bluuebunny/crossref_metadata_2025 huggingface dataset:
Risk factors predicting upper urinary tract deterioration in children with spinal cord injury
Authors: Önal Bülent , Kırlı Elif A. , Selçuk Berin , Buğdaycı Derya , Can Günay , Çetinel Bülent
Published: November 2020

Aim

The aim of this study is to determine the risk factors predicting upper urinary tract (UUT) deterioration in children with spinal cord injury (SCI).

Methods

The medical records of 108 children with SCI who were referred to our unit between 1996 and 2018 were retrospectively reviewed. The data included general patient demographics, SCI characteristics, bladder management methods, presence of urinary tract infection, radiological evaluation of the UUT and lower urinary tract (LUT), and videourodynamic findings. The receiver operating characteristic (ROC) curve analysis was performed to determine the cutoff values of the maximum detrusor pressure during filling and the bladder volume ratio (BVR) for predicting UUT deterioration. Multivariate analyses were used to determine the risk factors predicting UUT deterioration.

Results

Complete data were available for 76 children. The median patient age was 15 years (2–17). The leading causes of SCI were motor vehicle accidents (44%) and fall (33%). UUT deterioration was identified in 33 patients (43%). Iatrogenic SCI etiology, abnormal radiological LUT findings, and detrusor pressures greater than 70 cmH2O were found to be independent risk factors for UUT deterioration using regression analysis. In addition, ROC analysis revealed that a BVR less than 0.7 was the cutoff value for UUT deterioration in children with SCI.

Conclusion

Abnormal radiological LUT findings, iatrogenic SCI etiology, detrusor pressure greater than 70 cmH2O, and a BVR less than 0.7 were independent risk factors for UUT deterioration in children with SCI.
On the observability inequalities of time discrete 2‐D integro‐differential systems in square domains
Authors: Xu Da
Published: November 2020

In this article, we consider an observability inequality of time discrete approximation schemes for a class of integro‐differential equations in square domains. The equation is discretized in time by the back‐ward Euler method in combination with Lubich's convolution quadrature. We derive uniform observability inequality for time discretization schemes in which the high frequency components have been filtered. In this way, the well‐known exact observability inequality of the integro‐differential systems (see Loreti and Sforza, Evolution Equations and Control Theory, 2018, Vol. 7, No. 1, pp. 61–77, Thm. 1.2) can be reproduced as the limit, as the time step Δt → 0. The time discrete observability inequality is established by means of a time‐discrete version of the classical harmonic analysis approach. Numerical experiments are presented to show the theoretical analysis.
Mechanism of acetaldehyde formation in polyethylene terephthalate resin—A new insight
Authors: Mahesh V. S. , Tharpa Kalsang , Gadigone Nitin S. , Al‐Farhood Bander F. , Al‐Mutairi Fayez H. , Kumar Arun
Published: November 2020

Acetaldehyde is one of the well‐known undesirable by‐product formed during different stages of polyethylene terephthalate manufacturing process. The migration of acetaldehyde from polyethylene terephthalate, even at trace levels of 10–25 ppb is known to adversely impact organoleptic property of water and/or beverages. We are reporting for the first time in‐situ formation of acetaldehyde in polyethylene terephthalate pellets due to the presence of residual levels of 2‐methyl 1, 3‐dioxolane in the final polymer. A new insight on generation of acetaldehyde through hydrolysis of 2‐methyl 1, 3‐dioxolane present in polyethylene terephthalate resin has been established through water spiking studies in a controlled environment. Further, systematic studies were conducted to also understand the mechanism of formation of 2‐methyl 1, 3‐dioxolane during the polyethylene terephthalate manufacturing.
Binary genetic algorithm for optimal joinpoint detection: Application to cancer trend analysis
Authors: Kim Seongyoon , Lee Sanghee , Choi Jung‐Il , Cho Hyunsoon
Published: November 2020

The joinpoint regression model (JRM) is used to describe trend changes in many applications and relies on the detection of joinpoints (changepoints). However, the existing joinpoint detection methods, namely, the grid search (GS)‐based methods, are computationally demanding, and hence, the maximum number of computable joinpoints is limited. Herein, we developed a genetic algorithm‐based joinpoint (GAJP) model in which an explicitly decoupled computing procedure for optimization and regression is used to embed a binary genetic algorithm into the JRM for optimal joinpoint detection. The combinations of joinpoints were represented as binary chromosomes, and genetic operations were performed to determine the optimum solution by minimizing the fitness function, the Bayesian information criterion (BIC) and BIC3. The accuracy and computational performance of the GAJP model were evaluated via intensive simulation studies and compared with those of the GS‐based methods using BIC, BIC3, and permutation test. The proposed method showed an outstanding computational efficiency in detecting multiple joinpoints. Finally, the suitability of the GAJP model for the analysis of cancer incidence trends was demonstrated by applying this model to data on the incidence of colorectal cancer in the United States from 1975 to 2016 from the National Cancer Institute's Surveillance, Epidemiology, and End Results program. Thus, the GAJP model was concluded to be practically feasible to detect multiple joinpoints up to the number of grids without requirement to preassign the number of joinpoints and be easily extendable to cancer trend analysis utilizing large datasets.
A Green Method for Synthesizing Nickel Nanoparticles Supported by Magnetized Pectin: Applied as a Catalyst for Aldehyde Synthesis as a Precursor in Xanthan Synthesis
Authors: Khashei Siuki Hossein , Bagherzade Ghodsieh , Ghamari Kargar Pouya
Published: November 2020

In this paper, the properties of a catalyst that composed of magnetic nanoparticles and Pectin biopolymer that is widely found in nature (Fe3O4@Pectin) to support nickel (II) acetate are discussed, and this catalyst was then used in response to the synthesis of the precursor required for xanthene synthesis. The heterogeneous catalyst was characterized by techniques such as FT‐IR spectroscopy, FE‐SEM, TEM, XRD spectroscopy, EDX spectroscopy, VSM, and ICP spectroscopy. Thermal gravimetric analysis (TGA) was also used to determine the thermal stability of the material techniques. Then the catalyst was explored in the oxidation reaction of alcohols that has high efficiency and selectivity and the synthesized aldehydes were used as precursors for the synthesis of xanthans. Xanthans are important compounds found in a variety of biological components and drugs. The most important advantages of this method are easy to work up procedure, perform the reaction in solvent‐free conditions, and the catalyst can be separated by an external magnet and used several times without reducing the activity.
Photosensitizer Modulated Turn – off Fluorescence System and Molecular Logic Functions for Selective Detection of Arsenic (III)
Authors: Shukla Shubhangi , Singh Shwarnima , Mitra Murli Dhar
Published: November 2020

The As3+ directed selective Fluorimetric turn ‘OFF’ sensor based on dual functions of fluorophore‐metal interaction and electron transfer between the emitter and light sensitizing moiety (PB‐MOF) has been formulated. Intermolecular charge transfer dependent changes in emission intensity were recorded owing to the metal ion‐induced modifications in coordinating potentials of PB‐MOF. Fluorescein shows successive enhancement in emission maxima (λem=520 nm) due to intermolecular activation in the presence of AgNPs and PB‐MOF. While interaction with As3+ leads to non radiative energy transfer at λem=520 in methanol, and the action of As3+ is selective over other ions (Na+, K+, Cs+, Ca2+, Mg2+, Cr3+, Mn2+, W+, Zn2+, Cd2+, Pb2+). Signal modulations based on the associating capabilities of sensitizer were epitomized to construct the integrated molecular logic gate system of OR, NAND, INHIBIT with single and double inputs. The enhancement and quenching phases were well evaluated through analytical as well as Boolean functions.
Pd(II)‐NNN Pincer Complexes for Catalyzing Transfer Hydrogenation of Ketones
Authors: Jerome Peter , Haribabu Jebiti , Bhuvanesh Nattamai S. P. , Karvembu Ramasamy
Published: November 2020

Chiral and achiral Pd(II)‐NNN pincer complexes (1–3) containing acetonitrile as an ancillary ligand were synthesized and characterized by spectroscopic (UV‐visible, FT‐IR, NMR and mass) techniques. Polarimetric experiments were employed to measure the specific rotation values of the chiral complexes {[α]D27= +135° (2) and −136° (3)}. The structures resolved through single crystal X‐ray diffraction technique disclosed the distorted square planar geometry of the complexes. Transfer hydrogenation (TH) reactions of ketones were carried out in order to appraise the catalytic efficiency of the complexes. Remarkably, the TH results were promising for all the complexes, however, the chiral complexes (2 and 3) failed to induce chirality. Further probe led us to believe that the pincer complexes turned into Pd particles in situ and the later acted as an active catalyst. The scope of TH was extended to various substituted aromatic and heterocyclic ketones (Conversions=75–99%).
Controllable Synthesis of MoS2/Carbon Nanotube Hybrids with Enlarged Interlayer Spacings for Efficient Electrocatalytic Hydrogen Evolution
Authors: Xu Wenwen , Dong Xiaoli , Wang Yu , Zheng Nan , Zheng Bingrong , Lin Qing , Zhao Yilin
Published: November 2020

Hydrogen, as a clean, affordable and reliable energy, is one of the important roles in clean energy conversion. In order to meet the demand of current energy, the hydrogen evolution reaction (HER) has attracted considerable attention as an effective process to produce hydrogen from water. Herein, we report a simple solvothermal synthesis of molybdenum disulfide (MoS2)/carbon nanotube (CNT) hybrids with enlarged interlayer distances ranging from 8.9 to 9.7 Å through controlling the CNTs loadings. The synergistic effects between CNTs and the layered MoS2 result in the high electrocatalytic activity for HER. MoS2/CNT‐2 catalyst with the enlarged lattice spacing of 9.7 Å shows the enhanced overpotential with 210 mV to reach the current density of 10 mA cm−2, 56 mV dec−1 Tafel slope, and good stability over 1000 cycles. This work provides a facile way to the fabrication of efficient MoS2‐based catalysts via modulating the interlayer spacing of MoS2 nanosheets.
Research on the game of network security attack‐defense confrontation through the optimal defense strategy
Authors: Liu Fei , Gao Hongyan , Wei Zegang
Published: November 2020

With the complication of attack means, the network security technology needs new changes. This study analyzed the establishment of the game model and strategy selection in the process of network security attack and defense confrontation. Firstly, the relevant theory of game theory was introduced; then the network attack and defense game model was established; the components of the model were analyzed; and finally, the Nash equilibrium of the hybrid strategy was solved to obtain the optimal defense strategy. The simulation results showed that the method could find the best attack and defense strategy {a3, d4} in the complex hybrid strategy. The calculation of payoff verified the correctness of the strategy. The experimental results show that the application of the attack‐defense confrontation in the network security field is feasible and it can effectively generate optimal attack‐defense strategy to realize network security.
Experimentation of digital multimedia forensics: State of the art and research gaps
Authors: OliveiraJr Edson , Zorzo Avelino F. , Neu Charles V.
Published: November 2020

Digital multimedia forensics (DMF) plays an outstanding role in digital forensics (DF) area as it encompasses solutions for promoting image, audio, and video evidence to be used in court. As every science, one straightforward way of evolving is conducting formal experiments and providing reliable and auditable evidence. Therefore, in this article, we systematically map and analyze how experiments in DMF have been conducted and whether data‐based evidence has been provided. This article presents a subset of results on DMF from a wider mapping study on DF experimentation. We then analyzed 49 experiments resulting from electronic and manual searches in widely known electronic databases and conferences/workshops on DF. We used them to answer six research questions. We demonstrated that DMF needs to improve the way experiments are reported, especially how data are shared to allow reproducibility and, consequently, evolution of the research topic. We show that experimental elements, for example, hypothesis, variables, design, instrumentation, validity evaluation, setup, training, data sets and benchmarks, statistical techniques (descriptive, hypothesis, and effect size test), and limitations, should be better reported. As a general result, we understand DMF formal experimentation needs to evolve toward providing useful, reliable, auditable, and reproducible experimental evidence as both academia and practitioners might straightforward benefit from such evolution.

This article is categorized under:

Digital and Multimedia Science > Multimedia Forensics
Parental Perspectives on Children’s School Readiness: An Ethnographic Study
Authors: Jose Kim , Banks Susan , Hansen Emily , Jones Rachael , Zubrick Stephen R. , Stafford Joel , Taylor Catherine L.
Published: November 2020

School readiness is a construct used by educators and policy makers to describe a range of abilities that are beneficial for children transitioning to school. The association of socioeconomic disadvantage with developmental vulnerability when children start school is well established. Parents play a crucial role in supporting children’s transition to school and are acknowledged as their child’s first and foremost teacher. The aim of this study was to explore how parents experience and support their children’s transition to school. This study presents findings from an ethnographic study with 39 parents living in two Australian communities characterised by high area-level socioeconomic disadvantage. The study reports on how parents experience and support their child for transition to school, specifically through their understanding of the concept of ‘readiness’. The role of early childhood services in supporting parents is also explored. Parents conceptualised school readiness as the child’s capacity to function effectively and independently in the hitherto unfamiliar physical and social world of school. Parents considered early childhood services supportive of their children's transition to school, particularly the development of social skills.
Dispositionality, categoricity, and where to find them
Authors: Azzano Lorenzo
Published: November 2020

Discussions about dispositional and categorical properties have become commonplace in metaphysics. Unfortunately, dispositionality and categoricity are disputed notions: usual characterizations are piecemeal and not widely applicable, thus threatening to make agreements and disagreements on the matter merely verbal—and also making it arduous to map a logical space of positions about dispositional and categorical properties in which all parties can comfortably fit. This paper offers a prescription for this important difficulty, or at least an inkling thereof. This will be achieved by comparing pairs of positions and exploring their background metaphysics to discover where alleged agreements and disagreements concerning dispositionality and categoricity really lie; more specifically, the Pure Powers view (according to which properties are just dispositional) and the Powerful Qualities view (according to which properties are also categorical) will be under scrutiny. Over this background, the prescription functions by isolating a successful identity-based characterization of categoricity, while abandoning the correspondent identity-based characterization of dispositionality. On the contrary, according to this prescription a property is dispositional if and only if it is solely in virtue of possessing that property that its bearer is assigned a certain dispositional profile. A crucial consequence of this prescription is that, while supporters of the Pure Powers view often characterize their position as an essentialist one, the dispositionality of properties needn’t always be a matter of essence.
No significant association between stable iodine intake and thyroid dysfunction in children after the Fukushima Nuclear Disaster: an observational study
Authors: Nishikawa Y. , Suzuki C. , Takahashi Y. , Sawano T. , Kinoshita H. , Clero E. , Laurier D. , Phan G. , Nakayama T. , Tsubokura M.
Published: November 2020

Purpose

Stable iodine prophylaxis helps prevent childhood thyroid cancer in nuclear emergencies; however, there is limited information on its effect on thyroid function. This study aimed to examine thyroid function and autoimmunity among children and adolescents that took stable iodine after the Fukushima Nuclear Disaster.

Methods

For this observational study, data were obtained from children and adolescents that underwent thyroid cancer screening at Hirata Central Hospital from April 2012 to March 2018. Participant characteristics, including possible hypothyroidism and hyperthyroidism, were compared between the prophylaxis and no-prophylaxis groups. Multivariable logistic regression models were used to assess for possible hypothyroidism, autoantibodies positive, and hyperthyroidism.

Results

A total of 1,225 participants with stable iodine prophylaxis and 3,946 without prophylaxis were enrolled. Of those participants, blood samples were available for 144 and 1,201 participants in the prophylaxis and no-prophylaxis groups, respectively. There were 17 (11.8%) and 146 cases (12.2%) of possible hypothyroidism or autoantibodies positive cases in the prophylaxis and no-prophylaxis groups, respectively, and there were no cases and 3 cases (0.2%) of possible hyperthyroidism in those two groups, respectively. Multivariable analysis for possible hypothyroidism revealed no association between stable iodine intake and possible hypothyroidism or autoantibodies positive [odds ratio 0.716 (95% confidence interval 0.399–1.284)] (p = 0.262). We did not perform multivariable analysis for hyperthyroidism due to the limited number of cases.

Conclusion

Significant adverse effects of stable iodine intake on thyroid function were not observed among children and adolescents 7 years after the Fukushima Nuclear Disaster.
The EU Rule of Law Initiative Towards the Western Balkans
Authors: Hoxhaj Andi
Published: November 2020

The EU adopted a new enlargement strategy for the Western Balkans countries in 2018, provided a time frame for Serbia and Montenegro potentially to join the Union by 2025, and outlined the next steps for accession for Albania, Bosnia and Herzegovina, Kosovo, and North Macedonia. In March 2020, the EU gave the green light to the opening of accession talks with North Macedonia and Albania, and also introduced a new reformed ‘accession talks’ framework. The strengthening of the rule of law, fighting corruption and organised crime are the cornerstones of the EU-Western Balkans strategy of 2018 and the new accession talks framework of 2020. This article examines the latest enlargement policy developments in 2018–2020 by conceptualising how the EU promotes the rule of law in the Western Balkans thorough its new enlargement policy package. Furthermore, the article offers an in-depth analysis of the case of Albania, where the EU has experimented with some of its latest enlargement-policy ideas in regard to the rule of law. The article also offers some proposals and insights on how the EU rule of law initiative of 2018 can be improved, in order to become more transformative in strengthening the rule of law in countries of the Western Balkans.
A DECORATED AND INSCRIBED STRAP-END FROM NUFFIELD, OXFORDSHIRE
Authors: Webster Leslie , Okasha Elisabeth , Williams David
Published: November 2020

The object described and discussed in this paper is a recently found Anglo-Saxon strap-end. Although incomplete, the strap-end is of interest in view of its rarity in being made of silver, of its decoration and of it containing an inscribed text. One part of the decoration is a depiction of the agnus dei. In the discussion, the decoration on the strap-end, and its significance, is set in the context of other instances of the agnus dei, both on artefacts and in manuscripts, from late Anglo-Saxon England.
Soviet Entrepreneurs in the Late Socialist Shadow Economy: The Case of the Kyrgyz Affair
Authors: Heinzen James
Published: November 2020

Supported by new archival material, this article delves deeply into one landmark criminal case to explore key aspects of the social, economic, and cultural history of illegal production and markets in the Soviet 1950s–60s. The goal of the article (and the larger project from which it draws) is to use archival research to shed light on major themes in Soviet history. It touches on three important and promising fields: everyday life under late Soviet socialism; the vibrant history of crime and law in this period; and the history of entrepreneurial activities within the hyper-centralized state-planned economy, focusing on the dynamics of the shadow economy. The so-called Kyrgyz Affair, a famous and expansive shadow economy operation centered in clothing factories in Frunze (Bishkek), Kyrgyz Republic, is at the center of the article. I argue that the scope, sophistication, ambition, and success of this and similar operations helps us understand a significant reason why Nikita Khrushchev decided to introduce the death penalty for aggravated cases of theft of state property and bribery in 1961–62. Associated with and fully permeating the shadow economy, one sees many varieties of practices, attitudes, informal institutions and agreements, and relationships.
A Tower of Tangled Histories: The Upper Silesia Tower in Poznań and the Making of an Unromantic Poland, 1911–1955
Authors: Babiracki Patryk
Published: November 2020

Engaging with regional, international, and spatial histories, this article proposes a new reading of the twentieth-century Polish past by exploring the vicissitudes of a building known as the Upper Silesia Tower. Renowned German architect Hans Poelzig designed the Tower for the 1911 Ostdeutsche Ausstellung in Posen, an ethnically Polish city under Prussian rule. After Poland regained its independence following World War I, the pavilion, standing centrally on the grounds of Poznań’s International Trade Fair, became the fair's symbol, and over time, also evolved into visual shorthand for the city itself. I argue that the Tower's significance extends beyond Posen/Poznań, however. As an embodiment of the conflicts and contradictions of Polish-German historical entanglements, the building, in its changing forms, also concretized various efforts to redefine the dominant Polish national identity away from Romantic ideals toward values such as order, industriousness, and hard work. I also suggest that eventually, as a material structure harnessed into the service of socialism, the Tower, with its complicated past, also brings into relief questions about the regional dimensions of the clashes over the meaning of modernity during the Cold War.
Association of hyperuricemia and gamma glutamyl transferase as a marker of metabolic risk in alcohol use disorder
Authors: Hernández-Rubio Anna , Sanvisens Arantza , Bolao Ferran , Pérez-Mañá Clara , García-Marchena Nuria , Fernández-Prendes Carla , Muñoz Alvaro , Muga Roberto
Published: November 2020

Excessive alcohol consumption leads to overproduction of urates and renal function plays a critical role in serum uric acid levels. We aimed to assess associations of hyperuricemia in patients with alcohol use disorder (AUD) and comparable Glomerular Filtration Rate (GFR). A total of 686 patients undergoing treatment for AUD between 2013 and 2017 were eligible (77% men); age at admission was 47 years [interquartile range (IQR), 40–53 years], age of onset of alcohol consumption was 16 years [IQR, 16–18 years] and the amount of alcohol consumed was 160 g/day [IQR, 120–240 g/day]. Body Mass Index was 24.7 kg/m2 [IQR, 21.9–28.4 kg/m2], eGFR was 105 mL/min/1.73 m2 [IQR, 95.7–113.0 mL], 9.7% had metabolic syndrome and 23% had advanced liver fibrosis (FIB-4 > 3.25). Prevalence of hyperuricemia was 12.5%. The eGFR-adjusted multivariate analysis showed that relative to patients with GGT ≤ 50, those with GGT between 51 and 300 U/L and those with GGT > 300 U/L were 4.31 (95% CI 1.62–11.46) and 10.3 (95% CI 3.50–29.90) times more likely to have hyperuricemia, respectively. Our data shows that hyperuricemia in the context of AUD is strongly associated with serum GGT levels and suggest an increased cardio-metabolic risk in this population.
Characterization of miR-200 family members as blood biomarkers for human and laying hen ovarian cancer
Authors: Choi Pui-Wah , Bahrampour Abbas , Ng Shu-Kay , Liu Sze Kei , Qiu Wei , Xie Fang , Kuo Winston Patrick , Kwong Joseph , Hales Karen H. , Hales Dale B. , Wong Kwong-Kwok , Norwitz Errol R. , Chow Chun Kin , Berkowitz Ross S. , Ng Shu-Wing
Published: November 2020

MicroRNA-200 (miR-200) family is highly expressed in ovarian cancer. We evaluated the levels of family members relative to the internal control miR-103a in ovarian cancer and control blood specimens collected from American and Hong Kong Chinese institutions, as well as from a laying hen spontaneous ovarian cancer model. The levels of miR-200a, miR-200b and miR-200c were significantly elevated in all human cancer versus all control blood samples. Further analyses showed significantly higher miR-200 levels in Chinese control (except miR-429) and cancer (except miR-200a and miR141) samples than their respective American counterparts. Subtype-specific analysis showed that miR-200b had an overall elevated level in serous cancer compared with controls, whereas miR-429 was significantly elevated in clear cell and endometrioid cancer versus controls. MiR-429 was also significantly elevated in cancer versus control in laying hen plasma samples, consistent with the fact that endometrioid tumor is the prevalent type in this species. A neural network model consisting of miR-200a/200b/429/141 showed an area under the curve (AUC) value of 0.904 for American ovarian cancer prediction, whereas a model consisting of miR-200b/200c/429/141 showed an AUC value of 0.901 for Chinese women. Hence, miR-200 is informative as blood biomarkers for both human and laying hen ovarian cancer.
PERK participates in cardiac valve development via fatty acid oxidation and endocardial-mesenchymal transformation
Authors: Shimizu Takashi , Maruyama Kazuaki , Kawamura Takeshi , Urade Yoshihiro , Wada Youichiro
Published: November 2020

Protein kinase R-like endoplasmic reticulum kinase (PERK) is one of the endoplasmic reticulum (ER) stress sensors. PERK loss-of-function mutations are known to cause Wolcott–Rallison syndrome. This disease is characterized by early-onset diabetes mellitus, skeletal dysplasia, and cardiac valve malformation. To understand the role of PERK in valve formation in vivo, we used an endothelial-specific PERK conditional knockout mice as well as in vitro PERK inhibition assays. We used ProteoStat dyes to visualize the accumulation of misfolded proteins in the endocardial cushion and valve mesenchymal cells (VMCs). Then, VMCs were isolated from E12.5 fetal mice, by fluorescence assisted cell sorting. Proteomic analysis of PERK-deleted VMCs identified the suppression of proteins related to fatty acid oxidation (FAO), especially carnitine palmitoyltransferase II (CPT2). CPT2 is a critical regulator of endocardial-mesenchymal transformation (EndoMT); however how TGF-β downstream signaling controls CPT2 expression remains unclear. Here, we showed that PERK inhibition suppressed, not only EndoMT but also CPT2 protein expression in human umbilical vein endothelial cells (HUVECs) under TGF-β1 stimulation. As a result, PERK inhibition suppressed mitochondrial metabolic activity. Taken together, these results demonstrate that PERK signaling is required for cardiac valve formation via FAO and EndoMT.
Bi(iii) MOFs: syntheses, structures and applications
Authors: Wang Qing-Xu , Li Gang
Published: November 2020

The synthesis methods, structures and applications of Bi(iii)-based MOFs in catalysis, adsorption, fluorescence, etc. are reviewed.
Nanoscale metal–organic framework composites for phototherapy and synergistic therapy of cancer
Authors: Bao Zhihong , Li Kexin , Hou Peipei , Xiao Ru , Yuan Yue , Sun Zhenhua
Published: November 2020

This review mainly discusses and summarizes the advancement of MOF-based nanocomposites as a therapeutic platform for cancer phototherapy or synergistic phototherapy within the last five years.
Investigation of CD26, a potential SARS-CoV-2 receptor, as a biomarker of age and pathology
Authors: Raha Animesh Alexander , Chakraborty Subhojit , Henderson James , Mukaetova-Ladinska Elizabeta , Zaman Shahid , Trowsdale John , Raha-Chowdhury Ruma
Published: November 2020

Objective: In some individuals, coronavirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection leads to a variety of serious inflammatory symptoms, including blood clotting and acute respiratory distress. Death due to COVID-19 shows a steep rise in relation to age. Comorbidities such as type 2 diabetes mellitus (T2DM), hypertension, and cardiovascular disease also increase susceptibility. It has been reported that T-cell regulatory dipeptidyl peptidase 4 (DPP4; cluster of differentiation 26 (CD26)) binds to the external spike (S) glycoprotein of SARS-CoV-2 as a receptor, for the viral entry into the host cell. CD26 is expressed on many cells, including T and natural killer (NK) cells of the immune system, as a membrane-anchored form. A soluble form (sCD26) is also found in the blood plasma and cerebrospinal fluid (CSF).

Approach and results: To investigate a possible relationship between sCD26 levels, age and pathology, serum samples were collected from control, T2DM and age-related dementia (ARD) subjects. A significant reduction in serum sCD26 levels was seen in relation to age. ARD and T2DM were also associated with lower levels of sCD26. The analysis of blood smears revealed different cellular morphologies: in controls, CD26 was expressed around the neutrophil membrane, whereas in T2DM, excessive sCD26 was found around the mononucleated cells (MNCs). ARD subjects had abnormal fragmented platelets and haemolysis due to low levels of sCD26.

Conclusions: These findings may help to explain the heterogeneity of SARS-CoV-2 infection. High serum sCD26 levels could protect from viral infection by competively inhibiting the virus binding to cellular CD26, whereas low sCD26 levels could increase the risk of infection. If so measuring serum sCD26 level may help to identify individuals at high risk for the COVID-19 infection.
Diffusivity-dependent fracturing processes and microseismic activity in granite
Authors: Baptista-Pereira Catarina , Gonçalves da Silva Bruno
Published: November 2020

Enhanced Geothermal Systems have relied on hydraulic fracturing to increase the permeability of rock reservoirs. The permeability enhancement depends on the connectivity between new and existing fractures. This, in turn, depends to a large extent on the interaction between the rock and the fracturing fluid, which not only pressurizes existing and new fractures but also diffuses into the rock matrix. In this research, the effect of the diffusivity of hydraulic oil on the fracturing processes and microseismicity of unconfined prismatic granite specimens was experimentally evaluated using visual and acoustic emission monitoring. The tests consisted of injecting hydraulic oil into two pre-fabricated flaws at two rates (2 ml/min and 20 ml/min), kept constant in each test. The fluid pressure inside the flaws was increased until hydraulic fractures propagated and the fluid front growing from the pre-fabricated flaws was visually monitored throughout the tests. It was observed that the fracturing pressures and patterns were injection-rate-dependent, which shows that diffusivity and poro-elastic effects play an important role in the hydraulic fracturing processes of granite. A smaller fluid front was observed for the 20 ml/min injection rate, associated to a lower volume injected and to a higher fracturing pressure when compared to the 2 ml/min injection rate. This was interpreted to be caused by the different pore pressures that developed inside of the rock matrix, which are function of the fluid front size. Microseismic activity was observed throughout the tests, becoming more intense and localized near the flaws as one approached the end of the test (i.e. visible crack propagation). While microseismic events were observed outside the fluid front region, their density was significantly larger within this area, showing that fluid diffusivity may contribute to an intensification of the microseismic activity.
Predicting the effective thermal conductivity of geo-materials using artificial neural networks
Authors: Shrestha Dinesh , Wuttke Frank
Published: November 2020

Soil thermal conductivity is an important thermal property used in heat transfer modelling and geo-energy applications. Because of its complex nature and depending on several factors such as porosity, moister content, structure, etc., it is always challenging to predict the thermal conductivity of geo-materials. In the past, many predictions models like theoretical, semi-empirical, empirical models have been proposed based on the experimental data. However, these models are more specific to certain boundary conditions. Therefore, in this study, an artificial neural network (ANN) approach was used to predict the thermal conductivity of geo-materials as a function of porosity, gradation and mineralogy. A comparison between existing prediction models and the developed ANN model for predicting thermal conductivity is also given.
Constitutive model describing the hydro-mechanical behaviors of compacted bentonite clay based on the crystal surface phenomena
Authors: Kyokawa Hiroyuki
Published: November 2020

A constitutive model for unsaturated expansive soil based on the crystal surface phenomena is proposed. The behavior of the proposed model is described as a double structure, with the soil skeleton and the interlaminar behaviors. The soil skeleton behavior is modeled by the Cam clay type model based on the Bishop’s effective stress, which can consider the degree of saturation-induced hardening and inelastic behavior in the over-consolidated region and is capable of describing hydraulic collapse. On the other hand, the interlaminar behavior is give as a result of the interlaminar equilibrium of clay minerals. The diffusion double layer repulsive force in the interlaminar equilibrium varies with the degree of saturation, and it mainly causes the hydraulic swelling of expansive soil. The performance of the model is validated through the simulations of the suction-controlled oedometer tests on the heavily compacted bentonite.
Cyclic mechanical stability of thermal energy storage media
Authors: Hailemariam Henok , Wuttke Frank
Published: November 2020

Closing the gap between supply and demand of energy is one of the biggest challenges of our era. In this aspect, thermal energy storage via borehole thermal energy storage (BTES) and sensible heat storage systems has recently emerged as a practical and encouraging alternative in satisfying the energy requirements of household and industrial applications. The majority of these heat energy storage systems are designed as part of the foundation or sub-structure of buildings with load bearing capabilities, hence their mechanical stability should be carefully studied prior to the design and operation phases of the heat storage system. In this study, the cyclic mechanical performance of a commercial cement-based porous heat storage material is analyzed under different amplitudes of cyclic loading and medium temperatures using a recently developed cyclic thermo-mechanical triaxial device. The results show a significant dependence of the cyclic mechanical behavior of the material, such as in the form of cyclic axial and accumulated plastic strains, on the different thermo-mechanical loading schemes.
Experimental study of pipe-pile-based micro-scale compressed air energy storage (PPMS-CAES) for a building
Authors: Zhang Jingtao , Seo Hoyoung , Kim Sihyun , Ko Junyoung , Kim Seunghee
Published: November 2020

Compressed air energy storage (CAES) technology has been re-emerging as one of the promising options to address the challenge coming from the intermittency of renewable energy resources. Unlike the large-scale CAES, which is limited by the geologic location, small-and micro-scale CAES that uses a human-made pressure vessel is adaptable for both grid-connected and standalone distributed units equipped with the energy generation capacity. The research team recently suggested a new concept of pipe-pile-based micro-scale CAES (PPMS-CAES) that uses pipe-pile foundations of a building as compressed air storage vessels. To ascertain the mechanical feasibility of the new concept, we conducted lab-scale pile loading tests with a model test pile in both a loose and dense soil chamber that emulates an actual closed-ended pipe pile. The test pile was subjected to a repeated cycle of compressed air charge (to Pmax=10 MPa) and discharge (to Pmin=0.1 MPa) during the experimental study. The displacement at the top of the test pile, with and without a structural loading, in loose and dense sand, was closely monitored during the repetitive air pressurization-and-depressurization. It was observed that the vertical displacement at the pile head under different conditions was accumulated during the extended cycle of air charge and discharge, but the rate of displacement gradually attenuates during the cycle. And, the presence of structural load and density of soil affected the magnitude of the accumulated vertical displacement. From the analysis, it can be concluded that the concept of PPMS-CAES is not likely to compromise the mechanical integrity of pipe piles while showing a promising capacity for energy storage.
Women’s clothing with eco design features
Authors: Atanasova Radka
Published: November 2020

In the paper, women’s wear with eco design features is created and manufactured. The object of the study is a dress in a semi-slim silhouette. The patterns of the garment are constructed automatically using a specialized CAD system. Algorithms for geometric construction of pieces and production patterns have been developed. The technology for manufacturing the dress has been composed. Markers for robotic cutting of the articles are planned. Three dresses are sewn. Each dress is decorated differently with elements cut from the fabric waste. The result of the proposed approach is three styles of clothing with three different unique looks with minimized textile waste. The artistic design of clothing with eco features demonstrates creative approach and good textile knowledge on the various methods of design and technological processing of materials. Using the fabric waste after cutting requires innovative thinking in order to make the garment attractive and to be preferred by a wider range of consumers. The production and successful sale of eco-friendly clothing occupies a worthy niche in the market.
Design of a Heat Exchanger Made of Gravity Heat Pipes with an Enlarged Heat Exchange Surface for Heat Dissipation from the Electrical Cabinet
Authors: Nemec Patrik
Published: November 2020

Due to the great progress in the electronics industry, heat management in electronic components is becoming a serious and important problem. Cooling of electronic components ensures a lower occurrence of failure of elements, longer service life of the device, protection against overheating of elements, further prevents malfunction of the device and loss of heat. In many cases, heat dissipation by natural convection is often insufficient. Heat dissipation by forced convection is effective, but it carries the risk of clogging the interior of the electrical cabinet with dust, which can negatively affect the functionality of the electrical elements over time. One of the possibilities of efficient heat dissipation from the electrical cabinet without forced convection is by means of heat pipe technology, which uses a phase change of the working substance for heat transfer. The article deals with the design, construction and experimental determination of the performance of gravity heat tubes with an increased heat exchange area suitable for the design of an electrical cabinet heat exchanger.
CFD Analysis of Impeller Trimming
Authors: Šlachtič Dušan , Knížat Branislav , Olšiak Róbert
Published: November 2020

Impeller trimming is a key impeller modification. It allows the best efficiency point (BEP) to be moved towards the region of lower flowrate and height, thus optimizing pump performance for specific piping systems. The paper deals with prediction of trimming results using CFD methods. Experience shows that modification of the BEP position depends on the trimming method as well as on the pump type and its specific speed. The analysed pump is of diagonal type with a specific speed of nb = 0.168. Its impeller is of a 4-blade design and a spiral casing is used as a volute. Seven cases of trimming are presented (including a non-trimmed original version). The paper compares CFD obtained data and data measured on an experimental stand. Additionally, the approach to CFD analysis, as well as the use of a turbulence model and characteristics of internal pump volume meshing are described.
Experimental Investigation and Numerical Modelling of Flow Characteristics of Non-Rotating Twin Screw Model
Authors: Drábková Sylva , Bojko Marian , Veselý Josef , Zapletal Rostislav
Published: November 2020

Twin-screw pumps employ clearances between both screws and screw rotors and housing, which cause backflow as function of pressure differential. Reduction of this flow can be reached by proper geometry design. For the experimental investigation, the scaled model 1:2 of the screws section was produced with trapezoidal tooth profile in two modifications differing in tooth width and pitch. Measurement of flow characteristics of non-rotating twin-screw model was carried out for validation and possible corrections of the 3D CFD model. The testing was done with non-Newtonian liquid met in the food industry and additionally also with water. Experimental data were partly compared with results obtained from numerical simulations.
Application of Knowledge of Fluid Mechanics in the Field of Design of Forming Tools
Authors: Moravec Ján
Published: November 2020

The paper deals with the construction of a hydrostatic molding tool. The theoretical part presents the necessary knowledge about forming in liquid media. The experimental part presents the construction of a forming tool for drawing using a liquid. The discussion deals with environmental constraints of production processes.
Landfill Gas Enrichment Impact at Net Caloric Value
Authors: Durcansky Peter , Jandacka Jozef , Michalkova Maria
Published: November 2020

Rising use of renewable energy sources has brought many new challenges and use of many unusual energy resources. These resources are often of lower quality, a by-product or simple waste. Landfill gas is one of resources with lower quality and unwanted elements, as sulphur derivatives. After chemical or another treatment, the gas can be used in any burning facility. This article presents numerical model, which deals with simulation of enrichment process for landfill gas and subsequent use in heat source, with simple gas burner. The final gas is simulated as gas mixture, with different components portions.
The Effect of Convection on the Thermal Power Change of Loop Thermosyphon
Authors: Polačiková Mária , Kapjor Andrej , Malcho Milan , Nemec Patrik
Published: November 2020

Creating thermal well-being and comfort for humans is now very natural and necessary. From the point of view of ensuring optimal operating conditions for electronic and electrical equipment, it is very important to provide a cooling system. For this reason, the research work deals with the creation of optimal conditions for rising temperatures in rooms with electronics. A combination of cooling systems is proposed to reduce the heat load of electronic components. The first part of the work generally describes the requirements for the design of refrigeration equipment and methods of heat dissipation by natural or forced convection. Depending on the requirement for low-energy equipment, a cooling system with a gravitational heat pipe and fans was designed in the second part of the work. The cooling system was installed in a closed electrical cabinet. The resulting values of the measurements indicated the evaluation of the transferred heat output in free and forced convection. The research also points to a comparison of the individual flow directions created by the fans.
Fitting & Extrapolation of Turbine Performance Maps of Automotive Turbochargers
Authors: Vondrák Adam
Published: November 2020

The study presents a detailed analysis of a contemporary method for fitting and extrapolation of turbine performance maps of automotive turbochargers. The complete algorithm is implemented in a MATLABTM based application with graphical user interface, the ultimate goal of which is to facilitate turbocharger performance data postprocessing. Guidelines are given on how to generate extrapolated maps from a fitted model considering the output data resolution. As a key validity criterion, fit quality of a sample measured turbine map is assessed using statistical and analytical methods. The report is concluded by a discussion of possible ways to improve the robustness of the algorithm with respect to input data of different origin and quality.
Influence of Biomass Combustion Method on Properties of Solid Fuel Residues
Authors: Trnka Juraj , Jandačka Jozef , Holubčík Michal
Published: November 2020

The correct course of the combustion process has a great influence on several output parameters. In addition to the impact on the performance and efficiency of the device, the impact on the formation and properties of gaseous emissions and solid residue is particularly noticeable. The solid combustion residue, in particular in the form of ash, remains trapped as the final product after combustion in the incinerator or may be released to the outside environment. Improperly, combustion can form two negative extremes. The first extreme is the formation of too fine dust particles of ash and solid pollutants escaping into the air as dangerous emission substances for human and other organism’s health. The second is the failure to burn larger pieces of fuel or sinter them into clumps, which can subsequently damage the combustion device or reduce the efficiency of combustion. This article aims to examine the various factors influencing the impact of combustion in different types of combustion plants on the properties of the resulting solid fuel residues and further possibilities of their use and effects on the environment.