Degree Of Modification Research Articles

Relating the prosody of infant-directed speech to children's vocabulary size.

This study examines correlations between the prosody of infant-directed speech (IDS) and children's vocabulary size. We collected longitudinal speech data and vocabulary information from Dutch mother-child dyads with children aged 18 (N = 49) and 24 (N = 27) months old. We took speech context into consideration and distinguished between prosody when mothers introduce familiar vs. unfamiliar words to their children. The results show that IDS mean pitch predicts children's vocabulary growth between 18 and 24 months. In addition, the degree of prosodic modification when mothers introduce unfamiliar words to their children correlates with children's vocabulary growth during this period. These findings suggest that the prosody of IDS, especially in word-learning contexts, may serve linguistic purposes.

Understanding Bitumen Aging through Interrelationships and Aging Ratios

Aging of bitumen can lead to fatigue and non-load-associated cracking of asphalt pavements. Performance grade specifications include threshold limits for rheological properties from specific ranges of binder behavior after laboratory aging. Some specifications include aging ratios (ARs) to limit the rate at which properties deteriorate. This study compares the evolution of interrelationships and ARs of performance parameters in specific areas in Black Space to understand the relative susceptibility of the binder behavioral spectra to aging. Unmodified and polymer modified binders are aged with the rolling thin film oven and pressure aging vessel, and tested with the dynamic shear and bending beam rheometers. It is seen in the study that there are both related and unrelated aging trends in the distinct stiffness-related ranges. Correlations in parameter development significantly improve when binders are grouped by similar features such as modification type or origin. Binder source and modification type and degree greatly dictate aging trends in the high-stiffness range. In the low-stiffness range, the initial hardness of the binder is indicative of aging potential. The evolution of properties may be influenced by either modification or binder source in the intermediate domain. When considering ARs for specifications, combining complementary ARs may provide reciprocal insights into binder aging.

In-depth characterization of 1,4-butanediol diglycidyl ether substituted hyaluronic acid hydrogels

BDDE substituted HA hydrogels remain the most commonly used HA product in the biomedical field. The physical and biochemical properties of the hydrogels are dependent on the degree of modification and substitution patterns/positions, thus, characterizing their fine structure is of great importance for quality assurance. In this study, we developed novel LC-MS methods for accurate determination of MoD as well as in-depth characterization of the linkage network. Fragments resulted from enzymatic depolymerization were resolved by a porous graphitic carbon column followed by online tandem-MS for determining the modification site/residue. With high-resolution separation, two types of previously unknown structures were detected in the cross-linked fragments of 2-B-2 and 4-B-2. Based on the feature of resistance to NaBH4 reduction, these structures contain a GlcNAc residue modified at OH1. This special sugar unit likely derived from reducing end of the native polysaccharide could be a signature to discriminate subtle batch to batch variations.

Dextran Formulations as Effective Delivery Systems of Therapeutic Agents.

Dextran is by far one of the most interesting non-toxic, bio-compatible macromolecules, an exopolysaccharide biosynthesized by lactic acid bacteria. It has been extensively used as a major component in many types of drug-delivery systems (DDS), which can be submitted to the next in-vivo testing stages, and may be proposed for clinical trials or pharmaceutical use approval. An important aspect to consider in order to maintain high DDS' biocompatibility is the use of dextran obtained by fermentation processes and with a minimum chemical modification degree. By performing chemical modifications, artefacts can appear in the dextran spatial structure that can lead to decreased biocompatibility or even cytotoxicity. The present review aims to systematize DDS depending on the dextran type used and the biologically active compounds transported, in order to obtain desired therapeutic effects. So far, pure dextran and modified dextran such as acetalated, oxidised, carboxymethyl, diethylaminoethyl-dextran and dextran sulphate sodium, were used to develop several DDSs: microspheres, microparticles, nanoparticles, nanodroplets, liposomes, micelles and nanomicelles, hydrogels, films, nanowires, bio-conjugates, medical adhesives and others. The DDS are critically presented by structures, biocompatibility, drugs loaded and therapeutic points of view in order to highlight future therapeutic perspectives.

Runoff regulation and nitrogen and phosphorus removal performance of a bioretention substrate with HDTMA-modified zeolite

As a commonly used material in bioretention substrates, natural zeolite (NZ) provides decent adsorption capacity for cation pollutants and heavy metals, but limited ability to remove anion pollutants. Hexadecyltrimethylammonium bromide (HDTMA)-modified zeolite (MZ) was used as the bioretention substrate material. The performance of the media including runoff reduction, nitrate nitrogen (NO3−-N) removal, ammonium nitrogen (NH4+-N) removal, and total phosphorus (TP) removal was assessed by the column experiment. The effects of different levels of modification, ratio of zeolite in the substrate, and rainfall intensity on media performance were investigated. The results indicate that HDTMA-modified zeolite significantly improves the NO3−-N (up to 38.2 times of NZ) and TP (up to17.5 times of NZ) removal rate of media and slightly increases the NH4+-N (up to 1.5 times of NZ) purification performance of the substrate. Compared with the media with NZ, decline on both runoff volume reduction (maximum decline up to 32.9%) and flow rate reduction (maximum decline up to 29.9%) of the media with MZ were observed. Based on multiple regression analysis, quantitative relationship models between influencing factors and response variables were established (R2 > 0.793), the level of the effect of influencing factors on response variables was investigated, and the interactions between influencing factors were explored. The main effect analysis found that the degree of modification affects NO3−-N and TP removal rate of the substrate the most, and when the amount of HDTMA molecules loaded on the zeolite surface exceeds 0.09meq/g, the modification can no longer improve NO3−-N removal efficiency.

Acoustic properties of aspen wood (Populus tremula),modified by ultrasonic method

Evaluation of the acoustic properties of objects using the obtained results as an informative parameter in determining the physical and mechanical characteristics of the material, as well as in the field of non-destructive testing, is widely used in modern science and technology. In the present paper the possibility of using this approach is considered in relation to the woodworking industry in order to estimate the characteristics of sawn timber modified by the ultrasonic method. The results of previous studies have shown the effectiveness of this technology for increasing the surface density and hardness of wood, therefore one of the urgent tasks is to find criteria that allow evaluating the achieved modification parameters, as well as optimizing the settings of the corresponding technological equipment.In this paper the research results of the acoustic properties of ultrasonic modified aspen wood (Populus Tremula) are represented and their applicability as a criterion for estimating the degree of modification for industrial wood blanks is revealed.

Construction of mouse cochlin mutants with different GAG-binding specificities and their use for immunohistochemistry.

Glycosaminoglycan (GAG) is a polysaccharide present on the cell surface as an extracellular matrix component, and is composed of repeating disaccharide units consisting of an amino sugar and uronic acid except in the case of the keratan sulfate. Sulfated GAGs, such as heparan sulfate, heparin, and chondroitin sulfate mediate signal transduction of growth factors, and their functions vary with the type and degree of sulfated modification. We have previously identified human and mouse cochlins as proteins that bind to sulfated GAGs. Here, we prepared a recombinant cochlin fused to human IgG-Fc or Protein A at the C-terminus as a detection and purification tag and investigated the ligand specificity of cochlin. We found that cochlin can be used as a specific probe for highly sulfated heparan sulfate and chondroitin sulfate E. We then used mutant analysis to identify the mechanism by which cochlin recognizes GAGs and developed a GAG detection system using cochlin. Interestingly, a mutant lacking the vWA2 domain bound to various types of GAGs. The N-terminal amino acid residues of cochlin contributed to its binding to heparin. Pathological specimens from human myocarditis patients were stained with a cochlin-Fc mutant. The results showed that both tryptase-positive and tryptase-negative mast cells were stained with this mutant. The identification of detailed modification patterns of GAGs is an important method to elucidate the molecular mechanisms of various diseases. The method developed for evaluating the expression of highly sulfated GAGs will help understand the biological and pathological importance of sulfated GAGs in the future.

Effects of oxidation degree of support and phosphorus modification on the catalytic cracking of coal pyrolysis tar by char-supported nickel catalysts

The low rank coal can be converted efficiently when it undergoes the pyrolysis process. The utilization of tar is modified and the problems such as pipeline blockage are solved by cracking and lightning heavy components in tar. In this study, the char-supported nickel (Ni) catalysts were prepared by different Ni loading methods, and the cracking of coal pyrolysis tar was improved by the coal char support with different oxidation degrees. The catalysts prepared by ion exchange method showed better performance for the tar cracking than other methods, which is related to their smaller Ni crystallite size (NCS). The oxidation of H2O2 and HNO3 significantly increased the number of oxygen-containing groups. The intrinsic correlation between oxidation degree of support and catalytic property indicated that the XH2O2-Ni/C (ZD coal pretreated by H2O2) series catalysts had better tar cracking activity than XHNO3-Ni/C (ZD coal pretreated by HNO3) series catalysts, which did not only depend on the increase of Ni loading amounts but also related to the smaller NCS and higher dispersion. Moreover, the non-metallic additive phosphorus (P) was added to modify the catalysts. It was found that the addition of P significantly improved the tar cracking performance of the 30%H2O2 P-Ni/C catalyst. The amounts of active components loaded and NCS contributed to the production of light tar.

Metal-organic framework (UiO-66 and UiO-66-NH2)-based adsorbents for bilirubin removal used in hemoperfusion.

Excessive accumulation of bilirubin in patients with hyperbilirubinemia can lead to tissue and organ damage and neurological diseases, and is even life-threatening in severe cases. Hemoperfusion is an effective method for removing bilirubin, but clinically used hemoperfusion adsorbents have unsatisfactory adsorption capacity and kinetics. In order to obtain a safe and efficient bilirubin adsorbent, Zr-based Metal-Organic Framework (MOF) material UiO-66 with high specific surface area and aqueous medium stability was prepared and modified with varying degrees of amination to improve its adsorption capacity. According to adsorption experiments in aqueous solution and simulated plasma, it was confirmed that the unsaturated coordinated zirconium in UiO-66 can effectively induce the aggregation and precipitation of free bilirubin unbound to albumin and the amino group on UiO-66-NH2 has a strong affinity for albumin bound bilirubin. The adsorption effect of UiO-66-NH2 with a high degree of amino modification is significantly stronger than that of UiO-66-NH2 with a low degree of modification. In simulated plasma with a bilirubin concentration of 40 mg dL-1, the adsorption capacities of UiO-66 and UiO-66-NH2-1.9 can reach 69.08 mg g-1 and 81.13 mg g-1. The adsorption isotherm fitting and adsorption kinetics fitting results also show that UiO-66 and UiO-66-NH2 are good adsorbents for bilirubin. In dynamic adsorption, the adsorbents also showed good performance and did not affect the protein in the plasma. The hemolysis test, coagulation time test, and cytotoxicity test confirmed that the bilirubin adsorbents based on UiO-66 and UiO-66-NH2 have good blood compatibility and biocompatibility. This study provides new ideas for the development of a novel bilirubin adsorbent and a theoretical basis for the study of bilirubin adsorption mechanisms.

Immobilization of isolated dimethyltin species on crystalline silicates through surface modification of layered octosilicate.

Single metal atoms supported on silica are attractive catalysts, and precise control of the local environment around the metal species is essential. Crystalline silica is useful as an efficient support for the incorporation of well-defined metal sites. Dimethyltin species were regularly grafted onto the layer surfaces of layered octosilicate, a type of two-dimensional (2D) crystalline silica. Dimethyltin dichlorides react with the surface silanol (SiOH) groups of the silicate layers. The formation of Si-O-Sn bonds was confirmed by 29Si magic-angle spinning (MAS) NMR. X-ray absorption fine structure (XAFS) analysis showed the four-coordinated Sn species. These results suggested the presence of well-defined dipodal dimethyltin species on the layer surfaces. The degree of modification of the silanol groups with the dimethyltin groups increased with increasing amounts of dimethyltin dichloride; however, the maximum degree of modification was approximately 50%. This value was interpreted as an alternate modification of the octosilicate reaction sites with dimethyltin groups. These results demonstrate the potential for developing highly active single metal catalysts with a high density of regularly arranged active sites on high surface area supports.

A Multi-Objective Bee Foraging Learning-Based Particle Swarm Optimization Algorithm for Enhancing the Security of Healthcare Data in Cloud System

Cloud computing is a potential platform transforming the health sector by allowing clinicians to monitor patients in real-time using sensor technologies. However, the users tend to transmit sensitive and classified medical data back and forth to cloud service providers for centralized processing and storage. This presents opportunities for hackers to steal data, intercept data in transit, and deprive patients and healthcare providers of private information. Consequently, Security and privacy are the primary concerns that must be addressed for the healthcare organization to trust and adopt the cloud computing platform. We present data sanitization and restoration processes to generate the keys from the acquired data and develop a multi-objective function for the hiding ratio, degree of modification, and information preservation ratio. We then employed the Bee-Foraging Learning-based Particle Swarm Optimization (BFL-PSO) algorithm to acquire the optimal key while transferring healthcare data into the cloud to ensure high Security. The experiment is carried out on the UHDDS dataset. The performance is assessed in terms of Security, delay time, encryption time, error rate, and convergence speed, with the results contrasted to state-of-the-art works. The performance study demonstrates that the suggested algorithm has higher Security than cutting-edge security algorithms.

Control of microphase-separated structures by tuning the functional groups and the degree of modification for a single block copolymer

To control the self-assembled morphology of block copolymers (BCPs), a series of BCPs were synthesized and post-functionalized via click chemistry.

Fizičke i mehaničke promene u termo modifikovanom drvetu - pregled

In Europe, wood is a crucial construction material that has experienced a surge in use for building applications in recent years. To enhance its dimensional stability and durability, thermal modification is a widely accepted commercial technology. Thermal modification is a popular technique that alters the properties of wood, improving its resistance to decay and increasing its dimensional stability. The process involves heating wood to high temperatures under controlled conditions, leading to chemical reactions that result in various physical and mechanical changes. This paper will discuss the effects of thermal modification on the physical properties of wood, such as density, moisture content, and color, as well as its impact on the mechanical properties, including strength, stiffness, and hardness. Additionally, the review will examine the factors that influence the degree of modification, such as temperature, duration, and wood species. Finally, the paper will conclude with an overview of the current state of research in this field and identify potential avenues for future investigation.

Ultrasound treatments of tef [Eragrostis tef (Zucc.) Trotter] flour rupture starch α-(1,4) bonds and fragment amylose with modification of gelatinization properties

Tef is a nutritionally-rich ancient grain gaining increasing interest in gluten-free market. Molecular and structural properties in the main biopolymers of two Spanish ecotypes of tef flour physically modified by ultrasound (US) treatments under different temperatures (20, 40, 45, 50 and 55 °C) were studied. Modifications achieved were dependent on tef ecotype, where white tef presented higher susceptibility. Size-exclusion chromatography indicated higher proportion of intermediate amylose chains (degree of polymerization 300–1600) across the whole amylose chain-length distribution and a higher amylose/amylopectin ratio, that increased up to 23% and 19% in treated samples of white and brown tef respectively. US increased the starch short-range order crystallinity and promoted the formation of random coil protein structure and the disappearance of β-sheet, as confirmed from FTIR spectroscopy. XRD and 1H NMR revealed a higher fragmentation of α-(1,4) than α-(1,6) bonds due ultrasonication. The gelatinization temperature range and ΔHgel decreased after ultrasonication up to 6 °C and 13%, an effect that was reinforced or counteracted, respectively, by the treatment temperature, indicating that annealing modulates the impact of sonication on flour gelatinization properties. Tef starch structural properties were found to be significantly modified by US treatments, where temperature was a determining variable influencing the degree of modification achieved.

Modification of the microstructure of tef [Eragrostis tef (Zucc.) Trotter] flour ultrasonicated at different temperatures. Impact on its techno-functional and rheological properties

Tef flour comes from a nutritionally-rich ancient grain gaining increasing interest in gluten-free market. Gluten-free sources are modified by different means to improve their functionality. Ultrasound treatment (US) alters flours' structure and leads to physically modified flours with a wider application range. The aim of the present work was to evaluate the impact of US treatments of moderate treatment time, 10 min, and high concentration of the aqueous flour dispersion, 25%, on the microstructural, starch damage, apparent amylose content, techno-functional, pasting and rheological properties of two tef flour varieties, white and brown. Temperature was varied (20, 40, 45, 50, and 55 °C) to modulate the impact of sonication. US treatments led to general particle fragmentation which markedly increased starch damage and lightness (L*) values. Apparent amylose content was higher after ultrasonication, as consequence of molecular fragmentation due to cavitation. Increased starch granules’ exposed area led to enhanced interaction with water, promoting the water absorption index (WAI) and swelling power (SP) of treated flours. Pasting properties showed increased pasting temperatures as well as decreased viscometric profiles with lower breakdown viscosities, indicative of starch rearrangement improved by increasing temperature. Rheological properties indicated higher consistency in gels after US treatments, with improved ability to withstand stress and lower values of tan(δ)1 reflecting a higher solid-like behavior and higher strength of the gel. Temperature was found to be a crucial variable during US treatments, showing an improved degree of modification at higher temperatures in ultrasonicated tef flours, following the same trend in both varieties.

Electron beam assisted recycling of polyurethane (PU) sponge: Turning it into a superabsorbent for wastewater treatment

AbstractPolyurethane (PU) sponge is being used on a large scale now‐a‐days, but that generates environmental pollution as it is not bio‐degradable. Moreover, the PU recycling existing techniques face several problems, which are being addressed sincerely throughout the world. Here, we report an easy, scalable, environment‐friendly, economic, and high throughput technique for converting scrap PU sponge into a superabsorbent for wastewater treatment. This is a new strategy for recycling scrap PU foam. This conversion follows the modification of surface energy of the PU sponge and generation of tiny‐scale roughness by a single‐step electron beam (EB) radiation‐assisted covalent attachment of dodecyl methacrylate (DMA) onto the waste PU sponge. The effect of degree of modification on the surface wettability is studied. Important process parameters namely, total dose, DMA concentration, solvent composition, and so forth are systematically varied and optimized to achieve the required extent of modification (~30 wt%). This desired degree of modification is achieved at 30 kGy total dose and in 15 vol% DMA concentration and 15 vol% water content in the reaction mixture. Grafting yield is measured gravimetrically and successful grafting is further confirmed by Fourier‐transform infrared spectroscopy, surface wettability, and surface morphology. The recycled PU shows superhydrophobicity with very high water contact angle (152°). Now, the recycled sponge can remove major liquid components of wastewater, namely, toxic organic solvents, oily liquids, nonpolar solvent soluble dyes from water media with high absorption capacity (25–30 g/g) successfully.

Study on Biodegradability and Mechanism of Cyanoethylated Waste Paper

With white pollution caused by petroleum plastics becoming an environmental issue of global concern, biodegradable plastics have become a research hotspot, and biodegradable materials made from plants have been attracting attention. Based on previous studies, this paper studied the biodegradability of thermoplastic cyanoethylated waste paper (CWP) by microbial experiment, and preliminarily explored the degradation mechanism. The results showed that: (1) the biodegradability of CWP was better than that of waste paper, and the higher the degree of modification, the better the biodegradability of CWP; under the action of Trichoderma reesei, the degradation rate of CWP containing 20.79% nitrogen was about 24% after 144 h (hours) of degradation; (2) The degradation rate of CWP was about 45% after 144 hours degradation by microbial complex bacteria, which was mainly due to the synergistic effect of cellulose degrading enzymes secreted by microbial degrading bacteria, which greatly improved the degradation rate of CWP. (3) The improvement of biodegradability of CWP was mainly due to the change of the morphology of the fibers by cyanoethylation reaction, which increased the contact surface and destroyed the crystal structure of the waste paper fibers. The increase of the amorphous region and the distance between the crystal planes was more conducive to the cellulase entering into the CWP, thus improving the degradation rate. (4) Structural analysis of CWP before and after degradation showed that microbial degradation bacteria destroyed C≡N bond and formed hydrocarbon bond, and further destroyed the crystal structure of CWP without changing the crystal form of the fiber.

Quantitative and convenient protocol for analysis of surface‐modified silica nanoparticles using 29Si‐NMR and near‐infrared diffuse reflection spectroscopy

Near‐infrared (NIR) diffuse reflection spectroscopy combined with solid‐state 29Si‐nuclear magnetic resonance (NMR) was applied to surface‐methylated silica nanoparticles for rapid determination of the degree of modification of silanol group. 29Si‐NMR with direct polarization method was employed to quantify the amounts of methyl and silanol groups from the areas of the T2, T3, Q2, and Q3 sites for referential samples modified with different amounts of trimethoxymethylsilane (TMMS). The degree of modification obtained by NMR was correlated with the corresponding NIR spectra by partial least squares (PLS) regression, where CH overtone and combination bands of the methyl group played a key role. Validity of the regression model was demonstrated for the mixtures of modified and unmodified samples at different ratios and for the samples prepared using excess amount of TMMS. This protocol will enable a high‐throughput characterization of surface‐modified silica nanoparticles used as a filler for polymer composites and a nucleating agent for polymer foams.

Enhancement of adsorption efficiency by surface modified Avocado seed for xylene removal

<p>The current study work's contribution relates to the removal of xylene using an adsorbent with modified surfaces made from a naturally occurring substance called avocado seed. With the aid of a muffle furnace heated to 600⁰c, this was converted to become activated carbon. Activated carbon is modified on the surface using titanium di oxide (Tio2). This surface modification demonstrated significant performance in the designated surface area of 67.35 m2 g-1. The varied levels of xylene concentration drop at three distinct temperatures 30, 60, and 90⁰C were visible. Applying the Thomas and Adams-Bohart to describe equilibrium adsorption data resulted in the model having the highest R2 values for describing equilibrium isotherm data. SEM patterns captured the degree of the surface modification with increased porosity; however, XRD and FTIR analyses of the surface modified adsorbent did not reveal any structural distortion. This thorough analysis resulted in the efficient removal of 93% of xylene by cost-effective adsorbent</p>

Facile preparation of hydrophobic Halloysite nanotubes (HNTs) for enhancement of organic solvent nanofiltration performance of polydimethylsiloxane (PDMS)-HNTs mixed matrix membrane

Depleting the alumina layer with acid treatment followed by a baking process was performed to generate Si-OH groups on HNTs. Facile hydrophobic modification with Trimethylsilyl chloride (TMCS) was carried out to generate organic nonpolar solvent dispersible HNTs. Baked hydrophobic modified HNTs embedded in polydimethylsiloxane (PDMS) and coated on the polyethersulfone (PES) support membrane ((PDMS/ BmHNTs) delivered an excellent OSN performance with a permeance of 3.75 L m−2 h−1 MPa−1 and 98.80% rejection in methanol/brilliant blue G (50 ppm) separation, which outperformed pristine PDMS, PDMS/RHNT, PDMS/nBmHNT membranes. The excellent performance of PDMS/ BmHNTs membranes was attributed to the high degree of modification which led to excellent interaction with the PDMS matrix.