Radial mechanical properties of deoxyribonucleic acid molecules.

Given the small diameter of deoxyribonucleic acid (DNA), the difficulty in studying its radial mechanical properties laid in the challenge of applying a precise and controlled small force. In this work, the radial mechanical properties of DNA were measured in the AFM. DNA adhesion properties were analyzed through force-distance curves and adhesion images.

Synergistic Regulation of DNA Morphology by Metal Cations and Low pH.

As a flexible biomolecule, the spatial structure of DNA is variable. The effects of concentration, metal cations, and low pH on DNA morphology were studied. For the high concentration of DNA, the cross-linked branch-like or network structures were formed.

pH-induced changes in IgE molecules measured by atomic force microscopy.

The environment surrounding proteins is tightly linked to its dynamics, which can significantly influence the conformation of proteins. This study focused on the effect of pH conditions on the ultrastructure of Immunoglobulin E (IgE) molecules. Herein, the morphology, height, and area of IgE molecules incubated at different pH were imaged by atomic force microscopy (AFM), and the law of IgE changes induced by pH value was explored.

Two mutations on S2 subunit were critical for Vero cell tropism expansion of infectious bronchitis virus HV80.

Infectious bronchitis virus (IBV) restricts cell tropism. Except for the Beaudette strain, other IBVs cannot infect mammalian cell lines. The limited cell tropism of other IBVs has hindered IBV vaccine development and research on the mechanisms of IBV infection.

Effect of resveratrol on SH-SY5Y cells studied by atomic force microscopy.

In this paper, the effects of resveratrol on the viability, morphology, biomechanics and bioelectricity of SH-SY5Y cells were studied by atomic force microscopy. MTT assay showed that resveratrol had a dose effect on SH-SY5Y cells, and its activity was related to drug concentration and drug action time. With the increase of resveratrol concentration or the extension of action time, the activity of SH-SY5Y cells decreased obviously.

Cell recognition based on atomic force microscopy and modified residual neural network.

Cell recognition methods are in high demand in cell biology and medicine, and the method based on atomic force microscopy (AFM) shows a great value in application. The difference in mechanical properties or morphology of cells has been frequently used to detect whether cells are cancerous, but this detection method cannot be a general means for cancer cell detection, and the traditional artificial feature extraction method also has its limitations. In this work, we proposed an analytic method based on the physical properties of cells and deep learning method for recognizing cell types.

Large-scale fabrication of an ultrathin broadband absorber using quasi-random dielectric Mie resonators.

Ultrathin broadband absorber maintaining a near-uniform low reflectivity over a broadband wavelength is essential for many optical applications, such as light harvesting and nanoscale imaging. Recently, there has been considerable interest in employing arrays of high-index dielectric Mie resonators on surfaces to trap light and reduce the reflectivity. For such Mie-resonant metasurfaces, however, antireflection properties featuring both a flat low reflectance curve and a wide bandwidth are hard to be satisfied simultaneously, and an efficient large-scale nanofabrication technique rarely exists.

Review on the applications of atomic force microscopy imaging in proteins.

Protein is an important component of human tissues and cells, which is closely related to various life activities. Therefore, studying the conformation of proteins can not only provide better analytic insight into its interactions with biomacromolecules, but also contribute to the biological and medical research. In recent years, the atomic force microscopy with excellent capacity shines brilliantly in obtaining information of biological samples, especially in the research of proteins.

Electrical characterization of tumor-derived exosomes by conductive atomic force microscopy.

The physical properties of tumor-derived exosomes have gained much attention because they are helpful to better understand the exosomes in biomedicine. In this study, the conductive atomic force microscopy (C-AFM) was employed to perform the electrical characterizations of exosomes, and it obtained the topography and current images of samples simultaneously. The exosomes were absorbed onto the mica substrates coated with a gold film of 20 nm thick for obtaining the current images of samples by C-AFM in air.

Electrical conductivity measurement ofDNA molecules by conductive atomic force microscopy.

Conductive atomic force microscopy (C-AFM) is a powerful tool used in the microelectronics analysis by applying a certain bias voltage between the conducting probe and the sample and obtaining the electrical information of sample. In this work, the surface morphological information and current images of the lambda DNA (DNA) molecules with different distributions were obtained by C-AFM. The 1 and 10 nglDNA solutions were dripped onto mica sheets for making randomly distributed DNA and DNA network samples, and another 1 nglDNA sample was placed in a DC electric field with a voltage of 2 V before being dried for stretching the DNA sample.

Self-Assembly of DNA molecules in magnetic Fields.

In this work, a rich variety of self-assembled DNA patterns were obtained in the magnetic field. Herein, atomic force microscopy (AFM) was utilized to investigate the effects of the concentration of DNA solution, intensity and direction of magnetic field and modification of mica surface by different cations on the self-assembly of DNA molecules. It was found that owning to the change of the DNA concentration, even under the same magnetic field, the DNA self-assembly results were different.

The V617I Substitution in Avian Coronavirus IBV Spike Protein Plays a Crucial Role in Adaptation to Primary Chicken Kidney Cells.

The naturally isolated avian coronavirus infectious bronchitis virus (IBV) generally cannot replicate in chicken kidney (CK) cells. To explore the molecular mechanism of IBV adapting to CK cells, a series of recombinant viruses were constructed by chimerizing the S genes of CK cell-adapted strain H120 and non-adapted strain IBYZ. The results showed that the S2 subunit determines the difference in cell tropism of the two strains.

Direct imaging of antigen-antibody binding by atomic force microscopy.

Direct observation of antigen-antibody binding at the nanoscale has always been a considerable challenging problem, and researchers have made tremendous efforts on it. In this study, the morphology of biotinylated antibody-specific Immunoglobulin E (IgE) immune complexes has been successfully imaged by atomic force microscopy (AFM) in the tapping-mode. The AFM images indicated that the individual immune complex was composed of an IgE and a biotinylated antibody.

Recombinant infectious bronchitis coronavirus H120 with the spike protein S1 gene of the nephropathogenic IBYZ strain remains attenuated but induces protective immunity.

Infectious bronchitis (IB) is a highly infectious viral disease responsible for major economic losses in the poultry industry. A reverse genetic vaccine is a safe, rapid, and effective method of achieving IB prevention and control. In this study, we constructed the recombinant strain, rH120-S1/YZ, using a reverse genetic system, based on the backbone of the H120 vaccine strain, with the S1 gene replaced with that of the QX-like nephropathogenic strain, ck/CH/IBYZ/2011, isolated in China.

Anti-degranulation response of herbal formula in RBL-2H3 cells.

Allergic diseases not only bring serious economic burden to the patients, but also consume a lot of substantial resources of social medical systems. Thus, the prevention and treatment of allergic diseases are imperative. In this study, the anti-degranulation activity of herbal formula was evaluated using the rat basophil leukemia cells (RBL-2H3) as in vitro model.

Pathogenicity of a QX-like strain of infectious bronchitis virus and effects of accessory proteins 3a and 3b in chickens.

QX-like genotype infectious bronchitis virus (IBV) has become prevalent in recent years. Few studies have reported the effects of accessory proteins 3a and 3b on pathogenicity in vivo. We developed a reverse genetics system to manipulate the genome of a QX-like IBV strain IBYZ.

Controlled Self-Assembly of λ-DNA Networks with the Synergistic Effect of a DC Electric Field.

Large-scale and morphologically controlled self-assembled λ-DNA networks were successfully constructed by the synergistic effect of a DC electric field. The effect of DNA concentration, direction, and intensity of the electric field, even the modification of the mica surface using Mg on the characteristics of the as-prepared DNA networks, were investigated in detail by atomic force microscopy (AFM). It was found that the horizontal electric field was more advantageous to the formation of DNA networks with more regular structures.

Imaging the Substructures of Individual IgE Antibodies with Atomic Force Microscopy.

The interactions between antibodies and substrates directly affect their conformations and thus their immune functions. Therefore, it is desirable to study the structures of antibodies at the single molecule level. Herein, the substructures of Immunoglobulin E (IgE) on solid surfaces were investigated.

Effect of extract from ginseng rust rot on the inhibition of human hepatocellular carcinoma cells in vitro.

Hepatocellular carcinoma (HCC) is one of major leading causes of cancer death worldwide. As a traditional medicine, the anti-cancer function of ginseng is being growingly recognized and investigated. However, the effect of ginseng rust rot on human HCC is unknown yet.

Attention-Based Multi-NMF Deep Neural Network with Multimodality Data for Breast Cancer Prognosis Model.

Today, it has become a hot issue in cancer research to make precise prognostic prediction for breast cancer patients, which can not only effectively avoid overtreatment and medical resources waste, but also provide scientific basis to help medical staff and patients family members to make right medical decisions. As well known, cancer is a partly inherited disease with various important biological markers, especially the gene expression profile data and clinical data. Therefore, the accuracy of prediction model can be improved by integrating gene expression profile data and clinical data.

Reduced graphene oxide-mediated synthesis of MnO nanomaterials for an asymmetric supercapacitor cell.

Herein, MnO/reduced graphene oxide composites are prepared a facile solution-phase method for supercapacitor application. Transmission electron microscopy results reveal the uniform distribution of MnO nanoparticles on graphene layers. The morphology of the MnO nanomaterial is changed by introducing the reduced graphene oxide during the preparation process.

Highly Active PdNi/RGO/Polyoxometalate Nanocomposite Electrocatalyst for Alcohol Oxidation.

A PdNi/RGO/polyoxometalate nanocomposite has been successfully synthesized by a simple wet-chemical method. Characterizations such as transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and X-ray photoelectron spectroscopy are employed to verify the morphology, structure, and elemental composition of the as-prepared nanocomposite. Inspired by the fast-developing fuel cells, the electrochemical catalytic performance of the nanocomposite toward methanol and ethanol oxidation in alkaline media is further tested.

Novel α, β-Unsaturated Sophoridinic Derivatives: Design, Synthesis, Molecular Docking and Anti-Cancer Activities.

Using sophoridine and chalcone as the lead compounds, a series of novel α, β-unsaturated sophoridinic derivatives were designed, synthesized, and evaluated for their in vitro cytotoxicity. Structure-activity relationship (SAR) analysis indicated that introduction of α, β-unsaturated ketone moiety and heterocyclic group might significantly enhance anticancer activity. Among the compounds, and exhibited potential effects against HepG-2 and CNE-2 human cancer cell lines.

The change in sex hormone binding globulin and the influence by gestational diabetes mellitus in fetal period.

Objective: To investigate the influence of gestational diabetes mellitus (GDM) on the change of SHBG in fetus.

Method: Forty-eight pregnant women with GDM and 86 women with normal pregnancy were included in the study. The following were measured in the serums of pregnant women, amniotic fluids, and umbilical cord serums: glucose, insulin, peptide-C, SHBG, and sex hormones.