Diisopropylfluorophosphate (DFP) volatizes and cross-contaminates wells in a common 96-well plate zebrafish larvae exposure method

Diisopropylfluorophosphate (DFP) is an organophosphate (OP) that is commonly used to study the neurotoxic effects of acutely intoxicating OP exposure. In preliminary studies, we discovered abnormal deaths in DMSO-only exposed larvae housed in the same plate as DFP-exposed larvae, and hypothesized that DFP volatilizes and cross-contaminates wells when using a 96-well plate exposure method for exposing zebrafish larvae. Survivability and acetylcholinesterase activity assays confirmed DFP presence in the tissues of zebrafish ostensibly exposed to DMSO only. These findings indicate DFP cross-contamination, which raises concerns for the experimental design of studies evaluating the toxicity of volatile and semi-volatile substances.

An Automatic Exposure Method of Plane Array Remote Sensing Image Based on Two-Dimensional Entropy

The improper setting of exposure time for the space camera will cause serious image quality degradation (overexposure or underexposure) in the imaging process. In order to solve the problem of insufficient utilization of the camera’s dynamic range to obtain high-quality original images, an automatic exposure method for plane array remote sensing images based on two-dimensional entropy is proposed. First, a two-dimensional entropy-based image exposure quality evaluation model is proposed. The two-dimensional entropy matrix of the image is partitioned to distinguish the saturated areas (region of overexposure and underexposure) and the unsaturated areas (region of propitious exposure) from the original image. The ratio of the saturated area is used as an evaluating indicator of image exposure quality, which is more sensitive to the brightness, edges, information volume, and signal-to-noise ratio of the image. Then, the cubic spline interpolation method is applied to fit the exposure quality curve to efficiently improve the camera’s exposure accuracy. A series of experiments have been carried out for different targets in different environments using the existing imaging system to verify the superiority and robustness of the proposed method. Compared with the conventional automatic exposure method, the signal-to-noise ratio of the image obtained by the proposed algorithm is increased by at least 1.6730 dB, and the number of saturated pixels is reduced to at least 2.568%. The method is significant to improve the on-orbit autonomous operating capability and on-orbit application efficiency of space camera.

Dynamic evolution of emphysema and airway remodeling in two mouse models of COPD

Background Establishment of a mouse model is important for investigating the mechanism of chronic obstructive pulmonary disease (COPD). In this study, we observed and compared the evolution of the pathology in two mouse models of COPD induced by cigarette smoke (CS) exposure alone or in combination with lipopolysaccharide (LPS). Methods One hundred eight wild-type C57BL/6 mice were equally divided into three groups: the (1) control group, (2) CS-exposed group (CS group), and (3) CS + LPS-exposed group (CS + LPS group). The body weight of the mice was recorded, and noninvasive lung function tests were performed monthly. Inflammation was evaluated by counting the number of inflammatory cells in bronchoalveolar lavage fluid and measuring the expression of the IL-6 mRNA in mouse lung tissue. Changes in pathology were assessed by performing hematoxylin and eosin and Masson staining of lung tissue sections. Results The two treatments induced emphysema and airway remodeling and decreased lung function. Emphysema was induced after 1 month of exposure to CS or CS + LPS, while airway remodeling was induced after 2 months of exposure to CS + LPS and 3 months of exposure to CS. Moreover, the mice in the CS + LPS group exhibited more severe inflammation and airway remodeling than the mice in the CS group, but the two treatments induced similar levels of emphysema. Conclusion Compared with the single CS exposure method, the CS + LPS exposure method is a more suitable model of COPD in airway remodeling research. Conversely, the CS exposure method is a more suitable model of COPD for emphysema research due to its simple operation.

The impact of K-beauty social media influencers, sponsorship, and product exposure on consumer acceptance of new products

This research identified the different ways in which K-beauty social media influencers (SMIs) impact consumers’ tendencies to accept new products by closely investigating their sponsorship displays and product exposure methods. We conducted an experiment to examine how influencers’ posts affect Chinese millennial consumers’ acceptance of new products. We used a 2 (influencer type: celebrity versus general public) × 2 (sponsorship display status: display versus no display) × 2 (product exposure method: exposure versus no exposure) factorial design. The findings reveal that the social media posts that made consumers most likely to accept a new product were created by a general public influencer and did not include a display of any sponsorship affiliation with the product. Additionally, there was a significant interplay between the influencer type, sponsorship display status, and product exposure method regarding consumers’ acceptance intention toward a new product. A consumer was most likely to accept and purchase a new product when three factors (general public influencer, sponsorship displayed, and product exposed) were combined. Based on the findings, we draw important implications and present marketing strategies for companies in the beauty industry that use SMI marketing.

Induction of Artesunate Resistance in Plasmodium Falciparum 3D7 Strain Using Intermittent Exposure Method and Comparing P.fk13 Sequence between Susceptible and Resistant Strains

Background: Malaria is a major health issues in a number of countries in the world, especially tropical countries. Over the past 50 years, the resistance of Plasmodium falciparum has expanded against the antimalarial drugs that had been used to treat the disease. Recently resistance to some derivatives of artemisinin and the failure of artemisinin combination therapy (ACT) has threatened all major achievements in malaria control. Resistant strains are limited around the world, but it may spread very soon, hence the necessary to be prepared for any event regarding this matter, it is needed to organize more investigations about resistant strains and related genes. Preparation of a new resistant strain in the laboratory can provide opportunity to predict genes responsible for resistance. The aim of this study was to induce resistance to artesunate in Plasmodium falciparum 3D7 strain using intermittent exposure method and comparing P.fk13 gene sequence between susceptible and resistance strains.Methods: Plasmodium falciparum 3D7 strain was cultured according to Trager & Jensen method with some modifications. Serial concentrations between 10-2 mol/l, to 10-7mol/l were prepared, then P.falciparum 3D7 was exposed to each of the dilution to determine IC50 and lethal dose. After 24 hours exposure the rate of parasitemia and mean of growth inhibitory percent were evaluated. Sensitivity reduction process was started from the concentration of 10-7mol/l and ended at 10-2mol/l. Exposed parasites were collected after at least 27 days after cultivation in each drug concentration. DNA extraction, PCR and sequencing process were performed to investigate any possible mutations in the pfk13 gene sequence.Results: Effectiveness of 10-2mol/l concentration of artemisinin was found as a lethal dose. The resistant strain was provided in the lab, sequenced and registered in the gene bank as P.f Art -2, (accession number MH796123. 1). Alignment of this registered sample showed no mutation in P.f kelch13 gene in comparison with standard strain submitted in the Genebank. Conclusions: Results of this study showed that resistance to artesunate in malaria parasite may occur but with no mutation in the P.f kelch13 gene. Therefore, whole genome sequencing should be applied to determine mutations in resistant strains.