bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of minimum transmit sum power and scheduling power gain for multi‐user MIMO‐OFDM networks with rate constraints
Authors: Gao Xiangyu , Zhu Yuesheng , Ping Li
Published: October 2014

Minimum transmit sum power (MTSP) is of high theoretical and practical value in multi‐user rate‐constrained systems; it is, however, quite difficult to be numerically characterized in complex channels for the prohibitively high computational power required. In this paper, we present a computationally efficient method to approximate the MTSP in multi‐user multiple‐input multiple‐output orthogonal frequency division multiplexing (MU‐MIMO‐OFDM) wireless networks. Specifically, we propose both lower and upper bounds of the MTSP, which are asymptotically accurate in the limit of large K, the number of users. Then, we develop two iterative water‐filling algorithms to numerically solve the proposed bounds. These algorithms are with low complexity, that is, linear in K, and therefore enable the analysis of MTSP in complex channels even if K is large. Numerical results demonstrate the effectiveness of the bounds in approximating the MTSP and the high computational efficiency of the proposed iterative water‐filling algorithms. With the proposed bounds, we further numerically study scheduling power gain (SPG), which is defined as MTSP reduction achieved by scheduling resources over multiple channel blocks in time domain. We simulate the SPG in different wireless environments defined in Third Generation Partnership Project spatial channel extended model and find insignificant SPG in some cases, indicating that the benefit from scheduling over multiple channel blocks is limited and simply allocating resources within the present channel is sufficient. Our analysis on the MTSP and SPG provides guidelines on the design of resource schedulers in MU‐MIMO‐OFDM networks. Copyright © 2014 John Wiley & Sons, Ltd.
Multiplierless filter‐bank based multicarrier system by using canonical signed digit representation
Authors: Aliasgari Mohammad , Marghi Yeganeh M. , Baharani Mohammadreza , Fakhraie Sied Mehdi
Published: October 2014

The filter‐bank based multicarrier (FBMC) system is a candidate for designing the physical layer of a cognitive radio because of its spectral efficiency and the spectral containment. The main drawback of such a system compared with orthogonal frequency division multiplexing systems is its high computation complexity, because each subcarrier is shaped by a non‐rectangular prototype filter. Although poly‐phase decomposition is suggested to decrease the sampling rate of filtering, the number of filtering operations (multiplications) is dramatically increased by the growing number of subcarriers and the amount of the desired spectral containment. Hence, hardware implementation of the FBMC system faces challenges such as high electrical power consumption and large silicon area occupation. In order to reduce computational complexity, a multiplierless filter design based on the canonical signed digit (CSD) representation is proposed. In this technique, at first, a prototype filter is designed. Then a pre‐optimization step is employed to adapt the prototype filter coefficients to system objectives and produce an enriched initial seed for genetic algorithm (GA) optimization. Finally, a customized GA is employed to jointly optimize and synthesize filter coefficients into the finite precision CSD representation so that the system objectives such as intersymbol‐interference, interchannel‐interference, and stop‐band attenuation remain unchanged against the full‐precision representation of coefficients. Copyright © 2014 John Wiley & Sons, Ltd.
Preparation, Structural, Thermogravimetric and Spectroscopic Study of Magnesium Potassium Arsenate Hexahydrate
Authors: Abdija Zuldjevat , Najdoski Metodija , Koleva Violeta , Runčevski Tomče , Dinnebier Robert E. , Šoptrajanov Bojan , Stefov Viktor
Published: October 2014

The crystal structure of magnesium potassium arsenate hexahydrate, MgKAsO4·6H2O, was refined from powder diffraction data. MgKAsO4·6H2O crystallizes in the orthorhombic space group Pmn21 with Z = 2, as the biomineral struvite. Complete dehydration of MgKAsO4·6H2O proceeds in a single step, with one endothermic peak at 87.9 °C (Tonset). The infrared and Raman spectra of protiated and deuterated polycrystalline samples were recorded at room temperature and at the boiling temperature of liquid nitrogen (LNT). The assignments of the observed bands are proposed and spectra‐structure correlations are made.
Crystal Structures of Homoleptic Propynyloargentates AI[Ag(C3H3)2] with AI = Ag, Li, Na Solved and Refined from X‐ray Powder Diffraction Data
Authors: Pak Leo , Zibrowius Bodo , Lumeij Marck‐Willem , Dronskowski Richard , Ruschewitz Uwe
Published: October 2014

The crystal structures of three isostructural homoleptic propynyloargentates, namely Ag[Ag(C3H3)2], Li[Ag(C3H3)2], and Na[Ag(C3H3)2] were solved and refined from laboratory X‐ray powder diffraction data (Iba2, Z = 4). Almost linear [H3C–C≡C···Ag···C≡C–CH3]– anions are found: The alkali metal cations or the second silver cation coordinate side‐on to the C≡C triple bond of the alkyne ligand (CN = 8) so that layer‐like structural fragments are formed, which are stacked in an AB fashion along [100]. These crystal structures are corroborated by IR and solid‐state NMR spectra. Powder SHG measurements confirm the acentric space group Iba2. On the other hand, these methods also supported a first structural model obtained earlier, in which very unusual bent [Ag(CCCH3)2]– units were found in a smaller unit cell (Amm2, Z = 2). Bond‐analytical COHP calculations clearly indicate that this structural motif cannot be stable. A close re‐inspection of the diffraction data, now also including high‐resolution synchrotron powder diffraction data (HASYLAB, beamline B2), reveal the existence of one weak additional reflection indicating a larger unit cell. Hence, this investigation clearly shows that under very specific circumstances – e.g. ligands with a weak scattering power compared to the central metal ion – wrong structural models can be obtained from X‐ray powder diffraction data, even when additional information from complementary spectroscopic methods is taken into account. Additional electronic‐structure calculations are therefore needed to elucidate the correct structural arrangement.
Resuscitative Thoracotomy in Penetrating Trauma
Authors: Fairfax Lindsay M. , Hsee Li , Civil Ian D.
Published: October 2014

The resuscitative thoracotomy (RT) is an important procedure in the management of penetrating trauma. As it is performed only in patients with peri‐arrest physiology or overt cardiac arrest, survival is low. Experience is also quite variable depending on volume of penetrating trauma in a particular region. Survival ranges from 0 % to as high as 89 % depending on patient selection, available resources, and location of RT (operating or emergency rooms). In this article, published guidelines are reviewed as well as outcomes. Technical considerations of RT and well as proper training, personnel, and location are also discussed.
Nonlinear Site Response Evaluation of Earthquakes: A Case Study from Sirdjan Balvavard Bridge, Kerman Province, Iran
Authors: SHAHRI ABBAS ABBASZADEH , ESFANDIYARI BIJAN , RAJABLOU ROSHANAK
Published: October 2014

The aim of this study is to illustrate the soil conditions encountered at the proposed bridge sites to analyze and evaluate the test conducted, submit recommendations regarding foundation design. At first by field investigation, the required data was collected and after primary processing the acceptable data was selected. For nonlinear analysis of elastic and rigid half space bed rock, standard hyperbolic model was selected and performed, and the results were compared. The study clearly showed that the effect of bed rock on soil behavior during earthquake is one of the main factors controlling prediction of ground response. A critical aspect of this work was to develop and use a computer code “Abbas Converter” developed by the authors that has several advantages, such as quick installation, acting as a connecter function between the used softwares which can generate the input data corresponding to a defined format and finally, the results of this computer code can be easily exported to the other softwares used in this study. Moreover this code can make it easy to solve the problems encountered.
Assessment of Hydrogeochemical Processes in a Coastal Region: Application of Multivariate Statistical Model
Authors: Rao N. Subba , Vidyasagar G. , Rao P. Surya , Bhanumurthy P.
Published: October 2014

Hydrogeochemical studies have been carried out in a coastal region, using multivariate statistical model, for better understanding the controlling processes that influence the aquifer chemistry. Two principal components (PC1 and PC2) are extracted from the data set of chemical variables (pH, TDS, Ca2+, Mg2+, Na+, K+, HCO3−, Cl−, SO42−, NO3− and F−), which account for 79% of the total variation in the quality of groundwater. The PC1 (salinity controlled process) includes the concentrations of TDS, Mg2+, Na+, K+, Cl−, SO42− and NO3−, while the PC2 (alkalinity controlled process) comprises the concentrations of pH, HCO3− and F−. The spatial distribution of PC scores identifies the locations of high salinity and alkalinity processes. The first process corresponds to the influences of geogenic, anthropogenic and marine sources, and the second one to the influence of water-soil-rock interaction. Thus, the present study shows the usefulness of multivariate statistical model as an effective means of interpretation of spatial controlling processes of groundwater chemistry.
Prácticas de evaluación financiera de inversiones en Colombia
Authors: Vecino Carlos Enrique , Rojas Silvia Carolina , Munoz Yaromir
Published: October 2014

El objetivo de este estudio es identificar los criterios y prácticas para la evaluación de inversiones en empresas que operan en Colombia. La metodología empleada fue una encuesta a 300 empresas, a partir de lo cual se realiza un análisis estadístico descriptivo que destaca como criterios predominantes el valor presente neto, la tasa interna de retorno y la relación beneficio/costo; adicionalmente se llevó a cabo un análisis inferencial del efecto de diversas características de las empresas estudiadas sobre una variable denominada «Índice de buen uso» en los criterios predominantes. Este análisis permite concluir que el tamaño de empresa y el nivel de estudios de los directivos constituyen 2 factores relevantes para una organización en el momento de elegir el criterio y las prácticas para evaluar sus proyectos de inversión.
El clima organizacional y su relación con la calidad de los servicios públicos de salud: diseño de un modelo teórico
Authors: Bernal González Idolina , Pedraza Melo Norma Angélica , Sánchez Limón Mónica Lorena
Published: October 2014

Mediante la exploración de 83 investigaciones teóricas y empíricas publicadas en países de Latinoamérica durante el siglo xxi, este trabajo pretende 2 objetivos principales. Primero, examinar la multidimensionalidad y las características fundamentales de las variables de clima organizacional y calidad de los servicios públicos de salud; segundo, diseñar un modelo teórico sobre la relación que existe entre estas 2 variables. El estudio se efectuó mediante la estrategia de investigación documental, método de análisis que comprende la revisión de literatura, detección, consulta, extracción/recopilación e integración de datos. Del análisis realizado se infiere teóricamente que existe una relación entre el clima organizacional y la calidad de los servicios públicos de salud; sin embargo, se recomienda realizar estudios empíricos que refuercen la perspectiva teórica analizada.
Oncogenic signaling in amphiregulin and EGFR‐expressing PTEN‐null human breast cancer
Authors: Kappler Christiana S. , Guest Stephen T. , Irish Jonathan C. , Garrett-Mayer Elizabeth , Kratche Zachary , Wilson Robert C. , Ethier Stephen P.
Published: October 2014

A subset of triple negative breast cancer (TNBC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) and loss of PTEN, and patients with these determinants have a poor prognosis. We used cell line models of EGFR‐positive/PTEN null TNBC to elucidate the signaling networks that drive the malignant features of these cells and cause resistance to EGFR inhibitors. In these cells, amphiregulin (AREG)‐mediated activation of EGFR results in up‐regulation of fibronectin (FN1), which is known to be a mediator of invasive capacity via interaction with integrin β1. EGFR activity in this PTEN null background also results in Wnt/beta‐catenin signaling and activation of NF‐κB. In addition, AKT is constitutively phosphorylated in these cells and is resistant to gefitinib. Expression profiling demonstrated that AREG‐activated EGFR regulates gene expression differently than EGF‐activated EGFR, and functional analysis via genome‐scale shRNA screening identified a set of genes, including PLK1 and BIRC5, that are essential for survival of SUM‐149 cells, but are uncoupled from EGFR signaling. Thus, our results demonstrate that in cells with constitutive EGFR activation and PTEN loss, critical survival genes are uncoupled from regulation by EGFR, which likely mediates resistance to EGFR inhibitors.
Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon
Authors: Gilmour Daniel M. , Butler Virginia L. , O'Connor Jim E. , Davis Edward Byrd , Culleton Brendan J. , Kennett Douglas J. , Hodgins Gregory
Published: October 2014

Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and paleoenvironmental conditions. Using subfossil material from the northern valley, we use AMS radiocarbon dating, stable isotope (δ13C and δ15N) analyses, and taxonomic dietary specialization and habitat preferences to reconstruct environments and to develop a local chronology of events that we then compare with continental and regional archaeological and paleoenvironmental data. Analysis of twelve bone specimens demonstrates the presence of bison, mammoth, horse, sloth, and mastodon from ~ 15,000–13,000 cal yr BP. The latest ages coincide with changing regional climate corresponding to the onset of the Younger Dryas. It is suggested that cooling conditions led to increased forest cover, and along with river aggradation, reduced the area of preferred habitat for the larger bodied herbivores, which contributed to the demise of local megafauna. Archaeological evidence for megafauna–human interactions in the Pacific Northwest is scarce, limiting our ability to address the human role in causing extinction.
On a random time series analysis valid for arbitrary spectral shape
Authors: Janssen Peter A. E. M.
Published: October 2014

While studying the problem of predicting freak waves it was realized that it would be advantageous to introduce a simple measure for such extreme events. Although it is customary to characterize extremes in terms of wave height or its maximum it is argued in this paper that wave height is an ill-defined quantity in contrast to, for example, the envelope of a wave train. Also, the last measure has physical relevance, because the square of the envelope is the potential energy of the wave train. The well-known representation of a narrow-band wave train is given in terms of a slowly varying envelope function ${\it\rho}$ and a slowly varying frequency ${\it\omega}=-\partial {\it\phi}/\partial t$ where ${\it\phi}$ is the phase of the wave train. The key point is now that the notion of a local frequency and envelope is generalized by also applying the same definitions for a wave train with a broad-banded spectrum. It turns out that this reduction of a complicated signal to only two parameters, namely envelope and frequency, still provides useful information on how to characterize extreme events in a time series. As an example, for a linear wave train the joint probability distribution of envelope height and period is obtained and is validated against results from a Monte Carlo simulation. The extension to the nonlinear regime is, as will be seen, fairly straightforward.
Analytic Approximate Solutions and Numerical Results for Stagnation Point Flow of Jeffrey Fluid Towards an Off-Centered Rotating Disk
Authors: Khan N. A. , Khan S. , Riaz F.
Published: October 2014

The present paper studies the three-dimensional, off centered stagnation flow of a Jeffrey fluid over a rotating disk. The governing non-linear equations and their associated boundary conditions are transformed into coupled ordinary differential equations by utilizing an appropriate similarity transformation. Homotopy analysis method is utilized to evaluate the analytical solution in the form of infinite series. Also, the convergence region of the obtained solution is determined and plotted. The effects of pertaining parameters on radial, azimuthal and induced velocities of the fluid flow are presented graphically and discussed. Moreover comparisons have also been made with the previous results as a special case.
To Link or Not to Link? Agenda Change in International Bargaining
Authors: Mckibben Heather Elko
Published: October 2014

Agendas shape the strategies states adopt in international bargaining and, therefore, the substantive nature of the resulting outcomes. They are also a dynamic feature of the process, as states add and subtract issues in order to shift the bargaining outcome in their favor. This article analyzes when and why states will use these different ‘issue-linkage’ strategies. Focusing on the effects of a successful agreement and the costs of failure, it highlights conditions under which states are likely to add or subtract issues from the bargaining agenda. It tests these arguments using an original dataset of the bargaining strategies states have adopted in climate-change negotiations. It concludes by highlighting the implications the argument has for understanding the outcomes of international negotiations.
Taxonomic delimitation of the genera Bryoria and Sulcaria, with a new combination Sulcaria spiralifera introduced
Authors: MYLLYS Leena , VELMALA Saara , LINDGREN Hanna , GLAVICH Doug , CARLBERG Tom , WANG Li-Song , GOWARD Trevor
Published: October 2014

Bryoria pseudocapillaris and B. spiralifera are currently treated as members of Bryoria section Implexae although conspicuous, long and depressed pseudocyphellae characterizing both species resemble those found in the genus Sulcaria. Both genera belong in Parmeliaceae and form an alectorioid group together with Alectoria, Gowardia and Pseudephebe. Parsimony and Bayesian analyses of ITS, partial GAPDH and partial Mcm7 sequence data were used to examine the phylogenetic position of B. pseudocapillaris and B. spiralifera, and in light of these results evaluate the generic delimitation of Bryoria and Sulcaria. A total of 110 specimens of 53 species containing representatives from alectorioid and closely related genera were included in the analyses. The results clearly show first, that both B. pseudocapillaris and B. spiralifera belong in Sulcaria rather than in Bryoria, and second, that they should be considered conspecific. Bryoria pseudocapillaris is proposed as a synonym under B. spiralifera and the name Sulcaria spiralifera comb. nov. is introduced.
Three new Diorygma (Graphidaceae) species from Brazil, with a revised world key
Authors: FEUERSTEIN Shirley Cunha , CUNHA-DIAS Iane Paula Rego , APTROOT André , ELIASARO Sionara , CÁCERES Marcela Eugenia da Silva
Published: October 2014

Three new corticolous Diorygma species are described from Brazil. Diorygma incantatum has transversely 29–31-septate, filiform ascospores 105–108×6 µm, and produces an unidentified substance with Rf 44 in solvent C. Diorygma pauciseptatum produces norstictic and connorstictic acids and has transversely 7–9-septate, I+ blue-violet, large ascospores 28–32×7 µm, surrounded by a gelatinous sheath c. 2 µm wide that is often somewhat expanded at one end. Diorygma tocantinense contains protocetraric acid and has muriform, broadly fusiform ascospores with rounded ends, 24–40×10–15 µm, surrounded by an gelatinous sheath up to c. 5 µm wide that is somewhat expanded at central parts of the ascospore. A revised world key is given to all currently known species of Diorygma.
Spatio-temporal modelling of disease incidence with missing covariate values
Authors: HOLLAND R. C. , JONES G. , BENSCHOP J.
Published: October 2014

The search for an association between disease incidence and possible risk factors using surveillance data needs to account for possible spatial and temporal correlations in underlying risk. This can be especially difficult if there are missing values for some important covariates. We present a case study to show how this problem can be overcome in a Bayesian analysis framework by adding to the usual spatio-temporal model a component for modelling the missing data.
Assessment of inter-atrial, inter-ventricular, and atrio-ventricular interactions in tetralogy of Fallot patients after surgical correction. Insights from two-dimensional speckle tracking and three-dimensional echocardiography
Authors: Abd El Rahman Mohamed , Raedle-Hurst Tanja , Rentzsch Axel , Schäfers Hans-Joachim , Abdul-Khaliq Hashim
Published: October 2014

Background: We aimed to assess biatrial size and function, interactions on atrial and ventricular levels, and atrio-ventricular coupling in patients after tetralogy of Fallot repair. Methods: A total of 34 patients with a mean age of 20.9±9 years, and 35 healthy controls, underwent two-dimensional speckle tracking echocardiography for ventricular and atrial strain measurements and real-time three-dimensional echocardiography to assess ventricular and atrial volumes. Results: When compared with controls, tetralogy of Fallot patients had significantly reduced right atrial peak atrial longitudinal strain (p<0.01), right atrial peak atrial contraction strain (p<0.01), right atrial ejection fraction (p<0.01), left atrial peak atrial longitudinal strain (p<0.01), left atrial peak atrial contraction strain (p<0.05), and left atrial ejection fraction (p<0.01). In the tetralogy of Fallot group, left ventricular ejection fraction was negatively related to the right ventricular end-systolic volume normalised to body surface area (r=−0.62, p<0.01). An association was found in patients between the right atrial peak longitudinal strain and mean right ventricular strain (r=0.64, p<0.01). In patients, the left atrial peak longitudinal strain correlated negatively with right atrial end-diastolic volume normalised to body surface area (r=−0.67, p<0.01), whereas the left atrial ejection fraction correlated weakly with left ventricular ejection fraction (r=0.41, p<0.05). Conclusions: In asymptomatic tetralogy of Fallot patients, biatrial dysfunction exists and can be quantified via two-dimensional speckle tracking echocardiography as well as real-time three-dimensional echocardiography. Different forms of interactions on atrial and ventricular levels are evident among such cohorts.
Differential and selective morpho-syntactic impairment in Spanish-Basque bilingual aphasia
Authors: MUNARRIZ AMAIA , EZEIZABARRENA MARIA-JOSÉ , GUTIERREZ-MANGADO M. JUNCAL
Published: October 2014

This paper reports on the comprehension of movement-derived structures by a Spanish-Basque bilingual with chronic Broca's aphasia. The study reveals adifferential impairmentwhich affects mostly Basque and aselective impairmentin this language that affects only object questions and subject relatives. The impairment pattern observed is discussed in light of the predictions made by different representational and processing accounts for (monolingual as well as bilingual) Spanish and Basque agrammatism.

The asymmetry observed between the two languages suggests that the patient resorts to language-specific morpho-syntactic cues, which cannot be transferred from one language to the other because of the typological distance between Spanish and Basque. The data confirm results from previous studies showing that (major) typological distance hinders cross-language effects from arising in bilingual aphasia.
Counter-regulatory effects played by the ACE – Ang II – AT1 and ACE2 – Ang-(1–7) – Mas axes on the reactive oxygen species-mediated control of vascular function: perspectives to pharmacological approaches in controlling vascular complications
Authors: Pernomian Laena , Pernomian Larissa , Baraldi Araújo Restini Carolina
Published: October 2014

The Renin-Angiotensin system plays an important role in the regulation of systemic blood pressure as well as in fluid and electrolyte balance. It is divided into two described axes, the ACE – Ang II – AT1 receptor, with Ang II as the main mediator, and the ACE2 – Ang-(1–7) – Mas receptor, with Ang-(1–7) responsible for the main effects. The main vascular effect induced by Ang II is contraction, while Ang-(1–7) includes relaxation in several vascular beds. Ang II also activates several cytokines that are important in the genesis of vascular inflammation and hypertrophy. In this context, Ang-(1–7) seems to have a protective role. Both AT1 and Mas receptors modulate, in different ways, the generation of, which are involved in the control of vascular tone and the genesis of vascular dysfunction triggered by several diseases, including diabetes mellitus, arterial hypertension and atherosclerosis. Thereby, this review presents an overview of the modulation played by the whole Renin-Angiotensin system on the reactive oxygen species-mediated control of vascular tone and the oxidative stress-elicited vascular dysfunction.
Clinical, electrocardiographic and echocardiographic features in patients with major arterial vascular disease assigned to surgical revascularization
Authors: Tsialtas Dimitri , Bolognesi Maria G. , Tecchio Tiziano , Azzarone Matteo , Quaini Federico , Bolognesi Roberto
Published: October 2014

Background: Preoperative cardiac assessment may essentially contribute to estimate the operative risk in vascular surgery.This study was undertaken to depict the clinical conditions and cardiac status in patients before elective major vascular surgery. Patients and methods: 143 patients with asymptomatic critical aortic abdominal aneurysm, 119 with high-grade carotid stenosis, and 138 with advanced symptomatic ischemia due to peripheral artery disease were assigned to surgical revascularization. Preoperatively, all subjects completed detailed medical history, physical and laboratory examinations, electrocardiogram, and transthoracic echocardiography. Results: In patients with peripheral artery disease we identified more smokers (p < 0.05), diabetes (p < 0.01), hypertriglyceridemia (p < 0.05), previous myocardial infarction (p < 0.01); the asymptomatic aortic abdominal aneurysm group had a higher body mass index (p < 0.05), diastolic hypertension (p < 0.05), and most had left ventricular anterior hemiblocks (p < 0.001). Patients with critical carotid stenosis were older (p < 0.01), with greater systolic hypertension (p < 0.01), and with a less compromised left ventricular systolic function. Conclusions: Patients with peripheral artery disease were mostly affected by severe metabolic diseases and by worst cardiac conditions; patients with asymptomatic abdominal aortic aneurysms were of robust physique, and often had left ventricular anterior hemiblocks. Patients with critical carotid stenosis were older and had less cardiomyopathies.
Endovascular management of vascular complications after percutaneous nephrolithotomy
Authors: Kervancioglu Selim , Gelebek Yilmaz Feyza , Erturhan Sakip
Published: October 2014

Background: Bleeding is one of the most common and most important complications of percutaneous nephrolithotomy (PCNL), which is mainly controlled with conservative treatment options. Transcatheter arterial embolization is required in less than 1 % of the patients undergoing PCNL. There are only a few studies about endovascular treatment of vascular complications of PCNL. The purpose of this study was to evaluate renal arterial complications of PCNL and treatment outcomes with endovascular coil embolization. Patients and methods: This retrospective study evaluated 16 patients who underwent endovascular management for complications after PCNL, including diagnostic angiography. We analyzed the angiographic appearances of the vascular lesions that caused hemorrhages, treatment outcomes for endovascular coil embolization, and renal parenchymal loss rate following this treatment. Results: Seven patients had a pseudoaneurysm, two patients had an arteriocaliceal fistula (ACF), five patients had a pseudoaneurysm and an arteriovenous fistula (AVF), and two patients had a pseudoaneurysm and an ACF. Of the 14 patients with pseudoaneurysms, five had more than one pseudoaneurysm. Endovascular coil embolization was successful in all patients, and it was able to stop the bleeding. After embolization, 12 patients had less than 10 % parenchymal loss, and 4 patients had 10–20 % parenchymal loss. Mean hospital stay after embolization was 2.3 ± 0.7 days (range, 1 to 3 days). Conclusions: The injuries seen in the intrarenal arterial system during the PCNL procedure can result in pseudoaneurysms and/or AVFs and/or ACFs, and more than one artery can be harmed. Arterial complications of PCNL can be treated with endovascular coil embolization while preserving renal function at a maximum level.
CXCR7 stimulates MAPK signaling to regulate hepatocellular carcinoma progression
Authors: Lin L , Han M-M , Wang F , Xu L-L , Yu H-X , Yang P-Y
Published: October 2014

The CXCL12/CXCR4 axis has been posited widely to have significant roles in many primary tumors and metastases. It is known that CXCR7 can also be engaged by CXCL12, but the exact function of CXCR7 is controversial. This prompted us to investigate the expression, specific function and signal transduction of CXCR7 in hepatocellular carcinoma (HCC). In this study, CXCR7 and CXCR4 were differentially expressed in nine cell lines of HCC, and that elevated expression of both CXCR7 and CXCL4 were correlated with highly metastatic ability of HCC cells. Moreover, CXCR7 expression was significantly upregulated in metastatic HCC samples compared with the non-metastatic ones by staining of high-density tissue microarrays constructed from a cohort of 48 human HCC specimens. CXCR7 overexpression enhanced cell growth and invasiveness in vitro, and tumorigenicity and lung metastasis in vivo. By contrast, CXCR7 stable knockdown markedly reduced these malignant behaviors. In addition, it was observed that alterations in CXCR7 expression were positively correlated with the phosphorylation levels of mitogen-activated protein kinase (MAPK) pathway proteins. Targeting extracellular regulated kinase pathway by using U0126 inhibitor or using CCX771, a selective CXCR7 antagonist, drastically reduced CXCR7-mediated cell proliferation. Importantly, by using human biotin-based antibody arrays, several differentially expressed proteins were identified in CXCR7-overexpression and depletion groups. Comparative analysis indicated that upstream regulators including TP53 and IL-6 were involved in CXCR7 signal transduction. CXCR7 expression was further proved to regulate expression of vascular endothelial growth factor A and galectin-3, which may contribute to tumor angiogenesis and invasiveness. Consequently, elevated expression of CXCR7 contributes to HCC growth and invasiveness via activation of MAPK and angiogenesis signaling pathways. Targeting CXCR7 may prevent metastasis and provide a potential therapeutic strategy for HCC.
Mcl-1 promotes lung cancer cell migration by directly interacting with VDAC to increase mitochondrial Ca2+ uptake and reactive oxygen species generation
Authors: Huang H , Shah K , Bradbury N A , Li C , White C
Published: October 2014

Mcl-1 is an antiapoptotic member of the Bcl-2 family frequently upregulated in non-small cell lung carcinoma (NSCLC). We now report the physiological significance of an interaction between Mcl-1 and the mitochondrial outer membrane-localized voltage-dependent anion channel (VDAC) in NSCLC cell lines. Mcl-1 bound with high affinity to VDAC1 and 3 isoforms but only very weakly to VDAC2 and binding was disrupted by peptides based on the VDAC1 sequence. In A549 cells, reducing Mcl-1 expression levels or application of VDAC-based peptides limited Ca2+ uptake into the mitochondrial matrix, the consequence of which was to inhibit reactive oxygen species (ROS) generation. In A549, H1299 and H460 cells, both Mcl-1 knockdown and VDAC-based peptides attenuated cell migration without affecting cell proliferation. Migration was rescued in Mcl-1 knockdown cells by experimentally restoring ROS levels, consistent with a model in which ROS production drives increased migration. These data suggest that an interaction between Mcl-1 and VDAC promotes lung cancer cell migration by a mechanism that involves Ca2+-dependent ROS production.
Dynamic involvement of ATG5 in cellular stress responses
Authors: Lin H H , Lin S-M , Chung Y , Vonderfecht S , Camden J M , Flodby P , Borok Z , Limesand K H , Mizushima N , Ann D K
Published: October 2014

Autophagy maintains cell and tissue homeostasis through catabolic degradation. To better delineate the in vivo function for autophagy in adaptive responses to tissue injury, we examined the impact of compromised autophagy in mouse submandibular glands (SMGs) subjected to main excretory duct ligation. Blocking outflow from exocrine glands causes glandular atrophy by increased ductal pressure. Atg5f/−;Aqp5-Cre mice with salivary acinar-specific knockout (KO) of autophagy essential gene Atg5 were generated. While duct ligation induced autophagy and the expression of inflammatory mediators, SMGs in Atg5f/−;Aqp5-Cre mice, before ligation, already expressed higher levels of proinflammatory cytokine and Cdkn1a/p21 messages. Extended ligation period resulted in the caspase-3 activation and acinar cell death, which was delayed by Atg5 knockout. Moreover, expression of a set of senescence-associated secretory phenotype (SASP) factors was elevated in the post-ligated glands. Dysregulation of cell-cycle inhibitor CDKN1A/p21 and activation of senescence-associated β-galactosidase were detected in the stressed SMG duct cells. These senescence markers peaked at day 3 after ligation and partially resolved by day 7 in post-ligated SMGs of wild-type (WT) mice, but not in KO mice. The role of autophagy-related 5 (ATG5)-dependent autophagy in regulating the tempo, duration and magnitude of cellular stress responses in vivo was corroborated by in vitro studies using MEFs lacking ATG5 or autophagy-related 7 (ATG7) and autophagy inhibitors. Collectively, our results highlight the role of ATG5 in the dynamic regulation of ligation-induced cellular senescence and apoptosis, and suggest the involvement of autophagy resolution in salivary repair.
MicroRNA-30d regulates cardiomyocyte pyroptosis by directly targeting foxo3a in diabetic cardiomyopathy
Authors: Li X , Du N , Zhang Q , Li J , Chen X , Liu X , Hu Y , Qin W , Shen N , Xu C , Fang Z , Wei Y , Wang R , Du Z , Zhang Y , Lu Y
Published: October 2014

Diabetic cardiomyopathy is a common cardiac condition in patients with diabetes mellitus, which can result in cardiac hypertrophy and subsequent heart failure, associated with pyroptosis, the pro-inflammatory programmed cell death. MicroRNAs (miRNAs), small endogenous non-coding RNAs, have been shown to be involved in diabetic cardiomyopathy. However, whether miRNAs regulate pyroptosis in diabetic cardiomyopathy remains unknown. Our study revealed that mir-30d expression was substantially increased in streptozotocin (STZ)-induced diabetic rats and in high-glucose-treated cardiomyocytes as well. Upregulation of mir-30d promoted cardiomyocyte pyroptosis in diabetic cardiomyopathy; conversely, knockdown of mir-30d attenuated it. In an effort to understand the signaling mechanisms underlying the pro-pyroptotic property of mir-30d, we found that forced expression of mir-30d upregulated caspase-1 and pro-inflammatory cytokines IL-1β and IL-18. Moreover, mir-30d directly repressed foxo3a expression and its downstream protein, apoptosis repressor with caspase recruitment domain (ARC). Furthermore, silencing ARC by siRNA mimicked the action of mir-30d: upregulating caspase-1 and inducing pyroptosis. These findings promoted us to propose a new signaling pathway leading to cardiomyocyte pyroptosis under hyperglycemic conditions: mir-30d↑→foxo3a↓→ ARC↓→caspase-1↑→IL-1β, IL-18↑→pyroptosis↑. Therefore, mir-30d may be a promising therapeutic target for the management of diabetic cardiomyopathy.
HDAC1 and Klf4 interplay critically regulates human myeloid leukemia cell proliferation
Authors: Huang Y , Chen J , Lu C , Han J , Wang G , Song C , Zhu S , Wang C , Li G , Kang J , Wang J
Published: October 2014

Acute myeloid leukemia (AML) is recognized as a complex disease of hematopoietic stem cell disorders, but its pathogenesis mechanisms, diagnosis, and treatment remain unclear. General histone deacetylase (HDAC) inhibitors have been used in blood cancers including AML, but the lack of gene specificity greatly limits their anti-cancer effects and clinical applications. Here, we found that HDAC1 expression was negatively correlated with that of Krüppel-like factor 4 (Klf4) and that AML patients with lower HDAC1 level had better prognosis. Further, knockdown of HDAC1 in leukemia cells K562, HL-60, and U937 significantly increased Klf4 expression and inhibited cell cycle progression and cell proliferation, similar results were found for HDAC inhibitors (VPA and mocetinostat). Moreover, overexpression or knockdown of Klf4 could markedly block the effects of HDAC1 overexpression or knockdown on leukemia cells in vitro and in vivo, respectively. Mechanistic analyses demonstrated that HDAC1 and Klf4 competitively bound to the promoter region of Klf4 and oppositely regulated Klf4 expression in myeloid leukemia. We identified HDAC1 as a potential specific target for repressing cell proliferation and inducing cell cycle arrest through interplay and modulation of Klf4 expression, suggests that HDAC1 and Klf4 are potential new molecular markers and targets for clinical diagnosis, prognosis, and treatment of myeloid leukemia.
Pro-oxidant/antioxidant balance controls pancreatic β-cell differentiation through the ERK1/2 pathway
Authors: Hoarau E , Chandra V , Rustin P , Scharfmann R , Duvillie B
Published: October 2014

During embryogenesis, the intrauterine milieu affects cell proliferation, differentiation, and function by modifying gene expression in susceptible cells, such as the pancreatic β-cells. In this limited energy environment, mitochondrial dysfunction can lead to overproduction of reactive oxygen species (ROS) and to a decline in β-cell function. In opposition to this toxicity, ROS are also required for insulin secretion. Here we investigated the role of ROS in β-cell development. Surprisingly, decreasing ROS production in vivo reduced β-cell differentiation. Moreover, in cultures of pancreatic explants, progenitors were highly sensitive to ROS stimulation and responded by generating β-cells. ROS enhanced β-cell differentiation through modulation of ERK1/2 signaling. Gene transfer and pharmacological manipulations, which diminish cellular ROS levels, also interfered with normal β-cell differentiation. This study highlights the role of the redox balance on β-cell development and provides information that will be useful for improving β-cell production from embryonic stem cells, a step in cell therapy for diabetes.
Polycomb protein EZH2 suppresses apoptosis by silencing the proapoptotic miR-31
Authors: Zhang Q , Padi S K R , Tindall D J , Guo B
Published: October 2014

Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 and suppresses gene expression by catalyzing histone H3 methylation on lysine 27. EZH2 is overexpressed in metastatic prostate cancer and has been shown to promote cell proliferation and metastasis. Here we show that EZH2 also suppresses prostate cancer apoptosis by coordinating the epigenetic silencing of two proapoptotic microRNAs (miRNA), miR-205 and miR-31. We previously reported that miR-205 promotes apoptosis by targeting antiapoptotic protein Bcl-w and miR-205 is silenced in prostate cancer through promoter methylation. In this study, we found that EZH2 suppresses miR-31 expression by trimethylation of lysine 27 on histone 3 on the miR-31 promoter. SiRNA knockdown of EZH2 increased miR-31 expression and decreased the antiapoptotic protein E2F6 (E2F transcription factor 6) (a target of miR-31), resulting in the sensitization of prostate cancer cells to docetaxel-induced apoptosis. Conversely, overexpression of EZH2 blocked docetaxel-induced apoptosis. We further demonstrated that miR-205 silencing is linked to miR-31 silencing through EZH2. Suppression of miR-205 with an miRNA inhibitor caused an increase of EZH2 protein, which in turn inhibited miR-31 expression. Conversely, overexpression of miR-205 decreased EZH2 protein and increased miR-31 expression. In paired human prostate cancer specimens and adjacent normal tissues, we observed that the decrease of miR-205 expression correlated with EZH2 overexpression and miR-31 silencing. Thus, EZH2 integrates the epigenetic silencing of miR-205 and miR-31 to confer resistance to chemotherapy-induced apoptosis.
Arrest defective 1 regulates the oxidative stress response in human cells and mice by acetylating methionine sulfoxide reductase A
Authors: Shin S-H , Yoon H , Chun Y-S , Shin H-W , Lee M-N , Oh G T , Park J-W
Published: October 2014

Methionine sulfoxide reductase A (MSRA) protects proteins from oxidation, and also helps remove reactive oxygen species (ROS) by recovering antioxidant enzymes inactivated by oxidation. Although its functions have been investigated extensively, little is known about the mechanism by which MSRA is regulated. Arrest defective 1 (ARD1) is an enzyme that catalyzes not only N-terminal acetylation as a cotranslational modification but also lysine acetylation as a posttranslational modification. ARD1, which is expressed in most cell types, is believed to participate in diverse biological processes, but its roles are poorly understood. Given that MSRA was hunted in a yeast two-hybrid screen with ARD1 as the bait, we here investigated whether ARD1 is a novel regulator of MSRA. ARD1 was shown to interact with and acetylate MSRA in both cells and test tubes. It specifically acetylated the K49 residue of MSRA, and by doing so repressed the enzymatic function of MSRA. ARD1 increased cellular levels of ROS, carbonylated proteins and DNA breaks under oxidative stress. Moreover, it promoted cell death induced by pro-oxidants, which was attenuated in MSRA-deficient cells. When mice were exposed to hyperoxic conditions for 2 days, their livers and kidneys were injured and protein carbonylation was increased. The oxidative tissue injury was more severe in ARD1 transgenic mice than in their wild-type littermates. In conclusion, ARD1 has a crucial role in the cellular response to oxidative stress as a bona fide regulator of MSRA. ARD1 is a potential target for ameliorating oxidative injury or for potentiating ROS-producing anticancer agents.
Enzyme-responsive polymer assemblies constructed through covalent synthesis and supramolecular strategy
Authors: Ding Yan , Kang Yuetong , Zhang Xi
Published: October 2014

Enzyme-responsive polymer assemblies have continually gained progress through the introduction of new enzymes and the development of new strategies for their preparation. In addition, kinetic studies will pave the way for tuning the response rate in a controlled manner.
The room temperature electrochemical synthesis of N-doped graphene and its electrocatalytic activity for oxygen reduction
Authors: Ma Feng-Xiang , Wang Jiong , Wang Feng-Bin , Xia Xing-Hua
Published: October 2014

N doping in graphene can be achieved using a facile and mild approach using electrochemical energy at room temperature with ammonia as the N source, which occurs at the carbon active sites generatedin situduring the removal of oxygen containing species at cathodic potentials.
Synthesis, mechanism of formation, and catalytic activity of Xantphos nickel π-complexes
Authors: Staudaher Nicholas D. , Stolley Ryan M. , Louie Janis
Published: October 2014

A general synthetic route to the first Xantphos nickel alkyne and alkene complexes has been discovered.
Transition metal catalysis in confined spaces
Authors: Leenders Stefan H. A. M. , Gramage-Doria Rafael , de Bruin Bas , Reek Joost N. H.
Published: October 2014

This review discusses different strategies to provide transition metal catalysts with a second coordination sphere and the effect this has in catalysis.
Molybdenum blue nano-rings: an effective catalyst for the partial oxidation of cyclohexane
Authors: Liu Xi , Conte Marco , Weng Weihao , He Qian , Jenkins Robert L. , Watanabe Masashi , Morgan David J. , Knight David W. , Murphy Damien M. , Whiston Keith , Kiely Christopher J. , Hutchings Graham J.
Published: October 2014

Molybdenum blue (MB), a multivalent molybdenum oxide with a nano-ring morphology is well-known in analytical chemistry but, to date it has been largely ignored in other applications.
Two-dimensional sum-frequency generation (2D SFG) spectroscopy: summary of principles and its application to amyloid fiber monolayers
Authors: Ghosh Ayanjeet , Ho Jia-Jung , Serrano Arnaldo L. , Skoff David R. , Zhang Tianqi , Zanni Martin T.
Published: October 2014

By adding a mid-infrared pulse shaper to a sum-frequency generation (SFG) spectrometer, we have built a 2D SFG spectrometer capable of measuring spectra analogous to 2D IR spectra but with monolayer sensitivity and SFG selection rules. In this paper, we describe the experimental apparatus and provide an introduction to 2D SFG spectroscopy to help the reader interpret 2D SFG spectra. The main aim of this manuscript is to report 2D SFG spectra of the amyloid forming peptide FGAIL. FGAIL is a critical segment of the human islet amyloid polypeptide (hIAPP or amylin) that aggregates in people with type 2 diabetes. FGAIL is catalyzed into amyloid fibers by many types of surfaces. Here, we study the structure of FGAIL upon deposition onto a gold surface covered with a self-assembled monolayer of methyl-4-mercaptobenzoate (MMB) that produces an ester coating. FGAIL deposited on bare gold does not form ordered layers. The measured 2D SFG spectrum is consistent with amyloid fiber formation, exhibiting both the parallel (a+) and perpendicular (a−) symmetry modes associated with amyloid β-sheets. Cross peaks are observed between the ester stretches of the coating and the FGAIL peptides. Simulations are presented for two possible structures of FGAIL amyloid β-sheets that illustrate the sensitivity of the 2D SFG spectra to structure and orientation. These results provide some of the first molecular insights into surface catalyzed amyloid fiber structure.
UHPLC-LTQ-Orbitrap MS combined with spike-in method for plasma metabonomics analysis of acute myocardial ischemia rats and pretreatment effect of Danqi Tongmai tablet
Authors: Yan Bingpeng , Deng Yanping , Hou Jinjun , Bi Qirui , Yang Min , Jiang Baohong , Liu Xuan , Wu Wanying , Guo Dean
Published: October 2014

Metabonomics analysis revealed the presumable pathological processes in the early stages of AMI and provided useful information on the pretreatment efficacy of DQTM.
Controlling the spatial arrangement of organic magnetic anions adsorbed on epitaxial graphene on Ru(0001)
Authors: Stradi Daniele , Garnica Manuela , Díaz Cristina , Calleja Fabián , Barja Sara , Martín Nazario , Alcamí Manuel , Vazquez de Parga Amadeo L. , Miranda Rodolfo , Martín Fernando
Published: October 2014

Organic magnetic anions [TCNQ]˙−and [F4-TCNQ]˙−on graphene on Ru(0001) organize in two remarkably different patterns, as a result of the competition between the intermolecular repulsion and electron delocalization across neighboring molecules.