Search

Necroptosis, a recently discovered form of cell-programmed death that is distinct from apoptosis, has been confirmed to play a significant role in the pathogenesis of bacterial infections in various animal models. Necroptosis is advantageous to the host, but in some cases, it can be detrimental. To understand the impact of necroptosis on the pathogenesis of bacterial infections, we described the roles and molecular mechanisms of necroptosis caused by different bacterial infections in this review.

Optically derived tissue properties across a range of breast densities and the effects of breast compression on estimates of hemoglobin, oxygen metabolism, and water and lipid concentrations were obtained from a coregistered imaging system that integrates near-infrared spectral tomography (NIRST) with digital breast tomosynthesis (DBT). Image data were analyzed from 27 women who underwent four IRB approved NIRST/DBT exams that included fully and mildly compressed breast acquisitions in two projections—craniocaudal (CC) and mediolateral-oblique (MLO)—and generated four data sets per patient (full and moderate compression in CC and MLO views). Breast density was correlated with HbT (r = 0.64, p = 0.001), water (r = 0.62, p = 0.003), and lipid concentrations (r = −0.74, p < 0.001), but not oxygen saturation. CC and MLO views were correlated for individual subjects and demonstrated no statistically significant differences in grouped analysis. Comparison of compressed and uncompressed imaging demonstrated a significant decrease in oxygen saturation under compression (58% versus 50%, p = 0.04). Mammographic breast density categorization was correlated with measured optically derived properties. [ABSTRACT FROM AUTHOR]

Five coordination complexes based on the flexible ligand 1,4-phenylenediacetic acid (H2pda), formulated as Zn(trans-pda) (1a), Mn(H2O)2(trans-pda) (1b), [M(cis-pda)(4,4′-bipy)]·H2O (M = Zn (2a), Co (2b), Cd (2c); H2pda = 1,4-phenylenediacetic acid; 4,4′-bipy = 4,4′-bipyridine), are reported. The crystal structures of the as-synthesized complexes were determined by single-crystal X-ray diffraction analyses. Complexes 1aand 1bhave similar three-dimensional (3-D) network structures built by tetrahedral Zn nodes (for 1a) or octahedral Mn nodes (for 1b) and trans-pda2−bridges. Complexes 2a, 2b, and 2cpossess similar two-dimensional (2-D) layered structures constructed from interconnecting metal-cis-pda2−double chains by 4,4′-bipy ligands. It is interesting that conformation of the flexible pda2−ligand is modulated in presence of the rigid 4,4′-bipy ligand. The trans-pda2−ligand was typically isolated in a single pda2−system whereas the cis-pda2−ligand was observed in a mixed pda2−/4,4′-bipy system. Furthermore, the dimensionalities of the complexes vary from 3-D (1aand 1b) to 2-D (2a, 2b, and 2c) when auxiliary 4,4′-bipy ligands were introduced. The photoluminescent studies on solid-state samples of complexes 1a, 2aand 2cindicate that the complexes exhibit intense fluorescent emissions at room temperature. [ABSTRACT FROM AUTHOR]

Two cationic iridium(iii) complexes with bright green and red emissions were demonstrated as phosphorescent dyes for living cell imaging. In particular, their exclusive staining in cytoplasm, low cytotoxicity and reduced photobleaching, as well as cell membrane permeability, make the two complexes promising candidates for the design of specific bioimaging agents. [ABSTRACT FROM AUTHOR]

The quantitative use of cone beam computed tomography (CBCT) in radiation therapy is limited by severe shading artifacts, even with system embedded correction. We recently proposed effective shading correction methods, using planning CT (pCT) as prior information to estimate low-frequency errors in either the projection domain or image domain. In this work, we further improve the clinical practicality of our previous methods by removing the requirement of prior pCT images. Clinical CBCT images are typically composed of a limited number of tissues. By utilizing the low frequency characteristic of shading distribution, we first generate a ‘shading-free’ template image by enforcing uniformity on CBCT voxels of the same tissue type via a technique named partitioned tissue classification. Only a small subset of voxels in the template image are used in the correction process to generate sparse samples of shading artifacts. Local filtration, a Fourier transform based algorithm, is employed to efficiently process the sparse errors to compute a full-field distribution of shading artifacts for CBCT correction. We evaluate the method’s performance using an anthropomorphic pelvis phantom and 6 pelvis patients. The proposed method improves the image quality of CBCT for both phantom and patients to a level matching that of pCT. On the pelvis phantom, the signal non-uniformity (SNU) is reduced from 12.11% to 3.11% and 8.40% to 2.21% on fat and muscle, respectively. The maximum CT number error is reduced from 70 to 10 HU and 73 to 11 HU on fat and muscle, respectively. On patients, the average SNU is reduced from 9.22% to 1.06% and 11.41% to 1.67% on fat and muscle, respectively. The maximum CT number error is reduced from 95 to 9 HU and 88 to 8 HU on fat and muscle, respectively. The typical processing time for one CBCT dataset is about 45 s on a standard PC. [ABSTRACT FROM AUTHOR]

Monte Carlo simulations were used to investigate large-angle x-ray scatter at design energy of 25 keV during small field of view (9.6 cm × 5 cm) differential phase contrast imaging of the breast using Talbot–Lau interferometry. Homogenous, adipose and fibroglandular breasts of uniform thickness ranging from 2 to 8 cm encompassing the field of view were modeled. Theoretically determined transmission efficiencies of the gratings were used to validate the Monte Carlo simulations, followed by simulations to determine the x-ray scatter reaching the detector. The recorded x-ray scatter was classified into x-ray photons that underwent at least one Compton interaction (incoherent scatter) and Rayleigh interaction alone (coherent scatter) for further analysis. Monte Carlo based estimates of transmission efficiencies showed good correspondence with theoretical estimates. Scatter-to-primary ratio increased with increasing breast thickness, ranging from 0.11 to 0.22 for 2–8 cm thick adipose breasts and from 0.12 to 0.28 for 2–8 cm thick fibroglandular breasts. The analyzer grating reduced incoherent scatter by ~18% for 2 cm thick adipose breast and by ~35% for 8 cm thick fibroglandular breast. Coherent scatter was the dominant contributor to the total scatter. Coherent-to-incoherent scatter ratio ranged from 2.2 to 3.1 for 2–8 cm thick adipose breasts and from 2.7 to 3.4 for 2–8 cm thick fibroglandular breasts. [ABSTRACT FROM AUTHOR]