bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructural and Optoelectronic Properties of SiGe:H Films at the Transition Edge Fabricated by PECVD
Authors: Fan Shanshan , Guo Qiang , Wang Xinzhan , Yu Wei , Fu Guangsheng 
Published: July 2018

AbstractIn this study, hydrogenated silicon–germanium (SiGe:H) films with different hydrogen dilution ratios (Ds) are fabricated by the PECVD technique, and the microstructural and optoelectronic properties of the films are studied using Raman, XRD, FTIR, and photo/dark conductivity spectra. It is shown that, with the increase of D, protocrystalline hydrogenated silicon–germanium (proto‐SiGe:H) appears just below the transition edge, characterized by low void density and high photosensitivity, and nanocrystalline hydrogenated silicon–germanium (nc‐SiGe:H) appears above the transition edge with a low interface phase and a high number of crystalline grains, presenting high photoconductivity. The paracrystalline structural model is used to elucidate the structural and electronic properties of proto‐SiGe:H films. In the Raman spectra, the paracrystalline fraction ƒp, grain boundary fraction ƒGB, and crystalline fraction ƒc are the characteristic parameters of the protocrystalline and nanocrystalline SiGe:H films.
The distributed‐element to lumped‐element equivalence for transmission‐line filter synthesis
Authors: Xiao Fei 
Published: July 2018

SummaryFilters play an important role in frequency selection. However, to design transmission‐line filters such as microstrip filters is a very challenging task because of their distributed‐element effect. In this paper, the concept of the distributed‐element to lumped‐element equivalence is applied in the design of microstrip filters. The lumped‐element equivalent networks of some basic microstrip structures are presented and are applied to derive the whole lumped‐element equivalent networks of microstrip filters constituted by them. Then, the physical mechanism of microstrip filters is revealed, ie, how the resonances are created and coupled and how the transmission zeros are formed. The distributed‐element to lumped‐element equivalence relations between the electrical parameters of microstrip filters and the element values of their lumped‐element equivalent networks are derived. Through comparison between the lumped‐element equivalent networks of microstrip filters and those obtained by direct synthesis technique we recently proposed, initial structural parameters of microstrip filters can be calculated, which greatly simplifies their design. To verify it, several microstrip filter examples are presented for demonstration.
A novel relay selection algorithm using ant colony optimization with artificial noise for secrecy enhancement in cooperative networks
Authors: Shemi P.M. , Jibukumar M.G. , Sabu M.K. 
Published: July 2018

SummaryCooperative communication is one of the fastest growing research areas of today. It can efficiently mitigate the effect of shadowing and fading with the help of relays and proper relay selection technique. In this paper, a novel relay selection scheme combined with artificial noise (AN) is devised to enhance the secrecy of cooperative networks with amplify‐and‐forward scheme, over Rayleigh fading channels in the presence of a passive eavesdropper. The probability of path selection of ant colony optimization algorithm is used for selecting the best relay with high end‐to‐end signal‐to‐noise ratio. The probability of choosing a path depends on the significance of channel gain (G) and fading coefficients (h). The proposed algorithm finds the best relay in the following wireless scenarios: when (i) both channel gain and fading coefficients are significant; (ii) only fading coefficients are significant; and (iii) only channel gain is significant. Because the direct links between source and destination and source and eavesdropper are considered, AN along with the information is sent by both the source and the selected relay. The performance is evaluated based on secrecy rate (Rs); for the relays randomly placed between the source and destination and for different eavesdropper's location. The results show that the proposed relay selection scheme achieves better secrecy for different wireless scenarios compared with traditional schemes. With the help of AN, the secrecy rate can be made positive even when the eavesdropper lies near to source.
The off‐grid frequency selective millimeter wave channel estimation
Authors: Shakhsi Dastgahian Majid , Tehrani Mohammad Naseri , Khoshbin Hosein 
Published: July 2018

SummaryBroadband millimeter wave (mmW) systems are a promising pioneer of cellular communication for next generation which is utilizing the hybrid baseband/analog beamforming structures along with the miniature massive antenna arrays at both sides of the communication link. mmW channel with an available unlicensed spread spectrum is frequency selective because the signal bandwidth can be larger than the coherence bandwidth. Due to the sparse nature of mmW channel, extracting compressive sensing model of the system is preferable. In fact, exploiting the sparse structure will lead to the reduction of the computational complexity, because there is a reduction in the channel training length compared with the conventional methods such as least square estimation. Most of the prior works have considered on‐grid quantized departure/arrival angles in the input/output antennas to obtain a sparse virtual channel model. However, the sparse angles in the physical channel model are continuous where this continuity indicates a mismatch between the physical angles and the on‐grid angles. Such a mismatch will contribute to unwanted components in the virtual channel model. Given these extra components, the conventional compressive sensing tools are unable to recover the channel. In this paper, we propose two solutions for overcoming the problem caused by off‐grid angle selection. The first is based on the vector shaping, and the second one is based on the sparse total least square concepts. Simulation results demonstrate that the proposed methods both could obtain an adequate channel recovery and are preferable regarding computational complexity concerning the newly developed surrogate method.
Chromatolysis: Do injured axons regenerate poorly when ribonucleases attack rough endoplasmic reticulum, ribosomes and RNA?
Authors: Moon Lawrence David Falcon 
Published: July 2018

ABSTRACTAfter axonal injury, chromatolysis (fragmentation of Nissl substance) can occur in the soma. Electron microscopy shows that chromatolysis involves fission of the rough endoplasmic reticulum. In CNS neurons (which do not regenerate axons back to their original targets) or in motor neurons or dorsal root ganglion neurons denied axon regeneration (e.g., by transection and ligation), chromatolysis is often accompanied by degranulation (loss of ribosomes from rough endoplasmic reticulum), disaggregation of polyribosomes and degradation of monoribosomes into dust‐like particles. Ribosomes and rough endoplasmic reticulum may also be degraded in autophagic vacuoles by ribophagy and reticulophagy, respectively. In other words, chromatolysis is disruption of parts of the protein synthesis infrastructure. Whereas some neurons may show transient or no chromatolysis, severely injured neurons can remain chromatolytic and never again synthesize normal levels of protein; some may atrophy or die. Ribonuclease(s) might cause the following features of chromatolysis: fragmentation and degranulation of rough endoplasmic reticulum, disaggregation of polyribosomes and degradation of monoribosomes. For example, ribonucleases in the EndoU/PP11 family can modify rough endoplasmic reticulum; many ribonucleases can degrade mRNA causing polyribosomes to unchain and disperse, and they can disassemble monoribosomes; Ribonuclease 5 can control rRNA synthesis and degrade tRNA; Ribonuclease T2 can degrade ribosomes, endoplasmic reticulum and RNA within autophagic vacuoles; and Ribonuclease IRE1α acts as a stress sensor within the endoplasmic reticulum. Regeneration might be improved after axonal injury by protecting the protein synthesis machinery from catabolism; targeting ribonucleases using inhibitors can enhance neurite outgrowth and could be a profitable strategy in vivo. © 2018 Wiley Periodicals, Inc. Develop Neurobiol, 2018
The (Implicit) Dogmas of Business Rescue Culture
Authors: Verdoes Tim , Verweij Anthon 
Published: July 2018

AbstractIn this article, we challenge the (implicit) dogmas of the current trend towards a business rescue culture within Europe. It is unclear why this trend – as a logical consequence of the desire to create increasingly debtor friendly insolvency regimes – keeps revealing and reinforcing itself in this time frame. Many different approaches take this concept for granted. The idea thus risks becoming an end in itself. The assumptions behind the current trend of business rescue culture should reflect the stylized facts of a firm embedded in its business ecology. An implicit dogma of current business rescue culture is that a firm is an entity that must survive and will create value indefinitely and, accordingly, deserves a second chance. However, the ability to create value and therefore the viability of a firm are the outcome of an uncertain economic process. Capitalism is a process of trial and error. Failure is a normal outcome and should be considered an essential part of capitalism. In general, the life span of firms is finite because they have to cope with many uncertainties and trade‐offs. The firm itself is only a tiny temporary (legal) shell within a self‐organized value chain that continuously reallocates resources as competition intensifies and the rate of innovation accelerates. The implicit assumptions or dogmas of the current business rescue culture contradict the accelerating destructive forces of capitalism and therefore can be labelled as an anachronism. Instead of focusing on the specific micro‐level of the firm, insolvency regimes should aim to provide a solution at the higher meso‐level. Copyright © 2018 The Authors International Insolvency Review published by INSOL International and John Wiley & Sons, Ltd.
Fluorination‐controlled Aggregation and Intermolecular Interactions in Pt(II) Complexes with Tetradentate Luminophores
Authors: Wilde Sebastian , González‐Abradelo Darío , Daniliuc Constantin‐Gabriel , Böckmann Marcus , Doltsinis Nikos L. , Strassert Cristian A. 
Published: July 2018

AbstractIn this work we describe the synthesis and DFT‐supported photophysical characterization of a series of Pt(II) complexes bearing tetradentate luminophores with increasing degree of fluorination. Aggregation into crystalline phases leads to substitution‐dependent arrangements that in all cases hinder intermetallic coupling, as intermolecular interactions are dominated by hydrogen bonding and π‐stacking. In amorphous matrices, on the other hand, we observed that an increasing level of fluorination favors the tendency towards Pt−Pt interaction upon aggregation, leading to a red‐shifted phosphorescence, if compared with monomeric species in dilute solutions and crystalline solids.
Investor sentiment and industry returns
Authors: Molchanov Alexander , Stangl Jeffrey 
Published: July 2018

AbstractThis paper investigates the interaction between investor sentiment and industry performance. Investor sentiment has a widespread and systematic effect on performance, and predicts short‐term mispricing at industry level. Predictable long‐term reversals are weaker. We find limited evidence of cross‐sectional industry differences. Moreover, there is no relationship between investor sentiment and industry characteristics that proxy valuation uncertainty. Results generally show that investor sentiment has a market‐wide effect, questioning merit of industry timing strategy based on sentiment.
A test of general asymmetric dependence
Authors: Jiang Lei , Maasoumi Esfandiar , Pan Jiening , Wu Ke 
Published: July 2018

SummaryWe propose a modified mutual information measure to capture general asymmetric dependence between two random variables. Based on this measure, we propose a test of asymmetric dependence and examine its finite‐sample performance. We show that our test has better power than competing tests with alternative dependence measures. Using the new test, we find significant asymmetric dependence in returns of commonly used stock portfolios and the market return both in the US and other developed countries. Further, the dependence between developed country markets and the US market is stronger when both markets are in a downturn.
An updated weight of evidence approach for deriving a health‐based guidance value for 4‐nonylphenol
Authors: Li Xiaomeng , Huo Jiao , Liu Zhaoping , Yue Qianlan , Zhang Lishi , Gong Yunyun , Chen Jinyao , Bao Huihui 
Published: July 2018

Abstract4‐Nonylphenol (NP) is a persistent estrogen‐active compound. Human exposure to NP is primarily through water and food. Although risk assessments of NP have been conducted by the European Union and a few other countries, only the Danish Veterinary and Food Administration, in 2000, proposed a tolerable daily intake of 0.005 mg kg−1 body weight (bw) day−1. New data have been accumulated since then, prompting an update on the risk assessment of NP. A weight of evidence approach is recommended for use in scientific assessments by several agencies, e.g., European Food Safety Authority, etc. Based on the results of a weight of evidence approach, two methods were used to derive the health‐based guidance value (HBGV) for NP in this study, namely a no observed adverse effects level/lowest observable adverse effect level method, and a benchmark dose method. Considering the considerable uncertainty of benchmark dose model fitting of the available data, a tolerable daily intake value of 0.025 mg kg−1 bw day−1 was derived as a provisional HBGV for NP based on the lowest observable adverse effect level value of 15 mg kg−1 bw day−1 of the renal toxicity in rats, together with the uncertainty factor of 600. However, the HBGV of NP still needs further investigation.
Reversible cholinesterase inhibitors as pretreatment for exposure to organophosphates. A review
Authors: Lorke Dietrich E. , Petroianu Georg A. 
Published: July 2018

AbstractOrganophosphorus compounds (OPCs), inhibitors of acetylcholinesterase (AChE), are useful agents as pesticides, but also represent a serious health hazard. Standard therapy with atropine and established oxime‐type enzyme reactivators (pralidoxime, obidoxime) is unsatisfactory. Better therapeutic results are obtained, when reversible AChE inhibitors are administered before OPC exposure. This review summarizes the history of such a pretreatment approach and sums up a set of experiments undertaken in search of compounds that are efficacious when given before a broad range of OPCs. The prophylactic efficacy of 10 known AChE inhibitors, either already used clinically for different indications (physostigmine, pyridostigmine, ranitidine, tiapride, tacrine, amiloride, metoclopramide, methylene blue) or developed for possible therapeutic use in the future (7‐methoxytacrine, K‐27) was compared, when administered before exposure to six chemically diverse OPCs in the same experimental setting: ethyl‐paraoxon, methyl‐paraoxon, diisopropylfluorophosphate, terbufos sulfone, azinphos‐methyl and dicrotophos. The experimental oxime K‐27 was the most efficacious compound, affording best protection, when administered before terbufos sulfone, azinphos‐methyl and dicrotophos, second best before ethyl‐ and methyl‐paraoxon exposure and third best before diisopropylfluorophosphate administration. This ranking was similar to that of physostigmine, which was superior to the Food and Drug Administration‐approved pretreatment for soman with pyridostigmine. Tiapride, amiloride, metoclopramide, methylene blue and 7‐methoxytacrine did not achieve protection. No correlation was observed between the IC50 of the reversible AChE inhibitors and their protective efficacy. These studies indicate that K‐27 can be considered a very promising broad‐spectrum prophylactic agent in case of imminent organophosphate exposure, which may be related to its AChE reactivating activity rather than its AChE inhibition.
Six‐Transmembrane Epithelial Antigen of the Prostate‐1 (STEAP‐1)–Targeted Ultrasound Imaging Microbubble Improves Detection of Prostate Cancer In Vivo
Authors: Yuan Yun , Liu Ying , Zhu Xiang‐Ming , Hu Jing , Zhao Chen‐Yang , Jiang Feng 
Published: July 2018

PurposeTo investigate the feasibility of the 6‐transmembrane epithelial antigen of the prostate‐1 (STEAP‐1)–targeted microbubbles for enhancing ultrasound imaging of prostate tumors in the nude mouse xenograft models.MethodsContrast agents were established by conjugating biotinylated STEAP‐1 monoclonal antibodies with streptavidin coated SonoVue microbubbles. Then, ordinary SonoVue (Bracco, Milan, Italy) microbubble and STEAP‐1–targeted SonoVue microbubble were used, respectively, for contrast‐enhanced sonography to detect prostate tumors in the nude mouse xenograft models. The characteristics, including peak intensity, time to peak, area under the curve, and mean transit time, were measured.ResultsThe biological characteristics of STEAP‐1–targeted SonoVue microbubbles were stable. STEAP‐1–targeted SonoVue microbubbles can successfully conjugate to prostate cancer cell lines in vitro. Enhancement of ultrasound signal intensity was determined after injection of STEAP‐1–targeted SonoVue microbubble, compared with ordinary SonoVue microbubble. Higher intensities of ultrasound signals in xenograft tumor of prostate cancer were associated with increased levels of STEAP‐1 expression.ConclusionOur results suggest that SonoVue microbubble carrying STEAP‐1 monoclonal antibody could improve the ultrasound visualization of prostate cancer and identify the tumor more effectively in vivo. A prospective study is required to validate our finding in patients with prostate cancer.
Shear Wave Elastography in the Evaluation of the Kidneys in Pediatric Patients with Unilateral Vesicoureteral Reflux
Authors: Kalyoncu Ucar Ayse , Cicek Rumeysa Yasemin , Alis Deniz , Akbas Serkan , Arioz Habibi Hatice , Arslan Mine Usta , Eral Gokalp , Suleyman Ayse , Caliskan Salim , Adaletli Ibrahim 
Published: July 2018

ObjectivesTo evaluate the ability of shear wave elastography (SWE) to detect renal parenchymal scar formation in patients with vesicoureteral reflux.MethodsWe prospectively evaluated 49 patients with unilateral grade 2 or higher‐degree VUR. All patients underwent dimercaptosuccinic acid (DMSA) scintigraphy for evaluation of the renal parenchymal scar. After the DMSA scan, 2 radiologists, who were blinded to clinical data and each other's measurements, evaluated the kidneys of the patients using SWE. The kidneys were divided into 3 parts: upper pole, middle region, and lower pole, and 3 regions of interest were placed to each part. Shear wave velocity (SWV) values were calculated using meters per second as a unit and recorded for each region. Afterward, SWV values were compared to DMSA results.ResultsThere was no significant difference between the observers' mean SWV values of kidneys with VUR without scar formation (mean ± SD, 2.11 ± 0.06 and 2.09 ± 0.05 m/s) and the contralateral normal kidney SVW values (2.11 ± 0.06 and 2.10 ± 0.05 m/s; P = .936 and .724, respectively). We observed a significant difference between the mean SWV values of the kidneys with VUR accompanied by scar formation (2.28 ± 0.10 and 2.27 ± 0.11 m/s) and the mean SWV values of the contralateral normal kidneys (2.09 ± 0.05 and 2.10 ± 0.04 m/s; P < .001 for both observers).ConclusionsShear wave elastography could detect scar tissue in kidneys; however, the variability of the stiffness due to the kidney's complex structure, and variations in blood perfusion and the glomerular filtration rate of the kidney might limit the use of SWE in current clinical diagnostic algorithms for VUR.
Diagnostic Value of Transthoracic Echocardiography Combined With Contrast‐Enhanced Ultrasonography in Mediastinal Masses
Authors: Wang Ding , Zhang Jun , Liu Yani , Sun Ruiying , Tian Jie , Zhao Wei , Deng Youbin 
Published: July 2018

ObjectivesMultiple types of mediastinal masses, especially masses in the anterior mediastinum, may be encountered in routine echocardiographic examinations for symptomatic or asymptomatic patients. The aim of this study was to evaluate the diagnostic value of transthoracic echocardiography combined with contrast‐enhanced ultrasonography in determining the location, composition, and vascularization of mediastinal masses.MethodsA retrospective analysis was conducted on 48 consecutive patients who first had a diagnosis of mediastinal masses by echocardiography. The location of the mass, tissue components, and relationships with the heart and great vessels were analyzed on the basis of multiple transthoracic echocardiographic views. Further contrast‐enhanced ultrasonography was performed to determine the vascularization of masses in 25 patients. The clinical, computed tomographic, and histopathologic findings were all recorded and analyzed.ResultsThe localization, ultrasonographic characteristics of the mass, degree of vascularization, and relationships with the heart and great vessels assessed on echocardiography allowed a correct diagnosis in most of the cases.ConclusionsTransthoracic echocardiography is a useful method for diagnosing mediastinal. Further contrast‐enhanced ultrasonography could provide more details on the degree of vascularization, which could facilitate accurate diagnosis and differentiation diagnosis.
Oriented Overgrowths of Poly(l‐Lactide) on Oriented Isotactic Polypropylene: A Sequence of Soft and Hard Epitaxies
Authors: Guan Guangwu , Zhang Jie , Sun Xiaoli , Li Huihui , Yan Shouke , Lotz Bernard 
Published: July 2018

AbstractThe crystallization behavior of an amorphous poly(l‐lactide) (PLLA) layer deposited on uniaxially oriented isotactic polypropylene (iPP) substrate is been studied by atomic force microscopy (AFM) and electron microscopy combined with electron diffraction. A patterned PLLA structure with two fixed lamella and chain orientations is observed. Electron diffraction demonstrates that the major lamellar set is oriented with molecular chains perpendicular to the chain direction of the iPP. The minor lamellar set is inclined at ≈64° to both the iPP chain axis direction and the lamellae of the major set as judged from both the bright field electron micrograph and the AFM image. The orientation of the main set is explained in terms of “soft” epitaxy or graphoepitaxy, in which PLLA chains oriented parallel to the ditches of the iPP substrate caused by alternatively arranged crystalline and amorphous regions. The minor set is due to a homoepitaxy of PLLA with parallelism of the helical paths. The orientation of this minor set of lamellae therefore depends on and can help determine the chirality—l or d—of the PLA investigated.