Composition Of Macromolecules Research Articles

Construction of macromolecular structure model of Luling coal and study on the dynamic mechanism of micro-wetting process

The physicochemical structure and energy composition of coal macromolecules are the major factors affecting coal wettability. This study thus employed 13C NMR, FTIR, and XPS to determine the chemical structure of coal in the No. 10 coal seam of the Luling coal mine and gain insights into the molecular mechanisms of coal wetting. The results showed that the molecular formula of the Luling 10 model was C290H223O25N5S. Through molecular dynamics simulation, upon the stable adsorption of sodium dodecyl sulfate (SDS) on the coal surface, both the mobility of water molecules and the water molecule content in the interfacial adsorption layer increased. After SDS was added, except for the hydrogen bond energy, the increase rate of each potential energy increased, and van der Waals energy and bond length energy changed the most. The reason for the decrease of hydrogen bond energy is that more atoms in coal macromolecules form hydrogen bonds with polar water molecules. The increase of SDS promoted the significant changes of bond length energy, bond angle energy and van der Waals force of coal, thus increasing the wettability of coal. Taken together, our findings provide important insights into the molecular mechanisms through which surfactants improve chemical wetting.

Molecular-mass distribution of alkylphenolformaldehyde oligomers modified by imidazolines

The molecular weight distribution of monoalkyl(C8–C12)phenolformaldehyde oligomers modified with imidazolines based on sunfl ower or corn oil fatty acids and polyamines – diethylenetriamine, triethylenetetraamine, polyethylene polyamines was determined by gel-chromatography. The influence of the component and quantitative composition on the parameters of the number average and weight average molecular weights, as well as on the polydispersity of oligomers, was studied. Regularities have been revealed and assumptions have been made regarding repeating monoalkyl (C8-C12)phenol-formaldehyde fragments in the composition of oligomeric macromolecules.

Effects of Wooden Breast Myopathy on Meat Quality Characteristics of Broiler Pectoralis Major Muscle and Its Changes with Intramuscular Connective Tissue.

This study aimed to investigate the effect of wooden breast (WB) myopathy on chemical composition, meat quality attributes and physiochemical characteristics of intramuscular connective tissue (IMCT) of broiler pectoralis major (PM) muscle. Thirty-six fillets were classified into varying degrees of WB condition, including normal, moderate and severe. Results show that WB myopathy altered the collagen profile in PM muscle by increasing total collagen content and decreasing collagen solubility. The composition of macromolecules in IMCT, including hydroxylysyl pyridoxine cross-linking, decorin and glycosaminoglycans, were increased with the severity of WB myopathy. Differential scanning calorimetry analysis indicated higher denaturation temperatures and lower denaturation enthalpy of IMCT for WB. Secondary structures of α-helix and β-sheet in the IMCT of WB were changed to β-turn and random coil. In addition, chemical composition and meat quality attributes showed a correlation with collagen profile and IMCT characteristics. Overall, this study emphasizes the effect of WB myopathy on IMCT and their contributions to meat quality variation.

Exploring the apoptotic effects of sericin on HCT116 cells through comprehensive nanostring transcriptomics and proteomics analysis

Sericin, a silk protein from Bombyx mori (silkworms), has many applications, including cosmetics, anti-inflammation, and anti-cancer. Sericin complexes with nanoparticles have shown promise for breast cancer cell lines. Apoptosis, a programmed cell death mechanism, stops cancer cell growth. This study found that Sericin urea extract significantly affected HCT116 cell viability (IC50 = 42.00 ± 0.002 µg/mL) and caused apoptosis in over 80% of treated cells. S-FTIR analysis showed significant changes in Sericin-treated cells' macromolecule composition, particularly in the lipid and nucleic acid areas, indicating major cellular modifications. A transcriptomics study found upregulation of the apoptotic signaling genes FASLG, TNFSF10, CASP3, CASP7, CASP8, and CASP10. Early apoptotic proteins also showed that BAD, AKT, CASP9, p53, and CASP8 were significantly upregulated. A proteomics study illuminated Sericin-treated cells' altered protein patterns. Our results show that Sericin activated the extrinsic apoptosis pathway via the caspase cascade (CASP8/10 and CASP3/7) and the death receptor pathway, involving TNFSF10 or FASLG, in HCT116 cells. Upregulation of p53 increases CASP8, which activates CASP3 and causes HCT116 cell death. This multi-omics study illuminates the molecular mechanisms of Sericin-induced apoptosis, sheds light on its potential cancer treatment applications, and helps us understand the complex relationship between silk-derived proteins and cellular processes.

Surface Properties of Gamma-Irradiated Polypropylene

polypropylene (PP) has been studied as a function of the absorbed dose. It has been established that γ-irradiation leads to an increase in the free surface energy of the polymer, its acid–base component, and the surface polarity. An analysis of the IR spectra of γ-irradiated PP samples indicated the formation of oxygen-containing groups in the composition of PP macromolecules, which was confirmed by the values of the surface acidity parameter. An increase in the dose led to an increase in the concentration of products of radiation-induced conversion. A significant increase in the melt flow index (MFI) of polypropylene up to an absorbed dose of 150 kGy also evidenced the occurrence of oxidation and destruction processes. The MFI decreased at radiation doses above 150 kGy, and this fact indicates that such doses of ionizing radiation lead to the predominance of the processes of polymer structuring or crosslinking.

Chitosan as a Canvas for Studies of Macromolecular Controls on CaCO3 Biological Crystallization.

A mechanistic understanding of how macromolecules, typically as an organic matrix, nucleate and grow crystals to produce functional biomineral structures remains elusive. Advances in structural biology indicate that polysaccharides (e.g., chitin) and negatively charged proteoglycans (due to carboxyl, sulfate, and phosphate groups) are ubiquitous in biocrystallization settings and play greater roles than currently recognized. This review highlights studies of CaCO3 crystallization onto chitinous materials and demonstrates that a broader understanding of macromolecular controls on mineralization has not emerged. With recent advances in biopolymer chemistry, it is now possible to prepare chitosan-based hydrogels with tailored functional group compositions. By deploying these characterized compounds in hypothesis-based studies of nucleation rate, quantitative relationships between energy barrier to crystallization, macromolecule composition, and solvent structuring can be determined. This foundational knowledge will help researchers understand composition-structure-function controls on mineralization in living systems and tune the designs of new materials for advanced applications.

Application of Unsupervised Learning for the Evaluation of Burial Behavior of Geomaterials in Peatlands: Case of Lignin Moieties Yielded by Alkaline Oxidative Cleavage

Tropical Peatlands accumulate organic matter (OM) and a significant source of carbon dioxide (CO2) and methane (CH4) under anoxic conditions. However, it is still ambiguous where in the peat profile these OM and gases are produced. The composition of organic macromolecules that are present in peatland ecosystems are mainly lignin and polysaccharides. As greater concentrations of lignin are found to be strongly related to the high CO2 and CH4 concentrations under anoxic conditions in the surface peat, the need to study the degradation of lignin under anoxic and oxic conditions has emerged. In this study, we found that the "Wet Chemical Degradation" approach is the most preferable and qualified to evaluate the lignin degradation in soils accurately. Then, we applied PCA for the molecular fingerprint consisting of 11 major phenolic sub-units produced by alkaline oxidation using cupric oxide (II) along with alkaline hydrolysis of the lignin sample presented in the investigated peat column called "Sagnes". The development of various characteristic indicators for lignin degradation state on the basis of the relative distribution of lignin phenols was measured by chromatography after CuO-NaOH oxidation. In order to achieve this aim, the so-called Principal Component Analysis (PCA) has been applied for the molecular fingerprint composed of the phenolic sub-units, yielded by CuO-NaOH oxidation. This approach aims to seek the efficiency of the already available proxies and potentially create new ones for the investigation of lignin burial along a peatland. Lignin phenol vegetation index (LPVI) is used for comparison. LPVI showed a higher correlation with PC1 rather than PC2. This confirms the potential of the application of LPVI to decipher vegetation change, even in a dynamic system as the peatland. The population is composed of the depth peat samples, and the variables are the proxies and relative contributions of the 11 yielded phenolic sub-units.

Exploring dietary approaches in the prevention and management of Amyotrophic Lateral Sclerosis: A literature review.

Amyotrophic lateral sclerosis (ALS) is a fatal and complex neurodegenerative disease of upper and lower motor neurons of the central nervous system. The pathogenesis of this multifaceted disease is unknown. However, diet has emerged as a modifiable risk factor that has neuroprotective effects towards other neurological disorders such as Alzheimer's, Parkinson's and dementia. Thus, this review aims to explore how diet can potentially influence ALS onset and/or progression. In this review, five popular diets (Mediterranean, Vegan, Carnivore, Paleolithic and Ketogenic) and their distinct macromolecule composition, nutritional profile, biochemical pathways and their potential therapeutic effects for ALS are thoroughly examined. However, the composition of these diets varies, and the data is controversial, with conflicting studies on the effectiveness of nutrient intake of several of these diets. Although these five diets show that a higher intake of foods containing anti-inflammatory and antioxidant compounds have a positive correlation towards reducing the oxidative stress of ALS, further research is needed to directly compare the effects of these diets and the mechanisms leading to ALS and its progression.

Chemical evolution of nucleic acids to sustain a life of Archaea

Archaea are a primary domain of the living kingdom, and they play an important role in biogeochemical cycles. Since the inclusion of new archaeal phylogenetic lineages in the universal tree, the origin and evolution history of this domain has been debated. To address this issue, we planned to examine the growth-associated maintenance energy and the proportion of nucleic acids in cell dry weight from 188 archaeal genomes. It was discovered that nucleotide molar fractions influenced evolutionary transmittance across archaeal phyla. At high concentrations of nucleotide molar fractions, minimal cell survivability of archaea was increased. Archaea's survival fitness may have evolved by chemically optimizing the growth-associated maintenance energy required for nucleic acid polymerization. The chemical composition of macromolecules in an archaeal cell may have also acted as a neutral selective pressure shaping its genome dynamics and cell survivability in transient environments. The current hypothesis provides a new look at reduced growth fitness of archaea in a diverse range of environmental niches.

Sulforaphane prevents and reverses allergic airways disease in mice via anti-inflammatory, antioxidant, and epigenetic mechanisms.

Sulforaphane has been investigated in human pathologies and preclinical models of airway diseases. To provide further mechanistic insights, we explored L-sulforaphane (LSF) in the ovalbumin (OVA)-induced chronic allergic airways murine model, with key hallmarks of asthma. Histological analysis indicated that LSF prevented or reversed OVA-induced epithelial thickening, collagen deposition, goblet cell metaplasia, and inflammation. Well-known antioxidant and anti-inflammatory mechanisms contribute to the beneficial effects of LSF. Fourier transform infrared microspectroscopy revealed altered composition of macromolecules, following OVA sensitization, which were restored by LSF. RNA sequencing in human peripheral blood mononuclear cells highlighted the anti-inflammatory signature of LSF. Findings indicated that LSF may alter gene expression via an epigenetic mechanism which involves regulation of protein acetylation status. LSF resulted in histone and α-tubulin hyperacetylation in vivo, and cellular and enzymatic assays indicated decreased expression and modest histone deacetylase (HDAC) inhibition activity, in comparison with the well-known pan-HDAC inhibitor suberoylanilide hydroxamic acid (SAHA). Molecular modeling confirmed interaction of LSF and LSF metabolites with the catalytic domain of metal-dependent HDAC enzymes. More generally, this study confirmed known mechanisms and identified potential epigenetic pathways accounting for the protective effects and provide support for the potential clinical utility of LSF in allergic airways disease.

Multi‐omics Analysis of S. Pneumoniae Extracellular Vesicles

Extracellular vesicles (EVs) are cell‐derived nanoparticles that can serve as carriers of DNA, RNA, and protein. For the pathogen S. pneumoniae,which causes diseases such as pneumonia and meningitis, EVs can be used to transport these macromolecules to recipient cells, facilitating communication and signaling between cells. However, the overall composition of these S. pneumoniaeEVs is still unknown and how the macromolecules packaged within these EVs contribute to the pathogenicity of S. pneumoniaeremains a hot research topic. In this work, we have developed a novel multi‐omic workflow that isolates DNA, RNA and protein from a single S. pneumoniaeEV starting sample, enabling analysis of these macromolecules without the need for multiple sample preparation steps and allowing us to gain insights into the composition and functionality of S. pneumoniaeEVs.EVs from a S. pneumoniaeculture were isolated and the proteins in the EV homogenate were labeled with the bifunctional ProMTag. One end of the ProMTag forms a reversible, covalent bond with proteins. ProMTag’s other functional group is methyltetrazine, which forms an irreversible bond with trans‐Cyclooctene (TCO), allowing capture of EV proteins on TCO‐agarose beads. Organic solvent was then added to precipitate the nucleic acids in the EV homogenate. Nucleic acids were released by a series of washes and subsequently separated into DNA and RNA fractions by RNase or DNase treatment, respectively. Proteins were then released from the TCO‐agarose beads by reversing the ProMTag‐protein linkage, yielding proteins in their original, unmodified state ready for analysis. DNA and RNA were sequenced, and proteins were identified using mass spectrometry. Using this workflow, we were able to describe the composition of multiple macromolecules within S. pneumoniaeEVs and gain insights into how these macromolecules might facilitate communication and infection within the S. pneumoniaepopulation.

Mechanistic study on oxidative degradation and deposition of exo-tetrahydrodicyclopentadiene

The advancement of propulsion systems accelerates the exploitation and application of various high-energy–density (HED) fuels, and yet severe oxidative-fouling hinders the adoption of such fuels in thermal-stressed conditions. In this work, we investigated the overall thermal-oxidative degradation and deposition process of a typical HED fuel, exo-tetrahydrodicyclopentadiene (exo-TCD), known as JP-10 (NHOC = 39.6 MJ/L), with the presence of oxygen. The oxidation mechanism of exo-TCD at relatively low temperatures is illustrated on the basis of experimental and computational results. For the first time, the chirality of oxidation products has been discussed, revealing the potential impact of radical configuration on the oxidation process of exo-TCD. Besides, an in-depth investigation on the deposition formation process was carried out by analyzing the structure and composition of polymeric macromolecules with the assistance of TG-IR-GC/MS technique. The oxidative deposition of exo-TCD is illustrated with a three-step mechanism of “oxidation”, “polymerization”, and “deposition”. The solubility of macromolecular species formed upon oxidation is decisive for the deposition propensity of fuels. This work aims to provide a theoretical and methodological basis for the future study on the oxidative stability of HED fuels.

THERMOSTABLE EPOXIDE COMPOSITION BASED ON AROMATIC DIAMIDODISULFOIMIDE RESIN

New epoxide oligomers have been obtained by the interaction of p-phenylenediaminediamidodisulfoimide with a large excess of epichlorohydrin in the presence of triethylbenzylammonium chloride. The synthesized epoxide oligomers are a viscous product of dark brown color, well soluble in aprotic solvents (DMFA, DMSO), as well as in acetone and dioxane. These cooligomers include hydroxynaphthylene and phenylenediimine structural fragments possessing solubility, meltability and high reactivity in the reactions with the oxirane ring of epoxide compounds in composition of macromolecules. The cooligomer of m-phenylenediamine with α-naphthol was used for curing of diamidodisulfoimide resin.

<i>Ulva lactuca</i> as Alternative Ferromagcalciforte Sustenance

Functional foods containing minerals, nutrients, as well as other active ingredients are essential to support physiological functions. The Chlorophyta macroalga Ulva lactuca (“sea lettuce”) is a popular natural food source due to its abundance in intertidal zones across Indonesia. To further examine its efficacy to the human physiology, analysis of proximate composition (carbohydrate, protein, fat, crude fibre, ash, and moisture content), macronutrient (Na, P, Ca, K, and Mg), micronutrient (Fe, Mn, Cu, Zn, Co, and Cr), heavy metal (Pb, Hg, and Cd), and fatty acid contents need to be done. Results showed that the highest composition of macromolecules is carbohydrates. Macronutrients and micronutrients with the highest values are Mg and Fe, respectively, with Ca also showing a high concentration. Pb and Hg contents are considered safe, but the Cd content exceeds the safety limit regulated by BPOM 2008. The fatty acids contained include methyl octadecenoate and the unsaturated fatty acid linolelaidic methyl ester. Mg, Ca, and Fe have important roles in the body’s systems, i.e., metabolic processes, growth and development, and enzyme activation. The presence of these elements suggests U. lactuca’s potential in maintaining the body’s physiological functions; however, the relatively high content of Cd must be noted.

Insights in quantitative indexes for better grouping and classification of Eucalyptus clones used in combustion and energy cogeneration processes in Brazil

The influence of the lignin macromolecule composition, extractives, volatile matter (VM), and fixed carbon (FC) contents on the reactivity and easiness of wood combustion is not fully understood, especially concerning species from fast-growing plantations. This study aims to close this scientific gap revealing the wood chemical composition effects on the combustibility of Eucalyptus clones. Moreover, we proposed new quantitative indexes that allow suitable grouping of genetic materials for energy purposes. The lignin, acetone-soluble extractives, VM, FC, and ash contents, as well as the ratio syringyl (S)/guaiacyl (G), were determined. The thermogravimetric analyses provided the combustion parameters. The characteristics that most contributed to the grouping of Eucalyptus clones were energy productivity (GJ ha−1 and GJ tree−1), energy density (GJ m−3), acetone-soluble extractives (% based on dry mass - db), VM (% db), and the maximum rate of combustion (% min−1). Clones with G units ≤20 g kg−1 db, acetone-soluble extractives ≤1.0% db, and FC ≤ 16% db had easier ignition and better reactivity during the burning. Clones with VM/FC ratio ≥5.0 showed maximum combustion rate ≥8.0% min−1 and acetone-soluble extractives ≤1.1% db. The findings of this investigation are useful to managers’ decision-making and contribute to the selection and rational use of the wood for energy purposes.

POSSIBILITIES OF IMPROVING QUALITY CHARACTERISTICS OF INACTIVE NEUTRAL LIGNOSULFONATES

The article proposes a method of increasing the amount of OH-phenolic functional groups in the composition of a macromolecule lignosulphonate, a sulfo-derivative natural lignin polymer, tested under laboratory conditions by step-by-step chemical treatment of the lignosulphonate matrix with a solution of a bromine derivative, then with a solution of neutral sodium sulfite. This makes it possible to solve the problem characteristic of modern lignosulphonates of neutral sulfite production method, which have low values of tannidicity index: content of OH-phenolic groups, quantitative content of which forms inhibitory (tanning) capacity of lignosulphonates. The proposed procedure involves carrying out said demethylation reaction with cleavage of methyl group contained in phenylpropane unit of lignosulfonate. Pyrocatechin groups are formed and methanesulfonic acid molecule is cleaved off. The obtained product was analyzed by UV spectroscopy and the increase in optical density in the area of absorption of 280 nm characteristic of OH-phenolic functional groups was shown, which is the basis for the appearance of pyrocatechin structures in the phenylpropane unit of lignosulfonate. Proposed method allows increasing quantitative content of OH-phenolic groups in macromolecule composition from 1.7% of initial to 6.5%. The obtained results are correlated with the data on determination of tannidicity index - one of objective characteristics of inhibitory (tanning) capacity of lignosulfnates, which is 32%, compared to similar characteristic of undemethylated neutral lignosulfonate, where the value did not exceed 21%. The data show that demethylation of the lignosulphonate matrix is possible by converting modern inactive neutral lignosulphonates from the low-demand waste category of the pulp and paper industry to a promising raw material component.

Analytical and Computational Advances, Opportunities, and Challenges in Marine Organic Biogeochemistry in an Era of “Omics”

Advances in sampling tools, analytical methods, and data handling capabilities have been fundamental to the growth of marine organic biogeochemistry over the past four decades. There has always been a strong feedback between analytical advances and scientific advances. However, whereas advances in analytical technology were often the driving force that made possible progress in elucidating the sources and fate of organic matter in the ocean in the first decades of marine organic biogeochemistry, today process-based scientific questions should drive analytical developments. Several paradigm shifts and challenges for the future are related to the intersection between analytical progress and scientific evolution. Untargeted “molecular headhunting” for its own sake is now being subsumed into process-driven targeted investigations that ask new questions and thus require new analytical capabilities. However, there are still major gaps in characterizing the chemical composition and biochemical behavior of macromolecules, as well as in generating reference standards for relevant types of organic matter. Field-based measurements are now routinely complemented by controlled laboratory experiments and in situ rate measurements of key biogeochemical processes. And finally, the multidisciplinary investigations that are becoming more common generate large and diverse datasets, requiring innovative computational tools to integrate often disparate data sets, including better global coverage and mapping. Here, we compile examples of developments in analytical methods that have enabled transformative scientific advances since 2004, and we project some challenges and opportunities in the near future. We believe that addressing these challenges and capitalizing on these opportunities will ensure continued progress in understanding the cycling of organic carbon in the ocean.

Miktoarm Star Polymers: Branched Architectures in Drug Delivery.

Delivering active pharmaceutical agents to disease sites using soft polymeric nanoparticles continues to be a topical area of research. It is becoming increasingly evident that the composition of amphiphilic macromolecules plays a significant role in developing efficient nanoformulations. Branched architectures with asymmetric polymeric arms emanating from a central core junction have provided a pivotal venue to tailor their key parameters. The build-up of miktoarm stars offers vast polymer arm tunability, aiding in the development of macromolecules with adjustable properties, and allows facile inclusion of endogenous stimulus-responsive entities. Miktoarm star-based micelles have been demonstrated to exhibit denser coronae, very low critical micelle concentrations, high drug loading contents, and sustained drug release profiles. With significant advances in chemical methodologies, synthetic articulation of miktoarm polymer architecture, and determination of their structure-property relationships, are now becoming streamlined. This is helping advance their implementation into formulating efficient therapeutic interventions. This review brings into focus the important discoveries in the syntheses of miktoarm stars of varied compositions, their aqueous self-assembly, and contributions their formulations are making in advancing the field of drug delivery.

RESEARCH ON THE EFFICIENCY OF USE OF NATURAL POLYMER FLOCCULANTS IN THE PROCESS OF WATER SOLUTION PURIFICATION

Natural flocculants are studied in the processes of water solution purification using the method of Jar-test. Experimental part of the work involves the research of different flocculants for the purification of colored water. The aim of this study is to determine the efficacy and optimal doses of flocculants in combination with aluminum sulfate. The flocculants such as chitosan, sodium alginate, starch and polyacrylamide are used for researching. As a coagulant, Al2(SO4)3·18H2O with a concentration of 10 % is used. It has been established that chitosan is the most effective flocculation reagent. It is explored that such factors as the dosage of reagents, chemical nature of links and the composition of polymer macromolecules, physical and chemical parameters of the process and the concentration of reagents influence the flocculation process. The optimal conditions for carrying out the process of flocculation are established

High-frequency microwave diagnostics of of free and bound water content in biological objects

Most biomaterial molecules are electrically neutral. Electrophysical properties of a biomaterial molecule are acquired when water molecules having a pronounced dipole moment bind to them. Therefore, the solution to the problem of determining the relationship of water with biological macromolecules and creation of methods for monitoring the state of water in biological objects is a step in the general problem of diagnosing their state.The composition of biological macromolecules, proteins includes intramolecular water. This affects both the real and the imaginary part of the dielectric constant of biological objects. The study is based on the fact that water has the greatest effect on the dielectric constant of the media in which it is located. With complex molecules of a biological substance, water can have bonds various in nature. Therefore, there is a significant set of physical factors associated with obtaining information about the state of biological objects based on determining the amount and distribution of free and integrated water in macromolecules of biological substances using microwave sensors relative to biological objects in vivo and in vitro, as well as during external exposure to them.The main ideas are based on the fundamental principles of radio physical methods for obtaining values of the real and imaginary parts of the dielectric constant in the frequency range of relaxation of macro-molecules of biological media with bound and free water.Information on the content and changes in the distribution of free and bound water in biological objects makes it possible to diagnose their state. Microwave diagnostics of biological objects using resonator transducers with coaxial probe structures provide an opportunity for non-destructive analysis with millimeter and submillimeter spatial resolution. Analytical methods were used to study the nature of the interaction of electromagnetic fields created by coaxial apertures of various configurations with samples. Based on the results obtained, the directions for the implementation of microwave high-local diagnostics techniques are determined.