Strong Physical Interaction Research Articles

Effect of Cloisite 15A on the mechanical properties of an abaca-based composite

Abstract The combined effect of resin containing nanoclay along with natural fibers elevates the mechanical properties. In addition, the dispersion of nanoclay at the fiber-matrix interface would create strong physical interaction between the two. The significant enhancement in mechanical properties is achieved for the composite containing 30 wt.% abaca fiber content and 2 wt.% nanoclay, which is treated by 8 vol.% NaOH concentration. The enhancement in the mechanical properties can be attributed to the wettability of fiber by the matrix, homogeneous distribution of fibers and nanoclay in the matrix phase and physical interaction between reinforcement and matrix. Increase in the addition of abaca fiber and nanoclay beyond the above mentioned content leads to drop in the mechanical properties. This can be due to many nanoclay agglomerates are not broken down to nano scale during preparation, it may also be the reason for drop in the mechanical properties.

Folate-conjugated thermal- and pH-responsive magnetic hydrogel as a drug delivery nano-system for “smart” chemo/hyperthermia therapy of solid tumors

A folate-conjugated pH- and thermal-sensitive magnetic hydrogel composed of poly(vinyl alcohol) (PVA), poly(N-isopropylacrylamide) (PNIPAAm), folate-conjugated poly(acrylic acid) (PAA-FA), and Fe3O4 nanoparticles (NPs) was developed as a “smart” drug delivery system (DDS) for chemo/hyperthermia therapy of cancer cells. Following fabrication, the hydrogels were incorporated with doxorubicin hydrochloride (Dox) physically. Owing to the porous structure of the polymeric matrix and strong physical interactions between the hydrogel and Dox, the developed DDS showed suitable loading (LE) and encapsulation (EE) efficiencies (7.3 ± 0.26 and 87 ± 2.6%, respectively). At pH 7.4 and 37 °C (physiological condition), low rate of drug release was observed from the DDS. At the tumor condition (lower pH and higher temperature), the DDS presented adequate pH- and thermal-responsive drug release behavior. Cytotoxicity of the Dox-loaded DDS in chemotherapy and hyperthermia/chemotherapy against MCF-7 cells was evaluated by MTT assay. The developed DDS showed synergic cancer therapy process by combination of chemotherapy and hyperthermia approaches.

Solvent-responsive strong hydrogel with programmable deformation and reversible shape memory for load-carrying soft robot

The development of shape deformation hydrogels has aroused interests of their immense applications in diverse fields such as actuators, soft robotics, and artificial muscles. However, the existing deformable hydrogels can hardly meet the requirements of facile preparation, excellent mechanical properties and reversible shape memory, which greatly limits their further applications. In this work, a new type of fully physically cross-linked deformable hydrogel with mechanically strong, tough, stretchable, and solvent-responsive property is fabricated via free radical polymerization at room temperature, followed by immersed in a Fe3+ aqueous solution. The strong physical interactions of polyacrylic acid (PAA)-Fe3+ metal complexation and hydrogen bond endowed this hydrogel with high tensile strength (~5.14 MPa), high stretchability (~1000%), high toughness (~20.36 MJ/m3) and excellent flexibility (~0.53 MPa). In addition, programmable shape deformation hydrogel is achieved by selective coating of Fe3+ on surface, the hydrogel strips can be deformed into arbitrary shapes such as the letter “o”, “d”, “s”, and “w”. More impressively, reversible shape recovery of hydrogel has been achieved via two methods: the elimination of coated Fe3+ with the reaction of NaOH and the dehydration of the glycerin. Taking advantage of this property, we simulate the closure and opening of hydrogel flower by soaking it into water and NaOH/glycerin alternately. Moreover, the soft robotic gripper has been fabricated based on the mechanically strong and solvent-triggered hydrogel, capable of grabbing about 1.56 times its own weight, which indicating the potential application as load-carrying soft robots.

Hydrogel tapes for fault-tolerant strong wet adhesion

Fast and strong bio-adhesives are in high demand for many biomedical applications, including closing wounds in surgeries, fixing implantable devices, and haemostasis. However, most strong bio-adhesives rely on the instant formation of irreversible covalent crosslinks to provide strong surface binding. Repositioning misplaced adhesives during surgical operations may cause severe secondary damage to tissues. Here, we report hydrogel tapes that can form strong physical interactions with tissues in seconds and gradually form covalent bonds in hours. This timescale-dependent adhesion mechanism allows instant and robust wet adhesion to be combined with fault-tolerant convenient surgical operations. Specifically, inspired by the catechol chemistry discovered in mussel foot proteins, we develop an electrical oxidation approach to controllably oxidize catechol to catecholquinone, which reacts slowly with amino groups on the tissue surface. We demonstrate that the tapes show fast and reversible adhesion at the initial stage and ultrastrong adhesion after the formation of covalent linkages over hours for various tissues and electronic devices. Given that the hydrogel tapes are biocompatible, easy to use, and robust for bio-adhesion, we anticipate that they may find broad biomedical and clinical applications.

Highly Tough, Stretchable, and Enzymatically Degradable Hydrogels Modulated by Bioinspired Hydrophobic β-Sheet Peptides.

Peptide-based supramolecular hydrogels have attracted great attention due to their good biocompatibility and biodegradability and have become promising candidates for biomedical applications. The bottom-up self-assembly endows the peptides with a highly ordered secondary structure, which has proven to be an effective strategy to improve the mechanical properties of hydrogels through strong physical interactions and energy dissipation. Inspired by the excellent mechanical properties of spider-silk, which can be attributed to the rich β-sheet crystal formation by the hydrophobic peptide fragment, a hydrophobic peptide (HP) that can form a β-sheet assembly was designed and introduced into a poly(vinyl alcohol) (PVA) scaffold to improve mechanical properties of hydrogels by the cooperative intermolecular physical interactions. Compared with hydrogels without peptide grafting (P-HP0), the strong β-sheet self-assembly domain endows the hybrid hydrogels (P-HP20, P-HP29, and P-HP37) with high strength and toughness. The fracture tensile strength increased from 0.3 to 2.1 MPa (7 times), the toughness increased from 0.4 to 21.6 MJ m-3 (54 times), and the compressive strength increased from 0.33 to 10.43 MPa (31 times) at 75% strain. Moreover, the hybrid hydrogels are enzymatically degradable due to the dominant contribution of the β-sheet assembly for network cross-linking. Combining the good biocompatibility and sustained drug release of the constructed hydrogels, this hydrophobic β-sheet peptide represents a promising candidate for the rational design of hydrogels for biomedical applications.

SNP rs4971059 predisposes to breast carcinogenesis and chemoresistance via TRIM46-mediated HDAC1 degradation.

Identification of the driving force behind malignant transformation holds the promise to combat the relapse and therapeutic resistance of cancer. We report here that the single nucleotide polymorphism (SNP) rs4971059, one of 65 new breast cancer risk loci identified in a recent genome-wide association study (GWAS), functions as an active enhancer of TRIM46 expression. Recreating the G-to-A polymorphic switch caused by the SNP via CRISPR/Cas9-mediated homologous recombination leads to an overt upregulation of TRIM46. We find that TRIM46 is a ubiquitin ligase that targets histone deacetylase HDAC1 for ubiquitination and degradation and that the TRIM46-HDAC1 axis regulates a panel of genes, including ones critically involved in DNA replication and repair. Consequently, TRIM46 promotes breast cancer cell proliferation and chemoresistance invitro and accelerates tumor growth invivo. Moreover, TRIM46 is frequently overexpressed in breast carcinomas, and its expression is correlated with lower HDAC1 expression, higher histological grades, and worse prognosis of the patients. Together, our study links SNP rs4971059 to replication and to breast carcinogenesis and chemoresistance and support thepursuit of TRIM46 as a potential target for breast cancer intervention.

A robust polymeric binder based on complementary multiple hydrogen bonds in lithium-sulfur batteries

The practical application of sulfur cathodes in traditional lithium–sulfur batteries has been hindered by the substantial deterioration of the sulfur electrode due to the polysulfide shuttling effect and the large volume expansion of the electrode during charge/discharge cycling. The resolving of this issue demands for a robust binder to hold the polysulfide/sulfur particles, but without causing severe disintegration of the electrode. A polar polymeric binder with high mechanical strength was designed and synthesized for use in high-performance sulfur cathodes. The complementary multiple hydrogen bonds formed in the polymeric binder significantly enhanced the adhesive strength of the binder, and buffered the dramatic volume expansion of the sulfur cathode during cycling. The strong physical and chemical interactions between the functional groups (e.g. carboxyl and tertiary amine groups) of the binder and the polysulfides effectively mitigated the shuttling effect in the Li–S batteries. As a consequence, the sulfur cathode exhibited excellent electrochemical performance at a high sulfur loading, yielding an initial discharge capacity of 627.8 mA h g−1 with sulfur loading up to 9.610 mg cm−2 at a rate of 0.2C, corresponding to an aerial capacity of 6.03 mA h cm−1. The present work opens a new avenue for constructing a high-performance Li–S battery using a simple and effective binder.

Comprehensive Analysis of Prognostic Value of MEX3A and Its Relationship with Immune Infiltrates in Ovarian Cancer.

MEX3A is a critical RNA-binding ubiquitin ligase that is upregulated in various types of cancer. However, the correlations of MEX3A with prognosis and its molecular mechanism in ovarian cancer (OC) remain unclear. The expression level, prognostic values, and the genetic variations of MEX3A were analyzed via Gene Expression Profiling Interactive Analysis (GEPIA) Oncomine, Kaplan–Meier plotter, and cBioPortal. We used the LinkedOmics database to investigate the functions of MEX3A coexpressed genes and performed visualizing gene interaction network analysis on the GeneMANIA website. The correlations between MEX3A and cancer immune infiltration were analyzed by the Tumor Immune Estimation Resource (TIMER) site and the TISIDB database. Furthermore, in vitro analysis was performed to evaluate the biological functions of MEX3A in OC cells. Our study showed that the expression of the MEX3A in OC was higher than in normal tissues; it had the greatest prognostic value in OC, and strong physical interaction with PABPC1, LAMTOR2, KHDRBS2, and IGF2BP2, which indicated the association between MEX3A and immune infiltration. We also found that MEX3A was negatively related to infiltrating levels of several types of immune cells, including macrophages, neutrophils, dendritic cells (DCs), B cells, and CD8+ T cells. Additionally, in vitro experiments demonstrated that MEX3A promotes proliferation and migration in OC cells. Taken together, MEX3A might influence the biological functions of OC cells by regulating the immune infiltration in the microenvironment as a prognostic biomarker and a potential therapeutic target.

Applications of Tin Oxide in the Field of Wearable Technology

Escalating rapidity in the technology leads to the exploration of wearable and mobile devices. There is paramount importance of wearable technology for health management as diseases can be timely monitored which in turn circumvent severe medical situations and decrease economic losses. Wearable technology involves the integration of electronic components into textiles or fabrics for wide range of applications including sensors, medical devices and safety instruments [1, 2]. Textiles, owing to their flexible and capillary characteristic, hold imperative position in the fabrication of rapid and inexpensive point-of-care sensing devices [3]. Metal oxides are affirmed to have potential applications in the fabrication of wearable sensors because of their unique electrical, electrochemical and biocompatible properties. With high surface to volume ratio, the sensitivity, selectivity and catalytic activity of metal oxide semiconductors is greatly enhanced. They serve as excellent candidates for the next generation of wireless sensing and online monitoring applications due to the fast response and long lifetime in different environmental conditions. Among the metal oxide semiconductors, SnO2 is considered as one of the important material due to their number of properties, like biocompatibility, anti-oxidant , anti-bacterial, cytotoxic properties, strong physical and chemical interactions with adsorbed species, high degree of transparency in the visible spectrum, low operating temperature etc. [4]. There is an increased usage of SnO2 as modifier electrode materials because of its astonishing features of thermal stability, biocompatibility, excellent bandgap, cost effective and abundant availability. The surface of working electrode is modified by nanomaterials of SnO2 in combination with various metals, semiconductors and carbon derivatives for improved sensing performance. As per the recent reports, tin oxide in find its applications in the field of glucose sensing [5], gas sensing [6], monitoring heavy metals [7], phenol sensing [8] etc. Apart from the reported applications, tin oxide is proved to be a useful candidate in stealth technology [9]. References Y. Yun, W.G. Hong, N. J.Choi, H.B. Kim, Y. Jun, H.K. Lee, Sci. Rep. 5 (2015) 10904.Skrzetuska, M. Puchalski, I. Krucinska, Sensors 14 (2014) 16816.Li, J. Tian, W. Shen, ACS Appl. Mater. Interfaces 2 (2010) 1.Vidhu, D. Philip, Spectrochim. Acta, Part A 134 (2015) 372.Sedighi, M. Montazer, S. Mazinani, Biosens. Bioelectron. 135 (2019) 192.Wang, C. Zhao, T. Han, Y. Zhang, S. Liu, T. Fei, S. Liu, T. Zhang, Sens. Actuators, B 242 (2017) 269.Wei, C. Gao, F.L. Meng, H.H. Li, L. Wang, J.H. Liu, X.J. Huang, J. Phys. Chem. C 116 (2011)1034.Guo, P. Cai, , J. Sun, W. He, X. Wu, T. Zhang, X. Wang, Carbon 99 (2016) 571.M Jeong, J. Ahn, Y. K. Choi, T. Lim, K. Seo, T. Hong, G. H. Choi, H. Kim, B. W. Lee, S.Y. Park, S. Ju, NPG Asia Materials 12 (2020) 32.

Optimization of heat-sealing properties for antimicrobial soybean protein isolate film incorporating diatomite/thymol complex and its application on blueberry packaging

Heat-sealing parameters of the as-prepared antimicrobial soybean protein isolate (SPI) film incorporating diatomite/thymol complex (S/D/T film) were optimized using single factor experiment and response surface methodology, and further used to seal the films into packaging bags to preserve blueberries at 25 °C and 70 % relative humidity. The S/D/T film had a maximum sealing strength of 2.41 N/15 mm at the optimized sealing conditions of 139.5 °C, 2.5 s and 0.48 MPa due to the strong physical intermolecular interaction induced upon heat-sealing areas as confirmed by FT-IR and SEM. Moreover, the S/D/T film could effectively delay the deterioration in blueberry quality during 5 days of storage, exhibiting better fresh-keeping effect than other groups. Additionally, all films were completely biodegraded in soil within 8 days. In summary, the developed antimicrobial protein films with improved heat-sealing ability and excellent biodegradability can provide a promising alternative to nondegradable synthetic materials in active packaging.

Unidirectional cooperative binding of fimbrin actin-binding domain 2 to actin filament

Fimbrin forms bundles of parallel actin filaments in filopodia, but it remains unclear how fimbrin forms well-ordered bundles. To address this issue, we focused on the cooperative interaction between the actin-binding domain of fimbrin and actin filaments. First, we loosely immobilized actin filaments on a glass surface via a positively charged lipid layer and observed the binding of GFP-fused actin-binding domain 2 of fimbrin using fluorescence microscopy. The actin-binding domain formed low-density clusters with unidirectional growth along actin filaments. When the actin filaments were tightly immobilized to the surface by increasing the charge density of the lipid layer, cluster formation was suppressed. This result suggests that the propagation of cooperative structural changes of actin filaments evoked by binding of the actin-binding domain was suppressed by a strong physical interaction with the glass surface. Interestingly, binding of the fimbrin actin-binding domain shortened the length of loosely immobilized actin filaments. Based on these results, we propose that fimbrin-actin interactions accompanied by unidirectional long-range allostery help the formation of well-ordered parallel actin filament bundles.

Rheology of an alkali-activated Fe-rich slag suspension: Identifying the impact of the activator chemistry and slag particle interactions

Iron-silicate slags, originating from metallurgical industry, are upon alkali-activation precursors for synthesis of inorganic polymer binders, which can be used in construction. The slag's rheology is important for certain construction applications, which is for alkali-activated Fe-rich slag suspensions (AAS) still largely unmapped. To identify the contribution of the activator and of an early formed binder to the rheology, the activator SiO2/Na2O molar ratio and H2O content was modified. The flow behaviour of AAS was compared with an activator alone, and a quartz suspension to reveal the effect of the slag particles on the rheology and its degree of activation. Raising SiO2/Na2O molar ratio resulted in a higher yield stress and elasticity, explained by the increase of silicate complexes, while decreasing SiO2/Na2O molar ratio resulted in more monomers. AAS exhibited a yield stress fluid-like behaviour conform to the Herschel-Bulkley model and driven by the strong physical interaction between the slag particles.

EPEN-04. ONCOGENIC 3D TUMOR GENOME ORGANIZATION IDENTIFIES NEW THERAPEUTIC TARGETS IN EPENDYMOMA

By profiling enhancers in primary ependymoma tumors, we have recently identified putative oncogenes, molecular targets, and functional pathways. Inhibition of selected targets diminished the proliferation of patient-derived neurospheres and increased survival in mouse models of ependymoma. While enhancers frequently regulate the nearest gene, identification of enhancer target genes remains to be a challenge in the absence of chromosome conformation information. Consequently, we have now used HiC to map the 3-dimensional organization of tumor chromatin in the two most common and aggressive ependymoma subgroups: posterior fossa group A (PF-EPN-A) and supratentorial ependymomas with gene fusions involving the NF-κB subunit gene RELA (ST-EPN-RELA). By an integrative analysis of enhancer and gene expression in the context of the newly derived HiC data, we find that a large number of the predicted enhancer target genes are enriched for strong physical interactions. Importantly, we also identify many new putative tumor-dependency genes activated by long-range promoter-enhancer interactions and complex tumor-specific chromatin clusters of regulatory elements. Complementary to the analysis of gene-enhancer interactions, we have also leveraged the HiC data for resolving structural rearrangements underlying copy number alterations. Copy number gains of the 1q arm of chromosome 1 are especially associated with poor survival. Our preliminary results in PFA relapse samples show complex structural variants underlying 1q gain that lead to inter-chromosomal rearrangements and affect several genes that potentially contribute to poor survival. In ongoing work we are testing the relevance of the novel candidate genes for tumor cell growth and proliferation in-patient derived ependymoma models.

Molybdenum disulfide as a filler for a polymeric matrix at an ultralow content: Polystyrene case

For the first time, polystyrene (PS)/molybdenum disulfide (MoS2) nanocomposites were produced using the melt compounding technique. The nanocomposites presented better thermo stability due to improvements in heat dissipation. Mechanical evaluations of the nanocomposites showed that when only 0.002 wt% of MoS2 was added to PS, it was possible to achieve an improvement of 27, 93.7, and 100% in the tensile strength, elongation at break, and toughness, respectively. Thermo-mechanical results indicated strong intermolecular and physical interactions between filler and polymer matrix contributing to effectiveness of the reinforcement. Very low number of agglomerates was observed by microtomography and Raman spectroscopy, mainly for the system with 0.002% wt.% of MoS2. The results proved that the use of bidimensional particles, even with ultralow content (<0.05 wt%), can improve the mechanical performance of polymeric matrices by a combination of well-done particle synthesis, right choice of processing strategy and good interaction between filler and matrix.

ZnO nanorods decorated with carbon nanodots and its metal doping as efficient photocatalyst for degradation of methyl blue solution

Abstract In this study, we report a facile and green chemistry technique to produce ZnO nanorods decorated with carbon nanodots (C-dots) to yield good photocatalytic for degradation of methyl blue. C-dots dispersed solution was obtained via simple carbonization of cassava peels at low temperature followed by ageing process for 6 days in absolute ethanol. The ZnO/C-dots heterostructure has been prepared by spin-coating C-dots dispersed solution onto ZnO nanorods surface. The impact of doping metal such as Co and Mn and the attachment of C-dots nanoparticles onto the surface of ZnO nanorods on their morphology, optical properties and photocatalytic activity were examined. The experimental results reveal that C-dots have successfully been attached onto the surface ZnO nanorods through strong physical interaction between C-dots and ZnO without modifying the morphology, surface area and crystallinity of ZnO nanorods. However, the energy bandgap of ZnO slightly decreases. This condition turns into increasing the charge separation efficiency of its electron-hole pairs which significantly enhances the visible light photocatalytic activity of the sample. The photodegradation rate of methyl blue was found to depend on the number of layers of C-dots. The Co doped ZnO nanorods coated with 4 layers C-dots particles was found to effectively degrade methyl blue solution compared to pristine ZnO nanorods. It is believed that high photocatalytic activity of metal doped ZnO/C-dots nanocomposite under UV light irradiation originates from their outstanding unique properties and the stimulated separation of photogenerated electron-hole pairs based on C-dots.

Abstract 2372: DUSP3-NPM-P53 axis: a new regulator of genomic stability of cells under genotoxic stress

Abstract The dual-specificity phosphatase 3 (DUSP3) is an atypical tyrosine phosphatase that dephosphorylates residues of p-Tyrosine and p-Threonine in protein substrates. DUSP3 is overexpressed in some human tumors, where it regulates cell cycle progression and has preferably nuclear localization. DUSP3 contributes to cellular genomic stability through mechanisms that begin to be clarified here. Our group used biochemical, bioinformatics, proteomics and interactome approaches to identify and validate nuclear proteins interacting with DUSP3 under cellular conditions of genotoxic stress promoted by UV-radiation. One of these targets is the nucleophosmin (NPM) protein, which plays key roles in nucleotide excision repair (NER) pathway. Surface Plasmon Resonance analyses showed a very strong physical bimolecular interaction between NPM-DUSP3. In order to verify the involvement of this phosphatase in DNA repair, DUSP3 knockdown was carried out in MRC-5 (normal fibroblasts) or XPA (NER-deficient cell line lacking the XPA protein) cell lines. By alkaline comet assays we found DUSP3 knockdown caused delay in DNA repair even in XPA cells, which is not to repair UV-radiation induced damage. This effect was supported by immuno-slot-blot assays specifically measuring the distortions of CPD and 6,4-photoproducts (6-4-PP) caused by UV-radiation on cells genome. Once again, MRC-5 cells DUSP3 silenced exhibited delay in the repair of these lesions, whereas XPA cells were not able to repair them even after 72h of the UVC exposure, but the accumulation of CPD and 6-4-PP lesions was even higher under DUSP3 silencing. Next we verify that NPM is a substrate of DUSP3 by immunoprecipitating tyrosine-phosphorylated NPM, and which levels are increased in both cells under DUSP3 knockdown. Using phospho-specific antibodies designed against the four tyrosine residues of NPM, immunoblotings revealed that DUSP3 specifically dephosphorylates tyrosine 29, 67 and 271 residues of NPM after UV radiation altering its subnuclear localization. Furthermore immunoblotting and imunofluorescence assays revealed an unexpected increase in phospho-p53-Ser15 and p53 transcriptional activity in DUSP3 deficient cells after exposure to UV radiation, which can be correlated to nuclear NPM functions in the repair of UV-promoted DNA lesions. Even so, we observed that DUSP3 knockdown also causes an earlier nucleolus-nucleoplasm translocation of NPM after genotoxic stress that is followed by an earlier ARF translocation and co-localization of both proteins with HDM2 and p53 at nucleoplasm. This leads to disruption of HDM2-p53 interaction, to non-degradation and earlier phosphorylation of p53-Ser15. Interestingly, using cycloheximide to inhibit protein synthesis, we confirmed that the half-life of p53 and NPM is longer in the DUSP3-deficient cells. Altogether our data highlight DUSP3 unknown roles in different signaling modules regulating biological processes involved in genomic stability through an unusual target, the NPM-p53 axis. Citation Format: Fábio L. Forti, Lilian C. Russo. DUSP3-NPM-P53 axis: a new regulator of genomic stability of cells under genotoxic stress [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2372.

Ultrastretchable, Self‐Healable, and Wearable Epidermal Sensors Based on Ultralong Ag Nanowires Composited Binary‐Networked Hydrogels

AbstractStretchable and biocompatible flexible electronic devices are essential to meet the increasing demands of complex and multifunctional personal healthcare systems. To detect various external stimuli, noninvasively epidermal sensors with reliable and sustainable performances are desirable. Herein, ultrastretchable, self‐healable, and wearable epidermal sensors based on ultralong Ag nanowires (AgNWs) composited binary‐networked hydrogels are fabricated. The flexible hydrogel sensors can monitor dynamic strains in a wide range (4–3000%), realize high healing efficiency (94.3%) and strong adhesiveness, which is attributed to the strong covalent bond and reversible physical interaction structured binary‐network. The ultralong AgNWs network remains in direct contact under strain, ensures a rapid response to external stimuli. The strong interactions between polymer matrix and the nanowires endow the hydrogel sensors excellent sensitivity (gauge factor of 4.59) within a wide sensing range (0–850%). The cycling stability of the hydrogel sensors is further improved by the composition of AgNWs, presenting negligible degradation both on tension and compression. Based on the advantageous performances, the flexible stain sensors can differentiate complicated human motions and realize phonation recognition precisely, showing promising application in next‐generation wearable epidermal sensors with ultrabroad working range and high sensitivity.

Theoretical insights into the performance of graphene derivatives, h-BN and BNC heterostructures in the adsorption and elimination of atrazine: An all-electron DFT study

The emergence of nanostructures with tunable chemical properties has triggered a great deal of interests in exploring their potential capabilities in adsorption processes. In this study, density functional theory (DFT) based calculations have been carried out to investigate the capability of three different hexagonal sheets namely: graphene and its defected form, h-BN and C-doped h-BN in the adsorption of atrazine molecule. These structures have been subjected to various analysis including molecular orbital interactions and energy calculations to unveil their affinity towards atrazine molecule and to understand the types as well as magnitude of their interactions with the guest molecule. The obtained results based on the adsorption energies and rotational as well as the translational energy barriers reveled that despite the existence of strong physical interactions between the involved fragments, however the mobility of adsorbed atrazine is strongly affected by the relatively low translational and rotational energy barriers for graphene monolayers while the polar bonds in hexagonal boron-nitride help in limiting the movement of atrazine. The nature of interactions between the involved molecules has also been taken into consideration and it was found that dispersion interactions play the main role in stabilizing the atrazine above the substrates. In addition, electrostatic attractions have also been found between the electronegative atoms of atrazine and electropositive boron atoms of boron-nitride. This favorable interaction further augments the stabilization of atrazine through compensating for the repulsive interactions between the highly localized electrons of N in the boron-nitride and the ring of atrazine.

A New Adenine-Derived Physical Dispersion System for Graphene/Polyimide Composites

In this work, combining experiment with molecular simulation, we share the result that the adenine moiety has strong physical interaction with graphene, providing a facile way to achieve a good dis...

New nanostructure based on hydroxyapatite modified cellulose for bone substitute, synthesis, and characterization

In the last decade calcium phosphate composites and other related biomaterials, were commercially used for bone substitution or allogrefts. In this study, a method was developed for purpose. In this composite hydroxyapatite (HAp) was placed in a cellulose structure by dissolving and precipitation technique. The produced biocompatible composites were extensively characterized by means of Fourier-transform infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, dynamic light scattering, and scanning electron microscopy. The analysis results showed that, Hap successfully included in cellulose network without affecting its crystallinity, or the properties of either cellulose or HAp. The analysis also revealed a strong physical interaction between the composite components. Therefore, the composite appears to be a useful for the fabrication of bioactive film that can be used in the Bone Tissue Engineering field. Novelty of this work is the synthesis of nanocomposites based on hydroxyapatite and cellulose to get nanomaterials by a new method of synthesis in organic chemistry, which is called the double decomposition method. This method creates patterns between the organic matrix and inorganic. The second object is to replace classical materials with new nanomaterials for medical and orthopedic uses.