Hu, Yunzi; Daoud, Walid A.; Cheuk, Kevin Ka Leung; Lin, Carol Sze Ki
2016-01-01
Polycondensation and ring-opening polymerization are two important polymer synthesis methods. Poly(lactic acid), the most typical biodegradable polymer, has been researched extensively from 1900s. It is of significant importance to have an up-to-date review on the recent improvement in techniques for biodegradable polymers. This review takes poly(lactic acid) as the example to present newly developed polymer synthesis techniques on polycondensation and ring-opening polymerization reported in the recent decade (2005–2015) on the basis of industrial technique modifications and advanced laboratory research. Different polymerization methods, including various solvents, heating programs, reaction apparatus and catalyst systems, are summarized and compared with the current industrial production situation. Newly developed modification techniques for polymer properties improvement are also discussed based on the case of poly(lactic acid). PMID:28773260
Hot-wire anemometry in hypersonic helium flow
NASA Technical Reports Server (NTRS)
Wagner, R. D.; Weinstein, L. M.
1974-01-01
Hot-wire anemometry techniques are described that have been developed and used for hypersonic-helium-flow studies. The short run time available dictated certain innovations in applying conventional hot-wire techniques. Some examples are given to show the application of the techniques used. Modifications to conventional equipment are described, including probe modifications and probe heating controls.
Simultaneous F 0-F 1 modifications of Arabic for the improvement of natural-sounding
NASA Astrophysics Data System (ADS)
Ykhlef, F.; Bensebti, M.
2013-03-01
Pitch (F 0) modification is one of the most important problems in the area of speech synthesis. Several techniques have been developed in the literature to achieve this goal. The main restrictions of these techniques are in the modification range and the synthesised speech quality, intelligibility and naturalness. The control of formants in a spoken language can significantly improve the naturalness of the synthesised speech. This improvement is mainly dependent on the control of the first formant (F 1). Inspired by this observation, this article proposes a new approach that modifies both F 0 and F 1 of Arabic voiced sounds in order to improve the naturalness of the pitch shifted speech. The developed strategy takes a parallel processing approach, in which the analysis segments are decomposed into sub-bands in the wavelet domain, modified in the desired sub-band by using a resampling technique and reconstructed without affecting the remained sub-bands. Pitch marking and voicing detection are performed in the frequency decomposition step based on the comparison of the multi-level approximation and detail signals. The performance of the proposed technique is evaluated by listening tests and compared to the pitch synchronous overlap and add (PSOLA) technique in the third approximation level. Experimental results have shown that the manipulation in the wavelet domain of F 0 in conjunction with F 1 guarantees natural-sounding of the synthesised speech compared to the classical pitch modification technique. This improvement was appropriate for high pitch modifications.
NASA Astrophysics Data System (ADS)
Urbaniak, Daniel J.
2004-11-01
In the research reported here, the surface modification of medical grade poly(dimethyl siloxane), polyetherurethane, and stainless steel through gamma-radiation grafting of hydrophilic polymers was investigated. Emphasis was placed on developing improved and simplified surface modification methods that produce more stable and more bioacceptible hydrophilic graft surfaces. As a result of this research, new surface modification techniques were developed that yield significantly improved surface stability unachievable using previous surface modification techniques. The surface modification of poly(dimethyl siloxane) with hydrophilic polymers was carried out using gamma radiation initiated graft polymerization. The addition of alkali metal hydroxides afforded a unique way to enhance the grafting of N-vinyl-2 pyrrolidone, dimethylacryamide, 2-methacryloyloxyethyl phosphoryl choline, N,N-dimethyl-N-(methacryloyloxyethyl)-N-(3-sulfopropyl)-ammonium-betaine, N,N-dimethyl-N-(methacrylamidopropyl)-N-(3-sulfopropyl)-ammonium-betaine, and copolymers thereof to silicones. Ethanolamine was found to further enhance the grafting of some hydrophilic polymers to silicone. The resulting hydrophilic surface grafts were resistant to hydrophobic surface rearrangement. This process overcomes previous problems inherent in silicone surface modification. The technique was also found to moderately enhance the grafting of hydrophilic monomers to polyetherurethane and to 316-L stainless steel. The surface modification of 316-L stainless steel was further enhanced by treating the substrates with a chromium III methacrylate bonding agent prior to irradiation. The coatings were evaluated for their potential use as depots for delivering therapeutic agents. The release of ofloxacin from surface-modified poly(dimethyl siloxane) and dexamethasone from surface-modified 316-L stainless steel was evaluated by in-vitro experiments. Therapeutic levels of drugs were released from surface-modified specimens via a burst effect. Improved surface characterization methods were another aspect of this research. New nanomechanical testing techniques were developed and used to evaluate the viscoelastic surface mechanical properties of low modulus surface-modified specimens. Dynamic nanoindentation characterization techniques were designed to measure the storage modulus and loss modulus of compliant viscoelastic substrate surfaces. The results of these experiments were compared with modulus data obtained by conventional dynamic mechanical spectroscopy. Nanoscratch testing methods were also developed that qualitatively compared the abrasion resistance of surface-modified substrates. (Abstract shortened by UMI.)
LISA Technology Development at GSFC
NASA Technical Reports Server (NTRS)
Thorpe, James Ira; McWilliams, S.; Baker, J.
2008-01-01
The prime focus of LISA technology development efforts at NASA/GSFC has been in LISA interferometry, specifically in the area of laser frequency noise mitigation. Laser frequency noise is addressed through a combination of stabilization and common-mode rejection. Current plans call for two stages of stabilization, pre-stabilization to a local frequency reference and further stabilization using the constellation as a frequency reference. In order for these techniques to be used simultaneously, the pre-stabilization step must provide an adjustable frequency offset. Here, we report on a modification to the standard modulation/demodulation techniques used to stabilize to optical cavities that generates a frequency-tunable reference from a fixed-length cavity. This technique requires no modifications to the cavity itself and only minor modifications to the components. The measured noise performance and dynamic range of the laboratory prototype meets the LISA requirements.
NASA Technical Reports Server (NTRS)
1972-01-01
Developments by the aerospace industry in seals and sealing techniques are announced for possible use in other areas. The announcements presented are grouped as: sealing techniques for cryogenic fluids, high pressure applications, and modification for improved performance.
Surface Characterization Techniques: An Overview
NASA Technical Reports Server (NTRS)
Miyoshi, Kazuhisa
2002-01-01
To understand the benefits that surface modifications provide, and ultimately to devise better ones, it is necessary to study the physical, mechanical, and chemical changes they cause. This chapter surveys classical and leading-edge developments in surface structure and property characterization methodologies. The primary emphases are on the use of these techniques as they relate to surface modifications, thin films and coatings, and tribological engineering surfaces and on the implications rather than the instrumentation.
ERIC Educational Resources Information Center
Schneider, Marlene; Robin, Arthur
This manual describes the Turtle Technique which was developed to help children with behavior problems control their own disruptive behavior. The technique differs from other behavior modification techniques in that it is based upon self-control rather than external control of disruptive behavior. The Turtle Technique first teaches the child how…
Selected photographic techniques, a compilation
NASA Technical Reports Server (NTRS)
1971-01-01
A selection has been made of methods, devices, and techniques developed in the field of photography during implementation of space and nuclear research projects. These items include many adaptations, variations, and modifications to standard hardware and practice, and should prove interesting to both amateur and professional photographers and photographic technicians. This compilation is divided into two sections. The first section presents techniques and devices that have been found useful in making photolab work simpler, more productive, and higher in quality. Section two deals with modifications to and special applications for existing photographic equipment.
LISA Beyond Einstein: From the Big Bang to Black Holes. LISA Technology Development at GSFC
NASA Technical Reports Server (NTRS)
Thorpe, James Ira
2008-01-01
This viewgraph presentation reviews the work that has been ongoing at the Goddard Space Flight Center (GSFC) in the development of the technology to be used in the Laser Interferometer Space Antenna (LISA) spacecrafts. The prime focus of LISA technology development efforts at NASA/GSFC has been in LISA interferometry. Specifically efforts have been made in the area of laser frequency noise mitigation. Laser frequency noise is addressed through a combination of stabilization and common-mode rejection. Current plans call for two stages of stabilization, pre-stabilization to a local frequency reference and further stabilization using the constellation as a frequency reference. In order for these techniques to be used simultaneously, the pre-stabilization step must provide an adjustable frequency offset. This presentation reports on a modification to the standard modulation/demodulation technique used to stabilize to optical cavities that generates a frequency-tunable reference from a fixed length cavity. This technique requires no modifications to the cavity itself and only minor modifications to the components. The measured noise performance and dynamic range of the laboratory prototype meet the LISA requirements.
PERSONNEL TRAINING AND DEVELOPMENT.
skills training, supervisory training, training for disadvantaged workers, and management development. It begins by discussing recent developments...and techniques of behavior modification. The most recent developments in training techniques are outlined. Methods for training disadvantaged ...of training and development outcomes are reviewed. The bulk of the empirical literature is concentrated in three areas: laboratory education, programmed instruction, and training the disadvantaged . (Author)
An overview of biofunctionalization of metals in Japan
Hanawa, Takao
2009-01-01
Surface modification is an important and predominant technique for obtaining biofunction and biocompatibility in metals for biomedical use. The surface modification technique is a process that changes the surface composition, structure and morphology of a material, leaving the bulk mechanical properties intact. A tremendous number of surface modification techniques using dry and wet processes to improve the hard tissue compatibility of titanium have been developed. Some are now commercially available. Most of these processes have been developed by Japanese institutions since the 1990s. A second approach is the immobilization of biofunctional molecules to the metal surface to control the adsorption of proteins and adhesion of cells, platelets and bacteria. The immobilization of poly(ethylene glycol) to a metal surface with electrodeposition and its effect on biofunction are reviewed. The creation of a metal–polymer composite is another way to obtain metal-based biofunctional materials. The relationship between the shear bonding strength and the chemical structure at the bonding interface of a Ti-segmentated polyurethane composite through a silane coupling agent is explained. PMID:19158014
Efficient computational nonlinear dynamic analysis using modal modification response technique
NASA Astrophysics Data System (ADS)
Marinone, Timothy; Avitabile, Peter; Foley, Jason; Wolfson, Janet
2012-08-01
Generally, structural systems contain nonlinear characteristics in many cases. These nonlinear systems require significant computational resources for solution of the equations of motion. Much of the model, however, is linear where the nonlinearity results from discrete local elements connecting different components together. Using a component mode synthesis approach, a nonlinear model can be developed by interconnecting these linear components with highly nonlinear connection elements. The approach presented in this paper, the Modal Modification Response Technique (MMRT), is a very efficient technique that has been created to address this specific class of nonlinear problem. By utilizing a Structural Dynamics Modification (SDM) approach in conjunction with mode superposition, a significantly smaller set of matrices are required for use in the direct integration of the equations of motion. The approach will be compared to traditional analytical approaches to make evident the usefulness of the technique for a variety of test cases.
Lin, Ying-Ting
2013-04-30
A tandem technique of hard equipment is often used for the chemical analysis of a single cell to first isolate and then detect the wanted identities. The first part is the separation of wanted chemicals from the bulk of a cell; the second part is the actual detection of the important identities. To identify the key structural modifications around ligand binding, the present study aims to develop a counterpart of tandem technique for cheminformatics. A statistical regression and its outliers act as a computational technique for separation. A PPARγ (peroxisome proliferator-activated receptor gamma) agonist cellular system was subjected to such an investigation. Results show that this tandem regression-outlier analysis, or the prioritization of the context equations tagged with features of the outliers, is an effective regression technique of cheminformatics to detect key structural modifications, as well as their tendency of impact to ligand binding. The key structural modifications around ligand binding are effectively extracted or characterized out of cellular reactions. This is because molecular binding is the paramount factor in such ligand cellular system and key structural modifications around ligand binding are expected to create outliers. Therefore, such outliers can be captured by this tandem regression-outlier analysis.
Applying usability testing techniques to improve a health promotion website.
Hinchliffe, Anetta; Mummery, W Kerry
2008-04-01
Use of the Internet for health promotion is increasing; however, the lack of published research regarding website usability suggests that health promotion websites are being developed without consultation with their users or formal evaluation. This study conducted usability testing of an existing health promotion website to inform modifications and to identify common usability themes that should be addressed by organisations developing or maintaining a health promotion website. A combination of qualitative and quantitative techniques were implemented during the usability testing sessions to gather data from users while completing tasks on the website. Techniques included performance measures (time taken), direct observation (participant observation) and subjective user preferences (questionnaire and interview). Improvements to the website were measured in terms of reduced problems reported, reduced time taken to complete tasks and increased subjective reports. Seven usability themes emerged from the data: design, feedback, format, instructions, navigation, terminology and learnability. This study demonstrates the application of usability testing to the design and modification of a health promotion website and illustrates the areas or themes that can be used as a framework for testing and modification.
Single-cell epigenomics: techniques and emerging applications.
Schwartzman, Omer; Tanay, Amos
2015-12-01
Epigenomics is the study of the physical modifications, associations and conformations of genomic DNA sequences, with the aim of linking these with epigenetic memory, cellular identity and tissue-specific functions. While current techniques in the field are characterizing the average epigenomic features across large cell ensembles, the increasing interest in the epigenetics within complex and heterogeneous tissues is driving the development of single-cell epigenomics. We review emerging single-cell methods for capturing DNA methylation, chromatin accessibility, histone modifications, chromosome conformation and replication dynamics. Together, these techniques are rapidly becoming a powerful tool in studies of cellular plasticity and diversity, as seen in stem cells and cancer.
High-resolution studies of the HF ionospheric modification interaction region
NASA Technical Reports Server (NTRS)
Duncan, L. M.; Sheerin, J. P.
1985-01-01
The use of the pulse edge analysis technique to explain ionospheric modifications caused by high-power HF radio waves is discussed. The technique, implemented at the Arecibo Observatory, uses long radar pulses and very rapid data sampling. A comparison of the pulse leading and trailing edge characteristics is obtained and the comparison is used to estimate the relative changes in the interaction region height and layer width; an example utilizing this technique is provided. Main plasma line overshoot and miniovershoot were studied from the pulse edge observations; the observations at various HF pulsings and radar resolutions are graphically presented. From the pulse edge data the development and the occurrence of main plasma line overshoot and miniovershoot are explained. The theories of soliton formation and collapse, wave ducting, profile modification, and parametric instabilities are examined as a means of explaining main plasma line overshoots and miniovershoots.
Huang, Junfeng; Wang, Fangjun; Ye, Mingliang; Zou, Hanfa
2014-11-06
Comprehensive analysis of the post-translational modifications (PTMs) on proteins at proteome level is crucial to elucidate the regulatory mechanisms of various biological processes. In the past decades, thanks to the development of specific PTM enrichment techniques and efficient multidimensional liquid chromatography (LC) separation strategy, the identification of protein PTMs have made tremendous progress. A huge number of modification sites for some major protein PTMs have been identified by proteomics analysis. In this review, we first introduced the recent progresses of PTM enrichment methods for the analysis of several major PTMs including phosphorylation, glycosylation, ubiquitination, acetylation, methylation, and oxidation/reduction status. We then briefly summarized the challenges for PTM enrichment. Finally, we introduced the fractionation and separation techniques for efficient separation of PTM peptides in large-scale PTM analysis. Copyright © 2014 Elsevier B.V. All rights reserved.
Micro- and nanoscale devices for the investigation of epigenetics and chromatin dynamics
NASA Astrophysics Data System (ADS)
Aguilar, Carlos A.; Craighead, Harold G.
2013-10-01
Deoxyribonucleic acid (DNA) is the blueprint on which life is based and transmitted, but the way in which chromatin -- a dynamic complex of nucleic acids and proteins -- is packaged and behaves in the cellular nucleus has only begun to be investigated. Epigenetic modifications sit 'on top of' the genome and affect how DNA is compacted into chromatin and transcribed into ribonucleic acid (RNA). The packaging and modifications around the genome have been shown to exert significant influence on cellular behaviour and, in turn, human development and disease. However, conventional techniques for studying epigenetic or conformational modifications of chromosomes have inherent limitations and, therefore, new methods based on micro- and nanoscale devices have been sought. Here, we review the development of these devices and explore their use in the study of DNA modifications, chromatin modifications and higher-order chromatin structures.
Application of a system modification technique to dynamic tuning of a spinning rotor blade
NASA Technical Reports Server (NTRS)
Spain, C. V.
1987-01-01
An important consideration in the development of modern helicopters is the vibratory response of the main rotor blade. One way to minimize vibration levels is to ensure that natural frequencies of the spinning main rotor blade are well removed from integer multiples of the rotor speed. A technique for dynamically tuning a finite-element model of a rotor blade to accomplish that end is demonstrated. A brief overview is given of the general purpose finite element system known as Engineering Analysis Language (EAL) which was used in this work. A description of the EAL System Modification (SM) processor is then given along with an explanation of special algorithms developed to be used in conjunction with SM. Finally, this technique is demonstrated by dynamically tuning a model of an advanced composite rotor blade.
NASA Technical Reports Server (NTRS)
Colwell, R. N. (Principal Investigator); Hay, C. M.; Thomas, R. W.; Benson, A. S.
1976-01-01
The progress of research conducted in support of the Large Area Crop Inventory Experiment (LACIE) is documented. Specific tasks include (1) evaluation of the static stratification procedure and modification of that procedure if warranted, and (2) the development of alternative photointerpretative techniques to the present LACIE procedures for the identification and selection of training fields (areas).
Meter shop equipment, techniques, and operation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Smith, R.F.
1995-12-01
The development of new equipment inevitably results in new techniques and operational procedures to be implemented. Innovative techniques can result in operational changes and the development of new equipment. An operational modification opens the door for the development of new ideas, new equipment, and new techniques. This constant cycle of change promotes a continuous series of economic evaluations and decisions. Equipment and technological changes in measuring natural gas have resulted in modifications from past practices. The changes underway today will influence the way we plan and budget for the future, and, most notably, will change the way we repair gasmore » meters. The meter shop of today will need to look at the way that these changes will become available and how they will help efforts in reducing costs and increasing productivity. For instance, the standard three- and four-chambered diaphragm gas meter design has not been significantly changed in the past few decades aside from having heavy, cast iron bodies changed to lightweight aluminum bodies and utilizing a few plastic parts. But changes have been made, and more are on the threshold.« less
Mechanisms of behavior modification in clinical behavioral medicine in China.
Yang, Zhiyin; Su, Zhonghua; Ji, Feng; Zhu, Min; Bai, Bo
2014-08-01
Behavior modification, as the core of clinical behavioral medicine, is often used in clinical settings. We seek to summarize behavior modification techniques that are commonly used in clinical practice of behavioral medicine in China and discuss possible biobehavioral mechanisms. We reviewed common behavior modification techniques in clinical settings in China, and we reviewed studies that explored possible biobehavioral mechanisms. Commonly used clinical approaches of behavior modification in China include behavior therapy, cognitive therapy, cognitive-behavioral therapy, health education, behavior management, behavioral relaxation training, stress management intervention, desensitization therapy, biofeedback therapy, and music therapy. These techniques have been applied in the clinical treatment of a variety of diseases, such as chronic diseases, psychosomatic diseases, and psychological disorders. The biobehavioral mechanisms of these techniques involve the autonomic nervous system, neuroendocrine system, neurobiochemistry, and neuroplasticity. Behavior modification techniques are commonly used in the treatment of a variety of somatic and psychological disorders in China. Multiple biobehavioral mechanisms are involved in successful behavior modification.
Monitoring Prepregs As They Cure
NASA Technical Reports Server (NTRS)
Young, P. R.; Gleason, J. R.; Chang, A. C.
1986-01-01
Quality IR spectra obtained in dynamic heating environment. New technique obtains quality infrared spectra on graphite-fiber-reinforced, polymeric-matrix-resin prepregs as they cure. Technique resulted from modification of diffuse reflectance/Fourier transform infrared (DR/FTIR) technique previously used to analyze environmentally exposed cured graphite composites. Technique contribute to better understanding of prepreg chemistry/temperature relationships and development of more efficient processing cycles for advanced materials.
Borecka, A; Gawor, J
2008-06-01
A modification of gDNA extraction was developed for the polymerase chain reaction (PCR) technique, intended for the detection and differentiation of Toxocara spp. eggs in soil or sediments. Sand samples from sandpits confirmed as being contaminated with Toxocara spp. eggs by the flotation technique were analysed by PCR. The use of proteinase K made it possible to obtain genomic DNA from the sample without needing to isolate eggs using flotation or to inactivate PCR inhibitors present in the sand. Specific primers in the PCR reaction allowed discrimination between T. canis and T. cati eggs. The modification simplified the procedure, thanks to eliminating the step of gDNA isolation from eggs, which is both laborious and difficult.
Implementation issues in source coding
NASA Technical Reports Server (NTRS)
Sayood, Khalid; Chen, Yun-Chung; Hadenfeldt, A. C.
1989-01-01
An edge preserving image coding scheme which can be operated in both a lossy and a lossless manner was developed. The technique is an extension of the lossless encoding algorithm developed for the Mars observer spectral data. It can also be viewed as a modification of the DPCM algorithm. A packet video simulator was also developed from an existing modified packet network simulator. The coding scheme for this system is a modification of the mixture block coding (MBC) scheme described in the last report. Coding algorithms for packet video were also investigated.
Is cepstrum averaging applicable to circularly polarized electric-field data?
NASA Astrophysics Data System (ADS)
Tunnell, T.
1990-04-01
In FY 1988 a cepstrum averaging technique was developed to eliminate the ground reflections from charged particle beam (CPB) electromagnetic pulse (EMP) data. The work was done for the Los Alamos National Laboratory Project DEWPOINT at SST-7. The technique averages the cepstra of horizontally and vertically polarized electric field data (i.e., linearly polarized electric field data). This cepstrum averaging technique was programmed into the FORTRAN codes CEP and CEPSIM. Steve Knox, the principal investigator for Project DEWPOINT, asked the authors to determine if the cepstrum averaging technique could be applied to circularly polarized electric field data. The answer is, Yes, but some modifications may be necessary. There are two aspects to this answer that we need to address, namely, the Yes and the modifications. First, regarding the Yes, the technique is applicable to elliptically polarized electric field data in general: circular polarization is a special case of elliptical polarization. Secondly, regarding the modifications, greater care may be required in computing the phase in the calculation of the complex logarithm. The calculation of the complex logarithm is the most critical step in cepstrum-based analysis. This memorandum documents these findings.
Parameter Estimation for a Hybrid Adaptive Flight Controller
NASA Technical Reports Server (NTRS)
Campbell, Stefan F.; Nguyen, Nhan T.; Kaneshige, John; Krishnakumar, Kalmanje
2009-01-01
This paper expands on the hybrid control architecture developed at the NASA Ames Research Center by addressing issues related to indirect adaptation using the recursive least squares (RLS) algorithm. Specifically, the hybrid control architecture is an adaptive flight controller that features both direct and indirect adaptation techniques. This paper will focus almost exclusively on the modifications necessary to achieve quality indirect adaptive control. Additionally this paper will present results that, using a full non -linear aircraft model, demonstrate the effectiveness of the hybrid control architecture given drastic changes in an aircraft s dynamics. Throughout the development of this topic, a thorough discussion of the RLS algorithm as a system identification technique will be provided along with results from seven well-known modifications to the popular RLS algorithm.
Microneedles as the technique of drug delivery enhancement in diverse organs and tissues.
Rzhevskiy, Alexey S; Singh, Thakur Raghu Raj; Donnelly, Ryan F; Anissimov, Yuri G
2018-01-28
Microneedles is the technique of drug delivery enhancement, which was primarily designed for facilitating percutaneous drug delivery. Started from the development of simple solid microneedles, providing microporation of stratum corneum and therefore enhancement of topical drug delivery, for two decades the technique has progressed in various modifications such as hollow, coated, dissolving and hydrogel forming microneedles. In their turn, the modifications have resulted in new mechanisms of drug delivery enhancement and followed by the expansion of applicability range in terms of targeted tissues and organs. Thus, in addition to percutaneous drug delivery, microneedles have been considered as an efficient technique facilitating ocular, oral mucosal, gastrointestinal, ungual and vaginal drug administration. It is anticipated that the technique of microneedle-assisted drug delivery will soon become relevant for majority of organs and tissues. Copyright © 2017 Elsevier B.V. All rights reserved.
Evaluating Groups for Training Parents in Child Management.
ERIC Educational Resources Information Center
Aitchison, Robert A.; Liberman, Robert Paul
The Oxnard (California) Community Mental Health Center reports on evaluation of efforts to train parents in child management skills using behavior modification techniques. Rigorous training procedures, curriculum, and evaluation techniques have been developed over the past two years. Twenty groups of 3-15 parents have received training in behavior…
ERIC Educational Resources Information Center
Maurye, Praveen; Basu, Arpita; Biswas, Jayanta Kumar; Bandyopadhyay, Tapas Kumar; Naskar, Malay
2018-01-01
Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These ever-growing advancements in the basic laboratory equipments lead to emergence of many expensive, complex, and tricky…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sakudo, N.; Ikenaga, N.; Ikeda, F.
2011-01-07
Dry sterilization of polymeric material is developed. The technique utilizes the plasma-based ion implantation which is same as for surface modification of polymers. Experimental data for sterilization are obtained by using spores of Bacillus subtilis as samples. On the other hand we previously showed that the surface modification enhanced the gas barrier characteristics of plastic bottles. Comparing the implantation conditions for the sterilization experiment with those for the surface modification, we find that both sterilization and surface modification are simultaneously performed in a certain range of implantation conditions. This implies that the present bottling system for plastic vessels will bemore » simplified and streamlined by excluding the toxic peroxide water that has been used in the traditional sterilization processes.« less
Ng, K H; Peh, W C G
2010-02-01
A technical note is a short article giving a brief description of a specific development, technique or procedure, or it may describe a modification of an existing technique, procedure or device applicable to medicine. The technique, procedure or device described should have practical value and should contribute to clinical diagnosis or management. It could also present a software tool, or an experimental or computational method. Technical notes are variously referred to as technical innovations or technical developments. The main criteria for publication will be the novelty of concepts involved, the validity of the technique and its potential for clinical applications.
Micro- and nanoscale devices for investigation of epigenetics and chromatin dynamics
2014-01-01
DNA is the blueprint upon which life is based and transmitted, yet the manner in which chromatin, the dynamic complex of nucleic acids and proteins, is packaged and behaves within the cellular nucleus has only begun to be investigated. The packaging and modifications around the genome have been shown to exert significant influence on cellular behaviour and in turn, human development and disease. However, conventional techniques for studying epigenetic or conformational modifications of chromosomes have inherent limitations, and therefore, new methods based on micro- and nanoscale devices have been sought. Here, we review the development of these devices and explore their use in the study of DNA and chromatin modifications and higher order chromatin structure. PMID:24091454
Tanahashi, Mitsuru
2010-01-01
Many attempts have been made to fabricate various types of inorganic nanoparticle-filled polymers (filler/polymer nanocomposites) by a mechanical or chemical approach. However, these approaches require modification of the nanofiller surfaces and/or complicated polymerization reactions, making them unsuitable for industrial-scale production of the nanocomposites. The author and coworkers have proposed a simple melt-compounding method for the fabrication of silica/polymer nanocomposites, wherein silica nanoparticles without surface modification were dispersed through the breakdown of loose agglomerates of colloidal nano-silica spheres in a kneaded polymer melt. This review aims to discuss experimental techniques of the proposed method and its advantages over other developed methods.
Nanotubular surface modification of metallic implants via electrochemical anodization technique.
Wang, Lu-Ning; Jin, Ming; Zheng, Yudong; Guan, Yueping; Lu, Xin; Luo, Jing-Li
2014-01-01
Due to increased awareness and interest in the biomedical implant field as a result of an aging population, research in the field of implantable devices has grown rapidly in the last few decades. Among the biomedical implants, metallic implant materials have been widely used to replace disordered bony tissues in orthopedic and orthodontic surgeries. The clinical success of implants is closely related to their early osseointegration (ie, the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant), which relies heavily on the surface condition of the implant. Electrochemical techniques for modifying biomedical implants are relatively simple, cost-effective, and appropriate for implants with complex shapes. Recently, metal oxide nanotubular arrays via electrochemical anodization have become an attractive technique to build up on metallic implants to enhance the biocompatibility and bioactivity. This article will thoroughly review the relevance of electrochemical anodization techniques for the modification of metallic implant surfaces in nanoscale, and cover the electrochemical anodization techniques used in the development of the types of nanotubular/nanoporous modification achievable via electrochemical approaches, which hold tremendous potential for bio-implant applications. In vitro and in vivo studies using metallic oxide nanotubes are also presented, revealing the potential of nanotubes in biomedical applications. Finally, an outlook of future growth of research in metallic oxide nanotubular arrays is provided. This article will therefore provide researchers with an in-depth understanding of electrochemical anodization modification and provide guidance regarding the design and tuning of new materials to achieve a desired performance and reliable biocompatibility.
Nanotubular surface modification of metallic implants via electrochemical anodization technique
Wang, Lu-Ning; Jin, Ming; Zheng, Yudong; Guan, Yueping; Lu, Xin; Luo, Jing-Li
2014-01-01
Due to increased awareness and interest in the biomedical implant field as a result of an aging population, research in the field of implantable devices has grown rapidly in the last few decades. Among the biomedical implants, metallic implant materials have been widely used to replace disordered bony tissues in orthopedic and orthodontic surgeries. The clinical success of implants is closely related to their early osseointegration (ie, the direct structural and functional connection between living bone and the surface of a load-bearing artificial implant), which relies heavily on the surface condition of the implant. Electrochemical techniques for modifying biomedical implants are relatively simple, cost-effective, and appropriate for implants with complex shapes. Recently, metal oxide nanotubular arrays via electrochemical anodization have become an attractive technique to build up on metallic implants to enhance the biocompatibility and bioactivity. This article will thoroughly review the relevance of electrochemical anodization techniques for the modification of metallic implant surfaces in nanoscale, and cover the electrochemical anodization techniques used in the development of the types of nanotubular/nanoporous modification achievable via electrochemical approaches, which hold tremendous potential for bio-implant applications. In vitro and in vivo studies using metallic oxide nanotubes are also presented, revealing the potential of nanotubes in biomedical applications. Finally, an outlook of future growth of research in metallic oxide nanotubular arrays is provided. This article will therefore provide researchers with an in-depth understanding of electrochemical anodization modification and provide guidance regarding the design and tuning of new materials to achieve a desired performance and reliable biocompatibility. PMID:25258532
Economou, Anastasios
2018-01-01
This work reviews the field of screen-printed electrodes (SPEs) modified with “green” metals for electrochemical stripping analysis of toxic elements. Electrochemical stripping analysis has been established as a useful trace analysis technique offering many advantages compared to competing optical techniques. Although mercury has been the preferred electrode material for stripping analysis, the toxicity of mercury and the associated legal requirements in its use and disposal have prompted research towards the development of “green” metals as alternative electrode materials. When combined with the screen-printing technology, such environment-friendly metals can lead to disposable sensors for trace metal analysis with excellent operational characteristics. This review focuses on SPEs modified with Au, Bi, Sb, and Sn for stripping analysis of toxic elements. Different modification approaches (electroplating, bulk modification, use of metal precursors, microengineering techniques) are considered and representative applications are described. A developing related field, namely biosensing based on stripping analysis of metallic nanoprobe labels, is also briefly mentioned. PMID:29596391
Economou, Anastasios
2018-03-29
This work reviews the field of screen-printed electrodes (SPEs) modified with "green" metals for electrochemical stripping analysis of toxic elements. Electrochemical stripping analysis has been established as a useful trace analysis technique offering many advantages compared to competing optical techniques. Although mercury has been the preferred electrode material for stripping analysis, the toxicity of mercury and the associated legal requirements in its use and disposal have prompted research towards the development of "green" metals as alternative electrode materials. When combined with the screen-printing technology, such environment-friendly metals can lead to disposable sensors for trace metal analysis with excellent operational characteristics. This review focuses on SPEs modified with Au, Bi, Sb, and Sn for stripping analysis of toxic elements. Different modification approaches (electroplating, bulk modification, use of metal precursors, microengineering techniques) are considered and representative applications are described. A developing related field, namely biosensing based on stripping analysis of metallic nanoprobe labels, is also briefly mentioned.
A data compression technique for synthetic aperture radar images
NASA Technical Reports Server (NTRS)
Frost, V. S.; Minden, G. J.
1986-01-01
A data compression technique is developed for synthetic aperture radar (SAR) imagery. The technique is based on an SAR image model and is designed to preserve the local statistics in the image by an adaptive variable rate modification of block truncation coding (BTC). A data rate of approximately 1.6 bit/pixel is achieved with the technique while maintaining the image quality and cultural (pointlike) targets. The algorithm requires no large data storage and is computationally simple.
NASA Technical Reports Server (NTRS)
Colwell, R. N. (Principal Investigator)
1977-01-01
The results and progress of work conducted in support of the Large Area Crop Inventory Experiment (LACIE) are documented. Research was conducted for two tasks. These tasks include: (1) evaluation of the UCB static stratification procedure and modification of that procedure if warranted; and (2) the development of alternative photointerpretive techniques to the present LACIE procedure for the identification and selection of training areas for machine-processing of LACIE segments.
Espiritu, Michael J; Cabalteja, Chino C; Sugai, Christopher K; Bingham, Jon-Paul
2014-01-01
Bioactive peptides from Conus venom contain a natural abundance of post-translational modifications that affect their chemical diversity, structural stability, and neuroactive properties. These modifications have continually presented hurdles in their identification and characterization. Early endeavors in their analysis relied on classical biochemical techniques that have led to the progressive development and use of novel proteomic-based approaches. The critical importance of these post-translationally modified amino acids and their specific assignment cannot be understated, having impact on their folding, pharmacological selectivity, and potency. Such modifications at an amino acid level may also provide additional insight into the advancement of conopeptide drugs in the quest for precise pharmacological targeting. To achieve this end, a concerted effort between the classical and novel approaches is needed to completely elucidate the role of post-translational modifications in conopeptide structure and dynamics. This paper provides a reflection in the advancements observed in dealing with numerous and multiple post-translationally modified amino acids within conotoxins and conopeptides and provides a summary of the current techniques used in their identification.
NASA Technical Reports Server (NTRS)
Allen, B. Danette
1998-01-01
In the traditional 'waterfall' model of the software project life cycle, the Requirements Phase ends and flows into the Design Phase, which ends and flows into the Development Phase. Unfortunately, the process rarely, if ever, works so smoothly in practice. Instead, software developers often receive new requirements, or modifications to the original requirements, well after the earlier project phases have been completed. In particular, projects with shorter than ideal schedules are highly susceptible to frequent requirements changes, as the software requirements analysis phase is often forced to begin before the overall system requirements and top-level design are complete. This results in later modifications to the software requirements, even though the software design and development phases may be complete. Requirements changes received in the later stages of a software project inevitably lead to modification of existing developed software. Presented here is a series of software design techniques that can greatly reduce the impact of last-minute requirements changes. These techniques were successfully used to add built-in flexibility to two complex software systems in which the requirements were expected to (and did) change frequently. These large, real-time systems were developed at NASA Langley Research Center (LaRC) to test and control the Lidar In-Space Technology Experiment (LITE) instrument which flew aboard the space shuttle Discovery as the primary payload on the STS-64 mission.
General review of the MOSTAS computer code for wind turbines
NASA Technical Reports Server (NTRS)
Dungundji, J.; Wendell, J. H.
1981-01-01
The MOSTAS computer code for wind turbine analysis is reviewed, and techniques and methods used in its analyses are described. Impressions of its strengths and weakness, and recommendations for its application, modification, and further development are made. Basic techniques used in wind turbine stability and response analyses for systems with constant and periodic coefficients are reviewed.
Source term evaluation for combustion modeling
NASA Technical Reports Server (NTRS)
Sussman, Myles A.
1993-01-01
A modification is developed for application to the source terms used in combustion modeling. The modification accounts for the error of the finite difference scheme in regions where chain-branching chemical reactions produce exponential growth of species densities. The modification is first applied to a one-dimensional scalar model problem. It is then generalized to multiple chemical species, and used in quasi-one-dimensional computations of shock-induced combustion in a channel. Grid refinement studies demonstrate the improved accuracy of the method using this modification. The algorithm is applied in two spatial dimensions and used in simulations of steady and unsteady shock-induced combustion. Comparisons with ballistic range experiments give confidence in the numerical technique and the 9-species hydrogen-air chemistry model.
NASA Technical Reports Server (NTRS)
Jones, R. (Principal Investigator); Harwood, P.; Finley, R.; Clements, G.; Lodwick, L.; Mcculloch, S.; Marphy, D.
1976-01-01
The author has identified the following significant results. The most significant ADP result was the modification of the DAM package to produce classified printouts, scaled and registered to U.S.G.S., 71/2 minute topographic maps from LARSYS-type classification files. With this modification, all the powerful scaling and registration capabilities of DAM become available for multiclass classification files. The most significant results with respect to image interpretation were the application of mapping techniques to a new, more complex area, and the refinement of an image interpretation procedure which should yield the best results.
NASA Astrophysics Data System (ADS)
Yuan, C. C.; Zhang, D.; Gan, Y.
2017-03-01
Engineering atomic force microscopy tips for reliable tip enhanced Raman spectroscopy (TERS) and colloidal probe technique are becoming routine practices in many labs. In this 10 year update review, various new tip modification methods developed over the past decade are briefly reviewed to help researchers select the appropriate method. The perspective is put in a large context to discuss the opportunities and challenges in this area, including novel combinations of seemingly different methods, potential applications of some methods which were not originally intended for TERS tip fabrication, and the problems of high cost and poor reproducibility of tip fabrication.
Neo-yoke repair for severe hypospadias: A simple modification for better outcome.
Seleim, Hamed M; Morsi, Hani; Elbarbary, Mohamed M
2017-06-01
Although staged repair for reconstructing severe hypospadias is more popular, various one-stage repairs have been attempted. Koyanagi repair (parameatal-based and fully extended circumferential foreskin flap urethroplasty) has enabled correction of severe hypospadias in one stage. However, its un-acceptably high incidence of complications has initiated a series of technical modifications, including the "yoke" repair. To retrospectively analyze the outcome of a proposed modification of the originally described yoke repair, for patients with severe hypospadias. This modification was developed to reduce complications. Over 4 years (between Jan 2011 and Jan 2015), all cases of severe hypospadias were included in this study; except those with prior attempts at repair, circumcised cases, and cases with severe hypogonadism - because of partial androgen insensitivity - not responding to hormonal manipulations. The make-up of the neo-urethra in this modification is the urethral plate with its spongiosal tissue proximally, a circum-coronal preputial pedicled flap in the middle, and an incorporated part of the augmented preputial flap and the preserved V-shaped glanular urethra, distally. Close postoperative follow-up was conducted to investigate the outcome. Thirty-one children with a median age of 32.48 months had repair of severe hypospadias using the neo-yoke technique. After a median follow-up of 26.7 months, the overall complication rate was 16.1%. Four children developed urethrocutaneous fistula (12.9%). Meatal drop-back occurred in one case (3.2%). No meatal stenosis or urethral sacculation was detected during follow-up of the studied group. Almost all cases had cosmetically appealing outlook. Single-staged repair of severe hypospadias using parameatal foreskin-based urethroplasty has passed through different modifications, all aimed at optimizing the outcome (Table). Neo-yoke repair for severe hypospadias is a natural development of established one-stage techniques, which resulted in better mid-term outcomes. However, an extended study is needed to declare the long-term results. Copyright © 2017 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.
Techniques for forced response involving discrete nonlinearities. I - Theory. II - Applications
NASA Astrophysics Data System (ADS)
Avitabile, Peter; Callahan, John O.
Several new techniques developed for the forced response analysis of systems containing discrete nonlinear connection elements are presented and compared to the traditional methods. In particular, the techniques examined are the Equivalent Reduced Model Technique (ERMT), Modal Modification Response Technique (MMRT), and Component Element Method (CEM). The general theory of the techniques is presented, and applications are discussed with particular reference to the beam nonlinear system model using ERMT, MMRT, and CEM; frame nonlinear response using the three techniques; and comparison of the results obtained by using the ERMT, MMRT, and CEM models.
Mechanical methods of chaparral modification
George Roby; Lisle Green
1976-01-01
Chaparral modification is undertaken for a variety of land-management purposes. To help land managers in selecting equipment and methods for such work, practitioners in county, State, and Federal modification projects were asked for evaluations of equipment and techniques they had used. This handbook describes the alternative techniques and equipment, provides...
Flame resistant elastic elastomeric fibers
NASA Technical Reports Server (NTRS)
Howarth, J. T.; Massucco, A. A.
1972-01-01
Development of materials to improve flame resistance of elastic elastomeric fibers is discussed. Two approaches, synthesis of polyether based urethanes and modification of synthesized urethanes with flame ratardant additives, are described. Specific applications of both techniques are presented.
Advances in the surface modification techniques of bone-related implants for last 10 years
Qiu, Zhi-Ye; Chen, Cen; Wang, Xiu-Mei; Lee, In-Seop
2014-01-01
At the time of implanting bone-related implants into human body, a variety of biological responses to the material surface occur with respect to surface chemistry and physical state. The commonly used biomaterials (e.g. titanium and its alloy, Co–Cr alloy, stainless steel, polyetheretherketone, ultra-high molecular weight polyethylene and various calcium phosphates) have many drawbacks such as lack of biocompatibility and improper mechanical properties. As surface modification is very promising technology to overcome such problems, a variety of surface modification techniques have been being investigated. This review paper covers recent advances in surface modification techniques of bone-related materials including physicochemical coating, radiation grafting, plasma surface engineering, ion beam processing and surface patterning techniques. The contents are organized with different types of techniques to applicable materials, and typical examples are also described. PMID:26816626
[Percutaneous ablation of metastases: where are we and new techniques].
Palussière, Jean; Buy, Xavier; Fonck, Mariane
2013-04-01
When a metastatic disease is localized and slowly evolving either spontaneously or after a general treatment, a local treatment may be proposed. For about 15 years, image-guided percutaneous ablation has been developed which allows to treat tumors with temperature modifications. These mini-invasive techniques may be repeated in patients whose disease may be chronic. Ablation techniques are also used in a more palliative manner on bone metastases to obtain pain relief.
A novel technique for prevention of self-mutilation in three Harris' hawks (Parabuteo unicinctus).
Smith, Stephen P; Forbes, Neil A
2009-03-01
Feather destructive behavior is an ever-increasing problem in captive birds of prey and any associated self-mutilation can be challenging to manage. This clinical report describes a noninvasive, nonpainful, temporary beak modification technique used to prevent self-mutilation in 3 Harris' hawks (Parabuteo unicinctus), when other methods and husbandry modifications had failed. The technique was successful in all 3 birds, and no adverse effects were observed. Further investigations are required to further evaluate if this beak modification technique causes any psychologic or physical stress to the avian patient.
Modeling and prototyping of biometric systems using dataflow programming
NASA Astrophysics Data System (ADS)
Minakova, N.; Petrov, I.
2018-01-01
The development of biometric systems is one of the labor-intensive processes. Therefore, the creation and analysis of approaches and techniques is an urgent task at present. This article presents a technique of modeling and prototyping biometric systems based on dataflow programming. The technique includes three main stages: the development of functional blocks, the creation of a dataflow graph and the generation of a prototype. A specially developed software modeling environment that implements this technique is described. As an example of the use of this technique, an example of the implementation of the iris localization subsystem is demonstrated. A variant of modification of dataflow programming is suggested to solve the problem related to the undefined order of block activation. The main advantage of the presented technique is the ability to visually display and design the model of the biometric system, the rapid creation of a working prototype and the reuse of the previously developed functional blocks.
Evaluation of Techniques for Reducing In-Use Automotive Fuel Consumption
DOT National Transportation Integrated Search
1981-04-01
This report presents an assessment of proposed techniques for reducing fuel consumption in the in-use light duty road vehicle fleet. Three general classes of techniques are treated: (1) modification of vehicles, (2) modification of traffic flow, and ...
Knowledge-based system verification and validation
NASA Technical Reports Server (NTRS)
Johnson, Sally C.
1990-01-01
The objective of this task is to develop and evaluate a methodology for verification and validation (V&V) of knowledge-based systems (KBS) for space station applications with high reliability requirements. The approach consists of three interrelated tasks. The first task is to evaluate the effectiveness of various validation methods for space station applications. The second task is to recommend requirements for KBS V&V for Space Station Freedom (SSF). The third task is to recommend modifications to the SSF to support the development of KBS using effectiveness software engineering and validation techniques. To accomplish the first task, three complementary techniques will be evaluated: (1) Sensitivity Analysis (Worchester Polytechnic Institute); (2) Formal Verification of Safety Properties (SRI International); and (3) Consistency and Completeness Checking (Lockheed AI Center). During FY89 and FY90, each contractor will independently demonstrate the user of his technique on the fault detection, isolation, and reconfiguration (FDIR) KBS or the manned maneuvering unit (MMU), a rule-based system implemented in LISP. During FY91, the application of each of the techniques to other knowledge representations and KBS architectures will be addressed. After evaluation of the results of the first task and examination of Space Station Freedom V&V requirements for conventional software, a comprehensive KBS V&V methodology will be developed and documented. Development of highly reliable KBS's cannot be accomplished without effective software engineering methods. Using the results of current in-house research to develop and assess software engineering methods for KBS's as well as assessment of techniques being developed elsewhere, an effective software engineering methodology for space station KBS's will be developed, and modification of the SSF to support these tools and methods will be addressed.
Advances in Adaptive Control Methods
NASA Technical Reports Server (NTRS)
Nguyen, Nhan
2009-01-01
This poster presentation describes recent advances in adaptive control technology developed by NASA. Optimal Control Modification is a novel adaptive law that can improve performance and robustness of adaptive control systems. A new technique has been developed to provide an analytical method for computing time delay stability margin for adaptive control systems.
ERIC Educational Resources Information Center
Cohen Kadosh, Kathrin; Linden, David E. J.; Lau, Jennifer Y. F.
2013-01-01
Adolescence is a period of profound change, which holds substantial developmental milestones, but also unique challenges to the individual. In this opinion paper, we highlight the potential of combining two recently developed behavioural and neural training techniques (cognitive bias modification and functional magnetic neuroimaging-based…
Vásquez-Garzón, Verónica R; Rouimi, Patrick; Jouanin, Isabelle; Waeg, Georg; Zarkovic, Neven; Villa-Treviño, Saul; Guéraud, Françoise
2012-05-01
Among disruptions induced by oxidative stress, modifications of proteins, particularly irreversible carbonylation, are associated with the development of several diseases, including cardiovascular diseases, neurodegenerative diseases, and cancer. Carbonylation of proteins can occur directly or indirectly through the adduction of lipid oxidation products. In this study, three classical and easy-to-perform techniques to detect direct or indirect carbonylation of proteins were compared. A model protein apomyoglobin and a complex mixture of rat liver cytosolic proteins were exposed to cumene hydroperoxide oxidation or adduction to the lipid peroxidation product 4-hydroxynonenal in order to test direct or indirect carbonylation, respectively. The technique using a specific anti-4-hydroxynonenal-histidine adduct antibody was effective to detect in vitro modification of model apomyoglobin and cytosolic proteins by 4-hydroxynonenal but not by direct carbonylation which was achieved by techniques using biotin-coupled hydrazide or dinitrophenylhydrazine derivatization of carbonyls. Sequential use of these methods enabled the detection of both direct and indirect carbonyl modification in proteins, although constitutively biotinylated proteins were detected by biotin-hydrazide. Although rather classical and efficient, methods for carbonyl detection on proteins in oxidative stress studies may be biased by some artifactual detections and complicated by proteins multimerizations. The use of more and more specific available antibodies is recommended to complete detection of lipid peroxidation product adducts on proteins.
Noise Suppression Methods for Robust Speech Processing
1981-04-01
1]. Techniques available for voice processor modification to account for noise contamination are being developed [4]. Preprocessor noise reduction...analysis window function. Principles governing discrete implementation of the transform pair are discussed, and relationships are formalized which specify
Skouteris, Helen; Morris, Heather; Nagle, Cate; Nankervis, Alison
2014-04-01
The prevalence of gestational diabetes mellitus (GDM) and obesity is increasing in developed countries, presenting significant challenges to acute care and public health. The aim of this study is to systematically review published controlled trials evaluating behavior modification interventions to prevent the development of GDM. Nine studies were identified involving such techniques as repetition of information, use of verbal and written educational information, goal setting, and planning, in addition to group and individual counseling sessions. Of the 3 trials with GDM incidence as a primary outcome, only 1 showed a significant reduction. GDM was a secondary outcome in 6 studies where the prevention of excessive gestational weight gain was the primary outcome and only 1 trial study determined an effective intervention. The small number of effective interventions highlights a significant gap in evidence to inform maternity health policy and practice.
A developer solution for tank processing of x-ray film under ambient, tropical conditions.
Wayrynen, R E; McKinney, W E
1976-05-01
A modification of a proprietary 90-sec. x-ray-film developer which permits its use as a hand-tank developer at ambient temperatures between 21.6 degrees-30.6 degrees C (80 degrees-100 degrees F) is described. This processing technique is useful in tropical countries where the control of developer temperature is particularly difficult.
NASA Technical Reports Server (NTRS)
Roskam, J.
1983-01-01
The transmission loss characteristics of panels using the acoustic intensity technique is presented. The theoretical formulation, installation of hardware, modifications to the test facility, and development of computer programs and test procedures are described. A listing of all the programs is also provided. The initial test results indicate that the acoustic intensity technique is easily adapted to measure transmission loss characteristics of panels. Use of this method will give average transmission loss values. The fixtures developed to position the microphones along the grid points are very useful in plotting the intensity maps of vibrating panels.
Becerra, Sandra C; Roy, Daniel C; Sanchez, Carlos J; Christy, Robert J; Burmeister, David M
2016-04-12
Bacterial infections are a common clinical problem in both acute and chronic wounds. With growing concerns over antibiotic resistance, treatment of bacterial infections should only occur after positive diagnosis. Currently, diagnosis is delayed due to lengthy culturing methods which may also fail to identify the presence of bacteria. While newer costly bacterial identification methods are being explored, a simple and inexpensive diagnostic tool would aid in immediate and accurate treatments for bacterial infections. Histologically, hematoxylin and eosin (H&E) and Gram stains have been employed, but are far from optimal when analyzing tissue samples due to non-specific staining. The goal of the current study was to develop a modification of the Gram stain that enhances the contrast between bacteria and host tissue. A modified Gram stain was developed and tested as an alternative to Gram stain that improves the contrast between Gram positive bacteria, Gram negative bacteria and host tissue. Initially, clinically relevant strains of Pseudomonas aeruginosa and Staphylococcus aureus were visualized in vitro and in biopsies of infected, porcine burns using routine Gram stain, and immunohistochemistry techniques involving bacterial strain-specific fluorescent antibodies as validation tools. H&E and Gram stain of serial biopsy sections were then compared to a modification of the Gram stain incorporating a counterstain that highlights collagen found in tissue. The modified Gram stain clearly identified both Gram positive and Gram negative bacteria, and when compared to H&E or Gram stain alone provided excellent contrast between bacteria and non-viable burn eschar. Moreover, when applied to surgical biopsies from patients that underwent burn debridement this technique was able to clearly detect bacterial morphology within host tissue. We describe a modification of the Gram stain that provides improved contrast of Gram positive and Gram negative microorganisms within host tissue. The samples used in this study demonstrate that this staining technique has laboratory and clinical applicability. This modification only adds minutes to traditional Gram stain with reusable reagents, and results in a cost- and time-efficient technique for identifying bacteria in any clinical biopsy containing connective tissue.
Development of Ultra-High Molecular Weight Polyethylene (UHMWPE) Coating by Cold Spray Technique
NASA Astrophysics Data System (ADS)
Ravi, Kesavan; Ichikawa, Yuji; Deplancke, Tiana; Ogawa, Kazuhiro; Lame, Olivier; Cavaille, Jean-Yves
2015-08-01
Ultra-high molecular weight polyethylene or UHMWPE is an extremely difficult material to coat with, as it is rubbery and chemically very inert. The Cold Spray process appears to be a promising alternative processing technique but polymers are in general difficult to deposit using this method. So, attempts to develop UHMWPE coatings were made using a downstream injection cold spray technique incorporating a few modifications. A conventional cold spray machine yielded only a few deposited particles of UHMWPE on the substrate surface, but with some modifications in the nozzle geometry (especially the length and inner geometry) a thin coating of 45 μm on Al substrate was obtained. Moreover, experiments with the addition of fumed nano-alumina to the feedstock yielded a coating of 1-4 mm thickness on Al and polypropylene substrates. UHMWPE was seen to be melt crystallized during the coating formation, as can be seen from the differential calorimetry curves. Influence of nano-ceramic particles was explained by observing the creation of a bridge bond between UHMWPE particles.
A comprehensive review of techniques for biofunctionalization of titanium
2011-01-01
A number of surface modification techniques using immobilization of biofunctional molecules of Titanium (Ti) for dental implants as well as surface properties of Ti and Ti alloys have been developed. The method using passive surface oxide film on titanium takes advantage of the fact that the surface film on Ti consists mainly of amorphous or low-crystalline and non-stoichiometric TiO2. In another method, the reconstruction of passive films, calcium phosphate naturally forms on Ti and its alloys, which is characteristic of Ti. A third method uses the surface active hydroxyl group. The oxide surface immediately reacts with water molecules and hydroxyl groups are formed. The hydroxyl groups dissociate in aqueous solutions and show acidic and basic properties. Several additional methods are also possible, including surface modification techniques, immobilization of poly(ethylene glycol), and immobilization of biomolecules such as bone morphogenetic protein, peptide, collagen, hydrogel, and gelatin. PMID:22324003
Scope of nanotechnology in modern textiles
USDA-ARS?s Scientific Manuscript database
This review article demonstrates the scope and applications of nanotechnology towards modification and development of advanced textile fibers, yarns and fabrics and their processing techniques. Basically, it summarizes the recent advances made in nanotechnology and its applications to cotton textil...
The Best of Practical Pointers.
ERIC Educational Resources Information Center
Association for Research, Administration, Professional Councils & Societies, Reston, VA.
This publication is a compilation of monographs offering practical suggestions for teachers of adapted physical education. It contains numerous suggestions on teaching techniques, activity adaptations, equipment modifications, programming information, coaching hints, skill development strategies, and curriculum data. The five sections offer…
A novel modification of the Turing test for artificial intelligence and robotics in healthcare.
Ashrafian, Hutan; Darzi, Ara; Athanasiou, Thanos
2015-03-01
The increasing demands of delivering higher quality global healthcare has resulted in a corresponding expansion in the development of computer-based and robotic healthcare tools that rely on artificially intelligent technologies. The Turing test was designed to assess artificial intelligence (AI) in computer technology. It remains an important qualitative tool for testing the next generation of medical diagnostics and medical robotics. Development of quantifiable diagnostic accuracy meta-analytical evaluative techniques for the Turing test paradigm. Modification of the Turing test to offer quantifiable diagnostic precision and statistical effect-size robustness in the assessment of AI for computer-based and robotic healthcare technologies. Modification of the Turing test to offer robust diagnostic scores for AI can contribute to enhancing and refining the next generation of digital diagnostic technologies and healthcare robotics. Copyright © 2014 John Wiley & Sons, Ltd.
Surface Modification of Dental Titanium Implant by Layer-by-Layer Electrostatic Self-Assembly
Shi, Quan; Qian, Zhiyong; Liu, Donghua; Liu, Hongchen
2017-01-01
In vivo implants that are composed of titanium and titanium alloys as raw materials are widely used in the fields of biology and medicine. In the field of dental medicine, titanium is considered to be an ideal dental implant material. Good osseointegration and soft tissue closure are the foundation for the success of dental implants. Therefore, the enhancement of the osseointegration and antibacterial abilities of titanium and its alloys has been the focus of much research. With its many advantages, layer-by-layer (LbL) assembly is a self-assembly technique that is used to develop multilayer films based on complementary interactions between differently charged polyelectrolytes. The LbL approach provides new methods and applications for the surface modification of dental titanium implant. In this review, the application of the LbL technique to surface modification of titanium including promoting osteogenesis and osseointegration, promoting the formation and healing of soft tissues, improving the antibacterial properties of titanium implant, achieving local drug delivery and sustained release is summarized. PMID:28824462
Chai, X S; Schork, F J; DeCinque, Anthony
2005-04-08
This paper reports an improved headspace gas chromatographic (GC) technique for determination of monomer solubilities in water. The method is based on a multiple headspace extraction GC technique developed previously [X.S. Chai, Q.X. Hou, F.J. Schork, J. Appl. Polym. Sci., in press], but with the major modification in the method calibration technique. As a result, only a few iterations of headspace extraction and GC measurement are required, which avoids the "exhaustive" headspace extraction, and thus the experimental time for each analysis. For highly insoluble monomers, effort must be made to minimize adsorption in the headspace sampling channel, transportation conduit and capillary column by using higher operating temperature and a short capillary column in the headspace sampler and GC system. For highly water soluble monomers, a new calibration method is proposed. The combinations of these technique modifications results in a method that is simple, rapid and automated. While the current focus of the authors is on the determination of monomer solubility in aqueous solutions, the method should be applicable to determination of solubility of any organic in water.
Wu, Ningling; Christenbury, Joseph G; Dishler, Jon G; Bozkurt, Tahir Kansu; Duel, Daniel; Zhang, Lijun; Hamilton, D Rex
2017-09-01
To identify risk factors for opaque bubble layer (OBL) formation and compare the incidence of OBL using a cone modification technique versus the original technique for LASIK flap creation using the VisuMax laser (Carl Zeiss Meditec, Jena, Germany). This retrospective study examined videos of flap creation using the VisuMax laser to identify OBL occurrence. Eyes were divided into three groups: eyes where OBL occurred using the original technique (OBL group), eyes where OBL did not occur using the original technique (no OBL group), and eyes in which the cone modification technique was used for LASIK flap creation (larger flap diameter) (cone modification technique group). Preoperative measurements including simulated keratometry (flat and steep) values, white-to-white distance (WTW), pachymetry, patient age and gender, amount of correction, flap parameters, energy setting, corneal hysteresis, and corneal resistance factor were analyzed to identify parameters with statistical difference between the OBL and no OBL groups. Incidence of OBL was compared between the original and cone modification techniques. OBL incidence was significantly lower with the cone modification technique (7.6%; 7 of 92 eyes) than with the original technique (28.8%; 34 of 118 eyes) (Fisher's exact test, P = .0009). Factors identified with a significant difference between eyes with and without OBL using the original technique were: corneal thickness (OBL: 561.2 μm, no OBL: 549.6 μm, P = .0132), WTW diameter (OBL: 11.6 mm, no OBL: 11.9 mm, P = .0048), corneal resistance factor (OBL: 10.4 mm Hg, no OBL: 9.6 mm Hg, P = 0.0329), and corneal astigmatism (OBL: 0.80 diopter, no OBL: 1.00 diopter, P = .0472) CONCLUSIONS: Less astigmatic, thicker, denser, and smaller corneas increased the risk of OBL using the original technique for flap creation. The cone modification technique was associated with lower risk of OBL formation, even in eyes with significant risk factors for OBL using the original technique. [J Refract Surg. 2017;33(9):584-590.]. Copyright 2017, SLACK Incorporated.
Future Software Sizing Metrics and Estimation Challenges
2011-07-01
systems 4. Ultrahigh software system assurance 5. Legacy maintenance and Brownfield development 6. Agile and Lean/ Kanban development. This paper...refined as the design of the maintenance modifications or Brownfield re-engineering is determined. VII. 6. AGILE AND LEAN/ KANBAN DEVELOPMENT The...difficulties of software maintenance estimation can often be mitigated by using lean workflow management techniques such as Kanban [25]. In Kanban
CCD filter and transform techniques for interference excision
NASA Technical Reports Server (NTRS)
Borsuk, G. M.; Dewitt, R. N.
1976-01-01
The theoretical and some experimental results of a study aimed at applying CCD filter and transform techniques to the problem of interference excision within communications channels were presented. Adaptive noise (interference) suppression was achieved by the modification of received signals such that they were orthogonal to the recently measured noise field. CCD techniques were examined to develop real-time noise excision processing. They were recursive filters, circulating filter banks, transversal filter banks, an optical implementation of the chirp Z transform, and a CCD analog FFT.
Manufacturer evaluations of endograft modifications.
Waninger, Matthew S; Whirley, Robert G; Smith, Louis J; Wolf, Ben S
2013-03-01
The motivation to modify the design of a vascular device can arise from a number of sources. Clinical experience with the unmodified device could suggest new design modifications to improve device performance or clinical outcomes. Similarly, clinical success with a device often suggests modifications that could broaden the applicability of the device to enable treatment of different or more advanced disease states. As a specific example, both of these scenarios have arisen during the last decade in the evolution of endovascular grafts for the treatment of abdominal aortic aneurysms, with modifications enabling the treatment of patients with shorter infrarenal necks, more angulated anatomy, and smaller access vessels. These modifications have been made by manufacturers and additionally by physicians who create branched and fenestrated devices. The experience to date with the use of fenestrated devices and the development of chimney, snorkel, and periscope techniques suggests that modifications to off-the-shelf devices may provide some clinical benefit. This experience provides additional motivation for manufacturers to develop devices to address the clinical needs not met with their current product lines. For manufacturers, the device development process includes an assessment of the new device design to determine the appropriate evaluation strategy to support the safety and effectiveness of the modified device. This report provides a high-level overview of the process generally followed by device manufacturers to evaluate a proposed device modification before market release, in accordance with local country regulations and recognized international standards such as the International Organization of Standardization (ISO) standards for endovascular grafts (ISO 25539 Part 1). Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.
Physical and chemical modification of starches: A review.
Zia-Ud-Din; Xiong, Hanguo; Fei, Peng
2017-08-13
The development of green material in the last decade has been increased, which tends to reduce the impact of humans on the environment. Starch as an agro-sourced polymer has become very popular recently due to its characteristics, such as wide availability, low cost, and total compostability without toxic residues. Starch is the most abundant organic compound found in nature after cellulose. Starches are inherently unsuitable for most applications and, therefore, must be modified physically and/or chemically to enhance their positive attributes and/or to minimize their defects. Modification of starches is generally carried out by using physical methods that are simple and inexpensive due to the absence of chemical agents. However, chemical modification involves the exploitation of hydroxyl group present in the starches that brings about the desired results for the utilization of starches for specific applications. All these techniques have the tendency to produce starches with altered physicochemical properties and modified structural attributes for various food and nonfood applications. This paper reviews the recent knowledge and developments using physical modification methods, some chemical modification methods, and a combination of both to produce a novel molecule with substantial applications, in food industry along with future perspectives.
Cost effectiveness as applied to the Viking Lander systems-level thermal development test program
NASA Technical Reports Server (NTRS)
Buna, T.; Shupert, T. C.
1974-01-01
The economic aspects of thermal testing at the systems-level as applied to the Viking Lander Capsule thermal development program are reviewed. The unique mission profile and pioneering scientific goals of Viking imposed novel requirements on testing, including the development of a simulation technique for the Martian thermal environment. The selected approach included modifications of an existing conventional thermal vacuum facility, and improved test-operational techniques that are applicable to the simulation of the other mission phases as well, thereby contributing significantly to the cost effectiveness of the overall thermal test program.
Electronic test instrumentation and techniques: A compilation
NASA Technical Reports Server (NTRS)
1974-01-01
The uses of test equipment and techniques used in space research and development programs are discussed. Modifications and adaptations to enlarge the scope of usefulness or divert the basic uses to alternate applications are analyzed. The items of equipment which have been of benefit to professional personnel in the enlargement and improvement of quality control capabilities are identified. Items which have been simplified or made more accurate in conducting measurements are described.
Epicutaneous immunotherapy for food allergy as a novel pathway for oral tolerance induction.
Mondoulet, Lucie; Dioszeghy, Vincent; Thébault, Claude; Benhamou, Pierre-Henri; Dupont, Christophe
2015-01-01
Epicutaneous immunotherapy is a developing technique, aiming at desensitizing patients with food allergy with less risks that oral ingestion or injection could generate. Several clinical trials have been performed and are currently running, in milk and peanut allergy, assessing the safety of the technique and its efficacy. Preclinical models indicate a major role in the mechanisms of desensitization, for example, Tregs and epigenetic modifications.
Heritable strategies for controlling insect vectors of disease.
Burt, Austin
2014-01-01
Mosquito-borne diseases are causing a substantial burden of mortality, morbidity and economic loss in many parts of the world, despite current control efforts, and new complementary approaches to controlling these diseases are needed. One promising class of new interventions under development involves the heritable modification of the mosquito by insertion of novel genes into the nucleus or of Wolbachia endosymbionts into the cytoplasm. Once released into a target population, these modifications can act to reduce one or more components of the mosquito population's vectorial capacity (e.g. the number of female mosquitoes, their longevity or their ability to support development and transmission of the pathogen). Some of the modifications under development are designed to be self-limiting, in that they will tend to disappear over time in the absence of recurrent releases (and hence are similar to the sterile insect technique, SIT), whereas other modifications are designed to be self-sustaining, spreading through populations even after releases stop (and hence are similar to traditional biological control). Several successful field trials have now been performed with Aedes mosquitoes, and such trials are helping to define the appropriate developmental pathway for this new class of intervention.
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 1-year vocational training program to prepare students for entry-level employment as industrial maintenance technicians. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi…
Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.
Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y
2017-01-01
Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.
CHAPTER 7: Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages
Zhu, Rui; Zacharias, Lauren; Wooding, Kerry M.; Peng, Wenjing; Mechref, Yehia
2017-01-01
Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins while automated software tools started replacing manual processing to improve the reliability and throughout of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. PMID:28109440
Functional Electrospun Nanofibrous Scaffolds for Biomedical Applications
Liang, Dehai; Hsiao, Benjamin S.; Chu, Benjamin
2009-01-01
Functional nanofibrous scaffolds produced by electrospinning have great potential in many biomedical applications, such as tissue engineering, wound dressing, enzyme immobilization and drug (gene) delivery. For a specific successful application, the chemical, physical and biological properties of electrospun scaffolds should be adjusted to match the environment by using a combination of multi-component compositions and fabrication techniques where electrospinning has often become a pivotal tool. The property of the nanofibrous scaffold can be further improved with innovative development in electrospinning processes, such as two-component electrospinning and in-situ mixing electrospinning. Post modifications of electrospun membranes also provide effective means to render the electrospun scaffolds with controlled anisotropy and porosity. In this review, we review the materials, techniques and post modification methods to functionalize electrospun nanofibrous scaffolds suitable for biomedical applications. PMID:17884240
A nonlinear model for gas chromatograph systems
NASA Technical Reports Server (NTRS)
Feinberg, M. P.
1975-01-01
Fundamental engineering design techniques and concepts were studied for the optimization of a gas chromatograph-mass spectrometer chemical analysis system suitable for use on an unmanned, Martian roving vehicle. Previously developed mathematical models of the gas chromatograph are found to be inadequate for predicting peak heights and spreading for some experimental conditions and chemical systems. A modification to the existing equilibrium adsorption model is required; the Langmuir isotherm replaces the linear isotherm. The numerical technique of Crank-Nicolson was studied for use with the linear isotherm to determine the utility of the method. Modifications are made to the method eliminate unnecessary calculations which result in an overall reduction of the computation time of about 42 percent. The Langmuir isotherm is considered which takes into account the composition-dependent effects on the thermodynamic parameter, mRo.
Combining genomic and proteomic approaches for epigenetics research
Han, Yumiao; Garcia, Benjamin A
2014-01-01
Epigenetics is the study of changes in gene expression or cellular phenotype that do not change the DNA sequence. In this review, current methods, both genomic and proteomic, associated with epigenetics research are discussed. Among them, chromatin immunoprecipitation (ChIP) followed by sequencing and other ChIP-based techniques are powerful techniques for genome-wide profiling of DNA-binding proteins, histone post-translational modifications or nucleosome positions. However, mass spectrometry-based proteomics is increasingly being used in functional biological studies and has proved to be an indispensable tool to characterize histone modifications, as well as DNA–protein and protein–protein interactions. With the development of genomic and proteomic approaches, combination of ChIP and mass spectrometry has the potential to expand our knowledge of epigenetics research to a higher level. PMID:23895656
Development of advanced avionics systems applicable to terminal-configured vehicles
NASA Technical Reports Server (NTRS)
Heimbold, R. L.; Lee, H. P.; Leffler, M. F.
1980-01-01
A technique to add the time constraint to the automatic descent feature of the existing L-1011 aircraft Flight Management System (FMS) was developed. Software modifications were incorporated in the FMS computer program and the results checked by lab simulation and on a series of eleven test flights. An arrival time dispersion (2 sigma) of 19 seconds was achieved. The 4 D descent technique can be integrated with the time-based metering method of air traffic control. Substantial reductions in delays at today's busy airports should result.
Uno, Narumi; Abe, Satoshi; Oshimura, Mitsuo; Kazuki, Yasuhiro
2018-02-01
Chromosome transfer technology, including chromosome modification, enables the introduction of Mb-sized or multiple genes to desired cells or animals. This technology has allowed innovative developments to be made for models of human disease and humanized animals, including Down syndrome model mice and humanized transchromosomic (Tc) immunoglobulin mice. Genome editing techniques are developing rapidly, and permit modifications such as gene knockout and knockin to be performed in various cell lines and animals. This review summarizes chromosome transfer-related technologies and the combined technologies of chromosome transfer and genome editing mainly for the production of cell/animal models of human disease and humanized animal models. Specifically, these include: (1) chromosome modification with genome editing in Chinese hamster ovary cells and mouse A9 cells for efficient transfer to desired cell types; (2) single-nucleotide polymorphism modification in humanized Tc mice with genome editing; and (3) generation of a disease model of Down syndrome-associated hematopoiesis abnormalities by the transfer of human chromosome 21 to normal human embryonic stem cells and the induction of mutation(s) in the endogenous gene(s) with genome editing. These combinations of chromosome transfer and genome editing open up new avenues for drug development and therapy as well as for basic research.
Classroom Management Through the Application of Behavior Modification Techniques.
ERIC Educational Resources Information Center
Ferinden, William E., Jr.
The primary aim of this book is to bring to the grade school teacher a survey of the most recent techniques and ideas of behavior modification which are applicable to good classroom management. All of the approaches and techniques presented could be of interest to teachers working at all grade levels. Since research has shown that the systematic…
Behavior Modification in the Classroom
ERIC Educational Resources Information Center
Whitman, Mryon; Whitman, Joan
1971-01-01
This article presents the theoretical rationale for behavior modification, principally through its comparison with traditional psychotherapies, and suggests some behavior modification techniques for the classroom management of maladaptive behavior. (Author)
Genetic modification through oligonucleotide-mediated mutagenesis. A GMO regulatory challenge?
Breyer, Didier; Herman, Philippe; Brandenburger, Annick; Gheysen, Godelieve; Remaut, Erik; Soumillion, Patrice; Van Doorsselaere, Jan; Custers, René; Pauwels, Katia; Sneyers, Myriam; Reheul, Dirk
2009-01-01
In the European Union, the definition of a GMO is technology-based. This means that a novel organism will be regulated under the GMO regulatory framework only if it has been developed with the use of defined techniques. This approach is now challenged with the emergence of new techniques. In this paper, we describe regulatory and safety issues associated with the use of oligonucleotide-mediated mutagenesis to develop novel organisms. We present scientific arguments for not having organisms developed through this technique fall within the scope of the EU regulation on GMOs. We conclude that any political decision on this issue should be taken on the basis of a broad reflection at EU level, while avoiding discrepancies at international level.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vance, B.; Mendillo, M.
1981-04-30
A three-dimensional model of the ionosphere was developed including chemical reactions and neutral and plasma transport. The model uses Finite Element Simulation to simulate ionospheric modification rather than solving a set of differential equations. The initial conditions of the Los Alamos Scientific Laboratory experiments, Lagopedo Uno and Dos, were input to the model, and these events were simulated. Simulation results were compared to ground and rocketborne electron-content measurements. A simulation of the transport of released SF6 was also made.
Utilization of TALEN and CRISPR/Cas9 technologies for gene targeting and modification
Pu, Jiali; Zhang, Baorong; Feng, Jian
2015-01-01
The capability to modify the genome precisely and efficiently offers an extremely useful tool for biomedical research. Recent developments in genome editing technologies such as transcription activator-like effector nuclease and the clustered regularly interspaced short palindromic repeats system have made genome modification available for a number of organisms with relative ease. Here, we introduce these genome editing techniques, compare and contrast each technical approach and discuss their potential to study the underlying mechanisms of human disease using patient-derived induced pluripotent stem cells. PMID:25956682
Omics Approaches for the Engineering of Pathogen Resistant Plants.
Gomez-Casati, Diego F; Pagani, María A; Busi, María V; Bhadauria, Vijai
2016-01-01
The attack of different pathogens, such as bacteria, fungi and viruses has a negative impact on crop production. In counter such attacks, plants have developed different strategies involving the modification of gene expression, activation of several metabolic pathways and post-translational modification of proteins, which culminate into the accumulation of primary and secondary metabolites implicated in plant defense responses. The recent advancement in omics techniques allows the increase coverage of plants transcriptomes, proteomes and metabolomes during pathogen attack, and the modulation of the response after the infection. Omics techniques also allow us to learn more about the biological cycle of the pathogens in addition to the identification of novel virulence factors in pathogens and their host targets. Both approaches become important to decipher the mechanism underlying pathogen attacks and to develop strategies for improving disease-resistant plants. In this review, we summarize some of the contribution of genomics, transcriptomics, proteomics, metabolomics and metallomics in devising the strategies to obtain plants with increased resistance to pathogens. These approaches constitute important research tools in the development of new technologies for the protection against diseases and increase plant production.
Schnick, Rosalie A.; Morton, John M.; Mochalski, Jeffrey C.; Beall, Jonathan T.
1982-01-01
Extensive information is provided on techniques that can reduce or eliminate the negative impact of man's activities (particularly those related to navigation) on large river systems, with special reference to the Upper Mississippi River. These techniques should help resource managers who are concerned with such river systems to establish sound environmental programs. Discussion of each technique or group of techniques include (1) situation to be mitigated or enhanced; (2) description of technique; (3) impacts on the environment; (4) costs; and (5) evaluation for use on the Upper Mississippi River Systems. The techniques are divided into four primary categories: Bank Stabilization Techniques, Dredging and Disposal of Dredged Material, Fishery Management Techniques, and Wildlife Management Techniques. Because techniques have been grouped by function, rather than by structure, some structures are discussed in several contexts. For example, gabions are discussed for use in revetments, river training structures, and breakwaters. The measures covered under Bank Stabilization Techniques include the use of riprap revetments, other revetments, bulkheads, river training structures, breakwater structures, chemical soil stabilizers, erosion-control mattings, and filter fabrics; the planting of vegetation; the creation of islands; the creation of berms or enrichment of beaches; and the control of water level and boat traffic. The discussions of Dredging and the Disposal of Dredged Material consider dredges, dredging methods, and disposal of dredged material. The following subjects are considered under Fishery Management Techniques: fish attractors; spawning structures; nursery ponds, coves, and marshes; fish screens and barriers; fish passage; water control structures; management of water levels and flows; wing dam modification; side channel modification; aeration techniques; control of nuisance aquatic plants; and manipulated of fish populations. Wildlife Management Techniques include treatments of artificial nest structures, island creation or development, marsh creation or development, greentree reservoirs and mast management, vegetation control, water level control, and revegetation.
Methods for stable recording of short-circuit current in a Na+-transporting epithelium.
Gondzik, Veronika; Awayda, Mouhamed S
2011-07-01
Epithelial Na(+) transport as measured by a variety of techniques, including the short-circuit current technique, has been described to exhibit a "rundown" phenomenon. This phenomenon manifests as time-dependent decrease of current and resistance and precludes the ability to carry out prolonged experiments aimed at examining the regulation of this transport. We developed methods for prolonged stable recordings of epithelial Na(+) transport using modifications of the short-circuit current technique and commercial Ussing-type chambers. We utilize the polarized MDCK cell line expressing the epithelial Na(+) channel (ENaC) to describe these methods. Briefly, existing commercial chambers were modified to allow continuous flow of Ringer solution and precise control of such flow. Chamber manifolds and associated plumbing were modified to allow precise temperature clamp preventing temperature oscillations. Recording electrodes were modified to eliminate the use of KCl and prevent membrane depolarization from KCl leakage. Solutions utilized standard bicarbonate-based buffers, but all gasses were prehydrated to clamp buffer osmolarity. We demonstrate that these modifications result in measurements of current and resistance that are stable for at least 2 h. We further demonstrate that drifts in osmolarity similar to those obtained before prior to our modifications can lead to a decrease of current and resistance similar to those attributed to rundown.
A Review of Some Alternative Approaches to Drug Management of Hyperactivity in Children.
ERIC Educational Resources Information Center
Walden, Everett L.; Thompson, Sheila A.
1981-01-01
Literature is cited on such classroom management techniques as environmental manipulations, curriculum modifications, behavior modification, and dealing with affective attitude. Also considered are home management techniques and self-control programs including biofeedback and relaxation training. (SB)
Hartung, Frank; Schiemann, Joachim
2014-06-01
Several new plant breeding techniques (NPBTs) have been developed during the last decade, and make it possible to precisely perform genome modifications in plants. The major problem, other than technical aspects, is the vagueness of regulation concerning these new techniques. Since the definition of eight NPBTs by a European expert group in 2007, there has been an ongoing debate on whether the resulting plants and their products are covered by GMO legislation. Obviously, cover by GMO legislation would severely hamper the use of NPBT, because genetically modified plants must pass a costly and time-consuming GMO approval procedure in the EU. In this review, we compare some of the NPBTs defined by the EU expert group with classical breeding techniques and conventional transgenic plants. The list of NPBTs may be shortened (or extended) during the international discussion process initiated by the Organization for Economic Co-operation and Development. From the scientific point of view, it may be argued that plants developed by NPBTs are often indistinguishable from classically bred plants and are not expected to possess higher risks for health and the environment. In light of the debate on the future regulation of NPBTs and the accumulated evidence on the biosafety of genetically modified plants that have been commercialized and risk-assessed worldwide, it may be suggested that plants modified by crop genetic improvement technologies, including genetic modification, NPBTs or other future techniques, should be evaluated according to the new trait and the resulting end product rather than the technique used to create the new plant variety. © 2013 The Authors The Plant Journal © 2013 John Wiley & Sons Ltd.
Workstations for people with disabilities: an example of a virtual reality approach
Budziszewski, Paweł; Grabowski, Andrzej; Milanowicz, Marcin; Jankowski, Jarosław
2016-01-01
This article describes a method of adapting workstations for workers with motion disability using computer simulation and virtual reality (VR) techniques. A workstation for grinding spring faces was used as an example. It was adjusted for two people with a disabled right upper extremity. The study had two stages. In the first, a computer human model with a visualization of maximal arm reach and preferred workspace was used to develop a preliminary modification of a virtual workstation. In the second stage, an immersive VR environment was used to assess the virtual workstation and to add further modifications. All modifications were assessed by measuring the efficiency of work and the number of movements involved. The results of the study showed that a computer simulation could be used to determine whether a worker with a disability could access all important areas of a workstation and to propose necessary modifications. PMID:26651540
Ying, Yuguang; Zhang, Huihua; Yu, Peiqiang
2018-02-16
The cutting-edge synchrotron radiation based and globar-sourced vibrational infrared microspectroscopy have recently been developed. These novel techniques are able to reveal structure features at cellular and molecular levels with the tested tissues being intact. However, to date, the advanced techniques are unfamiliar or unknown to food and feed scientists and have not been used to study the molecular structure changes in cool-climate cereal grain seeds and other types of bio-oil and bioenergy seeds. This article aims to provide some recent research in cool-climate cereal grains and other types of seeds on molecular structures and metabolic characteristics of carbohydrate and protein, and implication of microstructure modification through heat-related processing and trait alteration to bio-functions, molecular thermal stability and mobility, and nutrition with advanced molecular techniques- synchrotron radiation based and globar-sourced vibrational infrared microspectroscopy in the areas of (1) Inherent microstructure of cereal grain seeds; (2) The nutritional values of cereal grains; (3) Impact and modification of heat-related processing to cereal grain; (4) Conventional nutrition evaluation methodology; (5) Synchrotron radiation-based and globar-sourced vibrational (micro)-spectroscopy for molecular structure study and molecular thermal stability and mobility, and (6) Recent molecular spectroscopic technique applications in research on raw, traits altered and processed cool-climate cereal grains and other types of seeds. The information described in this article gives better insights of research progress and update in cool-climate cereal grains and other seeds with advanced molecular techniques.
The pursuit of colostomy continence.
Roberts, D J
1997-03-01
The lifelong management required by patients with permanent colostomies leads to dissatisfaction with quality of life for many. Through the years, multiple techniques have been attempted to improve the quality of life by pursuing colostomy continence. Such endeavors include surgical interventions, nonsurgical devices and management, and behavior modification techniques. Efforts in research and development continue, and the desire to achieve continence of the stoma remain common cause among persons with on ostomy and those involved in their care.
Incarnato, Danny; Morandi, Edoardo; Simon, Lisa Marie; Oliviero, Salvatore
2018-06-09
RNA is emerging as a key regulator of a plethora of biological processes. While its study has remained elusive for decades, the recent advent of high-throughput sequencing technologies provided the unique opportunity to develop novel techniques for the study of RNA structure and post-transcriptional modifications. Nonetheless, most of the required downstream bioinformatics analyses steps are not easily reproducible, thus making the application of these techniques a prerogative of few laboratories. Here we introduce RNA Framework, an all-in-one toolkit for the analysis of most NGS-based RNA structure probing and post-transcriptional modification mapping experiments. To prove the extreme versatility of RNA Framework, we applied it to both an in-house generated DMS-MaPseq dataset, and to a series of literature available experiments. Notably, when starting from publicly available datasets, our software easily allows replicating authors' findings. Collectively, RNA Framework provides the most complete and versatile toolkit to date for a rapid and streamlined analysis of the RNA epistructurome. RNA Framework is available for download at: http://www.rnaframework.com.
Kojima, Taisuke
2018-01-01
Molecular adsorption on a sensing surface involves molecule-substrate and molecule-molecule interactions. Combining optical systems and a quartz crystal microbalance (QCM) on the same sensing surface allows the quantification of such interactions and reveals the physicochemical properties of the adsorbed molecules. However, low sensitivity of the current reflection-based techniques compared to the QCM technique hinders the quantitative analysis of the adsorption events. Here, a layer-by-layer surface modification of a QCM sensor is studied to increase the optical sensitivity. The intermediate layers of organic-inorganic molecules and metal-metal oxide were explored on a gold (Au) surface of a QCM sensor. First, polyhedral oligomeric silsesquioxane-derivatives that served as the organic-inorganic intermediate layer were synthesized and modified on the Au-QCM surface. Meanwhile, titanium oxide, fabricated by anodic oxidation of titanium, was used as a metal-metal oxide intermediate layer on a titanium-coated QCM surface. The developed technique enabled interrogation of the molecular adsorption owing to the enhanced optical sensitivity.
Ferreira, Marcelo; Ferreira, Diego; Cunha, Rodrigo; Bicalho, Guilherme; Rodrigues, Eduardo
2018-06-01
To demonstrate different techniques and device modifications that can expand the anatomic suitability of the off-the-shelf multibranched t-Branch for treatment of thoracoabdominal aortic aneurysm. The t-Branch device is not customized for specific patient anatomy, and the most frequent limitations to its use are an inadequate sealing zone and renal artery anatomy. Experience with this device has prompted the development of several techniques that can be employed to maximize the suitability of this stent-graft. Advice is offered on modification of the device to minimize the risk of paraplegia or better match patient anatomy. Maneuvers are explained to ease delivery through tortuous anatomy or existing stent-grafts, catheterize visceral target vessels, select a bridging stent, reduce ischemia time in the limbs, and alter the configuration of the branches. Employing adjunctive maneuvers can increase the anatomic suitability of the t-Branch; in our experience, these techniques have increased the applicability to more than 80% of all elective and urgent thoracoabdominal aortic aneurysm cases.
Applications of physiological bases of ageing to forensic sciences. Estimation of age-at-death.
C Zapico, Sara; Ubelaker, Douglas H
2013-03-01
Age-at-death estimation is one of the main challenges in forensic sciences since it contributes to the identification of individuals. There are many anthropological techniques to estimate the age at death in children and adults. However, in adults this methodology is less accurate and requires population specific references. For that reason, new methodologies have been developed. Biochemical methods are based on the natural process of ageing, which induces different biochemical changes that lead to alterations in cells and tissues. In this review, we describe different attempts to estimate the age in adults based on these changes. Chemical approaches imply modifications in molecules or accumulation of some products. Molecular biology approaches analyze the modifications in DNA and chromosomes. Although the most accurate technique appears to be aspartic acid racemization, it is important to take into account the other techniques because the forensic context and the human remains available will determine the possibility to apply one or another methodology. Copyright © 2013 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 1-year vocational training program to prepare students for entry-level employment as laser machining technicians. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi volume…
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 1-year vocational training program to prepare students for entry-level employment as automated equipment repair technicians. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi…
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of a course syllabi, an instructor's handbook, and a student laboratory manual for a 2-year vocational training program to prepare students for entry-level employment as mold makers. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi volume begins with the…
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 2-year vocational training program to prepare students for entry-level employment as manufacturing technicians. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi volume begins…
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 2-year vocational training program to prepare students for entry-level employment as welders. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi volume begins with the MASTER…
Teachers Inservice Education for Learning Problems
ERIC Educational Resources Information Center
Smith, Stanley A.
1975-01-01
Describes workshop designed to aid kindergarten and first grade teachers in assessing a child's educational disability, deciding what to do about it and when to use referral. Concentrated on skills for evaluating the child's motor ability, intellegence level and emotional development. Also taught behavior modification techniques and remediation…
ERIC Educational Resources Information Center
Neiswender, Lenore
The paper describes a current research project now being conducted by the Experimental Manpower Laboratory at Mobilization for Youth (MFY-EML) in New York City. The overall objective of the MFY-EML is to develop and test new methods of teaching vocational skills to hard-to-employ youth. The MFY-EML is involved in developing a program to teach…
Study on modification of the Misgav Ladach method for cesarean section.
Li, M; Zou, L; Zhu, J
2001-01-01
172 cases of pregnant women scheduled for delivery by cesarean section were randomly assigned to 59 cases in modification group with modified Misgav Ladach technique, 57 cases in Misgav Ladach group with Misgav Ladach technique and 56 cases in Pfannenstiel group with Pfannenstiel technique from May to Dec. 1999. The modified points included: transversely incising the fascia 2 to 3 cm, then dividing it bluntly; without opening and dissociating the visceral peritoneum; two layers suturing of low transverse uterine incision; closing the skin by continuous suturing. Results showed the average delivery time in the modification group was (3.6 +/- 2.6) min and (5.7 +/- 2.9) min in the Misgav Ladach group (P < 0.05). Median operating time was (28.3 +/- 5.4) min in modification group compared with (27.5 +/- 6.5) min in the Misgav Ladach group (P > 0.05). Average blood loss was (128 +/- 35) ml in modification group compared with (212 +/- 147) ml in the Pfannenstiel group (P < 0.05). It was concluded that the modified Misgav Ladach technique not only preserved all advantages of Misgav Ladach method, but also had additional advantages, such as faster in delivering the fetus, less damage, easier mastering for obstetricians.
Ecological Effects of Weather Modification: A Problem Analysis.
ERIC Educational Resources Information Center
Cooper, Charles F.; Jolly, William C.
This publication reviews the potential hazards to the environment of weather modification techniques as they eventually become capable of producing large scale weather pattern modifications. Such weather modifications could result in ecological changes which would generally require several years to be fully evident, including the alteration of…
Coherent Doppler Lidar for Boundary Layer Studies and Wind Energy
NASA Astrophysics Data System (ADS)
Choukulkar, Aditya
This thesis outlines the development of a vector retrieval technique, based on data assimilation, for a coherent Doppler LIDAR (Light Detection and Ranging). A detailed analysis of the Optimal Interpolation (OI) technique for vector retrieval is presented. Through several modifications to the OI technique, it is shown that the modified technique results in significant improvement in velocity retrieval accuracy. These modifications include changes to innovation covariance portioning, covariance binning, and analysis increment calculation. It is observed that the modified technique is able to make retrievals with better accuracy, preserves local information better, and compares well with tower measurements. In order to study the error of representativeness and vector retrieval error, a lidar simulator was constructed. Using the lidar simulator a thorough sensitivity analysis of the lidar measurement process and vector retrieval is carried out. The error of representativeness as a function of scales of motion and sensitivity of vector retrieval to look angle is quantified. Using the modified OI technique, study of nocturnal flow in Owens' Valley, CA was carried out to identify and understand uncharacteristic events on the night of March 27th 2006. Observations from 1030 UTC to 1230 UTC (0230 hr local time to 0430 hr local time) on March 27 2006 are presented. Lidar observations show complex and uncharacteristic flows such as sudden bursts of westerly cross-valley wind mixing with the dominant up-valley wind. Model results from Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS RTM) and other in-situ instrumentations are used to corroborate and complement these observations. The modified OI technique is used to identify uncharacteristic and extreme flow events at a wind development site. Estimates of turbulence and shear from this technique are compared to tower measurements. A formulation for equivalent wind speed in the presence of variations in wind speed and direction, combined with shear is developed and used to determine wind energy content in presence of turbulence.
Behavior Modification Techniques. I: Overcorrection. II: Punishment.
ERIC Educational Resources Information Center
Sovner, Robert, Ed.; Hurley, Anne Des Noyers, Ed.
1983-01-01
Two newsletters review the principles and application of two behavior modification techniques with mentally retarded persons: overcorrection and punishment. Overcorrection may be either restitutional, in which the client is made to restore the environment to a far better state than before the inappropriate behavior occurred, or positive practice…
Hurricane Wave Topography and Directional Wave Spectra in Near Real-Time
2005-09-30
Develop and/or modify the real - time operating system and analysis techniques and programs of the NASA Scanning Radar Altimeter (SRA) to process the...Wayne Wright is responsible for the real - time operating system of the SRA and making whatever modifications are required to enable near real-time
USDA-ARS?s Scientific Manuscript database
Genetic engineering offers an opportunity to develop flower bulb crops with resistance to fungal, viral, and bacterial pathogens. Several of the flower bulb crops, Lilium spp., Gladiolus, Zantedeschia, Muscari, Hyacinthus, Narcissus, Ornithogalum, Iris, and Alstroemeria, have been transformed with t...
Recent patents of nanopore DNA sequencing technology: progress and challenges.
Zhou, Jianfeng; Xu, Bingqian
2010-11-01
DNA sequencing techniques witnessed fast development in the last decades, primarily driven by the Human Genome Project. Among the proposed new techniques, Nanopore was considered as a suitable candidate for the single DNA sequencing with ultrahigh speed and very low cost. Several fabrication and modification techniques have been developed to produce robust and well-defined nanopore devices. Many efforts have also been done to apply nanopore to analyze the properties of DNA molecules. By comparing with traditional sequencing techniques, nanopore has demonstrated its distinctive superiorities in main practical issues, such as sample preparation, sequencing speed, cost-effective and read-length. Although challenges still remain, recent researches in improving the capabilities of nanopore have shed a light to achieve its ultimate goal: Sequence individual DNA strand at single nucleotide level. This patent review briefly highlights recent developments and technological achievements for DNA analysis and sequencing at single molecule level, focusing on nanopore based methods.
Modal identification of dynamic mechanical systems
NASA Astrophysics Data System (ADS)
Srivastava, R. K.; Kundra, T. K.
1992-07-01
This paper reviews modal identification techniques which are now helping designers all over the world to improve the dynamic behavior of vibrating engineering systems. In this context the need to develop more accurate and faster parameter identification is ever increasing. A new dynamic stiffness matrix based identification method which is highly accurate, fast and system-dynamic-modification compatible is presented. The technique is applicable to all those multidegree-of-freedom systems where full receptance matrix can be experimentally measured.
Techniques of laparoscopic cholecystectomy: Nomenclature and selection.
Haribhakti, Sanjiv P; Mistry, Jitendra H
2015-01-01
There are more than 50 different techniques of laparoscopic cholecystectomy (LC) available in literature mainly due to modifications by surgeons in aim to improve postoperative outcome and cosmesis. These modifications include reduction in port size and/or number than what is used in standard LC. There is no uniform nomenclature to describe these different techniques so that it is not possible to compare the outcomes of different techniques. We brief the advantages and disadvantages of each of these techniques and suggest the situation where particular technique would be useful. We also propose a nomenclature which is easy to remember and apply, so that any future comparison will be possible between the techniques.
Sulfenic acid chemistry, detection and cellular lifetime☆
Gupta, Vinayak; Carroll, Kate S.
2014-01-01
Background Reactive oxygen species-mediated cysteine sulfenic acid modification has emerged as an important regulatory mechanism in cell signaling. The stability of sulfenic acid in proteins is dictated by the local microenvironment and ability of antioxidants to reduce this modification. Several techniques for detecting this cysteine modification have been developed, including direct and in situ methods. Scope of review This review presents a historical discussion of sulfenic acid chemistry and highlights key examples of this modification in proteins. A comprehensive survey of available detection techniques with advantages and limitations is discussed. Finally, issues pertaining to rates of sulfenic acid formation, reduction, and chemical trapping methods are also covered. Major conclusions Early chemical models of sulfenic acid yielded important insights into the unique reactivity of this species. Subsequent pioneering studies led to the characterization of sulfenic acid formation in proteins. In parallel, the discovery of oxidant-mediated cell signaling pathways and pathological oxidative stress has led to significant interest in methods to detect these modifications. Advanced methods allow for direct chemical trapping of protein sulfenic acids directly in cells and tissues. At the same time, many sulfenic acids are short-lived and the reactivity of current probes must be improved to sample these species, while at the same time, preserving their chemical selectivity. Inhibitors with binding scaffolds can be rationally designed to target sulfenic acid modifications in specific proteins. General significance Ever increasing roles for protein sulfenic acids have been uncovered in physiology and pathology. A more complete understanding of sulfenic acid-mediated regulatory mechanisms will continue to require rigorous and new chemical insights. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn. PMID:23748139
London, Douglas S; Stoll, Andrew L; Manning, Bruce B
2006-01-01
Modernization of agricultural systems to increase output causes changes to the nutritional content of food entire populations consume. Human nutritional needs differ from their "food", thus producing healthy agricultural products is not equivalent to providing agricultural products that are healthy for humans. Inclusion of the food production system as a factor in the increase of neuropsychiatric disorders and other chronic diseases helps explain negative trends in modern chronic diseases that remain unchecked despite stunning advances in modern medicine. Diseases in which our own technology plays a significant role include obesity and resulting disorders, such as diabetes, heart disease, hypertension, stroke and arthritis. Modernization's lure leads to importation of modern agricultural practices into a nutritionally vulnerable, malnourished and sometimes starving developing world. Wealthier nations hedge their food portfolio by having access to a wider variety of foods. The developing world's reliance on staple foods means even a minor widespread nutritional modification of one key food can have profound effects. New agricultural techniques may improve or exacerbate neuropsychiatric disorders through nutritional modification in regions where populations walk a nutritional tightrope with little margin for error. In most of the developing world western psychiatric interventions have failed to make inroads. People's consumption of fish has a demonstrated beneficial effect on their mental health and the omega-3 fatty acid content is a significant factor. Epidemiological, biological and agricultural studies implicate a lack of dietary omega-3s as a factor in certain mental disorders. Replenishing omega-3s has improved mental illnesses in controlled clinical trials. This article's detailed tilapia fish-farming model demonstrates how aquaculture/agriculture techniques can function as a public health intervention by increasing dietary omega-3s through creation of sustainable, economical and culturally appropriate food sources for the developing world.
Approximate techniques of structural reanalysis
NASA Technical Reports Server (NTRS)
Noor, A. K.; Lowder, H. E.
1974-01-01
A study is made of two approximate techniques for structural reanalysis. These include Taylor series expansions for response variables in terms of design variables and the reduced-basis method. In addition, modifications to these techniques are proposed to overcome some of their major drawbacks. The modifications include a rational approach to the selection of the reduced-basis vectors and the use of Taylor series approximation in an iterative process. For the reduced basis a normalized set of vectors is chosen which consists of the original analyzed design and the first-order sensitivity analysis vectors. The use of the Taylor series approximation as a first (initial) estimate in an iterative process, can lead to significant improvements in accuracy, even with one iteration cycle. Therefore, the range of applicability of the reanalysis technique can be extended. Numerical examples are presented which demonstrate the gain in accuracy obtained by using the proposed modification techniques, for a wide range of variations in the design variables.
Mainstreaming: Sharing Ideas, Strategies, Materials, Techniques.
ERIC Educational Resources Information Center
Hillside School, Cushing, OK.
The manual provides teaching approaches based on a model of least to highest modification of instruction, which may be used for a continuum of special education placements ranging from regular classroom through hospital settings. The first section on adaptive techniques (requiring the least modification) includes suggestions to adjust time for…
Two Student Self-Management Techniques Applied to Data-Based Program Modification.
ERIC Educational Resources Information Center
Wesson, Caren
Two student self-management techniques, student charting and student selection of instructional activities, were applied to ongoing data-based program modification. Forty-two elementary school resource room students were assigned randomly (within teacher) to one of three treatment conditions: Teacher Chart-Teacher Select Instructional Activities…
NASA Technical Reports Server (NTRS)
Gurtler, R. W.; Baghdadi, A.
1976-01-01
The objective of this research is to fully investigate the Ribbon-To-Ribbon (R-T-R) approach to silicon ribbon growth. Initial work has concentrated on modification and characterization of an existing R-T-R apparatus. In addition, equipment for auxiliary heating of the melt is being evaluated and acquired. Modification of the remote viewing system and mechanical staging are nearly complete. Characterization of the laser and other components is in progress and several auxiliary heating techniques are being investigated.
ERIC Educational Resources Information Center
Texas State Technical Coll. System, Waco.
This package consists of course syllabi, an instructor's handbook, and a student laboratory manual for a 2-year vocational training program to prepare students for entry-level employment as tool and die makers. The program was developed through a modification of the DACUM (Developing a Curriculum) technique. The course syllabi volume begins with…
A Novel Tool for Microbial Genome Editing Using the Restriction-Modification System.
Bai, Hua; Deng, Aihua; Liu, Shuwen; Cui, Di; Qiu, Qidi; Wang, Laiyou; Yang, Zhao; Wu, Jie; Shang, Xiuling; Zhang, Yun; Wen, Tingyi
2018-01-19
Scarless genetic manipulation of genomes is an essential tool for biological research. The restriction-modification (R-M) system is a defense system in bacteria that protects against invading genomes on the basis of its ability to distinguish foreign DNA from self DNA. Here, we designed an R-M system-mediated genome editing (RMGE) technique for scarless genetic manipulation in different microorganisms. For bacteria with Type IV REase, an RMGE technique using the inducible DNA methyltransferase gene, bceSIIM (RMGE-bceSIIM), as the counter-selection cassette was developed to edit the genome of Escherichia coli. For bacteria without Type IV REase, an RMGE technique based on a restriction endonuclease (RMGE-mcrA) was established in Bacillus subtilis. These techniques were successfully used for gene deletion and replacement with nearly 100% counter-selection efficiencies, which were higher and more stable compared to conventional methods. Furthermore, precise point mutation without limiting sites was achieved in E. coli using RMGE-bceSIIM to introduce a single base mutation of A128C into the rpsL gene. In addition, the RMGE-mcrA technique was applied to delete the CAN1 gene in Saccharomyces cerevisiae DAY414 with 100% counter-selection efficiency. The effectiveness of the RMGE technique in E. coli, B. subtilis, and S. cerevisiae suggests the potential universal usefulness of this technique for microbial genome manipulation.
Carruthers, Katherine H; During, Matthew J; Muravlev, Alexander; Wang, Chuansong; Kocak, Ergun
2013-06-01
The combination of gene therapy and plastic surgery may have the potential to improve the specificity that is needed to achieve clinically applicable treatment regimens. Our goal was to develop a method for gene modification that would yield sustainable production of gene products but would be less time consuming than existing protocols. An adenoassociated virus was used to deliver gene products to pectoralis muscle flaps. Gene modification was accomplished via either direct injection or novel fat grafting techniques. The production of gene product was observable by both in vivo imaging and immunohistochemical staining. Gene products were not detected in tissues that were not in contact with the fat grafts that were incubated with the viral vector, indicating that the transduction stayed local to the flap. Using novel recombinant adenoassociated virus vectors, we have developed a method for gene delivery that is highly efficient and applicable to muscle flaps.
Ion beam modification of zinc white pigment characterized by ex situ and in situ μ-Raman and XPS
NASA Astrophysics Data System (ADS)
Beck, L.; Gutiérrez, P. C.; Miro, S.; Miserque, F.
2017-10-01
Zinc oxide, known as zinc white, is one of the principal white pigments developed in the 18th century and was used by the Impressionist painters. ZnO as artists' pigment has occasionally been characterized by X-ray and ion beam techniques, but these studies are limited by the potential for visible radiation effect. Ion beam modifications of zinc oxide have extensively been investigated, but mainly for electronic and industrial applications. In this paper, we focus our investigation on ion beam modification of ZnO used as pigment. Two irradiation conditions have been used: an external 3 MeV proton micro-beam representative of PIXE analysis and 2 MeV H+ and 1.2 MeV Au + beams in vacuum to investigate irradiation modifications in electronic and nuclear energy loss regimes. Ion beam modification was characterized by ex situ and in situ micro-Raman spectrometry and XPS. The results shows that IBA of zinc white can be carried out safely in historical paintings with low current and dose.
NDE of the space shuttle orbiter thermal protection system: Phase 2 final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tow, D.M.; Barna, B.A.; Rodriguez, J.G.
1989-03-01
Research continued on the development of a nondestructive evaluation technique for inspecting bonds on the space shuttle orbiter thermal protection system tiles. The approach taken uses a noncontacting laser sensor to measure the vibrational response of bonded tiles to acoustical excitation. Laboratory work concentrated on investigating the dynamic response of ''acreage'' tiles, i.e., tiles covering the underside of the orbiter, all approximately square. A number of promising unbond signatures have been identified in the time and frequency domain response. Field tests were conducted to study environmental effects on the techniques being developed. The ambient motion of the orbiter was foundmore » to be larger than expected, necessitating modifications to current techniques. 2 refs., 21 figs., 1 tab.« less
Deaggregation, Modification, and Developing Applications for Detonation Nanodiamond
NASA Astrophysics Data System (ADS)
Mochalin, Vadym
2017-06-01
Nanodiamond powder (ND) is one of the most promising materials for advanced composites and biomedical applications. It is also a commercial precursor for carbon nanoonions - material for high power micrometer size supercapacitors and potentially, Li-ion batteries. ND is produced by detonation of explosives with negative oxygen balance in a closed chamber, where extremely high pressures and temperatures develop during detonation. ND consists of diamond particles of 5 nm diameter, combining fully accessible large surface and rich and tailorable surface chemistry. ND has unique properties including optical, electrical, thermal, and mechanical, and is biocompatible and non-toxic. Due to numerous surface functional groups, ND has catalytic and electrochemical activity. Several techniques have been proposed for ND deaggregation based on milling with costly ceramic microbeads, leaving difficult to remove contaminations in the resulting ND suspension. We have recently discovered a novel, green technique for ND deaggregation using sonication in aqueous sodium chloride slurry. Upon completion of the process sodium chloride can be easily washed out with water leaving behind no contaminants and yielding stable single-digit ND colloids. Modification and development of applications for ND in composites, drug delivery, biomedical imaging, etc., will be also discussed.
UV light induced surface modification of HDPE films with bioactive compounds
NASA Astrophysics Data System (ADS)
Daniloska, Vesna; Blazevska-Gilev, Jadranka; Dimova, Vesna; Fajgar, Radek; Tomovska, Radmila
2010-01-01
The development of different techniques for surface modification of polymers becomes popular in a last decade. These techniques preserve useful bulk polymer properties unchanged, while the activation of the polymer surface offers more possibilities for polymer applications. In this work, a new, one-step method for bio-activation of HDPE (high density polyethylene) surface by UV irradiation is presented. HDPE films coupled with selected active compound and a photoinitiator was treated by UV lamp, emitting light at 254 nm. For surface functionalization of HDPE films, the following compounds were employed: 2-aminopyridine (AP), N 1-(2-pyridylaminomethyl)-1,2,4-triazole (TA) and benzocaine (BC). The influence of irradiation time on the extent of surface changes was investigated. The modified polymer surfaces were investigated by Fourier transformed infrared (FTIR) and Raman spectroscopy, scanning electron microscopy (SEM) and contact angle measurements, demonstrating successful functionalization of HDPE surface.
NASA Astrophysics Data System (ADS)
Leu, Tzong-Shyng; Huang, Hung-Ming; Huang, Ding-Jun
2016-06-01
In this paper, wettability gradient pattern is applied to condensation heat transfer on a copper tube surface. For this application, the vital issue is how to fabricate gradient patterns on a curve tube surface to accelerate the droplet collection efficiently. For this purpose, novel fabrication processes are developed to form wettability gradient patterns on a curve copper tube surface by using roller screen printing surface modification techniques. The roller screen printing surface modification techniques can easily realize wettability gradient surfaces with superhydrophobicity and superhydrophilicity on a copper tube surface. Experimental results show the droplet nucleation sites, movement and coalescence toward the collection areas can be effectively controlled which can assist in removing the condensation water from the surface. The effectiveness of droplet collection is appropriate for being applied to condensation heat transfer in the foreseeable future.
A high level language for a high performance computer
NASA Technical Reports Server (NTRS)
Perrott, R. H.
1978-01-01
The proposed computational aerodynamic facility will join the ranks of the supercomputers due to its architecture and increased execution speed. At present, the languages used to program these supercomputers have been modifications of programming languages which were designed many years ago for sequential machines. A new programming language should be developed based on the techniques which have proved valuable for sequential programming languages and incorporating the algorithmic techniques required for these supercomputers. The design objectives for such a language are outlined.
A basic review on the inferior alveolar nerve block techniques.
Khalil, Hesham
2014-01-01
The inferior alveolar nerve block is the most common injection technique used in dentistry and many modifications of the conventional nerve block have been recently described in the literature. Selecting the best technique by the dentist or surgeon depends on many factors including the success rate and complications related to the selected technique. Dentists should be aware of the available current modifications of the inferior alveolar nerve block techniques in order to effectively choose between these modifications. Some operators may encounter difficulty in identifying the anatomical landmarks which are useful in applying the inferior alveolar nerve block and rely instead on assumptions as to where the needle should be positioned. Such assumptions can lead to failure and the failure rate of inferior alveolar nerve block has been reported to be 20-25% which is considered very high. In this basic review, the anatomical details of the inferior alveolar nerve will be given together with a description of its both conventional and modified blocking techniques; in addition, an overview of the complications which may result from the application of this important technique will be mentioned.
A basic review on the inferior alveolar nerve block techniques
Khalil, Hesham
2014-01-01
The inferior alveolar nerve block is the most common injection technique used in dentistry and many modifications of the conventional nerve block have been recently described in the literature. Selecting the best technique by the dentist or surgeon depends on many factors including the success rate and complications related to the selected technique. Dentists should be aware of the available current modifications of the inferior alveolar nerve block techniques in order to effectively choose between these modifications. Some operators may encounter difficulty in identifying the anatomical landmarks which are useful in applying the inferior alveolar nerve block and rely instead on assumptions as to where the needle should be positioned. Such assumptions can lead to failure and the failure rate of inferior alveolar nerve block has been reported to be 20-25% which is considered very high. In this basic review, the anatomical details of the inferior alveolar nerve will be given together with a description of its both conventional and modified blocking techniques; in addition, an overview of the complications which may result from the application of this important technique will be mentioned. PMID:25886095
Techniques for shuttle trajectory optimization
NASA Technical Reports Server (NTRS)
Edge, E. R.; Shieh, C. J.; Powers, W. F.
1973-01-01
The application of recently developed function-space Davidon-type techniques to the shuttle ascent trajectory optimization problem is discussed along with an investigation of the recently developed PRAXIS algorithm for parameter optimization. At the outset of this analysis, the major deficiency of the function-space algorithms was their potential storage problems. Since most previous analyses of the methods were with relatively low-dimension problems, no storage problems were encountered. However, in shuttle trajectory optimization, storage is a problem, and this problem was handled efficiently. Topics discussed include: the shuttle ascent model and the development of the particular optimization equations; the function-space algorithms; the operation of the algorithm and typical simulations; variable final-time problem considerations; and a modification of Powell's algorithm.
Techniques of laparoscopic cholecystectomy: Nomenclature and selection
Haribhakti, Sanjiv P.; Mistry, Jitendra H.
2015-01-01
There are more than 50 different techniques of laparoscopic cholecystectomy (LC) available in literature mainly due to modifications by surgeons in aim to improve postoperative outcome and cosmesis. These modifications include reduction in port size and/or number than what is used in standard LC. There is no uniform nomenclature to describe these different techniques so that it is not possible to compare the outcomes of different techniques. We brief the advantages and disadvantages of each of these techniques and suggest the situation where particular technique would be useful. We also propose a nomenclature which is easy to remember and apply, so that any future comparison will be possible between the techniques. PMID:25883450
Imaging biofilms in porous media using X-ray computed micro-tomography
NASA Astrophysics Data System (ADS)
Davit, Y.; Debenest, G.; Quintard, M.
2009-12-01
In soils and rivers subsurface, bacterial biofilms growth induce modifications of mass and momentum transport dynamics. Evidence for these modifications have been developed essentially by inspection, that is, observation of the reduction of hydraulic conductivity, permeability, changes in porosity and anomalous transport. Deeper understanding of these sessile communities in porous media environments and of the multiscale/multiphase complexity of the system requires 3-D informations concerning the pore-scale/biofilm-scale geometry. Additionnally, breakthroughs in imaging techniques are likely to trigger breakthroughs in the theoretical analysis. In this study, we develop a new technique for direct observation and imaging of unstrained biofilms in porous media using X-ray computed micro-tomography. The biofilms are grown for ten days on polyamide and expanded polystyrene beads placed in small plastic columns. A circulation of water from the river Garonne (France) is imposed using peristaltic pumps. No particular bacterial strain is introduced, the micro-organisms being naturally present in the water from the river. The X-ray acquisition is performed by a Skyscan-1174 micro-CT. A special experimental technique, based on two different contrast agents, has been designed to solve the challenging problem of imaging 3 phases of initial similar absorption coefficients. On the one hand, we use a suspension of barium sulfate to enhance the contrast of the water-phase. On the other hand, the absorption of the biofilm-phase is increased using iodine which diffuses into the polymeric matrix. Examples of reconstructed images are given to illustrate the effectiveness of the method. We demonstrate how to combine the 3-D measurements with upscaling techniques such as volume averaging, by calculating the modifications of the permeability of the system when biofilms grow. At last, we aim to couple these 3-D measurements with upscaled reactive models to describe the Darcy-scale transport and degradation of contaminants in subsurface zones.
Mass spectrometry: Raw protein from the top down
NASA Astrophysics Data System (ADS)
Breuker, Kathrin
2018-02-01
Mass spectrometry is a powerful technique for analysing proteins, yet linking higher-order protein structure to amino acid sequence and post-translational modifications is far from simple. Now, a native top-down method has been developed that can provide information on higher-order protein structure and different proteoforms at the same time.
Construction and Modification of the Autonomy of School Mathematical Knowledge in Portugal
ERIC Educational Resources Information Center
Matos, José Manuel
2016-01-01
During the second half of the nineteenth century and early twentieth century the discipline of secondary mathematics was gradually built in Portugal and certified teachers, textbooks, programs, special teaching techniques emerge. This consolidation process ends with the emergency of school subjects that develop some kind of autonomy as Chervel…
A study for hypergolic vapor sensor development
NASA Technical Reports Server (NTRS)
Stetter, J. R.; Tellefsen, K.
1977-01-01
In summary, the following tasks were completed within the scope of this work: (1) a portable Monomethylhydrazine analyzer was developed, designed, fabricated and tested. (2) A portable NO2 analyzer was developed, designed, fabricated and tested. (3) Sampling probes and accessories were designed and fabricated for this instrumentation. (4) Improvements and modifications were made to the model 7630 Ecolyzer in preparation for field testing. (5) Instrument calibration procedures and hydrazine handling techniques necessary to the successful application of this hardware were developed.
Sotomayor-González, Arturo; Díaz-Martínez, Armando José; Radillo-Gil, Ramón; García-Estrada, Everardo; Morales-Gómez, Jesús Alberto; Palacios-Ortiz, Isaac Jair; Pérez-Cárdenas, Samuel; Arteaga-Treviño, Mauricio; De León, Ángel Martínez-Ponce
2016-01-01
Objective Report a modification of the “rescue flap” technique using a direct endonasal approach with a partial superior septectomy for approaching pituitary tumors developed in our institution. Design Prospective study. Setting Hospital Universitario “Dr. José Eleuterio González,” Universidad Autónoma de Nuevo León. Main Outcome Measures Since April 2015, we have performed 19 cases employing a direct endonasal approach with partial superior septectomy. Results and a technical note are described below. Results Nineteen patients were included in this report. Six patients presented transoperatory cerebrospinal fluid (CSF) leak, so a nasoseptal rescue flap was harvested. No patients developed postoperative CSF leak in this group. Two patients were submitted to a second surgical procedure. Nasoseptal flap was harvested without complications. In both patients, the size of the flap was enough to cover the dural defect and avoid CSF leak. Conclusion Direct endonasal approach with a partial posterior septectomy allows enough exposition of the sphenoidal sinus while preserving the nasoseptal septum with the possibility of a successful rescue flap when needed. PMID:28321383
Sotomayor-González, Arturo; Díaz-Martínez, Armando José; Radillo-Gil, Ramón; García-Estrada, Everardo; Morales-Gómez, Jesús Alberto; Palacios-Ortiz, Isaac Jair; Pérez-Cárdenas, Samuel; Arteaga-Treviño, Mauricio; De León, Ángel Martínez-Ponce
2017-04-01
Objective Report a modification of the "rescue flap" technique using a direct endonasal approach with a partial superior septectomy for approaching pituitary tumors developed in our institution. Design Prospective study. Setting Hospital Universitario "Dr. José Eleuterio González," Universidad Autónoma de Nuevo León. Main Outcome Measures Since April 2015, we have performed 19 cases employing a direct endonasal approach with partial superior septectomy. Results and a technical note are described below. Results Nineteen patients were included in this report. Six patients presented transoperatory cerebrospinal fluid (CSF) leak, so a nasoseptal rescue flap was harvested. No patients developed postoperative CSF leak in this group. Two patients were submitted to a second surgical procedure. Nasoseptal flap was harvested without complications. In both patients, the size of the flap was enough to cover the dural defect and avoid CSF leak. Conclusion Direct endonasal approach with a partial posterior septectomy allows enough exposition of the sphenoidal sinus while preserving the nasoseptal septum with the possibility of a successful rescue flap when needed.
Research and development of metals for medical devices based on clinical needs
Hanawa, Takao
2012-01-01
The current research and development of metallic materials used for medicine and dentistry is reviewed. First, the general properties required of metals used in medical devices are summarized, followed by the needs for the development of α + β type Ti alloys with large elongation and β type Ti alloys with a low Young's modulus. In addition, nickel-free Ni–Ti alloys and austenitic stainless steels are described. As new topics, we review metals that are bioabsorbable and compatible with magnetic resonance imaging. Surface treatment and modification techniques to improve biofunctions and biocompatibility are categorized, and the related problems are presented at the end of this review. The metal surface may be biofunctionalized by various techniques, such as dry and wet processes. These techniques make it possible to apply metals to scaffolds in tissue engineering. PMID:27877526
Graphic/symbol segmentation for Group 4 facsimile systems
NASA Astrophysics Data System (ADS)
Deutermann, A. R.
1982-04-01
The purpose of this study was to examine possible techniques for and symbol areas, and assemble a code that represents the entire document. Parameters to be considered include compression, commonality with facsimile and TELETEX* transmissions, and complexity of implementation. Six segmentation technique were selected for analysis. The techniques were designed to differ from each other as much as possible, so as to display a wide variety of characteristics. For each technique, many minor modifications would be possible, but it is not expected that these modifications would alter the conclusions drawn from the study.
Haglund, Ulf H; Norén, Agneta; Urdzik, Jozef; Duraj, Frans F
2008-07-01
A right hemihepatectomy is frequently required for surgical removal of colorectal liver metastases. Today, this procedure can be performed quite safely provided the remaining liver is free from significant disease including steatohepatitis due to prolonged cytostatic treatment. Standard surgical techniques for liver resection are described in surgical textbooks. However, each center has developed its own modifications of important details. In this paper, we describe our technique to resect the right liver lobe using conventional surgical techniques as well as a vascular stapler and an ultrasonic dissector. This technique has proven to be quite safe, and blood loss is most often not significant despite we do not routinely apply the Pringle's manoeuvre during the division of the liver parenchyma.
Laboratory for Atmospheres: Instrument Systems Report
NASA Technical Reports Server (NTRS)
2011-01-01
Studies of the atmospheres of our solar system's planets including our own require a comprehensive set of observations, relying on instruments on spacecraft, aircraft, balloons, and on the surface. Laboratory personnel define requirements, conceive concepts, and develop instrument systems for spaceflight missions, and for balloon, aircraft, and ground-based observations. Laboratory scientists also participate in the design of data processing algorithms, calibration techniques, and data processing systems. The instrument sections of this report are organized by measurement technique: lidar, passive, in situ and microwave. A number of instruments in various stages of development or modification are also described. This report will be updated as instruments evolve.
Treating Retentive Encopresis: Dietary Modification and Behavioral Techniques.
ERIC Educational Resources Information Center
Nabors, Laura; Morgan, Sam B.
1995-01-01
A home-based contingency management program, consisting of diet modification, laxatives, correction for soiling accidents, stimulus control training, and positive reinforcement, was implemented for treatment of a 4-year-old encopretic male. The findings provide evidence supporting the effectiveness of dietary modification combined with behavior…
The double stapling technique for low anterior resection. Results, modifications, and observations.
Griffen, F D; Knight, C D; Whitaker, J M; Knight, C D
1990-01-01
Since the introduction of the end-to-end anastomosis (EEA) stapler for rectal reconstruction, we have used a modification of the conventional technique in which the lower rectal segment is closed with the linear stapler (TA-55) and the anastomosis is performed using the EEA instrument across the linear staple line (double stapling technique). Our experience with this procedure includes stapled colorectal anastomoses in 75 patients and is the basis for the report. This review presents the details and advantages of the technique and the results. Complications include two patients with anastomotic leak (2.7%), and two with stenosis that required treatment (2.7%). Protective colostomy was not done in this series. There were no deaths. Our experience and that of others suggests that this modification of the EEA technique can allow a lower anastomosis in some patients, and that it can be done with greater safety and facility. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PMID:2357137
Foda, Abd Al-Rahman Mohammad
2013-05-01
Manual tissue microarray (TMA) construction had been introduced to avoid the high cost of automated and semiautomated techniques. The cheapest and simplest technique for constructing manual TMA was that of using mechanical pencil tips. This study was carried out to modify this method, aiming to raise its quality to reach that of expensive ones. Some modifications were introduced to Shebl's technique. Two conventional mechanical pencil tips of different diameters were used to construct the recipient blocks. A source of mild heat was used, and blocks were incubated at 38°C overnight. With our modifications, 3 high-density TMA blocks were constructed. We successfully performed immunostaining without substantial tissue loss. Our modifications increased the number of cores per block and improved the stability of the cores within the paraffin block. This new, modified technique is a good alternative for expensive machines in many laboratories.
Structural analyses for the modification and verification of the Viking aeroshell
NASA Technical Reports Server (NTRS)
Stephens, W. B.; Anderson, M. S.
1976-01-01
The Viking aeroshell is an extremely lightweight flexible shell structure that has undergone thorough buckling analyses in the course of its development. The analytical tools and modeling technique required to reveal the structural behavior are presented. Significant results are given which illustrate the complex failure modes not usually observed in simple models and analyses. Both shell-of-revolution analysis for the pressure loads and thermal loads during entry and a general shell analysis for concentrated tank loads during launch were used. In many cases fixes or alterations to the structure were required, and the role of the analytical results in determining these modifications is indicated.
Bodison, Stefanie C; Parham, L Diane
This systematic review examined the effectiveness of specific sensory techniques and sensory environmental modifications to improve participation of children with sensory integration (SI) difficulties. Abstracts of 11,436 articles published between January 2007 and May 2015 were examined. Studies were included if designs reflected high levels of evidence, participants demonstrated SI difficulties, and outcome measures addressed function or participation. Eight studies met inclusion criteria. Seven studies evaluated effects of specific sensory techniques for children with autism spectrum disorder (ASD) or attention deficit hyperactivity disorder: Qigong massage, weighted vests, slow swinging, and incorporation of multisensory activities into preschool routines. One study of sensory environmental modifications examined adaptations to a dental clinic for children with ASD. Strong evidence supported Qigong massage, moderate evidence supported sensory modifications to the dental care environment, and limited evidence supported weighted vests. The evidence is insufficient to draw conclusions regarding slow linear swinging and incorporation of multisensory activities into preschool settings. Copyright © 2018 by the American Occupational Therapy Association, Inc.
Fingerprinting of music scores
NASA Astrophysics Data System (ADS)
Irons, Jonathan; Schmucker, Martin
2004-06-01
Publishers of sheet music are generally reluctant in distributing their content via the Internet. Although online sheet music distribution's advantages are numerous the potential risk of Intellectual Property Rights (IPR) infringement, e.g. illegal online distributions, disables any innovation propensity. While active protection techniques only deter external risk factors, additional technology is necessary to adequately treat further risk factors. For several media types including music scores watermarking technology has been developed, which ebeds information in data by suitable data modifications. Furthermore, fingerprinting or perceptual hasing methods have been developed and are being applied especially for audio. These methods allow the identification of content without prior modifications. In this article we motivate the development of watermarking and fingerprinting technologies for sheet music. Outgoing from potential limitations of watermarking methods we explain why fingerprinting methods are important for sheet music and address potential applications. Finally we introduce a condept for fingerprinting of sheet music.
Local dynamic range compensation for scanning electron microscope imaging system.
Sim, K S; Huang, Y H
2015-01-01
This is the extended project by introducing the modified dynamic range histogram modification (MDRHM) and is presented in this paper. This technique is used to enhance the scanning electron microscope (SEM) imaging system. By comparing with the conventional histogram modification compensators, this technique utilizes histogram profiling by extending the dynamic range of each tile of an image to the limit of 0-255 range while retains its histogram shape. The proposed technique yields better image compensation compared to conventional methods. © Wiley Periodicals, Inc.
Plasmonic improvement of microcavity biomedical sensor spectroscopic characteristics
NASA Astrophysics Data System (ADS)
Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas; Ghadiri, Reza
2014-03-01
New opportunity to improve a sensetivity of a label-free biomolecule detection in sensing systems based on microcavity evanescent wave optical sensors has been recently found and is being under intensive development. Novel technique based on combination of optical resonance on microring structures with plasmon resonance. Recently developed tools based on neural network data processing can realize real-time identification of biological agents. So combining advantages of plasmon enhancing optical microcavity resonance with identification tools can give a new platform for ulta sensitive label-free biomedical sensor. Our developed technique used standard glass and polymer microspheres as sensetive elements. They are fixed in the solution flow by adhesive layer on the surface being in the field of evanescence wave. Sensitive layer have been treated by gold nanoparticel (GN) solution. Another technique used thin film gold layers deposited on the substrate below adhesive. The light from a tuneable diode laser is coupled into the microsphere through a prism and was sharply focussed on the single microsphere. Images were recorded by CMOS camera. Normalized by free spectral range resonance shift of whispering gallery mode (WGM) and a relative efficiency of their excitation were used as input data for biomolecule classification. Both biomolecules and NP injection was obtained caused WGM spectra modification. But after NP treatment spectral shift and intensity of WGM resonances in biomolecule solutions increased. WGM resonances in microspheres fixed on substrate with gold layer with optimized layer thickness in biomolecule solutions also had higher intensity and spectra modification then without gold layer.
Public perceptions of hurricane modification.
Klima, Kelly; Bruine de Bruin, Wändi; Morgan, M Granger; Grossmann, Iris
2012-07-01
If hurricane modification were to become a feasible strategy for potentially reducing hurricane damages, it would likely generate public discourse about whether to support its implementation. To facilitate an informed and constructive discourse, policymakers need to understand how people perceive hurricane modification. Here, we examine Florida residents' perceptions of hurricane modification techniques that aim to alter path and wind speed. Following the mental models approach, we conducted a survey study about public perceptions of hurricane modification that was guided by formative interviews on the topic. We report a set of four primary findings. First, hurricane modification was perceived as a relatively ineffective strategy for damage reduction, compared to other strategies for damage reduction. Second, hurricane modification was expected to lead to changes in projected hurricane path, but not necessarily to the successful reduction of projected hurricane strength. Third, more anger was evoked when a hurricane was described as having changed from the initially forecasted path or strength after an attempted modification. Fourth, unlike what we expected, participants who more strongly agreed with statements that recognized the uncertainty inherent in forecasts reported more rather than less anger at scientists across hurricane modification scenarios. If the efficacy of intensity-reduction techniques can be increased, people may be willing to support hurricane modification. However, such an effort would need to be combined with open and honest communications to members of the general public. © 2011 Society for Risk Analysis.
Technical guide to crop tree release in hardwood forests
Gary W. Miller; Jeffrey W. Stringer; David C. Mercker
2007-01-01
Crop tree release (CTR) is a widely applicable silvicultural technique used to enhance the performance of individual trees. It offers flexibility in that it can be applied on small or large properties, and with certain modifications, it can be applied as a precommercial or commercial operation. By favoring the development of selected crop trees within a hardwood stand...
Developing Parenting Skills through Health Visitors: Preliminary Results from an Evaluation Study.
ERIC Educational Resources Information Center
Stevenson, Jim
Preliminary results of a study of the extent to which training health visitors in behavior modification techniques improves the effectiveness of their work with families of young children are presented. A total of 14 health visitors were recruited and assigned to training and delay-of-training groups. Selected from case loads, participating…
NASA Technical Reports Server (NTRS)
1972-01-01
A selection of new hand tools, modifications of existing tools, and techniques developed in the course of NASA research and development projects are presented. The items are presented in two sections: tools for cable and connector applications, and tools for welding applications. Safety is emphasized, together with ease of operation and use in restricted areas or hazardous environments. The discussions are directed primarily toward the technician engaged in assembly or maintenance of mechanical or electrical equipment.
Laser hardening techniques on steam turbine blade and application
NASA Astrophysics Data System (ADS)
Yao, Jianhua; Zhang, Qunli; Kong, Fanzhi; Ding, Qingming
Different laser surface hardening techniques, such as laser alloying and laser solution strengthening were adopted to perform modification treatment on the local region of inset edge for 2Cr13 and 17-4PH steam turbine blades to prolong the life of the blades. The microstructures, microhardness and anti-cavitation properties were investigated on the blades after laser treatment. The hardening mechanism and technique adaptability were researched. Large scale installation practices confirmed that the laser surface modification techniques are safe and reliable, which can improve the properties of blades greatly with advantages of high automation, high quality, little distortion and simple procedure.
Microneedle Coating Techniques for Transdermal Drug Delivery
Haj-Ahmad, Rita; Khan, Hashim; Arshad, Muhammad Sohail; Rasekh, Manoochehr; Hussain, Amjad; Walsh, Susannah; Li, Xiang; Chang, Ming-Wei; Ahmad, Zeeshan
2015-01-01
Drug administration via the transdermal route is an evolving field that provides an alternative to oral and parenteral routes of therapy. Several microneedle (MN) based approaches have been developed. Among these, coated MNs (typically where drug is deposited on MN tips) are a minimally invasive method to deliver drugs and vaccines through the skin. In this review, we describe several processes to coat MNs. These include dip coating, gas jet drying, spray coating, electrohydrodynamic atomisation (EHDA) based processes and piezoelectric inkjet printing. Examples of process mechanisms, conditions and tested formulations are provided. As these processes are independent techniques, modifications to facilitate MN coatings are elucidated. In summary, the outcomes and potential value for each technique provides opportunities to overcome formulation or dosage form limitations. While there are significant developments in solid degradable MNs, coated MNs (through the various techniques described) have potential to be utilized in personalized drug delivery via controlled deposition onto MN templates. PMID:26556364
Evaluation of Mesoscale Model Phenomenological Verification Techniques
NASA Technical Reports Server (NTRS)
Lambert, Winifred
2006-01-01
Forecasters at the Spaceflight Meteorology Group, 45th Weather Squadron, and National Weather Service in Melbourne, FL use mesoscale numerical weather prediction model output in creating their operational forecasts. These models aid in forecasting weather phenomena that could compromise the safety of launch, landing, and daily ground operations and must produce reasonable weather forecasts in order for their output to be useful in operations. Considering the importance of model forecasts to operations, their accuracy in forecasting critical weather phenomena must be verified to determine their usefulness. The currently-used traditional verification techniques involve an objective point-by-point comparison of model output and observations valid at the same time and location. The resulting statistics can unfairly penalize high-resolution models that make realistic forecasts of a certain phenomena, but are offset from the observations in small time and/or space increments. Manual subjective verification can provide a more valid representation of model performance, but is time-consuming and prone to personal biases. An objective technique that verifies specific meteorological phenomena, much in the way a human would in a subjective evaluation, would likely produce a more realistic assessment of model performance. Such techniques are being developed in the research community. The Applied Meteorology Unit (AMU) was tasked to conduct a literature search to identify phenomenological verification techniques being developed, determine if any are ready to use operationally, and outline the steps needed to implement any operationally-ready techniques into the Advanced Weather Information Processing System (AWIPS). The AMU conducted a search of all literature on the topic of phenomenological-based mesoscale model verification techniques and found 10 different techniques in various stages of development. Six of the techniques were developed to verify precipitation forecasts, one to verify sea breeze forecasts, and three were capable of verifying several phenomena. The AMU also determined the feasibility of transitioning each technique into operations and rated the operational capability of each technique on a subjective 1-10 scale: (1) 1 indicates that the technique is only in the initial stages of development, (2) 2-5 indicates that the technique is still undergoing modifications and is not ready for operations, (3) 6-8 indicates a higher probability of integrating the technique into AWIPS with code modifications, and (4) 9-10 indicates that the technique was created for AWIPS and is ready for implementation. Eight of the techniques were assigned a rating of 5 or below. The other two received ratings of 6 and 7, and none of the techniques a rating of 9-10. At the current time, there are no phenomenological model verification techniques ready for operational use. However, several of the techniques described in this report may become viable techniques in the future and should be monitored for updates in the literature. The desire to use a phenomenological verification technique is widespread in the modeling community, and it is likely that other techniques besides those described herein are being developed, but the work has not yet been published. Therefore, the AMIU recommends that the literature continue to be monitored for updates to the techniques described in this report and for new techniques being developed whose results have not yet been published. 111
ERIC Educational Resources Information Center
Starling, Julia; Munro, Natalie; Togher, Leanne; Arciuli, Joanne
2012-01-01
Purpose: This study evaluated the efficacy of a collaborative intervention where a speech-language pathologist (SLP) trained mainstream secondary school teachers to make modifications to their oral and written instructional language. The trained teachers' uptake of techniques in their whole-class teaching practices and the impact this had on the…
ERIC Educational Resources Information Center
New York State Commission on Quality of Care for the Mentally Disabled, Albany.
This report examines issues concerned with the use of aversive behavior modification techniques in actual treatment practices at one intermediate care facility for the mentally retarded. The review of these practices reveals how, once the philosophy of using aversives takes hold at a program (to deal with seemingly intractable behaviors), its…
William E. Taylor; Robert G. Hooper
1991-01-01
A modification to Copeyon's drilling technique for making highly effective artificial cavities for red-cockaded wookpeckers is described.The changes virtually eliminate the possibility of making a mistake in constructing cavities and reduces the learning time to less than 2 weeks.The basic change is the use of a 3-inch access hole that allows the relative position...
NASA Technical Reports Server (NTRS)
Manford, J. S.; Bennett, G. R.
1985-01-01
The Space Station Program will incorporate analysis of operations constraints and considerations in the early design phases to avoid the need for later modifications to the Space Station for operations. The application of modern tools and administrative techniques to minimize the cost of performing effective orbital operations planning and design analysis in the preliminary design phase of the Space Station Program is discussed. Tools and techniques discussed include: approach for rigorous analysis of operations functions, use of the resources of a large computer network, and providing for efficient research and access to information.
NASA Technical Reports Server (NTRS)
Kibler, J. F.; Green, R. N.; Young, G. R.; Kelly, M. G.
1974-01-01
A method has previously been developed to satisfy terminal rendezvous and intermediate timing constraints for planetary missions involving orbital operations. The method uses impulse factoring in which a two-impulse transfer is divided into three or four impulses which add one or two intermediate orbits. The periods of the intermediate orbits and the number of revolutions in each orbit are varied to satisfy timing constraints. Techniques are developed to retarget the orbital transfer in the presence of orbit-determination and maneuver-execution errors. Sample results indicate that the nominal transfer can be retargeted with little change in either the magnitude (Delta V) or location of the individual impulses. Additonally, the total Delta V required for the retargeted transfer is little different from that required for the nominal transfer. A digital computer program developed to implement the techniques is described.
Modifications Of Hydrostatic-Bearing Computer Program
NASA Technical Reports Server (NTRS)
Hibbs, Robert I., Jr.; Beatty, Robert F.
1991-01-01
Several modifications made to enhance utility of HBEAR, computer program for analysis and design of hydrostatic bearings. Modifications make program applicable to more realistic cases and reduce time and effort necessary to arrive at a suitable design. Uses search technique to iterate on size of orifice to obtain required pressure ratio.
Aircraft propeller induced structure-borne noise
NASA Technical Reports Server (NTRS)
Unruh, James F.
1989-01-01
A laboratory-based test apparatus employing components typical of aircraft construction was developed that would allow the study of structure-borne noise transmission due to propeller induced wake/vortex excitation of in-wake structural appendages. The test apparatus was employed to evaluate several aircraft installation effects (power plant placement, engine/nacelle mass loading, and wing/fuselage attachment methods) and several structural response modifications for structure-borne noise control (the use of wing blocking mass/fuel, wing damping treaments, and tuned mechanical dampers). Most important was the development of in-flight structure-borne noise transmission detection techniques using a combination of ground-based frequency response function testing and in-flight structural response measurement. Propeller wake/vortex excitation simulation techniques for improved ground-based testing were also developed to support the in-flight structure-borne noise transmission detection development.
Grover, Davinder S; Fellman, Ronald L
2016-06-01
To describe a novel technique for thermally marking the tip of a suture, in preparation for a gonioscopy-assisted transluminal trabeculotomy. One patient was used as an example for this technique. Technique report. The authors introduce a modification of a novel surgical procedure (GATT) in which a suture is marked and thermally blunted allowing a proper visualization while performing an ab interno, minimally invasive, circumferential 360-degree suture trabeculotomy. The authors have previously reported on the GATT surgery with the use of an illuminated microcatheter, which allowed for visualization of the tip of the catheter as it circumnavigated Schlemm canal. This modification allows for similar visualization of the tip of the suture, however, is much more cost-effective while still maintaining similar safety.
Mahjoubi, Hesameddin; Kinsella, Joseph M; Murshed, Monzur; Cerruti, Marta
2014-07-09
Scaffolds made with synthetic polymers such as polyesters are commonly used in bone tissue engineering. However, their hydrophobicity and the lack of specific functionalities make their surface not ideal for cell adhesion and growth. Surface modification of these materials is thus crucial to enhance the scaffold's integration in the body. Different surface modification techniques have been developed to improve scaffold biocompatibility. Here we show that diazonium chemistry can be used to modify the outer and inner surfaces of three-dimensional poly(D,L-lactic acid) (PDLLA) scaffolds with phosphonate groups, using a simple two-step method. By changing reaction time and impregnation procedure, we were able to tune the concentration of phosphonate groups present on the scaffolds, without degrading the PDLLA matrix. To test the effectiveness of this modification, we immersed the scaffolds in simulated body fluid, and characterized them with scanning electron microscopy, X-ray photoelectron spectroscopy, Raman, and infrared spectroscopy. Our results showed that a layer of hydroxyapatite particles was formed on all scaffolds after 2 and 4 weeks of immersion; however, the precipitation was faster and in larger amounts on the phosphonate-modified than on the bare PDLLA scaffolds. Both osteogenic MC3T3-E1 and chondrogenic ATDC5 cell lines showed increased cell viability/metabolic activity when grown on a phosphonated PDLLA surface in comparison to a control PDLLA surface. Also, more calcium-containing minerals were deposited by cultures grown on phosphonated PDLLA, thus showing the pro-mineralization properties of the proposed modification. This work introduces diazonium chemistry as a simple and biocompatible technique to modify scaffold surfaces, allowing to covalently and homogeneously bind a number of functional groups without degrading the scaffold's polymeric matrix.
Surface modification of polymers for biocompatibility via exposure to extreme ultraviolet radiation.
Inam Ul Ahad; Bartnik, Andrzej; Fiedorowicz, Henryk; Kostecki, Jerzy; Korczyc, Barbara; Ciach, Tomasz; Brabazon, Dermot
2014-09-01
Polymeric biomaterials are being widely used for the treatment of various traumata, diseases and defects in human beings due to ease in their synthesis. As biomaterials have direct interaction with the extracellular environment in the biological world, biocompatibility is a topic of great significance. The introduction or enhancement of biocompatibility in certain polymers is still a challenge to overcome. Polymer biocompatibility can be controlled by surface modification. Various physical and chemical methods (e.g., chemical and plasma treatment, ion implantation, and ultraviolet irradiation etc.) are in use or being developed for the modification of polymer surfaces. However an important limitation in their employment is the alteration of bulk material. Different surface and bulk properties of biomaterials are often desirable for biomedical applications. Because extreme ultraviolet (EUV) radiation penetration is quite limited even in low density mediums, it could be possible to use it for surface modification without influencing the bulk material. This article reviews the degree of biocompatibility of different polymeric biomaterials being currently employed in various biomedical applications, the surface properties required to be modified for biocompatibility control, plasma and laser ablation based surface modification techniques, and research studies indicating possible use of EUV for enhancing biocompatibility. © 2013 Wiley Periodicals, Inc.
A new technique for Gram staining paraffin-embedded tissue.
Engbaek, K; Johansen, K S; Jensen, M E
1979-01-01
Five techniques for Gram staining bacteria in paraffin sections were compared on serial sections of pulmonary tissues from eight bacteriological necropsies. Brown and Hopp's method was the most satisfactory for distinguishing Gram-positive and Gram-negative bacteria. However, this method cannot be recommended as the preparations were frequently overstained, and the Gram-negative bacteria were stained indistinctly. A modification of Brown and Hopps' method was developed which stains larger numbers of Gram-negative bacteria and differentiates well between different cell types and connective tissue, and there is no risk of overstaining. PMID:86548
Measurements of hydrogen gas stopping efficiency for tin ions from laser-produced plasma
NASA Astrophysics Data System (ADS)
Abramenko, D. B.; Spiridonov, M. V.; Krainov, P. V.; Krivtsun, V. M.; Astakhov, D. I.; Medvedev, V. V.; van Kampen, M.; Smeets, D.; Koshelev, K. N.
2018-04-01
Experimental studies of stopping of ion fluxes from laser-produced plasma by a low-pressure gas atmosphere are presented. A modification of the time-of-flight spectroscopy technique is proposed for the stopping cross-sectional measurements in the ion energy range of 0.1-10 keV. The application of the proposed technique is demonstrated for Sn ion stopping by H2 gas. This combination of elements is of particular importance for the development of plasma-based sources of extreme ultraviolet radiation for lithographic applications.
A Novel Surgical Technique for Ahmed Valves in Refractory Glaucoma With Silicone Oil Endotamponade.
Davo-Cabrera, Juan Maria; Lanzagorta-Aresti, Aitor; Alcocer Yuste, Pablo
2017-10-01
The purpose of the study is to describe a novel technique to implant Ahmed valves in patients with refractory glaucoma because of silicone oil (SO) endotamponade PATIENTS:: Three patients with glaucoma without SO removal were used as an example for this technique. Technique report. We introduce a standard technique modification for Ahmed valves in patients with SO. This modification consists on locating the Ahmed valve more tangential to the limbus curvature instead of the usual perpendicular position and inserting the tube in the posterior chamber. The tube can be longer and run parallel to pupil. This technique allows use superotemporal quadrant (fewer complications), avoid corneal touch and decrease SO loss through the tube to subconjunctival space.
Christodoulou, Asterios; Mikrogeorgis, Georgios; Vouzara, Triantafillia; Papachristou, Konstantinos; Angelopoulos, Christos; Nikolaidis, Nikolaos; Pitas, Ioannis; Lyroudia, Kleoniki
2018-02-15
In this study, the three-dimensional (3D) modification of root canal curvature was measured, after the application of Reciproc instrumentation technique, by using cone beam computed tomography (CBCT) imaging and a special algorithm developed for the 3D measurement of the curvature of the root canal. Thirty extracted upper molars were selected. Digital radiographs for each tooth were taken. Root curvature was measured by using Schneider method and they were divided into three groups, each one consisting of 10 roots, according to their curvature: Group 1 (0°-20°), Group 2 (21°-40°), Group 3 (41°-60°). CBCT imaging was applied to each tooth before and after its instrumentation, and the data were examined by using a specially developed CBCT image analysis algorithm. The instrumentation with Reciproc led to a decrease of the curvature by 30.23% (on average) in all groups. The proposed methodology proved to be able to measure the curvature of the root canal and its 3D modification after the instrumentation.
Research on dental implant and its industrialization stage
NASA Astrophysics Data System (ADS)
Dongjoon, Yang; Sukyoung, Kim
2017-02-01
Bone cell attachment to Ti implant surfaces is the most concerned issue in the clinical implant dentistry. Many attempts to achieve the fast and strong integration between bone and implant have been tried in many ways, such as selection of materials (for example, Ti, ZrO2), shape design of implant (for example, soft tissue level, bone level, taped or conical, etc), and surface modification of implants (for example, roughed. coated, hybrid), etc. Among them, a major consideration is the surface design of dental implants. The surface with proper structural characteristics promotes or induces the desirable responses of cells and tissues. To obtain such surface which has desirable cell and tissue response, a variety of surface modification techniques has been developed and employed for many years. In this review, the method and trend of surface modification will be introduced and explained in terms of the surface topography and chemistry of dental implants.
The effects of leading edge modifications on the post-stall characteristics of wings
NASA Technical Reports Server (NTRS)
Winkelmann, A. E.; Barlow, J. B.; Saini, J. K.; Anderson, J. D., Jr.; Jones, E.
1980-01-01
An investigation of the effects of leading edge modifications on the post-stall characteristics of two rectangular planform wings in a series of low speed wind tunnel tests is presented. Abrupt discontinuities in the leading edge shape of the wings were produced by placing a nose glove over a portion of the span or by deflecting sections of a segmented leading edge flap. Six component balance data, oil flow visualization photographs, and pressure distribution measurements were obtained, and tests made to study the development of flow separation at stall on small scale planform wing models. Results of oil flow visualization tests at and beyond stall showed the formation of counter-rotating swirl patterns on the upper surface of the '2-D' and '3-D' wings, and results of a numerical lifting line technique applied to wings with leading edge modifications are included.
Ruiz-García, Leonor; Cabezas, Jose Antonio; de María, Nuria; Cervera, María-Teresa
2010-01-01
Different molecular techniques have been developed to study either the global level of methylated cytosines or methylation at specific gene sequences. One of them is a modification of the Amplified Fragment Length Polymorphism (AFLP) technique that has been used to study methylation of anonymous CCGG sequences in different fungi, plant and animal species. The main variation of this technique is based on the use of isoschizomers with different methylation sensitivity (such as HpaII and MspI) as a frequent cutter restriction enzyme. For each sample, AFLP analysis is performed using both EcoRI/HpaII and EcoRI/MspI digested samples. Comparative analysis between EcoRI/HpaII and EcoRI/MspI fragment patterns allows the identification of two types of polymorphisms: (1) "Methylation-insensitive polymorphisms" that show common EcoRI/HpaII and EcoRI/MspI patterns but are detected as polymorphic amplified fragments among samples; and (2) "Methylation-sensitive polymorphisms" that are associated with amplified fragments differing in their presence or absence or in their intensity between EcoRI/HpaII and EcoRI/MspI patterns. This chapter describes a detailed protocol of this technique and discusses modifications that can be applied to adjust the technology to different species of interest.
Guevara, María Ángeles; de María, Nuria; Sáez-Laguna, Enrique; Vélez, María Dolores; Cervera, María Teresa; Cabezas, José Antonio
2017-01-01
Different molecular techniques have been developed to study either the global level of methylated cytosines or methylation at specific gene sequences. One of them is the methylation-sensitive amplified polymorphism technique (MSAP) which is a modification of amplified fragment length polymorphism (AFLP). It has been used to study methylation of anonymous CCGG sequences in different fungi, plants, and animal species. The main variation of this technique resides on the use of isoschizomers with different methylation sensitivity (such as HpaII and MspI) as a frequent-cutter restriction enzyme. For each sample, MSAP analysis is performed using both EcoRI/HpaII- and EcoRI/MspI-digested samples. A comparative analysis between EcoRI/HpaII and EcoRI/MspI fragment patterns allows the identification of two types of polymorphisms: (1) methylation-insensitive polymorphisms that show common EcoRI/HpaII and EcoRI/MspI patterns but are detected as polymorphic amplified fragments among samples and (2) methylation-sensitive polymorphisms which are associated with the amplified fragments that differ in their presence or absence or in their intensity between EcoRI/HpaII and EcoRI/MspI patterns. This chapter describes a detailed protocol of this technique and discusses the modifications that can be applied to adjust the technology to different species of interest.
Intraluminal pressure response in Baerveldt tube shunts: a comparison of modification techniques.
Gilbert, David D; Bond, Brent
2007-01-01
To design an apparatus for in vitro quantification of effects of modifications to nonvalved tube shunts, and to compare the effects of these modifications done to prevent early postoperative hypotony. A testing apparatus was designed and constructed to measure intraluminal pressure (ILP) during constant infusion of balanced salt solution at 2 microL/min through Baerveldt tube shunts mounted on cadaver eyes. Three different modifications were performed and 3 shunts were used for each modification. The modifications were partial tube occlusion with a 3-0 Supramid suture, tube perforation with a 27-gauge needle on an occluded tube, and a 1.2 mm longitudinal venting slit on an occluded tube. The final steady state ILP for the 3-0 Supramid partially occluded tube ranged between 1.6 and 2.8 mm Hg over 3 trials with an average final steady state ILP of 2.0 mm Hg. The 27-gauge needle perforation produced ILPs of 4.6 to 8.2 mm Hg over 3 trials with an average final steady state pressure of 5.9 mm Hg. The 1.2 mm longitudinal venting slit produced an ILP range of 12.6 to 17.3 mm Hg over 3 trials with an average final steady state ILP of 14.8 mm Hg. The differences in final steady state ILP between the 3 modification techniques were statistically significant (P=0.00036). The 3-0 Supramid occlusion and the 27-gauge perforation techniques produced hypotony, whereas the 1.2 mm longitudinal venting slit produced acceptable pressures in vitro.
New computational tools for H/D determination in macromolecular structures from neutron data.
Siliqi, Dritan; Caliandro, Rocco; Carrozzini, Benedetta; Cascarano, Giovanni Luca; Mazzone, Annamaria
2010-11-01
Two new computational methods dedicated to neutron crystallography, called n-FreeLunch and DNDM-NDM, have been developed and successfully tested. The aim in developing these methods is to determine hydrogen and deuterium positions in macromolecular structures by using information from neutron density maps. Of particular interest is resolving cases in which the geometrically predicted hydrogen or deuterium positions are ambiguous. The methods are an evolution of approaches that are already applied in X-ray crystallography: extrapolation beyond the observed resolution (known as the FreeLunch procedure) and a difference electron-density modification (DEDM) technique combined with the electron-density modification (EDM) tool (known as DEDM-EDM). It is shown that the two methods are complementary to each other and are effective in finding the positions of H and D atoms in neutron density maps.
MRAC Control with Prior Model Knowledge for Asymmetric Damaged Aircraft
Zhang, Jing
2015-01-01
This paper develops a novel state-tracking multivariable model reference adaptive control (MRAC) technique utilizing prior knowledge of plant models to recover control performance of an asymmetric structural damaged aircraft. A modification of linear model representation is given. With prior knowledge on structural damage, a polytope linear parameter varying (LPV) model is derived to cover all concerned damage conditions. An MRAC method is developed for the polytope model, of which the stability and asymptotic error convergence are theoretically proved. The proposed technique reduces the number of parameters to be adapted and thus decreases computational cost and requires less input information. The method is validated by simulations on NASA generic transport model (GTM) with damage. PMID:26180839
NASA Technical Reports Server (NTRS)
Soeder, J. F.
1983-01-01
As turbofan engines become more complex, the development of controls necessitate the use of multivariable control techniques. A control developed for the F100-PW-100(3) turbofan engine by using linear quadratic regulator theory and other modern multivariable control synthesis techniques is described. The assembly language implementation of this control on an SEL 810B minicomputer is described. This implementation was then evaluated by using a real-time hybrid simulation of the engine. The control software was modified to run with a real engine. These modifications, in the form of sensor and actuator failure checks and control executive sequencing, are discussed. Finally recommendations for control software implementations are presented.
Refractive index change mechanisms in different glasses induced by femtosecond laser irradiation
NASA Astrophysics Data System (ADS)
Fuerbach, A.; Gross, S.; Little, D.; Arriola, A.; Ams, M.; Dekker, P.; Withford, M.
2016-07-01
Tightly focused femtosecond laser pulses can be used to alter the refractive index of virtually all optical glasses. As the laser-induced modification is spatially limited to the focal volume of the writing beam, this technique enables the fabrication of fully three-dimensional photonic structures and devices that are automatically embedded within the host material. While it is well understood that the laser-material interaction process is initiated by nonlinear, typically multiphoton absorption, the actual mechanism that results in an increase or sometimes decrease of the refractive index of the glass strongly depends on the composition of the material and the process parameters and is still subject to scientific studies. In this paper, we present an overview of our recent work aimed at uncovering the physical and chemical processes that contribute to the observed material modification. Raman microscopy and electron microprobe analysis was used to study the induced modifications that occur within the glass matrix and the influence of atomic species migration forced by the femtosecond laser writing beam. In particular, we concentrate on borosilicate, heavy metal fluoride and phosphate glasses. We believe that our results represent an important step towards the development of engineered glass types that are ideally suited for the fabrication of photonic devices via the femtosecond laser direct write technique.
Memory management and compiler support for rapid recovery from failures in computer systems
NASA Technical Reports Server (NTRS)
Fuchs, W. K.
1991-01-01
This paper describes recent developments in the use of memory management and compiler technology to support rapid recovery from failures in computer systems. The techniques described include cache coherence protocols for user transparent checkpointing in multiprocessor systems, compiler-based checkpoint placement, compiler-based code modification for multiple instruction retry, and forward recovery in distributed systems utilizing optimistic execution.
Chromatin immunoprecipitation of mouse embryos.
Voss, Anne K; Dixon, Mathew P; McLennan, Tamara; Kueh, Andrew J; Thomas, Tim
2012-01-01
During prenatal development, a large number of different cell types are formed, the vast majority of which contain identical genetic material. The basis of the great variety in cell phenotype and function is the differential expression of the approximately 25,000 genes in the mammalian genome. Transcriptional activity is regulated at many levels by proteins, including members of the basal transcriptional apparatus, DNA-binding transcription factors, and chromatin-binding proteins. Importantly, chromatin structure dictates the availability of a specific genomic locus for transcriptional activation as well as the efficiency, with which transcription can occur. Chromatin immunoprecipitation (ChIP) is a method to assess if chromatin modifications or proteins are present at a specific locus. ChIP involves the cross linking of DNA and associated proteins and immunoprecipitation using specific antibodies to DNA-associated proteins followed by examination of the co-precipitated DNA sequences or proteins. In the last few years, ChIP has become an essential technique for scientists studying transcriptional regulation and chromatin structure. Using ChIP on mouse embryos, we can document the presence or absence of specific proteins and chromatin modifications at genomic loci in vivo during mammalian development. Here, we describe a ChIP technique adapted for mouse embryos.
Genetic engineering including superseding microinjection: new ways to make GM pigs.
Galli, Cesare; Perota, Andrea; Brunetti, Dario; Lagutina, Irina; Lazzari, Giovanna; Lucchini, Franco
2010-01-01
Techniques for genetic engineering of swine are providing genetically modified animals of importance for the field of xenotransplantation, animal models for human diseases and for a variety of research applications. Many of these modifications have been directed toward avoiding naturally existing cellular and antibody responses to species-specific antigens. A number of techniques are today available to engineering the genome of mammals, these range from the well established less efficient method of DNA microinjection into the zygote, the use of viral vectors, to the more recent use of somatic cell nuclear transfer. The use of enzymatic engineering that are being developed now will refine the precision of the genetic modification combined with the use of new vectors like transposons. The use of somatic cell nuclear transfer is currently the most efficient way to generate genetically modified pigs. The development of enzymatic engineering with zinc-finger nucleases, recombinases and transposons will revolutionize the field. Nevertheless, genetic engineering in large domesticated animals will remain a challenging task. Recent improvements in several fields of cell and molecular biology offer new promises and opportunities toward an easier, cost-effective and efficient generation of transgenic pigs. © 2010 John Wiley & Sons A/S.
NASA Technical Reports Server (NTRS)
Soderman, Paul T.; Olson, Larry (Technical Monitor)
1995-01-01
The NFAC 40- by 80- Foot Wind Tunnel at Ames is being refurbished with a new, deep acoustic lining in the test section which will make the facility nearly anechoic over a large frequency range. The modification history, key elements, and schedule will be discussed. Design features and expected performance gains will be described. Background noise reductions will be summarized. Improvements in aeroacoustic research techniques have been developed and used recently at NFAC on several wind tunnel tests of High Speed Research models. Research on quiet inflow microphones and struts will be described. The Acoustic Survey Apparatus in the 40x80 will be illustrated. A special intensity probe was tested for source localization. Multi-channel, high speed digital data acquisition is now used for acoustics. And most important, phased microphone arrays have been developed and tested which have proven to be very powerful for source identification and increased signal-to-noise ratio. Use of these tools for the HEAT model will be illustrated. In addition, an acoustically absorbent symmetry plane was built to satisfy the HEAT semispan aerodynamic and acoustic requirements. Acoustic performance of that symmetry plane will be shown.
Nakamura, Yoshiaki
2017-01-01
Primordial germ cells (PGCs) generate new individuals through differentiation, maturation and fertilization. This means that the manipulation of PGCs is directly linked to the manipulation of individuals, making PGCs attractive target cells in the animal biotechnology field. A unique biological property of avian PGCs is that they circulate temporarily in the vasculature during early development, and this allows us to access and manipulate avian germ lines. Following the development of a technique for transplantation, PGCs have become central to avian biotechnology, in contrast to the use of embryo manipulation and subsequent transfer to foster mothers, as in mammalian biotechnology. Today, avian PGC transplantation combined with recent advanced manipulation techniques, including cell purification, cryopreservation, depletion, and long-term culture in vitro, have enabled the establishment of genetically modified poultry lines and ex-situ conservation of poultry genetic resources. This chapter introduces the principles, history, and procedures of producing avian germline chimeras by transplantation of PGCs, and the current status of avian germline modification as well as germplasm cryopreservation. Other fundamental avian reproductive technologies are described, including artificial insemination and embryo culture, and perspectives of industrial applications in agriculture and pharmacy are considered, including poultry productivity improvement, egg modification, disease resistance impairment and poultry gene "pharming" as well as gene banking.
Marton, Ira; Honig, Arik; Omid, Ayelet; De Costa, Noam; Marhevka, Elena; Cohen, Barry; Zuker, Amir; Vainstein, Alexander
2013-01-01
Researchers and biotechnologists require methods to accurately modify the genome of higher eukaryotic cells. Such modifications include, but are not limited to, site-specific mutagenesis, site-specific insertion of foreign DNA, and replacement and deletion of native sequences. Accurate genome modifications in plant species have been rather limited, with only a handful of plant species and genes being modified through the use of early genome-editing techniques. The development of rare-cutting restriction enzymes as a tool for the induction of site-specific genomic double-strand breaks and their introduction as a reliable tool for genome modification in animals, animal cells and human cell lines have paved the way for the adaptation of rare-cutting restriction enzymes to genome editing in plant cells. Indeed, the number of plant species and genes which have been successfully edited using zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs) and engineered homing endonucleases is on the rise. In our review, we discuss the basics of rare-cutting restriction enzyme-mediated genome-editing technology with an emphasis on its application in plant species.
Chemical and Biological Tools for the Preparation of Modified Histone Proteins
Howard, Cecil J.; Yu, Ruixuan R.; Gardner, Miranda L.; Shimko, John C.; Ottesen, Jennifer J.
2016-01-01
Eukaryotic chromatin is a complex and dynamic system in which the DNA double helix is organized and protected by interactions with histone proteins. This system is regulated through, a large network of dynamic post-translational modifications (PTMs) exists to ensure proper gene transcription, DNA repair, and other processes involving DNA. Homogenous protein samples with precisely characterized modification sites are necessary to better understand the functions of modified histone proteins. Here, we discuss sets of chemical and biological tools that have been developed for the preparation of modified histones, with a focus on the appropriate choice of tool for a given target. We start with genetic approaches for the creation of modified histones, including the incorporation of genetic mimics of histone modifications, chemical installation of modification analogs, and the use of the expanded genetic code to incorporate modified amino acids. Additionally, we will cover the chemical ligation techniques that have been invaluable in the generation of complex modified histones that are indistinguishable from the natural counterparts. Finally, we will end with a prospectus on future directions of synthetic chromatin in living systems. PMID:25863817
A versatile breast reduction technique: Conical plicated central U shaped (COPCUs) mammaplasty
Copcu, Eray
2009-01-01
Background There have been numerous studies on reduction mammaplasty and its modifications in the literature. The multitude of modifications of reduction mammaplasty indicates that the ideal technique has yet to be found. There are four reasons for seeking the ideal technique. One reason is to preserve functional features of the breast: breastfeeding and arousal. Other reasons are to achieve the real geometric and aesthetic shape of the breast with the least scar and are to minimize complications of prior surgical techniques without causing an additional complication. Last reason is the limitation of the techniques described before. To these aims, we developed a new versatile reduction mammaplasty technique, which we called conical plicated central U shaped (COPCUs) mammaplasty. Methods We performed central plication to achieve a juvenile look in the superior pole of the breast and to prevent postoperative pseudoptosis and used central U shaped flap to achieve maximum NAC safety and to preserve lactation and nipple sensation. The central U flap was 6 cm in width and the superior conical plication was performed with 2/0 PDS. Preoperative and postoperative standard measures of the breast including the superior pole fullness were compared. Results Forty six patients were operated with the above mentioned technique. All of the patients were satisfied with functional and aesthetic results and none of them had major complications. There were no changes in the nipple innervation. Six patients becoming pregnant after surgery did not experience any problems with lactation. None of the patients required scar revision. Conclusion Our technique is a versatile, safe, reliable technique which creates the least scar, avoids previously described disadvantages, provides maximum preservation of functions, can be employed in all breasts regardless of their sizes. PMID:19575809
Energy and life-cycle cost analysis of a six-story office building
NASA Astrophysics Data System (ADS)
Turiel, I.
1981-10-01
An energy analysis computer program, DOE-2, was used to compute annual energy use for a typical office building as originally designed and with several energy conserving design modifications. The largest energy use reductions were obtained with the incorporation of daylighting techniques, the use of double pane windows, night temperature setback, and the reduction of artificial lighting levels. A life-cycle cost model was developed to assess the cost-effectiveness of the design modifications discussed. The model incorporates such features as inclusion of taxes, depreciation, and financing of conservation investments. The energy conserving strategies are ranked according to economic criteria such as net present benefit, discounted payback period, and benefit to cost ratio.
Artificial enzymes with protein scaffolds: structural design and modification.
Matsuo, Takashi; Hirota, Shun
2014-10-15
Recent development in biochemical experiment techniques and bioinformatics has enabled us to create a variety of artificial biocatalysts with protein scaffolds (namely 'artificial enzymes'). The construction methods of these catalysts include genetic mutation, chemical modification using synthetic molecules and/or a combination of these methods. Designed evolution strategy based on the structural information of host proteins has become more and more popular as an effective approach to construct artificial protein-based biocatalysts with desired reactivities. From the viewpoint of application of artificial enzymes for organic synthesis, recently constructed artificial enzymes mediating oxidation, reduction and C-C bond formation/cleavage are introduced in this review article. Copyright © 2014 Elsevier Ltd. All rights reserved.
The control of satellites with microgravity constraints: The COMET Control System
NASA Astrophysics Data System (ADS)
Grossman, Walter; Freesland, Douglas
1994-05-01
The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.
The control of satellites with microgravity constraints: The COMET Control System
NASA Technical Reports Server (NTRS)
Grossman, Walter; Freesland, Douglas
1994-01-01
The COMET attitude determination and control system, using inverse dynamics and a novel torque distribution/momentum management technique, has shown great flexibility, performance, and robustness. Three-axis control with two wheels is an inherent consequence of inverse dynamics control which allows for reduction in spacecraft weight and cost, or alternatively, provides a simple means of failure-redundancy for three-wheel spacecraft. The control system, without modification, has continued to perform well in spite of large changes in spacecraft mass properties and mission orbit altitude that have occurred during development. This flexibility has obviated imposition of early stringent ADACS design constraints and has greatly reduced commonly incurred ADACS modification costs and delay associated with program maturation.
Neupane, Dharmendra; Nepal, Bishal; Mikhaylov, Vasilii; Stine, Keith J.
2018-01-01
Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning pore and ligament sizes. The np-Au electrodes that are prepared using electrochemical techniques are robust and are easier to handle for their use in electrochemical biosensing. Here, we review different electrochemical strategies for the preparation, post-modification, and characterization of np-Au along with the synergistic use of both electrochemistry and np-Au for applications in biosensing. PMID:29547580
Bhattarai, Jay K; Neupane, Dharmendra; Nepal, Bishal; Mikhaylov, Vasilii; Demchenko, Alexei V; Stine, Keith J
2018-03-16
Nanoporous gold (np-Au), because of its high surface area-to-volume ratio, excellent conductivity, chemical inertness, physical stability, biocompatibility, easily tunable pores, and plasmonic properties, has attracted much interested in the field of nanotechnology. It has promising applications in the fields of catalysis, bio/chemical sensing, drug delivery, biomolecules separation and purification, fuel cell development, surface-chemistry-driven actuation, and supercapacitor design. Many chemical and electrochemical procedures are known for the preparation of np-Au. Recently, researchers are focusing on easier and controlled ways to tune the pores and ligaments size of np-Au for its use in different applications. Electrochemical methods have good control over fine-tuning pore and ligament sizes. The np-Au electrodes that are prepared using electrochemical techniques are robust and are easier to handle for their use in electrochemical biosensing. Here, we review different electrochemical strategies for the preparation, post-modification, and characterization of np-Au along with the synergistic use of both electrochemistry and np-Au for applications in biosensing.
Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Meyer, Anne S.
2015-01-01
Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has recently reached 100,000 tons with a gross market value just above US$ 1.1 billion. The techno-functional properties of the seaweed polysaccharides depend strictly on their unique structural make-up, notably degree and position of sulfation and presence of anhydro-bridges. Classical extraction techniques include hot alkali treatments, but recent research has shown promising results with enzymes. Current methods mainly involve use of commercially available enzyme mixtures developed for terrestrial plant material processing. Application of seaweed polysaccharide targeted enzymes allows for selective extraction at mild conditions as well as tailor-made modifications of the hydrocolloids to obtain specific functionalities. This review provides an update of the detailed structural features of κ-, ι-, λ-carrageenans, agars, and alginate, and a thorough discussion of enzyme assisted extraction and processing techniques for these hydrocolloids. PMID:26023840
Rhein-Knudsen, Nanna; Ale, Marcel Tutor; Meyer, Anne S
2015-05-27
Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has recently reached 100,000 tons with a gross market value just above US$ 1.1 billion. The techno-functional properties of the seaweed polysaccharides depend strictly on their unique structural make-up, notably degree and position of sulfation and presence of anhydro-bridges. Classical extraction techniques include hot alkali treatments, but recent research has shown promising results with enzymes. Current methods mainly involve use of commercially available enzyme mixtures developed for terrestrial plant material processing. Application of seaweed polysaccharide targeted enzymes allows for selective extraction at mild conditions as well as tailor-made modifications of the hydrocolloids to obtain specific functionalities. This review provides an update of the detailed structural features of κ-, ι-, λ-carrageenans, agars, and alginate, and a thorough discussion of enzyme assisted extraction and processing techniques for these hydrocolloids.
Titration in the treatment of the more troubled patient.
Winer, J A; Ornstein, E D
2001-01-01
This article defines and discusses a modification of technique recommended by the authors in the psychoanalytic treatment of more troubled patients--a modification they call titration. Titration is defined as a conscious decision by the analyst to increase or decrease assistance (or gratification) gradually, in order to facilitate the analytic process. The authors emphasize the complexity of decisions in treatment by focusing on the decision-making processes that titration requires. Guidelines and a case vignette are presented. The authors conclude by considering some of the politics involved in the introduction of technique modifications, the salience of the titration concept, and directions for further exploration.
Comparative study of novel endovascular treatment techniques for intracranial aneurysms
NASA Astrophysics Data System (ADS)
Cantón, Gádor; Lasheras, Juan C.; Levy, David I.; Sparks, Steven R.
2002-11-01
Intracranial aneurysms are life-threatening vascular lesions, which are potentially treatable to avoid the consequences of their rupture. Current treatments, either surgical or endovascular, are all guided to reduce the hemodynamic forces acting on the aneurysm wall in an effort to minimize the risk of rupture. Surgical clipping is still the most used technique to treat this type of aneurysm but there is a continued demand for less invasive approaches. This has led to the development of several endovascular techniques. We report here a comparative study of the reduction in the hemodynamic stresses and the modification of the flow in the parent vessel resulting from the use of three different techniques. The first one consists of endosaccular packing with platinum coils (GDC, Target Therapeutics), which is already widely used but its long-term efficacy has not yet been determined. The second one consists of the embolization of the aneurismal sac with Onyx, a polymer which hardens when in contact with the blood (being developed by Micro Therapeutics, Inc.). The third one involves the packing of the sac with hydrocoils, platinum wires coated with a gel which quickly hydrates when in contact with blood (developed by MicroVention). A Digital Particle Image Velocimetry (DPIV) system is used to measure in vitro the velocity field inside a model of an ACOM aneurysm (an aneurysm forming in the anterior communicating artery). Physiological accurate pulsatile flow conditions are input to the arterial model through a programmable pump. The measurements show that although all treatment techniques lead to a reduction in both normal and tangential shear stresses on the aneurismal sac, each one of them also leads to different modifications of the flow in the parent vessel which may have consequences related to potential for clotting. Comparison of the untreated aneurysm with the above three treated cases also showed that the characteristics of the wall shear stresses on the parent vessel are modified by the packing method.
Adaptive space warping to enhance passive haptics in an arthroscopy surgical simulator.
Spillmann, Jonas; Tuchschmid, Stefan; Harders, Matthias
2013-04-01
Passive haptics, also known as tactile augmentation, denotes the use of a physical counterpart to a virtual environment to provide tactile feedback. Employing passive haptics can result in more realistic touch sensations than those from active force feedback, especially for rigid contacts. However, changes in the virtual environment would necessitate modifications of the physical counterparts. In recent work space warping has been proposed as one solution to overcome this limitation. In this technique virtual space is distorted such that a variety of virtual models can be mapped onto one single physical object. In this paper, we propose as an extension adaptive space warping; we show how this technique can be employed in a mixed-reality surgical training simulator in order to map different virtual patients onto one physical anatomical model. We developed methods to warp different organ geometries onto one physical mock-up, to handle different mechanical behaviors of the virtual patients, and to allow interactive modifications of the virtual structures, while the physical counterparts remain unchanged. Various practical examples underline the wide applicability of our approach. To the best of our knowledge this is the first practical usage of such a technique in the specific context of interactive medical training.
Albumin modification and fragmentation in renal disease.
Donadio, Carlo; Tognotti, Danika; Donadio, Elena
2012-02-18
Albumin is the most important antioxidant substance in plasma and performs many physiological functions. Furthermore, albumin is the major carrier of endogenous molecules and exogenous ligands. This paper reviews the importance of post-translational modifications of albumin and fragments thereof in patients with renal disease. First, current views and controversies on renal handling of proteins, mainly albumin, will be discussed. Post-translational modifications, namely the fragmentation of albumin found with proteomic techniques in nephrotic patients, diabetics, and ESRD patients will be presented and discussed. It is reasonable to hypothesize that proteolytic fragmentation of serum albumin is due to a higher susceptibility to proteases, induced by oxidative stress. The clinical relevance of the fragmentation of albumin has not yet been established. These modifications could affect some physiological functions of albumin and have a patho-physiological role in uremic syndrome. Proteomic analysis of serum allows the identification of over-expressed proteins and can detect post-translational modifications of serum proteins, hitherto hidden, using standard laboratory techniques. Copyright © 2011 Elsevier B.V. All rights reserved.
Ostrander, Roger V; McKinney, Bart I
2012-10-01
Studies suggest that arthroscopic repair techniques may have high recurrence rates for larger rotator cuff tears. A more anatomic repair may improve the success rate when performing arthroscopic rotator cuff repair. We hypothesized that a triple-row modification of the suture-bridge technique for rotator cuff repair would result in significantly more footprint contact area and pressure between the rotator cuff and the humeral tuberosity. Eighteen ovine infraspinatus tendons were repaired using 1 of 3 simulated arthroscopic techniques: a double-row repair, the suture-bridge technique, and a triple-row repair. The triple-row repair technique is a modification of the suture-bridge technique that uses an additional reducing anchor between the medial and lateral rows. Six samples were tested per group. Pressure-indicating film was used to measure the footprint contact area and pressure after each repair. The triple-row repair resulted in significantly more rotator cuff footprint contact area and contact pressure compared with the double-row technique and the standard suture-bridge technique. No statistical difference in contact area or contact pressure was found between the double-row technique and the suture-bridge technique. The triple-row technique for rotator cuff repair results in significantly more footprint contact area and contact pressure compared with the double-row and standard suture-bridge techniques. This more anatomic repair may improve the healing rate when performing arthroscopic rotator cuff repair. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.
Visual Search with Image Modification in Age-Related Macular Degeneration
Wiecek, Emily; Jackson, Mary Lou; Dakin, Steven C.; Bex, Peter
2012-01-01
Purpose. AMD results in loss of central vision and a dependence on low-resolution peripheral vision. While many image enhancement techniques have been proposed, there is a lack of quantitative comparison of the effectiveness of enhancement. We developed a natural visual search task that uses patients' eye movements as a quantitative and functional measure of the efficacy of image modification. Methods. Eye movements of 17 patients (mean age = 77 years) with AMD were recorded while they searched for target objects in natural images. Eight different image modification methods were implemented and included manipulations of local image or edge contrast, color, and crowding. In a subsequent task, patients ranked their preference of the image modifications. Results. Within individual participants, there was no significant difference in search duration or accuracy across eight different image manipulations. When data were collapsed across all image modifications, a multivariate model identified six significant predictors for normalized search duration including scotoma size and acuity, as well as interactions among scotoma size, age, acuity, and contrast (P < 0.05). Additionally, an analysis of image statistics showed no correlation with search performance across all image modifications. Rank ordering of enhancement methods based on participants' preference revealed a trend that participants preferred the least modified images (P < 0.05). Conclusions. There was no quantitative effect of image modification on search performance. A better understanding of low- and high-level components of visual search in natural scenes is necessary to improve future attempts at image enhancement for low vision patients. Different search tasks may require alternative image modifications to improve patient functioning and performance. PMID:22930725
Single cell and single molecule techniques for the analysis of the epigenome
NASA Astrophysics Data System (ADS)
Wallin, Christopher Benjamin
Epigenetic regulation is a critical biological process for the health and development of a cell. Epigenetic regulation is facilitated by covalent modifications to the underlying DNA and chromatin proteins. A fundamental understanding of these epigenetic modifications and their associated interactions at the molecular scale is necessary to explain phenomena including cellular identity, stem cell plasticity, and neoplastic transformation. It is widely known that abnormal epigenetic profiles have been linked to many diseases, most notably cancer. While the field of epigenetics has progressed rapidly with conventional techniques, significant advances remain to be made with respect to combinatoric analysis of epigenetic marks and single cell epigenetics. Therefore, in this dissertation, I will discuss our development of devices and methodologies to address these pertinent issues. First, we designed a preparatory polydimethylsiloxane (PDMS) microdevice for the extraction, purification, and stretching of human chromosomal DNA and chromatin from small cell populations down to a single cell. The valveless device captures cells by size exclusion within the micropillars, entraps the DNA or chromatin in the micropillars after cell lysis, purifies away the cellular debris, and fluorescently labels the DNA and/or chromatin all within a single reaction chamber. With the device, we achieve nearly 100% extraction efficiency of the DNA. The device is also used for in-channel immunostaining of chromatin followed by downstream single molecule chromatin analysis in nanochannels (SCAN). Second, using multi-color, time-correlated single molecule measurements in nanochannels, simultaneous coincidence detection of 2 epigenetic marks is demonstrated. Coincidence detection of 3 epigenetic marks is also established using a pulsed interleaved excitation scheme. With these two promising results, genome-wide quantification of epigenetic marks was pursued. Unfortunately, quantitative SCAN never materialized. Reasons for this, including poor signal to background, are explained in detail. Third, development of mobility-SCAN, an analytical technique for measuring and analyzing single molecules based on their fluorescent signature and their electrophoretic mobility in nanochannels is described. We use the technique to differentiate biomolecules from complex mixtures and derive parameters such as diffusion coefficients and effective charges. Finally, the device is used to detect binding interactions of various complexes similar to affinity capillary electrophoresis, but on a single molecule level. Fourth, we conclude by briefly discussing SCAN-sort, a technique to sort individual chromatin molecules based on their fluorescent emissions for further downstream analysis such as DNA sequencing. We demonstrate a 2-fold enrichment of chromatin from sorting and discuss possible system modifications for better performance in the future.
Development of Fundamental Technologies for Micro Bioreactors
NASA Astrophysics Data System (ADS)
Sato, Kiichi; Kitamori, Takehiko
This chapter reviews the development of fundamental technologies required for microchip-based bioreactors utilizing living mammalian cells and pressure driven flow. The most important factor in the bioreactor is the cell culture. For proper cell culturing, continuous medium supply from a microfluidic channel and appropriate modification of the channel surface to accommodate cell attachment is required. Moreover, the medium flow rate should be chosen carefully, because shear stress affects cell activity. The techniques presented here could be applied to the development of micro bioreactors such as microlivers, pigment production by plant cells, and artificial insemination.
Biological water quality monitoring using chemiluminescent and bioluminescent techniques
NASA Technical Reports Server (NTRS)
Thomas, R. R.
1978-01-01
Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.
Methods of Single Station and Limited Data Analysis and Forecasting
1985-08-15
example using real data. Discusses modifications of SSA technique in certain climatological regimes and describes some statistical tech- niques for SSA of... caster has access to radar or satellite observations, or any computer products during the period of his isolation. Where calculations are involved, it is...chapters of the text will deal with special topics such as modifications of the SSA technique that must be considered for certain clima- tological regimes
Techniques for the Detection of Faulty Packet Header Modifications
2014-03-12
layer approaches to check if packets are being altered by middleboxes and were primarily developed as network neutrality analysis tools. Switzerland works...local and metropolitan area networks –specific requirements part 11: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications...policy or position of the Department of Defense or the U.S. Government. Understanding, measuring, and debugging IP networks , particularly across
Investigation of Accelerated Life Prediction Techniques
1975-10-01
26, No. 1, 1974, ;). 13. 116. Krukar, M., et al, STUDDED TIRE PAVEMENT WEAR REDUCTION AND REPAIR, Washington State Dept. of Highways, Highway...167. Okushlma, K., and Kakino, Y., STUD * ON INFLUENCE OF GROOVE WEAR OF A TOOL TO SURFACE ROUGHNESS DURING FINISHING TURNING OF CARBON STEEL, Journal...MODIFICATION OF ASPHALT CEMENTS FOR IMPROVE- MENT OF WEAR RESISTANCE OF PAVEMENT SURFACES, Materials Research «nd Development, Inc., Oakland
Techniques and Measurements. Seychelles Integrated Science. [Teacher and Pupil Booklets]. Unit 1.
ERIC Educational Resources Information Center
Brophy, M.; Fryars, M.
Seychelles Integrated Science (SIS), a 3-year laboratory-based science program for students (ages 11-15) in upper primary grades 7, 8, and 9, was developed from an extensive evaluation and modification of previous P7-P9 materials. This P7 SIS unit is designed to: (1) introduce students to and familiarize them with working in the school laboratory;…
Evaluation of Methodology for Estimating the Cost of Air Force On-The-Job Training. Final Report.
ERIC Educational Resources Information Center
Samers, Bernard N.; And Others
Described is the final phase of a study directed at the development of an on-the-job training (OJT) costing methodology. Utilizing a modification of survey techniques tested and evaluated during the previous phase, estimates were obtained for the cost of OJT for airman training from the l-level (unskilled to the 3-level (semiskilled) in five…
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.
Chemoenzymatic Labeling of Proteins: Techniques and Approaches
Rashidian, Mohammad; Dozier, Jonathan K.; Distefano, Mark D.
2013-01-01
Site-specific modification of proteins is a major challenge in modern chemical biology due to the large number of reactive functional groups typically present in polypeptides. Because of its importance in biology and medicine, the development of methods for site-specific modification of proteins is an area of intense research. Selective protein modification procedures have been useful for oriented protein immobilization, for studies of naturally-occurring post-translational modifications, for creating antibody-drug conjugates, for the introduction of fluorophores and other small molecules on to proteins, for examining protein structure, folding, dynamics and protein-protein interactions and for the preparation of protein-polymer conjugates. One of the most important approaches for protein labeling is to incorporate bioorthogonal functionalities into proteins at specific sites via enzymatic reactions. The incorporated tags then enable reactions that are chemoselective, whose functional groups are not only inert in biological media, but also do not occur natively in proteins or other macromolecules. This review article summarizes the enzymatic strategies, which enable site-specific functionalization of proteins with a variety of different functional groups. The enzymes covered in this review include formylglycine generating enzyme, sialyltransferases, phosphopantetheinyltransferases, O-GlcNAc post-translational modification, sortagging, transglutaminase, farnesyltransferase, biotin ligase, lipoic acid ligase and N-myristoyl transferase. PMID:23837885
NASA Technical Reports Server (NTRS)
Harwood, P. (Principal Investigator); Finley, R.; Mcculloch, S.; Marphy, D.; Hupp, B.
1976-01-01
The author has identified the following significant results. Image interpretation mapping techniques were successfully applied to test site 5, an area with a semi-arid climate. The land cover/land use classification required further modification. A new program, HGROUP, added to the ADP classification schedule provides a convenient method for examining the spectral similarity between classes. This capability greatly simplifies the task of combining 25-30 unsupervised subclasses into about 15 major classes that approximately correspond to the land use/land cover classification scheme.
History Matters: Incremental Ontology Reasoning Using Modules
NASA Astrophysics Data System (ADS)
Cuenca Grau, Bernardo; Halaschek-Wiener, Christian; Kazakov, Yevgeny
The development of ontologies involves continuous but relatively small modifications. Existing ontology reasoners, however, do not take advantage of the similarities between different versions of an ontology. In this paper, we propose a technique for incremental reasoning—that is, reasoning that reuses information obtained from previous versions of an ontology—based on the notion of a module. Our technique does not depend on a particular reasoning calculus and thus can be used in combination with any reasoner. We have applied our results to incremental classification of OWL DL ontologies and found significant improvement over regular classification time on a set of real-world ontologies.
Wilsonian methods of concept analysis: a critique.
Hupcey, J E; Morse, J M; Lenz, E R; Tasón, M C
1996-01-01
Wilsonian methods of concept analysis--that is, the method proposed by Wilson and Wilson-derived methods in nursing (as described by Walker and Avant; Chinn and Kramer [Jacobs]; Schwartz-Barcott and Kim; and Rodgers)--are discussed and compared in this article. The evolution and modifications of Wilson's method in nursing are described and research that has used these methods, assessed. The transformation of Wilson's method is traced as each author has adopted his techniques and attempted to modify the method to correct for limitations. We suggest that these adaptations and modifications ultimately erode Wilson's method. Further, the Wilson-derived methods have been overly simplified and used by nurse researchers in a prescriptive manner, and the results often do not serve the purpose of expanding nursing knowledge. We conclude that, considering the significance of concept development for the nursing profession, the development of new methods and a means for evaluating conceptual inquiry must be given priority.
Development of Advanced Coatings for Laser Modifications Through Process and Materials Simulation
NASA Astrophysics Data System (ADS)
Martukanitz, R. P.; Babu, S. S.
2004-06-01
A simulation-based system is currently being constructed to aid in the development of advanced coating systems for laser cladding and surface alloying. The system employs loosely coupled material and process models that allow rapid determination of material compatibility over a wide range of processing conditions. The primary emphasis is on the development and identification of composite coatings for improved wear and corrosion resistance. The material model utilizes computational thermodynamics and kinetic analysis to establish phase stability and extent of diffusional reactions that may result from the thermal response of the material during virtual processing. The process model is used to develop accurate thermal histories associated with the laser surface modification process and provides critical input for the non-isothermal materials simulations. These techniques were utilized to design a laser surface modification experiment that utilized the addition of stainless steel alloy 431 and TiC produced using argon and argon and nitrogen shielding. The deposits representing alloy 431 and TiC powder produced in argon resulted in microstructures retaining some TiC particles and an increase in hardness when compared to deposits produced using only the 431 powder. Laser deposits representing alloy 431 and TiC powder produced with a mixture of argon and nitrogen shielding gas resulted in microstructures retaining some TiC particles, as well as fine precipitates of Ti(CN) formed during cooling and a further increase in hardness of the deposit.
NASA Technical Reports Server (NTRS)
Hinds, William E.; Mayer, David J.; Evans, Juli; Spratt, Shahn; Lane, Philip K.; Rodriguez, Shari L.; Navidi, Meena; Armstrong, Rachel; Lemos, Bonnie; Dalton, Bonnie P. (Technical Monitor)
1996-01-01
Recent and upcoming spaceflights are investigating the effect of weightlessness on developing neural and organ systems. Pregnant rats and dams with neonates have to be accommodated in cages that support the special requirements of these animals. Extensive ground testing of cage concepts, the effect of launch and landing stresses on the maintenance of pregnancy and maternal behavior at different neonatal ages, and techniques for monitoring adaptability to change are discussed. A spaceflight opportunity for the NlH.R3 payload of rat families at three different postnatal ages demonstrated that the survival of very young animals was not good but that older newborns could be returned to Earth in reasonably good health. The development of cages for the Research Animal Holding Facility (RAHF) to support the flight of neonates on Neurolab was continued and incorporated modifications that were demonstrated by the NIH.R3 flight. Other modifications to the RAHF are discussed. Data from biocompatibility and experiment verification testing are presented.
Progress and biotechnological prospects in fish transgenesis.
Tonelli, Fernanda M P; Lacerda, Samyra M S N; Tonelli, Flávia C P; Costa, Guilherme M J; de França, Luiz Renato; Resende, Rodrigo R
2017-11-01
The history of transgenesis is marked by milestones such as the development of cellular transdifferentiation, recombinant DNA, genetic modification of target cells, and finally, the generation of simpler genetically modified organisms (e.g. bacteria and mice). The first transgenic fish was developed in 1984, and since then, continuing technological advancements to improve gene transfer have led to more rapid, accurate, and efficient generation of transgenic animals. Among the established methods are microinjection, electroporation, lipofection, viral vectors, and gene targeting. Here, we review the history of animal transgenesis, with an emphasis on fish, in conjunction with major developments in genetic engineering over the past few decades. Importantly, spermatogonial stem cell modification and transplantation are two common techniques capable of revolutionizing the generation of transgenic fish. Furthermore, we discuss recent progress and future biotechnological prospects of fish transgenesis, which has strong applications for the aquaculture industry. Indeed, some transgenic fish are already available in the current market, validating continued efforts to improve economically important species with biotechnological advancements. Copyright © 2017. Published by Elsevier Inc.
Germline Genetic Modification and Identity: the Mitochondrial and Nuclear Genomes.
Scott, Rosamund; Wilkinson, Stephen
2017-12-01
In a legal 'first', the UK removed a prohibition against modifying embryos in human reproduction, to enable mitochondrial replacement techniques (MRTs), a move the Government distanced from 'germline genetic modification', which it aligned with modifying the nuclear genome. This paper (1) analyzes the uses and meanings of this term in UK/US legal and policy debates; and (2) evaluates related ethical concerns about identity. It shows that, with respect to identity, MRTs and nuclear genome editing techniques such as CRISPR/Cas-9 (now a policy topic), are not as different as has been supposed. While it does not follow that the two should be treated exactly alike, one of the central reasons offered for treating MRTs more permissively than nuclear genetic modification, and for not regarding MRTs as 'germline genetic modification', is thereby in doubt. Identity cannot, by itself, do the work thus far assigned to it, explicitly or otherwise, in law and policy.
Recombinant organisms for production of industrial products
Adrio, Jose-Luis
2010-01-01
A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding techniques and their modifications are contributing greatly to the development of improved industrial processes. In addition, functional genomics, proteomics and metabolomics are being exploited for the discovery of novel valuable small molecules for medicine as well as enzymes for catalysis. The sequencing of industrial microbal genomes is being carried out which bodes well for future process improvement and discovery of new industrial products. PMID:21326937
Turturro, A; Hart, R W
1987-01-01
A better understanding of chemical-induced cancer has led to appreciation of similarities to problems addressed by risk management of radiation-induced toxicity. Techniques developed for cancer risk assessment of toxic substances can be generalized to toxic agents. A recent problem-solving approach for risk management of toxic substances developed for the U.S. Department of Health and Human Services, and the role of risk assessment and how uncertainty should be treated within the context of this approach, is discussed. Finally, two different methods, research into the assumptions underlying risk assessment and the modification of risk assessment/risk management documents, are used to illustrate how the technique can be applied.
Development of Techniques to Investigate Sonoluminescence as a Source of Energy Harvesting
NASA Technical Reports Server (NTRS)
Wrbanek, John D.; Fralick, Gustave C.; Wrbanek, Susan Y.
2007-01-01
Instrumentation techniques are being developed at NASA Glenn Research Center to measure optical, radiation, and thermal properties of the phenomena of sonoluminescence, the light generated using acoustic cavitation. Initial efforts have been directed to the generation of the effect and the imaging of the glow in water and solvents. Several images have been produced of the effect showing the location within containers, without the additions of light enhancers to the liquid. Evidence of high energy generation in the modification of thin films from sonoluminescence in heavy water was seen that was not seen in light water. Bright, localized sonoluminescence was generated using glycerin for possible applications to energy harvesting. Issues to be resolved for an energy harvesting concept will be addressed.
Stereo vision techniques for telescience
NASA Astrophysics Data System (ADS)
Hewett, S.
1990-02-01
The Botanic Experiment is one of the pilot experiments in the Telescience Test Bed program at the ESTEC research and technology center of the European Space Agency. The aim of the Telescience Test Bed is to develop the techniques required by an experimenter using a ground based work station for remote control, monitoring, and modification of an experiment operating on a space platform. The purpose of the Botanic Experiment is to examine the growth of seedlings under various illumination conditions with a video camera from a number of viewpoints throughout the duration of the experiment. This paper describes the Botanic Experiment and the points addressed in developing a stereo vision software package to extract quantitative information about the seedlings from the recorded video images.
Applications of optical sensing for laser cutting and drilling.
Fox, Mahlen D T; French, Paul; Peters, Chris; Hand, Duncan P; Jones, Julian D C
2002-08-20
Any reliable automated production system must include process control and monitoring techniques. Two laser processing techniques potentially lending themselves to automation are percussion drilling and cutting. For drilling we investigate the performance of a modification of a nonintrusive optical focus control system we previously developed for laser welding, which exploits the chromatic aberrations of the processing optics to determine focal error. We further developed this focus control system for closed-loop control of laser cutting. We show that an extension of the technique can detect deterioration in cut quality, and we describe practical trials carried out on different materials using both oxygen and nitrogen assist gas. We base our techniques on monitoring the light generated by the process, captured nonintrusively by the effector optics and processed remotely from the workpiece. We describe the relationship between the temporal and the chromatic modulation of the detected light and process quality and show how the information can be used as the basis of a process control system.
Malinowski, Andrzej; Mołas, Justyna; Maciołek-Blewniewska, Grazyna; Cieślak, Jarosław
2006-02-01
Vault haematoma is one of the most common complication of vaginal hysterectomy. The aim of this work was to analyse the effects of a modification of incision and closure technique of the vaginal vault on the incidence of vault haematoma after vaginal hysterectomy. The study group consisted of 333 women of whom 49 (group A) underwent vaginal hysterectomy traditional technique of incision and closure of the vaginal vault, an 284 (group B) modified technique. Following parameters were evaluated: number of vault haematomas, blood loss, postoperative fever, required antibiotics, length of hospital stay. The risk of vault haematoma was significantly lower in the group B (1,06% vs 12,4%). Loss of blood was higher in group A (310 ml vs 206 ml). Incidence of postoperative fever was in 12,2% patients from group A, and 1,4% from group B. The length of hospitalization was lower for women in group B (4,3 days compared with 7,3 days). The modification of incision and closure technique of the vaginal vault during vaginal hysterectomy is recommended to minimise intra- and postoperative complications.
Salleh, Fatmah M; Al-Mekhlafi, Abdulsalam M; Nordin, Anisah; Yasin, 'Azlin M; Al-Mekhlafi, Hesham M; Moktar, Norhayati
2011-01-01
This study was conducted to evaluate the modification of the usual Gram-chromotrope staining technique developed in-house known as Gram-chromotrope Kinyoun (GCK) in comparison with the Weber Modified Trichrome (WMT) staining technique; as the reference technique. Two hundred and ninety fecal specimens received by the Microbiology Diagnostic Laboratory of Hospital Universiti Kebangsaan Malaysia were examined for the presence of microsporidial spores. The sensitivity and specificity of GCK compared to the reference technique were 98% and 98.3%, respectively. The positive and negative predictive values were 92.5% and 99.6%, respectively. The agreement between the reference technique and the GCK staining technique was statistically significant by Kappa statistics (K = 0.941, P < 0.001). It is concluded that the GCK staining technique has high sensitivity and specificity in the detection of microsporidial spores in fecal specimens. Hence, it is recommended to be used in the diagnosis of intestinal microsporidiosis. Copyright © 2011 Elsevier Inc. All rights reserved.
XPS Protocol for the Characterization of Pristine and Functionalized Single Wall Carbon Nanotubes
NASA Technical Reports Server (NTRS)
Sosa, E. D.; Allada, R.; Huffman, C. B.; Arepalli, S.
2009-01-01
Recent interest in developing new applications for carbon nanotubes (CNT) has fueled the need to use accurate macroscopic and nanoscopic techniques to characterize and understand their chemistry. X-ray photoelectron spectroscopy (XPS) has proved to be a useful analytical tool for nanoscale surface characterization of materials including carbon nanotubes. Recent nanotechnology research at NASA Johnson Space Center (NASA-JSC) helped to establish a characterization protocol for quality assessment for single wall carbon nanotubes (SWCNTs). Here, a review of some of the major factors of the XPS technique that can influence the quality of analytical data, suggestions for methods to maximize the quality of data obtained by XPS, and the development of a protocol for XPS characterization as a complementary technique for analyzing the purity and surface characteristics of SWCNTs is presented. The XPS protocol is then applied to a number of experiments including impurity analysis and the study of chemical modifications for SWCNTs.
NASA Technical Reports Server (NTRS)
Greenberg, J. S.; Miller, B. P.
1979-01-01
The feasibility of applying strategic business planning techniques which are developed and used in the private sector to the planning of certain projects within the NASA Office of Space and Terrestrial Applications was assessed. The methods of strategic business planning that are currently in use in the private sector are examined. The typical contents of a private sector strategic business plan and the techniques commonly used to develop the contents of the plan are described, along with modifications needed to apply these concepts to public sector projects. The current long-range planning process in the Office of Space and Terrestrial Applications is reviewed and program initiatives that might be candidates for the use of strategic business planning techniques are identified. In order to more fully illustrate the information requirements of a strategic business plan for a NASA program, a sample business plan is prepared for a hypothetical Operational Earth Resources Satellite program.
Transonic Free-To-Roll Analysis of the F/A-18E and F-35 Configurations
NASA Technical Reports Server (NTRS)
Owens, D. Bruce; McConnell, Jeffrey K.; Brandon, Jay M.; Hall, Robert M.
2004-01-01
The free-to-roll technique is used as a tool for predicting areas of uncommanded lateral motions. Recently, the NASA/Navy/Air Force Abrupt Wing Stall Program extended the use of this technique to the transonic speed regime. Using this technique, this paper evaluates various wing configurations on the pre-production F/A-18E aircraft and the Joint Strike Fighter (F-35) aircraft. The configurations investigated include leading and trailing edge flap deflections, fences, leading edge flap gap seals, and vortex generators. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel. The analysis used a modification of a figure-of-merit developed during the Abrupt Wing Stall Program to discern configuration effects. The results showed how the figure-of-merit can be used to schedule wing flap deflections to avoid areas of uncommanded lateral motion. The analysis also used both static and dynamic wind tunnel data to provide insight into the uncommanded lateral behavior. The dynamic data was extracted from the time history data using parameter identification techniques. In general, modifications to the pre-production F/A-18E resulted in shifts in angle-of-attack where uncommanded lateral activity occurred. Sealing the gap between the inboard and outboard leading-edge flaps on the Navy version of the F-35 eliminated uncommanded lateral activity or delayed the activity to a higher angle-of-attack.
Targets to treat metabolic syndrome in polycystic ovary syndrome
Mahalingaiah, Shruthi; Diamanti-Kandarakis, Evanthia
2016-01-01
Introduction Metabolic syndrome is comprised of a combination of the following states: increased insulin resistance, dyslipidemia, cardiovascular disease, and increased abdominal obesity. Women with polycystic ovary syndrome (PCOS) have an increased risk of developing metabolic syndrome over the course of their lives. Metabolic syndrome increases risk of major cardiovascular events, morbidity, quality of life, and overall health care costs. Though metabolic syndrome in women with PCOS is an area of great concern, there is no effective individual medical therapeutic to adequately treat this issue. Areas Covered This article will review key aspects of metabolic syndrome in PCOS. We will discuss classic and novel therapeutics to address metabolic syndrome in women with PCOS. We will conclude with the importance of developing strategic interventions to increase the compliance to lifestyle and dietary modification, in addition to appreciation of the emerging pharmaceutical therapeutics available. Expert Opinion Innovation in lifestyle modification, including diet, exercise, with and without dedicated stress reduction techniques is the future in treatment of metabolic syndrome in PCOS. Application of novel interventions, such as group medical care, may improve future adherence to lifestyle modification recommendations, in addition to or in combination with pharmaceutical therapeutics. PMID:26488852
Synthesis and characterization of polymer layers for control of fluid transport
NASA Astrophysics Data System (ADS)
Vatansever, Fehime
The level of wetting of fiber surface with liquids is an important characteristic of fibrous materials. It is related to fiber surface energy and the structure of the material. Surface energy can be changed by surface modification via the grafting methodologies that have been reported for introducing new and stable functionality to fibrous substrates without changing bulk properties. Present work is dedicated to synthesis and characterization of macromolecular layers grafted to fiber surface in order to achieve directional liquid transport for the modified fabric. Modification technique used here is based on formation of stable polymer layer on fabric surface using "grafting to" technique. Specifically, modification of fabric with wettability gradient for facilitated one way-liquid transport, and pointed modification of yarn-based channels on textile microfluidic device for directional liquid transport are reported here. First, fabric was activated with alkali (NaOH) solution. Second, poly (glycidyl methacrylate) (PGMA) was deposited on fabric as an anchoring layer. Finally, polymers of interest were grafted to surface through the epoxy functionality of PGMA. Effect of polymer grafting on the wicking property of the fabric has been evaluated by vertical wicking technique at the each step of surface modification. The results shows that wicking performance of fabric can be altered by grafting of a thin nanoscale polymeric film. For the facilitated liquid transport, the gradient polymer coating was created using "grafting to" technique and its dependence on the grafting temperature. Wettability gradient from hydrophilic to hydrophobic (change in water contact angle from 0 to 140 degrees on fabric) was achieved by grafting of polystyrene (PS) and polyacrylic acid (PAA) sequentially with concentration gradient. This study proposes that fabric with wettability gradient property can be used to transfer sweat from skin and support moisture management when it is used in a laminated garment structure. For cooling performance evaluation, modified fabrics were tested with surface differential scanning calorimeter, and improved cooling effect was found with the fabric that has wettability gradient. Directional liquid transport can be achieved on amphiphilic fabric. To this end, fabric consisting of PET and PP yarn is fabricated. Activation and PGMA deposition yields an array of highly reactive PET channels that are constrained by hydrophobic PP boundaries. Aqueous solutions are transported in the channels by capillary forces where the direction of the liquid transport is defined by pH-response of the grafted polymers. The system of pH-selective channels in the developed textile based microfluidic chip could find analytical applications and can be used for smart cloth.
Recent Developments on Genetic Engineering of Microalgae for Biofuels and Bio-Based Chemicals.
Ng, I-Son; Tan, Shih-I; Kao, Pei-Hsun; Chang, Yu-Kaung; Chang, Jo-Shu
2017-10-01
Microalgae serve as a promising source for the production of biofuels and bio-based chemicals. They are superior to terrestrial plants as feedstock in many aspects and their biomass is naturally rich in lipids, carbohydrates, proteins, pigments, and other valuable compounds. Due to the relatively slow growth rate and high cultivation cost of microalgae, to screen efficient and robust microalgal strains as well as genetic modifications of the available strains for further improvement are of urgent demand in the development of microalgae-based biorefinery. In genetic engineering of microalgae, transformation and selection methods are the key steps to accomplish the target gene modification. However, determination of the preferable type and dosage of antibiotics used for transformant selection is usually time-consuming and microalgal-strain-dependent. Therefore, more powerful and efficient techniques should be developed to meet this need. In this review, the conventional and emerging genome-editing tools (e.g., CRISPR-Cas9, TALEN, and ZFN) used in editing the genomes of nuclear, mitochondria, and chloroplast of microalgae are thoroughly surveyed. Although all the techniques mentioned above demonstrate their abilities to perform gene editing and desired phenotype screening, there still need to overcome higher production cost and lower biomass productivity, to achieve efficient production of the desired products in microalgal biorefineries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Ramrakhiani, Lata; Ghosh, Sourja; Majumdar, Swachchha
2016-09-01
Heavy metal pollution in water emerges as a severe socio-environmental problem originating primarily from the discharge of industrial wastewater. In view of the toxic, non-biodegradable, and persistent nature of most of the heavy metal ions, remediation of such components becomes an absolute necessity. Biosorption is an emerging tool for bioremediation that has gained momentum for employing low-cost biological materials with effective metal binding capacities. Even though biological materials possess excellent metal adsorption abilities, they show poor mechanical strength and low rigidity. Other disadvantages include solid-liquid separation problems, possible biomass swelling, lower efficiency for regeneration or reuse, and frequent development of high pressure drop in the column mode that limits its applications under real conditions. To improve the biosorption efficiency, biomasses need to be modified with a simple technique for selective/multi-metal adsorption. This review is intended to cover discussion on biomass modification for enhanced biosorption efficiency, mechanism studies using various instrumental/analytical techniques, and future direction for research and development including the fate of spent biosorbent. In most of the previously published researches, difficulty of the process in scaling up has not been addressed. The current article outlines the application potential of biosorbents in the development of hybrid technology integrated with membrane processes for water and wastewater treatment in industrial scale.
Cancer gene therapy with targeted adenoviruses.
Bachtarzi, Houria; Stevenson, Mark; Fisher, Kerry
2008-11-01
Clinical experience with adenovirus vectors has highlighted the need for improved delivery and targeting. This manuscript aims to provide an overview of the techniques currently under development for improving adenovirus delivery to malignant cells in vivo. Primary research articles reporting improvements in adenoviral gene delivery are described. Strategies include genetic modification of viral coat proteins, non-genetic modifications including polymer encapsulation approaches and pharmacological interventions. Reprogramming adenovirus tropism in vitro has been convincingly demonstrated using a range of genetic and physical strategies. These studies have provided new insights into our understanding of virology and the field is progressing. However, there are still some limitations that need special consideration before adenovirus-targeted cancer gene therapy emerges as a routine treatment in the clinical setting.
High-Throughput Method of Whole-Brain Sectioning, Using the Tape-Transfer Technique.
Pinskiy, Vadim; Jones, Jamie; Tolpygo, Alexander S; Franciotti, Neil; Weber, Kevin; Mitra, Partha P
2015-01-01
Cryostat sectioning is a popular but labor-intensive method for preparing histological brain sections. We have developed a modification of the commercially available CryoJane tape collection method that significantly improves the ease of collection and the final quality of the tissue sections. The key modification involves an array of UVLEDs to achieve uniform polymerization of the glass slide and robust adhesion between the section and slide. This report presents system components and detailed procedural steps, and provides examples of end results; that is, 20 μm mouse brain sections that have been successfully processed for routine Nissl, myelin staining, DAB histochemistry, and fluorescence. The method is also suitable for larger brains, such as rat and monkey.
High-Throughput Method of Whole-Brain Sectioning, Using the Tape-Transfer Technique
Pinskiy, Vadim; Jones, Jamie; Tolpygo, Alexander S.; Franciotti, Neil; Weber, Kevin; Mitra, Partha P.
2015-01-01
Cryostat sectioning is a popular but labor-intensive method for preparing histological brain sections. We have developed a modification of the commercially available CryoJane tape collection method that significantly improves the ease of collection and the final quality of the tissue sections. The key modification involves an array of UVLEDs to achieve uniform polymerization of the glass slide and robust adhesion between the section and slide. This report presents system components and detailed procedural steps, and provides examples of end results; that is, 20μm mouse brain sections that have been successfully processed for routine Nissl, myelin staining, DAB histochemistry, and fluorescence. The method is also suitable for larger brains, such as rat and monkey. PMID:26181725
A Review of Particle Swarm Optimization
NASA Astrophysics Data System (ADS)
Jain, N. K.; Nangia, Uma; Jain, Jyoti
2018-03-01
This paper presents an overview of the research progress in Particle Swarm Optimization (PSO) during 1995-2017. Fifty two papers have been reviewed. They have been categorized into nine categories based on various aspects. This technique has attracted many researchers because of its simplicity which led to many improvements and modifications of the basic PSO. Some researchers carried out the hybridization of PSO with other evolutionary techniques. This paper discusses the progress of PSO, its improvements, modifications and applications.
NASA Astrophysics Data System (ADS)
Krummacher, B. C.; Mathai, M. K.; Choong, V.; Choulis, S. A.; So, F.; Winnacker, A.
2006-09-01
The external light output of organic light emitting diodes (OLEDs) can be increased by modifying the light emitting surface. The apparent light extraction enhancement is given by the ratio between the efficiency of the unmodified device and the efficiency of the modified device. This apparent light extraction enhancement is dependent on the OLED architecture itself and is not the correct value to judge the effectiveness of a technique to enhance light outcoupling due to substrate surface modification. We propose a general method to evaluate substrate surface modification techniques for light extraction enhancement of OLEDs independent from the device architecture. This method is experimentally demonstrated using green electrophosphorescent OLEDs with different device architectures. The substrate surface of these OLEDs was modified by applying a prismatic film to increase light outcoupling from the device stack. It was demonstrated that the conventionally measured apparent light extraction enhancement by means of the prismatic film does not reflect the actual performance of the light outcoupling technique. Rather, by comparing the light extracted out of the prismatic film to that generated in the OLED layers and coupled into the substrate (before the substrate/air interface), a more accurate evaluation of light outcoupling enhancement can be achieved. Furthermore we show that substrate surface modification can change the output spectrum of a broad band emitting OLED.
Liu, Chenwei; Shea, Nancy; Rucker, Sally; Harvey, Linda; Russo, Paul; Saul, Richard; Lopez, Mary F; Mikulskis, Alvydas; Kuzdzal, Scott; Golenko, Eva; Fishman, David; Vonderheid, Eric; Booher, Susan; Cowen, Edward W; Hwang, Sam T; Whiteley, Gordon R
2007-11-01
Proteomic patterns as a potential diagnostic technology has been well established for several cancer conditions and other diseases. The use of machine learning techniques such as decision trees, neural networks, genetic algorithms, and other methods has been the basis for pattern determination. Cancer is known to involve signaling pathways that are regulated through PTM of proteins. These modifications are also detectable with high confidence using high-resolution MS. We generated data using a prOTOF mass spectrometer on two sets of patient samples: ovarian cancer and cutaneous t-cell lymphoma (CTCL) with matched normal samples for each disease. Using the knowledge of mass shifts caused by common modifications, we built models using peak pairs and compared this to a conventional technique using individual peaks. The results for each disease showed that a small number of peak pairs gave classification equal to or better than the conventional technique that used multiple individual peaks. This simple peak picking technique could be used to guide identification of important peak pairs involved in the disease process.
Enhanced removal of nitrate from water using surface modification of adsorbents--a review.
Loganathan, Paripurnanda; Vigneswaran, Saravanamuthu; Kandasamy, Jaya
2013-12-15
Elevated concentration of nitrate results in eutrophication of natural water bodies affecting the aquatic environment and reduces the quality of drinking water. This in turn causes harm to people's health, especially that of infants and livestock. Adsorbents with the high capacity to selectively adsorb nitrate are required to effectively remove nitrate from water. Surface modifications of adsorbents have been reported to enhance their adsorption of nitrate. The major techniques of surface modification are: protonation, impregnation of metals and metal oxides, grafting of amine groups, organic compounds including surfactant coating of aluminosilicate minerals, and heat treatment. This paper reviews current information on these techniques, compares the enhanced nitrate adsorption capacities achieved by the modifications, and the mechanisms of adsorption, and presents advantages and drawbacks of the techniques. Most studies on this subject have been conducted in batch experiments. These studies need to include continuous mode column trials which have more relevance to real operating systems and pilot-plant trials. Reusability of adsorbents is important for economic reasons and practical treatment applications. However, only limited information is available on the regeneration of surface modified adsorbents. Copyright © 2013 Elsevier Ltd. All rights reserved.
Modifications to the NRAD Reactor, 1977 to present
DOE Office of Scientific and Technical Information (OSTI.GOV)
Weeks, A.A.; Pruett, D.P.; Heidel, C.C.
1986-01-01
Argonne National Laboratory-West, operated by the University of Chicago, is located near Idaho Falls, ID, on the Idaho National Engineering laboratory Site. ANL-West performs work in support of the Liquid Metal Fast Breeder Reactor Program (LMFBR) sponsored by the United States Department of Energy. The NRAD reactor is located at the Argonne Site within the Hot Fuel Examination Facility/North, a large hot cell facility where both non-destructive and destructive examinations are performed on highly irradiated reactor fuels and materials in support of the LMFBR program. The NRAD facility utilizes a 250-kW TRIGA reactor and is completely dedicated to neutron radiographymore » and the development of radiography techniques. Criticality was first achieved at the NRAD reactor in October of 1977. Since that time, a number of modifications have been implemented to improve operational efficiency and radiography production. This paper describes the modifications and changes that significantly improved operational efficiency and reliability of the reactor and the essential auxiliary reactor systems.« less
Modified surface of titanium dioxide nanoparticles-based biosensor for DNA detection
NASA Astrophysics Data System (ADS)
Nadzirah, Sh.; Hashim, U.; Rusop, M.
2018-05-01
A new technique was used to develop a simple and selective picoammeter DNA biosensor for identification of E. coli O157:H7. This biosensor was fabricated from titanium dioxide nanoparticles that was synthesized by sol-gel method and spin-coated on silicon dioxide substrate via spinner. 3-Aminopropyl triethoxy silane (APTES) was used to modify the surface of TiO2. Simple surface modification approach has been applied; which is single dropping of APTES onto the TiO2 nanoparticles surface. Carboxyl modified probe DNA has been bind onto the surface of APTES/TiO2 without any amplifier element. Electrical signal has been used as the indicator to differentiate each step (surface modification of TiO2 and probe DNA immobilization). The I-V measurements indicate extremely low current (pico-ampere) flow through the device which is 2.8138E-10 A for pure TiO2 nanoparticles, 2.8124E-10 A after APTES modification and 3.5949E-10 A after probe DNA immobilization.
Yoshizumi, Takeshi; Oikawa, Kazusato; Chuah, Jo-Ann; Kodama, Yutaka; Numata, Keiji
2018-05-14
Selective gene delivery into organellar genomes (mitochondrial and plastid genomes) has been limited because of a lack of appropriate platform technology, even though these organelles are essential for metabolite and energy production. Techniques for selective organellar modification are needed to functionally improve organelles and produce transplastomic/transmitochondrial plants. However, no method for mitochondrial genome modification has yet been established for multicellular organisms including plants. Likewise, modification of plastid genomes has been limited to a few plant species and algae. In the present study, we developed ionic complexes of fusion peptides containing organellar targeting signal and plasmid DNA for selective delivery of exogenous DNA into the plastid and mitochondrial genomes of intact plants. This is the first report of exogenous DNA being integrated into the mitochondrial genomes of not only plants, but also multicellular organisms in general. This fusion peptide-mediated gene delivery system is a breakthrough platform for both plant organellar biotechnology and gene therapy for mitochondrial diseases in animals.
ERIC Educational Resources Information Center
Habib, H. S.
A professor involved with the HELDS project (Higher Education for Learning Disabled Students) describes modifications in a general chemistry course. A syllabus lists program objectives for eight text chapters, evaluation components, and course rules. Two units are described in detail, with information presented on modifications made for LD…
[Cosmetic technique application on the modification of lip deformity after cleft lip surgery].
Lixian, Chen; Huajun, Wang; Caixia, Gong; Qian, Zheng; Bing, Shi; Bihe, Zhang
2018-02-01
This study aims to explore the effect of cosmetic technique on the modification of lip deformity after cleft lip surgery. A total of 35 patients with postoperative cleft lip and who needed two-stage repair due to the nasolabial deformity were selected. Cosmetic technique was used to modify their lip deformities prior to the surgery. Front photos of the patients were taken before and after modification of their lip deformities. These photos were subsequently assessed by both the patients and the medical staff. The visual analogue method, Asher-McDade aesthetic index, and Mortier PB scale were used by patients and medical staff to evaluate changes in the lip shape by the cosmetic technique. Prior to the cosmetic technique application, the mean self-score of the patients and the mean scores of the medical staff were 56±13 and 3.22±1.11 points, respectively. After the cosmetic technique application, the mean self-score of the patients and the mean scores of the medical staff were 67±12 and 2.85±1.03 points, respectively. The differences were statistically significant for both the patients and the medical staff (P<0.05). Appropriate use of the cosmetic technique can modify the lip deformity after the cleft lip surgery to a certain degree. The use of this technique exerts evident effects in restoring the symmetry of lip peak and the continuity of the labial arch and in highlighting the philtrum column.
Combination of DiOlistic Labeling with Retrograde Tract Tracing and Immunohistochemistry
Diana Neely, M.; Stanwood, Gregg D; Deutch, Ariel Y.
2009-01-01
Neuronal staining techniques have played a crucial role in the analysis of neuronal function. Several different staining techniques have been developed to allow morphological analyses of neurons. Recently diOlistic labeling, in which beads are coated with a lipophilic dye and then ballistically ejected onto brain tissue, has been developed as a useful and simple means to label neurons and glia in their entirety. Although diOlistic labeling provides detailed information on the morphology of neurons, combining this approach with other staining methods is a significant advance. We have developed protocols that result in high quality diOlistically- and retrogradely-labeled or diOlistically-immunohistochemically labeled neurons. These dual-label methods require modification of fixation parameters and the use of detergents for tissue permeabilization, and are readily applicable to a wide range of tracers and antibodies. PMID:19712695
Time-Distance Analysis of Deep Solar Convection
NASA Technical Reports Server (NTRS)
Duvall, T. L., Jr.; Hanasoge, S. M.
2011-01-01
Recently it was shown by Hanasoge, Duvall, and DeRosa (2010) that the upper limit to convective flows for spherical harmonic degrees l is considerably smaller than the flows predicted by the ASH simulations (Miesch et a7. ref) at the depth r/R=0.95 ' The deep-focusing Lime-distance technique used to develop the upper limit was applied to linear acoustic simulations of a solar interior perturbed by convective flows in order to calibrate the technique. This technique has been applied to other depths in the convection zone and the results will be presented. The deep-focusing technique has considerable sensitivity to the flow ' signals at the desired subsurface location ' However, as shown by Birch {ref}, there is remaining much sensitivity to near-surface signals. Modifications to the technique using multiple bounce signals have been examined in a search for a more refined sensitivity, or kernel function. Initial results are encouraging and results will be presented'
[The commonest therapeutic methods for laser irradiation of blood].
Moskvin, S V; Konchugova, T V; Khadartsev, A А
2017-12-05
One of the most widely employed methods of laser therapy is laser irradiation of blood (LIB). There are two modifications of this technique, one being intravenous low-intensity laser irradiation of blood (ILIB), the other non-invasive blood irradiation(NLIB). The two methods have been developing independently since either has its advantages and disadvantages. The present article was designed to review the main currently available techniques for laser irradiation of blood which are presented in the form of tables (charts). Replacing the UV irradiation of blood with UV lamps by laser ultraviolet irradiation of blood (LUVIB®) has made it possible to significantly simplify the technique and enhanced its efficiency. The most effective options for ILIB are the combined techniques: ILIB-635 + LUVIB® and ILIB-525 + LUVIB. The most effective technique for ELIB is believed to be the use of low-intensity pulsed laser light with a wavelength of 635 nm and output power up to 40 W.
NASA Astrophysics Data System (ADS)
Poulain, Pierre-Marie; Luther, Douglas S.; Patzert, William C.
1992-11-01
Two techniques have been developed for estimating statistics of inertial oscillations from satellite-tracked drifters. These techniques overcome the difficulties inherent in estimating such statistics from data dependent upon space coordinates that are a function of time. Application of these techniques to tropical surface drifter data collected during the NORPAX, EPOCS, and TOGA programs reveals a latitude-dependent, statistically significant "blue shift" of inertial wave frequency. The latitudinal dependence of the blue shift is similar to predictions based on "global" internal wave spectral models, with a superposition of frequency shifting due to modification of the effective local inertial frequency by the presence of strongly sheared zonal mean currents within 12° of the equator.
Performance and durability of high emittance heat receiver surfaces for solar dynamic power systems
NASA Technical Reports Server (NTRS)
Degroh, Kim K.; Roig, David M.; Burke, Christopher A.; Shah, Dilipkumar R.
1994-01-01
Haynes 188, a cobalt-based superalloy, will be used to make thermal energy storage (TES) containment canisters for a 2 kW solar dynamic ground test demonstrator (SD GTD). Haynes 188 containment canisters with a high thermal emittance (epsilon) are desired for radiating heat away from local hot spots, improving the heating distribution, which will in turn improve canister service life. In addition to needing a high emittance, the surface needs to be durable in an elevated temperature, high vacuum environment for an extended time period. Thirty-five Haynes 188 samples were exposed to 14 different types of surface modification techniques for emittance and vacuum heat treatment (VHT) durability enhancement evaluation. Optical properties were obtained for the modified surfaces. Emittance enhanced samples were exposed to VHT for up to 2692 hours at 827 C and less than or equal to 10(exp -6) torr with integral thermal cycling. Optical properties were taken intermittently during exposure, and after final VHT exposure. The various surface modification treatments increased the emittance of pristine Haynes 188 from 0.11 up to 0.86. Seven different surface modification techniques were found to provide surfaces which met the SD GTD receiver VHT durability requirement. Of the 7 surface treatments, 2 were found to display excellent VHT durability: an alumina based (AB) coating and a zirconia based coating. The alumina based coating was chosen for the epsilon enhancement surface modification technique for the SD GTD receiver. Details of the performance and vacuum heat treatment durability of this coating and other Haynes 188 emittance surface modification techniques are discussed. Technology from this program will lead to successful demonstration of solar dynamic power for space applications, and has potential for application in other systems requiring high emittance surfaces.
Impact of Dental Implant Surface Modifications on Osseointegration
Smeets, Ralf; Stadlinger, Bernd; Schwarz, Frank; Beck-Broichsitter, Benedicta; Jung, Ole; Precht, Clarissa; Kloss, Frank; Gröbe, Alexander; Heiland, Max
2016-01-01
Objective. The aim of this paper is to review different surface modifications of dental implants and their effect on osseointegration. Common marketed as well as experimental surface modifications are discussed. Discussion. The major challenge for contemporary dental implantologists is to provide oral rehabilitation to patients with healthy bone conditions asking for rapid loading protocols or to patients with quantitatively or qualitatively compromised bone. These charging conditions require advances in implant surface design. The elucidation of bone healing physiology has driven investigators to engineer implant surfaces that closely mimic natural bone characteristics. This paper provides a comprehensive overview of surface modifications that beneficially alter the topography, hydrophilicity, and outer coating of dental implants in order to enhance osseointegration in healthy as well as in compromised bone. In the first part, this paper discusses dental implants that have been successfully used for a number of years focusing on sandblasting, acid-etching, and hydrophilic surface textures. Hereafter, new techniques like Discrete Crystalline Deposition, laser ablation, and surface coatings with proteins, drugs, or growth factors are presented. Conclusion. Major advancements have been made in developing novel surfaces of dental implants. These innovations set the stage for rehabilitating patients with high success and predictable survival rates even in challenging conditions. PMID:27478833
Liang, Mingyu; Cowley, Allen W.; Mattson, David L.; Kotchen, Theodore A.; Liu, Yong
2013-01-01
Multiple genes and pathways are involved in the pathogenesis of hypertension. Epigenomic studies of hypertension are beginning to emerge and hold great promise of providing novel insights into the mechanisms underlying hypertension. Epigenetic marks or mediators including DNA methylation, histone modifications, and non-coding RNA can be studied at a genome or near-genome scale using epigenomic approaches. At the single gene level, several studies have identified changes in epigenetic modifications in genes expressed in the kidney that correlate with the development of hypertension. Systematic analysis and integration of epigenetic marks at the genome scale, demonstration of cellular and physiological roles of specific epigenetic modifications, and investigation of inheritance are among the major challenges and opportunities for future epigenomic and epigenetic studies of hypertension. Essential hypertension is a multifactorial disease involving multiple genetic and environmental factors and mediated by alterations in multiple biological pathways. Because the non-genetic mechanisms may involve epigenetic modifications, epigenomics is one of the latest concepts and approaches brought to bear on hypertension research. In this article, we summarize briefly the concepts and techniques for epigenomics, discuss the rationale for applying epigenomic approaches to study hypertension, and review the current state of this research area. PMID:24011581
ERIC Educational Resources Information Center
Elliott, Shannon Snyder
2007-01-01
The purpose of this study is to first develop an 8-week college teaching module based on root competition literature. The split-root technique is adapted for the teaching laboratory, and the Sugar Ann English pea (Pisum sativum var. Sugar Ann English) is selected as the species of interest prior to designing experiments, either original or…
NASA Technical Reports Server (NTRS)
Duran, E. N.; Lewis, G. W.; Feldstein, C.; Corday, E.; Meerbaum, S.; Lang, T.
1973-01-01
The results of a technology transfer of a miniature unidirectional stress transducer, developed for experimental stress analysis in the aerospace field, to applications in bioengineering are reported. By modification of the basic design and innovations in attachment techniques, the transducer was successfully used in vivo on the myocardium of large dogs to record the change in contractile force due to coronary occlusion, reperfusion, and intervention.
The NASTRAN theoretical manual
NASA Technical Reports Server (NTRS)
1981-01-01
Designed to accommodate additions and modifications, this commentary on NASTRAN describes the problem solving capabilities of the program in a narrative fashion and presents developments of the analytical and numerical procedures that underlie the program. Seventeen major sections and numerous subsections cover; the organizational aspects of the program, utility matrix routines, static structural analysis, heat transfer, dynamic structural analysis, computer graphics, special structural modeling techniques, error analysis, interaction between structures and fluids, and aeroelastic analysis.
Cost Savings Potential of Modification to the Standard Light Rail Vehicle Specification
DOT National Transportation Integrated Search
1979-02-01
This report describes an assessment of the Standard Light Rail Vehicle (SLRV) specification to determine whether the relaxation or modification of some requirements could result in a significant reduction in vehicle costs. A Technique of Assessment b...
On the Teaching of a Self-Modification Course
ERIC Educational Resources Information Center
Tasto, Donald L.
1976-01-01
Discusses teaching techniques, course content, strategies, and problems of teaching a behavior modification course to university students. Course target areas include subjects such as anxiety control, fear elimination, weight control, smoking reduction, interpersonal interaction, assertiveness, and exercise maintenance. (Author/DB)
SiC JFET Transistor Circuit Model for Extreme Temperature Range
NASA Technical Reports Server (NTRS)
Neudeck, Philip G.
2008-01-01
A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation Program with Integrated Circuit Emphasis (SPICE) general-purpose analog-integrated-circuit-simulating software. NGSPICE in its unmodified form is used for simulating and designing circuits made from silicon-based transistors that operate at or near room temperature. Two rapid modifications of NGSPICE source code enable SiC JFETs to be simulated to 500 C using the well-known Level 1 model for silicon metal oxide semiconductor field-effect transistors (MOSFETs). First, the default value of the MOSFET surface potential must be changed. In the unmodified source code, this parameter has a value of 0.6, which corresponds to slightly more than half the bandgap of silicon. In NGSPICE modified to simulate SiC JFETs, this parameter is changed to a value of 1.6, corresponding to slightly more than half the bandgap of SiC. The second modification consists of changing the temperature dependence of MOSFET transconductance and saturation parameters. The unmodified NGSPICE source code implements a T(sup -1.5) temperature dependence for these parameters. In order to mimic the temperature behavior of experimental SiC JFETs, a T(sup -1.3) temperature dependence must be implemented in the NGSPICE source code. Following these two simple modifications, the Level 1 MOSFET model of the NGSPICE circuit simulation program reasonably approximates the measured high-temperature behavior of experimental SiC JFETs properly operated with zero or reverse bias applied to the gate terminal. Modification of additional silicon parameters in the NGSPICE source code was not necessary to model experimental SiC JFET current-voltage performance across the entire temperature range from 25 to 500 C.
Laparoscopic (endoscopic) radical prostatectomy: techniques and results
NASA Astrophysics Data System (ADS)
Nelius, Thomas; de Riese, Werner T. W.; Reiher, Frank; Lindenmeir, Tobias; Filleur, Stephanie; Allhoff, Ernst P.
2005-04-01
Laparoscopic radical prostatectomy (LRP) is a relatively new technique for treating organ-confined prostate cancer. Recent progress of laparoscopic/endoscopic techniques allow to perform these complex oncological procedure. Since the first description of LRP in the early 1990s the technique has undergone significant technical modifications. Two operation routes were mainly used: the transperitoneal LRP and the extraperitoneal endoscopic radical prostatectomy (EERPE). Here we review the surgical techniques of both operation routes, and highlight results, outcome and complications. The transperitoneal LRP and the EERPE can be used successfully and reproducibly, giving results comparable with those from the open retropubic procedure. Despite many advantages, transperitoneal LRP is associated with potential intraperitoneal complications. The technical improvements of the EERPE completely obviates these complications. The available data are encouraging and promising, but long-term oncological results will define the definitive role of these new techniques. We truly believe that minimally invasive surgery in treating localized prostate cancer has a bright future and that these techniques will continue to be developed.
Science and Bioethics of CRISPR-Cas9 Gene Editing: An Analysis Towards Separating Facts and Fiction.
Cribbs, Adam P; Perera, Sumeth M W
2017-12-01
Since its emergence in 2012, the genome editing technique known as CRISPR-Cas9 and its scientific use have rapidly expanded globally within a very short period of time. The technique consists of using an RNA guide molecule to bind to complementary DNA sequences, which simultaneously recruits the endonuclease Cas9 to introduce double-stranded breaks in the target DNA. The resulting double-stranded break is then repaired, allowing modification or removal of specific DNA bases. The technique has gained momentum in the laboratory because it is cheap, quick, and easy to use. Moreover, it is also being applied in vivo to generate more complex animal model systems. Such use of genome editing has proven to be highly effective and warrants a potential therapy for both genetic and non-genetic diseases. Although genome editing has the potential to be a transformative therapy for patients it is still in its infancy. Consequently, the legal and ethical frameworks are yet to be fully discussed and will be an increasingly important topic as the technology moves towards more contentious issues such as modification of the germline. Here, we review a number of scientific and ethical issues which may potentially influence the development of both the technology and its use in the clinical setting.
Science and Bioethics of CRISPR-Cas9 Gene Editing: An Analysis Towards Separating Facts and Fiction
Cribbs, Adam P.; Perera, Sumeth M. W.
2017-01-01
Since its emergence in 2012, the genome editing technique known as CRISPR-Cas9 and its scientific use have rapidly expanded globally within a very short period of time. The technique consists of using an RNA guide molecule to bind to complementary DNA sequences, which simultaneously recruits the endonuclease Cas9 to introduce double-stranded breaks in the target DNA. The resulting double-stranded break is then repaired, allowing modification or removal of specific DNA bases. The technique has gained momentum in the laboratory because it is cheap, quick, and easy to use. Moreover, it is also being applied in vivo to generate more complex animal model systems. Such use of genome editing has proven to be highly effective and warrants a potential therapy for both genetic and non-genetic diseases. Although genome editing has the potential to be a transformative therapy for patients it is still in its infancy. Consequently, the legal and ethical frameworks are yet to be fully discussed and will be an increasingly important topic as the technology moves towards more contentious issues such as modification of the germline. Here, we review a number of scientific and ethical issues which may potentially influence the development of both the technology and its use in the clinical setting. PMID:29259526
Genomic tools and and prospects for new breeding techniques in flower bulb crops
USDA-ARS?s Scientific Manuscript database
For many of the new breeding techniques, sequence information is of the utmost importance. In addition to current breeding techniques, such as marker-assisted selection (MAS) and genetic modification (GM), new breeding techniques such as zinc finger nucleases, oligonucleotide-mediated mutagenesis, R...
NASA Technical Reports Server (NTRS)
Dabney, James B.; Arthur, James Douglas
2017-01-01
Agile methods have gained wide acceptance over the past several years, to the point that they are now a standard management and execution approach for small-scale software development projects. While conventional Agile methods are not generally applicable to large multi-year and mission-critical systems, Agile hybrids are now being developed (such as SAFe) to exploit the productivity improvements of Agile while retaining the necessary process rigor and coordination needs of these projects. From the perspective of Independent Verification and Validation (IVV), however, the adoption of these hybrid Agile frameworks is becoming somewhat problematic. Hence, we find it prudent to question the compatibility of conventional IVV techniques with (hybrid) Agile practices.This paper documents our investigation of (a) relevant literature, (b) the modification and adoption of Agile frameworks to accommodate the development of large scale, mission critical systems, and (c) the compatibility of standard IVV techniques within hybrid Agile development frameworks. Specific to the latter, we found that the IVV methods employed within a hybrid Agile process can be divided into three groups: (1) early lifecycle IVV techniques that are fully compatible with the hybrid lifecycles, (2) IVV techniques that focus on tracing requirements, test objectives, etc. are somewhat incompatible, but can be tailored with a modest effort, and (3) IVV techniques involving an assessment requiring artifact completeness that are simply not compatible with hybrid Agile processes, e.g., those that assume complete requirement specification early in the development lifecycle.
Nanoscale Surface Modifications of Medical Implants for Cartilage Tissue Repair and Regeneration
Griffin, MF; Szarko, M; Seifailan, A; Butler, PE
2016-01-01
Background: Natural cartilage regeneration is limited after trauma or degenerative processes. Due to the clinical challenge of reconstruction of articular cartilage, research into developing biomaterials to support cartilage regeneration have evolved. The structural architecture of composition of the cartilage extracellular matrix (ECM) is vital in guiding cell adhesion, migration and formation of cartilage. Current technologies have tried to mimic the cell’s nanoscale microenvironment to improve implants to improve cartilage tissue repair. Methods: This review evaluates nanoscale techniques used to modify the implant surface for cartilage regeneration. Results: The surface of biomaterial is a vital parameter to guide cell adhesion and consequently allow for the formation of ECM and allow for tissue repair. By providing nanosized cues on the surface in the form of a nanotopography or nanosized molecules, allows for better control of cell behaviour and regeneration of cartilage. Chemical, physical and lithography techniques have all been explored for modifying the nanoscale surface of implants to promote chondrocyte adhesion and ECM formation. Conclusion: Future studies are needed to further establish the optimal nanoscale modification of implants for cartilage tissue regeneration. PMID:28217208
POLLUTANT CONTROL TECHNIQUES FOR PACKAGE BOILERS: HARDWARE MODIFICATIONS AND ALTERNATE FUELS
The report gives results of investigations of four ways to control nitrogen oxide (NOx) emissions from package boilers (both field operating boilers and boiler simulators): (1) variations in combustor operating procedure; (2) combustion modification (flue gas recirculation and st...
The expanding role of mass spectrometry in the field of vaccine development.
Sharma, Vaneet Kumar; Sharma, Ity; Glick, James
2018-05-31
Biological mass spectrometry has evolved as a core analytical technology in the last decade mainly because of its unparalleled ability to perform qualitative as well as quantitative profiling of enormously complex biological samples with high mass accuracy, sensitivity, selectivity and specificity. Mass spectrometry-based techniques are also routinely used to assess glycosylation and other post-translational modifications, disulfide bond linkage, and scrambling as well as for the detection of host cell protein contaminants in the field of biopharmaceuticals. The role of mass spectrometry in vaccine development has been very limited but is now expanding as the landscape of global vaccine development is shifting towards the development of recombinant vaccines. In this review, the role of mass spectrometry in vaccine development is presented, some of the ongoing efforts to develop vaccines for diseases with global unmet medical need are discussed and the regulatory challenges of implementing mass spectrometry techniques in a quality control laboratory setting are highlighted. © 2018 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc.
Yellow fever vector live-virus vaccines: West Nile virus vaccine development.
Arroyo, J; Miller, C A; Catalan, J; Monath, T P
2001-08-01
By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus.
Second Aerospace Environmental Technology Conference
NASA Technical Reports Server (NTRS)
Whitaker, A. F. (Editor); Clark-Ingram, M. (Editor)
1997-01-01
The mandated elimination of CFC'S, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application, verification, compliant coatings including corrosion protection system and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.
A progress report on the development of an augmentor wing jet STOL research aircraft.
NASA Technical Reports Server (NTRS)
Quigley, H. C.; Sinclair, S. R. M.; Nark, T. C., Jr.; O'Keefe, J. V.
1971-01-01
The development of the aircraft has progressed to the point where the design of the modifications to the de Havilland C-8A Buffalo is complete and the engines are being tested. The predicted performance shows that the aircraft will be able to take off and land in less than 1500 ft. Simulation studies indicate that the handling qualities of the aircraft, with stability augmentation, will be acceptable for STOL research missions. Special techniques were required, however, for flight path control and transition from cruise to landing configuration .
Second Aerospace Environmental Technology Conference
NASA Technical Reports Server (NTRS)
Whitaker, A. F.; Clark-Ingram, M.; Hessler, S. L.
1997-01-01
The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.
NASA Technical Reports Server (NTRS)
Burnside, W. D.; Dominek, A. K.; Gupta, I. J.; Newman, E. H.; Pathak, P. H.; Peters, L., Jr.
1987-01-01
The ultimate goal is to generate experimental techniques and computer codes of rather general capability that would enable the aerospace industry to evaluate the scattering properties of aerodynamic shapes. Another goal involves developing an understanding of scattering mechanisms so that modification of the vehicular structure could be introduced within constraints set by aerodynamics. The development of indoor scattering measurement systems with special attention given to the compact range is another goal. There has been considerable progress in advancing state-of-the-art scattering measurements and control and analysis of the electromagnetic scattering from general targets.
BAC Modification through Serial or Simultaneous Use of CRE/Lox Technology
Parrish, Mark; Unruh, Jay; Krumlauf, Robb
2011-01-01
Bacterial Artificial Chromosomes (BACs) are vital tools in mouse genomic analyses because of their ability to propagate large inserts. The size of these constructs, however, prevents the use of conventional molecular biology techniques for modification and manipulation. Techniques such as recombineering and Cre/Lox methodologies have thus become heavily relied upon for such purposes. In this work, we investigate the applicability of Lox variant sites for serial and/or simultaneous manipulations of BACs. We show that Lox spacer mutants are very specific, and inverted repeat variants reduce Lox reaction rates through reducing the affinity of Cre for the site, while retaining some functionality. Employing these methods, we produced serial modifications encompassing four independent changes which generated a mouse HoxB BAC with fluorescent reporter proteins inserted into four adjacent Hox genes. We also generated specific, simultaneous deletions using combinations of spacer variants and inverted repeat variants. These techniques will facilitate BAC manipulations and open a new repertoire of methods for BAC and genome manipulation. PMID:21197414
Cui, Yubao; Yu, Lili
2016-12-01
The clustered regularly-interspaced short palindromic repeats (CRISPR) structural family functions as an acquired immune system in prokaryotes. Gene editing techniques have co-opted CRISPR and the associated Cas nucleases to allow for the precise genetic modification of human cells, zebrafish, mice, and other eukaryotes. Indeed, this approach has been used to induce a variety of modifications including directed insertion/deletion (InDel) of bases, gene knock-in, introduction of mutations in both alleles of a target gene, and deletion of small DNA fragments. Thus, CRISPR technology offers a precise molecular tool for directed genome modification with a range of potential applications; further, its high mutation efficiency, simple process, and low cost provide additional advantages over prior editing techniques. This paper will provide an overview of the basic structure and function of the CRISPR gene editing system as well as current and potential applications to research on parasites. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Structural characterization of thioether-bridged bacteriocins.
Lohans, Christopher T; Vederas, John C
2014-01-01
Bacteriocins are a group of ribosomally synthesized antimicrobial peptides produced by bacteria, some of which are extensively post-translationally modified. Some bacteriocins, namely the lantibiotics and sactibiotics, contain one or more thioether bridges. However, these modifications complicate the structural elucidation of these bacteriocins using conventional techniques. This review will discuss the techniques and strategies that have been applied to determine the primary structures of lantibiotics and sactibiotics. A major challenge is to identify the topology of thioether bridges in these peptides (i.e., which amino-acid residues are involved in which bridges). Edman degradation, NMR spectroscopy and tandem MS have all been commonly applied to characterize these bacteriocins, but can be incompatible with the post-translational modifications present. Chemical modifications to the modified residues, such as desulfurization and reduction, make the treated bacteriocins more compatible to analysis by these standard peptide analytical techniques. Despite their differences in structure, similar strategies have proved useful to study the structures of both lantibiotics and sactibiotics.
Detection of cavitation vortex in hydraulic turbines using acoustic techniques
NASA Astrophysics Data System (ADS)
Candel, I.; Bunea, F.; Dunca, G.; Bucur, D. M.; Ioana, C.; Reeb, B.; Ciocan, G. D.
2014-03-01
Cavitation phenomena are known for their destructive capacity in hydraulic machineries and are caused by the pressure decrease followed by an implosion when the cavitation bubbles find an adverse pressure gradient. A helical vortex appears in the turbine diffuser cone at partial flow rate operation and can be cavitating in its core. Cavity volumes and vortex frequencies vary with the under-pressure level. If the vortex frequency comes close to one of the eigen frequencies of the turbine, a resonance phenomenon may occur, the unsteady fluctuations can be amplified and lead to important turbine and hydraulic circuit damage. Conventional cavitation vortex detection techniques are based on passive devices (pressure sensors or accelerometers). Limited sensor bandwidths and low frequency response limit the vortex detection and characterization information provided by the passive techniques. In order to go beyond these techniques and develop a new active one that will remove these drawbacks, previous work in the field has shown that techniques based on acoustic signals using adapted signal content to a particular hydraulic situation, can be more robust and accurate. The cavitation vortex effects in the water flow profile downstream hydraulic turbines runner are responsible for signal content modifications. Basic signal techniques use narrow band signals traveling inside the flow from an emitting transducer to a receiving one (active sensors). Emissions of wide band signals in the flow during the apparition and development of the vortex embeds changes in the received signals. Signal processing methods are used to estimate the cavitation apparition and evolution. Tests done in a reduced scale facility showed that due to the increasing flow rate, the signal -- vortex interaction is seen as modifications on the received signal's high order statistics and bandwidth. Wide band acoustic transducers have a higher dynamic range over mechanical elements; the system's reaction time is reduced, resulting in a faster detection of the unwanted effects. The paper will present an example of this new investigation technique on a vortex generator in the test facility that belongs to ICPE- CA.
Chemical vapor deposition growth
NASA Technical Reports Server (NTRS)
Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.
1976-01-01
The chemical vapor deposition (CVD) method for the growth of Si sheet on inexpensive substrate materials is investigated. The objective is to develop CVD techniques for producing large areas of Si sheet on inexpensive substrate materials, with sheet properties suitable for fabricating solar cells meeting the technical goals of the Low Cost Silicon Solar Array Project. Specific areas covered include: (1) modification and test of existing CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using standard and near-standard processing techniques.
Recombinant organisms for production of industrial products.
Adrio, Jose-Luis; Demain, Arnold L
2010-01-01
A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding techniques and their modifications are contributing greatly to the development of improved industrial processes. In addition, functional genomics, proteomics and metabolomics are being exploited for the discovery of novel valuable small molecules for medicine as well as enzymes for catalysis. The sequencing of industrial microbal genomes is being carried out which bodes well for future process improvement and discovery of new industrial products. © 2010 Landes Bioscience
Finite element analysis using NASTRAN applied to helicopter transmission vibration/noise reduction
NASA Technical Reports Server (NTRS)
Howells, R. W.; Sciarra, J. J.
1975-01-01
A finite element NASTRAN model of the complete forward rotor transmission housing for the Boeing Vertol CH-47 helicopter was developed and applied to reduce transmission vibration/noise at its source. In addition to a description of the model, a technique for vibration/noise prediction and reduction is outlined. Also included are the dynamic response as predicted by NASTRAN, test data, the use of strain energy methods to optimize the housing for minimum vibration/noise, and determination of design modifications which will be manufactured and tested. The techniques presented are not restricted to helicopters but are applicable to any power transmission system. The transmission housing model developed can be used further to evaluate static and dynamic stresses, thermal distortions, deflections and load paths, fail-safety/vulnerability, and composite materials.
Positions for percutaneous nephrolithotomy: Thirty-five years of evolution
Karaolides, Theocharis; Moraitis, Konstantinos; Bach, Christian; Masood, Junaid; Buchholz, Noor
2012-01-01
Objectives To present the chronological development of the different positions described for percutaneous nephrolithotomy (PCNL), in an attempt to identify the reasons for their development and to highlight their specific advantages and disadvantages. Methods Previous reports were identified by a non-systematic search of Medline and Scopus. Results The classic prone position for PCNL was first described in 1976. The technique was gradually standardised and PCNL with the patient prone became the generally accepted standard approach. In the next 35 years many other positions were described, with the patient placed prone, lateral or supine in various modifications. Modifications of the classic prone position in the early 1990s aimed to provide the option of a simultaneous retrograde approach during the procedure. As PCNL became more popular the lateral position was first described in 1994, to allow the application of PCNL to patients who were unable to tolerate being prone because of their body habitus. The supine position for percutaneous access was originally described even before 1990, but become more popular after 2007 when the Galdakao modification was reported. Several other modifications of the supine position have been described, with the latest being the flank-free modified supine position, which allows the best exposure of the flank among the supine positions. Each position has its specific advantages and disadvantages. Conclusion Urologists who perform PCNL should be familiar with the differences in the positions and be able to use the method appropriate to each case. PMID:26558042
Surgical approaches for atrial fibrillation.
Schouchoff, Barbara
2007-01-01
The Cox Maze procedure, a cardiac intervention that was developed by James Cox, MD, was first performed in 1988 to surgically cure atrial fibrillation. Over the years, changes in techniques of the classic maze were made, culminating in the Cox Maze III procedure, the Gold Standard. Modifications in the original procedure included simplifying the procedure to a minimally invasive approach. As a result of some of these modifications, the initial maze-like series of surgical atrial incisions has been reduced with the use of alternate energy sources that create hyperthermic lesion lines of conduction block that isolate and interrupt the abnormal impulses. The minimize, a minimally invasive thorascopic approach, can be performed off pump, thus avoiding a median sternotomy and cardiopulmonary bypass and cardioplegic arrest intraoperatively and ensuring a shorter, less painful recovery.
Reduction of aircraft gas turbine engine pollutant emissions
NASA Technical Reports Server (NTRS)
Diehl, L. A.
1978-01-01
To accomplish simultaneous reduction of unburned hydrocarbons, carbon monoxide, and oxides of nitrogen, required major modifications to the combustor. The modification most commonly used was a staged combustion technique. While these designs are more complicated than production combustors, no insurmountable operational difficulties were encountered in either high pressure rig or engine tests which could not be resolved with additional normal development. The emission reduction results indicate that reductions in unburned hydrocarbons were sufficient to satisfy both near and far-termed EPA requirements. Although substantial reductions were observed, the success in achieving the CO and NOx standards was mixed and depended heavily on the engine/engine cycle on which it was employed. Technology for near term CO reduction was satisfactory or marginally satisfactory. Considerable doubt exists if this technology will satisfy all far-term requirements.
Simultaneous Surface Modification and Chemical Reduction of Graphene Oxide Using Glucose.
Pan, Hui; Liu, Ruiqi; Li, Guanglong; Wang, Xiaodong; Ding, Tao
2018-05-01
In this paper, we develop a simple and facile approach to prepare graphene nanosheets through chemical reduction with glucose as reducing agent and modification agent. The reduced and modified graphene by glucose (denoted as g-rGO) was characterized with techniques of Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectra, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), etc. It is found that, besides the desired reduction capability to graphene oxide (denoted as GO), glucose plays an important role as a modifying reagent in stabilizing the as-prepared graphene nanosheets simultaneously and the g-rGO exhibits good dispersibility and stability in water and waterborne polyurethane matrix (denoted as WPU). Moreover, the g-rGO can improve evidently the mechanical properties, weather ability and water resistance of WPU.
Epigenome analysis of pluripotent stem cells
Ricupero, Christopher L.; Swerdel, Mavis R.; Hart, Ronald P.
2015-01-01
Summary Mis-regulation of gene expression due to epigenetic abnormalities has been linked with complex genetic disorders, psychiatric illness and cancer. In addition, the dynamic epigenetic changes that occur in pluripotent stem cells are believed to impact regulatory networks essential for proper lineage development. Chromatin immunoprecipitation (ChIP) is a technique used to isolate and enrich chromatin fragments using antibodies against specific chromatin modifications, such as DNA binding proteins or covalent histone modifications. Until recently, many ChIP protocols required millions of cells for each immunoprecipitation. This severely limited analysis of rare cell populations or post-mitotic, differentiated cell lines. Here, we describe a low cell number ChIP protocol with next generation sequencing and analysis, that has the potential to uncover novel epigenetic regulatory pathways that were previously difficult or impossible to obtain. PMID:23546758
NASA Technical Reports Server (NTRS)
1991-01-01
The second phase of a task is described which has the ultimate purpose of ensuring that adequate Expert Systems (ESs) Verification and Validation (V and V) tools and techniques are available for Space Station Freedom Program Knowledge Based Systems development. The purpose of this phase is to recommend modifications to current software V and V requirements which will extend the applicability of the requirements to NASA ESs.
Enhancing the Breadth and Efficacy of Therapeutic Vaccines for Breast Cancer
2014-10-01
sequence data produced by the Slansky team following their single-cell emulsion RT-PCR technique; however, it can be packaged and shared for use...cell emulsion RT-PCR. Additional modifications were made to our epitope discovery workflow to increase efficacy of transcript and neoantigen candidate...the MiTCR [8] open source software package developed by MiLaboratory. MiTCR is a highly efficient and fast approach to CDR3 extraction, clonotype
Feasibility of MOS Task Analysis and Redesign to Reduce Physical Demands in the U.S. Army
1997-12-01
developed to study perchery workers (Scott & Lamb , 1996). Another posture analysis technique is called postural targeting (Corlett, et al., 1979). A...method which had been successfully applied to a variety of situations (Lee & Chiou, 1995; Scott & Lamb , 1996). Some modifications were made in the...Scott, G.B., & Lamb , N.R. (1996). Working practices in a perchery system, using the Ovako Working Posture Analyzing System (OWAS). Applied Ergonomics
The comet assay: Reflections on its development, evolution and applications.
Singh, Narendra P
2016-01-01
The study of DNA damage and its repair is critical to our understanding of human aging and cancer. This review reflects on the development of a simple technique, now known as the comet assay, to study the accumulation of DNA damage and its repair. It describes my journey into aging research and the need for a method that sensitively quantifies DNA damage on a cell-by-cell basis and on a day-by-day basis. My inspirations, obstacles and successes on the path to developing this assay and improving its reliability and sensitivity are discussed. Recent modifications, applications, and the process of standardizing the technique are also described. What was once untried and unknown has become a technique used around the world for understanding and monitoring DNA damage. The comet assay's use has grown exponentially in the new millennium, as emphasis on studying biological phenomena at the single-cell level has increased. I and others have applied the technique across cell types (including germ cells) and species (including bacteria). As it enters new realms and gains clinical relevance, the comet assay may very well illuminate human aging and its prevention. Copyright © 2016. Published by Elsevier B.V.
Drug Solubility: Importance and Enhancement Techniques
Savjani, Ketan T.; Gajjar, Anuradha K.; Savjani, Jignasa K.
2012-01-01
Solubility, the phenomenon of dissolution of solute in solvent to give a homogenous system, is one of the important parameters to achieve desired concentration of drug in systemic circulation for desired (anticipated) pharmacological response. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. More than 40% NCEs (new chemical entities) developed in pharmaceutical industry are practically insoluble in water. Solubility is a major challenge for formulation scientist. Any drug to be absorbed must be present in the form of solution at the site of absorption. Various techniques are used for the enhancement of the solubility of poorly soluble drugs which include physical and chemical modifications of drug and other methods like particle size reduction, crystal engineering, salt formation, solid dispersion, use of surfactant, complexation, and so forth. Selection of solubility improving method depends on drug property, site of absorption, and required dosage form characteristics. PMID:22830056
Neuroanatomy: Cajal and after Cajal.
Jones, Edward G
2007-10-01
This essay commences with a consideration of the relative contributions of Cajal and Golgi to the study of the anatomy of the nervous system. It demonstrates the extent to which Cajal depended upon Golgi's work and how his modifications of the Golgi technique permitted a remarkable series of investigations in which the foundations of the neuron doctrine were laid and in which the intrinsic connectivity of virtually every part of the central nervous system was charted. Cajal's readiness to seize on and develop new techniques was one of the many keys to his success. After him, neuroanatomical studies tended to be focused more on long tract connectivity, using techniques such as those of Nissl and Marchi that had been in place before Cajal commenced his studies. Development of degeneration-based techniques of tracing connections in the late 1950s spearheaded a revolution in neuroanatomy while introduction of mixed aldehyde fixation made possible similarly intensive studies of the fine structure of the nervous system. At this time, the Golgi technique experienced a brief resurgence as neuroanatomists made efforts to bridge the gap between light and electron microscopy. Later developments in techniques for tracing connections included anterograde tracing by autoradiography and retrograde tracing by horseradish peroxidase. These were soon superseded by tracing techniques of increasing sensitivity and specificity that rely upon the cellular and molecular biology of neurons. Although neuroanatomy in its traditional form is perhaps no longer fashionable as a discipline, the techniques of neuroanatomy remain preeminent in many, perhaps all areas of neuroscience.
Texture Modification of the Shuttle Landing Facility Runway at Kennedy Space Center
NASA Technical Reports Server (NTRS)
Daugherty, Robert H.; Yager, Thomas J.
1997-01-01
This paper describes the test procedures and the criteria used in selecting an effective runway-surface-texture modification at the Kennedy Space Center (KSC) Shuttle Landing Facility (SLF) to reduce Orbiter tire wear. The new runway surface may ultimately result in an increase of allowable crosswinds for launch and landing operations. The modification allows launch and landing operations in 20-knot crosswinds, if desired. This 5-knot increase over the previous 15-knot limit drastically increases landing safety and the ability to make on-time launches to support missions in which Space Station rendezvous are planned. The paper presents the results of an initial (1988) texture modification to reduce tire spin-up wear and then describes a series of tests that use an instrumented ground-test vehicle to compare tire friction and wear characteristics, at small scale, of proposed texture modifications placed into the SLF runway surface itself. Based on these tests, three candidate surfaces were chosen to be tested at full-scale by using a highly modified and instrumented transport aircraft capable of duplicating full Orbiter landing profiles. The full-scale Orbiter tire testing revealed that tire wear could be reduced approximately by half with either of two candidates. The texture-modification technique using a Humble Equipment Company Skidabrader(trademark) shotpeening machine proved to be highly effective, and the entire SLF runway surface was modified in September 1994. The extensive testing and evaluation effort that preceded the selection of this particular surface-texture-modification technique is described herein.
Long gap esophageal atresia: lengthening technique and primary anastomosis.
Hadidi, Ahmed T; Hosie, Stuart; Waag, Karl-Ludwig
2007-10-01
The treatment of long gap esophageal atresia remains a major surgical challenge. The authors describe a modification of a lengthening technique based on tissue expansion to avoid sutures cutting through the esophagus. Between January 2004 and August 2006, 4 patients did not respond to stretching, and underwent this modified esophageal lengthening technique using silastic tubes. RESULTS AND FOLLOW-UP: All infants recovered and have an intact esophagus. All infants developed gastroesophageal reflux. Thal antireflux procedure was performed in the first infant. The other 3 patients were managed conservatively. Follow-up ranged between 6 and 34 months. The tissue expansion principle can be successfully applied in the esophagus through external traction. Silastic tube fixation at esophageal ends may help to apply even traction and avoid sutures cutting through the esophageal tissue.
Kahlert, Daniela; Unyi-Reicherz, Annelie; Stratton, Gareth; Meinert Larsen, Thomas; Fogelholm, Mikael; Raben, Anne; Schlicht, Wolfgang
2016-01-01
Losing excess body weight and preventing weight regain by changing lifestyle is a challenging but promising task to prevent the incidence of type-2 diabetes. To be successful, it is necessary to use evidence-based and theory-driven interventions, which also contribute to the science of behavior modification by providing a deeper understanding of successful intervention components. To develop a physical activity and dietary behavior modification intervention toolbox (PREMIT) that fulfills current requirements of being theory-driven and evidence-based, comprehensively described and feasible to evaluate. PREMIT is part of an intervention trial, which aims to prevent the onset of type-2 diabetes in pre-diabetics in eight clinical centers across the world by guiding them in changing their physical activity and dietary behavior through a group counseling approach. The program development took five progressive steps, in line with the Public Health Action Cycle: (1) Summing-up the intervention goal(s), target group and the setting, (2) uncovering the generative psychological mechanisms, (3) identifying behavior change techniques and tools, (4) preparing for evaluation and (5) implementing the intervention and assuring quality. PREMIT is based on a trans-theoretical approach referring to valid behavior modification theories, models and approaches. A major "product" of PREMIT is a matrix, constructed for use by onsite-instructors. The matrix includes objectives, tasks and activities ordered by periods. PREMIT is constructed to help instructors guide participants' behavior change. To ensure high fidelity and adherence of program-implementation across the eight intervention centers standardized operational procedures were defined and "train-the-trainer" workshops were held. In summary PREMIT is a theory-driven, evidence-based program carefully developed to change physical activity and dietary behaviors in pre-diabetic people.
Kahlert, Daniela; Unyi-Reicherz, Annelie; Stratton, Gareth; Meinert Larsen, Thomas; Fogelholm, Mikael; Raben, Anne; Schlicht, Wolfgang
2016-01-01
Background: Losing excess body weight and preventing weight regain by changing lifestyle is a challenging but promising task to prevent the incidence of type-2 diabetes. To be successful, it is necessary to use evidence-based and theory-driven interventions, which also contribute to the science of behavior modification by providing a deeper understanding of successful intervention components. Objective: To develop a physical activity and dietary behavior modification intervention toolbox (PREMIT) that fulfills current requirements of being theory-driven and evidence-based, comprehensively described and feasible to evaluate. PREMIT is part of an intervention trial, which aims to prevent the onset of type-2 diabetes in pre-diabetics in eight clinical centers across the world by guiding them in changing their physical activity and dietary behavior through a group counseling approach. Methods: The program development took five progressive steps, in line with the Public Health Action Cycle: (1) Summing-up the intervention goal(s), target group and the setting, (2) uncovering the generative psychological mechanisms, (3) identifying behavior change techniques and tools, (4) preparing for evaluation and (5) implementing the intervention and assuring quality. Results: PREMIT is based on a trans-theoretical approach referring to valid behavior modification theories, models and approaches. A major “product” of PREMIT is a matrix, constructed for use by onsite-instructors. The matrix includes objectives, tasks and activities ordered by periods. PREMIT is constructed to help instructors guide participants' behavior change. To ensure high fidelity and adherence of program-implementation across the eight intervention centers standardized operational procedures were defined and “train-the-trainer” workshops were held. In summary PREMIT is a theory-driven, evidence-based program carefully developed to change physical activity and dietary behaviors in pre-diabetic people. PMID:27559319
Genome engineering and gene expression control for bacterial strain development.
Song, Chan Woo; Lee, Joungmin; Lee, Sang Yup
2015-01-01
In recent years, a number of techniques and tools have been developed for genome engineering and gene expression control to achieve desired phenotypes of various bacteria. Here we review and discuss the recent advances in bacterial genome manipulation and gene expression control techniques, and their actual uses with accompanying examples. Genome engineering has been commonly performed based on homologous recombination. During such genome manipulation, the counterselection systems employing SacB or nucleases have mainly been used for the efficient selection of desired engineered strains. The recombineering technology enables simple and more rapid manipulation of the bacterial genome. The group II intron-mediated genome engineering technology is another option for some bacteria that are difficult to be engineered by homologous recombination. Due to the increasing demands on high-throughput screening of bacterial strains having the desired phenotypes, several multiplex genome engineering techniques have recently been developed and validated in some bacteria. Another approach to achieve desired bacterial phenotypes is the repression of target gene expression without the modification of genome sequences. This can be performed by expressing antisense RNA, small regulatory RNA, or CRISPR RNA to repress target gene expression at the transcriptional or translational level. All of these techniques allow efficient and rapid development and screening of bacterial strains having desired phenotypes, and more advanced techniques are expected to be seen. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
NASA Technical Reports Server (NTRS)
Etchberger, F. R.
1983-01-01
Reduction of skin friction drag by suction of boundary layer air to maintain laminar flow has been known since Prandtl's published work in 1904. The dramatic increases in fuel costs and the potential for periods of limited fuel availability provided the impetus to explore technologies to reduce transport aircraft fuel consumption. NASA sponsored the Aircraft Energy Efficiency (ACEE) program in 1976 to develop technologies to improve fuel efficiency. This report documents the Lockheed-Georgia Company accomplishments in designing and fabricating a leading-edge flight test article incorporating boundary layer suction slots to be flown by NASA on their modified JetStar aircraft. Lockheed-Georgia Company performed as the integration contractor to design the JetStar aircraft modification to accept both a Lockheed and a McDonnell Douglas flight test article. McDonnell Douglas uses a porous skin concept. The report describes aerodynamic analyses, fabrication techniques, JetStar modifications, instrumentation requirements, and structural analyses and testing for the Lockheed test article. NASA will flight test the two LFC leading-edge test articles in a simulated commercial environment over a 6 to 8 month period in 1984. The objective of the flight test program is to evaluate the effectiveness of LFC leading-edge systems in reducing skin friction drag and consequently improving fuel efficiency.
Current and cutting-edge interventions for the treatment of obese patients.
Vairavamurthy, Jenanan; Cheskin, Lawrence J; Kraitchman, Dara L; Arepally, Aravind; Weiss, Clifford R
2017-08-01
The number of people classified as obese, defined by the World Health Organization as having a body mass index ≥30, has been rising since the 1980s. Obesity is associated with comorbidities such as hypertension, diabetes mellitus, and nonalcoholic fatty liver disease. The current treatment paradigm emphasizes lifestyle modifications, including diet and exercise; however this approach produces only modest weight loss for many patients. When lifestyle modifications fail, the current "gold standard" therapy for obesity is bariatric surgery, including Roux-en-Y gastric bypass, sleeve gastrectomy, duodenal switch, and placement of an adjustable gastric band. Though effective, bariatric surgery can have severe short- and long-term complications. To fill the major gap in invasiveness between lifestyle modification and surgery, researchers have been developing pharmacotherapies and minimally invasive endoscopic techniques to treat obesity. Recently, interventional radiologists developed a percutaneous transarterial catheter-directed therapy targeting the hormonal function of the stomach. This review describes the current standard obesity treatments (including diet, exercise, and surgery), as well as newer endoscopic bariatric procedures and pharmacotherapies to help patients lose weight. We present data from two ongoing human trials of a new interventional radiology procedure for weight loss, bariatric embolization. Copyright © 2017 Elsevier B.V. All rights reserved.
Statistically qualified neuro-analytic failure detection method and system
Vilim, Richard B.; Garcia, Humberto E.; Chen, Frederick W.
2002-03-02
An apparatus and method for monitoring a process involve development and application of a statistically qualified neuro-analytic (SQNA) model to accurately and reliably identify process change. The development of the SQNA model is accomplished in two stages: deterministic model adaption and stochastic model modification of the deterministic model adaptation. Deterministic model adaption involves formulating an analytic model of the process representing known process characteristics, augmenting the analytic model with a neural network that captures unknown process characteristics, and training the resulting neuro-analytic model by adjusting the neural network weights according to a unique scaled equation error minimization technique. Stochastic model modification involves qualifying any remaining uncertainty in the trained neuro-analytic model by formulating a likelihood function, given an error propagation equation, for computing the probability that the neuro-analytic model generates measured process output. Preferably, the developed SQNA model is validated using known sequential probability ratio tests and applied to the process as an on-line monitoring system. Illustrative of the method and apparatus, the method is applied to a peristaltic pump system.
Infra-red technique for cerebral blood flow: comparison with /sup 133/Xenon clearance
DOE Office of Scientific and Technical Information (OSTI.GOV)
Colacino, J.M.; Grubb, B.; Joebsis, F.F.
A rapid infra-red optical technique has been developed for the measurement of cerebral blood flow. The method measures optical density changes across the intact skull during the passage of a bolus of the dye. Cardio-Green (CG). The clearance curves obtained for CG boluses are very short (less than 30 sec) in comparison with those obtained with tracers such as /sup 133/Xenon (10-30 min) that distribute into cerebral tissue. The volume of distribution of CG is totally intravascular, and the dye is relatively slowly cleared from the body. The important advantages of this spectrophotometric technique are its speed, versatility, and themore » avoidance of radioactive materials. The differential spectrophotometer used in this study, with trivial modifications, has been used to monitor changes in brain blood volume, oxygen saturation of hemoglobin, and cortical mitochondrial respiratory function, which illustrate the versatility of the technique for neurological assessments.« less
Psychodrama Techniques for Inservice Teacher Training
ERIC Educational Resources Information Center
Kohut, Sylvester, Jr.
1976-01-01
By using psychodrama techniques in inservice programming, improvement in communication among members of the school community occurs. With modification the psychodrama approach can be used with inservice teachers and administrators to improve self-realization and communication. A program using psychodrama techniques is described in the article.…
Social and ethical issues in mitochondrial donation
Dimond, Rebecca
2015-01-01
Introduction or background The UK is at the forefront of mitochondrial science and is currently the only country in the world to legalize germ-line technologies involving mitochondrial donation. However, concerns have been raised about genetic modification and the ‘slippery slope’ to designer babies. Sources of data This review uses academic articles, newspaper reports and public documents. Areas of agreement Mitochondrial donation offers women with mitochondrial disease an opportunity to have healthy, genetically related children. Areas of controversy Key areas of disagreement include safety, the creation of three-parent babies, impact on identity, implications for society, definitions of genetic modification and reproductive choice. Growing points The UK government legalized the techniques in March 2015. Scientific and medical communities across the world followed the developments with interest. Areas timely for developing research It is expected that the first cohort of ‘three parent’ babies will be born in the UK in 2016. Their health and progress will be closely monitored. PMID:26351372
Surface modification effects on defect-related photoluminescence in colloidal CdS quantum dots.
Lee, TaeGi; Shimura, Kunio; Kim, DaeGwi
2018-05-03
We investigated the effects of surface modification on the defect-related photoluminescence (PL) band in colloidal CdS quantum dots (QDs). A size-selective photoetching process and a surface modification technique with a Cd(OH)2 layer enabled the preparation of size-controlled CdS QDs with high PL efficiency. The Stokes shift of the defect-related PL band before and after the surface modification was ∼1.0 eV and ∼0.63 eV, respectively. This difference in the Stokes shifts suggests that the origin of the defect-related PL band was changed by the surface modification. Analysis by X-ray photoelectron spectroscopy revealed that the surface of the CdS QDs before and after the surface modification was S rich and Cd rich, respectively. These results suggest that Cd-vacancy acceptors and S-vacancy donors affect PL processes in CdS QDs before and after the surface modification, respectively.
Mapping Base Modifications in DNA by Transverse-Current Sequencing
NASA Astrophysics Data System (ADS)
Alvarez, Jose R.; Skachkov, Dmitry; Massey, Steven E.; Kalitsov, Alan; Velev, Julian P.
2018-02-01
Sequencing DNA modifications and lesions, such as methylation of cytosine and oxidation of guanine, is even more important and challenging than sequencing the genome itself. The traditional methods for detecting DNA modifications are either insensitive to these modifications or require additional processing steps to identify a particular type of modification. Transverse-current sequencing in nanopores can potentially identify the canonical bases and base modifications in the same run. In this work, we demonstrate that the most common DNA epigenetic modifications and lesions can be detected with any predefined accuracy based on their tunneling current signature. Our results are based on simulations of the nanopore tunneling current through DNA molecules, calculated using nonequilibrium electron-transport methodology within an effective multiorbital model derived from first-principles calculations, followed by a base-calling algorithm accounting for neighbor current-current correlations. This methodology can be integrated with existing experimental techniques to improve base-calling fidelity.
AN ANALYSIS OF THE INFLUENCE OF ANNUAL THERMAL VARIABLES ON THE OCCURRENCE OF WARM WATER FISHES
A potential effect of climate change is modification of the geographic distribution of fish species. To predict this modification it is necessary to estimate temperature tolerances of fishes and then relate these tolerances to the changing environment. This technique will allow...
Changing Attitudes Through Behavior Modification.
ERIC Educational Resources Information Center
Whipple, W. Scott
This article describes the philosophy and methods used by the staff at the Granite Alternative School in changing student attitudes through behavior modification. The students involved all have a failure syndrome or low self-image, and are dropouts from traditional high schools. Among the techniques used are: (1) reinforcing good behavior (praise…
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-07
... Modifications To Reduce Turtle Interactions AGENCY: National Marine Fisheries Service (NMFS), National Oceanic... Pacific green sea turtles. DATES: Comments on the proposed rule must be received by July 22, 2011... sea turtles, seabirds, and marine mammals. Fishermen must use specific equipment and techniques for...
Event- and Time-Driven Techniques Using Parallel CPU-GPU Co-processing for Spiking Neural Networks
Naveros, Francisco; Garrido, Jesus A.; Carrillo, Richard R.; Ros, Eduardo; Luque, Niceto R.
2017-01-01
Modeling and simulating the neural structures which make up our central neural system is instrumental for deciphering the computational neural cues beneath. Higher levels of biological plausibility usually impose higher levels of complexity in mathematical modeling, from neural to behavioral levels. This paper focuses on overcoming the simulation problems (accuracy and performance) derived from using higher levels of mathematical complexity at a neural level. This study proposes different techniques for simulating neural models that hold incremental levels of mathematical complexity: leaky integrate-and-fire (LIF), adaptive exponential integrate-and-fire (AdEx), and Hodgkin-Huxley (HH) neural models (ranged from low to high neural complexity). The studied techniques are classified into two main families depending on how the neural-model dynamic evaluation is computed: the event-driven or the time-driven families. Whilst event-driven techniques pre-compile and store the neural dynamics within look-up tables, time-driven techniques compute the neural dynamics iteratively during the simulation time. We propose two modifications for the event-driven family: a look-up table recombination to better cope with the incremental neural complexity together with a better handling of the synchronous input activity. Regarding the time-driven family, we propose a modification in computing the neural dynamics: the bi-fixed-step integration method. This method automatically adjusts the simulation step size to better cope with the stiffness of the neural model dynamics running in CPU platforms. One version of this method is also implemented for hybrid CPU-GPU platforms. Finally, we analyze how the performance and accuracy of these modifications evolve with increasing levels of neural complexity. We also demonstrate how the proposed modifications which constitute the main contribution of this study systematically outperform the traditional event- and time-driven techniques under increasing levels of neural complexity. PMID:28223930
Prevention of Unilateral Pulmonary Edema Complicating Robotic Mitral Valve Operations.
Moss, Emmanuel; Halkos, Michael E; Binongo, Jose N; Murphy, Douglas A
2017-01-01
Unilateral pulmonary edema (UPE) has been reported after mitral operations performed through the right side of the chest. The clinical presentation is compatible with an ischemia-reperfusion injury. This report describes modifications to robotic mitral valve operations that were designed to reduce UPE. We reviewed 15 patients with UPE after robotic mitral valve operations from 2006 through 2012. Technique modifications to reduce right lung ischemia were used from 2013 through June 2015. Modifications included alterations in patient position, ventilation, and perfusion factors. The incidence of UPE before and after modifications was determined, as was perfusion factors and outcomes in a higher-risk patient subgroup with pulmonary hypertension and prolonged bypass procedures. The incidence of UPE was 1.4% (n = 15) in 1,059 consecutive robotic mitral valve procedures using the standard technique and 0.0% in 435 consecutive procedures using the modified technique (p < 0.02). All patients with UPE had pulmonary hypertension and bypass times of greater than 120 minutes. Patients in the higher-risk subgroup had significantly lower systemic temperature (31°C [range, 30°-32°C] versus 34°C [range, 33°-34°C]; p < 0.01) and higher mean perfusion pressure (67mm Hg [range 62-72 mm Hg] versus 54 mm Hg [range, 52-57 mm Hg]; p < 0.01) on bypass using the modified technique. The incidence of UPE in higher-risk patients was significantly reduced using the modified technique (0% versus 5.6%; p < 0.01) without any increase in overall morbidity or mortality. The incidence of UPE in patients undergoing robotic mitral valve operations has been significantly reduced using a modified technique, without increasing the perioperative complication rate. Further work is necessary to validate this protocol and understand the pathophysiology of postoperative UPE. Copyright © 2017 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
ICE911 Research: Preserving and Rebuilding Reflective Ice
NASA Astrophysics Data System (ADS)
Field, L. A.; Chetty, S.; Manzara, A.; Venkatesh, S.
2014-12-01
We have developed a localized surface albedo modification technique that shows promise as a method to increase reflective multi-year ice using floating materials, chosen so as to have low subsidiary environmental impact. It is now well-known that multi-year reflective ice has diminished rapidly in the Arctic over the past 3 decades and this plays a part in the continuing rapid decrease of summer-time ice. As summer-time bright ice disappears, the Arctic is losing its ability to reflect summer insolation, and this has widespread climatic effects, as well as a direct effect on sea level rise, as oceans heat and once-land-based ice melts into the sea. We have tested the albedo modification technique on a small scale over six Winter/Spring seasons at sites including California's Sierra Nevada Mountains, a Canadian lake, and a small man-made lake in Minnesota, using various materials and an evolving array of instrumentation. The materials can float and can be made to minimize effects on marine habitat and species. The instrumentation is designed to be deployed in harsh and remote locations. Localized snow and ice preservation, and reductions in water heating, have been quantified in small-scale testing. We have continued to refine our material and deployment approaches, and we have had laboratory confirmation by NASA. In the field, the materials were successfully deployed to shield underlying snow and ice from melting; applications of granular materials remained stable in the face of local wind and storms. We are evaluating the effects of snow and ice preservation for protection of infrastructure and habitat stabilization, and we are concurrently developing our techniques to aid in water conservation. Localized albedo modification options such as those being studied in this work may act to preserve ice, glaciers, permafrost and seasonal snow areas, and perhaps aid natural ice formation processes. If this method is deployed on a large enough scale, it could conceivably bring about a reduction in the Ice-Albedo Feedback Effect, possibly slowing one of the key effects and factors in climate change.
Butterworth, C J; Rogers, S N
2017-12-01
This aim of this report is to describe the development and evolution of a new surgical technique for the immediate surgical reconstruction and rapid post-operative prosthodontic rehabilitation with a fixed dental prosthesis following low-level maxillectomy for malignant disease.The technique involves the use of a zygomatic oncology implant perforated micro-vascular soft tissue flap (ZIP flap) for the primary management of maxillary malignancy with surgical closure of the resultant maxillary defect and the installation of osseointegrated support for a zygomatic implant-supported maxillary fixed dental prosthesis.The use of this technique facilitates extremely rapid oral and dental rehabilitation within a few weeks of resective surgery, providing rapid return to function and restoring appearance following low-level maxillary resection, even in cases where radiotherapy is required as an adjuvant treatment post-operatively. The ZIP flap technique has been adopted as a standard procedure in the unit for the management of low-level maxillary malignancy, and this report provides a detailed step-by-step approach to treatment and discusses modifications developed over the treatment of an initial cohort of patients.
Genome Engineering and Modification Toward Synthetic Biology for the Production of Antibiotics.
Zou, Xuan; Wang, Lianrong; Li, Zhiqiang; Luo, Jie; Wang, Yunfu; Deng, Zixin; Du, Shiming; Chen, Shi
2018-01-01
Antibiotic production is often governed by large gene clusters composed of genes related to antibiotic scaffold synthesis, tailoring, regulation, and resistance. With the expansion of genome sequencing, a considerable number of antibiotic gene clusters has been isolated and characterized. The emerging genome engineering techniques make it possible towards more efficient engineering of antibiotics. In addition to genomic editing, multiple synthetic biology approaches have been developed for the exploration and improvement of antibiotic natural products. Here, we review the progress in the development of these genome editing techniques used to engineer new antibiotics, focusing on three aspects of genome engineering: direct cloning of large genomic fragments, genome engineering of gene clusters, and regulation of gene cluster expression. This review will not only summarize the current uses of genomic engineering techniques for cloning and assembly of antibiotic gene clusters or for altering antibiotic synthetic pathways but will also provide perspectives on the future directions of rebuilding biological systems for the design of novel antibiotics. © 2017 Wiley Periodicals, Inc.
Disease modeling in genetic kidney diseases: zebrafish.
Schenk, Heiko; Müller-Deile, Janina; Kinast, Mark; Schiffer, Mario
2017-07-01
Growing numbers of translational genomics studies are based on the highly efficient and versatile zebrafish (Danio rerio) vertebrate model. The increasing types of zebrafish models have improved our understanding of inherited kidney diseases, since they not only display pathophysiological changes but also give us the opportunity to develop and test novel treatment options in a high-throughput manner. New paradigms in inherited kidney diseases have been developed on the basis of the distinct genome conservation of approximately 70 % between zebrafish and humans in terms of existing gene orthologs. Several options are available to determine the functional role of a specific gene or gene sets. Permanent genome editing can be induced via complete gene knockout by using the CRISPR/Cas-system, among others, or via transient modification by using various morpholino techniques. Cross-species rescues succeeding knockdown techniques are employed to determine the functional significance of a target gene or a specific mutation. This article summarizes the current techniques and discusses their perspectives.
Dense and dynamic 3D selection for game-based virtual environments.
Cashion, Jeffrey; Wingrave, Chadwick; LaViola, Joseph J
2012-04-01
3D object selection is more demanding when, 1) objects densly surround the target object, 2) the target object is significantly occluded, and 3) when the target object is dynamically changing location. Most 3D selection techniques and guidelines were developed and tested on static or mostly sparse environments. In contrast, games tend to incorporate densly packed and dynamic objects as part of their typical interaction. With the increasing popularity of 3D selection in games using hand gestures or motion controllers, our current understanding of 3D selection needs revision. We present a study that compared four different selection techniques under five different scenarios based on varying object density and motion dynamics. We utilized two existing techniques, Raycasting and SQUAD, and developed two variations of them, Zoom and Expand, using iterative design. Our results indicate that while Raycasting and SQUAD both have weaknesses in terms of speed and accuracy in dense and dynamic environments, by making small modifications to them (i.e., flavoring), we can achieve significant performance increases.
Arnold, Robert W; Leman, Rachel E
2007-01-01
Kenneth Wright developed a technique for graded weakening of the superior oblique by increasing the effective length of this extraocular muscle's long tendon with a piece of silicone rubber retinal encircling band commonly used by eye surgery for retinal detachment repairs. In the absence of any specific retinal bands in our Children's Hospital, the following technique was developed affording a non-invasive ability to monitor, which was less intricate than the technique so well described by Demer. We substituted the "Mini Vessel Loop" (by Maaxxim Medical or Henley International). It is an elastic smooth silicone rubber cord that is radio-opaque, and can easily be seen on X-rays and CT scans. It is not an ophthalmologic medical device but it rather is designed to loop around and identify and gently retract blood vessels and nerves in any form of surgery where needed. We demonstrated success similar to that achieved by Wright in 43 patients using these radio-opaque, silicon Mini Vessel loops.
Janssen, K A; Sidoli, S; Garcia, B A
2017-01-01
Functional epigenetic regulation occurs by dynamic modification of chromatin, including genetic material (i.e., DNA methylation), histone proteins, and other nuclear proteins. Due to the highly complex nature of the histone code, mass spectrometry (MS) has become the leading technique in identification of single and combinatorial histone modifications. MS has now overcome antibody-based strategies due to its automation, high resolution, and accurate quantitation. Moreover, multiple approaches to analysis have been developed for global quantitation of posttranslational modifications (PTMs), including large-scale characterization of modification coexistence (middle-down and top-down proteomics), which is not currently possible with any other biochemical strategy. Recently, our group and others have simplified and increased the effectiveness of analyzing histone PTMs by improving multiple MS methods and data analysis tools. This review provides an overview of the major achievements in the analysis of histone PTMs using MS with a focus on the most recent improvements. We speculate that the workflow for histone analysis at its state of the art is highly reliable in terms of identification and quantitation accuracy, and it has the potential to become a routine method for systems biology thanks to the possibility of integrating histone MS results with genomics and proteomics datasets. © 2017 Elsevier Inc. All rights reserved.
Corrosion and surface modification on biocompatible metals: A review.
Asri, R I M; Harun, W S W; Samykano, M; Lah, N A C; Ghani, S A C; Tarlochan, F; Raza, M R
2017-08-01
Corrosion prevention in biomaterials has become crucial particularly to overcome inflammation and allergic reactions caused by the biomaterials' implants towards the human body. When these metal implants contacted with fluidic environments such as bloodstream and tissue of the body, most of them became mutually highly antagonistic and subsequently promotes corrosion. Biocompatible implants are typically made up of metallic, ceramic, composite and polymers. The present paper specifically focuses on biocompatible metals which favorably used as implants such as 316L stainless steel, cobalt-chromium-molybdenum, pure titanium and titanium-based alloys. This article also takes a close look at the effect of corrosion towards the implant and human body and the mechanism to improve it. Due to this corrosion delinquent, several surface modification techniques have been used to improve the corrosion behavior of biocompatible metals such as deposition of the coating, development of passivation oxide layer and ion beam surface modification. Apart from that, surface texturing methods such as plasma spraying, chemical etching, blasting, electropolishing, and laser treatment which used to improve corrosion behavior are also discussed in detail. Introduction of surface modifications to biocompatible metals is considered as a "best solution" so far to enhanced corrosion resistance performance; besides achieving superior biocompatibility and promoting osseointegration of biocompatible metals and alloys. Copyright © 2017 Elsevier B.V. All rights reserved.
ERIC Educational Resources Information Center
Renzulli, Joseph S.
This monograph addresses the role of gifted education in total school improvement by describing three service delivery components (the Total Talent Portfolio, Curriculum Modification Techniques, and Enrichment Learning and Teaching) and several organizational components of the Schoolwide Enrichment Model (SEM). The report describes how the SEM can…
NASA Technical Reports Server (NTRS)
Fricke, C. L.
1975-01-01
A solution to the problem of reflection from a semi-infinite atmosphere is presented, based upon Chandrasekhar's H-function method for linearly anisotropic phase functions. A modification to the Gauss quadrature formula which gives about the same accuracy with 10 points as the conventional Gauss quadrature does with 100 points was developed. A computer program achieving this solution is described and results are presented for several illustrative cases.
Xu, Rong; Kanezashi, Masakoto; Yoshioka, Tomohisa; Okuda, Tetsuji; Ohshita, Joji; Tsuru, Toshinori
2013-07-10
Bis(triethoxysilyl)ethylene (BTESEthy) was used as a novel precursor to develop a microporous organosilica membrane via the sol-gel technique. Water sorption measurements confirmed that ethenylene-bridged BTESEthy networks had a higher affinity for water than that of ethane-bridged organosilica materials. High permeance of CO2 with high CO2/N2 selectivity was explained relative to the strong CO2 adsorption on the network with π-bond electrons. The introduction of polarizable and rigid ethenylene bridges in the network structure led to improved water permeability and high NaCl rejection (>98.5%) in reverse osmosis (RO). Moreover, the aqueous ozone modification promoted significant improvement in the water permeability of the membrane. After 60 min of ozone exposure, the water permeability reached 1.1 × 10(-12) m(3)/(m(2) s Pa), which is close to that of a commercial seawater RO membrane. Meanwhile, molecular weight cutoff measurements indicated a gradual increase in the effective pore size with ozone modification, which may present new options for fine-tuning of membrane pore sizes.
Engineering of a DNA Polymerase for Direct m6 A Sequencing.
Aschenbrenner, Joos; Werner, Stephan; Marchand, Virginie; Adam, Martina; Motorin, Yuri; Helm, Mark; Marx, Andreas
2018-01-08
Methods for the detection of RNA modifications are of fundamental importance for advancing epitranscriptomics. N 6 -methyladenosine (m 6 A) is the most abundant RNA modification in mammalian mRNA and is involved in the regulation of gene expression. Current detection techniques are laborious and rely on antibody-based enrichment of m 6 A-containing RNA prior to sequencing, since m 6 A modifications are generally "erased" during reverse transcription (RT). To overcome the drawbacks associated with indirect detection, we aimed to generate novel DNA polymerase variants for direct m 6 A sequencing. Therefore, we developed a screen to evolve an RT-active KlenTaq DNA polymerase variant that sets a mark for N 6 -methylation. We identified a mutant that exhibits increased misincorporation opposite m 6 A compared to unmodified A. Application of the generated DNA polymerase in next-generation sequencing allowed the identification of m 6 A sites directly from the sequencing data of untreated RNA samples. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
Chemical methods for encoding and decoding of posttranslational modifications
Chuh, Kelly N.; Batt, Anna R.; Pratt, Matthew R.
2016-01-01
A large array of posttranslational modifications can dramatically change the properties of proteins and influence different aspects of their biological function such as enzymatic activity, binding interactions, and proteostasis. Despite the significant knowledge that has been gained about the function of posttranslational modifications using traditional biological techniques, the analysis of the site-specific effects of a particular modification, the identification of the full compliment of modified proteins in the proteome, and the detection of new types of modifications remains challenging. Over the years, chemical methods have contributed significantly in both of these areas of research. This review highlights several posttranslational modifications where chemistry-based approaches have made significant contributions to our ability to both prepare homogeneously modified proteins and identify and characterize particular modifications in complex biological settings. As the number and chemical diversity of documented posttranslational modifications continues to rise, we believe that chemical strategies will be essential to advance the field in years to come. PMID:26933738
Foustanos, Andreas; Panagiotopoulos, Konstantinos; Skouras, George
2011-02-01
The Pitanguy method of reduction mammaplasty has been shown to be an anatomically safe technique in the management of the ptotic breast. However, the technique, as first described, cannot be applied in gigantomastia or severe breast ptosis cases or cases of dense parenchyma of the breast. The senior surgeon suggested an intraoperative modification of the Pitanguy method of reduction mammaplasty to make it applicable for such cases. A retrospective study of 122 patients with severe breast ptosis (70), gigantomastia (45), or dense breast parenchyma (7) who underwent a modification of the Pitanguy method was performed. The current procedure involves all the operating steps of the superior pedicle technique as described by Pitanguy, from the marking technique to the keel resection of the breast. If the nipple-areola complex is elevated inadequately, the surgeon can use the senior surgeon's modification to elevate the complex to the desired height. This modification consists of dissecting the upper pole of the breast vertically to the fascia of the pectoralis major muscle and laterally to the nipple-areola complex. The medial flap is then advanced superiorly, rotated 90°, and sutured to point A, while the lateral flap is placed below the medial one. This maneuver maximizes elevation of the nipple-areola complex to the desired height. The mean change in nipple position was 14 cm (range = 10-16 cm). The mean weight reduction of each breast was 900 g (range = 700-1300 g). The follow-up included 119 patients and the follow-up period ranged from 1 to 3 years (mean follow-up = 2 years). Three patients were operated on less than 3 months ago and were not involved in this study. All patients gained natural shaped breasts and they were pleased with the results. Serious complications, including flap necrosis, were avoided since caution was used to preserve the internal mammary perforators while performing this method. This technique provides a versatile, well-vascularized pedicle that allows elevation of the nipple-areola complex at the desired height in cases of severe breast ptosis, gigantomastia, or dense breast parenchyma.
Radar studies of arctic ice and development of a real-time Arctic ice type identification system
NASA Technical Reports Server (NTRS)
Rouse, J. W., Jr.; Schell, J. A.; Permenter, J. A.
1973-01-01
Studies were conducted to develop a real-time Arctic ice type identification system. Data obtained by NASA Mission 126, conducted at Pt. Barrow, Alaska (Site 93) in April 1970 was analyzed in detail to more clearly define the major mechanisms at work affecting the radar energy illuminating a terrain cell of sea ice. General techniques for reduction of the scatterometer data to a form suitable for application of ice type decision criteria were investigated, and the electronic circuit requirements for implementation of these techniques were determined. Also, consideration of circuit requirements are extended to include the electronics necessary for analog programming of ice type decision algorithms. After completing the basic circuit designs a laboratory model was constructed and a preliminary evaluation performed. Several system modifications for improved performance are suggested. (Modified author abstract)
DeGere, Michael W; Grady, John F
2005-01-01
This study reports on 7 patients who underwent a new technique for Chopart amputation that includes ankle and subtalar arthrodesis using an intramedullary nail. This method affords rigid control to the rearfoot and appears to avoid the most common complications historically associated with Chopart amputations. All 6 surviving patients achieved successful outcomes within 1 year of their surgery. All are community ambulators who are able to walk short distances within the home without a prosthesis. One patient, who had undergone a previous vascular bypass, died in the early postoperative period after developing an infection that required an above-knee amputation. A second patient developed an infection that resolved with intravenous antibiotics. This new technique reintroduces the Chopart-level amputation as a valuable intermediate between the transmetatarsal and below-knee amputation levels.
Combination of diOlistic labeling with retrograde tract tracing and immunohistochemistry.
Neely, M Diana; Stanwood, Gregg D; Deutch, Ariel Y
2009-11-15
Neuronal staining techniques have played a crucial role in the analysis of neuronal function. Several different staining techniques have been developed to allow morphological analyses of neurons. DiOlistic labeling, in which beads are coated with a lipophilic dye and then ballistically ejected onto brain tissue, has recently been introduced as a useful and simple means to label neurons and glia in their entirety. Although diOlistic labeling provides detailed information on the morphology of neurons, combining this approach with other staining methods is a significant advance. We have developed protocols that result in high quality diOlistically- and retrogradely-labeled or diOlistically-immunohistochemically labeled neurons. These dual-label methods require modification of fixation parameters and the restricted use of detergents for tissue permeabilization, and are readily applicable to a wide range of tracers and antibodies.
Germline modification of domestic animals
Tang, L.; González, R.; Dobrinski, I.
2016-01-01
Genetically-modified domestic animal models are of increasing significance in biomedical research and agriculture. As authentic ES cells derived from domestic animals are not yet available, the prevailing approaches for engineering genetic modifications in those animals are pronuclear microinjection and somatic cell nuclear transfer (SCNT, also known as cloning). Both pronuclear microinjection and SCNT are inefficient, costly, and time-consuming. In animals produced by pronuclear microinjection, the exogenous transgene is usually inserted randomly into the genome, which results in highly variable expression patterns and levels in different founders. Therefore, significant efforts are required to generate and screen multiple founders to obtain animals with optimal transgene expression. For SCNT, specific genetic modifications (both gain-of-function and loss-of-function) can be engineered and carefully selected in the somatic cell nucleus before nuclear transfer. SCNT has been used to generate a variety of genetically modified animals such as goats, pigs, sheep and cattle; however, animals resulting from SCNT frequently suffer from developmental abnormalities associated with incomplete nuclear reprogramming. Other strategies to generate genetically-modified animals rely on the use of the spermatozoon as a natural vector to introduce genetic material into the female gamete. This sperm mediated DNA transfer (SMGT) combined with intracytoplasmatic sperm injection (ICSI) has relatively high efficiency and allows the insertion of large DNA fragments, which, in turn, enhance proper gene expression. An approach currently being developed to complement SCNT for producing genetically modified animals is germ cell transplantation using genetically modified male germline stem cells (GSCs). This approach relies on the ability of GSCs that are genetically modified in vitro to colonize the recipient testis and produce donor derived sperm upon transplantation. As the genetic change is introduced into the male germ line just before the onset of spermatogenesis, the time required for the production of genetically modified sperm is significantly shorter using germ cell transplantation compared to cloning or embryonic stem (ES) cell based technology. Moreover, the GSC-mediated germline modification circumvents problems associated with embryo manipulation and nuclear reprogramming. Currently, engineering targeted mutations in domestic animals using GSCs remains a challenge as GSCs from those animals are difficult to maintain in vitro for an extended period of time. Recent advances in genome editing techniques such as Zinc-Finger Nucleases (ZFNs), Transcription Activator-like Effector Nucleases (TALENs) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs) greatly enhance the efficiency of engineering targeted genetic change in domestic animals as demonstrated by the generation of several gene knock-out pig and cattle models using those techniques. The potential of GSC-mediated germline modification in making targeted genetic modifications in domestic animal models will be maximized if those genome editing techniques can be applied in GSCs. PMID:27390591
von Maltzahn, Nadine Freifrau; Holstermann, Jan; Kohorst, Philipp
2016-08-01
The adhesive connection between titanium base and zirconia coping of two-part abutments may be responsible for the failure rate. A high mechanical stability between both components is essential for the long-term success. The aim of the present in-vitro study was to evaluate the influence of different surface modification techniques and resin-based luting agents on the retention forces between titanium and zirconia components in two-part implant abutments. A total of 120 abutments with a titanium base bonded to a zirconia coping were investigated. Two different resin-based luting agents (Panavia F 2.0 and RelyX Unicem) and six different surface modifications were used to fix these components, resulting in 12 test groups (n = 10). The surface of the test specimens was mechanically pretreated with aluminium oxide blasting in combination with application of two surface activating primers (Alloy Primer, Clearfil Ceramic Primer) or a tribological conditioning (Rocatec), respectively. All specimens underwent 10,000 thermal cycles between 5°C and 55°C in a moist environment. A pull-off test was then conducted to determine retention forces between the titanium and zirconia components, and statistical analysis was performed (two-way anova). Finally, fracture surfaces were analyzed by light and scanning electron microscopy. No significant differences were found between Panavia F 2.0 and RelyX Unicem. However, the retention forces were significantly influenced by the surface modification technique used (p < 0.001). For both luting agents, the highest retention forces were found when adhesion surfaces of both the titanium bases and the zirconia copings were pretreated with aluminium oxide blasting, and with the application of Clearfil Ceramic Primer. Surface modification techniques crucially influence the retention forces between titanium and zirconia components in two-part implant abutments. All adhesion surfaces should be pretreated by sandblasting. Moreover, a phosphate-based primer serves to enhance long-term retention of the components. © 2015 Wiley Periodicals, Inc.
A simple in vitro culture system for tracheal cartilage development.
Park, Jinhyung; Zhang, Jennifer J R; Choi, Ruth; Trinh, Irene; Kim, Peter C W
2010-02-01
Semi-circular tracheal cartilage is a critical determinant of maintaining architectural integrity of the respiratory airway. The current effort to understand the morphogenesis of tracheal cartilage is challenged by the lack of appropriate model systems. Here we report an in vitro tracheal cartilage system using embryonic tracheal–lung explants to recapitulate in vivo tracheal cartilage developmental processes. With modifications of a current lung culture protocol, we report a consistent in vitro technique of culturing tracheal cartilage from primitive mouse embryonic foregut for the first time. This tracheal culture system not only induces the formation of tracheal cartilage from the mouse embryonic foregut but also allows for the proper patterning of the developed tracheal cartilage. Furthermore, we show that this culture technique can be applied to culturing other types of cartilage in vertebrae, limbs, and ribs. We believe that this novel application of our in vitro culture system will facilitate the manipulation of cartilage development under various conditions and thus enabling us to advance our current limited knowledge on cartilage biology and development.
Recent Advances in Techniques for Starch Esters and the Applications: A Review
Hong, Jing; Zeng, Xin-An; Brennan, Charles S.; Brennan, Margaret; Han, Zhong
2016-01-01
Esterification is one of the most important methods to alter the structure of starch granules and improve its applications. Conventionally, starch esters are prepared by conventional or dual modification techniques, which have the disadvantages of being expensive, have regent overdoses, and are time-consuming. In addition, the degree of substitution (DS) is often considered as the primary factor in view of its contribution to estimate substituted groups of starch esters. In order to improve the detection accuracy and production efficiency, different detection techniques, including titration, nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis/infrared spectroscopy (TGA/IR) and headspace gas chromatography (HS-GC), have been developed for DS. This paper gives a comprehensive overview on the recent advances in DS analysis and starch esterification techniques. Additionally, the advantages, limitations, some perspectives on future trends of these techniques and the applications of their derivatives in the food industry are also presented. PMID:28231145
Exploitation of molecular profiling techniques for GM food safety assessment.
Kuiper, Harry A; Kok, Esther J; Engel, Karl-Heinz
2003-04-01
Several strategies have been developed to identify unintended alterations in the composition of genetically modified (GM) food crops that may occur as a result of the genetic modification process. These include comparative chemical analysis of single compounds in GM food crops and their conventional non-GM counterparts, and profiling methods such as DNA/RNA microarray technologies, proteomics and metabolite profiling. The potential of profiling methods is obvious, but further exploration of specificity, sensitivity and validation is needed. Moreover, the successful application of profiling techniques to the safety evaluation of GM foods will require linked databases to be built that contain information on variations in profiles associated with differences in developmental stages and environmental conditions.
Sacral nerve stimulation for neuromodulation of the lower urinary tract.
Hubsher, Chad P; Jansen, Robert; Riggs, Dale R; Jackson, Barbara J; Zaslau, Stanley
2012-10-01
Sacral neuromodulation (SNM) has become a standard treatment option for patients suffering from urinary urge incontinence, urgency-frequency, and/or nonobstructive urinary retention refractory to conservative and pharmacologic treatment. Since its initial development, the manufacturer of InterStim therapy (Medtronic, Inc., Minneapolis, MN, USA), has introduced technical modifications, while surgeons and researchers have adapted and published various innovations and alterations of the implantation technique. In this article, we feature our SNM technique including patient selection, comprehensive dialogue/evaluation, procedure details, and appropriate follow up. Although there is often great variability in patients with lower urinary tract dysfunction, we maintain that great success can be achieved with a systematic and methodical approach to SNM.
NASA Technical Reports Server (NTRS)
Poulain, Pierre-Marie; Luther, Douglas S.; Patzert, William C.
1992-01-01
Two techniques were developed for estimating statistics of inertial oscillations from satellite-tracked drifters that overcome the difficulties inherent in estimating such statistics from data dependent upon space coordinates that are a function of time. Application of these techniques to tropical surface drifter data collected during the NORPAX, EPOCS, and TOGA programs reveals a latitude-dependent, statistically significant 'blue shift' of inertial wave frequency. The latitudinal dependence of the blue shift is similar to predictions based on 'global' internal-wave spectral models, with a superposition of frequency shifting due to modification of the effective local inertial frequency by the presence of strongly sheared zonal mean currents within 12 deg of the equator.
A Review of Gene Knockout Strategies for Microbial Cells.
Tang, Phooi Wah; Chua, Pooi San; Chong, Shiue Kee; Mohamad, Mohd Saberi; Choon, Yee Wen; Deris, Safaai; Omatu, Sigeru; Corchado, Juan Manuel; Chan, Weng Howe; Rahim, Raha Abdul
2015-01-01
Predicting the effects of genetic modification is difficult due to the complexity of metabolic net- works. Various gene knockout strategies have been utilised to deactivate specific genes in order to determine the effects of these genes on the function of microbes. Deactivation of genes can lead to deletion of certain proteins and functions. Through these strategies, the associated function of a deleted gene can be identified from the metabolic networks. The main aim of this paper is to review the available techniques in gene knockout strategies for microbial cells. The review is done in terms of their methodology, recent applications in microbial cells. In addition, the advantages and disadvantages of the techniques are compared and discuss and the related patents are also listed as well. Traditionally, gene knockout is done through wet lab (in vivo) techniques, which were conducted through laboratory experiments. However, these techniques are costly and time consuming. Hence, various dry lab (in silico) techniques, where are conducted using computational approaches, have been developed to surmount these problem. The development of numerous techniques for gene knockout in microbial cells has brought many advancements in the study of gene functions. Based on the literatures, we found that the gene knockout strategies currently used are sensibly implemented with regard to their benefits.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chang, E.L.; Calvert, J.M.; Koloski, T.
1997-02-01
We report on the results of a project using surface characterization and novel surface-modification techniques to address the issues of developing a minimally fouling ceramic membrane filter. We have studied the physical characteristics of a synthetic bilge water mixture, examined the surfaces of the ceramic filters for evidence of fouling, and identified several surface modifications that, under laboratory conditions, work well in prevention of foulants. These surfaces include hydrophobic as well as polar coatings. For the bilge water, it was discovered that detergent, at certain concentrations, may be useful in separating and coalescing oil droplets from the bilge water. Basedmore » on the results of the studies, several strategies for optimizing the removal of oil from water are suggested.« less
The Interaction of Bacteria with Engineered Nanostructured Polymeric Materials: A Review
Armentano, Ilaria; Arciola, Carla Renata; Fortunati, Elena; Ferrari, Davide; Mattioli, Samantha; Amoroso, Concetta Floriana; Rizzo, Jessica; Kenny, Jose M.; Imbriani, Marcello; Visai, Livia
2014-01-01
Bacterial infections are a leading cause of morbidity and mortality worldwide. In spite of great advances in biomaterials research and development, a significant proportion of medical devices undergo bacterial colonization and become the target of an implant-related infection. We present a review of the two major classes of antibacterial nanostructured materials: polymeric nanocomposites and surface-engineered materials. The paper describes antibacterial effects due to the induced material properties, along with the principles of bacterial adhesion and the biofilm formation process. Methods for antimicrobial modifications of polymers using a nanocomposite approach as well as surface modification procedures are surveyed and discussed, followed by a concise examination of techniques used in estimating bacteria/material interactions. Finally, we present an outline of future sceneries and perspectives on antibacterial applications of nanostructured materials to resist or counteract implant infections. PMID:25025086
Flow-induced Vibration of SSME Main Injector Liquid-oxygen Posts
NASA Technical Reports Server (NTRS)
Chen, S. S.; Jendrzejczyk, J. A.; Wambsganss, M. W.
1985-01-01
The liquid-oxygen (LOX) posts are exposed to hot hydrogen flowing over the tubes on its way to the combustion chamber. Fatigue cracking of some LOX posts was observed after test firing of the SSMEs. A current design modification consists of attaching impingement shields to the LOX posts in the outer row. The modification improved the vibration/fatigue problem of the LOX posts, but resulted in an increased pressure drop that ultimately shortened the life expectancy of other components. A fundamental study of vibration of the LOX posts was initiated to understand the flow-induced vibration problem and to develop techniques to avoid detrimental vibrational effects with the overall objective of improving engine life. This effort, including an assessment of the problem, scoping calculation and experiment, and a work plan for an integrated theoretical/experimental study of the problem is summarized.
NASA Technical Reports Server (NTRS)
Jordan, F. L., Jr.; Mclemore, H. C.; Bragg, M. B.
1978-01-01
The current status of aerial applications technology research at the Langley's Vortex Research Facility and Full-Scale Wind Tunnel is reviewed. Efforts have been directed mainly toward developing and validating the required experimental and theoretical research tools. A capability to simulate aerial dispersal of materials from agricultural airplanes with small-scale airplane models, numerical methods, and dynamically scaled test particles was demonstrated. Tests on wake modification concepts have proved the feasibility of tailoring wake properties aerodynamically to produce favorable changes in deposition and to provide drift control. An aerodynamic evaluation of the Thrush Commander 800 agricultural airplane with various dispersal systems installed is described. A number of modifications intended to provide system improvement to both airplane and dispersal system are examined, and a technique for documenting near-field spray characteristics is evaluated.
Bioorthogonal Chemistry: Fishing for Selectivity in a Sea of Functionality
Sletten, Ellen M.
2010-01-01
The study of biomolecules in their native environments is a challenging task because of the vast complexity of cellular systems. Technologies developed in the last few years for the selective modification of biological species in living systems have yielded new insights into cellular processes. Key to these new techniques are bioorthogonal chemical reactions, whose components must react rapidly and selectively with each other under physiological conditions in the presence of the plethora of functionality necessary to sustain life. Herein we describe the bioorthogonal chemical reactions developed to date and how they can be used to study biomolecules. PMID:19714693
Bioorthogonal chemistry: fishing for selectivity in a sea of functionality.
Sletten, Ellen M; Bertozzi, Carolyn R
2009-01-01
The study of biomolecules in their native environments is a challenging task because of the vast complexity of cellular systems. Technologies developed in the last few years for the selective modification of biological species in living systems have yielded new insights into cellular processes. Key to these new techniques are bioorthogonal chemical reactions, whose components must react rapidly and selectively with each other under physiological conditions in the presence of the plethora of functionality necessary to sustain life. Herein we describe the bioorthogonal chemical reactions developed to date and how they can be used to study biomolecules.
Aerospace Environmental Technology Conference
NASA Technical Reports Server (NTRS)
Whitaker, A. F. (Editor)
1995-01-01
The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The Executive Summary of this Conference is published as NASA CP-3297.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kusworo, T. D., E-mail: tdkusworo@che.undip.ac.id; Widayat,; Pradini, A. W.
2015-12-29
Membrane technology is an alternative of water treatment based on filtration that is being developed. Surface Modification using heat treatment has been investigated to improve the performance of ultra thin PES-Zeolite nanocomposite membrane for produced water treatment from Pertamina Balongan. Two types of membranes with surface modification and without modification were prepared to study the effect of surface modification on its permeation properties. Asymmetric ultra thin PES-Zeolite nanocomposite membrane for produced water treatment was casted using the dry/wet phase inversion technique from dope solutions containing polyethersulfone, N-methyl-2-pyrrolidone (NMP) as a solvent and zeolite as a filler. Experimental results showed thatmore » the heat treatment at near glass transition temperature was increase the rejection of COD, Turbidity and ion Ca{sup 2+}. The better adherence of zeolite particles in the polymer matrix combined with formation of charge transfer complexes (CTCs) and cross-linking might be the main factors to enhance the percent of rejection. Field emission scanning electron microscopy (FESEM) micrographs showed that the selective layer and the substructure of PES-zeolite membrane became denser and more compact after the heat treatment. The FESEM micrographs also showed that the heat treatment was increased the adherence of zeolite particle and polymer. Membranes treated at 180 °C for 15 seconds indicated increase the rejection and small decrease in flux for produced water treatment.« less
Sadeghian, Tanaz; Tavaf, Zohreh; Oryan, Ahmad; Shokouhi, Raheleh; Pourpak, Zahra; Moosavi-Movahedi, Ali Akbar; Yousefi, Reza
2018-01-01
Mastitis, an inflammatory reaction frequently develops in response to intra-mammary bacterial infection, may induce the generation of peroxynitrite (PON) which is a highly potent reactive oxygen and nitrogen species. Caseins as the intrinsically unfolded proteins seem feasible substrates to react with PON. Therefore, in the current study, structural and functional aspects of both β-casein (β-CN) and whole casein fraction (WCF) were evaluated after PON modification, using a variety of techniques. Modification of the bovine caseins with PON results in an important enhancement in the carbonyl, nitrotryptophan, nitrotyrosine and dityrosine content of these proteins. The results of fluorescence and far UV-CD assessments suggested significant structural alteration of caseins upon PON-modification. The chaperone-like activity of β-casein was significantly altered after PON modification. The results of scanning electron microscopy suggest that bovine caseins display unique morphological features after treatment with PON. Also, the PON-modified caseins preserved their allergenicity profile and displayed partial resistance against digestion by the pancreatic proteases. Ascorbic acid, an important antioxidant component of milk, was also capable to significantly prevent the PON-induced structural damages in bovine milk caseins. In conclusion, our results suggest that PON may have significant role in the structural and functional alteration of milk caseins. Also, the PON-induced structural damaging effects of caseins might be effectively prevented by a sufficient level of milk antioxidant components particularly by ascorbic acid. Copyright © 2017 Elsevier B.V. All rights reserved.
From Ringmaster to Conductor: 10 Simple Techniques Can Turn an Unruly Class into a Productive One
ERIC Educational Resources Information Center
Kraft, Matthew A.
2010-01-01
Challenging classrooms can overwhelm a teacher. However, by using effective classroom management and behavior modification techniques, teachers can change challenging classrooms into productive ones. Classroom management techniques include using a relevant curriculum, establishing nonnegotiable rules, ensuring that students know what behavior is…
Schwartz, Lawrence H; Seymour, Lesley; Litière, Saskia; Ford, Robert; Gwyther, Stephen; Mandrekar, Sumithra; Shankar, Lalitha; Bogaerts, Jan; Chen, Alice; Dancey, Janet; Hayes, Wendy; Hodi, F Stephen; Hoekstra, Otto S; Huang, Erich P; Lin, Nancy; Liu, Yan; Therasse, Patrick; Wolchok, Jedd D; de Vries, Elisabeth
2016-07-01
Radiologic imaging of disease sites plays a pivotal role in the management of patients with cancer. Response Evaluation Criteria in Solid Tumours (RECIST), introduced in 2000, and modified in 2009, has become the de facto standard for assessment of response in solid tumours in patients on clinical trials. The RECIST Working Group considers the ability of the global oncology community to implement and adopt updates to RECIST in a timely manner to be critical. Updates to RECIST must be tested, validated and implemented in a standardised, methodical manner in response to therapeutic and imaging technology advances as well as experience gained by users. This was the case with the development of RECIST 1.1, where an expanded data warehouse was developed to test and validate modifications. Similar initiatives are ongoing, testing RECIST in the evaluation of response to non-cytotoxic agents, immunotherapies, as well as in specific diseases. The RECIST Working Group has previously outlined the level of evidence considered necessary to formally and fully validate new imaging markers as an appropriate end-point for clinical trials. Achieving the optimal level of evidence desired is a difficult feat for phase III trials; this involves a meta-analysis of multiple prospective, randomised multicentre clinical trials. The rationale for modifications should also be considered; the modifications may be proposed to improve surrogacy, to provide a more mechanistic imaging technique, or be designed to improve reproducibility of the imaging biomarker. Here, we present the commonly described modifications of RECIST, each of which is associated with different levels of evidence and validation. Copyright © 2016. Published by Elsevier Ltd.
Channeling techniques to study strains and defects in heterostructures and multi quantum wells
NASA Astrophysics Data System (ADS)
Pathak, A. P.; Dhamodaran, S.; Sathish, N.
2005-08-01
The importance and advantages of heterostructures and Quantum Wells (QWs) in device technology has made research challenging due to lack of direct techniques for their characterization. Particularly the characterization of strain and defects at the interfaces has become important due to their dominance in the electrical and optical properties of materials and devices. RBSiC has been used to study variety of defects in single crystalline materials, for nearly four decades now. Channeling based experiments play a crucial role in giving depth information of strain and defects. Ion beams are used for both material characterizations as well as for modifications. Hence it is also possible to monitor the modifications online, which are discussed in detail. In the present work, Swift Heavy Ion (SHI) modification of III-V semiconductor heterostnictures and MQWs and the results of subsequent strain measurements by RBSiC in initially strained as well as lattice matched systems are discussed. We find that the compressive strain decreases due to SHI irradiation and a tensile strain is induced in an initially lattice matched system. The incident ion fluence dependence of strain modifications in the heterostructures will also be discussed. The use of high energy channeling for better sensitivity of strain measurements in low mismatch materials will be discussed in detail. Wherever possible, a comparison of results with those obtained by other techniques like HRXRD is given.
Modification of the Nominal Group Activity for On-Line Instruction.
ERIC Educational Resources Information Center
Maulding, Wanda S.
This paper discusses how the Nominal Group Technique (NGT) can be adapted for use in online instruction. The four basic stages of the NGT (listing, recording, collating, and prioritizing) are described, and modifications for online delivery are detailed, including: (1) the instructor posts the Socratic question or problem to be posed; (2) students…
NASA Technical Reports Server (NTRS)
Everhart, J. L.
1983-01-01
A program called FLEXWAL for calculating wall modifications for solid, adaptive-wall wind tunnels is presented. The method used is the iterative technique of NASA TP-2081 and is applicable to subsonic and transonic test conditions. The program usage, program listing, and a sample case are given.
Black Psychologists Discuss Behavior Modification.
ERIC Educational Resources Information Center
Bardo, Harold R.; And Others
The primary purpose of this paper is to discuss reasons why blacks should be concerned and actively involved with practices in behavior modification. The concern is that as these techniques are refined it becomes more important to be sure blacks should be involved at all levels of the application of these procedures when other blacks are subjects…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lips, H.I.; Gotterba, J.A.; Lim, K.J.
1981-07-01
The report gives results of an environmental assessment of combustion modification techniques for stationary internal combustion engines, with respect to NOx control reduction effectiveness, operational impact, thermal efficiency impact, capital and annualized operating costs, and effects on emissions of pollutants other than NOx.
Microscale surface modifications for heat transfer enhancement.
Bostanci, Huseyin; Singh, Virendra; Kizito, John P; Rini, Daniel P; Seal, Sudipta; Chow, Louis C
2013-10-09
In this experimental study, two surface modification techniques were investigated for their effect on heat transfer enhancement. One of the methods employed the particle (grit) blasting to create microscale indentations, while the other used plasma spray coating to create microscale protrusions on Al 6061 (aluminum alloy 6061) samples. The test surfaces were characterized using scanning electron microscopy (SEM) and confocal scanning laser microscopy. Because of the surface modifications, the actual surface area was increased up to 2.8× compared to the projected base area, and the arithmetic mean roughness value (Ra) was determined to vary from 0.3 μm for the reference smooth surface to 19.5 μm for the modified surfaces. Selected samples with modified surfaces along with the reference smooth surface were then evaluated for their heat transfer performance in spray cooling tests. The cooling system had vapor-atomizing nozzles and used anhydrous ammonia as the coolant in order to achieve heat fluxes up to 500 W/cm(2) representing a thermal management setting for high power systems. Experimental results showed that the microscale surface modifications enhanced heat transfer coefficients up to 76% at 500 W/cm(2) compared to the smooth surface and demonstrated the benefits of these practical surface modification techniques to enhance two-phase heat transfer process.
Modification of aniline containing proteins using an oxidative coupling strategy.
Hooker, Jacob M; Esser-Kahn, Aaron P; Francis, Matthew B
2006-12-13
A new bioconjugation reaction has been developed based on the chemoselective modification of anilines through an oxidative coupling pathway. Aryl amines were installed on the surface of protein substrates through lysine acylation reactions or through the use of native chemical ligation techniques. Upon exposure to NaIO4 in aqueous buffer, the anilines coupled rapidly to the aromatic rings of N,N-dialkyl-N'-acyl-p-phenylenediamines. The identities of the reaction products were confirmed using ESI-MS and through comparison to small molecule analogs. Control experiments indicated that none of the native amino acids participated in the reaction. The resulting bioconjugates were found to be stable toward hydrolysis from pH 4 to pH 11 and in the presence of many commonly used oxidants, reductants, and nucleophiles. A fluorescent phenylenediamine reagent was synthesized for the selective detection of aniline labeled proteins in mixtures, and the reaction was used to append the C-terminus of the green fluorescent protein with a single PEG chain. When combined with techniques for the incorporation of unnatural amino acids into proteins, this bioorthogonal coupling method should prove useful for a number of applications requiring a high degree of labeling specificity.
Ye, Sang-Ho; Jang, Yong-Seok; Yun, Yeo-Heung; Shankarraman, Venkat; Woolley, Joshua R; Hong, Yi; Gamble, Lara J; Ishihara, Kazuhiko; Wagner, William R
2013-07-02
Siloxane functionalized phosphorylcholine (PC) or sulfobetaine (SB) macromolecules (PCSSi or SBSSi) were synthesized to act as surface modifying agents for degradable metallic surfaces to improve acute blood compatibility and slow initial corrosion rates. The macromolecules were synthesized using a thiol-ene radical photopolymerization technique and then utilized to modify magnesium (Mg) alloy (AZ31) surfaces via an anhydrous phase deposition of the silane functional groups. X-ray photoelectron spectroscopy surface analysis results indicated successful surface modification based on increased nitrogen and phosphorus or sulfur composition on the modified surfaces relative to unmodified AZ31. In vitro acute thrombogenicity assessment after ovine blood contact with the PCSSi and SBSSi modified surfaces showed a significant decrease in platelet deposition and bulk phase platelet activation compared with the control alloy surfaces. Potentiodynamic polarization and electrochemical impedance spectroscopy data obtained from electrochemical corrosion testing demonstrated increased corrosion resistance for PCSSi- and SBSSi-modified AZ31 versus unmodified surfaces. The developed coating technique using PCSSi or SBSSi showed promise in acutely reducing both the corrosion and thrombotic processes, which would be attractive for application to blood contacting devices, such as vascular stents, made from degradable Mg alloys.
Lin, Donghai; Tang, Thompson; Jed Harrison, D; Lee, William E; Jemere, Abebaw B
2015-06-15
We report on the development of a regenerable sensitive immunosensor based on electrochemical impedance spectroscopy for the detection of type 5 adenovirus. The multi-layered immunosensor fabrication involved successive modification steps on gold electrodes: (i) modification with self-assembled layer of 1,6-hexanedithiol to which gold nanoparticles were attached via the distal thiol groups, (ii) formation of self-assembled monolayer of 11-mercaptoundecanoic acid onto the gold nanoparticles, (iii) covalent immobilization of monoclonal anti-adenovirus 5 antibody, with EDC/NHS coupling reaction on the nanoparticles, completing the immunosensor. The immunosensor displayed a very good detection limit of 30 virus particles/ml and a wide linear dynamic range of 10(5). An electrochemical reductive desorption technique was employed to completely desorb the components of the immunosensor surface, then re-assemble the sensing layer and reuse the sensor. On a single electrode, the multi-layered immunosensor could be assembled and disassembled at least 30 times with 87% of the original signal intact. The changes of electrode behavior after each assembly and desorption processes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy techniques. Copyright © 2014 Elsevier B.V. All rights reserved.
NASA Astrophysics Data System (ADS)
Krimi, Abdelkader; Rezoug, Mehdi; Khelladi, Sofiane; Nogueira, Xesús; Deligant, Michael; Ramírez, Luis
2018-04-01
In this work, a consistent Smoothed Particle Hydrodynamics (SPH) model to deal with interfacial multiphase fluid flows simulation is proposed. A modification to the Continuum Stress Surface formulation (CSS) [1] to enhance the stability near the fluid interface is developed in the framework of the SPH method. A non-conservative first-order consistency operator is used to compute the divergence of stress surface tensor. This formulation benefits of all the advantages of the one proposed by Adami et al. [2] and, in addition, it can be applied to more than two phases fluid flow simulations. Moreover, the generalized wall boundary conditions [3] are modified in order to be well adapted to multiphase fluid flows with different density and viscosity. In order to allow the application of this technique to wall-bounded multiphase flows, a modification of generalized wall boundary conditions is presented here for using the SPH method. In this work we also present a particle redistribution strategy as an extension of the damping technique presented in [3] to smooth the initial transient phase of gravitational multiphase fluid flow simulations. Several computational tests are investigated to show the accuracy, convergence and applicability of the proposed SPH interfacial multiphase model.
Optimising Laser Tattoo Removal
Sardana, Kabir; Ranjan, Rashmi; Ghunawat, Sneha
2015-01-01
Lasers are the standard modality for tattoo removal. Though there are various factors that determine the results, we have divided them into three logical headings, laser dependant factors such as type of laser and beam modifications, tattoo dependent factors like size and depth, colour of pigment and lastly host dependent factors, which includes primarily the presence of a robust immune response. Modifications in the existing techniques may help in better clinical outcome with minimal risk of complications. This article provides an insight into some of these techniques along with a detailed account of the factors involved in tattoo removal. PMID:25949018
An analysis of thermal response factors and how to reduce their computational time requirement
NASA Technical Reports Server (NTRS)
Wiese, M. R.
1982-01-01
Te RESFAC2 version of the Thermal Response Factor Program (RESFAC) is the result of numerous modifications and additions to the original RESFAC. These modifications and additions have significantly reduced the program's computational time requirement. As a result of this work, the program is more efficient and its code is both readable and understandable. This report describes what a thermal response factor is; analyzes the original matrix algebra calculations and root finding techniques; presents a new root finding technique and streamlined matrix algebra; supplies ten validation cases and their results.
New Methodologies for Generation of Multigroup Cross Sections for Shielding Applications
NASA Astrophysics Data System (ADS)
Arzu Alpan, F.; Haghighat, Alireza
2003-06-01
Coupled neutron and gamma multigroup (broad-group) libraries used for Light Water Reactor shielding and dosimetry commonly include 47-neutron and 20-gamma groups. These libraries are derived from the 199-neutron, 42-gamma fine-group VITAMIN-B6 library. In this paper, we introduce modifications to the generation procedure of the broad-group libraries. Among these modifications, we show that the fine-group structure and collapsing technique have the largest impact. We demonstrate that a more refined fine-group library and the bi-linear adjoint weighting collapsing technique can improve the accuracy of transport calculation results.
Close Encounters - Probing Proximal Proteins in Live or Fixed Cells.
Lönn, Peter; Landegren, Ulf
2017-07-01
The well-oiled machinery of the cellular proteome operates via variable expression, modifications, and interactions of proteins, relaying genomic and transcriptomic information to coordinate cellular functions. In recent years, a number of techniques have emerged that serve to identify sets of proteins acting in close proximity in the course of orchestrating cellular activities. These proximity-dependent assays, including BiFC, BioID, APEX, FRET, and isPLA, have opened up new avenues to examine protein interactions in live or fixed cells. We review herein the current status of proximity-dependent in situ techniques. We compare the advantages and limitations of the methods, underlining recent progress and the growing importance of these techniques in basic research, and we discuss their potential as tools for drug development and diagnostics. Copyright © 2017 Elsevier Ltd. All rights reserved.
Clustering: An Interactive Technique to Enhance Learning in Biology.
ERIC Educational Resources Information Center
Ambron, Joanna
1988-01-01
Explains an interdisciplinary approach to biology and writing which increases students' mastery of vocabulary, scientific concepts, creativity, and expression. Describes modifications of the clustering technique used to summarize lectures, integrate reading and understand textbook material. (RT)
Measurement, testing, and safety technology: A compilation
NASA Technical Reports Server (NTRS)
1974-01-01
Methods and techniques in the related areas of measurement, testing, and safety are presented. Measuring techniques and devices and testing methods and devices are described. Articles on equipment modifications or procedures are included. Patent information is presented.
Deep patch technique for landslide repair. Final report
DOE Office of Scientific and Technical Information (OSTI.GOV)
Helwany, B.M.
1994-10-01
The report describes the laboratory testing of the `USFS deep patch` technique and a CTI modification of this technique for repairing landslides with geosynthetic reinforcement. The technique involves replacing sections of roadway lost due to landslides on top of a geosynthetically-reinforced embankment. The CTI modification involves replacing the reinforced slope with a geosynthetically-reinforced retaining wall with a truncated base. Both techniques rely on the cantilevering ability of the reinforced mass to limit the load on the foundation with a high slide potential. The tests with road base showed that (1) both the USFS and CTI repair reduced effectively the adversemore » effects of local landsliding on the highway pavement by preventing crack propagation; (2) the USFS repair increased the stability of the repaired slope, which was in progressive failure, by reducing the stresses exerted on it; and (3) the CTI repair produced substantially greater stresses on its foundation due to the truncated base of the reinforced mass.« less
Noe, Gregory B.
2011-01-01
A modification of the resin-core method was developed and tested for measuring in situ soil N and P net mineralization rates in wetland soils where temporal variation in bidirectional vertical water movement and saturation can complicate measurement. The modified design includes three mixed-bed ion-exchange resin bags located above and three resin bags located below soil incubating inside a core tube. The two inner resin bags adjacent to the soil capture NH4+, NO3-, and soluble reactive phosphorus (SRP) transported out of the soil during incubation; the two outer resin bags remove inorganic nutrients transported into the modified resin core; and the two middle resin bags serve as quality-control checks on the function of the inner and outer resin bags. Modified resin cores were incubated monthly for a year along the hydrogeomorphic gradient through a floodplain wetland. Only small amounts of NH4+, NO3-, and SRP were found in the two middle resin bags, indicating that the modified resin-core design was effective. Soil moisture and pH inside the modified resin cores typically tracked changes in the surrounding soil abiotic environment. In contrast, use of the closed polyethylene bag method provided substantially different net P and N mineralization rates than modified resin cores and did not track changes in soil moisture or pH. Net ammonification, nitrifi cation, N mineralization, and P mineralization rates measured using modified resin cores varied through space and time associated with hydrologic, geomorphic, and climatic gradients in the floodplain wetland. The modified resin-core technique successfully characterized spatiotemporal variation of net mineralization fluxes in situ and is a viable technique for assessing soil nutrient availability and developing ecosystem budgets.
Recent progress in plasma-assisted synthesis and modification of 2D materials
NASA Astrophysics Data System (ADS)
Han, Zhao Jun; Murdock, Adrian T.; Seo, Dong Han; Bendavid, Avi
2018-07-01
Plasma represents an important technique for both the synthesis and modification of two-dimensional (2D) materials, owing to the unique plasma-material interactions which can enable effective energy transfer at the nanoscale. Non-equilibrium and non-thermal plasma techniques have been widely applied on various 2D materials, including graphene, silicene, germanene, phosphorene, hexagonal boron nitride (h-BN), and transition metal dichalcogenides such as MoS2 and WS2. Here, we review the recent progress in plasma-assisted synthesis and modification (e.g. functionalisation, doping and etching) of 2D materials and discuss the potential applications of this unique branch of 2D materials. Challenges and future research opportunities in the relevant research field are also discussed. The primary aim of this Review is to provide a better understanding of the plasma-assisted processes and to promote the utilization of 2D materials for advanced electronic, optoelectronic, sensing and energy storage applications.
Damage-free polymer surface modification employing inward-type plasma
NASA Astrophysics Data System (ADS)
Kanou, Ryo; Suga, Hiroshi; Utsumi, Hideyuki; Takahashi, Satoshi; Shirayama, Yuya; Watanabe, Norimichi; Petit, Stèphane; Shimizu, Tetsuo
2017-08-01
Inward-type plasmas, which spread upstream against the gas flow in the capillary tube where the gas is discharged, can react with samples placed near the entrance of such a capillary tube. In this study, surface modification of polymer surfaces is conducted using inward plasma. The modification is also done by conventional microplasma jet, and the modified surfaces with two plasma techniques are characterized by contact angle measurement, X-ray photoemission spectroscopy (XPS), and atomic force microscopy (AFM). Although inward-plasma-treated surfaces are less hydrophilic than conventional plasma-treated ones, they are still sufficiently hydrophilic for surface coatings. In addition, it turns out that the polymer surfaces irradiated with the inward plasma yield much smoother surfaces than those treated with the conventional plasma jet. Thus, the inward plasma treatment is a viable technique when the surface flatness is crucial, such as for the surface coating of plastic lenses.
Dizeux, Alexandre; Payen, Thomas; Le Guillou-Buffello, Delphine; Comperat, Eva; Gennisson, Jean-Luc; Tanter, Mickael; Oelze, Michael; Bridal, S Lori
2017-09-01
Longitudinal imaging techniques are needed that can meaningfully probe the tumor microenvironment and its spatial heterogeneity. Contrast-enhanced ultrasound, shear wave elastography and quantitative ultrasound are ultrasound-based techniques that provide information on the vascular function and micro-/macroscopic tissue structure. Modifications of the tumor microenvironment induced by cytotoxic and anti-angiogenic molecules in ectopic murine Lewis lung carcinoma tumors were monitored. The most heterogenous structures were found in tumors treated with anti-angiogenic drug that simultaneously accumulated the highest levels of necrosis and fibrosis. The anti-angiogenic group presented the highest number of correlations between parameters related to vascular function and those related to the micro-/macrostructure of the tumor microenvironment. Results suggest how patterns of multiparametric ultrasound modifications can be related to provide a more insightful marker of changes occurring within tumors during therapy. Copyright © 2017. Published by Elsevier Inc.
Cloning Endangered Felids by Interspecies Somatic Cell Nuclear Transfer.
Gómez, Martha C; Pope, C Earle
2015-01-01
In 2003, the first wild felid was produced by interspecies somatic cell nuclear transfer. Since then other wild felid clone offspring have been produced by using the same technique with minor modifications. This chapter describes detailed protocols used in our laboratory for (1) the isolation, culture, and preparation of fibroblast cells as donor nucleus, and (2) embryo reconstruction with domestic cat enucleated oocytes to produce cloned embryos that develop to the blastocyst stage in vitro and, after transfer into synchronized recipients, establish successful pregnancies.
Planning Complex Projects Automatically
NASA Technical Reports Server (NTRS)
Henke, Andrea L.; Stottler, Richard H.; Maher, Timothy P.
1995-01-01
Automated Manifest Planner (AMP) computer program applies combination of artificial-intelligence techniques to assist both expert and novice planners, reducing planning time by orders of magnitude. Gives planners flexibility to modify plans and constraints easily, without need for programming expertise. Developed specifically for planning space shuttle missions 5 to 10 years ahead, with modifications, applicable in general to planning other complex projects requiring scheduling of activities depending on other activities and/or timely allocation of resources. Adaptable to variety of complex scheduling problems in manufacturing, transportation, business, architecture, and construction.
2000-12-01
Biological Weapons Convention and the 1977 Convention on the Prohibition of Military or Other Hostile Use of Environ- mental Modification Techniques...of the Development, Production and Stockpiling of Bacteriological ( Biological ) and Toxin Weapons , and on their Destruction, Lon- don/Washington...125 (1996). —————. “The Regulation of Biological and Chemical Weapons .” In Fox, H. and Meyer, M., Effective Compliance. Armed Conflict and the New Law
Composite casting/bonding construction of an air-cooled, high temperature radial turbine wheel
NASA Technical Reports Server (NTRS)
Hammer, A. N.; Aigret, G.; Rodgers, C.; Metcalfe, A. G.
1983-01-01
A composite casting/bonding technique has been developed for the fabrication of a unique air-cooled, high temperature radial inflow turbine wheel design applicable to auxilliary power units with small rotor diameters and blade entry heights. The 'split blade' manufacturing procedure employed is an alternative to complex internal ceramic coring. Attention is given to both aerothermodynamic and structural design, of which the latter made advantageous use of the exploration of alternative cooling passage configurations through CAD/CAM system software modification.
MISSION: Mission and Safety Critical Support Environment. Executive overview
NASA Technical Reports Server (NTRS)
Mckay, Charles; Atkinson, Colin
1992-01-01
For mission and safety critical systems it is necessary to: improve definition, evolution and sustenance techniques; lower development and maintenance costs; support safe, timely and affordable system modifications; and support fault tolerance and survivability. The goal of the MISSION project is to lay the foundation for a new generation of integrated systems software providing a unified infrastructure for mission and safety critical applications and systems. This will involve the definition of a common, modular target architecture and a supporting infrastructure.
A multilevel control approach for a modular structured space platform
NASA Technical Reports Server (NTRS)
Chichester, F. D.; Borelli, M. T.
1981-01-01
A three axis mathematical representation of a modular assembled space platform consisting of interconnected discrete masses, including a deployable truss module, was derived for digital computer simulation. The platform attitude control system as developed to provide multilevel control utilizing the Gauss-Seidel second level formulation along with an extended form of linear quadratic regulator techniques. The objectives of the multilevel control are to decouple the space platform's spatial axes and to accommodate the modification of the platform's configuration for each of the decoupled axes.
Utilizing the permafrost on Mars
NASA Technical Reports Server (NTRS)
Phillips, L.
1985-01-01
It is noted that analogy between earth landforms resulting from the presence of permafrost has led to the suggestion that ground ice or water was at one time present on Mars. Only a regolith sample will confirm this. With these technologies as background, and known locations of subsurface water, development of a water supply base on Mars can then assume validity and significance. Current practices in terrestrial periglacial environments may be applicable to the Martian situation, taking into account site specific modifications of these techniques.
An integrated environment for tactical guidance research and evaluation
NASA Technical Reports Server (NTRS)
Goodrich, Kenneth H.; Mcmanus, John W.
1990-01-01
NASA-Langley's Tactical Guidance Research and Evaluation System (TGRES) constitutes an integrated environment for the development of tactical guidance algorithms and evaluating the effects of novel technologies; the modularity of the system allows easy modification or replacement of system elements in order to conduct evaluations of alternative technologies. TGRES differs from existing systems in its capitalization on AI programming techniques for guidance-logic implementation. Its ability to encompass high-fidelity, six-DOF simulation models will facilitate the analysis of complete aircraft dynamics.
Magnetic nanoparticles: preparation, physical properties, and applications in biomedicine
2012-01-01
Finally, we have addressed some relevant findings on the importance of having well-defined synthetic strategies developed for the generation of MNPs, with a focus on particle formation mechanism and recent modifications made on the preparation of monodisperse samples of relatively large quantities not only with similar physical features, but also with similar crystallochemical characteristics. Then, different methodologies for the functionalization of the prepared MNPs together with the characterization techniques are explained. Theorical views on the magnetism of nanoparticles are considered. PMID:22348683
NASA Astrophysics Data System (ADS)
Przybylak, Marcin; Maciejewski, Hieronim; Dutkiewicz, Agnieszka
2016-11-01
The surface modification of cotton fabrics was carried out using two types of bifunctional fluorinated silsesquioxanes with different ratios of functional groups. The modification was performed either by one- or two-step process. Two methods, the sol-gel and the dip coating method were used in different configurations. The heat treatment and the washing process were applied after modification. The wettability of cotton fabric was evaluated by measuring water contact angles (WCA). Changes in the surface morphology were examined by scanning electron microscopy (SEM, SEM-LFD) and atomic force microscopy (AFM). Moreover, the modified fabrics were subjected to analysis of elemental composition of the applied coatings using SEM-EDS techniques. Highly hydrophobic textiles were obtained in all cases studied and one of the modifications resulted in imparting superhydrophobic properties. Most of impregnated textiles remained hydrophobic even after multiple washing process which shows that the studied modification is durable.
Sustainable steric stabilization of colloidal titania nanoparticles
NASA Astrophysics Data System (ADS)
Elbasuney, Sherif
2017-07-01
A route to produce a stable colloidal suspension is essential if mono-dispersed particles are to be successfully synthesized, isolated, and used in subsequent nanocomposite manufacture. Dispersing nanoparticles in fluids was found to be an important approach for avoiding poor dispersion characteristics. However, there is still a great tendency for colloidal nanoparticles to flocculate over time. Steric stabilization can prevent coagulation by introducing a thick adsorbed organic layer which constitutes a significant steric barrier that can prevent the particle surfaces from coming into direct contact. One of the main features of hydrothermal synthesis technique is that it offers novel approaches for sustainable nanoparticle surface modification. This manuscript reports on the sustainable steric stabilization of titanium dioxide nanoparticles. Nanoparticle surface modification was performed via two main approaches including post-synthesis and in situ surface modification. The tuneable hydrothermal conditions (i.e. temperature, pressure, flow rates, and surfactant addition) were optimized to enable controlled steric stabilization in a continuous fashion. Effective post synthesis surface modification with organic ligand (dodecenyl succinic anhydride (DDSA)) was achieved; the optimum surface coating temperature was reported to be 180-240 °C to ensure DDSA ring opening and binding to titania nanoparticles. Organic-modified titania demonstrated complete change in surface properties from hydrophilic to hydrophobic and exhibited phase transfer from the aqueous phase to the organic phase. Exclusive surface modification in the reactor was found to be an effective approach; it demonstrated surfactant loading level 2.2 times that of post synthesis surface modification. Titania was also stabilized in aqueous media using poly acrylic acid (PAA) as polar polymeric dispersant. PAA-titania nanoparticles demonstrated a durable amorphous polymeric layer of 2 nm thickness. This manuscript revealed the state of the art for the real development of stable colloidal mono-dispersed particles with controlled surface properties.
Biochemical systems approaches for the analysis of histone modification readout.
Soldi, Monica; Bremang, Michael; Bonaldi, Tiziana
2014-08-01
Chromatin is the macromolecular nucleoprotein complex that governs the organization of genetic material in the nucleus of eukaryotic cells. In chromatin, DNA is packed with histone proteins into nucleosomes. Core histones are prototypes of hyper-modified proteins, being decorated by a large number of site-specific reversible and irreversible post-translational modifications (PTMs), which contribute to the maintenance and modulation of chromatin plasticity, gene activation, and a variety of other biological processes and disease states. The observations of the variety, frequency and co-occurrence of histone modifications in distinct patterns at specific genomic loci have led to the idea that hPTMs can create a molecular barcode, read by effector proteins that translate it into a specific transcriptional state, or process, on the underlying DNA. However, despite the fact that this histone-code hypothesis was proposed more than 10 years ago, the molecular details of its working mechanisms are only partially characterized. In particular, two questions deserve specific investigation: how the different modifications associate and synergize into patterns and how these PTM configurations are read and translated by multi-protein complexes into a specific functional outcome on the genome. Mass spectrometry (MS) has emerged as a versatile tool to investigate chromatin biology, useful for both identifying and validating hPTMs, and to dissect the molecular determinants of histone modification readout systems. We review here the MS techniques and the proteomics methods that have been developed to address these fundamental questions in epigenetics research, emphasizing approaches based on the proteomic dissection of distinct native chromatin regions, with a critical evaluation of their present challenges and future potential. This article is part of a Special Issue entitled: Molecular mechanisms of histone modification function. Copyright © 2014 Elsevier B.V. All rights reserved.
Effects of wing modification on an aircraft's aerodynamic parameters as determined from flight data
NASA Technical Reports Server (NTRS)
Hess, R. A.
1986-01-01
A study of the effects of four wing-leading-edge modifications on a general aviation aircraft's stability and control parameters is presented. Flight data from the basic aircraft configuration and configurations with wing modifications are analyzed to determine each wing geometry's stability and control parameters. The parameter estimates and aerodynamic model forms are obtained using the stepwise regression and maximum likelihood techniques. The resulting parameter estimates and aerodynamic models are verified using vortex-lattice theory and by analysis of each model's ability to predict aircraft behavior. Comparisons of the stability and control derivative estimates from the basic wing and the four leading-edge modifications are accomplished so that the effects of each modification on aircraft stability and control derivatives can be determined.
Three pledget technique for closure of muscular ventricular septal defects.
Sharma, Rajesh; Katewa, Ashish
2012-07-01
We propose a modification of the simple, horizontal mattress, pledgetted suture technique for closing the small muscular ventricular septal defect (VSD) by interposing an oversized third pledget on the left ventricular (LV) aspect of the defect.
Nanoscale fabrication using single-ion impacts
NASA Astrophysics Data System (ADS)
Millar, Victoria; Pakes, Chris I.; Cimmino, Alberto; Brett, David; Jamieson, David N.; Prawer, Steven D.; Yang, Changyi; Rout, Bidhudutta; McKinnon, Rita P.; Dzurak, Andrew S.; Clark, Robert G.
2001-11-01
We describe a novel technique for the fabrication of nanoscale structures, based on the development of localized chemical modification caused in a PMMA resist by the implantation of single ions. The implantation of 2 MeV He ions through a thin layer of PMMA into an underlying silicon substrate causes latent damage in the resist. On development of the resist we demonstrate the formation within the PMMA layer of clearly defined etched holes, of typical diameter 30 nm, observed using an atomic force microscope employing a carbon nanotube SPM probe in intermittent-contact mode. This technique has significant potential applications. Used purely to register the passage of an ion, it may be a useful verification of the impact sites in an ion-beam modification process operating at the single-ion level. Furthermore, making use of the hole in the PMMA layer to perform subsequent fabrication steps, it may be applied to the fabrication of self-aligned structures in which surface features are fabricated directly above regions of an underlying substrate that are locally doped by the implanted ion. Our primary interest in single-ion resists relates to the development of a solid-state quantum computer based on an array of 31P atoms (which act as qubits) embedded with nanoscale precision in a silicon matrix. One proposal for the fabrication of such an array is by phosphorous-ion implantation. A single-ion resist would permit an accurate verification of 31P implantation sites. Subsequent metalisation of the latent damage may allow the fabrication of self-aligned metal gates above buried phosphorous atoms.
The Use of a Code-generating System for the Derivation of the Equations for Wind Turbine Dynamics
NASA Astrophysics Data System (ADS)
Ganander, Hans
2003-10-01
For many reasons the size of wind turbines on the rapidly growing wind energy market is increasing. Relations between aeroelastic properties of these new large turbines change. Modifications of turbine designs and control concepts are also influenced by growing size. All these trends require development of computer codes for design and certification. Moreover, there is a strong desire for design optimization procedures, which require fast codes. General codes, e.g. finite element codes, normally allow such modifications and improvements of existing wind turbine models. This is done relatively easy. However, the calculation times of such codes are unfavourably long, certainly for optimization use. The use of an automatic code generating system is an alternative for relevance of the two key issues, the code and the design optimization. This technique can be used for rapid generation of codes of particular wind turbine simulation models. These ideas have been followed in the development of new versions of the wind turbine simulation code VIDYN. The equations of the simulation model were derived according to the Lagrange equation and using Mathematica®, which was directed to output the results in Fortran code format. In this way the simulation code is automatically adapted to an actual turbine model, in terms of subroutines containing the equations of motion, definitions of parameters and degrees of freedom. Since the start in 1997, these methods, constituting a systematic way of working, have been used to develop specific efficient calculation codes. The experience with this technique has been very encouraging, inspiring the continued development of new versions of the simulation code as the need has arisen, and the interest for design optimization is growing.
Methodological guidelines for developing accident modification functions.
Elvik, Rune
2015-07-01
This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use the guidelines. The importance of exploratory analysis and an iterative approach in developing accident modification functions is stressed. The example shows that strict compliance with all the guidelines may be difficult, but represents a level of stringency that should be strived for. Currently the main limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. Copyright © 2015 Elsevier Ltd. All rights reserved.
Basic procedures for epigenetic analysis in plant cell and tissue culture.
Rodríguez, José L; Pascual, Jesús; Viejo, Marcos; Valledor, Luis; Meijón, Mónica; Hasbún, Rodrigo; Yrei, Norma Yague; Santamaría, María E; Pérez, Marta; Fernández Fraga, Mario; Berdasco, María; Rodríguez Fernández, Roberto; Cañal, María J
2012-01-01
In vitro culture is one of the most studied techniques, and it is used to study many developmental processes, especially in forestry species, because of growth timing and easy manipulation. Epigenetics has been shown as an important influence on many research analyses such as cancer in mammals and developmental processes in plants such as flowering, but regarding in vitro culture, techniques to study DNA methylation or chromatin modifications were mainly limited to identify somaclonal variation of the micropropagated material. Because in vitro culture is not only a way to generate plant material but also a bunch of differentially induced developmental processes, an approach of techniques and some research carried out to study the different changes regarding DNA methylation and chromatin and translational modifications that take place during these processes is reviewed.
Satellite detection of smoke plumes and inadvertant weather modification
Wayne A. Pettyjohn; John B. McKeon
1976-01-01
Satellite imagery provides a convenient and inexpensive means for monitoring smoke plumes and evaluating inadvertant weather modification. Visual examination of LANDSAT-1 imagery for two sites in east-central Ohio indicates that, at times, a plume may extend nearly 48 km downwind and reach a width of six km. Density slicing techniques provide clues as to the...
Behavior Modification for Children with Autistic Tendencies; Study Guide for a Videotaped Series.
ERIC Educational Resources Information Center
Ackerman, Arthur; Dirr, Peter J.
The study guide accompanies a series of 28 videotaped programs designed to provide teachers, teacher aides and parents with an understanding of children with autistic tendencies and of how behavior modification techniques might be used to train such children. Synopses of each program and each program segment and a few questions intended to…
ERIC Educational Resources Information Center
Kogan, Denis
2015-01-01
The purpose of this action research proposal is to create a Modification of Instruments and Tools in Science (MITS) program to address the need for providing Students With Disabilities (SWDs) appropriate access to scientific tools and techniques of scientific inquiry. This proposal contains a review of literature on SWDs, differentiating…
Single-stage autologous ear reconstruction for microtia.
Kasrai, Leila; Snyder-Warwick, Alison K; Fisher, David M
2014-03-01
The authors have been using the Nagata technique since 2002. In this review of 100 consecutive ear reconstructions, the authors present technique modifications that have evolved over this period that have contributed to improved auricular contour and that now allow for auricular reconstruction in a single stage. This study is a retrospective review of a prospectively acquired database. The series is restricted to primary reconstructions performed for congenital microtia. Photographs of 10 consecutive patients are presented to demonstrate the results of the technique. Surgical complication rates are discussed. One hundred ear reconstructions were performed in 96 patients. There were 75 primary cases of congenital microtia. Twenty-four ears underwent a two-stage reconstruction, and 51 ears were reconstructed with a Nagata stage I procedure or a single-stage reconstruction. There was a gradual shift in technique, with a trend to perform fewer Nagata stage II outsetting procedures and more single-stage reconstructions. In patients who underwent an ear reconstruction in two stages, the surgical complication rate was 22 percent. In the last 40 consecutive ear reconstructions since abandoning the two-stage approach, the surgical complication rate is now 15 percent. A modification of Nagata's technique of autologous ear reconstruction for microtia is described. Modifications of the three-dimensional framework address the contour of the inferior crus and control tragal projection and position. Inclusion of a projection block and recruitment of retroauricular skin allow for symmetric projection of the ear in a single stage. Therapeutic, IV.
Hoag, Nathan; Gani, Johan; Chee, Justin
2016-07-01
To present a novel modification of surgical technique to treat female urethral stricture (FUS) by a vaginal-sparing ventral buccal mucosal urethroplasty. Recurrent FUS represents an uncommon, though difficult clinical scenario to manage definitively. A variety of surgical techniques have been described to date, yet a lack of consensus on the optimal procedure persists. We present a 51-year-old female with urethral stricture involving the entire urethra. Suspected etiology was iatrogenic from cystoscopy 17 years prior. Since then, the patient had undergone at least 25 formal urethral dilations and periods of self-dilation. In lithotomy position, the urethra was dilated to accommodate forceps, and ventral urethrotomy carried out sharply, exposing a bed of periurethral tissue. Buccal mucosa was harvested, and a ventral inlay technique facilitated by a nasal speculum, was used to place the graft from the proximal urethra/bladder neck to urethral meatus without a vaginal incision. Graft was sutured into place, and urethral Foley catheter inserted. The vaginal-sparing ventral buccal mucosal graft urethroplasty was deemed successful as of last follow-up. Flexible cystoscopy demonstrated patency of the repair at 6 months. At 10 months of follow-up, the patient was voiding well, with no urinary incontinence. No further interventions have been required. This case describes a novel modification of surgical technique for performing buccal mucosal urethroplasty for FUS. By avoiding incision of the vaginal mucosa, benefits may include reduced: morbidity, urinary incontinence, and wound complications including urethro-vaginal fistula.
Chemical vapor deposition growth
NASA Technical Reports Server (NTRS)
Ruth, R. P.; Manasevit, H. M.; Campbell, A. G.; Johnson, R. E.; Kenty, J. L.; Moudy, L. A.; Shaw, G. L.; Simpson, W. I.; Yang, J. J.
1978-01-01
The objective was to investigate and develop chemical vapor deposition (CVD) techniques for the growth of large areas of Si sheet on inexpensive substrate materials, with resulting sheet properties suitable for fabricating solar cells that would meet the technical goals of the Low Cost Silicon Solar Array Project. The program involved six main technical tasks: (1) modification and test of an existing vertical-chamber CVD reactor system; (2) identification and/or development of suitable inexpensive substrate materials; (3) experimental investigation of CVD process parameters using various candidate substrate materials; (4) preparation of Si sheet samples for various special studies, including solar cell fabrication; (5) evaluation of the properties of the Si sheet material produced by the CVD process; and (6) fabrication and evaluation of experimental solar cell structures, using impurity diffusion and other standard and near-standard processing techniques supplemented late in the program by the in situ CVD growth of n(+)/p/p(+) sheet structures subsequently processed into experimental cells.
Gorshkov, Anton V; Kirillin, Mikhail Yu
2015-08-01
Over two decades, the Monte Carlo technique has become a gold standard in simulation of light propagation in turbid media, including biotissues. Technological solutions provide further advances of this technique. The Intel Xeon Phi coprocessor is a new type of accelerator for highly parallel general purpose computing, which allows execution of a wide range of applications without substantial code modification. We present a technical approach of porting our previously developed Monte Carlo (MC) code for simulation of light transport in tissues to the Intel Xeon Phi coprocessor. We show that employing the accelerator allows reducing computational time of MC simulation and obtaining simulation speed-up comparable to GPU. We demonstrate the performance of the developed code for simulation of light transport in the human head and determination of the measurement volume in near-infrared spectroscopy brain sensing.
Kumar, Manoj; Singh, Rajendra; Meena, Anil; Patidar, Bhagwan S; Prasad, Rajendra; Chhabra, Sunil K; Bansal, Surendra K
2017-01-01
The 2-dimensional gel electrophoresis (2-DE) technique is widely used for the analysis of complex protein mixtures extracted from biological samples. It is one of the most commonly used analytical techniques in proteomics to study qualitative and quantitative protein changes between different states of a cell or an organism (eg, healthy and diseased), conditionally expressed proteins, posttranslational modifications, and so on. The 2-DE technique is used for its unparalleled ability to separate thousands of proteins simultaneously. The resolution of the proteins by 2-DE largely depends on the quality of sample prepared during protein extraction which increases results in terms of reproducibility and minimizes protein modifications that may result in artifactual spots on 2-DE gels. The buffer used for the extraction and solubilization of proteins influences the quality and reproducibility of the resolution of proteins on 2-DE gel. The purification by cleanup kit is another powerful process to prevent horizontal streaking which occurs during isoelectric focusing due to the presence of contaminants such as salts, lipids, nucleic acids, and detergents. Erythrocyte membrane proteins serve as prototypes for multifunctional proteins in various erythroid and nonerythroid cells. In this study, we therefore optimized the selected major conditions of 2-DE for resolving various proteins of human erythrocyte membrane. The modification included the optimization of conditions for sample preparation, cleanup of protein sample, isoelectric focusing, equilibration, and storage of immobilized pH gradient strips, which were further carefully examined to achieve optimum conditions for improving the quality of protein spots on 2-DE gels. The present improved 2-DE analysis method enabled better detection of protein spots with higher quality and reproducibility. Therefore, the conditions established in this study may be used for the 2-DE analysis of erythrocyte membrane proteins for different diseases, which may help to identify the proteins that may serve as markers for diagnostics as well as targets for development of new therapeutic potential. PMID:28469466
High-Order Energy Stable WENO Schemes
NASA Technical Reports Server (NTRS)
Yamaleev, Nail K.; Carpenter, Mark H.
2009-01-01
A third-order Energy Stable Weighted Essentially Non-Oscillatory (ESWENO) finite difference scheme developed by Yamaleev and Carpenter was proven to be stable in the energy norm for both continuous and discontinuous solutions of systems of linear hyperbolic equations. Herein, a systematic approach is presented that enables 'energy stable' modifications for existing WENO schemes of any order. The technique is demonstrated by developing a one-parameter family of fifth-order upwind-biased ESWENO schemes; ESWENO schemes up to eighth order are presented in the appendix. New weight functions are also developed that provide (1) formal consistency, (2) much faster convergence for smooth solutions with an arbitrary number of vanishing derivatives, and (3) improved resolution near strong discontinuities.
Recent advances in the chemical modification of unsaturated polymers
NASA Technical Reports Server (NTRS)
Schulz, D. N.; Turner, S. R.; Golub, M. A.
1982-01-01
The present discussion has the objective to update the most comprehensive reviews on the considered subject and to fill in the gaps of less complete, but more modern treatments. Only simple chemical functionalization or structural modification of unsaturated polymers are covered, and the literature of diene polymer modification since 1974 is emphasized. Attention is given to hydrogenation, halogenation and hydrohalogenation, cyclization, cis-trans isomerization, epoxidation, ene and other cycloaddition reactions, sulfonation, carboxylation, phosphonylation, sulfenyl chloride addition, carbene addition, metalation, and silylation. It is pointed out that modern synthetic reagents and catalysts have been advantageously employed to improve process and/or product quality. Synthetic techniques have been refined to allow the selective modification of specific polymer microstructures or blocks.
Plasma assisted surface coating/modification processes - An emerging technology
NASA Technical Reports Server (NTRS)
Spalvins, T.
1987-01-01
A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation. These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.
Plasma assisted surface coating/modification processes: An emerging technology
NASA Technical Reports Server (NTRS)
Spalvins, T.
1986-01-01
A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation). These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.
Modification of smoothing in 4253H[T
NASA Astrophysics Data System (ADS)
Azmi, Nurul Nisa'Khairol; Adam, Mohd Bakri; Shitan, Mahendran; Ali, Norhaslinda Mohd
2017-05-01
Some modified non-linear smoothers particularly 4253H[T] are explained in this paper. The modifications are focused on estimating the middle point of running median for even span by applying the following types of means; geometric, harmonic, quadratic and contraharmonic. The performance of the techniques is assessed by applying it to daily price index of a bank in Malaysia that issues sukuk for funding in Islamic banking and financial business. The results show that 4253H[T] with geometric mean modification is better than others in preserving variation and curve fitting.
Speckle contrast techniques in the study of tissue thermal modification and denaturation
NASA Astrophysics Data System (ADS)
Agafonov, Dmitry N.; Kuznetsova, Liana V.; Zimnyakov, Dmitry A.; Sviridov, Alexander P.; Omelchenko, Alexander I.
2002-05-01
Results of the contrast analysis of time-averaged dynamic speckle patterns in application to monitoring of the structure modification of the thermally treated collagenous tissue such as cartilage are presented. The modification presumably induced by the bound to free water phase transition in the matrix of the treated tissue cause the specific feature of evolution of the time-averaged speckle contrast with the change of the current temperature of modified collagen tissue. This evolution appears as hysteresis associated with irreversible changes in tissue structure.
NASA Astrophysics Data System (ADS)
Pandey, M.; Banerjee, D.; Sudarsan, V.; Kshirsagar, R. J.
2018-04-01
Effect of TiO2 addition in Cs containing Sodium-borosilicate glasses is studied using Raman and infrared spectroscopic techniques. As revealed from infrared and Raman studies, TiO2 does not form segregated phase, but instead enters into the borosilicate network. It is further observed that TiO2 addition results in modifications of the borate and silicate structural units by transforming into tetraborates and metasilicate structural units. These structural modifications are responsible for Cs immobilization, leach rate and chemical durability of these glasses.
Means to Overcome the Anxieties of Second Language Learners.
ERIC Educational Resources Information Center
McCoy, Ingeborg R.
1979-01-01
Behavior modification techniques that can be used to overcome fears and anxieties of students and to further achievement in second language learning are discussed. The following techniques are covered: systematic desensitization, cognitive restructuring, and modeling and guided participation. (SW)
Alaboina, Pankaj Kumar; Uddin, Md-Jamal; Cho, Sung-Jin
2017-10-26
Nanotechnology-driven development of cathode materials is an essential part to revolutionize the evolution of the next generation lithium ion batteries. With the progress of nanoprocess and nanoscale surface modification investigations on cathode materials in recent years, the advanced battery technology future seems very promising - Thanks to nanotechnology. In this review, an overview of promising nanoscale surface deposition methods and their significance in surface functionalization on cathodes is extensively summarized. Surface modified cathodes are provided with a protective layer to overcome the electrochemical performance limitations related to side reactions with electrolytes, reduce self-discharge reactions, improve thermal and structural stability, and further enhance the overall battery performance. The review addresses the importance of nanoscale surface modification on battery cathodes and concludes with a comparison of the different nanoprocess techniques discussed to provide a direction in the race to build advanced lithium-ion batteries.
Pluripotent Stem Cells and Gene Therapy
Simara, Pavel; Motl, Jason A.; Kaufman, Dan S.
2013-01-01
Human pluripotent stem cells represent an accessible cell source for novel cell-based clinical research and therapies. With the realization of induced pluripotent stem cells (iPSCs), it is possible to produce almost any desired cell type from any patient's cells. Current developments in gene modification methods have opened the possibility for creating genetically corrected human iPSCs for certain genetic diseases that could be used later in autologous transplantation. Promising preclinical studies have demonstrated correction of disease-causing mutations in a number of hematological, neuronal and muscular disorders. This review aims to summarize these recent advances with a focus on iPSC generation techniques, as well as gene modification methods. We will then further discuss some of the main obstacles remaining to be overcome before successful application of human pluripotent stem cell-based therapy arrives in the clinic and what the future of stem cell research may look like. PMID:23353080
Nasreen, Shaik Anwar Ahamed Nabeela; Sundarrajan, Subramanian; Nizar, Syed Abdulrahim Syed; Balamurugan, Ramalingam; Ramakrishna, Seeram
2013-01-01
Water, among the most valuable natural resources available on earth, is under serious threat as a result of undesirable human activities: for example, marine dumping, atmospheric deposition, domestic, industrial and agricultural practices. Optimizing current methodologies and developing new and effective techniques to remove contaminants from water is the current focus of interest, in order to renew the available water resources. Materials like nanoparticles, polymers, and simple organic compounds, inorganic clay materials in the form of thin film, membrane or powder have been employed for water treatment. Among these materials, membrane technology plays a vital role in removal of contaminants due to its easy handling and high efficiency. Though many materials are under investigation, nanofibers driven membrane are more valuable and reliable. Synthetic methodologies applied over the modification of membrane and its applications in water treatment have been reviewed in this article. PMID:24957057
Social and ethical issues in mitochondrial donation.
Dimond, Rebecca
2015-09-01
The UK is at the forefront of mitochondrial science and is currently the only country in the world to legalize germ-line technologies involving mitochondrial donation. However, concerns have been raised about genetic modification and the 'slippery slope' to designer babies. This review uses academic articles, newspaper reports and public documents. Mitochondrial donation offers women with mitochondrial disease an opportunity to have healthy, genetically related children. Key areas of disagreement include safety, the creation of three-parent babies, impact on identity, implications for society, definitions of genetic modification and reproductive choice. The UK government legalized the techniques in March 2015. Scientific and medical communities across the world followed the developments with interest. It is expected that the first cohort of 'three parent' babies will be born in the UK in 2016. Their health and progress will be closely monitored. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
The ERL-based Design of Electron-Hadron Collider eRHIC
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ptitsyn, Vadim
2016-06-01
Recent developments of the ERL-based design of future high-luminosity electron-hadron collider eRHIC focused on balancing technological risks present in the design versus the design cost. As a result a lower risk design has been adopted at moderate cost increase. The modifications include a change of the main linac RF frequency, reduced number of SRF cavity types and modified electron spin transport using a spin rotator. A luminosity-staged approach is being explored with a Nominal design (more » $$L \\sim 10^{33} {\\rm cm}^2 {\\rm s}^{-1}$$) that employs reduced electron current and could possibly be based on classical electron cooling, and then with the Ultimate design ($$L \\gt 10^{34} {\\rm cm}^{-2} {\\rm s}^{-1}$$) that uses higher electron current and an innovative cooling technique (CeC). The paper describes the recent design modifications, and presents the full status of the eRHIC ERL-based design.« less
Gigacycle fatigue behavior by ultrasonic nanocrystalline surface modification.
Ahn, D G; Amanov, A; Cho, I S; Shin, K S; Pyoun, Y S; Lee, C S; Park, I G
2012-07-01
Nanocrystalline surface layer up to 84 microm in thick is produced on a specimen made of Al6061-T6 alloy by means of surface treatment called ultrasonic nanocrystalline surface modification (UNSM) technique. The refined grain size is produced in the top-layer and it is increased with increasing depth from the top surface. Vickers microhardness measurement for each nanocrystalline surface layer is performed and measurement results showed that the microhardness is increased from 116 HV up to 150 HV, respectively. In this study, fatigue behavior of Al6061-T6 alloy was studied up to 10(7)-10(9) cycles by using a newly developed ultrasonic fatigue testing (UFT) rig. The fatigue results of the UNSM-treated Al6061-T6 alloy specimens were compared with those of the untreated specimens. The microstructure of the untreated and UNSM-treated specimens was characterized by means of scanning electron microscopey (SEM) and transmission electron microscopey (TEM).
High-level production of C-11-carboxyl-labeled amino acids. [For use in tumor and pancreatic imaging
DOE Office of Scientific and Technical Information (OSTI.GOV)
Washburn, L. C.; Sun, T. T.; Byrd, B. L.
Carbon-11-labeled amino acids have significant potential as agents for positron tomographic functional imaging. We have developed a rapid, high-temperature, high-pressure modification of the Buecherer--Strecker amino acid synthesis and found it to be quite general for the production of C-11-carboxyl-labeled neutral amino acids. Production of C-11-carboxyl-labeled DL-tryptophan requires certain modifications in the procedure. Twelve different amino acids have been produced to date by this technique. Synthesis and chromatographic purification require approximately 40 min, and C-11-carboxyl-labeled amino acids have been produced in yields of up to 425 mCi. Two C-11-carboxyl-labeled amino acids are being investigated clinically for tumor scanning and two othersmore » for pancreatic imaging. Over 120 batches of the various agents have been produced for clinical use over a three-year period.« less
Dudley, Robert W.
2015-12-03
The largest average errors of prediction are associated with regression equations for the lowest streamflows derived for months during which the lowest streamflows of the year occur (such as the 5 and 1 monthly percentiles for August and September). The regression equations have been derived on the basis of streamflow and basin characteristics data for unregulated, rural drainage basins without substantial streamflow or drainage modifications (for example, diversions and (or) regulation by dams or reservoirs, tile drainage, irrigation, channelization, and impervious paved surfaces), therefore using the equations for regulated or urbanized basins with substantial streamflow or drainage modifications will yield results of unknown error. Input basin characteristics derived using techniques or datasets other than those documented in this report or using values outside the ranges used to develop these regression equations also will yield results of unknown error.
Hypersonic code efficiency and validation studies
NASA Technical Reports Server (NTRS)
Bennett, Bradford C.
1992-01-01
Renewed interest in hypersonic and supersonic flows spurred the development of the Compressible Navier-Stokes (CNS) code. Originally developed for external flows, CNS was modified to enable it to also be applied to internal high speed flows. In the initial phase of this study CNS was applied to both internal flow applications and fellow researchers were taught to run CNS. The second phase of this research was the development of surface grids over various aircraft configurations for the High Speed Research Program (HSRP). The complex nature of these configurations required the development of improved surface grid generation techniques. A significant portion of the grid generation effort was devoted to testing and recommending modifications to early versions of the S3D surface grid generation code.
Robust large-scale parallel nonlinear solvers for simulations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bader, Brett William; Pawlowski, Roger Patrick; Kolda, Tamara Gibson
2005-11-01
This report documents research to develop robust and efficient solution techniques for solving large-scale systems of nonlinear equations. The most widely used method for solving systems of nonlinear equations is Newton's method. While much research has been devoted to augmenting Newton-based solvers (usually with globalization techniques), little has been devoted to exploring the application of different models. Our research has been directed at evaluating techniques using different models than Newton's method: a lower order model, Broyden's method, and a higher order model, the tensor method. We have developed large-scale versions of each of these models and have demonstrated their usemore » in important applications at Sandia. Broyden's method replaces the Jacobian with an approximation, allowing codes that cannot evaluate a Jacobian or have an inaccurate Jacobian to converge to a solution. Limited-memory methods, which have been successful in optimization, allow us to extend this approach to large-scale problems. We compare the robustness and efficiency of Newton's method, modified Newton's method, Jacobian-free Newton-Krylov method, and our limited-memory Broyden method. Comparisons are carried out for large-scale applications of fluid flow simulations and electronic circuit simulations. Results show that, in cases where the Jacobian was inaccurate or could not be computed, Broyden's method converged in some cases where Newton's method failed to converge. We identify conditions where Broyden's method can be more efficient than Newton's method. We also present modifications to a large-scale tensor method, originally proposed by Bouaricha, for greater efficiency, better robustness, and wider applicability. Tensor methods are an alternative to Newton-based methods and are based on computing a step based on a local quadratic model rather than a linear model. The advantage of Bouaricha's method is that it can use any existing linear solver, which makes it simple to write and easily portable. However, the method usually takes twice as long to solve as Newton-GMRES on general problems because it solves two linear systems at each iteration. In this paper, we discuss modifications to Bouaricha's method for a practical implementation, including a special globalization technique and other modifications for greater efficiency. We present numerical results showing computational advantages over Newton-GMRES on some realistic problems. We further discuss a new approach for dealing with singular (or ill-conditioned) matrices. In particular, we modify an algorithm for identifying a turning point so that an increasingly ill-conditioned Jacobian does not prevent convergence.« less
Surface modification techniques for increased corrosion tolerance of zirconium fuel cladding
NASA Astrophysics Data System (ADS)
Carr, James Patrick, IV
Corrosion is a major issue in applications involving materials in normal and severe environments, especially when it involves corrosive fluids, high temperatures, and radiation. Left unaddressed, corrosion can lead to catastrophic failures, resulting in economic and environmental liabilities. In nuclear applications, where metals and alloys, such as steel and zirconium, are extensively employed inside and outside of the nuclear reactor, corrosion accelerated by high temperatures, neutron radiation, and corrosive atmospheres, corrosion becomes even more concerning. The objectives of this research are to study and develop surface modification techniques to protect zirconium cladding by the incorporation of a specific barrier coating, and to understand the issues related to the compatibility of the coatings examined in this work. The final goal of this study is to recommend a coating and process that can be scaled-up for the consideration of manufacturing and economic limits. This dissertation study builds on previous accident tolerant fuel cladding research, but is unique in that advanced corrosion methods are tested and considerations for implementation by industry are practiced and discussed. This work will introduce unique studies involving the materials and methods for accident tolerant fuel cladding research by developing, demonstrating, and considering materials and processes for modifying the surface of zircaloy fuel cladding. This innovative research suggests that improvements in the technique to modify the surface of zirconium fuel cladding are likely. Three elements selected for the investigation of their compatibility on zircaloy fuel cladding are aluminum, silicon, and chromium. These materials are also currently being investigated at other labs as alternate alloys and coatings for accident tolerant fuel cladding. This dissertation also investigates the compatibility of these three elements as surface modifiers, by comparing their microstructural and mechanical properties. To test their application for use in corrosive atmospheres, the corrosion behaviors are also compared in steam, water, and boric-acid environments. Various methods of surface modification were attempted in this investigation, including dip coating, diffusion bonding, casting, sputtering, and evaporation. The benefits and drawbacks of each method are discussed with respect to manufacturing and economic limits. Characterization techniques utilized in this work include optical microscopy, scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, nanoindentation, adhesion testing, and atomic force microscopy. The composition, microstructure, hardness, modulus, and coating adhesion were studied to provide encompassing properties to determine suitable comparisons and to choose an ideal method to scale to industrial applications. The experiments, results, and detailed discussions are presented in the following chapters of this dissertation research.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Toshito, T.; Kodama, K.; Yusa, K.
2006-05-10
We performed an experimental study of charge identification of heavy ions from helium to carbon having energy of about 290 MeV/u using an emulsion chamber. Emulsion was desensitized by means of forced fading (refreshing) to expand a dynamic range of response to highly charged particles. For the track reconstruction and charge identification, the fully automated high speed emulsion read-out system, which was originally developed for identifying minimum ionizing particles, was used without any modification. Clear track by track charge identification up to Z=6 was demonstrated. The refreshing technique has proved to be a powerful technique to expand response of emulsionmore » film to highly ionizing particles.« less
Gapinske, Michael; Tague, Nathan; Winter, Jackson; Underhill, Gregory H; Perez-Pinera, Pablo
2018-01-01
Gene editing technologies are revolutionizing fields such as biomedicine and biotechnology by providing a simple means to manipulate the genetic makeup of essentially any organism. Gene editing tools function by introducing double-stranded breaks at targeted sites within the genome, which the host cells repair preferentially by Non-Homologous End Joining. While the technologies to introduce double-stranded breaks have been extensively optimized, this progress has not been matched by the development of methods to integrate heterologous DNA at the target sites or techniques to detect and isolate cells that harbor the desired modification. We present here a technique for rapid introduction of vectors at target sites in the genome that enables efficient isolation of successfully edited cells.
Turbulence management: Application aspects
NASA Astrophysics Data System (ADS)
Hirschel, E. H.; Thiede, P.; Monnoyer, F.
1989-04-01
Turbulence management for the reduction of turbulent friction drag is an important topic. Numerous research programs in this field have demonstrated that valuable net drag reduction is obtainable by techniques which do not involve substantial, expensive modifications or redesign of existing aircraft. Hence, large projects aiming at short term introduction of turbulence management technology into airline service are presently under development. The various points that have to be investigated for this purpose are presented. Both design and operational aspects are considered, the first dealing with optimizing of turbulence management techniques at operating conditions, and the latter defining the technical problems involved by application of turbulence management to in-service aircraft. The cooperative activities of Airbus Industrie and its partners are cited as an example.
Faris, Callum; Heiser, Alyssa; Jowett, Nate; Hadlock, Tessa
2018-03-01
Creation of symmetrical nasolabial folds (NLFs) is important in the management of the paralyzed face. Established techniques use a linear incision in the NLF, and technical refinements now allow the linear incision to be omitted. This retrospective case series was conducted in a tertiary care setting from February 2, 2017, to June 7, 2017. Participants were all patients (N = 21) with peripheral facial paralysis who underwent NLF modification that used the minimal nasolabial incision technique at the Massachusetts Eye and Ear Infirmary Facial Nerve Center from February 1, 2015, through August 31, 2016. Patient-reported outcome measures using the validated, quality-of-life Facial Clinimetric Evaluation (FaCE) Scale; clinician-reported facial function outcomes using a validated electronic clinician-graded facial paralysis assessment (eFACE); layperson assessment of the overall aesthetic outcome of the NLF; and expert-clinician scar assessment of the NLF. Of the 21 patients who underwent NLF modification that used the minimal nasolabial incision technique, 9 patients (43%) were female and 12 (57%) were male. The mean age was 41 (range, 9-90) years; 17 patients (81%) were adults (≥18 years) and 4 (19%) were children (<18 years). Overall, significant improvements were observed after NLF modification in all outcome measures as graded by both clinicians and patients. The mean (SD) scores for total eFACE were 60.7 (14.9) before the operation and 77.2 (8.9) after the operation (mean difference, 16.5 [95% CI, 8.5-24.2]; P < .001). The mean (SD) static eFACE scores were 61.4 (20.6) before the operation and 82.7 (12.4) after the operation (mean difference, 21.3 [95% CI, 10.7-31.9]; P < .001). The mean (SD) FaCE quality-of-life scores were 51.3 (20.1) before the operation and 70.3 (12.6) after the operation (mean difference, 19.0 [95% CI, 6.5-31.6]; P = .001). The layperson self-assessment of the overall aesthetic outcome of the NLF modification was higher among the group who had the minimal nasolabial incision than it was for the group who had a historical nasolabial incision (mean [SD], 68.17 [13.59] vs 56.28 [13.60]; mean difference, 11.89 [95% CI, 3.81-19.97]; P < .001). Similarly, the expert-clinician scar assessment of the NLF modification was higher for the group who had the minimal nasolabial incision than it was for the group who had a historical nasolabial incision (3.78 [0.91] vs 2.98 [0.81]; mean difference, 0.80 [95% CI, 0.29-1.32]; P = .007). The minimal nasolabial incision technique for NLF modification is effective in rehabilitating the NLF in facial paralysis without adding a long linear scar to the central midface. 4.
NASA Astrophysics Data System (ADS)
Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A.; Cheng, Shuk Han; Sun, Dong
2016-04-01
Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.
Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A; Cheng, Shuk Han; Sun, Dong
2016-04-12
Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.
A design support simulation of the augmentor wing jet STOL research aircraft
NASA Technical Reports Server (NTRS)
Rumsey, P. C.; Spitzer, R. E.; Glende, W. L. B.
1972-01-01
The modification of a C-8A (De Havilland Buffalo) aircraft to a STOL configuration is discussed. The modification consisted of the installation of an augmentor-wing jet flap system. System design requirements were investigated for the lateral and directional flight control systems, the lateral and directional axes stability augmentation systems, the engine and Pegasus nozzle control systems, and the hydraulic systems. Operational techniques for STOL landings, control of engine failures, and pilot techniques for improving engine-out go-around performance were examined. Design changes have been identified to correct deficiencies in areas of the airplane control sytems and to improve the airplane flying qualities.
En bloc sacrectomy and reconstruction: technique modification for pelvic fixation.
Newman, C Benjamin; Keshavarzi, Sassan; Aryan, Henry E
2009-12-01
When the management of sacral tumors requires partial or complete sacrectomy, the spinopelvic apparatus must be reconstructed. This is a challenging and infrequently performed operation, and as such, many spine surgeons are unfamiliar with techniques available to carry out these procedures. A 34-year-old man presented with severe low back pain, mild left ankle dorsiflexion weakness, and left S1 paresthesias. Imaging revealed a large sacral mass extending into the L5/S1 and S1/S2 neural foramina as well as the presacral visceral and vascular structures. Needle biopsy of this mass demonstrated a low-grade chondrosarcoma. A 2-stage anterior/posterior en bloc sacrectomy with a novel modification of the Galveston L-rod pelvic ring reconstruction was carried out. Our modification takes advantage of new materials and implant technology to offer another alternative in reconstruction of the spinopelvic junction. Understanding the anatomy and biomechanics of the spinopelvic apparatus and the lumbosacral junction, as well as having a familiarity with the various techniques available for carrying out sacrectomy and pelvic ring reconstruction, will enable the spine surgeon to effectively manage sacral tumors. Copyright 2009 Elsevier Inc. All rights reserved.
NASA Technical Reports Server (NTRS)
Daly, J. K.
1974-01-01
The programming techniques used to implement the equations and mathematical techniques of the Houston Operations Predictor/Estimator (HOPE) orbit determination program on the UNIVAC 1108 computer are described. Detailed descriptions are given of the program structure, the internal program structure, the internal program tables and program COMMON, modification and maintainence techniques, and individual subroutine documentation.
Goulding, A T; Farrell, A P
2016-05-01
A new, image-based, tritiated ligand technique for measuring cardiac β2 -adrenoceptor (β2 -AR) binding characteristics was developed and validated with adult rainbow trout Oncorhynchus mykiss hearts so that the tissue limitation of traditional receptor binding techniques could be overcome and measurements could be made in hearts nearly 14-times smaller than previously used. The myocardial cell-surface (functional) β2 -AR density of O. nerka smolts sampled at the headwaters of the Chilko River was 54·2 fmol mg protein(-1) and about half of that previously found in return migrating adults of the same population, but still more than twice that of adult hatchery O. mykiss (21·1 fmol mg protein(-1) ). This technique now opens the possibility of investigating cardiac receptor density in a much wider range of fish species and life stages. © 2016 The Fisheries Society of the British Isles.
Retro-peritoneal cooling for kidney preservation from multi-organ cadaver donors.
Salazar-Bañuelos, Anastasio; Monroy-Cuadros, Mauricio; Henriquez-Cooper, Hoover
2018-05-01
Minimizing ischemia is paramount in the procurement of kidneys for transplantation. A fast cooling and expeditious removal is ideal to minimize damage from warm ischemia, however, since the removal of kidneys is delayed in cadaver donation until all other organs are harvested, the risk of kidney damage increases due to contact with the warmer soft body tissues. Surgical techniques that expedite organ retrieval were developed to avoid organ damage. We test a modification of Thomas Starzl's improved technique for multi-organ harvesting by interposing an ice bag between the posterior aspect of the kidney and the psoas muscle in a randomized trial with 21 multi-organ cadaver donors. The modified technique decreases the extraction temperature of the kidneys significantly in comparison with the controls, p < .001. This simple technique improves the preservation of kidneys from cadaver donors, and can potentially have more impact on multi-organ donation after cardiac death. Copyright © 2018 Elsevier Inc. All rights reserved.
The discriminatory power of ribotyping as automatable technique for differentiation of bacteria.
Schumann, Peter; Pukall, Rüdiger
2013-09-01
Since the introduction of ribonucleic acid gene restriction patterns as taxonomic tools in 1986, ribotyping has become an established method for systematics, epidemiological, ecological and population studies of microorganisms. In the last 25 years, several modifications have improved the convenience, reproducibility and turn-around time of this technique. The technological development culminated in the automation of ribotyping which allowed for high-throughput applications e.g. in the quality control of food production, pharmaceutical industry and culture collections. The capability of the fully automated RiboPrinter(®) System for the differentiation of bacteria below the species level is compared with the discriminatory power of traditional ribotyping, of molecular fingerprint techniques like PFGE, MLST and MLVA as well as of MALDI-TOF mass spectrometry. While automated RiboPrinting is advantageous with respect to standardization, ease and speed, PCR ribotyping has proved being a highly discriminatory, flexible, robust and cost-efficient routine technique which makes inter-laboratory comparison and build of ribotype databases possible, too. Copyright © 2013 Elsevier GmbH. All rights reserved.
Optimization of Native and Formaldehyde iPOND Techniques for Use in Suspension Cells.
Wiest, Nathaniel E; Tomkinson, Alan E
2017-01-01
The isolation of proteins on nascent DNA (iPOND) technique developed by the Cortez laboratory allows a previously unparalleled ability to examine proteins associated with replicating and newly synthesized DNA in mammalian cells. Both the original, formaldehyde-based iPOND technique and a more recent derivative, accelerated native iPOND (aniPOND), have mostly been performed in adherent cell lines. Here, we describe modifications to both protocols for use with suspension cell lines. These include cell culture, pulse, and chase conditions that optimize sample recovery in both protocols using suspension cells and several key improvements to the published aniPOND technique that reduce sample loss, increase signal to noise, and maximize sample recovery. Additionally, we directly and quantitatively compare the iPOND and aniPOND protocols to test the strengths and limitations of both. Finally, we present a detailed protocol to perform the optimized aniPOND protocol in suspension cell lines. © 2017 Elsevier Inc. All rights reserved.
Surface modification of protein enhances encapsulation in chitosan nanoparticles
NASA Astrophysics Data System (ADS)
Koyani, Rina D.; Andrade, Mariana; Quester, Katrin; Gaytán, Paul; Huerta-Saquero, Alejandro; Vazquez-Duhalt, Rafael
2018-04-01
Chitosan nanoparticles have a huge potential as nanocarriers for environmental and biomedical purposes. Protein encapsulation in nano-sized chitosan provides protection against inactivation, proteolysis, and other alterations due to environmental conditions, as well as the possibility to be targeted to specific tissues by ligand functionalization. In this work, we demonstrate that the chemical modification of the protein surface enhances the protein loading in chitosan nanocarriers. Encapsulation of green fluorescent protein and the cytochrome P450 was studied. The increase of electrostatic interactions between the free amino groups of chitosan and the increased number of free carboxylic groups in the protein surface enhance the protein loading, protein retention, and, thus, the enzymatic activity of chitosan nanoparticles. The chemical modification of protein surface with malonic acid moieties reduced drastically the protein isoelectric point increasing the protein interaction with the polycationic biomaterial and chitosan. The chemical modification of protein does not alter the morphology of chitosan nanoparticles that showed an average diameter of 18 nm, spheroidal in shape, and smooth surfaced. The strategy of chemical modification of protein surface, shown here, is a simple and efficient technique to enhance the protein loading in chitosan nanoparticles. This technique could be used for other nanoparticles based on polycationic or polyanionic materials. The increase of protein loading improves, doubtless, the performance of protein-loaded chitosan nanoparticles for biotechnological and biomedical applications.
Brabencová, Sylva; Ihnatová, Ivana; Potěšil, David; Fojtová, Miloslava; Fajkus, Jiří; Zdráhal, Zbyněk; Lochmanová, Gabriela
2017-01-01
Inter-individual variability of conspecific plants is governed by differences in their genetically determined growth and development traits, environmental conditions, and adaptive responses under epigenetic control involving histone post-translational modifications. The apparent variability in histone modifications among plants might be increased by technical variation introduced in sample processing during epigenetic analyses. Thus, to detect true variations in epigenetic histone patterns associated with given factors, the basal variability among samples that is not associated with them must be estimated. To improve knowledge of relative contribution of biological and technical variation, mass spectrometry was used to examine histone modification patterns (acetylation and methylation) among Arabidopsis thaliana plants of ecotypes Columbia 0 (Col-0) and Wassilewskija (Ws) homogenized by two techniques (grinding in a cryomill or with a mortar and pestle). We found little difference in histone modification profiles between the ecotypes. However, in comparison of the biological and technical components of variability, we found consistently higher inter-individual variability in histone mark levels among Ws plants than among Col-0 plants (grown from seeds collected either from single plants or sets of plants). Thus, more replicates of Ws would be needed for rigorous analysis of epigenetic marks. Regarding technical variability, the cryomill introduced detectably more heterogeneity in the data than the mortar and pestle treatment, but mass spectrometric analyses had minor apparent effects. Our study shows that it is essential to consider inter-sample variance and estimate suitable numbers of biological replicates for statistical analysis for each studied organism when investigating changes in epigenetic histone profiles. PMID:29270186
Brabencová, Sylva; Ihnatová, Ivana; Potěšil, David; Fojtová, Miloslava; Fajkus, Jiří; Zdráhal, Zbyněk; Lochmanová, Gabriela
2017-01-01
Inter-individual variability of conspecific plants is governed by differences in their genetically determined growth and development traits, environmental conditions, and adaptive responses under epigenetic control involving histone post-translational modifications. The apparent variability in histone modifications among plants might be increased by technical variation introduced in sample processing during epigenetic analyses. Thus, to detect true variations in epigenetic histone patterns associated with given factors, the basal variability among samples that is not associated with them must be estimated. To improve knowledge of relative contribution of biological and technical variation, mass spectrometry was used to examine histone modification patterns (acetylation and methylation) among Arabidopsis thaliana plants of ecotypes Columbia 0 (Col-0) and Wassilewskija (Ws) homogenized by two techniques (grinding in a cryomill or with a mortar and pestle). We found little difference in histone modification profiles between the ecotypes. However, in comparison of the biological and technical components of variability, we found consistently higher inter-individual variability in histone mark levels among Ws plants than among Col-0 plants (grown from seeds collected either from single plants or sets of plants). Thus, more replicates of Ws would be needed for rigorous analysis of epigenetic marks. Regarding technical variability, the cryomill introduced detectably more heterogeneity in the data than the mortar and pestle treatment, but mass spectrometric analyses had minor apparent effects. Our study shows that it is essential to consider inter-sample variance and estimate suitable numbers of biological replicates for statistical analysis for each studied organism when investigating changes in epigenetic histone profiles.
Structural modification of polysaccharides: A biochemical-genetic approach
NASA Technical Reports Server (NTRS)
Kern, Roger G.; Petersen, Gene R.
1991-01-01
Polysaccharides have a wide range of industrial and biomedical applications. An industry trend is underway towards the increased use of bacteria to produce polysaccharides. Long term goals of this work are the adaptation and enhancement of saccharide properties for electronic and optic applications. In this report we illustrate the application of enzyme-bearing bacteriophage on strains of the enteric bacterium Klebsiella pneumoniae, which produces a polysaccharide with the relatively rare rheological property of drag-reduction. This has resulted in the production of new polysaccharides with enhanced rheological properties. Our laboratory is developing techniques for processing and structurally modifying bacterial polysaccharides and oligosaccharides which comprise their basic polymeric repeat units. Our research has focused on bacteriophage which produce specific polysaccharide degrading enzymes. This has lead to the development of enzymes generated by bacteriophage as tools for polysaccharide modification and purification. These enzymes were used to efficiently convert the native material to uniform-sized high molecular weight polymers, or alternatively into high-purity oligosaccharides. Enzyme-bearing bacteriophage also serve as genetic selection tools for bacteria that produce new families of polysaccharides with modified structures.
A multitechnique evaluation of topical corticosteroid treatment.
Josse, G; Rouvrais, C; Mas, A; Haftek, M; Delalleau, A; Ferraq, Y; Ossant, F; George, J; Lagarde, J M; Schmitt, A M
2009-02-01
Corticosteroids are widely prescribed for systemic or local treatment of inflammatory autoimmune disorders. Long-term therapy is associated with side effects and causes cutaneous atrophy of the epidermis and the dermis. The present study aims to evaluate with several noninvasive techniques, the skin modifications observed during corticosteroids treatment. The potential of skin mechanical measurement and ultrasound radio frequency (RF) signal analysis are proposed as new measures more closely related to the functional impairments. Thirteen young healthy women volunteers had two applications per day on one arm of topical Clobetasol propionate 0.05% for 28 days, and they were followed for 28 days more. Skin modifications were studied by high-frequency ultrasound imaging, ultrasound RF signal analysis, optical coherence tomography and by the suction test. For all the techniques, a statistically significant change is observed with treatment. Large variations, around 30%, are observed for all techniques, but less for ultrasound imaging (10%). Dermis and epidermis thickness presented stable measurements on the nontreated zone. At the end of the study, measures returned to normal. The dynamic is mainly observed within the first 14 days of treatment and within the first 14 days after its cessation. Similar dynamics of skin modification during corticosteroid treatment was observed with very different techniques. Moreover, the potential of RF ultrasound analysis and mechanical skin measurement for characterizing skin structural and functional impairments has been evaluated.
Multi-shot PROPELLER for high-field preclinical MRI
Pandit, Prachi; Qi, Yi; Story, Jennifer; King, Kevin F.; Johnson, G. Allan
2012-01-01
With the development of numerous mouse models of cancer, there is a tremendous need for an appropriate imaging technique to study the disease evolution. High-field T2-weighted imaging using PROPELLER MRI meets this need. The 2-shot PROPELLER technique presented here, provides (a) high spatial resolution, (b) high contrast resolution, and (c) rapid and non-invasive imaging, which enables high-throughput, longitudinal studies in free-breathing mice. Unique data collection and reconstruction makes this method robust against motion artifacts. The 2-shot modification introduced here, retains more high-frequency information and provides higher SNR than conventional single-shot PROPELLER, making this sequence feasible at high-fields, where signal loss is rapid. Results are shown in a liver metastases model to demonstrate the utility of this technique in one of the more challenging regions of the mouse, which is the abdomen. PMID:20572138
Multishot PROPELLER for high-field preclinical MRI.
Pandit, Prachi; Qi, Yi; Story, Jennifer; King, Kevin F; Johnson, G Allan
2010-07-01
With the development of numerous mouse models of cancer, there is a tremendous need for an appropriate imaging technique to study the disease evolution. High-field T(2)-weighted imaging using PROPELLER (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) MRI meets this need. The two-shot PROPELLER technique presented here provides (a) high spatial resolution, (b) high contrast resolution, and (c) rapid and noninvasive imaging, which enables high-throughput, longitudinal studies in free-breathing mice. Unique data collection and reconstruction makes this method robust against motion artifacts. The two-shot modification introduced here retains more high-frequency information and provides higher signal-to-noise ratio than conventional single-shot PROPELLER, making this sequence feasible at high fields, where signal loss is rapid. Results are shown in a liver metastases model to demonstrate the utility of this technique in one of the more challenging regions of the mouse, which is the abdomen. (c) 2010 Wiley-Liss, Inc.
Waste Printed Circuit Board (PCB) Recycling Techniques.
Ning, Chao; Lin, Carol Sze Ki; Hui, David Chi Wai; McKay, Gordon
2017-04-01
With the development of technologies and the change of consumer attitudes, the amount of waste electrical and electronic equipment (WEEE) is increasing annually. As the core part of WEEE, the waste printed circuit board (WPCB) is a dangerous waste but at the same time a rich resource for various kinds of materials. In this work, various WPCB treatment methods as well as WPCB recycling techniques divided into direct treatment (landfill and incineration), primitive recycling technology (pyrometallurgy, hydrometallurgy, biometallurgy and primitive full recovery of NMF-non metallic fraction), and advanced recycling technology (mechanical separation, direct use and modification of NMF) are reviewed and analyzed based on their advantages and disadvantages. Also, the evaluation criteria are discussed including economic, environmental, and gate-to-market ability. This review indicates the future research direction of WPCB recycling should focus on a combination of several techniques or in series recycling to maximize the benefits of process.
Single-molecule imaging of cytoplasmic dynein in vivo.
Ananthanarayanan, Vaishnavi; Tolić, Iva M
2015-01-01
While early fluorescence microscopy experiments employing fluorescent probes afforded snapshots of the cell, the power of live-cell microscopy is required to understand complex dynamics in biological processes. The first successful cloning of green fluorescent protein in the 1990s paved the way for development of approaches that we now utilize for visualization in a living cell. In this chapter, we discuss a technique to observe fluorescently tagged single molecules in fission yeast. With a few simple modifications to the established total internal reflection fluorescence microscopy, cytoplasmic dynein molecules in the cytoplasm and on the microtubules can be visualized and their intracellular dynamics can be studied. We illustrate a technique to study motor behavior, which is not apparent in conventional ensemble studies of motors. In general, this technique can be employed to study single-molecule dynamics of fluorescently tagged proteins in the cell interior. Copyright © 2015 Elsevier Inc. All rights reserved.
Siegert, Ralf
2004-11-01
Many techniques have been described for the correction of protruding ears. Most of them concentrate on correcting the form and position of auricular cartilage. The lobule is a soft tissue structure. Skin resections of its posterior surface have been propagated for the correction of its position; however, these cause tension on the wound and might increase the already relatively high risk for the development of keloids. We have modified the technique for correcting the protruding lobule for its exact positioning and minimizing the risk for relapse and keloids. Starting from the incision performed for the anthelix plasty, a subcutaneous pocket is prepared between the anterior and posterior sides of the lobule. Afterwards, the subcutaneous layer of the postlobular skin is adjusted and fixed to the cartilage of the conchal cavum with a special mattress suture. This technique is a refinement of otoplasty for bat ears. It is indicated for precise modification of form and position of protruding lobules.
The dynamics and control of large flexible space structures, 6
NASA Technical Reports Server (NTRS)
Bainum, P. M.
1983-01-01
The controls analysis based on a truncated finite element model of the 122m. Hoop/Column Antenna System focuses on an analysis of the controllability as well as the synthesis of control laws. Graph theoretic techniques are employed to consider controllability for different combinations of number and locations of actuators. Control law synthesis is based on an application of the linear regulator theory as well as pole placement techniques. Placement of an actuator on the hoop can result in a noticeable improvement in the transient characteristics. The problem of orientation and shape control of an orbiting flexible beam, previously examined, is now extended to include the influence of solar radiation environmental forces. For extremely flexible thin structures modification of control laws may be required and techniques for accomplishing this are explained. Effects of environmental torques are also included in previously developed models of orbiting flexible thin platforms.
NASA Technical Reports Server (NTRS)
Cacioppo, Elizabeth; Pusey, Marc Lee; Munson, Sibyl
1989-01-01
A simple, rapid method for determination of protein solubilities has been developed which is based upon maximization of the free solution volume to be brought into equilibrium. The tetragonal lysozome solubility diagram has been determined from pH 4.0 to 5.2 (0.1 M sodium acetate), 2-7 percent NaCl, 3-25 C, and portions of the orthorhombic solubility diagram using this technique. Both tetragonal and orthorhombic solubilities were found to increase smoothly with decreasing salt concentration and increasing temperature; no retrograde solubilities were observed. Using column volumes of 75, 300, and 900 microliters, identical tetragonal lysozyme solubility diagrams were obtained. Chymotrypsinogen solubilities have also been determined using this apparatus, being retrograde over the temperature range tested. It is noted that the primary limiting factor in reducing the crystalline volume is the minimum solution sample size needed to accurately quantitate the protein.
Evolution of instruments for harvest of the skin grafts
Ameer, Faisal; Singh, Arun Kumar; Kumar, Sandeep
2013-01-01
Background: The harvest of autologous skin graft is considered to be a fundamental skill of the plastic surgeon. The objective of this article is to provide an interesting account of the development of skin grafting instruments as we use them today in various plastic surgical procedures. Materials and Methods: The authors present the chronological evolution and modifications of the skin grafting knife, including those contributions not often cited in the literature, using articles sourced from MEDLINE, ancient manuscripts, original quotes, techniques and illustrations. Results: This article traces the evolution of instrumentation for harvest of skin grafts from free hand techniques to precise modern automated methods. Conclusions: Although skin grafting is one of the basic techniques used in reconstructive surgery yet harvest of a uniform graft of desired thickness poses a challenge. This article is dedicated to innovators who have devoted their lives and work to the advancement of the field of plastic surgery. PMID:23960303
Attentional bias modification for addictive behaviors: clinical implications.
Cox, W Miles; Fadardi, Javad S; Intriligator, James M; Klinger, Eric
2014-06-01
When a person has a goal of drinking alcohol or using another addictive substance, the person appears to be automatically distracted by stimuli related to the goal. Because the attentional bias might propel the person to use the substance, an intervention might help modify it. In this article, we discuss techniques that have been developed to help people overcome their attentional bias for alcohol, smoking-related stimuli, drugs, or unhealthy food. We also discuss how these techniques are being adapted for use on mobile devices. The latter would allow people with an addictive behavior to use the attentional training in privacy and as frequently as needed. The attentional training techniques discussed here appear to have several advantages. They are inexpensive, can be fun to use, and have flexibility in when, where, and how often they are used. The evidence so far also suggests that they are effective.
Stankevich, Ksenia S; Gudima, Alexandru; Filimonov, Victor D; Klüter, Harald; Mamontova, Evgeniya M; Tverdokhlebov, Sergei I; Kzhyshkowska, Julia
2015-06-01
Polylactic acid (PLA) based implants can cause inflammatory complications. Macrophages are key innate immune cells that control inflammation. To provide higher biocompatibility of PLA-based implants with local innate immune cells their surface properties have to be improved. In our study surface modification technique for high-molecular PLA (MW=1,646,600g/mol) based biomaterials was originally developed and successfully applied. Optimal modification conditions were determined. Treatment of PLA films with toluene/ethanol=3/7 mixture for 10min with subsequent exposure in 0.001M brilliant green dye (BGD) solution allows to entrap approximately 10(-9)mol/cm(2) model biomolecules. The modified PLA film surface was characterized by optical microscopy, SERS, FT-IR, UV and TG/DTA/DSC analysis. Tensile strain of modified films was determined as well. The effect of PLA films modified with BGD on the inflammatory reactions of primary human monocyte-derived macrophages was investigated. We developed in vitro test-system by differentiating primary monocyte-derived macrophages on a coating material. Type 1 and type 2 inflammatory cytokines (TNFα, CCL18) secretion and histological biomarkers (CD206, stabilin-1) expression were analyzed by ELISA and confocal microscopy respectively. BGD-modified materials have improved thermal stability and good mechanical properties. However, BGD modifications induced additional donor-specific inflammatory reactions and suppressed tolerogenic phenotype of macrophages. Therefore, our test-system successfully demonstrated specific immunomodulatory effects of original and modified PLA-based biomaterials, and can be further applied for the examination of improved coatings for implants and identification of patient-specific reactions to implants. Copyright © 2015. Published by Elsevier B.V.
ERIC Educational Resources Information Center
Comiskey, Vincent P.; And Others
Provided are some of the guidelines used in the Village School Behavior Modification Program for children with behavior problems in Bergen County, New Jersey. Included are definitions of the terms "emotionally disturbed" and "socially maladjusted", descriptions of some behavior modification techniques used, copies of forms and…
NASA Astrophysics Data System (ADS)
Kaiser, J.; Novotný, K.; Hrdlička, A.; Malina, R.; Novotný, J.; Prochazka, D.; Petrilak, M.; Krajcarová, L.; Vítková, G.; Kučerová, P.
2010-12-01
Here we report on the recent developments and upgrades of our Laser-Induced Breakdown Spectroscopy setups and their different modification for high-resolution mapping. Mapping capabilities of Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry are compared. The applied improvements as an autofocus algorithm, together with the realization of double-pulse LIBS or combination of LIBS by Laser-Induced Fluorescence Spectroscopy (LIFS) with technique are detailed. The signal enhancement obtained by double-pulse approach is demonstrated. The state of the art on development of portable remote LIBS apparatus is also presented.
Aerospace Environmental Technology Conference: Exectutive summary
NASA Technical Reports Server (NTRS)
Whitaker, A. F. (Editor)
1995-01-01
The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The papers from this conference are being published in a separate volume as NASA CP-3298.
Rapid prototyping and AI programming environments applied to payload modeling
NASA Technical Reports Server (NTRS)
Carnahan, Richard S., Jr.; Mendler, Andrew P.
1987-01-01
This effort focused on using artificial intelligence (AI) programming environments and rapid prototyping to aid in both space flight manned and unmanned payload simulation and training. Significant problems addressed are the large amount of development time required to design and implement just one of these payload simulations and the relative inflexibility of the resulting model to accepting future modification. Results of this effort have suggested that both rapid prototyping and AI programming environments can significantly reduce development time and cost when applied to the domain of payload modeling for crew training. The techniques employed are applicable to a variety of domains where models or simulations are required.
Evolution of phage display technology: from discovery to application.
Rahbarnia, Leila; Farajnia, Safar; Babaei, Hossein; Majidi, Jafar; Veisi, Kamal; Ahmadzadeh, Vahideh; Akbari, Bahman
2017-03-01
Phage display technology as a selection-based system is an attractive method for evolution of new biological drugs. Unique ability of phage libraries for displaying proteins on bacteriophage surfaces enable them to make a major contribution in diverse fields of researches related to the diagnosis and therapy of diseases. One of the great challenges facing researchers is the modification of phage display technology and the development of new applications. This article reviews the molecular basis of phage display library, and summarizes the novel and specific applications of this technique in the field of biological drugs development including therapeutic antibodies, peptides, vaccines, and catalytic antibodies.
Posttranscriptional modifications in the A-loop of 23S rRNAs from selected archaea and eubacteria.
Hansen, M A; Kirpekar, F; Ritterbusch, W; Vester, B
2002-02-01
Posttranscriptional modifications were mapped in helices 90-92 of 23S rRNA from the following phylogenetically diverse organisms: Haloarcula marismortui, Sulfolobus acidocaldarius, Bacillus subtilis, and Bacillus stearothermophilus. Helix 92 is a component of the ribosomal A-site, which contacts the aminoacyl-tRNA during protein synthesis, implying that posttranscriptional modifications in helices 90-92 may be important for ribosome function. RNA fragments were isolated from 23S rRNA by site-directed RNase H digestion. A novel method of mapping modifications by analysis of short, nucleotide-specific, RNase digestion fragments with Matrix Assisted Laser Desorption/Ionization Mass Spectrometry (MALDI-MS) was utilized. The MALDI-MS data were complemented by two primer extension techniques using reverse transcriptase. One technique utilizes decreasing concentrations of deoxynucleotide triphosphates to map 2'-O-ribose methylations. In the other, the rRNA is chemically modified, followed by mild alkaline hydrolysis to map pseudouridines (psis). A total of 10 posttranscriptionally methylated nucleotides and 6 psis were detected in the five organisms. Eight of the methylated nucleotides and one psi have not been reported previously. The distribution of modified nucleotides and their locations on the surface of the ribosomal peptidyl transferase cleft suggests functional importance.
NASA Astrophysics Data System (ADS)
Mant, Jenny; Janes, Victoria; Terrell, Robert; Allen, Deonie; Arthur, Scott; Yeakley, Alan; Morse, Jennifer; Holman, Ian
2015-04-01
Outfalls represent points of discharge to a river and often contain pollutants from urban runoff, such as heavy metals. Additionally, erosion around the outfall site results in increased sediment generation and the release of associated pollutants. Water quality impacts from heavy metals pose risks to the river ecosystem (e.g. toxicity to aquatic habitats). Restoration techniques including establishment of swales, and the re-vegetation and reinforcement of channel banks aim to decrease outfall flow velocities resulting in deposition of pollutants and removal through plant uptake. Within this study the benefits of river restoration techniques for the removal of contaminants associated with outfalls have been quantified within Johnson Creek, Portland, USA as part of the EPSRC funded Blue-Green Cities project. The project aims to develop new strategies for protecting hydrological and ecological values of urban landscapes. A range of outfalls have been selected which span restored and un-restored channel reaches, a variety of upstream land-uses, and both direct and set-back outfalls. River Habitat Surveys were conducted at each of the sites to assess the level of channel modification within the reach. Sediment samples were taken at the outfall location, upstream, and downstream of outfalls for analysis of metals including Nickel, Lead, Zinc, Copper, Iron and Magnesium. These were used to assess the impact of the level of modification at individual sites, and to compare the influence of direct and set-back outfalls. Concentrations of all metals in the sediments found at outfalls generally increased with the level of modification at the site. Sediment in restored sites had lower metal concentrations both at the outfall and downstream compared to unrestored sites, indicating the benefit of these techniques to facilitate the effective removal of pollutants by trapping of sediment and uptake of contaminants by vegetation. However, the impact of restoration measures varied between metal types. Restored sites also showed lower variability in metal concentrations than un-restored sites, which is linked to greater bank stability and hence lower bank erosion rates within restored sites as eroding banks were noted to be a source of metal contaminants. The success of pollutant removal by set-back outfalls was varied due to additional factors including the distance between the set-back outfall and the main channel, vegetation type, density and age. The study highlights the ability of restoration techniques to reduce metal contaminant concentrations at outfalls, and provides an indication of the potential benefits from wider application of similar techniques.
Pulsating potentiometric titration technique for assay of dissolved oxygen in water at trace level.
Sahoo, P; Ananthanarayanan, R; Malathi, N; Rajiniganth, M P; Murali, N; Swaminathan, P
2010-06-11
A simple but high performance potentiometric titration technique using pulsating sensors has been developed for assay of dissolved oxygen (DO) in water samples down to 10.0 microg L(-1) levels. The technique involves Winkler titration chemistry, commonly used for determination of dissolved oxygen in water at mg L(-1) levels, with modification in methodology for accurate detection of end point even at 10.0 microg L(-1) levels DO present in the sample. An indigenously built sampling cum pretreatment vessel has been deployed for collection and chemical fixing of dissolved oxygen in water samples from flowing water line without exposure to air. A potentiometric titration facility using pulsating sensors developed in-house is used to carry out titration. The power of the titration technique has been realised in estimation of very dilute solution of iodine equivalent to 10 microg L(-1) O(2). Finally, several water samples containing dissolved oxygen from mg L(-1) to microg L(-1) levels were successfully analysed with excellent reproducibility using this new technique. The precision in measurement of DO in water at 10 microg L(-1) O(2) level is 0.14 (n=5), RSD: 1.4%. Probably for the first time a potentiometric titration technique has been successfully deployed for assay of dissolved oxygen in water samples at 10 microg L(-1) levels. Copyright 2010 Elsevier B.V. All rights reserved.
A modification of incisionless otoplasty for correcting the prominent ear deformity.
Haytoglu, Suheyl; Haytoglu, Tahir Gokhan; Yildirim, Ilhami; Arikan, Osman Kursat
2015-11-01
This article describes a modification of the incisionless otoplasty. We investigated the complication rates, recurrence risks, and patient satisfaction with this modified procedure. In total, 26 patients (49 ears) complaining of prominent ear were operated on. Auriculocephalic distances were measured at three different levels, pre-operatively, at the end of the surgery, and at 4 weeks and 6 months after surgery to evaluate the efficacy of the technique. Patient satisfaction was evaluated using a visual analog scale and the global aesthetic improvement scale was applied by an independent non-participating plastic surgeon at 6 months after the surgery. The mean loss of medialization was ~1 mm at 4 weeks after surgery and 2 mm at 6 months after surgery for all levels. According to visual analog scale, patient or parent satisfaction increased significantly. The global aesthetic improvement scale rated the patients as 93.9% "improved" and 6.1% as "no change." No rating was "worse." There are many advantages of this technique. The operation is not time-consuming, does not require a dressing, and it can be performed in adults with local anesthesia under office conditions, with no need for hospitalization. After the operation, patients can return to their daily activities immediately. It is associated with a low complication rate and high patient satisfaction. This technique is a good option for otoplasty in patients with isolated, inadequate development of anti-helical ridge, and with soft auricular cartilage.
Transfusion risks and transfusion-related pro-inflammatory responses.
Despotis, George John; Zhang, Lini; Lublin, Douglas M
2007-02-01
Despite improvements in blood screening and administration techniques, serious adverse events related to transfusion continue to occur, albeit at a much lower incidence. In addition to the development and implementation of new screening and blood purification/modification techniques and implementation of an optimal blood management program, the incidence and consequences of transfusion reactions can be reduced by a basic understanding of transfusion-related complications. Although acute hemolytic transfusion reactions, transfusion-associated anaphylaxis and sepsis, and transfusion-associated acute lung injury occur infrequently, diligence in administration of blood and monitoring for development of respective signs/symptoms can minimize the severity of these potentially life-threatening complications. In addition, emerging blood-banking techniques such as psoralen-UV inactivation of pathogens and use of patient identification systems may attenuate the incidence of adverse events related to transfusion. With respect to optimizing blood management by means of an effective blood management program involving pharmacologic and nonpharmacologic strategies, the ability to reduce use of blood products and to decrease operative time or re-exploration rates has important implications for disease prevention, blood inventory and costs, and overall health care costs.
Kamsuwan, Tanutporn; Praserthdam, Piyasan; Jongsomjit, Bunjerd
2017-01-01
In the present study, the catalytic dehydration of ethanol over H-beta zeolite (HBZ) catalyst with ruthenium (Ru-HBZ) and platinum (Pt-HBZ) modification was investigated. Upon the reaction temperature between 200 and 400°C, it revealed that ethanol conversion and ethylene selectivity increased with increasing temperature for both Ru and Pt modification. At lower temperature (200 to 250°C), diethyl ether (DEE) was the major product. It was found that Ru and Pt modification on HBZ catalyst can result in increased DEE yield at low reaction temperature due to increased ethanol conversion without a significant change in DEE selectivity. By comparing the DEE yield of all catalysts in this study, the Ru-HBZ catalyst apparently exhibited the highest DEE yield (ca. 47%) at 250°C. However, at temperature from 350 to 400°C, the effect of Ru and Pt was less pronounced on ethylene yield. With various characterization techniques, the effects of Ru and Pt modification on HBZ catalyst were elucidated. It revealed that Ru and Pt were present in the highly dispersed forms and well distributed in the catalyst granules. It appeared that the weak acid sites measured by NH 3 temperature-programmed desorption technique also decreased with Ru and Pt promotion. Thus, the increased DEE yields with the Ru and Pt modification can be attributed to the presence of optimal weak acid sites leading to increased intrinsic activity of the catalysts. It can be concluded that the modification of Ru and Pt on HBZ catalyst can improve the DEE yields by ca. 10%.
NASA Astrophysics Data System (ADS)
Zhao, Rui; Zhang, Sijie; Liu, Jie; Gu, Junjie
2015-12-01
Lithium ion (Li-ion) battery has emerged as an important power source for portable devices and electric vehicles due to its superiority over other energy storage technologies. A mild temperature variation as well as a proper operating temperature range are essential for a Li-ion battery to perform soundly and have a long service life. In this review paper, the heat generation and dissipation of Li-ion battery are firstly analyzed based on the energy conservation equations, followed by an examination of the hazardous effects of an above normal operating temperature. Then, advanced techniques in respect of electrode modification and systematic battery thermal management are inspected in detail as solutions in terms of reducing internal heat production and accelerating external heat dissipation, respectively. Specifically, variable parameters like electrode thickness and particle size of active material, along with optimization methods such as coating, doping, and adding conductive media are discussed in the electrode modification section, while the current development in air cooling, liquid cooling, heat pipe cooling, and phase change material cooling systems are reviewed in the thermal management part as different ways to improve the thermal performance of Li-ion batteries.
Modified silicas with different structure of grafted methylphenylsiloxane layer
NASA Astrophysics Data System (ADS)
Bolbukh, Yuliia; Terpiłowski, Konrad; Kozakevych, Roman; Sternik, Dariusz; Deryło-Marczewska, Anna; Tertykh, Valentin
2016-06-01
The method of a chemical assembly of the surface polymeric layer with high contents of the modifying agent was developed. Powders of nanodispersed silica with chemisorbed polymethylphenylsiloxane (PMPS) were synthesized by solvent-free chemical assembly technique with a dimethyl carbonate (DMC) as scission agent. Samples were characterized using FTIR spectroscopy, transmission electron microscopy (TEM), atomic force microscopy (AFM), and elemental analysis (CHN analysis). Coating microstructure, morphology, and hydrophilic-hydrophobic properties of nanoparticles were estimated. The results indicate a significant effect of the PMPS/DMC ratio at each modification stage on hydrophobic properties of modified silicas. Modification with a similar composition of the PMPS/DMC mixture, even with different polymer amount at each stage, provides the worst hydrophobicity. Results suggest that the highest hydrophobicity (contact angle θ = 135°-140°) is achieved in the case when silica modified with the PMPS/DMC mixture using multistage approach that providing a formation of the monomolecular layer of polysiloxane at the first modification step. The characteristics of surface structure were interpreted in terms of density of polymer-silica bonds at the interfaces that, usually, are reduced for modified surfaces, in a coupling with conformation model that accented the shape of chains (arch- and console-like) adsorbed on solid surfaces.
NASA Technical Reports Server (NTRS)
Johns, Albert L.; Flood, Joseph D.; Strock, Thomas W.; Amuedo, Kurt C.
1988-01-01
Advanced Short Takeoff/Vertical Landing (STOVL) aircraft capable of operating from remote sites, damaged runways, and small air capable ships are being pursued for deployment around the turn of the century. To achieve this goal, it is important that the technologies critical to this unique class of aircraft be developed. Recognizing this need, NASA Lewis Research Center, McDonnell Douglas Aircraft, and DARPA defined a cooperative program for testing in the NASA Lewis 9- by 15-Foot Low Speed Wind Tunnel (LSWT) to establish a database for hot gas ingestion, one of the technologies critical to STOVL. Results from a test program are presented along with a discussion of the facility modifications allowing this type of testing at model scale. These modifications to the tunnel include a novel ground plane, an elaborate model support which included 4 degrees of freedom, heated high pressure air for nozzle flow, a suction system exhaust for inlet flow, and tunnel sidewall modifications. Several flow visualization techniques were employed including water mist in the nozzle flows and tufts on the ground plane. Headwind (free-stream) velocity was varied from 8 to 23 knots.
The Design and Development of Fluorescent Nano-Optodes for in Vivo Glucose Monitoring
Balaconis, Mary K.; Billingsley, Kelvin; Dubach, J. Matthew; Cash, Kevin J.; Clark, Heather A.
2011-01-01
Background The advent of fluorescent nanosensors has enabled intracellular monitoring of several physiological analytes, which was previously not possible with molecular dyes or other invasive techniques. We have extended the capability of these sensors to include the detection of small molecules with the development of glucose-sensitive nano-optodes. Herein, we discuss the design and development of glucose-sensitive nano-optodes, which have been proven functional both in vitro and in vivo. Methods Throughout the design process, each of the sensor formulations was evaluated based on their response to changes in glucose levels. The percent change in signal, sensor reversibility, and the overall fluorescence intensity were the specific parameters used to assess each formulation. Results A hydrophobic boronic acid was selected that yielded a fully reversible fluorescence response to glucose in accordance with the sensor mechanism. The change in fluorescence signal in response to glucose was approximately 11%. The use of different additives or chromophores did not improve the response; however, modifications to the plasticized polymeric membrane extended sensor lifetime. Conclusions Sensors were developed that yielded a dynamic response to glucose and through further modification of the components, sensor lifetime was improved. By following specific design criteria for the macrosensors, the sensors were miniaturized into nano-optodes that track changes in glucose levels in vivo. PMID:21303627
The design and development of fluorescent nano-optodes for in vivo glucose monitoring.
Balaconis, Mary K; Billingsley, Kelvin; Dubach, Matthew J; Cash, Kevin J; Clark, Heather A
2011-01-01
The advent of fluorescent nanosensors has enabled intracellular monitoring of several physiological analytes, which was previously not possible with molecular dyes or other invasive techniques. We have extended the capability of these sensors to include the detection of small molecules with the development of glucose-sensitive nano-optodes. Herein, we discuss the design and development of glucose-sensitive nano-optodes, which have been proven functional both in vitro and in vivo. Throughout the design process, each of the sensor formulations was evaluated based on their response to changes in glucose levels. The percent change in signal, sensor reversibility, and the overall fluorescence intensity were the specific parameters used to assess each formulation. A hydrophobic boronic acid was selected that yielded a fully reversible fluorescence response to glucose in accordance with the sensor mechanism. The change in fluorescence signal in response to glucose was approximately 11%. The use of different additives or chromophores did not improve the response; however, modifications to the plasticized polymeric membrane extended sensor lifetime. Sensors were developed that yielded a dynamic response to glucose and through further modification of the components, sensor lifetime was improved. By following specific design criteria for the macrosensors, the sensors were miniaturized into nano-optodes that track changes in glucose levels in vivo. © 2010 Diabetes Technology Society.
Gel-based methods in redox proteomics.
Charles, Rebecca; Jayawardhana, Tamani; Eaton, Philip
2014-02-01
The key to understanding the full significance of oxidants in health and disease is the development of tools and methods that allow the study of proteins that sense and transduce changes in cellular redox. Oxidant-reactive deprotonated thiols commonly operate as redox sensors in proteins and a variety of methods have been developed that allow us to monitor their oxidative modification. This outline review specifically focuses on gel-based methods used to detect, quantify and identify protein thiol oxidative modifications. The techniques we discuss fall into one of two broad categories. Firstly, methods that allow oxidation of thiols in specific proteins or the global cellular pool to be monitored are discussed. These typically utilise thiol-labelling reagents that add a reporter moiety (e.g. affinity tag, fluorophore, chromophore), in which loss of labelling signifies oxidation. Secondly, we outline methods that allow specific thiol oxidation states of proteins (e.g. S-sulfenylation, S-nitrosylation, S-thionylation and interprotein disulfide bond formation) to be investigated. A variety of different gel-based methods for identifying thiol proteins that are sensitive to oxidative modifications have been developed. These methods can aid the detection and quantification of thiol redox state, as well as identifying the sensor protein. By understanding how cellular redox is sensed and transduced to a functional effect by protein thiol redox sensors, this will help us better appreciate the role of oxidants in health and disease. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn. Copyright © 2013 Elsevier B.V. All rights reserved.
Alternative welding reconditioning solutions without post welding heat treatment of pressure vessel
NASA Astrophysics Data System (ADS)
Cicic, D. T.; Rontescu, C.; Bogatu, A. M.; Dijmărescu, M. C.
2017-08-01
In pressure vessels, working on high temperature and high pressure may appear some defects, cracks for example, which may lead to failure in operation. When these nonconformities are identified, after certain examination, testing and result interpretation, the decision taken is to repair or to replace the deteriorate component. In the current legislation it’s stipulated that any repair, alteration or modification to an item of pressurised equipment that was originally post-weld heat treated after welding (PWHT) should be post-weld heat treated again after repair, requirement that cannot always be respected. For that reason, worldwide, there were developed various welding repair techniques without PWHT, among we find the Half Bead Technique (HBT) and Controlled Deposition Technique (CDT). The paper presents the experimental results obtained by applying the welding reconditioning techniques HBT and CDT in order to restore as quickly as possible the pressure vessels made of 13CrMo4-5. The effects of these techniques upon the heat affected zone are analysed, the graphics of the hardness variation are drawn and the resulted structures are compared in the two cases.
Approximate analytical relationships for linear optimal aeroelastic flight control laws
NASA Astrophysics Data System (ADS)
Kassem, Ayman Hamdy
1998-09-01
This dissertation introduces new methods to uncover functional relationships between design parameters of a contemporary control design technique and the resulting closed-loop properties. Three new methods are developed for generating such relationships through analytical expressions: the Direct Eigen-Based Technique, the Order of Magnitude Technique, and the Cost Function Imbedding Technique. Efforts concentrated on the linear-quadratic state-feedback control-design technique applied to an aeroelastic flight control task. For this specific application, simple and accurate analytical expressions for the closed-loop eigenvalues and zeros in terms of basic parameters such as stability and control derivatives, structural vibration damping and natural frequency, and cost function weights are generated. These expressions explicitly indicate how the weights augment the short period and aeroelastic modes, as well as the closed-loop zeros, and by what physical mechanism. The analytical expressions are used to address topics such as damping, nonminimum phase behavior, stability, and performance with robustness considerations, and design modifications. This type of knowledge is invaluable to the flight control designer and would be more difficult to formulate when obtained from numerical-based sensitivity analysis.
Is Mitochondrial Donation Germ-Line Gene Therapy? Classifications and Ethical Implications.
Newson, Ainsley J; Wrigley, Anthony
2017-01-01
The classification of techniques used in mitochondrial donation, including their role as purported germ-line gene therapies, is far from clear. These techniques exhibit characteristics typical of a variety of classifications that have been used in both scientific and bioethics scholarship. This raises two connected questions, which we address in this paper: (i) how should we classify mitochondrial donation techniques?; and (ii) what ethical implications surround such a classification? First, we outline how methods of genetic intervention, such as germ-line gene therapy, are typically defined or classified. We then consider whether techniques of mitochondrial donation fit into these, whether they might do so with some refinement of these categories, or whether they require some other approach to classification. To answer the second question, we discuss the relationship between classification and several key ethical issues arising from mitochondrial donation. We conclude that the properties characteristic of mitochondrial inheritance mean that most mitochondrial donation techniques belong to a new sub-class of genetic modification, which we call 'conditionally inheritable genomic modification' (CIGM). © 2017 John Wiley & Sons Ltd.
Surface Modification for Improved Design and Functionality of Nanostructured Materials and Devices
NASA Astrophysics Data System (ADS)
Keiper, Timothy Keiper
Progress in nanotechnology is trending towards applications which require the integration of soft (organic or biological) and hard (semiconductor or metallic) materials. Many applications for functional nanomaterials are currently being explored, including chemical and biological sensors, flexible electronics, molecular electronics, etc., with researchers aiming to develop new paradigms of nanoelectronics through manipulation of the physical properties by surface treatments. This dissertation focuses on two surface modification techniques important for integration of hard and soft materials: thermal annealing and molecular modification of semiconductors. First, the effects of thermal annealing are investigated directly for their implication in the fundamental understanding of transparent conducting oxides with respect to low resistivity contacts for electronic and optoelectronic applications and the response to environmental stimuli for sensing applications. The second focus of this dissertation covers two aspects of the importance of molecular modification on semiconductor systems. The first of these is the formation of self-assembled monolayers in patterned arrays which leads explicitly to the directed self-assembly of nanostructures. The second aspect concerns the modification of the underlying magnetic properties of the preeminent dilute magnetic semiconductor, manganese-doped gallium arsenide. Tin oxide belongs to a class of materials known as transparent conducting oxides which have received extensive interest due to their sensitivity to environmental stimuli and their potential application in transparent and flexible electronics. Nanostructures composed of SnO2 have been demonstrated as an advantageous material for high performance, point-of-care nanoelectronic sensors, capable of detecting and distinguishing gaseous or biomolecular interactions on unprecedented fast timescales. Through bottom-up fabrication techniques, binary oxide nanobelts synthesized through catalyst-free physical vapor deposition are implemented in the field-effect transistor structure. We have discovered that conductivity is absent in as-grown devices. However, utilizing a process for thermal treatment in vacuum and oxygen environments is found to be instrumental in fabricating field-effect transistors with significant conductivity, up to five orders of magnitude above the as-grown devices, for field-effect transistor application. Further investigation by photoluminescence coupled with the annealing parameters reveals that the likely cause of conductance comes from the reduction of surface defect states in the material. Importantly, the annealed material maintains its response to an applied gate potential showing orders of magnitude switching from the 'off' to the 'on' state. In order to show the practical relevance of our improvements on the SnO2 material, we show our results for implementing the annealed material in biomolecular sensing experiments to detect the presence of streptavidin and Hepatitis C virus. Surface modification was carried out on oxide-free gallium arsenide (in some cases doped with manganese or zinc) through self-assembly of thiol molecules. First, we investigate the ability to pattern via two complementary micro- and nanopatterning techniques, microcontact printing (muCP) and dip-pen nanolithography (DPN). DPN is a unique lithography tool that allows drawing of arbitrary patterns with a molecular ink on a complementary substrate. It is extremely useful in integration of molecular inks within a pre-defined structure. Here, DPN was used to investigate the diffusion of organic molecules from a point source for both a moving and stationary tip on oxide-free GaAs. The diffusion can be calibrated so that intricate patterns down to tens of nanometers can be arbitrarily drawn on the surface. muCP, a less complicated method for large-scale arrayed patterning, is utilized to investigate the deposition of different thiolated molecular inks on GaAs and (Ga,Mn)As. The patterns deposited by muCP provide the template for directed self-assembly of gold nanoparticles. The systems based on these techniques can be extended to many substrate-molecule-nanostructure systems for an incredible variety of applications. Finally, the thiol-(Ga,Mn)As system is studied to determine the effects of molecular modification on the substrates' magnetic properties via modulation of the hole concentration in the wafer. The results for two molecules, one an electron donor and one an electron acceptor, show opposite trends for modulation of both the Curie temperature and the saturation magnetization. We suggest that nanopatterning of electron donor or electron acceptor molecules could lead to the development of reconfigurable nanomagnetic systems in (Ga,Mn)As with potential applications in molecular spintronics or magnetic memory.
Self-Modification Technique for the Control of Eating Behavior for the Visually Handicapped.
ERIC Educational Resources Information Center
Snoy, Mary T.; van Benten, Letitia
1978-01-01
A ten-week study was done of four visually handicapped overweight adolescents (ages 15-19 years) in a residential school to evaluate the efficacy of an operant conditioning technique designed to promote weight loss by altering eating habits. (Author/DLS)
Yao, Chang; Webster, Thomas J
2006-01-01
Anodization is a well-established surface modification technique that produces protective oxide layers on valve metals such as titanium. Many studies have used anodization to produce micro-porous titanium oxide films on implant surfaces for orthopedic applications. An additional hydrothermal treatment has also been used in conjunction with anodization to deposit hydroxyapatite on titanium surfaces; this is in contrast to using traditional plasma spray deposition techniques. Recently, the ability to create nanometer surface structures (e.g., nano-tubular) via anodization of titanium implants in fluorine solutions have intrigued investigators to fabricate nano-scale surface features that mimic the natural bone environment. This paper will present an overview of anodization techniques used to produce micro-porous titanium oxide structures and nano-tubular oxide structures, subsequent properties of these anodized titanium surfaces, and ultimately their in vitro as well as in vivo biological responses pertinent for orthopedic applications. Lastly, this review will emphasize why anodized titanium structures that have nanometer surface features enhance bone forming cell functions.
Eckstein, Chris; Acosta, Laura K; Pol, Laura; Xifré-Pérez, Elisabet; Pallares, Josep; Ferré-Borrull, Josep; Marsal, Lluis F
2018-03-28
The fluid imbibition-coupled laser interferometry (FICLI) technique has been applied to detect and quantify surface changes and pore dimension variations in nanoporous anodic alumina (NAA) structures. FICLI is a noninvasive optical technique that permits the determination of the NAA average pore radius with high accuracy. In this work, the technique is applied after each step of different surface modification paths of the NAA pores: (i) electrostatic immobilization of bovine serum albumin (BSA), (ii) covalent attachment of streptavidin via (3-aminipropyl)-triethoxysilane and glutaraldehyde grafting, and (iii) immune complexation. Results show that BSA attachment can be detected as a reduction in estimated radius from FICLI with high accuracy and reproducibility. In the case of the covalent attachment of streptavidin, FICLI is able to recognize a multilayer formation of the silane and the protein. For immune complexation, the technique is able to detect different antibody-antigen bindings and distinguish different dynamics among different immune species.
Traction suture modification to tongue-in-groove caudal septoplasty.
Indeyeva, Y A; Lee, T S; Gordin, E; Chan, D; Ducic, Y
2018-02-01
Caudal septal deviation leads to unfavorable esthetic as well as functional effects on the nasal airway. A modification to the tongue-in-groove (TIG) technique to correct these caudal septal deformities is described. With placement of a temporary suspension suture to the caudal septum, manual traction is applied, assuring that the caudal septum remains in the midline position while it is being secured with multiple through-and-through, trans-columellar and trans-septal sutures. From 2003 to 2016, 148 patients underwent endonasal septoplasty using this modified technique, with excellent functional and cosmetic outcomes and a revision rate of 1.4%. This modified TIG technique replaces the periosteal suture that secures the caudal septum to the midline nasal crest in the original TIG technique. This simplifies the procedure and minimizes the risk of securing the caudal septum off-midline when used in endonasal septoplasty. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
mRNA Traffic Control Reviewed: N6-Methyladenosine (m6 A) Takes the Driver's Seat.
Visvanathan, Abhirami; Somasundaram, Kumaravel
2018-01-01
Messenger RNA is a flexible tool box that plays a key role in the dynamic regulation of gene expression. RNA modifications variegate the message conveyed by the mRNA. Similar to DNA and histone modifications, mRNA modifications are reversible and play a key role in the regulation of molecular events. Our understanding about the landscape of RNA modifications is still rudimentary in contrast to DNA and histone modifications. The major obstacle has been the lack of sensitive detection methods since they are non-editing events. However, with the advent of next-generation sequencing techniques, RNA modifications are being identified precisely at single nucleotide resolution. In recent years, methylation at the N6 position of adenine (m 6 A) has gained the attention of RNA biologists. The m 6 A modification has a set of writers (methylases), erasers (demethylases), and readers. Here, we provide a summary of interesting facts, conflicting findings, and recent advances in the technical and functional aspects of the m 6 A epitranscriptome. © 2017 WILEY Periodicals, Inc.
Detection of histone modifications in plant leaves.
Jaskiewicz, Michal; Peterhansel, Christoph; Conrath, Uwe
2011-09-23
Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles(1-2). H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues(1-2). These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.)(3-7). Here, we present a method for the reliable and sensitive detection of specific chromatin modifications on selected plant genes. The technique is based on the crosslinking of (modified) histones and DNA with formaldehyde(8,9), extraction and sonication of chromatin, chromatin immunoprecipitation (ChIP) with modification-specific antibodies(9,10), de-crosslinking of histone-DNA complexes, and gene-specific real-time quantitative PCR. The approach has proven useful for detecting specific histone modifications associated with C(4;) photosynthesis in maize(5,11) and systemic immunity in Arabidopsis(3).
Gani, Johan; Chee, Justin
2016-01-01
Purpose To present a novel modification of surgical technique to treat female urethral stricture (FUS) by a vaginal-sparing ventral buccal mucosal urethroplasty. Recurrent FUS represents an uncommon, though difficult clinical scenario to manage definitively. A variety of surgical techniques have been described to date, yet a lack of consensus on the optimal procedure persists. Materials and Methods We present a 51-year-old female with urethral stricture involving the entire urethra. Suspected etiology was iatrogenic from cystoscopy 17 years prior. Since then, the patient had undergone at least 25 formal urethral dilations and periods of self-dilation. In lithotomy position, the urethra was dilated to accommodate forceps, and ventral urethrotomy carried out sharply, exposing a bed of periurethral tissue. Buccal mucosa was harvested, and a ventral inlay technique facilitated by a nasal speculum, was used to place the graft from the proximal urethra/bladder neck to urethral meatus without a vaginal incision. Graft was sutured into place, and urethral Foley catheter inserted. Results The vaginal-sparing ventral buccal mucosal graft urethroplasty was deemed successful as of last follow-up. Flexible cystoscopy demonstrated patency of the repair at 6 months. At 10 months of follow-up, the patient was voiding well, with no urinary incontinence. No further interventions have been required. Conclusions This case describes a novel modification of surgical technique for performing buccal mucosal urethroplasty for FUS. By avoiding incision of the vaginal mucosa, benefits may include reduced: morbidity, urinary incontinence, and wound complications including urethro-vaginal fistula. PMID:27437540
Vishwakarma, Aruna Prashanth; Bondarde, Prashant Arjun; Patil, Sudha Bhimangouda; Dodamani, Arun Suresh; Vishwakarma, Prashanth Yachrappa; Mujawar, Shoeb A
2017-01-01
Dental fear is a common, essential, and inevitable emotion that appears as a response to the stressful situation, which raises children's anxiety level, resulting in reduced demand for pediatric dental care. (1) To compare and evaluate the effectiveness of customized tell-play-do (TPD) technique with live modeling for behavior management of children. (2) To compare the behavioral modification techniques in managing the children during their dental visits. Ninety-eight children aged 5-7 years were enrolled in the study and randomly allocated into two groups. Phase I: first visit. Group I - children were conditioned to receive various dental procedures using live modeling followed by oral prophylaxis. Group II - TPD technique was introduced with customized playing dental objects followed by oral prophylaxis. Phase II: second visit. After 7 days interval, all the study subjects were subjected to rotary restorative treatment. Heart rate, Facial Image Scale (FIS), and Venham-6-point index were used before intervention, after intervention, and during dental procedure to quantify the anxious behavior. All 98 children after intervention underwent oral prophylaxis on first visit and rotary restorative treatment on second visit. The average pulse rate, FIS, and Venham scale scores were significantly lower among children who received TPD intervention when compared to those who received live modeling intervention. Unpaired t-test at 5% level of significance was considered as statistical significance. TPD is effective in reducing children's fear and anxiety about dental treatment, children enjoy playing with customized dental object. Thus, to promote adaptive behavior, TPD could be an alternate behavioral modification technique during pediatric dentistry.
Saafan, Tamer; Hu, James Yi; Mahfouz, Ahmed-Emad; Abdelaal, Abdelrahman
2018-01-01
True left-sided gallbladder (LSG) is a rare finding that may present with symptoms similar to those of a normally positioned gallbladder. Moreover, it may be missed by preoperative imaging studies such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), or endoscopic ultrasound. True left-sided gallbladder is a surgical challenge and surgical technique may need to be modified for the completion of laparoscopic cholecystectomy. In this case report, we present a case of true left-sided gallbladder that produced right-sided abdominal symptoms. Ultrasound of the abdomen failed to show the left-sided position of the gallbladder. MRI showed the gallbladder located to the left of the ligamentum teres underneath segment III of the liver. Intraoperatively, the gallbladder was grasped and retracted to the right under the falciform ligament and it was removed using classical right-sided ports with no modification to the technique. No complications were encountered intraoperatively or postoperatively. True LSG is a rare anomaly that may present with right-sided symptoms like normally positioned gallbladder. It may be missed in preoperative imaging studies and can be discovered only intraoperatively. Modification of laparoscopic ports, change in patient's position and/or surgeon's position, or conversion to open cholecystectomy may be needed for safe removal of the gallbladder. Classical technique of laparoscopic cholecystectomy is feasible for left-sided gallbladder. However, if the anatomy is not clear, modifications of the surgical technique may be necessary for the safe dissection of the gallbladder. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
Kucinska-Lipka, J; Gubanska, I; Janik, H; Sienkiewicz, M
2015-01-01
Electrospinning is a unique technique, which provides forming of polymeric scaffolds for soft tissue engineering, which include tissue scaffolds for soft tissues of the cardiovascular system. Such artificial soft tissues of the cardiovascular system may possess mechanical properties comparable to native vascular tissues. Electrospinning technique gives the opportunity to form fibres with nm- to μm-scale in diameter. The arrangement of obtained fibres and their surface determine the biocompatibility of the scaffolds. Polyurethanes (PUs) are being commonly used as a prosthesis of cardiovascular soft tissues due to their excellent biocompatibility, non-toxicity, elasticity and mechanical properties. PUs also possess fine spinning properties. The combination of a variety of PU properties with an electrospinning technique, conducted at the well tailored conditions, gives unlimited possibilities of forming novel polyurethane materials suitable for soft tissue scaffolds applied in cardiovascular tissue engineering. This paper can help researches to gain more widespread and deeper understanding of designing electrospinable PU materials, which may be used as cardiovascular soft tissue scaffolds. In this paper we focus on reagents used in PU synthesis designed to increase PU biocompatibility (polyols) and biodegradability (isocyanates). We also describe suggested surface modifications of electrospun PUs, and the direct influence of surface wettability on providing enhanced biocompatibility of scaffolds. We indicate a great influence of electrospinning parameters (voltage, flow rate, working distance) and used solvents (mostly DMF, THF and HFIP) on fibre alignment and diameter - what impacts the biocompatibility and hemocompatibility of such electrospun PU scaffolds. Moreover, we present PU modifications with natural polymers with novel approach applied in electrospinning of PU scaffolds. This work may contribute with further developing of novel electrospun PUs, which may be applied as soft tissue scaffolds of the cardiovascular system. Copyright © 2014. Published by Elsevier B.V.
CRISPR-Cas9: Tool for Qualitative and Quantitative Plant Genome Editing
Noman, Ali; Aqeel, Muhammad; He, Shuilin
2016-01-01
Recent developments in genome editing techniques have aroused substantial excitement among agricultural scientists. These techniques offer new opportunities for developing improved plant lines with addition of important traits or removal of undesirable traits. Increased adoption of genome editing has been geared by swiftly developing Clustered regularly interspaced short palindromic repeats (CRISPR). This is appearing as driving force for innovative utilization in diverse branches of plant biology. CRISPR-Cas9 mediated genome editing is being used for rapid, easy and efficient alteration of genes among diverse plant species. With approximate completion of conceptual work about CRISPR-Cas9, plant scientists are applying this genome editing tool for crop attributes enhancement. The capability of this system for performing targeted and efficient modifications in genome sequence as well as gene expression will certainly spur novel developments not only in model plants but in crop and ornamental plants as well. Additionally, due to non-involvement of foreign DNA, this technique may help alleviating regulatory issues associated with genetically modified plants. We expect that prevailing challenges in plant science like genomic region manipulation, crop specific vectors etc. will be addressed along with sustained growth of this genome editing tool. In this review, recent progress of CRISPR-Cas9 technology in plants has been summarized and discussed. We reviewed significance of CRISPR-Cas9 for specific and non-traditional aspects of plant life. It also covers strengths of this technique in comparison with other genome editing techniques, e.g., Zinc finger nucleases, Transcription activator-like effector nucleases and potential challenges in coming decades have been described. PMID:27917188
NASA Astrophysics Data System (ADS)
Patil, Venkat P.; Gohatre, Umakant B.
2018-04-01
The technique of obtaining a wider field-of-view of an image to get high resolution integrated image is normally required for development of panorama of a photographic images or scene from a sequence of part of multiple views. There are various image stitching methods developed recently. For image stitching five basic steps are adopted stitching which are Feature detection and extraction, Image registration, computing homography, image warping and Blending. This paper provides review of some of the existing available image feature detection and extraction techniques and image stitching algorithms by categorizing them into several methods. For each category, the basic concepts are first described and later on the necessary modifications made to the fundamental concepts by different researchers are elaborated. This paper also highlights about the some of the fundamental techniques for the process of photographic image feature detection and extraction methods under various illumination conditions. The Importance of Image stitching is applicable in the various fields such as medical imaging, astrophotography and computer vision. For comparing performance evaluation of the techniques used for image features detection three methods are considered i.e. ORB, SURF, HESSIAN and time required for input images feature detection is measured. Results obtained finally concludes that for daylight condition, ORB algorithm found better due to the fact that less tome is required for more features extracted where as for images under night light condition it shows that SURF detector performs better than ORB/HESSIAN detectors.
Current modifications to totally laparoscopic "apron technique".
Dion, Yves-Marie; Thaveau, Fabien; Fearn, Shirley J
2003-08-01
Since our original description in 1997 of a totally laparoscopic technique for treatment of aortoiliac disease, this type of minimally invasive procedure has been used both in the United States and abroad. We describe improvements that should make this technique more easily reproducible. This modified procedure was offered to six patients, one of whom received a tube graft for treatment of aneurysm disease.
Ye, Sang-Ho; Jang, Yong-Seok; Yun, Yeo-Heung; Shankarraman, Venkat; Woolley, Joshua R.; Hong, Yi; Gamble, Lara J.; Ishihara, Kazuhiko; Wagner, William R.
2013-01-01
Siloxane functionalized phosphorylcholine (PC) or sulfobetaine (SB) macromolecules (PCSSi or SBSSi) were synthesized to act as surface modifying agents for degradable metallic surfaces to improve acute blood compatibility and slow initial corrosion rates. The macromolecules were synthesized using a thiol-ene radical photopolymerization technique and then utilized to modify magnesium (Mg) alloy (AZ31) surfaces via an anhydrous phase deposition of the silane functional groups. X-ray photoelectron spectroscopy surface analysis results indicated successful surface modification based on increased nitrogen and phosphorus or sulfur composition on the modified surfaces relative to unmodified AZ31. In vitro acute thrombogenicity assessment after ovine blood contact with the PCSSi and SBSSi modified surfaces showed a significant decrease in platelet deposition and bulk phase platelet activation compared with the control alloy surfaces. Potentiodynamic polarization and electrochemical impedance spectroscopy data obtained from electrochemical corrosion testing demonstrated increased corrosion resistance for PCSSi and SBSSi modified AZ31 versus unmodified surfaces. The developed coating technique using PCSSi or SBSSi showed promise in acutely reducing both the corrosion and thrombotic processes, which would be attractive for application to blood contacting devices, such as vascular stents, made from degradable Mg alloys. PMID:23705967
García Raya, Daniel; Madueño, Rafael; Blázquez, Manuel; Pineda, Teresa
2010-07-20
A characterization of the 1,8-octanedithiol (ODT) self-assembled monolayer (SAM) formed from a Triton X-100 lyotropic medium has been conducted by electrochemical techniques. It is found that an ODT layer of standing-up molecules is obtained at short modification time without removing oxygen from the medium. The electrochemical study shows that the ODT layer formed after 15 min of modification time has similar electron-transfer blocking properties to the layers formed from organic solvents at much longer modification times. On the basis of XPS data, it is demonstrated that the inability to bind gold nanoparticles (AuNPs) is due to the presence of extra ODT molecules either interdigited or on top of the layer. Treatment consisting of an acid washing step following the formation of the ODT-Au(111) SAM produces a layer that is able to attach AuNPs as demonstrated by electrochemical techniques and atomic force microscopy (AFM) images.
43 CFR 3931.50 - Exploration plan and plan of development modifications.
Code of Federal Regulations, 2014 CFR
2014-10-01
... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Exploration plan and plan of development... EXPLORATION AND LEASES Plans of Development and Exploration Plans § 3931.50 Exploration plan and plan of development modifications. (a) The operator or lessee may apply in writing to the BLM for modification of the...
43 CFR 3931.50 - Exploration plan and plan of development modifications.
Code of Federal Regulations, 2013 CFR
2013-10-01
... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Exploration plan and plan of development... EXPLORATION AND LEASES Plans of Development and Exploration Plans § 3931.50 Exploration plan and plan of development modifications. (a) The operator or lessee may apply in writing to the BLM for modification of the...
43 CFR 3931.50 - Exploration plan and plan of development modifications.
Code of Federal Regulations, 2011 CFR
2011-10-01
... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Exploration plan and plan of development... EXPLORATION AND LEASES Plans of Development and Exploration Plans § 3931.50 Exploration plan and plan of development modifications. (a) The operator or lessee may apply in writing to the BLM for modification of the...
43 CFR 3931.50 - Exploration plan and plan of development modifications.
Code of Federal Regulations, 2012 CFR
2012-10-01
... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Exploration plan and plan of development... EXPLORATION AND LEASES Plans of Development and Exploration Plans § 3931.50 Exploration plan and plan of development modifications. (a) The operator or lessee may apply in writing to the BLM for modification of the...
NASA Astrophysics Data System (ADS)
Kamiya, Hidehiro; Iijima, Motoyuki
2010-08-01
Inorganic nanoparticles are indispensable for science and technology as materials, pigments and cosmetics products. Improving the dispersion stability of nanoparticles in various liquids is essential for those applications. In this review, we discuss why it is difficult to control the stability of nanoparticles in liquids. We also overview the role of surface interaction between nanoparticles in their dispersion and characterization, e.g. by colloid probe atomic force microscopy (CP-AFM). Two types of surface modification concepts, post-synthesis and in situ modification, were investigated in many previous studies. Here, we focus on post-synthesis modification using adsorption of various kinds of polymer dispersants and surfactants on the particle surface, as well as surface chemical reactions of silane coupling agents. We discuss CP-AFM as a technique to analyze the surface interaction between nanoparticles and the effect of surface modification on the nanoparticle dispersion in liquids.
NASA Technical Reports Server (NTRS)
Huang, N. E.; Flood, W. A.; Brown, G. S.
1975-01-01
The feasibility of remote sensing of current flows in the ocean and the remote sensing of ocean currents by backscattering cross section techniques was studied. It was established that for capillary waves, small scale currents could be accurately measured through observation of wave kinematics. Drastic modifications of waves by changing currents were noted. The development of new methods for the measurement of capillary waves are discussed. Improvement methods to resolve data processing problems are suggested.
Mechanisms and dynamics of nuclear lamina-genome interactions.
Amendola, Mario; van Steensel, Bas
2014-06-01
The nuclear lamina (NL) interacts with the genomic DNA and is thought to influence chromosome organization and gene expression. Both DNA sequences and histone modifications are important for NL tethering of the genomic DNA. These interactions are dynamic in individual cells and can change during differentiation and development. Evidence is accumulating that the NL contributes to the repression of transcription. Advances in mapping, genome-editing and microscopy techniques are increasing our understanding of the molecular mechanisms involved in NL-genome interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.
Transient thermal modeling of the nonscanning ERBE detector
NASA Technical Reports Server (NTRS)
Mahan, J. R.
1983-01-01
A numerical model to predict the transient thermal response of the ERBE nonscanning wide field of view total radiometer channel was developed. The model, which uses Monte Carlo techniques to characterize the radiative component of heat transfer, is described and a listing of the computer program is provided. Application of the model to simulate the actual blackbody calibration procedure is discussed. The use of the model to establish a real time flight data interpretation strategy is recommended. Modification of the model to include a simulated Earth radiation source field and a filter dome is indicated.
Spacecraft configuration study for second generation mobile satellite system
NASA Technical Reports Server (NTRS)
Louie, M.; Vonstentzsch, W.; Zanella, F.; Hayes, R.; Mcgovern, F.; Tyner, R.
1985-01-01
A high power, high performance communicatons satellite bus being developed is designed to satisfy a broad range of multimission payload requirements in a cost effective manner and is compatible with both STS and expendable launchers. Results are presented of tradeoff studies conducted to optimize the second generation mobile satellite system for its mass, power, and physical size. Investigations of the 20-meter antenna configuration, transponder linearization techniques, needed spacecraft modifications, and spacecraft power, dissipation, mass, and physical size indicate that the advanced spacecraft bus is capable of supporting the required payload for the satellite.
An Extension of Holographic Moiré to Micromechanics
NASA Astrophysics Data System (ADS)
Sciammarella, C. A.; Sciammarella, F. M.
The electronic Holographic Moiré is an ideal tool for micromechanics studies. It does not require a modification of the surface by the introduction of a reference grating. This is of particular advantage when dealing with materials such as solid propellant grains whose chemical nature and surface finish makes the application of a reference grating very difficult. Traditional electronic Holographic Moiré presents some difficult problems when large magnifications are needed and large rigid body motion takes place. This paper presents developments that solves these problems and extends the application of the technique to micromechanics.
Radar studies related to the earth resources program. [remote sensing programs
NASA Technical Reports Server (NTRS)
Holtzman, J.
1972-01-01
The radar systems research discussed is directed toward achieving successful application of radar to remote sensing problems in such areas as geology, hydrology, agriculture, geography, forestry, and oceanography. Topics discussed include imaging radar and evaluation of its modification, study of digital processing for synthetic aperture system, digital simulation of synthetic aperture system, averaging techniques studies, ultrasonic modeling of panchromatic system, panchromatic radar/radar spectrometer development, measuring octave-bandwidth response of selected targets, scatterometer system analysis, and a model Fresnel-zone processor for synthetic aperture imagery.
Miller, Henry I
2010-01-01
The United Nations is a bastion of corruption, profligacy and incompetence that is a particular threat to the inhabitants of poor nations. Its policies, programs and agencies have made a growth industry of the unscientific regulation of important technologies-of which gene-splicing [also known as recombinant DNA technology or genetic modification (GM)] is only one. The UN's actions regularly defy scientific consensus and common sense, instead pandering to extremists. The result is vastly inflated research and development costs, less innovation, and diminished exploitation of superior techniques and products that could offer monumental humanitarian and economic benefits.
Capturing birds with mist nets: A review
Keyes, B.E.; Grue, C.E.
1982-01-01
Herein we have tried to provide a comprehensive review of mist-netting techniques suitable for both novice and experienced netters. General mist-netting procedures and modifications developed by netters for particular bird species and habitats are included. Factors which influence capture success, including site selection, net specifications and placement, weather, and time of day, are discussed. Guidelines are presented for the care of netted birds and the use of mist-net data in the study of bird communities. The advantages of the use of mist nets over other methods of capturing birds are also discussed.
NASA Astrophysics Data System (ADS)
Yoo, S.; Kalita, M. P.; Boyland, A. J.; Webb, A. S.; Standish, R. J.; Sahu, J. K.; Paul, M. C.; Das, S.; Bhadra, S. K.; Pal, M.
2010-09-01
We report efficient laser demonstration and spectroscopic characteristics of a Yb-doped Y 2O 3 (or Y 3Al 5O 12) nanoparticle silica fiber developed by conventional fiber fabrication technique. The spectroscopy study evidences modification in the environment of Yb ions by the Y 2O 3 nanoparticles. As a result, photodarkening induced loss is reduced by 20 times relative to Yb-doped aluminosilicate fibers. The fiber is suitable for power scaling with good laser slope efficiency of 79%.
The Nike-Black Brant V development program
NASA Technical Reports Server (NTRS)
Sevier, H.; Payne, B.; Ott, R.; Montag, W.
1976-01-01
The Nike-Black Brant V represents a combined U.S.-Canadian program to achieve a 40 percent increase in apogee performance over that of the unboosted BBV, with minimum component modification and no meaningful increase in flight environment levels. The process of achieving these objectives is described, in particular optimization of sustainer coast period and roll history, and the techniques used to ensure good stage separation. Details of the structural test program and subsequent successful vehicle proving flight are provided. Basic performance data are preented, with an indication of the further potential offered by Terrier boost.
The CRISPR/Cas Genome-Editing Tool: Application in Improvement of Crops
Khatodia, Surender; Bhatotia, Kirti; Passricha, Nishat; Khurana, S. M. P.; Tuteja, Narendra
2016-01-01
The Clustered Regularly Interspaced Short Palindromic Repeats associated Cas9/sgRNA system is a novel targeted genome-editing technique derived from bacterial immune system. It is an inexpensive, easy, most user friendly and rapidly adopted genome editing tool transforming to revolutionary paradigm. This technique enables precise genomic modifications in many different organisms and tissues. Cas9 protein is an RNA guided endonuclease utilized for creating targeted double-stranded breaks with only a short RNA sequence to confer recognition of the target in animals and plants. Development of genetically edited (GE) crops similar to those developed by conventional or mutation breeding using this potential technique makes it a promising and extremely versatile tool for providing sustainable productive agriculture for better feeding of rapidly growing population in a changing climate. The emerging areas of research for the genome editing in plants include interrogating gene function, rewiring the regulatory signaling networks and sgRNA library for high-throughput loss-of-function screening. In this review, we have described the broad applicability of the Cas9 nuclease mediated targeted plant genome editing for development of designer crops. The regulatory uncertainty and social acceptance of plant breeding by Cas9 genome editing have also been described. With this powerful and innovative technique the designer GE non-GM plants could further advance climate resilient and sustainable agriculture in the future and maximizing yield by combating abiotic and biotic stresses. PMID:27148329
Farrugia, Kevin J; Deacon, Paul; Fraser, Joanna
2014-03-01
There are a number of studies discussing recent developments of a one-step fluorescent cyanoacrylate process. This study is a pseudo operational trial to compare an example of a one-step fluorescent cyanoacrylate product, Lumicyano™, with the two recommended techniques for plastic carrier bags; cyanoacrylate fuming followed by basic yellow 40 (BY40) dyeing and powder suspensions. 100 plastic carrier bags were collected from the place of work and the items were treated as found without any additional fingermark deposition. The bags were split into three and after treatment with the three techniques a comparable number of fingermarks were detected by each technique (average of 300 fingermarks). The items treated with Lumicyano™ were sequentially processed with BY40 and an additional 43 new fingermarks were detected. Lumicyano™ appears to be a suitable technique for the development of fingermarks on plastic carrier bags and it can help save lab space and time as it does not require dyeing or drying procedures. Furthermore, contrary to other one-step cyanoacrylate products, existing cyanoacrylate cabinets do not require any modification for the treatment of articles with Lumicyano™. To date, there is little peer reviewed articles in the literature on trials related to Lumicyano™ and this study aims to contribute to fill this gap. © 2013.
On the diagnostic emulation technique and its use in the AIRLAB
NASA Technical Reports Server (NTRS)
Migneault, Gerard E.
1988-01-01
An aid is presented for understanding and judging the relevance of the diagnostic emulation technique to studies of highly reliable, digital computing systems for aircraft. A short review is presented of the need for and the use of the technique as well as an explanation of its principles of operation and implementation. Details that would be needed for operational control or modification of existing versions of the technique are not described.