Superhydrophobic Substrates from Off-The-Shelf Laboratory Filter Paper: Simplified Preparation, Patterning, and Assay Application

Off-the-shelf laboratory filter paper of different pore-sizes and thicknesses can be modified with fluorine-free organosilanes to be superhydrophobic, patternable, and ready for quantitative assay applications. In particular, we have demonstrated that cellulose filter paper treated with a binary hexane solution of short (methyltrichlorosilane, MTS) and long (octadecyltrichlorosilane, OTS) organosilanes, exhibits remarkably high water contact angles (> 150 °) and low wetting hysteresis (~10 °). Beyond the optimized ratio between the two organosilanes, we have discovered that the thickness rather than the pore size dictates the resulting superhydrophobicity. Scanning electron microscope (SEM) images showed that silianization does not damage the cellulose microfibers; instead they are coated with uniform, particulate nanostructures, which should contribute to the observed surface properties. The modified filter paper is chemically stable and mechanically durable; it can be readily patterned with UV/ozone treatment to create hydrophilic regions to prepare chemical assays for colorimetric pH and nitrite detections

Integrated Smartphone-App-Chip System for On-Site Ppb-Level Colorimetric Quantitation of Aflatoxins

We demonstrate herein an integrated, smartphone-app-chip (SPAC) system for on-site quantitation of food toxins, as demonstrated with aflatoxin B1 (AFB1), at parts-per-billion (ppb) level in food products. The detection is based on an indirect competitive immunoassay fabricated on a transparent plastic chip with the assistance of a microfluidic channel plate. A 3D-printed optical accessory attached to a smartphone is adapted to align the assay chip and to provide uniform illumination for imaging, with which high-quality images of the assay chip are captured by the smartphone camera and directly processed using a custom-developed Android app. The performance of this smartphone-based detection system was tested using both spiked and moldy corn samples; consistent results with conventional ELISA kits were obtained. The achieved detection limit (3±1 μg/kg, equivalent to ppb) and dynamic response range (0.5−250 μg/kg) meet the requested testing standards set by authorities worldwide. We envision that the integrated SPAC system promises to be a simple and accurate method of food toxin quantitation, bringing much benefit for rapid on-site screening

Observation of the chiral anomaly induced negative magneto-resistance in 3D Weyl semi-metal TaAs

Weyl semi-metal is the three dimensional analog of graphene. According to the quantum field theory, the appearance of Weyl points near the Fermi level will cause novel transport phenomena related to chiral anomaly. In the present paper, we report the first experimental evidence for the long-anticipated negative magneto-resistance generated by the chiral anomaly in a newly predicted time-reversal invariant Weyl semi-metal material TaAs. Clear Shubnikov de Haas oscillations (SdH) have been detected starting from very weak magnetic field. Analysis of the SdH peaks gives the Berry phase accumulated along the cyclotron orbits to be {\pi}, indicating the existence of Weyl points.Comment: Submitted in February'1

The Effect of the External Magnetic Field on the Initial Impulse Attribute for Magnetostrictive Sensors

Magnetostrictive sensors (MsSs) using the magnetostriction effect have many advantages for nondestructive inspections, such as without any contact, movable and easily installed. While the shortcoming of MsSs, for example low SNR and the output affected by the nonlinear magneto-mechanical coupling performance under magnetic field, can limit the use of it. In order to solve this problem, the mechanical dynamics model to excite guided-wave was established which was based on the nonlinear coupled magnetostrictive theory of ferromagnetic material and the generator model of magnetostrictive guided-wave. Using the finite element method (FEM) and numerical simulation, the effect of the bias magnetic field, exciting frequency and exciting current on the particle amplitude were analyzed. The results indicate that the low frequency, heavy current and suitable bias magnetic field can improve the conversion efficiency of magneto-mechanical coupling performance under the condition of considering dispersion. The suitable bias magnetic field is determined by the maximum tangent slope of the amplitude curve

Role of CTSC in Glioblastoma Based on Oncomine and TCGA Database

Background and objective Glioblastoma (GBM) is one of the malignant tumors causing death worldwide. Most patients were found in the middle and late stages and had poor prognosis. The purpose of this study was to investigate the expression and significance of CTSC in GBM. Methods The information about CTSC in Oncomine database was collected and analyzed twice. The role of CTSC in GBM was meta-analyzed. The expression of CTSC in glioma cell lines was retrieved by CCLE database, and the survival of patients was analyzed by TCGA database. Results A total of 1,459 different types of CTSC were collected in Oncomine database, 134 of which had statistical differences in CTSC expression, 89 of which had increased CTSC expression and 45 of which had decreased CTSC expression. A total of 50 studies involving the expression of CTSC in GBM cancer and normal tissues included 1,189 samples. Compared with the control group, CTSC was highly expressed in GBM (P < 0.05). Moreover, CTSC was highly expressed in glioma cell lines. There was a correlation between the expression of CTSC and the overall survival rate of GBM. The overall survival rate of patients with high expression of CTSC was worse, while the prognosis of patients with low expression of SPC24 was better (P < 0.05). Conclusion Through the in-depth mining of oncomine gene chip database, we propose that CTSC is highly expressed in GBM tissues and is related to the prognosis of GBM, which may provide an important theoretical basis for the treatment of glioma

Binary Silanization and Silver Nanoparticle Encapsulation to Create Superhydrophobic Cotton Fabrics with Antimicrobial Capability

Cotton fabrics are functionalized with a binary solution of fluorine-free organosilanes and “encapsulated” with silver nanoparticles to achieve both superhydrophobic and antimicrobial properties. Derived from cellulose, cotton is one of the most abundant biologically generated materials and has been used in a wide variety of consumer goods. Nonetheless, cotton fabrics are not waterproof and prone to microbial contamination. Herein we report the rapid functionalization of cotton fabrics with a binary hexane solution of methyltrichlorosilane (MTS) and octadecyltrichlorosilane (OTS) at low concentration (0.17% v/v) followed by coating with colloidal silver nanoparticles (AgNP). The combined effects of binary silanization and AgNP encapsulation produced a surface that has remarkable water contact angle of 153 ± 2° and antimicrobial properties (against gram-negative Escherichia coli). The superior performance of the modified cotton fabrics produced with fluorine-free organosilanes and silver nanoparticles augments the potential of improving the functionality of abundant biopolymers to be waterproof and contamination-resistant

Digitized Molecular Detection on Off-the-shelf Blu-ray Discs: Upgraded Resolution and Enhanced Sensitivity

Beyond the intrinsic capability of storing and archiving high-definition movies and games, off-the-shelf Blu-ray discs have been adopted for the preparation of molecular binding assays, which are subsequently read and quantitated with a standard computer drive in conjunction with the disc-quality check program. The performance of this digitized molecular detection system has been examined first with an artificial “ink assay” (an array of microsize ink dots) to define the quantitation capability and the lateral resolution; the conventional biotin-streptavidin binding assay was then tested with the Blu-ray detection platform, and the results compared with that obtained on a DVD. The upgraded lateral resolution (<100 μm) and enhanced assay performance (linear response up to 0.4 μg/mL and LOD estimated to be >< 0.1 μg/mL for the trial biotin-streptavidin system augments its potential to be adapted as a cost-effective and quantitative diagnostic tool for on-site analysis and point-of-care medical diagnosis at trace amounts

Inhibition of CLIC4 Enhances Autophagy and Triggers Mitochondrial and ER Stress-Induced Apoptosis in Human Glioma U251 Cells under Starvation

CLIC4/mtCLIC, a chloride intracellular channel protein, localizes to mitochondria, endoplasmic reticulum (ER), nucleus and cytoplasm, and participates in the apoptotic response to stress. Apoptosis and autophagy, the main types of the programmed cell death, seem interconnected under certain stress conditions. However, the role of CLIC4 in autophagy regulation has yet to be determined. In this study, we demonstrate upregulation and nuclear translocation of the CLIC4 protein following starvation in U251 cells. CLIC4 siRNA transfection enhanced autophagy with increased LC3-II protein and puncta accumulation in U251 cells under starvation conditions. In that condition, the interaction of the 14-3-3 epsilon isoform with CLIC4 was abolished and resulted in Beclin 1 overactivation, which further activated autophagy. Moreover, inhibiting the expression of CLIC4 triggered both mitochondrial apoptosis involved in Bax/Bcl-2 and cytochrome c release under starvation and endoplasmic reticulum stress-induced apoptosis with CHOP and caspase-4 upregulation. These results demonstrate that CLIC4 nuclear translocation is an integral part of the cellular response to starvation. Inhibiting the expression of CLIC4 enhances autophagy and contributes to mitochondrial and ER stress-induced apoptosis under starvation