bluuebunny/crossref_metadata_2025 huggingface dataset:
Computing one billion roots using the tangent Graeffe method
Authors: van der Hoeven Joris , Monagan Michael
Published: March 2021

Let
p
be a prime of the form
p
= σ2

k

+ 1 with σ small and let F

p

denote the finite field with
p
elements. Let
P
(
z
) be a polynomial of degree
d
in F

p

[
z
] with
d
distinct roots in F

p

. For
p
=5 · 2
55
+ 1 we can compute the roots of such polynomials of degree 10
9
. We believe we are the first to factor such polynomials of size one billion. We used a multi-core computer with two 10 core Intel Xeon E5 2680 v2 CPUs and 128 gigabytes of RAM. The factorization takes just under 4,000 seconds on 10 cores and uses 121 gigabytes of RAM.

We used the tangent Graeffe root finding algorithm from [27, 19] which is a factor of
O
(log
d
) faster than the Cantor-Zassenhaus algorithm. We implemented the tangent Graeffe algorithm in C using our own library of 64 bit integer FFT based in-place polynomial algorithms then parallelized the FFT and main steps using Cilk C.

In this article we discuss the steps of the tangent Graeffe algorithm, the sub-algorithms that we used, how we parallelized them, and how we organized the memory so we could factor a polynomial of degree 10
9
. We give both a theoretical and practical comparison of the tangent Graeffe algorithm with the Cantor-Zassenhaus algorithm for root finding. We improve the complexity of the tangent Graeffe algorithm by a factor of 2. We present a new in-place product tree multiplication algorithm that is fully parallelizable. We present some timings comparing our software with Magma's polynomial factorization command.

Polynomial root finding over smooth finite fields is a key ingredient for algorithms for sparse polynomial interpolation that are based on geometric sequences. This application was also one of our main motivations for the present work.
HPLC-MS and Network Pharmacology Analysis to Reveal Quality Markers of Huo-Xue-Jiang-Tang Yin, a Chinese Herbal Medicine for Type 2 Diabetes Mellitus
Authors: Chen Qiugu , Zhao Yuan , Li Maosheng , Zheng Ping , Zhang Shangbin , Li Huilin , Chen Jianping
Published: March 2021

Huo-Xue-Jiang-Tang Yin (HXJTY) is a Chinese medicine formulation, which has been widely used for the treatment of various lipometabolism- and glycometabolism-related diseases in clinics. Currently, HXJTY is mainly prescribed to treat patients with type 2 diabetes mellitus (T2DM), yet its chemical and pharmacologic profiles remain to be elucidated. Here, the potential bioactive compound and action mechanism were investigated using chemical and network pharmacology analysis. A rapid HPLC-MS was employed to identify and quantify the component of HXJTY. On the basis of the identified chemical markers from HXJTY, a network pharmacology study, including target gene prediction and functional enrichment, was applied to screen out the main quality markers of HXJTY and explore its potential mechanism for the treatment of T2DM. The results showed that a total of 22 components were identified and quantified from HXJTY by HPLC-MS. Furthermore, 12 active components such as astragaloside IV, calycosin-7-O-β-D-glucoside, hydroxysafflor yellow A, and others were proposed as quality markers of HXJTY for treating T2DM based on network pharmacology analysis. In addition, 125 corresponding possible therapeutic target genes of T2DM were obtained. These target genes are mainly related to peptidase activity, hydrolase activity, phosphatase activity, and cofactor binding, suggesting the involvement of PI3K-Akt, MAPK, AGE-RAGE, and Rap1 signaling pathways in HXJTY-treated T2DM. Our results may provide a useful approach to identify potential quality markers and molecular mechanism of HXJTY for treating T2DM.
Effect of Al2O3 on the Tensile and Impact Strength of Flax/Unsaturated Polyester Composite with Emphasis on Automobile Body Applications
Authors: Fenta Aynalem Gebre , Sirahbizu Belete
Published: March 2021

This study has endeavored to develop an Al2O3‐filled natural fiber reinforced polymer composite which is intended to substitute the most widely used synthetic E‐glass fiber material. To attain the desired objective of the work, 0, 5, 10, and 15 wt% Al2O3‐filled chopped flax/unsaturated polyester resin composite have been developed by the conventional hand‐lay‐up method followed by a compression molding process. Consequently, characterization and mechanical property tests are conducted based on the ASTM standard. The results revealed that both tensile and impact strength properties of the base chopped flax/unsaturated polyester resin composite are all affected due to the inclusion and variation of the content of Al2O3 in 15 and 25 wt% fiber loading cases. It has been noticed that a 39.06% increase in the ultimate tensile strength of the composite in 25/UPR‐5 composition has been gained. The effect of Al2O3 on the impact strength of the base composite has also been analyzed and a 45% increase has been observed in 15/UPR‐10 composition. The findings also witnessed that the newly developed composite can be applied to make automotive parts such as mud guard and engine undercover.
Phytochemical Analysis and Study of Antioxidant, Anticandidal, and Antibacterial Activities of Teucrium polium subsp. polium and Micromeria graeca (Lamiaceae) Essential Oils from Northern Morocco
Authors: Benali Taoufiq , Habbadi Khaoula , Bouyahya Abdelhakim , Khabbach Abdelmajid , Marmouzi Ilias , Aanniz Tarik , Chtibi Houda , Mrabti Hanae Naceiri , Achbani El Hassan , Hammani Khalil
Published: March 2021

The protection of agricultural crops and the preservation of the organoleptic and health qualities of food products represent a major challenge for the agricultural and agro-food industries. Essential oils have received greater attention as alternatives to replace the control strategies based on pesticides against phytopathogenic bacteria and synthetic compounds in food preservation. The aims of this work were to study the chemical composition of Teucrium polium subsp. polium and Micromeria graeca essential oils and to examine their antioxidant and antimicrobial effects. To carry out this work, the chemical composition of the essential oil was determined using gas chromatography (GC) with the detection feature of mass spectrometry (MS). Subsequently, the antioxidant activity was investigated by DPPH and FRAPS assays. The antimicrobial effect was studied against phytopathogenic and foodborne pathogenic bacteria using the disc and the microdilution methods. Our results showed that GC-MS analysis of EOs allowed the identification of 30 compounds in T. polium EO (TPpEO), while 5 compounds were identified in M. graeca EO (MGEO). TPpEO had as major compounds β-pinene (19.82%) and germacrene D (18.33%), while geranial (36.93%) and z-citral (18.25%) were the main components of MGEO. The most potent activity was obtained from MGEO (IC50 = 189.7 ± 2.62 µg/mL) compared to TPpEO (IC50 = 208.33 ± 3.51 µg/mL. For the FRAP test, the highest reducing power was obtained from 1.32 ± 0.1 mg AAE/g of TPpEO compared to MGEO 0.51 ± 0.13 mg AAE/g of EO. Both EOs exhibited varying degrees of antibacterial activities against all the tested strains with inhibition zones in the range of 9.33 ± 0.57 mm to >65 mm and MIC values from 0.19 to 12.5 mg/mL. However, MGEO exhibits an interesting anticandidal effect with inhibition zone 44.33 ± 0.57 mm. The findings of this research establish the riches of EOs on volatile compounds, their important antioxidant activity, and their antimicrobial effect against the bacteria tested.
Molecular Composition and Antibacterial Effect of Five Essential Oils Extracted from Nigella sativa L. Seeds against Multidrug-Resistant Bacteria: A Comparative Study
Authors: Dalli Mohammed , Azizi Salah-eddine , Benouda Hind , Azghar Ali , Tahri Maroua , Bouammali Boufalja , Maleb Adil , Gseyra Nadia
Published: March 2021

Nigella sativa L. (NS) and its volatile compounds are well known for their broad spectrum of effects. This study aimed to investigate the variability of the chemical composition and the in vitro antibacterial activity of five essential oils (Eos) originated from Morocco, Saudi Arabia, Syria, India, and France. These five samples were grown under different edaphic and climatic conditions. The agar diffusion method and microdilution method in 96-well plates were used to test the sensitivity of multidrug-resistant strains clinically isolated from patients (methicillin-resistant Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii), for the determination of the minimum inhibitory concentration and bactericidal concentration. Among all the investigated Eos, the monoterpenes were highly present in the chemical composition. Moroccan, Saudi Arabian, and Syrian seeds were characterized by the presence α-phellandrene (20.03–30.54%), β-cymene (12.31–23.82 %), and 4−caranol (9.77–14.27%). The Indian seeds were rich with 4-caranol (18.81%), β-cymene (14.22%), α-phellandrene (10.58%), and β-chamigrene (9.54%), while France NS was rich with estragole (20.22%) and D-limonene (14.63%). The minimum inhibitory (MIC) and bactericidal concentration (MBC) obtained for the four Eos (with the exception of France because of the low yield) tested were ranging from 3 to 40 μl/ml. Gram-positive (+) bacteria were slightly sensitive to the Eos tested than the Gram-negative (−) bacteria. The results of this study showed that the Eos of NS seeds show interesting antibacterial activity which could be associated to the existence of different bioactive compounds. Indeed, these compounds can be used for preventive or curative purposes in the face of the noncontrolled emergence of resistance to antibiotics.
Prevalence of Vitamin D Deficiency among Hemodialysis Patients in Palestine: A Cross-Sectional Study
Authors: Nazzal Zaher A. , Hamdan Zakaria , Natour Nihal , Barbar Maram , Rimawi Rawan , Salaymeh Eziyeh
Published: March 2021

Introduction. The level of vitamin D status and its relationship to kidney function and liver function among patients with and without type 2 diabetes were not studied among Palestinian hemodialysis patients before. The aim of this study was to assess the status of vitamin D in hemodialysis patients with and without type 2 diabetes and its determinants. Methods. Data were collected on 163 patients on hemodialysis therapy in the Nephrology Department at Najah National University Hospital. Information on age, sex, plasma 25 (OH)D, serum calcium, serum phosphate, parathyroid hormone, dialysis period, hypertension, diabetes, ALT, AST, albumin, alkaline phosphates, and BMI was obtained from the medical records. Data were analyzed using SPSS. Findings. The mean level of 25 (OH)D was 17.3 ± 10.5 ng/ml. Only 12.9% of subjects had 25 (OH)D levels >30 ng/ml, whereas 65% had levels between 10 and 30 ng/ml; the remaining 22.1% were severely vitamin D deficient (<10 ng/ml). Vitamin D deficiency was more prevalent among females. It was not related to PTH, calcium, kidney, or liver function tests. Conclusion. Vitamin D deficiency is highly prevalent among patients on hemodialysis with or without DM2.
A Sensitive File Abnormal Access Detection Method Based on Application Classification
Authors: Liu Hui , Xue Hanxing , Lu Hui
Published: March 2021

As the access control mode of notepad files cannot meet the requirements of risk control for sensitive file hierarchical access, this paper proposes an application classification-based detection method for abnormal access to sensitive files. The application classification and file classification, access control policy mapping, and basic and preset policy detection are designed. Combining the operating system’s identification control of different applications at runtime, we monitor the abnormal access of sensitive files by hierarchical applications. The cross-access experiment of different levels of application to different sensitive files verified the effectiveness and security of hierarchical access control strategy and sensitive file abnormal access detection and reduced the risk of disclosure of sensitive files.
Effects of Chronic Supplementation of L‐Arginine on Physical Fitness in Water Polo Players
Authors: Gambardella Jessica , Fiordelisi Antonella , Spigno Luca , Boldrini Lorenzo , Lungonelli Giulia , Di Vaia Eugenio , Santulli Gaetano , Sorriento Daniela , Cerasuolo Federica Andrea , Trimarco Valentina , Iaccarino Guido
Published: March 2021

Background. Ergogenic nutritional supplementation is sought by professional athletes for improving physical performance; nevertheless, scientific evidence to support the chronic use of L‐Arginine among water polo players is missing. Methods. Seventeen male professional water polo players were randomly assigned to assume 5 grams per day of L‐Arginine (n = 9) or placebo (n = 8) for 4 weeks. The players’ fitness level was assessed in the maximal speed swimming test. Ear lobe blood samples taken before and after the effort for serum lactate content were analyzed. A speed‐to‐lactate ratio was generated at the baseline and after 4 weeks of treatment. We also tested the effects of L‐Arginine in vitro, measuring NO production, mitochondrial respiration, and gene expression in human fibroblasts. Results. L‐Arginine did not modify BMI, muscle strength, and maximal speed at 200 meters after 4 weeks. However, L‐Arginine ameliorated oxidative metabolism to exercise as suggested by the statistically significant lower lactate‐to‐speed ratio, which was not observed in placebo‐treated controls. In vitro, L‐Arginine induced the expression of a key regulator of mitochondrial biogenesis (PGC1α) and genes encoding for complex I and increased the production of nitric oxide and the maximal oxygen consumption rate. Conclusions. Chronic L‐Arginine is safe and effective in ameliorating the oxidative metabolism of professional water polo players, through a mechanism of enhanced mitochondrial function.
Investigating the Effect of Urban New Technologies on the Iranian Lorry Drivers’ Behavior
Authors: Sheikholeslami Abdolreza , Ayazi Ehsan , Moghadari Ali
Published: March 2021

Most accidents are directly related to driving offenses, and drivers who commit more offenses are more prone to accidents. Therefore, reducing driving offenses can reduce accidents. In other words, the recognition of common driving offenses among heavy vehicle (truck) drivers and the effective factors in directing them to reduce driving offenses can consequently reduce the frequency and severity of accidents. It seems that there is a necessity for in-depth studies to carry out research on this topic. The main objective of this study is to identify and evaluate important factors affecting lorry drivers committing traffic offenses. To achieve the goals, the required information was categorized into six categories: traffic tonnage, not fastening the seatbelt, speeding, technical defect, talking on cell phone, and lacking towing worksheet; these factors are known as dependent variables. Also, its influencing factors—in the group of driver characteristics, vehicle, and mileage—were obtained by using a demographic questionnaire, Driving Behavior Questionnaire (DBQ), and interviews with 420 drivers over 60 days at Tehran Terminal. After correcting incomplete questionnaires, 351 drivers’ information was used for statistical analysis. The statistical analysis of data using a multivariate logistic regression model showed that drivers loading and unloading five or six times per month are less likely to commit overloading than drivers loading and unloading more than 12 times per month. The results also show that the distracted drivers with less slip behavior are less likely to commit unauthorized speed offenses and 85.4% are less likely to commit this violation. Finally, the statistical analysis showed that drivers with aggressive driving behavior were more likely to commit a lack of towing worksheet offenses.
Experimental and Theoretical Investigations of Hard Rocks at High Temperature: Applications in Civil Engineering
Authors: Luc Leroy Mambou Ngueyep , Marius Foguieng Wembe , François Ngapgue
Published: March 2021

This review paper aims to survey and discuss recent theoretical and experimental works reporting the temperature effects on the mechanical properties of rocks like granite, gabbro, gneiss, marble, sandstone, basalt, limestone, and argillite to permit the new challenge in this domain. The effect of high temperatures on various mechanical and physical material properties (Young’s modulus, porosity, tensile and compressive strengths, P‐wave velocity, permeability, thermal damage, and expansion) is analyzed. This work shows that hard rock mechanical and physical properties evolutions are strongly related to the evolution of the microstructure caused by the geological history, cracks nucleation occurrences, recrystallization, dehydroxylation, and dehydration reactions. However, it should be emphasized that these studies were not conducted on all types of intrusions and all rocks types. Meanwhile, it has been noticed that variations in temperature could lead to contradictory phenomena. Therefore, different trends were observed for the evolution of physical properties of rocks. There is an increase in porosity approximately 80% above 500°C. In general, for volcanic’s rock, the loss mass and thermal conductivity were drastically observed at low temperatures around 200°C with an antinomic phenomenon. Sandstone, granite, and argillite present the model whose behaviors with thermal load are too much explored accordingly with experiments compared with other rocks. Argillite at 200°C and sandstone and granite at 400°C undergo seriously damage. There is 100°C gap between the results obtained in real‐time and those obtained after cooling. Moreover, 300°C can be considered as the critical temperature for real‐time temperature heat treatment at which rocks lose almost about 80% of their performance. Otherwise, it is not easy to predict the behavior at high temperature of volcanic rocks like basalt and metamorphic rocks like gneiss which present the complexity in their behavior. For plutonic and metamorphic rocks, 600°C is the critical thermal load. At this temperature, the modulus of elasticity as well as the compressive strength of the most explored rock shows a significant decrease of about 75% for hard rocks. In sum, high temperature damages significantly the mechanical performance of rock. It is the reason for which these results may be useful to characterize the damage and thus predict the dramatic consequences of large temperature fluctuations on engineering structures in the rock.
TNF-α Increase in a Cohort of Depressive Patients
Authors: Groh Adrian , Jahn Kirsten , Walter Marc , Heck Johannes , Lichtinghagen Ralf , Janke Eva , L Schulze Westhoff M. , Deest Maximillian , Frieling Helge , Bleich Stefan , Kahl Kai G. , Heberlein Annemarie
Published: March 2021

Background. The model of neuroinflammation has been proposed as a possible explanation of depression. Investigations of serum levels of tumor necrosis factor-α (TNF-α) in depressed patients have previously shown contradictory results of increased and decreased levels of TNF-α during the treatment of depression. Methods. We compared the serum levels of TNF-α in two cohorts of patients suffering from depression (ICD-10 criteria): one cohort from a psychotherapeutic unit (

n
=
18

), where patients were treated with Cognitive Behavioral Analysis System of Psychotherapy (CBASP), and the other cohort from a psychiatric day care unit (

n
=
16

). Both cohorts were investigated at the beginning and at the end of treatment. The intensity of depression was measured by means of the Beck Depression Inventory, 2nd edition (BDI-II) at both time points. Results. We observed a statistically significant increase of TNF-α in the psychotherapeutic unit at time point 2 compared to time point 1 (

T
=
−
14.71

,

p
<
0.001

), but not in the psychiatric day care unit. In both cohorts, BDI-II scores at time point 2 were significantly decreased compared to time point 1 (psychiatric day care unit:

T
=
3.32

,

p
=
0.005

; psychotherapeutic unit:

T
=
6.22

,

p
<
0.001

). There was a significant correlation in the psychotherapeutic unit at time point 2 (

r
=
−
0.682

,

p
=
0.02

). Conclusion. As TNF-α was increased at time point 2 in the psychotherapeutic unit but not in patients of the psychiatric day care unit, we propose the different durations of pretreatments in both cohorts and the associated processes of neuroinflammation as a possible explanation for our results. The lack of information about the time course of TNF-α in depression could in general explain the huge variety of TNF-α levels in different cohorts of depressed patients reported in the literature.
Hormone-Dependent Prostate Cancers are Dependent on Rac Signaling for Growth and Survival
Authors: Goka Erik T. , Mesa Lopez Dayrelis T. , Lippman Marc E.
Published: March 2021

Prostate cancer remains a common cause of cancer mortality in men. Initially, cancers are dependent of androgens for growth and survival. First line therapies reduce levels of circulating androgens or target the androgen receptor (AR) directly. Although most patients show durable responses, many patients eventually progress to castration-resistant prostate cancer (CRPC) creating a need for alternative treatment options. The Rac1 signaling pathway has previously been implicated as a driver of cancer initiation and disease progression. We investigated the role of HACE1, the E3 ubiquitin ligase for Rac1, in prostate cancer and found that HACE1 is commonly lost resulting in hyperactive Rac signaling leading to enhanced cellular proliferation, motility and viability. Importantly, we show that a Rac inhibitor can attenuate the growth and survival of prostate cancer cells. Rac signaling was also found to be critical in prostate cancers that express the AR. Rac inhibition in androgen dependent cells resulted in reduction of AR target gene expression suggesting that targeting Rac1 may be an alternative method for blocking the AR signaling axis. Finally, when used in combination with AR antagonists, Rac inhibition enhanced the suppression of AR target gene expression. Therefore, targeting Rac in prostate cancer has the potential to enhance the efficacy of approved AR therapies.
A “libertação” entre cristãos e o conceito antropológico de ritual
Authors: Garcia Ypuan
Published: March 2021

Este artigo advém de pesquisa etnográfica realizada entre os anos de 2013 e 2016 com católicos na cidade de São Paulo/SP e se volta ao tema da “libertação”. Trata-se de descrever que para esses cristãos libertar, quando envolve o demônio, não acarreta necessariamente formas ditas rituais. Com isto em perspectiva, o propósito da  argumentação é sublinhar algumas questões relativas ao recorrente entrelaçamento analítico entre a libertação e o conceito  antropológico de ritual. Debato que este conceito, ao sugerir a replicação de um padrão, tem pouco alcance analítico diante de formas de vida cristãs carismáticas, pois empalidece algo crucial: as ações divinas não são passíveis de serem subsumidas a uma classe de eventos que se caracteriza por sucessões, sequências ou  repetições.
Disparities in Mortality and Cardiovascular Events by Income and Blood Pressure Levels Among Patients With Hypertension in South Korea
Authors: Shin Jeong‐Hun , Jung Mi‐Hyang , Kwon Chang Hee , Lee Chan Joo , Kim Dae‐Hee , Kim Hack‐Lyoung , Kim Woohyeun , Kang Si‐Hyuck , Lee Ju‐Hee , Kim Hyue Mee , Cho In‐Jeong , Cho Iksung , Lee Jun Hyeok , Kang Dae Ryong , Lee Hae‐Young , Chung Wook‐Jin , Ihm Sang‐Hyun , Kim Kwang Il , Cho Eun Joo , Sohn Il‐Suk , Kim Hyeon‐Chang , Park Sungha , Shin Jinho , Kim Ju Han , Ryu Sung Kee , Kang Seok‐Min , Pyun Wook Bum , Cho Myeong‐Chan , Sung Ki‐Chul
Published: March 2021

Background

Socioeconomic status is associated with differences in risk factors of cardiovascular disease and increased risks of cardiovascular disease and mortality. However, it is unclear whether an association exists between cardiovascular disease and income, a common measure of socioeconomic status, among patients with hypertension.

Methods and Results

This population‐based longitudinal study comprised 479 359 patients aged ≥19 years diagnosed with essential hypertension. Participants were categorized by income and blood pressure levels. Primary end point was all‐cause and cardiovascular mortality and secondary end points were cardiovascular events, a composite of cardiovascular death, myocardial infarction, and stroke. Low income was significantly associated with high all‐cause (hazard ratio [HR], 1.26; 95% CI, 1.23–1.29, lowest versus highest income) and cardiovascular mortality (HR, 1.31; 95% CI, 1.25–1.38) as well as cardiovascular events (HR, 1.07; 95% CI, 1.05–1.10) in patients with hypertension after adjusting for age, sex, systolic blood pressure, body mass index, smoking status, alcohol consumption, physical activity, fasting glucose, total cholesterol, and the use of aspirin or statins. In each blood pressure category, low‐income levels were associated with high all‐cause and cardiovascular mortality and cardiovascular events. The excess risks of all‐cause and cardiovascular mortality and cardiovascular events associated with uncontrolled blood pressure were more prominent in the lowest income group.

Conclusions

Low income and uncontrolled blood pressure are associated with increased all‐cause and cardiovascular mortality and cardiovascular events in patients with hypertension. These findings suggest that income is an important aspect of social determinants of health that has an impact on cardiovascular outcomes in the care of hypertension.
Comparative Studies between UK-Listed and Japan-Listed Banks
Authors: Mak Ka Wai , Rogge Ebbe
Published: March 2021

This paper studies (i) the effects of external directors and managerial ownership, and (ii) the effects of shareholder monitoring, on risk-taking at banks. The former is part of the internal control mechanisms, the latter of external control. It also examines the difference between control mechanisms in the UK and in Japan. It shows that shareholder supremacy is likely to weaken corporate governance at banks. In particular, it finds that: (i) the substituted effects between internal and external controls differ between countries, or that the substituted effects of governance mechanisms may not exist; (ii) an internal corporate governance approach to shareholder supremacy increases risk-taking at banks; and (iii) foreign shareholders are likely to increase risk-taking at banks.
Queer Theology and Youth & Young Adult Ministry
Authors: Canales Arthur David
Published: March 2021

This article is an invitation to Christian youth & young adult educators and ministers to be more understanding of queer theology and to discern its place within ministry to and for young people. The article examines the term “queer,” queer theology, and the placement of queer theology in youth & young adult ministry. Finally the article provides queer pastoral and pedagogical strategies and methods for integration into youth and young adult ministry.
Reflections on Ministry amongst Children during the Covid-19 Pandemic
Authors: Holmes Sarah , Sandsmark Astrid , Sonnenberg Ronelle , Weber Shantelle
Published: March 2021

The role and function of children’s ministry during the first six months of the Covid-19 pandemic is explored, including a comparison of observations from four different contexts: Norway, South Africa, The Netherlands, The United Kingdom. Theological reflection examines the emerging ecclesiologies, form and adaptation of sacramental practices and pastoral care of families during this time of crisis. This investigation acknowledges awareness that there were significant restrictions and consequent challenges facing churches during this time, causing implications on children’s ministry that were unprecedented and frustrating for the Church on a global scale. Observations and recommendations are presented to aid churches globally in ensuring that children’s ministry during such times of crisis is child-centred, values the child as part of the body of Christ, fosters intergenerational role modelling and solidarity, and helps rather than hinders children on their spiritual journey.
Effect of Zinc Oxide Nanoparticle Addition to Polycaprolactone Periodontal Membranes on Antibacterial Activity and Cell Viability
Authors: Seo Nuri , Park Chan , Stahl Alexander M. , Cho Hoonsung , Park Sang-Won , Yim Soon-Ho , Yun Kwi-Dug , Ji Min-Kyung , Kim Heesun , Yang Yunzhi Peter , Lim Hyun-Pil
Published: March 2021

During the design of membranes for guided tissue regeneration (GTR) to treat periodontal diseases, infection of the exposed membranes and postoperative complications can be prevented by increasing bacterial resistance. This study evaluated the antibacterial activity of PCL/ZnO membranes
and their effect on cell viability via addition of antibacterial zinc oxide (ZnO) nanoparticles to a biocompatible and biodegradable material such as polycaprolactone (PCL). Neat PCL membranes and PCL/ZnO membranes containing 0.5 wt.% and 5 wt.% ZnO were produced, and divided into PCL (0%
ZnO), LZ (0.5 wt.% ZnO), and HZ (5 wt.% ZnO) groups, respectively. The surface characteristics of the membranes including morphological features and changes in composition were analyzed. Adhesion of bacteria, including Streptococcus mutans and Porphyromonas gingi-valis, was analyzed
using a crystal violet assay. The proliferation of MC3T3-E1 osteoblasts was evaluated using a WST-8 assay. Significant differences were analyzed using the Kruskal-Wallis test (P < 0.05). The results of groups were compared using the Mann-Whitney test (P < 0.017). ZnO nanoparticles
were dispersed in the PCL matrix of PCL/ZnO membranes. Compared with neat PCL membranes, their ability to form crystals decreased and their amorphous structure increased. The adhesion of S. mutans and P. gingivalis in the LZ and HZ groups containing ZnO was significantly decreased
compared with that of the neat PCL membranes (P < 0.05). No significant differences were observed in the proliferation of MC3T3-E1 cells between the PCL/ZnO membranes and the neat PCL membranes both on days 2 and 5 of culture (P > 0.05). This study has demonstrated that the PCL membranes
carrying the ZnO nanoparticles inhibited bacterial adhesion without affecting the viability of osteoblasts, suggesting the potential application of ZnO in GTR to increase antibacterial activity of membranes.
Plasma Electrolytic Oxidation on Ti–xNb–2Ag–2Pt Alloys for Nano- and Micro-Pore Formation in Electrolyte with Ca and P Ions for Dental Implant Use
Authors: Kim Hyun-Jun , Choe Han-Cheol
Published: March 2021

In this study, plasma electrolytic oxidation (PEO) on Ti–xNb–2Ag–2Pt alloys for nano- and micro-pore formation in electrolyte with Ca and P ions for dental implant use was studied using various experimental equipment. The Ti–xNb–2Ag–2Pt
alloys were fabricated using a vacuum arc melting furnace, and micro-pores were created through PEO-treatment in an electrolyte containing Ca and P ions. The PEO-treated surface was observed by X-ray diffractometer (XRD), field-emission scanning electron microscopy, and energy dispersive X-ray
spectroscopy (EDS). The microstructure of Ti– xNb–2Ag–2Pt alloys showed the transformation of needle-like structure to equiaxed structure, as Nb content increased. Adding small amounts of Ag and Pt to Ti–xNb alloys, microstructure was not observed the significantly
difference compared to Ti–xNb. The nano- and micro-pore sizes increased as the Nb content increased after PEO-treatment of Ti-xNb. In the case of Ti–50Nb–2Ag–2Pt, groove structure was observed, also the Ca/P ratio increased as the Nb content increased. The oxide
layer thickness of Ti–xNb–2Ag–2Pt alloys was increased, as the Nb content increased.
Electrochemical Analysis of Nano- and Micro-Sized Pore Formed Ti–6Al–4V Alloys in Solution Containing Ca, P, Mn, and Si Ions via Plasma Eletrolytic Oxidation for Bio-Implant Materials
Authors: Kang Jung-In , Son Mee-Kyoung , Choe Han-Cheol
Published: March 2021

The purpose of this study was to investigate electrochemical analysis of nano- and micro-sized pore formed Ti–6Al–4V alloys in solution containing Ca, P, Mn and Si ions via plasma eletrolytic oxidation for bio-implant materials. The coatings were produced on Ti–6Al–4V
alloy for dental implant using the plasma electrolytic oxidation (PEO) method in electrolytes with the various concentration of 0, 5, and 20% Mn and Si, respectively. Electrochemical potentiodynamic polarization and AC impedance behaviors were carried out in 0.9% NaCl solution at 36.5 ±
1 °C using potentiostat (Potentiostat, EG&G, 362) and electrochemical impedance spectroscope (EIS, EG&G, 1025). The potentiodynamic polarization test with a scan rate of 1.667 mV s-1 was carried out from –1500 mV to 2000 mV. The frequency range used for EIS was
102–105 Hz. The amplitude of AC signal was 10 mV and 5 points per decade was used. From the potentiodynamic polarization test, PEO treated alloy in electrolyte containing Ca, P, Mn, and Si show a lower corrosion potential than that on the bulk surface. In the case
of Mn and Si doped surface, the corrosion resistance increase compared to non-doped surface with Mn and Si elements, and the current density was lower than that of the bulk surface. From the AC impedance test, in the case of Mn and Si doped surface, polarization resistance values were higher
than other specimens, and nano- and micro-sized pores were covered with corrosion product consisted Mn and Si elements.
Effect of Incorporating a Dimethacrylate Monomer on the Shear Bond Strength of Two Adhesive Resin Cements to Zirconia Ceramic
Authors: Lee Mun-Hwan , Kwon Tae-Yub , Kim In-Hye , Kim Young Kyung
Published: March 2021

Self-assembled nano-layering resulting from interaction of the phosphate functional group of adhesive monomers with zirconia ceramic surface has been proposed. The purpose of this study was to investigate the bond strengths of two adhesive resin cements (Panavia F 2.0 and BisCem) containing
phosphate monomers added with various concentrations (0.0, 1.0, 3.0, and 5.0 wt%) of triethylene glycol dimethacrylate (TEGDMA) to air-abraded zirconia ceramic. The polished/air-abraded zirconia plates (KaVo Everest® ZS-Ronde) were imaged using atomic force microscopy and the average surface
roughness (Ra) values were calculated (n = 5). The surface energy parameters of the zirconia plates and the resin cements were calculated based on the extended Fowkes theory. All resin-bonded (diameter: 2.38 mm) zirconia specimens were stored in water at 37 °C for 24 h and then
half of them additionally thermocycled 10,000 times before the shear bond strength (SBS) test (n = 10). Air-abrasion of zirconia surface significantly increased the γhS (hydrogen bonding component) value (p < 0.001), as well as greatly increasing
the surface area (p < 0.001). For both resin cements, the γhS (dipole–dipole component) gradually increased with increasing incorporated TEGDMA concentrations, whereas the γhS gradually decreased. Overall,
the addition of 3.0 wt% of TEGDMA consistently resulted in higher SBS values even after thermocycling. Under the tested condition, reducing the concentration of the adhesive monomers with phosphate functional group by adding the dimethacrylate monomer (up to 3.0 wt%) increased the bond strength
between the resin cements and zirconia ceramic.
Preparation and Evaluation of Nanostructured Lipid Carrier for Topical Delivery of Velutin: Synthetic Tyrosinase Inhibitor
Authors: Cheon Se Hyeop , Park Sang Yeob , Sung Ji-Hun , Lee Jeong Gi , Choi Se-Hee , Jang Ji-Won , Kim Hee-Cheol , Kim Sung Tae , Jeong Sehoon , Lee Kooyeon , Jang Dong-Jin
Published: March 2021

The purpose of this study is to produce nanostructured lipid carrier (NLC) that can solubilize poorly water-soluble velutin and verify an improved tyrosinase synthesis inhibition. A solubility test for velutin was conducted. Cetyl palmitate and caprylic/capric triglyceride were selected
as solubilizer. The lipid matrix was produced using the ultrasound dispersion method. The morphology and size distribution of the produced NLC was analyzed through scanning electron microscopy (SEM) and dynamic light scattering (DLS), and the release and tyrosinase inhibition of velutin was
evaluated through the Franz diffusion cell method and tyrosinase inhibition assay. Lipid matrix nanoparticles showed an average size of approximately 250 nm and polydispersity of 0.2, and it was confirmed that the velutin incorporated within nanoparticles sustained release at a constant rate
over 36 hours. Due to extremely low aqueous solubility, the tyrosinase synthesis inhibition of velutin suspension was 0%, and the value of velutin incorporated within the NLC formulation was greatly improved 56.5% (40 μg/mL). As a result, it was verified that lipid-based NLC nanoparticles
are an efficient formulation for the topical delivery of poorly water-soluble flavonoids such as velutin.
Hydrogenation of Ethylbenzene Over Ru/γ-Al2O3 Catalyst in Trickle-Bed Reactor
Authors: Oh Seung Kyo , Ku Huiji , Han Gi Bo , Jeong Byunghun , Park Young-Kwon , Jeon Jong-Ki
Published: March 2021

The objective of this study is to evaluate the catalytic performance of pellet-type Ru/γ-Al2O3 as a catalyst during liquid-phase hydrogenation of the aromatic hydrocarbon. The Ru/γ-Al2O3 catalyst was prepared using a wet impregnation
method. After adding a binder to Ru/γ-Al2O3, a pellet-type catalyst was obtained through an extrusion method. Nanoporous structures are well developed in the pellet-type Ru/γ-Al2O3 catalyst. The average pore sizes of the Ru/γ-Al2O3
catalysts were approximately 10 nm. The catalytic performance of the pellet-type Ru/γ-Al2O3 catalyst during ethylbenzene hydrogenation was evaluated in a trickle-bed reactor. When the ruthenium loading increased from 1 to 5 wt%, the number of active sites effective
for the hydrogenation of ethylbenzene increased proportionally. In order to maximize the conversion of ethylbenzene to ethylcyclohexane, it was necessary to maintain a liquid phase hydrogenation reaction in the trickle bed reactor. In this regards, the reaction temperature should be lower
than 90 °C. The conversion of ethylbenzene to ethylcyclohexane on the Ru(5 wt%)/γ-Al2O3 catalyst was highest, which is ascribed to the largest number of active sites of the catalyst.
Oxidation of Acetaldehyde Over Cobalt Supported on Nanosized Carbon Black Catalysts
Authors: Yoon Hyung-Sun , Seo Seong-Gyu
Published: March 2021

In this study, we investigated the oxidation of acetaldehyde over Co/carbon black catalysts. All experiments were conducted in the temperature range of 200–440 °C, at an acetaldehyde concentration of 0.94 mol% in air, and using Co loading amounts in the range of 2–60
wt%. The nanosized carbon black and Co/carbon black catalysts were characterized using thermogravimetric analysis (TGA) and X-ray diffraction (XRD) analysis. The TGA data revealed that the nanosized carbon black was stable at high temperatures (600 °C), and the XRD results indicated that
Co/carbon black was deteriorated and Co oxides, such as Co3O4, were formed. The addition of Co3O4 crystallites on the catalyst surface provided the greatest increase in catalytic activity. The catalytic activity of the supports used in this study
for the acetaldehyde oxidation reaction increased as follows: SiO2 < TiO2 < carbon black < SiO2–Al2O3. The experimental results and economic considerations revealed that nanosized carbon black could be effectively used as
catalyst support for the oxidation of acetaldehyde. The activity of the Co/carbon black catalysts varied with the Co loading amount, and the optimum Co loading amount was 10 wt%.
Catalytic Pyrolysis of Waste Achyranthes Root Over Al-MCM-41
Authors: Lee Seul-Bee , Kim Young-Min , Park Ji-Hui , Park Young-Kwon
Published: March 2021

This study examined the thermal and catalytic pyrolysis of waste Achyranthes Root (AR) using pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). The non-catalytic pyrolysis of waste AR produced various kinds of oxygenates, such as acetic acid, hydroxy propanone, furfural,
phenol, cresol, guaiacols, syringols, and so on. By applying nanoporous Al-MCM-41 with acidic properties and mesopores to the pyrolysis of waste AR, the levels of furan and aromatic hydrocarbons production increased with a concomitant decrease in the other oxygenates. The formation efficiency
of furans was improved further by increasing the amount of Al-MCM-41 applied to the catalytic pyrolysis of waste AR.
Molecular Dynamics Study on Graphene-Nanoflake Sensor Sandwiched Between Crossed Graphene-Nanoribbon Junctions
Authors: Kang Jeong Won , Kim Ki-Sub , Kim Hag-Wone , Kwon Oh Kuen
Published: March 2021

We present a design of a nanoscale inertial measurement unit or a data archive using a graphene-nanoflake (GNF) sandwiched between crossed graphene-nanoribbon (GNR) junctions. When an external force applied is below the retracting force, the inertial force exerted on the movable GNF
can telescope it. Then, the self-restoring force increases as the attractive van der Waals force between the GNF and the GNRs, which enables the GNF to automatically and fully retract back into the sandwich position immediately after the externally applied force is released. When the external
force exceeds the retracting force, the GNF escapes from the crossed GNR junctions, which enables the device to be used as non-volatile memory. The heterostructure of GNR/h-BN/GNR can be considered as an advanced structure in the proposed scheme.
Photocatalytic Reaction Properties of TiO2-Supported on the Long Lasting Phosphor: Sr4Al14O25:Eu2+,Dy3+
Authors: Sung Hyun-Je , Jung Sang-Chul , Kim Jung-Sik
Published: March 2021

The TiO2/Sr4Al14O25:Eu2+,Dy3+ photocatalytic composite was prepared by depositing the nano-crystalline titanium dioxide layer on the long-lasting phosphor substrate of strontium aluminate, using a low-pressure chemical vapor deposition (LP-CVD).
The photocatalysis characteristic was studied by examining the photodegradation of benzene (C6H6) gas under UV, visible light illumination, and in the darkness. The photocatalytic composite of TiO2-deposited Sr4Al14O25:Eu2+,Dy3+
showed an active photocatalytic reactivity under UV-light as well as visible-light illumination. The mechanism of the photocatalysis reaction for the TiO2-deposited strontium aluminate phosphor composite was interpreted in point of the energy band structure and phosphorescent emission.
The coupling of nanocrystalline TiO2 with the strontium aluminate phosphor might result in an energy band bending at the interface of TiO2/Sr4Al14O25:Eu2+,Dy3+, making the titanium dioxide at the junction to be photo-reactive
even in a visible wavelength region. In addition, the depth profile of Auger electron spectroscopy (AES) confirmed a possible formation of oxygen vacancies at the interface between TiO2 and Sr4Al14O25:Eu2+,Dy3+. Then, oxygen
defects create extra electrons which may excited subsequently to the conduction band and participate in a photocatalytic reaction, resulting in an enhancement of the photodecomposition of benzene. The LP-CVD TiO2-strontium aluminate phosphor was also photoactive in the darkness
because of light emission from the long lasting phosphor. Also, the TiO2-deposited Sr4Al14O25:Eu2+,Dy3+ long lasting phosphor was analyzed by a XRD (X-ray diffraction), TEM (transmission electron microscopy), UV/visible spectroscopy
and AES.
New Thermal Latent Catalyst Using Titanium and Organic Ligand for Urethane Polymerization
Authors: Kwon Hyukmin , Kang Seokwoo , Kim Seunghyun , Park Sunwoo , Park Sangshin , Lee Seungeun , Park Jongwook
Published: March 2021

New thermal-latent metal catalyst such as tetrakis (lauorate) titanium (LPTi) was designed and synthesized based on a lauroyl peroxide and titanium. The synthetic method is simple with one step reaction. LPTi structure was confirmed by FT-IR analysis, also nano-sized structure of LPTi
confirmed using SEM-EDX. LPTi is thermal-latent metal catalyst including titanium that not only promotes urethane synthesis reaction but also increases the dissociation rate of blocked isocyanate. As a result of quantitative analysis of NCO (%) through back titration, when LPTi was added,
NCO (%) increased from 2.34% to 3.24%. LPTi can be used as an excellent catalyst for urethane reaction by reducing the polymerization time by about 30% compared to no catalyst. LPTi can be applied to the electronic polymer synthesis.
The Effects of Fe Film Thickness and the H2 Annealing Time on the Spin-Capability of Carbon Nanotube Forest with Chemical Vapor Deposition Method
Authors: Choi Ye Il , Han Maeum , Dousti Behnoush , Lee Gil S. , Jung Daewoong
Published: March 2021

The effects of as-deposited iron (Fe) film thickness and the hydrogen (H2) annealing time on the spin-capability of carbon nanotube (CNT) forest have been studied. Both, the as-deposited Fe film thickness and the H2 annealing time significantly changed the morphology
of Fe nanoparticles (NPs) after annealing process during the synthesis step of spin-capable carbon nanotube (SCNT) forest. The spin capability of CNT forests depended heavily on the different thicknesses of Fe films and the H2 annealing time. In conclusion, the spin-capability of
CNT forest can be achieved by controlling the initial Fe film thickness and/or the H2 annealing time.
Biocompatible Flexible Carbon Fabric for Joule Heaters With and Without Graphene Oxide Coating
Authors: Kim Do-Hoon , Lee Jae Hyun , Son Seok-Kyun , Kim Ki-Taek
Published: March 2021

In this study, we demonstrate a carbon-based fabric Joule heater with and without a graphene oxide (GO) thin coating. The electrothermal performance of the carbon fabric used in the Joule heater was obtained using an infrared camera and by conducting electrical measurements. The outer
GO could control the electrothermal efficiency and heating rate. In this research work, using the Joule heating of thin graphene films, we report adaptive thermal heating with electrical control covering temperatures ranging 30 to 50 °C (near infrared). This electrothermal GO materials
can be potential nano-materials for various functional applications. Moreover, we demonstrate a general approach to achieve spin-coating of GO and confirm its biocompatibility Such biocompatibility indicates the non-toxic nature of GO, thereby extending its possible use in biomedical applications.
Low Resistivity Hafnium Nitride Thin Films Deposited by Inductively Coupled Plasma Assisted Magnetron Sputtering in Microelectronics
Authors: Chun Sung-Yong
Published: March 2021

Hafnium nitride (HfN) thin films with low electrical resistivity were obtained by inductively coupled plasma assisted magnetron sputtering as a function of ICP power. Microstructural, crystallographic and sheet resistance characterizations of HfN films were performed by field emission
scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and 4 point probe method. The results show that ICP has significant effects on coating’s microstructure, structural and electrical properties of HfN films. With an increase in ICP power, thin
film microstructure evolved from a porous columnar structure to a highly dense one. HfN thin films with different crystal structure and phases were obtained as a function of ICP power. The minimum resistivity of 125 µΩ-cm, the smoothest surface morphology with Ra roughness
of 5.9 nm were obtained for the HfN films deposited at ICP power of 200 W.