Optical microangiography (OMAG) is a powerful optical angiographic tool to visualize micro-vascular flow in vivo. Despite numerous demonstrations for the past several years of the qualitative relationship between OMAG and flow, no convincing quantitative relationship has been proven. In this paper, we attempt to quantitatively correlate the OMAG signal with flow. Specifically, we develop a simplified analytical model of the complex OMAG, suggesting that the OMAG signal is a product of the number of particles in an imaging voxel and the decorrelation of OCT (optical coherence tomography) signal, determined by flow velocity, interframe time interval, and wavelength of the light source. Numerical simulation with the proposed model reveals that if the OCT amplitudes are correlated, the OMAG signal is related to a total number of particles across the imaging voxel cross-section per unit time (flux); otherwise it would be saturated but its strength is proportional to the number of particles in the imaging voxel (concentration). The relationship is validated using microfluidic flow phantoms with various preset flow metrics. This work suggests OMAG is a promising quantitative tool for the assessment of vascular flow. Chen, and R. K. Wang, "Repeatability and reproducibility of optic nerve head perfusion measurements using optical coherence tomography angiography," J. Biomed. Opt. 21(6), 065002 (2016). 42. Z. Chu, J. Lin, C. Gao, C. Xin, Q. Zhang, C. L. Chen, L. Roisman, G. Gregori, P. J. Rosenfeld, and R. K. Wang, "Quantitative assessment of the retinal microvasculature using optical coherence tomography angiography," J.

An increase in mechanical load in the heart causes cardiac hypertrophy, either physiologically (heart development, exercise and pregnancy) or pathologically (high blood pressure and heart-valve regurgitation). Understanding cardiac hypertrophy is critical to comprehending the mechanisms of heart development and treatment of heart disease. However, the major molecular event that occurs during physiological or pathological hypertrophy is the dynamic process of sarcomeric addition, and it has not been observed. In this study, a custom-built second harmonic generation (SHG) confocal microscope was used to study dynamic sarcomeric addition in single neonatal CMs in a 3D culture system under acute, uniaxial, static, sustained stretch. Here we report, for the first time, live-cell observations of various modes of dynamic sarcomeric addition (and how these real-time images compare to static images from hypertrophic hearts reported in the literature): 1) Insertion in the mid-region or addition at the end of a myofibril; 2) Sequential addition with an existing myofibril as a template; and 3) Longitudinal splitting of an existing myofibril. The 3D cell culture system developed on a deformable substrate affixed to a stretcher and the SHG live-cell imaging technique are unique tools for real-time analysis of cultured models of hypertrophy.

The catalyst layer (CL) in a proton exchange membrane fuel cell is a critical component that determines the performance of the cell. Although the CL is fabricated using a catalyst ink, there have been no studies concerning the effect of the quality of the ink on the CL structure. In the present work, catalyst ink samples were analyzed using gas chromatography-mass spectrometry. The results indicate the formation of hydrophobic compounds from the alcohol in the solvent, due to catalysis by Pt. These products result in the agglomeration of Pt/C particles, thus initiating cracks in the CL during the drying process.

Previous studies showed that the expression of an mRNA corresponding to VDUP-1 was decreased within MNU-induced rat mammary tumors. RNA from mammary tissue was DNase treated and reverse transcribed and the resulting cDNA was amplified using primers designed to amplify VDUP-1 (382 bp fragment) and glyceraldehyde-6-phosphate dehydrogenase (GAPDH) (416 bp fragment). Analysis of mammary cDNA derived from untreated or MNU-treated rats indicated that VDUP-1 expression within tumor tissue was significantly decreased, a finding which agrees with previous Northern blotting experiments. The differential expression was confirmed in tissue sections using an antisense VDUP-1 riboprobe for in situ hybridization studies which demonstrated that VDUP-1 staining in all cell types within tumor tissue was greatly decreased. VDUP-1 mRNA was expressed to a greater extent within epithelial cells and to a much lesser extent within stromal cells, including endothelial cells, in untreated mammary tissue. A significant decrease in VDUP-1 expression was detected as early as six weeks after MNU treatment, before tumors had formed. Bilateral ovariectomy did not alter VDUP-1 expression in untreated mammary tissue and ovariectomy prior to MNU treatment prevented tumor formation, as well as the associated decrease in VDUP-1 expression. The relative expression of VDUP-1 was higher in lung tissue than in adrenal, heart, kidney, liver, mammary, muscle, and ovary. Treatment of a cell line derived from an MNU-induced rat mammary tumor (MNU cells) with 1,25-dihydroxyvitamin D3 resulted in a significant increase in VDUP-1 expression and also inhibited cell growth in the absence of serum. The data are consistent with a role for VDUP-1 in mediating the inhibitory effects of 1,25-dihydroxyvitamin D3 on tumor cell growth.

Scope Studies based on DHA/EPA supplementation in animal models of inflammatory bowel disease (IBD) reveal controversial results. It is speculated that different forms of DHA may explain the controversial results. Therefore, the effects of DHA‐enriched phospholipids (DHA‐PL) and DHA‐enriched triglyceride (DHA‐TG) on IBD are compared. Methods and results Male C57BL6/J mice are given DHA‐PL and DHA‐TG for 14 consecutive days, and receive ad libitum a 3.0% dextran sodium sulfate solution on the eighth day to establish IBD model. The results show that both DHA‐PL and DHA‐TG can reverse the colitis pathological process by decreasing the disease activity indexes (DAI), raising the colon length, suppressing the intestinal permeability, suppressing the oxidative stress, down‐regulating pro‐inflammatory factors, up‐regulating anti‐inflammatory factor in colon tissues. DHA‐PL and DHA‐TG also regulate the composition of gut microbiota via decreasing of the abundance Bacteroidetes and Firmicutes, and DHA‐TG increases the abundance of Odoribacter. Importantly, DHA‐PL and DHA‐TG obviously attenuate the activation of microglia. Conclusions DHA‐PL shows outstanding advantages in regulating oxidative stress, inflammatory responses, and intestinal barrier permeability. The current research indicates that the existence of DHA affects the improvement, DHA in phospholipid form could be a more effective choice for nutritional intervention to prevent and treat colitis.