228 research outputs found
Persistence of Respirator Use Learning
<div><p>Although retraining and repeat fit-testing are needed for respirator users, the optimal frequency is uncertain. The persistence of proper respirator donning/doffing techniques and changes in quantitative fit factor over 6 months after initial training were measured in this study. Initial training was designed for rapid rollout situations in which direct contact with well-trained occupational health professionals may be infeasible. Subjects (n = 175) were assigned randomly to use either a filtering facepiece N95 (FFR) or dual cartridge half facemask (HFM) respirator. Each was assigned randomly to one of three training methods—printed brochure, video, or computer-based training. Soon after initial training, quantitative fit and measures of proper technique were determined. These measurements were repeated 6 months later. In the six-month followup, subjects were randomized to receive either a brief reminder card or a placebo card. Total performance score, major errors, and quantitative fit all became significantly worse at 6 months. An individual's result soon after training was the most important predictor of performance 6 months later. There was a marginal not statistically significant tendency for those initially trained by video to have better protection 6 months later. The study suggests that persons who use respirators intermittently should be thoroughly retrained and reevaluated periodically.</p><p>[Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: Additional statistical analyses.</p></div
A Unique Synthesis of 5,8-Difluoro‑2<i>H</i>‑chromene Using Silicone Oil as a Solvent
A significantly
improved synthesis of 5,8-difluoro-2<i>H</i>-chromene <b>1</b> using silicone oil as the reaction solvent
is described. The new method eliminated the tedious workup and large
quantity of waste produced via conventional methods. To our best knowledge,
this is the first report of conducting an organic reaction using silicone
oil as an organic solvent
Decreased miR-204 in H. pylori-Associated Gastric Cancer Promotes Cancer Cell Proliferation and Invasion by Targeting SOX4
<div><p>Background</p><p>The molecular mechanism between Helicobacter pylori (H. pylori) infection and gastric cancer remained largely unknown. In this study, we determined the role of miRNA in H. pylori induced gastric cancer.</p><p>Methods and Results</p><p>We found that miR-204 was decreased in H. pylori positive tissues by qRT-PCR. Knockdown of miR-204 enhanced the invasion and proliferation ability of gastric cancer cells in vitro. Luciferase assay revealed that SOX4 was target gene of miR-204, which was found up-regulated in H. pylori positive tissues. Down-regulation of miR-204 and over-expression of SOX4 promoted epithelial-mesenchymal transition process.</p><p>Conclusion</p><p>Taken together, our findings demonstrated that miR-204 may act as a tumor suppressor in H. pylori induced gastric cancer by targeting SOX4.</p></div
MiR-204 is down-regulated in H. Pylori positive patients.
<p>(A) The expression levels of miR-204 in human H. Pylori positive tissues and normal tissues relative to U6 were determined by qRT-PCR. (B) The expression levels of miR-204 in H. pylori positive and negative tumor tissues. (C) The expression levels of miR-204 in CG,CAG and dysplasia in H. pylori positive tissues and H. pylori negative tissue. (D) The expression levels of miR-204 in H. pylori infected cells. (*p<0.05).</p
Effects of miR-204 expression on cell proliferation.
<p>(A) Cells transfected with miR-204 inhibitor and viabilities were determined with CCK-8 assay. (B) Cells transfected with miR-204 mimics and viabilities were determined with CCK-8 assay. (C) Effects of miR-204 mimics or inhibitor on cell cycle of gastric cancer cells by flow cytometry. (D) Colony assay after cells transfected with miR-204 mimics and inhibitor. (*p<0.05).</p
First-Principles Study of Molecular Adsorption on Lead Iodide Perovskite Surface: A Case Study of Halogen Bond Passivation for Solar Cell Application
Organic
molecules have recently been used to modify the surface/interface
structures of lead halide perovskite solar cells to enhance device
performance. Yet, the detailed interfacial structures and adsorption
mechanism of the molecular modified perovskite surface remain elusive.
This study presents a nanoscopic structural view on how organic molecules
interact with the perovskite surface. We focus on the halogen bond
passivated lead iodide perovskite surface, based on first-principles
calculations. Our calculations show that organic molecules can interact
with the perovskite surface via halogen bonds, which modifies the
interfacial structures of the perovskite surface. We also constructed
a detailed potential energy surface of the perovskite surface by moving
the adsorbed molecule along different axes of the unit cell in order
to comprehensively understand perovskite surface structures. This
study demonstrates the effectiveness of modifying the perovskite surface
structure via a molecular adsorption approach, and anticipates that
the properties of perovskite materials can be further improved by
a molecular engineering method
Expression level of SOX4 in Helicobacter pylori positive tissues.
<p>CG: chronic gastritis; CAG: chronic atrophic gastritis;</p><p>*indicates P<0.05;</p
Effects of miR-204 on SOX4 expression by luciferase reporter assay.
<p>The potential miR-204 binding site at the 3′-UTR of SOX4 mRNA was computationally predicted by Targetscan. Cells were co-transfected with miR-204 mimics (or negative control) with pGL3-SOX4 (or pGL3-SOX4-mut) vector. Luciferase activity was normalized by the ratio of firefly and Renilla luciferase signals. * indicates P<0.05.</p
Systematically Studying Kinase Inhibitor Induced Signaling Network Signatures by Integrating Both Therapeutic and Side Effects
<div><p>Substantial effort in recent years has been devoted to analyzing data based large-scale biological networks, which provide valuable insight into the topologies of complex biological networks but are rarely context specific and cannot be used to predict the responses of cell signaling proteins to specific ligands or compounds. In this work, we proposed a novel strategy to investigate kinase inhibitor induced pathway signatures by integrating multiplex data in Library of Integrated Network-based Cellular Signatures (LINCS), e.g. KINOMEscan data and cell proliferation/mitosis imaging data. Using this strategy, we first established a PC9 cell line specific pathway model to investigate the pathway signatures in PC9 cell line when perturbed by a small molecule kinase inhibitor GW843682. This specific pathway revealed the role of PI3K/AKT in modulating the cell proliferation process and the absence of two anti-proliferation links, which indicated a potential mechanism of abnormal expansion in PC9 cell number. Incorporating the pathway model for side effects on primary human hepatocytes, it was used to screen 27 kinase inhibitors in LINCS database and PF02341066, known as Crizotinib, was finally suggested with an optimal concentration 4.6 uM to suppress PC9 cancer cell expansion while avoiding severe damage to primary human hepatocytes. Drug combination analysis revealed that the synergistic effect region can be predicted straightforwardly based on a threshold which is an inherent property of each kinase inhibitor. Furthermore, this integration strategy can be easily extended to other specific cell lines to be a powerful tool for drug screen before clinical trials.</p></div
Six kinase inhibitors with highest effect index for PC9 cell line.
<p>Six kinase inhibitors with highest effect index for PC9 cell line.</p
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