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A material that rapidly absorbs molecular oxygen (known as an oxygen scavenger or deoxygenation agent (DOA)) has various industrial applications, such as in food preservation, anticorrosion of metal and coal deoxidation. Given that oxygen is vital to cancer growth, to starve tumours through the consumption of intratumoral oxygen is a potentially useful strategy in fighting cancer. Here we show that an injectable polymer-modified magnesium silicide (Mg 2 Si) nanoparticle can act as a DOA by scavenging oxygen in tumours and form by-products that block tumour capillaries from being reoxygenated. The nanoparticles are prepared by a self-propagating high-temperature synthesis strategy. In the acidic tumour microenvironment, the Mg 2 Si releases silane, which efficiently reacts with both tissue-dissolved and haemoglobin-bound oxygen to form silicon oxide (SiO 2 ) aggregates. This in situ formation of SiO 2 blocks the tumour blood capillaries and prevents tumours from receiving new supplies of oxygen and nutrients. Magnesium silicide nanoparticles can scavenge oxygen in the acidic tumour microenvironment and starve tumours by blocking oxygen and nutrient supply, offering a new avenue for cancer-starvation therapy.

BACKGROUND: The incorporation of silica within the plant cell wall has been well documented by botanists and materials scientists; however, the means by which plants are able to transport silicon and control its polymerization, together with the roles of silica in situ, are not fully understood. RECENT PROGRESS: Recent studies into the mechanisms by which silicification proceeds have identified the following: an energy-dependent Si transporter; Si as a biologically active element triggering natural defence mechanisms; and the means by which abiotic toxicities are alleviated by silica. A full understanding of silica formation in vivo still requires an elucidation of the role played by the environment in which silica formation occurs. Results from in-vitro studies of the effects of cell-wall components associated with polymerized silica on mineral formation illustrate the interactions occurring between the biomolecules and silica, and the effects their presence has on the mineralized structures so formed. SCOPE: This Botanical Briefing describes the uptake, storage and function of Si, and discusses the role biomolecules play when incorporated into model systems of silica polymerization as well as future directions for research in this field.

While the reciprocity between bioceramics and living cells is complex, it is principally governed by the implant’s surface chemistry. Consequently, a deeper understanding of the chemical interactions of bioceramics with living tissue could ultimately lead to new therapeutic strategies. However, the physical and chemical principles that govern these interactions remain unclear. The intricacies of this biological synergy are explored within this paper by examining the peculiar surface chemistry of a relatively new bioceramic, silicon nitride (Si 3 N 4 ). Building upon prior research, this paper aims at obtaining new insights into the biological interactions between Si 3 N 4 and living cells, as a consequence of the off-stoichiometric chemical nature of its surface at the nanometer scale. We show here yet unveiled details of surface chemistry and, based on these new data, formulate a model on how, ultimately, Si 3 N 4 influences cellular signal transduction functions and differentiation mechanisms. In other words, we interpret its reciprocity with living cells in chemical terms. These new findings suggest that Si 3 N 4 might provide unique new medicinal therapies and effective remedies for various bone or joint maladies and diseases.

Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, iron sulfides, amorphous material, and trioctahedral smectites. The John Klein smectite has basal spacing of ~10 angstroms, indicating little interlayer hydration. The Cumberland smectite has basal spacing at both ~13.2 and ~10 angstroms. The larger spacing suggests a partially chloritized interlayer or interlayer magnesium or calcium facilitating H 2 O retention. Basaltic minerals in the mudstone are similar to those in nearby eolian deposits. However, the mudstone has far less Fe-forsterite, possibly lost with formation of smectite plus magnetite. Late Noachian/Early Hesperian or younger age indicates that clay mineral formation on Mars extended beyond Noachian time.

Waveguide-based photonic sensors provide a unique combination of high sensitivity, compact size and label-free, multiplexed operation. Interferometric configurations furthermore enable a simple, fixed-wavelength read-out making them particularly suitable for low-cost diagnostic and monitoring devices. Their limit of detection, i.e., the lowest analyte concentration that can be reliably observed, mainly depends on the sensors response to small refractive index changes, and the noise in the read-out system. While enhancements in the sensors response have been extensively studied, noise optimization has received much less attention. Here we show that order-of-magnitude enhancements in the limit of detection can be achieved through systematic noise reduction, and demonstrate a limit of detection of ∼ 10 − 8 RIU with a silicon nitride sensor operating at telecom wavelengths.

Silicon has been widely used as a material for microelectronic for more than 60 years, attracting considerable scientific interest as a promising tool for the manufacture of implantable medical devices in the context of neurodegenerative diseases. However, the use of such material involves responsibilities due to its toxicity, and researchers are pushing towards the generation of new classes of composite semiconductors, including the Silicon Carbide (3C-SiC). In the present work, we tested the biocompatibility of Silicon and 3C-SiC using an in vitro model of human neuronal stem cells derived from dental pulp (DP-NSCs) and mouse Olfactory Ensheathing Cells (OECs), a particular glial cell type showing stem cell characteristics. Specifically, we investigated the effects of 3C-SiC on neural cell morphology, viability and mitochondrial membrane potential. Data showed that both DP-NSCs and OECs, cultured on 3C-SiC, did not undergo consistent oxidative stress events and did not exhibit morphological modifications or adverse reactions in mitochondrial membrane potential. Our findings highlight the possibility to use Neural Stem Cells plated on 3C-SiC substrate as clinical tool for lesioned neural areas, paving the way for future perspectives in novel cell therapies for neuro-degenerated patients.

This study was conducted to investigate effects of modified palygorskite (MPal) supplementation on the laying performance, egg quality and mineral element content, immunity, oxidative status, and intestinal integrity and barrier function of laying hens. A total of 360 52-week-old Hyline Brown hens were randomly assigned into four dietary treatments for a 7-week feeding trial. The birds were fed a basal diet supplemented with 0 (control group), 0.25, 0.5, and 1 g/kg MPal, respectively. The supplementation of MPal did not alter laying performance and egg quality among groups. Compared with the control group, MPal inclusion decreased lead (Pb) content in yolks at 49 days, and either 0.5- or 1-g/kg MPal supplementation decreased Pb accumulation in yolks at 25 days and manganese (Mn) accumulation in yolks at 25 and 49 days. The contents of jejunal secretory immunoglobulin A (SIgA), ileal SIgA, and immunoglobulin G were decreased by the dietary 0.5-g/kg MPal supplementation. The supplementation of MPal also decreased malondialdehyde content in jejunum and ileum, and decreased serum diamine oxidase activity of the laying hens at 25 and 49 days. The inclusion of 0.5 and 1 g/kg MPal enhanced villus height in jejunum and ileum, and also increased the ratio of villus height to crypt depth in ileum. In conclusion, MPal supplementation decreased Pb and Mn contents in yolks, and exhibited beneficial effects on the intestinal immunity, oxidative status, and intestinal integrity and barrier function of laying hens and its optimal dosage was 0.5 g/kg.

It has been demonstrated that nanocrystalline forsterite powder synthesised using urea as a fuel in sol-gel combustion method had produced a pure forsterite (FU) and possessed superior bioactive characteristics such as bone apatite formation and antibacterial properties. In the present study, 3D-scaffold was fabricated using nanocrystalline forsterite powder in polymer sponge method. The FU scaffold was used in investigating the physicochemical, biomechanics, cell attachment, in vitro biocompatibility and osteogenic differentiation properties. For physicochemical characterisation, Fourier-transform infrared spectroscopy (FTIR), Energy dispersive X-ray (EDX), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoemission spectrometer (XPS) and Brunauer-Emmett-Teller (BET) were used. FTIR, EDX, XRD peaks and Raman spectroscopy demonstrated correlating to FU. The XPS confirmed the surface chemistry associating to FU. The BET revealed FU scaffold surface area of 12.67 m2/g and total pore size of 0.03 cm3/g. Compressive strength of the FU scaffold was found to be 27.18 ± 13.4 MPa. The human bone marrow derived mesenchymal stromal cells (hBMSCs) characterisation prior to perform seeding on FU scaffold verified the stromal cell phenotypic and lineage commitments. SEM, confocal images and presto blue viability assay suggested good cell attachment and proliferation of hBMSCs on FU scaffold and comparable to a commercial bone substitutes (cBS). Osteogenic proteins and gene expression from day 7 onward indicated FU scaffold had a significant osteogenic potential (p<0.05), when compared with day 1 as well as between FU and cBS. These findings suggest that FU scaffold has a greater potential for use in orthopaedic and/or orthodontic applications.

Graphene nanoribbons combine the unique electronic and spin properties of graphene 1 , 2 with a transport gap that arises from quantum confinement and edge effects 3 , 4 , 5 , 6 . This makes them an attractive candidate material for the channels of next-generation transistors. Nanoribbons can be made in a variety of ways, including lithographic 7 , 8 , 9 , chemical 10 , 11 , 12 and sonochemical 6 approaches, the unzipping of carbon nanotubes 13 , 14 , 15 , 16 , 17 , the thermal decomposition of SiC 18 and organic synthesis 19 . However, the reliable site and alignment control of nanoribbons with high on/off current ratios 20 remains a challenge. Here we control the site and alignment of narrow (∼23 nm) graphene nanoribbons by directly converting a nickel nanobar into a graphene nanoribbon using rapid-heating plasma chemical vapour deposition. The nanoribbons grow directly between the source and drain electrodes of a field-effect transistor without transfer, lithography and other postgrowth treatments, and exhibit a clear transport gap (58.5 meV), a high on/off ratio (>10 4 ) and no hysteresis. Complex architectures, including parallel and radial arrays of supported and suspended ribbons, are demonstrated. The process is scalable and completely compatible with existing semiconductor processes, and is expected to allow integration of graphene nanoribbons with silicon technology. Graphene nanoribbons with a clear transport gap and high on/off ratio are grown directly into complex architectures using plasma chemical vapour deposition onto lithographically defined nickel nanobar substrates.

Nanopore sensor technology is widely used in biomolecular detection due to its advantages of low cost and easy operation. In a variety of nanopore manufacturing methods, controlled dielectric breakdown has the advantages of a simple manufacturing process and low cost under the premise of ensuring detection performance. In this paper, we have made enhancements to the applied pulses in controlled dielectric breakdown and utilized the improved dielectric breakdown technique to fabricate silicon nitride nanopores with diameters of 5 to 15 nm. Our improved fabrication method offers the advantage of precise control over the nanopore diameter (±0.4 nm) and enhances the symmetry of the nanopore. After fabrication, we performed electrical characterization on the nanopores, and the IV characteristics exhibited high linearity. Subsequently, we conducted detection experiments for DNA and protein using the prepared nanopores to assess the detection performance of the nanopores fabricated using our method. In addition, we also give a physical model of molecule translocation through the nanopores to give a reasonable explanation of the data processing results.