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To explore and describe the experience of decision-making for patients with disorders of consciousness (DOC) from the perspectives of family surrogate decision-makers. A total of 21 face-to-face interviews with family surrogate decision-makers from a tertiary hospital in Shanghai, China were conducted from January 2021 to February 2021. Thematic analysis was used for data analysis. Four main themes were identified and were included in this study: (1) a tough choice between life and dignity, (2) a major responsibility for patient's voice, (3) complex considerations between ethics and morals, and (4) the importance of realistic basis. The surrogate decision-making of DOC patients in China has been affected by the Chinese cultural context and several practical roots. And the family surrogate decision-makers shared their experiences of trade-offs during the decision-making process. Moreover, family surrogate decision-makers realized their serious responsibility to make a decision that would be in the best interest of DOC patients.

This study examined the association between post-stroke cognitive function and sleep status at 30 days post-stroke and evaluated the role of anxiety and depression as potential mediators of that association. The participants in this study were 530 acute ischemic stroke (IS) patients. Sleep disturbance at 30 days post-stroke was assessed by the Pittsburgh Sleep Quality Index. Basic patient information, cognitive function, depression, and anxiety status were assessed before discharge from the hospital. Stratified linear regression analysis models were fit to examine the associations between post-stroke sleep quality and the influencing factors. A structural equation model was developed to evaluate the role of anxiety and depression as potential mediators of sleep quality and cognitive function. At 30 days post-stroke, 58.7% of IS patients had sleep disturbance. Women and older IS patients were more likely to suffer poorer sleep quality (p < 0.05). A stratified linear regression analysis showed that the inclusion of cognitive function variables and indicators of depression and anxiety were statistically significant in predicting improvement in the sleep disturbance of AIS patients. Cognitive function, depression, anxiety, and sleep status were selected to construct a structural equation model. The total effect of cognitive function on sleep status was −0.274, with a direct effect of −0.097 and an indirect effect (through depression) of −0.177. The total effect of anxiety on sleep status was 0.235, with a direct effect of 0.186 and an indirect effect (through depression) of 0.049. IS patients often experience poor sleep quality. Depression in IS patients mediates two pathways: the pathway through which cognitive function affects sleep quality and the pathway through which anxiety affects sleep quality.

In a type-2 fuzzy logic system, one of the important operations is to calculate the centroid of an interval type-2 fuzzy set (IT2 FS). In this paper, two novel algorithms called binary algorithms are proposed to calculate the centroid of IT2 FSs. Then, the outputs of the proposed binary algorithms are proven to be the optimal values. After analyzing the computational complexities of Karnik-Mendel (KM) algorithms, enhanced Karnik-Mendel (EKM) algorithms, enhanced iterative algorithms based on stopping condition (EIASC) algorithms and the proposed binary algorithms, it is found that the proposed binary algorithms are superior to the KM algorithms, EKM algorithms and EIASC algorithms. Finally, two extended binary algorithms are proposed to compute the centroid of an IT2 FS. The efficiencies of the proposed binary algorithms and extended binary algorithms are demonstrated by extensive simulations.

For a given simple graph $$G=(V,E)$$ , a latency bound t and a threshold function $$\theta (v)=\lceil \rho d(v)\rceil $$ , where $$\rho \in (0,1)$$ and d(v) denotes the degree of the vertex $$v(\in V)$$ , a subset $$S\subseteq V$$ is called a strong target set if for each vertex $$v\in S$$ , the number of its neighborhood in S not including itself is at least $$\theta (v)$$ , and all vertices in V can be activated by S through a process with t rounds. Initially, all vertices in S become activated. At the ith round of the process, each vertex is activated if the number of active vertices in its neighbor after $$i-1$$ rounds exceeds its threshold. The $$t$$ -Latency Bounded Strong Target Set Selection (t-LBSTSS) problem is to find such a strong target set S with the minimum cardinality in G. In general graphs, the t-LBSTSS problem is not only NP-hard, but also hard to be approximated. The aim of this paper is to find an optimal t-latency bounded strong target set for some special family of graphs. For a given simple graph G, a simple, tight but nontrivial inequality in terms of the number of edges in G is proposed to obtain the lower bound of the sum of degrees in a strong target set S to the t-LBSTSS problem. Moreover, a necessary and sufficient condition is presented for equality to hold. Finally, we give the exact formulas for the optimal solutions to the t-LBSTSS problem in two kinds of natural family of graphs, while it seems difficult to tell without the inequality given in this paper.

Computing the centroid of an interval type-2 fuzzy set (IT2 FS) is an important type-reduction method. The aim of this paper is to develop a new method to calculate the centroid of an IT2 FS when the problems of centroid computation of an IT2 FS are continuous. For the continuous centroid computation problems, the structures of optimal solutions are strictly proven from mathematics for the first time in this paper. Furthermore, we also prove that the structures of the optimal solutions are unique in the sense of almost everywhere equal, i.e., if there are two optimal solutions $f_1(x)$ and $f_2(x)$ , the Lebesgue measure of $\{x|f_1(x)\neq f_2(x)\}$ is equal to 0. Subsequently, a combinatorial iterative (CI) method is proposed to solve the roots of the sufficiently differentiable objective functions. It is proven that the convergence of the proposed iterative method is at least sixth order. Based on the proposed iterative method, two algorithms, called CI algorithms, are devised to compute the centroid of an IT2 FS. The efficiencies of CI algorithms are demonstrated by comparing the continuous Karnik–Mendel algorithms and the Hallye's methods with the CI algorithms through three numerical examples.

Aiming at the signal of marine gear is always with large noise and difficult to extract the fault features, a fault diagnosis method based on variational mode decomposition (VMD) and multiscale dispersion entropy (MDE) is proposed. The marine gear vibration signal was transformed by the VMD, the problem of parameter selection which affects the decomposition accuracy of VMD was studied, and the corresponding parameter selection method was proposed. Later, the intrinsic mode functions (IMFs) which can effectively characterize the signal characteristics were selected by frequency domain correlation coefficient and energy fluctuation coefficient, and reconstruction signal was formed. Finally, the MDE value of the reconstruction signal was calculated and used to compose the multiscale feature vector, the vector as input to the least squares support vector machines (LS-SVM) for fault diagnosis. Through the analysis of the test gear vibration signal, and the comparison is made with common signal decomposition method, the results show that the proposed method can effectively realize the fault diagnosis of gear.

In total, 97 acute ST-segment elevation myocardial infarction (STEMI) patients who received an emergency percutaneous coronary intervention (PCI) were enrolled and divided into a ticagrelor group and a clopidogrel group. Thrombolysis in myocardial infarction (TIMI) blood flow and the corrected TIMI frame count (CTFC) were used to assess the blood perfusion of culprit vessels. Thromboelastography (TEG) was used to evaluate the antiplatelet effect of drugs. The results showed that the incidence of TIMI grade III blood flow in the ticagrelor group was significantly higher than that in the clopidogrel group. The CTFC in the anterior descending, circumflex, and right coronary arteries was statistically significantly lower in the ticagrelor group as compared with that in the clopidogrel group. At 2 h and 7 d postdrug treatment, the adenosine diphosphate-induced platelet inhibition rate (ADP%) in the ticagrelor group increased significantly as compared with that in the clopidogrel group, and the platelet aggregation rate of the ADP pathway (MAADP) decreased significantly in the ticagrelor group versus that in the clopidogrel group. In conclusion, ticagrelor significantly improved TIMI blood flow and had a better antiplatelet effect than clopidogrel in STEMI patients undergoing an emergency PCI.

Background Treatment for breast cancer can be stressful for patients. Cognitive-behavioral stress management (CBSM) interventions aim to improve patients' skills in coping with stress and buffer against the negative effects of cancer. Objectives This meta-analysis aimed to demonstrate the impact of CBSM on breast cancer patients. Methods We searched PubMed, EMBASE, the Cochrane Database, ScienceDirect, MEDLINE, CENTRAL, CINAHL, and PsycNET for randomized controlled trials (RCTs) published up to November 21, 2017. We then performed a meta-analysis of RCTs that compared CBSM for patients with breast cancer with a 1-day psychoeducation seminar, wait-list controls, or standard care. Results Eighteen RCTs with 2564 participants were ultimately included. The results showed that CBSM can increase Measure of Current Status relaxation scores, benefit finding, and positive affect and decrease serum cortisol, anxiety, depression, thought avoidance and intrusion, and negative mood. However, it appears to have no effect on stress or mood disturbance. Conclusions Cognitive-behavioral stress management appears to be beneficial for breast cancer patients. Further high-quality RCTs are needed to clarify if any other factors are influenced by CBSM intervention. Implications for practice Cognitive-behavioral stress management can help breast cancer patients develop skills to increase relaxation, benefit finding, and positive affect; CBSM may provide a buffer against the negative effects of cancer. Further, CBSM may help breast cancer patients replace negative thoughts, improve their thought processes and behaviors, and maintain social support using cognitive and interpersonal coping skills. Nurses should be aware of the benefits of CBSM in their day-to-day care of breast cancer patients.

Nowadays, the thermomagnetic generators (TMGs) based on thermomagnetic effect have been considered as a promising technology for harvesting low-grade waste heat. However, so far, most works are mainly focused on the design and optimization of these devices, while only a few studies have systematically investigated the TMG materials; moreover, evaluating the performance of different TMG materials is quite difficult. This paper reports the fabrication of an active thermomagnetic device for harvesting low-grade waste heat and, for the first time, a systematical performance evaluation of classic magnetocaloric materials (Gd, Gd5(Si, Ge)4, NiMn-based Heusler alloy, and La(Fe, Si)13Hy/In composite). Alternating current (I) was obtained via thermally induced, reversible magnetic transition during the heating and cooling cycles, achieving the harvest of low-grade waste heat; besides, the results showed that the induced I depended not only on dM/dT but also on dT/dt. The intrinsic TMG performance of all the target materials were compared comprehensively by eliminating the influence of different TC locations. Among them, the La(Fe, Si)13Hy/In composite exhibited the highest induced current I (9.12 μA g−1) and power density (0.47 mW m−3); in particular, its investment cost index was 1–2 orders of magnitude higher than those of the other materials. Thus, this work demonstrates that the La(Fe, Si)13Hy/In composite is a promising TMG material for harvesting low-grade waste heat.

In this paper, we consider a variation of the classic dominating set problem - The Two Disjoint Connected Dominating Sets (DCDS) problem, which finds applications in many real domains including wireless sensor networks. In the DCDS problem, we are given a graph G = ( V , E ) and required to find a new edge set E′ with minimum cardinality such that the resulting new graph after the adding of E′ has a pair of disjoint connected dominating sets. This problem is very hard in general graphs, and we show that it is NP -hard even restricted to trees. We also present a polynomial time approximation algorithm for the DCDS problem for arbitrary trees with performance ratio 3 2 asymptotically.

In multi-criteria decision-making (MCDM) methods, the rank reversal is a highly important problem for analyzing the reliability of MCDM methods. The main objective of this paper is to analyze and precisely predict the occurrence of rank reversal in the ELECTRE II method. First, some useful properties of the optimal alternatives are obtained in the descending and ascending distillation processes. Second, two new concepts named combination relation digraph and numerator matrix are proposed to precisely analyze and greatly simplify the rank reversal in the ELECTRE II method. Third, all the reasons for the rank reversal in the ELECTRE II method are revealed more completely. Fourth, the necessary and sufficient conditions are proposed for determining whether or not the rank reversal occurs in the ELECTRE II method. Additionally, the proposed methods in this paper are valid for analyzing the rank reversal in the ELECTRE method with discriminating thresholds. Finally, five examples are used to evaluate the correctness and effectiveness of the methods that are proposed in this paper.

Neurogenesis in the subventricular zone (SVZ) plays a vital role in neurologic recovery after stroke. However, only a small fraction of newly generated neuroblasts from the SVZ will survive long-term. Successful migration and survival of neuroblasts requires angiogenesis, lesion-derived chemo-attractants, and appropriate local microenvironments, which are partly regulated by the platelet-derived growth factor receptor (PDGFR) signaling pathway. In this study, we investigated the effects of PDGFR inhibition in a mouse model of transient middle cerebral artery occlusion (MCAO). We blocked the pathway using a nonselective PDGFR inhibitor, crenolanib, during the acute post-MCAO phase (days 1-3) or during the sub-acute phase (days 7-9). Downregulating the PDGFR signaling pathway with crenolanib from day 1 to day 3 after MCAO significantly decreased the migration of neuroblasts from the SVZ to the peri-infarct region, decreased angiogenesis, and lowered expression of vascular endothelial growth factor, stromal cell-derived factor-1, and monocyte chemotactic protein-1. Downregulation of the PDGFR signaling pathway on days 7-9 with crenolanib significantly increased apoptosis of the neuroblasts that had migrated to the peri-infarct region, increased the number of activated microglia, and decreased the expression of brain-derived neurotrophic factor, neurotrophin-3, and interleukin-10. Crenolanib treatment increased the apoptosis of pericytes and decreased the pericyte/vascular coverage, but had no effects on apoptosis of astrocytes. We conclude that the PDGFR signaling pathway plays a vital role in the SVZ neurogenesis after stroke. It can also affect angiogenesis, lesion-derived chemo-attractants, and the local microenvironment, which are all important to stroke-induced neurogenesis.

Choline acetyltransferase-positive (ChAT+) neurons within the subventricular zone (SVZ) have been shown to promote neurogenesis after stroke in mice by secreting acetylcholine (ACh); however, the mechanisms remain unclear. Receptors known to bind ACh include the nicotinic ACh receptors (nAChRs), which are present in the SVZ and have been shown to be important for cell proliferation, differentiation, and survival. In this study, we investigated the neurogenic role of the alpha-7 nAChR (α7 nAChR) in a mouse model of middle cerebral artery occlusion (MCAO) by using α7 nAChR inhibitor methyllycaconitine. Mice subjected to MCAO exhibited elevated expression of cytomembrane and nuclear fibroblast growth factor receptor 1 (FGFR1), as well as increased expression of PI3K, pAkt, doublecortin (DCX), polysialylated - neuronal cell adhesion molecule (PSA-NCAM), and mammalian achaete-scute homolog 1 (Mash1). MCAO mice also had more glial fibrillary acidic protein (GFAP)/5-bromo-2′-deoxyuridine (BrdU)-positive cells and DCX-positive cells in the SVZ than did the sham-operated group. Methyllycaconitine treatment increased cytomembrane FGFR1 expression and GFAP/BrdU-positive cells, upregulated the levels of phosphoinositide 3-kinase (PI3K) and phospho-Akt (pAkt), decreased nuclear FGFR1 expression, decreased the number of DCX-positive cells, and reduced the levels of DCX, PSA-NCAM, and Mash1 in the SVZ of MCAO mice compared with levels in vehicle-treated MCAO mice. MCAO mice treated with α7 nAChR agonist PNU-282987 exhibited the opposite effects. Our data show that α7 nAChR may decrease the proliferation of neural stem cells and promote differentiation of existing neural stem cells after stroke. These results identify a new mechanism of SVZ ChAT+ neuron-induced neurogenesis.

Teriflunomide has been reported to inhibit microglial activation in experimental models of traumatic brain injury. However, its roles in ischemic stroke and underlying mechanisms of action are still undiscovered. In this study, we investigated the effects of teriflunomide on brain edema, neurologic deficits, infarct volume, neuroinflammation, blood-brain barrier (BBB) permeability, and neurogenesis in a mouse model of transient middle cerebral artery occlusion (tMCAO). tMCAO mice treated with teriflunomide showed lower brain water content on day 3, milder neurologic deficits and smaller infarct volume on day 7 than those treated with vehicle. Additionally, mice received teriflunomide had fewer activated Iba-1-positive microglia and lower protein levels of interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), and 3-Nitrotyrosine (3-NT) compared with those received vehicle on day 3. Further, teriflunomide alleviated Evans blue dye leakage, increased pericyte coverage and protein levels of platelet-derived growth factor B (PDGFB), platelet-derived growth factor receptor β (PDGFRβ) and Bcl2, and decreased the number of PDGFRβ/matrix metalloproteinase 9 (MMP9)-positive cells. Moreover, teriflunomide reduced the loss of zonula occludens-1 (ZO-1) and occludin. Finally, teriflunomide significantly upregulated the number of 5-bromo-20-deoxyuridine (BrdU)/doublecortin (DCX)-positive cells and expression of mammalian achaete-scute homolog 1 (Mash1), DCX and Pbx1 in subventricular zone (SVZ) on day 7 after stroke. Our results indicate that teriflunomide exhibits protective roles in ischemic stroke by inhibiting neuroinflammation, alleviating BBB disruption and enhancing neurogenesis.

Resistance associated substitutions (RASs) can reduce the efficacy of direct-acting antiviral agents (DAAs) targeting hepatitis C virus (HCV) and lead to treatment failure. Clinical data of HCV NS5A RASs prevalence are limited in China and need to be investigated. A total of 878 unique patient samples with different genotypes (GT) (1b: n = 489, 2a: n = 203, 3a: n = 60, 3b: n = 78, 6a: n = 48) were collected from around mainland China by KingMed Laboratory and analyzed for NS5A RASs distribution by Sanger sequencing. Phylogeographic analyses based on NS5A domain 1 sequences indicated circulation of both locally and nationally epidemic strains. Relatively high frequency of Y93H (14.1%) was only detected in GT1b but not in other subtypes. High frequency of L31M was found in both GT2a (95.6%) and GT3b (98.7%) sequences. Due to the overlapping incidence of A30K, 96% of GT3b isolates had NS5A RASs combination A30K + L31M, which confers high levels of resistance to most NS5A inhibitors. No RASs were detected in GT6a strains. Meanwhile, baseline NS5A RASs fingerprints were also evaluated in 185 DAA treatment-naive GT1b patients with next generation sequencing method. Patients presenting with Y93H had statistically higher entropy of HCV NS5A sequences. Taken together, subtype-specific distribution patterns of NS5A RASs were observed. GT1b patients with higher HCV complexity tend to have a greater chance of Y93H presence, while GT3b patients are naturally resistant to current NS5A inhibitors and their treatment may pose a challenge to real-world DAA application.

In the t -Latency-Bounded Target Set Selection ( t -LBTSS) problem, we are given a simple graph G = ( V , E ) , a certain latency bound t and a threshold function ? ( v ) = ? ? d ( v ) ? for every vertex v of G , where 0 < ? < 1 is a rational number and d ( v ) is the degree of v in V , the goal is to find a target set S with smallest cardinality such that all vertices in V are activated by S by a so called "diffusion process" within t rounds as follows: Initially, all vertices in the target set become activate. Then at each step i of the process, each vertex get activated if the number of active vertices in its neighbor after i - 1 exceeds its threshold.For general graphs, the t -LBTSS problem is not only NP-hard, it is also hard to be approximated by Chen's inapproachability results (Chen, 2009). In this paper, we are interested in finding an optimal target set for some special family of graphs. A simple, tight but nontrivial inequality was presented which gives the lower bound of the total sum of degrees in a feasible target set to t -LBTSS problem, in terms of the number of edges in the graph. Necessary and sufficient conditions for equality to hold have been established, based on which we are able to construct families of infinite number of graphs for which the optimal solution to t -LBTSS problem become obvious. In particular, we gave an exact formula for the optimal solution of a kind of toroidal mesh graphs, while it seems difficult to tell what the optimal solutions are for these graphs without using the equality given in the paper.

As a variant of minimum connected dominating set problem, two disjoint connected dominating sets (DCDS) problem is to ask whether there are two DCDS [Formula: see text] in a connected graph [Formula: see text] with [Formula: see text] and [Formula: see text], and if not, how to add an edge subset with minimum cardinality such that the new graph has a pair of DCDS. The two DCDS problem is so hard that it is NP-hard on trees. In this paper, if the vertex set [Formula: see text] of a connected graph [Formula: see text] can be partitioned into two DCDS of [Formula: see text], then it is called a DCDS graph. First, a necessary but not sufficient condition is proposed for cubic (3-regular) graph to be a DCDS graph. To be exact, if a cubic graph is a DCDS graph, there are at most four disjoint triangles in it. Next, if a connected graph [Formula: see text] is a DCDS graph, a simple but nontrivial upper bound [Formula: see text] of the girth [Formula: see text] is presented.

Background At low levels, carbon monoxide (CO) has been shown to have beneficial effects on multiple organs and tissues through its potential anti-inflammatory, anti-apoptotic, and anti-proliferative properties. However, the effect of CO-releasing molecule (CORM)-3, a water-soluble CORM, on ischemic stroke and its mechanism of action are still unclear. Methods We investigated the role of CORM-3 in the mouse model of transient middle cerebral artery occlusion (tMCAO). CORM-3 or saline was administered to mice by retro-orbital injection at the time of reperfusion after 1-h tMCAO or at 1 h after sham surgery. We assessed infarct volume and brain water content at 24 and 72 h after ischemia, blood-brain barrier permeability at 6 and 72 h after ischemia, and neurologic deficits on days 1, 3, 7, and 14. Results Among mice that underwent tMCAO, those that received CORM-3 had significantly smaller infarct volume and greater expression of neuronal nuclear antigen (NeuN) and microtubule-associated protein 2 than did saline-treated mice. CORM-3-treated mice had significantly fewer activated microglia in the peri-infarction zone than did control mice and exhibited downregulated expression of ionized calcium-binding adapter molecule (Iba)-1, tumor necrosis factor-α, and interleukin 1β. CORM-3-treated mice had significantly lower brain water content and enhanced neurologic outcomes on days 3, 7, and 14 post-tMCAO. Lastly, CORM-3 treatment reduced Evans blue leakage; increased expression of platelet-derived growth factor receptor-β, tight junction protein ZO-1, and matrix protein laminin; and decreased protein level of matrix metalloproteinase-9. Conclusion CORM-3 treatment at the time of reperfusion reduces ischemia-reperfusion-induced brain injury by suppressing neuroinflammation and alleviating blood-brain barrier disruption. Our data suggest that CORM-3 may provide an effective therapy for ischemic stroke.

The idea of virtual backbone has emerged to improve the efficiency of flooding based routing algorithms for wireless networks. The effectiveness of virtual backbone can be improved as its size decreases. The minimum connected dominating set (CDS) problem was used to compute minimum size virtual backbone. However, as this formulation requires the virtual backbone nodes to connect all other nodes, even the size of minimum virtual backbone can be large. This observation leads to consider the minimum partial CDS problem, whose goal is to compute a CDS serving only more than a certain portion of the nodes in a given network. So far, the performance ratio of the best approximation algorithm for the problem is $$O(\ln \varDelta ),$$O(lnΔ), where $$\varDelta$$Δ is the maximum degree of the input general graph. In this paper, we first assume the input graph is a growth-bounded graph and introduce the first constant factor approximation for the problem. Later, we show that our algorithm is an approximation for the problem in unit disk graph with a much smaller performance ratio, which is of practical interest since unit disk graph is popular to abstract homogeneous wireless networks. Finally, we conduct simulations to evaluate the average performance of our algorithm.

Purpose To avoid the nursing risk of inpatients, reduce the occurrence of nursing errors and improve the safety of inpatients. Methods We established a nursing risk early warning and control system, which includes a safety supervisory network, risk screening and early warning tools, and a risk control process. Results The qualified rates of risk control measures to prevent pressure ulcers, unplanned extubation and fall/fall from bed all increased. The incidence of reported nursing errors decreased. The number of mistakes in medication-giving decreased. Conclusion The establishment of an inpatient early warning and control system could effectively avoid nursing risk, improve risk prevention abilities, improve patient safety, and improve nursing quality.

Background Cancer pain management is still unsatisfactory, although some effective guidelines exist. Educational interventions are reported to be useful in pain relief for oncology outpatients. Aim The aims of this systematic review were to evaluate the effects of nurse-led educational interventions on improving cancer pain outcomes for oncology patients, and to establish an effective cancer pain protocol for clinical nursing practice in China. Methods A three-step search strategy was utilized. Eight databases were searched using the standards provided by the Joanna Briggs Institute that guided article selection, critical appraisal, data collection and data synthesis. Results A total of 1093 studies were identified through a literature search. Only six studies complied with the inclusion criteria and were found to be methodologically sound. In general, the included studies indicated positive results pertaining to patient's knowledge and attitudes towards analgesics and cancer pain management and decreased pain intensity. Studies reported minimal effects of intervention on anxiety, depression, satisfaction regarding cancer pain management and patient's quality of life. Conclusions Educational interventions were reported as effective methods to improve cancer pain outcomes. Analysis of the six included studies demonstrated the overall positive effects of nurse-led educational interventions for improving cancer pain management. Implications for nursing and health policy The results suggest that an effective cancer pain protocol for improving cancer pain management can be established in China.

In the Minimum Weight Partial Connected Set Cover problem, we are given a finite ground set $$U$$U, an integer $$q\le |U|$$q≤|U|, a collection $$\mathcal {E}$$E of subsets of $$U$$U, and a connected graph $$G_{\mathcal {E}}$$GE on vertex set $$\mathcal {E}$$E, the goal is to find a minimum weight subcollection of $$\mathcal {E}$$E which covers at least $$q$$q elements of $$U$$U and induces a connected subgraph in $$G_{\mathcal {E}}$$GE. In this paper, we derive a "partial cover property" for the greedy solution of the Minimum Weight Set Cover problem, based on which we present (a) for the weighted version under the assumption that any pair of sets in $$\mathcal {E}$$E with nonempty intersection are adjacent in $$G_{\mathcal {E}}$$GE (the Minimum Weight Partial Connected Vertex Cover problem falls into this range), an approximation algorithm with performance ratio $$\rho (1+H(\gamma ))+o(1)$$?(1+H(?))+o(1), and (b) for the cardinality version under the assumption that any pair of sets in $$\mathcal {E}$$E with nonempty intersection are at most $$d$$d-hops away from each other (the Minimum Partial Connected $$k$$k-Hop Dominating Set problem falls into this range), an approximation algorithm with performance ratio $$2(1+dH(\gamma ))+o(1)$$2(1+dH(?))+o(1), where $$\gamma =\max \{|X|:X\in \mathcal {E}\}$$?=max{|X|:X?E}, $$H(\cdot )$$H(·) is the Harmonic number, and $$\rho $$? is the performance ratio for the Minimum Quota Node-Weighted Steiner Tree problem.

In this study, the ranges of criteria weights based on the outranking relations in ELECTRE I and II methods are analyzed, which is considered as the sensitivity analysis regarding criteria weights. First, an important theorem is proved, in which the maximum value of discordance indices for any two alternatives is shown to be equal to 1. Using this theorem, four situations of outranking relations for any two alternatives are simplified to two situations when sensitivity analysis of criteria weights is performed for ELECTRE I. Subsequently, some inequalities are obtained to calculate the ranges of criteria weights when keeping the outranking relations between any two alternatives unchanged. For ELECTRE II, nine situations of strong and weak outranking relations are simplified into three situations of relations according to this theorem. The ranges of criteria weights are also derived when the strong and weak outranking relations remain unchanged. Finally, two examples are presented to test and verify the effectiveness of the sensitivity analysis of criteria weights for ELECTRE I. Two analogous examples are also presented in ELECTRE II.

Neuroinflammation crucially influences functional recovery after ischemic stroke. Wnt-3a, a novel Wnt protein that specifically promotes Wnt/β-catenin signaling pathway, has been shown to regulate apoptosis and cell proliferation, but how it affects ischemic stroke-induced toxic brain inflammation remains unknown. Using a transient middle cerebral artery occlusion (tMCAO) mouse model in this study, we found that intranasal Wnt-3a-treated tMCAO mice had apparently reduced infarct volume and decreased brain water content after being allowed to recover for 72 h, as well as better neurologic outcomes on days 3, 7, and 14. Mice received Wnt-3a had significantly fewer tMCAO-induced peri-infarct TUNEL-positive cells compared with those received vehicle. Further, Wnt-3a-delivered tMCAO mice had notably fewer peri-infarct CD68-positive cells and lower ionized calcium-binding adapter molecule (Iba)-1 protein level. Wnt-3a significantly downregulated the expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor (TNF)-α, and upregulated the expression of arginase 1 (Arg1) and CD206. Finally, Wnt-3a obviously decreased the number of tMCAO-induced peri-infarct glial fibrillary acidic protein (GFAP)/C3-positive cells, increased the number of GFAP/S100A10-positive cells, attenuated the protein levels of GFAP and interleukin 15 (IL15), and elevated IL33 protein level. Our findings suggest that intranasal Wnt-3a could ameliorate toxic responses of microglia/macrophages and astrocytes in ischemic brain injury, supporting that Wnt-3a might be potentially appropriate for ischemic stroke treatment functioning as an immunomodulatory agent.

materials are fashioned from ‘artifi cial atoms’, which are engineered to yield a specifi c response to the electric and magnetic components of light, the properties of which are preserved in a macroscopic medium fabricated from their individual units. Electromagnetic properties achieved by metamaterials derive from the geometry of their unit cells, as opposed to the bandstructure of their makeup. Metamaterials are thus a bottom-up design paradigm for the construction of advanced materials and hold great potential for applications spanning the electromagnetic spectrum. Although metamaterial have realized novel electromagnetic properties, some which have been diffi cult to achieve with natural materials, the ability to dynamically control these responses in real-time would offer signifi cant advantages enabling metamaterials to transition into state-of-the-art devices.

The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also their promise for applications. A particular branch-the metamaterial perfect absorber (MPA)-has garnered interest due to the fact that it can achieve unity absorptivity of electromagnetic waves. Since its first experimental demonstration in 2008, the MPA has progressed significantly with designs shown across the electromagnetic spectrum, from microwave to optical. In this Progress Report we give an overview of the field and discuss a selection of examples and related applications. The ability of the MPA to exhibit extreme performance flexibility will be discussed and the theory underlying their operation and limitations will be established. Insight is given into what we can expect from this rapidly expanding field and future challenges will be addressed.

In the Minimum k-Path Connected Vertex Cover Problem (MkPCVCP), we are given a connected graph G and an integer k ? 2, and are required to find a subset C of vertices with minimum cardinality such that each path with length k ? 1 has a vertex in C, and moreover, the induced subgraph G[C] is connected. MkPCVCP is a generalization of the minimum connected vertex cover problem and has applications in many areas such as security communications in wireless sensor networks. MkPCVCP is proved to be NP-complete. In this paper, we give the first polynomial time approximation scheme (PTAS) for MkPCVCP in unit disk graphs, for every fixed k ? 2.

The possibility of temporally and spatially coherent thermal emission has been demonstrated utilizing stacked gratings. We demonstrate that the metallic grating with narrow air slit behaves like a homogeneous slab with large permittivity and small permeability and find that the interaction between the metallic grating and the Bragg grating gives rise to impendence matching at wavelengths located in the photonic band gap of the Bragg grating, which enables the stacked gratings to perform high emission with ultranarrow spectrum and antenna-like spatial response. This paves the way towards the design of a novel infrared source platform for applications such as thermal analysis, imaging, security, biosensing, and medical diagnoses.

Metamaterial absorbers have been demonstrated across much of the electromagnetic spectrum and exhibit both broad and narrow-band absorption for normally incident radiation. Absorption diminishes for increasing angles of incidence and transverse electric polarization falls off much more rapidly than transverse magnetic. We unambiguously demonstrate that broad-angle TM behavior cannot be associated with periodicity, but rather is due to coupling with a surface electromagnetic mode that is both supported by, and well described via the effective optical constants of the metamaterial where we achieve a resonant wavelength that is 19.1 times larger than the unit cell. Experimental results are supported by simulations and we highlight the potential to modify the angular response of absorbers by tailoring the surface wave.

In this Letter we demonstrate, for the first time, selective thermal emitters based on metamaterial perfect absorbers. We experimentally realize a narrow band midinfrared (MIR) thermal emitter. Multiple metamaterial sublattices further permit construction of a dual-band MIR emitter. By performing both emissivity and absorptivity measurements, we find that emissivity and absorptivity agree very well as predicted by Kirchhoff's law of thermal radiation. Our results directly demonstrate the great flexibility of metamaterials for tailoring blackbody emission.

We demonstrate, for the first time, a spatially dependent metamaterial perfect absorber operating in the infrared regime. We achieve an experimental absorption of 97% at a wavelength of 6.0 microns, and our results agree well with numerical full-wave simulations. By using two different metamaterial sublattices we experimentally demonstrate a spatial and frequency varying absorption which may have many relevant applications including hyperspectral sub-sampling imaging.

We present novel metamaterial structures based upon various planar wallpaper groups, in both hexagonal and square unit cells. An investigation of metamaterials consisting of one, two, and three unique sub-lattices with resonant frequencies in the terahertz (THz) was performed. We describe the theory, and perform simulations and experiments to characterize these multiple element metamaterials. A method for using these new structures as a means for bio / chemical hazard detection, as well as electromagnetic signature control is proposed., Comment: 11 pages, 5 figures

Unsteady incompressible flowing N-S equation, RNG k − ɛ turbulence model, and VOF (Volume of Fluid) method have been adopted to numerically simulate the flow structure of two-jet with varying spacing on a plunge pool, with reference to the Xiluodu double curvature arch dam. The variable law of time average flow energy and dissipating rate of two-jet with different spacing shooting into a plunge pool have been computed and analyzed. The results show that for the two-jet into a plunge pool, flow energy is mostly used up at submerged jetting section, the change of jet flow spacing produces a little influence on the time average energy dissipating rate of the upstream flow, whereas, big influence on that of the downstream flow, the smaller jet spacing is, the larger the energy dissipating rate of the downstream flow will be. Therefore, if the flow is discharged from a dam in layers, after satisfying the requirements of fully functioning of hydrodynamic cushion, relatively small jet spacing shall be adopted as it can be to further raise time average energy dissipating rate at submerged jetting section. This study can offer reference to the optimum design of a plunge pool and appreciate layout of a dam outlets.

In this letter, we discuss the design, fabrication, and experimental characterization of a bi-layer fully functional near-perfect metamaterial absorber (MMA) in the long-wavelength infrared (LWIR), which is broadband and generally insensitive to polarization up to a 60° incidence angle. A spectral absorptance of ≥99% was attained simultaneously at multiple LWIR wavelengths, with a bandwidth of 2 μm where the absorptance is ≥90%. This remarkable behavior is attributed to the strong mixing of coupling modes between the two resonators and the ground plane in the presence of a lossy dielectric, in which single layer structures do not exhibit. Furthermore, we show, by comparing two different MMA structures, how the absorption can be tailored by design within and across several IR subdivisions through a slight change in geometrical parameters. The bi-layer MMA has the immediate application of a functionally versatile, low-profile thermal sensor or emitter.

High absorption efficiency is particularly desirable at present for various microtechnological applications including microbolometers, photodectors, coherent thermal emitters, and solar cells. Here we report the design, characterization, and experimental demonstration of an ultrathin, wide-angle, subwavelength high performance metamaterial absorber for optical frequencies. Experimental results show that an absorption peak of 88% is achieved at the wavelength of ∼1.58 μm, though theoretical results give near perfect absorption.