bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perfect Matchings of Regular Bipartite Graphs
Authors: Lukot'ka Robert , Rollová Edita 
Published: September 2016

AbstractLet G be a regular bipartite graph and . We show that there exist perfect matchings of G containing both, an odd and an even number of edges from X if and only if the signed graph , that is a graph G with exactly the edges from X being negative, is not equivalent to . In fact, we prove that for a given signed regular bipartite graph with minimum signature, it is possible to find perfect matchings that contain exactly no negative edges or an arbitrary one preselected negative edge. Moreover, if the underlying graph is cubic, there exists a perfect matching with exactly two preselected negative edges. As an application of our results we show that each signed regular bipartite graph that contains an unbalanced circuit has a 2‐cycle‐cover such that each cycle contains an odd number of negative edges.
Simultaneous multi‐slice (SMS) acquisition enhances the sensitivity of hemodynamic mapping using gas challenges
Authors: Ravi Harshan , Liu Peiying , Peng Shin‐Lei , Liu Hanli , Lu Hanzhang 
Published: September 2016

Hemodynamic mapping using gas inhalation has received increasing interest in recent years. Cerebrovascular reactivity (CVR), which reflects the ability of the brain vasculature to dilate in response to a vasoactive stimulus, can be measured by CO2 inhalation with continuous acquisition of blood oxygen level‐dependent (BOLD) magnetic resonance images. Cerebral blood volume (CBV) can be measured by O2 inhalation. These hemodynamic mapping methods are appealing because of their absence of gadolinium contrast agent, their ability to assess both baseline perfusion and vascular reserve, and their utility in calibrating the functional magnetic resonance imaging (fMRI) signal. However, like other functional and physiological indices, a major drawback of these measurements is their poor sensitivity and reliability. Simultaneous multi‐slice echo planar imaging (SMS EPI) is a fast imaging technology that allows the excitation and acquisition of multiple two‐dimensional slices simultaneously, and has been shown to enhance the sensitivity of several MRI applications. To our knowledge, the benefit of SMS in gas inhalation imaging has not been investigated. In this work, we compared the sensitivity of CO2 and O2 inhalation data collected using SMS factor 2 (SMS2) and SMS factor 3 (SMS3) with those collected using conventional EPI (SMS1). We showed that the sensitivity of SMS scans was significantly (p = 0.01) higher than that of conventional EPI, although no difference was found between SMS2 and SMS3 (p = 0.3). On a voxel‐wise level, approximately 20–30% of voxels in the brain showed a significant enhancement in sensitivity when using SMS compared with conventional EPI, with other voxels showing an increase, but not reaching statistical significance. When using SMS, the scan duration can be reduced by half, whilst maintaining the sensitivity of conventional EPI. The availability of a sensitive acquisition technique can further enhance the potential of gas inhalation MRI in clinical applications.
Reduced respiratory motion artifacts using structural similarity in fast 2D dynamic contrast enhanced MRI of liver lesions
Authors: ter Voert Edwin E.G.W. , Heijmen Linda , Punt Cornelis J.A. , de Wilt Johannes H.W. , van Laarhoven Hanneke W.M. , Heerschap Arend 
Published: September 2016

The purpose of this work was to improve dynamic contrast enhanced MRI (DCE‐MRI) of liver lesions by removing motion corrupted images as identified by a structural similarity (SSIM) algorithm, and to assess the effect of this correction on the pharmacokinetic parameter Ktrans using automatically determined arterial input functions (AIFs).Fifteen patients with colorectal liver metastases were measured twice with a T1 weighted multislice 2D FLASH sequence for DCE‐MRI (time resolution 1.2 s). AIFs were automatically derived from contrast inflow in the aorta of each patient. Thereafter, SSIM identified motion corrupted images of the liver were removed from the DCE dataset. From this corrected data set Ktrans and its reproducibility were determined.Using the SSIM algorithm a median fraction of 46% (range 37–50%) of the liver images in DCE time series was labeled as motion distorted. Rejection of these images resulted in a significantly lower median Ktrans (p < 0.05) and lower coefficient of repeatability of Ktrans in liver metastases compared with an analysis without correction.SSIM correction improves the reproducibility of the DCE‐MRI parameter Ktrans in liver metastasis and reduces contamination of Ktrans values of lesions by that of surrounding normal liver tissue.
Outcome of fetal gastro‐intestinal cysts: a systematic review and meta‐analysis
Authors: Marrone Luisa , Liberati Marco , Khalil Asma , Rizzo Giuseppe , Leombroni Martina , Buca Danilo , Bascietto Francesca , Gustapane Sarah , Flacco Maria Elena , Manzoli Lamberto , Acharya Ganesh , D'Antonio Francesco 
Published: September 2016

AbstractObjectivesTo explore the outcome of fetal gastrointestinal (GI) cysts and to ascertain the detection rate of prenatal ultrasound in identifying these anomalies.MethodsMedline and Embase databases were searched. The outcomes explored were: resolution of the cyst, additional GI anomalies detected only at birth, clinical symptoms, need for surgery, post‐surgical complications and diagnostic accuracy. Meta‐analyses of proportions and hierarchical summary receiver operating characteristics (HSROC) model were used to analyse the data.ResultsTen studies were included; 27.0% (95% CI 2.6–64.4) of the cysts resolved either pre or post‐natally. Additional GI anomalies were detected in 6.0% (95% CI 1.1–14.7). Clinical symptoms occurred in 31.1% (95% CI 14.9–50.2), while 50.6% (95% CI 10.0–90.8) had surgery. Post‐surgical complications occurred in 6.1% (95% CI 0.2–19.6). Overall detection rate of prenatal ultrasound in correctly identifying GI cysts was good (sensitivity: 94.5%, 95% CI: 39.1–99.8; specificity: 97.7%, 95% CI 89.9–99.5).ConclusionGI cysts are usually benign. Clinical symptoms occur in approximately one third of children. About one third of the cysts resolves, while the rate of complications after surgery is low. Prenatal ultrasound has an overall good diagnostic accuracy in identifying these anomalies. © 2016 John Wiley & Sons, Ltd.
Structural studies on KijD1, a sugar C‐3′‐methyltransferase
Authors: Dow Garrett T. , Thoden James B. , Holden Hazel M. 
Published: September 2016

AbstractKijanimicin is an antitumor antibiotic isolated from Actinomadura kijaniata. It is composed of three distinct moieties: a pentacyclic core, a monosaccharide referred to as d‐kijanose, and a tetrasaccharide chain composed of l‐digitoxose units. d‐Kijanose is a highly unusual nitro‐containing tetradeoxysugar, which requires at least ten enzymes for its production. Here we describe a structural analysis of one of these enzymes, namely KijD1, which functions as a C‐3′‐methyltransferase using S‐adenosylmethionine as its cofactor. For this investigation, two ternary complexes of KijD1, determined in the presence of S‐adenosylhomocysteine (SAH) and dTDP or SAH and dTDP‐3‐amino‐2,3,6‐trideoxy‐4‐keto‐3‐methyl‐d‐glucose, were solved to 1.7 or 1.6 Å resolution, respectively. Unexpectedly, these structures, as well as additional biochemical analyses, demonstrated that the quaternary structure of KijD1 is a dimer. Indeed, this is in sharp contrast to that previously observed for the sugar C‐3′‐methyltransferase isolated from Micromonospora chalcea. By the judicious use of site‐directed mutagenesis, it was possible to convert the dimeric form of KijD1 into a monomeric version. The quaternary structure of KijD1 could not have been deduced based solely on bioinformatics approaches, and thus this investigation highlights the continuing need for experimental validation.
On martingale tail sums for the path length in random trees
Authors: Sulzbach Henning 
Published: September 2016

AbstractFor a martingale (Xn) converging almost surely to a random variable X, the sequence (Xn– X) is called martingale tail sum. Recently, Neininger (Random Structures Algorithms 46 (2015), 346–361) proved a central limit theorem for the martingale tail sum of Régnier's martingale for the path length in random binary search trees. Grübel and Kabluchko (in press) gave an alternative proof also conjecturing a corresponding law of the iterated logarithm. We prove the central limit theorem with convergence of higher moments and the law of the iterated logarithm for a family of trees containing binary search trees, recursive trees and plane‐oriented recursive trees. © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 50, 493–508, 2017
Slack resources, firm performance, and the institutional context: Evidence from privately held European firms
Authors: Vanacker Tom , Collewaert Veroniek , Zahra Shaker A. 
Published: September 2016

Research summary: Integrating the behavioral and institutional perspectives, we propose that a country's formal institutions, particularly its legal frameworks, affect managers' deployment of slack resources. Specifically, we explore the moderating effects of creditor and employee rights on the performance effects of slack. Using longitudinal data from 162,633 European private firms in 26 countries, we find that financial slack enhances firm performance at diminishing rates, whereas human resource (HR) slack lowers performance at diminishing rates. However, financial slack has a more positive effect on firm performance in countries with weaker creditor rights, whereas HR slack has a more negative effect on performance in countries with stronger employee rights. The results provide a richer view of the relationship between slack and firm performance than currently assumed in the literature.Managerial summary: A key dilemma managers often encounter is whether, on the one hand, they should build in excess resources to buffer their firms from internal and external shocks and to pursue new opportunities or whether, on the other hand, they should develop “lean” firms. Our study suggests that excess cash resources—which are usually viewed as easy to redeploy—benefit firm performance, especially when firms operate in countries with weaker creditor rights. However, excess human resources—which are usually viewed as more difficult to redeploy—hamper firm performance, particularly when firms operate in countries with stronger labor protection laws. Thus, the management of slack resources critically depends on the characteristics of these resources (e.g., redeployability) and the institutional context in which managers operate. Copyright © 2016 John Wiley & Sons, Ltd.
Performance‐based durability design, carbonation, part 3: PSF approach and a proposal for the revision of deemed‐to‐satisfy rules
Authors: von Greve‐Dierfeld Stefanie , Gehlen Christoph 
Published: September 2016

AbstractA performance‐based safety factor durability design format is proposed and developed with respect to carbonation of concrete. Deemed‐to‐satisfy rules based on a partial safety factor design approach are developed for the carbonation of concrete. This design format follows the design procedure proposed in EN 1990 [1]. For the design format, the limit state equation for the carbonation is introduced in its probabilistic and safety factor format. The PSF approach has been used to derive design charts. Values for minimum concrete cover depending on material resistance and exposure class are proposed for critical environmental conditions and a design service life of 50 years.
Fensterbierscheiben in the Pena National Palace collection – chemical and iconographic relations
Authors: Coutinho I. , Berger F. , Rodrigues A. , Coutinho M. L. , Machado A. , Alves Luis C. , Vilarigues M. 
Published: September 2016

The stained‐glass collection from the Pena National Palace (Sintra, Portugal) includes around 130 ‘rural panels’, also known as Fensterbierscheiben, that were produced between the 16th and 19th centuries. The aim of this investigation is to characterise the glass composition of this collection of Fensterbierscheiben and relate it with the iconographic research made on these panels, in order to establish possible provenance of production. This is the first study on Fensterbierscheiben, where the chemical information of the glass is considered and related with historical information.The micro‐energy dispersive X‐ray fluorescence allowed performing non‐invasive analysis, mostly performed in situ. Micro‐particle‐induced X‐ray emission analysis was performed on the cross section of a small group of fragmented panels for obtaining quantitative chemical composition of the glass. Through the analysis of the colourless glass, and the comparison of micro‐energy dispersive X‐ray fluorescence and micro‐particle‐induced X‐ray emission data, it was concluded that the majority of the panes have a high lime low alkali glass composition. Furthermore, the Fensterbierscheiben panes form a cohesive group in terms of composition, suggesting that they were all manufactured with raw materials from the same region. This study also allowed one to observe the chronological evolution in terms of treatments applied to the used raw materials. Copyright © 2016 John Wiley & Sons, Ltd.
Treatment Access and Survival Amongst British Asians with Pancreatic Cancer
Authors: Isherwood J. , Bilku D. , Metcalfe M. S. , Dennison A. R. , Garcea G. 
Published: September 2016

AbstractIntroductionDespite increasingly mixed communities in large cities, there remains a paucity of absolute and comparative data concerning the treatment, access and survival of British Asians with pancreatic cancer.MethodsA prospective database of 1038 patients with a diagnosis of pancreatic cancer from 2003 to 2012 was analysed. Asian/Asian British was defined as patients identifying themselves as originating from India, Bangladesh or Pakistan.ResultsNo significant difference was observed in gender split for both Asian/Asian British and White British (AAB and WB). The incidence of pancreas cancer was also equivalent between the two groups at 8.1 versus 8.8 per 100,000 of the population. Age at presentation was significantly younger in AABs when compared to WBs (67 vs. 70 years, p = 0.003). Whilst median maximal tumour diameter, node status and the incidence of metastases were not different between AABs and WBs, the AABs had a significantly greater median T‐stage (3.0 versus 2.5, p = 0.0024). The percentage of patients referred for chemotherapy was significantly higher in the AAB group (70.5 vs. 47.7 %, p = 0.0015). Overall survival and survival for patients having palliative treatment were significantly greater in AABs (4.6 vs. 6.1 months and 3.7 vs. 5.1 months).ConclusionThis study demonstrates that AAB patients are present with pancreatic cancer at a younger age and that when receiving palliative chemotherapy their survival is significantly better. Further studies and larger data sets over a longer period are required. It is important to examine further the complexity of incidence and survival in ethnic minorities and investigate the underlying reasons when differences are demonstrated.
Mice with a heterozygous Lrp6 deletion have impaired fracture healing
Authors: Burgers Travis A , Vivanco Juan F , Zahatnansky Juraj , Moren Andrew J Vander , Mason James J , Williams Bart O 
Published: September 2016

AbstractBone fracture non-unions, the failure of a fracture to heal, occur in 10%–20% of fractures and are a costly and debilitating clinical problem. The Wnt/β-catenin pathway is critical in bone development and fracture healing. Polymorphisms of linking low-density lipoprotein receptor-related protein 6 (LRP6), a Wnt-binding receptor, have been associated with decreased bone mineral density and fragility fractures, although this remains controversial. Mice with a homozygous deletion of Lrp6 have severe skeletal abnormalities and are not viable, whereas mice with a heterozygous deletion have a combinatory effect with Lrp5 to decrease bone mineral density. As fracture healing closely models embryonic skeletal development, we investigated the process of fracture healing in mice heterozygous for Lrp6 (Lrp6+/−) and hypothesized that the heterozygous deletion of Lrp6 would impair fracture healing. Mid-diaphyseal femur fractures were induced in Lrp6+/− mice and wild-type controls (Lrp6+/+). Fractures were analyzed using micro-computed tomography (μCT) scans, biomechanical testing, and histological analysis. Lrp6+/− mice had significantly decreased stiffness and strength at 28 days post fracture (PF) and significantly decreased BV/TV, total density, immature bone density, and mature area within the callus on day-14 and -21 PF; they had significantly increased empty callus area at days 14 and 21 PF. Our results demonstrate that the heterozygous deletion of Lrp6 impairs fracture healing, which suggests that Lrp6 has a role in fracture healing.
Inhibition of BET bromodomain-dependent XIAP and FLIP expression sensitizes KRAS-mutated NSCLC to pro-apoptotic agents
Authors: Klingbeil Olaf , Lesche Ralf , Gelato Kathy A , Haendler Bernard , Lejeune Pascale 
Published: September 2016

AbstractNon-small cell lung cancer (NSCLC) has the highest incidence of cancer-related death worldwide and a high medical need for more effective therapies. Small-molecule inhibitors of the bromodomain and extra terminal domain (BET) family such as JQ1, I-BET762 and OTX-015 are active in a wide range of different cancer types, including lung cancer. Although their activity on oncogene expression such as c-Myc has been addressed in many studies, the effects of BET inhibition on the apoptotic pathway remain largely unknown. Here we evaluated the activity of BET bromodomain inhibitors on cell cycle distribution and on components of the apoptosis response. Using a panel of 12 KRAS-mutated NSCLC models, we found that cell lines responsive to BET inhibitors underwent apoptosis and reduced their S-phase population, concomitant with downregulation of c-Myc expression. Conversely, ectopic c-Myc overexpression rescued the anti-proliferative effect of JQ1. In the H1373 xenograft model, treatment with JQ1 significantly reduced tumor growth and downregulated the expression of c-Myc. The effects of BET inhibition on the expression of 370 genes involved in apoptosis were compared in sensitive and resistant cells and we found the expression of the two key apoptosis regulators FLIP and XIAP to be highly BET dependent. Consistent with this, combination treatment of JQ1 with the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or the pro-apoptotic chemotherapeutic agent cisplatin enhanced induction of apoptosis in both BET inhibitor sensitive and resistant cells. Further we showed that combination of JQ1 with cisplatin led to significantly improved anti-tumor efficacy in A549 tumor-bearing mice. Altogether, these results show that the identification of BET-dependent genes provides guidance for the choice of drug combinations in cancer treatment. They also demonstrate that BET inhibition primes NSCLC cells for induction of apoptosis and that a combination with pro-apoptotic compounds represents a valuable strategy to overcome treatment resistance.
Metal-encapsulated organolead halide perovskite photocathode for solar-driven hydrogen evolution in water
Authors: Crespo-Quesada Micaela , Pazos-Outón Luis M. , Warnan Julien , Kuehnel Moritz F. , Friend Richard H. , Reisner Erwin 
Published: September 2016

AbstractLead-halide perovskites have triggered the latest breakthrough in photovoltaic technology. Despite the great promise shown by these materials, their instability towards water even in the presence of low amounts of moisture makes them, a priori, unsuitable for their direct use as light harvesters in aqueous solution for the production of hydrogen through water splitting. Here, we present a simple method that enables their use in photoelectrocatalytic hydrogen evolution while immersed in an aqueous solution. Field’s metal, a fusible InBiSn alloy, is used to efficiently protect the perovskite from water while simultaneously allowing the photogenerated electrons to reach a Pt hydrogen evolution catalyst. A record photocurrent density of −9.8 mA cm−2 at 0 V versus RHE with an onset potential as positive as 0.95±0.03 V versus RHE is obtained. The photoelectrodes show remarkable stability retaining more than 80% of their initial photocurrent for ∼1 h under continuous illumination.
Neutralizing blood-borne polyphosphate in vivo provides safe thromboprotection
Authors: Labberton Linda , Kenne Ellinor , Long Andy T. , Nickel Katrin F. , Di Gennaro Antonio , Rigg Rachel A. , Hernandez James S. , Butler Lynn , Maas Coen , Stavrou Evi X. , Renné Thomas 
Published: September 2016

AbstractPolyphosphate is an inorganic procoagulant polymer. Here we develop specific inhibitors of polyphosphate and show that this strategy confers thromboprotection in a factor XII-dependent manner. Recombinant Escherichia coli exopolyphosphatase (PPX) specifically degrades polyphosphate, while a PPX variant lacking domains 1 and 2 (PPX_Δ12) binds to the polymer without degrading it. Both PPX and PPX_Δ12 interfere with polyphosphate- but not tissue factor- or nucleic acid-driven thrombin formation. Targeting polyphosphate abolishes procoagulant platelet activity in a factor XII-dependent manner, reduces fibrin accumulation and impedes thrombus formation in blood under flow. PPX and PPX_Δ12 infusions in wild-type mice interfere with arterial thrombosis and protect animals from activated platelet-induced venous thromboembolism without increasing bleeding from injury sites. In contrast, targeting polyphosphate does not provide additional protection from thrombosis in factor XII-deficient animals. Our data provide a proof-of-concept approach for combating thrombotic diseases without increased bleeding risk, indicating that polyphosphate drives thrombosis via factor XII.
Observational learning computations in neurons of the human anterior cingulate cortex
Authors: Hill Michael R. , Boorman Erie D. , Fried Itzhak 
Published: September 2016

AbstractWhen learning from direct experience, neurons in the primate brain have been shown to encode a teaching signal used by algorithms in artificial intelligence: the reward prediction error (PE)—the difference between how rewarding an event is, and how rewarding it was expected to be. However, in humans and other species learning often takes place by observing other individuals. Here, we show that, when humans observe other players in a card game, neurons in their rostral anterior cingulate cortex (rACC) encode both the expected value of an observed choice, and the PE after the outcome was revealed. Notably, during the same task neurons recorded in the amygdala (AMY) and the rostromedial prefrontal cortex (rmPFC) do not exhibit this type of encoding. Our results suggest that humans learn by observing others, at least in part through the encoding of observational PEs in single neurons in the rACC.