bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic values of novel biomarkers in patients with AL amyloidosis
Authors: Kim Darae , Lee Ga Yeon , Choi Jin-Oh , Kim Kihyun , Kim Seok Jin , Ju Eun-Seon , Jeon Eun-Seok
Published: August 2019

As cardiac involvement is the most important prognostic marker in light-chain amyloidosis (AL), revised Mayo staging for AL incorporated N-terminal pro-brain natriuretic peptide (NTproBNP) and troponin T (TnT). However, prognostic value of novel biomarkers, such as soluble suppression of tumorigenicity 2 (sST2), growth differentiation factor 15 (GDF15), or osteopontin (OPN) is unknown in AL amyloidosis. We aimed to investigate additive predictive effects of novel biomarkers for overall mortality rates of AL amyloidosis patients. Levels of sST2, GDF15, and OPN were quantified at diagnosis in a total of 73 AL amyloidosis patients at Samsung Medical Center from 2010 to 2016. The median follow-up duration of the censored cases was 18.0 (12.4–28.1) months. A total of 25 deaths occurred during the follow-up period. Two novel biomarkers, sST2 and GDF-15 showed satisfactory predictive performances for both one-year and overall survival from ROC analysis. Best cut-off values for predicting one-year mortality were selected. Elevated sST2 and GDF-15 levels showed significant incremental prognostic values in addition to NT-ProBNP and TnT for overall mortality. Patients were assigned 1 point for elevated sST2 or GDF-15. The mean values of NT-proBNP, TnT, mean LV wall thickness, and septal e′ velocity differed significantly according to the scores. Patients with higher scores showed significantly worse prognosis even in patients with advanced revised Mayo staging. Two novel biomarkers, sST2 and GDF-15, showed satisfactory prognostic value for overall survival of AL amyloidosis patients. Furthermore, sST2 and GDF-15 showed additive incremental values over conventional biomarkers and further discriminated prognosis of patients in advanced stages.
Shootins mediate collective cell migration and organogenesis of the zebrafish posterior lateral line system
Authors: Urasaki Akihiro , Morishita Seiya , Naka Kosuke , Uozumi Minato , Abe Kouki , Huang Liguo , Watase Emiko , Nakagawa Osamu , Kawakami Koichi , Matsui Takaaki , Bessho Yasumasa , Inagaki Naoyuki
Published: August 2019

The zebrafish sensory posterior lateral line is an excellent model system to study collective cell migration and organogenesis. Shootin1 is a cytoplasmic protein involved in neuronal polarization and axon guidance. Previous studies have shown that shootin1 couples actin filament retrograde flow with extracellular adhesive substrates at the leading edge of axonal growth cones, thereby producing mechanical force for the migration and guidance of axonal growth cones. However, the functions of shootin in peripheral cells remain unknown. Here we identified two novel shootin family members, shootin2 and shootin3. In zebrafish, shootin1 and shootin3 are expressed in the posterior lateral line primordium (PLLP) and neuromasts during embryonic development. A shootin1 mutant displayed a reduced speed of PLLP migration, while shootin1;shootin3 double mutation inhibited cell proliferation in the PLLP. Furthermore, our results suggest that shootin1 and shootin3 positively regulate the number of neuromasts and the number of cells in deposited neuromasts. Our study demonstrates that shootins mediate collective cell migration of the posterior lateral line primordium and formation of neuromasts in zebrafish.
Analysis of Choroidal Vascularity in Children with Unilateral Hyperopic Amblyopia
Authors: Baek Jiwon , Lee Anna , Chu Miyoung , Kang Nam Yeo
Published: August 2019

This institutional case control study was carried out to compare choroidal vascularity (CV) in amblyopic eyes, fellow eyes, and control eyes in children with unilateral hyperopic amblyopia. Sixty-four eyes of 32 childeren with unilateral anisometropic hyperopic amblyopia and 38 eyes of 19 healthy children (controls), aged 3 to 16 years. Subfoveal choroidal thickness (CT) and CV were measured using spectral domain optical coherence tomography. The mean subfoveal CT of amblyopic eyes (338.9 ± 60.0 μm) was greater than that of fellow eyes (315.3 ± 63.3 μm, P = 0.043) and control eyes (313.0 ± 42.1 μm, P = 0.025). The mean CV of amblyopic eyes (0.715 ± 0.020) was greater than that of control eyes (0.700 ± 0.020, P < 0.001). While a positive correlation between CT and CV was found in normal eyes (r = 0.470, P = 0.004), a strong negative correlation existed in amblyopic eyes (r = −0.684, P < 0.001). In conclusion, although mean CV was higher in amblyopic eyes, the negative correlation between CT and CV may suggests insufficient blood supply to the outer retina and choroid in the affected eyes of patients with unilateral anisometropic hyperopic amblyopia.
Predictive and Prognostic Value of 18F-fluorodeoxyglucose Uptake Combined with Thymidylate Synthase Expression in Patients with Advanced Non-Small Cell Lung Cancer
Authors: Moon Seung Hwan , Sun Jong-Mu , Ahn Jin Seok , Park Keunchil , Kim Byung-Tae , Lee Kyung-Han , Ahn Myung-Ju , Choi Joon Young
Published: August 2019

We investigated the relationship between tumor 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography/computed tomography (PET/CT) scans and thymidylate synthase (TS) expression. In addition, we evaluated the value of FDG uptake in predicting treatment response and prognosis when combined with TS expression in patients with advanced non-small cell lung cancer (NSCLC). We measured the maximum standard uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of tumor lesions on pretreatment scan in 234 patients (age: 60.1 ± 9.4 years; males: 56.4%) with stage IV non-squamous NSCLC who were enrolled in the prospective phase II clinical trial. We investigated the correlation of the parameters with TS expression and the predictive values of the parameters compared with other clinical factors. Among these parameters, TLG was the most relevant parameter that had a significant correlation with TS expression (ρ = 0.192, P = 0.008). A multivariable Cox proportional-hazards model revealed that high TLG was a significant independent predictor for treatment response (hazard ratio [HR]: 2.05; P = 0.027), progression-free survival (HR: 1.39; P = 0.043), and overall survival (HR: 1.65; P = 0.035) with other factors. In patients with advanced non-squamous NSCLC, tumor TLG on pretreatment PET/CT scan has predictive and prognostic value.
Effect of comprehensive initial training on the variability of left ventricular measures using fast-SENC cardiac magnetic resonance imaging
Authors: Lapinskas Tomas , Hireche-Chikaoui Hanane , Zieschang Victoria , Erley Jennifer , Stehning Christian , Gebker Rolf , Giusca Sorin , Korosoglou Grigorios , Zaliunas Remigijus , Backhaus Sören Jan , Schuster Andreas , Pieske Burkert , Kelle Sebastian
Published: August 2019

Cardiac magnetic resonance (CMR) is becoming the imaging modality of choice in multicenter studies where highly reproducible measurements are necessary. The purpose of this study was to assess the effect of comprehensive initial training on reproducibility of quantitative left ventricular (LV) parameters estimated using strain-encoded (SENC) imaging. Thirty participants (10 patients with heart failure (HF) and preserved LV ejection fraction (HFpEF), 10 patients with HF and reduced LV ejection fraction (HFrEF) and 10 healthy volunteers) were examined using fast-SENC imaging. Four observers with different experience in non-invasive cardiac imaging completed comprehensive initial training course and were invited to perform CMR data analysis. To assess agreement between observers, LV volumes, mass, ejection fraction (LVEF), global longitudinal strain (GLS) and global circumferential strain (GCS) were estimated using dedicated software (MyoStrain, USA). To test intraobserver agreement data analysis was repeated after 4 weeks. SENC imaging and analysis were fast and were completed in less than 5 minutes. LV end-diastolic volume index (LVEDVi), LVEF and strain were significantly lower in HFpEF patients than in healthy volunteers (p = 0.019 for LVEDVi; p = 0.023 for LVEF; p = 0.004 for GLS and p < 0.001 for GCS). All LV functional parameters were further reduced in HFrEF. Excellent interobserver agreement was found for all LV parameters independently of the level of experience. The reproducibility of LV mass was lower, especially at the intraobserver level (ICC 0.91; 95% CI 0.74–0.96). LV volumetric and functional parameters derived using fast-SENC imaging, are highly reproducible. The appropriate initial training is relevant and allows to achieve highest concordance in fast-SENC measurements.
Isosteviol Sodium Protects against Ischemic Stroke by Modulating Microglia/Macrophage Polarization via Disruption of GAS5/miR-146a-5p sponge
Authors: Zhang Hao , Lu Minyi , Zhang Xiaofeng , Kuai Yihe , Mei Ying , Tan Qiwen , Zhong Kailun , Sun Xiaoou , Tan Wen
Published: August 2019

Recent studies have shown that transforming microglia phenotype from pro-inflammation of M1 phenotype to anti-inflammation and tissue-repairing M2 phenotype may be an effective therapeutic strategy for preventing ischemic stroke brain injury. Isosteviol Sodium (STV-Na) has shown promise as a neuroprotective agent in cerebral ischemia model, although its effect on microglial polarization and chronic recovery after stroke is not clear. Here, we demonstrated that STV-Na treatment significantly reduced cerebral ischemic damage at both acute and chronic time points. STV-Na has a profound regulatory effect on microglia response after stroke. It can promote M2 polarization and inhibit microglia-mediated inflammation (M1) response following stroke in vivo and in vitro. Furthermore, we also found that Growth Arrest-Specific 5 (GAS5) altered OGD/R-induced microglial activation by increasing Notch1 expression via miR-146a-5p, the mRNA level of GAS5 and the protein level of Notch1 in vivo and in vitro, were discovered that both downgraded with STV-Na. Taken together, the present study demonstrated that STV-Na exerted neuroprotective effects by modulating microglia/macrophage polarization in ischemic stroke via the GAS5/miR-146a-5p sponge. These findings provide new evidence that targeting STV-Na could be a treatment for the prevention of stroke-related brain damage.
Translating clinical trial results into personalized recommendations by considering multiple outcomes and subjective views
Authors: Dagan Noa , Cohen-Stavi Chandra J. , Avgil Tsadok Meytal , Leibowitz Morton , Hoshen Moshe , Karpati Tomas , Akriv Amichay , Gofer Ilan , Gilutz Harel , Podjarny Eduardo , Bachmat Eitan , Balicer Ran D.
Published: August 2019

Currently, clinicians rely mostly on population-level treatment effects from RCTs, usually considering the treatment's benefits. This study proposes a process, focused on practical usability, for translating RCT data into personalized treatment recommendations that weighs benefits against harms and integrates subjective perceptions of relative severity. Intensive blood pressure treatment (IBPT) was selected as the test case to demonstrate the suggested process, which was divided into three phases: (1) Prediction models were developed using the Systolic Blood-Pressure Intervention Trial (SPRINT) data for benefits and adverse events of IBPT. The models were externally validated using retrospective Clalit Health Services (CHS) data; (2) Predicted risk reductions and increases from these models were used to create a yes/no IBPT recommendation by calculating a severity-weighted benefit-to-harm ratio; (3) Analysis outputs were summarized in a decision support tool. Based on the individual benefit-to-harm ratios, 62 and 84% of the SPRINT and CHS populations, respectively, would theoretically be recommended IBPT. The original SPRINT trial results of significant decrease in cardiovascular outcomes following IBPT persisted only in the group that received a “yes-treatment” recommendation by the suggested process, while the rate of serious adverse events was slightly higher in the "no-treatment" recommendation group. This process can be used to translate RCT data into individualized recommendations by identifying patients for whom the treatment’s benefits outweigh the harms, while considering subjective views of perceived severity of the different outcomes. The proposed approach emphasizes clinical practicality by mimicking physicians’ clinical decision-making process and integrating all recommendation outputs into a usable decision support tool.
Antibodies Versus Aptamers: A Comparative View
Authors: Alsager Omar A. , Eissa Shimaa , Zourob Mohammed
Published: August 2019

Antibodies are large proteins generated in vivo to bind specifically to a wide spectrum of targets ranging from biological to environmental molecules. They play a vital role in research, diagnostics, sensing, and therapeutic applications. Over the past few decades, advancements have been made to improve the performance of antibodies, specifically in the area of immunosensors. However, there has been an urgent need for alternative high-quality recognition probes that can be produced synthetically in bulk quantity to ensure better reproducibility and lower cost, as well as avoiding the need of using animals in the production process. Aptamers are synthetic nucleic acid single-stranded (ss) DNAs or RNAs that can bind with high affinity and specificity to their targets. They can be generated via in vitro section protocol, known as systematic evolution of ligands by exponential enrichment (SELEX). The advantages of aptamers promoted their successful incorporation in several signal transduction schemes, some of which reached the commercial market for point-of-care and in-field applications. This chapter describes the two types of affinity reagents: antibodies and aptamers, and their methods of production, advantages, and limitations. The focus will be directed at their incorporation in analytical transduction methods and how aptamer molecular size as well as unique conformational change upon target binding has triggered the evolution of new sensing methods.
Sequential sandwich immunoassay for simultaneous detection in trace samples using single-channel surface plasmon resonance
Authors: Xia Yinqiang , Zhang Peiqian , Yuan Hui , Su Rongxin , Huang Renliang , Qi Wei , He Zhimin
Published: August 2019

An efficient and facile method of a sequential sandwich immunoassay was developed for simultaneous detection in trace samples using single-channel SPR with low-dosage samples and testing times.
Photo-induced electron transfer in a metal–organic framework: a new approach towards a highly sensitive luminescent probe for Fe3+
Authors: Cui Yuanjing , Yue Dan , Huang Yike , Zhang Jun , Wang Zhiyu , Yang Deren , Qian Guodong
Published: August 2019

By utilizing the d-PET process between ligands 4,4′-bimbp and H2pta in a Co-based mixed-ligand MOF, ZJU-109, a fluorescent turn-on sensor for Fe3+ with a detection limit as low as 0.053 μM has been demonstrated.
Facile one-pot generation of metal oxide/hydroxide@metal–organic framework composites: highly efficient bifunctional electrocatalysts for overall water splitting
Authors: Zheng Shasha , Guo Xiaotian , Xue Huaiguo , Pan Kunming , Liu Chunsen , Pang Huan
Published: August 2019

The metal oxide/hydroxide@MOF composites have been regarded as a very promising electrocatalyst due to their facile one-step hydrothermal synthesis strategy, high electrocatalytic activity, and excellent cycling stability.
Charge density distribution in the crystals of N-n-butyltetrachlorophthalimide. Atoms-in-molecules analysis of different types of halogen interactions
Authors: Owczarzak Agata , Dutkiewicz Grzegorz , Kubicki Maciej
Published: August 2019

The charge density distribution in N-n-butyltetrachlorophthalimide was experimentally determined using high-resolution X-ray diffraction data and the Hansen–Coppens multipole formalism.
Epoxide ring-opening reaction promoted by ionic liquid reactivity: interplay of experimental and theoretical studies
Authors: Chen Shengxin , Zeng Guixiang , Li Yingwei , He Bin , Liu Ruixia , Zhang Suojiag
Published: August 2019

Ionic liquids (ILs) have been widely introduced recently into the epoxide ring-opening reaction as catalysts or solvent without considering the chemical stability of ILs in propylene oxide (PO).
Children's exposure to perfluoroalkyl acids – a modelling approach
Authors: Balk Fabian G. P. , Winkens Pütz Kerstin , Ribbenstedt Anton , Gomis Melissa I. , Filipovic Marko , Cousins Ian T.
Published: August 2019

The present work assesses the exposure of a child cohort to PFOA, PFOS and PFHxS from 1 year to 10.5 years of age.
One-step sonochemical synthesis of a reduced graphene oxide – ZnO nanocomposite with antibacterial and antibiofouling properties
Authors: Zhang Wei , Yang Yang , Ziemann Eric , Be'er Avraham , Bashouti Muhammad Y. , Elimelech Menachem , Bernstein Roy
Published: August 2019

Antibacterial reduced graphene oxide – ZnO nanocomposite was synthesized by a one-step sonication method. The antibiofouling surface property of a nanocomposite incorporated polymeric membrane was high with minimum Zn2+ leaching.
Different crystallographic sodium manganese oxides for capacitive deionization: performance comparison and the associated mechanism
Authors: Zhao Yubo , Liang Bolong , Zong Mingzhu , Duan Meng , Li Kexun , Lv Cuicui
Published: August 2019

The influence of the crystal structure of NMO on its desalination performance was investigated in the capacitive deionization system.
Cyanidin ameliorates the progression of osteoarthritis via the Sirt6/NF-κB axis in vitro and in vivo
Authors: Jiang Chao , Sun Ze-Ming , Hu Jia-Ning , Jin Yu , Guo Qiang , Xu Jia-Jing , Chen Ze-Xin , Jiang Ren-Hao , Wu Yao-Sen
Published: August 2019

Osteoarthritis (OA) is the most prevalent form of human arthritis which is characterized by the degradation of cartilage and inflammation.
Zn(ii)-Curcumin supplementation alleviates gut dysbiosis and zinc dyshomeostasis during doxorubicin-induced cardiotoxicity in rats
Authors: Wu Rihui , Mei Xueting , Wang Jiasheng , Sun Wenjia , Xue Ting , Lin Caixia , Xu Donghui
Published: August 2019

Dietary Zn(ii)-curcumin protects against doxorubicin-induced cardiomyopathy by modulation of the gut microbiota and maintenance of zinc homeostasis.
A flower-structured MoS2-decorated f-MWCNTs/ZnO hybrid nanocomposite-modified sensor for the selective electrochemical detection of vitamin C
Authors: Murugan N. , Kumar T. H. Vignesh , Devi N. Ramila , Sundramoorthy Ashok K.
Published: August 2019

We synthesized an MoS2/f-MWCNTs/ZnO composite and successfully used it to prepare an electrochemical sensor for the selective detection of AA in blood serum samples.
A disulfur ligand stabilization approach to construct a silver(i)-cluster-based porous framework as a sensitive SERS substrate
Authors: Wu Tong , Yin Di , Hu Xun , Yang Bo , Liu Hong , Xie Yun-Peng , Liu Shi-Xi , Ma Lulu , Gao Guang-Gang
Published: August 2019

An atomic-precise silver(i)-cluster-based MOF (UJN-1) stabilized by disulfur ligand has been demonstrated. Its reduced derivative exhibits highly sensitive SERS activity that can be ascribed to abundant hot spots sites and porosity structure.
A glutathione responsive pyrrolopyrrolidone nanotheranostic agent for turn-on fluorescence imaging guided photothermal/photodynamic cancer therapy
Authors: Zou Jianhua , Xue Lei , Yang Nan , Ren Yanfang , Fan Zhe , Wang Wenjun , Si Weili , Zhang Yewei , Huang Wei , Dong Xiaochen
Published: August 2019

Herein, GSH responsive pyrrolopyrrolidone derivatives with enhanced photodynamic/photothermal therapeutic efficacy were designed, which can be used as colorimetric probes.
Officinalins A and B, a pair of C23 terpenoid epimers with a tetracyclic 6/7/5/5 system from Salvia officinalis
Authors: Li Ling-Nan , Liu Xiao-Qin , Zhu Dong-Rong , Chen Chen , Lin Yao-Lan , Wang Wen-Li , Zhu Li , Luo Jian-Guang , Kong Ling-Yi
Published: August 2019

Officinalins A (1) and B (2), a pair of 6/7/5/5 tetracyclic C23 terpenoid epimers with a unique tetracycline-[9.6.0.03,8.012,16]-heptadecane core and a peroxide bridge, were isolated from the leaves of Salvia officinalis.
Anti-inflammatory effects of hederagenin on diabetic cardiomyopathy via inhibiting NF-κB and Smads signaling pathways in a type-2 diabetic mice model
Authors: Li Ying , Dong Junli , Shang Yinghui , Zhao Qiangqiang , Li Pengcheng , Wu Bin
Published: August 2019

Hederagenin (HED) is a bioactive natural compound of pentacyclic triterpenes extracted from many medicinal plants.
Recent advances in hexavalent chromium removal from aqueous solutions by adsorptive methods
Authors: Pakade Vusumzi E. , Tavengwa Nikita T. , Madikizela Lawrence M.
Published: August 2019

Despite the extensive existence of adsorbents for Cr(vi) removal from aqueous solutions, new adsorbents and modification of existing adsorbing materials are continuously sought after.
Formation of G-quadruplex structure in supercoiled DNA under molecularly crowded conditions
Authors: Li Dawei , Peng Peiwen , Yang Zhaoqi , Lv Bei
Published: August 2019

It is demonstrated that G-quadruplex generated from G-rich duplex in a circular DNA as a result of quadruplex stabilization and duplex destabilization created by the combined actions of negative DNA supercoiling and molecular crowding condition.
Surface enhanced dynamic nuclear polarization solid-state NMR spectroscopy sheds light on Brønsted–Lewis acid synergy during the zeolite catalyzed methanol-to-hydrocarbon process
Authors: Dutta Chowdhury Abhishek , Yarulina Irina , Abou-Hamad Edy , Gurinov Andrei , Gascon Jorge
Published: August 2019

Surface-enhanced dynamic nuclear polarization solid-state NMR spectroscopy has been applied to identify the role of surface-carbene species and elucidating Brønsted–Lewis acid synergy during the zeolite-catalyzed methanol-to-hydrocarbon process.
An effective surface modification strategy with high reproducibility for simultaneously improving efficiency and stability of inverted MA-free perovskite solar cells
Authors: Zhu Hongmei , Wu Shaohang , Yao Jiaxu , Chen Rui , Pan Ming , Chen Weitao , Zhou Jing , Zhang Wenjun , Wang Tao , Chen Wei
Published: August 2019

Highly efficient and stable inverted MA-free PSCs have been achieved by utilizing an effective surface modification strategy, which is featured as multi-functions of trap-passivation and moisture-resistance with high technical reproducibility.
Thiocarboxylate-modified Ni(OH)2 nanosheets for high-performance alkaline batteries
Authors: Zhao Hongyang , Yin Dandan , Wang Jianwei , Zheng Yuansuo , Du Yaping
Published: August 2019

Thiocarboxylate-modified Ni(OH)2 nanosheets present a superior electrochemical performance as an alkaline rechargeable battery cathode due to their highly conductive metal–sulfur bonds.
Synthesis and biomedical applications of graphitic carbon nitride quantum dots
Authors: Liu Hongji , Wang Xingyu , Wang Hui , Nie Rongrong
Published: August 2019

This review summarizes the synthetic methods and addresses current applications and future perspectives of graphitic carbon nitride quantum dots in the biomedical field.
Family of universal bidirectional DC–DC converters with an extended voltage gain
Authors: Axelrod Boris , Berkovich Yefim , Beck Yuval
Published: August 2019

This study presents a family of non‐isolated bidirectional DC–DC converters with extended DC gain. Increasing of the DC gain range is achieved due to splitting the base inductor and also by using magnetically coupled inductors. All the variants of the proposed schemes are based on the use of the dual‐half‐bridge DC–DC converter. As a result, a number of improved schemes of buck, boost and buck–boost bidirectional converters were obtained with the possibility of increasing the voltage‐boosting ratio in boost converter mode and simultaneously reducing the voltage gain in the buck converter mode. The converters have a symmetrical structure, and this ensures the operation of each of them in four modes, which gives greater flexibility in matching the voltages of the power supply with storage devices. The formulas for the DC gain, maximum voltage stresses on the switches and a comparative evaluation of these parameters are presented. The modes of operation and equivalent schemes are considered in detail. For each of the schemes, the corresponding tables for the operation of the transistors are given. The analyses of the dynamic modes of the proposed converters is shown. The experimental verification completely confirms the theoretical results.
Dynamic range analysis of one‐bit compressive sampling with time‐varying thresholds
Authors: Zhu Xiaofeng , Huang Liang , Wang Ziqian
Published: August 2019

From the point of view of statistical signal processing, the dynamic range for one‐bit quantisers with time‐varying thresholds is studied. Maximum tolerable amplitudes, minimum detectable amplitudes and dynamic ranges of this one‐bit sampling approach and uniform quantisers, such as N ‐bits analogue‐to‐digital converters (ADCs), are derived and simulated. The results reveal that like conventional ADCs, the dynamic ranges of one‐bit sampling approach are linearly proportional to the Gaussian noise standard deviations, while one‐bit sampling's dynamic ranges are lower than N ‐bits ADC under the same noise levels.
Method for compensating bandwidth error of synthetic wideband radar signal
Authors: Han Xiaoxin , zhou Chao , Liu Quanhua , Song Yuanyuan
Published: August 2019

The synthetic wideband signal has the advantages of high range and velocity resolution. It has a wide range of applications in target detection and recognition. While in the processing of signal generation, due to the improper setting of hardware system parameters, the bandwidth of the transmitting signal may not be consistent with the nominal value, which will affect the result of signal processing. In this study, the influence of system bandwidth error on synthetic high‐resolution range profile is theoretically analysed. On this basis, an error compensation method based on parameter traversal is proposed and verified with simulation and experimental data processing.
Point spread character based low SNR single pixel infrared target detection
Authors: Nan Jinghong , Zhao Baojun , Tang Linbo , Zhang Zengshuo , Tang Wei
Published: August 2019

Robust and efficient low signal‐to‐noise ratio (SNR) single pixel infrared (IR) target detection has been a key technique in IR searching and tracking system. However, there exist two critical difficulties, i.e. noise disturbance and low contrast between target and background, influencing detection accuracy. A novel IR target detection method is proposed to overcome those difficulties, by utilising the point‐spread character. Specifically, a point‐spread indicator is advocated to protect the potential target with the median filter to suppress the noise. Afterwards, a two‐step enhancement model is built to increase the contrast value between target region and surrounding background effectively. In the first step, a point‐spread local contrast method is proposed to enhance targets and suppress background. In the second step, a high boost filter is introduced to further enhance the target. In addition, an adaptive segmentation method is exploited to extract targets from the enhanced image. Experimental results on testing sequences demonstrate that this method outperforms the other state‐of‐the‐art methods in single pixel IR target detection with higher detection rate, lower false alarm rate and less time consuming.
Analysis and correction of spatial variant background ionosphere impacts on single‐pass InSAR system
Authors: Yu Lei , Zhang Yongsheng , Yu Anxi , Dong Zhen , Li Jinhui , Ji Yifei
Published: August 2019

Compared with the repeat‐pass interferometry synthetic aperture radar (InSAR) system, the single‐pass InSAR system, such as TanDEM‐X and TanDEM‐L, has better performance and less decorrelation. However, InSAR measurements can be seriously influenced by the background ionosphere, especially for InSAR system operating at lower frequencies, such as L‐band and P‐band. Low‐frequency signals propagating in the ionosphere suffer serious group delay, dispersion, scintillation and Faraday rotation, which further induce the image shift and decorrelation of SAR interferometry pairs. Since the ionosphere shows significant space‐varying and time‐varying features, the conventional ionosphere spatial invariant model is invalid for space‐borne single‐pass InSAR system. It is supposed that the time variance of ionosphere in short integration time can be neglected for low‐earth orbit InSAR system. The effect of the spatial variant ionosphere on single‐pass InSAR measurement is analysed and a correction method for InSAR products based on the prior knowledge is presented in this paper. Simulations are performed by using total electron content data obtained from the international reference ionosphere model, and the results indicate the significant error induced by spatial variant ionosphere.
Novel acceleration compensation method for highly squint mode SAR with curve trajectory
Authors: Zhou Zhichao , Ding Zegang , Zeng Tao , Li Gen , Li Linghao
Published: August 2019

Due to the influence of air currents and the control of the platform's own power system, acceleration is often present in the motion platform equipped with synthetic aperture radar (SAR) system, which causes the actual trajectory of the platform to be curved. When the acceleration is large or the azimuth accumulation time is long, a large envelope error or phase error will be caused. This problem will be more obvious in highly squint mode SAR. On the other hand, the acceleration may also cause the situation where the absolute value of the Doppler frequency rate is extremely small, resulting in the azimuthal time‐bandwidth product that is too small to satisfy the requirements of the stationary phase principle. To solve the above problems, a novel acceleration compensation method based on inertial navigation information is proposed in this article. By integrating the acceleration and velocity information provided by the inertial navigation system, the position information of maneuvering platform is obtained. Then the actual trajectory of the platform is constructed. On this basis, the envelope and phase errors caused by the acceleration are estimated. The results of real data processing verify the correctness of the analysis and the effectiveness of the proposed method.
A comparison between solar plage and network properties
Authors: Buehler D. , Lagg A. , van Noort M. , Solanki S. K.
Published: August 2019

Aims. We compare the properties of kG magnetic structures in the solar network and in active region plage at high spatial resolution.

Methods. Our analysis used six SP scans of the solar disc centre aboard Hinode SOT and inverted the obtained spectra of the photospheric 6302 Å line pair using the 2D SPINOR code.

Results. Photospheric magnetic field concentrations in network and plage areas are on average 1.5 kG strong with inclinations of 10° −20°, and have < 400 m s−1 internal and 2−3 km s−1 external downflows. At the disc centre, the continuum intensity of magnetic field concentrations in the network are on average 10% brighter than the mean quiet Sun, whilst their plage counterparts are 3% darker. A more detailed analysis revealed that all sizes of individual kG patches in the network have 150 G higher field strengths on average, 5% higher continuum contrasts, and 800 m s−1 faster surrounding downflows than similarly sized patches in the plage. The speed of the surrounding downflows also correlates with the patch area, and patches containing pores can produce supersonic flows exceeding 11 km s−1 in individual pixels. Furthermore, the magnetic canopies of kG patches are on average 9° more horizontal in the plage compared to the network.

Conclusions. Most of the differences between the network and plage are due to their different patch size distributions, but the intrinsic differences between similarly sized patches likely results from the modification of the convection photospheric convection with increasing amounts of magnetic flux.
Researches on mechanical vibrations used in assistive devices manufacturing
Authors: Bogățeanu Răzvan , Bîșu Claudiu , Dogariu Constantin , Croitoru Sorin Mihai , Tilină Dana
Published: August 2019

Deformable structures vibrate (oscillatory motion) under the action of impulses or variable forces. Vibration of a mechanical structure results from the transformation of potential energy into kinetic energy and could be used in the construction of assistive devices. The vibratory devices for posttraumatic rehabilitation of upper limbs can stimulate muscular, circulatory and neurological systems. The paper presents the necessary elements for the personalization of rehabilitation devices like orthoses and some theoretical and experimental results related to this subject. For the persons with disabilities, the integration of enabling technologies and attributes embracing mobility, sensors and actuators provides the possibility of achieving independence in their social life. The paper underlines the importance of the systematic application of technologies, engineering methodologies or other scientific principles used in order to overpass the barriers confronted by people with disabilities.
Optimizing the magnetic circuit of an actuator
Authors: Popescu Lizeta , Diodiu Lucian
Published: August 2019

The paper presents a modern method of constructive optimization of a plunger actuator with axial symmetry based on the electromagnetic simulation of several variants of magnetic circuit and excitation currents. On the basis of the force calculation developed by this actuator and the magnetic induction values in the core, we calculated the kinematic actuator parameters. Experimental determinations confirmed the precision and utility of the optimization method by electromagnetic simulation of the actuator.
From part to point cloud, the modelling of a 3D part
Authors: Muntean Diana , Bologa Octavian
Published: August 2019

The present paper focuses on the development of the composite materials in the automotiv industry by making a comparative analysis between a 3D model of the part and a real part made by a composite material, measuring the part using the point cloud. The aim is to obtain a high modeling and a more clear visualization of the composite material part.
Comparison of Quantitative Changes after passing the Laser Beam through Polymeric Material
Authors: Sýkorová Libuše , Knedlová Jana , Měřínská Dagmar , Pata Vladimír
Published: August 2019

The article focuses on laser machining of various polymeric materials. Specifically, it examines the possibility of undesirable changes in these materials as, due to the concentrated energy of the laser beam, the heat of the material is also transferred to the material near the cutting point and hence to the heat of the cut. Although the polymeric materials do not have a high thermal conductivity, it can be expected that due to the elevated temperature, different structural or chemical changes may occur near the cutting edge. Some high-molecular substances begin to split into low-molecular-weight products, and depolymerisation or degradation of the may occur. All these changes may have a negative impact on the product performance. The “Infrared Vibrational Spectroscopy” and X-ray Diffraction Analysis” were selected for experimental machining and subsequent assessment of possible change in selected polymer materials.
Experimental Researches Regarding Mechanical Behaviour of Dental Prototypes realized by Additive Technologies
Authors: Moraru Edgar , Dontu Octavian , Besnea Daniel , Rizescu Ciprian , Rizescu Dana , Popescu-Cuta Alina
Published: August 2019

The paper presents the behaviour of dental models subjected to mechanical loads. Maxillary dental arcade was obtained by additive technologies – fused deposition modelling and digital light processing. Also, it were used different materials - ABS, CarbonFil, biocompatible ABS, photopolymeric resin and the dental prototypes were tested in two areas - molar and central incisor zones with a transducer force HV 500. The experimental results highlighted the behaviour of the dental models realized by additive technologies in order to determine the maximum compressive force and maximum deformation of the maxillary in function of the material and the technology used.
Advanced Techniques used in Numerical Simulation for Deep-drawing Process
Authors: Oleksik Valentin , Breaz Radu , Racz Gabriel , Dan Brindasu Paul , Bologa Octavian
Published: August 2019

The present paper analyse the main characteristics of the numerical simulation by finite element method of the deep-drawing processes. Also the authors’ highlights the mathematical apparatus and the calculus method used for numerical simulations of metal forming processes in many of the current simulation software. The authors present the capabilities of the inverse analysis, direct analysis, implicit analysis (for springback simulation) and the optimisation analysis applied to explicit formulations.
Mechanical properties of 3D printed composites with ABS/ASA substrate and glass fiber inserts
Authors: Amza Cătălin G. , Zapciu Aurelian , Eyþórsdóttir Arnheiður , Björnsdóttir Auðbjörg , Borg Jonathan
Published: August 2019

3D printed specimens (ASTM D638 Type I) were manufactured from ABS and ASA material via additive manufacturing through material extrusion 3D printing (ME3DP). During manufacturing, the printing process has been paused, pre-impregnated biaxial or uniaxial glass fiber mesh has been placed onto the ABS/ASA substrate and then the printing process has been resumed. The obtained composite specimens have been subjected to tensile strength testing and results have been compared to those of specimens printed from homogenous material. The influence of raster angle, glass fiber direction and mesh density on resulting toughness has also been analyzed. It was found that inserting uniaxial glass fiber increases toughness of specimens in the axial direction, with a drop in layer adhesion if biaxial fiber is used. Test specimens manufactured with 30 uniaxial fiber strands embedded in a 0o raster angle 3D printed thermoplastic matrix match mechanical characteristics of injection-molded parts. The maximum mesh density without leading to delamination is one layer of glass fiber every two layers of thermoplastic matrix.
Haptics democratization: challenges and opportunities
Authors: Iacob Robert , Popescu Diana
Published: August 2019

The sense of touch is an important means of communicating and exchanging information primarily between people and between people and the environment, from the very first years of life. Nowadays, researches and technology advances in different domains make use of touch, man-computer communication and interaction throughout immersive simulation environments being also facilitated and enhanced by the kinesthetic technology.

The importance of haptic feedback for different applications is already a proved fact. However, it is still underrepresented in the everyday computer interfaces, mainly due to a current unfavourable compromise between price and user’s experience quality. That is, even if many haptic devices are available, they are either prohibitive in term of price, if provide high quality, or they are inexpensive and offer low realism haptic effects. Currently, there is no real intermediate device, and no device that can provide hardware upgrade according to users’ needs.

In this context, this paper provides an analysis of existing haptic equipment, both prototypes and commercially available devices, and presents different approaches used in haptic-based scenarios. On this basis, a critical set of requirements for a new type of haptic device are inferred. It could represent an innovative and affordable solution for a larger range of potential users: engineers, physicists, trainers, designers, researchers, as well as hobbyists.
Force and thickness prediction with FEA of the cranial implants manufactured through SPIF
Authors: Popp Mihai , Rusu Gabriela , Racz Sever-Gabriel , Popp Ilie Octavian
Published: August 2019

Single point incremental forming is a process which is primarily used for prototyping, small series production and unique parts. This procedure shows a high potential in the development of complex shape parts where the time of the execution does not play an important role. Among the applications of this process are the execution of various medical prostheses, such as: knee prostheses and cranial implants. The aim of this paper is to determine the forces which take place during the manufacture process of an cranial implant, as well as the thinning of the material through the help of finite element analysis. After the numerical simulation, from the results obtained it is possible to observe the behaviour of the material at different forces which appear during the deformation process. In addition, in this paper will be presented considerations about the thinning of the material used for the cranial implant.
The improvement of quality management system in a porcelain factory
Authors: Sârb Adina , Glevitzky Ioana , Itul Liliana , Popa Maria
Published: August 2019

According to SR EN ISO 9000:2015, quality management system can be considered “a set of Policies, Procedures, Processes and resources used to achieve the organization objectives and desired results, by manages the interacting processes, resources required and inter-related parts of the business”. The requirements of a quality management system that need to be implemented by companies in order to produce high quality products and to achieve continual improvement are described in ISO 9001. The aim of this research is to improve the quality management system implemented in a porcelain factory, named S.C. APULUM S.A. The implementation of ISO 9001:2015 in the organization involves monitoring process performance through different performance indicators. The first performance indicator highlights the situation regarding the quality of the products manufactured in a certain period and the second one emphasizes the most common defects of one of the products fabricated in the organization. Hence, identified nonconformities are analyzed using 8D method in order to identify the root-cause and to remove it. The results show that different solutions were identified and implemented in order to enhance the quality management system in the company considered.
Analytical model for assessing the investments in connectivity for small airports
Authors: Cioacă Cătălin , Boșcoianu Mircea , Bălos Dănuț , Luculescu Doru
Published: August 2019

The purpose of the research is to develop a model for the analysis of investments in connectivity. The developed model allows a more accurate capture of the impact of sources of fluctuations in investment projects aimed at increasing connectivity, using Wiener Processes and Poisson distribution. The results are solutions for improved decision-making in aviation infrastructure to the benefit of the regional economy.
Intercultural Communication and its Challenges Within the International Virtual Project Team
Authors: Dumitraşcu-Băldău Iulia , Dumitraşcu Dănuţ Dumitru
Published: August 2019

With the advance of technology, face-to-face intercultural communication moves into the online virtual environment via electronic tools such as audio-video conferencing, email, messenger chat, platforms, groups, thus distances between individuals from different cultures are reduced and the exchange of information takes place within a few seconds. Cultural differences should not be a barrier to communication but an opportunity for development. International virtual project teams (IVPTs) can benefit from cultural diversity and effective intercultural communication, because it can enhance creativity and innovation within the project team, while at the same time team members are enriched by acquiring intercultural information and developing intercultural skills. So, it becomes mandatory to understand how intercultural communication takes place in a virtual environment, which are the most important challenges and how they can be overcome. This paper aims to highlight the importance of an effective intercultural communication, the role of intercultural communication skills and which are the characteristics of intercultural communicators. In order to analyze some cultural diversity aspects within IVPTs (number of project languages used, efficiency of different online collaboration tools, misunderstandings generated by cultural diversity), an empirical research was conducted, through an online survey within 107 IVPT members. Data was analyzed using descriptive statistics through IBM SPSS Statistics software.
Review and synthesis of a walking machine (Robot) leg mechanism
Authors: Terefe Tesfaye Olana , Lemu Hirpa G. , K/Mariam Addisu
Published: August 2019

A walking machine (robot) is a type of locomotion that operates by means of legs and/or wheels on rough terrain or flat surface. The performance of legged machines is greater than wheeled or tracked walking machines on an unstructured terrain. These types of machines are used for data collections in a variety of areas such as large agricultural sector, dangerous and rescue areas for a human. The leg mechanism of a walking machine has a different joint in which a number of motors are used to actuate all degrees of freedom of the legs. In the synthesis of walking machine reported in this article, the leg mechanism is developed using integration of linkages to reduce the complexity of the design and it enables the robot to walk on a rough terrain. The dimensional synthesis is carried out analytically to develop a parametric equation and the geometry of the developed leg mechanism is modelled. The mechanism used is found effective for rough terrain areas because it is capable to walk on terrain of different amplitudes due to surface roughness and aerodynamics.
Manipulator for scanning of the pipes external surface
Authors: Niţu Constantin , Grămescu Bogdan , Cartal Adrian , Hashim Ahmed Sachit
Published: August 2019

The paper presents a very simple manipulator, which can describe a circular trajectory, in order to position a scanning device for inspecting the external surface of a pipe. The open kinematic chain has only three active joints, and for equally spaced scanning positions around the pipe, its inverse kinematics is derived by help of elementary geometry. The manipulator was built as a part of a mobile robot, serving for inspection and monitoring of the pipelines in the oil and gas industry. Being a demonstrator, its joints actuators are micro RC servos, so a calibration operation of each one was also performed.
Research on solar radiation potential as a source of renewable energy in the Motru area
Authors: Nan Marin-Silviu , Sultan Alin , Grecea Danut , Vitan Cosmin
Published: August 2019

The continuous development of the human society is in a close correlation with the increased consumption of electricity. In the past few years, the thirst for electricity at a global level, has led both to higher levels of pollution and the depletion of fossil fuels. For this reason, the issue of energy efficiency is a priority of energy strategy at national and EU level. In this context, a solution to the above problems is to increase the rate of production of electricity from renewable energy sources. Thus, the paper presents a study of solar radiation as a source of renewable energy, modelling and simulation of photovoltaic systems and validation of data numerical simulations data with the measured data in the Motru area.