termed as the fifth base that functions in diverse processes. Till now, the genome-wide DNA methylation maps of many organisms has been reported, such as human, Arabidopsis, rice and silkworm, but the methylation pattern of bird remains rarely studied. Here we show the genome-wide DNA methylation map of bird, using the chicken as a model organism and an immunocapturing approach followed by high-throughput sequencing. In both of the red jungle fowl and the avian broiler, DNA methylation was described separately for the liver and muscle tissue. Generally, chicken displays analogous methylation pattern with that of animals and plants. DNA methylation is enriched in the gene body regions and the repetitive sequences, and depleted in the transcription start site (TSS) and the transcription termination site (TTS). Most of the CpG islands in the chicken genome are kept in unmethylated state. Promoter methylation is negatively correlated with the gene expression level, indicating its suppressive role in regulating gene transcription. This work contributes to our understanding of epigenetics in birds

    アミノサン カラ ユウドウサレル ラセンジョウ ポリアセチレン ノ ゴウセイ ト キノウカ

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    京都大学0048新制・課程博士博士(工学)甲第12609号工博第2722号新制||工||1391(附属図書館)UT51-2006-S617京都大学大学院工学研究科高分子化学専攻(主査)教授 増田 俊夫, 教授 木村 俊作, 教授 赤木 和夫学位規則第4条第1項該当Doctor of EngineeringKyoto UniversityDA

    The Complexity of Secure Domination Problem in Graphs

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    A dominating set of a graph G is a subset D ⊆ V (G) such that every vertex not in D is adjacent to at least one vertex in D. A dominating set S of G is called a secure dominating set if each vertex u ∈ V (G) \ S has one neighbor v in S such that (S \ {v}) ∪ {u} is a dominating set of G. The secure domination problem is to determine a minimum secure dominating set of G. In this paper, we first show that the decision version of the secure domination problem is NP-complete for star convex bipartite graphs and doubly chordal graphs. We also prove that the secure domination problem cannot be approximated within a factor of (1−ε) ln |V | for any ε > 0, unless NP⊆DTIME (|V |O(log log |V|)). Finally, we show that the secure domination problem is APX-complete for bounded degree graphs

    Facile preparation of soluble poly(2-aminothiazole)-based composite coating for enhanced corrosion protection in 3.5% NaCl solution

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    Conducting polymer-based coating is the prospective alternative in consideration of environmentfriendly coatings for corrosion protection of metallic substrate. Minimally-researched poly(2-aminothiazole) (PAT) with well-dispersion and good processability was synthesized successfully via radical polymerization and explored to prepare novel PAT/epoxy composite coatings on Q235 steel. The anticorrosive performance of PAT-based composite coatings was evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization technique and scanning vibrating electrode technique in 3.5 wt % NaCl solution. The corrosion protective mechanism of poly(2-aminothiazole) was proved by the identification of rust layer beneath the composite coating
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