scholarly journals PAME: Plasmonic Assay Modeling Environment

Author(s):  
Adam S Hughes ◽  
Mark E. Reeves ◽  
Zhaowen Liu

Plasmonic assays are an important class of optical sensors that measure biomolecular interactions in real-time without the need for labeling agents, making them especially well-suited for clinical applications. Through the incorporation of nanoparticles and fiberoptics, these sensing systems have been successfully miniaturized and show great promise for in-situ probing and implantable devices, yet it remains challenging to derive meaningful, quantitative information from plasmonic responses. This is in part due to a lack of dedicated modeling tools, and therefore we introduce PAME, an open-source Python application for modeling plasmonic systems of bulk and nanoparticle-embedded metallic films. PAME combines aspects of thin-film solvers, nanomaterials and fiber-optics into an intuitive graphical interface. Some of PAME’s features include a simulation mode, a database of hundreds of materials, and an object-oriented framework for designing complex nanomaterials, such as a gold nanoparticles encased in a protein shell. An overview of PAME’s theory and design is presented, followed by example simulations of a fiberoptic refractometer, as well as protein binding to a multiplexed sensor composed of a mixed layer of gold and silver colloids. These results provide new insights into observed responses in reflectance biosensors.

2015 ◽  
Author(s):  
Adam S Hughes ◽  
Mark E. Reeves ◽  
Zhaowen Liu

Plasmonic assays are an important class of optical sensors that measure biomolecular interactions in real-time without the need for labeling agents, making them especially well-suited for clinical applications. Through the incorporation of nanoparticles and fiberoptics, these sensing systems have been successfully miniaturized and show great promise for in-situ probing and implantable devices, yet it remains challenging to derive meaningful, quantitative information from plasmonic responses. This is in part due to a lack of dedicated modeling tools, and therefore we introduce PAME, an open-source Python application for modeling plasmonic systems of bulk and nanoparticle-embedded metallic films. PAME combines aspects of thin-film solvers, nanomaterials and fiber-optics into an intuitive graphical interface. Some of PAME’s features include a simulation mode, a database of hundreds of materials, and an object-oriented framework for designing complex nanomaterials, such as a gold nanoparticles encased in a protein shell. An overview of PAME’s theory and design is presented, followed by example simulations of a fiberoptic refractometer, as well as protein binding to a multiplexed sensor composed of a mixed layer of gold and silver colloids. These results provide new insights into observed responses in reflectance biosensors.


Author(s):  
Jerrold L. Abraham

Inorganic particulate material of diverse types is present in the ambient and occupational environment, and exposure to such materials is a well recognized cause of some lung disease. To investigate the interaction of inhaled inorganic particulates with the lung it is necessary to obtain quantitative information on the particulate burden of lung tissue in a wide variety of situations. The vast majority of diagnostic and experimental tissue samples (biopsies and autopsies) are fixed with formaldehyde solutions, dehydrated with organic solvents and embedded in paraffin wax. Over the past 16 years, I have attempted to obtain maximal analytical use of such tissue with minimal preparative steps. Unique diagnostic and research data result from both qualitative and quantitative analyses of sections. Most of the data has been related to inhaled inorganic particulates in lungs, but the basic methods are applicable to any tissues. The preparations are primarily designed for SEM use, but they are stable for storage and transport to other laboratories and several other instruments (e.g., for SIMS techniques).


2001 ◽  
Vol 80 (3-4) ◽  
pp. 315-321 ◽  
Author(s):  
J.F. Cadorin ◽  
D. Jongmans ◽  
A. Plumier ◽  
T. Camelbeeck ◽  
S. Delaby ◽  
...  

AbstractTo provide quantitative information on the ground acceleration necessary to break speleothems, laboratory measurements on samples of stalagmite have been performed to study their failure in bending. Due to their high natural frequencies, speleothems can be considered as rigid bodies to seismic strong ground motion. Using this simple hypothesis and the determined mechanical properties (a minimum value of 0.4 MPa for the tensile failure stress has been considered), modelling indicates that horizontal acceleration ranging from 0.3 m/s2 to 100 m/s2 (0.03 to 10g) are necessary to break 35 broken speleothems of the Hotton cave for which the geometrical parameters have been determined. Thus, at the present time, a strong discrepancy exists between the peak accelerations observed during earthquakes and most of the calculated values necessary to break speleothems. One of the future research efforts will be to understand the reasons of the defined behaviour. It appears fundamental to perform measurements on in situ speleothems.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 879
Author(s):  
Kevin Cheng ◽  
Andrew Lin ◽  
Jeremy Yuvaraj ◽  
Stephen J. Nicholls ◽  
Dennis T.L. Wong

Radiomics, via the extraction of quantitative information from conventional radiologic images, can identify imperceptible imaging biomarkers that can advance the characterization of coronary plaques and the surrounding adipose tissue. Such an approach can unravel the underlying pathophysiology of atherosclerosis which has the potential to aid diagnostic, prognostic and, therapeutic decision making. Several studies have demonstrated that radiomic analysis can characterize coronary atherosclerotic plaques with a level of accuracy comparable, if not superior, to current conventional qualitative and quantitative image analysis. While there are many milestones still to be reached before radiomics can be integrated into current clinical practice, such techniques hold great promise for improving the imaging phenotyping of coronary artery disease.


2005 ◽  
Vol 875 ◽  
Author(s):  
Marc Legros ◽  
Gerhard Dehm ◽  
T. John Balk

AbstractTo investigate the origin of the high strength of thin films, in-situ cross-sectional TEM deformation experiments have been performed on several metallic films attached to rigid substrates. Thermal cycles, comparable to those performed using laser reflectometry, were applied to thin foils inside the TEM and dislocation motion was recorded dynamically on video. These observations can be directly compared to the current models of dislocation hardening in thin films. As expected, the role of interfaces is crucial, but, depending on their nature, they can attract or repel dislocations. When the film/interface holds off dislocations, experimental values of film stress match those predicted by the Nix-Freund model. In contrast, the attracting case leads to higher stresses that are not explained by this model. Two possible hardening scenarios are explored here. The first one assumes that the dislocation/interface attraction reduces dislocation mobility and thus increases the yield stress of the film. The second one focuses on the lack of dislocation nucleation processes in the case of attracting interfaces, even though a few sources have been observed in-situ.


Sensor Review ◽  
2018 ◽  
Vol 38 (2) ◽  
pp. 231-238 ◽  
Author(s):  
Yi Xiong ◽  
Xiaoguang Yang

Purpose The aim of this paper is threefold: first, to review the technological state of the art on tire sensor systems; second, to summarize basic methodologies and explore the potential of tire sensing for intelligent vehicle developments and third, to address challenges in the development of tire sensing systems and inspire future research in this field. Design/methodology/approach Nowadays, automotive industry is moving toward an intelligent and autonomous driving era with the assistance of sensing technology development, whereas tire-road conditions sensing and utilization are of great interest from the point of view of vehicle dynamics control, vehicle safety and vehicle performance evaluation. Findings Tire sensing is an emerging technology whereby sensor systems are installed on the tire to provide fundamental insights into tire-road interactions for ground vehicles and wheel robots. In the past two decades, tire sensing systems based on various sensor types have been proposed to offer the possibility to investigate tire-road interactions. Originality/value Instrumenting the tire with sensors, especially accelerometers and optical sensors, can sense the tire-road interactions and enhance the vehicle performance. The harsh environment inside tire cavity requires reliable, accurate, low weight, modularized and inexpensive sensors. Challenges, such as the data transmission, power management, lack of physics-based tire models need to be solved before the tire sensor becomes commercially viable for production vehicles.


2020 ◽  
Vol 53 (4) ◽  
pp. 1163-1166
Author(s):  
Karsten Mesecke ◽  
Winfried Malorny ◽  
Laurence N. Warr

This note describes an autoclave chamber developed and constructed by Anton Paar and its application for in situ experiments under hydrothermal conditions. Reactions of crystalline phases can be studied by successive in situ measurements on a conventional laboratory X-ray diffractometer with Bragg–Brentano geometry at temperatures <483 K and saturated vapour pressure <2 MPa. Variations in the intensity of X-ray diffraction reflections of both reactants and products provide quantitative information for studying the reaction kinetics of both dissolution and crystal growth. Feasibility is demonstrated by studying a cementitious mixture used for autoclaved aerated concrete production. During a period of 5.7 h at 466 K and 1.35 MPa, the crystallization of torbermorite and the partial consumption of quartz were monitored.


2021 ◽  
Author(s):  
Muhamad Aizat Kamaruddin ◽  
Ayham Ashqar ◽  
Muhammad Haniff Suhaimi ◽  
Fairus Azwardy Salleh

Abstract Uncertainties in fluid typing and contacts within Sarawak Offshore brown field required a real time decision. To enhance reservoir fluid characterisation and confirm reservoir connectivity prior to well final total depth (TD). Fluid typing while drilling was selected to assure the completion strategy and ascertain the fluvial reservoir petrophysical interpretation. Benefiting from low invasion, Logging While Drilling (LWD) sampling fitted with state of ART advanced spectroscopy sensors were deployed. Pressures and samples were collected. The well was drilled using synthetic base mud. Conventional logging while drilling tool string in addition to sampling tool that is equipped with advanced sensor technology were deployed. While drilling real time formation evaluation allowed selecting the zones of interest, while fluid typing was confirmed using continually monitored fluids pump out via multiple advanced sensors, contamination, and reservoir fluid properties were assessed while pumping. Pressure and sampling were performed in drilling mode to minimise reservoir damage, and optimise rig time, additionally sampling while drilling was performed under circulation conditions. Pressures were collected first followed by sampling. High success in collecting pressure points with a reliable fluid gradient that indicated a virgin reservoir allowed the selection of best completion strategy without jeopardising reserves, and reduced rig time. Total of seven samples from 3 different reservoirs, four oil, and three formation water. High quality samples were collected. The dynamic formation evaluation supported by while drilling sampling confirmed the reservoir fluid type and successfully discovered 39ft of oil net pay. Reservoir was completed as an oil producer. The Optical spectroscopy measurements allowed in situ fluid typing for the quick decision making. The use of advanced optical sensors allowed the sample collection and gave initial assessment on reservoir fluids properties, as a result cost saving due to eliminating the need for additional Drill Stem Test (DST) run to confirm the fluid type. Sample and formation pressures has confirmed reservoir lateral continuity in the vicinity of the field. The reservoir developed as thick and blocky sandstone. Collected sample confirmed the low contamination levels. Continuous circulation mitigated sticking and potential well-control risks. This is the first time in surrounding area, advanced optical sensors are used to aid LWD sampling and to finalize the fluid identification. The innovative technology allowed the collection of low contamination. The real-time in-situ fluid analysis measurement allowed critical decisions to be made real time, consequently reducing rig downtime. Reliable analysis of fluid type identification removed the need for additional run/service like DST etc.


Author(s):  
Sebastian Jessberger ◽  
Armin Curt ◽  
Roger A. Barker

A number of diseases of the brain and spinal cord are associated with substantial neural cell death and/or disruption of correct and functional neural networks. In the past, a variety of therapeutic strategies to rescue these systems have been proposed along with agents to induce functional plasticity within the remaining central nervous system (CNS) structures. In the case of injury or neurodegenerative disease these approaches have only met with limited success, indicating the need for novel approaches to treat diseases of the adult CNS. Recently, the idea of recruiting endogenous or transplanting stem cells to replace lost structures within the adult brain or spinal cord has gained significant attention, along with in situ reprogramming, and opened up novel therapeutic avenues in the context of regenerative medicine. Here we review recent advances in our understanding of how endogenous stem cells may be a part of pathological processes in certain neuropsychiatric diseases and summarize recent clinical and preclinical data suggesting that stem cell-based therapies hold great promise as a future treatment option in a number of diseases disrupting the proper function of the adult CNS.


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