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Measurement of three-dimensional (3D) turbulence over riblet surfaces is challenging due to the small size of the grooves and the requirement for measurement in the inner layer. The capability of two-dimensional (2D) and 3D particle image velocimetry (PIV) and particle tracking velocimetry (PTV) for characterization of the 3D structure of turbulent flow over a riblet surface with groove spacing of 750 μm at Re τ = 147 (based on friction velocity and half channel height) is investigated. The 2D measurements were carried out using standard planar PIV and high-magnification long-range microscopic PTV (micro-PTV). The investigated 3D techniques include tomographic PIV (tomo-PIV) and 3D-PTV. The results are evaluated in comparison with measurement over a smooth surface and also with direct numerical simulation (DNS) of channel flow by Tsukahara et al. (2005) at Re τ = 150. The reflection of the laser light from the smooth and riblet surfaces is significantly different in spite of the wall-parallel illumination. This resulted in biased near-wall ( y / H y + u 2 〉 peak and its magnitude reduction over the riblet surface compared with planar PIV. The Planar PIV measured 〈 v 2 〉 peak which is further away from the wall at y / H = 0.15 and also the 〈 uv 〉 profile in the outer layer. The 〈 uv 〉 profile showed 7.4% reduction of wall shear stress over the riblet surface. 3D-PTV showed a 9.4% reduction of the 〈 w 2 〉 peak and attenuation of v and w fluctuations over the riblet surface compared to the smooth surface through quadrant analysis. The three components of fluctuating vorticity measured by tomo-PIV showed negligible variation over the two surfaces due to the random noise and lack of spatial resolution. Quadrant analysis using planar PIV showed attenuation of the sweep and ejection events near the riblets, which indicates weaker streamwise vortices. Two-point correlation of PIV measurement also demonstrated increase of the coherence of the low and high-speed steaks over the riblets.

Soil is an important organic carbon (C) pool in terrestrial ecosystems, but knowledge on soil organic carbon (SOC) decomposition rate and influencing factors remains limited, particularly in arid and semi-arid grasslands. Models show that global semi-arid regions are experiencing more extreme climate events, which may trigger more C loss from soils. We used the stable carbon isotope (δ13C) of plant and soil depth profile to examine decomposition rates of SOC along a 2200 km semi-arid grassland transect in northern China. Beta (β) was calculated from the relationship between δ13C and C concentrations of plant and soil profile (0–100 cm). Partial correlation analysis and structure equation models were used to analyze correlations between beta and climatic and edaphic variables. We found that the δ13C values increased from plant tissues to surface soil and then deep soil at all sites, while the SOC concentration decreased. The β values ranged from −0.33 to −2.27, with an average value at −1.37. There was a positive correlation between β value and SOC decomposition rate constant (k), supporting the hypothesis that enrichment of δ13C along soil depth profile was mainly due to isotopic fractionation during microbial SOC decomposition. The correlation between β value and aridity index was mainly due to the variations of edaphic properties such as soil C/N ratio with aridity index, pointing to the more important role of edaphic properties in β value than climatic factors. Despite uncertainties associated with the interpretation of soil δ13C along its depth profile, our results demonstrated that soil δ13C could provide an independent benchmark for examining model-based predictions of SOC decomposition in semi-arid grasslands. Incorporation of both climatic and edaphic variables into models may enhance the predictions for SOC dynamics under global climate changes.

For a graph $G$, let $f(G)$ denote the maximum number of edges in a bipartite subgraph of $G$. For an integer $m$ and for a fixed graph $H$, let $f(m,H)$ denote the minimum possible cardinality of $f(G)$ as $G$ ranges over all graphs on $m$ edges that contain no copy of $H$. We give a general lower bound for $f(m,H)$ which extends a result of Erdős and Lovász and we study this function for any bipartite graph $H$ with maximum degree at most $t\geq 2$ on one side.

Background Long non-coding RNA colorectal neoplasia differentially expressed (lncRNA CRNDE) and microRNA-126-5p (miR-126-5p) were reported to be related to the development of colorectal carcinoma (CRC). However, the detailed mechanism of CRNDE and miR-126-5p is not fully understood. The purpose of this research was to explore their roles and molecular mechanism in CRC. Methods Quantitative real-time polymerase chain reaction was performed to detect the transcription levels of genes. Paclitaxel (PTX) was used to analyze cell drug resistance. 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and flow cytometry analysis were employed to assess cell proliferation and apoptosis, respectively. Furthermore, cell migratory and invasive abilities were measured using transwell assay. The interaction between miR-126-5p and CRNDE or ATPase family AAA domain-containing protein 2 (ATAD2) was predicted by online tool starbase and then confirmed using the dual-luciferase reporter assay. Besides, Western blot assay was carried out to detect the levels of proteins. Results CRNDE and ATAD2 expressions were upregulated and miR-126-5p expression was downregulated in CRC tissues and cells. CRNDE depletion repressed PTX resistance and the growth of CRC cells. Interestingly, we found that miR-126-5p was a target gene of CRNDE, and miR-126-5p directly targeted ATAD2. Furthermore, CRNDE affected CRC cell progression via modulation of miR-126-5p/ATAD2 axis in CRC cells. Conclusion Our data suggested that CRNDE regulated CRC cell development and PTX resistance by modulating miR-126-5p/ATAD2 axis, providing the theoretical basis for the treatment of CRC patients.

Purpose Non-small cell lung cancer (NSCLC) is the largest type of lung cancer (LC) with a higher mortality rate. Circular RNAs (circRNAs) have been shown to play an important role in cancer progression. Therefore, this study was to explore the function of hsa_circ_0043265 in NSCLC. Methods The expression levels of hsa_circ_0043265, microRNA-25-3p (miR-25-3p) and forkhead box P2 (FOXP2) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Ribonuclease R (RNase R) and Actinomycin D (ActD) were used to verify the authenticity and stability of hsa_circ_0043265. Cell counting kit-8 (CCK-8), flow cytometry and transwell assays were used to evaluate the abilities of proliferation, apoptosis, migration and invasion of NSCLC cells. Also, Western blot (WB) analysis was performed to assess the levels of apoptosis, epithelial–mesenchymal transition (EMT) and proliferation-related proteins and FOXP2 protein. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were used to verify the interaction between miR-25-3p and hsa_circ_0043265 or FOXP2. Besides, mice xenograft models were constructed to confirm the effect of hsa_circ_0043265 on NSCLC tumor growth in vivo. Results Hsa_circ_0043265 was lowly expressed in NSCLC tissues and cells, and its overexpression inhibited the proliferation, migration, invasion and EMT process, while improved the apoptosis of NSCLC cells. MiR-25-3p could be sponged by hsa_circ_0043265, and its overexpression could invert the suppression effect of overexpressed-hsa_circ_0043265 on NSCLC progression. Moreover, FOXP2 was a target of miR-25-3p, and its silencing also could reverse the inhibition effect of overexpressed-hsa_circ_0043265 on NSCLC progression. In addition, hsa_circ_0043265 overexpression reduced the tumor growth of NSCLC in vivo. Conclusion Hsa_circ_0043265 could sponge miR-25-3p to improve FOXP2 expression, thereby inhibiting NSCLC progression. This study showed that hsa_circ_0043265 could be a potential biomarker for early diagnosis of NSCLC.

In this study, radial crystallization purification method under induction was proposed for preparing 6N,7N ultra-high purity gallium crystal seed. The effect of cooling temperature on the morphology of the crystal seed, as well as the cooling water temperature, flow rate, and the addition amount of crystal seed on the crystallization process was explored, and the best purification process parameters were obtained as follows: temperature of the crystal seed preparation, 278 K, temperature and flow rate of the cooling water, 293 K and 40 L&middot, h&minus, 1, respectively, and number of added crystal seed, six. The effects of temperature and flow rate of the cooling water on the crystallization rate were investigated. The crystallization rate decreased linearly with increasing cooling water temperature, but increased exponentially with increasing cooling water flow. The governing equation of the crystallization rate was experimentally determined, and three purification schemes were proposed. When 4N crude gallium was purified by Scheme I, 6N high-purity gallium was obtained, and 7N high-purity gallium was obtained by Schemes II and III. The purity of high-purity gallium prepared by the three Schemes I, II, and III was 99.999987%, 99.9999958%, and 99.9999958%, respectively.

An implantable axial blood pump was designed according to the circulation assist requirement of severe heart failure patients of China. The design point was chosen at 3 L/min flow rate with 100 mm Hg pressure rise when the blood pump can provide flow rates of 2-7 L/min. The blood pump with good hemolytic and anti-thrombogenic property at widely operating range was designed by developing a structure that including the spindly rotor impeller structure and the diffuser with splitter blades and cantilevered main blades. Numerical simulation and particle image velocimetry (PIV) experiment were conducted to analyze the hydraulic, flow fields and hemolytic performance of the blood pump. The results showed that the blood pump could provide flow rates of 2-7 L/min with pressure rise of 60.0-151.3 mm Hg when the blood pump rotating from 7 000 to 11 000 r/min. After adding the splitter blades, the separation flow at the suction surface of the diffuser has been reduced efficiently. The cantilever structure changed the blade gap from shroud to hub that reduced the tangential velocity from 6.2 m/s to 4.3-1.1 m/s in blade gap. Moreover, the maximum scalar shear stress of the blood pump was 897.3 Pa, and the averaged scalar shear stress was 37.7 Pa. The hemolysis index of the blood pump was 0.168% calculated with Heuser's hemolysis model. The PIV and simulated results showed the overall agreement of flow field distribution in diffuser region. The blood damage caused by higher shear stress would be reduced by adopting the spindle rotor impeller and diffuser with splitter blades and cantilevered main blades. The blood could flow smoothly through the axial blood pump with satisfactory hydraulics performance and without separation flow.根据中国终末期心衰患者对左心辅助泵辅助人体血液循环的要求，设计以 3 L/min 流量、100 mm Hg 压升为设计点，流量范围为 2～7 L/min 的微型可植入轴流血泵。该血泵采用纺锤形的转子叶轮结构以及带分流叶片、悬臂叶片的尾导结构，以使血泵在较宽的压力流量范围内具有良好的溶血和抗血栓特性。本文用数值模拟及粒子成像测速（PIV）的方法分析血泵的水力学特性、流场及溶血特性。结果表明：血泵转速为 7 000～11 000 r/min 时，在 2～7 L/min 的流量范围内可提供 60.0～151.3 mm Hg 的压升；分流叶片抑制了尾导的尾缘吸力面处的流动分离；悬臂式叶片结构将转子叶片的叶尖间隙变为尾导叶片的叶根间隙，间隙的切线速度由 6.2 m/s 降至 4.3～1.1 m/s；血泵的最大标量剪切应力值为 897.3 Pa，平均剪切应力值为 37.7 Pa；采用 Heuser 溶血模型得到的溶血指数为 0.168%；PIV 试验所得泵内尾导区域的流场速度分布与数值计算得到的流场特征吻合良好。本研究所设计的轴流血泵的尾导具有分流叶片和悬臂叶片，流道内血流无较大分离流动，降低了剪切力对血液的破坏，溶血性能良好，压力流量性能满足临床需要。.

Water has been widely acknowledged as an essential part of all living things. It is the fundamental necessity for all life's activities and most biochemical reactions in human body are executed in water. Therefore, the type and quantity of liquid intake everyday have a critical impact on individuals' health. In this paper, we demonstrate HydraDoctor, a real-time liquids intake monitoring system which is able to detect drinking activities, classify the categories of liquids and estimate the amount of intake. The system runs on multiple platforms including a smartwatch to detect the motion of hands and a smartglass to capture the images of mugs. A smartphone is also used as an edge computing platform and a remote server is designed for computationally intensive image processing. In HydraDoctor, multiple state-of-the-art machine learning techniques are applied: a Support Vector Machine (SVM)-based classifier is proposed to achieve accurate and efficient liquids intake monitoring, which is trained to detect the hand raising action. Both of them are well optimized to enable in-situ processing on smartwatch. To provide more robust and detailed monitoring, the smartglass is also incorporated and trigged to capture a short video clip in the front of the user when potential drinking activity is detected. The smartglass will send the video clip to the remote server via its companion smartphone and a Faster-RCNN is performed on the server to confirm the detected drinking activity and identify the type of intake liquid. According to our evaluation on the real-world experiments, HydraDoctor achieves very high accuracy both in drinking activity detection and types of liquids classification, whose accuracy is 85.64% and 84% respectively.

For positive integers k≥2 and m, let gk(m) be the smallest integer such that for each graph G with m edges there exists a k-partition V(G)=V1∪…∪Vk in which each Vi contains at most gk(m) edges. Bollobas and Scott showed that gk(m)≤mk2+k−12k22m+1/4−1/2. Ma and Yu posed the following problem: is it true that the limsup of mk2+k−12k22m−gk(m) tends to infinity as m tends to infinity? They showed it holds when k is even, establishing a conjecture of Bollobas and Scott. In this article, we solve the problem completely. We also present a result by showing that every graph with a large k-cut has a k-partition in which each vertex class contains relatively few edges, which partly improves a result given by Bollobas and Scott.

Judicious partitioning problems on graphs and hypergraphs ask for partitions that optimize several quantities simultaneously. Let k ≥ 2 be an integer and let G be a hypergraph with mi edges of size i for i=1,2. Bollobás and Scott conjectured that G has a partition into k classes, each of which contains at most $m_1/k+m_2/k^2+O(\sqrt{m_1+m_2})$ edges. In this paper, we confirm the conjecture affirmatively by showing that G has a partition into k classes, each of which contains at most $$m_1/k+m_2/k^2+\ffrac{k-1}{2k^2}\sqrt{2(km_1+m_2)}+O(1)$$. edges. This bound is tight up to O(1).

Given integers $$k\ge 2$$kź2, $$n \ge 2$$nź2, $$m \ge 2$$mź2 and $$ a_1,a_2,\ldots ,a_m \in {\mathbb {Z}}{\backslash }{\{0\}}$$a1,a2,ź,amźZ\{0}, and let $$f(z)= \sum _{j=0}^{n}c_jz^j$$f(z)=źj=0ncjzj be a polynomial of integer coefficients with $$c_n>0$$cn>0 and $$(\sum _{i=1}^ma_i)|f(z)$$(źi=1mai)|f(z) for some integer z. For a k-coloring of $$[N]=\{1,2,\ldots ,N\}$$[N]={1,2,ź,N}, we say that there is a monochromatic solution of the equation $$a_1x_1+a_2x_2+\cdots +a_mx_m=f(z)$$a1x1+a2x2+ź+amxm=f(z) if there exist pairwise distinct $$x_1,x_2,\ldots ,x_m\in [N]$$x1,x2,ź,xmź[N] all of the same color such that the equation holds for some $$z\in \mathbb {Z}$$zźZ. Problems of this type are often referred to as Ramsey-type problems. In this paper, it is shown that if $$a_i>0$$ai>0 for $$1\le i\le m$$1≤i≤m, then there exists an integer $$N_0=N(k,m,n)$$N0=N(k,m,n) such that for $$N\ge N_0$$NźN0, each k-coloring of [N] contains a monochromatic solution $$x_1,x_2,\ldots ,x_m$$x1,x2,ź,xm of the equation $$a_1x_1+a_2x_2+ \cdots +a_mx_m= f(z)$$a1x1+a2x2+ź+amxm=f(z). Moreover, if n is odd and there are $$a_i$$ai and $$a_j$$aj such that $$a_ia_j

Bollobas and Scott showed that the vertices of a graph of m edges can be partitioned into k sets such that each set contains at most m / k 2 + o ( m ) edges. They conjectured that the vertices of an r-uniform hypergraph, where r ? 3 , of m edges may likewise be partitioned into k sets such that each set contains at most m / k r + o ( m ) edges. In this paper, we prove the weaker statement that a partition into k sets can be found in which each set contains at most m ( k - 1 ) r + r 1 / 2 ( k - 1 ) r / 2 + o ( m ) edges. Some partial results on this conjecture are also given.

In 2002, Bollobas and Scott posed the following problem: for an integer k≥2 and a graph G of m edges, what is the smallest f(k, m) such that V(G) can be partitioned into V 1,…,Vk in which e(Vi∪Vj)≤f(k,m) for all 1≤i≠j≤k, where e(Vi∪Vj) denotes the number of edges with both ends in Vi∪Vj? In this paper, we solve this problem asymptotically by showing that f(k,m)≤m/(k−1)+o(m). We also show that V(G) can be partitioned into V1,…,Vk such that e(Vi∪Vj)≤4m/k2+4Δ/k+o(m) for 1≤i≠j≤k, where Δ denotes the maximum degree of G. This confirms a conjecture of Bollobas and Scott. © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 50, 59–70, 2017

Node importance is a key measuring index for network structure characteristics. Evaluating the nodes importance can locate key nodes of the network and provide support for network node planning. The importance of the C4ISR communication node reflects the dependence degree of the functional nodes and functional links on the C4ISR transport nodes. How to transform this qualitative dependence into quantitative dependency measuring is the core problem of evaluating node importance and locating key nodes. Based on the quantitative dependence measuring, this paper proposes a C4ISR communication node importance evaluation method based on multi-attribute decision-making. Meanwhile, the applicability of the method is verified by examples.

Let D be a directed graph. The minimum semidegree of D is defined to be the minimum value of the minimum outdegree and the minimum indegree of D . For nonempty sets S , T ⊆ V ( D ) , we use e ( S , T ) to denote the number of arcs in D from S to T . If D has m arcs and positive minimum semidegree, then we show that D admits a bipartition V ( D ) = V 1 ∪ V 2 such that min { e ( V 1 , V 2 ) , e ( V 2 , V 1 ) } ≥ ( 1 ∕ 6 + o ( 1 ) ) m . We also prove that if the minimum semidegree is at least two (or three, respectively), then the constant can be increased to 1 ∕ 5 (or 3 ∕ 14 , respectively). These partly answer a question of Hou and Wu (2018).

Aiming at the network organization requirements of precise operation, this paper proposes a precise network organization method based on the “network in the chain” model: starting from the command perspective, setting the intelligence chain, C2 chain, strike chain and service chain as the entry points, the organizing and planning of operation network is classified and carried out. The model of “chain in net” is formally described, and the evaluation index system of “chain” to “net” is established. This kind of precise network organization based on command perspective is of great significance to improve the ability of joint operation based on network information system.

The temperature field of the anode rodding process is the root of most of problems related to the anode. A 3D transient thermal finite element model was developed, based on ANSYS in this paper. The temperature field of the rodding process was investigated using this model. The results were presented and analyzed in detail, including the transient temperature fields of different components in the anode, the characteristics of the cast iron solidification, and the cooling rate distribution. The conclusions were as follows. When the stub hole was filled up at 10 s, 30% by volume of cast iron was below the liquidus temperature. At 70 s, the cast iron solidified completely. The cast iron close to the stub solidified prior to that close to the carbon. The solidification mode was intermediate-freezing. The solidifying sequence was vertically from bottom to top, indicating that shrinkage cavities were less likely to occur. The temperature of the stub was higher than the carbon, and portion at high temperature was concentrated around the stub hole. The cooling rate during solidification was 4.3 &deg, C s&minus, 1 to 43.7 &deg, 1, and the gradient on the radial direction was relatively obvious.

For the military scenario named entity, the article proposes a supervised named entity recognition method based on deep neural network, which aims to identify and extract the troops, geographical location, weapons and equipment, organization, facilities, battlefield environment, time, etc. in the military scenario. The method avoids the complexity of artificially constructed features and the inaccuracy of military text segmentation. Bi-directional Long Short-Term Memory neural network based on character vector and the conditional random field model are used to automatically extract text features, and then identify the military scenario named entities. Experiments show that the method is higher in recognition accuracy than the traditional method and close to the level of named entity recognition in the 2eneral field.

Objective To investigate the lung cancer-promoting mechanism of mesenchymal stem cell-secreted extracellular vesicles (MSC-EV). Methods EV were isolated from culture media of human bone marrow-derived MSCs that were pre-challenged with or without hypoxia (referred to as H-EV and N-EV, respectively). After treatment with N-EV or H-EV, A549 and H23 cell proliferation, apoptosis, trans-well invasion and epithelial-to-mesenchymal transition (EMT) were examined. Polarization of human primary monocytes-derived macrophages with or without N-EV or H-EV induction were analyzed by flow cytometry and ELISA. PTEN, PDCD4 or RECK gene was overexpressed in A549 cells, while miR-21-5p was knocked down in MSCs, A549 or H23 lung cancer cells or primary monocytes by miR-21-5p inhibitor transfection. Protein level of PTEN, PDCD4, RECK, AKT or STAT3 as well as phosphorylation level of AKT or STAT3 protein were assayed by western blot. Tumorigenicity of A549 and H23 cells with or without MSC-EV co-injection was assayed on immunocompromised mice. The xenograft tumor were examined for cell proliferation, angiogenesis, apoptosis and intra-tumoral M1/M2 macrophage polarization. Results Comparing to N-EV, H-EV treatment significantly increased A549 and H23 cell proliferation, survival, invasiveness and EMT as well as macrophage M2 polarization. MiR-21-5p knocked down significantly abrogated the cancer-promoting and macrophage M2 polarizing effects of H-EV treatment. H-EV treatment downregulated PTEN, PDCD4 and RECK gene expression largely through miR-21-5p. Overexpressing PTEN, PDCD4 and RECK in A549 cells significantly reduced the miR-21-5p-mediated anti-apoptotic and pro-metastatic effect of H-EV, while overexpressing PTEN in monocytes significantly reduced macrophage M2 polarization after induction with the presence of H-EV. H-EV co-injection significantly increased tumor growth, cancer cell proliferation, intra-tumoral angiogenesis and M2 polarization of macrophages in vivo partially through miR-21-5p. Conclusions Increased miR-21-5p delivery by MSC-EV after hypoxia pre-challenge can promote lung cancer development by reducing apoptosis and promoting macrophage M2 polarization. Electronic supplementary material The online version of this article (10.1186/s13046-019-1027-0) contains supplementary material, which is available to authorized users.

Za graf ?$G$?, naj ?$f(G)$? označuje maksimalno število povezav v dvodelnem podgrafu grafa ?$G$?. Za celo število ?$m \ge 1$? in za množico ?$\mathcal{H}$? grafov, naj ?$f(m, \mathcal{H})$? označuje minimalno možno kardinalnost ?$f(G)$?, ko ?$G$? preteče vse grafe z ?$m$? povezavami, ki ne vsebujejo nobenega člana množice ?$\mathcal{H}$? kot podgrafa. Še posebej, za dani graf ?$H$?, enostavno pišemo ?$f(m, H)$?, za ?$f(m, \mathcal{H})$?, ko je ?$\mathcal{H} = \{H\}$?. Naj bo ?$r > 4$? fiksno sodo celo število. Alon in drugi (2003) so postavili domnevo, da obstaja pozitivna konstanta ?$c(r)$?, za katero je ?$f(m, C_{r-1}) \ge m/2 + c(r)m^{r/(r+1)}$? za vse ?$m$?. V tem članku pokažemo, da je ?$f(m, C_{r-1}) \ge m/2 + c(r)(m^r \log^4 m)^{1/(r+2)}$? za neko pozitivno konstanto ?$c(r)$? in za vse ?$m$?. Za poljubno določeno celo število ?$s \ge 2$? študiramo tudi funkcijo ?$f(m, \mathcal{H})$? za ?$\mathcal{H} = \{K_{2,s}, C_5\}$? in ?$\mathcal{H} = \{C_4, C_5,\dots , C_{r-1}\}$?, kar oboje izboljšuje rezultat Alona in drugih.

Background The main goal of this study was to explore the feasibility of stratifying patients with secondary tricuspid regurgitation (TR) into different risk levels, and to compare the surgical outcomes of patients within different risk levels who underwent different tricuspid valve repair (TVP) approaches. Methods One hundred and one patients with left-sided valvular disease underwent either left-sided valvular replacement or repair, and 79 patients underwent concomitant TVP. Depending upon their tricuspid annulus diameter and tethering distances, the patients were assessed using 4 risk levels. The different surgical approaches were used in patients within different risk levels. Results Among the 101 patients, there were 32 patients within risk level I, 28 within risk level II, 20 within risk level III, 21 within risk level IV. In the first risk level, the patients with untreated tricuspid valves had no or mild TR after surgery. In the second and third risk levels, the patients treated with a modified De Vega procedure had mild TR at follow-up. In the fourth risk level, the patients treated with undersized annuloplasty rings exhibited an improved outcome. Conclusions The evaluation of both tricuspid annular diameter and tethering distance may help clinicians to stratify patients with secondary TR into different risk levels as a means of choosing an optimal TVP approach. The application of a modified De Vega procedure or an undersized annuloplasty ring in patients within appropriate risk level could improve the treatment for secondary TR.

Let G be a graph of maximum degree Δ. A proper vertex coloring of G is acyclic if there is no bichromatic cycle. It was proved by Alon et al. [Acyclic coloring of graphs. Random Structures Algorithms, 1991, 2(3): 277–288] that G admits an acyclic coloring with O(Δ4/3) colors and a proper coloring with O(Δ(k-1)/(k-2)) colors such that no path with k vertices is bichromatic for a fixed integer k ≥ 5. In this paper, we combine above two colorings and show that if k ≥ 5 and G does not contain cycles of length 4, then G admits an acyclic coloring with O(Δ(k-1)/(k-2)) colors such that no path with k vertices is bichromatic.

Augmented reality is through the integration of computer generated virtual images and real environment to let the user access to feel real with rich content experience and human-computer interaction technology. Based on the augmented reality and human body recognition technology, the research builds an interactive augmented reality application of propaganda enterprise culture. Through the test in practical application and comparing the method based on color image recognition of human body parts and the method based on depth image recognition of human body parts, this paper proposes a relevant method of improving the recognition performance.

For many students, course recommendation is a troublesome problem. To choose satisfying courses when they only have a little of information about the courses, they have to turn to common course schedule systems for help, but the result is disappointing. To solve the problem, the method of scoring similarity of courses and clustering courses based on course descriptions is presented. Different from the method, this paper applies semantic similarity analysis into course selection, realizes a course recommendation system. Each course description is first modeled as a document, and a cleantokenize-TFIDF-Word2Vec-Doc2Vec pipeline is built to create vectors for each course from which cosine similarities will be calculated. The result is even better than the above method through evaluation.

So far in China, unconventionally low-permeability oil sandstone resource has become the first contributor of proved reserve, and is occupying the most important section of oil production in near future. The low-permeability reservoirs have been primarily developed by waterflood, and therefore display a series of new and specific features. Among them, dynamic fracture, an important factor influencing waterflood performance, was studied in this paper. This paper is a 5-step study of low-permeability oil sandstone reservoirs (average permeability between 0.3mD and 10mD) in Ordos basin, which is famous for its richness in low-permeability sandstone resources. First, dynamic fractures were identified by production data, injection profile, tracer monitoring and well test data. Secondly, mechanical experiment and discrete numerical simulation were integrated to analyze the forming mechanism of dynamic fractures. Third, remaining oil saturation observation of densely-spaced inspection well cores and unstructured-grid simulations were used in combination to obtain a 3-dimensional sweep scenario influenced by both dynamic fracture and matrix. Based on study above, the impact of dynamic fracture on waterflood was then analyzed. Finally, how to curb and use dynamic fractures to maximize recovery according to their different forming mechanisms were suggested. The dynamic fracture is defined as fracture that reopen, propagate or close influenced by injection pressure. It can be identified by simultaneous features of drastic watercut increasing, sharp spike in GR curve of injection profile, fast breakthrough of tracer and high permeability anomaly by well test. Core sample mechanical experiment and theory calculation support dynamic fractures propagating on the basis of pre-existence fractures as the predominant forming mechanism. Fresh core observation of newly drilled inspection wells after 20y's waterflood indicates a higher percentage of vertical sweep by up to 30% in the direction of dynamic fracture than that perpendicular to the direction of dynamic fracture. Also dynamic fracture simulations show fast growth of dynamic fractures apparently narrows horizontal sweep and causes earlier drastic watercut increasing by years. A fast growing dynamic fracture deteriorates horizontal sweep, while dynamic fractures of a certain height increase vertical sweep. Moderate injection and stimulated fractures with enough height are conducive to enhance sweep and therefore recovery. If dynamic fractures connecting injectors and producers are unavoidable, a line injection pattern is then proposed. This paper conducted a systematic study on dynamic fracture, which is a dominant feature and geological challenge for waterflood of unconventional tight oil sandstone reservoirs. It offers a guidance for future waterflood development of similar reservoirs.

Judicious Partition Problem is to partition the vertex set of a graph such that certain quantities are optimized simultaneously. Let k be a positive integer and G a graph with m edges. It is proved in this paper that the vertex set of G can be partitioned into k parts V 1 , ? , V k such that e ( V i ) ? m k 2 + k - 1 2 k 2 ( 2 m + 1 4 - 1 2 ) + 2 3 for each i ? { 1 , 2 , ? , k } and e ( V 1 , ? , V k ) ? k - 1 k m + k - 1 2 k ( 2 m + 1 4 - 1 2 ) - ( k - 2 ) 2 8 k , where e ( V i ) is the number of edges with both ends in V i and e ( V 1 , ? , V k ) = m - ? i = 1 k e ( V i ) . This partially solves a problem proposed by Bollobas and Scott, and, for some values of m , solves the problem affirmatively.

5-Fluorouracil (5-FU)-based chemotherapy has always been the first-line treatment of colorectal cancer (CRC). However, the occurrence of clinical 5-FU resistance is a major reason for CRC therapy failure. This study intended to explore the possible role of long non-coding RNA HOTAIRM1 (HOTAIRM1) in the pathogenesis of 5-FU resistant CRC and its underlying mechanism. Our data showed that HOTAIRM1 was downregulated in CRC tissues and cell lines (HCT116 and SW480), and even lower in 5-FU resistant CRC tissues and cell lines (HCT116/5-FU and SW480/5-FU). In vitro, effects of HOTAIRM1 dysregulation in 5-FU resistant CRC cells were investigated and its overexpression could reduce cell viability, invasion, migration, and multi-drug resistance as evidenced by MTT assay, Transwell assay, epithelial-mesenchymal transition (EMT), and western blot analyzing expression of drug-resistant genes MRP1 and MDR1, respectively. Mechanically, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) identified that HOTAIRM1 and B-cell translocation gene 3 (BTG3) were target genes of miR-17-5p. Moreover, miR-17-5p was upregulated and BTG3 was downregulated in HCT116/5-FU and SW480/5-FU cells. Silencing of miR-17-5p showed suppressive role on cell viability, invasion, migration, and multi-drug resistance in HCT116/5-FU and SW480/5-FU cells, which could be abolished by HOTAIRM1 knockdown. Similarly, ectopic expression of miR-17-5p reversed BTG3-mediated inhibition on cell viability, invasion, migration, and multi-drug resistance. In vivo, the tumorigenesis of HCT116/5-FU cells when highly expressed HOTAIRM1 by lentivirus infection was inhibited through downregulating miR-17-5p and upregulating BTG3. In conclusion, HOTAIRM1 might act as a tumor-suppressor in 5-FU resistant CRC cells in vitro and in vivo through downregulating miR-17-5p/BTG3 pathway and inhibiting multi-drug resistance.

Earlier, our study demonstrated that lysophosphatidic acid (LPA) receptor mediated cardiomyocyte hypertrophy. However, the subtype-specific functions for LPA1 and LPA3 receptors in LPA-induced hypertrophy have not been distinguished. Growing evidence indicates that microRNAs (miRNAs) are involved in the pathogenesis of cardiac hypertrophy by down-regulating target molecules. The present work therefore aimed at elucidating the functions mediated by different subtypes of LPA receptors and investigating the modulatory role of miRNAs during LPA induced hypertrophy. Experiments were done with cultured neonatal rat cardiomyocytes (NRCMs) exposed to LPA and we showed that knockdown of LPA1 by small interfering RNA (siRNA) enhanced LPA-induced cardiomyocyte hypertrophy, whereas LPA3 silencing repressed hypertrophy. miR-23a, a pro-hypertrophic miRNA, was up-regulated by LPA in cardiomyocytes and its down-regulation reduced LPA-induced cardiomyocyte hypertrophy. Importantly, luciferase reporter assay confirmed LPA1 to be a target of miR-23a, indicating that miR-23a is involved in mediating the LPA-induced cardiomyocyte hypertrophy by targeting LPA1. In addition, knockdown of LPA3, but not LPA1, eliminated miR-23a elevation induced by LPA. And PI3K inhibitor, LY294002, effectively prevented LPA-induced miR-23a expression in cardiomyocytes, suggesting that LPA might induce miR-23a elevation by activating LPA3 and PI3K/AKT pathway. These findings identified opposite subtype-specific functions for LPA1 and LPA3 in mediating cardiomyocyte hypertrophy and indicated LPA1 to be a target of miR-23a, which discloses a link between miR-23a and the LPA receptor signaling in cardiomyocyte hypertrophy.

A graph is $$1$$1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this paper, we confirm the total-coloring conjecture for 1-planar graphs with maximum degree at least 13.

A proper coloring of a graph G is acyclic if G contains no 2-colored cycle. A graph G is acyclically L-list colorable if for a given list assignment L = {L(v): v ∈ V (G)}, there exists a proper acyclic coloring φ of G such that φ(v) ∈ L(v) for all v ∈ V (G). If G is acyclically L-list colorable for any list assignment L with |L(v)| ≥ k for all v ∈ V (G), then G is acyclically k-choosable. In this article, we prove that every toroidal graph is acyclically 8-choosable.

In this paper, we design and implement an effective framework for interaction simulation based on real shadows and virtual shadows. Within the specified depth range, we firstly identify different physical objects with the method of HSV. And then in order to get the position of interaction tool, we use central moment to find the centroid of the physical object. In addition, the gesture recognition method is based on the shadow images by a web camera. Firstly, we set the region of interest on the screen. Secondly, we separate the hand shadows by the binary image. Finally, we use the convex hull, the defect and Hu's invariant moment methods to distinguish gestures and motions based on geometrical feature. The registered virtual shadows will create and interact according to the change of the real shadows. In the end, several special experiments show that our shadow-based simulation framework has well recognition and tracking efficiency.

Background Chlorophenols are environmental contaminants, which are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing chlorophenols, compared to the traditional physical–chemical processes. Results In this study, we first developed an efficient process for the biodegradation of chlorophenols by magnetically immobilized Rhodococcus rhodochrous cells. R. rhodochrous DSM6263 degrades chlorophenols following the first step of hydroxylation at the ortho-positions of chlorophenolic rings. The cells immobilized by k-carrageenan with 9 g/L Fe3O4 nanoparticles could efficiently degrade 2-chlorophenol, 4-chlorophenol, 2,3-dichlorophenol and their mixture, which were even higher than those by free cells. The magnetically nanoparticle-immobilized cells could be used at least for six cycles. Conclusion Given the much easier separation by an external magnetic field and high degradation efficiency, this study provides a promising technique for improving biocatalysts used in the bioremediation process for chlorophenols in wastewater.

Objective Our objective was to reveal the contribution of preoperative high-sensitivity C-reactive protein (hsCRP) levels to the risk of depression in patients undergoing coronary artery bypass grafting (CABG). Methods In this study, 232 consecutive patients undergoing elective CABG were evaluated for depression utilizing the 9-item Patient Health Questionnaire scale at least 3 days before surgery and 6 months after CABG. In addition, peripheral blood samples were collected at baseline and the circulation levels of hsCRP were measured. Results The preoperative and postoperative rate of depression was 18.1%. Interestingly, preoperative depression was independently associated with women (odds ratio [OR], 2.49; 95% confidence interval [CI], 1.13-5.50) and log-transformed hsCRP (OR, 1.16; 95% CI, 1.06-1.27) after adjusting for various factors using logistic regression, including age, sex, and university-level education. Postoperative depression was only associated with log-transformed hsCRP (OR, 1.15; 95% CI, 1.05-1.25) in these patients. Log-transformed hsCRP remained associated with future depression after adjusting for postoperative medications or major adverse cardiovascular events during the follow-up period. Conclusions The present study is the first to report elevated serum hsCRP is an independent predictor for depression in CABG patients not only preoperatively but also up to 6 months after surgery. These clinical findings may reveal a potential target for improving prognosis in CABG patients with depression.

A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic chromatic index of G, denoted by x′a(G), is the least number of colors such that G has an acyclic edge k-coloring. Let G be a graph with maximum degree Δ and girth g(G), and let 1 ⩽ r ⩽ 2Δ be an integer. In this paper, it is shown that there exists a constant c > 0 such that if \(g(G) \geqslant \frac{{c\Delta }} {r}\log \left( {\Delta ^2 /r} \right)\) then x′a(G) ⩽ Δ+r + 1, which generalizes the result of Alon et al. in 2001. When G is restricted to series-parallel graphs, it is proved that x′a(G) = Δ if Δ ⩾ 4 and g(G) ⩾ 4; or Δ ⩾ 3 and g(G) ⩾ 5.

Suppose that G is a planar graph with maximum degree Δ. In this paper it is proved that G is total-(Δ + 2)-choosable if (1) Δ ≥ 7 and G has no adjacent triangles (i.e., no two triangles are incident with a common edge); or (2) Δ ≥ 6 and G has no intersecting triangles (i.e., no two triangles are incident with a common vertex); or (3) Δ ≥ 5, G has no adjacent triangles and G has no k-cycles for some integer k ∈ {5, 6}.

Acyclic coloring problem is a specialized problem that arises in the efficient computation of Hessians. A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic chromatic index of G, denoted by @g"a^'(G), is the least number of colors in an acyclic edge coloring of G. Let G be planar graphs with girth g and maximum degree @D. In this paper, it is shown that if g>=4 and @D>=8, then @g"a^'(G)@?@D+3; if g>=5 and @D>=10 or g>=6 and @D>=6, then @g"a^'(G)=@D.

A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic edge chromatic number of G, denoted by a′(G), is the least number of colors in an acyclic edge coloring of G. Alon et al. conjectured that a′(G) ≤ Δ(G) + 2 for any graphs. In this paper, it is shown that the conjecture holds for planar graphs without 4- and 5-cycles or without 4- and 6-cycles.

Let G be a simple graph embedded in a surface Σ of Euler characteristic χ(Σ)≥0, and let χ'(G) and Δ denote the chromatic index and the maximum degree of G, respectively. The paper shows that χ'(G)=Δ if Δ≥6 and G does not contain chordal-4-cycles or Δ≥5 and G does not contain 4-cycles.

We suggested that low-level laser irradiation (LLLI) precondition prior to cell transplantation might remodel the hostile milieu of infarcted myocardium and subsequently enhance early survival and therapeutic potential of implanted bone marrow mesenchymal stem cells (BMSCs). Therefore, in this study we wanted to address: (1) whether LLLI pre-treatment change the local cardiac micro-environment after myocardial infarction (MI) and (2) whether the LLLI preconditions enhance early cell survival and thus improve therapeutic angiogenesis and heart function. MI was induced by left anterior descending artery ligation in female rats. A 635 nm, 5 mW diode laser was performed with energy density of 0.96 J/cm2 for 150 sec. for the purpose of myocardial precondition. Three weeks later, qualified rats were randomly received with LLLI precondition (n= 26) or without LLLI precondition (n= 27) for LLLI precondition study. Rats that received thoracotomy without coronary ligation were served as sham group (n= 24). In the cell survival study, rats were randomly divided into 4 groups: serum-free culture media injection (n= 8), LLLI precondition and culture media injection (n= 8), 2 million male BMSCs transplantation without LLLI pre-treatment (n= 26) and 2 million male BMSCs transplantation with LLLI precondition (n= 25) group, respectively. Vascular endothelial growth factor (VEGF), glucose-regulated protein 78 (GRP78), superoxide dismutase (SOD) and malondialdehyde (MDA) in the infarcted myocardium were evaluated by Western blotting, real-time PCR and colorimetry, respectively, at 1 hr, 1 day and 1 week after laser irradiation. Cell survival was assayed with quantitative real-time PCR to identify Y chromosome gene and apoptosis was assayed with transferase-mediated dUTP end labelling staining. Capillary density, myogenic differentiation and left ventricular function were tested by immunohistochemistry and echocardiography, respectively, at 1 week. After LLLI precondition, increased VEGF and GRP78 expression, as well as the enhanced SOD activity and inhibited MDA production, was observed. Compared with BMSC transplantation and culture media injection group, although there was no difference in the improved heart function and myogenic differentiation, LLLI precondition significantly enhanced early cell survival rate by 2-fold, decreased the apoptotic percentage of implanted BMSCs in infarcted myocardium and thus increased the number of newly formed capillaries. Taken together, LLLI precondition could be a novel non-invasive approach for intraoperative cell transplantation to enhance cell early survival and therapeutic potential.

A total k-coloring of a graph G is a coloring of V(G) ∪ E(G) using k colors such that no two adjacent or incident elements receive the same color. The total chromatic number χ″(G) is the smallest integer k such that G has a total k-coloring. In this paper, it is proved that the total chromatic number of any graph G embedded in a surface Σ of Euler characteristic χ(Σ) ⩾ 0 is Δ(G) + 1 if Δ(G) ⩾ 10, where Δ(G) denotes the maximum degree of G.

Suppose that G is a planar graph with maximum degree @D and without intersecting 4-cycles, that is, no two cycles of length 4 have a common vertex. Let @g^''(G), @g"l^'(G) and @g"l^''(G) denote the total chromatic number, list edge chromatic number and list total chromatic number of G, respectively. In this paper, it is proved that @g^''(G)=@D+1 if @D>=7, and @g"l^'(G)=@D and @g"l^''(G)=@D+1 if @D(G)>=8. Furthermore, if G is a graph embedded in a surface of nonnegative characteristic, then our results also hold.

Let G be a graph with vertex set V ( G ) . A spanning subgraph F of G is called a [ k , k + 1 ] -factor if k ≤ d F ( x ) ≤ k + 1 for every x ∈ V ( F ) . F is called a connected factor of G if F is connected. In this work we present a sufficient condition for the existence of connected [ k , k + 1 ] -factors in graphs. The condition involves the stability number and degree conditions of graph G .

Background Preoperative renal dysfunction has been an important predictor for adverse cardiovascular events after coronary artery bypass grafting (CABG). In the past, serum creatinine was widely used to assess renal function. Until recently, estimated glomerular filtration rate (eGFR) was recommended in evaluating renal function. The Cockcroft-Gault formula and the Modification of Diet in Renal Disease (MDRD) equation are two widely used formulas in clinical practice. Which method best predicts long-term outcome after CABG is still unknown. This study compared the predictive effectiveness of the Cockcroft-Gault formula, the MDRD equation, and serum creatinine level for in-hospital and long-term mortality. Methods We retrospectively reviewed data collected from 5559 patients who underwent isolated CABG at Fuwai Hospital from January 1999 to December 2005. The main outcomes were in-hospital and long-term mortality. Receiver operating characteristic (ROC) curves and Cox analysis were used for the comparison. Results Mean follow-up was 56.5 ± 24.6 months. ROC curve analysis showed that the Cockcroft-Gault formula had the greatest accuracy for predicting in-hospital mortality (area under the curve, 0.755; p ω 0.001). Multivariate analysis confirmed that the eGFR based on the Cockcroft-Gault formula was an independent predictor of in-hospital (odds ratio, 4.51, p ω 0.001) and long-term (hazard ratio, 1.54; p = 0.003) mortality. Both formulas were better than the serum creatinine level. Conclusions Both formulas could provide a better measure of risk assessment than serum creatinine for in-hospital and long-term mortality. The Cockcroft-Gault formula was better than the MDRD equation for predicting in-hospital mortality.

A proper edge coloring of a graph G is called acyclic if there is no 2-colored cycle in G. The acyclic edge chromatic number of G, denoted by a′(G), is the least number of colors in an acyclic edge coloring of G. Alon et al. conjectured that a′(G) ⩽ Δ(G) + 2 for any graphs. For planar graphs G with girth g(G), we prove that a′(G) ⩽ max{2Δ(G) − 2, Δ(G) + 22} if g(G) ⩾ 3, a′(G) ⩽ Δ(G) + 2 if g(G) ⩾ 5, a′(G) ⩽ Δ(G) + 1 if g(G) ⩾ 7, and a′(G) = Δ(G) if g(G) ⩾ 16 and Δ(G) ⩾ 3. For series-parallel graphs G, we have a′(G) ⩽ Δ(G) + 1.

A graph G is edge-L-colorable, if for a given edge assignment L={L(e):e@?E(G)}, there exits a proper edge-coloring @f of G such that @f(e)@?L(e) for all e@?E(G). If G is edge-L-colorable for every edge assignment L with |L(e)|>=k for e@?E(G), then G is said to be edge-k-choosable. In this paper, we prove that if G is a planar graph without non-induced 5-cycles, then G is edge-k-choosable, where k=max{7,@D(G)+1}.

Let G be a planar graph without adjacent 3-cycles, that is, two cycles of length 3 are not incident with a common edge. In this paper, it is proved that the total coloring conjecture is true for G; moreover, if Δ(G)≥9, then the total chromatic number χ″(G) of G is Δ(G)+1. Some other related results are obtained, too.

Background and Objectives: Bone marrow derived mesenchymal stem cells (BMSCs) have shown to be an appealing source for cell therapy and tissue engineering. Previous studies have confirmed that the application of low-level laser irradiation (LLLI) could affect the cellular process. However, little is known about the effects of LLLI on BMSCs. The aim of this study was designed to investigate the influence of LLLI at different energy densities on BMSCs proliferation, secretion and myogenic differentiation. Study Design/Materials and Methods: BMSCs were harvested from rat fresh bone marrow and exposed to a 635 nm diode laser (60 mW; 0, 0.5, 1.0, 2.0, or 5.0 J/cm 2 ). The lactate dehydrogenase (LDH) release was used to assess the cytotoxicity of LLLI at different energy densities. Cell proliferation was evaluated by using 3-(4, 5-dimethylithiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) and 5-bromo-2 0 -deoxyuridine (BrdU) assay. Production of vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) were measured by enzyme-linked immunosorbent assay (ELISA). Myogenic differentiation, induced by 5-azacytidine (5-aza), was assessed by using immunocytochemical staining for the expression of sarcomeric a-actin and desmin. Results: Cytotoxicity assay showed no significant difference between the non-irradiated group and irradiated groups. LLLI significantly stimulated BMSCs proliferation and 0.5 J/cm 2 was found to be an optimal energy density. VEGF and NGF were identified and LLLI at 5.0 J/cm 2 significantly stimulated the secretion. After 5-aza induction, myogenic differentiation was observed in all groups and LLLI at 5.0 J/cm 2 dramatically facilitated the differentiation. Conclusions: LLLI stimulates proliferation, increases growth factors secretion and facilitates myogenic differentiation of BMSCs. Therefore, LLLI may provide a novel approach for the preconditioning of BMSCs in vitro prior to transplantation. Lasers Surg. Med. 40:726–733, 2008. 2008 Wiley-Liss, Inc.