Microfluidics for cell-based high throughput screening platforms - A review.

PubMed

Du, Guansheng; Fang, Qun; den Toonder, Jaap M J

2016-01-15

In the last decades, the basic techniques of microfluidics for the study of cells such as cell culture, cell separation, and cell lysis, have been well developed. Based on cell handling techniques, microfluidics has been widely applied in the field of PCR (Polymerase Chain Reaction), immunoassays, organ-on-chip, stem cell research, and analysis and identification of circulating tumor cells. As a major step in drug discovery, high-throughput screening allows rapid analysis of thousands of chemical, biochemical, genetic or pharmacological tests in parallel. In this review, we summarize the application of microfluidics in cell-based high throughput screening. The screening methods mentioned in this paper include approaches using the perfusion flow mode, the droplet mode, and the microarray mode. We also discuss the future development of microfluidic based high throughput screening platform for drug discovery. Copyright © 2015 Elsevier B.V. All rights reserved.

Three-dimensional radar imaging techniques and systems for near-field applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheen, David M.; Hall, Thomas E.; McMakin, Douglas L.

2016-05-12

The Pacific Northwest National Laboratory has developed three-dimensional holographic (synthetic aperture) radar imaging techniques and systems for a wide variety of near-field applications. These applications include radar cross-section (RCS) imaging, personnel screening, standoff concealed weapon detection, concealed threat detection, through-barrier imaging, ground penetrating radar (GPR), and non-destructive evaluation (NDE). Sequentially-switched linear arrays are used for many of these systems to enable high-speed data acquisition and 3-D imaging. In this paper, the techniques and systems will be described along with imaging results that demonstrate the utility of near-field 3-D radar imaging for these compelling applications.

Virtual Screening of Receptor Sites for Molecularly Imprinted Polymers.

PubMed

Bates, Ferdia; Cela-Pérez, María Concepción; Karim, Kal; Piletsky, Sergey; López-Vilariño, José Manuel

2016-08-01

Molecularly Imprinted Polymers (MIPs) are highly advantageous in the field of analytical chemistry. However, interference from secondary molecules can also impede capture of a target by a MIP receptor. This greatly complicates the design process and often requires extensive laboratory screening which is time consuming, costly, and creates substantial waste products. Herein, is presented a new technique for screening of "virtually imprinted receptors" for rebinding of the molecular template as well as secondary structures, correlating the virtual predictions with experimentally acquired data in three case studies. This novel technique is particularly applicable to the evaluation and prediction of MIP receptor specificity and efficiency in complex aqueous systems. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Composition of a Vision Screen for Servicemembers With Traumatic Brain Injury: Consensus Using a Modified Nominal Group Technique

PubMed Central

Finkelstein, Marsha; Llanos, Imelda; Scheiman, Mitchell; Wagener, Sharon Gowdy

2014-01-01

Vision impairment is common in the first year after traumatic brain injury (TBI), including among service members whose brain injuries occurred during deployment in Iraq and Afghanistan. Occupational therapy practitioners provide routine vision screening to inform treatment planning and referral to vision specialists, but existing methods are lacking because many tests were developed for children and do not screen for vision dysfunction typical of TBI. An expert panel was charged with specifying the composition of a vision screening protocol for servicemembers with TBI. A modified nominal group technique fostered discussion and objective determinations of consensus. After considering 29 vision tests, the panel recommended a nine-test vision screening that examines functional performance, self-reported problems, far–near acuity, reading, accommodation, convergence, eye alignment and binocular vision, saccades, pursuits, and visual fields. Research is needed to develop reliable, valid, and clinically feasible vision screening protocols to identify TBI-related vision disorders in adults. PMID:25005505

The impact of digital imaging in the field of cytopathology.

PubMed

Pantanowitz, Liron; Hornish, Maryanne; Goulart, Robert A

2009-03-06

With the introduction of digital imaging, pathology is undergoing a digital transformation. In the field of cytology, digital images are being used for telecytology, automated screening of Pap test slides, training and education (e.g. online digital atlases), and proficiency testing. To date, there has been no systematic review on the impact of digital imaging on the practice of cytopathology. This article critically addresses the emerging role of computer-assisted screening and the application of digital imaging to the field of cytology, including telecytology, virtual microscopy, and the impact of online cytology resources. The role of novel diagnostic techniques like image cytometry is also reviewed.

Improved self-reliance shearing interferometric technique for collimation testing

NASA Astrophysics Data System (ADS)

Zhao, Mingshan; Li, Guohua; Wang, Zhaobing; Jing, Yaling; Li, Yi

1995-06-01

Self-reference single plate shearing interferometric technique used for collimation testing of light beams are briefly reviewed. Two improved configurations of this self-reference interferometry with an inclined screen and matched half-field interferograms are described in detail. Sensitivity of these configurations is analyzed and compared with that of the existing ones.

Advances in fragment-based drug discovery platforms.

PubMed

Orita, Masaya; Warizaya, Masaichi; Amano, Yasushi; Ohno, Kazuki; Niimi, Tatsuya

2009-11-01

Fragment-based drug discovery (FBDD) has been established as a powerful alternative and complement to traditional high-throughput screening techniques for identifying drug leads. At present, this technique is widely used among academic groups as well as small biotech and large pharmaceutical companies. In recent years, > 10 new compounds developed with FBDD have entered clinical development, and more and more attention in the drug discovery field is being focused on this technique. Under the FBDD approach, a fragment library of relatively small compounds (molecular mass = 100 - 300 Da) is screened by various methods and the identified fragment hits which normally weakly bind to the target are used as starting points to generate more potent drug leads. Because FBDD is still a relatively new drug discovery technology, further developments and optimizations in screening platforms and fragment exploitation can be expected. This review summarizes recent advances in FBDD platforms and discusses the factors important for the successful application of this technique. Under the FBDD approach, both identifying the starting fragment hit to be developed and generating the drug lead from that starting fragment hit are important. Integration of various techniques, such as computational technology, X-ray crystallography, NMR, surface plasmon resonance, isothermal titration calorimetry, mass spectrometry and high-concentration screening, must be applied in a situation-appropriate manner.

Site characterization design and techniques used at the Southern Shipbuilding Corporation site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, J.P.; Geraghty, C.A.; Moore, G.W.

1995-12-31

The Southern Shipbuilding Corporation (SSC) site is an inactive barge/ship manufacturing and repair facility situated on approximately 54 acres in Slidell, St. Tammany Parish, Louisiana. Two unlined surface impoundments (North and South impoundments) are situated on the northwest portion of the site and are surrounded on three sides by Bayou Bonfouca. These impoundments are the sources of carcinogenic polynuclear aromatic hydrocarbon (CPAH) contamination at the site. Inadequate containment has resulted in the release of impoundment wastes into the bayou. To evaluate potential response alternatives for the site, an Engineering Evaluation/Cost Analysis (EE/CA) field investigation was conducted from July through Octobermore » 1994. A two phase sampling approach was used in combination with innovative and traditional sampling techniques, field screening technologies, and exploitation of the visual characteristics of the waste to determine the extent of waste migration with limited off-site laboratory confirmation. A skid-mounted mobile drilling unit, secured to a specialized sampling platform designed for multiple applications, was used for collection of sediment cores from the bayou as well as tarry sludge cores from the impoundments. Field screening of core samples was accomplished on site using an organic vapor analyzer and a total petroleum hydrocarbon (TPH) field analyzer. Pollutants of concern include metals, cyanide, dioxin, and organic compounds. This paper presents details on the sampling design and characterization techniques used to accomplish the EE/CA field investigation.« less

Lessons from high-throughput protein crystallization screening: 10 years of practical experience

PubMed Central

JR, Luft; EH, Snell; GT, DeTitta

2011-01-01

Introduction X-ray crystallography provides the majority of our structural biological knowledge at a molecular level and in terms of pharmaceutical design is a valuable tool to accelerate discovery. It is the premier technique in the field, but its usefulness is significantly limited by the need to grow well-diffracting crystals. It is for this reason that high-throughput crystallization has become a key technology that has matured over the past 10 years through the field of structural genomics. Areas covered The authors describe their experiences in high-throughput crystallization screening in the context of structural genomics and the general biomedical community. They focus on the lessons learnt from the operation of a high-throughput crystallization screening laboratory, which to date has screened over 12,500 biological macromolecules. They also describe the approaches taken to maximize the success while minimizing the effort. Through this, the authors hope that the reader will gain an insight into the efficient design of a laboratory and protocols to accomplish high-throughput crystallization on a single-, multiuser-laboratory or industrial scale. Expert Opinion High-throughput crystallization screening is readily available but, despite the power of the crystallographic technique, getting crystals is still not a solved problem. High-throughput approaches can help when used skillfully; however, they still require human input in the detailed analysis and interpretation of results to be more successful. PMID:22646073

A 360-degree floating 3D display based on light field regeneration.

PubMed

Xia, Xinxing; Liu, Xu; Li, Haifeng; Zheng, Zhenrong; Wang, Han; Peng, Yifan; Shen, Weidong

2013-05-06

Using light field reconstruction technique, we can display a floating 3D scene in the air, which is 360-degree surrounding viewable with correct occlusion effect. A high-frame-rate color projector and flat light field scanning screen are used in the system to create the light field of real 3D scene in the air above the spinning screen. The principle and display performance of this approach are investigated in this paper. The image synthesis method for all the surrounding viewpoints is analyzed, and the 3D spatial resolution and angular resolution of the common display zone are employed to evaluate display performance. The prototype is achieved and the real 3D color animation image has been presented vividly. The experimental results verified the representability of this method.

Radon assay and purification techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simgen, Hardy

Radon is a source of background in many astroparticle physics experiments searching for rare low energy events. In this paper an overview about radon in the field is given including radon detection techniques, radon sources and material screening with respect to radon emanation. Finally, also the problem of long-lived radioactive {sup 222}Rn-daughters and the question of gas purification from radon is addressed.

Radon assay and purification techniques

NASA Astrophysics Data System (ADS)

Simgen, Hardy

2013-08-01

Radon is a source of background in many astroparticle physics experiments searching for rare low energy events. In this paper an overview about radon in the field is given including radon detection techniques, radon sources and material screening with respect to radon emanation. Finally, also the problem of long-lived radioactive 222Rn-daughters and the question of gas purification from radon is addressed.

Virtual Screening with AutoDock: Theory and Practice

PubMed Central

Cosconati, Sandro; Forli, Stefano; Perryman, Alex L.; Harris, Rodney; Goodsell, David S.; Olson, Arthur J.

2011-01-01

Importance to the field Virtual screening is a computer-based technique for identifying promising compounds to bind to a target molecule of known structure. Given the rapidly increasing number of protein and nucleic acid structures, virtual screening continues to grow as an effective method for the discovery of new inhibitors and drug molecules. Areas covered in this review We describe virtual screening methods that are available in the AutoDock suite of programs, and several of our successes in using AutoDock virtual screening in pharmaceutical lead discovery. What the reader will gain A general overview of the challenges of virtual screening is presented, along with the tools available in the AutoDock suite of programs for addressing these challenges. Take home message Virtual screening is an effective tool for the discovery of compounds for use as leads in drug discovery, and the free, open source program AutoDock is an effective tool for virtual screening. PMID:21532931

Frontiers in Chemical Sensors: Novel Principles and Techniques

NASA Astrophysics Data System (ADS)

Orellana, Guillermo; Moreno-Bondi, Maria Cruz

This third volume of Springer Series on Chemical Sensors and Biosensors aims to enable the researcher or technologist to become acquainted with the latest principles and techniques that keep on enlarging the applications in this fascinating field. It deals with the novel luminescence lifetime-based techniques for interrogation of sensor arrays in high-throughput screening, cataluminescence, chemical sensing with hollow waveguides, new ways in sensor design and fabrication by means of either combinatorial methods or engineered indicator/support couples.

Magnetic Frequency Response of HL-LHC Beam Screens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrone, M.; Martino, M.; De Maria, R.

Magnetic fields used to control particle beams in accelerators are usually controlled by regulating the electrical current of the power converters. In order to minimize lifetime degradation and ultimately luminosity loss in circular colliders, current-noise is a highly critical figure of merit of power converters, in particular for magnets located in areas with high beta-function, like the High Luminosity Large Hadron Collider (HL-LHC) insertions. However, what is directly acting upon the beam is the magnetic field and not the current of the power converter, which undergoes several frequency-dependent transformations until the desired magnetic field, seen by the beam, is obtained.more » Beam screens are very rarely considered when assessing or specifying the noise figure of merit, but their magnetic frequency response is such that they realize relatively effective low pass filtering of the magnetic field produced by the system magnet-power converter. This work aims at filling this gap by quantifying the expected impact of different beam screen layouts for the most relevant HL-LHC insertion magnets. A welldefined post-processing technique is used to derive the frequency response of the different multipoles from multi-physics Finite Element Method (FEM) simulation results. In addition, a well approximated analytical formula for the low-frequency range of multi-layered beam screens is presented.« less

Determination of depth-viewing volumes for stereo three-dimensional graphic displays

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Williams, Steven P.

1990-01-01

Real-world, 3-D, pictorial displays incorporating true depth cues via stereopsis techniques offer a potential means of displaying complex information in a natural way to prevent loss of situational awareness and provide increases in pilot/vehicle performance in advanced flight display concepts. Optimal use of stereopsis requires an understanding of the depth viewing volume available to the display designer. Suggested guidelines are presented for the depth viewing volume from an empirical determination of the effective region of stereopsis cueing (at several viewer-CRT screen distances) for a time multiplexed stereopsis display system. The results provide the display designer with information that will allow more effective placement of depth information to enable the full exploitation of stereopsis cueing. Increasing viewer-CRT screen distances provides increasing amounts of usable depth, but with decreasing fields-of-view. A stereopsis hardware system that permits an increased viewer-screen distance by incorporating larger screen sizes or collimation optics to maintain the field-of-view at required levels would provide a much larger stereo depth-viewing volume.

Study of electronic structure of liquid Pb

NASA Astrophysics Data System (ADS)

Vora, A. M.; Gajjar, P. N.

2018-04-01

The Fiolhais et al.'s universal model potential in conjunction with the hard sphere technique of Percus and Yevick has been used for the study of electronic structure, Fermi energy and density of states of liquid Pb. The screening influence of the different forms of the local field correction functions proposed by Hartree (H) and Taylor (T) on the afore said properties is studied, which replicates the changing effects of screening and found suitable for the present study.

Computer-aided screening system for cervical precancerous cells based on field emission scanning electron microscopy and energy dispersive x-ray images and spectra

NASA Astrophysics Data System (ADS)

Jusman, Yessi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Kurnia, Rahmadi; Osman, Noor Azuan Bin Abu; Teoh, Kean Hooi

2016-10-01

The capability of field emission scanning electron microscopy and energy dispersive x-ray spectroscopy (FE-SEM/EDX) to scan material structures at the microlevel and characterize the material with its elemental properties has inspired this research, which has developed an FE-SEM/EDX-based cervical cancer screening system. The developed computer-aided screening system consisted of two parts, which were the automatic features of extraction and classification. For the automatic features extraction algorithm, the image and spectra of cervical cells features extraction algorithm for extracting the discriminant features of FE-SEM/EDX data was introduced. The system automatically extracted two types of features based on FE-SEM/EDX images and FE-SEM/EDX spectra. Textural features were extracted from the FE-SEM/EDX image using a gray level co-occurrence matrix technique, while the FE-SEM/EDX spectra features were calculated based on peak heights and corrected area under the peaks using an algorithm. A discriminant analysis technique was employed to predict the cervical precancerous stage into three classes: normal, low-grade intraepithelial squamous lesion (LSIL), and high-grade intraepithelial squamous lesion (HSIL). The capability of the developed screening system was tested using 700 FE-SEM/EDX spectra (300 normal, 200 LSIL, and 200 HSIL cases). The accuracy, sensitivity, and specificity performances were 98.2%, 99.0%, and 98.0%, respectively.

Nanoparticle-density-dependent field emission of surface-decorated SiC nanowires

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Qizheng; School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo City 315016; State Key Lab of New Fine Ceramics and Fine Processing, Tsinghua University, Beijing City 100084

2016-08-22

Increasing the electron emission site density of nanostructured emitters with limited field screening effects is one of the key issues for improving the field emission (FE) properties. In this work, we reported the Au-nanoparticles-density-dependent field emission behaviors of surface-decorated SiC nanowires. The Au nanoparticles (AuNPs) decorated around the surface of the SiC nanowires were achieved via an ion sputtering technique, by which the densities of the isolated AuNPs could be adjusted by controlling the fixed sputtering times. The measured FE characteristics demonstrated that the turn-on fields of the SiC nanowires were tuned to be of 2.06, 1.14, and 3.35 V/μm withmore » the increase of the decorated AuNPs densities, suggesting that a suitable decorated AuNPs density could render the SiC nanowires with totally excellent FE performances by increasing the emission sites and limiting the field screening effects.« less

Contrast-enhanced Spectral Mammography: Technique, Indications, and Clinical Applications.

PubMed

Bhimani, Chandni; Matta, Danielle; Roth, Robyn G; Liao, Lydia; Tinney, Elizabeth; Brill, Kristin; Germaine, Pauline

2017-01-01

Contrast-enhanced spectral mammography (CESM) combines the benefits of full field digital mammography with the concept of tumor angiogenesis. Technique and practical applications of CESM are discussed. An overview of the technique is followed by a demonstration of practical applications of CESM in our practice. We have successfully implemented CESM into our practice as a screening, diagnostic, staging, and treatment response tool. It is important to understand the technique of CESM and how to incorporate it into practice. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Screening and selection of most potent diazotrophic cyanobacterial isolate exhibiting natural tolerance to rice field herbicides for exploitation as biofertilizer.

PubMed

Singh, Surendra; Datta, Pallavi

2006-01-01

Periodic applications of heavy dosages of herbicides in modern rice-agriculture are a necessary evil for obtaining high crop productivity. Such herbicides are not only detrimental to weeds but biofertilizer strains of diazotrophic cyanobacteria also. It is therefore, essential to screen and select such biofertilizer strains of diazotrophic cyanobacteria exhibiting natural tolerance to common rice-field herbicides that can be further improved by mutational techniques to make biofertilizer technology a viable one. Therefore, efforts have been made to screen five dominant diazotrophic cyanobacterial forms e.g. filamentous heterocystous Nostoc punctiforme , Nostoc calcicola , Anabaena variabilis and unicellular Gloeocapsa sp. and Aphanocapsa sp. along with standard laboratory strain Nostoc muscorum ISU against increasing concentrations (0-100 mg l(-1) of four commercial grade common rice-field herbicides i.e. Arozin, Butachlor, Alachlor and 2,4-D under diazotrophic growth conditions. The lethal and IGC(50) concentrations for all four herbicides tested were found highest for A. variabilis as compared to other test cyanobacteria. The lowest reduction in chlorophyll a content, photosynthetic oxygen evolution, and N(2)-fixation was found in A. variabilis as compared to other rice field isolates and standard laboratory strain N. muscorum ISU. On the basis of prolong survival potential and lowest reductions in vital metabolic activities tested at IGC(50) concentration of four herbicides, it is concluded that A. variabilis is the most potent and promising cyanobacterial isolate as compared with other forms. This could be further improved by mutational techniques for exploitation as most potential and viable biofertilizer strain.

Hyperspectral fluorescence imaging coupled with multivariate image analysis techniques for contaminant screening of leafy greens

NASA Astrophysics Data System (ADS)

Everard, Colm D.; Kim, Moon S.; Lee, Hoyoung

2014-05-01

The production of contaminant free fresh fruit and vegetables is needed to reduce foodborne illnesses and related costs. Leafy greens grown in the field can be susceptible to fecal matter contamination from uncontrolled livestock and wild animals entering the field. Pathogenic bacteria can be transferred via fecal matter and several outbreaks of E.coli O157:H7 have been associated with the consumption of leafy greens. This study examines the use of hyperspectral fluorescence imaging coupled with multivariate image analysis to detect fecal contamination on Spinach leaves (Spinacia oleracea). Hyperspectral fluorescence images from 464 to 800 nm were captured; ultraviolet excitation was supplied by two LED-based line light sources at 370 nm. Key wavelengths and algorithms useful for a contaminant screening optical imaging device were identified and developed, respectively. A non-invasive screening device has the potential to reduce the harmful consequences of foodborne illnesses.

An update in breast cancer screening and management.

PubMed

Warrier, Sanjay; Tapia, Grace; Goltsman, David; Beith, Jane

2016-01-01

This article provides an overview of the main controversies in a number of key areas of breast cancer management. Relevant studies that have contributed to guide the treatment of this heterogeneous disease in the field of breast screening, surgery, chemotherapy and radiotherapy are highlighted. Mammography and ultrasound are the main methods of breast screening. MRI and tomosynthesis are emerging as new screening tools for a selected group of breast cancer patients. From a surgical perspective, oncoplastic techniques and neoadjuvant chemotherapy are improving cosmetic results in breast-conserving surgery. For high-risk patients, controversies still remain regarding prophylactic mastectomies. Finally, the appropriate management of the axilla continues evolving with the increasing role of radiotherapy as an alternative treatment to axillary dissection.

An Update in Breast Cancer Screening and Management

PubMed Central

Warrier, Sanjay; Tapia, Grace; Goltsman, David; Beith, Jane

2015-01-01

This article provides an overview of the main controversies in a number of key areas of breast cancer management. Relevant studies that have contributed to guide the treatment of this heterogeneous disease in the field of breast screening, surgery, chemotherapy and radiotherapy are highlighted. Mammography and ultrasound are the main methods of breast screening. MRI and tomosynthesis are emerging as new screening tools for a selected group of breast cancer patients. From a surgical perspective, oncoplastic techniques and neoadjuvant chemotherapy are improving cosmetic results in breast-conserving surgery. For high-risk patients, controversies still remain regarding prophylactic mastectomies. Finally, the appropriate management of the axilla continues evolving with the increasing role of radiotherapy as an alternative treatment to axillary dissection. PMID:26689336

Cell manipulation in microfluidics.

PubMed

Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

2013-06-01

Recent advances in the lab-on-a-chip field in association with nano/microfluidics have been made for new applications and functionalities to the fields of molecular biology, genetic analysis and proteomics, enabling the expansion of the cell biology field. Specifically, microfluidics has provided promising tools for enhancing cell biological research, since it has the ability to precisely control the cellular environment, to easily mimic heterogeneous cellular environment by multiplexing, and to analyze sub-cellular information by high-contents screening assays at the single-cell level. Various cell manipulation techniques in microfluidics have been developed in accordance with specific objectives and applications. In this review, we examine the latest achievements of cell manipulation techniques in microfluidics by categorizing externally applied forces for manipulation: (i) optical, (ii) magnetic, (iii) electrical, (iv) mechanical and (v) other manipulations. We furthermore focus on history where the manipulation techniques originate and also discuss future perspectives with key examples where available.

Progress of new label-free techniques for biosensors: a review.

PubMed

Sang, Shengbo; Wang, Yajun; Feng, Qiliang; Wei, Ye; Ji, Jianlong; Zhang, Wendong

2016-01-01

The detection techniques used in biosensors can be broadly classified into label-based and label-free. Label-based detection relies on the specific properties of labels for detecting a particular target. In contrast, label-free detection is suitable for the target molecules that are not labeled or the screening of analytes which are not easy to tag. Also, more types of label-free biosensors have emerged with developments in biotechnology. The latest developed techniques in label-free biosensors, such as field-effect transistors-based biosensors including carbon nanotube field-effect transistor biosensors, graphene field-effect transistor biosensors and silicon nanowire field-effect transistor biosensors, magnetoelastic biosensors, optical-based biosensors, surface stress-based biosensors and other type of biosensors based on the nanotechnology are discussed. The sensing principles, configurations, sensing performance, applications, advantages and restriction of different label-free based biosensors are considered and discussed in this review. Most concepts included in this survey could certainly be applied to the development of this kind of biosensor in the future.

Unified Application of Vapor Screen Flow Visualization and Pressure Sensitive Paint Measurement Techniques to Vortex- and Shock Wave-Dominated Flow Fields

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2010-01-01

Laser vapor screen (LVS) flow visualization and pressure sensitive paint (PSP) techniques were applied in a unified approach to wind tunnel testing of slender wing and missile configurations dominated by vortex flows and shock waves at subsonic, transonic, and supersonic speeds. The off-surface cross-flow patterns using the LVS technique were combined with global PSP surface static pressure mappings to characterize the leading-edge vortices and shock waves that coexist and interact at high angles of attack. The synthesis of LVS and PSP techniques was also effective in identifying the significant effects of passive surface porosity and the presence of vertical tail surfaces on the flow topologies. An overview is given of LVS and PSP applications in selected experiments on small-scale models of generic slender wing and missile configurations in the NASA Langley Research Center (NASA LaRC) Unitary Plan Wind Tunnel (UPWT) and 8-Foot Transonic Pressure Tunnel (8-Foot TPT).

Unified Application Vapor Screen Flow Visualization and Pressure Sensitive Paint Measurement Techniques to Vortex- and Shock Wave-Dominated Flow Fields

NASA Technical Reports Server (NTRS)

Erickson, Gary E.

2008-01-01

Laser vapor screen (LVS) flow visualization and pressure sensitive paint (PSP) techniques were applied in a unified approach to wind tunnel testing of slender wing and missile configurations dominated by vortex flows and shock waves at subsonic, transonic, and supersonic speeds. The off-surface cross-flow patterns using the LVS technique were combined with global PSP surface static pressure mappings to characterize the leading-edge vortices and shock waves that coexist and interact at high angles of attack (alpha). The synthesis of LVS and PSP techniques was also effective in identifying the significant effects of passive surface porosity and the presence of vertical tail surfaces on the flow topologies. An overview is given of LVS and PSP applications in selected experiments on small-scale models of generic slender wing and missile configurations in the NASA Langley Research Center (NASA LaRC) Unitary Plan Wind Tunnel (UPWT) and 8-Foot Transonic Pressure Tunnel (8-Foot TPT).

Forensic electrochemistry: indirect electrochemical sensing of the components of the new psychoactive substance "Synthacaine".

PubMed

Cumba, Loanda R; Kolliopoulos, Athanasios V; Smith, Jamie P; Thompson, Paul D; Evans, Peter R; Sutcliffe, Oliver B; do Carmo, Devaney R; Banks, Craig E

2015-08-21

"Synthacaine" is a New Psychoactive Substance which is, due to its inherent psychoactive properties, reported to imitate the effects of cocaine and is therefore consequently branded as "legal cocaine". The only analytical approach reported to date for the sensing of "Synthacaine" is mass spectrometry. In this paper, we explore and evaluate a range of potential analytical techniques for its quantification and potential use in the field screening "Synthacaine" using Raman spectroscopy, presumptive (colour) testing, High Performance Liquid Chromatography (HPLC) and electrochemistry. HPLC analysis of street samples reveals that "Synthacaine" comprises a mixture of methiopropamine (MPA) and 2-aminoindane (2-AI). Raman spectroscopy and presumptive (colour) tests, the Marquis, Mandelin, Simon's and Robadope test, are evaluated towards a potential in-the-field screening approach but are found to not be able to discriminate between the two when they are both present in the same sample, as is the case in the real street samples. We report for the first time a novel indirect electrochemical protocol for the sensing of MPA and 2-AI which is independently validated in street samples with HPLC. This novel electrochemical approach based upon one-shot disposable cost effective screen-printed graphite macroelectrodes holds potential for in-the-field screening for "Synthacaine".

Water tunnel flow visualization using a laser

NASA Technical Reports Server (NTRS)

Beckner, C.; Curry, R. E.

1985-01-01

Laser systems for flow visualization in water tunnels (similar to the vapor screen technique used in wind tunnels) can provide two-dimensional cross-sectional views of complex flow fields. This parametric study documents the practical application of the laser-enhanced visualization (LEV) technique to water tunnel testing. Aspects of the study include laser power levels, flow seeding (using flourescent dyes and embedded particulates), model preparation, and photographic techniques. The results of this study are discussed to provide potential users with basic information to aid in the design and setup of an LEV system.

Targeted Provision of Oral Iron: The Evolution of a Practical Screening Option123

PubMed Central

Crowley, Caitlin R.; Solomons, Noel W.; Schümann, Klaus

2012-01-01

Universal oral iron supplementation, undertaken according to 1998 WHO guidelines, produced adverse consequences among some children in malaria-endemic areas. Prompted by the Pemba trial, which revealed excessive hospitalizations and deaths, WHO advised that iron supplementation in such regions be accompanied by previous screening for iron deficiency. This agenda, however, poses issues of cost, benefit, acceptability, technical feasibility, and reliability of such screening. The cost of equipment and personnel is balanced against savings from iron supplements spared and treatment for morbidity averted. Costs aside, the most efficacious acceptable screening approach for avoiding hospitalization and deaths must be fielded. Screening before supplementation can be used to assess hematological, iron, and possible inflammatory status to differentiate the source of decreased hemoglobin concentration. Iron deficiency has often been inferred from hematological status markers. The need for extraction of blood, albeit capillary in origin, and high assay costs limit the use of validated methods in screening. Noninvasive methods, i.e., not requiring the extraction of blood, provide the most acceptable and potentially least expensive approach for determining hematological or iron status. Although a noninvasive technique for iron and inflammatory status would be the ideal, it is unattained. Field-friendly, skin-probe hemoglobin devices, derived from instruments for clinical settings, are being developed and tested for eventual rollout in malarial areas. Given a firm grounding for the theoretical requirements needed to advance the screening agenda, evaluation and monitoring of the performance of screening devices can proceed hand in hand. PMID:22797993

Disposable Screen Printed Electrochemical Sensors: Tools for Environmental Monitoring

PubMed Central

Hayat, Akhtar; Marty, Jean Louis

2014-01-01

Screen printing technology is a widely used technique for the fabrication of electrochemical sensors. This methodology is likely to underpin the progressive drive towards miniaturized, sensitive and portable devices, and has already established its route from “lab-to-market” for a plethora of sensors. The application of these sensors for analysis of environmental samples has been the major focus of research in this field. As a consequence, this work will focus on recent important advances in the design and fabrication of disposable screen printed sensors for the electrochemical detection of environmental contaminants. Special emphasis is given on sensor fabrication methodology, operating details and performance characteristics for environmental applications. PMID:24932865

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alekseev, I. S.; Ivanov, I. E.; Strelkov, P. S., E-mail: strelkov@fpl.gpi.ru

A method based on the detection of emission of a dielectric screen with metal microinclusions in open air is applied to visualize the transverse structure of a high-power microwave beam. In contrast to other visualization techniques, the results obtained in this work provide qualitative information not only on the electric field strength, but also on the structure of electric field lines in the microwave beam cross section. The interpretation of the results obtained with this method is confirmed by numerical simulations of the structure of electric field lines in the microwave beam cross section by means of the CARAT code.

Investigation of radio astronomy image processing techniques for use in the passive millimetre-wave security screening environment

NASA Astrophysics Data System (ADS)

Taylor, Christopher T.; Hutchinson, Simon; Salmon, Neil A.; Wilkinson, Peter N.; Cameron, Colin D.

2014-06-01

Image processing techniques can be used to improve the cost-effectiveness of future interferometric Passive MilliMetre Wave (PMMW) imagers. The implementation of such techniques will allow for a reduction in the number of collecting elements whilst ensuring adequate image fidelity is maintained. Various techniques have been developed by the radio astronomy community to enhance the imaging capability of sparse interferometric arrays. The most prominent are Multi- Frequency Synthesis (MFS) and non-linear deconvolution algorithms, such as the Maximum Entropy Method (MEM) and variations of the CLEAN algorithm. This investigation focuses on the implementation of these methods in the defacto standard for radio astronomy image processing, the Common Astronomy Software Applications (CASA) package, building upon the discussion presented in Taylor et al., SPIE 8362-0F. We describe the image conversion process into a CASA suitable format, followed by a series of simulations that exploit the highlighted deconvolution and MFS algorithms assuming far-field imagery. The primary target application used for this investigation is an outdoor security scanner for soft-sided Heavy Goods Vehicles. A quantitative analysis of the effectiveness of the aforementioned image processing techniques is presented, with thoughts on the potential cost-savings such an approach could yield. Consideration is also given to how the implementation of these techniques in CASA might be adapted to operate in a near-field target environment. This may enable a much wider usability by the imaging community outside of radio astronomy and thus would be directly relevant to portal screening security systems in the microwave and millimetre wave bands.

Poor Man's Virtual Camera: Real-Time Simultaneous Matting and Camera Pose Estimation.

PubMed

Szentandrasi, Istvan; Dubska, Marketa; Zacharias, Michal; Herout, Adam

2016-03-18

Today's film and advertisement production heavily uses computer graphics combined with living actors by chromakeying. The matchmoving process typically takes a considerable manual effort. Semi-automatic matchmoving tools exist as well, but they still work offline and require manual check-up and correction. In this article, we propose an instant matchmoving solution for green screen. It uses a recent technique of planar uniform marker fields. Our technique can be used in indie and professional filmmaking as a cheap and ultramobile virtual camera, and for shot prototyping and storyboard creation. The matchmoving technique based on marker fields of shades of green is very computationally efficient: we developed and present in the article a mobile application running at 33 FPS. Our technique is thus available to anyone with a smartphone at low cost and with easy setup, opening space for new levels of filmmakers' creative expression.

Analyzing slug tests in wells screened across the watertable: A field assessment

USGS Publications Warehouse

Stanford, K.L.; McElwee, C.D.

2000-01-01

The slug test is the most widely used technique for the in situ estimation of hydraulic conductivity in confined and unconfined formations. Currently, there are no generally accepted methods in the groundwater literature for the analysis of response data from slug tests performed in wells screened across the watertable. A field study was undertaken in an attempt to develop a set of practical guidelines for tests conducted in such wells. Three wells, screened within unconsolidated material exhibiting a range of hydraulic conductivities (.05-30.0 m/day), were installed to depths of up to 9 m (30 ft) in Kansas River alluvium that ranges in thickness from 15 m to 21 m (50 ft to 70 ft) near Lawrence, Kansas. Intensive well-development efforts removed any drilling debris that could interfere with well-formation hydraulics. Once the wells were developed properly, a series of slug tests was performed at each well. The tests were designed to assess the role of the unsaturated zone and the appropriateness of assuming a fixed hydraulic head upper boundary. The results of this investigation can be summarized as follows: (1) the sufficiency of well development should be based on repeat slug tests and not the clarity of pumped water; (2) the effective screen radius for best model analysis should be based on a mass balance and not nominal screen dimensions; (3) the watertable can be represented as a constant head boundary and flow in the unsaturated zone can be ignored in most situations; (4) conventional techniques for the analysis of slug-test data seem to be reasonable for slug tests conducted in wells screened across the watertable, when used with the appropriate effective screen radius and normalized head range; and (5) fluctuations in the watertable elevation through time can be exploited to obtain some insight into the nature of vertical variation in hydraulic conductivity at a well. The results of this investigation indicate that multiple slug tests should be performed at wells screened across the watertable in order to reliably assess the sufficiency of well development and the appropriateness of conventional theory. ?? 2000 International Association for Mathematical Geology.

A novel x-ray imaging system and its imaging performance

NASA Astrophysics Data System (ADS)

Yu, Chunyu; Chang, Benkang; Wang, Shiyun; Zhang, Junju; Yao, Xiao

2006-09-01

Since x-ray was discovered and applied to the imaging technology, the x-ray imaging techniques have experienced several improvements, from film-screen, x-ray image intensifier, CR to DR. To store and transmit the image information conveniently, the digital imaging is necessary for the imaging techniques in medicine and biology. Usually as the intensifying screen technique as for concerned, to get the digital image signals, the CCD was lens coupled directly to the screen, but which suffers from a loss of x-ray signal and resulted in the poor x-ray image perfonnance. Therefore, to improve the image performance, we joined the brightness intensifier, which, was named the Low Light Level (LLL) image intensifier in military affairs, between the intensifying screen and the CCD and designed the novel x-ray imaging system. This design method improved the image performance of the whole system thus decreased the x-ray dose. Comparison between two systems with and without the brightness intensifier was given in detail in this paper. Moreover, the main noise source of the image produced by the novel system was analyzed, and in this paper, the original images produced by the novel x-ray imaging system and the processed images were given respectively. It was clear that the image performance was satisfied and the x-ray imaging system can be used in security checking and many other nondestructive checking fields.

Adaptive Gaussian mixture models for pre-screening in GPR data

NASA Astrophysics Data System (ADS)

Torrione, Peter; Morton, Kenneth, Jr.; Besaw, Lance E.

2011-06-01

Due to the large amount of data generated by vehicle-mounted ground penetrating radar (GPR) antennae arrays, advanced feature extraction and classification can only be performed on a small subset of data during real-time operation. As a result, most GPR based landmine detection systems implement "pre-screening" algorithms to processes all of the data generated by the antennae array and identify locations with anomalous signatures for more advanced processing. These pre-screening algorithms must be computationally efficient and obtain high probability of detection, but can permit a false alarm rate which might be higher than the total system requirements. Many approaches to prescreening have previously been proposed, including linear prediction coefficients, the LMS algorithm, and CFAR-based approaches. Similar pre-screening techniques have also been developed in the field of video processing to identify anomalous behavior or anomalous objects. One such algorithm, an online k-means approximation to an adaptive Gaussian mixture model (GMM), is particularly well-suited to application for pre-screening in GPR data due to its computational efficiency, non-linear nature, and relevance of the logic underlying the algorithm to GPR processing. In this work we explore the application of an adaptive GMM-based approach for anomaly detection from the video processing literature to pre-screening in GPR data. Results with the ARA Nemesis landmine detection system demonstrate significant pre-screening performance improvements compared to alternative approaches, and indicate that the proposed algorithm is a complimentary technique to existing methods.

Automatic 1H-NMR Screening of Fatty Acid Composition in Edible Oils

PubMed Central

Castejón, David; Fricke, Pascal; Cambero, María Isabel; Herrera, Antonio

2016-01-01

In this work, we introduce an NMR-based screening method for the fatty acid composition analysis of edible oils. We describe the evaluation and optimization needed for the automated analysis of vegetable oils by low-field NMR to obtain the fatty acid composition (FAC). To achieve this, two scripts, which automatically analyze and interpret the spectral data, were developed. The objective of this work was to drive forward the automated analysis of the FAC by NMR. Due to the fact that this protocol can be carried out at low field and that the complete process from sample preparation to printing the report only takes about 3 min, this approach is promising to become a fundamental technique for high-throughput screening. To demonstrate the applicability of this method, the fatty acid composition of extra virgin olive oils from various Spanish olive varieties (arbequina, cornicabra, hojiblanca, manzanilla, and picual) was determined by 1H-NMR spectroscopy according to this protocol. PMID:26891323

SUBSURFACE CHARACTERIZATION AND MONITORING TECHNIQUES: A DESK REFERENCE GUIDE - VOLUME II: THE VADOSE ZONE, FIELD SCREENING AND ANALYTICAL METHODS - APPENDICES C AND D

EPA Science Inventory

Many EPA programs, including those under the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Response, Compensation, and Liability Act (CERCLA), require subsurface characterization and monitoring to detect ground-water contamination and provide data to deve...

A Field-Shaking System to Reduce the Screening Current-Induced Field in the 800-MHz HTS Insert of the MIT 1.3-GHz LTS/HTS NMR Magnet: A Small-Model Study.

PubMed

Lee, Jiho; Park, Dongkeun; Michael, Philip C; Noguchi, So; Bascuñán, Juan; Iwasa, Yukikazu

2018-04-01

In this paper, we present experimental results, of a small-model study, from which we plan to develop and apply a full-scale field-shaking system to reduce the screening current-induced field (SCF) in the 800-MHz HTS Insert (H800) of the MIT 1.3-GHz LTS/HTS NMR magnet (1.3G) currently under construction-the H800 is composed of 3 nested coils, each a stack of no-insulation (NI) REBCO double-pancakes. In 1.3G, H800 is the chief source of a large error field generated by its own SCF. To study the effectiveness of the field-shaking technique, we used two NI REBCO double-pancakes, one from Coil 2 (HCoil2) and one from Coil 3 (HCoil3) of the 3 H800 coils, and placed them in the bore of a 5-T/300-mm room-temperature bore low-temperature superconducting (LTS) background magnet. The background magnet is used not only to induce the SCF in the double-pancakes but also to reduce it by the field-shaking technique. For each run, we induced the SCF in the double-pancakes at an axial location where the external radial field Br > 0, then for the field-shaking, moved them to another location where the external axial field Bz ≫ B R . Due to the geometry of H800 and L500, top double-pancakes of 3 H800 coils will experience the considerable radial magnetic field perpendicular to the REBCO tape surface. To examine the effect of the field-shaking on the SCF, we tested each NI REBCO DP in the absence or presence of a radial field. In this paper, we report 77-K experimental results and analysis of the effect and a few significant remarks of the field-shaking.

From a genetic innovation to mass health programmes: the diffusion of Down's Syndrome prenatal screening and diagnostic techniques in France.

PubMed

Vassy, Carine

2006-10-01

Down's Syndrome prenatal diagnostic and screening techniques have spread widely in France over the last 30 years and are now part of the routine clinical practice of prenatal care. These techniques, which originated in the field of genetics, ultrasonography and biochemistry, were the first to provide the possibility of choosing the features of the foetus, or at least to reject some of its characteristics. They lead to new norms of healthy foetuses and a progressive acceptance of medical abortions. The aim of this paper is to understand how the use of these tests has been generalised in France despite scientific controversies about their risks and ethical questioning about a potential renewal of eugenics. It analyses the representations of public needs that have been articulated by key players in the scientific and medical fields. This research explores political and administrative decision making processes to understand how progressively widening public access to prenatal testing has been organised and funded. The results highlight the scientific and political role of biomedical researchers, the forms of involvement of health authorities and politicians, and the passive participation of the vast majority of the users. The paper also examines the characteristics of the French health system that facilitated the generalised use of the technology.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurley, D.F.; Whitehouse, J.M.

A dedicated low-flow groundwater sample collection system was designed for implementation in a post-closure ACL monitoring program at the Yaworski Lagoon NPL site in Canterbury, Connecticut. The system includes dedicated bladder pumps with intake ports located in the screened interval of the monitoring wells. This sampling technique was implemented in the spring of 1993. The system was designed to simultaneously obtain samples directly from the screened interval of nested wells in three distinct water bearing zones. Sample collection is begun upon stabilization of field parameters. Other than line volume, no prior purging of the well is required. It was foundmore » that dedicated low-flow sampling from the screened interval provides a method of representative sample collection without the bias of suspended solids introduced by traditional techniques of pumping and bailing. Analytical data indicate that measured chemical constituents are representative of groundwater migrating through the screened interval. Upon implementation of the low-flow monitoring system, analytical results exhibited a decrease in concentrations of some organic compounds and metals. The system has also proven to be a cost effective alternative to pumping and bailing which generate large volumes of purge water requiring containment and disposal.« less

A methodological overview on molecular preimplantation genetic diagnosis and screening: a genomic future?

PubMed

Vendrell, Xavier; Bautista-Llácer, Rosa

2012-12-01

The genetic diagnosis and screening of preimplantation embryos generated by assisted reproduction technology has been consolidated in the prenatal care framework. The rapid evolution of DNA technologies is tending to molecular approaches. Our intention is to present a detailed methodological view, showing different diagnostic strategies based on molecular techniques that are currently applied in preimplantation genetic diagnosis. The amount of DNA from one single, or a few cells, obtained by embryo biopsy is a limiting factor for the molecular analysis. In this sense, genetic laboratories have developed molecular protocols considering this restrictive condition. Nevertheless, the development of whole-genome amplification methods has allowed preimplantation genetic diagnosis for two or more indications simultaneously, like the selection of histocompatible embryos plus detection of monogenic diseases or aneuploidies. Moreover, molecular techniques have permitted preimplantation genetic screening to progress, by implementing microarray-based comparative genome hybridization. Finally, a future view of the embryo-genetics field based on molecular advances is proposed. The normalization, cost-effectiveness analysis, and new technological tools are the next topics for preimplantation genetic diagnosis and screening. Concomitantly, these additions to assisted reproduction technologies could have a positive effect on the schedules of preimplantation studies.

A New Screening Methodology for Improved Oil Recovery Processes Using Soft-Computing Techniques

NASA Astrophysics Data System (ADS)

Parada, Claudia; Ertekin, Turgay

2010-05-01

The first stage of production of any oil reservoir involves oil displacement by natural drive mechanisms such as solution gas drive, gas cap drive and gravity drainage. Typically, improved oil recovery (IOR) methods are applied to oil reservoirs that have been depleted naturally. In more recent years, IOR techniques are applied to reservoirs even before their natural energy drive is exhausted by primary depletion. Descriptive screening criteria for IOR methods are used to select the appropriate recovery technique according to the fluid and rock properties. This methodology helps in assessing the most suitable recovery process for field deployment of a candidate reservoir. However, the already published screening guidelines neither provide information about the expected reservoir performance nor suggest a set of project design parameters, which can be used towards the optimization of the process. In this study, artificial neural networks (ANN) are used to build a high-performance neuro-simulation tool for screening different improved oil recovery techniques: miscible injection (CO2 and N2), waterflooding and steam injection processes. The simulation tool consists of proxy models that implement a multilayer cascade feedforward back propagation network algorithm. The tool is intended to narrow the ranges of possible scenarios to be modeled using conventional simulation, reducing the extensive time and energy spent in dynamic reservoir modeling. A commercial reservoir simulator is used to generate the data to train and validate the artificial neural networks. The proxy models are built considering four different well patterns with different well operating conditions as the field design parameters. Different expert systems are developed for each well pattern. The screening networks predict oil production rate and cumulative oil production profiles for a given set of rock and fluid properties, and design parameters. The results of this study show that the networks are able to recognize the strong correlation between the displacement mechanism and the reservoir characteristics as they effectively forecast hydrocarbon production for different types of reservoir undergoing diverse recovery processes. The artificial neuron networks are able to capture the similarities between different displacement mechanisms as same network architecture is successfully applied in both CO2 and N2 injection. The neuro-simulation application tool is built within a graphical user interface to facilitate the display of the results. The developed soft-computing tool offers an innovative approach to design a variety of efficient and feasible IOR processes by using artificial intelligence. The tool provides appropriate guidelines to the reservoir engineer, it facilitates the appraisal of diverse field development strategies for oil reservoirs, and it helps to reduce the number of scenarios evaluated with conventional reservoir simulation.

Using the scenario method in the context of health and health care--a scoping review.

PubMed

Vollmar, Horst Christian; Ostermann, Thomas; Redaèlli, Marcus

2015-10-16

The scenario technique is a method for future research and for strategic planning. Today, it includes both qualitative and quantitative elements. The aims of this scoping review are to give an overview of the application of the scenario method in the fields of health care and to make suggestions for better reporting in future scenario projects. Between January 2013 and October 2013 we conducted a systematic search in the databases Medline, Embase, PsycInfo, Eric, The Cochrane Library, Scopus, Web of Science, and Cinahl since inception for the term 'scenario(s)' in combination with other terms, e.g. method, model, and technique. Our search was not restricted by date or language. In addition, we screened the reference lists of the included articles. A total of 576 bibliographical records were screened. After removing duplicates and three rounds of screening, 41 articles covering 38 different scenario projects were included for the final analysis. Nine of the included articles addressed disease related issues, led by mental health and dementia (n = 4), and followed by cancer (n = 3). Five scenario projects focused on public health issues at an organizational level and five focused on the labor market for different health care professionals. In addition, four projects dealt with health care 'in general', four with the field of biotechnology and personalized medicine, and additional four with other technology developments. Some of the scenario projects suffered from poor reporting of methodological aspects. Despite its potential, use of the scenario method seems to be published rarely in comparison to other methods such as the Delphi-technique, at least in the field of health care. This might be due to the complexity of the methodological approach. Individual project methods and activities vary widely and are poorly reported. Improved criteria are required for reporting of scenario project methods. With improved standards and greater transparency, the scenario method will be a good tool for scientific health care planning and strategic decision-making in public health.

[Non-medical applications for brain MRI: Ethical considerations].

PubMed

Sarrazin, S; Fagot-Largeault, A; Leboyer, M; Houenou, J

2015-04-01

The recent neuroimaging techniques offer the possibility to better understand complex cognitive processes that are involved in mental disorders and thus have become cornerstone tools for research in psychiatry. The performances of functional magnetic resonance imaging are not limited to medical research and are used in non-medical fields. These recent applications represent new challenges for bioethics. In this article we aim at discussing the new ethical issues raised by the applications of the latest neuroimaging technologies to non-medical fields. We included a selection of peer-reviewed English medical articles after a search on NCBI Pubmed database and Google scholar from 2000 to 2013. We screened bibliographical tables for supplementary references. Websites of governmental French institutions implicated in ethical questions were also screened for governmental reports. Findings of brain areas supporting emotional responses and regulation have been used for marketing research, also called neuromarketing. The discovery of different brain activation patterns in antisocial disorder has led to changes in forensic psychiatry with the use of imaging techniques with unproven validity. Automated classification algorithms and multivariate statistical analyses of brain images have been applied to brain-reading techniques, aiming at predicting unconscious neural processes in humans. We finally report the current position of the French legislation recently revised and discuss the technical limits of such techniques. In the near future, brain imaging could find clinical applications in psychiatry as diagnostic or predictive tools. However, the latest advances in brain imaging are also used in non-scientific fields raising key ethical questions. Involvement of neuroscientists, psychiatrists, physicians but also of citizens in neuroethics discussions is crucial to challenge the risk of unregulated uses of brain imaging. Copyright © 2014 L’Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Extrafoveal Video Extension for an Immersive Viewing Experience.

PubMed

Turban, Laura; Urban, Fabrice; Guillotel, Philippe

2016-02-11

Between the recent popularity of virtual reality (VR) and the development of 3D, immersion has become an integral part of entertainment concepts. Head-mounted Display (HMD) devices are often used to afford users a feeling of immersion in the environment. Another technique is to project additional material surrounding the viewer, as is achieved using cave systems. As a continuation of this technique, it could be interesting to extend surrounding projection to current television or cinema screens. The idea would be to entirely fill the viewer's field of vision, thus providing them with a more complete feeling of being in the scene and part of the story. The appropriate content can be captured using large field of view (FoV) technology, using a rig of cameras for 110 to 360 capture, or created using computergenerated images. The FoV is, however, rather limited in its use for existing (legacy) content, achieving between 36 to 90 degrees () field, depending on the distance from the screen. This paper seeks to improve this FoV limitation by proposing computer vision techniques to extend such legacy content to the peripheral (extrafoveal) vision without changing the original creative intent or damaging the viewer's experience. A new methodology is also proposed for performing user tests in order to evaluate the quality of the experience and confirm that the sense of immersion has been increased. This paper thus presents: i) an algorithm to spatially extend the video based on human vision characteristics, ii) its subjective results compared to state-of-the-art techniques, iii) the protocol required to evaluate the quality of the experience (QoE), and iv) the results of the user tests.

Two-dimensional airborne ultrasound real-time linear array scanner--applied to screening for scoliosis.

PubMed

Mauritzson, L; Ilver, J; Benoni, G; Lindström, K; Willner, S

1991-01-01

Diagnostic ultrasound is an established, noninvasive and harmless method for imaging the shape and appearance of organs and other tissues inside the body, and it has been used in many clinical applications for more than three decades. We have now applied some of this well-known technique together with the use of airborne ultrasound in medical applications, to build an equipment for anthropometrical investigation outside the body, e.g., measuring and registration of the shape and form of the human back. This is mostly done for screening purposes of young people in an attempt to find patients developing scoliosis, and in order to circumvent some of the disadvantages with the traditional screening method in this field of medical application.

Loop-mediated isothermal DNA amplification for asymptomatic malaria detection in challenging field settings: Technical performance and pilot implementation in the Peruvian Amazon

PubMed Central

Serra-Casas, Elisa; Manrique, Paulo; Ding, Xavier C.; Carrasco-Escobar, Gabriel; Alava, Freddy; Gave, Anthony; Rodriguez, Hugo; Contreras-Mancilla, Juan; Rosas-Aguirre, Angel; Speybroeck, Niko; González, Iveth J.

2017-01-01

Background Loop-mediated isothermal DNA amplification (LAMP) methodology offers an opportunity for point-of-care (POC) molecular detection of asymptomatic malaria infections. However, there is still little evidence on the feasibility of implementing this technique for population screenings in isolated field settings. Methods Overall, we recruited 1167 individuals from terrestrial (‘road’) and hydric (‘riverine’) communities of the Peruvian Amazon for a cross-sectional survey to detect asymptomatic malaria infections. The technical performance of LAMP was evaluated in a subgroup of 503 samples, using real-time Polymerase Chain Reaction (qPCR) as reference standard. The operational feasibility of introducing LAMP testing in the mobile screening campaigns was assessed based on field-suitability parameters, along with a pilot POC-LAMP assay in a riverine community without laboratory infrastructure. Results LAMP had a sensitivity of 91.8% (87.7–94.9) and specificity of 91.9% (87.8–95.0), and the overall accuracy was significantly better among samples collected during road screenings than riverine communities (p≤0.004). LAMP-based diagnostic strategy was successfully implemented within the field-team logistics and the POC-LAMP pilot in the riverine community allowed for a reduction in the turnaround time for case management, from 12–24 hours to less than 5 hours. Specimens with haemolytic appearance were regularly observed in riverine screenings and could help explaining the hindered performance/interpretation of the LAMP reaction in these communities. Conclusions LAMP-based molecular malaria diagnosis can be deployed outside of reference laboratories, providing similar performance as qPCR. However, scale-up in remote field settings such as riverine communities needs to consider a number of logistical challenges (e.g. environmental conditions, labour-intensiveness in large population screenings) that can influence its optimal implementation. PMID:28982155

New technique for installing screen wicking into Inconel 718 heat pipe

NASA Astrophysics Data System (ADS)

Giriunas, Julius A.; Watson, Gordon K.; Tower, Leonard K.

1993-01-01

The creep behavior of superalloys, including Inconel 718, in the presence of liquid sodium is not yet known. To study this problem, the NASA Lewis Research Center has initiated a program with the Energy Technology Engineering Center (ETEC) of Rockwell International Corporation to fill with sodium and creep-test three small cylindrical heat pipes of Inconel 718 for a period of 1000 hours each. This report documents the design and the construction methods that were used at NASA Lewis to fabricate these heat pipes. Of particular importance in the heat pipe construction was the installation of the screen wicking by using an expandable mandrel and differential thermal expansion. This installation technique differs from anything known to have been reported in the heat pipe literature and may be of interest to other workers in the heat pipe field.

Theoretical study of ferroelectric nanoparticles using phase reconstructed electron microscopy

NASA Astrophysics Data System (ADS)

Phatak, C.; Petford-Long, A. K.; Beleggia, M.; De Graef, M.

2014-06-01

Ferroelectric nanostructures are important for a variety of applications in electronic and electro-optical devices, including nonvolatile memories and thin-film capacitors. These applications involve stability and switching of polarization using external stimuli, such as electric fields. We present a theoretical model describing how the shape of a nanoparticle affects its polarization in the absence of screening charges, and quantify the electron-optical phase shift for detecting ferroelectric signals with phase-sensitive techniques in a transmission electron microscope. We provide an example phase shift computation for a uniformly polarized prolate ellipsoid with varying aspect ratio in the absence of screening charges.

Application of the stochastic tunneling method to high throughput database screening

NASA Astrophysics Data System (ADS)

Merlitz, H.; Burghardt, B.; Wenzel, W.

2003-03-01

The stochastic tunneling technique is applied to screen a database of chemical compounds to the active site of dihydrofolate reductase for lead candidates in the receptor-ligand docking problem. Using an atomistic force field we consider the ligand's internal rotational degrees of freedom. It is shown that the natural ligand (methotrexate) scores best among 10 000 randomly chosen compounds. We analyze the top scoring compounds to identify hot-spots of the receptor. We mutate the amino acids that are responsible for the hot-spots of the receptor and verify that its specificity is lost upon modification.

Inoculation Techniques in the Field Screening and Selection for Corn Inbred and Hybirds Resistance to Preharvest Aflatoxin Contamination

USDA-ARS?s Scientific Manuscript database

Preharvest aflatoxin contamination of grain grown on the U.S. Southeastern Coast Plain is provoked and aggravated by both biotic and abiotic stress factors that influence infection by Asperigillus flavus. An array of arthropod species contribute to the dispersal of this fungus as they attack and fee...

A Screen Space GPGPU Surface LIC Algorithm for Distributed Memory Data Parallel Sort Last Rendering Infrastructures

NASA Astrophysics Data System (ADS)

Loring, B.; Karimabadi, H.; Rortershteyn, V.

2015-10-01

The surface line integral convolution(LIC) visualization technique produces dense visualization of vector fields on arbitrary surfaces. We present a screen space surface LIC algorithm for use in distributed memory data parallel sort last rendering infrastructures. The motivations for our work are to support analysis of datasets that are too large to fit in the main memory of a single computer and compatibility with prevalent parallel scientific visualization tools such as ParaView and VisIt. By working in screen space using OpenGL we can leverage the computational power of GPUs when they are available and run without them when they are not. We address efficiency and performance issues that arise from the transformation of data from physical to screen space by selecting an alternate screen space domain decomposition. We analyze the algorithm's scaling behavior with and without GPUs on two high performance computing systems using data from turbulent plasma simulations.

A Screen Space GPGPU Surface LIC Algorithm for Distributed Memory Data Parallel Sort Last Rendering Infrastructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loring, Burlen; Karimabadi, Homa; Rortershteyn, Vadim

2014-07-01

The surface line integral convolution(LIC) visualization technique produces dense visualization of vector fields on arbitrary surfaces. We present a screen space surface LIC algorithm for use in distributed memory data parallel sort last rendering infrastructures. The motivations for our work are to support analysis of datasets that are too large to fit in the main memory of a single computer and compatibility with prevalent parallel scientific visualization tools such as ParaView and VisIt. By working in screen space using OpenGL we can leverage the computational power of GPUs when they are available and run without them when they are not.more » We address efficiency and performance issues that arise from the transformation of data from physical to screen space by selecting an alternate screen space domain decomposition. We analyze the algorithm's scaling behavior with and without GPUs on two high performance computing systems using data from turbulent plasma simulations.« less

Directed evolution: tailoring biocatalysts for industrial applications.

PubMed

Kumar, Ashwani; Singh, Suren

2013-12-01

Current challenges and promises of white biotechnology encourage protein engineers to use a directed evolution approach to generate novel and useful biocatalysts for various sets of applications. Different methods of enzyme engineering have been used in the past in an attempt to produce enzymes with improved functions and properties. Recent advancement in the field of random mutagenesis, screening, selection and computational design increased the versatility and the rapid development of enzymes under strong selection pressure with directed evolution experiments. Techniques of directed evolution improve enzymes fitness without understanding them in great detail and clearly demonstrate its future role in adapting enzymes for use in industry. Despite significant advances to date regarding biocatalyst improvement, there still remains a need to improve mutagenesis strategies and development of easy screening and selection tools without significant human intervention. This review covers fundamental and major development of directed evolution techniques, and highlights the advances in mutagenesis, screening and selection methods with examples of enzymes developed by using these approaches. Several commonly used methods for creating molecular diversity with their advantages and disadvantages including some recently used strategies are also discussed.

Cocrystal screening of hydroxybenzamides with benzoic acid derivatives: a comparative study of thermal and solution-based methods.

PubMed

Manin, Alex N; Voronin, Alexander P; Drozd, Ksenia V; Manin, Nikolay G; Bauer-Brandl, Annette; Perlovich, German L

2014-12-18

The main problem occurring at the early stages of cocrystal search is the choice of an effective screening technique. Among the most popular techniques of obtaining cocrystals are crystallization from solution, crystallization from melt and solvent-drop grinding. This paper represents a comparative analysis of the following screening techniques: DSC cocrystal screening method, thermal microscopy and saturation temperature method. The efficiency of different techniques of cocrystal screening was checked in 18 systems. Benzamide and benzoic acid derivatives were chosen as model systems due to their ability to form acid-amide supramolecular heterosynthon. The screening has confirmed the formation of 6 new cocrystals. The screening by the saturation temperature method has the highest screen-out rate but the smallest range of application. DSC screening has a satisfactory accuracy and allows screening over a short time. Thermal microscopy is most efficient as an additional technique used to interpret ambiguous DSC screening results. The study also included an analysis of the influence of solvent type and component solubility on cocrystal formation. Copyright © 2014 Elsevier B.V. All rights reserved.

Infrared Thermography Approach for Effective Shielding Area of Field Smoke Based on Background Subtraction and Transmittance Interpolation.

PubMed

Tang, Runze; Zhang, Tonglai; Chen, Yongpeng; Liang, Hao; Li, Bingyang; Zhou, Zunning

2018-05-06

Effective shielding area is a crucial indicator for the evaluation of the infrared smoke-obscuring effectiveness on the battlefield. The conventional methods for assessing the shielding area of the smoke screen are time-consuming and labor intensive, in addition to lacking precision. Therefore, an efficient and convincing technique for testing the effective shielding area of the smoke screen has great potential benefits in the smoke screen applications in the field trial. In this study, a thermal infrared sensor with a mid-wavelength infrared (MWIR) range of 3 to 5 μm was first used to capture the target scene images through clear as well as obscuring smoke, at regular intervals. The background subtraction in motion detection was then applied to obtain the contour of the smoke cloud at each frame. The smoke transmittance at each pixel within the smoke contour was interpolated based on the data that was collected from the image. Finally, the smoke effective shielding area was calculated, based on the accumulation of the effective shielding pixel points. One advantage of this approach is that it utilizes only one thermal infrared sensor without any other additional equipment in the field trial, which significantly contributes to the efficiency and its convenience. Experiments have been carried out to demonstrate that this approach can determine the effective shielding area of the field infrared smoke both practically and efficiently.

Current and emerging screening methods to identify post-head-emergence frost adaptation in wheat and barley.

PubMed

Frederiks, T M; Christopher, J T; Harvey, G L; Sutherland, M W; Borrell, A K

2012-09-01

Cereal crops can suffer substantial damage if frosts occur at heading. Identification of post-head-emergence frost (PHEF) resistance in cereals poses a number of unique and difficult challenges. Many decades of research have failed to identify genotypes with PHEF resistance that could offer economically significant benefit to growers. Research and breeding gains have been limited by the available screening systems. Using traditional frost screening systems, genotypes that escape frost injury in trials due to spatial temperature differences and/or small differences in phenology can be misidentified as resistant. We believe that by improving techniques to minimize frost escapes, such 'false-positive' results can be confidently identified and eliminated. Artificial freezing chambers or manipulated natural frost treatments offer many potential advantages but are not yet at the stage where they can be reliably used for frost screening in breeding programmes. Here we describe the development of a novel photoperiod gradient method (PGM) that facilitates screening of genotypes of different phenology under natural field frosts at matched developmental stages. By identifying frost escapes and increasing the efficiency of field screening, the PGM ensures that research effort can be focused on finding genotypes with improved PHEF resistance. To maximize the likelihood of identifying PHEF resistance, we propose that the PGM form part of an integrated strategy to (i) source germplasm;(ii) facilitate high throughput screening; and (iii) permit detailed validation. PGM may also be useful in other studies where either a range of developmental stages and/or synchronized development are desired.

Feasibility study on phyto-remediation techniques for soil contaminated by the Fukushima Dai-Ichi nuclear power plant accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuu Ishimori; Akihiro Sakoda; Mina Yamada

2013-07-01

Tottori University and the Japan Atomic Energy Agency carried out jointly the feasibility study on phyto-remediation techniques, which apply to soil contaminated by the TEPCO's Fukushima Dai-ichi NPP accident. This paper illustrates the results from experimental investigations. Experimental investigations include both water-culture tests and field tests. Several plants, mainly halophytes that can specifically absorb more Na than K, and others like sunflower demonstrated for other domestic large-scale tests, were water-cultured and examined for screening. Easily cultivated and harvested plants without harmful effects on subsequent cultivation were also considered. New Zealand spinach was selected as a candidate for demonstrations in fields.more » The field tests were carried out at two sites of different agricultural types in Minami-soma, Fukushima prefecture. Concentration of {sup 137}Cs in soil is about 4.5 Bq/g-dry as the average of 10 cm depth. The aims of the field tests are to confirm absorption ability and environmental adaptation of the test plants and to document the cost and performance of projects. In conclusion, the absorption of {sup 137}Cs activity per unit area (Bq/m{sup 2}) by New Zealand spinach could be approximately 0.5%. To achieve an effective result in removal of {sup 137}Cs from soil in around a decade, it is required to find the plant which has ten or more times higher absorption capacity than New Zealand spinach. From the consistency of both results in water-culture and field tests, the water-culture test can be valid for screening. In addition, applicable sites will be limited to fields which are too steep or too narrow to use mechanical diggers, and which are free from any restrictions to enter. (authors)« less

A simple low cost latent fingerprint sensor based on deflectometry and WFT analysis

NASA Astrophysics Data System (ADS)

Dhanotia, Jitendra; Chatterjee, Amit; Bhatia, Vimal; Prakash, Shashi

2018-02-01

In criminal investigations, latent fingerprints are one of the most significant forms of evidence and most commonly used forensic investigation tool worldwide. The existing non-contact latent fingerprint detection systems are bulky, expensive and require environment which is shock and vibration resistant, thereby limiting their usability outside the laboratory. In this article, a compact, full field, low cost technique for profiling of fingerprints using deflectometry is proposed. Using inexpensive mobile phone screen based structured illumination, and windowed Fourier transform (WFT) based phase retrieval mechanism, the 2D and 3D phase plots reconstruct the profile information of the fingerprint. The phase information is also used to confirm a match between two fingerprints in real time. Since the proposed technique is non-interferometric, the measurements are least affected by environmental perturbations. Using the proposed technique, a portable sensor capable of field deployment has been realized.

Using voids to unscreen modified gravity

NASA Astrophysics Data System (ADS)

Falck, Bridget; Koyama, Kazuya; Zhao, Gong-Bo; Cautun, Marius

2018-04-01

The Vainshtein mechanism, present in many models of gravity, is very effective at screening dark matter haloes such that the fifth force is negligible and general relativity is recovered within their Vainshtein radii. Vainshtein screening is independent of halo mass and environment, in contrast to e.g. chameleon screening, making it difficult to test. However, our previous studies have found that the dark matter particles in filaments, walls, and voids are not screened by the Vainshtein mechanism. We therefore investigate whether cosmic voids, identified as local density minima using a watershed technique, can be used to test models of gravity that exhibit Vainshtein screening. We measure density, velocity, and screening profiles of stacked voids in cosmological N-body simulations using both dark matter particles and dark matter haloes as tracers of the density field. We find that the voids are completely unscreened, and the tangential velocity and velocity dispersion profiles of stacked voids show a clear deviation from Λ cold dark matter at all radii. Voids have the potential to provide a powerful test of gravity on cosmological scales.

Screen printing technology applied to silicon solar cell fabrication

NASA Technical Reports Server (NTRS)

Thornhill, J. W.; Sipperly, W. E.

1980-01-01

The process for producing space qualified solar cells in both the conventional and wraparound configuration using screen printing techniques was investigated. Process modifications were chosen that could be easily automated or mechanized. Work was accomplished to optimize the tradeoffs associated with gridline spacing, gridline definition and junction depth. An extensive search for possible front contact metallization was completed. The back surface field structures along with the screen printed back contacts were optimized to produce open circuit voltages of at least an average of 600 millivolts. After all intended modifications on the process sequence were accomplished, the cells were exhaustively tested. Electrical tests at AMO and 28 C were made before and after boiling water immersion, thermal shock, and storage under conditions of high temperature and high humidity.

Sensitivity of F-106B Leading-Edge-Vortex Images to Flight and Vapor-Screen Parameters

NASA Technical Reports Server (NTRS)

Lamar, John E.; Johnson, Thomas D., Jr.

1988-01-01

A flight test was undertaken at NASA Langley Research Center with vapor-screen and image-enhancement techniques to obtain qualitative and quantitative information about near-field vortex flows above the wings of fighter aircraft. In particular, the effects of Reynolds and Mach numbers on the vortex system over an angle-of-attack range were sought. The relevance of these flows stems from their present and future use at many points in the flight envelope, especially during transonic maneuvers. The aircraft used in this flight program was the F-106B because it was available and had sufficient wing sweep (60 deg) to generate a significant leading-edge vortex system. The sensitivity of the visual results to vapor screen hardware and to onset flow changes is discussed.

Low-dose chest computed tomography for lung cancer screening among Hodgkin lymphoma survivors: a cost-effectiveness analysis.

PubMed

Wattson, Daniel A; Hunink, M G Myriam; DiPiro, Pamela J; Das, Prajnan; Hodgson, David C; Mauch, Peter M; Ng, Andrea K

2014-10-01

Hodgkin lymphoma (HL) survivors face an increased risk of treatment-related lung cancer. Screening with low-dose computed tomography (LDCT) may allow detection of early stage, resectable cancers. We developed a Markov decision-analytic and cost-effectiveness model to estimate the merits of annual LDCT screening among HL survivors. Population databases and HL-specific literature informed key model parameters, including lung cancer rates and stage distribution, cause-specific survival estimates, and utilities. Relative risks accounted for radiation therapy (RT) technique, smoking status (>10 pack-years or current smokers vs not), age at HL diagnosis, time from HL treatment, and excess radiation from LDCTs. LDCT assumptions, including expected stage-shift, false-positive rates, and likely additional workup were derived from the National Lung Screening Trial and preliminary results from an internal phase 2 protocol that performed annual LDCTs in 53 HL survivors. We assumed a 3% discount rate and a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life year (QALY). Annual LDCT screening was cost effective for all smokers. A male smoker treated with mantle RT at age 25 achieved maximum QALYs by initiating screening 12 years post-HL, with a life expectancy benefit of 2.1 months and an incremental cost of $34,841/QALY. Among nonsmokers, annual screening produced a QALY benefit in some cases, but the incremental cost was not below the WTP threshold for any patient subsets. As age at HL diagnosis increased, earlier initiation of screening improved outcomes. Sensitivity analyses revealed that the model was most sensitive to the lung cancer incidence and mortality rates and expected stage-shift from screening. HL survivors are an important high-risk population that may benefit from screening, especially those treated in the past with large radiation fields including mantle or involved-field RT. Screening may be cost effective for all smokers but possibly not for nonsmokers despite a small life expectancy benefit. Copyright © 2014 Elsevier Inc. All rights reserved.

New test techniques to evaluate near field effects for supersonic store carriage and separation

NASA Technical Reports Server (NTRS)

Sawyer, Wallace C.; Stallings, Robert L., Jr.; Wilcox, Floyd J., Jr.; Blair, A. B., Jr.; Monta, William J.; Plentovich, Elizabeth B.

1989-01-01

Store separation and store carriage drag studies were conducted. A primary purpose is to develop new experimental methods to evaluate near field effects of store separation and levels of store carriage drag associated with a variety of carriage techniques for different store shapes and arrangements. Flow field measurements consisting of surface pressure distributions and vapor screen photographs are used to analyze the variations of the store separation characteristics with cavity geometry. Store carriage drag measurements representative of tangent, semi-submerged, and internal carriage installations are presented and discussed. Results are included from both fully metric models and models with only metric segments (metric pallets) and the relative merits of the two are discussed. Carriage drag measurements for store installations on an aircraft parent body are compared both with prediction methods and with installations on a generic parent body.

Evaluation of modified portable digital camera for screening of diabetic retinopathy.

PubMed

Chalam, Kakarla V; Brar, Vikram S; Keshavamurthy, Ravi

2009-01-01

To describe a portable wide-field noncontact digital camera for posterior segment photography. The digital camera has a compound lens consisting of two optical elements (a 90-dpt and a 20-dpt lens) attached to a 7.2-megapixel camera. White-light-emitting diodes are used to illuminate the fundus and reduce source reflection. The camera settings are set to candlelight mode, the optic zoom standardized to x2.4 and the focus is manually set to 3.0 m. The new technique provides quality wide-angle digital images of the retina (60 degrees ) in patients with dilated pupils, at a fraction of the cost of established digital fundus photography. The modified digital camera is a useful alternative technique to acquire fundus images and provides a tool for screening posterior segment conditions, including diabetic retinopathy in a variety of clinical settings.

The Present and Future of Prostate Cancer Urine Biomarkers

PubMed Central

Rigau, Marina; Olivan, Mireia; Garcia, Marta; Sequeiros, Tamara; Montes, Melania; Colás, Eva; Llauradó, Marta; Planas, Jacques; de Torres, Inés; Morote, Juan; Cooper, Colin; Reventós, Jaume; Clark, Jeremy; Doll, Andreas

2013-01-01

In order to successfully cure patients with prostate cancer (PCa), it is important to detect the disease at an early stage. The existing clinical biomarkers for PCa are not ideal, since they cannot specifically differentiate between those patients who should be treated immediately and those who should avoid over-treatment. Current screening techniques lack specificity, and a decisive diagnosis of PCa is based on prostate biopsy. Although PCa screening is widely utilized nowadays, two thirds of the biopsies performed are still unnecessary. Thus the discovery of non-invasive PCa biomarkers remains urgent. In recent years, the utilization of urine has emerged as an attractive option for the non-invasive detection of PCa. Moreover, a great improvement in high-throughput “omic” techniques has presented considerable opportunities for the identification of new biomarkers. Herein, we will review the most significant urine biomarkers described in recent years, as well as some future prospects in that field. PMID:23774836

3D printing in neurosurgery: A systematic review

PubMed Central

Randazzo, Michael; Pisapia, Jared M.; Singh, Nickpreet; Thawani, Jayesh P.

2016-01-01

Background: The recent expansion of three-dimensional (3D) printing technology into the field of neurosurgery has prompted a widespread investigation of its utility. In this article, we review the current body of literature describing rapid prototyping techniques with applications to the practice of neurosurgery. Methods: An extensive and systematic search of the Compendex, Scopus, and PubMed medical databases was conducted using keywords relating to 3D printing and neurosurgery. Results were manually screened for relevance to applications within the field. Results: Of the search results, 36 articles were identified and included in this review. The articles spanned the various subspecialties of the field including cerebrovascular, neuro-oncologic, spinal, functional, and endoscopic neurosurgery. Conclusions: We conclude that 3D printing techniques are practical and anatomically accurate methods of producing patient-specific models for surgical planning, simulation and training, tissue-engineered implants, and secondary devices. Expansion of this technology may, therefore, contribute to advancing the neurosurgical field from several standpoints. PMID:27920940

Gene and protein expression following exposure to radiofrequency fields from mobile phones.

PubMed

Vanderstraeten, Jacques; Verschaeve, Luc

2008-09-01

Since 1999, several articles have been published on genome-wide and/or proteome-wide response after exposure to radiofrequency (RF) fields whose signal and intensities were similar to or typical of those of currently used mobile telephones. These studies were performed using powerful high-throughput screening techniques (HTSTs) of transcriptomics and/or proteomics, which allow for the simultaneous screening of the expression of thousands of genes or proteins. We reviewed these HTST-based studies and compared the results with currently accepted concepts about the effects of RF fields on gene expression. In this article we also discuss these last in light of the recent concept of microwave-assisted chemistry. To date, the results of HTST-based studies of transcriptomics and/or proteomics after exposure to RF fields relevant to human exposure are still inconclusive, as most of the positive reports are flawed by methodologic imperfections or shortcomings. In addition, when positive findings were reported, no precise response pattern could be identified in a reproducible way. In particular, results from HTST studies tend to exclude the role of a cell stressor for exposure to RF fields at nonthermal intensities. However, on the basis of lessons from microwave-assisted chemistry, we can assume that RF fields might affect heat-sensitive gene or protein expression to an extent larger than would be predicted from temperature change only. But in all likelihood, this would concern intensities higher than those relevant to usual human exposure. The precise role of transcriptomics and proteomics in the screening of bioeffects from exposure to RF fields from mobile phones is still uncertain in view of the lack of positively identified phenotypic change and the lack of theoretical, as well as experimental, arguments for specific gene and/or protein response patterns after this kind of exposure.

Digital mammography: physical principles and future applications.

PubMed

Gambaccini, Mauro; Baldelli, Paola

2003-01-01

Mammography is currently considered the best tool for the detection of breast cancer, pathology with a rate of incidence in constant increase. To produce the radiological picture a screen film combination is conventionally used. One of the inherent limitations of screen- film combination is the fact that the detection, display and storage processes are one and the same, making it impossible to separately optimize each stage. These limitations can be overcome with digital systems. In this work we evaluate the main characteristics of digital detectors available on the market and we compare the performance of digital and conventional systems. Digital mammography, due to the possibility to process images, offers many potential advantages, among these the possibility to introduce the dual-energy technique which employs the composition of two digital images obtained with two different energies to enhance the inherent contrast of pathologies by removing the uniform background. This technique was previously tested by using synchrotron monochromatic beam and a digital detector, and then the Senographe 2000D full-field digital system manufactured by GE Medical Systems. In this work we present preliminary results and the future applications of this technique.

Evaluation of a rapid diagnostic field test kit for identification of Phytophthora ramorum, P. kernoviae and other Phytophthora species at the point of inspection

Treesearch

C.R. Lane; E. Hobden; L. Laurenson; V.C. Barton; K.J.D. Hughes; H. Swan; N. Boonham; A.J. Inman

2008-01-01

Plant health regulations to prevent the introduction and spread of Phytophthora ramorum and P. kernoviae require rapid, cost effective diagnostic methods for screening large numbers of plant samples at the time of inspection. Current on-site techniques require expensive equipment, considerable expertise and are not suited for plant...

Studying circadian rhythm and sleep using genetic screens in Drosophila.

PubMed

Axelrod, Sofia; Saez, Lino; Young, Michael W

2015-01-01

The power of Drosophila melanogaster as a model organism lies in its ability to be used for large-scale genetic screens with the capacity to uncover the genetic basis of biological processes. In particular, genetic screens for circadian behavior, which have been performed since 1971, allowed researchers to make groundbreaking discoveries on multiple levels: they discovered that there is a genetic basis for circadian behavior, they identified the so-called core clock genes that govern this process, and they started to paint a detailed picture of the molecular functions of these clock genes and their encoded proteins. Since the discovery that fruit flies sleep in 2000, researchers have successfully been using genetic screening to elucidate the many questions surrounding this basic animal behavior. In this chapter, we briefly recall the history of circadian rhythm and sleep screens and then move on to describe techniques currently employed for mutagenesis and genetic screening in the field. The emphasis lies on comparing the newer approaches of transgenic RNA interference (RNAi) to classical forms of mutagenesis, in particular in their application to circadian behavior and sleep. We discuss the different screening approaches in light of the literature and published and unpublished sleep and rhythm screens utilizing ethyl methanesulfonate mutagenesis and transgenic RNAi from our lab. © 2015 Elsevier Inc. All rights reserved.

Ultrasonic multi-skip tomography for pipe inspection

NASA Astrophysics Data System (ADS)

Volker, Arno; Vos, Rik; Hunter, Alan; Lorenz, Maarten

2012-05-01

The inspection of wall loss corrosion is difficult at pipe support locations due to limited accessibility. However, the recently developed ultrasonic Multi-Skip screening technique is suitable for this problem. The method employs ultrasonic transducers in a pitch-catch geometry positioned on opposite sides of the pipe support. Shear waves are transmitted in the axial direction within the pipe wall, reflecting multiple times between the inner and outer surfaces before reaching the receivers. Along this path, the signals accumulate information on the integral wall thickness (e.g., via variations in travel time). The method is very sensitive in detecting the presence of wall loss, but it is difficult to quantify both the extent and depth of the loss. If the extent is unknown, then only a conservative estimate of the depth can be made due to the cumulative nature of the travel time variations. Multi-Skip tomography is an extension of Multi-Skip screening and has shown promise as a complimentary follow-up inspection technique. In recent work, we have developed the technique and demonstrated its use for reconstructing high-resolution estimates of pipe wall thickness profiles. The method operates via a model-based full wave field inversion; this consists of a forward model for predicting the measured wave field and an iterative process that compares the predicted and measured wave fields and minimizes the differences with respect to the model parameters (i.e., the wall thickness profile). This paper presents our recent developments in Multi-Skip tomographic inversion, focusing on the initial localization of corrosion regions for efficient parameterization of the surface profile model and utilization of the signal phase information for improving resolution.

A Multi-Functional Imaging Approach to High-Content Protein Interaction Screening

PubMed Central

Matthews, Daniel R.; Fruhwirth, Gilbert O.; Weitsman, Gregory; Carlin, Leo M.; Ofo, Enyinnaya; Keppler, Melanie; Barber, Paul R.; Tullis, Iain D. C.; Vojnovic, Borivoj; Ng, Tony; Ameer-Beg, Simon M.

2012-01-01

Functional imaging can provide a level of quantification that is not possible in what might be termed traditional high-content screening. This is due to the fact that the current state-of-the-art high-content screening systems take the approach of scaling-up single cell assays, and are therefore based on essentially pictorial measures as assay indicators. Such phenotypic analyses have become extremely sophisticated, advancing screening enormously, but this approach can still be somewhat subjective. We describe the development, and validation, of a prototype high-content screening platform that combines steady-state fluorescence anisotropy imaging with fluorescence lifetime imaging (FLIM). This functional approach allows objective, quantitative screening of small molecule libraries in protein-protein interaction assays. We discuss the development of the instrumentation, the process by which information on fluorescence resonance energy transfer (FRET) can be extracted from wide-field, acceptor fluorescence anisotropy imaging and cross-checking of this modality using lifetime imaging by time-correlated single-photon counting. Imaging of cells expressing protein constructs where eGFP and mRFP1 are linked with amino-acid chains of various lengths (7, 19 and 32 amino acids) shows the two methodologies to be highly correlated. We validate our approach using a small-scale inhibitor screen of a Cdc42 FRET biosensor probe expressed in epidermoid cancer cells (A431) in a 96 microwell-plate format. We also show that acceptor fluorescence anisotropy can be used to measure variations in hetero-FRET in protein-protein interactions. We demonstrate this using a screen of inhibitors of internalization of the transmembrane receptor, CXCR4. These assays enable us to demonstrate all the capabilities of the instrument, image processing and analytical techniques that have been developed. Direct correlation between acceptor anisotropy and donor FLIM is observed for FRET assays, providing an opportunity to rapidly screen proteins, interacting on the nano-meter scale, using wide-field imaging. PMID:22506000

Population-based mammography screening: comparison of screen-film and full-field digital mammography with soft-copy reading--Oslo I study.

PubMed

Skaane, Per; Young, Kari; Skjennald, Arnulf

2003-12-01

To compare screen-film and full-field digital mammography with soft-copy reading in a population-based screening program. Full-field digital and screen-film mammography were performed in 3,683 women aged 50-69 years. Two standard views of each breast were acquired with each modality. Images underwent independent double reading with use of a five-point rating scale for probability of cancer. Recall rates and positive predictive values were calculated. Cancer detection rates determined with both modalities were compared by using the McNemar test for paired proportions. Retrospective side-by-side analysis for conspicuity of cancers was performed by an external independent radiologist group with experience in both modalities. In 3,683 cases, 31 cancers were detected. Screen-film mammography depicted 28 (0.76%) malignancies, and full-field digital mammography depicted 23 (0.62%) malignancies. The difference between cancer detection rates was not significant (P =.23). The recall rate for full-field digital mammography (4.6%; 168 of 3,683 cases) was slightly higher than that for screen-film mammography (3.5%; 128 of 3,683 cases). The positive predictive value based on needle biopsy results was 46% for screen-film mammography and 39% for full-field digital mammography. Side-by-side image comparison for cancer conspicuity led to classification of 19 cancers as equal for probability of malignancy, six cancers as slightly better demonstrated at screen-film mammography, and six cancers as slightly better demonstrated at full-field digital mammography. There was no statistically significant difference in cancer detection rate between screen-film and full-field digital mammography. Cancer conspicuity was equal with both modalities. Full-field digital mammography with soft-copy reading is comparable to screen-film mammography in population-based screening.

High-quality and small-capacity e-learning video featuring lecturer-superimposing PC screen images

NASA Astrophysics Data System (ADS)

Nomura, Yoshihiko; Murakami, Michinobu; Sakamoto, Ryota; Sugiura, Tokuhiro; Matsui, Hirokazu; Kato, Norihiko

2006-10-01

Information processing and communication technology are progressing quickly, and are prevailing throughout various technological fields. Therefore, the development of such technology should respond to the needs for improvement of quality in the e-learning education system. The authors propose a new video-image compression processing system that ingeniously employs the features of the lecturing scene. While dynamic lecturing scene is shot by a digital video camera, screen images are electronically stored by a PC screen image capturing software in relatively long period at a practical class. Then, a lecturer and a lecture stick are extracted from the digital video images by pattern recognition techniques, and the extracted images are superimposed on the appropriate PC screen images by off-line processing. Thus, we have succeeded to create a high-quality and small-capacity (HQ/SC) video-on-demand educational content featuring the advantages: the high quality of image sharpness, the small electronic file capacity, and the realistic lecturer motion.

Maximum unbiased validation (MUV) data sets for virtual screening based on PubChem bioactivity data.

PubMed

Rohrer, Sebastian G; Baumann, Knut

2009-02-01

Refined nearest neighbor analysis was recently introduced for the analysis of virtual screening benchmark data sets. It constitutes a technique from the field of spatial statistics and provides a mathematical framework for the nonparametric analysis of mapped point patterns. Here, refined nearest neighbor analysis is used to design benchmark data sets for virtual screening based on PubChem bioactivity data. A workflow is devised that purges data sets of compounds active against pharmaceutically relevant targets from unselective hits. Topological optimization using experimental design strategies monitored by refined nearest neighbor analysis functions is applied to generate corresponding data sets of actives and decoys that are unbiased with regard to analogue bias and artificial enrichment. These data sets provide a tool for Maximum Unbiased Validation (MUV) of virtual screening methods. The data sets and a software package implementing the MUV design workflow are freely available at http://www.pharmchem.tu-bs.de/lehre/baumann/MUV.html.

Enhanced electrical properties of textured NBBT ceramics derived from the screen printing technique.

PubMed

Wu, Mengjia; Wang, Youliang; Wang, Dong; Li, Yongxiang

2011-10-01

(001)(pc)-oriented (Na(0.5)Bi(0.5))(0.94)Ba(0.06)TiO(3) (NBBT) lead-free piezoelectric ceramics were fabricated by the screen printing technique using Na(0.5)Bi(0.5)TiO(3) (NBT) templates. The plate-like NBT template particles were synthesized from bismuth layer-structured ferroelectric Bi(4)Ti(3)O(12) (BiT) precursors by the topochemical method. The screen printed NBBT ceramics with 20 wt% NBT templates contained a large fraction of grains aligned with their c-axis normal to the sample surface, giving a Lotgering factor of 0.486. The dielectric and ferroelectric properties of textured NBBT ceramics were anisotropic. Compared with the non-textured NBBT ceramics, the dielectric, ferroelectric, and piezoelectric properties of the textured NBBT ceramics were improved, giving a dielectric constant ϵ(T)(33)/ϵ(0) of 910, a remnant polarization P(r) of 29.2 μC/cm(2), a coercive field E(c) of 23.5 kV/cm, a piezoelectric coefficient d(33) of 180 pC/N, and a thickness-mode electromechanical coupling coefficient k(t) of 0.485.

Automation to improve efficiency of field expedient injury prediction screening.

PubMed

Teyhen, Deydre S; Shaffer, Scott W; Umlauf, Jon A; Akerman, Raymond J; Canada, John B; Butler, Robert J; Goffar, Stephen L; Walker, Michael J; Kiesel, Kyle B; Plisky, Phillip J

2012-07-01

Musculoskeletal injuries are a primary source of disability in the U.S. Military. Physical training and sports-related activities account for up to 90% of all injuries, and 80% of these injuries are considered overuse in nature. As a result, there is a need to develop an evidence-based musculoskeletal screen that can assist with injury prevention. The purpose of this study was to assess the capability of an automated system to improve the efficiency of field expedient tests that may help predict injury risk and provide corrective strategies for deficits identified. The field expedient tests include survey questions and measures of movement quality, balance, trunk stability, power, mobility, and foot structure and mobility. Data entry for these tests was automated using handheld computers, barcode scanning, and netbook computers. An automated algorithm for injury risk stratification and mitigation techniques was run on a server computer. Without automation support, subjects were assessed in 84.5 ± 9.1 minutes per subject compared with 66.8 ± 6.1 minutes per subject with automation and 47.1 ± 5.2 minutes per subject with automation and process improvement measures (p < 0.001). The average time to manually enter the data was 22.2 ± 7.4 minutes per subject. An additional 11.5 ± 2.5 minutes per subject was required to manually assign an intervention strategy. Automation of this injury prevention screening protocol using handheld devices and netbook computers allowed for real-time data entry and enhanced the efficiency of injury screening, risk stratification, and prescription of a risk mitigation strategy.

Maximizing biomass production in semi-arid regions: genotypic selection of identified species. [Saltbush and Johnson Grass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goodin, J.R.; Newton, R.J.

1983-08-31

This project identifies genotypes selected from two species of unconventional plants previously identified as having exceptional potential for the production of biomass feedstock in semi-arid regions. The project involved collection of germ plasm from indigenous Atriplex canescens (saltbush) and introduced Sorghum halepense (Johnson grass). In addition, greenhouse and field screening techniques recently aplied to domesticated crop plants are used to identify exceptional biomass productivity based on drought tolerance, salinity tolerance, and seedling vigor. In both of these species, the genetic base is enormous. Saltbush is common to all of western North America, and Johnsongrass had established itself as an importantmore » forage and weedy species throughout most of the world. It would appear that artificial selection for desirable genotypes is a feasible process, and this project has demonstrated the possibility of selection from many accessions from the field. Preliminary screening for seedling vigor, drought tolerance, and salt tolerance has produced a few genotypes now ready for field testing. Propagation of these cloned genotypes is underway. 22 references, 2 figures, 1 table.« less

Low Cost Dewatering of Waste Slurries

NASA Technical Reports Server (NTRS)

Peterson, J. B.; Sharma, S. K.; Church, R. H.; Scheiner, B. J.

1993-01-01

The U.S. Bureau of Mines has developed a technique for dewatering mineral waste slurries which utilizes polymer and a static screen. A variety of waste slurries from placer gold mines and crushed stone operations have been successfully treated using the system. Depending on the waste, a number of polymers have been used successfully with polymer costs ranging from $0.05 to $0.15 per 1,000 gal treated. The dewatering is accomplished using screens made from either ordinary window screen or wedge wire. The screens used are 8 ft wide and 8 ft long. The capacity of the screens varies from 3 to 7 gpm/sq. ft. The water produced is acceptable for recycling to the plant or for discharge to the environment. For example, a fine grain dolomite waste slurry produced from a crushed stone operation was dewatered from a nominal 2.5 pct solids to greater than 50 pct solids using $0.10 to $0.15 worth of polymer per 1,000 gal of slurry. The resulting waste water had a turbidity of less than 50 NTU and could be discharged or recycled. The paper describes field tests conducted using the polymer-screen dewatering system.

High-resolution mass spectrometry in toxicology: current status and future perspectives.

PubMed

Maurer, H H; Meyer, Markus R

2016-09-01

This paper reviews high-resolution mass spectrometry (HRMS) approaches using time-of-flight or Orbitrap techniques for research and application in various toxicology fields, particularly in clinical toxicology and forensic toxicology published since 2013 and referenced in PubMed. In the introduction, an overview on applications of HRMS in various toxicology fields is given with reference to current review articles. Papers concerning HRMS in metabolism, screening, and quantification of pharmaceuticals, drugs of abuse, and toxins in human body samples are critically reviewed. Finally, a discussion on advantages as well as limitations and future perspectives of these methods is included.

Electrostatic Insect Sweeper for Eliminating Whiteflies Colonizing Host Plants: A Complementary Pest Control Device in An Electric Field Screen-Guarded Greenhouse.

PubMed

Takikawa, Yoshihiro; Matsuda, Yoshinori; Kakutani, Koji; Nonomura, Teruo; Kusakari, Shin-Ichi; Okada, Kiyotsugu; Kimbara, Junji; Osamura, Kazumi; Toyoda, Hideyoshi

2015-05-12

Our greenhouse tomatoes have suffered from attacks by viruliferous whiteflies Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) over the last 10 years. The fundamental countermeasure was the application of an electric field screen to the greenhouse windows to prevent their entry. However, while the protection was effective, it was incomplete, because of the lack of a guard at the greenhouse entrance area; in fact, the pests entered from the entrance door when workers entered and exited. To address this, we developed a portable electrostatic insect sweeper as a supplementary technique to the screen. In this sweeper, eight insulated conductor wires (ICWs) were arranged at constant intervals along a polyvinylchloride (PVC) pipe and covered with a cylindrical stainless net. The ICWs and metal net were linked to a DC voltage generator (operated by 3-V alkaline batteries) inside the grip and oppositely electrified to generate an electric field between them. Whiteflies on the plants were attracted to the sweeper that was gently slid along the leaves. This apparatus was easy to operate on-site in a greenhouse and enabled capture of the whiteflies detected during the routine care of the tomato plants. Using this apparatus, we caught all whiteflies that invaded the non-guarded entrance door and minimized the appearance and spread of the viral disease in tomato plants in the greenhouse.

Halftoning and Image Processing Algorithms

DTIC Science & Technology

1999-02-01

screening techniques with the quality advantages of error diffusion in the half toning of color maps, and on color image enhancement for halftone ...image quality. Our goals in this research were to advance the understanding in image science for our new halftone algorithm and to contribute to...image retrieval and noise theory for such imagery. In the field of color halftone printing, research was conducted on deriving a theoretical model of our

Novel throughput phenotyping platforms in plant genetic studies.

PubMed

Montes, Juan M; Melchinger, Albrecht E; Reif, Jochen C

2007-10-01

Unraveling the genetic basis of complex traits in plants is limited by the lack of appropriate phenotyping platforms that enable high-throughput screening of many genotypes in multilocation field trials. Near-infrared spectroscopy on agricultural harvesters and spectral reflectance of plant canopies have recently been reported as promising components of novel phenotyping platforms. Understanding the genetic basis of complex traits is now within reach with the use of these new techniques.

RELIABILITY OF THE TUCK JUMP INJURY RISK SCREENING ASSESSMENT IN ELITE MALE YOUTH SOCCER PLAYERS

PubMed Central

READ, PAUL; OLIVER, JON L.; DE STE CROIX, MARK B.A.; MYER, GREGORY D.; LLOYD, RHODRI S.

2015-01-01

Altered neuromuscular control has been suggested as a mechanism for injury in soccer players. Ligamentous injuries most often occur during dynamic movements, such as decelerations from jump-landing maneuvers where high risk movement patterns are present. The assessment of kinematic variables during jump-landing tasks as part of a pre-participation screen is useful in the identification of injury risk. An example of a field-based screening tool is the repeated tuck jump assessment. The purpose of this study was to analyze the within-subject variation of the tuck jump screening assessment in elite male youth soccer players. 25 pre and 25 post-peak height velocity (PHV) elite male youth soccer players from the academy of a professional English soccer club completed the assessment. A test, re-test design was used to explore the within-subject inter-session reliability. Technique was graded retrospectively against the 10-point criteria set out in the screening protocol using two-dimensional video cameras. The typical error range reported for tuck jump total score (0.90 – 1.01 in pre and post-PHV players respectively) was considered acceptable. When each criteria was analyzed individually, Kappa coefficient determined that knee valgus was the only criterion to reach substantial agreement across the two test sessions for both groups. The results of this study suggest that although tuck jump total score may be reliably assessed in elite male youth soccer players, caution should be applied in solely interpreting the composite score due to the high within-subject variation in a number of the individual criteria. Knee valgus may be reliably used to screen elite youth male soccer players for this plyometric technique error and for test, re-test comparison. PMID:26562715

Low-Dose Chest Computed Tomography for Lung Cancer Screening Among Hodgkin Lymphoma Survivors: A Cost-Effectiveness Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wattson, Daniel A., E-mail: dwattson@partners.org; Hunink, M.G. Myriam; DiPiro, Pamela J.

2014-10-01

Purpose: Hodgkin lymphoma (HL) survivors face an increased risk of treatment-related lung cancer. Screening with low-dose computed tomography (LDCT) may allow detection of early stage, resectable cancers. We developed a Markov decision-analytic and cost-effectiveness model to estimate the merits of annual LDCT screening among HL survivors. Methods and Materials: Population databases and HL-specific literature informed key model parameters, including lung cancer rates and stage distribution, cause-specific survival estimates, and utilities. Relative risks accounted for radiation therapy (RT) technique, smoking status (>10 pack-years or current smokers vs not), age at HL diagnosis, time from HL treatment, and excess radiation from LDCTs.more » LDCT assumptions, including expected stage-shift, false-positive rates, and likely additional workup were derived from the National Lung Screening Trial and preliminary results from an internal phase 2 protocol that performed annual LDCTs in 53 HL survivors. We assumed a 3% discount rate and a willingness-to-pay (WTP) threshold of $50,000 per quality-adjusted life year (QALY). Results: Annual LDCT screening was cost effective for all smokers. A male smoker treated with mantle RT at age 25 achieved maximum QALYs by initiating screening 12 years post-HL, with a life expectancy benefit of 2.1 months and an incremental cost of $34,841/QALY. Among nonsmokers, annual screening produced a QALY benefit in some cases, but the incremental cost was not below the WTP threshold for any patient subsets. As age at HL diagnosis increased, earlier initiation of screening improved outcomes. Sensitivity analyses revealed that the model was most sensitive to the lung cancer incidence and mortality rates and expected stage-shift from screening. Conclusions: HL survivors are an important high-risk population that may benefit from screening, especially those treated in the past with large radiation fields including mantle or involved-field RT. Screening may be cost effective for all smokers but possibly not for nonsmokers despite a small life expectancy benefit.« less

Simulation assessment of the direct‐push permeameter for characterizing vertical variations in hydraulic conductivity

USGS Publications Warehouse

Liu, Gaisheng; Bohling, Geoffrey C.; Butler, James J.

2008-01-01

The direct‐push permeameter (DPP) is a tool for the in situ characterization of hydraulic conductivity (K) in shallow, unconsolidated formations. This device, which consists of a short screened section with a pair of pressure transducers near the screen, is advanced into the subsurface with direct‐push technology. K is determined through a series of injection tests conducted between advancements. Recent field work by Butler et al. (2007) has shown that the DPP holds great potential for describing vertical variations in K at an unprecedented level of detail, accuracy and speed. In this paper, the fundamental efficacy of the DPP is evaluated through a series of numerical simulations. These simulations demonstrate that the DPP can provide accurate K information under conditions commonly faced in the field. A single DPP test provides an effective K for the domain immediately surrounding the interval between the injection screen and the most distant pressure transducer. Features that are thinner than that interval can be quantified by reducing the vertical distance between successive tests and analyzing the data from all tests simultaneously. A particular advantage of the DPP is that, unlike most other single borehole techniques, a low‐K skin or a clogged screen has a minimal impact on the K estimate. In addition, the requirement that only steady‐shape conditions be attained allows for a dramatic reduction in the time required for each injection test.

Taguchi's technique: an effective method for improving X-ray medical radiographic screen performance.

PubMed

Vlachogiannis, J G

2003-01-01

Taguchi's technique is a helpful tool to achieve experimental optimization of a large number of decision variables with a small number of off-line experiments. The technique appears to be an ideal tool for improving the performance of X-ray medical radiographic screens under a noise source. Currently there are very many guides available for improving the efficiency of X-ray medical radiographic screens. These guides can be refined using a second-stage parameter optimization. based on Taguchi's technique, selecting the optimum levels of controllable X-ray radiographic screen factors. A real example of the proposed technique is presented giving certain performance criteria. The present research proposes the reinforcement of X-ray radiography by Taguchi's technique as a novel hardware mechanism.

Gas pressure assisted microliquid-liquid extraction coupled online to direct infusion mass spectrometry: a new automated screening platform for bioanalysis.

PubMed

Raterink, Robert-Jan; Witkam, Yoeri; Vreeken, Rob J; Ramautar, Rawi; Hankemeier, Thomas

2014-10-21

In the field of bioanalysis, there is an increasing demand for miniaturized, automated, robust sample pretreatment procedures that can be easily connected to direct-infusion mass spectrometry (DI-MS) in order to allow the high-throughput screening of drugs and/or their metabolites in complex body fluids like plasma. Liquid-Liquid extraction (LLE) is a common sample pretreatment technique often used for complex aqueous samples in bioanalysis. Despite significant developments that have been made in automated and miniaturized LLE procedures, fully automated LLE techniques allowing high-throughput bioanalytical studies on small-volume samples using direct infusion mass spectrometry, have not been matured yet. Here, we introduce a new fully automated micro-LLE technique based on gas-pressure assisted mixing followed by passive phase separation, coupled online to nanoelectrospray-DI-MS. Our method was characterized by varying the gas flow and its duration through the solvent mixture. For evaluation of the analytical performance, four drugs were spiked to human plasma, resulting in highly acceptable precision (RSD down to 9%) and linearity (R(2) ranging from 0.990 to 0.998). We demonstrate that our new method does not only allow the reliable extraction of analytes from small sample volumes of a few microliters in an automated and high-throughput manner, but also performs comparable or better than conventional offline LLE, in which the handling of small volumes remains challenging. Finally, we demonstrate the applicability of our method for drug screening on dried blood spots showing excellent linearity (R(2) of 0.998) and precision (RSD of 9%). In conclusion, we present the proof of principe of a new high-throughput screening platform for bioanalysis based on a new automated microLLE method, coupled online to a commercially available nano-ESI-DI-MS.

Current issues and future perspectives of gastric cancer screening

PubMed Central

Hamashima, Chisato

2014-01-01

Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening. PMID:25320514

A Technique to Screen American Beech for Resistance to the Beech Scale Insect (Cryptococcus fagisuga Lind.)

PubMed Central

Koch, Jennifer L.; Carey, David W.

2014-01-01

Beech bark disease (BBD) results in high levels of initial mortality, leaving behind survivor trees that are greatly weakened and deformed. The disease is initiated by feeding activities of the invasive beech scale insect, Cryptococcus fagisuga, which creates entry points for infection by one of the Neonectria species of fungus. Without scale infestation, there is little opportunity for fungal infection. Using scale eggs to artificially infest healthy trees in heavily BBD impacted stands demonstrated that these trees were resistant to the scale insect portion of the disease complex1. Here we present a protocol that we have developed, based on the artificial infestation technique by Houston2, which can be used to screen for scale-resistant trees in the field and in smaller potted seedlings and grafts. The identification of scale-resistant trees is an important component of management of BBD through tree improvement programs and silvicultural manipulation. PMID:24894494

Local gas injection as a scrape-off layer diagnostic on the Alcator C-Mod tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jablonski, David F.

1996-05-01

A capillary puffing array has been installed on Alcator C-Mod which allows localized introduction of gaseous species in the scrape-off layer. This system has been utilized in experiments to elucidate both global and local properties of edge transport. Deuterium fueling and recycling impurity screening are observed to be characterized by non-dimensional screening efficiencies which are independent of the location of introduction. In contrast, the behavior of non-recycling impurities is seen to be characterized by a screening time which is dependent on puff location. The work of this thesis has focused on the use of the capillary array with a cameramore » system which can view impurity line emission plumes formed in the region of an injection location. The ionic plumes observed extend along the magnetic field line with a comet-like asymmetry, indicative of background plasma ion flow. The flow is observed to be towards the nearest strike-point, independent of x-point location, magnetic field direction, and other plasma parameters. While the axes of the plumes are generally along the field line, deviations are seen which indicate cross-field ion drifts. A quasi-two dimensional fluid model has been constructed to use the plume shapes of the first charge state impurity ions to extract information about the local background plasma, specifically the temperature, parallel flow velocity, and radial electric field. Through comparisons of model results with those of a three dimensional Monte Carlo code, and comparisons of plume extracted parameters with scanning probe measurements, the efficacy of the model is demonstrated. Plume analysis not only leads to understandings of local edge impurity transport, but also presents a novel diagnostic technique.« less

Approaches to virtual screening and screening library selection.

PubMed

Wildman, Scott A

2013-01-01

The ease of access to virtual screening (VS) software in recent years has resulted in a large increase in literature reports. Over 300 publications in the last year report the use of virtual screening techniques to identify new chemical matter or present the development of new virtual screening techniques. The increased use is accompanied by a corresponding increase in misuse and misinterpretation of virtual screening results. This review aims to identify many of the common difficulties associated with virtual screening and allow researchers to better assess the reliability of their virtual screening effort.

Dysphagia Screening: Contributions of Cervical Auscultation Signals and Modern Signal-Processing Techniques

PubMed Central

Dudik, Joshua M.; Coyle, James L.

2015-01-01

Cervical auscultation is the recording of sounds and vibrations caused by the human body from the throat during swallowing. While traditionally done by a trained clinician with a stethoscope, much work has been put towards developing more sensitive and clinically useful methods to characterize the data obtained with this technique. The eventual goal of the field is to improve the effectiveness of screening algorithms designed to predict the risk that swallowing disorders pose to individual patients’ health and safety. This paper provides an overview of these signal processing techniques and summarizes recent advances made with digital transducers in hopes of organizing the highly varied research on cervical auscultation. It investigates where on the body these transducers are placed in order to record a signal as well as the collection of analog and digital filtering techniques used to further improve the signal quality. It also presents the wide array of methods and features used to characterize these signals, ranging from simply counting the number of swallows that occur over a period of time to calculating various descriptive features in the time, frequency, and phase space domains. Finally, this paper presents the algorithms that have been used to classify this data into ‘normal’ and ‘abnormal’ categories. Both linear as well as non-linear techniques are presented in this regard. PMID:26213659

Pain and stress assessment after retinopathy of prematurity screening examination: Indirect ophthalmoscopy versus digital retinal imaging

PubMed Central

2012-01-01

Background Increasingly, neonatal clinics seek to minimize painful experiences and stress for premature infants. Fundoscopy performed with a binocular indirect ophthalmoscope is the reference examination technique for screening of retinopathy of prematurity (ROP), and it is associated with pain and stress. Wide-field digital retinal imaging is a recent technique that should be evaluated for minimizing infant pain and stress. Methods The purpose of the study was to assess and compare the impact of using a binocular indirect ophthalmoscope (BIO), or wide-field digital retinal imaging (WFDRI) on pain and stress in infants undergoing ROP screening examination. This was a comparative evaluation study of two screening procedures. Ophthalmologic examinations (N = 70) were performed on 24 infants with both BIO and WFDRI. Pain assessments were performed with two specific neonatal scales (Crying, requires oxygen, increased vital signs, expression and sleeplessness, CRIES and, Premature infant pain profile, PIPP) just prior to the examination, and 30 seconds, 1 hour, and 24 hours later after ending the examination. Results Changes over time were significantly different between BIO and WFDRI with both scales (PIPP score, p = .007, and CRIES score, p = .001). Median PIPP score (interquartile interval) at baseline was 4 (3–5). At 30 seconds the score was 8 (6–9) for BIO and 6 (5–7) for WFDRI, respectively. The increase in PIPP score between baseline and 30 seconds was significantly lower with WFDRI (p = .006). The median increase in CRIES score from baseline to 30 seconds was 1 point lower for WFDRI than for BIO (p < .001). No significant difference in response remained at 1 hour or 24 hour assessments. Conclusions A transient short-term pain and stress response occurs with both BIO and WFDRI. Infants examined for screening of ROP with digital retinal imaging present less pain and stress at 30 seconds following completion of the exam when compared with binocular indirect ophthalmoscopy. PMID:22928523

Fundamental study of flow field generated by rotorcraft blades using wide-field shadowgraph

NASA Technical Reports Server (NTRS)

Parthasarathy, S. P.; Cho, Y. I.; Back, L. H.

1985-01-01

The vortex trajectory and vortex wake generated by helicopter rotors are visualized using a wide-field shadowgraph technique. Use of a retro-reflective Scotchlite screen makes it possible to investigate the flow field generated by full-scale rotors. Tip vortex trajectories are visible in shadowgraphs for a range of tip Mach number of 0.38 to 0.60. The effect of the angle of attack is substantial. At an angle of attack greater than 8 degrees, the visibility of the vortex core is significant even at relatively low tip Mach numbers. The theoretical analysis of the sensitivity is carried out for a rotating blade. This analysis demonstrates that the sensitivity decreases with increasing dimensionless core radius and increases with increasing tip Mach number. The threshold value of the sensitivity is found to be 0.0015, below which the vortex core is not visible and above which it is visible. The effect of the optical path length is also discussed. Based on this investigation, it is concluded that the application of this wide-field shadowgraph technique to a large wind tunnel test should be feasible. In addition, two simultaneous shadowgraph views would allow three-dimensional reconstruction of vortex trajectories.

Formaldehyde sensor based on Ni-doped tetrapod-shaped ZnO nanopowder induced by external magnetic field

NASA Astrophysics Data System (ADS)

Bai, Zikui; Xie, Changsheng; Hu, Mulin; Zhang, Shunping

2008-12-01

The sensors based on Ni-doped ZnO nanopowder with tetrapod-shape (T-ZnO) were fabricated by screen-printing technique with external magnetic field in different direction. The morphologies and crystal structures of the thick film were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. Gas-sensing property of sensors responded to 100 ppm formaldehyde was also detected. The results show that the direction of magnetic field has crucial effect on the sensor sensitivity. The sensors based on 5 wt% Ni-doped T-ZnO induced by magnetic field in parallel direction to the thick film surface, has the optimization sensitivity, the shortest response and recovery time, which are 10.6, 16 and 15 s, respectively. The magnetic-field induction model and the gas-sensing mechanism of the Ni-doped T-ZnO are proposed.

Gene and Protein Expression following Exposure to Radiofrequency Fields from Mobile Phones

PubMed Central

Vanderstraeten, Jacques; Verschaeve, Luc

2008-01-01

Background Since 1999, several articles have been published on genome-wide and/or proteome-wide response after exposure to radiofrequency (RF) fields whose signal and intensities were similar to or typical of those of currently used mobile telephones. These studies were performed using powerful high-throughput screening techniques (HTSTs) of transcriptomics and/or proteomics, which allow for the simultaneous screening of the expression of thousands of genes or proteins. Objectives We reviewed these HTST-based studies and compared the results with currently accepted concepts about the effects of RF fields on gene expression. In this article we also discuss these last in light of the recent concept of microwave-assisted chemistry. Discussion To date, the results of HTST-based studies of transcriptomics and/or proteomics after exposure to RF fields relevant to human exposure are still inconclusive, as most of the positive reports are flawed by methodologic imperfections or shortcomings. In addition, when positive findings were reported, no precise response pattern could be identified in a reproducible way. In particular, results from HTST studies tend to exclude the role of a cell stressor for exposure to RF fields at nonthermal intensities. However, on the basis of lessons from microwave-assisted chemistry, we can assume that RF fields might affect heat-sensitive gene or protein expression to an extent larger than would be predicted from temperature change only. But in all likelihood, this would concern intensities higher than those relevant to usual human exposure. Conclusions The precise role of transcriptomics and proteomics in the screening of bioeffects from exposure to RF fields from mobile phones is still uncertain in view of the lack of positively identified phenotypic change and the lack of theoretical, as well as experimental, arguments for specific gene and/or protein response patterns after this kind of exposure. PMID:18795152

Induced pluripotent stem cells for regenerative cardiovascular therapies and biomedical discovery.

PubMed

Nsair, Ali; MacLellan, W Robb

2011-04-30

The discovery of induced pluripotent stem cells (iPSC) has, in the short time since their discovery, revolutionized the field of stem cell biology. This technology allows the generation of a virtually unlimited supply of cells with pluripotent potential similar to that of embryonic stem cells (ESC). However, in contrast to ESC, iPSC are not subject to the same ethical concerns and can be easily generated from living individuals. For the first time, patient-specific iPSC can be generated and offer a supply of genetically identical cells that can be differentiated into all somatic cell types for potential use in regenerative therapies or drug screening and testing. As the techniques for generation of iPSC lines are constantly evolving, new uses for human iPSC are emerging from in-vitro disease modeling to high throughput drug discovery and screening. This technology promises to revolutionize the field of medicine and offers new hope for understanding and treatment of numerous diseases. Copyright © 2011 Elsevier B.V. All rights reserved.

[Clinical application of mass spectrometry in the pediatric field: current topics].

PubMed

Yamaguchi, Seiji

2013-09-01

Mass spectrometry, including tandem mass spectrometry (MS/MS) and gas chromatography-mass spectrometry (GC/MS), is becoming prominent in the diagnosis of metabolic disorders in the pediatric field. It enables biochemical diagnosis of metabolic disorders from the metabolic profiles obtained by MS/MS and/or GC/MS. In neonatal mass screening for inherited metabolic disease (IMD) using MS/MS, amino acids and acylcarnitines on dried blood spots are analyzed. The target diseases include amino acidemia, urea cycle disorder, organic acidemia, and fatty acid oxidation disorder. In the MS/MS screening, organic acid analysis using GC/MS is required for differential and/or definite diagnosis of the IMDs. GC/MS data processing, however, is difficult, and metabolic diagnosis often requires the necessary skills and expertize. We developed an automated system of GC/MS data processing and autodiagnosis, and the biochemical diagnosis using GC/MS became markedly easier and user-friendly. Mass spectrometric techniques will expand from research laboratories to clinical laboratories in the near future.

Adaptive photoacoustic imaging using the Mallart-Fink focusing factor

NASA Astrophysics Data System (ADS)

Li, Meng-Lin

2008-02-01

Focusing errors caused by sound velocity heterogeneities widen the mainlobe and elevate the sidelobes, thus degrading both spatial and contrast resolutions in photoacoustic imaging. We propose an adaptive array-based photoacoustic imaging technique that uses the Mallart-Fink (MF) focusing factor weighting to reduce the effect of such focusing errors. The definition of the MF focusing factor indicates that the MF focusing factor at the main lobe of the point-spread function is high (close to 1, without speckle noise being present, which is the case in photoacoustic imaging), whereas it is low at the sidelobes. Based on this property, the elevated sidelobes caused by sound velocity heterogeneities in the tissue can be suppressed after being multiplied by the corresponding map of the MF focusing factor on each imaging point; thus the focusing quality can be improved. This technique makes no assumption of sources of focusing errors and directly suppresses the unwanted sidelobe contributions. Numerical experiments with near field phase screen and displaced phase screen models were performed here to verify the proposed adaptive weighting technique. The effect of the signal-to-noise ratio on the MF focusing factor is also discussed.

Recent advances in stable isotope labeling based techniques for proteome relative quantification.

PubMed

Zhou, Yuan; Shan, Yichu; Zhang, Lihua; Zhang, Yukui

2014-10-24

The large scale relative quantification of all proteins expressed in biological samples under different states is of great importance for discovering proteins with important biological functions, as well as screening disease related biomarkers and drug targets. Therefore, the accurate quantification of proteins at proteome level has become one of the key issues in protein science. Herein, the recent advances in stable isotope labeling based techniques for proteome relative quantification were reviewed, from the aspects of metabolic labeling, chemical labeling and enzyme-catalyzed labeling. Furthermore, the future research direction in this field was prospected. Copyright © 2014 Elsevier B.V. All rights reserved.

Newborn bloodspot screening in the UK--past, present and future.

PubMed

Downing, Melanie; Pollitt, Rodney

2008-01-01

Screening newborn babies for inherited metabolic disease began in the UK in the late 1950s with the 'nappy test' for phenylketonuria. In 1969 the Department of Health recommended changing to bloodspot screening using the techniques developed in the USA by Robert Guthrie and his associates. Bloodspot screening for various other disorders (galactosaemia, maple syrup urine disease, homocystinuria, cystic fibrosis and others) was introduced on a patchy local basis but, until 2000, the only additional disorder officially recommended was congenital hypothyroidism. Screening for haemoglobinopathies received official support in 2000 and for cystic fibrosis in 2001 though implementation was slow, particularly for the latter. Both these screens have raised difficult issues relating to genetic privacy and the detection of carrier status in children. During the last decade screening has become increasingly subject to central control. Though a more consistent and systematic approach was clearly needed, this has undoubtedly slowed the rate of innovation. In particular the UK has lagged behind many other European countries in the application of tandem mass spectrometry (MS-MS) though, following a major pilot study, screening for medium-chain acyl-CoA dehydrogenase deficiency is now in the process of introduction. Attempts to codify clinical and laboratory procedures have also proved controversial, highlighting marked differences in practice in various parts of the country and the difficulty of rationalizing these within a practicable and scientifically justified framework. Notwithstanding this, there are many positive developments and newborn screening remains a stimulating and rewarding field in which to work.

Reliability of the Tuck Jump Injury Risk Screening Assessment in Elite Male Youth Soccer Players.

PubMed

Read, Paul J; Oliver, Jon L; de Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S

2016-06-01

Read, PJ, Oliver, JL, de Ste Croix, MBA, Myer, GD, and Lloyd, RS. Reliability of the tuck jump injury risk screening assessment in elite male youth soccer players. J Strength Cond Res 30(6): 1510-1516, 2016-Altered neuromuscular control has been suggested as a mechanism for injury in soccer players. Ligamentous injuries most often occur during dynamic movements, such as decelerations from jump-landing maneuvers where high-risk movement patterns are present. The assessment of kinematic variables during jump-landing tasks as part of a preparticipation screen is useful in the identification of injury risk. An example of a field-based screening tool is the repeated tuck jump assessment. The purpose of this study was to analyze the within-subject variation of the tuck jump screening assessment in elite male youth soccer players. Twenty-five pre-peak height velocity (PHV) and 25 post-PHV elite male youth soccer players from the academy of a professional English soccer club completed the assessment. A test-retest design was used to explore the within-subject intersession reliability. Technique was graded retrospectively against the 10-point criteria set out in the screening protocol using two-dimensional video cameras. The typical error range reported for tuck jump total score (0.90-1.01 in pre-PHV and post-PHV players respectively) was considered acceptable. When each criteria was analyzed individually, kappa coefficient determined that knee valgus was the only criterion to reach substantial agreement across the two test sessions for both groups. The results of this study suggest that although tuck jump total score may be reliably assessed in elite male youth soccer players, caution should be applied in solely interpreting the composite score due to the high within-subject variation in a number of the individual criteria. Knee valgus may be reliably used to screen elite youth male soccer players for this plyometric technique error and for test-retest comparison.

Unsupervised segmentation of lungs from chest radiographs

NASA Astrophysics Data System (ADS)

Ghosh, Payel; Antani, Sameer K.; Long, L. Rodney; Thoma, George R.

2012-03-01

This paper describes our preliminary investigations for deriving and characterizing coarse-level textural regions present in the lung field on chest radiographs using unsupervised grow-cut (UGC), a cellular automaton based unsupervised segmentation technique. The segmentation has been performed on a publicly available data set of chest radiographs. The algorithm is useful for this application because it automatically converges to a natural segmentation of the image from random seed points using low-level image features such as pixel intensity values and texture features. Our goal is to develop a portable screening system for early detection of lung diseases for use in remote areas in developing countries. This involves developing automated algorithms for screening x-rays as normal/abnormal with a high degree of sensitivity, and identifying lung disease patterns on chest x-rays. Automatically deriving and quantitatively characterizing abnormal regions present in the lung field is the first step toward this goal. Therefore, region-based features such as geometrical and pixel-value measurements were derived from the segmented lung fields. In the future, feature selection and classification will be performed to identify pathological conditions such as pulmonary tuberculosis on chest radiographs. Shape-based features will also be incorporated to account for occlusions of the lung field and by other anatomical structures such as the heart and diaphragm.

Apparel Research Network (ARN); Apparel Order Processing Module (AOPM): Field User Manual, Version 1

DTIC Science & Technology

1997-09-30

changes. Cancel Button Closes the Site Information Screen, abandoning changes. APPAREL ORDER PROCESSING MODULE FIELD USER MANUAL Ordering Official...on the Ordering Official Information Screen. APPAREL ORDER PROCESSING MODULE FIELD USER MANUAL Ordering Official Information Screen (Jjj

Analysis of SNP rs16754 of WT1 gene in a series of de novo acute myeloid leukemia patients.

PubMed

Luna, Irene; Such, Esperanza; Cervera, Jose; Barragán, Eva; Jiménez-Velasco, Antonio; Dolz, Sandra; Ibáñez, Mariam; Gómez-Seguí, Inés; López-Pavía, María; Llop, Marta; Fuster, Óscar; Oltra, Silvestre; Moscardó, Federico; Martínez-Cuadrón, David; Senent, M Leonor; Gascón, Adriana; Montesinos, Pau; Martín, Guillermo; Bolufer, Pascual; Sanz, Miguel A

2012-12-01

The single nucleotide polymorphism (SNP) rs16754 of the WT1 gene has been previously described as a possible prognostic marker in normal karyotype acute myeloid leukemia (AML) patients. Nevertheless, the findings in this field are not always reproducible in different series. One hundred and seventy-five adult de novo AML patients were screened with two different methods for the detection of SNP rs16754: high-resolution melting (HRM) and FRET hybridization probes. Direct sequencing was used to validate both techniques. The SNP was detected in 52 out of 175 patients (30 %), both by HRM and hybridization probes. Direct sequencing confirmed that every positive sample in the screening methods had a variation in the DNA sequence. Patients with the wild-type genotype (WT1(AA)) for the SNP rs16754 were significantly younger than those with the heterozygous WT1(AG) genotype. No other difference was observed for baseline characteristic or outcome between patients with or without the SNP. Both techniques are equally reliable and reproducible as screening methods for the detection of the SNP rs16754, allowing for the selection of those samples that will need to be sequenced. We were unable to confirm the suggested favorable outcome of SNP rs16754 in de novo AML.

Criticality accident dosimetry with ESR spectroscopy.

PubMed

d'Errico, F; Fattibene, P; Onori, S; Pantaloni, M

1996-01-01

The suitability of the ESR alanine and sugar detectors for criticality accident dosimetry was experimentally investigated during an intercomparison of dosimetry techniques. Tests were performed irradiating detectors both free-in-air and on-phantom during controlled critcality excursions at the SILENE reactor in Valduc, France. Several grays of absorbed dose were imparted in neutron gamma-ray fields of various relative intensities and spectral distributions. Analysed results confirmed the potential of these systems which can immediately provide an acute dose assessment with an average underestimate of 30%in the various fields. This performance allows for the screening of severely exposed individuals and meets the IAEA recommendations on the early estimate of accident absorbed doses.

Human iPSC-derived cardiomyocytes and tissue engineering strategies for disease modeling and drug screening

PubMed Central

Smith, Alec S.T.; Macadangdang, Jesse; Leung, Winnie; Laflamme, Michael A.; Kim, Deok-Ho

2016-01-01

Improved methodologies for modeling cardiac disease phenotypes and accurately screening the efficacy and toxicity of potential therapeutic compounds are actively being sought to advance drug development and improve disease modeling capabilities. To that end, much recent effort has been devoted to the development of novel engineered biomimetic cardiac tissue platforms that accurately recapitulate the structure and function of the human myocardium. Within the field of cardiac engineering, induced pluripotent stem cells (iPSCs) are an exciting tool that offer the potential to advance the current state of the art, as they are derived from somatic cells, enabling the development of personalized medical strategies and patient specific disease models. Here we review different aspects of iPSC-based cardiac engineering technologies. We highlight methods for producing iPSC-derived cardiomyocytes (iPSC-CMs) and discuss their application to compound efficacy/toxicity screening and in vitro modeling of prevalent cardiac diseases. Special attention is paid to the application of micro- and nano-engineering techniques for the development of novel iPSC-CM based platforms and their potential to advance current preclinical screening modalities. PMID:28007615

Preparation of a YAG:Ce phosphor glass by screen-printing technology and its application in LED packaging.

PubMed

Yang, Liang; Chen, Mingxiang; Lv, Zhicheng; Wang, Simin; Liu, Xiaogang; Liu, Sheng

2013-07-01

A simple and practical method for preparing phosphor glass is proposed. Phosphor distribution and element analysis are investigated by optical microscope and field emission scanning electron microscope (FE-SEM). The phosphor particles dispersed in the matrix are vividly observed, and their distributions are uniform. Spectrum distribution and color coordinates dependent on the thickness of the screen-printed phosphor layer coupled with a blue light emitting diode (LED) chip are studied. The luminous efficacy of the 75 μm printed phosphor-layer phosphor glass packaged white LED is 81.24 lm/W at 350 mA. This study opens up many possibilities for applications using the phosphor glass on a selected chip in which emission is well absorbed by all phosphors. The screen-printing technique also offers possibilities for the design and engineering of complex phosphor layers on glass substrates. Phosphor screen-printing technology allows the realization of high stability and thermal conductivity for the phosphor layer. This phosphor glass method provides many possibilities for LED packing, including thin-film flip chip and remote phosphor technology.

Screening Effect of Plasma Flow on RMP Penetration in EXTRAP T2R

NASA Astrophysics Data System (ADS)

Frassinetti, Lorenzo; Olofsson, Erik; Brunsell, Per; Menmuir, Sheena; Drake, James

2011-10-01

The penetration of resonant magnetic perturbations (RMP) can be screened by plasma flow and the understanding of this phenomenon is important for ELM mitigation techniques. This work studies the screening effect in EXTRAP T2R. EXTRAP T2R is equipped with a feedback system able to suppress all error fields and to produce one or more external perturbations in a controlled fashion. The EXTRAP T2R feedback system is used to generate a RMP that interacts with the dynamics of its corresponding tearing mode (TM). The level of RMP penetration is quantified by analyzing the RMP effect on the TM amplitude and velocity. To study the screening effect, the flow is changed by applying a second perturbation that is non resonant (non-RMP). This produces the flow reduction without perturbing significantly the other parameters. By modifying the amplitude of the non-RMP, an experimental study of the flow effect on the RMP penetration is performed. Experimental results are compared with the model described in [Fitzpatrick R et al., Phys. Plasmas 8, 4489 (2001)].

Virtual Ligand Screening Using PL-PatchSurfer2, a Molecular Surface-Based Protein-Ligand Docking Method.

PubMed

Shin, Woong-Hee; Kihara, Daisuke

2018-01-01

Virtual screening is a computational technique for predicting a potent binding compound for a receptor protein from a ligand library. It has been a widely used in the drug discovery field to reduce the efforts of medicinal chemists to find hit compounds by experiments.Here, we introduce our novel structure-based virtual screening program, PL-PatchSurfer, which uses molecular surface representation with the three-dimensional Zernike descriptors, which is an effective mathematical representation for identifying physicochemical complementarities between local surfaces of a target protein and a ligand. The advantage of the surface-patch description is its tolerance on a receptor and compound structure variation. PL-PatchSurfer2 achieves higher accuracy on apo form and computationally modeled receptor structures than conventional structure-based virtual screening programs. Thus, PL-PatchSurfer2 opens up an opportunity for targets that do not have their crystal structures. The program is provided as a stand-alone program at http://kiharalab.org/plps2 . We also provide files for two ligand libraries, ChEMBL and ZINC Drug-like.

High-throughput phenotyping (HTP) identifies seedling root traits linked to variation in seed yield and nutrient capture in field-grown oilseed rape (Brassica napus L.)

PubMed Central

Thomas, C. L.; Graham, N. S.; Hayden, R.; Meacham, M. C.; Neugebauer, K.; Nightingale, M.; Dupuy, L. X.; Hammond, J. P.; White, P. J.; Broadley, M. R.

2016-01-01

Background and Aims Root traits can be selected for crop improvement. Techniques such as soil excavations can be used to screen root traits in the field, but are limited to genotypes that are well-adapted to field conditions. The aim of this study was to compare a low-cost, high-throughput root phenotyping (HTP) technique in a controlled environment with field performance, using oilseed rape (OSR; Brassica napus) varieties. Methods Primary root length (PRL), lateral root length and lateral root density (LRD) were measured on 14-d-old seedlings of elite OSR varieties (n = 32) using a ‘pouch and wick’ HTP system (∼40 replicates). Six field experiments were conducted using the same varieties at two UK sites each year for 3 years. Plants were excavated at the 6- to 8-leaf stage for general vigour assessments of roots and shoots in all six experiments, and final seed yield was determined. Leaves were sampled for mineral composition from one of the field experiments. Key Results Seedling PRL in the HTP system correlated with seed yield in four out of six (r = 0·50, 0·50, 0·33, 0·49; P < 0·05) and with emergence in three out of five (r = 0·59, 0·22, 0·49; P < 0·05) field experiments. Seedling LRD correlated positively with leaf concentrations of some minerals, e.g. calcium (r = 0·46; P < 0·01) and zinc (r = 0·58; P < 0·001), but did not correlate with emergence, general early vigour or yield in the field. Conclusions Associations between PRL and field performance are generally related to early vigour. These root traits might therefore be of limited additional selection value, given that vigour can be measured easily on shoots/canopies. In contrast, LRD cannot be assessed easily in the field and, if LRD can improve nutrient uptake, then it may be possible to use HTP systems to screen this trait in both elite and more genetically diverse, non-field-adapted OSR. PMID:27052342

Mass spectrometry for fragment screening.

PubMed

Chan, Daniel Shiu-Hin; Whitehouse, Andrew J; Coyne, Anthony G; Abell, Chris

2017-11-08

Fragment-based approaches in chemical biology and drug discovery have been widely adopted worldwide in both academia and industry. Fragment hits tend to interact weakly with their targets, necessitating the use of sensitive biophysical techniques to detect their binding. Common fragment screening techniques include differential scanning fluorimetry (DSF) and ligand-observed NMR. Validation and characterization of hits is usually performed using a combination of protein-observed NMR, isothermal titration calorimetry (ITC) and X-ray crystallography. In this context, MS is a relatively underutilized technique in fragment screening for drug discovery. MS-based techniques have the advantage of high sensitivity, low sample consumption and being label-free. This review highlights recent examples of the emerging use of MS-based techniques in fragment screening. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Application of Functional Use Predictions to Aid in Structure ...

EPA Pesticide Factsheets

Humans are potentially exposed to thousands of anthropogenic chemicals in commerce. Recent work has shown that the bulk of this exposure may occur in near-field indoor environments (e.g., home, school, work, etc.). Advances in suspect screening analyses (SSA) now allow an improved understanding of the chemicals present in these environments. However, due to the nature of suspect screening techniques, investigators are often left with chemical formula predictions, with the possibility of many chemical structures matching to each formula. Here, newly developed quantitative structure-use relationship (QSUR) models are used to identify potential exposure sources for candidate structures. Previously, a suspect screening workflow was introduced and applied to house dust samples collected from the U.S. Department of Housing and Urban Development’s American Healthy Homes Survey (AHHS) [Rager, et al., Env. Int. 88 (2016)]. This workflow utilized the US EPA’s Distributed Structure-Searchable Toxicity (DSSTox) Database to link identified molecular features to molecular formulas, and ultimately chemical structures. Multiple QSUR models were applied to support the evaluation of candidate structures. These QSURs predict the likelihood of a chemical having a functional use commonly associated with consumer products having near-field use. For 3,228 structures identified as possible chemicals in AHHS house dust samples, we were able to obtain the required descriptors to appl

When fragments link: a bibliometric perspective on the development of fragment-based drug discovery.

PubMed

Romasanta, Angelo K S; van der Sijde, Peter; Hellsten, Iina; Hubbard, Roderick E; Keseru, Gyorgy M; van Muijlwijk-Koezen, Jacqueline; de Esch, Iwan J P

2018-05-05

Fragment-based drug discovery (FBDD) is a highly interdisciplinary field, rich in ideas integrated from pharmaceutical sciences, chemistry, biology, and physics, among others. To enrich our understanding of the development of the field, we used bibliometric techniques to analyze 3642 publications in FBDD, complementing accounts by key practitioners. Mapping its core papers, we found the transfer of knowledge from academia to industry. Co-authorship analysis showed that university-industry collaboration has grown over time. Moreover, we show how ideas from other scientific disciplines have been integrated into the FBDD paradigm. Keyword analysis showed that the field is organized into four interconnected practices: library design, fragment screening, computational methods, and optimization. This study highlights the importance of interactions among various individuals and institutions from diverse disciplines in newly emerging scientific fields. Copyright © 2018. Published by Elsevier Ltd.

Site characterization and analysis penetrometer system

NASA Astrophysics Data System (ADS)

Heath, Jeff

1995-04-01

The site characterization and analysis penetrometer system (SCAPS) with laser induced fluorescence (LIF) sensors is being demonstrated as a quick field screening technique to determine the physical and chemical characteristics of subsurface soil and contaminants at hazardous waste sites SCAPS is a collaborative development effort of the Navy, Army, and Air Force under the Tri-Service SCAPS Program. The current SCAPS configuration is designed to quickly and cost-effectively distinguish areas contaminated with petroleum products (hydrocarbons) from unaffected areas.

Metals in boat paint fragments from slipways, repair facilities and abandoned vessels: an evaluation using field portable XRF.

PubMed

Turner, Andrew; Comber, Sean; Rees, Aldous B; Gkiokas, Dimitrios; Solman, Kevin

2015-01-01

Paint flaking off abandoned vessels or generated during boat repair is hazardous to human health and wildlife. In this study, a means of screening paint fragments using a field portable-X-ray fluorescence (FP-XRF) spectrometer is described. The technique is capable of delivering rapid, surficial measurements of Ba, Cu, Pb and Zn down to concentrations less than 150 μg g(-1), and Sn and Cr to concentrations of a few hundred μg g(-1). Application of the technique to fragments collected from slipways, yards, hardstandings, abandoned boats and ships undergoing maintenance throughout the EU reveal highly variable concentrations of metals among samples from the same environment or from the same region of a given boat; in many cases, variability is also evident in different areas or on different surfaces of the same fragment. Of particular concern are elevated concentrations of substances that have been restricted or banned (e.g. Sn, an indicator of organotin, and up to concentrations of 40,000 μg g(-1), and Pb up to concentrations of 200,000 μg g(-1)). Although FP-XRF can rapidly screen samples whose composition and origin are unknown and can assist in instantaneous decision making, a full risk assessment will rely on additional analyses of the precise species (including organo-forms) of the metals present. Copyright © 2014 Elsevier B.V. All rights reserved.

Drug and bioactive molecule screening based on a bioelectrical impedance cell culture platform

PubMed Central

Ramasamy, Sakthivel; Bennet, Devasier; Kim, Sanghyo

2014-01-01

This review will present a brief discussion on the recent advancements of bioelectrical impedance cell-based biosensors, especially the electric cell-substrate impedance sensing (ECIS) system for screening of various bioactive molecules. The different technical integrations of various chip types, working principles, measurement systems, and applications for drug targeting of molecules in cells are highlighted in this paper. Screening of bioactive molecules based on electric cell-substrate impedance sensing is a trial-and-error process toward the development of therapeutically active agents for drug discovery and therapeutics. In general, bioactive molecule screening can be used to identify active molecular targets for various diseases and toxicity at the cellular level with nanoscale resolution. In the innovation and screening of new drugs or bioactive molecules, the activeness, the efficacy of the compound, and safety in biological systems are the main concerns on which determination of drug candidates is based. Further, drug discovery and screening of compounds are often performed in cell-based test systems in order to reduce costs and save time. Moreover, this system can provide more relevant results in in vivo studies, as well as high-throughput drug screening for various diseases during the early stages of drug discovery. Recently, MEMS technologies and integration with image detection techniques have been employed successfully. These new technologies and their possible ongoing transformations are addressed. Select reports are outlined, and not all the work that has been performed in the field of drug screening and development is covered. PMID:25525360

A comparative analysis of conventional cytopreparatory and liquid based cytological techniques (Sure Path) in evaluation of serous effusion fluids.

PubMed

Dadhich, Hrishikesh; Toi, Pampa Ch; Siddaraju, Neelaiah; Sevvanthi, Kalidas

2016-11-01

Clinically, detection of malignant cells in serous body fluids is critical, as their presence implies the upstaging of the disease. Cytology of body cavity fluids serves as an important tool when other diagnostic tests cannot be performed. In most laboratories, currently, the effusion fluid samples are analysed chiefly by the conventional cytopreparatory (CCP) technique. Although, there are several studies comparing the liquid-based cytology (LBC), with CCP technique in the field of cervicovaginal cytology; the literature on such comparison with respect to serous body fluid examination is sparse. One hundred samples of serous body fluids were processed by both CCP and LBC techniques. Slides prepared by these techniques were studied using six parameters. A comparative analysis of the advantages and disadvantages of the techniques in detection of malignant cells was carried out with appropriate statistical tests. The samples comprised 52 pleural, 44 peritoneal and four pericardial fluids. No statistically significant difference was noted with respect to cellularity (P values = 0.22), cell distribution (P values = 0.39) and diagnosis of malignancy (P values = 0.20). As for the remaining parameters, LBC provided statistically significant clearer smear background (P values < 0.0001) and shorter screening time (P values < 0.0001), while CPP technique provided a significantly better staining quality (P values 0.01) and sharper cytomorphologic features (P values 0.05). Although, a reduced screening time and clearer smear background are the two major advantages of LBC; the CCP technique provides the better staining quality with sharper cytomorphologic features which is more critical from the cytologic interpretation point of view. Diagn. Cytopathol. 2016;44:874-879. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Imaging with terahertz radiation

NASA Astrophysics Data System (ADS)

Chan, Wai Lam; Deibel, Jason; Mittleman, Daniel M.

2007-08-01

Within the last several years, the field of terahertz science and technology has changed dramatically. Many new advances in the technology for generation, manipulation, and detection of terahertz radiation have revolutionized the field. Much of this interest has been inspired by the promise of valuable new applications for terahertz imaging and sensing. Among a long list of proposed uses, one finds compelling needs such as security screening and quality control, as well as whimsical notions such as counting the almonds in a bar of chocolate. This list has grown in parallel with the development of new technologies and new paradigms for imaging and sensing. Many of these proposed applications exploit the unique capabilities of terahertz radiation to penetrate common packaging materials and provide spectroscopic information about the materials within. Several of the techniques used for terahertz imaging have been borrowed from other, more well established fields such as x-ray computed tomography and synthetic aperture radar. Others have been developed exclusively for the terahertz field, and have no analogies in other portions of the spectrum. This review provides a comprehensive description of the various techniques which have been employed for terahertz image formation, as well as discussing numerous examples which illustrate the many exciting potential uses for these emerging technologies.

Rapid Separation of Bacteria from Blood—Review and Outlook

PubMed Central

Alizadeh, Mahsa; Husseini, Ghaleb A.; McClellan, Daniel S.; Buchanan, Clara M.; Bledsoe, Colin G.; Robison, Richard A.; Blanco, Rae; Roeder, Beverly L.; Melville, Madison; Hunter, Alex K.

2017-01-01

The high morbidity and mortality rate of bloodstream infections involving antibiotic-resistant bacteria necessitate a rapid identification of the infectious organism and its resistance profile. Traditional methods based on culturing the blood typically require at least 24 h, and genetic amplification by PCR in the presence of blood components has been problematic. The rapid separation of bacteria from blood would facilitate their genetic identification by PCR or other methods so that the proper antibiotic regimen can quickly be selected for the septic patient. Microfluidic systems that separate bacteria from whole blood have been developed, but these are designed to process only microliter quantities of whole blood or only highly diluted blood. However, symptoms of clinical blood infections can be manifest with bacterial burdens perhaps as low as 10 CFU/mL, and thus milliliter quantities of blood must be processed to collect enough bacteria for reliable genetic analysis. This review considers the advantages and shortcomings of various methods to separate bacteria from blood, with emphasis on techniques that can be done in less than 10 min on milliliter-quantities of whole blood. These techniques include filtration, screening, centrifugation, sedimentation, hydrodynamic focusing, chemical capture on surfaces or beads, field-flow fractionation, and dielectrophoresis. Techniques with the most promise include screening, sedimentation, and magnetic bead capture, as they allow large quantities of blood to be processed quickly. Some microfluidic techniques can be scaled up. PMID:27160415

Electric Field Screening with Backflow at Pulsar Polar Cap

NASA Astrophysics Data System (ADS)

Kisaka, Shota; Asano, Katsuaki; Terasawa, Toshio

2016-09-01

Recent γ-ray observations suggest that particle acceleration occurs at the outer region of the pulsar magnetosphere. The magnetic field lines in the outer acceleration region (OAR) are connected to the neutron star surface (NSS). If copious electron-positron pairs are produced near the NSS, such pairs flow into the OAR and screen the electric field there. To activate the OAR, the electromagnetic cascade due to the electric field near the NSS should be suppressed. However, since a return current is expected along the field lines through the OAR, the outflow extracted from the NSS alone cannot screen the electric field just above the NSS. In this paper, we analytically and numerically study the electric field screening at the NSS, taking into account the effects of the backflowing particles from the OAR. In certain limited cases, the electric field is screened without significant pair cascade if only ultra-relativistic particles (γ \\gg 1) flow back to the NSS. On the other hand, if electron-positron pairs with a significant number density and mildly relativistic temperature, expected to distribute in a wide region of the magnetosphere, flow back to the NSS, these particles adjust the current and charge densities so that the electric field can be screened without pair cascade. We obtain the condition needed for the number density of particles to screen the electric field at the NSS. We also find that in the ion-extracted case from the NSS, bunches of particles are ejected to the outer region quasi-periodically, which is a possible mechanism of observed radio emission.

High definition infrared chemical imaging of colorectal tissue using a Spero QCL microscope.

PubMed

Bird, B; Rowlette, J

2017-04-10

Mid-infrared microscopy has become a key technique in the field of biomedical science and spectroscopy. This label-free, non-destructive technique permits the visualisation of a wide range of intrinsic biochemical markers in tissues, cells and biofluids by detection of the vibrational modes of the constituent molecules. Together, infrared microscopy and chemometrics is a widely accepted method that can distinguish healthy and diseased states with high accuracy. However, despite the exponential growth of the field and its research world-wide, several barriers currently exist for its full translation into the clinical sphere, namely sample throughput and data management. The advent and incorporation of quantum cascade lasers (QCLs) into infrared microscopes could help propel the field over these remaining hurdles. Such systems offer several advantages over their FT-IR counterparts, a simpler instrument architecture, improved photon flux, use of room temperature camera systems, and the flexibility of a tunable illumination source. In this current study we explore the use of a QCL infrared microscope to produce high definition, high throughput chemical images useful for the screening of biopsied colorectal tissue.

Apparel Research Network (ARN) Apparel Order Processing Module (AOPM). Application Program for Management of Special Measurement Clothing Orders

DTIC Science & Technology

1997-09-30

Screen, abandoning changes. APPAREL ORDER PROCESSING MODULE FIELD USER MANUAL Ordering Official Screens The Ordering Official Screens are provided for...currendy selected Ordering Official will appear on the Ordering Official Information Screen. APPAREL ORDER PROCESSING MODULE FIELD USER MANUAL Ordering Official

Army medical laboratory telemedicine: role of mass spectrometry in telediagnosis for chemical and biological defense.

PubMed

Smith, J R; Shih, M L; Price, E O; Platoff, G E; Schlager, J J

2001-12-01

An army medical field laboratory presently has the capability of performing standard protocols developed at the US Army Medical Research Institute of Chemical Defense for verification of nerve agent or sulfur mustard exposure. The protocols analyze hydrolysis products of chemical warfare agents using gas chromatography/mass spectrometry. Additionally, chemical warfare agents can produce alkylated or phosphorylated proteins following human exposure that have long biological half-lives and can be used as diagnostic biomarkers of chemical agent exposure. An analytical technique known as matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS) currently is being examined for its potential to analyze these biomarkers. The technique is capable of detecting large biomolecules and modifications made to them. Its fast analysis time makes MALDI-TOF/MS technology suitable for screening casualties from chemical or biological attacks. Basic operation requires minimal training and the instrument has the potential to become field-portable. The limitation of the technique is that the generated data may require considerable expertise from knowledgeable personnel for consultation to ensure correct interpretation. The interaction between research scientists and field personnel in the acquisition of data and its interpretation via advanced digital telecommunication technologies can enhance rapid diagnosis and subsequently improve patient care in remote areas. Copyright 2001 John Wiley & Sons, Ltd.

Affordable proteomics: the two-hybrid systems.

PubMed

Gillespie, Marc

2003-06-01

Numerous proteomic methodologies exist, but most require a heavy investment in expertise and technology. This puts these approaches out of reach for many laboratories and small companies, rarely allowing proteomics to be used as a pilot approach for biomarker or target identification. Two proteomic approaches, 2D gel electrophoresis and the two-hybrid systems, are currently available to most researchers. The two-hybrid systems, though accommodating to large-scale experiments, were originally designed as practical screens, that by comparison to current proteomics tools were small-scale, affordable and technically feasible. The screens rapidly generated data, identifying protein interactions that were previously uncharacterized. The foundation for a two-hybrid proteomic investigation can be purchased as separate kits from a number of companies. The true power of the technique lies not in its affordability, but rather in its portability. The two-hybrid system puts proteomics back into laboratories where the output of the screens can be evaluated by researchers with experience in the particular fields of basic research, cancer biology, toxicology or drug development.

An oppositely charged insect exclusion screen with gap-free multiple electric fields

NASA Astrophysics Data System (ADS)

Matsuda, Yoshinori; Kakutani, Koji; Nonomura, Teruo; Kimbara, Junji; Kusakari, Shin-ichi; Osamura, Kazumi; Toyoda, Hideyoshi

2012-12-01

An electric field screen was constructed to examine insect attraction mechanisms in multiple electric fields generated inside the screen. The screen consisted of two parallel insulated conductor wires (ICWs) charged with equal but opposite voltages and two separate grounded nets connected to each other and placed on each side of the ICW layer. Insects released inside the fields were charged either positively or negatively as a result of electricity flow from or to the insect, respectively. The force generated between the charged insects and opposite ICW charges was sufficient to capture all insects.

Retinal Imaging Techniques for Diabetic Retinopathy Screening

PubMed Central

Goh, James Kang Hao; Cheung, Carol Y.; Sim, Shaun Sebastian; Tan, Pok Chien; Tan, Gavin Siew Wei; Wong, Tien Yin

2016-01-01

Due to the increasing prevalence of diabetes mellitus, demand for diabetic retinopathy (DR) screening platforms is steeply increasing. Early detection and treatment of DR are key public health interventions that can greatly reduce the likelihood of vision loss. Current DR screening programs typically employ retinal fundus photography, which relies on skilled readers for manual DR assessment. However, this is labor-intensive and suffers from inconsistency across sites. Hence, there has been a recent proliferation of automated retinal image analysis software that may potentially alleviate this burden cost-effectively. Furthermore, current screening programs based on 2-dimensional fundus photography do not effectively screen for diabetic macular edema (DME). Optical coherence tomography is becoming increasingly recognized as the reference standard for DME assessment and can potentially provide a cost-effective solution for improving DME detection in large-scale DR screening programs. Current screening techniques are also unable to image the peripheral retina and require pharmacological pupil dilation; ultra-widefield imaging and confocal scanning laser ophthalmoscopy, which address these drawbacks, possess great potential. In this review, we summarize the current DR screening methods using various retinal imaging techniques, and also outline future possibilities. Advances in retinal imaging techniques can potentially transform the management of patients with diabetes, providing savings in health care costs and resources. PMID:26830491

Retinal Imaging Techniques for Diabetic Retinopathy Screening.

PubMed

Goh, James Kang Hao; Cheung, Carol Y; Sim, Shaun Sebastian; Tan, Pok Chien; Tan, Gavin Siew Wei; Wong, Tien Yin

2016-02-01

Due to the increasing prevalence of diabetes mellitus, demand for diabetic retinopathy (DR) screening platforms is steeply increasing. Early detection and treatment of DR are key public health interventions that can greatly reduce the likelihood of vision loss. Current DR screening programs typically employ retinal fundus photography, which relies on skilled readers for manual DR assessment. However, this is labor-intensive and suffers from inconsistency across sites. Hence, there has been a recent proliferation of automated retinal image analysis software that may potentially alleviate this burden cost-effectively. Furthermore, current screening programs based on 2-dimensional fundus photography do not effectively screen for diabetic macular edema (DME). Optical coherence tomography is becoming increasingly recognized as the reference standard for DME assessment and can potentially provide a cost-effective solution for improving DME detection in large-scale DR screening programs. Current screening techniques are also unable to image the peripheral retina and require pharmacological pupil dilation; ultra-widefield imaging and confocal scanning laser ophthalmoscopy, which address these drawbacks, possess great potential. In this review, we summarize the current DR screening methods using various retinal imaging techniques, and also outline future possibilities. Advances in retinal imaging techniques can potentially transform the management of patients with diabetes, providing savings in health care costs and resources. © 2016 Diabetes Technology Society.

Optimisation of wavelength modulated Raman spectroscopy: towards high throughput cell screening.

PubMed

Praveen, Bavishna B; Mazilu, Michael; Marchington, Robert F; Herrington, C Simon; Riches, Andrew; Dholakia, Kishan

2013-01-01

In the field of biomedicine, Raman spectroscopy is a powerful technique to discriminate between normal and cancerous cells. However the strong background signal from the sample and the instrumentation affects the efficiency of this discrimination technique. Wavelength Modulated Raman spectroscopy (WMRS) may suppress the background from the Raman spectra. In this study we demonstrate a systematic approach for optimizing the various parameters of WMRS to achieve a reduction in the acquisition time for potential applications such as higher throughput cell screening. The Signal to Noise Ratio (SNR) of the Raman bands depends on the modulation amplitude, time constant and total acquisition time. It was observed that the sampling rate does not influence the signal to noise ratio of the Raman bands if three or more wavelengths are sampled. With these optimised WMRS parameters, we increased the throughput in the binary classification of normal human urothelial cells and bladder cancer cells by reducing the total acquisition time to 6 s which is significantly lower in comparison to previous acquisition times required for the discrimination between similar cell types.

Avoidance of an electric field by insects: Fundamental biological phenomenon for an electrostatic pest-exclusion strategy

NASA Astrophysics Data System (ADS)

Matsuda, Y.; Nonomura, T.; Kakutani, K.; Kimbara, J.; Osamura, K.; Kusakari, S.; Toyoda, H.

2015-10-01

An electric field screen is a physical device used to exclude pest insects from greenhouses and warehouses to protect crop production and storage. The screen consists of iron insulated conductor wires (ICWs) arrayed in parallel and linked to each other, an electrostatic DC voltage generator used to supply a negative charge to the ICWs, and an earthed stainless net placed on one side of the ICW layer. The ICW was negatively charged to polarize the earthed net to create a positive charge on the ICW side surface, and an electric field formed between the opposite charges of the ICW and earthed net. The current study focused on the ability of the screen to repel insects reaching the screen net. This repulsion was a result of the insect's behaviour, i.e., the insects were deterred from entering the electric field of the screen. In fact, when the screen was negatively charged with the appropriate voltages, the insects placed their antennae inside the screen and then flew away without entering. Obviously, the insects recognized the electric field using their antennae and thereby avoided entering. Using a wide range of insects and spiders belonging to different taxonomic groups, we confirmed that the avoidance response to the electric field was common in these animals.

A new framework for interactive quality assessment with application to light field coding

NASA Astrophysics Data System (ADS)

Viola, Irene; Ebrahimi, Touradj

2017-09-01

In recent years, light field has experienced a surge of popularity, mainly due to the recent advances in acquisition and rendering technologies that have made it more accessible to the public. Thanks to image-based rendering techniques, light field contents can be rendered in real time on common 2D screens, allowing virtual navigation through the captured scenes in an interactive fashion. However, this richer representation of the scene poses the problem of reliable quality assessments for light field contents. In particular, while subjective methodologies that enable interaction have already been proposed, no work has been done on assessing how users interact with light field contents. In this paper, we propose a new framework to subjectively assess the quality of light field contents in an interactive manner and simultaneously track users behaviour. The framework is successfully used to perform subjective assessment of two coding solutions. Moreover, statistical analysis performed on the results shows interesting correlation between subjective scores and average interaction time.

Total-Internal-Reflection Platforms for Chemical and Biological Sensing Applications

NASA Astrophysics Data System (ADS)

Sapsford, Kim E.

Sensing platforms based on the principle of total internal reflection (TIR) represent a fairly mature yet still expanding and exciting field of research. Sensor development has mainly been driven by the need for rapid, stand-alone, automated devices for application in the fields of clinical diagnosis and screening, food and water safety, environmental monitoring, and chemical and biological warfare agent detection. The technologies highlighted in this chapter are continually evolving, taking advantage of emerging advances in microfabrication, lab-on-a-chip, excitation, and detection techniques. This chapter describes many of the underlying principles of TIR-based sensing platforms and additionally focusses on planar TIR fluorescence (TIRF)-based chemical and biological sensors.

Density of states and magnetotransport in Weyl semimetals with long-range disorder

NASA Astrophysics Data System (ADS)

Pesin, D. A.; Mishchenko, E. G.; Levchenko, A.

2015-11-01

We study the density of states and magnetotransport properties of disordered Weyl semimetals, focusing on the case of a strong long-range disorder. To calculate the disorder-averaged density of states close to nodal points, we treat exactly the long-range random potential fluctuations produced by charged impurities, while the short-range component of disorder potential is included systematically and controllably with the help of a diagram technique. We find that, for energies close to the degeneracy point, long-range potential fluctuations lead to a finite density of states. In the context of transport, we discuss that a self-consistent theory of screening in magnetic field may conceivably lead to nonmonotonic low-field magnetoresistance.

Computer-Aided Diagnostic System For Mass Survey Chest Images

NASA Astrophysics Data System (ADS)

Yasuda, Yoshizumi; Kinoshita, Yasuhiro; Emori, Yasufumi; Yoshimura, Hitoshi

1988-06-01

In order to support screening of chest radiographs on mass survey, a computer-aided diagnostic system that automatically detects abnormality of candidate images using a digital image analysis technique has been developed. Extracting boundary lines of lung fields and examining their shapes allowed various kind of abnormalities to be detected. Correction and expansion were facilitated by describing the system control, image analysis control and judgement of abnormality in the rule type programing language. In the experiments using typical samples of student's radiograms, good results were obtained for the detection of abnormal shape of lung field, cardiac hypertrophy and scoliosis. As for the detection of diaphragmatic abnormality, relatively good results were obtained but further improvements will be necessary.

The Screen Display Syntax for CAI.

ERIC Educational Resources Information Center

Richards, Boyd F.; Salisbury, David F.

1987-01-01

Describes four storyboard techniques frequently used in designing computer assisted instruction (CAI) programs, and explains screen display syntax (SDS), a new technique combining the major advantages of the storyboard techniques. SDS was developed to facilitate communication among designers, programmers, and editors working on a large CAI basic…

Neuroleadership: Themes and limitations of an emerging interdisciplinary field.

PubMed

Kuhlmann, Naila; Kadgien, Chelsie A

2018-05-01

The relationship between brain and behaviour has perplexed philosophers and scientists since the time of the ancient Greeks. Recent technological advances have allowed neuroscience to flourish, alongside growing romanticism that reductionist studies will allow us to understand complex interpersonal behaviours. Organizational cognitive neuroscience and neuroleadership are newly established interdisciplinary fields that use neuroscientific techniques to answer questions about behaviours within organizations. Neuroleadership aims to discover screening tools for good leaders, to improve leadership skills, and to identify unconscious factors affecting behaviour in hopes of improving management and leadership practices. Although proponents of neuroleadership are optimistic, if we know anything about the functions of the human brain and our interpersonal behaviours, it is that they are exquisitely complex and context dependant. Here, we briefly discuss the major themes emerging in the new field of neuroleadership and the limitations and potential consequences of applying findings from the field prematurely and with blind optimism.

Screening the Molecular Framework Underlying Local Dendritic mRNA Translation

PubMed Central

Namjoshi, Sanjeev V.; Raab-Graham, Kimberly F.

2017-01-01

In the last decade, bioinformatic analyses of high-throughput proteomics and transcriptomics data have enabled researchers to gain insight into the molecular networks that may underlie lasting changes in synaptic efficacy. Development and utilization of these techniques have advanced the field of learning and memory significantly. It is now possible to move from the study of activity-dependent changes of a single protein to modeling entire network changes that require local protein synthesis. This data revolution has necessitated the development of alternative computational and statistical techniques to analyze and understand the patterns contained within. Thus, the focus of this review is to provide a synopsis of the journey and evolution toward big data techniques to address still unanswered questions regarding how synapses are modified to strengthen neuronal circuits. We first review the seminal studies that demonstrated the pivotal role played by local mRNA translation as the mechanism underlying the enhancement of enduring synaptic activity. In the interest of those who are new to the field, we provide a brief overview of molecular biology and biochemical techniques utilized for sample preparation to identify locally translated proteins using RNA sequencing and proteomics, as well as the computational approaches used to analyze these data. While many mRNAs have been identified, few have been shown to be locally synthesized. To this end, we review techniques currently being utilized to visualize new protein synthesis, a task that has proven to be the most difficult aspect of the field. Finally, we provide examples of future applications to test the physiological relevance of locally synthesized proteins identified by big data approaches. PMID:28286470

Non-interferometric quantitative phase imaging of yeast cells

NASA Astrophysics Data System (ADS)

Poola, Praveen K.; Pandiyan, Vimal Prabhu; John, Renu

2015-12-01

Real-time imaging of live cells is quite difficult without the addition of external contrast agents. Various methods for quantitative phase imaging of living cells have been proposed like digital holographic microscopy and diffraction phase microscopy. In this paper, we report theoretical and experimental results of quantitative phase imaging of live yeast cells with nanometric precision using transport of intensity equations (TIE). We demonstrate nanometric depth sensitivity in imaging live yeast cells using this technique. This technique being noninterferometric, does not need any coherent light sources and images can be captured through a regular bright-field microscope. This real-time imaging technique would deliver the depth or 3-D volume information of cells and is highly promising in real-time digital pathology applications, screening of pathogens and staging of diseases like malaria as it does not need any preprocessing of samples.

Maximizing the quantitative accuracy and reproducibility of Förster resonance energy transfer measurement for screening by high throughput widefield microscopy

PubMed Central

Schaufele, Fred

2013-01-01

Förster resonance energy transfer (FRET) between fluorescent proteins (FPs) provides insights into the proximities and orientations of FPs as surrogates of the biochemical interactions and structures of the factors to which the FPs are genetically fused. As powerful as FRET methods are, technical issues have impeded their broad adoption in the biologic sciences. One hurdle to accurate and reproducible FRET microscopy measurement stems from variable fluorescence backgrounds both within a field and between different fields. Those variations introduce errors into the precise quantification of fluorescence levels on which the quantitative accuracy of FRET measurement is highly dependent. This measurement error is particularly problematic for screening campaigns since minimal well-to-well variation is necessary to faithfully identify wells with altered values. High content screening depends also upon maximizing the numbers of cells imaged, which is best achieved by low magnification high throughput microscopy. But, low magnification introduces flat-field correction issues that degrade the accuracy of background correction to cause poor reproducibility in FRET measurement. For live cell imaging, fluorescence of cell culture media in the fluorescence collection channels for the FPs commonly used for FRET analysis is a high source of background error. These signal-to-noise problems are compounded by the desire to express proteins at biologically meaningful levels that may only be marginally above the strong fluorescence background. Here, techniques are presented that correct for background fluctuations. Accurate calculation of FRET is realized even from images in which a non-flat background is 10-fold higher than the signal. PMID:23927839

Development of an endoscopic fluorescence image-guided OCT probe for oral cancer detection

NASA Astrophysics Data System (ADS)

McNichols, Roger J.; Gowda, Ashok; Bell, Brent A.; Johnigan, Richard M.; Calhoun, Karen H.; Motamedi, Massoud

2001-06-01

Oral squamous cell carcinoma is a disease which progresses through a number of well-defined morphological and biochemical changes. Optical coherence tomography (OCT) is a rapidly-evolving, non-invasive imaging modality which allows detailed probing of subsurface tissue structures with resolution on the order of microns. While this technique offers tremendous potential as a diagnostic tool for detection and characterization of oral cancer, OCT imaging is presently associated with a field of view on the order of millimeters, and acquisition time on the order of seconds. Thus, OCT's utility as a rapid cancer screening technique is presently limited. On the other hand, imaging of tissue autofluorescence provides a very rapid, high-throughput method for cancer screening. However, while autofluorescence measures may be sensitive to cancer, they are often non- specific and lead to a large number of false positives. In the present work, we have developed a fluorescence image guided optical coherence tomographic (FIG-OCT) probe in which tissue autofluorescence images are simultaneously used to guide OCT image acquisition of suspicious regions in real time. We have begun pre-clinical pilot studies with this instrument in a DMBA-induced model of oral cancer in the hamster cheek pouch. Initial results indicate that the FIG- OCT approach shows promise as a rapid and effective tool for screening of oral cancer.

Induced Polarization Surveying for Acid Rock Screening in Highway Design

NASA Astrophysics Data System (ADS)

Butler, K. E.; Al, T.; Bishop, T.

2004-05-01

Highway and pipeline construction agencies have become increasingly vigilant in their efforts to avoid cutting through sulphide-bearing bedrock that has potential to produce acid rock drainage. Blasting and fragmentation of such rock increases the surface area available for sulphide oxidation and hence increases the risk of acid rock drainage unless the rock contains enough natural buffering capacity to neutralize the pH. In December, 2001, the New Brunswick Department of Transportation (NBOT) sponsored a field trial of geophysical surveying in order to assess its suitability as a screening tool for locating near-surface sulphides along proposed highway alignments. The goal was to develop a protocol that would allow existing programs of drilling and geochemical testing to be targeted more effectively, and provide design engineers with the information needed to reduce rock cuts where necessary and dispose of blasted material in a responsible fashion. Induced polarization (IP) was chosen as the primary geophysical method given its ability to detect low-grade disseminated mineralization. The survey was conducted in dipole-dipole mode using an exploration-style time domain IP system, dipoles 8 to 25 m in length, and six potential dipoles for each current dipole location (i.e. n = 1 - 6). Supplementary information was provided by resistivity and VLF-EM surveys sensitive to lateral changes in electrical conductivity, and by magnetic field surveying chosen for its sensitivity to the magnetic susceptibility of pyrrhotite. Geological and geochemical analyses of samples taken from several IP anomalies located along 4.3 line-km of proposed highway confirmed the effectiveness of the screening technique. IP pseudosections from a region of metamorphosed shales and volcaniclastic rocks identified discrete, well-defined mineralized zones. Stronger, overlapping, and more laterally extensive IP anomalies were observed over a section of graphitic and sulphide-bearing metasedimentary rocks. Attempts to use spectral IP characteristics to determine relative abundances of sulphides and graphite were not conclusive. The overall effectiveness of the screening technique however encouraged NBDOT to apply it to an additional 50 km of planned rock cuts along the corridor selected for the new Trans-Canada Highway.

Cystic fibrosis: to screen or not to screen? Involving a Citizens' jury in decisions on screening carrier.

PubMed

Mosconi, Paola; Castellani, Carlo; Villani, Walter; Satolli, Roberto

2015-12-01

In recent years, the continuous improvements in molecular biology techniques have made it possible to detect carriers for several genetic conditions, including cystic fibrosis (CF). In some countries, CF carrier screening is offered to increasing subset of the general population. Offering of carrier screening at a population level should not be decided by local health authorities only, without consulting citizens' preferences. One way to involve citizens in the decision process might be to a Citizens' jury, a method of deliberative democracy. The object of the study is to produce a recommendation statement about CF carrier screening using a Citizens' jury. As this is a new method in the field, the study also provided the opportunity to evaluate its effectiveness. The project is designed and managed by an executive committee. The whole process is superintended by a multidisciplinary scientific committee. The 16 members of the jury attend a 1 day meeting, assisted by a non-medical and unbiased facilitator. Informative material was prepared and distributed 15 days before the jury meeting; during the meeting, experts and witnesses interact directly with all the jurors through questions and answers. All except one member of the jury felt positively about the Health Service actively providing population carrier screening for CF. The final statement was available to public, clinicians, researchers and decision-makers. In general, a Citizens' jury is a feasible method for involving citizens in public health decision-making process and in particular for obtaining a community view about CF carrier screening. © 2014 The Authors Health Expectations Published by John Wiley & Sons Ltd.

Classification of Tropical Oceanic Precipitation using High Altitude Aircraft: Microwave and Electric Field Measurements

NASA Technical Reports Server (NTRS)

Hood, Robbie E.; Cecil, Daniel; LaFontaine, Frank J.; Blakeslee, Richard; Mach, Douglas; Heymsfield, Gerald; Marks, Frank, Jr.; Zipser, Edward

2004-01-01

During the 1998 and 2001 hurricane seasons of the western Atlantic Ocean and Gulf of Mexico, the Advanced Microwave Precipitation Radiometer (AMPR), the ER-2 Doppler (EDOP) radar, and the Lightning Instrument Package (LIP) were flown aboard the National Aeronautics and Space Administration ER-2 high altitude aircraft as part of the Third Convection and Moisture Experiment (CAMEX-3) and the Fourth Convection and Moisture Experiment (CAMEX-4). Several hurricanes, tropical storms, and other precipitation systems were sampled during these experiments. An oceanic rainfall screening technique has been developed using AMPR passive microwave observations of these systems collected at frequencies of 10.7, 19.35,37.1, and 85.5 GHz. This technique combines the information content of the four AMPR frequencies regarding the gross vertical structure of hydrometeors into an intuitive and easily executable precipitation mapping format. The results have been verified using vertical profiles of EDOP reflectivity and lower altitude horizontal reflectivity scans collected by the National Oceanic and Atmospheric Administration WP-3D Orion radar. Matching the rainfall classification results with coincident electric field information collected by the LIP readily identifies convective rain regions within the precipitation fields. This technique shows promise as a real-time research and analysis tool for monitoring vertical updraft strength and convective intensity from airborne platforms such as remotely operated or uninhabited aerial vehicles. The technique is analyzed and discussed for a wide variety of precipitation types using the 26 August 1998 observations of Hurricane Bonnie near landfall.

Portable retinal imaging for eye disease screening using a consumer-grade digital camera

NASA Astrophysics Data System (ADS)

Barriga, Simon; Larichev, Andrey; Zamora, Gilberto; Soliz, Peter

2012-03-01

The development of affordable means to image the retina is an important step toward the implementation of eye disease screening programs. In this paper we present the i-RxCam, a low-cost, hand-held, retinal camera for widespread applications such as tele-retinal screening for eye diseases like diabetic retinopathy (DR), glaucoma, and age-related ocular diseases. Existing portable retinal imagers do not meet the requirements of a low-cost camera with sufficient technical capabilities (field of view, image quality, portability, battery power, and ease-of-use) to be distributed widely to low volume clinics, such as the offices of single primary care physicians serving rural communities. The i-RxCam uses a Nikon D3100 digital camera body. The camera has a CMOS sensor with 14.8 million pixels. We use a 50mm focal lens that gives a retinal field of view of 45 degrees. The internal autofocus can compensate for about 2D (diopters) of focusing error. The light source is an LED produced by Philips with a linear emitting area that is transformed using a light pipe to the optimal shape at the eye pupil, an annulus. To eliminate corneal reflex we use a polarization technique in which the light passes through a nano-wire polarizer plate. This is a novel type of polarizer featuring high polarization separation (contrast ratio of more than 1000) and very large acceptance angle (>45 degrees). The i-RxCam approach will yield a significantly more economical retinal imaging device that would allow mass screening of the at-risk population.

Human iPSC-derived cardiomyocytes and tissue engineering strategies for disease modeling and drug screening.

PubMed

Smith, Alec S T; Macadangdang, Jesse; Leung, Winnie; Laflamme, Michael A; Kim, Deok-Ho

Improved methodologies for modeling cardiac disease phenotypes and accurately screening the efficacy and toxicity of potential therapeutic compounds are actively being sought to advance drug development and improve disease modeling capabilities. To that end, much recent effort has been devoted to the development of novel engineered biomimetic cardiac tissue platforms that accurately recapitulate the structure and function of the human myocardium. Within the field of cardiac engineering, induced pluripotent stem cells (iPSCs) are an exciting tool that offer the potential to advance the current state of the art, as they are derived from somatic cells, enabling the development of personalized medical strategies and patient specific disease models. Here we review different aspects of iPSC-based cardiac engineering technologies. We highlight methods for producing iPSC-derived cardiomyocytes (iPSC-CMs) and discuss their application to compound efficacy/toxicity screening and in vitro modeling of prevalent cardiac diseases. Special attention is paid to the application of micro- and nano-engineering techniques for the development of novel iPSC-CM based platforms and their potential to advance current preclinical screening modalities. Published by Elsevier Inc.

Reliable screening of various foodstuffs with respect to their irradiation status: A comparative study of different analytical techniques

NASA Astrophysics Data System (ADS)

Ahn, Jae-Jun; Akram, Kashif; Kwak, Ji-Young; Jeong, Mi-Seon; Kwon, Joong-Ho

2013-10-01

Cost-effective and time-efficient analytical techniques are required to screen large food lots in accordance to their irradiation status. Gamma-irradiated (0-10 kGy) cinnamon, red pepper, black pepper, and fresh paprika were investigated using photostimulated luminescence (PSL), direct epifluorescent filter technique/the aerobic plate count (DEFT/APC), and electronic-nose (e-nose) analyses. The screening results were also confirmed with thermoluminescence analysis. PSL analysis discriminated between irradiated (positive, >5000 PCs) and non-irradiated (negative, <700 PCs) cinnamon and red peppers. Black pepper had intermediate results (700-5000 PCs), while paprika had low sensitivity (negative results) upon irradiation. The DEFT/APC technique also showed clear screening results through the changes in microbial profiles, where the best results were found in paprika, followed by red pepper and cinnamon. E-nose analysis showed a dose-dependent discrimination in volatile profiles upon irradiation through principal component analysis. These methods can be used considering their potential applications for the screening analysis of irradiated foods.

Continuous microfluidic assortment of interactive ligands (CMAIL)

NASA Astrophysics Data System (ADS)

Hsiao, Yi-Hsing; Huang, Chao-Yang; Hu, Chih-Yung; Wu, Yen-Yu; Wu, Chung-Hsiun; Hsu, Chia-Hsien; Chen, Chihchen

2016-08-01

Finding an interactive ligand-receptor pair is crucial to many applications, including the development of monoclonal antibodies. Biopanning, a commonly used technique for affinity screening, involves a series of washing steps and is lengthy and tedious. Here we present an approach termed continuous microfluidic assortment of interactive ligands, or CMAIL, for the screening and sorting of antigen-binding single-chain variable antibody fragments (scFv) displayed on bacteriophages (phages). Phages carrying native negative charges on their coat proteins were electrophoresed through a hydrogel matrix functionalized with target antigens under two alternating orthogonal electric fields. During the weak horizontal electric field phase, phages were differentially swept laterally depending on their affinity for the antigen, and all phages were electrophoresed down to be collected during the strong vertical electric field phase. Phages of different affinity were spatially separated, allowing the continuous operation. More than 105 CFU (colony forming unit) antigen-interacting phages were isolated with ~100% specificity from a phage library containing 3 × 109 individual members within 40 minutes of sorting using CMAIL. CMAIL is rapid, sensitive, specific, and does not employ washing, elution or magnetic beads. In conclusion, we have developed an efficient and cost-effective method for isolating and sorting affinity reagents involving phage display.

Development of a loop-mediated isothermal amplification method for rapid mass-screening of sand flies for Leishmania infection.

PubMed

Nzelu, Chukwunonso O; Gomez, Eduardo A; Cáceres, Abraham G; Sakurai, Tatsuya; Martini-Robles, Luiggi; Uezato, Hiroshi; Mimori, Tatsuyuki; Katakura, Ken; Hashiguchi, Yoshihisa; Kato, Hirotomo

2014-04-01

Entomological monitoring of Leishmania infection in leishmaniasis endemic areas offers epidemiologic advantages for predicting the risk and expansion of the disease, as well as evaluation of the effectiveness of control programs. In this study, we developed a highly sensitive loop-mediated isothermal amplification (LAMP) method for the mass screening of sand flies for Leishmania infection based on the 18S rRNA gene. The LAMP technique could detect 0.01 parasites, which was more sensitive than classical PCR. The method was robust and could amplify the target DNA within 1h from a crude sand fly template without DNA purification. Amplicon detection could be accomplished by the newly developed colorimetric malachite green (MG)--mediated naked eye visualization. Pre-addition of MG to the LAMP reaction solution did not inhibit amplification efficiency. The field applicability of the colorimetric MG-based LAMP assay was demonstrated with 397 field-caught samples from the endemic areas of Ecuador and eight positive sand flies were detected. The robustness, superior sensitivity, and ability to produce better visual discriminatory reaction products than existing LAMP fluorescence and turbidity assays indicated the field potential usefulness of this new method for surveillance and epidemiological studies of leishmaniasis in developing countries. Copyright © 2013 Elsevier B.V. All rights reserved.

Giga-pixel fluorescent imaging over an ultra-large field-of-view using a flatbed scanner.

PubMed

Göröcs, Zoltán; Ling, Yuye; Yu, Meng Dai; Karahalios, Dimitri; Mogharabi, Kian; Lu, Kenny; Wei, Qingshan; Ozcan, Aydogan

2013-11-21

We demonstrate a new fluorescent imaging technique that can screen for fluorescent micro-objects over an ultra-wide field-of-view (FOV) of ~532 cm(2), i.e., 19 cm × 28 cm, reaching a space-bandwidth product of more than 2 billion. For achieving such a large FOV, we modified the hardware and software of a commercially available flatbed scanner, and added a custom-designed absorbing fluorescent filter, a two-dimensional array of external light sources for computer-controlled and high-angle fluorescent excitation. We also re-programmed the driver of the scanner to take full control of the scanner hardware and achieve the highest possible exposure time, gain and sensitivity for detection of fluorescent micro-objects through the gradient index self-focusing lens array that is positioned in front of the scanner sensor chip. For example, this large FOV of our imaging platform allows us to screen more than 2.2 mL of undiluted whole blood for detection of fluorescent micro-objects within <5 minutes. This high-throughput fluorescent imaging platform could be useful for rare cell research and cytometry applications by enabling rapid screening of large volumes of optically dense media. Our results constitute the first time that a flatbed scanner has been converted to a fluorescent imaging system, achieving a record large FOV.

Non-contact, non-destructive, quantitative probing of interfacial trap sites for charge carrier transport at semiconductor-insulator boundary

NASA Astrophysics Data System (ADS)

Choi, Wookjin; Miyakai, Tomoyo; Sakurai, Tsuneaki; Saeki, Akinori; Yokoyama, Masaaki; Seki, Shu

2014-07-01

The density of traps at semiconductor-insulator interfaces was successfully estimated using microwave dielectric loss spectroscopy with model thin-film organic field-effect transistors. The non-contact, non-destructive analysis technique is referred to as field-induced time-resolved microwave conductivity (FI-TRMC) at interfaces. Kinetic traces of FI-TRMC transients clearly distinguished the mobile charge carriers at the interfaces from the immobile charges trapped at defects, allowing both the mobility of charge carriers and the number density of trap sites to be determined at the semiconductor-insulator interfaces. The number density of defects at the interface between evaporated pentacene on a poly(methylmethacrylate) insulating layer was determined to be 1012 cm-2, and the hole mobility was up to 6.5 cm2 V-1 s-1 after filling the defects with trapped carriers. The FI-TRMC at interfaces technique has the potential to provide rapid screening for the assessment of interfacial electronic states in a variety of semiconductor devices.

Factors predicting health practitioners' awareness of UNHS program in Malaysian non-public hospitals.

PubMed

Ismail, Abdussalaam Iyanda; Abdul Majid, Abdul Halim; Zakaria, Mohd Normani; Abdullah, Nor Azimah Chew; Hamzah, Sulaiman; Mukari, Siti Zamratol-Mai Sarah

2018-06-01

The current study aims to examine the effects of human resource (measured with the perception of health workers' perception towards UNHS), screening equipment, program layout and screening techniques on healthcare practitioners' awareness (measured with knowledge) of universal newborn hearing screening (UNHS) in Malaysian non-public hospitals. Via cross sectional approach, the current study collected data using a validated questionnaire to obtain information on the awareness of UNHS program among the health practitioners and to test the formulated hypotheses. 51, representing 81% response rate, out of 63 questionnaires distributed to the health professionals were returned and usable for statistical analysis. The survey instruments involving healthcare practitioners' awareness, human resource, program layout, screening instrument, and screening techniques instruments were adapted and scaled with 7-point Likert scale ranging from 1 (little) to 7 (many). Partial Least Squares (PLS) algorithm and bootstrapping techniques were employed to test the hypotheses of the study. With the result involving beta values, t-values and p-values (i.e. β=0.478, t=1.904, p<0.10; β=0.809, t=3.921, p<0.01; β= -0.436, t=1.870, p<0.10), human resource, measured with training, functional equipment and program layout, are held to be significant predictors of enhanced knowledge of health practitioners. Likewise, program layout, human resource, screening technique and screening instrument explain 71% variance in health practitioners' awareness. Health practitioners' awareness is explained by program layout, human resource, and screening instrument with effect size (f2) of 0.065, 0.621, and 0.211 respectively, indicating that program layout, human resource, and screening instrument have small, large and medium effect size on health practitioners' awareness respectively. However, screening technique has zero effect on health practitioners' awareness, indicating the reason why T-statistics is not significant. Having started the UNHS program in 2003, non-public hospitals have more experienced and well-trained employees dealing with the screening tools and instrument, and the program layout is well structured in the hospitals. Yet, the issue of homogeneity exists. Non-public hospitals charge for the service they render, and, in turn, they would ensure quality service, given that they are profit-driven and/or profit-making establishments, and that they would have no option other than provision of value-added and innovative services. The employees in the non-public hospitals have less screening to carry out, given the low number of babies delivered in the private hospitals. In addition, non-significant relationship between screening techniques and healthcare practitioners' awareness of UNHS program is connected with the fact that the techniques that are practiced among public and non-public hospital are similar and standardized. Limitations and suggestions were discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

Reliability of techniques used in the diagnosis of canine visceral leishmaniasis by the national control program in Brazil: A survey in an area of recent transmission.

PubMed

Belo, Vinícius Silva; Gregório, Eliana Aparecida; Teixeira-Neto, Rafael Gonçalves; da Rocha Lima, Ana Cristina Vianna Mariano; Pereira, Agnes Antônia Sampaio; Marcelino, Andreza Pain; Paz, Gustavo Fontes; da Silva, Eduardo Sérgio

2017-10-01

One of the key components of the Brazilian Program for the Control of Visceral Leishmaniasis (PCLV) is the euthanasia of Leishmania-infected canine reservoirs, the detection of which depends on a screening procedure involving a Dual Path Platform ® (DPP) immunoassay and a confirmatory enzyme-linked immunosorbent assay (ELISA). The aims of the present study were to evaluate the reliability of these techniques in a region of recent transmission of canine VL, to follow up the seroconversion 3-4 months after the initial diagnosis of DPP reactive but ELISA indeterminate or non-reactive dogs, and to identify the species of Leishmania in circulation in the area. Each animal was submitted to DPP under field conditions, performed by municipal health workers using peripheral blood (DPP-field), to DPP under laboratory conditions using serum (DPP-lab) and to ELISA using serum. The agreements between the tests were determined using McNemar's χ 2 test, Cohen's kappa coefficient (k) at the 95% confidence interval and prevalence-adjusted bias-adjusted kappa (PABAK). Of the 1130 dogs examined, 74.2% were non-reactive in all three tests applied. Based on the PCLV positive-infection criterion, seroprevalence was 8.9% (101/1130) with 83.2% (84/101) of infected animals showing reactivity in all three tests while 7.8% (8/101) were reactive in DPP-field and ELISA and 8.9% (9/101) in DPP-lab and ELISA. The proportions of disagreements were substantial in all comparisons. Inter-rater reliability between DPP-field and ELISA (k=0.55; PABAK=0.78) and DPP-lab and ELISA (k=0.59; PABAK=0.81) were considered moderate, while that between DPP-field and DPP-lab (k=0.61; PABAK=0.79) was classified as marginally good. The proportion of seroconversions in DPP reactive animals that were initially ELISA indeterminate was significantly higher than in those that were DPP reactive but initially ELISA non-reactive. Restriction fragment length polymorphism analysis revealed the presence of Leishmania infantum, the etiologic agent of VL, in bone marrow samples from VL-infected animals. Our data showed that the techniques and protocols currently employed in the PCLV screening approach are not entirely reliable. Further consideration should be given to monitoring dogs with undetermined results in ELISA and a better training should be provided for health workers responsible for performing DPP tests applied under field conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Optimization of printing techniques for electrochemical biosensors

NASA Astrophysics Data System (ADS)

Zainuddin, Ahmad Anwar; Mansor, Ahmad Fairuzabadi Mohd; Rahim, Rosminazuin Ab; Nordin, Anis Nurashikin

2017-03-01

Electrochemical biosensors show great promise for point-of-care applications due to their low cost, portability and compatibility with microfluidics. The miniature size of these sensors provides advantages in terms of sensitivity, specificity and allows them to be mass produced in arrays. The most reliable fabrication technique for these sensors is lithography followed by metal deposition using sputtering or chemical vapor deposition techniques. This technique which is usually done in the cleanroom requires expensive masking followed by deposition. Recently, cheaper printing techniques such as screen-printing and ink-jet printing have become popular due to its low cost, ease of fabrication and mask-less method. In this paper, two different printing techniques namely inkjet and screen printing are demonstrated for an electrochemical biosensor. For ink-jet printing technique, optimization of key printing parameters, such as pulse voltages, drop spacing and waveform setting, in-house temperature and cure annealing for obtaining the high quality droplets, are discussed. These factors are compared with screen-printing parameters such as mesh size, emulsion thickness, minimum spacing of lines and curing times. The reliability and reproducibility of the sensors are evaluated using scotch tape test, resistivity and profile-meter measurements. It was found that inkjet printing is superior because it is mask-less, has minimum resolution of 100 µm compared to 200 µm for screen printing and higher reproducibility rate of 90% compared to 78% for screen printing.

Flow visualization V; Proceedings of the 5th International Symposium, Prague, Czechoslovakia, Aug. 21-25, 1989

NASA Astrophysics Data System (ADS)

Reznicek, R.

The present conference on flow visualization encompasses methods exploiting tracing particles, surface tracing methods, methods exploiting the effects of streaming fluid on passing radiation/field, computer-aided flow visualization, and applications to fluid mechanics, aerodynamics, flow devices, shock tubes, and heat/mass transfer. Specific issues include visualizing velocity distribution by stereo photography, dark-field Fourier quasiinterferometry, speckle tomography of an open flame, a fast eye for real-time image analysis, and velocity-field determination based on flow-image analysis. Also addressed are flows around rectangular prisms with oscillating flaps at the leading edges, the tomography of aerodynamic objects, the vapor-screen technique applied to a delta-wing aircraft, flash-lamp planar imaging, IR-thermography applications in convective heat transfer, and the visualization of marangoni effects in evaporating sessile drops.

Screening and Biosensor-Based Approaches for Lung Cancer Detection

PubMed Central

Wang, Lulu

2017-01-01

Early diagnosis of lung cancer helps to reduce the cancer death rate significantly. Over the years, investigators worldwide have extensively investigated many screening modalities for lung cancer detection, including computerized tomography, chest X-ray, positron emission tomography, sputum cytology, magnetic resonance imaging and biopsy. However, these techniques are not suitable for patients with other pathologies. Developing a rapid and sensitive technique for early diagnosis of lung cancer is urgently needed. Biosensor-based techniques have been recently recommended as a rapid and cost-effective tool for early diagnosis of lung tumor markers. This paper reviews the recent development in screening and biosensor-based techniques for early lung cancer detection. PMID:29065541

High-throughput approach for the identification of anilinium-based ionic liquids that are suitable for electropolymerisation.

PubMed

Abdelhamid, Muhammad E; Murdoch, Timothy; Greaves, Tamar L; O'Mullane, Anthony P; Snook, Graeme A

2015-07-21

We report the synthesis of new protic ionic liquids (PILs) based on aniline derivatives and the use of high-throughput (HT) techniques to screen possible candidates. In this work, a simple HT method was applied to rapidly screen different aniline derivatives against different acids in order to identify possible combinations that produce PILs. This was followed by repeating the HT process with a Chemspeed robotic synthesis platform for more accurate results. One of the successful combinations were then chosen to be synthesised on a larger scale for further analysis. The new PILs are of interest to the fields of ionic liquids, energy storage and especially, conducting polymers as they serve as solvents, electrolytes and monomers at the same time for possible electropolymerisation (i.e. a self-contained polymer precursor).

Quantifying the effect of ionic screening with protein-decorated graphene transistors

PubMed Central

Ping, Jinglei; Xi, Jin; Saven, Jeffery G.; Liu, Renyu; Charlie Johnson, A. T.

2015-01-01

Liquid-based applications of biomolecule-decorated field-effect transistors (FETs) range from biosensors to in vivo implants. A critical scientific challenge is to develop a quantitative understanding of the gating effect of charged biomolecules in ionic solution and how this influences the readout of the FETs. To address this issue, we fabricated protein-decorated graphene FETs and measured their electrical properties, specifically the shift in Dirac voltage, in solutions of varying ionic strength. We found excellent quantitative agreement with a model that accounts for both the graphene polarization charge and ionic screening of ions adsorbed on the graphene as well as charged amino acids associated with the immobilized protein. The technique and analysis presented here directly couple the charging status of bound biomolecules to readout of liquid-phase FETs fabricated with graphene or other two-dimensional materials. PMID:26626969

Methods for studying the zebrafish brain: past, present and future.

PubMed

Wyatt, Cameron; Bartoszek, Ewelina M; Yaksi, Emre

2015-07-01

The zebrafish (Danio rerio) is one of the most promising new model organisms. The increasing popularity of this amazing small vertebrate is evident from the exponentially growing numbers of research articles, funded projects and new discoveries associated with the use of zebrafish for studying development, brain function, human diseases and screening for new drugs. Thanks to the development of novel technologies, the range of zebrafish research is constantly expanding with new tools synergistically enhancing traditional techniques. In this review we will highlight the past and present techniques which have made, and continue to make, zebrafish an attractive model organism for various fields of biology, with a specific focus on neuroscience. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Measurement of drug facilitated sexual assault agents in simulated sweat by ion mobility spectrometry.

PubMed

Demoranville, Leonard T; Verkouteren, Jennifer R

2013-03-15

Ion mobility spectrometry has found widespread use for the detection of explosives and illicit drugs. The technique offers rapid results with high sensitivity and little sample preparation. As such, it is well suited for field deployed screening settings. Here the response of ion mobility spectrometers for three drug-facilitated sexual assault (DFSA) agents - flunitrazepam, ketamine, and MDMA - and related metabolites has been studied in the presence of a simulated sweat. While all three DFSA agents present certain challenges for qualitative identification, IMS can provide useful information to guide the early treatment and investigation of sexual assault cases. Used as a presumptive test, the identification of DFSA agents would later require confirmatory analysis by other techniques. Published by Elsevier B.V.

Screening Technique for Lead and Cadmium in Toys and Other Materials Using Atomic Absorption Spectroscopy

ERIC Educational Resources Information Center

Brouwer, Henry

2005-01-01

A simple procedure to quickly screen different consumer products for the presence of lead, cadmium, and other metals is described. This screening technique avoids expending a lot of preparation time on samples known to contain low levels of hazardous metals where only samples testing positive for the desired elements need to be analyzed…

Direct imaging of explosives.

PubMed

Knapp, E A; Moler, R B; Saunders, A W; Trower, W P

2000-01-01

Any technique that can detect nitrogen concentrations can screen for concealed explosives. However, such a technique would have to be insensitive to metal, both encasing and incidental. If images of the nitrogen concentrations could be captured, then, since form follows function, a robust screening technology could be developed. However these images would have to be sensitive to the surface densities at or below that of the nitrogen contained in buried anti-personnel mines or of the SEMTEX that brought down Pan Am 103, approximately 200 g. Although the ability to image in three-dimensions would somewhat reduce false positives, capturing collateral images of carbon and oxygen would virtually assure that nitrogenous non-explosive material like fertilizer, Melmac dinnerware, and salami could be eliminated. We are developing such an instrument, the Nitrogen Camera, which has met experimentally these criteria with the exception of providing oxygen images, which awaits the availability of a sufficiently energetic light source. Our Nitrogen Camera technique uses an electron accelerator to produce photonuclear reactions whose unique decays it registers. Clearly if our Nitrogen Camera is made mobile, it could be effective in detecting buried mines, either in an active battlefield situation or in the clearing of abandoned military munitions. Combat operations require that a swathe the width of an armored vehicle, 5 miles deep, be screened in an hour, which is within our camera's scanning speed. Detecting abandoned munitions is technically easier as it is free from the onerous speed requirement. We describe here our Nitrogen Camera and show its 180 pixel intensity images of elemental nitrogen in a 200 g mine simulant and in a 125 g stick of SEMTEX. We also report on our progress in creating a lorry transportable 70 MeV electron racetrack microtron, the principal enabling technology that will allow our Nitrogen Camera to be deployed in the field.

Electron emission from chemical vapor deposited diamond and amorphous carbon films observed with a simple field emission device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Z.; Brown, I.G.; Ager, J.W. III

Electron emission from chemical vapor deposited (CVD) diamond and amorphous carbon (a-C) films was observed with a simple field emission device (FED). Both diamond and a-C films were prepared with microwave plasma-enhanced CVD techniques. Electron emission in the field strength range +10 to {minus}10 MVm{sup {minus}1} was studied, and the field emission source was confirmed by a diode characteristic of the {ital I}-{ital V} curve, a straight line in the Fowler--Nordheim (F-N) plot, and direct observation of light emission from a fluorescent screen. The turn-on field strength was {similar_to}5 MVm{sup {minus}1}, which was similar for both kinds of carbon films.more » The highest current density for diamond films, observed at a field strength of 10 MVm{sup {minus}1}, was {similar_to}15 {mu}A cm{sup {minus}2}. Diamond films yielded a higher emission current than a-C films. The reasons for the observed field emission are discussed.« less

Improving the geological interpretation of magnetic and gravity satellite anomalies

NASA Technical Reports Server (NTRS)

Hinze, William J.; Braile, Lawrence W.; Vonfrese, Ralph R. B.

1987-01-01

Quantitative analysis of the geologic component of observed satellite magnetic and gravity fields requires accurate isolation of the geologic component of the observations, theoretically sound and viable inversion techniques, and integration of collateral, constraining geologic and geophysical data. A number of significant contributions were made which make quantitative analysis more accurate. These include procedures for: screening and processing orbital data for lithospheric signals based on signal repeatability and wavelength analysis; producing accurate gridded anomaly values at constant elevations from the orbital data by three-dimensional least squares collocation; increasing the stability of equivalent point source inversion and criteria for the selection of the optimum damping parameter; enhancing inversion techniques through an iterative procedure based on the superposition theorem of potential fields; and modeling efficiently regional-scale lithospheric sources of satellite magnetic anomalies. In addition, these techniques were utilized to investigate regional anomaly sources of North and South America and India and to provide constraints to continental reconstruction. Since the inception of this research study, eleven papers were presented with associated published abstracts, three theses were completed, four papers were published or accepted for publication, and an additional manuscript was submitted for publication.

A feasibility study for anatomical noise reduction in dual-energy chest digital tomosynthesis

NASA Astrophysics Data System (ADS)

Lee, D.; Kim, Y.-s.; Choi, S.; Lee, H.; Choi, S.; Kim, H.-J.

2016-01-01

Lung cancer is the leading cause of cancer death worldwide. Thus, early diagnosis is of considerable importance. For early screening of lung cancer, computed tomography (CT) has been used as the gold standard. Chest digital tomosynthesis (CDT) is a recently introduced modality for lung cancer screening with a relatively low radiation dose compared to CT. The dual energy material decomposition method has been proposed for better detection of pulmonary nodules by means of reducing anatomical noise. In this study, the possibility of material decomposition in CDT was tested by both a simulation study and an experimental study using a CDT prototype. The Geant4 application for tomographic emission (GATE) v6 and tungsten anode spectral model using interpolating polynomials (TASMIP) codes were used for the simulation study to create simulated phantom shapes consisting of five inner cylinders filled with different densities of bone and airequivalent materials. Furthermore, the CDT prototype system and human phantom chest were used for the experimental study. CDT scan in both the simulation and experimental studies was performed with linear movement and 21 projection images were obtained over a 30 degree angular range with a 1.5 degree angular interval. To obtain materialselective images, a projectionbased energy subtraction technique was applied to high and low energy images. The resultant simulation images showed that dual-energy reconstruction could achieve an approximately 32% higher contrast to noise ratio (CNR) in images and the difference in CNR value according to bone density was significant compared to single energy CDT. Additionally, image artifacts were effectively corrected in dual energy CDT simulation studies. Likewise the experimental study with dual energy produced clear images of lung fields and bone structure by removing unnecessary anatomical structures. Dual energy tomosynthesis is a new technique; therefore, there is little guidance regarding its integration into clinical practice and this study can be used to improve the diagnostic efficiency of lung field and spinal bone screening using CDT.

Implementation of laser speckle contrast analysis as connection kit for mobile phone for assessment of skin blood flow

NASA Astrophysics Data System (ADS)

Jakovels, Dainis; Saknite, Inga; Spigulis, Janis

2014-05-01

Laser speckle contrast analysis (LASCA) offers a non-contact, full-field, and real-time mapping of capillary blood flow and can be considered as an alternative method to Laser Doppler perfusion imaging. LASCA technique has been implemented in several commercial instruments. However, these systems are still too expensive and bulky to be widely available. Several optical techniques have found new implementations as connection kits for mobile phones thus offering low cost screening devices. In this work we demonstrate simple implementation of LASCA imaging technique as connection kit for mobile phone for primary low-cost assessment of skin blood flow. Stabilized 650 nm and 532 nm laser diode modules were used for LASCA illumination. Dual wavelength illumination could provide additional information about skin hemoglobin and oxygenation level. The proposed approach was tested for arterial occlusion and heat test. Besides, blood flow maps of injured and provoked skin were demonstrated.

Identification of Microorganisms by Modern Analytical Techniques.

PubMed

Buszewski, Bogusław; Rogowska, Agnieszka; Pomastowski, Paweł; Złoch, Michał; Railean-Plugaru, Viorica

2017-11-01

Rapid detection and identification of microorganisms is a challenging and important aspect in a wide range of fields, from medical to industrial, affecting human lives. Unfortunately, classical methods of microorganism identification are based on time-consuming and labor-intensive approaches. Screening techniques require the rapid and cheap grouping of bacterial isolates; however, modern bioanalytics demand comprehensive bacterial studies at a molecular level. Modern approaches for the rapid identification of bacteria use molecular techniques, such as 16S ribosomal RNA gene sequencing based on polymerase chain reaction or electromigration, especially capillary zone electrophoresis and capillary isoelectric focusing. However, there are still several challenges with the analysis of microbial complexes using electromigration technology, such as uncontrolled aggregation and/or adhesion to the capillary surface. Thus, an approach using capillary electrophoresis of microbial aggregates with UV and matrix-assisted laser desorption ionization time-of-flight MS detection is presented.

Machine-Learning Techniques Applied to Antibacterial Drug Discovery

PubMed Central

Durrant, Jacob D.; Amaro, Rommie E.

2014-01-01

The emergence of drug-resistant bacteria threatens to catapult humanity back to the pre-antibiotic era. Even now, multi-drug-resistant bacterial infections annually result in millions of hospital days, billions in healthcare costs, and, most importantly, tens of thousands of lives lost. As many pharmaceutical companies have abandoned antibiotic development in search of more lucrative therapeutics, academic researchers are uniquely positioned to fill the resulting vacuum. Traditional high-throughput screens and lead-optimization efforts are expensive and labor intensive. Computer-aided drug discovery techniques, which are cheaper and faster, can accelerate the identification of novel antibiotics in an academic setting, leading to improved hit rates and faster transitions to pre-clinical and clinical testing. The current review describes two machine-learning techniques, neural networks and decision trees, that have been used to identify experimentally validated antibiotics. We conclude by describing the future directions of this exciting field. PMID:25521642

Large field of view, fast and low dose multimodal phase-contrast imaging at high x-ray energy.

PubMed

Astolfo, Alberto; Endrizzi, Marco; Vittoria, Fabio A; Diemoz, Paul C; Price, Benjamin; Haig, Ian; Olivo, Alessandro

2017-05-19

X-ray phase contrast imaging (XPCI) is an innovative imaging technique which extends the contrast capabilities of 'conventional' absorption based x-ray systems. However, so far all XPCI implementations have suffered from one or more of the following limitations: low x-ray energies, small field of view (FOV) and long acquisition times. Those limitations relegated XPCI to a 'research-only' technique with an uncertain future in terms of large scale, high impact applications. We recently succeeded in designing, realizing and testing an XPCI system, which achieves significant steps toward simultaneously overcoming these limitations. Our system combines, for the first time, large FOV, high energy and fast scanning. Importantly, it is capable of providing high image quality at low x-ray doses, compatible with or even below those currently used in medical imaging. This extends the use of XPCI to areas which were unpractical or even inaccessible to previous XPCI solutions. We expect this will enable a long overdue translation into application fields such as security screening, industrial inspections and large FOV medical radiography - all with the inherent advantages of the XPCI multimodality.

New aspects relating to the behaviour of composites and adhesives in space

NASA Technical Reports Server (NTRS)

Carpenter, A.

1991-01-01

Some of the specialized testing procedures performed at the JPL Molecular Contamination Investigation Facility for the WideField Planetary Camera II (WFPC II) program for the screening of polymeric materials for outgassing properties are described. For WFPC II, a science performance goal of 1-percent photometric accuracy at 1470 A over an extended time (at least 30 days) has been established. Utilization of the newest technology using CCD detectors poses even more stringent requirements. Test results are presented, and data reduction and modeling techniques are discussed.

Development of scanning holographic display using MEMS SLM

NASA Astrophysics Data System (ADS)

Takaki, Yasuhiro

2016-10-01

Holography is an ideal three-dimensional (3D) display technique, because it produces 3D images that naturally satisfy human 3D perception including physiological and psychological factors. However, its electronic implementation is quite challenging because ultra-high resolution is required for display devices to provide sufficient screen size and viewing zone. We have developed holographic display techniques to enlarge the screen size and the viewing zone by use of microelectromechanical systems spatial light modulators (MEMS-SLMs). Because MEMS-SLMs can generate hologram patterns at a high frame rate, the time-multiplexing technique is utilized to virtually increase the resolution. Three kinds of scanning systems have been combined with MEMS-SLMs; the screen scanning system, the viewing-zone scanning system, and the 360-degree scanning system. The screen scanning system reduces the hologram size to enlarge the viewing zone and the reduced hologram patterns are scanned on the screen to increase the screen size: the color display system with a screen size of 6.2 in. and a viewing zone angle of 11° was demonstrated. The viewing-zone scanning system increases the screen size and the reduced viewing zone is scanned to enlarge the viewing zone: a screen size of 2.0 in. and a viewing zone angle of 40° were achieved. The two-channel system increased the screen size to 7.4 in. The 360-degree scanning increases the screen size and the reduced viewing zone is scanned circularly: the display system having a flat screen with a diameter of 100 mm was demonstrated, which generates 3D images viewed from any direction around the flat screen.

Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Xueyun; Wojcik, Roza; Zhang, Xing

Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. IMS alone is useful, but its coupling with mass spectrometry (MS) and front-end separations has been extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information in biological and environmental sample analyses. Multiple studies in disease screening and environmental evaluations have even shown these IMS-based multidimensional separations extract information not possible with each technique individually. This review highlights 3-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography (GC),more » supercritical fluid chromatography (SFC), liquid chromatography (LC), solid phase extractions (SPE), capillary electrophoresis (CE), field asymmetric ion mobility spectrometry (FAIMS), and microfluidic devices. The origination, current state, various applications, and future capabilities for these multidimensional approaches are described to provide insight into the utility and potential of each technique.« less

Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

NASA Astrophysics Data System (ADS)

Jayanthy, A. K.; Sujatha, N.; Reddy, M. Ramasubba; Narayanamoorthy, V. B.

2014-03-01

Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management.

Breast imaging. A practical look at its capabilities and its limitations.

PubMed

Clark, R; Nemec, L; Love, N

1992-10-01

The film-screen technique is evolving as the standard for mammography. Sonography is the only other method that currently has a defined role in breast imaging. Mammography should be performed at facilities that have received American College of Radiology accreditation or its equivalent, because technical quality assurance is an important part of mammographic practice. Interpretive quality may be assured by outcome audits performed by mammography facilities. Primary care physicians are best suited to encouraging eligible women to undergo screening studies and should consider these recommendations: Refer patients for screening mammography to accredited facilities according to established guidelines. Educate patients about the need for regular screening. Provide annual breast physical examination. Refresh your knowledge on breast health and the techniques of physical examination if necessary. Teach patients breast self-examination techniques. Demand low-cost, high-quality screening mammography; be aware of local variability of charges and quality.

Non-visual Web Browsing: Beyond Web Accessibility

PubMed Central

Ramakrishnan, I.V.; Ashok, Vikas

2017-01-01

People with vision impairments typically use screen readers to browse the Web. To facilitate non-visual browsing, web sites must be made accessible to screen readers, i.e., all the visible elements in the web site must be readable by the screen reader. But even if web sites are accessible, screen-reader users may not find them easy to use and/or easy to navigate. For example, they may not be able to locate the desired information without having to listen to a lot of irrelevant contents. These issues go beyond web accessibility and directly impact web usability. Several techniques have been reported in the accessibility literature for making the Web usable for screen reading. This paper is a review of these techniques. Interestingly, the review reveals that understanding the semantics of the web content is the overarching theme that drives these techniques for improving web usability. PMID:29202137

Non-visual Web Browsing: Beyond Web Accessibility.

PubMed

Ramakrishnan, I V; Ashok, Vikas; Billah, Syed Masum

2017-07-01

People with vision impairments typically use screen readers to browse the Web. To facilitate non-visual browsing, web sites must be made accessible to screen readers, i.e., all the visible elements in the web site must be readable by the screen reader. But even if web sites are accessible, screen-reader users may not find them easy to use and/or easy to navigate. For example, they may not be able to locate the desired information without having to listen to a lot of irrelevant contents. These issues go beyond web accessibility and directly impact web usability. Several techniques have been reported in the accessibility literature for making the Web usable for screen reading. This paper is a review of these techniques. Interestingly, the review reveals that understanding the semantics of the web content is the overarching theme that drives these techniques for improving web usability.

Fecal Molecular Markers for Colorectal Cancer Screening

PubMed Central

Kanthan, Rani; Senger, Jenna-Lynn; Kanthan, Selliah Chandra

2012-01-01

Despite multiple screening techniques, including colonoscopy, flexible sigmoidoscopy, radiological imaging, and fecal occult blood testing, colorectal cancer remains a leading cause of death. As these techniques improve, their sensitivity to detect malignant lesions is increasing; however, detection of precursor lesions remains problematic and has generated a lack of general acceptance for their widespread usage. Early detection by an accurate, noninvasive, cost-effective, simple-to-use screening technique is central to decreasing the incidence and mortality of this disease. Recent advances in the development of molecular markers in faecal specimens are encouraging for its use as a screening tool. Genetic mutations and epigenetic alterations that result from the carcinogenetic process can be detected by coprocytobiology in the colonocytes exfoliated from the lesion into the fecal matter. These markers have shown promising sensitivity and specificity in the detection of both malignant and premalignant lesions and are gaining popularity as a noninvasive technique that is representative of the entire colon. In this paper, we summarize the genetic and epigenetic fecal molecular markers that have been identified as potential targets in the screening of colorectal cancer. PMID:22969796

Anchoring protein crystals to mounting loops with hydrogel using inkjet technology.

PubMed

Shinoda, Akira; Tanaka, Yoshikazu; Yao, Min; Tanaka, Isao

2014-11-01

X-ray crystallography is an important technique for structure-based drug discovery, mainly because it is the only technique that can reveal whether a ligand binds to the target protein as well as where and how it binds. However, ligand screening by X-ray crystallography involves a crystal-soaking experiment, which is usually performed manually. Thus, the throughput is not satisfactory for screening large numbers of candidate ligands. In this study, a technique to anchor protein crystals to mounting loops by using gel and inkjet technology has been developed; the method allows soaking of the mounted crystals in ligand-containing solution. This new technique may assist in the design of a fully automated drug-screening pipeline.

Calibrated LCD/TFT stimulus presentation for visual psychophysics in fMRI.

PubMed

Strasburger, H; Wüstenberg, T; Jäncke, L

2002-11-15

Standard projection techniques using liquid crystal (LCD) or thin-film transistor (TFT) technology show drastic distortions in luminance and contrast characteristics across the screen and across grey levels. Common luminance measurement and calibration techniques are not applicable in the vicinity of MRI scanners. With the aid of a fibre optic, we measured screen luminances for the full space of screen position and image grey values and on that basis developed a compensation technique that involves both luminance homogenisation and position-dependent gamma correction. By the technique described, images displayed to a subject in functional MRI can be specified with high precision by a matrix of desired luminance values rather than by local grey value.

Review of the Draw a Person: Screening Procedure for Emotional Disturbance.

ERIC Educational Resources Information Center

Trevisan, Michael S.

1996-01-01

The Draw a Person: Screening Procedures for Emotional Disturbance (DAP:SPED) is a projective technique used in the initial assessment of children suffering from emotional problems, and unlike most projective techniques, features sound psychometric development. (Author)

Fully-Automated High-Throughput NMR System for Screening of Haploid Kernels of Maize (Corn) by Measurement of Oil Content

PubMed Central

Xu, Xiaoping; Huang, Qingming; Chen, Shanshan; Yang, Peiqiang; Chen, Shaojiang; Song, Yiqiao

2016-01-01

One of the modern crop breeding techniques uses doubled haploid plants that contain an identical pair of chromosomes in order to accelerate the breeding process. Rapid haploid identification method is critical for large-scale selections of double haploids. The conventional methods based on the color of the endosperm and embryo seeds are slow, manual and prone to error. On the other hand, there exists a significant difference between diploid and haploid seeds generated by high oil inducer, which makes it possible to use oil content to identify the haploid. This paper describes a fully-automated high-throughput NMR screening system for maize haploid kernel identification. The system is comprised of a sampler unit to select a single kernel to feed for measurement of NMR and weight, and a kernel sorter to distribute the kernel according to the measurement result. Tests of the system show a consistent accuracy of 94% with an average screening time of 4 seconds per kernel. Field test result is described and the directions for future improvement are discussed. PMID:27454427

Bias stress in PDI-CN2 and P3HT studied with Kelvin Probe Force Microscopy

NASA Astrophysics Data System (ADS)

Cao, Minxuan; Moscatello, Jason; Castaneda, Chloe; Xue, Binglan; Usluer, Ozlem; Briseno, Alejandro; Aidala, Katherine

We have developed a technique that uses scanning probe microscopy (SPM) to study the real-time injection and extraction of charge carriers in organic semiconductor devices. We investigate PDI-CN2 and P3HT in a back gate field effect transistor geometry with gold electrodes. By positioning the SPM tip at an individual location and using Kelvin probe microscopy to record the potential over time, we can record how the charge carriers respond to changing the gate voltage while the source and drain electrodes are grounded. We see relatively fast screening when carriers are injected into the film. The screening is slower when carriers must escape from traps to exit the film. By incrementally stepping the gate voltage, we can probe different trap depths. By repeating the measurement, we observe the development of longer lived trap states, shown by the longer time recorded to fully screen the gate voltage. This work is supported by NSF Grant DMR-0955348, and the Center for Heirarchical Manufacturing at the University of Massachusetts, Amherst (NSF CMMI-1025020).

Methods for investigating biosurfactants and bioemulsifiers: a review.

PubMed

Satpute, Surekha K; Banpurkar, Arun G; Dhakephalkar, Prashant K; Banat, Ibrahim M; Chopade, Balu A

2010-06-01

Microorganisms produce biosurfactant (BS)/bioemulsifier (BE) with wide structural and functional diversity which consequently results in the adoption of different techniques to investigate these diverse amphiphilic molecules. This review aims to compile information on different microbial screening methods, surface active products extraction procedures, and analytical terminologies used in this field. Different methods for screening microbial culture broth or cell biomass for surface active compounds production are also presented and their possible advantages and disadvantages highlighted. In addition, the most common methods for purification, detection, and structure determination for a wide range of BS and BE are introduced. Simple techniques such as precipitation using acetone, ammonium sulphate, solvent extraction, ultrafiltration, ion exchange, dialysis, ultrafiltration, lyophilization, isoelectric focusing (IEF), and thin layer chromatography (TLC) are described. Other more elaborate techniques including high pressure liquid chromatography (HPLC), infra red (IR), gas chromatography-mass spectroscopy (GC-MS), nuclear magnetic resonance (NMR), and fast atom bombardment mass spectroscopy (FAB-MS), protein digestion and amino acid sequencing are also elucidated. Various experimental strategies including static light scattering and hydrodynamic characterization for micelles have been discussed. A combination of various analytical methods are often essential in this area of research and a numbers of trials and errors to isolate, purify and characterize various surface active agents are required. This review introduces the various methodologies that are indispensable for studying biosurfactants and bioemulsifiers.

Analytical Validation of a Portable Mass Spectrometer Featuring Interchangeable, Ambient Ionization Sources for High Throughput Forensic Evidence Screening

NASA Astrophysics Data System (ADS)

Lawton, Zachary E.; Traub, Angelica; Fatigante, William L.; Mancias, Jose; O'Leary, Adam E.; Hall, Seth E.; Wieland, Jamie R.; Oberacher, Herbert; Gizzi, Michael C.; Mulligan, Christopher C.

2017-06-01

Forensic evidentiary backlogs are indicative of the growing need for cost-effective, high-throughput instrumental methods. One such emerging technology that shows high promise in meeting this demand while also allowing on-site forensic investigation is portable mass spectrometric (MS) instrumentation, particularly that which enables the coupling to ambient ionization techniques. While the benefits of rapid, on-site screening of contraband can be anticipated, the inherent legal implications of field-collected data necessitates that the analytical performance of technology employed be commensurate with accepted techniques. To this end, comprehensive analytical validation studies are required before broad incorporation by forensic practitioners can be considered, and are the focus of this work. Pertinent performance characteristics such as throughput, selectivity, accuracy/precision, method robustness, and ruggedness have been investigated. Reliability in the form of false positive/negative response rates is also assessed, examining the effect of variables such as user training and experience level. To provide flexibility toward broad chemical evidence analysis, a suite of rapidly-interchangeable ion sources has been developed and characterized through the analysis of common illicit chemicals and emerging threats like substituted phenethylamines. [Figure not available: see fulltext.

Diagnosis of uterine cervix cancer using Müller polarimetry: a comparison with histopathology

NASA Astrophysics Data System (ADS)

Rehbinder, Jean; Deby, Stanislas; Haddad, Huda; Teig, Benjamin; Nazac, André; Pierangelo, Angelo; Moreau, François

2015-07-01

Today around 275000 women a year in the world keep dying from the cancer of uterine cervix due to the difficulty to meet the logistic requirements of an organized screening in the developing world. Polarimetric imaging is a new promising technique with a tremendous potential for applications in biomedical diagnostics: it is sensitive to slight morphological changes in tissues, can provide wide field images for the screening and requires light sources such as a LED for example. This work intends to characterize the polarimetric response of the uterine cervix in its healthy and pathological states. An extensive series of ex-vivo measurements is in progress the Kremlin Bicêtre hospital near Paris using an imaging multispectral Mueller polarimeter in backscattering configuration. The goal of this study is to evaluate the performances of polarimetric imaging technique in terms of sensitivity and specificity for the detection of healthy epithelia (Healthy Squamous epithelium and Malpighian Metaplasia) with respect to the diagnosis provided by pathologists from histology slides as the "gold standard". We show that, at λ=550nm, performances as high as 62% sensitivity and 64% specificity are achieved by optimizing a simple threshold on the scalar retardance values.

PTR-ToF-MS Coupled with an Automated Sampling System and Tailored Data Analysis for Food Studies: Bioprocess Monitoring, Screening and Nose-space Analysis.

PubMed

Capozzi, Vittorio; Yener, Sine; Khomenko, Iuliia; Farneti, Brian; Cappellin, Luca; Gasperi, Flavia; Scampicchio, Matteo; Biasioli, Franco

2017-05-11

Proton Transfer Reaction (PTR), combined with a Time-of-Flight (ToF) Mass Spectrometer (MS) is an analytical approach based on chemical ionization that belongs to the Direct-Injection Mass Spectrometric (DIMS) technologies. These techniques allow the rapid determination of volatile organic compounds (VOCs), assuring high sensitivity and accuracy. In general, PTR-MS requires neither sample preparation nor sample destruction, allowing real time and non-invasive analysis of samples. PTR-MS are exploited in many fields, from environmental and atmospheric chemistry to medical and biological sciences. More recently, we developed a methodology based on coupling PTR-ToF-MS with an automated sampler and tailored data analysis tools, to increase the degree of automation and, consequently, to enhance the potential of the technique. This approach allowed us to monitor bioprocesses (e.g. enzymatic oxidation, alcoholic fermentation), to screen large sample sets (e.g. different origins, entire germoplasms) and to analyze several experimental modes (e.g. different concentrations of a given ingredient, different intensities of a specific technological parameter) in terms of VOC content. Here, we report the experimental protocols exemplifying different possible applications of our methodology: i.e. the detection of VOCs released during lactic acid fermentation of yogurt (on-line bioprocess monitoring), the monitoring of VOCs associated with different apple cultivars (large-scale screening), and the in vivo study of retronasal VOC release during coffee drinking (nosespace analysis).

Influence of clamping plate permeability and metal screen structures on three-dimensional magnetic field and eddy current loss in end region of a turbo-generator by numerical analysis

NASA Astrophysics Data System (ADS)

Likun, Wang; Weili, Li; Yi, Xue; Chunwei, Guan

2013-11-01

A significant problem of turbogenerators on complex end structures is overheating of local parts caused by end losses in the end region. Therefore, it is important to investigate the 3-D magnetic field and eddy current loss in the end. In end region of operating large turbogenerator at thermal power plants, magnetic leakage field distribution is complex. In this paper, a 3-D mathematical model used for the calculation of the electromagnetic field in the end region of large turbo-generators is given. The influence of spatial locations of end structures, the actual shape and material of end windings, clamping plate, and copper screen are considered. Adopting the time-step finite element (FE) method and taking the nonlinear characteristics of the core into consideration, a 3-D transient magnetic field is calculated. The objective of this paper is to investigate the influence of clamping plate permeability and metal screen structures on 3-D electromagnetic field distribution and eddy current loss in end region of a turbo-generator. To reduce the temperature of copper screen, a hollow metal screen is proposed. The eddy current loss, which is gained from the 3D transient magnetic field, is used as heat source for the thermal field of end region. The calculated temperatures are compared with test data.

Use of psi(alpha)-ETOs in the unified treatment of electronic attraction, electric field and electric field gradient multicenter integrals of screened Coulomb potentials over Slater orbitals.

PubMed

Guseinov, Israfil

2004-02-01

In this study, using complete orthonormal sets of Psi(alpha)-ETOs (where alpha=1, 0, -1, -2, ...) introduced by the author, a large number of series expansion formulae for the multicenter electronic attraction (EA), electric field (EF) and electric field gradient (EFG) integrals of the Yukawa-like screened Coulomb potentials (SCPs) is presented through the new central and noncentral potentials and the overlap integrals with the same screening constants. The final results obtained are valid for arbitrary locations of STOs and their parameters.

FY02 CBNP Annual Report Input: Bioinformatics Support for CBNP Research and Deployments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Slezak, T; Wolinsky, M

2002-10-31

The events of FY01 dynamically reprogrammed the objectives of the CBNP bioinformatics support team, to meet rapidly-changing Homeland Defense needs and requests from other agencies for assistance: Use computational techniques to determine potential unique DNA signature candidates for microbial and viral pathogens of interest to CBNP researcher and to our collaborating partner agencies such as the Centers for Disease Control and Prevention (CDC), U.S. Department of Agriculture (USDA), Department of Defense (DOD), and Food and Drug Administration (FDA). Develop effective electronic screening measures for DNA signatures to reduce the cost and time of wet-bench screening. Build a comprehensive system formore » tracking the development and testing of DNA signatures. Build a chain-of-custody sample tracking system for field deployment of the DNA signatures as part of the BASIS project. Provide computational tools for use by CBNP Biological Foundations researchers.« less

Recent advances of liquid chromatography-(tandem) mass spectrometry in clinical and forensic toxicology.

PubMed

Peters, Frank T

2011-01-01

Liquid chromatography (LC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) has become increasingly important in clinical and forensic toxicology as well as doping control and is now a robust and reliable technique for routine analysis in these fields. In recent years, methods for LC-MS(/MS)-based systematic toxicological analysis using triple quadrupole or ion trap instruments have been considerably improved and a new screening approach based on high-resolution MS analysis using benchtop time-of-flight MS instruments has been developed. Moreover, many applications for so-called multi-target screening and/or quantification of drugs, poisons, and or their metabolites in various biomatrices have been published. The present paper will provide an overview and discuss these recent developments focusing on the literature published after 2006. Copyright © 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Updates in the Management of Hepatocellular Carcinoma

PubMed Central

Frenette, Catherine

2011-01-01

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death, and its increasing incidence worldwide is a cause for concern. Fortunately, advances in diagnostic and therapeutic approaches have contributed to earlier detection and treatment. As cancer epidemiology studies continue to elucidate the natural history of liver diseases, greater understanding of HCC has led to improved risk stratification and earlier enrollment of high-risk patients in cancer screening and surveillance programs. Improved survival rates among HCC patients also reflect significant advances in available treatment options. Advances in surgical techniques are pushing the boundaries of resection for localized disease, and progress in the field of transplantation has led to refinements in listing criteria and improved post-transplantation outcomes. The evolving field of locoregional therapies—including percutaneous ablation and transarterial chemoembolization—continues to provide novel therapeutic options that can be used in place of, or in addition to, surgical approaches. Recent advances in systemic multikinase inhibitor therapies have also demonstrated significant benefits for advanced-stage disease, and these therapies also show promise as adjuvant treatments for earlier-stage disease. This article provides an update on the management of HCC, with a focus on revised guidelines for screening and an in-depth discussion of emerging novel therapies. PMID:21346848

Airport testing an explosives detection portal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhykerd, C.; Linker, K.; Hannum, D.

1998-08-01

At the direction of the US Congress, following the Pan Am 103 and TWA 800 crashes, the Federal Aviation Administration funded development of non-invasive techniques to screen airline passengers for explosives. Such an explosives detection portal, developed at Sandia National Laboratories, was field tested at the Albuquerque International airport in September 1997. During the 2-week field trial, 2,400 passengers were screened and 500 surveyed. Throughput, reliability, maintenance and sensitivity were studied. Follow-up testing at Sandia and at Idaho National Engineering and Environmental Laboratory was conducted. A passenger stands in the portal for five seconds while overhead fans blow air overmore » his body. Any explosive vapors or dislodged particles are collected in vents at the feet. Explosives are removed from the air in a preconcentrator and subsequently directed into an ion mobility spectrometer for detection. Throughput measured 300 passengers per hour. The non-invasive portal can detect subfingerprint levels of explosives residue on clothing. A survey of 500 passengers showed a 97% approval rating, with 99% stating that such portals, if effective, should be installed in airports to improve security. Results of the airport test, as well as operational issues, are discussed.« less

Screening fungicides for use in fish culture: Evaluation of the agar plug transfer, cellophane transfer, and agar dilution methods

USGS Publications Warehouse

Bailey, Tom A.

1983-01-01

The reliability, reproducibility, and usefulness of three screening methods -- the cellophane transfer, the agar plug transfer, and the agar dilution -- to screen aquatic fungicides were evaluated. Achlya flagellata and Saprolegnia hypogyna were exposed to 1, 10, and 100 mg/L of malachite green to test each method. The cellophane transfer and agar plug transfer techniques had similar reliability and reproducibility in rating fungicidal activity, and were both superior to the agar dilution technique. The agar plug transfer and agar dilution techniques adequately projected in vivo activity of malachite green, but the cellophane transfer technique overestimated its activity. Overall, the agar plug transfer technique most accurately rated the activity of malachite green and was the easiest test to perform. It therefore appears to be the method of choice for testing aquatic fungicides.

Real time 3D photometry

NASA Astrophysics Data System (ADS)

Fernandez-Balbuena, A. A.; Vazquez-Molini, D.; García-Botella, A.; Romo, J.; Serrano, Ana

2017-09-01

The photometry and radiometry measurement is a well-developed field. The necessity of measuring optical systems performance involves the use of several techniques like Gonio-photometry. The Gonio photometers are a precise measurement tool that is used in the lighting area like office, luminaire head car lighting, concentrator /collimator measurement and all the designed and fabricated optical systems that works with light. There is one disadvantage in this kind of measurements that obtain the intensity polar curves and the total flux of the optical system. In the industry, there are good Gonio photometers that are precise and reliable but they are very expensive and the measurement time is long. In industry the cost can be of minor importance but measuring time that is around 30 minutes is of major importance due to trained staff cost. We have designed a system to measure photometry in real time; it consists in a curved screen to get a huge measurement angle and a CCD. The system to be measured projects light onto the screen and the CCD records a video of the screen obtaining an image of the projected profile. A complex calibration permits to trace screen data (x,y,z) to intensity polar curve (I,αγ). This intensity is obtained in candels (cd) with an image + processing time below one second.

Optimizing ultrafast wide field-of-view illumination for high-throughput multi-photon imaging and screening of mutant fluorescent proteins

NASA Astrophysics Data System (ADS)

Stoltzfus, Caleb; Mikhailov, Alexandr; Rebane, Aleksander

2017-02-01

Fluorescence induced by 1wo-photon absorption (2PA) and three-photon absorption (3PA) is becoming an increasingly important tool for deep-tissue microscopy, especially in conjunction with genetically-encoded functional probes such as fluorescent proteins (FPs). Unfortunately, the efficacy of the multi-photon excitation of FPs is notoriously low, and because relations between a biological fluorophore's nonlinear-optical properties and its molecular structure are inherently complex, there are no practical avenues available that would allow boosting the performance of current FPs. Here we describe a novel method, where we apply directed evolution to optimize the 2PA properties of EGFP. Key to the success of this approach consists in high-throughput screening of mutants that would allow selection of variants with promising 2PA and 3PA properties in a broad near-IR excitation range of wavelength. For this purpose, we construct and test a wide field-of-view (FOV), femtosecond imaging system that we then use to quantify the multi-photon excited fluorescence in the 550- 1600 nm range of tens of thousands of E. coli colonies expressing randomly mutated FPs in a standard 10 cm diameter Petri dish configuration. We present a quantitative analysis of different factors that are currently limiting the maximum throughput of the femtosecond multi-photon screening techniques and also report on quantitative measurement of absolute 2PA and 3PA cross sections spectra.

Use of Second Generation Coated Conductors for Efficient Shielding of dc Magnetic Fields (Postprint)

DTIC Science & Technology

2010-07-15

layer of superconducting film, can attenuate an external magnetic field of up to 5 mT by more than an order of magnitude. For comparison purposes...appears to be especially promising for the realization of large scale high-Tc superconducting screens. 15. SUBJECT TERMS magnetic screens, current...realization of large scale high-Tc superconducting screens. © 2010 American Institute of Physics. doi:10.1063/1.3459895 I. INTRODUCTION Magnetic screening

Influence of quantum well inhomogeneities on absorption, spontaneous emission, photoluminescence decay time, and lasing in polar InGaN quantum wells emitting in the blue-green spectral region

NASA Astrophysics Data System (ADS)

Gladysiewicz, M.; Kudrawiec, R.; Syperek, M.; Misiewicz, J.; Siekacz, M.; Cywinski, G.; Khachapuridze, A.; Suski, T.; Skierbiszewski, C.

2014-06-01

It is shown that in polar InGaN QWs emitting in the blue-green spectral region a Stokes shift between spontaneous emission (SE) and optical transition observed in contactless electroreflectance (CER) spectrum (absorption-like technique) can be observed even at room temperature, despite the fact that the SE is not associated with localized states. Time resolved photoluminescence measurements clearly confirm that the SE is strongly localized at low temperatures whereas at room temperature the carrier localization disappears and the SE can be attributed to the fundamental transition in this QW. The Stokes shift is observed in this QW system because of the large built-in electric field, i.e., the CER transition is a superposition of all optical transitions with non-zero electron-hole overlap integrals and, therefore, the energy of this transition does not correspond to the fundamental transition of InGaN QW. Lasing from this QW has been observed at the wavelength of 475 nm, whereas the SE was observed at 500 nm. The 25 nm shift between the lasing and SE is observed because of a screening of the built-in electric field by photogenerated carriers. However, our analysis shows that the built-in electric field inside the InGaN QW region is not fully screened under the lasing conditions.

ELECTROCHEMICAL TECHNIQUE FOR TNT USING DISPOSABLE SCREEN-PRINTED ELECTRODE

EPA Science Inventory

Screen-printed thick film electrodes are demonstrated as voltammetric sensors for measurement of 2,4,6-trinitrotoluene (TNT). The square wave voltammetric (SWV) scan technique is used to measure TNT in as little as 50 uL sample volumes. This electrochemical assay is coupled ...

Direct-current arc and alternating-current spark emission spectrographic field methods for the semiquantitative analysis of geologic materials

USGS Publications Warehouse

Grimes, D.J.; Marranzino, A.P.

1968-01-01

Two spectrographic methods are used in mobile field laboratories of the U. S. Geological Survey. In the direct-current arc method, the ground sample is mixed with graphite powder, packed into an electrode crater, and burned to completion. Thirty elements are determined. In the spark method, the sample, ground to pass a 150-mesh screen, is digested in hydrofluoric acid followed by evaporation to dryness and dissolution in aqua regia. The solution is fed into the spark gap by means of a rotating-disk electrode arrangement and is excited with an alternating-current spark discharge. Fourteen elements are determined. In both techniques, light is recorded on Spectrum Analysis No. 1, 35-millimeter film, and the spectra are compared visually with those of standard films.

Recent advancements in low cost solar cell processing

NASA Technical Reports Server (NTRS)

Ralph, E. L.

1975-01-01

A proof-of-concept solar cell process has been developed that is adaptable to automation. This involved the development of a new contact system, a new antireflection coating system, a drift field cell design and a new contoured surface treatment. All these processes are performed without the use of vacuum chambers and expensive masking techniques, thus providing the possibility of reduced costs by automation using conventional semiconductor processing machinery. The contacts were printed on the cells by conventional silk screen machinery. The P(+) back field was formed by diffusing in aluminum from a printed aluminum back contact. The antireflection coating was formed by spinning on and baking a TiO2-SiO2 glass film. Air-mass-zero efficiencies of over 10% were achieved using this completely vacuum-free process.

Introduction to Pharmaceutical Biotechnology, Volume 1; Basic techniques and concepts

NASA Astrophysics Data System (ADS)

Bhatia, Saurabh; Goli, Divakar

2018-05-01

Animal biotechnology is a broad field including polarities of fundamental and applied research, as well as DNA science, covering key topics of DNA studies and its recent applications. In Introduction to Pharmaceutical Biotechnology, DNA isolation procedures followed by molecular markers and screening methods of the genomic library are explained. Interesting areas like isolation, sequencing and synthesis of genes, with the broader coverage on synthesis of genes, are also described. The book begins with an introduction to biotechnology and its main branches, explaining both the basic science and the applications of biotechnology-derived pharmaceuticals, with special emphasis on their clinical use. It then moves on to historical development and scope of biotechnology with an overall review of early applications that scientists employed long before the field was defined.

Computer-Assisted Diagnosis of the Sleep Apnea-Hypopnea Syndrome: A Review

PubMed Central

Alvarez-Estevez, Diego; Moret-Bonillo, Vicente

2015-01-01

Automatic diagnosis of the Sleep Apnea-Hypopnea Syndrome (SAHS) has become an important area of research due to the growing interest in the field of sleep medicine and the costs associated with its manual diagnosis. The increment and heterogeneity of the different techniques, however, make it somewhat difficult to adequately follow the recent developments. A literature review within the area of computer-assisted diagnosis of SAHS has been performed comprising the last 15 years of research in the field. Screening approaches, methods for the detection and classification of respiratory events, comprehensive diagnostic systems, and an outline of current commercial approaches are reviewed. An overview of the different methods is presented together with validation analysis and critical discussion of the current state of the art. PMID:26266052

Chroma key without color restrictions based on asynchronous amplitude modulation of background illumination on retroreflective screens

NASA Astrophysics Data System (ADS)

Vidal, Borja; Lafuente, Juan A.

2016-03-01

A simple technique to avoid color limitations in image capture systems based on chroma key video composition using retroreflective screens and light-emitting diodes (LED) rings is proposed and demonstrated. The combination of an asynchronous temporal modulation onto the background illumination and simple image processing removes the usual restrictions on foreground colors in the scene. The technique removes technical constraints in stage composition, allowing its design to be purely based on artistic grounds. Since it only requires adding a very simple electronic circuit to widely used chroma keying hardware based on retroreflective screens, the technique is easily applicable to TV and filming studios.

The role of printing techniques for large-area dye sensitized solar cells

NASA Astrophysics Data System (ADS)

Mariani, Paolo; Vesce, Luigi; Di Carlo, Aldo

2015-10-01

The versatility of printing technologies and their intrinsic ability to outperform other techniques in large-area deposition gives scope to revolutionize the photovoltaic (PV) manufacturing field. Printing methods are commonly used in conventional silicon-based PVs to cover part of the production process. Screen printing techniques, for example, are applied to deposit electrical contacts on the silicon wafer. However, it is with the advent of third generation PVs that printing/coating techniques have been extensively used in almost all of the manufacturing processes. Among all the third generation PVs, dye sensitized solar cell (DSSC) technology has been developed up to commercialization levels. DSSCs and modules can be fabricated by adopting all of the main printing techniques on both rigid and flexible substrates. This allows an easy tuning of cell/module characteristics to the desired application. Transparency, colour, shape, layout and other DSSC’s features can be easily varied by changing the printing parameters and paste/ink formulations used in the printing process. This review focuses on large-area printing/coating technologies for the fabrication of DSSCs devices. The most used and promising techniques are presented underlining the process parameters and applications.

Solid-Phase Extraction Coupled to a Paper-Based Technique for Trace Copper Detection in Drinking Water.

PubMed

Quinn, Casey W; Cate, David M; Miller-Lionberg, Daniel D; Reilly, Thomas; Volckens, John; Henry, Charles S

2018-03-20

Metal contamination of natural and drinking water systems poses hazards to public and environmental health. Quantifying metal concentrations in water typically requires sample collection in the field followed by expensive laboratory analysis that can take days to weeks to obtain results. The objective of this work was to develop a low-cost, field-deployable method to quantify trace levels of copper in drinking water by coupling solid-phase extraction/preconcentration with a microfluidic paper-based analytical device. This method has the advantages of being hand-powered (instrument-free) and using a simple "read by eye" quantification motif (based on color distance). Tap water samples collected across Fort Collins, CO, were tested with this method and validated against ICP-MS. We demonstrate the ability to quantify the copper content of tap water within 30% of a reference technique at levels ranging from 20 to 500 000 ppb. The application of this technology, which should be sufficient as a rapid screening tool, can lead to faster, more cost-effective detection of soluble metals in water systems.

Non-contact, non-destructive, quantitative probing of interfacial trap sites for charge carrier transport at semiconductor-insulator boundary

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Wookjin; Miyakai, Tomoyo; Sakurai, Tsuneaki

The density of traps at semiconductor–insulator interfaces was successfully estimated using microwave dielectric loss spectroscopy with model thin-film organic field-effect transistors. The non-contact, non-destructive analysis technique is referred to as field-induced time-resolved microwave conductivity (FI-TRMC) at interfaces. Kinetic traces of FI-TRMC transients clearly distinguished the mobile charge carriers at the interfaces from the immobile charges trapped at defects, allowing both the mobility of charge carriers and the number density of trap sites to be determined at the semiconductor-insulator interfaces. The number density of defects at the interface between evaporated pentacene on a poly(methylmethacrylate) insulating layer was determined to be 10{supmore » 12 }cm{sup −2}, and the hole mobility was up to 6.5 cm{sup 2} V{sup −1} s{sup −1} after filling the defects with trapped carriers. The FI-TRMC at interfaces technique has the potential to provide rapid screening for the assessment of interfacial electronic states in a variety of semiconductor devices.« less

Investigating of the Field Emission Performance on Nano-Apex Carbon Fiber and Tungsten Tips

NASA Astrophysics Data System (ADS)

Mousa, Marwan S.; Alnawasreh, Shadi; Madanat, Mazen A.; Al-Rabadi, Anas N.

2015-10-01

Field electron emission measurements have been performed on carbon-based and tungsten microemitters. Several samples of both types of emitters with different apex radii have been obtained employing electrolytic etching techniques using sodium hydroxide (NaOH) solution with different molarities depending on the material used. A suitable, home-built, field electron microscope (FEM) with 10 mm tip to screen separation distance was used to electrically characterize the electron emitters. Measurements were carried out under ultra high vacuum (UHV) conditions with base pressure of 10-9 mbar. The current-voltage characteristics (I-V) presented as Fowler-Nordheim (FN) type plots, and field electron emission images have been recorded. In this work, initial comparison of the field electron emission performance of these micro and nanoemitters has been carried out, with the aim of obtaining a reliable, stable and long life powerful electron source. We compare the apex radii measured from the micrographs obtained from the SEM images to those extracted from the FN-type _I-V_plots for carbon fibers and tungsten tips.

Fabrication of a wettability-gradient surface on copper by screen-printing techniques

NASA Astrophysics Data System (ADS)

Huang, Ding-Jun; Leu, Tzong-Shyng

2015-08-01

In this study, a screen-printing technique is utilized to fabricate a wettability-gradient surface on a copper substrate. The pattern definitions on the copper surface were freely fabricated to define the regions with different wettabilities, for which the printing definition technique was developed as an alternative to the existing costly photolithography techniques. This fabrication process using screen printing in tandem with chemical modification methods can easily realize an excellent wettability-gradient surface with superhydrophobicity and superhydrophilicity. Surface analyses were performed to characterize conditions in some fabrication steps. A water droplet movement sequence is provided to clearly demonstrate the droplet-driving effectiveness of the fabricated gradient surface. The droplet-driving efficiency offers a promising solution for condensation heat transfer applications in the foreseeable future.

Screening effect in matrix graphene / SiC planar field emmiters

NASA Astrophysics Data System (ADS)

Jityaev, I. L.; Svetlichnyi, A. M.; Kolomiytsev, A. S.; Ageev, O. A.

2017-11-01

The paper describes simulation of matrix field emission nanostructures on the basis of graphene on a semi-insulating silicon carbide. The planar spike-type field emission cathodes were measured. The electric field distribution in an interelectrode gap of the emission structure was obtained. The models take into account the distance between cathode tops. Screening effect condition was detected in planar field emission structure and a way of eliminating was proposed.

Students as Technicians: Screening Newborns for Cystic Fibrosis

ERIC Educational Resources Information Center

Gusky, Sharon

2014-01-01

In this activity, freshman college students learn biotechnology techniques while playing the role of a laboratory technician. They perform simulations of three diagnostic tests used to screen newborns for cystic fibrosis. By performing an ELISA, a PCR analysis, and a conductivity test, students learn how biotechnology techniques can be used to…

Development of Droplet Microfluidics Enabling High-Throughput Single-Cell Analysis.

PubMed

Wen, Na; Zhao, Zhan; Fan, Beiyuan; Chen, Deyong; Men, Dong; Wang, Junbo; Chen, Jian

2016-07-05

This article reviews recent developments in droplet microfluidics enabling high-throughput single-cell analysis. Five key aspects in this field are included in this review: (1) prototype demonstration of single-cell encapsulation in microfluidic droplets; (2) technical improvements of single-cell encapsulation in microfluidic droplets; (3) microfluidic droplets enabling single-cell proteomic analysis; (4) microfluidic droplets enabling single-cell genomic analysis; and (5) integrated microfluidic droplet systems enabling single-cell screening. We examine the advantages and limitations of each technique and discuss future research opportunities by focusing on key performances of throughput, multifunctionality, and absolute quantification.

A Systematic Evaluation of Field-Based Screening Methods for the Assessment of Anterior Cruciate Ligament (ACL) Injury Risk.

PubMed

Fox, Aaron S; Bonacci, Jason; McLean, Scott G; Spittle, Michael; Saunders, Natalie

2016-05-01

Laboratory-based measures provide an accurate method to identify risk factors for anterior cruciate ligament (ACL) injury; however, these methods are generally prohibitive to the wider community. Screening methods that can be completed in a field or clinical setting may be more applicable for wider community use. Examination of field-based screening methods for ACL injury risk can aid in identifying the most applicable method(s) for use in these settings. The objective of this systematic review was to evaluate and compare field-based screening methods for ACL injury risk to determine their efficacy of use in wider community settings. An electronic database search was conducted on the SPORTDiscus™, MEDLINE, AMED and CINAHL databases (January 1990-July 2015) using a combination of relevant keywords. A secondary search of the same databases, using relevant keywords from identified screening methods, was also undertaken. Studies identified as potentially relevant were independently examined by two reviewers for inclusion. Where consensus could not be reached, a third reviewer was consulted. Original research articles that examined screening methods for ACL injury risk that could be undertaken outside of a laboratory setting were included for review. Two reviewers independently assessed the quality of included studies. Included studies were categorized according to the screening method they examined. A description of each screening method, and data pertaining to the ability to prospectively identify ACL injuries, validity and reliability, recommendations for identifying 'at-risk' athletes, equipment and training required to complete screening, time taken to screen athletes, and applicability of the screening method across sports and athletes were extracted from relevant studies. Of 1077 citations from the initial search, a total of 25 articles were identified as potentially relevant, with 12 meeting all inclusion/exclusion criteria. From the secondary search, eight further studies met all criteria, resulting in 20 studies being included for review. Five ACL-screening methods-the Landing Error Scoring System (LESS), Clinic-Based Algorithm, Observational Screening of Dynamic Knee Valgus (OSDKV), 2D-Cam Method, and Tuck Jump Assessment-were identified. There was limited evidence supporting the use of field-based screening methods in predicting ACL injuries across a range of populations. Differences relating to the equipment and time required to complete screening methods were identified. Only screening methods for ACL injury risk were included for review. Field-based screening methods developed for lower-limb injury risk in general may also incorporate, and be useful in, screening for ACL injury risk. Limited studies were available relating to the OSDKV and 2D-Cam Method. The LESS showed predictive validity in identifying ACL injuries, however only in a youth athlete population. The LESS also appears practical for community-wide use due to the minimal equipment and set-up/analysis time required. The Clinic-Based Algorithm may have predictive value for ACL injury risk as it identifies athletes who exhibit high frontal plane knee loads during a landing task, but requires extensive additional equipment and time, which may limit its application to wider community settings.

Stretching Screens and Imaginations.

ERIC Educational Resources Information Center

Douthwaite, Shelaugh

1983-01-01

Secondary students utilize a simplified technique to make silk screen prints, which can be printed onto T-shirts. The only materials needed from art suppliers are a few squeegees and a few yards of polyester screen mesh. (RM)

FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - INNOVATIVE TECHNOLOGY REPORT

EPA Science Inventory

This innovative technology evaluation report (ITER) presents information on the demonstration of the U.S. Environmental Protection Agency (EPA) Region 7 Superfund Field Analytical Screening Program (FASP) method for determining polychlorinated biphenyl (PCB) contamination in soil...

Detection of hazardous chemicals using field-portable Raman spectroscopy

NASA Astrophysics Data System (ADS)

Wright, Cherylyn W.; Harvey, Scott D.; Wright, Bob W.

2003-07-01

A major challenge confronting emergency response, border control, and other security-related functions is the accurate, rapid, and safe identification of potentially hazardous chemicals outside a laboratory environment. Raman spectroscopy is a rapid, non-intrusive technique that can be used to confidently identify many classes of hazardous and potentially explosive compounds based on molecular vibration information. Advances in instrumentation now allow reliable field - portable measurements to be made. Before the Raman technique can be effectively applied and be accepted within the scientific community, realistic studies must be performed to develop methods, define limitations, and rigorously evaluate its effectiveness. Examples of a variety of chemicals (including neat and diluted chemical warfare [CW] agents, a CW agent precursor, a biological warfare (BW)-related compound, an illicit drug, and explosives) identified using Raman spectroscopy in various types of containers and on surfaces are given, as well as results from a blind field test of 29 unknown samples which included CW agent precursors and/or degradation products, solvents associated with CW agent production, pesticides, explosives, and BW toxins (mostly mycotoxins). Additionally, results of experimental studies to evaluate the analysis of flammable organic solvents, propellants, military explosives, mixtures containing military explosives, shock-sensitive explosives, and gun powders are described with safety guidelines. Spectral masks for screening unknown samples for explosives and nerve agents are given.

Ultrahigh-resolution CT and DR scanner

NASA Astrophysics Data System (ADS)

DiBianca, Frank A.; Gupta, Vivek; Zou, Ping; Jordan, Lawrence M.; Laughter, Joseph S.; Zeman, Herbert D.; Sebes, Jeno I.

1999-05-01

A new technique called Variable-Resolution X-ray (VRX) detection that dramatically increases the spatial resolution in computed tomography (CT) and digital radiography (DR) is presented. The technique is based on a principle called 'projective compression' that allows the resolution element of a CT detector to scale with the subject or field size. For very large (40 - 50 cm) field sizes, resolution exceeding 2 cy/mm is possible and for very small fields, microscopy is attainable with resolution exceeding 100 cy/mm. Several effects that could limit the performance of VRX detectors are considered. Experimental measurements on a 16-channel, CdWO4 scintillator + photodiode test array yield a limiting MTF of 64 cy/mm (8(mu) ) in the highest-resolution configuration reported. Preliminary CT images have been made of small anatomical specimens and small animals using a storage phosphor screen in the VRX mode. Measured detector resolution of the CT projection data exceeds 20 cy/mm (less than 25 (mu) ); however, the final, reconstructed CT images produced thus far exhibit 10 cy/mm (50 (mu) ) resolution because of non-flatness of the storage phosphor plates, focal spot effects and the use of a rudimentary CT reconstruction algorithm. A 576-channel solid-state detector is being fabricated that is expected to achieve CT image resolution in excess of that of the 26-channel test array.

Nano-architectural Alterations in Mucus Layer Fecal Colonocytes in Field Carcinogenesis: Potential for Screening

PubMed Central

Roy, Hemant K.; Damania, Dhwanil P.; DelaCruz, Mart; Kunte, Dhananjay P.; Subramanian, Hariharan; Crawford, Susan E.; Tiwari, Ashish K.; Wali, Ramesh K.; Backman, Vadim

2013-01-01

Current fecal tests (occult blood, methylation, DNA mutations) target minute amounts of tumor products among a large amount of fecal material and thus have suboptimal performance. Our group has focused on exploiting field carcinogenesis as a modality to amplify the neoplastic signal. Specifically, we have demonstrated that endoscopically normal rectal brushings have striking nano-architectural alterations which are detectable utilizing a novel optical technique, partial wave spectroscopic microscopy (PWS). We therefore wished to translate this approach to a fecal assay. We examined mucus layer fecal colonocytes (MLFCs) at preneoplastic and neoplastic time-points (confirmed with rat colonoscopy) in the azoxymethane (AOM)-treated rat model and conducted PWS analysis to derive the nano-architectural parameter, disorder strength (Ld). We confirmed these results with studies in a genetic model (the Pirc rat). We demonstrated that MLFC appeared microscopically normal, consistent with field carcinogenesis. Ld was elevated at an early time point (5 weeks post-AOM injection, effect size = 0.40, p value = 0.024) and plateaued prior to adenoma formation (10 weeks post-AOM, effect size =0.66, p=0.001), with no dramatic increase once tumors developed. We replicated these data in the pre-neoplastic Pirc rat with an effect size in the MLFC that replicated the rectal brushings (increase versus age-matched controls of 62 versus 74%, respectively). We provide the first demonstration of a biophotonics approach to fecal assay. Furthermore, targeting the nano-architectural changes of field carcinogenesis rather than the detection of tumor products may provide a novel paradigm for colorectal cancer screening. PMID:23983085

Carrier Screening: Past, Present, and Future

PubMed Central

Bajaj, Komal; Gross, Susan J.

2014-01-01

To date, preconceptual and prenatal patients have been offered gene-by-gene, disorder-by-disorder carrier screening. Newer techniques allow screening of many disorders at one time. The goal of this review is to provide an overview of the current practice and future direction of carrier screening within the preconceptual/prenatal setting.

SU-E-J-158: Experimental Investigation of Proton Radiography Based On Time-Resolved Dose Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Testa, M; Paganetti, H; Lu, H-M

2014-06-01

Purpose: To use proton radiography for i) in-vivo range verification of the brain fields of medulloblastoma patients in order to reduce the exit dose to the cranial skin and thus the risk of permanent alopecia; ii) for performing patient specific optimization of the calibration from CT-Hounsfield units to proton relative stopping power in order to minimize uncertainties of proton rang Methods: We developed and tested a prototype proton radiography system based on a single-plane scintillation screen coupled with a fast CCD camera (1ms sampling rate, 0.29x0.29 mm{sup 2} pixel size, 30×30 cm{sup 2} field of view). The method is basedmore » on the principle that, for passively scattered beams, the radiological depth of any point in the plateau of a spread-out Bragg-Peak (SOBP) can be inferred from the time-pattern of the dose rate measurements. We performed detector characterization measurements using complex-shape homogeneous phantoms and an Alderson phanto Results: Detector characterization tests confirmed the robustness of the technique. The results of the phantom measurements are encouraging in terms of achievable accuracy of the water equivalent thickness. A technique to minimize the degradation of spatial resolution due to multiple Coulomb scattering is discussed. Our novel radiographic technique is rapid (100 ms) and simultaneous over the whole field. The dose required to produce one radiograph, with the current settings, is ∼3 cG Conclusion: The results obtained with this simple and innovative radiography method are promising and motivate further development of technique. The system requires only a single-plane 2D dosimeter and it uses the clinical beam for a fraction of second with low dose to the patient.« less

Accommodation measurements of horizontally scanning holographic display.

PubMed

Takaki, Yasuhiro; Yokouchi, Masahito

2012-02-13

Eye accommodation is considered to function properly for three-dimensional (3D) images generated by holography. We developed a horizontally scanning holographic display technique that enlarges both the screen size and viewing zone angle. A 3D image generated by this technique can be easily seen by both eyes. In this study, we measured the accommodation responses to a 3D image generated by the horizontally scanning holographic display technique that has a horizontal viewing zone angle of 14.6° and screen size of 4.3 in. We found that the accommodation responses to a 3D image displayed within 400 mm from the display screen were similar to those of a real object.

Supercritical fluid chromatography for lipid analysis in foodstuffs.

PubMed

Donato, Paola; Inferrera, Veronica; Sciarrone, Danilo; Mondello, Luigi

2017-01-01

The task of lipid analysis has always challenged separation scientists, and new techniques in chromatography were often developed for the separation of lipids; however, no single technique or methodology is yet capable of affording a comprehensive screening of all lipid species and classes. This review acquaints the role of supercritical fluid chromatography within the field of lipid analysis, from the early developed capillary separations based on pure CO 2 , to the most recent techniques employing packed columns under subcritical conditions, including the niche multidimensional techniques using supercritical fluids in at least one of the separation dimensions. A short history of supercritical fluid chromatography will be introduced first, from its early popularity in the late 1980s, to the sudden fall and oblivion until the last decade, experiencing a regain of interest within the chromatographic community. Afterwards, the subject of lipid nomenclature and classification will be briefly dealt with, before discussing the main applications of supercritical fluid chromatography for food analysis, according to the specific class of lipids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved reconstruction and sensing techniques for personnel screening in three-dimensional cylindrical millimeter-wave portal scanning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandes, Justin L.; Rappaport, Carey M.; Sheen, David M.

2011-05-01

The cylindrical millimeter-wave imaging technique, developed at Pacific Northwest National Laboratory (PNNL) and commercialized by L-3 Communications/Safeview in the ProVision system, is currently being deployed in airports and other high security locations to meet person-borne weapon and explosive detection requirements. While this system is efficient and effective in its current form, there are a number of areas in which the detection performance may be improved through using different reconstruction algorithms and sensing configurations. PNNL and Northeastern University have teamed together to investigate higher-order imaging artifacts produced by the current cylindrical millimeter-wave imaging technique using full-wave forward modeling and laboratory experimentation.more » Based on imaging results and scattered field visualizations using the full-wave forward model, a new imaging system is proposed. The new system combines a multistatic sensor configuration with the generalized synthetic aperture focusing technique (GSAFT). Initial results show an improved ability to image in areas of the body where target shading, specular and higher-order reflections cause images produced by the monostatic system difficult to interpret.« less

Technique for writing of fiber Bragg gratings over or near preliminary formed macro-structure defects in silica optical fibers

NASA Astrophysics Data System (ADS)

Evtushenko, Alexander S.; Faskhutdinov, Lenar M.; Kafarova, Anastasia M.; Kazakov, Vadim S.; Kuznetzov, Artem A.; Minaeva, Alina Yu.; Sevruk, Nikita L.; Nureev, Ilnur I.; Vasilets, Alexander A.; Andreev, Vladimir A.; Morozov, Oleg G.; Burdin, Vladimir A.; Bourdine, Anton V.

2017-04-01

This work presents method for performing precision macro-structure defects "tapers" and "up-tapers" written in conventional silica telecommunication multimode optical fibers by commercially available field fusion splicer with modified software settings and following writing fiber Bragg gratings over or near them. We developed technique for macrodefect geometry parameters estimation via analysis of photo-image performed after defect writing and displayed on fusion splicer screen. Some research results of defect geometry dependence on fusion current and fusion time values re-set in splicer program are represented that provided ability to choose their "the best" combination. Also experimental statistical researches concerned with "taper" and "up-taper" diameter stability as well as their insertion loss values during their writing under fixed corrected splicer program parameters were performed. We developed technique for FBG writing over or near macro-structure defect. Some results of spectral response measurements produced for short-length samples of multimode optical fiber with fiber Bragg gratings written over and near macro-defects prepared by using proposed technique are presented.

Screening for Barrett’s Esophagus

PubMed Central

di Pietro, Massimiliano; Chan, Daniel; Fitzgerald, Rebecca C.; Wang, Kenneth K.

2015-01-01

The large increase in the incidence of esophageal adeno-carcinoma in the West during the past 30 years has stimulated interest in screening for Barrett’s esophagus (BE), a precursor to esophageal cancer. Effective endoscopic treatments for dysplasia and intramucosal cancer, coupled with screening programs to detect BE, could help reverse the increase in the incidence of esophageal cancer. However, there are no accurate, cost-effective, minimally invasive techniques available to screen for BE, reducing the enthusiasm of gastroenterologists. Over the past 5 years, there has been significant progress in the development of screening technologies. We review existing and developing technologies, new minimally invasive imaging techniques, nonendoscopic devices for cell collection, and biomarkers that can be measured in blood or stool samples. We discuss the status of these approaches, data from clinical studies of their effects, and their anticipated strengths and weaknesses in screening. The area is rapidly evolving, and new tools will soon be ready for prime time. PMID:25701083

Psychophysical Calibration of Mobile Touch-Screens for Vision Testing in the Field

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.

2015-01-01

The now ubiquitous nature of touch-screen displays in cell phones and tablet computers makes them an attractive option for vision testing outside of the laboratory or clinic. Accurate measurement of parameters such as contrast sensitivity, however, requires precise control of absolute and relative screen luminances. The nonlinearity of the display response (gamma) can be measured or checked using a minimum motion technique similar to that developed by Anstis and Cavanagh (1983) for the determination of isoluminance. While the relative luminances of the color primaries vary between subjects (due to factors such as individual differences in pre-retinal pigment densities), the gamma nonlinearity can be checked in the lab using a photometer. Here we compare results obtained using the psychophysical method with physical measurements for a number of different devices. In addition, we present a novel physical method using the device's built-in front-facing camera in conjunction with a mirror to jointly calibrate the camera and display. A high degree of consistency between devices is found, but some departures from ideal performance are observed. In spite of this, the effects of calibration errors and display artifacts on estimates of contrast sensitivity are found to be small.

A Stochastic Spiking Neural Network for Virtual Screening.

PubMed

Morro, A; Canals, V; Oliver, A; Alomar, M L; Galan-Prado, F; Ballester, P J; Rossello, J L

2018-04-01

Virtual screening (VS) has become a key computational tool in early drug design and screening performance is of high relevance due to the large volume of data that must be processed to identify molecules with the sought activity-related pattern. At the same time, the hardware implementations of spiking neural networks (SNNs) arise as an emerging computing technique that can be applied to parallelize processes that normally present a high cost in terms of computing time and power. Consequently, SNN represents an attractive alternative to perform time-consuming processing tasks, such as VS. In this brief, we present a smart stochastic spiking neural architecture that implements the ultrafast shape recognition (USR) algorithm achieving two order of magnitude of speed improvement with respect to USR software implementations. The neural system is implemented in hardware using field-programmable gate arrays allowing a highly parallelized USR implementation. The results show that, due to the high parallelization of the system, millions of compounds can be checked in reasonable times. From these results, we can state that the proposed architecture arises as a feasible methodology to efficiently enhance time-consuming data-mining processes such as 3-D molecular similarity search.

Recombinant Kinase Production and Fragment Screening by NMR Spectroscopy.

PubMed

Han, Byeonggu; Ahn, Hee-Chul

2016-01-01

During the past decade fragment-based drug discovery (FBDD) has rapidly evolved and several drugs or drug candidates developed by FBDD approach are clinically in use or in clinical trials. For example, vemurafenib, a V600E mutated BRAF inhibitor, was developed by utilizing FBDD approach and approved by FDA in 2011. In FBDD, screening of fragments is the starting step for identification of hits and lead generation. Fragment screening usually relies on biophysical techniques by which the protein-bound small molecules can be detected. NMR spectroscopy has been extensively used to study the molecular interaction between the protein and the ligand, and has many advantages in fragment screening over other biophysical techniques. This chapter describes the practical aspects of fragment screening by saturation transfer difference NMR.

Developing science gateways for drug discovery in a grid environment.

PubMed

Pérez-Sánchez, Horacio; Rezaei, Vahid; Mezhuyev, Vitaliy; Man, Duhu; Peña-García, Jorge; den-Haan, Helena; Gesing, Sandra

2016-01-01

Methods for in silico screening of large databases of molecules increasingly complement and replace experimental techniques to discover novel compounds to combat diseases. As these techniques become more complex and computationally costly we are faced with an increasing problem to provide the research community of life sciences with a convenient tool for high-throughput virtual screening on distributed computing resources. To this end, we recently integrated the biophysics-based drug-screening program FlexScreen into a service, applicable for large-scale parallel screening and reusable in the context of scientific workflows. Our implementation is based on Pipeline Pilot and Simple Object Access Protocol and provides an easy-to-use graphical user interface to construct complex workflows, which can be executed on distributed computing resources, thus accelerating the throughput by several orders of magnitude.

Coupling Front-End Separations, Ion Mobility Spectrometry, and Mass Spectrometry For Enhanced Multidimensional Biological and Environmental Analyses

PubMed Central

Zheng, Xueyun; Wojcik, Roza; Zhang, Xing; Ibrahim, Yehia M.; Burnum-Johnson, Kristin E.; Orton, Daniel J.; Monroe, Matthew E.; Moore, Ronald J.; Smith, Richard D.; Baker, Erin S.

2017-01-01

Ion mobility spectrometry (IMS) is a widely used analytical technique for rapid molecular separations in the gas phase. Though IMS alone is useful, its coupling with mass spectrometry (MS) and front-end separations is extremely beneficial for increasing measurement sensitivity, peak capacity of complex mixtures, and the scope of molecular information available from biological and environmental sample analyses. In fact, multiple disease screening and environmental evaluations have illustrated that the IMS-based multidimensional separations extract information that cannot be acquired with each technique individually. This review highlights three-dimensional separations using IMS-MS in conjunction with a range of front-end techniques, such as gas chromatography, supercritical fluid chromatography, liquid chromatography, solid-phase extractions, capillary electrophoresis, field asymmetric ion mobility spectrometry, and microfluidic devices. The origination, current state, various applications, and future capabilities of these multidimensional approaches are described in detail to provide insight into their uses and benefits. PMID:28301728

Local, global, and nonlinear screening in twisted double-layer graphene

DOE PAGES

Lu, Chih -Pin; Rodriguez-Vega, Martin; Li, Guohong; ...

2016-06-02

One-atom-thick crystalline layers and their vertical heterostructures carry the promise of designer electronic materials that are unattainable by standard growth techniques. To realize their potential it is necessary to isolate them from environmental disturbances, in particular those introduced by the substrate. However, finding and characterizing suitable substrates, and minimizing the random potential fluctuations they introduce, has been a persistent challenge in this emerging field. In this paper, we show that Landau-level (LL) spectroscopy offers the unique capability to quantify both the reduction of the quasiparticles’ lifetime and the long-range inhomogeneity due to random potential fluctuations. Harnessing this technique together withmore » direct scanning tunneling microscopy and numerical simulations we demonstrate that the insertion of a graphene buffer layer with a large twist angle is a very effective method to shield a 2D system from substrate interference that has the additional desirable property of preserving the electronic structure of the system under study. Finally, we further show that owing to its remarkable nonlinear screening capability a single graphene buffer layer provides better shielding than either increasing the distance to the substrate or doubling the carrier density and reduces the amplitude of the potential fluctuations in graphene to values even lower than the ones in AB-stacked bilayer graphene.« less

Local, global, and nonlinear screening in twisted double-layer graphene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Chih -Pin; Rodriguez-Vega, Martin; Li, Guohong

One-atom-thick crystalline layers and their vertical heterostructures carry the promise of designer electronic materials that are unattainable by standard growth techniques. To realize their potential it is necessary to isolate them from environmental disturbances, in particular those introduced by the substrate. However, finding and characterizing suitable substrates, and minimizing the random potential fluctuations they introduce, has been a persistent challenge in this emerging field. In this paper, we show that Landau-level (LL) spectroscopy offers the unique capability to quantify both the reduction of the quasiparticles’ lifetime and the long-range inhomogeneity due to random potential fluctuations. Harnessing this technique together withmore » direct scanning tunneling microscopy and numerical simulations we demonstrate that the insertion of a graphene buffer layer with a large twist angle is a very effective method to shield a 2D system from substrate interference that has the additional desirable property of preserving the electronic structure of the system under study. Finally, we further show that owing to its remarkable nonlinear screening capability a single graphene buffer layer provides better shielding than either increasing the distance to the substrate or doubling the carrier density and reduces the amplitude of the potential fluctuations in graphene to values even lower than the ones in AB-stacked bilayer graphene.« less

Spatial and Temporal Variations of a Screening Current Induced Magnetic Field in a Double-Pancake HTS Insert of an LTS/HTS NMR Magnet

PubMed Central

Ahn, Min Cheol; Yagai, Tsuyoshi; Hahn, Seungyong; Ando, Ryuya; Bascuñán, Juan; Iwasa, Yukikazu

2010-01-01

This paper presents experimental and simulation results of a screening current induced magnetic field (SCF) in a high temperature superconductor (HTS) insert that constitutes a low-/high-temperature superconductor (LTS/HTS) NMR magnet. In this experiment, the HTS insert, a stack of 50 double-pancake coils, each wound with Bi2223 tape, was operated at 77 K. A screening current was induced in the HTS insert by three magnetic field sources: 1) a self field from the HTS insert; 2) an external field from a 5-T background magnet; and 3) combinations of 1) and 2). For each field excitation, which induced an SCF, its axial field distribution and temporal variations were measured and compared with simulation results based on the critical state model. Agreement on field profile between experiment and simulation is satisfactory but more work is needed to make the simulation useful for designing shim coils that will cancel the SCF. PMID:20401187

Deflectometry using a Hartmann screen to measure tilt, decentering and focus errors in a spherical surface

NASA Astrophysics Data System (ADS)

Muñoz-Potosi, A. F.; Granados-Agustín, F.; Campos-García, M.; Valdivieso-González, L. G.; Percino-Zacarias, M. E.

2017-11-01

Among the various techniques that can be used to assess the quality of optical surfaces, deflectometry evaluates the reflection experienced by rays impinging on a surface whose topography is under study. We propose the use of a screen spatial filter to select rays from a light source. The screen must be placed at a distance shorter than the radius of curvature of the surface under study. The location of the screen depends on the exit pupil of the system and the caustic area. The reflected rays are measured using an observation plane/screen/CCD located beyond the point of convergence of the rays. To implement an experimental design of the proposed technique and determine the topography of the surface under study, it is necessary to measure tilt, decentering and focus errors caused by mechanical misalignment, which could influence the results of this technique but are not related to the quality of the surface. The aim of this study is to analyze an ideal spherical surface with known radius of curvature to identify the variations introduced by such misalignment errors.

Screening fifth forces in k-essence and DBI models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brax, Philippe; Burrage, Clare; Davis, Anne-Christine, E-mail: Philippe.Brax@cea.fr, E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: A.C.Davis@damtp.cam.ac.uk

New fifth forces have not yet been detected in the laboratory or in the solar system, hence it is typically difficult to introduce new light scalar fields that would mediate such forces. In recent years it has been shown that a number of non-linear scalar field theories allow for a dynamical mechanism, such as the Vainshtein and chameleon ones, that suppresses the strength of the scalar fifth force in experimental environments. This is known as screening, however it is unclear how common screening is within non-linear scalar field theories. k-essence models are commonly studied examples of non-linear models, with DBImore » as the best motivated example, and so we ask whether these non-linearities are able to screen a scalar fifth force. We find that a Vainshtein-like screening mechanism exists for such models although with limited applicability. For instance, we cannot find a screening mechanism for DBI models. On the other hand, we construct a large class of k-essence models which lead to the acceleration of the Universe in the recent past for which the fifth force mediated by the scalar can be screened.« less

Application of pulsed field gradient NMR techniques for investigating binding of flavor compounds to macromolecules.

PubMed

Jung, Da-Mi; De Ropp, Jeffrey S; Ebeler, Susan E

2002-07-17

Two diffusion-based NMR techniques are presented and used to investigate the binding of selected flavor compounds to macromolecules. A pulsed field gradient NMR (PFG-NMR) method was applied to measure the apparent diffusion coefficients of four alkanone compounds as they associated with bovine serum albumin (BSA). The change in the apparent diffusion coefficient as a function of the BSA/alkanone ratio was fitted to yield binding constants (K(a)()) and binding stoichiometry (n) for each alkanone. The results showed that the apparent diffusion coefficients of alkanones increased with a decrease in the BSA/alkanone ratios, and the measured values of K(a)() and n were comparable with those obtained with other methods and depended on the alkanone structure. A diffusion-based nuclear Overhauser effect (called diffusion NOE pumping) method was also applied to screen mixtures of flavor compounds and identify those that have a binding affinity to complex macromolecules. Using this technique benzaldehyde and vanillin were observed to bind with bovine serum albumin, whereas 2-phenylethanol was identified as a nonbinding or weakly binding ligand with BSA. The diffusion NOE pumping method was also applied to a hydro alcoholic solution of cacao bean tannin extracts to which a mixture of ethylbenzoate, benzaldehyde, and 2-phenylethanol was added. The diffusion NOE pumping technique clearly indicated that ethylbenzoate had a stronger binding affinity to the polymeric (-)-epicatechin units of the cacao bean tannin extracts than the other two flavor compounds. The results successfully demonstrate the potential applications of diffusion-based NMR techniques for studying flavors and nonvolatile food matrix interactions.

Evaluation of viewing experiences induced by curved 3D display

NASA Astrophysics Data System (ADS)

Mun, Sungchul; Park, Min-Chul; Yano, Sumio

2015-05-01

As advanced display technology has been developed, much attention has been given to flexible panels. On top of that, with the momentum of the 3D era, stereoscopic 3D technique has been combined with the curved displays. However, despite the increased needs for 3D function in the curved displays, comparisons between curved and flat panel displays with 3D views have rarely been tested. Most of the previous studies have investigated their basic ergonomic aspects such as viewing posture and distance with only 2D views. It has generally been known that curved displays are more effective in enhancing involvement in specific content stories because field of views and distance from the eyes of viewers to both edges of the screen are more natural in curved displays than in flat panel ones. For flat panel displays, ocular torsions may occur when viewers try to move their eyes from the center to the edges of the screen to continuously capture rapidly moving 3D objects. This is due in part to differences in viewing distances from the center of the screen to eyes of viewers and from the edges of the screen to the eyes. Thus, this study compared S3D viewing experiences induced by a curved display with those of a flat panel display by evaluating significant subjective and objective measures.

A methodology to evaluate differential costs of full field digital as compared to conventional screen film mammography in a clinical setting.

PubMed

Ciatto, S; Brancato, B; Baglioni, R; Turci, M

2006-01-01

The use of full field digital mammography (FFDM) in alternative to conventional screen film mammography (SFM) in the current practice is delayed by the high costs of FFDM. The present study, performed at the Centro per lo Studio e la Prevenzione Oncologica of Florence, using both FFDM and SFM, was aimed at estimating the impact of introducing the new FFDM technique on overall mammography costs. We estimated the differential costs of both methods, based on real expenditures, as provided by the administrative department, and on radiologists, radiographers and other staff's working time. Two different workload scenarios (5000 and 10,000 tests/year per mammography equipment) were considered. Common costs of both techniques were censored for study purpose. Beside a higher cost due to purchase and hire/leasing costs of equipment, FFDM implies a greater workload for radiologists (reading time almost doubled). SFM implies a greater workload for the administrative staff to run the archive and for loading/unloading films of the roller viewer, whereas no different workload has been observed for radiographers. Overall FFDM costs 24.22-26.46 for examination more than SFM for the 5000 tests scenario and 9.91-12.15 more for the 10,000 tests scenario. Although present study estimates cannot easily be generalised to any local setting, the model for cost calculation is easy to be exported to another scenario by applying different local parameters. The advantages made available by FFDM (computerised data recording, tele-transmission, tele-reporting, tele-consulting, automatic display on monitor of previous exams and use of CAD) may justify the higher cost, but a limited reduction in purchase and assistance costs could easily allow a turnover, with FFDM being more convenient than SFM even on the cost side.

New fluorescence techniques for high-throughput drug discovery.

PubMed

Jäger, S; Brand, L; Eggeling, C

2003-12-01

The rapid increase of compound libraries as well as new targets emerging from the Human Genome Project require constant progress in pharmaceutical research. An important tool is High-Throughput Screening (HTS), which has evolved as an indispensable instrument in the pre-clinical target-to-IND (Investigational New Drug) discovery process. HTS requires machinery, which is able to test more than 100,000 potential drug candidates per day with respect to a specific biological activity. This calls for certain experimental demands especially with respect to sensitivity, speed, and statistical accuracy, which are fulfilled by using fluorescence technology instrumentation. In particular the recently developed family of fluorescence techniques, FIDA (Fluorescence Intensity Distribution Analysis), which is based on confocal single-molecule detection, has opened up a new field of HTS applications. This report describes the application of these new techniques as well as of common fluorescence techniques--such as confocal fluorescence lifetime and anisotropy--to HTS. It gives experimental examples and presents advantages and disadvantages of each method. In addition the most common artifacts (auto-fluorescence or quenching by the drug candidates) emerging from the fluorescence detection techniques are highlighted and correction methods for confocal fluorescence read-outs are presented, which are able to circumvent this deficiency.

High-throughput screening of hybridoma supernatants using multiplexed fluorescent cell barcoding on live cells.

PubMed

Lu, Mei; Chan, Brian M; Schow, Peter W; Chang, Wesley S; King, Chadwick T

2017-12-01

With current available assay formats using either immobilized protein (ELISA, enzyme-linked immunosorbent assay) or immunostaining of fixed cells for primary monoclonal antibody (mAb) screening, researchers often fail to identify and characterize antibodies that recognize the native conformation of cell-surface antigens. Therefore, screening using live cells has become an integral and important step contributing to the successful identification of therapeutic antibody candidates. Thus the need for developing high-throughput screening (HTS) technologies using live cells has become a major priority for therapeutic mAb discovery and development. We have developed a novel technique called Multiplexed Fluorescent Cell Barcoding (MFCB), a flow cytometry-based method based upon the Fluorescent Cell Barcoding (FCB) technique and the Luminex fluorescent bead array system, but is applicable to high-through mAb screens on live cells. Using this technique in our system, we can simultaneously identify or characterize the antibody-antigen binding of up to nine unique fluorescent labeled cell populations in the time that it would normally take to process a single population. This has significantly reduced the amount of time needed for the identification of potential lead candidates. This new technology enables investigators to conduct large-scale primary hybridoma screens using flow cytometry. This in turn has allowed us to screen antibodies more efficiently than before and streamline identification and characterization of lead molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Hui

2001-01-01

Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, we introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties of suitablymore » designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, we demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm 2 for 40-μm wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection.« less

Cell-phone based assistance for waterworks/sewage plant maintenance.

PubMed

Kawada, T; Nakamichi, K; Hisano, N; Kitamura, M; Miyahara, K

2006-01-01

Cell-phones are now incorporating the functions necessary for them to be used as mobile IT devices. In this paper, we present our results of the evaluation of cell-phones as the mobile IT device to assist workers in industrial plants. We use waterworks and sewage plants as examples. By employing techniques to squeeze the SCADA screen on CRT into a small cell-phone LCD, we have made it easier for a plant's field workers to access the information needed for effective maintenance, regardless of location. An idea to link SCADA information and the plant facility information on the cell-phone is also presented. Should an accident or emergency situation arise, these cell-phone-based IT systems can efficiently deliver the latest plant information, thus the worker out in the field can respond to and resolve the emergency.

Effect of anisotropic thermal transport on the resistive plasma response to resonant magnetic perturbation field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bai, Xue; Liu, Yueqiang; Gao, Zhe

Plasma response to the resonant magnetic perturbation (RMP) field is numerically investigated by an extended toroidal fluid model, which includes anisotropic thermal transport physics parallel and perpendicular to the total magnetic field. The thermal transport is found to be effective in eliminating the toroidal average curvature induced plasma screening (the so called Glasser-Green-Johnson, GGJ screening) at slow toroidal flow regime, whilst having minor effect on modifying the conventional plasma screening regimes at faster flow. Furthermore, this physics effect of interaction between thermal transport and GGJ screening is attributed to the modification of the radial structure of the shielding current, resultedmore » from the plasma response to the applied field. The modification of the plasma response (shielding current, response field, plasma displacement and the perturbed velocity) also has direct consequence on the toroidal torques produced by RMP. These modelling results show that thermal transport reduces the resonant electromagnetic torque as well as the torque associated with the Reynolds stress, but enhances the neoclassical toroidal viscous torque at slow plasma flow.« less

Effect of anisotropic thermal transport on the resistive plasma response to resonant magnetic perturbation field

DOE PAGES

Bai, Xue; Liu, Yueqiang; Gao, Zhe

2017-09-21

Plasma response to the resonant magnetic perturbation (RMP) field is numerically investigated by an extended toroidal fluid model, which includes anisotropic thermal transport physics parallel and perpendicular to the total magnetic field. The thermal transport is found to be effective in eliminating the toroidal average curvature induced plasma screening (the so called Glasser-Green-Johnson, GGJ screening) at slow toroidal flow regime, whilst having minor effect on modifying the conventional plasma screening regimes at faster flow. Furthermore, this physics effect of interaction between thermal transport and GGJ screening is attributed to the modification of the radial structure of the shielding current, resultedmore » from the plasma response to the applied field. The modification of the plasma response (shielding current, response field, plasma displacement and the perturbed velocity) also has direct consequence on the toroidal torques produced by RMP. These modelling results show that thermal transport reduces the resonant electromagnetic torque as well as the torque associated with the Reynolds stress, but enhances the neoclassical toroidal viscous torque at slow plasma flow.« less

Effect of anisotropic thermal transport on the resistive plasma response to resonant magnetic perturbation field

NASA Astrophysics Data System (ADS)

Bai, Xue; Liu, Yueqiang; Gao, Zhe

2017-10-01

Plasma response to the resonant magnetic perturbation (RMP) field is numerically investigated by an extended toroidal fluid model, which includes anisotropic thermal transport physics parallel and perpendicular to the total magnetic field. The thermal transport is found to be effective in eliminating the toroidal average curvature induced plasma screening (the so called Glasser-Green-Johnson, GGJ screening) in a slow toroidal flow regime, whilst having minor effect on modifying the conventional plasma screening regimes at faster flow. This physics effect of interaction between thermal transport and GGJ screening is attributed to the modification of the radial structure of the shielding current, which resulted from the plasma response to the applied field. The modification of the plasma response (shielding current, response field, plasma displacement, and the perturbed velocity) also has direct consequence on the toroidal torques produced by RMP. Modelling results show that thermal transport reduces the resonant electromagnetic torque as well as the torque associated with the Reynolds stress, but enhances the neoclassical toroidal viscous torque at slow plasma flow.

Psychological first aid training for Lebanese field workers in the emergency context of the Syrian refugees in Lebanon.

PubMed

Akoury-Dirani, Leyla; Sahakian, Tina S; Hassan, Fahed Y; Hajjar, Ranya V; El Asmar, Khalil

2015-11-01

The Syrian refugee crisis in Lebanon required a fast and efficient comprehensive rescue strategy. Professionals working in emergency response were neither prepared to provide psychological first aid nor prepared to screen for mental health disorders in child refugees. This article examines the efficacy of a national training program in psychological first aid (PFA) to enhance the readiness of mental health field workers in the Syrian refugee response. Participant (N = 109) were recruited from Lebanese ministries and nongovernmental organizations. They received a 2.5-day training on PFA and on screening for mental health disorders in children. Their knowledge and perceived readiness were assessed before the training, immediately after the training, and 1 month after the training using 2 evaluation forms. Evaluation Form A was a multiple choice questionnaire composed of 20 questions and created on the basis of the content of the training, and Evaluation Form B was a Likert-type scale of 20 items created based on the core components of PFA. The data of 60 participants were analyzed. The results showed a significant increase in knowledge and readiness, specifically on the components related to the principles and techniques of PFA. (c) 2015 APA, all rights reserved).

TECHNOLOGIES FOR MONITORING AND MEASUREMENT ...

EPA Pesticide Factsheets

A demonstration of technologies for determining the presence of dioxin and dioxin-like compounds in soil and sediment was conducted under EPA's Superfund Innovative Technology Evaluation Program in Saginaw, Michigan in April 2004. This report describes the performance evaluation of CAPE Technologies DF-1 Dioxin/Furan and PCB TEQ Immunoassay Kits. The kits are immunoassay techniques that report the total toxicity equivalents (TEQ) of dioxin/furans and polychlorinated biphenyls (PCBs. The technology results were compared to high resolution mass spectrometry TEQ results generated using EPA Methods 1613B and 1668A.The CAPE Technologies kits generally reported data higher than the certified PE and reference laboratory values. The technologys estimated MDL was 12 to 33 pg/g TEQ. Results from this demonstration suggest that the CAPE Technologies kits could be an effective screening tool for determining sample results above and below 20 pg/g TEQ and even more effective as a screen for sample above and below 50 pg/g TEQ, particularly considering that both the cost ($59,234 vs. $398,029) and the time (3 weeks vs. 8 months) to analyze the 209 demonstration samples were significantly less than those of the reference laboratory. The objective of this program is to promote the acceptance and use of innovative field technologies by providing well-documented performance and cost data obtained from field demonstrations.

Acquisition parameters optimization of a transmission electron forward scatter diffraction system in a cold-field emission scanning electron microscope for nanomaterials characterization.

PubMed

Brodusch, Nicolas; Demers, Hendrix; Trudeau, Michel; Gauvin, Raynald

2013-01-01

Transmission electron forward scatter diffraction (t-EFSD) is a new technique providing crystallographic information with high resolution on thin specimens by using a conventional electron backscatter diffraction (EBSD) system in a scanning electron microscope. In this study, the impact of tilt angle, working distance, and detector distance on the Kikuchi pattern quality were investigated in a cold-field emission scanning electron microscope (CFE-SEM). We demonstrated that t-EFSD is applicable for tilt angles ranging from -20° to -40°. Working distance (WD) should be optimized for each material by choosing the WD for which the EBSD camera screen illumination is the highest, as the number of detected electrons on the screen is directly dependent on the scattering angle. To take advantage of the best performances of the CFE-SEM, the EBSD camera should be close to the sample and oriented towards the bottom to increase forward scattered electron collection efficiency. However, specimen chamber cluttering and beam/mechanical drift are important limitations in the CFE-SEM used in this work. Finally, the importance of t-EFSD in materials science characterization was illustrated through three examples of phase identification and orientation mapping. © Wiley Periodicals, Inc.

TECHNOLOGIES FOR MONITORING AND MEASUREMENT ...

EPA Pesticide Factsheets

A demonstration of technologies for determining the presence of dioxin and dioxin-like compounds in soil and sediment was conducted under EPA's Superfund Innovative Technology Evaluation Program in Saginaw, Michigan in April 2004. This report describes the performance evaluation of the Abraxis LLC Coplanar PCB Enzyme-Linked Immunosorbent Assay (ELISA) kit. The kit is an immunoassay technique that reports the total toxicity equivalents (TEQ) of polychlorinated biphenyls (PCBs). The technology results were compared to high resolution mass spectrometry TEQ results generated using EPA Method 1668A.Abraxis generally reported data that were higher than the reference laboratory TEQPCB values, with the exception of ultra-high level PCB samples [> 10,000 picogram/gram (pg/g) TEQ] where Abraxis reported values lower than the reference method. The technologys estimated MDL was 6 to 31 pg/g TEQPCB. Results from this demonstration suggest that the Abraxis kit could be an effective screening tool for screening sample concentrations above and below 50 pg/g TEQPCB, particularly considering that the cost ($22,668 vs. $184,449) and the time to analyze the 209 demonstration samples were significantly less than those of the reference laboratory. The objective of this program is to promote the acceptance and use of innovative field technologies by providing well-documented performance and cost data obtained from field demonstrations.

Field test of on-site drug detection devices

DOT National Transportation Integrated Search

2000-10-01

This NHTSA-sponsored study reports the findings of a field evaluation of five on-site drug screening devices used by law enforcement to screen for illicit drugs among drivers suspected of driving under the influence (DUI) of alcohol or other drugs. I...

DEMONSTRATION BULLETIN: FIELD ANALYTICAL SCREENING PROGRAM: PCB METHOD - U.S. ENVIRONMENTAL PROTECTION AGENCY

EPA Science Inventory

The field analytical screening program (FASP) polychlorinated biphenyl (PCB) method uses a temperature-programmable gas chromatograph (GC) equipped with an electron capture detector (ECD) to identify and quantify PCBs. Gas chromatography is an EPA-approved method for determi...

FIELD ANALYTICAL SCREENING PROGRAM: PCP METHOD - INNOVATIVE TECHNOLOGY EVALUATION REPORT

EPA Science Inventory

The Field Analytical Screening Program (FASP) pentachlorophenol (PCP) method uses a gas chromatograph (GC) equipped with a megabore capillary column and flame ionization detector (FID) and electron capture detector (ECD) to identify and quantify PCP. The FASP PCP method is design...

Phoenito experiments: combining the strengths of commercial crystallization automation.

PubMed

Newman, Janet; Pham, Tam M; Peat, Thomas S

2008-11-01

The use of crystallization robots for initial screening in macromolecular crystallization is well established. This paper describes how four general optimization techniques, growth-rate modulation, fine screening, seeding and additive screening, have been adapted for automation in a medium-throughput crystallization service facility. The use of automation for more challenging optimization experiments is discussed, as is a novel way of using both the Mosquito and the Phoenix nano-dispensing robots during the setup of a single crystallization plate. This dual-dispenser technique plays to the strengths of both machines.

Phoenito experiments: combining the strengths of commercial crystallization automation

PubMed Central

Newman, Janet; Pham, Tam M.; Peat, Thomas S.

2008-01-01

The use of crystallization robots for initial screening in macromolecular crystallization is well established. This paper describes how four general optimization techniques, growth-rate modulation, fine screening, seeding and additive screening, have been adapted for automation in a medium-throughput crystallization service facility. The use of automation for more challenging optimization experiments is discussed, as is a novel way of using both the Mosquito and the Phoenix nano-dispensing robots during the setup of a single crystallization plate. This dual-dispenser technique plays to the strengths of both machines. PMID:18997323

Taking transgenic rice drought screening to the field.

PubMed

Gaudin, Amélie C M; Henry, Amelia; Sparks, Adam H; Slamet-Loedin, Inez H

2013-01-01

Numerous transgenes have been reported to increase rice drought resistance, mostly in small-scale experiments under vegetative-stage drought stress, but few studies have included grain yield or field evaluations. Different definitions of drought resistance are currently in use for field-based and laboratory evaluations of transgenics, the former emphasizing plant responses that may not be linked to yield under drought. Although those fundamental studies use efficient protocols to uncover and validate gene functions, screening conditions differ greatly from field drought environments where the onset of drought stress symptoms is slow (2-3 weeks). Simplified screening methods, including severely stressed survival studies, are therefore not likely to identify transgenic events with better yield performance under drought in the target environment. As biosafety regulations are becoming established to allow field trials in some rice-producing countries, there is a need to develop relevant screening procedures that scale from preliminary event selection to greenhouse and field trials. Multilocation testing in a range of drought environments may reveal that different transgenes are necessary for different types of drought-prone field conditions. We describe here a pipeline to improve the selection efficiency and reproducibility of results across drought treatments and test the potential of transgenic rice for the development of drought-resistant material for agricultural purposes.

[Screening for atherosclerosis to prevent cardiovascular risk : a pro-contra debate].

PubMed

Nanchen, David; Genest, Jacques

2018-02-28

Detecting atherosclerosis using imaging techniques is the subject of intense debate in the scientific community. Among the arguments in favor of screening, a better identification or better stratification of cardiovascular risk is mentioned, compared to cardiovascular risk scores based solely on traditional risk factors, such as blood pressure or cholesterol levels. Imaging techniques are also used to monitor the progression of atherosclerosis among patients using lipid-lowering or antihypertensive drugs in primary prevention. However, several experts in recent years have challenged the clinical utility of these imaging techniques in asymptomatic adults. This article proposes a debate « for or against » to describe the main arguments for or against the use of imaging for screening for atherosclerosis.

Monocular display unit for 3D display with correct depth perception

NASA Astrophysics Data System (ADS)

Sakamoto, Kunio; Hosomi, Takashi

2009-11-01

A study of virtual-reality system has been popular and its technology has been applied to medical engineering, educational engineering, a CAD/CAM system and so on. The 3D imaging display system has two types in the presentation method; one is a 3-D display system using a special glasses and the other is the monitor system requiring no special glasses. A liquid crystal display (LCD) recently comes into common use. It is possible for this display unit to provide the same size of displaying area as the image screen on the panel. A display system requiring no special glasses is useful for a 3D TV monitor, but this system has demerit such that the size of a monitor restricts the visual field for displaying images. Thus the conventional display can show only one screen, but it is impossible to enlarge the size of a screen, for example twice. To enlarge the display area, the authors have developed an enlarging method of display area using a mirror. Our extension method enables the observers to show the virtual image plane and to enlarge a screen area twice. In the developed display unit, we made use of an image separating technique using polarized glasses, a parallax barrier or a lenticular lens screen for 3D imaging. The mirror can generate the virtual image plane and it enlarges a screen area twice. Meanwhile the 3D display system using special glasses can also display virtual images over a wide area. In this paper, we present a monocular 3D vision system with accommodation mechanism, which is useful function for perceiving depth.

Field-based evaluations of horizontal flat-plate fish screens

USGS Publications Warehouse

Rose, B.P.; Mesa, M.G.; Barbin-Zydlewski, G.

2008-01-01

Diversions from streams are often screened to prevent the loss of or injury to fish. Hydraulic criteria meant to protect fish that encounter screens have been developed, but primarily for screens that are vertical to the water flow rather than horizontal. For this reason, we measured selected hydraulic variables and released wild rainbow trout Oncorhynchus mykiss over two types of horizontal flat-plate fish screens in the field. Our goal was to assess the efficacy of these screens under a variety of conditions in the field and provide information that could be used to develop criteria for safe fish passage. We evaluated three different invertedweir screens over a range of stream (0.24-1.77 m3/s) and diversion flows (0.10-0.31 m3/s). Approach velocities (AVs) ranged from 3 to 8 cm/s and sweeping velocities (SVs) from 69 to 143 cm/s. We also evaluated a simple backwatered screen over stream flows of 0.23-0.79 m3/s and diversion flows of 0.08-0.32 m3/s. The mean SVs for this screen ranged from 15 to 66 cm/s and the mean AVs from 1 to 5 cm/s. The survival rates of fish held for 24 h after passage over these screens exceeded 98%. Overall, the number of fish-screen contacts was low and the injuries related to passage were infrequent and consisted primarily of minor fin injuries. Our results indicate that screens of this type have great potential as safe and effective fish screens for small diversions. Care must be taken, however, to avoid operating conditions that produce shallow or no water over the screen surface, situations of high AVs and low SVs at backwatered screens, and situations producing a localized high AV with spiraling flow. ?? Copyright by the American Fisheries Society 2008.

Molecular biology of Ganoderma pathogenicity and diagnosis in coconut seedlings.

PubMed

Kandan, A; Radjacommare, R; Ramanathan, A; Raguchander, T; Balasubramanian, P; Samiyappan, R

2009-01-01

The pathogenicity of Ganoderma boninense was tested on coconut seedlings under greenhouse conditions and infection confirmed by using immunological and molecular diagnostic tools. Desiccation of older leaves and the emergence of sporophores were observed from pathogen-inoculated seedlings, whereas a control seedling does not show any pathogenic symptoms. Mature sporophores were formed within 10-13 weeks after inoculation. Polyclonal antibodies raised against mycelial proteins of Ganoderma were used for detection of Ganoderma in infected field palm and seedlings through indirect enzyme-linked immunosorbent assay technique. We adopted dot-immunobinding assay for the detection of Ganoderma from greenhouse and field samples. Under nucleic-acid-based diagnosis, G. boninense (167 bp) was detected from artificially inoculated seedlings and infected field palms by polymerase chain reaction. Apart from these, histopathological studies also support the Ganoderma pathogenicity in coconut seedlings. The pathogenicity test and combination of all the three diagnostic methods for Ganoderma could be highly reliable, rapid, sensitive and effective screening of resistance in planting material in the future.

A Comparative Study on Willingness to Pay for Breast Cancer and Osteoporosis Screening in Kerman, Southeastern Iran.

PubMed

Sabermahani, Asma; Mohammad Taghizade, Sedighe; Goodarzi, Reza

2017-05-01

One of the economic evaluation techniques involves calculation of willingness to pay (WTP) for a service to find out the value of that service from the clients' perspective. This study estimated WTP for both breast cancer and osteoporosis screening and comparatively examined the contributing factors. In fact, the comparisons served to provide an exact analysis of individual attitudes and behaviors in relation to screening programs for cancers and other diseases. This study was first designed in six scenarios several questionnaires concerning individual breast cancer and osteoporosis screening cases, and determined the WTP median in each scenario between people in Kerman Province of Iran in 2016. Then, the demand function for breast cancer and osteoporosis screening was formulated. Moreover, the factors contributing to WTP were examined through various scenarios in Stata and econometric techniques. The median and mean values of WTP in all the above scenarios were greater for breast cancer screening than for osteoporosis screening. Theoretically, the price assumed a minus sign whereas risk assumed a plus sign within the demand function formulated for both screening programs. Regarding the evaluated factors, age in breast cancer screening and risk of disease in osteoporosis screening were the major factors contributing to WTP. Breast cancer screening was more valuable than osteoporosis screening program from the perspective of the subjects. The programs can be successfully designed by concentrating on patients' age groups in breast cancer screening and high-risk patients in osteoporosis screening.

iPads in Breast Imaging – A Phantom Study

PubMed Central

Hammon, M.; Schlechtweg, P. M.; Schulz-Wendtland, R.; Uder, M.; Schwab, S. A.

2014-01-01

Introduction: Modern tablet PCs as the iPad are becoming more and more integrated into medicine. The aim of this study was to evaluate the display quality of iPads regarding digital mammography. Materials and Methods: Three experienced readers compared the display quality of the iPad 2 and 3 with a dedicated 10 megapixel (MP) mammography liquid crystal display (LCD) screen in consensus using the standardized Contrast Detail Mammography (CDMAM) phantom. Phantom fields without agreement between the readers were classified as “uncertain”, correct 2 : 1 decisions were classified as “uncertain/readable”. In a second step display quality of the three reading devices was judged subjectively in a side by side comparison. Results: The 10 MP screen was superior to both iPads in 4 (phantom-)fields and inferior in 2 fields. Comparing the iPads, version 3 was superior in 4 fields and version 2 was superior in 1 field. However these differences were not significant. Total number of “uncertain” fields did not show significant differences. The number of “uncertain” fields was 15 with the 10 MP screen, 16 with the iPad 2 and 17 with the iPad 3 (p > 0.05), the number of “uncertain/readable” fields was 4, 7 and 8, respectively. Subjective image quality of the iPad 3 and the 10 MP screen was rated superior to the iPad 2. Conclusion: The evaluated iPads, especially in version 3, seem to be adequate to display mammograms in a diagnostic quality and thus could be useful e.g. for patient consultation, clinical demonstration or educational and teaching purposes. However primary mammogram reading should still be performed on dedicated large sized reading screens. PMID:24741126

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burrage, Clare; Copeland, Edmund J.; Hinds, E.A., E-mail: Clare.Burrage@nottingham.ac.uk, E-mail: Edmund.Copeland@nottingham.ac.uk, E-mail: Ed.Hinds@imperial.ac.uk

Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

Digital Screening and Halftone Techniques for Raster Processing,

DTIC Science & Technology

1980-01-14

I 7 A)-AO81 090 ARMY ENGINEER TOPOGRAPH4IC LASS FORT Bs.voiR VA 161/ OIGITAL SCREENING ANO HALFTONE TECNNIOUIES FOR RASTER PROCLPSINM-.TC(U) JAN GO R... HALFTONE TECHNIQUES 0FOR RASTER PROCESSING BY RICHARD L. ROSENTHAL DTIC FEB 𔃼 7 1980 W.A Approved for public release; distribution unlimited AU...creening and halftone techniques forlt -rastei’ processing ~ A 6. PERFORMING ORG. REPORT NUMBER 7. AUTNOP-r- S. CONTRACT OR GRANT NUMBER(*) c*t- Ri chard

Advanced Millimeter-Wave Imaging Enhances Security Screening

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheen, David M.; Bernacki, Bruce E.; McMakin, Douglas L.

2012-01-12

Millimeter-wave imaging is rapidly gaining acceptance for passenger screening at airports and other secured facilities. This paper details a number of techniques developed over the last several years including novel image reconstruction and display techniques, polarimetric imaging techniques, array switching schemes, as well as high frequency high bandwidth techniques. Implementation of some of these methods will increase the cost and complexity of the mm-wave security portal imaging systems. RF photonic methods may provide new solutions to the design and development of the sequentially switched linear mm-wave arrays that are the key element in the mm-wave portal imaging systems.

FIELD SCREENING METHODS FOR HAZARDOUS WASTES AND TOXIC CHEMICALS

EPA Science Inventory

The purpose of this document is to present the technical papers that were presented at the Second International Symposium on Field Screening Methods for Hazardous Wastes and Toxic Chemicals. ixty platform presentations were made and included in one of ten sessions: hemical sensor...

Screening and detection of elder abuse: Research opportunities and lessons learned from emergency geriatric care, intimate partner violence, and child abuse.

PubMed

Beach, Scott R; Carpenter, Christopher R; Rosen, Tony; Sharps, Phyllis; Gelles, Richard

2016-01-01

This article provides an overview of elder abuse screening and detection methods for community-dwelling and institutionalized older adults, including general issues and challenges for the field. Then, discussions of applications in emergency geriatric care, intimate partner violence (IPV), and child abuse are presented to inform research opportunities in elder abuse screening. The article provides descriptions of emerging screening and detection methods and technologies from the emergency geriatric care and IPV fields. We also discuss the variety of potential barriers to effective screening and detection from the viewpoint of the older adult, caregivers, providers, and the health care system, and we highlight the potential harms and unintended negative consequences of increased screening and mandatory reporting. We argue that research should continue on the development of valid screening methods and tools, but that studies of perceived barriers and potential harms of elder abuse screening among key stakeholders should also be conducted.

The shape dependence of chameleon screening

NASA Astrophysics Data System (ADS)

Burrage, Clare; Copeland, Edmund J.; Moss, Adam; Stevenson, James A.

2018-01-01

Chameleon scalar fields can screen their associated fifth forces from detection by changing their mass with the local density. These models are an archetypal example of a screening mechanism, and have become an important target for both cosmological surveys and terrestrial experiments. In particular there has been much recent interest in searching for chameleon fifth forces in the laboratory. It is known that the chameleon force is less screened around non-spherical sources, but only the field profiles around a few simple shapes are known analytically. In this work we introduce a numerical code that solves for the chameleon field around arbitrary shapes with azimuthal symmetry placed in a spherical vacuum chamber. We find that deviations from spherical symmetry can increase the chameleon acceleration experienced by a test particle, and that the least screened objects are those which minimize some internal dimension. For the shapes considered in this work, keeping the mass, density and background environment fixed, the accelerations due to the source varied by a factor of ~ 3.

Comprehensive embryo testing. Experts' opinions regarding future directions: an expert panel study on comprehensive embryo testing.

PubMed

Hens, Kristien; Dondorp, Wybo J; Geraedts, Joep P M; de Wert, Guido M

2013-05-01

What do scientists in the field of preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) consider to be the future direction of comprehensive embryo testing? Although there are many biological and technical limitations, as well as uncertainties regarding the meaning of genetic variation, comprehensive embryo testing will impact the IVF/PGD practice and a timely ethical reflection is needed. Comprehensive testing using microarrays is currently being introduced in the context of PGD and PGS, and it is to be expected that whole-genome sequencing will also follow. Current ethical and empirical sociological research on embryo testing focuses on PGD as it is practiced now. However, empirical research and systematic reflection regarding the impact of comprehensive techniques for embryo testing is missing. In order to understand the potential of this technology and to be able to adequately foresee its implications, we held an expert panel with seven pioneers in PGD. We conducted an expert panel in October 2011 with seven PGD pioneers from Belgium, The Netherlands, Germany and the UK. Participants expected the use of comprehensive techniques in the context of PGD. However, the introduction of these techniques in embryo testing requires timely ethical reflection as it involves a shift from choosing an embryo without a particular genetic disease (i.e. PGD) or most likely to result in a successful pregnancy (i.e. PGS) to choosing the best embryo based on a much wider set of criteria. Such ethical reflection should take account of current technical and biological limitations and also of current uncertainties with regard to the meaning of genetic variance. However, ethicists should also not be afraid to look into the future. There was a general agreement that embryo testing will be increasingly preceded by comprehensive preconception screening, thus enabling smart combinations of genetic testing. The group was composed of seven participants from four Western Europe countries. As willingness to participate in this study may be connected with expectations regarding the pace and direction of future developments, selection bias cannot be excluded. The introduction of comprehensive screening techniques in embryo testing calls for further ethical reflection that is grounded in empirical work. Specifically, there is a need for studies querying the opinions of infertile couples undergoing IVF/PGS regarding the desirability of embryo screening beyond aneuploidy. This research was supported by the CSG, Centre for Society and Life Sciences (project number: 70.1.074). The authors declare no conflict of interest. N/A.

Wavelet-based multifractal analysis of dynamic infrared thermograms to assist in early breast cancer diagnosis

PubMed Central

Gerasimova, Evgeniya; Audit, Benjamin; Roux, Stephane G.; Khalil, André; Gileva, Olga; Argoul, Françoise; Naimark, Oleg; Arneodo, Alain

2014-01-01

Breast cancer is the most common type of cancer among women and despite recent advances in the medical field, there are still some inherent limitations in the currently used screening techniques. The radiological interpretation of screening X-ray mammograms often leads to over-diagnosis and, as a consequence, to unnecessary traumatic and painful biopsies. Here we propose a computer-aided multifractal analysis of dynamic infrared (IR) imaging as an efficient method for identifying women with risk of breast cancer. Using a wavelet-based multi-scale method to analyze the temporal fluctuations of breast skin temperature collected from a panel of patients with diagnosed breast cancer and some female volunteers with healthy breasts, we show that the multifractal complexity of temperature fluctuations observed in healthy breasts is lost in mammary glands with malignant tumor. Besides potential clinical impact, these results open new perspectives in the investigation of physiological changes that may precede anatomical alterations in breast cancer development. PMID:24860510

Characterization of polymer silver pastes for screen printed flexible RFID antennas

NASA Astrophysics Data System (ADS)

Janeczek, Kamil; Jakubowska, Małgorzata; Futera, Konrad; MłoŻniak, Anna; Kozioł, GraŻyna; Araźna, Aneta

Radio Frequency Identification (RFID) systems have become more and more popular in the last few years because of their wide application fields, such as supply chain management and logistics. To continue their development further investigations of new conductive materials for fabrication of RFID transponders' antennas are necessary to be carried out. These materials should provide high flexibility and good radiation performance of printed antennas. In this paper, two polymer silver pastes based on silver flakes were characterized with regard to manufacturing of flexible RFID antennas with screen printing technique. Foil and paper were used as a substrate materials. Surface profile of the printed antennas was measured using an optical profilometer and their resistance was measured with a four-point-probe method. Antenna flexibility was evaluated in cyclic bending tests and its performance with reflection coefficient measurements with the use of differential probe connected to a vector network analyzer. In addition, a maximum read distance of a fabricated RFID transponder was measured.

Early screening of an infant's visual system

NASA Astrophysics Data System (ADS)

Costa, Manuel F. M.; Jorge, Jorge M.

1999-06-01

It is of utmost importance to the development of the child's visual system that she perceives clear focused retinal images. Furthermore if the refractive problems are not corrected in due time amblyopia may occur--myopia and hyperopia can only cause important problems in the future when they are significantly large, however for the astigmatism (rather frequent in infants) and anisometropia the problems tend to be more stringent. The early evaluation of the visual status of human infants is thus of critical importance. Photorefraction is a convenient technique for this kind of subjects. Essentially a light beam is delivered into the eyes. It is refracted by the ocular media, strikes the retina, focusing or not, reflects off and is collected by a camera. The photorefraction setup we established using new technological breakthroughs on the fields of imaging devices, digital image processing and fiber optics, allows a fast noninvasive evaluation of children visual status (refractive errors, accommodation, strabismus, ...). Results of the visual screening of a group of risk' child descents of blinds or amblyopes will be presented.

Biosensing with Paper-Based Miniaturized Printed Electrodes-A Modern Trend.

PubMed

Silveira, Célia M; Monteiro, Tiago; Almeida, Maria Gabriela

2016-09-28

From the bench-mark work on microfluidics from the Whitesides's group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors.

The MM5 Numerical Model to Correct PSInSAR Atmospheric Phase Screen

NASA Astrophysics Data System (ADS)

Perissin, D.; Pichelli, E.; Ferretti, R.; Rocca, F.; Pierdicca, N.

2010-03-01

In this work we make an experimental analysis to research the capability of Numerical Weather Prediction (NWP) models as MM5 to produce high resolution (1km-500m) maps of Integrated Water Vapour (IWV) in the atmosphere to mitigate the well-known disturbances that affect the radar signal while travelling from the sensor to the ground and back. Experiments have been conducted over the area surrounding Rome using ERS data acquired during the three days phase in '94 and using Envisat data acquired in recent years. By means of the PS technique SAR data have been processed and the Atmospheric Phase Screen (APS) of Slave images with respect to a reference Master have been extracted. MM5 IWV maps have a much lower resolution than PSInSAR APS's: the turbulent term of the atmospheric vapour field cannot be well resolved by MM5, at least with the low resolution ECMWF inputs. However, the vapour distribution term that depends on the local topography has been found quite in accordance.

Biosensing with Paper-Based Miniaturized Printed Electrodes–A Modern Trend

PubMed Central

Silveira, Célia M.; Monteiro, Tiago; Almeida, Maria Gabriela

2016-01-01

From the bench-mark work on microfluidics from the Whitesides’s group in 2007, paper technology has experienced significant growth, particularly regarding applications in biomedical research and clinical diagnostics. Besides the structural properties supporting microfluidics, other advantageous features of paper materials, including their versatility, disposability and low cost, show off the great potential for the development of advanced and eco-friendly analytical tools. Consequently, paper was quickly employed in the field of electrochemical sensors, being an ideal material for producing custom, tailored and miniaturized devices. Stencil-, inkjet-, or screen-printing are the preferential techniques for electrode manufacturing. Not surprisingly, we witnessed a rapid increase in the number of publications on paper based screen-printed sensors at the turn of the past decade. Among the sensing strategies, various biosensors, coupling electrochemical detectors with biomolecules, have been proposed. This work provides a critical review and a discussion on the future progress of paper technology in the context of miniaturized printed electrochemical biosensors. PMID:27690119

Comparative Performance of Multivariable Agro-Physiological Parameters for Detecting Salt Tolerance of Wheat Cultivars under Simulated Saline Field Growing Conditions

PubMed Central

El-Hendawy, Salah E.; Hassan, Wael M.; Al-Suhaibani, Nasser A.; Refay, Yahya; Abdella, Kamel A.

2017-01-01

Field-based trials are crucial for successfully achieving the goals of plant breeding programs aiming to screen and improve the salt tolerance of crop genotypes. In this study, simulated saline field growing conditions were designed using the subsurface water retention technique (SWRT) and three saline irrigation levels (control, 60, and 120 mM NaCl) to accurately appraise the suitability of a set of agro-physiological parameters including shoot biomass, grain yield, leaf water relations, gas exchange, chlorophyll fluorescence, and ion accumulation as screening criteria to establish the salt tolerance of the salt-tolerant (Sakha 93) and salt-sensitive (Sakha 61) wheat cultivars. Shoot dry weight and grain yield per hectare were substantially reduced by salinity, but the reduction was more pronounced in Sakha 61 than in Sakha 93. Increasing salinity stress caused a significant decrease in the net photosynthesis rate and stomatal conductance of both cultivars, although their leaf turgor pressure increased. The accumulation of toxic ions (Na+ and Cl-) was higher in Sakha 61, but the accumulation of essential cations (K+ and Ca2+) was higher in Sakha 93, which could be the reason for the observed maintenance of the higher leaf turgor of both cultivars in the salt treatments. The maximum quantum PSII photochemical efficiency (Fv/Fm) and the PSII quantum yield (ΦPSII) decreased with increasing salinity levels in Sakha 61, but they only started to decline at the moderate salinity condition in Sakha 93. The principle component analysis successfully identified the interrelationships between all parameters. The parameters of leaf water relations and toxic ion concentrations were significantly related to each other and could identify Sakha 61 at mild and moderate salinity levels, and, to a lesser extent, Sakha 93 at the moderate salinity level. Both cultivars under the control treatment and Sakha 93 at the mild salinity level were identified by most of the other parameters. The variability in the angle between the vectors of parameters explained which parameters could be used as individual, interchangeable, or supplementary screening criteria for evaluating wheat salt tolerance under simulated field conditions. PMID:28424718

Surface electromyography as a screening method for evaluation of dysphagia and odynophagia

PubMed Central

Vaiman, Michael; Eviatar, Ephraim

2009-01-01

Objective Patients suspected of having swallowing disorders, could highly benefit from simple diagnostic screening before being referred to specialist evaluations. The article analyzes various instrumental methods of dysphagia assessment, introduces surface electromyography (sEMG) to carry out rapid assessment of such patients, and debates proposed suggestions for sEMG screening protocol in order to identify abnormal deglutition. Data sources Subject related books and articles from 1813 to 2007 were obtained through library search, MEDLINE (1949–2007) and EMBASE (1975–2007). Methods Specifics steps for establishing the protocol for applying the technique for screening purposes (e.g., evaluation of specific muscles), the requirements for diagnostic sEMG equipment, the sEMG technique itself, and defining the tests suitable for assessing deglutition (e.g., saliva, normal, and excessive swallows and uninterrupted drinking of water) are presented in detail. SEMG is compared with other techniques in terms of cost, timing, involvement of radiation, etc. Results According to the published data, SEMG of swallowing is a simple and reliable method for screening and preliminary differentiation among dysphagia and odynophagia of various origins. This noninvasive radiation-free examination has a low level of discomfort, and is simple, time-saving and inexpensive to perform. The major weakness of the method seems to be inability for precise diagnostic of neurologically induced dysphagia. Conclusion With standardization of the technique and an established normative database, sEMG might serve as a reliable screening method for optimal patient management but cannot serve for proper investigation of neurogenic dysphagia. PMID:19232090

Comparison of Adsorbed Mercury Screening Method With Cold-Vapor Atomic Absorption Spectrophotometry for Determination of Mercury in Soil

NASA Technical Reports Server (NTRS)

Easterling, Donald F.; Hovanitz, Edward S.; Street, Kenneth W.

2000-01-01

A field screening method for the determination of elemental mercury in environmental soil samples involves the thermal desorption of the mercury from the sample onto gold and then the thermal desorption from the gold to a gold-film mercury vapor analyzer. This field screening method contains a large number of conditions that could be optimized for the various types of soils encountered. In this study, the conditions were optimized for the determination of mercury in silty clay materials, and the results were comparable to the cold-vapor atomic absorption spectrophotometric method of determination. This paper discusses the benefits and disadvantages of employing the field screening method and provides the sequence of conditions that must be optimized to employ this method of determination on other soil types.

Concise review: modeling central nervous system diseases using induced pluripotent stem cells.

PubMed

Zeng, Xianmin; Hunsberger, Joshua G; Simeonov, Anton; Malik, Nasir; Pei, Ying; Rao, Mahendra

2014-12-01

Induced pluripotent stem cells (iPSCs) offer an opportunity to delve into the mechanisms underlying development while also affording the potential to take advantage of a number of naturally occurring mutations that contribute to either disease susceptibility or resistance. Just as with any new field, several models of screening are being explored, and innovators are working on the most efficient methods to overcome the inherent limitations of primary cell screens using iPSCs. In the present review, we provide a background regarding why iPSCs represent a paradigm shift for central nervous system (CNS) disease modeling. We describe the efforts in the field to develop more biologically relevant CNS disease models, which should provide screening assays useful for the pharmaceutical industry. We also provide some examples of successful uses for iPSC-based screens and suggest that additional development could revolutionize the field of drug discovery. The development and implementation of these advanced iPSC-based screens will create a more efficient disease-specific process underpinned by the biological mechanism in a patient- and disease-specific manner rather than by trial-and-error. Moreover, with careful and strategic planning, shared resources can be developed that will enable exponential advances in the field. This will undoubtedly lead to more sensitive and accurate screens for early diagnosis and allow the identification of patient-specific therapies, thus, paving the way to personalized medicine. ©AlphaMed Press.

Compatibility of Automatic Exposure Control with New Screen Phosphors in Diagnostic Roentgenography.

NASA Astrophysics Data System (ADS)

Mulvaney, James Arthur

1982-03-01

Automatic exposure control systems are used in diagnostic roentgenography to obtain proper film density for a variety of patient examinations and roentgenographic techniques. Most automatic exposure control systems have been designed for use with par speed, calcium tungstate intensifying screens. The use of screens with faster speeds and new phosphor materials has put extreme demands on present systems. The performance of a representative automatic exposure control system is investigated to determine its ability to maintain constant film density over a wide range of x-ray tube voltages and acrylic phantom thicknesses with four different intensifying screen phosphors. The effects of x-ray energy dependence, generator switching time and stored change are investigated. The system is able to maintain film density to within plus or minus 0.2 optical density units for techniques representing adult patients. A single nonadjustable tube voltage compensation circuit is adequate for the four different screen phosphors for x-ray tube voltages above sixty peak kilovolts. For techniques representing pediatric patients at high x-ray tube voltages, excess film density occurs due to stored charge in the transformer and high-voltage cables. An anticipation circuit in the automatic exposure control circuit can be modified to correct for stored charge effects. In a separate experiment the energy dependence of three different ionization chamber detectors used in automatic exposure control systems is compared directly with the energy dependence of three different screen phosphors. The data on detector sensitivity and screen speed are combined to predict the best tube voltage compensation for each combination of screen and detector.

A New Versatile Microarray-based Method for High Throughput Screening of Carbohydrate-active Enzymes*

PubMed Central

Vidal-Melgosa, Silvia; Pedersen, Henriette L.; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B.; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G. T.

2015-01-01

Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. PMID:25657012

Minimally invasive screening for colitis using attenuated total internal reflectance Fourier transform infrared spectroscopy

PubMed Central

Titus, Jitto; Viennois, Emilie; Merlin, Didier; Perera, A. G. Unil

2016-01-01

This article describes a rapid, simple and cost-effective technique that could lead to a screening method for colitis without the need for biopsies or in vivo measurements. This screening technique includes the testing of serum using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy for the colitis-induced increased presence of mannose. Chronic (Interleukin 10 knockout) and acute (Dextran Sodium Sulphate-induced) models for colitis are tested using the ATR-FTIR technique. Arthritis (Collagen Antibody Induced Arthritis) and metabolic syndrome (Toll like receptor 5 knockout) models are also tested as controls. The marker identified as mannose uniquely screens and distinguishes the colitic from the non-colitic samples and the controls. The reference or the baseline spectrum could be the pooled and averaged spectra of non-colitic samples or the subject's previous sample spectrum. This shows the potential of having individualized route maps of disease status, leading to personalized diagnosis and drug management. PMID:27094092

Prediction of success in FAA air traffic control field training as a function of selection and screening test performance.

DOT National Transportation Integrated Search

1989-05-01

This study compared correlations between Office of Personnel Management (OPM) selection test scores for Air Traffic Control Specialists (ATCSs) and scores from the FAA Academy's second-stage screening program with measures of field training performan...

Chemical genomics in plant biology.

PubMed

Sadhukhan, Ayan; Sahoo, Lingaraj; Panda, Sanjib Kumar

2012-06-01

Chemical genomics is a newly emerged and rapidly progressing field in biology, where small chemical molecules bind specifically and reversibly to protein(s) to modulate their function(s), leading to the delineation and subsequent unravelling of biological processes. This approach overcomes problems like lethality and redundancy of classical genetics. Armed with the powerful techniques of combinatorial synthesis, high-throughput screening and target discovery chemical genomics expands its scope to diverse areas in biology. The well-established genetic system of Arabidopsis model allows chemical genomics to enter into the realm of plant biology exploring signaling pathways of growth regulators, endomembrane signaling cascades, plant defense mechanisms and many more events.

Can Technology Improve the Quality of Colonoscopy?

PubMed

Thirumurthi, Selvi; Ross, William A; Raju, Gottumukkala S

2016-07-01

In order for screening colonoscopy to be an effective tool in reducing colon cancer incidence, exams must be performed in a high-quality manner. Quality metrics have been presented by gastroenterology societies and now include higher adenoma detection rate targets than in the past. In many cases, the quality of colonoscopy can often be improved with simple low-cost interventions such as improved procedure technique, implementing split-dose bowel prep, and monitoring individuals' performances. Emerging technology has expanded our field of view and image quality during colonoscopy. We will critically review several technological advances in the context of quality metrics and discuss if technology can really improve the quality of colonoscopy.

Endoscopic detection of murine colonic dysplasia using a novel fluorescence-labeled peptide

NASA Astrophysics Data System (ADS)

Miller, Sharon J.; Joshi, Bishnu P.; Gaustad, Adam; Fearon, Eric R.; Wang, Thomas D.

2011-03-01

Current endoscopic screening does not detect all pre-malignant (dysplastic) colorectal mucosa, thus requiring the development of more sensitive, targeted techniques to improve detection. The presented work utilizes phage display to identify a novel peptide binder to colorectal dysplasia in a CPC;Apc mouse model. A wide-field, small animal endoscope capable of fluorescence excitation (450-475 nm) identified polyps via white light and also collected fluorescence images (510 nm barrier filter) of peptide binding. The peptide bound ~2-fold greater to the colonic adenomas when compared to the control peptide. We have imaged fluorescence-labeled peptide binding in vivo that is specific towards distal colonic adenomas.

Fiber optic engine for micro projection display.

PubMed

Arabi, Hesam Edin; An, Sohee; Oh, Kyunghwan

2010-03-01

A novel compact optical engine for a micro projector display is experimentally demonstrated, which is composed of RGB light sources, a tapered 3 x 1 Fiber Optic Color Synthesizer (FOCS) along with a fiberized ball-lens, and a two dimensional micro electromechanical scanning mirror. In the proposed optical engine, we successfully employed an all-fiber beam shaping technique combining optical fiber taper and fiberized ball lens that can render a narrow beam and enhance the resolution of the screened image in the far field. Optical performances of the proposed device assembly are investigated in terms of power loss, collimating strength of the collimator assembly, and color gamut of the output.

Nonlinear Real-Time Optical Signal Processing

DTIC Science & Technology

1990-09-01

pattern recognition. Additional work concerns the relationship of parallel computation paradigms to optical computing and halftone screen techniques...paradigms to optical computing and halftone screen techniques for implementing general nonlinear functions. 3\\ 2 Research Progress This section...Vol. 23, No. 8, pp. 34-57, 1986. 2.4 Nonlinear Optical Processing with Halftones : Degradation and Compen- sation Models This paper is concerned with

In Vitro Toxicity Screening Technique for Volatile Substances Using Flow-Through System#

EPA Science Inventory

In 2007 the National Research Council envisioned the need for inexpensive, high throughput, cell based toxicity testing methods relevant to human health. High Throughput Screening (HTS) in vitro screening approaches have addressed these problems by using robotics. However the cha...

Probing dark energy with atom interferometry

NASA Astrophysics Data System (ADS)

Burrage, Clare; Copeland, Edmund J.; Hinds, E. A.

2015-03-01

Theories of dark energy require a screening mechanism to explain why the associated scalar fields do not mediate observable long range fifth forces. The archetype of this is the chameleon field. Here we show that individual atoms are too small to screen the chameleon field inside a large high-vacuum chamber, and therefore can detect the field with high sensitivity. We derive new limits on the chameleon parameters from existing experiments, and show that most of the remaining chameleon parameter space is readily accessible using atom interferometry.

Advanced space propulsion thruster research

NASA Technical Reports Server (NTRS)

Wilbur, P. J.

1981-01-01

Experiments showed that stray magnetic fields can adversely affect the capacity of a hollow cathode neutralizer to couple to an ion beam. Magnetic field strength at the neutralizer cathode orifice is a crucial factor influencing the coupling voltage. The effects of electrostatic accelerator grid aperture diameters on the ion current extraction capabilities were examined experimentally to describe the divergence, deflection, and current extraction capabilities of grids with the screen and accelerator apertures displaced relative to one another. Experiments performed in orificed, mercury hollow cathodes support the model of field enhanced thermionic electron mission from cathode inserts. Tests supported the validity of a thermal model of the cathode insert. A theoretical justification of a Saha equation model relating cathode plasma properties is presented. Experiments suggest that ion loss rates to discharge chamber walls can be controlled. A series of new discharge chamber magnetic field configurations were generated in the flexible magnetic field thruster and their effect on performance was examined. A technique used in the thruster to measure ion currents to discharge chamber walls is described. Using these ion currents the fraction of ions produced that are extracted from the discharge chamber and the energy cost of plasma ions are computed.

Five years later: the current status of the use of proteomics and transcriptomics in EMF research.

PubMed

Leszczynski, Dariusz; de Pomerai, David; Koczan, Dirk; Stoll, Dieter; Franke, Helmut; Albar, Juan Pablo

2012-08-01

The World Health Organization's and Radiation and Nuclear Safety Authority's "Workshop on Application of Proteomics and Transcriptomics in Electromagnetic Fields Research" was held in Helsinki in the October/November 2005. As a consequence of this meeting, Proteomics journal published in 2006 a special issue "Application of Proteomics and Transcriptomics in EMF Research" (Vol. 6 No. 17; Guest Editor: D. Leszczynski). This Proteomics issue presented the status of research, of the effects of electromagnetic fields (EMF) using proteomics and transcriptomics methods, present in 2005. The current overview/opinion article presents the status of research in this area by reviewing all studies that were published by the end of 2010. The review work was a part of the European Cooperation in the Field of Scientific and Technical Research (COST) Action BM0704 that created a structure in which researchers in the field of EMF and health shared knowledge and information. The review was prepared by the members of the COST Action BM0704 task group on the high-throughput screening techniques and electromagnetic fields (TG-HTST-EMF). © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Second generation codon optimized minicircle (CoMiC) for nonviral reprogramming of human adult fibroblasts.

PubMed

Diecke, Sebastian; Lisowski, Leszek; Kooreman, Nigel G; Wu, Joseph C

2014-01-01

The ability to induce pluripotency in somatic cells is one of the most important scientific achievements in the fields of stem cell research and regenerative medicine. This technique allows researchers to obtain pluripotent stem cells without the controversial use of embryos, providing a novel and powerful tool for disease modeling and drug screening approaches. However, using viruses for the delivery of reprogramming genes and transcription factors may result in integration into the host genome and cause random mutations within the target cell, thus limiting the use of these cells for downstream applications. To overcome this limitation, various non-integrating techniques, including Sendai virus, mRNA, minicircle, and plasmid-based methods, have recently been developed. Utilizing a newly developed codon optimized 4-in-1 minicircle (CoMiC), we were able to reprogram human adult fibroblasts using chemically defined media and without the need for feeder cells.

Application of Advanced Atomic Force Microscopy Techniques to Study Quantum Dots and Bio-materials

NASA Astrophysics Data System (ADS)

Guz, Nataliia

In recent years, there has been an increase in research towards micro- and nanoscale devices as they have proliferated into diverse areas of scientific exploration. Many of the general fields of study that have greatly affected the advancement of these devices includes the investigation of their properties. The sensitivity of Atomic Force Microscopy (AFM) allows detecting charges up to the single electron value in quantum dots in ambient conditions, the measurement of steric forces on the surface of the human cell brush, determination of cell mechanics, magnetic forces, and other important properties. Utilizing AFM methods, the fast screening of quantum dot efficiency and the differences between cancer, normal (healthy) and precancer (immortalized) human cells has been investigated. The current research using AFM techniques can help to identify biophysical differences of cancer cells to advance our understanding of the resistance of the cells against the existing medicine.

Integrated light-sheet imaging and flow-based enquiry (iLIFE) system for 3D in-vivo imaging of multicellular organism

NASA Astrophysics Data System (ADS)

Rasmi, Chelur K.; Padmanabhan, Sreedevi; Shirlekar, Kalyanee; Rajan, Kanhirodan; Manjithaya, Ravi; Singh, Varsha; Mondal, Partha Pratim

2017-12-01

We propose and demonstrate a light-sheet-based 3D interrogation system on a microfluidic platform for screening biological specimens during flow. To achieve this, a diffraction-limited light-sheet (with a large field-of-view) is employed to optically section the specimens flowing through the microfluidic channel. This necessitates optimization of the parameters for the illumination sub-system (illumination intensity, light-sheet width, and thickness), microfluidic specimen platform (channel-width and flow-rate), and detection sub-system (camera exposure time and frame rate). Once optimized, these parameters facilitate cross-sectional imaging and 3D reconstruction of biological specimens. The proposed integrated light-sheet imaging and flow-based enquiry (iLIFE) imaging technique enables single-shot sectional imaging of a range of specimens of varying dimensions, ranging from a single cell (HeLa cell) to a multicellular organism (C. elegans). 3D reconstruction of the entire C. elegans is achieved in real-time and with an exposure time of few hundred micro-seconds. A maximum likelihood technique is developed and optimized for the iLIFE imaging system. We observed an intracellular resolution for mitochondria-labeled HeLa cells, which demonstrates the dynamic resolution of the iLIFE system. The proposed technique is a step towards achieving flow-based 3D imaging. We expect potential applications in diverse fields such as structural biology and biophysics.

Law enforcement tools available at the Savannah River Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hofstetter, K.J.

A number of nuclear technologies developed and applied at the Savannah River Site in support of nuclear weapons material production and environmental remediation can be applied to problems in law enforcement. Techniques and equipment for high-sensitivity analyses of samples are available to identify and quantify trace elements and establish origins and histories of forensic evidence removed from crime scenes. While some of theses capabilities are available at local crime laboratories, state-of-the-art equipment and breakthroughs in analytical techniques are continually being developed at DOE laboratories. Extensive experience with the handling of radioactive samples at the DOE labs minimizes the chances ofmore » cross-contamination of evidence received from law enforcement. In addition to high-sensitivity analyses, many of the field techniques developed for use in a nuclear facility can assist law enforcement personnel in detecting illicit materials and operations, in retrieving of pertinent evidence and in surveying crime scenes. Some of these tools include chemical sniffers, hand-held detectors, thermal imaging, etc. In addition, mobile laboratories can be deployed to a crime scene to provide field screening of potential evidence. A variety of portable sensors can be deployed on vehicle, aerial, surface or submersible platforms to assist in the location of pertinent evidence or illicit operations. Several specific nuclear technologies available to law enforcement and their potential uses are discussed.« less

Novel KCNQ2 channel activators discovered using fluorescence-based and automated patch-clamp-based high-throughput screening techniques

PubMed Central

Yue, Jin-feng; Qiao, Guan-hua; Liu, Ni; Nan, Fa-jun; Gao, Zhao-bing

2016-01-01

Aim: To establish an improved, high-throughput screening techniques for identifying novel KCNQ2 channel activators. Methods: KCNQ2 channels were stably expressed in CHO cells (KCNQ2 cells). Thallium flux assay was used for primary screening, and 384-well automated patch-clamp IonWorks Barracuda was used for hit validation. Two validated activators were characterized using a conventional patch-clamp recording technique. Results: From a collection of 80 000 compounds, the primary screening revealed a total of 565 compounds that potentiated the fluorescence signals in thallium flux assay by more than 150%. When the 565 hits were examined in IonWorks Barracuda, 38 compounds significantly enhanced the outward currents recorded in KCNQ2 cells, and were confirmed as KCNQ2 activators. In the conventional patch-clamp recordings, two validated activators ZG1732 and ZG2083 enhanced KCNQ2 currents with EC50 values of 1.04±0.18 μmol/L and 1.37±0.06 μmol/L, respectively. Conclusion: The combination of thallium flux assay and IonWorks Barracuda assay is an efficient high-throughput screening (HTS) route for discovering KCNQ2 activators. PMID:26725738

Response of chickpea genotypes to Agrobacterium-mediated delivery of Chickpea chlorotic dwarf virus (CpCDV) genome and identification of resistance source.

PubMed

Kanakala, S; Verma, H N; Vijay, P; Saxena, D R; Malathi, V G

2013-11-01

Chickpea stunt disease caused by Chickpea chlorotic dwarf virus (CpCDV) (genus Mastrevirus, family Geminiviridae) is the most important biotic stress affecting chickpea crops worldwide. A survey conducted on the incidence of stunt disease clearly revealed high incidence of the disease with severe symptom expression in both indigenous and imported genotypes. To manage the disease in a sustainable way, resistant genotypes need to be bred by adopting objective and precise assessment of the disease response of chickpea genotypes. At present, evaluation of CpCDV resistance is conducted on the basis of natural infection in the field, which is bound to be erroneous due to vagaries in vector population. To circumvent the above problems, we devised an agroinoculation technique that involves the delivery of viral genomic DNA through Agrobacterium tumefaciens. An objective scoring system assigning quantitative value to different symptoms has been evolved to assess the response of chickpea genotypes to CpCDV inoculation. Using the inoculation and scoring techniques, we screened 70 genotypes, which helped in differentiating field resistance that is more due to resistance to vector feeding than resistance to the virus.

Improving Efficiency of III-N Quantum Well Based Optoelectronic Devices through Active Region Design and Growth Techniques

NASA Astrophysics Data System (ADS)

Young, Nathan Garrett

The III-Nitride materials system provides a fascinating platform for developing optoelectronic devices, such as solar cells and LEDs, which have the power to dramatically improve the efficiency of our power consumption and reduce our environmental footprint. Finding ways to make these devices more efficient is key to driving their widespread adoption. This dissertation focuses on the intersection of challenges in physics and metalorganic chemical vapor deposition (MOCVD) growth at the nanoscale when designing for device efficiency. In order to create the best possible InGaN solar cell, a multiple quantum well (MQW) active region design had to be employed to prevent strain relaxation related degradation. There were two competing challenges for MQW active region design and growth. First, it was observed current collection efficiency improved with thinner quantum barriers, which promoted efficient tunneling transport instead of inefficiency thermally activated escape. Second, GaN barriers could planarize surface defects in the MQW region under the right conditions and when grown thick enough. A two-step growth method for thinner quantum barriers was developed that simultaneously allowed for tunneling transport and planarized V-defects. Barriers as thin as 4 nm were employed in MQW active regions with up to 30 periods without structural or electrical degradation, leading to record performance. Application of dielectric optical coatings greatly reduced surface reflections and allowed a second pass of light through the device. This both demonstrated the feasibility of multijunction solar integration and boosted conversion efficiency to record levels for an InGaN solar cell. III-N LEDs have achieved state-of-the-art performance for decades, but still suffer from the phenomena of efficiency droop, where device efficiency drops dramatically at high power operation. Droop is exacerbated by the polarization-induced electric fields in InGaN quantum wells, which originate from a lack of inversion symmetry in GaN's wurtzite crystal structure. These fields can be screened by using highly doped layers, but the extreme dopant densities predicted by simulation for complete screening may require using Ge as an alternative n-type dopant to Si. GaN:Ge layers with excellent electrical characteristics were grown by MOCVD with doping densities exceeding 1020 cm -3. However, their surface morphologies were very poor and they proved a poor screening dopant in LED structures. Using Si as the n-type screening dopant, LEDs with single QW active regions were grown, packaged, and tested. Biased photoluminescence showed strong evidence of complete polarization screening. The LEDs had low droop, but also low peak efficiencies. Possible explanations for trends in efficiency with varying QW width and field screening will be discussed.

Prediction of Stereochemistry using Q2MM

PubMed Central

2016-01-01

Conspectus The standard method of screening ligands for selectivity in asymmetric, transition metal-catalyzed reactions requires experimental testing of hundreds of ligands from ligand libraries. This “trial and error” process is costly in terms of time as well as resources and, in general, is scientifically and intellectually unsatisfying as it reveals little about the underlying mechanism behind the selectivity. The accurate computational prediction of stereoselectivity in enantioselective catalysis requires adequate conformational sampling of the selectivity-determining transition state but has to be fast enough to compete with experimental screening techniques to be useful for the synthetic chemist. Although electronic structure calculations are accurate and general, they are too slow to allow for sampling or fast screening of ligand libraries. The combined requirements can be fulfilled by using appropriately fitted transition state force fields (TSFFs) that represent the transition state as a minimum and allow fast conformational sampling using Monte Carlo. Quantum-guided molecular mechanics (Q2MM) is an automated force field parametrization method that generates accurate, reaction-specific TSFFs by fitting the functional form of an arbitrary force field using only electronic structure calculations by minimization of an objective function. A key feature that distinguishes the Q2MM method from many other automated parametrization procedures is the use of the Hessian matrix in addition to geometric parameters and relative energies. This alleviates the known problems of overfitting of TSFFs. After validation of the TSFF by comparison to electronic structure results for a test set and available experimental data, the stereoselectivity of a reaction can be calculated by summation over the Boltzman-averaged relative energies of the conformations leading to the different stereoisomers. The Q2MM method has been applied successfully to perform virtual ligand screens on a range of transition metal-catalyzed reactions that are important from both an industrial and an academic perspective. In this Account, we provide an overview of the continued improvement of the prediction of stereochemistry using Q2MM-derived TSFFs using four examples from different stages of development: (i) Pd-catalyzed allylation, (ii) OsO4-catalyzed asymmetric dihydroxylation (AD) of alkenes, (iii) Rh-catalyzed hydrogenation of enamides, and (iv) Ru-catalyzed hydrogenation of ketones. In the current form, correlation coefficients of 0.8–0.9 between calculated and experimental ee values are typical for a wide range of substrate–ligand combinations, and suitable ligands can be predicted for a given substrate with ∼80% accuracy. Although the generation of a TSFF requires an initial effort and will therefore be most useful for widely used reactions that require frequent screening campaigns, the method allows for a rapid virtual screen of large ligand libraries to focus experimental efforts on the most promising substrate–ligand combinations. PMID:27064579

Influence of magnetic fields on the color screening masses

NASA Astrophysics Data System (ADS)

Bonati, Claudio; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Rucci, Andrea; Sanfilippo, Francesco

2018-03-01

We present some recent results obtained in the study of the color magnetic and electric screening masses in the QCD plasma. In particular, we discuss how the masses get modified by strong external fields which are expected to be created in physical situations such as heavy-ion collisions.

Nanoliter-Scale Protein Crystallization and Screening with a Microfluidic Droplet Robot

PubMed Central

Zhu, Ying; Zhu, Li-Na; Guo, Rui; Cui, Heng-Jun; Ye, Sheng; Fang, Qun

2014-01-01

Large-scale screening of hundreds or even thousands of crystallization conditions while with low sample consumption is in urgent need, in current structural biology research. Here we describe a fully-automated droplet robot for nanoliter-scale crystallization screening that combines the advantages of both automated robotics technique for protein crystallization screening and the droplet-based microfluidic technique. A semi-contact dispensing method was developed to achieve flexible, programmable and reliable liquid-handling operations for nanoliter-scale protein crystallization experiments. We applied the droplet robot in large-scale screening of crystallization conditions of five soluble proteins and one membrane protein with 35–96 different crystallization conditions, study of volume effects on protein crystallization, and determination of phase diagrams of two proteins. The volume for each droplet reactor is only ca. 4–8 nL. The protein consumption significantly reduces 50–500 fold compared with current crystallization stations. PMID:24854085

Nanoliter-scale protein crystallization and screening with a microfluidic droplet robot.

PubMed

Zhu, Ying; Zhu, Li-Na; Guo, Rui; Cui, Heng-Jun; Ye, Sheng; Fang, Qun

2014-05-23

Large-scale screening of hundreds or even thousands of crystallization conditions while with low sample consumption is in urgent need, in current structural biology research. Here we describe a fully-automated droplet robot for nanoliter-scale crystallization screening that combines the advantages of both automated robotics technique for protein crystallization screening and the droplet-based microfluidic technique. A semi-contact dispensing method was developed to achieve flexible, programmable and reliable liquid-handling operations for nanoliter-scale protein crystallization experiments. We applied the droplet robot in large-scale screening of crystallization conditions of five soluble proteins and one membrane protein with 35-96 different crystallization conditions, study of volume effects on protein crystallization, and determination of phase diagrams of two proteins. The volume for each droplet reactor is only ca. 4-8 nL. The protein consumption significantly reduces 50-500 fold compared with current crystallization stations.

Risk factors & screening modalities for oral cancer.

PubMed

Chau, Steven

2008-01-01

Dentists are at the forefront for screening oral cancer. In addition to the well known carcinogenic potential of tobacco and alcohol, betel nut chewing and human papilloma virus are important risk factors in the development of oral cancer. To aid in screening and decreasing morbidity and mortality from oral cancer, a variety of techniques have been developed. These techniques show promise but they require additional investigations to determine their usefulness in oral cancer detection. Dentists need to be well educated and vigilant when dealing with all patients they encounter. Early detection, diagnosis and treatment are critical for the effective management of oral cancers.

Canine Hip Dysplasia: Diagnostic Imaging.

PubMed

Butler, J Ryan; Gambino, Jennifer

2017-07-01

Diagnostic imaging is the principal method used to screen for and diagnose hip dysplasia in the canine patient. Multiple techniques are available, each having advantages, disadvantages, and limitations. Hip-extended radiography is the most used method and is best used as a screening tool and for assessment for osteoarthritis. Distraction radiographic methods such as the PennHip method allow for improved detection of laxity and improved ability to predict future osteoarthritis development. More advanced techniques such as MRI, although expensive and not widely available, may improve patient screening and allow for improved assessment of cartilage health. Copyright © 2017 Elsevier Inc. All rights reserved.

Fpga based hardware synthesis for automatic segmentation of retinal blood vessels in diabetic retinopathy images.

PubMed

Sivakamasundari, J; Kavitha, G; Sujatha, C M; Ramakrishnan, S

2014-01-01

Diabetic Retinopathy (DR) is a disorder that affects the structure of retinal blood vessels due to long-standing diabetes mellitus. Real-Time mass screening system for DR is vital for timely diagnosis and periodic screening to prevent the patient from severe visual loss. Human retinal fundus images are widely used for an automated segmentation of blood vessel and diagnosis of various blood vessel disorders. In this work, an attempt has been made to perform hardware synthesis of Kirsch template based edge detection for segmentation of blood vessels. This method is implemented using LabVIEW software and is synthesized in field programmable gate array board to yield results in real-time application. The segmentation of blood vessels using Kirsch based edge detection is compared with other edge detection methods such as Sobel, Prewitt and Canny. The texture features such as energy, entropy, contrast, mean, homogeneity and structural feature namely ratio of vessel to vessel free area are obtained from the segmented images. The performance of segmentation is analysed in terms of sensitivity, specificity and accuracy. It is observed from the results that the Kirsch based edge detection technique segmented the edges of blood vessels better than other edge detection techniques. The ratio of vessel to vessel free area classified the normal and DR affected retinal images more significantly than other texture based features. FPGA based hardware synthesis of Kirsch edge detection method is able to differentiate normal and diseased images with high specificity (93%). This automated segmentation of retinal blood vessels system could be used in computer-assisted diagnosis for diabetic retinopathy screening in real-time application.

Cone penetrometer testing and discrete-depth ground water sampling techniques: A cost-effective method of site characterization in a multiple-aquifer setting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zemo, D.A.; Pierce, Y.G.; Gallinatti, J.D.

Cone penetrometer testing (CPT), combined with discrete-depth ground water sampling methods, can significantly reduce the time and expense required to characterize large sites that have multiple aquifers. Results from the screening site characterization can then be used to design and install a cost-effective monitoring well network. At a site in northern California, it was necessary to characterize the stratigraphy and the distribution of volatile organic compounds (VOCs). To expedite characterization, a five-week field screening program was implemented that consisted of a shallow ground water survey, CPT soundings and pore-pressure measurements, and discrete-depth ground water sampling. Based on continuous lithologic informationmore » provided by the CPT soundings, four predominantly coarse-grained, water yielding stratigraphic packages were identified. Seventy-nine discrete-depth ground water samples were collected using either shallow ground water survey techniques, the BAT Enviroprobe, or the QED HydroPunch I, depending on subsurface conditions. Using results from these efforts, a 20-well monitoring network was designed and installed to monitor critical points within each stratigraphic package. Good correlation was found for hydraulic head and chemical results between discrete-depth screening data and monitoring well data. Understanding the vertical VOC distribution and concentrations produced substantial time and cost savings by minimizing the number of permanent monitoring wells and reducing the number of costly conductor casings that had to be installed. Additionally, significant long-term cost savings will result from reduced sampling costs, because fewer wells comprise the monitoring network. The authors estimate these savings to be 50% for site characterization costs, 65% for site characterization time, and 60% for long-term monitoring costs.« less

Wireless power transfer magnetic couplers

DOEpatents

Wu, Hunter; Gilchrist, Aaron; Sealy, Kylee

2016-01-19

A magnetic coupler is disclosed for wireless power transfer systems. A ferrimagnetic component is capable of guiding a magnetic field. A wire coil is wrapped around at least a portion of the ferrimagnetic component. A screen is capable of blocking leakage magnetic fields. The screen may be positioned to cover at least one side of the ferrimagnetic component and the coil. A distance across the screen may be at least six times an air gap distance between the ferrimagnetic component and a receiving magnetic coupler.

Nonlinear conductance in weakly disordered mesoscopic wires: Interaction and magnetic field asymmetry

NASA Astrophysics Data System (ADS)

Texier, Christophe; Mitscherling, Johannes

2018-02-01

We study the nonlinear conductance G ˜∂2I /∂ V2|V =0 in coherent quasi-one-dimensional weakly disordered metallic wires. Our analysis is based on the scattering approach and includes the effect of Coulomb interaction. The nonlinear conductance correlations can be related to integrals of two fundamental correlation functions: the correlator of functional derivatives of the conductance and the correlator of injectivities (the injectivity is the contribution to the local density of states of eigenstates incoming from one contact). These correlators are obtained explicitly by using diagrammatic techniques for weakly disordered metals. In a coherent wire of length L , we obtain rms (G )≃0.006 ETh-1 (and =0 ), where ETh=ℏ D /L2 is the Thouless energy of the wire and D the diffusion constant; the small dimensionless factor results from screening, i.e., cannot be obtained within a simple theory for noninteracting electrons. Electronic interactions are also responsible for an asymmetry under magnetic field reversal; the antisymmetric part of the nonlinear conductance (at high magnetic field) being much smaller than the symmetric one, rms (Ga)≃0.001 (gETh) -1 , where g ≫1 is the dimensionless (linear) conductance of the wire. In a weakly coherent wire (i.e., Lφ≪L , where Lφ is the phase coherence length), the nonlinear conductance is of the same order as the result G0 of a free electron calculation (although screening again strongly reduces the dimensionless prefactor); we get G ˜G0˜(Lφ/L ) 7 /2ETh-1 , while the antisymmetric part (at high magnetic field) now behaves as Ga˜(Lφ/L ) 11 /2(gETh) -1≪G . The effect of thermal fluctuations is studied: when the thermal length LT=√{ℏ D /kBT } is the smallest length scale, LT≪Lφ≪L , the free electron result G0˜(LT/L ) 3(Lφ/L ) 1 /2ETh-1 is negligible and the dominant contribution is provided by screening, G ˜(LT/L ) (Lφ/L ) 7 /2ETh-1 ; in this regime, the antisymmetric part is Ga˜(LT/L ) 2(Lφ/L ) 7 /2(gETh) -1 . All the precise dimensionless prefactors are obtained. Crossovers from zero to strong magnetic field regimes are also analyzed.

Screening and Spectral Summing of LANL Empty Waste Drums - 13226

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruetzmacher, Kathleen M.; Bustos, Roland M.; Ferran, Scott G.

2013-07-01

Empty 55-gallon drums that formerly held transuranic (TRU) waste (often over-packed in 85- gallon drums) are generated at LANL and require radiological characterization for disposition. These drums are typically measured and analyzed individually using high purity germanium (HPGe) gamma detectors. This approach can be resource and time intensive. For a project requiring several hundred drums to be characterized in a short time frame, an alternative approach was developed. The approach utilizes a combination of field screening and spectral summing that was required to be technically defensible and meet the Nevada Nuclear Security Site (NNSS) Waste Acceptance Criteria (WAC). In themore » screening phase of the operation, the drums were counted for 300 seconds (compared to 600 seconds for the typical approach) and checked against Low Level (LL)/TRU thresholds established for each drum configuration and detector. Multiple TRU nuclides and multiple gamma rays for each nuclide were evaluated using an automated spreadsheet utility that can process data from up to 42 drums at a time. Screening results were reviewed by an expert analyst to confirm the field LL/TRU determination. The spectral summing analysis technique combines spectral data (channel-by-channel) associated with a group of individual waste containers producing a composite spectrum. The grouped drums must meet specific similarity criteria. Another automated spreadsheet utility was used to spectral sum data from an unlimited number of similar drums grouped together. The composite spectrum represents a virtual combined drum for the group of drums and was analyzed using the SNAP{sup TM}/Radioassay Data Sheet (RDS)/Batch Data Report (BDR) method. The activity results for a composite virtual drum were divided equally amongst the individual drums to generate characterization results for each individual drum in the group. An initial batch of approximately 500 drums were measured and analyzed in less than 2 months in 2011. A second batch of approximately 500 more drums were measured and analyzed during the following 2 1/2 months. Four different HPGe detectors were employed for the operation. The screening and spectral summing approach can reduce the overall measurement and analysis time required. However, developing the technical details and automation spreadsheets requires a significant amount of expert time prior to beginning field operations and must be considered in the overall project schedule. This approach has continued to be used for characterizing several hundred more empty drums in 2012 and is planned to continue in 2013. (authors)« less

Multiloop atom interferometer measurements of chameleon dark energy in microgravity

NASA Astrophysics Data System (ADS)

Chiow, Sheng-wey; Yu, Nan

2018-02-01

Chameleon field is one of the promising candidates of dark energy scalar fields. As in all viable candidate field theories, a screening mechanism is implemented to be consistent with all existing tests of general relativity. The screening effect in the chameleon theory manifests its influence limited only to the thin outer layer of a bulk object, thus producing extra forces orders of magnitude weaker than that of the gravitational force of the bulk. For pointlike particles such as atoms, the depth of screening is larger than the size of the particle, such that the screening mechanism is ineffective and the chameleon force is fully expressed on the atomic test particles. Extra force measurements using atom interferometry are thus much more sensitive than bulk mass based measurements, and indeed have placed the most stringent constraints on the parameters characterizing chameleon field. In this paper, we present a conceptual measurement approach for chameleon force detection using atom interferometry in microgravity, in which multiloop atom interferometers exploit specially designed periodic modulation of chameleon fields. We show that major systematics of the dark energy force measurements, i.e., effects of gravitational forces and their gradients, can be suppressed below all hypothetical chameleon signals in the parameter space of interest.

Chiral separations of cathinone and amphetamine-derivatives: Comparative study between capillary electrochromatography, supercritical fluid chromatography and three liquid chromatographic modes.

PubMed

Albals, Dima; Heyden, Yvan Vander; Schmid, Martin G; Chankvetadze, Bezhan; Mangelings, Debby

2016-03-20

The screening part of an earlier defined chiral separation strategy in capillary electrochromatography (CEC) was used for the separation of ten cathinone- and amphetamine derivatives. They were analyzed using 4 polysaccharide-based chiral stationary phases (CSPs), containing cellulose tris(3,5-dimethylphenylcarbamate) (ODRH), amylose tris(3,5-dimethylphenylcarbamate) (ADH), amylose tris(5-chloro-2-methylphenylcarbamate) (LA2), and cellulose tris(4-chloro-3-methylphenylcarbamate) (LC4) as chiral selectors. After applying the screening to each compound, ADH and LC4 showed the highest success rate. In a second part of the study, a comparison between CEC and other analytical techniques used for chiral separations i.e., supercritical fluid chromatography (SFC), polar organic solvent chromatography (POSC), reversed-phase (RPLC) and normal-phase liquid chromatography (NPLC), was made. For this purpose, earlier defined screening approaches for each technique were applied to separate the 10 test substances. This allowed an overall comparison of the success rates of the screening steps of the 5 techniques for these compounds. The results showed that CEC had a similar enantioselectivity rate as NPLC and RPLC, producing the highest number of separations (9 out of 10 racemates). SFC resolved 7 compounds, while POSC gave only 2 separations. On the other hand, the baseline separation success rates for NPLC and RPLC was better than for CEC. For a second comparison, the same chiral stationary phases as in the CEC screening were also tested with all techniques at their specific screening conditions, which allowed a direct comparison of the performance of CEC versus the same CSPs in the other techniques. This comparison revealed that RPLC was able to separate all tested compounds, and also produced the highest number of baseline separations on the CSP that were used in the CEC screening step. CEC and NPLC showed the same success rate: nine out of ten substances were separated. When CEC and NPLC are combined, separation of the ten compounds can be achieved. SFC and POSC resolved eight and three compounds, respectively. POSC was the least attractive option as it expressed only limited enantioselectivity toward these compounds. Copyright © 2015 Elsevier B.V. All rights reserved.

[Screening of parasitic diseases in the asymptomatic immigrant population].

PubMed

Goterris, Lidia; Bocanegra, Cristina; Serre-Delcor, Núria; Moure, Zaira; Treviño, Begoña; Zarzuela, Francesc; Espasa, Mateu; Sulleiro, Elena

2016-07-01

Parasitic diseases suppose an important health problem in people from high endemic areas, so these must be discarded properly. Usually, these infections develop asymptomatically but, in propitious situations, are likely to reactivate themselves and can cause clinical symptoms and/or complications in the receiving country. Moreover, in some cases it is possible local transmission. Early diagnosis of these parasitic diseases made by appropriate parasitological techniques and its specific treatment will benefit both, the individual and the community. These techniques must be selected according to geoepidemiological criteria, patient's origin, migration route or time spent outside the endemic area; but other factors must also be considered as its sensitivity and specificity, implementation experience and availability. Given the high prevalence of intestinal parasites on asymptomatic immigrants, it is recommended to conduct a study by coproparasitological techniques. Because of its potential severity, the screening of asymptomatic malaria with sensitive techniques such as PCR (polymerase chain reaction) is also advisable. Serological screening for Chagas disease should be performed on all Latin American immigrants, except for people from the Caribbean islands. Other important parasites, which should be excluded, are filariasis and urinary schistosomiasis, by using microscopic examination. The aim of this paper is to review the different techniques for the screening of parasitic diseases and its advices within the care protocols for asymptomatic immigrants. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Theory and application of high temperature superconducting eddy current probes for nondestructive evaluation

NASA Astrophysics Data System (ADS)

Claycomb, James Ronald

1998-10-01

Several High-T c Superconducting (HTS) eddy current probes have been developed for applications in electromagnetic nondestructive evaluation (NDE) of conducting materials. The probes utilize high-T c SUperconducting Quantum Interference Device (SQUID) magnetometers to detect the fields produced by the perturbation of induced eddy currents resulting from subsurface flaws. Localized HTS shields are incorporated to selectively screen out environmental electromagnetic interference and enable movement of the instrument in the Earth's magnetic field. High permeability magnetic shields are employed to focus flux into, and thereby increase the eddy current density in the metallic test samples. NDE test results are presented, in which machined flaws in aluminum alloy are detected by probes of different design. A novel current injection technique performing NDE of wires using SQUIDs is also discussed. The HTS and high permeability shields are designed based on analytical and numerical finite element method (FEM) calculations presented here. Superconducting and high permeability magnetic shields are modeled in uniform noise fields and in the presence of dipole fields characteristic of flaw signals. Several shield designs are characterized in terms of (1) their ability to screen out uniform background noise fields; (2) the resultant improvement in signal-to-noise ratio and (3) the extent to which dipole source fields are distorted. An analysis of eddy current induction is then presented for low frequency SQUID NDE. Analytical expressions are developed for the induced eddy currents and resulting magnetic fields produced by excitation sources above conducting plates of varying thickness. The expressions derived here are used to model the SQUID's response to material thinning. An analytical defect model is also developed, taking into account the attenuation of the defect field through the conducting material, as well as the current flow around the edges of the flaw. Time harmonic FEM calculations are then used to model the electromagnetic response of eight probe designs, consisting of an eddy current drive coil coupled to a SQUID surrounded by superconducting and/or high permeability magnetic shielding. Simulations are carried out with the eddy current probes located a finite distance above a conducting surface. Results are quantified in terms of shielding and focus factors for each probe design.

Digital mammography: more microcalcifications, more columnar cell lesions without atypia.

PubMed

Verschuur-Maes, Anoek H J; van Gils, Carla H; van den Bosch, Maurice A A J; De Bruin, Peter C; van Diest, Paul J

2011-09-01

The incidence of columnar cell lesions in breast core needle biopsies since full-field digital mammography in comparison with screen-filmed mammography was analyzed. As tiny microcalcifications characterize columnar cell lesions at mammography, we hypothesized that more columnar cell lesions are diagnosed since full-field digital mammography due to its higher sensitivity for microcalcifications. In all, 3437 breast core needle biopsies performed in three hospitals and resulting from in total 55 159 mammographies were revised: 1424 taken in the screen-filmed mammography and 2013 in the full-field digital mammography period. Between the screen-filmed mammography and full-field digital mammography periods, we compared the proportion of mammographies that led to core needle biopsies, the mammographic indication for core needle biopsies (density, microcalcifications, or both) and the proportion of columnar cell lesions with or without atypia. The columnar cell lesions were graded according to Schnitt, and we included atypical ductal hyperplasia arising in the context of columnar cell lesions. Proportions were compared using χ(2) tests and prevalence ratios were adjusted for age and hospital. We found that more core needle biopsies per mammogram were taken in the full-field digital mammography period (7.6%) compared with the screen-filmed mammography period (5.0%, P<0.0001). Microcalcifications were more often diagnosed with full-field digital mammography than with screen-filmed mammography (adjusted prevalence ratio: 1.14, confidence interval 95%: 1.01-1.28). Core needle biopsies from the full-field digital mammography era showed more columnar cell lesions (10.8%) than those from the screen-filmed mammography era (4.9%; adjusted prevalence ratio: 1.93, confidence interval 95%: 1.48-2.51), particularly due to more columnar cell lesions without atypia (8.2% respectively 2.8%) while the proportion of columnar cell lesions with atypia remained nearly constant (2.0 vs 2.6%). In conclusion, since the implementation of full-field digital mammography, more microcalcifications are seen at mammography, more often resulting in core needle biopsies, which especially yields more columnar cell lesions without atypia.

Utility of High Throughput Screening Techniques to Predict Stability of Monoclonal Antibody Formulations During Early Stage Development.

PubMed

Goldberg, Deborah S; Lewus, Rachael A; Esfandiary, Reza; Farkas, David C; Mody, Neil; Day, Katrina J; Mallik, Priyanka; Tracka, Malgorzata B; Sealey, Smita K; Samra, Hardeep S

2017-08-01

Selecting optimal formulation conditions for monoclonal antibodies for first time in human clinical trials is challenging due to short timelines and reliance on predictive assays to ensure product quality and adequate long-term stability. Accelerated stability studies are considered to be the gold standard for excipient screening, but they are relatively low throughput and time consuming. High throughput screening (HTS) techniques allow for large amounts of data to be collected quickly and easily, and can be used to screen solution conditions for early formulation development. The utility of using accelerated stability compared to HTS techniques (differential scanning light scattering and differential scanning fluorescence) for early formulation screening was evaluated along with the impact of excipients of various types on aggregation of monoclonal antibodies from multiple IgG subtypes. The excipient rank order using quantitative HTS measures was found to correlate with accelerated stability aggregation rate ranking for only 33% (by differential scanning fluorescence) to 42% (by differential scanning light scattering) of the antibodies tested, due to the high intrinsic stability and minimal impact of excipients on aggregation rates and HTS data. Also explored was a case study of employing a platform formulation instead of broader formulation screening for early formulation development. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

A new real-time PCR protocol for detection of avian haemosporidians.

PubMed

Bell, Jeffrey A; Weckstein, Jason D; Fecchio, Alan; Tkach, Vasyl V

2015-07-19

Birds possess the most diverse assemblage of haemosporidian parasites; including three genera, Plasmodium, Haemoproteus, and Leucocytozoon. Currently there are over 200 morphologically identified avian haemosporidian species, although true species richness is unknown due to great genetic diversity and insufficient sampling in highly diverse regions. Studies aimed at surveying haemosporidian diversity involve collecting and screening samples from hundreds to thousands of individuals. Currently, screening relies on microscopy and/or single or nested standard PCR. Although effective, these methods are time and resource consuming, and in the case of microscopy require substantial expertise. Here we report a newly developed real-time PCR protocol designed to quickly and reliably detect all three genera of avian haemosporidians in a single biochemical reaction. Using available DNA sequences from avian haemosporidians we designed primers R330F and R480RL, which flank a 182 base pair fragment of mitochondrial conserved rDNA. These primers were initially tested using real-time PCR on samples from Malawi, Africa, previously screened for avian haemosporidians using traditional nested PCR. Our real time protocol was further tested on 94 samples from the Cerrado biome of Brazil, previously screened using a single PCR assay for haemosporidian parasites. These samples were also amplified using modified nested PCR protocols, allowing for comparisons between the three different screening methods (single PCR, nested PCR, real-time PCR). The real-time PCR protocol successfully identified all three genera of avian haemosporidians from both single and mixed infections previously detected from Malawi. There was no significant difference between the three different screening protocols used for the 94 samples from the Brazilian Cerrado (χ(2) = 0.3429, df = 2, P = 0.842). After proving effective, the real-time protocol was used to screen 2113 Brazilian samples, identifying 693 positive samples. Our real-time PCR assay proved as effective as two widely used molecular screening techniques, single PCR and nested PCR. However, the real-time protocol has the distinct advantage of detecting all three genera in a single reaction, which significantly increases efficiency by greatly decreasing screening time and cost. Our real-time PCR protocol is therefore a valuable tool in the quickly expanding field of avian haemosporidian research.

[Study on spray-drier preparation technology of weitai granules using orthogonal experiments].

PubMed

Qu, Cai-Hong; Yang, Li; Chen, Zhi-Liang

2006-04-01

To screen preparation technique in order to raise the end-product and economical efficiency of spray-drier preparation technology of weitai granules. Newly Fluid-bed-spray-drier-granulation technique was adoped and taken extracting technique, temperature of exit and entry and the matching of accessories as inspecting factors, two levels of each factors, end-product and the water content of semi-finished weitai granules as inspecting marker, the best preparation technique of weitai granules was screened by orthogonal desing. Among the 3 factors, the matching of accessories was most notalbe (P < 0.01), next was the temperature of exit and entry (P < 0.05). However, the extracting technique was of little importance (P > 0.05). The optimum spray-drier granulation technique of weitai granules is A3B1C3.

High-throughput cocrystal slurry screening by use of in situ Raman microscopy and multi-well plate.

PubMed

Kojima, Takashi; Tsutsumi, Shunichirou; Yamamoto, Katsuhiko; Ikeda, Yukihiro; Moriwaki, Toshiya

2010-10-31

Cocrystal has attracted much attention in order to improve poor physicochemical properties, since cocrystal former crystallize with the ionic drugs as well as nonionic drugs. Cocrystal screening was usually conducted by crystallization, slurry and co-grinding techniques, however sensitivity, cost and time for screening were limited because of issues such as dissociation of cocrystal during crystallization and cost and time required for slurry and co-grinding methods. To overcome these issues, novel high-throughput cocrystal slurry screening was developed by using in situ Raman microscope and a multi-well plate. Cocrystal screening of indomethacin was conducted with 46 cocrystal formers and potential cocrystals were prepared on a large scale for the characterization with powder X-ray diffractometry, thermal analysis, and Raman microscopy and (1)H NMR spectroscopy. Compared with the characterization of scale-up cocrystals, the cocrystal screening indicated that indomethacin structured novel cocrystals with D/L-mandelic acid, nicotinamide, lactamide and benzamide which was not obtained in the screening with crystallization technique previously reported. In addition, the screening provided not only information of cocrystal formation within a day but also information of equilibrium of cocrystal formation and polymorphic transformation in one screening. Information obtained in this screening allows effective solid form selection by saving cost and time for the development. Copyright © 2010 Elsevier B.V. All rights reserved.

Multiplex and label-free screening of foodborne pathogens using surface plasmon resonance imaging

USDA-ARS?s Scientific Manuscript database

In order to protect outbreaks caused by foodborne pathogens, more rapid and efficient methods are needed for pathogen screening from food samples. Surface plasmon resonance imaging (SPRi) is an emerging optical technique, which allows for label-free screening of multiple targets simultaneously with ...

Testing the Untestable: A Vision Screening Program for Exceptional Children.

ERIC Educational Resources Information Center

Bishop, Virginia E.; Godolphin, Vivienne

Based on a longitudinal study of vision screening techniques for handicapped children at the Chester County (Pennsylvania) Child Development Center, the paper reports on the development of a battery of effective vision screening methods for children with low functioning handicapped children. Specific tests are described, including the Sheridan…

Effect-size measures as descriptors of assay quality in high-content screening: A brief review of some available methodologies

USDA-ARS?s Scientific Manuscript database

The field of high-content screening (HCS) typically uses measures of screen quality conceived for fairly straightforward high-throughput screening (HTS) scenarios. However, in contrast to HTS, image-based HCS systems rely on multidimensional readouts reporting biological responses associated with co...

Screening Intervals for Diabetic Retinopathy and Implications for Care.

PubMed

Scanlon, Peter H

2017-09-05

The purpose of this study is to review the evidence that lower risk groups who could safely be screened less frequently for sight-threatening diabetic retinopathy (DR) than annually. Data have demonstrated that people with no DR in either eye are at a low risk of progression to sight-threatening DR over a 2-year period (event rate 4.8 per 1000 person years), irrespective of whether the screening method is one-field non-mydriatic or two-field mydriatic digital photography. Low risk has been defined as no retinopathy on two consecutive screening episodes or no retinopathy on one screening episode combined with risk factor data. The risk of an extension to 2 years is less than 5 per 1000 person years in a population with a national screening programme, and the general standard of diabetes care is relatively good, whether low risk is defined as no retinopathy on two consecutive screening episodes or no retinopathy on one screening episode combined with other risk factor data. The definition used in different populations is likely to depend on the availability of data.

Photo screening around the world: Lions Club International Foundation experience.

PubMed

Donahue, Sean P; Lorenz, Sylvia; Johnson, Tammy

2008-01-01

To describe the use of photoscreening for preschool vision screening in several diverse locations throughout the world. The MTI photo screener was used to screen pre-verbal children; photographs were interpreted using standard criteria. The Tennessee vision screening program remains successful, screening over 200,000 children during the past 8 years. Similar programs modeled across the United States have screened an additional 500,000 children. A pilot demonstration project in Hong Kong, Beijing, and Brazil screened over 5000 additional children with good success and appropriately low referral rates. Photoscreening can be an appropriate technique for widespread vision screening of preschool children throughout the world.

Assessment of automated disease detection in diabetic retinopathy screening using two-field photography.

PubMed

Goatman, Keith; Charnley, Amanda; Webster, Laura; Nussey, Stephen

2011-01-01

To assess the performance of automated disease detection in diabetic retinopathy screening using two field mydriatic photography. Images from 8,271 sequential patient screening episodes from a South London diabetic retinopathy screening service were processed by the Medalytix iGrading™ automated grading system. For each screening episode macular-centred and disc-centred images of both eyes were acquired and independently graded according to the English national grading scheme. Where discrepancies were found between the automated result and original manual grade, internal and external arbitration was used to determine the final study grades. Two versions of the software were used: one that detected microaneurysms alone, and one that detected blot haemorrhages and exudates in addition to microaneurysms. Results for each version were calculated once using both fields and once using the macula-centred field alone. Of the 8,271 episodes, 346 (4.2%) were considered unassessable. Referable disease was detected in 587 episodes (7.1%). The sensitivity of the automated system for detecting unassessable images ranged from 97.4% to 99.1% depending on configuration. The sensitivity of the automated system for referable episodes ranged from 98.3% to 99.3%. All the episodes that included proliferative or pre-proliferative retinopathy were detected by the automated system regardless of configuration (192/192, 95% confidence interval 98.0% to 100%). If implemented as the first step in grading, the automated system would have reduced the manual grading effort by between 2,183 and 3,147 patient episodes (26.4% to 38.1%). Automated grading can safely reduce the workload of manual grading using two field, mydriatic photography in a routine screening service.

Color image generation for screen-scanning holographic display.

PubMed

Takaki, Yasuhiro; Matsumoto, Yuji; Nakajima, Tatsumi

2015-10-19

Horizontally scanning holography using a microelectromechanical system spatial light modulator (MEMS-SLM) can provide reconstructed images with an enlarged screen size and an increased viewing zone angle. Herein, we propose techniques to enable color image generation for a screen-scanning display system employing a single MEMS-SLM. Higher-order diffraction components generated by the MEMS-SLM for R, G, and B laser lights were coupled by providing proper illumination angles on the MEMS-SLM for each color. An error diffusion technique to binarize the hologram patterns was developed, in which the error diffusion directions were determined for each color. Color reconstructed images with a screen size of 6.2 in. and a viewing zone angle of 10.2° were generated at a frame rate of 30 Hz.

Flooding tolerance of soybean (Glycine max) germplasm from southeast Asia under field and screen-house environment

USDA-ARS?s Scientific Manuscript database

Soybean (Glycine max L. Merr.) cultivars from the U.S. are generally intolerant to flooding stress. Soybean germplasm and cultivars originating from other countries and grown in rotations with paddy rice potentially could have better flooding tolerance. Screen-house and field tests were conducted to...

A procedure to achieve fine control in MW processing of foods

NASA Astrophysics Data System (ADS)

Cuccurullo, G.; Cinquanta, L.; Sorrentino, G.

2007-01-01

A two-dimensional analytical model for predicting the unsteady temperature field in a cylindrical shaped body affected by spatially varying heat generation is presented. The dimensionless problem is solved analytically by using both partial solutions and the variation of parameters techniques. Having in mind industrial microwave heating for food pasteurization, the easy-to-handle solution is used to confirm the intrinsic lack of spatial uniformity of such a treatment in comparison to the traditional one. From an experimental point of view, a batch pasteurization treatment was realized to compare the effect of two different control techniques both based on IR thermography readout: the former assured a classical PID control, while the latter was based on a "shadowing" technique, consisting in covering portions of the sample which are hot enough with a mobile metallic screen. A measure of the effectiveness of the two control techniques was obtained by evaluating the thermal death curves of a strain Lactobacillus plantarum submitted to pasteurization temperatures. Preliminary results showed meaningful increases in the microwave thermal inactivation of the L. plantarum and similar significant decreases in thermal inactivation time with respect to the traditional pasteurization thermal treatment.

Dual-surface dielectric depth detector for holographic millimeter-wave security scanners

NASA Astrophysics Data System (ADS)

McMakin, Douglas L.; Keller, Paul E.; Sheen, David M.; Hall, Thomas E.

2009-05-01

The Transportation Security Administration (TSA) is presently deploying millimeter-wave whole body scanners at over 20 airports in the United States. Threats that may be concealed on a person are displayed to the security operator of this scanner. "Passenger privacy is ensured through the anonymity of the image. The officer attending the passenger cannot view the image, and the officer viewing the image is remotely located and cannot see the passenger. Additionally, the image cannot be stored, transmitted or printed and is deleted immediately after being viewed. Finally, the facial area of the image has been blurred to further ensure privacy." Pacific Northwest National Laboratory (PNNL) originated research into this novel security technology which has been independently commercialized by L-3 Communications, SafeView, Inc. PNNL continues to perform fundamental research into improved software techniques which are applicable to the field of holographic security screening technology. This includes performing significant research to remove human features from the imagery. Both physical and software imaging techniques have been employed. The physical imaging techniques include polarization diversity illumination and reception, dual frequency implementation, and high frequency imaging at 100 GHz. This paper will focus on a software privacy technique using a dual surface dielectric depth detector method.

Lens-free shadow image based high-throughput continuous cell monitoring technique.

PubMed

Jin, Geonsoo; Yoo, In-Hwa; Pack, Seung Pil; Yang, Ji-Woon; Ha, Un-Hwan; Paek, Se-Hwan; Seo, Sungkyu

2012-01-01

A high-throughput continuous cell monitoring technique which does not require any labeling reagents or destruction of the specimen is demonstrated. More than 6000 human alveolar epithelial A549 cells are monitored for up to 72 h simultaneously and continuously with a single digital image within a cost and space effective lens-free shadow imaging platform. In an experiment performed within a custom built incubator integrated with the lens-free shadow imaging platform, the cell nucleus division process could be successfully characterized by calculating the signal-to-noise ratios (SNRs) and the shadow diameters (SDs) of the cell shadow patterns. The versatile nature of this platform also enabled a single cell viability test followed by live cell counting. This study firstly shows that the lens-free shadow imaging technique can provide a continuous cell monitoring without any staining/labeling reagent and destruction of the specimen. This high-throughput continuous cell monitoring technique based on lens-free shadow imaging may be widely utilized as a compact, low-cost, and high-throughput cell monitoring tool in the fields of drug and food screening or cell proliferation and viability testing. Copyright © 2012 Elsevier B.V. All rights reserved.

High-speed spectral nanocytology for early cancer screening

PubMed Central

Subramanian, Hariharan; Maneval, Charles D.; White, Craig A.; Levenson, Richard M.; Backman, Vadim

2013-01-01

Abstract. High-throughput partial wave spectroscopy (HTPWS) is introduced as a high-speed spectral nanocytology technique that utilizes the field effect of carcinogenesis to perform minimally invasive cancer screening on at-risk populations. HTPWS uses fully automated hardware and an acousto-optic tunable filter to scan slides at low magnification, to select cells, and to rapidly acquire spectra at each spatial pixel in a cell between 450 and 700 nm, completing measurements of 30 cells in 40 min. Statistical quantitative analysis on the size and density of intracellular nanostructures extracted from the spectra at each pixel in a cell yields the diagnostic biomarker, disorder strength (Ld). Linear correlation between Ld and the length scale of nanostructures was measured in phantoms with R2=0.93. Diagnostic sensitivity was demonstrated by measuring significantly higher Ld from a human colon cancer cell line (HT29 control vector) than a less aggressive variant (epidermal growth factor receptor knockdown). Clinical diagnostic performance for lung cancer screening was tested on 23 patients, yielding a significant difference in Ld between smokers and cancer patients, p=0.02 and effect size=1.00. The high-throughput performance, nanoscale sensitivity, and diagnostic sensitivity make HTPWS a potentially clinically relevant modality for risk stratification of the large populations at risk of developing cancer. PMID:24193949

High throughput selection of novel plant growth regulators: Assessing the translatability of small bioactive molecules from Arabidopsis to crops.

PubMed

Rodriguez-Furlán, Cecilia; Miranda, Giovanna; Reggiardo, Martín; Hicks, Glenn R; Norambuena, Lorena

2016-04-01

Plant growth regulators (PGRs) have become an integral part of agricultural and horticultural practices. Accordingly, there is an increased demand for new and cost-effective products. Nevertheless, the market is limited by insufficient innovation. In this context chemical genomics has gained increasing attention as a powerful approach addressing specific traits. Here is described the successful implementation of a highly specific, sensitive and efficient high throughput screening approach using Arabidopsis as a model. Using a combination of techniques, 10,000 diverse compounds were screened and evaluated for several important plant growth traits including root and leaf growth. The phenotype-based selection allowed the compilation of a collection of putative Arabidopsis growth regulators with a broad range of activities and specificities. A subset was selected for evaluating their bioactivity in agronomically valuable plants. Their validation as growth regulators in commercial species such as tomato, lettuce, carrot, maize and turfgrasses reinforced the success of the screening in Arabidopsis and indicated that small molecules activity can be efficiently translated to commercial species. Therefore, the chemical genomics approach in Arabidopsis is a promising field that can be incorporated in PGR discovery programs and has a great potential to develop new products that can be efficiently used in crops. Copyright © 2016. Published by Elsevier Ireland Ltd.

Novel drug discovery for Chagas disease.

PubMed

Moraes, Carolina B; Franco, Caio H

2016-01-01

Chagas disease is a chronic infection associated with long-term morbidity. Increased funding and advocacy for drug discovery for neglected diseases have prompted the introduction of several important technological advances, and Chagas disease is among the neglected conditions that has mostly benefited from technological developments. A number of screening campaigns, and the development of new and improved in vitro and in vivo assays, has led to advances in the field of drug discovery. This review highlights the major advances in Chagas disease drug screening, and how these are being used not only to discover novel chemical entities and drug candidates, but also increase our knowledge about the disease and the parasite. Different methodologies used for compound screening and prioritization are discussed, as well as novel techniques for the investigation of these targets. The molecular mechanism of action is also discussed. Technological advances have been executed with scientific rigour for the development of new in vitro cell-based assays and in vivo animal models, to bring about novel and better drugs for Chagas disease, as well as to increase our understanding of what are the necessary properties for a compound to be successful in the clinic. The gained knowledge, combined with new exciting approaches toward target deconvolution, will help identifying new targets for Chagas disease chemotherapy in the future.

Screening applications in drug discovery based on microfluidic technology

PubMed Central

Eribol, P.; Uguz, A. K.; Ulgen, K. O.

2016-01-01

Microfluidics has been the focus of interest for the last two decades for all the advantages such as low chemical consumption, reduced analysis time, high throughput, better control of mass and heat transfer, downsizing a bench-top laboratory to a chip, i.e., lab-on-a-chip, and many others it has offered. Microfluidic technology quickly found applications in the pharmaceutical industry, which demands working with leading edge scientific and technological breakthroughs, as drug screening and commercialization are very long and expensive processes and require many tests due to unpredictable results. This review paper is on drug candidate screening methods with microfluidic technology and focuses specifically on fabrication techniques and materials for the microchip, types of flow such as continuous or discrete and their advantages, determination of kinetic parameters and their comparison with conventional systems, assessment of toxicities and cytotoxicities, concentration generations for high throughput, and the computational methods that were employed. An important conclusion of this review is that even though microfluidic technology has been in this field for around 20 years there is still room for research and development, as this cutting edge technology requires ingenuity to design and find solutions for each individual case. Recent extensions of these microsystems are microengineered organs-on-chips and organ arrays. PMID:26865904

Rapid screening of potential autophagic inductor agents using mammalian cell lines.

PubMed

Martins, Waleska K; Severino, Divinomar; Souza, Cleidiane; Stolf, Beatriz S; Baptista, Maurício S

2013-06-01

Recent progress in understanding the molecular basis of autophagy has demonstrated its importance in several areas of human health. Affordable screening techniques with higher sensitivity and specificity to identify autophagy are, however, needed to move the field forward. In fact, only laborious and/or expensive methodologies such as electron microscopy, dye-staining of autophagic vesicles, and LC3-II immunoblotting or immunoassaying are available for autophagy identification. Aiming to fulfill this technical gap, we describe here the association of three widely used assays to determine cell viability - Crystal Violet staining (CVS), 3-[4, 5-dimethylthiaolyl]-2, 5-diphenyl-tetrazolium bromide (MTT) reduction, and neutral red uptake (NRU) - to predict autophagic cell death in vitro. The conceptual framework of the method is the superior uptake of NR in cells engaging in autophagy. NRU was then weighted by the average of MTT reduction and CVS allowing the calculation of autophagic arbitrary units (AAU), a numeric variable that correlated specifically with the autophagic cell death. The proposed strategy is very useful for drug discovery, allowing the investigation of potential autophagic inductor agents through a rapid screening using mammalian cell lines B16-F10, HaCaT, HeLa, MES-SA, and MES-SA/Dx5 in a unique single microplate. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Photosensitive space charge limited current in screen printed CdTe thin films

NASA Astrophysics Data System (ADS)

Vyas, C. U.; Pataniya, Pratik; Zankat, Chetan K.; Patel, Alkesh B.; Pathak, V. M.; Patel, K. D.; Solanki, G. K.

2018-05-01

Group II-VI Compounds have emerged out as most suitable in the class of photo sensitive material. They represent a strong position in terms of their applications in the field of detectors as well as photo voltaic devices. Cadmium telluride is the prime member of this Group, because of high acceptance of this material as active component in opto-electronic devices. In this paper we report preparation and characterization of CdTe thin films by using a most economical screen printing technique in association with sintering at 510°C temperature. Surface morphology and smoothness are prime parameters of any deposited to be used as an active region of devices. Thus, we studied of the screen printed thin film by means of atomic force microscopy (AFM) and scanning electron microscopy (SEM) for this purpose. However, growth processes induced intrinsic defects in fabricated films work as charge traps and affect the conduction process significantly. So the conduction mechanism of deposited CdTe thin film is studied under dark as well as illuminated conditions. It is found that the deposited films showed the space charge limited conduction (SCLC) mechanism and hence various parameters of space charge limited conduction (SCLC) of CdTe film were evaluated and discussed and the photo responsive resistance is also presented in this paper.

Screening applications in drug discovery based on microfluidic technology.

PubMed

Eribol, P; Uguz, A K; Ulgen, K O

2016-01-01

Microfluidics has been the focus of interest for the last two decades for all the advantages such as low chemical consumption, reduced analysis time, high throughput, better control of mass and heat transfer, downsizing a bench-top laboratory to a chip, i.e., lab-on-a-chip, and many others it has offered. Microfluidic technology quickly found applications in the pharmaceutical industry, which demands working with leading edge scientific and technological breakthroughs, as drug screening and commercialization are very long and expensive processes and require many tests due to unpredictable results. This review paper is on drug candidate screening methods with microfluidic technology and focuses specifically on fabrication techniques and materials for the microchip, types of flow such as continuous or discrete and their advantages, determination of kinetic parameters and their comparison with conventional systems, assessment of toxicities and cytotoxicities, concentration generations for high throughput, and the computational methods that were employed. An important conclusion of this review is that even though microfluidic technology has been in this field for around 20 years there is still room for research and development, as this cutting edge technology requires ingenuity to design and find solutions for each individual case. Recent extensions of these microsystems are microengineered organs-on-chips and organ arrays.

Tuning the electronic properties of gated multilayer phosphorene: A self-consistent tight-binding study

NASA Astrophysics Data System (ADS)

Li, L. L.; Partoens, B.; Peeters, F. M.

2018-04-01

By taking account of the electric-field-induced charge screening, a self-consistent calculation within the framework of the tight-binding approach is employed to obtain the electronic band structure of gated multilayer phosphorene and the charge densities on the different phosphorene layers. We find charge density and screening anomalies in single-gated multilayer phosphorene and electron-hole bilayers in dual-gated multilayer phosphorene. Due to the unique puckered lattice structure, both intralayer and interlayer charge screenings are important in gated multilayer phosphorene. We find that the electric-field tuning of the band structure of multilayer phosphorene is distinctively different in the presence and absence of charge screening. For instance, it is shown that the unscreened band gap of multilayer phosphorene decreases dramatically with increasing electric-field strength. However, in the presence of charge screening, the magnitude of this band-gap decrease is significantly reduced and the reduction depends strongly on the number of phosphorene layers. Our theoretical results of the band-gap tuning are compared with recent experiments and good agreement is found.

The value of ultrasonography alone in screening surveys of cystic echinococcosis in children in Turkey.

PubMed

Kilimcioğlu, Ali A; Ozkol, Mine; Bayindir, Petek; Girginkardeşler, Nogay; Ostan, Ipek; Ok, Ulgen Z

2006-12-01

A total of 1,205 primary school children were examined for cystic echinococcosis in five villages of Manisa, Turkey, to evaluate the efficacy of diagnostic methods of this infection in community-based screening surveys. Six hundred and thirty children from three villages, examined by a portable ultrasound scanner, chest microfilm and serological methods (ELISA, indirect hemagglutination) in our previous study, were designated as Study Group 1; and 575 children, from two adjacent villages, examined by ultrasonography alone in the present study, were designated as Study Group 2. In Study Group 1, hepatic cystic echinococcosis was detected in two cases (0.3%) by ultrasonography, while 43 (8.9%) and 49 (10.1%) cases were found to be positive for cystic echinococcosis by ELISA and indirect hemagglutination, respectively. Three of 575 children (0.5%) were diagnosed with cystic echinococcosis (two hepatic and one renal involvement) by ultrasonography alone in Study Group 2; and lung lesions were later detected in both cases with liver involvement by chest radiography. Our results suggested that serological tests may be beneficial in suspected cases for confirmation and differential diagnosis, but have some drawbacks, such as discrepancy in results and high false seropositivity rates. Chest microfilm is not easy in field studies and exposure to X-ray is undesirable. As a reliable, simple, inexpensive and rapid technique, ultrasonography alone is recommended to be used in community-based screening surveys for cystic echinococcosis with confirmatory tests for suspected cases found during the screening program.

A high efficiency gene disruption strategy using a positive-negative split selection marker and electroporation for Fusarium oxysporum.

PubMed

Liang, Liqin; Li, Jianqiang; Cheng, Lin; Ling, Jian; Luo, Zhongqin; Bai, Miao; Xie, Bingyan

2014-11-01

The Fusarium oxysporum species complex consists of fungal pathogens that cause serial vascular wilt disease on more than 100 cultivated species throughout the world. Gene function analysis is rapidly becoming more and more important as the whole-genome sequences of various F. oxysporum strains are being completed. Gene-disruption techniques are a common molecular tool for studying gene function, yet are often a limiting step in gene function identification. In this study we have developed a F. oxysporum high-efficiency gene-disruption strategy based on split-marker homologous recombination cassettes with dual selection and electroporation transformation. The method was efficiently used to delete three RNA-dependent RNA polymerase (RdRP) genes. The gene-disruption cassettes of three genes can be constructed simultaneously within a short time using this technique. The optimal condition for electroporation is 10μF capacitance, 300Ω resistance, 4kV/cm field strength, with 1μg of DNA (gene-disruption cassettes). Under these optimal conditions, we were able to obtain 95 transformants per μg DNA. And after positive-negative selection, the transformants were efficiently screened by PCR, screening efficiency averaged 85%: 90% (RdRP1), 85% (RdRP2) and 77% (RdRP3). This gene-disruption strategy should pave the way for high throughout genetic analysis in F. oxysporum. Copyright © 2014 Elsevier GmbH. All rights reserved.

Periodic health examination, 1995 update: 1. Screening for human papillomavirus infection in asymptomatic women. Canadian Task Force on the Periodic Health Examination.

PubMed

Johnson, K

1995-02-15

To develop recommendations for practising physicians on the advisability of screening for human papillomavirus (HPV) infection in asymptomatic women. Visual inspection, Papanicolaou testing, colposcopy or cervicography, use of HPV group-specific antigen, DNA hybridization, dot blot technique, Southern blot technique or polymerase chain reaction followed by physical or chemical therapeutic intervention. Evidence for a link between HPV infection and cervical cancer, sensitivity and specificity of HPV screening techniques, effectiveness of treatments for HPV infection, and the social and economic costs incurred by screening. MEDLINE was searched for articles published between January 1966 to June 1993 with the use of the key words "papillomavirus," "cervix neoplasms," "mass screening," "prospective studies," "prevalence," "sensitivity," "specificity," "human" and "female." Proven cost-effective screening techniques that could lead to decreased morbidity or mortality were given a high value. The evidence-based methods and values of the Canadian Task Force on the Periodic Health Examination were used. Potential benefits are to prevent cervical cancer and eliminate HPV infection. Potential harmful effects include the creation of an unnecessary burden on the health care system and the labelling of otherwise healthy people as patients with a sexually transmitted disease for which therapy is generally ineffective. Potential costs would include expense of testing, increased use of colposcopy and treatment. There is fair evidence to exclude HPV screening (beyond Papanicolaou testing for cervical cancer) in asymptomatic women (grade D recommendation). The report was reviewed by members of the task force and three external reviewers who were selected to represent different areas of expertise. These guidelines were developed and endorsed by the task force, which is funded by Health Canada and the National Health Research and Development Program. The principal author (K.J.) was supported in part by the National Health Research and Development Program through a National Health Fellowship (AIDS).

Soil gas screening for chlorinated solvents at three contaminated karst sites in Tennessee

USGS Publications Warehouse

Wolfe, W.J.; Williams, S.D.

2002-01-01

Soil gas was sampled using active sampling techniques and passive collectors at three sites in Tennessee to evaluate the effectiveness of these techniques for locating chlorinated solvent sources and flowpaths in karst aquifers. Actively collected soil gas samples were analyzed in the field with a portable gas chromatograph, and the passive soil gas collectors were analyzed in the lab with gas chromatography/mass spectrometry. Results of the sampling indicate that the effectiveness of both techniques is highly dependent on the distribution of the contaminants in the subsurface, the geomorphic and hydrogeologic characteristics of the site, and, in one case, on seasonal conditions. Both active and passive techniques identified areas of elevated subsurface chlorinated solvent concentrations at a landfill site where contamination remains concentrated in the regolith. Neither technique detected chlorinated solvents known to be moving in the bedrock at a manufacturing site characterized by thick regolith and an absence of surficial karst features. Passive soil gas sampling had varied success detecting flowpaths for chloroform in the bedrock at a train derailment site characterized by shallow regolith and abundant surficial karst features. At the train derailment site, delineation of the contaminant flowpath through passive soil gas sampling was stronger and more detailed under Winter conditions than summer.

Distortion of DNA Origami on Graphene Imaged with Advanced TEM Techniques.

PubMed

Kabiri, Yoones; Ananth, Adithya N; van der Torre, Jaco; Katan, Allard; Hong, Jin-Yong; Malladi, Sairam; Kong, Jing; Zandbergen, Henny; Dekker, Cees

2017-08-01

While graphene may appear to be the ultimate support membrane for transmission electron microscopy (TEM) imaging of DNA nanostructures, very little is known if it poses an advantage over conventional carbon supports in terms of resolution and contrast. Microscopic investigations are carried out on DNA origami nanoplates that are supported onto freestanding graphene, using advanced TEM techniques, including a new dark-field technique that is recently developed in our lab. TEM images of stained and unstained DNA origami are presented with high contrast on both graphene and amorphous carbon membranes. On graphene, the images of the origami plates show severe unwanted distortions, where the rectangular shape of the nanoplates is significantly distorted. From a number of comparative control experiments, it is demonstrated that neither staining agents, nor screening ions, nor the level of electron-beam irradiation cause this distortion. Instead, it is suggested that origami nanoplates are distorted due to hydrophobic interaction of the DNA bases with graphene upon adsorption of the DNA origami nanoplates. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electromagnetic radiation screening of semiconductor devices for long life applications

NASA Technical Reports Server (NTRS)

Hall, T. C.; Brammer, W. G.

1972-01-01

A review is presented of the mechanism of interaction of electromagnetic radiation in various spectral ranges, with various semiconductor device defects. Previous work conducted in this area was analyzed as to its pertinence to the current problem. The task was studied of implementing electromagnetic screening methods in the wavelength region determined to be most effective. Both scanning and flooding type stimulation techniques are discussed. While the scanning technique offers a considerably higher yield of useful information, a preliminary investigation utilizing the flooding approach is first recommended because of the ease of implementation, lower cost and ability to provide go-no-go information in semiconductor screening.

Study of optical techniques for the Ames unitary wind tunnels. Part 2: Light sheet and vapor screen

NASA Technical Reports Server (NTRS)

Lee, George

1992-01-01

Light sheet and vapor screen methods have been studied with particular emphasis on those systems that have been used in large transonic and supersonic wind tunnels. The various fluids and solids used as tracers or light scatters and the methods for tracing generation have been studied. Light sources from high intensity lamps and various lasers have been surveyed. Light sheet generation and projection methods were considered. Detectors and location of detectors were briefly studied. A vapor screen system and a technique for location injection of tracers for the NASA Ames 9 by 7 foot Supersonic Wind Tunnel were proposed.

Screening for colorectal cancer.

PubMed

Ross, C C

1988-12-01

Efforts to decrease the number of deaths from colorectal cancer have focused on screening techniques, since no etiologic agent has been identified. Current screening regimens are designed to detect colorectal cancer in a large population in a cost-efficient manner and to minimize the risks associated with work-ups for false-positive tests. A two-part screening questionnaire for colorectal cancer helps identify patients who are at moderate risk for this cancer.

A new versatile microarray-based method for high throughput screening of carbohydrate-active enzymes.

PubMed

Vidal-Melgosa, Silvia; Pedersen, Henriette L; Schückel, Julia; Arnal, Grégory; Dumon, Claire; Amby, Daniel B; Monrad, Rune Nygaard; Westereng, Bjørge; Willats, William G T

2015-04-03

Carbohydrate-active enzymes have multiple biological roles and industrial applications. Advances in genome and transcriptome sequencing together with associated bioinformatics tools have identified vast numbers of putative carbohydrate-degrading and -modifying enzymes including glycoside hydrolases and lytic polysaccharide monooxygenases. However, there is a paucity of methods for rapidly screening the activities of these enzymes. By combining the multiplexing capacity of carbohydrate microarrays with the specificity of molecular probes, we have developed a sensitive, high throughput, and versatile semiquantitative enzyme screening technique that requires low amounts of enzyme and substrate. The method can be used to assess the activities of single enzymes, enzyme mixtures, and crude culture broths against single substrates, substrate mixtures, and biomass samples. Moreover, we show that the technique can be used to analyze both endo-acting and exo-acting glycoside hydrolases, polysaccharide lyases, carbohydrate esterases, and lytic polysaccharide monooxygenases. We demonstrate the potential of the technique by identifying the substrate specificities of purified uncharacterized enzymes and by screening enzyme activities from fungal culture broths. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Accelerated test techniques for micro-circuits: Evaluation of high temperature (473 k - 573 K) accelerated life test techniques as effective microcircuit screening methods

NASA Technical Reports Server (NTRS)

Johnson, G. M.

1976-01-01

The application of high temperature accelerated test techniques was shown to be an effective method of microcircuit defect screening. Comprehensive microcircuit evaluations and a series of high temperature (473 K to 573 K) life tests demonstrated that a freak or early failure population of surface contaminated devices could be completely screened in thirty two hours of test at an ambient temperature of 523 K. Equivalent screening at 398 K, as prescribed by current Military and NASA specifications, would have required in excess of 1,500 hours of test. All testing was accomplished with a Texas Instruments' 54L10, low power triple-3 input NAND gate manufactured with a titanium- tungsten (Ti-W), Gold (Au) metallization system. A number of design and/or manufacturing anomalies were also noted with the Ti-W, Au metallization system. Further study of the exact nature and cause(s) of these anomalies is recommended prior to the use of microcircuits with Ti-W, Au metallization in long life/high reliability applications. Photomicrographs of tested circuits are included.

One Question, Multiple Answers: Biochemical and Biophysical Screening Methods Retrieve Deviating Fragment Hit Lists.

PubMed

Schiebel, Johannes; Radeva, Nedyalka; Köster, Helene; Metz, Alexander; Krotzky, Timo; Kuhnert, Maren; Diederich, Wibke E; Heine, Andreas; Neumann, Lars; Atmanene, Cedric; Roecklin, Dominique; Vivat-Hannah, Valérie; Renaud, Jean-Paul; Meinecke, Robert; Schlinck, Nina; Sitte, Astrid; Popp, Franziska; Zeeb, Markus; Klebe, Gerhard

2015-09-01

Fragment-based lead discovery is gaining momentum in drug development. Typically, a hierarchical cascade of several screening techniques is consulted to identify fragment hits which are then analyzed by crystallography. Because crystal structures with bound fragments are essential for the subsequent hit-to-lead-to-drug optimization, the screening process should distinguish reliably between binders and non-binders. We therefore investigated whether different screening methods would reveal similar collections of putative binders. First we used a biochemical assay to identify fragments that bind to endothiapepsin, a surrogate for disease-relevant aspartic proteases. In a comprehensive screening approach, we then evaluated our 361-entry library by using a reporter-displacement assay, saturation-transfer difference NMR, native mass spectrometry, thermophoresis, and a thermal shift assay. While the combined results of these screening methods retrieve 10 of the 11 crystal structures originally predicted by the biochemical assay, the mutual overlap of individual hit lists is surprisingly low, highlighting that each technique operates on different biophysical principles and conditions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Research and Development of Hazardous/Toxic Waste Analytical Screening Procedures. Available Field Methods for Rapid Screening of Hazardous Waste Materials at Waste Sites (Class A Poisons).

DTIC Science & Technology

1982-01-01

bromide is listed as a positive interference. Nitric oxide and nitrogen dioxide can be detected by using the Draeger nitrous fumes detector tube. A... fumes exhibit a delay from the time of exposure to the onset of symptoms. This time delay would not be conducive for a rapid field screening test. It...Dangerous when strongly heated, emits highly toxic fumes . THRESHOLD LIMIT VALUE: No information available PHYSIOLOGICAL EFFECTS: A. Intensely irritating to

Impurity screening behavior of the high-field side scrape-off layer in near-double-null configurations: prospect for mitigating plasma-material interactions on RF actuators and first-wall components

NASA Astrophysics Data System (ADS)

LaBombard, B.; Kuang, A. Q.; Brunner, D.; Faust, I.; Mumgaard, R.; Reinke, M. L.; Terry, J. L.; Howard, N.; Hughes, J. W.; Chilenski, M.; Lin, Y.; Marmar, E.; Rice, J. E.; Rodriguez-Fernandez, P.; Wallace, G.; Whyte, D. G.; Wolfe, S.; Wukitch, S.

2017-07-01

The impurity screening response of the high-field side (HFS) scrape-off layer (SOL) to localized nitrogen injection is investigated on Alcator C-Mod for magnetic equilibria spanning lower-single-null, double-null and upper-single-null configurations under otherwise identical plasma conditions. L-mode, EDA H-mode and I-mode discharges are investigated. HFS impurity screening is found to depend on magnetic flux balance and the direction of B  ×  \

Velocity Vector Field Visualization of Flow in Liquid Acquisition Device Channel

NASA Technical Reports Server (NTRS)

McQuillen, John B.; Chao, David F.; Hall, Nancy R.; Zhang, Nengli

2012-01-01

A capillary flow liquid acquisition device (LAD) for cryogenic propellants has been developed and tested in NASA Glenn Research Center to meet the requirements of transferring cryogenic liquid propellants from storage tanks to an engine in reduced gravity environments. The prototypical mesh screen channel LAD was fabricated with a mesh screen, covering a rectangular flow channel with a cylindrical outlet tube, and was tested with liquid oxygen (LOX). In order to better understand the performance in various gravity environments and orientations at different liquid submersion depths of the screen channel LAD, a series of computational fluid dynamics (CFD) simulations of LOX flow through the LAD screen channel was undertaken. The resulting velocity vector field visualization for the flow in the channel has been used to reveal the gravity effects on the flow in the screen channel.

Handheld and mobile hyperspectral imaging sensors for wide-area standoff detection of explosives and chemical warfare agents

NASA Astrophysics Data System (ADS)

Gomer, Nathaniel R.; Gardner, Charles W.; Nelson, Matthew P.

2016-05-01

Hyperspectral imaging (HSI) is a valuable tool for the investigation and analysis of targets in complex background with a high degree of autonomy. HSI is beneficial for the detection of threat materials on environmental surfaces, where the concentration of the target of interest is often very low and is typically found within complex scenery. Two HSI techniques that have proven to be valuable are Raman and shortwave infrared (SWIR) HSI. Unfortunately, current generation HSI systems have numerous size, weight, and power (SWaP) limitations that make their potential integration onto a handheld or field portable platform difficult. The systems that are field-portable do so by sacrificing system performance, typically by providing an inefficient area search rate, requiring close proximity to the target for screening, and/or eliminating the potential to conduct real-time measurements. To address these shortcomings, ChemImage Sensor Systems (CISS) is developing a variety of wide-field hyperspectral imaging systems. Raman HSI sensors are being developed to overcome two obstacles present in standard Raman detection systems: slow area search rate (due to small laser spot sizes) and lack of eye-safety. SWIR HSI sensors have been integrated into mobile, robot based platforms and handheld variants for the detection of explosives and chemical warfare agents (CWAs). In addition, the fusion of these two technologies into a single system has shown the feasibility of using both techniques concurrently to provide higher probability of detection and lower false alarm rates. This paper will provide background on Raman and SWIR HSI, discuss the applications for these techniques, and provide an overview of novel CISS HSI sensors focused on sensor design and detection results.

Physics-based scoring of protein-ligand interactions: explicit polarizability, quantum mechanics and free energies.

PubMed

Bryce, Richard A

2011-04-01

The ability to accurately predict the interaction of a ligand with its receptor is a key limitation in computer-aided drug design approaches such as virtual screening and de novo design. In this article, we examine current strategies for a physics-based approach to scoring of protein-ligand affinity, as well as outlining recent developments in force fields and quantum chemical techniques. We also consider advances in the development and application of simulation-based free energy methods to study protein-ligand interactions. Fuelled by recent advances in computational algorithms and hardware, there is the opportunity for increased integration of physics-based scoring approaches at earlier stages in computationally guided drug discovery. Specifically, we envisage increased use of implicit solvent models and simulation-based scoring methods as tools for computing the affinities of large virtual ligand libraries. Approaches based on end point simulations and reference potentials allow the application of more advanced potential energy functions to prediction of protein-ligand binding affinities. Comprehensive evaluation of polarizable force fields and quantum mechanical (QM)/molecular mechanical and QM methods in scoring of protein-ligand interactions is required, particularly in their ability to address challenging targets such as metalloproteins and other proteins that make highly polar interactions. Finally, we anticipate increasingly quantitative free energy perturbation and thermodynamic integration methods that are practical for optimization of hits obtained from screened ligand libraries.

The Vainshtein mechanism in the cosmic web

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falck, Bridget; Koyama, Kazuya; Zhao, Gong-bo

We investigate the dependence of the Vainshtein screening mechanism on the cosmic web morphology of both dark matter particles and halos as determined by ORIGAMI. Unlike chameleon and symmetron screening, which come into effect in regions of high density, Vainshtein screening instead depends on the dimensionality of the system, and screened bodies can still feel external fields. ORIGAMI is well-suited to this problem because it defines morphologies according to the dimensionality of the collapsing structure and does not depend on a smoothing scale or density threshold parameter. We find that halo particles are screened while filament, wall, and void particlesmore » are unscreened, and this is independent of the particle density. However, after separating halos according to their large scale cosmic web environment, we find no difference in the screening properties of halos in filaments versus halos in clusters. We find that the fifth force enhancement of dark matter particles in halos is greatest well outside the virial radius. We confirm the theoretical expectation that even if the internal field is suppressed by the Vainshtein mechanism, the object still feels the fifth force generated by the external fields, by measuring peculiar velocities and velocity dispersions of halos. Finally, we investigate the morphology and gravity model dependence of halo spins, concentrations, and shapes.« less

Analytical techniques for steroid estrogens in water samples - A review.

PubMed

Fang, Ting Yien; Praveena, Sarva Mangala; deBurbure, Claire; Aris, Ahmad Zaharin; Ismail, Sharifah Norkhadijah Syed; Rasdi, Irniza

2016-12-01

In recent years, environmental concerns over ultra-trace levels of steroid estrogens concentrations in water samples have increased because of their adverse effects on human and animal life. Special attention to the analytical techniques used to quantify steroid estrogens in water samples is therefore increasingly important. The objective of this review was to present an overview of both instrumental and non-instrumental analytical techniques available for the determination of steroid estrogens in water samples, evidencing their respective potential advantages and limitations using the Need, Approach, Benefit, and Competition (NABC) approach. The analytical techniques highlighted in this review were instrumental and non-instrumental analytical techniques namely gas chromatography mass spectrometry (GC-MS), liquid chromatography mass spectrometry (LC-MS), enzyme-linked immuno sorbent assay (ELISA), radio immuno assay (RIA), yeast estrogen screen (YES) assay, and human breast cancer cell line proliferation (E-screen) assay. The complexity of water samples and their low estrogenic concentrations necessitates the use of highly sensitive instrumental analytical techniques (GC-MS and LC-MS) and non-instrumental analytical techniques (ELISA, RIA, YES assay and E-screen assay) to quantify steroid estrogens. Both instrumental and non-instrumental analytical techniques have their own advantages and limitations. However, the non-instrumental ELISA analytical techniques, thanks to its lower detection limit and simplicity, its rapidity and cost-effectiveness, currently appears to be the most reliable for determining steroid estrogens in water samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electrostatic correlations in inhomogeneous charged fluids beyond loop expansion

NASA Astrophysics Data System (ADS)

Buyukdagli, Sahin; Achim, C. V.; Ala-Nissila, T.

2012-09-01

Electrostatic correlation effects in inhomogeneous symmetric electrolytes are investigated within a previously developed electrostatic self-consistent theory [R. R. Netz and H. Orland, Eur. Phys. J. E 11, 301 (2003)], 10.1140/epje/i2002-10159-0. To this aim, we introduce two computational approaches that allow to solve the self-consistent equations beyond the loop expansion. The first method is based on a perturbative Green's function technique, and the second one is an extension of a previously introduced semiclassical approximation for single dielectric interfaces to the case of slit nanopores. Both approaches can handle the case of dielectrically discontinuous boundaries where the one-loop theory is known to fail. By comparing the theoretical results obtained from these schemes with the results of the Monte Carlo simulations that we ran for ions at neutral single dielectric interfaces, we first show that the weak coupling Debye-Huckel theory remains quantitatively accurate up to the bulk ion density ρb ≃ 0.01 M, whereas the self-consistent theory exhibits a good quantitative accuracy up to ρb ≃ 0.2 M, thus improving the accuracy of the Debye-Huckel theory by one order of magnitude in ionic strength. Furthermore, we compare the predictions of the self-consistent theory with previous Monte Carlo simulation data for charged dielectric interfaces and show that the proposed approaches can also accurately handle the correlation effects induced by the surface charge in a parameter regime where the mean-field result significantly deviates from the Monte Carlo data. Then, we derive from the perturbative self-consistent scheme the one-loop theory of asymmetrically partitioned salt systems around a dielectrically homogeneous charged surface. It is shown that correlation effects originate in these systems from a competition between the salt screening loss at the interface driving the ions to the bulk region, and the interfacial counterion screening excess attracting them towards the surface. This competition can be quantified in terms of the characteristic surface charge σ _s^*=√{2ρ _b/(π ℓ _B)}, where ℓB = 7 Å is the Bjerrum length. In the case of weak surface charges σ _s≪ σ _s^* where counterions form a diffuse layer, the interfacial salt screening loss is the dominant effect. As a result, correlation effects decrease the mean-field density of both coions and counterions. With an increase of the surface charge towards σ _s^*, the surface-attractive counterion screening excess starts to dominate, and correlation effects amplify in this regime the mean-field density of both type of ions. However, in the regime σ _s>σ _s^*, the same counterion screening excess also results in a significant decrease of the electrostatic mean-field potential. This reduces in turn the mean-field counterion density far from the charged surface. We also show that for σ _s≫ σ _s^*, electrostatic correlations result in a charge inversion effect. However, the electrostatic coupling regime where this phenomenon takes place should be verified with Monte Carlo simulations since this parameter regime is located beyond the validity range of the one-loop theory.

Electrostatic correlations in inhomogeneous charged fluids beyond loop expansion.

PubMed

Buyukdagli, Sahin; Achim, C V; Ala-Nissila, T

2012-09-14

Electrostatic correlation effects in inhomogeneous symmetric electrolytes are investigated within a previously developed electrostatic self-consistent theory [R. R. Netz and H. Orland, Eur. Phys. J. E 11, 301 (2003)]. To this aim, we introduce two computational approaches that allow to solve the self-consistent equations beyond the loop expansion. The first method is based on a perturbative Green's function technique, and the second one is an extension of a previously introduced semiclassical approximation for single dielectric interfaces to the case of slit nanopores. Both approaches can handle the case of dielectrically discontinuous boundaries where the one-loop theory is known to fail. By comparing the theoretical results obtained from these schemes with the results of the Monte Carlo simulations that we ran for ions at neutral single dielectric interfaces, we first show that the weak coupling Debye-Huckel theory remains quantitatively accurate up to the bulk ion density ρ(b) ≃ 0.01 M, whereas the self-consistent theory exhibits a good quantitative accuracy up to ρ(b) ≃ 0.2 M, thus improving the accuracy of the Debye-Huckel theory by one order of magnitude in ionic strength. Furthermore, we compare the predictions of the self-consistent theory with previous Monte Carlo simulation data for charged dielectric interfaces and show that the proposed approaches can also accurately handle the correlation effects induced by the surface charge in a parameter regime where the mean-field result significantly deviates from the Monte Carlo data. Then, we derive from the perturbative self-consistent scheme the one-loop theory of asymmetrically partitioned salt systems around a dielectrically homogeneous charged surface. It is shown that correlation effects originate in these systems from a competition between the salt screening loss at the interface driving the ions to the bulk region, and the interfacial counterion screening excess attracting them towards the surface. This competition can be quantified in terms of the characteristic surface charge σ(s)*=√(2ρ(b)/(πl(B)), where l(B) = 7 Å is the Bjerrum length. In the case of weak surface charges σ(s)≪σ(s)* where counterions form a diffuse layer, the interfacial salt screening loss is the dominant effect. As a result, correlation effects decrease the mean-field density of both coions and counterions. With an increase of the surface charge towards σ(s)*, the surface-attractive counterion screening excess starts to dominate, and correlation effects amplify in this regime the mean-field density of both type of ions. However, in the regime σ(s)>σ(s)*, the same counterion screening excess also results in a significant decrease of the electrostatic mean-field potential. This reduces in turn the mean-field counterion density far from the charged surface. We also show that for σ(s)≫σ(s)*, electrostatic correlations result in a charge inversion effect. However, the electrostatic coupling regime where this phenomenon takes place should be verified with Monte Carlo simulations since this parameter regime is located beyond the validity range of the one-loop theory.

Prevention of Blindness: Chronic Glaucoma

ERIC Educational Resources Information Center

Richardson, Kenneth T.

1970-01-01

An evaluation of present screening procedures for chronic open-angle glaucoma includes suggestions for improvement: greater distribution of screening and education, conversion from monophasic to multiphasic screen, and examination of visual fields, optic nerve, and medical history in addition to the tonometry currently done. (KW)

Role of re-screening of cervical smears in internal quality control.

PubMed Central

Baker, A; Melcher, D; Smith, R

1995-01-01

AIMS--To investigate the use of rapid re-screening as a quality control method for previously screened cervical slides; to compare this method with 10% random re-screening and clinically indicated double screening. METHODS--Between June 1990 and December 1994, 117,890 negative smears were subjected to rapid re-screening. RESULTS--This study shows that rapid re-screening detects far greater numbers of false negative cases when compared with both 10% random re-screening and clinically indicated double screening, with no additional demand on human resources. The technique also identifies variation in the performance of screening personnel as an additional benefit. CONCLUSION--Rapid re-screening is an effective method of quality control. Although less sensitive, rapid re-screening should replace 10% random re-screening and selected re-screening as greater numbers of false negative results are detected while consuming less resources. PMID:8543619

'Enzyme Test Bench': A biochemical application of the multi-rate modeling

NASA Astrophysics Data System (ADS)

Rachinskiy, K.; Schultze, H.; Boy, M.; Büchs, J.

2008-11-01

In the expanding field of 'white biotechnology' enzymes are frequently applied to catalyze the biochemical reaction from a resource material to a valuable product. Evolutionary designed to catalyze the metabolism in any life form, they selectively accelerate complex reactions under physiological conditions. Modern techniques, such as directed evolution, have been developed to satisfy the increasing demand on enzymes. Applying these techniques together with rational protein design, we aim at improving of enzymes' activity, selectivity and stability. To tap the full potential of these techniques, it is essential to combine them with adequate screening methods. Nowadays a great number of high throughput colorimetric and fluorescent enzyme assays are applied to measure the initial enzyme activity with high throughput. However, the prediction of enzyme long term stability within short experiments is still a challenge. A new high throughput technique for enzyme characterization with specific attention to the long term stability, called 'Enzyme Test Bench', is presented. The concept of the Enzyme Test Bench consists of short term enzyme tests conducted under partly extreme conditions to predict the enzyme long term stability under moderate conditions. The technique is based on the mathematical modeling of temperature dependent enzyme activation and deactivation. Adapting the temperature profiles in sequential experiments by optimum non-linear experimental design, the long term deactivation effects can be purposefully accelerated and detected within hours. During the experiment the enzyme activity is measured online to estimate the model parameters from the obtained data. Thus, the enzyme activity and long term stability can be calculated as a function of temperature. The results of the characterization, based on micro liter format experiments of hours, are in good agreement with the results of long term experiments in 1L format. Thus, the new technique allows for both: the enzyme screening with regard to the long term stability and the choice of the optimal process temperature. The presented article gives a successful example for the application of multi-rate modeling, experimental design and parameter estimation within biochemical engineering. At the same time, it shows the limitations of the methods at the state of the art and addresses the current problems to the applied mathematics community.

Comprehensive Urine Drug Screen by Gas Chromatography/Mass Spectrometry (GC/MS).

PubMed

Ramoo, Bheemraj; Funke, Melissa; Frazee, Clint; Garg, Uttam

2016-01-01

Drug screening is an essential component of clinical toxicology laboratory service. Some laboratories use only automated chemistry analyzers for limited screening of drugs of abuse and few other drugs. Other laboratories use a combination of various techniques such as immunoassays, colorimetric tests, and mass spectrometry to provide more detailed comprehensive drug screening. Mass spectrometry, gas or liquid, can screen for hundreds of drugs and is often considered the gold standard for comprehensive drug screening. We describe an efficient and rapid gas chromatography/mass spectrometry (GC/MS) method for comprehensive drug screening in urine which utilizes a liquid-liquid extraction, sample concentration, and analysis by GC/MS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frerichs, H.; Reiter, D.; Schmitz, O.

The impact of resonant magnetic perturbations (RMPs) on the plasma edge can be analyzed in detail by three dimensional computer simulations, which take the underlying magnetic field structure as input. Previously, the 'vacuum approximation' has been used to calculate the magnetic field structure although plasma response effects may result in a screening (or even an amplification) of the external perturbations. Simulation results for an ITER similar shape plasma at the DIII-D tokamak are presented for the full vacuum perturbation field and an ad hoc screening case in comparison to the unperturbed configuration. It is shown that the RMP induced helicalmore » patterns in the plasma edge and on the divertor target shrink once screening is taken into account. However, a flat temperature profile is still found in the 'open field line domain' inside the separatrix, while the 'density pump out effect' found in the vacuum RMP case is considerably weakened.« less

Screening of polar components of petroleum products by electrospray ionization mass spectrometry

USGS Publications Warehouse

Rostad, Colleen E.

2005-01-01

The polar components of fuels may enable differentiation between fuel types or commercial fuel sources. Screening for these components in the hydrocarbon product is difficult due to their very low concentrations in such a complex matrix. Various commercial fuels from several sources were analyzed by flow injection analysis/electrospray ionization/mass spectrometry without extensive sample preparation, separation, or chromatography. This technique enabled screening for unique polar components at very low concentrations in commercial hydrocarbon products. This analysis was then applied to hydrocarbon samples collected from the subsurface with a different extent of biodegradation or weathering. Although the alkane and isoprenoid portion had begun to biodegrade or weather, the polar components had changed little over time. Because these polar compounds are unique in different fuels, this screening technique can provide source information on hydrocarbons released into the environment.

Biophotonic endoscopy: a review of clinical research techniques for optical imaging and sensing of early gastrointestinal cancer

PubMed Central

Coda, Sergio; Siersema, Peter D.; Stamp, Gordon W. H.; Thillainayagam, Andrew V.

2015-01-01

Detection, characterization, and staging constitute the fundamental elements in the endoscopic diagnosis of gastrointestinal diseases, but histology still remains the diagnostic gold standard. New developments in endoscopic techniques may challenge histopathology in the near future. An ideal endoscopic technique should combine a wide-field, “red flag” screening technique with an optical contrast or microscopy method for characterization and staging, all simultaneously available during the procedure. In theory, biophotonic advances have the potential to unite these elements to allow in vivo “optical biopsy.” These techniques may ultimately offer the potential to increase the rates of detection of high risk lesions and the ability to target biopsies and resections, and so reduce the need for biopsy, costs, and uncertainty for patients. However, their utility and sensitivity in clinical practice must be evaluated against those of conventional histopathology. This review describes some of the most recent applications of biophotonics in endoscopic optical imaging and metrology, along with their fundamental principles and the clinical experience that has been acquired in their deployment as tools for the endoscopist. Particular emphasis has been placed on translational label-free optical techniques, such as fluorescence spectroscopy, fluorescence lifetime imaging microscopy (FLIM), two-photon and multi-photon microscopy, second harmonic generation (SHG) and third harmonic generation (THG) imaging, optical coherence tomography (OCT), diffuse reflectance, Raman spectroscopy, and molecular imaging. PMID:26528489

3D visualization techniques for the STEREO-mission

NASA Astrophysics Data System (ADS)

Wiegelmann, T.; Podlipnik, B.; Inhester, B.; Feng, L.; Ruan, P.

The forthcoming STEREO-mission will observe the Sun from two different viewpoints We expect about 2GB data per day which ask for suitable data presentation techniques A key feature of STEREO is that it will provide for the first time a 3D-view of the Sun and the solar corona In our normal environment we see objects three dimensional because the light from real 3D objects needs different travel times to our left and right eye As a consequence we see slightly different images with our eyes which gives us information about the depth of objects and a corresponding 3D impression Techniques for the 3D-visualization of scientific and other data on paper TV computer screen cinema etc are well known e g two colour anaglyph technique shutter glasses polarization filters and head-mounted displays We discuss advantages and disadvantages of these techniques and how they can be applied to STEREO-data The 3D-visualization techniques are not limited to visual images but can be also used to show the reconstructed coronal magnetic field and energy and helicity distribution In the advent of STEREO we test the method with data from SOHO which provides us different viewpoints by the solar rotation This restricts the analysis to structures which remain stationary for several days Real STEREO-data will not be affected by these limitations however

Standardization of Analysis Sets for Reporting Results from ADNI MRI Data

PubMed Central

Wyman, Bradley T.; Harvey, Danielle J.; Crawford, Karen; Bernstein, Matt A.; Carmichael, Owen; Cole, Patricia E.; Crane, Paul; DeCarli, Charles; Fox, Nick C.; Gunter, Jeffrey L.; Hill, Derek; Killiany, Ronald J.; Pachai, Chahin; Schwarz, Adam J.; Schuff, Norbert; Senjem, Matthew L.; Suhy, Joyce; Thompson, Paul M.; Weiner, Michael; Jack, Clifford R.

2013-01-01

The ADNI 3D T1-weighted MRI acquisitions provide a rich dataset for developing and testing analysis techniques for extracting structural endpoints. To promote greater rigor in analysis and meaningful comparison of different algorithms, the ADNI MRI Core has created standardized analysis sets of data comprising scans that met minimum quality control requirements. We encourage researchers to test and report their techniques against these data. Standard analysis sets of volumetric scans from ADNI-1 have been created, comprising: screening visits, 1 year completers (subjects who all have screening, 6 and 12 month scans), two year annual completers (screening, 1, and 2 year scans), two year completers (screening, 6 months, 1 year, 18 months (MCI only) and 2 years) and complete visits (screening, 6 months, 1 year, 18 months (MCI only), 2, and 3 year (normal and MCI only) scans). As the ADNI-GO/ADNI-2 data becomes available, updated standard analysis sets will be posted regularly. PMID:23110865

Teaching strategies to facilitate breast cancer screening by African-American women.

PubMed

Gibson, Lynette M

2008-12-01

The objective of this paper is to report on the recent literature concerning coverage of breast cancer epidemiology, the barriers to breast cancer screening, and the strategies to facilitate screening by African-American women. Based on these findings, the author suggests culturally appropriate techniques to be used to promote breast cancer screening in African-American women. Barriers to breast cancer screening in African-American women include emotional reasons, spiritual/religious reasons, fatalism, logistic concerns, lack of knowledge, and lack of follow-up by health-care professionals. Numerous strategies that have been targeted toward African-American women are reported. These include storytelling, witnessing, and testimonies; providing social support and having social support networks; and conducting multifaceted programs that include culturally specific breast health information. Based on the literature reviewed, the author suggests some examples of creative and culturally appropriate techniques that have been implemented with African-American women and that have resulted in positive feedback. These examples include the use of testimonies, photographs, prose, narratives, poetry, and quotations.

Adipose-derived mesenchymal stem cells and regenerative medicine.

PubMed

Konno, Masamitsu; Hamabe, Atsushi; Hasegawa, Shinichiro; Ogawa, Hisataka; Fukusumi, Takahito; Nishikawa, Shimpei; Ohta, Katsuya; Kano, Yoshihiro; Ozaki, Miyuki; Noguchi, Yuko; Sakai, Daisuke; Kudoh, Toshihiro; Kawamoto, Koichi; Eguchi, Hidetoshi; Satoh, Taroh; Tanemura, Masahiro; Nagano, Hiroaki; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

2013-04-01

Adipose tissue-derived mesenchymal stem cells (ADSCs) are multipotent and can differentiate into various cell types, including osteocytes, adipocytes, neural cells, vascular endothelial cells, cardiomyocytes, pancreatic β-cells, and hepatocytes. Compared with the extraction of other stem cells such as bone marrow-derived mesenchymal stem cells (BMSCs), that of ADSCs requires minimally invasive techniques. In the field of regenerative medicine, the use of autologous cells is preferable to embryonic stem cells or induced pluripotent stem cells. Therefore, ADSCs are a useful resource for drug screening and regenerative medicine. Here we present the methods and mechanisms underlying the induction of multilineage cells from ADSCs. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

Faradaic AC Electrokinetic Flow and Particle Traps

NASA Astrophysics Data System (ADS)

Ben, Yuxing; Chang, Hsueh-Chia

2004-11-01

Faradaic reaction at higher voltages can produce co-ion polarization at AC electrodes instead of counter-ion polarization due to capacitive charging from the bulk. The Faradaic co-ion polarization also does not screen the external field and hence can produce large net electro-kinetic flows at frequencies lower than the inverse RC time of the double layer. Due to the opposite polarization of capacitve and Faradaic charging, we can reverse the direction of AC flows on electrodes by changing the voltage and frequency. Particles and bacteria are trapped and then dispersed at stagnation lines, at locations predicted by our theory, by using these two flows sequentially. This technique offers a good way to concentrate and detect bacteria.

Football injuries: current concepts.

PubMed

Olson, David E; Sikka, Robby Singh; Hamilton, Abigail; Krohn, Austin

2011-01-01

Football is one of the most popular sports in the United States and is the leading cause of sports-related injury. A large focus in recent years has been on concussions, sudden cardiac death, and heat illness, all thought to be largely preventable health issues in the young athlete. Injury prevention through better understanding of injury mechanisms, education, proper equipment, and practice techniques and preseason screening may aid in reducing the number of injuries. Proper management of on-field injuries and health emergencies can reduce the morbidity associated with these injuries and may lead to faster return to play and reduced risk of future injury. This article reviews current concepts surrounding frequently seen football-related injuries.

Screening spectroscopy of prostate cancer

NASA Astrophysics Data System (ADS)

Yermolenko, S. B.; Voloshynskyy, D. I.; Fedoruk, O. S.

2015-11-01

The aim of the study was to establish objective parameters of the field of laser and incoherent radiation of different spectral ranges (UV, visible, IR) as a non-invasive optical method of interaction with different samples of biological tissues and fluids of patients to determine the state of prostate cancer and choosing the best personal treatment. The objects of study were selected venous blood plasma of patient with prostate cancer, histological sections of rat prostate gland in the postoperative period. As diagnostic methods have been used ultraviolet spectrometry samples of blood plasma in the liquid state, infrared spectroscopy middle range (2,5-25 microns) dry residue of plasma by spectral diagnostic technique of thin histological sections of biological tissues.

Moving Raman spectroscopy into real-time, online diagnosis and detection of precancer and cancer in vivo in the upper GI during clinical endoscopic examination

NASA Astrophysics Data System (ADS)

Huang, Zhiwei; Bergholt, Mads Sylvest; Zheng, Wei; Ho, Khek Yu; Yeoh, Khay Guan; Teh, Ming; So, Jimmy Bok Yan; Shabbir, Asim

2013-03-01

A rapid image-guided Raman endoscopy system integrated with on-line diagnostic scheme is developed for in vivo Raman tissue diagnosis (optical biopsy) in the upper GI during clinical gastrointestinal endoscopy under multimodal wide-field imaging guidance. The real-time Raman endoscopy technique was tested prospectively on new gastric patients (n=4) and could identify dysplasia in vivo with sensitivity of 81.5% (22/27) and specificity of 87.9% (29/33). This study realizes for the first time the novel image-guided Raman endoscopy as a screening tool for real-time, online diagnosis of gastric cancer and precancer in vivo at endoscopy.

Screen Space Ambient Occlusion Based Multiple Importance Sampling for Real-Time Rendering

NASA Astrophysics Data System (ADS)

Zerari, Abd El Mouméne; Babahenini, Mohamed Chaouki

2018-03-01

We propose a new approximation technique for accelerating the Global Illumination algorithm for real-time rendering. The proposed approach is based on the Screen-Space Ambient Occlusion (SSAO) method, which approximates the global illumination for large, fully dynamic scenes at interactive frame rates. Current algorithms that are based on the SSAO method suffer from difficulties due to the large number of samples that are required. In this paper, we propose an improvement to the SSAO technique by integrating it with a Multiple Importance Sampling technique that combines a stratified sampling method with an importance sampling method, with the objective of reducing the number of samples. Experimental evaluation demonstrates that our technique can produce high-quality images in real time and is significantly faster than traditional techniques.

Hard-X-ray dark-field imaging using a grating interferometer.

PubMed

Pfeiffer, F; Bech, M; Bunk, O; Kraft, P; Eikenberry, E F; Brönnimann, Ch; Grünzweig, C; David, C

2008-02-01

Imaging with visible light today uses numerous contrast mechanisms, including bright- and dark-field contrast, phase-contrast schemes and confocal and fluorescence-based methods. X-ray imaging, on the other hand, has only recently seen the development of an analogous variety of contrast modalities. Although X-ray phase-contrast imaging could successfully be implemented at a relatively early stage with several techniques, dark-field imaging, or more generally scattering-based imaging, with hard X-rays and good signal-to-noise ratio, in practice still remains a challenging task even at highly brilliant synchrotron sources. In this letter, we report a new approach on the basis of a grating interferometer that can efficiently yield dark-field scatter images of high quality, even with conventional X-ray tube sources. Because the image contrast is formed through the mechanism of small-angle scattering, it provides complementary and otherwise inaccessible structural information about the specimen at the micrometre and submicrometre length scale. Our approach is fully compatible with conventional transmission radiography and a recently developed hard-X-ray phase-contrast imaging scheme. Applications to X-ray medical imaging, industrial non-destructive testing and security screening are discussed.

Log-rise of the resistivity in the holographic Kondo model

NASA Astrophysics Data System (ADS)

Padhi, Bikash; Tiwari, Apoorv; Setty, Chandan; Phillips, Philip W.

2018-03-01

We study a single-channel Kondo effect using a recently developed [1-4] holographic large-N technique. In order to obtain resistivity of this model, we introduce a probe field. The gravity dual of a localized fermionic impurity in 1 +1 -dimensional host matter is constructed by embedding a localized two-dimensional Anti-de Sitter (AdS2 )-brane in the bulk of three-dimensional AdS3 . This helps us construct an impurity charge density which acts as a source to the bulk equation of motion of the probe gauge field. The functional form of the charge density is obtained independently by solving the equations of motion for the fields confined to the AdS2 -brane. The asymptotic solution of the probe field is dictated by the impurity charge density, which in turn affects the current-current correlation functions and hence the resistivity. Our choice of parameters tunes the near-boundary impurity current to be marginal, resulting in a log T behavior in the UV resistivity, as is expected for the Kondo problem. The resistivity at the IR fixed point turns out to be zero, signaling a complete screening of the impurity.

Screening and treatments using telemedicine in retinopathy of prematurity

PubMed Central

Thanos, Aristomenis; Yonekawa, Yoshihiro; Todorich, Bozho; Moshfeghi, Darius M; Trese, Michael T

2016-01-01

Several studies have validated the role of telemedicine as a new powerful screening and diagnostic tool for retinal disorders, such as diabetic retinopathy and retinopathy of prematurity. With regard to retinopathy of prematurity, bedside examination with binocular indirect ophthalmoscopy has been the gold standard technique for screening, yet with several limitations. Herein, we review the current evidence that supports the role of telemedicine for the screening of infants with retinopathy of prematurity. PMID:28539810

How to benchmark methods for structure-based virtual screening of large compound libraries.

PubMed

Christofferson, Andrew J; Huang, Niu

2012-01-01

Structure-based virtual screening is a useful computational technique for ligand discovery. To systematically evaluate different docking approaches, it is important to have a consistent benchmarking protocol that is both relevant and unbiased. Here, we describe the designing of a benchmarking data set for docking screen assessment, a standard docking screening process, and the analysis and presentation of the enrichment of annotated ligands among a background decoy database.

Aspergillus antibody detection: diagnostic strategy and technical considerations from the Société Française de Mycologie Médicale (French Society for Medical Mycology) expert committee.

PubMed

Persat, F; Hennequin, C; Gangneux, J P

2017-04-01

Until now, there has been no consensus on the best method for the detection of anti-Aspergillus antibodies, a key diagnostic tool for chronic aspergilloses. To better appreciate the usage of and confidence in these techniques, the Société Française de Mycologie Médicale (French Society for Medical Mycology; SFMM) performed a two-step survey of French experts. First, we administered an initial survey to French labs performing Aspergillus serology to depict usage of the different techniques available for Aspergillus serology. Second, an opinion poll was conducted of 40 experts via an online questionnaire. Each item was rated from 1 to 9 according to the level of agreement. The initial survey revealed that enzyme-linked immunosorbent assay (ELISA) (81%) and immunoelectrophoresis (IEP) (67%) were the most commonly used techniques for screening and confirmation, respectively. The distinction between screening and confirmation techniques was confirmed by the experts (median = 7) with a 44.2% variation coefficient. Only ELISA for screening and IEP and Western blot (WB) for confirmation were clearly considered valuable methods (median ≥8 with variation coefficients less than 30%). The use of a confirmation technique was recommended in the case of a positive result in a compatible clinical context (cystic fibrosis, for example) or during the patient's follow-up. In the case of discordant results between the screening and confirmation techniques, the experts recommended greater confidence in the results obtained with the confirmation technique. All experts emphasized the need to standardize Aspergillus serology techniques and to better define the place of each of them in the diagnosis of aspergillosis. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Biorefinery of the macroalgae Ulva lactuca: extraction of proteins and carbohydrates by mild disintegration.

PubMed

Postma, P R; Cerezo-Chinarro, O; Akkerman, R J; Olivieri, G; Wijffels, R H; Brandenburg, W A; Eppink, M H M

2018-01-01

The effect of osmotic shock, enzymatic incubation, pulsed electric field, and high shear homogenization on the release of water-soluble proteins and carbohydrates from the green alga Ulva lactuca was investigated in this screening study. For osmotic shock, both temperature and incubation time had a significant influence on the release with an optimum at 30 °C for 24 h of incubation. For enzymatic incubation, pectinase demonstrated being the most promising enzyme for both protein and carbohydrate release. Pulsed electric field treatment was most optimal at an electric field strength of 7.5 kV cm -1 with 0.05 ms pulses and a specific energy input relative to the released protein as low as 6.6 kWh kg prot -1 . Regarding literature, this study reported the highest protein (~ 39%) and carbohydrate (~ 51%) yields of the four technologies using high shear homogenization. Additionally, an energy reduction up to 86% was achieved by applying a novel two-phase (macrostructure size reduction and cell disintegration) technique.

Senate Concurrent Resolution 83: Screening for Learning Disabilities. A Report to the 70th Legislature.

ERIC Educational Resources Information Center

Texas Education Agency, Austin.

In response to Senate Concurrent Resolution 83, the Texas Education Agency studied methods for screening all students upon entry to school for significant developmental lags that could lead to learning disabilities. The resulting report includes: (1) identification of screening techniques; (2) methods currently in use and validated for treatment…

A simplified high-throughput method for pyrethroid knock-down resistance (kdr) detection in Anopheles gambiae

PubMed Central

Lynd, Amy; Ranson, Hilary; McCall, P J; Randle, Nadine P; Black, William C; Walker, Edward D; Donnelly, Martin J

2005-01-01

Background A single base pair mutation in the sodium channel confers knock-down resistance to pyrethroids in many insect species. Its occurrence in Anopheles mosquitoes may have important implications for malaria vector control especially considering the current trend for large scale pyrethroid-treated bednet programmes. Screening Anopheles gambiae populations for the kdr mutation has become one of the mainstays of programmes that monitor the development of insecticide resistance. The screening is commonly performed using a multiplex Polymerase Chain Reaction (PCR) which, since it is reliant on a single nucleotide polymorphism, can be unreliable. Here we present a reliable and potentially high throughput method for screening An. gambiae for the kdr mutation. Methods A Hot Ligation Oligonucleotide Assay (HOLA) was developed to detect both the East and West African kdr alleles in the homozygous and heterozygous states, and was optimized for use in low-tech developing world laboratories. Results from the HOLA were compared to results from the multiplex PCR for field and laboratory mosquito specimens to provide verification of the robustness and sensitivity of the technique. Results and Discussion The HOLA assay, developed for detection of the kdr mutation, gives a bright blue colouration for a positive result whilst negative reactions remain colourless. The results are apparent within a few minutes of adding the final substrate and can be scored by eye. Heterozygotes are scored when a sample gives a positive reaction to the susceptible probe and the kdr probe. The technique uses only basic laboratory equipment and skills and can be carried out by anyone familiar with the Enzyme-linked immunosorbent assay (ELISA) technique. A comparison to the multiplex PCR method showed that the HOLA assay was more reliable, and scoring of the plates was less ambiguous. Conclusion The method is capable of detecting both the East and West African kdr alleles in the homozygous and heterozygous states from fresh or dried material using several DNA extraction methods. It is more reliable than the traditional PCR method and may be more sensitive for the detection of heterozygotes. It is inexpensive, simple and relatively safe making it suitable for use in resource-poor countries. PMID:15766386

Safe housing ensured by an electric field screen that excludes insect-net permeating haematophagous mosquitoes carrying human pathogens

NASA Astrophysics Data System (ADS)

Matsuda, Y.; Kakutani, K.; Nonomura, T.; Kimbara, J.; Osamura, K.; Kusakar, S.; Toyoda, H.

2015-10-01

An electric field screen can be used to keep mosquitoes out of houses with open windows. In this study, doubly charged dipolar electric field screens (DD-screens) were used to capture mosquitoes entering through a window. The screen had two components: three layers of insulated conductor iron wires (ICWs) in parallel arrays and two electrostatic direct current (DC) voltage generators that supplied negative or positive voltages to the ICWs. Within each layer, the ICWs were parallel at 5-mm intervals, and connected to each other and to a negative or positive voltage generator. The negatively and positively charged ICWs are represented as ICW(-) and ICW(+), respectively. The screen consisted of one ICW(+) layer with an ICW(-) layer on either side. The Asian tiger mosquito (Aedes albopictus) and house mosquito (Culex pipiens) were used as models of vectors carrying viral pathogens. Adult mosquitoes were blown into the space between the ICWs by sending compressed air through the tip of an insect aspirator to determine the voltage range that captured all of the test insects. Wind speed was measured at the surface of the ICW using a sensitive anemometer. The result showed that at ≥ 1.2 kV, the force was strong enough that the ICWs captured all of the mosquitoes, despite a wind speed of 7 m/s. Therefore, the DD-screen could serve as a physical barrier to prevent noxious mosquitoes from entering houses with good air penetration.

Computer Simulation of Breast Cancer Screening

DTIC Science & Technology

1999-07-01

techniques for evaluating the screening efficacy of mammography. Breast cancer growth rates, incidence rates, multiracial population demographics, death ... rates , breast cancer prognosis factors, breast density considerations, detection versus diameter probabilities, and other pertinent data have been

Extended Field Laser Confocal Microscopy (EFLCM): Combining automated Gigapixel image capture with in silico virtual microscopy

PubMed Central

Flaberg, Emilie; Sabelström, Per; Strandh, Christer; Szekely, Laszlo

2008-01-01

Background Confocal laser scanning microscopy has revolutionized cell biology. However, the technique has major limitations in speed and sensitivity due to the fact that a single laser beam scans the sample, allowing only a few microseconds signal collection for each pixel. This limitation has been overcome by the introduction of parallel beam illumination techniques in combination with cold CCD camera based image capture. Methods Using the combination of microlens enhanced Nipkow spinning disc confocal illumination together with fully automated image capture and large scale in silico image processing we have developed a system allowing the acquisition, presentation and analysis of maximum resolution confocal panorama images of several Gigapixel size. We call the method Extended Field Laser Confocal Microscopy (EFLCM). Results We show using the EFLCM technique that it is possible to create a continuous confocal multi-colour mosaic from thousands of individually captured images. EFLCM can digitize and analyze histological slides, sections of entire rodent organ and full size embryos. It can also record hundreds of thousands cultured cells at multiple wavelength in single event or time-lapse fashion on fixed slides, in live cell imaging chambers or microtiter plates. Conclusion The observer independent image capture of EFLCM allows quantitative measurements of fluorescence intensities and morphological parameters on a large number of cells. EFLCM therefore bridges the gap between the mainly illustrative fluorescence microscopy and purely quantitative flow cytometry. EFLCM can also be used as high content analysis (HCA) instrument for automated screening processes. PMID:18627634

Extended Field Laser Confocal Microscopy (EFLCM): combining automated Gigapixel image capture with in silico virtual microscopy.

PubMed

Flaberg, Emilie; Sabelström, Per; Strandh, Christer; Szekely, Laszlo

2008-07-16

Confocal laser scanning microscopy has revolutionized cell biology. However, the technique has major limitations in speed and sensitivity due to the fact that a single laser beam scans the sample, allowing only a few microseconds signal collection for each pixel. This limitation has been overcome by the introduction of parallel beam illumination techniques in combination with cold CCD camera based image capture. Using the combination of microlens enhanced Nipkow spinning disc confocal illumination together with fully automated image capture and large scale in silico image processing we have developed a system allowing the acquisition, presentation and analysis of maximum resolution confocal panorama images of several Gigapixel size. We call the method Extended Field Laser Confocal Microscopy (EFLCM). We show using the EFLCM technique that it is possible to create a continuous confocal multi-colour mosaic from thousands of individually captured images. EFLCM can digitize and analyze histological slides, sections of entire rodent organ and full size embryos. It can also record hundreds of thousands cultured cells at multiple wavelength in single event or time-lapse fashion on fixed slides, in live cell imaging chambers or microtiter plates. The observer independent image capture of EFLCM allows quantitative measurements of fluorescence intensities and morphological parameters on a large number of cells. EFLCM therefore bridges the gap between the mainly illustrative fluorescence microscopy and purely quantitative flow cytometry. EFLCM can also be used as high content analysis (HCA) instrument for automated screening processes.

Laboratory Screening and Field Bioassays of Insecticides for Controlling the Balsam Woolly Adelgid in Southen Appalachia

Treesearch

F.L. Hastings; P.J. Barry; I.R. Ragenovich

1979-01-01

Two concentrations of 13 insecticides and 3 fatty acids were screened in the laboratory against the balsam woolly adelgid (Adelges piceae (Ratz.)). Efficacy was judged on the percentage of dead adults and the number of living crawlers 24 hours after application. The top candidate materials, including lindane, were field bioassayed. Permethrin (Pounce or Ambush),...

Orbitals for classical arbitrary anisotropic colloidal potentials

NASA Astrophysics Data System (ADS)

Girard, Martin; Nguyen, Trung Dac; de la Cruz, Monica Olvera

2017-11-01

Coarse-grained potentials are ubiquitous in mesoscale simulations. While various methods to compute effective interactions for spherically symmetric particles exist, anisotropic interactions are seldom used, due to their complexity. Here we describe a general formulation, based on a spatial decomposition of the density fields around the particles, akin to atomic orbitals. We show that anisotropic potentials can be efficiently computed in numerical simulations using Fourier-based methods. We validate the field formulation and characterize its computational efficiency with a system of colloids that have Gaussian surface charge distributions. We also investigate the phase behavior of charged Janus colloids immersed in screened media, with screening lengths comparable to the colloid size. The system shows rich behaviors, exhibiting vapor, liquid, gel, and crystalline morphologies, depending on temperature and screening length. The crystalline phase only appears for symmetric Janus particles. For very short screening lengths, the system undergoes a direct transition from a vapor to a crystal on cooling; while, for longer screening lengths, a vapor-liquid-crystal transition is observed. The proposed formulation can be extended to model force fields that are time or orientation dependent, such as those in systems of polymer-grafted particles and magnetic colloids.

Detection beyond the Debye screening length in a high-frequency nanoelectronic biosensor.

PubMed

Kulkarni, Girish S; Zhong, Zhaohui

2012-02-08

Nanosensors based on the unique electronic properties of nanotubes and nanowires offer high sensitivity and have the potential to revolutionize the field of Point-of-Care (POC) medical diagnosis. The direct current (dc) detection of a wide array of organic and inorganic molecules has been demonstrated on these devices. However, sensing mechanism based on measuring changes in dc conductance fails at high background salt concentrations, where the sensitivity of the devices suffers from the ionic screening due to mobile ions present in the solution. Here, we successfully demonstrate that the fundamental ionic screening effect can be mitigated by operating single-walled carbon nanotube field effect transistor as a high-frequency biosensor. The nonlinear mixing between the alternating current excitation field and the molecular dipole field can generate mixing current sensitive to the surface-bound biomolecules. Electrical detection of monolayer streptavidin binding to biotin in 100 mM buffer solution is achieved at a frequency beyond 1 MHz. Theoretical modeling confirms improved sensitivity at high frequency through mitigation of the ionic screening effect. The results should promise a new biosensing platform for POC detection, where biosensors functioning directly in physiologically relevant condition are desired. © 2012 American Chemical Society

The Peru Cervical Cancer Screening Study (PERCAPS): The Design and Implementation of a Mother/Daughter Screen, Treat, and Vaccinate Program in the Peruvian Jungle

PubMed Central

Levinson, Kimberly L.; Salmeron, Jorge; Sologuren, Carlos Vallejos; Fernandez, Maria Jose Vallejos; Belinson, Jerome L.

2014-01-01

Peru struggles to prevent cervical cancer (CC). In the jungle, prevention programs suffer from significant barriers although technology exists to detect CC precursors. This study used community based participatory research (CBPR) methods to overcome barriers. The objective was to evaluate the utility of CBPR techniques in a mother–child screen/treat and vaccinate program for CC prevention in the Peruvian jungle. The CC prevention program used self-sampling for human papillomavirus (HPV) for screening, cryotherapy for treatment and the HPV vaccine Gardasil for vaccination. Community health leaders (HL) from around Iquitos participated in a two half day educational course. The HLs then decided how to implement interventions in their villages or urban sectors. The success of the program was measured by: (1) ability of the HLs to determine an implementation plan, (2) proper use of research forms, (3) participation and retention rates, and (4) participants’ satisfaction. HLs successfully registered 320 women at soup kitchens, schools, and health posts. Screening, treatment, and vaccination were successfully carried out using forms for registration, consent, and results with minimum error. In the screen/treat intervention 100 % of participants gave an HPV sample and 99.7 % reported high satisfaction; 81 % of HPV + women were treated, and 57 % returned for 6-month followup. Vaccine intervention: 98 % of girls received the 1st vaccine, 88 % of those received the 2nd, and 65 % the 3rd. CBPR techniques successfully helped implement a screen/treat and vaccinate CC prevention program around Iquitos, Peru. These techniques may be appropriate for large-scale preventive health-care interventions. PMID:24276617

The Peru Cervical Cancer Screening Study (PERCAPS): the design and implementation of a mother/daughter screen, treat, and vaccinate program in the Peruvian jungle.

PubMed

Abuelo, Carolina E; Levinson, Kimberly L; Salmeron, Jorge; Sologuren, Carlos Vallejos; Fernandez, Maria Jose Vallejos; Belinson, Jerome L

2014-06-01

Peru struggles to prevent cervical cancer (CC). In the jungle, prevention programs suffer from significant barriers although technology exists to detect CC precursors. This study used community based participatory research (CBPR) methods to overcome barriers. The objective was to evaluate the utility of CBPR techniques in a mother-child screen/treat and vaccinate program for CC prevention in the Peruvian jungle. The CC prevention program used self-sampling for human papillomavirus (HPV) for screening, cryotherapy for treatment and the HPV vaccine Gardasil for vaccination. Community health leaders (HL) from around Iquitos participated in a two half day educational course. The HLs then decided how to implement interventions in their villages or urban sectors. The success of the program was measured by: (1) ability of the HLs to determine an implementation plan, (2) proper use of research forms, (3) participation and retention rates, and (4) participants' satisfaction. HLs successfully registered 320 women at soup kitchens, schools, and health posts. Screening, treatment, and vaccination were successfully carried out using forms for registration, consent, and results with minimum error. In the screen/treat intervention 100% of participants gave an HPV sample and 99.7% reported high satisfaction; 81% of HPV + women were treated, and 57% returned for 6-month followup. Vaccine intervention: 98% of girls received the 1st vaccine, 88% of those received the 2nd, and 65% the 3rd. CBPR techniques successfully helped implement a screen/treat and vaccinate CC prevention program around Iquitos, Peru. These techniques may be appropriate for large-scale preventive health-care interventions.

Laser-Induced Fluorescence Detection in High-Throughput Screening of Heterogeneous Catalysts and Single Cells Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Hui

2001-01-01

Laser-induced fluorescence detection is one of the most sensitive detection techniques and it has found enormous applications in various areas. The purpose of this research was to develop detection approaches based on laser-induced fluorescence detection in two different areas, heterogeneous catalysts screening and single cell study. First, the author introduced laser-induced imaging (LIFI) as a high-throughput screening technique for heterogeneous catalysts to explore the use of this high-throughput screening technique in discovery and study of various heterogeneous catalyst systems. This scheme is based on the fact that the creation or the destruction of chemical bonds alters the fluorescence properties ofmore » suitably designed molecules. By irradiating the region immediately above the catalytic surface with a laser, the fluorescence intensity of a selected product or reactant can be imaged by a charge-coupled device (CCD) camera to follow the catalytic activity as a function of time and space. By screening the catalytic activity of vanadium pentoxide catalysts in oxidation of naphthalene, they demonstrated LIFI has good detection performance and the spatial and temporal resolution needed for high-throughput screening of heterogeneous catalysts. The sample packing density can reach up to 250 x 250 subunits/cm 2 for 40-μm wells. This experimental set-up also can screen solid catalysts via near infrared thermography detection. In the second part of this dissertation, the author used laser-induced native fluorescence coupled with capillary electrophoresis (LINF-CE) and microscope imaging to study the single cell degranulation. On the basis of good temporal correlation with events observed through an optical microscope, they have identified individual peaks in the fluorescence electropherograms as serotonin released from the granular core on contact with the surrounding fluid.« less

Clinical evaluation and use of urine screening for drug abuse.

PubMed Central

Saxon, A J; Calsyn, D A; Haver, V M; Delaney, C J

1988-01-01

Urine drug screening is indicated to evaluate patients who show mental status or behavioral changes and to monitor the abstinence of drug abusers. The appropriate timing for collecting urine specimens may vary depending on the suspected drug of abuse and on laboratory factors. Laboratories use a variety of techniques to do urine screens, and these must be understood by clinicians ordering the screens to interpret results correctly. In treating drug-abusing patients, clinicians must apply structured reinforcement in conjunction with urine screen results to aid patients in achieving abstinence. PMID:3176489

21 CFR 886.1810 - Tangent screen (campimeter).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tangent screen (campimeter). 886.1810 Section 886.1810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... a patient's visual field. This generic type of device includes projection tangent screens, target...

21 CFR 886.1810 - Tangent screen (campimeter).

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Identification. A tangent screen (campimeter) is an AC-powered or battery-powered device that is a large square... a patient's visual field. This generic type of device includes projection tangent screens, target... (general controls). The AC-powered device and the battery-powered device are exempt from the premarket...

21 CFR 886.1810 - Tangent screen (campimeter).

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Identification. A tangent screen (campimeter) is an AC-powered or battery-powered device that is a large square... a patient's visual field. This generic type of device includes projection tangent screens, target... (general controls). The AC-powered device and the battery-powered device are exempt from the premarket...

21 CFR 886.1810 - Tangent screen (campimeter).

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Identification. A tangent screen (campimeter) is an AC-powered or battery-powered device that is a large square... a patient's visual field. This generic type of device includes projection tangent screens, target... (general controls). The AC-powered device and the battery-powered device are exempt from the premarket...

21 CFR 886.1810 - Tangent screen (campimeter).

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Identification. A tangent screen (campimeter) is an AC-powered or battery-powered device that is a large square... a patient's visual field. This generic type of device includes projection tangent screens, target... (general controls). The AC-powered device and the battery-powered device are exempt from the premarket...

Coeliac disease screening is suboptimal in a tertiary gastroenterology setting.

PubMed

Iskandar, Heba; Gray, Darrell M; Vu, Hongha; Mirza, Faiz; Rude, Mary Katherine; Regan, Kara; Abdalla, Adil; Gaddam, Srinivas; Almaskeen, Sami; Mello, Michael; Marquez, Evelyn; Meyer, Claire; Bolkhir, Ahmed; Kanuri, Navya; Sayuk, Gregory; Gyawali, C Prakash

2017-08-01

Coeliac disease (CD) is widely prevalent in North America, but case-finding techniques currently used may not be adequate for patient identification. We aimed to determine the adequacy of CD screening in an academic gastroenterology (GI) practice. Consecutive initial visits to a tertiary academic GI practice were surveyed over a 3-month period as a fellow-initiated quality improvement project. All electronic records were reviewed to look for indications for CD screening according to published guidelines. The timing of screening was noted (before or after referral), as well as the screening method (serology or biopsy). Data were analysed to compare CD screening practices across subspecialty clinics. 616 consecutive patients (49±0.6 years, range 16-87 years, 58.5% females, 94% Caucasian) fulfilled inclusion criteria. CD testing was indicated in 336 (54.5%), but performed in only 145 (43.2%). The need for CD screening was highest in luminal GI and inflammatory bowel disease clinics, followed by biliary and hepatology clinics (p<0.0001); CD screening rate was highest in the luminal GI clinic (p=0.002). Of 145 patients screened, 4 patients (2.4%) had serology consistent with CD, of which 2 were proven by duodenal biopsy. Using this proportion, an additional 5 patients might have been diagnosed in 191 untested patients with indications for CD screening. More than 50% of patients in a tertiary GI clinic have indications for CD screening, but <50% of indicated cases are screened. Case-finding techniques therefore are suboptimal, constituting a gap in patient care and an important target for future quality improvement initiatives. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A screen-printed flexible flow sensor

NASA Astrophysics Data System (ADS)

Moschos, A.; Syrovy, T.; Syrova, L.; Kaltsas, G.

2017-04-01

A thermal flow sensor was printed on a flexible plastic substrate using exclusively screen-printing techniques. The presented device was implemented with custom made screen-printed thermistors, which allows simple, cost-efficient production on a variety of flexible substrates while maintaining the typical advantages of thermal flow sensors. Evaluation was performed for both static (zero flow) and dynamic conditions using a combination of electrical measurements and IR imaging techniques in order to determine important characteristics, such as temperature response, output repeatability, etc. The flow sensor was characterized utilizing the hot-wire and calorimetric principles of operation, while the preliminary results appear to be very promising, since the sensor was successfully evaluated and displayed adequate sensitivity in a relatively wide flow range.

A rapid method for hydraulic profiling in unconsolidated formations

USGS Publications Warehouse

Dietrich, P.; Butler, J.J.; Faiss, K.

2008-01-01

Information on vertical variations in hydraulic conductivity (K) can often shed much light on how a contaminant will move in the subsurface. The direct-push injection logger has been developed to rapidly obtain such information in shallow unconsolidated settings. This small-diameter tool consists of a short screen located just behind a drive point. The tool is advanced into the subsurface while water is injected through the screen to keep it clear. Upon reaching a depth at which information about K is desired, advancement ceases and the injection rate and pressure are measured on the land surface. The rate and pressure values are used in a ratio that serves as a proxy for K. A vertical profile of this ratio can be transformed into a K profile through regressions with K estimates determined using other techniques. The viability of the approach was assessed at an extensively studied field site in eastern Germany. The assessment demonstrated that this tool can rapidly identify zones that may serve as conduits for or barriers to contaminant movement. ?? 2007 The Author(s).

Mass detection in digital breast tomosynthesis data using convolutional neural networks and multiple instance learning.

PubMed

Yousefi, Mina; Krzyżak, Adam; Suen, Ching Y

2018-05-01

Digital breast tomosynthesis (DBT) was developed in the field of breast cancer screening as a new tomographic technique to minimize the limitations of conventional digital mammography breast screening methods. A computer-aided detection (CAD) framework for mass detection in DBT has been developed and is described in this paper. The proposed framework operates on a set of two-dimensional (2D) slices. With plane-to-plane analysis on corresponding 2D slices from each DBT, it automatically learns complex patterns of 2D slices through a deep convolutional neural network (DCNN). It then applies multiple instance learning (MIL) with a randomized trees approach to classify DBT images based on extracted information from 2D slices. This CAD framework was developed and evaluated using 5040 2D image slices derived from 87 DBT volumes. The empirical results demonstrate that this proposed CAD framework achieves much better performance than CAD systems that use hand-crafted features and deep cardinality-restricted Bolzmann machines to detect masses in DBTs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fragment-Based Docking: Development of the CHARMMing Web User Interface as a Platform for Computer-Aided Drug Design

PubMed Central

2015-01-01

Web-based user interfaces to scientific applications are important tools that allow researchers to utilize a broad range of software packages with just an Internet connection and a browser.1 One such interface, CHARMMing (CHARMM interface and graphics), facilitates access to the powerful and widely used molecular software package CHARMM. CHARMMing incorporates tasks such as molecular structure analysis, dynamics, multiscale modeling, and other techniques commonly used by computational life scientists. We have extended CHARMMing’s capabilities to include a fragment-based docking protocol that allows users to perform molecular docking and virtual screening calculations either directly via the CHARMMing Web server or on computing resources using the self-contained job scripts generated via the Web interface. The docking protocol was evaluated by performing a series of “re-dockings” with direct comparison to top commercial docking software. Results of this evaluation showed that CHARMMing’s docking implementation is comparable to many widely used software packages and validates the use of the new CHARMM generalized force field for docking and virtual screening. PMID:25151852

Fragment-based docking: development of the CHARMMing Web user interface as a platform for computer-aided drug design.

PubMed

Pevzner, Yuri; Frugier, Emilie; Schalk, Vinushka; Caflisch, Amedeo; Woodcock, H Lee

2014-09-22

Web-based user interfaces to scientific applications are important tools that allow researchers to utilize a broad range of software packages with just an Internet connection and a browser. One such interface, CHARMMing (CHARMM interface and graphics), facilitates access to the powerful and widely used molecular software package CHARMM. CHARMMing incorporates tasks such as molecular structure analysis, dynamics, multiscale modeling, and other techniques commonly used by computational life scientists. We have extended CHARMMing's capabilities to include a fragment-based docking protocol that allows users to perform molecular docking and virtual screening calculations either directly via the CHARMMing Web server or on computing resources using the self-contained job scripts generated via the Web interface. The docking protocol was evaluated by performing a series of "re-dockings" with direct comparison to top commercial docking software. Results of this evaluation showed that CHARMMing's docking implementation is comparable to many widely used software packages and validates the use of the new CHARMM generalized force field for docking and virtual screening.

Engineering a vitamin B12 high-throughput screening system by riboswitch sensor in Sinorhizobium meliloti.

PubMed

Cai, Yingying; Xia, Miaomiao; Dong, Huina; Qian, Yuan; Zhang, Tongcun; Zhu, Beiwei; Wu, Jinchuan; Zhang, Dawei

2018-05-11

As a very important coenzyme in the cell metabolism, Vitamin B 12 (cobalamin, VB 12 ) has been widely used in food and medicine fields. The complete biosynthesis of VB 12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB 12 production. High-yield VB 12 -producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. By the help of engineered strains with varied capacities of VB 12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5-2 was obtained and considered as a candidate for industrial applications. After 7 d's cultivation on a rotary shaker at 30 °C, the VB 12 titer of S. meliloti MC5-2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5-2 was sequenced, and gene mutations were identified and analyzed. To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB 12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB 12 -yield strains.

Experience factors in performing periodic physical evaluations

NASA Technical Reports Server (NTRS)

Hoffman, A. A.

1969-01-01

The lack of scientific basis in the so-called periodic health examinations on military personnel inclusive of the Executive Health Program is outlined. This latter program can well represent a management tool of the company involved in addition to being a status symbol. A multiphasic screening technique is proposed in conjunction with an automated medical history questionnaire for preventive occupational medicine methodology. The need to collate early sickness consultation or clinic visit histories with screening techniques is emphasized.

Techniques for analyzing frequency selective surfaces - A review

NASA Technical Reports Server (NTRS)

Mittra, Raj; Chan, Chi H.; Cwik, Tom

1988-01-01

A number of representative techniques for analyzing frequency-selective surfaces (FSSs), which comprise periodic arrays of patches or apertures in a conducting screen and find important applications as filters in microwaves and optics, are discussed. The basic properties of the FSSs are reviewed and several different approaches to predicting their frequency-response characteristics are described. Some recent developments in the treatment of truncated, curved, and doubly periodic screens are mentioned and representative experimental results are included.

[New intensifying screens in clinical radiology. II. Examinations in clinical practice].

PubMed

Freyschmidt, J; Saure, D; Hagemann, G

1976-09-01

A clinically applicable procedure for testing new intensifying rare earth screens, as well as the special Siemens' screen is described. The results are related to universal screens. The film-screen combination alpha 4XD (gadolinium oxysulphide with normal, green sensitive film) results in a reduction of radiation dose to half with detail comparable with universal screens. The Siemens' special screen has similar advantages. Screens with a higher intensification factor and reduction of the mAs to one sixth results in loss of detail. This does not necessarily reduce their clinical use if they are used for appropriate purposes. The results of this clinically orientated technique agreed well with physically objective methods using lead grids. The advantages of the new screens are discussed in terms of their practical application.

Web usability evaluation with screen reader users: implementation of the partial concurrent thinking aloud technique.

PubMed

Federici, Stefano; Stefano, Federici; Borsci, Simone; Stamerra, Gianluca

2010-08-01

A verbal protocol technique, adopted for a web usability evaluation, requires that the users are able to perform a double task: surfing and talking. Nevertheless, when blind users surf by using a screen reader and talk about the way they interact with the computer, the evaluation is influenced by a structural interference: users are forced to think aloud and listen to the screen reader at the same time. The aim of this study is to build up a verbal protocol technique for samples of visual impaired users in order to overcome the limits of concurrent and retrospective protocols. The technique we improved, called partial concurrent thinking aloud (PCTA), integrates a modified set of concurrent verbalization and retrospective analysis. One group of 6 blind users and another group of 6 sighted users evaluated the usability of a website using PCTA. By estimating the number of necessary users by the means of an asymptotic test, it was found out that the two groups had an equivalent ability of identifying usability problems, both over 80%. The result suggests that PCTA, while respecting the properties of classic verbal protocols, also allows to overcome the structural interference and the limits of concurrent and retrospective protocols when used with screen reader users. In this way, PCTA reduces the efficiency difference of usability evaluation between blind and sighted users.

Immobilized enzyme reactors in HPLC and its application in inhibitor screening: A review

PubMed Central

Fang, Si-Meng; Wang, Hai-Na; Zhao, Zhong-Xi; Wang, Wei-Hong

2011-01-01

This paper sets out to summarize the literatures based on immobilized enzyme bio-chromatography and its application in inhibitors screening in the last decade. In order to screen enzyme inhibitors from a mass of compounds in preliminary screening, multi-pore materials with good biocompatibility are used for the supports of immobilizing enzymes, and then the immobilized enzyme reactor applied as the immobilized enzyme stationary phase in HPLC. Therefore, a technology platform of high throughput screening is gradually established to screen the enzyme inhibitors as new anti-tumor drugs. Here, we briefly summarize the selective methods of supports, immobilization techniques, co-immobilized enzymes system and the screening model. PMID:29403726

Surfactants as blackbird stressing agents

USGS Publications Warehouse

Lefebvre, P.W.; Seubert, J.L.

1970-01-01

Applications of wetting-agent solutions produce mortality in birds. The exact cause of death is undetermined but it is believed that destruction of the insulating qualities of the plumage permits ambient cold temperatures and evaporation to lower the body temperature to a lethal level. The original concept of using these materials as bird-control tools was developed in 1958 at the Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife Laurel, Maryland. Early field trials by personnel of the Division of Wildlife Services and the Denver Wildlife Research Center indicated that ground-application techniques had promise but limitations of the equipment precluded successful large-scale roost treatments. In 1966, Patuxent Center personnel began using tanker-type aircraft to evaluate high-volume aerial applications of wetting agents. The success of these tests led to the use of small aircraft to make low-volume, high-concentration aerial applications just prior to expected rainfall. Recent trials of the low-volume method show that, with some limitations, it is effective, inexpensive, and safe to the environment. Current research emphasizes the screening of new candidate materials for efficacy, biodegradability, and toxicity to plants and non-target animals, as well as basic investigations of the avian physiological mechanisms involved. Field trials to develop more effective application techniques will continue.

Leading-Edge Votex-System Details Obtained on F-106B Aircraft Using a Rotating Vapor Screen and Surface Techniques

NASA Technical Reports Server (NTRS)

Lamar, John E.; Brandon, Jay; Stacy, Kathryn; Johnson, Thomas D., Jr.; Severance, Kurt; Childers, Brooks A.

1993-01-01

A flight research program to study the flow structure and separated-flow origins over an F-106B aircraft wing is described. The flight parameters presented include Mach numbers from 0.26 to 0.81, angles of attack from 8.5 deg to 22.5 deg, Reynolds numbers from 22.6 x 10(exp 6) to 57.3 x 10(exp 6) and load factors from 0.9 to 3.9 times the acceleration due to gravity. Techniques for vapor screens, image enhancement, photogrammetry, and computer graphics are integrated to analyze vortex-flow systems. Emphasis is placed on the development and application of the techniques. The spatial location of vortex cores and their tracks over the wing are derived from the analysis. Multiple vortices are observed and are likely attributed to small surface distortions in the wing leading-edge region. A major thrust is to correlate locations of reattachment lines obtained from the off-surface (vapor-screen) observations with those obtained from on-surface oil-flow patterns and pressure-port data. Applying vapor-screen image data to approximate reattachment lines is experimental, but depending on the angle of attack, the agreement with oil-flow results is generally good. Although surface pressure-port data are limited, the vapor-screen data indicate reattachment point occurrences consistent with the available data.

Maintaining quality in the UK breast screening program

NASA Astrophysics Data System (ADS)

Gale, Alastair

2010-02-01

Breast screening in the UK has been implemented for over 20 years and annually nearly two million women are now screened with an estimated 1,400 lives saved. Nationally, some 700 individuals interpret screening mammograms in almost 110 screening centres. Currently, women aged 50 to 70 are invited for screening every three years and by 2012 this age range will increase to 47 - 73 years. There is a rapid ongoing transition from using film mammograms to full field digital mammography such that in 2010 every screening centre will be partly digital. An early, and long running, concern has been how to ensure the highest quality of imaging interpretation across the UK, an issue enhanced by the use of a three year screening interval. To partly address this question a self assessment scheme was developed in 1988 and subsequently implemented nationally in the UK as a virtually mandatory activity. The scheme is detailed from its beginnings, through its various developments to current incarnation and future plans. This encompasses both radiological (single view screening, two view screening, mammographic film and full field digital mammography) as well as design changes (cases reported by means of: form filling; PDA; tablet PC; iPhone, and the internet). The scheme provides a rich data source which is regularly studied to examine different aspects of radiological performance. Overall it aids screening radiologists by giving them regular access to a range of difficult exemplar cases together with feedback on their performance as compared to their peers.

Real-Time Optical Image Processing Techniques

DTIC Science & Technology

1988-10-31

pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the modification of micro-chan- nel spatial...required for non-linear operation. Real-time nonlinear processing was performed using the halftone screen and MSLM. The experiments showed the effectiveness...pulse frequency modulation has been pursued through the analysis, design, and fabrication of pulse frequency modulated halftone screens and the

Public stated preferences and predicted uptake for genome-based colorectal cancer screening

PubMed Central

2014-01-01

Background Emerging developments in nanomedicine allow the development of genome-based technologies for non-invasive and individualised screening for diseases such as colorectal cancer. The main objective of this study was to measure user preferences for colorectal cancer screening using a nanopill. Methods A discrete choice experiment was used to estimate the preferences for five competing diagnostic techniques including the nanopill and iFOBT. Alternative screening scenarios were described using five attributes namely: preparation involved, sensitivity, specificity, complication rate and testing frequency. Fourteen random and two fixed choice tasks, each consisting of three alternatives, were offered to 2225 individuals. Data were analysed using the McFadden conditional logit model. Results Thirteen hundred and fifty-six respondents completed the questionnaire. The most important attributes (and preferred levels) were the screening technique (nanopill), sensitivity (100%) and preparation (no preparation). Stated screening uptake for the nanopill was 79%, compared to 76% for iFOBT. In the case of screening with the nanopill, the percentage of people preferring not to be screened would be reduced from 19.2% (iFOBT) to 16.7%. Conclusions Although the expected benefits of nanotechnology based colorectal cancer screening are improved screening uptake, assuming more accurate test results and less preparation involved, the relative preference of the nanopill is only slightly higher than the iFOBT. Estimating user preferences during the development of diagnostic technologies could be used to identify relative performance, including perceived benefits and harms compared to competitors allowing for significant changes to be made throughout the process of development. PMID:24642027

Expert opinion on best practice guidelines and competency framework for visual screening in children.

PubMed

Lança, Carla

2013-09-01

Screening programs to detect visual abnormalities in children vary among countries. The aim of this study is to describe experts' perception of best practice guidelines and competency framework for visual screening in children. A qualitative focus group technique was applied during the Portuguese national orthoptic congress to obtain the perception of an expert panel of 5 orthoptists and 2 ophthalmologists with experience in visual screening for children (mean age 53.43 years, SD ± 9.40). The panel received in advance a script with the description of three tuning competencies dimensions (instrumental, systemic, and interpersonal) for visual screening. The session was recorded in video and audio. Qualitative data were analyzed using a categorical technique. According to experts' views, six tests (35.29%) have to be included in a visual screening: distance visual acuity test, cover test, bi-prism or 4/6(Δ) prism, fusion, ocular movements, and refraction. Screening should be performed according to the child age before and after 3 years of age (17.65%). The expert panel highlighted the influence of the professional experience in the application of a screening protocol (23.53%). They also showed concern about the false negatives control (23.53%). Instrumental competencies were the most cited (54.09%), followed by interpersonal (29.51%) and systemic (16.4%). Orthoptists should have professional experience before starting to apply a screening protocol. False negative results are a concern that has to be more thoroughly investigated. The proposed framework focuses on core competencies highlighted by the expert panel. Competencies programs could be important do develop better screening programs.

Differentially pumped spray deposition as a rapid screening tool for organic and perovskite solar cells.

PubMed

Jung, Yen-Sook; Hwang, Kyeongil; Scholes, Fiona H; Watkins, Scott E; Kim, Dong-Yu; Vak, Doojin

2016-02-08

We report a spray deposition technique as a screening tool for solution processed solar cells. A dual-feed spray nozzle is introduced to deposit donor and acceptor materials separately and to form blended films on substrates in situ. Using a differential pump system with a motorised spray nozzle, the effect of film thickness, solution flow rates and the blend ratio of donor and acceptor materials on device performance can be found in a single experiment. Using this method, polymer solar cells based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) are fabricated with numerous combinations of thicknesses and blend ratios. Results obtained from this technique show that the optimum ratio of materials is consistent with previously reported values confirming this technique is a very useful and effective screening method. This high throughput screening method is also used in a single-feed configuration. In the single-feed mode, methylammonium iodide solution is deposited on lead iodide films to create a photoactive layer of perovskite solar cells. Devices featuring a perovskite layer fabricated by this spray process demonstrated a power conversion efficiencies of up to 7.9%.

Automatic screening and classification of diabetic retinopathy and maculopathy using fuzzy image processing.

PubMed

Rahim, Sarni Suhaila; Palade, Vasile; Shuttleworth, James; Jayne, Chrisina

2016-12-01

Digital retinal imaging is a challenging screening method for which effective, robust and cost-effective approaches are still to be developed. Regular screening for diabetic retinopathy and diabetic maculopathy diseases is necessary in order to identify the group at risk of visual impairment. This paper presents a novel automatic detection of diabetic retinopathy and maculopathy in eye fundus images by employing fuzzy image processing techniques. The paper first introduces the existing systems for diabetic retinopathy screening, with an emphasis on the maculopathy detection methods. The proposed medical decision support system consists of four parts, namely: image acquisition, image preprocessing including four retinal structures localisation, feature extraction and the classification of diabetic retinopathy and maculopathy. A combination of fuzzy image processing techniques, the Circular Hough Transform and several feature extraction methods are implemented in the proposed system. The paper also presents a novel technique for the macula region localisation in order to detect the maculopathy. In addition to the proposed detection system, the paper highlights a novel online dataset and it presents the dataset collection, the expert diagnosis process and the advantages of our online database compared to other public eye fundus image databases for diabetic retinopathy purposes.

Current applications of high-resolution mass spectrometry for the analysis of new psychoactive substances: a critical review.

PubMed

Pasin, Daniel; Cawley, Adam; Bidny, Sergei; Fu, Shanlin

2017-10-01

The proliferation of new psychoactive substances (NPS) in recent years has resulted in the development of numerous analytical methods for the detection and identification of known and unknown NPS derivatives. High-resolution mass spectrometry (HRMS) has been identified as the method of choice for broad screening of NPS in a wide range of analytical contexts because of its ability to measure accurate masses using data-independent acquisition (DIA) techniques. Additionally, it has shown promise for non-targeted screening strategies that have been developed in order to detect and identify novel analogues without the need for certified reference materials (CRMs) or comprehensive mass spectral libraries. This paper reviews the applications of HRMS for the analysis of NPS in forensic drug chemistry and analytical toxicology. It provides an overview of the sample preparation procedures in addition to data acquisition, instrumental analysis, and data processing techniques. Furthermore, it gives an overview of the current state of non-targeted screening strategies with discussion on future directions and perspectives of this technique. Graphical Abstract Missing the bullseye - a graphical respresentation of non-targeted screening. Image courtesy of Christian Alonzo.

Differentially pumped spray deposition as a rapid screening tool for organic and perovskite solar cells

PubMed Central

Jung, Yen-Sook; Hwang, Kyeongil; Scholes, Fiona H.; Watkins, Scott E.; Kim, Dong-Yu; Vak, Doojin

2016-01-01

We report a spray deposition technique as a screening tool for solution processed solar cells. A dual-feed spray nozzle is introduced to deposit donor and acceptor materials separately and to form blended films on substrates in situ. Using a differential pump system with a motorised spray nozzle, the effect of film thickness, solution flow rates and the blend ratio of donor and acceptor materials on device performance can be found in a single experiment. Using this method, polymer solar cells based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) are fabricated with numerous combinations of thicknesses and blend ratios. Results obtained from this technique show that the optimum ratio of materials is consistent with previously reported values confirming this technique is a very useful and effective screening method. This high throughput screening method is also used in a single-feed configuration. In the single-feed mode, methylammonium iodide solution is deposited on lead iodide films to create a photoactive layer of perovskite solar cells. Devices featuring a perovskite layer fabricated by this spray process demonstrated a power conversion efficiencies of up to 7.9%. PMID:26853266

Resolution V fractional factorial design for screening of factors affecting weakly basic drugs liposomal systems.

PubMed

Nageeb El-Helaly, Sara; Habib, Basant A; Abd El-Rahman, Mohamed K

2018-07-01

This study aims to investigate factors affecting weakly basic drugs liposomal systems. Resolution V fractional factorial design (2 V 5-1 ) is used as an example of screening designs that would better be used as a wise step before proceeding with detailed factors effects or optimization studies. Five factors probable to affect liposomal systems of weakly basic drugs were investigated using Amisulpride as a model drug. Factors studied were; A: Preparation technique B: Phosphatidyl choline (PhC) amount (mg) C: Cholesterol: PhC molar ratio, D: Hydration volume (ml) and E: Sonication type. Levels investigated were; Ammonium sulphate-pH gradient technique or Transmembrane zinc chelation-pH gradient technique, 200 or 400 mg, 0 or 0.5, 10 or 20 ml and bath or probe sonication for A, B, C, D and E respectively. Responses measured were Particle size (PS) (nm), Zeta potential (ZP) (mV) and Entrapment efficiency percent (EE%). Ion selective electrode was used as a novel method for measuring unentrapped drug concentration and calculating entrapment efficiency without the need for liposomal separation. Factors mainly affecting the studied responses were Cholesterol: PhC ratio and hydration volume for PS, preparation technique for ZP and preparation technique and hydration volume for EE%. The applied 2 V 5-1 design enabled the use of only 16 trial combinations for screening the influence of five factors on weakly basic drugs liposomal systems. This clarifies the value of the use of screening experiments before extensive investigation of certain factors in detailed optimization studies. Copyright © 2018 Elsevier B.V. All rights reserved.

Phage display: concept, innovations, applications and future.

PubMed

Pande, Jyoti; Szewczyk, Magdalena M; Grover, Ashok K

2010-01-01

Phage display is the technology that allows expression of exogenous (poly)peptides on the surface of phage particles. The concept is simple in principle: a library of phage particles expressing a wide diversity of peptides is used to select those that bind the desired target. The filamentous phage M13 is the most commonly used vector to create random peptide display libraries. Several methods including recombinant techniques have been developed to increase the diversity of the library. On the other extreme, libraries with various biases can be created for specific purposes. For instance, when the sequence of the peptide that binds the target is known, its affinity and selectivity can be increased by screening libraries created with limited mutagenesis of the peptide. Phage libraries are screened for binding to synthetic or native targets. The initial screening of library by basic biopanning has been extended to column chromatography including negative screening and competition between selected phage clones to identify high affinity ligands with greater target specificity. The rapid isolation of specific ligands by phage display is advantageous in many applications including selection of inhibitors for the active and allosteric sites of the enzymes, receptor agonists and antagonists, and G-protein binding modulatory peptides. Phage display has been used in epitope mapping and analysis of protein-protein interactions. The specific ligands isolated from phage libraries can be used in therapeutic target validation, drug design and vaccine development. Phage display can also be used in conjunction with other methods. The past innovations and those to come promise a bright future for this field. Copyright © 2010 Elsevier Inc. All rights reserved.

Clinical Validity of hearScreen™ Smartphone Hearing Screening for School Children.

PubMed

Mahomed-Asmail, Faheema; Swanepoel, De Wet; Eikelboom, Robert H; Myburgh, Hermanus C; Hall, James

2016-01-01

The study aimed to determine the validity of a smartphone hearing screening technology (hearScreen™) compared with conventional screening audiometry in terms of (1) sensitivity and specificity, (2) referral rate, and (3) test time. One thousand and seventy school-age children in grades 1 to 3 (8 ± 1.1 average years) were recruited from five public schools. Children were screened twice, once using conventional audiometry and once with the smartphone hearing screening. Screening was conducted in a counterbalanced sequence, alternating initial screen between conventional or smartphone hearing screening. No statistically significant difference in performance between techniques was noted, with smartphone screening demonstrating equivalent sensitivity (75.0%) and specificity (98.5%) to conventional screening audiometry. While referral rates were lower with the smartphone screening (3.2 vs. 4.6%), it was not significantly different (p > 0.05). Smartphone screening (hearScreen™) was 12.3% faster than conventional screening. Smartphone hearing screening using the hearScreen™ application is accurate and time efficient.

Chemical Characterization of the Pyrotechnically Disseminated 66MM Red Phosphorous Smoke Screening IR, Vehicle Launched Grenade

DTIC Science & Technology

2008-07-01

for the redesign of the previously fielded 66mm M76 grenade. Although the M76 grenades provided effective screening in the visual and thermal IR...Environmental and Field Testing Team, Engineering Directorate (ECBC), for coordinating and transporting the test items to the downrange testing site and to...13 2.2 Experimental Design-Downrange Testing ............................................. 14 2.3

Large-Area Cross-Aligned Silver Nanowire Electrodes for Flexible, Transparent, and Force-Sensitive Mechanochromic Touch Screens.

PubMed

Cho, Seungse; Kang, Saewon; Pandya, Ashish; Shanker, Ravi; Khan, Ziyauddin; Lee, Youngsu; Park, Jonghwa; Craig, Stephen L; Ko, Hyunhyub

2017-04-25

Silver nanowire (AgNW) networks are considered to be promising structures for use as flexible transparent electrodes for various optoelectronic devices. One important application of AgNW transparent electrodes is the flexible touch screens. However, the performances of flexible touch screens are still limited by the large surface roughness and low electrical to optical conductivity ratio of random network AgNW electrodes. In addition, although the perception of writing force on the touch screen enables a variety of different functions, the current technology still relies on the complicated capacitive force touch sensors. This paper demonstrates a simple and high-throughput bar-coating assembly technique for the fabrication of large-area (>20 × 20 cm 2 ), highly cross-aligned AgNW networks for transparent electrodes with the sheet resistance of 21.0 Ω sq -1 at 95.0% of optical transmittance, which compares favorably with that of random AgNW networks (sheet resistance of 21.0 Ω sq -1 at 90.4% of optical transmittance). As a proof of concept demonstration, we fabricate flexible, transparent, and force-sensitive touch screens using cross-aligned AgNW electrodes integrated with mechanochromic spiropyran-polydimethylsiloxane composite film. Our force-sensitive touch screens enable the precise monitoring of dynamic writings, tracing and drawing of underneath pictures, and perception of handwriting patterns with locally different writing forces. The suggested technique provides a robust and powerful platform for the controllable assembly of nanowires beyond the scale of conventional fabrication techniques, which can find diverse applications in multifunctional flexible electronic and optoelectronic devices.

Techniques for inventorying manmade impacts in roadway environments.

Treesearch

Dale R. Potter; J. Alan. Wagar

1971-01-01

Four techniques for inventorying manmade impacts along roadway corridors were devised and compared. Ground surveillance and ground photography techniques recorded impacts within the corridor visible from the road. Techniques on large- and small-scale aerial photography recorded impacts within a more complete corridor that included areas screened from the road by...

Non-invasive screening for Alzheimer's disease by sensing salivary sugar using Drosophila cells expressing gustatory receptor (Gr5a) immobilized on an extended gate ion-sensitive field-effect transistor (EG-ISFET) biosensor.

PubMed

Lau, Hui-Chong; Lee, In-Kyu; Ko, Pan-Woo; Lee, Ho-Won; Huh, Jeung-Soo; Cho, Won-Ju; Lim, Jeong-Ok

2015-01-01

Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD). In the present study, we developed a highly sensitive, cell-based biosensor to detect trehalose levels in patient saliva. The developed biosensor relies on the overexpression of sugar sensitive gustatory receptors (Gr5a) in Drosophila cells to detect the salivary trehalose. The cell-based biosensor was built on the foundation of an improved extended gate ion-sensitive field-effect transistor (EG-ISFET). Using an EG-ISFET, instead of a traditional ion-sensitive field-effect transistor (ISFET), resulted in an increase in the sensitivity and reliability of detection. The biosensor was designed with the gate terminals segregated from the conventional ISFET device. This design allows the construction of an independent reference and sensing region for simultaneous and accurate measurements of samples from controls and patients respectively. To investigate the efficacy of the cell-based biosensor for AD screening, we collected 20 saliva samples from each of the following groups: participants diagnosed with AD, participants diagnosed with Parkinson's disease (PD), and a control group composed of healthy individuals. We then studied the response generated from the interaction of the salivary trehalose of the saliva samples and the Gr5a in the immobilized cells on an EG-ISFET sensor. The cell-based biosensor significantly distinguished salivary sugar, trehalose of the AD group from the PD and control groups. Based on these findings, we propose that salivary trehalose, might be a potential biomarker for AD and could be detected using our cell-based EG-ISFET biosensor. The cell-based EG-ISFET biosensor provides a sensitive and direct approach for salivary sugar detection and may be used in the future as a screening method for AD.

Field Emission Enhancement and the Field-Screening Effect Reduction using Carbon Nanopipettes as Cold Cathodes

NASA Astrophysics Data System (ADS)

Safir, Abdelilah; Mudd, David; Yazdanpanah, Mehdi; Dobrokhotov, Vladimir; Sumanasekera, Gamini; Cohn, Robert

2008-03-01

In this work, we report a recent experimental study of high emission current densities exceeding 10mA/cm^2 and breakdown electric field lower than 5Volts/μm from novel cold cathodes such as conical shaped carbon nanopipettes (CNP). CNP were grown by CVD on Pt wire and have apex as sharp as 10nm with length between 3-6μm. The emission experiments were conducted under vacuum in a scanning electron microscope for individual CNP and in a dedicated chamber for bulk samples. CNP's conical bases and low density contribute significantly to the reduction of the screening effect and to the field emission enhancement. The experimental value for the field enhancement factor, γ, was about 867. Comparing emission results taken from CNP and aligned multiwall carbon nanotubes (MWNT) show that the ratio between γCNP and γMWNT is ˜1.6 which contributes to the reduction of screening effect. The emission from multilayers of graphene was also studied. High emission current (20μA) demonstrates promising emission properties of graphene.

A Modeling Study of the Spatial Structure of Electric Fields Generated by Electrified Clouds with Screening Layers

NASA Astrophysics Data System (ADS)

Biagi, C. J.; Cummins, K. L.

2015-12-01

The growing possibility of inexpensive airborne observations of electric fields using one or more small UAVs increases the importance of understanding what can be determined about cloud electrification and associated electric fields outside cloud boundaries. If important information can be inferred from carefully selected flight paths outside of a cloud, then the aircraft and its instrumentation will be much cheaper to develop and much safer to operate. These facts have led us to revisit this long-standing topic using quasi-static, finite-element modeling inside and outside arbitrarily shaped clouds with a variety of internal charge distributions. In particular, we examine the effect of screening layers on electric fields outside of electrified clouds by comparing modeling results for charged clouds having electrical conductivities that are both equal to and lower than the surrounding clear air. The comparisons indicate that the spatial structure of the electric field is approximately the same regardless of the difference in the conductivities between the cloud and clear air and the formation of a screening layer, even for altitude-dependent electrical conductivities. This result is consistent with the numerical modeling results reported by Driscoll et al [1992]. The similarity of the spatial structure of the electric field outside of clouds with and without a screening layer suggests that "bulk" properties related to cloud electrification might be determined using measurements of the electric field at multiple locations in space outside the cloud, particularly at altitude. Finally, for this somewhat simplified model, the reduction in electric field magnitude outside the cloud due to the presence of a screening layer exhibits a simple dependence on the difference in conductivity between the cloud and clear air. These results are particularly relevant for studying clouds that are not producing lightning, such as developing thunderstorms and decaying anvils associated with mature storm systems.Driscoll K.T., R.J. Blakeslee, M.E. Baginski, 1992, A modeling study of the time-averaged electric currents in the vicinity of isolated thunderstorms, J. Geophys. Res., 97, D11, pp 11535-11551.

Computational materials design of crystalline solids.

PubMed

Butler, Keith T; Frost, Jarvist M; Skelton, Jonathan M; Svane, Katrine L; Walsh, Aron

2016-11-07

The modelling of materials properties and processes from first principles is becoming sufficiently accurate as to facilitate the design and testing of new systems in silico. Computational materials science is both valuable and increasingly necessary for developing novel functional materials and composites that meet the requirements of next-generation technology. A range of simulation techniques are being developed and applied to problems related to materials for energy generation, storage and conversion including solar cells, nuclear reactors, batteries, fuel cells, and catalytic systems. Such techniques may combine crystal-structure prediction (global optimisation), data mining (materials informatics) and high-throughput screening with elements of machine learning. We explore the development process associated with computational materials design, from setting the requirements and descriptors to the development and testing of new materials. As a case study, we critically review progress in the fields of thermoelectrics and photovoltaics, including the simulation of lattice thermal conductivity and the search for Pb-free hybrid halide perovskites. Finally, a number of universal chemical-design principles are advanced.

Whole embryo culture: a "New" technique that enabled decades of mechanistic discoveries.

PubMed

Ellis-Hutchings, Robert G; Carney, Edward W

2010-08-01

Denis New's development of the rodent whole embryo culture (WEC) method in the early 1960s was a groundbreaking achievement that gave embryologists and teratologists an unprecedented degree of access to the developing postimplantation rodent embryo. In the five decades since its development, WEC has enabled detailed investigations into the regulation of normal embryo development as well as a plethora of research on mechanisms of teratogenesis as induced by a wide range of agents. In addition, WEC is one of the few techniques that has been validated for use in teratogenicity screening of drugs and chemicals. In this review, we retrace the steps leading to New's development of WEC, and highlight many examples in which WEC played a crucial role leading to important discoveries in teratological research. The impact of WEC on the field of teratology has been enormous, and it is anticipated that WEC will remain a preferred tool for teratologists and embryologists seeking to interrogate embryo development for many years to come. Copyright 2010 Wiley-Liss, Inc.

Fast correction approach for wavefront sensorless adaptive optics based on a linear phase diversity technique.

PubMed

Yue, Dan; Nie, Haitao; Li, Ye; Ying, Changsheng

2018-03-01

Wavefront sensorless (WFSless) adaptive optics (AO) systems have been widely studied in recent years. To reach optimum results, such systems require an efficient correction method. This paper presents a fast wavefront correction approach for a WFSless AO system mainly based on the linear phase diversity (PD) technique. The fast closed-loop control algorithm is set up based on the linear relationship between the drive voltage of the deformable mirror (DM) and the far-field images of the system, which is obtained through the linear PD algorithm combined with the influence function of the DM. A large number of phase screens under different turbulence strengths are simulated to test the performance of the proposed method. The numerical simulation results show that the method has fast convergence rate and strong correction ability, a few correction times can achieve good correction results, and can effectively improve the imaging quality of the system while needing fewer measurements of CCD data.

Fuzzy System-Based Target Selection for a NIR Camera-Based Gaze Tracker

PubMed Central

Naqvi, Rizwan Ali; Arsalan, Muhammad; Park, Kang Ryoung

2017-01-01

Gaze-based interaction (GBI) techniques have been a popular subject of research in the last few decades. Among other applications, GBI can be used by persons with disabilities to perform everyday tasks, as a game interface, and can play a pivotal role in the human computer interface (HCI) field. While gaze tracking systems have shown high accuracy in GBI, detecting a user’s gaze for target selection is a challenging problem that needs to be considered while using a gaze detection system. Past research has used the blinking of the eyes for this purpose as well as dwell time-based methods, but these techniques are either inconvenient for the user or requires a long time for target selection. Therefore, in this paper, we propose a method for fuzzy system-based target selection for near-infrared (NIR) camera-based gaze trackers. The results of experiments performed in addition to tests of the usability and on-screen keyboard use of the proposed method show that it is better than previous methods. PMID:28420114

New-type planar field emission display with superaligned carbon nanotube yarn emitter.

PubMed

Liu, Peng; Wei, Yang; Liu, Kai; Liu, Liang; Jiang, Kaili; Fan, Shoushan

2012-05-09

With the superaligned carbon nanotube yarn as emitter, we have fabricated a 16 × 16 pixel field emission display prototype by adopting screen printing and laser cutting technologies. A planar diode field emission structure has been adopted. A very sharp carbon nanotube yarn tip emitter can be formed by laser cutting. Low voltage phosphor was coated on the anode electrodes also by screen printing. With a specially designed circuit, we have demonstrated the dynamic character display with the field emission display prototype. The emitter material and fabrication technologies in this paper are both easy to scale up to large areas.

Optimization of PCR Condition: The First Study of High Resolution Melting Technique for Screening of APOA1 Variance.

PubMed

Wahyuningsih, Hesty; K Cayami, Ferdy; Bahrudin, Udin; A Sobirin, Mochamad; Ep Mundhofir, Farmaditya; Mh Faradz, Sultana; Hisatome, Ichiro

2017-03-01

High resolution melting (HRM) is a post-PCR technique for variant screening and genotyping based on the different melting points of DNA fragments. The advantages of this technique are that it is fast, simple, and efficient and has a high output, particularly for screening of a large number of samples. APOA1 encodes apolipoprotein A1 (apoA1) which is a major component of high density lipoprotein cholesterol (HDL-C). This study aimed to obtain an optimal quantitative polymerase chain reaction (qPCR)-HRM condition for screening of APOA1 variance. Genomic DNA was isolated from a peripheral blood sample using the salting out method. APOA1 was amplified using the RotorGeneQ 5Plex HRM. The PCR product was visualized with the HRM amplification curve and confirmed using gel electrophoresis. The melting profile was confirmed by looking at the melting curve. Five sets of primers covering the translated region of APOA1 exons were designed with expected PCR product size of 100-400 bps. The amplified segments of DNA were amplicons 2, 3, 4A, 4B, and 4C. Amplicons 2, 3 and 4B were optimized at an annealing temperature of 60 °C at 40 PCR cycles. Amplicon 4A was optimized at an annealing temperature of 62 °C at 45 PCR cycles. Amplicon 4C was optimized at an annealing temperature of 63 °C at 50 PCR cycles. In addition to the suitable procedures of DNA isolation and quantification, primer design and an estimated PCR product size, the data of this study showed that appropriate annealing temperature and PCR cycles were important factors in optimization of HRM technique for variant screening in APOA1 .

Optimization of PCR Condition: The First Study of High Resolution Melting Technique for Screening of APOA1 Variance

PubMed Central

Wahyuningsih, Hesty; K Cayami, Ferdy; Bahrudin, Udin; A Sobirin, Mochamad; EP Mundhofir, Farmaditya; MH Faradz, Sultana; Hisatome, Ichiro

2017-01-01

Background High resolution melting (HRM) is a post-PCR technique for variant screening and genotyping based on the different melting points of DNA fragments. The advantages of this technique are that it is fast, simple, and efficient and has a high output, particularly for screening of a large number of samples. APOA1 encodes apolipoprotein A1 (apoA1) which is a major component of high density lipoprotein cholesterol (HDL-C). This study aimed to obtain an optimal quantitative polymerase chain reaction (qPCR)-HRM condition for screening of APOA1 variance. Methods Genomic DNA was isolated from a peripheral blood sample using the salting out method. APOA1 was amplified using the RotorGeneQ 5Plex HRM. The PCR product was visualized with the HRM amplification curve and confirmed using gel electrophoresis. The melting profile was confirmed by looking at the melting curve. Results Five sets of primers covering the translated region of APOA1 exons were designed with expected PCR product size of 100–400 bps. The amplified segments of DNA were amplicons 2, 3, 4A, 4B, and 4C. Amplicons 2, 3 and 4B were optimized at an annealing temperature of 60 °C at 40 PCR cycles. Amplicon 4A was optimized at an annealing temperature of 62 °C at 45 PCR cycles. Amplicon 4C was optimized at an annealing temperature of 63 °C at 50 PCR cycles. Conclusion In addition to the suitable procedures of DNA isolation and quantification, primer design and an estimated PCR product size, the data of this study showed that appropriate annealing temperature and PCR cycles were important factors in optimization of HRM technique for variant screening in APOA1. PMID:28331418

A rational workflow for sequential virtual screening of chemical libraries on searching for new tyrosinase inhibitors.

PubMed

Le-Thi-Thu, Huong; Casanola-Martín, Gerardo M; Marrero-Ponce, Yovani; Rescigno, Antonio; Abad, Concepcion; Khan, Mahmud Tareq Hassan

2014-01-01

The tyrosinase is a bifunctional, copper-containing enzyme widely distributed in the phylogenetic tree. This enzyme is involved in the production of melanin and some other pigments in humans, animals and plants, including skin pigmentations in mammals, and browning process in plants and vegetables. Therefore, enzyme inhibitors has been under the attention of the scientist community, due to its broad applications in food, cosmetic, agricultural and medicinal fields, to avoid the undesirable effects of abnormal melanin overproduction. However, the research of novel chemical with antityrosinase activity demands the use of more efficient tools to speed up the tyrosinase inhibitors discovery process. This chapter is focused in the different components of a predictive modeling workflow for the identification and prioritization of potential new compounds with activity against the tyrosinase enzyme. In this case, two structure chemical libraries Spectrum Collection and Drugbank are used in this attempt to combine different virtual screening data mining techniques, in a sequential manner helping to avoid the usually expensive and time consuming traditional methods. Some of the sequential steps summarize here comprise the use of drug-likeness filters, similarity searching, classification and potency QSAR multiclassifier systems, modeling molecular interactions systems, and similarity/diversity analysis. Finally, the methodologies showed here provide a rational workflow for virtual screening hit analysis and selection as a promissory drug discovery strategy for use in target identification phase.

Scanning laser ophthalmoscope fundus cyclometry in near-natural viewing conditions.

PubMed

Ehrt, O; Boergen, K P

2001-09-01

For a better understanding of motor and sensory adaptations in cyclodeviations, subjective and objective ocular torsion have to be measured under the same conditions. The search coil technique and videooculography allow natural viewing but only assess relative cycloduction, the dynamics of torsion over a short period of time. Cycloposition, on the other hand, can be measured by analysing the position of the foveola relative to the optic disc with fundus photographs but only in nonphysiological viewing. The aim of the study was to develop a technique that allows natural viewing conditions during fundus cyclometry. The scanning laser beam of the SLO was deflected by 90 degrees with a semitransparent mirror in front of the patient's eyes. The patient was able to look through the semitransparent mirror with both eyes into the room, e.g. at Harms' tangent screen. The infrared SLO images the central retina via the mirror through the undilated pupil. Digital image analysis quantifies the cycloposition of the eye. Controlled head movements while fixating the centre of Harms' tangent screen allow measurements in reproducible gaze positions. The semitransparent mirror reduces SLO image brightness, but image quality is sufficient for cyclometry after contrast enhancement. The laser light can be vaguely perceived by the patient but does not interfere with natural viewing. Reproducibility of the measurement is within +/- 1 degree SD. Our modification of SLO fundus cyclometry allows direct measurements of cycloposition in natural viewing conditions. This opens a new field for investigations of cyclodeviations and their sensory and motor adaptations.

Hyperspectral small animal fluorescence imaging: spectral selection imaging

NASA Astrophysics Data System (ADS)

Leavesley, Silas; Jiang, Yanan; Patsekin, Valery; Hall, Heidi; Vizard, Douglas; Robinson, J. Paul

2008-02-01

Molecular imaging is a rapidly growing area of research, fueled by needs in pharmaceutical drug-development for methods for high-throughput screening, pre-clinical and clinical screening for visualizing tumor growth and drug targeting, and a growing number of applications in the molecular biology fields. Small animal fluorescence imaging employs fluorescent probes to target molecular events in vivo, with a large number of molecular targeting probes readily available. The ease at which new targeting compounds can be developed, the short acquisition times, and the low cost (compared to microCT, MRI, or PET) makes fluorescence imaging attractive. However, small animal fluorescence imaging suffers from high optical scattering, absorption, and autofluorescence. Much of these problems can be overcome through multispectral imaging techniques, which collect images at different fluorescence emission wavelengths, followed by analysis, classification, and spectral deconvolution methods to isolate signals from fluorescence emission. We present an alternative to the current method, using hyperspectral excitation scanning (spectral selection imaging), a technique that allows excitation at any wavelength in the visible and near-infrared wavelength range. In many cases, excitation imaging may be more effective at identifying specific fluorescence signals because of the higher complexity of the fluorophore excitation spectrum. Because the excitation is filtered and not the emission, the resolution limit and image shift imposed by acousto-optic tunable filters have no effect on imager performance. We will discuss design of the imager, optimizing the imager for use in small animal fluorescence imaging, and application of spectral analysis and classification methods for identifying specific fluorescence signals.

Evaluation of colorimetric loop-mediated isothermal amplification assay for visual detection of Streptococcus agalactiae and Streptococcus iniae in tilapia.

PubMed

Suebsing, R; Kampeera, J; Tookdee, B; Withyachumnarnkul, B; Turner, W; Kiatpathomchai, W

2013-10-01

Streptococcus agalactiae and Strep. iniae are bacterial pathogens that cause streptococcosis in many fish species. An accelerated colorimetric loop-mediated isothermal amplification (LAMP) assay with pre-addition of calcein was established, and the transmission and detection of Strep. agalactiae and Strep. iniae in tilapia under natural aquatic environment were investigated. A positive reaction was observed by a colour change from orange to green through the naked eyes after completion at 63°C for 30 min with 10 times higher sensitivity than that of nested PCR assays and without cross-amplification with other fish bacterial pathogens. All sample types of Nile and red tilapia (broodstock, fertilized egg, fry) were Strep. agalactiae- and Strep. iniae positive by this new method, implying that they could be vertically transmitted. With its application for screening broodstock and fry before stocking and for monitoring fish health in grow-out ponds, the method would become very useful in fish farming industry. The application of colorimetric LAMP with pre-addition of calcein offers simple, rapid and sensitive technique with applicability for small field laboratories. This technique explored the possible vertical transmission mode of Strep. agalactiae and Strep. iniae under natural aquatic environment. It could be such preliminary data provided for the screening broodstock before breeding and/or the specific-pathogen-free production. © 2013 The Society for Applied Microbiology.

[Pulmonary resection using video-assisted thoracoscopic surgery--20 years experience].

PubMed

Baste, J-M; Orsini, B; Rinieri, P; Melki, J; Peillon, C

2014-04-01

Major lung resection using minimally invasive techniques - video-assisted thoracoscopic surgery (VATS) - was first described 20 years ago. However, its development has been slow in many countries because the value of this approach has been questioned. Different techniques and definitions of VATS are used and this can be confusing for physicians and surgeons. The benefit of minimally invasive thoracic surgery was not always apparent, while many surgeons pointed to suboptimal operative outcomes. Recently, technological advances (radiology, full HD monitor and new stapler devices) have improved VATS outcomes. The objectives of this review are to emphasize the accepted definition of VATS resection, outline the different techniques developed and their results including morbidity and mortality compared to conventional approaches. Minimally invasive thoracic surgery has not been proven to give superior survival (level one evidence) compared to thoracotomy. A slight advantage has been demonstrated for short-term outcomes. VATS is not a surgical revolution but rather an evolution of surgery. It should be considered together with the new medical environment including stereotactic radiotherapy and radiofrequency. VATS seems to be more accurate in the treatment of small lung lesions diagnosed with screening CT scan. In the academic field, VATS allows easier teaching and diffusion of techniques. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.

Fast widefield techniques for fluorescence and phase endomicroscopy

NASA Astrophysics Data System (ADS)

Ford, Tim N.

Endomicroscopy is a recent development in biomedical optics which gives researchers and physicians microscope-resolution views of intact tissue to complement macroscopic visualization during endoscopy screening. This thesis presents HiLo endomicroscopy and oblique back-illumination endomicroscopy, fast wide-field imaging techniques with fluorescence and phase contrast, respectively. Fluorescence imaging in thick tissue is often hampered by strong out-of-focus background signal. Laser scanning confocal endomicroscopy has been developed for optically-sectioned imaging free from background, but reliance on mechanical scanning fundamentally limits the frame rate and represents significant complexity and expense. HiLo is a fast, simple, widefield fluorescence imaging technique which rejects out-of-focus background signal without the need for scanning. It works by acquiring two images of the sample under uniform and structured illumination and synthesizing an optically sectioned result with real-time image processing. Oblique back-illumination microscopy (OBM) is a label-free technique which allows, for the first time, phase gradient imaging of sub-surface morphology in thick scattering tissue with a reflection geometry. OBM works by back-illuminating the sample with the oblique diffuse reflectance from light delivered via off-axis optical fibers. The use of two diametrically opposed illumination fibers allows simultaneous and independent measurement of phase gradients and absorption contrast. Video-rate single-exposure operation using wavelength multiplexing is demonstrated.

Computational techniques for ECG analysis and interpretation in light of their contribution to medical advances

PubMed Central

Mincholé, Ana; Martínez, Juan Pablo; Laguna, Pablo; Rodriguez, Blanca

2018-01-01

Widely developed for clinical screening, electrocardiogram (ECG) recordings capture the cardiac electrical activity from the body surface. ECG analysis can therefore be a crucial first step to help diagnose, understand and predict cardiovascular disorders responsible for 30% of deaths worldwide. Computational techniques, and more specifically machine learning techniques and computational modelling are powerful tools for classification, clustering and simulation, and they have recently been applied to address the analysis of medical data, especially ECG data. This review describes the computational methods in use for ECG analysis, with a focus on machine learning and 3D computer simulations, as well as their accuracy, clinical implications and contributions to medical advances. The first section focuses on heartbeat classification and the techniques developed to extract and classify abnormal from regular beats. The second section focuses on patient diagnosis from whole recordings, applied to different diseases. The third section presents real-time diagnosis and applications to wearable devices. The fourth section highlights the recent field of personalized ECG computer simulations and their interpretation. Finally, the discussion section outlines the challenges of ECG analysis and provides a critical assessment of the methods presented. The computational methods reported in this review are a strong asset for medical discoveries and their translation to the clinical world may lead to promising advances. PMID:29321268

Accuracy and Feasibility of an Android-Based Digital Assessment Tool for Post Stroke Visual Disorders-The StrokeVision App.

PubMed

Quinn, Terence J; Livingstone, Iain; Weir, Alexander; Shaw, Robert; Breckenridge, Andrew; McAlpine, Christine; Tarbert, Claire M

2018-01-01

Visual impairment affects up to 70% of stroke survivors. We designed an app (StrokeVision) to facilitate screening for common post stroke visual issues (acuity, visual fields, and visual inattention). We sought to describe the test time, feasibility, acceptability, and accuracy of our app-based digital visual assessments against (a) current methods used for bedside screening and (b) gold standard measures. Patients were prospectively recruited from acute stroke settings. Index tests were app-based assessments of fields and inattention performed by a trained researcher. We compared against usual clinical screening practice of visual fields to confrontation, including inattention assessment (simultaneous stimuli). We also compared app to gold standard assessments of formal kinetic perimetry (Goldman or Octopus Visual Field Assessment); and pencil and paper-based tests of inattention (Albert's, Star Cancelation, and Line Bisection). Results of inattention and field tests were adjudicated by a specialist Neuro-ophthalmologist. All assessors were masked to each other's results. Participants and assessors graded acceptability using a bespoke scale that ranged from 0 (completely unacceptable) to 10 (perfect acceptability). Of 48 stroke survivors recruited, the complete battery of index and reference tests for fields was successfully completed in 45. Similar acceptability scores were observed for app-based [assessor median score 10 (IQR: 9-10); patient 9 (IQR: 8-10)] and traditional bedside testing [assessor 10 (IQR: 9-10); patient 10 (IQR: 9-10)]. Median test time was longer for app-based testing [combined time to completion of all digital tests 420 s (IQR: 390-588)] when compared with conventional bedside testing [70 s, (IQR: 40-70)], but shorter than gold standard testing [1,260 s, (IQR: 1005-1,620)]. Compared with gold standard assessments, usual screening practice demonstrated 79% sensitivity and 82% specificity for detection of a stroke-related field defect. This compares with 79% sensitivity and 88% specificity for StrokeVision digital assessment. StrokeVision shows promise as a screening tool for visual complications in the acute phase of stroke. The app is at least as good as usual screening and offers other functionality that may make it attractive for use in acute stroke. https://ClinicalTrials.gov/ct2/show/NCT02539381.

[Overdiagnosis in cancer screening].

PubMed

Cervera Deval, J; Sentís Crivillé, M; Zulueta, J J

2015-01-01

In screening programs, overdiagnosis is defined as the detection of a disease that would have gone undetected without screening when that disease would not have resulted in morbimortality and was treated unnecessarily. Overdiagnosis is a bias inherent in screening and an undesired effect of secondary prevention and improved sensitivity of diagnostic techniques. It is difficult to discriminate a priori between clinically relevant diagnoses and those in which treatment is unnecessary. To minimize the effects of overdiagnosis, screening should be done in patients at risk. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

Quantitative structure-activity relationship analysis and virtual screening studies for identifying HDAC2 inhibitors from known HDAC bioactive chemical libraries.

PubMed

Pham-The, H; Casañola-Martin, G; Diéguez-Santana, K; Nguyen-Hai, N; Ngoc, N T; Vu-Duc, L; Le-Thi-Thu, H

2017-03-01

Histone deacetylases (HDAC) are emerging as promising targets in cancer, neuronal diseases and immune disorders. Computational modelling approaches have been widely applied for the virtual screening and rational design of novel HDAC inhibitors. In this study, different machine learning (ML) techniques were applied for the development of models that accurately discriminate HDAC2 inhibitors form non-inhibitors. The obtained models showed encouraging results, with the global accuracy in the external set ranging from 0.83 to 0.90. Various aspects related to the comparison of modelling techniques, applicability domain and descriptor interpretations were discussed. Finally, consensus predictions of these models were used for screening HDAC2 inhibitors from four chemical libraries whose bioactivities against HDAC1, HDAC3, HDAC6 and HDAC8 have been known. According to the results of virtual screening assays, structures of some hits with pair-isoform-selective activity (between HDAC2 and other HDACs) were revealed. This study illustrates the power of ML-based QSAR approaches for the screening and discovery of potent, isoform-selective HDACIs.

On the Developmental Education Radar Screen--2013

ERIC Educational Resources Information Center

Paulson, Eric J.

2013-01-01

This is the second iteration of the Developmental Education Radar Screen project. As with the first iteration, in 2011, the author uses a "radar screen" metaphor to discuss trends in developmental education based on responses to a series of topics and categories provided by a group of leaders in the educational field. The purpose of this…

Interception of spray drift by border structures. Part 1: wind tunnel experiments.

PubMed

De Schampheleire, M; Nuyttens, D; Dekeyser, D; Verboven, P; Cornelis, W; Gabriels, D; Spanoghe, P

2008-01-01

This research investigated the drift-intercepting potential of structures surrounding the field borders, like artificial screens and crops, which are not yet a part of the drift mitigation measures for field crop sprayers in Belgium. Drift-interception experiments were performed in the wind tunnel of the International Centre for Eremology (Ghent University, Belgium) with various interception structures: Artificial screens with heights of 0.5, 0.75 and 1 m and screen open areas of 16, 36 and 63%; a row of plastic Christmas trees with heights of 0.5 and 0.75 m; and a potato canopy. The interception structure was positioned at 1 m from the field border. From the results it was found that type of border structure has a pronounced effect on the drift interception, while the height of the border structure had no significant effect.

Screening mechanisms at polar oxide heterointerfaces

DOE PAGES

Hong, Seungbum; Nakhmanson, Serge M.; Fong, Dillon D.

2016-06-16

The interfaces of polar oxide heterostructures can display electronic properties unique from the oxides they border, as they require screening from either internal or external sources of charge. The screening mechanism depends on a variety of factors, including the band structure at the interface, the presence of point defects or adsorbates, whether or not the oxide is ferroelectric, and whether or not an external field is applied. In this review, we discuss both theoretical and experimental aspects of different screening mechanisms, giving special emphasis to ways in which the mechanism can be altered to provide novel or tunable functionalities. Wemore » begin with a theoretical introduction to the problem and highlight recent progress in understanding the impact of point defects on polar interfaces. Different case studies are then discussed, for both the high thickness regime, where interfaces must be screened and each interface can be considered separately, and the low thickness regime, where the degree and nature of screening can be manipulated and the interfaces are close enough to interact. As a result, we end with a brief outlook toward new developments in this rapidly progressing field.« less

ELISA test for anti-neutrophil cytoplasm antibodies detection evaluated by a computer screen photo-assisted technique.

PubMed

Filippini, D; Tejle, K; Lundström, I

2005-08-15

The computer screen photo-assisted technique (CSPT), a method for substance classification based on spectral fingerprinting, which involves just a computer screen and a web camera as measuring platform is used here for the evaluation of a prospective enzyme-linked immunosorbent assay (ELISA). A anti-neutrophil cytoplasm antibodies (ANCA-ELISA) test, typically used for diagnosing patients suffering from chronic inflammatory disorders in the skin, joints, blood vessels and other tissues is comparatively tested with a standard microplate reader and CSPT, yielding equivalent results at a fraction of the instrumental costs. The CSPT approach is discussed as a distributed measuring platform allowing decentralized measurements in routine applications, whereas keeping centralized information management due to its natural network embedded operation.

Studies on the Control of Ascochyta Blight in Field Peas (Pisum sativum L.) Caused by Ascochyta pinodes in Zhejiang Province, China

PubMed Central

Liu, Na; Xu, Shengchun; Yao, Xiefeng; Zhang, Guwen; Mao, Weihua; Hu, Qizan; Feng, Zhijuan; Gong, Yaming

2016-01-01

Ascochyta blight, an infection caused by a complex of Ascochyta pinodes, Ascochyta pinodella, Ascochyta pisi, and/or Phoma koolunga, is a destructive disease in many field peas (Pisum sativum L.)-growing regions, and it causes significant losses in grain yield. To understand the composition of fungi associated with this disease in Zhejiang Province, China, a total of 65 single-pycnidiospore fungal isolates were obtained from diseased pea samples collected from 5 locations in this region. These isolates were identified as Ascochyta pinodes by molecular techniques and their morphological and physiological characteristics. The mycelia of ZJ-1 could penetrate pea leaves across the stomas, and formed specific penetration structures and directly pierced leaves. The resistance level of 23 available pea cultivars was tested against their representative isolate A. pinodes ZJ-1 using the excised leaf-assay technique. The ZJ-1 mycelia could penetrate the leaves of all tested cultivars, and they developed typical symptoms, which suggested that all tested cultivars were susceptible to the fungus. Chemical fungicides and biological control agents were screened for management of this disease, and their efficacies were further determined. Most of the tested fungicides (11 out of 14) showed high activity toward ZJ-1 with EC50 < 5 μg/mL. Moreover, fungicides, including tebuconazole, boscalid, iprodione, carbendazim, and fludioxonil, displayed more than 80% disease control efficacy under the recorded conditions. Three biocontrol strains of Bacillus sp. and one of Pantoea agglomerans were isolated from pea-related niches and significantly reduced the severity of disease under greenhouse and field conditions. To our knowledge, this is the first study on ascochyta blight in field peas, and results presented here will be useful for controlling the disease in this area. PMID:27148177

The National Lung Screening Trial (NLST) | Division of Cancer Prevention

Cancer.gov

The National Lung Screening Trial (NLST) compared two ways of detecting lung cancer: low-dose helical computed tomography (CT) and standard chest X-ray. Both chest X-rays and low-dose helical CT scans have been used to find lung cancer early, but the effects of these screening techniques on lung cancer mortality rates had not been determined. NLST enrolled 53,454 current or

Integrality and separability of multitouch interaction techniques in 3D manipulation tasks.

PubMed

Martinet, Anthony; Casiez, Géry; Grisoni, Laurent

2012-03-01

Multitouch displays represent a promising technology for the display and manipulation of data. While the manipulation of 2D data has been widely explored, 3D manipulation with multitouch displays remains largely unexplored. Based on an analysis of the integration and separation of degrees of freedom, we propose a taxonomy for 3D manipulation techniques with multitouch displays. Using that taxonomy, we introduce Depth-Separated Screen-Space (DS3), a new 3D manipulation technique based on the separation of translation and rotation. In a controlled experiment, we compared DS3 with Sticky Tools and Screen-Space. Results show that separating the control of translation and rotation significantly affects performance for 3D manipulation, with DS3 performing faster than the two other techniques.

Thermal smearing and screening in a strong magnetic field for Dirac materials in comparison with the two dimensional electron liquid

NASA Astrophysics Data System (ADS)

Gumbs, Godfrey; Balassis, Antonios; Dahal, Dipendra; Lawrence Glasser, M.

2016-10-01

We compute and compare the effects due to a uniform perpendicular magnetic field as well as temperature on the static polarization functions for monolayer graphene (MLG), associated with the Dirac point, with that for the two-dimensional electron liquid (2DEL) with the use of comprehensive numerical calculations. The relevance of our study to the Friedel oscillations for the screening of the potential for a dilute distribution of impurities is reported too. Our results show substantial differences due to screening for the 2DEL and MLG which have not been given adequate attention previously.

An anomalous interlayer exciton in MoS2

NASA Astrophysics Data System (ADS)

Azhikodan, Dilna; Nautiyal, Tashi; Shallcross, Sam; Sharma, Sangeeta

2016-11-01

The few layer transition metal dichalcogenides are two dimensional materials that have an intrinsic gap of the order of ≈2 eV. The reduced screening in two dimensions implies a rich excitonic physics and, as a consequence, many potential applications in the field of opto-electronics. Here we report that a layer perpendicular electric field, by which the gap size in these materials can be efficiently controlled, generates an anomalous inter-layer exciton whose binding energy is independent of the gap size. We show this originates from the rich gap control and screening physics of TMDCs in a bilayer geometry: gating the bilayer acts on one hand to increase intra-layer screening by reducing the gap and, on the other hand, to decrease the inter-layer screening by field induced charge depletion. This constancy of binding energy is both a striking exception to the universal reduction in binding energy with gap size that all materials are believed to follow, as well as evidence of a degree of control over inter-layer excitons not found in their well studied intra-layer counterparts.

Incidence of elbow injuries in adolescent baseball players: screening by a low field magnetic resonance imaging system specialized for small joints.

PubMed

Okamoto, Yoshikazu; Maehara, Kiyoshi; Kanahori, Tetsuya; Hiyama, Takashi; Kawamura, Takashi; Minami, Manabu

2016-04-01

The aim of this preliminary study was to examine the capability of screening for elbow injuries induced by baseball using a low field small joint MRI system. Sixty-two players in the 4th-6th elementary school grades, with ages ranging from 9 to 12 years, participated in this study. Screening for elbow injuries was performed using a low-magnetic-field (0.2-T) magnetic resonance imaging (MRI) system designed for examinations of small joints of the extremities. Gradient-echo coronal, sagittal, and short-tau inversion recovery (STIR) coronal images of the dominant arm used for pitching were obtained to identify medial collateral ligament (MCL) injuries with or without avulsion fracture and osteochondritis dissecans. All 62 examinations were performed successfully, with 26 players (41.9 %) showing positive findings, all being confined to the MCL. No child showed bone damage. All criteria in the MRI evaluation of injuries showed high agreement rates and kappa values between two radiologists. Screening for early detection of elbow injuries in junior Japanese baseball players can be successfully performed using a low-field MRI system specialized for small joints. The percentage of MCL injury without avulsion fracture was unexpectedly high (41.9 %).

Self-synchronizing Schlieren photography and interferometry for the visualization of unsteady transonic flows

NASA Technical Reports Server (NTRS)

Kadlec, R.

1979-01-01

The use of self synchronizing stroboscopic Schlieren and laser interferometer systems to obtain quantitative space time measurements of distinguished flow surfaces, steakline patterns, and the density field of two dimensional flows that exhibit a periodic content was investigated. A large field single path stroboscopic Schlieren system was designed, constructed and successfully applied to visualize four periodic flows: near wake behind an oscillating airfoil; edge tone sound generation; 2-D planar wall jet; and axisymmetric pulsed sonic jet. This visualization technique provides an effective means of studying quasi-periodic flows in real time. The image on the viewing screen is a spatial signal average of the coherent periodic motion rather than a single realization, the high speed motion of a quasi-periodic flow can be reconstructed by recording photographs of the flow at different fixed time delays in one cycle. The preliminary design and construction of a self synchronizing stroboscopic laser interferometer with a modified Mach-Zehnder optical system is also reported.

Multi-Layer SnSe Nanoflake Field-Effect Transistors with Low-Resistance Au Ohmic Contacts

NASA Astrophysics Data System (ADS)

Cho, Sang-Hyeok; Cho, Kwanghee; Park, No-Won; Park, Soonyong; Koh, Jung-Hyuk; Lee, Sang-Kwon

2017-05-01

We report p-type tin monoselenide (SnSe) single crystals, grown in double-sealed quartz ampoules using a modified Bridgman technique at 920 °C. X-ray powder diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX) measurements clearly confirm that the grown SnSe consists of single-crystal SnSe. Electrical transport of multi-layer SnSe nanoflakes, which were prepared by exfoliation from bulk single crystals, was conducted using back-gated field-effect transistor (FET) structures with Au and Ti contacts on SiO2/Si substrates, revealing that multi-layer SnSe nanoflakes exhibit p-type semiconductor characteristics owing to the Sn vacancies on the surfaces of SnSe nanoflakes. In addition, a strong carrier screening effect was observed in 70-90-nm-thick SnSe nanoflake FETs. Furthermore, the effect of the metal contacts to multi-layer SnSe nanoflake-based FETs is also discussed with two different metals, such as Ti/Au and Au contacts.

Pharmaceutical aspects of salt and cocrystal forms of APIs and characterization challenges.

PubMed

Cerreia Vioglio, Paolo; Chierotti, Michele R; Gobetto, Roberto

2017-08-01

In recent years many efforts have been devoted to the screening and the study of new solid-state forms of old active pharmaceutical ingredients (APIs) with salification or co-crystallization processes, thus modulating final properties without changing the pharmacological nature. Salts, hydrates/solvates, and cocrystals are the common solid-state forms employed. They offer the intriguing possibility of exploring different pharmaceutical properties for a single API in the quest of enhancing the final drug product. New synthetic strategies and advanced characterization techniques have been recently proposed in this hot topic for pharmaceutical companies. This paper reviews the recent progresses in the field particularly focusing on the characterization challenges encountered when the nature of the solid-state form must be determined. The aim of this article is to offer the state-of-the-art on this subject in order to develop new insights and to promote cooperative efforts in the fascinating field of API salt and cocrystal forms. Copyright © 2017 Elsevier B.V. All rights reserved.

imaging volcanos with gravity and muon tomography measurements

NASA Astrophysics Data System (ADS)

Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; Deroussi, Sébastien; Dufour, Fabrice; de Bremond d'Ars, Jean; Ianigro, Jean-Christophe; Gardien, Serge; Girerd, Claude

2015-04-01

Both muon tomography and gravimetry are geohysical methods that provide information on the density structure of the Earth's subsurface. Muon tomography measures the natural flux of cosmic muons and its attenuation produced by the screening effect of the rock mass to image. Gravimetry generally consists in measurements of the vertical component of the local gravity field. Both methods are linearly linked to density, but their spatial sensitivity is very different. Muon tomography essentially works like medical X-ray scan and integrates density information along elongated narrow conical volumes while gravimetry measurements are linked to density by a 3-dimensional integral encompassing the whole studied domain. We show that gravity data are almost useless to constrain the density structure in regions sampled by more than two muon tomography acquisitions. Interestingly the resolution in deeper regions not sampled by muon tomography is significantly improved by joining the two techniques. Examples taken from field experiments performed on La Soufrière of Guadeloupe volcano are discussed.

Using a geographic information system and scanning technology to create high-resolution land-use data sets

USGS Publications Warehouse

Harvey, Craig A.; Kolpin, Dana W.; Battaglin, William A.

1996-01-01

A geographic information system (GIS) procedure was developed to compile low-altitude aerial photography, digitized data, and land-use data from U.S. Department of Agriculture Consolidated Farm Service Agency (CFSA) offices into a high-resolution (approximately 5 meters) land-use GIS data set. The aerial photography consisted of 35-mm slides which were scanned into tagged information file format (TIFF) images. These TIFF images were then imported into the GIS where they were registered into a geographically referenced coordinate system. Boundaries between land use were delineated from these GIS data sets using on-screen digitizing techniques. Crop types were determined using information obtained from the U.S. Department of Agriculture CFSA offices. Crop information not supplied by the CFSA was attributed by manual classification procedures. Automated methods to provide delineation of the field boundaries and land-use classification were investigated. It was determined that using these data sources, automated methods were less efficient and accurate than manual methods of delineating field boundaries and classifying land use.

Evaluation of electrochemical, UV/VIS and Raman spectroelectrochemical detection of Naratriptan with screen-printed electrodes.

PubMed

Hernández, Carla Navarro; Martín-Yerga, Daniel; González-García, María Begoña; Hernández-Santos, David; Fanjul-Bolado, Pablo

2018-02-01

Naratriptan, active pharmaceutical ingredient with antimigraine activity was electrochemically detected in untreated screen-printed carbon electrodes (SPCEs). Cyclic voltammetry and differential pulse voltammetry were used to carry out quantitative analysis of this molecule (in a Britton-Robinson buffer solution at pH 3.0) through its irreversible oxidation (diffusion controlled) at a potential of +0.75V (vs. Ag pseudoreference electrode). Naratriptan oxidation product is an indole based dimer with a yellowish colour (maximum absorption at 320nm) so UV-VIS spectroelectrochemistry technique was used for the very first time as an in situ characterization and quantification technique for this molecule. A reflection configuration approach allowed its measurement over the untreated carbon based electrode. Finally, time resolved Raman Spectroelectrochemistry is used as a powerful technique to carry out qualitative and quantitative analysis of Naratriptan. Electrochemically treated silver screen-printed electrodes are shown as easy to use and cost-effective SERS substrates for the analysis of Naratriptan. Copyright © 2017 Elsevier B.V. All rights reserved.

NearSense - Advances Towards a Silicon-Based Terahertz Near-Field Imaging Sensor for Ex Vivo Breast Tumour Identification

NASA Astrophysics Data System (ADS)

Mavarani, Laven; Hillger, Philipp; Bücher, Thomas; Grzyb, Janusz; Pfeiffer, Ullrich R.; Cassar, Quentin; Al-Ibadi, Amel; Zimmer, Thomas; Guillet, Jean-Paul; Mounaix, Patrick; MacGrogan, Gaëtan

2018-03-01

Breast Cancer is one of the most frequently diagnosed cancer diseases worldwide, and the most common invasive tumour for women. As with all cancers, early detection plays a major role in reducing the mortality and morbidity rate. Currently, most breast cancers are detected due to clinical symptoms, or by screening mammography. The limitations of these techniques have resulted in research of alternative methods for imaging and detecting breast cancer. Apart from this, it is essential to define precise tumour margins during breast-conserving surgeries to reduce the re-excision rate. This study presents the advances in the development of a silicon-based THz sub-wavelength imager usable in life science applications, especially for tumour margin identification.

Drug screening in clinical or forensic toxicology: are there differences?

PubMed

Gerostamoulos, Dimitri; Beyer, Jochen

2010-09-01

Legal and medical practitioners need to remember that, with respect to drug analysis, there are two distinct disciplines in analytical toxicology concerned with human biological matrices, namely clinical and forensic toxicology. Both fields use similar analytical techniques designed to detect and quantify drugs, chemicals and poisons in fluids or tissues. In clinical toxicology, analytical results help to specify the appropriate treatment of a poisoned or intoxicated patient. In forensic toxicology, the results often play a vital role in determining the possible impairment or behavioural changes in an individual, or the contribution of drugs or poisons to death in a medico-legal investigation. This column provides an overview of the similarities and differences inherent in clinical and forensic toxicology.

Evaluation of Bulk Charging in Geostationary Transfer Orbit and Earth Escape Trajectories Using the Numit 1-D Charging Model

NASA Technical Reports Server (NTRS)

Minow, Joseph I.; Coffey, Victoria N.; Parker, Linda N.; Blackwell, William C., Jr.; Jun, Insoo; Garrett, Henry B.

2007-01-01

The NUMIT 1-dimensional bulk charging model is used as a screening to ol for evaluating time-dependent bulk internal or deep dielectric) ch arging of dielectrics exposed to penetrating electron environments. T he code is modified to accept time dependent electron flux time serie s along satellite orbits for the electron environment inputs instead of using the static electron flux environment input originally used b y the code and widely adopted in bulk charging models. Application of the screening technique ts demonstrated for three cases of spacecraf t exposure within the Earth's radiation belts including a geostationa ry transfer orbit and an Earth-Moon transit trajectory for a range of orbit inclinations. Electric fields and charge densities are compute d for dielectric materials with varying electrical properties exposed to relativistic electron environments along the orbits. Our objectiv e is to demonstrate a preliminary application of the time-dependent e nvironments input to the NUMIT code for evaluating charging risks to exposed dielectrics used on spacecraft when exposed to the Earth's ra diation belts. The results demonstrate that the NUMIT electric field values in GTO orbits with multiple encounters with the Earth's radiat ion belts are consistent with previous studies of charging in GTO orb its and that potential threat conditions for electrostatic discharge exist on lunar transit trajectories depending on the electrical proper ties of the materials exposed to the radiation environment.

Fizeau simultaneous phase-shifting interferometry based on extended source

NASA Astrophysics Data System (ADS)

Wang, Shanshan; Zhu, Qiudong; Hou, Yinlong; Cao, Zheng

2016-09-01

Coaxial Fizeau simultaneous phase-shifting interferometer plays an important role in many fields for its characteristics of long optical path, miniaturization, and elimination of reference surface high-frequency error. Based on the matching of coherence between extended source and interferometer, orthogonal polarization reference wave and measurement wave can be obtained by Fizeau interferometry with Michelson interferometer preposed. Through matching spatial coherence length between preposed interferometer and primary interferometer, high contrast interference fringes can be obtained and additional interference fringes can be eliminated. Thus, the problem of separation of measurement and reference surface in the common optical path Fizeau interferometer is solved. Numerical simulation and principle experiment is conducted to verify the feasibility of extended source interferometer. Simulation platform is established by using the communication technique of DDE (dynamic data exchange) to connect Zemax and Matlab. The modeling of the extended source interferometer is realized by using Zemax. Matlab codes are programmed to automatically rectify the field parameters of the optical system and conveniently calculate the visibility of interference fringes. Combined with the simulation, the experimental platform of the extended source interferometer is established. After experimental research on the influence law of scattering screen granularity to interference fringes, the granularity of scattering screen is determined. Based on the simulation platform and experimental platform, the impacts on phase measurement accuracy of the imaging system aberration and collimation system aberration of the interferometer are analyzed. Compared the visibility relation curves between experimental measurement and simulation result, the experimental result is in line with the theoretical result.

Factors affecting implementation of perinatal mental health screening in women of refugee background.

PubMed

Nithianandan, Nishani; Gibson-Helm, Melanie; McBride, Jacquie; Binny, Amanda; Gray, Kylie M; East, Christine; Boyle, Jacqueline A

2016-11-18

For women of refugee background, the increased risk of mental illness associated with pregnancy is compounded by pre- and post-settlement stressors. In Australia, antenatal screening for depression and anxiety symptoms using the Edinburgh Postnatal Depression Scale is recommended for all women. Despite this, screening is not routinely implemented and little is known about barriers and enablers to implementation for women of refugee background. Semi-structured interviews were conducted with a range of health professionals (n = 28: midwives, obstetricians, perinatal mental health and refugee health experts, interpreters) and women of refugee background (n = 9). Themes generated from thematic analysis were examined in relation to the Theoretical Domains Framework and Cultural Competence Conceptual Framework, followed by identification of effective behaviour change techniques to address the barriers and enablers identified by participants. These techniques formed the basis of recommendations to inform sustainable implementation of screening and referral. Almost all participants perceived perinatal mental health screening to be necessary and most recognised the importance of post-traumatic stress disorder (PTSD) screening. Barriers and enablers were identified and related to eight domains: knowledge, skills, professional roles, beliefs about capabilities and consequences, environmental context, social influences and behavioural regulation. This research clarifies how mental health screening may be integrated into routine antenatal care for women of refugee background, in order to improve provision of recommended care. These theory-informed recommendations include an inter-disciplinary approach, coordinating care within and across services, addition of PTSD screening, and effective communication with women.

Early detection of glaucoma by means of a novel 3D computer‐automated visual field test

PubMed Central

Nazemi, Paul P; Fink, Wolfgang; Sadun, Alfredo A; Francis, Brian; Minckler, Donald

2007-01-01

Purpose A recently devised 3D computer‐automated threshold Amsler grid test was used to identify early and distinctive defects in people with suspected glaucoma. Further, the location, shape and depth of these field defects were characterised. Finally, the visual fields were compared with those obtained by standard automated perimetry. Patients and methods Glaucoma suspects were defined as those having elevated intraocular pressure (>21 mm Hg) or cup‐to‐disc ratio of >0.5. 33 patients and 66 eyes with risk factors for glaucoma were examined. 15 patients and 23 eyes with no risk factors were tested as controls. The recently developed 3D computer‐automated threshold Amsler grid test was used. The test exhibits a grid on a computer screen at a preselected greyscale and angular resolution, and allows patients to trace those areas on the grid that are missing in their visual field using a touch screen. The 5‐minute test required that the patients repeatedly outline scotomas on a touch screen with varied displays of contrast while maintaining their gaze on a central fixation marker. A 3D depiction of the visual field defects was then obtained that was further characterised by the location, shape and depth of the scotomas. The exam was repeated three times per eye. The results were compared to Humphrey visual field tests (ie, achromatic standard or SITA standard 30‐2 or 24‐2). Results In this pilot study 79% of the eyes tested in the glaucoma‐suspect group repeatedly demonstrated visual field loss with the 3D perimetry. The 3D depictions of visual field loss associated with these risk factors were all characteristic of or compatible with glaucoma. 71% of the eyes demonstrated arcuate defects or a nasal step. Constricted visual fields were shown in 29% of the eyes. No visual field changes were detected in the control group. Conclusions The 3D computer‐automated threshold Amsler grid test may demonstrate visual field abnormalities characteristic of glaucoma in glaucoma suspects with normal achromatic Humphrey visual field testing. This test may be used as a screening tool for the early detection of glaucoma. PMID:17504855

A randomised trial of non-mydriatic ultra-wide field retinal imaging versus usual care to screen for diabetic eye disease: rationale and protocol for the Clearsight trial

PubMed Central

Mahon, Lewis W; Klar, Neil S; Schulz, David C; Gonder, John R; Hramiak, Irene M; Mahon, Jeffrey L

2017-01-01

Introduction Suboptimal screening for diabetic eye disease is a major cause of preventable vision loss. Screening barriers include mydriasis and the extra time patients need to attend dedicated eye screening appointments. In the Clearsight trial, we are testing whether screening by non-mydriatic ultra-wide field (NM UWF) imaging on the day patients attend their diabetes outpatient clinic visit improves detection of clinically important eye disease compared with usual screening. Methods and analysis Patients with diabetes due for a screening eye exam by the 2013 Canadian Diabetes Association (CDA) practice guidelines are being randomised to on-site screening by NM UWF imaging on the day of their clinic visit or to usual screening where, per CDA guidelines, they are encouraged to arrange an exam by an optometrist. The primary outcome is actionable eye disease (AED) based on a need for referral to ophthalmology and/or increased ocular surveillance. The primary analysis will use an intention-to-screen approach that compares the proportions of detected AED between on-site and usual screening groups under a superiority hypothesis in favour of on-site screening. With 740 randomised participants, the study will have 80% power to detect ≥5% absolute increase in the AED rate among on-site screening versus usual screening participants. This difference translates into a number-needed-to-screen by on-site screening of 20 to detect 1 additional person with AED. Ethics and dissemination The protocol was approved by the institutional review board of Western University. The findings of the trial will be disseminated directly to participants and through peer-reviewed publications and conference presentations. Trial registration number ClinicalTrials.Gov NCT02579837 (registered 16 October 2015). Protocol issue date 18 November 2015. PMID:28775182

Economic evaluation of orthoptic screening: results of a field study in 121 German kindergartens.

PubMed

König, Hans-Helmut; Barry, Jean-Cyriaque; Leidl, Reiner; Zrenner, Eberhart

2002-10-01

The purpose of this study was to analyze the cost-effectiveness of an orthoptic screening program in kindergarten children. An empiric cost-effectiveness analysis was conducted as part of a field study of orthoptic screening. Three-year-old children (n = 1180) in 121 German kindergartens were screened by orthoptists. The number of newly diagnosed cases of amblyopia and amblyogenic factors (target conditions) was used as the measure of effectiveness. The direct costs of orthoptic screening were calculated from a third-party-payer perspective based on comprehensive measurement of working hours and material costs. The average cost of a single orthoptic screening examination was 12.58 Euro. This amount consisted of labor costs (10.99 Euro) and costs of materials and traveling (1.60 Euro). With 9.9 children screened on average per kindergarten, average labor time was 279 minutes per kindergarten, or 28 minutes per child. It consisted of time for organization (46%), traveling (16%), preparing the examination site (10%), and the orthoptic examination itself (28%). The total cost of the screening program in all 121 kindergartens (including ophthalmic examination, if required) was 21,253 Euro. Twenty-three new cases of the target conditions were detected. The cost-effectiveness ratio was 924 Euro per detected case. Sensitivity analysis showed that the prevalence and the specificity of orthoptic screening had substantial influence on the cost-effectiveness ratio. The data on the cost-effectiveness of orthoptic screening in kindergarten may be used by such third-party payers as health insurance or public health services when deciding about organizing and financing preschool vision-screening programs.

Nonlinear AC susceptibility, surface and bulk shielding

NASA Astrophysics Data System (ADS)

van der Beek, C. J.; Indenbom, M. V.; D'Anna, G.; Benoit, W.

1996-02-01

We calculate the nonlinear AC response of a thin superconducting strip in perpendicular field, shielded by an edge current due to the geometrical barrier. A comparison with the results for infinite samples in parallel field, screened by a surface barrier, and with those for screening by a bulk current in the critical state, shows that the AC response due to a barrier has general features that are independent of geometry, and that are significantly different from those for screening by a bulk current in the critical state. By consequence, the nonlinear (global) AC susceptibility can be used to determine the origin of magnetic irreversibility. A comparison with experiments on a Bi 2Sr 2CaCu 2O 8+δ crystal shows that in this material, the low-frequency AC screening at high temperature is mainly due to the screening by an edge current, and that this is the unique source of the nonlinear magnetic response at temperatures above 40 K.

The clinical benefit and safety of current and future assisted reproductive technology.

PubMed

Brown, Rachel; Harper, Joyce

2012-08-01

Since the first birth by IVF was achieved in 1978, the techniques involved in assisted reproductive technology have grown at an enormous rate. However, new technology has rarely been robustly validated before clinical use and developing scientific understanding of the available techniques has done little to alter their use. Furthermore, there are inconsistencies in the available clinical studies and endpoints. The benefits of some technologies already established for routine use are currently dubious and there are clear ethical concerns with providing them to patients when their scientific basis is not clear. As the uptake of assisted reproductive technology increases and newer technologies continue to push the boundaries of science, it is important to consider the clinical benefits and safety of all assisted reproductive technologies. This review will discuss aspects of some of the more recent techniques, including sperm DNA-damage tests, intracytoplasmic morphologically selected sperm injection, amino acid and metabolomics profiling, preimplantation genetic screening and time-lapse imaging, and those that may have substantial impacts on the field of reproductive medicine in the future including artificial gametes, ovarian transplantation and gene therapy. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

[Application of molecular diagnostic techniques in precision medicine of personalized treatment for colorectal cancer].

PubMed

Fu, Ji; Lin, Guole

2016-01-01

Precision medicine is to customize the treatment options for individual patient based on the personal genome information. Colorectal cancer (CRC) is one of the most common cancer worldwide. Molecular heterogeneity of CRC, which includes the MSI phenotype, hypermutation phenotype, and their relationship with clinical preferences, is believed to be one of the main factors responsible for the considerable variability in treatment response. The development of powerful next-generation sequencing (NGS) technologies allows us to further understand the biological behavior of colorectal cancer, and to analyze the prognosis and chemotherapeutic drug reactions by molecular diagnostic techniques, which can guide the clinical treatment. This paper will introduce the new findings in this field. Meanwhile we integrate the new progress of key pathways including EGFR, RAS, PI3K/AKT and VEGF, and the experience in selective patients through associated molecular diagnostic screening who gain better efficacy after target therapy. The technique for detecting circulating tumor DNA (ctDNA) is introduced here as well, which can identify patients with high risk for recurrence, and demonstrate the risk of chemotherapy resistance. Mechanism of tumor drug resistance may be revealed by dynamic observation of gene alteration during treatment.

Electromigrative separation techniques in forensic science: combining selectivity, sensitivity, and robustness.

PubMed

Posch, Tjorben Nils; Pütz, Michael; Martin, Nathalie; Huhn, Carolin

2015-01-01

In this review we introduce the advantages and limitations of electromigrative separation techniques in forensic toxicology. We thus present a summary of illustrative studies and our own experience in the field together with established methods from the German Federal Criminal Police Office rather than a complete survey. We focus on the analytical aspects of analytes' physicochemical characteristics (e.g. polarity, stereoisomers) and analytical challenges including matrix tolerance, separation from compounds present in large excess, sample volumes, and orthogonality. For these aspects we want to reveal the specific advantages over more traditional methods. Both detailed studies and profiling and screening studies are taken into account. Care was taken to nearly exclusively document well-validated methods outstanding for the analytical challenge discussed. Special attention was paid to aspects exclusive to electromigrative separation techniques, including the use of the mobility axis, the potential for on-site instrumentation, and the capillary format for immunoassays. The review concludes with an introductory guide to method development for different separation modes, presenting typical buffer systems as starting points for different analyte classes. The objective of this review is to provide an orientation for users in separation science considering using capillary electrophoresis in their laboratory in the future.

Filling-enforced nonsymmorphic Kondo semimetals in two dimensions

NASA Astrophysics Data System (ADS)

Pixley, J. H.; Lee, SungBin; Brandom, B.; Parameswaran, S. A.

2017-08-01

We study the competition between Kondo screening and frustrated magnetism on the nonsymmorphic Shastry-Sutherland Kondo lattice at a filling of two conduction electrons per unit cell. This model is known to host a set of gapless partially Kondo screened phases intermediate between the Kondo-destroyed paramagnet and the heavy Fermi liquid. Based on crystal symmetries, we argue that (i) both the paramagnet and the heavy Fermi liquid are semimetals protected by a glide symmetry; and (ii) partial Kondo screening breaks the symmetry, removing this protection and allowing the partially Kondo screened phase to be deformed into a Kondo insulator via a Lifshitz transition. We confirm these results using large-N mean-field theory and then use nonperturbative arguments to derive a generalized Luttinger sum rule constraining the phase structure of two-dimensional nonsymmorphic Kondo lattices beyond the mean-field limit.

Dual-Screened Vertical Circulation Wells for Groundwater Lowering in Unconfined Aquifers.

PubMed

Jin, Yulan; Holzbecher, Ekkehard; Sauter, Martin

2016-01-01

A new type of vertical circulation well (VCW) is used for groundwater dewatering at construction sites. This type of VCW consists of an abstraction screen in the upper part and an injection screen in the lower part of a borehole, whereby drawdown is achieved without net withdrawal of groundwater from the aquifer. The objective of this study is to evaluate the operation of such wells including the identification of relevant factors and parameters based on field data of a test site and comprehensive numerical simulations. The numerical model is able to delineate the drawdown of groundwater table, defined as free-surface, by coupling the arbitrary Lagrangian-Eulerian algorithm with the groundwater flow equation. Model validation is achieved by comparing the field observations with the model results. Eventually, the influences of selected well operation and aquifer parameters on drawdown and on the groundwater flow field are investigated by means of parameter sensitivity analysis. The results show that the drawdown is proportional to the flow rate, inversely proportional to the aquifer conductivity, and almost independent of the aquifer anisotropy in the direct vicinity of the well. The position of the abstraction screen has a stronger effect on drawdown than the position of the injection screen. The streamline pattern depends strongly on the separation length of the screens and on the aquifer anisotropy, but not on the flow rate and the horizontal hydraulic conductivity. © 2015, National Ground Water Association.

Recruitment Techniques and Strategies in a Community-Based Colorectal Cancer Screening Study of Men and Women of African Ancestry.

PubMed

Davis, Stacy N; Govindaraju, Swapamthi; Jackson, Brittany; Williams, Kimberly R; Christy, Shannon M; Vadaparampil, Susan T; Quinn, Gwendolyn P; Shibata, David; Roetzheim, Richard; Meade, Cathy D; Gwede, Clement K

Recruiting ethnically diverse Black participants to an innovative, community-based research study to reduce colorectal cancer screening disparities requires multipronged recruitment techniques. This article describes active, passive, and snowball recruitment techniques, and challenges and lessons learned in recruiting a diverse sample of Black participants. For each of the three recruitment techniques, data were collected on strategies, enrollment efficiency (participants enrolled/participants evaluated), and reasons for ineligibility. Five hundred sixty individuals were evaluated, and 330 individuals were enrolled. Active recruitment yielded the highest number of enrolled participants, followed by passive and snowball. Snowball recruitment was the most efficient technique, with enrollment efficiency of 72.4%, followed by passive (58.1%) and active (55.7%) techniques. There were significant differences in gender, education, country of origin, health insurance, and having a regular physician by recruitment technique (p < .05). Multipronged recruitment techniques should be employed to increase reach, diversity, and study participation rates among Blacks. Although each recruitment technique had a variable enrollment efficiency, the use of multipronged recruitment techniques can lead to successful enrollment of diverse Blacks into cancer prevention and control interventions.

Screening and Assessment of Young Children.

ERIC Educational Resources Information Center

Friedlander, Bernard Z.

Most language development hazards in infancy and early childhood fall into the categories of auditory impairment, central integrative dysfunction, inadequate environmental support, and peripheral expressive impairment. Existing knowledge and techniques are inadequate to meet the screening and assessment problems of central integrative dysfunction,…