bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of aging tumor microenvironment with drawing implications in predicting the prognosis and immunotherapy response in low-grade gliomas
Authors: Zhou Zijian , Wei JinHong , Jiang Wenbo
Published: March 2022

Aging tumor microenvironment (aging TME) is emerging as a hot spot in cancer research for its significant roles in regulation of tumor progression and tumor immune response. The immune and stromal scores of low-grade gliomas (LGGs) from TCGA and CGGA databases were determined by using ESTIMATE algorithm. Differentially expressed genes (DEGs) between high and low immune/stromal score groups were identified. Subsequently, weighted gene co-expression network analysis (WGCNA) was conducted to screen out aging TME related signature (ATMERS). Based on the expression patterns of ATMERS, LGGs were classified into two clusters with distinct prognosis via consensus clustering method. Afterwards, the aging TME score for each sample was calculated via gene set variation analysis (GSVA). Furthermore, TME components were quantified by MCP counter and CIBERSORT algorithm. The potential response to immunotherapy was evaluated by Tumor Immune Dysfunction and Exclusion analysis. We found that LGG patients with high aging TME scores showed poor prognosis, exhibited an immunosuppressive phenotype and were less likely to respond to immunotherapy compared to those with low scores. The predictive performance of aging TME score was verified in three external datasets. Finally, the expression of ATMERS in LGGs was confirmed at protein level through the Human Protein Atlas website and western blot analysis. This novel aging TME-based scoring system provided a robust biomarker for predicting the prognosis and immunotherapy response in LGGs.
Association between chronic rhinosinusitis and pneumonia: a longitudinal follow-up study using a national health screening cohort
Authors: Wee Jee Hye , Min Chanyang , Jung Hahn Jin , Park Min Woo , Park Bumjung , Choi Hyo Geun
Published: March 2022

This study was aimed to compare the risk of pneumonia between patients with chronic rhinosinusitis (CRS) and those without CRS (control) in a Korean population. The population aged 40 years or over was included from the Korean National Health Insurance Service-Health Screening Cohort. Participants with CRS (n = 6393) and controls (n = 25,572) were selected by 1:4 matching for age, sex, income, region of residence, and history of pneumonia for the previous 1 year. The index date (ID) of the controls was set as the treatment date of their matched CRS participants. The incidence of pneumonia after the ID was measured from 2003 to 2015. Simple and multiple linear regressions were performed to calculate estimated values (EVs) and 95% confidence intervals (CIs) for 1-y post-ID pneumonia, 2-y post-ID pneumonia, and 3-y post-ID pneumonia in CRS participants compared to controls. Statistical significance was noted in the 3-y post-ID period (EV = 0.017, 95% CI = 0.002–0.031, P = 0.030). In the subgroup analyses according to age and sex, statistical significance was seen in the younger age group (< 60 years old) in the 3-y post-ID period and in the female group in the 1-y and 3-y post-ID periods. This study revealed an increased risk for pneumonia following a diagnosis of CRS.
Improving the specificity of nucleic acid detection with endonuclease-actuated degradation
Authors: Zou Roger S. , Gavrilov Momcilo , Liu Yang , Rasoloson Dominique , Conte Madison , Hardick Justin , Shen Leo , Chen Siqi , Pekosz Andrew , Seydoux Geraldine , Manabe Yukari C. , Ha Taekjip
Published: March 2022

Nucleic acid detection is essential for numerous biomedical applications, but often requires complex protocols and/or suffers false-positive readouts. Here, we describe SENTINEL, an approach that combines isothermal amplification with a sequence-specific degradation method to detect nucleic acids with high sensitivity and sequence-specificity. Target single-stranded RNA or double-stranded DNA molecules are amplified by loop-mediated isothermal amplification (LAMP) and subsequently degraded by the combined action of lambda exonuclease and a sequence-specific DNA endonuclease (e.g., Cas9). By combining the sensitivity of LAMP with the precision of DNA endonucleases, the protocol achieves attomolar limits of detection while differentiating between sequences that differ by only one or two base pairs. The protocol requires less than an hour to complete using a 65 °C heat block and fluorometer, and detects SARS-CoV-2 virus particles in human saliva and nasopharyngeal swabs with high sensitivity.
Non-enzymatic catalytic asymmetric cyanation of acylsilanes
Authors: Nagano Tagui , Matsumoto Akira , Yoshizaki Ryotaro , Asano Keisuke , Matsubara Seijiro
Published: March 2022

The asymmetric cyanation of acylsilanes affords densely functionalized tetrasubstituted chiral carbon centers bearing silyl, cyano, and hydroxy groups, which are of particular interest in synthetic and medicinal chemistry. However, this method has been limited to a few enzymatic approaches, which employ only one substrate because of substrate specificity. Here we show the non-enzymatic catalytic asymmetric cyanation of acylsilanes using a chiral Lewis base as an enantioselective catalyst, trimethylsilyl cyanide as a cyanating reagent, and isopropyl alcohol as an additive to drive catalyst turnover. High enantio- and site-selectivities are achieved in a catalytic manner, and a variety of functional groups are installed in optically active acylsilane cyanohydrins, thus overcoming the limitations imposed by substrate specificity in conventional enzymatic methods. A handle for the synthetic application of the products is also established through the development of a catalyst for protecting acylsilane cyanohydrins, which are unstable and difficult to protect alcohols.
Recent trends of contrast agents in ultrasound imaging: a review of the classifications and applications
Authors: Tarighatnia Ali , Fouladi Mohammad Reza , Nader Nader D. , Aghanejad Ayuob , Ghadiri Hossein
Published: March 2022

Ultrasound (US) imaging, due to its capabilities of real-time imaging, portability, low cost and favorable safety, is frequently used as a diagnostic modality for the visualization of different diseases.
Cytotoxicity evaluation of sodium lauryl sulfate in a paper-based 3D cell culture system
Authors: Lee Young Ju , Ahn Yong Jin , Lee Gi-Ja
Published: March 2022

The 3D cell culture paper provided an appropriate environment for the growth of L929 cells. Cytotoxicity of SLS to cells in the paper-based 3D culture system was similar to a commercial 3D cell culture kit, but more sensitive than 2D cell culture.
Combining high activity with broad monomer scope: indium salan catalysts in the ring-opening polymerization of various cyclic esters
Authors: Bruckmoser Jonas , Henschel Daniel , Vagin Sergei , Rieger Bernhard
Published: March 2022

An indium salan-type catalyst shows very high activities in the ring-opening polymerization of various cyclic esters, including β-butyrolactone, γ-butyrolactone, lactide, ε-caprolactone and ε-decalactone.
Large easy-axis magnetic anisotropy in a series of trigonal prismatic mononuclear cobalt(ii) complexes with zero-field hidden single-molecule magnet behaviour: the important role of the distortion of the coordination sphere and intermolecular interactions in the slow relaxation
Authors: Landart-Gereka Aritz , Quesada-Moreno María Mar , Díaz-Ortega Ismael F. , Nojiri Hiroyuki , Ozerov Mykhaylo , Krzystek J. , Palacios María A. , Colacio Enrique
Published: March 2022

A N6-tripodal ligand allows the preparation of a family of prismatic mononuclear cationic CoIIcomplexes with SMM behavior. Their axial anisotropy, magnetic relaxation and hysteresis width are modulated by the anion effects on the crystal structure.
Explicating the amino acid effects for methane storage in hydrate form
Authors: Burla Sai Kiran , Pinnelli S. R. Prasad , Sain Kalachand
Published: March 2022

Methane gas storage in the hydrate form using amino acids.
Catalytic pyrolysis of coconut oil with Ni/SBA-15 for the production of bio jet fuel
Authors: Miro de Medeiros Aldo , de Sousa Castro Karoline , Gundim de Macêdo Mayara Lopes , Mabel de Morais Araújo Aruzza , Ribeiro da Silva Djalma , Gondim Amanda Duarte
Published: March 2022

Catalytic pyrolysis of vegetable oil is one of the potential routes to convert oil to drop-in biofuels, known as renewable hydrocarbons.
Strategies for the application of metal–organic frameworks in catalytic reactions
Authors: Gao Fei , Yan Runhan , Shu Yao , Cao Qingbin , Zhang Li
Published: March 2022

Metal–organic frameworks (MOFs) are promising candidates for catalyzation. This review primarily summarized the recent research progress in diverse strategies for tailoring MOFs which are endowed with more excellent catalytic behavior.
Process analytical technology (PAT): applications to flow processes for active pharmaceutical ingredient (API) development
Authors: Talicska Courtney N. , O'Connell Eamon C. , Ward Howard W. , Diaz Angel R. , Hardink Mark A. , Foley David A. , Connolly Douglas , Girard Kevin P. , Ljubicic Tomislav
Published: March 2022

Process analytical technology (PAT) applications pertaining to Pfizer's Flexible API Supply Technology (FAST) initiative.
Unraveling differences in aluminyl and carbene coordination chemistry: bonding in gold complexes and reactivity with carbon dioxide
Authors: Sorbelli Diego , Belpassi Leonardo , Belanzoni Paola
Published: March 2022

Aluminyls and carbenes as coordination ligands, although sharing similar electronic properties, reveal fundamental differences in their tunability, bonding to gold and reactivity of their complexes with carbon dioxide.
On the mineralization of nanocellulose to produce functional hybrid materials
Authors: Valencia Luis , Handa Rishab , Monti Susanna , Jasso-Salcedo Alma Berenice , Georgouvelas Dimitrios , Magaña Ilse , Díaz de León Ramón , Velikov Krassimir P. , Mathew Aji P. , Kumar Sugam
Published: March 2022

Nanocellulose (NC)-based materials constitute a new class of bio-based building blocks that are inspiring advances for the next generation of high-performance sustainable materials.
Homologous NiCoP@NiFeP heterojunction array achieving high-current hydrogen evolution for alkaline anion exchange membrane electrolyzers
Authors: Zhao Yingxia , Sun Ming , Wen Qunlei , Wang Shuzhe , Han Shengbo , Huang Leheng , Cheng Gao , Liu Youwen , Yu Lin
Published: March 2022

The homologous heterojunction array was constructed to achieve dual-regulation for charge distribution and mass transport. In a real AEM electrolyzer, our catalysts surpassed RuO2‖Pt/C activity at high current (1000 mA cm−2 @ ∼1.93 V) over 100 h.
A near-infrared light-driven photoelectrochemical aptasensing platform for adenosine triphosphate detection based on Yb-doped Bi2S3 nanorods
Authors: Gao Jie , Ding Yifan , Yan Kai , Zhang Jingdong
Published: March 2022

Yb-doped Bi2S3 nanorods with admirable near-infrared (NIR) photoelectrochemical (PEC) performance were proposed to fabricate a NIR light-driven PEC biosensor for highly sensitive and selective detection of ATP.
Comprehensive exploration of long-wave emission carbon dots for brain tumor visualization
Authors: Zhao Yifan , Xie Yandong , Liu Yuyang , Tang Xianglong , Cui Sheng
Published: March 2022

Stable long-wavelength emission carbon dots (R-CDs) have been synthesized to enable effectively visualize deep brain glioblastoma (GBM) by a liposome-formulated delivery system.
In situ growth of a 2D assisted passivation layer enabling high-performance and stable 2D/3D stacked perovskite photodetectors for visible light communication applications
Authors: Li Tengteng , Li Qingyan , Zhang Haijian , Zhao Hongliang , Wang Silei , Li Mengyao , Tang Xin , Ding Xin , Zhang Yating , Yao Jianquan
Published: March 2022

Two-dimensional (2D) perovskites have shown more considerable advantages in terms of stability than their three-dimensional (3D) counterparts.
Cooperative circumnavigation control of multiple unicycle‐type robots with non‐identical input constraints
Authors: Yu Yangguang , Miao Zhiqiang , Wang Xiangke , Shen Lincheng
Published: March 2022

For the robot control problems, the input constraint is an issue that must be carefully considered. Considering the control inputs of the robots in the multi‐robot system are constrained by different saturations in reality, we address the cooperative circumnavigation control problem of multiple unicycle‐type robots with non‐identical and unknown input constraints in this paper. A distributed control law is designed to drive the robots constrained by different and unknown input saturations to achieve the cooperative circumnavigation around a moving target. The algorithm proposed in this paper largely reduces the requirement for the maneuverability of the robots to achieve the cooperative circumnavigation. As long as the robots owns the basic maneuverability of circumnavigating around the target, it is proved rigorously that the proposed control algorithm can achieve the desired cooperation circumnavigation of the multi‐robot system. The effectiveness of the proposed method is validated by a numerical simulation.
Unipolar sinusoidal current excited switched reluctance motor control based on a 3D space vector modulation
Authors: Liu Jian , Wang Guofeng , Liu Di , Fan Yunsheng , Mu Dongdong
Published: March 2022

This paper reports on a novel unipolar current excited control scheme for the asymmetric bridge converter (ABC)‐based switched reluctance drive (SRD), where the 3D space vector modulation under three modes is developed to reduce the total harmonic distribution (THD) and torque ripple. Firstly, two different 3D vector distributions, namely, the small voltage amplitude mode and large mode are presented based on the asymmetric converter. For both distributions, the zero‐sequence voltages generated by the effective vectors are considered. Additionally, zero‐sequence vectors (1,1,1) and (−1,−1,−1) are no longer treated as null vectors and involved in the control of zero‐sequence current. Then, the duty cycles of both two modes are obtained by the combination of the zero‐sequence and two adjacent active vectors. Moreover, based on the large modulation mode, a novel method combined with the small mode is proposed to further optimise the switching costs and torque ripples. The effectiveness of the proposed modes is verified through the simulation in MATLAB and the experiment on a dSPACE‐1103‐based prototype. Compared with the conventional switched reluctance motor vector control, the proposed scheme delivers better performances of THD, efficiency and torque ripple reduction.
Bayesian multipath‐enhanced device‐free localisation: Simulation‐ and measurement‐based evaluation
Authors: Schmidhammer Martin , Siebler Benjamin , Gentner Christian , Sand Stephan , Fiebig Uwe‐Carsten
Published: March 2022

Device‐free localisation (DFL) systems infer presence and location of moving users by measuring to which extent they change the received signal power in wireless links. Consequently, users not only induce perturbations to the power of the line of sight but also to the power of reflected and scattered signals which are observed in the received signal as multipath components (MPCs). Since the propagation paths of MPCs differ inherently from the line‐of‐sight path, these propagation paths can be considered as additional network links. This extended network determines the multipath‐enhanced device‐free localisation (MDFL) system. Based on empirical models that relate perturbations in the received power of MPCs to the user location, the localisation problem can be solved by non‐linear Bayesian filtering. In this work, we investigate the point mass filter and the particle filter as possible solutions. We demonstrate the applicability of these solutions using ultra‐wideband measurements and develop and verify a numerical simulation framework that flexibly enables a sound evaluation of MDFL. Based on both measurements and simulations, we show a significant improvement of the localisation performance of MDFL compared to DFL. The overall localisation performance is thereby comparable for both filters. Eventually, we show that complexity and divergence probability, rather than localisation performance, are the decisive factors for the choice of the filter solution.
Schmerzen erkennen und begleiten – Kinder mit Komplexer Behinderung
Authors: Schlichting Helga
Published: March 2022

Wenn Kinder mit einer schweren Behinderung sich krank fühlen, leiden oder andere Beschwerden haben, können sie das oft nicht adäquat mitteilen. Umso wichtiger ist es, dass auch Therapeutinnen und Therapeuten die Anzeichen von Schmerzen erkennen und richtig bewerten können.
Aus dem Lot – Pusher-Symptomatik
Authors: Zietz Dörte , Johannsen Leif
Published: March 2022

Wer mit Patienten mit Pusher-Symptomatik arbeitet, weiß, wie kräftezehrend die Mobilisation in der Bewegungs- therapie sein kann – für Patient und Therapeut. Einen Goldstandard in der Behandlung gibt es bislang nicht. Zuerst sollte die Pusher-Symptomatik behandelt werden, bevor man andere Ziele der senso- motorischen Rehabilitation wie das Stehen und Gehen anvisiert.
Guia de cáncer de pene de la Sociedad Colombiana de Urología
Authors: Genes William Pertuz , Fierro Marino Cabrera , Guerrero Andrea Estrada , Lozano Angelica María Mikan , Rozo Yineth Camila Tunjano , Sánchez Andrés Felipe Pérez
Published: March 2022

El cáncer de pene tiene una incidencia de 1.11 por 100.000 habitantes en Colombia, representado en el 95% por carcinoma de células escamosas el cual representa una alta morbilidad y mortalidad, La Sociedad Colombiana de Urología realizo la adaptación de la guía de cáncer de pene para el año 2021 con revisión de la literatura, esta guía permite realizar una evaluación y tratamiento del cáncer de pene, en muchas ocasiones con el objetivo de preservación de órgano utilizando la ecografía como determinante para evaluar el compromiso de la lesión a las estructuras del pene, los estudios de extensión dependerán de hallazgos al examen físico como ganglios o compromiso local de la enfermedad, de acuerdo al tipo de lesión y su estadificación puede recibir terapia con agentes tópicos, radioterapia, cirugía láser, cirugía preservadora de órgano o penectomía total; La linfadenectomía inguinal permitirá mejorar la supervivencia en tumores de riesgo intermedio y alto (>pT1G2), posteriormente la quimioterapia adyuvante esta en el grupo de pacientes en el cual la intención sea curativa, aunque en terapia paliativa de segunda línea se encuentran los platinos y texanos como alternativa pero con pobre respuesta (<30%); los esquemas de seguimiento se realiza de acuerdo al estadio y el compromiso ganglionar. Al final se presentan los resultados de actividad sexual después de cirugía preservadora de órgano; Esta guía abarca la literatura actualizada del cáncer de pene, el cual es útil para el manejo por parte de los profesionales de salud del país.
Senna podocarpa Emulgel: A Herbal Alternative for Chemical Burn Wound Treatment
Authors: Isaac Johnson Ajeh , Daburi Aisha , Ifeanyi Benneth , Ben-Umeh Kenechukwu Chijioke , Adedokun Abiodun Abigail , Builders Philip
Published: March 2022

Senna podocarpa (SP) leaves are used in folk medicines for treatment of burns and wounds as poultices on wound surface. However, to the best of our knowledge, the wound healing ability of this plant has not been scientifically evaluated. This work aimed to determine the wound healing potential of the crude extract of SP leaves, and to evaluate the benefit of its preparation as an emulgel. In this study, the formulations of 2.5% of SP emulgel (F1) and 7.5% of SP emulgel (F2) were prepared by mixing the emulsion phase with the gel phase in a ratio of 1:1, and then physical appearance, globule size, pH, viscosity, swelling, water activity, extrudability, occlusion, spreadability, stability, and wound healing ability were determined. Phytochemical screening showed the presence of alkaloids, saponins, tannins, cardiac glycosides, flavonoids, anthraquinones, and phenols within the hydro-ethanolic extract of SP leaves, and high flavonoid content is believed to be responsible for its healing attributes. Our formulations showed acceptable physical properties. Hematoxylin-eosin and Verhoeff–Van Gieson stain showed that F2 could induce the accumulation of fibroblasts, fibrocytes, inflammatory cells, gland cells, epidermal cells, adipocytes, and collagen in the process of wound healing in mice injured with hydrochloric acid. Encouragingly, the percent of wound contractions in mice treated with F1, F2, and SP leaf poultice were 64, 87, and 50, respectively, suggesting the superior healing properties exhibited by SP emulgel over SP leaf poultice, and this may due to the occlusive property of emulgels. In conclusion, F2 of crude extract of SP leaves has better pharmacological effects on burn and wound healing, and may represent a preferred choice to treat burn wounds in the future.
Evaluación del desgaste laboral (burnout) y ansiedad en personal de salud burante la pandemia por Covid-19
Authors: Fernández Nicolás , Prada Stefania , Villanueva-Congote Juliana , Rodríguez Santiago
Published: March 2022

Objetivo La pandemia por Covid-19 ha tenido consecuencias en la sanidad mental del personal de salud, una población vulnerable que se encuentra en la primera línea de atención contra el virus. Los horarios de trabajo, así como el miedo de contagiarse y contagiar a la familia, generan niveles elevados de ansiedad y desgaste laboral. El objetivo de este estudio es evaluar la presencia de desgaste laboral y ansiedad en el personal de salud durante la pandemia de Covid-19.

Métodos Se aplicaron prospectivamente el Maslach Burnout Inventory y la escala de ansiedad de Hamilton de manera electrónica a 566 trabajadores de salud en Colombia durante marzo y abril del 2020. Adicionalmente, se evaluaron la edad, el nivel educativo, el estado civil, la ocupación, la fuente de ingresos, el tipo de contratación, el número de empleos, y las horas de trabajo del personal anteriormente mencionado.

Resultados En total, se evaluaron 566 profesionales de la salud, de los cuales 60,8% eran mujeres, y el 39.2%, hombres. La muestra comprendía 85,3% de médicos, 9,2% de enfermeros, y el 5.5% restante correspondió a personal administrativo, odontólogos y paramédicos. De estos, 19,3% tenía 3 o más empleos. En términos de desgaste laboral, se evidenciaron altos niveles de agotamiento emocional y despersonalización, con bajos niveles de realización personal. Adicionalmente, se evidenció ansiedad leve.

Conclusiones Unas de las consecuencias más importantes de la pandemia por Covid-19 son los efectos a nivel de desgaste laboral y ansiedad en el personal de salud. Dados nuestros resultados, es esencial resaltar la importancia de un acompañamiento psicológico al personal de salud en tiempos de miedo e incertidumbre.
Domain wall depinning from FM/AFM interface defects by spin-polarized current
Authors: Andrade F. A. L. , Diniz F. V. S. , Martins S. M. S. B. , Oliveira L. L. , Dantas Ana L. , Carriço A. S.
Published: March 2022

We report a theoretical investigation of the impact of spin-transfer torque on magnetic head-to-head domain walls of Fe and Ni80Fe20 (Permalloy PyTM) nanowires exchange coupled to a two-sublattice uniaxial antiferromagnetic substrate. Our results indicate that provided the interface exchange interaction is large enough, the domain walls pin to interface defects consisting of steps perpendicular to the easy antiferromagnetic axis, separating terraces with opposite effective interface exchange fields. We also found that the dipolar and interface energies lead to narrow V-shaped domain walls and that the spin-transfer torque effects are restricted to the domain wall. Depinning walls from the step defect at the interface require polarized spin current densities of the order of 107 A/cm2 for both materials.
Bare quantifiers and Verb Second
Authors: Rossi Silvia , Poletto Cecilia
Published: March 2022

The pre-participial syntax of the bare quantifiers tutto ‘everything’, molto ‘much’ and niente ‘nothing’ in Old Italian has been argued to be determined by the optional or obligatory presence of a classifier-like category n° in their internal structures (Poletto 2014; Garzonio & Poletto 2017, 2018). Their ‘upstairs’, i.e. CP syntax, however, does not seem to be sensitive to this distinction. All of these bare QPs are equally subject to the V2 property and can appear before the inflected verb, showing the exact same distributional properties. It will be shown, however, that on the basis of interpretative differences, tutto, molto and niente are not moved to the same projection: molto targets a lower projection in the focus field, we identify as Mod(ifier)P in Rizzi (2004), while tutto and niente target positions for either contrastive or ‘new information’ focus. More generally, this will be shown to follow from the pragmatic nature of the V2 phenomenon in OI.
Discourse relations and the German prefield
Authors: Speyer Augustin
Published: March 2022

The prefield in German declarative main clauses (i.e. the area left of the tensed verb) usually contains exactly one phrase. As I showed in earlier work, the phrase-selection is guided by information-structural factors, scene-setting elements being preferred over contrastive elements, which in turn are preferred over aboutness topics. This paper investigates the role of discourse relations on the ranking of possible prefield phrases. It turns out that discourse relations have a direct impact on the ranking (e.g. with Explanation, topics are preferred over contrastive elements) and that phrasal discourse relation markers enter the ranking, being the most preferred prefield fillers. In Early New High German texts, this tendency is even stronger.
Influence of contact geometry over the filament bond of polylactic acid blends
Authors: Ermolai V , Sover A , Nagîţ G
Published: March 2022

Fused Filament Fabrication is one of the most common Additive Manufacturing technologies among industrial and domestic users because of the satisfying quality of parts and the great variety of thermoplastic polymers available on the market. New possibilities were provided along with the equipment with multiple extrusion systems, referring to multi-colour and multi-material components. Besides part orientation during the manufacturing process, filament bond influences the mechanical properties of parts produced through Fused Filament Fabrication technology. This paper aims to investigate if the bond performance for polylactic acid-based polymers can be enhanced by designing new contact geometries, different from the current surface-to-surface approach. To comprehensively understand the influence of the designed bonding geometries over the tensile strength, all specimens were produced according to a factorial design of experiment method and contact geometries constrained with function related to the nozzle size.
Research on the solid-state joining of AlMg3
Authors: Feier A I , Banciu F V
Published: March 2022

Nowadays, new products are wanted to reach the final consumer as soon as possible, at the lowest possible costs and in the shortest possible time. This time limitation puts its mark on all the stages necessary for product development, implicitly on the stage of their conception. Given the need for products that require assembly, of major importance, in the design phase, becomes the choice of materials and ways of joining them, the parameters of the processes to be used, equipment, tools, devices with which it is made and then joint control. Having this knowledge inventoried, for the types of processes and materials possible to be used, the time in which the choice of the way of joining is made can decrease substantially. In this context, the present paper presents experimental tests on the solid-state joining of 3 mm sheets of AlMg3 alloy, a very well weldable material with WIG process, corrosion-resistant especially in the marine environment, very good formability at low temperatures. The solid-state joining procedure of the test specimens will be presented with the help of a modified milling cutter, and the conclusions of this type of joint highlighting also the destructive examination part of the tested specimens constitute a set of knowledge that can be inventoried, stored, and used, when necessary, in the products development process. The paper thus demonstrates the potential ease of applying and reproducing Friction Stir Welding (FSW) with simple machinery (CNC milling cutter), while contributing to an understanding of the mechanical behaviour (initialization of failure) of joints. This, the behaviour and the defects are very friendly explained in the macroscopic images from the paper.
Composite materials with polychromatic effects used in electrical installations
Authors: Drăghici Mircea Florin , Stoicanescu Maria
Published: March 2022

The article presents the importance of using composite materials with polychromatic and heat-sensitive effects that can be used in electrical components and have an important role in transmitting visual information on various parameters of electrical components or materials in which they are used. The main condition to use any composite material to be electrical isolator is the low conductivity. The polymers are the near with these requirements and it can be used in such domain. This paper proposes to use in some applications (with a method, which will be studied in detail in future research) a basic polychromatic and heat-sensitive polymer as an electrical insulator, which has good mechanical and durability properties and at the same time provides information on the state of the material in real-time (thermal properties, electrical properties, etc.). The connection between the material features and the domain in which this material is being used is very important. The research is based on both theoretical knowledge and practice (how to obtain the material and its properties).
Analytical crash analysis of heavy truck cabin structure according to regulation ECE-R29
Authors: Ioniţă A , Iozsa M D , Stan C , Manea A M
Published: March 2022

The safety of the occupants is the prime consideration for all commercial vehicles’ structure design. The truck cabin must be designed in such a way that the deformation patterns of the cabin structure during an impact can assure sufficient survival space for occupants. The objective of this study is to develop a CAD method to see the behaviour of the cab structure under the impact loads and the dynamic responses of the cab structure during two complex tests in line with ECE-R29regulation. In this paper, a finite element model of a lightweight cabin is built by using its Computer-Aided Design (CAD) model (which was developed by using CATIA software) and subjected to tests by using Ansys software. The test was made in order to evaluate the energy management and the cab strength under the loads. Finally, a solution is suggested to improve the cab’s response for optimization design in order to validate an ECE R29 test.
Modelling and simulation automatic braking systems for vehicles
Authors: Badea Gabriel , Toma Marius , Micu Dan Alexandru , Frăţilă Gheorghe , Saragea Ştefan
Published: March 2022

An automatic braking system is an important future step in attending the autonomous vehicle. This system increases the active safety of a vehicle, significantly reducing road accidents, and lowering the effects of accidents. The paper will present the steps that will develop the autonomous braking systems in conformity with the Society of Automotive Engineers (SAE) from the USA. As well the paper will present the modelling and simulating of the automatic braking systems of a vehicle from the middle class using LMS Amesim software.
Study regarding the reduction of energy, vibrations and noises generated by the car fan
Authors: Vranau A M , Caunii V , Bujoreanu C
Published: March 2022

The ventilation and air conditioning system is a complex and energy-consuming one. So far there is a lot of research in this area, but most of it is related to the study of soundproofing materials behind the dashboard and the modification of the air ducts. Our paper presents a more efficient constructive solution, which will reduce energy, noise and vibration. The purpose is to study air distribution systems with multiple fans. The number of small fans will be directly proportional to the seats in the car (depending on the type of car). The difference between the system proposed by us and the classic one is that the fans will start depending on the seats occupied by the passengers. Favourable results of studies can lead to high passenger comfort. Also, vibration reduction solutions for ventilation and air conditioning systems are all the more necessary in the case of silent electric cars.
Research regarding the effects of a diesel engine’s control unit retrofitting, focussing on its performance and pollution
Authors: Suciu C C , Ionel I , Ostoia D , Igreţ S V
Published: March 2022

Due to the stricter and stricter European restrictions on diesel engines, fewer manufacturers produce vehicles fuelled by diesel and since not anyone affords new vehicles and the out-of-use diesel vehicle waste would be huge. New ways of improving the pollution levels on currently registered vehicles must be found. The article presents a novel approach focusing on this scope, starting with the basic actual engine, and developing by retrofitting up to mechanical and software upgrades, aiming to raise the output of mechanical characteristics and simultaneous reduction of exhaust pollution. In short, the paper is focusing on research regarding the effects of a diesel engine’s control unit retrofitting.
Research on the automation of internal logistics activities in an assembly line
Authors: Pascu I G , Neacsu G C , Nitu E L , Beloiu R , Gavriluta A
Published: March 2022

The need for automation and digitization has led to a rapid evolution of internal logistics processes and systems. This paper presents the automation mode logistics activities in an assembly line, by integrating a robotic arm. For the integration of the robotic arm, several steps are followed, consisting in designing the assembly line and the robotic arm using the Process Simulate software, simulating the operation of the line for different scenarios for integrating the robotic arm and analysing them. The study is completed with the realization in the laboratory of the assembly line with automated logistics activities. At the end of the project, it is desired to use the automated assembly line in the university environment, for the formation of students' competencies in the field of use of digital techniques and industrial logistics.
Eigenfrequency simulation for a roller screw used at feed system for ultrasonically aided micro-electrical discharge machining
Authors: Cristea Bogdan-Ionut , Ghiculescu Liviu Daniel , Deopale Cristian
Published: March 2022

The current paper focuses on the problem of resonance between the own frequency (eigenfrequency) of the roller screw and the loads attached to it, and the frequency used by the command of the feed system to actuate the stepping motor in the process of ultrasonically aided micro-electrical discharge machining. If the roller screw assembly enters resonance, meaning equality of own frequency and the actuating frequency, it starts to vibrate with uncontrollable amplitude, introducing instability of the machining process. The frequency at which the command system operates is limited to a minimum of 50 Hz (for technological machining) and a maximum of 30 000 Hz (for rapid feed), limited by the maximum torque of the motor. The main frequencies in the operating domain are simulated in Comsol, to see if the roller screw resonates with the command system. The vibrations modes were also simulated, focusing on the torsional vibrations, induced by the command of the feed system, the case of this study. The results pointed out that the roller screw does not enter resonance.
Grease lubrication of miniature ball bearings
Authors: Ianuş G , Cojocaru D , Cârlescu V , Tufescu A , Olaru D N
Published: March 2022

Estimation of the power loss in miniature ball bearing grease lubricated is a complex problem. Usually the applied loads (radial and axial) have small values and the methodologies recommended by the bearing companies are cannot applied for these conditions. For a ball bearing, some friction processes have differential contribution to the total friction torque and power loss. For very low loads, the lubricant is the most important source for friction torque. In the present paper the authors determined experimentally the friction torque both in a standard 7000C angular contact ball bearing (ACBB) and a modified 7000C ACBB containing only 3 balls without cage, operating with very low axial load and lubricated with lithium soap grease. The experimental values of the friction torque have been correlated with the theoretical Houpert’s IVR model developed for hydrodynamic rolling resistances in ball race contacts considering the viscosity of the base oil of grease.
How to handle the design preferences with Axiomatic Design
Authors: Gonçalves-Coelho António , Fradinho João , Gabriel-Santos António , Cavique Miguel , Mourão António
Published: March 2022

Picking the best design solution among a small collection of viable alternatives is often a part of engineering design. The traditional method to do it is the weighted multicriteria decision procedure. However, the Axiomatic Design (AD) framework does not employ weighting factors to deal with design preferences. Instead, AD uses the careful placing of each design range. This paper stresses the reasons AD does not include weighting factors—an imaginary flaw that teachers and designers should not attempt to change because that would break the rational soundness of AD teaching and practice. A numerical example supports our rationale.
Adjustable suspension system for lower limb prosthesis
Authors: Spanu Alina Rodica , Besnea Daniel , Moraru Edgar , Elfarra Mazen , Chiriac Oana
Published: March 2022

The contact between the stump and the lower limb prosthesis has to be provided by its suspension system. The paper presents a solution for an adjustable suspension designed as an inflated cell network. Each cell is supplied with controlled pressure and consequently, a contact force with the skin is developed. By varying the pressure value inside the cell, we may provide variable force, so the compensation for the volume change of the stump could be accomplished. The material the cells are made of should have special properties, the elasticity being the most important. Moreover, the goal of the paper was to approve the opportunity to use the silicone rubber Zhermack for the cell material and a mechatronic system has been realised as experimental set-up.
Effect of lubricant shear thinning behaviour on major functioning parameters of a pad bearing operating in hydrodynamic lubrication region
Authors: Salodimitris C P , Nikolakopoulos P G
Published: March 2022

Type of lubricant used for fluid film bearings is one of the most important factors to consider. Bearing characteristics have to maintain steady throughout a wide range of conditions. However, viscosity, which is one of the primary lubricant properties, highly deviates depending on environmental and operational conditions. Macro-molecular micro-structure of lubricants is strongly correlated to temperature and shear rate, leading to a shear thinning behaviour. This work aims in studying a pad bearing lubricated by a shear thinning oil in hydrodynamic region. Hydrodynamic wedge was modelled for a small fixed pad bearing of 8.5 mm inner radius, 14.5 mm outer radius, 40° angle and 50 μm inlet – outlet film thickness difference. Variety of cases were studied for several runner rotational velocities and minimum film thickness. Lubricant was modelled as a carreau fluid. Load carrying capacity, power losses, friction coefficient, mass flow rate, temperature and viscosity were evaluated. From the aspect of load carrying capacity, this specific pad bearing is optimally operating for rotational velocities of up to 100 krpm. Above this threshold, viscosity highly downgrades due to increase in temperature and shear rate, causing a negative impact in load capacity. Shear thinning behaviour of lubricants is of high importance and should not be considered negligible.
Research concerning the influences related to the perforated hole diameters in long pipes
Authors: Poiană D I , Ionel I , Drăghici G
Published: March 2022

The purpose of this paper is to highlight the influence of the dimensional characteristics and mechanical strength characteristics of the pipe material on the diameter of the perforated holes in these long pipes, to maintain the stability of the pipe shape in the perforated area. The research aimed to establish the maximum limit dimensions of holes that can be made in long round pipes with thin walls, through perforating by cold plastic deformation in air, using only a punch applied to on the outside of the pipe, for a particular case of pipe clamping. Following the research, the mathematical relations between the maximum diameters of the holes that can be obtained in round pipes, in correlation with the dimensional characteristics and the mechanical resistance of the material, are presented. The characteristics taken into account are the outer diameter of the pipes, the thickness of the pipe wall, and the permissible resistance to rupture of the part material. In the conclusions, it is specified that the determined mathematical relations allow the construction of variation diagrams and the determination of the maximum possible diameters, for other dimensional characteristics of pipes and for other mechanical strength characteristics of different materials.
The impacts of the COVID-19 pandemic on surface passenger transport and related CO2 emissions during different waves
Authors: Mannattuparambil Philip Joppen , Shan Yuli , Hubacek Klaus
Published: March 2022

The coronavirus pandemic has severely impacted our day-to-day activities and brought about significant change in all major sectors, especially surface passenger transport. Lockdowns and stay-at-home restrictions have significantly reduced energy demand and consequently CO2 emissions of surface passenger transport. The change in CO2 emissions is calculated from near-real-time activity change data as a function of 3 confinement levels. The activity change and related emission trends reflect changes in the mode of transport during different waves, this can be used to understand mobility trends and patterns when stringent measures are imposed. Consequently, constructive use of this data can help prepare and develop the transport sector in case of another epidemic outbreak or other unprecedented calamities and to build a resilient transport infrastructure post-COVID-19. This study estimates and analyzes the changes in CO2 emissions associated with the public (bus and rail) and private surface passenger transport from March 1st, 2020 to Jan 31st, 2021 in 21 countries. The research period covers the 1st and the 2nd waves of COVID-19 in these countries. A higher activity reduction and consequently CO2 emission reduction is displayed during the 1st wave compared to the 2nd for most countries despite implementing stringent measures during both waves. This is in line with countries adapting to the ‘new normal’ and restarting socio-economic activities. Similarly, public transport recovery is slower than private transport recovery, making it essential to focus on reinforcement and adaptation of public transport infrastructure for the future. The results show that a cumulative 510 Mt CO2 has been reduced over 11 months in 21 countries, compared to pre-pandemic levels. This reduction brings about a 6% drop in transport CO2 emissions and a 1.5% drop in global CO2 emissions. This analysis sheds light on mobility trends and travel behavior of surface passenger transport modes and related CO2 emissions in different countries which can be used to exemplify the path to recovery based on near-real-time data.
3D coaxial bioprinting: process mechanisms, bioinks and applications
Authors: Shyam Mohan Tarun , Datta Pallab , Nesaei Sepehr , Ozbolat Veli , Ozbolat Ibrahim T
Published: March 2022

In the last decade, bioprinting has emerged as a facile technique for fabricating tissues constructs mimicking the architectural complexity and compositional heterogeneity of native tissues. Amongst different bioprinting modalities, extrusion-based bioprinting (EBB) is the most widely used technique. Coaxial bioprinting, a type of EBB, enables fabrication of concentric cell-material layers and enlarges the scope of EBB to mimic several key aspects of native tissues. Over the period of development of bioprinting, tissue constructs integrated with vascular networks, have been one of the major achievements made possible largely by coaxial bioprinting. In this review, current advancements in biofabrication of constructs with coaxial bioprinting are discussed with a focus on different bioinks that are particularly suitable for this modality. This review also expounds the properties of different bioinks suitable for coaxial bioprinting and then analyses the key achievements made by the application of coaxial bioprinting in tissue engineering, drug delivery and in-vitro disease modelling. The major limitations and future perspectives on the critical factors that will determine the ultimate clinical translation of the versatile technique are also presented to the reader.
Effect of processing and accelerated storage on the volatile composition and sensory profile of a tomato soup
Authors: Ströhla Lena C , Hidangmayum Krishnachandra S , Waehrens Sandra S , Orlien Vibeke , Petersen Mikael A
Published: March 2022

The volatile and sensory profile of pasteurized (95 °C, 18 min) and sterilized (120 °C, 14 min) tomato soup and its changes at accelerated storage conditions (37 °C and 42 °C) were identified, characterized, and correlated by predictive models. Sterilization led to more profound changes over storage compared to pasteurisation, showing enhanced levels of ‘dark’ odour, ‘burnt’ flavour, and ‘complexity’, while pasteurized soup had more pronounced ‘green’ odour, ‘vegetables’ flavour, ‘harmony’, and ‘freshness’. Over time, ‘dark’ and ‘burnt’ significantly increased for sterilized soups, whereas ‘green’ decreased significantly only for sterilized soup stored at 42 °C. The changes of ‘dark’, ‘green’, ‘off-flavour’, ‘burnt’, ‘harmony’, and ‘freshness’ were associated with formation of furans (furfural and 2-acetyl-5-methylfuran), and decline of unsaturated aldehydes like E-2-octenal and E,E-2,4-heptadienal. These compounds were identified to represent potential shelf-life markers, yet more studies on their odour activity in the tomato soup matrix are necessary to understand their contribution to the sensory quality. The construction of partial least squares models allowed the prediction of ‘green’, ‘off-flavour’, ‘burnt’, and ‘freshness’ based on selected volatiles. These models will be important tools in the process of predicting the end of shelf life, but need to be supplemented with consumer acceptability levels.