Plastic fingerprint replica: solvent-assisted 3D molding and motion-promoted nano-spherulite formation

Fingerprinting is an essential form of identification for both biometric security and forensics today. Herein, we describe the procedure and principle of creating highly resolved, chemically robust, 3D fingerprint physical replicas, which is based on the solvent-assisted molding of transparent plastics and motion-promoted growth of semi-crystalline polymeric nanostructures. Prior to fingerprinting atop, polycarbonate, a commercial polymer with excellent durability and optical transparency, is first swelled and softened with a mild solvent (acetone). The molding motion conforms polymer chains between fingerprint ridges, which facilitates the formation of semi-crystalline spherulites and results in greater opacity between ridges than underneath ridges. Besides being more enduring than digital scanning and ink printed counterparts, the plastic fingerprint replicas can provide additional morphological information (depth of the ridge) and high-level details (distribution of sweat pores).

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Biometric template security: an overview

Sensor Review ◽

10.1108/sr-07-2017-0131 ◽

2018 ◽

Vol 38 (1) ◽

pp. 120-127 ◽

Cited By ~ 2

Author(s):

Naveed Riaz ◽

Ayesha Riaz ◽

Sajid Ali Khan

Keyword(s):

Provable Security ◽

Feature Transformation ◽

Transformation Techniques ◽

Content Type ◽

General Acceptance ◽

Biometric Security ◽

Template Security ◽

Biometric Template ◽

High Level ◽

Biometric Templates

Purpose The security of the stored biometric template is itself a challenge. Feature transformation techniques and biometric cryptosystems are used to address the concerns and improve the general acceptance of biometrics. The purpose of this paper is to provide an overview of different techniques and processes for securing the biometric templates. Furthermore, the paper explores current research trends in this area. Design/methodology/approach In this paper, the authors provide an overview and survey of different features transformation techniques and biometric cryptosystems. Findings Feature transformation techniques and biometric cryptosystems provide reliable biometric security at a high level. There are many techniques that provide provable security with practical viable recognition rates. However, there remain several issues and challenges that are being faced during the deployment of these technologies. Originality/value This paper provides an overview of currently used techniques for securing biometric templates and also outlines the related issues and challenges.

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Statistical mechanics of chromosomes: in vivo and in silico approaches reveal high-level organization and structure arise exclusively through mechanical feedback between loop extruders and chromatin substrate properties

Nucleic Acids Research ◽

10.1093/nar/gkaa871 ◽

2020 ◽

Vol 48 (20) ◽

pp. 11284-11303

Author(s):

Yunyan He ◽

Josh Lawrimore ◽

Diana Cook ◽

Elizabeth Erin Van Gorder ◽

Solenn Claire De Larimat ◽

...

Keyword(s):

Higher Order ◽

Polymer Chains ◽

Yeast Cells ◽

Model Matching ◽

Circular Chromosome ◽

Chain Polymer ◽

Chromosome Dynamics ◽

High Level ◽

Physical Principles

Abstract The revolution in understanding higher order chromosome dynamics and organization derives from treating the chromosome as a chain polymer and adapting appropriate polymer-based physical principles. Using basic principles, such as entropic fluctuations and timescales of relaxation of Rouse polymer chains, one can recapitulate the dominant features of chromatin motion observed in vivo. An emerging challenge is to relate the mechanical properties of chromatin to more nuanced organizational principles such as ubiquitous DNA loops. Toward this goal, we introduce a real-time numerical simulation model of a long chain polymer in the presence of histones and condensin, encoding physical principles of chromosome dynamics with coupled histone and condensin sources of transient loop generation. An exact experimental correlate of the model was obtained through analysis of a model-matching fluorescently labeled circular chromosome in live yeast cells. We show that experimentally observed chromosome compaction and variance in compaction are reproduced only with tandem interactions between histone and condensin, not from either individually. The hierarchical loop structures that emerge upon incorporation of histone and condensin activities significantly impact the dynamic and structural properties of chromatin. Moreover, simulations reveal that tandem condensin–histone activity is responsible for higher order chromosomal structures, including recently observed Z-loops.

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Particle packing into loose networks for tough and sticky composite gels

Scientific Reports ◽

10.1038/s41598-020-74355-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Taka-Aki Asoh ◽

Tatsuya Yamamoto ◽

Hiroshi Uyama

Keyword(s):

Polymer Network ◽

Particle Packing ◽

Polymer Chains ◽

Stimuli Responsive ◽

Polymer Particles ◽

Composite Gels ◽

Composite Gel ◽

High Level ◽

External Stimuli ◽

Stimuli Responsive Polymer

Abstract Hydrogel is an attractive material, but its application is limited due to its low mechanical strength. In this study, a tough composite gel could be prepared by synthesizing polymer particles within a polymer network having relatively loose cross-linking. Since the polymer network acts as a dispersion stabilizer during the synthesis of the hydrophobic polymer particles, a large amount of particles could be introduced into the gel without agglomeration. It was suggested that the high level of toughness was induced by the adsorption and desorption of the polymer chains on the surface of the finely packed particles. By using a stimuli-responsive polymer network, elasticity and plasticity of composite gels could be controlled in response to external stimuli, and adhesion on the gel surface could also be modulated.

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Irradiation of Pseudoboehmite-Polypropilene Nanocomposites

Journal of Nano Research ◽

10.4028/www.scientific.net/jnanor.29.41 ◽

2014 ◽

Vol 29 ◽

pp. 41-47

Author(s):

Leila F. de Miranda ◽

Antonio H. Minhoz ◽

Rodrigo A. Vicente ◽

Mauro C. Terence ◽

Leonardo G. de Andrade e Silva

Keyword(s):

Low Cost ◽

High Surface ◽

Sol Gel ◽

High Surface Area ◽

Mechanical Tests ◽

Polymeric Matrix ◽

Polymer Chains ◽

Lower Amount ◽

Polymeric Nanocomposites ◽

High Level

Polymeric nanocomposites are hybrid materials, where inorganic nanoscale dimensions substances are dispersed in a polymeric matrix. The fillers have a high surface area, promoting better dispersion in the polymeric matrix and therefore an improvement in physical properties of the composite depending on the homogeneity of the material. The preparation of nanocomposites polymer matrix allows in many cases to find a relationship between low cost due to the use of a lower amount of charge, and a high level of performance. In the present work, nanocomposites of polypropylene with different concentrations of pseudoboehmite obtained by a sol-gel process, and treated with octadecylamine were prepared. After preparation, the samples were irradiated with a 0, 50, 100, 200 e 300kGy radiation dose in an electron accelerator. The pseudoboehmite nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, differential thermal analysis and thermogravimetric analysis. The nanocomposites were characterized by thermal and mechanical tests. The addition of pseudoboehmite promoted a reduction of the melting flow during the production of the composites evidencing the interaction of pseudoboehmite with the polymeric matrix. Because the polypropylene is a semicrystalline polymer, when exposed to the irradiation process, their morphology was modified due to scission mechanisms of the polymer chains.

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Development of a digital SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008609x ◽

1991 ◽

Vol 49 ◽

pp. 358-359

Author(s):

A. Yamada ◽

A. Shibano ◽

K. Harasawa ◽

T. Kobayashi ◽

H. Fukuda ◽

...

Keyword(s):

Large Diameter ◽

Objective Lens ◽

Large Specimen ◽

Backscattered Electrons ◽

Digital Scanning ◽

Junction Type ◽

High Resolution Images ◽

Working Distance ◽

Type Detector ◽

Short Working

A newly developed digital scanning electron microscope, the JSM-6300, has the following features: Equipped with a narrower conical objective lens (OL), it allows high resolution images to be obtained easily at a short working distance (WD) and a large specimen tilt angle. In addition, it is provided with automatic functions and digital image processing functions for ease of operation.Conical C-F lens: The newly developed conical C-F objective lens, having low aberration characteristics over a wide WD range, allows a large-diameter (3-inch) specimen to be tilted up to 60° at short WD, and provides images with low magnifications starting at 10*. On the bottom of the lens, a p n junction type detector is provided to detect backscattered electrons (BE) from the specimen. As the narrower conical 0L increases the secondary electron (SE) detector's field intensity on the specimen surface, high SE image quality is obtained.

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Transcription factor/DNA interactions visualized by electron spectroscopic imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100122654 ◽

1992 ◽

Vol 50 (1) ◽

pp. 450-451

Author(s):

David P. Bazett-Jones ◽

Mark L. Brown

Keyword(s):

Transcription Factor ◽

Dna Sequences ◽

Transcription Initiation ◽

Molecular Mechanisms ◽

Phosphorus Content ◽

Spectroscopic Imaging ◽

Electron Spectroscopic Imaging ◽

Dna Backbone ◽

Two Parameters ◽

High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

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Advances in Stem Instrumentation for Biology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100180562 ◽

1990 ◽

Vol 48 (1) ◽

pp. 362-363

Author(s):

J. S. Wall

Keyword(s):

Scanning Transmission Electron Microscope ◽

Carbon Films ◽

Specimen Preparation ◽

Material Deposition ◽

Active User ◽

Percent Improvement ◽

Scanning Transmission ◽

The Moment ◽

Film Substrate ◽

High Level

The forte of the Scanning transmission Electron Microscope (STEM) is high resolution imaging with high contrast on thin specimens, as demonstrated by visualization of single heavy atoms. of equal importance for biology is the efficient utilization of all available signals, permitting low dose imaging of unstained single molecules such as DNA.Our work at Brookhaven has concentrated on: 1) design and construction of instruments optimized for a narrow range of biological applications and 2) use of such instruments in a very active user/collaborator program. Therefore our program is highly interactive with a strong emphasis on producing results which are interpretable with a high level of confidence.The major challenge we face at the moment is specimen preparation. The resolution of the STEM is better than 2.5 A, but measurements of resolution vs. dose level off at a resolution of 20 A at a dose of 10 el/A2 on a well-behaved biological specimen such as TMV (tobacco mosaic virus). To track down this problem we are examining all aspects of specimen preparation: purification of biological material, deposition on the thin film substrate, washing, fast freezing and freeze drying. As we attempt to improve our equipment/technique, we use image analysis of TMV internal controls included in all STEM samples as a monitor sensitive enough to detect even a few percent improvement. For delicate specimens, carbon films can be very harsh-leading to disruption of the sample. Therefore we are developing conducting polymer films as alternative substrates, as described elsewhere in these Proceedings. For specimen preparation studies, we have identified (from our user/collaborator program ) a variety of “canary” specimens, each uniquely sensitive to one particular aspect of sample preparation, so we can attempt to separate the variables involved.

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A Questionnaire Survey of Current Rehabilitation Practices for Adults With Normal Hearing Sensitivity Who Experience Auditory Difficulties

American Journal of Audiology ◽

10.1044/2020_aja-20-00027 ◽

2020 ◽

Vol 29 (4) ◽

pp. 738-761

Author(s):

Tess K. Koerner ◽

Melissa A. Papesh ◽

Frederick J. Gallun

Keyword(s):

Hearing Aids ◽

Questionnaire Survey ◽

Patient Population ◽

Clinical Care ◽

Normal Hearing ◽

Auditory Training ◽

Training Methods ◽

Hearing Sensitivity ◽

Considerable Benefit ◽

High Level

Purpose A questionnaire survey was conducted to collect information from clinical audiologists about rehabilitation options for adult patients who report significant auditory difficulties despite having normal or near-normal hearing sensitivity. This work aimed to provide more information about what audiologists are currently doing in the clinic to manage auditory difficulties in this patient population and their views on the efficacy of recommended rehabilitation methods. Method A questionnaire survey containing multiple-choice and open-ended questions was developed and disseminated online. Invitations to participate were delivered via e-mail listservs and through business cards provided at annual audiology conferences. All responses were anonymous at the time of data collection. Results Responses were collected from 209 participants. The majority of participants reported seeing at least one normal-hearing patient per month who reported significant communication difficulties. However, few respondents indicated that their location had specific protocols for the treatment of these patients. Counseling was reported as the most frequent rehabilitation method, but results revealed that audiologists across various work settings are also successfully starting to fit patients with mild-gain hearing aids. Responses indicated that patient compliance with computer-based auditory training methods was regarded as low, with patients generally preferring device-based rehabilitation options. Conclusions Results from this questionnaire survey strongly suggest that audiologists frequently see normal-hearing patients who report auditory difficulties, but that few clinicians are equipped with established protocols for diagnosis and management. While many feel that mild-gain hearing aids provide considerable benefit for these patients, very little research has been conducted to date to support the use of hearing aids or other rehabilitation options for this unique patient population. This study reveals the critical need for additional research to establish evidence-based practice guidelines that will empower clinicians to provide a high level of clinical care and effective rehabilitation strategies to these patients.

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