Nano-TiO Drives Epithelial-Mesenchymal Transition in Intestinal Epithelial Cancer Cells.

The majority of cancer mortality is associated with cancer metastasis. Epithelial-to-mesenchymal transition (EMT) is a process by which cells attain migratory and invasive properties, eventually leading to cancer metastasis. Here, it is shown that titanium dioxide nanoparticles (nano-TiO ), a common food additive, can induce the EMT process in colorectal cancer cells.

Mycobacterium tuberculosis toxin Rv2872 is an RNase involved in vancomycin stress response and biofilm development.

Bacterial toxin-antitoxin (TA) systems are emerging important regulators of multiple cellular physiological events and candidates for novel antibiotic targets. To explore the role of Mycobacterium tuberculosis function, unknown toxin gene Rv2872 was heterologously expressed in Mycobacterium smegmatis (MS_Rv2872). Upon induction, MS_Rv2872 phenotype differed significantly from the control, such as increased vancomycin resistance, retarded growth, cell wall, and biofilm structure.

[Molecular mechanisms underlying daptomycin resistance].

Due to potent bactericidal activity and low rate of drug-resistance, daptomycin is recognized as first line antibiotic to treat serious infections caused by drug-resistant Gram-positive pathogens. However, the incidence of daptomycin resistance is increasing due to its widespread application. Alteration of cell wall homeostasis and membrane phospholipid metabolism is involved in daptomycin resistance.

Evolution of thiolate-stabilized Ag nanoclusters from Ag-thiolate cluster intermediates.

The synthesis of atomically precise thiolate-stabilized silver (Ag) nanoclusters is the subject of intense research interest, yet the formation mechanism of such nanoclusters remains obscure. Here, electrospray ionization mass spectrometry is successfully applied to monitor the reaction intermediates formed during the sodium-borohydride-reduction of silver 4-tert-butylbenzenethiolate (AgSPh-tBu). We demonstrate a unique evolution route to thiolate-stabilized Ag nanoclusters mediated by Ag-thiolate clusters.

Toward Total Synthesis of Thiolate-Protected Metal Nanoclusters.

Total synthesis, where desired organic- and/or biomolecules could be produced from simple precursors at atomic precision and with known step-by-step reactions, has prompted centuries-lasting bloom of organic chemistry since its conceptualization in 1828 (Wöhler synthesis of urea). Such expressive science is also highly desirable in nanoscience, since it represents a decisive step toward atom-by-atom customization of nanomaterials for basic and applied research. Although total synthesis chemistry is less established in nanoscience, recent years have witnessed seminal advances and increasing research efforts devoted into this field.

Probing the Qi of traditional Chinese herbal medicines by the biological synthesis of nano-Au.

Herbal medicines with different Qi properties (the primary proxy of their therapeutic effects) are used in traditional Chinese medicine to maintain the harmony of vital forces in a human body. In the Western medicinal practice, the classification of Qi into four major families ("Si Qi" in Chinese Pinyin) is a challenging endeavor, especially by a simple non-reductionist approach. The method presented here is however able to distinguish the Qi of herbal medicines based on the measurements of several Qi-related features in a biological synthesis of nano-Au in herbal extracts: solution color, surface plasmon resonance properties, reaction time and nano-Au morphology.

Revealing isoelectronic size conversion dynamics of metal nanoclusters by a noncrystallization approach.

Atom-by-atom engineering of nanomaterials requires atomic-level knowledge of the size evolution mechanism of nanoparticles, which remains one of the greatest mysteries in nanochemistry. Here we reveal atomic-level dynamics of size evolution reaction of molecular-like nanoparticles, i.e.

[Mycobacterium tuberculosis PhoP system].

PhoPR is an important two-component regulatory system in Mycobacterium tuberculosis. PhoP is essential for virulence as a response regulator involved in cell wall lipid biosynthesis and regulation of gene expression. In this review, the structure, function and vaccine application of PhoP were summarized, as well as some questions that need to be solved.

Conductive 3D sponges for affordable and highly-efficient water purification.

Effective, affordable and low energy water purification technologies are highly desirable to address the current environmental issues. In this study, we developed a low-cost method to achieve efficient organic pollutants degradation by incorporating conductive nanomaterials (i.e.

Acute exposure to crotonaldehyde induces dysfunction of immune system in male Wistar rats.

Crotonaldehyde is a ubiquitous air pollutant in the environment. It is reported to be harmful to the biosystems in vivo and in vitro. The exposure to crotonaldehyde irritates the mucous membranes and induces edema, hyperemia, cell necrosis, inflammation, and acute respiratory distress syndrome in the lungs.

Sigma factors mediated signaling in Mycobacterium tuberculosis.

Activation of signaling cascades is critical for Mycobacterium tuberculosis (Mtb) to adapt the macrophage lifestyle. Parallel to several signal systems, sigma factor systems, especially the extra-cytoplasmic function sigma factors, are crucial for Mtb signaling. Most sigma factors lack a signal sensory domain and often are activated by various proteins that perceive the environmental cues and relay the signals through variegated post-translational modifications via the activity of antisigma factor, protein kinase and related transcriptional regulators.

Protein tyrosine kinase, PtkA, is required for Mycobacterium tuberculosis growth in macrophages.

Protein phosphorylation plays a key role in Mycobacterium tuberculosis (Mtb) physiology and pathogenesis. We have previously shown that a secreted protein tyrosine phosphatase, PtpA, is essential for Mtb inhibition of host macrophage acidification and maturation, and is a substrate of the protein tyrosine kinase, PtkA, encoded in the same operon. In this study, we constructed a ∆ptkA deletion mutant in Mtb and found that the mutant exhibited impaired intracellular survival in the THP-1 macrophage infection model, correlated with the strain's inability to inhibit macrophage phagosome acidification.

Unraveling the molecular mechanism of photosynthetic toxicity of highly fluorescent silver nanoclusters to Scenedesmus obliquus.

While the discovery of numerous attractive properties of silver at the nanoscale has increased their demand in many sectors including medicine, optics, sensing, painting and cosmetics, it has also raised wide public concerns about their effect on living organisms in aquatic environment. Despite the continuous effort to understand the various aspects of the toxicity of silver nanomaterials, the molecular level understanding on their cytotoxicity mechanism to biological organisms has remained unclear. Herein, we demonstrated the underlying mechanism of the photosynthetic toxicity against green algae namely, Scenedesmus obliquus by using an emerging silver nanomaterial, called silver nanoclusters (defined as r-Ag NCs).

Precise control of alloying sites of bimetallic nanoclusters via surface motif exchange reaction.

Precise control of alloying sites has long been a challenging pursuit, yet little has been achieved for the atomic-level manipulation of metallic nanomaterials. Here we describe utilization of a surface motif exchange (SME) reaction to selectively replace the surface motifs of parent [Ag(SR)] (SR = thiolate) nanoparticles (NPs), leading to bimetallic NPs with well-defined molecular formula and atomically-controlled alloying sites in protecting shell. A systematic mass (and tandem mass) spectrometry analysis suggests that the SME reaction is an atomically precise displacement of SR-Ag(I)-SR-protecting modules of Ag NPs by the incoming SR-Au(I)-SR modules, giving rise to a core-shell [Ag@Au(SR)].

Steam distillation/drop-by-drop extraction with gas chromatography-mass spectrometry for fast determination of volatile components in jujube (Ziziphus jujuba Mill.) extract.

Background: Jujube extract is commonly used as a food additive and flavoring. The unique jujube aroma and the mild sweet aroma of the extract are critical factors that determine product quality and affect consumer acceptability. The aroma changes with changes in the extraction condition, which is typically dependent on the characteristics of volatile oils in the extract.

Divergent Responses of Forest Soil Microbial Communities under Elevated CO in Different Depths of Upper Soil Layers.

Numerous studies have shown that the continuous increase of atmosphere CO concentrations may have profound effects on the forest ecosystem and its functions. However, little is known about the response of belowground soil microbial communities under elevated atmospheric CO (eCO) at different soil depth profiles in forest ecosystems. Here, we examined soil microbial communities at two soil depths (0 to 5 cm and 5 to 15 cm) after a 10-year eCO exposure using a high-throughput functional gene microarray (GeoChip).

Understanding seed-mediated growth of gold nanoclusters at molecular level.

The continuous development of total synthesis chemistry has allowed many organic and biomolecules to be produced with known synthetic history-that is, a complete set of step reactions in their synthetic routes. Here, we extend such molecular-level precise reaction routes to nanochemistry, particularly to a seed-mediated synthesis of inorganic nanoparticles. By systematically investigating the time-dependent abundance of 35 intermediate species in total, we map out relevant step reactions in a model size growth reaction from molecularly pure Au to Au nanoparticles.

Mycobacterium tuberculosis Major Facilitator Superfamily Transporters.

The cell membrane or biofilm serve as permeable barrier for xenobiotics to maintain the homeostasis of cells or bacterial community. Transport systems are essential for the uptake of nutrients and substances necessary for biofilm formation, efflux of deleterious compounds, as well as communication between cells and environment. Major facilitator superfamily (MFS) represents the largest secondary transporter family and is responsible for the transport of a broad spectrum of substrates with diverse physiochemical properties by utilizing the energy stored in electrochemical gradient across the membrane.

Complete genome sequence analysis of the novel mycobacteriophage Shandong1.

In this study, we isolated a mycobacteriophage infecting Mycobacterium smegmatis mc155 from a soil sample collected in Shandong Province in China. This phage was named Shandong1. It is a member of the family Siphoviridae with an isometric head and a long tail.

Using Mind Maps to Improve Medical Student Performance in a Pharmacology Course at Kunming Medical University.

Objective: To determine whether students using mind maps would improve their performance in a final examination at the end of lecture-based pharmacology course.

Study Design: Aquasi-experimental study.

Place And Duration Of Study: Kunming Medical University, from September 2014 to January 2015.

Effect of ligand structure on the size control of mono- and bi-thiolate-protected silver nanoclusters.

Ligand structure could control the size and structure of thiolate-protected silver nanoclusters (Ag NCs) in water. Small alkane-thiols, medium-sized aromatic-thiols, and bulky thiol-containing tri-peptides direct the formation of Ag(SR), Ag(SR), and Ag(SR), respectively. In addition, small alkane-thiol collocates well with other types of thiolate ligand to generate bi-thiolate-protected Ag NCs with controlled ligand landscapes on their surfaces.

Mycobacterium tuberculosis PPE44 (Rv2770c) is involved in response to multiple stresses and promotes the macrophage expression of IL-12 p40 and IL-6 via the p38, ERK, and NF-κB signaling axis.

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a formidable threat to global public health. The successful intracellular persistence of M. tuberculosis significantly contributes to the intractability of tuberculosis.

Evaluation of whole cigarette smoke induced oxidative stress in A549 and BEAS-2B cells.

Cigarette smoke is a complex and oxidative aerosol. Previous researches on the hazards of cigarette smoke mainly focused on the adverse bioeffects induced by its condensates or gas vapor phase, which ignored the dynamic processes of smoking and the cigarette smoke aging. To overcome these disadvantages, we performed air-liquid interface exposure of whole smoke, which used native and unmodified smoke and ensured the exposure similar to physiological inhalation.

Immunomodulatory effects of cigarette smoke condensate in mouse macrophage cell line.

Increasing evidence has demonstrated that the secretion of cytokines may be associated with cigarette smoke-induced immunomodulatory effects, but a comprehensive analysis of the cytokine profile for cigarette smoke condensate (CSC) exposure is lacking. The aims of this study were to (1) examine the release of 20 cytokines induced by CSC from 12 brands of cigarettes in macrophages cells (Ana-1) and (2) to investigate the general characteristics of the immunomodulatory effects of CSC. Luminex technology was used to simultaneously determine the levels of 20 cytokines (interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, IL-17, granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-γ (IFN-γ), keratinocyte-derived Chemokine (KC), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 1α (MIP-1α), induced protein 10 (IP-10), tumor necrosis factor α (TNF-α), vascular endothelial growth factor (VEGF), monkine inducible by γ interferon (MIG), and fibroblast growth factor (FGF)-basic) in the supernatants from Ana-1 cells treated with the CSC.