bluuebunny/crossref_metadata_2025_split huggingface dataset:
Compact microstrip bandpass filter using dual closed-loop stepped impedance resonator
Authors: Dembele Salif N. , Zhang Ting , Bao Jingfu , Bukuru Denis 
Published: March 2018

AbstractA dual closed-loop stepped impedance resonator (DCLSIR) is investigated and used in designing a compact microstrip bandpass filter (BPF). The proposed DCLSIR is symmetrical; as a result, the symmetric characteristics of the resonator have been used. The design equations are derived and used to support the circuit design. The center frequency, position of transmission zeros, and fractional bandwidth (FBW) are easily tuned by changing the physical dimensions of the resonator. Three transmission zeros are generated to improve the performance in the upper stopband. A DCLSIR prototype BPF is fabricated with a center frequency of 9.3 GHz, and evaluated to validate the design concept. The measured FBW is 9.25%, the insertion loss is 1.58 dB, and the return loss is over 17 dB. The measurement results agree well with the simulation results.
Increasing the bandwidth of cavity-backed SIW antennas by using stacked cavities
Authors: Ali Hiba Abdel , Massoni Enrico , Silvestri Lorenzo , Bozzi Maurizio , Perregrini Luca , Gharsallah Ali 
Published: March 2018

AbstractThis paper presents a technique to increase the bandwidth in substrate integrated waveguide (SIW) cavity-backed antennas, inspired by the design of cavity filters. The proposed structure consists of a slot antenna backed by two cavities, located one on top of the other and coupled through a slot. To demonstrate the bandwidth increase, a standard cavity-backed SIW antenna, with a rectangular slot etched in the top metal plane, has been designed, manufactured, and measured. Subsequently, a similar antenna was developed, by doubling the substrate thickness with the aim to improve the bandwidth. Finally, the new topology of two-cavity SIW antenna has been implemented and compared with the two previous ones. Simulation and experimental results show that the proposed two-cavity antenna exhibits a bandwidth twice as large as the standard SIW cavity-backed antenna.
Chemical modeling of internal photon-dominated regions surrounding deeply embedded HC/UCHII regions
Authors: Stéphan G. , Schilke P. , Le Bourlot J. , Schmiedeke A. , Choudhury R. , Godard B. , Sánchez-Monge Á. 
Published: March 2018

Aims. We aim to investigate the chemistry of internal photon-dominated regions (PDRs) surrounding deeply embedded hypercompact (HC) and ultracompact (UC) HII regions. We search for specific tracers of this evolutionary stage of massive star formation that can be detected with current astronomical facilities.
Methods. We modeled hot cores with embedded HC/UCHII regions (called HII region models in the article despite the fact that we do not model the HII region itself), by coupling the astrochemical code Saptarsy to a radiative transfer framework obtaining the spatio-temporal evolution of abundances as well as time-dependent synthetic spectra. In these models where we focused on the internal PDR surrounding the HII region, the gas temperature is set to the dust temperature and we do not include dynamics thus the density structure is fixed. We compared this to hot molecular core (HMC) models and studied the effect on the chemistry of the radiation field which is included in the HII region models only during the computation of abundances. In addition, we investigated the chemical evolution of the gas surrounding HII regions with models of different densities at the ionization front, different sizes of the ionized cavity and different initial abundances.
Results. We obtain the time evolution of synthetic spectra for a dozen of selected species as well as ratios of their integrated intensities. We find that some molecules such as C, N2H+, CN, and HCO do not trace the inner core and so are not good tracers to distinguish the HII/PDR regions to the HMCs phase. On the contrary, C+ and O trace the internal PDRs, in the two models starting with different initial abundances, but are unfortunately currently unobservable with the current achievable spatial resolution because of the very thin internal PDR (Δ rPDR < 100 AU). The emission of these two tracers is very dependent on the size of the HII region and on the density in the PDR. In addition, we find that the abundance profiles are highly affected by the choice of the initial abundances, hence the importance to properly define them.
Spectroscopic Parameters and atmosphEric ChemIstriEs of Stars (SPECIES)
Authors: Soto M. G. , Jenkins J. S. 
Published: March 2018

Context.The detection and subsequent characterisation of exoplanets are intimately linked to the characteristics of their host star. Therefore, it is necessary to study the star in detail in order to understand the formation history and characteristics of their companion(s).Aims.Our aims are to develop a community tool that allows the automated calculation of stellar parameters for a large number of stars, using high resolution echelle spectra and minimal photometric magnitudes, and introduce the first catalogue of these measurements in this work.Methods.We measured the equivalent widths of several iron lines and used them to solve the radiative transfer equation assuming local thermodynamic equilibrium in order to obtain the atmospheric parameters (Teff, [Fe/H], logg, andξt). We then used these values to derive the abundance of 11 chemical elements in the stellar photosphere (Na, Mg, Al, Si, Ca, Ti, Cr, Mn, Ni, Cu, and Zn). Rotation and macroturbulent velocity were obtained using temperature calibrators and synthetic line profiles to match the observed spectra of five absorption lines. Finally, by interpolating in a grid of MIST isochrones, we were able to derive the mass, radius, and age for each star using a Bayesian approach.Results.SPECIES obtains bulk parameters that are in good agreement with measured values from different existing catalogues, including when different methods are used to derive them. We find discrepancies in the chemical abundances for some elements with respect to other works, which could be produced by differences inTeff, or in the line list or the atomic line data used to derive them. We also obtained analytic relations to describe the correlations between different parameters, and we implemented new methods to better handle these correlations, which provides a better description of the uncertainties associated with the measurements.
Complex cyanides as chemical clocks in hot cores
Authors: Allen V. , van der Tak F. F. S. , Walsh C. 
Published: March 2018

Context. In the high-mass star-forming region G35.20−0.74N, small scale (~800 AU) chemical segregation has been observed in which complex organic molecules containing the CN group are located in a small location (toward continuum peak B3) within an apparently coherently rotating structure.
Aims. We aim to determine the physical origin of the large abundance difference (~4 orders of magnitude) in complex cyanides within G35.20−0.74 B, and we explore variations in age, gas/dust temperature, and gas density.
Methods. We performed gas-grain astrochemical modeling experiments with exponentially increasing (coupled) gas and dust temperature rising from 10 to 500 K at constant H2 densities of 107 cm−3, 108 cm−3, and 109 cm−3. We tested the effect of varying the initial ice composition, cosmic-ray ionization rate (1.3 × 10−17 s−1, 1 × 10−16 s−1, and 6 × 10−16 s−1), warm-up time (over 50, 200, and 1000 kyr), and initial (10, 15, and 25 K) and final temperatures (300 and 500 K).
Results. Varying the initial ice compositions within the observed and expected ranges does not noticeably affect the modeled abundances indicating that the chemical make-up of hot cores is determined in the warm-up stage. Complex cyanides vinyl and ethyl cyanide (CH2CHCN and C2H5CN, respectively) cannot be produced in abundances (vs. H2) greater than 5 ×10−10 for CH2CHCN and 2 ×10−10 for C2H5CN with a fast warm-up time (52 kyr), while the lower limit for the observed abundance of C2H5CN toward source B3 is 3.4 ×10−10. Complex cyanide abundances are reduced at higher initial temperatures and increased at higher cosmic-ray ionization rates. Reaction-diffusion competition is necessary to reproduce observed abundances of oxygen-bearing species in our model.
Conclusions. Within the context of this model, reproducing the observed abundances toward G35.20−0.74 Core B3 requires a fast warm-up at a high cosmic-ray ionization rate (~1 × 10−16 s−1) at a high gas density (>109 cm−3). The abundances observed at the other positions in G35.20-0.74N also require a fast warm-up but allow lower gas densities (~108 cm−3) and cosmic-ray ionization rates (~1 × 10−17 s−1). In general, we find that the abundance of ethyl cyanide in particular is maximized in models with a low initial temperature, a high cosmic-ray ionization rate, a long warm-up time (>200 kyr), and a lower gas density (tested down to 107 cm−3). G35.20−0.74 source B3 only needs to be ~2000 years older than B1/B2 for the observed chemical difference to be present, which maintains the possibility that G35.20−0.74 B contains a Keplerian disk.
The Lyman Alpha Reference Sample
Authors: Micheva Genoveva , Östlin Göran , Zackrisson Erik , Hayes Matthew , Melinder Jens , Guaita Lucia , Cannon John M. , Bridge Joanna S. , Kunth Daniel , Sandberg Andreas 
Published: March 2018

Context. The Lyman α Reference Sample (LARS) of 14 star-forming galaxies offers a wealth of insight into the workings of these local analogs to high-redshift star-forming galaxies. The sample has been well-studied in terms of Lyα and other emission line properties, such as H I mass, gas kinematics, and morphology.
Aims. We analyze deep surface photometry of the LARS sample in UBIK broadband imaging obtained at the Nordic Optical Telescope and the Canada-France-Hawaii Telescope, and juxtaposition their derived properties with a sample of local high-redshift galaxy analogs, namely, with blue compact galaxies (BCGs).
Methods. We construct radial surface brightness and color profiles with both elliptical and isophotal integration, as well as RGB images, deep contours, color maps, a burst fraction estimate, and a radial mass-to-light ratio profile for each LARS galaxy. Standard morphological parameters like asymmetry, clumpiness, the Gini and M20 coefficients are also obtained and analyzed, as well as isophotal asymmetry profiles for each galaxy. In this context, we compare the LARS sample to the properties of the BCG sample and highlight the differences.
Results. Several of these diagnostics indicate that the LARS galaxies have highly disturbed morphologies even at the level of the faintest outer isophotes, with no hint at a regular underlying population, as found in many BCG sample galaxies. The ground-based photometry reaches isophotes down to ~28 mag arcsec−2, while the space-based data reach only ~26 mag arcsec−2. The ground-based observations therefore reveal previously unexplored isophotes of the LARS galaxies. The burst fraction estimate suggests a spatially more extended burst region in LARS than in the BCGs. Comparison to stellar evolutionary models in color–color diagrams reveals complex behavior of the radial color profiles, often inconsistent with a single stellar population of any age and metallicity, but instead suggesting a mixture of at least two stellar populations with a typical young mass fraction in the range 0.1–1%.
Conclusions. The galaxies in the LARS sample appear to be in earlier stages of a merger event compared to the BCGs. Standard morphological diagnostics like asymmetry, clumpiness, Gini and M20 coefficients cannot separate the two samples, although an isophotal asymmetry profile successfully captures the average difference in morphology. These morphological diagnostics do not show any correlation with the equivalent width or the escape fraction of Lyman Alpha.
Advances in the Synthesis of Isatins: A Survey of the Last Decade
Authors: Bogdanov Andrei , Mironov Vladimir 
Published: March 2018

Isatin derivatives are widely used in organic synthesis, in medicinal chemistry and in the chemistry of materials. This report summarizes modern trends in the synthesis of substituted indolin-2,3-diones covering the literature from 2007 to 2017. Studies on the influence of the structure of substituents in the initial substrates on the formation of the heterocyclic isatin system and the yields of the target compounds are also discussed.1	Introduction2	Oxidation of Indole Derivatives3	Cyclization of o-Aminoacetophenones4	Cyclization of N-Acylanilines5	Miscellaneous6	Conclusion
Synthesis of C-Nor-D-homo-steroidal Alkaloids and Their Derivatives
Authors: Giannis Athanassios , Mousavizadeh Farnoush , Meyer Daniel 
Published: March 2018

The C-nor-D-homo-steroidal alkaloid cyclopamine was discovered in the 1969 and in 2000 it was shown to act as an inhibitor of the hedgehog signaling (Hh) pathway, which is aberrantly activated in some tumors. Subsequently it was revealed that this natural occurring alkaloid has also antidiabetic and antiviral properties. In this review we present syntheses of selected C-nor-D-homo-steroidal alkaloids and their analogues and also discuss a general access to C-nor-D-homo-steroids. Some historical as well as biomedical aspects are also presented.1	Introduction2	Total Synthesis of Cyclopamine2.1	Synthesis of exo-Cyclopamine and Further Cyclopamine Analogues2.2	Synthesis of a Carbacyclopamine Analogue3	D-Homocyclopamine: Saridegib (IPI-926)4	Synthesis of Nakiterpiosin5	Lewis Acid Mediated Nazarov Cyclization as a Versatile Method for C-Nor-D-homo-steroid Synthesis6	Conclusion
Systemische Behandlung des fortgeschrittenen differenzierten und medullären Schilddrüsenkarzinoms
Authors: Kreissl M.C. , Fassnacht M. , Mueller S.P. 
Published: March 2018

ZusammenfassungIn den vergangenen Jahren wurden drei neue Substanzen für die molekular gezielte Therapie des fortgeschrittenen und progredienten Schilddrüsenkarzinoms zugelassen: Vandetanib und Cabozantinib für das medulläre Schilddrüsenkarzinom sowie Sorafenib für das Radioiod-refraktäre differenzierte Schilddrüsenkarzinom. Die Selektion der Patienten durch ein interdisziplinäres Team sowie die Aufklärung der Patienten spielt eine wesentliche Rolle, wenn diese Behandlung in Betracht gezogen bzw. begonnen wird. Nur Patienten mit hoher Tumorlast und/oder symptomatischer bzw. progredienter Erkrankung, die lokalen Therapien nicht zugänglich ist, sollten behandelt werden. Um eine gute Lebensqualität zu erhalten, ist das Management der unerwünschten Arzneimittelwirkungen von größter Bedeutung. Aufgrund der Wirkweise der Tyrosinkinasehemmer ist der Verlauf der Tumormarker Calcitonin und Thyreoglobulin nur bedingt zur Beurteilung des Therapieansprechens und zum Follow-up geeignet, deshalb kommt der morphologischen und metabolischen Bildgebung besondere Bedeutung zu. Ein umschriebener oder geringer Progress sollte nicht unbedingt die Beendigung der Behandlung oder eine Therapieumstellung nach sich ziehen. In der nahen Zukunft werden weitere Substanzen verfügbar sein.Nachdruck aus und zu zitieren als: Nuklearmedizin 2015; 54: 88–93
Factor VII Activity Is an Independent Predictor of Cardiovascular Mortality in Elderly Women of a Sicilian Population: Results of an 11-year Follow-up
Authors: Noto D. , Barbagallo C. , Cefalu A. , Cavera G. , Sapienza M. , Notarbartolo A. , Davi’ G. , Averna M. 
Published: March 2018

SummaryThe aim of the Epidemiological project “Ventimiglia di Sicilia” is to identify the cardiovascular risk factors in a Sicilian population with a low risk profile and healthy nutritional habits. The risk of cardiovascular mortality in older subjects (over 60 years of age) is presented for an 11 year follow-up. Females showed higher prevalence of diabetes mellitus, hypertension, obesity and higher levels of total, LDL and HDL cholesterol, factor VII activity and fibrinogen compared to males. Cardiovascular mortality was related to hypertension and obesity in males, to high factor VII activity, obesity and diabetes mellitus in females. In a Logistic Regression model the same variables were independently correlated to cardiovascular mortality with the exception of obesity. In conclusion, these findings suggest that in a population with a low risk profile, other factors, such as factor VII activity, may emerge as predictors of cardiovascular mortality.
Prospective Study on Soluble Thrombomodulin and von Willebrand Factor and the Risk of Ischemic and Hemorrhagic Stroke
Authors: Jansson Jan-Håkan , Boman Kurt , Nilsson Torbjörn , Stegmayr Birgitta , Hallmans Göran , Johansson Lars 
Published: March 2018

SummaryThe aim of the present study was to examine if soluble thrombomodulin (sTM) and von Willebrand factor (VWF) could predict a first-ever ischemic or hemorrhagic stroke.This study was an incident case-referent study from within a population-based cohort in northern Sweden. Up to 1996 about 44,000 subjects had been screened and stroke cases were classified according to the WHO MONICA criteria. A first-ever stroke occurred in 108 cases. A total of 216 controls were selected from the same cohort.This prospective study found no association with sTM or VWF and the development of a first-ever ischemic stroke (n = 87) in the logistic regression model. For the hemorrhagic stroke cases (n = 18), the multivariate logistic regression model revealed a significant negative association with sTM. When dichotomized, the upper level (>17.3 µg/L) of sTM, as compared with the lower level (<17.3 µg/L), showed one fifth of the risk for hemorrhagic stroke (OR, 0.18; CI, 0.05 to 0.69). No significant association was found for VWF. We suggest that the novel finding of an inverse relation between sTM and hemorrhagic stroke should be investigated in a larger study.
Paradoxical Platelet Activation Was not Observed on Dissociation of Abciximab from GPIIb-IIIa Complexes
Authors: Ndoko Serge , Poujol Christel , Combrié Robert , Nurden Alan , Nurden Paquita 
Published: March 2018

SummaryThe ability of abciximab to bind and dissociate from platelets raises the question of the conformational state of GPIIb-IIIa complexes losing abciximab and the risk of paradoxical drug-induced platelet activation. Platelets incubated with abciximab and mixed in vitro with c7E3 Fab-free platelets lost the drug to the new platelets giving a single platelet population with a unimodal abciximab distribution within 17 h. Prelabeling the receiving platelets with phycoerythrin-labeled anti-GPIb monoclonal antibody (MoAb), permitted their identification by flow cytometry. Binding of PAC-1 and AP6, two MoAbs specific for activated GPIIb-IIIa, was then assessed to both losing and receiving platelet populations during transfer of abciximab. The subpopulation losing c7E3 Fab failed to show increased binding of these MoAbs. However, PAC-1 binding increased in both subpopulations after addition of ADP. Thus GPIIb-IIIa complexes are not in an activated state after dissociation of abciximab unless there is an additional source of activation.
Anticoagulant Effect at the Time of Epidural Catheter Removal in Patients Receiving Twice-daily or Once-daily Low-molecular-weight Heparin and Continuous Epidural Analgesia after Orthopedic Surgery
Authors: Kinnon Krystyna , Crowther Mark , Douketis James 
Published: March 2018

SummaryIn patients who receive co-administered low-molecular-weight heparin (LMWH) and continuous epidural analgesia (CEA) after orthopedic surgery, there is concern about an increased risk of a spinal epidural hematoma. The practice of twice-daily LMWH dosing in North America might, in part, account for the greater number of epidural hematomas reports compared to Europe where once-daily LMWH is used. We performed a prospective cohort study in patients who had orthopedic surgery and received co-administered LMWH and CEA. We investigated the trough anticoagulant effect, as measured by an anti-Xa heparin level, at the time of epidural catheter removal in patients who received twice-daily or once-daily LMWH. Twenty-five patients who received enoxaparin, 30 mg twice-daily, and 25 patients who received dalteparin, 5,000 IU once-daily, had anti-Xa heparin levels measured on the second or third post-operative day at the time of epidural catheter removal. In patients who received twice-daily enoxaparin, or once-daily dalteparin, the anti-Xa heparin level was measured, on average, 10.4 h and 21.8 h, respectively, after the preceding LWMH dose. All 25 patients who received once-daily LMWH had an anti-Xa heparin level <0.10 U/ml at the time of catheter removal. Of 25 patients who received twice-daily LMWH, the anti-Xa heparin level at the time of catheter removal was >0.20 U/ml in 5 patients (P = 0.050), and >0.10 U/ml in 7 patients (P = 0.009). We conclude that in patients who are receiving co-administered LMWH and CEA after orthopedic surgery, twice-daily but not once-daily LMWH administration is more likely to be associated with a clinically important anticoagulant effect at the time of epidural catheter removal.
Low Dose Oral Vitamin K to Reverse Acenocoumarol-induced Coagulopathy: A Randomized Controlled Trial
Authors: Crowther M. , Steidl L. , Ultori C. , Mera V. , Dentali F. , Squizzato A. , Marchesi C. , Venco A. , Ageno W. 
Published: March 2018

SummaryLow dose oral vitamin K rapidly reverses warfarin-associated coagulopathy. Its effect in patients receiving acenocoumarol is uncertain. We compared the effect of withholding acenocoumarol and administering 1 mg oral vitamin K with simply withholding acenocoumarol in asymptomatic patients presenting with INR values between 4.5 and 10.0. The primary end-point of the study was the INR value on the day following randomisation. We found that patients receiving oral vitamin K had more sub-therapeutic INR levels than controls (36.6% and 13.3%, respectively; RR 1.83, 95% confidence interval 1.16, 2.89) and a lower, but non-significant, proportion of INR values in range (50% and 66.6%, respectively) on the day following randomisation. After 5 ± 1 days, there were more patients with an INR value in range in the vitamin K group than in controls (74.1% and 44.8%, respectively). There were no clinical events during 1 month follow-up. We conclude that the omission of a single dose of acenocoumarol is associated with an effective reduction of the INR in asymptomatic patients presenting with an INR value of 4.5 to 10.0. Furthermore, the use of a 1 mg dose of oral vitamin K results in an excessive risk of overreversal of the INR.
Possible Synergy between Recombinant Factor VIIa and Prothrombin Complex Concentrate in Hemophilia Therapy
Authors: Christie Beverly , Henderson Nicole , Key Nigel , Nelsestuen Gary 
Published: March 2018

SummaryRecombinant factor VIIa (rFVIIa; Novoseven™) is used for treatment of hemophilia patients with inhibitors. There are poorly defined differences in clinical responsiveness between individuals. Prior to licensure in the United States, rFVIIa was available through the compassionate use program, during which two patients described in this study demonstrated an excellent response. More recently, one of these individuals showed a sub-optimal response to rFVIIa. One possible explanation for different treatment outcomes was sequential therapy with prothrombin complex concentrates (PCC) followed by rFVIIa in the compassionate use program. In support of this, an in vitro test showed that this patient had an exceptionally strong response to rFVIIa when it was added to whole blood after the patient received PCC therapy. Results with other patients supported this hypothesis. With further evaluation, a therapeutic approach combining sequential PCC and rFVIIa may prove useful for treatment of bleeding refractory to either agent used alone.