Degree Of Modification Research Articles

Linking river flow modification with wetland hydrological instability, habitat condition, and ecological responses.

Flow modification pursuing dams is widely found. Some works also focused on its impact on floodplain wetland hydrology. However, how this change can pose an impact on habitat conditions, ecological conditions, and trophic state is also a matter of investigation. The very least attention has been paid to this so far. Therefore, the present study focused on these, taking the dam-induced Lower Tangon river basin of India and Bangladesh as a case. The degree of flow alteration in the river was presented in a heat map. Multi-parametric machine learning (ML) approaches were applied to model hydrological instability and habitat condition. The ecological consequences like evaluating eco-deficit using flow duration curve (FDC) approach, trophic state using trophic state index (TSI), fish habitat zone using image-based hydrological parameters, etc. were measured. The study exhibited that after damming, the degree of river flow modification was about 41%. Consequently, the wetland hydrological instability and habitat conditions were degraded. In the post-dam period, > 50% of wetland area was lost, and hydrological instability was enhanced considerably over wider parts of the wetland. Habitat conditions of the existing wetland also witnessed fragility (poor and very poor areas increased by about 22.23 and 9.34%). As a result of this, adverse ecological responses were found. For instance, the eco-deficit area was increased by 36.19%, a good proportion (100%) of wetlands was witnessed the transformation of TSI from oligotrophic to mesotrophic state, and optimum fish habitat area was declined. The ecological strength map integrating all the cause-effect model parameters showed that good ecological strength was reduced from 49 to 2% in the post-dam. The result of the study would be very useful for wetland restoration for ecological and human well-being.

Self-Healable, Injectable Hydrogel with Enhanced Clotrimazole Solubilization as a Potential Therapeutic Platform for Gynecology.

Injectable, self-healing hydrogels with enhanced solubilization of hydrophobic drugs are urgently needed for antimicrobial intravaginal therapies. Here, we report the first hydrogel systems constructed of dynamic boronic esters cross-linking unimolecular micelles, which are a reservoir of antifungal hydrophobic drug molecules. The selective hydrophobization of hyperbranched polyglycidol with phenyl units in the core via ester or urethane bonds enabled the solubilization of clotrimazole, a water-insoluble drug of broad antifungal properties. The encapsulation efficiency of clotrimazole increases with the degree of the HbPGL core modification; however, the encapsulation is more favorable in the case of urethane derivatives. In addition, the rate of clotrimazole release was lower from HbPGL hydrophobized via urethane bonds than with ester linkages. In this work, we also revealed that the hydrophobization degree of HbPGL significantly influences the rheological properties of its hydrogels with poly(acrylamide-ran-2-acrylamidephenylboronic acid). The elastic strength of networks (GN) and the thermal stability of hydrogels increased along with the degree of HbPGL core hydrophobization. The degradation of the hydrogel constructed of the neat HbPGL was observed at approx. 40 °C, whereas the hydrogels constructed on HbPGL, where the monohydroxyl units were modified above 30 mol %, were stable above 50 °C. Moreover, the flow and self-healing ability of hydrogels were gradually decreased due to the reduced dynamics of macromolecules in the network as an effect of increased hydrophobicity. The changes in the rheological properties of hydrogels resulted from the engagement of phenyl units into the intermolecular hydrophobic interactions, which besides boronic esters constituted additional cross-links. This study demonstrates that the HbPGL core hydrophobized with phenyl units at 30 mol % degrees via urethane linkages is optimal in respect of the drug encapsulation efficiency and rheological properties including both self-healable and injectable behavior. This work is important because of a proper selection of a building component for the construction of a therapeutic hydrogel platform dedicated to the intravaginal delivery of hydrophobic drugs.

Features of modification of polyaminoamides with rosin-maleic adducts

The features of the process of chemical modification of polyaminoamides based on adipic acid and diethylenetriamine with rosin-maleic adducts differing in the content of maleopimaric acid (8.55; 16.46 and 31.12 % wt.) are considered. Modification of polyaminoamides with rosin-maleic adducts in the amount equal to the number of secondary amino groups in the repeating unit of the polymer was carried out in the melt at temperature 160–180 °C for 3 h under continuous stirring. The process was controlled by monitoring the change in the acid and amine numbers of the reaction mass. The most intensive modification of polyaminoamides by rosin-maleic adducts with different content of maleopimaric acid occurs within 1 h. It has been established that the rosin-maleic adduct with the 16.46 % wt. content of maleopimaric acid reacts with polyaminoamides and the degree of polymer modification reaches 57.39 %. The structure of the synthesized products was studied by IR-spectroscopy. The studied physicochemical properties (solubility, softening point, viscosity of solutions, acid and amine numbers, etc.) of the obtained products indicate that the reaction products are complex mixtures that consist of chemically modified polyaminoamides, N-substituted maleopimaric acid imides and unreacted rosin-maleic adducts (free resin and maleopimaric acids).

Security breaches and modifications on cybersecurity disclosures

Research Question: How do firms approach their cybersecurity disclosure obligations, especially for those who experienced a cyber-attack? Prior research has found that year-after-year modification on textual disclosures adds more appreciable information that makes it more relevant. But do firms provide meaningful disclosures to promote market transparency? Motivation: Because of growing cybersecurity threats in recent years, the U.S. Securities and Exchange Commission (SEC) has issued several regulations and guidance that emphasized on the disclosure of material information on cybersecurity. Given that the mandatory risk factor disclosures in SEC Form 10-K is the first place firms are encouraged to disclose cybersecurity-related assessment, it is important to examine how firms approach their disclosure expectations. Idea: To examine whether firms respond to cyber-attacks with meaningful disclosures, we use the Vector Space Model (VSM) to calculate disclosure modifications before and after major cyber-attack incident. Data: We extracted cybersecurity breach incidents from the Data Breach Database, a centralized and global database of data breaches maintained by a leading security company. In addition, we use the SEC data depository to find firms’ 10-K disclosures. Findings: We find that firms modify their cybersecurity disclosures by increasing the quantity of disclosures, but not necessarily the quality of disclosures as measured by document similarity. Furthermore, we find partial evidence that the degree of modification is positively associated with the severity of cyber-attacks. Contribution: Our evidence suggests that firms tend to use boilerplate language to disclose cybersecurity-related issues. This finding is consistent with prior research. That is, consistent with prior literature, the information content in public company 10-Ks is limited. We find that this seems to be the case as well when it comes to cybersecurity disclosures.

Material Properties and Cell Compatibility of Photo-Crosslinked Sericin Urethane Methacryloyl Hydrogel.

There is a need to develop novel cytocompatible hydrogels for cell encapsulation and delivery in regenerative medicine. The objective of this work was to synthesize isocyanato ethyl methacryloyl-functionalized sericin and determine its material properties as a natural hydrogel for the encapsulation and delivery of human mesenchymal stem cells (MSCs) in regenerative medicine. Sericin extracted from silk cocoons was reacted with 2-isocyanatoethyl methacrylate (IEM) or methacrylic anhydride (MA) to produce sericin urethane methacryloyl (SerAte-UM) or sericin methacryloyl (SerAte-M, control) biopolymers, respectively. The hydrogels produced by photo-crosslinking of the biopolymers in an aqueous solution were characterized with respect to gelation kinetics, microstructure, compressive modulus, water content, degradation, permeability, and viability of encapsulated cells. The secondary structure of citric acid-extracted sericin was not affected by functionalization with IEM or MA. SerAte-UM hydrogel was slightly more hydrophilic than SerAte-M. The gelation time of SerAte-UM hydrogel decreased with an increasing degree of modification. The photo-polymerized SerAte-UM hydrogel had a highly porous, fibrous, honeycomb microstructure with an average pore size in the 40–50 µm range. The compressive modulus, swelling ratio, and permeability of SerAte-UM hydrogel depended on the degree of modification of sericin, and the mass loss after 21 days of incubation in aqueous solution was <25%. Both SerAte-UM and SerAte-M hydrogels supported viability and growth in encapsulated MSCs. The SerAte-UM hydrogel, with its higher hydrophilicity compared to SerAte-M, is promising as a matrix for encapsulation and delivery of stem cells in tissue engineering.

An Artificial Intelligence Dataset for Solar Energy Locations in India

Rapid development of renewable energy sources, particularly solar photovoltaics (PV), is critical to mitigate climate change. As a result, India has set ambitious goals to install 500 gigawatts of solar energy capacity by 2030. Given the large footprint projected to meet renewables energy targets, the potential for land use conflicts over environmental values is high. To expedite development of solar energy, land use planners will need access to up-to-date and accurate geo-spatial information of PV infrastructure. In this work, we developed a spatially explicit machine learning model to map utility-scale solar projects across India using freely available satellite imagery with a mean accuracy of 92%. Our model predictions were validated by human experts to obtain a dataset of 1363 solar PV farms. Using this dataset, we measure the solar footprint across India and quantified the degree of landcover modification associated with the development of PV infrastructure. Our analysis indicates that over 74% of solar development In India was built on landcover types that have natural ecosystem preservation, or agricultural value.

A novel approach in increasing carboxymethylation reaction of cellulose

Carboxymethyl cellulose (CMC) with a high degree of substitution (DS) was prepared from hardwood bleached pulp by a novel method. In this method, pulp was refined in PFI mill and/or enzymatically treated prior to carboxymethylation. The DS value of CMC increased from 0.5 to 2.4. The yield and molecular weight of CMC increased with increasing DS value. The correlation coefficient between DS and molecular weight was 0.9992. Spectroscopic, thermogravimetric, x-ray diffraction and scanning electron microscopic (SEM) and titrimetric analyses were performed to confirm the degree of substitution and surface modification of the cellulose. Micrograph and SEM image confirm surface modification of cellulose in prior treatment. A comparison of the FTIR spectra of the prepared CMC and standard CMC shows the presence of bands corresponding to ˗O˗, CH2˗ and ˗COO in the CMC, while these bands do not appear for cellulose. The crystallinity of untreated pulp was slightly decreased, while the crystallinity of the prepared CMCs was diminished.

Modification of Keggin anion structure with ion beams—A new spectroscopic insights into the effects of keV‐ and MeV‐ion beam irradiation on 12‐tungstophosphoric acid

Ion beam irradiation is a versatile tool for structural modification and engineering of new materials. In this study, 12-tungstophosphoric acid (WPA) films of different thickness were spin-coated on platinized silicon substrate and irradiated with low energy hydrogen ions (10 keV) and swift heavy ions (Bi, Xe, and V) with energies up to 710 MeV. The different energy/fluence combinations allowed controllable structural changes that were investigated in detail using Raman and Infrared spectroscopy. For 120-nm-thick WPA samples, the irradiation led to the decrease of intensity of the skeletal and W-Oc-W bands of Keggin anion in order: Bi < V < Xe (for their applied energy/fluence combination). Also, symmetry change of Keggin anion similar to the one observed in the case of Keggin anions interacting with the supports was observed. For the selected ion beam irradiation parameters, xenon ion beam induced transformation of WPA to polytungstate. For 20-μm-thick WPA samples, the irradiation with hydrogen ion beam induced changes of skeletal vibrations and increased individualistic behavior of Keggin anions. As the fluence increased, the amount of the Keggin anions partially transformed to bronze also increased. Irradiation with vanadium also caused transformation to bronze-like structure but with higher ratio of terminal W=Od bonds. The overall results show clear correlation between degree of structural modification of WPA and the calculated displacement per atom value. These results open possibilities for engineering new catalytically active structures of polyoxometalates with the help of ion beams.

Response of natural, modified and artificial sandy beaches to sea-level rise

Sandy beaches occur in a wide variety of environmental settings and as components of a diverse range of coastal system types. These variations among beaches lead to significant differences in their mesoscale (multi-decadal, km length scale) behaviour, including their response to sea-level rise. In addition to this natural variability, the degree to which the sandy beach system has been or will be modified by humans is a major influence on how it responds to sea-level change. From a spectrum of beach types based on the degree of human modification, three situations (Natural, Modified and Artificial beaches) are considered in order to demonstrate the role of humans as geomorphic agents as sandy beaches respond to rising sea level. The potential trajectories of change are assessed, and future scenarios are presented and discussed. Natural beaches are most likely to survive sea-level rise, while the fate of artificial beaches depends almost entirely on the politics and economics of what lies immediately landward. In all categories of beach, human decision-making is the most important determinant of sandy beach response to sea-level rise.

The optimal way to fill the deficiency of essential substances for the well-being of the joints

The article presents basic information about the role and structure of cartilage tissue and its components, the impact of an imbalance in the structure of nutrition on the well-being of the joints, evidence of the symptomatic and structural-modifying effect of chondroitin and glucosamine in the composition of original drugs and dietary supplements in the treatment of osteoarthritis. Particular attention is paid to the structure and synthesis of collagen, its biological role in the body in the formation of the cell structure of various tissues, especially cartilage. Found 28 types of collagen, differing in amino acid sequence and degree of modification, which are encoded by more than 40 genes. It was noted that the activity of enzymes involved in the synthesis of collagen depends on sufficient intake of products containing ascorbic acid (vitamin C), and the degradation and decrease in the amount of collagen is associated with the development and progression of osteoarthritis and other diseases of the musculoskeletal system. The use of type 2 collagen, including in combination with chondroitin and glucosamine, is considered as a promising method for preventing joint problems. It is emphasized that the main substances necessary for the syn thesis of cartilage components come from food. An imbalance in the structure of nutrition (reducing the consumption of proteins, microelements and vitamins, excessive consumption of fats and carbohydrates) negatively affects the state of the connective tissue and causes problems for all structures that form the joint. One way to correct eating behavior and replenish essential deficiencies is through the use of vitamin-mineral complexes and dietary supplements, which are gaining interest in the medical community as evidence accumulates for their effectiveness in supporting joint well-being.

Molecular dynamics simulation for quantitative characterization of wettability transition on silica surface

Surfactant controlling the wettability of reservoir rocks is one of the important ways to enhance oil recovery in low-permeability tight reservoirs. A large number of scholars have developed a series of excellent wettability control reagents through macro physical simulation experiments, but macro experiments are difficult to analyze the micro mechanism of liquid/liquid and liquid/solid interface action of reagents controlling rock wettability. In this paper, the wetting behavior of water molecules on silica surfaces modified with different hydroxylation, methylation and hydrophobic chain length was studied by molecular dynamics simulation, and the quantitative relationship between different modification degrees and wetting angle was established. The results show that the original wetting angle of silica is 58.5°, and the surface wettability can be changed from hydrophilic to hydrophobic through surface modification, with a wetting angle of 27.25°∼115.78°. With the increase of the coverage of hydrophobic methyl or hydrophilic hydroxyl modified groups, the wetting angle increases or decreases respectively. The quantitative relationship between modification degree and wetting angle was established by simulated data. With the increasing of the chain length of methyl group, the distance between water molecule and silica surface increases and the interaction decreases, which can improve the regulation effect of methyl group hydrophobicity. This paper provides a reference basis for the synthesis of rock wettability control reagent and the quantitative characterization of modification degree.

Bio inspired based Multi-objective Data-Privacy-Preservation-Technique (MO-DPPT) system model for cloud data

The significance of data security in the cloud system has boosted the increasing quantity of sensitive and personal data being harvested by data controllers. As the cloud has more outsourced, unsecured sensitive data for public access, the data security for the cloud sectors is very important. The majority of state-of-the-art strategies fail to manage optimal privacy in implementing data privacy preservation model. To ensure data privacy preservation, most of the traditional techniques can perform the transformation on the actual data. These traditional methods are utilized limitedly, as they are pretty memory intensive and complicated. Hence, to defeat this dispute, this paper tries to develop a novel approach named Multi-Objective Data-Privacy-Preservation-Technique (MO-DPPT) that can look after the data privacy issues. The two main phases of the data privacy preservation model consist of the data sanitization and restoration process. Here, the optimal key generation is based on the proposed sanitization process and it is done by a novel meta-heuristic algorithm namely the Muddy Soil Fish Optimization Algorithm (MSFOA). The optimal key generation is achieved by developing the multi-objective function that focuses on the parameters of hiding ratio (HR) rate, Preservation Ratio (PR) rate, False Rule (FR) generation rate, and Degree of Modification (DM). Moreover, the proposed MSFOA algorithm has confirmed improved execution through statistical analysis, analysis on KPA and CPA attacks, and computational time analysis over the conventional algorithms. Finally, the proposed MSFOA based MO-DPPT system model using is compared with the existing traditional algorithms namely PSO, GWO, JA, SSO, JA-SSO, and the performance analysis of the proposed MSFOA based MO-DPPT system model has proven the superior efficiency in improving cloud security.

Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification.

BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification. 1H-/13C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization.

The glacial–terrestrial–fluvial pathway: A multiparametrical analysis of spatiotemporal dissolved organic matter variation in three catchments of Lake Nam Co, Tibetan Plateau

The Tibetan Plateau (TP) is a sensitive alpine environment of global importance, being Asia's water tower, featuring vast ice masses and comprising the world's largest alpine grasslands. Intensified land-use and pronounced global climate change have put pressure on the environment of the TP. We studied the tempo-spatial variability of dissolved organic matter (DOM) to better understand the fluxes of nutrients and energy from terrestrial to aquatic ecosystems in the TP. We used a multiparametrical approach, based on inorganic water chemistry, dissolved organic carbon (DOC) concentration, dissolved organic matter (DOM) characteristics (chromophoric DOM, fluorescence DOM and δ13C of DOM) in stream samples of three catchments of the Nam Co watershed and the lake itself. Satellite based plant cover estimates were used to link biogeochemical data to the structure and degradation of vegetation zones in the catchments. Catchment streams showed site-specific DOM signatures inherited from glaciers, wetlands, groundwater, and Kobresia pygmaea pastures. By comparing stream and lake samples, we found DOM processing and unification by loss of chromophoric DOM signatures and a change towards an autochthonous source of lake DOM. DOM diversity was largest in the headwaters of the catchments and heavily modified in terminal aquatic systems. Seasonality was characterized by a minor influence of freshet and by a very strong impact of the Indian summer monsoon on DOM composition, with more microbial DOM sources. The DOM of Lake Nam Co differed chemically from stream water samples, indicating the lake to be a quasi-marine environment in regards to the degree of chemical modification and sources of DOM. DOM proved to be a powerful marker to elucidate consequences of land use and climatic change on biogeochemical processes in High Asian alpine ecosystems.

Chemical and morphological characterization of self-etch primers incorporated with nanochitosan

This in vitro study evaluated experimental self-etch primers incorporated with different concentrations of nanochitosan gel (NC gel) and their action on the coronal and radicular dentin surface of bovine incisor teeth and the primer influence on the adhesive interface. Sections of 3 × 3 mm of coronal and root bovine dentin were flattened, and the smear layer was formed and standardized with 400 and 600-grit sandpaper. Root and coronal fragments (n=5) were treated with different primers: Clearfil™ SE Primer, Primer 1 – without NC gel, Primer 2–5% NC gel, Primer 3–10% NC gel, and Primer 4–15% NC gel. Primers were actively applied and left on the surface for 20 s. Images were acquired before treatment and immediately after primer application by confocal 3D laser scanning microscopy (x2160) to assess the degree of surface modification and dentinal tubule alteration. For adhesive interface analysis, dentin specimens (n=5) were treated with the evaluated primers, followed by the bond agent from Clearfil™ SE adhesive system, and restored with composite resin. Morphological analysis of the dentin surface and adhesive interface was performed using scanning electron microscopy (SEM) and chemical characterization using Fourier-transform infrared spectroscopy (FTIR). In coronal dentin, Clearfil™ SE Primer exposed fewer tubules than the experimental primers (p<0.05), and the percentage of open tubules was similar for all groups in root dentin (p>0.05). Primer 2 and Primer 3 showed higher values of perimeter and area for root dentin compared to the other groups (p<0.05), while Primer 1 was similar to Clearfil™ SE Primer (p>0.05). The incorporation of NC gel affected the behavior of the experimental primers. The addition of 10% of NC gel promoted a thicker and continuous hybrid layer with no gaps; however, higher concentrations of nanochitosan gel impaired the formation of a regular hybrid layer which is not favorable for an acceptable adhesion to the dentin substrate.

Polyamidoxime-based membranes for the rapid screening of uranium isotopes in water

Traditional radiochemistry approaches for the detection of trace-level alpha-emitting radioisotopes in water require lengthy offsite sample preparations and do not lend themselves to rapid quantification. Therefore, a novel platform is needed that combines onsite purification, concentration, and isotopic screening with a fieldable detection system. This contribution describes the synthesis and characterization of polyamidoxime membranes for isolation and concentration of uranium from aqueous matrices, including high-salinity seawater. The aim was to develop a field portable screening method for the rapid quantification of isotopic distribution by alpha spectroscopy. Membranes with varying degree of modification were prepared by chemical conversion of nitrile groups to amidoxime groups on the surface of polyacrylonitrile ultrafiltration (UFPAN) membranes. Attenuated total reflectance Fourier-transform infrared spectroscopy was used to analyze changes in surface chemistry. Flow through filtration experiments conducted using deionized (DI) water and simulated seawater solutions indicated that the modified membrane was effective in capturing more than 95% of the uranium in the solution prior to breakthrough even in the presence of salt ions. Batch uptake experiments were conducted and compared with the flow through experimental data to elucidate likely binding mechanisms. Alpha spectra of uranium loaded membranes were analyzed, and the effects of solution matrix and degree of modification on peak energy resolution were studied. Peak energy resolutions of 24 ± 2 keV and 32 ± 6 keV full width at half maximum (FWHM) were obtained by loading uranium from DI and seawater solutions onto modified membranes. Full width at 10% maximum of the same spectra were calculated to be 63 ± 9 keV and 160 ± 34 keV to quantify differences seen in peak tailing. Calculations performed based on the results show that it would take less than 3 h of analysis time to screen a sample provided enough volumes of solution are available. This work offers a facile method to prepare polyamidoxime-based membranes for uranium separation and concentration at circumneutral pH values, enabling the rapid, onsite screening of unknown samples.

New Directions in Aesthetic Medicine: A Novel and Hybrid Filler Based on Hyaluronic Acid and Lactose Modified Chitosan.

Fillers based on crosslinked hyaluronic acid (HA) are becoming increasingly important in the field of aesthetic medicine, for example for treating wrinkles or for volumizing purposes. However, crosslinking agents are usually associated with toxicity and adverse reactions. The aim of this study is the development of an innovative technology to manufacture high performance HA-based fillers using minimal amounts of crosslinking agent. In this work, new fillers based on HA, functionalized with different amounts of 1,4-butanediol diglycidyl ether (BDDE) (degree of modification ranging between 3.5% and 8.8%) and formulated with a lactose modified chitosan (CTL), were investigated. The relative quantities of these polymeric building blocks in the formulations were 20–25 and 5 mg/mL for HA and CTL, respectively. Due to its cationic nature, CTL could interact with the anionic HA and enhance the elastic properties of the filler. Fillers manufactured with this novel technology (HACL-CTL) were characterized and compared with several fillers available in the market. In particular, resistance against hyaluronidase, swelling, cohesivity and rheological properties were investigated. Cohesivity, resistance to hydrolysis and swelling of HACL-CTL were comparable to commercial products. However, HACL-CTL fillers showed excellent elastic performance that reached 94% of elasticity in response to shear stresses. Surprisingly, these fillers also showed a resistance to compression higher than that of currently marketed products, making them very promising for their lifting effect.

Identification of potential odorant markers to monitor the aroma formation in kilned specialty malts

Specialty malts are strategic ingredients regarding their contribution to colour and flavour of beer. Malts with the same colour may present distinct flavour characteristics and intensities. Contradictorily, colour is the benchmark in practical quality control. To investigate the correlation between colour and flavour of kilned barley specialty malts, odorants of commercial products of pale ale (5–9 EBC), Vienna (6–10 EBC), Munich (11–35 EBC) and melanoidin malts (80–90 EBC) were screened via solvent-assisted flavour evaporation (SAFE) and compared via comparative aroma extract dilution analysis (cAEDA). Subsequently, selected odorants were quantified using solid-phase microextraction (SPME). A total of 34 odorants were detected, of which 12 exhibited a concentration increase as the coloration increased, whereas 4 suggested the influence of temperature and modification degree on aroma formation. Such odorants are thus elected as potential markers for monitoring the influence of process variations on the formation of aroma in commercial kilned specialty malts.

Effect of oil modification on the multiscale structure and gelatinization properties of crosslinked starch and their relationship with the texture and microstructure of surimi/starch composite gels

This work investigated the multiscale structure and gelatinization properties of different oil-modified crosslinked starches and their relationship with the texture and microstructure of surimi/starch composite gels. The results showed clusters were formed by the agglomeration of starch, with oil on the surface of granules. Oil modification did not damage the long-range crystalline structure but impaired the short-range ordered structure. A high oil modification degree was shown to weaken starch structure, in contrast to an adverse effect for a high crosslinking level. Furthermore, compared with crosslinked starches, Oil-CTS had lower pasting temperature and gelatinization enthalpy, a higher viscosity, and better gel-reinforcing effect. Correlation analysis revealed the texture of surimi/starch composite gels was negatively correlated with the helical structure and pasting temperature of starch, and positively correlated with final and setback viscosity of starch and the swollen size of starch granules in surimi gel.

New relations between modification degree, swelling and impedance in anticorrosion chitosan-derivative coatings on magnesium alloy AZ31

Environmentally friendly coatings of chitosan-derivatives with natural aldehydes were investigated for corrosion protection of magnesium AZ31 alloy. The derivatives were characterized using FTIR and UV–Vis, and the swelling degree of their films was determined in 3.5 wt% NaCl solution. The coated samples were characterized using scanning electron microscopy, potentiodynamic polarization and electrochemical impedance spectroscopy. The results indicated that, as the modification degree increases, the corrosion current density and the swelling degree decrease, whereas the impedance modulus increases. For the first time it was proposed relations between |Z| and swelling with the modification degree.