Narrow Results

Cellulose with at least one of its dimensions less than or equal to 100 nm is termed as nanocellulose. It is a unique and promising natural material extracted from native cellulose and produced by certain microbial cells and cell-free systems. Nanocellulose has received immense consideration in last couple of decades owing to its abundance, renewability, remarkable physical properties, special surface chemistry, and excellent biological features (biocompatibility, biodegradability, and non-toxicity). Taking advantage of the structure and properties of nanocellulose, the current science of biomaterials aims at developing new and formerly non-existing materials with novel and multifunctional properties, in an attempt to meet current requirements in different fields such as biomedicine, the environment, energy, pharmaceutics, agriculture, food, etc. This chapter provides an overview of different synthesis methods of nanocellulose: mechanical approaches by applying high-pressure, grinding, crushing, sonication, and milling; chemical synthesis involving alkaline, acidic, oxidation, and enzymatic treatment; as well as by using bacteria and cell-free systems. It further discusses different morphological forms of nanocellulose including cellulose nanocrystals (CNCs), cellulose nanofibers (CNFs), bacterial nanocellulose (BNC), and cellulose produced by cell-free systems, in terms of their features such as chemical structure, macrostructural morphology, physico-mechanical properties, thermal and biological properties, rheology, optical behavior, and their interrelationships and applications.

The polyproline-II (PPII) structure domain is crucial in organisms’ signal transduction, transcription, cell metabolism, and immune response. It is also a critical structural domain for specific vital disease-associated proteins. Recognizing PPII is essential for understanding protein structure and function. To accurately predict PPII in proteins, we propose a novel method, AAindex-PPII, which only adopts amino acid index to characterize protein sequences and uses a Bidirectional Gated Recurrent Unit (BiGRU)-Improved TextCNN composite deep learning model to predict PPII in proteins. Experimental results show that, when tested on the same datasets, our method outperforms the state-of-the-art BERT-PPII method, achieving an AUC value of 0.845 on the strict data and an AUC value of 0.813 on the non-strict data, which is 0.024 and 0.03 higher than that of the BERT-PPII method. This study demonstrates that our proposed method is simple and efficient for PPII prediction without using pre-trained large models or complex features such as position-specific scoring matrices.

Temperature dependent X-ray diffraction (XRD) and dielectric properties of perovskite Ba(Zr${}_{0.2}$Ti${}_{0.8})$O₃ ceramic prepared using a standard solid-state reaction process is presented. Along with phase transitions at low temperature, a new phase transition at high temperature (873${}^{\circ }$C at 20Hz), diffusive in character has been found where the lattice structure changes from monoclinic (space group: $P2∕m)$ to hexagonal (space group: $P6∕mmm$). This result places present ceramic in the list of potential candidate for intended high temperature applications. The AC conductivity data followed hopping type charge conduction and supports jump relaxation model. The experimental value of $d_{33}=98$pC/N was found. The dependence of polarization and strain on electric field at room temperature suggested that lead-free Ba(Zr${}_{0.2}$Ti${}_{0.8})$O₃ is a promising material for electrostrictive applications.

X-ray diffraction and dielectric studies were performed on synthesized ceramic samples of the section (1–x) (0.8PbMg${}_{1∕3}$Nb${}_{2∕3}$O${}_3\cdot 0.2$BiScO₃)⋅ x(0.8PbTiO${}_3\cdot 0.2$BiScO₃) with $x=0$–1 of the ternary BiScO₃–PbTiO₃–PbMg${}_{1∕3}$Nb${}_{2∕3}$O₃ (BS–PT–PMN) system, including the temperature dependence of thermally stimulated depolarization currents (TSDC). It was found that the samples are solid solutions with a perovskite structure, which have cubic symmetry in the range of x = 0–0.587 and tetragonal symmetry in the range of x = 0.680–1. In the intermediate composition range of x = 0.587–0.680 (morphotropic region — MR), the samples consist of a mixture of solid solutions of different symmetries. Data on the change in dielectric properties and TSDC(T) dependencies of solid solutions with a change in their composition were obtained. It was found that samples of compositions x =0–0.625 and 0.6875–1 exhibit relaxor-ferroelectric and conventional ferroelectric properties, respectively, while samples of compositions x = 0.625–0.6875 combine ferroelectric and relaxor-ferroelectric properties.

This paper throws light on the preparation of transition metal-doped Mg${}_{0.5-x}T{M}_x$Zn${}_{0.5}$Al₂O₄ ($x=0$, 0.05 and $TM=\mathrm{\text{Co}}$, Ni, Cu) aluminates via solid-state reaction route. The X-ray diffraction characterization analysis confirmed that all the samples have crystallized into the psuedocubic phase having space group Fd3$m$ and were single phased. The incorporation of transition metals viz. Co${}^{2+}$, Ni${}^{2+}$, Cu${}^{2+}$ in the Mg${}_{0.5}$Zn${}_{0.5}$Al₂O₄ matrix does not result in the appearance of new peaks or any considerable shift in diffraction peaks within the limits of XRD experimentation. This infers homogeneous dispersion of dopants at the Mg-site which is attributed to nearly same ionic radii of the dopants to that of Mg-site in Mg${}_{0.5}$Zn${}_{0.5}$Al₂O₄. Lattice structure, bonding nature and hence the spinel formation were verified through Raman scattering technique. The compositional verification was carried out via energy dispersive analysis of X-rays (EDAX). The surface morphology and hence the microstructural studies were carried out using field emission scanning electron microscopy (FESEM). The synthesized Mg${}_{0.5-x}T{M}_x$Zn${}_{0.5}$Al₂O₄ ($x=0$, 0.05 and $TM=\mathrm{\text{Co}}$, Ni, Cu) aluminate samples were tested for polarization studies keeping their insulating nature into consideration and they displayed a sign of well-behaved P-E loop.

The peptide binding to Major Histocompatibility Complex (MHC) proteins is an important step in the antigen-presentation pathway. Thus, predicting the binding potential of peptides with MHC is essential for the design of peptide-based therapeutics. Most of the available machine learning-based models predict the peptide-MHC binding based on the sequence of amino acids alone. Given the importance of structural information in determining the stability of the complex, here we have utilized both the complex structure and the peptide sequence features to predict the binding affinity of peptides to human receptor HLA-A*02:01. To our knowledge, no such model has been developed for the human HLA receptor before that incorporates both structure and sequence-based features.

Results:

We have applied machine learning techniques through the natural language processing (NLP) and convolutional neural network to design a model that performs comparably with the existing state-of-the-art models. Our model shows that the information from both sequence and structure domains results in enhanced performance in the binding prediction compared to the information from one domain alone. The testing results in 18 weekly benchmark datasets provided by the Immune Epitope Database (IEDB) as well as experimentally validated peptides from the whole-exome sequencing analysis of the breast cancer patients indicate that our model has achieved state-of-the-art performance.

Conclusion:

We have developed a deep-learning model (OnionMHC) that incorporates both structure as well as sequence-based features to predict the binding affinity of peptides with human receptor HLA-A*02:01. The model demonstrates state-of-the-art performance on the IEDB benchmark dataset as well as the experimentally validated peptides. The model can be used in the screening of potential neo-epitopes for the development of cancer vaccines or designing peptides for peptide-based therapeutics. OnionMHC is freely available at https://github.com/shikhar249/OnionMHC.

Vinylidene fluoride-trifluoroethylene copolymer films of molar ratio 70/30 with thickness of about 1 $\mu$m have been deposited from solution in ethyl methyl ketone to a glass substrate with an aluminum electrode by spin coating. The solution has been filtrated through a PTFE membrane filter with pore size 0.2 $\mu$m directly before spin coating or it has been used as is (unfiltrated). After deposition of a top electrode, the samples have been polarized by hysteresis loops with an electric field amplitude of about 100 V/$\mu$m. In samples, annealed at temperature 145${}^{\circ }$C for 3 h, a high remanent polarization of about 7.5 $\mu$C/cm² has been achieved, without significant differences between samples fabricated of filtrated or unfiltrated solution. Spherulitic lamella are growing in films fabricated of filtrated solution when they are heated above the melting temperature to 159${}^{\circ }$C for 3 min before the further annealing process at 145${}^{\circ }$C. These films show substantially lower remanent polarization below 4 $\mu$C/cm². Pyroelectric images recorded with a pyroelectric laser scanning microscope show that the spherulites have very small pyroelectric activity, i.e., the spherulites consist of flat-on lamella. In contrast, no spherulitic lamella are growing in films fabricated of unfiltrated solution heated above the melting temperature, melted and annealed under the same conditions. An explanation for this observation is that filtrating changes the structure of the copolymer in solution from polymer coil to rod. Copolymer rods deposited on a substrate will crystallize in flat-on lamella when heated above the melting temperature, in contrast to copolymer coils which crystallize in edge-on lamella.

The preparation of ${\text{La}}_{0.9}$${\text{Na}}_{0.1}$CrO₃ (LNCO), ${\text{Ni}}_{0.5}$${\text{Cu}}_{0.5}$Fe₂O₄ (NCFO) and their composites of the type $(1-x)$${\text{La}}_{0.9}$${\text{Na}}_{0.1}$CrO₃ (LNCO) $+$ ($x$) ${\text{Ni}}_{0.5}$${\text{Cu}}_{0.5}$Fe₂O₄ (NCFO) $(x=0.25$, 0.50$)$ through solid state route is reported. From X-ray diffraction data analysis, the parent ${\text{La}}_{0.9}$${\text{Na}}_{0.1}$CrO₃ was found to crystallize in orthorhombic structure (Pnma) while ${\text{Ni}}_{0.5}$${\text{Cu}}_{0.5}$Fe₂O₄ has crystallized into the cubic structure (Fd3$m$) further verified via Retvield refinement. The morphology and compositional studies were carried out using field emission scanning electron microscopy (FESEM) and energy dispersive analysis of X-rays (EDAX), respectively. Lattice structure was confirmed via Raman characterization for the prepared samples. The sample formation was further verified through Fourier transform Infra-Red (FTIR) spectroscopy. The dielectric studies reveal the ${\text{La}}_{0.9}$${\text{Na}}_{0.1}$CrO₃$(13*10^4)$ and ${\text{Ni}}_{0.5}$${\text{Cu}}_{0.5}$Fe₂O₄$(1.83*10^4)$ exhibit high dielectric constant. However, their composites show abrupt drop in dielectric constant. The electric modulus study confirmed that the samples exhibit non-Debye character with spread of relaxation time constants.

This paper presents the results of studies of the structure, microstructure, dependences of the piezoelectric properties on the electric field (dielectric hysteresis loops, reversible nonlinearity, deformation characteristics) and dielectric properties of the ceramic material PCR-13 (based on the PZT system) in the temperature range 300–900K and frequencies of an alternating electric field ($25÷2\cdot 10^6$) Hz. The character of the obtained dependences made it possible to attribute PCR-13 to ferro-hard materials. Using the HF cathodic sputtering method, PCR-13 thin films were fabricated on Si (001) substrates. It is shown that they are polycrystalline textured, while in comparison with bulk material, the film contains tensile stresses of the unit cell in the plane of the substrate and compresses in the perpendicular direction with the value ${\epsilon }_{33}=-0.018$. The capacitance-voltage characteristics of the Al/PCR-13/Si/Al heterostructure were studied. The reasons for the revealed patterns are discussed.

The results of a comprehensive study of the crystal structure, grain structure, and strength properties of ceramic bismuth ferrite with rare earth elements (REE) obtained by two-stage solid-phase synthesis followed by sintering using conventional ceramic technology are presented. The reasons for the formation of low mechanical strength and the development of destruction phenomena in solid solutions with small REE ($\bar{R}<0.94$ Å) are considered: Tb, Dy, Ho, Er, Tm, Yb, Lu. The causes of the observed phenomena associated with the composite-like structure of the studied media and, as a consequence, the occurrence of local stresses of structural elements that provoke crack formation are established. A source of the latter are also the structural features of the grain landscape. The conclusion is made about the appropriateness of taking into account the information obtained when developing devices based on BiFeO₃/REE multiferroics.

X-ray diffraction studies of synthesized Ba₂TiSi₂O₈ have shown that this compound has a fresnoite structure and is characterized by a polar phase $P$4bm at room temperature. The synthesis of Pb₂TiSi₂O₈ in the fresnoite phase under the selected synthesis conditions has led to the formation of a perovskite tetragonal phase $P$4mm corresponding to PbTiO₃.

Expanded nonaromatic stable porphyrins(2.1.2.1) were successfully synthesized by 2,3-di(1H-pyrrol-2-yl)naphthalene as buliding blocks and aromatic aldehydes under acid catalyzed condensation conditions in acceptable isolated yields. NMR, X-ray diffraction analysis, absorption, electrochemical, and density functional theory revealed these macrocycles to be non-aromatic due to highly saddle-shaped molecular structures of dinaphthoporphyrin(2.1.2.1). The saddle-shaped dinaphthoporphyrins(2.1.2.1) with embedded naphthalene units as $\pi$-conjugation units show perturbations to molecular structure, optical and electronic properties. The dinaphthoporphyrins(2.1.2.1) are effective macrocyclic ligands giving copper(II) and nickel(II) complexes.

A knowledge graph is a visual method that can display the information contained in the knowledge points, core structure, and comprehensive knowledge structure technology. In recent years, with the innovation of science and technology, the business field became keen on knowledge graphs and the graphical display method. However, the application of knowledge graphs in the business field is mainly limited to search engines, question, and answer systems because of the technical difficulties of knowledge extraction and knowledge graph drawing of unstructured text, especially the knowledge extraction of amorphous culture. It can provide knowledgeable service to users by analyzing the knowledge entity contained in encyclopedia knowledge or knowledge base. This paper will focus on the critical link of knowledge extraction of the knowledge graph, adopt a depth learning algorithm to solve this urgent problem and combine with the application of knowledge graph in substation fault to analyze the construction process of substation fault knowledge map based on AI.

Cancer threatens the life and well-being of human beings. Millions of newly diagnosed cancer cases and a large number of deaths caused by cancer are reported each year in the world. Early detection and effective treatment are key to reduce cancer mortality, which can be potentially realized by using “theranostics”. Theranostics are a group of hybrid nanoparticles that perform in cancer patients to provide both diagnostic and therapeutic functions through a single nano-sized structure. In particular, core-shell structured theranostics have shown unique physicochemical properties, allowing them to facilitate molecular/cell targeting, bio-imaging, and drug delivery functions. This review, therefore, aims to present and discuss the recent development of research on core-shell structured theranostics. Specifically, it focuses on core-shell structured theranostics made of metals, silica and polymers. Different aspects, such as synthesis and structure, of core-shell structured theranostics are discussed in this review. This review helps readers to have a good understanding of the design and fabrication of core-shell structured theranostics.

Proanthocyanidins (PAs) are a group of polyphenols enriched in plant and human food. In recent decades, epidemiological studies have upheld the direct relationship between PA consumption and health benefits; therefore, studies on PAs have become a research hotspot. Although the oral bioavailability of PAs is quite low, pharmacokinetics data revealed that some small molecules and colonic microbial metabolites of PAs could be absorbed and exert their health beneficial effects. The pharmacological effects of PAs mainly include anti-oxidant, anticancer, anti-inflammation, antimicrobial, cardiovascular protection, neuroprotection, and metabolism-regulation behaviors. Moreover, current toxicological studies show that PAs have no observable toxicity to humans. This review summarizes the resources, extraction, structures, pharmacokinetics, pharmacology, and toxicology of PAs and discusses the limitations of current studies. Areas for further research are also proposed.

The effect of 2MeV energy electrons with fluences from $0.5\times 10^{17}$ to $4.0\times 10^{17}$ electron/cm² on the crystal structure, surface morphology, absorption spectrum, band gap, Raman spectrum and microhardness of ZnS crystal was investigated. The crystal structure of ZnS is face-centered cubic with space group F-43m. Upon irradiation with a fluence of $4\times 10^{17}$ electron/cm², the unit cell parameter decreased by 0.0195Å, and the coordinates of the Zn${}^{+2}$ ions were changed. Irradiation with fluences ranging from $0.5\times 10^{17}$ to $4\times 10^{17}$ electron/cm² increased crystallite size from 20nm to 28nm. The study of the surface morphology of the ZnS single-crystal revealed that irradiation caused a reduction in both the width ($R_a$) and height ($R_z$) of the surface roughness. The band gap of the ZnS single-crystal decreased from 3.521 to 3.506eV when irradiated with fluence electrons from $0.5\times 10^{17}$ to $2.5\times 10^{17}$electron/cm². Raman spectrum observations showed an increase in the longitudinal optical (LO) mode peak (350cm${}^{-1}$) intensity following the irradiation of ZnS single-crystal with electrons. The microhardness of the ZnS single-crystal showed an exponential increase by 20% when irradiated with fluences from $0.5\times 10^{17}$ to $2.5\times 10^{17}$electron/cm².

Magnitude, similar to concepts like volume, cardinality or Euler characteristic, has become a key focus in combinatorics and topology. Recent advancements in topological data analysis and persistent homology have emphasized its importance. Persistent magnitude, a newly highlighted invariant introduced by Govc and Hepworth, has emerged as a notable subject of interest. In this work, we apply persistent magnitude to analyze and predict the stability of closo-carborane structures. First, we assess the stability of carboranes by employing cross-validation with different magnitude features. The Pearson correlation coefficients for stability predictions using three distinct magnitude features are 0.900, 0.882 and 0.883, respectively. These results are comparable to the Pearson correlation coefficient of 0.881 obtained when using a single feature based on persistent homology. Second, the utilization of magnitude features to predict the HOMO, LUMO and HOMO–LUMO gaps of carboranes involves conducting eight gradient boosting regressions for each scenario. The lowest correlation coefficients observed are 0.9056, 0.9385 and 0.9427, respectively. These findings highlight the promising performance of persistent magnitude features in the analysis of material structure and stability.

The equilibrium and stability of anisotropic strange stars is analyzed. For this purpose, we consider that the anisotropy factor follows the equation σ = k p_r(1 − e^−λ); being k a constant, p_r the radial pressure and e^−λ a metric function. We found that the anisotropy yields considerable changes in some macroscopic properties of strange stars. Despite this, such as is determined in isotropic strange stars, the onset of the instability is marked by the maximum mass point. This indicates that stable and unstable equilibrium configurations can be recognize through the conditions dM/d_ρc > 0 and dM/d_ρc < 0, respectively.

Thanks to the tremendous progress in data, computing power and algorithms, AI-based material mining and design have gained much attention. However, building high-performance AI models requires efficient material structure representation. In this work, we propose a structural characterization method based on the neighborhood path complex for the first time. Specifically, we use persistent neighborhood path homology to obtain the structural features by introducing a filtration. This approach preserves more elemental information, as well as the corresponding physicochemical information, through the directed edges of the neighborhood digraph. To validate our model, we perform cross-validation with the carborane structures. The Pearson coefficient for stability prediction is as high as 0.903, which is a 15.5% improvement compared to the traditional persistent homology method. In addition, we constructed a prediction model based on the neighborhood path complex, and the Pearson coefficients for the prediction of carboranes’ HOMO, LUMO, and HOMO–LUMO gaps were 0.915, 0.946, and 0.941, respectively. The results show that our proposed method can effectively extract structural information and achieve accurate material property prediction.

Ni thin films have been electrodeposited on $n$-Si (100) substrates for different deposition times at a fixed potential of 2V. The as-elaborated films have been characterized by Rutherford backscattering spectroscopy (RBS), X-ray diffraction (XRD), atomic force microscopy (AFM) and vibrating sample magnetometry (VSM). From RBS spectra, we have extracted the Ni film thicknesses, $t(\mathrm{\text{nm}})$, which ranges from 105 nm to 710 nm. The analysis of XRD spectra shows the existence of a strong $⟨$111$⟩$ texture for all film thicknesses. The strain values ${\epsilon }^{hkl}$ are negative for all Ni films indicating that they are under compressive stresses. The grains size, $〈D(\AA )〉$, increases to reach a maximum for $t=465$nm then decreases again with increasing $t$(nm). From AFM images, we have shown that the films become progressively smoother with increasing thickness. We have shown that the coercive field measured in parallel geometry, $H_{C||}$, increases with increasing thickness.