bluuebunny/crossref_metadata_2025 huggingface dataset:
Malic Enzyme 1 (ME1) is pro-oncogenic in ApcMin/+ mice
Authors: Fernandes Lorenzo M. , Al-Dwairi Ahmed , Simmen Rosalia C. M. , Marji Meera , Brown Dustin M. , Jewell Sarah W. , Simmen Frank A.
Published: September 2018

Cytosolic Malic Enzyme (ME1) provides reduced NADP for anabolism and maintenance of redox status. To examine the role of ME1 in tumor genesis of the gastrointestinal tract, we crossed mice having augmented intestinal epithelial expression of ME1 (ME1-Tg mice) with ApcMin/+ mice to obtain male ApcMin/+/ME1-Tg mice. ME1 protein levels were significantly greater within gut epithelium and adenomas of male ApcMin/+/ME1-Tg than ApcMin/+ mice. Male ApcMin/+/ME1-Tg mice had larger and greater numbers of adenomas in the small intestine (jejunum and ileum) than male ApcMin/+ mice. Male ApcMin/+/ME1-Tg mice exhibited greater small intestine crypt depth and villus length in non-adenoma regions, correspondent with increased KLF9 protein abundance in crypts and lamina propria. Small intestines of male ApcMin/+/ME1-Tg mice also had enhanced levels of Sp5 mRNA, suggesting Wnt/β-catenin pathway activation. A small molecule inhibitor of ME1 suppressed growth of human CRC cells in vitro, but had little effect on normal rat intestinal epithelial cells. Targeting of ME1 may add to the armentarium of therapies for cancers of the gastrointestinal tract.
Skin α-synuclein deposits differ in clinical variants of synucleinopathy: an in vivo study
Authors: Donadio V. , Incensi A. , El-Agnaf O. , Rizzo G. , Vaikath N. , Del Sorbo F. , Scaglione C. , Capellari S. , Elia A. , Stanzani Maserati M. , Pantieri R. , Liguori R.
Published: September 2018

We aimed to characterize in vivo α-synuclein (α-syn) aggregates in skin nerves to ascertain: 1) the optimal marker to identify them; 2) possible differences between synucleinopathies that may justify the clinical variability. We studied multiple skin nerve α-syn deposits in 44 patients with synucleinopathy: 15 idiopathic Parkinson’s disease (IPD), 12 dementia with Lewy Bodies (DLB), 5 pure autonomic failure (PAF) and 12 multiple system atrophy (MSA). Ten healthy subjects were used as controls. Antibodies against native α-syn, C-terminal α-syn epitopes such as phosphorylation at serine 129 (p-syn) and to conformation-specific for α-syn mature amyloid fibrils (syn-F1) were used. We found that p-syn showed the highest sensitivity and specificity in disclosing skin α-syn deposits. In MSA abnormal deposits were only found in somatic fibers mainly at distal sites differently from PAF, IPD and DLB displaying α-syn deposits in autonomic fibers mainly at proximal sites. PAF and DLB showed the highest p-syn load with a widespread involvement of autonomic skin nerve fibers. In conclusion: 1) p-syn in skin nerves was the optimal marker for the in vivo diagnosis of synucleinopathies; 2) the localization and load differences of aggregates may help to identify specific diagnostic traits and support a different pathogenesis among synucleinopathies.
Abnormal Stop Band Behavior Induced by Rotational Resonance in Flexural Metamaterial
Authors: Lee Sung Won , Oh Joo Hwan
Published: September 2018

This paper investigates abnormal stop band behavior of resonance-based flexural elastic metamaterials under the rotational resonance motion. Due to the unique physics of flexural waves, we found that the stop band generated by the rotational resonance motion exhibits peculiar behavior which are quite different from general belief – it is shown that the negativity due to the rotational resonance does not provide any stop bands and the stop band generation due to the rotational resonance is governed by totally different band gap condition. To explain the peculiar behavior, a discrete Timoshenko beam model with both effective mass and rotational inertia as independent variables is introduced, and the wave behaviors of resonance-based flexural elastic metamaterial are precisely and fully described. The unique band gap condition, including the peculiar behavior, is derived with numerical validations. We expect our new model can provide a strong background for various flexural elastic metamaterials which can be effectively applied in various vibration devices.
Rapid Fabrication of Microporous BaTiO3/PDMS Nanocomposites for Triboelectric Nanogenerators through One-step Microwave Irradiation
Authors: Jang Shin , Oh Je Hoon
Published: September 2018

Even though porous elastomers and elastomeric nanocomposites have shown many advantages for triboelectric nanogenerators (TENGs), their fabrication techniques are relatively complicated, inefficient, and time-consuming. In this work, we introduced a simple, efficient and rapid concept to fabricate porous polydimethylsiloxane (PDMS) nanocomposites. PDMS nanocomposites with various porous structure were produced within a few minutes through just one-step microwave irradiation without any post-processing. Three solvents with different boiling points were selected as sacrificial materials to control porous structure. To fabricate nanocomposites, BaTiO3 (BT) nanoparticles were mixed into the uncured PDMS and sacrificial solvent mixture. Additionally, Ni nanoparticles were also used to understand the effect of embedded material’s property on porous structure. The porous BT/PDMS nanocomposites fabricated via microwave irradiation greatly enhanced the electrical performance of TENGs as compared to a pure solid elastomer. The present study provides a simple, rapid and inexpensive approach for fabricating TENGs based on porous elastomeric nanocomposites.
Simple separation of good quality bovine oocytes using a microfluidic device
Authors: Iwasaki Wataru , Yamanaka Kenichi , Sugiyama Daisuke , Teshima Yuki , Briones-Nagata Maria Portia , Maeki Masatoshi , Yamashita Kenichi , Takahashi Masashi , Miyazaki Masaya
Published: September 2018

We fabricated a simple microfluidic device for separation of bovine oocytes based on the oocyte quality to improve the conception rate of in vitro fertilization (IVF) by using good quality oocytes. The microfluidic device separates oocytes based on sedimentation rate differences in a sucrose buffer, which is dependent on oocyte quality. The microfluidic device has a 700 µm width, 1 mm height, and 10 mm long separation channel. Oocytes were injected from the upper half of the separation channel, and they flowed while sinking. The outlets of the separation channel were divided into upper and lower chambers. Good quality oocytes settled faster than poor quality oocytes in sucrose buffer; therefore, good quality oocytes were collected from the lower outlet. We performed IVF after the microfluidic separation of oocytes. The developmental rate to blastocysts of oocytes collected from the lower outlet was significantly higher than those collected from the upper outlet (36.0% vs. 14.1%). This result was comparable to that in the BCB staining method performed as a comparison method (BCB+ : 35.7%, BCB−: 15.4%). These findings indicate that our microfluidic device could be applied to oocyte separation and contribute to improvement of in vitro embryo production system.
Comparative assessment of autochthonous bacterial and fungal communities and microbial biomarkers of polluted agricultural soils of the Terra dei Fuochi
Authors: Ventorino Valeria , Pascale Alberto , Adamo Paola , Rocco Claudia , Fiorentino Nunzio , Mori Mauro , Faraco Vincenza , Pepe Olimpia , Fagnano Massimo
Published: September 2018

Organic and inorganic xenobiotic compounds can affect the potential ecological function of the soil, altering its biodiversity. Therefore, the response of microbial communities to environmental pollution is a critical issue in soil ecology. Here, a high-throughput sequencing approach was used to investigate the indigenous bacterial and fungal community structure as well as the impact of pollutants on their diversity and richness in contaminated and noncontaminated soils of a National Interest Priority Site of Campania Region (Italy) called “Terra dei Fuochi”. The microbial populations shifted in the polluted soils via their mechanism of adaptation to contamination, establishing a new balance among prokaryotic and eukaryotic populations. Statistical analyses showed that the indigenous microbial communities were most strongly affected by contamination rather than by site of origin. Overabundant taxa and Actinobacteria were identified as sensitive biomarkers for assessing soil pollution and could provide general information on the health of the environment. This study has important implications for microbial ecology in contaminated environments, increasing our knowledge of the capacity of natural ecosystems to develop microbiota adapted to polluted soil in sites with high agricultural potential and providing a possible approach for modeling pollution indicators for bioremediation purposes.
Human hepatic 3D spheroids as a model for steatosis and insulin resistance
Authors: Kozyra Mikael , Johansson Inger , Nordling Åsa , Ullah Shahid , Lauschke Volker M. , Ingelman-Sundberg Magnus
Published: September 2018

Non-alcoholic fatty liver disease (NAFLD) has emerged as a public health concern as reflected in its widespread distribution in the general population. Yet, treatment options are scarce which is at least in part due to lack of reliable human in vitro disease models. Here, we report a human hepatic 3D spheroid system cultured under defined chemical conditions that has the potential to mimic steatotic conditions in a reversible manner, useful for identification of novel drug treatment conditions. Primary human hepatocytes (PHH) from different donors were cultured as spheroid microtissues in physiological in vivo -like culture conditions. Hepatic steatosis was induced over the course of three weeks in culture by supplementing the culture medium with pathophysiological concentrations of free fatty acids, carbohydrates and insulin. Effects of steatosis in the 3D system were evaluated on transcriptional, metabolomic and lipidomic levels. Free fatty acids on one hand as well as a combination of insulin and monosaccharides, promoted lipid accumulation in hepatocytes and increased expression of lipogenic genes, such as fatty acid synthase. This milieu also promoted development of insulin resistance within 2 weeks as manifested by an increase in gluconeogenic and insulin resistance markers, which are observed in type 2 diabetes mellitus and metabolic syndrome. Induced steatosis was reversible after withdrawal of lipogenic substrates and a further reduction in cellular fat content was observed following treatment with different antisteatotic compounds, such as metformin, glucagon, olaparib and antioxidants. Taken together, these results demonstrate that the 3D hepatic spheroids can serve as a valuable, HTS compatible model for the study of liver steatosis and facilitate translational discovery of novel drug targets.
Nanomaterials for photoacoustic imaging in the second near-infrared window
Authors: Huang Kai , Zhang Yifan , Lin Jing , Huang Peng
Published: September 2018

The use of nanomaterials as contrast agents for photoacoustic imaging in the NIR-II window enables enhanced imaging quality with deeper tissue penetration.
Effect of a ZrO2 support on Cu/Fe2O3–CeO2/ZrO2 catalysts for NO removal by CO using a rotary reactor
Authors: Zhang Xingyu , Cheng Xingxing , Ma Chunyuan , Wang Xiuping , Wang Zhiqiang
Published: September 2018

The effect of a ZrO2 support on the activity and adsorption behavior of Cu/Fe2O3–CeO2/ZrO2 catalysts was promoted by the oxygen vacancy.
Determination of nitrite ions in environment analysis with a paper-based microfluidic device
Authors: Liu Yu-Ci , Hsu Chia-Hui , Lu Bing-Jyun , Lin Peng-Yi , Ho Mei-Lin
Published: September 2018

A new microfluidic paper-based analytical device, a (Ag-μPAD)-based chemiresistor composed of silver ink, has been developed for the selective, sensitive, and quantitative determination of nitrite ions in environmental analysis.
Slow magnetic relaxation in a Tb(iii)-based coordination polymer
Authors: Yoshida Takefumi , Narayana Yemineni S. L. V. , Abe Hitoshi , Higuchi Masayoshi
Published: September 2018

A Tb(iii)-based coordination polymer (polyTb) was synthesized by complexation of Tb(NO3)3·(6H2O) and 4′,4′′′′-[1,1′-biphenyl]-4,4′-diylbis[6,6′′-bis(ethoxycarbonyl)2′:6′,2′′-terpyridine](L).
In vitro effect of green tea and turmeric extracts on GLP-1 and CCK secretion: the effect of gastrointestinal digestion
Authors: Planes-Muñoz David , López-Nicolás Rubén , González-Bermúdez Carlos A. , Ros-Berruezo Gaspar , Frontela-Saseta Carmen
Published: September 2018

Plant extract activity can be modified by the digestion process.
Characterization of phenolic compounds in tincture of edibleNepeta nuda: development of antimicrobial mouthwash
Authors: Smiljković Marija , Dias Maria Inês , Stojković Dejan , Barros Lillian , Bukvički Danka , Ferreira Isabel C. F. R. , Soković Marina
Published: September 2018

The activity of edibleNepeta nudaL. (Lamiaceae) tincture and Listerine towards a selected group of oral pathogenic microorganisms (4 bacterial and 9 fungal strains) has been explored.
The impact of substrate surface defects on the properties of two-dimensional van der Waals heterostructures
Authors: Kim Se-Yang , Kim Jung Hwa , Lee Sungwoo , Kwak Jinsung , Jo Yongsu , Yoon Euijoon , Lee Gun-Do , Lee Zonghoon , Kwon Soon-Yong
Published: September 2018

The effects of atomic and structural defects on the interlayer properties or configuration in the van der Waals heterostructures have been thoroughly investigated using WS2 flakes directly grown on graphene.
Gold-loaded microspheres via carbosilane–thioether dendrimers as stabilizers and their performance in layer-controllable photonic crystals
Authors: Tong Yu-Long , Zhu Zhijie , Peng Gang , Cui Tingting , Chen Su
Published: September 2018

Layer controllable Au-doped photonic crystals are fabricated based on Au decorated P(St-co-G3Vi) microspheres towards the enhancement of quantum dot fluorescence.
Assembly of cellulose nanocrystals in a levitating drop probed by time-resolved small angle X-ray scattering
Authors: Liu Yingxin , Agthe Michael , Salajková Michaela , Gordeyeva Korneliya , Guccini Valentina , Fall Andreas , Salazar-Alvarez Germán , Schütz Christina , Bergström Lennart
Published: September 2018

The nanoscale assembly of cellulose nanocrystals from 1 vol% up to 38 vol% is investigated by in situ small angle X-ray scattering.
Sub-kT/q switching in In2O3 nanowire negative capacitance field-effect transistors
Authors: Su Meng , Zou Xuming , Gong Youning , Wang Jianlu , Liu Yuan , Ho Johnny C. , Liu Xingqiang , Liao Lei
Published: September 2018

Nanowire based NC-FETs with SS values below 60 mV dec−1 are demonstrated. Short channel devices are fabricated using a self-alignment approach.
Probing Lewis acid–base interactions in single-molecule junctions
Authors: Liu Xunshan , Li Xiaohui , Sangtarash Sara , Sadeghi Hatef , Decurtins Silvio , Häner Robert , Hong Wenjing , Lambert Colin J. , Liu Shi-Xia
Published: September 2018

A new and timely conceptual advance in controlling quantum effects in single molecules via Lewis acid–base interactions is reported.
Enhanced electromagnetic wave absorption induced by void spaces in hollow nanoparticles
Authors: Yan Feng , Kang Jianyu , Zhang Shen , Li Chunyan , Zhu Chunling , Zhang Xitian , Chen Yujin
Published: September 2018

The NiCo2O4 hollow nanoparticles, with diameter and wall thickness of merely 10 and 2.5 nm, respectively, were anchored on the graphene surface, showing excellent electromagnetic wave absorption property.
Organic amine-mediated free-radical carbocyclization reactions of 2,2,2-trihalogeno-substitutedN-(2-alkynylphenyl)acetamides
Authors: Chuang Tsung-Han , Chuang Che-Ping
Published: September 2018

An organic amine-mediated carbocyclization reaction for the synthesis of 3-halogeno-substituted 4-benzoylquinolin-2-(1H)-ones is described.
Enzymatically degradable star polypeptides with tunable UCST transitions in solution and within layer-by-layer films
Authors: Zhou Qing , Palanisamy Anbazhagan , Albright Victoria , Sukhishvili Svetlana A.
Published: September 2018

Enzymatically degradable star polypeptides exhibit robust UCST-type transitions in aqueous solution and within layer-by-layer assembled films.
New potential model for atomic-scale peeling of armchair graphene: toward understanding of micrometer-scale peeling
Authors: Okamoto Ryoji , Yamasaki Koki , Sasaki Naruo
Published: September 2018

Reduction of computation time of nanomechanics by atomic-scale modeling.
Unexpected room-temperature phosphorescence from a non-aromatic, low molecular weight, pure organic molecule through the intermolecular hydrogen bond
Authors: Fang Manman , Yang Jie , Xiang Xueqin , Xie Yujun , Dong Yongqiang , Peng Qian , Li Qianqian , Li Zhen
Published: September 2018

The first example of a pure non-aromatic organic small molecule, cyanoacetic acid (CAA), with unexpected persistent RTP behavior is reported, which possesses the RTP lifetime as long as 862 ms.
Selective binding of matrix metalloproteases MMP-9 and MMP-12 to inhibitor-assisted thermolysin-imprinted beads
Authors: Schauer Nicole , Dinc Mehmet , Raabe Bastian , Hummel Tim , Müller Marlen , Sobek Harald , Mizaikoff Boris
Published: September 2018

Dummy-imprinted polymers were prepared for selectively binding metalloproteases MMP-9 and MMP-12 in CHO cell culture supernatant.
Group-IVA element-doped SrIn2O4 as potential materials for hydrogen production from water splitting with solar energy
Authors: Huang Hai-Cai , Yang Chuan-Lu , Wang Mei-Shan , Ma Xiao-Guang , Yi You-Gen
Published: September 2018

Band gap engineering can efficiently improve the photocatalytic activity of semiconductors for hydrogen generation from water splitting.
Low molecular weight galactomannans-based standardized fenugreek seed extract ameliorates high-fat diet-induced obesity in miceviamodulation of FASn, IL-6, leptin, and TRIP-Br2
Authors: Kandhare Amit D. , Bandyopadhyay Debasish , Thakurdesai Prasad A.
Published: September 2018

Obesity is a complex, chronic metabolic disorder and its prevalence is increasing throughout most of the world.
Synthesis of a lignin-based phosphorus-containing flame retardant and its application in polyurethane
Authors: Zhang Y. M. , Zhao Q. , Li L. , Yan R. , Zhang J. , Duan J. C. , Liu B. J. , Sun Z. Y. , Zhang M. Y. , Hu W. , Zhang N. N.
Published: September 2018

In this work, new lignin-based flame retardant LHDs were successfully synthesized through the reaction between lignin, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and hexamethylene diisocyanate (HDI).
The enhanced osteogenesis and osteointegration of 3-DP PCL scaffolds via structural and functional optimization using collagen networks
Authors: Wang Jinbing , Lin Chucheng , Gao Xin , Zheng Zhiwei , Lv Mimgming , Sun Jian , Zhang Zhiyong
Published: September 2018

Optimal balance between biological activity and mechanical stability should be meticulously considered during scaffold design for bone tissue engineering applications.
Spontaneous growth of 2D coordination polymers on functionalized ferromagnetic surfaces
Authors: Mattera Michele , Rubio-Giménez Víctor , Delprat Sophie , Mattana Richard , Seneor Pierre , Tatay Sergio , Forment-Aliaga Alicia , Coronado Eugenio
Published: September 2018

2D coordination polymers grow spontaneously on reactive surfaces due to surface oxidation. The growth process is observed in real time.
Carbene-catalyzed enantioselective oxidative coupling of enals and di(hetero)arylmethanes
Authors: Chen Qiao , Zhu Tingshun , Majhi Pankaj Kumar , Mou Chengli , Chai Huifang , Zhang Jingjie , Zhuo Shitian , Chi Yonggui Robin
Published: September 2018

An N-heterocyclic carbene-catalyzed direct oxidative coupling of enals and di(hetero)arylmethanes allows for quick access to optical pure benzimidazole-fused lactams.
Mo-doped TiO2photoanodes using [Ti4Mo2O8(OEt)10]2bimetallic oxo cages as a single source precursor
Authors: Regue Miriam , Armstrong Katherine , Walsh Dominic , Richards Emma , Johnson Andrew L. , Eslava Salvador
Published: September 2018

[Ti4Mo2O8(OEt)10]2cages were used for the formation of Mo-doped TiO2photoanodes with better performance than pure TiO2.
Microstructure and doping effect on the enhancement of the thermoelectric properties of Ni doped Dy filled CoSb3skutterudites
Authors: Trivedi Vikrant , Battabyal Manjusha , Balasubramanian Priyadarshini , Muralikrishna G. Mohan , Jain Pawan Kumar , Gopalan Raghavan
Published: September 2018

The thermoelectric properties of nanostructured Ni doped Dy filled CoSb3skutterudites (Dy0.4Co4−xNixSb12(x= 0, 0.4, and 0.8)) have been reported.
Nitrogen-doped highly dense but porous carbon microspheres with ultrahigh volumetric capacitance and rate capability for supercapacitors
Authors: Zhou Junshuang , Hou Li , Lian Jie , Cheng Wenbo , Wang Dong , Gou Huiyang , Gao Faming
Published: September 2018

Controlling the dosage ratio of KOH to samples for an optimized porous structure with both high gravimetric capacitance and high volumetric capacitance.
A simple method for phase control in two-dimensional perovskite solar cells
Authors: Ma Chunqing , Lo Ming-Fai , Lee Chun-Sing
Published: September 2018

Suppressed low-n phases by using DMSO enable high performance GAMA4Pb4I13 PSCs.
Vapor-phase hydrothermal transformation of a nanosheet array structure Ni(OH)2 into ultrathin Ni3S2 nanosheets on nickel foam for high-efficiency overall water splitting
Authors: Liu Guoqiang , Sun Zhongti , Zhang Xian , Wang Haojie , Wang Guozhong , Wu Xiaojun , Zhang Haimin , Zhao Huijun
Published: September 2018

Ultrathin Ni3S2 nanosheets grown on nickel foam are thermodynamically favourable for hydrazine adsorption and oxidation, exhibiting superior H2 generation performance.
Semi-transparent perovskite solar cells: unveiling the trade-off between transparency and efficiency
Authors: Yuan Ligang , Wang Zhaowei , Duan Ruomeng , Huang Peng , Zhang Kaicheng , Chen Qiaoyun , Allam Nageh K. , Zhou Yi , Song Bo , Li Yongfang
Published: September 2018

Thick, wide-bandgap materials as photoactive layers in semi-transparent Pero-SCs realized >20% AVT and ∼10% PCE.
Crisscross-designed piezoresistive strain sensors with a cracked microtectonic architecture for direction-selective tensile perception
Authors: Jang Hayeong , Baek Seolhee , Choi Giheon , Oh Seungtaek , Lim Ho Sun , Jang Yunseok , Lee Hwa Sung
Published: September 2018

Flexible strain sensors are a key component of electronic skin (e-skin), a technology that is currently receiving considerable research attention with a view to future applications ranging from human healthcare monitoring to robotic skins and environmental risk detection.
Association between lung cancer risk and inorganic arsenic concentration in drinking water: a dose–response meta-analysis
Authors: Yuan Tanwei , zhang Hongbo , Chen Bin , Zhang Hong , Tao Shasha
Published: September 2018

High dose arsenic in drinking water (≥100 μg L−1) is known to induce lung cancer, but lung cancer risks at low to moderate arsenic levels and its dose–response relationship remains inconclusive.
Development of Phonological, Lexical, and Syntactic Abilities in Children With Cochlear Implants Across the Elementary Grades
Authors: Nittrouer Susan , Muir Meganne , Tietgens Kierstyn , Moberly Aaron C. , Lowenstein Joanna H.
Published: September 2018

Purpose

This study assessed phonological, lexical, and morphosyntactic abilities at 6th grade for a group of children previously tested at 2nd grade to address 4 questions: (a) Do children with cochlear implants (CIs) demonstrate deficits at 6th grade? (b) Are those deficits greater, the same, or lesser in magnitude than those observed at 2nd grade? (c) How do the measured skills relate to each other? and (d) How do treatment variables affect outcome measures?

Participants

Sixty-two 6th graders (29 with normal hearing, 33 with CIs) participated, all of whom had their language assessed at 2nd grade.

Method

Data are reported for 12 measures obtained at 6th grade, assessing phonological, lexical, and morphosyntactic abilities. Between-groups analyses were conducted on 6th-grade measures and the magnitude of observed effects compared with those observed at 2nd grade. Correlational analyses were performed among the measures at 6th grade. Cross-lagged analyses were performed on specific 2nd- and 6th-grade measures of phonological awareness, vocabulary, and literacy to assess factors promoting phonological and lexical development. Treatment effects of age of 1st CI, preimplant thresholds, and bimodal experience were evaluated.

Results

Deficits remained fairly consistent in type and magnitude across elementary school. The largest deficits were found for phonological skills and the least for morphosyntactic skills, with lexical skills intermediate. Phonological and morphosyntactic skills were largely independent of each other; lexical skills were moderately related to phonological skills but not morphosyntactic skills. Literacy acquisition strongly promoted both phonological and lexical development. Of the treatment variables, only bimodal experience affected outcomes and did so positively.

Conclusions

Congenital hearing loss puts children at continued risk of language deficits, especially for phonologically based skills. Two interventions that appear to ameliorate that risk are providing a period of bimodal stimulation and strong literacy instruction.
Performance of two‐way AF relaying with energy harvesting over Nakagami‐m fading channels
Authors: Quoc Bao Vo Nguyen , Van Toan Hoang , Le Khoa N
Published: September 2018

In this study, the authors consider a two‐way amplify‐and‐forward communication system over Nakagami‐m fading environments, where an intermediate relay node harvests energy from its surrounding radio frequency environment using an energy harvesting technique. They propose a novel derivation approach to obtain exact expressions for user outage probability, system outage probability, and upper bound on system ergodic capacity per unit bandwidth over Nakagami‐m fading channels. Monte–Carlo simulation results under Matlab software packages match the proposed analytical analyses confirming the correctness of the proposed derivation approach and the advantage of the system under consideration.
Joint polarisation and frequency diversity for deceptive jamming suppression in MIMO radar
Authors: Zhang Xinxun , Cao Ding , Xu Leilei
Published: September 2018

The joint exploitation of polarisation and frequency diversity is considered here as a way to improve the deceptive jamming suppression capability in multiple‐input multiple‐output (MIMO) radar. The authors explore a special polarisation and frequency diverse MIMO (PFD‐MIMO) radar system here. In the PFD‐MIMO radar system, polarisation and frequency diversity are employed in the transmit array, and two‐dimensional vector sensors are adopted in the receive array to measure the horizontal and vertical components of the received signals. To fully explore the potential of the PFD‐MIMO radar system, the transmitting polarisation and frequency increment are both optimised by maximising the output signal‐to‐interference‐plus‐noise ratio. The simulation results demonstrate that the PFD‐MIMO radar is more robust and exhibits a better performance for deceptive jamming suppression than the frequency diverse array MIMO radar and polarimetric MIMO radar. Moreover, improved deceptive jamming suppression performance is achieved when the transmitting polarisation and frequency increment are both optimised.
Incremental magnetic pulse welding of dissimilar sheet metals
Authors: Psyk Verena , Linnemann Maik , Scheffler Christian , Kurka Petr , Landgrebe Dirk
Published: September 2018

Magnetic pulse welding is a solid state welding process using pulsed magnetic fields resulting from a sudden discharge of a capacitor battery through a tool coil in order to cause a high-speed collision of two metallic components, thus producing an impact-welded joint. The joint is formed at room temperature. Consequently, temperature-induced problems are avoided and this technology enables the use of material combinations, which are usually considered to be non-weldable. The extension of the typically linear weld seam can easily reach several hundred millimetres in length, but only a few millimetres in width. If a larger connected area is required, incremental or sequential magnetic pulse welding is a promising alternative. Here, the inductor is moved relative to the joining partners after the first weld sequence and then another welding process is initiated. Thus, the welded area is extended gradually by arranging multiple adjacent weld seams. This paper demonstrates the feasibility of incremental magnetic pulse welding. Furthermore, the influence of important process parameters on the component quality is investigated and evaluated in terms of geometry and micrographic analysis. Moreover, the suitability of different mechanical testing methods is discussed for determining the strength of the individual weld seams.
Investigation of microstructure and hardness of a rib geometry produced by metal forming and wire-arc additive manufacturing
Authors: Hirtler Markus , Jedynak Angelika , Sydow Benjamin , Sviridov Alexander , Bambach Markus
Published: September 2018

Within the scope of consumer-oriented production, individuality and cost-effectiveness are two essential aspects, which can barely be met by traditional manufacturing technologies. Conventional metal forming techniques are suitable for large batch sizes. If variants or individualized components have to be formed, the unit costs rise due to the inevitable tooling costs. For such applications, additive manufacturing (AM) processes, which do not require tooling, are more suitable. Due to the low production rates and limited build space of AM machines, the manufacturing costs are highly dependent on part size and batch size. Hence, a combination of both manufacturing technologies i.e. conventional metal forming and additive manufacturing seems expedient for a number of applications. The current study develops a process chain combining forming and additive manufacturing. First, a semi-finished product is formed with forming tools of reduced complexity and then finished by additive manufacturing. This research investigates the addition of features using AlSi12 created by Wire Arc Additive Manufacturing (WAAM) on formed EN-AW 6082 preforms. By forming, the strength of the material was increased, while this effect was partly reduced by the heat input of the WAAM process.
The influence of microstructure deformation on the corrosion resistance of cold formed stainless steel
Authors: Bösing Ingmar , Herrmann Marius , Bobrov Ilya , Thöming Jorg , Kuhfuss Bernd , Epp Jérémy , Baune Michael
Published: September 2018

Rotary swaging is an incremental cold forming process to produce axisymmetric workpieces from rods and tubes. The process also induces changes of the microstructure of the material depending on the process parameters. This in turn influences the mechanical properties like hardness as well as the electrochemical properties. As a result of changed electrochemical properties, the passivity of the material and thus the corrosion behavior changes. In order to investigate the influence of rotary swaging on the corrosion behavior of the stainless steel AISI304, deformed micro parts are electrochemically analyzed. The measurements reveal a dependency of corrosion rate and impedance on both feed velocity and final diameter of the rotary swaging process. A higher feed velocity decreases the corrosion rate and increases the impedance indicating a better resistance against corrosion as a side effect of rotary swaging.
Numerical modelling of T-pipe joints forming
Authors: Bartnicki Jarosław
Published: September 2018

This paper presents results of numerical calculations of T-pipe joints (tee) forming process for a wide scope of industrial applications. FEM analyses were conducted for the chosen process technological parameters and tools designs. The kinematics of metal flow in the area of the formed flanges was analysed. Distributions of stresses, strains and damage criterion during forming were determined. Calculated values of forces and moments acting on tools and workpieces allow for designing of tools geometry for experimental verification of the proposed forming process.
Push-bending Process and Forming Quality of Stainless-steel Tubes
Authors: Guo-qing Chen , Jian Yang , Hong-xiang Li , Xue-song Fu , Rui Tang , Wen-long Zhou
Published: September 2018

The push-bending process of stainless-steel tubes was investigated by using the experimental method and finite element (FE) analysis based on the commercial software MSC.MARC. The effects of the processing parameters and the lubricating condition on the forming quality of as-obtained ASTM304 tubes were discussed. The results demonstrated that the experiment results were consistent with the simulation both in deformation behaviour and the stress distribution during the push-bending process, which verified the reliability of the established FE-model. The results also show that the maximum residual stress concentrates in the middle of tubes, the residual strain on both the external side increases firstly, then decrease, and increase again with the increase of the location angel. After the push-bending, the interior wall thickness increases while the exterior wall thickness decreases. When the relative bending radius is larger, smaller variation of wall thickness will be obtained. With the increase of the friction coefficient, the wall thickness thinning rate will decrease. With the increase of the pushing speed, the wall thickness thinning rate decrease a little while the thickening rate increases slightly. When push-bending of the large radius tubes, a good lubricating condition can reduce the wall thickening problem at the intrados, which will ensure a better forming quality.
Keyword. Bending, Quality control, Simulation
Micro formed holographic security features in steel
Authors: Uhlmann Eckart , Schulze Stephanie , Frenzel née , Polte Julian , Hein Christoph , Matthiesen Johannes , Böge Manfred
Published: September 2018

Counterfeiting, with a global trade volume of approximately 450 billion euro a year compromises business results of companies in all industrial segments. At worst, product plagiarism causes severe damages to the individual brand reputation due to product defects or liability issues. Therefore, product integration of inseparable and unique security features is essential for a preserving market share in all manufacturing branches. This paper presents a novel approach regarding a replication technology for the manufacturing of holographic security features. Using a microstructured aluminium substrate with holographic properties as a base material, a forming die is manufactured by a combination of physical vapour deposition (PVD) and galvanic coating processes. Furthermore, a process adapted hardness progression between individual layers was created. By the use of this die, the forming of a holographic microstructure into high strength aluminium alloy (3.3547) and spring steel (1.1248) could be demonstrated within a preliminary study.
Generation of micro channels in AlMg4.5Mn0.7 sheets using a vibration-assisted micro forming process
Authors: Müller Benedikt , Schubert Andreas
Published: September 2018

Micro forming can be used for a highly efficient manufacturing of small parts like screws or caps. Because of the small dimensions of the structures, high stresses and forming forces occur, especially in the case of micro bulk forming. In addition, the influence of friction is significantly higher compared to macro forming processes. A typical example of small structures are micro channels. An approach for the reduction of the necessary forming force to obtain lower loads on the tool consists in a vibration-assisted micro forming process. As vibration source, a piezo power module is placed directly in the force axis of the forming press. For the investigations, micro channels with a depth of more than 300 μm and a width of 300 μm are formed into 1.5 mm thick AlMg4.5Mn0.7 aluminium alloy sheets. The focus of the research lies in the influence of the process parameters like frequency and oscillation amplitude onto the material flow and the achieved channel depths. To investigate a possible influence on the friction conditions due to the vibration assistance, different lubrication conditions are applied. First results show a channel depth increase of 12 % compared to samples formed without vibration assistance.
Forming of micro gears by compressing a pure copper sheet through its thickness
Authors: Asghari Ganji Amirreza , Bakhshi-Jooybari Mohammad , Gorji Hamid
Published: September 2018

Currently, micro gears are mostly fabricated by LIGA technology and micromachining. These processes have some limitations. Forming processes not only satisfy mass production and appropriate productivity rate but also present superior mechanical properties. A major problem preventing the bulk micro metal forming is the preparation of micro billets and their precise transfer between the forming stages. The purpose of this study is developing a method to form a micro gear without the need to a separate micro billet preparation. In this paper, pure copper sheets were compressed into the predetermined micro gear profiles though their thicknesses, so that there is no need for preparation of micro billets and also its troublesome transforming. The tests were performed at room temperature, in two cases of single extrusion process and extrusion-forging process. Micro gears with 6 teeth and 250μm in module were formed completely with good repeatability in both the cases. A major advantage of the proposed study compared with the blanking process is that, in blanking, the process is merely cutting the edges, while here the material fills the die by deformation. Thus, better mechanical properties will be achieved. Measuring the micro-hardness of the formed parts in comparison with raw material, verified this point. In general, the micro-hardnesses of combined extrusion-forging parts were higher than those of single extrusion ones in the same positions on the micro gears surface.
Fabrication of WC-TiC-Co Cemented Carbide at Different Heating Rate by Micro-FAST process
Authors: Chen Yitong , Yang Yi , Yang Gang , Wang Libo , Wu Mingxia
Published: September 2018

As demands on miniature products increase significantly, a rapid prototyping and production
system for highly flexible and cost-efficient production of micro components made from a wide range of materials is needed. In present work, the Micro-forming Fields Activated Sintering Technology (Micro-FAST) with the coupling effects of electrical and pressure fields as the dominant driving force, has been proved to be very successful in the fabrication of the nearly full-density micro-cylinder parts from WC-8Co-xTi-nC powders (x=4, n=2 or x=6, n=0). The influence of heating rate and composition of titanium and carbon has been investigated. Based on the analysis of the relative density, microstructure and mechanical properties, high density (up to 99.7%), fine grain sizes and good mechanical properties could be obtained by Micro- FAST to sinter WC-TiC-Co Cemented Carbide bodies under a low sintering temperature (1200 ℃).
A New Cross Wedge Rolling Process for Producing Rail Axles
Authors: Pater Zbigniew , Tomczak Janusz
Published: September 2018

Rail axles are large-size parts produced in large batches. Currently, these parts are produced by metal forming techniques such as rotary forging, open die forging with hydraulic presses and open die hammer forging (minimum ram weight: 3 Mg). Nevertheless, not only are the above methods far from being efficient, they also lack accuracy (open die forging). As a result, new techniques for producing rail axles are constantly developed. One of such alternative techniques is based on the use of cross wedge rolling (CWR), which is the subject of the present study. An innovative roll design for producing rail axles by CWR is proposed. The rolls are provided with three pairs of wedge tools that act simultaneously on the workpiece and form the part in one revolution of the rolls, i.e., during 20 s. The numerical modelling of a CWR process with the proposed roll design reveals that the solution can be used to produce railway axles with the desired geometry. This technique, however, requires relatively high loads and torques. To decrease the force parameters, the forming process was modified and ran in two operations. The first operation consists in forming the central step of the workpiece while the other one involves the formation of steps on the ends of the workpiece. The results of the new simulation show a significant decrease in the loads and torques, which is caused, among others, by reducing the nominal diameter of the rolls from 1600 mm to 1200 mm. The numerical findings can be used to design a rolling mill for producing rail axles.
Experimental Investigation on Creep Forming of A New Al-Li-Cu-Mg Alloy Plate
Authors: Xuepiao BAI , Hong LI , Yuansong ZENG , Mingtao WANG , Fenggong LYU , Qiang MENG
Published: September 2018

Fundamental creep fonning experiments on a new Al-Li-Cu-Mg alloy plate were carried out to investigate the forming parameters of integral reinforced panel with thin skin. The effects of process parameters on springback ratio and material properties are investigated by orthogonal design method. The result data show that the springback ratio decreases with the temperature and tune period of creep age forming, increases with radius of pre-bend. The tension strength and yield strength increase and then decrease with temperature of creep forming. The elongation decreases with the temperature of creep forming. A mathematical equation model for springback ratio is proposed and resolved thorough regression analysis method. A typical structure of fuselage panel is creep formed, which verified the effectiveness and accuracy of the mathematical equation model.
Experimental studies of the efficient use of flexible tool in creep age forming
Authors: Rong Qi , Li Yong , Sun Xiaoguang , Shi Zhusheng , Meng Lichun , Lin Jianguo
Published: September 2018

Application of a newly developed flexible forming tool to creep age forming (CAF) process has been investigated in this study. The flexible tool mainly consists of sparsely distributed forming pins, splines and elastomeric sheet. The effect of key factors related to the forming tool on the shape of the formed parts has been studied through various CAF experiments. The key factors investigated in this study include: the interval between forming pins, the arrangement of pins, the accuracy requirement of pin height and the material of splines. It has been found that reducing the interval between pins can efficiently smooth the shape of CAFed plates. The feasibility of asymmetric arrangement of pins has been proven, which can decrease the number of used pins, reduce tool weight, and increase efficiency. The forming results are very sensitive to the pin height, thus the experimental set-up error should be carefully controlled. Additionally, compared with mild steel, spring steel is more suitable as the spline material.
Selective oxidation of tool steel surfaces under a protective gas atmosphere using inductive heat treatment
Authors: Schöler S. , Yilkiran D. , Wulff D. , Özkaya F. , Möhwald K. , Behrens B.-A. , Maier H.J.
Published: September 2018

For the realization of liquid lubricant free forming processes different approaches are conceivable. The priority program 1676 “Dry forming - Sustainable production through dry machining in metal forming” addresses this issue in the context of metal forming processes. The present study reports results from one subproject of the priority program that employs selective oxidization of tool steel surfaces for the implementation of a dry sheet metal deep drawing process. Within the present study, specimen surfaces of the tool steel (1.2379) were heat-treated to optimize their tribological properties with respect to sliding wear behaviour in contact with drawn sheet metal (DP600+Z). The heat treatment was designed to result in the formation of selective oxide layers that can act as friction reducing separation layers. The heating setup employed an inductive heating under protective gas atmosphere. Selective oxidation was realized by controlling the residual oxygen content. Specifically, the specimens were heated in the near-surface region just above the annealing temperature, thus avoiding the degradation of mechanical properties in the bulk. Evaluation of hardness along cross-sections of each specimen revealed suitable initial temperatures for the inductive heat treatment. Oxide layer systems were analyzed regarding their tribological sliding wear behaviour after selective oxidation, as well as their morphology and chemical composition before and after the sliding wear tests.
Influence of the surface microstructure on the adhesion of a CVD-diamond coating on steel with a CrN interlayer
Authors: Prieske Markus , Börner Richard , Schubert Andreas
Published: September 2018

forming tool coating. Most of the forming tools are made of steel, so that especially the coatability of steel by a polycrystalline diamond coating would rise the range of fields of application. The polycrystalline CVD-diamond coatings are deposited by a laser induced plasma CVD process, without a vacuum chamber. Various surface microstructures were investigated regarding their influence on the residual stresses to prevent a flaking of the coating: on the one hand, deterministic structures generated by ultrasonic vibration assisted milling (UVAM) and on the other hand, stochastic structures manufactured by blasting and polishing processes. For the UVAM, a surface prediction tool was used to design the surface microstructure beforehand. All steel substrates (material no. 1.2379) were coated in one batch by high-power impulse magnetron sputtering with a chromium nitride coating with a thickness of 2.4 μm. The specimens were analysed by laser microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Raman spectroscopy. None of the microstructures investigated in this study was able to prevent delamination of the coating entirely. It could be shown that a roughness higher than Sa 0.1μm supports the interlocking between coating and surface as well as that sharp peaks inhibit a homogenous diamond coating deposition.
Inverting Prediction Models in Micro Production for Process Design
Authors: Gralla Phil , Piotrowska-Kurczewski Iwona , Rippel Daniel , Lütjen Michael , Maaß Peter
Published: September 2018

Databased prediction models are used to estimate a possible outcome for previously unknown production parameters. These forward models enable to test new production designs and parameters virtually before applying them in the real world. Cause-effect networks are one way to generate such a prediction model. Multiple inputs and stages are being connected to one large prediction model. The functional behaviour and correlation of inputs as well as outputs is obtained through data based learning. In general, these models are non-linear and not invertible, especially for micro cold forming processes. While already being useful in process design, such models have their highest impact if inverted to find process parameters for a given output. Combining methods from the mathematical field of inverse problems as well as machine learning, a generalized inverse can be approximated. This allows finding process parameters for a given output without inverting the model directly but still using inherit information of the forward model. In this work, Tikhonov functionals are used to perform a parameter identification. The classical approach is altered by changing the discrepancy term to incorporate tolerances. Thereby, small deviations of a certain pattern are being neglected and the parameter finding process is being stabilized. In addition, different types of regularization are taken into consideration. Besides theoretical aspects of this method, examples are provided to demonstrate advantages and boundaries of an application for the process design in micro cold forming processes.