bluuebunny/crossref_metadata_2025 huggingface dataset:
Navigating the DNA encoded libraries chemical space
Authors: Martín Alfredo , Nicolaou Christos A. , Toledo Miguel A.
Published: September 2020

DNA-encoded library (DEL) technology is a novel ligand identification strategy that allows the synthesis and screening of unprecedented chemical diversity more efficiently than conventional methods. However, no reports have been published to systematically study how to increase the diversity and improve the molecular property space that can be covered with DEL. This report describes the development and application of eDESIGNER, an algorithm that comprehensively generates all possible library designs, enumerates and profiles samples from each library and evaluates them to select the libraries to be synthesized. This tool utilizes suitable on-DNA chemistries and available building blocks to design and identify libraries with a pre-defined molecular weight distribution and maximal diversity compared with compound collections from other sources.
Energy relaxation pathways between light-matter states revealed by coherent two-dimensional spectroscopy
Authors: Mewes Lars , Wang Mao , Ingle Rebecca A. , Börjesson Karl , Chergui Majed
Published: September 2020

Coupling matter excitations to electromagnetic modes inside nano-scale optical resonators leads to the formation of hybrid light-matter states, so-called polaritons, allowing the controlled manipulation of material properties. Here, we investigate the photo-induced dynamics of a prototypical strongly-coupled molecular exciton-microcavity system using broadband two-dimensional Fourier transform spectroscopy and unravel the mechanistic details of its ultrafast photo-induced dynamics. We find evidence for a direct energy relaxation pathway from the upper to the lower polariton state that initially bypasses the excitonic manifold of states, which is often assumed to act as an intermediate energy reservoir, under certain experimental conditions. This observation provides new insight into polariton photophysics and could potentially aid the development of applications that rely on controlling the energy relaxation mechanism, such as in solar energy harvesting, manipulating chemical reactivity, the creation of Bose–Einstein condensates and quantum computing.
Lactose quantification in bovine milk by nuclear magnetic resonance without deuterated solvent (No-D qNMR)
Authors: Alves da Cunha Danyelle , Valim Thays Cardoso , Filgueiras Paulo Roberto , Lacerda Junior Valdemar , Neto Alvaro Cunha
Published: September 2020

Validation of a method to quantify low lactose content in commercial lactose-free milk by 1H NMR analysis.
Detecting differential protein abundance by combining peptide levelP-values
Authors: Killinger Bryan J. , Petyuk Vladislav A. , Wright Aaron T.
Published: September 2020

Application of empirical Brown's method to peptide intensities from comparative LC-MS proteomics experiments accurately detects differentially abundant proteins.
The phase-change evolution from surface to bulk of MnO anodes upon cycling
Authors: Chang Liang , Liu Dongqi , Zhou Tong , Hu Min , Wang Yuchen , Ge Shangmeng , He Jia , Li Chao , An Cuihua
Published: September 2020

The phase transformation of MnO is revealed, in which the Mn2+ was found to initially oxidize to Mn4+ and subsequently reduce to a mixed valence of Mn2+ and Mn3+, correlating with the tendency of their discharge capacity variation upon cycling.
2-Activated 1,3-enynes in enantioselective synthesis
Authors: Bao Xiaoze , Ren Jinhui , Yang Yang , Ye Xinyi , Wang Baomin , Wang Hong
Published: September 2020

2-Activated 1,3-enyne has emerged as a versatile synthetic precursor for the construction of valuable enantioenriched molecules.
Salt bridges govern the structural heterogeneity of heme protein interactions and porphyrin networks: microperoxidase-11
Authors: Porter J. , Dit Fouque K. Jeanne , Miksovska J. , Fernandez-Lima F.
Published: September 2020

In this work, a proteolytic digest of cytochrome c (microperoxidase 11, MP-11) was used as a model to study the structural aspects of heme protein interactions and porphyrin networks.
Treatment of Staphylococcus aureus skin infection in vivo using rifampicin loaded lipid nanoparticles
Authors: Walduck Anna , Sangwan Parveen , Vo Quynh Anh , Ratcliffe Julian , White Jacinta , Muir Benjamin W. , Tran Nhiem
Published: September 2020

We report a novel cubosome formulation that is effective at killing Staphylococcus aureus in vitro.
Dielectrophoretic separation of platelet cells in a microfluidic channel and optimization with fuzzy logic
Authors: Ertugrul Ishak , Ulkir Osman
Published: September 2020

It is the aim to develop optimization techniques to separate platelets from Red Blood Cells (RBCs) after designing and analyzing a microfluidic chip in this study.
Nematic colloids at liquid crystal–air interfaces via photopolymerization
Authors: Wei Xiaoshuang , Sbalbi Nicholas , Bradley Laura C.
Published: September 2020

Simultaneous synthesis and assembly of nematic colloids at 5CB–air interfaces via photopolymerization.
Identification and seasonality of rhinovirus and respiratory syncytial virus in asthmatic children in tropical climate
Authors: Lopes Giselmo Pinheiro , Amorim Ítalo Patrick Souza , Melo Bruna de Oliveira de , Maramaldo Carlos Eduardo Campos , Bomfim Maria Rosa Quaresma , Lima Neto Lídio Gonçalves , Alves Matheus Silva , Silva Fabrício Brito , Soeiro-Pereira Paulo Vítor , Falcai Angela
Published: September 2020

Introduction: Asthma is a disease that has been associated with the presence of different genetic and socio-environmental factors.

Objective: To identify and evaluate the seasonality of respiratory syncytial virus (RSV) and human rhinovirus (RV) in asthmatic children and adolescents in tropical climate, as well as to assess the socioeconomic and environmental factors involved.

Methods: The study was conducted in a referral hospital, where a total of 151 children were recruited with a respiratory infection. The International Study of Asthma and Allergies in Childhood (ISAAC) protocol and a questionnaire were applied, and a skin prick test was performed. The nasal swab was collected to detect RV and RSV through molecular assay. National Meteorological Institute (INMET) database was the source of climatic information.

Results: The socio-environmental characterization of asthmatic children showed the family history of allergy, disturbed sleep at night, dry cough, allergic rhinitis, individuals sensitized to at least one mite. We identified RV in 75% of children with asthma and 66.7% of RSV in children with asthma. There was an association between the presence of RV and the dry season whereas the presence of the RSV was associated with the rainy season. Contributing to these results, a negative correlation was observed between the RSV and the wind speed and the maximum temperature (T. Max) and a positive correlation with precipitation.

Conclusions: The results suggest a high prevalence of RV and RSV in asthmatic children and the seasonality of these viruses were present in different climatic periods. This has significant implications for understanding short- and long-term clinical complications in asthmatic patients.
Preschool Speech Intelligibility and 8-Year Literacy: A Moderated Mediation Analysis
Authors: Jin Fufen , Schjølberg Synnve , Eadie Patricia , Nes Ragnhild Bang , Røysamb Espen
Published: September 2020

Purpose

The aims of this study were (a) to examine the relationship between speech intelligibility at the age of 5 years and literacy skills at the age of 8 years, (b) to explore the possible mediating or moderating role of broader language skills at 5 years in the relationship of interest, and (c) to assess whether the potential risk factors (child gender; maternal education levels; and family history of speech, language, reading, and writing difficulties) influence the relationship between speech intelligibility and literacy in terms of moderated mediation effects.

Method

We used mother-reported questionnaire data on 16,184 children participating in the population-based, prospective Norwegian Mother, Father and Child Cohort Study as well as conducted linear regression analyses using the PROCESS macro in SPSS. In addition, logistic regression was conducted to make predictions about risk.

Results

The association between speech intelligibility at 5 years and literacy skills at 8 years was statistically significant (β = .168,
p
< .001). Children with speech problems at 5 years had a risk ratio of 2.38 (95% CI [2.10, 2.70]) and an odds ratio of 2.74 (95% CI [2.35, 3.19]), as compared to children without such problems. Broader language skills at 5 years partially mediated the relationship between speech intelligibility at 5 years and literacy at 8 years, and the effect of language skills appeared to be moderated by child gender, a family history of language difficulties, a family history of reading difficulties, and maternal education.

Conclusions

Severity of speech problems indexed by parent-reported speech intelligibility in preschool predicted school-age literacy problems. Broader language skills are a crucial mediating mechanism through which these problems are linked, and the mediated relationship is amplified by female gender, low maternal education, family history of language difficulties, and family history of reading difficulties. The findings call for increased use of a multiple-risk model when planning early interventions in children with unclear speech.
Cellular automata models for signalised and unsignalised intersections with special attention to mixed traffic flow: a review
Authors: Singh Mohit Kumar , Ramachandra Rao Kalaga
Published: September 2020

Present study reviews simulation models available for signalised and unsignalised intersections using cellular automata (CA). CA models are discrete dynamic systems, through which it is possible to model traffic behaviour with ease and simplicity. Thus, CA was chosen for the study. Driver, seepage behaviour and type of traffic (homogeneous/heterogeneous) affect the capacity and safety of the intersections. These models can be either with open boundary (with continuous deletion and generation of vehicles) or closed/periodic boundary (with a fixed number of vehicles). The proposed study also investigates about the boundary conditions of simulation models as these change the results of simulations. Further, frequent acceleration/deceleration activity at the intersection causes more emissions. It was found that most of the traffic simulation models developed for intersections lack in modelling interaction between vehicles, seepage, driver behaviour and emission behaviour etc. Very few studies were found to model the emission behaviour with CA. Present study chronologically lists studies with methods adopted, advancements in those methods, traffic behaviours taken into consideration and missing gaps between studies. The composition and interaction of five different modes such as cars, buses, trucks, motorised three‐wheelers and motorised two‐wheelers were considered as mixed traffic. A new methodology is suggested based on this review.
Influence of the multi-component electrical feed of air-core industrial reactors on their sound radiation
Authors: Gning Paul , Lanfranchi Vincent , Dauchez Nicolas
Published: September 2020

High voltage devices such as dry-type air-core reactors are subjected to environmental noise standards. Their excitation is due to Lorentz forces originated from the magnetic field, created by the coil itself, combined with the feed current. The objective of this paper is to show how spectral components present in the supply current of industrial dry-type air-core reactors is likely to produce a significant acoustic radiation. First, the multi-component distribution of the Lorentz forces is established. Then, the multi-physics computation process allowing to determine the acoustic pressure induced by each force component is presented. Finally, two industrial reactors are studied: a single and a multi-layer coil. It is pointed out that significant acoustic emergence can be induced by the interaction between small current spectral components with the fundamental or with each other.
Cancerous lesions in the vicinity of dental implants: a systematic review
Authors: Salgado-Peralvo Angel-Orión , Serrano-Sánchez Víctor , Vaello-Checa Iris , Helm Alexandra , Mateos-Moreno María-Victoria , Salgado-Velázquez Alberto
Published: September 2020

Introduction: The massive diffusion of dental implant treatments in the last decades leads to the appearance of complications, most of them inflammatory, although important complications have been described as malignant lesions in the vicinity of dental implants. The objective of this article is to describe the cases described in the literature of oral squamous cell carcinoma (OSCC) or clinical variants and metastases, in the vicinity of dental implants and to analyze the possible etiological agents involved. Material and methods: The criteria used were those described in the PRISMA® Declaration for performing systematic reviews. An electronic search was performed on MEDLINE (via PubMed) using the terms MeSH: “dental implants” AND “squamous cell carcinoma” OR “dental implant complications” AND “squamous cell carcinoma”. Results: Thirty-eight articles describing a total of 76 cases of OSCC or clinical variants, as well as metastasis in the vicinity of dental implants, were included. Conclusions: It is not possible to establish a cause-effect relationship between dental implants and the development of OSCC. Its clinical appearance can be confused with periimplantitis, so that, in cases of sudden onset, which do not respond to conventional treatment and/or have associated alterations in sensitivity, a biopsy should be performed.
Numerical analysis of local heat flux and thin-slab solidification in a CSP funnel-type mold with electromagnetic braking
Authors: Liu Heping , Zhang Jianjun , Tao Hongbiao , Zhang Hui
Published: September 2020

In this article, based on the actual monitored temperature data from mold copper plate with a dense thermocouple layout and the measured magnetic flux density values in a CSP thin-slab mold, the local heat flux and thin-slab solidification features in the funnel-type mold with electromagnetic braking are analyzed. The differences of local heat flux, fluid flow and solidified shell growth features between two steel grades of Q235B with carbon content of 0.19%C and DC01 of 0.03%C under varying operation conditions are discussed. The results show the maximum transverse local heat flux is near the meniscus region of over 0.3 m away from the center of the wide face, which corresponds to the upper flow circulation and the large turbulent kinetic energy in a CSP funnel-type mold. The increased slab width and low casting speed can reduce the fluctuation of the transverse local heat flux near the meniscus. There is a decreased transverse local heat flux in the center of the wide face after the solidified shell is pulled through the transition zone from the funnel-curve to the parallel-cure zone. In order to achieve similar metallurgical effects, the braking strength should increase with the increase of casting speed and slab width. Using the strong EMBr field in a lower casting speed might reverse the desired effects. There exist some differences of solidified shell thinning features for different steel grades in the range of the funnel opening region under the measured operating conditions, which may affect the optimization of the casting process in a CSP caster.
La spectrométrie de masse par accélérateur
Authors: Bourlés Didier L. , Simon Quentin , Thouveny Nicolas
Published: September 2020

L’étude des nucléides cosmogéniques et leur application aux géosciences débutent dans les années 1980, avec le développement de spectromètres de masse par accélération dédiés. Depuis 2007, grâce à l’instrument national ASTER (Accélérateur pour les Sciences de la Terre, Environnement, Risques) du CEREGE, des progrès majeurs ont été réalisés. Ils ont permis la quantification jusqu’alors impossible de nombreux processus géophysiques.

Parmi ces avancées, la restitution fidèle du champ magnétique terrestre pendant le dernier million d’années a été rendu possible par les mesures de concentration du béryllium-10 (10Be) atmosphérique.
Congélation d’émulsions : de la mayonnaise à la métallurgie
Authors: Deville Sylvain , Monteux Cécile
Published: September 2020

Si congeler de la mayonnaise n’est pas recommandé, cela pourrait toutefois nous aider à comprendre la fabrication d’alliages métalliques, la cryopréservation des cellules ou encore la congélation des sols en hiver.

Nous nous intéressons ici au cas des gouttes d’huile dans une émulsion, observées par microscopie confocale au cours de la congélation. De nombreux phénomènes physiques (transport, diffusion, solidification, instabilités) prennent place lors de ce processus, offrant aux physicien.ne.s un problème inédit aux multiples ramifications. Ces études pourraient améliorer notre compréhension de plusieurs phénomènes de solidification, naturels comme technologiques.
Fluid M/M/1 catastrophic queue in a random environment
Authors: Ammar Sherif I.
Published: September 2020

Our main objective in this study is to investigate the stationary behavior of a fluid catastrophic queue of M/M/1 in a random multi-phase environment. Occasionally, a queueing system experiences a catastrophic failure causing a loss of all current jobs. The system then goes into a process of repair. As soon as the system is repaired, it moves with probability qi ≥ 0 to phase i. In this study, the distribution of the buffer content is determined using the probability generating function. In addition, some numerical results are provided to illustrate the effect of various parameters on the distribution of the buffer content.
Propagation of New Chestnut Rootstocks with Improved Resistance to Phytophthora cinnamomi – New Cast Rootstocks
Authors: Fernandes Patrícia , Amaral Andreia , Colavolpe Belén , Balonas Daniela , Serra Maria , Pereira António , Costa Rita Lourenço
Published: September 2020

Nowadays there is a great demand for chestnut rootstocks with improved resistance to Phytophthora cinnamomi, the causing agent of ink disease/root rot. The majority of genotypes that are being commercialized and used in the new plantations, were selected from the breeding programs of the XX century. The climate scenarios have been changing throughout the years, therefore the selection of new genotypes, better adapted to the current conditions of soil and climate, together with an effective and expedite production system, are essential to fulfill the needs of the market on better propagation materials. The INIAV’s chestnut breeding program, established in 2006, aims the improvement of resistance of chestnut to biotic stresses. By taking advantage of micropropagation, this program developed a pipeline to produce new hybrid varieties with improved resistance to P. cinnamomi. Micropropagation helps to overcome the recalcitrance that chestnut tissues present to traditional clonal propagation techniques. This work describes the pipeline of production of these hybrids and characterizes the plants from in vitro to ex vitro conditions. The pipeline allows the development of healthy plants capable of robust and continuous growth in ex vitro conditions. Nowadays these hybrids are being multiplied in a large scale production system, to be released to the market in the near future.
Immune Function following Major Spinal Surgery and General Anesthesia
Authors: Relland Lance M. , Hall Mark , Martin David P. , Nateri Jyotsna , Hanson-Huber Lisa , Beebe Allan , Samora Walter , Klamar Jan , Muszynski Jennifer , Tobias Joseph D.
Published: September 2020

There are reported differences in the effects that general anesthetics may have on immune function after minor surgery. To date, there are no prospective trials comparing total intravenous anesthesia (TIVA) with a volatile agent-based technique and its effects on immune function after major spinal surgery in adolescents. Twenty-six adolescents undergoing spinal fusion were randomized to receive TIVA with propofol-remifentanil or a volatile agent-based technique with desflurane-remifentanil. Immune function measures were based on the antigen-presenting and cytokine production capacity, and relative proportions of cell populations. Overall characteristics of the two groups did not differ in terms of perioperative times, hemodynamics, or fluid shifts, but those treated with propofol had lower bispectral index values. Experimental groups had relatively high baseline interleukin-10 values, but both showed a significant inflammatory response with similar changes in their respective immune functions. This included a shift toward a granulocytic predominance; a transient reduction in monocyte markers with significant decrease in antigen-presenting capacity and cytokine production capacity. Anesthetic choice does not appear to differentially impact immune function, but exposure to anesthetics and surgical trauma results in reproducibly measurable suppression of both innate and adaptive immunity in adolescents undergoing posterior spinal fusion. The magnitude of this suppression was modest when compared with pediatric and adult patients with critical illnesses. This study highlighted the need to evaluate immune function in a broader population of surgical patients with higher severity of illness.
Flare of Antiphospholipid Syndrome in the Course of COVID-19
Authors: Maria Alexandre Thibault Jacques , Diaz-Cau Isabelle , Benejean Jean-Marc , Nutz Anaïs , Schiffmann Aurélie , Biron-Andreani Christine , Guilpain Philippe
Published: September 2020

We report the case of a 48-year-old man followed since 2013 for primary antiphospholipid syndrome (APLS) revealed by venous thromboembolism in the presence of antiphospholipid antibodies (APL-Abs, anticardiolipin and anti-β-2-glycoprotein-1), who decompensated in the course of coronavirus disease (COVID-19). Despite efficient anticoagulation, he suffered bilateral adrenal glands hemorrhage and limb arterial ischemia. The tropism of severe acute respiratory syndrome coronavirus-2 for endothelium can lead to microangiopathy and increased risk for thrombosis. If APL-Abs positivity can be an epiphenomenon under inflammatory and prothrombotic conditions, COVID-19 was herein responsible for disseminated thrombosis and a threat of catastrophic APLS, despite efficient anticoagulation.
Robert Edwards and the history of Australian rock art research
Authors: Smith M. A. , Ross J. , Kimber R. G.
Published: September 2020

Working in the 1960s, Robert (Bob) Edwards was a key figure in the development of research into Australian rock art. He was one of the first rock art scholars to attempt a quantitative and comparative survey of rock engravings in south and central Australia. In this paper, we examine the development of his work on rock engravings, the intellectual context for his research, and the problems he addressed. Edwards’ research took place during a decade when rock art research became more systematic, analytical and quantitative. Although Edwards’ research on rock engravings was influential, his subsequent career shows a shift from an antiquarian interest in which he regarded rock art as an archaeological relic of an ancient Australia, to a more humanist perspective, where he began to appreciate that many of the sites that he regarded as ancient were part of a living tradition.
Perinatal androgens organize sex differences in mast cells and attenuate anaphylaxis severity into adulthood
Authors: Mackey Emily , Thelen Kyan M. , Bali Vedrana , Fardisi Mahsa , Trowbridge Madalyn , Jordan Cynthia L. , Moeser Adam J.
Published: September 2020

Significance

Mast cell (MC)-associated disorders exhibit a sex bias, with females at increased risk. While attention has been directed to adult sex hormones as a mechanism for disease risk between the sexes, epidemiological evidence clearly shows that these same sex biases also exist in prepubertal children, thus challenging this concept. Here, we show that perinatal, but not adult gonadal, androgens play a protective role in MC-mediated anaphylaxis severity into adulthood. We propose that perinatal androgens mediate their protective effects via programming of bone marrow MC precursors to exhibit reduced granule histamine and release. These findings shift attention to perinatal life as a critical period for potential interventions to mitigate MC-associated disease risk across the lifespan in males and females.
Disruption of a key ligand-H-bond network drives dissociative properties in vamorolone for Duchenne muscular dystrophy treatment
Authors: Liu Xu , Wang Yashuo , Gutierrez Jennifer S. , Damsker Jesse M. , Nagaraju Kanneboyina , Hoffman Eric P. , Ortlund Eric A.
Published: September 2020

Significance

Corticosteroids that are currently in clinical use bind to the glucocorticoid receptor (GR) to exert antiinflammation effects, yet are associated with undesirable side effects. Vamorolone is a recently developed drug for Duchenne muscular dystrophy; it decreases muscle inflammation and reduces side effects observed in other corticosteroid-based treatments. Our structure studies reveal a crucial GR-ligand hydrogen bond is not possible in vamorolone. An unprecedented allosteric intramolecular network derived from this hydrogen bond modulates GR dynamic motions and coregulator binding. Our work provides insights into how subtle modifications on a drug exploits structural and dynamic properties in the receptor to dissociate downstream side effects from therapeutic benefits.
Global potential, topology, and pattern selection in a noisy stabilized Kuramoto–Sivashinsky equation
Authors: Chen Yong-Cong , Shi Chunxiao , Kosterlitz J. M. , Zhu Xiaomei , Ao Ping
Published: September 2020

Significance

Vortex or pattern formations are caused by nonlinear interactions within a complex system far from equilibrium. They cannot be well described by variational methods based on traditional potential functions. We aim to bridge the gap in this research. A previously developed stochastic decomposition on finite dimensions is extended to continuous nonlinear partial differential equations. Using a noisy stabilized Kuramoto–Sivashinsky equation as a role model, we show that a certain process of pattern selections can be viewed as stochastically driven on a global potential landscape, with a topology of an interconnected network of saddle points. The approach paves a way to further explore nonlinear phenomena under the general umbrella of statistical physics.
Calcium imaging in freely moving mice during electrical stimulation of deep brain structures
Authors: Trevathan James K , Asp Anders J , Nicolai Evan N , Trevathan Jonathan M , Kremer Nicholas A , Kozai Takashi DY , Cheng David , Schachter Mike J , Nassi Jonathan J , Otte Stephani L , Parker Jones G , Lujan J Luis , Ludwig Kip A
Published: September 2020

Objective. After decades of study in humans and animal models, there remains a lack of consensus regarding how the action of electrical stimulation on neuronal and non-neuronal elements—e.g. neuropil, cell bodies, glial cells, etc.—leads to the therapeutic effects of neuromodulation therapies. To further our understanding of neuromodulation therapies, there is a critical need for novel methodological approaches using state-of-the-art neuroscience tools to study neuromodulation therapy in preclinical models of disease. Approach. In this manuscript we outline one such approach combining chronic behaving single-photon microendoscope recordings in a pathological mouse model with electrical stimulation of a common deep brain stimulation (DBS) target. We describe in detail the steps necessary to realize this approach, as well as discuss key considerations for extending this experimental paradigm to other DBS targets for different therapeutic indications. Additionally, we make recommendations from our experience on implementing and validating the required combination of procedures that includes: the induction of a pathological model (6-hydroxy dopamine model of Parkinson’s disease) through an injection procedure, the injection of the viral vector to induce GCaMP expression, the implantation of the gradient refractive index lens and stimulation electrode, and the installation of a baseplate for mounting the microendoscope. We proactively identify unique data analysis confounds occurring due to the combination of electrical stimulation and optical recordings and outline an approach to address these confounds. Main results. In order to validate the technical feasibility of this unique combination of experimental methods, we present data to demonstrate that (1) despite the complex multifaceted surgical procedures, chronic optical recordings of hundreds of cells combined with stimulation is achievable over week long periods (2) this approach enables measurement of differences in DBS evoked neural activity between anesthetized and awake conditions and (3) this combination of techniques can be used to measure electrical stimulation induced changes in neural activity during behavior in a pathological mouse model. Significance. These findings are presented to underscore the feasibility and potential utility of minimally constrained optical recordings to elucidate the mechanisms of DBS therapies in animal models of disease.
Chronic intracochlear electrical stimulation at high charge densities: reducing platinum dissolution
Authors: Shepherd Robert K , Carter Paul M , Enke Ya Lang , Thompson Alex , Flynn Brianna , Trang Ella P , Dalrymple Ashley N , Fallon James B
Published: September 2020

Objective. Cochleae of long-term cochlear implant users have shown evidence of particulate platinum (Pt) corroded from the surface of Pt electrodes. The pathophysiological effect of Pt within the cochlea has not been extensively investigated. We previously evaluated the effects of Pt corrosion at high charge densities and reported negligible pathophysiological impact. The present study extends this work by examining techniques that may reduce Pt corrosion. Approach. Deafened guinea pigs were continuously stimulated for 28 d using biphasic current pulses at extreme charge densities using: (i) electrode shorting; (ii) electrode shorting with capacitive coupling (CC); or (iii) electrode shorting with alternating leading phase (AP). On completion of stimulation, cochleae were examined for corrosion product, tissue response, auditory nerve (AN) survival and trace levels of Pt; and electrodes examined for surface corrosion. Main results. Pt corrosion was evident at ≥200 μC cm−2 phase−1; the amount dependent on charge density (p< 0.01) and charge recovery technique (p < 0.01); reduced corrosion was apparent using CC. Tissue response increased with charge density (p< 0.007); cochleae stimulated at ≥200 μC cm−2 phase−1 exhibited a vigorous response including a focal region of necrosis and macrophages. Notably, tissue response was not dependent on the charge recovery technique (p = 0.56). Despite stimulation at high charge densities resulting in significant levels of Pt corrosion, there was no stimulus induced loss of ANs. Significance. Significant increases in tissue response and Pt corrosion were observed following stimulation at high charge densities. Charge recovery using CC, and to a lesser extent AP, reduced the amount of Pt corrosion but not the tissue response. Stimulation at change densities an order of magnitude higher than those used when programming cochlear implant recipients in the clinic, produced a vigorous tissue response and corrosion products without evidence of neural loss.
Silk fibroin reactive inks for 3D printing crypt-like structures
Authors: Heichel Danielle L , Tumbic Julia A , Boch Marisa E , Ma Anson W K , Burke Kelly A
Published: September 2020

A reactive silk fibroin ink formulation designed for extrusion three-dimensional (3D) printing of protein-based hydrogels at room temperature is reported. This work is motivated by the need to produce protein hydrogels that can be printed into complex shapes with long-term stability using extrusion 3D printing at ambient temperature without the need for the addition of nanocomposites, synthetic polymers, or sacrifical templates. Silk fibroin from the Bombyx mori silkworm was purified and synthesized into reactive inks by enzyme-catalyzed dityrosine bond formation. Rheological and printing studies showed that tailoring the peroxide concentration in the reactive ink enables the silk to be extruded as a filament and printed into hydrogel constructs, supporting successive printed layers without flow of the construct or loss of desired geometry. To enable success of longer-term in vitro studies, 3D printed silk hydrogels were found to display excellent shape retention over time, as evidenced by no change in construct dimensions or topography when maintained for nine weeks in culture medium. Caco-2 (an intestinal epithelial cell line) attachment, proliferation, and tight junction formation on the printed constructs was not found to be affected by the geometry of the constructs tested. Intestinal myofibroblasts encapsulated within reactive silk inks were found to survive shearing during printing and proliferate within the hydrogel constructs. The work here thus provides a suitable route for extrusion 3D printing of protein hydrogel constructs that maintain their shape during printing and culture, and is expected to enable longer-term cellular studies of hydrogel constructs that require complex geometries and/or varying spatial distributions of cells on demand via digital printing.
Experimental Investigation of Under Reamed Pile Subjected to Dynamic Loading in Sandy Soil
Authors: Jebur Maher M. , Ahmed Mahmood D.
Published: September 2020

This paper presents an experimental study between uniform pile and different types of under-reamed pile, single bulb. The under-reamed piles are piles with enlarged bases that are suitable to resist considerable movement of the ground, filed up ground, soft clay, and loose sand which have advantages to increase the soil strength, uplift capacity, and decrease the displacement. In the present study, there are experimental analyze to performance the suitable under-reamed type under sinusoidal load from vertical vibration (motor-oscillator was mounted directly on the pile cap. The main finding of this work is that the pile capacity increases with the ream and that all stress values of soil-structure interaction beneath the pile tip and under-reamed pile bulb due to external load can be founded. The under-reamed pile is made of reinforced concrete and the bulb is located at different positions of the embedded length of the pile. The type of soil used in the present work was loose sand and obtained from Karbala city. The Dynamic time-settlement curve has been obtained from the analysis and it was showed that the reduction in settlement is about 223% in case of using a single bulb from L/2 from pile tip which is the best results in comparison with the uniform pile.
Simulation of Sediment Transport in the Upper Reach of Al-Gharraf River
Authors: Daham Mariam Hadi , Abed Basim Sh.
Published: September 2020

For the past few years, the sediment began to accumulate in Al-Gharraf River which reduces the flow capacity of the River. In the present research, a numerical model was developed using Hec-Ras software, version 5.0.4. to simulate the flow and sediment transport in the upper reach of the river. The hydrological and cross-section data measured by the Ministry of Water Resources, for the reach located between Kut and Hai cities and having a length of 58200 m, was used to perform calibration and verification of the model. Moreover, field sampling of suspended and bed loads was gathered for five months starting from 7/2/2019, and laboratory tests of samples were conducted to be used as input data in the model. Actual flowrates for the year 2018 were used to predict the sediment accumulation in the river, and the results show that the accumulated deposition was ranged between 2.5 cm to 1m, while the erosion depth ranged between -4cm to -2cm. Furthermore, the estimated amounts of sediment discharges were ranged between 70 and 1308 Tones/day. Then four scenarios of flowrates ranged between 100-300 m3/s were used to analyze the possible sedimentation problems and to propose the treatment needed to preserve the morphology of the river The results show that the invert changes of bed depth were ranged between -2 to 9 cm, and the sediment discharge ranged between, 33 to 970 Tones/day. A lining of specified sub-reaches using the concrete or by the grouted riprap was proposed to avoid sedimentation or erosion respectively.
Geoecological Maps of Surface Water Pollution Akmola Region of Kazakhstan Based on Hydrochemical Analyzes
Authors: Raikhan Beisenova , Gulnur Saspugayeva , Aizhan Zhamangara , Makhabbat Ramazanova , Assel Tulebekova
Published: September 2020

Ecological and geographical map that characterizes the introduction and storage in the natural or built environment of physical, chemical, and biological substances in concentrations exceeding the natural (background) values and adversely affecting human health, fauna, flora, and other components of the environment. Maps may reflect contamination of the earth, atmosphere, surface water and groundwater, soils, vegetation, wildlife, and others. They show the sources of pollution (solid waste, air emissions of gases and aerosols, drains and diversion of utilities and others), pollution factors (impact of power plants, transportation, industrial production, animal husbandry, and so on), distribution of natural and man-made pollutants (mechanical, physical, chemical, biological), and others. The levels of pollution often characterize the performance of exceeding the maximum permissible concentration (MPC), the maximum permissible emissions (MPE), and other regulations.
Influence of Modern Processes of Life to The Architecture and Environmental Problems of Urbanization-Cities of Kazakhstan
Authors: Olga Semenyuk , Yelena Khvan , Rahima Chekayeva , Sara Sadykova , Elmira Toibazarova
Published: September 2020

Two directions of research were formed in the theory of architecture: The first is devoted to the issues of architectural design. In the second study the features of the influence of architecture on people. This is a two-way process of human interaction with the environment, it allows you to study in detail in the future, not only the design of an architectural object, but also the state of people interacting with it. On the one hand, a person changes the environment, and on the other reacts to its impact and influence. And this process is an integral part of human life, because the environment affects his emotional state, mental and physiological processes. This underscores the importance of studying the impact of the surrounding urban space on people, regulating the level of comfortable living by analyzing the ecological state of the environment and the quality of buildings being built. Life processes can be formulated as: spiritual, psychological, physiological, mental, bioenergetic, which affect morphogenesis in architecture. When describing an architectural object, we use such criteria as the functionality of the object, the aesthetics of the construction cost, and the modernity of the architectural solution of the building.
Comparative Analysis of the Effect of Different Types of Green Roofs over the Linear Thermal Bridges
Authors: Baciu I-R , Isopescu D N , Taranu N , Lupu M L , Maxineasa S G
Published: September 2020

During recent years, it appears in the background of global discussions the negative impact resulted from the daily humans’ activities. Taking into account the present surface of the built environment and also the fact that this area will significantly increase shortly, it can be considered that using the buildings to develop new solutions like green roofs. The expanding benefits of a green roof emphasize the key role of this structure in the overall thermal performance of buildings and microclimate conditions of indoor spaces. The main objective of the study is to analyse and to interpret the influence of all three main categories of a green roof on the heat flow, in the thermal bridges developed structurally in buildings. The study based on the structural elements of each type of roof, their thermic characteristics and the principal types of thermal bridges will represent a comparison between the thermal impact of a classical terrace roof and that of the extensive, semi-intensive and intensive green roof. In conclusion, the unpredictable results obtained for the analysed thermal parameters let conclude that the green roof solution in all the three forms has an environmental impact, in terms of both sustainability and aesthetics.
Ship resistance and powering prediction of a fishing vessel
Authors: Bilec M , Obreja C D
Published: September 2020

The ship resistance and powering are the most important hydrodynamics performances. In the case of a fishing vessel, both the design speed and trawling speed conditions must be analysed. The ship resistance and powering prediction at design speed were performed in this paper, on the basis of the Holtrop-Mennen method, by using two specific CAD-CAE platforms: AVEVA MARINE (Initial Design module) and PHP (developed in the Naval Architecture Faculty of “Dunărea de Jos” University of Galati). A comparative analysis of the theoretical prediction of the fishing vessel resistance, at full loading condition, with experimental results obtained at the model resistance tests, was presented and the level of accuracy was evaluated. Significant differences were determined between theoretical and experimental results. Also, the trawling condition was analysed. The trawl resistance was estimated on the basis of the typical empirical relations and the simulation software Trawl Vision Software (TVS), developed by AcruxSoft. A considerable increase of the trawl resistance with the ship speed was observed. The trawling speed was calculated on the basis of the brake power necessary for the design speed condition. Taking into account both the ship resistance and trawl resistance estimation, an increase in the accuracy level of the theoretical methods must be performed. Also, numerical and experimental researches must be developed related to the influence of the typical geometry of the trawl, on the resistance performance.
Thermodynamic Cycle Optimization for an Advanced Micro Turbine Power Plant
Authors: Bucur I O , Dumitrescu O , Nicoara R , Vilag J , Dragan V
Published: September 2020

Research interest regarding micro turbines has improved, as their development and manufacturing increased due to the rapid expansion of their application range, from military applications to civil ones. This paper aims to present the methodology used for the ascertainment of the optimal configuration for the functional parameters of a micro jet engine, using a mathematical model for the evaluation of the Brayton cycle as well as a commercial software for its investigation. The DevJet micro jet engine is developed for a thrust of 80 daN with an estimated rotational speed of 40,000 rpm. An analytical model of the Brayton cycle for the evaluation of the main parameters of interest is employed and twelve variants are evaluated, considering values for the pressure ratio ranging from 4 and up to 5, while the maximum temperature range is between 1,050 K and 1,200 K. The optimal variant is selected, and the data is transferred to the commercial software GasTurb in order to generate the diagram of the thermodynamic cycle. The outcome of this research paper represents the input data for the 3D modelling and numerical simulation of the main systems of the micro jet engine.
Acceleration of numerical solution of elastic contact problems by a dual-grid approach
Authors: Cerlinca D , Spinu S
Published: September 2020

Finer meshes employed in the numerical simulation of contact problems provide better accuracy, assuring that the effect of specific features of the initial contact geometry on the stress and displacement field are faithfully captured. Efficient implementation of finer meshes may benefit from a dual-grid scheme, involving a lower level and a desired level. The main idea is to use the lower level for the preparation of a better initial guess for the desired level, obtained by interpolation of results derived on the lower level. A dual-grid scheme involves three steps: (a) solution on the lower level (the coarser grid) with a standard initial guess, (b) interpolation of results into the desired level mesh, providing a more accurate initial approximation for the subsequent step, and (c) the solution of the desired level (the finer mesh) with the improved initial guess. As demonstrated by the conducted numerical simulations, this approach provides important computational advantages, as the solution of the lower mesh is obtained more rapidly than that of the finer mesh, whereas the number of iterations in the upper level is reduced due to the quality of the improved initial guess. The optimal ratio between the lower and the upper levels is investigated through numerical examples and an optimal value is proposed. The proposed dual-grid method should promote faster solutions of the contact problems, and therefore can be implemented in a variety of contact scenarios that rely on the considered algorithm. The improvements should be more beneficial for the contact processes involving the reproduction of the loading path, such as the elastic-plastic or the viscoelastic contact.
The torsional contact of coated bodies
Authors: Cerlinca D , Spinu S
Published: September 2020

This paper advances an algorithm for the simulation of the elastic contact undergoing a constant normal force and an oscillating torsional moment, under the assumption of partial slip. The solution of this type of contact can be achieved with a numerical formulation based on influence coefficients that express the contribution of elementary rectangular patches of uniform surface tractions, normal or tangential, to the displacement field induced in the elastic half-space. Summation of these elementary contributions allows for the calculation of the displacement field for arbitrary distributions of tractions, thus allowing for an iterative problem resolution that can handle arbitrary contact geometry, various frictional regimes and consideration of coated materials. The displacement response of multi-layered bodies is calculated based on the frequency response functions, and a previously advanced technique for calculation of convolution products in the Fourier transform domain is implemented for increased accuracy. The solution of the tangential contact problem is achieved by the treatment of the arising linear system of equations with the conjugate gradient method, which provides superior computational efficiency. The interaction between the normal and the tangential contact tractions is discussed. The influence of the Young modulus ratio between the coating and the substrate on the shear tractions in the partial slip torsional contact is investigated through numerical simulations.