Preparation and Properties of Chitosan/Graphene Modified Bamboo Fiber Fabrics

Chitosan (CS) and graphene (Gr) were used to modify bamboo fiber fabrics to develop new bamboo fiber fabrics (CGBFs) with antimicrobial properties. The CGBFs were prepared by chemical crosslinking with CS as binder assistant and Gr as functional finishing agent. The method of firmly attaching the CS/Gr to bamboo fiber fabrics was explored. On the basis of the constant amount of CS, the best impregnation modification scheme was determined by changing the amount of Gr and evaluating the properties of the CS/Gr modified bamboo fiber fabrics. The results showed that the antibacterial rate of CGBFs with 0.3 wt% Gr was more than 99%, and compared with the control sample, the maximum tensile strength of CGBF increased by 1% in the longitudinal direction and 7.8% in the weft direction. The elongation at break increased by 2.2% in longitude and 57.3% in latitude. After 20 times of washing with WOB (without optical brightener) detergent solution, the antimicrobial rate can still be more than 70%. Therefore, these newly CS/Gr modified bamboo fiber fabrics hold great promise for antibacterial application in home decoration and clothing textiles

Methods for Solving Finite Element Mesh-Dependency Problems in Geotechnical Engineering—A Review

The instabilities of soil specimens in laboratory or soil made geotechnical structures in field are always numerically simulated by the classical continuum mechanics-based constitutive models with finite element method. However, finite element mesh dependency problems are inevitably encountered when the strain localized failure occurs especially in the post-bifurcation regime. In this paper, an attempt is made to summarize several main numerical regularization techniques used in alleviating the mesh dependency problems, i.e., viscosity theory, nonlocal theory, high-order gradient and micropolar theory. Their fundamentals as well as the advantages and limitations are presented, based on which the combinations of two or more regularization techniques are also suggested. For all the regularization techniques, at least one implicit or explicit parameter with length scale is necessary to preserve the ellipticity of the partial differential governing equations. It is worth noting that, however, the physical meanings and their relations between the length parameters in different regularization techniques are still an open question, and need to be further studied. Therefore, the micropolar theory or its combinations with other numerical methods are promising in the future

Peptide-Directed Hierarchical Mineralized Silver Nanocages for Anti-Tumor Photothermal Therapy

The size and morphology of metals determine their plasmon resonances. How to elegantly tune their architectures to obtain optical properties as required (e.g., strong absorption in the near infrared (NIR) wavelengths) is a bottleneck for phototherapy. Inspired by biomineralization, we develop a simple but robust strategy to fabricate silver nanocages (Ag NCs) based on peptide-directed mineralization of silver. The Ag NCs are organic-inorganic hybrids with octreotide (OCT) templated decoration of Ag shells that are composed of Ag NPs. This hierarchical organization makes Ag NPs get together in close proximity, which facilitates ultrastrong plasmonic coupling to shift the resonant excitation from the visible (420 nm) to the NIR region (810 nm). In addition, the surface plasmon resonance peak of the Ag NCs in the NIR region can be subtly tuned by varying the volume of added silver nitrate (AgNO3) to control the size and morphology of mineralized Ag NCs. The Ag NCs have a light-to-heat conversion efficiency of 46.1%, which is to our knowledge the highest among Ag-based photothermal agents (PTAs). The Ag NCs can selectively induce death of cancer cells in vitro under NIR irradiation at 808 nm and show improved cytocompatibility for normal cells relative to pure Ag NPs. Following intratumor injection into uterine cervix cancer cells (U14) tumor-bearing mice, Ag NCs exert remarkable antitumor performance with tumor killing efficacy up to 82.7% and good biocompatibility in photothermal therapy, suggesting their potential application to work as photothermal nanomedicine for cancer therapy.</p

Peptide-Directed Hierarchical Mineralized Silver Nanocages for Anti-Tumor Photothermal Therapy

The size and morphology of metals determine their plasmon resonances. How to elegantly tune their architectures to obtain optical properties as required (e.g., strong absorption in the near-infrared (NIR) wavelengths) is a bottleneck for phototherapy. Inspired by biomineralization, we develop a simple but robust strategy to fabricate silver nanocages (Ag NCs) based on peptide-directed mineralization of silver. The Ag NCs are organic–inorganic hybrids with octreotide (OCT) templated decoration of Ag shells that are composed of Ag NPs. This hierarchical organization makes Ag NPs get together in close proximity, which facilitates ultrastrong plasmonic coupling to shift the resonant excitation from the visible (420 nm) to the NIR region (810 nm). In addition, the surface plasmon resonance peak of the Ag NCs in the NIR region can be subtly tuned by varying the volume of added silver nitrate (AgNO₃) to control the size and morphology of mineralized Ag NCs. The Ag NCs have a light-to-heat conversion efficiency of 46.1%, which is to our knowledge the highest among Ag-based photothermal agents (PTAs). The Ag NCs can selectively induce death of cancer cells <i>in vitro</i> under NIR irradiation at 808 nm and show improved cytocompatibility for normal cells relative to pure Ag NPs. Following intratumor injection into uterine cervix cancer cells (U14) tumor-bearing mice, Ag NCs exert remarkable antitumor performance with tumor killing efficacy up to 82.7% and good biocompatibility in photothermal therapy, suggesting their potential application to work as photothermal nanomedicine for cancer therapy

Chemical-induced phase transition and global conformational reorganization of chromatin

Abstract Chemicals or drugs can accumulate within biomolecular condensates formed through phase separation in cells. Here, we use super-resolution imaging to search for chemicals that induce phase transition within chromatin at the microscale. This microscopic screening approach reveals that adriamycin (doxorubicin) — a widely used anticancer drug that is known to interact with chromatin — specifically induces visible local condensation and global conformational change of chromatin in cancer and primary cells. Hi-C and ATAC-seq experiments systematically and quantitatively demonstrate that adriamycin-induced chromatin condensation is accompanied by weakened chromatin interaction within topologically associated domains, compartment A/B switching, lower chromatin accessibility, and corresponding transcriptomic changes. Mechanistically, adriamycin complexes with histone H1 and induces phase transition of H1, forming fibrous aggregates in vitro. These results reveal a phase separation-driven mechanism for a chemotherapeutic drug