DCC Method Research Articles

Push-Out Bond Strength of Fiber Posts to Overflared Root Canals in Different Root Regions: Effect of Reinforcement Techniques.

Objectives: This study aimed to investigate the effect of different reinforcement techniques on the push-out bond strength of fiber posts to over-flared root canals. Materials and Methods: Forty-eight extracted human single-canal premolars were endodontically treated, over-flared, and randomly divided into four groups (N=12) including SARC: luting with self-adhesive resin cement, DCC: luting with dual-cure core build-up resin composite, CRR: relining root canal walls with bulk-fill resin composite, and DAP: relining fiber post with bulk-fill resin composite. After 24 hours, the roots were sectioned to obtain three cervical, middle, and apical 3mm slices. The push-out test was performed and failure pattern was examined. Kruskal-Wallis and post-hoc Dunn-Bonferroni tests were used for statistical analysis (P<0.05). Results: In all three regions, the lowest and highest bond strength was found in the SARC and DAP groups, respectively. In the middle region, there was a statistically significant difference between the bond strength of the SARC group and that of the DCC (P=0.044), CRR (P=0.021), and DAP (P<0.001) groups. There was no significant difference in the apical region. The lowest bond strength was observed in the apical region, and the highest was related to the cervical region. Adhesive failure was the most common failure pattern in all groups. Conclusion: Based on our results DCC, CRR and DAP methods increased bond strength in the middle and cervical sections of over-flared root regions. Considering that DCC is the easiest and most practical method, we propose that CRR and DAP can be replaced with this method in clinical procedures.

A multivariate monitoring method based on kernel principal component analysis and dual control chart

The kernel principal component analysis (KPCA) method has been widely applied in process monitoring. However, the KPCA method still has two challenging problems that need to be solved: the principal component selection problem and the problem of determining Gaussian kernel width without fault data. The principal component selection plays an important role in the performance of the KPCA method, which is determined by the cumulative contribution rate, cross-validation, average eigenvalue, etc. However, these selection methods ignore the principal components corresponding to small eigenvalues, which are still very important for fault detection. Therefore, this paper proposes a multivariate monitoring method based on the KPCA and Dual Control Chart (KPCA-DCC), which adopts a scheme of monitoring all principal components and solves the selection problem. The Gaussian kernel width is usually determined by training an appropriate coefficient to times the variable number, which may not be possible to train the coefficient in the absence of fault data while the industrial process works at the initial stage of its operation. Furthermore, different systems may have the same number of variables, and their Gaussian kernel widths should vary because of different variables’ features. Therefore, this paper proposes an empirical equation for estimating Gaussian kernel width according to data characteristics, which makes the Gaussian kernel width can be estimated without fault data. In addition, this paper also gives the detection theory of the DCC method from the probability perspective, which is not presented in the previous work. The Tennessee Eastman (TE) process and blast furnace ironmaking process are adopted to verify the effectiveness of the proposed methods.

Modelling the joint dynamics of financial assets using MGARCH family models: Insights into hedging and diversification strategies

This study analyzes the conditional correlations and thereafter constructs the optimal portfolios for G-12 countries’ stock market returns and national benchmark bonds, crude oil, gold and the volatility index (VIX) returns. We use daily data ranging from January 1, 1994 to May 3, 2021 and compare the DCC, ADCC and GO-GARCH methods to investigate the past shocks and volatility transmissions. The rolling estimation techniques are employed to construct one-step-ahead forecasts of the dynamic conditional correlations and the optimal hedge ratios of G12 markets and other variables. For most of the situations studied, the volatility index (VIX) generates the best effective hedge to stock returns for these markets. The national benchmark bond indices create the second-best hedge. The risk and downside risk measures suggest that a sole stock exhibits the greatest risk and the expected maximum loss compared to a mixed bond-stock, a mixed VIX-stock, or a mixed gold-stock portfolio. The results are robust to alternative modeling specifications, model selection, as well as distributional assumptions.

Juvenile hormone mimics with phenyl ether and amide functionality to be insect growth regulators (IGRs): synthesis, characterization, computational and biological study

A series of substituted phenyl ethers derivatives as juvenile hormone (JH) mimics (V1-V8) have been synthesized. Substituted phenoxyacetic acid and amino acid ethyl ester hydrochloride were prepared using NaOH, SOCl2. DCC method has been used for amide linkage. The structure of prepared compounds has been confirmed by Fourier Transform Infra-Red (FT-IR), Electrospray ionization-Mass spectrometry (ESI-MS), Proton and Carbon-13 nuclear magnetic resonance (1H-NMR, 13C-NMR) spectroscopic techniques. Biological efficacy of synthesized analogs has been carried out under laboratory conditions. Galleria mellonella (honey bee pest) has been chosen as testing insect. Juvenile hormone (JH) activity of synthesized compounds has been tested at different concentrations and compared with the standard juvenile hormone analogs (JHAs) pyriproxyfen (M1) and fenoxycarb (M2) against the fifth larval instar of G. mellonella. Compound ethyl 2-[2-(4-methylphenoxy)aminoacetyl]-3-phenyl-propanoate (V6) exhibited better activity among all the synthesized compounds (V1-V8) with LC50 and LC90 values of 0.11 mg/mL and 0.56 mg/mL respectively. Compounds showed insect growth regulating (IGR) activity at lower concentrations. In silico screening of all synthesized compounds with the W-cavity of juvenile hormone-binding protein (JHBP) of insect G. mellonella has been carried out. Chemical reactivity of synthesized series has been studied using DFT/B3LYP/6-311 + G(d,2p) method. Non-toxic behavior of molecules has also been observed from ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) study using discovery studio client 3.0. Communicated by Ramaswamy H. Sarma

The Effects of Digital Concept Cartoons and Digital Concept Maps on Eliminating Middle School Students’ Misconceptions in the Mathematics Course: An Experimental Research

The purpose of this study was to investigate the effect of digital concept cartoons and maps in eliminating misconceptions of secondary school students. The research was conducted with 67 students who were studying at three different branches of 7th grade of secondary school. The research was conducted according to semi-experimental design with pre-test, post-test control group, and quantitative and qualitative research methods (mixed pattern) were used together. Accordingly, the mathematics classes in the Study Group I were conducted by the DCC method and the mathematics courses in the Study Group II were conducted by the DCM, and the mathematics courses in the control group were processed by traditional teaching method. In order to determine the students’ misconceptions before and after the experiment, Misconception Test was used which was applied as Pre-test and Post-test. In addition, students’ opinions and observation processes related to the use of DCC and DCM in mathematics class were included in the experimental process. As a result of the data analysis, there was no statistically significant difference between Study Group I, Study Group II and control group when the results of the Misconception test of the control and study groups were compared. In addition, students stated that the use of DCC and DCM in mathematics course have advantages such as making the courses enjoyable, drawing attention, increasing interest in the course, and visualizing the course topics. In the direction of the findings obtained from the research, various suggestions were made to the teachers and researchers about the use of DCC and DCM in secondary school mathematics courses.

On the Relationship of Cryptocurrency Price with US Stock and Gold Price Using Copula Models

This paper examines the relationship of the leading financial assets, Bitcoin, Gold, and S&amp;P 500 with GARCH-Dynamic Conditional Correlation (DCC), Nonlinear Asymmetric GARCH DCC (NA-DCC), Gaussian copula-based GARCH-DCC (GC-DCC), and Gaussian copula-based Nonlinear Asymmetric-DCC (GCNA-DCC). Under the high volatility financial situation such as the COVID-19 pandemic occurrence, there exist a computation difficulty to use the traditional DCC method to the selected cryptocurrencies. To solve this limitation, GC-DCC and GCNA-DCC are applied to investigate the time-varying relationship among Bitcoin, Gold, and S&amp;P 500. In terms of log-likelihood, we show that GC-DCC and GCNA-DCC are better models than DCC and NA-DCC to show relationship of Bitcoin with Gold and S&amp;P 500. We also consider the relationships among time-varying conditional correlation with Bitcoin volatility, and S&amp;P 500 volatility by a Gaussian Copula Marginal Regression (GCMR) model. The empirical findings show that S&amp;P 500 and Gold price are statistically significant to Bitcoin in terms of log-return and volatility.

Newly synthesized 3-(4-chloro-phenyl)-3-hydroxy-2,2-dimethyl-propionic acid methyl ester derivatives selectively inhibit the proliferation of colon cancer cells.

A series of 24 compounds were synthesized based on structure modification of the model methyl-3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropanoate as potent HDACIs. Saponification and hydrazinolysis of the model ester afforded the corresponding acid and hydrazide, respectively. The model ester was transformed into the corresponding trichloroacetimidate or acetate by the reaction with trichloroacetonitrile and acetic anhydride, respectively. N-Alkyl-3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropan-amides and methyl-2-[(3-(4-chlorophenyl)-3-hydroxy-2,2-dimethylpropanoyl)amino] alkanoates were obtained by the reaction of corresponding acid or hydrazide with amines and amino acid esters via DCC and azide coupling methods. Methyl-3-aryl-3-(4-chlorophenyl)-2,2-dimethylpropanoates were obtained in good yields and short reaction time from the corresponding trichloroacetimidate or acetate by the reaction with C-active nucleophiles in the presence of TMSOTf (0.1 eq.%) via C–C bond formation. The antiproliferative and apoptotic activity were further studied with molecular docking. The 48 post-treatments showed that out of 24 compounds, 12 compounds showed inhibitory actions on HCT-116 cells, we have calculated the inhibitory action (IC50) of these compounds on HCT-116 and we have found that the IC50 values were in between 0.12 mg mL−1 to 0.81 mg mL−1. The compounds (7a & 7g) showed highest inhibitory activity (0.12 mg mL−1), whereas compound 7d showed the lowest inhibitory activity (0.81 mg mL−1). We have also examined inhibitory action on normal and non-cancerous cells (HEK-293 cells) and confirmed that action of these compounds was specific to cancerous cells. The cancerous cells were also examined for nuclear disintegration through staining with DAPI, (4′,6-diamidino-2-phenylindole) is a blue-fluorescent DNA stain, and we have found that there was loss of DAPI staining in the compound treated cancerous cells. The compounds were found to potentially act through the HSP90 and TRAP1 mediated signaling pathway. Compounds 7a and 7g showed the highest selectivity to TRAP1 which explained its superior activity.

Direct coagulation casting of silicon carbide suspension via polyelectrolyte dispersant crosslink reaction

AbstractA direct coagulation casting method for silicon carbide ceramic suspension using dispersant crosslink reaction is reported. Polymer electrolyte (polyethyleneimine, PEI) was used as dispersant to prepare silicon carbide suspension. Common food additives (carboxymethyl cellulose, CMC) were used to coagulate the electrosteric stabilized silicon carbide suspension. There was a well disperse silicon carbide suspension with 0.2 wt% PEI at pH = 5‐6. Influence of coagulant on viscosity and zeta potential of the silicon carbide suspension was investigated. It indicates that the high solid loading silicon carbide suspension can be destabilized and coagulated at elevated temperature. It can be attribute to the gradual decrease of electrosteric force due to the crosslink reaction between PEI and CMC. Silicon carbide wet green body with compressive strength of 1.99 MPa could be demolded at 70°C which is higher than that prepared by traditional DCC and dispersant reaction method for nonoxide ceramics. Dense silicon carbide ceramics with relative density above 98.8% and 99.3% had been prepared by liquid phase pressureless and hot pressed sintering, respectively.

Decentralized coordinated control of elastic web winding systems without tension sensor

In elastic web winding systems, precise regulation of web tension in each span is critical to ensure final product quality, and to achieve low cost by reducing the occurrence of web break or fold. Generally, web winding systems use load cells or swing rolls as tension sensors, which add cost, reduce system reliability and increase the difficulty of control. In this paper, a decentralized coordinated control scheme with tension observers is designed for a three-motor web-winding system. First, two tension observers are proposed to estimate the unwinding and winding tension. The designed observers consider the essential dynamic, radius, and inertial variation effects and only require the modest computational effort. Then, using the estimated tensions as feedback signals, a robust decentralized coordinated controller is adopted to reduce the interaction between subsystems. Asymptotic stabilities of the observer error dynamics and the closed-loop winding systems are demonstrated via Lyapunov stability theory. The observer gains and the controller gains can be obtained by solving matrix inequalities. Finally, some simulations and experiments are performed on a paper winding setup to test the performance of the designed observers and the observer-base DCC method, respectively.

Activity standardization of 99mTc using liquid scintillation counting method

The Korea Research Institute of Standards and Science (KRISS) participated in the BIPM.RI(II)-K4.Tc-99 m comparison of activity measurements of 99mTc. We develop the national primary standard for 99mTc solution used during the comparison. We use two primary liquid scintillation counting techniques for the standardization: digital coincidence counting with the 4πβ(LS)-γ(NaI(T1))system and triple-to-double coincidence ratio counting. Both methods give consistent results for the specific activity of a 99mTc solution. Adopting the result from the DCC method as the reference value of the 99mTc measurement, we evaluate the standard uncertainty of 0.856% for the KRISS primary standard of the 99mTc activity. The K4 comparison result shows that the newly-established KRISS primary standard lies within the standard uncertainty with the key comparison reference value defined from other 99mTc measurements.

Preparation of Si3N4 foams by DCC method via dispersant reaction combined with protein-gelling

A novel forming method for preparing Si3N4 foams by DCC method via dispersant reaction combined with protein-gelling was proposed. Si3N4 foams were fabricated through temperature-induced hydrolysis of sodium tripolyphosphate (STPP) dispersant and simultaneous thermal gelling of ovalbumin binder at elevated temperature above 75 °C, with subsequent pressureless sintering at 1700 °C for 2 h. Stable Si3N4 suspension of 35 vol% solid loading with 0.5–2.0 wt% ovalbumin addition was obtained by adding 0.2 wt% STPP at alkaline region and room temperature. The controlled coagulation of the suspension could be realized after treating at 75 °C for around 1 h. Homogeneous composition distribution of Y and Al elements in EDS result indicated the uniform dispersion of sintering additives in green bodies, which was beneficial for the liquid phase sintering at high temperature. Typical spherical pore structure ranging from 110 to 320 μm formed due to the ovalbumin foaming capability and elongated β-Si3N4 crystalline grains generally over 3 μm were observed in sintered Si3N4 ceramic foams. Finally, Si3N4 ceramic foams with porosities ranging from 65.5 ± 1.5% to 80.8 ± 1.0% and compressive strength from 9.7 ± 0.9 MPa to 17.5 ± 1.2 MPa were obtained. The result indicated that the novel preparation approach in combination with DCC method and protein-gelling could be a convenient and environmentally friendly route to prepare various ceramic foams with high porosity and excellent material homogeneity.

REIT EN BRASIL: UNA OPORTUNIDAD DE DIVERSIFICACIÓN INTERNACIONAL

RESUMEN Los beneficios de la diversificación internacional se han visto modificados por el cambio continuo de las correlaciones entre los mercados. La inversión inmobiliaria presenta un elevado potencial como activo diversificador en un portafolio. El objetivo del presente trabajo es analizar la diversificación combinando la inversión en REIT con renta variable, para un inversor de Brasil. Para ello construimos carteras óptimas out-of-sample mediante predicciones de volatilidad, correlaciones y rendimientos utilizando los métodos DCC y VAR-DCC para el índice Ifix y los ETF BOVA11 y SPDR S&amp;P500, durante el período de 1 de diciembre de 2014 a 30 de octubre de 2015. Nuestros resultados muestran que la aproximación VAR-DCC mejora ligeramente las aproximaciones Plug-in y DCC, y la cartera Naïve.

Dynamical brain connectivity estimation using GARCH models: An application to personality neuroscience.

It has recently become evident that the functional connectome of the human brain is a dynamical entity whose time evolution carries important information underpinning physiological brain function as well as its disease-related aberrations. While simple sliding window approaches have had some success in estimating dynamical brain connectivity in a functional MRI (fMRI) context, these methods suffer from limitations related to the arbitrary choice of window length and limited time resolution. Recently, Generalized autoregressive conditional heteroscedastic (GARCH) models have been employed to generate dynamical covariance models which can be applied to fMRI. Here, we employ a GARCH-based method (dynamic conditional correlation - DCC) to estimate dynamical brain connectivity in the Human Connectome Project (HCP) dataset and study how the dynamic functional connectivity behaviors related to personality as described by the five-factor model. Openness, a trait related to curiosity and creativity, is the only trait associated with significant differences in the amount of time-variability (but not in absolute median connectivity) of several inter-network functional connections in the human brain. The DCC method offers a novel window to extract dynamical information which can aid in elucidating the neurophysiological underpinning of phenomena to which conventional static brain connectivity estimates are insensitive.

Conjugate and Directional Chaos Control Methods for Reliability Analysis of CNT–Reinforced Nanocomposite Beams under Buckling Forces; A Comparative Study

The efficiency and robustness of reliability methods are two important factors in the first-order reliability method (FORM). The conjugate choice control (CCC) and directional chaos control method (DCC) are developed to improve the robustness and efficiency of the FORM formula using the stability transformation method. In this paper, the CCC and DCC methods are applied for the reliability analysis of a nanocomposite beam as a complex engineering problem, which is reinforced by carbon nanotubes (CNTs) under buckling force. The probabilistic model for nanocomposite beam is developed through the buckling failure mode which is computed by using the Euler-Bernoulli beam model. The robustness and efficiency CCC and DCC are compared using the stable solution and a number of call limit state functions. The results demonstrate that the CCC method is more robust than the DCC in this case, while the DCC method is simpler than the CCC.

Synthesis and Solution Properties of PCL-b-PHPMA Diblock Copolymers Containing Stable Nitroxyl Radicals

This work focuses on the synthesis and the aqueous solution properties of novel amphiphilic PCL-b-PHPMA diblock copolymers possessing 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) stable radicals covalently conjugated to the hydrophobic poly(e-caprolactone) (PCL) block. A new synthetic approach (a four-step pathway) combining ring-opening polymerization (ROP), carbodiimide chemistry (DCC method), a reversible addition–fragmentation chain transfer (RAFT) polymerization technique, and finally chemical oxidation was employed to successfully produce a series of TEMPO-containing PCL-b-PHPMA diblock copolymers for the first time. EPR spectroscopy was applied to verify successful oxidation of the synthesized diblock copolymers and to investigate the dynamics of the polymer chains before and after micellization. The diblock copolymers self-assembled in PBS solution into spherical radical-containing nanoparticles (RNPs), which were characterized by 1H NMR spectroscopy, dynamic (DLS), static (SLS) light scattering, ...

An Empirical Study of Islamic Equity as a Better Alternative during Crisis Using Multivariate GARCH DCC

Risk Sharing is the core of the Islamic finance, the closest modern equivalent being equity investments. Through the decades of Islamic Finance development scholars have stressed on equity as the most beneficial financial mechanism while most accept modern joint-stock companies as quasi Mush rakah and Mu rabah forms, but this segment is still small in Islamic finance. Multitude of reasons contributes to it, primarily, the risk averseness and myth of equities as more risky alternate. This paper attempts to investigate this myth utilizing MGARCH DCC method, by studying the volatilities and correlations of Islamic indices over a period of twelve years. The findings are promising, suggesting a low moving correlation between the conventional and Islamic indices. The results substantiate the authors’ argument, that during crisis, Islamic indices provide though not complete, but partial insulation, thus a safer haven. This bodes well for a hugely untapped Islamic alternate investment avenue for exploration.

Properties of Alumina Coagulated Bodies Prepared by Direct Coagulation Casting via High Valence Counter Ions (DCC‐HVCI)

Alumina green bodies were prepared by direct coagulation casting via increasing high valence counter ions (DCC‐HVCI) method. Influence of calcium iodate concentration, coagulation temperature, and the solid loading on the compressive strength of coagulated bodies was investigated. The results show that the wet‐coagulated bodies display higher compressive strength than dried ones. The wet strength is above 2.0 MPa which is about one order higher than that prepared by DCC method, whereas the dried strength is in the range of 1.0 MPa. The wet‐coagulated body shows elastic deformation, whereas the dried body exhibits typical brittle failure behavior. The mechanism of high wet strength obtained by DCC‐HVCI is also proposed. The coagulated bodies prepared from slurries of alumina loading in the range of 50 vol% showed linear shrinkage of 2.6% after drying at 80°C for 24 h. The sample with the powder content of 50 vol% displays a narrow average pore channel size, showing a mean pore diameter of 40 nm. A homogeneous green body and high wet strength can be obtained via the DCC‐HVCI method.

Risk Management of QDII Fund Based on Dynamic Copula

In the paper, firstly, we fit the returns series with GARCH-EVT method, construct dynamic correlation coefficient matrix of elliptical copulas with DCC method, then analyze the dynamic dependency between stock index returns, finally calculate the CVaR of QDII funds through Monte Carlo simulation. Empirical study indicates that: while compared with dynamic Copula method, the static Copula model assuming the correlation between the assets is unchanged has overestimated the risk. CVaR value calculated by dynamic t Copula method is smaller than the one calculated via dynamic Gaussian Copula method. Accordingly, to optimize the investment portfolio, QDII fund manager should decrease the investment proportion in the developed market and emerging market while more money should be invested in Chinese A shares and the Hong Kong market.Kewords: QDII Fund; Dynamic Copula; CVaR

157 Clinicopathological implications of cyclin B1, cdc2, p16 and p53 expression in breast cancer

surgery from 1986 to 1995. Premenopausal women were treated with adjuvant ovarian ablation by irradiation and postmenopausal women with adjuvant Tamoxifen for 5 years. Steroid receptors contents were determined prospectively by the classical biochemical DCC method, while HER2 gene amplification was determined retrospectively by CISH in 134 women whose archival paraffin tissue samples were retrieved. Results: One hundred and thirty four patients whose HER2 status was determined (66 premenopausal and 68 postmenopausal) of median age of 51 years (range 35−76), were followed for median 11.8 years (range 0.9−19). Eleven (8.21%) patients were node negative with grade 3 BC and 125 (93.28%) had 1−3 positive nodes irrespective of tumor grade. Median disease free interval was 12.3 years (95%CI 10–17.8); median BC specific survival (BCSS) was 16.2 years (95%CI 13-Inf) and overall survival (OS) was 15.2 years (95%CI 12.1-Inf). HER2 gene amplification (CISH+) were noted in 21 (15.67%), while 113 (84.33%) had no HER2 gene amplification (CISH−). There was no significant difference in the risk for disease relapse [HR 1.25 (95%CI 0.678–2.29), p = 0.489], death from BC [HR 1.21 (95%CI (0.608–2.42), p = 0.591], and death from any cause [1.19 (0.637–2.23), p = 0.590] between CISH+ and CISH− subgroup. Cox regression analysis showed that only ER-/PgR+ status was an independent favorable risk factor for BCSS [HR 8.29 (95%CI 1.14–60.24, Wald test p = 0.028)] and OS [HR 7.51 (95%CI 1.31–68.97, Wald test p = 0.0009)]. Comparison between premenopausal and postmenopausal subgroups with CISH+ BC showed a trend toward longer OS in premenopausal women (Log rank test c1= 3.302, p = 0.069), while the OS difference in CISH− group reached statistical significance in premenopausal women (Log rank test c1= 4.849, p = 0.028). However, there was no difference in BCSS between premenopausal and postmenopausal subgroups regardless of HER2 status. Conclusion: Our results did not show that positive HER2 status had a significant influence on disease outcome in early SR-positive breast cancer patients treated with adjuvant endocrine therapy only.

NOVEL IMIDES AMINO ACIDS AND DIPEPTIDE DERIVATIVES

Some novel imides derivatives condensed with different amino acids using THF-Et3N method, afforded an excellent yield of compounds 3-8, 20-23b, 32-35b. some of these compounds react with CH3OH-SOCl2 mixture to give corresponding methyl esters 9-11, 24-25, 36-37 Hydrazinolysis of some methyl esters give hydrazides 12-14, 26-27 some dipeptides derivatives 15-17, 28-29, 38-40 were prepared using Dicyclohexylcarbodiimide DCC method, some spectra data were briefly discussed.