Effects Of Aberrations Research Articles

Design of a histotripsy array for the treatment of intracerebral hemorrhage

Histotripsy is a focused ultrasound technique using short, high amplitude pulses to generate targeted cavitation. Recently, the feasibility to treat blood clots through human skulls with histotripsy has been shown in vitro. The purpose of this study was to evaluate acoustic parameters for developing an optimized array design for the treatment of intracerebral hemorrhage (ICH) with histotripsy. The main performance criteria were to achieve a large electronic focal steering range (≥ 20 mm) and an ability to correct aberration through the skull. A hemispherical aperture of 150 mm radius was considered with modular elements to allow for arbitrary insertion of a catheter hydrophone to perform aberration correction. The attenuation at discrete frequencies from 250 kHz–2 MHz was measured through excised human skulls (n = 7) along with effects of incidence angle and aberration to optimize the operating frequency. Different piezoelectric materials were tested to optimize the peak-output, transduction efficiency, and durability at high PRF. One of the best performers, 17 mm square PZ36 material at 700 kHz, was found to produce at least 1.5 MPa free field at PRFs of 1 kHz. Finally, simulation showed that an optimally packed array configuration using 360 modules should be able to achieve an effective steering range of at least ±20 mm through the skull.

Peripheral resolution and contrast sensitivity: effects of monochromatic and chromatic aberrations.

Correction and manipulation of peripheral refractive errors are indispensable for people with central vision loss and in optical interventions for myopia control. This study investigates further enhancements of peripheral vision by compensating for monochromatic higher-order aberrations (with an adaptive optics system) and chromatic aberrations (with a narrowband green filter, 550 nm) in the 20° nasal visual field. Both high-contrast detection cutoff and contrast sensitivity improved with optical correction. This improvement was most evident for gratings oriented perpendicular to the meridian due to asymmetric optical errors. When the natural monochromatic higher-order aberrations are large, resolution of 10% contrast oblique gratings can also be improved with correction of these errors. Though peripheral vision is mainly limited by refractive errors and neural factors, higher-order aberration correction beyond conventional refractive errors can still improve peripheral vision under certain circumstances.

MiR-449a-5p mediates mitochondrial dysfunction and phenotypic transition by targeting Myc in pulmonary arterial smooth muscle cells.

MicroRNAs have been considered to participate in pulmonary arterial hypertension (PAH) and regulate numerous disease pathways in pulmonary vasculature. However, the molecular role in the pathologies has not yet been fully uncovered, particularly in the view of energy metabolism and vascular smooth muscle cell phenotypic regulation. Here, several altered miRNAs are founded in genome-wide miRNA sequencing analysis, in which miR-449a-5p was identified as a probable candidate in hypoxic PAH and verified such a decreasing trend. Moreover, we identify that miR-449a-5p plays critical role in both mitochondria metabolic dysfunction and phenotype transformation of pulmonary arterial smooth muscle cells. Subsequently, we initiate that the transcription factor Myc, which is negatively regulated by miR-449a-5p, results in the aberrant effects contributing to pulmonary arterial smooth muscle cell proliferation. Taken together, we demonstrated that the miR-449a-5p/Myc axis is indispensable for the development and progression of PAH. These results may serve as a significant implication for understanding and treatment of PAH. KEY MESSAGES: • The downregulation of miR-449a-5p occurs in both PAH-PAs and hypoxic PASMCs. • MiR-449a-5p is involved in hypoxia-induced mitochondria dysfunction of PASMCs. • MiR-449a-5p inhibits hypoxic phenotypic transition and proliferation of PASMCs. • The aberrant effects of MiR-449a-5p depend on downstream transcription factor Myc. • Myc contributes to mitochondria dysfunction and phenotype transformation in PAH.

Effect of Crystalline Lens Aberrations on Adaptive Optics Simulation of Intraocular Lenses.

To evaluate the impact of the lens aberrations on the adaptive optics visual simulation of pseudophakic intraocular lens (IOL) profiles. In 20 right phakic eyes, lens higher order aberrations (HOAs) were calculated as the whole eye minus the corneal aberrations. Visual simulation using low and high contrast corrected distance visual acuity (CDVA) testing was carried out with the VAO instrument (Voptica, SL, Murcia, Spain), considering three optical conditions of the lens: removing HOA (no lens-HOA), removing spherical aberration (no lens-SA), and with lens HOA (natural condition). In addition, a through-focus visual simulation of a trifocal diffractive IOL profile with high contrast CDVA was also measured in two conditions: no lens-HOA and natural condition. Three different pupil sizes (3, 4.5, and 6 mm) were tested for all conditions. There were no significant intersubject differences between the three optical conditions and in the IOL simulation for all pupil sizes (P > .05). For 4.5- and 6-mm pupils, mean VA values of the no-lens SA and no lens-HOA conditions were similar and slightly worse than those of the natural condition. Individual differences between the no lens-HOA condition and the other two optical conditions, estimated as 95% limits of agreement, were acceptable for 3-mm pupil but worse as pupil diameter increased. The effect of lens aberrations on visual simulation is imperceptible for a small pupil diameter of 3 mm. Although the increment of pupil size increases the probability of patients with significant visual impact of lens HOAs, the mean intersubject VA differences are negligible. [J Refract Surg. 2019;35(2):126-131.].

Genotoxic effects of silver nanoparticles with/without coating in human liver HepG2 cells and in mice.

With the rapid expansion of human exposure to silver nanoparticles (AgNPs), the genotoxicity screening is critical to the biosafety evaluation of nanosilver. This study assessed DNA damage and chromosomal aberration in the human hepatoma cell line (HepG2) as well as the effects on the micronucleus of bone marrow in mice induced by 20nm polyvinylpyrrolidone-coated nanosilver (PVP-AgNPs) and 20nm bare nanosilver (AgNPs). Our results showed that the two types of AgNPs, in doses of 20-160μg/mL, could cause genetic toxicological changes on HepG2 cells. The DNA damage degree of HepG2 cells in 20nm AgNPs was higher than that in 20nm PVP-AgNPs, while the 20nm PVP-AgNPs caused more serious chromosomal aberration than 20nm AgNPs. Both kinds of AgNPs caused genetic toxicity in a dose-dependent manner in HepG2 cells. In the micronucleus test on mouse bone marrow cells, in doses of 10, 50 and 250mg/kg body weight administered orally for 28days once a day, the two kinds of AgNPs have no obvious inhibitory effect on the mouse bone marrow cells, and the effect of chromosome aberration could be documented at the high dose of 250mg/kg. These results suggest that AgNPs have genotoxic effects in HepG2 cells and limited effects on bone marrow in mice; both in vitro and in vivo tests could be of great importance on the evaluation of genotoxicity of nanosilver. These findings can provide useful toxicological information that can help to assess genetic toxicity of nanosilver in vitro and in vivo.

像差对三镜型线聚焦滤波器效能影响的数值研究

像差对三镜型线聚焦滤波器效能影响的数值研究

Using the effect of longitudinal chromatic aberration for measuring distances from a single color photograph

A method for measuring the distance to photographic objects based on the longitudinal chromatic aberration at which the focal length of the lens and, consequently, the degree of defocusing of the photograph depend on the color range used during shooting is proposed. By performing the local analysis of the spatial Fourier spectrum of the image, which is differently defocused in different spectral ranges, distances are calculated in analytical form. A theoretical justification of the proposed method is provided, and the results of its practical application for measuring distances to objects of the scene with the help of its color photograph taken using an objective with pronounced chromatic aberration are presented.

Безаберрационная ширина углового спектра зондирующего слоистый объект поля в конфокальной микроскопии

The effect of the numerical aperture of a light beam probing an object on the value measured by a confocal interference microscope when determining the thickness of a layered object for the case of a significant effect on the signal of the spherical aberration arising in the probe beam at its propagation through an object has been theoretically and experimentally investigated. Taking into account the influence of spherical aberration on the signal the dependence of the measured value on the numerical aperture has been obtained. The criterion of the “aberration-free” propagation of the beam probing an object has been established and the condition under which the effect of spherical aberration on the signal of a confocal microscope can be neglected has been determined. An approximate analytical expression which allows to determine the “aberration-free” width of angular spectrum of the probing light beam taking into account the empirical correction factor has been obtained. The limits of applicability of the analytical dependence of the measured value on the numerical aperture, which was obtained earlier for the case of negligible influence of spherical aberration on the signal of a confocal microscope, have been determined.

Sevoflurane inhibits migration and invasion of colorectal cancer cells by regulating microRNA-34a/ADAM10 axis.

Sevoflurane is frequently used volatile anesthetic in cancer surgery. It has been suggested that treatment with sevoflurane could suppress migration and invasion of several human cancer cells in vitro. However, the effects of sevoflurane on colorectal cancer (CRC) remains largely unclear. In this study, CRC HCT116 and SW480 cells were treated by various concentrations of sevoflurane. MTT assay and Transwell assay were applied to evaluate the cell viability, migration and invasion abilities of CRC cell lines, respectively. Real-time quantitative PCR (RT-qPCR) was used to examine the expression level of miR-34a, and western blot assay was employed to detect the protein level of ADAM10. The target interaction between miR-34a and ADAM10 was verified through bioinformatics analysis, luciferase reporter gene assay system. We found Aberrant inhibitory effects induced by sevoflurane on the cell viability, migration and invasion abilities of HCT116 and SW480 cells in a dose-dependent manner were observed. Up-regulation of miR-34a strikingly suppressed the cell proliferation, migration and invasion abilities of the two cell lines. Sevoflurane could facilitate the miR-34a expression and its suppressor effects on CRC cells was reversed by pre-treatment with miR-34a inhibitors. ADAM10 was identified as a downstream gene of miR-34a, and down-regulated by miR-34a. Overexpression of ADAM10 reverted both miR-34a and sevoflurane-induced repression in the cell proliferation, migration and invasion abilities of CRC cells. Our data showed Sevoflurane inhibits the migration and invasion of colorectal cancer cells by regulating microRNA-34a/ADAM10 axis.

On the Geometry of Curvature Radiation and Implications for Subpulse Drifting

Abstract The phenomenon of subpulse drifting offers unique insights into the emission geometry of pulsars, and is commonly interpreted in terms of a rotating carousel of “spark” events near the stellar surface. We develop a detailed geometric model for the emission columns above a carousel of sparks that is entirely calculated in the observer’s inertial frame, and which is consistent with the well-understood rotational effects of aberration and retardation. We explore the observational consequences of the model, including (1) the appearance of the reconstructed beam pattern via the cartographic transform, and (2) the morphology of drift bands and how they might evolve as a function of frequency. The model, which is implemented in the software package PSRGEOM, is applicable to a wide range of viewing geometries, and we illustrate its implications using PSRs B0809+74 and B2034+19 as examples. Some specific predictions are made with respect to the difference between subpulse evolution and microstructure evolution, which provides a way to further test our model.

Software compensation for chromatic aberration effects in color photos

Software compensation for chromatic aberration effects in color photos

Using the longitudinal chromatic aberration effect to measure distances from a single color photo

Using the longitudinal chromatic aberration effect to measure distances from a single color photo

Disruptions in White Matter Maturation and Mediation of Cognitive Development in Youths on the Psychosis Spectrum

BackgroundPsychosis onset typically occurs in adolescence, and subclinical psychotic experiences peak in adolescence. Adolescence is also a time of critical neural and cognitive maturation. Using cross-sectional data from the Philadelphia Neurodevelopmental Cohort, we examined whether regional white matter (WM) development is disrupted in youths with psychosis spectrum (PS) features and whether WM maturation mediates the relationship between age and cognition in typically developing (TD) youths and youths with PS features. MethodsWe examined WM microstructure, as assessed via diffusion tensor imaging, in 670 individuals (age 10–22 years; 499 TD group, 171 PS group) by using tract-based spatial statistics. Multiple regressions were used to evaluate age × group interactions on regional WM indices. Mediation analyses were conducted on four cognitive domains—executive control, complex cognition, episodic memory, and social cognition—using a bootstrapping approach. ResultsThere were age × group interactions on fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and retrolenticular internal capsule. Follow-up analyses revealed these effects were significant in both hemispheres. Bilateral SLF FA mediated the relationship between age and complex cognition in the TD group, but not the PS group. Regional FA did not mediate the age-associated increase in any of the other cognitive domains. ConclusionsOur results showed aberrant age-related effects in SLF and retrolenticular internal capsule FA in youths with PS features. SLF development supports emergence of specific higher-order cognitive functions in TD youths, but not in youths with PS features. Future mechanistic explanations for these relationships could facilitate development of earlier and refined targets for therapeutic interventions.

Apodization pupils: design and performance (review)

Apodization applied to the pupil functions was widely used for the light field manipulation in the focal region of the optical focusing systems. Apodization pupils were divided into three categories by the structure type, i.e. slit, circular and complex pupil functions. For one-dimensional (slit type) apodization functions, the point spread function was obtained with suppressed sidelobes. The magnitude of reduction of the sidelobes was found to increased by the amplitude apodization across the slit function. For apodized circular pupil functions, the axial resolution of the optical systems was improved, and it was very helpful to improve the two-point resolution in the presence of optical aberrations such as defocus and spherical aberration. For complex apodized pupil functions, the full width at half maximum (FWHM) of the point spread function (PSF) was obtained less than that of the Airy PSF. The study proved that, within certain conditions, the complex apodizer was effective in removing the sidelobes from the aberrated impulse response (or PSF). In this review, a systematic study was performed in which the effect of aberrations and the complex apodization were used to improve the performance of the optical systems for resolving the two closely located point-sources under the incoherent, partially coherent and fully coherent light illumination. The concepts of the amplitude and phase diffractive optical elements were applied to reduce the size of the focal spot at tight focusing of differently polarized laser beams. This technique was also applied to increase the resolution beyond the diffraction limit for the composite image intensity distribution of the far-field objects formed by the incoherent optical system.

Analysis of aberrations and performance evaluation of adaptive optics in two-photon light-sheet microscopy

Abstract Two-photon light-sheet microscopy (TP-LSM) system performance is greatly degraded by specimen-induced aberrations in illumination path, which limit the field of view, axial resolution and excitation efficiency of the system. Adaptive optics (AO) is an effective method for attenuating these effects. For the design and evaluation of an AO system, a comprehensive analysis of the effects of aberrations is needed. In this paper, a TP-LSM system is simulated, and new indexes based on integral intensity are introduced for the evaluation of an aberrated light-sheet. Then, the influences of each Zernike mode and random aberrations on the illumination path of the TP-LSM system are investigated with a numerical simulation method. Results show that high-order aberrations have little effect on the axial resolution and excitation efficiency of the system and only low-order components require correction. The random aberrations varied in strength with the depth of the specimens, so the number of corrected Zernike modes is variable. A general formula is generated for the estimation of the number of modes that should be detected and corrected under different aberrations and different numerical aperture of the objective. The results can provide important guidance in the design and evaluation of AO units for TP-LSM systems.

The Hierarchical Modular Structure of HER2+ Breast Cancer Network.

HER2-enriched breast cancer is a complex disease characterized by the overexpression of the ERBB2 amplicon. While the effects of this genomic aberration on the pathology have been studied, genome-wide deregulation patterns in this subtype of cancer are also observed. A novel approach to the study of this malignant neoplasy is the use of transcriptional networks. These networks generally exhibit modular structures, which in turn may be associated to biological processes. This modular regulation of biological functions may also exhibit a hierarchical structure, with deeper levels of modular organization accounting for more specific functional regulation. In this work, we identified the most probable (maximum likelihood) model of the hierarchical modular structure of the HER2-enriched transcriptional network as reconstructed from gene expression data, and analyzed the statistical associations of modules and submodules to biological functions. We found modular structures, independent from direct ERBB2 amplicon regulation, involved in different biological functions such as signaling, immunity, and cellular morphology. Higher resolution submodules were identified in more specific functions, such as micro-RNA regulation and the activation of viral-like immune response. We propose the approach presented here as one that may help to unveil mechanisms involved in the development of the pathology.

P3.03-06 Differentially Expressed microRNAs in Lung Adenocarcinoma Invert Effects of Copy Number Aberrations of Prognostic Genes

Significant associations between chromosomal copy number aberrations (CNAs) and differential gene expression have been found across many cancers. However, significantly downregulated genes have been often found to reside within chromosomal regions with increased number of copies and vice versa, creating a paradoxical signal. This phenomenon was usually ignored as a noise, but can potentially be a consequence of interference of other regulatory mechanisms controlling mRNA transcription. To explore existence of such paradoxes in lung adenocarcinoma (LUAD), we performed integrative analysis of 1,937 tumour and normal tissue samples, comprising copy number aberrations, gene expression and microRNA expressions data and conducted meta-analysis of 9 microRNA expression studies. We identified and validated 75 “paradoxical” genes whose differential expression consistently contrasted with aberrations of their copy numbers. Of these, 41 genes (p < 0.001) are prognostic and form a clinically relevant signature. Interestingly, differential expression of 19 microRNAs that are frequently deregulated in LUAD, explains observed paradoxes. Our results show that deregulation of paradoxical genes is crucial in LUAD and their expression pattern is maintained epigenetically, defying gene copy number status. Our work highlights importance of large integrative analysis of diverse biological data and the need to examine phenomena that contrast the established knowledge.

Bone Mineral Density is Unaltered in Women with Polycystic Ovary Syndrome.

The effects of endocrine aberrations associated with polycystic ovary syndrome (PCOS) on bone mineral density (BMD) in young women is a matter of debate. To compare BMD in young women with PCOS to age and body mass index (BMI) matched controls and to elucidate its correlation to BMI, insulin resistance and serum testosterone. We recruited 60 women with PCOS aged 14-24 years, diagnosed based on Rotterdam 2003 criteria, and 58 age matched controls. BMD was measured by dual energy X-ray absorptiometry. In addition, these subjects underwent biochemical and hormonal analysis including oral glucose tolerance test, calculation of Homeostatic Model Assessment-Insulin Resistance Index, measurement of serum thyroxine, thyrotropin, prolactin, total testosterone, dehydroepiandrosterone sulfate, follicular phase luteinizing hormone and follicle stimulating hormone. There was no difference of BMD between women with PCOS and control women (1.103±0.08 vs 1.126±0.083 g/cm2; p=0.122). In subgroup analysis based on BMI, BMD in obese women with PCOS was significantly higher than their overweight and lean counterparts at lumbar spine (p<0.001), neck of femur (p=0.005) and total hip (p<0.001). BMD was not different at any site between oligomenorrheic and non-oligomenorrheic women with PCOS. It positively correlated with BMI, waist and hip circumference in women with PCOS. No correlation was found with HOMA-IR or Testosterone. BMI is the most important determinant of BMD in women with PCOS. BMD is not different between healthy young women and those with PCOS.

Creating correct blur and its effect on accommodation.

Blur occurs naturally when the eye is focused at one distance and an object is presented at another distance. Computer-graphics engineers and vision scientists often wish to create display images that reproduce such depth-dependent blur, but their methods are incorrect for that purpose. They take into account the scene geometry, pupil size, and focal distances, but do not properly take into account the optical aberrations of the human eye. We developed a method that, by incorporating the viewer's optics, yields displayed images that produce retinal images close to the ones that occur in natural viewing. We concentrated on the effects of defocus, chromatic aberration, astigmatism, and spherical aberration and evaluated their effectiveness by conducting experiments in which we attempted to drive the eye's focusing response (accommodation) through the rendering of these aberrations. We found that accommodation is not driven at all by conventional rendering methods, but that it is driven surprisingly quickly and accurately by our method with defocus and chromatic aberration incorporated. We found some effect of astigmatism but none of spherical aberration. We discuss how the rendering approach can be used in vision science experiments and in the development of ophthalmic/optometric devices and augmented- and virtual-reality displays.

Normal Breast-Derived Epithelial Cells with Luminal and Intrinsic Subtype-Enriched Gene Expression Document Interindividual Differences in Their Differentiation Cascade.

Cell-type origin is one of the factors that determine molecular features of tumors, but resources to validate this concept are scarce because of technical difficulties in propagating major cell types of adult organs. Previous attempts to generate such resources to study breast cancer have yielded predominantly basal-type cell lines. We have created a panel of immortalized cell lines from core breast biopsies of ancestry-mapped healthy women that form ductal structures similar to normal breast in 3D cultures and expressed markers of major cell types, including the luminal-differentiated cell-enriched ERα-FOXA1-GATA3 transcription factor network. We have also created cell lines from PROCR (CD201)+/EpCAM- cells that are likely the "normal" counterpart of the claudin-low subtype of breast cancers. RNA-seq and PAM50-intrinsic subtype clustering identified these cell lines as the "normal" counterparts of luminal A, basal, and normal-like subtypes and validated via immunostaining with basal-enriched KRT14 and luminal-enriched KRT19. We further characterized these cell lines by flow cytometry for distribution patterns of stem/basal, luminal-progenitor, mature/differentiated, multipotent PROCR+ cells, and organogenesis-enriched epithelial/mesenchymal hybrid cells using CD44/CD24, CD49f/EpCAM, CD271/EpCAM, CD201/EpCAM, and ALDEFLUOR assays and E-cadherin/vimentin double staining. These cell lines showed interindividual heterogeneity in stemness/differentiation capabilities and baseline activity of signaling molecules such as NF-κB, AKT2, pERK, and BRD4. These resources can be used to test the emerging concept that genetic variations in regulatory regions contribute to widespread differences in gene expression in "normal" conditions among the general population and can delineate the impact of cell-type origin on tumor progression.Significance: In addition to providing a valuable resource for the breast cancer research community to investigate cell-type origin of different subtypes of breast cancer, this study highlights interindividual differences in normal breast, emphasizing the need to use "normal" cells from multiple sources as controls to decipher the effects of cancer-specific genomic aberrations. Cancer Res; 78(17); 5107-23. ©2018 AACR.