Effect Of Different Modifications Research Articles

The effect of the modified starch with side chain on the morphology of copper particles and the antibacterial properties of starch/copper composite material

In this paper, corn starch was modified by acetylation, esterification and amination, and the effects of different modifications on the structure and physicochemical properties of starch were investigated. And starch/copper composite materials were prepared by adding copper salts to the different modified starch, and the influence of modified starch and their additive amount on the morphology of copper and the antimicrobial properties were discussed. The results showed that: the contact angle of the modified starch was about 50° and exhibited hydrophilic-hydrophobic transition; the esterified starch had the smallest heat weight loss; the different modifications caused damage to the structure of the starch, which changed from the original smooth surface to a rough and wrinkled surface; hexahedral morphology copper particles were obtained by replacing them with the modified starch; the antimicrobial effect of the prepared starch/copper composite materials were related to the modification mode of starch, in which aminated starch show the best antimicrobial effect. This study provides a theoretical basis for the selection of starch type in the preparation of starch/copper composite materials in the future, which can also be used as antimicrobial components in other applications.

Substrate Modifications for Stability Improvements of Flexible Perovskite Solar Cells

Flexible perovskite solar cells (fPSCs) prepared on flexible plastic substrates exhibit poor stability under illumination in ambient, due to inferior gas barrier properties of plastic substrates. Herein, we investigated effect of different modifications of the back surface of the substrate to improve stability under illumination in ambient. T80 under simulated solar illumination at maximum power point in ambient (ISOS‐L‐1) can be increased from 80 h to over 350 h with the deposition of a single layer (by spin‐coating or by atomic layer deposition (ALD)). While ALD layers resulted in the best T80 value and significant reduction of the oxygen transmission rate compared to other modifications even for very low film thickness (≈10 nm), a simple solution‐processed spin‐on‐glass barrier layer also enables significant (more than 4 times) improvement in device stability. This work illustrates the importance of barrier layers for decreasing the ingress of oxygen and moisture into fPSCs through the plastic substrate.

Evaluating the impact of alternative phenotype definitions on incidence rates across a global data network.

Developing accurate phenotype definitions is critical in obtaining reliable and reproducible background rates in safety research. This study aims to illustrate the differences in background incidence rates by comparing definitions for a given outcome. We used 16 data sources to systematically generate and evaluate outcomes for 13 adverse events and their overall background rates. We examined the effect of different modifications (inpatient setting, standardization of code set, and code set changes) to the computable phenotype on background incidence rates. Rate ratios (RRs) of the incidence rates from each computable phenotype definition varied across outcomes, with inpatient restriction showing the highest variation from 1 to 11.93. Standardization of code set RRs ranges from 1 to 1.64, and code set changes range from 1 to 2.52. The modification that has the highest impact is requiring inpatient place of service, leading to at least a 2-fold higher incidence rate in the base definition. Standardization showed almost no change when using source code variations. The strength of the effect in the inpatient restriction is highly dependent on the outcome. Changing definitions from broad to narrow showed the most variability by age/gender/database across phenotypes and less than a 2-fold increase in rate compared to the base definition. Characterization of outcomes across a network of databases yields insights into sensitivity and specificity trade-offs when definitions are altered. Outcomes should be thoroughly evaluated prior to use for background rates for their plausibility for use across a global network.

ПОРІВНЯЛЬНИЙ АНАЛІЗ ЦИФРОВИХ ШУМІВ, ЗГЕНЕРОВАНИХ АДИТИВНИМИ ГЕНЕРАТОРАМИ ФІБОНАЧІ

Noise generators and pseudorandom number generators (PRNGs) are widely used in the field of information technology, including cybersecurity, for modeling, authorization key generation, and technical protection of information. It has been found that the characteristics of digital noise directly depend on the chosen PRNG algorithm. To determine the quality of the generated noise, special tests are performed, which are primarily applied to the sequence generated by the PRNG. The results of digital noise generated by an PRNG based on four different algorithms of additive Fibonacci generators (AFG) are investigated. The choice of generators of the same type allowed us to analyze the effect of different modifications on the final result of the generated sequences to determine their advantages and disadvantages. Digital signal processing techniques such as frequency, autocorrelation and visual analysis, signal-to-noise ratio, and statistical tests of the NIST package were used to test the noise and generated sequences. Functions for interpreting the obtained data were developed using the MATLAB (DSP System Toolbox) application package and the C programming language for automating NIST tests. It has been found that for effective testing, specific stages and their sequence should be determined: determination of the PRNG period, statistical tests of the NIST package, calculation of the autocorrelation function, and other methods of digital signal processing. It was found that modification of one AFG by using a carry bit (MAFG2) does not improve the results of the generated sequence, unlike the PIKE algorithm, which consists of three AFGs. The MAFG algorithm showed better results during the period testing and at the same time passed NIST tests, unlike the unmodified version. The dependence between the order of the generated sequences and the results of their autocorrelation function was revealed. It is proposed that, in addition to general statistical tests, applied tests should be carried out when choosing or developing a new generator, its effectiveness should be checked under the conditions required by existing standards and requirements. The compliance of the generated digital noise with the requirements for devices for technical protection of information, namely the protection of speech information, has been established.

Desaturation of the Sphingofungin Polyketide Tail Results in Increased Serine Palmitoyltransferase Inhibition.

ABSTRACTSerine palmitoyltransferase catalyzes the first step of the sphingolipid biosynthesis. Recently, sphingolipid homeostasis has been connected to several human diseases, making serine palmitoyltransferases an interesting therapeutic target. Known and efficient serine palmitoyltransferase-inhibitors are sphingofungins, a group of natural products isolated from fungi. To further characterize newly isolated sphingofungins, we designed an easy to use colorimetric serine palmitoyltransferase activity assay using FadD, which can be performed in 96-well plates. Because sphingofungins exert antifungal activitiy as well, we compared the in vitro assay results with an in vivo growth assay using Saccharomyces cerevisiae. The reported experiments showed differences among the assayed sphingofungins, highlighting an increase of activity based on the saturation levels of the polyketide tail.IMPORTANCE Targeting the cellular sphingolipid metabolism is often discussed as a potential approach to treat associated human diseases such as cancer and Alzheimer's disease. Alternatively, it is also a possible target for the development of antifungal compounds, which are direly needed. A central role is played by the serine palmitoyltransferase, which catalyzes the initial and rate limiting step of sphingolipid de novo synthesis and, as such, the development of inhibitory compounds for this enzyme is of interest. Our work here established an alternative approach for determining the activity of serine palmitoyltransferase adding another tool for the validation of its inhibition. We also determined the effect of different modifications to sphingofungins on their inhibitory activity against serine palmitoyltransferase, revealing important differences on said activity against enzymes of bacterial and fungal origin.

In-situ quantification of manufacturing-induced strains in fiber metal laminates with strain gages

The predominant use of FBG sensors to characterize the residual stress state in composite materials to date does not permit absolute strain measurements. The reason for this is the loss of the connection between the sensor and laminate during phase transitions of the resin. Thus, points of significant changes in the measurement signal (e.g. bonding temperature) need to be used for the residual stress evaluation. For fiber metal laminates (FML) however, strain gages applied to the metal layer allow absolute strain measurements since the metal behaves purely elastic over the entire manufacturing process. Hence, residual stresses in the metal layer of an FML are quantified directly. Despite the sensors being applied to the metal layer, it is shown that the cure state of the resin can still be analyzed by changes in the coefficient of thermal expansion. Thus, the effects of different modifications to the cure cycle are assessed in terms of residual stress reduction. It is shown that assuming the bonding temperature to be equal to the stress-free temperature results in a conservative estimation of the residual stress state. The strain gage signal is shown to be in good agreement with FBG sensor data during a combined experiment.

Effect of Different Modifications (Physical and Chemical) on Morphological, Pasting, and Rheological Properties of Black Rice (Oryza sativa L. Indica) Starch: A Comparative Study

AbstractThe demand for black rice has increased rapidly in the past years because of the distinctive color, characteristic flavor, nutritional value, and health benefits. This study aims to investigate the chemical and physical modifications on morphology, pasting, thermal, and rheological properties of black rice starch. The highest swelling power is observed for octenyl succinic anhydride modified black rice starch whereas gamma irradiated rice starch shows the lowest value. Rheometer analysis shows that physical and chemical modifications generally alter the pasting characteristics of starches which may be attributed to the excessive degradation of starch granules. Native black rice starch granules are of small size and irregular in shapes with sharp angles and edges. After modifications, rice starch granules surface lose natural morphology. All native and modified rice starch exhibit the typical A‐type X‐ray patterns of cereal starches. Results of present study provides a better understanding of functional properties of native and modified black rice starches for their possible applications in food products.

Digestion behavior and gastrointestinal fate of oil-in-water emulsions stabilized by different modified rice starches.

Native rice starch was modified using different methods which included debranching (DB), octenyl succinylation (OSA), debranching followed by octenyl succinylation (DBOS) and octenyl succinylation followed by debranching (OSDB). The effect of different modifications and the impact of modified starch properties (resistant starch content (RS) and degree of substitution (DS)) on the gastrointestinal fate of emulsified lipids are elucidated using an in vitro digestion model that included the mouth, stomach, and small intestine phases in order to understand their functionality for further applications. The effect of the different modified rice starches on the particle size distribution of the lipid droplets, surface charge (ζ-potential), microstructure, lipid digestion (free fatty acid (FFA) release), and starch hydrolysis was also assessed. The OSA-modified starch and DBOS starch-based emulsions were found stable during the mouth phase and were also found to demonstrate lesser flocculation and coalescence in comparison with the other emulsions due to the presence of more OSA groups that provide greater steric hindrance and better protection from the gastrointestinal conditions. Furthermore, the DBOS starch was found to form emulsions that were more resistant to digestion with a degree of FFA release like dietary fibers and a lower extent of starch digestion that can be attributed to their higher resistant starch content (RS). Thus, the DBOS starch-based emulsions were found to be suitable for further applications such as developing functional foods to control satiety or for designing delivery systems for the sustained release of bioactive compounds.

Structural Evolutionary Learning for Composite Classification Models

Abstract In this paper, we propose an evolutionary learning approach for flexible identification of custom composite models for classification problems. To solve this problem in an efficient way, the problem-specific evolutionary operators are proposed and the effectiveness of different modifications of the common genetic programming algorithm is investigated. Also, several implementations of caching for the fitted models were compared from the performance point of view. To verify the proposed algorithm, both synthetic and real-world classification cases are examined. The implemented solution can identify the structure of the composite models from scratch, as well as be used as a part of automated machine learning solutions.

In Vitro Digestibility and Thermal Properties of Native and Modified Sago (Metroxylon Sagu) Starch

In recent years, there is growing interest in the nutritional implications of resistant starch in foods due to its functional properties and health benefits. This has resulted to the development of various modification techniques to induce the formation of resistant starch. This study aimed to elucidate the effect of different modifications on digestibility and thermal properties of sago starch. Sago starch was treated with hydrothermal treatment [heat moisture treatment (HMT) and annealing (ANN)] as well as combined modification of acid methanol treatment (AMT) and hydrothermal treatment (HMT and ANN), respectively. Combined modification (AMT-HMT and AMT-ANN) had more pronounced effect in increasing the resistant starch (RS) content and lowering the glycemic index (GI) of sago starch, especially in gelatinized form. Strong negative correlation was obtained between RS and GI in both raw and gelatinised starch. Combination of acid methanol treatment with annealing caused the highest increment in gelatinization temperatures of sago starch.

Lignin Based Functional Additives for Natural Rubber

In this work, the possibility to conveniently exploit lignin as a functional additive for natural rubber was pursued following two strategies. The first was based on the fractionation of lignin: extraction with organic solvents is suitable to produce lignin fractions with better defined structural features, molecular weight distributions, and physicochemical properties. The second approach was based on the chemical modification of lignin in the attempt to overcome its poor affinity with the rubber: esterification with anhydrides was selected to modify relatively large samples of lignin at laboratory scale. The effectiveness of different modifications of lignin as a drop-in replacement for carbon black was evaluated analyzing the tensile mechanical properties of model elastomeric compounds. In addition, the behavior of the modified lignins was rationalized through Hansen solubility parameters predicted with the group-contribution method.

Fetal head size and effect of manual perineal protection.

ObjectiveThe aim of this study was to evaluate whether a previously identified modification of Viennese method of perineal protection remains most effective for reduction of perineal tension in cases with substantially smaller or larger fetal heads.MethodsA previously designed finite element model was used to compare perineal tension of different modifications of the Viennese method of perineal protection to "hands-off" technique for three different sizes of the fetal head. Quantity and extent of tension throughout the perineal body during vaginal delivery at the time when the suboccipito-bregmatic circumference passes between the fourchette and the lower margin of the pubis was determined.ResultsThe order of effectiveness of different modifications of manual perineal protection was similar for all three sizes of fetal head. The reduction of perineal tension was most significant in delivery simulations with larger heads. The final position of fingers 2cm anteriorly from the fourchette (y = +2) consistently remains most effective in reducing the tension. The extent of finger movement along the anterior-posterior (y-axis) contributes to the effectiveness of manual perineal protection.ConclusionAppropriately performed Viennese manual perineal protection seems to reduce the perineal tension regardless of the fetal head size, and thus the method seems to be applicable to reduce risk of perineal trauma for all parturients.

Effects of carbonated liquid on swallowing dysfunction in dementia with Lewy bodies and Parkinson's disease dementia.

BackgroundSwallowing dysfunction is an increasingly recognized problem in patients with dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD), which can result in aspiration pneumonia and death. Few studies have examined potential ways of improving swallowing function in this fragile patient group. The aim of this study was to evaluate swallowing dysfunction and carbonated liquid using videofluoroscopy in DLB and PDD patients.MethodsA total of 48 patients with DLB and PDD were referred for a clinical examination with videofluoroscopy. Descriptive overall assessments were provided at the time of the examination regarding swallowing function and the effects of different modifications, including carbonated thin liquid (CTL). Additionally, a repeated measures quantitative retrospective analysis has been performed comparing 1) thin liquids; 2) thickened liquids and 3) CTLs, with regard to the quantitative variables 1) pharyngeal transit time (PTT); 2) pharyngeal retention and 3) tracheal penetration.ResultsIn all, 40/48 (83%) of the patients had a swallowing dysfunction, which was confirmed on videofluoroscopy, with 34/40 (85%) patients having a pharyngeal-type dysfunction. A total of 14/40 (35%) patients with an objective swallowing impairment did not have any subjective swallowing symptoms. Out of the patients with swallowing dysfunction, 87% had an overall improved swallowing function with carbonated liquid. PTT for carbonated liquid (median 633 ms, interquartile range [IQR] 516–786 ms) was quicker than for thin liquid (760 ms, IQR 613–940 ms, P=0.014) and thickened liquid (880.0 ms, IQR 600–1,500 ms, P<0.001). No significant effect was seen in residue or penetration.ConclusionThe majority of patients with DLB or PDD had a swallowing dysfunction, sometimes without subjective swallowing symptoms, which improved with carbonated liquid. This highlights the importance of investigating patients with videofluoroscopy and to carry out a prospective interventional study to further evaluate carbonated liquid, also addressing the effects on quality of life, aspiration and mortality.

Implementation issues and benchmarking of lattice Boltzmann method for moving rigid particle simulations in a viscous flow

In this work, we revisit implementation issues in the lattice Boltzmann method (LBM) concerning moving rigid solid particles suspended a viscous fluid. Three aspects relevant to the interaction between flow of a viscous fluid and moving solid boundaries are considered. First, the popular interpolated bounce back scheme is examined both theoretically and numerically. It is important to recognize that even though significant efforts had previously been devoted to the performance, especially the accuracy, of different interpolated bounce back schemes for a fixed boundary, there were relatively few studies focusing on moving solid surfaces. In this study, different interpolated bounce back schemes are compared theoretically for a moving boundary. Then, several benchmark cases are presented to show their actual performance in numerical simulations. Second, we examine different implementations of the momentum exchange method to calculate hydrodynamic force and torque acting on a moving surface. The momentum exchange method is well established for fixed solid boundaries, however, for moving solid boundaries there are still open issues such as unphysical force fluctuations and Galilean invariance errors. Recent progress in this direction is discussed, along with our own interpretations and modifications. Several benchmark cases, including a particle-laden turbulent channel flow, are used to demonstrate the effects of different modifications on the accuracy and physical results under different physical configurations. The third aspect is the refilling scheme for constructing the unknown distribution functions for the new fluid nodes that emerge from the previous solid region as a particle moves relative to a fixed lattice grid. We examine and compare the performance of the refilling schemes introduced by Fang et al. (2002), Lallemand and Luo (2003), and Caiazzo (2008). We demonstrate that improvements can be made to suppress force fluctuations resulting from refilling.

Numerical and Experimental Study on the Tonal Noise Generation of a Radial Fan

The main focus of this work is on the geometrical modifications can be made to the fan wheel and to the volute tongue of a radial fan to reduce the tonal noise. The experimental measurements are performed by using the in-duct method in accordance with ISO 5136. In addition to the experimental measurements, CFD (computational fluid dynamics) and CAA (computational aeroacoustics) simulations are carried out to investigate the effects of different modifications on noise and performance of the fan. It is shown that by modifying the blade outlet angle, the tonal noise of the fan can be reduced without impairing its aerodynamic performance. Moreover, it is indicated that increasing the number of blades leads to a significant reduction in the tonal noise and also an improvement in the aerodynamic performance. However, this trend is only valid up to a certain number of blades, and a further increment might reduce the aerodynamic performance of the fan. Besides modifying the impeller geometry, new volute tongues are designed and tested on the rig. It is demonstrated that the shape of the volute tongue plays an important role in the tonal noise generation of the fan. Moreover, in order to find out whether or not it is possible to reduce the tonal noise level through a destructive phase-shift generation, stepped tongues are comprehensively investigated by means of numerical simulations and experimental measurements.

The six conserved serine/threonine sites of REPRESSOR OF ga1-3 protein are important for its functionality and stability in gibberellin signaling in Arabidopsis.

Our results provide further insight into the regulation of DELLA proteins in Arabidopsis . We clarified that phosphorylation modification of the six conserved sites is important for RGA functions and stability. The DELLA proteins, important plant growth and development repressors mediate the gibberellin (GA) signaling pathway. Although these proteins exhibit phosphorylation and de-phosphorylation states at the molecular level, little is known regarding the effects of different modifications of DELLA proteins on the regulation of their bioactivity and stability at the genetic level. In this study, six conserved serine (Ser)/threonine (Thr) sites of REPRESSOR OF ga1-3 (RGA) were substituted with alanine (RGA6A) or aspartic acid (RGA6D) to mimic the states of constitutive de-phosphorylation and phosphorylation, respectively. We found that the overexpression of de-phosphomimic RGA in Col-0 plants caused GA-overdose phenotypes, which were similar to DELLA-deficient mutant. These phenotypes were probably attributed to de-phosphomimic RGA, which retained its transcriptional activation activity that induces GA biosynthetic genes, but lost the transcription repressor function that inhibits GA-responsive genes. Further, de-phosphomimic RGA was unstable and easily degradable unlike the wild-type RGA, suggesting that the de-phosphorylated form is necessary for its degradation. In contrast, phosphomimic RGA overexpression caused GA-deficient phenotypes with non-degradable RGA. These phenotypes were probably due to phosphomimic RGA, which represses GA-responsive gene expression instead of inducing GA biosynthetic genes. In addition, phosphomimic RGA was stable and hardly degradable, which aggravated the RGA-inhibiting function in GA signaling. In conclusion, we show that the six conserved Ser/Thr sites are important for the different bioactivities of the RGA protein that regulate the GA response, and also for RGA stability via the mimicking of phosphorylation/de-phosphorylation.

Insights on pregnane-X-receptor modulation. Natural and semisynthetic steroids from Theonella marine sponges

Pregnane-X-receptor (PXR) is a member of nuclear receptors superfamily that activates gene transcription by binding to responsive elements in the promoter of target genes. PXR is a master gene orchestrating the expression/activity of genes involved in the metabolism of endobiotics including bilirubin, bile acids, glucose and lipid. In addition PXR oversights the metabolism of the large majority of xenobiotics including a large amount of prescribing drugs. Thus, developing PXR ligands represents a great opportunity for a therapeutic intervention on human diseases including diabetes, obesity, dyslipidemias and liver disorders. To this end, natural compounds represent an arsenal of new chemical scaffolds useful for the identification of novel PXR ligands. Here, we report a series of 4-methylenesteroid derivatives isolated from Theonella marine sponges as novel PXR modulators. In addition, combining medicinal chemistry, pharmacological experiments and computational studies, we have investigated the effects of different modifications on ring A and on the side chain of 4-methylenesteroid derivatives toward PXR modulation. This study provides the molecular bases of ligand/PXR interaction useful for designing novel PXR modulators.

Effect of different modifications of BEA-zeolites on operational characteristics of conductometric biosensor

Effect of different modifications of zeolite Na+-BEA on working characteristics of urease-based conductometric biosensor was studied. As the biosensor sensitive elements were used bioselective membranes based on urease and various zeolites immobilised with bovine serum albumin on the surface of conductometric transducers. Influence of zeolites on sensitivity of urea biosensor was investigated as well as reproducibility of biosensor signal and reproducibility of activity of the bioselective element after different variants of urease immobilisation on the surface of conductometric transducer. The biosensors based on zeolites (NH4+-BEA 30 and H+-BEA 30) were shown to be the most sensitive. Concentration of these zeolites in the bioselective membrane was optimized. Use of zeolites modified with methyl viologen and silver was ascertained to be of no prospect for urea conductometric biosensors. It was demonstrated that characteristics of urea biosensors can be regulated, varying zeolites modifications and their concentrations in bioselective membranes.

Modified alumina as catalyst support for cobalt in the Fischer–Tropsch synthesis

The effect of different modifications (Zn, Mg, Ni, Re) has been studied for alumina-supported 12 wt% Co-catalysts in the Fischer–Tropsch synthesis (FTS) using a fixed-bed reactor at 483 K, 20 bar, and H 2/CO = 2. Different parameters including calcination temperature, loading, impregnation sequence, and water partial pressure during FTS have been studied. When compared to low surface area α-Al 2O 3, mechanical strength was substantially improved for Ni- and Mg-modified aluminas calcined at very high temperatures (>1400 K), thus making them more suitable for slurry or fluidized-bed operation. However, Mg was found to have a loading-dependent negative effect on both activity and selectivity. The wt% effect was stronger when co-impregnated with Co–Re and calcined at 773 K, than when impregnated on the support and calcined at a high temperature (1173 K) prior to impregnation with Co–Re. Co-impregnating Co–Re with Zn also had a strong loading-dependent negative effect on activity and selectivity, while impregnating Zn on the support and calcining at a high temperature (1173 K) prior to impregnation with Co–Re had no negative effect on the overall C 5+ yield. The negative effects of Mg and Zn could not be explained by dispersion or particle size effects and were likely related to a chemical/site effect similar to that of alkalies reported on in the literature. The effect of water for the Ni-modified support was in accordance with the literature, improving reaction rates and C 5+ selectivity, while inhibiting olefin hydrogenation, as demonstrated by the propene/propane ratio. The catalysts were characterized with H 2 chemisorption, N 2 sorption, mercury intrusion, X-ray diffraction, temperature-programmed reduction, and O 2 titration.

Controlled ovarian hyperstimulation for low responders in in vitro fertilization/intracytoplasmic sperm injection: a low-dose flare protocol

In this retrospective study of 652 anticipated low response women, the overall clinical outcomes (live birth rate and clinical pregnancy rate [PR]) of low-dose flare (LDF) protocol appeared lower than those of conventional down-regulation (DR) (LDF: 15.1% vs. DR: 20.6% and LDF: 10.3% vs. DR: 17.4%, respectively). The findings that LDF protocol improved the clinical outcome in older women, or when LDF followed an unsuccessful IVF/intracytoplasmic sperm injection (ICSI) cycle with DR (LDF: 19.4% vs. DR: 9.76% and LDF: 13.9% vs. DR: 4.2% respectively), need further evaluation through randomized trials.