Mechanical and Morphological Analysis of Cancer Cells on Nanostructured Substrates.

Cancer metastasis is a major cause of cancer-induced deaths in patients. Mimicking nanostructures of an extracellular matrix surrounding cancer cells can provide useful clues for metastasis. This paper compares the morphology, proliferation, spreading, and stiffness of highly aggressive glioblastoma multiforme cancer cells and normal fibroblast cells seeded on a variety of ordered polymeric nanostructures (nanopillars and nanochannels). Both cell lines survive and proliferate on the nanostructured surface and show more similarity on nanostructured surfaces than on flat surfaces. Although both show similar stiffness on the nanochannel surface, glioblastomas are softer, spread to a larger area, and elongate less than fibroblasts. The nanostructured surfaces are useful for in vitro model of an extracellular matrix to study the cancer cell migratory phenotype.

Enhanced magnetism in highly ordered magnetite nanoparticle-filled nanohole arrays.

A new approach to develop highly ordered magnetite (Fe3O4) nanoparticle-patterned nanohole arrays with desirable magnetic properties for a variety of technological applications is presented. In this work, the sub-100 nm nanohole arrays are successfully fabricated from a pre-ceramic polymer mold using spin-on nanoprinting (SNAP). These nanoholes a then filled with monodispersed, spherical Fe3O4 nanoparticles of about 10 nm diameter using a novel magnetic drag and drop procedure. The nanohole arrays filled with magnetic nanoparticles a imaged using magnetic force microscopy (MFM). Magnetometry and MFM measurements reveal room temperature ferromagnetism in the Fe3O4-filled nanohole arrays, while the as-synthesized Fe3O4 nanoparticles exhibit superparamagnetic behavior. As revealed by MFM measurements, the enhanced magnetism in the Fe3O4-filled nanohole arrays originates mainly from the enhanced magnetic dipole interactions of Fe3 O4 nanoparticles within the nanoholes and between adjacent nanoholes. Nanoparticle filled nanohole arrays can be highly beneficial in magnetic data storage and other applications such as microwave devices and biosensor arrays that require tunable and anisotropic magnetic properties.

Spectroscopic ellipsometry on metal and metal-oxide multilayer hybrid plasmonic nanostructures.

The effective medium approximation is used to determine the optical constants of novel silver (Ag)/indium-tin oxide (ITO) multilayer nanopillar structures within the 300-800 nm wavelength range. The structures are modeled as inclusions in air with the pillar volume fraction at 42.4%, agreeing with SEM images of the sample. The simulated reflection intensity of the nanopillars is much less than that of the planar reference sample and is a result of the small difference between the refractive index of the top effective medium layer and that of air. Furthermore, the minimum in the reflection at around 450 nm in the nanostructured sample is evidence of surface plasmon enhancement, indicating suitability for plasmonic applications. The simulated Brewster angle decreases in the pillar region, which is an indication of smaller effective refractive index.

Effect of modular diffraction gratings on absorption in P3HT:PCBM layers.

Various gratings with 700 nm feature spacings are patterned on the reverse side of organic solar cell active layers to increase the path length and constrain light to the cell through total internal reflection. The absorption enhancement is studied for 15, 40, and 120 nm active layers. We were able to confine 9% of the incident light over the wavelength range of 400-650 nm, with thinner gratings having a greater enhancement potential. The measurement setup utilizing an integrating sphere to fully characterize scattered or diffracted light is also fully described.

Molecular characterization of Cryptosporidium in native beef calves in central Vietnam.

The aims of this study were to investigate the prevalence of Cryptosporidium and to characterize the genotype distribution of Cryptosporidium isolates in native beef calves 2-6 months old in Dac Lac province, central Vietnam. The presence of Cryptosporidium oocysts was determined using the modified Ziehl-Neelsen staining method. The overall prevalence on the sample and herd levels were 18.9% (44/232) and 50% (20/40), respectively. Genotyping based on PCR and sequence analysis of the 18 S rRNA gene revealed occurrence of the two nonzoonotic species Cryptosporidium ryanae and Cryptosporidium bovis, with the former as a dominant species in the animals. The absence of the zoonotic species Cryptosporidium parvum in calves examined suggests that the native beef calves 2-6 months old in the study area are unlikely to contribute to human cryptosporidiosis transmission.

Stability of the knee after posterior cruciate ligament reconstruction using peroneus longus tendon graft with three femoral insertion sites. A cadaveric study.

Introduction: Many kinds of grafts were used for single-bundle reconstruction of the posterior cruciate ligament (PCL). Recently, the peroneus longus tendon (PLT) was used in some clinical reports. This study aimed to test the best position of the femoral insertion in the case of using PLT for PCL reconstruction. Methods: Seventeen fresh frozen cadaveric knees were randomized into three groups. Group AL (6 knees): the femoral insertion in PCL reconstruction was at the footprint center of the anterolateral bundle (ALB). Group PM (5 knees): at the footprint center of the posteromedial bundle (PMB). And group MC (6 knees) was at the midpoint of the center of the anterolateral bundle and posteromedial bundle. The PCL of all knees was cut and a PCL reconstruction procedure was performed with autologous peroneus longus tendon (PLT). The stability of each knee was tested in three conditions: PCL was intact, PCL was resected, and PCL was reconstructed. The KT-1000 machine was used to measure the maximum posterior displacement of the tibia under force with the knees at 0, 30, 60, 90, and 120 degrees of flexion. Results: Average posterior displacement of the tibia under force for intact PCL of group AL was 1.6 mm, group MC was 1.2 mm, and group PM was 1.3 mm. After PCL was resected, the knee laxity was increased remarkably: posterior displacement of the tibia of group AL was 8.9 mm, group MC was 9.4 mm, and group PM was 13.6 mm. After PCL was reconstructed, group AL was 1.5 mm, group MC was 2.0 mm, and group PM was 5.6 mm. The results showed that after PCL reconstruction the group AL and group MC give better stability to the knee (p < 0.05, except knee at 120 degrees of flexion). Group AL got more stability than group MC, but the difference was not significant (p ≥ 0.164). Conclusion: In a single-bundle reconstruction of the PCL with the graft PLT, the femoral insertion at the footprint center of the ALB and the midpoint of the center of the ALB and PMB showed better stability than that at PMB.

Outcomes of bone marrow mononuclear cell transplantation combined with interventional education for autism spectrum disorder.

The aim of this study was to evaluate the safety and efficacy of autologous bone marrow mononuclear cell transplantation combined with educational intervention for children with autism spectrum disorder. An open-label clinical trial was performed from July 2017 to August 2019 at Vinmec International Hospital, Hanoi, Vietnam. Thirty children who fulfilled the autism criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and had Childhood Autism Rating Scale (CARS) scores >37 were selected. Bone marrow was harvested by anterior iliac crest puncture under general anesthesia. The volume collected was as follows: 8 mL/kg for patients under 10 kg (80 mL + [body weight in kg - 10] × 7 mL) for patients above 10 kg. Mononuclear cells were isolated with a Ficoll gradient and then infused intrathecally. The same procedure was repeated 6 months later. After the first transplantation, all patients underwent 8 weeks of educational intervention based on the Early Start Denver Model. There were no severe adverse events associated with transplantation. The severity of autism spectrum disorder (ASD) was significantly reduced, with the median CARS score decreasing from 50 (range 40-55.5) to 46.5 (range 33.5-53.5) (P < .05). Adaptive capacity increased, with the median Vineland Adaptive Behavior Scales score rising from 53.5 to 60.5. Social communication, language, and daily skills improved markedly within 18 months after transplantation. Conversely, repetitive behaviors and hyperactivity decreased remarkably. Autologous bone marrow mononuclear cell transplantation in combination with behavioral intervention was safe and well tolerated in children with ASD (Trial registration: ClinicalTrials.gov identifier: NCT03225651).

Low-Temperature Processed TiOx/Zn1-xCdxS Nanocomposite for Efficient MAPbIxCl1-x Perovskite and PCDTBT:PC70BM Polymer Solar Cells.

The majority of high-performance perovskite and polymer solar cells consist of a TiO2 electron transport layer (ETL) processed at a high temperature (>450 °C). Here, we demonstrate that low-temperature (80 °C) ETL thin film of TiOx:Zn1-xCdxS can be used as an effective ETL and its band energy can be tuned by varying the TiOx:Zn1-xCdxS ratio. At the optimal ratio of 50:50 (vol%), the MAPbIxCl1-x perovskite and PCBTBT:PC70BM polymer solar cells achieved 9.79% and 4.95%, respectively. Morphological and optoelectronic analyses showed that tailoring band edges and homogeneous distribution of the local surface charges could improve the solar cells efficiency by more than 2%. We proposed a plausible mechanism to rationalize the variation in morphology and band energy of the ETL.

Organic Phase Change Nanoparticles for in-Product Labeling of Agrochemicals.

There is an urgent need to develop in-product covert barcodes for anti-counterfeiting of agrochemicals. This paper reports a new organic nanoparticle-based in-product barcode system, in which a panel of organic phase change nanoparticles is added as a barcode into in a variety of chemicals (herein agrochemicals). The barcode is readout by detecting melting peaks of organic nanoparticles using differential scanning calorimetry. This method has high labeling capacity due to small sizes of nanoparticles, sharp melting peaks, and large scan range of thermal analysis. The in-product barcode can be effectively used to protect agrochemical products from being counterfeited due to its large coding capacity, technical readiness, covertness, and robustness.

Nanomaterial-based barcodes.

Two-dimensional (2D) barcodes ubiquitously used to label, track and authenticate objects face increasing challenges of being damaged, altered and falsified. The past effort in nanomaterials has paved the way for controlled synthesis of nanomaterials with desired size, shape and function. Due to their extremely small sizes, these nanomaterials are promising as next generation barcodes that can be added into or mixed with objects of interest without being noticed. These barcodes can be effectively read owing to their physical properties by manufacturers, law enforcement and security agencies. Meanwhile, nanomaterial-based barcodes are hard to reverse-engineer or imitate without advanced knowledge and technical expertise. This review describes how nanomaterials can be used as barcodes, discusses advantages and limitations of each type of nanomaterial-based barcode, and points out ways that could help design and prepare better nanomaterial-based barcodes.

Covert thermal barcodes based on phase change nanoparticles.

An unmet need is to develop covert barcodes that can be used to track-trace objects, and authenticate documents. This paper describes a new nanoparticle-based covert barcode system, in which a selected panel of solid-to-liquid phase change nanoparticles with discrete and sharp melting peaks is added in a variety of objects such as explosive derivative, drug, polymer, and ink. This method has high labeling capacity owing to the small sizes of nanoparticles, sharp melting peaks, and large scan range of thermal analysis. The thermal barcode can enhance forensic investigation by its technical readiness, structural covertness, and robustness.

Printed multilayer microtaggants with phase change nanoparticles for enhanced labeling security.

There is an urgent need to develop taggants that can be used to identify objects, prevent fraud, and deter counterfeiting with high reliability, high capacity, and minimal effort. This paper describes a new multilayer covert taggant based on phase change nanoparticles (metals and eutectic alloys). A panel of selected nanoparticles with different melting temperatures have been added in matrix materials together with fluorescent dye and printed on substrates to form micro-/macrofeatures that contain thermal, fluorescence signature, and structural components. The multilayer taggants can greatly enhance security level for many commercial and forensic applications by their extremely large labeling capacity, coding readiness, and covertness.

Highly ordered MnO2 nanopillars for enhanced supercapacitor performance.

This report demonstrates a simple, but efficient method to print highly ordered nanopillars without the use of sacrificial templates or any expensive equipment. The printed polymer structure is used as a scaffold to deposit electrode material (manganese dioxide) for making supercapacitors. The simplicity of the fabrication method together with superior power density and energy density make this supercapacitor electrode very attractive for the next-generation energy storage systems.

Printed sub-100 nm polymer-derived ceramic structures.

We proposed an unconventional fabrication technique called spin-on nanoprinting (SNAP) to generate and transfer sub-100 nm preceramic polymer patterns onto flexible and rigid substrates. The dimensions of printed nanostructures are almost the same as those of the mold, since the ceramic precursor used is a liquid. The printed patterns can be used as a replica for printing second-generation structures using other polymeric materials or they can be further converted to desirable ceramic structures, which are very attractive for high-temperature and harsh environment applications. SNAP is an inexpensive parallel process and requires no special equipment for operation.