scholarly journals Towards Transabdominal Functional Photoacoustic Imaging of the Placenta: Improvement in Imaging Depth Through Optimization of Light Delivery

2021 ◽  
Author(s):  
Kristie Huda ◽  
Kenneth F. Swan ◽  
Cecilia T. Gambala ◽  
Gabriella C. Pridjian ◽  
Carolyn L. Bayer
Keyword(s):  
Delivery System ◽  
Light Propagation ◽  
Ex Vivo ◽  
Photoacoustic Imaging ◽  
Incidence Angle ◽  
Incident Angle ◽  
Placental Tissue ◽  
Light Delivery ◽  
Imaging Depth ◽  
The Impact

AbstractFunctional photoacoustic imaging of the placenta could provide an innovative tool to diagnose preeclampsia, monitor fetal growth restriction, and determine the developmental impacts of gestational diabetes. However, transabdominal photoacoustic imaging is limited in imaging depth due to the tissue’s scattering and absorption of light. The aim of this paper was to investigate the impact of geometry and wavelength on transabdominal light delivery. Our methods included the development of a multilayer model of the abdominal tissue and simulation of the light propagation using Monte Carlo methods. A bifurcated light source with varying incident angle of light, distance between light beams, and beam area was simulated to analyze the effect of light delivery geometry on the fluence distribution at depth. The impact of wavelength and the effects of variable thicknesses of adipose tissue and muscle were also studied. Our results showed that the beam area plays a major role in improving the delivery of light to deep tissue, in comparison to light incidence angle or distance between the bifurcated fibers. Longer wavelengths, with incident fluence at the maximum permissible exposure limit, also increases fluence within deeper tissue. We validated our simulations using a commercially available light delivery system and ex vivo human placental tissue. Additionally, we compared our optimized light delivery to a commercially available light delivery system, and conclude that our optimized geometry could improve imaging depth more than 1.6×, bringing the imaging depth to within the needed range for transabdominal imaging of the human placenta.

scholarly journals Design of optimal light delivery system for co-registered transvaginal ultrasound and photoacoustic imaging of ovarian tissue

2015 ◽  
Vol 3 (3) ◽  
pp. 114-122 ◽  
Author(s):  
Hassan S. Salehi ◽  
Patrick D. Kumavor ◽  
Hai Li ◽  
Umar Alqasemi ◽  
Tianheng Wang ◽  
...  
Keyword(s):  
Delivery System ◽  
Photoacoustic Imaging ◽  
Ovarian Tissue ◽  
Transvaginal Ultrasound ◽  
Light Delivery

Impact of Fabrication and Operation Errors on Super-Focusing Performance of a Nanoslit-Based Metalens

2021 ◽  
Vol 16 (7) ◽  
pp. 1115-1119
Author(s):  
Shun Zhou ◽  
Yechuan Zhu ◽  
Shaobo Ge ◽  
Fei Xie ◽  
Na Jin ◽  
...  
Keyword(s):  
Transverse Electric ◽  
Incidence Angle ◽  
Incident Angle ◽  
Incident Light ◽  
Polarized Light ◽  
Super Resolution ◽  
Optical Manipulation ◽  
Optical Components ◽  
Operating Wavelength ◽  
The Impact

Metasurfaces with optical manipulation at subwavelength resolution show promises for developing ultrathin and flat optical components, attracting great interest from the optical scientific community. In our recent work, a metalens has demonstrated a special capability of quasi-far-field super-resolution focusing, which comprised a metallic nanoslit array with the incidence of a transverse-electric (TE) polarized light. In this paper, in order to guide practical fabrication and operation of a device, we perform a study on the metalens to analyze the impact of many imperfections on the super-resolution focusing capability. We take fabrication and operation errors into account, including errors in nanoslit width, metal film thickness, operating wavelength, polarization and incident angle of incident light. Numerical results illustrate that the sensitivity of the metalens focusing performance to each error is different. To be specific, the focusing performance of the metalens is considerably susceptible to the error in the incidence angle. Therefore, we not only need to fabricate the metalens device precisely, but also need to ensure that the working conditions agree well with the design, so as to achieve the desired focusing performance. Our research offers a valuable guide for the realization of the super-resolution focusing technology in practice.

scholarly journals 231 Impact of Brachyspira hyodysentariae on intestinal function and integrity

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 116-116
Author(s):  
Emma T Helm ◽  
Susanne J Lin ◽  
Nicholas Gabler ◽  
Eric R Burrough
Keyword(s):  
Ex Vivo ◽  
Potato Starch ◽  
Nutrient Digestibility ◽  
High Morbidity ◽  
Post Inoculation ◽  
Intestinal Function ◽  
Treatment Groups ◽  
Intestinal Integrity ◽  
Beet Pulp ◽  
The Impact

Abstract Swine dysentery (SD) induced by Brachyspira hyodysentariae (Bhyo) causes colitis and mucohemorrhagic diarrhea in grow-finish pigs, however little is known about the physiological changes that occur to the gastrointestinal tract during Bhyo infection. Thus, the objective of this study was to evaluate the impact of a Bhyo challenge on intestinal function and integrity of pigs fed two divergent diets. A total of 36 Bhyo negative gilts (24.3 ± 3.6 kg BW) were selected and assigned to one of three treatment groups (n=12 pigs/trt): 1) Bhyo negative, 20% DDGS diet (CON), 2) Bhyo challenged, 20% DDGS diet (DDGS), and 3) Bhyo challenged, 10% DDGS, 5% beet pulp and 5% resistant potato starch diet (RS). Pigs were fed diets 21 days prior to challenge and on days post inoculation (dpi) 0 and 1, pigs were inoculated with Bhyo or sham. Fecal samples were collected for ATTD and pigs were euthanized for colon collection within 72 hours of initial observation of clinical SD, or at the end of the study (dpi 10-16). Tissues were assessed for ex vivo measures of intestinal integrity and mitochondrial function. The challenge resulted in high morbidity, with 88% of DDGS and RS pigs developing clinical SD. Colon transepithelial resistance was increased in DDGS pigs compared with CON and RS pigs (P=0.005), and colon macromolecule permeability was reduced in both DDGS and RS pigs compared with CON pigs (P=0.006), likely due to mucoid discharge. Colonic mitochondrial oxygen consumption was not impacted by treatment (P >0.10). Further, ATTD of DM, OM, N, and GE were reduced in DDGS pigs compared with CON pigs (P< 0.001), whilst nutrient digestibility was not reduced in RS pigs. Taken together, these data show Bhyo does not appear to reduce ex vivo colonic integrity. Further, the RS diet may reduce severity of a Bhyo challenge.

scholarly journals Histological, Biomechanical, and Biological Properties of Genipin-Crosslinked Decellularized Peripheral Nerves

2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Nerve Repair ◽  
Wistar Rat ◽  
Biomechanical Properties ◽  
Biological Properties ◽  
Suitable Alternative ◽  
Promising Alternative ◽  
Histological Pattern ◽  
The Impact

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.

scholarly journals Towards Including Dynamic Vegetation Parameters in the EUMETSAT H SAF ASCAT Soil Moisture Products

2021 ◽  
Vol 13 (8) ◽  
pp. 1463
Author(s):  
Susan C. Steele-Dunne ◽  
Sebastian Hahn ◽  
Wolfgang Wagner ◽  
Mariette Vreugdenhil
Keyword(s):  
Soil Moisture ◽  
Interannual Variability ◽  
Incidence Angle ◽  
Pearson Correlation ◽  
The United States ◽  
Research Network ◽  
Window Width ◽  
High Frequency Variability ◽  
Vegetation Parameters ◽  
The Impact

The TU Wien Soil Moisture Retrieval (TUW SMR) approach is used to produce several operational soil moisture products from the Advanced Scatterometer (ASCAT) on the Metop series of satellites as part of the EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H SAF). The incidence angle dependence of backscatter is described by a second-order Taylor polynomial, the coefficients of which are used to normalize ASCAT observations to the reference incidence angle of 40∘ and for correcting vegetation effects. Recently, a kernel smoother was developed to estimate the coefficients dynamically, in order to account for interannual variability. In this study, we used the kernel smoother for estimating these coefficients, where we distinguished for the first time between their two uses, meaning that we used a short and fixed window width for the backscatter normalisation while we tested different window widths for optimizing the vegetation correction. In particular, we investigated the impact of using the dynamic vegetation parameters on soil moisture retrieval. We compared soil moisture retrievals based on the dynamic vegetation parameters to those estimated using the current operational approach by examining their agreement, in terms of the Pearson correlation coefficient, unbiased RMSE and bias with respect to in situ soil moisture. Data from the United States Climate Research Network were used to study the influence of climate class and land cover type on performance. The sensitivity to the kernel smoother half-width was also investigated. Results show that estimating the vegetation parameters with the kernel smoother can yield an improvement when there is interannual variability in vegetation due to a trend or a change in the amplitude or timing of the seasonal cycle. However, using the kernel smoother introduces high-frequency variability in the dynamic vegetation parameters, particularly for shorter kernel half-widths.

scholarly journals Gut-Ex-Vivo system as a model to study gluten response in celiac disease

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mara Gagliardi ◽  
Nausicaa Clemente ◽  
Romina Monzani ◽  
Luca Fusaro ◽  
Eleonora Ferrari ◽  
...  
Keyword(s):  
Celiac Disease ◽  
Intestinal Epithelium ◽  
Complex Disease ◽  
Ex Vivo ◽  
Dynamic Condition ◽  
Model Systems ◽  
In Vivo Models ◽  
Effective Manner ◽  
Junction Protein ◽  
The Impact

AbstractCeliac disease (CD) is a complex immune-mediated chronic disease characterized by a consistent inflammation of the gastrointestinal tract induced by gluten intake in genetically predisposed individuals. Although initiated by the interaction between digestion-derived gliadin, a gluten component, peptides, and the intestinal epithelium, the disorder is highly complex and involving other components of the intestine, such as the immune system. Therefore, conventional model systems, mainly based on two- or three-dimension cell cultures and co-cultures, cannot fully recapitulate such a complex disease. The development of mouse models has facilitated the study of different interacting cell types involved in the disorder, together with the impact of environmental factors. However, such in vivo models are often expensive and time consuming. Here we propose an organ ex vivo culture (gut-ex-vivo system) based on small intestines from gluten-sensitive mice cultivated in a dynamic condition, able to fully recapitulate the biochemical and morphological features of the mouse model exposed to gliadin (4 weeks), in 16 h. Indeed, upon gliadin exposure, we observed: i) a down-regulation of cystic fibrosis transmembrane regulator (CFTR) and an up-regulation of transglutaminase 2 (TG2) at both mRNA and protein levels; ii) increased intestinal permeability associated with deregulated tight junction protein expression; iii) induction and production of pro-inflammatory cytokines such as interleukin (IL)-15, IL-17 and interferon gamma (IFNγ); and iv) consistent alteration of intestinal epithelium/villi morphology. Altogether, these data indicate that the proposed model can be efficiently used to study the pathogenesis of CD, test new or repurposed molecules to accelerate the search for new treatments, and to study the impact of the microbiome and derived metabolites, in a time- and cost- effective manner.

scholarly journals Cell–cell coupling and DNA methylation abnormal phenotypes in the after-hours mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Federico Tinarelli ◽  
Elena Ivanova ◽  
Ilaria Colombi ◽  
Erica Barini ◽  
Edoardo Balzani ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Neuronal Networks ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Neuronal Cultures ◽  
Functional Impairments ◽  
After Hours ◽  
The Impact

Abstract Background DNA methylation has emerged as an important epigenetic regulator of brain processes, including circadian rhythms. However, how DNA methylation intervenes between environmental signals, such as light entrainment, and the transcriptional and translational molecular mechanisms of the cellular clock is currently unknown. Here, we studied the after-hours mice, which have a point mutation in the Fbxl3 gene and a lengthened circadian period. Methods In this study, we used a combination of in vivo, ex vivo and in vitro approaches. We measured retinal responses in Afh animals and we have run reduced representation bisulphite sequencing (RRBS), pyrosequencing and gene expression analysis in a variety of brain tissues ex vivo. In vitro, we used primary neuronal cultures combined to micro electrode array (MEA) technology and gene expression. Results We observed functional impairments in mutant neuronal networks, and a reduction in the retinal responses to light-dependent stimuli. We detected abnormalities in the expression of photoreceptive melanopsin (OPN4). Furthermore, we identified alterations in the DNA methylation pathways throughout the retinohypothalamic tract terminals and links between the transcription factor Rev-Erbα and Fbxl3. Conclusions The results of this study, primarily represent a contribution towards an understanding of electrophysiological and molecular phenotypic responses to external stimuli in the Afh model. Moreover, as DNA methylation has recently emerged as a new regulator of neuronal networks with important consequences for circadian behaviour, we discuss the impact of the Afh mutation on the epigenetic landscape of circadian biology.

scholarly journals Development and Evaluation of Docetaxel-Phospholipid Complex Loaded Self-Microemulsifying Drug Delivery System: Optimization and In Vitro/Ex Vivo Studies

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 544
Author(s):  
Miao Wang ◽  
Sung-Kyun You ◽  
Hong-Ki Lee ◽  
Min-Gu Han ◽  
Hyeon-Min Lee ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Delivery System ◽  
Anticancer Agents ◽  
Lipid Membrane ◽  
Ex Vivo ◽  
System Optimization ◽  
Raw Material ◽  
Phospholipid Complex ◽  
Low Solubility

Docetaxel (DTX) has clinical efficacy in the treatment of breast cancer, but it is difficult to develop a product for oral administration, due to low solubility and permeability. This study focused on preparing a self-microemulsifying drug delivery system (SME) loaded with DTX-phospholipid complex (DTX@PLC), to improve the dissolution and gastrointestinal (GI) permeability of DTX. A dual technique combining the phospholipid complexation and SME formulation described as improving upon the disadvantages of DTX has been proposed. We hypothesized that the complexation of DTX with phospholipids can improve the lipophilicity of DTX, thereby increasing the affinity of the drug to the cell lipid membrane, and simultaneously improving permeability through the GI barrier. Meanwhile, DTX@PLC-loaded SME (DTX@PLC-SME) increases the dissolution and surface area of DTX by forming a microemulsion in the intestinal fluid, providing sufficient opportunity for the drug to contact the GI membrane. First, we prepared DTX@PLC-SME by combining dual technologies, which are advantages for oral absorption. Next, we optimized DTX@PLC-SME with nanosized droplets (117.1 nm), low precipitation (8.9%), and high solubility (33.0 mg/g), which formed a homogeneous microemulsion in the aqueous phase. Dissolution and cellular uptake studies demonstrated that DTX@PLC-SME showed 5.6-fold higher dissolution and 2.3-fold higher DTX uptake in Caco-2 cells than raw material. In addition, an ex vivo gut sac study confirmed that DTX@PLC-SME improved GI permeability of DTX by 2.6-fold compared to raw material. These results suggested that DTX@PLC-SME can significantly overcome the disadvantages of anticancer agents, such as low solubility and permeability.

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