bluuebunny/crossref_metadata_2025 huggingface dataset:
Computed tomography angiography evaluation of acute limb ischemia
Authors: Wallace Alex , Pershad Yash , Saini Aman , Alzubaidi Sadeer , Naidu Sailendra , Knuttinen Grace , Oklu Rahmi
Published: October 2018

Abstract. Acute limb ischemia (ALI), a subclass of critical limb ischemia, is a medical emergency. The cause of ALI is usually thrombotic or embolic in nature, and the specific etiology often dictates the appropriate therapy. While the diagnosis is a clinical with common presenting symptoms, advances in ultrasound, computed tomography, and magnetic resonance technology have impacted the diagnosis and subsequent therapy. In ALI, the time to revascularization is critical and computed tomography angiography (CTA) provides a highly sensitive and specific technique for rapidly identifying occlusions and precisely defining vascular anatomy prior to interventions. In patients with significant renal disease, magnetic resonance angiography with or without contrast provides effective alternatives at the expense of imaging time. Treatment can include a variety of endovascular or surgical interventions, including thromboembolectomy, angioplasty, or bypass. Proper evaluation of the etiology of the ischemia, affected vasculature, and medical history is critical to select appropriate treatment and improve patient outcomes. Here, we examine the presentation, evaluation, and treatment of ALI and the role of CTA in diagnosis and therapy.
Suicidal Ideation and Behavior Among Youth Victims of Sex Trafficking in Kentuckiana
Authors: Frey Laura M. , Middleton Jennifer , Gattis Maurice N. , Fulginiti Anthony
Published: October 2018

Abstract. Background: Youth experiencing homelessness are at risk for sex trafficking and mental health concerns. Aims: More information is needed to elucidate the prevalence and characteristics of suicidal ideation and behavior among youth experiencing sex trafficking. Method: The present study examined suicidal ideation and behavior in a convenience sample of 128 youths experiencing homelessness aged 12–25 years in metropolitan Louisville, Kentucky, and southern Indiana. Participants were asked seven questions regarding suicidal ideation and attempts as part of an enhanced version of the 60-item Youth Experiences Survey (YES). Results: Approximately 53% of the sample reported experiencing suicidal ideation at some point in their lifetime and the odds of a youth experiencing homelessness who had experienced sex trafficking reporting suicidal ideation was 3.87 times higher than the odds of a youth experiencing homelessness who had not experienced sex trafficking. Additionally, of those who reported experiencing suicidal ideation, the majority (84.4%) reported they had attempted suicide in their lifetime. Limitations: This study relied on a convenience sample of youth receiving services in the Kentuckiana region and brief, self-report measures yielding categorical data. Conclusion: Programs servicing youth experiencing homelessness should require additional training and resources regarding the identification, screening, and assessment of youth who are at risk of or who have experienced sex trafficking in order to more quickly connect youth with much-needed, trauma-informed services.
Estimating the Permeability of Naturally Structured Soil From Percolation Theory and Pore Space Characteristics Imaged by X‐Ray
Authors: Koestel John , Dathe Annette , Skaggs Todd H. , Klakegg Ove , Ahmad Muhammad Arslan , Babko Maryia , Giménez Daniel , Farkas Csilla , Nemes Attila , Jarvis Nicholas
Published: October 2018

The saturated hydraulic conductivity of soil, Ks, is a critical parameter in hydrological models that remains notoriously difficult to predict. In this study, we test the capability of a model based on percolation theory and critical path analysis to estimate Ks measured on 95 undisturbed soil cores collected from contrasting soil types. One parameter (the pore geometry factor) was derived by model fitting, while the remaining two parameters (the critical pore diameter, dc, and the effective porosity) were derived from X‐ray computed tomography measurements. The model gave a highly significant fit to the Ks measurements (p < 0.0001) although only ~47% of the variation was explained and the fitted pore geometry factor was approximately 1 to 2 orders of magnitude larger than various theoretical values obtained for idealized porous media and pore network models. Apart from assumptions in the model that might not hold in reality, this could also be attributed to experimental error induced by, for example, air entrapment and changes in the soil pore structure occurring during sample presaturation and the measurement of Ks. Variation in the critical pore diameter, dc, was the dominant source of variation in Ks, which suggests that dc is a suitable length scale for predicting soil permeability. Thus, from the point of view of pedotransfer functions, it could be worthwhile to direct future research toward exploring the correlations of dc with basic soil properties and site attributes.
Controlling reaction pathways of selective C–O bond cleavage of glycerol
Authors: Wan Weiming , Ammal Salai C. , Lin Zhexi , You Kyung-Eun , Heyden Andreas , Chen Jingguang G.
Published: October 2018

The selective hydrodeoxygenation (HDO) reaction is desirable to convert glycerol into various value-added products by breaking different numbers of C–O bonds while maintaining C–C bonds. Here we combine experimental and density functional theory (DFT) results to reveal that the Cu modifier can significantly reduce the oxophilicity of the molybdenum carbide (Mo2C) surface and change the product distribution. The Mo2C surface is active for breaking all C–O bonds to produce propylene. As the Cu coverage increases to 0.5 monolayer (ML), the Cu/Mo2C surface shows activity towards breaking two C–O bonds and forming ally-alcohol and propanal. As the Cu coverage further increases, the Cu/Mo2C surface cleaves one C–O bond to form acetol. DFT calculations reveal that the Mo2C surface, Cu-Mo interface, and Cu surface are distinct sites for the production of propylene, ally-alcohol, and acetol, respectively. This study explores the feasibility of tuning the glycerol HDO selectivity by modifying the surface oxophilicity.
Interplay between Kitaev interaction and single ion anisotropy in ferromagnetic CrI3 and CrGeTe3 monolayers
Authors: Xu Changsong , Feng Junsheng , Xiang Hongjun , Bellaiche Laurent
Published: October 2018

Magnetic anisotropy is crucially important for the stabilization of two-dimensional (2D) magnetism, which is rare in nature but highly desirable in spintronics and for advancing fundamental knowledge. Recent works on CrI3 and CrGeTe3 monolayers not only led to observations of the long-time-sought 2D ferromagnetism, but also revealed distinct magnetic anisotropy in the two systems, namely Ising behavior for CrI3 versus Heisenberg behavior for CrGeTe3. Such magnetic difference strongly contrasts with structural and electronic similarities of these two materials, and understanding it at a microscopic scale should be of large benefits. Here, first-principles calculations are performed and analyzed to develop a simple Hamiltonian, to investigate magnetic anisotropy of CrI3 and CrGeTe3 monolayers. The anisotropic exchange coupling in both systems is surprisingly determined to be of Kitaev-type. Moreover, the interplay between this Kitaev interaction and single ion anisotropy (SIA) is found to naturally explain the different magnetic behaviors of CrI3 and CrGeTe3. Finally, both the Kitaev interaction and SIA are further found to be induced by spin–orbit coupling of the heavy ligands (I of CrI3 or Te of CrGeTe3) rather than the commonly believed 3d magnetic Cr ions.
High-energy spin fluctuation in low-Tc iron-based superconductor LaFePO0.9
Authors: Ishikado Motoyuki , Shamoto Shin-ichi , Kodama Katsuaki , Kajimoto Ryoichi , Nakamura Mitsutaka , Hong Tao , Mutka Hannu
Published: October 2018

Spin fluctuations are widely believed to play an important role in the superconducting mechanisms of unconventional high temperature superconductors. Spin fluctuations have been observed in iron-based superconductors as well. However, in some iron-based superconductors such as LaFePO0.9, they have not been observed by inelastic neutron scattering (INS). LaFePO0.9 is an iron-based superconductor with a low superconducting transition temperature (Tc = 5 K), where line nodes are observed in the superconducting gap function. The line-node symmetry typically originates from sign reversal of the order parameter in spin-fluctuation-mediated superconductivity. This contradiction has been a long-standing mystery of this superconductor. Herein, spin fluctuations were found at high energies such as 30–50 meV with comparable intensities to an optimally doped LaFeAs(O, F). Based on this finding, the line-node symmetry can be explained naturally as spin-fluctuation-mediated superconductivity.
Deep Analysis of Mitochondria and Cell Health Using Machine Learning
Authors: Zahedi Atena , On Vincent , Phandthong Rattapol , Chaili Angela , Remark Guadalupe , Bhanu Bir , Talbot Prue
Published: October 2018

There is a critical need for better analytical methods to study mitochondria in normal and diseased states. Mitochondrial image analysis is typically done on still images using slow manual methods or automated methods of limited types of features. MitoMo integrated software overcomes these bottlenecks by automating rapid unbiased quantitative analysis of mitochondrial morphology, texture, motion, and morphogenesis and advances machine-learning classification to predict cell health by combining features. Our pixel-based approach for motion analysis evaluates the magnitude and direction of motion of: (1) molecules within mitochondria, (2) individual mitochondria, and (3) distinct morphological classes of mitochondria. MitoMo allows analysis of mitochondrial morphogenesis in time-lapse videos to study early progression of cellular stress. Biological applications are presented including: (1) establishing normal phenotypes of mitochondria in different cell types; (2) quantifying stress-induced mitochondrial hyperfusion in cells treated with an environmental toxicant, (3) tracking morphogenesis in mitochondria undergoing swelling, and (4) evaluating early changes in cell health when morphological abnormalities are not apparent. MitoMo unlocks new information on mitochondrial phenotypes and dynamics by enabling deep analysis of mitochondrial features in any cell type and can be applied to a broad spectrum of research problems in cell biology, drug testing, toxicology, and medicine.
Usefulness of peripapillary nerve fiber layer thickness assessed by optical coherence tomography as a biomarker for Alzheimer’s disease
Authors: Sánchez Domingo , Castilla-Marti Miguel , Rodríguez-Gómez Octavio , Valero Sergi , Piferrer Albert , Martínez Gabriel , Martínez Joan , Serra Judit , Moreno-Grau Sonia , Hernández-Olasagarre Begoña , De Rojas Itziar , Hernández Isabel , Abdelnour Carla , Rosende-Roca Maitée , Vargas Liliana , Mauleón Ana , Santos-Santos Miguel A. , Alegret Montserrat , Ortega Gemma , Espinosa Ana , Pérez-Cordón Alba , Sanabria Ángela , Ciudin Andrea , Simó Rafael , Hernández Cristina , Villoslada Pablo , Ruiz Agustín , Tàrraga Lluís , Boada Mercè
Published: October 2018

The use of optical coherence tomography (OCT) has been suggested as a potential biomarker for Alzheimer’s Disease based on previously reported thinning of the retinal nerve fiber layer (RNFL) in Alzheimer’s disease’s (AD) and Mild Cognitive Impairment (MCI). However, other studies have not shown such results. 930 individuals (414 cognitively healthy individuals, 192 probable amnestic MCI and 324 probable AD) attending a memory clinic were consecutively included and underwent spectral domain OCT (Maestro, Topcon) examinations to assess differences in peripapillary RNFL thickness, using a design of high ecological validity. Adjustment by age, education, sex and OCT image quality was performed. We found a non-significant decrease in mean RNFL thickness as follows: control group: 100,20 ± 14,60 µm, MCI group: 98,54 ± 14,43 µm and AD group: 96,61 ± 15,27 µm. The multivariate adjusted analysis revealed no significant differences in mean overall (p = 0.352), temporal (p = 0,119), nasal (p = 0,151), superior (p = 0,435) or inferior (p = 0,825) quadrants between AD, MCI and control groups. These results do not support the usefulness of peripapillary RNFL analysis as a marker of cognitive impairment or in discriminating between cognitive groups. The analysis of other OCT measurements in other retinal areas and layers as biomarkers for AD should be tested further.
Dysregulated gene expression predicts tumor aggressiveness in African-American prostate cancer patients
Authors: Ali Hamdy E. A. , Lung Pei-Yau , Sholl Andrew B. , Gad Shaimaa A. , Bustamante Juan J. , Ali Hamed I. , Rhim Johng S. , Deep Gagan , Zhang Jinfeng , Abd Elmageed Zakaria Y.
Published: October 2018

Molecular mechanisms underlying the health disparity of prostate cancer (PCa) have not been fully determined. In this study, we applied bioinformatic approach to identify and validate dysregulated genes associated with tumor aggressiveness in African American (AA) compared to Caucasian American (CA) men with PCa. We retrieved and analyzed microarray data from 619 PCa patients, 412 AA and 207 CA, and we validated these genes in tumor tissues and cell lines by Real-Time PCR, Western blot, immunocytochemistry (ICC) and immunohistochemistry (IHC) analyses. We identified 362 differentially expressed genes in AA men and involved in regulating signaling pathways associated with tumor aggressiveness. In PCa tissues and cells,NKX3.1, APPL2, TPD52, LTC4S, ALDH1A3andAMD1transcripts were significantly upregulated (p < 0.05) compared to normal cells. IHC confirmed the overexpression of TPD52 (p = 0.0098) and LTC4S (p < 0.0005) in AA compared to CA men. ICC and Western blot analyses additionally corroborated this observation in PCa cells. These findings suggest that dysregulation of transcripts in PCa may drive the disparity of PCa outcomes and provide new insights into development of new therapeutic agents against aggressive tumors. More studies are warranted to investigate the clinical significance of these dysregulated genes in promoting the oncogenic pathways in AA men.
Molecular imaging of telomerase and the enzyme activity-triggered drug release by using a conformation-switchable nanoprobe in cancerous cells
Authors: Shi Hai , Gao Tao , Shi Liu , Chen Tianshu , Xiang Yang , Li Yuanyang , Li Genxi
Published: October 2018

So far, the development of a unique strategy for specific biomolecules activity monitoring and precise drugs release in cancerous cells is still challenging. Here, we designed a conformation-switchable smart nanoprobe to monitor telomerase activity and to enable activity-triggered drug release in cancerous cells. The straightforward nanoprobe contained a gold nanoparticle (AuNP) core and a dense layer of 5-carboxyfluorescein (FAM)-labeled hairpin DNA shell. The 3′ region of hairpin DNA sequence could function as the telomerase primer to be elongated in the presence of telomerase, resulting in the conformational switch of hairpin DNA. As a result, the FAM fluorescence was activated and the anticancer drug doxorubicin (Dox) molecules which intercalated into the stem region of the hairpin DNA sequence were released into cancerous cells simultaneously. The smart method could specifically distinguish cancerous cells from normal cells based on telomerase activity. It also showed a good performance for monitoring telomerase activity in the cytoplasm by molecular imaging and precise release of Dox triggered by telomerase activity in cancerous cells. These advantages may offer a great potential of this method for monitoring telomerase activity in cancer progression and estimating therapeutic effect.
Brain-machine interface cursor position only weakly affects monkey and human motor cortical activity in the absence of arm movements
Authors: Stavisky Sergey D. , Kao Jonathan C. , Nuyujukian Paul , Pandarinath Chethan , Blabe Christine , Ryu Stephen I. , Hochberg Leigh R. , Henderson Jaimie M. , Shenoy Krishna V.
Published: October 2018

Brain-machine interfaces (BMIs) that decode movement intentions should ignore neural modulation sources distinct from the intended command. However, neurophysiology and control theory suggest that motor cortex reflects the motor effector’s position, which could be a nuisance variable. We investigated motor cortical correlates of BMI cursor position with or without concurrent arm movement. We show in two monkeys that subtracting away estimated neural correlates of position improves online BMI performance only if the animals were allowed to move their arm. To understand why, we compared the neural variance attributable to cursor position when the same task was performed using arm reaching, versus arms-restrained BMI use. Firing rates correlated with both BMI cursor and hand positions, but hand positional effects were greater. To examine whether BMI position influences decoding in people with paralysis, we analyzed data from two intracortical BMI clinical trial participants and performed an online decoder comparison in one participant. We found only small motor cortical correlates, which did not affect performance. These results suggest that arm movement and proprioception are the major contributors to position-related motor cortical correlates. Cursor position visual feedback is therefore unlikely to affect the performance of BMI-driven prosthetic systems being developed for people with paralysis.
On the expedient solution of the magneto-hydrodynamic Jeffery-Hamel flow of Casson fluid
Authors: Nourazar S. S. , Nazari-Golshan A. , Soleymanpour F.
Published: October 2018

The equation of magneto-hydrodynamic Jeffery-Hamel flow of non-Newtonian Casson fluid in a stretching/shrinking convergent/divergent channel is derived and solved using a new modified Adomian decomposition method (ADM). So far in all problems where semi-analytical methods are used the boundary conditions are not satisfied completely. In the present research, a hybrid of the Fourier transform and the Adomian decomposition method (FTADM), is presented in order to incorporate all boundary conditions into our solution of magneto-hydrodynamic Jeffery-Hamel flow of non-Newtonian Casson fluid in a stretching/shrinking convergent/divergent channel flow. The effects of various emerging parameters such as channel angle, stretching/shrinking parameter, Casson fluid parameter, Reynolds number and Hartmann number on velocity profile are considered. The results using the FTADM are compared with the results of ADM and numerical Range-Kutta fourth-order method. The comparison reveals that, for the same number of components of the recursive sequences over a wide range of spatial domain, the relative errors associated with the new method, FTADM, are much less than the ADM. The results of the new method show that the method is an accurate and expedient approximate analytic method in solving the third-order nonlinear equation of Jeffery-Hamel flow of non-Newtonian Casson fluid.
Van der Waals junction field effect transistors with both n- and p-channel transition metal dichalcogenides
Authors: Lim June Yeong , Kim Minju , Jeong Yeonsu , Ko Kyeong Rok , Yu Sanghyuck , Shin Hyung Gon , Moon Jae Young , Choi Young Jai , Yi Yeonjin , Kim Taekyeong , Im Seongil
Published: October 2018

Two-dimensional (2D) transition metal dichalcogenides (TMDs)-based van der Waals (vdW) PN junctions have been used for heterojunction diodes, which basically utilize out-of-plane current across the junction interface. In fact, the same vdW PN junction structure can be utilized for another important device application, junction field effect transistors (JFETs), where in-plane current is possible along with 2D–2D heterojunction interface. Moreover, the 2D TMD-based JFET can use both p- and n-channel for low voltage operation, which might be its unique feature. Here we report vdW JFETs as an in-plane current device with heterojunction between semiconducting p- and n-TMDs. Since this vdW JFET would have low-density traps at the vdW interface unlike 2D TMD-based metal insulator semiconductor field effect transistors (MISFETs), little hysteresis of 0.0–0.1 V and best subthreshold swing of ~100 mV/dec were achieved. Easy saturation was observed either from n-channel or p-channel JFET as another advantage over 2D MISFETs, exhibiting early pinch-off at ~1 V. Operational gate voltage for threshold was near 0 V and our highest mobility reaches to ~>500 cm2/V·s for n-channel JFET with MoS2 channel. For 1 V JFET operation, our best ON/OFF current ratio was observed to be ~104.
Simultaneous determination of legacy and emerging per- and polyfluoroalkyl substances in fish by QuEChERS coupled with ultrahigh performance liquid chromatography tandem mass spectrometry
Authors: Gao Yan , Zhang Qinghe , Li Xiaomin , Li Xiuqin , Li Hongmei
Published: October 2018

In this study, a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was developed for simultaneous determination of 30 legacy and emerging per- and polyfluoroalkyl substances (PFASs) in fish by UHPLC-MS/MS.
A high-density collagen xerogel thread prevents the progression of peritoneal fibrosis
Authors: Aoki Shigehisa , Takezawa Toshiaki , Nagase Kei , Oshikata-Mitazaki Ayumi , Morito Sayuri , Sakumoto Takehisa , Masuda Masanori , Yamamoto-Rikitake Mihoko , Akutagawa Takashi , Toda Shuji
Published: October 2018

An inserted high-density collagen xerogel thread prevents pathological fibrosis through the inhibition of inflammation and stromal cell proliferation in the peritoneum.
Synergistic effect of bimetallic PdAu nanocrystals on oxidative alkyne homocoupling
Authors: Chen Zheng , Shen Rongan , Chen Chen , Li Jinpeng , Li Yadong
Published: October 2018

A bimetallic Pd–Au heterogeneous catalyst with synergistic effects is developed to efficiently catalyze oxidative homocoupling of terminal alkynes.
Diversity of methyl group dynamics in felodipine: a DFT supported NMR and QENS study
Authors: Pajzderska Aleksandra , Drużbicki Kacper , Gonzalez Miguel Angel , Jenczyk Jacek , Mielcarek Jadwiga , Wąsicki Jan
Published: October 2018

Computationally-supported NMR and neutron scattering experiments were combined to provide new insights into the structure–dynamics relationship in the most stable polymorph of felodipine.
Deep blue emitting Cu(i) tripod complexes. Design of high quantum yield materials showing TADF-assisted phosphorescence
Authors: Schinabeck Alexander , Rau Nicholas , Klein Marius , Sundermeyer Jörg , Yersin Hartmut
Published: October 2018

Triplet and singlet harvesting in combination with enhancing the emitter rigidity leads to a landmark value of the photoluminescence quantum yield for dissolved Cu(i) complexes.
Effect of traditional and modern culinary processing, bioaccessibility, biosafety and bioavailability of eritadenine, a hypocholesterolemic compound from edible mushrooms
Authors: Morales Diego , Tabernero María , Largo Carlota , Polo Gonzalo , Piris Adriana Jiménez , Soler-Rivas Cristina
Published: October 2018

Eritadenine enriched extracts from shiitake might be used in functional foods since they are safe, bioavailable and hypocholesterolemic in rats.
Thin film piezoelectrics for bulk acoustic wave (BAW) acoustophoresis
Authors: Reichert Peter , Deshmukh Dhananjay , Lebovitz Lukas , Dual Jürg
Published: October 2018

Design, fabrication and characterization of thin film piezoelectric devices for bulk acoustic wave acoustophoresis of micrometer-sized particles.
Simultaneous printing and deformation of microsystems via two-photon lithography and holographic optical tweezers
Authors: Chizari Samira , Shaw Lucas A. , Hopkins Jonathan B.
Published: October 2018

Microstructures with embedded strain energy are fabricated by an advanced approach that combines two-photon lithography with holographic optical tweezers.
Two-acceptor one-donor random terpolymers comprising thiophene- and phenyl-capped diketopyrrolopyrrole for organic photovoltaics
Authors: Sambathkumar B. , Varathan E. , Subramanian V. , Somanathan N.
Published: October 2018

A series of random terpolymers comprising two electron deficient phenyl (PDPP) and thiophene (ThDPP)-capped diketopyrrolopyrrole (DPP) in conjugation with the electron-donating thiophene moiety are synthesised using Stille coupling.
An organic phase transmetallation approach for synthesis of hollow Ni–Au nanocomposites with tunable cavity size
Authors: Sardar Debasmita , Ahmed Md Azaharuddin , Bandyopadhyay Sudipta , Ghosalya Manoj Kumar , Bala Tanushree
Published: October 2018

Hydrophobized HAuCl4 entered Ni nanoparticles through the fractures on the surface initiating transmetallation at the centre, yielding hollow Ni–Au composites.
Synthesis and photovoltaic properties of a non-fullerene acceptor with F-phenylalkoxy as a side chain
Authors: Luo Mei , Zhang Zhenzhen , Feng Liuliu , Peng Hongjian , Jiang Lihui , Xu Shutao , Li Hang , Cai Fangfang , Li Yongfang , Zou Yingping
Published: October 2018

A new acceptor–donor–acceptor (A–D–A) non-fullerene acceptor (ITIC-FOR) was synthesized and applied in non-fullerene solar cells with a PCE of up to 7.33%.
Synthesis, characterization and oxidizing strength of a nano-structured hypervalent iodine(v) compound: iodylbenzene nanofibers
Authors: Jafari motlagh Reza , Zakavi Saeed
Published: October 2018

In this study, disproportionation of freshly synthesized iodosylbenzene in boiling distilled water in the presence of triethylene glycol monomethyl ether was used to prepare ribbon-like iodylbenzene nanostructures with a wide length distribution (250 nm up to several microns) and a width in the range of 100–200 nm.
Broadband polarization-insensitive saturable absorption of Fe2O3 nanoparticles
Authors: Mao Dong , Cui Xiaoqi , He Zhiwen , Lu Hua , Zhang Wending , Wang Lei , Zhuang Qiang , Hua Shijia , Mei Ting , Zhao Jianlin
Published: October 2018

The broadband polarization-insensitive saturable absorption of Fe2O3 nanoparticles has been demonstrated for generating Q-switched cylindrical vector beams.
Azobenzene-based small molecular photoswitches for protein modulation
Authors: Zhu Mingyan , Zhou Huchen
Published: October 2018

This review highlights the design strategies of azobenzene photoswitches as well as their applications in the manipulation of biological systems.
A synthetic study toward the core structure of (−)-apicularen A
Authors: Pradhan Tapas R. , Mohapatra Debendra K.
Published: October 2018

A concise synthetic strategy towards the core structure of (−)-apicularen A has been described in an 11-step synthetic sequence from a known intermediate.
Polyampholytic graft copolymers based on polydehydroalanine (PDha) – synthesis, solution behavior and application as dispersants for carbon nanotubes
Authors: Max J. B. , Pergushov D. V. , Sigolaeva L. V. , Schacher F. H.
Published: October 2018

We herein introduce a versatile platform of graft copolymers featuring a polyampholytic backbone and side chains of varying length and polarity using post-polymerization modification of polydehydroalanine (PDha).
Hybrid-silica nanoparticles as a delivery system of the natural biocide carvacrol
Authors: Sokolik Chana G. , Lellouche Jean-Paul
Published: October 2018

The authors fabricated hybrid-silica NPs incorporating the natural antibiotic carvacrol from essential oils covalently with an enzymatically cleavable bond. They are a safe, on-demand antibacterial agent.
Construction of flower-like MoS2/Fe3O4/rGO composite with enhanced photo-Fenton like catalyst performance
Authors: Mu Dongzhao , Chen Zhe , Shi Hongfei , Tan Naidi
Published: October 2018

Flower-like MoS2/Fe3O4/rGO composites have been constructed, which exhibit highly efficient visible-light photocatalytic performance for removing of RhB in the presence of H2O2.
Preparation of superhydrophobic surfaces with micro/nano alumina molds
Authors: Yanagishita Takashi , Murakoshi Kaito , Kondo Toshiaki , Masuda Hideki
Published: October 2018

Superhydrophobic surface with hierarchical structures prepared by nanoimprinting using anodic porous alumina molds.
Potential solution-induced HfAlO dielectrics and their applications in low-voltage-operating transistors and high-gain inverters
Authors: He Gang , Li Wendong , Sun Zhaoqi , Zhang Miao , Chen Xiaoshuang
Published: October 2018

Recently, much attention has been paid to the investigation of solution-driven oxides for application in thin film transistors (TFTs).
Assembly of heteropoly acid into localized porous structures for in situ preparation of silver and polypyrrole nanoparticles
Authors: Liang Jing , Yu Lei , Zhang Jiangyong , Zhao Shixiong , Zhang Jiejing , Zhang Jianfeng
Published: October 2018

An ordered heteropoly acid patterned porous structure is prepared which can be applied to the preparation of silver and polypyrrole nanoparticles.
Photoredox-mediated remote C(sp3)–H heteroarylation of free alcohols
Authors: Li Guo-Xing , Hu Xiafei , He Gang , Chen Gong
Published: October 2018

We report an efficient and economical method for remote δ C(sp3)–H heteroarylation of free aliphatic alcohols using a hypervalent iodine PFBI-OH oxidant under photoredox catalysis.
Tuneable shape-memory properties of composites based on nanoparticulated plant biomass, lignin, and poly(ethylene carbonate)
Authors: Shikinaka Kazuhiro , Funatsu Yudai , Kubota Yuki , Tominaga Yoichi , Nakamura Masaya , Navarro Ronard R. , Otsuka Yuichiro
Published: October 2018

A shape-memory polymer consisting of lignin and poly(ethylene carbonate) was obtained only by kneading without any toxic reagents.
Simultaneous regulation of electrical and thermal transport properties in MnTe chalcogenides via the incorporation of p-type Sb2Te3
Authors: Basit Abdul , Yang Junyou , Jiang Qinghui , Xin Jiwu , Li Xin , Li Sihui , Li Suwei , Long Qiang
Published: October 2018

The thermoelectric performance of MnTe has been enhanced with the addition of Sb2Te3, which improves the ZT ∼77% at 873 K in 1.5 at% Sb2Te3 added MnTe sample.
Design and fabrication of nanoporous adsorbents for the removal of aromatic sulfur compounds
Authors: Tan Peng , Jiang Yao , Sun Lin-Bing , Liu Xiao-Qin , AlBahily Khalid , Ravon Ugo , Vinu Ajayan
Published: October 2018

Traditional and recently emerged nanoporous adsorbents for deep desulfurization of liquid hydrocarbon fuels are summarized.
Low-temperature-processed inorganic perovskite solar cells via solvent engineering with enhanced mass transport
Authors: Zai Huachao , Zhang Deliang , Li Liang , Zhu Cheng , Ma Sai , Zhao Yizhou , Zhao Zhiguo , Chen Changfeng , Zhou Huanping , Li Yujing , Chen Qi
Published: October 2018

Highly efficient and stable low-temperature-processed inorganic perovskite solar cells via solvent engineering with enhanced mass transport.
Arsenite-induced apoptosis can be attenuatedviadepletion of mTOR activity to restore autophagy
Authors: Wu Chien-Wei , Lin Pei-Jung , Tsai Jia-Shiuan , Lin Chih-Ying , Lin Lih-Yuan
Published: October 2018

Arsenic and its compounds are toxic environmental pollutants and known carcinogens.
A gradient system with a wiggly energy and relaxed EDP-convergence
Authors: Dondl Patrick , Frenzel Thomas , Mielke Alexander
Published: October 2018

For gradient systems depending on a microstructure, it is desirable to derive a macroscopic gradient structure describing the effective behavior of the microscopic scale on the macroscopic evolution. We introduce a notion of evolutionary Gamma-convergence that relates the microscopic energy and the microscopic dissipation potential with their macroscopic limits via Gamma-convergence. This new notion generalizes the concept of EDP-convergence, which was introduced in [26], and is now called relaxed EDP-convergence. Both notions are based on De Giorgi’s energy-dissipation principle (EDP), however the special structure of the dissipation functional in terms of the primal and dual dissipation potential is, in general, not preserved under Gamma-convergence. By using suitable tiltings we study the kinetic relation directly and, thus, are able to derive a unique macroscopic dissipation potential. The wiggly-energy model of Abeyaratne-Chu-James (1996) serves as a prototypical example where this nontrivial limit passage can be fully analyzed.
Conférence Coulomb prononcée le 13 juin 2018 : « Parois de soutènement ancrées ou butonnées : l’apport des retours d’expérience organisés »
Authors: Kastner Richard
Published: October 2018

Cet article présente les résultats d’instrumentations et de retours d’expérience effectués sur des parois de soutènements ancrées ou butonnées, en milieu urbanisé. L’objectif de ces suivis était d’observer et de comprendre le comportement de ces ouvrages, leur interaction avec le sol environnant, et d’obtenir des données permettant d’évaluer de manière critique les différentes approches de dimensionnement. Les retours d’expérience ainsi effectués sur des tranchées couvertes et des stations des métros de Lyon et de Toulouse, complétés par une campagne sur modèle réduit, ont mis en évidence les interactions entre le terrain et ces ouvrages, et montré l’importance des effets de voûte dans la sollicitation des parois de soutènement, notamment lorsque les appuis sont passifs. Ils ont permis de cerner le domaine d’utilisation et les limites des approches de dimensionnement reposant sur l’hypothèse du coefficient de réaction, toujours largement utilisée. Ils confirment l’intérêt, pour ces ouvrages, des approches de type éléments finis tout en soulignant la nécessité d’adopter un modèle de sol capable de décrire les principaux comportements mis en jeu. Enfin, les rétro analyses ont permis de préciser les propriétés des terrains à l’échelle de ces ouvrages, en vue d’un dimensionnement plus rigoureux.
Method of building dynamic relations, estimating product and grinding circle shape deviations
Authors: Roshchupkin Stanislav , Kharchenko Alexander
Published: October 2018

The article deals with the method of constructing dynamic relations in the synthesis of automatic control systems for finishing machining processes, including smooth and fine grinding. A method is developed of estimating workpiece shape and grinding wheel deviations when external disturbances impact the object. The application of the proposed approach is useful while estimating non-measurable parameters, which allows to reduce influence of the measurement noises and noises associated with the computational procedures of the corresponding estimation.
The mechanism of wearing of the hard alloy tool under ultrasonic reinforcing finishing treatment
Authors: Gileta Viktor , Beznedelnyy Anatoly
Published: October 2018

The working capacity of indenters prepared from hard alloy VK8 under conditions of reinforcing finishing treatment by ultrasonic tools was investigated. It was found that under normal treatment conditions, normal wear of the hard alloy takes place. An electron microscopic study of the morphology of the surface of the wear area and its state after the etching of cobalt (Co) using replicas was performed. X-ray microanalysis of the wear area was performed. No obvious traces of adhesive, diffusion, abrasive wear were detected. It was shown that the deterioration of the hard alloy tool VK8 mainly occurs as a result of fatigue failure, which leads in the investigated speed range of the part 10...120 m/min to the precipitation of individual carbide grains and whole groups of them. The non-linear nature of the wear-velocity curve is due to allotropic transformations of cobalt. It was found that at cobalt speeds of 10...50 m/min, the first allotropic transformation from the initial β-Co state to α-Co occurs, and then the second partial allotropic conversion of α-Co to β-Co occurs at a velocity of more than 50 m/min. The presence of a β-Co phase, which is more brittle, leads to an intensification of wear. The WC-WC boundaries and the deformation of WC carbides are not responsible for the formation of the wear surface microrelief and the integral wear of the carbide tool.
Possible mechanisms of electrochemical processing activation ARMCO-iron
Authors: Rakhimyanov Konstantin , Gaar Nadezhda , Loktionov Aleksandr
Published: October 2018

The peculiarities of the electrochemical dissolving of ARMCO-iron in the 15% water solution of the sodium chloride during electrochemical dissolving the material and under the impact of laser radiation with a wavelength of 1.06 micrometer are considered. The investigations were conducted at a special installation by the potentiodynamic method. It is established that the material passivation at a potential range of 1.26 – 2.6 V is observed during electrochemical dissolving the material in the stationary conditions. The increase in the value of the current density by 45 times occurs in introducing the laser radiation in the process of anode dissolving and the passivation areas are not observed. The dissolution process takes place actively in the whole range of potentials from 0 to 5 V. It is shown that the main mechanisms of laser activation of electrochemical dissolving the materials is the depassivation of the anode surface and the acceleration of electrochemical reactions. It is determined that the maximum current density is achieved during laser-electrochemical processing of ARMCO-iron at a pulse repetition frequency of laser radiation equal to 3 kHz.
Anodic behavior of amorphous and nanocrystal alloys during the electrochemical processing
Authors: Rakhimyanov Konstantin , Ivanova Maria , Vasilevskaya Svetlana
Published: October 2018

Magnetically soft alloys possessing unique characteristics, which determine corrosive, magnetic and other properties, are used as a construction material in the amorphous structural state. The amorphous alloys have a high hardness and unusual fragility along with unique magnetic properties. Due to this fact, there are some limitations in using these alloys as construction materials, which is related to the problems of their processing. Applying traditional methods of mechanical processing is impossible. Thus, the electro-diamond grinding based on the combined action of anodic dissolving and mechanical cutting by the diamond grains is used for processing the open surfaces, for instance, for grooving in the machine stator made of 5BDSR alloy. However, the use of the electrochemical size processing by the cathode-tool based on localizing the anodic dissolving of the machined material is considered to be perspective for processing geometrically complex cavities or holes with a small diameter. To develop the technology of surface forming in details made of 5BDSR and 82K3HSR alloys, the analysis of their anodic behavior during the electrochemical processing was conducted. The reasons for the anode surface passivation during the electrochemical processing of the investigated alloys were found both in amorphous and in amorpho-nanocrystal structural state in 10% electrolytes NaNO3, Na2SO4 and NaCl.
Prospects of combining electro-erosive and electrochemical processes in forming the holes of a small diameter in difficult-to-process materials
Authors: Rakhimyanov Kharis , Vasilevskaya Svetlana
Published: October 2018

Implementation of modern methods in forming the surfaces of a small geometrical size in materials difficult to process allows putting into practice new technical solutions to designing different objects. Most technologies are based on using electro-physical methods of processing. The combination of processes with various physical nature in one method is considered to be perspective. So, the use of erosive and electrochemical processing to pierce the holes of small diameter is suggested. It is determined experimentally that the implementation of electro-erosive discharges in the inter-electrode gap during electrochemical piercing of the hole in stainless steel 12H18N10T by a hollow cathode, which is a tool having the external diameter of 0.46 mm, allowed increasing the piercing speed by 3.7 times compared to electrochemical processing. As a result, the hole taper reduced from 4.3° to 2.5° and the accuracy of duplicating the cathode increased. It was assumed that the further increase in the accuracy of forming the holes was possible by using the cathode with an electrically isolated side surface.
Robotic edge machining with abrasive brushes
Authors: Dimov Yuriy , Podashev Dmitriy
Published: October 2018

The article describes application of an industrial robot with an electric spindle for finish machining of parts made from aluminum alloy V95pchT2 and titanium alloy VT-20 using abrasive brushes. Effects of cutting velocity, brush deformation and supply on machining performance (edge size) and surface quality (positioning and roughness) have been identified. Based on the experimental data, mathematical dependencies have been developed.
Development of a virtual management system for the cutting process using neural networks
Authors: Ovsyanikova Irina , Tarapanov Aleksandr
Published: October 2018

The article deals with the problems of choosing the neural network configuration for blade processing control. The analysis of input parameters is carried o7ut and the virtual representation of cutting’s technological process is simulated. A mathematical control model that allows to mutually transform processes depending on the control criteria is proposed. The configuration of the neural network, that allows to provide the most productive and stable operation with insufficient and contra dictionary input parameters is established.
Pulse micro-surfacing as nonconventional method within the comprehensive technology of the gas-turbine engine recovery
Authors: Tarasenko Yuriy , Krivina Ludmila , Kirikov Sergei
Published: October 2018

The results of the experimental studies on the choice of optimal surfacing material for a pulse micro-surfacing of the details made of monocrystal nickel superalloys are set out. The microstructure, the microhardness, the adhesion strength and the heat-resistant stability of the built-up zones have been analyzed. The results of the research have been introduced within the elaboration of technological process of recovering working capacity and prolongation of a resource of the first step working blades of gas turbines SGT-800 Siemens, having completed their operating life (~23 000 equivalent hours).
Research of kinematics of an actuating group of an anthropomorphic gripper with a common drive
Authors: Bogdanov Alexey , Permyakov Alexander , Zhdanova Yulia
Published: October 2018

Anthropomorphic robots (AR): Robonaut (USA), Asimo (Japan), FEDOR (Russia) are similar to human capabilities in performable actions. Whereby the AR efficiency depends on the anthropomorphic gripper (AG) functionality. The key problems while its developing are restrictions imposed on permissible amount of using motors. One of advanced approaches to developing of the AG with capabilities similar to a human hand is the use of a common drive wisawe3dsth a special motion transfer system (MTS). Due to including functioning connections into the MTS construction the variability of a schematic structure is provided and the kinematic dependence of output links motion is excluded, thus their sequence motion is provided. The inverse kinematic problem was solved for the developed MTS version. Analytical dependences joining the MTS parameters, rotational angles of actuating group links with a rotational angle of an output link drive are obtained. Performed researches are sufficient for the AG power analysis. Implementability of gripper links rotational angles similar to the phalanges rotation, when using the proposed MTS, is confirmed.
Kinematic error of a harmonic drive
Authors: Lyuminarsky Igor , Lyuminarsky Stanislav
Published: October 2018

The article deals with the causes for kinematic error of harmonic drives. The error was determined theoretically using a mathematical model of a drive accounting elastic interactions of the drive elements. The paper identifies the main cause for the inherent kinematic error of a harmonic drive featuring a cam wave generator: a variation in a flexible gear deformation at rolling of flexible bearing balls. It was established that the highest kinematic error of a drive is significantly lower than the first harmonic of a flexible gear generating error. There is obtained a cam displacement dependence of the highest kinematic error for VZP-80 drive.
Control of the induction soldering on the basis of process temperature indirect measurements
Authors: Tynchenko Vadim S. , Petrenko Vyacheslav E. , Murygin Alexander V.
Published: October 2018

The article suggests the use of indirect measurements to control the process of induction soldering. Based on the equations of thermodynamics, it is proposed a scheme for approximating the temperature values in the solder zone on the basis of information from pyrometric sensors aimed at an area remote from the soldered joint site. A model-algorithmic instrument for indirect temperature measurements in the soldering technological process is developed, the scheme of which is presented in the article. The software of waveguide paths induction soldering control in the form of an already existing system module has been developed, which allows not only to carry out experimental studies on control algorithms, but also to implement a full-scale experiment, the results of which confirm the effectiveness of the proposed approach.
Use of combined methods of treatment to obtain artificial roughness on the parts’ surfaces
Authors: Ryazantsev Alexander , Yukhnevich Sergey
Published: October 2018

Opportinities of combined treatment field of use expanding for obtaining of artificial roughness on the parts’ surfaces are unveiled. The way of assurance of process stability and rise of technological parameters are shown, which allowed to expand the application field of high-efficiency dimensional combined treatment with the use of precision impulse optical fiber laser as a part of laser complex. Such a task is resolved for the first time and its results contribute to creation of items of new generation of equipment, which is relevant for mechanical industry.
Bending deformation analysis of gear hone tooth lateral faces
Authors: Bagaiskov Yuriy
Published: October 2018

Gear hones are used for finish machining of hardened gear tooth lateral faces by the generating method. In service, due to penetration of abrasive grains into metal, wear and running-in of the tool material, especially in the case of elastic binding agents, the tooth contact takes place not in a point, but in an ellipse area. The total bending deformation of a hone tooth in the contact point is a sum of the fixed tooth bending deformation and the deformation, characterizing the tooth root travel in a hone rim. The calculations make it evident that hone tooth bending deformation value depends on the contact point vertical position; it drops by a factor of 400 – 500 from the lower contact point to the top. Besides, deformation increases by a factor of 60 with decrease of the elasticity modulus. The rim part adjacent to a tooth is also considered during analysis of the second component of the total tooth bending deformation, characterizing the tooth root elastic strain. With the tooth height increase, this deformation value increases by a factor of 4 – 20 and significantly (by an order of magnitude) increases with the elasticity modulus drop. Bending deformation analysis results of gear hone teeth are applied for studying their operation capabilities, as well as development of geometry and compound specifications.
Possibilities and limitations of titanium alloy additive manufacturing
Authors: Agapovichev Anton , Sotov Anton , Kokareva Victoria , Smelov Vitaly
Published: October 2018

This paper reviews the state-of-the-art of an important, rapidly emerging, additive manufacturing technology. Paper deals with the literature review of the Medical and Aerospace application of Additive Manufacturing from Ti alloys and its benefits and limitations. The study also demonstrate and compare the mechanical properties of Ti6Al4V samples produced by different technologies.