bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual branches network for image super‐resolution
Authors: Matsune Ai , Cheng Guoan , Zhan Shu
Published: September 2019

Recent studies have shown that deep convolutional neural networks (CNNs) significantly boosted the performance of single‐image super‐resolution (SISR). In this Letter, the authors present a novel dual branches network (DBN) for SISR. Different from traditional CNN, the authors' DBN utilises the benefits of the residual structure and the densely connected structure together. Their key strategy is to divide the input path of the network into dual branches: a residual branch and a dense branch. This dual branches structure reuses valuable features and explores new features effectively. Experimental comparisons demonstrated the high ability of their DBN over the state‐of‐the‐art framework for SISR with alleviating blurs of output images.
Wideband circularly polarised patch antenna with multi‐section λ/4 transmission lines
Authors: Wu Qiong‐Sen , Zhang Xiao , Zhu Lei , Zhang Gary
Published: September 2019

A wideband circularly polarised patch antenna with multi‐section λ/4 transmission lines is proposed. The multi‐section lines are directly connected to the patch radiator. The feeding circuit and patch are on the same layer, which makes it easy for integration. There is no coupling structure, and consequently, the parasitic radiation from the feeding circuit can be minimised. The whole antenna structure is designed according to the traditional filter design theory. Two minima in the axial ratio response come up to achieve wideband characteristic. Finally, the proposed antenna structure and wideband performances are experimentally verified by an antenna prototype.
Markovian jump system approach for the estimation and adaptive diagnosis of decreased power generation in wind farms
Authors: Sales‐Setién Ester , Peñarrocha‐Alós Ignacio
Published: September 2019

In this study, a Markovian jump model of the power generation system of a wind turbine is proposed and the authors present a closed‐loop model‐based observer to estimate the faults related to energy losses. The observer is designed through an ‐based optimisation problem that optimally fixes the trade‐off between the observer fault sensitivity and robustness. The fault estimates are then used in data‐based decision mechanisms for achieving fault detection and isolation. The performance of the strategy is then ameliorated in a wind farm (WF) level scheme that uses a bank of the aforementioned observers and decision mechanisms. Finally, the proposed approach is tested using a well‐known benchmark in the context of WF fault diagnosis.
Dissipativity‐based fault estimation for switched non‐linear systems with process and sensor faults
Authors: Han Jian , Liu Xiuhua , Wei Xinjiang , Zhang Huifeng , Hu Xin
Published: September 2019

This study investigates the fault estimation problem for switched non‐linear systems, which have process fault and sensor fault. The Takagi–Sugeno fuzzy models are applied to construct the non‐linear dynamics in switched non‐linear systems. A novel fault estimation observer, which has an adjustable dimension, is designed to estimate the system state, process fault, and sensor fault, simultaneously. In the observer design process, only the input and output are used, and the differential of the output is not needed. Under an arbitrary switching signal, sufficient conditions can be achieved to ensure that the estimation error dynamic is strict ‐ ‐dissipative, and the poles of the error system located in a given region. Finally, the simulation examples are provided to verify the proposed method.
Application of fuzzy multiplexing of learning Gaussian processes for the interval forecasting of wind speed
Authors: Alamaniotis Miltiadis , Karagiannis Georgios
Published: September 2019

Robust forecasting of wind speed values is a key element to effectively accommodate renewable generation from wind in smart power systems. However, the stochastic nature of wind and the uncertainties associated with it impose high challenge in its forecasting. A new method for forecasting wind speed in renewable energy generation is introduced in this study. The goal of the method is to provide a forecast in the form of an interval, which is determined by a mean value and the variance around the mean. In particular, the forecasting interval is produced according to a two‐step process: in the first step, a set of individual kernel modelled Gaussian processes (GP) are utilised to provide a respective set of interval forecasts, i.e. mean and variance values, over the future values of the wind. In the second step, the individual forecasts are evaluated using a fuzzy driven multiplexer, which selects one of them. The final output of the methodology is a single interval that has been identified as the best among the GP models. The presented methodology is tested on the set of real‐world data and benchmarked against the individual GPs as well as the autoregressive moving average model.
MIMO radar techniques: two‐stage constant false alarm rate detection for fast‐fluctuating targets
Authors: Li Zhihua , Su Hongtao , Hu Qinzhen , Zhou Shenghua
Published: September 2019

Here, the authors analyse a two‐step constant false alarm rate (CFAR) detection problem in distributed sensor system (e.g. statistical multiple‐input multiple‐output ( MIMO) radar) for fast‐fluctuating targets (TS‐AMF‐II). The scheme arises when a data rate restriction forces each of the distributed systems to censor their detection statistics before sharing and is motivated by the fact that the clutter plus noise power and the signal to clutter plus noise ratio may be both unknown in practice. The proposed detector has two thresholds: the first one called local threshold controls the communication rate and the second one called global threshold adjusts the global probability of false alarm. Numerical results illustrate that the proposed detector has good detection performance at a low communication rate.
Novel broadband design of SIW directional coupler
Authors: Wang Jia , Ling Tianqing
Published: September 2019

To enable broadband characteristic, a novel type of directional coupler based on slot coupling theories is proposed. Besides, this directional coupler is designed on the basis of substrate integrated waveguide. Strong coupling directional couplers are proposed and simulated with different coupling degrees −3, −5, and −7 dB. From the simulated results, it illustrates that these couplers show low return loss under −20 dB and high isolation above 20 dB in the frequency of X band. The results also show good performances with ∼30.8% FBW for −3 dB (±0.3 dB) coupling degree, 29.9% FBW for −5 dB (±0.5 dB) coupling degree, and 36.8% FBW for −7 dB (±0.7 dB) coupling degree. It is easy to integrate in microwave and millimetre‐wave integrated system because of the characteristics of planar form and compact size of SIW directional couplers.
Method for TDOA localisation in over‐the‐horizon environments
Authors: Liu Jian‐Xin , Mao Xing‐Peng
Published: September 2019

Here, the authors propose a new over‐the‐horizon time‐difference‐of‐arrival localisation model based on the ground‐wave and simultaneously put forward a modified semi‐definite programming algorithm, which is called Ground‐wave semi‐definite programming (G‐SDP). If both the target and the base stations are on the surface of the earth and far away from each other, the propagation path of the signal is a curve along the surface instead of a straight line, thus making the traditional positioning model inefficient. To overcome the problem, they develop a novel localisation model and explore a priori information to achieve improvements on SDP algorithms. An iteration trick is also utilised to obtain better performance when the signal‐to‐noise ratio is low. The simulation results show the merits of the improved model and G‐SDP.
Persymmetric subspace adaptive detection and performance analysis
Authors: Gao Yongchan , Ji Hongbing , Zhang Nan , Zuo Lei
Published: September 2019

This study deals with the problem of detecting a subspace signal in coloured Gaussian noise, where the subspace signal belongs to a known subspace, but with unknown coordinates. The authors exploit the persymmetric structure of the covariance matrix by a unitary transform and then devise a persymmetric subspace detector based on two‐step design procedure. By exploiting the persymmetric structure of the covariance matrix, the proposed detector can reduce training data requirements. Additionally, approximate expressions for the probabilities of false alarm and detection of the proposed detector are derived. Numerical results demonstrate that the proposed detector can offer significantly enhanced detection performance in comparison with the conventional counterparts when the amount of training data is limited.
Target characteristics analysis for a shipborne HF surface wave radar
Authors: Lu Geriletu , Ji Yonggang , Wang Yiming , Liu Yongxin
Published: September 2019

In this study, based on the shipborne high‐frequency (HF) surface wave radar target detection application, the first‐order ocean surface cross‐section for the shipborne HF surface wave radar is simulated, and the relationship between the sea clutter widening characteristics and platform speed is analysed. Then, the relationship between the target echo characteristics of shipborne HF surface wave radar with the platform speed and sails direction is analysed. Finally, combined with the characteristics of the target and sea clutter, a new scheme of target detection for the shipborne radar is proposed. That is, by changing the course of the shipborne platform motion, the target is separated from the widened sea clutter, thereby improving the target‐detection performance of the shipborne HF surface wave radar.
Deceptive jamming against multi‐channel SAR‐GMTI
Authors: Zhang Jingke , Qi Zongfeng , Zeng Yonghu , Wang Liandong
Published: September 2019

Aimed at the problem that the deceptive jamming against synthetic aperture radar ground moving target indication generated by single jammer cannot work effectively in multi‐channel SAR, a novel deceptive jamming against multi‐channel SAR‐GMTI based on two jammers is studied. First, signal model of the novel deceptive jamming is built. Then, based on three‐channel clutter suppression and interferometry processing, the amplitude and interferometric phase of deceptive moving target generated by the novel deceptive jamming are derived. Last, simulation experiment validates that the novel deceptive jamming can generate false moving targets with the controllable radial velocity and located azimuth position in the multi‐channel SAR.
Preparation and characterisation of two‐dimensional magnetic chitosan nanosheets for removal of azo dyes from aqueous solutions
Authors: Peng Xiuying , Jia Wanxin , Lu Dongtao , Zhang Qiao , Yang Cheng , Shuang Shaomin , Guo Yujing , Dong Chuan
Published: September 2019

In this work, two‐dimensional magnetic chitosan nanosheets (CSMNSs) for azo dye adsorption were successfully synthesised by a simple hydrothermal method. The as‐prepared CSMNSs was characterised by scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and vibrating sample magnetometer. Then, the CSMNSs as the dye adsorbent were applied to the removal of two kinds of azo dyes (methyl orange and amido black). The effect of solution pH and adsorbent dosage, adsorption isotherm, adsorption kinetics and the reusability of CSMNSs were examined. Adsorption isotherms obeyed Freundlich model and adsorption kinetics was described as pseudo‐second‐order model. Furthermore, the CSMNSs have the advantage of simple synthesis route, high absorption efficiency, rapid magnetic separation from aqueous solutions and excellent reusability. The CSMNSs as the dye adsorbent was applied to removal of azo dyes with broad prospects.
In‐situ microcalorimetry study on thermodynamic functions of Cu2 O nanocubes
Authors: He Zijun , Tang Huanfeng , Huang Zaiyin
Published: September 2019

Four different sizes of cuprous oxides (Cu2 O) nanocubes in the range of 40–120 nm were synthesised by liquid phase reduction method. The morphology, size, and structure of synthesised Cu2 O nanocubes were characterised by scanning electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. In‐situ microcalorimetry was used to calculate the conventional and surface thermodynamic functions of Cu2 O nanocubes by combining thermodynamic principles and transition state theory. The effect of particle size on conventional thermodynamic functions and surface thermodynamic functions were investigated and analysed, whose results were supported by the established thermodynamic models. Results showed that both the standard molar enthalpy of formation and the standard molar entropy of formation were increased with decreasing particle size, while the standard molar Gibbs energy of formation decreased. Also, the molar surface Gibbs energy, molar surface enthalpy, and molar surface entropy grew with the reduction of particle size, which correlated well with the models. Such a property is of scientific significance for enriching and developing disciplines such as surface physics and surface thermodynamics.
The last pieces of the primitive inner belt puzzle: Klio, Chaldaea, Chimaera, and Svea
Authors: Morate David , de León Julia , De Prá Mário , Licandro Javier , Pinilla-Alonso Noemí , Campins Humberto , Arredondo Anicia , Carvano Jorge Marcio , Lazzaro Daniela , Cabrera-Lavers Antonio
Published: September 2019

Aims.Several primitive families in the inner region of the main asteroid belt were identified as potential sources for two near-Earth asteroids (NEAs), (101955) Bennu and (162173) Ryugu, targets of the sample-return missions OSIRIS-REx and Hayabusa2, respectively. Four of the families, located at high proper inclinations (i> 10°), have not yet been compositionally studied: Klio, Chaldaea, Chimaera, and Svea. We want to characterize and analyze these families within the context of our PRIMitive Asteroid Spectroscopic Survey (PRIMASS), in order to complete the puzzle of the origins of the two NEAs.

Methods.We obtained visible spectra (0.5–0.9μm) of a total of 73 asteroids within the Klio, Chaldaea, Chimaera, and Svea collisional families, using the instrument OSIRIS at the 10.4 m Gran Telescopio Canarias. We performed a taxonomical classification of these objects, and an analysis of the possible presence of absorption bands related to aqueous alterations, comparing the results with already studied primitive families in the inner main belt.

Results.We present here reflectance spectra for 30 asteroids in the Klio family, 15 in Chaldaea, 20 in Chimaera, and 8 in Svea. We show that Klio, Chaldaea, and Chimaera members have moderately red spectral slopes, with aqueous alteration absorption bands centered around 0.7μm, characteristic of the group of primitive families known as Erigone-like. In contrast, Svea shows no 0.7μm features, and neutral and blue spectral slopes, and thus is a Polana-like family. While all four families might be related to (162173) Ryugu, the only family studied in this work that might be related to (101955) Bennu is Svea.
Fast-modulation imaging with the self-coherent camera
Authors: Martinez P.
Published: September 2019

Context. Direct detection of exoplanets requires imaging in a highly dynamic range and exquisite image quality and stability. Wavefront error (atmospheric errors, manufacturing errors on optics, cophasing residuals, temperature variations, etc.) will limit the efficiency of this endeavor by creating various flavors of speckles that evolve with different timescales. Active wavefront-error correction using a deformable mirror requires measuring the wavefront aberrations in the science image with high accuracy and in a shorter time than the duration of the dominant speckle lifetime.

Aims. The self-coherent camera (SCC) is a focal plane wavefront sensor exploiting the coherence of light to generate Fizeau fringes in the image plane to spatially encode speckles. The SCC combines a coronagraph and a modified Lyot stop to which a reference channel is added. The conventional SCC is restricted to long-exposure measurements because the light transmitted through the reference channel is limited. The SCC can correct quasi-static aberrations but precludes short-lived atmospheric aberrations from the measurement.

Methods. I propose an alternative to the conventional SCC that I call the fast-modulated SCC. It uses a simplified Lyot stop design and an adequate Fourier filtering algorithm. The theory is established and confirmed by means of numerical simulations.

Results. The SCC theory dictates that the separation between the classical Lyot stop and the reference channel must be larger than 1.5 times the Lyot stop diameter. The fast-modulated SCC allows for the reference channel to be placed anywhere, in particular in the vicinity of the pupil where the maximum of diffracted light is found. This alternative represents a complete game changer for the sensor: full compatibility with any type of coronagraph, easy installation in existing instruments, and versatility by accessing short- and long-time exposure measurements.

Conclusions. While the conventional SCC can almost not be implemented in existing instruments because the optical beam footprint in the instrument must be wide enough to illuminate the reference channel, which is often seen as a significant shortcoming, the fast-modulated SCC does not require any constraint on this. The fast-modulated SCC also relaxes the high sampling requirement to resolve the fringes, which is usually incompatible with the observation of fainter targets because the fringes are larger. The fast-modulated SCC simultaneously counteracts the two original shortcomings of the SCC concept.
Narzissmus oder kein Narzissmus?
Authors: Lammers Claas-Hinrich
Published: September 2019

Narzissmus ist in aller Munde. Häufig dient dies der Charakterisierung unbequemer Mitmenschen, ohne dass der Gebrauch gerechtfertigt wäre. Wo hört das gesunde
Streben nach Selbstwert auf und wo fängt der krankhafte Narzissmus an? Unterschiedliche Verwendungen in der Psychologie und der Psychiatrie spiegeln die
unpräzise Definition wieder. Die geplante Abschaffung im DSM-V und realisierte Abschaffung in der ICD-11 setzen weitere Fragezeichen.
Gestational Weight Gain Particularly Affects the Risk of Large for Gestational Age Infants in Non-obese Mothers
Authors: Weschenfelder Friederike , Lehmann Thomas , Schleussner Ekkehard , Groten Tanja
Published: September 2019

Introduction The birth of a large for gestational age (LGA) infant is a significant risk factor for birth complications and maternal morbidity and an even higher risk factor for offspring obesity, metabolic syndrome and cardiovascular disease in later life. Relevant factors affecting the risk of delivering an LGA infant are maternal pre-gravid obesity, excessive gestational weight gain exceeding the recommendations of the Institute of Medicine (IOM) and diabetes in pregnancy. We aimed to determine what matters most in terms of the risk of fetal overgrowth.

Materials and Methods We performed a database analysis of 12 701 singleton term deliveries documented in our university hospital birth registry from 2003 to 2014. Multivariate logistic regression analysis was used to determine the adjusted odds ratios.

Results Excessive weight gain had the strongest impact on LGA (OR: 1.249 [95% CI: 1.018 – 1.533]) compared to maternal pre-gravid body mass index (BMI) (OR: 1.083 [95% CI: 1.066 – 1.099]) and diabetes (OR: 1.315 [95% CI: 0.997 – 1.734]). Keeping gestational weight gain within the recommendations of the IOM resulted in a risk reduction for LGA of 20% (OR: 0.801 [95% CI: 0.652 – 0.982]). The risk for LGA increases by 6.9% with each kg weight gain. Normal weight women (BMI 18.5 – 24.9 kg/m2) and moderately overweight women (BMI 25 – 29.9 kg/m2) showed the highest increase in LGA rates per kg weight gain during pregnancy (OR: 1.078 [95% CI: 1.052 – 1.104] and OR: 1.058 [95% CI: 1.026 – 1.09], resp.). Only in underweight (< 18.5 kg/m2) and normal weight women the risk of LGA birth is strongly influenced by diabetes (OR 11.818 [95% CI: 1.156–120.782] and 1.564 [95% CI: 1.013–2.415]).

Conclusion Excessive weight gain is particularly important for non-obese women. These women are therefore a target cohort for intervention, as each prevented additional kilogram weight gain reduces the risk of LGA by more than 5%.
Recyclable Heterogeneous Copper(II)-Catalyzed Oxidative Cyclization of 2-Pyridine Ketone Hydrazones Towards [1,2,3]Triazolo[1,5-a]pyridines
Authors: Jiang Gan , Lin Yang , Cai Mingzhong , Zhao Hong
Published: September 2019

The heterogeneous copper(II)-catalyzed oxidative cyclization of 2-pyridine ketone hydrazones was achieved in ethyl acetate at room temperature in the presence of an MCM-41-anchored bidentate 2-aminoethylamino copper(II) catalyst [MCM-41-2N-Cu(OAc)2], in the presence of air as the oxidant, yielding a wide variety of [1,2,3]triazolo[1,5-a]pyridines in mostly good to high yields. The present method was also applied to the direct one-pot synthesis of [1,2,3]triazolo[1,5-a]pyridines from 2-acylpyridine derivatives and hydrazine monohydrate. Importantly, this supported copper(II) catalyst could be conveniently obtained via a simple procedure from easily available and inexpensive reagents, recovered by filtration of the reaction mixture, and reused at least seven times without a significant loss of catalytic activity.
Number of Dental Stem Cells on Root Canal Dentin after Application of Triple Antibiotic Paste or Calcium Hydroxide: An In Vitro Study
Authors: Gougousis Konstantinos , Giannakoulas Dimitrios G. , Taraslia Vasiliki , Agrafioti Anastasia , Anastasiadou Ema , Kontakiotis Evangelos G.
Published: September 2019

Objective The aim of this study was to evaluate the viability of stem cells from exfoliated and deciduous teeth (SHED) on dentin surface treated with triple antibiotic paste or calcium hydroxide.

Materials and Methods Nine single-rooted extracted premolars were prepared appropriately and divided into three groups. In group A, the root canals were left empty, a triple antibiotic paste was placed in the root canals of group B, and calcium hydroxide was placed in the root canals of group C. After 1 week, the intracanal medicaments were removed, and stem cells were seeded on the treated surface of the specimens for 1 more week. The cells were stained and then observed under confocal microscope over the entire surface of each test material. Counting of the cells was made by Image J (3D) software, as well as manually.

Statistical Analysis To investigate any statistically significant differences between the experimental groups, statistical tests including Kruskal–Wallis and Mann–Whitney U-test were performed. Significance level was set to P < 0.05, and all analyses were performed with SPSS IBM program, v. 21.

Results Groups B and C showed statistically significantly higher number of cells compared to Group A, whereas cells developed in a substrate of calcium hydroxide residues appeared in majority with distinct cores and widened unlike other groups.

Conclusions The effect of calcium hydroxide manifested better results regarding the number of stems cells on root canal surfaces.
Thiolation of Pyridine-2-sulfonamides using Magnesium Thiolates
Authors: Heinz Benjamin , Balkenhohl Moritz , Knochel Paul
Published: September 2019

The thiolation of pyridine-2-sulfonamides using magnesium thiolates is reported. The ortho-functionalizations of these sulfonamides using TMPMgCl·LiCl (TMP = 2,2,6,6-tetramethylpiperidyl) followed by electrophilic quenching produced a range of 3-functionalized pyridine-2-sulfonamides, which were subsequently converted into the corresponding thioethers. Finally, symmetric or asymmetric diorganodisulfides were employed as electrophiles in a one-pot ortho-functionalization–thiolation procedure, leading to pyridine 2,3-disubstituted dithioethers.
Quality of Life Assessment by the Endometriosis Health Profile (EHP-30) Questionnaire Prior to Treatment for Ovarian Endometriosis in Brazilian Women
Authors: Florentino André Vinícius de Assis , Pereira Ana Maria Gomes , Martins João Alfredo , Lopes Reginaldo Guedes Coelho , Arruda Raquel Martins
Published: September 2019

Objective To evaluate the existence of an association between ultrasound findings and epidemiological and clinical factors using results obtained from the EHP-30 questionnaire in women with ovarian endometriosis.

Methods A cross-sectional observational study was performed between July 2012 and May 2015, in which patients with chronic pelvic pain suggestive of endometrioma, as indicated by the results from a transvaginal pelvic ultrasonography, completed the standardized Endometriosis Health Profile - 30 (EHP-30) questionnaire to access quality-of-life scores before beginning treatment for endometriosis. A total of 65 patients were included. The data was analyzed in the statistical program IBM SPSS Statistics for Windows, Version 22.0 (IBM Corp., Armonk, NY, USA) for the comparison of data through linear multiple regression.

Results The suitability of the linear regression model was confirmed by the histogram of the dependent variable and the residue distribution plot, confirming the trend of linearity as well as the homogeneous dispersion of the residues. The mean age of the patients was 39.7 ± 7.1 years old. The majority was Caucasian (64.5%), had completed higher education (56.5%) and was nulligravida (40.3%). Infertility was present in 48.4% of the patients studied. Out of the total sample, 80.6% of the cases were symptomatic and complained mainly of acyclic pain, 79% of dysmenorrhea, and 61.3% of dyspareunia. This reflects the negative influence of endometriosis on the quality of life of patients with this disease.

Conclusion Dyspareunia and acyclic pain were independent factors of correlation with high scores in the EHP-30 questionnaire, reflecting a worse quality of life.
Two-Year Outcomes of Infants with Stage 2 or Higher Retinopathy of Prematurity: Results from a Large Multicenter Registry
Authors: Tolia Veeral N. , Ahmad Kaashif A. , Jacob Jack , Kelleher Amy S. , McLane Nick , Arnold Robert W. , Clark Reese H. ,   for the MEDNAX ROP Registry Investigators
Published: September 2019

Objective To define the incidence of ophthalmologic morbidities in the first 2 years of life among infants diagnosed with stage 2 or higher retinopathy of prematurity (ROP).

Study Design We prospectively enrolled premature infants with stage 2 or higher ROP. The infants were followed up for 2 years, and we report on data collected from outpatient ophthalmology and primary care visits.

Results We enrolled 323 infants who met inclusion criteria, of which 112 (35%) received treatment with laser surgery (90) or bevacizumab (22). Two-year follow-up was available for 292 (90%) of the cohort. The most common ophthalmologic conditions at follow-up were hyperopia (35%), astigmatism (30%), strabismus (21.9%), myopia (19.2%), anisometropia (12%), and amblyopia (12%). Severe ophthalmologic morbidities such as retinal detachment and cataracts were rare, but occurred in both treated and untreated infants. Overall, 22.6% of the infants were wearing glasses at 2 years, including 8.5% of the untreated infants.

Conclusion Patients with stage 2 or higher ROP remain at significant risk for ophthalmological morbidity through 2 years of age. Infants with regression of subthreshold ROP who do not require treatment represent an underrecognized population at long-term ophthalmological risk.

ClinicalTrials.gov Identifier NCT01559571.
Prevalence of Sexual Dysfunctions and their Associated Factors in Pregnant Women in an Outpatient Prenatal Care Clinic
Authors: Guendler Julianna Azevedo , Katz Leila , Flamini Maria Eduarda Duarte Mello , Lemos Andrea , Amorim Melania Maria
Published: September 2019

Objective To determine the prevalence of sexual dysfunction and its associated factors in pregnant women.

Methods A descriptive, cross-sectional study including 262 pregnant women aged 18 years or older with gestational age between 10 and 35 weeks. Women with urinary tract infections and conditions of gestational risk were excluded. The Pregnancy Sexual Response Inventory (PSRI) questionnaire was used. We performed a univariate descriptive analysis, and comparisons between the mean values of the sexual function domains were made using the Student t-test. The chi-squared test was used to determine the association between the independent and dependent variables. The prevalence ratios, with their respective 95% confidence intervals, were also estimated, and a multivariate analysis was performed.

Results A total of 64.9% of women reported a decrease in the frequency of sexual activity during pregnancy. Slightly more than half of the women (50.8%) were satisfied, and arousal was reported as excellent/good by 30.5% of them. The frequency of sexual difficulties/dysfunctions increased with pregnancy, rising from 5.7% to 58.8%, and pain during sexual intercourse was reported by 45.8% of them. Having higher education degree decreased the chance of being sexually dissatisfied by 50%. The total PSRI score showed a significant decrease from the prepregnancy period (mean score = 89.8, “excellent”) to the pregnancy period (mean score = 59.2, “good”).

Conclusion The mean sexual function score during pregnancy was classified as good, although most pregnant women reported at least one type of alteration in the sexual function domains, and the report of dissatisfaction was more frequent in women with lower schooling.
Ethanol as Dentin Pretreatment on the Bonding Performance of a Two-Step Etch-and-Rinse Adhesive: An In Vivo Study
Authors: Silva Francisco Cláudio Fernandes Alves , Feitosa Victor Pinheiro , Saboia Vicente de Paulo Aragão
Published: September 2019

Objective The aim of this study was to evaluate the use of 70 vol.% ethanol as a dentin pretreatment on the bond strength (BS) of a two-step etch-and-rinse adhesive.

Materials and Methods Resin composite Class I restorations were clinically bonded to acid-etched dentin of human sound third molars using Adper Single Bond 2 (SB, 3M ESPE) and randomly divided into two major groups: dentin saturated with water (control) or 70 vol.% ethanol (ethanol). The teeth were divided into two subgroups: immediately extracted and tested after 24 hours and extraction after 18 months. Bonded teeth (Adper SB 2) were cut into resin–dentin sticks that were tested by microtensile BS, and the failure mode was thereafter evaluated.

Statistical Analysis Data were statistically analyzed using two-way analysis of variance and Holm–Sidak post hoc test (α = 0.05). Additional bonded resin–dentin slabs from each group were examined under light microscopy (LM) using the Masson's trichrome staining technique.

Results The lowest BS was obtained by ethanol pretreated dentin after aging, while other groups presented similar BS. The LM analysis showed the presence of resin-sparse collagen fibrils in groups examined immediately (24 hours) and the presence of several gaps due to collagen degradation at the interfaces of ethanol pretreated aged specimens (18 months).

Conclusion The use of 70 vol.% ethanol in dentin before the application of a two-step etch-and-rinse adhesive should be avoided once it resulted in a significant drop on the BS.
Quantification of textual comprehension difficulty with an information theory-based algorithm
Authors: Ribeiro Louise Bogéa , Rodrigues Anderson Raiol , Costa Kauê Machado , da Silva Filho Manoel
Published: September 2019

Textual comprehension is often not adequately acquired despite intense didactic efforts. Textual comprehension quality is mostly evaluated using subjective criteria. Starting from the assumption that word usage statistics may be used to infer the probability of successful semantic representations, we hypothesized that textual comprehension depended on words with high occurrence probability (high degree of familiarity), which is typically inversely proportional to their information entropy. We tested this hypothesis by quantifying word occurrences in a bank of words from Portuguese language academic theses and using information theory tools to infer degrees of textual familiarity. We found that the lower and upper bounds of the database were delimited by low-entropy words with the highest probabilities of causing incomprehension (i.e., nouns and adjectives) or facilitating semantic decoding (i.e., prepositions and conjunctions). We developed an openly available software suite called CalcuLetra for implementing these algorithms and tested it on publicly available denotative text samples (e.g., articles, essays, and abstracts). We propose that the quantitative model presented here may apply to other languages and could be a tool for supporting automated textual comprehension evaluations, and potentially assisting the development of teaching materials or the diagnosis of learning disorders.
Plasma flow equilibria in 2D cylindrically symmetric expanding magnetic field
Authors: Gupta Sneha , Sharma Devendra
Published: September 2019

A steady-state plasma flow exiting through an expanding magnetic field is studied by means of 2D particle in cell numerical simulations. The effects of change in the localized plasma source region dimension and the associated plasma transit length in an upstream, uniform-magnetic-field region were examined, simulating cases with different axial lengths of the dielectric plasma source region, distinct from the location of physical expansion. Axial potential profiles at various radial locations show development of a stepwise axial potential drop, producing plasma (ion) acceleration in the corresponding regions. For a narrow source region with a long pre-expansion flow region, nonmonotonic potential variation is recovered where ion phase-space scatters show the trapped region and signatures of chaotic ion trajectories and possible pre-expansion ion heating. Considering a relevance of the studied flow equilibria to the thrust generation schemes for space propulsion, a formal estimate of thrust values associated with the plasma outflow is also done for the cases simulated.
Slow manifolds for a nonlocal fast-slow stochastic system with stable Lévy noise
Authors: Zulfiqar Hina , Yuan Shenglan , He Ziying , Duan Jinqiao
Published: September 2019

This work aims at understanding the slow dynamics of a nonlocal fast-slow stochastic evolutionary system with stable Lévy noise. Slow manifolds along with the exponential tracking property for a nonlocal fast-slow stochastic evolutionary system with stable Lévy noise are constructed, and two examples with numerical simulations are presented to illustrate the results.
Mechanical alloying of Si and Fe: Quantum-mechanical calculations applied to Mössbauer and X-ray diffraction studies
Authors: Dobysheva L. V.
Published: September 2019

Hyperfine parameters of iron nuclei such as isomer shift, quadrupole splitting, and asymmetry parameter are calculated for β-FeSi2 with and without vacancies, using density functional theory. They are applied, in combination with parameters of α-FeSi2 obtained earlier, for analyzing Mössbauer and X-ray diffraction experiments on the mechanical alloying of silicon with iron in the range of 1–33 at. % of Fe. Such an approach allows more detailed and precise information to be obtained on the structure of Fe–Si samples. In particular, the fraction of vacancies in α- and β-FeSi2 is estimated, and the mechanism of formation of these phases and their transformation into each other is discussed. A new model is developed for analyzing experiments on hyperfine interaction, such as Mössbauer spectroscopy, time-differential perturbed-angular correlation, and the like, for Fe–Si systems with a high Si content.
Laser-produced uranium plasma characterization and Stark broadening measurements
Authors: Burger M. , Skrodzki P. J. , Jovanovic I. , Phillips M. C. , Harilal S. S.
Published: September 2019

This work reports the spatiotemporal diagnostics of uranium species in plasma plumes produced by nanosecond near-infrared laser pulses in a low-pressure environment. Spatially and temporally resolved emission spectroscopy experiments are combined with the modeling of uranium emission for investigating the dynamics of the plume. The Saha-Eggert equation and Boltzmann plots generated from numerous U I transitions are used to infer temperature. This work also reports the measurements of uranium Stark broadening parameters for U I 499.01 nm and U II 500.82 nm transitions. The Stark widths of select U transitions were measured by comparing their linewidths with the broadening of the O I 777.19 nm line. The electron density was found to be of the order of 1016 cm−3, while the temperature was found to be in the range of 3000–9000 K. In addition to enhancing the fundamental understanding of high-Z plasmas in reduced-pressure environments, the knowledge of Stark broadening parameters could improve the modeling capabilities and analytical performance of techniques that rely on emission plasma spectroscopy.
Intracavity optogalvanic detection of 14C using a stabilized 14CO2 laser
Authors: Murnick D. E. , DeGuzman M. , Thompson Joshua , Bacha T. , Liu Junming
Published: September 2019

Intracavity optogalvanic detection of 14C utilizes the narrow band specificity of 14CO2 laser resonances in the infrared spectrum, coupled with greatly enhanced sensitivity from amplified effective path lengths in optical cavities. Background (nonresonant) interactions are also enhanced in such cavities, making proper separation of signals from background imperative. Intracavity Optogalvanic Spectroscopy (ICOGS) is similar to cavity ring-down spectroscopy (CRDS) with certain crucial differences. An ICOGS model, based on a basic CO2 laser and optogalvanic effect physics, is presented. Experimental results using a laboratory instrument with a continuous flow of small CO2 samples in a buffer gas illustrate the model. It is shown that acquisition of optimized signal-to-background ratios for the quantitation of 14CO2 in samples of order 10 μg is achievable, considerably smaller than with CRDS.
Measurement of refractive index of powder by prism coupler
Authors: Chen Feng , Xu Qing , Zhang Pei , Zhang Zi-Bo , Wong Wing-Han , Pun Edwin Yue-Bun , Zhang De-Long
Published: September 2019

Refractive index of optical material of powder is measured not as easily as a bulk material. Here, the prism coupling technique in combination with the immersion method is proposed to measure the refractive index of an optical material of powder. First, the powder material to be measured was dispersed in α-bromonaphthalene (C10H7Br) liquid to form a suspension mixture. The refractive index of the mixture, together with that of pure C10H7Br, was then measured at the wavelengths of 632.8, 1311, and 1553 nm using a commercial prism coupler. From the measured index values of pure C10H7Br and powder-dispersed mixture, the refractive index of the powder material was obtained on the basis of the Maxwell-Garnett model. Microcrystal powder from a LiNbO3 single-crystal, which has the known refractive index values, has been exemplified to demonstrate the method. The results show that the method is feasible with an accuracy of ±0.05.
A low-energy compact Shanghai-Wuhan electron beam ion trap for extraction of highly charged ions
Authors: Liang Shiyong , Lu Qifeng , Wang Xincheng , Yang Yang , Yao Ke , Shen Yang , Wei Baoren , Xiao Jun , Chen Shaolong , Zhou Pengpeng , Sun Wei , Zhang Yonghui , Huang Yao , Guan Hua , Tong Xin , Li Chengbin , Zou Yaming , Shi Tingyun , Gao Kelin
Published: September 2019

A low-energy, compact, and superconducting electron beam ion trap (the Shanghai-Wuhan EBIT or SW-EBIT) for extraction of highly charged ions is presented. The magnetic field in the central drift tube of the SW-EBIT is approximately 0.21 T produced by a pair of high-temperature superconducting coils. The electron-beam energy of the SW-EBIT is in the range of 30–4000 eV, and the maximum electron-beam current is up to 9 mA. Acting as a source of highly charged ions, the ion-beam optics for extraction is integrated, including an ion extractor and an einzel lens. A Wien filter is then used to measure the charge-state distribution of the extracted ions. In this work, the tungsten ions below the charge state of 15 have been produced, extracted, and analyzed. The charge-state distributions and spectra in the range of 530–580 nm of tungsten ions have been measured simultaneously with the electron-beam energy of 279 eV and 300 eV, which preliminarily indicates that the 549.9 nm line comes from W14+.
Adjoint method for the optimization of insulated gate bipolar transistors
Authors: Zhu C. , Andrei P.
Published: September 2019

A mathematical algorithm is presented for the computation of optimum doping profiles that maximize the breakdown voltage and on-state current in insulated gate bipolar transistors (IGBT). The algorithm is based on the evaluation of doping sensitivity functions, which are defined as the functional derivatives of the breakdown voltage and on-state current with respect to doping concentration. These functions are computed using an adjoint method and are used in combination with a gradient-based technique to search the optimization space of possible doping configurations efficiently. The mathematical algorithm is implemented numerically to optimize semiconductor devices that are simulated using finite element models and, then, applied to punch-through IGBTs with planar structure. In order to optimize the breakdown voltage it is shown that it is optimum to decrease the doping concentration in the drift region, particularly near the p-type junction on the emitter side and introduce p-type layers with low doping concentration in the drift region. In the case of the on-state current it is optimum to increase the n-type concentration the drift region, near the emitter junction. Depending on the initial structure and criteria imposed during the optimization, it is possible to increase the breakdown voltage by at least 5-10% and decrease the on-state voltage by at least 200 mV. The algorithm presented in this article can be easily extended to the optimization of three-dimensional doping profiles and to the optimization of other power devices, such that power p-n junctions and power metal-oxide-semiconductor field-effect-transistors.
Two-photon absorption induced nanowelding for assembling ZnO nanowires with enhanced photoelectrical properties
Authors: Xing Songling , Lin Luchan , Zou Guisheng , Duley Walter W. , Liu Lei , Norman Zhou Y.
Published: September 2019

The joining of semiconductor nanowires (NWs) is fundamental for the construction and assembly of high performance nanoelectronic devices, but the development of reliable methods of nanojoining and nanowelding of these components has been elusive to date. In this work, we report a methodology for laser welding of wide bandgap NWs based on two-photon absorption. Two photon excitation during femtosecond laser irradiation leads to the generation of excitons forming an electron-hole plasma. As an application of this technique, we show that two-photon excitation is effective in the nanowelding of two ZnO NWs. A nanoweld, resulting in the formation of an interconnected structure, occurs when the energy in the solid state plasma is deposited in the contact area between the two ZnO NWs. During excitation with ultrashort laser pulses, rapid melting and solidification result in the generation and freezing out of oxygen vacancies in the irradiated area and the region near the contact between the two components. This enhances exciton trapping and energy deposition at the contact, facilitating the formation of a bond between the two NWs. It is also found that the absorption of visible light is significantly increased in ZnO NW structures assembled via two-photon femtosecond laser processing. In addition, the junction between two ZnO NWs created in this way exhibits a photoresponse that is not present prior to nanojoining. These results indicate that two-photon excitation is a promising technique for the selective deposition of thermal energy in semiconductor NWs in the absence of plasmonic interactions.
Dispersive sensing in hybrid InAs/Al nanowires
Authors: Sabonis Deividas , O'Farrell Eoin C. T. , Razmadze Davydas , van Zanten David M. T. , Suter Judith , Krogstrup Peter , Marcus Charles M.
Published: September 2019

Dispersive charge sensing is realized in hybrid semiconductor-superconductor nanowires in gate-defined single- and double-island device geometries. Signal-to-noise ratios (SNRs) were measured in both the frequency and time domains. Frequency-domain measurements were carried out as a function of frequency and power and yield a charge sensitivity of 1 × 10–3 e/Hz for an ∼11 MHz measurement bandwidth. Time-domain measurements yield SNR > 1 for a 20 μs integration time. At zero magnetic field, photon-assisted tunneling was detected dispersively in a double-island geometry, indicating coherent hybridization of the two superconducting islands. At an axial magnetic field of 0.6 T, subgap states are detected dispersively, demonstrating the suitability of the method to sensing in the topological regime.
Sensing properties of Ni-doped boron nitride nanotube to SF6 decomposed components: A DFT study
Authors: Pi Shoumiao , Zhang Xiaoxing , Chen Dachang , Tang Ju
Published: September 2019

In this paper, the sensing property of Ni-BNNT to SO2, SOF2 and SO2F2 were investigated based on the DFT method to explore its potential as a chemical gas sensor. Our results show that Ni-doping could significant deform the electronic behavior of the BNNT, reducing its bandgap largely, from 3.712 eV to 0.601 eV. Ni-BNNT behaves strong chemisorption upon SO2 molecule with adsorption energy of -0.864 eV, while weak physisorption upon SOF2 and SO2F2 molecules with adsorption energy of -0.522 and -0.223 eV. The DOS analysis suggests the strong electron hybridization in SO2 system, while weak orbital interaction in the SOF2 and SO2F2 systems. Upon SO2, the Ni-BNNT could be a promising sensors for sensitive detection while it is unsuitable for detecting SOF2 or SO2F2 due to the weak interaction and extremely short recovery time. This work provides a first insight into the application of Ni-BNNT for detecting SF6 decomposed components, which would be beneficial for effectively evaluating the operation status of SF6 insulated devices.
REEs – a possible tool for geographical origin assessment?
Authors: Magdas Dana Alina , Marincas Olivian , Cristea Gabriela , Feher Ioana , Vedeanu Nicoleta
Published: September 2019

Environmental contextRare earth element profiles of foodstuffs reflect both the soil fingerprint and the specific agricultural practice for a certain location. This review describes the advantages and limitations of using rare earth elements as markers for geographical discrimination as a function of food matrix. The technique has great potential for establishing the geographical origin of foodstuffs.
AbstractThe present work aims to present the application of the content of rare earth elements (REEs) in the authentication of food and beverage studies, mainly regarding the geographical origin. Therefore, the potential, as well as the limitation, of these emerging markers are separately presented for different food matrices. It is observed that for most of the discussed matrices, the highest discrimination potential is provided by the LREEs (light REEs). It has also been suggested in the literature that the content of REEs is minimally affected by harvesting years, which enhances the potential to differentiate between samples from different origins. Reported studies have shown that the efficiency of the REEs profile is the most effective for the unprocessed food matrix (e.g. vegetables, fruits and meat) and has a low efficiency for commodities like wine, which suggests that the fractionation of REEs that occurs during the wine making process limits the use of these elements as geographical tracers.