Optoelectronic crystal of artificial atoms in strain-textured molybdenum disulphide

The isolation of the two-dimensional semiconductor molybdenum disulphide introduced a new optically active material possessing a band gap that can be facilely tuned via elastic strain. As an atomically thin membrane with exceptional strength, monolayer molybdenum disulphide subjected to biaxial strain can embed wide band gap variations overlapping the visible light spectrum, with calculations showing the modified electronic potential emanating from point-induced tensile strain perturbations mimics the Coulomb potential in a mesoscopic atom. Here we realize and confirm this ‘artificial atom’ concept via capillary-pressure-induced nanoindentation of monolayer molybdenum disulphide from a tailored nanopattern, and demonstrate that a synthetic superlattice of these building blocks forms an optoelectronic crystal capable of broadband light absorption and efficient funnelling of photogenerated excitons to points of maximum strain at the artificial-atom nuclei. Such two-dimensional semiconductors with spatially textured band gaps represent a new class of materials, which may find applications in next-generation optoelectronics or photovoltaics

Integrated analysis of genome-wide DNA methylation and cancer-associated fibroblasts identified prognostic biomarkers and immune checkpoint blockade in lower grade gliomas

BackgroundCancer-associated fibroblasts (CAFs) are vital components of prominent cellular components in lower-grade gliomas (LGGs) that contribute to LGGs’ progression, treatment resistance, and immunosuppression. Epigenetic modification and immunity have significant implications for tumorigenesis and development.MethodsWe combined aberrant methylation and CAFs abundances to build a prognostic model and the impact on the biological properties of LGGs. Grouping based on the median CAFs abundances score of samples in the TCGA-LGGs dataset, differentially expressed genes and aberrantly methylated genes were combined for subsequent analysis.ResultsWe identified five differentially methylated and expressed genes (LAT32, SWAP70, GSAP, EMP3, and SLC2A10) and established a prognostic gene signature validated in the CGGA-LGGs dataset. Immunohistochemistry (IHC) and in vitro tests were performed to verify these expressions. The high-risk group increased in tumor-promoting immune cells and tumor mutational burden. Notably, risk stratification had different ICB sensitivities in LGGs, and there were also significant sensitivity differences for temozolomide and the other three novel chemotherapeutic agents.ConclusionOur study reveals characteristics of CAFs in LGGs, refines the direct link between epigenetics and tumor stroma, and might provide clinical implications for guiding tailored anti-CAFs therapy in combination with immunotherapy for LGGs patients

Stromal protein CCN family contributes to the poor prognosis in lower-grade gioma by modulating immunity, matrix, stemness, and metabolism

Background: The CCN family of stromal proteins is involved in the regulation of many important biological functions. However, the role of dysregulated CCN proteins in lower-grade glioma (LGG) remain less understand.Methods: The clinical significance of the CCN proteins was explored based on RNA-seq profiles from multiple cohorts. A CCNScore was constructed using LASSO regression analysis. The PanCanAtlas data and MEXPRESS database were employed to elucidate molecular underpinnings.Results: The expression of CCN4 was associated with poor prognosis in LGG. The CCNScore (CCN1 = 0.06, CCN4 = 0.86) showed implication in prognosis prediction, subtype assessment and therapy selection. The gene mutation pattern of the high-CCNScore group was similar with glioblastoma, including EGFR, PTEN, and NF1 mutation frequently. Besides, the high-CCNScore group was comprised of samples mainly classic-like and mesenchymal-like, had lower methylation levels, higher stemness, higher inflammation, higher levels of extracellular matrix remodel and dysfunction of metabolic pathways. On the other hand, the low-CCNScore group consisted mainly of IDH-mutation LGG, and was characterized by TP53, CIC, and ATRX gene mutations, hyper-methylation status, lower stemness, lower proliferation, immune quietness and low extracellular matrix stiffness.Conclusion: In summary, these results outlined the role of CCN family in LGG and provided a potential and promising therapeutic target

Rapid progression of subcutaneous glioblastoma: A case report and literature review

Extra-neural spread of glioblastoma (GBM) is extremely rare. We report a case of postoperative intracranial GBM spreading to the subcutaneous tissue via the channel of craniotomy defect in a 73-year-old woman. Radiological images and histopathology indicate that the tumor microenvironment of the subcutaneous tumor is clearly different from the intracranial tumor. We also model the invasion of GBM cells through the dura-skull defect in mouse. The retrospective analysis of GBM with scalp metastases suggests that craniectomy is a direct cause of subcutaneous metastasis in patients with GBM. Imaging examinations of other sites for systemic screening is also recommended to look for metastases outside the brain when GBM invades the scalp or metastasizes to it

Design, fabrication, and measurement of microfluidic devices with integrated carbon nanotube sensors

Since the concept was first introduced in the early 1990s, lab-on-a-chip microsystems with integrated microfluidics and sensors have been widely used in the sensing field. At the same time, single-walled carbon nanotubes (SWCNTs) based nanosensors have attracted significant attention due to their extraordinary mechanical and electrical properties such as high conductivity, chemical stability, and good mechanical strength. Polymer microfluidic devices have received considerable attention due to their low cost, remarkable biocompatibility, and high flexibility when compared to glass and silicon devices. But the fabrication process of all-polymer microfluidics devices can be complicated and often requires a special group of techniques. In particular, different types of polymers possess different properties in terms of surface chemistry and hydrophilicity, making device assembly a challenging task. Moreover, the effective fabrication of labon-a-chip microsystems with integrated SWCNT-based sensors is still a challenge. In our research, we demonstrate the fabrication of an all-polymer microfluidic device through the investigation of the essential surface treatment methods. We also investigated a novel lab-on-a-chip device with integrated SWCNT nanosensors for glycerol concentration detection, which is an indirect indication of fluid viscosity. The device fabricated with photolithography and soft lithography methods enables real-time, in-channel measurements of the concentration of flowing aqueous glycerol solutions. The experimental results show that our device has a relatively high sensitivity for glycerol solutions. In order to demonstrate the functionality of our microfluidic devices and their potential in other fields, a multi-passage device was developed. In this device, a manifold was designed to create uniform flow in each parallel channel. This new device features a single feed passage of varying diameter, eliminating the excess volume from multiple branch steps. The design was validated with micro-particle image velocimetry (PIV), and the flow rates agreed to the order of the experimental uncertainty. Hence, the new device can provide a uniform flow distribution in a compact package, as is needed in microfluidic sensor applications

Advanced Bio-Based UV-Curable Anticorrosive Coatings Reinforced by hBN

Here, furfuryl methacrylate (FAM) was first successfully synthesized. Bulk hexagonal boron nitride (hBN) nanosheets were exfoliated and dispersed in FAM based on the strong pi-pi interaction between hBN and FAM. The few-layer hBN nanosheets as-prepared possessed an average thickness of similar to 3 nm (less than 10 layers) and exhibited superior storage stabilization under environment condition in FAM. Moreover, we creatively applied FAM solutions containing 0.25-0.75 wt% of hBN as reactive diluents for the epoxidized soybean oil methacrylate (ESOM) matrix to effectively enhance its corrosion protection by suppressing the penetration of aggressive species. The electrochemical results revealed that the impedance of the coating containing 0.75 wt. % hBN is similar to 200 times bigger than that of the blank coating specimen

Superior to graphene: super-anticorrosive natural mica nanosheets

Graphene has been generally considered to be the most ideal anticorrosive material based on its extraordinary impermeability, but tends in practical applications to promote metal corrosion because of its inherently high electrical conductivity. Mica nanosheets (MNSs), in contrast, display excellent electrical insulation properties, as well as excellent temperature stability and chemical durability, and show tremendous potential for protecting metals, and hence are a promising substitute for graphene. To date, however, there have been no reports about MNS-based anticorrosive coatings, since it is much more difficult to exfoliate high-quality MNSs than other layered materials. In this work, high-concentration (4.3 mg ml(-1)) ultrathin MNS (1-5 layers) dispersions were synthesized based on a facile and efficient hydrothermal exfoliation approach. Epoxy (EP) coatings were filled with the as-obtained MNSs to enhance the anticorrosion performance of the coatings, and their corrosion behaviors were studied systemically through a series of measurements. With the addition of only 0.4 wt% MNSs, the corrosion rate was observed to be reduced 6500 fold, and the coating impedance increased by four orders of magnitude compared with the blank EP coating. We believe that this method opens a novel avenue for developing high-performance anticorrosive coatings to replace graphene materials for metal protection

Variation of mechanical and thermal properties in sustainable graphene oxide/epoxy composites

In this work, the functional graphene oxide (bGO) was facilely synthesized through a grafted reaction between graphene oxide (GO) and bio-based bis-furan di-epoxide (BFDE). The structure of bGO was confirmed by FTIR spectra and Raman spectra. The properties of polymer composite materials depend on the distribution of the nanofiller in the matrix and due to the presence of polymer chains our bGO sheets exhibit a better dispersibility in solvents and polymer matrix, which provides a potential opportunity for the preparation of BFDE composites with excellent performance. Bio-based BFDE composites containing 0.05-0.5 wt.% of bGO exhibit superior mechanical and thermal properties. The addition of just 0.5 wt% such bGO to an BFDE causes 80%, 49%, 21%, 69% and 97% enhancement in tensile strength, flexural strength, flexural modulus, critical stress intensity factor and critical strain energy release rate, respectively. The thermal decomposition temperature T-d of bGO/BFDE composites was increased about similar to 17 degrees C compared to blank BFDE sample. In addition, we found that introducing unmodified GO to epoxy matrix lead to an insignificant increase of the thermal property of the resulting GO/BFDE composites. The enhanced mechanical properties and thermal properties of bGO/BFDE composites could be attributed to strong interfacial interactions and high affinity between bGO and epoxy matrix

The efficient exfoliation and dispersion of hBN nanoplatelets: advanced application to waterborne anticorrosion coatings

Although numerous papers have reported that graphene is a superior anticorrosion nanofiller, it has also been demonstrated that graphene cannot be used as a long-term anticorrosion barrier due to its essential high conductivity. Herein, an anticorrosive nanofiller (BNQDs@hBN) combining the nanomaterial boron nitride quantum dots (BNQDs) with insulating hexagonal boron nitride (hBN) is put forward. The homogeneous dispersion of BNQDs@hBN in an epoxy matrix was achieved with the assistance of BNQDs, and was based on strong - interactions between h-BN and BNQDs, as confirmed via UV-vis spectra. Embedding a small percentage of BNQDs@hBN in a waterborne epoxy (WEP) coating effectively improves the barrier properties of the coating by inhibiting the penetration of corrosive ions. Polarization tests revealed that the protection efficiency and corrosion rate of an epoxy coating with 0.5 wt% BNQDs@hBN were 99.99% and 6.482 x 10(-5) mm year(-1), respectively. Electrochemical impedance spectroscopy (EIS) results demonstrated that the 0.5 wt% BNQDs@hBN coating system showed a higher impedance modulus (>10(7)) than that of a blank specimen after immersion for 60 days in 3.5 wt% NaCl(aq)

Variation of mechanical and thermal properties in sustainable graphene oxide/epoxy composites

Variation of mechanical and thermal properties in sustainable graphene oxide/epoxy composite